Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/10—Bases for charge-receiving or other layers
  • G03G5/105—Bases for charge-receiving or other layers comprising electroconductive macromolecular compounds
  • G03G5/107—Bases for charge-receiving or other layers comprising electroconductive macromolecular compounds the electroconductive macromolecular compounds being cationic
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F8/00—Chemical modification by after-treatment
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/76—Photosensitive materials characterised by the base or auxiliary layers
  • G03C1/85—Photosensitive materials characterised by the base or auxiliary layers characterised by antistatic additives or coatings
  • G03C1/89—Macromolecular substances therefor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors

Definitions

• 2095 mol percent of the units of the copolymer are derived from at least one cationic or anionic monomer carrying electroconductive groups, 80 mol percent of such units are derived from a monomer carrying reactive halogen atoms and 0-44 mo] percent of such units are derived from a monomer carrying an acidic group in free acid or salt form which is reactive with the halogen atoms of units of the second mentioned monomer, at least about 5 mol percent of the last mentioned monomeric units being present where the first mentioned monomeric units are unreactive with the halogen atoms of the second mentioned monomeric units.
• the invention relates to electroconductive layers for use in recording materials.
• Electroconductive products are used in all kinds of recording materials to dissipate electrostatic charges.
• the usual synthetic film supports have the property of being charged electrostatically, so that the charged films strongly attract the surrounding dust and thereby become soiled at their surface.
• discharge images may become visible in the light-sensitive layer upon development.
• Such an elecstostatic charging is caused by quickly moving the film support or light-sensitive photographic material during rolling or unrolling in the coating, cutting, or packing machines and by making the film run through the camera and the projector.
• the static charging can be decreased by coating the synthetic resin support with a conductive auxiliary layer.
• an electrostatic charge is imparted to paper or to other dielectric supports in a determined pattern.
• the support is conductive or must be coated with a conductive layer.
• a photoconductive layer stands in contact with an electroconductive layer or sheet, which serves for dissipating the electrostatic charges at the areas of the photoconductive layer undergoing an exposure to light rays.
• the conductive element serves to apply a voltage thereon, thus allowing the formation of the electrostatic charge pattern applied to the insulating top layer.
• Electroconductive layers for carrying off electrostatic charges may also be useful in recording elements wherein photosensitive semiconductor compounds are reversely ac- 3,708,289 Patented Jan. 2, 1973 tivated by electromagnetic radiation and wherein the activated patterns provide irreversible images by an oxidation-reduction chemical process.
• recording material is intended to include the type of materials used in all of the above described recording methods. In all these recording materials the surface resistivity of the electroconductive layer must not be higher than 10 ohm per sq. cm. at 15% of relative humidity.
• a sheet or webforming material of paper or synthetic polymers is provided, at least one side of which is coated with an electroconductive layer preferably having a surface resistivity lower than 10 ohm/sq. cm., said layer being composed mainly of a copolymer comprising:
• copolymer being initially water-soluble and capable upon heating to 180 C. of becoming a cross-linked, water-insoluble copolymer.
• Suitable units deriving from cationic monomers, which are responsible for the electro-conductivity of the copolymer are units comprising quaternary ammonium salt groups, salt groups derived from primary, secondary or tertiary amines or tertiary sulphonium salt groups.
• units comprising quaternary ammonium salt groups of tertiary sulphonium salt groups are for instance the units derived from:
• Examples of units comprising salt groups derived from amines are:
• units deriving from anionic monomers that are responsible for the electro-conductivity of the whole copolymer can be used units comprising carboxyl groups in their alkali metal or ammonium salt form and sulphonic acid or phosphonic acid groups.
• the latter two groups may occur in their free acid form as well as in their alkali metal or ammonium salt form.
• monomers comprising the above acid groups are acrylic acid, methacrylic acid maleic acid, itaconic acid, citraconic acid, vinylbenzoic acid, vinylsulphonic acid, styrene-sulphonic acid, 'y-sulphopropylacrylate, fi-sulphobutyl acrylate, and vinylphosphonic acid.
• the second class of randomly distributed units constituting the copolymer molecules is formed by units deriving from monomers carrying reactive halogen atoms, particularly chlorine and bromine atoms.
• Suitable monomers are those wherein a halogen atom is attached to a carbon,
• chloromethylacrylate or methacrylate u-chloroethylacrylate or methacrylate, fl-chloroethylacrylate or methacrylate, fl-bromoethylacrylate or methacrylate, 'y-chloro-fl-hydroxypropyl acrylate or methacrylate, vinyl bromoacetate,
• the copolymers may also comprise units of the third class, which carry groups that are reactive with the halogen atoms of the preceding class of monomers.
• alkali metal or ammonium salts of carboxylic acid groups, further sulphonic acid or phosphonic acid groups as Well as their alkali metal or ammonium salts.
• suitable monomers of the third class for use according to the invention are the alkali metal or ammonium salts of maleic acid, acrylic acid, methacrylic acid, vinylbenzoic acid, itaconic acid, crotonic acid, and citraconic acid.
• the reactivity of the halogen atom in some units of the second class is very high, e.g. in vinylbenzyl chloride.
• the copolymer comprises these reactive halogencontaining units it is no longer necessary to include units of the third class in the copolymer, since the sole presence of electroconductive units and of units containing halogen atoms with a very high reactivity suflices to yield cross-linked and thus insolubilized copolymers upon heating.
• the electroconductive units comprise anionic groups, which easily react with halogen atoms
• the third group of units in the copolymer can also be omitted. In all these cases the final copolymer only comprises units of the first and of the second class.
• electroconductive copolymers may comprise, in addition to the reactive halogen-containing units, electro-conductive units deriving from anionic and from cationic monomers. This is the case when for instance the 4 copolymers comprise units containing quaternary ammonium salt groups together with units containing carboxyl groups in their alkali metal or ammonium salt form.
• the electroconductive copolymers of the invention can be prepared by known copolymerisation techniques, starting from mixtures of different a,fi-ethylenically unsaturated monomers respectively comprising the groups needed in the final copolymers. Yet, it is not necessary to copolymerise three different monomers (in some cases two monomers as indicated above), which already comprise the desired groups. These groups can also be introduced in existing polymers or copolymers by kown reactions. For instance, the units comprising quaternary ammonium salt groups can be formed by quaternization of chloromethyl-styrene units, or of acryloyl or methacryloyl oxyalkyl chloride units.
• styrene units can be sulphonated to styrene sulphonic acid units, or acrylic acid units can be made to react with 1,3-propane sultone or 1,4-butane sultone, or acrylic acid units can be formed by partial saponification of B-chloroethyl acrylate.
• the copolymers of the invention are water-soluble as a result of the large number of anionic or cationic units, that are distributed randomly over the polymer chain. However, owing to the presence of units containing reactive halogen atoms and to units comprising groups that are reactive with these halogen atoms, cross-linking between adjacent molecule chains occurs upon heating, whereby the copolymer finally becomes insoluble.
• a layer of the copolymer applied to any support from aqueous or organic solution becomes completely resistant to water upon heating and accordingly remains undisturbed, e.g. when in an electrographic recording element the photoconductive layer is deposited on the electroconductive copolymer layer from an aqueous solution or dispersion. If the layer would not become insoluble in water, it would be partly dissolved and mixed with the photoconductive material, so that it would not be possible any longer to retain an electric charge in the photoconductive material.
• the insolubility in water after drying of the copolymer layer is also of great importance in the case of photographic silver halide recording materials. Indeed, the electroconductive layer cannot be dissolved away in the processing baths and its antistatic properties are preserved in the finished photographic film material. The surrounding dust does not deposit any longer on such processed film material.
• the coating After having applied a solution of the copolymer onto a support and having eliminated the solvent or solvents by known means, the coating is heated to 30-180 C. depending on the particular copolymer used so that crosslinking occurs between the copolymer molecules. As a result of this cross-linking reaction the copolymer layer becomes insoluble in water. Cross-linking is effected below the temperature, at which charring or damage to the support may take place. In general, the curing time may vary between 1 and 5 minutes. The material is passed through a curing oven heated to the curing temperature.
• the electroconductivity of the copolymers is proportional to the mole percent of cationic or anionic monomeric units conferring electroconductivity to the copolymers. It has been found that at least 20 mole percent, preferably at least 50 mole percent of these units must be present to allow the copolymers to be used as electroconductive polymeric material in any image-recording element.
• the electroconductivity of the copolymers is determined by measurement of their surface resistivity.
• a 10% by weight solution of the copolymer is applied therefor to a glass plate.
• the resulting layer is dried and conditioned at a specific relative humidity.
• the resistivity measurements are performed by means of a cell, both poles of which have a width of 0.5 cm. and are placed at a distance of 1 cm. from each other.
• the surface resistivity should not exceed certain limits, which themselves are influenced by the relative humidity degree. For instance, the surface resistivity at 15% of relative humidity must not be higher than 10 oh'm/ sq. cm., whereas at 70% of relative humidity the surface resistivity must certainly not be higher than 10 ohm/sq. cm.
• From 5 to 80 mole percent of units comprising reactive halogen atoms may be present in the copolymer and from to 44 mole percent may be formed by units comprising groups that are reactive with halogen atoms.
• the copolymer comprises but two kinds of monomeric units as set forth above, for instance anionic monomeric units and units comprising reactive halogen atoms
• the number of the electroconductive units may be much higher. It was very remarkable that the presence of only to of units containing halogen atoms already resulted in a sufiicient cross-linking upon heating of the copolymer molecules and insolubilisation of the copolymer layer. In this case the number of electroconductive units may amount to 95 mole percent, so that the electroconductivity of the copolymer increases accordingly.
• the copolymers of the invention are soluble in water, in organic solvents, or in mixtures of organic solvents and water, especially when the mole percent of electroconductive monomeric units is very high, thus making it possible to apply them as a coating composition to a support by spray, brush, roller, doctor blade, air brush, or wiping techniques.
• supports are paper, films of synthetic polymers such as films of cellulose acetate, polystyrene, polyesters or polycarbonates. If needed, the different supports may be provided previously with known subbing layers, whereon the electroconductive layer is coated afterwards.
• the electroconductive copolymers also impart electroconductivity, when a paper base used as support, is thoroughly soaked with a solution of the electroconductive polymeric material according to the invention. So, the electroconductive copolymers remain dispersed throughout the entire dry paper base. Electroconductivity may also be conferred to the paper base by adding a sufiicient quantity of copolymer solution to the papermaking pulp.
• an amount of dry copolymer varying between 0.5 and 5 g./sq. m. of support will in general be suflicient.
• care is to be taken also that about 4% by weight of copolymer be present with respect to the weight of dry solids of the paper support.
• the invention is not restricted to the use in electroconductive layers of copolymers only comprising the units as defined above. Indeed, when using styrene-sulphonic acid for the electroconductive units, there will practically always be present a certain number of styrene units. Further, whenever necessary, a small amount of other units may be present in the copolymer, e.g. plasticizing units such as alkyl acrylate units. In this case too a material is obtained, which is useful as electroconductive layer that is soluble in water, in organic solvents, or in mixtures of organic solvents and water, and which can be cross-linked and thus rendered insoluble by a simple heat treatment.
• composition of the electroconductive layer may also include stabilizing agents, plasticizers, dispersing agents, pigments, hydrophilic binders, e.g. gelatin, and hydrophobic binders, e.g. cellulose diacetate or cellulose triacetate. Due care must be taken to avoid precipitation of the copolymer and of said binder.
• the electroconductive layer of the invention is to be used as an antistatic layer in a photographic silver halide recording material
• the electroconductive layer is generally applied to the rear of the photographic film. It can, however, also be applied as an interlayer between the support and the light-sensitive emulsion layer or layers.
• the electroconductive layer is to be used in an electrophotograyhic recording material, a photoconductive coating is applied on top thereof.
• This coating is prepared by dispersing or dissolving the photoconductive substance or substances in an aqueous or organic solution of an insulating binder or in a solution of such insulating binder in a mixture of an organic solvent and water, and by applying the dispersion or solution in the form of a layer to the electroconductive surface. Even if the photoconductive layer is applied from aqueous solution or dispersion, there is no danger that the electroconductive polymeric material would wholly or partly dissolve.
• the electrophotographic recording element prepared with the electroconductive copolymer of the present invention is flexible and possesses very good mechanical strength. A very good adhesion exists between the paper support and the electroconductive layer.
• the present invention puts an end to the ditficulties in electrophotography, which hitherto have been described in the literature with respect to the precise composition of a separation layer between a paper soaked with salts or a paper web covered with the formerly known electroconductive copolymers and a photoconductive material applied from aqueous phase. Indeed, when using the electroconductive copolymers according to the invention in such a separation layer all the favourable characteristics of the present invention are utilized. Electrophotographic images are obtained, which only in respect of quality are dependent on the composition of the photoconductive layer and which are not disturbed anymore by unfavourable properties of formerly used electronconductive substances.
• PREPARATIONS (1) Copolymer of N-acryloyloxyethylpyridinium chloride, p-chloroethyl acrylate, and sodium acrylate
• A Poly-B-chloroethyl acrylate.In a reaction vessel equipped with a stirrer, a reflux condenser and a nitrogen inlet 134.5 g. of fi-chloroethyl acrylate are dissolved in benzene and filled up with benzene to 500 ml. To this solution 134.5 mg. of azo-bis-isobutyronitrile are added. The solution is then heated to C. while stirring and bubbling nitrogen through it.
• Poly-fl-chloroethyl acrylate is isolated from the solution by pouring the benzene solution in 3 l. of methanol. A sticky polymer residue is formed, which after rinsing with 1 l. of methanol is dissolved in acetone.
• the distillation apparatus is replaced by a reflux condenser and the reaction mass is heated further on an oil-bath at 100 C. while stirring. After 4 hours of reaction a partially quaternized polymer deposits. Then 50 ml. of ethanol are added so that the solution becomes homogeneously clear again. Two hours later the solution is again turbid and another 50 ml. of ethanol are added.
• a viscous opal solution is obtained, in which upon addition of 1 l. of dioxan a sticky polymer deposits.
• the resulting polymer is purified by dissolving in 500 ml. of methanol and precipitating in l. of dioxan. After filtration the polymer is dissolved in water whereupon the pH of the resulting solution is raised from 4.8 to 7.0 by means of sodium hydroxide. A clear neutral solution is obtained, from which upon evaporation of approximately 300 ml. in vacuo the remaining pyridine is removed.
• the copolymer is composed of the following recurring units, which are randomly distributed over the polymer chains:
• the emulsion is stirred for another 90 minutes at 70 C.
• the copolymer is isolated from the latex by the addition of methanol.
• the precipitated copolymer of fi-chloroethyl acrylate and acrylic acid is purified by dissolving in acetone and pouring in water.
• the resulting solution is heated to 70 C. and maintained at this temperature for 3 /2 hours, while a nitrogen current is led through it.
• Copolymer of vinylbenzyltrimethylammonium chloride, vinyl benzyl chloride, and sodium acrylate (A) Copolymer of vinyltoluene and acrylic acid.In a reaction vessel of 500 ml. equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, 3.21 g. of a 90% aqueous solution of dodecylated oxydibenzene disodium sulphonate, 10.3 g. of 28% aqueous solution of the sodium salt of tetradecyl sulphate, and 1.16 g. of ammonium persulphate are dissolved in 250 ml. of demineralized water.
• the copolymer has an intrinsic viscosity of 1.26 dl./g. in butanone at C.
• (B) Copolymer of chloromethylstyrene and acrylic acid In a reaction vessel equipped with a reflux condenser, a stirrer, and a dropping funnel, 60.8 g. of the copolymer of vinyltoluene and acrylic acid prepared as described above are dissolved in 600 ml. of carbon tetrachloride. Then 100 ml. of liquid are distilled from this solution, whereupon 500 mg. of benzoyl peroxide are added. Subsequently 135 g. of sulphuryl chloride are added dropwise at 70 C. As the chlorination is exothermic this dropwise addition is regulated in such a way that the whole amount of sulphuryl chloride is added within 45 minutes. Sulphur dioxide and hydrochloric acid evolve through the reflux condenser.
• reaction medium is then maintained at 70 C. for 3 /2 more hours while stirring, diluted with 300 m1.
• the quaternization is slightly exothermic and the temperature rises to C.
• the mixture is then heated to C. and the quaternization is allowed to continue for 4 hours at the same temperature.
• copolymer having an intrinsic viscosity of 0.216 dl./g. in a N/ 10 aqueous solution of sodium chloride at 2 5 C.
• the copolymer comprises the following randomly distributed recurring units in a proportion of 29.5, 65.3 and 5.2 mole percent respectively:
• the soluble fraction is filtered off and poured in a mixture of 500 ml. of benzene and 500 ml. of acetone.
• the residue is dissolved in water and the pH of the solution is brought to 7 by the addition of sodium hydroxide.
• the solution is then concentrated by evaporation to 60 ml.
• the reaction mixture is concentrated by evaporation in vacuo to 100 ml. and then poured in 1 1. of methanol. After filtration and washing with 300 ml. of methanol, the copolymer is dissolved in water.
• a mixture of 14.8 ml. of 40% aqueous solution of trimethylamine and 15 ml. of dimethylformamide is added dropwise at room temperature to this solution.
• the solution is heated to 35 C.
• ml. of Water By adding ml. of Water to the turbid solution it becomes clear. After 10 minutes another 10 ml. of water are added. Subsequently the reaction temperature is maintained at 35 C. to 2 hours.
• the copolymer is isolated by pouring in acetone. The total bulk is then dissolved again in water and the pH of the resulting solution is brought at 7 by the addition of sodium hydroxide.
• the mixture is then heated to 40 C. for 1 hour and subsequently at reflux temperature for 1 hour,
• the copolymer is isolated by the addition of a little amount of hydrochloric acid, washed with water till free of hydrochloric acid, and dissolved in water by the addition of trimethylamine.
• the solution contained 130 g. of copolymer with the following recurring units:
• copolymer is composed of randomly distributed units according to the following formulae:
• a homogeneous latex is obtained, from which the copolymer of styrene, acrylic acid, and B-chloroethyl acrylate is isolated.
• the powdery precipitate is brought in 600 ml. of methanol, washed with 400 ml. of methanol, sucked off, and dried in vacuo at room temperature.
• the copolymer comprises 10.4 mole percent of acrylic acid, 5.5 mole percent of fi-chloroethyl acrylate; and 84 mole percent of styrene.
• Proportion of the recurring units 63, 13.5, and 2.5 mole percent. The remaining 21 mole percent are nonmodified styrene units.
• Proportion of the recurring units 54, 7.5, and 38.5 mole percent respectively.
• the mixture is stirred for 15 minutes at 70 C., whereupon the homogeneous solution is poured in a mixture of 500 ml. of acetone and 500 ml. of methanol.
• the sticky residue is washed twice with a mixture of 200 ml. of acetone and 200 ml. of methanol and then dissolved in water.
• the proportion of recurring units in the copolymer is as follows: 22.5, 26.2, 40.1, 11.2 mole percent respectively.
• the sodium acrylate units resulted from the partial saponification of B-chloroethyl acrylate units.
• copolymer An amount of 930 ml. of solution is obtained comprising 99 g. of copolymer.
• the copolymer contains 20 mole percent of styrene, 65 mole persent of sodium methacrylate, and 15 mole percent of B-chloroethyl acrylate.
• the intrinsic viscosity of the copolymer is 0.35 dl./g. in methanol at 25 C.
• a homogeneous solution is obtained, from which the copolymer is isolated by decanting in a mixture of equal volumes of methanol and acetone. The sticky residue is washed twice with a mixture of 200 ml. of acetone and 200 ml. of methanol and then dissolved in water.
• the surface resistivity of the different copolymers according to Preparations 1 to 28 is measured.
• Examples 6 to 11 the application of electroconductive polymeric materials according to the invention is described as antistatic agents in normal photographic materials, whereas in Examples 2 to 5 their application in electrophotographic recording elements is described.
• Example 12 the use of the electroconductive copolymers of the invention is described in the manufacture of a recording material in which information is stored in the form of electric charges on a dielectric surface.
• the storage surface consists of a mosaic of small squares of conductive material on the dielectric plate.
• This mosaic of conductive squares is manufactured by exposing a layer of conductive copolymer, mixed with a finely divided black pigment, through a dot-screen to short duration high-intensity flashes, e.g. of an electronic flash lamp, or by exposing the layer through the same screen at a temperature between 50 and 200 C. for longer periods of time.
• the exposed areas of the conductive copolymer layer become cross-linked and then insoluble in water or organic solvents, whereas the noncrosslin'ked areas can be washed away, leaving a mosaic of electroconductive squares on the dielectric surface.
• These squares can be image-wise charged electrically, e.g. by means of a charged needle, and the charges can be developed electrophoretically to a visible image.
• copolymers of the invention may also be used in other electrographic processes. A survey of these different processes has been given by C. J. Claus in Phot. Sci. Eng. 7 (1963) pages 5-13.
• the electroconductive polymers may be used in combination with coatings of various inorganic as well as organic photoconductive substances such as those described in the Belgian patent specification 587,300, filed February 1969 by Gevaert Photo-Producten N.V., the United Kingdom patent specifications 964,871, filed Feb. 26, 1959, 964,873 filed Mar. 30, 1960, 964,874 filed Mar. 30, 1960, 964,875 filed Apr. 21, 1960, 964,876 filed Apr. 21, 1960, 964,877 filed May 2, 1960, 964,879 filed Apr.
• Suitable dispersing agents for dispersing photoconductive materials in an aqueous medium are described in the French patent specification 1,540,020 filed Sept. 4, 1967 by Gevaert-Agfa N.V. and as is generally known the photoconductive substances can be spectrally sensitized, e.g. as described in the French patent specifications 1,547,- 196 filed Dec. 14, 1967 and 1,560,976 filed Apr. 24, 1968 both by Gevaert-Agfa N.V.
• EXAMPLE 1 An aqueous solution of the copolymers described in the preceding preparations was coated on a glassine paper of '60 g. per sq. m. in such a Way that 2 g. of solids were present per sq. m. The coated layer was dried first at 30 to 40 C. and subsequently dried thoroughly at 100 C. The total drying time may be varied between two and fifteen minutes, without impairing the photographic results.
• Table I shows the results obtained upon measurement of the surface resistivity of these layers. At the same time the degree of solubility in water after drying is given.
• EXAMPLE 2 A glassine paper weighing 60 g. per sq. m. was coated as described in Example 1 with an aqueous solution of the copolymer of N-acryloyloxyethylpyridinium chloride, fl-chloroethyl acrylate, and sodium acrylate of preparation 1 in a ratio of 2 g. of solid copolymer per sq. m., and dried as specified in Example 1.
• composition was sensitized with Direct Green 59 (Colour Index 34,040) on the form of a 0.5 solution in water. An amount of 1.5 ml. of this sensitizer solution was added together with 1.75 ml. of Mordant Red 5 (Colour Index 14,290) in the form of a 0.5% solution in water.
• the photoconductive dispersion essentially consisting of zinc oxide as described above was coated on the previously coated and dried layer consisting of the above copolymer of N-acryloyloxyethylpyridinium chloride, e-chloroethyl acrylate, and sodium acrylate.
• the zinc oxide layer was dried for minutes at 100 C.
• the dried photoconductive material as prepared above produced sharp and contrasting images after storage in the dark for some hours, image-wise exposure and development according to standard electrophotographic techniques.
• the quality of the images obtained was not only determined by the inherent properties of the photoconductive zinc oxide layer, for which we refer to the French patent specification 1,547,196 filed Dec. 12, 1967 by Gevaert-Agfa N.V., but also by the highly electroconductive copolymer layer.
• Example 3 The process of Example 2 was repeated with the proviso, however, that the conductive copolymer used in the first coating was replaced by the copolymer of 1,2-dimethyl-5-vinylpyridinium methylsulphate, B-chloroethyl acrylate, and sodium acrylate of Preparation 5.
• the dried photoconductive material when stored in the dark for some hours, produced sharp and contrasting images upon image-wise exposure and development as indicated in Example 2.
• a photoconductive zinc oxide dispersion having the following composition was coated on this conductive paper base:
• composition was treated once in a homogenizer at 250 kg./ sq. cm. A composition comprising the following ingredients was then added thereto:
• the resulting layer was dried and upon dark adaptation fed into a common development apparatus for electrophotographic material. A sharp image, which entirely met the presently set commercial standards, was obtained.
• EXAMPLE 5 The good properties of the conductive polymers as described in this invention also mainfested themselves when an organic semiconductor was coated on such conductive base paper as described in Example 3.
• the organic semiconductor layer was coated from the following composition:
• This composition was coated on the electroconductive paper web, so that upon drying 2.5 g. of solid matter were present per sq. m.
• the layer was charged by means of a negative corona discharge, exposed to an incandescent bulb through a 0.3 wedge, and developed electrophoretically. An image of the wedge was obtained with a maximum density that was typical for highly conductive supports.
• the thickness of the resulting layers was 0.15 g./sq. m. After drying for 5 minutes at 100 C. a clear layer was obtained, which adhered excellently to the cellulose triacetate film support.
• the surface resistivity of the resulting material was then measured and compared with that of a same cellulose triacetate film, which, however, had not been provided with an antistatic layer.
• the comparison material had a surface resistivity of more than 500 10 ohm/10 sq. cm. in both cases.
• the processing was carried out in common photographic baths, viz. 5 minutes in an alkaline developing bath, whereupon the materials were rinsed with pure water, and minutes in an acid fixing bath, whereupon the material was rinsed for 1 hour with running water.
• EXAMPLE 7 A cellulose triacetate support containing by weight of triphenyl phosphate was coated with an antistatic layer from the following solution at a ratio of 0.12 g. of polymer/sq. m.:
• the comparison material had a surface resistivity above 500x 10 ohm/ 10 sq. cm.
• the same photographic processing baths were used as in Example 6.
• EXAMPLE 8 A biaxially oriented polyethylene terephthalate support was coated with an antistatic layer from the following composition at a ratio of 0.18 g. of polymer/sq. m.:
• the coated support was then dried for 5 minutes at 105 C., so that a clear layer was obtained, which adhered very well to the polyester support.
• a same polyethylene terephthalate support which, however, had not been provided with an antistatic layer, had a surface resistivity above 500 10 ohm/ 10 sq. cm.
• EXAMPLE 10 A non-stretched polyethylene terephthalate support was covered according to known methods with a subbing layer of a copolymer of vinyl chloride, vinylidene chloride, butyl acrylate, and itaconic acid (63:3025 :2 mole percent, whereupon the polyethylene terephthalate fihn was oriented. Subsequently, an antistatic layer was applied thereto from the following solution at a ratio of 0.25 g./ sq. m.:
• the surface resistivity of the resulting material was measured at different relative humidities before and after photographic processing as indicated in Example 6.
• EXAMPLE 11 A 10% by weight aqueous solution of the copolymer of styrene, maleic anhydride, and fl-chloroethyl acrylate (47.5 :547.5 mole percent as prepared in preparation 28 was formed. The pH-value of this solution was adjusted to 7.0 by addition of sodium hydroxide.
• gelatin subbing layer was applied thereto from a gelatin dispersion having the following composition:
• EXAMPLE 12 To a conductive support, e.g. an aluminum foil or an electroconductive paper, a layer of polystyrene or of an alkyd resin of thickness was applied. Onto this layer was coated a aqueous solution of copolymer of vinylbenzyltrimethylammonium chloride, vinylbenzyl chloride and sodium acrylate. This copolymer has been prepared according to the method of preparation 9 and thus contains 30, 61.2 and 8.8 mole percent respectively of the monomers mentioned. Of the solution formed 20 ml. were mixed with 30 ml. of water, 1 g. of carbon black, 1 ml. of saponine solution, and 5 ml. of ethanol. This mixture was applied to the insulating layer of polystyrene or alkyd resin in such a way that after drying a layer of some 5 1 was left.
• a conductive support e.g. an aluminum foil or an electroconductive paper.
• (C) 0 to 44 mole percent of monomeric units of at least one a,;8-ethylenically unsaturated monomer carrying an acidic group in free acid or salt form which is reactive with the reactive halogen atoms of units (B), at least about 5 mole percent of said units (C) being present where said units (A) are unreactive with the reactive halogen atoms of units said copolymer being initially water-soluble and converted by heating to 30-l80 C. to water-insoluble form by an internal cross-linking reaction between said reactive halogen atoms and at least one of the units (A) and units (C).
• Sheet material according to claim 1 wherein a photoconductive layer is applied to the electroconductive layer to form an electrophotographic recording element.
• Sheet material according to claim 1 wherein an insulating layer is applied to the electroconductive layer to form an electrographic recording element.
• Sheet material according to claim 1 wherein a gelatin subbing layer is applied to the electroconductive layer followed by a light-sensitive gelatin silver halide emulsion layer to form a photographic recording element.

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• Photoreceptors In Electrophotography (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)

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Publications (1)

Family

ID=9786853

Family Applications (1)

Country Status (11)

Cited By (20)

Families Citing this family (2)

• 1969
  • 1969-01-29 GB GB494669A patent/GB1301661A/en not_active Expired
• 1970
  • 1970-01-21 CA CA072757A patent/CA924585A/en not_active Expired
  • 1970-01-24 DE DE19702003191 patent/DE2003191A1/de not_active Withdrawn
  • 1970-01-26 CH CH94870A patent/CH563604A5/xx not_active IP Right Cessation
  • 1970-01-27 FR FR7002890A patent/FR2029625A1/fr not_active Withdrawn
  • 1970-01-28 BE BE745027D patent/BE745027A/nl unknown
  • 1970-01-28 AT AT77670A patent/AT299698B/de not_active IP Right Cessation
  • 1970-01-28 SE SE01082/70A patent/SE368099B/xx unknown
  • 1970-01-29 US US00006930A patent/US3708289A/en not_active Expired - Lifetime
  • 1970-01-29 NL NL7001273A patent/NL7001273A/xx unknown
• 1972
  • 1972-12-04 JP JP47121451A patent/JPS521664B1/ja active Pending

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