JPH1097027A - Image forming element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an improved transparent electrically conductive layer more effectively answering various needs of an image forming element compared with conventional case by incorporating a substrate, image forming layer and polyaniline styrene sulfonic acid. SOLUTION: This image forming element has a substrate, an image forming layer and a transparent electrically conductive layer contg. polyaniline styrene sulfonic acid preferably dispersed in a film forming binder by an amt. effective to impart antistatic performance to the electrically conductive layer. A binder useful for the antistatic layer contg. polyaniline styrene sulfonic acid is, e.g. a water-soluble polymer, a cellulose compd., a synthetic hydrophilic polymer or other synthetic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates generally to imaging elements, such as electrostatographic, ink jet and thermal imaging elements, and more particularly to imaging elements comprising a support, an imaging layer and a transparent electrically conductive layer. . More specifically, the present invention relates to a water-soluble blend of poly (styrene sulfonic acid) or a polyaniline complex of poly (styrene-co-styrene sulfonic acid) with another polymer,
It relates to the production of ones that are sufficiently transparent for photographic purposes and that can form conductive films that retain their conductivity after photographic processing, with or without the use of a protective overcoat layer.

[0002]

2. Description of the Related Art The problems associated with the generation and discharge of static charge during the manufacture and use of photographic films and photographic papers are:
It has long been recognized in the photography industry. The accumulation of charge on the surfaces of films and photographic paper can attract dust and cause physical defects. When applying a sensitized emulsion layer,
Alternatively, an irregular fog pattern or "electrostatic mark" may occur in the emulsion when the accumulated charge is discharged after application. The severity of the problems associated with static electricity has been exacerbated by the increased sensitivity of new emulsions, increased coating machine speeds, and increased post-coat drying efficiencies. The charge generated during the coating process is determined by the fact that the high dielectric polymer film base moves during the winding and rewinding operation (rewinding static electricity), when moving the coating machine (moving static electricity), and post-coating operations such as slitting and The main cause is that the spring is easily charged. Static charge can also be generated when using the final photographic film product. With automatic cameras, especially in environments with low relative humidity,
Winding and winding the film into a film cassette can create an electrostatic charge. Similarly, high speed automated film processing can generate static charges. The sheet film is likely to generate an electrostatic charge, especially when it is taken out of a light shielding package (for example, an X-ray film).

It is generally known that electrostatic charge can be effectively dissipated by including one or more electrically conductive "antistatic" layers in the film structure. The antistatic layer can be applied as a subbing layer to one or both sides of the film base, either below or on the opposite side of the photosensitive silver halide emulsion layer. The antistatic layer is
Alternatively, it can be applied on the emulsion layer or on the opposite side or both sides of the film-based emulsion layer. For some applications, an antistatic agent may be included in the emulsion layer. Alternatively, the antistatic agent can be directly included in the film base itself.

A wide variety of electrically conductive materials can be included in the antistatic layer to produce a wide range of conductivity. Most conventional antistatic schemes for photography use ionic conductors. The charge moves through the ionic conductor by the bulk diffusion of the charged species through the electrolyte. Antistatic layers containing simple inorganic salts, alkali metal salts of surfactants, ionic conductive polymers, polymer electrolytes containing alkali metal salts, and colloidal metal oxide sols (stabilized by metal salts) are already Have been described.
The conductivity of these ionic conductors typically depends strongly on the temperature and relative humidity of their environment. At low humidity and temperature, the diffusion mobility of the ions is greatly reduced and the conductivity is substantially reduced. At high humidity, antistatic back coatings often absorb water, swell and soften.
For roll films, this results in the back coating sticking to the emulsion side of the film. Also, many of the inorganic salts, polymer electrolytes and low molecular weight surfactants used are water soluble and will seep out of the antistatic layer during processing, resulting in a loss of antistatic function.

[0005] Colloidal metal oxide sols that exhibit ionic or electronic conductivity when included in an antistatic layer are often used in imaging elements. Typically, these sols are stabilized with alkali metal salts or anionic surfactants. Using a thin antistatic layer consisting of a gelled network of colloidal metal oxide particles (e.g., silica, antimony pentoxide, alumina, titania, stannic oxide, zirconia), with an optional polymer binder, Improving the adhesion to both the support and the emulsion layer thereon is described in EP 250,250.
No. 154. Optionally, both functions (a
Mbifunctional silane or titanate coupling agents can be added to the gelled network to improve adhesion to the emulsion layer thereon (eg,
European Patent No. 301,827; US Patent No. 5,2
04,219), and at the same time, optionally, alkali metal orthosilicates can be added to minimize conductivity loss when they are overcoated with a gelatin-containing layer (US Pat. No. 5,236,818). ). Also, colloidal metal oxides (eg, antimony pentoxide,
It has been pointed out that a coating containing alumina, tin oxide, indium oxide) and colloidal silica together with an organopolysiloxane binder not only improves abrasion resistance but also provides an antistatic function (US Pat. Nos. 4,442,168 and 4,571,365
issue).

[0006] Antistatic schemes using electronic conductors have also been disclosed. The observed electronic conductivity is not dependent on the relative humidity and is only slightly affected by the ambient temperature, since the conductivity mainly depends on the mobility of the electrons rather than the mobility of the ions. . Antistatic layers containing conjugated polymers, conductive carbon particles or semiconductive inorganic particles are described.

[0007] Trevoy (US Pat. No. 3,245,833)
No.) is 0.1% in the insulating film-forming binder.
It teaches the preparation of conductive coatings containing semiconducting silver iodide or copper iodide dispersed as particles of less than μm and having a surface resistivity of 10 ² to 10 ¹¹ ohms / square. The conductivity of these coatings is substantially independent of relative humidity. The coating is also relatively clear and sufficiently transparent to be used as an antistatic coating for photographic films. However, if a coating containing copper iodide or silver iodide was used as a subbing layer on the same plane as the film-based emulsion, during processing the semiconductor salts would migrate into the silver halide emulsion layer. Trev said that it is necessary to overcoat the conductive layer with a dielectric water impervious barrier layer to prevent
oy discovered (U.S. Pat. No. 3,428,451). Without the barrier layer, the semiconductor salt may interact with and adversely affect the silver halide layer, resulting in fog formation and reduced emulsion sensitivity. Also, without a barrier, the semiconductor salt is solubilized by the processing solution, resulting in a loss of antistatic function.

Another semiconductor material is disclosed by Nakagiri and Inayama (US Pat. No. 4,078,935) as being useful for antistatic layers for photography. A transparent, binder-free, electrically semiconductive metal oxide thin film was formed by oxidation of the thin metal film deposited on the film base. Suitable transition metals include titanium, zirconium, vanadium and niobium. The microstructure of the thin metal oxide film is non-uniform and discontinuous, and its properties are substantially "particulate""islan".
it has been found that those having a d) "structure. The surface resistivity of such semiconductive metal oxide thin film is not affected by the relative humidity, the in the range of 10 ⁵ to 10 ⁹ ohms / parallel However, metal oxide thin films have been reported to be cumbersome and expensive to use throughout the processes used to produce these thin films, and have low abrasion resistance for these thin films, as well as their low wear resistance. It is unsuitable for photographic applications due to poor adhesion of the thin film to the base.

A very effective antistatic layer containing an "amorphous" semiconductor metal oxide is disclosed in Guestaux (US Pat.
203,769). The antistatic layer is prepared by applying an aqueous solution containing a colloidal gel of vanadium pentoxide on a film base. The colloidal vanadium pentoxide gel is a typically entangled, high aspect ratio, flat ribbon having a width of 50 to 50 mm.
100Å, thickness 10Å, length 1,000-10,000
Å These ribbons stack flat in a direction perpendicular to the surface when the gel is applied on the film base. As a result, the electrical conductivity of the thin film of vanadium pentoxide gel (1Ω ⁻¹ cm ⁻¹ ) is typically less than that observed for films of the same thickness containing crystalline vanadium pentoxide particles. 3 orders larger. Furthermore, even if the application amount of vanadium pentoxide is extremely low, a low surface resistivity can be obtained. This results in low optical absorption and scattering losses. This thin film also has high adhesion to a properly prepared film base. However, vanadium pentoxide is soluble at high pH and must be overcoated with a non-permeable, hydrophobic barrier layer to make it processable. When used with a conductive subbing layer, a hydrophilic layer must be applied to the barrier layer to increase adhesion to the emulsion layer (Anderson et al., US Pat.
6,451).

The conductive fine particles of a crystalline metal oxide dispersed using a polymer binder are used for forming various images.
It has been used to prepare optically transparent, humidity insensitive antistatic layers. Various metal oxides-for example, Zn
O, TiO ₂ , ZrO ₂ , SoO ₂ , Al ₂ O ₃ , In
₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₃ and V
When ₂ O ₅ as the antistatic agent in the photographic element, or is useful as a conductive agent electrostatographic elements in, U.S. Patent No. 4,
Nos. 275,103, 4,394,441, 4,4
No. 16,963, No. 4,418,141, No. 4,43
No. 1,764, No. 4,495,276, No. 4,57
Nos. 1,361, 4,999,276 and 5,1
No. 22,445. However, many of these oxides do not provide acceptable performance characteristics in the environment they require. Preferred metal oxides are antimony-doped tin oxide, aluminum-doped zinc oxide, and niobium-doped titanium oxide. The surface resistivity, the antistatic layers containing the preferred metal oxides 10 ⁶ to 10
It is reported to be in the range of ⁹ Ω / square. In order to obtain high electrical conductivity, a relatively large amount (0.1 to 10 g /
m ² ) of the metal oxide must be contained in the antistatic layer. As a result, optical transparency decreases for thick antistatic coatings. Preferred refractive index of metal oxide (>
2.0), light scattering (clouding) by the antistatic layer
These metal oxides are ultrafine (<
0.1 μm) It is necessary to disperse the particles.

Electronically conductive ceramic particles: for example, T
An antistatic layer containing iN, NbB ₂ , TiC, LaB ₆ or MoB dispersed in a binder, for example, a water-soluble polymer or a solvent-soluble resin is disclosed in JP-A-4-5.
No. 5492 (published Feb. 24, 1992). Fibrous conductive powders containing antimony-doped tin oxide coated on non-conductive potassium titanate whiskers have been used to produce conductive layers for photography and electrophotography. Such materials are disclosed in U.S. Patent Nos. 4,845,369 and 5,116,666. The reported layers containing these conductive whiskers dispersed in a binder improve conductivity at lower volume concentrations than other conductive microparticles as a result of their higher aspect ratio. However, the resulting advantages that require low volume percentages are offset by the fact that the size of these materials is relatively large (10-20 μm in length). Such a large size results in increased light scattering and haze of the coating.

The use of high volume percent of conductive particles in the electronically conductive coating to achieve effective antistatic performance results in reduced transparency due to scattering and easy cracking, as well as in the support material. A brittle layer with poor adhesion may be formed. Therefore, it is non-brittle and adhesive,
Obviously, it is extremely difficult to obtain a highly transparent colorless electronically conductive coating film which has humidity-independent and process-resisting antistatic properties.

The requirements for the antistatic layer in silver halide photographic films are particularly stringent due to severe optical requirements. Other types of imaging elements, such as photographic paper and thermal imaging elements, also often require the use of an antistatic layer, but generally speaking the requirements of these imaging elements are Less severe. Electrically conductive layers are also commonly used in imaging elements for purposes other than antistatic. Thus, for example, in electrostatography, it is known to use an imaging element comprising a support, an electrically conductive layer acting as an electrode, and a photoconductive layer acting as an image forming layer. Electrically conductive agents utilized as antistatic agents in silver halide photographic imaging elements are often useful in electrode layers of electrostatographic imaging elements.

As mentioned above, because the prior art on electrically conductive layers in imaging elements is extensive, it has been proposed to use a very large number of different materials as electrical conductive agents. However, it is useful for a variety of imaging elements, can be manufactured at a reasonable cost, is resistant to the effects of humidity changes, is durable, abrasion resistant, and is effective at low coating weights And can be used with transparent imaging elements, does not adversely affect sensitometry or photographic effects, and is typically used to process solutions that the imaging elements typically contact, for example, silver halide photographic films. There remains a serious need in the art for improved electrically conductive layers that are substantially insoluble in the aqueous alkaline developer used.

[0015]

The needs of imaging elements, especially silver halide photographic films, but also a wide range of other imaging elements, are more effectively met than conventional ones. It is an object of the present application to provide an improved electrically conductive layer.

[0016]

According to the present invention, an imaging element for use in an imaging method comprises a support, an imaging layer, and a transparent electrically conductive layer containing polyaniline styrene sulfonic acid. Become. In a preferred embodiment of the present invention, the transparent electrically conductive layer comprises polyaniline styrene sulfonic acid dispersed in a film forming binder.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The imaging elements of this invention can be of many different types depending on the particular use for which they are intended. Such elements include, for example,
Examples include photographic imaging elements, electrostatographic imaging elements, photothermographic imaging elements, migration imaging elements, electronic thermographic imaging elements, dielectric recording imaging elements, and thermal dye transfer imaging elements.

Photographic elements to which the antistatic layer of the present invention can be applied can vary widely in structure and composition. For example, they can vary widely with respect to the type of support, the number and composition of the imaging layers, and the type of auxiliary layers included in the element. In particular, these photographic elements can be films, motion picture films, X-ray films, graphic arts films, photographic paper prints or microfish. They are black and white elements, color elements adapted for use in negative-positive processes,
Or it can be a color element adapted for use in a reversal process.

The photographic element can include any of a wide variety of supports. Typical supports include cellulose nitrate film, cellulose acetate film, poly (vinyl acetal) film, polystyrene film, poly (ethylene terephthalate) film, poly (ethylene naphthalate) film, polycarbonate film, glass, metal, paper, polymer Coated paper and the like can be mentioned. The imaging layer (s) of the element of the invention typically comprises a radiation-sensitive agent, such as silver halide, dispersed in a hydrophilic water-permeable colloid. Suitable hydrophilic vehicles include natural substances, e.g., proteins, e.g., gelatin, gelatin derivatives, cellulose derivatives, polysaccharides, e.g., dextran, gum arabic, etc., and synthetic polymeric substances, e.g., water-soluble polyvinyl compounds, e.g.,
Both poly (vinylpyrrolidone) and acrylamide polymer can be used. A particularly common imaging layer is a gelatin-silver halide emulsion layer.

In electrostatography, an image composed of an electrostatic potential pattern (also called an electrostatic latent image) is formed on an insulating surface by various methods. For example, an electrostatic latent image may be formed electrophotographically (ie, a uniform potential previously formed on the surface of an electrophotographic element that includes at least a photoconductive layer and an electrically conductive substrate may be imagewise imaged by a radiation induced discharge). ) Or by dielectric recording (i.e., by electrically forming a pattern of electrostatic potential directly on the surface of the dielectric material). Typically,
The electrostatic latent image is then developed by contacting it with an electrophotographic developer to form a toner image (if desired, the latent image can be transferred to another surface prior to development). The resulting toner image is then fixed in place on the surface by the application of heat and / or pressure or by other known methods (depending on the nature of the surface and the nature of the toner image), or thereafter similarly Can be transferred by known means to other surfaces that can be used.

In many electrostatographic imaging methods, the surface to which the toner image is ultimately transferred and fixed is the surface of a sheet of flat paper or the image is viewed by transmitted light (eg, projection by an overhead projector). Is the surface of the transparent film sheet element, if desired. In an electrostatographic element, the electrically conductive layer can be another layer, part of a support layer, or a support layer. There are many types of conductive layers known in the electrostatographic art, the most common of which are listed below: (a) Metallic laminates, such as aluminum-paper laminates. (B) Metal plates, for example, aluminum, copper, zinc, brass and the like. (C) Metal foil, for example, aluminum foil, zinc foil and the like. (D) evaporated metal layers, such as silver, aluminum, nickel and the like. (E) Semiconductors dispersed in a resin, such as poly (ethylene terephthalate), as described in U.S. Pat. No. 3,245,833. (F) Electrically conductive salts, for example, US Pat.
7,801 and 3,267,807.

The conductive layers (d), (e) and (f) can be transparent, and if a transparent element is required, for example, a process of exposing the element from behind rather than from the front or a transparent element It can be used when used as Heat-sensitive imaging elements are well known, including films and photographic paper for forming images by heat-sensitive. These elements include thermographic elements that form an image by imagewise heating the element. Such elements are, for example, Research
h Disclosure , June 1978, Item
No. 17029; U.S. Patent 3,457,075
No. 3,933,508; and U.S. Pat. No. 3,080,254.

The photothermographic element typically comprises an oxidation-reduction imaging combination and comprises an organic silver salt oxidizing agent, preferably a silver salt of a long chain fatty acid. Such organic silver salt oxidizing agents are resistant to darkening upon irradiation. Preferred organic silver salt oxidizing agents are silver salts of long chain fatty acids having 10 to 30 carbon atoms. Examples of useful organic silver salt oxidizing agents are silver behenate, silver stearate, silver oleate, silver laurate, silver hydroxystearate, silver caprate, silver myristate and silver palmitate. Combinations of organic silver salt oxidizing agents are also useful. Examples of useful silver salt oxidizing agents that are not silver salts of long chain fatty acids are, for example, silver benzoate and silver benzotriazole.

The photothermographic element also includes a light-sensitive component consisting essentially of photographic silver halide. In photothermographic materials, the latent image silver from silver barogenide is believed to act as a catalyst for the oxidation-reduction imaging combination during processing. The preferred concentration of photographic silver halide is, for example, 1 mole of silver behenate per mole of organic silver salt oxidizing agent in the photothermographic material.
It is in the range of 0.01 to 10 mol of photographic silver halide per mol. Other photosensitive silver salts are useful when desired in combination with photographic silver halide. Preferred photographic silver halides are silver chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide and mixtures of these silver halides.
Ultrafine grain photographic silver halide is particularly useful.

[0025] Migration imaging methods typically involve the placement of particles on a softenable medium. Typically, a medium that is solid and non-permeable at room temperature is softened by heat or solvent to allow image-like patterned particle migration. RW Gundlach, "Xeroprinting Master with Im
proved Contrast Potential ", Xerox Disclosure Jau
rnal , vol. 14, no. April / July / August, 1984, 2
The zero printing master element can be formed using migration imaging as disclosed on pages 05-06. In this method, a single layer of photosensitive particles is disposed on the surface of a layer of a polymeric material in contact with a conductive layer. After charging, the element is imagewise exposed to soften the polymeric material and then cause movement of the particles where such softening occurred (ie, image area). When the element is subsequently charged and exposed, the image areas (but not the non-image areas) can be charged, developed and transferred to paper.

US Pat. No. 4,536,457 to Tam;
Another type of migration imaging technique disclosed in U.S. Pat. No. 4,536,458 to Ng and U.S. Pat. No. 4,883,731 to Tam et al. Utilizing a solid migration imaging element with a layer of photosensitive marking material attached to or near the surface of the softenable layer. The member is electrically charged and then the element is exposed to imagewise pattern light to form a latent image by discharging selected portions of the marking material layer. The entire softenable layer is then made permeable by the addition of marking material, heat and / or solvent. The portions of the marking material that retain the differential residual charge upon exposure will then migrate into the softened layer by electrostatic forces.

The image-like pattern is formed by using the colorant particles in the solid imaging element to form a density difference between the image area and the non-image area (eg, agglomeration or coagulation of the particles). Is also good. Specifically, the colorant particles are uniformly dispersed and then selectively move to disperse them to varying degrees without changing the overall amount of particles on the element. Another migration imaging technique involves thermal development, which is described in RM Schaffert, Electrophotograply (Second
Edition, Focal Press, 1980), 44-4
7 and US Pat. No. 3,254,997. In this operation, an electrostatic image is transferred to a solid imaging element and colloidal pigment particles are dispersed in a heat-softenable resin film on a transparent conductive substrate. After softening the film with heat, the charged colloidal particles migrate to the oppositely charged image. As a result, the image area has a higher particle density, while the background area has a lower density.

The image forming method known as "laser toner melting" (dry electronic thermography method) is also of considerable commercial importance. In this method, a uniform dry powder toner deposit on a non-photosensitive film, photographic paper, or lithographic printing plate is imagewise exposed using a high power (0.2-0.5 W) laser diode. The toner particles on the substrate ("tacking"). Techniques such as electrophotographic "magnetic brush" techniques similar to those found in copiers are used to form a toner layer and remove non-image and other toner. A final blanket melting step may also be necessary depending on the exposure level.

Another example of an imaging element using an antistatic layer is a dye-receiving element used in a thermal dye transfer system. Thermal dye transfer devices for obtaining prints from images generated electronically from a color video camera are commonly used. According to one method of obtaining such a print, first, an electronic image is color-separated by a color filter. Next, each color separation image is converted into an electric signal. The signals are then manipulated to generate cyan, magenta, and yellow electrical signals, which are transmitted to a thermal plant. To obtain a print, a cyan, magenta or yellow dye-donor element is placed face-to-face with a dye-receiving element. The two elements are then inserted between the thermal print head and the platen roller. Heat is applied from the back of the dye-donor sheet using a line-type thermal printhead. The thermal printhead has a number of heating elements and is heated up sequentially in response to cyan, magenta and yellow signals. Thereafter, this process is repeated for the other two colors. Thus, a color hard copy corresponding to the original image viewed on the screen is obtained.
Details of this method and the apparatus for performing it are described in U.S. Pat. No. 4,621,271.

Another type of imaging method in which the imaging element can utilize an electrically conductive layer is to imagewise expose the dye-forming electrically activatable recording element to a current and thereby develop. Image formation followed by formation of a dye image, typically by thermal development means. Dye-forming electrically activatable recording elements and methods are well known and are disclosed in U.S. Patent Nos. 4,343,880 and 4,727,00.
No. 8 describes such patents.

In the imaging element of this invention, the imaging layer can be any of the types of imaging layers described above, as well as any other imaging layers known to be used in imaging elements. it can. All of the above image forming methods,
As well as many other forming methods, in common, as electrodes
Alternatively, an electrically conductive layer is used as an antistatic layer. The requirements for an electrically conductive layer useful in an imaging environment are extremely stringent, and the art is concerned with improved electrical conductive layers that combine physical, optical and chemical properties to meet the required requirements. Development has been going on for a long time.

As described above, the image forming element of the present invention comprises:
It contains at least one electrically conductive layer containing an effective amount of polyanilinestyrene sulfonic acid to impart antistatic properties to the electrically conductive layer. Useful binders for the polyaniline styrene sulfonic acid-containing antistatic layer include water-soluble polymers such as gelatin, gelatin derivatives, maleic anhydride copolymers; cellulose compounds such as
Carboxymethylcellulose, hydroxyethylcellulose, cellulose acetate butyrate, diacetylcellulose or triacetylcellulose; synthetic hydrophilic polymers such as polyvinyl alcohol, poly-N-vinylpyrrolidone, acrylic acid copolymers, polyacrylamides, their derivatives and partial hydrolysis products Products, vinyl polymers and copolymers, such as polyvinyl acetate and polyacrylate esters; derivatives of said polymers; and other synthetic resins. Other suitable binders are addition-type polymers and interpolymers, such as ethylenically unsaturated monomers, such as acrylates containing acrylic acid, methacrylates containing methacrylic acid, acrylamide and methacrylamide, itaconic acid and its half esters and Diester, styrene including substituted styrene, acrylonitrile and methacrylonitrile, vinyl acetate,
Aqueous emulsions of those made from vinyl ethers, vinyl and vinylidene halides, olefins, and aqueous dispersions of polyurethane or polyester ionomers are included.

Poly (aniline / polystyrene sulfonic acid) was prepared in situ by oxidative polymerization of aniline in an aqueous solution in the presence of poly (styrene sulfonic acid) using ammonium peroxodisulfate as the oxidizing agent. A typical production method is 0.99 g (1 mL, 1 mL).
0.6 mmoles) of aniline was added to 50 mL of an 8% by weight aqueous solution of polystyrene sulfonic acid. The solution was cooled and stirred in an ice bath. (NH ₄ ) in 50 mL of water
A solution of 1.208 g (5.3 mmoles) of ₂ S ₂ O ₈ was added dropwise over several hours. The reaction continued at room temperature overnight until complete. A dark green solution of the poly (aniline / polystyrene sulfonic acid) complex obtained by this method was used for 12,000 to 14,
SPECTRA / P with 000 molecular weight cutoff
OR dialysis membrane tubing was then dialyzed for about 8 hours using continuously supplemented distilled water. Coatings of poly (aniline / poly-styrene sulfonic acid) prepared in this manner are transparent for suitable photographic applications. A cloudy coating was obtained with the non-dialyzed comparative material.

Several conductive layers were formed with a coating combination of polyaniline-styrene sulfonic acid and various film-forming binders. Let the surface electrical resistivity be A
Trek Mode by STM Standard Method D257-78
l 150 surface resistivity meter (Trek Inc., Medina,
NY). To measure the resistivity to a typical photographic processing chemical, the conductive coating was immersed in a room temperature bath of a developer (C-41 developer, Eastman Kodak) for 15 seconds. These were then rinsed with deionized water for 5 seconds and then dried at room temperature. These samples were visually inspected for hue shifts, and then the surface resistivity was measured again.

The following examples were all coated on polyethylene terephthalate using an aqueous solution of a polyaniline-styrene sulfonic acid / binder system, wherein the support was acrylonitrile / chloride, as is well known in the art. It was primed with a vinylidene / acrylic acid terpolymer. Similar results are obtained using other undercoat layers or corona discharge treatment (CDT). In addition, other support materials can be selected, such as paper, resin-coated paper, cellulose triacetate, PEN, and the like. The coatings were prepared either by rolled wire rods or by X-hopper coating, but any commonly known coating method, including gravure, can be used. Surfactants, defoamers, leveling agents, matte particles, lubricants, crosslinking agents, etc. are added to such coatings if required by the application method or end use of such coatings. You may. These coatings were thoroughly dried at 100 ° C.

The following table shows information on the total dry coating amount of the conductive film and the ratio (% by weight) of the film containing polyaniline-styrenesulfonic acid of the present invention.

[0037]

[Table 1]

Polymer A: Terpolymer of acrylonitrile / vinylidene chloride / acrylic acid (15/78/7). Polymer B: n-butyl acrylate / glycidyl methacrylate (70/30) copolymer. Polymer C: copolymer of methyl methacrylate / hydroxyethyl methacrylate (90/10). Polymer D: commercially available sulfonated polyester, AQ55
(Eastman Chemicals). Polymer E: a commercially available styrene acrylic latex copolymer, BF (Goodrich Carboset GA 1931). Ludox SK: Commercially available colloidal silica (DuPon
t). Cymel 303: commercially available melamine-formaldehyde (crosslinking agent (American Cyanamid). EKL-4299: commercially available alicyclic epoxy resin (Union
Carbide). XL-29E: Commercial aliphatic carbodiimide, Union Ca
rbide Ucarlink.

The above examples are based on polyaniline-styrene-
Good results are obtained when used in combination with sulfonic acids,
It demonstrates that there is a wide range of polymeric and non-polymeric binders. Furthermore, it is intended to improve the resistivity to chemicals, and demonstrates various crosslinkers which are extremely useful in combination with such binders.

In order to improve abrasion and chemical resistance, the coatings may be made of materials known in the art, such as polyalkyl acrylates, methacrylates, polyurethanes, cellulose esters, styrene-
It may be overcoated with a contained polymer or the like. Such overcoats are preferred under the more severe conditions of actual photographic processing (high temperatures and long times).

As noted above, the use of polyaniline styrene sulfonic acid in the electrically conductive layer of the imaging element overcomes many of the problems previously encountered in the prior art. In particular, when polyaniline styrene sulfonic acid is used, it is possible to produce a transparent and electrically conductive layer having a processing persistence and at a reasonable cost. The aniline may be a substituted aniline. The electrically conductive layer is durable and abrasion resistant since it is resistant to the effects of humidity changes, thereby eliminating the need for an overcoat layer on the photographic image element.

[0042]

[Additional embodiment]

<Aspect 1> The image forming element according to claim 1, wherein the polyaniline styrene sulfonic acid is dispersed in a film-forming binder. <Aspect 2> The image-forming element according to aspect 1, wherein the film-forming binder is gelatin. <Embodiment 3> The image forming element according to embodiment 1, wherein the film-forming binder is a vinylidene chloride-based terpolymer latex. <Embodiment 4> The image forming element according to claim 1, wherein the polyaniline styrene sulfonic acid contains a substituted aniline. <Embodiment 5> A transparent coating composition for use in an image forming element, comprising a polyaniline styrene sulfonic acid dispersed in a film forming binder. <Embodiment 6> The transparent coating composition according to embodiment 5, wherein the film-forming binder is gelatin. <Embodiment 7> The transparent coating composition according to embodiment 5, wherein the film-forming binder is a vinylidene chloride-base terpolymer latex. <Embodiment 8> The transparent coating composition according to embodiment 5, wherein the polyaniline styrene sulfonic acid contains a substituted aniline.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Sylvia Alice Gardner New York, USA 14617, Rochester, Smugglers Lane 50

Claims (1)

[Claims] 1. An imaging element for use in an imaging method comprising a support, an imaging layer, and a transparent electrically conductive layer comprising polyaniline styrene sulfonic acid.