JPH04156552A - 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 treated with a specific finishing agent. CONSTITUTION:A powder toner is dispersed with an additive such as a colorant or 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 to 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 a finishing agent. At least one kind is selected among a silane coupling agent, a titanium coupling agent and an aluminum coupling agent for the finishing agent. The treatment quantity of the finishing agent is preferably set to 0.1-10wt.% against the resin fine grains, more preferably to 0.5-5wt.%.

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 image forming apparatuses such as electrophotographic copying machines, a binder resin and additives such as colorants are generally used as a developer to visualize an electrostatic latent image formed on a photoreceptor using a dry development method. A two-component developer containing a toner and a carrier is used. 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 carrier. 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 powder) having an average particle size smaller than the average particle size of the toner powder. A toner for developing an electrostatic image containing a toner (obtained by a free 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.

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.

(Means for Solving the Problems) The toner for developing an electrostatic image of the present invention contains a toner powder and fine resin particles having an average particle size smaller than the average particle size of the toner powder. The fine particles are treated with at least one type of surface treatment agent selected from the group consisting of a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent, thereby achieving the above object. Ru.

(Function) Since the resin particles used in the electrostatic image developing toner of the present invention are treated with the above-mentioned surface treatment agent, the fluidity of the resin particles is improved, and as a result, the resin particles are more uniformly dispersed than the toner powder. This improves the fluidity of the toner.

(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 thermoplastic 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-acrylic copolymers, chlorinated polyethylene,
Olefin polymers such as polypropylene and ionomers, polyvinyl chloride, polyester, polyamide, vol.
Urethane, Evokin resin, diallyl phthalate resin,
Polycone resin, ketone resin, polyvinyl butyral'
Examples include various polymers such as polyvinyl acecool resin such as M fat, phenol resin, rosin-modified phenol resin, xylene 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, polystyrene, acrylic polymers, or styrene-acrylic polymers are preferred, and styrene-acrylic polymers are particularly preferred, since they can easily control crushability and molecular weight distribution. These resins have a weight average molecular weight of 30.
000 to 200.000, especially 5
A range of 0.000 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, alicyclic or aromatic petroleum resins, etc. You may.

Examples of the charge control agent include oil-soluble dyes such as nigrosine dye, oil black, and subiron blasoku;
Metal soaps, which are metal salts of naphthenic acid, salicylic acid, octylic acid, fatty KR acid, resin acids such as manganese, iron, cobalt, nickel, lead, zinc, cerium, calcium, etc.
Alternatively, metal-containing azo dyes, pyrimidine compounds, alkyl salicylic acid metal chelates, etc. may be used.
It is preferably used in an amount of 0.1 to 5 parts by weight per 0 parts by weight.

As the pigment, in addition to colored pigments, 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 rack, furnace rack, iron black.

Yellow pigments yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel yellow, nickel titanium yellow, $-purus yellow, teftol yellow S1 Hansa yellow 10G.

Benzidine Yellow G, Quinoline 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 Gara, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Orange 4R, Resole, Do, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brillia Cytocarmine 6B, Eon Lake, Rhodamine Lake B, Alizarin Le Beef, Brilliant Carmine 3B.

Purple pigment Manganese Purple, Fast Violet B, Methyl Violet Lake.

Blue pigments navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, first sky blue, indane strenblue.
B.C.

Green pigment chrome green, chromium oxide, pigment green B1
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, iron inotrium oxide, cadmium oxide, copper iron oxide, iron oxide complex, neodymium iron oxide, barium iron oxide, iron manganese oxide, Although lanthanum iron oxide, iron powder, cobalt powder, ferrous powder, etc. are known, 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, polyethylene wax, polypropylene wax, etc. are used as anti-offset agents, 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 μm, as measured by a call counter.
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 size of the resin fine particles is preferably 0.05 to 5 μl, more preferably 0.1 to 4 μm. In particular, dispersion polymerization,
Acrylic fine particles having an average particle size of 0.1 to 4 μm obtained by emulsion polymerization, soap-free polymerization, and pulverization are preferred.

These resin particles are treated with a surface treatment agent, and examples of the surface treatment agent include a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, etc., and at least one of these coupling agents is used. One type is selected.

Examples of silane coupling agents include vinyltrichlorosilane, vinyltris (β-methoxyethoxysilane),
Silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxybripyltrimethoxysilane, β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, γ-glyndoxybrobyltrimethoxysilane, γ-glycyl Dokinpropylmethyljetoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminobrobyltriethoxysilane, N-phenyl- Examples include γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane.

Examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isofurobil tridecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, and tetraisopropyl bis(dioctyl phosphite).
Titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl) bis(di-tridecyl) phosphite titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene natanate, imebrovir trioctanoyl titanate, isopropyl dimethacrylylisostearoyl titanate, isopropyl isostearoylyldiacryl titanate, isopropyl tri(
dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, inpropyl tri(N-
Examples include amituyutyl-aminoethyl) titanate.

Examples of the aluminum coupling agent include acetalkoxyaluminum diisopropylate.

The treatment amount of these surface treatment agents is 0.1
It is preferably from 10% by weight, more preferably from 05 to 5% by weight. If the treatment amount of the surface treatment agent is less than 0.1% by weight, the effect of improving the fluidity of the resin particles, the dispersibility of the resin particles, and the fluidity of the toner will be reduced; if it is more than 10% by weight, On the contrary, the fluidity of the resin particles tends to decrease.

Processing the surface treatment agent into fine particles can be carried out using various conventionally known methods and devices. For example, the resin fine particles are immersed in a solution in which the surface treatment agent is dissolved in a solvent, or the solution is mixed with the resin. It can be applied to fine particles and then dried.

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 per toner, and the toner powder, resin fine particles and, if necessary, fluidity modifiers may be added to the toner. The toner according to the present invention is obtained by muffing the property improver in a mixer.

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

(Effects of the Invention) According to the present invention, by treating the fine particles with a surface treatment agent, 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.

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

Cliff 1 Styrene acrylic resin 100 parts by weight Carbon black (manufactured by Mitsubishi Kasei Co., Ltd., MA-100) 10 parts by weight Charge control agent (manufactured by Orient Chemical Co., Ltd., Bontron S-34
) 1 part by weight polypropylene (manufactured by Mitsubishi Kasei Corporation, Viscol 550P)
A mixture consisting of 2 parts by weight of the above formulation was melt-kneaded, then pulverized using a jet mill and classified to obtain toner powder with an average particle size of 11.0 μm.

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, potassium persulfate (OJ), and 0.3 parts by weight of polyvinyl alcohol were added, and a reaction was carried out at 80°C in a nitrogen stream for 4 hours. 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.

Acrylic fine particles obtained above 100 parts by weight vinyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE 1003)
3 parts by weight Methanol 50 parts by weight 11 parts The above formulation was coated using a fluidized bed coating device and 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 parts by weight using a Henschel mixer.

A developer was prepared by mixing 4 parts by weight of this toner with 96 parts by weight of a ferrite carrier having an average particle size of 80 μm, and this developer was loaded into a modified DC-5585 machine manufactured by Sanda Kogyo ■, which produced 100,000 images. I made a delivery. Table 1 shows the results.
Shown below.

Oarashi Daisho Vinyl Triet Beef/Silan (manufactured by Shin-Etsu Chemical Co., Ltd., X, BE
1003) Instead of 3 parts by weight, γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE
A toner was obtained in the same manner as in Example 1 except that 3 parts by weight of 503) was used. Regarding the obtained toner, Example 1
The same evaluation was conducted. 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 Tomoka Takumi-treated fine powder. 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 (ID, ) and fog density (F, D,) increased after 100,000 sheets of printing, and even when untreated resin fine powder was used (Comparative Example 2), the image density (ID, ) and fog density (F, D,) increased after printing It was confirmed that while the fog density (F, D,) of the images increased, the image density and image characteristics of the present example were satisfactory in all cases.

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 an electrostatic image, which is treated with at least one surface treatment agent selected from the group consisting of a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent.