JP2005062509A - Toner and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner which ensures good dispersibility of a release agent and a crystalline binder resin constituting the toner, and has good chargeability and fixability. <P>SOLUTION: In the toner used for forming an image by developing an electrostatic latent image formed on an electrostatic latent image carrier, a binder resin comprises a crystalline polyester and an amorphous polyester, the crystalline polyester is a block polyester having a higher softening point that the amorphous polyester obtained by copolymerizing amorphous blocks constituting the amorphous polyester and a crystalline block component, and the amorphous polyester comprises a plurality of amorphous polyesters different from each other in melt viscosity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toner used for electrophotographic image formation in which an image formed on an electrostatic latent image carrier or the like is developed to form an image, and a method for manufacturing the same.

The toner is a composition mainly composed of a binder resin and a pigment, which improves the quality of the formed image and can cope with various fixing conditions that vary depending on the characteristics of the recording member, environmental conditions, and the like. Various additives are added.
For example, in order to improve the offset resistance, a wax is added as a release agent. However, if the wax is poorly dispersed in the binder resin, there has been a problem such as filming or fusing of the developing device by toner.
In view of this, it has been proposed to use a plurality of types of binder resins as the binder resin and improve toner characteristics that cannot be obtained with one type of binder resin.
For example, a toner using a thermoplastic resin and polyester as a binder resin has been proposed (Patent Document 1).
However, the improvement in offset resistance is still insufficient.
Also, using other binder resin together with polyester, kneading of the binder resin and wax is performed by melt-kneading a resin obtained by dispersing wax in one resin and a resin having a higher softening point. Therefore, after pre-dispersing the wax uniformly in one resin in advance, in order to add and knead the resin with a high softening point, knead under high shear to improve the dispersion state of the wax. Has been proposed. (Patent Document 2)

  However, when an additive is kneaded with a non-crystalline polyester and a block polyester containing a high-melting-point crystalline component, the high-melting-point crystalline component and the release agent are separated from each other by a melting point or softening point, so that a high shear force is applied. However, it was difficult to obtain a kneaded state capable of. Further, when the high melting point crystalline component is melted, if it is diluted and kneaded at a high temperature, the dispersed particle diameter of additives such as a release agent and a charge control agent becomes large, which has a problem of adversely affecting the durability of the toner. On the other hand, if the additive is finely dispersed and diluted and kneaded at a low temperature, the high melting point crystal component is not dispersed and the high temperature offset is deteriorated.

In addition, when a toner is produced using crystalline polyester, amorphous resin, wax, charge control agent and colorant as raw materials, by providing a master batch process in which some of these raw materials are previously melt-kneaded, There has been proposed a toner manufacturing method that prevents problems that occur when polyester is added (Patent Document 3).
However, in the method described in Patent Document 3, a master batch process is provided in which an amount of 50% by mass or more of a raw material such as crystalline polyester, amorphous resin, wax, charge control agent, and colorant is previously melt-kneaded. It is. As a result, in the masterbatch process, all materials such as the release agent are melt-kneaded together with the binder resin, so that a high melting point material such as crystalline polyester and a material having a low melting point or softening point such as a release agent. Thus, it was impossible to obtain a toner in which components having a softening point or a low melting point were sufficiently dispersed.

  In addition, it has been proposed to obtain a toner having excellent storage stability, low-temperature fixability, offset resistance and environmental stability by incorporating a crystalline polyester into a toner using a polyester as a binder resin. (Patent Documents 4, 5, and 6), and the low-temperature fixability was improved by the action of the crystalline polyester used.

However, the crystalline polyester is intended to improve the low-temperature fixability and not the high-temperature offset property. In addition, since the crystalline polyester is manufactured using a raw material different from that of the amorphous polyester, the amorphous component constituting the crystalline polyester must be composed of components different from the amorphous polyester. It becomes. For this reason, the affinity between the crystalline polyester and the amorphous polyester is small, and there is a problem that the gloss is greatly reduced when the toner is used, and the transparency is deteriorated.
JP-A-5-188644 JP 2002-162787 A JP 2002-328490 A JP 2003-57874 A JP 2003-57875 A JP 2003-29460 A

  In the present invention, in a toner containing a plurality of binder resins, a dispersion state of a release agent, a charge control agent, a pigment, and the like is good, and crystalline polyester containing a high melting point component is used as a binder resin. Even in this case, it is an object of the present invention to provide a toner that has a good dispersion of a release agent such as a wax having a low melting point and that has no offset and has excellent fixability and durability.

An object of the present invention is to provide a toner used for developing an electrostatic latent image formed on an electrostatic latent image carrier to form an image, wherein the binder resin is composed of a crystalline polyester and an amorphous polyester, The crystalline polyester is a block polyester having a softening point higher than that of the amorphous polyester obtained by copolymerization of the amorphous block constituting the amorphous polyester and the crystalline block component, and the amorphous polyester. Can be solved by a toner composed of a plurality of amorphous polyesters having different melt viscosities.
Further, the toner includes a high melt viscosity amorphous polyester as the amorphous polyester, and a ratio of the high melt viscosity amorphous polyester to the total polyester resin is 5% by mass to 30% by mass.
Further, in a method for producing a toner used for developing an electrostatic latent image formed on an electrostatic latent image carrier to form an image, a plurality of amorphous polyesters having different melt viscosities as amorphous polyesters, As a crystalline polyester, the amorphous polyester constituting the amorphous polyester and a block polyester having a softening point higher than that of the amorphous polyester obtained by copolymerization of the amorphous block component are mixed, and the melting point is crystallized. In this method, a release agent lower than the melting point of the crystalline polyester is mixed and kneaded at a temperature lower than the melting point of the crystalline polyester.

As described above, the toner of the present invention uses a plurality of amorphous polyesters having different melt viscosities as the amorphous polyester in the toner using the crystalline polyester and the amorphous polyester as the binder resin. Since the non-crystalline polyester used is a block polyester having a softening point higher than that of the non-crystalline polyester obtained by copolymerization of the non-crystalline block constituting the non-crystalline polyester and the crystalline block component. As a result of the high melt viscosity component in the polyester increasing the viscosity during kneading, the compatibility between the crystalline polyester and the amorphous polyester is increased, and the crystalline component of the crystalline polyester having a high melting point can be finely dispersed. It becomes.
As a result, it is possible to obtain a toner in which the cohesive force is enhanced by the fine dispersion of the block polyester used as the crystalline polyester and the high temperature offset and the low temperature offset are prevented.

  In particular, in the present invention, the block polyester used as the crystalline polyester has a block structure containing a high-melting-point crystalline block component, and therefore has an action of increasing cohesion in the toner and preventing high temperature offset. Yes. On the other hand, it is considered that the deterioration of the storage stability and the decrease in chargeability of the toner to which the crystalline polyester is added are due to the thermal characteristics and chargeability of the low-melting crystalline polyester itself. Since the ester is used and the block polyester is produced by copolymerization of the amorphous component constituting the amorphous polyester and the high melting point crystalline component, the block polyester and the amorphous polyester are highly compatible with each other. When a release agent is added and kneaded at a temperature below the melting point of the block polyester, the block polyester can be finely dispersed and a high shearing force can be applied to the release agent to sufficiently knead the crystal. Toner storage and chargeability without compromising fixing properties such as high temperature offset It is possible to above.

  In the toner of the present invention, a resin master batch is manufactured by mixing and kneading only the binder resin in advance, and the desired resin is manufactured by kneading the obtained resin master batch with a release agent or the like. You may do it.

  The toner of the present invention includes a crystalline polyester and an amorphous polyester in which a plurality of different resins are binder resins, and the amorphous polyester and the crystalline component that constitute the amorphous polyester as the crystalline polyester. A non-crystalline polyester with a different melt viscosity is mixed with a non-crystalline polyester with a different melt viscosity, and even when kneaded at a temperature at which the crystalline polyester does not melt, Since amorphous polyester with high viscosity exists, fine dispersion of the crystalline polyester is achieved, and since the dilute kneading is not performed in a state where all the components are melted, the dispersed particles of the release agent The diameter does not increase and both high temperature offset and low temperature offset do not occur. Tsu DOO good range is wide, an average crystal length small toner is obtained.

  The present invention focuses on the physical properties of each component at the temperature at which the toner constituent components are kneaded and disperses the crystalline block polyester having a high melting point by kneading in the presence of a high melt viscosity amorphous polyester. The present inventors have found that it is possible to improve the dispersion of both the resin and the release agent.

  That is, when melt-kneaded under a temperature condition at which the crystalline block polyester having a high melting point melts, the shearing force does not sufficiently act on a release agent such as a wax having a low melting point, resulting in insufficient dispersion. On the other hand, when kneading under a temperature condition in which a large shear force is applied to the release agent so that the dispersed particle size of the release agent does not increase, the dispersibility of the crystalline block polyester becomes insufficient, resulting in a high temperature. There arises a problem that an adverse effect on the offset property or the like occurs.

Therefore, in the present invention, as the amorphous polyester, a plurality of amorphous polyesters having different melt viscosities are used and one of them is a high melt viscosity amorphous polyester, so that the amorphous polyester is kneaded in a softened state. In this case, the presence of the high melt viscosity polyester is considered to increase the compatibility with the crystalline polyester, and as a result, the dispersibility of the crystalline polyester can be enhanced.
Furthermore, the crystalline polyester in the present invention is a block polyester composed of an amorphous block and a crystalline block constituting the amorphous polyester. For this reason, the crystalline polyester has a higher melting point than the softening point of the amorphous polyester due to the presence of the crystalline block, greatly contributes to the improvement of the high temperature offset of the toner at the time of fixing the toner, and has a wide offset region. Can be provided.
On the other hand, the polyester used in the toners described in Patent Documents 3 to 6 is different from the block polyester, and contributes to the improvement of the high temperature offset and does not provide the toner having a wide offset region. There wasn't.

In the present invention, the high melt viscosity amorphous polyester is preferably 1 × 10 ⁵ to 5 × 10 ⁶ Pa · s.
The content of the high melt viscosity amorphous polyester with respect to the entire binder resin is preferably 5% by mass to 30% by mass, and more preferably 8% by mass to 30% by mass.
When the content of the high melt viscosity amorphous polyester is less than 5% by mass, the effect of improving the dispersibility by addition is insufficient. On the other hand, when the content exceeds 30% by mass, the low temperature fixability is adversely affected. It is not preferable because it affects.

  In addition, amorphous polyester having a low melt viscosity and amorphous polyester having a high melt viscosity can be produced by various methods, but by changing the esterification reaction conditions using the same raw material, Since the thing which the monomer unit which comprises polyester corresponds is obtained, and it becomes a thing with high affinity, it is preferable.

The kneading process of the present invention will be described below.
The toner of the present invention can be kneaded using a closed kneader, a uniaxial or biaxial kneading extruder, a continuous two-roll kneader, or the like. Moreover, it is preferable that the plurality of components used in the kneading step are mixed with stirring by a Henschel mixer or the like in advance and mixed uniformly.
The kneaded material thus obtained is cooled and pulverized, then coarsely pulverized by a hammer mill or the like, then finely pulverized by a jet mill or the like, and further classified by an airflow classifier, and then in a Henschel mixer, silica, titania It can be mixed with an external additive such as a toner.

Hereinafter, the components of the toner of the present invention will be described.
The present invention is composed of a plurality of amorphous polyesters including a specific block polyester and a high melt viscosity amorphous polyester as a binder resin, but may also include other resins.
In particular, it is higher than the amorphous polyester obtained by copolymerization of a plurality of amorphous polyesters including a high melt viscosity amorphous polyester and the amorphous block and the crystalline block component constituting the amorphous polyester. Dispersibility is improved by kneading block polyester, which is a softening point, with a release agent or the like at a temperature not higher than the melting point of the block polyester.
In addition, the same or different resin as the binder resin polyester may be introduced into the toner as a constituent component of a pigment masterbatch in which an additive such as a pigment is dispersed.
Specifically, the content of the polyester-based resin in the binder resin is preferably 50% by mass or more, and more preferably 80% by mass or more.

The block polyester of the present invention is composed of a block copolymer having a crystalline block obtained by condensing a diol component and a dicarboxylic acid component, and an amorphous block having a lower crystallinity than the crystalline block. is there. The block copolymer is obtained by a transesterification reaction between a crystalline block and an amorphous block.
The crystalline block has higher crystallinity than the amorphous block or the amorphous polyester. That is, the molecular arrangement structure is stronger and more stable than amorphous blocks and amorphous polyesters. For this reason, the crystalline block contributes to improving the strength of the entire toner. As a result, the finally obtained toner is resistant to mechanical stress and excellent in durability and storage stability.

  In general, a resin having high crystallinity has high-temperature offset resistance compared to a resin having low crystallinity. That is, a resin having high crystallinity has a property that the endothermic peak appears as a sharp shape when the endothermic peak of the melting point is measured by differential scanning calorimetry (DSC). Utilizing this property, a crystal component having a melting heat ΔQ of 3 J / g or more at the melting peak of the crystal component is said to be crystalline.

The crystalline block constituting the block polyester in the toner of the present invention has a function of imparting sharp melt properties to the block polyester. Therefore, the toner of the present invention can maintain excellent shape stability even at a relatively high temperature near the melting point of the block polyester so that the amorphous polyester is sufficiently softened.
Therefore, the toner of the present invention can exhibit not only a good high temperature offset property based on the crystalline component of the block polyester but also a fixing property including a sufficient fixing strength in a wide temperature range.

Amorphous polyester has lower crystallinity than block polyester described later.
Amorphous polyester is mainly composed of dispersibility of colorant, wax, charge control agent, etc. constituting toner, kneadability of kneaded product during toner production, fixing property such as low temperature fixing property of toner, transparency, elasticity. It is a component that contributes to improving mechanical properties such as mechanical strength, functions such as chargeability and moisture resistance.

Hereinafter, the components constituting the amorphous polyester will be described.
Examples of the diol component constituting the amorphous polyester include an aromatic diol having an aromatic ring structure and an aliphatic diol having no aromatic ring structure. Specific examples of the aromatic diol include bisphenol A and alkylene oxide adducts of bisphenol A. Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,2- Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propane Diol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2- Methyl-2,4-pentanediol, 3-methyl 1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, polyethylene glycol Chain diols such as polypropylene glycol and polytetramethylene glycol, or alkylene oxide adducts of 2,2-bis (4-hydroxycyclohexyl) propane and 2,2-bis (4-hydroxycyclohexyl) propane, 1,4 -Cyclic diols such as cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, alkylene oxide adducts of hydrogenated bisphenol A, and the like.

  As the dicarboxylic acid component constituting the amorphous polyester, a divalent carboxylic acid or a derivative of a divalent carboxylic acid such as an acid anhydride or a lower alkyl ester can be used. For example, phthalic acid, terephthalic acid, isophthalic acid Succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid and their acid anhydrides, lower alkyl esters and other derivatives.

Thus, it is preferable that at least a part of the dicarboxylic acid component constituting the amorphous polyester has a terephthalic acid skeleton, and that 80 mol% or more of the dicarboxylic acid has a terephthalic acid skeleton. More preferably, 90 mol% or more of them has a terephthalic acid skeleton.
As a result, the properties of the finally obtained toner are particularly excellent. However, the “dicarboxylic acid component” here refers to the dicarboxylic acid component when the amorphous polyester is used, and when preparing the amorphous polyester, the dicarboxylic acid component itself or its acid anhydride is used. In addition, derivatives such as lower alkyl esters can be used.

Moreover, it is preferable that the monomer component which comprises amorphous polyester is 50 mol% or more, More preferably, 80 mol% or more is the same as the monomer unit which comprises the amorphous block mentioned above. That is, the amorphous polyester is preferably composed of monomer units similar to the amorphous block. Thereby, the compatibility between the amorphous polyester and the block polyester is particularly excellent. The “monomer unit” here does not refer to the monomer itself used in the production of the amorphous polyester or block polyester, but refers to the monomer unit contained in the amorphous polyester or block polyester.
Further, the amorphous polyester may contain a component other than the diol component and the dicarboxylic acid component as described above, for example, a trivalent or higher alcohol component, a trivalent or higher carboxylic acid component, and the like.

The weight average molecular weight (Mw) of the low melt viscosity amorphous polyester is preferably 5 × 10 ³ to 4 × 10 ⁴ , and more preferably 8 × 10 ^{3 to} 2.5 × 10 ⁴ . If the weight average molecular weight Mw is less than 5 × 10 ³ , the mechanical strength of the finally obtained toner is lowered, and sufficient durability and storage stability may not be obtained. On the other hand, if the weight average molecular weight Mw is too small, cohesive failure is likely to occur at the time of fixing the toner, and the offset resistance tends to decrease. On the other hand, when the average molecular weight Mw exceeds 4 × 10 ⁴ , grain boundary breakage is liable to occur at the time of fixing the toner, wettability to a recording member such as paper is reduced, and the amount of heat required for fixing is increased.

  The glass transition point Tg of the low melt viscosity amorphous polyester is preferably 40 to 75 ° C, and more preferably 50 to 70 ° C. When the glass transition point is less than 40 ° C., the storage stability and heat resistance of the toner are lowered, and depending on the use environment, fusion between toner particles may occur. On the other hand, when the glass transition point exceeds 75 ° C., the low-temperature fixability and transparency deteriorate. If the glass transition point is too high, the glass transition point can be measured according to JIS K7121.

The softening point Tf of the low melt viscosity amorphous polyester is preferably 90 to 160 ° C, more preferably 95 to 150 ° C, and further preferably 95 to 130 ° C. When the softening point is less than 90 ° C., the storage stability as a toner is lowered and sufficient durability may not be obtained. On the other hand, if the softening point is too low, cohesive failure is likely to occur at the time of fixing the toner, and the offset resistance tends to decrease. On the other hand, when the softening point exceeds 160 ° C., it becomes easy to cause grain boundary destruction at the time of fixing the toner, the wettability to a recording member such as paper is reduced, and the amount of heat required for fixing is increased.
The softening point Tf was measured using a flow tester under the conditions of a sample amount of 1 g, a die hole diameter of 1 mm, a die length of 1 mm, and an extrusion pressure of 1.96 MPa. It can be determined as the temperature of T _1/2 which is the temperature.

In the present invention, the high melt viscosity amorphous polyester preferably has a weight average molecular weight Mw of 1 × 10 ^{4 to} 3 × 10 ⁵ , more preferably 3 × 10 ⁴ to 1 × 10 ^5. preferable. Moreover, it is preferable that it is 60 to 80 degreeC, and, as for glass transition point Tg, it is more preferable that it is 65 to 75 degreeC.
The softening point Tf is preferably 140 ° C to 180 ° C, and more preferably 140 ° C to 170 ° C.

In the present invention, as the amorphous polyester described above, it is possible to produce an amorphous polyester having a low melt viscosity and an amorphous polyester having a high melt viscosity by changing reaction raw materials, reaction conditions, and the like. However, it is preferable to produce amorphous polyesters having different melt viscosities by changing only the reaction conditions using the same reaction raw material.
The amorphous polyester is also preferably a linear polymer, like the block polyester. Linear polymers have a smaller coefficient of friction than cross-linked polymers. Thereby, particularly excellent releasability is obtained, and the transfer efficiency of the toner is further improved.

Hereinafter, the component which comprises the crystalline block of block polyester is demonstrated.
Examples of the diol component constituting the crystalline block include aromatic diols and aliphatic diols. Examples of aromatic diols include bisphenol A and alkylene oxide adducts of bisphenol A. Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1 , 3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2 , 4-Pentanediol, 3-methyl 1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, polyethylene glycol, polypropylene Chain diols such as glycol and polytetramethylene glycol, or 2,2-bis (4-hydroxycyclohexyl) propane, alkylene oxide adduct of 2,2-bis (4-hydroxycyclohexyl) propane, 1,4-cyclohexane Examples thereof include cyclic diols such as diol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of hydrogenated bisphenol A.

  Thus, it is preferable that at least a part of the diol component constituting the crystalline block is an aliphatic diol, more preferably 80 mol% or more of the diol component is an aliphatic diol, and 90 mol% or more is a fatty diol. More preferred are group diols. Thereby, the crystallinity of the crystalline block of block polyester can be made especially high, and the effect mentioned above becomes still more remarkable.

The diol component constituting the crystalline block has a linear molecular structure having 3 to 7 carbon atoms, and has hydroxyl groups at both ends (general formula: HO— (CH ₂ ) _n —OH). It is preferable that the diol (however, n = 3-7) represented is included. By including such a diol component, the crystallinity is improved and the coefficient of friction is lowered, so that it is resistant to mechanical stress and particularly excellent in durability and storage stability. Examples of such diols include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and the like, among which 1,4-butanediol Is preferred. By including 1,4-butanediol, the above-described effects become particularly remarkable.

  When 1,4-butanediol is included as the diol component constituting the crystalline block, 50 mol% or more of the diol constituting the crystalline block is more preferably 1,4-butanediol, and 80 mol% or more thereof is 1 More preferred is 4-butanediol. Thereby, the effect mentioned above becomes further remarkable.

  As the dicarboxylic acid component constituting the crystalline block, a divalent carboxylic acid or a derivative thereof such as an acid anhydride or a lower alkyl ester can be used. Specifically, for example, phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid and acid anhydrides thereof And derivatives such as lower alkyl esters.

The dicarboxylic acid component constituting the crystalline block preferably has at least a part thereof having a terephthalic acid skeleton, and more preferably 50 mol% or more of the dicarboxylic acid component has a terephthalic acid skeleton. More preferably, 80 mol% or more thereof has a terephthalic acid skeleton.
Thereby, the finally obtained toner is excellent in various properties required as a toner. The “dicarboxylic acid component” means a component that acts as a dicarboxylic acid component when a block polyester is formed. When the block polyester is prepared to form a crystalline block, the dicarboxylic acid component itself, its acid Derivatives such as anhydrides and lower alkyl esters may be used.

The content of the crystalline block in the block polyester is preferably 5 to 60 mol%, and more preferably 10 to 40 mol%. If the content of the crystalline block is less than 5 mol%, the effect of having the crystalline block may not be sufficiently exhibited. On the other hand, if the content of the crystalline block exceeds 60 mol%, the content of the amorphous block is relatively lowered, and the compatibility between the block polyester and the amorphous polyester may be lowered.
The crystalline block may contain a trivalent or higher valent alcohol component, a trivalent or higher carboxylic acid component, and the like in addition to the diol component and the dicarboxylic acid component.

Next, the amorphous block of polyester will be described.
The amorphous block is a component having a lower crystallinity than the crystalline block, and is a component having a lower crystallinity than the crystalline block, like the amorphous polyester.
Since the block polyester resin of the present invention contains a highly crystalline block and an amorphous block similar to the amorphous polyester, the highly crystalline block polyester resin and the amorphous polyester resin are mixed. In this case, the compatibility and dispersibility of the amorphous block and the amorphous polyester are expected to increase, and the advantages of the block polyester and the amorphous polyester should be fully and stably exhibited. Can do.

Next, the amorphous block in the block polyester will be described.
Examples of the diol component constituting the amorphous block include an aromatic diol having an aromatic ring structure and an aliphatic diol having no aromatic ring structure.
Examples of aromatic diols include bisphenol A and alkylene oxide adducts of bisphenol A. Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1 , 3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2 , 4-Pentanediol, 3-methyl 1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, polyethylene glycol, polypropylene Chain diols such as glycol and polytetramethylene glycol, or 2,2-bis (4-hydroxycyclohexyl) propane, alkylene oxide adduct of 2,2-bis (4-hydroxycyclohexyl) propane, 1,4-cyclohexane Examples thereof include cyclic diols such as diol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of hydrogenated bisphenol A.

  Further, at least a part of the diol component constituting the amorphous block is preferably an aliphatic diol, and more preferably 50 mol% or more of the diol component is an aliphatic diol. Thereby, it is possible to obtain an effect that a fixed image having higher toughness and excellent bending resistance can be obtained.

  Further, the diol component constituting the amorphous block preferably has at least a part thereof having a branched chain, and more preferably 30 mol% or more thereof has a branched chain. Thereby, the effect of suppressing regular arrangement, reducing crystallinity, and improving transparency is obtained.

  As the dicarboxylic acid component constituting the amorphous block, divalent carboxylic acids or acid anhydrides, derivatives such as lower alkyl esters, and the like can be used. For example, phthalic acid, terephthalic acid, isophthalic acid, succinic acid, Examples include adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, and derivatives of these acid anhydrides and lower alkyl esters.

Moreover, as a dicarboxylic acid component which comprises an amorphous block, what has at least one part has a terephthalic acid skeleton, and what has 80 mol% or more of a terephthalic acid skeleton is more preferable. As a result, the toner characteristics are improved.
In addition, the “dicarboxylic acid component” is the same as in the case of the crystalline block, and is a dicarboxylic acid component when the block polyester is prepared. When the block polyester is prepared to form the amorphous block, the dicarboxylic acid component is used. Derivatives such as an acid component, its acid anhydride, and a lower alkyl ester can be used.
In addition to the diol component and the dicarboxylic acid component as described above, the amorphous block may contain a trivalent or higher alcohol component, a trivalent or higher carboxylic acid component, and the like.

The weight average molecular weight (Mw) of the block polyester having a crystalline block and an amorphous block of the present invention is preferably 1 × 10 ^{4 to} 3 × 10 ⁵ , and 1.2 × 10 ^{4 to} 1.5. More preferably, it is × 10 ⁵ . When the weight average molecular weight Mw is less than 1 × 10 ⁴ , the mechanical strength of the toner is lowered, and sufficient durability and storage stability cannot be obtained. Is unfavorable because it decreases.
On the other hand, when the weight average molecular weight Mw exceeds ³ × 10 ⁵ , grain boundary breakage is liable to occur at the time of fixing the toner, the wettability with respect to a recording member such as paper is reduced, and the amount of heat required for fixing is increased.

  The glass transition point Tg of the block polyester is preferably 50 to 75 ° C, and more preferably 55 to 70 ° C. When the glass transition point is lower than 50 ° C., the storage stability and heat resistance of the toner are lowered, and fusion between toner particles may occur depending on the use environment. On the other hand, when the glass transition point exceeds 75 ° C., the low-temperature fixability and transparency deteriorate. On the other hand, if the glass transition point is too high, effects such as thermal spheronization of the toner may not be sufficiently exhibited. Moreover, a glass transition point can be measured based on JISK7121.

The softening point Tf of the block polyester is preferably 90 to 170 ° C, and more preferably 100 to 160 ° C. When the softening point is less than 90 ° C., the storage stability as a toner is lowered and sufficient durability may not be obtained. On the other hand, if the softening point is too low, cohesive failure is likely to occur at the time of fixing the toner, and offset resistance is reduced.
On the other hand, if the softening point exceeds 170 ° C., it becomes easy to cause grain boundary destruction at the time of fixing the toner, the wettability with respect to a recording member such as paper is reduced, and the amount of heat required for fixing is increased.
The softening point Tf is the temperature at the time when ½ amount of the sample flows out by using a flow tester, sample amount: 1 g, die hole diameter: 1 mm, die length: 1 mm, extrusion pressure: 1.96 Mpa. This is performed by the required 1/2 method.

  The melting point Tm of the block polyester is preferably 190 ° C. or higher, more preferably 190 to 230 ° C. When the melting point is less than 190 ° C., there is a possibility that effects such as improvement in offset resistance cannot be sufficiently obtained. If the melting point is too high, the material temperature must be relatively high in the kneading step or the like. As a result, the transesterification reaction of the resin material easily proceeds. The melting point can be determined by measuring an endothermic peak by differential scanning calorimetry (DSC).

The block polyester is preferably a linear polymer. Linear polymers have a smaller coefficient of friction than cross-linked polymers. Thereby, particularly excellent releasability is obtained, and the transfer efficiency of the toner is improved.
In addition, block polyester may have blocks other than the crystalline block mentioned above and an amorphous block.
In addition, the block polyester can be obtained by reacting the above-described amorphous polyester with a diol component and a carboxylic acid component, whereby a polyester having a high affinity between them can be obtained.

  Both the block polyester and the amorphous polyester are preferably linear polymers. Linear polymers have a smaller coefficient of friction than cross-linked polymers. As a result, particularly excellent releasability is obtained, and toner transfer efficiency is further improved.

  As described above, the toner of the present invention includes, as a binder resin, an amorphous polyester having a low melt viscosity, an amorphous polyester having a high melt viscosity, an amorphous block constituting the amorphous polyester, and a crystalline property. By using a block polyester obtained by copolymerization with a block component in combination with an amorphous polyester, a toner having predetermined characteristics can be obtained.

  The blending ratio of the block polyester and the amorphous polyester is preferably 5:95 to 45:55, more preferably 10:90 to 30:70, by weight. If the blending ratio of the block polyester becomes too low, it may be difficult to sufficiently improve the offset resistance of the toner. On the other hand, if the blending ratio of the amorphous polyester is too low, sufficient low-temperature fixability and transparency may not be obtained. Further, if the blending ratio of the amorphous polyester is too low, it becomes difficult to efficiently pulverize the kneaded product to a uniform size, for example, in the pulverization step of the toner production method as described later.

In addition, the binder resin may include a third resin component other than the block polyester and the amorphous polyester.
Examples of the third resin component other than the block polyester and the amorphous polyester include polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, and styrene-butadiene copolymer. Polymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester -Styrene or styrene-substituted styrene resin such as methacrylic acid ester copolymer, styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, styrene-vinyl methyl ether copolymer Homopolymers containing Or copolymer, polyester resin (different from the above-mentioned block polyester and amorphous polyester), epoxy resin, urethane-modified epoxy resin, silicone-modified epoxy resin, vinyl chloride resin, rosin-modified maleic acid resin, phenyl resin, Examples include polyethylene, polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, etc. These can be used alone or in combination of two or more.

  In the toner of the present invention, the content of the binder resin is preferably 50 to 98% by mass, and more preferably 85 to 97% by mass. When the content of the binder resin is less than 50% by mass, there is a possibility that good fixability in a wide temperature range may not be sufficiently exhibited in the finally obtained toner. On the other hand, when the resin content exceeds 98% by mass, the content of components other than the resin such as the colorant is relatively lowered, and it becomes difficult to sufficiently exhibit the properties such as color development of the toner.

  As the colorant, for example, a pigment, a dye, or the like can be used. Examples of such pigments and dyes include carbon black, spirit black, lamp black (CI No. 77266), magnetite, titanium black, chrome lead, cadmium yellow, mineral fast yellow, navel yellow, and naphthol yellow S. , Hansa Yellow G, Permanent Yellow NCG, Chrome Yellow, Benzidine Yellow, Quinoline Yellow, Tartrazine Lake, Red Mouth Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red, Permanent Red 4R, Watching Red Calcium salt, eosin lake, brilliant carmine 3B, manganese purple, fast violet B, methyl violet lake, bitumen, cobalt blue, al Reblue Lake, Victoria Blue Lake, First Sky Blue Indanthrene Blue BC, Ultramarine, Aniline Blue, Phthalocyanine Blue, Calco Oil Blue, Chrome Green, Chrome Oxide, Pigment Green B, Malachite Green Lake, Phthalocyanine Green, Final Yellow Green G, Rhodamine 6G, quinacridone, carmine 6B, rose bengal (C.I. No. 45432), C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modern Tread 30, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 184, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modern Blue 7, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 5: 1, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Basic Green 6, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 162, nigrosine dye (CI No. 50415B), metal complex dye, silica, aluminum oxide, magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, Examples thereof include metal oxides such as magnesium oxide and magnetic materials containing magnetic metals such as Fe, Co, and Ni, and one or more of these can be used in combination.

  Further, the content of the colorant in the toner raw material is preferably 1 to 10% by mass, and more preferably 3 to 8% by mass. If the content of the colorant is less than the lower limit, it may be difficult to form a visible image having a sufficient density depending on the type of the colorant. On the other hand, when the content of the colorant exceeds the upper limit, the content of the resin is relatively lowered, and the fixing property to a recording member such as paper at a necessary color density is lowered.

  The toner of the present invention may contain a release agent. When a release agent is added, the content is preferably 0.5 to 3% by mass in the toner, and if it exceeds 3% by mass, the transparency of the image may be hindered. .

  As release agents, hydrocarbon waxes such as ozokerite, cercin, paraffin wax, microwax, microcrystalline wax, petrolatum, Fischer-Tropsch wax, carnauba wax, rice wax, methyl laurate, methyl myristate, methyl palmitate , Methyl stearate, butyl stearate, candelilla wax, cotton wax, wood wax, beeswax, lanolin, montan wax, ester wax such as fatty acid ester, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, etc. Olefin wax, amide wax such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, laurone, stearo Ketone waxes and the like, ether-based wax and the like may be used singly or in combination of two or more of them.

Among the materials described above, the following effects can be obtained particularly when an ester wax such as carnauba wax or rice wax is used.
That is, the ester wax has an ester structure in the molecule, like the polyester resin used as the binder, and is excellent in compatibility with the polyester resin. Moreover, the polyester resin is excellent in compatibility with the resin as a main component. For this reason, generation and coarsening of free wax in the finally obtained toner particles can be prevented, and fine dispersion of the wax in the toner and microphase separation can be achieved. As a result, the obtained toner has excellent releasability from the fixing roll.
The melting point Tm of the wax is preferably 30 to 160 ° C, and more preferably 50 to 100 ° C.

  In addition to wax, a polyester having a low melting point (hereinafter also referred to as “low melting polyester”) can be used as a component capable of imparting releasability. For example, the low melting point is preferably one having a melting point Tm of about 70 to 90 ° C. Moreover, it is preferable that the weight average molecular weight Mw of low melting point polyester is about 3500-6500. The low melting point polyester is preferably a polymer of an aliphatic monomer. If the low-melting polyester satisfies at least one of these conditions, preferably two or more, the compatibility with the above-described polyester resin is particularly excellent, and the durability of the toner is improved. The toner releasability can be imparted without hindering. Further, since the melting point is relatively low, the low-temperature fixability can be improved.

In addition, components other than the binder resin, the colorant, and the release agent may be contained in the toner production raw material. Examples of such components include a charge control agent, a dispersant, and magnetic powder.
Specific examples of the charge control agent include benzoic acid metal salts, salicylic acid metal salts, alkyl salicylic acid metal salts, catechol metal salts, metal-containing bisazo dyes, nigrosine dyes, tetraphenylborate derivatives, and quaternary ammonium salts. , Alkyl pyridinium salts, chlorinated polyesters, nitrofunnic acid and the like.

Examples of the dispersant include metal soaps, inorganic metal salts, organic metal salts, and polyethylene glycol.
Specific examples of the metal soap include tristearic acid metal salts such as aluminum salts, distearic acid metal salts such as aluminum salts and barium salts, stearic acid metal salts such as calcium salts, lead salts, and zinc. Salts, linolenic acid metal salts such as cobalt salts, manganese salts, lead salts, zinc salts, octanoic acid metal salts such as aluminum salts, calcium salts, cobalt salts, etc., oleic acid metal salts such as calcium salts, Cobalt salts, etc., palmitic acid metal salts, eg, zinc salts, etc., naphthenic acid metal salts, eg, calcium salts, cobalt salts, manganese salts, lead salts, zinc salts, etc., resinate metal salts, eg, calcium salts, cobalt salts , Manganese lead salt, zinc salt and the like.
Examples of the inorganic metal salt and the organic metal salt include a cation of an element selected from the group consisting of metals of Group IA, Group IIA, and Group IIIA of the periodic table as a cationic component, and an anion Examples of the functional component include salts containing an anion selected from the group consisting of halogen, carbonate, acetate, sulfate, borate, nitrate, and phosphate.

Examples of the magnetic powder include magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, magnesium oxide, and other metal oxides such as Fe, Co, and Ni. The thing comprised with the magnetic material containing a magnetic metal etc. are mentioned.
In addition to the above materials, for example, zinc stearate, zinc oxide, cerium oxide, or the like may be used as an additive.

In the present invention, melt kneading of a plurality of types of binder resins can be performed using a closed kneader, a single or biaxial kneading extruder, a continuous two-roll kneader, or the like. Moreover, it is preferable that a plurality of types of binder resins to be used in the melt-kneading step are mixed with stirring in advance using a Henschel mixer or the like and mixed uniformly.
In the melt-kneading step, it is preferable to melt and knead at a temperature equal to or higher than the softening point or melting point of the resin having the highest softening point or melting point.
The kneaded resin thus obtained is cooled, pulverized, mixed with a release agent, a charge control agent, a pigment and the like with a Henschel mixer, etc., and similarly to the melt kneading of the binder resin, a sealed kneader, After mixing and kneading using a monoaxial or biaxial kneading extruder, continuous two-roll kneader, etc., cooling, coarsely pulverizing with a hammer mill, etc., then finely pulverizing with a jet mill etc., Further, after classification by an air classifier, the toner can be mixed with an external additive such as silica or titania in a Henschel mixer.

Prior to toner production, the following three polyesters A, B, and C were produced.
1-1. Production of Polyester A (Amorphous Polyester) Neopentyl glycol: 36 mol parts, ethylene glycol: 36 mol parts, 1,4-cyclohexanediol: 48 mol parts, dimethyl terephthalate: 90 mol parts, phthalic anhydride: 10 mol 1000 g of the mixture was put into a 2 liter four-necked flask equipped with a reflux condenser, a distillation tower, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer, and further an esterification condensation catalyst (titanium tetrabutoxide (TTB )): 1 g was added and heated.

At 180 ° C., the esterification reaction was allowed to proceed while the generated water and methanol were allowed to flow out of the distillation column. When water and methanol no longer flowed out of the distillation tower, the distillation tower was removed from the four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 666.6 Pa or less, the temperature was set to 200 ° C., and stirring was performed at a stirrer rotation speed: 150 rpm, whereby the free diol generated by the condensation reaction was discharged out of the system. The reaction product was designated as polyester A.
About obtained polyester A, it measured by the measuring method as described below.
In the measurement of the endothermic peak of the melting point using a differential scanning calorimeter, a clear peak that could be judged as the absorption peak of the melting point could not be confirmed. Polyester A had a softening point Tf of 111 ° C., a viscosity at 100 ° C. of 2.6 × 10 ⁴ Pa · s, a glass transition point Tg of 60 ° C., and a weight average molecular weight Mw of 1.3 × 10 ^4. It was.

1-2. Production of Polyester B (Amorphous Polyester) Neopentyl glycol: 36 mol parts, ethylene glycol: 36 mol parts, 1,4-cyclohexanediol: 48 mol parts, dimethyl terephthalate: 90 mol parts, phthalic anhydride: 10 mol 1000 g of the mixture in a part are put into a 2-liter four-necked flask equipped with a reflux condenser, a distillation column, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer, and an esterification condensation catalyst (titanium tetrabutoxide). (TTB)): 1 g was added and heated.

  At 180 ° C., the esterification reaction was allowed to proceed while the generated water and methanol were allowed to flow out of the distillation column. When water and methanol no longer flowed out of the distillation tower, the distillation tower was removed from the four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 400 Pa or less, the temperature was set to 220 ° C., and the stirring was performed at a stirrer rotational speed of 150 rpm, whereby the free diol generated by the condensation reaction was discharged out of the system, and the resulting reaction The product was designated as polyester B.

About obtained polyester B, it measured by the measuring method as described below.
An attempt was made to measure the endothermic peak of the melting point of polyester B obtained by a differential scanning calorimeter. As a result, a clear peak that could be judged to be an absorption peak of the melting point could not be confirmed. Polyester B had a softening point Tf of 142 ° C., a glass transition point Tg of 68 ° C., a melt viscosity at 100 ° C. of 1.2 × 10 ⁵ Pa · s, and a weight average molecular weight Mw of 3.6 × 10 ^4. It was.

1-3. Manufacture of polyester C (block polyester) A 2-liter four-necked flask is equipped with a reflux condenser, a distillation tower, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer. Polyester A: 70 mol parts, diol 1,4-butanediol as a component: 1000 g of a mixture of 15 mol parts of dimethyl terephthalate as a dicarboxylic acid component: 15 g of an esterification condensation catalyst (titanium tetrabutoxide (TTB)): 1 g And heated.

  At 200 ° C., the esterification reaction was allowed to proceed while water and methanol produced were discharged from the distillation column. When water and methanol no longer flowed out of the distillation tower, the distillation tower was removed from the four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 666.6 Pa or lower, the temperature is set to 220 ° C., and the stirring is performed at a stirrer rotational speed of 150 rpm, so that the free diol generated by the condensation reaction is discharged out of the system. The reaction product was polyester C.

About the obtained polyester C, it measured with the following measuring methods.
The center value Tmp of the endothermic peak of the melting point of polyester C as measured using a differential scanning calorimeter was 218 ° C., and the shoulder peak value Tms was 205 ° C. Moreover, from the differential scanning calorimetry curve obtained by the measurement, the heat of fusion Ef of the polyester C was 18 mJ / mg. Polyester C had a softening point Tf of 149 ° C., a melt viscosity at 100 ° C. of 1 × 10 ⁶ Pa · s, a glass transition point Tg of 64 ° C., and a weight average molecular weight Mw of 2.8 × 10 ⁴ .

2-1. Manufacture of Pigment Master Batch D Polyester A: 60% by mass, magenta pigment (Karmin 6B ECR-101 manufactured by Dainichi Seika Kogyo Co., Ltd.) 40% by mass was prepared using the flushing method. The obtained product was coarsely pulverized to a diameter of 2 mm to obtain a pigment master batch D.

2-2. Production of Pigment Master Batch E Polyester A: 30% by mass, polyester C: 30% by mass, magenta pigment (Karmin 6B ECR-101 manufactured by Dainichi Seika Kogyo Co., Ltd.) 40% by mass was prepared using the flushing method. The obtained product was coarsely pulverized to a diameter of 2 mm to obtain a pigment master batch E.

(Preparation of Toner 1)
Low melt viscosity amorphous polyester as polyester A: 70 parts by weight, high melt viscosity amorphous polyester as polyester B: 10 parts by weight, block polyester as polyester C: 20 parts by weight, pigment masterbatch D: 10 parts by weight, charging As control agent, chromium salicylate complex (Bontron E-81 manufactured by Orient Chemical Co., Ltd.): 1 part by weight, 3 parts by weight of release agent (carnauba wax: melting point 86 ° C.) were mixed using a 20 L Henschel mixer (Mitsui Mine). As a result, a mixture for toner production was obtained.
Next, this resin mixture was kneaded at a resin temperature of 107 ° C. using a twin-screw kneading extruder (Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled with a cooler. The temperature of the kneaded material immediately after the cooling step was 44 ° C.

Subsequently, the cooled kneaded material was coarsely pulverized to an average particle diameter of 1 to 2 mm, and then finely pulverized. A hammer mill was used for coarse pulverization of the kneaded product, and a jet mill (200AFG manufactured by Hosokawa Micron Corporation) was used for fine pulverization. The fine pulverization was performed at a pulverization air pressure: 500 kPa and a rotor rotation speed: 7000 rpm.
The pulverized material thus obtained was classified with an airflow diverter (manufactured by Hosokawa Micron Corporation, 100 ATP).
Next, using a 20 L type Henschel mixer (Mitsui Mine) on the obtained powder, as an external additive, negatively chargeable small particle size silica (RX200 average particle size 12 nm manufactured by Nippon Aerosil Co., Ltd.): 1 part by weight, Negatively chargeable large particle size silica (Silica RX50 average particle size: 40 nm, manufactured by Nippon Aerosil Co., Ltd.): 0.5 parts by weight and a number average particle obtained by mixing those subjected to a hydrophobic treatment by the surface treatment of hexamethyldisilazane A toner 1 having a diameter of 8.7 μm was obtained.
When the physical properties of the obtained toner 1 were measured by the following method, the average circularity R was 0.91. The acid value was 0.8 mgKOH / g. The average length of crystals in the toner was 0.7 μm.
Further, the fixing characteristics were measured by the following method, and the results are shown in Table 1.

(Evaluation method of toner characteristics)
1. Measurement method of softening point and melt viscosity Using a constant load extrusion type capillary rheometer (Flow Tester CFD-500D manufactured by Shimadzu Corporation), a measurement sample: 1 g is compression molded, a die hole diameter: 1 mm, a die length: 1 mm, The softening point was determined by the 1/2 method for determining the temperature at the time when 1/2 of the sample flowed out at an extrusion pressure of 1.96 MPa.
The melt viscosity was expressed in Pa · s at 100 ° C.

2. Measuring method of glass transition point (Tg) A glass transition point was measured using a differential scanning calorimeter (EXSTAR6000 DSC-220C manufactured by Seiko Instruments Inc.).
Preparation of measurement sample: Prepare a measurement sample by sealing 10 mg of sample in an aluminum sample container.
Measurement conditions: The temperature was raised at a measurement start temperature of 20 ° C., a measurement end temperature of 200 ° C., and a temperature increase rate of 10 ° C./min, and then a temperature decrease rate of 10 ° C./min to 20 ° C.
Thereafter, the temperature is increased to 200 ° C. at a rate of temperature increase of 10 ° C./min, and the temperature at the end of the endotherm corresponding to the glass transition point, that is, the shoulder position of the endothermic curve is set.

3. Method for Measuring Melting Point (Tm) The melting point was measured using a differential scanning calorimeter (EXSTAR6000 DSC-220C manufactured by Seiko Instruments Inc.).
Preparation of measurement sample: Prepare a measurement sample by sealing 10 mg of sample in an aluminum sample container.
Measurement conditions: The temperature was raised at a measurement start temperature of 20 ° C., a measurement end temperature of 300 ° C., and a temperature increase rate of 10 ° C./min, and then a temperature decrease rate of 10 ° C./min to 20 ° C.
Thereafter, the temperature was increased to 300 ° C. at a rate of temperature increase of 10 ° C./min, and the maximum peak temperature of the endotherm due to crystal melting at the second temperature increase was determined as the melting point Tm.

4). Measurement of Molecular Weight Distribution 5 mg of binder resin was dissolved in 5 g of tetrahydrofuran (THF), and a sample for GPC was prepared through a membrane filter having a pore size of 0.2 μm in order to remove THF-insoluble matter and contaminants. The sample thus prepared (THF soluble component) was measured by high performance liquid chromatography using a GPC column under the following conditions.
Column: GPC column (Showa Denko Shodex (GPC KF806M, KF802.5))
Column temperature: 30 ° C
Solvent: Tetrahydrofuran Flow rate: 1.0 ml / min
Detector: UV detector (detection wavelength 254 nm)
Standard sample: Monodisperse polystyrene standard sample (weight average molecular weight 580 to 3.9 million)

5). Measurement of average circularity of toner Using a flow type particle image analyzer (FPIA-2100 manufactured by Sysmex Corporation), the measurement is performed in a water dispersion system, and the projection of the toner particles to be measured with respect to the perimeter of the projected image of the toner particles to be measured The ratio of the circumference of a perfect circle having an area equal to the area of the image was expressed as a circularity.

6). Measurement of Toner Acid Value 2 g of resin is weighed into a 200 ml Erlenmeyer flask with stopper and dissolved in 30 ml of methyl ethyl ketone. To this solution, a 1% by mass phenolphthalein solution is added as a titration indicator, titrated with an alkali standard solution composed of 1/50 N potassium hydroxide-isopropyl alcohol solution, and the following formula (1) is calculated from the consumption of the alkali standard solution. The acid value was determined by
Acid value = N × F × (A−B) × M / C (1)
N: Normality of alkali standard solution
F: titer of alkali standard solution
A: Alkaline standard solution required for the test (ml)
B: Alkaline standard solution required for blank test (ml)
M: Molecular weight of potassium hydroxide (= 56.1)
C: Sample mass (g)

7). Average length of crystals in toner Toner was sandwiched between glass slides and melted at 180 ° C. to prepare an observation sample. The obtained sample for observation was measured with a polarizing microscope (Axiotech 30 manufactured by Zeiss).
8). Dispersion diameter of release agent The toner was embedded in a resin, and the slice was prepared by setting the cut thickness of the microtome to 0.20 μm. After staining with ruthenium tetroxide, a 5000 × image of this section was taken with a transmission electron microscope (H-700H, manufactured by Hitachi, Ltd.). The photograph image was taken in an image analyzer and the particle size distribution of the dispersed particle size was measured. When the dispersed particles were not perfectly spherical, the calculation was performed using the equivalent circle particle size.

9. Fixing evaluation method A fixing device is removed from a color laser printer (Seiko Epson LP-3000C), and a toner adhesion amount 0.4 mg / cm ² solid image is formed on paper (Fuji Xerox Office Supply PPC plain paper J). A 20 mm square area was formed at a position 10 mm from the front end of the paper, and this image was used as an image for fixing property evaluation.
Using a fixing unit for a color laser printer (KL-2010 manufactured by Konica), remove the coating means to apply silicone oil, pass 1000 sheets of non-printed paper (A4), and roll the roller surface. The silicone oil was removed from the fixing roll by cleaning with isopropyl alcohol. Further, every time the image for fixing property evaluation was passed through the fixing device, the fixing roll was cleaned with isopropyl alcohol, and further wiped dry with a cotton cloth, so that the surface of the fixing roll was free from silicone oil.
Next, the fixing roll temperature can be adjusted from 100 ° C. to 200 ° C., and the fixing property evaluation image is passed so that the heating roll side becomes the unfixed toner adhering surface, and fixing is performed under the condition that the nip passage time is 50 msec. did.

  While changing the surface temperature of the fixing roller step by step, pass an unfixed image and visually determine whether a portion of the image has been transferred to the fixing roller and then transferred to the paper again. did. When there was a shift to paper, the offset was present, when there was no offset, the offset was absent, and the temperature region where no offset occurred was defined as the offset good region. Further, the good offset region was 50 ° C or higher, the good offset region was 30 ° C or higher and lower than 50 ° C, and the good offset region was less than 30 ° C.

(Preparation of Toner 2)
Polyester A: 50 parts by weight as low melt viscosity amorphous polyester, Polyester B: 30 parts by weight as high melt viscosity amorphous polyester, Polyester C: 20 parts by weight as block polyester, resin 100 parts by weight, pigment master batch D: 10 parts by weight, chromium salicylate complex as a charge control agent (Bontron E-81 manufactured by Orient Chemical Industries): 1 part by weight, 3 parts by weight of release agent (carnauba wax: melting point 86 ° C.), 20 L type Henschel mixer (Mitsui And a mixture for toner production was obtained.

Next, this resin mixture was kneaded at a resin temperature of 109 ° C. using a twin-screw kneading extruder (Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled using a cooler. The temperature of the kneaded material immediately after the cooling step was 47 ° C.
Thereafter, in the same manner as in the production method of toner 1, pulverization and classification were performed, and then an external additive was added to obtain toner 2.

(Evaluation of toner characteristics)
When the physical properties of the obtained toner 2 were measured by the evaluation method described in Example 1, the average particle size of toner 2 was 8.6 μm, and the average circularity was 0.91. The acid value was 0.8 mgKOH / g. Further, the average length of the crystals in the toner 2 was 0.6 μm.
The fixing characteristics were measured by the evaluation method described in Example 1, and the results are shown in Table 1.

(Preparation of Toner 3)
Toner 3 was produced in the same manner except that the pigment master batch in Example 1 was changed to pigment master batch E.
(Evaluation of toner characteristics)
The average particle size of the obtained toner 3 was 8.5 μm. The average circularity R was 0.91. The acid value of the toner is O.D. It was 8 mgKOH / g. The average crystal length in the toner was 0.6 μm.

Comparative Example 1
(Preparation of Comparative Toner 1)
Polyester A as amorphous polyester: 80 parts by weight, polyester as block polyester: 20 parts by weight, pigment masterbatch D: 10 parts by weight, chromium salicylate complex as charge control agent (Bontron E-81 manufactured by Orient Chemical Industries): 1 Part by weight, carnauba wax (melting point: 86 ° C.) as a release agent: 3 parts by weight were mixed using a 20 L Henschel mixer (manufactured by Mitsui Mine) to obtain a mixture for toner production.
The obtained mixture was kneaded at a resin temperature of 106 ° C. using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled using a cooler. The temperature of the kneaded material immediately after the cooling step was 45 ° C.
Next, in the same manner as in Example 1, pulverization, classification, and addition of external additives were performed to prepare Comparative Toner 1.

(Evaluation of toner characteristics)
The physical properties of the obtained comparative toner 1 were measured by the evaluation method described in Example 1. As a result, the average particle size of the comparative toner 1 was 8.6 μm, and the average circularity was 0.91. The acid value was 0.8 mgKOH / g. Further, the average length of the crystals in Comparative Toner 1 was 1.5 μm. The average dispersed particle size of the release agent was 0.5 μm.
The fixing characteristics were measured by the evaluation method described in Example 1, and the results are shown in Table 1.

Comparative Example 2
(Preparation of Comparative Toner 2)
Polyester A: 75 parts by weight as low melt viscosity amorphous polyester, Polyester B: 5 parts by weight as high melt viscosity amorphous polyester, Polyester C: 20 parts by weight as block polyester, resin 100 parts by weight, pigment master batch D: 10 parts by weight, chromium salicylate complex as a charge control agent (Bontron E-81 manufactured by Orient Chemical Industries): 1 part by weight, 3 parts by weight of release agent (carnauba wax: melting point 86 ° C.), 20 L type Henschel mixer (Mitsui And a mixture for toner production was obtained.
Next, this resin mixture was kneaded at a resin temperature of 106 ° C. using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled using a cooler. The temperature of the kneading snout immediately after the cooling step was 49 ° C.
Next, in the same manner as in Example 1, pulverization, classification, and addition of external additives were performed to prepare Comparative Toner 2.

(Evaluation of toner characteristics)
The physical properties of the obtained comparative toner 2 were measured by the evaluation method described in Example 1. The comparative toner 2 had an average particle size of 8.3 μm and an average circularity of 0.91. The acid value was 0.8 mgKOH / g. The average length of the crystals in Comparative Toner 2 was 1.1 μm.
The fixing characteristics were measured by the evaluation method described in Example 1, and the results are shown in Table 1.

Comparative Example 3
(Preparation of Comparative Toner 3)
Polyester A: 45 parts by weight as low melt viscosity amorphous polyester, Polyester B: 35 parts by weight as high melt viscosity amorphous polyester, Polyester C: 20 parts by weight as block polyester, resin 100 parts by weight, pigment master batch D: 10 parts by weight, chromium salicylate complex as a charge control agent (Bontron E-81 manufactured by Orient Chemical Industries): 1 part by weight, 3 parts by weight of release agent (carnauba wax: melting point 86 ° C.), 20 L type Henschel mixer (Mitsui And a mixture for toner production was obtained.
Next, this mixture was kneaded at a resin temperature of 109 ° C. using a twin-screw kneading extruder (Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled using a cooler. The temperature of the kneaded material immediately after the cooling step was 49 ° C.
Thereafter, in the same manner as in the production method of the toner 1, pulverization and classification were performed, and then an external additive was added to obtain a comparative toner 3.

(Evaluation of toner characteristics)
When the physical properties of the obtained comparative toner 3 were measured by the evaluation method described in Example 1, the average particle size of the comparative toner 3 was 8.6 μm and the average circularity was 0.91. The acid value was 0.8 mgKOH / g. The average crystal length in Comparative Toner 3 was 0.6 μm.
The fixing characteristics were measured by the evaluation method described in Example 1, and the results are shown in Table 1.

Comparative Example 4
(Preparation of Comparative Toner 4)
Polyester A as the amorphous polyester: 70 parts by weight, Byron GM-440 (Toyobo's weight average molecular weight Mw: 15000, softening point: 145 ° C.) as the crystalline polyester: 30 parts by weight, pigment masterbatch D: 10 parts by weight, Chromium salicylate complex (Bontron E-81, manufactured by Orient Chemical Co., Ltd.) as a charge control agent: 1 part by weight, Carnauba wax: 3 parts by weight as a release agent, are mixed using a 20 L Henschel mixer (Mitsui Mine), A mixture for toner production was obtained.
The obtained mixture was kneaded at a resin temperature of 103 ° C. using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., TEM-41 type). The resin temperature is the temperature measured at the kneader head.
The kneaded product extruded from the extrusion port of the biaxial kneading extruder was cooled using a cooler. The temperature of the kneaded material immediately after the cooling step was 44 ° C.
Next, in the same manner as in Example 1, pulverization, classification, and addition of external additives were performed to prepare Comparative Toner 4.

(Evaluation of toner characteristics)
The physical properties of the obtained comparative toner 4 were measured by the evaluation method described in Example 1. As a result, the volume average particle size of the comparative toner 4 was 8.6 μm, and the average circularity was 0.91. The acid value was 6.2 mgKOH / g. The average crystal length in Comparative Toner 4 was 0.8 μm. The average dispersed particle size of the release agent was 1.5 μm.

Table 1
Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4
Average crystal length (μm) 0.7 0.6 0.6 1.5 1.1 0.6 0.8
Good offset range (° C) 155-205 160-210 155-210 155-180 150-190 170-210 135-160
Excellent Excellent Excellent Excellent Defect Defect Defect Defect

  The toner of the present invention comprises a crystalline polyester and an amorphous polyester, and the amorphous polyester is obtained by copolymerization of an amorphous block and a crystalline block component constituting the amorphous polyester. It is a block polyester that has a higher softening point than polyester, and the amorphous polyester is a low melt viscosity amorphous polyester and a high melt viscosity by kneading with a release agent using a high melt viscosity amorphous polyester. Since the viscosity can be increased by the presence of the non-crystalline polyester, the compatibility between the block polyester and the non-crystalline polyester can be increased, and the crystalline component can be dispersed small. As a result, it is possible to obtain a toner having excellent characteristics in which the crystalline polyester and the release agent are finely dispersed.

Claims (3)

In a toner used for developing an electrostatic latent image formed on an electrostatic latent image carrier to form an image, the binder resin is made of crystalline polyester and amorphous polyester, and the crystalline polyester is made of the non-crystalline polyester. A block polyester having a higher softening point than the amorphous polyester obtained by copolymerization of the amorphous block constituting the crystalline polyester and the crystalline block component, and the amorphous polyester has a plurality of different melt viscosities. A toner comprising: amorphous polyester. 2. The non-crystalline polyester contains a high melt viscosity amorphous polyester, and the proportion of the high melt viscosity amorphous polyester in the total polyester resin is 5% by mass to 30% by mass. Toner. In a method for producing a toner used to form an image by developing an electrostatic latent image formed on an electrostatic latent image carrier, a plurality of amorphous polyesters having different melt viscosities as amorphous polyesters and crystalline A polyester having a melting point of crystalline polyester is mixed by mixing a block polyester having a softening point higher than that of the amorphous polyester obtained by copolymerization of the amorphous block constituting the amorphous polyester and the crystalline block component. And a kneading agent at a temperature lower than the melting point of the crystalline polyester.