JP2003122052A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which exhibits a stable electrostatic charge behavior even in a long-term use or printing of a multiplicity of number of copies and makes it possible to obtain printing images which is little in fogging, has high resolution and high gradation characteristics and does not change image density and to provide an electrostatic charge image developing toner which has a high transfer rate from a photoreceptor to a material to be printed, such as paper, in development. SOLUTION: The electrostatic charge image developing toner containing a polyester resin as a binder resin and having an average circularity of >=0.97, is characterized in that the surface of the toner is treated with a silicone oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic charge image, which is preferably used in electrophotographic copying machines, printers, fax machines and the like, and is also used in toner jet type printers.

[0002]

2. Description of the Related Art Heretofore, a toner for obtaining a visible image by an electrophotographic method has been a method in which a polyester resin, a colorant and other additives are melt-kneaded and then finely pulverized by a mechanical or air pulverizer. It has been manufactured by

On the other hand, recently, cost reduction, downsizing, power saving, resource saving, etc. of a machine have been actively studied, and the toner used in the machine is changed from a photoconductor to a printed material such as paper. A high transfer rate is required, and at the time of fixing, it is required that the heat roll is not contaminated and the image is firmly fixed to the printed material with low energy. Furthermore, in the image quality of the finally obtained printed matter, high resolution and Wide gradation is required.

The average particle diameter of the toner currently used is about 7 to 15 μm, but it is necessary to further reduce the average particle diameter in order to improve the resolution and gradation of a printed image. In principle, it is possible to reduce the particle size of powder toners that have been conventionally used by the pulverization method.However, as the particle size is reduced, colorants, charge control agents, or additives such as waxes may be added. It becomes difficult to control charging because the ratio of exposure to the surface of toner particles increases, and the durability in multi-copy printing deteriorates. do not do,
It is practically difficult to sufficiently satisfy the above requirements due to problems such as a rise in energy cost required for manufacturing.

Under these circumstances, the development of spherical toners by the polymerization method or the emulsion dispersion method is now being actively studied. Regarding the toner by the polymerization method, various methods are known, among them, a monomer, a polymerization initiator,
A colorant and a charge control agent are uniformly dissolved or dispersed, and the mixture is added to an aqueous medium with stirring in the presence of a dispersion stabilizer to form oil droplets. A suspension polymerization method for producing toner particles by performing the above is widely used.

By the way, as a binder resin for toner,
Although various resins can be used, polyester resins have recently been preferably used because they have excellent low-temperature fixability, the image after fixing is tough, and has a relatively high glass transition point. However, although the above-mentioned polymerization method can reduce the toner particle size and make the toner particles spherical, since the binder resin is limited to the radical-polymerizable vinyl polymer, the toner is produced by the polyester resin. I can't. Further, the polymerization method has a problem that it is difficult to reduce VOC (a volatile organic compound including unreacted monomers).

A method for producing a toner by an emulsion dispersion method using a polyester resin is disclosed in JP-A-8-21655. This publication describes a method in which a mixture of a polyester resin and a colorant is mixed with an aqueous medium and emulsified to obtain toner particles. As with the polymerization method, it is possible to easily reduce the particle size and spheroidize the toner. In addition to being able to do, VOC has a wider selection range of binder resin types than the polymerization method.
It has advantages that it can be easily reduced and that the concentration of the colorant or the like can be arbitrarily changed from a low concentration to a high concentration.

However, the toner produced by such an emulsification dispersion method should still be improved in terms of ensuring the charging stability in long-term use or printing a large number of copies, eliminating fog, stabilizing image density, and the like. Points are left. In particular, in recent years, it has been desired to develop a toner suitable for a copying machine capable of high-speed printing, a printer, or the like. For example, when converted into the number of processed A4 sheets, about 30 sheets / minute for an office printer, About 60 to 100 sheets / minute with a copying machine, especially, in the future, the processing speed will be 60 sheets / minute in the vertical direction of A4 paper, 100 sheets / minute in the horizontal direction of A4 paper, and the developing speed will be 20 m / minute. Alternatively, there is a need for a toner having excellent developing characteristics in a high-speed printing machine corresponding to 30 m / min or more.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to exhibit stable charging behavior even during long-term use or multi-copy printing and to reduce fog. Another object of the present invention is to provide a toner for developing an electrostatic charge image capable of obtaining a printed image having a constant image density. Another object of the present invention is to provide a high resolution,
An object of the present invention is to provide a toner for developing an electrostatic charge image capable of obtaining a high quality image with high gradation. Another object of the present invention is to provide a toner for developing an electrostatic image having a high transfer rate from a photoconductor to a printing material such as paper during development.

[0010]

As a result of intensive studies to solve the above problems, the present inventors have found that the toner contains a polyester resin as a binder resin and the surface of the toner is treated with silicone oil. The present invention has been completed by finding that spherical toner having a spherical shape solves the above problems.

That is, the present invention is a toner for developing an electrostatic charge image containing a polyester resin as a binder resin and having an average circularity of 0.97 or more, the surface of which is treated with silicone oil. The present invention provides a toner for developing an electrostatic charge image characterized by the above.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The polyester resin that can be used in the present invention can be obtained, for example, by dehydration condensation of a dicarboxylic acid and a diol by a usual method. Examples of the dicarboxylic acid include phthalic anhydride,
Terephthalic acid, isophthalic acid, orthophthalic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid,
Examples thereof include dicarboxylic acids such as succinic acid, malonic acid, glutaric acid, azelaic acid and sebacic acid, or derivatives thereof.

As the diol, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, bisphenol A, polyoxyethylene- (2.0 ) -2,2-bis (4-hydroxyphenyl) propane and its derivatives,
Polyoxypropylene- (2.0) -2,2-bis (4
-Hydroxyphenyl) propane, polyoxypropylene- (2.2) -polyoxyethylene- (2.0)-
2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene-
(2.2) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene- (2.4) -2,2
-Bis (4-hydroxyphenyl) propane, polyoxypropylene- (3.3) -2,2-bis (4-hydroxyphenyl) propane and its derivatives, and the like.

Further, for example, polyethylene glycol,
It is also possible to use diols such as polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, and polycaprocactone diol.

If necessary, a trifunctional or more aromatic carboxylic acid such as trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride or a derivative thereof, or sorbitol, 1, 2, 3 is used. , 6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,
Trifunctional or higher alcohols such as 5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trimethylolbenzene. Or bisphenol A type epoxy resin, bisphenol F type epoxy resin, ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, N, N-diglycidyl aniline, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane Triglycidyl ether, pentaerythritol tetraglycidyl ether, cresol novolac type epoxy resin, phenol novolac type epoxy resin, epoxy group-containing vinylation Use of a polyfunctional epoxy compound having three or more functional groups such as a polymer or a copolymer of the product, an epoxidized resorcinol-acetone condensate, a partially epoxidized polybutadiene, and one or more of semi-dry or dry fatty acid ester epoxy compounds. You can also

The polyester resin in the present invention can be obtained by carrying out a dehydration condensation reaction or a transesterification reaction using the above raw material components in the presence of a catalyst.
The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.

As the catalyst for carrying out the above reaction, for example, tetrabutyl titanate, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, etc. can be used appropriately.

In such a polycondensation reaction, in order to produce a branched or crosslinked polyester resin, a polybasic acid having 3 or more carboxyl groups in one molecule or an anhydride thereof, and / or A polyhydric alcohol having 3 or more hydroxyl groups in one molecule may be used as an essential synthetic raw material.

The polyester resin thus obtained preferably has a value measured by a constant load extrusion type capillary rheometer (hereinafter referred to as a flow tester) within the following range. That is, the outflow starting temperature Tfb by the flow tester is in the range of 80 ° C to 120 ° C, T1 /
2 Temperature is in the range of 120 ° C to 180 ° C, outflow end temperature Te
nd is in the range of 130 ° C to 210 ° C. By using the polyester resin having such a flow tester value, the toner for developing an electrostatic image of the present invention has good oilless fixing property. Further, the glass transition temperature (Tg) is preferably 40 to 75 ° C.

Outflow start temperature Tf by a flow tester
In the present invention, the b, T1 / 2 temperature and outflow end temperature Tend are obtained using a Shimadzu flow tester (CFT-500). This flow tester is shown in Figure 1.
As shown in (a), a cylinder 2 having a nozzle 1 having a nozzle diameter D of 1.0 mmΦ and a nozzle length (depth) L of 1.0 mm is filled with resin 3 (weight 1.5 g), and the nozzle 1
Stroke S of load surface 4 (sink value of load surface 4) when a load of 10 kg per unit area (cm ² ) is applied from the opposite side and heating is performed at that rate at a temperature rising rate of 6 ° C. per minute Obtained by measuring. That is, the relationship between the increased temperature and the stroke S is obtained as shown in FIG. 1 (b), and when the flow of the resin 3 from the nozzle 1 starts and the stroke S rapidly increases and the curve rises. The temperature is set to Tfb, and the temperature when the curve of the resin 3 is almost finished after the outflow of the resin 3 from the nozzle 1 is set to Tend. Then, the strokes Sfb and Te at Tfb
S1 which is an intermediate value of the stroke Send when nd
The temperature at / 2 is the T1 / 2 temperature.

In the measurement by the temperature rising method using this device, the test is conducted while raising the temperature at a constant rate as the test time elapses, so that the sample changes from the solid region to the transition region, the rubber-like elastic region to the fluid region. The process up to the point can be continuously measured. With this device, the shear rate and viscosity at each temperature in the flow region can be easily measured.

The outflow start temperature Tfb is an index of the sharp melting property and low temperature fixing property of the polyester resin,
If the temperature is too high, the low temperature fixability is deteriorated and cold offset is likely to occur. Further, if the temperature is too low, the storage stability is lowered and hot offset is likely to occur. Therefore, the outflow starting temperature Tfb of the toner for developing an electrostatic image of the present invention is more preferably 90 ° C to 115 ° C, and particularly preferably 90 ° C to 110 ° C.

Further, the melting temperature T of the toner by the 1/2 method
1/2 and the outflow end temperature Tend are indicators of hot offset resistance, and if both are too high, the solution viscosity increases and the particle size distribution during particle formation deteriorates. Further, if both are too low in temperature, offsetting tends to occur and the practicality is lowered. Therefore, 1/2
The melting temperature T1 / 2 by the method is preferably 120 ° C to 180 ° C, more preferably 130 ° C to 160 ° C, and the outflow end temperature Tend is preferably 130 ° C to 210 ° C.
130 ° C to 180 ° C is more preferable. Tfb, T1 /
2. By setting Tend within the above range, fixing can be performed in a wide temperature range.

The above-mentioned polyester resin contains a crosslinked polyester resin, and the tetrahydrofuran insoluble content of the binder resin is in the range of 0.1 to 20% by weight, more preferably 0.2 to 10% by weight. Range, more preferably in the range of 0.2 to 6% by weight. Thus, by using a binder resin as a polyester resin having a tetrahydrofuran insoluble content of 0.1 to 20% by weight, good hot offset resistance can be obtained. This can be ensured and is preferable. 0.
If it is less than 1% by weight, the hot offset resistance improving effect is insufficient, which is not preferable. If it is more than 20% by weight, the solution viscosity becomes too high, the fixing start temperature becomes high, and the balance of the fixability is lost, which is not preferable. Also,
Since the sharp melt property is impaired, the transparency, color reproducibility and gloss in a color image are deteriorated, which is not preferable.

As for the above-mentioned tetrahydrofuran-insoluble matter of the binder resin, 1 g of the resin was precisely weighed, added to 40 ml of tetrahydrofuran and completely dissolved, and a funnel (diameter: Kiriyama filter paper (No. 3)) was placed. 2 g of radiolite (# 700 manufactured by Showa Kagaku Co., Ltd.) is evenly laid on 40 mm) and filtered, the cake is placed on an aluminum petri dish, and then dried at 140 ° C. for 1 hour, and the dry weight is measured. Then, the value obtained by dividing the residual resin amount in the dry weight by the initial resin sample amount is calculated as a percentage, and this value is taken as the insoluble matter.

Further, the binder resin more preferably contains a low-viscosity branched or linear polyester resin. That is, in the polyester resin of the present invention, the binder resin may be composed of one type of polyester resin, but in general, a crosslinkable polyester resin having a high molecular weight and high viscosity (crosslinked polyester resin)
And a branched or linear polyester resin having a low viscosity and a low molecular weight are blended and used in practice for the production of the resin and also for obtaining a good fixing start temperature and hot offset resistance. And preferred. When blended and used, the flow tester value of the blended resin should be within the above numerical range. In the present invention, the crosslinked polyester resin refers to a resin having a component insoluble in tetrahydrofuran, and the branched or linear polyester resin refers to a resin in which an insoluble matter is not detected by the above-described method for measuring tetrahydrofuran insoluble matter.

In the present invention, a plurality of polyester resins having different melt viscosities can be used as the binder resin,
For example, when using a mixture of a low-viscosity branched or linear polyester resin and a crosslinked polyester resin,
It is more preferable to use a mixture of a branched or linear polyester resin (A) and a crosslinked or branched polyester resin (B) under the following conditions. At this time, the flow tester value of the blended resin is preferably within the above numerical range.

That is, as the polyester resin (A), the T1 / 2 temperature by the flow tester is 80 ° C. or higher, 12
It is less than 0 ° C and has a glass transition temperature Tg of 40 ° C to 80 ° C.
As a branched or linear polyester resin, or polyester resin (B), T1 /
2 The temperature is 120 ° C. or higher and 210 ° C. or lower, and the glass transition temperature Tg is 50 to 85 ° C., which is a cross-linked or branched polyester resin, and the weight ratio of the polyester resin (A) and the polyester resin (B). But,
(A) / (B) = 20/80 to 80/20, and the T1 / 2 temperatures are T1 / 2 (A) and T1 / 2, respectively.
When (B) is used, a material having a relationship of 20 ° C. <T1 / 2 (B) −T1 / 2 (A) <100 ° C. is preferably used.

Considering each temperature characteristic by the flow tester, the melting temperature T1 / 2 of the resin (A) by the 1/2 method is
(A) is an index for imparting sharp melt property and low temperature fixability, and T1 / 2 (A) is 80 to 115 ° C.
Is more preferable, and the range of 90 to 110 ° C. is particularly preferable.

Resin (A) defined by these performances
Has a low softening temperature, and in the fixing process using a heat roll, it melts sufficiently even when the applied heat energy decreases due to a lower temperature of the heat roll or a faster process speed, and provides cold offset resistance and low-temperature fixability. Demonstrate excellent performance.

Melting temperature T1 of resin (B) by 1/2 method
If both / 2 (B) and the outflow end temperature Tend (B) are too low, hot offset is likely to occur, and if they are too high, the particle size distribution during particle formation deteriorates and productivity decreases. Therefore, T1 / 2 (B) is 125
C. to 210.degree. C. is more preferable, 130.degree. C. to 2
It is particularly preferable that the temperature is 00 ° C.

Resin (B) defined by these performances
Has a strong rubber elasticity and a high melt viscosity, so that the internal cohesive force of the melted toner layer is maintained even during heating and melting in the fixing process, hot offset does not easily occur, and the toughness of the toner after fixation is high. Exhibits excellent abrasion resistance.

By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner which sufficiently satisfies anti-offset performance and low-temperature fixing performance in a wide temperature range.

Weight ratio of resin (A) and resin (B) (A)
If / (B) is too small, it affects the fixability,
Further, when it is too large, the offset resistance is affected, so that it is preferably 20/80 to 80/20, and more preferably 30/70 to 70/30.

[1/2] of resin (A) and resin (B)
Melting temperature by the method is T1 / 2 (A), T1 / 2, respectively
In the case of (B), in order to achieve both low-temperature fixability and offset resistance, and to facilitate uniform mixing without causing a problem due to a difference in viscosity between resins, T1 / 2
The range of (B) -T1 / 2 (A) exceeds 20 ° C, 90 ° C
The temperature is more preferably below, and particularly preferably more than 20 to 80 ° C.

The glass transition temperature (Tg) of the polyester resin of the present invention is, in the present invention, a differential scanning calorimeter (DSC-50) manufactured by Shimadzu Corporation at a heating rate of 10 ° C./min by the second run method. It is the value obtained by measurement.

When the Tg of the polyester resin (A) is less than 40 ° C. or the Tg of the polyester resin (B) is less than 50 ° C., the obtained toner is blocked during storage or in a developing machine (toner particles are aggregated). Phenomenon that becomes a lump)
Is likely to occur, which is not preferable. On the other hand, if the Tg of the polyester resin (A) exceeds 80 ° C. or the Tg of the polyester resin (B) exceeds 85 ° C., the fixing temperature of the toner becomes high, which is not preferable. As described above, by using the polyester resin (A) and the polyester resin (B) having the above relationship as the polyester resin serving as the binder resin, the obtained toner has a better fixing property, which is preferable. .

Further, the binder resin made of a polyester resin has a weight average molecular weight of 30,000 or more, preferably 37, by the molecular weight measurement by gel permeation chromatography (GPC) method of a tetrahydrofuran (THF) soluble component. 000 or more, weight average molecular weight (Mw)
/ Number average molecular weight (Mn) is 12 or more, preferably 15 or more, and the area ratio of the components having a molecular weight of 600,000 or more is 0.
3% or more, preferably 0.5% or more, the area ratio of the components having a molecular weight of 10,000 or less is 20 to 80%, preferably 30 to 7
It is preferable that the condition of 0% is satisfied in order to obtain good fixing property. When a plurality of resins are blended, the GPC measurement result of the final resin mixture should fall within the above numerical range.

In the polyester resin used in the toner of the present invention, the high molecular weight component having a molecular weight of 600,000 or more has a function of ensuring hot offset resistance. on the other hand,
The low molecular weight component having a molecular weight of 10,000 or less is effective for lowering the melt viscosity of the resin, exhibiting sharp melt properties and lowering the fixing start temperature, and it is preferable to contain a resin component having a molecular weight of 10,000 or less. In order to obtain good thermal properties such as low temperature fixing, hot offset resistance and transparency in the oilless fixing method, the binder resin preferably has such a broad molecular weight distribution. Further, in the granulation of fine particles by a solvent-free emulsification dispersion method, it is preferable to contain a low molecular weight component because the melt viscosity of the resin is lowered.

Here, the molecular weight of the THF-soluble component of the binder resin is determined by filtering the THF-soluble substance with a 0.2 μm filter and then using Tosoh's GPC HLC-8120 and Tosoh's column “TSKgel Super HM-M”. (15 cm)
Using three THF solvents (flow rate 0.6 ml / min,
The temperature is measured at 40 ° C.), and the molecular weight is calculated by using the molecular weight calibration curve prepared from the monodisperse polystyrene standard sample.

The acid value of the polyester resin is 3 to 20.
A range of mgKOH / g is preferred. The acid value of the polyester resin is a raw material other than the addition of a monocarboxylic acid and / or a monoalcohol to the polyester resin obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol as described above. It can be adjusted by controlling the terminal carboxyl group of the polyester by adjusting the compounding ratio and reaction rate of the polybasic acid and the polyhydric alcohol.
Alternatively, by using trimellitic anhydride as the polybasic acid component, it is possible to form a polyester having a carboxyl group in the main chain.

The electrostatic image developing toner of the present invention is
The following formula, average circularity = (circumferential length of a circle having the same area as the projected area of particles) /
A spherical or substantially spherical shape having an average circularity defined by (perimeter of projected image of particles) of 0.97 or more, preferably 0.98 or more.

By having such a spherical shape or a substantially spherical shape, the toner for developing an electrostatic charge image of the present invention can secure good powder fluidity even when the particle size is reduced, and also has good transfer efficiency. It is also possible to secure the image quality, and thereby excellent image quality (resolution and gradation) can be formed.
When the average circularity is smaller than 0.97, that is, when the shape approaches from a spherical shape to an irregular shape, the transfer efficiency decreases, which is not preferable. The average circularity is the SE of the toner particles.
It can be obtained by taking an M (scanning electron microscope) photograph and measuring and calculating it, but it can be easily obtained by using the flow particle image analyzer FPIP-1000 manufactured by Toa Medical Electronics Co., Ltd. In the present invention, the measurement was performed using this device.

As the colorant which can be used in the present invention, known ones can be mentioned. Carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black, etc., which are classified according to the manufacturing method, is used as a black colorant, and phthalocyanine-based C.I. I. Pigment Bl
ue 1,2,15: 1,15: 2,15: 3,15:
4,15: 6,15,16,17: 1,27,28,2
9, 56, 60, 63 and the like. As the bluish colorant, preferably C.I. I. Pigment Blue
15: 3 (generic name Phthalocyanine Blue G), 15
(Phthalocyanine blue R), 16 (metal-free phthalocyanine blue), 60 (indanthrone blue), most preferably C.I. I. Pigment Blu
e 15: 3, 60.

As a yellow colorant, for example,
C. I. Pigment Yellow 1, 3, 4,
5, 6, 12, 13, 14, 15, 16, 17, 18,
24, 55, 65, 73, 74, 81, 83, 87, 9
3,94,95,97,98,100,101,10
4,108,109,110,113,116,11
7,120,123,128,129,133,13
8,139,147,151,153,154,15
5,156,168,169,170,171,17
2,173,180 and the like, and preferably C.I. I.
Pigment Yellow 12 (generic name disazo yellow AAA), 13 (disazo yellow AAM
X), 17 (Disazo Yellow AAOA), 97 (Fast Yellow FGL), 110 (Isoindolinone Yellow 3RLT), 155 (Sandrin Yellow 4)
G) and 180 (benzimidazolone yellow), most preferably C.I. I. Pigment Y
ellow 17, 155 and 180.

Further, the red colorant is, for example, C.I.
I. Pigment Red 1, 2, 3, 4, 5,
6,7,8,9,10,12,14,15,17,1
8, 22, 23, 31, 37, 38, 41, 42, 4
8: 1, 48: 2, 48: 3, 48: 4, 49: 1,4
9: 2, 50: 1, 52: 1, 52: 2, 53: 1, 5
4,57: 1,58: 4,60: 1,63: 1,63:
2, 64: 1, 65, 66, 67, 68, 81, 83,
88, 90, 90: 1, 112, 114, 115, 12
2,123,133,144,146,147,14
9,150,151,166,168,170,17
1,172,174,175,176,177,17
8,179,185,187,188,189,19
0,193,194,202,208,209,21
4,216,220,221,224,242,24
3, 243: 1, 245, 246, 247 and the like, and preferably C.I. I. Pigment Red 4
8: 1 (generic name barium red), 48: 2 (calcium red), 48: 3 (strontium red), 4
8: 4 (manganese red), 53: 1 (lake red), 57: 1 (brilliant carmine 6B), 122
(Quinacridone magenta 122) and 209 (dichloroquinacridone red), most preferably C.I. I. Pigment Red 57: 1, 122 and 209.

The content of the colorant is preferably 1 to 20 parts by weight. Among them, 1 to 15 parts by weight is preferable, and 1 to 10 parts by weight is particularly preferable. These colorants may be used either individually or in combination of two or more.

In the toner of the present invention, various known waxes such as polypropylene wax, polyethylene wax, polyamide wax, Fischer-Tropsch wax and the like can be appropriately used as a mold release agent. A wax containing an ester compound and / or an aliphatic alcohol compound is preferably used as a release agent.

Among the waxes containing a higher fatty acid ester compound and / or an aliphatic alcohol compound, natural waxes such as carnauba wax, montan ester wax, rice wax, scale wax, and / or synthetic ester wax are particularly preferable. . As the synthetic ester wax, tetrabehenic acid ester of pentaerythritol is particularly preferable.

These ester waxes exhibit particularly good dispersibility in the polyester resin of the present invention, fixability,
The offset resistance is remarkably improved. Further, even when a large number of these waxes are printed for a long time, for example, when used as a non-magnetic one-component developing toner, the wax does not adhere to the charging member pressed against the developing sleeve,
The toner is stably charged, and there are no image defects or background stains, and high-quality and high-definition images can be printed. Further, when a color toner is used by using it together with a chromatic colorant, a color toner having excellent transparency is obtained as compared with a hydrocarbon wax such as polypropylene wax. A color toner having such characteristics has transparency and is suitable for printing on an OHP sheet for which a vivid projection image is required, and for printing an intermediate color with good color reproducibility by printing two or more colors in an overlapping manner. Are suitable.

As carnauba wax, it is preferable to use free fatty acid type carnauba wax from which free fatty acids have been removed by purification. The acid value of the free fatty acid type carnauba wax is preferably 3 or less, more preferably 2 or less. The free fatty acid type carnauba wax becomes finer crystals than the conventional carnauba wax, and the dispersibility in the polyester resin is improved. The montan ester wax is refined from minerals, and by refining, it becomes microcrystalline like carnauba wax, and dispersibility in the polyester resin is improved. The acid value of the montan ester wax is preferably 30 or less. The rice wax is a refined rice bran wax, and preferably has an acid value of 13 or less. Scale insect wax is scale insect (also known as rotifer)
Waxy ingredients secreted by the larvae of, for example, dissolved in boiling water,
It can be obtained by separating the upper layer after cooling and solidifying, or by repeating it. The scale insect wax purified by such means is white in a solid state, has an extremely sharp melting point, and is suitable as a wax for toner in the present invention. Acid value of 10 after purification
Below, 5 or less is preferable for toner.

The above waxes may be used alone or in combination, and are used in an amount of 0.3 to 4 relative to the polyester resin.
By containing 0 parts by weight, preferably 1 to 30 parts by weight, good fixing offset performance can be obtained. It is more preferably 1 to 20 parts by weight. If it is less than 0.3 parts by weight, the offset resistance is impaired, and if it is more than 40 parts by weight, the fluidity of the toner deteriorates, and in the two-component developing method, the spent carrier is generated by adhering to the carrier surface, This may adversely affect the charging characteristics of the toner, or in the non-magnetic one-component developing system, the toner may adhere to the layer thickness regulating member pressed against the developing roll.

In the present invention, a charge control agent can be used if necessary. For example, as a positive charge control agent, a nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt, a resin containing a quaternary ammonium group and / or an amino group, or the like is used as a negative charge control agent, a trimethylethane dye, or a metal of salicylic acid. Complex salts, metal complex salts of benzylic acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex salts azo dyes, acid dyes containing heavy metals such as azochrome complexes, calixarene type phenolic condensates, cyclic polysaccharides, carboxyl groups And / or resins containing sulfonyl groups.

In particular, when the electrostatic image developing toner of the present invention is used as a color toner, it is desirable to use a colorless charge control agent, and a negative charge control agent is a metal complex compound of salicylic acid, which is orient chemical. "Bontron E-84" manufactured by the same company is also used as a colorless positive charge control agent TP-302, TP-41 having a quaternary ammonium salt structure.
5, TP-610; (Hodogaya Chemical Co., Ltd.), Bontron P-
51; (manufactured by Orient Kagaku), Copy Charge PSY
(Clariant Japan) and the like are preferably used. In addition, as a positively chargeable resin type charge control agent containing a quaternary ammonium group and / or an amino group, “FCA-20
1-PS ”(Fujikura Kasei Co., Ltd.) and the like.

The above charge control agents may be used alone or in combination, and are added to the polyester resin in an amount of 0.3.
-15 parts by weight, preferably 0.5 to 5 parts by weight can provide good charging performance.

In the present invention, a method for producing spherical or substantially spherical toner particles (hereinafter referred to as mother toner) before surface treatment with silicone oil is, for example, required for a polyester resin containing a carboxyl group. Depending on the above, a colorant, a release agent, a charge control agent, etc. are added to produce a mixture, and by mixing it with an aqueous medium in the presence of a base, the mixture is an emulsified resin particle suspension. Is produced, and then the resin particles are separated from the suspension and dried.

A mixture containing a polyester resin containing a carboxyl group and a colorant, a release agent, a charge control agent and the like, which are added as required, can be produced by a known method. For example, these raw material powders are first mixed, and then sufficiently melt-kneaded using any of a twin-screw extruder, a kneader, a two-roll mill, and the like. In such a melt-kneading step, when a high-molecular weight component of the polyester resin is contained, the molecular chain may be broken, so a raw material used by predicting a change in the molecular weight during the kneading of the polyester resin in advance. It is necessary to choose the resin.

As a method of mixing the kneaded product thus produced with an aqueous medium in the presence of a base to emulsify the compound, for example, the kneaded product is emulsified in the aqueous medium under high-speed stirring conditions. Any method can be used. When this step is used, it is necessary to soften the polyester resin and suppress boiling of the aqueous medium, so that it is preferable to manufacture at a high temperature and a high pressure.

The base toner can also be manufactured by a method in which a polyester resin, a colorant and the like are mixed with an organic solvent, and the mixture is wet-kneaded and dispersed to obtain the above mixture. In this case, the colorant and the other additive such as a release agent may be wet-kneaded and then dispersed.

Specifically, a polyester resin is dissolved in an organic solvent, a colorant and the like are added thereto, and a general mixer / disperser such as a despa (dispersion stirrer), a ball mill, a bead mill, a sand mill, and a continuous bead mill is used. Used to disperse and produce a resin solution in which a colorant and a releasing agent are finely dispersed in an organic solvent, and then the resin solution is mixed with an aqueous medium in the presence of a basic neutralizing agent to emulsify. And further removing the organic solvent under reduced pressure to produce a suspension of resin particles. After that, the mother toner can be obtained by separating the resin particles from the suspension and drying the resin particles. According to this manufacturing method, even when the polymer component (gel component) is present in the polyester resin, the molecular chain of the polymer component is not broken, so that the toner is processed through the melt-kneading step of adding a high share to the resin. It is preferable to the manufacturing method.

The polyester resin used for producing the base toner in the present invention is a resin containing a carboxyl group. The polyester resin containing a carboxyl group becomes a self-water-dispersible resin by neutralizing the carboxyl group which is an acidic group. The resin having self-water dispersibility increases hydrophilicity due to the carboxyl group becoming an anion and is dispersed in an aqueous medium (water or a liquid medium containing water as a main component).

The base used for neutralizing the carboxyl group, which is an acidic group, is not particularly limited, and examples thereof include inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia, and diethylamine, triethylamine and isopropylamine. Organic bases are used.

Examples of the organic solvent for dissolving or dispersing the polyester resin, the colorant, and the release agent, which is added as necessary, include pentane, hexane, heptane, and the like.
Hydrocarbons such as benzene, toluene, xylene, cyclohexane, petroleum ether; halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, carbon tetrachloride; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone Kinds; ethyl acetate,
Esters such as butyl acetate are used. These solvents may be used alone or in combination of two or more. The organic solvent is preferably one that dissolves the polyester resin, has a relatively low toxicity, and has a low boiling point that facilitates solvent removal in a later step, and methyl ethyl ketone is most preferable as such a solvent.

A phase inversion accelerator is added when a mixture of the polyester resin, a colorant, etc., which is added as necessary, and an organic solvent is mixed with an aqueous medium in the presence of a base and emulsified. Is preferred. The phase inversion accelerator refers to an agent having a phase inversion promoting function. That is, in the step of adding an aqueous medium (water or a liquid medium containing water as a main component) to a mixture of a polyester resin, a colorant and the like and an organic solvent, gradually add water to the organic continuous phase of the mixture. Then, the discontinuous phase of Water in Oil is generated, and by further adding water, the phase is converted into the discontinuous phase of Oil in Water, and the mixture becomes particles (droplets) in the aqueous medium.
A suspension that floats as is formed. At this time, Water i
n A substance that has the function of facilitating the smooth phase inversion from the discontinuous phase of Oil to the discontinuous phase of Oil in Water is called a phase inversion accelerator.

Since the polyester resin used in the present invention has self-dispersibility in water by being neutralized, it can be dispersed in an aqueous medium without using a phase inversion accelerator. However, in the polyester resin used in the present invention, the use of the phase inversion accelerator facilitates the production of a suitable base toner having an average particle size and a particle size distribution.

The following phase inversion accelerators can be used in the present invention. Alcohol solvent metal salt compound

Examples of the alcohol solvent include methanol, ethanol, isopropanol, n-propanol, isobutanol, n-butanol, t-butanol, sec.
-Butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether and the like can be used. Of course, other types can also be used. Among them, preferred are those which are dissolved in water and have a low boiling point, isopropanol,
N-propanol is preferred. The amount of the alcohol solvent used is generally 10 to 50 per 100 parts by weight of the resin solid content.
Although it is about parts by weight, of course, it is not limited to this amount.

As the metal salt compound, known compounds can be used, but those having a valence of 2 or more and soluble in water are preferable. Examples thereof include barium chloride, calcium chloride, cuprous chloride, cupric chloride, ferrous chloride and ferric chloride. The amount of metal salt compound used is 100 resin solids.
It is about 0.01 to 3 parts by weight per part by weight, but it is not limited to this amount.

Polyester resin, coloring agent, organic solvent,
The method of emulsifying and dispersing the mixture of the basic neutralizing agent and the phase inversion accelerator in the aqueous medium is not limited to a special method.

In the production method of the present invention, a homomixer (Tokushu Kika Kogyo Co., Ltd.), or a slasher (Mitsui Mining Co., Ltd.), Cavitron (Eurotech Co., Ltd.), a microfluidizer (Mizuho Kogyo Co., Ltd.), a Manton-Gaulin homogenizer ( A high shear emulsion disperser such as Gorin Co., Nanomizer (Nanomizer Co., Ltd.), Static Mixer (Noritake Company), a continuous emulsion disperser, etc. can also be used.

However, for example, Japanese Patent Laid-Open No. 9-114
Stirrer, anchor wing, as disclosed in 135;
Turbine blades, Faudler blades, full-zone blades, Maxblend blades, half-moon blades, etc. are used, and the peripheral speed of the stirring blades is 0.2 to 5 m / s, more preferably 0.5 to 4 m / s at a low shear rate. A method of dropping water with stirring is preferable. By performing the phase inversion under such a low shear condition, generation of fine powder can be suppressed, and a base toner having a more preferable uniform particle size distribution can be obtained.

For the suspension of spherical or substantially spherical resin particles obtained by phase inversion, it is preferable to remove the organic solvent by means such as distillation. Then, the suspension of resin particles is subjected to solid-liquid separation by means such as filtration, and the resin particles are dried, whereby a base toner can be obtained.

Further, the suspension of spherical or substantially spherical resin particles obtained by such phase inversion, after removing the organic solvent, is prepared, for example, from hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, oxalic acid, etc. An acid is used to carry out a reverse neutralization treatment for returning the neutralized acidic group hydrophilic group on the surface of the particle to the original functional group to further reduce the hydrophilicity of the particle itself, and then water is removed and filtered. It is preferably dried.

As a drying method, any known and commonly used method can be adopted. For example, a method of drying under normal pressure or reduced pressure at a temperature at which toner particles are not heat-fused or aggregated, a method of freeze-drying, And so on. Further, a method of simultaneously separating and drying the toner particles from the aqueous medium using a spray dryer or the like can be mentioned. In particular, a method of stirring and drying the powder under reduced pressure while heating the toner particles at a temperature at which they are not heat-fused or agglomerated, or a flash jet dryer (Seishin Enterprise Co., Ltd.) that instantaneously dries using a heated drying air stream. Method) is more efficient and preferable.

When classification for removing coarse particles and fine particles is necessary in order to adjust the particle size distribution of the formed base toner, it is carried out by a known and commonly used method using an airflow classifier after completion of drying. be able to. Further, a method of classifying with a centrifuge while the colored resin particles are dispersed in an aqueous medium may be used. The coarse particles can be removed by filtering an aqueous slurry of the colored resin particles with a filter or a wet vibration sieve. The particle size distribution of the toner of the present invention is 50% volume particle size (Dv) measured by Coulter Multisizer.
A / 50% number particle size (Dn) of 1.35 or less, more preferably 1.30 or less is preferable because a good image can be obtained.

The toner for developing an electrostatic charge image of the present invention includes
The volume average particle diameter is preferably in the range of 1 to 15 μm from the viewpoint of the obtained image quality and the like, and 3 to 10 is preferable.
More preferably, it is about μm. In particular, the range of 3 to 7 μm is preferable. When the volume average particle diameter is small, not only the resolution and gradation are improved, but also the thickness of the toner layer for forming a printed image is reduced, and the toner consumption per page is reduced, which is preferable.

As an example of the silicone oil used in the present invention, dimethyl silicone oil is preferable, but so-called modified silicone oil modified with various functional groups depending on the charging property can also be used. Examples of modified silicone oils include alkyl modified silicone oils, methylstyrene or olefin modified silicone oils,
Polyether modified silicone oil, alcohol modified silicone oil, fluorine modified silicone oil, chlorophenyl silicone oil, mercapto modified silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, higher fatty acid modified silicone oil, carnauba modified silicone oil, amide modified silicone oil Etc.

In particular, when the toner for developing an electrostatic image of the present invention is a positively chargeable toner, it is preferable to use a silicone oil containing a nitrogen atom as the silicone oil for treating the surface of the base toner. . Generally, a group containing a nitrogen atom includes an amino group, a nitrile group,
There is a nitro group, an amide group, an imino group, an imide group, etc., and a silicone oil containing a nitrogen atom is one in which any of these groups is bonded to the main chain of the silicone oil or as a main chain constituent component. It has been incorporated into the chain. Among them, the silicone oil containing a nitrogen atom is preferably an amino-modified silicone oil containing an amino group. The following are commercially available products of such silicone oils.

KF-8010, X-22-161A, X
-22-161B, X-22-1660B-3, KF-
8008, KF-8012, KF-393, KF-85
9, KF-860, KF-861, KF-867, KF
-869, KF-880, KF-8002, KF-80
04, KF-8005, KF-858, KF-864,
KF865, KF-868, KF-8003, KF-8
57, KF-862, KF8001 (above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

These silicone oils can be used alone, but in order to adjust the toner characteristics such as electric characteristics and fluidity of the toner to desired levels, two or more kinds of them may be mixed and used. It is possible. The silicone oil used in the present invention preferably has a viscosity at 25 ° C. of 1 to 10,000 centistokes. Further, it is more preferably 10 to 6000 centistokes, and particularly preferably 30 to 3000 centistokes. The viscosity of silicone oil is 1
If it exceeds 0000 centistokes, uneven distribution tends to occur when directly added to the toner, which is not preferable.

In the present invention, the amount of silicone oil attached to the surface of the toner particles is preferably 0.001 to 0.5 part by weight with respect to 100 parts by weight of the toner particles. Further, it is more preferably 0.001 to 0.2 part by weight, and particularly preferably 0.001 to 0.1 part by weight. If the amount of silicone oil is less than 0.001 part by weight, the effect of the present invention cannot be obtained, and if it exceeds 0.5 part by weight, the fluidity is deteriorated, which is not preferable.

In the present invention, as a method for surface-treating the surface of the mother toner with silicone oil, the mother toner to be surface-treated and the silicone oil are put into a powder mixer such as a Henschel mixer, and both are treated. A method of applying the silicone oil to the surface of the toner particles by stirring and mixing, or a method of charging the toner particles in a powder mixer and spraying the silicone oil with a spray while applying the toner particles, etc. There is a method of surface treatment.

Further, in the present invention, various additives (hereinafter referred to as external additives) are attached to the surface of the toner particles in order to improve the fluidity of the toner, improve the charging characteristics, and improve the surface of the toner particles. Is preferred. As a method of attaching the external additive to the surface of the toner particles, the toner particles and the external additive may be put into a powder mixer such as a Henschel mixer and stirred at a high speed.

Examples of the external additive that can be used in the present invention include inorganic fine powders of silicon dioxide, titanium oxide, aluminum oxide, cerium oxide, zinc oxide, tin oxide, zirconium oxide, and the like, and silicone oil and silane cup. Surface treated with hydrophobizing agent such as ring agent, resin fine powder such as polystyrene, acrylic, styrene acrylic, polyester, polyolefin, cellulose, polyurethane, benzoguanamine, melamine, nylon, silicon, phenol, vinylidene fluoride To be

Among these, silicon dioxide (silica) whose surface is hydrophobized with various polyorganosiloxanes, hexamethylenedisilazane, silane coupling agents and the like can be particularly preferably used. As such,
For example, there are products marketed under the following trade names.

AEROSIL R972, R974, R
202, R805, R812, RX200, RY20
0, R809, RX50, RA200HS, RA20
OH [Japan Aerosil Co., Ltd.] WACKER HDK H2000, H1018, H
2050EP, HDKH3050EP, HVK2150
[Wacker Chemicals East Asia Co., Ltd.] Nipsil SS-10, SS-15, SS-2
0, SS-50, SS-60, SS-100, SS-5
0B, SS-50F, SS-10F, SS-40, SS
-70, SS-72F, [Nippon Silica Industry Co., Ltd.] CABOSIL TG820F, TS-530, TS-
720 [Cabot Specialty Chemicals
Ink] The particle diameter of the external additive is preferably 1/3 or less, and particularly preferably 1/10 or less of the diameter of the toner particles. Further, these external additives may be used in combination of two or more kinds having different average particle diameters.

Particularly in the case of non-magnetic one-component developing toner, by using a toner having a large particle diameter and a toner having a small particle diameter in combination, the toner fluidity and the developing durability are improved, and the toner is fixed to the blade of the developing machine. In addition, it is preferable because the prevention of fogging and the long-term stability of charging during running can be obtained. The proportion of the external additive used is 0.
It is from 05 to 5% by weight, preferably from 0.1 to 3% by weight.

The electrostatic image developing toner of the present invention can be produced by coating the surface of the toner particles with silicone oil as described above and then adhering the external additive to the surface of the toner particles. It is better to reverse the order of the step of applying silicone oil and the step of attaching the external additive, and perform the production in the order of attaching the external additive to the surface of the toner particles and then applying the silicone oil containing a nitrogen atom. More preferable. By doing so, the surface of the toner particles and the surface of the particles of the external additive are coated with silicone oil having the same chemical composition, and the charging characteristics are more stable.

The toner for developing an electrostatic image of the present invention can be used as a one-component developer, a non-magnetic one-component developer or a two-component developer mixed with a carrier for developing an electrostatic latent image by electrophotography. . The type of carrier is not particularly limited, and known and commonly used iron powder, ferrite, magnetite, or the like, or a carrier coated with a resin thereof can be used.

The electrostatic image developing toner of the present invention surface-treated with silicone oil exhibits stable charging performance.
In particular, when it is mixed with a carrier and used as a developer for initial charging, a stable image can be obtained for a long period of time, such that it has excellent charge rising characteristics and can significantly reduce fog in the initial printing stage. Such a developer using the toner for developing an electrostatic image of the present invention is suitable for an image forming method for high-speed printing, particularly for high-speed printing exceeding 20 m / min, and further exceeding 30 m / min. There is. The developer exhibits stable development performance and transfer performance without fluctuation in triboelectrification performance and electric resistance even in high-speed printing.

[0091]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition,
In the examples and comparative examples, unless otherwise indicated, parts are parts by weight and water is deionized water.

(Example of polyester resin synthesis) As divalent carboxylic acid, terephthalic acid (TPA) and isophthalic acid (IP
A), polyoxypropylene (2.4) -2,2-bis (4-hydroxyphenyl) as an aromatic diol
Propane (BPA-PO), polyoxyethylene (2.
4) -2,2-bis (4-hydroxyphenyl) propane (BPA-EO) and ethylene glycol (EG) as an aliphatic diol were used in each molar composition ratio shown in Table 1,
Tetrabutyl titanate as a polymerization catalyst was charged into a separable fresco at 0.3% by weight with respect to the total amount of monomers, and a thermometer, a stirring rod, a condenser and a nitrogen inlet tube were attached to the upper part of the flask in an electric heating mantle heater under normal pressure nitrogen. After reacting at 220 ° C. for 15 hours under an air stream, the pressure was sequentially reduced and the reaction was continued at 10 mmHg. The reaction is ASTM
Followed by the softening point according to E28-517, when the softening point reached a predetermined temperature, the vacuum was stopped to terminate the reaction. Table 1 shows the composition and physical property values (characteristic values) of the synthesized resin.

[0093]

[Table 1] >600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less TPA; terephthalic acid IPA; isophthalic acid BPA-PO; polyoxypropylene (2.4) -2,
2-bis (4-hydroxyphenyl) propane BPA-EO; polyoxyethylene (2.4) -2,2
-Bis (4-hydroxyphenyl) propane EG; ethylene glycol BA: benzoic acid TMP; trimethylolpropane FT value; flow tester value

In Table 1, "T1 / 2 temperature" means the flow tester (CFT-50 manufactured by Shimadzu Corporation) as described above.
No. 0), the nozzle diameter is 1.0 mmΦ × 1.0 mm, the load per unit area (cm ² ) is 10 kg, and the heating rate is 6 ° C./min. Further, the glass transition temperature “Tg” (° C.) was 1 per minute by the second run method using a differential scanning calorimeter (DSC-50) manufactured by Shimadzu Corporation.
It is a value measured at a heating rate of 0 ° C.

(Preparation Example of Release Agent Dispersion) Carnauba Wax "Carnauba Wax No. 1" (Imported by Kato Yoko) 50
Parts and 50 parts of polyester resin (R1 in Table 1) were kneaded with a pressure kneader, and then the kneaded product and methyl ethyl ketone 185
Parts were placed in a ball mill, stirred for 6 hours, then taken out, the solid content was adjusted to 20% by weight, and a fine dispersion liquid (W1) of a release agent was obtained. Polyester resin R in the same way
2 and R3 (in Table 1) were used to obtain respective dispersions (W2) and (W3) of the release agent. The prepared release agent dispersion is shown in Table 2.

[0096]

[Table 2]

(Preparation Example of Colorant Dispersion) Carbon black “ELFTEX-8” (manufactured by Cabot Corporation) and a resin having the composition shown in Table 3 were kneaded at a weight ratio of 50/50 to obtain colorant master chips P1 to P3. It was made. The carbon black and the resin were kneaded using a pressure kneader.

[0098]

[Table 3] The colorants shown in Table 3 are as follows. Carbon: "ELFTEX-8" (manufactured by Cabot)

(Adjustment of Wet-Kneading Mill Base) The above releasing agent dispersion, colorant master chip, diluting resin (additional resin) and methyl ethyl ketone were mixed with a despar to adjust the solid content to 55%, and the mill base (MB1 ~ MB
4) was produced. Table 4 shows the composition of the produced mill base.

[0100]

[Table 4]

The characteristics of the blend resin used in Table 4 are shown in Table 5
It was shown to. The resin blending was carried out by blending resin particles having passed through 200 mesh at the above weight ratio and measuring the respective physical properties.

[0102]

[Table 5]

(Example 1) In a cylindrical separable flask having a stirrer, 545 parts of Millbase MB1, 32 parts of methyl ethyl ketone, 27 parts of isopropyl alcohol,
After 12.4 parts of 1N ammonia water was added and sufficiently stirred, 160 parts of deionized water was added and further stirred to adjust the temperature to 30 ° C. Then, 70 parts of deionized water was added dropwise to carry out phase inversion emulsification. After stirring for 30 minutes,
The spin was stopped and 500 parts of water were added.

Next, the solvent was removed by distillation under reduced pressure, and filtration and washing with water were performed. Subsequently, the obtained wet cake was redispersed in water, 1N aqueous hydrochloric acid solution was added until the pH of the dispersion became about 4, and then filtration and washing were repeated. The wet cake thus obtained was freeze-dried and then classified using an airflow classifier to obtain toner particles having a volume average of 7.5 μm and an average circularity of 0.985.

Then, to 100 parts of the obtained toner particles, 1.0 part of hydrophobic silica (H-2018 manufactured by Clariant Co., Ltd.) and titanium oxide (JMT-150AO manufactured by Teika Co., Ltd.) were used using a Henschel mixer. Mix 0.5 parts each and then add dimethyl silicone oil (K
F-96-50CS) (manufactured by Shin-Etsu Chemical Co., Ltd., viscosity: 50 centistokes) 0.005 part, and further mixed with a Henschel mixer, and then passed through a sieve to obtain powder toner (toner for developing electrostatic image). Obtained.

Example 2 Instead of the dimethyl silicone oil (KF-96-50CS) used in Example 1, methylphenyl silicone oil (SH510) (manufactured by Toray Dow Corning Co., Ltd., viscosity 100 centistokes) 0 A toner was prepared in the same manner as in Example 1 except that 0.01 part was used to obtain a powder toner (electrostatic charge developing toner).

Example 3 Toner particles having a volume average of 7.5 μm and an average circularity of 0.985 were obtained in the same manner as in Example 1 except that MB2 was used in place of the millbase MB1.

Then, in the same manner as in Example 1, hydrophobic silica and titanium oxide were adhered to the surface of the toner particles,
Then, it was applied onto the surface of the dimethyl silicone oil toner particles. Further, a powder toner (toner for developing electrostatic image) was obtained through a sieve.

Example 4 Toner particles having a volume average of 7.6 μm and an average circularity of 0.983 were obtained in the same manner as in Example 1 except that MB3 was used instead of the mill base MB1.

Then, in the same manner as in Example 1, hydrophobic silica and titanium oxide were adhered to the surface of the toner particles,
Then, it was applied onto the surface of the dimethyl silicone oil toner particles. Further, a powder toner (toner for developing electrostatic image) was obtained through a sieve.

Example 5 Toner particles having a volume average of 7.4 μm and an average circularity of 0.984 were obtained in the same manner as in Example 1 except that MB4 was used instead of the millbase MB1.

Then, in the same manner as in Example 1, hydrophobic silica and titanium oxide were adhered to the surfaces of the toner particles,
Then, it was applied onto the surface of the dimethyl silicone oil toner particles. Further, a powder toner (toner for developing electrostatic image) was obtained through a sieve.

Comparative Example 1 A toner was prepared in the same manner as in Example 1 except that dimethyl silicone oil (KF-96-50CS) (produced by Shin-Etsu Chemical Co., Ltd., viscosity: 50 centistokes) was not used. , Powder toner (toner for developing electrostatic image) was obtained.

(Comparative Example 2) Resin R1 (Table 1) 29.6
Parts, resin R3 (Table 1) 53.4 parts, colorant master chip P1 (Table 3) 12 parts, and carnauba wax 5 parts were mixed with a Henschel mixer, and then melt-kneaded with a biaxial extrusion kneader. The kneaded product is cooled to room temperature, roughly crushed with a hammer mill, finely pulverized with a jet mill, and then classified with an air classifier to obtain a toner having a volume average of 7.5 μm and an average circularity of 0.960 by a pulverization method. It was

Then, to 100 parts of the obtained toner particles, 1.0 part of hydrophobic silica (H-2018 manufactured by Clariant Co., Ltd.) and titanium oxide (JMT-150AO manufactured by Teika Co., Ltd.) were used using a Henschel mixer. Mix 0.5 parts each and then add dimethyl silicone oil (K
F-96-50CS) (manufactured by Shin-Etsu Chemical Co., Ltd., viscosity: 50 centistokes) 0.005 part, and further mixed with a Henschel mixer, and then passed through a sieve to obtain powder toner (toner for developing electrostatic image). Obtained.

The following tests were conducted using the toners produced in Examples 1-5 and Comparative Examples 1-2. (1) Measurement of charge amount The charge amount was measured by Examples 1 to 5 and Comparative Example 1 to which external addition was performed.
2 toner and a silicone resin-coated ferrite carrier (particle size 90 μm) were mixed in a ratio of 3/97 to prepare a developer,
After stirring for 5 minutes, 10 minutes, 30 minutes, and 60 minutes with a ball mill, the charge amount and the reverse charge amount of the toner are measured using an E-spurt analyzer, which is a charge amount distribution measuring device, and the toner charge is different depending on the stirring time. The rising property of the amount was evaluated. Table 6 shows the obtained evaluation results. Measurement conditions of E-Spurt analyzer Blow pressure: 0.02 MPa Measurement count: 3000 Potential difference between electrodes: 100 V

(2) Printing characteristics Using the developer used for the above-mentioned measurement of the amount of charge, an image output test was conducted with a two-component developing type copying machine every time the above stirring time passed, and fog and transfer efficiency were examined. Was evaluated respectively. Table 6 shows the obtained evaluation results. Regarding fog,
Images were visually evaluated using the test patterns. As for the evaluation results, "○" is slightly better than the standard, "◎" is even better,
Expressed as The transfer efficiency is shown by the value obtained by the transfer efficiency measuring method described below.

(3) Transfer efficiency measuring method A solid image (length 100 mm × width 20 mm) was developed using a commercially available two-component developing type copying machine, and the solid image on the photoconductor passed 50% through the transfer portion. By the way, stop the machine. After that, among the solid images formed on the photoconductor, the solid image portion that has not yet passed through the transfer portion (toner before transfer) and the toner that remains on the solid image portion that has already passed through the transfer portion (transfer residual toner). ) Each tape (30
(mm × 20 mm), the toner weight before transfer and the weight of the transfer residual toner were measured, and the transfer efficiency (%) was calculated from the following formula. Table 7 shows the obtained evaluation results. Transfer efficiency = 100− (weight of toner after transfer / weight of toner before transfer) × 100

(4) Fixing Property Test Regarding the fixing temperature range, the fixing temperature was determined by the following fixing property test, and the range between the upper limit value and the lower limit value was defined as the fixing temperature range. Using each powder toner of Examples and Comparative Examples,
A test sample in which an unfixed image was formed on paper was prepared by using a commercially available two-component development type copier remodeling machine, and the test sample was prepared at a speed of 90 mm / sec and RICOH IMAGIO DA-25.
Fix through a 0 heat roll (oilless type), attach an adhesive tape to the fixed image, and peel off the ID
The surface temperature range of the heat roll when the (image density) is 90% or more of the original ID and the occurrence of offset is not observed is defined as "fixing temperature range". The results are shown in Table 7.

[0120]

[Table 6] Charge amount: Unit μC / g Reverse charge amount: Number of positively charged toner particles%

[0121]

[Table 7]

As can be seen from the evaluation results of Tables 6 and 7,
In Examples 1 to 5, the charge amount rises quickly and reaches saturation, and it is understood that the charge stability is excellent. In addition, the image shows no fog even in the initial stage of stirring (5 min.).
An image with good gradation and resolution is obtained. on the other hand,
In Comparative Example 1, the rising property of the charge amount was poor, and the stirring time was 5 m.
At 10 min., there was image fog and a good image could not be obtained. Further, in Comparative Example 2, the charge rising property is good and there is no image fog, but the transfer efficiency is poor because the toner shape is irregular. Further, the print image was inferior in gradation and resolution as compared with the toner of the example.

[0123]

According to the toner of the present invention, long-term use,
Or to provide a toner for developing an electrostatic charge image, which shows stable charging behavior even in multi-copy printing, has little fog, does not change image density, and can obtain a printed image excellent in gradation and resolution. You can In addition, it is possible to provide a toner for developing an electrostatic image having a high transfer rate from a photoconductor to a printing material such as paper during development.

[Brief description of drawings]

FIG. 1 is a diagram for explaining how to obtain a flow tester value, in which (a) is a side sectional view showing an outline of a measuring device,
(B) is a graph for explaining a method of obtaining each flow tester value from the measured value.

Claims (5)

[Claims] 1. A toner for developing an electrostatic charge image, which comprises a polyester resin as a binder resin and has an average circularity of 0.97 or more, wherein the surface of the toner is treated with silicone oil. Toner for developing electrostatic images. 2. The acid value of the polyester resin is 3 to 20.
The toner for developing an electrostatic charge image according to claim 1, which is 3. The polyester resin contains a crosslinked polyester resin, and the toner has a T1 / 2 temperature of 120 ° C. to 180 ° C. measured by a constant load extrusion type capillary rheometer.
The toner for developing an electrostatic charge image according to claim 1, which is 4. The polyester resin (1) has a T1 / 2 temperature of 8 by a constant load extrusion type capillary rheometer.
Linear or branched polyester resin (A) having a temperature of 0 ° C. or higher and lower than 120 ° C., (2) T1 / 2 temperature of 120 ° C. or higher, measured by a constant load extrusion type capillary rheometer, 21
It contains a cross-linked or branched polyester resin (B) at 0 ° C. or lower, and the weight ratio of the polyester resin (A) and the polyester resin (B) is (A) / (B) = 20/8.
0 to 80/20 and the T1 / 2 temperature is T1 /
2. The toner for developing an electrostatic charge image according to claim 1, which has a relationship of 20 ° C. <T1 / 2 (B) −T1 / 2 (A) <100 ° C., where 2 (A) and T1 / 2 (B). 5. The viscosity of the silicone oil is 25 ° C.
The toner for electrostatic charge development according to claim 1, which has a viscosity of 1 to 10000 centistokes.