JPH10312087A - Dry electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic toner which enables formation of images with excellent color reproducibility and stable gloss without irregularity even when a simple oil-coating fixing device such as an oil roller and an oil coating felt is used. SOLUTION: This dry electrophotographic toner contains at least a coloring agent, a release agent and a binder resin. The binder resin is a polyol resin which is synthesized by the reaction of (a) an epoxy resin, (b) a dihydric phenol, and (c) an alkylene oxide adduct of a dihydric phenol or its glycidylether and which has a polyoxyalkylene part in the main chain and has 4 to 10 Mw/Mn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry electrophotographic toner. More specifically, the present invention relates to a toner suitable for a full-color image forming apparatus which does not require a large fixing device including a silicon oil tank and a circulation device.

[0002]

2. Description of the Related Art In dry electrophotography, an electrostatic latent image is formed on a photoreceptor, developed with dry toner, the toner image is transferred onto copy paper, and then heat-fixed (usually using a heat roller) to copy. It has gained. Particularly, in order to obtain a full-color image, a binder resin such as that described in JP-A-7-77832 has been used because image gloss and good color development are required. In order to obtain good color development, a large fixing device such as a silicon oil tank and a circulation device was required. On the other hand, there is a color system using a simple fixing device, but the characteristics of the toner suitable for it have not been sufficiently studied, and the conventional toner still has to be used. The fact is that it has not been done.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color toner having the following characteristics by using a simple oil application fixing device such as an oil roller or an oil application felt. First, to provide a toner capable of obtaining a glossy and clear image of a color. Second, to provide a toner having a wide fixing temperature range to provide a stable glossy image. A fourth object is to provide a toner that can provide an image without unevenness, a fourth object is to provide a toner having good storability, and a fifth object is to provide a toner having good manufacturability. In general, it is said that if the average glossiness of a printed portion is 5 or more, and preferably 10 or more, gloss and a clear color tone can be obtained. If the fixing temperature width is wide, it is possible to obtain a good image which is not affected by environmental characteristics and an image in which gloss does not fluctuate during continuous printing. The fixing temperature range is about 30 ° C if possible,
At least 10 ° C is required. That no gloss unevenness occurs means, for example, a state in which a high glossiness is present only at the image front end, or a state in which an image has a partially lower gloss portion than the surroundings. The storability is a condition under which the toner does not harden when stored as a toner at a high temperature, and is substituted by the penetration. Good manufacturability means that, for example, there is no possibility that a side reaction occurs during the production and the target product cannot be obtained. Furthermore, it means that sensitization does not affect the health and safety of workers.

[0004]

According to the present invention, there is provided a dry electrophotographic toner containing at least a colorant, a release agent and a binder resin, wherein the binder resin is an epoxy resin (a) or a dihydric phenol (b). ) And a polyol resin having a polyoxyalkylene moiety in the main chain and having a Mw / Mn of 4 to 10, which is synthesized by reacting an alkylene oxide adduct of a dihydric phenol or its glycidyl ether (c). By providing the dry toner for electrophotography described above, a toner having a gloss and a clear color image which is the first problem was obtained.

[0005] The polyol resin used in the present invention is:
Refers to a polyether polyol resin having an epoxy skeleton. When Mw / Mn showing the molecular weight distribution is smaller than 4, offset tends to occur in a simple oil application type fixing device such as an oil roller or an oil application felt, and a fixing temperature range cannot be substantially obtained. Mw / Mn is from 4 to 10, more preferably from 5 to 8, since sufficient image gloss and coloring cannot be obtained and the desired effects of the present invention cannot be achieved. By having a polyoxyarylene moiety in the main chain, the appearance of gloss is improved. The identification of the polyoxyalkylene part of the main chain was performed by NMR. The method for producing the polyol resin of the present invention is as follows.

The epoxy resin (a) used for producing the polyol resin includes, for example, those obtained by subjecting bisphenol A or bisphenol to an epichlorohydrin resin by a condensation reaction. In particular, at least two or more kinds of bisphenol A having different number average molecular weights
By synthesizing a polyol resin using a type epoxy resin, an appropriate molecular weight distribution can be obtained, and a toner having a wide fixing temperature range, which is the second object of the present invention, and a stable gloss image can be provided. In this case, the number average molecular weight of the low molecular weight component is preferably from 360 to 2,000, and the number average molecular weight of the high molecular weight component is preferably from 3,000 to 10,000. Examples of the dihydric phenol (b) include bisphenols such as bisphenol A and bisphenol F.

Further, examples of the alkylene oxide adduct of dihydric phenol as the component (c) used in the synthesis of the polyol resin include the following. For example, a reaction product of an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, and a mixture thereof with a bisphenol such as bisphenol A or bisphenol F may be used. The obtained adduct may be further glycidylated with epichlorohydrin or β-methylepichlorohydrin.

If the polyol resin contains the alkylene oxide adduct of dihydric phenol (c) or the glycidyl ether thereof in the polyol resin in an amount of 10 to 50% by weight based on the epoxy resin of the component (a), The first object of the present invention is to obtain a toner having a glossy and clear image with a clear color, and the second object is to provide a toner having a wide fixing temperature range to provide a stable glossy image. An image without gloss unevenness, which is the third problem, can be obtained. If the amount is less than 10% by weight, the added effect cannot be obtained, and 50% by weight.
If the amount is larger than the above range, the gloss tends to be too high, and in some cases, the storage stability is deteriorated, which tends to have an adverse effect. When the amount of the glycidyl ether in the polyol is small, a problem such as an increase in curl occurs, and, when the amount is too large, the gloss is too high,
Furthermore, there is a possibility that storage stability may be deteriorated. In particular, a diglycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (1) is preferable.

[0009]

Embedded image [Before wherein, R represents _{-CH 2 -CH 2 -, - CH} 2 -CH (C
_{H 3) -, - CH 2} -CH 2 -CH 2 - it is. n and m are each 1 or more, and n + m = 2 to 8. When n + m exceeds 8, there is a possibility that the gloss becomes too high or the storage stability deteriorates. (A), (b)
And the ratio of component (c) is 25 to 70 parts by weight,
Preferred are -40 and 15-40 parts by weight.

Further, if the polyol resin does not have an epoxy group and has an epoxy value of 20,000 or more, it is excellent in sensitization and stability during production. Specifically, the terminal epoxy group may be further reacted with a monohydric phenol or an excess of a dihydric phenol. The following are examples of the monohydric phenols that can be reacted with the epoxy group. Phenol, cresol, isopropylphenol, amylphenol, nonylphenol, dodecylphenol, xylenol, p
-Cumylphenol and the like. Examples of the dihydric phenol include bisphenols such as bisphenol A and bisphenol F. Further, if the softening point of the polyol resin is in the range of 115 to 130 ° C., the second object of the present invention is to provide a toner having a wide fixing temperature range,
An image with stable gloss can be provided. If the temperature is lower than 115 ° C., it is difficult to obtain a sufficient fixing temperature range, and if it is higher than 130 ° C., it tends to cause a problem that sufficient image gloss cannot be obtained.

Further, if 10 to 40 parts by weight of an alkylene oxide adduct of dihydric phenol or glycidyl ether (c) thereof is synthesized with respect to 100 parts by weight of the polyol resin from which the polyol resin is synthesized, The first problem is to obtain a toner capable of obtaining a glossy and clear color image, and the second problem is to provide a toner having a wide fixing temperature range, to provide a stable gloss image, and the third problem. Is obtained. If the amount is less than 10 parts by weight, a problem such as an increase in curl may occur. If the amount is more than 40 parts by weight, gloss may be excessively obtained, and furthermore, storage stability may be deteriorated.

When the softening point of the release agent used in the present invention is 70 to 100 ° C., a toner excellent in storability, which is the fourth object of the present invention, can be obtained. When the softening point is lower than 70 ° C., not only the storage stability but also the surface of the image becomes rough and the gloss tends to be low. On the other hand, even if the softening point is higher than 100 ° C., the image surface is likely to be rough and the gloss is low, so that the color image tends to be poor.

Specific release agents include synthetic waxes such as low molecular weight polyethylene and polypropylene, and copolymers thereof, vegetable waxes such as candelilla wax, carnauba wax, rice wax, wood wax, jojoba wax, and the like. Animal waxes such as beeswax, lanolin, and whale wax; mineral waxes such as montan wax and ozokerite; hardened castor oil; and oil waxes such as hydroxystearic acid, fatty acid amide, and phenol fatty acid ester. From the viewpoint of chemical structure, hydrocarbon waxes, ester waxes, amide waxes and the like are known from the viewpoint of chemical structure. In the present invention, the ester waxes are used for preservation, image quality, fixing temperature and the like. It is preferable to evaluate the width and the like. The amount of the release agent is preferably 1 to 6 parts by weight based on the whole toner. If the amount is more than 6 parts by weight, problems may occur in storage stability and the like, and the surface of the image may be rough and the gloss may be low. If the amount is less than 1 part by weight, the color image is likely to be poor, for example, the image surface is easily roughened and the gloss is reduced.

Next, other materials used in the dry toner of the present invention will be described. First, all known dyes and pigments can be used as the colorant. For example, carbon black, nigrosine dye, iron black, naphthol yellow S,
Hansa Yellow (10G, 5G, G), Cadmium Yellow, Yellow Iron Oxide, Loess, Graphite, Titanium Yellow, Polyazo Yellow, Oil Yellow, Hansa Yellow (GR, A,
RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, leadtan,
Lead vermilion, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, phisay red, parachloroortho nitroaniline red, lithol fast scarlet G, brilliant fast scarlet, brilliant carmine B
S, permanent red (F2R, F4R, FRL, F
RLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G,
Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B,
Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thio Indigo Maroon, Oil Red, quinacridone red, pyrazolone red, polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Navy Blue, Anthraquinone Blue, Fast Ioretto B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, viridian, emerald green, Pigment Green B, Naphthol Green B, green gold, acid green lake,
Malachite green lake, phthalocyanine green,
Anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof. The amount used is generally 0.1 to 50 parts by weight based on 100 parts by weight of the binder resin.

The toner of the present invention may optionally contain a charge control agent. All known charge control agents can be used, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines,
Quaternary ammonium salts (including fluorinated quaternary ammonium salts), alkylamides, phosphorus alone or compounds, tungsten alone or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts.

Other additives include, for example, colloidal silica, hydrophobic silica, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (such as titanium oxide, aluminum oxide, tin oxide and antimony oxide), It may contain a fluoropolymer or the like. The toner of the present invention composed of the above materials may be used as a two-component developer together with a carrier, or may be used as a one-component developer with a carrier contained therein. As the carrier used here, iron powder, ferrite, glass beads and the like are the same as those in the related art. These carriers may be coated with a resin. The resin used in this case is carbon fluoride, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, silicone resin and the like. In any case, the mixing ratio of the toner and the carrier is generally suitable for about 0.5 to 6.0 parts by weight of the toner with respect to 100 parts by weight of the carrier.

The following methods are used for measuring the softening point and Tg of the polyol resin of the present invention. First, as a device for measuring the softening point, a fully automatic dropping device F of Metra
The measurement is performed using P5 / FP53 in the following procedure. After the ground sample is placed in a melting pot and left for 20 minutes, the sample is poured up to the edge of a sample cup (droplet diameter: 6.35 mm), cooled to room temperature, and set in a cartridge. A predetermined heating rate (1
(° C./min) Set the measurement start temperature (set to 15 ° C. or less of the expected softening temperature). After mounting the cartridge in the FP-53 heating furnace and leaving it for 30 seconds, the start lever is pushed down to start the measurement (the subsequent measurements are automatically performed). When the measurement is completed, remove the cartridge. The softening point (° C.) is calculated as follows. FP-5 Result display panel A value + correction value Note) If the above correction value is added to the obtained result, it corresponds to the result of the Duran mercury method. Note) The value of the result display panel A and the measurement start temperature (panel B,
If the difference is not more than 15 ° C, repeat the test.

Next, as a device for measuring Tg, a DSC-200 manufactured by Seiko Denshi is used, and the Tg is measured according to the following procedure. The sample is pulverized, weighed 10 ± 1 mg into an aluminum sample container, and the aluminum lid is crimped from above. Glass transition point (Tg) by DSC method in nitrogen atmosphere
Is measured. Analysis conditions After heating the sample from room temperature to 150 ° C. at a rate of temperature increase of 20 ° C./min, leave it at 150 ° C. for 10 minutes, cool the sample to 0 ° C. at a rate of temperature decrease of 50 ° C./min and leave it for 10 minutes, The sample is heated again to 150 ° C. at a rate of 20 ° C./min at a rate of 20 ° C./min for DSC measurement. As for Tg, the peak rising temperature is read using analysis software [Tg job]. The epoxy equivalent is JI
The indicator titration method described in 4.2 of SK7236 was used.

Hereinafter, the present invention will be described with reference to examples.
All parts are parts by weight. These embodiments are merely examples of the present invention, and the present invention is not limited to the embodiments.

Example 1 The following mixture of each color toner formulation was melt-kneaded by a hot roll mill, cooled, coarsely ground by a hammer mill, and finely ground by an air jet mill to obtain a fine powder of 5 to 15 μm.
Of each particle size. Yellow toner formulation: 100 parts of polyol resin 1 (Mn: 4200, Mw / Mn: 6.2, alkylene oxide adduct: 20 parts by weight, alkylene oxide adduct / epoxy resin: 38% by weight, Tg: 61 ° C., softening point : 120 ° C, epoxy equivalent: 20000 or more) The polyoxyalkylene portion of the main chain was confirmed by NMR. Carnauba wax (ester wax, melting point: about 82 ° C.) 3 parts Yellow pigment (Lionol Yellow FGN-T manufactured by Toyo Ink Mfg. Co., Ltd.) 5 parts E-84 manufactured by Orient Chemical Co., Ltd. 2 parts Magenta toner formulation: Polyol resin 1 100 Part Carnauba wax 3 parts Red pigment (Rionogen Magenta R manufactured by Toyo Ink Mfg. Co., Ltd.) 5 parts E-84 manufactured by Orient Chemical Co., Ltd. 2 parts Cyan toner formulation: Polyol resin 1 100 parts Carnauba wax 3 parts Blue pigment (Toyo) 2 parts Orion Chemical Industry Co., Ltd. E-84 2 parts Black toner formulation: 100 parts polyol resin 1 carnauba wax 3 parts Black pigment (carbon black) 4.5 parts Orient Chemical Industry E-84, 2 parts

Next, 5 parts of each color toner is made to have an average diameter of 50 μm.
Was mixed with 95 parts of a carrier obtained by coating the spherical ferrite with a silicone resin to prepare a two-component developer of each color. Next, these four color developers are set in a commercially available color electrophotographic copying machine (Pretail 550, manufactured by Ricoh Co., Ltd.), developed for each color, and each toner image is transferred to copy paper. Sampled. Thereafter, when a roller was fixed with a simple device in which an oil pad was merely applied to the fixing portion, a clear image having an average glossiness of 25% was formed. When the image was observed while changing the fixing temperature, the temperature range over which a good image was obtained was 30 ° C. Furthermore, full-color images can be converted to overhead projectors (OH
When fixed on a transparent sheet for P) and projected by OHP, a clear full-color image without any turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, left in a constant temperature bath set at 50 ° C. for 5 hours, and measured for penetration with a penetrometer. The degree was 20 or more. The gloss was measured as follows. Using a color copying machine Pretail 550 manufactured by Ricoh Company, a color developer is set on a commercially available electrophotographic copying machine for color (Ricoh Pretail 550 manufactured by Ricoh Company), and transfer paper (Ricoh Type 6000-70) is set.
W), a solid image consisting of a single color of yellow, magenta, cyan, and black was applied with a toner development amount of 0.8 mg / cm.
Develop with reference to ² and fix at a fixing temperature of 160 ° C.
In the above single-color fixed image sample, a gloss meter (VG
-1D) (manufactured by Nippon Denshoku Co., Ltd.), adjusting the light projecting angle and the light receiving angle to 60 °, respectively, and setting S and S / 10 switching switches.
Is adjusted to S, using 0 preparation and a standard plate, and after setting the standard, the image is placed on the sample table and measured.

Example 2 Yellow toner formulation: 100 parts of polyol resin 2 (Mn: 5200, Mw / Mn: 7.5, alkylene oxide adduct: 25 parts by weight, alkylene oxide adduct / epoxy resin: 48% by weight, Tg : 63 ° C, softening point: 130 ° C, epoxy equivalent: 20,000 or more) The polyoxyalkylene portion of the main chain was confirmed by NMR. Jojoba wax (ester wax, softening point: about 74 ° C) 3 parts Yellow pigment (Toyo Ink Mfg. Co., Ltd. Lionol Yellow FGN-T) 5 parts Orient Chemical Industries E-84 2 parts

For the other three colors, toner was prepared using Resin 2 and jojoba wax in the same procedure. When an image was formed in the same procedure, a clear monochromatic image having an average glossiness of 16% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 35 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. 10 g of each color toner
Each of the toners was weighed, placed in a 20 cc glass container, and left in a thermostat set at 50 ° C. for 5 hours. The penetration was measured with a penetration meter. Was.

Example 3 Yellow Toner Formulation: 100 parts of polyol resin 1 part 3 parts of polypropylene wax (NP055 manufactured by Mitsui Petrochemical: melting point 145 ° C.) 5 parts of yellow pigment (Rionol Yellow FGN-T manufactured by Toyo Ink Mfg. Co., Ltd.) 5 parts Orient Chemical Industries 2 parts of E-84 manufactured by Co., Ltd. For the other three colors, toner was prepared using Resin 1 and polypropylene wax in the same procedure. When an image was formed in the same procedure, an image having an average glossiness of 10% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 15 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. Also, 10 g of each color toner is weighed, and 2 g
After placing in a 0 cc glass container and leaving it in a thermostat set at 50 ° C. for 5 hours, the penetration was measured by a penetration meter, and the penetration was 20 or more for all toners.

Example 4 A toner was prepared in the same procedure as in Example 1, except that the amount of carnauba wax was changed to 0.5 part by weight. When an image was formed in the same procedure, an image having an average glossiness of 12% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 15 ° C.
Met. Furthermore, the full-color image is fixed on a transparent sheet for overhead projector (OHP),
When projected at P, a clear full-color image without any turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, left in a constant temperature bath set at 50 ° C. for 5 hours, and measured for penetration with a penetrometer. The degree was 20 or more.

Example 5 A toner was prepared in the same procedure as in Example 1 except that the amount of carnauba wax was changed to 10 parts by weight. When an image was formed in the same procedure, an image having an average glossiness of 25% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 15 ° C. Further, the full-color image is fixed on a transparent sheet for overhead projector (OHP),
As a result, a clear full-color image without any turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, left in a constant temperature bath set at 50 ° C. for 5 hours, and measured for penetration with a penetrometer. The degree was 12 or more.

Example 6 A toner was prepared in the same manner as in Example 1 except that candelilla wax (ester wax, melting point: about 69 ° C.) was used in an amount of 3 parts by weight instead of carnauba wax. When an image was formed by the same procedure, each monochromatic image having an average glossiness of 8% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 10 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. Also, 10 g of each color toner is weighed and placed in a 20 cc glass container.
After standing for 5 hours in a thermostat set at a temperature of ° C., the penetration was measured with a penetration meter, and the penetration was 0 for all toners.

Example 7 A toner was prepared in the same procedure as in Example 1, except that 3 parts by weight of microcrystalline wax (C700, melting point: 91 ° C.) was used instead of carnauba wax. When an image was formed in the same procedure, an image having an average glossiness of 12% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 10 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. Also, 10 g of each color toner is weighed and placed in a 20 cc glass container,
After standing in a thermostat set at 50 ° C. for 5 hours, the penetration was measured with a penetration meter, and the penetration was 5 or more for all the toners.

Example 8 In place of resin 1, resin 3 (Mn: 3300, Mw / M
n: 6.5, alkylene oxide adduct: 25 parts by weight, alkylene oxide adduct / epoxy resin: 48
% By weight, Tg: 61 ° C., softening point: 118 ° C., epoxy equivalent: 1750, and the polyoxyalkylene portion of the main chain was confirmed by NMR. ) Except that the toner was prepared in the same manner as in Example 1, except that the yellow toner gelled during kneading and the trial production was stopped halfway. The other three
When a color was used to form an image in the same procedure, a clear image having an average glossiness of 25% was formed. When the image was observed while changing the fixing temperature, the temperature range over which a good image was obtained was 30 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, and left in a constant temperature bath set at 50 ° C. for 5 hours.
When the penetration was measured with a penetration meter, the penetration was 20 or more for all the toners.

Example 9 In place of resin 1, resin 4 (Mn: 3600, Mw / M
n: 4.3, alkylene oxide adduct: 25 parts by weight, alkylene oxide adduct / epoxy resin: 48
% By weight, Tg: 59 ° C., softening point: 112 ° C., epoxy equivalent: 20,000 or more, and the polyoxyalkylene portion of the main chain was confirmed by NMR. ) Except that the toner was prepared in the same manner as in Example 1. When an image was formed by the same procedure, a clear monochromatic image having an average glossiness of 8% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 5
° C. In addition, the full-color image is fixed on a transparent sheet for overhead projector (OHP),
When projected by HP, a clear full-color image without any turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, left in a constant temperature bath set at 50 ° C. for 5 hours, and measured for penetration with a penetrometer. The degree was 20 or more.

Example 10 Resin 5 (Mn: 5500, Mw / M) instead of Resin 1
n: 7.8, alkylene oxide adduct: 30 parts by weight, alkylene oxide adduct / epoxy resin: 58
% By weight, Tg: 63 ° C., softening point: 133 ° C., epoxy equivalent: 20,000 or more, and the polyoxyalkylene portion of the main chain was confirmed by NMR. ) Except that the toner was prepared in the same manner as in Example 1. When an image was formed in the same procedure, an image having an average glossiness of 5% was formed. When the image was observed while changing the fixing temperature, the temperature range over which a good image was obtained was 30 ° C. Further, when the full-color image was fixed on a transparent sheet for an overhead projector (OHP) and projected by the OHP, a clear full-color image without turbidity was projected. Also, 10 g of each color toner is weighed, and 2 g
After placing in a 0 cc glass container and leaving it in a thermostat set at 50 ° C. for 5 hours, the penetration was measured by a penetration meter, and the penetration was 20 or more for all toners.

Example 11 In place of resin 1, resin 6 (Mn: 4700, Mw / M
n: 5.0, alkylene oxide adduct: 2 parts by weight,
Alkylene oxide adduct / epoxy resin: 4% by weight, Tg: 62 ° C, softening point: 118 ° C, epoxy equivalent:
More than 20,000, the polyoxyalkylene part of the main chain was confirmed by NMR. ) Except that the toner was prepared in the same manner as in Example 1. When an image was formed in the same procedure, an image having an average glossiness of 8% was formed. When the image was observed while changing the fixing temperature, the temperature range in which a good image was obtained was 20 ° C.
However, a phenomenon was observed in which the gloss of the front end of the image was higher than that of the other portions. In addition, the full-color image is fixed on a transparent sheet for overhead projector (OHP),
When projected by HP, a clear full-color image without any turbidity was projected. Also, 10 g of each color toner was weighed, placed in a 20 cc glass container, left in a constant temperature bath set at 50 ° C. for 5 hours, and measured for penetration with a penetrometer. The degree was 20 or more.

Comparative Example 1 Resin 7 (Mn: 3600, Mw / M) instead of Resin 1
n: 3.5, alkylene oxide adduct: 20 parts by weight, alkylene oxide adduct / epoxy resin: 38
% By weight, Tg: 58 ° C., softening point: 110 ° C., epoxy equivalent: 20,000 or more, and the polyoxyalkylene portion of the main chain was confirmed by NMR. ) Except that the toner was prepared in the same manner as in Example 1. When an image was formed in the same procedure, an image having an average glossiness of 0.5% was formed. However, a fixable area free from the offset phenomenon was not substantially obtained, and the temperature width was not substantially. The offset phenomenon also occurred in the overhead projector (OHP) transparent sheet, and the image became dark and cloudy.

Hereinafter, embodiments of the present invention will be described. 1. In a dry electrophotographic toner containing at least a colorant, a release agent, and a binder resin, the binder resin is an epoxy resin (a), a dihydric phenol (b), or an alkylene oxide adduct of a dihydric phenol or an adduct thereof. A dry electrophotographic toner which is a polyol resin having a polyoxyalkylene moiety in the main chain and having a Mw / Mn of 4 to 10, preferably 5 to 8, synthesized by reacting glycidyl ether (c). 2. The dry electrophotographic toner according to 1, wherein the polyol resin contains 10 to 40 parts by weight of the component (c) based on 100 parts by weight of the polyol resin. 3. The dry electrophotographic toner according to any one of the above items 1 to 2, wherein the component (a) is at least two or more bisphenol type epoxy resins having different number average molecular weights. 4. The component (a) has a number average molecular weight of 360 to 2.0.
00 low molecular weight component and number average molecular weight 3,000-1
The above-mentioned 1 which is composed of 000 high molecular weight components.
≪ 3 > dry toner for electrophotography.

5. The polyol resin has an epoxy equivalent of 2
The dry electrophotographic toner according to any one of the above items 1 to 4, which is not less than 000. 6. The toner for dry electrophotography according to any one of the above items 1 to 5, wherein the polyol resin further has a terminal epoxy group reacted with a monohydric phenol or an excess of a dihydric phenol to have no epoxy group. 7. An alkylene oxide adduct of a dihydric phenol is
The dry electrophotographic toner according to any one of the above items 1 to 6, which is an adduct of ethylene oxide, propylene oxide or a mixture thereof with bisphenol A, bisphenol F or the like. 8. The dry electrophotographic toner according to any one of the above items 1 to 6, wherein the glycidyl ether of the alkylene oxide adduct of a dihydric phenol is the glycidyl ether of the adduct of the above item 7. 9. (1) wherein the component (c) is 10 to 50 parts by weight based on 100 parts by weight of the component (a).
8. The toner for dry electrophotography of 8.

10. 10. The dry electrophotographic toner according to any one of 1 to 9 above, wherein the release agent has a melting point of 70 to 100 ° C. 11. The dry electrophotographic toner according to any one of the above 1 to 10, wherein the content of the release agent in the toner is 1 to 6 parts by weight. 12. 12. The dry electrophotographic toner according to any one of 1 to 11, wherein the release agent is an ester wax.

[0037]

[Effects] By using the dry electrophotographic toner of the present invention, color reproducibility is excellent, gloss is stable and unevenness can be obtained even when a simple oil applying and fixing device such as an oil roller or an oil applying felt is used. No image was obtained, making it possible to reduce the size of the device and simplify maintenance.

Claims (7)

[Claims] 1. A dry electrophotographic toner containing at least a colorant, a release agent and a binder resin, wherein the binder resin is an epoxy resin (a), a dihydric phenol (b), or an alkylene of a dihydric phenol. A dry electrophotographic toner comprising a polyol resin having a polyoxyalkylene moiety in the main chain and having a Mw / Mn of 4 to 10 synthesized by reacting an oxide adduct or its glycidyl ether (c). 2. The polyol resin is prepared by adding the component (c) in an amount of 10 to 40 with respect to 100 parts by weight of the polyol resin.
2. The dry electrophotographic toner according to claim 1, wherein the toner is contained in parts by weight. 3. The dry electrophotographic toner according to claim 1, wherein the component (a) is at least two or more bisphenol epoxy resins having different number average molecular weights. 4. A polyol resin having an epoxy equivalent of 20,
The dry electrophotographic toner according to any one of claims 1 to 3, wherein the toner is not less than 000. 5. The polyol resin having a softening point of 115 to 1
The dry electrophotographic toner according to any one of claims 1 to 4, which has a temperature of 30C. 6. The dry electrophotographic apparatus according to claim 1, wherein the component (c) is 10 to 50 parts by weight based on 100 parts by weight of the component (a) in the polyol resin. toner. 7. The dry electrophotographic toner according to claim 1, wherein the release agent has a melting point of 70 to 100 ° C.