JPH03126955A - Dry electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain a dry electrophotographic toner superior in color reproduction performance and not migrating to a vinyl chloride resin type sheet by using a mixture of a specified modified epoxy resin and a polyester resin made from a bisphenol type diol and a polyvalent carboxylic acid as a binder resin. CONSTITUTION:The toner comprises as main components a colorant and the binder resin of the mixture of the modified epoxy resin and the polyester resin made from the bisphenol type diol and the polyvalent carboxylic acid, and the epoxy resin is obtained by reacting the epoxy resin with primary amines and divalent phenols to extend the fundamental skeleton of the epoxy resin, and esterifying its secondary hydroxyl group with lactones, thus permitting the obtained dry electrophotographic toner to be good in color reproduction performance and not to migrate to the vinyl chloride resin mat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement in a dry electrophotographic toner containing a colorant and a binder resin as main components.

[Conventional technology]

In dry electrophotography, an electrostatic latent image is formed on a photoreceptor using a conventional method, and after development with dry toner, the toner image is transferred onto copy paper, and then thermally fixed (usually using a heated roller) to obtain a copy. ing. As is well known, the dry toner used in this method is mainly composed of a binder resin and a colorant, and contains additives such as a charge control agent and an anti-offset agent if necessary. Here, the binder resin has the characteristics required for toner use, namely transparency.

a@Polystyrene, styrene-acrylic copolymer, polyester resin, epoxy resin, etc. are generally used in terms of edgeability, water resistance, fluidity (as a powder), mechanical strength, gloss, thermoplasticity, crushability, etc. Among them, styrene resins are widely used because they have excellent crushability, water resistance, and fluidity. However, in order to preserve copies obtained with styrene-based resin-containing toner, if they are placed in a document holder made of a vinyl chloride-based resin sheet, the image side of the copy is left in close contact with the sheet. The plasticizer contained in the vinyl chloride resin transfers to the fixed image, plasticizes it, and attaches it to the sheet side. As a result, when the copy is removed from the sheet, part or all of the toner image peels off from the copy. However, there was a drawback that the mat sheet also got dirty.

As a measure to prevent conversion to vinyl chloride resin sheets as described above, Japanese Patent Application Laid-open No. 60-263951 and No. 61-2402
No. 5 proposes blending an epoxy resin that is not plasticized with a plasticizer for seeded vinyl resins with a styrene resin or polyester resin.

However, when such blended resins are used especially for color toners, the incompatibility of different resin levels may cause offset properties, curling of fixed images, and glossiness (in the case of color toner images, poor image quality due to lack of gloss). (Visible as) 1 Coloration, transparency.

Color development becomes an issue.

In addition, proposals have been made regarding epoxy resin toners mainly made of epoxy resins, but conventionally known epoxy resins do not necessarily provide sufficient properties such as offset properties, curling of fixed images, glossiness, etc. , Japanese Patent Publication No. 6
Even the acetylated modified epoxy resin proposed in No. 1-235852 does not solve all the problems.

Further, JP-A No. 61-219051 discloses a toner using an epoxy resin ester-modified with ε-caprolactone as a binder resin, but although the PVC resistance and fluidity are improved, the amount of modification is The weight ranged from 3 to 90%, the softening point was too low, and there was no gloss.

Furthermore, JP-A No. 61-223850 discloses a mixture of ester-modified epoxy resin with ε-caprolactone and styrene-butadiene rubber and polyester, but it has poor PVC resistance, offset resistance, etc. Although this is an improvement, since it uses a modified epoxy resin with a large amount of modification, it has the disadvantage that it does not produce gloss even when blended with other resins.

Furthermore, JP-A No. 61-223849 discloses a mixture of polyester and an epoxy resin ester-modified with ε-caprolactone, but similarly to the above, a modified epoxy resin with a large amount of modification is used. For,
Even when blended with other resins, it had the drawback of not being glossy.

In recent years, durable Teflon-coated rollers have been used in addition to silicone rubber-coated rollers as heat rollers for fusing, and the hard and rough Teflon coating has problems with offset, curling and gloss of fixed images. Therefore, toners are required to have a wide range of fixing properties.

Another problem with epoxy resins is charging stability.

Generally, a toner is composed of a binder resin, a colorant, a charge control agent, etc.6 Various dyes and pigments are known as colorants, and some of them also have a charge control agent.1 Colorant and charge control agent Some have two functions:

Although it is widely practiced to use an epoxy resin as a binder resin to form a toner with the above-mentioned composition, the problem is the dispersibility of dyes, pigments, electrical control agents, etc. Generally, the mixing of the binder resin, dyes, pigments, charge control agents, etc. is carried out in a hot roll mill, and it is necessary to uniformly disperse the dyes, pigments, charge control agents, etc. in the binder resin. However, it is difficult to achieve sufficient dispersion, and poor dispersion of dyes and pigments as colorants will result in poor color development and low coloring, and poor dispersion of charge control agents will result in uneven charge distribution and poor charging. , dirt, scattering, 10 shortage.

This can cause various defects such as dullness and poor cleaning.

JP-A No. 52-86334 discloses a product that has positive chargeability by reacting an aliphatic-class or secondary amine with the terminal epoxy group of a ready-made epoxy resin. In the reaction, the amount of amine to be reacted is limited, which makes it difficult to set a desired charging level.Also, since long chain amines are introduced at both ends, charging is unstable, making it difficult to disperse dyes and pigments. It does not contribute to sex either.

[Problem to be solved by the invention]

A first object of the present invention is to provide a toner for dry electrophotography with excellent color reproducibility.

A second object of the present invention is to provide a toner for dry electrophotography that can be used in heat roll fixing to produce fixed images that are free from offset, have sufficient gloss, and have almost no curl.

A third object of the present invention is to provide a toner for dry electrophotography that is positively chargeable and stable.

A fourth object of the present invention is to provide a toner that has good compatibility with other resins and has good dispersion of dyes and pigments.

A fifth object of the present invention is to provide a toner for dry electrophotography in which the toner image does not transfer to the vinyl chloride resin sheet even when the fixed image surface of the copy is brought into close contact with the sheet.

A seventh object of the present invention is to provide a toner with good crushability.

[Means to solve the problem]

The toner of the present invention is a dry electrophotographic toner containing a colorant and a binder resin as main components. It is a mixed system of a modified epoxy resin obtained by esterifying the secondary hydroxyl group of with a lactone, and a polyester resin consisting of a bisphenol diol and a polyhydric carboxylic acid,
Preferably, the amount of the modified epoxy resin is 95 to 60 parts by weight, and the amount of the polyester resin is 5 to 40 parts by weight.

The inventors of the present invention have conducted various studies in order to obtain a fixed image with sufficient gloss without offset and with less curl in heat roll fixing, and as a result, the inventors have found that the epoxy resin can be made soft or flexible like silicone rubber. We focused on In accordance with this, an elastic component is introduced into an epoxy resin to give it a flexible structure based on a seabird structure, thereby creating a modified epoxy resin that is softened or flexible, and when this is used as a binder resin, the above objective can be achieved. I found out.

Furthermore, as a result of various studies in order to obtain a toner with stable positive charging, good compatibility with other resins, and good dispersion of dyes and pigments, the inventors of the present invention introduced a primary amine into the main chain of the epoxy resin. When a modified epoxy resin was prepared and used as a binder resin, it was discovered that the above object could be achieved.

Here, the elastic component introduced into the epoxy resin is introduced by esterifying the secondary hydroxyl group of the epoxy resin with a lactone. In this case, effects such as the softening point of the modified epoxy resin and the gloss of the fixed image can be changed depending on the esterification rate, but in the present invention, this esterification rate is 3.
It is preferably about 20% by weight. If it is less than 3 weight, sufficient softness or flexibility will not be obtained, and the gloss of the fixed image will be insufficient, and if it exceeds 20 weight, the softening point of the modified epoxy resin obtained will be low. In addition to causing problems in fixing properties, the fixed image also lacks gloss.

Further, specific examples of lactones include p-propiolactone, δ-valerolactone, ε-caprolactone, β-
Examples include butyrolactone and γ-valerolactone, with γ-butyrolactone and ε-caprolactone being particularly preferred. Note that these lactones are used in a molar number corresponding to the number of hydroxyl groups contained in the epoxy resin.

The basic skeleton of the modified epoxy resin according to the present invention is:

Epoxy resin is reacted with primary amines and dihydric phenols to extend the chain length. The modified epoxy resin of the present invention exhibits positive polarity due to the introduction of amine into the resin molecule. Compared to positively chargeable resins obtained by adding charge control agents or blending nitrogen-containing polymers, the charge stability is significantly improved and durability is sufficient. Furthermore, it is possible to arbitrarily set the charging level depending on the amount introduced. Furthermore, by introducing a primary amine having a long-chain alkyl group, the modified epoxy resin of the present invention forms a comb-shaped structure, thereby improving the dispersibility of dyes and pigments and improving the compatibility with other resins.

Specific examples of the primary amine used in the present invention include propylamine, butylamine, hexylamine, octylamine, laurylamine, stearylamine, palmitylamine, oleylamine, etc. as aliphatic primary amines. has 6 to 20 carbon atoms. Examples of aromatic primary amines include aniline, toluidine, xylidine, cumidine, hexylaniline, nonylaniline, dodecylaniline, etc. Preferably, the benzene nucleus of aniline has 3 to 20 carbon atoms.
It is a compound with alkyl groups bonded together.

The amount of amine introduced is 0.01 to 1.00% by weight based on 100 parts by weight of the epoxy resin. By esterifying the epoxy resin and introducing an amine into the main chain in this manner, the above-mentioned object of thinning can be achieved. Note that the esterification does not in any way impede the objective achieved by the introduction of the amine, nor vice versa.

A typical example of the epoxy resin used in the present invention is a polycondensate of bisphenol A and epichlorohydrin. Commercial products of such epoxy resins include Epomic R301, Epomic R302, and Epomic R304.
, Epomic R304P, Epomic R307, Epomic R309, Epomic R362, Epomic R36
3. Epomic R364, Epomic R365, Epomic R366, Epomic R367 (manufactured by Mitsui Petrochemical Industries, Ltd.), etc.

Furthermore, there are also epoxy resins with arbitrary softening points obtained by polyaddition reaction between liquid epoxy resins and bisphenols. Evomic R1 is a commercially available liquid epoxy resin.
40, Epomic R139, Evomic R140P (manufactured by Mitsui Petrochemical Industries, Ltd.), etc.

Examples of bisphenols include bisphenol A, bisphenol F, and bisphenol AD.

Furthermore, the present inventors have conducted various studies on the modified epoxy resin of the present invention in order to obtain even better fixing properties without impairing its basic properties. It has been found that a mixed system with a polyester resin consisting of carboxylic acid is effective.

This further improves the offset resistance and also improves the crushability during toner production. Since two different resins are blended, compatibility becomes an issue.
By regulating the mixing ratio, offset resistance can be improved without substantially impairing the basic properties of the modified epoxy resin.

That is, a preferred embodiment of the binder resin of the present invention is one in which 5 to 40 parts by weight of the polyester resin is mixed with 95 to 60 parts by weight of the modified epoxy resin. If the amount of the polyester resin is less than 5 parts by weight, no improvement in the offset property is observed, while if it exceeds 40 parts by weight, the negative chargeability becomes strong and it becomes difficult to control the polarity of the positive chargeability. The mixing ratio of the polyester resin is preferably 90% of the modified epoxy resin.
-75 parts by weight, 10 to 25 parts by weight.

The polyester resin used in the present invention is a thermoplastic saturated or unsaturated polyester obtained by condensation of bisphenol diols and polycarboxylic acids. Representative diols are shown below.

(a') Polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane; (b) Polyoxyethylene (2)-2,2-bis(4-
(c) polyoxystyrene (6)-2,2-bis(4-
hydroxyphenyl)propane; (d) polyhydroxybutylene (2)-2,2-bis(
4-hydroxyphenyl)propane; (e) polyoxypropylene (3)-bis(4-hydroxyphenyl)thioether; (f) polyoxypropylene (2)-2,2-bis(4)
-cyclohexanol)propane; (g) polyoxyethylene (2)-2,6-dichloro-
4-hydroxyphenyl; (h) polyoxyethylene (L5)-ptp-bisphenol; (i) polyoxybutylene (4) bis(4-hydroxyphenyl) ketone: (j) polyoxyethylene-2,2-bis( and (k) polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane.

Examples of polycarboxylic acids include maleic acid, fumaric acid, glutaric acid, phthalic acid, maleic anhydride, fumaric anhydride, phthalic anhydride, and isophthalic acid.

Examples include terephthalic acid, trimellitic acid, and 1,2.4-benzenetricarboxylic acid.

Examples of polyester resins using these diols and polyhydric carboxylic acids include: Resin Example 1: Polyester with a softening point of 100°C made from the diol (a) and fumaric acid; Resin Example 2: Diol (b) above and terephthalic acid; Resin Example 3: Polyester with a softening point of 110°C and the above diol (e) and isophthalic acid; Resin Example 4: The above diol (a), fumaric acid, and trimellitic acid Polyester having a softening point of 130° C. when mixed with an acid; and Resin Example 5: Polyester having a softening point of 100° C. when mixed with the diol (j) and fumaric acid.

These resins may be used alone or in combination of two or more.The resin for toner of the present invention may include one or more of the following:
Although it is a blend of a modified epoxy resin and a specific polyester resin, the physical properties of the toner are determined by the characteristics of the modified epoxy resin, and furthermore, it is possible to obtain improved offset resistance and crushability.

Next, other materials used in the dry toner of the present invention will be explained.

First, all known dyes and pigments can be used as colorants, such as carbon black, nigrosine dye, iron black,
Naphthol Yellow S, Hansa Yellow (IOG, 5G
, G), cadmium yellow, yellow iron oxide, loess,
Yellow lead, titanium yellow, polyazo yellow, oil yellow,
Hansa Yellow (GR, A, RN, R), Pigment Yellow, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Palcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, isoindolinone yellow, red red, red lead, lead powder, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, rose red, phise red,
Parachlororthonitroaniline red, Lysol Fast Scarlet G, Brilliant Fast Scarlet Sotho, Brilliant Carmine BS, Permanent Red (
F2R, F4R, FRL, FRLL, F4RH),
Fast Scarlet VD, Belkan Fast Lupine B
.

Lysol Red, Lake Red (C, O), Anthosine B, Brilliant Scarlet G, Lysol Rubin GX
, Permanent Red F5R, Brilliant Carmine 6
B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2, Heliobolido BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio. Indigo red B, thioindigo reddon, oil red, oil pink, cinchonaacridone red, birazolene red, polyazo red, chrome permillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkaline blue lake, peacock blue Rake, Victoria Blue Rake, Metal Free Phthalocyanine Blue Phthalocyanine Blue, Fast Sky Blue Indans Rake (R5
, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium chloride, pyridian, 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 o, i to 50 parts by weight per 100 parts by weight of the binder resin.

The toner of the present invention may contain a charge control agent if necessary, and all known charge control agents can be used.
For example, nigrosine dyes, triphenylmethane dyes,
Chromium-containing metal complex dye, molybdate chelate pigment,
These include rhodamine dyes, alkoxy amines, quaternary ammonium salts, alkylamides, phosphorus alone or compounds, tungsten alone or compounds, fluorine activators, metal salts of salicylic acid and metal salts of salicylic acid derivatives, hydrophobic silica, and the like.

Other additives include colloidal silica, hydrophobic silica, silicone oil, metal soap, nonionic surfactants, fatty acid metal salts (zinc stearate, aluminum stearate, etc.), metal oxides (titanium oxide,
(aluminum oxide, tin oxide, antimony oxide, etc.), fluoropolymer, etc.

The toner of the present invention made 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 added thereto.

The carriers used here include iron powder, ferrite,
Conventionally known materials such as glass peas can be used. In addition,
These carriers may be coated with a resin, and the resins used in this case include polyfluorocarbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, silicone resin, acrylic resin, and the like. These may be used alone or in combination of two or more. In any case, the mixing ratio of toner and carrier is generally 0.5 to 0.5 parts by weight of toner to 100 parts by weight of carrier.
Approximately 6.0 parts by weight is appropriate.

〔Example〕

Hereinafter, the present invention will be explained by examples. Note that all parts are parts by weight.

Example 1 250 g of bisphenol A epoxy resin (Evomic R140P, manufactured by Mitsui Petrochemicals), 119 g of bisphenol A, and 50 ml of xylene were added to a separable flask equipped with a stirrer, thermometer, N2 inlet, and cooling tube, and the mixture was heated to 70 m2 under an N2 atmosphere. The temperature was raised to .degree. C., 0.65N aqueous sodium hydroxide solution was added, and the temperature was then raised to 150.degree. C., during which time water and xylene were distilled off under reduced pressure. The reduced pressure was released, 1 g of stearylamine was added, and after reacting at 85°C for 5 hours, 20 g of ε-caprolactone was added and the reaction was continued for a further 6 hours to form a modified epoxy with a softening point of 144°C and an N content of 0.15 weight 2. A resin (hereinafter referred to as resin A) was obtained.

Next, a mixture of the following color toner formulations is melt-kneaded in a heated roll mill, cooled, coarsely pulverized in a hammer mill, and finely pulverized in an air jet pulverizer, and the resulting fine powder is classified into particle sizes of 5 to 15 particles. I made toners for each color. The feed rate of the feeder during fine pulverization was 530 g/hr.

Yellow Toner Formula Resin A 90 parts Polyester resin of Resin Example 1 10 parts Magenta Toner Formula: Resin A 90 parts Polyester resin of Resin Example 1 10 parts Cyan Toner Formula: Resin A 90 parts Polyester resin of Resin Example 1 10 parts Blue pigment ( Lionol Blue FG-7351 (manufactured by Toyo Ink Mfg. Co., Ltd.) 2 parts Next, 3.5 parts of each color toner was mixed with 96.5 parts of iron powder carrier (TEFV23, manufactured by Nippon Tetsuko Co., Ltd.) to form various two-component developers. made.

When the charge amount of the obtained developer was measured by the blow-off method, the yellow developer was +14.6 μc/g, the magenta developer was +12.1 μc/g, and the cyan developer was +14 μc/g.
．． It was 2μc/g.

Next, these three types of color developers were set in a commercially available electrophotographic copying machine for color (improved model of Color 3000 manufactured by Ricoh Co., Ltd.), and each color was developed. After each toner image was transferred to copy paper, a heated roller was used. When fixed, clear single-color yellow, magenta, and cyan images with an average gloss of 22% were formed.

Furthermore, clear images with an average gloss level of 22 f were formed even in red, blue, and green fixed images obtained by two-color overlapping development. Furthermore, the average gloss level is 20 even for fixed images created by three-color overlapping development.
% clear full color images were obtained. Note that the lower limit fixing temperature was 110°C, and the hot offset generation temperature was 190°C.

Further, when a solid image was fixed on the entire surface by three-color overlapping development, there was almost no curl, especially at the edges of the fixed image, and the image was smooth.

In addition, a full-color image is displayed using an overhead projector (
When it was fixed on a transparent sheet for IP) and projected at 0f (P), a clear full-color image with no turbidity was projected.Furthermore, the full-color image was adhered to a vinyl chloride resin sheet and left at room temperature for 180 hours. When a storage test was conducted, no toner transfer to this sheet was observed, and the full color image was well maintained.

In addition, when a running test was conducted up to 50,000 prints using three-color overlapping development, no significant change was observed in the fixed image, and the image on the 50,000th print was also a bright image with no background smudges or shading. Also, the amount of charge on the 50,000th sheet is yellow developer + 1
3.9μc/g, magenta developer +11.0μc/g,
The cyan developer was +13.0 μc/g, and the charging was stable.

Example 2 Synthesis was carried out in the same manner as in Example 1 using 8 g of laurylamine instead of 1 g of stearylamine in Example 1, and a modified epoxy resin (hereinafter referred to as resin) with a softening point of 143°C and an N content of 0.14 weight 2 B) was obtained.

Next, using this resin B, yellow, magenta, and cyan color toners were prepared in the same manner as in Example 1. The formulation of each color toner is as follows.

Yellow toner formulation: Resin B 9
0 parts Polyester resin of resin example 1
10 parts Nord Yellow FGN-T
Part 5 TP-302 (manufactured by Hodogaya Chemical Industry Co., Ltd.)
1 part magenta toner formulation: Resin B 9
0 parts Polyester resin of resin example 1
10 parts Risnogen Magenta R 5 parts TP-3021 part Cyan toner Formula: Resin B 9
0 parts Polyester resin of resin example 1
10 parts Nord Blue FG-7351
2 parts TP to 3021 parts Next, 3.5 parts of each color toner was mixed with 96.5 parts of iron powder carrier (TEFV23 manufactured by Nippon Tetsuko Co., Ltd.) to prepare two-component developers for each color. When the charge amount of the obtained developer was measured by a blow-off method, it was found that the yellow developer was +15.
5 μc/g, magenta developer +12.9 μc/g, and cyan developer +14.8 μc/g.

When monochrome, two-color, and three-color superimposed images were formed using these developers, the single-color, two-color, and three-color superimposed full-color images had a clear average gloss level of 2.
A 0% fixed image was obtained. The minimum fixing temperature was 110°C, and the hot offset generation temperature was 190°C. In addition, in the three-cover solid image, there was almost no curling at the edges of the fixed image.

Furthermore, the projected image by OHP was clear, and there was no toner transfer to the vinyl chloride resin sheet. Even in a running test of up to 50,000 sheets of three-color overlay, no significant changes were observed in either image or charge.

Example 3 In Example 1, using 4 g of cyclohexylamine instead of stearylamine, synthesis was carried out in the same manner as in Example 1, and a modified epoxy resin (hereinafter referred to as Resin C ) was obtained.

Next, using this resin C, yellow, magenta, and cyan color toners were prepared in the same manner as in Example 1. The prescription is as follows.

Yellow toner formulation: Resin C 85 parts Polyester resin of Resin Example 4 15
Part Risnor Yellow FGN-T
5 parts Bontron P-51 (manufactured by Orient Chemical Industry Co., Ltd.) 2 parts Magenta toner formulation: Resin C' 85 parts Polyester resin of resin example 4 15 parts Lisunogen Magenta R 5 parts Bontron P-5 12 parts Cyan toner formulation: Resin C 85 parts Resin Polyester resin of Example 4 ■5
Bulisu Nord Blue FG-7351
2 parts Bontron P-51 2 parts Developers for each color were prepared, and images were similarly formed by monochrome, two-color superimposed, and three-color superimposed development, and clear fixed images with an average gloss level of 23m were obtained in all cases6. The lower limit fixing temperature was 100°C, and the hot offset generation temperature was 195°C. In addition, in the solid image of the three envelopes, there was almost no curling at the edges of the image, the OHP projection image was clear, and no transfer to the vinyl chloride resin sheet was observed.

Further, even in running tests of up to 50,000 sheets, no significant changes were observed in either image or charge.

Example 4 Synthesis was carried out in the same manner as in Example 1, using 5 g of octylamine instead of stearylamine,
A modified epoxy resin (hereinafter referred to as resin) having a softening point of 142°C and an N content of 0.14% by weight was obtained.

Next, yellow, magenta, and cyan color toners and color developers were prepared using this resin resin according to the same formulation as in Example 1, and images were similarly formed by monochrome, two-color overlapping, and overlapping development. A clear fixed image with an average gloss of 20% was obtained.

The lower limit fixing temperature was 100°C, and the hot offset generation temperature was 190°C. In addition, in the solid image of the three envelopes, there was almost no curling at the edges of the image, and the projected image by OHP was clear, and no transfer to the vinyl chloride resin sheet was observed.

Further, even in running tests of up to 50,000 sheets, no significant changes were observed in either image or charge.

Example 5 In Example 1, the reduced pressure was released, stearinamine was added, and after reacting for 5 hours, a Dean-Stark apparatus was attached.
Add 20g of stearic acid and 30ml of xylene,
An ester reaction was carried out at 0 to 190°C under xylene reflux for 6 hours to obtain a modified epoxy resin (hereinafter referred to as resin E) having a softening point of 143°C and a N content of 0.15% by weight.

Next, toners of yellow, magenta, and cyan and developers of each color were prepared using this resin E according to the same formulation as in Example 3, and images were similarly formed by monochromatic, two-color overlapping, and three-color overlapping development. , both have a clear average gloss level of 2
A 3% fixed image was obtained.

The minimum fixing temperature was 110°C, and the hot offset generation temperature was 195°C. In addition, in the solid image of the three envelopes, there was almost no curling at the edges of the image, and the projected image by OHP was clear, and no transfer to the vinyl chloride resin sheet was observed.

In addition, even in running tests up to 50,000 sheets, only one image was obtained.

No significant change in charge was observed.

Comparative Example 1 Yellow, magenta, and cyan color toners and color developers were made in the same manner as in Example 1, except that bisphenol A epoxy resin (R368, manufactured by Mitsui Petrochemicals) was used as it was without modification. . The charge amount of the obtained developer is yellow developer + 10.5 μc/g, magenta developer +
6.2 μc/g, cyan developer +8.5 μC/g. Using these developers, monochromatic and two-color
When images were formed by color overlapping and three-color overlapping development, the single-color image, two-color overlapping image, and three-color overlapping full-color image had a slight background smudge and the average gloss level was only 7. Of course, the full-color image was also poor. Furthermore, when a three-color superimposed uniform image was fixed on the entire surface, the entire image curled into a cylindrical shape.

However, there was no toner transfer to the vinyl chloride resin sheet.

In addition, when a running test was conducted using three-color overlapping development, the background smudge became severe after 1,000 sheets.

Transfer defects also occurred, and no image was formed after 1,600 sheets. When the amount of charge of the developer was measured at that stage, it was found that all three colors had negative polarity.

Comparative Example 2 Using the apparatus of Example 1, 250 g of bisphenol A epoxy resin, 130 g of bisphenol A, 50 g of xylene
- and heated to 70℃ under N3 atmosphere to 0.65N
An aqueous sodium hydroxide solution was added, and xylene was distilled off. After releasing the vacuum and reacting for 5 hours, ε-caprolactone 1
9.6g was added and the reaction was further carried out for 6 hours, and the softening point was 14.
An esterified modified epoxy resin at 0°C was obtained.

Next, using this resin, yellow,
When magenta and cyan color toners and color developers were prepared, the charge amount of the developer was yellow developer + 10.
6 μc/g, magenta developer +6.2 μc/g, and cyan developer +8.8 μc/g. Using these developers, images were formed by single-color, two-color overlapping, and three-color overlapping development in the same manner as in Example 1, and the average glossiness of the single-color image, two-color overlapping image, and three-color overlapping full-color image was 23%. A fixed image was obtained, but it was slightly smudged. The minimum fixing temperature was 110°C, but the hot offset was 1
It occurred at 80°C.

In a three-color overlapping full-surface solid image, there was almost no curling at the edges of the fixed image.

Further, there was no toner transfer to the vinyl chloride resin sheet.

However, when a running test using three-color overlapping was conducted, the background smudge became severe after 1,000 sheets, transfer defects also occurred, and no image was formed after 1,600 sheets. When the amount of charge of the developer was measured at that stage, all three colors had negative polarity.

Comparative Example 3 Using the apparatus of Example 1, 250 g of bisphenol A epoxy resin, 117 g of bisphenol A, 50 g of xylene
d was added, the temperature was raised under N2 atmosphere, 0.65N aqueous sodium hydroxide solution was added, and the temperature was then raised to 150°C, during which time xylene was distilled out and removed under reduced pressure.

After releasing the vacuum, add 1 g of stearinamine and heat to 185°C.
The reaction was carried out for 5 hours to obtain an amine-modified epoxy resin with a softening point of 142°C.

Next, using this resin, yellow,
When magenta and cyan color toners and color developers were prepared, the charge amount of the developer was yellow developer + 17.
2 μc/g, magenta developer +14.0 μc/g, and cyan developer +15.5 μc/g. Using these developers, images were formed by single-color, two-color overlapping, and three-color overlapping development in the same manner as in Example 1, and the average glossiness was 7% for single-color images, two-color overlapping images, and three-color overlapping full-color images.
Of course, it can be used as a single color image or a two-color overlapping image.
Even as a full-color image, it was poor. Furthermore, when a three-color superimposed uniform uniform image was fixed on the entire surface, the entire image curled into a cylindrical shape. There was no toner transfer to the vinyl chloride resin sheet.

In addition, when a running test was conducted up to 50,000 prints using three-color overlapping development, no significant change was observed in the fixed image, and the image on the 50,000th print was also a bright image with no background smudges or shading. Also, the amount of charge on the 50,000th sheet is yellow developer + 15
．． 8 μc/g, magenta developer +13.0 μc/g, cyan developer +14.0 μc/g, and charging was also stable.

Comparative Example 4 Using Resin A synthesized in Example 1, a toner was produced in the same manner as in Example (2). The prescription is as follows. The feed rate of the feeder during fine pulverization was only 150 g/hr.

Yellow toner formulation: Resin 100 parts Liosu Blue FGN-T 5 parts Magenta toner formulation: Resin A 100 parts Lionogen Magenta R 5 parts Cyan toner formulation: Resin A 100 parts Liosu Blue FG-7351 2 parts Example When monochromatic, two-color, and three-color images were formed using the developer in the same manner as in Example 1, the lower limit fixing temperature was 110°C, but hot offset occurred at 180°C.

〔Effect of the invention〕

As described above, the dry electrophotographic toner using the specific binder resin of the present invention has good color reproducibility, provides sufficient gloss in images fixed by heat roll fixation, and provides images fixed by heat roll fixation. No curling, stable positive charging, good compatibility with other resins, good dispersibility of dyes and pigments, good manufacturability (crushability), good fixing properties, and no transfer to PVC matte. is obtained.

Claims (2)

[Claims] (1) In a dry electrophotographic toner containing a colorant and a binder resin as main components, the binder resin reacts an epoxy resin with a primary amine and a dihydric phenol to extend the chain length of the epoxy resin. A toner for dry electrophotography, characterized in that it is a mixed system of a modified epoxy resin obtained by esterifying a secondary hydroxyl group with a lactone, and a polyester resin consisting of a bisphenol diol and a polyhydric carboxylic acid. (2) The toner for dry electrophotography according to claim (1), wherein the modified epoxy resin is 95 to 60 parts by weight, and the polyester resin is 5 to 40 parts by weight.