JPS58125045A - Electrostatic image developing toner - Google Patents

Abstract

PURPOSE:To obtain a toner superior in fluidity and not damaging a photoreceptor surface, by mixing a toner powder contg. a colorant dispersed into a resin, a hydrophobic fine silica powder, and a metallic salt of aliphatic acid with a binder contg. an offset inhibitor in a specified proportion range. CONSTITUTION:A developing toner contg. an offset preventing agent having 80- 180 deg.C m.p., such as polyethylene or polypropylene, and a colorant, such as carbon black or nigrosine dispersed into a styrene type binder (both in the case of one or two component type toner) is mixed with 0.1-10wt% hydrophobic fine silica powder (weight proportion X), and 0.1-10wt% zinc stearate or zinc or magnesium maleate, or the like aliphatic acid salt (weight proportion Y) based on the weight of the toner so as to give 0.25<Y<X<=1. As a result, it can be heat fixed especially at high speed and low pressure, and it has good fluidity and good fixability, and long time stability, and it can form a high density image.

Description

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

Generally, an electrostatic charge image is developed into a visible image, and the most widely used method for developing this electrostatic charge image is a dry development method that uses toner powder containing a coloring agent, etc. in binder resin particles. It is used.

10 on the other hand! The toner image that is developed and formed by toner particles adhering to the image support according to its electrostatic charge is transferred to transfer paper, etc. in order to use the electrostatic image support repeatedly (3). Needs to be anchored above. Various methods are known for this fixing method, but a contact heat fixing method using a heating roller is particularly superior in that it has higher thermal efficiency than a non-contact heat fixing method using a hot plate fixing device. This is particularly preferable since high-speed fixing is possible.

Although the contact heat fixing method is preferable in various respects as described above, this method has a problem in that an offset phenomenon occurs. This is a phenomenon in which a portion of the toner constituting the toner image is transferred to the surface of the heating roller during fixing, and this is transferred again to the transfer paper or the like that is sent next, staining the image.

Various proposals have been made in the past to prevent this offset phenomenon, but it is desirable that the toner particles themselves have offset prevention performance.

In order to impart offset prevention performance to the thorn particles,
It is effective to include an anti-offset agent in the binder resin together with a colorant and others. However, toner particle powder containing an offset inhibitor has lower fluidity and increased cohesiveness, resulting in poor development properties and a tendency to be unable to form a visible image with sufficiently high image density. occurs.

On the other hand, it is effective to mix hydrophobic silica fine powder in order to improve the fluidity of toner powder, but it is necessary to mix hydrophobic silica fine powder in an amount that will give sufficient fluidity to the toner powder containing the anti-offset agent. When fine silica powder is mixed, the surface of an electrostatic image support such as an electrophotographic photoreceptor may be scratched.
As a result, a good visible image cannot be obtained.

As described above, toners for developing electrostatic images are required to have various properties in order to obtain good visible images, and conventionally, there have been no means to impart or improve specific properties. Even though it is known, the conditions for imparting various properties simultaneously effectively and without any adverse effects are unknown, and in the end, some properties are sacrificed, resulting in a fully satisfactory visual result. ``The formation of an image is not necessarily realized.

The present invention has been made based on the above-mentioned circumstances (5), and is capable of achieving sufficient fixing by a contact heating fixing method, without causing an offset phenomenon, and damaging the surface condition of an electrostatic image support. An object of the present invention is to provide a toner for developing an electrostatic image that can stably form a good visible image over a long period of time without causing any damage.

The above object is to provide a toner powder in which a colorant is dispersed in binder resin particles containing an anti-offset agent;
0.1 to 0.1 of the toner powder mixed with this toner powder
10 weight of hydrophobic silica fine powder and 0.1 to 10 weight of fatty acid metal salt of the toner powder added to the toner powder, the hydrophobic silica fine powder and fatty acid metal for the toner powder. This is achieved by an electrostatic image developing toner that satisfies the formula %, where the weight proportions of the salt are X and y, respectively.

The present invention will be specifically explained below.

In the present invention, particles are formed by using a resin made of a styrene polymer, an acrylic (6) polymer, or a styrene-acrylic polymer as a binder resin, containing an anti-offset agent therein, and dispersing a colorant. To obtain a toner powder consisting of
10% by weight of hydrophobic silica fine powder is added and mixed, and 0.1 to 10% by weight of fatty acid metal salt is added to the toner powder, and the hydrophobic silica fine powder is added to the toner powder. When the weight ratio is X and the weight ratio of the fatty acid metal salt is y, electrostatic image development is carried out so that the ratio y/x of X and y is greater than 0.25 and within the range of 1 or less. Toner for use.

In Toner 01 of the present invention, since the binder resin of the toner powder particles contains an anti-offset agent together with a colorant, toner images can be fixed by an advantageous contact heat fixing method without causing an offset phenomenon. In particular, if the binder resin is made of a styrene polymer, an acrylic polymer, or a styrene-acrylic polymer, the softening point of the toner particles can be kept low and the lowest fixing temperature at which the off-censor phenomenon occurs. (The temperature at which the offset phenomenon occurs when fusing is performed with the temperature tool - H) can be increased, and the possible fusing temperature range is widened at an appropriate height. The temperature conditions required for the heating roller are significantly relaxed. In this way, good fixing can be performed without an offset phenomenon.

Furthermore, in the toner of the present invention, since the hydrophobic silica fine powder is mixed with the above-mentioned toner powder at a ratio of 0.1 to 10% by weight, the toner particles contain an anti-offset agent. However, high fluidity is obtained and cohesiveness is reduced, and as a result, the desired charging state is reliably obtained due to the friction caused by stirring, and the feeding is performed smoothly, so that the electrostatic image support adheres according to the electrostatic charge. As a result, it is possible to form a good visible image that is clear and has a sufficiently high image density as a result of being reliably adhered to the desired location.

Furthermore, the toner of the present invention has a ratio of 0.1 to the toner powder.
Since the fatty acid metal salt of ~10% by weight is added, even if the hydrophobic silica fine powder is mixed, the surface of the electrostatic image support will not be damaged, and therefore the electrostatic image support will not be damaged. It can be used repeatedly over a long period of time, and it also prevents the generation of spent toner due to the fusion of toner to carrier particles and the occurrence of toner filming due to adhesion of toner to the surface of the electrostatic image support. Since this can be prevented, visible images can be stably formed over a long period of time.

In the above, when explaining the weight ratio X of the hydrophobic silica fine powder and the weight ratio y of the fatty acid metal salt to the toner powder, as will be understood from the explanation of Examples described below, X is less than 0.1% by weight. If the required fluidity cannot be obtained and X exceeds 10% by weight, y is less than 0.1% by weight, or the value of y/x is 0.25 or less, electrostatic image support The surface of the body becomes damaged.

The value of y/x is preferably greater than 0.45. In addition, if y exceeds 10% by weight or y/
If the value of x exceeds 1, the visible image formed will have a large variation in image quality.

However, in the toner of the present invention, all of the above-mentioned functions and effects can be effectively obtained without being inhibited. A visible image can be stably formed over a long period of time.

The toner powder in the toner of the present invention has a semi-average particle size of 5 to 30
As mentioned above, it is preferable to use a styrene polymer, an acrylic polymer, or a styrene-acrylic polymer as the inner resin.

Monomers that provide such polymers include, for example, styrene, 0-methylstyrene, m-methylstyrene, p-
Methylstyrene, a-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butyA styrene, p-dotecylstyrene, p-methoxystyrene, p-7enylstyrene, p-chlorostyrene , methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexy(10) acrylate, lauryl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, 2-
Examples include ethylhexyl methacrylate, lauryl methacrylate, sugearyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, and dimethylaminoethyl methacrylate. These single substances can be used alone or in combination of several types to form a polymer.

The binder resin in the present invention contains a main component resin consisting of a polymer selected from the above-mentioned styrene, acrylic, and styrene-acrylic polymers. Other resins used as toner binders may be included for the purpose of improving properties such as stability of triboelectric charging properties and improvement of pulverizability. Examples of such resins include logi/modified (11) phenol-formalin resins, epoxy resins, polyurethane resins, cellulose resins, polyneedle resins, polyester resins, and styrene-butadiene resins. The amount of these resins added is within a range that does not impair the effects of the present invention, and is approximately 30% by weight or less based on the total weight of the resin.

When the toner of the present invention is a magnetic toner, a magnetic material is contained in the toner particles together with or in place of the colorant.

As a coloring agent, carbon black, nigrosine dye (
C,i, A30415B), aniline blue (C,1
, Ya 50405), Calco Oil Blue (C, I.

Aazoec Blue 3), Kurumi x o -
(C, I.

Al 4090), Ultramarine Blue (C, l.

A77103), Teyubon Oil Renot (C, I.

A 26105), Ginoline Yellow (C, 1, A4
70(15), styrene glue chloride <C, I45
2015), Phthalocyanine Blue (C, 1474)
160), malachite green okuza V-to (C, 1,
A42,000 person support rack (C, 1, A7726
Mention may be made of 6-pack Rose Bengal (C, 1, 45435), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image of sufficient density, and are usually contained in a proportion of about 11 to 20 parts by weight per 100 parts by weight of the binder.

The magnetic material may be a metal or alloy that exhibits ferromagnetism such as ferrite, magnetite, iron, cobalt, or nickel, or a compound containing these elements, or a material that does not contain a ferromagnetic element but is subjected to appropriate heat treatment. Mention may be made of alloys which become ferromagnetic, such as manganese-copper-aluminum, manganese-copper, alloys of the type called Heusler alloys containing manganese and copper, such as tin, or chromium dioxide, among others. These magnetic substances are uniformly dispersed in the binder in the form of fine powder with an average particle size of 0.1 to 1 micron. The content thereof is 11,720 to 70 parts by weight, preferably 40 to 70 parts by weight, per 100 parts by weight of toner.

The anti-offset agent used in the present invention is a polyolefin resin such as polypropylene, polyethylene, polybutene (13), and is compliant with JISK 2531.
-1960, preferably has a softening point of 80 to 180°C, especially one with a softening point of 1
It is preferable to use polypropylene having a temperature of 00 to 160°C.

Preferred examples of the hydrophobic fine powder to be added and mixed with the above toner powder include "Aerosil R972j r Silica D-17" manufactured by Nippon Aerosil Co., Ltd. and others.

Specific examples of fatty acid metal salts added to Nutoner powder include metal salts of maleic acid and zinc, magnesium, calcium, etc.; stearic acid and zinc, cadmium, barium, lead, iron, nickel, cobalt, copper, and aluminum. , metal salts with magnesium, etc.; dibasic lead stearate; oleic acid with zinc, magnesium, iron, cobalt,
Metal salts of copper, lead, calcium, etc.; metal salts of palmitic acid and aluminum, calcium, etc.; lead caprylate; lead caproate; metal salts of linoleic acid and zinc, cobalt, etc.; calcium ricinoleate; lysyl (14 ) Examples include metal salts of inic acid and zinc, cadmium, etc., and mixtures thereof. Among these, zinc stearate is particularly preferred.

The toner of the present invention can be used as either a -component toner or a two-component toner, and when used as a -component toner, it may contain a magnetic material as described above, or a two-component toner. When used as a developer, it is mixed with a carrier such as iron or glass beads to form a developer.

Carriers can generally be broadly classified into conductive carriers and insulating carriers, and the former is preferably oxidized or unoxidized iron powder, and the latter is iron,
A typical example is one in which the surface of carrier core particles made of a magnetic material such as nickel, cobalt, or ferrite is coated with an insulating resin.

As a developing method, when used as a -component toner, the bristle brush method, impression method, powder cloud method, etc. are used, and when used as a two-component toner, the so-called magnetic brush method, etc. Skating method etc. are used.

Examples of the present invention will be described below, but the present invention is not limited thereto. Note that "parts" represent parts by weight.

Example 1 50 parts of styrene, 20 parts of methyl methacrylate,
The number average molecular weight Mn obtained by copolymerizing with 30 parts of butyl methacrylate is 11.000, and the ratio of weight average molecular weight to number average molecular weight M w 7M n is 5.
100 parts of the copolymer resin of No. 4 was mixed with 5 parts of polypropylene "Viscol 660 pJ (manufactured by Sanyo Chemical Co., Ltd.) and 210 parts of carbon bran, and dispersed in a ball mill for about 24 hours, then kneaded with hot rolls, cooled, and pulverized. The powder was classified to obtain a toner powder with an average particle size of 14 microns.

To 100 parts of this toner powder, 1 part of hydrophobic silica fine powder [Aerosil R972J (Nippon Aerosil Co., Ltd. ff) and 06 parts of zinc stearate (manufactured by Nippon Oil & Fats Co., Ltd.) were added and thoroughly stirred. /x = 0.6) was produced.

98 parts of a carrier coated with a copolymer resin obtained by copolymerizing iron powder particles with a particle size of 50 to 80 microns with 70 parts of styrene and 30 parts of methyl methacrylate using a fluidized bed apparatus; The toner of the present invention was mixed with 2 parts of the toner of the present invention, and the resulting image material was applied once a month for 10,000 or more consecutive times in an electronic photocopying machine "Modified U-Bix VJ (manufactured by Konishiroku Photo Industry Co., Ltd.)". When a copy test was conducted over a period of time, all of the copied images formed were clear and good.

Example 2 A toner of the present invention (y/x=0.5) was produced in the same manner as in Example 1, except that t of the hydrophobic silica fine powder was 0.8 parts and zinc stearate was 0.4 parts. When a similar copying test was conducted using a developer obtained in the same manner, all of the copied images formed were clear and good.

Example 3 The toner of the present invention (0.47 parts in y/x) was prepared in exactly the same manner as in Example 1 (17) except that the amount of hydrophobic silica fine powder was 0.75 parts and the amount of stearin-depleted zinc was 0.035 parts. ) was produced, and a similar copying test was conducted using a developer obtained in the same manner. All of the copied images formed were clear and good.

Comparative Example 1 A comparative toner was produced in the same manner as in Example 1 except that hydrophobic silica fine powder and zinc stearate were not added, and a similar copying test was conducted using the developer obtained in the same manner. However, this comparative toner had low fluidity, and the copy images formed had extremely low image density.

Comparative Example 2 A comparative toner (y/x = 0.25) was produced in the same manner as in Example 1, except that the amount of hydrophobic silica fine powder was 1 part and the amount of zinc stearate was 0.25 parts. When a similar copying test was conducted using the developer thus obtained, the resulting copied image had vertical streaks that were recognized to be caused by scratches on the photoreceptor.

(18) Comparative Example 3 A comparative toner (y/x = 1.25) was produced in the same manner as in Example 1, except that the amount of hydrophobic silica fine powder was 0.8 parts and the amount of zinc stearate was 1 part. However, when a similar copying test was conducted using the developer obtained in the same manner, the resulting copied image was unclear and of low quality.

Comparative Example 4 A comparative toner was produced in the same manner as in Example 1, except that polypropylene "Viscol 6601) J was removed in the production of toner powder, and a similar copy test was carried out using the developer obtained in the same manner. As a result, stains that were recognized to be caused by toner stains on the fixing roller appeared in the copied images from the beginning of the test, and it was not possible to obtain good copied images.

Example 4 The toner of the present invention (y/x = 1.0 ) and (
19) When a similar copying test was conducted using the developer obtained in the same manner, all of the copied images formed were clear and good.

Example 5 A toner of the present invention (y/x -0,35) was produced in the same manner as in Example 1, except that the amount of hydrophobic silica fine powder was 1 part and the amount of zinc stearate was 0.35 parts. However, when a similar copying test was conducted using the developer obtained in the same manner, the resulting copied image had some vertical streaks that were recognized to be caused by scratches on the photoreceptor. However, the extent of the damage was small and tolerable, and the image was sufficiently valuable as a copy image.

(2) Procedural amendment (voluntary) February 28, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1 Indication of the case 1983 Patent application No. 6849 2. Title of the invention Toner for developing electrostatic images 3. Person making the amendment Relationship to the incident Patent applicant 7 Rigana 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo
Tokoro 5S 4Cke (127) Konishiroku Photo Industry Co., Ltd. Kinsha 5, date of amendment order 8, statement of contents of amendment, page 14, 3rd line from the bottom, ``Tokoro n tail brush method'' was changed to ``
The so-called magnetic brush method, bristle brush method” is corrected.

Claims (4)

[Claims] (1) A toner powder formed by dispersing a colorant in binder resin particles containing an off-cent prevention agent, and 0.1 to 10% of the toner powder mixed with this toner powder.
% by weight of hydrophobic silica fine powder and 0.1 to 10% by weight of fatty acid metal salt of the toner powder added to the toner powder, the hydrophobic silica fine powder and fatty acid metal salt for the toner powder. A toner for developing an electrostatic image, characterized in that the formula % is satisfied when the weight proportions of are respectively X and y. (2) The toner for developing electrostatic images according to claim 1, wherein the formula % is satisfied. (2) (3) The binder resin of the toner powder is selected from the group consisting of a styrene polymer, an acrylic polymer, and a styrene-acrylic polymer. Toner for developing electrostatic images. (4) Claim 1, wherein the content of the offset inhibitor is 1 to 20% by weight of the binder resin;
The toner for developing an electrostatic image according to item 2 or 3.