JP2008224976A - Electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which has satisfactory low-temperature fixability and anti-blocking property and does not cause image deterioration even when storing a fixed image at high temperature for a long term; to provide an electrostatic charge image developer using the electrostatic charge image developing toner; and to provide a toner cartridge, a process cartridge and an image forming apparatus. <P>SOLUTION: The electrostatic charge image developing toner comprises a binder resin including a crystalline polyester resin and an amorphous polyester resin and a colorant, wherein the crystalline polyester resin is a polyester resin obtained by polymerizing an acid component and an alcohol component including two kinds of diols which have the number of carbon of 6 to 20 and have the different number of carbons respectively, and the ratio (A/B) of the constitutional molar ratio A (mol%) of the diol of the smaller number side of two kinds of diols having the different number of carbons to the constitutional molar ratio B (mol%) of the diol of the larger number side lies in the range of 10/90 to 40/60. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a process cartridge, and an image forming apparatus.

  Many methods are already known as electrophotographic methods. In general, a latent image is electrically formed by various means on the surface of a photoconductor (image holding member) using a photoconductive substance, and the formed latent image is transferred to an electrostatic charge developing toner (hereinafter referred to as “static toner”). The toner image on the surface of the photoconductor is transferred to the surface of a transfer medium such as paper with or without an intermediate transfer body. Then, a fixed image is formed through a plurality of steps of fixing the transferred image by heating, pressing, heating and pressing, solvent vapor, or the like. The toner remaining on the surface of the photoreceptor is cleaned by various methods as necessary, and is again subjected to the above-described plurality of steps.

  As a fixing technique for fixing the transferred image transferred on the surface of the transfer target, a hot roll fixing in which the transfer target with the toner image transferred is inserted between a pair of rolls consisting of a heating roll and a pressure roll and fixed. The law is common. In addition, as the same type of technology, one in which one or both of the rolls are replaced with a belt is also known. These techniques can obtain a fast and robust fixed image compared to other fixing methods, have high energy efficiency, and are less harmful to the environment due to volatilization of solvents and the like.

  In recent years, as a toner used for the developer used here, as a method for intentionally controlling the toner shape and the surface structure, a toner production method by an emulsion polymerization aggregation method has been proposed (for example, Patent Document 1). 2). In general, a resin dispersion is prepared by emulsion polymerization or the like, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared, and the resin dispersion and the colorant dispersion are mixed to correspond to the toner particle size. In the production method, the aggregated particles are formed and then heated to fuse and coalesce the aggregated particles.

  Further, it has already been known that, in the toner by the emulsion polymerization aggregation method as described above, by using a binder resin containing a crystalline resin and an amorphous resin, the fixing temperature of the toner can be lowered and good image formation can be obtained. It has been. However, if the toner-fixed image is stored for a long time in a high-temperature environment such as a car in summer, the image strength becomes weak due to recrystallization of the crystalline resin contained in the fixed toner. There is a problem that cracks are likely to occur when the sheet is bent, and good image quality cannot be maintained.

As a means for improving the low-temperature fixability and mechanical properties of the toner, for example, a method of containing a crystalline polyester resin having a melting point and a low softening point using 1,6-hexanediol as a main component as an alcohol component is known. (For example, see Patent Documents 3 and 4).
Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 Japanese Patent Laid-Open No. 2004-226569 JP 2005-321747 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic charge developing toner having good low-temperature fixability and anti-blocking properties and that does not cause image deterioration even when a fixed image is stored at a high temperature for a long period of time. And a toner cartridge, a process cartridge, and an image forming apparatus.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1 has a binder resin containing a crystalline polyester resin and an amorphous polyester resin, and a colorant.
The crystalline polyester resin is a polyester resin obtained by polymerizing an acid component and an alcohol component containing two kinds of diols having 6 to 20 carbon atoms and different carbon numbers,
The ratio of the constituent molar ratio A (mol%) of the diol having the smaller carbon number to the constituent molar ratio B (mol%) of the diol having the larger carbon number of the two diols having different carbon numbers. (A / B) is an electrostatic image developing toner having a range of 10/90 to 40/60.

  The invention according to claim 2 is a mass ratio (C) between the content C of the crystalline polyester resin and the content D of the amorphous polyester resin in the binder resin of the toner for developing an electrostatic charge image according to claim 1. / D) is a toner for developing electrostatic images having a range of 10/90 to 30/70.

  The invention according to claim 3 is the electrostatic image developing toner in which the melting point of the crystalline polyester resin in the electrostatic image developing toner according to claim 1 or 2 is in the range of 70 to 90 ° C.

  The invention according to claim 4 is the electrostatic charge image according to any one of claims 1 to 3, wherein the endothermic amount obtained from the endothermic peak in the differential thermal analysis based on ASTM D3418-8 is in the range of 20 to 40 mJ / mg. Development toner.

  The invention according to claim 5 is an electrostatic charge image developer, comprising toner, wherein the toner is the electrostatic charge image developing toner according to any one of claims 1 to 4.

  The invention according to claim 6 is a toner cartridge that contains at least toner, and the toner is the electrostatic image developing toner according to any one of claims 1 to 4.

  The invention according to claim 7 is a process cartridge including at least a developer holder and containing the electrostatic charge image developer according to claim 5.

  According to an eighth aspect of the present invention, there is provided an image carrier, a developing unit that develops an electrostatic image formed on the image carrier as a toner image with a developer, and a toner image formed on the image carrier. An image forming apparatus comprising: a transfer unit that transfers onto a transfer member; and a fixing unit that fixes a toner image transferred onto the transfer member, wherein the developer is the electrostatic charge image developer according to claim 5. Device.

According to the first aspect of the present invention, the electrostatic charge developing toner has good low-temperature fixability and anti-blocking property and does not cause image deterioration even when a fixed image is stored at a high temperature for a long period of time. Can be provided.
According to the second aspect of the present invention, the effect of improving the toner image strength when the specific crystalline polyester resin is used can be effectively exhibited while maintaining the low-temperature fixability.
According to the third aspect of the invention, the low-temperature fixability is good, and at the same time, the occurrence of toner blocking can be suppressed even if the crystallinity is lowered.
According to the invention of claim 4, it is possible to suppress a decrease in toner image strength after high-temperature storage while maintaining the characteristics of the crystalline polyester resin.
According to the fifth aspect of the invention, it is possible to provide an electrostatic charge developer that has good low-temperature fixability and blocking resistance and that does not cause image deterioration even when a fixed image is stored at a high temperature for a long period of time.
According to the sixth aspect of the invention, it is possible to supply toner for developing an electrostatic charge that has good low-temperature fixability and anti-blocking property and does not cause image deterioration even when a fixed image is stored at a high temperature for a long period of time. This makes it easy to maintain the above characteristics.
According to the invention of claim 7, it is easy to handle an electrostatic charge developer that has good low-temperature fixability and anti-blocking property and that does not cause image deterioration even when a fixed image is stored at a high temperature for a long period of time. Therefore, adaptability to image forming apparatuses having various configurations can be enhanced.
According to the eighth aspect of the present invention, it is possible to form an image without causing deterioration of the fixed image even under low temperature fixing conditions and when stored at a high temperature for a long time.

Hereinafter, the present invention will be described in detail.
<Toner for electrostatic image development>
The toner for developing an electrostatic charge image of the present invention has a binder resin containing a crystalline polyester resin and a colorant, and the crystalline polyester resin has an acid component and a carbon number of 6 to 20, respectively. The component molar ratio A (mol%) of the diol having the smaller carbon number of the two diols having different carbon numbers is obtained by polymerizing alcohol components containing two different diols having different carbon numbers. ) And the constituent molar ratio B (mol%) of the diol having the larger carbon number (A / B) is in the range of 10/90 to 40/60.

  As described above, in a toner containing a crystalline resin as a binder resin, particularly when the crystalline resin has high crystallinity, when the fixed image is stored in a high temperature environment, the toner image may be cracked against bending. is there. This is presumably because the crystallization of the crystalline resin proceeds due to heating, so that the crystalline portion is easily separated from other portions in the toner, and this crystalline portion becomes more brittle.

  For this reason, it is necessary to reduce the crystallinity (crystallinity) of the crystalline resin used for the toner binder resin. However, when the crystallinity of the crystalline resin is simply lowered, the melting point of the toner itself is lowered, and blocking occurs when the toner is left at a high temperature for a long time, so that developability is deteriorated. Further, the offset resistance at high temperatures is weakened, and hot offset may occur when the toner is fixed on the image support (paper).

Accordingly, the inventors focused on the crystalline polyester resin and searched for a crystalline polyester resin that can lower the crystallinity while maintaining a high melting point when it is made into a toner.
As a result, the alcohol component constituting the crystalline polyester resin contains two kinds of diols having 6 to 20 carbon atoms and different carbon numbers, and the constituent molar ratio of the two kinds of diols is set within a certain range. It has been found that the crystallinity can be reduced without lowering the melting point itself of the crystalline polyester resin, and good image retention can be obtained even during long-term storage at high temperatures while maintaining good low-temperature fixability. It was. The low temperature fixing means fixing the toner by heating at about 120 ° C. or less.

Hereinafter, the specific configuration and the production method of the electrostatic charge developing toner of the present invention will be described in detail with reference to embodiments.
The toner according to the exemplary embodiment includes a binder resin including an amorphous polyester resin and a crystalline polyester resin, and a colorant.

(Crystalline polyester resin)
The toner in the present exemplary embodiment can maintain toner blocking resistance and image storage stability while maintaining low-temperature fixability by including a crystalline polyester resin in the binder resin.
In the present embodiment, the crystalline polyester resin refers to having a clear endothermic peak, not a stepwise endothermic amount change in differential scanning calorimetry (DSC). Further, the endothermic peak may show a peak having a width of 40 to 50 ° C. when the toner is used. In the case of a polymer obtained by copolymerizing other components with respect to the crystalline polyester main chain, if the other components are 50% by mass or less, this copolymer is also called a crystalline polyester resin.
Hereinafter, although the preferable example of crystalline polyester resin is shown, it is not limited to what is shown here.

  The crystalline polyester resin is a specific polyester resin synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the following description, in the polyester resin, the component that was an acid component before the synthesis of the polyester resin is referred to as “acid-derived component”, and the component that was the alcohol component before the synthesis of the polyester resin is referred to as “alcohol. “Derived components”.

-Acid-derived components-
Examples of the acid for forming the acid-derived constituent component include various dicarboxylic acids. As the main acid-derived constituent component in the crystalline polyester resin, an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid are desirable. The group dicarboxylic acid is preferably a linear carboxylic acid.

Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, 3,3′-thiodipropionic acid and the like, or lower alkyl esters and acid anhydrides thereof may be mentioned, but not limited thereto.
Among these, considering availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable. In particular, in order to obtain the effect of the present invention, it is desirable to use one having a large carbon number with respect to two kinds of diols as alcohol components described later.

  In this embodiment, aromatic dicarboxylic acid may be copolymerized. For example, terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, etc., among which terephthalic acid, isophthalic acid, t-butylisophthalic acid These alkyl esters are preferable in terms of availability, easy formation of easily emulsifiable polymers, and the like. The copolymerization amount is preferably 10 constituent mol% or less.

  In the present specification, “constituent mol%” means 1 unit each of the acid-derived constituent component in the entire acid-derived constituent component in the polyester resin, or the alcohol constituent component in the entire alcohol-derived constituent component described later. Percentage when (mol).

  Examples of the acid-derived constituent component include the above-mentioned aliphatic dicarboxylic acid (main component) -derived constituent component and aromatic dicarboxylic acid (copolymerization component) -derived constituent component, dicarboxylic acid-derived constituent component having a double bond, and sulfonic acid. A constituent component such as a constituent component derived from a dicarboxylic acid having a group may be contained.

  In addition to the components derived from dicarboxylic acids having a double bond, the components derived from lower alkyl esters or acid anhydrides of dicarboxylic acids having a double bond are included in the components derived from dicarboxylic acids having a double bond. included. Further, the dicarboxylic acid-derived constituent component having a sulfonic acid group is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a sulfonic acid group, in addition to a constituent component derived from a dicarboxylic acid having a sulfonic acid group. Components are also included.

  A dicarboxylic acid having a double bond can be suitably used in order to prevent hot offset at the time of fixing since the entire resin can be cross-linked using the double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

The content of these dicarboxylic acid-derived components having double bonds in the total acid-derived components is preferably 10 component mol% or less.
When the content exceeds 10 component mol%, the crystallinity of the crystalline polyester resin may be lowered, the melting point may be lowered, and the image storage stability may be deteriorated.

  A dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when the particles are prepared by emulsifying or suspending the entire resin in water, if the sulfonic acid group is present, the resin can be emulsified or suspended without using a surfactant as described later. Examples of the dicarboxylic acid having a sulfonic acid group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt is preferable from the viewpoint of cost.

When the dicarboxylic acid-derived component having the sulfonic acid group is contained in the polymer, the content of the dicarboxylic acid-derived component having the sulfonic acid group in the total acid-derived component is 5 component mol% or less. It is preferable. Moreover, it is more preferable to use the content within a range of 3 constituent mol% or less.
When the content exceeds 5 component mol%, the hydrophilicity of the polyester resin increases, and the chargeability of the toner under high humidity may deteriorate. Although not necessarily used as a copolymerization component, it may be used to assist emulsification of the resin.

-Alcohol-derived components-
In the present embodiment, for the purpose of reducing the crystallinity without lowering the melting point of the crystalline polyester resin, it is necessary to perform polymerization using an alcohol component containing two diols having different carbon numbers.
In the case of crystalline polyester resins having the same acid component, the melting point, softening point, and crystallinity generally increase as the carbon number of the diol contained in the alcohol component increases. On the other hand, in order to reduce the crystallinity, it is effective to introduce a random structure in the molecular chain to some extent. However, in this case, the melting point also decreases as the crystallinity decreases. In addition, when a random structure is introduced into the molecular chain to some extent, the molecular chain is likely to move, and the dispersibility of the crystalline polyester resin in the toner may be deteriorated (creating a domain structure).

As a result of diligent studies to reduce the crystallinity while maintaining the melting point, the present inventors have determined that an alcohol composed of two diols having different carbon numbers when the diol has a certain carbon number range. It discovered that the said effect was acquired by applying a component. This is due to the effect of the diol having a large number of carbon atoms, and the melting point and softening point are maintained to such an extent that toner blocking does not occur. It is considered that the crystallinity is lowered due to the local random structure of the diol having a small carbon number, while maintaining the regularity of the molecule in the crystalline part including the diol as a whole.
When one kind of diol is used as the alcohol component, the crystallinity of the crystalline polyester resin moves together with the melting point and the softening point, and thus the above-described effects cannot be obtained.

The two types of diols to be the alcohol-derived constituent components need to have 6 to 20 carbon atoms, are preferably aliphatic diols, and more preferably linear aliphatic diols.
When the aliphatic diol is branched, the crystallinity of the crystalline polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. In addition, when the number of carbon atoms is less than 6, when the polycondensation with an aromatic dicarboxylic acid is performed, the melting point becomes high and fixing at low temperature may be difficult. On the other hand, when it exceeds 20, the separation of isomers is complicated. Therefore, it is difficult to obtain a compound having a practically preferable carbon number.

Further, when a crystalline polyester resin is obtained by condensation polymerization with the aromatic dicarboxylic acid, the number of carbon atoms is preferably an odd number. When the number of carbon atoms is an odd number, the crystalline polyester resin has a lower melting point than when it is an even number, and the melting point tends to be a value within the numerical range described later.
As said carbon number, it is desirable that it is 6-14, and it is more suitable that it is 8-12.

Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptane. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecane Examples include, but are not limited to, diol, 1,18-octadecanediol, and 1,20-eicosanediol. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
In addition, as diol in this embodiment, what is necessary is just to include the 2 types of diol from which C6-C20 differs, and carbon number may exceed it or may include it.

Of the two diols having different carbon numbers, 1,9-nonanediol, 1,10-decanediol, or the like is preferably used as the diol having the larger carbon number. As the diol having the smaller carbon number, it is desirable to use 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and the like.
Moreover, as a difference of carbon number of both said diols, it is desirable to set it as the range of 1-4.

In the two types of diols having different carbon numbers, the ratio of the constituent molar ratio A (mol%) of the diol having the smaller carbon number to the constituent molar ratio B (mol%) of the diol having the larger carbon number (A / B) is preferably in the range of 10/90 to 40/60. When the diol having the smaller carbon number is less than 10 constituent mol%, a good effect for suppressing recrystallization of the crystalline polyester resin cannot be obtained, and when it exceeds 40 constituent mol%, the melting point of the crystalline polyester resin is not obtained. As a result, the fixing property cannot be obtained.
The constituent molar ratio (A / B) is preferably in the range of 10/90 to 40/60, and more preferably in the range of 20/80 to 30/70.

In the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is preferably 80 constituent mol% or more, and other components are included as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is more preferably 90 constituent mol% or more.
If the content of the aliphatic diol-derived component is less than 80 mol%, the crystallinity of the crystalline polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability are deteriorated. May end up.

  Examples of the other components included as necessary include diol-derived constituent components having a double bond and diol-derived constituent components having a sulfonic acid group. Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol and the like.

  The content of these diol-derived constituent components having double bonds in all alcohol-derived constituent components is preferably 20 constituent mol% or less, and more preferably 2 to 10 constituent mol%. When the content exceeds 20 component mol%, the crystallinity of the crystalline polyester resin may be lowered, the melting point may be lowered, and the image storability may be deteriorated.

  Examples of the diol having a sulfonic acid group include 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, and 2-sulfo-1,4-butanediol sodium. Examples include salts.

The content of these diol-derived constituent components having a sulfonic acid group in the constituent components derived from all alcohols is preferably 5 constituent mol% or less, and only the minimum required amount is required.
When the content exceeds 5 component mol%, the hydrophilicity of the crystalline polyester resin increases, and the chargeability of the toner under high humidity may deteriorate. If it is not necessary, it is not necessary to use it as a copolymerization component, but a minimum amount may be used to assist emulsification of the resin. About the usage-amount, it is necessary to adjust the amount to the minimum especially with the dicarboxylic acid component which has the above-mentioned sulfonic acid group.

  When adding an alcohol-derived component other than these aliphatic diol-derived components (such as a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group), the content in these alcohol-derived components Is preferably in the range of 0 to 10 mol%.

  The crystalline polyester resin can be used in any combination of the monomer components described above, for example, polycondensation (chemical doujin), polymer experimental studies (polycondensation and polyaddition: Kyoritsu Publishing) and polyester resin handbook (Nikkan Kogyo). Can be synthesized by using a conventionally known method described in a newspaper company), or a transesterification method or a direct polycondensation method can be used alone or in combination.

  The molecular weight of the crystalline polyester resin is preferably in the range of 5000 to 20000 in weight average molecular weight and in the range of 2500 to 5000 in number average molecular weight. A weight average molecular weight in the range of 5,000 to 20,000 is preferable because a good low-temperature fixed image excellent in image strength and glossiness can be obtained.

The melting point of the crystalline polyester resin is preferably in the range of 70 to 90 ° C, more preferably in the range of 75 to 85 ° C.
When the melting point is in the above range, the low-temperature fixability is good, and at the same time, the occurrence of toner blocking can be suppressed even if the crystallinity is lowered.

  The mass ratio (C / D) between the content C of the crystalline polyester resin in the binder resin and the content D of the amorphous polyester resin is preferably in the range of 10/90 to 30/70. The range of is more desirable. If the amount of the crystalline polyester resin added is more than 30% by mass, the domain size of the crystalline polyester resin becomes large and is easily exposed on the toner surface, which may cause a decrease in toner powder fluidity and a deterioration in chargeability. is there. If it is less than 10% by mass, good low-temperature fixability may not be obtained.

In order to obtain the constituent ratio of the diol in the crystalline polyester resin from the components contained in the toner, the following method is used.
First, the crystalline polyester resin and the amorphous polyester resin in the toner are separated. First, the toner is left for 24 hours in a constant temperature bath at a temperature of 50 ° C. and a humidity of 55 RH%. Thereafter, 10 g of toner is added to 100 g of methyl ethyl ketone (MEK) at room temperature (20 to 25 ° C.) and mixed. This is because almost only the amorphous polyester resin is dissolved in MEK at room temperature, so that it can be separated from the crystalline polyester resin. Since the amorphous polyester resin is contained in the MEK solubles, from the supernatant separated by centrifugation (centrifuge “H-18”, Kokusan Co., Ltd., 3500 rpm for 20 minutes) after the dissolution. It may be considered that an amorphous polyester resin is obtained. The solid content after centrifugation is dissolved again in 100 g of MEK and centrifuged, and the supernatant is discarded. On the other hand, a crystalline polyester resin is obtained from a supernatant obtained by dissolving the solid content after centrifugation in 100 g of MEK under heating at 70 ° C. and separating the solid content by centrifugation.

Next, the separated supernatant is concentrated and dried with an evaporator, etc., and then the solid content is dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, and ¹ H-NMR measurement is performed. It is possible to calculate the constituent monomer types and ratios.

(Amorphous polyester resin)
In the present embodiment, the amorphous polyester resin contained in the binder resin is not particularly limited, but the glass transition point is preferably in the range of 40 to 75 ° C. In addition, in this embodiment, an amorphous polyester resin refers to having a step-like endothermic change in differential scanning calorimetry (DSC).
The monomer used for the amorphous polyester resin is a conventionally known divalent or trivalent or higher monomer component as described in, for example, Polymer Data Handbook: Basics (Science of Polymer Science: Bafukan). And carboxylic acids having a valence of 2 or more.

Specific examples of these monomer components include divalent carboxylic acids such as succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2. , 6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexanedicarboxylic acid, malonic acid, mesaconic acid, dodecenyl succinic acid, and other dibasic acids and their anhydrides and their lower alkyl esters; maleic acid, fumaric acid And aliphatic unsaturated dicarboxylic acids such as itaconic acid and citraconic acid.
Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

Examples of the divalent alcohol include bisphenol A, hydrogenated bisphenol A, ethylene oxide or (and) propylene oxide adduct of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, Examples include propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and neopentyl glycol.
Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used individually by 1 type and may use 2 or more types together. If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

  The amorphous polyester resin can also be obtained by the same method as that for the crystalline polyester resin, for example, by using a polycondensation, a transesterification method, a direct polycondensation method or the like alone or in combination. .

The amorphous polyester resin preferably has a weight average molecular weight in the range of 10,000 to 40,000, and more preferably in the range of 20,000 to 30,000.
The glass transition point (Tg) of the amorphous polyester resin is preferably in the range of 40 to 75 ° C, more preferably in the range of 50 to 65 ° C.

In this embodiment, the mass ratio (C / D) of the content C of the crystalline polyester resin and the content D of the amorphous polyester resin in the binder resin is in the range of 10/90 to 30/70. It is desirable that When the ratio of the two resins is within the above range, the effect of improving the toner image strength when the specific crystalline polyester resin is used can be effectively exhibited while maintaining the low-temperature fixability.
The mass ratio is more preferably in the range of 15/85 to 20/80.

(Coloring agent)
There is no restriction | limiting in particular as a coloring agent used for this embodiment, A well-known coloring agent is mentioned, It can select suitably according to the objective. One colorant may be used alone, or two or more colorants of the same system may be mixed and used. Further, two or more kinds of different colorants may be mixed and used. Further, these colorants may be used after surface treatment.

As the colorant, pigments and dyes of various colors are used, and specific examples include the following.
Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite. Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow NCG. it can.

  Examples of the orange pigment include red mouth yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK. Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watching red, permanent red 4R, risor red, brilliant carmine 3B, brilliant carmine 6B, pyrazolone red, rhodamine lake B, lake red C, rose bengal, eosin red. And alizarin lake.

  Examples of blue pigments include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, indanthrene blue BC, ultramarine blue, phthalocyanine blue, and phthalocyanine green. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.

  Examples of the green pigment include chromium oxide, chromium green, pigment green B, malachite green lake, and final yellow green G. Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.

Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, and quinoline yellow.
In addition, each color toner such as yellow toner, magenta toner, cyan toner, and black toner can be obtained by appropriately selecting the type of the colorant.

  The colorant used in the exemplary embodiment is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, light resistance, OHP permeability, and dispersibility in the toner. The colorant is preferably added in the range of 4% by mass to 15% by mass with respect to the total mass of the solid content of the toner in order to ensure color developability at the time of fixing. It is more preferable to add in the range. However, when using a magnetic substance as a black coloring agent, it is preferable to add within the range of 12 mass%-48 mass%, and it is more preferable to add within the range of 15 mass%-40 mass%.

(Other ingredients)
In this embodiment, a mold release agent can be used if necessary. The release agent is generally used for the purpose of improving the releasability.
Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. And mineral / petroleum waxes; ester waxes such as fatty acid esters, montanic acid esters and carboxylic acid esters; In this embodiment, these mold release agents may be used individually by 1 type, and may use 2 or more types together.

  The addition amount of these release agents is preferably in the range of 0.5 to 50% by mass, more preferably in the range of 1 to 30% by mass, and still more preferably in the range of 5 to 50% by mass with respect to the total amount of toner particles. It is in the range of 15% by mass. If the amount of the release agent added is in the above range, good powder flowability can be obtained after obtaining the effect of the release agent, and better chargeability can be obtained.

Other components that can be used in the present embodiment are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include various known additives such as inorganic particles, organic particles, charge control agents, release agents, and the like. Can be mentioned.
The inorganic particles are generally used for the purpose of improving toner fluidity. Examples of the inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride. , Bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, silicon nitride and the like. Among these, silica fine particles are preferable, and silica particles that have been hydrophobized are particularly preferable.

  The average primary particle diameter (number average particle diameter) of the inorganic particles is preferably in the range of 1 to 1000 nm, and the addition amount (external addition) is 0.01 to 20 parts by mass with respect to 100 parts by mass of the toner. The range of is preferable.

The organic particles are generally used for the purpose of improving cleaning properties, transfer properties, and sometimes charging properties. Examples of the organic particles include particles such as polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and polystyrene-acrylic copolymer.
The charge control agent is generally used for the purpose of improving chargeability. Examples of the charge control agent include salicylic acid metal salts, metal-containing azo compounds, nigrosine and quaternary ammonium salts.

(Toner structure and properties)
In the present embodiment, it is desirable that the surface of the toner is covered with a surface layer. It is desirable that the surface layer does not significantly affect the mechanical properties and melt viscoelastic properties of the entire toner. In this case, if the crystalline polyester resin is exposed on the toner surface, the external additive may be buried in the crystal part, and it may be difficult to maintain the quality. On the other hand, if the surface layer covers the toner thickly, the low-temperature fixability due to the use of the crystalline polyester resin may not be sufficiently exhibited. Therefore, it is desirable that the thickness of the surface layer is as thin as possible. When a resin coating layer is used, specifically, it is preferably in the range of 0.05 to 0.5 μm. In the case of a particle coating layer, the particles are desirably 0.5 μm or less.

In order to form a thin surface layer with the layer thickness in the above range, latex is adhered or adhered to the surface of toner particles including binder resin, colorant, inorganic particles added as necessary, and other materials. It is preferable to form a coating layer by adsorbing and smoothing the particles.
Further, a method of adsorbing a raw material monomer of the resin and coating the resin while performing graft polymerization, an interfacial polymerization, or a chemical treatment may be used, but a method capable of simplifying the toner manufacturing process as much as possible is preferable.

  The volume average particle size of the toner in the exemplary embodiment is desirably in the range of 4 to 9 μm, more desirably in the range of 4.5 to 8.5 μm, and further desirably in the range of 5 to 8 μm. When the volume average particle size is smaller than 4 μm, the toner fluidity is lowered, the chargeability of each particle is likely to be lowered, and the charge distribution is widened, so that fogging on the background and toner spillage from the developing device are likely to occur. . On the other hand, if it is smaller than 4 μm, the cleaning property may be extremely difficult. If the volume average particle size is larger than 9 μm, the resolution decreases, so that sufficient image quality cannot be obtained, and it may be difficult to satisfy recent high image quality requirements.

  The volume average particle size can be measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) with an aperture diameter of 50 μm. At this time, the measurement was performed after the toner was dispersed in an electrolyte aqueous solution (Isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.

In addition, the toner in the present embodiment is preferably a spherical shape having a shape factor SF1 in the range of 110 to 140. When the shape is spherical in this range, transfer efficiency and image density are improved, and high-quality image formation can be performed.
The shape factor SF1 is more preferably in the range of 115 to 138.

Here, the shape factor SF1 is obtained by the following equation (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and can be calculated as follows, for example. That is, an optical microscope image of toner particles dispersed on the surface of a slide glass is taken into a Luzex image analyzer through a video camera, the maximum length and projected area of 100 particles are obtained, calculated by the above equation (1), and the average value thereof Is obtained.

Further, it is desirable that the toner in this embodiment has an endothermic amount determined from an endothermic peak in a differential thermal analysis based on ASTM D3418-8 in a range of 20 to 40 mJ / mg. If the endothermic amount is less than 20 mJ / mg, the crystallinity is almost lost and the effects of low-temperature fixability and blocking resistance may not be obtained. If it exceeds 40 mJ / mg, the crystallinity increases, and the strength of the toner image after high-temperature storage described above may decrease.
The endothermic amount is more preferably in the range of 25 to 35 mJ / mg.

  The endothermic amount in the differential thermal analysis is determined by the following method. 1) Put 10 mg of sample in an aluminum cell and cover it (this is called a sample cell). For comparison, 10 mg of alumina is similarly put in an aluminum cell of the same type and covered (this is called a comparison cell). 2) Each of the sample cell and the comparison cell is set in a measuring device, heated from 30 ° C. to 200 ° C. at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere, and left at 200 ° C. for 10 minutes. 3) After standing, the temperature is lowered to −30 ° C. at a temperature decreasing rate of −10 ° C./min using liquid nitrogen and left at −30 ° C. for 10 minutes. 4) After standing, the temperature is raised from −30 ° C. to 200 ° C. at a temperature raising rate of 20 ° C./min. The endothermic / exothermic curve was measured during the operation of 4). As a measuring device, a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer was used.

Next, a method for manufacturing the toner will be described according to the embodiment.
As the method for producing the toner, an aggregation and coalescence method that facilitates shape control and resin coating layer formation is preferable. The aggregation coalescence method is a mixing step of mixing a resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and other release agent particle dispersions, and the resin particles, Aggregation step of forming aggregated particles such as the colorant particles and the release agent particles, and heating to a temperature not lower than the glass transition point of the resin particles (or not lower than the melting point of the crystalline polyester resin), the aggregated particles This is a production method having a fusion / unification process for fusing and uniting.

  Specifically, in general, a resin particle dispersion is prepared by an emulsion polymerization method, a phase inversion emulsification method, and the like, and an ionic surfactant, a colorant particle dispersion, a release agent particle dispersion, and the like are mixed to obtain an ionic property. Aggregated particles having a toner diameter are formed by causing heteroaggregation with an aggregating agent having a polarity opposite to that of the surfactant, and then, for example, the aggregated particles are fused by heating to a temperature equal to or higher than the glass transition point of the resin particles. Combine, wash and dry to obtain toner particles.

For example, when a vinyl monomer is used as the amorphous resin particles, the resin particle dispersion can be prepared by performing emulsion polymerization using an ionic surfactant or the like.
For example, in the case of a polyester resin, if the resin is soluble in an oily solvent with a relatively low solubility in water, the resin is dissolved in those solvents, and a homogenizer together with an ionic surfactant or polymer electrolyte in water. A resin particle dispersion can be prepared by dispersing the particles in water using a disperser and then evaporating the solvent by heating or decompressing.

Alternatively, water is gradually dropped into a resin melted in a solvent at high temperature, and the resin is dispersed as particles in water by phase inversion from a W / O emulsion to an O / W emulsion (phase inversion emulsification method), and then heated. Alternatively, the resin particle dispersion can be produced by evaporating the solvent under reduced pressure.
The crystalline polyester resin can be blended in the toner by, for example, dissolving and mixing in the resin particle dispersion, or mixing at the time of preparing the release agent particle dispersion.

Examples of the disperser used for dispersing the resin particle dispersion include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser.
The size of the resin particles is preferably in the range of 0.01 to 1.0 μm, more preferably 0.03 to 0.6 μm, and more preferably 0.03 to 0.4 μm in terms of the average particle size (volume average particle size). More desirable. In addition, the volume average particle diameter of the resin particles is measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). The following is also equivalent.

  The colorant is dispersed by a known method, for example, a rotary shear type homogenizer, a ball mill, a sand mill, an attritor, a media disperser such as a coball mill, a roll mill such as a three roll mill, a cavitation mill such as a nanomizer, a colloid mill, A high-pressure opposed collision type disperser or the like is preferably used.

  The center diameter (median diameter) of the colorant particles is preferably in the range of 100 to 330 nm, and more preferably in the range of 100 to 280 nm. By setting the center diameter within such a range, it is possible to ensure transparency and color developability when an image is formed on the OHP.

With respect to the mold release agent, for example, these are dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid or a polymer base, heated to a melting point or higher, and a homogenizer having a strong shearing ability, A release agent dispersion can be obtained by dispersing in a particle form having a diameter of 1 μm or less with a pressure discharge type disperser (Gorin homogenizer, manufactured by Gorin).
The concentration of the surfactant used in the release agent dispersion is preferably 4% by mass or less with respect to the release agent. If it exceeds 4% by mass, the agglomeration rate of particle formation becomes slow, the heating time becomes long, and the aggregates increase, which is not preferable.

  The release agent is, for example, dispersed in the electrophotographic toner as particles having a volume average particle diameter in the range of 150 to 300 nm, and contained in the above-mentioned preferable content, thereby fixing the fixed image in the oilless fixing method. Peelability can be improved. A more preferable range of the particle diameter is a volume average particle diameter of 180 to 280 nm.

  Examples of the surfactant used for the purpose of emulsion polymerization of the resin particles, dispersion of the colorant, dispersion of the release agent, aggregation thereof, stabilization thereof, and the like include sulfate ester, sulfonate, phosphate And anionic surfactants such as soaps and soaps, and cationic surfactants such as amine salt type and quaternary ammonium salt type. It is also effective to use a nonionic surfactant such as polyethylene glycol, alkylphenol ethylene oxide adduct, and polyhydric alcohol. As these dispersing means, general means such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, a dyno mill and the like can be used.

  When using colorant particles coated with polar resin particles, the resin and colorant are dissolved and dispersed in a solvent (water, surfactant, alcohol, etc.), and then the appropriate dispersant (activator as described above) is used. In addition, the colorant particles are fixed to the surface of resin fine particles prepared by emulsion polymerization using mechanical shearing force or electrical adsorption force. It is possible to adopt a method of making it. These methods are effective in suppressing the liberation of the colorant added to the aggregated particles and improving the dependency of the chargeable colorant.

  In the agglomeration step, first, for example, the obtained dispersion liquid of the crystalline polyester resin particles, the dispersion liquid of the amorphous polyester resin particles, the colorant dispersion liquid, and the like are mixed to obtain a mixed liquid. Aggregates by heating at a temperature below the glass transition temperature to form aggregated particles. Aggregated particles are formed by acidifying the pH of the mixed solution with stirring. As pH, the range of 2-7 is desirable, The range of 2.2-6 is more desirable, The range of 2.4-5 is still more desirable. At this time, it is also effective to use a flocculant.

  As the flocculant to be used, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is particularly desirable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, it is more suitable that the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, and tetravalent than trivalent.

  When producing toner particles, it is desirable to first add only the resin particle dispersion into the agglomeration system, and after aggregating only the resin particles, it is preferable to add the colorant or release agent dispersion. . Thereby, inhibition of aggregation of the resin particles due to the presence of the release agent particles or the like can be avoided, and the above-described desirable toner particle structure can be obtained efficiently.

  Further, when the aggregated particles have a desired particle size, a toner having a structure in which the surface of the core aggregated particles is coated with the amorphous polyester resin can be prepared by adding amorphous polyester resin particles. Good. In this case, the crystalline polyester resin is difficult to be exposed on the toner surface, which is desirable from the viewpoint of chargeability and developability. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

  In the fusion and coalescence process, the agglomeration is stopped by increasing the pH of the suspension of aggregated particles to a range of 3 to 9 under stirring conditions in accordance with the aggregation process. The aggregated particles are fused by heating at a temperature equal to or higher than the melting point. Further, when coated with the amorphous polyester resin, the amorphous polyester resin is also fused to coat the core aggregated particles. The heating time may be as long as fusion is performed, and may be performed for about 0.5 to 10 hours.

  After completion of the fusion and coalescence, desired toner particles can be obtained through an arbitrary washing process, solid-liquid separation process, and drying process. It is preferable to perform replacement washing with exchange water. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, centrifugal filtration, decanter and the like are preferably used from the viewpoint of productivity. Further, the drying process is not particularly limited, but from the viewpoint of productivity, aeration drying apparatus, spray drying apparatus, rotary drying apparatus, air flow drying apparatus, fluidized bed drying apparatus, heat transfer heating type drying apparatus, freeze drying apparatus, etc. are preferably used. It is done.

  Furthermore, for the purpose of imparting fluidity and improving cleaning properties, as in normal toner production, metal salts such as calcium carbonate, silica, alumina, titania, barium titanate, strontium titanate, calcium titanate, cerium oxide, Adding inorganic particles such as metal oxide compounds such as zirconium oxide and magnesium oxide, ceramics, carbon black, etc., and resin particles such as vinyl resin, polyester, and silicone to the toner surface in a dry state by applying a shearing force. Can do.

  These inorganic particles are preferably surface-treated with a coupling agent or the like in order to control conductivity, chargeability, and the like. Specific examples of the coupling agent include methyltrichlorosilane, methyldichlorosilane, and dimethyldichlorosilane. , Trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltri Ethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethylsilazane, N, N- (bistrimethylsilyl) acetamide, N, -Bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane, Silane coupling agents and titanium coupling agents such as γ-glycidoxy propyl trimethoxy silane, γ-glycidoxy propyl methyl diethoxy silane, γ-mercaptopropyl trimethoxy silane, γ-chloropropyl trimethoxy silane, etc. Etc.

  As a method for adding particles, after the toner is dried, it may be adhered to the toner surface by a dry method using a mixer such as a V blender or a Henschel mixer, or the particles may be made into water or an aqueous liquid such as water / alcohol. After being dispersed, it may be added to the toner in a slurry state and dried to allow an external additive to adhere to the toner surface. Moreover, you may dry, spraying a slurry on dry powder.

<Electrostatic image developer>
Next, the developer of the present invention will be described.
The developer of the present invention is not particularly limited except that it contains the toner of the present invention, and an appropriate component composition can be taken according to the purpose. The developer of the present invention becomes a one-component developer when the toner is used alone, and becomes a two-component developer when the toner and carrier are used in combination.

The carrier is not particularly limited, and examples thereof include known carriers. For example, known carriers such as resin-coated carriers described in JP-A-62-39879, JP-A-56-11461, etc. Is mentioned.
Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include normal iron powder, ferrite, magnetite molding, and the like, and the volume average particle size is in the range of about 30 to 200 μm.

  Examples of the coating resin of the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. Α-methylene fatty acid monocarboxylic acids such as methyl methacrylate, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone Homopolymers such as vinyl ketones such as; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene, and hexafluoroethylene; or copolymers comprising two or more types of monomers, Furthermore, silicone resins including methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by mass, more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core particles.

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .

  In the developer of the present invention, the mixing ratio of the toner and the carrier is not particularly limited and can be appropriately selected according to the purpose.

<Image forming apparatus>
Next, the image forming apparatus of the present invention using the electrostatic image developing toner of the present invention will be described.
The image forming apparatus of the present invention includes an image carrier, a developing unit that develops an electrostatic image formed on the image carrier as a toner image with a developer, and a toner image formed on the image carrier. The image forming apparatus includes a transfer unit that transfers onto a transfer body and a fixing unit that fixes a toner image transferred onto the transfer body, and uses the electrostatic image developer of the present invention as the developer.

In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus main body. As the process cartridge, a developer holding body is used. The process cartridge of the present invention that contains at least the electrostatic image developer of the present invention is preferably used.
Hereinafter, an example of the image forming apparatus of the present invention will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  FIG. 1 is a schematic diagram showing a quadruple tandem full-color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed at a predetermined distance in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other from the left to the right in the drawing. It is designed to travel in the direction toward 10K. The support roller 24 is urged away from the drive roller 22 by a spring or the like (not shown), and a predetermined tension is applied to the intermediate transfer belt 20 wound around the support roller 24. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K includes yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four color toners can be supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. Note that the second to fourth units are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of 10M, 10C, 10K is omitted.

The first unit 10Y has a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, an electrostatic charge image is formed by exposing the surface of the photoreceptor 1Y to a predetermined potential with a charging roller 2Y and the charged surface with a laser beam 3Y based on the color-separated image signal. An exposure device 3; a developing device (developing means) 4Y for supplying the charged toner to the electrostatic image and developing the electrostatic image; a primary transfer roller 5Y (primary) for transferring the developed toner image onto the intermediate transfer belt 20; A transfer unit), and a photoconductor cleaning device (cleaning unit) 6Y for removing toner remaining on the surface of the photoconductor 1Y after the primary transfer.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged to a potential of about −600V to −800V by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (a resistance equivalent to that of a general resin), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) by the developing device 4Y.

  In the developing device 4Y, for example, yellow toner having a volume average particle diameter of 7 μm containing at least a yellow colorant, a crystalline polyester resin, and an amorphous polyester resin is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a predetermined primary transfer bias is applied to the primary transfer roller 5Y, and the electrostatic force directed from the photoreceptor 1Y to the primary transfer roller 5Y generates a toner image. The toner image on the photoreceptor 1 </ b> Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner.

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in multiple layers through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20 and the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing into a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via a supply mechanism, and a predetermined secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording paper P is sent to a fixing device (fixing means) 28, where the toner image is heated, and the color-superposed toner image is melted and fixed on the recording paper P. The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but the present invention is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing a preferred example of a process cartridge containing the electrostatic charge image developer of the present invention. In the process cartridge 200, a charging roller 108, a developing device 111, a photoconductor cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure are attached to a rail 116 together with the photoconductor 107. Are combined and integrated with each other.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, and other components (not shown). It forms a forming apparatus. Reference numeral 300 denotes a recording sheet.

  The process cartridge shown in FIG. 2 includes a charging device 108, a developing device 111, a cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. Can be selectively combined. In the process cartridge of the present invention, in addition to the photosensitive member 107, from the charging device 108, the developing device 111, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. It comprises at least one selected from the group consisting of.

  Next, the toner cartridge of the present invention will be described. The toner cartridge of the present invention is detachably attached to the image forming apparatus, and at least the toner cartridge for storing toner to be supplied to the developing means provided in the image forming apparatus, the toner described above. Toner. The toner cartridge of the present invention only needs to contain at least toner, and may contain developer, for example, depending on the mechanism of the image forming apparatus.

  Therefore, in an image forming apparatus having a configuration in which a toner cartridge can be attached and detached, the storage stability can be maintained even in a toner cartridge whose container is miniaturized by using the toner cartridge containing the toner of the present invention. This makes it possible to achieve low-temperature fixing while maintaining high image quality.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are respectively the developing devices ( And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge is low, the toner cartridge can be replaced.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples. In the following, “part” means “part by mass” and “%” means “% by mass” unless otherwise specified.

<Measuring method of various characteristics>
First, a method for measuring physical properties of toners and the like used in Examples and Comparative Examples (excluding the method described above) will be described.
(Measurement method of molecular weight and molecular weight distribution of resin)
The molecular weight and molecular weight distribution of the crystalline polyester resin and the like are those obtained under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. As experimental conditions, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.
The data collection interval in sample analysis was 300 ms.

(Measuring method of toner, resin melting point, glass transition temperature)
The melting point of the crystalline polyester resin and the glass transition point (Tg) of the amorphous polyester resin are 25 using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC60, with an automatic tangential treatment system) in accordance with ASTM D3418-8. It was determined by measuring from 10 ° C. to 150 ° C. under a temperature increase rate of 10 ° C./min. The melting point was the peak temperature of the endothermic peak, and the glass transition point was the temperature of the endothermic rising point on the low temperature side in the stepwise endothermic amount change.

<Preparation of each dispersion>
(Amorphous polyester resin dispersion)
A flask in which 97 parts of dimethyl terephthalate, 78 parts of dimethyl isophthalate, 27 parts of dodecenyl succinic anhydride, 111 parts of bisphenol A-ethylene oxide adduct, 249 parts of bisphenol A-propylene oxide adduct and 0.08 part of dibutyltin oxide were replaced with nitrogen. The mixture was reacted at 170 for 2 hours and further under reduced pressure at 220 ° C. for 5 hours to obtain an amorphous polyester resin having a weight average molecular weight of 48000, a number average molecular weight of 24900, and a glass transition point of 62 ° C.

  300 parts of amorphous polyester resin was weighed into a flask together with 96 parts of ethyl acetate and 96 parts of 2-propanol, heated to 60 ° C. with a water bath (IWB.100, manufactured by ASONE), and a stirrer (BL600, manufactured by HEIDON). Was melted with stirring at a rotational speed of 20 rpm. After completion of melting, 16.5 parts of a 10% aqueous ammonia solution was gradually added while dropping with a dropper, and then 1500 parts of ion-exchanged water was added at a dropping speed using a quantitative liquid feed pump (MP-3N, manufactured by EYELA). The mixture was gradually dropped while maintaining 7 to 8 g / min, and the stirring speed was changed to 100 rpm and stirring was performed at the same time.

  Three hours later, when 700 parts of ion-exchanged water had been dropped, nitrogen flow was performed to remove ethyl acetate from the resin dispersion. After 1 hour, when the removal of ethyl acetate was completed, the flask was removed from the water bath and cooled at room temperature. When the resin dispersion is cooled to room temperature, it is transferred to an eggplant flask and heated to 40 ° C. in a water bath (B-480, manufactured by SHIBATA), while an evaporator (Rotavapor R-114, manufactured by SHIBATA), a vacuum controller (NVC) -1100, manufactured by EYELA), 2-propanol was removed to obtain an amorphous polyester resin dispersion having an average particle size of 110 nm and a solid content concentration of 30%.

(Crystalline polyester resin dispersion (1))
241 parts of dodecanedioic acid, 125.8 parts of 1,9-nonanediol, 30.9 parts of 1,6-hexanediol, and 0.08 part of dibutyltin oxide are placed in a flask purged with nitrogen, and further at 180 ° C. for 4 hours. Reaction was performed at 190 ° C. under reduced pressure for 5 hours to obtain a crystalline polyester resin (1). The crystalline polyester resin (1) had a weight average molecular weight of 18000, a number average molecular weight of 9,500, and a melting point of 74 ° C.

  200 parts of crystalline polyester resin (1) was weighed into a flask together with 64 parts of ethyl acetate and 64 parts of 2-propanol, heated to 60 ° C. with a water bath (IWB.100, manufactured by ASONE), and a stirrer (BL600, HEIDON Melted with stirring at a rotation speed of 20 rpm. After completion of melting, 11 parts of 10% aqueous ammonia solution was gradually added while dropping with a dropper, and then 1800 parts of ion-exchanged water was added at a dropping rate of 7 to 7 using a quantitative liquid feed pump (MP-3N, manufactured by EYELA). The mixture was gradually dropped while maintaining 8 g / min, and at the same time, the stirring speed was changed to 100 rpm and stirring was performed.

  After 2 hours, when dropping of 700 parts of ion-exchanged water was completed, nitrogen flow was performed to remove ethyl acetate in the resin dispersion. After 1 hour, when the removal of ethyl acetate was completed, the flask was removed from the water bath and cooled at room temperature. When the resin dispersion is cooled to room temperature, it is transferred to an eggplant flask and heated to 40 ° C. with a water bath (B-480, manufactured by SHIBATA), while an evaporator (Rotavapor R-114, manufactured by SHIBATA), a vacuum controller (NVC- 1100, manufactured by EYELA), 2-propanol was removed to obtain a crystalline polyester resin dispersion (1) having an average particle diameter of 110 nm and a solid content concentration of 15%.

(Crystalline polyester resin dispersion (2))
According to the synthesis of the crystalline polyester resin dispersion (1) except that the amount of the alcohol component was changed to 147.6 parts of 1,9-nonanediol and 14.8 parts of 1,6-hexanediol, the crystalline property A polyester resin (2) was obtained. This crystalline polyester resin (2) had a weight average molecular weight of 24,000, a number average molecular weight of 13,000, and a melting point of 78 ° C.
Moreover, the crystalline polyester resin dispersion (2) was obtained using the crystalline polyester resin (2) according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (3))
According to the synthesis of the crystalline polyester resin dispersion (1) except that the amount of the alcohol component was changed to 104 parts of 1,9-nonanediol and 47 parts of 1,6-hexanediol, the crystalline polyester resin (3 ) The crystalline polyester resin (3) had a weight average molecular weight of 16000, a number average molecular weight of 8500, and a melting point of 72 ° C.
Moreover, using the crystalline polyester resin (3), a crystalline polyester resin dispersion (3) was obtained according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (4))
300 parts of sebacic acid, 160 parts of 1,9-nonanediol, 60 parts of 1,6-hexanediol and 0.08 g of dibutyltin oxide were placed in a flask purged with nitrogen, 4 hours at 180 ° C, and 5 minutes at 190 ° C under reduced pressure. The reaction was performed for a time to obtain a crystalline polyester resin (4). The weight average molecular weight of the crystalline polyester resin (4) was 24000, the number average molecular weight was 12000, the melting point was 68 ° C., and (A / B) was 33/67.
Moreover, using this crystalline polyester resin (4), a crystalline polyester resin dispersion (4) was obtained according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (5))
400 parts of 1-10 decanedicarboxylic acid, 190 parts of 1-18 octadecanediol, 67 parts of 1-14 tetradecanediol, and 0.08 part of dibutyltin oxide were placed in a flask purged with nitrogen, and further reduced pressure at 180 ° C. for 4 hours. Reaction was performed at 190 ° C. for 5 hours to obtain a crystalline polyester resin (5). The weight average molecular weight of the crystalline polyester resin (5) was 34,000, the number average molecular weight was 18000, and the melting point was 92 ° C.
Moreover, using this crystalline polyester resin (5), a crystalline polyester resin dispersion (5) was obtained according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (6))
According to the synthesis of the crystalline polyester resin dispersion (1) except that the amount of the alcohol component was changed to 100 parts of 1,9-nonanediol and 60 parts of 1,6-hexanediol, the crystalline polyester resin (6 ) This crystalline polyester resin (6) had a weight average molecular weight of 24,000, a number average molecular weight of 13,000, and a melting point of 76 ° C.
Moreover, the crystalline polyester resin dispersion (6) was obtained using the crystalline polyester resin (6) according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (7))
According to the synthesis of the crystalline polyester resin dispersion (1) except that the amount of the alcohol component is changed to 155.9 parts of 1,9-nonanediol and 8.7 parts of 1,6-hexanediol. A polyester resin (7) was obtained. The crystalline polyester resin (7) had a weight average molecular weight of 26000, a number average molecular weight of 13500, and a melting point of 82 ° C.
Moreover, using the crystalline polyester resin (7), a crystalline polyester resin dispersion (7) was obtained according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (8))
A crystalline polyester resin (8) was obtained according to the synthesis of the crystalline polyester resin dispersion (1) except that the amount of the alcohol component was changed to only 160 parts of 1,10-decanediol. This crystalline polyester resin (8) had a weight average molecular weight of 21,000, a number average molecular weight of 10,000, and a melting point of 79 ° C.
Moreover, the crystalline polyester resin dispersion (8) was obtained using the crystalline polyester resin (8) according to the preparation of the crystalline polyester resin dispersion (1).

(Crystalline polyester resin dispersion (9))
241 parts of sebacic acid, 160 parts of 1,6-hexanediol and 0.08 g of dibutyltin oxide were placed in a flask purged with nitrogen and reacted at 180 ° C. for 4 hours and further under reduced pressure at 190 ° C. for 5 hours to obtain a crystalline polyester resin ( 9) was obtained. The crystalline polyester resin (9) had a weight average molecular weight of 22,000, a number average molecular weight of 12000, and a melting point of 67 ° C.
Moreover, using this crystalline polyester resin (9), a crystalline polyester resin dispersion (9) was obtained according to the preparation of the crystalline polyester resin dispersion (1).

(Colorant dispersion)
Those having the following composition were mixed and dissolved, and dispersed by a homogenizer (manufactured by IKA, Ultra Turrax T50) and ultrasonic irradiation to obtain a blue pigment dispersion having a volume average particle diameter of 150 nm.
Cyan pigment C.I. I. Pigment Blue 15: 3 (copper phthalocyanine, manufactured by Dainippon Ink & Co., Ltd.) 50 parts, anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts, ion-exchanged water 200 parts

(Release agent dispersion)
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a gorin homogenizer (manufactured by Reiwa Corporation) and treated 20 times at 105 ° C. and 550 kg / cm ² to obtain a release agent dispersion having a volume average particle size of 190 nm.
・ Wax (WEP-5, manufactured by NOF Corporation) 25 parts ・ Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts ・ Ion-exchanged water 200 parts

<Example 1>
(Production of toner)
Amorphous polyester resin dispersion: 200 parts Crystalline polyester resin dispersion (1): 80 parts Ion exchange water: 400 parts Colorant dispersion: 25 parts Release agent dispersion: 60 parts Each of the above The components were mixed in a round stainless steel flask and stirred at room temperature (25 ° C.) for 30 minutes. After completion of stirring, 75 parts of 10% aluminum sulfate aqueous solution (manufactured by Asada Chemical Co., Ltd.) was added dropwise with a dropper, and mixed and dispersed with a homogenizer (manufactured by IKA, Ultra Tarrax T50). The mixture was stirred and heated to 45 ° C. and kept at 45 ° C. for 30 minutes.

  When the obtained contents were observed with an optical microscope, it was confirmed that aggregated particles having a particle size of about 5.6 μm were formed. Here, 120 parts of the amorphous polyester resin dispersion was adjusted to pH 3 and then added to the aggregated particle dispersion. Thereafter, the temperature of the obtained contents was gradually increased to 55 ° C. When the obtained contents were observed with an optical microscope, it was confirmed that aggregated particles having a particle size of about 6.4 μm were formed. Next, the pH was adjusted to 8 with an aqueous sodium hydroxide solution, and then the temperature was raised to 90 ° C., and then aggregated particles were combined for about 1 hour. After cooling, it was filtered, washed thoroughly with ion exchange water, and dried to obtain toner particles (1).

When the particle diameter of the toner particles (1) was measured with a Coulter counter, the volume average particle diameter was 6.4 μm. The volume GSD, which is an index of the volume particle size distribution, was 1.24.
Here, the volume GSD is a volume average particle size distribution curve measured using the Coulter Multisizer, and obtains a volume average particle size D84 having a frequency of 84% and a volume average particle size D16 having a frequency of 16% from the small particle size side. Each value can be obtained by substituting (D84 / D16) ^1/2 . The volume average particle diameter indicates a volume average particle diameter D50 of 50%.
Further, the endothermic amount in DSC of the toner particles (1) obtained by the above-described method was 30 mJ / mg.

(Evaluation of toner)
The toner particles (1) were obtained by calcining 0.5% of silica treated with hexamethyldisilazane having an average particle size of 40 nm as an external additive, and titanium titanate obtained by treating metatitanic acid with 50% isobutyltrimethoxysilane. (Average particle size: 30 nm) is added to 0.7%, mixed for 10 minutes with a 75 L Henschel mixer, and then sieved with a wind sieving machine Hi-Voltter 300 (manufactured by Shin Tokyo Kikai Co., Ltd.). ) Was produced.

On the other hand, for 100 parts of ferrite core having a volume average particle size of 50 μm, 0.15 part equivalent of vinylidene fluoride resin and 1.35 part equivalent of methyl methacrylate / trifluoroethylene copolymer (copolymerization ratio) : 80/20) was coated using a kneader apparatus to prepare a carrier.
The obtained carrier and the toner (1) were mixed at a ratio of 100 parts: 8 parts by a 2 liter V blender to prepare a developer.

-Fixability-
The fixing device was removed from the DocuCentreColor 400 of Fuji Xerox Co. filled with the developer (1), and an unfixed image was collected. The image conditions were a solid image (solid image) of 40 mm × 50 mm, the applied toner amount was 1.5 g / m ² , and J paper (manufactured by Fuji Xerox Official Supply) was used as the recording paper.

Next, using a DocuCentreColor400 remodeling machine remodeled so that the fixing temperature is variable, the fixing property of each image was evaluated while increasing the fixing temperature stepwise from 100 ° C. to 200 ° C. every 5 ° C. Note that the fixability is an image in which a good fixed image without image loss due to defective release is bent for 5 seconds using a weight of 1 kg load, and the width of the image defect in that portion is shown in mm. The temperature at which the width became 0.5 mm or less was defined as the minimum fixing temperature.
The results are shown in Table 1.

-Image retention-
The prepared developer is applied to a DocuCentreColor400 remodeling machine (fixing temperature is changed to 150 ° C.) manufactured by Fuji Xerox Co., Ltd., and a solid image (toner load: 4.5 g / h) is obtained in a normal temperature and humidity environment (25 ° C., 50% RH). m ² ) image formation was performed. A crease was made on the inside of the solid portion of the obtained fixed toner image, and the portion where the fixed toner image was destroyed was wiped with tissue paper, and the white line width was measured.

On the other hand, a solid image formed in the same manner is stored in a high temperature environment (50 ° C., 50% RH) for 1 week, the image is bent, a weight of 1 kg is applied for 10 seconds, the bent portion is returned, and a fixed toner image is formed. The destroyed part was wiped off with tissue paper, and the white line width was measured. With respect to the above-described blank line width, the image retention after being left in the initial stage was evaluated according to the following criteria.
A: The white line width is less than 0.2 mm.
○: The white line width is 0.2 mm or more and less than 0.5 mm.
Δ: The blank line width is 0.5 mm or more and less than 1.0 mm.
X: The white line width is 1.0 mm or more.
The results are shown in Table 1.

-Blocking resistance-
10 g of the toner was weighed on a propylene cup, left in an environment of 50 ° C. and 50% RH for 17 hours, and the blocking (aggregation) state was evaluated according to the following criteria.
A: When the cup is tilted, the toner flows more smoothly.
○: When the cup is moved, the toner gradually collapses and flows out.
Δ: A block body is generated and collapses when it is pointed with a pointed object.
X: A block body is generated, and it is hard to collapse even if it bumps with a pointed object.
The results are shown in Table 1.

<Examples 2 to 5>
A toner was prepared in the same manner as in Example 1 except that the crystalline polyester resins (2) to (5) were used as shown in Table 1 instead of the crystalline polyester resin (1). The same evaluation was performed. The toner of each example had the same particle size and particle size distribution as in Example 1.
The results are summarized in Table 1.

<Example 6>
The toner was prepared in the same manner as in Example 1 except that the amorphous polyester resin dispersion was 270 parts and the crystalline polyester resin dispersion (1) was 15 parts. went.
The results are shown in Table 1.

<Example 7>
The toner was prepared in the same manner as in Example 1 except that the amorphous polyester resin dispersion was 170 parts and the crystalline polyester resin dispersion (1) was 115 parts. went.
The results are shown in Table 1.

<Comparative Examples 1-4>
In the preparation of the toner of Example 1, a toner was prepared in the same manner except that the crystalline polyester resins (6) to (9) were used as shown in Table 1 instead of the crystalline polyester resin (1). The same evaluation was performed.
The results are summarized in Table 1.

  As shown in Table 1, in the case of the toner used in the examples, it was confirmed that in addition to the low-temperature fixability, both image quality retention and blocking resistance during storage at high temperatures were excellent. In the case of Example 5, since the melting point of the crystalline polyester resin was lower than that of Example 1 and the like, the image quality deterioration could be suppressed although the blocking resistance was slightly inferior.

  On the other hand, since the toners of Comparative Examples 1 to 3 have a higher degree of crystallization than the toners of the examples, the crystallization inside the image proceeds at a high temperature, the image is easily broken, and good image quality cannot be maintained. . Further, the toner of Comparative Example 4 was inferior to the toner of Comparative Example 3 in that the crystalline polyester resin had a lower melting point itself, so that the progress of crystallization was small but the blocking resistance was poor. In any of the comparative examples, it was difficult to achieve both image retention at high temperature and blocking resistance.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows an example of the process cartridge of this invention.

Explanation of symbols

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening 118 for static elimination exposure Opening 200 for exposure Process cartridge,
P, 300 Recording paper (transfer object)

Claims (8)

A binder resin including a crystalline polyester resin and an amorphous polyester resin, and a colorant;
The crystalline polyester resin is a polyester resin obtained by polymerizing an acid component and an alcohol component containing two kinds of diols having 6 to 20 carbon atoms and different carbon numbers,
The ratio of the constituent molar ratio A (mol%) of the diol having the smaller carbon number to the constituent molar ratio B (mol%) of the diol having the larger carbon number of the two diols having different carbon numbers. (A / B) is in the range of 10/90 to 40/60.   The mass ratio (C / D) of the content C of the crystalline polyester resin and the content D of the amorphous polyester resin in the binder resin is in the range of 10/90 to 30/70, The toner for developing an electrostatic image according to claim 1.   The toner for developing an electrostatic charge image according to claim 1, wherein the crystalline polyester resin has a melting point in a range of 70 to 90 ° C. 3.   The electrostatic charge image development according to any one of claims 1 to 3, wherein an endothermic amount obtained from an endothermic peak in a differential thermal analysis based on ASTM D3418-8 is in a range of 20 to 40 mJ / mg. Toner.   An electrostatic image developer, comprising a toner, wherein the toner is the electrostatic image developing toner according to claim 1.   A toner cartridge comprising at least a toner, wherein the toner is the electrostatic image developing toner according to claim 1.   A process cartridge comprising at least a developer holder and containing the electrostatic charge image developer according to claim 5.   An image carrier, a developing unit that develops an electrostatic image formed on the image carrier as a toner image with a developer, and a transfer unit that transfers the toner image formed on the image carrier onto a transfer target An image forming apparatus comprising: a fixing unit configured to fix a toner image transferred onto a transfer target; and the developer is the electrostatic charge image developer according to claim 5.

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