JPH04156551A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To improve the dispersibility of fine grains and the fluidity of a toner and obtain good picture quality over a long period by using toner powder and resin fine grains having an average grain size smaller than the average grain size of the toner powder and surface-treated with amino denatured silicone oil. CONSTITUTION:A powder toner is dispersed with an additive such as a colorant and a charge control agent in binding resin. The average grain size of the toner powder on the volume standard by a coal counter is preferably set to 5-30mum, more preferably 5-15mum in particular. Resin fine grains have an average grain size smaller than the average grain size of the toner powder. Acrylic resin or acryl urethane resin is used for the resin constituting the resin fine grains. The average grain size of the resin fine grains is preferably set to 0.05-5mum, more preferably to 0.1-4mum. The resin fine grains are treated with amino denatured silicone oil. The treatment quantity of the amino denatured silicone oil is preferably set to 0.01-5wt.% against the resin fine grains, more preferably to 0.05-2wt.%.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a toner for developing an electrostatic image that is used in an image forming apparatus such as an electrophotographic copying machine, and more specifically to a toner for developing an electrostatic image that has excellent fluidity. Regarding developing toner.

(Prior Art) In an image forming apparatus such as an electrophotographic copying machine, a binder resin and a coloring agent are generally added as a developer for visualizing an electrostatic latent image formed on a photoreceptor using a dry development method. A two-component developer is used, which includes a toner and a carrier.

Such a two-component developer is used after being uniformly mixed by stirring. By stirring, the toner is charged by friction with the carrier and adheres to the surface of the toner. The electrostatic latent image formed on the photoreceptor through the charging and exposure steps is developed with this toner. The obtained toner image is transferred to a support such as transfer paper, and then fixed onto the support by a fixing means. In this way, a copy of the original is obtained.

In such a magnetic brush development method using a two-component developer containing a toner and a carrier, the toner needs to have good fluidity in order to perform development well.

By the way, as a toner that prevents a decrease in image density and an increase in fog, JP-A-60-186854 discloses a toner powder and a fine powder (soap-free) having an average particle diameter smaller than the average particle diameter of the toner powder. A toner for developing an electrostatic image containing a toner (obtained by a polymerization method) has been proposed.

(Problems to be Solved by the Invention) The above-mentioned toner has the disadvantage that the fine powder has poor dispersibility and is prone to agglomeration, and furthermore, the resulting toner has poor fluidity, resulting in poor image quality as copying is performed. It had the disadvantage of causing a decline.

In particular, in the case of positively chargeable toner containing a positive charge control agent, the charge control agent often has hydrophilic properties, which further reduces the fluidity of the toner, making it impossible to obtain good image quality. Furthermore, when Nigron dye is used as a charge control agent, it has the drawback of being easily altered and lacking in stability.

The present invention solves the above-mentioned drawbacks, and its purpose is to improve the dispersibility of fine particles and the fluidity of toner, thereby making it possible to form good image quality over a long period of time. An object of the present invention is to provide a toner for developing electrostatic images. Another object of the present invention is to provide a positively chargeable toner with excellent stability.

(Means for Solving the Problems) The toner for developing an electrostatic image of the present invention contains toner powder and fine resin particles having an average particle size smaller than the average particle size of the toner powder. is treated with amino-modified silicone oil, thereby achieving superior S-pyrolysis.

(Function) Since the resin particles used in the toner for developing electrostatic images of the present invention are surface-treated with the above-mentioned amino-modified silicone oil, the fluidity of the resin particles is improved, and as a result, the resin particles are uniform with the toner powder. It will be dispersed into l
・Improves the fluidity of the gel. In addition, the resin particles surface-treated with amino-modified/licon oil have strong positive chargeability and high humidity stability. Therefore, the toner has good positive chargeability even when used under high humidity. is obtained.

(Preferred embodiment of the invention) As the powder toner used in the present invention, a known toner conventionally used in a dry development method is used, and additives such as a colorant and a charge control agent are dispersed in a binder resin. It is a powdered toner. Such toner powder can be produced by a conventionally known method, such as a pulverization method in which each toner material is melt-kneaded, then pulverized and classified, or It can be obtained by a legal method (for example, suspension polymerization method, dispersion polymerization method, etc.).

The binder resin used in the toner powder is, for example, a thermosetting resin or a thermosetting resin in an uncured form or in the form of an initial condensate, and has a melting point or softening point in the range of 60 to 200°C. is used. Suitable examples include, but are not limited to, polystyrene, acrylic polymers,
Styrene-based copolymers, chlorinated polyethylene, polypropylene, olefinic polymers such as ionomers, polyvinyl chloride, polyester, polyamide,
Polyurethane, epoxy resin, diallyl phthalate resin, silicone resin, ketone resin, polyvinyl acetal resin such as polyvinyl butyral resin, phenol resin,
Examples include various polymers such as rosin-modified phenolic resin, rosin-modified maleic resin, rosin-modified maleic acid resin, rosin ester, and petroleum resin. These resins are arbitrarily selected depending on the fixing method and other required properties. Among these, because it is easy to control the crushability and molecular weight distribution,
Polystyrene, acrylic polymers or styrene-acrylic polymers are preferred, and styrene-acrylic polymers are particularly preferred. These resins have a weight average molecular weight of 30.0
00 to 200.000, especially 50.000
．． A range of 000 to 150.000 is preferred. One type of polymer or a mixture of two or more types may be used.

When the toner powder used is a pressure fixing toner,
It is preferable to contain an olefin polymer such as polyethylene or polypropylene, or a polymer that is easily plastically deformed such as polyamide. This polymer may contain other polymers such as polyvinyl acetate, ethylene-vinyl acetate copolymer, hydrogenated polyethylene, hydrogen rosin ester, aliphatic, ring group or aromatic petroleum resin, etc. You can.

Examples of the charge control agent include oil-soluble dyes such as nigrosine dye, oil black, and spirone black;
Metal soaps, which are metal salts of naphthenic acid, salicylic acid, octylic acid, fatty acids, resin acids such as manganese, iron, cobalt, nickel, lead, zinc, cerium, calcium, etc., metal-containing azo dyes, pyrimidine compounds, alcohol Examples include salicylic acid metal chelate, binder resin 100
0.1 to 5 parts by weight per part by weight is preferably used.

As the pigment, in addition to coloring pigments, any of various pigments conventionally used in toners, such as magnetic pigments and conductive pigments, can be used. Suitable examples include, but are not limited to:

black pigment Channel black, furnace black, iron black.

Yellow pigment yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel yellow, nickel titanium yellow, fiss yellow, teftol yellow 31 Hansaie O-10G.

Benzidine Yellow G, Ushi Norin Yellow, Permanent Yellow NGG, Tartrazine Lake.

Orange pigment red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan ore, indanthrene brilliant orange RK, benzidine orange G1 indanthrene brilliant orange G
K.

Red pigment red pigment Red Garla, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Orange 4R, Lysole Red, Pyrazolone Red, Wosochinda Red Power Runum Salt, Lake Red D1, Brilliant Carmine 6B, Eosin Lake, Rotamin Lake B1, Alizarin Lake, Brilliant Cardan 3B0 Purple Hegemony Manganese Purple, Fast Vilet B1 Methyl Violenotray Cow.

Blue pigments navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated product, first sky blue, indanthremble-BC
.

Green pigment chrome green, chromium oxide, pigment green B,
Malachite Green Lake, Final Yellow Green G0 White pigment titanium dioxide (titanium white), zinc white.

Extender pigments barachite powder, barium carbonate, clay, silica, white carbon, talc, aluminum white.

Examples of magnetic material pigments include triiron tetroxide, iron sesquioxide, zinc iron oxide, yttrium iron oxide, cadmium oxide, iron and steel oxide, iron oxide complex, neodymium iron oxide, barium iron oxide, iron manganese oxide, and lanthanum iron oxide. , iron powder, cobalt powder, nickel powder, etc., and any of these known fine powders of magnetic materials can be used in the present invention.

These pigments may have multiple functions. For example, carbon black has the functions of a black pigment and a conductive pigment. Similarly, iron black (magnetite) has the functions of a black pigment and a magnetic pigment.

These colorants are used alone or in a mixture of two or more, and the amount to obtain a sufficient toner image density is, for example, 5 to 15% by weight, particularly 7 to 12% by weight. It is better.

Further, the toner powder may contain an anti-offset agent to prevent the toner powder from adhering to the fixing roller. For example, various animal and plant waxes, volutelene wax, polypropylene wax, etc. are used as offset inhibitors, and these are generally added to the toner powder at a concentration of 1%.
It is blended in an amount of ~5% by weight.

The method for manufacturing toner powder in the present invention is similar to the conventional toner manufacturing process, so it will not be described in detail. The particle size of the obtained toner powder is preferably 5 to 30 μm, particularly 5 to 1
5 μm is preferred.

The resin fine particles used in the present invention are resin fine particles having a smaller average particle size than the average particle size of the toner powder described above. Examples of the resin constituting the resin fine particles include acrylic resin, acrylic-urethane resin, and the like. The average particle diameter of the resin fine particles is preferably 0.05 to 5 μm, more preferably 01 to 4 μm. In particular, dispersion polymerization,
Acrylic fine particles with an average particle size of 01 to 4 μm obtained by emulsion polymerization, soap-free polymerization, and pulverization are preferred.

These resin particles are treated with amino-modified silicone oil. As the amino-modified silicone oil, for example, those whose general formulas are represented by the following formulas (A) and (B) are used.

R: CI-b4f~ is QC)h Examples of commercially available amino-modified silicone oils include the following.

■Made by Shinetsu Henricorn■...KF393, KF857,
KF858, KF859, KF860, KF861, K
F862, KF864, KFll165, X-22-3
680, X-22-380D, X-22-3801C
SKF867゜■Made of Toray silicone■, 5F841
7, BY 16-828, BY 1.6-849, B
Yl6-850, BYl6-859, BYl6-872
, BYl6-853, BYl, 6-8538゜■Made by Toshiba silicone, TSF4452, TSF470
0. At least one type of the TSF4701 and TSF4702 amino-modified silicone oils is selected from these groups.

The amount of these amino-modified silicone oils to be treated is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight based on the resin fine particles. If the processing amount of amino-modified silicone oil is less than 1% by weight, the effect of improving the fluidity of resin particles, the effect of improving the dispersibility of resin particles and the fluidity of toner will be reduced, and if it is more than 5% by weight, On the contrary, the fluidity of the resin particles tends to decrease.

To process amino-modified silicone oil into fine particles,
It can be carried out using various conventionally known methods and devices, for example, by immersing the resin fine particles in amino-modified silicone oil or applying the oil to the resin fine particles,
Then dry it.

The toner of the present invention may also contain a fluidity modifier such as hydrophobic silica in an amount of 0.1 to 0.5% by weight based on the toner. The toner according to the invention is obtained by sprinkling the properties improver in a mixer and processing.

The toner of the present invention can be mixed with a magnetic carrier such as ferrite or iron powder as a two-component developer, or when the toner contains a magnetic pigment, can be used as a one-component developer to develop electrostatic latent images. used for.

(Effects of the Invention) According to the present invention, by treating the fine particles with amino-modified silicone oil, the fluidity of the fine particles can be improved, thereby improving the dispersibility and improving the fluidity of the toner. Therefore, it is possible to provide an electrostatic image developing toner that can form a good image with little variation in image quality and has excellent durability without deterioration in development characteristics such as a decrease in the amount of charge. Further, it is possible to provide a toner having good positive chargeability even when used under high humidity.

(Example) Hereinafter, the present invention will be explained based on examples.

Tip 1! mouth.

Styrene/n-butyl acrylate copolymer 100 parts by weight Carbon black (manufactured by Mitsubishi Kasei Co., Ltd., #44) 10 parts by weight Charge control agent (manufactured by Orient Chemical Co., Ltd., Bontron N-01
) 1 part by weight of polypropylene (manufactured by Mitsubishi Kasei Corporation, Viscoll 660P) 2 parts by weight After melt-kneading the mixture consisting of the above formulation, it was pulverized using a jet mill and classified to obtain an average particle size of 11.0 μm.
I got Kakaku toner powder.

Meanwhile, methyl methacrylate 500 was placed in a four-bottle flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube.
parts by weight, 0.3 parts by weight of potassium persulfate, and 0.3 parts by weight of polyvinyl alcohol, and heated at 80°C in a nitrogen stream for 4 hours.
A time reaction was performed. After the polymerization was completed, centrifugation, water washing, and drying were performed to obtain acrylic fine particles with an average particle size of 0.2 μm.

100 parts by weight of the acrylic fine particles and 1 part by weight of amino-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF393) were stirred using a high-speed stirring device, and then dried at 80° C. for 1 hour to obtain a treated fine powder.

100 parts by weight of the above toner powder, 0.3 parts by weight of treated fine powder, and hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., R972)
A toner was obtained by mixing and stirring 0.2 fi parts using a Henschel mixer.

A developer was prepared by mixing 4 parts by weight of this toner and 96 parts by weight of a ferrite carrier having an average particle size of 80 μm, and this developer was loaded into a DC-2055 modified machine manufactured by Sanda Kogyo ■ (temperature: 35°C). 5 in an environment of C1 humidity 80%)
We created 10,000 images. The results are shown in Table 1.

K Sarasho Niamino modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF39
3) A toner was obtained in the same manner as in Example 1, except that 1 part by weight of amino-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF873) was used instead of 1 part by weight.

The obtained toner was evaluated in the same manner as in Example 1. The results are also shown in Table 1.

A toner was obtained in the same manner as in Example 1 except that the treated fine powder was not used. The obtained toner was evaluated in the same manner as in Example 1. The results are also shown in Table 1.

A toner was obtained in the same manner as in Example 1, except that the untreated acrylic fine particles obtained in Example 1 were used instead of the Δhill main-treated fine powder. The obtained toner was evaluated in the same manner as in Example 1. The results are also shown in Table 1.

ΔTakumi amino-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF39
3) A toner was obtained in the same manner as in Example 1, except that 1 part by weight of silicone oil [manufactured by Shin-Etsu Chemical Co., Ltd., KF-9650cs (this is dimethyl silicone oil] was used instead of 1 part by weight). The obtained toner was evaluated in the same manner as in Example 1.

The results are also shown in Table 1.

(Left below) From the results in Table 1, it can be seen that when no treated fine powder is used (Comparative Example 1)
), the image density (1, D, ) and fog density (F, D,) increased after printing 50,000 sheets, and even when untreated fine resin powder was used (Comparative Example 2), the printing durability increased. After fog density (
F, D,) are increasing.

Furthermore, even when resin fine particles that are not amino-modified/treated with silicone oil are used, their properties are insufficient. On the other hand, in this example, it was confirmed that the image density and image characteristics were all satisfactory.

that's all

Claims (1)

[Scope of Claims] 1. A toner for developing an electrostatic image, comprising a toner powder and fine resin particles having an average particle size smaller than the average particle size of the toner powder, the fine resin particles comprising: A toner for developing electrostatic images that is treated with amino-modified silicone oil.