JPS6010258A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To obtain a color toner superior in developability used for an overhead projector (OHP) by forming the toner substantially into the spheres. CONSTITUTION:The form of each toner particle is regulated to a substantially true circle, to a Wadell practical spheroidicty of 0.95-1.0, expressed by the ratio of the diameter of the circle of which the area is equal to the area of the projected image of the particle, to the diameter of the min. circle externally tangent to the projected image of the particle. The toner has a number average diameter of 5-25mum. A dye subliming or evaporating in the temp. range of 70- 240 deg.C is incorporated in the toner to obtain a color toner for use in an OHP. The spherical toner is prepared by suspension polymerizing a polymerizable monomer, such as styrene or vinyl monomer, in water in the presence of a suspension stabilizer, such as barium sulfate or magnesium carbonate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing electrostatic images used for clear transfer onto a transparent support.

Conventionally, characters, images, etc. are written on a transparent support using black or chromatic ink, etc. A method is known in which the image is projected onto a white surface or white board using a projector or the like. (Hereinafter referred to as OHP) This is because for black, the non-image area transmits light well and the image area absorbs light, thereby projecting multiple images. On the other hand, for tangible colors, different from black, it is necessary to transmit well the wavelength peculiar to that color, and the image area is required to be transparent like the non-image area.

The inks currently in use have good properties of transparency, color, and ink, and are widely used. , the image cannot be projected faithfully. As a means of faithfully reproducing and projecting the original images of these printed materials, types, etc., a method has been used in which an electric latent image is developed using black toner and transferred onto a transparent support. These black toners on transparent supports absorb light well and achieve their purpose.

Toner is not provided. This is due to the insufficient transparency of the image area formed by toner particles.

It is also attributable to diffuse reflection due to unevenness on the surface of the image area. For these reasons, chromatic toners used for OUP are required to have different and far more advanced characteristics than black toners. That is, it is required to be transparent, to have a smooth surface with no unevenness in the image area, and to have sufficient color density.

At present, chromatic toners are required to have the same performance as black toners, such that they can be used for ordinary copying purposes, and at the same time, they can also be used for OHP purposes.

However, as described above, the chromatic toner and the black toner have completely different mechanisms of action, so it is necessary to solve a difficult problem to realize this. That is, high pressure and high temperature are required in the fixing section in order to increase the smoothness of the surface of the image area in order to reduce diffuse reflection.

This is because, in order to improve the surface smoothness by using low pressure and low temperature, it is necessary to extremely lower the Tg and softening point of the toner. This makes it difficult to satisfy the performance generally required for toners, such as no blocking, no contamination of the photoreceptor surface, no deterioration during durability, and no deterioration of triboelectric charging properties.

As described above, when conventional chromatic toners are used for OHP applications, they have various drawbacks and are insufficient for practical use.

The present invention provides a novel 0) that overcomes the drawbacks of the above-mentioned toner.
The present invention provides colored toner for IP use. One of the objects of the present invention is to provide a colored toner for OHP with excellent developability. Another object of the present invention is to provide a colored toner with excellent developability.

Another object of the present invention is to provide a spherical colored toner with excellent fluidity. Another object of the present invention is to provide a colored toner with stable chargeability.

The above aspects of the present invention include toner having a substantially spherical shape with a wobble practical sphericity of 0.95 to 1.00, a number average diameter of 5 to 25 μm, and a toner of 70° to 24 μm.
This is accomplished with an electrostatic image developing toner containing a dye that sublimes or evaporates in the temperature range of 0°C.

In the present invention, if the practical sphericity of the wobble is 0.95 or less, it is substantially the same as an amorphous shape, frictional charging becomes uneven, fluidity decreases, and developability is poor, which is undesirable. . Moreover, if the number average diameter is 5 μm or less, the fluidity is poor and capriulation is likely to occur, resulting in poor developability, which is not preferable. Moreover, if it is 25 An or more, the image performance during development such as poor fine line reproducibility of the image is deteriorated, which is not preferable.

As a method for producing this toner, a suspension polymerization method is preferred. Suspension polymerization is a method in which, for example, polymerizable monomers, colorants, initiators, and other additives are suspended in water and polymerized in the presence of a dispersion stabilizer to obtain particles with uniform diameters. be. Examples of positional properties using the suspension polymerization method include the following.

In other words, the suspension polymerization method generally allows polymerization at low temperatures, depending on the type of initiator and the amount used, and can effectively use dyes that easily sublime or evaporate at low temperatures. . This means that the dye can be easily transferred onto a transparent support.Furthermore, since the dye is mixed and dispersed in a liquid monomer, uniform dispersion of the dye can be easily achieved.

Furthermore, as the polymerization progresses, these dyes tend to exist inside the particles without collecting on the particle interface, which has the great advantage of not changing the triboelectric charging properties, which are important properties for electrophotography, electrostatic printing, etc. have.

Next, the usage mode of the toner of the present invention will be explained. First, the colored toner of the present invention is transferred onto a support such as paper by a method such as electrophotography, electrostatic printing, or magnetic printing. It may be fixed if necessary. Thereafter, it is superimposed on a transparent support and the sublimable dye is transferred onto the transparent support using heat or pressure. As a result, an image with chromatic colors that faithfully reproduces the original image is obtained. When this transparent support is projected with a glow projector, a bright chromatic image is projected. The hue can be achieved by appropriately selecting the type of sublimable dye.

Further, the appropriate temperature and pressure during transfer is determined depending on the type of sublimable dye.

The practical sphericity Vω of the wobble, which is one of the conditions in the present invention, is a value expressed by Vω.

In addition, the number average diameter is verified and measured using a Coulter counter Type (1), an aperture diameter of 100 μm, and calibration using a styrene standard sample.

Examples of the polymerizable monomers used in the present invention include the following: (a) -Mi or two or more of these may be used. Further, one or more of these polymers may be contained in the polymerizable monomer.

Styrene, 0-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-nonylstyrene, p-ethylstyrene, 2,4-tsumethylstyrene, p-n-butylstyrene, p-tert - Styrene and derivatives thereof such as butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene.

Vinyl monomers include, for example, ethylenically unsaturated monoolefins such as ethylene, -propylene, butylene, and isobutylene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc.; acetic acid; Vinyl, vinyl esters such as vinyl propionate, vinyl penzoate, vinyl butyrate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate
-Octyl, Methacrylic Dragon P Decyl, Methacrylic Acid-2
~Ethylhexyl, stearyl meccrylate, methacrylate is phenyl, α-methylene aliphatic monocardenate esters such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylic, ethyl acrylate, n-butyl acrylate, isobutyl acrylate , propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate; vinyl methyl ether, vinyl ethyl ether, Vinyl ethers of vinyl isosotylether; vinyl methyl ketone, vinyl hexyl ketone, vinyl ketones of methyl isozolobenyl ketone; N-vinylvirol, N-vinylcarbazole, N-vinylindole,
N-viny# compounds such as N-vinyA/hy0ridone:
Vinylnaphthalenes; examples include acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylaterile, and acrylamide.

Examples of the polymerization initiator used in the present invention include oxycargonate, cumenehydrono, monooxide, 2,4-dichloroylpenzoylpenzoylmonooxide, monooxide, lauroyl/4
-Oxides etc. can be used.

In the present invention, a crosslinking agent may be used to carry out crosslinking polymerization. For example, divinylbenzene, divinylnaphthalene and derivatives thereof; for example, noethylenically carbinic esters such as diethylene glycol meccrylate, triethylene glycol methacrylate, ethylene dalycol cimec acrylate, and tetraethylene glycol dimethacrylate; 1.2 -f ropyrenguli, call, 1,3-
! The suspension method can be used to uniformly dissolve the polymerization initiator, monomers, additives, dyes and pigments, crosslinking agent if necessary, polymer, etc. Alternatively, the dispersed monomer system is dispersed in a dispersed phase, ie, a continuous phase, containing a suspension stabilizer using a conventional stirrer or homomixer/homogenizer, etc. Preferably, the monomer droplets form the desired toner particles. size, generally 30μ
Adjust the stirring speed and time to a level that has the following size, and then stir to an extent that prevents sedimentation of the particles so that the dispersion stabilizer will maintain the loose state. . Polymerization is carried out by setting the polymerization temperature appropriately. After the reaction is completed, the produced toner particles are collected by a suitable method such as filtration, decantation, centrifugation, etc. and dried. When suspension polymerizing a polymerizable monomer system in water, a suspension stabilizer is used to prevent coalescence of polymer particles as the polymerization progresses. Generally, suspension stabilizers include poorly soluble, finely powdered inorganic compounds, such as BaSO4, CaSO4, MgCO3.
, BaCO3, CaCO3.

Ca3(PO4)2. These include, but are not limited to, sparingly soluble salts such as diatomaceous earth, talc, silicic acid, clay, inorganic polymers such as talc, powders of metal oxides, and water-soluble polymers such as polyvinyl alcohol, gelatin, and starch. It's not a thing. These suspension stabilizers are usually used in an amount of 0.1 to 20% by weight.

Further, a surfactant may be used in an amount of 0.0 to 0.1% by weight for fine dispersion of the hardly soluble, finely powdered inorganic compound. Examples of surfactants used for such purposes include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium allyl-alkyl polyether sulfonate, and sodium oleate, and polyoxyethylene alkyl ether. Nonionic surfactants such as polyoxyethylene alkyl allyl ether are commonly used.

All known methods can be used to develop this toner. For example, two-component development methods such as the cascade method, magnetic brush method, and microtoning method; one-component development methods containing a magnetic material such as the conducting-component development method, the insulating-component development method, and the jumping development method. Development methods: Powder cloud method and fur brush method; Non-magnetic component development method in which the toner is held by electrostatic force in the toner-carrying potting soil and transported to the developing area, where it appears. I can do it.

The dye that sublimes or evaporates in the temperature range of 70 DEG to 240 DEG C. used in the present invention may be arbitrarily selected from disperse dyes, basic dyes, and fatty dyes. For example 1,4-
Cyamino-2,3-dichloro-anthraquinone, l-amino-2-phenoxy-4-hydroxy-anthraquinone, 3-hydroxy-quinophthalone, 1-amino-2-cyano-4-anilide-anthraquinone, 1,
Dyes such as 4-cybide draw, 5-amino-8-ingropyruamino-anthraquinone, etc. are used.

Here, if the temperature of sublimation or evaporation is 70° C. or lower, a negative Vt-reception is likely to occur with respect to the temperature during polymerization, and there is a possibility that the chargeability of the obtained toner will be adversely affected. Also 24
If the temperature is 0°C or higher, the OHP film itself. is extremely softened by heat and easily deforms, which may cause problems in practical use.

The amount of the dye used is 1 to 1 part per 100 parts of resin.
0i parts is appropriate.

As other colorants, arbitrary dyes and pigments can be used as appropriate. For example, calf 1? Examples include phthalocyanine blue, phthalocyanine green, nigrosine dye, and magnetic materials.

Next, the present invention will be explained with reference to examples.

Example 1 Styrene 200JF-, azobisisobutyronitri/I
/ 8 f% Heliofast Vine 1 oy-, Ceres Yellow R (manufactured by Bayer) 5y-woT, and about 1 o min in a container equipped with a high shear force mixing device such as Homomixer (manufactured by Tokushu Kogyo Co., Ltd.). Mixed evenly. During this time, the temperature rose to about 55°C. During this time, the pigment and dye were uniformly dispersed in the styrene monomer.

2? 600 polyvinyl alcohol? The mixture was dispersed in water using the homomixer described above and kept at 70°C. The above slurry was added to this system under stirring using a TK Hoshichi mixer and heated at 4000 r.
I pressed the bond for 30 minutes at pm. The reaction mixture system was stirred using a nof dollar blade to complete the polymerization. After washing with water, filtering and drying, a toner having an average particle size of 11.0 μm was obtained. (Using Coulter Counter, 100μA) This toner is substantially spherical, with a Wardell practical sphericity of 0.95 to 1.0.
It was between 0. This toner was mixed with 200/300 Messier iron powder at 10%, and the toner was measured using the pro-off method.Results were -1-f3. Ottc/l' was obtained. Further, when this toner was used as a two-component developer and subjected to reversal development using NP-5000, a good image was obtained. A polyester film was placed on top of this image and passed through a heating roller at a temperature of 180° C. to obtain a clear yellow transferred image. When this film was projected using a Norozoector, a yellow image faithful to the original was projected. Further, even in a durability test of 30,000 sheets, there was little change in image density and there was no problem in practical use.

Example 2 Styrene 200? , azobisisobutyronitrile 8! y
-, Nigrosin 4f, BL-200120! y-1 sublimation dye (1-amino-2-phenoxy-4-hydroxy-anthraquinone) IOIf was polymerized in the same manner as in Example 1 and dried to obtain a black toner.

The number average was 11.0μ, and the practical sphericity of the wobble was between 0.95 and 1.00.

Good images could be obtained using PC-10.

As in Example 1, overlap the polyester films and
After transferring at ℃ temperature, a clear red image was obtained. When this film was projected using a Norono Ector, a red image faithful to the original was projected.

Claims (1)

[Claims] 1. The toner has a substantially spherical shape with a wobble practical sphericity of 0.95 to 1.00, a number average diameter of 5 to 25 μm, and a temperature range of 70° to 240°C. 1. A toner for developing an electrostatic image, comprising a dye that sublimes or evaporates. 2. The toner for developing electrostatic images according to claim 1, which is produced by a suspension polymerization method.