JP4500239B2 - Toner, image forming apparatus using the same, and process cartridge - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic latent image used for image formation by an electrostatic copying process such as a copying machine, a facsimile machine, and a printer, and also relates to an image forming apparatus using the toner.

The energy saving of image forming apparatuses has been promoted, and low temperature fixing of toner is required for heat and pressure fixing of a toner image formed with an image. In recent years, it has also been important to save energy in the fixing device, and a method for improving the temperature responsiveness of the toner by reducing the heat capacity of the fixing member has been adopted. In order to achieve low-temperature fixing with such a fixing device, the toner needs to be fixed at a temperature lower than that of conventional toners. On the other hand, not only an amorphous resin but also a crystalline resin is used as a binder resin. Many reports have been made. Since the crystalline resin melts rapidly near its glass transition temperature, the anchoring effect (for example, the paper surface of the recording sheet and entanglement with the fibers) causes the binder resin to be at a lower temperature than the toner containing only the amorphous resin. It becomes easy to fix. The characteristic of this crystalline resin is remarkable in the case of crystalline polyester, and crystalline polyester is often used.
However, using only crystalline polyester may not be sufficient to achieve low-temperature fixability higher than conventional, and even if low-temperature fixability can be achieved, hot offset resistance and blocking resistance cannot be satisfied. There is a case. In order to achieve low-temperature fixability higher than before, it is necessary that the crystalline polyester is compatible with the amorphous resin to lower the glass transition temperature (Tg) of the toner and lower the melting viscosity lowering start temperature. .

  However, in order to ensure hot offset resistance and blocking resistance, the crystalline polyester and the amorphous resin are incompatible and dispersed, and the dispersed crystalline polyester maintains crystallinity. is necessary. In order to satisfy the compatibility / non-compatibility state of the non-crystalline polyester-crystalline polyester in such a trade-off relationship, the low-temperature fixability, the hot offset resistance and the blocking resistance are For compatibility, various methods have been reported in the combination of crystalline polyester and amorphous polyester.

A method in which raw material monomers having a similar structure are contained in the respective raw material monomers of the crystalline polyester and the amorphous resin so that they are compatible with each other (for example, see Patent Document 1). A method of obtaining sufficient low-temperature fixability while the crystalline polyester and the amorphous resin are incompatible with each other (for example, see Patent Document 2). There is a method in which a crystalline polyester and an amorphous resin are easily compatible with each other, but both have a phase separation structure (see, for example, Patent Document 3).
However, even if these methods are used, in the case of a full color toner in which the gel component and the high molecular weight component are likely to be reduced, the compatible range tends to be narrowed. In particular, it is difficult to ensure blocking resistance. On the other hand, a crystal nucleating agent is blended in the toner to promote recrystallization of the crystalline resin in the toner (see, for example, Patent Documents 4 and 5).

Compared to amorphous resin, crystalline polyester is accompanied by the release of internal latent heat to shift from the amorphous state to the crystalline state when it is cooled. The toner is difficult to cool after being melted. This is also true for an image after fixing, and an image formed with a toner containing crystalline polyester is more difficult to cool after fixing than before. For this reason, an image formed with a toner containing crystalline polyester is more difficult to cool after fixing than a conventional toner, and is in a state of being easily blocked. Furthermore, when the crystalline polyester is recrystallized, the toner that secures blocking resistance is in a state where the image is likely to be blocked if the toner is cooled and recrystallization does not proceed.
In recent years, there are many opportunities for duplex printing to save paper resources. In particular, in the case of a full-color image that tends to have a high image area ratio, when a large number of sheets are output by double-sided printing, the touched images are likely to stick to each other due to blocking. When blocking occurs, the image surface may become rough when images are peeled off. Further, if the blocking state is severe, an image defect may occur when peeling off.
Therefore, the method of promoting crystallization with a nucleating agent is effective not only for ensuring the blocking resistance of the toner but also for ensuring the blocking resistance of the image after fixing.
As such a nucleating agent, fine inorganic crystal nucleating agents such as silica and talc and organic crystal nucleating agents such as benzoic acid metal salts and fatty acid metal salts are used. However, inorganic crystal nucleating agents such as silica and talc exhibit a filler effect when the amount is large, and inhibit the low-temperature fixability to increase the melt viscosity of the toner. In particular, when silica is used, it is difficult to control the charge level because of high chargeability. Furthermore, since the hardness is high, the surface of the photoreceptor and the surface of the fixing member are damaged. Therefore, an organic crystal nucleating agent is preferable to suppress such problems.

In a toner having an amorphous resin and a crystalline resin, a release agent, and an organic nucleating agent in the binder resin, the organic nucleating agent needs to be compatible with each other to some extent in order to act on the crystalline resin. is there. On the other hand, it is preferable that the release agent is incompatible with the binder resin and the nucleating agent because the release agent oozes out from the toner and exhibits releasability. However, the compatibility relationship is the binder resin-organic nucleating agent-release agent, and the organic nucleating agent is in a position where it is more compatible with the release agent than the binder resin. For this reason, it has been found that depending on the degree of compatibility between the release agent and the organic nucleating agent, the respective functions are less likely to be exhibited, and the releasability is inhibited or recrystallization by the nucleating agent is inhibited.
On the other hand, since there is a high demand for higher image quality, the toner tends to have a smaller particle size, and it is necessary to obtain a toner that does not have any problems in developability and transferability even when the particle size is further reduced.
The organic nucleating agent may also be a release agent and has similar characteristics to the release agent. Therefore, the content of the organic nucleating agent in the toner increases, and when it is present on the toner surface in a large amount, the fluidity is lowered, the photoconductor filming, and in the case of a two-component developer, carrier spent is more likely to occur. As described above, since a large amount of the organic nucleating agent leads to deterioration of image quality, it is necessary that the nucleating agent and the release agent are in a state in which their functions are easily expressed in an appropriate amount.

Japanese Patent No. 3449995 JP 2003-167384 A JP 2004-151535 A JP 2002-72567 A JP 2004-309517 A

  Accordingly, the present invention has been made in view of the above-described problems, and the problem is that the toner, the image forming apparatus, and the process that can be fixed at a low temperature, ensure hot offset resistance and blocking resistance, and obtain high image quality. It is to provide a cartridge. Further, it is to provide a toner having no problem in storage stability of a fixed image, and particularly to provide a toner, an image forming apparatus, and a process cartridge that have no problem in image storage immediately after double-sided printing.

The features of the present invention, which is a means for solving the above problems, are listed below.
In order to efficiently express the functions of the organic nucleating agent and the release agent, the degree of compatibility between the organic nucleating agent and the release agent is affected. The degree of compatibility between the organic nucleating agent and the release agent can be determined by observing the DSC exothermic peak measured when the temperature of the melted product is once lowered, and the exothermic peak (or melting point) of the nucleating agent alone. On the other hand, the exothermic peak tends to shift to a low temperature side. In other words, the relationship between the nucleating agent and the release agent is such that the temperature range of the peak shift to the low temperature side becomes small, so that the performance of the toner containing the crystalline polyester can be maximized. As a result, the inventors have found it important and have arrived at the present invention.
That is, the toner of the present invention is a toner having at least a binder resin, a colorant, a release agent, and an organic crystal material, and the binder resin includes at least an amorphous resin and a crystalline resin. The solidification point TcD of the organic crystal material is higher than the melting point TmA of the crystalline resin, and the composition obtained by blending and melting the organic crystal material and the release agent at a mass ratio of 1: 1 is heated at 170 ° C. The maximum exothermic peak temperature Tx derived from the organic crystal material in the DSC temperature drop chart has a relationship of TcD−8 ≦ Tx ≦ TcD (1).
In addition, the toner of the present invention has a maximum heat generation derived from an organic crystal material in a DSC temperature decrease chart after a temperature increase of 170 ° C. of a composition obtained by blending and melting the organic crystal material and a release agent at a mass ratio of 1: 1. The peak temperature Tx has a relationship of TcD−4 ≦ Tx ≦ TcD (2).
The toner of the present invention is characterized in that the releasing agent has a melting point TmC lower than the melting point TmA of the crystalline resin.
In the toner of the present invention, the organic crystal material is selected from fatty acid metal salts and fatty acid amides.
In the toner of the present invention, the organic crystalline material has a melting point TmD of 150 ° C. or lower.
The toner of the present invention is characterized in that the difference between the melting point TmD and the freezing point TcD of the organic crystal material is within 10 ° C.
The toner of the present invention is characterized in that the crystalline resin has a melting point TmA of 100 to 130 ° C.
The toner of the present invention is characterized in that the release agent is selected from synthetic ester waxes and silicone waxes.
In the toner of the present invention, the releasing agent has a melting point TmC of 70 to 90 ° C.
In the toner of the present invention, the toner has a weight average particle diameter of 3 to 6.5 μm, and a ratio (D ₄ / D ₁ ) between the weight average particle diameter (D ₄ ) and the number average particle diameter (D ₁ ). ) Is in the range of 1.00 to 1.40.

An image forming apparatus according to the present invention includes an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using toner. An image forming apparatus comprising: a developing unit that develops a visible image; a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transferred image transferred to the recording medium. forming apparatus is characterized by the use of the toner.

The process cartridge of the present invention, at least chromatic a latent electrostatic image bearing member is developed with the toner was an electrostatic latent image formed on the latent electrostatic image bearing member and a developing means for forming a visible image It can be mounted on an image forming apparatus.

As described above, in the toner of the present invention, the functions of the organic nucleating agent and the release agent can be efficiently expressed, the toner can be fixed at a low temperature, and hot offset resistance in actual fixing can be achieved. Further, blocking resistance when used in the image forming apparatus can be ensured, and high image quality can be stably obtained over a long period of time.
Furthermore, in the image forming apparatus and the process cartridge of the present invention, there is no problem with the storage stability of the fixed image, and in particular, an image immediately after double-sided printing can be used for a long period of time.

The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.
The crystalline polyester (A) has a property that the melt viscosity rapidly decreases in the vicinity of the melting point, but the melting point is higher than the temperature at which the melt viscosity of the amorphous resin starts to decrease and is a hard resin until it melts. .
The toner of the present invention not only achieves both low-temperature fixability and hot offset resistance by functional separation of the sharp melt property of the crystalline polyester (A) and the elasticity of the amorphous polyester, but also the crystalline polyester (A). It exhibits sufficient low-temperature fixability due to partial miscibility of amorphous polyester and amorphous polyester. Moreover, blocking resistance is also ensured by presence of crystalline polyester (A) which maintained crystallinity. Furthermore, sufficient hot offset resistance is ensured by the seepage of the release agent.
Here, for the presence of crystalline polyester that maintains crystallinity, the inclusion of an organic crystal material is effective. For this to fully function, it is important that the degree of compatibility with the release agent is low. is there.
Therefore, in the crystalline resin, the organic crystalline material, and the release agent contained in the toner of the present invention, the freezing point TcD of the organic crystalline material is higher than the melting point TmA of the crystalline resin, and the organic crystalline material and the release agent are released. The maximum exothermic peak temperature Tx derived from the organic crystal material in the DSC temperature decrease chart after the temperature increase of 170 ° C. of the composition obtained by blending and melting the agent at a mass ratio of 1: 1 is preferably in the relationship of the following formula (1). . More preferably, it is in the relationship of the following formula (2).
TcD-8 ≦ Tx ≦ TcD (1) Equation TcD-4 ≦ Tx ≦ TcD (2) Equation

  The organic crystal material is a nucleating agent that first solidifies into many seed crystals when the molten toner cools, and promotes recrystallization of the crystalline resin. Therefore, it is necessary to exist as a seed crystal at a temperature higher than that at which the crystalline resin solidifies, and if it solidifies at a temperature higher than the melting point of the crystalline resin, it is likely to become a seed crystal. However, in actuality, the organic crystal material is lower than the solidification temperature of the organic crystal material alone due to the degree of compatibility with other materials. Partial compatibility with the crystalline resin is necessary to act on the crystalline resin to promote recrystallization, but partial compatibility with the release agent is necessary to release the part in order to obtain releasability. Reduces the amount of mold and reduces hot offset resistance. Moreover, in order to reduce the quantity which functions as a nucleating agent and to reduce the number of seed crystals, blocking resistance is reduced. Thus, the partial compatibility with the release agent hinders compatibility between low-temperature fixability, hot offset resistance, and blocking resistance. Therefore, it is better that the organic crystal material and the release agent are not compatible with each other as much as possible. The exothermic peak temperature derived from the organic crystal material when both are melted is higher than the exothermic peak temperature when the organic crystal material alone is melted. Should not drop significantly. When Tx is smaller than TcD-8, a large amount of crystalline polyester that retains crystallinity is unlikely to be present, and blocking resistance and resistance are likely to be insufficient. In addition, the release agent that can be oozed out tends to decrease, and the hot offset resistance tends to be insufficient.

The organic crystal material in the toner of the present invention is solidified at a temperature equal to or higher than the melting point of the crystalline resin. However, the organic crystal material having a high freezing point also has a high melting point. It tends to hinder the fixability. Therefore, the melting point of the organic crystal material is preferably 150 ° C. or less. Therefore, since the organic crystalline material has a freezing point equal to or higher than the melting point of the crystalline resin without excessively high melting point, the difference between the melting point and the freezing point is preferably small, and particularly preferably within 10 ° C. The smaller this difference is, the more difficult it is to inhibit the low-temperature fixability and the early presence of the seed crystal, making it easier to achieve both low-temperature fixability and blocking resistance.
In a toner in which a crystalline resin that retains crystallinity is dispersed to ensure blocking resistance, the melting point of the crystalline resin has a large influence, and therefore a higher melting point is preferable. On the other hand, it is preferable that the crystalline resin has a low melting point because the melting temperature of the incompatible and dispersed crystalline resin affects the low-temperature fixability. Further, since the toner has a low Tg and is fixed at a low temperature due to partial compatibility between the crystalline resin and the amorphous resin, a low melting crystalline resin that tends to have many compatible parts with the amorphous resin is preferable. Therefore, the melting point of the crystalline resin is preferably as low as possible within a range that can satisfy the blocking resistance, and is preferably 80 to 130 ° C. More preferably, it is 100-130 degreeC.
The mold release agent for ensuring the hot offset resistance must exude from the toner and exhibit the mold release property before the melt viscosity of the toner decreases and the hot offset is likely to occur. In addition, it is preferable that the release agent is melted in the vicinity of the melting point of the crystalline resin where the melt viscosity is likely to rapidly decrease. Therefore, the melting point of the release agent is preferably not more than the melting point of the crystalline resin. Furthermore, the melting point of the release agent is more preferably 70 to 90 ° C. in order to prevent blocking at low temperature and to ensure blocking resistance.

Tx in the present invention is the maximum exothermic peak temperature derived from an organic nucleating agent that appears in a temperature drop chart after a 170 ° C. temperature increase in DSC of a composition obtained by blending and melting an organic crystal material and a release agent at a mass ratio of 1: 1. It is.
In the compounded melt composition of the organic crystal material and the release agent, a 1: 1 compound of both is put into a sample bottle and heated at 180 ° C., and when these are melted, the heating is stopped and the mixture is stirred with a spatula at room temperature. It is obtained by natural cooling. The temperature drop chart in DSC is a temperature drop rate of 10 ° C. with no holding time after heating up to 20-170 ° C. at 10 ° C./min using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation). When cooled to 0 ° C. per minute.
In the present invention, the melting point of the crystalline resin, the melting point of the release agent, the melting point of the organic crystal material and the freezing point thereof are measured by DSC. That is, using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation), the temperature was raised to 20 to 150 ° C. (the organic crystal material was 170 ° C.) at 10 ° C./min, and without holding time, The temperature is lowered to 0 ° C. at a temperature lowering rate of 10 ° C./min, and again raised to 150 ° C. (170 ° C. for organic crystal material) at 10 ° C./min without holding time. A second maximum endothermic peak temperature during Atsushi Nobori at this time as the melting point, and the freezing point of maximum exothermic peak temperature during the temperature decrease.

前記式中、Ｒは炭素数２〜２０の２価炭化水素基を示す。好ましくは炭素数２〜２０、より好ましくは２〜４の肪族基２価炭化水素基である。ｎは２〜２０、好ましくは２〜６の整数である。前記２価化炭化水素基としては、結晶性を損なわないものであればどのようなものでもよく、特に制約されない。この２価炭化水素基には、脂肪族２価炭化水素基及び芳香族２価炭化水素基が包含されるが、好ましい２価炭化水素基は、脂肪族２価炭化水素基である。脂肪族２価炭化水素基には、直鎖状のもの及び分岐鎖状のものが包含されるが、好ましくは直鎖状脂肪族２価炭化水素基である。本発明の場合、Ｒは、特に、直鎖状不飽和脂肪族２価炭化水素基であるのが好ましい。前記２価炭化水素基の具体例を示すと、エチレン基、ｎ−プロピレン基、ビニレン基、プロペニレン基、イソプロペニレン基、ｎ−ブチレン基、フェニレン基、シクロヘキシレン基等が挙げられる。 The crystalline resin can be appropriately selected according to the purpose, and includes an alcohol component containing a diol compound having 2 to 20 carbon atoms and derivatives thereof, an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an alicyclic ring. A polyester resin synthesized using a polyvalent carboxylic acid compound such as a formula dicarboxylic acid and an acid component containing these derivatives is preferred.
In particular, a polyester resin containing a structural unit represented by the following general formula (1) is preferable in that a toner having high sharp melt property can be formed.

In said formula, R shows a C2-C20 bivalent hydrocarbon group. Preferably it is a C2-C20, More preferably, it is a C2-C4 aliphatic group bivalent hydrocarbon group. n is an integer of 2 to 20, preferably 2 to 6. The divalent hydrocarbon group is not particularly limited as long as it does not impair the crystallinity. The divalent hydrocarbon group includes an aliphatic divalent hydrocarbon group and an aromatic divalent hydrocarbon group, and a preferred divalent hydrocarbon group is an aliphatic divalent hydrocarbon group. The aliphatic divalent hydrocarbon group includes straight-chain and branched-chain groups, and is preferably a straight-chain aliphatic divalent hydrocarbon group. In the present invention, R is particularly preferably a linear unsaturated aliphatic divalent hydrocarbon group. Specific examples of the divalent hydrocarbon group include an ethylene group, an n-propylene group, a vinylene group, a propenylene group, an isopropenylene group, an n-butylene group, a phenylene group, and a cyclohexylene group.

The polyester resin (A) comprises (i) a polyvalent carboxylic acid component comprising a divalent carboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.), and (ii) It can be produced by subjecting a polyhydric alcohol component comprising a diol to a polycondensation reaction by a conventional method. In this case, a tri- or tetravalent carboxylic acid can be added to the polyvalent carboxylic acid component. In addition, a trivalent or tetravalent alcohol can be added to the polyvalent diol component.
Specific examples of the divalent carboxylic acid include maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, 1,4-n-butenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, suberic acid, and sebacin. Examples include acids, cyclohexanedicarboxylic acid, terephthalic acid and the like. Specific examples of the diol include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. The addition amount of the trivalent to tetravalent carboxylic acid used as necessary is usually 40 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, based on the total carboxylic acid. The polyester to be added is appropriately added within the range having crystallinity.
Specific examples of the trivalent to tetravalent carboxylic acid that can be added as needed include trimellitic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1, 2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octane Examples thereof include polyvalent carboxylic acids such as tetracarboxylic acid.

  A trivalent or higher polyhydric alcohol can be added to the polyhydric alcohol component, if necessary, in addition to a small amount of an aliphatic branched dihydric alcohol or cyclic dihydric alcohol. The amount of addition is 40 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, based on the total alcohol, and is suitably added within the range in which the resulting polyester has crystallinity. Examples of polyhydric alcohol added as needed include 1,4-bis (hydroxymethyl) cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin and the like.

The crystallinity of the crystalline polyester (A) can be confirmed by the presence of three or more diffraction peaks at a position of 2θ = 19 to 25 ° in a diffraction pattern by a powder X-ray diffractometer. The diffraction pattern can be confirmed by measuring powder using an XRD standard sample holder under the following conditions using an X-ray diffractometer (“RINT-1100”; manufactured by Rigaku Electric Co., Ltd.). That is, tube: Cu, tube voltage / current: 50 KV-30 mA, goniometer: wide-angle goniometer, sampling width: 0.020 °, scanning speed: 2.0 ° / min, scanning range: 5-50 °, diffraction Presence of a peak can be determined by performing a peak search on a smoothed score of 11 and determining the presence or absence from the detected peak.
The content of the crystalline polyester is preferably 5 to 40% by mass with respect to the binder resin. More preferably, it is 5-30 mass%. When the amount is less than this range, not only the toner does not easily have a crystalline portion, but also low temperature fixability may not be obtained. On the other hand, if it is larger than this range, blocking resistance and hot offset resistance may not be ensured. In addition, the dispersion of the toner constituent materials becomes insufficient, which may cause problems in developability and transferability.

Examples of the amorphous resin include styrene, α-methylstyrene, chlorostyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene. -Styrene resins such as maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, polyester resin, vinyl chloride resin, rosin modification Examples thereof include maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, xylene resin, petroleum resin, and petroleum resin to which hydrogen is added.
In particular, a polyester resin is preferable in that it is easily partially compatible with a crystalline polyester that is a preferred crystalline resin of the present invention. This polyester is synthesized from a polyhydric alcohol and a polycarboxylic acid. The polyhydric alcohol and the polyhydric carboxylic acid are not particularly limited and may be appropriately selected depending on the intended purpose. For example, components used for the crystalline polyester resin can be suitably used. In addition, an alkylene oxide adduct of bisphenol A, isophthalic acid, terephthalic acid, and derivatives thereof can be used. These resins may be used alone or in combination of two or more. In the present invention, an aromatic diol and an aromatic dicarboxylic acid are particularly preferable in order to obtain moderate partial compatibility with the crystalline polyester, and in particular, an alkylene oxide adduct of bisphenol A and derivatives thereof, isophthalic acid, terephthalic acid, and these A polyester comprising a derivative is preferred.

The glass transition temperature of the amorphous resin is preferably 40 to 70 ° C. When the glass transition temperature is less than 40 ° C., the heat-resistant storage stability of the toner is remarkably deteriorated and blocking may occur, and when it exceeds 70 ° C., the low-temperature fixability of the toner may be deteriorated. The glass transition temperature of the amorphous resin was raised to 20 to 150 ° C. at 10 ° C./min using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation), and then the temperature was lowered without holding time. When measuring to cool to the measurement start temperature at a rate of 10 ° C / min and then increasing again to 150 ° C at a rate of temperature increase of 10 ° C / min, the endothermic curve at the second temperature rise is on the lowest temperature side The peak to be obtained can be obtained by the tangent method.
The flow tester 1/2 outflow temperature (F _1/2 ) of the amorphous resin is preferably 120 to 160 ° C., more preferably 125 to 145 ° C. If the temperature is lower than 120 ° C, the compatibility with the crystalline resin may be too high to ensure hot offset resistance or blocking resistance. If the temperature is higher than 160 ° C, the resins are not sufficiently kneaded with each other. In some cases, the dispersibility of the constituent material is deteriorated, or the toner does not become a low-temperature fixable toner. When the F _{1/2 of the} amorphous resin is relatively high such as 135 to 160 ° C., an amorphous resin having a lower F _1/2 is used in combination to improve the dispersibility with the crystalline resin. However, F _1/2 of the amorphous resin used in combination is preferably 90 ° C. or higher so as not to impair hot offset resistance and blocking resistance.
The flow tester 1/2 outflow temperature (F _1/2 ) can be determined from a flow curve measured using an elevated flow tester CFT500 type (manufactured by Shimadzu Corporation). The T _1/2 is a stroke when a sample of 1 cm ³ is melted and discharged under the conditions of a die hole diameter of 1 mm, a die hole length of 1 mm, a pressure of 10 kgf / cm ² , and a temperature increase rate of 3 ° C./min. This is the temperature at which the stroke change amount from the start point to the outflow end point is ½.

There is no restriction | limiting in particular as a mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include low molecular weight polyolefin waxes such as low molecular weight polyethylene wax and low molecular weight polypropylene wax; synthetic hydrocarbon waxes such as Fischer-Tropsch wax; synthetic ester waxes; beeswax, carnauba wax, candelilla wax, Natural waxes such as rice wax and montan wax; petroleum waxes such as paraffin wax and microcrystalline wax; silicone waxes; higher fatty acids and metal salts thereof, higher fatty acid amides, and various modified waxes thereof. These may be used individually by 1 type and may use 2 or more types together.
In the present invention, synthetic ester waxes and silicone waxes are particularly preferred in that it is easy to select those that are not compatible with the organic crystal material, and that the proportion of low-temperature melting components that tend to deteriorate blocking resistance can be reduced. preferable.
The synthetic ester wax is, for example, a linear saturated monocarboxylic acid having 14 to 30 carbon atoms and a linear saturated monohydric alcohol having 14 to 30 carbon atoms, or a 2 to 6-valent polyhydric alcohol having 2 to 30 carbon atoms. Is obtained from
The silicone wax is a C 16-300 hetero atom containing a C 1-6 alkyl group or C 6-10 aryl group and a C 16-300 long chain alkyl group or a hetero atom 1-10. An organopolysiloxane modified with a long-chain organic acid.
There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 1-20 mass parts is preferable, and 3-10 mass parts is more preferable. When the content exceeds 20 parts by mass, the fluidity of the toner is deteriorated, and problems such as contamination of other members may be observed.

Examples of the organic crystal material include benzoic acid metal salts, phosphoric acid ester metal salts, fatty acid metal salts, and fatty acid amides, and those selected from fatty acid metal salts and fatty acid amides are particularly preferable. Examples of the fatty acid include fatty acids having 1 to 24 carbon atoms, preferably 10 to 22 carbon atoms, and may be saturated, unsaturated, linear or branched, and linear fatty acids are particularly preferable. More preferred are lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and oleic acid, with stearic acid being particularly preferred. Examples of these fatty acid salts include calcium, magnesium, zinc, and aluminum.
The content of these organic crystal materials is preferably 10 to 45% by mass, particularly preferably 15 to 35% by mass with respect to the crystalline resin. When the amount is less than this range, it is difficult to obtain the effect of promoting recrystallization of the crystalline resin, and it is difficult to ensure blocking resistance. When the amount is larger than this range, the compatible portion between the crystalline resin and the amorphous resin becomes too small, and sufficient low-temperature fixability may not be obtained. Even within this range, it is preferable not to exceed 8% by mass with respect to the binder resin in the toner. If the amount of the organic crystal material is too large, the photosensitive filming and carrier spent are likely to occur and the developability may be deteriorated.

The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithobon.
These may be used individually by 1 type and may use 2 or more types together.

The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass.
When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed, and when the content exceeds 15% by mass, a poor dispersion of the pigment in the toner occurs. The characteristics may be degraded.
The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, a styrene copolymer, polymethyl methacrylate, polybutyl methacrylate , Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic ring Aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the polymer of styrene or a substituted product thereof include polyester resin, polystyrene, poly p-chlorostyrene, polyvinyl toluene, and the like. Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene- Butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene An acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - maleic acid ester copolymer, and the like.
The masterbatch can be produced by mixing or kneading the masterbatch resin and the colorant under high shear. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. The so-called flushing method is also preferable in that the wet cake of the colorant can be used as it is, and it does not need to be dried. This flushing method is a method of mixing or kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, and transferring the colorant to the resin side to remove moisture and organic solvent components. For the mixing or kneading, for example, a high shear dispersion device such as a three-roll mill is preferably used.

  As other components constituting the toner, inorganic fine particles, resin fine particles, a charge control agent, a fluidity improver, a cleaning property improver, a magnetic material, and the like can be contained as other components. There is no restriction | limiting in particular in these, According to the objective, it can select suitably.

The inorganic fine particles are not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, titanate Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples thereof include silicon and silicon nitride. These may be used individually by 1 type and may use 2 or more types together.
The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm. The specific surface area of the inorganic fine particles by BET method is preferably 20 to 500 m ² / g.
The content of the inorganic fine particles in the toner is preferably 0.01 to 5.0% by mass, and more preferably 0.01 to 2.0% by mass.
The inorganic fine particles can be suitably used as an external additive for the toner.

The resin fine particles are not particularly limited and can be appropriately selected from known resins according to the purpose, and may be a thermoplastic resin or a thermosetting resin, such as a vinyl resin, Examples thereof include polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin.
These may be used individually by 1 type and may use 2 or more types together. Among these, at least one selected from vinyl resins, polyurethane resins, epoxy resins, and polyester resins is preferable because an aqueous dispersion of fine spherical resin particles can be easily obtained.

The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. For example, a styrene- (meth) acrylic acid ester resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylic acid ester polymer. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.
Moreover, as the resin fine particles, a copolymer comprising a monomer having at least two unsaturated groups can be used.
The monomer having at least two unsaturated groups is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a sodium salt of ethylene oxide methacrylate adduct sulfate (“Eleminol RS-30”). "; Manufactured by Sanyo Chemical Industries Ltd.), divinylbenzene, 1,6-hexanediol acrylate and the like.

The volume average particle diameter of the resin fine particles is preferably 20 to 400 nm, and more preferably 30 to 350 nm. When the volume average particle size is less than 20 nm, the resin fine particles remaining on the surface of the toner may be formed into a film, or the entire surface of the toner may be covered densely. Adhesiveness with fixing paper as a transfer material may be hindered, and the minimum fixing temperature may be increased. If it exceeds 400 nm, the resin fine particles inhibit the exudation of the wax component, and sufficient releasability is obtained. It may not be obtained and an offset may occur.
The resin coverage of the resin fine particles is preferably 75 to 100%, more preferably 80 to 100%. When the toner coverage is less than 75%, the storage stability of the toner is deteriorated, and blocking may occur during storage or use.
The content of the resin fine particles in the toner is preferably 0.5 to 8.0% by mass, and more preferably 0.6 to 7.0% by mass. When the content is less than 0.5% by mass, the storability of the toner deteriorates, and blocking may be observed during storage or use. When the content exceeds 8.0% by mass, The resin fine particles hinder the seepage of the wax, so that sufficient releasability cannot be obtained and offset may occur.

  The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide And a simple substance of phosphorus or a compound thereof, a simple substance of tungsten or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferred. These may be used individually by 1 type and may use 2 or more types together. There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, zirconium etc. are mentioned.

Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), fourth Copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (manufactured by Nippon Carlit), quinacridone, azo pigments, other sulfonic acid groups, carbo Sill group, polymer compounds having a functional group such as quaternary ammonium salts, and the like.
The charge control agent may be melted and kneaded with the master batch and then dissolved or dispersed, or may be added together with each component of the toner when directly dissolving or dispersing in the organic solvent, or The toner particles may be fixed on the toner surface after production.

  The content of the charge control agent in the toner varies depending on the type of the binder resin, the presence / absence of an additive, a dispersion method, and the like, and cannot be generally specified. On the other hand, 0.1-10 mass parts is preferable, and 1-5 mass parts is more preferable. When the content is less than 0.1 parts by mass, the charging characteristics of the toner may be deteriorated. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is increased. , And the electrostatic attraction force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

  The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil.

  The cleaning improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium, and includes, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and the like. Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as methyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

  The method for producing the toner of the present invention is not particularly limited and may be appropriately selected from known methods according to the purpose. For example, a pulverization method in which the material forming the toner is melt-kneaded and then pulverized and classified. And polymerization methods.

The toner of the present invention is not particularly limited with respect to various physical properties such as shape and size, and can be appropriately selected according to the purpose. However, the following glass transition temperature, volume average particle diameter, etc. It is preferable to have.
The glass transition temperature of the toner is preferably 35 to 70 ° C, and more preferably 45 to 60 ° C. In particular, the glass transition temperature of the toner is preferably lower than the glass transition temperature of the amorphous polyester in order to develop low-temperature fixing due to partial compatibility between the crystalline polyester and the amorphous polyester. When the glass transition temperature of the toner is lower than this range, the blocking resistance tends to be insufficient, and when it is high, it is difficult to obtain low-temperature fixability.
The glass transition temperature of the toner is an endothermic curve when the temperature is raised to 20 to 170 ° C. at 10 ° C./min using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation), and is present on the lowest temperature side. The peak to be obtained can be obtained by the tangent method.
Further, the endothermic peak derived from the organic crystal material is present in the endothermic curve, so that the organic crystal material can sufficiently exhibit the function as a nucleating agent without being excessively compatible with the release agent in the toner. The endothermic peak is lower than the melting point TmD of the organic crystal material, and the organic crystal material is partially compatible with the crystalline resin and acts as a nucleating agent. It shows that it is doing. The peak temperature is preferably lower than 140 ° C. When the temperature is higher than 140 ° C., sufficient low-temperature fixability may not be obtained.

The volume average particle diameter of the toner is preferably 2.5 to 10 μm, and more preferably 2.5 to 7 μm, for example. When the volume average particle size is less than 2.5 μm, in the two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In a one-component developer, toner filming to the developing roller and toner fusion to a member such as a blade are likely to occur because the toner layer is thinned. Therefore, it becomes difficult to obtain a high-quality image, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.
The volume average particle size can be measured using, for example, a particle size measuring device “Multisizer II” manufactured by Beckman Coulter.

  The colorant of the toner of the present invention is not particularly limited and can be appropriately selected according to the purpose, and can be at least one selected from black toner, cyan toner, magenta toner and yellow toner, Each color toner can be obtained by appropriately selecting the type of the colorant.

The toner of the present invention is used as a developer for the image forming apparatus of the present invention. The developer contains at least the toner of the present invention, and other components appropriately selected such as a carrier. The developer may be a one-component developer or a two-component developer. However, when it is used for a high-speed printer or the like corresponding to the recent improvement in information processing speed, the service life is improved. In view of the above, the two-component developer is preferable.
In the case of the one-component developer using the toner according to the present invention, the toner particle diameter hardly fluctuates even if the balance of the toner is performed, and the filming of the toner on the developing roller or the toner is made thin. Therefore, toner is not fused to a member such as a blade, and good and stable developability and images can be obtained even when the developing device is used (stirred) for a long time. Further, in the case of the two-component developer using the toner of the present invention, even if the balance of the toner over a long period of time is performed, the fluctuation of the toner particle diameter in the developer is small, and even in the long-term stirring in the developing device, Good and stable developability can be obtained.

There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.
There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, 50-70 emu / g manganese-strontium (Mn-Sr) type material, manganese-magnesium (Mn-) Mg) -based materials and the like are preferable, and high magnetization materials such as iron powder (100 emu / g or more) and magnetite (75 to 85 emu / g) are preferable in terms of securing image density. Further, a weakly magnetized material such as a copper-zinc (Cu—Zn) -based (30 to 80 emu / g) is advantageous in that it can weaken the contact with the photoconductor in which the toner is in a spiked state and is advantageous in improving the image quality. Is preferred. These may be used alone or in combination of two or more.
The core material has a volume average particle diameter of preferably 10 to 150 μm, more preferably 40 to 100 μm.
When the average particle diameter (volume average particle diameter (D50)) is less than 10 μm, in the distribution of carrier particles, the fine powder system increases, the magnetization per particle is lowered, and carrier scattering may occur. If the thickness exceeds 150 μm, the specific surface area may be reduced and toner scattering may occur. In the case of a full color with many solid portions, the reproduction of the solid portions may be particularly poor.

The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, Polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride And a copolymer of vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, and a silicone resin. These may be used individually by 1 type and may use 2 or more types together.
Examples of the amino resins include urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamide resins, and epoxy resins. Examples of the polyvinyl resins include acrylic resins, polymethyl methacrylate resins, and poly resins. Examples include acrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, and polyvinyl butyral resin. Examples of the polystyrene resin include polystyrene resin and styrene acrylic copolymer resin. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin.

The resin layer may contain conductive powder or the like as necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.
For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the application method include an immersion method, a spray method, and a brush coating method.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cersol butyl acetate, etc. are mentioned.
The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, The method of using, the method of using a microwave, etc. are mentioned.
The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass.
When the amount is less than 0.01% by mass, the uniform resin layer may not be formed on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes thick. In some cases, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  When the developer is the two-component developer, the content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 90 to 98% by mass Is preferable, and 93-97 mass% is more preferable.

Since the developer of the present invention contains the toner of the present invention, it is possible to achieve a balance between chargeability and fixability during image formation, and stably form high-quality images. .
The developer of the present invention can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method. The image forming apparatus can be particularly suitably used.

  The image forming apparatus of the present invention includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image as an electrophotographic developer. And developing means for forming a visible image by developing the image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium. The toner of the present invention is used as a photographic developer. The electrostatic latent image forming unit may include an exposure unit that performs imagewise exposure on the electrostatic latent image carrier based on read image information from an image reading unit that reads an original image. In order to prepare for the next image forming cycle after the completion of one image forming cycle, a cleaning means for removing the remaining developer remaining on the electrostatic latent image carrier may be provided.

An image forming apparatus using the toner of the present invention as a developer will be described.
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem type image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

The developing device 44 of the image forming unit 18 uses a developer containing the above toner. In the developing device 44, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.
Note that the image forming unit 18 of the present invention includes a fixing device 25 including a fixing roller 251 and a pressure roller 252 as fixing members, and a cleaning roller 257 that collects residual toner attached on the pressure roller 252. use. As shown in the drawing, the toner on the recording paper is subjected to heat and pressure in the nip between the fixing roller 251 and the pressure roller 252 in the fixing device 25, and the heat causes the toner to be in a molten state, resulting in viscosity and elasticity. At the same time, it is spread and fixed on the recording paper by receiving pressure.
The fixing cleaning roller 256 provided on the fixing roller 251 moves to the fixing roller 251 when the toner fixed on the recording paper is melted and becomes low in viscosity, and becomes residual toner on the fixing roller 251. Collect the food. Accordingly, the residual toner is prevented from re-adhering on the recording paper due to the rotation of the fixing roller 251 and becoming dirty on the image.

It is difficult to completely remove the residual toner on the fixing roller 251 by the fixing cleaning roller 256, and a part of the toner is further transferred from the fixing roller 251 to the low-temperature pressure roller 252.
The fixing device 25 of the present invention is provided with a cleaning roller 257 on the pressure roller 252 and collects toner transferred onto the pressure roller 252. Thereby, it is possible to prevent the residual toner on the pressure roller 252 from reattaching to the back surface of the recording paper due to the rotation of the pressure roller 252.
The toner recovered by the cleaning roller 257 is melted and kneaded by continuing to receive driving and fixing heat from the fixing roller 251 via the pressure roller 252.
When the toner amount on the cleaning roller 257 increases, the adhesion force to the pressure roller 257 becomes larger than the elastic force of the toner itself, and the toner melted on the cleaning roller 257 is reversed to the pressure roller 252. The toner reversely rotated on the pressure roller 252 is not preferable because it is further reversely transferred onto the recording paper.
Since the toner of the present invention has good fixability, the amount of toner adhering to the cleaning roller 257 can be reduced, and the melting from the roller 257 to the pressure roller 252 can be reduced.

  Further, the developing device 44 can be a process cartridge that is integrally supported with the photosensitive member 40 and is detachably formed on the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15, 16 is rotated by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, these single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, the sheet is fed out from one of the paper cassettes 44 provided in the paper bank 43 in multiple stages, and the separation roller 45 Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the Example of this invention, the crystalline resin, the amorphous resin, the organic crystal material, and the mold release agent used the thing of Table 1-4.
In Tables 1 and 2, the presence of the powder X-ray diffraction peak indicates the presence or absence of a peak at a position of 2θ = 19 to 25 ° of the X-ray diffraction pattern.

表２において、ＢＰＯ-ＥＯはビスフェノールＡのエチレンオキサイド付加物であり、ＢＰＯ-ＰＯはビスフェノールＡのプロピレンオキサイド付加物である。

In Table 2, BPO-EO is an ethylene oxide adduct of bisphenol A, and BPO-PO is a propylene oxide adduct of bisphenol A.

表３において、離型剤Ｃ５の構造式（１）のワックスは、下記の化合物である。

In Table 3, the wax of the structural formula (1) of the release agent C5 is the following compound.

Example 1
Toner base constituent material Crystalline resin A 120 parts Amorphous resin B 180 parts Release agent C1 5 parts Organic crystal material D1 5 parts Carbon black 10 parts Note that 1: 1 of release agent C1 and organic crystal material D1 (Mass ratio) Tx of the blended molten product is 133.3 ° C. (TcD-7.5).
Table 4 shows organic crystal materials used in the following examples.

The toner base material was charged in a Henschel mixer “MF20C / I type” (Mitsui Miike Processing Machine Co., Ltd.), sufficiently stirred and mixed, then kneaded by a twin-screw extruder manufactured by Toshiba Machine Co., Ltd. and cooled. Next, the weight average particle diameter (D4) is 7.0 ± 0.5 μm, and the ratio (D4 / D1) of the weight average particle diameter to the number average particle diameter (D1) is 1.10 to 1.20. Crushing and classification were performed to prepare a black toner base material. Here, the kneading was performed such that the temperature of the kneaded product at the exit of the twin-screw extruder was about 125 ° C.
A yellow toner base was produced in the same manner and in the same manner as the black toner except that carbon black in the toner constituent material was changed to 7 parts of disazo yellow pigment.
A cyan toner base was produced in the same manner and in the same manner as the black toner except that carbon black in the toner constituent material was changed to 4 parts of copper phthalocyanine pigment.
A magenta toner base was prepared in the same manner and in the same manner as the black toner except that carbon black in the toner constituent material was changed to 5 parts of naphthol-based magenta pigment.
To each color matrix, 1.0% by mass of hydrophobic silica and 0.9% by mass of acid value titanium were added and mixed to prepare toners of black, yellow, cyan and magenta in Example 1.
Next, 7 parts by mass of each color toner and 93 parts by mass of a silicone-coated ferrite carrier having an average particle diameter of 45 μm coated with a silicone resin were stirred with a tumbler mixer to prepare each color developer having an appropriate charge amount.

従来以上の低温定着性であり、耐ホットオフセット性、耐ブロッキング性に問題のないトナーが得られた。また鮮明なフルカラー画像が得られ、画像の保存性も問題ないものであった。 Table 5 shows the evaluation results of the toner and developer of Example 1 and Examples 2 to 6 shown below.

A toner having a low-temperature fixability higher than before and having no problem with hot offset resistance and blocking resistance was obtained. In addition, a clear full color image was obtained, and the image storage stability was satisfactory.

The toner and developer were evaluated as follows.
Further, the evaluation results of the toner obtained by DSC measurement, and the anti-blocking property and fixability of the toner are the evaluation results of only the cyan toner.
(Blocking resistance)
About 20 g of cyan toner was put into a 20 ml glass bottle and tapped 50 times to harden the toner tightly. Subsequently, after putting it in a 50 degreeC thermostat and leaving it to stand for 24 hours, the penetration (%) was measured by the penetration test (JIS K2235-1991). The blocking resistance was evaluated based on the following criteria from the penetration (%) with respect to the toner after being solidified.
〔Evaluation criteria〕
5: 90-100%
4: 75-90%
3: 60-75%
2: 30-60%
1: 30% or less Here, if the evaluation criteria is 3 to 5, it is recognized that there is no problem in blocking resistance.

(Fixing characteristics)
The Ricoh printer Imagio Neo C385 was modified so that the set temperature and linear velocity of the fixing device could be changed. The toner, developer, and Ricoh type 6200 paper shown in the Examples were set on this, and a solid image of 1 inch square was printed by adjusting so that the adhesion amount of the solid part was 0.85 mg / cm ² .
The linear velocity of paper feed is set to 200 mm / sec, the fixing temperature is changed, and the cold offset generation temperature and hot offset generation temperature are measured. Based on the following criteria, the low temperature fixing property (cold offset generation temperature) and the hot offset resistance are measured. The property (hot offset generation temperature) was evaluated.
Cold offset generation temperature (Rank 2 is the level of conventional low-temperature fixing toner)
5 ... Less than 120 ° C 4 ... 120-130 ° C
3 ... 130-140 ° C
2 ... 140-150 ° C
1 ... 150 ℃ or more

(Hot offset generation temperature (if it is other than rank 1 or 2, there is offset resistance))
5 ... 210 ° C or higher 4 ... 200-210 ° C
3 ... 190-200 ° C
2 ... 180-190 ° C
1 ... less than 180 ° C

(Image quality, fixed image storage)
The toner, developer, and Ricoh type 6200 paper shown in the examples are set in the Ricoh printer Imagio Neo C385, and the image area is composed of 1 inch squares and characters of each color of yellow, magenta, cyan, and black, and the image area is 20%. The 10,000 images were continuously printed. Double-sided printing was performed up to the 100th sheet, and then single-sided printing was performed.

(Fixed image storage stability)
After printing 100 sheets, 20 images, which were the 81st to 100th sheets, were taken out and stored in a high-temperature bath at 50 ° C. for 24 hours under a load of 10 g / cm ² while being stacked. After the storage, the fused state of the image was evaluated.
3: There is no fusion of images and good image quality is maintained.
2: Although there is fusion of images, it is easily separated and maintains good image quality.
1: There is image fusion, and there is an image defect after separation.

(Transferability)
It was evaluated whether there was any density unevenness due to transfer failure in the solid part of the image after printing 10,000 sheets.
〔Evaluation criteria〕
5: Very good 4: Good 3: Normal 2: Bad 1: Very bad Here, if the evaluation criteria are 3 to 5, it is required that the transferability is not a problem.

(Developability)
Select arbitrary six positions on the background of the image after printing 10,000 sheets, and measure the image density at the position with a spectrometer (938 Spectrodensitometer, manufactured by X-Light). The background stain was evaluated based on the following criteria.
〔Evaluation criteria〕
5: Same as paper reflection density 4: Paper reflection density + less than 0.02 3: Paper reflection density + 0.02 to 0.04
2: Reflection density of paper +0.04 to 0.06
1: Reflection density of paper +0.06 or more Here, in a state where there is no background stain, the reflection density of the image shows a value equivalent to the reflection density of paper, and the higher the reflection density, the worse the background stain. It is recognized that

(Fine line reproducibility)
Set the toner, developer, and Ricoh type 6200 paper shown in the examples to the Ricoh printer Imagio Neo C385, and output a 1-dot grid line image of 600 dots / inch and 150 line / inch in both the main and sub-scan directions. , Line image cuts and blurs were visually evaluated in 5 stages 5 ... very good 4 ... good 3 ... normal 2 ... bad 1 ... very bad

(Example 2)
A toner and a developer are obtained in the same manner as in Example 1 using the same toner constituent material as in Example 1 except that the release agent C1 is changed to the release agent C2 in the toner constituent material in Example 1. It was. In addition, Tx of the 1: 1 (mass ratio) compounding melt product of mold release agent C2 and organic type crystal material D1 is 139.4 degreeC (TcD-1.4). The toner and developer were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5. By changing the release agent to a release agent C2 having lower compatibility with the organic crystal material D1 than the release agent C1, image storability was improved.

(Example 3)
A toner and a developer were obtained in the same manner as in Example 1 except that the crystalline resin in the toner constituent material of Example 1 was changed from A1 to A2, and the same toner constituent material as in Example 1 was used. The toner and developer were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5. By changing the crystalline resin to A2 having a higher melting point than A1, the blocking resistance of the toner was improved.

(Example 4 )
Of the toner constituent materials of Example 3, the same toner constituent material as in Example 3 was used, except that the organic crystal material was changed from 5 parts D1 to 4 parts D3. A developer was obtained. In addition, Tx of the 1: 1 (mass ratio) compounding melt product of mold release agent C1 and organic type crystal material D3 is 133.9 degreeC (TcD-7.0). The toner and developer were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5. Although the prescription amount of the organic crystal material is reduced as compared with the case of Example 3, since the organic crystal material has a small difference between the melting point and the freezing point and a large recrystallization promoting effect, the blocking resistance of the toner is improved. Also, by reducing the amount of formulation, developability and transferability were improved, and deterioration in image quality when a large number of sheets were printed was suppressed.

(Example 5 )
Of toner constituent material of Example 4, except for changing the release agent C1 to release agent C3, using the same toner constituent materials as in Example 4, the toner and developer in the same manner as in Example 1 Obtained. In addition, Tx of the 1: 1 (mass ratio) compounding melt product of mold release agent C3 and organic type crystal material D3 is 133.6 degreeC (TcD-7.3). The toner and developer were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5. The hot offset resistance was improved by lowering the melting point of the release agent.

(Example 6 )
Using the toner constituting material of Example 5 , the weight average particle diameter (D4) is 5.8 ± 0.5 μm, and the ratio of the weight average particle diameter to the number average particle diameter (D1) (D4 / D1) is 1.10. Each color-colored matrix was obtained in the same manner as in Example 1 except that pulverization and classification were performed so as to be ˜1.20. To each color matrix, 1.2% by mass of hydrophobic silica and 1.0% by mass of acid value titanium were added and mixed to prepare toners of black, yellow, cyan and magenta in Example 7. A developer was prepared using this toner in the same manner as in Example 1. The toner and developer were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5. Although the fine line reproducibility was improved by reducing the particle size, the developability and transferability were not deteriorated.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention.

10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 22 Secondary transfer device 25 Fixing device 40 Photoconductor (latent image carrier)
44 Developing device 62 Primary transfer means 100 Copying device main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (12)

A toner having at least a binder resin, a colorant, a release agent, and an organic crystal material,
The binder resin includes at least an amorphous resin and a crystalline resin,
The freezing point TcD of the organic crystalline material is higher than the melting point TmA of the crystalline resin,
The maximum exothermic peak temperature Tx derived from the organic crystal material in the DSC temperature decrease chart of the composition obtained by blending and melting the organic crystal material and the release agent at a mass ratio of 1: 1 is 170 ° C.
TcD-8 ≦ Tx ≦ TcD (1) The toner having the relationship of the following formula (1). The maximum exothermic peak temperature Tx derived from the organic crystal material in the DSC temperature decrease chart of the composition obtained by blending and melting the organic crystal material and the release agent at a mass ratio of 1: 1 is 170 ° C.
The toner according to claim 1, wherein TcD−4 ≦ Tx ≦ TcD (2) is satisfied, which is in the relationship of the following equation (2): The toner according to claim 1, wherein a melting point TmC of the release agent is lower than a melting point TmA of the crystalline resin. The toner according to claim 1, wherein the organic crystal material is selected from fatty acid metal salts and fatty acid amides. The toner according to claim 1, wherein the organic crystalline material has a melting point TmD of 150 ° C. or less. The toner according to any one of 1 to 5, wherein the difference between the melting point TmD and the freezing point TcD of the organic crystal material is within 10 ° C. The toner according to any one of claims 1 to 6, wherein the crystalline resin has a melting point TmA of 100 to 130 ° C.   The toner according to claim 1, wherein the release agent is selected from synthetic ester waxes and silicone waxes. The toner according to claim 1, wherein the release agent has a melting point TmC of 70 to 90 ° C. The toner is a weight average particle diameter of 3～6.5Myuemu, the ratio of the weight average particle diameter and _{(D 4)} to a number average particle diameter _{(D 1) (D 4 /} D 1) is 1.00 to 1. The toner according to claim 1, wherein the toner is in the range of 40. An electrostatic latent image carrier;
Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means for developing the electrostatic latent image with toner to form a visible image;
Transfer means for transferring the visible image to a recording medium;
In an image forming apparatus having fixing means for fixing a transfer image transferred to a recording medium,
An image forming apparatus using the toner according to claim 1. An electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using the toner according to claim 1 to form a visible image. Can be mounted on an image forming apparatus.
A process cartridge characterized by that.

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