Photographic elements containing matte particles of bimodal size distribution

Abstract: An imaging element comprising a support, at least one hydrophilic light-sensitive layer and at least one protective overcoat layer containing a binder and permanent matte particles, the permanent matte particles having a size distribution of a first mode and a second mode, the first mode being organic particles having a median size of from 0.2 to 1.2 micrometers in a coating weight of from 10 to 200 mg/m 2 , the said second mode being particles having a mean particle size of from 1.5 to 10 micrometers in a coating weight of from 25 to 150 mg/m 2 , the total coating weight of particles of the first and second modes being greater than 100 mg/m 2 .

Description: FIELD OF THE INVENTION This invention relates to imaging elements and more particularly to photographic imaging elements with improved blocking resistance, favorable storage and handling characteristics in cartridges after processing, improved image quality in printing and projecting, enhanced ferrotyping protection and improved resistance to scratch and abrasion. BACKGROUND OF THE INVENTION It is conventional to incorporate finely powdered grains or matting agents into the protective layer of a photographic element to increase the surface roughness so as to reduce self-adhering of the material, to reduce sticking of the material to manufacturing and processing devices, to improve the antistatic properties of the material, and to improve the vacuum adhesiveness of the material in contact exposure to prevent Newton's rings. The matting agents are commonly very small particles of organic or inorganic materials, such as silicone dioxide, magnesium oxide, titanium dioxide, calcium carbonate, poly(methyl methacrylate), poly(vinyltoluene), poly(methyl methacrylate-co-methacrylic acid), and so on. This "matting" of the surface layer suffers, however, from various disadvantages. For example, it reduces the transparency of the photographic elements after processing and increases the graininess of the picture. This limits the amount and size of matte which can be incorporated into the protective overcoat. Many attempts therefore have been made to find processing removable polymer particles (soluble matte) which can be removed from the surface during processing, for example, in high pH processing solutions. The high concentration of processing removable matte is needed especially when the photographic elements are used at relatively high levels of moisture and at relatively elevated temperature of from 30 to 40°C. It is also needed to prevent adverse photographic effects, such as desensitization or hypersensitization, when the materials are rolled up. However, the use of a high level of processing removable matte does not prevent photographic elements from ferrotyping or blocking after processing. This has become important in recent years as more and more processed photographic elements are stored or housed in cartridges with which they come into direct contact. Moreover, the use in the protective overcoat of a higher level of processing removable polymer mattes which contain carboxylic acid groups tends to cause self damage of the photographic elements by scratching or abrading the surface on the opposite side, and to cause damage to manufacturing and finishing apparatus. Therefore, it is desirable to use a minimum amount of processing removable matte in the protective layers of photographic elements even for ferrotyping protection in the raw (unprocessed) state. In recent years, rapid processing and high temperature drying after processing have become common practice for photographic materials. Films dried at high temperatures, for example 60°C (harsh drying), tend to be more prone to ferrotyping which results from close contact, especially under elevated humidity and temperature. When ferrotyping is sufficiently severe, the resulting prints are unacceptable. Films dried at lower temperatures, for example 40°C (mild drying), tend to show much less ferrotyping. The reason for this difference is not understood. The reintroduction of processed photographic elements into thrust cassettes also causes scratches and abrasion marks on the side opposite to that containing matte particles. Such scratches and abrasion marks deface the photographic image quality and therefore very expensive retouching is often required. Recently, significant advancements have been made with regard to the methods of preparing photographic material. For example, the speed of coating, finishing, and cutting has been increased. These improvements have also resulted in a significant increase in the amount of scratches and abrasion marks on the side opposite to that containing matte particles. Moreover, recent improvements have also been made to the image quality of the photographic materials in regard to the nonuniformity, or graininess, of the resulting prints by improving the imaging layer structures (e.g., developed grains, dispersions, etc.). The graininess is generally measured by RMS granularity, wherein the variability of the density in a specific region of uniform exposure is measured. The definition of statistical variance in density can be found, for example, in "Introduction to Photographic Theory - The Silver Halide Process", Carroll, B.H., Higgins, G.C., James, T.H., published by John Wiley & Sons, 1980. The overall variance in density σ(d) is given by σ 2 (d) = σ 2 (image) + σ 2 (matte) + σ 2 (test) + error where σ 2 (image) accounts for the density variation due to image structures and σ 2 (matte) accounts for the density variation due to the presence of matte particles. As reductions in the σ 2 (image) have been made in recent years, the impact of the σ 2 (matte) has become even more critical. It has been common to reduce the impact of the σ 2 (matte) by reducing the specularity of the printing method, but this technique can limit the productivity of photographic printers. In addition, recent storage and display devices, such as PhotoCD and other means of electronic display all make use of specular transmission of the photographic element. PROBLEM TO BE SOLVED BY THE INVENTION There is a need for a photographic element with good ferrotyping performance both before and after processing, that enables the element to be used under harsh application conditions with superior performance. Also, there is clearly a need to reduce the magnitude and impact of σ 2 (matte) on image quality without sacrificing the ferrotyping protection offered by matting agents on the post process photographic element. SUMMARY OF THE INVENTION In accordance with the present invention, an imaging element comprises a support, at least one hydrophilic light-sensitive layer, and at least one protective overcoat layer, contains a binder and permanent matte particles. The permanent matte particles are composed of a size distribution of a first mode and a second mode, with the first mode being composed of organic particles having a mean particle size of from 0.2 to 1.2 micrometers in a coating weight of 10 to 200 mg/m 2 , and the second mode having a mean particle size of from 1.5 to 10 micrometers in a coating weight of 5 to 150 mg/m 2 , the total coating weight of the particles of the first and second modes being greater than 100 mg/m 2 . In a specific embodiment of the invention, both the first and second modes are polymethyl methacrylate. ADVANTAGEOUS EFFECTS OF THE INVENTION The photographic elements in accordance with this invention demonstrate good image quality and improved matte cinch scratches and abrasions, improved ferrotyping and blocking protection at high temperatures and humidities, reduced surface haze and print graininess, and favorable handling and storage in cartridges after processing. DETAILED DESCRIPTION OF THE INVENTION This invention contemplates imaging elements having a support, at least one light-sensitive layer, generally silver halide, and a protective layer located further from the support than the light-sensitive layer. The protective layer includes permanent matte particles having a heterogeneous size distribution in a particular bimodal distribution. The measurement and interpretation of particles with such bimodal size distribution have been described in detail by, for example, R. R. Irani and C. F. Callis (Particle Size: Measurement, Interpretation, and Application, John Wiley & Sons, Inc. 1963), and J. M. Dallavalle, C. Orr, and H. G. Blocker (Ind. Eng. Chem., 43, 1377, (1951)). In a particular embodiment, the matte particles of both modes are polymethylmethacrylate, and preferably comprise greater than 80 mole percent of methyl methacrylate in a hydrophilic binder. The imaging elements in accordance with this invention can be applied to any suitable support such as, for example, those described in Section XV of Research Disclosure No. 36544, September 1994, and in U.S. Patent 5,284,714, incorporated herein by reference. It is apparent to those skilled in the art that the photographic element described herein may be exposed in either a conventional reloadable camera or a prepackaged photographic unit, also known as a Single Use Camera. While the invention is applicable to all types of imaging elements, such as, thermal imaging elements, photothermographic imaging elements, vesicular elements, and the like, the invention is particularly applicable for use in photographic elements which, for the purpose of simplicity of explanation, will be referred to hereinafter. Matte particles of the present invention can be of any shape. The mean diameter of a particle is defined as the diameter of a spherical particle of identical volume. In some embodiments, it may be preferable to have matte particles that are in the form of spherical beads having diameters in the size ranges described above. Organic polymeric materials which may comprise matte particles of the first mode include cellulose esters, cellulose ethers, starches, addition-type polymers and interpolymers prepared from ethylenically unsaturated monomers such as acrylates including acrylic acid, methacrylates including methacrylic acid, acrylamides and methacrylate amides, itaconic acid and its half esters and diesters, styrenes including substituted styrenes, acrylonitriles, and methacrylonitriles, vinyl acetates, vinyl ethers, vinyl and vinylidene halides and olefins. In addition, crosslinking and grafting monomers such as 1,4-butyleneglycol methacrylate, trimethylolpropane triacetate, allyl methacrylate, diallyl phthalate, divinyl benzene, and the like may be used. Other polymers that may comprise matting particles of the first mode include condensation polymers such as polyurethanes, polyesters, polyamides, epoxies, and the like. The particles of the first mode have a mean particle size of from 0.2 to 1.2 µm, preferably from 0.5 to 1.2 µm and most preferably 0.7 to 1.2 µm. The particles of the first mode are present in the protective layer in a coverage of 10 to 200 mg/m 2 , preferably 30 to 170 mg/m 2 , and most preferably 50 to 150 mg/m 2 . The matte particles of the first mode can be prepared by pulverizing and classifying organic compounds, by emulsion, suspension, or dispersion polymerization of organic monomers, by spray drying of a solution containing organic compounds, and by a polymer suspension technique which consists of dissolving an organic material in, for example, a water immiscible solvent, dispersing the solution as fine liquid droplets in aqueous solution, and removing the solvent by evaporation or other suitable techniques. The bulk, emulsion, dispersion, and suspension polymerization procedures are well known to those skilled in the polymer art and are taught in such textbooks such as G. Odian in Principles of Polymerization, 2nd Ed., Wiley (1981), and W. P. Sorenson and T. Campbell in Preparation Method of Polymer Chemistry, 2nd Ed., Wiley (1968). Suitable stabilizers or dispersing aids can be used in these processes. For example, steric stabilizer, when used in the aqueous media, may include poly(vinyl alcohol), poly(acrylic acid) and its salt, poly(methacrylic acid) and its salt, poly(vinyl pyrrolidone), styrene-maleic acid copolymers, vinyl methyl ether-maleic acid copolymers, sodium alginate, water soluble cellulose derivatives and the like. Suitable materials for matte particles of the second mode include both organic and inorganic materials, such as inorganic particles including silicone dioxide, barium sulfate, desensitized silver halide, zinc particles, calcium carbonate, and the like; organic polymeric particles, such as, cellulose esters, cellulose ethers, starches; addition-type polymers and interpolymers prepared from ethylenically unsaturated monomers such as acrylates including acrylic acid, methacrylates including methacrylic acid, acrylamides and methacrylate amides, itaconic acid and its half esters and diesters, styrenes including substituted styrenes, acrylonitriles, and methacrylonitriles, vinyl acetates, vinyl ethers, vinyl and vinylidene halides and olefins. In addition, crosslinking and grafting monomers such as 1,4-butyleneglycol methacrylate, trimethylolpropane triacetate, allyl methacrylate, diallyl phthalate, divinyl benzene, and the like may be used. Other polymers that may comprise matting particles of the second mode include condensation polymers such as polyurethanes, polyesters, polyamides, epoxies, and the like. Particles useful for matte particles of the second mode are described in further detail Research Disclosure No. 308, published December 1989, pages 1008-1009. The particles of the second mode have a mean particle size of from 1.5 to 10 µm, preferably from 1.5 to 5 µm, and most preferably from 1.5 to 3 µm. The particles of the second mode are present in the protective layer in a range of from 25 to 150 mg/m 2 , preferably from 25 to 120 mg/m 2 , and most preferably from 50 to 100 mg/m 2 . As indicated above, in a particular embodiment, both the particles of the first mode and second mode are polymethylmethacrylate having the physical characteristics set forth above. When both modes of the permanent matte particles of the present invention are polymethylmethacrylate preferably contain greater than 80 mole percent methyl methacrylate. For example, the matte particles can be heterogeneous, containing other addition polymers, condensation polymers, inorganic fillers, and the like. Inorganic fillers, for example, include silicon dioxide, tin oxide, antimony doped tin oxide, aluminum oxide, iron oxide, metal antimonates, and the like. Suitable condensation polymers include polyesters, polyurethanes, polycarbonates, polyamides, polyanalines, polythiophenes, and the like. Suitable polyaddition polymers other than methyl methacrylate include any of those made from the following monomers including acrylic monomers, including acrylic acid and their alkyl esters, such as, ethyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, n-octyl acrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, nonyl acrylate, benzyl methacrylate; the hydroxyalkyl esters of the same acids, such as, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; and the nitrile and amides of the same acids, such as, acrylonitrile, methacrylonitrile, acrylamide and methacrylamide; vinyl monomers, such as, vinyl acetate, vinyl propionate, vinylidene chloride, vinyl chloride, and vinyl aromatic compounds such as styrene, t-butyl styrene and vinyl toluene and the like. Other comonomers which may be used in combination with any of the foregoing monomers include dialkyl maleates, dialkyl itaconates, dialkyl methylene-malonates, isoprene, and butadiene. In addition, crosslinking comonomers can be used to crosslink the polymer particles of the present invention to effectively increase the glass transition temperature of the particles. These are monomers which are polyfunctional with respect to the polymerization reaction, and include esters of unsaturated monohydric alcohols with unsaturated monocarboxylic acids, such as, allyl methacrylate, allyl acrylate, butenyl acrylate, undecenyl acrylate, undecenyl methacrylate, vinyl acrylate, and vinyl methacrylate; dienes such as butadiene and isoprene; esters of saturated glycols or diols with unsaturated monocarboxylic acids, such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol dimethacrylate; and polyfunctional aromatic compounds such as divinyl benzene. The permanent matte particles also may include mixtures of particles wherein 80 percent of the particles present in the mixture are polymethylmethacrylate and up to 20 percent of the particles can include any of the materials heretofore mentioned. The permanent matte particles may also be copolymers of greater than 80 mole percent of methyl methacrylate and up to 20 mole percent of any other ethylenically unsaturated monomers, such as, those specifically set forth above with respect to heterogeneous particles. It should be understood that the composition of the methyl methacrylate particles of the first mode and the composition of the methyl methacrylate particles of the second mode need not be the same. Preferably, the permanent matte particles of the present invention are a copolymer of methyl methacrylate and another ethylenically unsaturated monomer. More preferably, the copolymer is at least 90 mole percent methyl methacrylate. Most preferably, the matte particles are 100 mole percent methyl methacrylate. In the present invention, the permanent matte particles are added to a light-sensitive protective layer. The protective layer may comprise two or more layers. The matte particles of the present invention can be added to any one of these layers. However, it is preferred to add them to the uppermost layer, with the overall coated amount being above 100 mg/m 2 . It is further preferred that the thickness of the uppermost layer be less than the mean particle size of the second mode. The protective layer or layers may be disposed over the light-sensitive emulsion layers or on the opposite side of the support than the emulsion layers. When either of particles is polymeric in nature, it may include reactive functional groups which form covalent bonds with binders by intermolecular crosslinking or by reaction with a crosslinking agent (i.e., a hardener). Suitable reactive functional groups include: hydroxyl, carboxyl, carbodiimide, epoxide, aziridine, vinyl sulfone, sulfinic acid, active methylene, amino, amide, allyl, and the like. There is no particular restriction on the amount of reactive groups present, but their concentrations are preferably in the range of from 0.5 to 10 weight percent. The particle surface may be surrounded with a layer of colloidal inorganic particles as described in U.S. Patent No. 5,288,598, or a layer of colloidal polymer latex particles which have affinity with suitable binders as described in U.S. Patent No. 5,279,934, or a layer of gelatin as described in U.S. Patent No. 4,855,219. A preferred method of making matte particles used in accordance this invention is set forth in U.S. Patent Application 08/330,406, filed October 28, 1994, entitled "The Process for Making Photographic Polymeric Matte Bead Particles", assigned to the same assignee as this application. Both types of matte particles useful in the present invention can contain porous structures. The surface area of the matting agent varies but is preferably above 400 m 2 /g. The pore size in terms of average diameter can be any size but preferably less than 200 A. Known methods which can be used for the preparation of the porous matting agents useful in the present invention have been described, for example, in U.S. Patent Nos. 2,459,903; 2,505,895; 2,462,798; 3,066,092; 1,665,264; 2,469,314; 2,071,987; and 2,685,569. Both types of matting agents can also be dyed or pigmented as illustrated in U.S. Patent No. 4,171,737. Processing removable mattes can be used in the practice of this invention to further enhance the resistance of the pre-processed element to ferrotyping and blocking. Such mattes include particles of, for example, copolymers of alkyl (meth)acrylates and methacrylic acid, or acrylic acid, or itaconic acid, copolymers of alkyl (meth)acrylates and maleic monoesters or monoamides, copolymers of styrene or vinyl toluene and α,β-unsaturated mono- or di-carboxylic acids, or dicarboxylic monoesters or monoamides. Graft copolymers containing maleic anhydride or methacrylic acid, and dicarboxylic acid mono-ester of a cellulose derivative, such as phthalate and hexahydrophthalate of methyl cellulose, hydroxyethyl cellulose, or hydroxypropylomethyl cellulose. Such processing soluble mattes are described in further detail in U.S. Patent Nos. 2,992,101; 3,767,448; 4,094,848; 4,447,525; and 4,524,131. Any suitable binder can be used in practice of the present invention including hydrophilic colloids, such as, gelatin as well as hydrophobic polymer resin binders. While the actual amount of binder coated in order to achieve desirable surface physical properties will vary depending on the size and amount of each type of matte particle, the binder is preferably coated at less than about 3 g/m 2 to provide surface roughness and greater than 0.2 g/m 2 to provide effective adhesion of the matte particles to the surface of the element. Suitable hydrophilic binders include both naturally occurring substances such as proteins, protein derivatives, cellulose derivatives (e.g., cellulose esters), gelatins and gelatin derivatives, polysaccharides, casein, and the like, and synthetic water permeable colloids such as poly(vinyl lactams), acrylamide polymers, poly(vinyl alcohol) and its derivatives, hydrolyzed polyvinyl acetates, polymers of alkyl and sulfoalkyl acrylates and methacrylates, polyamides, polyvinyl pyrridine, acrylic acid polymers, maleic anhydride copolymers, polyalkylene oxide, methacrylamide copolymers, polyvinyl oxazolidinones, maleic acid copolymers, vinyl amine copolymers, methacrylic acid copolymers, acryloyloxyalkyl acrylate and methacrylates, vinyl imidazole copolymers, vinyl sulfide copolymers, homopolymer or copolymers containing styrene sulfonic acid, and the like. Useful resin binders include polyurethane (e.g., Neorez R960 sold by Zeneca), cellulose acetates (e.g., cellulose diacetate, cellulose acetate butyrate, cellulose acetate propionate), poly(methyl methacrylate), polyesters (e.g., Vitel R sold by Goodyear Tire & Rubber Co.), polyamides (e.g., Unirez sold by Union Camp, Vesamide sold by General Electric Co.), polycarbonates (e.g., Makrolon sold by Mobay Chemical Co., Lexan sold by General Electric Co.), polyvinyl acetate, and the like. The binder should be chosen so that it effectively adheres the matte particles to the surface of the element. For crosslinkable binders such as gelatin and polyurethane, the binder is preferably cross-linked so as to provide a high degree of adhesion. Crosslinking agents or hardeners which may effectively be used in the coating compositions of the present invention include aldehydes, epoxy compounds, polyfunctional aziridines, vinyl sulfones, methoxyalkyl melamines, triazines, polyisocyanates, dioxane derivatives such as dihydroxydioxane, carbodiimides, chrome alum, zirconium sulfate, and the like. Any lubricant can be used in the outermost layer of the present invention. Typical lubricants include (1) silicone based materials disclosed, for example, in U.S. Patent Nos. 3,489,567; 3,080,317; 3,042,522; 4,004,927; and 4,047,958, and in British Patent Nos. 955,061 and 1,143,118; (2) higher fatty acids and derivatives, higher alcohols and derivatives, metal salts of higher fatty acids, higher fatty acid esters, higher fatty acid amides, polyhydric alcohol esters of higher fatty acids, etc., disclosed in U.S. Patent Nos. 2,454,043; 2,732,305; 2,976,148; 3,206,311; 3,933,516; 2,588,765; 3,121,060; 3,502,473; 3,042,222; and 4,427,964; in-British Patent Nos. 1,263,722; 1,198,387; 1,430,997; 1,466,304; 1,320,757; 1,320,565; and 1,320,756; and in German Patent Nos. 1,284,295 and 1,284,294; (3) liquid paraffin and paraffin or wax like materials such as carnauba wax, natural and synthetic waxes, petroleum waxes, mineral waxes and the like; (4) perfluoro- or fluoro- or fluorochloro-containing materials, which include poly(tetrafluoroethlyene), poly(trifluorochloroethylene), poly(vinylidene fluoride), poly(trifluorochloroethylene-co-vinyl chloride), poly(meth)acrylates or poly(meth)acrylamides containing perfluoroalkyl side groups, and the like. Lubricants useful in the present invention are described in further detail in Research Disclosure No.308, published Dec. 1989, page 1006. The protective layer useful in the practice of the invention may optionally contain surface active agents, charge control agents, antistatic agents, thickeners, ultraviolet ray absorbers, processing removable dyes, high boiling point solvents, silver halide particles, colloidal inorganic particles, magnetic recording particles, slip agents, additional matting agents, polymer latexes, and various other additives. The protective layer useful in the practice of the invention can be applied in any of a number of well-known techniques, such as dip coating, rod coating, blade coating, air knife coating, gravure coating, and reverse roll coating, extrusion coating, slide coating, curtain coating, and the like. The matte particles and the binder are preferably mixed together in a liquid medium to form a coating composition. The liquid medium may be a medium such as water or other aqueous solution in which hydrophilic colloids are dispersed with or without the presence of surfactants, or it may be a solvent such as an organic solvent in which the resin binder (but not the matte particles) is dissolved. After coating, the protective layer is generally dried by simple evaporation, which may be accelerated by known techniques such as convection heating. Known coating and drying methods are described in further detail in Research Disclosure No. 308, Published Dec. 1989, pages 1007 to 1008. The photographic element of the present invention can contain at least one electrically conductive layer, which can be either a surface protective layer or a sub layer. The surface resistivity of at least one side of the support is preferably less than 1x10 12 Ω/square, more preferably less than 1x10 11 Ω/square at 25 °C and 20 percent relative humidity. To lower the surface resistivity, a preferred method is to incorporate at least one type of electrically conductive material in the electrically conductive layer. Such materials include both conductive metal oxides and conductive polymers or oligomeric compounds. Such materials have been described in detail in, for example, U.S. Patent Nos. 4,203,769; 4,237,194; 4,272,616; 4,542,095; 4,582,781; 4,610,955; 4,916,011; and 5,340,676. The present invention is also directed to a single-use camera having incorporated therein a photographic element as described above. Single-use cameras are known in the art under various names: film with lens, photosensitive material package unit, box camera and photographic film package. Other names are also used, but regardless of the name, each shares a number of common characteristics. Each is essentially a photographic product (camera) provided with an exposure function and preloaded with a photographic material. The photographic product comprises an inner camera shell loaded with the photographic material, a lens opening and lens, and an outer wrapping(s) of some sort. The photographic materials are exposed in camera, and then the product is sent to the developer who removes the photographic material and develop it. Return of the product to the consumer does not normally occur. Single-use cameras and their methods of manufacture and use are described in U.S. Patent Nos. 4,801,957; 4,901,097; 4,866,459; 4,849,325; 4,751,536; 4,827,298; European Patent Applications 460,400; 533,785; 537,225; all of which are incorporated herein by reference. The invention is illustrated by the following examples: Examples 1 to 8 A series of photographic elements are prepared as follows: A cellulose triacetate film support having an antihalation layer on one side and an antistatic backing layer on the other side (as described below) is coated on the antihalation layer with the following image forming layers in sequence (U.S. Patent No. 5,288,598): a slow cyan dye-forming layer, a fast cyan dye-forming layer, an interlayer, a slow magenta dye-forming layer, a fast magenta dye-forming layer, an interlayer, a slow yellow dye-forming layer, a fast yellow dye-forming layer, and a UV layer. The antistatic backing layer is coated with 143 mg/m 2 cellulose acetate, 72 mg/m 2 poly(vinyl benzyl chloride-co-ethylene glycol diacrylate) quanteranized with triethyl amine, and 21.5 mg/m 2 carnauba wax. A protective layer containing gelatin binder is coated on the top of the UV layer and has a composition listed in Table I. COMPOSITION OF THE PROTECTIVE LAYER a. Gelatin, Type IV 888 mg/m 2 b. Silicone lube, DC-200 (Dow Corning) 40.1 mg/m 2 c. Fluorad FC-134 3.9 mg/m 2 d. Aerosol OT 21.5 mg/m 2 e. Surfactant Olin 10G 27.2 mg/m 2 f. Matte 2, Poly(vinyl toluene-co-divinyl benzene) 80:20 ratio, 1.5 µm in Table 2 g. Matte 1, Poly(vinyl toluene-co-divinyl benzene) 80:20 ratio, 0.45 µm in Table 2 Ferrotyping Performance for Examples 1-17 The ferrotyping performance is evaluated in the following manner: 12" by 35 mm strips of film, either raw or processed, and leader are conditioned to desired RH at 70°F. for 17 hours. The leader is then wound under 24 oz. tension onto a reel and pairs of test strips are wound between laps of the leader. The reel is then packaged in a vapor proof bag and held at the desired temperature for 1 or 3 days. Following the hold, the leader is unwounded, the strips are removed and visually evaluated for ferrotyping. The following scale is used: Value % of Area Showing Ferrotyping A 0 B >0 to <5 C 5 to <20 D 20 to <50 E 50 to 100 The graininess of a photographic picture is caused by the developed grain and dispersions and in particular matting agent in the protective layers. The Root Mean Square (RMS) Granularity is evaluated by the method described in ANSI Ph 2.40 (1985) entitled "Root Mean Square (RMS) Granularity of Film (Images on One Side Only)-Method for Measurement". The test results are reported in Table II. Example No. Matte 2, 1.5 µm mg/m 2 Matte 1, 0.45 µm mg/m 2 Insert Ferrotyping 120 °F./70% RH/2 days (48,9°C) RMS (Graininess) Raw Processed Near Core Near out 1 (Comp.) 0 80.7 E E E -1 2 (Comp.) 80.7 0 C C D 2.0 3 (Inv.) 80.7 80.7 B B C 1.5 4 (Inv.) 80.7 161.5 B B C 2.5 5 (Inv.) 33.4 114.1 C C D 0.5 6 (Inv.) 114.1 33.4 B B C 2.5 7 (Inv.) 114.1 114.1 B B C 2.5 8 (Comp.) 161.5 80.7 B B C 4.0 As can be seen from the Table, the samples according to the present invention result in a significant improvement in the ferrotyping properties both before and after processing with acceptable printing RMS granularity values. Both present invention Example 4 and Comparison Example 8 contain the same amount of total matting agents (i.e. 242.2 mg/m 2 ), and have similar ferrotyping properties. However, comparison Example 8 indicates that the use of a higher level of larger permanent matte (>150 mg/m 2 ) leads to unacceptable printing RMS granularity. Examples 9 to 17 The photographic elements in these examples are prepared as described above except the protective layer composition is as set forth in Table III. COMPOSITION OF THE PROTECTIVE LAYER a. Gelatin, Type IV 888 mg/m 2 b. Silicone lube, DC-200 (Dow Corning) 39.1 mg/m 2 c. Fluorad FC-134 3.9 mg/m 2 d. Aerosol OT 21.5 mg/m 2 e. Surfactant Olin 10 G 27.3 mg/m 2 f. Matte 2, Poly(vinyl toluene-co-divinyl benzene) 80:20 ratio, 1.5 µm in Table 4 g. Matte 1, Poly(vinyl toluene-co-divinyl benzene) 80:20 ratio, 0.75 µm in Table 4 h. Matte 3, Poly(methyl methacrylate-co-methacrylic acid) 45:55, 2.7 µm 107.6 mg/m 2 The coating ferrotyping performance and printing RMS granularity are evaluated in the same manner as described above, and the results are listed in Table IV. The results, compiled in Table IV, demonstrate excellent ferrotyping protection properties of the samples according to the present invention in combination with the use of processing removable matte (Matte 3) in the protective layers. For example, comparative Example 9 contains only soluble matte and larger permanent matte, and shows inferior ferrotyping protections both before and after processing. The use of matte combinations according to the present invention results in a significant improvement on ferrotyping performance (e.g., Example 12) without any significant change in the film RMS printing granularity. Example No. Matte 2 mg/m 2 Matte 1 mg/m 2 Matte 3 mg/m 2 Insert Ferrotyping RMS (Graininess) Raw Processed 100°F (37,8°C) 70%RH 100°F/80%RH 120°F (48,9°C) 70%RH 120°F/70%RH 17 Hrs. 17 Hrs. 3 Days 3 Days 9(Comp.) 53.8 0 107.6 B E C E 1 10(Inv.) 53.8 53.8 107.6 B C B D 1 11(Inv.) 53.8 107.6 107.6 B C B D 1 12(Inv.) 53.8 161.5 107.6 B B B C 1 13(Inv.) 26.9 161.5 107.6 B B B C 0 14(Comp.) 80.7 0 107.6 B D C D 1 15(Inv.) 80.7 53.8 107.6 B C B D 1.5 16(Inv.) 80.7 107.6 107.6 B C B C 1.5 17(Inv.) 80.7 161.5 107.6 B B B C 1.5 The types and sizes of the matte particles used in the Examples 18 and 19 are listed in Table V: MATTE PARTICLES Particle No. Composition Mean Particle Size (µm) P-1 Poly(methyl methacrylate) 0.8 P-2 Poly(methyl methacrylate) 1.7 P-3 Poly(methyl methacrylate) 2.4 P-4 Poly(methyl methacrylate-co-methacrylic acid) 45/55 3.0 A series of photographic elements are prepared as follows: A poly(ethylene naphthalate) support having an antihalation layer on one side and an antistatic layer overcoated with a magnetic recording layer on the other side is coated on the antihalation layer with the following imaging forming layer in sequence. Interlayer: This layer comprises 2,5-di-t-octyl-1,4-dihydroxy benzene (0.075 g/m 2 ), tri(2-ethylhexyl)phosphate (0.113 g/m 2 ), and gelatin (0.86 g/m 2 ). Slow Cyan Dye-forming Layer: This layer comprises a red sensitive silver bromoiodide emulsion (3.3 mole percent iodide) (0.324 µm grain size) (0.387 g/m 2 silver), compound CC-1 (0.355 g/m 2 ), IR-4 (0.011 g/m 2 ), B-1 (0.075 g/m 2 ), S-2 (0.377 g/m 2 ), S-3 (0.098 g/m 2 ), and gelatin (1.64 g/m 2 ). Mid Cyan Dye-forming Layer: This layer comprises a blend of a red sensitive silver bromoiodide emulsion (3.3 mole percent iodide) (0.488 µm grain size) (0.816 g/m 2 silver) and a red sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (0.98 µm diameter by 0.11 µm thick) (0.215 g/m 2 silver), compound CC-1 (0.183 g/m 2 ), IR-3 (0.054 g/m 2 ), B-1 (0.027 g/m 2 ), CM-1 (0.011 g/m 2 ), S-2 (0.183 g/m 2 ), S-3 (0.035 g/m 2 ), S-5 (0.054 g/m 2 ), and gelatin (1.35 g/m 2 ). Fast Cyan Dye-forming Layer: This layer comprises a red sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (1.10 µm diameter by 0.11 µm thick) (1.08 g/m 2 silver), compound CC-1 (0.161 g/m 2 ), IR-3 (0.038 g/m 2 ), IR-4 (0.038 g/m 2 ), CM-1 (0.032 g/m 2 ), S-2 (0.237 g/m 2 ), S-5 (0.038 g/m 2 ), and gelatin (1.35 g/m 2 ). Interlayer: This layer comprises 2,5-di-t-octyl-1,4-dihydroxy benzene (0.075 g/m 2 ), tri(2-ethylhexyl)phosphate (0.113 g/m 2 ), and gelatin (0.86 g/m 2 ). Slow Magenta Dye-forming Layer: This layer comprises a blend of a green sensitive, tabular grain, silver bromoiodide emulsion (1.5 mole percent iodide) (0.7 µm diameter by 0.112 µm thick) (0.258 g/m 2 Ag), and a green sensitive, tabular grain, silver bromoiodide emulsion (1.3 mole percent iodide) (0.54 µm diameter by 0.086 µm thick) (0.409 g/m 2 Ag), compound M-1 (0.204 g/m 2 ), MM-1 (0.038 g/m 2 ), ST-1 (0.020 g/m 2 ), S-1 (0.26 g/m 2 ), and gelatin (1.18 g/m 2 ). Mid Magenta Dye-forming Layer: This layer comprises a green sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (0.61 µm diameter by 0.12 µm thick) (0.646 g/m 2 Ag), compound M-1 (0.099 g/m 2 ), MM-1 (0.027 g/m 2 ), IR-2 (0.022 g/m 2 ), ST-1 (0.010 g/m 2 ), S-1 (0.143 g/m 2 ), S-2 (0.044 g/m 2 ), and gelatin (1.41 g/m 2 ). Fast Magenta Dye-forming Layer: This layer comprises a green sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (0.98 µm diameter by 0.113 µm thick) (0.699 g/m 2 Ag), compound M-1 (0.052 g/m 2 ), MM-1 (0.032 g/m 2 ), IR-2 (0.022 g/m 2 ), ST-1 (0.005 g/m 2 ), S-1 (0.111 g/m 2 ), S-2 (0.044 g/m 2 ), and gelatin (1.123 g/m 2 ). Yellow Filter Layer: This layer comprises 2,5-di-t-octyl-1,4-dihydroxy benzene (0.075 g/m 2 ), YD-2 (0.108 g/m 2 ), Irganox 1076 sold by Ciba Geigy (0.01g /m 2 ), S-2 (0.121 g/m 2 ) and gelatin (0.861 g/m 2 ). Slow Yellow Dye-forming Layer: This layer comprises a blend of a blue sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (1.4 µm diameter by 0.131 µm thick) (0.161 g/m 2 Ag), a blue sensitive, tabular grain, silver bromoiodide emulsion (1.5 mole percent iodide) (0.85 µm diameter by 0.131 µm thick) (0.0.108 g/m 2 Ag), and a blue sensitive, tabular grain, silver bromoiodide emulsion (1.3 mole percent iodide) (0.54 µm diameter by 0.086 µm thick) (0.161 g/m 2 Ag), compound Y-1 (0.915 g/m 2 ), IR-1 (0.032 g/m 2 ), B-1 (0.0065 g/m 2 ), S-1 (0.489 g/m 2 ), S-3 (0.0084 g/m 2 ), and gelatin (1.668 g/m 2 ). Fast Yellow Dye-forming Layer: This layer comprises a blue sensitive, tabular grain, silver bromoiodide emulsion (4.5 mole percent iodide) (2.3 µm diameter by 0.128 µm thick) (0.43 g/m 2 Ag), compound Y-1 (0.15 g/m 2 ), IR-1 (0.032 g/m 2 ), B-1 (0.0054 g/m 2 ), S-1 (0.091 g/m 2 ), S-3 (0.0070 g/m 2 ), and gelatin (0.753 g/m 2 ). UV Protective Layer: This layer comprises compound UV-1 (0.lllg/m2), W-2 (0.111 g/m 2 )S-4 (0.222 g/m 2 ), silver bromide Lippmann emulsion (0.215 g/m 2 Ag), and gelatin (0.7 g/m 2 ). C 11 H 23 CON(C 2 H 5 ) 2 Hydrophilic Protective Overcoat Layers The protective overcoat layers containing gelatin binder and matting agents listed in Table V are coated on the top of the UV layer and have the following composition: COMPOSITION OF THE PROTECTIVE OVERCOAT LAYER Gelatin, lime processed 888 mg/m 2 Silicone lube, DC-200 (Dow Corning) 40.1 mg/m 2 Fluorad FC-134 (3M Co.) 3.9 mg/m 2 Aerosol OT (American Cyanamide) 21.5 mg/m 2 Surfactant Olin 10G (Olin Corp.) 27.2 mg/m 2 Matte 1 (Table VII) Matte 2 (Table VII) Matte 3 (Table VII) Table VII shows the compositions of the protective overcoat layers of each photographic element prepared. Coating No. Matte 1 Coverage mg/m2 Matte 2 Coverage mg/m2 Matte 3 Coverage mg/m2 Example 18 (Invention) P-2 53.8 P-1 161.4 P-4 107.6 Example 19 (Invention) P-3 53.8 P-1 161.4 P-4 107.6 Evaluation of the RMS Granularity The graininess of a photographic picture is caused by the developed dye clouds. Image silver and light scatter from matting agents in the protective overcoat layers. The Root Mean Square (RMS) Granularity is evaluated by the method described in ANSI Ph 2.40 (1985) entitled "Root Mean Square (RMS) Granularity of Film (Images on One Side Only)-Method for Measurement". By comparing RMS Granularity of the listed samples with a film that contains no matte, the granularity due to the matte is determined. The test results are reported in Table VIII. Evaluation of Ferrotyping Resistance for Examples 18 and 19 A group of six strips of the feature film (raw or processed) are placed in a 80 percent relative humidity (RH) chamber for a minimum of 16 hours. The strips are stacked, sensitized side to unsensitized side and wrapped in foil, placed inside a moisture proof wrap, and sealed. The sealed package is then placed above a flat glass plate and under a brass bar of the same size with weight of 6.89 kgs (15 lbs). The package, with the glass plate and brass bar is then placed in a 37.8°C (100°F) room for 17 hours. After storage, the bag is opened, the top and bottom strips are discarded, and the remaining strips are visually inspected for ferrotyping against the following scale: Value % of area showing ferrotyping A 0 to <5 B 5 to <20 C 20 to <50 D 50 to 100 The testing results are reported in Table VIII. Evaluation of the Matte Cinch Abrasion Five strips each (30.5 cm x 35 mm) of film having the front side matte containing overcoat are conditioned to 21.1°C (70°F) and 50 percent relative humidity for 17 hours. The sample is fastened, with the film backing layer (back side) side up, in a fixture that contains a right angle edge which defines a vertical and horizontal surface. The samples containing the matte protective layer front side are placed over the samples containing the back side so that the front side is in contact with the back side of the affixed sample. A weight is affixed to the vertical surface of the front side sample. The front side samples are drawn in a horizontal direction away from the right angle. The samples are drawn at a weight of 10, 20, 50, 100, and 200 grams. The five samples containing the back side are qualitatively evaluated for resulting scratches under specular light (average): 0 = no scratches, 1 = few scratches, 2 = some scratches, and 3 = many scratches. The description and the testing results are reported in Table VIII. Coating No. Ferrotyping, Raw, 80%RH/37.8 °C Ferrotyping, Processed (Mild) 80%RH/37.8°C Ferrotyping, Processed (Harsh) 80%RH/37.8°C Increase in RMS Granularity Cinch Abrasion Rating Example 18 1 A A 1.5 1 Example 19 1 A A 3 1 Examples 18 and 19 show unexpectedly superior performance in terms of good ferrotyping protection both before and after processing, low RMS granularity values, and superior resistance to matte cinch scratch and abrasion. The photographic processing steps to which the raw film may be subject may include, but are not limited to the following: 1) color developing → bleach-fixing → washing/stabilizing; 2) color developing → bleaching → fixing → washing/stabilizing; 3) color developing → bleaching → bleach-fixing → washing/stabilizing; 4) color developing → stopping → washing → bleaching → washing → fixing → washing/stabilizing; 5) color developing → bleach-fixing → fixing → washing/stabilizing; 6) color developing → bleaching → bleach-fixing → fixing → washing/stabilizing; Among the processing steps indicated above, the steps 1), 2), 3), and 4) are preferably applied. Additionally, each of the steps indicated can be used with multistage applications as described in Hahm, U.S. Pat. No. 4,719,173, with co-current, counter-current, and contraco arrangements for replenishment and operation of the multistage processor. Any photographic processor known to the art can be used to process the photosensitive materials described herein. For instance, large volume processors, and so-called minilab and microlab processors may be used. Particularly advantageous would be the use of Low Volume Thin Tank processors as described in the following references: WO 92/10790; WO 92/17819; WO 93/04404; WO 92/17370; WO 91/19226; WO 91/12567; WO 92/07302; WO 93/00612; WO 92/07301; WO 02/09932; U.S. 5,294,956; EP 559,027; U.S. 5,179,404; EP 559,025; U.S. 5,270,762; EP 559,026; U.S. 5,313,243; U.S. 5,339,131.

Claims: An imaging element comprising a support, at least one hydrophilic light-sensitive layer and at least one protective overcoat layer containing a binder and permanent matte particles, the permanent matte particles having a size distribution of a first mode and a second mode, the first mode being organic particles having a mean size of from 0.2 to 1.2 micrometers in a coating weight of from 10 to 200 mg/m 2 , the second mode being particles having a mean particle size of from 1.5 to 10 micrometers in a coating weight of from 5 to 150 mg/m 2 , the total coating weight of particles of the first and second modes being greater than 100 mg/m 2 . The imaging element of Claim 1 wherein the particles of the first and second modes are polymethylmethacrylate. The imaging element of Claim 1 wherein the coating weight of the particles of the second mode is from 25 to 150 mg/m 2 . The imaging element of Claim 2 wherein the permanent matte particles comprise more than 80 mole percent of methyl methacrylate.

Inventors: FANT ALFRED B, KESTNER MELVIN M, SMITH DENNIS E, STEINMETZ RUDOLF D, VISCONTE GARY W, WANG YONGCAI, FANT, ALFRED B., KESTNER, MELVIN M., SMITH, DENNIS E., STEINMETZ, RUDOLF D., VISCONTE, GARY W., WANG, YONGCAI, Fant, Alfred B., c/o Eastman Kodak Co., Kestner, Melvin M., c/o Eastman Kodak Co., Smith, Dennis E., c/o Eastman Kodak Co., Steinmetz, Rudolf D., c/o Eastman Kodak Co., Visconte, Gary W., c/o Eastman Kodak Co., Wang, Yongcai, c/o Eastman Kodak Co.
Applicants: EASTMAN KODAK CO, EASTMAN KODAK COMPANY
Application year: 1996
Main classification: G03C1
IPC codes: G03C1