JPS6079361A - Toner for electrostatic charge image - Google Patents

Abstract

PURPOSE:To prevent the sticking of a toner to the surface of a photosensitive body by fixing polyvinylidene fluoride powder on the surfaces of the toner particles contg. a resin and colorants. CONSTITUTION:When a fixing system applied is a heat oven system or a heat roll system, a thermoplastic resin or a resin mixture having >40 deg.C glass transition point is used as a resin contained in toner particles. When the fixing system is a pressure fixing system, a pressure sensitive resin or a resin mixture having >40 deg.C glass transition point is used. The amount of the resin for fixing contained in the toner is >=35wt% of the total amount of the toner. The amount of a pigment for color control and a dye is <10wt% of the total amount of the toner. The toner particles are blended with 0.02-5wt% polyvinylidene fluoride powder basing on the total amount of the toner particles to fix the powder on the surfaces of the toner particles. The sticking of the resulting toner to a photosensitive body and the damage of the photosensitive body can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic image toner used for developing an electrostatic image formed on the surface of an image 11 with a magnetic brush.

An electrostatic charge image is formed on the surface of an image carrier such as zinc oxide, selenium, or magnetized cadmium coated with a photoconductor or Mylar (trade name) on the right, and this electrostatic charge image is developed using a magnetic brush method. Transfer the toner image onto a transfer sheet,
Electrophotographic reproduction methods, which are then fixed to obtain the final image, are well known.

In the magnetic brush method described above, a mixed powder of magnetic carrier such as iron powder, steel balls, ferrite particles, etc. and non-magnetic toner, which is insulating particles with colorant dispersed in resin, is often used as a developer. (For example, Special Publick Publication No. 53-150
No. 40, JP-A-50-56946, JP-A No. 54-1346
36g.

(Refer to the respective publications such as No. 56-11459, No. 56-11/160). In the magnetic brush development method using this two-component developer, carrier and toner are mixed and stirred at a predetermined ratio, both are triboelectrically charged, and the 1-toner is charged to a predetermined polarity to transfer only the toner onto the surface of the image carrier. It has the advantage of being easy to transfer because it uses an insulating toner.

Other known magnetic developers include one-component magnetic toners whose main components are resin and magnetic powder (for example,
(See Japanese Unexamined Patent Publications Nos. 49-4532, 50-50042, and 57'-9754).

However, these magnetic developers are
When used in this method, there is a problem that toner particles adhere to and cover the surface of the photoreceptor, or the surface of the photoreceptor is damaged by the toner particles. For example, in a two-component developer, the toner particles are made of a thermoplastic resin with a fine particle size (5 to 30 μm) and a relatively low melting point (90 to 110°C) from the viewpoint of fixing properties. Therefore, it becomes easier to attach to the surface of the photoreceptor. In addition, if the toner remaining on the surface of the photoreceptor after transfer is cleaned with a mechanical means such as a blade, l.
The toner easily collapses and is forced into the photoreceptor surface, damaging it. Alternatively, in the case of magnetic toner, magnetic powder is exposed on the surface of the toner particles (for example,
6-46596), there is a problem in that the surface of the photoreceptor is easily damaged. Furthermore, in the case of toner for pressure fixing, a material that plastically deforms under low pressure is used as the resin component (see, for example, Japanese Patent Publication No. 54-3347), so the toner is easily pressed and spread, causing photosensitive Attach to the body.

An object of the present invention is to provide a toner for electrostatic images which can overcome the drawbacks of the prior art.

The present invention resides in an electrostatic image toner in which polyvinylidene fluoride powder is fixed on the surface of particles containing at least a resin and a colorant.

Ordinary toner particles contain a resin and a colorant as essential components, but as a result of study by the present inventor, by fixing polyvinylidene fluoride powder to the surface of the toner particles, the adhesion of the toner particles to the photoreceptor can be improved. It has also been discovered that damage to the photoreceptor can be effectively prevented. This polynylidene fluoride is a type of fluororesin (CF 2 =
GHQ) It has excellent mold releasability, is resistant to heat (melting point 160-180℃, heat distortion temperature 90℃, thermal decomposition temperature 380℃), and has excellent mechanical properties (tensile strength 390-520kg). /cm2.Bending rigidity 1.4~
1.8X10' kQ10m2) Therefore, Ko(7)
J: It is thought that it can have a great effect.

The blend m of polyvinylidene fluoride is preferably in the range of 0.02 to 5 ω% based on the total m of toner particles. This is 0.
This is because if it is less than 0.2ffifft%, there is no effect, and if it exceeds 5wt%, the fixing performance will be inhibited. In addition, more preferably, the blend m of polyvinylidene fluoride is 0.
．． It is in the range of 1 to 2%. Specific examples of polyfluoride and nylidene include 461, 460, 4 manufactured by Pennwald.
50.310 etc. are mentioned.

The resin used in the toner particles according to the present invention may be appropriately selected depending on the fixing method.

When the fixing method is an oven method using heating or a heat roll method such as a heat roll, for example, the following thermoplastic resins are used, such as styrenes, vinyl esters, α-methylene aliphatic monocarboxylic acids, etc. esters, acrylonitrile, methacrylic nitrile, acrylamide, vinyl ethers, vinyl ketones, N-vinyl 4 [compounds, etc.], or a combination of two or more of these monomers. Polymerized copolymers or mixtures thereof can be used. In addition, rosin-modified phenol-formalin resin, bisphenol type epoxy resin, oil-modified epoxy resin, polyurethane resin, cell [1-s resin].

Non-vinyl resins such as non-vinyl thermoplastic resins such as polyether resins and polyester resins, or mixtures thereof with vinyl resins as described above may be used.

In particular, when fixing the developed toner image by heating in an oven, bisphenol-type epoxy resins and bisphenol-type polyester resins are preferable, and when fixing using a heated roll, resins containing styrene resin as the main component, or Polyvarnish 0 chill resin is preferred. Styrenic resins have better mold releasability for culm oil containing a large styrene component. In addition, in order to improve the mold releasability against hot rolls, it is necessary to use fat 111'J acid metal salts, low molecular weight polyethylene, polypropylene, higher fatty acids having 28 or more carbon atoms, and natural or synthetic paraffins.

It is effective to add thermoplastic rubber or the like.

1. On the other hand, when the fixing method is a pressure roll type using pressure fixing, for example, the following pressure-sensitive resins are used (higher fatty acids, higher fatty acid metal salts, higher fatty acid derivatives, higher fatty acids). Amides, waxes, rosin derivatives, alkylene resins, epoxy-modified phenolic resins,
Natural side 11tt strange 1! l Phenol resin, amino 481
Grease, silicone resin, polyurethane, 11 Noah resin, polyester! 41ft, acrylic acid [Yomek 1
Examples include copolymerized oligomers of noric acids and long-chain alkyl methacrylates, Nagasaki alkyl acutokyl acrylates, long-chain alkyl methacrylates, polyolefins, ethylene-vinyl acetate copolymers, ethylene-vinyl alkyl ether-based residuals, rubbers, and the like.

These resins can be arbitrarily selected or mixed and used, but in order to not reduce the fluidity when used as a toner, resins with a glass transition point exceeding 40°C or resin mixtures are effective. It is used for fixing resin (excluding 814), ferromagnetic particles, color adjustment pigments, dyes, and charge agents, but does not reduce the fixing properties of the toner. Therefore, it is necessary to add 35% by weight or more of the total amount of toner.

As the color-adjusting pigment and dye, any of the various pigments used in general dry developers can be used. However, the content relative to the total amount of toner needs to be added within a range that does not deteriorate the electrical properties of the toner. In the present invention, the amount of these additions is 10% based on the total amount of toner.
Less than % by weight is suitable. Pigments and dyes that can be used include, for example, nigrosine dye, aniline blue, calco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green A xalate. Lamp black, rose bengal and mixtures thereof are used. If the ferromagnetic fine particles themselves are colored and there is no need to add these color modifiers, there is no need to add them to the toner.

In addition, when carbon black is used, since carbon black is an lfJi particle, it does not reduce the electrical insulation properties of the toner, so the amount is in the range of 0.01 to 1 part by weight per 100 parts by weight of the resin component of the toner. It is necessary to add it within.

The above pigments and dyes are selected in combination with ferromagnetic fine particles and fixing resin for the purpose of controlling frictional charging on the sleeve surface of the magnetic roll for toner development and on the surface of the recording medium. can be used. However, in order to control the charge of toner, is it necessary to use conventionally known dyes or pigments? Ifi? iii ill It can be added as an Ill agent. For example, nigrosine dyes that have positive 1s triboelectrification properties, nigrosine dyes modified with higher fatty acids, and metal-containing (C
r) Azo dyes can be mentioned.

The toner according to the present invention is composed of a resin, a colorant, and polyvinylidene fluoride, and may be mixed with a magnetic carrier to form a two-component developer, or may be made into a one-component developer by containing magnetic powder in the toner particles. It is also possible to remove toner.

In this case, the magnetic powder is a material that is extremely strongly magnetized in the direction of a magnetic field, such as ferrite, magnetite, etc., or an alloy or compound containing ferromagnetic elements such as iron, cobalt, or nickel, or other heat-treated materials. Various alloys exhibiting ferromagnetism can also be effectively used by subjecting them to some kind of treatment.

Since these ferromagnetic substances are contained in the toner, it is desirable that the average particle diameter is about 0.1 to 3 μm, and the amount contained in the toner is 35 to 3 μm based on the total weight of the toner.
The content is preferably 75% by weight. If it is less than 35% by weight, the magnetic force of the toner will decrease, the toner will separate from the sleeve and the image will be disturbed, and the fluidity of the toner will also decrease.
, if it exceeds 75% by weight, the fixing properties will deteriorate.

The toner according to the present invention can be prepared using the above-mentioned compositions by a known manufacturing method, such as a pulverization method or an air drying method.

Next, examples of the present invention will be described.

Example 1 24 parts by weight of wax (HIWAX200P manufactured by Mitsui Petrochemical Co., Ltd.), 16 m1n parts of ethylene vinyl acetate copolymer (Mitsui Polychemino JacP40'0) J5. J: BiF (!304 (EPT500 manufactured by Door III Industry) 60ffi
The colored portions were dry mixed, cross-mixed in a heating kneader at 160''C, cooled and solidified, and the cooled and solidified product was roughly pulverized in a ball mill, and then finely pulverized in a jet mill to obtain particles with an average particle size of 20 μm. Particles and 1.5 parts by weight of polyvinylidene fluoride (461, manufactured by Pennwalt Co., Ltd.), which has been pulverized to a size of 1μ or less, are added, mixed dry in a jet mill, fixed in a hot air stream at 120°C, and then classified to determine the particle size. 5-25μm, resistance 5X10
A toner of I4Ω·Cl11 was obtained. The obtained toner is
A copying test of 50,000 sheets was conducted using a copying machine using an e-drum (CP5.5 manufactured by Kyocera), but no conclusive slag or 1 henna was observed on the Se drum.

Comparative Example 1 A toner was prepared in the same manner as in Example 1 except that polyvinylidene fluoride was not added, and copying was performed.
Scratches on the photoreceptor were observed on about 10,000 sheets, but more severe toner sticking was observed on one portion.

Example 2 Polystyrene (Himer 5T120 manufactured by Sanyo Kasei) 12 parts by weight, amide wax (Bisamide manufactured by Nippon Kasei) 18 parts by weight
mi1 part and Fe30s (KBC-100 made by Kanto Denka)
) A toner was prepared in substantially the same manner as in Example 1, except that 65 parts by weight of polyvinylidene fluoride was dry mixed and the amount of polyvinylidene fluoride was reduced to 1M%. Thereafter, a copying test of 50,000 sheets was performed using a copying machine using a Se drum, and it was confirmed that the surface of the Se drum was good.

Comparative Example 2 A toner with the same composition as in Example 2 except polynylidene fluoride was prepared and a copy test was conducted.The toner (-JW) was found to be resistant to the photoreceptor after printing 4,000 sheets. It appeared as a black spot on the white part.

Example 3 Styrene acrylic resin (styrene-0-butyl methacrylate. Number average molecular weight 200.00, weight average molecular t
21220000) 80fffffil! A tonneau was prepared in the same manner as in Example 1 using a mixture obtained by dry mixing 10 parts of low molecular weight polypropylene (Viscol 550P manufactured by Sanyo Chemical Co., Ltd.) and 10 parts by weight of carbon black (#30 manufactured by Mitsubishi Chemical Industry Co., Ltd.). Add 1 to 5 additional parts of this to iron powder (95ffiff)
Mix part i to adjust the developer, and use a commercially available copying machine (31
) When image evaluation was performed using DC131) manufactured by Co., Ltd., the same good results as in Example 1 were obtained.

Comparative Example 3 Same as Example 3 except that polyvinylidene fluoride was not added. When a toner was prepared using Comparative Example 1 and image evaluation was performed, as with Comparative Example 1, satisfactory results were not obtained.

As described above, the present invention provides static electricity that can effectively prevent adhesion to the photoreceptor surface and damage by fixing polyvinylidene fluoride powder to the surface of particles containing at least a resin and a colorant. This invention can be expected to be useful for charge images, and can be said to be an invention with excellent practical effects.

Claims (2)

[Claims] (1) A toner for electrostatic images, characterized in that polyvinylidene fluoride powder is fixed on the surface of particles containing at least a resin and a colorant. (2) The toner for electrostatic images according to claim 1, characterized in that magnetic powder is used as at least a part of the colorant.