Transparent substrates

Abstract: A transparent substrate material for receiving a toner image comprises of a support substrate base, an antistatic polymer layer coated on one or both surfaces of the substrate and comprised of hydrophilic cellulosic components, and a toner-receiving polymer layer on one or each outer surface of the antistatic layers, which polymer is comprised of hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures thereof, and wherein the toner-receiving layer contains adhesive components.

Description: This invention relates generally to transparencies, which transparencies are particularly useful in electrographic and xerographic imaging and printing processes. More specifically, the present invention is directed to transparencies with certain coatings thereover, which transparencies, that is for example transparent substrate materials for receiving or containing a toner image, possess compatibility with toner compositions, and permit improved toner flow in the imaged areas of the transparency, thereby enabling images of high quality, that is for example images with optical densities of greater than 1.0 in several embodiments, excellent toned fix, about 100 percent in some instances, and no or negligible background deposits to be permanently formed thereon. Thus, in one embodiment of the present invention, there are provided transparencies useful in electrophotographic (including xerographic) imaging systems, which transparencies are comprised of a support substrate, a first coating of, for example, an antistatic hydrophilic hydroxyethyl cellulose polymer layer present on one or both sides of the substrate, and a second toner-receiving coating thereover of a hydrophobic blend of, for example, ethylhydroxyethyl cellulose and an epichlorohydrin/ethylene oxide copolymer, which blend can be present on one or both outer surfaces of the antistatic layer, and wherein the second layer may contain filler components. Also, the present invention is directed to imaged transparencies comprised of a support substrate, a first antistatic coating of, for example, a hydrophilic cellulose derivat ve polymer layer present on one or both surfaces of the substrate, and a second toner-receiving coating thereover, comprised of a hydrophobic cellulose ether or cellulose esters with low melt adhesives, such as ethylene/vinyl acetate copolymers and poly(chloroprene), and wherein the second layer may contain filler components. In the formation and development of xerographic images, there is generally applied to a latent image generated on a photoconductive member a toner composition comprised of resin particles and pigment particles. Thereafter, the image is transferred to a suitable substrate, and affixed thereto by, for example, heat, pressure, or a combination thereof. It is also known that transparencies can be selected as a receiver for the transferred developed image originating from the photoconductive member, which transparencies are suitable for selection with commercially available overhead projectors. Generally, these transparent sheets are Comprised of thin films of one or more organic resins, such as polyesters, which have the disadvantage that undesirable poor toner composition adhesion results in toner flaking off the transparency. In the Xerox Corporation 1005™ colorimaging apparatus, a black color can be obtained from a combination of magenta, cyan and yellow pigments in three passes, whereas in the Xerox Corporation 1025™ and 1075™ apparatuses this is achieved in one pass, using carbon black based toners. Generally, the amount of the three-pass images deposited toner layer of magenta, cyan, yellow to produce black, is greater than that of carbon black based toners deposited by single-pass copiers. Thus the 1005™ apparatus (black) requires more heat to fuse the three layers together on substrates such as transparencies compared with pigmented black produced by the Xerox corporation 1025™ or 1075™ apparatuses. Although these imaging apparatuses are equipped with variable fusing temperature options, there is an optimum temperature for maintaining an effective life span of the machine components; the lower the temperature, the longer the life span. To accommodate these transparency requirements, three-pass color copiers are often decelerated in the transparency mode to generate extra heat for toner fusing. However, this extra heat is usually not sufficient to the toner effectively fix to the transparency, and the toners are fused by a post-solvent treatment in a solvent vapor-fuser. These problems are avoided or minimized with the transparencies of the present invention. Many different types of transparencies are known, reference for example US-A-3,535, 112, which illustrates transparencies comprised of a support substrate, and polyamide overcoatings. Additionally, there are disclosed in US-A-3,539,340 transparencies comprised of a support substrate and coatings thereover of vinylchloride copolymers. Also known are transparencies with overcoatings of styrene acrylate, or methacrylate ester copolymers, reference US-A-4,071,362; transparencies with blends of acrylic polymers and vinyl chloride/vinylacetate polymers, as illustrated in US-A-4,085,245; and transparencies with coatings of hydrophilic colloids as recited in US-A-4,259,422. Furthermore, there is illustrated n(1) US-A-4,489, 122 transparencies with elastomeric polymers overcoated with poly(vinylacetate), or terpolymers of methylmethacrylate, ethyl acrylate, and isobutylacrylate; and (2) US-A-4,526,847 transparencies comprised of overcoating of nitrocellulose and a plasticizer. In a patentability search report the following US patents were cited: US-A3,488,189 which discloses fused toner images on an imaging surface wherein the toner particles contain a thermoplastic resin, the imaging surface carries a solid crystalline palsticizer having a lower melting point than the melting range of the thermoplastic resin, and wherein the resulting toner image is heat fused, reference the abstract of the disclosure; see also columns 3,4, and 5 especially at line 71 to column 6; a similar teaching is present in US-A-3,493,412 and 3,619,279, and more specifically the '279 patent mentions in the abstract that the external surface of the toner-receiving member is substantially free of a material plasticizable by a solid crystalline plasticizer, and typically a plasticizer such as ethylene glycol dibenzoate may be available on the surface of the paper; further see column 3 lines 22 to 32 of the '279 patent for the types of receiving surfaces that may be treated; and a selection of patents, namely US-A-3,535,112; 3,539,340; 3,539,341; 3,833,293; 3,854,942; 4,234,644; 4,259,422; 4,419,004; 4,419,005; and 4,480,003, that pertain to the preparation of transparencies by electrostatographic imaging techniques according to the aforementioned report Also known are transparent sheet materials for use in a plain paper electrostatic copiers comprising (a) a flexible, transparent, heat resistant, polymeric film base, (b) an image-receiving layer present upon a first surface of the film base, and (c) a layer of electrically conductive prime coat interposed between the image-receiving layer and the film base. This sheet material can be used in either powder-toned or liquid-toned plain paper copiers for making transparencies, reference US-A-4,711,816. Additionally known is a transparency to be imaged as a copy sheet in plain paper copiers, which transparency contains a transparent sheet having a surface adapted to receive an image imprinted thereon in a suitable electrostatic imaging apparatus, and an opaque coating forming an opaque border completely around the sheet, reference US-A-4,637,974. Moreover known is the preparation of transparencies by electrostatic means, reference US-A-4,370,379, wherein there is described the transferring of a toner image to a polyester film containing, for example, a substrate and a biaxially stretched poly(ethylene terephthalate) film, including 'Mylar' (trademark). Furthermore, in US-A-4,234,644, there is disclosed a composite laminated film for electrophoretically toned images deposited on a plastics dielectric receptor sheet comprising in combination an optically-transparent flexible support layer, and an optically-transparent flexible intermediate layer of a heat softenable film applied to one side of the support; and wherein the intermediate layer is adhered to the support. With further respect to the prior art, there are illustrated in US-A-4,370,379, transparencies with, for example, a polyester (Mylar) substrate with a transparent plastics film substrate 2, and an undercoating layer 3 formed on at least one surface of the substrate 2, and a toner-receiving layer 4 formed on the undercoated layer, reference column 2, line 44. As coatings for layer 3, there can be utilized the resins as illustrated in column 3, including quaternary ammonium salts, while for layer 4 there are selected thermoplastic resins having a glass transition temperature of from -50 to 150°C, such as acrylic resins, including ethylacrylate, methylmethacrylate, and propyl methacrylate; and acrylic acid, methacrylic acid, maleic acids, and fumaric acid, reference column 4, lines 23 to 65. At line 61 of this patent, there is mentioned that thermoplastic resin binders other than acrylic resins can be selected, such as styrene resins, including polystyrene, and styrene butadiene copolymers, vinyl chloride resins, vinylacetate resins, and soluble linear polyester resins. A similar teaching is present in US-A-4,480,003 wherein there is disclosed a transparent film comprised of a film base coated with an image-receiving layer containing thermoplastic transparent polymethacrylate polymers, reference column 2, line 16, which films are useful in plain paper electrostatic copiers. Other suitable materials for the image receiving layer include polyesters, cellulosics, poly(vinyl acetate), and acrylonitrile-butadiene-styrene terpolymers, reference column 3, lines 45 to 53. Similar teachings are present in US-A-4,599,293, wherein there is described a toner transfer film for picking up a toner image from a toner treated surface, and affixing the image, wherein the film contains a clear transparent base and a layer firmly adhered thereto, which is also clear and transparent, and is comprised of the specific components as detailed in column 2 line 16. Examples of suitable binders for the transparent film that are disclosed in this patent include polymeric or prepolymeric substances, such as styrene polymers, acrylic, and methacrylate ester polymers, styrene butadienes, isoprenes, and the like, reference column 4, lines 7 to 39. The coatings recited in the aforementioned patents contain primarily amorphous polymers which do not undergo the desired softening during the fusing of the xerographic imaging processes such as the color process utilized in the Xerox Corporation 1005™, and therefore these coatings do not usually aid in the flow of pigmented toners. This can result in images of low optical density which are not totally transparent. There is described in JP-A-63-259 671 transparencies suitable for electrographic and xerographic imaging comprised of a polymeric substrate with a toner-receptive coating on one surface thereof, which coating is comprised of blends of: poly(ethylene oxide) and carboxymethyl cellulose; poly(ethylene oxide), carboxymethyl cellulose and hydroxypropyl cellulose; poly(ethylene oxide) and vinylidene fluoride/hexafluoropropylene copolymer, poly(chloroprene) and poly(n-methylstyrene); poly(caprolactone) and poly(a-methylstyrene); poly(vinylisobutylether) and poly(nmethylstyrene); blends of poly(caprolactone) and poly(p.isopropyl n-methylstyrene); blends of poly(1,4-butylene adipate) and poly(α-methylstyrene); chlorinated poly(propylene) and poly(α-methylstyrene); chlorinated poly(ethylene) and poly(α-methylstyrene); and chlorinated rubber and poly(n-methylstyrene). Further there are provided transparencies suitable for electrographic and xerographic imaging processes comprised of a supporting polymeric substrate with a toner-receptive coating on one surface thereof comprised of: (a) a first layer coating of a crystalline polymer selected from the group consisting of poly(chloroprene), chlorinated rubbers, blends of poly(ethylene oxide), and vinylidene fluoride/hexafluoropropylene copolymers, chlorinated poly(propylene), chlorinated poly(ethylene), poly(vinylmethyl ketone), poly(caprolactone), poly(1,4-butylene adipate), poly(vinylmethyl ether), and poly(vinyl isobutylether); and (b) a second overcoating layer comprised of a cellulose ether selected from the group consisting of hydroxypropyl methyl cellulose, hydroxypropyl cellulose, and ethyl cellulose. Although the transparencies prepared with the coatings mention in the above-mentioned copending application usually have higher optical densities than those obtained on commercially available (Xerox Corporation 3R2780) transparencies, when imaged with the Xerox Corporation 1005™, vapor fusing was necessary with for example, the apparatus commercially available from Xerox Corporation as the Xerox VFA, for a period of 60 seconds with a solvent such as 1.1.1 trichloroethane to render them transparent. This disadvantage is avoided with the transparencies of the present invention. Further, although known transparencies are suitable in most instances for their intended purposes, there remains a need for new transparencies with coatings thereover, which transparencies are useful in electrophotographic and xerographic imaging processes, and that will enable the formation of images with high optical densities. Additionally, there is a need for transparencies which permit improved toner flow in the imaged areas, thereby enabling high-quality transparent images with acceptable optical densities. There is also a need for transparencies with specific coatings that possess other advantages, inclusive of enabling excellent adhesion between the toned image and the transparency or coated papers selected, and wherein images with excellent resolution and no background deposits are obtained. There is also a need for transparencies that can be used in more than one type of xerographic or electrophotographic apparatuses, as is the situation with the transparencies of the present invention. Another need met by the present invention resides in providing transparencies with coatings that do not (block) stick at, for example, high relative humidities of, for example, 50 to 80 percent relative humidity, and at a temperature of 50°C in many embodiments. Accordingly the present invention provides transparent coated substrates as claimed in the appended claims.In accordance with one embodiment of the present invention there are provided transparencies with coatings thereover which are compatible with the toner compositions selected for development, and wherein the coatings enable images thereon with acceptable optical densities to be obtained. More specifically, in one embodiment of the present invention there are provided transparencies for xerographic and ionographic processes comprised of a support substrate and a first coating of, for example, hydrophilic hydroxyethyl cellulose, and a second coating thereover of a hydrophobic blend of ethylhydroxyethyl cellulose with a low melting adhesive component such as an epichlorohydrin/ethylene oxide copolymer. Another embodiment of the present invention is directed to a transparency or a transparent substrate for receiving a toner image comprised of a support substrate, an antistatic polymer layer coated on both sides of the substrate and comprised of hydrophilic cellulosic derivatives, and a toner-receiving polymer layer on both surfaces of the antistatic layers, which polymer is comprised of hydrophobic cellulose ethers or cellulose esters, and wherein the tonerreceiving layer contains low melt adhesive components. Also, the present invention is directed to a transparency comprised of a support substrate, an antistatic polymer layer coating, and a toner-receiving polymer layer, which polymer is comprised of hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures or blends thereof, and low melt adhesive components, which transparency can have thereon developed images. With the transparencies of the present invention there is provided, for example, the elimination of the post solvent treatment, since the transparency contains a low melt adhesive component which softens during the toner fusing process and aids in toner flow to yield high optical density transparent images. In yet another embodiment, the present invention is directed to transparencies comprised of a support substrate such as a polyester; a hydrophilic transparent layer which functions primarily as an antistatic layer, such as hydroxy ethyl cellulose; and a top toner-receiving coating of a hydrophobic blend of ethylhydroxyethyl cellulose and a low melting adhesive such as an epichlorohydrin/ethylene oxide copolymer. This two-layered structure of antistatic layer in contact with the toner-receiving layer is preferably present on both surfaces of the support substrate. Also, the polymeric components of the toner-receiving layer which may be present on one surface of the transparency may be the same as those present on the other, but in different proportions, for example, a blend of ethylhydroxyethyl cellulose, 30 percent by weight and epichlorohydrin/ethylene oxide copolymer, 70 percent by weight can be used on one surface as a toner-receiving layer for the Xerox Corporation 1005, whereas a blend of ethylhydroxyethyl cellulose, 50 percent by weight, and epichlorohydrin/ethylene oxide copolymer, 50 percent by weight, can be used on the other surface for carbon black toners; or they may be different, for example a blend of ethylhydroxyethyl cellulose with epichlorohydrin/ethylene oxide can be used as a toner-receiving layer on one surface, whereas on the other surface a blend of ethylhydroxyethyl cellulose with ethylene/vinyl acetate copolymer may be selected. Specifically, in one embodiment of the present invention there are provided image transparencies comprised of a support substrate such as a polyester; an antistatic polymer layer, comprised of cellulosic components, such as hydroxyethyl cellulose, water-soluble ethyl hydroxy ethyl cellulose (preferably with a degree of ethyl substitution less than 0.8), diethyl aminoethyl cellulose quaternized, hydroxy propyl trimethyl ammonium chloride hydroxyethyl cellulose quaternized and sodium carboxymethyl cellulose; and a toner-receiving layer thereover comprised of hydrophobic cellulose ether, esters, mixtures thereof, and the like, including specifically mixtures, comprised for example of two or more polymers, in a common solvent, of ethylhydroxyethyl cellulose with low melting adhesives such as epichlorohydrin/ethylene oxide copolymer; blends of ethylhydroxyethyl cellulose with ethylene/vinyl acetate copolymer; blends of ethylhydroxyethyl cellulose with poly(caprolactone); blends of ethylhydroxyethyl cellulose with poly(chloroprene); blends of ethylhydroxyethyl cellulose with styrene-butadiene copolymers; blends of ethyl cellulose with epichlorohydrin/ethylene oxide copolymer; blends of cellulose acetate hydrogen phthalate with ethylene/vinyl acetate copolymer; blends of cellulose acetate phthalate with ethylene/vinyl acetate copolymer; blends of hydroxypropyl methyl cellulose phthalate with ethylene/vinyl acetate copolymers; blends of cellulose acetate butyrate with ethylene/vinyl acetate copolymer; and blends of cellulose acetate with ethylene/vinyl acetate copolymer, wherein each blend contains an effective amount of polymer, such as from 10 to 90 percent by weight of a first polymer, and from 90 to 10 weight percent of a second polymer. Blends containing more than two polymers, present in effective amounts, may also be selected in some embodiments of the present invention. The blends mentioned herein refer in most instances to the ink-receiving polymer component of the hydrophobic cellulose, hydrophobic cellulose ester, or mixtures thereof and a low melting adhesive. Therefore the toner-receiving layer can be comprised of hydrophobic cellulose ether, esters, mixtures thereof, and the like, and low melting adhesive components. Examples of the low melting adhesive components mentioned herein, which components provide for the surface of the transparency to soften, thereby permitting effective acceptance of toner, include epichlorohydrin/ethylene oxide copolymer, ethylene/vinyl acetate copolymer, poly( chloroprene), poly(caprolactone), styrene/butadiene copolymers, mixtures thereof, and the like. The adhesive is usually present in effective amounts of for example from 10 to 90 weight percent ,and generally these adhesives have a low melting temperature of from 50 to 75°C. Illustrative examples of support substrates with a thickness of from 50 to 150 um, and preferably of a thickness of from 75 to about 125 m that may be selected for the transparencies of the present invention include 'Mylar', commercially available from E.l. Dupont; 'Melinex', commercially available from Imperial Chemical Inc.; 'Celenar', commercially available from Celanese, Inc.; polycarbonates, especially 'Lexan'; polysulfones, cellulose triacetate; polyvinyl chlorides; and the like, with 'Mylar' being particularly preferred because of its availability and lower cost. Specific examples of antistatic layer coating polymers of an effective thickness, for example, from 2 to 10 µm for one or each surface of the support substrate and in contact with the support substrate, that can be selected for the aforementioned transparencies include, sodium carboxymethyl, cellulose (CMC 7MF, Hercules), hydroxyethyl cellulose (Natrosol 250 LR, Hercules), water-soluble ethyl hydroxy ethyl cellulose (Bermocoll, Berol Kemi AB, Sweden), hydroxypropyl trimethyl ammonium chloride hydroxyethyl cellulose (Celquat H-100, L-200 National Starch), and diethyl ammonium chloride hydroxyethyl cellulose (DEAE Cellulose, quaternized). Preferred antistatic layer polymers include hydroxyethyl cellulose and hydroxypropyl trimethyl ammonium chloride hydroxyethyl cellulose primarily since they are readily available and possess excellent properties as antistatic materials. The antistatic layer is usually coated on both surfaces of the support substrate. Illustrative examples of toner-receiving layers of, for example, a thickness of from 1 to 5 µm and present on one or each surface of the antistatic layer, and in contact with it, include the cellulose components illustrated herein such as blends of hydrophobic ethylhydroxyethyl cellulose (EHEC preferably with a degree of ethyl group substitution of between 0.8 and 2.0, available form Hercules Chemical), from 10 to 90 percent by weight and epichlorohydrin/ethylene oxide copolymer (Herclor C Hercules Inc., Hydrin 200 available from S.F. Goodrich with an epichlorohydrin content of 65 percent by weight) from 90 to 10 percent by weight in toluene; blends of hydrophobic ethylhydroxyethyl cellulose (EHEC, Hercules) from 10 to 90 percent by weight, and ethylene/vinyl acetate (EVA copolymer with a vinyl acetate content of 40 percent by weight, available from Scientific Polymer Products) from 90 to 10 percent by weight in toluene; blends of hydrophobic ethylhydroxyethyl cellulose (EHEC, Hercules) from 10 to 90 percent by weight and poly caprolactone (PLC-700, Union Carbide) from 90 to 10 percent by weight in toluene; blends of hydrophobic ethylhydroxyethyl cellulose (EHEC, Hercules) from 10 to 90 percent by weight and poly(chloroprene) (Scientific Polymer Products) from 90 to 10 percent by weight in toluene; blends of hydrophobic ethylhydroxyethyl cellulose (EHEC, Hercules) from 10 to 90 percent by weight and styrene-butadiene copolymers (Scientific Polymer Products with butadiene content of from 10 to 80 percent by weight) from 90 to percent by weight in toluene; blends of hydrophobic ethyl cellulose (Ethocel, Hercules) from 10 to 90 percent by weight and epichloro hydrin/ethylene oxide (Herclor C, Hercules) from 90 to 10 percent by weight in toluene; blends of cellulose acetate hydrogen phthalate (CAHP, Eastman Kodak 6) from 10 to 90 percent by weight and ethylene/vinyl acetate (Scientific Polymer Products, with vinyl acetate content of between 40 to 70 percent by weight) from 90 to 10 percent by weight in acetone; blends of hydroxy propylmethyl cellulose phthalate (HPMCP, Shin-Etsu Chemical) from 10 to 90 percent by weight and ethylene/vinyl acetate copolymer (Scientific Polymer Products, with vinyl acetate content of between 40 to 70 percent by weight) from 90 to 10 percent by weight in acetone; blends of cellulose acetate phthalate (CAP, Eastman Kodak Company) from 10 to 90 percent by weight and ethylene/vinyl acetate copolymer (Scientific Polymer Products, with vinyl acetate content of between 40 and 70 percent by weight) from 90 to 10 percent by weight in acetone; blends of cellulose acetate butyrate (CAB, Scientific Polymer Products) from 10 to 90 percent by weight and ethylene/vinyl acetate copolymer (Scientific Polymer Products, with a vinyl acetate content of between 40 to 70 percent by weight) from 90 to 10 percent by weight in acetone; blends of cellulose acetate (Scientific Polymer Products) from 10 to 90 percent by weight and ethylene/vinyl acetate (Scientific Polymer Product, with a vinyl acetate content of between 40 and 70 percent by weight) from 90 to percent by weight in acetone, and the like. The blends can be comprised of from 10 to 90 percent by weight of one polymer, and from 90 to 10 weight percent of a second polymer. The toner-receiving layer for the developed image may include filler components in various effective amounts such as, for example, from 2 to 25 weight percent. Examples of fillers include colloidal silicas preferably present, for example, in one embodiment in an amount of 5 weight percent (available as Syloid 74 from W.R. Grace Company); calcium carbonate, titanium dioxide (Rutile), and the like. While it is not desired to be limited by theory, it is beleived that the primary purpose of the fillers is as a slip component for the transparency traction during the feeding process. Specific examples of toner-receiving layer components of for example, a thickness of from 1 to 7 µm and in contact with both surfaces of the antistatic layers, for transparencies selected for three-pass color processes include blends of hydrophobic ethylhydroxyethyl cellulose, 30 percent by weight and epichlorohydrin/ethylene oxide copolymer (Epichlorohydrin content 65 percent by weight) 70 percent by weight, blends of hydrophobic ethylhydroxyethyl cellulose, 40 percent by weight and ethylene/vinyl acetate copolymer (vinyl acetate content 40 percent by weight) 60 percent by weight; blends of hydrophobic ethylhydroxyethyl cellulose, 50 percent by weight and poly (caprolactone) 50 percent by weight; blends of hydrophobic ethylhydroxy ethyl cellulose, 30 percent by weight and poly (chloroprene), 70 percent by weight; blends of hydrophobic ethylhydroxy ethyl cellulose, 10 percent by weight and styrene-butadiene block copolymer (styrene content 30 percent by weight), 90 percent by weight; blends of hydrophobic ethyl cellulose, 30 percent by weight and epichlorohydrin/ethylene oxide copolymer (epichlorohydrin content of 65 percent by weight) 70 percent by weight; blends of cellulose acetate hydrogen phthalate, 40 percent by weight and ethylene/vinyl acetate copolymer (vinyl acetate content 70 percent by weight) 60 percent by weight; blends of hydroxypropyl methyl cellulose phthalate, 40 percent by weight and ethylene/vinyl acetate copolymer (vinyl acetate content of 70 percent by weight) 60 percent by weight; blends of cellulose acetate phthalate, 40 percent by weight and ethylene/vinyl acetate (vinyl acetate content of 70 percent by weight) 60 percent by weight; blends of cellulose acetate butyrate, 40 percent by weight, and ethylene/vinyl acetate copolymer (vinyl acetate content 70 percent by weight) 60 percent by weight; and blends of cellulose acetate 40 percent by weight and ethylene/vinyl acetate (vinyl acetate content 70 percent by weight) percent by weight. Examples of specific toner-receiving layer compositions, of for example a thickness of from 1 to 10 µm and in contact with both surfaces of the antistatic layer, for transparencies preferably selected for single-pass carbon black based copiers include: blends of hydrophobic ethylhydroxyethyl cellulose; 50 percent by weight and epichlorohydrin/ethylene oxide copolymer (epichlorohydrin content 65 percent by weight) percent by weight; blends of hydrophobic ethylhydroxyethyl cellulose 60 percent by weight and ethylene/vinyl acetate copolymer (vinyl acetate content 40 percent by weight) percent by weight; blends of hydrophobic ethylhydroxy ethyl cellulose, 70 percent by weight and poly (caprolactone, 30 percent by weight); blends of hydrophobic ethylhydroxyethyl cellulose 50 percent by weight and poly (chloroprene) 50 percent by weight; blends of hydrophobic ethylhydroxyethyl cellulose 30 percent by weight and styrene-butadiene block copolymer (styrene content, 30 percent by weight) 70 percent by weight; blends of hydrophobic ethyl cellulose 50 percent by weight and epichlorohydrin/ethylene oxide copolymer (epichlorohydrin content 65 percent by weight) percent by weight; blends of cellulose acetate hydrogen phthalate, 60 percent by weight and ethylene/vinyl acetate (vinyl acetate content 70 percent by weight) 40 percent by weight; blends of hydroxypropyl methyl cellulose phthalate 60 percent by weight, and ethylene/vinyl acetate (vinyl acetate content 70 percent by weight) 40 percent by weight; blends of cellulose acetate butyrate 60 percent by weight and ethylene/vinyl acetate (vinyl acetate content 70 percent by weight) 40 percent by weight and blends of cellulose acetate 60 percent by weight and ethylene/vinyl acetate (vinyl acetate content of 70 percent by weight) 40 percent by weight. The preferred toner-receiving layer polymers are blends of hydrophobic ethylhydroxyethyl cellulose with epichlorohydrin/ethylene oxide copolymer and blends of cellulose acetate butyrate with ethylene/vinyl acetate copolymer because of their easy availability, low cost and high performance that is color copier images with optical density of 1.7 to 1.8 for black, 0.85 to 0.95 for yellow, 1.45 to 1.50 for cyan and 1.43 to 1.65 for magenta. The aforementioned polymer antistatic and toner-receiving components can be present on the support substrates, such as of 'Mylar' or paper in various thicknesses depending on the coatings selected and the other components utilized; however, generally the total thickness of the polymer coatings is from 3 to 15 µm, and preferably from 7 to 10 µm. Moreover, these coatings can be applied by a number of known techniques, including reverse roll, extrusion and dip coating processes. In dip coating, a web of material to be coated is transported below the surface of the coating material by a single roll in such a manner that the exposed site is saturated, followed by the removal of any excess by a blade, bar or squeeze rolls. With reverse roll coating, the premetered material is transferred from a steel applicator roll to the web material moving in the opposite direction on a backing roll. Metering is performed in the gap by precision-ground chilled iron rolls. The metering roll is stationary or rotates slowly in the opposite direction to the applicator roll. In slot extrusion coating there is selected a slot die to apply coating materials, with the die lips in close proximity to the web of material to be coated. Once the desired amount of coating has been applied to the web, the coating is dried at 70 to 100°C in an air dryer. In one specific process embodiment, the transparencies of the present invention are prepared by providing a support substrate such as of 'Mylar' in a thickness of from 75 to 125 µm; and applying to each surface of the substrate by dip coating, in a thickness of from 2 to 10 µm, the antistatic layer such as a hydrophilic hydroxyethyl cellulose. Thereafter the antistatic coatings are air dried at 25°C for 60 minutes in a fume hood equipped with adjustable volume exhaust system, and the resulting transparency is subsequently dip-coated with a toner-receiving layer comprised, for example, of a blend of hydrophobic ethylhydroxyethyl cellulose and epichlorohydrin/ethylene oxide copolymer in a thickness of from 1 to 5 µm. Coating is effected from 3 percent by weight of the polymer blend in toluene. Thereafter, the coating is air dried and the resulting two-layered transparency can be utilized in various imaging apparatuses. The optical density measurements recited herein, including the working examples, were obtained on a Pacific Spectrograph Color System. The system consists of two major components: an optical sensor and a data terminal. The optical sensor employs a 125 mm integrating sphere to provide diffuse illumination and 8 degrees viewing. This sensor can be used to measure both transmission and reflectance samples. When reflectance samples are measured, a specular component may be included. A high resolution full dispersion, grating monochromator was used to scan the spectrum from 380 to 720 nanometers. The data terminal features a 300 mm CRT display, numerical keyboard for selection of operating parameters, and the entry of tristimulus values; and an alphanumeric keyboard for entry of product standard information. The following examples are being supplied to exemplify specific embodiments of the present invention, it being noted that these examples are intended to illustrate and not limit the scope of the present invention. Parts and percentages are by weight unless otherwise indicated. EXAMPLE I There were prepared 10 coated transparenct sheets each with a thickness of 100 µm by dip coating these sheets into a coating solution of hydroxyethyl cellulose available as Natural 250 LR and obtained from Hercules Chemical Company, which solution was present in a concentration of 3 percent by weight in water. Subsequent to air drying for 60 minutes at 25°C in a fumehood equipped with adjustable volume exhaust system, and monitoring the difference in weight prior to and subsequent to coating, these dried sheets had present on each side 300 milligrams, 3 µm in thickness of the antistatic polymer layer of hydroxyethyl cellulose polymer. These sheets were then coated on both sides with a toner-receiving layer comprised of a blend of cellulose acetate butyrate obtained from Scientific Polymer Products Inc. 60 percent by weight and a ethylene/vinyl acetate copolymer low melting adhesive component obtained from Scientific Polymer Products lnc.(vinyl acetate content 70 percent by weight) 40 percent by weight, which blend was present in acetone in a concentration of 2 percent by weight. Subsequent to air drying for minutes at 25°C and monitoring the difference in weight prior to and subsequent to coating, the coated sheets had present on each side 200 milligrams, 2 µm in thickness, of the toner-receiving polymer layer in contact with the hydroxyethyl cellulose. These sheets were then fed into a color imaging apparatus and images were obtained on the aforementioned transparencies with an average optical density (that is the sum of the optical densities of the 10 sheets divided by 10) of 1.77 (black), 0.85 (yellow), 1.45 (cyan) and 1.62 (magenta). These images could not be handwiped or lifted with adhesive tape 60 seconds subsequent to their preparation. EXAMPLE II There were prepared 10 coated transparent sheets of a thickness of 100 µm by dip coating these sheets into a coating solution of the hydroxyethyl cellulose of example 1, which solution was present in a concentration of 3 percent by weight in water. Subsequent to similar air drying for 60 minutes at 25°C these sheets were then coated on both sides with a blend of hydrophobic ethylhydroxyethyl cellulose, obtained from Hercules Chemical Company Products Inc. 30 percent by weight and epichlorophydrin/ethylene oxide copolymer adhesive obtained from Scientific Polymer Products Inc. (epichlorohydrin content 65 percent by weight) 70 percent by weight, which blend was present in toluene in a concentration of 2 percent by weight. Subsequent to air drying for 60 minutes at 25°C and monitoring the difference in weight prior to and subsequent to coating, the coated sheets had present on each side 200 milligrams, 2 µm in thickness, of the toner-receiving polymer layer-in contact with the antistatic polymer layers of hydroxyethyl cellulose. These sheets were then fed into a color imaging apparatus and images were obtained on the aforementioned transparencies with an average optical density (that is the sum of the optical densities of the 10 sheets divided by 10) of 1.70 (black), 0.92 (yellow), 1.48 (cyan) and 1.45 (magenta). These images could not be handwiped or lifted with adhesive tape 60 seconds subsequent to their preparation. EXAMPLE III There were prepared 10 coated transparent sheets of a thickness of 100 µm by dip coating them into a solution of ethylhydroxyethyl cellulose, which solution was present in a concentration of 3 percent by weight in water. Subsequent to air drying for 60 minutes at 25°C these sheets were then coated on both sides with a toner-receiving polymer layer of hydroxypropyl methyl cellulose phthalate, 60 percent by weight and ethylene/vinyl acetate copolymer adhesive, (vinyl acetate content 70 percent by weight) 40 percent by weight, which blend was present in acetone in a concentration of 2 percent by weight. Subsequent to air drying for 60 minutes at 25°C, the coated sheets had present on each side 200 milligrams, 2 µm in thickness, of the toner-receiving polymer layers in contact with the antistatic polymer layers of ethylhydroxyethyl cellulose. These sheets were then fed into an imaging apparatus and images were obtained on the transparencies with an average optical density of 1.67 (black), 0.90 (yellow), 1.39 (cyan) and 1.62 (magenta). These images could not be handwiped or lifted with adhesive tape 60 seconds subsequent to their preparation. EXAMPLE IV There were prepared by a reverse roll process (single side each time), coated transparencies on a Faustel Coater by providing a 'Mylar' substrate (roll form) in a thickness of 100 µm and a coating thereover of an antistatic polymer layer of hydrophilic hydroxyethyl cellulose of Example I, which cellulose was present in a concentration of 3 percent by weight in water. Subsequent to air drying at 100°C the dried 'Mylar' roll had on one side 300 milligrams, 3 µm in thickness, of hydrophilic hydroxyethyl cellulose. The dried hydroxyethyl cellulose layer was further overcoated on the Faustel coater with a toner-receiving layer of the hydrophobic ethylhydroxyethyl cellulose, of Example III, 30 percent by weight and epichlorohydrin/ethylene oxide copolymer of Example II (epichlorohydrin content 65 percent by weight) 70 percent by weight which blend was present in toluene in a concentration of 2 percent by weight. The dried (100°C) layer of the blend in contact with the antistatic polymer layer of hydroxyethyl cellulose had a thickness of 2 µm. Rewinding the coated 'Mylar' on an empty core, the uncoated side was coated first with the hydroxyethyl cellulose from aqueous solution as described above, and then overcoated with a toner-receiving polymer layer of the epichlorohydrin/ethylene oxide (epichlorohydrin content 65 percent by weight) 50 percent by weight and the hydrophobic ethylhydroxyethyl cellulose 50 percent by weight in toluene. The coated 'Mylar' roll was cut into sheet form and 10 sheets were fed into Xerox 1005™ imaging apparatus and ten sheets were fed into the Xerox 1025™ black-only imaging apparatus. The toner-receiving layer on one surface of the substrate, containing 70 percent by weight of epichlorohydrin/ethylene oxide copolymer, was imaged with the Xerox 1005™, and images on the transparencies of an average density of 1.7 (black), 0.95 (yellow), 1.50 (cyan) and 1.48 (magenta) were obtained. The toner-receiving layer on the other surface of the substrate having a 50:50 blend of ethyl hydroxyethyl cellulose and epichlorohydrin/ethylene oxide copolymer (epichlorohydrin content 65 percent by weight), was imaged with the Xerox 1025™ and there resulted images with an average optical density of 1.28 (black). These images could not be handwiped or lifted with adhesive tape 60 seconds subsequent to their preparation. EXAMPLE V There were prepared by solvent extrusion (single side coated each time) coated transparencies on a Faustel coater by providing a 'Mylar' substrate (roll form) in a thickness of 100 µm and coating thereover a hydrophilic antistatic polymer layer of cationic cellulose (Celquat H-1 00, National Starch), which cellulose was present in a concentration of 3 percent by weight in water. Subsequent to air drying at 1 00°C, the dried Mylar had on one side 300 milligrams of the cationic cellulose. This cellulose layer was then overcoated with a toner-receiving polymer layer of ethylhydroxyethyl cellulose of Example II, 30 percent by weight, with the epichlorohydrin/ethylene oxide of Example II, (65 percent epichlorohydrin) 70 percent by weight, which blend was present in a concentration of 2 percent by weight in toluene. Repeating the procedures of Example IV, the other surface of the substrate was coated first with the cationic cellulose Celquat H-100, and then overcoated with a toner-receiving layer of ethyl hydroxy ethyl cellulose 60 percent by weight, and the ethylene/vinyl acetate adhesive (vinyl acetate content, 40 percent by weight) 40 percent by weight, which blend was present in a concentration of 2 percent by weight in toluene. After drying these coatings, the roll was cut into 20 sheets, and 10 of these were fed into the Xerox 1005™ color imaging apparatus, and ten sheets were fed into the Xerox 1025™ imaging apparatus containing a carbon black toner composition The average optical density of the 1005™ images present on the epichlorohydrin/ethylene oxide blended with ethyl hydroxy ethyl cellulose coating layer transparency was 1.70 (black), 0.95 (yellow), 1.50 (cyan) and 1.45 (magenta). The average optical density of 1025™ images was 1.25. These images could not be handwiped or lifted with adhesive tape 60 seconds subsequent to their preparation.

Claims: A transparent substrate material comprised of a support substrate base, an antistatic polymer layer coated on at least one surface of the substrate and comprised of hydrophilic cellulosic components, and a toner-receiving polymer layer coated on the or each surface of the antistatic layer, which polymer is comprised of hydrophobic cellulose ethers, hydrophobic cellulose esters, or mixtures thereof, and wherein the toner-receiving layer contains adhesive components. A material in accordance with claim 1, wherein the antistatic layer cellulosic components are comprised of (1) hydroxyethyl cellulose, (2) ethylhydroxyethyl cellulose, (3) sodium carboxymethyl cellulose, (4) hydroxypropyl trimethyl ammonium chloride, quaternized hydroxyethyl cellulose or (5) quaternized diethyl ammonium chloride hydroxyethyl cellulose. A material in accordance with claim 1 or 2, wherein the hydrophobic cellulosic ethers are comprised of ethylhydroxyethyl cellulose or ethyl cellulose; and the cellulosic esters are comprised of cellulose acetate, cellulose acetate butyrate, cellulose acetate hydrogen phthalate, cellulose acetate phthalate or, hydroxypropyl methyl cellulose phthalate. A material in accordance with any preceding claim, wherein the adhesive components are comprised of epichlorohydrin/ethylene oxide copolymer with an epichlorohydrin content of from 25 to 75 percent by weight; ethylene/vinyl acetate with a vinyl acetate content of from 40 to 70 percent by weight, poly(chloroprene), poly(caprolactone), or a styrene-butadiene copolymer with a butadiene content of from 10 to 80 percent by weight. A material in accordance with claims 3 and 4, wherein the toner-receiving layer is comprised of from 10 to 90 percent by weight of hydrophobic ethylhydroxyethyl cellulose, and from 90 to 10 percent by weight of an epichlorohydrin/ethylene oxide copolymer adhesive. A material in accordance with any preceding claim, wherein the support substrate is of cellulose acetate, poly(sulfone), poly(propylene), poly(vinyl chloride) or poly(ethylene terephthalate). A material in accordance with any preceding claim, wherein the substrate is of a thickness of 75 to 125 µm, the antistatic layer is of a thickness of from 2 to µm and the toner-receiving layer is of a thickness of from 1 to 5 µm. A material in accordance with any preceding claim, wherein the toner-receiving layer contains fillers. A material in accordance with any preceding claim, wherein the toner-receiving layer on one surface of the material is of a different composition from that of the toner-receiving layer on the other surface thereof. A material in accordance with any preceding claim, wherein the antistatic layers on both surfaces of the support substrate are of different compositions.

Inventors: MALHOTRA SHADI L, MALHOTRA, SHADI L.
Applicants: XEROX CORP, XEROX CORPORATION
Application year: 1990
Main classification: G03G7
IPC codes: B32B7, G03G7, B32B23, H05F1