JP2002214833A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which ensures a sufficient fixing temperature range and is superior in hot storage resistance because a wax is dispersed in the optimum state in a resin excellent in low temperature fixability, produces little adverse effects due to the contained wax and has high productivity. SOLUTION: The toner contains at least two or more resins and a wax incompatible with one another and having a sea-island phase separated structure, in which a resin B is dispersed island-like in a sea-like resin A forming a continuous phase and the wax is included in the island-like resin B. 1 The resin A is chiefly a polyester and/or a polyol and contains a THF-insoluble component. 2 The resin B contains no THF-insoluble component, the temperature of the highest peak which appears on the endothermic side of the DSC(differential scanning calorie) curve of the resin B, measured with a differential scanning calorimeter, is 62-90 deg.C and the weight average molecular weight Mw of a THF- soluble component by GPC(gel permeation chromatography) satisfies the equality Mw=-300×T+32,000 (where T is the temperature ( deg.C) of the highest peak, which appears on the endothermic side of the DSC curve).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner which uses a plurality of resins having a phase separation structure, has a wide fixing temperature range, and has excellent storage stability and productivity.

[0002]

2. Description of the Related Art In recent years, energy conservation has been increasing due to environmental considerations, and low-temperature fixing type toners capable of fixing with low energy have been actively developed. In response to this, attempts have been made to use polyester resins that have excellent low-temperature fixability and relatively good heat-resistant storage stability, instead of styrene-acrylic resins that have been frequently used.

However, in order to further lower the fixing temperature,
It is necessary to control the thermal characteristics of the resin itself, and there are problems such as lowering the glass transition temperature, which deteriorates the heat-resistant storage stability, and lowering the molecular weight and softening the resin lowers the hot offset occurrence temperature. .

Conventionally, a method of applying a release oil to a fixing roller has been adopted for the occurrence of offset.
However, from the viewpoint of space saving, in many cases, instead of an oil applying method in which an oil tank is mounted, a toner or the like instead of a release oil such as wax is contained in the toner. The wax in the toner exudes from the toner at the time of fixing to exhibit releasability. For this purpose, the wax needs to exist as a domain having a certain size in the toner.

However, when the toner is pulverized, stress concentrates on the interface between the resin and the wax, and the wax tends to exist on the particle surface. Therefore, as the wax dispersion diameter increases, the amount of the wax present on the particle surface tends to increase. Although this is an advantageous direction from the viewpoint of the property, there is a problem that the fluidity of the toner is deteriorated and that it is difficult to obtain a good image by fusing to a carrier or other charging member.

[0006] Unless the conventional low-temperature fixability is taken into consideration, the wax is easily finely dispersed by the shearing force at the time of kneading the resin, and the problem caused by the inclusion of the wax is small. Further, even if the wax is finely dispersed and the exudation is insufficient, the releasability is easily secured because the cohesive force of the resin itself is large. However, in a resin considering low-temperature fixability, since the shearing force at the time of kneading is small, the wax is hardly finely dispersed, and problems such as deterioration of durability and transferability due to inclusion of the wax become remarkable. On the other hand, the polyester resin and the polyol resin have a disadvantage that productivity is remarkably reduced in the toner pulverization step because the resin itself has high strength.

Japanese Patent Application Laid-Open No. 7-84407 discloses an example of a toner containing a wax formed by a polymerization method. However, the toner is not a toner produced through a melting step and a pulverizing step. In JP-A-6-250432 and JP-A-9-127718, a wax dispersant is contained in the toner, but the wax dispersion diameter is too small, and the presence of wax near the particle surface of the toner exists. The ratio becomes low, and the effect as the release agent cannot be sufficiently obtained.

Japanese Patent Application Laid-Open No. Hei 11-052616 proposes a toner containing 70% by weight or more of a petroleum resin and having both heat-resistant storage stability and low-temperature fixability and excellent pulverizability. The hot offset property was insufficient, the toner was liable to be excessively pulverized, and a large amount of fine powder was generated, and the toner particle diameter was easily reduced even in a developing machine, leading to a decrease in developability. Further, JP-A-11-072956
The publication states that a specific petroleum resin is contained to improve the balance of compatibility with a binder resin and wax, and to improve the offset resistance, crushability, and filming property while maintaining low-temperature fixability. A toner is described. However, if the binder resin, the petroleum resin, and the wax are too compatible, the incompatible interface disappears, and the pulverizability may be reduced.
Other than petroleum resin, there is a resin having a similar effect.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and has an optimum dispersion of a wax in a resin excellent in low-temperature fixability to ensure a sufficient fixing temperature range, and a heat-resistant storage stability. It is an object of the present invention to provide a toner which is excellent in toner performance, has few side effects due to wax content, and has high productivity.

[0010]

The above object of the present invention is achieved by the following means. That is, according to the present invention,
Claim 1 contains at least two or more types of resins and waxes, which are incompatible with each other and have a sea-island-like phase-separated structure. B is a toner in which the wax is encapsulated in the island-shaped resin B, wherein the resin A is mainly a polyester and / or a polyol and contains a THF-insoluble component, and the resin B has no THF-insoluble component. In the DSC curve of the resin B measured by the differential scanning calorimeter, the temperature of the maximum peak appearing on the endothermic side is from 62 to 90 ° C., and the weight-average molecular weight Mw of the THF-soluble component by GPC is expressed by the following formula (1). The main feature is an electrostatic image developing toner having a smaller value.

Mw = −300 × T + 32000 (1) (where T is the temperature of the largest peak appearing on the endothermic side of the DSC curve (unit: ° C.))

Second, in the toner for developing an electrostatic charge image according to claim 1, the resin A, the resin B and the SP of the wax are used.
Value (solubility parameter) is SP value of resin A> resin B
SP value of wax> SP value of wax

Thirdly, in the toner for developing an electrostatic image according to claim 1 or 2, the content of resin A, resin B and wax is such that resin A> resin B ≧ wax, and Resin A is 55 to the total amount of wax.
96% by weight, 2-44% by weight of resin B, 2% of wax
-15% by weight.

Fourthly, in the toner for developing an electrostatic image according to any one of claims 1 to 3, the temperature (° C.) of the maximum peak appearing on the endothermic side of the DSC curve of the resin B is the same as that of the resin A. It is higher than the temperature (° C.) of the maximum peak appearing on the endothermic side of the DSC curve.

Fifth, in the toner for developing an electrostatic image according to any one of claims 1 to 4, two or more types of mutually compatible resins are used as the resin A.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
Generally, hard resins have poor pulverizability. However, being hard, embedding of the external additive in the toner matrix and fusion of the toner to the carrier and other charging members are suppressed. Further, generation of a large amount of fine powder due to excessive pulverization and deterioration of development characteristics due to fine powder in a developing machine are small. Therefore, in the present invention, by dispersing a resin having good pulverizability in a hard resin, a toner having the advantage of a hard resin is obtained without inferior pulverizability even when a hard resin is used.

The toner of the present invention contains at least two or more resins and waxes, which are incompatible with each other, have a sea-island-like phase-separated structure, and are a continuous phase composed of a hard resin. Resin B having good pulverizability is dispersed in resin A in the form of islands, and wax is included in island-shaped resin B.

In a conventional toner having a sea-island structure in which wax is dispersed in the form of islands in a resin, crushing stress tends to concentrate on the interface between the resin and the wax at the time of crushing. Therefore, the crushed toner is easily crushed at the interface between the resin and the wax. The wax was exposed on the surface to the extent of the added wax or more, and this caused a decrease in transferability and durability. The toner of the present invention has a structure in which another resin B is dispersed in a sea-like resin A in an island shape and wax is included in the island-like resin B, so that the crushing stress is reduced by the resin A and the resin B. Can be concentrated also at the interface with the toner, reducing the amount of exposure of the wax to the pulverized toner surface, making the toner excellent in transferability and durability, and the wax exists near the toner surface. Therefore, there is almost no decrease in offset resistance. Further, the pulverizability is improved by increasing the number of incompatible surfaces where stress is concentrated, so that a toner having a small particle diameter can be manufactured with high production efficiency.

In particular, by making the resin B free of THF-insoluble components and having good pulverizability, pulverization not only at the interface but also within the resin B easily occurs, and the pulverizability is improved. At the same time, the probability that the wax exists near the toner surface can be increased, and the effect of preventing offset can be further improved. The resin having good grindability in the present invention is a resin having Mw smaller than the value calculated by the formula (1). (1) in the present invention
The formulas are T and M of the resin studied as constituting resin B.
It is an empirical formula obtained as a result of plotting the relationship of w and dividing it into those that can achieve the object of the present invention and those that cannot. However, if Mw is too small, there is a concern that viscosity may occur or only resin B may be offset, so that Mw of resin B is preferably 1500 or more. When the resin B contains a THF-insoluble component or when Mw is equal to or more than the value calculated by the formula (1), the pulverization probability inside the resin B is small, and the improvement of the pulverizability due to the increase of the incompatible interface is limited. Cheap.

In the toner of the present invention, a resin excellent in low-temperature fixability and hot offset resistance can be selected without considering the pulverizability and the dispersibility of the release agent for the resin A as the main component of the toner. Can be.

Therefore, the binder resin used for the resin A of the toner of the present invention is mainly a polyester resin and a polyol resin, and preferably contains a THF-insoluble component. If the THF-insoluble content is too large, the kneading state may deteriorate or the fixability may be impaired.
The THF-insoluble content is preferably 45% or less. Further, the resin A does not need to be one kind of resin, and it is easy to have desired resin characteristics by using two or more kinds. It is necessary that the resins constituting the resin A be compatible with each other. In this case, each of the two or more resins is T
It is not necessary to contain an HF-insoluble component, and it is sufficient that the compound contains a THF-insoluble component when blended.

In order to reliably form the toner structure of the present invention and to achieve the object, the SP value of the resin A, the resin B and the wax is determined as follows: SP value of the resin A> SP value of the resin B> wax. The SP value difference between the resin A and the resin B is 0.8 or more, and the resin A is 55 to 96% by weight and the resin B is 2 to 2% by weight based on the total amount of the resin and the wax in the toner.
It is important that 44% by weight and 2-15% by weight of wax be used.

In forming the islands-in-the-sea structure of the present invention, the state of the material constituting the toner at the time of melt-kneading is also important.
If the difference between the melt viscosities of the resin A and the resin B is too large, it is difficult to mix the two, and it is difficult to form a uniform sea-island structure. In the present invention, the temperature of the maximum peak appearing on the endothermic side of the DSC curve of resin B having a low molecular weight is determined by the DSC of resin A.
By setting the temperature higher than the maximum peak temperature appearing on the heat absorption side of the curve, the difference in melt viscosity during kneading of resin A and resin B is reduced, and a uniform sea-island structure is easily formed. Further, when the resin B having a high probability of being present on the particle surface has a high maximum peak temperature appearing on the endothermic side of the DSC curve, it is advantageous in terms of heat-resistant storage stability. In addition, D of binder resins A and B
The temperature of the maximum peak appearing on the heat absorption side of the SC curve is 62 to 75 in consideration of the low-temperature fixability and the storage stability.
C., and the binder resin B preferably has a temperature of 62 to 90C.

Method for Measuring Resin Property Value The SP value (solubility parameter: δ) of the resin used in the color toner of the present invention is determined by Hildebrand-Sc.
It is defined by the following equation in the solution theory of Atchard.

Δ = (ΔEv / V) 1/2 (where ΔEv is evaporation energy, V is molecular volume, ΔEv
/ V indicates the cohesive energy density. There are various ways to determine the SP value (solubility parameter).
In the present invention, values obtained by calculation mainly from the monomer composition using the method of Fedor et al. Were used.

SP value = (ΣΔei / ΣΔvi) 1/2 (where Δei is the evaporation energy of an atom or atomic group,
Δvi is the molar volume of an atom or atomic group. )

For the measurement of the THF-insoluble content, 1.0 g of the resin is weighed, 50 g of THF is added thereto, and the mixture is allowed to stand at 20 ° C. for 24 hours. This is filtered at room temperature using JIS standard (P3801) 5 type C quantitative filter paper. The paper residue after drying is weighed and expressed as a ratio (% by weight) between the resin used and the filter paper residue.

In the measurement of molecular weight by GPC, the column was stabilized in a heat chamber at 40 ° C., THF was passed through the column at this temperature at a flow rate of 1 ml per minute, and the sample concentration was 0.05 to 0.6. The measurement is performed by injecting 50 to 200 μl of a THF sample solution of the resin adjusted to the weight%. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve created from several types of monodisperse polystyrene standard samples and the count number. As standard polystyrene samples for creating calibration curves,
For example, Pressure Chemical Co. Or, the molecular weight of Toyo Soda Kogyo Co., Ltd. is 6 × 102, 2.1 ×
103, 4 × 103, 1.75 × 104, 5.1 × 10
4, 1.1 × 105, 3.9 × 105, 8.6 × 10
It is suitable to use 5, 2 × 106, 4.48 × 106, and at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

The temperature of the maximum peak appearing on the endothermic side of the DSC curve is determined by Rigaku THERMO manufactured by Rigaku Corporation.
According to FLEX TG8110, the heating rate is 10 ° C / mi.
It is measured under the condition of n.

Toner Constituent Material The binder resin used in the toner of the present invention includes:
In addition to the polyester resin and the polyol resin mainly used for the resin A, conventionally known resins can be widely used. For example, styrene, parachlorostyrene,
Vinyl toluene, vinyl chloride, vinyl acetate, vinyl propionate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate,
Dodecyl (meth) acrylate, 2- (meth) acrylate
Ethylhexyl, lauryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-chloroethyl (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide, (meth) Acrylic acid, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether. Vinyl methyl ketone, N-vinyl pyrrolidone, N-
Examples include a weight of a monomer such as vinylpyridine and butadiene, a copolymer of two or more of these monomers, or a mixture thereof. In addition, polyurethane resins, polyamide resins, epoxy resins, rosins, modified rosins, terpene resins, phenol resins, hydrogenated petroleum resins, and the like can be used alone or in combination.

Conventionally known waxes can be used as the release agent used in the toner of the present invention. For example, low-molecular-weight polyethylene, low-molecular-weight polyolefin wax such as low-molecular-weight polypropylene, synthetic hydrocarbon wax such as Fischer-Tropsch wax, beeswax, carnauba wax, candelilla wax, rice wax, natural waxes such as montan wax, Petroleum waxes such as paraffin wax and microcrystalline wax; higher fatty acids such as stearic acid, palmitic acid and myristic acid; metal salts of higher fatty acids; higher fatty acid amides; and various modified waxes thereof.

These can be used alone or in combination of two or more, but those having a melting point in the range of 70 to 125 ° C. are preferably used. By setting the melting point to 70 ° C. or higher, a toner having excellent transferability and durability can be obtained. By setting the melting point to 125 ° C. or lower, the toner is quickly melted at the time of fixing, and a reliable releasing effect can be exhibited. The use amount of these release agents is preferably 2 to 15% by weight based on the toner. If it is less than 1% by weight, the effect of preventing offset is insufficient, and if it is more than 15% by weight, transferability and durability are reduced. An important point in selecting a wax is that it is incompatible with resin B.

The dispersion diameter of the wax is preferably at most 1/2 of the major axis diameter of the toner from the viewpoint of transferability and durability. However, if the maximum dispersed particle diameter of the wax is 0.5 μm or less in the major axis diameter, the wax does not easily exude at the time of fixing, and the effect of preventing offset becomes insufficient.

As the colorant used in the toner of the present invention, conventionally known pigments and dyes can be used. For example,
Dyes and pigments such as carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, and triallylmethane dyes. These can be used alone or in combination of two or more.

The toner of the present invention can contain a charge control agent in the toner, if necessary. For example, nigrosine, an azine dye having an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), a basic dye (for example, CI Basic Yellow 2 (CI.41)).
000), C.I. I. Basic Yellow 3,
C. I. Basic Red 1 (CI. 4516)
0), C.I. I. Basic Red 9 (CI. 425)
00), C.I. I. Basic Violet 1 (C.I.
I. 42535), C.I. I. Basic Violet
3 (CI. 42555), C.I. I. Basic V
iolet 10 (CI. 45170), C.I. I. B
asic Violet 14 (CI. 4251)
0), C.I. I. Basic Blue 1 (CI.4
2025), C.I. I. Basic Blue 3 (C.I.
I. 51005), C.I. I. Basic Blue 5
(C.I. 42140), C.I. I. Basic Blu
e7 (CI. 42595), C.I. I. Basic
Blue 9 (CI. 52015), C.I. I. Bas
icBlue 24 (CI. 52030), C.I. I.
Basic Blue 25 (CI52025),
C. I. Basic Blue 26 (CI.440)
45), C.I. I. Basic Green 1 (C.I.
I. 42040), C.I. I. Basic Green
Lake lakes of these basic dyes, such as C.4 (CI.42000); I. Solvent Black 8
(C.I. 26150), quaternary ammonium salts such as benzoylmethylhexadecylammonium chloride and decyltrimethylchloride; dialkyltin compounds such as dibutyl or dioctyl; dialkyltin borate compounds; guanidine derivatives; and vinyl containing amino groups. -Based polymers, polyamine resins such as condensation polymers containing amino groups, and the like, are described in JP-B-41-20153, JP-B-43-27596, JP-B-44-6397, and JP-B-45-26478. Metal complex salts of monoazo dyes, such as salicylic acid, dialkylsalicylic acid, naphthoic acid, and dicarboxylic acids Zn, Al, Co, Cr, Fe described in JP-B-55-42752 and JP-B-59-7385. Metal complexes, such as sulfonated copper foil Roshianin pigments, organic boron salts,
Examples thereof include fluorinated quaternary ammonium salts and calixarene-based compounds. For color toners other than black, the use of a charge control agent that impairs the intended color should of course be avoided, and a white salicylic acid derivative metal salt or the like is preferably used.

In the present invention, it is preferable to externally add hydrophobic-treated fine particles of silica or titanium oxide to the toner matrix. A lubricant such as fine particles of a metal salt of a metal or polyvinylidene fluoride may be used in combination. In particular, the transferability and humidity are increased by using the silica subjected to the hydrophobic treatment and the titanium oxide subjected to the hydrophobic treatment in combination and increasing the external addition amount of the titanium oxide subjected to the hydrophobic treatment to the external addition amount of the silica subjected to the hydrophobic treatment. Toner having excellent charge stability against the toner.

The following are typical examples of the hydrophobizing agent used here. Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane,
Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane,
3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane,
Vinylmethoxysilane, vinyl-tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, dimethylvinylchlorosilane, octyl-trichlorosilane, decyl-trichlorosilane,
Nonyl-trichlorosilane, (4-t-propylphenyl) -trichlorosilane, (4-t-butylphenyl)
-Trichlorosilane, dibentyl-dichlorosilane, dihexyl-dichlorosilane, dioctyl-dichlorosilane, dinonyl-dichlorosilane, didecyl-dichlorosilane, didodecyl-dichlorosilane, dihexadecyl-
Dichlorosilane, (4-t-butylphenyl) -octyl-dichlorosilane, dioctyl-dichlorosilane, didecenyl-dichlorosilane, dinonenyl-dichlorosilane, di-2-ethylhexyl-dichlorosilane, di-
3,3-dimethylbenzyl-dichlorosilane, trihexyl-chlorosilane, trioctyl-chlorosilane, tridecyl-chlorosilane, dioctyl-methyl-chlorosilane, octyl-dimethyl-chlorosilane, (4-t
-Propylphenyl) -diethyl-chlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilazane, hexaphenyldisilazane, hexatolyldisilazane and the like. In addition, titanate-based coupling agents and aluminum-based coupling agents can also be used.

The toner of the present invention can be used for both one-component development and two-component development. When the toner is used for a two-component developer, it is used by mixing with a carrier powder. As the carrier in this case, all known carriers can be used, and examples thereof include iron powder, ferrite powder, magnetite powder, nickel powder, glass beads, and the like, and those whose surfaces are coated with a resin or the like.

As the method for producing the toner of the present invention, a conventionally known method can be applied. As a device for kneading the toner, a batch type two-roll, a Banbury mixer or a continuous type twin-screw extruder, for example, Kobe Steel, Ltd. KTK twin screw extruder manufactured by Toshiba Machine Co., Ltd., TEM twin screw extruder manufactured by Toshiba Machine Co., Ltd., KCK 2
A screw extruder, a PCM type twin screw extruder manufactured by Ikegai Iron Works Co., Ltd., a KEX type twin screw extruder manufactured by Kurimoto Iron Works Co., Ltd., and a continuous single screw kneader, for example, a co-kneader manufactured by Buss Corporation are preferably used.

The melt-kneaded product obtained as described above is cooled and then pulverized. The pulverization is performed, for example, by coarsely pulverizing using a hammer mill or a rotoplex, and further using a fine pulverizer using a jet stream or a mechanical pulverizer. Can be used. It is desirable that the pulverization is performed so that the average particle size becomes 3 to 15 μm. Further, the pulverized product is adjusted to a particle size of 5 to 20 μm by an air classifier or the like. As needed,
The external additive is externally added to the base toner. The external additive is crushed by mixing and stirring the base toner and the external additive using a mixer, so that the external additive is coated on the toner surface.

EXAMPLES Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples. In the examples, all parts are parts by weight.

In the examples, the following evaluations were made. Crushability The toner was coarsely pulverized to an average particle size of 1 mm or less, and was obtained by a processing amount per unit time when pulverized under a certain condition using an IDS type pulverizer manufactured by Nippon Pneumatic. ◎: 4 kg or more, ○: 3 to 4 kg, Δ: 1 to 3 kg,
×: less than 1 kg, ▲: 4 kg or more, but a large amount of fine powder was generated (except for x and ▲, acceptable range) Wax dispersed toner particles were ultrathin sectioned to 100 μm, stained with ruthenium tetroxide, and then observed with a transmission electron microscope (TEM). )) And the photograph was taken at a magnification of 10,000. ◎: 0.5 μm to 1 μm, ： １: 1 μm to 1/3 of the particle size,
Δ: 1/3 to 1/2 of the particle size, ×: larger than 2/1 of the particle size,
▲: Smaller than 0.5 μm (except for x and ▲, allowable range)

About 20 g of the heat-resistant storage toner was placed in a 20-ml glass bottle, and after tapping was performed 50 times to firmly solidify the toner, the toner was allowed to stand in a constant temperature bath at 50 ° C. for 24 hours, and then the penetration was measured. ◎ ：
Penetration, ○: larger than 25 mm, Δ: 15 to 25 mm, ×:
15mm or less

[0044] Teflon as fixability fixing roller by remodeling of the fixing section of a Ricoh Co. copier MF-200 using (R) rollers,
Using a fixing device having a variable fixing temperature, Ricoh type 6200 paper was set therein and a copying test was performed.
The fixing temperature was changed every 5 ° C., and the cold offset occurrence temperature and the hot offset occurrence temperature were examined. Cold offset ：: less than 125 ° C., ○: 125 to 140 ° C., Δ: 140
° C to 155 ° C, ×: 155 ° C or more Hot offset A: Greater than 200 ° C, ：: 185 to 200 ° C, Δ: 17
0 to 185 ° C, ×: 170 ° C or less

A continuous copy test was performed using the apparatus and the recording paper evaluated for durability and fixability. The fixing temperature at this time is set to 1 for a toner having a cold offset occurrence temperature of less than 125 ° C.
The temperature was set to 40 ° C., and the other toners were set to the temperature at which cold offset occurred + 20 ° C. Q / M and image quality after 30,000 copies were compared with the initial state. ◎: Q / M hardly decreases, ：: Q / M decreases but image quality does not change, Δ: Q / M decreases and image quality changes but no problem, x: Q / M decreases The image quality deteriorates and the image quality deteriorates.

Example 1 Binder resin A (polyester resin (THF insoluble content: 5%, T value of DSC curve: 71 ° C., SP value: 10.6) 52 parts Binder resin B Styrene-methyl acrylate copolymer Resin (THF insoluble: none, DSC curve T value: 71 ° C., Mw: 10200, Mw calculated value of formula (1): 10700, SP value: 9.3) 40 parts Release agent (ester wax (melting point: 83 ° C, SP value: 8.2) 8 parts Colorant (carbon black) 10 parts Charge control agent (metal-containing azo dye) 2 parts After sufficiently stirring and mixing the above materials with a Henschel mixer,
The mixture was melt-kneaded at a temperature of 130 to 140 ° C. for about 30 minutes using a roll mill. After cooling the kneaded product to room temperature, it is roughly pulverized by a cutter mill, and pulverized by a fine pulverizer using a jet stream,
The volume average particle diameter of the base toner is 7 ±
The thickness was set to 1 μm. The pulverizability at this time was very good, but did not result in excessive pulverization. Observation of a TEM image of the thin film section of the base toner confirmed that wax was dispersed inside the island having the sea-island structure. To 100 parts by weight of the base toner, 0.4 parts by weight of hydrophobic silica and 0.6 parts by weight of titanium oxide were mixed with a Henschel mixer to obtain a toner. The heat resistance storage stability of this toner was good. 3 parts by weight of this toner is
The mixture was stirred with 7 parts by weight to obtain a properly charged developer. Using this developer, image evaluation and fixability evaluation were performed, and then a 30,000-sheet continuous copy test was performed. A toner having both low-temperature fixability and offset resistance was obtained, and there was no problem in durability evaluation. These results are summarized in Table 1.

Example 2 The polyester of the binder resin A in the toner constituting material of Example 1 was reduced from 52 parts to 42 parts, and another 10 parts of a resin compatible with this resin were added. The resins added are: Polyester resin (THF-insoluble content: none, DSC curve T value: 65 ° C., SP value: 11.0) 12 parts Also, the amount of wax was reduced from 8 parts by weight to 6 parts by weight.
These materials were subjected to the same processes as in Example 1 to obtain a toner having a volume average particle diameter of 7 ± 1 μm. The grindability at this time was almost the same as in Example 1. In addition, the T of the thin section of the base toner
When the dispersion state of the wax was examined from the observation of the EM image, many of the dispersion states were smaller than the dispersion diameter of Example 1. To this base toner, hydrophobic silica and titanium oxide were externally added as in Example 1 to form a toner, and this toner was mixed with a carrier and stirred and used as in Example 1 to evaluate the image. Evaluation and durability evaluation were performed. Since two types of resins were used, it was possible to obtain a configuration having better fixing properties of the resin itself than in Example 1, and the wax content was smaller than in Example 1, but the same hot offset resistance as in Example 1 was obtained. Sex was obtained. Further, the temperature at which cold offset occurred was lower than that in Example 1. The durability and the heat storage stability were as good as in Example 1.

Example 3 43 parts of binder resin A-1 (polyester resin (THF insoluble content: 26%, T value of DSC curve: 66 ° C., SP value: 10.8) 43 parts Binder resin A-2 (polyester resin) (THF insoluble content: none, DSC curve T value: 71 ° C., SP value: 11.3) 43 parts Binder resin B (styrene-butyl acrylate-methyl methacrylate copolymer resin (THF insoluble content: none, DSC) Curve T value: 75 ° C, Mw: 6200, Calculated Mw value of formula (1): 9500, SP value: 9.2) 8 parts Release agent (polyethylene wax, melting point: 100 ° C, SP value: 8.0) 6 parts Coloring agent (carbon black) 10 parts Charge control agent (metal salicylate compound) 2 parts The above materials were subjected to the same process as in Example 1 to obtain a toner having a volume average particle diameter of 7 ± 1 μm. Good crushability,
The generation of fine powder was small. Since the generation amount of the fine powder was smaller than that in Example 1, it is considered that the amount of the resin B was effective for the generation amount of the fine powder. Therefore, when the amount of the resin B is further increased as compared with the case of Example 1, it is considered that the effect of the present invention may not be exhibited. Observation of a TEM image of the thin film section of the base toner confirmed that wax was dispersed inside the island having the sea-island structure.
However, since most of the islands formed by the binder resin B are occupied by the wax, if the amount of the wax is larger than the amount of the binder resin B that forms the islands, the wax that is not included in the islands may also be present. It is expected that the effects of the present invention will not be sufficiently exhibited. This mother toner 1
To 100 parts by weight, 0.4 parts by weight of hydrophobic silica and 0.6 parts by weight of titanium oxide were mixed with a Henschel mixer to obtain a toner. The heat resistance storage stability of this toner was good.
Using this toner, a developer was prepared in the same manner as in Example 1,
Using this developer, image evaluation and fixability evaluation were performed, and then a 30,000-sheet continuous copy test was performed. The toner was able to achieve both low-temperature fixability and offset resistance, and had no problem in durability evaluation.

Example 4 Binder resin A-1 (polyester resin, THF-insoluble content: 39%, T value of DSC curve: 67 ° C., SP value: 10.6) 50 parts Binder resin A-2 (polyester resin) 30 parts of binder resin B (hydrogenated petroleum resin, THF insoluble matter: none, T value of DSC curve: 87 ° C., THF insoluble content: none, DSC curve T value: 72 ° C., SP value: 11.0) Mw: 1900, Calculated Mw of the formula (1): 5900, SP value: 9.0) 15 parts Release agent (ester wax, (melting point: 90 ° C., SP value: 8.2) 5 parts Colorant (carbon) Black) 10 parts Charge control agent (metal salicylate compound) 2 parts The above materials were converted into a parent toner having a volume average particle diameter of 7 ± 1 μm through the same steps as in Example 1. At this time, the pulverizability was good, The generation of fine powder was small. A toner was prepared by externally adding hydrophobic silica and titanium oxide in the same manner as in Example 1. The melt viscosity was low because the molecular weight of the binder resin B was low, but the binder resin A melted earlier than the binder resin B. The kneading state did not deteriorate, and the wax dispersion state was good, and the A value of the DSC curve of the binder resin B was high, so that the heat-resistant storage stability did not deteriorate. Example 1 using this toner
A developer was used in the same manner as described above, and image evaluation and fixability evaluation were performed using this developer. Thereafter, a 30,000-sheet continuous copy test was performed. The toner was able to achieve both low-temperature fixability and offset resistance, and had no problem in durability evaluation.

Comparative Example 1 50 parts of binder resin A (polyester, THF insoluble content: 5%, DSC curve T value: 71 ° C., SP value: 10.6) 50 parts Binder resin B (styrene-methyl acrylate copolymer) Resin, THF insolubles: none, DSC curve T value: 71 ° C., Mw: 20,600, Mw calculated value of formula (1): 10,700, SP value: 9.3) 40 parts Release agent (ester wax (melting point: 83 ° C., SP value: 8.2) 10 parts Colorant (carbon black) 10 parts Charge control agent (metal-containing azo dye) 2 parts Except for Mw of binder resin B, the same material as in Example 1 was used. Through the same steps as in Example 1, the volume average particle size was 7
A base toner of ± 1 μm was used. The pulverizability at this time was not bad, but was worse than in Example 1. Observation of a TEM image of the thin film section of the base toner confirmed that wax was dispersed inside the island having the sea-island structure. Many toners had a wax dispersion diameter slightly larger than that of Example 1 probably because the amount of wax was larger than that of the toner of Example 1. Hydrophobic silica and titanium oxide were externally added to this base toner in the same manner as in Example 1 to obtain a toner. The heat resistance storage stability of this toner was not a problem.
Using this toner, a developer was prepared in the same manner as in Example 1,
Using this developer, image evaluation and fixability evaluation were performed, and it was confirmed that both low-temperature fixability and offset resistance were compatible. Thereafter, a continuous copy test of 30,000 sheets was performed. As a result, an image was obtained in which the charge was reduced and the background stain was conspicuous. Since the binder resin B is not good in pulverizability, the pulverized surface becomes almost the interface between the binder resin A and the binder resin B and the interface between the binder resin B and the wax, and the amount of wax present on the particle surface is reduced. It is thought that it has increased.

Comparative Example 2 50 parts of binder resin A-1 (polyester resin, THF insoluble content: 33%, T value of DSC curve: 64 ° C., SP value: 10.8) 50 parts of binder resin A-2 (polyol resin) , THF insolubles: none, DSC curve T value: 61 ° C., SP value: 11.2) 27 parts Binder resin B (styrene-ethyl acrylate copolymer resin, THF insolubles: none, DSC curve T value) : 74 ° C, Mw: 10000, Mw calculated by the formula (1): 9800, SP value: 9.3) 15 parts Release agent (polyethylene wax (melting point: 100 ° C, SP value: 8.0) 8 parts Coloring Agent (carbon black) 10 parts Charge control agent (metal salicylate compound) 2 parts The above-mentioned material was subjected to the same process as in Example 1 to obtain a base toner having a volume average particle diameter of 7 ± 1 μm. B
Is smaller than the Mw of the binder resin B of Example 1, but the pulverizability was not good. Hydrophobic silica and titanium oxide were externally added to this base toner in the same manner as in Example 1 to obtain a toner. Using this toner, a developer was prepared in the same manner as in Example 1, and the fixing property was evaluated and then the durability was evaluated. Although there was no problem with respect to the low-temperature fixing property and the offset resistance, an image having background contamination was obtained in the durability evaluation. It is thought that not only the pulverizability was not good but also the pulverization inside the binder resin B was difficult to occur, which resulted from the large amount of wax present on the particle surface. Also, the heat-resistant storage stability was not so good. From this comparative example, it can be seen that even if Mw is small, if it is larger than the value calculated by the equation (1), the object of the present invention cannot be achieved.

Comparative Example 3 70 parts of binder resin A (polyester resin, THF insoluble content: 10%, T value of DSC curve: 68 ° C., SP value: 10.6) 70 parts of binder resin B (styrene-methyl acrylate) Methyl methacrylate copolymer resin (THF insoluble: none, DSC curve T value: 72 ° C, Mw: 9700, Mw calculated value of formula (1): 10400, SP value: 9.3) 25 parts Release agent ( Ester wax (melting point: 92 ° C., SP value: 9.1) 5 parts Colorant (carbon black) 10 parts Charge control agent (salicylic acid metal salt compound) 2 parts The base toner having an average particle diameter of 7 ± 1 μm was obtained, although the pulverizability at this time was not poor, but worse than that of Example 1. When a TEM image of a thin film section of the base toner was observed, it was found that Umijima Structure is certain However, it was difficult to confirm the dispersion of the wax, and hydrophobic silica and titanium oxide were externally added to the base toner in the same manner as in Example 1. Using this toner, the same procedure as in Example 1 was performed. As a developer, image evaluation and fixability evaluation were performed using this developer, and an offset was generated at a temperature that was not so high.

Comparative Example 4 Binder resin A-1 (polyester resin, THF insoluble content: 24%, DSC curve T value: 68 ° C., SP value: 10.6) 40 parts Binder resin A-2 (polyester resin) , THF insolubles: none, DSC curve T value: 68 ° C., SP value: 11.0) 40 parts Binder resin B (styrene-methyl acrylate copolymer resin, THF insolubles: none, DSC curve T value) : 59 ° C, Mw: 5000, Mw calculated by the formula (1): 14300, SP value: 9.3) 15 parts Release agent (polyethylene wax) 5 parts (melting point: 100 ° C, SP value: 8.0) Coloring agent (carbon black) 10 parts Charge control agent (salicylic acid metal salt compound) 2 parts The above materials were subjected to the same processes as in Example 1 to obtain a base toner having a volume average particle diameter of 7 ± 1 μm. The pulverizability at this time was good, and the generation of fine powder was small. Observation of the TEM image of the thin film section of the base toner confirmed the sea-island structure and the dispersion of the wax in the island portion. Hydrophobic silica and titanium oxide were externally added to this base toner in the same manner as in Example 1 to obtain a toner. Using this toner, a developer was prepared in the same manner as in Example 1, and image evaluation, fixability evaluation, and durability evaluation were performed using this developer. There was no problem in durability. However, heat storage stability was poor.

[0054]

[Table 1]

[0055]

As described above, according to the first aspect of the present invention, another resin B is dispersed in a sea-like resin A in an island shape, and the island-like resin B
Because of the structure in which the wax is included, the crushing stress is also concentrated on the interface between the resin A and the resin B, the amount of the wax exposed on the toner surface is reduced, and the toner having excellent transferability and durability is provided. And the wax existing near the toner surface does not lower the offset resistance. Further, the pulverizability is improved by increasing the number of incompatible surfaces where stress is concentrated, so that a toner having a small particle diameter can be manufactured with high production efficiency.

According to the invention of claim 2, the SP value (solubility parameter) of the resin A, the resin B and the wax is such that
Since P value> SP value of resin B> SP value of wax, the toner structure of the present invention can be reliably formed.

According to a third aspect of the present invention, the content of resin A, resin B and wax is such that resin A> resin B ≧ wax,
Since the resin A is 55 to 96% by weight, the resin B is 2 to 44% by weight and the wax is 2 to 15% by weight based on the total amount of the resin and the wax in the toner, the toner structure of the present invention can be surely obtained. Can be formed.

According to the fourth aspect of the present invention, the temperature (° C.) of the maximum peak that appears on the endothermic side of the DSC curve of the resin B is the temperature (° C.) of the maximum peak that appears on the endothermic side of the DSC curve of the resin A.
Since it is higher, the difference in melt viscosity at the time of kneading the resin A and the resin B is small, and a uniform sea-island structure is easily formed.
Further, since the maximum peak temperature of the resin B having a high probability of being present on the particle surface is increased, the resin B is also advantageous in terms of heat resistance storage stability.

According to the fifth aspect of the present invention, since two or more types of mutually compatible resins are used as the resin A, it is easy to obtain desired resin characteristics, and the toner performance such as low-temperature fixability and hot offset resistance is further improved. Can be done.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahide Yamashita 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Kazuto Watanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Mitsuteru Kato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Maiko Kondo 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. F term (reference) 2H005 AA01 AA06 AA15 CA08 CA13 CA14 CA15 CA17 EA03 EA06 EA07 EA10

Claims (5)

[Claims] 1. A resin containing at least two types of resins and waxes, which are incompatible with each other and have a sea-island-like phase-separated structure. B is a toner in which wax is encapsulated in the island-shaped resin B, and the resin A is mainly a polyester and / or a polyol and contains a THF-insoluble component.
Has no THF insoluble matter, the temperature of the maximum peak appearing on the endothermic side in a DSC curve measured by a differential scanning calorimeter is 62 to 90 ° C., and the weight-average molecular weight Mw of the THF-soluble matter by GPC is as follows (1) A toner for developing an electrostatic image, wherein the toner is smaller than the value of the formula. Mw = −300 × T + 32000 (1) (where T is the temperature of the largest peak appearing on the endothermic side of the DSC curve (unit: ° C.)) 2. The resin according to claim 1, wherein the SP value (solubility parameter) of the resin A, the resin B and the wax is SP value of the resin A> SP value of the resin B> SP value of the wax. An electrostatic image developing toner. 3. The content of resin A, resin B and wax is such that resin A> resin B ≧ wax, 55 to 96% by weight of resin A based on the total amount of resin and wax in the toner, and resin B The toner for developing electrostatic images according to claim 1, wherein the content of the toner is 2 to 44% by weight and the content of the wax is 2 to 15% by weight. 4. The temperature (° C.) of the maximum peak appearing on the endothermic side of the DSC curve of resin B is higher than the temperature (° C.) of the maximum peak appearing on the endothermic side of the DSC curve of resin A. The toner for developing electrostatic images according to claim 1. 5. The electrostatic image developing toner according to claim 1, wherein two or more types of mutually compatible resins are used as the resin A.