JPH0659502A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To provide a toner excellent in transparency and color reproducibility which can be used for oilless fixing with Teflon rollers and causes no filming to a photosensitive body or developing sleeves. CONSTITUTION:The toner has >=10<4>dyne/cm<2> storage elasticity modulus G' and loss elasticity modulus G'' at 150 deg.C, and 0.1 to 5X10<3> pa-sec apparent viscosity. The obtd. toner has excellent transparency and color reproducibility and can be applied for oilless fixing with Tefon rollers. The toner causes no filming to a photosensitive body or developing sleeves.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has translucency and
The present invention relates to a toner excellent in oilless fixing property.
The present invention also relates to a toner that does not cause filming on the photoconductor, the developing sleeve, and the like.

[0002]

2. Description of the Related Art Although there are color copying machines on the market which use electrophotographic technology, they are required to have color reproducibility, gloss and transparency of images and to have stable fixing quality without offset phenomenon. Silicone roller fixing, which applies oil, is the mainstream. In fixing the silicone roller, there is a problem that the device is large because an oil application device or the like is required, the power consumption is large, the user needs to replenish the silicone oil, and the image storability is poor. In some cases, an oilless color system using a toner containing a Teflon roller and a release agent is also on the market, but its use is limited to the range of color by color because of poor color reproducibility and transparency. Further, the color reproducibility on the screen when OHP is used is extremely poor. Further, regarding filming for a photoconductor, a developing sleeve, etc., a method of improving strength and heat resistance of a binder resin and improving dispersibility of a release agent and a polarity control agent is known as a means for preventing it. There is a problem that fixing failure occurs if the above is performed, and if the above is also performed, the toner image is transferred to a part of the fixing roll and other members, and this is transferred to the next copy paper substrate. There was a problem such as a phenomenon.

[0003]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned technical background, and its object is excellent in translucency and color reproducibility, and is suitable for Teflon roller fixing without oil. To provide a toner that can be used.
Another object is to provide a toner that does not cause filming on the photoconductor, the developing sleeve, and the like.

[0004]

As a result of repeated studies on the rheological properties of the toner, the present inventors have found that the storage elastic modulus G'at 150 ° C. and the loss elastic modulus G "are 10 ⁴ dy, respectively.
ne / cm ² or more and an apparent viscosity of 0.1 to 5 × 10 ³ Pa ・ s
If there is a condition of being ec, it is excellent in translucency and color reproduction,
In addition, it is concluded that a toner that is oilless and that can be applied to Teflon roller fixing can be obtained, and that a toner that does not cause filming on the photoreceptor and the developing sleeve can be obtained. If the storage modulus G ′ and the loss modulus G ″ of the toner are smaller than 10 ⁴ dyne / cm ^2, respectively,
There is no offset resistance effect. Further, if the apparent viscosity of the toner is smaller than 0.1 Pa · sec, the effect of offset resistance cannot be seen. Also, the apparent viscosity of the toner is 5 × 10 ³ Pa.
-If it is larger than sec, although there is an effect of anti-offset, there is a tendency that the fixing property at low temperature is deteriorated or the translucency is deteriorated. Here, the measuring method of the present invention will be described.

(1) Measurement of storage elastic modulus (G ') and loss elastic modulus (G ") To measure the dynamic viscoelasticity of the toner of the present invention, (US) REOM
A Rheometrics Dynamic Spectrometer RDS-7700 model rheometer manufactured by ETRICS, INC was used. The measurement conditions were fixed at frequency ω = 10 rad / sec and the distortion rate was automatic. Under this condition, the temperature was raised from 100 ° C to 200 ° C and the temperature dependence measurement was performed. From this measurement result, the storage elastic modulus (G ') and the loss elastic modulus (G ") at 150 ° C. were obtained, and these were calculated as G'for the temperature of the sample,
G ”.

(2) Measurement of Apparent Viscosity To measure the apparent viscosity of the toner of the present invention, a high performance type flow tester CFT-500C manufactured by Shimadzu Corporation was used. As the measurement conditions, a nozzle with a diameter x length = 0.5 x 1 mm and a plunger with a cross-sectional area = 1 cm ² were used, and the load = 10
kg, temperature rising rate = 3 ° C./min, residual heat time = 200 sec, start temperature = 70 ° C. Measurement is performed under these conditions, and the temperature
Obtain the apparent viscosity curve. 150 from the obtained smooth curve
The apparent viscosity at 0 ° C. was determined and used as the apparent viscosity for the sample. Next, the materials used in the present invention will be described.

As the binder resin used in the present invention, those which have been used as the binder resin for the toner can be applied. Therefore, the binder resin has relatively heat resistance and strength in consideration of storage stability and the like. Is preferred. Specifically, polystyrene, polychloroethylene, a homopolymer of styrene such as polyvinyltoluene, or a substitution product thereof; a styrene-P-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, Styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer Polymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene -Vinyl ethyl ether copolymer, Ethylene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer and the like Styrenic copolymers; polymethylmethacrylate, polybutylmethacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene,
Polyester, polyvinyl butyl butyral polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. May be used alone or in admixture of two or more, but in the present invention, the softening point is 95 ° C.
The above is preferable. The softening point of the melt-kneaded binder is
When the temperature is 95 ° C. or less, the storage elastic modulus G ′ and the loss elastic modulus G ″ at 150 ° C. of the toner obtained by melt-kneading with a colorant and a release agent are 10 ⁴ dyne / cm ² or more, and It is extremely difficult to obtain the condition that the apparent viscosity is 0.1 to 5 × 10 ³ Pa · sec.

The pigments and dyes used in the present invention are
All conventionally used pigments and dyes can be applied. Specifically, ultramarine, nigrosine dye, aniline blue, chalco oil blue, Victoria blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, rhodamine 6G lake, quinacridone, benzidine yellow, malachite green, hansa yellow. G, malachite green hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments,
Examples include disazo dyes and pigments and trisazo dyes and pigments.

As the polarity control agent, a nigrosine type dye,
Examples thereof include quaternary ammonium salts, basic dyes, polymers having an amino group, chromium-containing azo dyes, and metal salts of salicylic acid derivatives.

Examples of the releasing agent include synthetic waxes such as low molecular weight polyethylene and polypropylene, plant waxes such as candelilla wax, carnauba wax, rice wax, wood wax and jojoba oil, beeswax, lanolin, Animal waxes such as whale wax, montan wax, mineral waxes such as ozokerite, hydrogenated castor oil, hydroxystearic acid, fatty acid amide,
Examples thereof include oil-based waxes such as phenol fatty acid ester. In addition to the above-mentioned components, the toner of the present invention contains various plasticizers (dibutyl phthalate, dioctyl phthalate, etc.), electric charge, etc. for the purpose of adjusting the thermal properties, electrical properties, physical properties, etc. of the toner as necessary. It is also possible to add auxiliary agents such as resistance adjusting agents (tin oxide, lead oxide, antimony oxide, etc.).

If desired, the toner of the present invention may be mixed with additives other than the above-mentioned toner resin and colorant. Examples of the additive include a fluidizing agent such as colloidal silica, titanium oxide, and aluminum oxide.

[0012]

The present invention will be described in more detail with reference to the following examples. In addition, a part represents a weight part. Example 1 A toner was prepared with the following formulation. Cyan Binder resin Polyester polymer 97 parts (Softening point 97 ° C) Release agent Low molecular weight polypropylene 3 parts Colorant Phthalocyanine blue 2 parts Charge control agent Zinc salicylate 2 parts Magenta Binder resin Polyester polymer 97 parts (Softening Release point 97 ° C) Release agent Low molecular weight polypropylene 3 parts Colorant thioindigo pigment 2 parts Charge control agent Zinc salicylate 2 parts Yellow Binder resin Polyester polymer 97 parts (Softening point 97 ° C) Release agent Low molecular weight polypropylene 3 Parts colorant monoazo yellow 5 parts charge control agent zinc salicylate 2 parts The mixture having the above composition was melt-kneaded using a three-roll mill. After cooling, coarse pulverization was performed using a hammer mill, and then fine pulverization was performed using an air jet type fine pulverizer. The resulting finely pulverized product was classified to have an average particle size of 11 μm. 0.2 part of colloidal silica was added to 100 parts of the present particles and mixed to obtain a toner. The rheological properties of each toner are shown in Table 1.

[0013]

[Table 1]

When each of these toners was put in Myricopy M5 manufactured by Ricoh Company and reverse development was performed and an image was produced, a vivid color tone and good color reproducibility on the screen when OHP was used were obtained. It was Further, after running 10,000 sheets, filming and sticking were not observed on the photoreceptor, the developing sleeve and the blade, and a good image was maintained.

Next, the overlapping development will be described. FIG. 1 shows an example of an overall configuration diagram for obtaining a color image by superposition. Here, 11 is an organic photoconductor, 12 is a corona charger, 13 is a laser optical system, 14, 15 and 16 are developing units containing toners of yellow, magenta and cyan, respectively 17
Is a transfer member, and 18 is a cleaning member. An image was formed using this apparatus by the method described below. Photoconductor 11 (While rotating a diameter of 150 mm in the direction of the arrow at a peripheral speed of 94 mm / sec, the charging member 12 charges the photoconductor 11 to −850 V. Next, the laser optical system 13 charges the non-image area −850 V and the image area −. An electrostatic latent image of 100 V is formed, and a laser beam spot diameter controlled in 8 steps by a pulse width modulation method was used to form this electrostatic latent image. Gap 100μm, development bias -750V
Developed with a yellow developing device
Subsequently, in order to develop a magenta color on 11, the charging member 12 was charged again to -850 V, and an electrostatic latent image was formed by the laser optical system 10. This electrostatic latent image is a development gap of 100 μm,
It was developed by a magenta developing device with a developing bias of -750V. Finally, cyan development was carried out as described above.
However, optical writing to the portion where the magenta toner overlaps the yellow toner portion is avoided in advance by image processing.

As described above, the toner image in which at least two colors are superposed on the photoconductor 11 is transferred onto the transfer paper by the transfer member 17,
After fixing, not only the yellow, magenta, and cyan single-color portions, but also the mixed red, green, and blue mixed-color portions can obtain finely detailed images with good gradation reproducibility according to the toner adhesion amount. And the color reproducibility on the screen was good when the OHP was used.

Comparative Example 1 A mixture having the same composition as in Example was melt-kneaded by using two rolls. After cooling, coarse pulverization was performed using a hammer mill, and then fine pulverization was performed using an air jet type fine pulverizer. The resulting finely pulverized product was classified to have an average particle size of 11 μm. Main particle 1
0.2 parts of colloidal deer was added to and mixed with 00 parts to obtain a toner. Here, the rheological characteristics of each toner are shown in Table 2.
Shown in.

[0018]

[Table 2] When images were formed from these toners in the same manner as in Example 1, the color reproducibility was poor.

Comparative Example 2 Cyan Binder Resin Polyester Polymer 97 Parts (Softening Point 81 ° C.) Release Agent Low Molecular Weight Polypropylene 3 Parts Colorant Phthalocyanine Blue 2 Parts Charge Control Agent Zinc Salicylate 2 Parts Magenta Binder Resin Polyester Polymer 97 parts (softening point 81 ° C) Release agent Low molecular weight polypropylene 3 parts Coloring agent thioindigo pigment 3 parts Charge control agent Zinc salicylate 2 parts Yellow Binder resin Polyester polymer 97 parts (softening point 81 ° C) Release Molding agent Low molecular weight polypropylene 3 parts Coloring agent Monoazo yellow 5 parts Charge control agent Zinc salicylate 2 parts The mixture of the above composition is melt-kneaded using a three-roll, cooled and coarsely crushed using a hammer mill, then air jet method It was pulverized with a pulverizer according to. The resulting finely pulverized product was classified to have an average particle size of 11 μm. 0.2 part of colloidal silica was added to 100 parts of the present particles and mixed to obtain a toner. Table 3 shows the rheological characteristics of each toner.

[0020]

[Table 3] When images were formed from these toners in the same manner as in Example 1, offset development occurred.

Comparative Example 3 A mixture having the same composition as in Comparative Example 2 was melt-kneaded using a two-roll mill. After cooling, coarse pulverization was performed using a hammer mill, and then fine pulverization was performed using an air jet type fine pulverizer. The resulting finely pulverized product was classified to have an average particle size of 11 μm. 0.2 part of colloidal silica was added to 100 parts of the present particles and mixed to obtain a toner. Table 4 shows the rheological characteristics of each toner.

[0022]

[Table 4] When an image was formed on these toners in the same manner as in Example 1, the color tone was vivid, but the color reproducibility on the screen when OHP was used was poor and it was dark. Further, after running 10,000 sheets, filming was slightly generated on the photoconductor, the developing sleeve, and the blade, and a slight background stain was observed. Further, when the toners were superposed in the same manner as in the example, the gradation reproducibility corresponding to the toner adhesion amount in the mixed color portion was not obtained, and the OH
The color reproducibility on the screen when P was used was also poor.

In addition to the above-mentioned YMC, a practical full-color image can be obtained by using the developing device 19 for the black toner of the fourth color and performing so-called black-inking on the portion where the three YMC colors originally overlap.

[0024]

According to the present invention, it is possible to obtain a toner which is excellent in translucency and color reproducibility and can be applied to a Teflon roller without oil. Further, it was possible to obtain a toner that does not cause filming on the photoconductor, the developing sleeve, and the like.

[Brief description of drawings]

FIG. 1 is an example of a configuration diagram for obtaining a color image by superposition using the toner according to the present invention.

[Explanation of symbols]

11 Organic Photoreceptor 12 Corona Charger 13 Laser Optical System 14, 15, 16, 19 Developing Device Containing Yellow, Magenta, Cyan, and Black Toner 17 Transfer Member 18 Cleaning Member 20 Developing Roller 30 Toner Charging Member 40 , 50 Toner stirring operation member

Claims (2)

[Claims] 1. A toner comprising at least a binder resin, a colorant, and a releasing agent, wherein the toner has a storage elastic modulus G ′ at 150 ° C. and a loss elastic modulus G ″ of 1 × 10 5.
⁴ dyne / cm ² or more and an apparent viscosity of 0.1 to 5 × 10 ³
A toner for electrostatic charge development characterized by being Pa · sec. 2. The electrostatic charge according to claim 1, wherein the toner comprising at least a binder resin, a colorant, and a release agent has a binder softening point of 95 ° C. or higher before melt kneading. Toner for development.