JPS6396663A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To prevent a powder toner from filming due to a metal salt and melt attaching in streaks to the surface of a photosensitive body at the time of cleaning by incorporating a fatty acid metal salt in the powder toner in an amount of <=0.5wt% of the toner. CONSTITUTION:The powder toner composed of a binder resin, a colorant, and other additives, further, contains the fatty acid metal salt in an amount of <=0.5wt% of the total weight of the toner. The use of aluminum stearate high in electric resistance as the metal salt can prevent the toner from bleeding near the solid parts of a toner image, filming of the toner due to a small amount of the toner to be used, and melt attaching of the toner in streaks to the surface of the photosensitive body at the time of cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a toner for developing an electrostatic image, and more specifically, it relates to a toner for developing an electrostatic image, and more specifically, toner for developing an electrostatic image. The present invention relates to an electrostatic image developing toner for developing an image.

<Prior art> Conventionally, in copying machines using electrophotography, various electrostatic charges containing binder resins, colorants, etc. are used to visualize electrostatic images formed on photoreceptors using dry development. Toner for image development is used.

In the dry development method, an electrostatic image formed on the photoreceptor by charging and exposure to light is developed with the toner, and the developed toner image is transferred to a support such as transfer paper, and a heating roller or pressure roller The toner image is fixed on the support and the electrostatic charge image is visualized. Further, after the toner image is transferred to the support, the remaining toner on the photoreceptor is scraped off by a cleaning blade in order to clean the toner remaining on the photoreceptor. If this cleaning process is repeated, the photoreceptor is damaged and the toner is fused to the photoreceptor and gradually grows due to frictional heat between the photoreceptor surface and the cleaning blade.

In particular, if the photoconductor is not smooth or if there are protrusions or holes on the photoconductor, damage to the photoconductor will increase, and toner will tend to adhere in a linear manner to the surface of the photoconductor. In combination, toner smudges occur on the copied image, reducing the quality of the copied image.

In order to solve the above-mentioned problems, it is known that a large amount of lubricant or the like is added to the above-mentioned electrostatic image developing toner.

<Problems to be Solved by the Invention> However, although the addition of the above-mentioned lubricant can prevent the toner from fusing in the form of streaks on the surface of the photoconductor and protect the photoconductor, When the photoreceptor has an a-photosensitive layer, the lubricant tends to form a film on the surface of the photoreceptor because the lubricant has a high affinity with the photoreceptor. The fact that the filmed lubricant functions as an insulating layer and the fact that the surface potential of the photoreceptor having the organic photoreceptor layer is generally low leads to the photosensitive characteristics of the photoreceptor and the quality of copied images, etc. There was a problem that the In particular, when a lubricant with low electrical resistance is used, the resistance of the toner and developer becomes low, causing toner smudges near the solid areas of the image, which deteriorates the quality of copied images, etc. was there.

Purpose of the present invention The present invention has been made in view of the above problems, and even when a photoreceptor having an organic photosemiconductor layer is used as a photoreceptor, toner is fused in the form of streaks on the surface of the photoreceptor. For electrostatic image development, which protects the photoconductor and allows high-quality copies to be made over a long period of time without degrading the photoconductor's photosensitive characteristics or the characteristics of the toner or developer. The purpose is to provide toner.

Means and operation for solving the problems> The present invention has the following features:
In a powder toner containing a binder resin, a colorant, and other additives, where X is the amount of fatty acid metal salt added to 100 parts by weight of the toner, an electrostatic charge such that X satisfies the following relational expression: The image developing toner solves the above-mentioned conventional problems.

0<x≦0.5 (parts by weight) According to the electrostatic image developing toner of the present invention having the above-mentioned structure, since the amount of fatty acid metal salt added is small, filming due to the fatty acid metal salt, especially , is excellent in preventing filming in a photoreceptor having an organic photosensitive layer. Further, in addition to protecting the photoreceptor, it is possible to prevent toner from being fused in the form of streaks on the surface of the photoreceptor during cleaning.

The present invention will be explained in detail below.

The toner for developing electrostatic images of the present invention comprises a powder toner containing a binder resin, a colorant, and other additives, and a fatty acid metal salt added to the toner.

Examples of the binder resin include styrene polymers, acrylic polymers, styrene-acrylic copolymers, polyethylene, chlorinated polyethylene, polypropylene, olefin polymers such as ionomers, polyvinyl chloride, polyester, polyamide, and polyurethane. , epoxy resin, diallyl phthalate resin, silicone resin, ketone resin, polyvinyl butyral resin, phenol resin, rosin-modified phenol resin, xylene resin, rosin-modified maleic acid resin, rosin ester, petroleum resin and the like.

Examples of unsaturated monomers used in the above polymer include styrene monomers such as styrene, α-methylstyrene, 0-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-chlorostyrene; acrylic acid , methyl acrylate, ethyl acrylate, 〇-butyl acrylate, isobutyl acrylate, 〇-octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, stearyl acrylate, cyclohexyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, glycidyl acrylate, diethylaminoethyl acrylate, acrylamide, acrylonitrile, methacrylic acid, methyl methacrylate, ethyl methacrylate, 〇-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, Acrylics such as 2-ethylhexyl methacrylate, dodecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, diethylaminoethyl methacrylate, etc. or methacrylic monomers; carboxylic acids with unsaturated double bonds such as maleic acid, fumaric acid, crotonic acid, itaconic acid, or their alkyl esters, or their alkyl esters; olefinic monomers such as ethylene, propylene, butadiene, etc. Examples include vinyl acetate; vinyl chloride; vinylidene chloride, vinylpyrrolidone, and vinylnaphthalene. The above monomer is
Used alone or in combination of two or more.

Among the above polymers, those whose main component is a styrene polymer, an acrylic polymer, a styrene-acrylic copolymer, or the like are preferred. These polymers have a weight average molecular weight of ao, ooo to 200,000, especially 50,000.
It is preferably in the range of 150,000 to 150,000, and one type or a mixture of two or more types can be used.

Among the above polymers, rosin esters, rosin-modified phenolic resins, rosin maleic acid resins, epoxy resins, polyesters, cellulose polymers, polyether resins, etc. are useful for improving the triboelectric properties of toner. It is for q.

Further, when the toner is a heat fixable toner, the above polymer has a softening point of 50 to 200°C, preferably a softening point of 70 to 200°C.
One having a temperature of 170°C is preferred.

Furthermore, when the toner is a pressure-fixable toner, polymers that are easily plastically deformed such as olefinic polymers such as polyethylene and polypropylene, and polyamides are mainly used. This polymer can be used with other polymers, such as polyvinyl acetate, ethylene-vinyl acetate copolymer, hydrogenated polystyrene, hydrogenated rosin ester, aliphatic, alicyclic or aromatic petroleum resins, etc. may contain.

In addition, examples of the coloring agent include carbon black, lamp black (C, 1JjL7726B), '
) Rom Yellow (C,1, 14090), Hansa Yellow (C,1, 11B80.11880, etc.)
, benzidine yellow (C,I, 121100, etc.), suren yellow G (C,l, 70GOO),
Quinoline Yellow (C, 1, 47005), Permanent Orange GTR (C, 1, Nn12305)
, Pyrazolone Orange (C, 1, Mukai 21110),
Palkan Orange (C, 1, m211θO), Watch Young Red (C, 1JkL15865), Permanent Red (C, 1, 臘12310 etc.), Brilliant Carmine 3B (C, 1, Mukai 18105), Brilliant Carmine 6B (C, 1, 15850), DuPont Oil Red (C, 1, 28105), Pyrazolone Red (C, 1, N121120), Lysol Red (C
, 1, 15830), Rhodamine B Lake (C,
IJj145170), rake l/-/do C (C,
I.

15585), Rose Bengal (C, 1, 45
435), aniline blue (C,l, ta 504)
05), Ultramarine Blue (C, 1, Yang 7710
3), Calco oil blue (C, 1, Nl azo
ec Blue 3), methylene blue chloride (C,1, 52015), phthalocyanine blue (
C,1,Nn74160), Phthalocyanine'J-
(C, I.

Nn742GO), malachide green oxalate (C,1J142000), or C,1,5olv
ont Yellow60, C, 1,5olvcnt
Red 27, C, 1,5olvcnt Blue3
Examples include oil-soluble dyes such as No. 5 and the like. These colorants are used singly or in combination of two or more, and are used in an amount that provides a sufficient toner image density, for example, 1 to 30% by weight, preferably 2 to 20% by weight.

Further, when the toner is a magnetic toner, a magnetic material is used together with or in place of the colorant. The above-mentioned magnetic material may be any material that exhibits magnetism or is magnetizable, such as iron such as ferrite and magnetite, metals or alloys that exhibit ferromagnetism such as cobalt, nickel, and manganese, or these metals. Examples include compounds containing the following. These magnetic materials have an average particle size of 0.1 to
It has a size of about 1 micron and is usually 20 to 75% by weight, preferably 40 to 75% by weight, either alone or in combination.
0% by weight is used.

Note that, in order to control the charge of the toner for developing an electrostatic image, the toner may contain a charge control agent as another additive. Examples of the charge control agent include oil-soluble dyes such as nigrosine dye (C, IJ Beni 50415B), oil black (C, 1, N128150), and spirone black, naphthenic acid, salicylic acid, octylic acid, and fatty acids described below. Resin acids manganese, iron, cobalt, lead,
Examples include metal soaps that are metal salts of zinc, cerium, calcium, nickel, etc., metal-containing azo dyes, pyrimidine compounds, alkyl salicylic acid metal chelates, etc., and contain 0.1 to 5% by weight based on the tube resin. Preferably.

In order to prevent the toner from adhering to the ankle roller, the toner may contain an anti-offset agent, such as various waxes such as low molecular weight polypropylene, low molecular weight polyethylene, and paraffin wax, and olefin monomers having 4 or more carbon atoms. Low molecular weight olefin polymers, fatty acid amides, silicone oils, etc., are added in amounts of 0.5 to 15% per toner.
Preferably, it contains 5%.

In order to protect the photoreceptor, prevent streaky toner from forming on the surface of the photoreceptor, and obtain high-quality images without deteriorating the developer properties, the powder toner contains fatty acid metals. Salt is added.

”The fatty acid of the bipedal fatty acid metal salt has 8 to 36 carbon atoms.
saturated or unsaturated fatty acids, such as caprylic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, behenic acid,
Lignoceric acid, cerotic acid, montanic acid, oleic acid, elaidic acid, linoleic acid, lylinic acid, erucic acid, lysyllic acid, dihydroxystearic acid, cyclic fatty acid,
Examples include tribasic acids and dimer acids which are two of the above-mentioned unsaturated fatty acids. Among the above fatty acids, saturated fatty acids, particularly stearic acid, are preferred.

Further, examples of the metal of the fatty acid metal salt include various metals such as zinc, lead, iron, copper, tin, cadmium, aluminum, calcium, magnesium, nickel, cobalt, manganese, lithium, and barium. Among the above metals, aluminum is preferred. Among fatty acid metal salts, aluminum stearate is particularly preferred because it has a high electrical resistance and is less likely to bleed near solid areas of a toner image.

The fatty acid metal salt is an amount such that X satisfies the following relational expression, 0<x≦0,5 (parts by weight), where X is the part by weight of the fatty acid metal salt added to 100iJiQ parts of the toner, preferably 0 It is added in an amount of .01 to 0.5 parts by weight. If fatty acid metal salts are not added, the photoreceptor cannot be sufficiently protected, and the toner may fuse on the photoreceptor surface.
Black streaks appear in the image, reducing image quality. Also, 0
．． If it exceeds 5ffIm, filming will occur on the surface of the photoreceptor and blurring of the image will likely occur, which is undesirable.

In order to improve the fluidity of toner, hydrophobic silica may be added to toner or developer, silane coupling agent,
The toner surface may be treated with a compound having low surface tension such as silicone or a fluorine compound. Furthermore, if desired, the powder toner may be heat-treated to smooth the corners and the like in order to improve the fluidity of the toner.

The above powder toner has a particle size of 1 to 30 μm, preferably 5 μm.
The electrostatic image developing toner of the present invention is useful as either a -component toner or a two-component toner. Note that when used as a -component toner, the toner containing the above-mentioned magnetic material is used alone as a developer, and when used as a two-component toner, it is mixed with a carrier such as iron powder or glass beads and used as a developer. . The above-mentioned carrier may be an uncoated carrier such as glass beads or oxidized or unoxidized iron powder, or a magnetic material such as iron, nickel, cobalt, or ferrite, or a magnetic material such as acrylic polymer, fluorine polymer, or polyester. A coated carrier coated with m-coalescence is used, usually having a particle size of 50 to 2000 μm. Further, when using a developer consisting of the above-mentioned toner and carrier, the toner is usually used in an amount of 2 to 10% by weight.

The photoreceptor may include selenium, selenium-tellurium,
Photoreceptors such as zinc oxide, cadmium sulfide, and amorphous silicon can also be used;
Polyvinylcarbazole (PVK) Polyvinylcarbazole and 2,4,7-dolinitrofluorenone or tetranitrocyano-p-quinodimethane (T
When using an organic photoreceptor such as a photoreceptor consisting of CNQ) or a photoreceptor containing a photosensitive organic compound having a heterocycle, condensed ring, etc. in the polymer, the toner for developing electrostatic images of the present invention can be used. Particularly suitable.

The toner for developing an electrostatic image can be developed by a conventionally known developing method, for example, when it is a -component toner, it is developed by a bristle brush development method, a magnetic brush development method, or a powder cloud development method, and when it is a two-component toner, it is developed by: Developed by cascade development method, magnetic brush development method, etc.

A method for producing the toner for developing an electrostatic image according to the present invention will be briefly described below. First, a powder toner containing a binder resin, a colorant, etc. is manufactured.

This powder toner is produced by a conventionally known method, for example, by mixing and dispersing the binder resin, colorant, etc. using a heated mixer such as a hot roll or extruder, and then pulverizing it using a pulverizer such as a hammer mill or jet mill. At the same time, it can be manufactured by a method of classifying with a classifier to make the particle size uniform, or a spray drying method in which the colorant, etc. is dispersed in a solution of the binder resin and spray-dried to a predetermined particle size. can. and,
The electrostatic image developing toner of the present invention can be produced by adding a predetermined amount of the fatty acid metal salt to the above toner and uniformly mixing it using an appropriate mixer such as a ball mill or a V-type mixer. can.

<Examples> The present invention will be described in more detail below based on Examples.

Example 1 Styrene-acrylic copolymer 90% by weight as a binder resin, carbon black 7.5% by weight as a colorant, 1.5 fR amount % polypropylene as an anti-offset agent, nigrosine as a charge control agent A powder toner having an average particle size of 5 to 20 μm was prepared by a conventional method using 1.0% by weight of the dye. This toner 10 (for the IffiQ part, aluminum stearate, zinc stearate,
Lithium stearate and barium stearate were added and mixed in the proportions shown in Table 1-1 to prepare a toner for developing electrostatic images. Further, 4.5% by weight of the electrostatic image developing toner and 95.5ffJm% of a ferrite carrier having an average particle size of 50 to 80 μm were uniformly mixed in a ball mill to prepare a developer.

Then, when the electrical resistance of the above developer was measured, Table 1
The results shown in -1 were obtained.

In Table 1-1, the electrical resistance values are based on the electrical resistance values of the developer mentioned above because the toner for developing electrostatic images has a high electrical insulation property and it was difficult to accurately measure the electrical resistance of the toner itself. It shows. That is, the above electric resistance value is determined by placing 200111g of the developer into electrodes with a distance of 2 mm between the electrodes, slowly bringing a magnet closer to the poles, and moving the magnet multiple times to homogenize the developer, at a temperature of 23°C.
, is an average value of values measured five times at a relative humidity of 60±5% and an applied voltage of 500V.

In addition, a copying machine (modified model DC-1it manufactured by Sanda Kogyo Co., Ltd.) equipped with a photoreceptor that forms an organic photosensitive layer using a developer containing fatty acid metal salts in the proportions shown in Table 1-2. When the development characteristics and image characteristics were investigated, the results shown in Table 1-2 were obtained.

As is clear from Tables 1-1 and 1-2, all had high electrical resistance, and those to which fatty acid metal salts were added had good image characteristics. That is, in all cases in which no fatty acid metal salt was added, the toner melted onto the photoreceptor, but in all cases in which 0.01 parts by weight of fatty acid metal salt was added, toner melted onto the photoreceptor. There was no melting, and neither filming nor image blurring occurred. Note that among the fatty acid metal salts, aluminum stearate showed particularly high electrical resistance.

In addition, when repeated development was performed using the developer containing 0.01 part by weight of the fatty acid metal salt, high-quality images were obtained without damaging the photoreceptor or deteriorating the photosensitive characteristics of the photoreceptor. It turned out that it was possible to obtain

(Hereinafter, blank space) Example 2 Aluminum stearate was added to 100 parts by weight of the powder toner of Example 1 in the proportions shown in Table 2, and a toner for developing an electrostatic image was prepared in the same manner as in Example 1. At the same time, the development characteristics and image characteristics were investigated, and the results shown in Table 2 were obtained.

As is clear from Table 2, aluminum stearate caused filming on the photoreceptor and blurred images when added in an amount of 0.7 parts by weight, but aluminum stearate in an added amount of 0.1 to 0.50 parts by weight caused In all cases, toner adhesion to the photoreceptor, filming, and image blurring did not occur.

In addition, aluminum stearate was added to 0. O1~0.50
When development was repeated using the developer added to the overlapping portion, it was found that high-quality images could be obtained without damaging the photoreceptor or deteriorating the photosensitive characteristics of the photoreceptor.

(Hereinafter, blank space) <Effects of the Invention> As described above, according to the toner for developing electrostatic images of the present invention, since there are few addition ports of fatty acid metal salts to the toner, filming due to fatty acid metal salts can be prevented. . In addition, it has an excellent effect of protecting the photoreceptor and can prevent the toner from forming streaks on the surface of the photoreceptor. Therefore, particularly in the case of a photoreceptor having an organic photosensitive layer, the present invention has the advantage that high-quality images can be obtained without adversely affecting the photosensitive characteristics of the photoreceptor or the characteristics of the developer.

Claims (1)

[Claims] 1. In a powder toner containing a binder resin, a colorant, and other additives, when x is the weight part of fatty acid metal salt added to 100 parts by weight of this toner, x is as follows: A toner for developing electrostatic images characterized by satisfying a relational expression. 0<x≦0.5 (parts by weight) 2. The toner for developing an electrostatic image according to claim 1, wherein the fatty acid metal salt is aluminum stearate.