JPH11218887A - Photographic element with formed image having protective overcoat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-resistant protective coating film having improved physical properties which can be easily applied on a photographic product having subjected to an image forming process. SOLUTION: This photographic element is already subjected to an image forming process and has a protective overcoat on the image. The protective overcoat is formed in the following processes. First, the photographic element with an image already formed and having at least one photosensitive silver halide emulsion layer is produced. Then an aq. coating liquid is applied on the at least one photosensitive silver halide emulsion layer above described, and the coating liquid is dried to form the protective overcoat. The aq. coating liquid contains a colloid dispersion liquid of first polymer particles having >=25 deg.C glass transition temp. and 5 to 500 nm particle size and second polymer particles having <25 deg.C glass transition temp. and 5 to 500 nm particle size, with the weight ratio of the first polymer particles to the second polymer particles ranging 3:97 to 80:20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to an imaged photographic element having a protective overcoat (a photographic element having an image already formed).

[0002]

BACKGROUND OF THE INVENTION Silver halide photographic elements contain photosensitive silver halide in a hydrophilic emulsion. The silver halide is exposed to light or other actinic radiation, and then the exposed silver halide is developed and reduced to elemental silver to form an image in the element. In color photographic elements, the silver halide is developed by one of several different methods, resulting in the formation of a dye image. In the most common method, an oxidized silver halide developing agent, a by-product of silver halide development, is reacted with a dye-forming compound called a coupler. The silver and unreacted silver halide are then removed from the photographic element, leaving the dye image.

In each case, imaging usually involves liquid treatment using an aqueous solution which must pass through the surface of the element and come into contact with the silver halide and coupler. For example, gelatin and similar natural or synthetic hydrophilic polymers have proven to be excellent binders for silver halide photographic elements. Unfortunately, when gelatin and similar polymers are blended to facilitate contact between the silver halide crystals and the aqueous processing solution,
They are not as tough or resistant to surface wear as desired for those handled in the manner of handling imaged photographic elements. Thus, the imaged element can easily be fingerprinted, scratched or scratched, and swell or deform when in contact with liquids.

It has been attempted for many years to provide gelatin-based photographic protective layers that can protect images from damage by water or aqueous solutions. U.S. Pat. No. 2,173,480 discloses a method of applying a colloidal suspension to a wet film as a final step in photographic processing before drying. The following series of patents discloses a method of solvent coating a protective layer on an image after completion of photographic processing: U.S. Pat. Nos. 2,259,009, 2,331,746.
No. 2,798,004, No. 3,113,867
No. 3,190,197, No. 3,415,670 and No. 3,733,293. Applying UV-polymerizable monomers and oligomers to the processed image followed by radiation exposure to form a crosslinked protective layer is disclosed in U.S. Patent Nos. 4,092,173, 4,171,979, Nos. 4,333,998 and 4,426,431. The major drawbacks of solvent coating and radiation curing are the health and environmental concerns of these chemicals to the coating operator, as well as the instability of coating solutions and their relatively short shelf life. It is. . U.S. Pat. Nos. 3,397,980, 3,697,277
No. 4,999,266 disclose a method of laminating a polymer sheet film as a protective layer on a processed image. U.S. Patent No. 5,447,832, during the photographic processing, in order to retain the antistatic properties of V ₂ O ₅ layer, a water-resistant layer of the protective layer comprising a mixture of a latex of the high Tg and low Tg Disclose use. This protective layer is not applicable to the image forming layer because it adversely affects and interferes with photographic processing. U.S. Pat. No. 2,706,686 discloses a lacquer finish for photographic emulsions,
Its purpose is to impart water and fingerprint resistance by applying a porous layer having a high degree of water penetration to the processing solution to the emulsion before exposure. After the treatment, the lacquer layer is melt-fused into a non-permeable continuous coating. The porous layer is completed by applying a mixture of a lacquer and a removable solid extender (ammonium carbonate) and then sublimating or dissolving the extender during processing. These overcoats are not suitable for the production of modern photographic products, since they are applied as an organic solvent suspension. U.S. Pat. No. 3,443,946 discloses a roughened (mat) scratch protective layer, but is not water-impermeable. U.S. Pat. No. 3,502,501 discloses protection against mechanical damage only; the layer in question must contain primarily hydrophilic polymeric materials and be permeable to water to maintain processability. Must. U.S. Pat. No. 5,179,147 also discloses a layer that is not waterproof.

[0005] US patent application Ser. No. 08 / 698,838 discloses that charged transparent polymer particles are applied to an imaged silver halide element in the presence of an electric field and the particles are coated on the surface of the imaged element. And then fusing the polymer particles to form a protective overcoat. In U.S. patent application Ser. No. 08 / 898,985, a coating liquid containing 30 to 95% by weight of hydrophobic polymer particles having an average particle size of 0.01 to 1 .mu.m and a melting temperature of 55 to 200.degree. A protective overcoat is formed by coating the photosensitive silver halide emulsion layer. The light-sensitive silver halide emulsion layer is developed to obtain an imaged photographic element. The hydrophobic polymer particles are then fused to form a protective overcoat. However, there remains a need for a method of providing a protective overcoat to a photographic element without performing a fusing step.

The temperature and residence time of photographic coating solutions in the drying zone of commercial photographic finishing equipment vary from 50 ° C. to 70 ° C. and from 30 seconds to 2.5 minutes. The actual temperature of the gelatin coating solution during drying is much lower than the set temperature of the dryer due to evaporation of the water. In addition, if consideration is given to the user and the environment, it is necessary that the formulation does not contain volatile organic compounds (VOC). Under these harsh conditions, aqueous colloidal dispersions of water-insoluble polymeric materials appear to be suitable methods for this technique. Water soluble materials will not provide any water resistance.

US Pat. No. 2,719,791 describes the use of aqueous dispersions of organic plastics materials, which upon drying result in water-impermeable coatings. However, when a dispersion of a material having a low Tg (glass transition temperature) (Tg <25 ° C.) is used to obtain a water-resistant protective coating, the surface of the protective coating has an undesired tackiness and may have other physical properties. Properties such as print blocking (adhesion),
It has been found that fingerprint adhesion, dust adsorption, and high tendency to scratch are generally worse. High Tg (Tg> 25
C) With a dispersion of the material, it is not possible to produce a continuous water-resistant layer on the print under said drying conditions. Also, U.S. Pat. No. 2,751,315 describes the use of aqueous dispersions of copolymer materials. The patent states that a low Tg material was unsuitable and that a high Tg polymer was used in combination with an organic solvent to produce a water resistant protective coating. Organic solvents released from the formulation during drying create environmental problems when used in modern photofinishing facilities. U.S. Pat. No. 2,956,877 describes a method for solubilizing processing agents from photographic products and forming a protective coating on the surface of the product by applying a solution to the photographic image. The acid groups of the polymer degrade the water resistance of the final protective layer, and the organic solvents required for the formulation are unsuitable for high volume photofinishing sites.

[0008]

It can be easily applied to an imaged photographic product and then dried under drying conditions common to photographic processing equipment into a continuous layer, There remains a need for a water-resistant, water-resistant protective coating that does not emit volatile organic compounds and has excellent physical handling characteristics.

[0009]

SUMMARY OF THE INVENTION The present invention comprises a support, at least one photosensitive silver halide emulsion layer superimposed on the support, and a protective overcoat located furthest from the support. And an imaged photographic element comprising: The protective overcoat is overlaid on the photosensitive silver halide layer. The protective overcoat has a first polymer particle having a glass transition temperature of 25 ° C. or more and a particle size of 5 nm to 500 nm and a glass transition temperature of less than 25 ° C. and a particle size of 5 nm.
nm to 500 nm of the second polymer particles in a weight ratio of the first polymer particles to the second polymer particles of 3:97 to 80:20. The protective overcoat is applied using an aqueous coating solution.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a volatile organic solvent which, upon completion of photographic processing, is applied to a photographic product and then dried to form a water resistant, scratch resistant and durable overcoat. No material formulation.
The material composition of the present invention is a combination of two colloidal dispersions of a water-insoluble hydrophobic polymer material. At least one of these polymeric materials has a glass transition temperature of 25 ° C. or higher to impart toughness and non-stick surface properties. . The second polymeric material has a glass transition temperature of less than 25 ° C. to form a continuous coating layer under mild drying conditions as used in typical photographic processing equipment. The weight ratio of these two polymer materials is from 3:97 to 80:20. The average particle size of the colloidal dispersion of the polymeric material is between 5 nm and 500 nm.
The dry weight of all materials on the surface of the photographic product is 0.3 g / m ²
６6 g / m ² . Other components commonly used in photographic processing solutions, such as biocides, spreading aids (surfactants) and lubricants, may also be incorporated into the formulation, if desired.
The concentration of the formulation may be from 1 to 50% total solids, based on the desired thickness of the protective layer, machine speed, dryer efficiency, and other factors affecting application to the photographic product. Good.

The colloidal dispersion of the hydrophobic polymer used in the first or second polymer particles of the present invention generally comprises a hydrophobic polymer of any composition that can be stabilized with a water-based medium. Is latex. Such hydrophobic polymers are generally classified as condensation polymers or addition polymers. Examples of the condensation polymer include polyesters, polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyanhydrides, and polymers obtained by combining the above types. Addition polymers include vinyl-type monomers such as allyl compounds, vinyl ethers, vinyl esters, vinyl heterocycles, styrenes, olefins and halogenated olefins, unsaturated acids and these acids. Polymers produced by polymerizing esters, unsaturated nitriles, vinyl alcohols, acrylamides and methacrylamides, vinyl ketones, polyfunctional monomers, or copolymers produced by various combinations of these monomers There is. Such a latex polymer can be produced in an aqueous medium using a well-known free radical emulsion polymerization method, and is a homopolymer produced by one of the monomers or two or more of the monomers. It may be composed of the produced copolymer. Polymers containing monomers that form water-insoluble homopolymers are preferred, and copolymers of such monomers are also preferred. Preferred polymers may also include monomers that provide a water-soluble homopolymer as long as the entire polymer composition is sufficiently water-insoluble to form a latex. The aqueous phase of the latex or colloidal dispersion of the present invention may contain a water-soluble polymer, for example, to control viscosity and flow properties. The aqueous phase may also contain a cationic, anionic, zwitterionic or nonionic type surfactant. A listing of other examples of suitable monomers for addition-type polymers is provided in U.S. Patent No. 5,594,047, which is incorporated herein by reference.

The photographic products of the present invention have the unique characteristics of water resistance, improved scratch resistance and improved heat blocking. In addition, no volatile organic solvents or compounds are released from the formulation. The imaged photographic elements protected by the present invention are derived from silver halide photographic elements, which include black and white elements (e.g., those that form a silver image or a neutral tone image from a mixture of dye-forming couplers). ), A single color element or a multicolor element. Multicolor elements typically contain dye image-forming units sensitive to each of the three primary regions of the spectrum. The imaged elements can be imaged elements that can be viewed by transmission, such as negative film images, reversal film images and movie prints, or they can be imaged elements that can be viewed by reflection. For example, it can be a paper print. Because of the volumes handled for paper and movie prints, they are the preferred imaged photographic elements for use in the present invention.

The photographic element on which the image to be protected is formed can have the structure and components set forth in Research Disclosure 37038. Specific photographic elements are Research Disclosur as color paper elements 1 and 2.
e 37038 at pages 96-98. A typical multicolor photographic element comprises at least one cyan dye-forming coupler in combination with at least one cyan dye-forming coupler.
A cyan dye image-forming unit comprising a red-sensitive silver halide emulsion layer of at least one layer, a magenta dye-forming unit comprising at least one green-sensitive silver halide emulsion layer combined with at least one magenta dye-forming coupler, And a support carrying a yellow dye image-forming unit consisting of at least one blue-sensitive silver halide emulsion layer in combination with at least one yellow dye-forming coupler. These elements can include additional layers, such as filter layers, interlayers, overcoat layers, subbing layers, and the like. All of these can be coated on a support that can be transparent (eg, a film support) or reflective (eg, a paper support). The photographic elements protected by this invention are Research D
a magnetic recording material, such as described in isclosure, Item 34390, November 1992, or a transparent magnetic recording layer, such as those described in U.S. Pat. Nos. 4,279,945 and 4,302,523. A layer containing magnetic particles may be included below the transparent support.

Suitable silver halide emulsions and their preparation, and methods of chemical and spectral sensitization are described in Research.
Disclosure 37038, Sections I-V. Color materials and development modifiers are Research Disclosur
e 37038, sections V-XX. Vehicles are described in Section II of Research Disclosure 37038 and include various additives such as optical brighteners, antifoggants, stabilizers, light absorbers and light scattering agents, curing agents, coating aids, plasticizers. Agents, lubricants and matting agents are available from ResearchDisclo
sure 37038, sections VI-X and XI-XIV. Treatment method and treatment agent are Research Disclosur
e 37038, Sections XIX and XX, and the exposure method is described in Research Disclosure 37038, Section XVI.

Photographic elements typically contain silver halide in emulsion form. Photographic emulsions generally include a vehicle for coating the emulsion as a photographic element layer. Useful vehicles include natural substances such as proteins, protein derivatives, cellulose derivatives (eg, cellulose esters), gelatin (eg, alkali-treated gelatin, eg, bovine bone or animal gelatin, or acid-treated gelatin, eg, pigskin) Gelatin, gelatin derivatives (eg, acetylated gelatin, phthalated gelatin, etc.)
Is mentioned. Hydrophilic water-permeable colloids are also useful as vehicles or vehicle extenders. These include synthetic polymeric deflocculants, carriers, and / or binders, such as poly (vinyl alcohol), poly (vinyl lactam), acrylamide polymers, polymers of polyvinyl acetal, alkyl and sulfoalkyl acrylates and methacrylates, hydrolysis Examples include polyvinyl acetate, polyamide, polyvinyl pyridine, and methacrylamide copolymer.

The photographic element can be imagewise exposed using a variety of techniques. Typically, the exposure is to light in the visible region of the spectrum, typically with raw image light through a lens. Exposure is performed using a light emitting device (eg, LED, C
RT (for example, stored image of a computer). For example, TH James, The Theory of the Photographic
The image can be developed into photographic elements in a number of well-known photographic processes using many well-known processing compositions, such as those described in Process , Fourth Edition, Macmillan, New York, 1977. When processing color negative elements, the element is treated with a color developer (i.e., one which uses a color coupler to form a colored image dye) and then uses an oxidizing agent and a solvent to remove silver and silver halide. When processing a color reversal element, the element is first processed with a black and white developer (ie, a developer that does not form a colored dye with a coupler compound) and then a process that allows unexposed silver halide to be developed ( Usually, chemical fog or light fog) is performed, followed by processing with a color developer. Following development, bleach-fix to remove silver or silver halide, followed by washing and drying.

The present invention is illustrated by the following examples.

[0018]

EXAMPLES Materials Preparation : 300 mL degassed distilled water, 2 mL 45% Dowf into a 1 L three necked reaction flask equipped with S4 stirrer and condenser.
ax2A1 (Dow Chemical Company)
y), 1.00 g of potassium persulfate and 0.33 g
Of sodium metabisulfite was added. 60 flasks
C. bath, then 100 mL of distilled water, 2 mL of 45
% Dowfax2A1, 15 g methyl acrylate,
The contents of yet another flask containing 83 g of 2-chloroethyl acrylate and 2 g of itaconic acid were
It was added to the above reaction flask over 40 minutes. The reaction flask was stirred at 80 ° C. for 1 hour, then 0.25 g of potassium persulfate was added and the contents were added at 80 ° C. for another 90 hours.
Minutes. The flask is cooled and then the latex p
H was adjusted to 5.5 with 10% sodium hydroxide to give a latex containing 19.1% solids.
The Tg of this polymer was 4 ° C. H3 This latex was prepared in a manner similar to sample S4, except that the monomer mixture consisted of 95 g of n-butyl methacrylate and 5 g of 2-sulfo-1,1-dimethylethyl acrylate (sodium salt). H4 This latex was prepared in a manner similar to sample S4, except that the monomer mixture consisted of 50 g of methyl methacrylate, 48 g of 2-chloroethyl acrylate and 2 g of itaconic acid. H6 This latex was prepared in a manner similar to sample S4, except that the monomer mixture consisted of 60 g of ethyl methacrylate and 40 g of 2-chloroethyl acrylate. H7 This latex was prepared in a similar manner to sample S4, except that the monomer mixture consisted of 75 g of ethyl methacrylate and 25 g of 2-chloroethyl acrylate. H12 This latex was prepared in a manner similar to sample S4, except that the monomer mixture consisted of 75 g of methyl methacrylate and 25 g of 2-chloroethyl acrylate. S3 This latex was prepared in the same way as sample S4, except that the monomer mixture consisted of 15 g of ethyl methacrylate, 83 g of 2-chloroethyl acrylate and 2 g of itaconic acid. S5 This latex was prepared in the same way as sample S4, except that the monomer mixture consisted of 17 g of methyl arylate and 83 g of 2-chloroethyl acrylate. S6 This latex was sample S4, except that the monomer mixture consisted of 15 g of n-butyl methacrylate, 83 g of 2-chloroethyl acrylate and 2 g of itaconic acid.
It was prepared in the same manner as described above. S7 This latex was sample S4 except that the monomer mixture consisted of 30 g of n-butyl methacrylate, 68 g of 2-chloroethyl acrylate and 2 g of itaconic acid.
It was prepared in the same manner as described above. S8 This latex was sample S4, except that the monomer mixture consisted of 50 g of n-butyl methacrylate, 48 g of 2-chloroethyl acrylate and 2 g of itaconic acid.
It was prepared in the same manner as described above. S9 This latex was prepared in a manner similar to sample S4, except that the monomer mixture consisted of 25 g of ethyl methacrylate and 75 g of 2-chloroethyl acrylate. S10 This latex was prepared in the same way as sample S4, except that the monomer mixture consisted of 40 g of ethyl methacrylate and 60 g of 2-chloroethyl acrylate. H1 This latex was prepared in the same way as sample S4, except that the monomer mixture consisted of 15 g of methyl methacrylate, 83 g of vinylidene chloride and 2 g of itaconic acid. H2 This latex was prepared in the same way as sample S4, except that the monomer mixture consisted of 15 g of acrylonitrile, 79 g of vinylidene chloride and 6 g of acrylic acid. S13 (Polyester) Dimethyl-1,4-cyclohexanedicarboxylate (44 g), dimethyl-5-sulfoisophthalate (8.9 g), 1,4-cyclohexanedimethanol (27.3 g) and decanediol (10.5 g) )
Was weighed into a 250 mL round bottom long neck flask. A removal arm was attached to the top of the flask. Under nitrogen flow,
The monomer was first melted at 250 ° C. and then the molten monomer was purged with nitrogen. Antimony pentoxide (0.5 mL of a 6% dispersion in ethyl glycol) was added. Five drops of pure titanium isopropoxide were added and the resulting methanol distillate was collected. Two hours later, the vacuum manifold and the stirring movable blade were attached to the flask, and then the pressure was reduced while stirring. The reaction was continued under reduced pressure for 2 hours. The flask was then allowed to cool to room temperature for 30 minutes, after which the vacuum was released. The flask was frozen in liquid nitrogen and then the flask was broken to isolate the polymer. The Tg of this polymer was 17 ° C. The polymer dispersion was obtained by stirring the solid polymer in water at 80 ° C. for 14 hours. S11 (polyamide ester ) dimethyl-1,4-cyclohexanedicarboxylate (100 g) and hexmethylenediamine (57 g)
Was weighed into a 250 mL round bottom long neck flask. A removal arm was attached to the top of the flask. Under nitrogen flow,
The monomer was first melted at 250 ° C. and then the molten monomer was purged with nitrogen and then heated under nitrogen for 1 hour. Attach the vacuum manifold and stirring movable blade to the flask,
Then, the pressure was reduced while stirring. The reaction was continued under reduced pressure for 2 hours. The flask was then allowed to cool to room temperature for 30 minutes, after which the vacuum was released. Freeze the flask in liquid nitrogen,
The flask was then broken to isolate the polymer. The polyamide oligomer (7.14 g) was weighed into a 250 mL round bottom long neck flask, and then dimethyl-1,4-cyclohexanedicarboxylate (40 g), dimethyl-5
-The operation described for S13 was performed using sulfoisophthalate (11.8 g), 1,4-cyclohexanedimethanol (24.5 g) and decanediol (14.0 g). The Tg of the obtained polyamide-ester was 20 ° C. The polymer dispersion was obtained by stirring the solid polymer in water at 80 ° C. for 14 hours. Other commercially available materials were dialyzed against distilled water for 16 hours using a 20,000 molecular weight cut-off membrane to remove organic solvents and excess surfactants and salts. Glass Transition Temperature (Tg) The glass transition temperature (Tg) of the dried polymer material was measured using Differential Scanning Calorimetry (DSC) at a heating rate of 20 ° C./min. In this specification, Tg is defined as the inflection point of the glass transition. The glass transition temperatures of the materials used in the present invention are shown in Table 1 below.
Are listed. Particle size measurements All particles were characterized by photon correlation spectroscopy using a Zetasizer Model DTS5100 from Malvern Instruments.
Size is reported as Z-mean.

[0019]

[Table 1]

[0020]

[Table 2]

Sample preparation : All samples were coated on an unexposed / treated (Dmin) Kodak Edge 5 Ektacolor paper with aqueous colloidal dispersion at 3 cc / sq.
Prepared by coating at ° F to simulate the final stage of the photofinishing process. Small amount of FT-24
8, an anionic fluorosurfactant available from Bayer AG (from 0.1% to the total dry weight of the layer)
Used at 4%. Other surface active compounds can be used) and ME
39235 (40 nm polyethylene particles from Michelman, used at 0-40% based on the total dry coverage of the layer) was used in the formulation to control surface tension and coefficient of friction. The water-resistant test Ponceau Red dye is known to stain gelatin by ionic interactions. Ponceau red dye solution was prepared by dissolving 1 g of dye in 1000 g of a mixture of acetic acid and water (5 parts: 95 parts). The sample was immersed in the dye solution for 5 minutes, followed by 30 minutes.
Excess dye solution on the coating surface was removed by rinsing with water for 2 seconds and then air-dried. The sample having the protective layer excellent in water resistance did not change its appearance by the test. If no protective overcoat was applied to the surface, or if the formulation did not form a continuous overcoat layer and did not confer water resistance under the above drying conditions, the sample showed a very dark red color. Testing for Resistance to Wet Wiping A Ponceau red dye solution having a diameter of about 1 cm was placed on the sample surface for 5 minutes. The liquid was then gently wiped off with a Sturdi-WIpes paper towel, weighing about 1000 g. Several phenomena were often observed.

A: No surface scratch was observed. B: Extremely light scratch was observed on the protective overcoat. C: Extremely deep scratch was observed on the protective overcoat. D: Protective overcoat was removed by wiping. And
Ponceau red dye penetrated the image layer to produce a red mark.

The result of the visual observation was recorded. "A" is most desirable and "B" is acceptable. A result of "C" or "D" is completely unacceptable. Dry Scratch Resistance Test Each sample was rubbed with a dry paper towel 40 times under 0.75 psi pressure (500 g over a 1.375 inch diameter area). The 20 ° gloss loss of the rubbed area was recorded at an angle of 20 ° using a Gardner Micro-tri-gloss Meter relative to the unrubbed surface. Scratches generated in the rub test resulted in reduced gloss readings. Heat Blocking Test 3.5 × 4 square inch samples are placed face-to-face in a 50% RH / 60 ° C. chamber for 6 hours (contact the overcoat layer of one sample with the same overcoat of the other sample) )
A 1000 g weight was placed on these samples. The samples were separated and evaluated according to the following ratings.

10: Neither adhesion nor adhesion 9: Very slight adhesion (observation by hearing) 8: Slight adhesion (observation by hearing) 7: Slight picking (observation by visual observation) 6 ... Medium stickiness 5 ... Severe stickiness 4 ... Peeling of 0-25% coating 3 ... Peeling of 25-50% coating 2 ... Peeling of 50-75% coating 1 ... 100% coating Peeling (i.e., complete breakage) of ranking 10 is most desirable, and rankings 7-9 are acceptable. Example 1 A series of samples were prepared using the protective overcoat formulation described in Table 2.

[0025]

[Table 3]

[0026]

[Table 4]

The water resistance test was performed on all the samples, and when the samples showed water resistance, the durability test for wet rubbing and the dry scratch test were continued.
Table 3 shows the results.

[0028]

[Table 5]

[0029]

[Table 6]

As shown in Table 3, when a latex having a Tg higher than 25 ° C. was used alone, water resistance could not be imparted, and a latex having a Tg lower than 25 ° C. was used alone. In this case, it was recognized that the wet wiping durability and the dry scratch resistance were inferior. Significant improvements in water resistance, wet wiping durability and dry scratch resistance are observed when the formulations of the present invention are used in protective layers. Example 2 A sample selected from Example 1 was tested for heat blocking according to the procedure described above. The results are shown in Table 4 below.

[0031]

[Table 7]

It is well known that the glass transition temperature of gelatin increases with increasing ambient temperature due to dehydration of the gelatin, so that heat blocking at elevated temperatures is not at all important for gelatin coatings. However, the glass transition temperature of most hydrophobic polymers is not affected by the humidity or temperature of the environment, so blocking is a common problem when using low Tg polymers at high temperatures. When a low Tg polymer is used alone in the formulation for the protective layer,
Table 4 shows that heat blocking is a very serious problem, even if they have excellent water resistance. The formulations of the present invention can reduce the disadvantages of heat blocking, as indicated by the high ranking. When the sample 16 is compared with the sample 40, the high Tg
If polymer particles are combined with low Tg polymer particles, low Tg
It can be seen that the performance is improved as compared with the case where the polymer is used alone. Comparing sample 9 with sample 43, it can be seen that combining high Tg polymer particles with low Tg polymer particles improves performance as compared to using a low Tg polymer alone. Preferred Embodiment 1. An imaged photographic element having a protective overcoat thereon, said protective overcoat comprising an imaged photographic element having at least one light-sensitive silver halide emulsion layer; C. or higher and a colloidal dispersion of first polymer particles having a particle size of 5 to 500 nm and a second polymer particle having a glass transition temperature of less than 25 ° C. and a particle size of 5 to 500 nm. An aqueous coating solution having a weight ratio of particles: second polymer particles of 3:97 to 80:20 is coated on the at least one photosensitive silver halide emulsion layer; Drying to obtain an imaged photographic element having a protective overcoat.

2. An imaged photographic element having a protective overcoat according to claim 1 wherein the aqueous coating solution has a solids concentration of 1 to 50%. 3. The first polymer material comprises a polymer selected from the group consisting of polyesters, polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyanhydrides and addition polymers. An imaged photographic element having a protective overcoat according to claim 1.

4. The second polymer material is a polyester,
The protective overcoat according to claim 1, comprising a polymer selected from the group consisting of polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyanhydrides and addition polymers. An imaged photographic element having 5. The imaged photographic element having a protective overcoat according to claim 1, wherein the imaged photographic element is a photographic image on a transparent support.

6. The imaged photographic element having a protective overcoat according to claim 1, wherein the imaged photographic element is a photographic image on a reflective support. 7. The imaged photographic element having a protective overcoat according to claim 1, wherein the aqueous coating solution further comprises a biocide, a surfactant and a lubricant. 8. A support, at least one photosensitive silver halide emulsion layer superimposed on the support, first polymer particles having a glass transition temperature of 25 ° C. or more and a particle size of 5 to 500 nm, and a glass transition temperature of 25 A second polymer particle having a particle size of 5 to 500 nm lower than 0 ° C. in a weight ratio of the first polymer particle to the second polymer particle of 3:97 to 80:20. Superimposed on a neutral silver halide layer,
A protective overcoat located farthest from the support,
An imaged photographic element comprising:

9. The first polymer material is a polyester,
9. The protective overcoat according to claim 8, comprising a polymer selected from the group consisting of polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyanhydrides and addition polymers. An imaged photographic element having Ten. The second polymer material comprises a polymer selected from the group consisting of polyesters, polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyanhydrides and addition polymers. An imaged photographic element having a protective overcoat according to claim 8.

11. An imaged photographic element having a protective overcoat according to claim 8, wherein the support is transparent. 12． An imaged photographic element having a protective overcoat according to claim 8, wherein the support is reflective. 13. The imaged photographic element of claim 8, wherein the protective overcoat further comprises a biocide, a surfactant, and a lubricant.

14. 9. The imaged photographic element of claim 8, further comprising an antistatic layer superimposed on the support. 15． The imaged photographic element of claim 8, further comprising a transparent magnetic layer overlaid on the support. Although the present invention has been described in detail with particular reference to certain preferred embodiments thereof, it will be understood that changes and modifications can be made within the spirit and scope of the invention.

Claims (2)

[Claims] 1. An imaged photographic element having a protective overcoat thereon, said protective overcoat having at least one light-sensitive silver halide emulsion layer; Includes a colloidal dispersion of first polymer particles having a glass transition temperature of 25 ° C. or higher and a particle size of 5 to 500 nm and second polymer particles having a glass transition temperature of less than 25 ° C. and a particle size of 5 to 500 nm. Applying an aqueous coating solution having a weight ratio of the first polymer particles to the second polymer particles of 3:97 to 80:20 on the at least one photosensitive silver halide emulsion layer; Drying the aqueous coating solution to form an imaged photographic element having a protective overcoat. 2. A support, at least one photosensitive silver halide emulsion layer superimposed on the support, and first polymer particles having a glass transition temperature of 25 ° C. or higher and a particle size of 5 to 500 nm; A second polymer particle having a glass transition temperature of less than 25 ° C. and a particle size of 5 to 500 nm in a weight ratio of the first polymer particle to the second polymer particle of 3:97 to 80:20, And a protective overcoat furthest from the support superimposed over at least one of the light-sensitive silver halide layers of the invention.