JPS6030939B2 - Toner for developing electrostatic images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, and the like.

Methods for developing electrostatic images are roughly divided into liquid development methods that use a developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, cascade methods, bristle brush methods, magnetic brush methods, and insulating brush methods. There are two types of dry development methods, such as the compression method and the powder cloud method, which use a fine powder developer called a toner in which a coloring agent such as carbon black is dispersed in a natural or synthetic resin. The present invention relates to a toner used in a dry development method.

After developing an electrostatic charge image using toner, fixing is performed, and generally speaking, fixing involves directly transferring the toner image obtained by development onto a photoconductive photoreceptor or electrostatic recording medium that carries the electrostatic charge image. By fusing or by transferring the toner image obtained by development from a photoconductive photoreceptor or electrostatic recording medium onto a transfer sheet such as carrier paper, and then fusing this onto the transfer sheet. It is done. that time,
The toner image is fused by either contact with solvent vapor or heating, and the heating methods include a non-contact heating method using an electric furnace and a pressure bonding heating method using a heated lo-fu.
Generally adopted. The pressure heating method using a heating roller performs fixing by passing the toner image surface of the sheet to be fixed through pressure contact with the surface of a heating roller whose surface is made of a material that has releasability for toner. Generally referred to as the heating roller fixing method, this method brings pressure contact between the surface of the heating roller and the toner image surface of the fixing sheet, so the thermal efficiency of fusing the toner image onto the fixing sheet is extremely high. Since it is highly effective and can perform fixing quickly, it is extremely effective particularly in transfer-type electrophotographic copying machines intended for high-speed copying. For example, in general, the thermal efficiency of a normal electric furnace type fixing device is about 10 to 40%, and the thermal efficiency of a side radiation type fixing device is about 20%.
%, whereas the thermal efficiency of the roller fixing device is 8.
It is said to be around 0%. Needless to say, if the thermal efficiency is to be further increased, it is necessary to further reduce the thickness of the coating film on the surface of the roller made of a material having mold releasability. By the way, in the heated roller fixing method, the surface of the fixing roller and the toner image come into pressure contact in a heated and molten state, so a part of the toner image adheres to the surface of the fixing roller and is transferred, and then transferred again onto the next sheet to be fixed. This causes a so-called offset phenomenon and causes the sheet to be fixed to be stained.

Therefore, one of the essential requirements in the heating roller fixing method is to prevent toner from adhering to the surface of the roller. Conventionally, in order to prevent toner from adhering to the surface of the fixing roller, for example, the roller surface is made of a material that has excellent patterning properties for toner, such as fluorine-based resin, and the surface is also coated with offset prevention material such as silicone oil. It is practiced to supply a liquid to coat the surface of the roller with a thin film of liquid. Although this method is extremely effective in preventing toner offset, it generates an odor due to heating of the offset prevention liquid and requires a device to supply the offset prevention liquid. However, since the mechanism of the copying machine becomes complex and high precision is required to obtain stable results, the copying machine becomes expensive.

However, if the anti-offset liquid is not supplied, toner will adhere to the surface of the fixing roller and an offset phenomenon will occur, so despite having these runner-up points, it is currently necessary to supply the anti-offset liquid. It is. An object of the present invention is to provide an electrostatic charge image that can be efficiently and effectively fixed by a heated roller without causing toner offset even when a fixing roller that does not supply an anti-offset liquid to the surface of the fixing roller is used. The purpose of the present invention is to provide developing toner.

The present inventor has provided a toner for developing an electrostatic image containing a colorant, a styrene resin, a monofatty acid ester or a partially saponified product thereof, and a Q paraffin or a bisfatty acid amide, which achieves the above object. I found that. By using the electrostatic image developing toner according to the present invention, efficient and effective heating roller fixing can be performed without causing an offset phenomenon even when no offset prevention liquid is supplied to the fixing roller surface. Therefore, the mechanism of the fixing device can be simplified, and
For example, the accuracy, stability, and reliability of a high-speed copying machine incorporating such a fixing device can be improved, and the cost can also be reduced.

Therefore, it has the advantage of making the design of an ultra-high speed copying machine extremely easy.

Any suitable pigment or dye can be used as a colorant in the toner according to the invention.

For example, carbon black, nigrosine dye, aniline blue, oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal and mixtures thereof. They need to be included in the toner in an amount sufficient to color the toner so that it can be developed to form a visible image. In the toner according to the present invention, a styrene resin is used as a resin component. The styrene resin may be a styrene homopolymer or a copolymer of styrene and other vinyl monomers. Monomers for forming these polymers include p-chlorostyrene, pinylnaphthalene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobuterene, such as vinyl chloride, vinyl propionate, and vinyl bromide. , vinyl esters such as vinyl fluoride, vinyl acetate, vinyl benzoate, vinyl butyrate, such as methyl acrylate, isobutyl acrylate, ethyl acrylate, n-butyl acrylate, dodecyl acrylate, n-octyl acrylate, acrylic acid 2-chloroethyl, phenyl acrylate, Q-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate,
Butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, phenyl methacrylate, tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate , esters of Q-methylene aliphatic monocarboxylic acids such as 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, dietylaminoethyl methacrylate, glycidyl methacrylate, and tetrahydrofurfuryl methacrylate; Acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isoprobenyl ketone, such as N-vinylpyrrole, N Examples include N-vinyl compounds such as -vinylcarbazole, N-vinylindole, and N-pinylpyrrolidone, and one or more of these can be copolymerized with a styrene monomer.

Suitable styrenic resins have a weight average molecular weight of about 30,000 or more and have a styrene content of at least about 25% by weight based on the total amount of styrenic resin.
It is preferable that A thermoplastic resin system in which a styrene resin is mixed with other resins can also be used as the resin component of the toner according to the present invention.

Other resins that can be mixed with styrenic resins include:
Vinylnaphthalene, such as vinyl chloride, vinyl bromide,
Pynyesters such as vinyl fluoride, vinyl acetate, vinyl propionate, pinyl benzoate, vinyl butyrate; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; such as methyl acrylate, isobutyl acrylate, Ethyl acrylate, n-butyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl Q-chloroacrylate,
Methyl methacrylate, ethyl methacrylate, butyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, phenyl methacrylate, tridecyl methacrylate, stearyl methacrylate, methacrylate Cyclohexyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, jetylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, etc. Esters of Q-methylene aliphatic monocarboxylic acids, acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, such as vinyl methyl ketone, vinyl hexyl ketone, methyl isoprobenyl ketone Homopolymers obtained by polymerizing monomers such as vinyl ketones such as N-vinyl compounds such as N-vinylpyrrole, N-vinylcarnozole, N-vinylindole, and N-vinylpyrrolidene, or two or more of these monomers. Examples include copolymerized polymers and non-vinyl thermoplastic resins such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, polyamide resins, polyacetal resins, cellulose resins, and polyether resins. When these resins are used in combination with styrenic resins, at least about 25% by weight based on the total weight of the resulting resin
Preferably, the two are mixed in such an amount that % of the styrene component is present. This is because the releasability of the toner from the fixing roller is closely related to the amount of styrene component present, and as the styrene component is reduced, the releasability of the toner from the fixing roller tends to decrease. Further, as a toner resin, one of the physical properties preferable for roller fixing is viscoelasticity in the rubbery region at the fusing temperature of the toner.

This viscoelasticity is mainly based on the structure and molecular weight distribution of the toner resin. The effective creep modulus of the rubbery region in roller fixing without adding an anti-offset liquid to the roller surface is suitably between 1 and 1 pid skin e/. If the creep modulus is less than this value, there will be a portion that is fixed onto the transfer paper during melting and a portion that is torn off by the fixing roller and remains, and an offset phenomenon is likely to occur. In order to prevent the offset phenomenon, a large amount of a substance that imparts mechanical properties may be added to the toner, but even if only the offset phenomenon can be prevented, other properties required of the toner are impaired, which is not preferable. Furthermore, if the creep modulus value is above the above range, the degree of fixation is poor and the image tends to peel off from the transfer paper. Of course, in this case, it would be better to further raise the fixing temperature, but this would exceed the heat resistance limit of the roller material, which is not preferable. The fatty acid ester or partially saponified product thereof used in the toner of the present invention is an ester obtained by reacting a saturated or unsaturated fatty acid with a saturated or unsaturated aliphatic alcohol, or a ester obtained by reacting a saturated or unsaturated fatty acid with a saturated or unsaturated fatty alcohol. It is obtained by partially saponifying metals such as calcium, magnesium, lead, aluminum, barium, and zinc with hydroxides.

The fatty acids as raw material components may be either lower or higher, such as valeric acid, caproic acid, henanthic acid, caprylic acid, belargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, bentadecylic acid, Palmitic acid, margaric acid, stearic acid, nondecylic acid, arahinic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melisic acid,
Hentriacontanonic acid, dotriacontanonic acid, tetratriacontanonic acid, hexatriacontanonic acid, octatriacontanonic acid, tuccinic acid, Linderic acid, lauroleic acid, zuzuic acid, myristoleic acid, zomarinic acid, Vetroceric acid, oleic acid, elaidic acid, vaccenic acid, gadolenic acid, ersic acid, brassic acid, ceracoleic acid, linoleic acid, linolenic acid, eleostearic acid, linoleridic acid, valinaric acid, arachidonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid,
Azelaic acid, sebacic acid, other carbon atoms 9-19
Examples include dicarboxylic acids having a methylene group. The aliphatic alcohols as other raw material components may be either lower or higher like fatty acids, and may be monohydric or polyhydric alcohols, such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, etc. Alcohol, amyl alcohol, caproyl alcohol, caprylyl alcohol, caprylic alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachyl alcohol, behenyl alcohol, lunabil alcohol, ceryl alcohol, coryyl alcohol, myristyl alcohol sil alcohol, merisyl alcohol,
Laceryl alcohol, allyl alcohol, crotyl alcohol, 2-butenol-1, 2-bentenol-1
, 3-hexenol-1, 2-heptenol-1, 10
-Undecenol-1, 11-Dodecenol-1, 12
-tridecenol-1, oleyl alcohol, elaidyl alcohol, linoleyl alcohol, linolenyl alcohol, ethylene glycol, propylene glycol,
trimethylene glycol, 1,3-butanediol, 1
, 4-butanediol, 2,3-butanediol, 2-
Butene-1,4-diol, 1,5-bentanediol, 2,4-bentanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-1,3-
Pentanediol, 2,4-hebutanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-2-butyl-1,3-propanediol, hexadecane-1,
2-diol, octadecane-1,2-diol, eicosane-1,2-diol, docosane-1,2-dio-
Examples include diol, tetracosane-1,2-diol, -diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, glycerin, bentaerythritol, and sorbitol. However, when either the fatty acid or the aliphatic alcohol is lower grade, those in which the other is higher are particularly well suited for use in the present invention. In other words, among these esters composed of fatty acids and aliphatic alcohols, fatty acids with a total number of carbon atoms of 5 or more are desirable, and esters with a total number of carbon atoms of 20 or more are particularly preferred. Gives good results in invention. In the present invention, these fatty acid esters or partially saponified products thereof may be used alone, or a mixture consisting of a mixture of various fatty acid esters, or fatty acid esters and partially saponified products thereof may be used. You may use it as a mixture consisting of a composition mixed with.

In the present invention, commercially available fatty acid esters or partially saponified products thereof can be effectively used, and many of these commercially available products have the composition of a mixture as described above. Typical commercially available products include the following. Lower fatty acid alcohol ester butyl stearate (manufactured by Oilken Fine Chemical Co., Ltd.) Butyl stearate (manufactured by Kao Soap Co., Ltd.) Polyhydric alcohol ester of fatty acid Nissan Castor Wax-A (manufactured by Nihon Yushi Co., Ltd., glycerol tri-1,2-hydroxystearate) rate) Diamond wax (manufactured by Shin Nippon Rika Co., Ltd.) Castor hard oil (manufactured by Ken Fine Chemical Co., Ltd.) Higher alcohol ester of fatty acids spam acetate (manufactured by Nihon Yushi Co., Ltd., cetyl palmitate)
Hoechst Wax-E (manufactured by Hoechst Japan Co., Ltd., ethylene glycol ester of montanic acid) Hoechst Wax-OP (manufactured by Hoechst Japan Co., Ltd., partially saponified product of butylene glycol ester of montanic acid) Partial ester monoglycium of fatty acid and polyhydric alcohol M (manufactured by NOF Corporation, Q
-glycerol monostearate) Fatty acid monoglyceride R-60 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., stearic acid monoglyceride) Fatty acid monoglyceride R-80 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., oleic acid-stearic acid monoglyceride) Rikemar-S-200 (Riken Vitamin Made by Yusha,
Glycerin stearate) Rikemar-B-100 (manufactured by Riken Vitamin Oil Co., Ltd., glycerin monobehenate) Rikemar-S-300 (manufactured by Riken Vitamin Oil Co., Ltd., sorbitan monostearate) Rikemar-PS-100 (manufactured by Riken Vitamin Oil Co., Ltd.) , propylene glycol monostearate)
ATMUL-T-95 (manufactured by Kao Atlas Co., Ltd., high-purity monoglyceride) mixed ester VLTN-4 (manufactured by 0ll Ken Fine Chemical Co., Ltd.) VLT
-L Oilken Fine Chemical Co., Ltd.) K-3Wax (
Rice wax (manufactured by JIIken Fine Chemicals Co., Ltd.) (manufactured by Noda Wax Co., Ltd.) The aforementioned fatty acid ester or its partially saponified product used in the toner of the present invention must be as compatible as possible with the styrene resin component. desirable.

Various melting point values, for example 25 to 130q0, can be used satisfactorily, but in general, those with low melting points may adhere to the carrier, reduce triboelectric charging properties, and shorten the life of the developer. Because of this, the amount added cannot be increased too much and the amount added is likely to be limited, so those having a relatively high melting point, for example, those having a melting point of 70 to 10 points, are particularly desirable for use in the present invention. The amount of fatty acid ester or its partially saponified substance to be contained in the toner varies depending on the resin components of the toner, the types of colorants and toner additives, and their usage amounts, but is generally 0.5 parts by weight per 10 parts by weight of the resin components of the toner. -20 parts by weight, preferably 1-1 parts by weight. In order to incorporate the fatty acid ester or its partially saponified product into the toner, it may be added during premixing of the resin component, colorant, and various toner additives prior to the cross-mixing step. Fatty acid ester or its partially saponified product exhibits a low viscosity liquid state when heated, so when a toner containing this comes into contact with a heated fixing roller, the fatty acid ester or its partially saponified product in the toner liquefies and forms a liquid on the toner surface. It is thought that the melted toner is released and coats the surface of the fixing roller, and the releasing property of the fatty acid ester or its partially saponified product prevents the fused toner from adhering to the surface of the fixing roller, thereby preventing an offset phenomenon. Such a mold release effect is observed not only in a fixing roller whose surface is formed of a template-like material, but also when a fixing roller whose surface is formed with a metal, which is generally considered to have no mold release properties, is used.

Therefore, if the toner according to the present invention is used, it is possible to prevent the toner offset phenomenon even without using a fixing roller whose surface is made of a releasable material, which is extremely advantageous in terms of device design. The effects of adding fatty acid esters or partially saponified fatty acid esters to toners include improving the patternability as described above, as well as improving the dispersibility of colorants such as nigrosine and other additives contained in the toner, thereby increasing the charge of toner particles. It also has the effect of making the controllability uniform and improving the performance as a phenomenon agent. The toner according to the present invention further contains various compounds having a releasing effect other than the fatty acid ester or its partially saponified product in combination with the fatty acid ester or its partially saponified product.

These compounds include natural or synthetic paraffins, bis fatty acid amides such as ethylene bisstearamide, etc.
It can be contained in one species or in combination of two or more.

The amount of these compounds added to the toner is generally about 0.1 to 1 part by weight, preferably 0.5 to 5 parts by weight, per 10 parts by weight of the resin component of the toner. By adding it, the compatibility of the fatty acid ester or partially saponified fatty acid ester with the resin component is further improved, and the dispersibility of other toner additives such as colorants and charge control agents is also further improved. In addition, when the resin component has relatively brittle properties, it is possible to prevent excessive pulverization in the pulverization process during toner production.
Furthermore, the stability of the toner is increased, and the triboelectric charging property does not change even during long-term use, and the life of the toner can be significantly extended. Note that various other toner additives may be added to the toner according to the present invention as required. The toner image formed on the fixing sheet using the toner according to the present invention can be efficiently produced without causing toner offset even when a fixing roller that does not supply an anti-offset liquid to the surface of the toner image is formed on the fixing sheet. Effective heating roller fixing can be performed.

The surface of the fixing roller can be made of, for example, Teflon (manufactured by DuPont), Fluon (manufactured by ICI), KEL-F (manufactured by ICI), etc.
Fluorine resin such as KE-1300RT (manufactured by M Company) or KE-1300RT
V (manufactured by Shin-Etsu Chemical Co., Ltd.), PRX-305 (manufactured by Toray Industries, Inc.) that have a smooth surface made of vulcanized silicone rubber, and in some cases, those that have a metal surface such as hard chrome are effective. used for. Next, the present invention will be illustrated by examples, but the embodiments of the present invention are not limited thereto.

In the examples, the number of parts is expressed by weight unless otherwise specified. Example 1 10 parts of Picolastic D-150 (manufactured by Esso Petrochemical Co., Ltd., styrenic resin), 5 parts of Peerless 155 (manufactured by Columbia Carbon Co., Ltd.), 3 parts of Nigrosine Base EX (manufactured by Orient Chemical Co., Ltd.), and Hoechst wax. 3 parts of OP (manufactured by Hoechst Japan Co., Ltd., montanic acid butylene glycol ester) and 3 parts of Plastoflo (manufactured by Nitto Kagaku Co., Ltd., ethylene bisstearamide) were mixed and subjected to a ball mill for about 2 hours, and then heated with a hot roll. The toner was kneaded using the powder, cooled, and then ground to produce a toner having an average particle size of about 13 to 15 microns, which was used as a sample.

Further, a toner was prepared as a comparative sample by the same procedure as above except that Blast Flow and Hoechst Wax OP were not added.

These two types of toner are used to make the surface of the fixing roller.
A material made of E-1 TV (manufactured by Shin-Etsu Chemical Co., Ltd., silicone rubber) was used, and the fusion temperature was set at 160 to 185 pm.

4 parts of each toner were mixed with 196 parts of iron powder carrier having an average particle size of about 50 to 80 microns to form two developers, and these developers were used to form an electrostatic charge by conventional electrophotographic methods. After developing the image, the toner image was transferred onto a transfer paper and brought into pressure contact with the fixing roller to fuse and fix the toner image. Next, in order to investigate whether the fused toner image is transferred to the surface of the fixing roller and an offset phenomenon occurs, after each fixing operation, the transfer paper without toner image was transferred to the fixing roller under the same conditions as above. The offset properties of each toner were investigated by bringing them into pressure contact and observing the dirt generated by toner offset on the transfer paper.

As a result, it was found that when the comparative sample toner was used, a significant toner offset phenomenon occurred, but when the sample toner was used, no offset phenomenon occurred at all. Furthermore, it was found that the sample toner was less likely to be over-pulverized during pulverization during toner production.

This makes it difficult for toner filming to occur on the surface of the photoreceptor and for the carrier in the developer to be vented, thereby prolonging the life of each of them. Example 2 In Example 1, 3 parts of Hoechst Wax OP was replaced with 3 parts of Hoechst Wax E, and 3 parts of Plastflow was replaced with 3 parts of Sasol Wax Day 1 (manufactured by Sasol Marketing Co., Ltd., high melting point synthetic paraffin wax). A toner was prepared using the same procedure as in Example 1 and used as a sample.

Furthermore, a toner was prepared as a comparative sample by the same procedure as above except that Sasol Wax HI and Hoechst Wax E were not added.

Using these three types of toners, the same operations as in Example 1 were performed to examine the offset properties of each toner.

As a result, it was found that a significant toner offset phenomenon occurred when the comparative sample toner was used.
When the sample toner was used, it was found that no toner offset phenomenon occurred.

Claims (1)

[Claims] 1. An electrostatic charge image for heat roller fixation, characterized by containing (a) a colorant, (b) a styrene resin, (c) a fatty acid ester or a partially saponified product thereof, and (d) paraffin or a bis-fatty acid amide. Toner for development.