JP2005148527A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner having good cold offset and hot offset properties. <P>SOLUTION: In the toner comprising a resin A whose weight average molecular weight is 5,000-40,000 and a crystalline resin B having a crystalline block structure, the molecular weight of an amorphous block of the crystalline resin B is ≥1/2 of that of the resin A. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing toner used for image formation by an electrophotographic method in which an image formed on an electrostatic latent image carrier is developed to form an image.

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.
It has also been proposed to use a polyester with a low softening temperature in order to lower the fixing temperature. However, although the low-temperature fixability is improved by the polyester, it cannot be said that the offset resistance is sufficient.

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, 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 a part of these raw materials is previously melt-kneaded, There has been proposed a toner manufacturing method that prevents problems that occur when polyester is added (Patent Document 1).

  However, in the method described in Patent Document 1, 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, by using a high melting point block polyester containing a high melting point crystalline component and a low softening point amorphous polyester as a binder resin, high temperature offset does not occur due to the action of the high melting point block polyester, and fixing at a low temperature. However, when kneading a high melting point block polyester, a low softening point amorphous polyester, and a wax, a high melting point block polyester and a low softening point amorphous polyester may be used. Since the melting points are separated, a good kneaded state cannot be obtained.
For this reason, in order to melt the high melting point block polyester, if it is diluted and kneaded at a high temperature, the wax dispersion particle size becomes large, which adversely affects the durability characteristics. Further, when the additive such as wax is finely dispersed, when it is diluted and kneaded at a low temperature, the high melting point block polyester is not dispersed, and the high temperature offset characteristic is deteriorated.
JP 2002-328490 A

  In the present invention, a toner containing a plurality of binder resins has a good dispersion state of a release agent, a charge control agent, a pigment and the like, and particularly a high melting point block resin containing a high melting point crystal component and a low softening point. It is an object of the present invention to provide a toner having excellent fixability in which low temperature fixability in which a release agent is highly dispersed and high temperature offset does not occur when a crystalline resin is used in combination.

An object of the present invention is to provide a toner comprising a resin A having a weight average molecular weight of 5000 to 40000 and a crystalline resin B having a crystalline block structure, and the molecular weight of the amorphous block of the crystalline resin B is determined by the molecular weight of the resin A. It is possible to solve this problem by using a toner that is half or more of the above.
Further, in the toner, the molecular weight of the crystalline block of the resin B is 40000 or less.
The amorphous components of the resin A and the resin B are the toners having the same bonding structure.
Further, in the toner, the molecular weight ratio of the amorphous component to the crystalline component of the resin B is 1 or more.

The toner of the present invention is a toner composed of a resin A having a weight average molecular weight of 5000 to 40000 and a crystalline resin B having a crystalline block structure, and the molecular weight of the amorphous block of the crystalline resin B is equal to the molecular weight of the resin A. When the binder resin is formed by kneading the crystalline resin B having the crystalline block structure and the resin A and then cooling, the amorphous block is formed in the network structure of the crystalline block. Since the crystalline resin A is taken in, it prevents exudation at a low temperature from the network structure of the crystalline block and is sufficiently taken into the network structure, so that it has excellent characteristics that prevent both low temperature offset and high temperature offset. Toner can be provided.
Furthermore, the dispersed particle diameter of the release agent does not increase, and a toner having excellent high-temperature offset resistance and excellent durability and the like in which the release agent is finely dispersed can be obtained.
In the present invention, the weight average molecular weight is a value obtained by high-performance liquid chromatography using styrene as a standard sample using a GPC column, and the softening point is half of the sample flowing out by a constant load capillary extrusion rheometer. It is the value obtained from the temperature at the time of

  The toner of the present invention is a toner composed of a resin A having a plurality of different resins as binder resins, a weight average molecular weight of 5000 to 40000, and a crystalline resin B having a crystalline block structure. Since the molecular weight of the crystalline block is one-half or more of the molecular weight of the resin A, the amorphous resin incorporated in the network structure of the crystalline block does not easily exude, and the size of the network structure is moderate. A binder resin that is sufficiently incorporated into the network structure can be obtained, so that a toner capable of forming an excellent quality image with excellent low-temperature fixability and high-temperature offset property is provided. can do.

  The toner of the present invention is a non-crystalline resin having a crystalline block structure as a binder resin having a good high-temperature offset property containing a resin having a crystalline block structure in which a crystalline component and an amorphous component are blocked. By setting the molecular weight of the component to a specific value based on the molecular weight of the resin used in combination with the resin having the crystalline block structure, the amorphous resin is incorporated into the network structure of the crystalline block resin, and the low temperature characteristics and high temperature It has been found that a toner having good characteristics can be obtained.

  Further, the toner of the present invention is obtained by melting and kneading a resin having a crystalline block structure and an amorphous resin having a low softening point at a temperature equal to or higher than the melting point of the resin having a crystalline block structure, and then cooling. A network structure of the crystalline block resin is formed, and a structure that takes in the amorphous resin is formed, but since it is kneaded and cooled at a temperature equal to or higher than the melting point of the crystalline block resin, a uniform network structure is obtained from the molten state. It is reorganized and an amorphous resin is introduced inside.

In the toner of the present invention, when the molecular weight of the amorphous block of the crystalline resin is smaller than one half of the molecular weight of the amorphous resin, the size of the network structure of the crystalline block is small, and during the kneading It becomes difficult for the amorphous resin to enter the network structure.
If the ratio of the molecular weight of the amorphous component to the crystalline component in the resin B having a crystalline block component is smaller than 1, the network structure in the resin B becomes dense and the resin A is not easily taken into the network structure.

Furthermore, since the non-crystalline components in the resin A and the resin B have the same bonding structure, the compatibility between the resin A and the resin B is increased, so that the resin B is easily incorporated into the network structure of the resin B. , Low temperature offset and high temperature offset are good.
In the present invention, the same bonding structure means that each main chain has the same bonding structure and is manufactured using the same raw material, or a material that is further polymerizable with one resin. And a block structure containing a crystalline component is added.

  In the toner of the present invention, first, a resin B having a crystalline block structure and a resin A having a weight average molecular weight of 5000 to 40000 are kneaded, and then cooled, to form a network structure composed of the resin B having a block structure. Then, a structure for incorporating the resin A is formed. At this time, a uniform network structure is formed by kneading at a temperature exceeding the crystal melting point of the resin B.

In the toner of the present invention, if the weight average molecular weight of the resin A is less than 5000, the resin A tends to exude from the network structure, which causes high temperature offset. On the other hand, if the weight average molecular weight is larger than 40000, it is difficult to enter the network structure during kneading, which causes a low temperature offset.
The weight average molecular weight of the resin B having a crystalline block structure is preferably 10,000 to 150,000.
If the resin B is smaller than 10,000, it becomes difficult to form a network structure, which causes high temperature offset. If it is larger than 150,000, kneading becomes difficult, and the resin B tends to get entangled in the molecular chain, making it difficult for the resin A to enter the mesh and causing low temperature offset.

In addition, when a release agent is added and kneaded with the resin, the release agent is unlikely to enter the network structure. Therefore, when the resin C and the release agent that are compatible with the resin and have a glass transition point Tg higher than that of the resin A are mixed together, the dispersibility is improved.
This is considered that the added resin C pushes the release agent into the network structure in the resin B and the resin A kneaded resin.
That is, when the release agent is kneaded, the temperature of the kneaded resin is kneaded at a temperature higher than the softening point of the resin A. Therefore, the resin A having a glass transition point Tg lower than that of the resin C is higher than that of the resin C. It is soft.
In addition, since the resin C has a molecular weight larger than that of the resin A even when melted, it is difficult for the resin C to enter the network structure formed from the resin B and the resin A, and is considered to exist on the surface of the network structure.

As a result, when the resin C is added and kneaded, the resin A and the release agent are prevented from flowing out of the network structure again, so that a kneaded product in which the release agent is dispersed is obtained.
In particular, if the resin C is a resin having the same chemical structure as the resin B having a network structure, the compatibility with the resin B is high, and the effect of the addition of the resin C is further increased.

Further, as the resin C, a resin alone may be added, or a resin supplied as a pigment master batch composed of a pigment component and a resin necessary for toner preparation may be used.
Thereby, the dispersibility of the pigment in the toner can be enhanced.

When the dispersion of the release agent in the toner is poor, the release agent that exudes from the resin causes a decrease in the durability of the toner. Accordingly, a release agent having a functional group having a high affinity with the bond of the main chain of the resin is preferable so that the release agent easily enters a network structure.
In addition, it is preferable to easily enter a network structure at the time of kneading, and to exude quickly when heated and pressed by a fixing roll at the time of fixing, and those having a molecular weight smaller than that of the resin A are preferable.
It is considered that a toner having both high temperature offset property and durability can be obtained by the production method of the present invention as described above.

The toner of the present invention is cooled after the first kneading step in which the resin A and the resin B having a high melting point are heated and kneaded at a temperature equal to or higher than the melting point of the resin B, and the network structure of the resin B is separated after the reorganization. It is preferable to add a mold component or the like and knead in the second kneading step.
FIG. 1 is a diagram illustrating a first kneading step in the production of the toner of the present invention.
The resin to be kneaded is fed from the raw material inlet 2 of the mixing and kneading machine 1. The charged resin is mixed and kneaded by the rotation of the two screws 3a and 3b under heating, discharged from the discharge port 4 provided on the side opposite to the input port, and cooled by the cooler 5.
As shown in the temperature distribution curve 6, the mixing and kneading machine is set to be equal to or higher than the softening point (Tf) of the resin A over the entire region, and in the heating region at a predetermined distance from the charging port, the portion up to the screw head 7 is used. The temperature is higher than the melting point (Tm) of the resin B, and mixing and kneading is sufficiently performed.

FIG. 2 is a diagram for explaining a second kneading step in the production of the toner of the present invention.
The resin to be kneaded is fed from the raw material inlet 12 of the mixing and kneading machine 11. The charged resin is mixed and kneaded by the rotation of the two screws 13 a and 13 b under heating, discharged from the discharge port 14 provided on the side opposite to the charging port, and cooled by the cooler 15.
As shown in the temperature distribution curve 16, the mixing and kneading machine is set to be equal to or higher than the softening point (Tf) of the resin A over the entire region. Mixing and kneading is performed at a temperature lower than the softening point of the resin C, and smooth discharge from the mixing and kneading machine is performed near the discharge port 14 at a higher temperature.

The first kneading step in the present invention can be performed using a closed kneader, a uniaxial 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 second kneading step, similarly to the first kneading step, after mixing and kneading using a closed kneader, a single or biaxial kneading extruder, a continuous two-roll kneader, etc., To be cooled.
The obtained kneaded material is coarsely pulverized, then finely pulverized by a jet mill or the like, further classified by an airflow classifier, and then mixed with an external additive such as silica or titania in a Henschel mixer to obtain a toner. The

Hereinafter, the components of the toner of the present invention will be described.
The resin A having a weight average molecular weight of 5000 to 40000 and the crystalline resin B having a crystalline block structure can be an amorphous polyester and a block polyester having a higher melting point than that.
Polyester has a softening point at a relatively low temperature and is excellent in properties such as environmental resistance. However, other resin components may be used in combination with polyester.
When used in combination, the polyester content 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. Block polymers are obtained by transesterification of crystalline and amorphous blocks.
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 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 used for dispersibility of colorants, release agents, charge control agents, etc. constituting the toner, kneadability of the kneaded product during toner production, fixing properties such as low-temperature fixability of the toner, and transparency. It is a component that contributes to improving functions such as mechanical properties such as elasticity and mechanical strength, 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 amorphous polyester is preferably 5 × 10 ³ to 4 × 10 ⁴ , and more preferably 6 × 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 amorphous polyester is preferably 40 to 75 ° C, 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 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 is 1 of the sample when measured using a constant load extrusion type capillary rheometer under the conditions of sample amount: 1 g, die hole diameter: 1 mm, die length: 1 mm, extrusion pressure: 1.96 MPa. / 2 can be obtained as the temperature of T _1/2 , which is the temperature at which it flows out.

Hereinafter, components constituting the crystalline block will be described.
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 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} 1.5 × 10 ⁵ , and 1.2 × 10 ⁴ to 1 More preferably, it is 5 × 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 1.5 × 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 decreases, and the amount of heat required for fixing increases.

  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.
As for the softening point Tf, a constant load extrusion type capillary rheometer was used, and a sample amount: 1 g, a die hole diameter: 1 mm, a die length: 1 mm, an extrusion pressure: 1.96 Mpa, a half of the sample flowed out. This is performed by the 1/2 method for obtaining the temperature at the time of the above.

  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 is obtained as a binder resin by copolymerization of an amorphous polyester having a specific molecular weight range, and an amorphous block constituting the amorphous polyester and a crystalline block component. A toner having a predetermined characteristic can be obtained by using the amorphous polyester block polyester and the amorphous polyester in combination.
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 the present invention, the block polyester containing the above high-melting crystalline block, and an amorphous polyester having a lower softening point and a lower weight average molecular weight than that, and from the softening point of the amorphous polyester. Is characterized in that a third resin having a high softening point is contained in the second kneading step.
As the third resin, various resins can be used as long as they satisfy the softening point. However, compatibility with other binder resins by using a resin having a molecular weight distribution different from that of amorphous polyester. Can be increased, which is preferable.
Specifically, a glass transition temperature obtained by changing the esterification reaction conditions of the amorphous polyester and a softening point higher than that of the amorphous polyester resin previously kneaded can be used.

In addition, the third resin added in the second kneading step may be added alone, but a pigment master batch in which a pigment is dispersed, and further added with other components such as a charge control agent are used. May be.
Thus, by using a pigment master batch or the like, these components can be finely dispersed, and the toner characteristics can be improved.

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 release agent to which the toner of the present invention is added will be described. The content of the release agent is preferably 0.5 to 3% by mass in the toner, and more than 3% by mass is not preferable because the transparency of the image may be inhibited.

  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, the mixing and kneading of the binder resin can be performed using a closed kneader, a uniaxial 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 mixing and kneading step, it is preferable to melt and knead the resin 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.
The present invention will be described below with reference to examples and comparative examples.

Example 1
Prior to toner production, the following polyesters 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 in a part was added to 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 an esterification condensation catalyst (titanium tetrabutoxide (TTB) ): Added with 1 g.
The contents of the flask were heated, and the esterification reaction was allowed to proceed while allowing water and methanol produced at 180 ° C. to flow out of the distillation tower.

  When water and methanol no longer flowed out of the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 0.67 kPa 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, and the result was obtained. The reaction product was designated as polyester a.

About the obtained polyester a, it tried to measure the endothermic peak of melting | fusing point with a differential scanning calorimeter. As a result, a sharp peak that could be determined to be an absorption peak at the melting point could not be confirmed. Polyester a had a softening point Tf of 111 ° C., a glass transition point Tg of 60 ° C., and a weight average molecular weight Mw of 1.3 × 10 ⁴ .

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 was added to 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 an esterification condensation catalyst (titanium tetrabutoxide (TTB) ): Added with 1 g.
While the contents were heated and water and methanol produced at 180 ° C. were allowed to flow out of the distillation tower, the esterification reaction was allowed to proceed.
When water and methanol no longer flowed out of the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. In a state where the pressure in the system is reduced to 2.67 kPa or less, the temperature is set to 200 ° C., and stirring is performed at a stirrer rotation speed: 150 rpm, thereby discharging the free diol generated by the condensation reaction to the outside of the system. The reaction product was designated as polyester b.

For the obtained polyester b, an attempt was made to measure the endothermic peak of the melting point with a differential scanning calorimeter. As a result, a sharp peak that could be determined to be an absorption peak at the melting point could not be confirmed. Polyester b had a softening point Tf of 95 ° C., a glass transition point Tg of 50 ° C., and a weight average molecular weight Mw of 0.5 × 10 ⁴ .

1-3. Production of Polyester c (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 was added to 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 an esterification condensation catalyst (titanium tetrabutoxide (TTB) ): Added with 1 g.
While the contents were heated and water and methanol produced at 180 ° C. were allowed to flow out of the distillation tower, the esterification reaction was allowed to proceed.
When water and methanol no longer flowed out of the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 0.53 kPa or less, the temperature is set to 220 ° C., and stirring is performed at a stirrer rotation speed: 150 rpm, thereby discharging free diol generated by the condensation reaction to the outside of the system. The reaction product was designated as polyester B.

About the obtained polyester c, it tried to measure the endothermic peak of melting | fusing point with a differential scanning calorimeter. As a result, a sharp peak that could be determined to be an absorption peak at the melting point could not be confirmed. Polyester c had a softening point Tf of 130 ° C., a glass transition point Tg of 63 ° C., and a weight average molecular weight Mw of 3.8 × 10 ⁴ .

1-4. Production of polyester d (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 was added to 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 an esterification condensation catalyst (titanium tetrabutoxide (TTB) ): Added with 1 g.
While the contents were heated and water and methanol produced at 180 ° C. were allowed to flow out of the distillation tower, the esterification reaction was allowed to proceed.
When water and methanol no longer flowed out of the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 0.53 kPa or less, the temperature was set to 210 ° 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 d.

An attempt was made to measure the endothermic peak of the melting point of the obtained polyester d using a differential scanning calorimeter. As a result, a sharp peak that could be determined to be an absorption peak at the melting point could not be confirmed. Polyester d had a softening point Tf of 122 ° C., a glass transition point Tg of 62 ° C., and a weight average molecular weight Mw of 2.1 × 10 ⁴ .

1-5. Manufacture of polyester e (block polyester) A reflux condenser, a distillation tower, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer were attached to a 2-liter four-necked flask. And 1,4-butanediol as a diol component: 15 parts by mole of dimethyl terephthalate as a dicarboxylic acid component: 1000 g, esterification condensation catalyst (titanium tetrabutoxide (TTB)): 1 g Was placed in a 2-liter 4-neck flask.

While the contents were heated and water and methanol produced at a temperature of 200 ° C. were allowed to flow out of the distillation tower, the esterification reaction was allowed to proceed.
When water and methanol no longer flowed out of the distillation column, the distillation column was removed from the 2-liter four-necked flask and connected to a vacuum pump. With the pressure in the system reduced to 0.67 kPa or less, the temperature is set to 220 ° C., and stirring is performed at a stirrer rotation speed: 150 rpm, thereby discharging the free diol generated by the condensation reaction to the outside of the system. The reaction product was designated as polyester e.
Polyester e had a softening point Tf of 149 ° C., a glass transition point Tg of 64 ° C., and a weight average molecular weight Mw of 2.8 × 10 ⁴ .

1-6. Production of polyester f (block polyester) Polyester f was synthesized in the same manner except that polyester a used in the production of polyester e was changed to polyester b. Polyester f had a softening point Tf of 120 ° C., a glass transition point Tg of 58 ° C., and a weight average molecular weight Mw of 1.3 × 10 ⁴ .

1-7. Production of polyester g (block polyester) Polyester g was synthesized in the same manner except that polyester a used in the production of polyester e was changed to polyester d.
Moreover, the softening point Tf of the polyester g was 171 ° C., the glass transition point Tg was 67 ° C., and the weight average molecular weight Mw was 4.5 × 10 ⁴ .

2-1. Manufacture of a pigment masterbatch Polyester a: It prepared using the flushing method by the compounding ratio of 60 mass% and a phthalocyanine pigment (Daiichi Seika Kogyo ECB-301) 40 mass%. This was coarsely pulverized to a diameter of about 2 mm to obtain a pigment master batch h.

(Preparation of Toner 1)
85 parts by weight of polyester a as an amorphous polyester and 15 parts by weight of polyester e as a block polyester were mixed using a 20 L type Henschel mixer (manufactured by Mitsui Mining) to obtain a resin mixture for producing a binder resin.
Next, the resin mixture was kneaded at a kneading temperature (T1) of 250 ° C. using a twin-screw kneading extruder (manufactured by Toshiba Machine Co., Ltd., TEM-41 type). Coarsely pulverized to 2 mm.

  Next, 1: 100 parts by weight of roughly pulverized resin, 10 parts by weight of pigment master batch h, chromium salicylate complex as a charge control agent (Bontron E-81 manufactured by Orient Chemical Industries), 1 part by weight, and carnauba wax (wax as a wax) Molecular weight 850): 3 parts by weight were mixed using a 20 L type Henschel mixer (Mitsui Mine) to obtain a raw material for toner production.

  Next, this raw material mixture was kneaded using a twin-screw kneading extruder (Toshiba Machine Co., Ltd., TEM-41 type) at a kneading temperature (T2) of 110 ° C., and the kneaded material extruded from the extrusion port was Cooled using a cooler.

  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 under the conditions of pulverization air pressure: 500 kPa and rotor rotation speed: 7000 rpm. The pulverized material thus obtained was classified with an airflow diverter (manufactured by Hosokawa Micron Corporation, 100 ATP).

Furthermore, the external additive was mixed using a 20 L type Henschel mixer (Mitsui Mine). As external additives, negatively chargeable small particle size silica (Nippon Aerosil Co., Ltd. RX200 average particle size: 12 nm): 1 part by weight, negatively chargeable large particle size silica (Nippon Aerosil Co., Ltd. RX50 average particle size: 40 nm) : 0.5 part by weight and titanium oxide (Nihon Aerosil Co., Ltd. STT-30S average particle diameter: 20 nm): 0.5 part by weight were used. The negatively chargeable silica, that is, the negatively chargeable small particle size silica and the negatively chargeable large particle size silica were subjected to hydrophobic treatment by surface treatment with hexamethyldisilazane.
The number average particle diameter of the obtained toner 1 was 7.5 μm.

(Evaluation method of toner characteristics)
1. Method of measuring softening point Using a constant load extrusion type capillary rheometer (Shimadzu Corporation flow tester CFD-500D), a measurement sample: 1 g is compression molded, die hole diameter: 1 mm, die length: 1 mm, extrusion pressure: 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 1.96 MPa.

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). 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, using a fixing device from which the silicone oil was removed from the surface of the fixing roll, the image for fixing property evaluation was passed so that the heating roller side would be an unfixed toner adhering surface and fixed under the condition of a nip passage time of 50 msec. .
The fixing evaluation image is a color laser printer (Seiko Epson LP-3000C), and a so-called solid image is formed by uniformly attaching toner on plain paper (Fuji Xerox Office Supply J paper). The image forming conditions are adjusted so that the toner adhesion amount in a solid image is 0.4 mg / cm ^2, and then a solid image is formed in a 20 mm square region at a position 10 mm from the leading edge of the paper. It was set as the image for evaluation.
A temperature range having a width of 40 ° C. or higher was evaluated as “good”, and a temperature range width of less than 40 ° C. was determined as “not good”.

6). Durability test method Using a color laser printer (Seiko Epson LP-3000C), a 5% image was formed on plain paper (J paper manufactured by Fuji Xerox Office Supply Co., Ltd.), and a print durability test of 6000 sheets was conducted. And evaluated by the number of printable sheets.

(Preparation of Toner 2)
Toner 2 was prepared in the same manner as in Example 1 except that polyester c: 90 parts by weight of amorphous polyester and polyester g: 10 parts by weight as block polyester were used as raw materials for preparation of toner 1.
The obtained toner 2 was evaluated by the evaluation method described in Example 1, and the evaluation results are shown in Table 1.

Comparative Example 1
(Preparation of Comparative Toner 1)
Comparative toner 1 was prepared in the same manner as in Example 1 except that the amorphous polyester was used as the raw material for preparation of toner 1 and the polyester f was used in an amount of 85 parts by weight and the polyester f was used as a block polyester. Evaluation was performed by the evaluation method described in Example 1, and the evaluation results are shown in Table 1.

Comparative Example 2
(Preparation of Comparative Toner 2)
Comparative toner 2 was prepared in the same manner as in Example 1 except that in the raw material for preparation of toner 1, the polyester c: 85 parts by weight of the amorphous polyester and the polyester e: 15 parts by weight as the block polyester were used. Evaluation was performed by the evaluation method described in Example 1, and the evaluation results are shown in Table 1.

Table 1
Amorphous resin Block resin Good offset area Number of printable sheets
Molecular weight of amorphous part (° C)
Example 1 13000 13000 150-200 Good 7000
Example 2 38000 21000 150-200 Good 6000
Comparative Example 1 13000 5000 150-180 Not 4000
Comparative Example 2 38000 13000 180-210 Not 6000

  The toner of the present invention is a toner composed of a resin A having a plurality of different resins as binder resins, a weight average molecular weight of 5000 to 40000, and a crystalline resin B having a crystalline block structure. Since the molecular weight of the functional block is one half or more of the molecular weight of the resin A, the resin A taken into the network structure of the crystalline block of the resin B formed after mixing and melting and kneading both is easily exuded. In addition, the size of the network structure becomes appropriate, and a binder resin sufficiently incorporated into the network structure can be obtained, so that the low-temperature fixability, high-temperature offset property, etc. are good, and the quality is excellent. In addition, it is possible to provide a highly durable toner capable of forming a continuous image.

FIG. 1 is a diagram for explaining a first kneading step in the production of the toner of the present invention. FIG. 2 is a diagram for explaining a second kneading step in the production of the toner of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mixing kneader, 2 ... Raw material inlet, 3a, 3b ... Screw, 4 ... Discharge port, 5 ... Cooler, 6 ... Temperature distribution curve, 7 ... Head, 11 ... Mixing kneader, 12 ... Raw material inlet, 13a, 13b ... screw, 14 ... discharge port, 15 ... cooler, 16 ... temperature distribution curve, 17 ... head

Claims (4)

In a toner comprising a resin A having a weight average molecular weight of 5000 to 40000 and a crystalline resin B having a crystalline block structure, the molecular weight of the amorphous block of the crystalline resin B is at least one half of the molecular weight of the resin A. Toner. The toner according to claim 1, wherein the crystalline block of the resin B has a molecular weight of 40,000 or less. 3. The toner according to claim 1, wherein the amorphous components of the resin A and the resin B have the same bond structure. The toner according to claim 1, wherein the molecular weight ratio of the amorphous component to the crystalline component of the resin B is 1 or more.

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