JP3949526B2 - Image forming toner, image forming method, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming toner, an image forming method using the toner, and an image forming apparatus loaded with the toner.
[0002]
[Prior art]
Image formation by electrophotography is generally performed as described in various methods in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 49-23910, Japanese Patent Publication No. 43-24748, and the like. An electric latent image is formed on a photoconductor prepared using a photoconductive substance by various means, and then the latent image is developed using a developer. And then fixed by heating, pressing or solvent vapor.
[0003]
The methods for developing electrical latent images can be broadly divided into a liquid development method using a liquid developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, a cascade method, a magnetic brush method, and a powder cloud. There is a dry development method using a dry developer (hereinafter referred to as toner) prepared by dispersing a colorant such as carbon black in a natural or synthetic resin as in the method, and in recent years, the dry development method has been widely used. ing.
[0004]
In dry electrophotographic developing machines, the heat-heat roller fixing method is generally widely used because of its energy efficiency. However, due to the recent demand for energy saving, the heat used for fixing the toner is lowered while maintaining the properties such as pulverization, charging and offset resistance required for the toner while lowering the fixing temperature of the toner itself. Technology that reduces energy is needed to reduce the energy consumed by dry electrophotographic processors.
[0005]
In order to achieve toner fixing at a lower temperature than in the past, instead of the styrene-acrylic resin that has been widely used in the past, an attempt has been made to apply a polyester resin having excellent low-temperature fixability and relatively good heat-resistant storage stability to toner. (JP-A-60-90344, JP-A-64-15755, JP-A-2-82267, JP-A-3-229264, JP-A-3-41470, JP-A-11-305486) Issue gazette). For the purpose of improving low-temperature fixability, an attempt has been made to add a specific non-olefinic crystalline polymer having sharp melt properties at the glass transition temperature to the binder (Japanese Patent Laid-Open No. 62-63940). However, these cannot be said to be optimized with respect to molecular structure and molecular weight. Similarly, attempts have been made to use crystalline polyester having sharp melt properties (Japanese Patent Nos. 2931899 and JP-A-2001-222138). Since the microdomain structure is not disclosed, sufficient low-temperature fixability cannot be obtained.
[0006]
In addition, a toner prepared by a pulverization method using crystalline polyester may lose crystallinity during kneading and generate a component having a low Tg. When a low Tg component is present on the toner surface, the adhesiveness derived from the low Tg component hinders fluidity, and as a result, the toner prepared by the pulverization method using crystalline polyester has a problem in fluidity. Using a crystalline polyester with a micro-domain structure in the toner can exhibit the sharp melt properties of the crystalline polyester, provide sufficient low-temperature fixability, and have sufficient offset resistance. it can. However, a toner using crystalline polyester has insufficient pulverization properties and poor productivity.
[0007]
As a method for improving the pulverization property of the toner, addition of a resin that promotes pulverization is known. For example, Japanese Patent Application Laid-Open No. 4-257868 describes a technique for achieving both pulverization and fixing performance using an aromatic petroleum resin. However, the aromatic petroleum resins used in the above publication are mainly styrene, vinyltoluene, α-methyl of cracked oil fractions by-produced from ethylene plants that produce ethylene, propylene, etc. by petroleum steam cracking. These are oligomers which use as a raw material a fraction which is a mixture of styrene, indene, diisobutylene, toluene, n-octane, xylene, p-ethyltoluene, dicyclopentadiene, β-methylstyrene, and naphthalene. Since the aromatic petroleum resin is generally colored, when such an aromatic petroleum resin is used as a part of the toner component, a resin that is sufficiently satisfactory in terms of color reproducibility and transparency cannot be obtained.
[0008]
Japanese Patent Application Laid-Open No. 11-65161 (corresponding USP No. 5972547) discloses electrostatic image development containing at least a binder resin, a colorant, and a copolymer resin containing at least a styrene monomer and an indene monomer. Toner is described. However, since indene monomers are generally easily colored, the copolymer resin is also easily colored. For this reason, the toner disclosed in the above publication is not fully satisfactory in terms of color reproducibility and transparency. Moreover, when it is going to manufacture the copolymer resin which is not colored, it is necessary to refine | purify an indene-type monomer with very high purity, For this reason, since special equipment is needed for manufacture, there exists a problem in cost.
[0009]
Further, JP-A-11-72956 (corresponding USP No. 59958642) discloses an electrostatic charge containing a colorant, a binder resin and an aliphatic hydrocarbon / aromatic hydrocarbon copolymer petroleum resin having 9 or more carbon atoms. An image developing toner is described. However, although the toner of the above publication can improve the pulverization property, heat storage property, and dispersibility of the release agent, it is still not fully satisfactory in charging performance as a toner.
[0010]
As described above, even if any of these conventionally known techniques is applied, the required properties as a toner are not sufficiently satisfied while achieving energy saving by low-temperature fixing.
[0011]
[Problems to be solved by the invention]
An object of the present invention is to provide an image forming toner used for developing an electrostatic latent image such as an electrophotographic method, an electrostatic recording method, and an electrostatic printing method, and more specifically, sufficient low-temperature fixability. An object of the present invention is to provide an image forming toner for the purpose of establishment. It is another object of the present invention to provide an image forming toner aiming at achieving both energy saving by low-temperature fixing and good pulverization, charging, offset resistance, and fluidity.
It is another object of the present invention to provide a toner container filled with the toner, an image forming method using the toner, and an image forming apparatus loaded with the toner.
[0012]
[Means for Solving the Problems]
The present inventors diligently studied for the purpose of obtaining a toner having both excellent low-temperature fixability and pulverizing properties, charging properties, offset resistance, and fluidity. The present invention has been made based on this.
[0013]
That is, according to the present invention, the following (1) to (16) image forming toner, the following (17) toner container, the following (18) image forming method, and the following (19) image forming apparatus are provided. Provided.
(1) An image-forming toner containing at least two or more types of polyester resins and other resins as a binder resin, wherein at least one type of polyester resin is represented by the following general formula (1). The polyester resin (A) having crystallinity and having the crystallinity, and F higher than the polyester resin (A)_1/2The polyester resin (B) having a temperature has an incompatible phase separation structure, and the other resin (C) is at least one selected from the group consisting of vinyltoluene, α-methylstyrene and isopropenyltoluene. A polymer of seed monomers, or a copolymer of at least one monomer selected from the group consisting of vinyltoluene, α-methylstyrene and isopropenyltoluene, and styrene;The toner has at least three endothermic peaks (i) to (iii) in the endothermic peak measurement by DSC, and the endothermic peak (i) has a peak top in the range of 40 to 70 ° C. The peak (ii) has a peak top in the range of 70 to 90 ° C., the endothermic peak (iii) has a peak top in the range of 90 to 130 ° C., and the dielectric loss tangent of the toner is 2 .5x10 ^-3 ~ 10.0 × 10 ^-3 IsAn image forming toner characterized by the above.
[Chemical 2]
(Wherein R₁, R₂Is a hydrocarbon group. N and m are the number of repeating units. )
(2)
(3)
(4) The toner according to (1) to (3), wherein the toner has a diffraction peak at a position of at least 2θ = 20 to 25 ° in an X-ray diffraction pattern by the powder X-ray diffractometer. The image forming toner according to any one of the above.
(5) The toner for image formation as described in any one of (1) to (4) above, wherein the content of the polyester resin (A) in the binder resin is 1 to 50% by weight.
(6) The alcohol component of the polyester resin (A) is composed of at least one of 1,4-butanediol, 1,6-hexanediol, and derivatives thereof, and the acid component is maleic acid, fumaric acid, succinic acid, And the toner for image formation as described in any one of (1) to (5) above, which comprises at least one of these derivatives.
(7) The glass transition temperature (Tg) of the polyester resin (A) is 90 to 130 ° C., F_1/2The image forming toner according to any one of (1) to (6), wherein the temperature is 80 to 130 ° C.
(8) The glass transition temperature (Tg) of the polyester resin (B) is 40 to 70 ° C., F_1/2The image forming toner according to any one of (1) to (7), wherein the temperature is 120 to 160 ° C.
(9) The image forming toner according to any one of (1) to (8), wherein the polyester resin (A) has an acid value of 20 to 45 mgKOH / g.
(10) The toner for image formation as described in any one of (1) to (9) above, wherein the polyester resin (A) has a hydroxyl value of 5 to 50 mgKOH / g.
(11) GPC molecular weight distribution of soluble content of o-dichlorobenzene of the polyester resin (A), weight average molecular weight (Mw) is 5500-6500, number average molecular weight (Mn) is 1300-1500, Mw / Mn But3.66The image forming toner according to any one of (1) to (10) above, wherein the toner is an image forming toner.
(12) In the X-ray diffraction pattern obtained by the powder X-ray diffractometer, the polyester resin (A) has a diffraction peak at a position of at least 2θ = 19-20 °, 21-22 °, 23-25 °, 29-31 °. The toner for image formation as described in any one of (1) to (11) above, wherein
(13) The image forming toner according to any one of (1) to (12), wherein the acid component of the polyester resin (B) does not have an unsaturated double bond between carbons.
(14) The alcohol component of the polyester resin (B) is at least one of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct, and the acid component is at least terephthalic acid, dodecenyl succinic anhydride, trimellitic anhydride The image forming toner according to any one of (1) to (13), wherein the toner is one.
(15) Any of (1) to (14) above, wherein the toner further contains a release agent, and the glass transition temperature (Tg) of the release agent is 70 to 90 ° C. The image forming toner according to claim 1.
(16) In the above (15), the mold release agent is one or more selected from a liberated fatty acid type carnauba wax, a montan wax and an oxidized rice wax.DescribedImage forming toner.
(17) A toner container filled with the image forming toner according to any one of (1) to (16).
(18) In an image forming method for developing an electrostatic latent image formed on an image carrier, the image forming toner according to any one of (1) to (16) is used as a toner. Forming method.
(19) In the image forming apparatus for developing the electrostatic latent image formed on the image carrier, the image forming toner according to any one of (1) to (16) is loaded as the toner. Image forming apparatus.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in further detail below.
The present inventors diligently studied in order to solve the problems of the present invention, and in the resin constituting the toner, the crystallinity, the molecular weight distribution was sharp, and the absolute amount of the low molecular weight was increased as much as possible. By introducing the aliphatic polyester resin (A) and using the polyester resin (A) in combination with another polyester resin (B), the toner has a microdomain structure to improve the low-temperature fixability of the toner. In addition, by using a resin (C) other than the polyester resin, the pulverization property, charging property and offset resistance of the toner are improved, and the resin (C) is further changed into the polyester resin (A) and the polyester resin (B). The present inventors have found a technical concept that is extremely effective in solving the above-mentioned problem that the toner fluidity can be improved by using in combination. It has been completed.
[0015]
In the present invention, the binder resin of the toner contains at least two kinds of polyester resins and other resins, and the molecular constitution of at least one kind of polyester resin (A) of the polyester resins is changed to an aliphatic low molecular weight. Thus, the polyester resin (A) undergoes a crystal transition at the glass transition temperature (Tg), and at the same time the melt viscosity suddenly decreases from the solid state, thereby providing a fixing function to paper. To express.
Therefore, the glass transition temperature (Tg) and F of the polyester resin (A)_1/2By controlling the temperature, the lower limit fixing temperature can be controlled, and the glass transition temperature (Tg) and F of the polyester resin (A) are within the range where the heat resistant storage stability is not deteriorated, that is, within the range of 80 to 130 ° C._1/2By lowering the temperature, it is possible to obtain low-temperature fixability at a level that could not be obtained conventionally.
[0016]
Furthermore, the polyester resin (A) and a higher molecular weight and higher F than the polyester resin (A)_1/2By making the polyester resin (B) having a temperature incompatible with each other, a high F_1/2It has been found that the presence of the polyester resin (B) having a temperature increases the elasticity of the toner and improves the hot offset resistance. By forming the phase separation structure, different characteristics of each phase, that is, the resin are exhibited, and it becomes possible to secure a low-temperature fixability and a fixing temperature range. When the phase separation structure is not formed, such an effect cannot be obtained.
[0017]
The presence or absence of the formation of the phase separation structure can be confirmed by any of the following methods (1) to (3).
(1) The presence or absence of the formation of a phase separation structure can be confirmed by observing the cross section of the toner with a transmission electron microscope (TEM). The carbon black added as a colorant does not disperse in the polyester resin (A) but is selectively dispersed in the polyester resin (B), so that a portion where no carbon black exists is observed by TEM in an island shape. Can confirm the phase separation structure
[0018]
(2) Whether or not a phase separation structure is formed can be confirmed by measuring the endothermic peak of the toner by DSC. In DSC endothermic peak measurement, there are at least three endothermic peaks (i) to (iii) attributed to the polyester resin (A), the polyester resin (B), and the release agent, and the peak top is in the range of 40 to 70 ° C. The endothermic peak (i) having a peak is attributed to the polyester resin (B), the endothermic peak (ii) having a peak top in the range of 70 to 90 ° C. is attributed to the release agent, and 90 to 130 The endothermic peak (iii) having a peak top in the range of ° C. belongs to the polyester resin (A). FIG. 1 shows a DSC endothermic curve of a toner having a phase separation structure, and FIG. 2 shows a DSC endothermic curve of a toner having no phase separation structure. Thus, when it has a phase separation structure, each of the three components has a separate endothermic peak, and when the phase separation structure is not formed, the three component endothermic peaks overlap.
[0019]
(3) The presence or absence of the formation of a phase separation structure can be confirmed by X-ray diffraction pattern measurement with a powder X-ray diffractometer of toner. This is because the polyester resin (A) exists in a state of being phase-separated from the amorphous polyester resin (B) while maintaining crystallinity, and at least the diffraction peak attributed to the polyester resin (A) is at least. It exists in the position of 2 (theta) = 20-25 degrees. When the phase separation structure is not formed, the crystal structure of the polyester resin (A) is not maintained and is compatible with the amorphous polyester resin (B), so that the diffraction peak attributed to the polyester resin (A) Does not appear.
[0020]
In the toner of the present invention, the formation of a phase separation structure of the polyester resin (A) and the polyester resin (B) is achieved, and the polyester resin (A) and the polyester resin (B) are uniformly dispersed. That is, it is desirable that the micro-domains are uniformly formed and the uniformity is measured by measuring the micro-domain diameters of the polyester resin (A) and the polyester resin (B) in the toner cross section by photographing with TEM. There are two methods of measuring the dielectric loss tangent of toner, which is an index of dispersibility of carbon black used as a colorant. Among these, for the measurement of the dielectric loss tangent of the toner, since carbon black exists only in the polyester resin (B), the measured value of the dielectric loss tangent corresponds to an indicator of the degree of dispersion of the microdomain of the polyester resin (B). And it is a quantitative evaluation method. Therefore, in the present invention, the dispersibility of the polyester resin (A) and the polyester resin (B) is determined by measuring the dielectric loss tangent of the toner.
[0021]
The toner of the present invention has a dielectric loss tangent of 2.5 × 10^-3~ 10.0 × 10^-3In particular, 2.5 × 10^-3~ 7.5 × 10^-3It is preferable that The dielectric loss tangent of the toner is 2.5 × 10^-3~ 7.5 × 10^-3With this range, the dispersion state of the colorant and the like in the toner is uniform and finely dispersed, whereby the charge amount distribution of the toner is controlled within a certain narrow range and excellent. Charge retention and stability are obtained.
The dielectric loss tangent of the toner is 10.0 × 10^-3In the case where it exceeds 1, there is a tendency that the conductivity becomes high, thereby causing poor charging and increasing the background contamination and toner scattering. In addition, since dispersibility of the colorant and the like in the toner is also deteriorated, the toner charge amount distribution becomes non-uniform, and a high-quality image cannot be stably obtained. The dielectric loss tangent of the toner is 2.5 × 10^-3If the ratio is less than 1, the resistance increases and the charge amount increases, and the image density tends to decrease.
[0022]
For the dielectric loss tangent of the toner, first, a toner molded into a pellet shape having a thickness of about 2 mm was set on a solid electrode (SE-70 type manufactured by Ando Electric Co., Ltd.), and an alternating current of 1 kHz was applied between the electrodes. The phase shift at the time was measured with a dielectric loss measuring instrument (TR-10C type manufactured by Ando Electric Co., Ltd.) and calculated by this.
[0023]
After the formation of the phase separation structure of the polyester resin (A) and the polyester resin (B) is achieved, the uniformity of dispersion of the polyester resin (A) and the polyester resin (B) can be adjusted by the kneading conditions. The kneading is desirably performed at a low temperature (minimum temperature in a range where the kneaded material is in a molten state) so that a large kneading share is applied to the kneaded material. When the kneading temperature is too high, not only a uniform dispersion state cannot be obtained, but also the polyester resin (A) and the polyester resin (B) chemically react during melt kneading, and a phase separation structure cannot be obtained. Therefore kneading is F of polyester resin (A) and polyester resin (B)_1/2In consideration of temperature and chemical reactivity (solubility parameter), it is desirable to carry out at the lowest temperature within the range where melt kneading is possible.
[0024]
In the present invention, in the kneading operation at the time of toner production, the melted polyester resin (A) having a low melt viscosity absorbs the resilience at the time of kneading, so that the polyester resin (B) that is easily cut because it has a huge conformation. High F without cutting_1/2Since the temperature and the component amount of the high molecular weight polyester resin (B) can be maintained, the hot offset resistance is improved.
[0025]
Polyester resin (A) molecular structure, molecular weight, glass transition temperature (Tg), F_1/2As a result of intensive studies on the temperature, the molecular structure is not limited, but from the viewpoint of the crystallinity and softening point of the polyester resin, a diol compound having 2 to 6 carbon atoms, particularly 1,4-butanediol, 1,6- The following general formula (1) synthesized using hexanediol, an alcohol component containing these derivatives, and an acid component containing maleic acid, fumaric acid, succinic acid, and these derivatives
[Chemical 3]
[-O-CO-CR₁= CR₂-CO-O- (CH₂)_n-]_m
(Wherein R₁, R₂Is a hydrocarbon group. N and m are the number of repeating units. )
It was found that the aliphatic polyester resin (A) represented by In addition, from the viewpoint of the crystallinity and softening point of the polyester resin, a trihydric or higher polyhydric alcohol such as glycerin is added to the alcohol component in order to synthesize a non-linear polyester, and trimellitic anhydride or the like is added to the acid component. It has been found that polycondensation may be carried out by adding a trivalent or higher polyvalent carboxylic acid.
[0026]
The molecular structure can be confirmed by solid C13-NMR. As for the molecular weight, as a result of intensive studies from the viewpoint that the above-mentioned molecular weight distribution is sharp and the low molecular weight is excellent in low-temperature fixability, the molecular weight distribution by GPC of the soluble part of o-dichlorobenzene is expressed by log (M ), The peak position of the molecular weight distribution chart in which the vertical axis is expressed in weight% is in the range of 3.5 to 4.0, the half width of the peak is 1.5 or less, and the weight average molecular weight (Mw) is 5500 to 6500, number average molecular weight (Mn) is 1300-1500, Mw / Mn is3.66It was found that it is preferably ˜5. Glass transition temperature (Tg) and F_1/2It has been found that the temperature is desirably low so long as the heat resistant storage stability is not deteriorated, and is preferably in the range of 90 to 130 ° C. and in the range of 80 to 130 ° C., respectively.
[0027]
Here, the glass transition temperature (Tg) of the crystalline polyester resin (A) refers to the endothermic peak temperature during the second temperature increase in DSC measurement. F_1/2The temperature refers to the melting temperature in the 1/2 method in the measurement of thermal characteristics using a flow tester. F_1/2The measurement result figure by the flow tester for calculating temperature (melting temperature in 1/2 method) is shown in FIG. In general, the glass transition temperature (Tg) and F_1/2When the temperature is low, the hot offset property and the heat resistant storage property deteriorate, and the glass transition temperature (Tg) and F_1/2If the temperature is high, the lower limit fixing temperature becomes high. Glass transition temperature (Tg) and F_1/2When the temperature is lower than the above range, it is difficult to synthesize a crystalline polyester resin that satisfies the above requirements, and when these temperatures are higher than 130 ° C., the lower limit fixing temperature becomes high, so that low temperature fixability cannot be obtained.
[0028]
The acid value of the polyester resins (A) and (B) is preferably 8 mgKOH / g or more in order to achieve the desired low-temperature fixability from the viewpoint of the affinity between the paper and the resin. 20 mgKOH / g or more is more preferable. On the other hand, in order to improve hot offset resistance, it is preferable that it is 45 mgKOH / g or less. Furthermore, the hydroxyl value of the polyester resins (A) and (B) is preferably from 0 to 50 mgKOH / g, and preferably from 5 to 50 mgKOH / g in order to achieve a predetermined low-temperature fixability and good charging characteristics. Are more preferred.
[0029]
The presence of crystallinity of the polyester resin (A) of the present invention is a diffraction peak at the positions of 2θ = 19-20 °, 21-22 °, 23-25 °, 29-31 ° of the diffraction pattern by the powder X-ray diffractometer. It can be confirmed when appears.
[0030]
In the toner of the present invention, the polyester resin (A) is preferably contained in the binder resin in an amount of 1 to 50% by weight in order to develop low temperature fixability. When the content of the polyester resin (A) is less than 1% by weight, the low-temperature fixability is deteriorated. When the content is more than 50% by weight, the hot offset property is deteriorated and the colorant is not dispersed in the polyester resin (A). For this reason, the dispersibility of the colorant deteriorates, and when carbon black is used as the colorant, there arises a problem that the volume specific resistance of the toner is remarkably lowered.
[0031]
F of polyester resin (B)_1/2For temperature and glass transition temperature (Tg),_1/2It is preferable that the temperature is 120 to 160 ° C and the glass transition temperature (Tg) is 40 to 70 ° C. F_1/2When the temperature is lower than 120 ° C., the resistance to hot offset deteriorates. When the temperature is higher than 160 ° C., a high manufacturing cost is required because a high temperature is required to melt the polyester resin (B) in the melt-kneading step during toner production. And the toner has a high elasticity and therefore has a large share of shear and requires high kneading power, and the pulverization efficiency in the pulverization process is poor and the manufacturing cost is increased. On the other hand, when the glass transition temperature (Tg) is lower than 40 ° C., the heat-resistant storage stability of the toner is remarkably deteriorated and blocking occurs. When the glass transition temperature (Tg) is higher than 70 ° C., the low-temperature fixability of the toner is deteriorated.
[0032]
Here, the glass transition temperature (Tg) of the polyester resin (B) refers to the glass transition temperature (Tg) determined by the tangential method at the second temperature increase in DSC measurement. F_1/2The temperature refers to the melting temperature in the 1/2 method in the measurement of thermal characteristics using a flow tester. F_1/2The measurement result figure by the flow tester for calculating temperature (melting temperature in 1/2 method) is shown in FIG.
[0033]
The molecular structure of the polyester resin (B) is not limited, but in particular, the alcohol component is at least one of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct, and the acid component is terephthalic acid, dodecenyl succinic anhydride. It is desirable that it is at least one of trimellitic anhydride, and it is preferable that the acid component does not have an unsaturated double bond between carbons. When the acid component has an unsaturated double bond between carbons, an unsaturated double bond between carbons of the polyester resin (A) and an unsaturated double bond between carbons of the polyester resin (B) in the melt-kneading step in toner production. The bond may interact with each other to cause plasticization and lose the advantages of the polyester resin (A) and the polyester resin (B). Furthermore, in order to achieve sufficient hot offset resistance, the polyester resin (B) preferably has a gel insoluble in chloroform.
[0034]
The resin (C) used for solving the above-mentioned problems in the present invention is a toner resin containing a polymer of at least one monomer selected from the group consisting of vinyltoluene, α-methylstyrene and isopropenyltoluene. The toner obtained by adding the above resin for toner has excellent charging characteristics. The polymer may be a homopolymer of vinyl toluene, α-methyl styrene or isopropenyl toluene, or a copolymer of these monomers. These polymers are preferably not copolymerized with a monomer other than styrene, but may be copolymerized with a monomer other than styrene as long as the object of the present invention is not impaired.
The polymer used as the toner resin (C) of the present invention may be copolymerized with styrene. The content of styrene is 50 mol% or less, preferably 40 to 20 mol%, as a proportion of styrene in all monomers constituting the copolymer.
[0035]
When the resin (C) is used in combination with the polyester resin (A), the resin is particularly at the time of pulverization because of the relationship between insufficient pulverization due to the crystallinity of the polyester resin (A) and brittleness of the resin (C). (C) tends to be present at the grinding interface. The resin (C) is excellent in chargeability and fluidity due to its molecular structure, and the chargeability and fluidity of the toner obtained by the presence of the resin (C) on the toner surface are improved. Therefore, when the resin (C) and the polyester resin (A) are used in combination, the effect of improving the chargeability and fluidity of the finally obtained toner is particularly great.
[0036]
As the release agent used for the toner in the present invention, all known ones can be used, and in particular, de-free fatty acid type carnauba wax, montan wax and oxidized rice wax can be used alone or in combination.
As the carnauba wax, fine crystallites having an acid value of 5 or less and a particle diameter of 1 μm or less when dispersed in the toner binder resin are preferable, but not limited thereto.
The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is preferably microcrystalline and has an acid value of 5 to 14, but not limited thereto.
The oxidized rice wax is obtained by oxidizing rice bran wax with air, and the acid value is preferably 10 to 30, but not limited thereto.
As other mold release agents, any conventionally known mold release agents such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, and low molecular weight polypropylene wax can be mixed and used.
[0037]
The glass transition temperature (Tg) of the release agent is preferably 70 to 90 ° C. When the temperature is lower than 70 ° C., the heat resistant storage stability of the toner is deteriorated, and when it is higher than 90 ° C., the release property at low temperature is exhibited. First, deterioration of hot offset resistance and winding of paper around the fixing machine occur.
Here, the glass transition temperature (Tg) of the release agent refers to the endothermic peak temperature at the second temperature increase in DSC measurement.
The amount of these release agents used is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the toner resin component.
[0038]
The particle size of the toner of the present invention is not particularly limited, but in order to obtain a high image quality excellent in fine line reproducibility and the like, the volume average particle size is preferably 5 to 10 μm.
Here, the volume average particle diameter of the toner can be measured by various methods. In the present invention, Coulter Counter TAII manufactured by Coulter Electronics, USA is used.
[0039]
Below, the measuring method of other each physical property etc. is demonstrated.
For solid C13-NMR, FT-NMR SYSTEM JNM-α400 manufactured by JEOL Ltd. was used, observation nucleus C13, reference material adamantane, integration number 8192 times, pulse series CPMAS. IRMOD: IRLEV, observation frequency 100.4 MHz, OBSET: 134500 Hz, POINT: 4096, PD: 7.0 sec, SPIN 6088 Hz, and molecular structure estimation is performed by Chem Draw Pro Ver. 4.5 was used.
[0040]
To observe the toner cross section, Hitachi Transmission Electron Microscope H-9000 was used, and the toner particles were cut into ultra-thin sections of about 100 μm under the condition of an acceleration voltage of 300 kV, stained with ruthenium tetroxide, and then analyzed with a transmission electron microscope (TEM). Observation was performed at a magnification of 10,000 times, and a photograph was taken.
[0041]
GPC (gel permeation chromatography) is measured as follows.
The column was stabilized in a heat chamber at 145 ° C., and o-dichlorobenzene containing 0.3% BHT as an eluent was allowed to flow through the column at this temperature at a flow rate of 1 ml / min to a sample concentration of 0.3% by weight. Measurement is performed by injecting 50 to 200 μl of 140 ° C. o-dichlorobenzene solution of the prepared resin. Waters 150CV type can be used as a measuring instrument, and Shodex AT-G + AT-806MS (two) can be used as a column. In the measurement of the molecular weight of the sample (toner), the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. The slice width is 0.05 seconds. As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. Or the molecular weight made by Toyo Soda Industry Co., Ltd. is 6 × 10²2.1 × 10³4 × 10³1.75 × 10⁴5.1 × 10⁴1.1 × 10⁵3.9 × 10⁵8.6 × 10⁵2 × 10⁶4.48 × 10⁶It is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.
[0042]
F of binder resin_1/2The temperature is an elevated flow tester CFT-500 (manufactured by Shimadzu Corporation), with a die diameter of 1 mm and a pressure of 10 kg / cm.²1 cm under the condition of a heating rate of 3 ° C./min²Measured at a temperature corresponding to ½ from the outflow start point to the outflow end point when the sample was melted out.
[0043]
The Tg of the resin is measured with a Rigaku THRMOFLEX TG8110 manufactured by Rigaku Corporation at a temperature increase rate of 10 ° C./min.
[0044]
The acid value and hydroxyl value of the resin are measured by the method specified in JIS K0070. However, when the sample does not dissolve, a solvent such as dioxane or THF, o-dichlorobenzene is used as the solvent.
[0045]
The powder X-ray diffraction measurement is performed by using Rigaku Denki RINT1100, using a wide-angle goniometer under the conditions that the tube is Cu and the tube voltage-current is 50 kV-30 mA.
[0046]
In the present invention, the production method of the toner is not limited, and may be a normal pulverization method, a production method other than the pulverization method such as a polymerization method, or a combination thereof.
[0047]
Next, materials used for the toner of the present invention will be described in detail.
The polyester resin used in the present invention is usually obtained by condensation polymerization of an alcohol component and a carboxylic acid component.
Examples of the alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and the like, glycols such as 1,4-butanediol and 1,6-hexanediol, 1,4-bis (hydroxymethyl) cyclohexane, and Examples thereof include etherified bisphenols such as bisphenol A ethylene oxide adduct and bisphenol A propion oxide adduct, other divalent alcohol monomers, and trivalent or higher polyhydric alcohol monomers.
[0048]
Examples of the carboxylic acid component include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, malonic acid, dodecenyl succinic anhydride, and the like. -Benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, Examples thereof include trivalent or higher polyvalent carboxylic acid monomers such as 1,3-dicarboxyl-2-methylenecarboxypropane and 1,2,7,8-octanetetracarboxylic acid.
[0049]
Resin (C) used in the present invention is a resin made of a polymer of at least one monomer selected from the group consisting of vinyltoluene, α-methylstyrene and isopropenyltoluene, or a copolymer obtained by copolymerizing styrene. Can be obtained by polymerizing the monomer in the presence of a catalyst. Examples of the catalyst used for polymerization include those generally known as Friedel-Crafts catalysts, such as aluminum chloride, aluminum bromide, dichloromonoethylaluminum, titanium tetrachloride, tin tetrachloride, boron trifluoride and the like. And the like. The catalyst is used in an amount of 0.01 to 5% by weight, preferably 0.05 to 3% by weight, based on the total amount of monomers.
[0050]
Further, at the time of the polymerization reaction, at least one selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons and alicyclic hydrocarbons for the purpose of removing reaction heat and suppressing the increase in viscosity of the reaction mixture. The polymerization reaction is preferably carried out in a hydrocarbon solvent. Preferred hydrocarbon solvents include aromatic hydrocarbons such as toluene, xylene, ethylbenzene, mesitylene, cumene, and cymene, or mixtures thereof; or aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and / or cyclopentane. And mixtures with alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. The amount of these reaction solvents used is preferably such that the initial monomer concentration in the reaction mixture is 10 to 80% by weight.
[0051]
The polymerization temperature can be appropriately selected depending on the type and amount of the monomer and catalyst used, but it is usually preferably −30 to + 50 ° C. The polymerization time is generally about 0.5 to 5 hours, and the polymerization is usually almost completed within 1 to 2 hours. As the polymerization mode, either a batch system or a continuous system can be adopted. Multistage polymerization can also be performed.
[0052]
After completion of the polymerization, it is preferable to remove the catalyst by washing. As the cleaning solution, it is preferable to use an alkaline aqueous solution in which potassium hydroxide, sodium hydroxide or the like is dissolved; alcohol such as methanol or the like, and cleaning deashing with methanol is particularly preferable. After completion of the washing, unreacted monomers, polymerization solvent and the like are distilled off under reduced pressure to obtain a polymer or copolymer used in the present invention.
[0053]
The resin (C) used in the present invention is an electrostatic charge image developing toner resin. The amount of the toner resin used is 1 to 20 parts by weight, preferably 3 to 15 parts by weight, per 100 parts by weight of the binder resin. Since the amount used is in the range of 1 to 20 parts by weight, a toner excellent in pulverization property is obtained and is not excessively pulverized. Therefore, the toner particle size does not change greatly in the developing machine.
[0054]
In the present invention, as described above, it is most suitable to use the polyester resins (A), (B) and the resin (C) as the resin component in the toner. However, resins other than these resins may also be used. If the molecular weight distribution is satisfied, low-temperature fixing can be achieved by using other resins in combination as long as the performance of the toner is not impaired.
[0055]
Examples of resins that can be used in combination include the following. These resins are not limited to single use, and two or more types can be used in combination.
Polystyrene, chloropolystyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / maleic acid copolymer Styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / acrylic acid) Phenyl copolymer, etc.), styrene / methacrylate copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / phenyl methacrylate copolymer) Coalesce etc.), styrene / α-chlorac Styrenic resins (homopolymers or copolymers containing styrene or styrene-substituted products) such as methyl oxalate copolymer, styrene / acrylonitrile / acrylate ester copolymer, vinyl chloride resin, styrene / vinyl acetate copolymer , Rosin-modified maleic resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc. , Hydrogenated petroleum resin.
[0056]
The method for producing these resins is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.
In addition, the glass transition temperature Tg of the resin is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of heat storage stability.
[0057]
Examples of the colorant used in the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, Any conventionally known dyes such as rose bengal and triallylmethane dyes can be used alone or in combination, and can be used as a black toner or a full color toner. The amount of these colorants to be used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.
[0058]
The toner of the present invention can be blended with a charge control agent, a fluidity improving agent, and the like as required.
As the charge control agent, any conventionally known charge control agents such as nigrosine dyes, metal complex dyes, quaternary ammonium salts and the like can be used alone or in combination.
In particular, a salicylic acid metal complex, preferably a complex having a trivalent or higher metal capable of taking a 6-coordinate structure, is preferable for the above-described reason. Here, examples of the trivalent or higher metal include Al, Fe, Cr, and Zr. The amount of these charge control agents used is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the toner resin component.
[0059]
As the fluidity improver, any conventionally known fluidity improver such as hydrophobic silica, titanium oxide, silicon carbide, aluminum oxide, barium titanate can be used alone or in combination. Titanium is excellent in terms of improving fluidity, stabilizing charging, and stabilizing image quality. More preferably, when hydrophobic silica and titanium oxide are used in combination, a good toner with stable fluidity and chargeability can be obtained.
The amount of these fluidity improvers used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the toner.
[0060]
Further, the toner of the present invention can be used as a magnetic toner containing a magnetic material. Examples of magnetic materials contained in the toner include iron oxides such as magnetite, hematite, and ferrite, metals such as iron, cobalt, and nickel, and these. Metal alloys such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof. Magnetite is particularly preferable from the viewpoint of magnetic properties.
These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 μm. The amount of the ferromagnetic material to be contained in the toner is about 15 to 200 parts by weight, particularly preferably 100 parts by weight of the resin component, with respect to 100 parts by weight of the resin component. 20 to 100 parts by weight per part.
[0061]
The toner of the present invention can be used as a one-component developer or a two-component developer combined with a carrier.
[0062]
As the carrier in the case where the toner of the present invention is used as a two-component developer, all known ones can be used, for example, magnetic powder such as iron powder, ferrite powder, nickel powder, glass beads, and the like. The thing which processed these surfaces with resin etc. is mentioned.
Examples of the resin powder that can be coated on the carrier in the present invention include a styrene / acrylic copolymer, a silicone resin, a maleic acid resin, a fluorine resin, and a polyester resin epoxy resin. In the case of a styrene / acrylic copolymer, those having a styrene content of 30 to 90% by weight are preferred. In this case, when the styrene content is less than 30% by weight, the development characteristics are low, and when it exceeds 90% by weight, the coating film becomes hard and easily peeled, and the life of the carrier is shortened.
Moreover, the resin coating of the carrier in the present invention may contain an adhesion-imparting agent, a curing agent, a lubricant, a conductive material, a charge control agent and the like in addition to the resin.
[0063]
When the toner of the present invention is used as a one-component developer or a two-component developer, the toner is filled in a container, and the container filled with the toner is distributed separately from the image forming apparatus, and the user can It is common to form an image by mounting on a forming apparatus.
What is used as the container is not limited, and is not limited to the conventional bottle type or cartridge type.
[0064]
The image forming apparatus of the present invention is not limited as long as it is an apparatus for forming an image by electrophotography, and includes, for example, a copying machine and a printer.
Embodiments of an image forming method and apparatus according to the present invention will be described below.
FIG. 4 is a schematic configuration diagram showing an example of an image forming method and apparatus according to the present invention. In FIG. 4, the photoreceptor 1 as an image carrier is rotated in the direction of the arrow (counterclockwise) in the figure and is uniformly charged by the charging roller 2. Thereafter, the image is exposed by exposure of an original image from an exposure unit (not shown) or optical writing by a laser beam from an optical writing device (not shown), and an electrostatic latent image is formed on the photoreceptor 1. A developer 4 is contained in the developing device 3. As the developer 4, a two-component developer that is a mixture of a carrier and a toner is used. When the developer 4 is stirred, the toner is charged by frictional charging. A developing sleeve 5 having a plurality of magnets or a magnet roller having a plurality of magnetic poles disposed therein is disposed at a position facing the photoreceptor 1 of the developing device 3, and the developer 4 is developed by a magnetic force. The electrostatic latent image on the photosensitive member 1 is developed with toner.
[0065]
A transfer belt 6 is disposed on the downstream side of the developing device 3 in the rotation direction of the photosensitive member 1, and this transfer belt 6 is stretched around a driving roller and a driven roller and rotated in the direction of the arrow in the figure. . Further, the transfer belt 6 is provided so as to be able to come into contact with and separate from the photoreceptor 1 by a contact / separation mechanism (not shown), and contacts the photoreceptor 1 during transfer to form a nip portion and transport the transfer paper S. Further, a voltage (transfer output) having a polarity opposite to that of the toner is applied to the back side of the transfer belt 6 by a power source (not shown) via a bias roller 6a.
[0066]
The transfer sheet S transported from a sheet feeding unit (not shown) is fed to the nip portion between the photoreceptor 1 and the transfer belt 6 by the registration roller 18 in accordance with the timing of image formation on the photoreceptor 1 and developed on the photoreceptor 1. The toner image thus transferred is transferred onto a transfer sheet S sandwiched between the photoreceptor 1 and the transfer belt 6 by the electric field between the transfer belt 6 and the photoreceptor 1. The transfer sheet S to which the toner image is transferred is then conveyed by the transfer belt 6 and passes through a fixing device (not shown). At this time, the toner image is thermally welded onto the transfer sheet. Then, the fixed transfer sheet S is discharged to a paper discharge section (not shown). On the other hand, the toner remaining on the photosensitive member without being completely transferred is blocked by the cleaning blade 7 and is put on the recovery coil 9 by the recovery spring 8. The recovery coil 9 returns the toner to the developing device 3 as recycled toner. The cleaned photoreceptor 1 is neutralized by a neutralizing lamp 20.
[0067]
【Example】
Hereinafter, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. All parts are parts by weight.
[0068]
<Toner Production Example 1>
27 parts of polyester resin A1
63 parts of polyester resin B1
Resin C1 10 parts
De-free fatty acid type carnauba wax (Tg: 83 ° C) 5 parts
Carbon black (Mitsubishi Chemical # 44) 10 parts
[0069]
The above toner constituent materials were sufficiently stirred and mixed in a Henschel mixer, then kneaded in a twin screw extruder, cooled, pulverized and classified to obtain a base toner having a volume average diameter of 6.8 μm. Regarding the kneading conditions, as a result of setting the temperature of the kneader to knead the kneaded material at a low temperature (minimum temperature within the range where the kneaded material is in a molten state), the kneading material is mixed at the kneader outlet. The temperature of the kneader was set so that the temperature of the smelted product was 120 ° C. To the toner base obtained as a fluidity improver, 0.5% by weight of hydrophobic silica and 0.3% by weight of titanium oxide were added and mixed to obtain a final toner.
[0070]
<Toner Production Example 2>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A2 in Toner Production Example 1.
[0071]
<Toner Production Example 3>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A3 in Toner Production Example 1.
[0072]
<Toner Production Example 4>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A4 in Toner Production Example 1.
[0073]
<Toner Production Example 5>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A5 in Toner Production Example 1.
[0074]
<Toner Production Example 6>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A6 in Toner Production Example 1.
[0075]
<Toner Production Example 7>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin A1 was changed to the polyester resin A7 in Toner Production Example 1.
[0076]
<Toner Production Example 8>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin B1 was changed to the polyester resin B2 in Toner Production Example 1.
[0077]
<Toner Production Example 9>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin B1 was changed to the polyester resin B3 in Toner Production Example 1.
[0078]
<Toner Production Example 10>
A toner was prepared in the same manner as in Toner Production Example 1 except that the polyester resin B1 was changed to the polyester resin B4 in Toner Production Example 1.
[0079]
<Toner Production Example 11>
A toner was prepared in the same manner as in Toner Production Example 1 except that Resin C1 was changed to Resin C2 in Toner Production Example 1.
[0080]
<Toner Production Example 12>
A toner was prepared in the same manner as in Toner Production Example 1 except that the formulation was changed to the following.
30 parts of polyester resin A1
70 parts of polyester resin B1
De-free fatty acid type carnauba wax (Tg: 83 ° C) 5 parts
Carbon black (Mitsubishi Chemical # 44) 10 parts
[0081]
<Toner Production Example 13>
A toner was obtained in the same manner as in Toner Production Example 1 except that the de-free fatty acid type carnauba wax in Toner Production Example 1 was changed to polyethylene wax (Tg 58 ° C.).
[0082]
<Toner Production Example 14>
A toner was obtained in the same manner as in Toner Production Example 1 except that the defree fatty acid type carnauba wax in Toner Production Example 1 was changed to polyethylene wax (Tg 110 ° C.).
[0083]
<Toner Production Example 15>
A toner was prepared in the same manner as in Toner Production Example 1 except that the temperature of the kneader was set so that the temperature of the kneaded product at the kneader outlet was 200 ° C. in Toner Production Example 1.
[0084]
<Toner Production Example 16>
A toner was prepared in the same manner as in Toner Production Example 1 except that the formulation was changed to the following.
54 parts of polyester resin A1
36 parts of polyester resin B1
Resin C1 10 parts
De-free fatty acid type carnauba wax (Tg: 83 ° C) 5 parts
Carbon black (Mitsubishi Chemical # 44) 10 parts
[0085]
<Toner Production Example 17>
A toner was prepared in the same manner as in Toner Production Example 1 except that the formulation was changed to the following.
0.5 part of polyester resin A1
Polyester resin B1 89.5 parts
Resin C1 10 parts
De-free fatty acid type carnauba wax (Tg83 ℃) 5 parts
Carbon black (Mitsubishi Chemical # 44) 10 parts
[0086]
Tables 1, 2 and 3 show the physical properties of the polyester resins (A) and (B) and the resin (C) used in the toner production examples.
[Table 1]
[0087]
In addition, a thing with crystallinity has a diffraction peak in the position of at least 2 (theta) = 19-20 degrees, 21-22 degrees, 23-25 degrees, 29-31 degrees in the X-ray-diffraction pattern by a powder X-ray-diffraction apparatus. Appearing and having an estimated molecular formula means that the existence of the molecular structure of the general formula (1) was confirmed by solid-state C13 NMR.
[0088]
[Table 2]
[0089]
[Table 3]
[0090]
<Example of carrier production>
[0091]
The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and the coating solution and core material are applied to a coating apparatus in which a rotating bottom plate disk and a stirring blade are provided in a fluidized bed to perform a coating while forming a swirling flow. And the coating solution was applied onto the core material.
Further, the obtained carrier was baked in an electric furnace at 250 ° C. for 2 hours to obtain carrier particles (saturation magnetization 65 emu / g when 3 kOe was applied, residual magnetization 0 emu / g when 3 kOe was applied, specific resistance 3.2 × 10⁸Ω · cm, volume average diameter 45 μm).
[0092]
<Examples of developer production>
2.5 parts of each of the toners of Production Examples 1 to 11 and 97.5 parts of the carrier of the Production Examples were mixed with a tumbler mixer to obtain developers of Examples and Comparative Examples.
[0093]
[Examples and Comparative Examples]
A method for evaluating the characteristics of the toner prepared in each of the examples and comparative examples will be described.
1) Fixability evaluation
Ricoh Co., Ltd. Copier MF2200 fixing unit (using a Teflon roller as a fixing roller) was remodeled, and type 6200 paper manufactured by Ricoh Co., Ltd. was set in this, and a copying test was performed.
The cold offset temperature (fixing lower limit temperature) and the hot offset temperature (hot offset resistant temperature) were determined by changing the fixing temperature. The minimum fixing temperature of the conventional low-temperature fixing toner is about 140 to 150 ° C. The evaluation conditions for low-temperature fixing are as follows: the linear speed of paper feed is 120 to 150 mm / sec, and the surface pressure is 1.2 kgf / cm.²The evaluation conditions for the nip width of 3 mm and the high temperature offset are as follows: the linear velocity of paper feed is 50 mm / sec, and the surface pressure is 2.0 kgf / cm.²The nip width was set to 4.5 mm.
The criteria for each characteristic evaluation are as follows.
(1) Low-temperature fixability (5-level evaluation)
A: Less than 130 ° C., ○: 130 ° C. to less than 140 ° C., □: 140 to less than 150 ° C., Δ: 150 to less than 160 ° C., X: 160 ° C. or more
▲ 2 ▼ Hot offset property (5-level evaluation)
A: higher than 200 ° C, B: higher than 200-191 ° C, □: higher than 190-180 ° C, Δ: higher than 180-170 ° C, x: 170 ° C or lower
[0094]
2) Dirt evaluation
A developer was set in MF-2200 manufactured by Ricoh Co., Ltd., and 100,000 copies were continuously copied in a normal temperature / humidity environment, and the degree of occurrence of scumming in the non-image area was visually evaluated.
◎: very good level, ○: good level, □: general level, △: practically no problem level, ×: practically problematic level
[0095]
3) Evaluation of heat storage stability
A glass container is filled with toner and left in a thermostatic bath at 50 ° C. for 24 hours. The toner is cooled to 24 ° C., and the penetration is measured by a penetration test (JIS K2235-1991). A toner having a larger value has better storage stability against heat. When this value is 5 mm or less, there is a high possibility of problems in use.
Judgment criteria for thermal storage stability based on the penetration is as follows.
Penetration, ○: 25 mm or more, □: 20 mm to less than 25 mm, Δ: 15 mm to less than 20 mm, x: less than 15 mm
[0096]
4) Evaluation of toner dispersion state
The toner particles were cut into ultra-thin sections of about 100 μm, dyed with ruthenium tetroxide, and then observed with a transmission electron microscope (TEM) at a magnification of about 10,000 to take a photograph. Image evaluation of this photograph confirmed the presence or absence of a discontinuous phase between the polyester resin (A) and the polyester resin (B) in the toner.
[0097]
5) Evaluation of grindability
The ease of grinding was determined from the amount of processing per unit time when the kneaded product that had been crushed to an average particle size of 1 mm or less was pulverized by an IDS type pulverizer manufactured by Nippon Pneumatic. The larger the processing amount per unit time, the easier the pulverization and the better the toner productivity.
The criteria for determining the ease of grinding based on the throughput per unit time are as follows.
A: 2.0 kg / h or more, B: 1.5 kg / h to less than 2.0 kg / h, D: 1.0 kg / h to less than 1.5 kg / h, Δ: 0.5 kg / h to 1.0 kg </ H, x: <0.5 kg / h
[0098]
6) Dissipation factor
About 2 mm thick toner molded into a pellet is set on an SE-70 type solid electrode manufactured by Ando Electric Co., Ltd., and the phase shift when an AC voltage of 1 kHz is applied between the electrodes is Ando Electric Co., Ltd. The dielectric loss tangent was obtained by measuring with a TR-10C type dielectric loss measuring instrument manufactured by the company.
[0099]
7) Evaluation of chargeability
After 6 g of developer was stirred for 10 minutes at a rotational speed of 250 rpm with a mag roller, the toner and the carrier were frictionally charged, and the charge amount of the toner was measured with a Faraday cage. The evaluation criteria for chargeability are as follows.
A: −10.0 μC / g or less, B: −7.5 μC / g to less than −10.0 μC / g, D: −5.0 μC / g to less than −7.5 μC / g, Δ: −2 .5 μC / g to less than −5.0 μC / g, x: less than −2.5 μC / g
[0100]
8) Evaluation of fluidity
Low index of aggregation was used as an index for evaluating fluidity. For the measurement of the degree of aggregation, a powder tester (PT-N type manufactured by Hosokawa Micron Corporation) was used, and sieves with openings of 149 μm, 74 μm and 44 μm were used. Three sieves were stacked with the coarser screen up, the toner was sieved and the ratio of the total amount of toner remaining on the sieve was defined as the degree of aggregation. The lower the degree of aggregation, the better the fluidity. The amount of toner used for the measurement of the degree of aggregation was 2.0 g, the vibration time of the sieve was 30 seconds, and the amplitude was 1 mm. The evaluation criteria for liquidity are as follows.
◎: Less than 35%, ○: 35% to less than 50%, □: 50% to less than 65%, Δ: 65% to less than 80%, ×: 80% or more
[0101]
[0102]
In Table 4, “having a toner phase separation structure” means that the phase separation structure was confirmed by TEM observation of the cross section of the toner. The toner endothermic peak has at least three endothermic peaks (i) to (iii) in DSC measurement, the endothermic peak (i) has a peak top in the range of 40 to 70 ° C., and the endotherm. It was confirmed that the peak (ii) has a peak top in the range of 70 to 90 ° C. and the endothermic peak (iii) has a peak top in the range of 90 to 130 ° C. Those having crystallinity are those in which the presence of a diffraction peak is confirmed at least at a position of 2θ = 20 to 25 ° in an X-ray diffraction pattern by a powder X-ray diffractometer.
[0103]
【The invention's effect】
According to the present invention, a toner for image formation having a wide fixing temperature range, which satisfies both low temperature fixing property and hot offset resistance without impairing charging property, productivity (smoothness) and fluidity, is filled with the toner. The toner container, the image forming method using the toner, and the image forming apparatus loaded with the toner can be provided.
[Brief description of the drawings]
FIG. 1 is a DSC curve of a toner forming a phase separation structure.
FIG. 2 is a DSC curve of a toner that does not form a phase separation structure.
FIG. 3 F_1/2It is a measurement result figure by the flow tester for calculating temperature.
FIG. 4 is a schematic configuration diagram illustrating an example of an image forming method and apparatus according to the present invention.
[Explanation of symbols]
1 Photoconductor (image carrier)
2 Charging roller
3 Development device
4 Developer
5 Development sleeve (developer carrier)
6 Transfer belt (transfer means)
6a Bias roller
7 Cleaning blade
8 Collection spring
9 Collection coil
10 Photoreceptor and cleaning unit (PCU)
13 Conveying screw
14 Paddle (stirring mechanism)
16 Reflection density detection sensor (P sensor)
17 Toner density sensor
18 Registration Roller
20 Static elimination lamp
S transfer paper

Claims (17)

A toner for image formation containing at least two kinds of polyester resins and other resins as a binder resin, wherein at least one kind of polyester resin is represented by the following general formula (1) and has crystallinity: The polyester resin (A) having crystallinity and the polyester resin (B) having an F1 _{/ 2} temperature higher than that of the polyester resin (A) have a phase separation structure incompatible with each other. The other resin (C) is a polymer of at least one monomer selected from the group consisting of vinyltoluene, α-methylstyrene and isopropenyltoluene, or vinyltoluene, α-methylstyrene and isopropenyltoluene. comprising at least one monomer selected from the group, a copolymer of styrene, the bets In the endothermic peak measurement by DSC has at least three endothermic peaks (i) to (iii), the endothermic peak (i) has a peak top in the range of 40 to 70 ° C., and the endothermic peak. (Ii) has a peak top in the range of 70 to 90 ° C., and endothermic peak (iii) has a peak top in the range of 90 to 130 ° C., and the dielectric loss tangent of the toner is 2. An image forming toner, wherein the toner is 5 × 10 ^{−3 to} 10.0 × 10 ⁻³ .
(Wherein R ₁ and R ₂ are hydrocarbon groups, and n and m are the number of repeating units.) 2. The image forming toner according to claim 1, wherein the toner has a diffraction peak at a position of at least 2θ = 20 to 25 ° in an X-ray diffraction pattern by the powder X-ray diffractometer. The image forming toner according to claim 1, wherein the content of the polyester resin (A) in the binder resin is 1 to 50% by weight. The alcohol component of the polyester resin (A) is composed of at least one of 1,4-butanediol, 1,6-hexanediol, and derivatives thereof, and the acid component is maleic acid, fumaric acid, succinic acid, and these The image forming toner according to claim 1, comprising at least one of derivatives. The polyester resin (A) has a glass transition temperature (Tg) of 90 to 130 ° C., F _1/2 The image forming toner according to claim 1, wherein the temperature is 80 to 130 ° C. The polyester resin (B) has a glass transition temperature (Tg) of 40 to 70 ° C., F _1/2 The image forming toner according to claim 1, wherein the toner has a temperature of 120 to 160 ° C. The image forming toner according to claim 1, wherein the acid value of the polyester resin (A) is 20 to 45 mg KOH / g. The image forming toner according to claim 1, wherein the polyester resin (A) has a hydroxyl value of 5 to 50 mg KOH / g. The weight average molecular weight (Mw) is 5500-6500 and the number average molecular weight (Mn) is 1300 by molecular weight distribution by GPC of the soluble part of the polyester resin (A) o-dichlorobenzene. The toner for image formation according to any one of claims 1 to 8, wherein 1500 and Mw / Mn are 3.66 to 5. The polyester resin (A) has a diffraction peak at a position of at least 2θ = 19 to 20 °, 21 to 22 °, 23 to 25 °, and 29 to 31 ° in an X-ray diffraction pattern by the powder X-ray diffractometer. The image forming toner according to claim 1, wherein the toner is an image forming toner. The toner for image formation according to claim 1, wherein the acid component of the polyester resin (B) does not have an unsaturated double bond between carbons. The alcohol component of the polyester resin (B) is at least one of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct, and the acid component is at least one of terephthalic acid, dodecenyl succinic anhydride, and trimellitic anhydride. The toner for image formation according to claim 1, wherein the toner is for image formation. The image formation according to claim 1, wherein the toner further contains a release agent, and the glass transition temperature (Tg) of the release agent is 70 to 90 ° C. Toner. The image forming toner according to claim 13, wherein the releasing agent is one or more selected from a liberated fatty acid type carnauba wax, a montan wax, and an oxidized rice wax. A toner container filled with the image forming toner according to claim 1. An image forming method for developing an electrostatic latent image formed on an image carrier, wherein the image forming toner according to claim 1 is used as the toner. 15. An image forming apparatus for developing an electrostatic latent image formed on an image carrier, wherein the image forming toner according to claim 1 is loaded as toner.