JPH11194449A - Aqueous coating composition for surface protective layer of image forming element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new surface protective layer from an aq. medium by applying an aq. coating compsn. contg. water-dispersible siloxane-contg. polyurethane and then, drying it. SOLUTION: A coating compsn. used for forming a surface protective layer contains a continuous aq. phase contg. water-dispersible siloxane-contg. polyurethane. The water-dispersible polyurethane is well-known and produced by chain- elongating a prepolymer having terminal isocyanate groups with an active hydrogen compd., usually diamine or diol. The prepolymer is prepd. by allowing di- or polyol having terminal hydroxyl groups to react with excess di- or polyisocyanate. The water-dispersible siloxane-contg. polyurethane contains silioxane bonds in its molecule. The polyurethane contg. the siloxane bonds can be achieved by using either of polysiloxane having hydroxyl or amine groups but it is preferable that the polysiloxane is diol or diamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an imaging element having improved physical properties of a surface layer, and more particularly, to an imaging element including a support, at least one imaging layer, and a surface protective layer. More particularly, the present invention relates to such imaging elements having a surface protective layer applied from an aqueous medium and exhibiting excellent surface lubricity and excellent manufacturing properties.

[0002]

2. Description of the Related Art During the handling of an image forming material such as coating, drying, finishing, winding, rewinding, printing, projection, etc., the surface of the material may be brought into contact with various devices or by the front and back of the image forming material. Often they are damaged as a result of contact between them. For example, scratches and abrasion can occur on emulsions and backsides of photographic materials. These scratches and wear marks are seen during the printing and projection steps. This causes serious problems in the actual application of the film. Furthermore, when the contact friction is high, the image forming material is not smoothly transferred during the manufacturing process or in various exposure machines, processing machines and projectors. These transfer problems result in product disposal. Recently, the conditions under which imaging materials have been manufactured and used have expanded their range of use (e.g., in a high-temperature, high-humidity atmosphere), and their manufacturing methods have been advanced (e.g., high-speed coating,
High-speed finishing and cutting, as well as rapid processing)
It has become even more severe. Under these conditions, the imaging material is more susceptible to damage.

[0003] Lubricants or glidants are often used to reduce contact friction and improve damage resistance to surfaces. Examples of lubricants used for these purposes include silicone oils as described in U.S. Pat. No. 3,489,567, and as described in U.S. Pat. No. 3,121,060. Includes wax esters of higher fatty acids or higher fatty alcohols. There are problems with using these lubricants. For example, waxes such as carnauba wax have been used to form a backing lubricant layer. However, they must be applied from a solvent such as propylene dichloride, which is on the EPAP / U High Dangerous Goods List. Furthermore, in many cases the wax must be applied as a separate layer, which requires additional application stations, thereby increasing product costs.

[0004] Silicone oils are often used as lubricants, but when stored or supplied in rolls on which the element is wound, such as photographic film for amateur photography.
They tend to migrate from one side of the imaging element to the other.
Furthermore, since these silicone oils are insoluble in water,
They must be dispersed in aqueous coating compositions in the presence of large amounts of surfactant using mechanical energy. This step results in a coating composition containing the silicone oil dispersed as fairly large droplets, which can produce a dry coating and a hazy appearance. The large amounts of surfactants used to disperse the silicone oil can cause them to foam in the coating composition and also weaken the physical properties (eg, barrier properties) of the dried layer.

[0005] Silicone-containing polymers have been described for use in backing or sliding layers for imaging materials. U.S. Pat. No. 4,961,997 describes a backing layer for a thermal recording medium containing a cured product consisting of a mixture of a silicone-modified polyurethane resin and a heat-resistant organic powder. The patent discloses that the backing layer may be coated from an organic solvent such as paraffinic solvents, aromatic solvents, ketones, alcohols, esters, and mixtures thereof. However, that patent teaches and does not disclose a backing layer applied from an aqueous medium.

US Pat. Nos. 4,910,087 and 4,942,212 describe heat-sensitive recording elements in which the heat-resistant layer is made from a polyurethane resin containing siloxane. These patents disclose that a heat-resistant layer is applied from a medium of an organic solvent.

US Pat. No. 5,330,840 describes polysiloxane-containing polyurethane coatings for rollers and belts useful for electrophotographic toner fusing. The coating is applied from an organic solvent such as tetrahydrofuran.

US Pat. No. 5,451,495 discloses a support, at least one photosensitive silver halide containing layer and a layer comprising a crosslinked polymer having a tertiary nitrogen atom which is converted to a quaternary amine. The photographic elements comprising are described. The polymer backbone is a polycondensation polymer such as polyurethane, and the crosslink is a siloxane. However, polymers containing quaternary amines are not desirable for photographic applications because they tend to interact with anionic filter dyes that are prone to dye staining after film processing. Furthermore, it is not stated that each layer is applied from an aqueous medium.

Solvent-soluble siloxane-containing polyimides and polyesters for use in the sliding layer for the dye-donor element of thermal dye transfer are described in US Pat. Nos. 5,252,534 and 5,234,889. Each is listed. These sliding layers are stated to be applied from a medium of an organic solvent.

[0010]

SUMMARY OF THE INVENTION The main object of the present invention is to:
It is an object of the present invention to provide an imaging element having a novel surface protective layer that can be applied from an aqueous medium. The coating composition used to form such a surface lubricating layer is stable with respect to the manufacturing process and is attractive from an environmental point of view. The produced surface protective layer has excellent lubricity.

[0011]

According to the present invention, the imaging element includes a support, at least one imaging layer, and an outermost protective layer. This protective layer is formed by applying an aqueous coating composition containing a water-dispersible siloxane-containing polyurethane, followed by drying. The surface protective layer of the present invention exhibits excellent lubricity and excellent production characteristics.

According to the present invention, the photographic element comprises a support,
At least one silver halide photosensitive layer and an outermost protective layer comprising a siloxane-containing polyurethane are included. The surface protective layer of the present invention exhibits excellent lubricity and excellent production characteristics.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The coating composition used to form the surface protective layer of the imaging element comprises a water-dispersible, continuous aqueous phase comprising a siloxane-containing polyurethane. Such coating compositions are particularly beneficial because they do not require the use of undesirable solvents such as chlorinated solvents, but would otherwise require the dissolution of conventional lubricants.
The coating composition has the anti-aggregation, anti-settling or anti-set properties of the lubricant. Furthermore, the coating compositions of the present invention form a dry layer that provides excellent frictional properties, and the siloxane-containing polyurethane lubricant does not migrate to other surfaces during manufacture, storage, and use of the imaging element, and No peeling during processing of the photographic film, and gives excellent lubricity to the developed film.

[0014] The imaging element of the present invention may be of many different types depending on the particular application for which it is intended. Details regarding the composition and function of a wide variety of different imaging elements are disclosed in U.S. Patent No. 5,300,676, which is incorporated herein by reference, and the references described therein. I have.

[0015] The imaging element may include various polymer films, paper, glass, etc., although both acetate and polyester supports well known in the art are preferred. The thickness of the support is not critical. Support thicknesses of 2 to 10 mils (0.002 to 0.010 inches) can be used. The support may be, for example, an undercoat or subbing layer known in the art, including a terpolymer of vinylidene chloride / methyl acrylate / itaconic acid or a terpolymer of vinylidene chloride / acrylonitrile / acrylic acid with respect to the polyester support. Is typically used.

The coating compositions of the present invention include a water-dispersible, siloxane-containing polyurethane. Water-dispersible polyurethanes are well known and are prepared by chain extending a prepolymer having terminal isocyanate groups with an active hydrogen compound, usually a diamine or diol. The prepolymer is made by reacting a diol or polyol having terminal hydroxyl groups with an excess of diisocyanate or polyisocyanate. To accept the aqueous dispersion, the polypolymer is functionalized with hydrophilic water groups. An anionic, cationic or non-ionically stable prepolymer is made. Anionic dispersions usually contain a carboxylate or sulfonate functional copolymer, for example either a suitably blocked dihydroxycarboxylic acid (dimethylolpropionic acid) or dihydroxysulfonic acid. Cationic systems are made by the introduction of a diol containing a tertiary nitrogen atom that has been converted to a quaternary ammonium salt by a suitable alkylating agent or acid. Non-ionically stable prepolymers are made using diol or diisocyanate copolymers having pendant polyethylene oxide chains. These result in stable polyurethanes over a wide range of pH. The nonionic and anionic groups may be synergistically combined to create a "suitable for all applications" urethane dispersion. Of the above, anionic polyurethanes are clearly the most useful.

Several different methods may be used to make the polyurethane dispersion. For example, a prepolymer may be made, neutralized, alkylated and, if necessary, further chain extended in an excess of an organic solvent such as acetone or tetrahydrofuran. The solution of the prepolymer is then diluted with water and the solvent is removed by distillation. This is known as the "acetone" method. Alternatively, a low molecular weight prepolymer may be made, usually reduced in the presence of a small amount of solvent, and chain-extended with a diamine immediately after the prepolymer is dispersed in water. The latter is referred to as the "prepolymer blending" method and is, for economic reasons, much more preferred than the former method.

Polyols useful for making polyurethane dispersions include diols (eg, ethylene glycol, butylene glycol, neopentyl glycol, hexanediol or mixtures of any of the above) and dicarboxylic acids or anhydrides (succinic acid, adipine Acid, suberic acid,
Azelaic acid, sebacic acid, phthalic acid, isophthalic acid,
Polyester polyols made from maleic acid and anhydrides of these acids); polyethers such as diols and polypropylene glycols and ethylenically unsaturated monomers having functional groups such as carboxyl, hydroxy, cyano and / or glycidyl groups. And polylactones made from lactones such as caprolactone which have been reacted with a hydroxy-terminated polyacrylic acid-based derivative prepared by addition polymerization of an acrylate such as an alkyl acrylate or methacrylate having the formula:

The diisocyanates which can be used are:
As follows: toluene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, ethylethylene diisocyanate, 2,3-dimethylethylene diisocyanate, 1-methyltrimethylene diisocyanate,
1,3-cyclopentylene diisocyanate, 1,4-
Cyclohexylene diisocyanate, 1,3-phenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, bis- (4-isocyanatocyclohexyl) -methane, 4,
4'-diisocyanatodiphenyl ether, tetramethylxylene diisocyanate and the like.

Compounds which are reactive with isocyanate groups and have groups capable of forming anions are as follows: dihydroxypropionic acid, dimethylolpropionic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. Other suitable compounds are sugars, such as gluconic acid, sugar acids, mucinic acid, glucuronic acid and the like.

Suitable tertiary amines used to neutralize acids to form water-dispersible anionic groups include trimethylamine, triethylamine, dimethylaniline, diethylaniline, triphenylamine and the like.

Diamines suitable for the chain extension of polyurethane include ethylenediamine, diaminopropane, hexamethylenediamine, hydrazine, aminoethylethanolamine and the like.

Solvents that may be used to help make the prepolymer, reduce its viscosity and increase its water dispersibility include methyl ethyl ketone, toluene, tetrahydrofuran, acetone, dimethylformaldehyde, N-methylpyrrolidone and the like. . Water-miscible solvents such as N-methylpyrrolidone are highly preferred.

In the context of the present invention, water-dispersible polyurethanes are characterized in that they contain siloxane bonds in their molecules. This can be achieved using either polysiloxanes having hydroxyl or amine groups, but it is preferred that the polysiloxane be a diol or diamine in making polyurethanes. Such a siloxane-containing diol or diamine is represented by the following formula:

[0025]

Embedded image

In the formula, X is an amine group or a hydroxyl group, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ ,
R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl group, an aryl group, or an arylalkyl group, and the alkyl portion of the alkyl group or the arylalkyl group is 1 to It has 6 carbon atoms and n and m are each from 0 to about 500, such that the value of n + m is from 10 to about 500.

For the purposes of the present invention, the siloxane-containing polyurethane contains more than 0.27% by weight and less than 25% by weight, preferably more than 1.0% by weight and less than 10% by weight of the siloxane component. The portion of the siloxane component is adjusted by adjusting the molecular weight value (n + m value of the above structural formula) of the siloxane component used for producing the siloxane-containing polyurethane, or by adjusting ethylene glycol, propylene glycol, polyether polyol, polyester polyol, or polyol. Polysiloxane-free conventional polyols such as acrylate polyols or conventional diamines not containing polysiloxanes such as ethylenediamine, diaminopropane, hexamethylenediamine, hydrazine, aminoethylethanolamine, etc .; polysiloxane polyols or polysiloxanes. By using with a diamine, it may be controlled within this range.

The coating composition of the present invention may be combined with other water-soluble or water-dispersible polymers in order to match the physical and chemical properties of the surface protective layer for a particular image-forming application. May be included.
Examples of the water-soluble polymer include gelatin, polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives, polystyrenesulfonic acid and its alkali metal or ammonium salts, and copolymers of acrylic acid or methacrylic acid. Water-dispersible polymers that may be used in combination with siloxane-containing polyurethanes include acrylic acid and methacrylic acid and their esters,
Latex copolymers containing ethylenically unsaturated monomers such as styrene and its derivatives, vinyl chloride, vinylidene chloride, butadiene, acrylamide and methacrylamide are included. Other water-dispersible polymers that may be used include polyurethane and polyester dispersions. Still other water-dispersible polymers include base-neutralized carboxylic acid-containing polymers described in commonly assigned U.S. Patent Application Ser. No. 712,006, filed Sep. 11, 1996. There is a latex polymer. Preferably, the surface protective layer comprises at least 2 mg / m
² siloxane containing polyurethane.

The surface protective layer composition according to the present invention also comprises
Suitable crosslinking agents may be included, including aldehydes, epoxy compounds, polyfunctional aziridines, vinyl sulfones, methoxyalkyl melamines, triazines, polyisocyanates, dioxane derivatives such as dihydroxydioxane, carbodiimide, and the like. The crosslinker may react with functional groups present on the siloxane-containing polyurethane and / or other water-soluble or water-dispersible polymers present in the coating composition.

Matting agents known in the art may also be used for the surface protective layer of the present invention, but such matting agents are described in Research, published December 1989.
Disclosure, Item 308119, Item 1008
-100 pages. When polymeric matte particles are used, the polymer is covalently bonded to the binder polymer by intermolecular crosslinking or by reaction with a cross-linking agent to promote improved adhesion of the matte particles to the coating layer. May be included. Suitable reactive functional groups include hydroxyl, carboxyl, carbodiimide, epoxide,
Aziridine, vinyl sulfone, sulfinic acid, active methylene, amino, amide, allyl and the like are included.

In the surface protective layer, magnetic recording particles, abrasive particles, conductive polymer, conductive metal oxide particles, coating aid,
Other additives such as charge control surfactants and secondary lubricants may be included. There are no particular restrictions on the secondary lubricant used. They include, for example, perfluorinated polymers, natural and synthetic waxes, silicone fluids, stearamide, oleamide, stearic acid, lauric acid,
Ethylene glycol distearate, ethylene glycol monostearate and the like may be included.

[0032] The coating compositions of the present invention may be applied as aqueous coating formulations containing up to 20% total solids by coating methods well known in the art. For example, hopper application,
Gravure application, skim pan / air knife application, spray application, and other methods are used with very satisfactory results. The coating is dried at temperatures up to 150 ° C.
A dry coating weight of 20 mg / m ^{2 to} 10 g / m ² is obtained.

The surface protective layer of the present invention is provided on the side of the support opposite to the image forming layer, and as an outermost backing layer,
Alternatively, it serves as an outermost layer applied on a weather-resistant backing layer, or as an outermost layer applied on an antistatic layer, or as an outermost layer applied on a magnetic recording layer. The surface protective layer may also be used as the outermost layer on the image forming side of the support, for example, as a protective overcoat for a silver halide emulsion layer.

In a particularly preferred embodiment, the imaging element of the present invention is a photographic element in which the image forming layer is a light-sensitive silver halide emulsion layer, such as photographic film, photographic paper or photographic glass plate. Such emulsion layers typically include a film-forming hydrophilic colloid. The most commonly used of these is gelatin, which is a particularly preferred material for use in the present invention. Useful gelatins include
Alkali-treated gelatin (cow bone or cowhide gelatin), acid-treated gelatin (pig skin gelatin) and gelatin derivatives such as acetylated gelatin, phthalated gelatin and the like are included. In addition, hydrophilic colloids that can be used alone or in combination with gelatin include dextran, gum arabic, zein, casein, pectin, collagen derivatives,
Collodion, agar, arrowroot, albumin, and the like. Still other useful hydrophilic colloids include water-soluble polyvinyl compounds such as polyvinyl alcohol, polyacrylamide, poly (vinylpyrrolidone), and the like.

The photographic elements of this invention can be single black-and-white or single-color elements which include a support having a light-sensitive silver halide emulsion layer, and they can be multilayer and / or multicolor elements. You may.

The color photographic elements of the present invention typically include a dye image-forming unit sensitive to each of the three primary gamuts of the spectrum. Each unit may be comprised of a single silver halide emulsion layer or of multiple emulsion layers sensitive to a given region of the spectrum. Each layer of the element, including the image-forming unit layers, may be arranged in various orders as is well known in the art.

Preferred photographic elements according to the present invention include at least one blue-sensitive silver halide emulsion layer containing a yellow image dye-donor, at least one green-sensitive silver halide emulsion layer containing a magenta image dye-donor, and a cyan image dye. A support bearing at least one red-sensitive silver halide emulsion layer containing a donor material.

In addition to the emulsion layers, the elements of the present invention include overcoat layers, spacer layers, filter layers, interlayers,
Auxiliary layers conventional in photographic elements may be included, such as antihalation layers, pH reducing layers (often also referred to as acidic and neutralizing layers), timing layers, opaque reflective layers, opaque light absorbing layers, and the like. The support can be any suitable support used in photographic elements. Typical supports include polymer films, paper (including polymer-coated paper), glass, and the like. Details of the support and other layers of the photographic element of the present invention can be found in Research Disclosur.
e, Section 36544, September 1994, and Rese
arch Disclosure, Section 38957, 1
Inc., September 996, which is incorporated herein by reference.

The light-sensitive silver halide emulsions used in the photographic elements of the present invention may include coarse, medium or fine silver halide crystals or mixtures thereof, and may include silver chloride, bromide, It may consist of silver, silver bromoiodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide and mixtures thereof. The emulsion may be, for example, a tabular grain light sensitive silver halide emulsion. The emulsions can be negative working or direct positive emulsions.
They can form a latent image mainly on the surface of the silver halide grains or inside the silver halide grains. They are,
Chemical sensitization and spectral sensitization may be performed according to a usual method. The emulsion is typically a gelatin emulsion, although other hydrophilic colloids can be used according to conventional techniques. For details on the silver halide emulsion, see Research
ch Disclosure, Item 36544, 199
September 2004, Research Disclosure,
Section 38957, September 1996, and references cited therein.

The photographic silver halide emulsion used in the present invention may contain other additives commonly used in the photographic art. Useful additives include, for example, Research D
issueclosure, paragraph 36544, September 1994 and Research Disclosure, No. 3.
8957, September 1996. Useful additives include light-absorbing agents such as spectral sensitizing dyes, desensitizers, antifoggants, masking couplers, DIR colors, DIR compounds, stain inhibitors, image dye stabilizers, filter dyes and UV absorbers. Substances, light-scattering substances, coating aids, plasticizers and lubricants.

Depending on the dye image-donor used in the photographic element, it may be contained in a silver halide emulsion layer or in a separate layer associated with the emulsion layer. Dye image-providing substances include dye-forming couplers,
Any of those known in the art, such as desilvering dyes, color developers, and redox dye releasers, the particular used may depend on the characteristics of the element and the type of image desired. Is determined.

The dye image-donor used in conventional color formers designed to be treated with another solution is preferably a dye-forming coupler, ie, combined with an oxidized color developing agent to convert the dye. The resulting compound. Preferred couplers that produce cyan dye images are phenol and naphthol. Preferred couplers that produce magenta dye images are pyrazolones and pyrazolotriazoles. Preferred couplers that produce yellow dye images are benzoylacetanilides and pivalyl acetanilides.

[0043]

The following examples serve to illustrate the invention. However, it should be understood that the invention is not limited to these examples.

EXAMPLES 1-3 AND COMPARATIVE SAMPLE A In the following examples, the coating compositions of the present invention provide stable coating formulations and have very clear and excellent friction properties (ie, low friction properties). Value coefficient). Siloxane (Witcobond 232, Witco)
Water-dispersible polyurethane having about 5% by weight of polydimethylsiloxane and water-dispersible polyurethane
Polydimethylsiloxane (Neorez R9649,
The coating composition of the protective layer, including Zeneca Resins, was coated from an aqueous medium onto a polyethylene terephthalate imaging support previously primed with a vinylidene chloride-containing terpolymer latex. 100 coatings
Drying at 0 ° C. yielded a layer having a total dry coat weight of 1000 mg / m ² . The coefficient of friction (COF) was determined using ANSIIT9.
Determined using the method set forth in 4-1992. The stability of the coating formulation and the appearance of the dried film were also visually evaluated. Table 1 shows the results. The results show that the coating composition of the present invention is very stable and forms a transparent and excellent lubricating dry film.

[0045]

[Table 1]

EXAMPLES 4-6 AND COMPARATIVE SAMPLE B In the following examples, coating compositions of the present invention in which a urethane-siloxane polymer lubricant is used in a gelatin binder provide stable coating formulations and It has been shown to provide a dry film that is transparent and has excellent friction properties (ie, low coefficient of friction values). Water-dispersible polyurethane
Polydimethylsiloxane (Neorez R9649, Z
(Eneca Resins), lime-processed gelatin, and bis (vinylsulfone) methane hardening solution on a polyethylene terephthalate imaging support previously primed with a vinylidene chloride-containing terpolymer latex. From an aqueous medium. The coating was cooled and fixed at 4.5 ° C, dried at 21 ° C,
Drying at 8 ° C. yielded a layer having a total dry coat weight of 800 mg / m ² . The coefficient of friction (COF) was set to ANSIIT 9.4
Determined using the method specified in -1992. The stability of the coating formulation and the appearance of the dried film were evaluated visually. Table 2 shows the results. The results show that the gelatin-containing coating composition of the present invention is very stable, and forms a dry film having excellent transparency and lubricity.

[0047]

[Table 2]

While the preferred embodiment of the invention has been illustrated and described, various changes and modifications will become apparent to those skilled in the art. However, all such changes and modifications are considered to be included in the present invention.

Finally, preferred embodiments of the present invention will be listed. 1. A support, at least one image forming layer on the support, and an outermost layer formed by drying and coating a coating composition containing an aqueous medium having a water-dispersible siloxane-containing polyurethane on the support; An imaging element comprising a protective overcoat.

2. The imaging element of claim 1, wherein said support comprises a polymer film, paper or glass.

3. 2. The imaging element of claim 1, further comprising a subbing layer on the support.

4. The imaging element of claim 1, wherein the siloxane comprises a siloxane-containing diol or diamine represented by the following formula:

Embedded image Wherein X is an amine group or a hydroxyl group;
^{R 1, R 2, R 3} , R 4, R 5, R 6, R 7, R 8, R
⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl, aryl, or arylalkyl group (where the alkyl portion of the alkyl or arylalkyl group has 1 to 6 carbon atoms); n and m are each 0 to about 500 (provided that the value of n + m is 10 to about 5)
00). )

5. When the siloxane-containing polyurethane is 0.1%
The imaging element of claim 1, comprising more than 25% by weight and less than 25% by weight of the siloxane component.

6. A photographic element comprising a support, at least one silver halide photosensitive layer on said support, and an outermost protective overcoat comprising a water-dispersible siloxane-containing polyurethane on said support.

7. The photographic element of claim 6, wherein the support comprises a polymer film, paper or glass.

8. The photographic element of claim 6, further comprising a subbing layer on the support.

9. The photographic element of claim 6, wherein the siloxane comprises a siloxane-containing diol or diamine represented by the following formula:

Embedded image Wherein X is an amino group or a hydroxyl group;
^{1, R 2, R 3,} R 4, R 5, R 6, R 7, R 8,
R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently an alkyl, aryl or arylalkyl group (where the alkyl portion of the alkyl or arylalkyl group has 1 to 6 carbon atoms); , N and m are
Each is 0 to about 500 (however, the value of n + m is 10 to about 500). )

10. The siloxane-containing polyurethane is
The photographic element of claim 6, comprising more than 0.25% by weight and less than 25% by weight of the siloxane component.

Continued on the front page (72) Inventor Yonkai One United States, New York 14526, Penfield, Hickory Pond Drive 2 (72) Inventor Mario Dennis DeLaura United States, New York 14464, Hamlin, Close Hollow Drive 87

Claims (2)

[Claims] 1. A coating composition comprising a support, an at least one image forming layer on the support, and an aqueous medium having a water-dispersible siloxane-containing polyurethane on the support, formed by coating and drying. An outermost protective overcoat. 2. A support, at least one silver halide photosensitive layer on the support, and an outermost protective overcoat containing a water-dispersible siloxane-containing polyurethane on the support. Photo element.