US3656949A

US3656949A - Method of producing an electrophotographic and electrographic recording member

Info

Publication number: US3656949A
Application number: US831879A
Authority: US
Inventors: Satoru Honjo; Nobuo Tsuji
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1968-06-10
Filing date: 1969-06-10
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18
Also published as: DE1929162B2; GB1259158A; DE1929162A1; BE734288A; DE1929162C3; FR2011512A1

Abstract

Improved process for producing electrophotographic/electrographic recording members wherein prior to coating the recording layer the substrate is subbed with an aqueous coating mixture prepared by dissolving a water soluble, film forming polymeric material in an aqueous solvent system and mixing therein an aqueous emulsion of a waterinsoluble polymeric material which is incompatible with the first polymeric material. The resulting subcoating forms a continuous film whereby the penetration of organic solvents are prevented into the substrate. Surface resistivity of the subbing layer does not exceed 1010 ohms/sq. at 40 percent relative humidity and room temperature.

Description

lJnited States Patent Honjo et a1.

[15] 3,656,949 [451 Apr. 10, 1972 [54] METHOD OF PRODUCING AN ELECTROPHOTOGRAPHIC AND ELECTROGRAPHIC RECORDING MEMBER [72] Inventors: Satoru Horrio; Nobuo Tsuji, both of Saitama, Japan [73] Assignee: Fuji Photo Film Co., Ltd., Kanagawa,

Japan [22] Filed: June 10, 1969 [21] Appl. No.: 831,879

[30] Foreign Application Priority Data June 10, 1968 Japan ..43/39800 [52] U.S.Cl. ..96/1.5,117/155 U, 117/148, 117/138.8, 117/218 [5 1 Int. Cl. ..G03g 5/00 [58] FieldofSearch ..96/1.5; 117/155 U; 162/10, 162/72 [56] References Cited UNITED STATES PATENTS 2,315,675 4/1943 Trommsdorff... ..92/21 Primary Examiner-George F. Lesmes Assistant ExdminerM. B. Wittenberg Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT Improved process for producing electrophotographic/electrographic recording members wherein prior to coating the recording layer the substrate is subbed with an aqueous coating mixture prepared by dissolving a water soluble, film forming polymeric material in an aqueous solvent system and mixing therein an aqueous emulsion of a water-insoluble polymer ic material which is incompatible with the first polymeric material. The resulting subcoating forms a continuous film whereby the penetration of organic solvents are prevented into the substrate. Surface resistivity of the subbing layer does not exceed 10 ohms/sq. at 40 percent relative humidity and room temperature.

17 Claims, 2 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of producing an electrophotographic light-sensitive or electrographic recording member.

2. Description of the Prior Art An electrophotographic light-sensitive sheet generally comprises a paper substrate, a photoconductive recording layer comprising an intimate mixture of an inorganic photoconductive powder or an organic photoconductor and an insulating resinous binder. A subbing layer also ordinarily exists between the substrate and the recording layer. The most important roles of the subbing layer are: 1 to prevent impregnation of a coating mixture into the porous structure of the paper substrate during coating procedure; and (2) to minimize the resistivity change of the substrate by ambient humidity, as well as to lower the surface resistivity of the substrate. It becomes especially important to prevent penetration of a coating mixture in the case where an organic solvent coating is employed for recording layer formation. This is less significant when an aqueous coating is used.

F ilm-forming materials for use as the subbing layer must, of course, be insoluble in, or not be attacked by, the solvent used for recording layer formation.

The second role of the subbing layer is quite important to produce an electrophotographic print of high quality, especially one of continuous tone. Since the electrical conductivity of paper depends on the moisture content thereof, it will often decrease to an extremely low value when the sheet is kept in equilibrium with a dried ambient atmosphere. While a highly resistive substrate makes it impossible to realize a uniform charge distribution throughout the whole area of the surface recording layer by corona charging, a uniform charging with a high surface charge density can easily be accomplished with a conductive sub coating. Such a uniform charge distribution is essential to produce a toner image of high saturation density in a short development time.

In the past, sub coatings were usually made from hydrophilic film-forming polymeric materials such as polyvinyl alcohol, polyacrylic acids, alkali metal polyacrylates, copolymers including maleic anhydride or maleic acid, or metal salts thereof. Such sub coatings suffered a marked decrease of conductivity under low humidity conditions, and even addition of hygroscopic inorganic salts could not solve this problem.

More recently, an improvement was made by introducing, as a sub coating material, quarternary ammonium polymeric materials such as are described in U.S. Pat. Nos. 3,011,918, 3,264,137 and 3,288,770. The present inventors succeeded in preparing an improved sub coating having a sufficiently high conductivity over a wide ambient humidity range by using metal salts of polyvinylbenzene sulfonic acid.

These PVB acid materials have proved to exhibit almost ideal characteristics as a conductive sub coating for an electrophotographic or electrographic recording member, show ing a surface resistivity around to 10 ohms/square (surface resistivity between two parallel electrodes having the same length as the spacing therebetween), even under a dried atmosphere of 30 to 40 percent relative humidity near room temperature, when coated on a paper to several microns thickness on dry base.

Another difliculty, however, arises with these polymers. Since they are strongly polar in nature, having a tendency to ionize with the existence of moisture (which is just the origin of their high conductivity), they are readily soluble only in water, and not in many organic solvents, which sometimes results in a poor adhesion between an insulating coating superposed thereon by the use of an organic solvent.

To improve such poor adhesion, one may further introduce an intermediate layer between the sub coating and the surface recording layer, which, however, creates a source of potential product deterioration, and at the same time, increases the cost of production.

Similar situations exist in the case of the production of an electrographic recording paper.

SUMMARY OF THE INVENTION The present invention involves an improved process for producing electrophotographic or electrographic recording members wherein a coating mixture containing organic solvents is applied on a non-metallic substrate to form the recording layer. The improvement comprises subbing the nonmetallic substrate, prior to the recording layer coating, with an aqueous coating mixture which has been prepared by dissolving a first, water-soluble, film-forming polymeric material in an aqueous solvent system, also being mixed therein is an aqueous emulsion of a second, water-insoluble polymeric material, which is incompatible with the first polymeric material. The resulting sub coating preferably has a dried thickness of from 0.5 10 microns. The sub coating forms a continuous film which prevents the penetration of organic solvents into the substrate. Further, the surface resistivity of the sub coating must not exceed 10 ohms/square at 40 percent relative humidity and room temperature.

Accordingly, one object of the present invention is to provide a method of producing electrophotographic or electrographic recording members which overcomes the heretofore described drawbacks.

A further'object is to provide such recording materials of an improved structure, which are possessed of stable electrical properties over a wide ambient humidity range, as well as with an improved adhesive property between the recording layer and the substrate.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are cross-sectional schematic views of recording members produced in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present method of producing electrophotographic or electrographic recording members comprises applying, on a non-metallic substrate, a coating mixture containing organic solvents to form a recording layer, but prior to the coating of the recording layer, involves subbing the substrate with an aqueous coating mixture which is prepared by dissolving a first, water soluble, film-forming polymeric material in an aqueous solvent system, and then adding an aqueous emulsion of a second, water-insoluble polymeric material, which is incompatible with the first polymeric material, in such a manner that the resulting sub coating has a dried thickness of from 0.5 to 10 microns. A continuous film is formed so as to prevent the penetration of organic solvents into the substrate, and to insure that the surface resistivity does not exceed 10 ohms/square at 40 percent relative humidity near room temperature.

An important improvement brought about by the present invention is due to the improved structure of the sub coating which has a very low surface resistivity, as well as a high affinity for the many hydrophobic or oleophilic insulating layers which can be coated thereon. The sub coating of the present invention is characterized by comprising a continuous conductive matrix phase and an oleophilic, minutely dispersed phase of water-insoluble emulsion particles.

Our experiments have favorably shown that the addition of an oleophilic ingredient in a minutely dispersed form into a water-soluble, conductive polymer does not substantially increase the resistivity of the resulting coating. This may be due to the existence of the continuous matrix of the conductive polymer. Not only have surface resistivity measurements of the sub coating, but also print tests have shown that the quality of the image is not affected at all by the incorporation of oleophilic particles into the sub coating, provided that the concentration of the particles in the sub coating does not exceed a certain limit. For example, incorporation of highly insulating polymeric particles having a specific resistance as high as 10" ohms-cm does not remarkably increase the surface resistance of the resulting coating, which may seem rather curious, but apparently this preferable result is due to the continuous phase comprising a conductive polymeric material, and also to the very fine particle size of the dispersed material.

Suitable polymeric materials for forming the continuous phase includes polymers comprising monomers containing the quarternary ammonium group, such as are described in the US. Pat. Nos. 3,011,918, 3,264,137 and 3,288,770. Watersoluble resins compatible with these may be incorporated therein, though they are less conductive than these cationic polymers. One example of the commercially available quarternary ammonium polymers is Calgon Conductive Polymer 261" from Calgon Corporation, in Pittsburgh, Pennsylvania, U. S. A. Electrical properties of sub coatings comprising this polymer and many other polymers compatible therewith are shown in detail on p. 26 to p. 31 of Tappi Vol. 50, No. 1 (1967). Such mixed coatings are also employed for the continuous phase in the present invention, provided that the resulting coatings containing dispersed particles exhibit a surface resistance not higher than 10 ohms/square at 40 percent relative humidity near room temperature.

In addition to the above-mentioned cationic polymers, alkali metal salts of polyvinyl benzene sulfonic acid, or of sulfonated polystyrenes are also used for the formation of the continuous phase.

The continuous phase may also contain polyhydric alcohols compatible with these conductive polymers such as glycerol, pentaeythritol pentaerthritol, sorbitol, ethylene glycol, triethylene glycol and other liquid plasticizers such as polyoxyethylene glycol. Those plasticizers, however, which destroy or deteriorate the colloidal stability of the second polymer must be excluded.

Sub coatings of the present invention must contain a finely dispersed polymeric material in the conductive continuous phase; polymers comprising this dispersed phase should be insoluble in water and be incompatible with the components comprising the continuous phase so as to exist in the form of fine particles dispersed in the resulting coating, as well as in the coating mixture. Accordingly the colloidal polymer particles should not agglomerate or flocculate in the presence of the first polymer of the matrix phase. Polymer emulsions resulting from emulsion polymerization are most suitable for the present object, including aqueous emulsions of polyvinyl acetate, polybutyl methacrylate, polyethyl acrylate, polybutyl acrylate, polyoctyl methacrylate, styrene/ butadiene copolymers, butadiene/methyl methacrylate copolymers, butadiene/acrylonitrile copolymers, etc. Emulsions containing polymers synthesized by condensation polymerization such as alkyd resins may also be used for the present invention. The aqueous emulsion of alkyd resin is not prepared by emulsion polymerization, but by emulsification of an organic solution thereof. These aqueous emulsions may be added to aqueous solutions of water-soluble polymeric materials.

Among the many useful polymer emulsions, those which contain non-ionic or anionic surfactants are preferable for use with sheet materials for use in liquid development, since many cationic surfactants are more or less soluble in many nonpolar organic solvents suitable for use as the carrier liquid of a liquid developer, and will thereby lower the volume resistance of the carrier liquid. To test the aptitude of a polymer emulsion, one may prepare a sheet coated with the emulsion, which, after drying of the coating, is immersed in a purified carrier liquid to be tested for a sufficiently long period (comparable to liquid development conditions). The resistivity change of the liquid before and after immersion is measured. When the resistivity after immersion is not lower than 10 ohm-cm, the emulsion can be judged suitable for the sheet for use in liquid development.

As long as the component of discontinuous phase did not occupy more than 60 percent by .weight of the total weight of the resulting coating, the increase of the surface resistivity of the dried coating proved quite small.

The practical structures of the recording materials made in accordance with the present invention are illustrated in FIGS. 1 and 2.

In FIG. 1, 1 is a substrate comprising, for example, paper, woven fabrics, non-woven fabrics of a fine structure, plastic films such as cellulose acetate, polycarbonates, polyethylene terephthalate, polystyrene, etc., or a wood board. A sub coating 2 comprises a continuous phase of low resistance, and a discontinuous dispersed phase. An electrophotographic lightsensitive layer, or an insulating electrographic recording layer 3, is coated thereon by the use of an organic solvent. The electrophotographic recording layer may be of any type known in the art, comprising, for example, intimate mixtures of a resinous binder and inorganic photoconductive powders such as zinc oxide, cadmium sulfide, or selenium, an organic photoconductor, vacuum deposited selenium, etc. Electrographic recording layers may comprise solely insulating resinous materials or may be pigmented.

A back coating 4, which is not always necessary, may sometimes be provided to prevent curl of the resulting sheet material, such as when the substrate is of a small thickness and apt to curl due to the front coating. Such balancing coatings can be made of materials capable of forming a water-resistant film such as casein, gelatin, carboxymethylcellulose, polyvinyl alcohol, etc.

FIG. 2 illustrates another embodiment of the present invention, in which a thin layer of high insulating property 5 is provided between the layers 2 and 3. Though a rather thick layer is shown in the drawing for schematic representation, a very thin layer is satisfactory, generally comprising a transparent thermosetting insulating resinous material. This layer acts to prevent carrier injection from the low resistive layer 2 into the recording layer 3, playing a very important role when an image exposure is carried out from the back side of the material.

Suitable materials for such coating include epoxide or alkyd resins, which are preferably cured. The thickness may be about 0.5 to 5 microns.

Several practical examples now follow which are related to the production of an electrophotographic recording member, which is essentially the same as for electrographic members. The preparation of the latter is, in fact, far simpler than the former from the technical point of view.

Important features imparted to recording members by the use of the present invention are as follows:

1. Tendency to curl of the recording member is decreased by virtue of the reduced moisture absorbing property of the sub coating.

2. Water-resistance of the sub coating improves.

3. Adhesion between the sub coating and the recording layer improved.

4. Especially when a substrate having a smooth surface is used, such as a smooth plastic film, blocking of the sub coated substrate with the back of the sheet is prevented during the manufacture of the recording member.

5. In case it is technically difficult to add a plasticizer such as liquid polyhydricalcohol to the sub coating liquid, a subbing layer possessed of substantially the same properties but without plasticizer can be obtained by using a sub coating liquid prepared by adding the emulsion of soft polymer to a water-soluble polymer.

EXAMPLE 1 On the coated side of baryta coated paper was coated a sub coating having each of the following compositions listed on the middle column in the Table l, to give a dried thickness of about 3 microns. The coated sheets were kept for 40 hours in an atmosphere at 20 C. and 40 percent relative humidity.

Then the surface resistance of the sheets was measured. The

results were shown in the right column. Coating of the subbing layer was carried out in the following manner.

To a certain volume of a percent aqueous solution of the potassium salt of polyvinylbenzene sulfonic acid (PVBS- K),*(*Contained an anionic activator) there was added various volumes of an aqueous emulsion of polybutyl methracrylate*"( Molecular weight 120,000) (non-volatiles content percent). To the resulting mixture was added glycerol. The obtained coating liquid was coated on the baryta coated side of the baryta paper by means of a wire wound coating rod.

The untreated baryta layer exhibited a surface resistivity of the order of 10 ohms/square under the same ambient conditions.

Each of the above sub coatings exhibits a sufficiently low surface resistance. On each of these samples there was coated a photoconductive recording layer comprising photoconductive zinc oxide and an alkyd resin binder utilizing toluol as the coating solvent. The recording sheet, after being completely dark-adapted, was subjected to electrophotographic procedures under the same ambient conditions as used for the surface resistance measurement. Development was carried out by a liquid developer containing extremely fine toner particles, which converted an electrostatic latent image corresponding to an optical step wedge made from a silver halide film.

Each sheet accepted charges with high uniformity, and gave a developed image free from mottle with a uniform density.

EXAMPLE 2 anionic activator) A similarly good result was obtained.

EXAMPLE 3 This example differs from the first only in that an aqueous emulsion of polyvinyl acetate replaced the polybutyl methacrylate. Results were similarly good.

EXAMPLE 4 On a transparent sheet of cellulose triacetate film, having a thickness of 50 microns and bearing on one surface a gelatin containing sub coating suitable for accepting silver halide/gelatin emulsions, there was coated a cationic polymer (purchased from the Calgon Corp. in U. S. A.) which is sold under the trade name of Calgon Conductive Polymer 261." This layer, though possessing a very low surface resistivity over a wide range of ambient humidity, has a tendency to become sticky or adhesive under relatively high humidity conditions. When the same aqueous emulsion of polybutyl methacrylate*( *Nonvolatile content 20 percent; polymerized by cationic activator) as was used in the first example was added to the Calgon polymer in such a manner that the emulsion particles occupy 50 percent by weight of the resulting coating, this tendency was effectively reduced.

EXAMPLE 5 Onto a transparent sheet of polyethylene terephthalate film, having a thickness of 100 microns and bearing on one surface a sub coating comprising a linear polyester resin purchased from Goodyear Tire and Rubber Co., sold under the trade name Vitel PE 200, was coated a mixture comprising:

60 parts by weight of the potassium salt of polyvinylbenzene sulfonic acid,

parts by weight of an aqueous emulsion of butadiene methylmethacrylate copolymer*(*POLYLAC ML 501; TOYOKOATSU COMPANY, LTD.) (non-volatiles content 50 percent) and 860 parts by weight of water to give a dried thickness of about 2 microns. This coating exhibited a surface resistance of 7 X 10 ohms square, at 40 percent R.H., 25 C. On this coated surface, there was coated the same ZnO coating mixture as was used in Example 1. The resulting electrophotographic sheet exhibited excellent properties.

EXAMPLE 6 Onto cellulose acetate film of 50 micron thickness there was provided the sub coating used for sample B in the first example. Then, a 2 micron thick insulating coating comprising an epoxide resin made from the condensation between epichlorohydrin and bisphenol A (purchased from Shell Chemical Co.), which is sold under the trade name number- Epikote 828, and a copolymer of maleic anhydride and acid styrene (mixing ratio 60:40) was coated in the form of an acetone solution. The coated film was kept at 80 C. to cure this insulating coating.

Onto this coating there was finally superposed a dye sensitized zinc oxide layer which, after drying and dark-adaptation, accepted a sufficiently high positive potential by positive corona discharge. A similarly prepared film without the cured Epikote coating accepted only a negative potential. The positive potential, once accepted, decayed slowly in darkness. The positively charged film was subjected to image exposure through the acetate film substrate and then to development of the zinc oxide layer, which produced a clear and definite toner image.

A contact reflection exposure of this material was also carried out successfully; another sheet with an uniform positive electrostatic charge on the zinc oxide coating was superposed in close contact with opaque printed matter, and exposed to uniform irradiation from the zinc oxide coating side. Upon disassembling these sheets, development was carried out. A clear reproduction of the printed image resulted.

EXAMPLE 6 Onto one surface of document paper having a thickness of 60 microns there was coated the resistivity layer of sample D in Example 1 to a dried thickness of 2 microns. After drying of this coating, a toluol solution of polybutyl methacrylate was coated to yield an insulating layer of 6 microns on the dry base.

The dried insulating layer was brought into contact with pattern electrodes connected to a high voltage supply, and then developed. A clear and distinct toner image resulted.

The above material basically sets forth the present invention. The following material is offered to set forth several of the most preferred ranges, etc. utilized in the present invention, and to also describe more specifically some of the materials utilized in the specific examples, although the specificity provided is not essential to an understanding of the invention.

Firstly, in the final coating, the ratio of water-soluble polymer to water insoluble polymer is preferably within the range 40:60 :10, most preferably 50:50 to 75:25. in an aqueous coating mixture, the non-volatile components concentration (the above-mentioned polymers) is most preferably within the range 5-40 percent by weight. Further, the emulsion particles most preferably have a range within the size 0.5-0.5 microns.

Further, the polymers used can be characterized by their specific surface resistance. For the water-soluble polymer, this is less than 10 ohm/square (at 40 percent relative humidity and at room temperature), and the water insoluble polymer preferably illustrates a specific surface resistance greater than 10 ohm/square (40 percent R.H.; room temperature). The molecular weight of the polymers used can vary anywhere from several ten-thousands to several hundred-thousands. This is not critical, as long as the other parameters heretofore set forth are met.

Further, with respect to the water-soluble-water-insoluble polymers utilized, cationic aqueous polymers and emulsion particles having a cationic charge can be utilized. Further, anionic aqueous polymers and emulsion polymers having an anionic charge are useful in this invention.

We claim:

1. In a method of producing an electrophotographic or electrographic recording member wherein an organic solvent containing coating mixture is coated, onto a nommetallic substrate, to yield a recording layer, the improvement which comprises:

prior to coating said recording layer on said substrate forming a subbing layer by coating the substrate with an aqueous subbing mixture which comprises a water-soluble, film-forming material in an aqueous solvent system, and an aqueous emulsion of a water-insoluble polymeric material incompatible with said water-soluble material, said subbing layer forming a continuous film whereby penetration of organic solvent into said substrate is prevented, said subbing layer illustrating a surface resistivity of no greater than 10 ohms/square at 40 percent relative humidity and at about room temperature,

said water-soluble film-forming material being an alkali metal salt of polyvinylbenzene sulfonic acid, and

said water-insoluble polymeric material being a member selected from the group consisting of polyvinyl acetate, polybutyl methacrylate and a copolymer of butadiene and methyl methacrylate.

2. The method of claim 1 wherein said aqueous subbing mixture is prepared by dissolving said water-soluble, filmforming polymeric material in an aqueous solvent system to form a solution, and by mixing said solution with an aqueous emulsion of said water-insoluble polymeric material which is incompatible with said water-soluble, film-forming polymeric material.

3. The method of claim 1 wherein said subbing layer is coated in an amount sufficient to have a dried thickness within the range of from about 0.5 to microns.

4. The method of 'claim 1 wherein said subbing layer is dried prior to the application of said organic solvent containing coating mixture to yield said recording layer, whereby said continuous film of said subbing layer is formed.

5. The method of claim 1 wherein said water-soluble, filmforming material forms the continuous phase of said aqueous subbing mixture, and said water-insoluble polymeric material forms the discontinuous phase of said aqueous subbing mixture.

6. The method of claim 1 wherein said water-soluble, filmforming material is a cationic polymer.

7. The method of claim 1 wherein said aqueous subbing mixture further contains a polyhydric alcohol compatible with said water-soluble, film-forming material.

8. The method of claim 1 wherein the ratio of said watersoluble, film-forming material to water-insoluble polymeric material is in a range of from 40:60-90:10.

9. The method of claim 8 wherein said range is from 50:50 to 75:25.

10. The method of claim 1 wherein said emulsion particles have a size of0.5 microns.

11. The method of claim 7 wherein said polyhydric alcohol is a member selected from the group consisting of glycerol, pentaerithritol, sorbitol, ethylene glycol, triethylene glycol, and polyoxyethylene glycol.

12. In a method of producing an electrophotographic or electrographic recording member wherein an organic solvent containing coating mixture is coated, onto a non-metallic substrate, to yield a recording layer, the improvement which comprises:

said water-insoluble polymeric material being a member selected from the group consisting of polyethyl acrylate, polybutyl acrylate, polyoctyl methacrylate, styrene-butadiene-copolymers, and butadiene-acrylonitrile copolymers.

13. In a method of producing an electrophotographic or electrographic recording member wherein an organic solvent containing coating mixture is coated, onto a non-metallic substrate, to yield a recording layer, the improvement which comprises:

prior to coating said recording layer on said substrate forming a subbing layer by coating the substrate with an aqueous subbing mixture which comprises a water-soluble, film-forming material in an aqueous solvent system, and an aqueous emulsion of a water-insoluble polymeric material incompatible with water soluble material, said subbing layer forming a continuous film whereby penetration of organic solvent into said substrate is prevented, said subbing layer illustrating a surface resistivity of no greater than 10" ohms/square at 40 percent relative humidity and at about room temperature,

said water-soluble, film-forming material being sulfonated polystyrene, and

14. The recording member produced by the process of claim 1.

15. The recording member of claim 14 wherein said subbing layer is coated in an amount sufficient to have a dried thickness within the range of from about 0.5 to 10 microns.

16. The recording member of claim 14 wherein the ratio of said water-soluble, film-forming polymeric material to said water-insoluble polymeric material is within the range of from 40:6090: 10.

17. The recording member of claim 14 wherein said range is from 50:50 to 75:25.

Claims

2. The method of claim 1 wherein said aqueous subbing mixture is prepared by dissolving said water-soluble, film-forming polymeric material in an aqueous solvent system to form a solution, and by mixing said solution with an aqueous emulsion of said water-insoluble polymeric material which is incompatible with said water-soluble, film-forming polymeric material.
3. The method of claim 1 wherein said subbing layer is coated in an amount sufficient to have a dried thickness within the range of from about 0.5 to 10 microns.
4. The method of claim 1 wherein said subbing layer is dried prior to the application of said organic solvent containing coating mixture to yield said recording layer, whereby said continuous film of said subbing layer is formed.
5. The method of claim 1 wherein said water-soluble, film-forming material forms the continuous phase of said aqueous subbing mixture, and said water-insoluble polymeric material forms the discontinuous phase of said aqueous subbing mixture.
6. The method of claim 1 wherein said water-soluble, film-forming material is a cationic polymer.
7. The method of claim 1 wherein said aqueous subbing mixture further contains a polyhydric alcohol compatible with said water-soluble, film-forming material.
8. The method of claim 1 wherein the ratio of said water-soluble, film-forming material to water-insoluble polymeric material is in a range of from 40:60-90:10.
9. The method of claim 8 wherein said range is from 50:50 to 75: 25.
10. The method of claim 1 wherein said emulsion particles have a size of 0.5 microns.
11. The method of claim 7 wherein said polyhydric alcohol is a member selected from the group consisting of glycerol, pentaerithritol, sorbitol, ethylene glycol, triethylene glycol, and polyoxyethylene glycol.
12. In a method of producing an electrophotographic or electrographic recording member wherein an organic solvent containing coating mixture is coated, onto a non-metallic substrate, to yield a recording layer, the improvement which comprises: prior to coating said recording layer on said substrate forming a subbing layer by coating the substrate with an aqueous subbing mixture which comprises a water-soluble, film-forming material in an aqueous solvent system, and an aqueous emulsion of a water-insoluble polymeric material incompatible with said water-soluble material, said subbing layer forming a continuous film whereby penetration of organic solvent into said substrate is prevented, said subbing layer illustrating a surface resistivity of no greater than 1010 ohms/square at 40 percent relative humidity and at about room temperature, said water-soluble film-forming material being an alkali metal salt of polyvinylbenzene sulfonic acid, and said water-insoluble polymeric material being a member selected from the group consisting of polyethyl acrylate, polybutyl acrylate, polyoctyl methacrylate, styrene-butadiene-copolymers, and butadiene-acrylonitrile copolymers.
13. In a method of producing an electrophotographic or electrographic recording member wherein an organic solvent containing coating mixture is coated, onto a non-metallic substrate, to yield a recording layer, the improvement which comprises: Prior to coating said recording layer on said substrate forming a subbing layer by coating the substrate with an aqueous subbing mixture which comprises a water-soluble, film-forming material in an aqueous solvent system, and an aqueous emulsion of a water-insoluble polymeric material incompatible with water soluble material, said subbing layer forming a continuous film whereby penetration of organic solvent into said substrate is prevented, said subbing layer illustrating a surface resistivity of no greater than 1010 ohms/square at 40 percent relative humidity and at about room temperature, said water-soluble, film-forming material being sulfonated polystyrene, and said water-insoluble polymeric material being a member selected from the group consisting of polyvinyl acetate, polybutyl methacrylate and a copolymer of butadiene and methyl methacrylate.
14. The recording member produced by the process of claim 1.
15. The recording member of claim 14 wherein said subbing layer is coated in an amount sufficient to have a dried thickness within the range of from about 0.5 to 10 microns.
16. The recording member of claim 14 wherein the ratio of said water-soluble, film-forming polymeric material to said water-insoluble polymeric material is within the range of from 40:60-90:10.
17. The recording member of claim 14 wherein said range is from 50:50 to 75:25.