JPH026965A - Developing material for developing electrostatic latent image - Google Patents

Abstract

PURPOSE:To improve ease of handling by holding a developer formed by dispersing a coloring agent into an electrical insulating org. material which is solid at ordinary temp. and makes a solid-liquid change by heating and cooling on a base body having an electrical conductivity. CONSTITUTION:The developer 2 formed by dispersing the coloring agent in the electrical insulating org. material which is solid at least at ordinary temp. and makes solid-liquid change by heating and cooling is held on the base body 1 having the electrical conductivity. This developer 2, therefore, functions as a wet process developer when the developer is brought into contact with an electrostatic latent image in a heated state. The ratio of the coloring agent is preferably 0.01-100g, more preferably 0.1-10g per 1l molten state of the electrical insulating org. material. The formation of the developer to a sheet or tape form is possible in this way and the ease of handling the developer is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developer for developing an electrostatic latent image by wet developing an electrostatic latent image formed by an electrophotographic process, etc. The present invention relates to a novel developer for developing electrostatic latent images that can be used as a tape, sheet, etc. although it is a developer.

[Conventional technology]

In the field of image forming technology, a method of selectively irradiating light on a photoconductor charged in the negative direction according to an image signal and developing the formed electrostatic latent image is known as -71 electrostatic photography. called a process.

In such an electrostatic photographic process, dry development methods and wet development methods are known as methods for developing electrostatic latent images, and "each has advantages and disadvantages, so they are used depending on the purpose etc." is the current situation.

For example, the dry development method, in principle, simply scatters and adheres colorant powder to the electrostatic latent image, so it has the advantage of being easy to handle and has excellent toner storage stability. The reality is that in order to meet the increasing demand for high-quality images in recent years, as seen in printers, etc., we have no choice but to give way to wet developing methods.

On the other hand, the wet development method uses a liquid developer in which dyes or pigments as colorants are dispersed in an insulating liquid medium, and it is possible to obtain resolution and gradation comparable to silver halide photography. In addition, the use of pigments as colorants has the advantage that the formed image has excellent weather resistance, but since the developer is a liquid, it is not possible to produce images that are always stable, for example. In order to realize this formation, frequent maintenance is required, which is very disadvantageous in terms of ease of handling.

[Problem to be solved by the invention]

Incidentally, regardless of whether the dry developing method or the wet developing method is used, the developing devices used generally tend to have complicated and large-scale device configurations, and are not suitable for use in, for example, consumer image forming devices such as those for home use. is difficult.

Under these circumstances, in order to simplify the device configuration, for example, in the video printers mentioned above, many use a sublimation thermal transfer method or inkjet method, in which sublimation ink is vaporized by a thermal head and transferred to recording paper. .

However, these methods naturally fall short of the electrostatic photographic process mentioned above in terms of resolution, single gradation, etc.
Furthermore, it is almost impossible to form an image comparable to silver halide photography.

Therefore, the present invention has been proposed in view of the conventional situation, and is a novel method for developing electrostatic latent images that has both the high image quality achieved by wet development and the ease of handling equivalent to that of the Kenka type thermal transfer method. The purpose is to provide developing materials.

A further object of the present invention is to provide a developer +4 for developing an electrostatic latent image, which is capable of controlling the 4 degrees, 1 gradation, 1 color balance, etc. of an image by applying a bias voltage.

[Means to solve the problem]

As a result of extensive research in order to achieve the above-mentioned objective, the present inventors have discovered that, in place of the conventional liquid electrically insulating medium,
By using organic substances that are solid at room temperature and change into solid-liquid when heated and cooled, easy-to-use developers can be made into sheets or tapes, which greatly improves their handling. They have discovered that by making the substrate conductive when it is made into a tape, it is possible to easily apply a bias voltage during development.

The present invention has been completed based on such knowledge, and a developer comprising a coloring agent dispersed in an electrically insulating organic material that is solid at least at room temperature and changes into a solid-liquid upon heating and cooling is a conductive substrate. It is characterized by being held in

Here, the conductive substrate may be one in which the substrate itself is made of a conductive material, or one in which a conductive layer is formed on a base material made of a non-conductive material. good.

Further, the developer held on the substrate may be of a single color, such as yellow, magenta, or cyan.

Furthermore, if necessary, a blank or the like in which colorants of mutually different colors are dispersed may be used.

In the latter case, a full-color image can be formed by applying developer of each color separately in predetermined areas, and by sequentially developing an electrostatic latent image with the developer in each area.

Furthermore, when developer regions of multiple colors are formed, some kind of color mixture prevention layer may be provided between each developer region in order to prevent color mixing between the developer materials, especially when the developer becomes liquid due to heating.

[Effect]

In the developer for developing electrostatic latent images of the present invention, the developer held on the substrate changes into a solid-liquid by heating and cooling, and functions as a wet developer by bringing it into contact with the electrostatic latent image in a heated state.

Furthermore, since the developer is held on the substrate, it can be handled in the form of a sheet, tape, etc., similar to a sublimation ink film, and its handling and storage stability are greatly improved.

Further, since the substrate is conductive, a bias voltage can be easily applied during development, the degree of adhesion of the colorant is controlled, and the density, single gradation, single color balance, etc. can be adjusted.

〔Example〕

Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings.

First, prior to explaining the examples, the developer used in each example will be explained.

The developer used in the present invention is made by dispersing a colorant in an electrically insulating organic substance that is solid at least at room temperature and changes into a solid-liquid state when heated and cooled.

Here, the electrically insulating organic substance is an organic substance that is solid at least at room temperature. The melting point is set to be 30°C or higher, more preferably 40°C or higher, taking into consideration the normal usage environment and ease of handling. The upper limit of the melting point is not particularly specified, but
Practically, the temperature is about 100°C, more preferably 80°C or less. This is done considering the following considerations: even if the melting point is too high, extra energy will be consumed for heating, and when forming on a substrate, it must not exceed the heat-resistant temperature of the material generally used as the substrate. That's what it means.

Materials that meet these requirements include paraffins, waxes, and mixtures thereof. First, as paraffins, there are various normal paraffins having 19 to 60 carbon atoms, ranging from nonadecane to 1-sacontane. Examples of waxes include vegetable waxes such as carnauba wax and cotton wax, animal waxes such as beeswax, ozucerite, paraffin wax, and petroleum waxes such as microcrystalline petrolatum. These 14 materials have a dielectric constant ε of 1.9 to
It is a dielectric material of about 2.3.

Furthermore, polyethylene, polyacrylamide, and homopolymers or copolymers of polyacrylates such as poly n-stearyl acrylate and poly n-stearyl methacrylate (e.g., Copo 17 n-stearyl acrylate ethyl methacrylate, etc.) have long alkyl groups in their side chains. Although crystalline polymers can also be used, the above-mentioned paraffins 1 and waxes are preferable in consideration of viscosity upon heating.

Further, as the colorant to be dispersed in the electrically insulating organic substance ζ, conventionally known inorganic pigments, organic pigments, dyes, and mixtures thereof can be used.

Examples of inorganic pigments include chromium pigments, cadmium pigments, iron pigments, cobalt pigments, ultramarine blue, and navy blue. In addition, organic pigments and dyes include Hansa Yellow (C, 1, 1) 680), Benzidine Yellow G
(C, 1, 21090), Hengejin Orange (C,
1,21) 10), Fast Red (C,I, 37
(185), Brilliant Karmitsu 3 B (C, 1,
16015-Lake), Fuclocyanine Blue (C
, 1,74160), Victoria Blue (C, 1,42
595-Lake), Spirit Black (C, 1,
50415), oil blue (C, 1,74350)
, Alkali Blue (C, 1,4277OA), First Scarlenote (C, 1, 12315), Rhodamine 6 B (C, 1, 45160), Rhodamine Lake (C, 1, 45160-Lake), First Sky Blue ( C, 1,74200-Lake), nigrosine (C, 1,50415), carbon blank, and the like.

These can be used alone or as a mixture of two or more types, and those having the desired color development may be selected and used.

In addition to these electrically insulating organic substances and colorants, the developer contains
A resin may be used in combination for the purpose of improving dispersibility and fixing properties of the colorant. As such resin, known materials can be selected and used as appropriate; examples include butadiene rubber,
Rubbers such as styrene-butadiene rubber, cyclized rubber, and natural rubber; synthetic resins such as styrene resins, vinyltoluene resins, acrylic resins, methacrylic resins, polyester resins, polycarbonate resins, and polyvinyl acetate resins. , rosin resins, hydrogenated rosin resins, alkyd resins containing modified alkyds such as linseed oil modified alkyd resins, and natural resins such as polyterpenes.

In addition, phenolic resins such as JIWffl, phenol-formalin resin, pentaerythritol phthalate, coumaron-indene resins, ester gum resins, and vegetable oil polyamide resins are also useful, and polyvinyl chloride and chlorine halogenated hydrocarbon polymers such as polypropylene, vinyltoluene-butadiene,
Synthetic rubbers such as butadiene-isoprene, polymers of acrylic monomers with long chain alkyl groups such as 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, lauryl acrylate-1, octyl acrylate, or these and other Polymerizable nanatsumer
Copolymers ji (for example, styrene-lauryl methacrylate copolymer, acrylic acid-lauryl methacrylate-1 copolymer, etc.), polyolefins such as polyethylene, polyterpenes, etc. can also be used.

Furthermore, a charge donating agent is usually added to the developer described above, and the developer used here is no exception. The intermold donor agents used are, for example, naphthenic acid, octenoic acid,
Metal salts of fatty acids such as oleic acid, stearic acid, isostearic acid or lauric acid, metal salts of sulfosuccinates, oil-soluble sulfonic acid metal salts, phosphoric acid ester metal salts, metal salts such as abietic acid, metal aromatic carboxylic acids salts, aromatic sulfonic acid metal salts, etc.

In addition, in order to improve the electrostatic charge of the colorant, Sin,
,A#,O,,Tie,,Zn○,Ga! Off.

I n203. GQOz, SnO, Pb()z, Mg
Fine particles of metal oxide such as O or a mixture thereof may be added as a charge enhancer.

Regarding the blending ratio of each component described in -L, the coloring agent is preferably 0.01 to 100 g, more preferably 0.1 to 10 g, based on the molten M1) for electrical insulation. . In addition, the charge donor is usually 0.001 for the same <2
-10g, preferably 0.01-1g. Furthermore, the charge enhancer is not more than twice the weight ratio of the colorant,
Preferably, it is added in the same amount or less.

The developer described in (1) is held on a conductive substrate to form a developer for developing an electrostatic latent image, and the structure of each example will be explained below.

FIG. 1 shows 1) the one having the simplest structure among the developing materials to which the present invention is applied, in which the previous developer ( 2) is applied to the entire surface.

The material of the conductive substrate (1) needs to be conductive in this case and is therefore, for example, AI.

Metals such as Cu, stainless steel, Ni, NiCr, Ag,
Conductive ceramics, carbon, 5iC1■To (In
(dium Tin Oxide), SnO2, conductive polymers, etc. are used.

In addition, if the base itself does not have conductivity, 1. as shown in FIG. After forming the conductive material layer (4) on the surface of the base (3), the developer (2) may be formed thereon.

In this case, the conductive material layer (4) may be formed by directly depositing a film of metal, etc., using methods such as vapor deposition, spanotame, and ki, or may be formed using a material in which R conductive particles are dispersed, such as silver paste. It may be formed by applying.

In addition, as the non-conductive substrate (3), polymer films such as polyethylene terephthalate, polypropylene, polycarbonate, polyamide, paper (natural paper, synthetic paper, etc.), and composite materials thereof are used. Generally, a flexible material is used, but it is not necessarily necessary to have flexibility.

FIG. 3 shows an example in which a porous substrate is used, and the developer (2) is impregnated and held in a solidified form on the porous substrate (5). In this example, porous'! [A conductive material layer (4) is formed on the back side of the plate (5) to ensure conductivity.

The porous substrate (5) is impregnated with the developer (2) and the IJ
Any paper may be used as long as it is natural paper1
In addition to paper such as synthetic paper, vegetable fibers such as cotton and hemp, natural fibers such as animal fibers such as wool, organic materials such as polyamide, polyester, polyacetal, and polyurethane, glass, ceramics, carbon, etc. Fabrics made of synthetic fibers made of inorganic materials, non-woven fabrics, etc. can be used. Furthermore, it may be a metal, an n-machine polymer mesh, a polymer foam such as polyurethane foam, or the like.

The porous substrate (5) in which the developer (2) has been impregnated and assimilated is lined and reinforced with a sheet-like conductive substrate (1) having conductivity, as shown in FIG. , conductivity may be ensured.

Furthermore, as shown in FIG. 5, the porous substrate (5) impregnated and solidified with the developer (2) is laminated with the base (3) provided with the conductive material layer (4) at L7. good.

Alternatively, the developer held on the substrate may be compatible with a plurality of colors, and each color region may be formed by separately painting on one substrate.

For example, FIG. 6 shows a substrate (3) on which a conductive material layer (4) is formed.
) A yellow developer layer Y, a magenta developer layer M, and a cyan developer layer C are formed on the top, making it possible to form a full-color image. In addition, when forming a full-color image, in addition to the above-mentioned yellow, mazeshita, and cyan colors, a black developer layer region may be added as necessary.

Similarly, as shown in FIG. 7, yellow developer Y and magenta developer are applied to the porous substrate (5) laminated on the substrate (3) on which the conductive jtA layer (4) is formed. agent M,
A cyan developer C may be impregnated and assimilated in each region,
Of course, as shown in FIG.
, Mazenk color developer M.

Porous substrate impregnated with cyan developer C (5)
can also be used as is as a developer for developing electrostatic latent images. However, in the latter case, it is necessary to form a conductive material layer (4) on the back surface of the porous substrate (5) to ensure conductivity.

By the way, when developer regions of a plurality of colors are formed on the same substrate as described above, there is a possibility that color mixing may occur particularly during heating and melting.

Therefore, as shown in FIG. 9, for example, the developer Y of each color,
A color mixture prevention layer (6) may be provided between the M and C regions.

This color mixture prevention IN (6) plays the role of spacing and may be of any type, but is particularly suitable for use with the porous substrate (5) described in the liquid-absorbing shrine 14 (for example, 1j1). It is preferable to use similar 4A1)1) or 18 liquid material l:I.

Moreover, as shown in FIG. 7 or FIG. 8, porous 1.
When the V body (5) is impregnated and solidified with the developers Y, M, and C of each color, if the developer regions of each color are formed at predetermined intervals, the porous substrate (5a) between each region is formed! j'f
3[! It functions as a color mixture prevention layer.

The following method may be used to develop an electrostatic latent image using the above-mentioned developer for developing an electrostatic latent image.

Hereinafter, a method of developing an electrostatic latent image will be explained using the embodiment shown in FIG. 2 as an example.

As shown in FIG. 9, the photosensitive substrate (7) is formed by forming a photosensitive layer (7b) on, for example, a sheet-like substrate (7a), and the photosensitive layer (7b) is subjected to a charging process. A latent image of negative charge corresponding to the image information is formed by the exposure step.

Here, the negative charge (1
To develop the photosensitive substrate (7) on which a latent image of f is formed: 1. It is sufficient to simply align the wheels so that the developer (2) comes into contact with the photosensitive layer (7b), and send it out while being pressed by a single call (8) provided with one heating stage.

In this way, the truth is 1f'! (2) and photosensitive layer (71'l
) When the roll (8) L::J is heated, the developer (2) becomes liquid and the colorant (9) contained in the developer (2) is heated. Then move towards the charged area and attach it to the floor. Thereafter, an image is formed on the photosensitive substrate (7) by removing the colorant (9) adhering to unnecessary portions and performing a static elimination process, a fixing process, etc.

In addition, during development, if the photosensitive substrate (7) and the developer (2) solidify immediately after contact, there is a risk of degrading the image quality.
It is preferable that a heating means is also provided on the stage etc. on which the material is fixed to heat it.

Moreover, since the conductive material layer (4) is formed on the base (3), this >5 electric +4'f? M(4)
0) All connections can be made and a bias voltage can be applied during development.

By applying this bias voltage, the relative potential of the electrostatic latent image can be controlled, and the degree of adhesion of the coloring material (9) to the electrostatic latent image can be controlled.

The heating means for the roll (8) can be omitted by applying an AC voltage to the conductive material layer (4) at the same time as applying a bias voltage, and using the conductive material layer itself as a heating element. Further, since the conductive material layer (4) is formed of a material with good thermal conductivity such as metal, the heating temperature for the developer (2) becomes uniform, which is also advantageous.

In fact, when the present inventors produced a sheet-like developing material as described above and attempted to develop an electrostatic latent image, they were able to stably produce images with excellent resolution and sharpness, comparable to silver halide photography. Obtained.

5 Examples of the present invention have been described, but it goes without saying that the present invention is not limited to these examples, and changes in materials, shapes, etc. can be made without departing from the gist of the present invention. It is.

If an electrostatic latent image is developed, it is possible to obtain the same image quality as the wet development method, and it is suitable from the viewpoint of waste disposal, such as being able to be disposed of as is after use.

Furthermore, in the developing material for developing electrostatic latent images of the present invention, since the substrate has conductivity, a bias voltage can be applied during development, and the density, single gradation, single color balance, etc. of the image can be adjusted. be able to.

In addition, by making the base conductive, external heating means can be omitted, heating temperature can be made uniform, etc.
There are also great additional benefits.

〔Effect of the invention〕

As is clear from the above description, the developer material for developing electrostatic latent images of the present invention has a developer retained in the base material, so it is extremely easy to handle, similar to, for example, sublimation ink ribbons. Therefore, it is possible to greatly simplify the developing operation and the developing device.

Furthermore, using the developer material for developing electrostatic latent images of the present invention,

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the main part of an embodiment using a conductive substrate, FIG. 2 is an enlarged sectional view of the main part of an embodiment using a substrate with a conductive layer, and FIG. FIG. 4 is an enlarged sectional view of the main part showing an example in which a conductive material layer is formed using a porous substrate. FIG. 4 is an enlarged sectional view of the main part showing an example in which a porous substrate is lined with a conductive material layer. FIG. 2 is an enlarged cross-sectional view of a main part showing an example in which a solid substrate is lined with a substrate having a conductive material layer. Figure 6 shows multiple developers on a substrate having a conductive material layer? ij
FIG. 7 is an enlarged cross-sectional view of a main part showing an example in which an i-area is formed, and FIG. Figure 8 is an enlarged cross-sectional view of main parts showing an example in which a conductive material layer is provided on a porous substrate in which a plurality of developer regions are formed and a developer material is used, and Figure 9 is an embodiment in which a color mixing prevention layer is provided. FIG. 2 is an enlarged sectional view of a main part showing an example. FIG. 1O is a schematic diagram illustrating a method of developing an electrostatic latent image using the developing material of the present invention. ■...Conductive substrate 2...Developer 3...Porous substrate 4...Conductive material layer 6...Color mixture prevention layer Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) An electrostatic latent image characterized in that a developer comprising a coloring agent dispersed in an electrically insulating organic substance that is solid at least at room temperature and changes into a solid-liquid upon heating and cooling is held on an electrically conductive substrate. Developing material for development. (2) A developer for developing an electrostatic latent image according to claim 1, characterized in that a plurality of developers in which colorants of different color development are dispersed are held on a conductive substrate in different areas. Material. (3) The developer for developing an electrostatic latent image according to claim 2, further comprising a color mixture prevention layer formed between the developer in each region.