JP2021173828A - Toner for electrostatic charge development and method for manufacturing the same - Google Patents

Abstract

To provide a toner for electrostatic charge development which has excellent low temperature fixability, and has both heat resistant storage property and fixing separability, and a method for manufacturing the same.SOLUTION: A toner for electrostatic charge development contains toner base particles containing a binder resin and a release agent, in which the binder resin contains an amorphous resin and a crystalline resin, and when a rising temperature of an endothermic peak derived from the crystalline resin in a first temperature rising process when differential scanning calorimetry is performed on the toner for electrostatic charge development is represented by T1°C, an endothermic peak temperature is represented by T2°C, and an endothermic peak derived from the release agent is represented by T3°C, conditions of T1 is 57-62°C, T2 is 60-70°C. T2≤T1+12°C and T2<T3≤T2+15°C are satisfied.SELECTED DRAWING: None

Description

The present invention relates to a toner for electrostatic charge development and a method for producing the same. More specifically, the present invention relates to an electrostatic charge developing toner having excellent low-temperature fixability, heat-resistant storage property, and fixing separability, and a method for producing the same.

Conventionally, as a fixing method of a toner for static charge image development (hereinafter, may be simply referred to as "toner"), a pressure fixing method using only a pressure roll at room temperature, a contact heating type fixing method using a heating roll or the like, or a contact heating type fixing method using a heating roll or the like, Non-contact fixing methods such as an oven fixing method using oven heating, a flash fixing method using a xenon lamp, an electromagnetic wave fixing method using microwaves, and a solvent fixing method using solvent vapor are adopted. Among these, the oven fixing method using heat and the contact heating type fixing method are mainly used from the viewpoint of reliability and safety.

In particular, the contact heating type fixing method using a heating roll or belt is usually composed of a heating roll or belt provided with a heating source and a pressure roll or belt, and a toner image surface of a transfer material is placed on the surface of the heating roll or belt. Fixing is performed by passing the material through pressure contact. As described above, the contact heating type fixing method has a feature that the surface of the heating roll or belt and the toner image surface of the transfer material are in direct contact with each other, so that the heat efficiency is effective and the fixing can be performed quickly. Widely adopted.

By the way, in these heat fixing methods, the time from when the power is turned on until the temperature of the fuser quickly rises to the operating temperature and becomes ready for fixing, that is, the so-called warm-up time is shortened, and the amount of energy used is reduced. Therefore, it is desired that it can be fixed at a lower temperature.

Especially in recent years, it has been desired to stop the energization of the fuser except during use in order to save energy thoroughly, and the temperature of the fixing member in the fuser needs to reach a temperature at which the fuser can be instantly fixed with the energization. , It is necessary to fix at a lower temperature. In addition, by lowering the fixing temperature, it is possible to increase the printing speed even with the same power consumption, and in the contact heating type fixing method, it is possible to extend the life of the fixing member such as a heating roll, which reduces the cost. It is also preferable from the aspect.

However, in the conventional method, lowering the fixing temperature of the toner also lowers the glass transition point of the toner, which makes it difficult to achieve both the storage stability of the toner and the storage stability of the toner. Therefore, in order to achieve both low-temperature fixing and toner storage stability, it is necessary to have a so-called sharp melt property in which the viscosity of the toner rapidly decreases in the high temperature region while keeping the glass transition point of the toner at a higher temperature. Is.

Resins normally used for toner, that is, amorphous resins, have a certain range of glass transition points, molecular weights, etc. Therefore, in order to obtain sharp meltability, it is necessary to make the resin composition and molecular weight extremely uniform. be. However, in order to obtain such a resin, it becomes necessary to adjust the molecular weight of the resin by using a special manufacturing method or by treating the resin by chromatography or the like, and the cost for producing the resin is high. It has to be expensive, and unnecessary resin is generated at that time, which is not preferable from the viewpoint of environmental protection in recent years.

In order to realize such low temperature fixability, a method of using a crystalline resin as a binder resin has been studied (see, for example, Patent Documents 1 and 2). By using the crystalline resin, the hardness of the toner is maintained below the melting point of the crystal, and when the temperature exceeds the melting point, the viscosity sharply decreases as the crystal melts, so that the toner can be fixed at a low temperature. However, the crystalline resins described in these patent documents have a problem that the fixing performance to the transfer material is not sufficient.

Examples of the crystalline resin expected to improve the fixability to the transfer material include a crystalline polyester resin. As an example of using a crystalline polyester resin as a toner, a method has been proposed in which a non-crystalline polyester having a glass transition temperature of 40 ° C. or higher and a crystalline polyester having a melting point of 130 ° C. to 200 ° C. are mixed and used. For example, see Patent Document 3). However, although this method has excellent crushability and blocking resistance, the high melting point of the crystalline polyester resin makes it impossible to achieve lower temperature fixability than before.

Further, there is an example in which a resin having a melting point of 110 ° C. or lower is used as the crystalline resin, and a non-crystalline resin is mixed and used as a toner (see, for example, Patent Document 4). However, when the amorphous resin is mixed with the crystalline resin, the melting point of the toner is lowered, which causes problems such as toner blocking and deterioration of powder fluidity.

Further, in these toners, a mold release agent is applied to the toner in order to improve the separability (fixing separability) when the heating roll or belt for fixing separates from the toner image on the transfer material after fixing the toner image on the transfer material. Is being contained. However, these toners have not been designed in consideration of the balance between the low-temperature fixability and the heat-resistant storage property of the toner in terms of fixing separability.

That is, it has been difficult to obtain a toner that satisfies all of low-temperature fixability, heat-resistant storage property, and fixing separability by the conventional techniques.

Special Publication No. 56-13943 Special Publication No. 63-25335 Special Publication No. 62-39428 Tokuhei 4-3014 Gazette

The present invention has been made in view of the above problems and situations, and the problem to be solved is the manufacture of a toner for static charge image development, which has excellent low-temperature fixability, heat-resistant storage property, and fixing separability. To provide a method.

In the process of investigating the cause of the above problem in order to solve the above problems, the present inventors differentially scan the toner in a static charge image developing toner in which the toner matrix particles contain a crystalline resin and a release agent. We focused on the respective heat absorption peaks that show the melting characteristics of the crystalline resin and the mold release agent when the calorific value was measured. Then, the melting start temperature (heat absorption peak rising temperature), melting point (heat absorption peak temperature) of the crystalline resin, the temperature difference between the melting start temperature and the melting point, and the melting point of the crystalline resin and the melting point of the mold release agent (heat absorption peak temperature). ), By adjusting the temperature difference within a specific range, it has been found that a toner for electrostatic charge image development having excellent low-temperature fixability, heat-resistant storage property, and fixing separability can be provided, leading to the present invention. rice field.
That is, the problem according to the present invention is solved by the following means.

1. 1. Toner containing a binder resin and a mold release agent A toner for developing an electrostatic charge image containing parent particles.
The binder resin contains an amorphous resin and a crystalline resin,
In the first heating process when the differential scanning calorimetry of the static charge image developing toner is performed, the rising temperature of the endothermic peak derived from the crystalline resin is T ₁ ° C, the endothermic peak temperature is T ₂ ° C, and A toner for static charge image development, which satisfies the following conditions (1), (2), (3) and (4) when the endothermic peak temperature derived from the mold release agent is T _{3 ° C.}
(1) T ₁ is in the range of 57 to 62 ° C.
(2) T ₂ is in the range of 60 to 70 ° C.
(3) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 12 ° C
(4) T ₂ and T ₃ have the following relationship.
T ₂ <T ₃ ≤ T ₂ + 15 ° C

2. The toner for static charge image development according to item 1, wherein the toner matrix particles have core particles and a shell layer that coats the core particles, and the crystalline resin is contained in the core particles. ..

3. 3. The first or second item, wherein the outflow start temperature measured by the flow tester of the static charge image developing toner is T _fb ° C., and the condition of the following (5) is further satisfied. Toner for static charge image development.
(5) T ₂ and T _fb have the following relationship.
T ₂ ≤ T _fb ≤ T ₂ + 10 ° C

4. The toner for static charge image development according to any one of items 1 to 3, further comprising satisfying the following conditions (6), (7) and (8).
(6) T ₁ is in the range of 60 to 61 ° C.
(7) T ₂ is in the range of 62 to 66 ° C.
(8) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 5 ° C

5. The item according to any one of items 1 to 4, wherein the crystalline resin contains a crystalline polyester resin, and the weight average molecular weight of the crystalline polyester resin is in the range of 2000 to 25000. Toner for static charge image development.

6. The toner for developing an electrostatic charge image according to Item 5, wherein the weight average molecular weight of the crystalline polyester resin is in the range of 4000 to 10000.

7. The content of the crystalline resin is in the range of 4 to 31 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the release agent is with respect to 100 parts by mass of the binder resin. The static charge image developing toner according to any one of items 1 to 6, wherein the toner is in the range of 6 to 20 parts by mass.

8. The item according to any one of items 1 to 7, wherein the content of the crystalline resin is in the range of 10 to 20 parts by mass with respect to 100 parts by mass of the binder resin. Toner for developing static charge images.

9. A method for producing an electrostatic charge image developing toner according to any one of items 1 to 8, wherein the electrostatic charge image developing toner is produced.
The first step of obtaining a dispersion liquid containing a toner matrix particle precursor by heating and stirring the fine particles containing the binder resin and the release agent in an aqueous medium to aggregate and fuse them.
A second step of cooling the dispersion heated in the first step to a temperature of 30 ° C. or lower at a temperature lowering rate of 6 ° C./min or more, and a second step.
A third step of maintaining the dispersion liquid cooled in the second step at a temperature in the range of 57 to 62 ° C. for 30 minutes or more,
A method for producing a toner for static charge image development, which comprises producing the toner matrix particles by a method including.

According to the above means of the present invention, it is possible to provide a toner for static charge image development and a method for producing the same, which has excellent low-temperature fixability, heat-resistant storage property, and fixing separability.
Although the mechanism of expression or mechanism of action of the effect of the present invention has not been clarified, it is inferred as follows.

In an electrophotographic system, in order to reduce the toner to a viscosity that can be fixed within an extremely short fixing nip time of several tens of milliseconds, a crystalline resin is contained in the binder resin of the toner matrix particles, and the plasticizing effect thereof. The point is how to maximize the performance. That is, it is necessary to quickly start melting the crystalline resin within the time until the toner placed on the transfer material such as paper finishes passing through the fixing nip, and quickly diffuse the melted crystalline resin over the entire toner matrix particles. There is. In order to increase the diffusion rate, it is an effective means to reduce the molecular weight of the crystalline resin.

However, the crystalline resin has a wide molecular weight distribution, a large number of crystal defects occur due to the influence of another material in the toner, and a wide melting point distribution from the viewpoint of compatibility with an amorphous resin or the like. If the melting point of the crystalline resin is lowered, the melting start temperature (the temperature at which the component having the lowest melting point starts to melt) also drops at the same time.

Further, when the toner is exposed to a high temperature during transportation or in the apparatus of the electrophotographic system, the toner aggregates and causes deterioration of the developer characteristics due to image failure and deterioration of fluidity. In order to suppress such toner aggregation, heat-resistant storage properties of about 60 ° C. are required unless special measures are taken. Therefore, in order to suppress the aggregation of toner as much as possible, it is necessary to eliminate the crystalline resin having a melting point lower than necessary.

Therefore, in the present invention, in order to minimize the influence on the quality due to the deterioration of the heat-resistant storage property, the start of melting of the crystalline resin when the toner is measured by differential scanning calorimetry (hereinafter, also referred to as “DSC”). The temperature (rising temperature T _{1 of the} heat absorption peak) was set to 57 ° C. or higher. Hereinafter, the chart obtained by DSC is referred to as "DSC curve". Furthermore, since the crystalline resin needs to melt quickly at the time of fixing and quickly wet and spread on the amorphous resin, _{the temperature difference between T 1} and the melting point corresponding to the end of melting (heat absorption peak temperature T ₂ in the DSC curve) is as much as possible. Smaller is desirable. If T ₁ is too low, the heat-resistant storage property will deteriorate, and if it is too high, the timing of the start of melting will be delayed, and the effect of low-temperature fixability will be diminished. Further, _{it is preferable that T 2} is low, but as described above, it is difficult to produce a crystalline resin having a narrow melting point distribution. _{If the melting point T 2} of the crystalline resin in the toner becomes too high, the timing of completion of melting will be delayed, and the effect of low temperature fixability will be diminished. In the toner of the present invention, taking all of these factors into consideration, _{the range of T 1} is 57 to 62 ° C, _{the range of T 2} is 60 to 70 ° C, and T ₂ ≤ T ₁ + 12 ° C. And low temperature fixability was ensured.

Further, in the toner of the present invention, in order to ensure heat storage performance and fixing separability, a mold release agent is contained in the toner base particles, and the melting point of the mold release agent in the toner (heat absorption peak temperature T _{3 in the DSC curve).} ) And the melting point T ₂ of the _{crystalline resin were defined as T 2} <T ₃ ≤ T ₂ + 15 ° C. The mechanism of action is considered to be as follows.

When the fixing nip is heated and the temperature rises, the crystalline resin melts while absorbing heat and is compatible with the amorphous resin to fix. In the DSC curve of the toner, when there is a region where the heat absorption peak derived from the mold release agent overlaps with the heat absorption peak derived from the crystalline resin, the heat energy transmitted from the fixing member not only melts the crystalline resin but also melts the mold release agent. As it is consumed and the melting of the crystalline resin is delayed, the rate at which the plasticizing effect of the crystalline resin is exerted decreases, and the effect of low temperature fixing is reduced. When the melting point T _{3 of the} release agent is equal to or less than the melting point T ₂ of the crystalline resin, the heat-resistant storage property deteriorates due to the increase of low melting point components below the _{specified temperature (T 1 in the present invention, 57 ° C. or higher).} do. Therefore, in the toner of the present invention, T ₂ <T ₃ is set.

Further, the separability between the toner image on the transfer material and the fixing belt at the time of fixing can be expressed by the relationship between the internal cohesive force of the molten toner and the adhesive force between the molten toner and the fixing belt. When the internal cohesive force of the toner becomes smaller than the adhesive force between the molten toner and the fixing belt, the molten toner becomes difficult to separate from the belt and causes poor separation. In the case of minor separation defects, the transfer material can be peeled off from the fixing belt, but the sparse presence of the release agent on the fixing image may cause image defects.

When the viscosity of the amorphous resin drops sharply due to the plasticizing effect of melting the crystalline resin and the internal cohesive force of the toner drops significantly, the melting point T ₃ of the mold release agent becomes the melting point T _{2 of the crystalline resin.} On the other hand, if it is significantly higher, the timing of reducing the adhesive force between the toner and the fixing belt is significantly delayed, which causes poor separation. Therefore, in the toner of the present invention, the melting point T ₃ of the release agent is set to be within the melting point T _{2 + 15 ° C. of the crystalline resin.}

The toner for static charge image development of the present invention is a toner for static charge image development containing toner matrix particles containing a binder resin and a mold release agent, and the binder resin is an amorphous resin and a crystalline resin. _{The rising temperature of the endothermic peak derived from the crystalline resin is T 1} ° C., and the endothermic peak temperature is T _{2 in the} first heating process when the toner for static charge image development is measured by differential scanning calorimetry. When the temperature and the endothermic peak temperature derived from the mold release agent are T ₃ ° C., the above conditions (1), (2), (3) and (4) are satisfied.
This feature is a technical feature common to each of the following embodiments.

In an embodiment of the present invention, the toner base particles have a core particle and a shell layer covering the core particle, from the viewpoint that the effect of the present invention, particularly the effect of heat-resistant storage property, can be exhibited more highly. It is preferable that the crystalline resin is contained in the core particles.

_{In the embodiment of the toner of the present invention, when the outflow start temperature measured by the flow tester of the toner is T fb} ° C., from the viewpoint that the effect of the present invention, particularly the effect of low temperature fixability, can be exhibited higher. Further, it is preferable to satisfy the condition of (5) above.

The T _fb of the toner is an index of how quickly the crystalline resin in the toner is melted and then diffused and compatible with the amorphous resin, and how quickly the viscosity of the amorphous resin can be lowered at a low temperature. Become. By satisfying the condition of (5) above, the low temperature fixability of the toner can be made higher.

As an embodiment of the toner of the present invention, it is preferable that the above conditions (6), (7) and (8) are further satisfied from the viewpoint that the effect of the present invention can be exhibited more highly.

In the embodiment of the toner of the present invention, from the viewpoint that the effect of the present invention can be exhibited more highly, the crystalline resin contains a crystalline polyester resin, and the weight average molecular weight of the crystalline polyester resin is within the range of 2000 to 25000. It is preferably in the range of 4000 to 10000, and more preferably in the range of 4000 to 10000. When the weight average molecular weight of the crystalline polyester resin is within the above range, the diffusion rate of the crystalline polyester resin into the amorphous resin can be kept within an appropriate range.

In the embodiment of the toner of the present invention, the content of the crystalline resin is within the range of 4 to 31 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint that the effect of the present invention can be exhibited higher. The content of the release agent is preferably in the range of 6 to 20 parts by mass with respect to 100 parts by mass of the binder resin. Further, it is more preferable that the content of the crystalline resin is in the range of 10 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

The method for producing a toner for developing an electrostatic charge image of the present invention is the method for producing the toner for developing an electrostatic charge image of the present invention, which comprises the first to third steps. It is characterized by manufacturing.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described in detail. In the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

[Toner for static charge image development]
The toner of the present invention contains toner matrix particles containing a binder resin and a mold release agent. The toner may contain an external additive attached to the surface of the toner matrix particles in addition to the toner matrix particles. The binder resin contained in the toner matrix particles contains an amorphous resin and a crystalline resin. The toner matrix particles have, for example, a form in which the domain of the crystalline resin and the domain of the release agent are dispersed in a matrix composed of an amorphous resin.

In the toner of the present invention, the rising temperature of the endothermic peak derived from the crystalline resin is T ₁ ° C., the endothermic peak temperature is T ₂ ° C., and the endothermic peak temperature is T 2 ° C. in the first heating process when the differential scanning calorimetry is performed on the toner. When the endothermic peak temperature derived from the mold release agent is T ₃ ° C., the following conditions (1), (2), (3) and (4) are satisfied.

(1) T ₁ is in the range of 57 to 62 ° C.
(2) T ₂ is in the range of 60 to 70 ° C.
(3) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 12 ° C
(4) T ₂ and T ₃ have the following relationship.
T ₂ <T ₃ ≤ T ₂ + 15 ° C

In the present invention, the DSC of the toner can be carried out according to JIS K 7121-1987. As the measuring device, a general DSC device can be used, and examples thereof include "Diamond DSC" (manufactured by PerkinElmer).

As a measurement procedure, 3.0 mg of a measurement sample (toner) is sealed in an aluminum pan (KITNO.B0143013) and set in a holder. The reference uses an empty aluminum pan. The measurement conditions are a measurement temperature of 0 ° C. to 100 ° C. and a temperature rise rate of 10 ° C./min. T ₁ , T ₂ and T ₃ are the temperatures (° C.) obtained as follows in the first temperature raising process. In the present specification, the endothermic peak derived from the crystalline resin and the endothermic peak derived from the mold release agent refer to the endothermic peak observed in the first heating process in the DSC of the toner.

T ₁ and T ₂ are temperatures related to the endothermic peak derived from the crystalline resin, and T ₃ is the temperature related to the endothermic peak derived from the release agent. Each endothermic peak can be specified based on elemental analysis of toner or the like. Alternatively, it can be specified by the melting point of the raw material component used for toner production. For example, when the melting point of the crystalline resin as a raw material component used for toner production is lower than the melting point of the release agent, the heat absorption peak derived from the crystalline resin is on the lower temperature side than the heat absorption peak derived from the release agent in the DSC curve of the toner. Measured at.

T ₁ is the rising temperature of the endothermic peak (melting peak) derived from the crystalline resin. The rising temperature of the heat absorption peak is generally defined as the external melting start temperature, and is drawn at the point where the gradient is maximized on the straight line extending the baseline on the low temperature side to the high temperature side and the curve on the low temperature side of the melting peak. The temperature at the intersection of tangents.

T ₂ and T ₃ are the endothermic peak temperature derived from the crystalline resin and the endothermic peak temperature derived from the release agent, respectively. The endothermic peak temperature (melting peak temperature) is a temperature generally regarded as the melting point, and is the temperature at the apex of the endothermic peak.

The effects of satisfying the conditions of (1), (2), (3) and (4) above are as described above. Regarding the condition (1), _{it is preferable that T 1} satisfies the following condition (6). Regarding the condition (2), _{it is preferable that T 2} satisfies the following condition (7). Further, regarding the condition (3), _{it is preferable that the relationship between T 1} and T ₂ satisfies the following condition (8). In the toner of the present invention, it is preferable that all the conditions (6) to (8) are satisfied.

(6) T ₁ is in the range of 60 to 61 ° C.
(7) T ₂ is in the range of 62 to 66 ° C.
(8) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 5 ° C

Further relates to the conditions of (4), the relationship between _{T 2} and _{T 3} preferably satisfies the condition _{as, T 3 ≦ T 2 + 10} ℃ relationship (9).

In addition to satisfying the above conditions (1) to (4), the toner of the present invention satisfies the following condition (5) when _{the outflow start temperature of the toner measured by the flow tester is T fb ° C.} It is preferable to satisfy.
(5) T ₂ and T _fb have the following relationship.
T ₂ ≤ T _fb ≤ T ₂ + 10 ° C

_{The measurement of the toner outflow start temperature T fb} by the flow tester in the present invention is performed, for example, as follows.

Specifically, first, in an environment of 20 ° C. and 50% RH, 1.1 g of the measurement sample (toner) was placed in a petri dish, flattened, left to stand for 12 hours or more, and then the molding machine "SSP-10A" ( (Manufactured by Shimadzu Corporation) ^{pressurizes with a force of 3820 kg / cm 2} for 30 seconds to prepare a cylindrical molded sample with a diameter of 1 cm. Next, this molded sample was raised in an environment of 24 ° C. and 50% RH by a flow tester "CFT-500D" (manufactured by Shimadzu Corporation) at a load of 196 N (20 kgf), a starting temperature of 45 ° C., and a preheating time of 300 seconds. Under the condition of a temperature rate of 6 ° C./min, it is extruded from a hole (1 mm diameter x 1 mm) of a cylindrical die using a piston with a diameter of 1 cm from the end of preheating, and an offset value of 5 mm is set by the melting temperature measurement method of the heating method. _Let the value measured in 1 be the outflow start temperature T fb.

_{When the relationship between T fb} and T ₂ measured in this way satisfies the condition (5) above, the low temperature fixability of the toner can be made higher. Regarding the condition (5), it is more preferable that _{the relationship between T fb} and T _{2 satisfies T fb} ≤ T ₂ + 5 ° C. as the condition (10).

The constituent components of the toner having the above characteristics will be described below.

<Toner matrix particles>
The toner matrix particles according to the toner of the present invention contain a binder resin and a mold release agent, and the binder resin contains an amorphous resin and a crystalline resin. The characteristics of the toner of the present invention according to the above conditions (1) to (10) are determined by the toner matrix particles. That is, the properties of the toner of the present invention according to the above conditions (1) to (10) are properties that are not affected by the external additive. Therefore, the characteristics of the toner of the present invention according to the above conditions (1) to (10) are the amorphous resin and crystalline resin as the binder resin contained in the toner matrix particles, and the type of the release agent. And the composition can be appropriately selected and adjusted by appropriately adjusting the production method.

The form of the toner matrix particles is not particularly limited, and examples thereof include a single-layer structure, a core-shell structure, and a multi-layer structure. In particular, from the viewpoint of ensuring heat-resistant storage, a core-shell structure is preferable. The core-shell structure specifically refers to a structure having core particles and a shell layer covering the core particles. Toner matrix particles having a core-shell structure are also hereinafter referred to as "core-shell particles". The shell layer is not limited to the one that completely covers the core particles, and the surface of the core particles may be partially exposed.

When the toner base particles are core-shell particles, it is preferable that the crystalline resin is contained in the core particles. More specifically, there is an embodiment in which the core particles contain a part of the amorphous resin, the crystalline resin and the release agent, and the shell layer is composed of the rest of the amorphous resin. The amorphous resin contained in the core particles and the amorphous resin constituting the shell layer may be the same or different.

The toner base particles may contain an internal additive such as a colorant and a charge control agent in addition to the binder resin and the mold release agent. When the toner matrix particles are core-shell particles, they are preferably added to the core particles.

[Bundling resin]
In the toner matrix particles according to the present invention, the binder resin contains an amorphous resin and a crystalline resin.

(Crystalline resin)
As the crystalline resin according to the present invention, conventionally known crystalline resins in the present technical field can be used. As the crystalline resin, a crystalline polyester resin is preferable. When the toner base particles are core-shell particles, the crystalline resin is preferably contained in the core particles.

The crystalline resin according to the present invention is a resin having a clear endothermic peak instead of a stepwise endothermic change in differential scanning calorimetry (DSC). A clear endothermic peak specifically means a peak in which the half width of the endothermic peak is within 15 ° C. in differential scanning calorimetry (DSC), for example, when measured at a heating rate of 10 ° C./min. do.

In the present invention, the melting point T _mp of the crystalline resin for use in the production of toner base particles is preferably in the range of 63 to 75 ° C., and more preferably in the range of 63 to 70 ° C.. When the melting point T _mp of the crystalline resin is within the above range, it is _{easy to adjust T 2} related to the obtained toner to the above range.

The melting point _Tmp of the crystalline resin is determined by, for example, the temperature of the peak of the melting peak (endothermic peak) from the DSC curve of the crystalline resin in the same manner as in obtaining _{T 2} from the DSC curve obtained by the DSC of the toner. Can be sought.

The crystalline resin used for producing the toner matrix particles is melted and recrystallized by, for example, heating and cooling operations when the toner matrix particles are produced. Therefore, the raw material crystalline resin and the crystalline resin in the toner matrix particles may have different DSC behaviors. In relation to the above conditions (1) to (10) in the toner of the present invention, T ₁ and T ₂ used are values based on the DSC behavior of the crystalline resin in the toner matrix particles.

The content of the crystalline resin in the binder resin is preferably 4 to 31 parts by mass, more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

When the content ratio of the crystalline resin is within the above range, an amount of crystalline resin capable of achieving low temperature fixability can be introduced into the toner base particles.

When the content ratio of the crystalline resin is less than the lower limit of the above range, low temperature fixability may not be sufficiently obtained. Further, when the content ratio of the crystalline resin is less than the lower limit of the above range, the compatibility with the non-crystalline resin is improved and the crystalline resin is difficult to crystallize, so that the glass transition point (Tg) of the toner matrix particles is lowered. This may make it difficult to ensure heat-resistant storage. The Tg of the toner matrix particles can be measured by the same method as the method for measuring the Tg of the amorphous resin (hereinafter, referred to as “Tg _{p”) described later.}

On the other hand, when the content ratio of the crystalline resin exceeds the upper limit of the above range, the temperature of the entire toner is difficult to rise due to a large amount of latent heat at the time of melting, which may deteriorate the fixability.

(Crystalline polyester resin)
The crystalline polyester resin is a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). It is a resin in the category.

In addition, in this specification, a polyester resin includes the meaning of both the one consisting of only polyester polymerized segments and the modified resin in which other components are bonded at a ratio of 50% by mass or less. As the other component to be bonded to the polyester polymerized segment, it is preferable to use a vinyl-based polymerized segment.

A polyvalent carboxylic acid is a compound containing two or more carboxy groups in one molecule. Examples of the polyvalent carboxylic acid for forming the crystalline polyester resin include saturated aliphatic dicarboxylic acids such as succinic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatics such as phthalic acid, isophthalic acid and terephthalic acid. Examples thereof include group dicarboxylic acids; trivalent or higher valent carboxylic acids such as trimellitic acid and pyromellitic acid; and anhydrides of these carboxylic acid compounds, or alkyl esters having 1 to 3 carbon atoms. These may be used individually by 1 type, and may be used in combination of 2 or more type.

A polyhydric alcohol is a compound containing two or more hydroxyl groups in one molecule. Examples of the polyhydric alcohol for forming the crystalline polyester resin include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-. Aliper diols such as xandiol, 1,7-heptandiol, 1,8-octanediol, neopentyl glycol, 1,4-butanediol; trivalent or higher such as glycerin, pentaerythritol, trimethylolpropane, sorbitol, etc. Examples include polyhydric alcohol. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Further, the crystalline polyester resin according to the present invention has a weight average molecular weight in the range of 2000 to 25000 from the viewpoint of keeping the diffusion rate of the crystalline polyester resin into the amorphous resin in an appropriate range as described above. It is preferably in the range of 4000 to 10000, and more preferably in the range of 4000 to 10000.

If the weight average molecular weight of the crystalline polyester resin is less than the lower limit of the above range, the compatibility with the amorphous resin becomes too high in the process of producing the toner matrix particles, and it becomes difficult to promote crystallization. it is difficult to raise up to T _2. Further, when the weight average molecular weight of the crystalline polyester resin exceeds the upper limit of the above range, the diffusion rate into the amorphous resin is greatly reduced, and it becomes difficult to quickly reduce the viscosity of the amorphous resin beyond _{T 2.} , Low temperature fixability is reduced.

In the present specification, the weight average molecular weight of the crystalline polyester resin is a value measured by gel permeation chromatography (GPC). The weight average molecular weight of the crystalline polyester resin by GPC can be measured by, for example, the following method.

Specifically, the apparatus "HLC-8120GPC" (manufactured by Tosoh Co., Ltd.) and the column "TSKguardgroup + TSKgelSuperHZ-M3 series" (manufactured by Tosoh Co., Ltd.) are used. Tetrahydrofuran (THF) as a carrier solvent is flowed at a flow rate of 0.2 mL / min while maintaining the column temperature at 40 ° C. The measurement sample (crystalline resin) is treated with an ultrasonic disperser at room temperature for 5 minutes. Under dissolution conditions, it is dissolved in tetrahydrofuran to a concentration of 1 mg / mL, and then treated with a membrane filter having a pore size of 0.2 μm. To obtain a sample solution. 10 μL of the sample solution was injected into the apparatus together with the carrier solvent, detected using a refractive index detector (RI detector), and the molecular weight distribution of the measurement sample was measured using monodisperse polystyrene standard particles. Calculated using a line. Ten points are used as polystyrene for calibration curve measurement.

(Amorphous resin)
The amorphous resin constituting the binder resin is composed of a main component in the binder resin, specifically, a component accounting for 50% by mass or more. The amorphous resin according to the present invention refers to a resin that does not show a clear endothermic peak in differential scanning calorimetry (DSC). The "clear endothermic peak" is as described for the crystalline resin. The content of the amorphous resin in the binder resin is preferably 70 to 96 parts by mass, more preferably 80 to 90 parts by mass with respect to 100 parts by mass of the binder resin.

When the content ratio of the amorphous resin is within the above range, sufficient fixability and sufficient heat-resistant storage property of the toner are sufficient when used as a binder resin together with a crystalline resin, particularly a crystalline polyester resin. And the heat resistance of the fixed image can be ensured.

The amorphous resin is not particularly limited. Specifically, vinyl resins such as styrene resin, acrylic resin, and styrene-acrylic copolymer resin (hereinafter, also referred to as "styrene acrylic resin"), amorphous polyester resin, and the like have fixability and heat resistance of the toner. From the viewpoint of storability and heat resistance of the fixed image, it is mentioned as suitable. Specifically, the styrene acrylic resin is a copolymer of a monomer containing a styrene-based monomer and a (meth) acrylic acid ester-based monomer. As used herein, "acrylic resin" includes methacrylic resin in its category. "(Meta) acrylic acid" means at least one of acrylic acid and methacrylic acid.

Further, as the amorphous resin, vinyl resins other than the above such as olefin resins, polyamide resins, polycarbonate resins, polyether resins, polyvinyl acetate resins, polysulfone resins, epoxy resins, polyurethane resins, urea resins and the like are used. You can also do it. The amorphous resin can be used alone or in combination of two or more.

Examples of the monomer for forming a vinyl resin such as a styrene resin, an acrylic resin, and a styrene acrylic resin include a vinyl monomer. As the vinyl monomer, the following can be used. As the vinyl monomer, one type can be used alone, or two or more types can be used in combination.

(1) Styrene-based monomer Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert -Butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene and derivatives thereof.

(2) (Meta) Acrylic Acid Ester-based Monomer: Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, T-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, phenyl (meth) acrylate, (meth) ) Diethylaminoethyl acrylate, dimethylaminoethyl (meth) acrylate and derivatives thereof.

(3) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc.

(4) Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc.

(5) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc.

(6) N-vinyl compounds N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone and the like.

(7) Others Vinyl compounds such as vinylnaphthalene and vinylpyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylnitrile and acrylamide.

Further, as the vinyl monomer, for example, it is preferable to use a vinyl monomer having an ionic dissociation group such as a carboxy group, a sulfonic acid group, and a phosphoric acid group. Specifically, there are the following.

Examples of the vinyl monomer having a carboxy group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, and itaconic acid monoalkyl ester. Examples of the vinyl monomer having a sulphonic acid group include styrene succinic acid, allyl succinic acid, 2-acrylamide-2-methylpropan succinic acid and the like. Further, examples of the vinyl monomer having a phosphoric acid group include acid phosphooxyethyl methacrylate.

Further, polyfunctional vinyls may be used as the vinyl monomer, and the vinyl resin may have a crosslinked structure. Examples of polyfunctional vinyls include divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, and neo. Examples include pentyl glycol diacrylate.

The amorphous polyester resin is a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). It is a resin in the category of resin.

Examples of the polyvalent carboxylic acid for forming the amorphous polyester resin include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, azelic acid, sebacic acid, 1,9-. Nonandicarboxylic acid, 1,10-decandicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecan Saturated aliphatic dicarboxylic acids such as dicarboxylic acid and 1,18-octadecanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid; maleic acid, fumaric acid, itaconic acid, citraconic acid and glutacon Unsaturated aliphatic dicarboxylic acids such as acids, isododecenyl succinic acid, n-dodecenyl succinic acid, n-octenyl succinic acid; trimellitic acid, pyromellitic acid, naphthalene tricarboxylic acid, naphthalene tetracarboxylic acid, pyrene tricarboxylic acid, pyrene tetra Examples thereof include trivalent or higher-valent polyvalent carboxylic acids such as carboxylic acids. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the polyhydric alcohol for forming the amorphous polyester resin include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1, , 7-Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1, , 14-Tetradecanediol, 1,18-octadecandiol, 1,20-eicosanediol and other aliphatic diols; bisphenol A, bisphenol F and other bisphenols, and their ethylene oxide adducts, propylene oxide adducts and the like. Alkylene oxide adducts of bisphenols; trivalent or higher valent polyols such as glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, tetraethylol benzoguanamine and the like can be mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The glass transition point (Tg _p ) of the amorphous resin is preferably about 30 to 50 ° C. as the Tg of the raw material amorphous resin used for the toner matrix particles. By tg _p is within the above range, the low temperature fixability of the resulting toner is ensured.

In the present invention, the glass transition point of the amorphous resin (Tg _p) is a value measured using "Diamond DSC" (manufactured by Perkin Elmer). As a measurement procedure, 3.0 mg of a measurement sample (amorphous resin) is sealed in an aluminum pan and set in a holder. The reference uses an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 100 ° C., a temperature rise rate of 10 ° C./min, and a temperature decrease rate of 10 ° C./min, and the temperature was controlled by Heat-cool-Heat. The analysis is performed based on the data (DSC curve) in Heat. The first inflection point in the DSC curve is defined as the glass transition point (Tg).

The molecular weight measured by gel permeation chromatography (GPC) of the amorphous resin is preferably 1000 to 50000 in terms of weight average molecular weight (Mw), and more preferably 2500 to 35000. The number average molecular weight (Mn) is preferably 5000 to 20000, more preferably 6500 to 12000.

When the molecular weight of the amorphous resin is in the above range, low-temperature fixability and fixing separability can be surely obtained. When the molecular weight of the amorphous resin exceeds the upper limit of the above range, low temperature fixability may not be sufficiently obtained. On the other hand, when the molecular weight of the amorphous resin is less than the lower limit of the above range, the fixing separability may not be sufficiently obtained.

The molecular weight measured by gel permeation chromatography (GPC) of the amorphous resin is measured in the same manner as in the case of the crystalline polyester resin except that the amorphous resin is used as the measurement sample. Is.

When the toner base particles are core-shell particles, the composition of the binder resin is as described above, the core particles contain a part of the amorphous resin and the crystalline resin, and the shell layer is the rest of the amorphous resin. An aspect composed of is mentioned. The amorphous resin constituting the core particles and the amorphous resin constituting the shell layer may be the same or different.

Among the above, vinyl resin is preferable, and styrene acrylic resin is preferable, as the amorphous resin constituting the core particles. Further, as the resin constituting the shell layer, an amorphous resin is preferable, an amorphous polyester resin, a vinyl resin and the like are more preferable, and an amorphous polyester resin is particularly preferable.

When the toner matrix particles are core-shell particles, the content ratio of the resin constituting the shell layer is preferably 5 to 30% by mass with respect to the total amount of the binder resin contained in the toner matrix particles.

〔Release agent〕
The toner matrix particles according to the present invention contain a mold release agent in order to ensure the fixing and separating property of the toner. When the toner base particles are core-shell particles, the release agent is preferably contained in the core particles.

The release agent used for producing the toner matrix particles is composed of, for example, wax and has a melting point. Melting point T _mw of the releasing agent used in the production of the toner base particles is preferably in the range of 70 to 95 ° C., and more preferably in the range of 75-85 ° C.. When the melting point T _mw of the release agent is within the above range, _{the relationship between T 3} and T ₂ in the obtained toner can easily satisfy the above condition (4). Further, in the toner obtained, in order to satisfy the above condition (4), the melting point T _mw of the release agent is preferably higher than the melting point T _mp of the crystalline resin.

The melting point T _mw of the release agent is determined by, for example, the temperature of the peak of the melting peak (heat absorption peak) from the DSC curve of the release agent in the same manner as in obtaining _{T 3} from the DSC curve obtained by the DSC of the toner. Can be sought. Note that T ₃ is a value based on the DSC behavior of the release agent in the toner matrix particles. Specifically, T ₃ is the endothermic peak temperature derived from the release agent obtained from the DSC curve of the toner. Therefore, the melting points T _mw and T ₃ of the release agent may be different.

As the release agent, an ester wax or a hydrocarbon wax can be used. As such a wax, a synthetic wax may be used, or a commercially available wax may be purified and used. Examples of the purification method include a method of dissolving in n-hexane or heptane and recrystallizing. Further, these release agents may be used alone or in combination of two or more.

Ester waxes include carnauba wax, montan wax, behenic acid behenate, trimellitic propantribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecan. Examples thereof include diol distearate, tristearyl trimellitic acid, and distealyl maleate.

Examples of the hydrocarbon wax include polyolefin waxes such as polyethylene wax and polypropylene wax, petroleum-derived paraffin wax, microcrystalline wax, and synthetic waxes such as Fishertroph wax and polyethylene wax.

The content ratio of the release agent is preferably 1 to 20 parts by mass, and more preferably 5 to 12 parts by mass with respect to 100 parts by mass of the binder resin in the toner base particles. When the content ratio of the release agent in the toner base particles is within the above range, separability and fixability can be surely obtained at the same time.

[Colorant]
The toner base particles may contain a colorant as an optional component. When the toner base particles are core-shell particles, the colorant is preferably contained in the core particles. When the toner matrix particles are configured to contain a colorant, various known colorants such as carbon black, black iron oxide, dyes, and pigments can be used as the colorant.

Examples of carbon black include channel black, furnace black, acetylene black, thermal black, lamp black, and the like, and examples of black iron oxide include magnetite, hematite, and titanium trioxide.

Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Examples thereof include Solvent Blue 25, 36, 60, 70, 93, and 95.

Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 150, 166, 177, 178, 222, 238, 269, C.I. I. Pigment Orange 31, 43, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 156, 158, 180, 185, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, 60 and so on.

The colorant for obtaining the toner of each color may be used alone or in combination of two or more for each color.

The content ratio of the colorant is preferably 1 to 10 parts by mass, and more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the binder resin in the toner base particles. If the content of the colorant is less than the lower limit of the above range, the obtained toner may not have the desired coloring power, while if the content of the colorant exceeds the upper limit of the above range, coloring may not be obtained. Release of the agent or adhesion to carriers may occur, which may affect the chargeability.

[Charge control agent]
In addition, the toner matrix particles according to the present invention may contain a charge control agent, if necessary.

The charge control agent is not particularly limited as long as it is a substance capable of giving positive or negative charge by triboelectric charging, and various known positive charge control agents and negative charge control agents can be used.
The content of the charge control agent is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

<External agent>
In the toner of the present invention, the toner matrix particles may be used as they are as the toner, or may be used by adhering an external additive to the surface of the toner matrix particles. The external additive is used to improve fluidity, chargeability, cleanability and the like. Examples of the external additive include known fine particles such as inorganic fine particles and organic fine particles, and lubricants. Various combinations of external additives may be used.

As the inorganic fine particles, inorganic fine particles made of silica, titania (titanium oxide), alumina, strontium titanate, zinc titanate, calcium titanate and the like are preferable. These may be a combination of two or more types. The number average primary particle size of the inorganic fine particles is preferably about 10 to 100 nm. For the number average primary particle size of the inorganic fine particles, for example, for an image photographed using a scanning electron microscope (SEM), 100 horizontal ferret diameters are calculated by an image processing analyzer or the like, and the average value is obtained. It can be measured by the method.

These inorganic fine particles may be hydrophobized by surface modification, if necessary. By using the hydrophobicized inorganic fine particles, for example, it is possible to suppress the adhesion between the white toner matrix particles (Am) due to water adsorption generated due to the hydroxy group existing on the surface of the inorganic oxide particles. ..

Examples of the surface modifier used for surface-modifying the inorganic fine particles include a silane coupling agent and a titanium coupling agent. As the silane coupling agent, dimethyldimethoxysilane, hexamethyldisilazane (HMDS), methyltrimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane and the like are preferable. Further, higher fatty acids and silicone oils can also be used as the surface modifier. Silicone oils include cyclic compounds such as organosiloxane oligomers, octamethylcyclotetrasiloxanes, decamethylcyclopentasiloxanes, tetramethylcyclotetrasiloxanes, and tetravinyltetramethylcyclotetrasiloxanes, and linear or branched organosiloxanes. Can be used.

The amount of the external additive added is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner base particles.

<Toner form>
The toner of the present invention preferably has the following average particle size and average circularity. Generally, the average particle size and the average circularity of the toner may be treated as the same as the average particle size and the average circularity of the toner matrix particles. That is, even when the toner of the present invention contains an external additive, the effect of adding the external additive on the particle size and circularity of the toner matrix particles is as small as the range of measurement error. Is.

[Average particle size of toner]
In the toner of the present invention, the average particle size is preferably, for example, 3 to 10 μm in terms of volume-based median diameter, and more preferably 5 to 8 μm. The average particle size of the toner can be controlled by the production conditions. For example, when the toner matrix particles are produced by the emulsion polymerization agglutination method described later, it can be controlled by the concentration of the agglutinant used at the time of production, the amount of the organic solvent added, the fusion time, the composition of the binder resin, and the like.

When the volume-based median diameter is within the above range, it is possible to faithfully reproduce a very minute dot image of 1200 dpi level.

The toner volume-based median diameter is measured and calculated using a measuring device that connects a computer system equipped with data processing software "Software V3.51" to "Multisizer 3" (manufactured by Beckman Coulter). It is a thing.

Specifically, 0.02 g of the measurement sample (toner) is 20 mL of a surfactant solution (for the purpose of dispersing the toner, for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water. ), Then ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is placed in a beaker containing "ISOTONII" (manufactured by Beckman Coulter) in a sample stand. , Inject with a pipette until the indicated concentration on the measuring device reaches 8%. Here, by setting this concentration range, it is possible to obtain a reproducible measured value. Then, in the measuring device, the number of measured particles is 25,000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the measurement range of 2 to 60 μm into 256, and the volume integration fraction is 50 from the largest. The particle size of% is defined as the volume-based median diameter.

[Average circularity of toner]
In the toner of the present invention, the average circularity is preferably 0.930 to 1.000, more preferably 0.950 to 0.995, from the viewpoint of stability of charging characteristics and low temperature fixability. ..

When the average circularity is in the above range, individual particles of the toner are less likely to be crushed, contamination of the triboelectric charging member is suppressed, the chargeability of the toner is stabilized, and the image quality of the formed image is improved. It will be expensive.

The average circularity of the toner is a value measured using "FPIA-3000" (manufactured by Sysmex Corporation). Specifically, the measurement sample (toner) is blended with an aqueous solution containing a surfactant, ultrasonically dispersed for 1 minute to disperse the particles, and then measured under the measurement conditions HPF by "FPIA-3000" (manufactured by Sysmex). In the (high-magnification imaging) mode, imaging is performed at an appropriate density of 3,000 to 10,000 HPF detections, the circularity of each particle is calculated according to the following formula (y), and the circularity of each particle is determined. It is a value calculated by adding and dividing by the total number of particles. If the number of HPFs detected is in the above range, reproducibility can be obtained.
Equation (y): Circularity = (perimeter of a circle having the same projected area as the particle image) / (perimeter of the projected particle image)

[Developer]
The toner of the present invention may be used alone as a magnetic or non-magnetic one-component developer, or may be used as a two-component developer containing the toner of the present invention and a carrier. The two-component developer can be obtained, for example, by mixing the toner of the present invention with a carrier. The mixing device used at the time of mixing is not particularly limited, and examples thereof include a Nauter mixer, a W cone, and a V-type mixer. The toner content (toner concentration) in the two-component developer is not particularly limited, but is preferably 4.0 to 8.0% by mass.

When the toner is used as a two-component developer, the carrier is a magnetic particle made of a conventionally known material such as a metal such as iron, ferrite or magnetite, or an alloy between the metal and a metal such as aluminum or lead. It can be used, and ferrite particles are particularly preferable. Further, as the carrier, a coat carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, a dispersed carrier in which the magnetic fine powder is dispersed in a binder resin, or the like may be used.

The volume-based median diameter of the carrier is preferably 20 to 100 μm, more preferably 25 to 80 μm. The volume-based median diameter of the carrier can be typically measured by a laser diffraction type particle size distribution measuring device "HELOS" (manufactured by Sympathetic Co., Ltd.) equipped with a wet disperser.

[Toner manufacturing method]
The method for producing the toner of the present invention is not particularly limited as long as the obtained toner is produced so as to satisfy the above conditions (1) to (4).

The toner matrix particles can be produced by, for example, a pulverization method, an emulsion dispersion method, a suspension polymerization method, a dispersion polymerization method, an emulsion polymerization method, an emulsion polymerization aggregation method, or another known method. In particular, the emulsion polymerization agglutination method is preferable from the viewpoint of stably providing the production conditions that can satisfy the conditions (1) to (4) in the production cost and the obtained toner. When the toner contains an external additive, the toner is obtained by adhering the external additive to the surface of the toner matrix particles.

In the emulsion aggregation method, an aqueous dispersion of binder resin fine particles (hereinafter, also referred to as “binding resin fine particles”) dispersed by a surfactant or a dispersion stabilizer is dispersed in the toner matrix particles. Liquid, in the present invention, is mixed with an aqueous dispersion of fine particles of a mold release agent and an aqueous dispersion of fine particles of various components as optional components, and a coagulant is added to obtain a desired particle size of the toner base particles. This is a method of forming toner matrix particles by aggregating up to, and then or at the same time as aggregating, fusing between the binder resin fine particles and controlling the shape.

Here, the "aqueous dispersion liquid" means that the dispersion (particles) is dispersed in the aqueous medium, and the aqueous medium means that the main component (50% by mass or more) is composed of water. .. Examples of components other than water include organic solvents that are soluble in water, and examples thereof include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Of these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are particularly preferable.

The binder resin fine particles may have a multilayer structure of two or more layers made of binder resins having different compositions, and the binder resin fine particles having such a structure are, for example, those having a two-layer structure. A dispersion liquid of resin fine particles is prepared by a polymerization treatment (first stage polymerization) according to a conventional method, a polymerization initiator and a polymerizable monomer are added to the dispersion liquid, and this system is subjected to a polymerization treatment (second stage polymerization). It can be obtained by a method of polymerization).

In the method for producing a toner of the present invention, a specific example of producing toner matrix particles by an emulsion polymerization aggregation method is a method for producing toner matrix particles by a method including the following first to third steps. Can be mentioned.
First step; Step of obtaining a dispersion liquid containing a toner matrix particle precursor by heating and stirring the fine particles containing the binder resin and the mold release agent in an aqueous medium to agglomerate and fuse them. Step of cooling the dispersion heated in the first step to a temperature of 30 ° C. or lower at a temperature lowering rate of 6 ° C./min or more Third step; 57. Step to maintain at a temperature in the range of ~ 62 ° C for 30 minutes or more

In this way, the toner matrix particles are formed by the first step to the third step. After that, the toner matrix particles are taken out from the dispersion liquid by, for example, a filtration / washing step, and dried by a drying step. Further, if necessary, the external additive is added to the surface of the toner matrix particles by the addition step of the external additive. Hereinafter, each step will be described.

(First step)
The first steps are (a) a step of preparing an aqueous dispersion of fine particles of various components constituting the toner base particles (hereinafter, also referred to as “preparation of an aqueous dispersion”), and (b) in an aqueous medium. In the above, the step of forming a toner base particle precursor by aggregating and fusing fine particles of various components (hereinafter, also referred to as “aggregation / fusion step”) is included.

The toner of the present invention contains a binder resin containing an amorphous resin and a crystalline resin, and a mold release agent. In the step (a), an aqueous dispersion of amorphous resin fine particles (hereinafter, also referred to as “amorphous resin fine particles”) and crystalline resin fine particles (hereinafter, also referred to as “crystalline resin fine particles”). The aqueous dispersion of the above and the fine particles of the mold release agent (hereinafter, also referred to as “fine particles of the mold release agent”) can be prepared and subjected to the next aggregation / fusion step (b).

As will be described below, when the amorphous resin fine particles are produced, it is possible to include a release agent in the amorphous resin fine particles, and it is preferable to do so. In that case, the preparation of the aqueous dispersion of the release agent fine particles can be omitted. Here, the "fine particles containing the binder resin and the mold release agent" referred to in the first step means the fine particles of the binder resin as an aggregate of the fine particles (in the present invention, the fine particles of the amorphous resin and the crystalline property). Fine particles containing both resin fine particles and a mold release agent, and fine particles containing both a binder resin (for example, an amorphous resin) and a mold release agent (in the present invention, further crystalline). Any case containing resin fine particles) is included in the category.

When the toner matrix particles according to the present invention contain a colorant, in step (a), in addition to the above-mentioned aqueous dispersions, an aqueous dispersion of colorant fine particles is separately prepared and used. It is preferable to use it in the aggregation / fusion step of (b).

(A) Preparation step of aqueous dispersion liquid [Preparation step of aqueous dispersion liquid of amorphous resin fine particles]
In this step, an aqueous dispersion of amorphous resin fine particles made of amorphous resin is prepared. When the amorphous resin is a vinyl resin such as a styrene acrylic resin, the aqueous dispersion of the amorphous resin fine particles uses a vinyl monomer for obtaining the amorphous resin and has a miniemulsion weight. It can be prepared legally. That is, for example, a vinyl monomer is added to an aqueous medium containing a surfactant, mechanical energy is applied to form droplets, and then the droplets are generated by radicals from a water-soluble radical polymerization initiator. The polymerization reaction is allowed to proceed inside. An oil-soluble polymerization initiator may be contained in the droplets.

(Surfactant)
As the surfactant used in this step, various conventionally known anionic surfactants, cationic surfactants, nonionic surfactants and the like can be used.

(Polymerization initiator)
As the polymerization initiator used in this step, various conventionally known polymerization initiators can be used. As a specific example of the polymerization initiator, for example, a persulfate (potassium persulfate, ammonium persulfate, etc.) is preferably used. In addition, azo compounds (4,4'-azobis4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salts, etc.), peroxide compounds, azobisisobutyronitrile, etc. are used. May be good.

(Chain transfer agent)
In this step, a commonly used chain transfer agent can be used for the purpose of adjusting the molecular weight of the amorphous resin. The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as 2-chloroethanol, octyl mercaptan, dodecyl mercaptan, and t-dodecyl mercaptan, and styrene dimers.

Further, the aqueous dispersion of the amorphous resin fine particles synthesizes an amorphous polyester resin, for example, when the amorphous resin is an amorphous polyester resin, and puts the amorphous polyester resin in an aqueous medium. It can be prepared by dispersing it in the form of fine particles. Specifically, an amorphous polyester resin is dissolved or dispersed in an organic solvent to prepare an oil phase liquid, and the oil phase liquid is dispersed in an aqueous medium by phase inversion emulsification or the like to obtain a desired particle size. It can be prepared by removing the organic solvent after forming oil droplets in a controlled state.

The amount of the aqueous medium used is preferably 50 to 2000 parts by mass, more preferably 100 to 1000 parts by mass with respect to 100 parts by mass of the oil phase liquid. A surfactant or the like may be added to the aqueous medium for the purpose of improving the dispersion stability of oil droplets. Examples of the surfactant include those similar to those listed in the above steps.

As the organic solvent used for preparing the oil phase liquid, one having a low boiling point and low solubility in water is preferable from the viewpoint of easy removal treatment after formation of oil droplets, and specifically, For example, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene and the like can be mentioned. These can be used alone or in combination of two or more. The amount of the organic solvent used is usually 1 to 300 parts by mass with respect to 100 parts by mass of the amorphous polyester resin. The emulsification and dispersion of the oil phase liquid can be performed by utilizing mechanical energy.

A mold release agent is contained in the toner matrix particles according to the present invention, and the mold release agent is, for example, a solution of a vinyl monomer for forming a vinyl resin or a non-release agent in advance in this step. It can be introduced into the toner matrix particles by dissolving or dispersing it in the oil phase liquid of the crystalline polyester resin.

For example, when a non-crystalline resin fine particles having a three-layer structure made of vinyl resin are produced by three-step polymerization of first-stage polymerization, second-stage polymerization, and third-stage polymerization, a polymerization solution is produced during the second-stage polymerization. By carrying out polymerization by containing a mold release agent together with a polymerizable monomer for obtaining a vinyl resin, amorphous resin fine particles containing the mold release agent can be obtained. Then, the aqueous dispersion of the amorphous resin fine particles containing the release agent is used in the aggregation / fusion step of (b).

Further, as the release agent, a dispersion liquid of the release agent fine particles composed of only the release agent is separately prepared, and the release is performed together with the amorphous resin fine particles and the crystalline resin fine particles in the aggregation / fusion step of (b). Although it is possible to introduce the agent fine particles into the toner matrix particles by aggregating the agent fine particles, it is preferable to adopt a method of introducing the agent fine particles in advance in this step.

In addition, other internal additives such as a charge control agent, which are contained in the toner matrix particles according to the present invention as needed, are, for example, vinyl for forming an amorphous resin in advance in this step. It can be introduced into the toner matrix particles by dissolving or dispersing it in a monomer solution (or an oil phase solution of an amorphous polyester resin).

For such an internalizing agent, a dispersion liquid of the internalizing agent fine particles consisting of only the internalizing agent is separately prepared, and in the coagulation / fusion step, the dispersion liquid is contained together with the amorphous resin fine particles, the crystalline polyester resin fine particles and the coloring agent fine particles. Although it can be introduced into the toner base particles by aggregating the additive fine particles, it is preferable to adopt a method of introducing the additive fine particles in advance in this step.

The average particle size of the amorphous resin fine particles is preferably in the range of 100 to 400 nm in terms of volume-based median diameter. In the present invention, the volume-based median diameter of the amorphous resin fine particles is a value measured using "Microtrack UPA-150" (manufactured by Nikkiso Co., Ltd.).

[Preparation process of aqueous dispersion of crystalline resin fine particles]
In this step, an aqueous dispersion of crystalline resin fine particles made of crystalline resin is prepared. As the crystalline resin, a crystalline polyester resin is preferable.

The aqueous dispersion of the crystalline resin fine particles can be prepared by synthesizing the crystalline resin and dispersing the crystalline resin in the aqueous medium in the form of fine particles. Specifically, a crystalline resin is dissolved or dispersed in an organic solvent to prepare an oil phase liquid, and the oil phase liquid is dispersed in an aqueous medium by phase inversion emulsification or the like to control the desired particle size. It can be prepared by removing the organic solvent after forming oil droplets in a fresh state.

The amount of the aqueous medium used is preferably 50 to 2000 parts by mass, more preferably 100 to 1000 parts by mass with respect to 100 parts by mass of the oil phase liquid. A surfactant or the like may be added to the aqueous medium for the purpose of improving the dispersion stability of oil droplets. Examples of the surfactant include those similar to those listed in the above steps.

As the organic solvent used for preparing the oil phase liquid, one having a low boiling point and low solubility in water is preferable from the viewpoint of easy removal treatment after formation of oil droplets, and specifically, For example, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene and the like can be mentioned. These can be used alone or in combination of two or more. The amount of the organic solvent used is usually 1 to 300 parts by mass with respect to 100 parts by mass of the crystalline resin. The emulsification and dispersion of the oil phase liquid can be performed by utilizing mechanical energy.

The average particle size of the crystalline resin fine particles is preferably in the range of 100 to 400 nm in terms of volume-based median diameter. In the present invention, the volume-based median diameter of the crystalline resin fine particles is a value measured using "Microtrack UPA-150" (manufactured by Nikkiso Co., Ltd.).

[Preparation process of aqueous dispersion of colorant fine particles]
This step is a step performed as necessary when it is desired that the toner base particles contain a colorant, and the colorant is dispersed in an aqueous medium in the form of fine particles to obtain an aqueous dispersion of the colorant fine particles. This is the process of preparation.

The aqueous dispersion of the colorant fine particles is obtained by dispersing the colorant in an aqueous medium in which the surfactant is added at a critical micelle concentration (CMC) or higher. The colorant can be dispersed by using mechanical energy, and the disperser to be used is not particularly limited, but preferably an ultrasonic disperser, a mechanical homogenizer, a manton golin, a pressure homogenizer, or the like is added. Examples include medium-type dispersers such as pressure dispersers, sand grinders, Getzman mills, and diamond fine mills.

The volume-based median diameter of the colorant fine particles is preferably 10 to 300 nm, more preferably 100 to 200 nm, and particularly preferably 100 to 150 nm in a dispersed state. In the present invention, the volume-based median diameter of the colorant fine particles is a value measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

(B) Aggregation / Fusion Step In this step, amorphous resin fine particles, crystalline resin fine particles, mold release agent fine particles, and, if necessary, other toner constituents, for example, colorant fine particles were dispersed. In an aqueous medium, these fine particles are agglomerated and further fused by heating. In the above, when the amorphous resin fine particles contain a release agent, the release agent fine particles may not be present in the aqueous medium.

Specifically, in the aggregation / fusion step, a coagulant having a critical aggregation concentration or higher is added to an aqueous dispersion in which the above fine particles are dispersed in an aqueous medium, and a glass transition point (Tg) of an amorphous resin is added. _By heating to a temperature of p) or higher, the fine particles are aggregated and fused. As a result, a toner matrix particle precursor is formed.

The heating temperature in the agglutination / fusion step _{may be Tg p} or higher, _{but is preferably (Tg p} + 10 ° C.) to (Tg _p + 50 ° C.), and particularly preferably (Tg _p + 15 ° C.) to (Tg _p +40 ° C.). ℃). The heating temperature in the agglutination and fusion steps _{is preferably equal to} or higher than the melting point of the crystalline resin, T mp. Further, the heating temperature in the agglutination and fusion steps is preferably set to _{the melting point T mw or more of the release agent.} By setting the heating temperature in the agglutination and fusion steps as described above, it becomes easier to achieve the conditions (1) to (4) in the obtained toner.

[Coagulant]
The coagulant used in this step is not particularly limited, but one selected from metal salts such as alkali metal salts and alkaline earth metal salts is preferably used. Examples of the metal salt include monovalent metal salts such as sodium, potassium and lithium; divalent metal salts such as calcium, magnesium, manganese and copper; and trivalent metal salts such as iron and aluminum. Specific metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc., among which agglomerates in a smaller amount. It is particularly preferable to use a divalent metal salt because the above can be promoted. These can be used alone or in combination of two or more.

When the toner base particles have a core-shell structure, for example, in this step, the amorphous resin fine particles, the crystalline resin fine particles, and the release agent fine particles (however, the amorphous resin fine particles contain the release agent). In this case, the release agent fine particles may not be present.), Arbitrary colorant fine particles are aggregated and fused to form core particles, and then shell resin fine particles for forming a shell layer are used as core particles. It can be formed by aggregating and fusing. The shell resin is preferably an amorphous resin.

The first step may further include an aging step, if necessary. The aging step is a step of aging the toner matrix particle precursor obtained by the agglutination / fusion step (b) until it has a desired shape by thermal energy. Specifically, the aging treatment involves heating and stirring a system in which the toner matrix particle precursor is dispersed until the shape of the toner matrix particle precursor becomes a desired circularity, and the heating temperature, stirring rate, and heating time are adjusted. It is done by adjusting by such as.

The heating temperature is, for example, it is preferable that the glass transition point _(Tg p) + _30~40 ℃ about noncrystalline resin. As a result, the viscosity of the binder resin can be significantly reduced, and the time required for adjusting the shape of the toner matrix particles can be shortened. Further, it is preferable to heat the material above the melting point of the crystalline resin and the mold release agent contained in the toner base particles. As a result, the amorphous resin is plasticized by the crystalline resin, and the viscosity of the binder resin is significantly reduced, so that the time required for adjusting the shape of the toner base particles can be shortened.

(Second step)
The second step is a step of cooling the dispersion liquid of the toner base particle precursor obtained in the first step. As a condition of the cooling treatment, the temperature is cooled to a temperature of 30 ° C. or lower at a temperature lowering rate of 6 ° C./min or more. The temperature lowering rate is preferably 10 ° C./min or higher. From the viewpoint of operability, the upper limit of the temperature lowering rate is about 20 ° C./min. The temperature after cooling is preferably 25 ° C. or lower.

When the dispersion liquid of the toner matrix particle precursor is cooled at a temperature lowering rate of 6 ° C./min or more to crystallize the crystalline resin melted in the toner matrix particle precursor and the crystalline component such as the mold release agent. By increasing the supercooled state, crystal nucleation can be promoted. By generating a large number of crystal nuclei, it becomes possible to generate a large number of small crystals in the crystallization step, which has the effect of facilitating control of the melting point distribution. Further, by setting the temperature after cooling to 30 ° C. or lower, the above effect can be sufficiently obtained.

The specific method of the cooling treatment is not particularly limited, and examples thereof include a method of introducing a refrigerant from the outside of the reaction vessel for cooling, a method of directly pouring cold water into the reaction system for cooling, and the like. can.

(Third step)
The third step is a step of maintaining the dispersion liquid of the toner matrix particle precursor cooled in the second step at a temperature in the range of 57 to 62 ° C. for 30 minutes or more. By going through the third step, the crystallization of the crystalline resin in the toner matrix particle precursor is promoted, and the toner matrix particles in the toner of the present invention can be obtained. _{That is, T 1} and T ₂ of the obtained toner base particles are determined by the heating temperature and heating time in the third step.

As described above, T ₁ i.e. of the toner, T ₁ of the toner base particles closely related to the temperature of the heat-resistant storage stability. Specifically, for example, when trying to secure heat-resistant storage property of about 57 ° C., it is necessary to eliminate low melting point crystals having a melting point of less than 57 ° C. from the toner. In this case, in the method of the present invention, the dispersion liquid of the toner matrix particle precursor containing the uncrystallized crystalline resin after the second step is heat-treated at a temperature of 57 ° C. to be less than 57 ° C. The low melting point crystals of the above are melted and the crystalline resin is recrystallized. The crystalline resin in the toner matrix particles thus obtained is changed to crystals in which the rising temperature of the endothermic peak is approximately 57 ° C.

Thus, in the manufacturing method of the toner of the present invention, the heating temperature in the third step was the condition temperature range 57 to 62 ° C. of T ₁ which is the (1) in the toner of the present invention and the same temperature. The heating temperature in the third step is preferably a condition temperature range 61-62 ° C. of T ₁ which is above (6) in the toner of the present invention. By _{setting the temperature of T 1} to 57 ° C or higher, the heat-resistant storage property of the toner can be sufficiently ensured, and by setting it to 62 ° C or lower, the timing at which the crystalline resin starts to melt is set to a moderately low temperature, so that the toner can be stored. Low temperature fixability can be guaranteed.

Furthermore, with regard the temperature of T ₂ is an endothermic peak temperature (melting point) of the crystalline resin in the toner base particles, T ₂ by the heating temperature and the temperature range 57 to 62 ° C. of T ₁ in the third step It is possible to control the range of 60 to 70 ° C, _{and by setting the temperature of T 2} to 60 ° C or higher, the heat-resistant storage property of the toner can be sufficiently ensured, and by setting it to 70 ° C or lower, the low-temperature fixability of the toner can be sufficiently ensured. Can be guaranteed.

The heating time in the third step is 30 minutes or more from the viewpoint of sufficiently melting the low melting point crystals and promoting recrystallization, preferably in the range of 1 to 5 hours, and more preferably in the range of 1 to 3 hours. ..

When the dispersion liquid of the toner matrix particle precursor after the second step is raised to the heating temperature in the third step, the aggregation of the toners generated when the heat is suddenly applied is suppressed. From this point of view, for example, it is preferable to carry out the test under the condition of a temperature rising rate of 6 ° C./min or more and 30 ° C./min or less.

Further, the third step may be performed in two or more steps. In that case, the heating temperature is raised as the stage progresses, and the heating temperature at the final stage is set to the temperature of 57 to 62 ° C. above. Regarding the heating time, the heating time at the final stage is set to 30 minutes or more. For example, when performing a two-step heat treatment, the first heating is performed in a temperature range of 40 to 55 ° C. for 1 to 10 hours, and then the final heating is performed in a temperature range of 57 to 62 ° C. for 30 minutes or more. Is preferable. It is preferable from the viewpoint of adjusting the crystallinity and adjusting the melting start temperature (endothermic peak rising temperature) (T _{1) of the crystalline resin by performing the heat treatment in two or more steps.}

By controlling the time and temperature of the heat treatment in the third step in this way, it is possible to control the melting point distribution of the crystalline resin in the toner matrix particles and achieve both low-temperature fixability and heat-resistant storage. ..

The method for cooling the dispersion liquid of the toner matrix particles after the third step is not particularly limited. Slow cooling may be performed, but from the viewpoint of production efficiency, it is preferable to perform the cooling at a temperature lowering rate of, for example, 6 ° C./min or more.

(Filtration / cleaning process)
In this step, the toner matrix particles are solid-liquid separated from the cooled toner matrix particles after the third step, and the toner cake obtained by the solid-liquid separation (the toner matrix particles in a wet state is caked). This is a step of removing deposits such as a surfactant and a coagulant from an aggregate (aggregated into a shape) and cleaning.

The solid-liquid separation is not particularly limited, and a centrifugal separation method, a vacuum filtration method using a nutche or the like, a filtration method using a filter press or the like can be used. Further, in washing, it is preferable to wash with water until the electric conductivity of the filtrate becomes 10 μS / cm or less.

(Drying process)
This step is a step of drying the washed toner cake, and can be performed according to a drying step in a generally known method for producing toner matrix particles.

Specifically, examples of the dryer used for drying the toner cake include a spray dryer, a vacuum freeze dryer, a vacuum dryer, and the like, such as a static shelf dryer, a mobile shelf dryer, and a fluidized layer. It is preferable to use a dryer, a rotary dryer, a stirring dryer, or the like.

The water content of the dried toner matrix particles is preferably 5% by mass or less, more preferably 2% by mass or less. When the dried toner matrix particles are agglutinated by a weak inter-particle attractive force, the agglomerates may be crushed. Here, as the crushing processing device, a mechanical crushing device such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(Addition process of external additive)
This step is a step performed as necessary when adding an external additive to the toner matrix particles. The above-mentioned toner matrix particles can be used as they are as toner, but in order to improve fluidity, chargeability, cleaning property, etc., the toner matrix particles are added with an external agent such as a so-called fluidizing agent or cleaning aid. May be used in the state of adding. As the external additive, the above-mentioned various agents may be used in combination. The amount of these external additives added is as described above.

As the mixing device used for adding the external additive to the surface of the toner matrix particles, a mechanical mixing device such as a Henschel mixer or a coffee mill can be used.

Although the embodiments of the present invention have been specifically described above, the embodiments of the present invention are not limited to the above examples, and various modifications can be made.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, the indication of "parts" or "%" is used, but unless otherwise specified, it indicates "parts by mass" or "% by mass". The physical characteristics of each component are those measured by the above method unless otherwise specified.

<Example 1: Manufacture of toner 1>
Toner matrix particles, which are core-shell particles, and toner 1 having an external additive on the surface thereof were produced as follows. As the binder resin, a styrene acrylic resin was used as the amorphous resin for the core particles, a crystalline polyester resin was used as the crystalline resin, and an amorphous polyester resin was used as the amorphous resin for the shell.

[Preparation of fine particle dispersion]
(1) Preparation of water-based dispersion liquid [1] of styrene acrylic resin fine particles (containing mold release agent) (first stage polymerization)
In a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube and a nitrogen introduction device, a solution prepared by dissolving 8 g of sodium dodecyl sulfate in 3 L of ion-exchanged water was charged, and the mixture was stirred at a stirring speed of 230 rpm under a nitrogen stream. The internal temperature was raised to 80 ° C. Then, a solution prepared by dissolving 10 g of potassium persulfate in 200 g of ion-exchanged water was added, the liquid temperature was adjusted to 80 ° C. again, and a vinyl monomer solution consisting of 480 g of styrene, 250 g of n-butyl acrylate and 68 g of methacrylic acid was added for 1 hour. After dropping the mixture, the mixture was heated at 80 ° C. for 2 hours and stirred to carry out polymerization to obtain a dispersion of resin fine particles [a1].

(Second stage polymerization)
In a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube and a nitrogen introduction device, a solution prepared by dissolving 9.2 g of sodium dodecyl ether sulfate in 1500 mL of ion-exchanged water was charged, heated to 98 ° C., and then the above resin. 288.8 g (solid content mass) of the dispersion liquid of the fine particles [a1], a vinyl monomer solution consisting of 211.4 g of styrene, 26 g of 2-ethylhexyl acrylate and 25 g of methacrylic acid, 3.3 g of n-octyl mercaptan, and separation. As a mold, 240 g of N252 (product name, manufactured by Chukyo Yushi Co., Ltd., behenyl behenate, melting point T _mw 77 ° C.) was dissolved at 90 ° C. and mixed with a mixed solution, and a mechanical disperser having a circulation path A dispersion containing emulsified particles (oil droplets) was prepared by mixing and dispersing with "CLEARMIX" (manufactured by M Technique Co., Ltd.) for 1 hour.

Next, an initiator solution prepared by dissolving 4.5 g of potassium persulfate in 85 mL of ion-exchanged water was added to this dispersion, and the system was heated and stirred at 84 ° C. for 1 hour to carry out polymerization, and resin fine particles [ The dispersion liquid of a2] was obtained.

(Third stage polymerization)
A solution prepared by dissolving 6.7 g of potassium persulfate in 115 mL of ion-exchanged water was added to the above dispersion of the resin fine particles [a2], and under a temperature condition of 82 ° C., 301.7 g of styrene and 145 g of n-butyl acrylate were added. , 28.5 g of methacrylic acid and 43 g of methyl methacrylate and 7.0 g of n-octyl mercaptan were added dropwise over 1 hour. After completion of the dropping, polymerization was carried out by heating and stirring for 2 hours, and then the mixture was cooled to 28 ° C., whereby fine particles (release agent; 12% by mass, styrene acrylic) made of a styrene acrylic resin containing a release agent were obtained. A styrene acrylic resin fine particle dispersion [1] containing a resin (88% by mass) at a solid content concentration of 30% by mass was prepared.

The amorphous resin fine particles (styrene acrylic resin fine particles) had a volume-based median diameter of 220 nm, a weight average molecular weight (Mw) of 25,000, and a glass transition point of 40.0 ° C.

(2) Preparation of crystalline polyester resin fine particle dispersion (synthesis of crystalline polyester resin)
In a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube and a nitrogen introduction device, 300 parts by mass of dodecanedioic acid (1,10-decandicarboxylic acid) as a polyvalent carboxylic acid and 1,4 as a polyhydric alcohol. − 170 parts by mass of butanediol was charged, the internal temperature was raised to 190 ° C. over 1 hour while stirring this system, and after confirming that the mixture was uniformly stirred, Ti (OBu) was used as a catalyst. ) 4 was added in an amount of 0.003% by mass based on the amount of the polyvalent carboxylic acid charged.

Then, while distilling off the generated water, the internal temperature is raised from 190 ° C. to 240 ° C. over 6 hours, and the dehydration condensation reaction is continued for 6 hours under the condition of a temperature of 240 ° C. to carry out polymerization. To obtain a crystalline polyester resin [1]. This crystalline polyester resin [1] had a melting point T _mp of 68 ° C. and a weight average molecular weight (Mw) of 7,000.

(Preparation of crystalline polyester resin fine particle dispersion)
Crystalline polyester resin [1] 200 parts by mass of ethyl acetate is dissolved in 200 parts by mass of ethyl acetate, and while stirring this solution, sodium polyoxyethylene lauryl ether sulfate is added to 800 parts by mass of ion-exchanged water so that the concentration becomes 1% by mass. The dissolved aqueous solution was slowly added dropwise. After removing ethyl acetate from this solution under reduced pressure, the pH was adjusted to 8.5 with ammonia. Then, the solid content concentration was adjusted to 20% by mass. As a result, a crystalline polyester resin fine particle dispersion liquid [1] in which fine particles of the crystalline polyester resin [1] were dispersed in an aqueous medium was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [1] was 200 nm.

(3) Preparation of Amorphous Polyester Resin Fine Particle Dispersion Liquid (Synthesis of Amorphous Polyester Resin)
85 parts by mass of terephthalic acid, 6 parts by mass of trimellitic acid, 18 parts by mass of fumaric acid and dodecenyl succinic anhydride 80 as polyvalent carboxylic acid in a reaction vessel equipped with a stirrer, a nitrogen introduction tube, a temperature sensor and a rectification tower. 381 parts by mass of bisphenol A propylene oxide adduct and 62 parts by mass of bisphenol A ethylene oxide adduct were charged as polyhydric alcohol, and the temperature of the reaction system was raised to 190 ° C. over 1 hour to make the inside of the reaction system uniform. It was confirmed that the mixture was stirred. After that, Ti (OBu) ₄ was added as a catalyst in an amount of 0.006% by mass based on the total amount of the polyvalent carboxylic acid, and the temperature of the reaction system was changed from the same temperature while distilling off the generated water. The amorphous polyester resin [1] was obtained by raising the temperature to 240 ° C. over 6 hours and continuing the dehydration condensation reaction for 6 hours while maintaining the temperature at 240 ° C. to carry out the polymerization reaction.

The amorphous polyester resin [1] had a weight average molecular weight (Mw) of 10000 and a glass transition point of 60 ° C.

(Preparation of amorphous polyester resin fine particle dispersion)
200 parts by mass of amorphous polyester resin [1] is dissolved in 200 parts by mass of ethyl acetate, and while stirring this solution, the concentration of sodium polyoxyethylene lauryl ether sulfate in 800 parts by mass of ion-exchanged water becomes 1% by mass. The dissolved aqueous solution was slowly added dropwise. After removing ethyl acetate from this solution under reduced pressure, the pH was adjusted to 8.5 with ammonia. Then, the solid content concentration was adjusted to 20% by mass. As a result, an amorphous polyester resin fine particle dispersion liquid [1] in which fine particles of the amorphous polyester resin [1] were dispersed in an aqueous medium was prepared. The volume-based median diameter of the fine particles of the amorphous polyester resin [1] was 130 nm.

(4) Preparation of Aqueous Dispersion Liquid [Bk] of Colorant Fine Particles 90 parts by mass of sodium dodecyl sulfate was added to 1600 parts by mass of ion-exchanged water. While stirring this solution, gradually add 420 parts by mass of carbon black (Regal 330R: manufactured by Cabot Corporation), and then disperse the solution using a stirring device "Clearmix" (manufactured by M-Technique Co., Ltd.). To prepare an aqueous dispersion [Bk] of the colorant fine particles. With respect to the obtained aqueous dispersion [Bk], the average particle size (volume-based median diameter) of the colorant fine particles was 110 nm.

(5) Preparation of toner matrix particles (first step; (b) agglutination / fusion step)
In a zebra flask (reaction kettle) equipped with a stirrer, temperature sensor, cooling tube and nitrogen introduction device, styrene acrylic resin fine particle dispersion liquid [1] 1600 parts by mass (solid content conversion, mold release agent; 12% by mass, styrene acrylic Resin; 88% by mass), crystalline polyester resin fine particle dispersion [1] 300 parts by mass (solid content equivalent), ion exchange water 1500 parts by mass, and aqueous dispersion of colorant fine particles [Bk] 500 parts by mass (solid content) (Conversion) and adjust the rotation speed of the stirrer to 150 rpm. Next, after adjusting the liquid temperature to 25 ° C., a sodium hydroxide aqueous solution having a concentration of 25% by mass was added to adjust the pH to 10, and the rotation speed of the stirrer was adjusted to 245 rpm.

Next, an aqueous solution prepared by dissolving 54.3 parts by mass of magnesium chloride hexahydrate in 54.3 parts by mass of ion-exchanged water was added, and then the temperature of the system was raised to 87 ° C. When the temperature rise was completed, the rotation speed of the stirring device was reduced to 100 rpm, and the aggregation / fusion treatment of each resin fine particle and the colorant fine particle was started.

After the start of this agglomeration / fusion treatment, sampling is performed regularly, and the volume-based median diameter of the agglomerated / fused particles is determined using the particle size distribution measuring device "Colter Multisizer 3" (manufactured by Beckman Coulter). By measuring, agglomeration / fusion treatment is performed until the volume-based median diameter reaches 6.3 μm, and when the particle size is reached, the rotation speed of the stirrer is increased to 245 rpm and shearing is applied to the extent that agglomeration does not occur. A dispersion of core particles was obtained so that aggregation and fusion did not proceed.

Next, the temperature of the reaction kettle containing the dispersion liquid of the core particles was set to 75 ° C., and when the temperature reached 75 parts by mass (solid content equivalent) of the amorphous polyester resin fine particle dispersion liquid [1] was added. Then, a shell layer was formed on the surface of the core particles to obtain core-shell particles.

After that, an aqueous solution prepared by dissolving 23.0 parts by mass of sodium chloride in 96 parts by mass of ion-exchanged water was added to the above reaction vessel, and the core was measured by a flow-type particle image analyzer "FPIA-2100" (manufactured by Sysmex). Stirring was continued for 2 hours until the average circularity of the shell particles reached 0.960.

(Second step)
In the above, when the average circularity of the core-shell particles reaches 0.960, the dispersion of the core-shell particles as the toner matrix particle precursor is cooled to 30 ° C. under the condition of 6 ° C./min. The reaction was stopped.

(Third step)
After cooling, the liquid separation of the toner matrix particle precursor is heated again to 60 ° C. at a heating rate of 6 ° C./min and held at the temperature (60 ° C.) for 3 hours to crystallize the crystalline polyester resin. Was promoted. Then, the mixture was cooled at a temperature lowering rate of 6 ° C./min to stop the reaction, and a dispersion of toner matrix particles was obtained. The average particle size (volume-based median diameter) of the toner matrix particles after cooling was 6.1 μm, and the average circularity was 0.946.

(Filtration / cleaning and drying process)
The dispersion of toner matrix particles thus obtained was solid-liquid separated using a basket-type centrifuge "MARK III model number 60 × 40" (manufactured by Matsumoto Machinery Co., Ltd.) to form a wet cake. The wet cake was repeatedly washed and solid-liquid separated with the basket-type centrifuge until the electrical conductivity of the filtrate became 15 μS / cm. After that, using a "flash jet dryer" (manufactured by Seishin Enterprise Co., Ltd.), a stream of airflow having a temperature of 40 ° C. and a humidity of 20% RH is used to dry the particles until the water content reaches 0.5% by mass, and the mixture is cooled to 24 ° C. As a result, toner matrix particles [1] were obtained. The toner matrix particles [1] had a volume-based median diameter of 6.1 μm and an average circularity of 0.966.

(6) Addition of external additive 1 part by mass of hydrophobic silica particles and 1.2 parts by mass of hydrophobic titanium oxide particles were added to 100 parts by mass of the obtained toner base particles [1], and a Henschel mixer was used. The mixture was mixed over 20 minutes under the condition of a peripheral speed of 24 m / s of the rotary blade, and an external additive was further added by passing through a sieve of 400 mesh to obtain a toner [1]. In the toner [1], the shape and particle size of the toner [1] did not change due to the addition of the external additive.

<Examples 2 to Comparative Example 3: Manufacture of Toners 2 to 19>
In producing the toners 2 to 19, crystalline polyester resin fine particle dispersions [2] to [7] and styrene acrylic resin fine particle dispersions [2] to [4] containing a release agent were prepared as follows.

(Synthesis of crystalline polyester resin [2])
A crystalline polyester resin [2] was produced in the same manner except that 6 hours was changed to 3 hours in the dehydration condensation reaction time in the production step of the crystalline polyester resin [1]. This crystalline polyester resin [2] had a melting point T _mp of 67 ° C. and a weight average molecular weight (Mw) of 4000.

(Synthesis of crystalline polyester resin [3])
A crystalline polyester resin [3] was produced in the same manner except that 6 hours was changed to 12 hours in the dehydration condensation reaction time in the production step of the crystalline polyester resin [1]. This crystalline polyester resin [3] had a melting point T _mp of 64 ° C. and a weight average molecular weight (Mw) of 20000.

(Synthesis of crystalline polyester resin [4])
In the production of the crystalline polyester resin [1], 170 parts by mass of 1,4-butanediol was changed to 170 parts by mass of 1,6-hexanediol, and 6 hours of the dehydration condensation reaction time was changed to 3 hours. A crystalline polyester resin [4] was produced in the same manner except for the above. This crystalline polyester resin [4] had a melting point T _mp of 65 ° C. and a weight average molecular weight (Mw) of 5000.

(Synthesis of crystalline polyester resin [5])
In the production of the crystalline polyester resin [1], 170 parts by mass of 1,4-butanediol was changed to 170 parts by mass of 1,6-hexanediol, and 6 hours of the dehydration condensation reaction time was changed to 12 hours. A crystalline polyester resin [5] was produced in the same manner except for the above. This crystalline polyester resin [5] had a melting point T _mp of 63 ° C. and a weight average molecular weight (Mw) of 20000.

(Synthesis of crystalline polyester resin [6])
A crystalline polyester resin [6] was produced in the same manner except that 6 hours was changed to 16 hours in the dehydration condensation reaction time in the production step of the crystalline polyester resin [1]. This crystalline polyester resin [6] had a melting point T _mp of 64 ° C. and a weight average molecular weight (Mw) of 30,000.

(Synthesis of crystalline polyester resin [7])
In the production of the crystalline polyester resin [1], the same applies except that 300 parts by mass of dodecanedioic acid (1,10-decandicarboxylic acid) was changed to 300 parts by mass of tetradecanedioic acid (1,12-dodecanedicarboxylic acid). To prepare a crystalline polyester resin [7]. This crystalline polyester resin [7] had a melting point T _mp of 78 ° C. and a weight average molecular weight (Mw) of 7,000.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [2])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [2]. A dispersion liquid [2] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [2] was 202 nm.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [3])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [3]. A dispersion liquid [3] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [3] was 210 nm.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [4])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [4]. A dispersion liquid [4] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [4] was 195 nm.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [5])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [5]. A dispersion liquid [5] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [5] was 200 nm.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [6])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [6]. A dispersion liquid [6] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [6] was 200 nm.

(Preparation of Crystalline Polyester Resin Fine Particle Dispersion Liquid [7])
Crystalline polyester resin fine particles in the same manner except that 200 parts by mass of the crystalline polyester resin [1] in the preparation step of the crystalline polyester resin fine particle dispersion liquid [1] of Example 1 was changed to the crystalline polyester resin [7]. A dispersion liquid [7] was prepared. The volume-based median diameter of the fine particles of the crystalline polyester resin [7] was 203 nm.

(Preparation of styrene acrylic resin fine particle dispersion liquid (2))
In the preparation of the styrene acrylic resin fine particle dispersion liquid [1] of Example 1, 240 parts by mass of the release agent [N252] in the second stage polymerization step was used as the release agent "SELOSOL R-582 (product name, manufactured by Chukyo Yushi Co., Ltd.). Paraffin wax, melting point T _mw 70 ° C.) ”was changed to 240 parts by mass, and an aqueous dispersion liquid (2) of styrene acrylic resin fine particles was prepared in the same manner. The amorphous resin fine particles had a volume-based median diameter of 230 nm, a weight average molecular weight (Mw) of 25500, and a glass transition point of 40.5 ° C.

(Preparation of water-based dispersion liquid (3) of styrene acrylic resin fine particles)
In the preparation of the styrene acrylic resin fine particle dispersion liquid [1] of Example 1, 240 parts by mass of the release agent [N252] in the second stage polymerization step was used as the release agent "HNP-0190 (product name, manufactured by Nippon Seiko Co., Ltd.). Microcrystalline wax (paraffin wax), melting point T _mw 83 ° C.) ”was changed to 240 parts by mass, and an aqueous dispersion liquid (3) of styrene acrylic resin fine particles was prepared in the same manner. The amorphous resin fine particles had a volume-based median diameter of 230 nm, a weight average molecular weight (Mw) of 25500, and a glass transition point of 40.5 ° C.

(Preparation of water-based dispersion liquid (4) of styrene acrylic resin fine particles)
In the preparation of the styrene acrylic resin fine particle dispersion liquid [1] of Example 1, 240 parts by mass of the release agent [N252] in the step of the second stage polymerization was used as the release agent "FNP-0090 (product name, manufactured by Nippon Seiko Co., Ltd.). Paraffin wax, melting point T _mw 90 ° C.) ”was changed to 240 parts by mass, and an aqueous dispersion liquid (4) of styrene acrylic resin fine particles was prepared in the same manner. The amorphous resin fine particles had a volume-based median diameter of 230 nm, a weight average molecular weight (Mw) of 25500, and a glass transition point of 41.0 ° C.

<Example 2>
Toner [2] was obtained in the same manner except that the heating conditions of holding at 60 ° C. for 3 hours in the third step of Example 1 were changed to holding at 57 ° C. for 3 hours. The toner [2] had a volume-based median diameter of 6.2 μm and an average circularity of 0.966.

<Example 3>
Toner [3], except that the heating conditions of 60 ° C. and 3 hours holding in the third step of Example 1 were changed to holding at 53 ° C. for 5 hours and then holding at 62 ° C. for 1 hour. Got This toner [3] had a volume-based median diameter of 6.2 μm and an average circularity of 0.966.

<Example 4>
Toner [4], except that the heating condition of 60 ° C. for 3 hours in the third step of Example 1 was changed to 50 ° C. for 5 hours and then 59 ° C. for 1 hour. Got This toner [4] had a volume-based median diameter of 6.2 μm and an average circularity of 0.966.

<Example 5>
Toner [5] was obtained in the same manner except that the heating conditions for holding at 60 ° C. for 3 hours in the third step of Example 1 were changed to holding at 60 ° C. for 9 hours. This toner [5] had a volume-based median diameter of 6.1 μm and an average circularity of 0.966.

<Example 6>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester resin fine particle dispersion [2], and the heating conditions of 60 ° C. and 3 hours holding in the third step were changed to 48 ° C. Toner [6] was obtained in the same manner except that the mixture was held for 5 hours and then held at 60 ° C. for 1 hour. This toner [6] had a volume-based median diameter of 6.3 μm and an average circularity of 0.966.

<Example 7>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester resin fine particle dispersion [3], and the heating conditions of 60 ° C. and 3 hours holding in the third step were changed to 50 ° C. Toner [7] was obtained in the same manner except that the mixture was held for 5 hours and then held at 62 ° C. for 1 hour. This toner [7] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 8>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester resin fine particle dispersion [4], and the heating conditions of 60 ° C. and 3 hour holding in the third step were set to 62 ° C. Toner [8] was obtained in the same manner except that the retention was changed to 3 hours. This toner [8] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 9>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester resin fine particle dispersion [5], and the heating conditions of 60 ° C. and 3 hours holding in the third step were set to 58 ° C. Toner [9] was obtained in the same manner except that the retention was changed to 3 hours. This toner [9] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 10>
1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] and 300 parts by mass of the crystalline polyester resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 are each 1690 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1]. , Crystallized polyester resin fine particle dispersion [1] Toner [10] was obtained in the same manner except that the amount was changed to 165 parts by mass. This toner [10] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 11>
1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] and 300 parts by mass of the crystalline polyester resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 are each 1240 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1]. A toner [11] was obtained in the same manner except that the crystalline polyester resin fine particle dispersion liquid [1] was changed to 840 parts by mass. This toner [11] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 12>
The toner [12] was obtained in the same manner except that 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 was changed to 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [2]. rice field. This toner [12] had a volume-based median diameter of 6.2 μm and an average circularity of 0.967.

<Example 13>
The toner [13] was obtained in the same manner except that 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 was changed to 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [3]. rice field. This toner [13] had a volume-based median diameter of 6.2 μm and an average circularity of 0.967.

<Example 14>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester dispersion [6], and the heating conditions of 60 ° C. for 3 hours in the third step were changed to 53 ° C. for 5 hours. After holding, the toner [14] was obtained in the same manner except that it was changed to hold at 62 ° C. for 1 hour. This toner [14] had a volume-based median diameter of 6.1 μm and an average circularity of 0.967.

<Example 15>
1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] and 300 parts by mass of the crystalline polyester resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 are each 1740 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1]. A toner [15] was obtained in the same manner except that the crystalline polyester resin fine particle dispersion liquid [1] was changed to 90 parts by mass. This toner [15] had a volume-based median diameter of 6.3 μm and an average circularity of 0.967.

<Example 16>
1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] and 300 parts by mass of the crystalline polyester resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 are each 1100 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1]. Toner [16] was obtained in the same manner except that the crystalline polyester resin fine particle dispersion liquid [1] was changed to 1050 parts by mass. This toner [16] had a volume-based median diameter of 6.3 μm and an average circularity of 0.968.

<Comparative example 1>
Toner [17] was obtained in the same manner except that the heating conditions of holding at 60 ° C. for 3 hours in the third step of Example 1 were changed to holding at 54 ° C. for 0.2 hours. This toner [17] had a volume-based median diameter of 6.2 μm and an average circularity of 0.966.

<Comparative example 2>
The crystalline polyester resin fine particle dispersion [1] used in Example 1 was changed to the crystalline polyester resin fine particle dispersion [7], and the heating conditions of 60 ° C. and 3 hours holding in the third step were changed to 48 ° C. Toner [18] was obtained in the same manner except that the mixture was held for 5 hours and then held at 60 ° C. for 1 hour. This toner [18] had a volume-based median diameter of 6.3 μm and an average circularity of 0.966.

<Comparative example 3>
The toner [19] was obtained in the same manner except that 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [1] used in the toner manufacturing process of Example 1 was changed to 1600 parts by mass of the styrene acrylic resin fine particle dispersion liquid [4]. rice field. This toner [19] had a volume-based median diameter of 6.2 μm and an average circularity of 0.967.

For the obtained toners [1] to [19], the rising temperature of the endothermic peak derived from the crystalline polyester resin T ₁ ° C. and the endothermic peak temperature T in the first heating process when the differential scanning calorimetry of each toner was measured. ₂ ° C., the endothermic peak temperature T ₃ ° C. derived from the mold release agent, and the toner outflow start temperature T _fb ° C. in the flow tester were measured. The results are shown in Table I together with the toner composition and production conditions (heating conditions in the third step). The content of each resin constituting the binder resin is a mass part in 100 parts by mass of the binder resin. The content of the release agent is a mass part with respect to 100 parts by mass of the binder resin. In the table, "StAc resin" indicates a styrene acrylic resin. The release agent "R-582" indicates SELOSOL R-582.

[Production Examples 1 to 19 of Developer]
To each of the toners [1] to [19], a ferrite carrier having a volume-based median diameter of 60 μm coated with a silicone resin was added so that the toner concentration was 6% by mass, and mixed by a V-type mixer. By doing so, the developing agents [1] to [19] were produced.

[Toner evaluation]
The following evaluations were carried out using the toners [1] to [19] prepared as described above and the developing agents [1] to [19] containing them, respectively. The results are shown in Table II.

(1) Evaluation of low-temperature fixability For low-temperature fixability, the surface temperature (measured at the center of the roller) of a heat-fixing roller in a commercially available copying machine "bizhub PRO C6550" (manufactured by Konica Minolta) as an image evaluation device is measured from 100 to 100. A modified product was used so that the temperature could be changed to the range of 200 ° C. Developers [1] to [19] are mounted as the developer (black), respectively, and the toner adhesion amount is 8 mg / on A4 size high-quality paper under normal temperature and humidity (temperature 20 ° C., humidity 50% RH) environment. The ^{fixing experiment for fixing a solid image (black) of cm 2} was repeated from 120 ° C. to 200 ° C. while changing the set fixing temperature from 120 ° C. in 1 ° C. increments. Among the fixing experiments in which image stains due to low temperature offset were not visually observed, the lowest temperature was evaluated as the lowest fixing temperature. As the minimum fixing temperature, those having an evaluation standard of less than 137 ° C. were accepted.

(Evaluation criteria)
⊚: less than 130 ° C 〇: 130 or more and less than 134 ° C Δ: 134 or more and less than 137 ° C ×: 137 ° C or more

(2) Evaluation of fixing separability Using the same image evaluation device as the evaluation of low temperature fixing property, the surface temperature of the heating fixing roller is set to 160 ° C, and a solid black band-shaped image having a width of 5 cm in the direction perpendicular to the transport direction is obtained. The separability between the heat fixing roller on the image side and the paper when the A4 paper was conveyed in the vertical feed direction was evaluated according to the following evaluation criteria. In the present invention, the case where the evaluation standard is "○" or "Δ" is regarded as acceptable.

(Evaluation criteria)
〇: The paper separates from the heat fixing roller without curling.
Δ: The paper separates from the heat fixing roller, but the tip of the paper curls slightly (no problem in practical use).
X: The paper separates from the heat fixing roller, but the gloss on the image surface is uneven, or the paper is wrapped around the heat fixing roller and cannot be separated from the heat fixing roller.

(3) Evaluation of heat-resistant storage performance 0.5 g of toner was placed in a 10 mL glass bottle with an inner diameter of 21 mm, the lid was closed, and the lid was removed after shaking with Tap Dencer KYT-2000 (manufactured by Seishin Enterprise Co., Ltd.) 600 times at room temperature. The state was left for 2 hours in an environment of 3 levels of 57.5 ° C., 60.0 ° C., 62.5 ° C. and 35% RH. Next, place the toner on a sieve of 48 mesh (opening 350 μm), being careful not to crush the toner aggregates, set it on a powder tester (manufactured by Hosokawa Micron Co., Ltd.), and fix it with a holding bar and a knob nut. After adjusting the vibration intensity to a feed width of 1 mm and applying vibration for 10 seconds, the ratio (mass%) of the amount of toner remaining on the sieve was measured.
The toner agglutination rate is a value calculated by the following formula.
Toner aggregation rate (%) = mass of residual toner on the sieve (g) /0.5 (g) x 100

The toner agglutination rate is measured at the above three levels of temperature, the temperature at which the agglutination rate becomes 50% is estimated, and the temperature is defined as the 50% agglutination temperature. The heat-resistant storage property (50% aggregation temperature) of the toner is evaluated according to the criteria described below, and in the present invention, the case where the evaluation criteria are "◎", "○" or "Δ" is accepted.

(Evaluation criteria)
⊚: 50% aggregation temperature is 62 ° C or higher (toner has extremely good heat-resistant storage property)
◯: 50% aggregation temperature is 60 ° C or higher and lower than 62 ° C (good heat-resistant storage of toner)
Δ: 50% aggregation temperature is 57.5 ° C or higher and lower than 60 ° C (slightly inferior in heat-resistant storage property of toner, but acceptable level)
X: 50% aggregation temperature is less than 57.5 ° C (cannot be used due to poor heat-resistant storage of toner)

From Table II, it can be seen that the toner of the present invention has excellent low-temperature fixability, heat-resistant storage property, and fixing separability.

Claims (9)

Toner containing a binder resin and a mold release agent A toner for developing an electrostatic charge image containing parent particles.
The binder resin contains an amorphous resin and a crystalline resin,
In the first heating process when the differential scanning calorimetry of the static charge image developing toner is performed, the rising temperature of the endothermic peak derived from the crystalline resin is T ₁ ° C, the endothermic peak temperature is T ₂ ° C, and A toner for static charge image development, which satisfies the following conditions (1), (2), (3) and (4) when the endothermic peak temperature derived from the mold release agent is T _{3 ° C.}
(1) T ₁ is in the range of 57 to 62 ° C.
(2) T ₂ is in the range of 60 to 70 ° C.
(3) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 12 ° C
(4) T ₂ and T ₃ have the following relationship.
T ₂ <T ₃ ≤ T ₂ + 15 ° C The toner for static charge image development according to claim 1, wherein the toner matrix particles have core particles and a shell layer that coats the core particles, and the crystalline resin is contained in the core particles. .. The first or second aspect of the present invention, wherein when the outflow start temperature measured by the flow tester of the static charge image developing toner is T _fb ° C., the condition of the following (5) is further satisfied. Toner for static charge image development.
(5) T ₂ and T _fb have the following relationship.
T ₂ ≤ T _fb ≤ T ₂ + 10 ° C The toner for static charge image development according to any one of claims 1 to 3, further comprising satisfying the following conditions (6), (7) and (8).
(6) T ₁ is in the range of 60 to 61 ° C.
(7) T ₂ is in the range of 62 to 66 ° C.
(8) T ₁ and T ₂ have the following relationship.
T ₂ ≤ T ₁ + 5 ° C The invention according to any one of claims 1 to 4, wherein the crystalline resin contains a crystalline polyester resin, and the weight average molecular weight of the crystalline polyester resin is in the range of 2000 to 25000. Toner for static charge image development. The toner for developing an electrostatic charge image according to claim 5, wherein the weight average molecular weight of the crystalline polyester resin is in the range of 4000 to 10000. The content of the crystalline resin is in the range of 4 to 31 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the release agent is with respect to 100 parts by mass of the binder resin. The static charge image developing toner according to any one of claims 1 to 6, wherein the toner is in the range of 6 to 20 parts by mass. The invention according to any one of claims 1 to 7, wherein the content of the crystalline resin is in the range of 10 to 20 parts by mass with respect to 100 parts by mass of the binder resin. Toner for developing static charge images. A method for producing an electrostatic charge image developing toner according to any one of claims 1 to 8, wherein the electrostatic charge image developing toner is produced.
The first step of obtaining a dispersion liquid containing a toner matrix particle precursor by heating and stirring the fine particles containing the binder resin and the release agent in an aqueous medium to aggregate and fuse them.
A second step of cooling the dispersion heated in the first step to a temperature of 30 ° C. or lower at a temperature lowering rate of 6 ° C./min or more, and a second step.
A third step of maintaining the dispersion liquid cooled in the second step at a temperature in the range of 57 to 62 ° C. for 30 minutes or more,
A method for producing a toner for static charge image development, which comprises producing the toner matrix particles by a method including.