JP5455475B2 - toner - Google Patents

Description

  The present invention relates to a toner used to form 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, printers and copiers have become more and more sophisticated in image quality due to digitization, and at the same time, printing or copying speeds have been increased, space savings and lower power consumption have been demanded by downsizing devices. It has become.

  In order to satisfy the above requirements, improvement of the toner itself is required.

  In other words, from the viewpoint of high image quality, it is required to reduce the toner particle size and sharpen the particle size distribution for the purpose of high resolution and high definition, and spherical toner is desired for the purpose of improving transfer efficiency and fluidity. It is supposed to be.

  On the other hand, from the viewpoint of high speed and low power consumption, it is desired to realize a toner that can be fixed at a lower temperature.

  As a general method for improving the low-temperature fixability of the toner, there is a method using a sharp melt material for the binder resin constituting the toner, and it is known that the polyester resin exhibits excellent characteristics in this respect. It has been.

  As a method for easily obtaining a spherical toner having a small particle diameter using a polyester resin, a resin component is dissolved in an organic solvent immiscible with water, and this solution is dispersed in an aqueous medium to obtain oil droplets. There is a “dissolution suspension method” in which toner particles are produced by removing the organic solvent after forming the toner.

  A method for lowering the glass transition temperature of the binder resin is also known as an effective method. However, if the glass transition temperature is simply lowered, the heat-resistant storage stability of the toner is lowered, and when used in a high temperature environment, a so-called blocking phenomenon in which agglomeration occurs between the toners in contact with each other to form a lump is likely to occur. Further, there is a problem that the toner carrying member is easily contaminated and the filming on the photosensitive member is likely to occur, resulting in a deterioration in image quality.

  In order to solve these problems, a capsule structure composed of core particles containing a resin having a low glass transition temperature and an outer shell (coating layer) containing a resin having a high glass transition temperature formed on the surface of the core particles Toners have been devised.

  For example, a reaction component capable of forming a resin is added to the inside and / or the outside of an oil droplet obtained by emulsifying and dispersing an oily liquid of a core material containing a binder resin and a colorant in an aqueous phase, and a polymer reaction Has proposed a toner in which an outer shell of the resin is formed around oil droplets (see Patent Document 1).

  In addition, by dispersing droplet particles containing an organic solvent, a binder resin and a colorant in an aqueous medium containing resin fine particles, and removing the organic solvent from the droplet particles, the surface of the particles is covered with the resin fine particles. A toner having a pseudo capsule structure has been proposed (see Patent Documents 2 and 3).

  In addition, fine particles obtained by soap-free emulsion polymerization of vinyl monomers are adhered and fixed on the surface of core particles obtained by suspension granulation of polyester resin in a wet process using a water-soluble polymerization initiator. Toner is disclosed (see Patent Document 4).

  Further, after emulsifying, suspending or aggregating the toner composition in an aqueous medium to prepare toner particles, a surfactant having a polarity different from the polar group on the surface of the toner particles and organic fine particles are added to add the organic particles. A method of attaching fine particles to the surface of toner particles is disclosed (see Patent Document 5).

  Among the above-described conventional examples, the toner disclosed in Patent Document 1 is a polyurethane in which a polyvalent isocyanate and a polyol or polyamine are added in an aqueous phase or an oil droplet of a core substance to cause a polymer reaction at the oil droplet interface. Alternatively, it forms an outer shell made of polyurea. In the case of core particles having a low glass transition temperature that satisfies low-temperature fixability, it is necessary to increase the thickness of the outer shell in order to obtain sufficient heat-resistant storage stability, but the outer shell thus formed usually exceeds 100 ° C. Since it has a high glass transition temperature, it has a tendency to inhibit low-temperature fixability.

  The toners disclosed in Patent Documents 2 and 3 use resin fine particles having a glass transition temperature of about 50 to 70 ° C., and the coating amount is about 0.3 to 2.0 mass%. It is not intended to cover the entire surface of the core particles. The heat-resistant storage stability depends largely on the effect of network structure formed by urea bonds formed on the surface of the core particles separately from the coating layer made of the resin fine particles. Tended to be inhibited.

  In the toner disclosed in Patent Document 4, the water-soluble polymerization initiator acts on the unreacted monomer in the microparticles, and the microparticles and the core particles are molecularly bonded through a polymerization reaction. It is said that it can be firmly attached. However, when this method was actually tried, it was difficult to uniformly coat the fine particles on the surface of the core particles first, and even though the adhesion strength could be partially increased, the outer surface having a stable strength could be obtained. A shell could not be formed. As a result, it is impossible to obtain a toner having sufficient heat-resistant storage stability, it cannot be said that the durability for long-term use is sufficient, and furthermore, since the toner surface is inferior in smoothness, a stable triboelectric chargeability can be obtained. It was also difficult.

  Further, the toner disclosed in Patent Document 5 neutralizes the charge of the organic fine particle dispersion in water with a surfactant having a reverse polarity, thereby aggregating and adhering the organic fine particles to the surface of the core particle. However, even in this method, the homogeneity of the agglomerated organic fine particles is not always sufficient, and since the adhesion strength is not sufficient, the durability especially in long-term use is insufficient, and the smoothness of the toner surface. Therefore, it was difficult to obtain a stable triboelectric chargeability.

  As described above, capsule toner composed of core particles having a low glass transition temperature and an outer shell having a high glass transition temperature are excellent in both low-temperature fixability and heat-resistant storage stability and stable in durability and frictional charging. At present, toners that have both properties are not yet available. Therefore, the early realization of such toner is expected.

JP 05-297622 A JP 2004-226572 A JP 2004-271919 A Japanese Patent Laid-Open No. 01-257856 JP 2005-024839 A

  An object of the present invention is to provide a toner that solves the above-described conventional problems.

  That is, an object of the present invention is to provide a toner having excellent low-temperature fixability and heat-resistant storage stability, excellent durability in long-term use, and excellent frictional charging stability. .

The present invention includes a core having containing a colorant and a wax and a resin (a) mainly composed of polyester (A),
Intermediate layer mainly composed of resin (b) obtained by covering the core (A) (B), and,
Surface layer (C) mainly composed of resin (c) formed by coating intermediate layer (B)
A toner having toner particles comprising:
The resin (b) is a resin containing a sulfonic acid group and / or a sulfonic acid group,
The sulfonic acid value of the resin (b) is 10.0 mgKOH / g or more and 30.0 mgKOH / g or less,
The pH indicating the isoelectric point determined by measuring the zeta potential of the toner particles in water is P1, and the isoelectric point determined by measuring the zeta potential in water after ultrasonically treating the toner particles in ethyl acetate for 1 minute. The present invention relates to a toner in which P1 and P2 satisfy the following relational expressions (1) and (2) when the indicated pH is P2.
2.0 <P1 <4.0 (1)
P1-P2> 0.3 (2)

  According to the present invention, a toner having excellent low-temperature fixability and heat-resistant storage stability, excellent durability in long-term use, and excellent frictional charging stability can be provided.

It is a figure which shows the calculation method of the water absorption amount by a TGA curve. It is the schematic of the apparatus which measures a triboelectric charge amount.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

  In the toner having capsule-structure toner particles in which a coating layer is provided on the surface of core particles mainly composed of polyester, the inventors pay attention to the polarity of the resin constituting the coating layer, and the outermost surface of the coating layer. The effect of the difference in polarity from the inside on the triboelectric chargeability of the toner was examined.

  The outermost surface of the coating layer has a relatively low polarity, and it has been found that the stability of frictional charging in a long-term use is greatly improved when it is configured such that a portion having a high polarity exists inside the coating layer. It was.

  Toner particles having such a structure can be obtained by providing an intermediate layer (B) on the surface of the core (A) containing polyester resin as a main component and further providing a surface layer (C) on the surface. At this time, a resin having a relatively high polarity is used for the resin (b) constituting the intermediate layer (B), and a resin having a relatively low polarity is used for the resin (c) constituting the surface layer (C). .

  Whether or not the toner particles have the above-described configuration indicates an isoelectric point when the toner particles are subjected to ultrasonic treatment in ethyl acetate and the toner particles before and after the ultrasonic treatment are measured for zeta potential in water. This can be clarified by determining whether there is a change in pH.

  The zeta potential is used as an index representing the state of the surface charge of the particles. Normally, in the case of negatively chargeable toner particles, the zeta potential in water shows a negative value in the pH range near neutrality. Further, the value of the zeta potential tends to approach 0 mV as the pH is lowered, and when the pH is further lowered, it eventually turns to a positive value. The point at which the zeta potential value indicates 0 mV is referred to as an isoelectric point. The higher the polarity of the particle surface, the lower the pH indicating the isoelectric point.

  When the toner particles having the above-described configuration are ultrasonically treated in ethyl acetate, at least part of the resin (c) constituting the surface layer (C) can be removed, and the resin (b) constituting the intermediate layer (B) ) Can be exposed. Therefore, by comparing the pH indicating the isoelectric point before and after the ultrasonic treatment, the difference in polarity between the outermost surface and the inside of the toner particles can be known.

  That is, the pH indicating the isoelectric point after ultrasonic treatment of the toner particles having the above-described configuration is lowered with respect to the pH indicating the isoelectric point before ultrasonic treatment due to the influence of the exposed resin (b). Show the trend.

  In the present invention, the ultrasonic treatment is specifically performed according to the following procedure.

First, about 30 ml of ethyl acetate is put into a glass 100 ml beaker, and about 1 g of toner particles are put therein.
This beaker is set in a water tank of an ultrasonic disperser “Ultrasonic Dispense System Tetora 150” (manufactured by Nikkaki Bios Co., Ltd.) having an output of 120 W and including two oscillators with an oscillation frequency of 50 kHz.

  And the position of a beaker is adjusted so that the liquid level height of the ethyl acetate in a beaker may become substantially equal to the water surface of a water tank, and an ultrasonic dispersing device is operated for 1 minute, and it processes.

  It is important that the ultrasonic treatment be completed in a short time of about 1 minute. If the treatment is performed excessively, even the intermediate layer (B) and the core (A) are affected, and the entire toner particles are damaged. Is unfavorable because it increases.

In the present invention, when the pH indicating the isoelectric point before ultrasonic treatment of the toner particles is P1, and the pH indicating the isoelectric point after ultrasonic treatment is P2, P1 and P2 are expressed by the following relational expression (1 ) And (2) are preferably satisfied.
2.0 <P1 <4.0 (1)
P1-P2> 0.3 (2)

  The above P1 represents the state of polarity on the outermost surface of the toner particles. If the value of P1 is low, the developability may be deteriorated due to the fact that the triboelectric charge amount as the toner becomes too high. If the value of is high, a sufficient triboelectric charge may not be obtained. That is, when the value of P1 is in the range of the relational expression (1), good chargeability as a toner can be obtained.

  On the other hand, since P2 represents the state of polarity inside the toner particles, the fact that the value of (P1−P2) satisfies the above relational expression (2) indicates that the inside of the toner particles is compared with the innermost surface. Means that it has a sufficiently high polarity. Although the detailed mechanism is unknown, stable charging performance can be maintained for a long time without causing the adverse effect of excessively high triboelectric charge due to the presence of a highly polar part inside the toner particles. It is considered a thing.

  The values of P1 and P2 can be adjusted by allowing the resin (b) and the resin (c) to each contain a polar group and changing the type and amount of the polar group.

  Specifically, it is preferable to use a resin containing at least a sulfonic acid group and / or a sulfonic acid group as the resin (b). The sulfonic acid group and the sulfonic acid group have high polarity, and the value of P2 can be effectively controlled by adjusting the sulfonic acid value of the resin (b).

  When the sulfonic acid value of the resin (b) is too low, P2 cannot be controlled to a desired value, and the above effect cannot be obtained. On the other hand, if it is too high, the hygroscopicity when it is made into toner may increase, and the triboelectric chargeability may be impaired. Therefore, the sulfonic acid value of the resin (b) is preferably 10.0 mgKOH / g or more and 30.0 mgKOH / g or less, more preferably 15.0 mgKOH / g or more and 25.0 mgKOH / g or less. .

  The sulfonic acid value as used herein represents the content of the sulfonic acid group in the resin (b), and when the sulfonic acid group is in a salt state, the value when the acid state is restored. Represent as

  On the other hand, it is preferable to use a resin containing at least a carboxylic acid group and / or a carboxylic acid group for the resin (c). The value of P1 can be adjusted by the carboxylic acid value of the resin (c).

  If the carboxylic acid value of the resin (c) is too low, the value of P1 becomes high and a sufficient triboelectric charge amount as a toner cannot be obtained. On the other hand, if it is too high, the hygroscopicity when it is made into toner may increase, and the triboelectric chargeability may be impaired. Therefore, the carboxylic acid value of the resin (c) is preferably 5.0 mgKOH / g or more and 25.0 mgKOH / g or less, more preferably 10.0 mgKOH / g or more and 15.0 mgKOH / g or less. .

  The carboxylic acid value as used herein represents the content of the carboxylic acid group in the resin (c), and when the carboxylic acid group is in a salt state, the value when it is returned to the acid state. Represent as

  The values of P1 and P2 vary depending on the material and composition of each resin in addition to the carboxylic acid value of the resin (c) and the sulfonic acid value of the resin (b).

  Accordingly, when the materials and compositions of the resin (b) and the resin (c) to be used are different, it is preferable to appropriately select a sulfonic acid value or a carboxylic acid value corresponding to each material.

  The resin (c) is particularly preferably a resin having a water absorption of 2.5% by mass or less when left for 1 hour under conditions of a temperature of 40 ° C. and a relative humidity of 95%. By constituting the surface layer (C) with such a resin, it is possible to avoid problems with frictional charging caused by moisture absorption of the toner.

  When the glass transition temperature of the resin (a) as the main constituent material of the core (A) is too high, good low-temperature fixability cannot be obtained, but when it is too low, the glass transition temperature as a toner is lowered. This causes various harmful effects. This is because it becomes difficult to obtain the effect of the surface layer (C) formed of the resin (c). Specifically, the heat-resistant storage stability is lowered, the wrapping of the sheet to be fixed at the time of fixing, and the high temperature offset. It is such an evil. Further, there is a tendency that the stability when the image after fixing is stored at a high temperature is lowered.

  Needless to say, the glass transition temperature of the resin (c) constituting the surface layer (C) needs to be higher than the glass transition temperature of the resin (a) for the purpose of improving the heat resistant storage stability of the toner.

  On the other hand, the glass transition temperature of the resin (b) constituting the intermediate layer (B) is not necessarily higher than the glass transition temperature of the resin (a). In order to prevent damage, it is preferable that the glass transition temperature is equal to the glass transition temperature of the resin (a).

That is, in the present invention, the glass transition temperature of the resin (a) is Tg (a), the glass transition temperature of the resin (b) is Tg (b), and the glass transition temperature of the resin (c) is Tg (c). It is particularly preferable that Tg (a) to Tg (c) satisfy the following relational expressions (3) to (5).
30 <Tg (a) <60 (3)
| Tg (b) −Tg (a) | <20 (4)
20 <Tg (c) −Tg (a) <50 (5)

  By satisfying such a relationship, the core (A) original low-temperature fixability is not significantly impaired, and a sufficient heat-resistant storage stability improving effect can be obtained.

  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 the above-described heat roller or fixing film, which contaminates the subsequent fixing sheet.

  In the present invention, the content of the resin (b) in the toner particles is preferably 3.0% by mass or more and 10.0% by mass or less. Moreover, it is preferable that content of the said resin (c) is 2.0 mass% or more and 10.0 mass% or less. Furthermore, the total content of the resin (b) and the resin (c) is preferably 6.0% by mass or more and 15.0% by mass or less.

  By setting the content of the resin (b), the content of the resin (c), and the total thereof within the above range, it is possible to effectively achieve both low-temperature fixability and heat-resistant storage stability.

  In the present invention, the surface layer (C) is prepared by preparing core particles composed of the core (A) and the intermediate layer (B), and then the resin containing the resin (c) as a main component on the surface of the core particles. It can be formed by fixing the fine particles (c ′).

  As described above, the resin (c) is preferably a resin containing at least a carboxylic acid group and / or a carboxylic acid group, and the resin fine particles (c ′) can be stably self-dispersed in water.

  Specific examples of the method for fixing such resin fine particles (c ′) to the surface of the core particle include the following methods. That is, after adding resin fine particles (c ′) to the aqueous medium in which the core particles are dispersed, acid is added to lower the pH of the aqueous medium to destabilize the dispersibility of the resin fine particles (c ′). It is a method of agglomerating and fixing to the surface of the core particles to be made.

  Here, as described above, the resin (b) constituting the intermediate layer (B) is preferably a resin containing at least a sulfonic acid group and / or a sulfonic acid group, and has a higher polarity than the resin (c). have.

  Therefore, when the pH is lowered in a state where the core particles and the resin fine particles (c ′) coexist in the aqueous medium, the surface charge of the core particles at the stage where the zeta potential of the resin fine particles (c ′) shows 0 mV. Is still in a state of holding a negative charge. Further, when the zeta potential of the core particle is 0 mV, the surface charge of the resin fine particles (c ′) has already been changed to a positive charge.

  That is, in the process in which the resin fine particles (c ′) lose their dispersibility in water, an electrical attractive force acts between the core particles and the resin fine particles (c ′).

  As a result, the resin fine particles (c ′) can be uniformly adhered to the surface of the core particle while suppressing the aggregation of the resin fine particles (c ′) by themselves, and is more uniform and excellent in adhesion. The surface layer (C) can be formed.

  The toner thus obtained can also have an effect of improving durability in long-term use.

  The intermediate layer (B) is formed in the same manner as the surface layer (C) by first producing a core (A), using this as a core particle, and resin fine particles mainly containing the resin (b) on the surface. Although a method of fixing (b ′) may be used, in the present invention, a method using the dissolution suspension method shown below is particularly preferable.

  In the dissolution suspension method, a resin is dissolved in an organic solvent, the resin solution obtained in an aqueous medium containing a dispersion stabilizer is dispersed to form droplets, and then the organic solvent is removed from the droplets. This is a method of obtaining particles having a desired particle size by solidification.

  As described above, since the resin (b) is a resin containing at least a sulfonic acid group and / or a sulfonic acid group, the resin fine particles (b ′) can also be stably self-dispersed in water. It can be used as a suitable dispersion stabilizer during the formation of droplets of the solution.

Specifically, it is formed as follows.
First, a resin composition is prepared by dissolving or dispersing the resin (a) and a colorant or wax in an organic solvent immiscible with water and capable of dissolving the resin (a). At this time, other additives can be added to the resin composition as necessary. Next, the resin composition is dispersed in an aqueous medium in which resin fine particles (b ′) are dispersed to form droplets of the resin composition. And the organic solvent in the said droplet is removed using methods, such as a heating and pressure reduction, and this droplet is solidified. After the resin fine particles (b ′) play a role as a dispersion stabilizer, the resin fine particles (b ′) remain on the formed particles and cover the surfaces of the particles in layers.

  Thus, according to the method using the dissolution suspension method, the formation of the core (A) and the formation of the intermediate layer (B) can be performed simultaneously.

  In the toner of the present invention, the particles composed of the core (A) and the intermediate layer (B) thus obtained are used as core particles, and the surface layer (C) of resin fine particles (c ′) is provided on the surface thereof. This is characterized in that the physical properties of the resin constituting the intermediate layer (B) and the surface layer (C) are respectively defined.

  The difference in the distribution of polar groups between the outermost surface and inside of the toner particles can be obtained from zeta potential measurement when the toner particles are sonicated in ethyl acetate for 1 minute, which has not been considered in the past. It is defined from the viewpoint of change of isoelectric point.

  Therefore, the technology is different from the conventional toner obtained by the conventional encapsulation technology by the dissolution suspension method and the conventional encapsulation technology by fixing the resin fine particles, and these technologies are simply combined. Therefore, it is difficult to achieve the object of the present invention.

  As described above, according to the present invention, a toner having excellent low-temperature fixability and heat-resistant storage stability, excellent durability in long-term use, and excellent frictional charging stability is obtained. It can be realized.

  Hereinafter, the core particles composed of the core (A) and the intermediate layer (B), which are the features of the present invention, will be described in more detail by taking the case of using the dissolution suspension method as an example.

  The resin (a) used for the core (A) contains a polyester resin as a main component. Here, “main component” means that the polyester resin occupies 50% by mass or more based on the total amount of the resin (a).

  As said polyester and resin, what polycondensated the polyhydric alcohol component and the polyhydric carboxylic acid component by the well-known method can be used. Specifically, the following compounds are mentioned. Examples of the divalent alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) Propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4- Alkylene oxide adducts of bisphenol A such as hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl Coal, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogen Examples thereof include added bisphenol A, bisphenol derivatives represented by the following general formula (I), and compounds represented by the following general formula (II).

（式中、Ｒはエチレンまたはプロピレン基であり、ｘおよびｙは夫々１以上の整数であり、且つｘ＋ｙの平均値は２乃至１０である。）

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

（式中、Ｒ’は−ＣＨ₂ＣＨ₂−、−ＣＨ₂ＣＨ（ＣＨ₃）−、または−ＣＨ₂−Ｃ（ＣＨ₃）₂−である。）

(In the formula, R ′ represents —CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) —, or —CH ₂ —C (CH ₃ ) ₂ —).

  Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1 , 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene. .

  The polyvalent carboxylic acid component includes aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; Succinic acid substituted with 6 to 12 alkyl groups or anhydride thereof; Unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydride thereof; n-dodecenyl succinic acid, isododecenyl succinic acid, trimellit Examples include acids.

  Among these, in particular, a bisphenol derivative represented by the general formula (I) and an alkyl diol having 2 to 6 carbon atoms as a diol component, a carboxylic acid composed of a divalent carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof. Acid components (for example, fumaric acid, maleic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, alkyl dicarboxylic acids having 4 to 10 carbon atoms, and acid anhydrides of these compounds) as acid components Polyester resins obtained by condensation polymerization of these are preferred.

  Examples of the method for producing the polyester resin include a synthesis method by oxidation reaction, synthesis from carboxylic acid and its derivatives, ester group introduction reaction represented by Michael addition reaction, dehydration condensation reaction from carboxylic acid compound and alcohol compound. Examples of the method used include a reaction from an acid halide and an alcohol compound, and a transesterification reaction. As the catalyst, a general acidic or alkaline catalyst used in the esterification reaction, for example, zinc acetate or a titanium compound can be used. Thereafter, it may be highly purified by a method such as a recrystallization method or a distillation method.

  In addition to the polyester resin, the resin (a) may contain, for example, a vinyl resin, a hybrid resin having a polyester resin unit and a vinyl resin unit, a mixed resin of polyester and vinyl resin, and an epoxy resin. . In that case, the content of the polyester resin is preferably 50% by mass or more, and more preferably 70% by mass or more based on the total amount of the resin (a).

  The molecular weight of the resin (a) is preferably a peak molecular weight of 8000 or less, and more preferably 5500 or less. Moreover, it is preferable that the ratio of molecular weight 100,000 or more is 5.0% or less, and it is more preferable that it is 1.0% or less. Furthermore, the ratio of the molecular weight of 1000 or less is preferably 10.0% or less, and more preferably 7.0% or less.

  When the peak molecular weight of the resin (a) is 8000 or less and the ratio of the molecular weight of 100,000 or more is 5.0% or less, the resin fine particles used as the dispersion stabilizer and the resin fine particles used as the constituent material of the coating layer are used. It is possible to prevent the fixing property from being significantly impaired. Moreover, if the ratio of molecular weight 1000 or less is 10.0% or less, the contamination of the member by the thermally unstable low molecular weight component can be prevented.

  As a method for reducing the ratio of the low molecular weight component in the resin (a) described above, the resin (a) is dissolved in a solvent, the resin solution is left in contact with water, and only the low molecular weight component is brought to the water side. A method of removing by transferring can be used.

  For the purpose of adjusting the molecular weight, resins having two or more kinds of molecular weights may be mixed and used.

  A known colorant can be used for the core (A) in the present invention, and examples thereof include carbon black as a black colorant, magnetic powder, and yellow / magenta / cyan colorants shown below.

  Examples of the yellow colorant include the following. Condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 are preferably used.

  Examples of the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. 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, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used.

  Examples of the cyan colorant include the following. Copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 are preferably used.

  These colorants can be used alone or in combination, and further in a solid solution state. When magnetic powder is used as the black colorant, the amount added is preferably 40 to 150 parts by mass with respect to 100 parts by mass of the resin (a) in the core (A). When carbon black is used as the black colorant, the amount added is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the resin (a) in the core (A). 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 the resin (a) in the core (A). It is 1-20 mass parts with respect to 100 mass parts.

  It is necessary to pay attention to the water phase transferability of these colorants, and it is preferable to perform surface modification such as hydrophobization treatment as necessary. For example, a preferable method for surface-treating a dye-based colorant includes a method of polymerizing a polymerizable monomer in the presence of a dye in advance. For carbon black, in addition to the same treatment as the above dye, a grafting treatment may be performed with a substance that reacts with the surface functional group of carbon black, for example, polyorganosiloxane.

  Further, the magnetic powder is mainly composed of iron oxide such as triiron tetroxide and γ-iron oxide, and it is preferable to uniformly hydrophobize the surface with a coupling agent. Examples of the coupling agent that can be used include a silane coupling agent and a titanium coupling agent, and a silane coupling agent is particularly preferably used.

The core (A) in the present invention is preferably encapsulated with wax in order to improve fixability. Usable waxes include the following.
Petroleum wax such as paraffin wax, microcrystalline wax, petrolatum and derivatives thereof; montan wax and derivatives thereof; hydrocarbon wax and derivatives thereof according to Fischer-Tropsch method; polyolefin wax and derivatives thereof typified by polyethylene; carnauba wax and candelilla Natural waxes such as waxes and derivatives thereof. Derivatives include block copolymers with oxides and vinyl monomers, and graft modified products. Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes and animal waxes can also be used. These waxes may be used alone or in combination of two or more.

  Among these waxes, those having a maximum endothermic peak in a temperature range of 40 to 130 ° C. at the time of temperature rise in a DSC curve measured by a differential differential calorimeter are preferable, and further those having a temperature in a range of 45 to 120 ° C. Is more preferable. By using such a wax, the releasability can be effectively expressed while greatly contributing to the low-temperature fixability.

  The content of the wax is preferably 1 to 30 parts by mass and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the resin (a) in the core (A). When the content of the wax is less than 1 part by mass, a sufficient addition effect cannot be obtained, and the offset suppression effect also decreases. On the other hand, when the amount exceeds 30 parts by mass, the long-term storage stability is deteriorated, the dispersibility of the colorant and other toner materials is deteriorated, and the fluidity of the toner and the image characteristics are easily deteriorated. Further, the wax component oozes out at the time of fixing, and the durability under high temperature and high humidity is lowered.

  The core (A) in the present invention may contain a crystalline polyester. As the crystalline polyester, a resin obtained by condensation polymerization of an alcohol component mainly containing an aliphatic diol and a carboxylic acid component mainly containing an aliphatic dicarboxylic acid compound is used.

Examples of the aliphatic diol include the following. Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-butenediol. Among these, 1,4-butanediol and 1,6-hexanediol are preferable.
Moreover, the polyhydric alcohol component other than aliphatic diol may be contained, and the following are mentioned. Alkylene of bisphenol A such as polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane ( Carbon number 2 to 3) Oxide (average added mole number 1 to 10) adduct; a trihydric or higher polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane.

The following are mentioned as an aliphatic dicarboxylic acid compound. Oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid; and their anhydrides , Alkyl (C1-3) esters. Among these, fumaric acid and adipic acid are preferable.
Moreover, the polyvalent carboxylic acid component other than an aliphatic dicarboxylic acid compound may be contained, and the following are mentioned. Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; trivalent or higher polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid; and acid anhydrides thereof , Alkyl (C1-3) esters.

  The resin (b) constituting the intermediate layer (B) needs to be capable of forming an aqueous dispersion of resin fine particles (b ′) and contains at least a functional group that can exhibit self-dispersibility in water. Use resin. Specific examples of functional groups that can exhibit self-dispersibility in water include carboxylic acid groups, sulfonic acid groups, and salts thereof.

  Among these functional groups, it is preferable to use a resin containing at least a sulfonic acid group having a particularly high polarity or a sulfonate group. The sulfonic acid value is preferably 10.0 mgKOH / g or more and 30.0 mgKOH / g or less, and more preferably 15.0 mgKOH / g or more and 25.0 mgKOH / g or less.

  The material of the resin (b) is not particularly limited as long as it is used as a normal toner binder resin. Vinyl resin, polyester resin, polyurethane resin, epoxy resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin. These resins may be used alone or in combination of two or more.

  Among these resins, vinyl resins, polyester resins, polyurethane resins, and epoxy resins are more preferable from the viewpoint of easy formation of an aqueous dispersion. In addition, a polyurethane resin is particularly preferable because it has durability against an organic solvent and also needs moderate affinity.

  The polyurethane resin will be described in detail below.

  The polyurethane resin used for the core particles in the present invention is a resin containing a resin that is a reaction product of a diol component and a diisocyanate component, and it is possible to obtain a resin having various functions by adjusting the type and mixing ratio of these components. it can.

  Examples of the diisocyanate component include the following. C6-C20 aromatic diisocyanate, C2-C18 aliphatic diisocyanate, C4-C15 alicyclic diisocyanate, C8-C15 aromatic Group hydrocarbon diisocyanates and modified products of these diisocyanates (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group, oxazolidone group-containing modified product, hereinafter also referred to as modified diisocyanate). ), And a mixture of two or more of these.

  The following are mentioned as said aromatic diisocyanate. 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate.

  Moreover, the following are mentioned as said aliphatic diisocyanate. Ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, Bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

  Moreover, the following are mentioned as said alicyclic diisocyanate. Isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) -4-cyclohexene-1,2-di Carboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate.

  Among these, preferred are aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms, and particularly preferred are hexamethylene diisocyanate and isophorone diisocyanate. is there.

  In addition to the diisocyanate component, a trifunctional or higher functional isocyanate compound may be used. Examples of the trifunctional or higher functional isocyanate compound include the following. Polyallyl polyisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate.

  Examples of the diol component include the following. Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, octanediol, decanediol, dodecanediol, tetradecanediol, neopentyl glycol, 2,2 -Alkylene glycols such as diethyl-1,3-propanediol; alkylene ether glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol; 1,4-cyclohexanedimethanol, hydrogen Alicyclic diols such as bisphenol A added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide) adducts, alkylene oxide of the bisphenols (ethylene oxide, propylene oxide, butylene oxide) adducts; poly ε- caprolactone diol, polybutadiene diol.

  Among these, those having an alkyl structure are preferable from the viewpoint of solubility in an organic solvent, and it is particularly preferable to use an alkylene glycol having 2 to 12 carbon atoms.

  In addition to the diol component, a polyester oligomer having a terminal hydroxyl group (terminal diol polyester oligomer) can also be used as a suitable diol component.

  At this time, if the molecular weight of the terminal diol polyester oligomer is too large, the reactivity with the isocyanate compound is lowered, and the properties of the polyester become too strong and become soluble in an organic solvent. Therefore, the molecular weight (number average molecular weight) of the terminal diol polyester oligomer is preferably 3000 or less, more preferably 800 or more and 2000 or less.

  Moreover, when there is too much content of the said terminal diol polyester oligomer, the reaction material of a diol component and a diisocyanate component may become soluble in an organic solvent, and when too little, a diol component, a diisocyanate component, In some cases, the reaction product becomes thermally hard and inhibits the fixing property. Therefore, the content of the terminal diol polyester oligomer is preferably 1 mol% or more and 10 mol% or less, more preferably 3 mol% or more, in the monomer constituting the reaction product of the diol component and the diisocyanate component. 6 mol% or less.

  The terminal diol polyester oligomer may have an ether bond modified with ethylene oxide or propylene oxide.

  The polyurethane resin may contain a urea bond formed by a reaction between an amino compound and an isocyanate compound in combination.

  The following are mentioned as said amino compound. Diaminoethane, diaminopropane, diaminobutane, diaminohexane, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophoronediamine), 4,4′-diaminodicyclohexylmethane, Diamines such as 1,4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate; triamines such as triethylamine, diethylenetriamine, 1,8-diamino-4-aminomethyloctane.

  In addition to the above, the polyurethane resin can be used in combination with a reaction product of an isocyanate compound and a compound having a highly reactive hydrogen group such as a carboxylic acid group, a cyano group, or a thiol group. .

  Further, the polyurethane resin preferably has a carboxylic acid group, a sulfonic acid group, or a base thereof in the side chain from the viewpoint of easily forming an aqueous dispersion. In particular, a sulfonic acid group and a sulfonic acid group are more preferable in that they have high polarity and are excellent in stability to an organic solvent.

  As a method for introducing a carboxylic acid group, a sulfonic acid group, or a base thereof into the side chain, a diol component having these groups in the side chain may be used. Examples of the diol component having a carboxylic acid group or a carboxylic acid group in the side chain include the following. Dihydroxylcarboxylic acids such as dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, dimethylolpentanoic acid, and metal salts thereof.

  On the other hand, the following are mentioned as a diol component which has a sulfonic acid group or a sulfonate group in a side chain. Sulfoisophthalic acid, N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid and its metal salt.

  And when there is little content of the diol component which has these groups in a side chain, the dispersibility when it is set as the aqueous dispersion of resin fine particles falls, and granulation property may be impaired. On the other hand, when the amount is too large, the reaction product of the diol component and the diisocyanate component is easily dissolved in the aqueous medium, and may not function as a dispersant. Therefore, the content of the diol component having these groups in the side chain is such that the total is 10 mol% or more and 50 mol% or less with respect to all monomers forming the reaction product of the diol component and the diisocyanate component. Preferably, it is 15 mol% or more and 25 mol% or less.

  The method for producing the resin fine particles (b ′) containing the resin (b) as a main component is not particularly limited, and emulsion polymerization, soap-free emulsion polymerization, phase inversion emulsion, A method of liquefying by dissolving in an organic solvent and suspending in an aqueous medium and granulating can be used. Among these production methods, the phase inversion emulsification method is particularly suitable because it does not require an emulsifier or a dispersion stabilizer and resin particles having a smaller particle diameter can be easily obtained.

  In the phase inversion emulsification method, a resin having self-emulsifying property or a resin capable of expressing self-emulsifying property by neutralization is used. Here, the resin having a self-emulsifying property is a resin containing a functional group capable of self-dispersion in an aqueous medium in the molecule, specifically, a carboxylic acid group, a sulfonic acid group, a phosphoric acid group or It is a resin containing these salts. Further, the resin capable of exhibiting self-emulsifying property by neutralization is a resin containing a functional group in the molecule that can increase the hydrophilicity by neutralization and enable self-dispersion in an aqueous medium.

  When these self-emulsifying resins are dissolved in an organic solvent, a neutralizing agent is added if necessary, and mixed with an aqueous medium while stirring, the resin solution causes phase inversion emulsification to produce fine particles. To do. The organic solvent is removed using a method such as heating and decompression after phase inversion emulsification.

  Thus, according to the phase inversion emulsification method, a stable aqueous dispersion of resin fine particles can be obtained without substantially using an emulsifier or a dispersion stabilizer due to the action of the functional group. The resin fine particles thus obtained may be used as an aqueous dispersion for forming droplets of the binder resin solution. Further, an acid may be added to the aqueous dispersion to return the acidic group in the resin from a salt state to an acid state, and after filtration and washing, the acid group may be redispersed in water and used.

  Moreover, the said organic solvent will not be specifically limited if the said resin (b) is melt | dissolved, The following are mentioned. Hydrocarbon solvents such as xylene and hexane; halogenated hydrocarbon solvents such as methylene chloride, chloroform and dichloroethane; ester solvents such as methyl acetate, ethyl acetate, butyl acetate and isopropyl acetate; ether solvents such as diethyl ether; Ketone solvents such as acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexane. Among these, it is more preferable to use a low boiling point organic solvent that can be easily removed.

  When the particle size of the resin fine particles (b ′) is too small, the granulation stability at the time of forming droplets of the binder resin solution tends to be lowered. When it is too large, it becomes difficult to control the particle diameter of the core particles to be formed to a desired size. Therefore, the particle diameter of the resin fine particles (b ′) is preferably 30 nm or more and 300 nm or less in terms of number average particle diameter. More preferably, it is 50 nm or more and 100 nm or less.

  A particularly preferred example of the method for producing the core particles by the dissolution suspension method will be described in detail.

  Examples of organic solvents that can dissolve the resin (a) and are immiscible with water include the following. Hydrocarbon solvents such as xylene and hexane; halogenated hydrocarbon solvents such as methylene chloride, chloroform and dichloroethane; ester solvents such as methyl acetate, ethyl acetate, butyl acetate and isopropyl acetate; ether solvents such as diethyl ether; Ketone solvents such as acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexane.

  In preparing the resin composition described above, the resin (a) is preferably used in the form of a solution previously dissolved in the organic solvent. In this case, although it varies depending on the solubility of the resin (a) and the viscosity of the solution, the resin component is preferably blended in the range of 40 to 60% by mass in consideration of the ease of production in the next step. Moreover, you may heat below the boiling point of an organic solvent at the time of melt | dissolution.

  The wax is preferably in the form of being dispersed in the organic solvent. In other words, it is preferable to disperse a wet or dry mechanically pulverized wax in an organic solvent and use it as a wax dispersion. At this time, the dispersibility of the wax can be further improved by adding a dispersant to the wax dispersion.

  Similarly, the colorant is preferably used as a colorant dispersion liquid dispersed in the organic solvent. In order to increase the dispersibility of the colorant, it is particularly preferable to use it dispersed together with the resin (a). Hereinafter, a method for preparing the colorant dispersion will be described with examples.

(1) Wet dispersion (media dispersion)
The colorant, the resin (a), other additives and the organic solvent are mixed, and the mixture is dispersed using a disperser in the presence of the dispersion medium. Then, the dispersion medium is recovered, and the colorant dispersion is obtained. How to get. As the dispersing machine, for example, an attritor (manufactured by Mitsui Miike Koki Co., Ltd.) is used. Examples of the dispersing medium include alumina, zirconia, glass, and iron beads, but zirconia beads with very little media contamination are preferable. The bead diameter is preferably 2 to 5 mm in view of good dispersibility.

(2) Dry kneading Colorant, resin (a), and other additives are melt kneaded with a kneader or roll type disperser (dry type), and the resulting melt kneaded material is pulverized and then dissolved in the organic solvent. Is the method.

  When a colorant dispersion is prepared by these methods and then subjected to a dispersion treatment using ultrasonic waves, the aggregates of the colorant in the dispersion are loosened and further fine dispersion is possible.

  The resin composition can be prepared by blending a desired amount of the resin (a) solution, wax dispersion, and colorant dispersion in the organic solvent and dispersing them.

  The aqueous medium may be water alone, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include the following. Alcohols such as methanol, isopropanol and ethylene glycol; lower ketones such as acetone and methyl ethyl ketone; dimethylformamide, tetrahydrofuran and methyl cellosolve. In particular, it is preferable to mix an appropriate amount of an organic solvent used in the binder resin solution because the stability of droplets during granulation can be improved.

  In the present invention, a predetermined amount of resin fine particles (b ′) are dispersed in the aqueous medium. The blending amount of the resin fine particles (b ′) is preferably 3.0 parts by mass or more and 10.0 parts by mass or less with respect to the solid content in the binder resin solution used for forming droplets. In addition, it may be appropriately adjusted according to the stability of the droplet and the desired particle size of the core particle.

  In addition, a known surfactant, dispersant, water-soluble polymer, or viscosity modifier can be added to the aqueous medium.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. These can be arbitrarily selected according to the polarity at the time of core particle formation, and the following can be mentioned. Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters; alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt type cationic surfactants such as imidazoline; alkyltrimethylammoni Salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, quaternary ammonium salt type cationic surfactants such as benzethonium chloride; non-fatty acid amide derivatives, polyhydric alcohol derivatives, etc. Ionic surfactants; amphoteric surfactants such as alanine, dodecyl di (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine.

  The following are mentioned as said dispersing agent. Acids such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride; β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate , Β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxy methacrylate Hydroxy acids such as propyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylolacrylamide, N-methylolmethacrylamide (Meth) acrylic monomers containing groups; ethers with vinyl alcohol such as vinyl alcohol, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether; vinyl such as vinyl acetate, vinyl propionate, vinyl butyrate Esters of compounds containing alcohol and carboxylic acid groups; acrylamide, methacrylamide, diacetone acrylamide or methylol compounds thereof; acid chlorides such as acrylic acid chloride and methacrylic acid chloride; vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene Homopolymers or copolymers of compounds having a nitrogen atom such as imine or a heterocyclic ring thereof; polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene amine Polyoxyethylenes such as killamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester; methylcellulose; Celluloses such as hydroxyethyl cellulose and hydroxypropyl cellulose.

  The core particles are prepared by dispersing the resin composition in an aqueous medium in which the resin fine particles (b ′) are dispersed. At this time, the dispersion method is not particularly limited, and a low-speed shearing method, a high-speed shearing method, a friction method, a high-pressure jet method, an ultrasonic method, and the like can be used. In order to make it about 10 μm, a high speed shearing method is preferable.

  When the dispersion is performed using a high-speed shearing disperser, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, and preferably 3000 to 20000 rpm. The time required for dispersion is usually 0.1 to 5 minutes in the case of a batch method. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 10 to 100 ° C.

  In order to form the core particles, it is necessary to remove the organic solvent from the obtained droplets of the resin composition and solidify it. As a method for removing the organic solvent, a method of gradually heating or depressurizing the entire system and distilling it through an aqueous medium can be employed.

  Thus, the core particle which provided the intermediate | middle layer (B) on the surface of the core (A) can be formed.

  Hereinafter, the surface layer (C) which is a feature of the present invention will be described in detail.

  In the present invention, the surface layer (C) is formed using resin fine particles (c ′) containing the resin (c) as a main component. Therefore, a resin capable of forming an aqueous dispersion of resin fine particles (c ′) is used for the resin (c). Specifically, a resin containing the same functional group as the resin (b) used for forming the intermediate layer (B) can be used, but in the present invention, the polarity is lower than that of the resin (b). Use resin.

  That is, the resin (c) is preferably a resin that contains at least a carboxylic acid group or a carboxylic acid group, does not contain a sulfonic acid group or a sulfonic acid group, or has a low content. The carboxylic acid value is preferably 5.0 mgKOH / g or more and 25.0 mgKOH / g or less, and more preferably 10.0 mgKOH / g or more and 15.0 mgKOH / g or less.

  Further, the material of the resin (c) may be any material as long as it is used as an ordinary binder resin for toner, and in particular, durability to an organic solvent such as the resin (b) is not required. In addition, vinyl resins and polyester resins can also be suitably used.

  The method for producing the resin fine particles (c ′) is not particularly limited. Similarly to the resin fine particles (b ′), the emulsion polymerization method, the soap-free emulsion polymerization method, the phase inversion emulsion method, the resin is melted or organic A method of dissolving in a solvent to liquefy and suspending in an aqueous medium and granulating can be used.

  When the resin fine particles (c ′) are attached to the surface of the core particles, an aqueous dispersion of the resin fine particles (c ′) is mixed in an aqueous medium in which the core particles are dispersed. Thereafter, the dispersibility of the resin fine particles (c ′) is destabilized by a method of adding a water-soluble inorganic salt in an aqueous medium or a method of adjusting the pH by dropping an acid or an alkali, Aggregate on the surface.

  As described above, the core particles in the present invention have a structure in which the fine resin particles (b ′) used as a dispersion stabilizer cover the surface of the core (A) as the intermediate layer (B). Therefore, when the dispersion of the resin fine particles (c ′) is destabilized by lowering the pH of the aqueous medium in the state where the core particles and the resin fine particles (c ′) coexist in the aqueous medium, As described above, an electrical attractive force acts between the core particles and the resin fine particles (c ′).

  Therefore, the resin fine particles (c ′) can be more uniformly attached to the surface of the core particles, and a more uniform and strong surface layer (C) can be formed.

  In addition, if the dispersibility of the resin fine particles (c ′) is rapidly changed, the resin fine particles (c ′) are agglomerated alone to form a non-uniform adhesion state. Therefore, these operations need to be performed gradually. .

  In the present invention, the organic solvent dissolved in the aqueous medium is completely removed by mixing the aqueous dispersion containing the resin fine particles (c ′) into the aqueous medium in which the core particles are dispersed. Preferably it is done before. By doing so, it is possible to improve the adhesion strength when the resin fine particles (c ′) are adhered to the surface of the core particle, and it is possible to form the surface layer (C) having excellent adhesion.

  A suitable concentration of the organic solvent remaining in the aqueous medium is 0.1% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less.

  Further, after the resin fine particles (c ′) are adhered, it is preferable to perform fixing or fusing so as not to easily peel and drop off. As a specific method, a method of heat-treating in a state dispersed in an aqueous medium, a solvent that dissolves or swells resin fine particles (c ′) is added and absorbed, and after forming a film, the solvent is removed. Examples thereof include a method, a method of stirring and mixing the powder taken out by filtration and drying under heating. Among these methods, the heat treatment method in an aqueous medium is preferable in that it can be fixed more uniformly and firmly and the operation is simple.

  A suitable heat treatment temperature is a glass that is not less than the glass transition temperature of the resin (b) and not more than the glass transition temperature of the resin (c), but the resin fine particles (c ′) are sufficiently high with respect to the core particles. When it does not have a transition temperature, care must be taken because even the core particles may cause fusion.

  In addition, when the amount of the resin fine particles (c ′) to be attached is small, it is necessary to pay attention to the fusion of the core particles. The amount of the resin fine particles (c ′) used in the coating layer formed on the surface of the core particles is preferably 2.0 parts by mass or more and 10.0 parts by mass or less with respect to the amount of the core particles.

  In the present invention, the surface layer (C) formed by the resin fine particles (c ′) preferably covers 90% or more of the surface of the core particle, and particularly preferably 100%. A suitable use amount of the resin fine particles (c ′) for satisfying such a coverage is not uniquely determined, and is appropriately determined according to the particle diameters of the core particles and the resin fine particles (c ′). Adjust it. Further, the resin fine particles (c ′) to be fixed do not necessarily need to be a single layer, and may be a multilayer in order to cover 100%.

  As described above, it is possible to obtain a toner having a capsule structure having a coating layer that is a thin layer and is homogeneous and excellent in mechanical strength.

  The coverage can also be obtained directly from an observation image of each toner cross section by a transmission electron microscope (TEM). However, an element inherent to the resin constituting the resin fine particles (for example, S derived from a sulfonic acid group). In the case of containing an element), the element can be quantitatively analyzed using a fluorescent X-ray analyzer (XRF), for example, and calculated.

  The toner of the present invention can contain a charge control agent as needed for the purpose of stabilizing the charging performance. As a method of inclusion, there are a method of adding to the inside of toner particles and a method of adding externally. In addition, when added inside the toner particles, the charge control agent may be contained in the core particles or in the coating layer.

  As the charge control agent, known ones can be used, but when added inside, a charge control agent that substantially does not contain a soluble material in an aqueous medium is particularly preferable. Specific examples of the negative charge control agent include the following compounds. Metallic compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid; metal salts or metal complexes of azo dyes or azo pigments; polymer type having sulfonic acid or carboxylic acid group in the side chain Compound: Boron compound, urea compound, silicon compound, calixarene.

  The amount of these charge control agents to be used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and a dispersion method, and is not uniquely limited. When added internally, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin (a). In the case of external addition, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner particles.

  The weight average particle diameter of the toner obtained by the present invention is preferably 3.0 to 10.0 μm in order to faithfully develop a finer electrostatic latent image dot and obtain a high-quality image.

  The average circularity of the toner obtained by the present invention is preferably 0.970 or more. A toner having a shape close to a sphere like this tends to make frictional charging uniform, and is effective in suppressing fogging and sleeve ghosting. Further, since the toner ears formed on the toner carrier are uniform, control in the developing unit is facilitated. Furthermore, since it has a spherical shape, it has good fluidity and is not easily stressed in the developing device, so that the chargeability is not easily lowered even when used for a long time under high humidity. Further, since heat and pressure are easily applied to the entire toner even at the time of fixing, it contributes to improvement of fixing properties.

  The toner of the present invention is preferably externally added with a fluidity improver to improve image quality. The following inorganic fine powder is preferably used as the fluidity improver. Silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara , Antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride. These inorganic fine powders may be used alone or in combination.

The primary particle diameter of the inorganic fine powder is preferably 5 nm or more and 2 μm or less, and more preferably 5 nm or more and 500 nm or less. Further, the specific surface area of the inorganic fine particles by BET method is preferably 20 m ² / g or more and 500 m ² / g or less.

  The amount of the inorganic fine powder used is preferably 0.01 parts by mass or more and 5 parts by mass or less, and 0.01 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the toner particles. It is more preferable.

  The inorganic fine powder is preferably hydrophobized using a surface treatment agent in order to prevent deterioration of the flow characteristics and charging characteristics of toner under high humidity. Examples of preferable surface treatment agents include silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. .

  The toner of the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a magnetic carrier. When used as a two-component developer, the average particle size of the carrier to be mixed is preferably 10 to 100 μm, and the toner concentration in the developer is preferably 2 to 15% by mass.

  Here, a method for measuring various physical properties of the toner or toner particles in the present invention and the resin fine particles used in the present invention will be described.

<Measurement of average particle size>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are measured by a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, Beckman 2) Effective measurement channel number 25,000 using “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) and attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” for measurement condition setting and measurement data analysis Measurement was performed on the channel, and the measurement data was analyzed and calculated.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  In the “Standard Measurement Method (SOM) Change 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, Inc.) The value obtained using the above was set. The threshold and noise level were automatically set by pressing the threshold / noise level measurement button. The current was set to 1600 μA, the gain was set to 2, the electrolyte was set to ISOTON II, and the aperture tube flash after the measurement was checked.

  In the “Pulse to Particle Size Conversion Setting Screen” of the dedicated software, the bin interval was set to logarithmic particle size, the particle size bin to 256 particle size bin, and the particle size range from 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic solution was placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod was stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  (2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion-exchanged water was added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W A predetermined amount of ion-exchanged water was added, and about 2 ml of the above-mentioned Contaminone N was added to this water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker was adjusted so that the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker was maximized.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) was irradiated with ultrasonic waves, about 10 mg of toner was added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion treatment was further continued for 60 seconds. In the ultrasonic dispersion, the water temperature in the water tank was 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 the sample stand, the electrolyte aqueous solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement was performed until the number of measured particles reached 50,000.

  (7) The measurement data was analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) were calculated. When the graph / volume% is set with the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The “average diameter” on the analysis / number statistics (arithmetic average) screen is the number average particle diameter (D1).

<Measurement of average circularity>
The average circularity of the toner was measured using a flow type particle image analyzer (FPIA-3000 type) manufactured by Sysmex Corporation.

  As a specific measurement method, an appropriate amount of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 20 ml of ion-exchanged water, and then 0.02 g of a measurement sample is added. Then, the dispersion is performed for 2 minutes using a desktop ultrasonic cleaner / disperser (for example, VS-150 manufactured by Vervo Creer) having an oscillation frequency of 50 kHz and an electric output of 150 W to obtain a dispersion for measurement. . In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC.

  For the measurement, the flow type particle image measuring apparatus equipped with a standard objective lens (10 times) is used, and a particle sheath (PSE-900A) manufactured by Sysmex Corporation is used as the sheath liquid. The dispersion liquid prepared according to the above procedure is introduced into the flow type particle image measuring apparatus, 3000 toner particles are measured in the total count mode, and the analysis particle diameter is limited to a circle equivalent diameter of 3.00 μm to 200.00 μm. The average circularity of the toner particles is obtained.

  In measurement, automatic focus adjustment is performed using standard latex particles (for example, a product obtained by diluting 5200A manufactured by Duke Scientific with ion-exchanged water) before the measurement is started. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples, a flow-type particle image measuring apparatus that has been calibrated by Sysmex Corporation and that has been issued a calibration certificate issued by Sysmex Corporation was used. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle diameter was limited to a circle equivalent diameter of 3.00 μm or more and 200.00 μm or less.

<Measurement of glass transition temperature>
The glass transition temperature of the resin constituting the toner and the resin fine particles can be obtained as follows using a differential scanning calorimeter (2920MDSC) manufactured by TA Instruments.

  First, about 6 mg of a sample is precisely weighed in an aluminum pan, and an empty aluminum pan is prepared as a reference pan. In a nitrogen atmosphere, the measurement temperature range is 20 to 150 ° C., the temperature rising rate is 2 ° C./min, and the modulation amplitude is ± 0. Measurement is performed under the conditions of 6 ° C. and a frequency of once / minute.

  From the reversing heat flow curve at the time of temperature rise obtained by measurement, draw a tangent line between the endothermic curve and the front and back baselines, find the midpoint of the straight line connecting the intersections of each tangent line, and this is the glass transition Let it be temperature.

<Measurement of zeta potential>
The zeta potential of the toner particles can be measured as follows using an ultrasonic zeta potential measuring device DT-1200 (manufactured by Dispersion Technology).

  First, pure water is prepared as a dispersion medium, and 0.5% by mass of toner particles is added thereto. At this time, if necessary, an appropriate amount of a nonionic surfactant that does not affect the zeta potential can be added. Next, after dispersing for 3 minutes using an ultrasonic disperser, stirring is performed while defoaming for 10 minutes to obtain a dispersion of toner particles. About the dispersion liquid obtained in this way, zeta potential is measured using the said apparatus. At this time, the pH of the dispersion is also measured.

  Next, an appropriate amount of a 1 mol / liter aqueous hydrochloric acid solution (if necessary, an aqueous 1 mol / liter potassium hydroxide solution) is added to the dispersion to adjust the pH of the dispersion to about 0.5, Similarly, the zeta potential is measured. Then, this operation is repeated while the pH of the dispersion is sequentially changed by about 0.5 until the zeta potential value turns positive.

  The pH and the zeta potential value thus obtained are plotted on a graph, and each plot is connected to create a pH-zeta potential curve. The pH indicating the isoelectric point is determined from the pH-zeta potential curve of the graph that created the pH value when the zeta potential is 0 mV.

<Measurement of acid value>
The acid value of the resin constituting the resin fine particles is represented by the amount of potassium hydroxide required to neutralize the functional group contained in 1 g of the resin, and is determined by the following method. The basic operation is based on JISK-0070. This method is particularly suitable for obtaining the acid value of a carboxylic acid group.

  1) First, 0.5 to 2.0 g of the sample is precisely weighed in a 300 ml beaker, and the weight at this time is defined as Wg. When the functional group of the sample is in a salt state, a sample that has been returned to an acid state in advance is used.

  2) To this, 150 ml of a mixed solution of toluene / ethanol (4/1) is added and dissolved.

  3) Titrate with 0.1 mol / l KOH ethanol solution. The titration can be performed, for example, using automatic titration using a potentiometric titration measuring device AT-400 (winworkstation) manufactured by Kyoto Electronics Co., Ltd. and an ABP-410 electric burette.

  4) The consumption of the KOH solution at this time is Sml. At the same time, a blank is measured, and the consumption of KOH at this time is defined as Bml.

5) Calculate the acid value according to the following formula. In the formula, f is a factor of KOH.
Acid value (mgKOH / g) = {(SB) × 0.1f × 56.1} / W

  Moreover, when calculating | requiring the acid value of the sulfonic acid group in resin fine particles, quantitative analysis of S element is performed, for example using a fluorescent X-ray-analysis apparatus (XRF), and the functional group equivalent contained in 1g of resin is made into potassium hydroxide. It can be calculated in terms of the amount.

<Measurement of water absorption>
The water absorption of the resin constituting the resin fine particles is determined by the following method.

  The sample is pulverized so as to have a center diameter of 10 μm or less and sufficiently dried.

  The amount of water absorption of the sample at a temperature of 40 ° C. and a relative humidity of 95% RH is measured using an adsorption analyzer Q5000SA manufactured by TA Instruments. The measurement method is described in the operation manual “Q Series Startup Guide” (Revised B, issued in February 2006) issued by TA, but the outline is as follows.

  Empty pans are set in the Q5000SA reference chamber and sample chamber, respectively, and zero adjustment is performed. Next, the sample is put into the pan on the sample chamber side, and measurement is started.

"Measurement condition"
・ Apparatus: Q5000SA manufactured by TA Instruments
・ Pan: Quartz deposition pan 957210.903 for Q5000SA
-Gas: Dry air-Sample amount: 1 to 2 mg
・ Temperature and humidity program step1: Hold for 30 minutes under conditions of temperature 40 ° C and relative humidity 0% RH step2: Hold for 60 minutes under conditions of temperature 40 ° C and relative humidity 95% RH step3: Temperature 40 ° C, relative humidity 0% RH Hold for 30 minutes under conditions

  From the obtained chart (illustrated in FIG. 1), analysis is performed as follows.

  A value obtained by subtracting the water content W1 (mass%) at the end of step 1 from the water content W2 (mass%) at the end of step 2 is defined as a water absorption (%) in a temperature 40 ° C. and relative humidity 95% RH environment.

<Measurement of particle diameter of resin fine particles>
The particle diameter of the resin fine particles was measured as a number average particle diameter using a Microtrac particle size distribution analyzer HRA (X-100) (manufactured by Nikkiso Co., Ltd.) with a range setting of 0.001 μm to 10 μm. In addition, water was used as the dilution solvent.

  Hereinafter, the production method of the present invention will be specifically described with reference to examples.

<Preparation of resin fine particle dispersion (1)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 20.5 parts by mass : 10.0 parts by mass-dimethylolpropanoic acid: 7.0 parts by mass-sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 10.5 parts by mass-isophorone diisocyanate: 5.0 Parts by mass, hexamethylene diisocyanate: 37.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20.0% by mass. This was designated as resin fine particle dispersion (1).

<Preparation of resin fine particle dispersion (2)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 22.0 parts by mass : 9.5 parts by mass-dimethylolpropanoic acid: 10.0 parts by mass-Sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 6.5 parts by mass-Isophorone diisocyanate: 5.0 Parts by mass, hexamethylene diisocyanate: 37.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20.0% by mass. This was designated as resin fine particle dispersion (2).

<Preparation of resin fine particle dispersion (3)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 21.0 parts by mass 11.0 parts by mass-dimethylolpropanoic acid: 3.5 parts by mass-sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 13.5 parts by mass-hexamethylene diisocyanate: 41. 0 parts by mass / acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20.0% by mass. This was designated as resin fine particle dispersion (3).

<Preparation of resin fine particle dispersion (4)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 22.0 parts by mass : 8.5 parts by mass-dimethylolpropanoic acid: 13.0 parts by mass-Sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 3.5 parts by mass-Isophorone diisocyanate: 11.0 Parts by mass, hexamethylene diisocyanate: 32.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20.0% by mass. This was designated as resin fine particle dispersion (4).

<Preparation of resin fine particle dispersion (5)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 18.5 parts by mass : 10.5 parts by mass-dimethylolpropanoic acid: 5.0 parts by mass-Sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 12.0 parts by mass-Isophorone diisocyanate: 15.0 Parts by mass, hexamethylene diisocyanate: 29.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20% by mass. This was designated as resin fine particle dispersion (5).

<Preparation of resin fine particle dispersion (6)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol, and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 18.2 parts by mass : 9.5 parts by mass-dimethylolpropanoic acid: 11.3 parts by mass-Sodium N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonate: 5.0 parts by mass-Isophorone diisocyanate: 21.0 Parts by mass, hexamethylene diisocyanate: 25.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.
Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20% by mass. This was designated as resin fine particle dispersion (6).

<Preparation of resin fine particle dispersion (7)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000, obtained from an equimolar mixture of propylene glycol, ethylene glycol, and butanediol, 40:50:10 mol, and terephthalic acid, isophthalic acid: 70.0 parts by mass Propanoic acid: 4.0 parts by mass, isophorone diisocyanate: 16.0 parts by mass, acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20% by mass. This was designated as resin fine particle dispersion (7).

<Preparation of resin fine particle dispersion (8)>
The following monomers were charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube, heated to 67 ° C. in a nitrogen atmosphere, and reacted for 1 hour with stirring.
Polyester diol having a number average molecular weight of about 2000 obtained from a 40:50:10 molar mixture of propylene glycol, ethylene glycol, and butanediol and an equimolar mixture of terephthalic acid and isophthalic acid: 25.2 parts by mass : 15.0 parts by mass-Dimethylolpropanoic acid: 3.8 parts by mass-Isophorone diisocyanate: 21.0 parts by mass-Hexamethylene diisocyanate: 25.0 parts by mass-Acetone: 12.0 parts by mass

  Next, 10.0 parts by mass of hexamethylene diisocyanate was added, and further reacted at a temperature of 67 ° C. for 30 minutes, followed by cooling.

  After further adding 20.0 parts by mass of acetone to the reaction product, 14.0 parts by mass of triethylamine was added and stirred. The acetone solution was added dropwise to 200.0 parts by mass of ion-exchanged water while stirring at 500 rpm to prepare a fine particle dispersion.

  Next, an elongation solution was carried out by adding an aqueous solution in which 10.0 parts by mass of ethylenediamine was dissolved in 20.0 parts by mass of 10% aqueous ammonia and reacting at 50 ° C. for 8 hours. Furthermore, ion-exchange water was added until the solid content concentration reached 20% by mass. This was designated as resin fine particle dispersion (8).

<Preparation of resin fine particle dispersion (9)>
The following monomers were charged into a reaction vessel equipped with a stirrer, condenser, thermometer and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 210 ° C. in a nitrogen atmosphere. Warmed and reacted for 5 hours with stirring.
-Bisphenol A-propylene oxide 2-mole adduct: 27.8 parts by mass-Ethylene glycol: 26.7 parts by mass-Terephthalic acid: 24.0 parts by mass-Isophthalic acid: 13.0 parts by mass-5-Sodium sulfoisophthalic acid : 8.5 parts by mass

  Next, the reaction was further carried out for 5 hours while reducing the pressure inside the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

  A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100.0 parts by mass of the obtained polyester resin and 75.0 parts by mass of butyl cellosolve, heated to 90 ° C. and dissolved, then 70 Cooled to ° C.

  Next, 18.0 parts by mass of a 1 mol / liter aqueous ammonia solution was added, and the mixture was stirred for 30 minutes while maintaining the above temperature. Then, 300.0 parts by mass of ion-exchanged water having a temperature of 70 ° C. was added and dispersed in water. It was. The obtained aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C.

  After cooling, ion-exchanged water was added to the obtained aqueous dispersion, and the solid content concentration in the dispersion was adjusted to 20.0% by mass. This was designated as resin fine particle dispersion (9).

<Preparation of resin fine particle dispersion (10)>
The following monomers were charged into a reaction vessel equipped with a stirrer, condenser, thermometer and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 210 ° C. in a nitrogen atmosphere. Warmed and reacted for 5 hours with stirring.
-Bisphenol A-propylene oxide 2 mol adduct: 45.0 parts by mass-Ethylene glycol: 9.5 parts by mass-Terephthalic acid: 28.5 parts by mass-Isophthalic acid: 13.0 parts by mass

  Next, 4.0 parts by mass of trimellitic anhydride was added, and the reaction was further carried out for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

  A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100.0 parts by mass of the obtained polyester resin and 75.0 parts by mass of butyl cellosolve, heated to 90 ° C. and dissolved, then 70 Cooled to ° C.

  Next, 18.0 parts by mass of a 1 mol / liter aqueous ammonia solution was added, and the mixture was stirred for 30 minutes while maintaining the above temperature. Then, 300.0 parts by mass of ion-exchanged water having a temperature of 70 ° C. was added and dispersed in water. It was. The obtained aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C.

  After cooling, ion-exchanged water was added to the obtained aqueous dispersion, and the solid content concentration in the dispersion was adjusted to 20.0% by mass. This was designated as resin fine particle dispersion (10).

<Preparation of resin fine particle dispersion (11)>
The following monomers were charged into a reaction vessel equipped with a stirrer, condenser, thermometer and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 210 ° C. in a nitrogen atmosphere. Warmed and reacted for 5 hours with stirring.
-Bisphenol A-propylene oxide 2 mol adduct: 30.5 parts by mass-Ethylene glycol: 24.0 parts by mass-Terephthalic acid: 24.0 parts by mass-Isophthalic acid: 12.5 parts by mass

  Next, 9.0 parts by mass of trimellitic anhydride was added, and the reaction was further performed for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

  A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100.0 parts by mass of the obtained polyester resin and 75.0 parts by mass of butyl cellosolve, heated to 90 ° C. and dissolved, then 70 Cooled to ° C.

  Next, 18.0 parts by mass of a 1 mol / liter aqueous ammonia solution was added, and the mixture was stirred for 30 minutes while maintaining the above temperature. Then, 300.0 parts by mass of ion-exchanged water having a temperature of 70 ° C. was added and dispersed in water. It was. The obtained aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C.

  After cooling, ion-exchanged water was added to the obtained aqueous dispersion, and the solid content concentration in the dispersion was adjusted to 20.0% by mass. This was designated as resin fine particle dispersion (11).

  Ion exchange water was added to the obtained aqueous dispersion to adjust the solid content concentration in the dispersion to 20% by mass to obtain a resin fine particle dispersion (7).

<Preparation of resin fine particle dispersion (12)>
A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 350.0 parts by mass of ion-exchanged water and 0.5 parts by mass of sodium dodecylbenzenesulfonate, and the temperature was raised to 90 ° C. in a nitrogen atmosphere. Then, 8 parts by mass of 2% aqueous hydrogen peroxide solution and 8 parts by mass of 2% ascorbic acid aqueous solution were added.

  Subsequently, the following monomer mixture, aqueous emulsifier solution and aqueous polymerization initiator solution were added dropwise over 5 hours with stirring.

(Monomer)
-Styrene: 75.5 parts by mass-Butyl methacrylate: 23.8 parts by mass-Methacrylic acid: 0.7 parts by mass-T-dodecyl mercaptan: 0.05 parts by mass (Emulsifier)
-Sodium dodecylbenzenesulfonate: 0.3 parts by mass-Polyoxyethylene nonylphenyl ether: 0.01 parts by mass-Ion exchange water: 20.0 parts by mass (Polymerization initiator)
-2% aqueous hydrogen peroxide solution: 40.0 parts by mass-2% aqueous ascorbic acid solution: 40.0 parts by mass

  After dropping, the polymerization reaction was further carried out for 2 hours while maintaining the above temperature, followed by cooling to obtain an aqueous dispersion of styrene / acrylic resin.

  Ion exchange water was added to the obtained aqueous dispersion to adjust the solid content concentration in the dispersion to 20.0% by mass. This was designated as resin fine particle dispersion (12).

<Preparation of resin fine particle dispersion (13)>
A styrene / acrylic resin aqueous dispersion was obtained in the same manner as in the preparation of the resin fine particle dispersion (12) except that the amount of the monomer charged was changed as follows.
-Styrene: 94.7 parts by mass-Methyl methacrylate: 3.0 parts by mass-Methacrylic acid: 2.3 parts by mass-T-dodecyl mercaptan: 0.05 parts by mass

  Ion exchange water was added to the obtained aqueous dispersion to adjust the solid content concentration in the dispersion to 20.0% by mass to obtain a resin fine particle dispersion (13).

  With respect to the resin fine particle dispersions (1) to (13) thus obtained, the number average particle diameter of the resin fine particles in each dispersion liquid is measured using a Microtrac particle size distribution analyzer HRA (X-100) (manufactured by Nikkiso Co., Ltd.). Measured.

  In addition, a part of each dispersion is extracted, filtered and washed, and then dried and taken out as a solid content. The resulting resin has an acid value, glass transition temperature, temperature 40 ° C., water absorption in a humidity 95% RH environment. Each amount was measured. The carboxylic acid value was determined by the above-described titration method, and the sulfonic acid value was determined by calculation from the quantitative result of S element by a fluorescent X-ray analyzer (XRF).

  The results are summarized in Table 1, respectively.

<Preparation of polyester resin (1)>
The following monomers and condensation catalyst were charged into a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube.
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 54.3 parts by mass Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane : 12.5 parts by mass-Terephthalic acid: 29.5 parts by mass-Trimellitic anhydride: 3.8 parts by mass-Dibutyltin oxide: 0.1 parts by mass

  Under a nitrogen atmosphere, the temperature in the reaction vessel was raised to 170 ° C., and the reaction was carried out for 7 hours while stirring and distilling off the produced methanol.

  Next, the temperature was gradually raised to 240 ° C., the reaction was carried out for 5 hours while distilling off the produced propylene glycol and water, and the reaction was further carried out under a reduced pressure of 20 mmHg.

  The produced solid content was taken out, cooled to room temperature, pulverized and granulated to obtain a polyester resin (1). The polyester resin (1) obtained had a glass transition temperature of 46 ° C. and an acid value of 16 mgKOH / g.

<Preparation of polyester resin solution (1)>
By putting 50.0 parts by mass of ethyl acetate into a closed vessel equipped with stirring blades, adding 50.0 parts by mass of the polyester resin (1) to the place where stirring is performed at 100 rpm, and stirring at room temperature for 10 hours. A polyester resin solution (1) was prepared.

<Preparation of polyester resin (2)>
A polyester resin (2) was obtained in the same manner as the polyester resin (1) except that the monomer charge was changed as follows. The polyester resin (2) obtained had a glass transition temperature of 31 ° C. and an acid value of 13 mgKOH / g.
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 61.4 parts by mass Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane : 6.3 parts by mass-Terephthalic acid: 20.8 parts by mass-Trimellitic anhydride: 3.4 parts by mass-Adipic acid: 8.1 parts by mass-Dibutyltin oxide: 0.1 parts by mass

<Preparation of polyester resin solution (2)>
A polyester resin solution (2) was prepared in the same manner as in the production of the polyester resin solution (1) except that the polyester resin (1) was replaced with the polyester resin (2).

<Preparation of polyester resin (3)>
A polyester resin (3) was obtained in the same manner as the polyester resin (1) except that the monomer charge was changed as follows. The polyester resin (3) obtained had a glass transition temperature of 58 ° C. and an acid value of 23 mgKOH / g.
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 61.0 parts by massPolyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane : 6.2 parts by mass, terephthalic acid: 25.2 parts by mass, trimellitic anhydride: 6.0 parts by mass, fumaric acid: 1.6 parts by mass, dibutyltin oxide: 0.1 parts by mass

<Preparation of polyester resin solution (3)>
A polyester resin solution (3) was prepared in the same manner except that the polyester resin (1) was replaced with the polyester resin (3) in the production of the polyester resin solution (1).

<Preparation of Colorant Dispersion (1)>
Polyester resin (1): 20.0 parts by mass Copper phthalocyanine pigment (CI Pigment Blue 15: 3): 20.0 parts by mass Ethyl acetate: 60.0 parts by mass

  After sufficiently premixing the material in the container, it was put into a heat-resistant container together with 20.0 parts by mass of 1 mm glass beads. This was dispersed with a paint shaker (manufactured by Toyo Seiki) for 3 hours, and then the glass beads were removed with a nylon mesh to obtain a colorant dispersion.

<Preparation of Colorant Dispersion (2)>
A colorant dispersion (2) was prepared in the same manner as in the preparation of the colorant dispersion (1) except that the polyester resin (2) was used instead of the polyester resin (1).

<Preparation of Colorant Dispersion (3)>
A colorant dispersion (3) was prepared in the same manner as in the preparation of the colorant dispersion (1) except that the polyester resin (3) was used instead of the polyester resin (1).

<Preparation of wax dispersion>
80.0 parts by mass of ethyl acetate and 20.0 parts by mass of carnauba wax (melting point: 81 ° C.) are charged into a container equipped with stirring blades, and the carnauba wax is dissolved in ethyl acetate by heating the inside to a temperature of 70 ° C. I let you.

  Subsequently, it cooled to 25 degreeC over 3 hours, stirring gently at 50 rpm, and the milky white liquid was obtained.

  Furthermore, this solution was put into a heat-resistant container together with 20.0 parts by weight of 1 mm glass beads, dispersed for 3 hours with a paint shaker (manufactured by Toyo Seiki), and then the glass beads were removed with a nylon mesh to disperse the wax. A liquid was obtained.

[Example 1]
(Preparation of binder resin solution)
Polyester resin solution (1) (resin solid content: 50 mass%): 148.0 mass parts Colorant dispersion (1) (pigment solid content: 20 mass%, resin solid content: 20 mass%): 40. 0 parts by mass, wax dispersion (wax solid content: 20% by mass): 50.0 parts by mass, triethylamine: 0.5 parts by mass, ethyl acetate: 11.5 parts by mass The binder resin solution was prepared by stirring and dispersing for 10 minutes at a rotational speed of 5000 rpm using (made by Special Machine Industries Co., Ltd.).

(Preparation of aqueous phase)
The following was put into a container, and the mixture was stirred for 1 minute at a rotational speed of 5000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to prepare an aqueous phase.
-Ion-exchange water: 225.5 parts by mass-Resin fine particle dispersion (1): 25.0 parts by mass (5.0 parts by mass of resin fine particles with respect to 100.0 parts by mass of solid content in the binder resin solution) )
-50% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries): 25.0 parts by mass-Ethyl acetate: 30.0 parts by mass

(Preparation of core particle dispersion)
The binder resin solution is introduced into the aqueous phase, and the mixture is stirred for 1 minute at 8000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to suspend the binder resin solution to form droplets. did.

  Next, a stirring blade was set in the container, the temperature inside the system was raised to 40 ° C. while stirring at 200 rpm, and the solvent was removed over 3 hours while reducing the pressure to 66.7 kPa to form core particles. .

  The dispersion obtained in this way is cooled to room temperature, then filtered, ion-exchanged water is added and redispersed, the solid content concentration in the dispersion is adjusted to 20.0% by mass, and the core particles are dispersed. A liquid was obtained.

(Production of toner particles)
To 100.0 parts by mass of the core particle dispersion (20.0 parts by mass of solid), 5.0 parts by mass (1.0 part by mass of solids) of the resin fine particle dispersion (10) was added with stirring.

  Then, a 0.2 mol / liter aqueous hydrochloric acid solution was added dropwise at a dropping rate of 0.005 liter / minute until the pH of the dispersion reached 2.0, and then stirring was continued for 30 minutes.

  Further, the temperature of the dispersion was raised to 60 ° C. and stirred for 3 hours while maintaining this temperature, then cooled, filtered, washed with water and dried to obtain toner particles.

(Production of toner)
Hydrophobic silica fine powder having a primary particle size of 12 nm and a BET specific surface area of 120 m ² / g, which is obtained by treating 100 parts by mass of silica fine powder with 10 parts by mass of hexamethyldisilazane and further with 10 parts by mass of silicone oil. The body was prepared. Next, 1.0 part by mass of the hydrophobic silica fine powder was added to 100.0 parts by mass of the toner particles, and mixed using a Henschel mixer (manufactured by Mitsui Miike Chemical Industries). Thus, the toner (1) of the present invention was produced.

[Example 2 , Reference Examples 3, 4, Examples 5 to 11]
In Example 1, the polyester resin solution (1) and the colorant dispersion (1) used in the step of preparing the binder resin solution, and the resin fine particle dispersion as the dispersion stabilizer used in the preparation step of the core particle dispersion (1) In the same manner as in Example 1 except that the resin fine particle dispersion (10) for the coating layer used in the toner particle production process is replaced with the materials shown in Table 2, respectively. 2) to (11) were prepared.

[Examples 12 to 19]
In Example 1, the addition amount of the resin fine particle dispersion (1) as a dispersion stabilizer used in the preparation process of the core particle dispersion, and the resin fine particle dispersion (10) for the coating layer used in the toner particle preparation process. The toners (12) to (19) of the present invention were prepared in the same manner as in Example 1 except that the addition amount of) was changed to the amount shown in Table 2.

[Comparative Example 1]
(Preparation of binder resin solution)
A binder resin solution was prepared in the same manner as in Example 1.

(Preparation of aqueous phase)
The following was put into a container, and the mixture was stirred for 1 minute at a rotational speed of 5000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to prepare an aqueous phase.
-Ion exchange water: 200.5 parts by mass-Resin fine particle dispersion (6): 50.0 parts by mass (10.0 parts by mass of resin fine particles with respect to 100.0 parts by mass of the solid content in the binder resin solution) )
-50% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries): 25.0 parts by mass-Ethyl acetate: 30.0 parts by mass

(Production of toner particles)
The binder resin solution is introduced into the aqueous phase, and the mixture is stirred for 1 minute at 8000 rpm using a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to suspend the binder resin solution to form droplets. did.

  Next, a stirring blade was set in the container, the temperature in the system was raised to 40 ° C. while stirring at 200 rpm, and the solvent was removed over 3 hours while the pressure was reduced to 66.7 kPa.

  After cooling, a 0.2 mol / liter hydrochloric acid aqueous solution was added until the pH of the dispersion reached 2.0, and stirring was further continued for 30 minutes, followed by filtration, washing with water and drying to obtain toner particles.

(Production of toner)
In the same manner as in Example 1, hydrophobic silica fine powder was mixed to prepare a toner (20) of Comparative Example.

[Comparative Example 2]
(Preparation of binder resin solution)
Polyester resin solution (1) (resin solid content: 50 mass%): 148.0 mass parts Colorant dispersion (1) (pigment solid content: 20 mass%, resin solid content: 20 mass%): 40. 0 parts by mass / wax dispersion (wax solid content: 20% by mass): 50.0 parts by mass / ethyl acetate: 12.0 parts by mass The above materials were put into a container and homodisper (Special Machine Industries Co., Ltd.) The binder resin solution was prepared by stirring and dispersing for 10 minutes at a rotational speed of 5000 rpm.

(Preparation of aqueous phase)
To 1152.0 parts by mass of ion-exchanged water, 390.0 parts by mass of a 0.1 mol / liter-sodium phosphate aqueous solution was added, and the temperature was adjusted to 60 ° C. while stirring using CLEARMIX (M Technique Co., Ltd.). Warmed up. To this, 58.0 parts by mass of 1.0 mol / liter-calcium chloride aqueous solution was added and stirring was continued to prepare an aqueous medium containing a dispersion stabilizer composed of tricalcium phosphate. After cooling to 30 ° C., Further, 100.0 parts by mass of ethyl acetate was mixed to prepare an aqueous phase.

(Preparation of core particle dispersion)
The binder resin solution is put into the aqueous phase, and the binder resin solution is suspended by stirring for 1 minute at a temperature of 30 ° C. and a rotational speed of 10,000 rpm using CLEARMIX (M Technique Co., Ltd.). Droplets were formed.

  Next, a stirring blade was set in the container, and the solvent was removed over 5 hours while maintaining the temperature in the system at 30 ° C. while stirring at 200 rpm and reducing the pressure to 66.7 kPa.

  After cooling, a 0.2 mol / liter aqueous hydrochloric acid solution was added until the pH of the dispersion reached 1.5, and stirring was continued for another 30 minutes, followed by filtration and washing with water to form core particles.

  Ion exchange water is added to this and reslurried, and 0.1 mol / liter sodium hydroxide aqueous solution is added to adjust the pH of the dispersion to 7.0, and the solid concentration in the dispersion is 20.0 mass. % To obtain a core particle dispersion.

(Production of toner particles)
To 100.0 parts by mass of the core particle dispersion (20.0 parts by mass of solids), 10.0 parts by mass (2.0 parts by mass of solids) of the resin fine particle dispersion (10) was added with stirring.

  Then, a 0.2 mol / liter aqueous hydrochloric acid solution was added dropwise at a dropping rate of 0.005 liter / minute until the pH of the dispersion reached 2.0, and then stirring was continued for 30 minutes.

  Further, the temperature of the dispersion was raised to 65 ° C. and stirred for 3 hours while maintaining this temperature, then cooled, filtered, washed with water and dried to obtain toner particles.

(Production of toner)
In the same manner as in Example 1, hydrophobic silica fine powder was mixed to prepare a toner (21) of Comparative Example.

[Comparative Examples 3 to 6]
In Example 1, the resin fine particle dispersion (1) as the dispersion stabilizer used in the preparation process of the core particle dispersion and the resin fine particle dispersion (10) for the coating layer used in the preparation process of the toner particles are used. Comparative toners (22) to (25) were prepared in the same manner as in Example 1 except that the fine particle dispersions shown in Table 2 were used.

For each of the toner particles produced in Examples 1 and 2, Reference Examples 3 and 4, Examples 5 to 19 and Comparative Examples 1 to 6, an ultrasonic zeta potential measurement device DT-1200 (manufactured by Dispersion Technology) is used. The zeta potential was measured, and the pH value (P1) indicating the isoelectric point was determined according to the method described above.

  Next, 2.0 g of each toner particle was put into 50 ml of ethyl acetate, subjected to ultrasonic treatment for 1 minute, 50 ml of ion-exchanged water was added, and ethyl acetate was removed by depressurization. Next, the zeta potential was measured in the same manner as described above, and the pH value (P2) indicating the isoelectric point was determined in the same manner.

  The obtained results are shown in Table 3 together with the average particle diameter and average circularity of each toner.

Next, with respect to the toners obtained in Examples 1 and 2, Reference Examples 3 and 4, Examples 5 to 19 and Comparative Examples 1 to 6 , blocking resistance, low-temperature fixability, chargeability (tribo), and continuous Evaluation of the image density reduction rate by image output was performed according to the following procedure. The results are summarized in Table 4.

<Blocking resistance>
10 g of toner is weighed into a 100 ml capacity polycup and placed in a thermostatic chamber with an internal temperature of 50 ° C. and left for 3 days. Thereafter, the polycup is taken out, and the state change of the toner inside is visually evaluated. Judgment criteria are as follows.
A: No change B: There is an aggregate, but loosens immediately C: A little aggregate, difficult to loosen D: Many aggregates, not easily loosened E: Not loosened at all

<Low temperature fixability>
A two-component developer is prepared by mixing toner and a magnetic fine particle-dispersed resin carrier (average particle diameter 35 μm) surface-coated with a silicone resin so that the toner concentration is 7.0% by mass.

  Next, the two-component developer is allowed to stand for 7 days at high temperature and high humidity (30 ° C./80%), and then left for another 3 days at room temperature and normal humidity (23 ° C./60%). Reset.

As a test machine, a commercially available full-color copying machine (CLC5000, manufactured by Canon) was used, and an unfixed toner image on the image receiving paper (80 g / m ² ) (toner applied amount per unit area 0.6 mg / m). cm ² ).

  The fixing test is performed using a fixing unit which is removed from the copying machine and modified so that the fixing temperature can be adjusted. The specific evaluation method is as follows.

  In a normal temperature and humidity environment (23 ° C, 60% RH), the process speed is set to 180 mm / s, the initial temperature is set to 120 ° C, and the set temperature is sequentially raised by 5 ° C, and the unfixed state at each temperature. Fix the image.

In the present invention, the low temperature fixability is the density reduction rate before and after rubbing when the low temperature offset is not observed and the obtained fixed image is rubbed 5 times with sylbon paper applied with a load of 4.9 kPa. Was the fixing start temperature, and the evaluation was made according to the following criteria.
A: Fixing start temperature is 120 ° C. or less (particularly excellent)
B: Fixing start temperature is higher than 120 ° C. and 130 ° C. or lower (good)
C: Fixing start temperature is greater than 130 ° C. and 145 ° C. or less (a level that is not a problem)
D: Fixing start temperature is higher than 145 ° C. and 160 ° C. or lower (somewhat inferior)
E: Fixing start temperature is higher than 160 ° C. (inferior)

<Evaluation of electrification (tribo)>
1.0 g and 19.0 g of toner and carrier (Japanese Image Society standard carrier, spherical carrier (N-01) with a ferrite core surface-treated) are placed in a plastic bottle and left in the environment for 24 hours. The environment is N / L (temperature 23 ° C., relative humidity 5%) and H / H (temperature 30 ° C., relative humidity 80%).

  The chargeability (tribo) was evaluated using the triboelectric charge amount of the toner.

  A method for measuring the triboelectric charge amount of the toner will be described below.

  First, the carrier and toner are put in a plastic bottle with a lid, and shaken for 1 minute at a speed of 4 reciprocations per second using a shaker (YS-LD, manufactured by Yayoi Co., Ltd.), and consists of toner and carrier. A developer is prepared and the toner is charged.

  Next, the triboelectric charge amount is measured using the measuring apparatus shown in FIG. In FIG. 2, about 0.5 to 1.5 g of the developer described above is placed in a metal measuring container 2 having a 500 mesh screen 3 at the bottom, and a metal lid 4 is formed. The mass of the entire measurement container at this time is weighed and is defined as W1 (g). Next, in the suction machine 1 (at least the part in contact with the measurement container 2) is sucked from the suction port 7, and the air volume control valve 6 is adjusted to set the pressure of the vacuum gauge 5 to 250 mmAq. In this state, suction is performed for 2 minutes to remove the toner in the developer by suction. The potential of the electrometer 9 at this time is set to V (volt). Here, 8 is a capacitor, and the capacity is C (mF). The mass of the entire measurement container after the suction is weighed and is defined as W2 (g).

The triboelectric charge amount (μC / g) of this sample is calculated as follows.
Sample triboelectric charge (μC / g) = C × V / (W1−W2)

<Image density reduction rate>
A commercially available color laser printer (LBP-5900SE, manufactured by Canon) was used to take out the toner from the cyan cartridge, and 150 g of the prepared toner was filled therein. The cartridge is installed in the cyan station of the printer, and 5000 sheets of a 2% printing rate chart are continuously obtained using image receiving paper (Canon office planner 64 g / m ² ) under normal temperature and humidity (23 ° C., 60% RH). And painted.

The image density before and after the image was measured with a Macbeth densitometer, and the decrease in the image density was evaluated according to the following evaluation criteria.
A: Image density decrease is less than 5% (image density decrease is very small)
B: Image density decrease is 5% or more and less than 10% (less decrease in image density)
C: Image density decrease is 10% or more and less than 15% (no problem in image density decrease)
D: Image density decrease is 15% or more and less than 20% (large decrease in image density)
E: Image density decrease is 20% or more (image density decrease is very large)

Claims (7)

Core having containing a colorant and a wax and a resin (a) mainly composed of polyester (A),
Intermediate layer mainly composed of resin (b) obtained by covering the core (A) (B), and,
Surface layer (C) mainly composed of resin (c) formed by coating intermediate layer (B)
A toner having toner particles comprising:
The resin (b) is a resin containing a sulfonic acid group and / or a sulfonic acid group,
The sulfonic acid value of the resin (b) is 10.0 mgKOH / g or more and 30.0 mgKOH / g or less,
The pH indicating the isoelectric point determined by measuring the zeta potential of the toner particles in water is P1, and the isoelectric point determined by measuring the zeta potential in water after ultrasonically treating the toner particles in ethyl acetate for 1 minute. A toner wherein P1 and P2 satisfy the following relational expressions (1) and (2) when the indicated pH is P2.
2.0 <P1 <4.0 (1)
P1-P2> 0.3 (2) The resin (c) is a resin having free carboxylic acid groups and / or carboxylate groups,
The carboxylic acid value of the resin (c) is, Ru der below 5.0 mgKOH / g or more on 2 5.0 mgKOH / g
The toner according to 請 Motomeko 1. The toner according to the resin (c), the water absorption amount when allowed to stand for 1 hour under the conditions of temperature 40 ° C. and a relative humidity of 95%, 2.5 mass% or less der Ru請 Motomeko 2. The glass transition temperature of the resin (a) is Tg (a) (° C.) , the glass transition temperature of the resin (b) is Tg (b) (° C.), and the glass transition temperature of the resin (c) is Tg ( when the c) (℃), Tg ( a), Tg (b) and Tg (c) is the following equation (3) to (5) to one to that請 Motomeko 1-3 of satisfying The toner described.
30 <Tg (a) <60 (3)
| Tg (b) −Tg (a) | <20 (4)
20 <Tg (c) −Tg (a) <50 (5) Wherein in the toner particles, the resin (b) is a content of not more than 3.0 mass% or more 1 0.0 weight percent, the content of the resin (c) is 2.0 wt% or more 1 0 .0 or less by mass%, one of the resin (b) and the resin der total less 1 5.0 wt% on 6.0% by mass or the content of (c) Ru請 Motomeko 1-4 of Toner according to. The surface layer (C) is, the resin composed mainly of a polyester (a) and the colorant and the core having containing a wax (A), and the resin obtained by coating the core (A) (b) intermediate layer mainly composed of the surface of the formed core particles (B), the resin (c) 請 Motomeko 1 Ru der those formed by impregnating resin fine particles (c ') consisting mainly of the toner according to any one of to 5. Organic the core particles, in an aqueous medium in which resin fine particles (b ') is dispersed mainly containing the resin (b), and the resin (a) and the colorant and the wax as a main component port Riesuteru dissolved or resin composition dispersed in a solvent are dispersed to obtain a dispersion liquid toner according to der Ru請 Motomeko 6 which was formed by removing the organic solvent from the dispersion.

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