JP2016148864A - Manufacturing method of toner particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of toner particles in toner that has improved low-temperature fixability by adding a crystalline resin, the toner particles having sufficient low-temperature fixability, and excellent fluidity designed for acceleration of a developing process.SOLUTION: There is provided a manufacturing method of toner particles containing a binder resin including a styrene-acrylic resin as a main component, colorant, and crystalline resin, the method comprising the step of manufacturing resin particles by a suspension polymerization method or a dissolution suspension method, and then heating and holding the resin particles in an aqueous medium at a temperature equal to or higher than the intermediate point glass transition temperature of the binder resin and equal to or lower than the melting start temperature of the crystalline resin for half an hour or more.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing toner particles used for forming a toner image by developing an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, or toner jet recording.

In recent years, there has been a demand for low power consumption and high speed in printers and copiers, and in order to satisfy these demands, improvements in the performance of the toner itself have been required. That is, it is desired to realize a toner that can be fixed with low energy and can withstand a high speed development system.
In order to satisfy these requirements, it is necessary to obtain high fluidity and strength in order to cope with high-speed development while softening the toner, but these characteristics are generally considered to be in a trade-off relationship. ing. To solve this problem, toners with a crystalline resin with excellent response speed to heat have been studied. However, simple addition cannot fully utilize the characteristics, and development such as toner fluidity is particularly difficult. The characteristics related to sex may be impaired. For this reason, toners that have been devised in various ways to utilize the characteristics of the crystalline resin have been proposed. Specifically, a phenomenon is used in which, when a crystalline resin is placed at a temperature lower than the melting point of the crystalline resin for a long time, crystals of the crystalline resin grow and crystallinity is improved.
For example, Patent Document 1 proposes a toner manufacturing method including a step of storing a toner containing a crystalline resin at a temperature of 45 ° C. or higher and 65 ° C. or lower.
However, in the above-described toner manufacturing method, a part of the toner may aggregate due to the storage process at the temperature. Further, by performing this process in a dry process, there is a possibility that the crystalline resin existing in the vicinity of the toner surface moves to the toner surface with crystal growth, and the fluidity of the toner may be remarkably lowered.
Further, in Patent Document 2, in a toner in which a crystalline polyester is added to an amorphous polyester, the toner is heated at a specific temperature below the melting point of the crystalline polyester, and further heated at a specific temperature that is equal to or higher than the temperature and lower than the melting point. Toners for processing have been proposed.
In the toner described above, the crystallinity of the crystalline polyester is improved by performing heat treatment in two steps at a temperature lower than the melting point of the crystalline polyester. However, since amorphous polyester is used for the binder resin, the crystalline polyester is compatible with the binder resin in the toner manufacturing process, and the structure of the binder resin and the crystalline polyester cannot be clearly controlled. Therefore, even when the degree of crystallinity is sufficiently increased, it is extremely difficult to achieve compatibility with structural control that can achieve high fluidity and low-temperature fixability of the toner, and the effects of crystalline polyester can be maximized. I can't say that.
On the other hand, Patent Document 3 proposes a toner that raises the degree of crystallization by setting the temperature in the coalescence process to a specific temperature lower than the melting point of the crystalline resin in the emulsion aggregation toner containing the crystalline resin.
In the above method, the structure control of the binder resin and the crystalline resin is easy. However, since the toner is formed while completely separating the binder resin and the crystalline resin as emulsified particles, the familiarity of the binder resin and the crystalline resin is low, and the effect of the crystalline resin may not be fully exhibited.
As described above, a toner having a low-temperature fixing performance improved by adding a crystalline resin, a toner having sufficient low-temperature fixing performance, excellent fluidity, and capable of responding to high-speed development processes. Is long-awaited.

JP 2006-065015 A JP 2009-128652 A JP 2008-250320 A

The present invention provides a toner that solves the above-described conventional problems.
That is, in a toner in which a low temperature fixing performance is improved by adding a crystalline resin, a method for producing toner particles having sufficient low temperature fixing performance and excellent fluidity in order to cope with a higher development process speed. Is to provide.

A method for producing toner particles containing a binder resin comprising a styrene acrylic resin as a main component, a colorant and a crystalline resin, wherein the resin particles are produced by the following method i) or ii) A step of heating and holding the particles in an aqueous medium at a temperature not lower than the glass transition temperature of the binder resin and not higher than the melting start temperature of the crystalline resin for not less than 0.5 hours. It relates to a manufacturing method.
i) Polymerizable monomer composition containing a polymerizable monomer, a colorant and a crystalline resin is dispersed in an aqueous medium, granulated, and a polymerizable monomer contained in the granulated particles. The particles are polymerized to produce resin particles.
ii) A binder resin, a colorant, and a crystalline resin are dissolved or dispersed in an organic solvent to prepare a resin solution, and the resin solution is dispersed in an aqueous medium, granulated, and the granulated particles Resin particles are produced by removing the contained organic solvent.

  According to the present invention, a toner having improved low-temperature fixing performance by adding a crystalline resin has sufficient low-temperature fixing performance and is excellent in fluidity in order to cope with high-speed development processes. A method for producing particles can be provided.

The method for producing toner particles of the present invention is a method for producing toner particles containing a binder resin, a colorant, and a crystalline resin mainly composed of a styrene acrylic resin, and the following method i) or ii) After the resin particles are produced by the step, the resin particles are heated and held in an aqueous medium at a temperature not lower than the midpoint glass transition temperature of the binder resin and not higher than the melting start temperature of the crystalline resin for not less than 0.5 hours. It is characterized by including.
i) Polymerizable monomer composition containing a polymerizable monomer, a colorant and a crystalline resin is dispersed in an aqueous medium, granulated, and a polymerizable monomer contained in the granulated particles. The particles are polymerized to produce resin particles.
ii) A binder resin, a colorant, and a crystalline resin are dissolved or dispersed in an organic solvent to prepare a resin solution, and the resin solution is dispersed in an aqueous medium, granulated, and the granulated particles Resin particles are produced by removing the contained organic solvent.
Crystalline resin is superior to amorphous resin in terms of thermal responsiveness. It retains sufficient strength at temperatures below the melting point, melts at a specific temperature, and rapidly decreases in viscosity (hereinafter sharp) Also called melt property.) When this feature is applied to toner, further low-temperature fixing can be achieved without lowering the fluidity and strength of the toner.
The sharp melt property of the crystalline resin originates from the fact that molecules are regularly arranged to form a crystalline state. However, when a crystalline resin is simply added to the toner, it is often affected by heat or a solvent during the toner manufacturing process, and the crystalline state of the crystalline resin collapses and partly becomes amorphous. As the number of non-amorphous molecules is smaller and the number of molecules forming a crystalline state is larger (that is, the degree of crystallinity is higher), the above-described sharp melt property is exhibited.
Further, the glass transition temperature of the crystalline resin is generally lower than the melting point. Therefore, since the amorphous part becomes an amorphous resin having a low glass transition temperature, the adverse effect of the crystalline resin on durability and heat resistance increases as the ratio increases.
From the above viewpoints, the present inventors considered that it is important to sufficiently increase the crystallinity of the crystalline resin when introducing the crystalline resin into the toner.
Further, as a result of intensive studies, the present inventors can make more use of the characteristics of the crystalline resin depending on the presence state of the crystalline resin in the toner when the crystalline resin is introduced into the toner. I found. For example, it is possible to obtain better fixability and developability by intentionally arranging the crystalline resin inside the toner or by arranging it near the toner surface.
From the above viewpoint, when introducing the crystalline resin into the toner, the crystalline resin and the binder resin are not compatible with each other while maintaining the crystallinity of the crystalline resin at a sufficiently high level. By controlling the structure to have, it is considered that a toner exhibiting the characteristics of the crystalline resin to the maximum can be obtained, and the present invention has been achieved.
The present invention is a method for producing toner particles containing a binder resin mainly composed of a styrene acrylic resin, a colorant and a crystalline resin. The main component of the binder resin is a styrene acrylic resin, and the resin particles that are the basis of the toner particles are produced by a suspension polymerization method or a dissolution suspension method. Therefore, it is possible to control the structure to have a clear boundary. A method for producing resin particles by the suspension polymerization method and the dissolution suspension method will be described later. By using a styrene acrylic resin as the main component of the binder resin, it is possible to clearly perform phase separation between the binder resin and the crystalline resin. This is considered to be because the phase separation state is maintained even in a temperature condition in which the binder resin and the crystalline resin are melted together when the binder resin and the crystalline resin are mixed. In the case where the binder resin is a polyester-based resin, a clear phase separation state cannot be maintained because the crystalline resin becomes compatible when melted.
When the resin particles are produced by the suspension polymerization method or the dissolution suspension method while maintaining the above phase separation state, the structure of the toner particles can be controlled by the physical properties of the crystalline resin. For example, by setting the polarity or SP value of the crystalline resin to a desired value, the crystalline resin can be encapsulated in the toner particles or taken out to the surface layer of the toner particles. Here, since the main component of the binder resin is a styrene acrylic resin, the effect of the physical properties of the crystalline resin on the structure control is increased. This is considered to be an effect obtained because the styrene acrylic resin does not have a large polarity.
Further, when the suspension polymerization method or the dissolution suspension method is used for the production of the resin particles, the binder resin and the crystalline resin are uniformly dissolved once in the polymerizable monomer or the organic solvent. From this state, the polymerization or solvent removal proceeds, whereby the crystalline resin can be finely dispersed in the resin particles, and the low-temperature fixing effect by the crystalline resin can be maximized. On the other hand, since the influence of the amorphous part of the crystalline resin on the heat resistance and durability is increased, it is important to improve the crystallinity by heating and holding described later.
In addition, when the resin particles are produced while maintaining a state where each material is separated as in the emulsion aggregation method, the familiarity between the binder resin and the crystalline resin is low, and the maximum effect as described above can be obtained. There may not be.

In the present invention, after the resin particles are produced by the above-described method i) or ii), the resin particles in the aqueous medium are not lower than the intermediate glass transition temperature of the binder resin and the melting start temperature of the crystalline resin. The crystallinity of the crystalline resin is improved by heating and holding at the following temperature for 0.5 hours or more.
Since the molecular motion of the binder resin occurs at a temperature equal to or higher than the glass temperature at the midpoint of the binder resin (hereinafter sometimes simply referred to as “Tg”), the non-crystalline resin fixed to the binder resin does not move. The crystallinity is improved by moving the crystallized portion to form a crystal. Furthermore, since the molecular motion of the crystalline resin becomes active as the temperature approaches the melting start temperature of the crystalline resin [hereinafter sometimes simply referred to as “Tms”], the crystals are arranged more quickly. However, in the temperature region above the melting start temperature of the crystalline resin, the crystallinity is not improved because the crystalline resin melts. In the present invention, when the suspension polymerization method is used, the midpoint glass transition temperature (° C) of the binder resin is a measured value of the midpoint glass transition temperature (° C) of the resin particles produced by the suspension polymerization method. It was.
In the above temperature range, the crystallinity of the crystalline resin can be sufficiently increased by heating and holding for 0.5 hour or more. When the heating and holding time is less than 0.5 hours, the molecules of the crystalline resin are not sufficiently transferred, and the crystallinity is not improved to a desired state. The time required for the crystalline state to stabilize in a certain state varies depending on the type of crystalline resin and the processing temperature, but if it is 0.5 hour or longer, the crystallinity of the crystalline resin can be sufficiently increased. It is. In addition, the degree of crystallinity does not change even if a heat holding treatment for a certain time or longer is performed. This is because the crystalline state of the crystalline resin used is stabilized in a constant state.
In the present invention, the heating and holding time is preferably 0.5 hours or more and 24.0 hours or less, and more preferably 0.5 hours or more and 12.0 hours or less.
Further, in the present invention, the crystallinity can be increased without destroying the structure having a clear boundary between the crystalline resin and the binder resin which are retained by the resin particles produced by a specific method. is important. This makes it possible to obtain toner particles that are excellent in low-temperature fixability and excellent in fluidity. In order to achieve this, the heating and holding step of holding in the above temperature range is performed in an aqueous medium. By performing heating and holding in an aqueous medium, it becomes possible to prevent the crystalline resin existing inside the resin particles from appearing on the surface of the resin particles, or to maintain the shape of the resin particles themselves. When heated and held in a dry system rather than in an aqueous medium, a part of the crystalline resin present inside the resin particles often appears on the surface of the resin particles.

In the present invention, the crystalline resin is preferably a crystalline polyester. When the crystalline resin is a crystalline polyester, resin particles are produced while maintaining a clear phase separation between the styrene acrylic resin, which is the main component of the binder resin, and the crystalline resin. Therefore, further clear structural control becomes possible. In addition, crystalline polyester has a higher molecular weight and higher strength than a crystalline resin such as paraffin resin, and therefore it is difficult to impair the developability and durability of toner particles when present inside and on the surface of toner particles.
In the present invention, the acid value of the crystalline resin is preferably 0.1 mgKOH / g or more and 50.0 mgKOH / g or less. Further, when the acid value is 0.1 mgKOH / g or more and less than 15.0 mgKOH / g, the ratio of the crystalline resin present in the toner particles is increased. As a result, it is possible to obtain a toner having excellent fluidity and chargeability while exhibiting the low-temperature fixing effect of the crystalline resin. In order to further enhance the effect, the acid value may be 0.1 mgKOH / g or more and 10.0 mgKOH / g or less.
On the other hand, when the acid value is 15.0 mgKOH / g or more and 50.0 mgKOH / g or less, the ratio of the crystalline resin existing in the vicinity of the surface of the toner particles increases. As a result, a toner exhibiting excellent low-temperature fixability can be obtained even when the fixing pressure is lowered particularly in the fixing step. In order to further enhance the effect, the acid value is more preferably 25.0 mgKOH / g or more and 50.0 mgKOH / g or less. When the acid value is higher than 50.0 mgKOH / g, the granulating property of the resin particles tends to be lowered, and the fluidity of the toner particles may be lowered particularly in a high humidity environment. The acid value of the crystalline resin can be controlled by the type and ratio of monomers constituting the crystalline resin. A method for observing the crystalline resin in the toner particles and a method for measuring the acid value of the crystalline resin will be described later.

In order to facilitate the compatibility of the structure control and the crystallinity of the crystalline resin in the present invention, the melting start temperature [Tms (° C.)] of the crystalline resin is 50 ° C. or higher and 100 ° C. or lower. It is preferable that the starting temperature is higher than the midpoint glass transition temperature [Tg (° C.)] of the binder resin [Tms (° C.)> Tg (° C.)]. When the melting start temperature of the crystalline resin is 50 ° C. or higher and 100 ° C. or lower, excellent low-temperature fixability can be obtained while suppressing the influence on heat resistance when introduced into the toner. Further, in the heating and holding described above, the crystallinity is rapidly improved as the holding temperature is closer to [Tms (° C.)] within the temperature range below the melting start temperature [Tms (° C.)] of the crystalline resin. . On the other hand, when heated and held at a temperature significantly higher than the midpoint glass transition temperature [Tg (° C.)] of the binder resin, the structural control performed in the resin particle manufacturing process may be lost. Even when a binder resin having a midpoint glass transition temperature [Tg (° C.)] capable of fixing at a low temperature is used when the melting start temperature [Tms (° C.)] of the crystalline resin is in the above range, the structure It becomes possible to make the crystalline resin have a higher degree of crystallinity while maintaining control. Note that the melting start temperature [Tms (° C.)] of the crystalline resin can be controlled by the type of monomer constituting the crystalline resin. Moreover, it is simple and preferable to control the glass transition temperature [Tg (° C.)] of the binder resin by the kind and ratio of the monomer constituting the styrene acrylic resin which is the main component of the binder resin. A method for measuring Tms (° C.) and Tg (° C.) will be described later.

In the present invention, in the molecular weight distribution in terms of polystyrene by gel permeation chromatography (GPC) of the crystalline resin, the weight average molecular weight [Mw] is preferably 5000 or more and 50000 or less. By setting it in the above range, it is possible to sufficiently maintain the phase separation state with the binder resin. In addition, since the crystallinity of the crystalline resin itself can be increased, more excellent low-temperature fixability and heat resistance can be obtained. When [Mw] is less than 5000, the binder resin and the crystalline resin are easily compatible with each other, so that it is difficult to maintain a structure having a clear boundary. When [Mw] is larger than 50000, the viscosity is hardly lowered even when the crystalline resin is melted, so that the effect on the low-temperature fixability is reduced, or the improvement of the degree of crystallinity by heating and holding is delayed. . The [Mw] is more preferably 7000 or more and 30000 or less. The weight average molecular weight [Mw] of the crystalline resin can be easily controlled by various known production conditions for the crystalline resin.
Further, in a molecular weight distribution in terms of polystyrene by gel permeation chromatography (GPC) of a binder resin containing styrene acrylic resin as a main component, a maximum value [hereinafter also referred to as peak molecular weight (Mp)] of 5000 or more and 40000 or less. It is preferable to have it. By having [Mp] in the above range, the structure control becomes easier while maintaining the phase separation state of the binder resin and the crystalline resin. Further, the toner has better low-temperature fixability and developability. The [Mp] is more preferably 6000 or more and 30000 or less.
The [Mp] can be easily adjusted mainly under known production conditions for the binder resin. Specifically, it can be controlled by a polymerizable monomer, a crosslinking agent, a chain transfer agent, an initiator used for the binder resin, and a polymerization temperature at the time of producing the binder resin. A method for measuring [Mw] of the crystalline resin and [Mp] of the binder resin will be described later.
In the present invention, the content of the crystalline resin is preferably 5.0 parts by mass or more and 40.0 parts by mass or less, more preferably 10.0 parts by mass or more with respect to 100 parts by mass of the binder resin. 30.0 parts by mass or less.

In the present invention, the difference in solubility parameter [SP value] between the binder resin and the crystalline resin, ΔSP value, is preferably 1.0 or less. The SP value is a value for evaluating the cohesive force between polymers, and means that the closer the SP value is to a resin or solvent, the easier it is to mix. In the present invention, the dispersion state of the crystalline resin in the toner particles can be controlled by the ΔSP value. When the ΔSP value is 1.0 or less, the crystalline resin is easily dispersed in the binder resin, and can be present in the toner particles in a finely dispersed state. In this case, since the area of the interface between the binder resin and the crystalline resin is increased, excellent low-temperature fixability is exhibited especially when the speed of the fixing process is increased.
The SP value of the crystalline resin can be controlled by physical properties such as constituent monomers and molecular weight. The SP value can be calculated by the Fedor method. Specifically, for example, it is described in detail in Polymer Engineering and Science, Vol. 14, pages 147 to 154, and the SP value can be calculated by the following formula.
Formula: SP value = √ (Ev / v) = √ (ΣΔei / ΣΔvi)
(Where, Ev: evaporation energy (cal / mol), v: molar volume (cm ³ / mol),
Δei: evaporation energy of each atom or atomic group, Δvi: molar volume of each atom or atomic group)

In the present invention, the crystalline resin is preferably present in the toner in a state where the endothermic retention rate is 70% or more. The endothermic retention rate is a ratio in which the crystalline resin in the toner particles maintains the endothermic amount of the crystalline resin alone, and the higher the retention rate, the higher the crystallinity of the crystalline resin in the toner. I think it exists in the particles. An endothermic retention rate of 70% or more means that the crystallinity of the crystalline resin is sufficiently improved by the toner particle production method of the present invention. Therefore, excellent fixability can be obtained while maintaining the heat resistant storage stability and durability of the toner. In the present invention, the endothermic retention rate is more preferably maintained at 80% or more, and more preferably 90% or more.
The endothermic retention rate of the crystalline resin in the toner can be controlled by the acid value of the crystalline resin, the molecular weight, and the production conditions of the toner particles, but considering the influence on various performances, the production conditions of the toner particles It is preferable and easy to control by. A method for measuring the heat absorption rate retention of the crystalline resin in the toner particles will be described later.

The toner particles produced by the method of the present invention preferably have a weight average particle size [D4] of 5.0 μm or more and 9.0 μm or less, and the ratio [D4] of the D4 to the number average particle size [D1]. / D1] is preferably 1.30 or less. By being in the above range, it is possible to obtain the strength as the toner particles while controlling the crystalline resin in the toner particles to a desired state, and even when a large amount of the crystalline resin is added, the toner is crushed. It is difficult and durability is not easily lowered.
The [D4] is more preferably 5.5 μm or more and 8.0 μm or less. Further, when [D4 / D1] exceeds 1.30, there is a possibility that the crystalline resin not included in the toner particles may form particles alone, and the durability of the toner particles as a whole decreases. There is a case.
[D4 / D1] is an index indicating the degree of particle size distribution, and is 1.00 in the case of complete monodispersion. The larger [D4 / D1] is greater than 1.00, the wider the particle size distribution.
[D4] and [D4 / D1] of the toner particles described above are the materials such as the type and amount of the polymerizable monomer used in the toner particles, the temperature at which the toner particles are produced, and the amount of the dispersion stabilizer. It can be controlled by known manufacturing conditions. Furthermore, in the present invention, as described above, some physical properties and addition amount of the crystalline resin may affect the present invention. A method for measuring [D4] and [D4 / D1] of the toner particles will be described later.

Next, the method for producing toner particles of the present invention will be specifically described with reference to procedures and materials that can be used. However, the method is not limited to the following.
The toner particles of the present invention are produced by producing resin particles using a suspension polymerization method or a dissolution suspension method and then heating and holding the resin particles in an aqueous medium at a specific temperature range for a specific time.
First, a specific method for producing resin particles using the suspension polymerization method will be described.
Add a polymerizable monomer, a colorant and a crystalline resin that form a binder resin for toner particles, and then uniformly dissolve or disperse them using a disperser such as a homogenizer, ball mill, colloid mill, or ultrasonic disperser. A polymerizable monomer composition is prepared. At this time, in the polymerizable monomer composition, a release agent, a polyfunctional monomer, a chain transfer agent, a charge control agent, a plasticizer, and other additives (for example, a pigment) A dispersant or a release agent dispersant) can be appropriately added.
Next, the polymerizable monomer composition is put into an aqueous medium containing a dispersion stabilizer prepared in advance, and suspended using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser. Granulate.
The polymerization initiator may be mixed with other additives when preparing the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition just before being suspended in the aqueous medium. Good. Moreover, it can also be added in the state melt | dissolved in the polymerizable monomer or other solvent as needed during granulation or after granulation completion, ie, just before starting a polymerization reaction.
The suspension after granulation is heated, and the polymerization reaction is carried out with stirring so that the particles of the polymerizable monomer composition in the suspension maintain the particle state and the particles do not float or settle. By performing and completing, an aqueous dispersion of resin particles is formed. At this time, the temperature of the suspension after granulation may improve the low-temperature fixability by maintaining a temperature equal to or higher than the melting point of the crystalline resin until the end of the polymerization.
Next, a specific method for producing resin particles using the dissolution suspension method will be described.
Add binder resin, colorant, and crystalline resin, which are the main constituent materials of toner particles, to organic solvent, and uniformly dissolve or disperse them using a disperser such as a homogenizer, ball mill, colloid mill, or ultrasonic disperser. Prepare a resin solution. At this time, an additive such as a wax as a mold release agent, a charge control agent, and a dispersant can be appropriately added to the resin solution as necessary.
Next, the resin solution is put into an aqueous medium containing a dispersion stabilizer prepared in advance, suspended using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser, and dissolved resin droplets Is formed. There is no restriction | limiting in particular as a stirring apparatus which has a rotary blade, If it is a general thing as an emulsifier and a disperser, it can be used.
In order to remove the organic solvent from the thus obtained dissolved resin droplets, it is possible to employ a method of gradually elevating the temperature of the entire system and completely evaporating and removing the organic solvent in the dissolved resin droplets. . The organic solvent is removed from the dissolved resin droplets as described above to form an aqueous dispersion of resin particles.
The aqueous dispersion of the resin particles formed in the above-described method is used in the aqueous medium at a temperature not lower than the intermediate glass transition temperature of the binder resin and not higher than the melting start temperature of the crystalline resin for 0.5 hour or longer. Keep heated. At this time, if necessary, a dispersion stabilizer such as a surfactant or inorganic fine particles may be added. Thereafter, the toner particles can be obtained by washing as necessary and drying and classifying by various methods.

In the present invention, the binder resin contains a styrene acrylic resin as a main component. Here, “having a styrene acrylic resin as a main component” means that 50% by mass or more of the binder resin is a styrene acrylic resin. In the present invention, the binder resin is preferably a styrene acrylic resin, but in this case, a binder resin used in a conventionally known toner may be included within a range not impairing the effects of the present invention. .
As the styrene acrylic resin, a polymer obtained by polymerizing a known radical polymerizable monomer can be used. Moreover, if it is the radically polymerizable monomer shown below, a part may be modified | denatured. Specific examples of the radical polymerizable monomer include the following.
Styrene such as styrene and α-methylstyrene and derivatives thereof; vinyl esters such as vinyl acetate; methyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, dodecyl (meth) acrylate, ( (Meth) acrylic acid esters such as 2-ethylhexyl methacrylate; vinyl ethers such as vinyl methyl ether; unsaturated dibasic acids such as maleic acid or anhydrides thereof.
In the styrene acrylic resin, a small amount of a polyfunctional monomer can be used in combination for the purpose of improving high temperature offset resistance. The high temperature offset is a phenomenon in which a part of the toner melted at the time of fixing adheres to the surface of a fixing heat roller or a fixing film, which contaminates the subsequent fixing material. As the polyfunctional monomer, a compound having two or more polymerizable double bonds is mainly used, and examples thereof include the following. Aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; A compound having a vinyl group.
These polyfunctional monomers are not necessarily used, but the preferred addition amount when used is 0.01 parts by mass or more and 1.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. is there.

The crystalline resin in the present invention is not particularly limited as long as it has a desired melting start temperature, but crystalline polyester is preferred for the reasons described above. In the present invention, among organic compounds having a crystal structure, those having a weight average molecular weight [Mw] of 3000 or more and having one or more melting points are defined as crystalline resins.
When the crystalline resin is a crystalline polyester, it can be obtained by the reaction of a divalent or higher polyvalent carboxylic acid and a diol. Among these, a polyester mainly composed of an aliphatic diol and an aliphatic dicarboxylic acid is preferable because of high crystallinity.
As the alcohol monomer for obtaining such a crystalline polyester, a known alcohol monomer can be used. Specifically, for example, the following can be used. Alcohol monomers such as ethylene glycol, diethylene glycol and 1,2-propylene glycol; dihydric alcohols such as polyoxyethylenated bisphenol A; aromatic alcohols such as 1,3,5-trihydroxymethylbenzene, pentaerythritol A trivalent alcohol such as
On the other hand, a known carboxylic acid monomer can be used as the carboxylic acid monomer for obtaining the crystalline polyester. Specifically, for example, the following can be used. Dicarboxylic acids such as oxalic acid and sebacic acid and anhydrides or lower alkyl esters of these acids; trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, pyromellitic acid, 1 , 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, trivalent or higher polyvalent carboxylic acid components such as 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, and acids thereof Derivatives such as anhydrides or lower alkyl esters.
The crystalline polyester can be produced by a known polyester synthesis method. For example, after a dicarboxylic acid component and a dial alcohol component are esterified or transesterified, they are subjected to a polycondensation reaction under reduced pressure or by introducing nitrogen gas according to a conventional method to obtain a crystalline polyester.
In the esterification or transesterification reaction, a usual esterification catalyst or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate, and tetrabutyl titanate can be used as necessary. For polymerization, conventional polymerization catalysts such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, and germanium oxide can be used. The polymerization temperature and the amount of catalyst are not particularly limited, and may be arbitrarily selected as necessary.
Moreover, the acid value of crystalline polyester can also be controlled by sealing the carboxyl group of a polymer terminal.
Monocarboxylic acid and monoalcohol can be used for end-capping. Examples of monocarboxylic acids include benzoic acid, naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, And monocarboxylic acids such as stearic acid. As the monoalcohol, methanol, ethanol, propanol, isopropanol, butanol, and higher alcohol can be used.

There is no restriction | limiting in particular as a mold release agent which can be used for this invention, A well-known thing can be utilized. For example, the following compounds are mentioned. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; Waxes mainly composed of fatty acid esters such as waxes, sazol waxes, ester waxes, and montanic acid ester waxes; those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax; aliphatic hydrocarbon waxes Waxes grafted with vinyl monomers such as styrene and acrylic acid; partially esterified products of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; obtained by hydrogenation of vegetable oils and the like And methyl ester compounds having a Dorokishiru group.

The toner particles of the present invention may use a charge control agent. Examples of the charge control agent for controlling the toner particles to be negatively charged include the following.
Organometallic compound, chelate compound, monoazo metal compound, acetylacetone metal compound, urea derivative, metal-containing salicylic acid compound, metal-containing naphthoic acid compound, quaternary ammonium salt, calixarene, silicon compound, nonmetal carboxylic acid compound and derivatives thereof Is mentioned. A sulfonic acid resin having a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group can be preferably used.
The charge control agent is contained in an amount of 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the binder resin in the toner particles. In view of the low-temperature fixability of the toner.

The toner of the present invention contains a colorant. Known colorants such as various dyes and pigments known in the art can be used. As the black colorant, carbon black, a magnetic material, or a color toned to black using the yellow, magenta, and cyan colorants described below is used. As the colorant for cyan toner, magenta toner, and yellow toner, for example, the following colorants can be used.
As the yellow colorant, compounds represented by monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used as pigments. Specifically, C.I. I. Pigment yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, 185.
As the magenta colorant, monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. Pigment Bio Red 19 can be exemplified.
As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds can be used. Specifically, C.I. I. Pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.
These colorants can be used alone or in combination, and further in the form of a solid solution. When a magnetic material is used as the black colorant, the amount added is preferably 40 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the binder resin. When carbon black is used as the black colorant, the amount added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. In the case of a color toner, it is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner, and the preferred addition amount is 1 with respect to 100 parts by mass of the binder resin. It is not less than 20 parts by mass.

Further, the toner particles of the present invention contain a magnetic material and can be used as a magnetic toner. In this case, the magnetic material can also serve as a colorant. In the present invention, examples of the magnetic material include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel. Or alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof. .

Below, the measuring method used by this invention is demonstrated.
<Method for measuring acid value of crystalline resin>
The acid value of the crystalline resin is measured according to JIS K1557-1970. A specific measurement method is shown below. 2 g of the pulverized sample is precisely weighed (W (g)). A sample is put into a 200 ml Erlenmeyer flask, and 100 ml of a mixed solution of toluene and ethanol (2: 1) is added and dissolved for 5 hours. Add phenolphthalein solution as indicator. The solution is titrated with a burette using a 0.1 N KOH alcohol solution. The amount of the alcohol solution of KOH at this time is S (ml). On the other hand, a blank test is performed, and the amount of the alcohol solution of KOH at this time is B (ml).
The acid value is calculated by the following formula.
Acid value = [(SB) × f × 5.61] / W
(F: Factor of alcohol solution of KOH)

<Method for observing crystalline resin in toner particles>
As a method for observing the crystalline resin in the toner particles, first, the toner particles are sufficiently dispersed in a room temperature curable epoxy resin and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. The obtained cured product is cut using a microtome equipped with diamond teeth to produce a flaky sample. After dyeing with ruthenium tetroxide if necessary, the tomographic morphology of the toner is observed using a transmission electron microscope (TEM). In the observation method described above, the amorphous part of the toner particles is strongly dyed by ruthenium tetroxide. As a result, an amorphous part such as a binder resin of toner particles is stained, and an unstained crystalline resin part can be observed as contrast. The observation magnification was 20000 times.

<Measurement of Intermediate Point Glass Transition Temperature [Tg] of Binder Resin, Melting Start Temperature [Tms] of Crystalline Resin, Melting Peak Temperature [Tm], and Endothermic Retention Rate (%) of Crystalline Resin in Toner Particles Method>
The intermediate point glass transition temperature [Tg] of the binder resin, the melting start temperature [Tms] of the crystalline resin, the melting peak temperature [Tm], and the endothermic retention rate (%) of the crystalline resin in the toner particles are different. ASTM using a scanning calorimeter “Q1000” (TA Instruments)
Measured according to D3418-82.
The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
Specifically, 5 mg of resin particles or toner particles or 1 mg of crystalline resin is precisely weighed and placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the measurement range is between 20 ° C. and 140 ° C. Then, the modulation measurement is performed at the setting of the heating rate 1 ° C./min and the amplitude temperature range ± 0.318 ° C./min. In this temperature raising process, a specific heat change is obtained in the temperature range of 20 ° C to 140 ° C.
The glass transition temperature [Tg] at the midpoint of the binder resin is equal to the straight line and the glass transition equidistant from the extended straight line of each baseline before and after the specific heat change of the reversible specific heat change curve. The temperature at the point where the curves of the step-like change part intersect.
The melting start temperature [Tms] of the crystalline resin is a temperature at the intersection of a straight line obtained by extending the low-temperature base line to the high-temperature side and a tangent line drawn at a point where the gradient is maximized on the low-temperature curve of the melting peak. .
The melting peak temperature [Tm] is the temperature at the top of the melting peak of the endothermic curve.
The endothermic amount at the endothermic peak is defined as Q (J / g).
In the present invention, the midpoint glass transition temperature [Tg] of the binder resin when the suspension polymerization method is used is a measured value of the midpoint glass transition temperature of the resin particles produced by the suspension polymerization method.
Further, the heat absorption amount retention ratio (%) of the crystalline resin in the toner particles in the present invention can be obtained from the following formula.
Endothermic retention rate [Cp] (%) = 100 × (Q2 / Q1) × (Cw / 100)
Q1 (J / g): endothermic amount of crystalline resin alone Q2 (J / g): endothermic peak endothermic amount derived from crystalline resin in toner particles Cw (% by weight): crystalline resin at the time of toner particle trial production The amount of crystalline resin in the toner converted from the amount of internal additive. If the endothermic peaks of the crystalline resin and the release agent overlap, the release agent is 100% crystallized in the toner particles. As above, it can be obtained from the above calculation by subtracting the endothermic amount of the release agent.

<Measuring method of weight average molecular weight [Mw] of crystalline resin>
The molecular weight distribution of the crystalline resin is measured by gel permeation chromatography (GPC) as follows.
To o-dichlorobenzene for gel chromatography, special grade 2,6-di-t-butyl-4-methylphenol (BHT) is added so that the concentration becomes 0.10 wt / vol%, and dissolved at room temperature. A crystalline resin and o-dichlorobenzene to which the above-described BHT is added are placed in a sample bottle and heated on a hot plate set at 150 ° C. to dissolve the crystalline resin. Once the crystalline resin has melted, place it in a preheated filter unit and place it on the body. The sample that has passed through the filter unit is used as a GPC sample. The sample solution is adjusted so that the concentration is about 0.15% by mass. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC-8121GPC / HT (manufactured by Tosoh Corporation)
Detector: RI for high temperature
Column: TSKgel GMHHR-H HT 2 series (manufactured by Tosoh Corporation)
Temperature: 135.0 ° C
Solvent: o-dichlorobenzene for gel chromatography
(BHT added at 0.10wt / vol%)
Flow rate: 1.0 ml / min
Injection volume: 0.4ml
In calculating the molecular weight of the crystalline resin, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used. .

<Method for measuring molecular weight distribution of binder resin>
The molecular weight distribution of the binder resin in the present invention is measured by gel permeation chromatography (GPC) as follows. When resin particles were produced using the suspension polymerization method, the molecular weight distribution of the resin particles was defined as the molecular weight distribution of the binder resin.
First, the binder resin or resin particles are dissolved in tetrahydrofuran (THF) over 24 hours at room temperature. Then, the obtained solution is filtered through a solvent-resistant membrane filter “Mysholy disk” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is 0.8% by mass. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml
In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

<Calculation method of weight average particle diameter (D4) and number average particle diameter (D1) of toner particles>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner particles are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.
As the electrolytic aqueous solution used for the measurement, a solution obtained by dissolving special grade sodium chloride in ion-exchanged water so as to have a concentration of 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.
Prior to measurement and analysis, the dedicated software is set as follows.
On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.
In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.
The specific measurement method is as follows.
(1) In a glass 250 ml round bottom beaker for exclusive use of Multisizer 3, 200 ml of the electrolytic aqueous solution is placed and set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) Put 30 ml of the aqueous electrolytic solution into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (manufactured by Nikka Ki Bios) having an electrical output of 120 W is prepared. Into the water tank of the ultrasonic disperser, 3.3 l of ion-exchanged water is added, and 2 ml of Contaminone N is added to the water tank. (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte aqueous solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, 10 mg of toner particles are added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in a sample stand, the electrolyte solution of (5) in which toner particles are dispersed is dropped using a pipette, and the measurement concentration is adjusted to 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistic (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle size (D4). When the number% is set, the “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

<Measuring method of toner aggregation degree>
The degree of aggregation of the toner was measured as follows.
As the measuring apparatus, a “powder tester” (manufactured by Hosokawa Micron Co., Ltd.) having a vibration table side surface portion connected with a digital display vibrometer “Digivibro MODEL 1332A” (manufactured by Showa Keiki Co., Ltd.) was used. Then, a sieve having a mesh size of 38 μm (400 mesh), a sieve having a mesh size of 75 μm (200 mesh), and a sieve having a mesh size of 150 μm (100 mesh) were stacked in this order on the vibrating table of the powder tester. The measurement was performed as follows in an environment of 23 ° C. and 60% RH.
(1) The vibration width of the vibration table was adjusted in advance so that the displacement value of the digital display vibrometer was 0.60 mm (peak-to-peak).
(2) 5 g of toner that had been allowed to stand for 24 hours in an environment of 23 ° C. and 60% RH was precisely weighed and gently placed on a sieve having an opening of 150 μm.
(3) After vibrating the sieve for 15 seconds, the mass of the toner remaining on each sieve was measured, and the degree of aggregation was calculated based on the following equation.
Aggregation degree (%) = {(sample mass (g) on a sieve having an opening of 150 μm) / 5 (g)} × 100
+ {(Sample mass on a sieve having an opening of 75 μm (g)) / 5 (g)} × 100 × 0.6
+ {(Sample mass (g) on a sieve having an opening of 38 μm) / 5 (g)} × 100 × 0.2

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all the parts and% of an Example and a comparative example are mass references | standards unless there is particular notice.

<Synthesis Example 1: Production of crystalline resin 1>
In a reactor equipped with a stirrer, a thermometer, and an effluent cooler, 90.0 parts (31.8 mol%) of sebacic acid, 210.0 parts (68.2 mol%) of 1,9-nonanediol, tetrabutyl 0.2 parts of titanate was added, and the reaction was performed at 160 ° C. for 5 hours. Thereafter, the temperature was raised to 200 ° C. and the pressure inside the system was gradually reduced, and the reaction was carried out under reduced pressure for 5 hours. Then, after returning to normal pressure conditions, the acid adjustment component shown in Table 1 was added (there was no addition in Synthesis Example 1), and the reaction was performed at 200 ° C. for 2 hours to obtain a crystalline resin 1.
<Synthesis Examples 2 to 13: Production of crystalline resins 2 to 13>
In Synthetic Example 1, the reaction was performed in the same manner as in Synthetic Example 1 except that the amount of monomer charged and the reaction time under reduced pressure were changed as shown in Table 1 to obtain crystalline resins 2 to 13 It was.
The physical properties of the obtained crystalline resins 1 to 13 are summarized in Table 2.

<Synthesis Example 14: Production Example of Binder Resin 1>
The following materials were put in a reaction vessel equipped with a reflux condenser, a stirrer, and a nitrogen inlet tube under a nitrogen atmosphere.
・ Toluene 100.0 parts ・ Styrene 75.0 parts ・ N-butyl acrylate 25.0 parts ・ Methyl methacrylate 3.5 parts ・ Methacrylic acid 2.0 parts ・ Acrylic acid 1.5 parts ・ t-butyl peroxypivalate 3.0 parts The inside of the container was stirred at 200 rpm, heated to 70 ° C. and stirred for 10 hours. Furthermore, it heated at 100 degreeC and superposed | polymerized for 6 hours. The solvent was distilled off to obtain a binder resin 1. The binder resin 1 had a peak molecular weight (Mp) of 18000, a glass transition temperature of 53 ° C., and an acid value of 22.3 mgKOH / g.

<Synthesis Example 15: Production Example of Binder Resin 2>
The following raw materials were put in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introducing tube, reacted at 260 ° C. under normal pressure for 8 hours, cooled to 240 ° C., and reduced in pressure to 1 mmHg over 1 hour. The reaction was further continued for 3 hours to obtain a binder resin 2 (amorphous polyester).
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (BPA-PO) 40.0 parts Polyoxypropylene (2.2) -2,2-bis (4-hydroxy Phenyl) ethane (BPA-EO) 340.0 parts, terephthalic acid 140.0 parts, trimellitic acid 10.0 parts, tetrabutyl titanate 1.0 part The binder resin 2 has a peak molecular weight Mp8000 and a glass transition temperature. The acid value was 53 ° C. and 20.6 mg KOH / g.

<Example 1>
(Preparation of toner particles 1)
Styrene 75.0 parts n-butyl acrylate 25.0 parts Pigment blue 15: 3 6.0 parts Aluminum salicylate compound 1.0 part (Bontron E-88 manufactured by Orient Chemical Co., Ltd.)
-Divinylbenzene 0.02 part-Release agent Paraffin wax 9.0 parts (HNP-5: Nippon Seiki, melting point 60 ° C)
-Crystalline resin 1 A monomer mixture consisting of 10.0 parts was prepared. A 15 mm ceramic bead was put in this, and it disperse | distributed for 2 hours using the attritor (made by Mitsui Miike Chemical Industries), and the polymerizable monomer composition was obtained.
To a container equipped with a high-speed stirring device TK-homomixer (made by Tokushu Kika Kogyo Co., Ltd.), 800 parts of ion-exchanged water and 15.5 parts of tricalcium phosphate are added, and the number of revolutions is adjusted to 15000 rpm, 70 The dispersion medium system was obtained by heating to ° C.
4.0 parts of t-butyl peroxypivalate as a polymerization initiator was added to the polymerizable monomer composition, and this was put into the dispersion medium system. The granulation step was performed for 3 minutes while maintaining 15000 rotations / minute with the high-speed stirring device. Thereafter, the stirrer was changed from the high-speed stirrer to the propeller stirring blade, and polymerization was carried out for 8.0 hours while maintaining 70 ° C. while stirring at 150 rpm.
After completion of the polymerization reaction, the temperature of the dispersion was cooled to 20 ° C. while stirring was continued, and a part of the dispersion was extracted. The extracted dispersion was washed and dried, and the midpoint glass transition temperature of the obtained resin particles was measured.
The dispersion was reheated to 65 ° C., which is 5 ° C. lower than the melting start temperature of the crystalline resin 1, and held for 2.0 hours. Thereafter, the temperature of the dispersion was cooled to 20 ° C. while stirring was continued, and hydrochloric acid was added to adjust the pH of the dispersion to 1.5. The mixture was stirred as it was for 2 hours, and filtration and washing with water were repeated three times. Then, the solid content was collected by filtration, and dried in a vacuum dryer at 40 ° C. for 1 day to obtain toner particles 1.

<Examples 3 to 9, Examples 11 to 16, and Comparative Examples 4 to 5>
In Example 1, the crystalline resin used and the heating and holding conditions after completion of the polymerization were changed as shown in Table 3. Other than that, in the same manner as in Example 1, the midpoint glass transition temperature [Tg (° C.)] of the resin particles before heating and holding was measured, and then heated and held, so that the toner particles 3 to 9, 11 to 16, 20 to 21 were obtained.
<Comparative Example 3>
In Example 1, the crystalline resin used was changed to the crystalline resin 13. Further, after the completion of the polymerization reaction, the temperature was cooled to 20 ° C., and hydrochloric acid was added to adjust the pH of the dispersion to 1.5. The mixture was stirred as it was for 2 hours, and filtration and washing with water were repeated three times, and then the solid content was collected by filtration. The solid was dried with a vacuum dryer at 40 ° C. for 1 day to obtain resin particles. Thereafter, the resin particles were heated to 53 ° C., which is 15 ° C. lower than the melting start temperature of the crystalline resin 13, held for 1.0 hour, and cooled to obtain toner particles 19.

<Example 2>
-Binder resin 1 100.0 parts-Crystalline resin 1 10.0 parts-Release agent Paraffin wax 9.0 parts (HNP-5: Nippon Seiki, melting point 60 ° C)
Pigment Blue 15: 3 6.0 parts Aluminum salicylate compound 1.0 part (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
-Ethyl acetate 200.0 parts The above components were mixed and dispersed in a ball mill for 10 hours, and the resulting dispersion was added to 2000 parts of ion-exchanged water containing 3.5% by mass of tricalcium phosphate, and a high-speed stirring device TK. -Granulation was performed with a homomixer at a rotational speed of 15000 rpm for 10 minutes. Thereafter, the mixture was kept at 75 ° C. for 4 hours in a water bath while stirring at 150 rpm with a three-one motor to remove the solvent.
Thereafter, the temperature of the dispersion was cooled to 20 ° C. while stirring was continued.
The dispersion was reheated to 65 ° C., which is 5 ° C. lower than the melting start temperature of the crystalline resin 1, and held for 2.0 hours. Thereafter, the temperature of the dispersion was cooled to 20 ° C. while stirring was continued, and hydrochloric acid was added to adjust the pH of the dispersion to 1.5. The mixture was stirred as it was for 2 hours, and filtration and washing with water were repeated three times. Then, the solid content was collected by filtration, and dried for one day in a vacuum dryer at 40 ° C. to obtain toner particles 2.

<Example 10, Comparative Example 1>
In Example 2, the binder resin used, the crystalline resin, and the heating and holding conditions after completion of the solvent removal were changed as shown in Table 3. Other than that was carried out similarly to Example 2, and the toner particles 10 and 17 were obtained.

<Comparative example 2>
-Binder resin 1 100.0 parts-Crystalline resin 13 10.0 parts-Release agent Paraffin wax 9.0 parts (HNP-51: Nippon Seiki, melting point 74 ° C)
Pigment Blue 15: 3 6.0 parts Aluminum salicylate compound 1.0 part (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
The mixture was premixed with a Henschel mixer, melt-kneaded with a biaxial extruder heated to 90 ° C., and the cooled kneaded product was coarsely pulverized with a hammer mill to obtain a coarsely pulverized product.
The obtained coarsely pulverized product was finely pulverized with a jet mill, and then the obtained pulverized product was subjected to air classification to obtain resin particles.
The resin particles are charged into 2000 parts of ion-exchanged water containing 0.1% by mass of sodium dodecyl sulfate and 3.5% by mass of tricalcium phosphate, and the rotational speed is 3000 rpm with a high-speed stirring device TK-homomixer. The mixture was stirred for 5 minutes to obtain a dispersion of resin particles. While stirring the dispersion, it was reheated to 63 ° C., which is 5 ° C. lower than the melting start temperature [Tms (° C.)] of the crystalline resin 13, and held for 2.0 hours. Thereafter, the temperature of the dispersion was cooled to 20 ° C. while stirring was continued, and hydrochloric acid was added to adjust the pH of the dispersion to 1.5. The mixture was stirred as it was for 2 hours, and filtration and washing with water were repeated three times. Then, the solid content was collected by filtration, and this was dried with a vacuum dryer at 40 ° C. for 1 day to obtain toner particles 18.

<Comparative Example 6>
(Preparation of binder resin dispersion)
-Styrene 285.0 parts-Butyl acrylate 95.0 parts-Acrylic acid 8.0 parts-Dodecyl mercaptan 4.0 parts The said component was mixed beforehand and melt | dissolved and the solution (a) was prepared. On the other hand, 7 parts of nonionic surfactant (trade name: Novonil, Sanyo Kasei Co., Ltd.) and 10 parts of anionic surfactant (trade name: Neogen R, Daiichi Kogyo Seiyaku Co., Ltd.) are added to 520 parts of ion-exchanged water. Dissolved to prepare solution (b).
The solutions (a) and (b) were put into a flask, emulsified by dispersing, and slowly mixed for 10 minutes. Further, 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate was dissolved was added to perform nitrogen substitution. Thereafter, while stirring the flask, the contents were heated in an oil bath until the content reached 90 ° C., and emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature to obtain a binder resin dispersion.
A part of the binder resin dispersion was extracted, washed and dried, and the midpoint glass transition temperature Tg (° C.) of the obtained binder resin was measured and found to be 55 ° C.
(Preparation of colorant dispersion)
-Pigment Blue 15: 3 70.0 parts-Anionic surfactant (trade name: Neogen, manufactured by Daiichi Kogyo Co., Ltd.) 3.0 parts-Ion-exchanged water 400.0 parts After mixing and dissolving the above components, It was dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) to obtain a colorant dispersion.
(Preparation of release agent dispersion)
Paraffin wax (HNP-51: Nippon Seiki, melting point 74 ° C.) 100.0 parts Anionic surfactant (trade name: Pionin A-45-D, Takemoto Yushi Co., Ltd.) 2.0 parts Ion-exchanged water 500 0.0 parts After mixing and dissolving the above components, the mixture was dispersed using a homogenizer (IKA, Ultra Tarrax), then dispersed with a pressure discharge homogenizer, and release agent fine particles (paraffin wax) were dispersed. A release agent dispersion obtained by dispersing was obtained.
(Preparation of crystalline resin 13 dispersion)
Crystalline polyester 13: 200 parts in 800 parts of distilled water, heated to 70 ° C., adjusted to pH 9.0 with ammonia, anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) ) 0.4 parts (as an active ingredient) was added, and the mixture was dispersed at 8000 rpm for 7 minutes with a homogenizer (manufactured by IKA Japan, Ultratarax T50) while heating to 70 ° C. to obtain a crystalline resin 13 dispersion. .
(Production example of resin particles)
-Binder resin dispersion 300.0 parts-Colorant dispersion 50.0 parts-Release agent dispersion 60.0 parts-Crystalline resin 13 dispersion 60.0 parts-Cationic surfactant (trade name: Sanisol B50, manufactured by Kao Corporation) 3.0 parts, ion-exchanged water 500.0 parts The above ingredients were mixed and dispersed in a round bottom stainless steel flask using a homogenizer (trade name: Ultra Turrax T50, manufactured by IKA). After preparing the mixed solution, the mixture was heated to 50 ° C. with stirring in an oil bath for heating, and held at 50 ° C. for 30 minutes to form aggregated particles. Next, 6 parts of sodium dodecylbenzenesulfonate (trade name: Neogen SC, manufactured by Daiichi Kogyo Co., Ltd.) as an anionic surfactant was added to the aggregated particle dispersion and heated to 55 ° C. Further, sodium hydroxide was appropriately added to keep the pH in the system at 4.0 or lower, and maintained for 3 hours to fuse the aggregated particles. Thereafter, the aggregated particle dispersion was cooled to 20 ° C.
Thereafter, while stirring the dispersion, it was reheated to 63 ° C., which is 5 ° C. lower than the melting start temperature [Tms (° C.)] of the crystalline resin 13, and held for 2.0 hours. Thereafter, the temperature of the dispersion was cooled to 20 ° C. while continuing the stirring, filtered, sufficiently washed with ion-exchanged water, and dried with a vacuum dryer to obtain toner particles 22.

<Production of each toner>
100 parts of silica fine powder is treated with 10 parts of hexamethyldisilazane and further treated with 10 parts of silicone oil to form a hydrophobic silica fine powder having an average primary particle diameter of 12 nm and a BET specific surface area of 120 m ² / g. The body was prepared. Next, after the toner particles 1 to 22 are classified, 100.0 parts of each are weighed, 1.0 part of each hydrophobic silica fine powder is added, and mixed using a Henschel mixer (manufactured by Mitsui Miike Chemical). Toners 1 to 22 were obtained.
Table 3 summarizes the production steps of the toner particles obtained in Examples 1 to 16 and Comparative Examples 1 to 6. Table 4 summarizes the results of measuring the physical properties of the toner particles using the above-described method for each toner particle.

The performance of each toner obtained in Examples 1 to 16 and Comparative Examples 1 to 6 was evaluated according to the following method.
<Evaluation of fixability>
Using a commercially available color laser printer (LBP-5400, manufactured by Canon Inc.), the toner in the cyan cartridge was taken out and filled with the toner, and the cartridge was mounted on the cyan station. Next, an unfixed toner image (toner applied amount: 0.6 mg / cm ² ) of 2.0 cm in length and 15.0 cm in width is passed on an image receiving paper (an office planner 64 g / m ² manufactured by Canon Inc.). It formed in the part of 1.0 cm from the upper end part with respect to the direction. Next, the fixing unit removed from a commercially available color laser printer (LBP-5400, manufactured by Canon Inc.) was remodeled so that the fixing temperature and process speed could be adjusted, and a fixing test of an unfixed image was performed using this. .
First, under normal temperature and humidity, the process speed is set to 200 mm / s, the fixing linear pressure is set to 28.0 kgf, the initial temperature is set to 110 ° C., and the set temperature is sequentially increased by 5 ° C. Fix it.
In the present invention, the low-temperature fixability indicates that the low-temperature offset is not observed and the obtained fixed image is rubbed before and after rubbing with sylbon paper applied with a load of 4.9 kPa (50 g / cm ² ). The temperature at which the density reduction rate of the toner was 10% or less was defined as the low temperature side fixing start point. The evaluation criteria for the low-temperature fixing performance are as follows.
A: The low temperature side fixing start point is 120 ° C. (low temperature fixing performance is particularly excellent)
B: Low temperature side fixing start point is 125 ° C. (low temperature fixing performance is good)
C: Low temperature side fixing start point is 130 ° C.
D: low temperature side fixing start point is 135 ° C. (low temperature fixing performance is slightly inferior)
E: Low temperature side fixing start point is 140 ° C. (low temperature fixing performance is inferior)

Regarding toners 9 to 22, the fixability under low pressure conditions was evaluated by the following method. Under normal temperature and humidity, the initial process speed is 100 mm / s, the fixing linear pressure is 28.0 kgf, and the set fixing linear pressure is successively decreased by 4.0 kgf, and the unfixed image is fixed at each fixing linear pressure. The set temperature was the low temperature fixing start point of each toner in the above test. When the low-temperature offset was not observed and the obtained fixed image was rubbed with sylbon paper applied with a load of 4.9 kPa (50 g / cm ² ), the density reduction rate before and after rubbing was 10% or less. The fixing linear pressure obtained was set as a fixing linear pressure capable of fixing. The evaluation criteria for fixability under low pressure conditions are as follows.
A: The fixing linear pressure capable of fixing is 12.0 kgf or less (the fixing performance at low pressure is particularly excellent).
B: Fixing linear pressure capable of fixing is 16.0 kgf (fixing performance at low pressure is good)
C: The fixing linear pressure capable of fixing is 20.0 kgf (the fixing performance at a low pressure is not a problem level) D: The fixing linear pressure capable of fixing is 24.0 kgf (the fixing performance at a low pressure is slightly inferior)
E: Fixing linear pressure capable of fixing is 28.0 kgf (fixing performance at low pressure is inferior)

<Evaluation of developability after standing at high temperature>
Each toner was allowed to stand at 50 ° C. for 30 days. Thereafter, for each toner, the degree of aggregation of the toner and the endothermic retention rate (%) of the crystalline resin in the toner were measured according to the method described above. In addition, using a commercially available color laser printer (LBP-5400, manufactured by Canon Inc.), the toner of the cyan cartridge was taken out and filled with 50 g of the toner which was allowed to stand for 30 days in the above-described 50 ° C. environment. The cartridge is mounted on a cyan station of a printer, and a printing rate 2% chart is set to 5000 using image receiving paper (an office planner 64 g / m ² manufactured by Canon Inc.) at room temperature and normal humidity (23 ° C., 60% RH). Images were continuously printed, and the resulting image quality was evaluated as the durability of the toner based on the difficulty of fusing and image streaking due to a decrease in toner fluidity.
A: A vertical streak in the paper discharge direction, which appears as a development streak, is not seen on the developing roller or the halftone image. There is no problem in practical use. (Durability is particularly excellent)
B: Although there are 1 to 5 thin circumferential streaks at both ends of the developing roller, no vertical streak in the paper discharge direction, which appears as a developing streak, is seen on the halftone image. There is no problem in practical use. (Excellent durability)
C: There are several thin circumferential streaks at both ends of the developing roller, and several fine developing streaks can be seen on the halftone image. However, there is no practical problem at the level that can be erased by image processing. (Durability is good)
D: There are five or more fine streaks in the circumferential direction at both ends of the developing roller, and five or more fine development streaks that can be confirmed slightly even when erased by image processing are seen on the halftone image. (Durability is inferior to C)
E: A large number of development streaks are seen on the developing roller and on the halftone image, and cannot be erased even by image processing. (Durability is inferior to D)

<Evaluation of developability in high humidity environment>
For toners 1 to 8 and 17 to 22, development performance in a high humidity environment was evaluated.
The toner was allowed to stand for 1 day in an environment of high humidity (temperature 30 ° C., humidity 80%). Thereafter, with respect to each toner, the above-described evaluation of developability was performed under high humidity (temperature 30 ° C., humidity 80%), thereby evaluating the image quality in a high humidity environment. The results are shown in Table 5.

As described above, the method for improving the crystallinity of the crystalline resin according to the present invention and the structure of the binder resin and the crystalline resin in the toner in which the main component of the binder resin is a styrene acrylic resin and contains the crystalline resin. It has been found that if the control method is used, a toner having excellent fixing performance and developing performance can be obtained. By sufficiently improving the crystallinity while encapsulating the crystalline resin, a toner having excellent developability even in a harsh environment was obtained while maximizing the low-temperature fixing effect of the crystalline resin. In addition, by making it exist in the vicinity of the surface layer while improving the crystallinity of the crystalline resin, an image that adheres to the toner and paper even when the pressure during fixing is lowered while exhibiting excellent development performance, is difficult to peel off I found out that
On the other hand, in the comparative example, when the crystallinity of the crystalline resin is not improved and the structure control of the binder resin and the crystalline resin is not sufficient, the development performance is remarkably inferior. Degradation and fluidity have been reduced.

A method for producing toner particles containing a binder resin , a colorant and a crystalline resin,
I) or ii ) below
i) Polymerizable monomer composition containing a polymerizable monomer, a colorant and a crystalline resin is dispersed in an aqueous medium, granulated, and a polymerizable monomer contained in the granulated particles. it produces a resin particle by polymerizing the body,
ii) A binder resin, a colorant, and a crystalline resin are dissolved or dispersed in an organic solvent to prepare a resin solution, and the resin solution is dispersed in an aqueous medium, granulated, and the granulated particles it produces resin particles to remove the organic solvent contained,
A step of producing resin particles by the above method ; and heating the resin particles in an aqueous medium at a temperature not lower than the glass transition temperature of the binder resin and not higher than the melting start temperature of the crystalline resin for not less than 2.0 hours. Holding step ;
Have
The binder resin is a styrene acrylic resin ,
The crystalline resin is a crystalline polyester;
The present invention relates to a method for producing toner particles, wherein the crystalline resin has a melting start temperature of 50C or more and 72C or less .

For toners 1 to 8 and 17 to 22, development performance in a high humidity environment was evaluated.
The toner was allowed to stand for 1 day in an environment of high humidity (temperature 30 ° C., humidity 80%). Thereafter, with respect to each toner, the above-described evaluation of developability was performed under high humidity (temperature 30 ° C., humidity 80%), thereby evaluating the image quality in a high humidity environment. The results are shown in Table 5.
In addition, Examples 3-4, Examples 6-8, and Examples 14-16 are referred to as Reference Examples 3-4, Reference Examples 6-8, and Reference Examples 14-16, respectively.

Claims (4)

A method for producing toner particles containing a binder resin comprising a styrene acrylic resin as a main component, a colorant and a crystalline resin, wherein the resin particles are produced by the following method i) or ii) A step of heating and holding the particles in an aqueous medium at a temperature not lower than the glass transition temperature of the binder resin and not higher than the melting start temperature of the crystalline resin for not less than 0.5 hours. Production method.
i) Polymerizable monomer composition containing a polymerizable monomer, a colorant and a crystalline resin is dispersed in an aqueous medium, granulated, and a polymerizable monomer contained in the granulated particles. The particles are polymerized to produce resin particles.
ii) A binder resin, a colorant, and a crystalline resin are dissolved or dispersed in an organic solvent to prepare a resin solution, and the resin solution is dispersed in an aqueous medium, granulated, and the granulated particles Resin particles are produced by removing the contained organic solvent.   The method for producing toner particles according to claim 1, wherein the crystalline resin is crystalline polyester.   The method for producing toner particles according to claim 1, wherein the acid value of the crystalline resin is 0.1 mgKOH / g or more and 50.0 mgKOH / g or less.   4. The melting start temperature of the crystalline resin is 50 ° C. or higher and 100 ° C. or lower, and the melting start temperature is higher than the midpoint glass transition temperature of the binder resin. 2. A method for producing toner particles according to item 1.