JPS6159349A - Toner - Google Patents

Abstract

PURPOSE:To obtain an excellent toner having an improve uniform dispersibility of fine grains and a stabilized frictional electrifiction and which is uniformly charged and does not occur an offset developing by dispersing the fine grains of such as the pigment contg. a nonionic surface active agent in a binding resin. CONSTITUTION:The toner is prepared by incorporating the fine grains of such as copper phthalocyanine pigment and a metal oxide with an aqueous soln. of the nonionic surface active agent such as polyoxyethylene nonylphenol and a various kinds of alkylolamide of fatty acid and kneading the obtd. fine grains contg. the nonionic surface active agent with the binding resin while heating and cooling, pulverizing and classifying, thereby obtaining the above mentioned toner having an excellent endurance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner used in electrophotography, electrostatic recording, etc.

[Prior Art] Electrophotography is described in US Pat. No. 2,297,1391;
British Patent No. 1185408 and British Patent No. 11
Although a number of methods are known, such as those described in U.S. Pat. The image is developed using toner, and the toner image is transferred to a transfer material such as paper if necessary, and then fixed by heat, pressure, solvent vapor, etc. to obtain a copy.

The electronic printing method is a method of guiding and fixing charged powder toner onto a recording material using an electric field to print.

Electrostatic recording is a method in which a charge is applied to an image on a dielectric layer, and charged toner powder is attached to and fixed on the image. Similarly, magnetic printing is a method in which a magnetic latent image is formed on a recording material. This is then developed with toner powder containing a magnetic material, transferred to a transfer material, and fixed.

Various developing methods are known in which such electrical and magnetic latent images are visualized using toners, but the toners used in these developing methods have conventionally been made by containing dyes or pigments in natural or synthetic resins. A fine powder in which fine particles such as the following are dispersed is used. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and pulverizing the particles to about 1 to 30 JL are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

These toners require different physical and chemical properties. However, many of the known toners have several deficiencies as described below. That is, the triboelectric properties of many toners are adversely affected by changes in environmental humidity. In addition, with many toners, the density of the resulting image decreases due to mutual deterioration of the toner, carrier particles, and photosensitive plate due to collisions between toner particles and carrier particles due to repeated development due to continuous use, and contact between these particles and the surface of the photosensitive plate. changes,
Alternatively, the background density increases, reducing the quality of the copy.

Furthermore, with many toners, if an attempt is made to increase the density of a copied image by increasing the amount of toner adhering to the surface of a photosensitive plate having a latent image, the background density usually increases, resulting in a so-called fog phenomenon. Many of the known toners have one or more of the following deficiencies, and there is a continuing need for improved toners.

Recently, the purposes for which the above-mentioned electrophotography is used are diverse, and there is a need for a compact and inexpensive color copying machine that can produce images in desired colors as needed, and there is an urgent need to develop toner for this purpose. be. In this sense, toners for color copying need to have excellent physical and chemical properties that overcome the above-mentioned defects, and it is also essential that the toner has a good hue.

However, when conventional dyes and pigments and substances known as charge control agents are used as toner materials, all properties such as hue, charge controllability, environmental dependence, heat resistance, light resistance, fixing properties, and cleaning properties are maintained. None of them were completely satisfactory and had some drawbacks.

For example, when a dye is used as a coloring agent, it is easy to obtain a clear hue, but it has the following drawbacks. That is, they generally have poor heat resistance and light resistance, and have a strong tendency to discolor or fade due to heat kneading during toner production, exposure of the obtained image to artificial light, or long-term storage under outdoor exposure.

Furthermore, when the developer is stored at a relatively high temperature, the toner tends to aggregate easily. Furthermore, when applied to a hot roll fixing method, there is a strong tendency for dyes to stain the fixing roller.

For example, when pigments are used as colorants, they are generally superior to dyes in terms of heat resistance and light resistance, and toner aggregation does not tend to occur even when stored at high temperatures.

However, many pigments have problems in dispersibility in binder resins. In other words, this is not a major problem when using a binder resin made of a polymer with a relatively low molecular weight, but pigment dispersion may be difficult when using a binder resin with a relatively high molecular weight or a crosslinked type. The problem arises that not enough is being done.

As a result, the following characteristic disadvantages occur.

In other words, many pigments have poor coloring power to toner,
Therefore, it is necessary to add a large amount of pigment, which deteriorates fixing properties. In addition, variations in pigment distribution within toner particles occur (that is, in extreme cases, toner particles that contain a large number of pigment particles and toner particles that do not contain any pigment particles at all), so the toner itself The charging property of the product becomes unstable, resulting in a decrease in image density due to repeated use over a long period of time, or due to environmental changes (temperature/humidity fluctuations), etc.
Harmful effects such as an increase in soil-bearing yellowtail may occur. Furthermore, since there are naked pigment particles that are not incorporated into the toner particles, these may contaminate the surface of the photoreceptor or toner carriers such as sleeves and carriers, resulting in filming, image blurring, poor cleaning, soil blemish, etc. For example, it may cause undesirable phenomena such as a decrease in image density.

As described above, the current situation is that even if dyes and pigments are incorporated into toners as they are, only toners with some drawbacks can be obtained.

[Problems to be Solved by the Invention] The purpose of the present invention is to ensure that fine particles are sufficiently dispersed in a binder resin, thereby preventing contamination on the surface of the photoconductor or toner carrier, as well as poor cleaning in the toner cleaning process. The purpose of the present invention is to provide a toner with excellent electrophotographic properties. Another object of the present invention is to provide a toner that faithfully develops, transfers, and fixes the latent image, that is, there is no fogging phenomenon, toner scattering around the latent image, poor fixing, offset, etc., and the image density is high. The purpose of the present invention is to provide a toner with excellent reproducibility in halftone areas. Another object of the present invention is to provide a toner that maintains its initial good characteristics even after long-term use and environmental changes. Furthermore, another object of the present invention is to provide a method in which the amount of triboelectric charge of the toner is stable and that the amount of triboelectricity of the toner is stable and that the toner on the toner carrier in the case of one-component development is triboelectrically charged between toner particles or on a toner carrier in the case of one-component development. The object of the present invention is to provide a developer that has a uniform amount distribution and can be controlled to have a charge amount suitable for the developing system used. However, all frictional means herein include frictional charging by a toner carrier, that is, a developing sleeve, or frictional charging by other friction members.

[Means and effects for solving the problems] According to the present invention, there is provided a toner comprising at least a binder resin and fine particles, the fine particles containing a nonionic surfactant. Ru.

Examples of nonionic surfactants used in the present invention include polyoxyethylene ethers of various fatty acids, polyoxyethylene ethers of higher alcohols, alkylphenol polyoxyethylene ethers, polyoxyethylene ethers of sorbitan esters, and polyoxypropylene. Examples include polyoxyethylene ethers of , polyoxyalkylene ethers of castor oil, and alkylolamides of various fatty acids.

The nonionic surfactants used in the present invention include cationic nonionic surfactants containing, for example, amines that dissolve in acidic solutions, and anionic nonionic surfactants containing carboxyl groups that dissolve in basic solutions. Included and preferred.

The content of these nonionic surfactants in the fine particles varies depending on the shape, size, etc. of the fine particles, but in the present invention, it is 0.005 to 30% by weight, preferably o,
The range of oi to 10% by weight, particularly 0.05 to 2% by weight, was good. If the nonionic surfactant content is too low, it is difficult to ensure the stability and uniformity of the triboelectric charge, and if it is too high, it tends to absorb moisture, especially during long-term storage or use. There is a tendency to cause a decrease in physical properties.

In the present invention, other ionic surfactants can also be used in combination. However, anionic surfactants and cationic surfactants should be used in consideration of the fact that they are more hygroscopic than nonionic surfactants and are easily decomposed by acids and alkalis.

Further, the HLB value of the nonionic surfactant used in the present invention is preferably 5 or more, particularly preferably 8 to 20.

Further, those having a structure containing nitrogen are particularly preferred.

The fine particles used in the present invention have a BET specific surface area of 0.1 m2/g to 300 m2/g, preferably 1.0! I+2/g-150m2/g is preferable, and conventionally known fine particles, such as various organic pigments such as anthraquinone, quinacridone, phthalocyanine, perylene, perinone, and azo, or titanium oxide, iron oxide, and yellow lead. Various inorganic pigments such as , ultramarine, and navy blue, various metal oxides, metal chlorides, mixtures thereof, and metal compounds such as metal complexes can be used. Among these, it is particularly preferable to use it for azo pigments and phthalocyanine pigments. The amount of these fine particles added varies depending on the properties and purpose of each compound, but is preferably 0.2 to 80% by weight, preferably 0.5 to 70% by weight, and particularly 1 to 50% by weight.

The method for incorporating the nonionic surfactant into the fine particles of the present invention is to add the fine particles to a solution containing the nonionic surfactant, heat and stir, and then filter and dry. Alternatively, if the fine particles are organic pigments, they are added as an aqueous solution during pigment synthesis.

Alternatively, a method of spray drying a mixed solution of fine particles and a nonionic surfactant may be used, but in the present invention, a method of adding the surfactant at the time of synthesis showed preferable results. Here, the time of synthesis includes tinging before and after synthesis.

Further, the toner of the present invention may be used in combination with any coloring agent, if necessary.

Binder resins used in the present invention include monopolymers of styrene and its substituted products such as poly p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, and styrene-p-chlorostyrene copolymers; Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, Styrene-methyl methacrylate copolymer, styrene-
Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Coalescence, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-malein M copolymer ff
Styrenic copolymers such as styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate-I, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy Resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin,
Paraffin wax and the like can be used alone or in combination.

The effect of the present invention is that the melt flora index value is 0.1.
~20g/10 minutes (test conditions: load 10kg.

A great effect was shown when using a binder resin at a temperature of about 125°C. The melt flow index used here is based on the Japanese Industrial Standards JIS flow test method for thermoplastic plastics.
K? The measurements were carried out using the apparatus described in No. 210 by a manual cutting method.

The binder for which the present invention is particularly effective has a weight average molecular weight (
These are vinyl polymers, polyesters, and epoxy resins synthesized from vinyl monomers having a ratio (Mw/Mn) of Mw) to number average molecular weight (Mn) of 4 or more, particularly 10 or more.

Here, the above value of M w /M n was calculated from the value measured by gel parenchyma chromatography. The measurement conditions were as follows: Tetrahydrofuran was used as a solvent at a flow rate of 1 ml per minute at a temperature of 25°C, and the sample concentration was 8.
0.5 mg/m tetrahydrofuran sample solution
+I1M injection and measurement. In addition, as a column, 1
In order to accurately measure the molecular weight range of 03 to 2 x 106, it is recommended to combine several commercially available polystyrene gel columns.
Agel 500.103.104.105 combination and Showa Denko (7) shodex A-802, 803
, 804°805 is a good combination. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithm value and the count number of a calibration curve prepared using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for creating a calibration curve, for example, Pressur
e Chemical Co., or Toyo Tsudani Gyo Co., Ltd. with a molecular weight of 6 x 102, 2. I X103, 4
X103, 1.75X104.

5, IX to4. 1.1 x to5.3.9
X to5゜8.8 X 105.2 X 106.4
．． It is appropriate to use a 48×106 polystyrene sample and at least 10 standard polystyrene samples. Further, an RI (refractive index) detector is used as a detector.

Furthermore, in order to use the toner as a magnetic toner, magnetic powder may be included. Such magnetic powders are materials that are magnetized when placed in a magnetic field, such as powders of ferromagnetic metals such as iron, cobalt, and nickel, or alloys and compounds such as magnetite, γ-iron oxide, and ferrite. be. The content of this magnetic powder is 10 to 10% based on the weight of the toner.
70% by weight is preferred.

The above toner composition is used as a microcapsule toner.
It is also possible to carry it on the wall material, the core material, or both.

The toner of the present invention may be mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite powder, etc., if necessary, and used as a developer for electrical latent images. The developer of the present invention can be applied to various development methods. For example, magnetic brush development method, cascade development method, US Pat.
[Method using conductive magnetic toner described in JP-A No. 9,258, method using high-resistance magnetic toner described in JP-A-53-31138, JP-A-54-421
Publication No. 41, Publication No. 55-1885E1, Publication No. 54-4
Examples include the method described in Japanese Patent No. 3027, a fur brush development method, a powder cloud method, an impression development method, and the like. Among these, the method of developing using the triboelectric charge of toner is particularly suitable for the present invention.

Further, when the developer is held in a developer carrier such as a sleeve, it is possible to use magnetic force, Coulomb force, electrostatic force, image force, mechanical force, etc. Further, as the transfer method used in the present invention, conventionally known methods such as an electrostatic transfer method, a bias roll method, a pressure transfer method, and a magnetic transfer method are used. Further, as a method for cleaning the remaining toner on the photoreceptor, conventionally well-known blade cleaning methods, fur brush cleaning methods, magnetic brush cleaning methods, etc. are used, but the blade cleaning method is particularly suitable for the toner of the invention. There is. Further, immediately before the cleaning process, a static elimination process or the like may be provided as necessary to facilitate toner cleaning.

The effects of the present invention regarding cleaning properties are particularly evident in OPC.
Photoreceptor (organic photoconductor) Favorable results were shown for an amorphous silicon photoreceptor.

[Example 1] Hereinafter, the present invention will be explained in detail using Examples, but the present Examples are not intended to limit the present invention in any way. Note that all parts in the examples are parts by weight.

Example 1 (a) 195i of water was added to 5 parts of polyoxyethylene nonylphenol (HLB value 13) as a nonionic surfactant, heated to 80°C, and then a commercially available copper-phthalocyanine pigment (G, 1. Pigment blue 15) was added.
20 parts were added and stirred for 40 minutes.

After stirring, the suspension was filtered and dried to obtain a copper-phthalocyanine pigment containing approximately 0.15% by weight of polyoxyethylene nonylphenol.

(b) Toner treatment: Copper-phthalocyanine pigment obtained in (a) 8 parts styrene-
Diethylaminoethyl methacrylate copolymer 60 parts Styrene-butadiene resin 40 parts Polypropylene resin 8 parts (M% of the above binder
t/Mn was 9B. ) in a roll mill at 150℃1
After heating and kneading for 5 minutes, the mixture was cooled, coarsely crushed in a hammer mill, and then finely pulverized in an air jet type pulverizer. Further, air classification was performed to select 5 to 25 JL, and 1% by weight of colloidal silica was added to prepare a toner. When the obtained toner was observed under a microscope, it was found that the toner particles contained pigment in uniform particles, and no transparent toner particles containing no pigment or pigment aggregates were observed.

Next, when copies were made using the toner using a PC-20 copying machine (cannon acid: PC-20 is a copying machine that uses an OPC photoreceptor and employs a blade cleaning method), clear and fog-free copies were obtained. A blue image was obtained.

The maximum image density (hereinafter abbreviated as D wax) at this time is 1.
It was 20. Further, even after 4,000 continuous copies were made in an environment of 15° C. and 10% humidity, clear images were obtained without any poor cleaning, filming, or image deletion.

Further, the D wax at this time was 1.17, which was almost the same value as the initial image.

Comparative Example 1 The copper-phthalocyanine pigment used in Example 1 was used as it was. A toner obtained in the same manner as in Example t (b) except for superposition was observed under a microscope, and it was found that the pigment dispersion in the toner particles was extremely poor. , transparent toner particles not containing pigment, toner particles containing pigment, and pigment aggregates were mixed. Furthermore, when copying was carried out in the same manner as in Example 1, only an image with some noticeable fogging was obtained, and the D wax was as low as 1.01. Furthermore, in an environment of 15℃ and 10% humidity, 4
After copying 000 sheets, the fog further increases and Dmax becomes 0.
．． 41, and a filming phenomenon was observed on the surface of the photoreceptor.

Example 2 (a) 20 weight percent N of acetoacetoxylidide
A solution prepared by dissolving 5 parts of polyoxyethylene stearate (HLB value 16) and 5 parts of triethanolamine oleate (HLB value 12) as nonionic surfactants in 80 parts of water was gradually added to 100 parts of aOH aqueous solution, and further hydrochloric acid was added. Aqueous solution was added.

Next, 100 parts of a 10% solution of 2.2',5.5'-tetrachlorobenzidine diazotized using hydrochloric acid and sodium nitrite was added to form a yellow pigment containing polyoxyethylene stearate and triethanolamine oleate. I got it.

(b) 10 parts of the yellow pigment obtained in (a) of the toner powder 100 parts of a polyester resin (My/Mn is 25) 100 parts of a 3.5-di-tert-butylsalicylic acid chromium complex 4 parts and 10 parts of Example 1 A toner was obtained in the same manner as in (b). A developer was prepared by adding 85 parts of an iron carrier (DSP 357 carrier manufactured by Dowa Iron Powder) to 15 parts of this toner. When copies were made using this developer using a Canon MP-COLOR copying machine, high-resolution images without fog and toner scattering were obtained. Furthermore, even after 20,000 continuous copies were made, clear images without fog were obtained, there was no contamination on the surface of the photoreceptor, and no defective cleaning occurred.

Example 3 (a) To 10 parts of tallow fatty acid monoethanolamide ethoxylate (HLB value 12) as a nonionic surfactant, 150 parts of water and 40 parts of isopropanol were added, heated to 80°C, and then commercially available γ-iron oxide 50 parts were added and stirred for 60 minutes. After stirring, the mixture was filtered and dried to obtain γ-iron oxide containing approximately 1.1% by weight of beef tallow fatty acid monoethanolamide ethoxylate.

(b) 70 parts of γ-iron oxide obtained in (a) from Toner Muho Example 2
Yellow pigment obtained in (a) 5 parts Styrene-butyl acrylate copolymer 90 parts Styrene-butadiene copolymer 10 parts Nigrosine dye 1 part (My
/Mn was 55. ) Example t (b)
A toner was obtained in the same manner. Then, using the toner,
NP-1502 copier (Canon: NP-1502)
is a copying machine that uses an OPC photoreceptor and employs a blade cleaning method. ), a clear sepia-colored image with no fog was obtained. 20,000 copies were made in an environment of 15° C. and 10% humidity, but no image deletion, poor cleaning, filming, etc. occurred.

Example 4 (a) As a nonionic surfactant, 1 part of water was added to 5 parts of polyoxyethylene rubitan monopalmitate (HLB value 15).
After adding 35 parts and 60 parts of ethanol and heating to 30°C,
50 parts of black iron oxide was added and stirred for 15 minutes. After stirring, the mixture was filtered and dried to obtain black iron oxide containing about 0.08% by weight of polyoxyethylene rubitan monopalmitate.

(b) Toner A toner was obtained in the same manner as in Example t (b) except that the black iron oxide obtained in (a) was changed to 70 parts and the salicylic acid chromium complex was changed to 1 part. Using this toner, an experimental machine modified for use with an amorphous silicon photoreceptor was used to create a dark area +50
0V, bright area +100V photoreceptor surface and developing sleeve 3
00#1.111, and a frequency of 1800 Hz and a peak-to-peak value of 1.4K was set between this developing sleeve and the photoreceptor surface.
Development, transfer, and blade cleaning corresponding to 250,000 continuous sheets were performed by applying a voltage of V center value +250 V and a transfer voltage of +8 KV, but no filming or cleaning failure occurred.

Example 5 (a) As a nonionic surfactant, 175 parts of water was added to 10 parts of diethylene glycol monolaurate (HLB value 6) and 15 parts of triethanolamine oleate (HLB value 12) and heated to 80°C. Silicon oxide fine powder 1
0 part was added and stirred for 12 hours. After stirring, the suspension was centrifuged and further dried to obtain silicon oxide containing approximately 10 weight percent of diethylene glycol monolaurate and triethanolamine oleate.

(b) Toner treatment 5 parts of silicon oxide obtained in (a) Example 1 (a)
) Copper phthalocyanine pigment obtained in Example 2 (a) 2 parts Yellow pigment obtained in Example 2 (a) 5 parts Styrene-diethylaminoethyl methacrylate resin 80 parts Styrene-butadiene resin 10 parts (Mw/Mn of the above binder was 85) A toner was obtained in the same manner as in Example t(b) except for the overlapping. Then, when the toner was used for copying in the same manner as in Example 1, a clear green image without fogging was obtained.

[Effects of the Invention] As described above, in the present invention, since the fine particles that are the constituent components of the toner contain a nonionic surfactant, the toner can be triboelectrified when used in a triboelectrification type device. The amount is stable, and the distribution of the amount of triboelectric charge is uniform, so that the amount of charge can be controlled to be suitable for the developing system used. Furthermore, based on the above toner structure and the stability and uniformity of the amount of triboelectric charge, the toner of the present invention does not cause contamination on the surface of the photoconductor or toner carrier, has excellent electrophotographic properties, and has excellent electrophotographic properties. It enables faithful development, transfer, and fixing, eliminates fogging, toner scattering around the latent image, poor fixing, offset, etc., provides high image density, and has excellent reproducibility in halftone areas, allowing for long-term use. Initial good characteristics can be maintained even under environmental changes.

Claims (1)

[Claims] A toner comprising at least a binder resin and fine particles, the fine particles containing a nonionic surfactant.