KR19990028254A - Manufacturing Method of Toner for Electrostatic Image Development - Google Patents

Abstract

A method for producing an electrostatic charge image developing toner comprising colored polymer particles by suspension polymerization of a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant,

(1) In the aqueous dispersion medium, the monomer composition for core components containing at least one kind of monomer for core component and colorant which forms a polymer having a glass transition temperature of 80 ° C. or lower until the polymerization conversion ratio of this monomer becomes 80% or more. A first step of suspending polymerization to form colored polymer particles as core components; and

(2) at least one shell component monomer or shell component containing the monomer, which forms a polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component in the reaction system containing colored polymer particles as the core component By adding a monomer composition and a water-soluble radical initiator, and performing a polymerization reaction, core components 40-99 are carried out by two or more processes of the 2nd process of forming the coating layer of the polymer which becomes a shell component on the surface of the colored polymer particle which becomes a core component. A toner for electrostatic image development having low fixing temperature and good OHP permeability and excellent preservation, characterized by producing a core-shell structured colored polymer particle composed of 1% by weight to 60% by weight of shell component. Manufacturing method.

Description

Manufacturing Method of Toner for Electrostatic Image Development

Conventionally, an electric latent image formed by an electrophotographic apparatus or an electrostatic lock apparatus is first developed into a toner, and then the toner image formed is transferred onto a transfer material such as paper, if necessary, and then fixed by various methods such as heating, pressurization, and solvent vapor. do.

Conventionally, toners have generally been produced by melt-mixing colorants, charge control agents, anti-offsetants and the like in a thermoplastic resin to uniformly disperse the composition, and then pulverizing and classifying the composition. According to this manufacturing method (i.e., pulverization method), a toner having some excellent characteristics can be produced, but there is a limit to the selection of a toner material. For example, the composition resulting from the melt mixing should be one that can be milled and classified into a device that can be used economically. In such a request, the melt mixed composition must be sufficiently soft. Therefore, when the composition is pulverized to form particles, a wide range of particle size distributions are easily formed, and thus, for obtaining a radiation image with good resolution and gradation, for example, fine powder having a particle size of 5 μm or less and coarse powder of 20 μm or more can be obtained. The disadvantage is that the yield is very low since it must be removed by classification.

In addition, in this pulverization method, it is difficult to uniformly disperse solid fine particles such as colorants, charge control agents, and anti-offsetting agents in the thermoplastic resin, and depending on the dispersion state of these solid fine particles, it is possible to increase the fog and lower the image concentration. Becomes Non-uniform dispersion of these solid fine particles in the pulverization method greatly affects the fluidity, frictional chargeability, and the like of the toner, and influences the characteristics such as the developability and durability of the toner. Therefore, in the grinding method, sufficient care must be taken to uniformly disperse these solid fine particles.

In recent years, in order to overcome the problems in these grinding methods, a production method of a toner by suspension polymerization has been proposed. In this suspension polymerization method, a monomer composition obtained by uniformly dissolving or dispersing a polymerizable monomer, a colorant, a charge control agent, an anti-offset agent, a polymerization initiator, and the like is introduced into water containing a dispersion stabilizer or an aqueous dispersion medium mainly composed of water. After dispersing using a mixing device having a high shear force, the monomer composition is granulated into minute drops, and then polymerized to form toner particles (ie, polymerized toner).

In the suspension polymerization method, a colorant, a charge control agent, an anti-offsetter and the like are added and dispersed in a monomer having a low viscosity liquid phase, so that sufficient dispersibility is ensured as compared with a pulverization method dispersed in a resin. In addition, in the suspension polymerization method, toner particles having a desired particle diameter can generally be obtained in a yield of 90% or more, which is economically advantageous compared to the grinding method. By adopting the suspension polymerization method as described above, the problem of the pulverization method can be solved, and the toner excellent in image quality characteristics such as resolution and blur can be economically produced based on the extremely sharp particle size distribution and good electrical properties of the polymer particles. It became.

In recent years, the power consumption has been reduced in electrophotographic copying machines, printers, and the like, which use toner. In the electrophotographic process, in particular, a process that consumes energy is a so-called fixing process when the toner is transferred from a photosensitive member onto a transfer material such as paper and then fixed. In general, a heated roll of 150 ° C. or more is used for fixing, and power is used as the energy source. Lowering the temperature of this heat roll is required from the viewpoint of energy saving. To this end, it is necessary to lower the fixing temperature of the toner.

In the design of the toner, the glass transition temperature of the toner may be lowered in order to meet the demands from the copying machine, and the like. When the glass transition temperature is lowered, blocking occurs in the storage of the toner or in the toner box, and becomes agglomerates. This becomes a bad toner.

On the other hand, in the case of color toners by the electrophotographic method, color images are often used for OHP sheets for presentation in various meetings in recent years, and it is required to have excellent OHP permeability for color toners. In order to satisfy the OHP permeability, it is essential to melt the toner uniformly on the OHP sheet. For this purpose, it is necessary to design the melt viscosity near the fixing temperature of the toner to be lower than that of the conventional one. As a method of lowering the melt viscosity of the toner, there are methods such as lowering the molecular weight and lowering the glass transition temperature as compared with conventional binder resins for toner.But it is easy to cause blocking by adopting any of the methods. do.

As described above, the method of lowering the fixing temperature of the toner or improving the OHP permeability and the retention of the toner are inversely related. As a method of solving the reverse correlation, the toner particles are conventionally coated with a polymer having a high glass transition temperature. A so-called capsule-type toner which solves the storage property by using the same has been proposed.

Conventionally, as a manufacturing method of a capsule-type toner, for example, Japanese Patent Laid-Open No. 60-173552 uses a jet mill device to form a coating layer made of colorant, magnetic particles or conductive agent and a binder resin on the surface of nuclear body particles. Is proposed. However, this method is not applicable because the nucleus particles themselves cause aggregation when the glass transition temperature of the nucleus particles is low.

JP-A-2-259657 discloses crosslinked toner particles prepared by suspension polymerization in a solution in which an encapsulating polymer, a charge control agent and a release agent are dissolved in an organic solvent, and then a poor solvent is added to the crosslinked toner particles. A method for producing an electrophotographic toner has been proposed which forms a coating of an encapsulating polymer containing a charge control agent and a release agent on its surface. However, this manufacturing method has a problem that the thickness of the formed capsule wall is not constant because the solubility of the encapsulating polymer is reduced by dropping the poor solvent to precipitate onto the surface of the crosslinked toner particles.

Japanese Laid-Open Patent Publication No. 57-45558 discloses a coating layer of microparticles obtained by emulsion polymerization on the surface of nucleus particles by adding and dispersing the nucleus particles formed by polymerization in 1 to 40% by weight of a latex aqueous solution and then adding an aqueous solution inorganic salt. A manufacturing method of a toner for developing an electrostatic charge image is proposed. However, this method has a drawback in that charging is largely dependent on the environment due to the influence of surfactants and inorganic salts remaining on the microparticles, and particularly, under high temperature and high humidity conditions.

Disclosure of the Invention

An object of the present invention is to provide a method for producing a toner for developing electrostatic images, which has a low fixing temperature, good OHP permeability and excellent storage properties.

The present inventors earnestly studied to overcome the problems of the prior art, and as a result, in the method for producing toner particles by suspension polymerization, first, polymer particles having a glass transition temperature of 80 ° C. or lower are used as core components (nuclear particles). And then adding a monomer forming a polymer having a higher glass transition temperature than the polymer of the core component to continue the polymerization reaction, thereby forming a capsular toner by forming a coating layer of a shell component having a high glass transition temperature on the surface of the core component. As a result, it was found that this capsule-type toner had a low fixing temperature and good OHP permeability, and prevented blocking due to the presence of a shell component, and was excellent in shelf life. The core component contains a colorant to obtain colored polymer particles.

In addition, when preparing a capsule toner by the suspension polymerization method, the monomer for shell component or the monomer composition for shell component containing the monomer and the water-soluble radical initiator are added to the suspension polymerization reaction system in the presence of colored polymer particles of the core component. By carrying out the polymerization reaction, it has been found that a method of forming a coating layer of a polymer serving as a shell component on the surface of polymer particles of a core component is preferable.

And (1) adding the monomer for shell component or the monomer composition for shell component containing the monomer to the reaction system as an aqueous suspension of droplets having a smaller number average particle diameter than the colored polymer particles of the core component, or carrying out a polymerization reaction, or (2) When a monomer having a solubility of less than 0.1% by weight in water at 20 ° C. is used as the monomer for the shell component, the reaction system is used in water at 20 ° C. together with the monomer for the shell component or the monomer composition for shell components containing the monomer. It has been found that when the polymerization is performed by adding an organic solvent having a solubility of 5% by weight or more, it is possible to form a coating layer of a polymer that becomes a shell component efficiently.

The present invention has been completed based on these aspects.

In the present invention, the capsular toner or the capsular colored polymer particles is a core in which a coating layer (i.e. shell component) of a polymer to be a husk is formed on the surface of colored polymer particles (i.e., core component) to be a nucleus. It means colored polymer particles having a core-shell construction.

Thus, according to this invention, in the method of manufacturing toner for electrostatic image development which becomes colored polymer particle by suspension-polymerizing the monomer composition containing at least a polymerizable monomer and a coloring agent in the aqueous dispersion medium containing a dispersing agent, (1 ) Suspended in the aqueous dispersion medium a monomer composition for core components containing at least one monomer for core component and a colorant which forms a polymer having a glass transition temperature of 80 ° C. or lower until the polymerization conversion ratio of this monomer is 80% or more. Forming a polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component in the reaction system containing the first step of polymerizing to form the colored polymer particles of the core component and (2) the colored polymer particles of the core component. Monomer composition for shell components containing at least one monomer or shell component 40 to 99% by weight of the core component by at least two steps of the second step of forming a coating layer of the polymer as the shell component on the surface of the colored polymer particles as the core component by carrying out the polymerization reaction with the addition of a water-soluble radical initiator. And a core-shell structured colored polymer particle composed of 1 to 60% by weight of shell components.

Moreover, according to this invention, at least 1 sort (s) of monomer for shell components which forms the polymer of glass transition temperature higher than the glass transition temperature of the polymer of a core component in the reaction system containing colored polymer particle which becomes a core component as said 2nd process. Or the monomer composition for shell components containing this monomer is added as a water suspension of the droplet whose number average particle diameter is smaller than the colored polymer particle which becomes a core component, and a polymerization reaction is carried out to the surface of the colored polymer particle which becomes a core component. A method for producing an electrostatic image developing toner is provided, which forms a coating layer of a polymer that is a shell component.

And according to this invention, at least 1 sort (s) of monomer for shell components which forms the polymer of the glass transition temperature higher than the glass transition temperature of the polymer of a core component in the reaction system containing colored polymer particle which becomes a core component as said 2nd process. Or by carrying out the polymerization reaction by adding an organic solvent having a solubility of 5% by weight or more in water at 20 ° C together with the monomer composition for shell components containing the monomer, thereby forming a shell component on the surface of the colored polymer particles as the core component. A method for producing an electrostatic charge image developing toner is provided which forms a coating layer of a polymer.

According to the present invention, there is provided a toner for developing electrostatic images obtained by the above-described manufacturing method.

According to the present invention, there is provided an image forming apparatus having accommodation means for accommodating toner for developing electrostatic images obtained by the above-described manufacturing method.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a toner for developing an electrostatic charge image, and more particularly, to a method of manufacturing a toner for developing an electrostatic charge image formed by an electrophotographic method, an electrostatic lock method, or the like.

1 is a cross-sectional view of an image forming apparatus having a receiving means for receiving a toner for developing electrostatic images of the present invention.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Manufacturing method of toner

The toner for developing electrostatic images of the present invention is produced by adopting a suspension polymerization method. In the suspension polymerization method, colored polymer particles are prepared by adding and suspending polymerization of a monomer liquid containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant. More specifically, a colorant, a radical polymerization initiator, a charge control agent and other additives are added to the vinyl monomer to prepare a mixed liquid (ie, monomer composition) uniformly dispersed in a ball mill or the like, and then the mixed liquid is added to the aqueous dispersion. After dispersing using a mixing device having a high shearing force and assembling into fine droplets, the suspension is polymerized at a temperature of usually 30 to 200 ° C.

In the present invention, a multistage polymerization method is adopted to produce a capsular toner by suspension polymerization. That is, a method of producing a toner for electrostatic image development comprising colored polymer particles by suspending and polymerizing a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant, at least in the following two steps. Suspension polymerization is carried out.

(1) When the monomer conversion composition of the core component containing at least 1 type of monomer for core components and a coloring agent which forms a polymer with a glass transition temperature of 80 degrees C or less in an aqueous dispersion medium becomes 80% or more. A polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component is added to the reaction system containing the first step of suspending polymerization to form colored polymer particles of the core component and (2) the colored polymer particles of the core component. The polymer which becomes a shell component on the surface of the colored polymer particle which becomes a core component by carrying out a polymerization reaction by adding at least 1 sort (s) of shell component monomers to form, or the monomer composition for shell components containing this monomer, and a water-soluble radical initiator is carried out. 2nd process of forming a coating layer.

By these at least two processes, the core-shell structured colored polymer particle which consists of 40-99 weight% of core components and 1-60 weight% of shell components is manufactured. As long as the capsule-shaped colored polymer particles having this core-shell structure are formed, additional steps may be present.

At least 1 sort (s) of shell component monomers or this monomer which form the polymer of the glass transition temperature higher than the glass transition temperature of the polymer of a core component in the reaction system containing the colored polymer particle which becomes a core component as said 2nd process is contained. By adding a monomer composition for shell components as an aqueous suspension of droplets having a smaller number average particle diameter than colored polymer particles serving as a core component and carrying out a polymerization reaction, the polymers serving as shell components form the surface of colored polymer particles serving as a core component. The process of forming a coating layer can be employ | adopted.

Or at least 1 type of shell component monomer or this monomer which forms the polymer of the glass transition temperature higher than the glass transition temperature of the polymer of a core component in the reaction system containing the colored polymer particle which becomes a core component as said 2nd process is contained. The polymerized reaction layer is formed on the surface of the colored polymer particles as the core component by carrying out a polymerization reaction by adding an organic solvent having a solubility in water at 20 ° C. of 5% by weight together with the monomer composition for shell components. The process can be adopted.

Here, the glass transition temperature (Tg) of a polymer is a calculated value (called calculation Tg) calculated according to the kind of monomer to be used, and a use ratio. When there is one type of monomer to be used, Tg of the homopolymer formed from this monomer is defined as Tg of a polymer in this invention. For example, since Tg of polystyrene is 100 degreeC, when using styrene alone as a monomer, this monomer forms a polymer whose Tg is 100 degreeC. When there are two or more types of monomers to be used, and the polymer produced is a copolymer, Tg of a copolymer is computed according to the kind of monomer to be used and a use ratio. For example, when 60 weight% of styrene and 40 weight% of n-butylacrylate are used as a monomer, since the Tg of the styrene-n-butylacrylate copolymer produced by this monomer ratio is 20 degreeC, this monomer mixture Is said to form a polymer having a Tg of 20 ° C.

In addition, the provision of "at least 1 type of core component monomers which form the polymer of glass transition temperature of 80 degrees C or less" means that each of all the monomers for core components must form a polymer of Tg 80 degrees C or less. It is not. When using one type of monomer as a core component monomer, Tg of the homopolymer formed from this monomer should be 80 degrees C or less. However, when using 2 or more types of monomer mixtures as a monomer for core components, Tg of the copolymer formed from this monomer mixture should just be 80 degrees C or less, and the Tg of the polymer of its own in this monomer mixture exceeds 80 degreeC. It may contain. For example, the homopolymer of styrene has a Tg of 100 ° C., but a copolymer having a Tg of 80 ° C. or less is used by mixing with a monomer (for example, n-butylacrylate) forming a low Tg polymer. When it can form, styrene can be used as a kind of monomer for core components. On the contrary, even if it is a monomer which forms the polymer of low Tg, when the copolymer of high Tg can be formed by combining with the monomer which forms high Tg, it can be used as a kind of monomer for shell components.

The height of Tg between the polymer of the core component and the polymer of the shell component is relative. For example, when the monomer for the core component forms a polymer of Tg = 80 ° C., the monomer for the shell component should be one for forming a polymer of Tg exceeding 80 ° C. However, when the monomer for core components forms a polymer of Tg = 20 degreeC, the monomer for shell components may form a polymer of Tg = 60 degreeC, for example. In addition, Tg is a value measured by measuring instruments, such as a normal DSC.

In the shear polymerization step (first step) for forming the core component, at least one monomer for forming a polymer having a Tg of 80 ° C. or less is used as the monomer. In order to adjust Tg, you may use independently the monomer which gives a low Tg polymer, but normally, it uses combining the monomer which gives a high Tg polymer and the monomer which gives a low Tg polymer. By using a some monomer in combination, it can adjust easily to desired Tg. Tg of the polymer which forms a core component is 0-80 degreeC normally, Preferably it is 10-60 degreeC, More preferably, it is 15-50 degreeC.

As a monomer which forms a core component in this invention, it is necessary to select so that Tg of the polymer formed from this monomer may be 80 degrees C or less. The fixing of the toner image onto a transfer material such as paper is generally performed by a heat roll. In this heat fixing process, the polymer of the core component is melted as a binder resin at a relatively low fixing temperature, and Tg is used to project the transfer material onto the transfer material. It is necessary to set it to 80 degrees C or less. In addition, in order for the fixed image to satisfy OHP permeability, the toner must be melted uniformly on the OHP sheet. For this purpose, it is preferable to adjust the Tg of the polymer of the core component to 80 ° C or lower.

Although the coloring agent is contained in the monomer for core components, it is preferable to also contain a radical polymerization initiator, various additives, etc. normally. Each of these components is stirred and mixed with a mixer having high shearing force to prepare a monomer composition for core components (monomer solution for core components) uniformly dispersed. The monomer composition for a core component is thrown in the aqueous dispersion medium containing a dispersing agent, and it disperse | distributes using a mixing device which has a high shear force, and granulates into fine droplets. Subsequently, suspension polymerization is normally performed at a temperature of 30-200 degreeC, and polymerization conversion ratio is made into 80% or more. In this way, polymer particles serving as core components are formed. If the polymerization conversion rate of the monomer forming the core component is less than 80%, since the monomer for the core component remains in a relatively large amount in the reaction system, the polymerization is continued by adding the monomer for the shell component or the monomer composition for the shell component containing the monomer. In addition, since it is difficult to copolymerize both monomers and form a high Tg shell component (coating layer), the effect by encapsulation becomes insufficient. The polymerization conversion ratio in the shear polymerization step is preferably 85% or more, and more preferably 90% or more.

In the shear polymerization step, various dispersion stabilizers used in ordinary suspension polymerization can be used as the dispersant. Moreover, as a polymerization initiator, the oil-soluble radical polymerization initiator used by normal suspension polymerization, such as 2, 2- azoisobutylonitrile, can be used preferably.

In the shear polymerization step (second step) for forming the shell component, the polymerization conversion ratio of the monomer for the core component is 80% or more, and then the monomer for the shell component or the monomer composition for the shell component containing the monomer (hereinafter, for the shell component) Monomer liquid) may be added to the reaction system to continue the polymerization reaction. As a monomer for shell components, the monomer which forms the polymer which is higher Tg than the polymer of a core component is used. The monomer for shell components can be used as a monomer composition by containing various additives, such as a charge control agent, as needed.

As a monomer which forms a polymer of high Tg, it is preferable to use the monomer which forms a polymer with Tg more than 80 degreeC, such as styrene and methylmethacrylate, individually or in combination of 2 or more types, respectively. However, when Tg of the polymer of a core component is much lower than 80 degreeC, the monomer for shell components may form a polymer of 80 degrees C or less. However, as the monomer forming the shell component, the main purpose of the encapsulation by the shell component polymer is to maintain the toner retention, and therefore it is necessary to set the Tg of the polymer of the shell component to be at least higher than the Tg of the polymer of the core component. The Tg of the polymer forming the shell component is usually more than 50 ° C and 120 ° C or less, preferably more than 60 ° C and 110 ° C or less, and more preferably more than 80 ° C and 105 ° C or less. If the Tg of the shell component polymer is too low, even if the Tg is higher than the Tg of the core component polymer, the storage stability of the toner is deteriorated, which is not preferable. Tg difference between a core component polymer and a shell component polymer is 20 degreeC or more normally, Preferably it is 40 degreeC or more, More preferably, it is 50 degreeC or more.

When the monomer for shell component or the monomer composition for shell component containing the monomer is added to the reaction system, the particle diameter of the droplet is preferably smaller than the particle diameter of the polymer particles forming the core component with a number average particle diameter. If the number average particle diameter of the droplets of the shell component monomer or monomer composition is larger than the particle diameter of the polymer particles of the core component, the transition of the shell component monomers to the polymer particles of the core component consists only of the collision with the polymer particles of the core component. Not efficient. If the number average particle diameter of the droplets of the shell component monomer or monomer composition is smaller than the particle diameter of the polymer particles of the core component, the transfer of the shell component monomer via the continuous medium in a thermodynamic manner in addition to the impact on the polymer particles. It is efficient because it happens too. In order to add the monomer or monomer composition for shell components to the polymerization system as small droplets, the aqueous suspension of the droplets of the monomer or monomer composition can be obtained by undispersing the mixture of the monomer or monomer composition and the aqueous dispersion medium, for example, using an ultrasonic emulsifier. It is preferable to add it as it is.

By the way, when the solubility in the dispersion medium of the shell component monomer is less than 0.1% by weight, when the shell component monomer or monomer composition is added in the reaction system, the droplet diameter becomes tens of micrometers or more, so that the particle diameter of the polymer particles of the core component It is usually larger. In this case, as described above, the transition of the monomer for the shell component to the polymer particles of the core component is not efficient because only the collision of the core component with the polymer particles is caused, and the monomer for the shell component is uniformly introduced into the core component polymer particles. It becomes difficult to do Therefore, when using a monomer having a very low solubility in water such as styrene, it is preferable to add it as an aqueous suspension of the droplets of the monomer or the monomer composition by microdispersion treatment using an ultrasonic emulsifier or the like.

When the solubility of the shell component monomer in the dispersion medium is 0.1% by weight or more, since the equilibrium relationship is generated between the shell component monomer or monomer droplets, the core component polymer particles, and the aqueous dispersion medium, the shell component monomer is thermodynamically stable. It was found to be rapidly transitioned to the core component polymer particle side. In other words, the monomer for the shell component is introduced into the core component weight particles efficiently and uniformly. Therefore, as long as the monomer for the shell component has a solubility (measured at 20 ° C.) of the dispersion medium in water of at least 0.1% by weight, it is not necessarily necessary to perform the microdispersion treatment using an ultrasonic emulsifier or the like, and the monomer is directly added to the reaction system. Can be added. In this case, if the reaction component conversion rate of the core component polymer particle | grains is 80% or more, it may add collectively in a reaction system, or it may add continuously or intermittently using pumps, such as a plunger pump. As the solubility in water at 20 ° C. of 0.1% by weight or more, suitable monomers for forming the shell component polymers include, for example, methyl methacrylate, acrylonitrile, vinyl acetate, acrolein, and each of these alone or It is preferable to use so that Tg of the polymer formed by combining 2 or more types may be more than 50 degreeC, Preferably it is more than 60 degreeC, More preferably, it is more than 80 degreeC.

As a result of further studies, the present inventors have found that, in the second step of the present invention, when an organic solvent having a solubility in water of 20 ° C. of 5 ° C. or more is added to the aqueous dispersion medium, the solubility in water of 20 ° C. is 0.1. Even when a monomer with less than% by weight is used, an equilibrium relationship is formed between the droplets of the monomer for the shell component or the monomer composition, the core component polymer particles, and the dispersion medium, so that the monomer for the shell component is rapidly shifted to the thermodynamically stable core component polymer side. It became. In other words, the monomer for the shell component is efficiently and uniformly introduced into the polymer particles for the core component. The reason for this is that even if the monomer is very poorly soluble in water by adding the organic solvent in the second step, the solubility in the dispersion medium is improved and the solubility becomes 0.1% by weight or more. Therefore, when the organic solvent is added in the second step, when the monomer or monomer composition for the shell component is added to the reaction system, it is not necessary to perform the microdispersion treatment using an ultrasonic emulsifier or the like in advance and can be added to the reaction system as it is. . In this case, the monomer or monomer composition for shell components can be added collectively in a reaction system or added continuously or intermittently using pumps, such as a plunger pump, when the polymerization conversion ratio of the monomer for core components is 80% or more.

A monomer having a solubility in water at 20 ° C. of less than 0.1% by weight and suitable for forming a shell component polymer includes styrene, butyl acrylate, 2-ethylhexyl acrylate, ethylene and propylene. Further, even when a monomer having a solubility in water of 20 ° C. of 0.1% by weight or more is used, the formation of the shell component weight is more efficiently formed by performing microdispersion treatment using an ultrasonic emulsifier or the like or adding an organic solvent to the reaction system. Can be carried out. A monomer having a solubility in water of 20 ° C. of 0.1% by weight or more, and suitable monomers for forming the shell component polymers include methyl methacrylate, acrylonitrile, vinyl acetate, acrolein, and the like. It is preferable to use these monomers individually or in combination of 2 or more types so that the Tg of the polymer formed may be normally more than 50 degreeC, Preferably it is more than 60 degreeC, More preferably, it is more than 80 degreeC.

When the organic solvent is added to the reaction system in the second step, a solubility in water of 20 ° C. of 5 ° C. or more is used as the organic solvent. In an organic solvent having a solubility in water of less than 5% by weight, it is difficult to increase the solubility of the poorly water-soluble monomer in the dispersion medium. As such an organic solvent, For example, lower alcohols, such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, butyl alcohol; Cyclic ethers such as ketones such as acetone and methyl ethyl ketone, tetrahydrofuran and dioxane; Ethers such as dimethyl ether and diethyl ether; Amides, such as dimethylformamide, are mentioned.

The amount of the organic solvent added is a ratio such that the solubility of the monomer for shell component in the dispersion medium (water + organic solvent) is 0.1% by weight or more. The required amount of the organic solvent varies depending on the kind and amount of the monomer for the shell component to be used, the kind of the organic solvent, and the like. On the other hand, if a large amount of organic solvent is added to the aqueous dispersion medium, there is a fear that the suspension polymerization reaction is inhibited. Therefore, the amount of the organic solvent added is preferably 0.1 to 50 parts by weight, preferably 0.1 to 40 parts by weight, more preferably 0.1 to 30 parts by weight based on 100 parts by weight of the aqueous dispersion medium.

The organic solvent may be added before, simultaneously or after the addition of the monomer or monomer composition for the shell component in the second step, but it is better to add the organic solvent in the aqueous dispersion medium prior to the addition of the monomer or monomer composition for the shell component. It is preferable from a viewpoint. In particular, when using a monomer or monomer composition for shell components containing a monomer having a solubility in water at 20 ° C. of less than 0.1% by weight, the organic solvent is added to the reaction system, and then the monomer or monomer composition for shell components is added. It is preferable to continue the polymerization reaction.

However, before adding the organic solvent to the reaction system, the polymerization reaction is continued by adding a monomer or monomer composition for shell components containing a monomer having a solubility in water at 20 ° C. of 0.1% by weight or more, and then adding the organic solvent to the reaction system. Thereafter, the polymerization reaction may be continued by adding a monomer or monomer composition for shell component having a solubility in water at 20 ° C. of less than 0.1% by weight. That is, in this method, the monomer for a 1st shell component or the 1st shell component containing this monomer which has a solubility in water of 20 degreeC is 0.1 weight% or more, before adding an organic solvent to (i) reaction system in a 2nd process. The monomer composition is added to carry out the polymerization reaction, and (ii) the second shell component monomer having a solubility in organic solvent and water at 20 ° C. of less than 0.1 wt% in the reaction system or the monomer for the second shell component containing the monomer. The polymerization is carried out by adding the composition. According to this method, since the shell of the two-layer structure can be formed, the fixing temperature of the toner can be adjusted. Although the ratio of a 1st shell component and a 2nd shell component can be suitably determined, it is 1: 9-9: 1 by weight ratio normally.

In a 2nd process, when adding the monomer for monomers or a monomer composition in a polymerization reaction system, it is preferable to add a water-soluble radical initiator simultaneously with or after addition. By adding a water-soluble radical initiator, radicals generated in the aqueous medium enter the polymer particles by collision, so that while the monomer for shell component is near the surface of the polymer particle (that is, the monomer for shell component is completely absorbed into the polymer particle). Before) polymerization can be initiated to facilitate the capsule wall (shell).

As a water-soluble radical initiator, Persulfates, such as potassium persulfate and an ammonium persulfate; 4,4-Azobis (4-cyanoylacetic acid), 2,2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis-2-methyl-N-1,1-bis (hydr Azo initiators, such as oxymethyl) -2-hydroxyethyl propioamide; Combinations of oil-soluble initiators such as cumene peroxide and redox catalysts; Etc. can be illustrated. The amount used is 0.001 to 1% by weight based on the aqueous catalyst. If it is less than 0.001 weight%, sufficient effect cannot be exhibited, and if it is more than 1 weight%, the particle | grains less than 1 micrometer of particle diameters are byproduced, and it is unpreferable.

In this way, the capsule colored polymer particles (toner particles) composed of 40 to 99% by weight of the core component and 1 to 60% by weight of the shell component are produced.

Monomer

As a monomer which forms a core component in this invention, it is necessary to select so that Tg of the polymer formed from this monomer may be 80 degrees C or less. On the other hand, as a monomer which forms a shell component, it is necessary to set so that Tg of the polymer formed from this monomer may become higher than Tg of the polymer of a core component at least.

In the present invention, a vinyl monomer is usually used as the polymerizable monomer for the core component and the shell component. By using these vinyl monomers individually or in combination of 2 or more types, Tg of the polymer of a core component and a shell component is adjusted to a desired range.

As a vinyl monomer used by this invention, For example, methylene monomers, such as styrene, vinyltoluene, (alpha) -methylstyrene; Acrylic acid and methacrylic acid; Acrylic acid, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, acrylonitrile, and acrylamide Or derivatives of methacrylic acid; Ethylenically unsaturated monoolefins such as ethylene, propylene and butylene; Vinyl halides such as vinyl chloride, vinylidene chloride and vinyl fluoride; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; Nitrogen-containing vinyl compounds such as 2-vinylpyridine, 4-vinylpyridine and N-vinylpyrrolidone; Etc. can be mentioned. These vinyl monomers may be used alone or in combination of a plurality of monomers.

As a monomer whose solubility with respect to water of 20 degreeC is 0.1 weight% or more, For example, (meth) acrylic acid ester, such as methyl (meth) acrylate; Amides such as (meth) acrylamide; Vinyl cyanide compounds such as (meth) acrylonitrile; Vinyl nitrogen compounds such as 4-vinylpyridine, vinyl acetate, acrolein and the like. On the other hand, styrene, butyl acrylate, 2-ethylhexyl acrylate, ethylene, propylene, etc. are mentioned as a monomer whose solubility in water at 20 degreeC is less than 0.1 weight%.

Arbitrary crosslinking agents can be used with these vinylic monomers as needed. As a crosslinking agent, For example, aromatic divinyl compounds, such as divinylbenzene, divinyl naphthalene, and derivatives thereof; Diethylenic unsaturated carboxylic acid esters such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; Divinyl compounds such as N, N-divinyl aniline and divinyl ether; Compounds having three or more vinyl groups; Etc. can be mentioned. These crosslinking agents can be used individually or in combination of 2 types or more, respectively. In this invention, it is preferable to use a crosslinking agent in the ratio of 0.1-5 weight part normally, Preferably it is 0.3-2 weight part with respect to 100 weight part of vinylic monomers.

Dispersant

In this invention, as a dispersing agent (dispersion stabilizer) used at the time of suspension polymerization, what is used by normal suspension polymerization can be used. Dispersants generally form a protective colloidal film, and are generally divided into two types, a water-soluble polymer and a poorly water-soluble inorganic material that express repulsive force due to steric hindrance. As a water-soluble polymer, polyvinyl alcohol, methyl cellulose, gelatin, etc. can be illustrated, for example. As the poorly water-soluble inorganic substance, for example, hardly water-soluble salts such as calcium phosphate, barium sulfate, calcium sulfate, barium carbonate, calcium carbonate and magnesium carbonate; Inorganic polymer materials such as talc and silicic acid; Metal hydroxides such as metal oxides such as aluminum oxide and titanium oxide, aluminum hydroxide and ferric hydroxide; Etc. can be illustrated.

As the dispersant, it is preferable to use a poorly water-soluble metal hydroxide colloid produced by the reaction in the aqueous phase of the water-soluble polyvalent metal salt and the alkali metal hydroxide salt. This poorly water-soluble metal hydroxide colloid has a number particle size distribution of D ₅₀ (50% cumulative value of the number particle size distribution) of 0.5 µm or less and D ₉₀ (90% cumulative value of the number particle size distribution) of 1 µm or less.

A dispersant is normally used in the ratio of 0.1-20 weight part with respect to 100 weight part of vinylic monomers. When this ratio is less than 0.1 part by weight, it is difficult to obtain sufficient polymerization stability, and polymerization aggregates are easily generated. On the contrary, if it exceeds 20 parts by weight, the effect of the polymerization safety is saturated and it is not economical.

Oil Soluble Polymerization Initiator

The oil-soluble polymerization initiator used in the shear polymerization step may be soluble in the monomer to be used. Examples thereof include methyl ethyl peroxide, di-t-butyl peroxide, acetyl peroxide, dicumyl peroxide, and laurate. Loylperoxide, benzoylperoxide, t-butylperoxy-2-ethylhexanoate, di-isopropylperoxydicarbonate, di-t-butylperoxyisophthalate, succinicamide peroxide, t-butylperper Peroxides, such as oxyisobutylate and t-hexyl peroxy-2-ethylhexanoate; Azo compounds such as 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutylnitrile and 1,1'-azobis (1-cyclohexanecarbonitrile); Etc. can be mentioned.

Among these oil-soluble initiators, the temperature at which the half-life is 10 hours (10-hour half-life) is 60 to 80 because of less odor upon factor evaluation of the obtained toner and less environmental damage due to volatilization components such as odor. Organic peroxides having a molecular weight of 250 ° C., preferably 65 to 80 ° C. and 250 or less, in particular t-butylperoxy-2-ethylhexanoate, are preferred. When the 10-hour half life of the oil-soluble polymerization initiator is less than 60 ° C, the polymerization temperature is 80 ° C or less, and the amount of remaining monomers increases. When the half-life of 10 hours exceeds 80 ° C., the polymerization temperature becomes 100 ° C. or more, so that the polymerization vessel needs to be internal pressure. When the molecular weight of the oil-soluble polymerization initiator exceeds 250, the molecular weight of the polymerization initiator decomposition product increases after the completion of the reaction, the amount of volatile components increases without being blown off during drying, and the odor becomes stronger. Azo polymerization initiators generally tend to have a strong odor. Even if the molecular weight of the polymerization initiator is 250 or less, the amount of the residual monomers tends to increase when the aromatic ring is used. The reason for this is presumably because polymerization reaction is inhibited when coloring agents such as carbon black are present.

These oil-soluble polymerization initiators are usually used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

coloring agent

As a coloring agent used by this invention, salt pigments, such as carbon black, nigrosine base, aniline blue, chalcoil blue, chrome yellow, ultramarine blue, orient oil red, phthalocyanine blue, malachite green oxalate, for example Ryu; Magnetic particles such as cobalt, nickel, iron trioxide, iron trioxide, manganese oxide, zinc oxide, and nickel iron oxide; Etc. can be mentioned. The dye pigments are usually used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer. The magnetic particles are usually used in an amount of 1 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the polymerizable monomer.

additive

Various additives, such as an oil-soluble polymerization initiator, a molecular weight modifier, a crosslinking agent, a mold release agent, a charge control agent, can be added to a polymerizable monomer composition (monomer liquid) as needed. A soluble polymerization initiator and a crosslinking agent are as above-mentioned.

As a molecular weight modifier, For example, mercaptans, such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan; Halogenated hydrocarbons such as carbon tetrachloride and carbon tetrabromide; Etc. can be mentioned. These molecular weight modifiers can be added before or during polymerization. The molecular weight modifier is usually used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

As a mold release agent, For example, Low molecular weight polyolefins, such as low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight polybutylene; Paraffin waxes; Etc. can be mentioned. The mold release agent is usually used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer.

It is preferable to contain a charge control agent in the polymerizable monomer composition in order to improve the chargeability of the toner. As the charge control agent, charge control agents of various positive or negative charges can be used. Specific examples of the charge control agent include nigrosin N01 (manufactured by Orient Chemical Co., Ltd.), nigrosine EX (manufactured by Orient Chemical Co., Ltd.), spiron black TRH (manufactured by Hodogaya Chemical Co., Ltd.), and T-77 (manufactured by Hodogaya Chemical Co., Ltd.). ), Bontron S-34 (made by Orient Chemical Co., Ltd.), Bontron E-84 (made by Orient Chemical Co., Ltd.), etc. are mentioned. The charge control agent is usually used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight based on 100 parts by weight of the polymerizable monomer. Use of the charge control agent together with the monomer for the shell component is preferable because the resulting toner has less blur.

And lubricants such as oleic acid and stearic acid for the purpose of uniform dispersion of the colorant into toner particles and the like; Dispersion aids such as silane-based or titanium-based coupling agents; You may contain etc. in a polymerizable monomer composition. Such lubricants and dispersants are usually used in a ratio of about 1 / 1,000 to 1/50 based on the weight of the colorant.

Electrostatic Image Toner

The electrostatic charge image developing toner of the present invention is a capsular toner particle comprising 40 to 99% by weight of the core component, preferably 50 to 95% by weight, and 1 to 60% by weight of the shell component, preferably 5 to 50% by weight. If the proportion of the shell component is too small, the effect of improving the preservation properties by encapsulation is small. On the contrary, if the proportion of the shell component is too large, the effect of reducing the fixing temperature and improving the OHP permeability is small.

The toner for developing electrostatic images of the present invention usually has a volume average particle diameter of 2 to 20 µm, preferably 3 to 15 µm, and a particle size distribution (volume average particle diameter / number average particle diameter) of 1.6 or less, preferably A particle size distribution of 1.5 or less is sharp spherical fine particles. When the toner for developing electrostatic images obtained by the production method of the present invention is used, the fixing temperature can be reduced to a low temperature of 80 to 180 ° C, preferably 100 to 150 ° C, and does not aggregate during storage, and is excellent in storageability. .

Image Forming Device

The electrostatic charge image developing toner of the present invention is used in an image forming apparatus using an electrophotographic method.

1 is a sectional view of an example of an image forming apparatus. In this image forming apparatus, as the image bearing member, the photosensitive drum 1 is mounted so as to be freely rotated in the direction of the arrow. The photosensitive drum 1 usually has a structure in which a photoconductive layer is formed on the outer circumference of the conductive support drum. The photoconductive layer is composed of, for example, an organic photoconductor, a selenium photoconductor, a zinc oxide photoconductor, an amorphous silicon photoconductor, or the like.

The charging means 3, the latent image forming means 4, the developing means 5, the transfer means 6 and the cleaning means 2 are arranged around the photosensitive drum 1 along the circumferential direction thereof. The charging means 3 functions to uniformly charge the surface of the photosensitive drum 1 with plus or minus, and besides the charging roll shown in FIG. 1, for example, a corona discharge device, a charging blade, or the like can be used. The latent image forming means 4 irradiates the surface of the photosensitive drum uniformly charged with light corresponding to the image signal in a predetermined pattern to form an electrostatic image on the portion to be irradiated (inverted phenomenon) or electrostatic on a portion to which light is not irradiated. It forms a latent image (normal development method). The latent image forming means 4 is composed of, for example, a combination of a laser device and an optical system or a combination of an LED array and an optical system.

The developing means 5 functions to attach a developer (toner) to the electrostatic latent image formed on the surface of the photosensitive drum 1. The developing means 5 is usually provided with a developing roller 8, a latent image roller blade 9, a receiving means (accommodating casing) 11 of the developer 10, and a developer supply means (supply roller) 12. It is a developing device. The developing roller 8 is arranged opposite to the photosensitive drum 1, and is usually disposed in close proximity to the photosensitive drum 1 so as to rotate in the opposite direction to the photosensitive drum 1. The feed roller 12 is brought into contact with the developing roller 8 to rotate in the same direction as the developing roller 8, and supplies the toner 10 to the outer circumference of the developing roller 8. When the developing roller 8 is rotated in the developing apparatus, the toner 10 in the developer accommodating means 11 is attached to the outer circumferential surface by the electrostatic force due to friction or the like. The developing roller blade 9 abuts against the outer peripheral surface of the rotating developing roller 8 to adjust the thickness of the toner layer formed on the outer peripheral surface of the developing roller 8. In the reverse development method, a bias voltage is applied between the developing roller 8 and the photosensitive drum 1 so that the toner is attached only to the light irradiation part of the photosensitive drum 1, and in the normal development method to attach the toner only to the light non-irradiating part.

The transfer means 6 is for transferring the toner image on the surface of the photosensitive drum 1 formed by the developing means 5 to the transfer material (transfer paper) 7, and for example, corona discharge, in addition to the transfer roller shown in FIG. A device, a transfer belt, or the like can be used. The cleaning means 2 is for cleaning the toner remaining on the surface of the photosensitive drum 1, and is composed of, for example, a cleaning blade or the like. This cleaning means is not necessarily necessary in the case of a method of cleaning at the same time as development.

Therefore, according to the present invention, an accommodating means for accommodating the toner for electrostatic image development obtained by the manufacturing method, a supply means for supplying the toner contained in the accommodating means, an image carrier, and an image carrier are provided opposite to each other. An image forming apparatus is provided having developing means for developing an electrostatic latent image formed on an image carrier using the supplied toner, and a transfer means for transferring the developed toner image onto a transfer material.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited only to these Examples. And parts and% are based on weight unless there is a problem in particular.

The measuring method of the physical property in an Example and a comparative example is as follows.

(1) particle size of toner

The particle size of the toner particles is measured by the Coulter counter (manufactured by Coulter, Inc.) and the volume average particle diameter (dv) and the particle size distribution, that is, the ratio (dv / dp) of the volume average particle diameter and the number average particle diameter (dp). In the measurement by this Coulter counter, the following parameters are used.

① Aperture Diameter: 100 ㎛

② Medium: Isoton II

③ concentration: 15%

④ Number of particles measured: 50,000

(2) Volume specific resistance of toner

The volume intrinsic resistance of the toner is measured using a dielectric loss measuring instrument (trade name: TRS-10 type, manufactured by Ando Denki Co., Ltd.) under a temperature of 30 ° C. and a frequency of 1 kHz.

(3) fixing temperature of toner

Toner image evaluation is carried out with a printer adapted to change the temperature of the fixing roll portion of a commercially available nonmagnetic component development method printer. The temperature of 80% of fixation rate is evaluated by fixing temperature. The fixing test is carried out by changing the temperature of the fixing roll of the printer and measuring the fixing rate at each temperature to obtain the relationship between the temperature and the fixing rate. The fixation rate is calculated from the ratio of the image density before and after the tape peeling operation in the completely black area on the test paper printed by the modified printer. That is, if the image density before tape peeling is before ID and the image density after tape peeling is after ID,

Settlement Rate (%) = (After ID / Before ID) × 100

to be. In this case, the completely black area means an area controlled to attach toner to all dots (virtual for controlling the printer upsetting part) inside the area. The tape peeling operation is a series of peeling the adhesive tape in the direction along the paper at a constant speed after attaching the adhesive tape (Scotch Mending Tape 810-3-18 manufactured by Sumitomo 3M Co., Ltd.) to the measurement part for test paper and pressing it at a constant pressure. Is the operation of. In addition, the image density is measured using a reflective image density meter manufactured by McBeth.

(4) Toner Storage

In evaluating the storage property, the toner sample was placed in a sealed container and sealed, soaked in a constant temperature water bath controlled by temperature, taken out after a predetermined time, and the weight of the aggregated toner was measured. The sample taken out of the container was transferred to a 42-mesh sieve so as not to destroy the structure as much as possible, and vibrated for 30 seconds by setting the vibration intensity to 4.5 with the REOSTAT of the powder measuring instrument (manufactured by Hosogawa Micron Co., Ltd.), and remaining on the sieve Was measured to give the weight of the aggregated toner. The aggregation rate (wt%) of the toner is calculated from the weight of the aggregated toner and the weight of the sample. Toner retention is evaluated in the following four steps.

◎: coagulation rate is less than 5% by weight,

(Circle): Cohesion rate is 5 weight% or more and less than 10 weight%,

(Triangle | delta): 10 weight% or more and less than 50 weight%,

X: Coagulation rate is 50 weight% or more.

(5) OHP permeability

The temperature of the fixing roll of the remodeled printer described above is set to 180 ° C, and is printed using a commercially available OHP (Transparency) manufactured by Uchida Yoko Co., Ltd. to evaluate the OHP permeability of the toner. Permeation or impermeability is evaluated by visually observing whether the factor has permeated the OHP sheet.

Example 1

60 parts of styrene, 40 parts of n-butyl acrylate, 5 parts of carbon black (made by DEG Corporation, trade name Printex 150T), 1 part of an antistatic agent (made by Hodogaya Chemical Co., Ltd., brand name spiron black TRH), divinylbenzene 0.3 Part and 2 parts of 2,2-azobisisobutylonitrile (calculated Tg of the core component obtained, Tg = 20 ° C) were 6,000 rpm by a TK-type homomixer (manufactured by Tokushugi Kako Co., Ltd.), a mixer having high shear force. The monomer composition for core components which was stirred and mixed at the rotational speed of and uniformly dispersed was prepared.

On the other hand, an aqueous solution in which 9.8 parts of magnesium chloride (aqueous polyvalent metal salt) was dissolved in 250 parts of ion-exchanged water, and an aqueous solution of 6.9 parts of sodium hydroxide (alkali metal hydroxide) in 50 parts of ion-exchanged water were gradually added under stirring to obtain magnesium hydroxide colloid ( A poorly water-soluble metal hydroxide colloid) dispersion is prepared. The particle size distribution of the colloid produced was measured with a microtrack particle size distribution analyzer (manufactured by Nikkiso Corporation). As a result, the particle size was D ₅₀ (50% cumulative value of the individual particle size distribution) of 0.38 µm, and D ₉₀ (90% of the individual particle size distribution). Cumulative value) was 0.82 mu m. The following parameters are used for the measurement by this microtrack particle size distribution analyzer.

Measuring range: 0.12 to 704 μm

Measurement time: 30 seconds

Medium: Ion Exchange Water

On the other hand, 10 parts of styrene (calculated Tg = 100 ° C) and 100 parts of water are microdispersed by an ultrasonic emulsifier (manufactured by Cionpa Co., Ltd.) to prepare a dispersion of the monomer for shell components. The particle size of the undispersed monomer droplets in the ultrasonic and emulsifiers was obtained by adding the obtained droplets in a 1% sodium hexamethaphosphate aqueous solution at a concentration of 3%, and measured by a microtrack particle size distribution analyzer. As a result, D ₉₀ was 1.6 µm.

The polymerizable monomer composition for the core component was added to the magnesium hydroxide colloidal dispersion obtained as described above, and the droplets of the monomer composition for the core component were subjected to high shear stirring at a speed of 8,000 rpm using a TK-type homomixer (monomer composition particles). Assemble The aqueous dispersion of the granulated core composition for the core component was placed in a reactor equipped with a stirring blade, and the polymerization reaction was started at 65 DEG C. When the polymerization conversion rate reached 80%, a dispersion of the monomer for shell component was added to the reactor. Subsequently, after adding 1 part of 1% potassium persulfate aqueous solution as a water-soluble radical initiator, the reaction is continued for 5 hours to complete the reaction to obtain an aqueous dispersion of polymer particles (toner particles). And the number average particle diameter (dp) of the colored polymer particle of the core component of 80% of polymerization conversion ratio measured by the Coulter counter method was 5.7 micrometers.

The particle size of the toner particles after the completion of the polymerization reaction was measured by a Coulter counter (manufactured by Coulter). As a result, the volume average particle diameter (dv) was 5.8 µm, and the particle size distribution, that is, the volume average particle diameter (dv) and the number average particle diameter (dp). ) Ratio (dv / dp) was 1.32. After the obtained toner particles were wrapped with epoxy resin, they were cut into 1 mm thick with an ultramicrotom, and the cut surface was observed with a transmission electron microscope. As a result, a shell having a thickness of 0.2 μm was confirmed.

After stirring the aqueous dispersion of the polymer particles obtained as described above, the pH of the system was adjusted to 4 or less with sulfuric acid, followed by acid washing (25 ° C., 10 minutes), and water was separated by filtration, 500 parts of ion-exchanged water are added, and the water is reslurryed and washed with water. Thereafter, dehydration and washing with water are repeated several times, and the solids are separated by filtration and then dried at 50 ° C. overnight with a drier to obtain toner particles.

To 100 parts of the toner particles obtained as described above were added 0.3 part of hydrophobized colloidal silica (trade name: R-972, manufactured by Nippon Aerodyl Co., Ltd.), and mixed using a Henschel mixer to prepare a toner. As a result of measuring the volume specific resistance of the toner thus obtained, it was 1.0 × 10 ¹¹ Pa · cm.

It was 130 degreeC when the fixing temperature was measured using the toner obtained by the above. In addition, the shelf life of this toner was very good (evaluation = ◎). The results are shown in Table 1. In other image evaluations, an image having a high image density and a very good resolution without blur and spots is obtained.

Example 2

In Example 1, the same operation as in Example 1 was carried out except that the dispersion and the 1% potassium persulfate aqueous solution of the shell component monomer added during the polymerization were added when the polymerization conversion ratio of the monomer composition for the core component was 93%. Obtain a polymerized toner. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 3

In Example 1, a polymerization toner was obtained in the same manner as in Example 1 except that the amount of styrene of the shell monomer added during polymerization was changed to 20 parts and the amount of 1% aqueous potassium persulfate solution was changed to 2 parts, respectively. . Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Comparative Example 1

In Example 1, a polymerization toner was obtained in the same manner as in Example 1 except that the dispersion of the shell component monomer added during the polymerization and the 1% potassium persulfate aqueous solution were not added. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Comparative Example 2

In Example 1, 10 parts of styrene and 2, 2- azobisisobutyronitrile 0.2 instead of the dispersion of the shell component monomer and the potassium persulfate aqueous solution added when the polymerization conversion ratio of the monomer for core components reached 80%. A polymerized toner was obtained in the same manner as in Example 1 except that a liquid obtained by mixing a part and 100 parts of water was added. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 4

In Example 1, 2,2-azobis-2-methyl-N-1,1-bis (hydroxymethyl) -2-hydroxyethylpropioamide is used as potassium persulfate as a water-soluble radical initiator to be added during polymerization. A polymerized toner was obtained in the same manner as in Example 1 except for replacing with. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 5

In Example 1, operation similar to Example 1 except having changed the quantity of styrene and n-butyl acrylate in the monomer composition for core components into 75 parts of styrene and 25 parts of n-butyl acrylate (calculated Tg = 44 degreeC), respectively. A polymerized toner is obtained by the method. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 6

In Example 1, operation similar to Example 1 except having changed the quantity of styrene and n-butyl acrylate in the monomer composition for core components into 55 parts of styrene and 45 parts of n-butyl acrylate (calculated Tg = 10 degreeC), respectively. A polymerized toner is obtained by the method. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 7

In Example 1, 0.001 part of sodium dodecyl benzene sulfonate (made by Wako Pure Chemical) is added when the monomer for shell components added during superposition | polymerization is subjected to the microdispersion process by an ultrasonic emulsifier. At this time, D ₉₀ of the monomer microdispersed droplets was 0.95 μm. Otherwise, the polymerization toner is obtained in the same manner as in Example 1. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Example 8

In Example 1, a polymerization toner was obtained in the same manner as in Example 1, except that 0.01 part of a charge control agent (Orgent Chemical Co., Ltd. Bontron E-84) was added to the monomer for shell component added during the polymerization. Table 1 shows the measurement results of the particle diameters, fixing temperatures and storage characteristics of the obtained toner particles.

Toner particle size (dv) (㎛) Fusing temperature (℃) Preservation Example 1 5.8 130 ◎ Example 2 5.6 135 ◎ Example 3 6.2 140 ◎ Example 4 5.7 130 ◎ Example 5 6.1 138 ◎ Example 6 6.3 120 ◎ Example 7 5.7 130 ◎ Example 8 5.8 130 ◎ Comparative Example 1 5.7 120 × Comparative Example 2 6.0 125 ×

Example 9 (color toner)

In Example 1, a polymerization toner was obtained in the same manner as in Example 1 except that 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of carbon black. Table 2 shows the measurement results of the toner particle size (dv), the fixing temperature, the storage properties, and the OHP permeability.

Comparative Example 3

In Comparative Example 1, a polymerized toner was obtained in the same manner as in Comparative Example 1 except that 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of carbon black. Table 2 shows the measurement results of the toner particle size (dv), the fixing temperature, the storage properties, and the OHP permeability.

Comparative Example 4

In Comparative Example 1, 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of carbon black, and the amount of styrene and n-butyl acrylate in the monomer composition for the core component was respectively 85 parts of styrene and n-butyl acrylate. Polymerized toner was obtained in the same manner as in Example 1 except for changing to 15 parts. Table 2 shows the measurement results of the toner particle size (dv), the fixing temperature, the storage properties, and the OHP permeability.

Toner particle size (dv) (㎛) Fusing temperature (℃) Preservation OHP Permeability Example 9 6.5 130 ◎ Permeation Comparative Example 3 6.8 120 × Permeation Comparative Example 4 6.2 150 ○ Opacity

Example 10

In Example 10, the Example which replaced the styrene of the monomer for shell components with methyl methacrylate in Example 1, and did not perform the microdispersion process by an ultrasonic emulsifier is shown.

60 parts of styrene, 40 parts of n-butyl acrylate, 5 parts of carbon black (made by DEG Corporation, brand name Printex 150T), 1 part of antistatic agent (made by Hodogaya Chemical Co., Ltd., brand name spiron black TRH), divinylbenzene 0.3 part and 2 parts of 2,2- azobisisobutylonitrile (calculated Tg of core component obtained Tg = 20 degreeC) were made into 6,000 by the TK type homomixer (made by Toku-Shig Kako Co., Ltd.) which is a high shear force mixer. The monomer composition for core components which stirred and mixed at the rotation speed of rpm, and was uniformly dispersed is prepared.

On the other hand, an aqueous solution in which 9.8 parts of magnesium chloride (aqueous polyvalent metal salt) was dissolved in 250 parts of ion-exchanged water, and an aqueous solution of 6.9 parts of sodium hydroxide (alkali metal hydroxide) in 50 parts of ion-exchanged water were gradually added under stirring to obtain magnesium hydroxide colloid ( A poorly water-soluble metal hydroxide colloid) dispersion is prepared. The particle size distribution of the colloid produced was measured with a microtrack particle size distribution analyzer (manufactured by Nikkiso Corporation). As a result, the particle size was D ₅₀ (50% cumulative value of the individual particle size distribution) of 0.38 µm, and D ₉₀ (90% of the individual particle size distribution). Cumulative value) was 0.82 mu m.

The polymerizable monomer composition for the core component was added to the magnesium hydroxide colloidal dispersion obtained as described above, and the droplets of the monomer composition for the core component were subjected to high shear stirring at a speed of 8,000 rpm using a TK-type homomixer (monomer composition particles). Assemble The aqueous dispersion of the granulated core composition for the core component was placed in a reactor equipped with a stirring blade, and the polymerization reaction was started at 65 ° C. When the polymerization conversion rate reached 80%, methyl methacrylate (calculated Tg) was used as the monomer for the shell component. 10 parts) is added to the reactor, and then 1 part of a 1% aqueous potassium persulfate aqueous solution is added as a water-soluble radical initiator, and then the reaction is continued for 5 hours to complete the reaction to obtain an aqueous dispersion of polymer particles (toner particles).

The particle size of the toner particles after the completion of the polymerization reaction was measured by a Coulter counter (manufactured by Coulter, Inc.). As a result, the volume average particle diameter (dv) was 5.7 µm, and the particle size distribution, that is, the volume average particle diameter (dv) and the number average particle diameter (dp). ) Ratio (dv / dp) was 1.31. After the obtained toner particles were wrapped with epoxy resin, they were cut into 1 mm thick with an ultramicrotom, and the cut surface was observed with a transmission electron microscope. As a result, a shell having a thickness of 0.2 μm was confirmed.

After stirring the aqueous dispersion of the polymer particles obtained as described above, the acid pH of the system was adjusted to 4 or less with sulfuric acid (25 DEG C, 10 minutes), and water was separated by filtration. Add 500 parts and reslurries to wash with water. Thereafter, dehydration and washing with water are repeated several times, and the solids are separated by filtration and then dried at 50 ° C. overnight with a drier to obtain toner particles.

To 100 parts of the toner particles obtained as described above were added 0.3 part of hydrophobized colloidal silica (trade name: R-972, manufactured by Nippon Aerodyl Co., Ltd.), and mixed using a Henschel mixer to prepare a toner. As a result of measuring the volume specific resistance of the toner thus obtained, it was 1.5 × 10 ¹¹ Pa · cm.

It was 130 degreeC when the fixing temperature was measured using the toner obtained by the above. In addition, the shelf life of this toner was very good (evaluation = ◎). The results are shown in Table 3. In other image evaluations, an image having a high image density and a very good resolution without blur and spots is obtained.

Example 11

In Example 10, the polymerization toner was prepared in the same manner as in Example 10, except that methyl methacrylate and 1% potassium persulfate aqueous solution added during the polymerization were added when the polymerization conversion ratio of the monomer composition for core components was 93%. Get Table 3 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 12

In Example 10, the polymerization toner was obtained in the same manner as in Example 10, except that the amount of methyl methacrylate added during the polymerization was changed to 20 and the amount of the 1% potassium persulfate aqueous solution was changed to 2 parts, respectively. Table 3 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 13

In Example 10, a polymerized toner was obtained in the same manner as in Example 10 except that the methyl methacrylate as the monomer for the shell component was changed to acrylonitrile (calculated Tg = 125 ° C). Table 3 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Toner particle size (dv) (㎛) Fusing temperature (℃) Preservation Example 10 5.7 130 ◎ Example 11 5.8 140 ◎ Example 12 6.0 144 ◎ Example 13 6.1 145 ◎

Example 14

In Example 10, a polymerized toner was obtained in the same manner as in Example 10 except that 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of carbon black. The evaluation result of this polymerized toner was that the toner particle size (dv) was 5.9 mu m, the fixing temperature was 130 deg. C, the shelf life was good, and the OHP permeability was permeable.

Example 15

60 parts of styrene, 40 parts of n-butyl acrylate, 5 parts of carbon black (made by DEG Corporation, brand name Printex 150T), 1 part of antistatic agent (made by Hodogaya Chemical Co., Ltd., brand name spiron black TRH), divinylbenzene 0.3 part and 2 parts of 2,2- azobisisobutylonitrile (calculated Tg of core component obtained Tg = 20 degreeC) were made into 6,000 by the TK type homomixer (made by Toku-Shig Kako Co., Ltd.) which is a high shear force mixer. The monomer composition for core components which stirred and mixed at the rotation speed of rpm, and was uniformly dispersed is prepared.

On the other hand, an aqueous solution in which 9.8 parts of magnesium chloride (aqueous polyvalent metal salt) was dissolved in 250 parts of ion-exchanged water, and an aqueous solution of 6.9 parts of sodium hydroxide (alkali metal hydroxide) in 50 parts of ion-exchanged water were gradually added under stirring to obtain magnesium hydroxide colloid ( A poorly water-soluble metal hydroxide colloid) dispersion is prepared. The particle size distribution of the colloid produced was measured with a microtrack particle size distribution analyzer (manufactured by Nikkiso Corporation). As a result, the particle size was D ₅₀ (50% cumulative value of the individual particle size distribution) of 0.38 µm, and D ₉₀ (90% of the individual particle size distribution). Cumulative value) was 0.82 mu m. The following parameters are used for the measurement by this microtrack particle size distribution analyzer.

Measuring range: 0.12 to 704 μm

Measurement time: 30 seconds

Medium: Ion Exchange Water

The polymerizable monomer composition for the core component was added to the magnesium hydroxide colloidal dispersion obtained as described above, and the droplets of the monomer composition for the core component were subjected to high shear stirring at a speed of 8,000 rpm using a TK-type homomixer (monomer composition particles). Assemble The aqueous dispersion of the granulated core composition for core components was placed in a reactor equipped with a stirring blade to start a polymerization reaction at 65 deg. C, and 20 parts of methanol was added when the polymerization conversion rate reached 80%. After 10 minutes, 10 parts of styrene (calculated Tg = 100 DEG C) was added to the reactor as a monomer for the shell component, and then 1 part of 1% aqueous potassium persulfate solution was added, and then the reaction was continued for 5 hours to complete the reaction. An aqueous dispersion of particles) is obtained.

The particle size of the toner particles after the completion of the polymerization reaction was measured by a Coulter counter (manufactured by Coulter, Inc.). As a result, the volume average particle diameter (dv) was 5.7 µm, and the particle size distribution, that is, the volume average particle diameter (dv) and the number average particle diameter (dp). ) Ratio (dv / dp) was 1.31. After the obtained toner particles were wrapped with epoxy resin, they were cut into 1 mm thick with an ultramicrotom, and the cut surface was observed with a transmission electron microscope. As a result, a shell having a thickness of 0.2 μm was confirmed.

After stirring the aqueous dispersion of the polymer particles obtained as described above, the acid pH of the system was adjusted to 4 or less with sulfuric acid (25 DEG C, 10 minutes), and water was separated by filtration. Add 500 parts and reslurries to wash with water. Thereafter, dehydration and washing with water are repeated several times, and the solids are separated by filtration and then dried at 50 ° C. overnight with a drier to obtain toner particles.

To 100 parts of the toner particles obtained as described above were added 0.3 part of hydrophobized colloidal silica (trade name: R-972, manufactured by Nippon Aerodyl Co., Ltd.), and mixed using a Henschel mixer to prepare a toner. As a result of measuring the volume specific resistance of the toner thus obtained, it was 1.8 × 10 ¹¹ Pa · cm.

It was 130 degreeC when the fixing temperature was measured using the toner obtained by the above. In addition, the shelf life of this toner was very good (evaluation = ◎). The results are shown in Table 4. In other image evaluations, an image having a high image density and a very good resolution without blur and spots is obtained.

Example 16

In Example 15, a polymerization toner was obtained in the same manner as in Example 15 except that styrene and 1% potassium persulfate aqueous solution added during the polymerization were added when the polymerization conversion ratio of the monomer composition for core components was 93%. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 17

In Example 15, the polymerization toner was obtained in the same manner as in Example 15, except that the amount of styrene added during the polymerization was changed to 20 and the amount of 1% aqueous potassium persulfate solution was changed to 2 parts, respectively. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 18

In Example 15, the polymerization toner was obtained in the same manner as in Example 15 except that the methanol added during the polymerization was changed to acetone. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 19

In Example 15, when the polymerization conversion ratio in the first step (manufacturing step of the core component polymer particles) reached 80%, 10 parts of methyl methacrylate (calculated Tg = 105 ° C) was added as the monomer for the first shell component. Add. Subsequently, after adding 1 part of 1% potassium persulfate aqueous solution and continuing reaction for 1 hour, 20 parts of methanol are added. After 10 minutes, 5 parts of styrene (calculated Tg = 100 DEG C) was added to the reactor as a monomer for the second shell component, followed by addition of 0.5 parts of 0.5% aqueous potassium persulfate solution, and then the reaction was continued for 5 hours to complete the reaction. Polymer particles (toner particles) are obtained. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Example 20

In Example 15, a polymerization toner was obtained in the same manner as in Example 15, except that 0.01 part of a charge control agent (Orene Chemical Co., Ltd. Bontron E-84) was added to the styrene added during the polymerization. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles.

Comparative Example 5

In Example 15, the polymerization toner was obtained in the same manner as in Example 15 except that the methanol, styrene, and potassium persulfate aqueous solutions added during the polymerization were not added. Table 4 shows the measurement results of the particle diameter, fixing temperature, and storage properties of the obtained toner particles. The storage life evaluation of the obtained polymerized toner was deteriorated as x.

Toner particle size (dv) (㎛) Fusing temperature (℃) Preservation Example 15 5.7 130 ◎ Example 16 5.7 136 ◎ Example 17 6.0 142 ◎ Example 18 5.9 140 ◎ Example 19 5.8 148 ◎ Example 20 5.7 10 ◎ Comparative Example 5 5.7 120 ×

Example 21

In Example 15, a polymerized toner was obtained in the same manner as in Example 15 except that 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of carbon black. Table 5 shows the measurement results of the particle diameters, fixing temperatures, storage properties, and OHP permeability of the obtained toner particles.

Comparative Example 6

In Comparative Example 5, a polymerization toner was obtained in the same manner as in Comparative Example 5 except that 5 parts of phthalocyanine blue (GNX manufactured by Sumitomo Chemical Co., Ltd.) was used instead of 5 parts of carbon black. Table 5 shows the measurement results of the particle diameters, fixing temperatures, storage properties, and OHP permeability of the obtained toner particles.

Comparative Example 7

In Comparative Example 5, 5 parts of phthalocyanine blue (GNX manufactured by Sumitomogagaku Co., Ltd.) was used instead of 5 parts of carbon black, and the monomer component was 85 parts of styrene and 15 parts of n-butylacrylate (calculated Tg = 66 of copolymer). Polymerized toner was obtained in the same manner as in Comparative Example 5 except for changing to C). Table 5 shows the measurement results of the particle diameters, fixing temperatures, storage properties, and OHP permeability of the obtained toner particles.

Toner particle size (dv) (㎛) Fusing temperature (℃) Preservation OHP Permeability Example 21 5.9 130 ◎ Permeation Comparative Example 6 6.8 120 × Permeation Comparative Example 7 6.2 150 ○ Opacity

Example 22

In Example 15, t-butylperoxy-2-ethylhexanoate was used instead of 2,2-azobisisobutylonitrile as the oil-soluble initiator used in the polymerization of the monomer composition for the core component, and the reaction temperature was used. Polymerized toner was obtained in the same manner as in Example 15 except that the temperature was 90 deg. The obtained polymerized toner exhibits fixing temperatures and storage properties substantially the same as those of the polymerized toner obtained in Example 15. As a result of analyzing the residual monomer amount by the following method, it can be seen that the residual monomer amount of the polymerized toner of Example 15 was significantly reduced to 230 ppm, while the residual monomer amount of the polymerized toner of Example 15 was 690 ppm. The results are shown in Table 6.

Analysis of residual monomer amount

The amount of monomer remaining in the polymerized toner is measured by gas chromatography. 0.2 g of the polymerized toner serving as a sample is precisely weighed into a 10 ml volumetric flask, and methanol is added to the mark, followed by infiltration for 5 hours. Subsequently, after insoluble matter is precipitated by centrifugation, 1 µl of the supernatant is injected into GC-MS to carry out monomer analysis. GC-MS conditions are described below.

Column: HP-1, 0.25 mm × 30 mm, 1 μm

Oven: Temperature rising to 260 ° C. at 10 ° C./min.

INJ. : 220 ℃

DET. : 260 ℃

Examples 23-25

The polymerization toner was obtained in the same manner as in Example 22 except that the type of oil-soluble initiator was changed to that shown in Table 6 and the polymerization temperature shown in Table 6 was obtained. Each obtained polymerized toner exhibits fixing temperatures and storage properties substantially the same as those of the polymerized toner obtained in Example 15.

Table 6 shows measurement results such as the type of oil-soluble initiator, the amount of residual monomers, and malodor determination.

Example 22 23 24 25 Usability Initiator Kinds t-butylperoxy (2-ethylhexanoate) Succinicamide peroxide t-hexyl peroxy-2-ethylhexanoate t-butylperoxyisobutylate 10 hours half-life temperature (℃) 72 66 70 77 Molecular Weight 216 234 244 160 Polymerization temperature (℃) 90 85 90 95 Polymerization state ○ ○ ○ ○ Spherical diagram 1.1 1.1 1.1 1.2 Odor determination ○ ○ ○ ○ Toner Water Content (%) 0.1 0.1 0.1 0.2 Toner Heat Loss (%) 1.1 1.0 0.8 0.9 Remaining monomer (ppm) 230 420 340 400 (Footnote) (1) Moisture content was measured by the Cul Fischer moisture meter. (2) Loss of heating was measured by the weight change rate of 105 ℃ × 1 hour. (3) Odor was randomly selected from 10 people When odor was felt, x was used.

According to the production method of the present invention, there is provided a toner for electrostatic image development having a low fixing temperature, good OHP permeability and excellent storage life.

Claims (26)

A method for producing an electrostatic charge image developing toner comprising colored polymer particles by suspension polymerization of a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant, (1) In the aqueous dispersion medium, the monomer composition for core components containing at least one kind of monomer for core component and colorant which forms a polymer having a glass transition temperature of 80 ° C. or lower until the polymerization conversion ratio of this monomer becomes 80% or more. A first step of suspending polymerization to form colored polymer particles as core components; and (2) at least one shell component monomer or shell component containing the monomer, which forms a polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component in the reaction system containing colored polymer particles as the core component By adding a monomer composition and a water-soluble radical initiator, and performing a polymerization reaction, core components 40-99 are carried out by two or more processes of the 2nd process of forming the coating layer of the polymer which becomes a shell component on the surface of the colored polymer particle which becomes a core component. A method for producing a toner for electrostatic image development, comprising producing capsule-shaped colored polymer particles having a core-shell structure composed of weight% and shell components 1 to 60 weight%. The shell component monomer or the shell component monomer composition containing the monomer is added to the reaction system in the second step as an aqueous suspension of droplets having a smaller number average particle diameter than colored polymer particles serving as core components. Process for producing a polymerization reaction. The polymerization reaction according to claim 1, wherein in the second step, a polymerization reaction is performed by adding an organic solvent having a solubility in water at 20 ° C of 5% by weight or more with the shell component monomer or the shell component monomer composition containing the monomer to the reaction system. Manufacturing method. The production method according to claim 1 or 2, wherein the monomer for shell component is a monomer having a solubility in water of 20 ° C of at least 0.1% by weight. The method according to claim 2 or 3, wherein the monomer for shell component is a monomer having a solubility in water of 20 ° C of less than 0.1% by weight. The polymerization method according to any one of claims 1 to 5, wherein the water-soluble radical initiator is added to the reaction system simultaneously with or after the addition of the shell component monomer or the shell composition monomer composition containing the monomer composition in the second step. A manufacturing method for carrying out. The manufacturing method of any one of Claims 1-6 in which the monomer composition for shell components contains a monomer for shell components, and a charge control agent. The production method according to any one of claims 1 to 7, wherein the aqueous dispersion medium contains, as a dispersant, a poorly water-soluble metal hydroxide colloid produced by the reaction in an aqueous phase of a water-soluble polyvalent metal salt and an alkali metal hydroxide salt. The manufacturing method of Claim 3 which adds an organic solvent to a reaction system in a 2nd process, and then superposes | polymerizes by adding the monomer for shell components or the monomer composition for shell components containing this monomer. 4. The first shell component monomer or the first shell component containing the monomer according to claim 3, wherein the solubility in water at 20 DEG C is 0.1% by weight or more before adding the organic solvent to the reaction system in the second step. The monomer composition is added to carry out the polymerization reaction, and (ii) the second shell component monomer having a solubility in organic solvent and water at 20 ° C. of less than 0.1 wt% in the reaction system or the monomer for the second shell component containing the monomer. The manufacturing method which superposes | polymerizes by adding a composition. The method according to claim 10, wherein the polymerization is carried out by adding a water-soluble radical initiator simultaneously with or after the addition of the first shell component monomer or the first shell component monomer composition containing the monomer. The method according to claim 10, wherein the polymerization is carried out by adding a water-soluble radical initiator simultaneously with or after addition of the second shell component monomer or the second shell component monomer composition containing the monomer. The production method according to any one of claims 1 to 12, wherein the monomer for the core component is polymerized in the first step by an oil-soluble polymerization initiator. The production method according to any one of claims 1 to 13, wherein the monomer composition for the core component contains an oil-soluble polymerization initiator. The production method according to claim 13 or 14, wherein the oil-soluble initiator is an organic peroxide having a half-life temperature of 60 hours to 80 ° C and a molecular weight of 250 or less. A method for producing an electrostatic charge image developing toner comprising colored polymer particles by suspension polymerization of a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant, (1) In the aqueous dispersion medium, the monomer composition for core components containing at least one kind of monomer for core component and colorant which forms a polymer having a glass transition temperature of 80 ° C. or lower until the polymerization conversion ratio of this monomer becomes 80% or more. A first step of suspending polymerization to form colored polymer particles as core components; and (2) at least one shell component monomer or shell component containing the monomer, which forms a polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component in the reaction system containing colored polymer particles as the core component The monomer composition is added as an aqueous suspension of droplets having a smaller number average particle diameter than the colored polymer particles serving as the core component and subjected to a polymerization reaction, thereby forming a coating layer of the polymer serving as a shell on the surface of the colored polymer particles serving as the core component. A toner for electrostatic image development, wherein a core-shell structured colored polymer particle composed of 40 to 99% by weight of the core component and 1 to 60% by weight of the shell component is produced by two or more steps of the second step. Manufacturing method. The production method according to claim 16, wherein the monomer for core component is polymerized with an oil-soluble polymerization initiator in the first step, and the monomer for shell component is polymerized with a water-soluble radical initiator in the second step. 18. The process according to claim 16 or 17, wherein the monomer for shell component is a monomer having a solubility in water at 20 ° C of less than 0.1% by weight. 19. The method according to any one of claims 16 to 18, wherein the aqueous dispersion medium contains, as a dispersant, a poorly water-soluble metal hydroxide colloid produced by reaction in an aqueous phase of a water-soluble polyvalent metal alkali metal hydroxide. A method for producing an electrostatic charge image developing toner comprising colored polymer particles by suspension polymerization of a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersant, (1) In the aqueous dispersion medium, the monomer composition for core components containing at least one kind of monomer for core component and colorant which forms a polymer having a glass transition temperature of 80 ° C. or lower until the polymerization conversion ratio of this monomer becomes 80% or more. A first step of suspending polymerization to form colored polymer particles as core components; and (2) at least one shell component monomer or shell component containing the monomer, which forms a polymer having a glass transition temperature higher than the glass transition temperature of the polymer of the core component in the reaction system containing colored polymer particles as the core component 2nd process of forming the coating layer of the polymer which becomes a shell component on the surface of the colored polymer particle which becomes a core component by carrying out superposition | polymerization reaction by adding the organic solvent whose solubility to water of 20 degreeC is 5 weight% or more with a monomer composition. A method for producing a toner for electrostatic image development, comprising producing core-shell structured colored polymer particles composed of 40 to 99% by weight of the core component and 1 to 60% by weight of the shell component by at least two processes. . The production method according to claim 20, wherein the monomer for core component is polymerized with an oil-soluble polymerization initiator in the first step, and the monomer for shell component is polymerized with a water-soluble radical initiator in the second step. 22. The method according to claim 20 or 21, wherein the monomer for shell component is a monomer having a solubility in water of 20 ° C of less than 0.1% by weight. 23. The method according to any one of claims 20 to 22, wherein the aqueous dispersion medium contains, as a dispersant, a poorly water-soluble metal hydroxide colloid produced by a reaction in an aqueous phase of a water-soluble polyvalent metal salt and an alkali metal hydroxide salt. The monomer for use in any one of claims 20 to 23, or a monomer for use in the first shell component having a solubility in water of 20 ° C at least 0.1% by weight before adding the organic solvent to the reaction system (i) in the second step. After the polymerization reaction was carried out by adding the monomer composition for first shell component containing (ii), and then (ii) an organic solvent was added to the reaction system, the second shell component monomer having a solubility in water at 20 ° C. of less than 0.1% by weight. Or the manufacturing method which superposes | polymerizes by adding the monomer composition for 2nd shell components containing this monomer. A toner for electrostatic image development obtained by the manufacturing method according to any one of claims 1 to 25. 25. An accommodating means (1) for accommodating the electrostatic charge image developing toner according to claim 25, a supply means (2) for supplying the toner contained in the accommodating means (2), an image carrier (3), and an opposite to the image carrier, toner supplied by the supply means And developing means (4) for developing the electrostatic latent image formed on the image carrier using the transfer means, and transfer means (5) for transferring the developed toner image to the transfer material.