JPH06180511A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic toner not causing offsetting phenomenon or winding of paper at the time of fixation, hardly deteriorating its flowability and transferability and having satisfactory releasability by using a specified org. compd. as a releasing agent. CONSTITUTION:In an electrophotographic toner made of powdery particles contg. resin particles, a colorant, an electrostatic charge controlling agent and a releasing agent as essential components, a compd. represented by a formula R1-CONH-R2 (where each of R1 and R2 is 9-21C alkyl), e.g. N-caprylstearic acid amide, N-laurylcaprylic acid amide or N-myristylerucic acid is used as the releasing agent. By this compsn., the objective electrophotographic toner having 3-9mum volume average particle diameter and <=1.15 ratio of volume average particle diameter to number average particle diameter is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel electrophotographic toner excellent in releasability and transferability.

[0002]

2. Description of the Related Art Generally, in electrophotography, as a method of fixing a toner image on paper or the like, a pressure heating method using a heat roller is known. This method has good thermal efficiency and enables high-speed fixing, but on the other hand, since the surface of the heat roller and the toner are in contact with each other in a molten state under pressure, a part of the toner image adheres to the surface of the fixing roller and is transferred. It has a drawback that an offset phenomenon occurs that re-transposes to. In order to prevent this phenomenon, the surface of the fixing roller is made of silicone rubber or fluororesin, which has good releasability for toner
Further, a releasing liquid such as silicone oil is supplied to the surface thereof. This method is extremely effective in preventing the occurrence of offset development of toner, but in addition to the release liquid for offset prevention being heated and vaporized to give an unpleasant odor, the release liquid is also supplied. A device for doing so is required.

In recent years, toner has been required to have good low-temperature fixability in order to speed up copying and save energy, and for this reason, binder resins having a low softening point have been used. However, when the low softening point resin is contained in the toner, an offset phenomenon at the time of fixing and a so-called winding phenomenon in which the copy paper is wrapped around the surface of the heat roller are likely to occur.

Therefore, as means for preventing these phenomena, Japanese Patent Application Laid-Open Nos. 51-143333 and 57-14875.
No. 2, No. 58-97056, No. 60-247250 and the like, it is proposed to add various waxes such as solid silicone varnish, higher fatty acid and higher alcohol as a release agent, but at a good low temperature. At present, no release agent has been found that exhibits sufficient offset resistance and winding resistance while maintaining fixability.

On the other hand, in order to efficiently exhibit releasability and to impart releasability to a toner having a small particle size and a sharp particle size distribution, the above-mentioned releasing agent is externally added to the surface of the toner particles or It is already known to fix. For example, Japanese Unexamined Patent Publication No. 63-11955 discloses a method of mixing a toner and a low melting wax with a ball mill or the like and coating the toner surface with the low melting wax. Japanese Patent No. 54458 discloses a method of mixing a toner with a polyethylene resin or polyethylene fine powder. In these methods, the release agent adheres to a part of the toner surface, but in addition to this, Is due to the presence of released release agent,
There are drawbacks such as a weak effect of preventing the offset phenomenon and contamination of the photoconductor by the released release agent.

Further, in JP-A-63-41861, a method of mixing 2 μm of polypropylene with 8 μm of toner and bringing the toner into close contact with the surface under heat and pressure, and JP-A-63-244
Japanese Patent No. 053 proposes a method of fixing releasable particles having a particle size ratio of 0.2 or less with respect to the toner on the surface by mechanical impact. However, in order to fix the release agent to the toner particles so as not to generate a free release agent, the particle size of the release agent needs to be 1/10 or less of the toner particle size. The method of No. 41881 is not sufficient. Further, low molecular weight polypropylene and low molecular weight polyethylene which are generally used for toner are not pulverized by a generally known method,
Therefore, for example, as described in JP-A-63-244053, a method has been proposed in which these are once dissolved in a solvent and precipitated in a solvent-containing solution. However, although this method produces a finely divided particulate product, it has the drawback that aggregates are formed and remain in the toner without being crushed. A method using heating spray is also known, but the size of this method is limited to several μm at most. Thus, under the present circumstances, low molecular weight polyolefins cannot be obtained in the form of fine particles. In order to solve these problems, JP-A-63-300245 proposes to use a finely divided emulsion wax and attach a release agent to the toner surface in a wet process, which is disclosed here. Although a general releasing agent that is used exhibits the effect of releasability, the fluidity of the toner and the transferability from the photoreceptor to the paper are deteriorated, which causes a problem in actual use.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, 1) prevents an offset phenomenon and paper wrapping during fixing, and 2) does not deteriorate fluidity and transferability. 3) An object of the present invention is to provide an electrophotographic toner having excellent characteristics such as a small particle size, a sharp particle size distribution, and good releasability.

[0008]

According to the present invention, an electrophotographic toner comprising powder particles containing resin particles, a colorant, a charge control agent and a release agent as main components is used as the release agent. An electrophotographic toner comprising the compound represented by the following general formula 1 is provided.

Embedded image R ₁ -CONH-R ₂ (wherein R ₁ and R ₂ represent an alkyl group having 9 to 21 carbon atoms, and R ₁ and R ₂ may be the same or different). According to the present invention, the spherical particles are characterized by having a volume average particle diameter Dv of 3 to 9 μm and a ratio Dv / Dp of the volume average particle diameter Dv and the number average particle diameter Dp of 1.15 or less. An electrophotographic toner is provided.

Specific examples of the compound represented by the general formula 1 used as a release agent in the present invention include, for example, N-capryl stearic acid amide, N-lauryl capric acid amide, and N-oleyl lauric acid amide. , N
-Myristyl myristate amide, N-palmethylstearate amide, N-behenyl palmitate amide, N
-Stearyl stearic acid amide, N-stearyl oleic acid amide, N-stearyl erucic acid amide, N-oleyl stearic acid amide, N-oleyl ricinoleic acid amide, N-oleyl oleic acid amide, N-oleyl paltic acid amide, N -Behenyl isostearic acid amide, N-12 hydroxystearyl adipic acid, N-stearyl behenic acid, N-palmethyl sebacic acid, N-myristyl erucic acid and the like can be mentioned. These release agents are preferably used in the range of 0.5 to 5.0% with respect to the resin particles.

As the resin particles used in the present invention, various conventionally known thermoplastic resins can be widely used. Examples thereof include styrene, parachlorostyrene, vinyltoluene, vinyl chloride, vinyl acetate and prepion. Vinyl acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) allylate, isobutyl (meth) acrylate, dodecyl (meth) acrylate, (meth) 2-ethylhexyl acrylate, lauryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid 2
-Hydroxypropyl, 2-chloroethyl (meth) acrylate, (meth) acrylonitrile, (meth) acryamide, (meth) acrylic acid, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl methyl ketone, N-vinyl pyrrolidone, Examples thereof include polymers of monomers such as N-vinylpyridine and butadiene, copolymers of two or more kinds of these monomers, or a mixture thereof. Other polyester, polyurethane, polyamide, epoxy resin, rosin, modified rosin,
Terpene resins, phenol resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, etc. can be used alone or in combination.

The coloring agents used in the present invention include the following. Black pigments: carbon black (oil furnace black, channel black, lamp black, acetylene black, etc.); azine dyes such as aniline black, metal salt azo dyes, metal oxides, complex metal oxides. Yellow pigment: Cadmium yellow, mineral fast yellow, nickel titanium yellow, navels yellow,
Naphthol Yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow GR, Quinoline Yellow Rake, Permanent Yellow NCG, Tartrazine Rake. Orange pigments: molybdenum orange, permanent orange GTR, pyrazolone orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK. Red pigments: red iron oxide, cadmium red, permanent red 4R, resole red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, brilliant carmine 3B. Purple pigment: fast violet B, methyl violet lake. Blue Pigment: Cobalt Blue, Alkali Blue, Victoria Blue Lake, Phthalocyanine Blue, Metal-Free Phthalocyanine Blue, Phthalocyanine Blue Partial Chloride,
First Sky Blue, Indren Sren Blue BC. Green pigments: chrome green, chrome oxide, pigment green B, malachite green lake, and oil-soluble dyes and disperse dyes can be used when coloring by dyeing, and in this case, these are 1 type or 2 types.
A mixture of two or more species can be used.

Further, examples of the charge control agent in the present invention include the following. Nigrosine, an azine dye containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42
-16627), basic dyes (for example, C.I.B.
asic Yellow 2 (C.I. 41000),
C. I. Basic Yellow 3 (CI Bas
ic Red 1 (C.I. 45160), C.I. I. B
asic Red 9 (C.I. 42500), C.I.
I. Basic Violet 1 (CI.4253
5), C.I. I. Basic Violet 3 (C.
I. 42555), C.I. I. Basic Violet
10 (C.I. 42170), C.I. I. Basic
Violet 14 (C.I. 42510), C.I. I.
Basic Blue 1 (C.I. 42025), C.I.
I. Basic Blue 3 (C.I. 5100
5), C.I. I. Basic Blue 5 (C.I.4
2140), C.I. I. Basic Blue 7 (C.I.
I. 42595), C.I. I. Basic Blue 9
(C.I. 52015), C.I. I. Basic Blu
e24 (C.I. 52030), C.I. I. Basic
Blue 25 (C.I. 52025), C.I. I. Ba
sic Blue 26 (C.I. 44045), C.I.
I. Basic Green 1 (C.I. 4204
0), C.I. I. Basic Green 4 (C.I.
42000), lake pigments of these basic dyes,
C. I. Solvent Black 8 (C.I. 2
6150), quaternary ammonium salts such as benzoylmethyl-hexadecyl ammonium chloride and decyl trimethyl chloride, or dialkyl lead compounds such as dibutyl or dioctyl, dialkyl lead borate compounds,
Polyamine resins such as guanidine derivatives, amino group-containing vinyl polymers and amino group-containing condensation polymers, JP-B-41-20153 and 43-27596
Nos. 44-6397 and 45-26478, metal complex salts of monoazo dyes, JP-B-55-42
No. 752, Japanese Patent Publication No. 59-7385, salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Cr, Fe and other metal complexes,
Sulfonated phthalocyanine pigment, etc.

As a method for producing the toner of the present invention,
A method of kneading and pulverizing the above-mentioned thermoplastic resin particles, a colorant, a charge control agent and a release agent and a method of suspension polymerization with a monomer are also effective, but in order to obtain a toner having a sharp particle size distribution and a small particle size. It is preferable that the polymer particles obtained by the dispersion polymerization method are colored and then surface-treated with a release agent.

[0014]

EXAMPLES The present invention will be described below with reference to examples.

Example 1 Styrene / methyl acrylate copolymer 100 parts by weight (copolymerization ratio 55/45) carbon black 10 parts by weight N-oleyllauric acid amide 5 parts by weight 3,5, ditertiary butyl salicylate zinc complex 5 Parts by weight The mixture consisting of the above is kneaded by heating and kneading with a hot roll,
A black powder having a volume average particle size of 9 μm was obtained by classification. Colloidal silica 0.3 is added to 100 parts by weight of the powder particles.
Parts were added and mixed to obtain the toner of the present invention. 3 parts by weight of this toner was mixed with 100 parts by weight of an iron powder carrier to prepare a two-component developer. This developer is placed in a magnetic brush developing device to develop the electrostatic latent image formed on the organic photoconductor by a normal electrophotographic method, and this is transferred onto plain paper while corona discharge is applied. When it is heat-fixed with a fixing roller not supplied, the fixing temperature is 150 to 210 ° C.
There is no paper winding or offset phenomenon in the range of
A good image was obtained.

Comparative Example 1 A comparative toner was obtained in the same manner as in Example 1 except that low molecular weight polypropylene was used in place of N-oleyllauric acid in Example 1. This toner is then used in Example 1.
When the image was set in the same apparatus as described above and the image was printed, paper wrapping occurred at a fixing temperature of 170 ° C. or less.

Example 2 70 parts by weight of styrene, 30 parts by weight of n-butyl methacrylate, 10 parts by weight of carbon, and a metal-containing azo dye (S-34, manufactured by Orient Chemical Co.) were used in an amount of 2% of polyvinyl alcohol.
It was uniformly dispersed in an aqueous solution using a homogenizer, and suspension polymerization was carried out using 2 parts by weight of azobisisobutylnitrile to obtain powder particles. Further, fine powder portions and coarse powder portions were cut from the powder particles to obtain black particles having an average particle diameter of 8 μm. 100 parts by weight of the above black particles are dispersed in water and N-palmethylstearic acid amidono emulsion (solid content 2
0%, 10 parts by weight of average particle diameter 0.18 μm) was added, and 20 ml of a 1% stearylamine acetate aqueous solution was added with stirring.
Was added dropwise, N-palmethylstearic acid amide was attached to the surface of the black particles, and the resultant was filtered and dried to obtain the toner of the present invention. Next, 3 parts by weight of this toner was mixed with 100 parts by weight of an iron powder carrier to prepare a two-component developer. This developer is set in the same apparatus as in Example 1, and the fixing temperature is set to 150.
When copying was performed every 10 ° C. in the range of up to 210 ° C., a clear image was obtained without offset phenomenon and paper wrapping at each temperature.

Example 3 60 parts by weight of styrene, 30 parts by weight of 2 ethylhexyl methacrylate, and 10 parts by weight of butyl acrylate were copolymerized in a methyl alcohol solvent in the presence of polyvinylpyrrolidone as a dispersion stabilizer to give an average particle size of 6 μm. As a result, spherical powder particles having a narrow particle size distribution (Dv / Dp of 1.09) were obtained. Next, 100 parts by weight of the powder particles are dispersed in 400 parts by weight of methyl alcohol, and 4 parts by weight of oil black 860 (manufactured by Orient Chemical Co., Ltd.) and 1 part by weight of Macrolex Orange R (manufactured by BATER) while stirring at room temperature. Was added and stirred for 8 hours for dyeing to obtain black particles. 100 parts by weight of the black particles are dispersed in a water-methanol mixed solvent,
Perfluoroalkyltrimethylammonium salt 10
% 20% aqueous solution and 4 parts of N-ztearyl stearic acid amide emulsion (solid content 25%, average particle size 0.12 μm) are added with stirring to attach N-stearyl stearic acid amide to the surface of black particles, It was filtered and dried to obtain the toner of the present invention. Next, 3 parts by weight of this toner was mixed with 100 parts by weight of an iron powder carrier to prepare a two-component developer. When this developer was set in a digital copying machine to perform copying, the transfer rate from the photoconductor was 93%. In the fixing temperature range of 150 to 210 ° C., a black image excellent in dot reproducibility without offset phenomenon was obtained. 5 more
After repeatedly copying ten thousand sheets, there was no contamination on the photoreceptor or carrier, and clear copy images were obtained without any offset phenomenon or paper wrapping.

[0019]

As can be seen from the above, the electrophotographic toner of the present invention has the following excellent characteristics. (1) No offset phenomenon occurs during fixing, and paper is not wrapped around the fixing roller. (2) It has a small particle size and a sharp particle size distribution, and exhibits high quality and high durability. (3) Good transferability from the photoconductor to paper and excellent releasability.

Claims (2)

[Claims] 1. A toner for electrophotography comprising powder particles containing resin particles, a colorant, a charge control agent and a release agent as main components, wherein the release agent is a compound represented by the following general formula 1. A toner for electrophotography, characterized by using. ## STR1 ## R ₁ --CONH--R ₂ (In the formula, R ₁ and R ₂ represent an alkyl group having 9 to 21 carbon atoms, and R ₁ and R ₂ may be the same or different.) 2. The volume average particle diameter Dv3 of the powder particles.
The toner for electrophotography according to claim 1, which is composed of spherical particles having a volume average particle diameter Dv to a number average particle diameter Dp of Dv / Dp of 1.15 or less.