GB2038207A - Method for adhering hydrophilic colloid layers on plastic film supports - Google Patents

Abstract

At least two hydrophilic colloid layers are finely adhered onto a plastics film support by simultaneously or successively coating at least two hydrophilic colloid layers referred to as a first layer, a second layer,..., and an n-th layer (n >/= 2) from the support, whilst satisfying the conditions represented by the equations, <IMAGE> B1 DIVIDED A1>/= 0.65 (n>/=2), preferably 0.65 to 2.0, wherein the solid content per unit area of the hydrophilic colloid in each layer is A1,A2..., An (g/m<2>), and the solid content per unit area of polymer latex in each layer is B1, B2,..., Bn (g/m<2>). Silver halide photographic materials are thus made, without a subbing layer.

Description

SPECIFICATION Method for adhering hydrophilic colloid layers on plastic film supports The present invention relates to a technique where by at least two hydrophilic colloid layers can be firmly adhered to a plastic film support and more particularly relates to a technique for firmly adhering hydrophilic colloid layers to a plastic film support without a subbing layer. The method is useful in making silver halide photographic materials.

Polyethylene terephthalate, cellulose triacetate, polystyrene and polyolefin laminated papers are conventionally used as photographic supports, because they are excellent in transparency and in flexibility. However, it has been very difficult to firmly adhere photographic layers containing a hydrophilic colloid such as gelatin to the support due to its hydrophobic surface.

In methods for firmly adhering a hydrophobic support to a photographic layer, the following two modifications have been made to overcome the above-mentioned difficulty.

(1) A photographic layer is directly coated on a support after the surface of the support is treated by a surface activating treatment such as by a chemical treatment, a mechanical treatment, a corona discharge treatment, a flame treament, an ultraviolet radiation treatment, a high (radio frequency) microwave treatment, a glow discharge treatment, an active plasma treatment, a laser treatment, a mixed acid treatment and an ozone oxidizing treatment.

(2) A subbing layer is applied, the solvent thereof is removed by drying and the photographic layer is coated thereon.

With method (1), it has been difficult to obtain sufficient adhesive strength and method (2) has the following disadvantages.

A. Adhesive strength is not sufficient. Particularly in the case where the support is polyethylene terephthalate of polystyrene and a subbing layer is applied to the surface activated support, the resins which firmly adhere to the support do not firmly adhere to the photographic layer. On the other hand, the hydrophilic resins which firmly adhere to the photographic layer do not sufficiently adhere to the support.

B. Much time and many steps are necessary to apply the subbing layer. Not only the copolymers, the starting material from which the monomer is selected from vinyl chloride, vinylidene, chloride, methacrylic acid acrylic acid, itaconic acid and maleic anhydride, but also polyethylene imine, epoxy resin and grafted gelatin-nitrocellulose have been used. It is, however, necessary to heat these copolymers to a high temperature (1 OO"C and higher) after coating, followed by drying. Organic solvents are often used as a solvent in the case of the above mentioned synthetic high molecular compounds. Accordingly, a separate coating apparatus must be used for coating the subbing layer, which is different from that for coating the photographic layers which are normally dried at temperatures lower than 40 C, and this increases costs.

C. There are toxicity problems such as skin irritation and air pollution. In most cases it is necessary to use the solvents which are contained in the coating solution for the subbing layer to swell and dissolve the support, which requires etching agents which have strong polarity and high boiling point. These etching agents are generally difficult to handle and toxic. For example, phenol compounds conventionally used for subbing polyesters easily penetrate the skin, and when contained in the waste air and water they can damage the environment.

D. Film flatness is degraded. In conventional techniques, considerably high temperatures are required to dry the subbing layer. For example, since the above-mentioned phenol compounds generally have boiling points of not lower than 180 C, heat treatments for a considerably longer time are required to dry the subbing layer. This heat treatment causes a degradation in the film flatness and markedly reduces the commercial value of the film.

E. Temperature adjustment is difficult during drying. Generally, the etching effect of a solvent markedly depends on temperature. Adhesion itself depends on the temperature of coating and drying.

Accordingly, the temperatures at which a subbing layer may be dried are very limited. This factor poses a serious problem to continuous production.

As mentioned above, there are many disadvantages when a subbing layer is employed to increase adhesion strength. On the other hand, it has been well known to those skilled in this field to incorporate various polymer latex in a binder of a hydrophilic colloid layer coated on a subbing layer for the purpose of: (1) improving the adhesive strength of the subbing layer; and (2) preventing dimensional changes in the photographic film caused by changes in temperature and moisture.

Such techniques are disclosed, for example, in U.S. Patents 3,062,674 and 3,700,456, British Patent 1,222,714, Japanese Patent Publications 4272/64, 17702/64 and 13482/68 and U.S. Patents 2,376,005, 2,763,625,2,772,166,2,852,386,2,853,457,3,397,988 3,411,911,3,488,708 and 3,939,130.

A hydrophilic colloid layer including a binder and a large amount of polymer latex adheres easily to other objects when contacted therewith at high humidity, particularly under high temperatures and high humidity. This phenomenon takes place between photographic materials or between photographic materials and other materials during production, during development or during storage, and often causes undesired effects. This phenomenon is the so-called blocking phenomenon. Resistance to blocking is called "antiblocking property".

A matting technique has been used to increase the surface roughness of a colloid layer to prevent block- ing in which fine particles having an average diameter of 1 to 5 microns (a so-called matting agent) such as silica, magnesium oxide, polymethyl methacrylate, etc. are incorporated in the outermost layers of a photographic material. However, an unlimited amount of matting agent can not be employed to prevent the blocking, because it reduces the transparency of images formed by developing, adversely affects image granularity and reduces the sliding property of the surfaces of light-sensitive photo graphic materials which makes them easy to scratch.

Therefore, a first object of the present invention is to provide a method for firmly adhering a hyd rophilic colloid layer to the surface of a plastic film support without a subbing layer.

A second object of the present invention is to provide a method for preparing light-sensitive photographic materials having a hydrophilic colloid layer firmly adhered a support surface having excellent dimensional stability to temperature and humidity, and having good antiblocking property.

A third object of the present invention is to provide light-sensitive photographic materials of which a hydrophilic colloid layer is firmly adhered to a support surface, of which the dimensional stability and antiblocking property are good, and for which transparency after development is not reduced.

These objects of the present invention can be attained by firmly adhering at least two hydrophilic colloid layers on the surface of a plastic film support which is subjected to a surface activation treatment without employing a subbing layer by simultaneously or successively coating at least two hydrophilic colloid layers referred to as the first layer, second layer . . ., and n-th layer (n A/2) from the support, in which conditions (1) and (2) are met:: B2 ~.... + Bn < 0.5 A1 +B2 + ~- An B (z) > 0.65 (n > 2) A1 wherein the solid content per unit area of hydrophilic colloid of each layer is A1, A2 ..., An (g/m2), and the solid content per unit area of the polymer latex in each layer is B1, B2 .. ., Bn (g/m2).

The present invention is characterized by adjusting the solid content per unit area of the polymer latex in each layer on the surface of a support with respect to the solid content per unit area of the hydrophilic colloid employed as a binder in each layer such that Condition (1) is satisfied, and by adjusting the solid content per unit area of the polymer latex in the first layer directly adjacent the surface of the support with respect to the solid content per unit area of the binder in the first layer such that Condition (2) is satisfied.

Preferably Condition (1) is within the range of about 0.05 to 0.5. Ba/A1 is preferably 0.65 to 2.0 and more preferably 0.65 to 1.50. The above conditions of the invention can be applied to layer constructions on one surface or both surfaces of the support.

As described above, a polymer latex has been incorporated into a hydrophilic colloid binder to improve adhesion to the support and the dimensional stability to temperature and humidity. However, as explained above, the present invention is different from conventional methods as disclosed, for example, in U.S. Patent 3,062,674. This is because: (1) Intheinventionthehydrophiliccolloid layer is directly adhered to the (activated) surface of the support while in the conventional method a subbing layer is provided between the support and the photographic layer.

(2) The condition B5/A1 V 0.65 must be satisfied in order to firmly adhere the hydrophilic colloid layer to the activated support surface. If B,/A, is not satisfied, the adhesion of the layer to the support is reduced. It is not sufficient to adjust only the dry weight ratio of the hydrophilic colloid binder to the polymer latex in the first layer which is directly adjacent to the support to which at least two hydrophilic colloid layers are firmly adhered without a subbing layer, to nave good dimensional stability and antiblocking property. The condition B1 + B2 + + ' . .Be < 0.5 must be also satisfied Al f A2 + .... + An must also be satisfied to provide a photographic light-sensitive material having good adhesive strength, dimensional stability and antiblocking property. These are the features of the present invention. If B1 + B2 + Be > 0.5, it is impossible to A1 + A2 + +An + An it is impossible to reduce blocking.

A hydrophilic colloid layer in the present invention includes a silver halide emulsion layer, a surface protective layer, and intermediate layer, a filter layer, an antihalation layer, a backing layer coated on the surface of the support opposite to the silver halide emulsion layer to control curl, and an overcoat layer for a backing layer in black-and-white light-sensitive materials and color light-sensitive materials, and an image-receiving layer in diffusion-transfer photographic materials. Not all hydrophilic colloid layers must contain a polymer latex. However the first layer must contain the polymer latex, and the equations (1) and (2) must be satisfied for the total element.

The support for light-sensitive photographic materials employed in the present invention can be selected based on transparency, flexibility and other chemical properties, and includes (1) a styrene polymer such as polystyrene, styrene-butadiene copolymer, styrene-butadiene-acrylonitrile copolymer or poly(a-methylstyrene), (2) a polyester such as polyethylene terephthalate, polyhexamethylene terephthalate, polyethylene-2, 6-naphthalate, polycarbonate of polybutylene terephthalate, (3) a poly-olefin polymer such as polyethylene or polypropylene, (4) a cellulose ester such as cellulose triacetate or cellulose diacetate, and (5) a laminated film such as a plastic laminated on paper.

These supports can be either transparent or opaque depending on the purpose of the light-sensitive materials. A transparent support may be colorless or colored by a dye or a pigment. An opaque support can include a laminated film which is composed of a plastic film containing a pigment such as titanium dioxide and laminated on paper.

Surface activation treatments of the support which may be employed include corona discharge, vacuum glow discharge, electrodeless plasma discharge and flame treatment.

In corona discharge, the time for treatment, discharging electric power, the distance between the electrode and the support, etc. affect the degree of the treatment which also affects the adhesive strength of the hydrophilic colloid to the support. In vacuum glow discharge and electrodeless plasma discharge, the time of the treatment, the vacuum pressure, the electric power, etc. affect the adhesive strength. These surface activating treatments are disclosed, for example, in Japanese Patent Publica tions 7578/60, 10336/61, 22004/70, 22005/70, 24040/70,43480/71, Japanese Patent Application (OPI) 13672/78 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application".), U.S.Patents 3,057,792,3,057,795, 3,179,482,3,288,638, 3,309,299,3,424,735, 3,462,335, 3,475,307,3,761,299, and British Patent 997,093. It can also be referred to in Japanese Patent Application (OPI) 25071/78, U.S. Patents 3,573,916, 3,582,333,3,549,406,3,607,345,3,531,314,3,702,258 and British Patents 1,060,526 and 1,267,215.

The present invention can be applied to a lightsensitive material which comprises a support having coated thereon at least one silver halide emulsion layer and at least one surface protective colloid layer, for example, lithographic light-sensitive materials, X-ray light-sensitive materials, black-andwhite light-sensitive materials, negative color lightsensitive materials, color reversal light-sensitive materials, positive black and white light-sensitive materials, positive color light-sensitive materials, direct-positive light-sensitive materials, etc.

A surface protective layer is a layer having a thickness of about 0.3 to 3 cm, preferably about 0.5 to 1.5 # and containing a hydrophilic colloid such as gelatin as a binder. The protective layer can also include a matting agent such as fine particles of polymethyl methacrylate; a colloidal silica; a viscosityincreasing agent such as potassium polystyrene sulfonate; a gelatin hardening agent; and a UV absorbing agent.

The hydrophilic colloid layers employed in the invention contain as a binder (i.e., as the hydrophilic organic protective colloid), a natural or synthetic hydrophilic high molecular material such as gelatin, carboxy modified gelatin (e.g., phthalated gelatin, maleated gelatin or acylated gelatin), cellulose derivatives (e.g., carboxymethyl cellulose of hydroxyethyl cellulose), grafted gelatins (e.g., gelatin drafted with acrylic acid, methacrylic acid or amide), polyvinyl alcohol, polyhydroxyalkyl acrylate, polyvinyl pyrrolidone, vinylpyrrol idone-vinyl acetate copolymer, casein, agarose, albumin, sodium alginate, polysaccharide, agar, starch, grafted starch, polyacrylamide, acrylated polyethyleneimine; homopolymers, copolymers or partially hydrolyzed homopolymers of copolymers of monomers such as acrylic acid, methacrylic acid, acrylamide or N-substituted methacrylamide, such as are disclosed in U.S. Patents 2,286,215,2,322,085, 2,327,808 2,541,474, 2,563,791,2,768,154, 2,808,331, 2,852,382, #,062,674, 3,142,586,3,193,386, 3,220,844,3,287,289, 3,411,911 and German Patents 1,003,587 and 1,046,492. The binder can be used alone or in mixture. The binder mixture may be composed of two or more compatible binders. The most typical binder is gelatin, all or a portion of which can be replaced by a synthetic high molecular compound or a gelatin derivative.

An organic or inorganic gelatin hardening agent can be added to the hydrophilic colloid layers of the invention alone or in combination. The hardening agents which may be used in the present invention are disclosed in The Theory of The Photographic Process 3rd edition by C. E. K. Mees and T. H. James (1966); U.S. Patents 3,316,095, 3,232,764,3,288,775, 2,732,303,3,635,718, 3,232,763,2,732,316, 2,586,168, 3,103,437,3,017,280, 2,983,611,2,725,294, 2,725,295, 3,100,704,3,091,537, 3,321,313,3,543,292 and 3,125,449 and British Patents 994,869 and 1,167,207.

Typical examples of the hardening agents include an aldehyde compound and derivative thereof such as mucochloric acid, mucobromic acid, mucophenoxychloric acid, mucophenoxybromic acid, formaldehyde, dimethylol urea, trimethylol melamine, glyoxal, monomethyl glyoxal, 2,3-dihydroxy-1 ,4- dioxane, 2,3-dihydroxy-5-methyl-1,4-dioxane succinic aldehyde, 2,5-dimethoxytetrahydrofuran or glutaraldehyde; an active vinyl compound such as divinylsulfone, N,N' - ethylene - bis(vinylsul fonylacetamide), 1, 3 - bis(vinylsulfonyl) - 2 - propanol, methylene bismaleimide, 5 - acetyl - 1,3 - diacryloyl - hexahydro - 5 - triazine, 1,3, 5 - triacryloyl - hexahydro - s - triazine or 1,3, 5 - trivinylsulfonyl hexahydro -s - triazine; an active halogen compound such as 2,4 - dichloro - 6 - hydroxy - s - triazine sodium salt, 2,4 - dichloro - 6 - (4 - sulfoanilino) - s triazine sodium salt, 2,4 - dichloro - 6 - (2 - sulfoethylamino) - s - triazine or N ,N' - bis(2 chloroethylcarbamyl)piperazine; and epoxy com pound such as bis(2,3 - epoxypropyl)methylpropyl ammonium p-toluene sulfonate, 1,4 - bis(2', 3' - epoxypropyloxy)butane, 1, 3, 5- triglycidylisocianu rate or 1,3 - diglycidyl - 5 - (y - acetoxy - ss - oxyp- ropyl)isocyanurate; an ethyleneimino compound such as 2,4,6 - triethylene - s - triazine, 1,6 - hexamethylene - N, N' - bisethyleneurea or bis - p ethyleneiminoethylthioether; a methanesulfonate compound such as 1,2 - di(methanesulfonoxy) ethane, 1,4 - di(methanesulfonoxy)butane or 1,5 di(methane - sulfonoxy)pentane; a carbodiimide compound such as dicyclo - hexylcarbodiimide, 1 cyclohexyl - 3 - (3 - trimethylaminopropyl) - carbodiimide -p - toluenesulfonate or 1 - ethyl - 3 - (3 dimethyl - aminopropyl)carbodiimide hydrochloride; an isooxazole compound such as 2, 5 dimethylisooxazole perhydrochloride, 2 - ethyl - 5 phenylisooxazole - 3' - sulfonate or 5, 5' - do phenylene) - bisisooxazole; and inorganic compound such as chrome alum or chromium acetate; a dehydrolyzed and condensed peptide reagent such as N - carboethoxy -2- isopropoxy- 1,2 - dihydro quinoline or N - (1 - morpholinocarboxy) - 4 methylpyridinium chloride; an active ester compound such as N, N' - adipoyl - dioxy - disuccinimide or N, N' - terephthaloyldioxysuccinimide; and an isocyanate compound such as toluene - 2,4 diisocyanate or 1,6 - hexamethylenediisocyanate.

The polymer latex employed in the present invention is not limited to any chemical structure but it preferably has a particle size of about 0.02 to 1.0 cm, preferably about 0.05 to 0.5 cm.

The polymer latex in the present invention which provides good dimensional stability and adhesive strength in small amounts has a glass transition temperature of not higher than 30 C, preferably about -800C to 20 C. Preferred polymers have monomer units of an alkyl ester, a hydroxyalkyl ester or a glycidyl ester of acrylic acid, or an alkyl ester, a hydroxyalkyl ester or a glycidyl ester of methacrylic acid, and have a weight average molecular weight of not less than 100,000, preferably about 300,000 to 500,000.

Typical examples of the repeating units are shown below

The polymer latexes disclosed in Japanese Patent Publication 5331/70 and U.S. Patents 2,852,386, 3,062,674,3,411,911 and 3,411,912 are suitable as well.

The hydrophilic colloid layers of the present invention can include colloidal silica. The colloidal silica has an average diameter of about 7 to 120 m,u, and is composed of silicone dioxide as main component and alumina or sodium aluminate as a minor component. Further, the colloidal silica can include an inorganic base such as sodium hydroxide, potassium hydroxide, lithium hydroxide or ammonium hydroxide, or an organic base such as tetramethyl ammonium, which is employed as a stabilizer. A pre ferred stabilizer for the colloidal silica is potassium hydroxide or ammonium hydroxide. The colloidal silica is disclosed in Egon Matijevic, Surface and Cor loid Science vol. 6, pp.3 to 100 published by John Wiley & Sons (1973).

Typical examples of colloidal silica are marketed under the registered Trade Marks "Ludox AM", "Ludox AS", "Ludox LS", "LudoxTM" and "Ludox HS" manufactured by du Pont de Nemours & Co.

(USA), "Snowtex 20", "Snowtex C", "Snowtex N" and "Snowtex 0" manufactured by Nissan Chemical Co. (Japan), "Syton C-30" and "Syton200" man- ufactured by Monsanto Chemical Co. (USA), and "Nalcoag 1030", "Nalcoag 1060" and "Nalcoag lD-21--64" manufactured by Nalco Chem Co. (USA).

A matting agent can be incorporated in the hydrophilic colloid layers of the present invention. The matting agent employed in the present invention is an inorganic or organic fine particle having an aver age particle size of about 1 to 55,a, and can include silica (silicone dioxide), magnesium oxide, titanium dioxide and calcium carbonate as inorganic matting agents, and polymethyl methacrylate, cellulose acetate propionate and polystyrene as synthetic matting agents. The preferred matting agent is silica or polymethyl methacrylate, and the most preferred matting agent is polymethyl methacrylate.

A silver halide emulsion layer in a material of the present invention can include a light-sensitive silver halide, a chemical sensitizing agent, an antifoggant, a surface active agent, a spectral sensitizing agent, a dye, a color coupler and an oil. Any of the above additives or than conventionally used in conjunction with silver halide emulsions can be employed in the present invention. See for example, "Product Licensing Index" vol.92, pages 107 to 110 (December, 1971).

The hydrophilic colloid layer can be coated by any of the methods disclosed in U.S. Patents 2,681,294, 2,761,791,3,508,947, British Patents 837,059 and 1,028,809. In the invention, it is preferred that a first layer and a second layer, and, if necessary, a third and a fourth layer are simultaneously coated. The coated layers should not be dried at temperatures higher than 600C and preferably not higher than 50 C.

Various photographic film constructions can rnake use of the present invention. For example a combination of a silver halide emulsion layer and a protect- ing layer in that order on the support can enjoy the benefits of the present invention if the solid contents of those layers satisfy the above equations. Similarly a combination of two or more silver halide emulsion layers and a protecting layer or a combination of red-, green-, and blue-sensitive emulsion layers and associated filter, protecting and antihalation layers can make use of the invention. On the reverse side of the support a combination of upper and lower backing layers satisfying the equations (1) and (2) can be coated without a subbing layer.Basically the present invention is applicable to coating any two or more hydrophilic colloid layers on a plastic support and, as such, even image-receiving elements comprising a support, a mordanting layer and a neutralizing layer can be constructed in accordance with the present invention.

The invention will be explained in more detail by the following examples, but should not be construed as limited to these examples. In the following examples, an adhesion test, an antiblocking test and a dimensional stability test were carried out in the following manner.

1. Adhesion Test On a photographic layer, 6 lines in a vertical direction and 6 lines in a horizontal direction were cut to make 25 squares each of which were 5 mm x 5 mm.

An adhesive tape (Trade Name: "Scotch Mending Tape" manufactured bySumitomo-3 M Co.) was adhered on the photographic layer, and then the tape was quickly stripped by pulling at an angle of 1800C. Adhesive strength was evaluated on the basis of the following five grades showing the number of stripped squares on the photographic layer.

Number of Grade Stripped Squares A Otto5 B 6to10 C 11to15 D 16to20 E 21to25 Grade A or B (preferably Grade A) is practically du rable for photographic materials.

2. Adhesion Test of Wet Films Cross marks 1 cm x 1 cm were made with a stylus on the surface of the film in a processing solution during development processing and then the marks were rubbed strongly 20 times by a finger. The adhesive strength was evaluated based on the following 5 grades according to the width of the stripped cross marks.

Grade Width A 0to0.9m/m B 1.0 to 2.9 m/m C 3.0 to 5.0 m/m D D No resistance to stripping E Naturally stripped Grade A or B is practically durable for photographic materials (preferably Grade A).

3. Antiblocking Test Apair of samples 4 cm x 4 cm were allowed to stand at 350C and 75 % RH (relative humidity) for 24 hours. 1 kg of pressure was applied to a pair of samples in which a backing layer and a protective layer for the light-sensitive layer were contacted and which were allowed to stand for 24 hours. After removing the pressure, the backing layer was strip ped from the protective layer, and the adhered area of the layers was measured. The surface of the stripped protective layer adhered to the backing layer was smoothed and was easily capable of reflecting light.

Blocking was evaluated based on the following scale.

Ratio of Adhered Areas to Non-Adhered Areas A O to 25% B 26to50% C 52to75% D Not less than 76% or unstrippable because of strong adhesive strength 4. Dimensional Stability A sample having a length of 20 cm at 250C and 50 % RH was allowed to stand at 250C and 65 % RH, and the stretched length (X: positive number) was measured. Further, the sample was allowed to stand at 250C and 30 % RH, and the shrunken length (Y: positive number) was measured. The change of dimensional stability (X + Y) was calculated. The smaller the value of X + Y, the better the dimensional stability.

EXAMPLE 1 On a surface of polyethylene terephthalate film having a thickness of 100 microns, the surfaces of which had been treated by glow discharge for 1.0 second at an electric power of 3000 Watts under a reduced atmospheric pressure of 0.05 mmHg, a silver halide emulsion layer having the composition (1) given below and a protective layer having the composition (2) on the silver halide emulsion layer were simultaneously coated and then dried at 40 C.

On the other surface of the polyethylene terephthalate film, two backing layers having the composition (3) in Table 1 were simultaneously coated and then dried at 400C to provide Samples (1) to (3).

Composition (1): Silver Halide Emulsion Layer Gelatin 3.0 g/m2 Silverchloroiodobromide 4.5 g/m2 (Cl: 80 mol%, Br: 19.5 mol%, l: 0.5 mol%) Chloroauric acid 0.1 mg/m2 Polyethylacrylate latex (solid content) 2.0 g/m2 Spectral sensitizer 6 mg/m2 (3#alIyl#5##2#(1 -ethyl)-4-methyl-2- tetrazoline - 5 - ylidene - ethylidenel rhodanine) Antifoggant 30 mg/m2 (4-hydroxy-6-methyl-1 ,3,3a,7-tetraazi ndene) Surfactant 40 mg/m2 (p-dodecyl-benzene sodium sulfonate) Polyoxyethylene compound 20 mg/m2 ({HO(CH2CH2O)10r(CH2)4Oi14(CH2CH2O)10H}) Gelatin hardening agent 60 mg/m2 (2-hydroxy-4,6-dich Ioro-s-triazin e sodium salt) Composition (2): Protective Layer Gelatin 1 glum2 Matting agent 0.05 g/m2 (polymethylmethacrylate having an average diameter of 3.0 to 4.0,a) Surface active agent 0.03 (p-dodecylbenzene sodium sulfonate) Gelatin hardening agent 0.01 g/m2 (2 - hydroxy - 4,6 - dichloro -s - triazine sodium salt) Colloidal silica 0.24g/m2 (Snowtex-0 manufactured by Nissan Chemical Co.

treated with potassium hydroxide to adjust the pH to 9.5) Table 1 Composition (3): Backing Layer Sample (1) Sample (2) Sample (3) Lower Upper Lower Upper Lwer Upper backing backing backing backing Lower Upper layer layer layerlayer layer layer (n- 2) (n- 2) (n 1) Cm- 2) (n = n Cm 2) Gelatin (Solid content: An/m2) 0.6 g/m2 4.0 g/m2 0.6 g/m2 4.0 gIn2 0.6 g/m2 4.0g/m2 Polyetbylacrylate polymer latex (Solid content:: Bn/m2) 0.3 g/m2 0.6 g/m2 0.8 g/n2 0.6 g/m2 0.8 g/n2 2.0 g/m2 Colloidal silica. none 5 g/lO0 g none 5 g/lO0 g none 5 g/l90 g gelatin gelatin gelatin Gelatin hardening agent' none 60 mg/n2 none 60 mg/n2 none 60 mg/n2 Surface active agent' none 40 mg/m none 40 mg/m2 none 40 mg/m2 B1 / A1 0.5 1.33 1.33 (B1 + B2) / (A1 + A2) 0.20 0.30 0.61 same as in Composition (2) The adhesive strength in dry condition and in a developing solution, and the antiblocking property of Samples (1), (2) and (3) were measured and the results shown in Table 2 were obtained.

Table 2 Sample Sample Sample (1) (2) (3) Adhesive strength D A A (dry condition) Adhesive strength D A A developing solution Antiblocking A A D property Of Samples (1) and (2) both of which satisfied the Condition (1), Sample (2) which satisfied Condition (1) provided good adhesive strength in the dry condition and in the developing solution. On the con trary, Sample (1) which did not satisfy Condition (1) provided bad adhesive strength.

Of Samples (2) and (3) both of which satisfied Condition (1), Sample (2) which also satisfied Condition (2) provided better antiblocking property than Sample (3) which did not satisfy Condition (2). That is, where both Conditions (1) and (2) were satisfied, photographic light-sensitive materials having better adhesive strength and antiblocking property were obtained.

EXAMPLE2 A polyethylene film having a thickness of 100 it and a width of 30 cm was treated by corona discharge by passing it through electrodes having a discharge power 200 Watts at a distance of 0.8 mm from the film at a rate of 2 mlmin. On the surface of the film, the silver halide emulsion layer of Example 1 and the protective layer of Example 1 were simultaneously coated and then dried at400C. On the opposite surface of the film, two backing layers having the composition (4) shown in Table 3 were simultaneously coated and then dried at 40 C.

In Table 3, the gelatin, colloidal silica, gelatin hardening agent and surface active agent were same as in Composition (2) in Example 1.

Table 3 ComPosition (4): Backing Layer Sample (4) Sample (5) Sample (6) Lower Upper Lower Upper Lower Upper backing backing backing backing backing backing layer layer layer layer layer layer Cm = l) Cm = 2) Cm = l) Cm = 2) Cm = 1) (n = 1) Gelatin (Solid content:An/m) 0.6 gIn2 4.0 gIn2 0.6 g/m2 4.0 gIn2 0.6 gIn2 4.0 gIn2 Polybutylacrylate latex (Solid content: Bn/m2) 0.6 gIn2 none 0.6 gIn2 0.3 gIn2 none none Colloidal silica none 5 g/100 g none 5 g/100 g none 5 g/100 g gelatin gelatin gelatin Gelatin hardening agent none 60 mg/n2 none 60 mg/n2 none 60 mg/n2 Surface active agent none 40 mg/m2 none 40 mg/m none 40 mg/n2 B1 / A1 1.0 1.0 0 (B1 + B2) /(A1 + A2) 0.13 0.20 0 The adhesive strength in a dry condition and in a developing solution, the antiblocking property and dimensional stability of Samples (4), (5) and (6) were measured and the results are shown in Table 4.

Table 4 Sample (4) Sample (5) Sample h6) Adhesive Strength A A D (dry condition) Adhesive Condition A A D in developing solution Antiblocking Property A A A Dimensional Stability 92 EL 88,a 140 As is apparent from Table 4, even if the upper backing layer does not contain a polymer latex, it provides better adhesive strength and antiblocking property because it satisfies both Conditions (1) and (2). The dimensional stability of Sample (4) is a little bit worse than that of Sample (5), but it is sufficient for use in photographic materials. Further, it is better than Sample (6) in which the lower backing layer (nearest the support) does not contain a polymer latex.If the two conditions are satisfied, a photographic layer having better adhesive strength, antiblocking property and dimensional stability can be obtained even if an upper backing layer has a thickness 3 times or more than the lower backing layer and does not contain a polymer latex.

EXAMPLE3 On the surface of polyethylene terephthalate support having a thickness of 100 EL and treated by a glow discharge as in Example 1, a silver halide emulsion layer as in Example 1 and a surface protective layer as in Example 1 were provided. On the opposite surface of the support, a Composition (5) for a backing layer as shown in Table 5 was coated to provide the Samples (7) and (8). The gelatin, colloidal silica and surface active agent were the same as those for Composition (2) in Example 1.

Table 5 Composition (5): Backing Layer Sample (7) Sample (8) Lower Upper lower Upper backing backing backing backing layer layer layer layer Cm = 1) Cm = 2) (n = 1) (n = 2) Gelatin (Solid content: An/m2) 0.6 gIn2 4.0 gIn2 0.6 gIn2 4.0 gIn2 Polyethylacrylate latex (Solid content: Bn/m2) 0.6 g/m 1.0 g/m2 rome none Polybutylacrylate latex (Solid content:: Bn/m2) none none 0.6 g/m2 1.0 g/m Colloidal silica none 5 g/100 g none 5 g/100 g gelatin gelatin Gelatin hardening agent' none SO mg/n2 none 80 mg/n2 Surface active agent none 40 mg/n2 none 40 mg/n2 B1 / A1 1.0 1.0 (B1 + B2) / (A1 + A2) 0.35 0.35 Gelatin hardening agent: 2-hydroxy-4,6-dichloro-s-triazine sodium salt The adhesive strength in a dry condition and in a developing solution, antiblocking property and dimensional stability of Samples (7) and (8) were measured, and the results are shown in Table 6.

Table 6 Sample (7) Sample (8) Adhesive strength A A (dry condition) Adhesive strength A A in developing solution Antiblocking property A A Dimensional stability 90 fix 86 As the results of Table 6, if Conditions (1) and (2) are satisfied, a photographic layer having better adhesive strength, antiblocking property and dimen sional stability can be obtained, even if the polymer latex added to the backing layer is varied.

EXAMPLE 4 On a surface of a polyethylene support having a thickness of 50 and treated by glow discharge at an electric power of 3000 Watts under a reduced pres sure of 0.06 mmHg for 4.0 seconds, or on the surface of a polystyrene support having a thickness of 70 and treated by a glow discharge at an electric power of 2000 Watts under a reduced pressure of 0.08 mmHg for 0.5 second, the silver halide emulsion layer of Example 1 and the surface protective layer of Example 1 were coated. On the opposite surface of the supports, Composition (6) for the backing layer was coated to provide Sample (9) (polyethylene support), Samples (10) and (11) (polystyrene support). Gelatin, colloidal silica, surface active agent and gelatin hardening agent were the same as those for Composition (5) for the backing layer in Example 3.The conditons for coating and the drying steps were the same as in Example 1.

Table 7 Composition (6): Backing Layer Sample (9) 4 (lO) Sample (11) Lower Upper Lower Upper backing backing backing backing layer layer layer layer (n = 1) (n = 2) (n = 1) (n = 2) Gelatin (Solid content: An/m2) 0.0 gIn2 4.0 gIn1 0.0 gIn2 4.0 gIn2 Styrene/acrylic acid copolymer latex (Solid content:Bn/mZ) 1.0 gIn2 1.0 gIn2 1.0 gIn2 2.0 gIn2 Colloidal silica none 5 g/100 g none 5 g/lO0 g gelatin gelatin Gelatin hardening.agent none 85 mg/n2 none 85 mg/n2 Surface active agent none 40 mg/n1 none 40 mg/n2 B1 / A1 1.25 1.25 (B1 + B2) / (A1 +A2) 0.42 0.63 The adhesive strength in a dry condition and in a developing solution, and the antiblocking property of Samples (9), (10) and (11) were measured, and the results are shown in Table 8.

Table 8 Sample {9J Sample (10) Sample (11) polyethylene polystyrene polystyrene Adhesive A A A Strength (dry condition) Adhesive A A A Strength in developing solution Antiblocking A A D property As the results of Table 8, show, if Condition (2) is satisfied, a support which is treated by flow discharge under suitable conditions has better adhesive strength. Samples (9) and (10) which satisfied Condition (1) provide good antiblocking property, but Sample (11) which does not satisfy Condition (1) provides bad antiblocking property. That is, regardless of the support a photographic layer having better adhesive strength and antiblocking property can be obtained if Conditions (1) and (2) are fulfilled.

EXAMPLE 5 On a surface of polyethylene terephthalate support having a thickness of 100 and treated by glow discharge under the same conditions as in Example 1, a backing layer having the same composition as Sample (4) in Example 2 was provided, and on the opposite surface of the support, a first layer adjacent to the support, a silver halide emulsion layer and the surface protective layer shown in Table 9 were provided to obtain Samples (12) and (13).

Table 9 Sample (12) Sample (13) First Emulsion Protective First Emulsion Protective layer layer layer layer layer layer (n = 1) (n = 2) (n = 3) (n = 1) (n = 2) (n = 3) Gelatin (Solid Content: An/m2) 1.0 g/m2 1.0 gIn2 Polyethylacrylate Composition for Composition (Solid Content:An/m ) 1.2 g/m (7)* protective 0.5 g/m* (7)* protective layer layer same as in same as in Example 1 Example 1 B1 / A1 1.2 0.5 (Bl+B2+B3) / CA1+A2#A3) 0.27 0.11 Composition (7)* Silver halide emulsion layer Gelatin (Solid content) 2.5 g/m2 Silver chloroiodobromide (C#: 80 molt, Br: 19.5 molt, I: 0.5 molt) Polyethylacr,ylate latex none Spectral sensitizer, antifoggant, polyoxyethylene compound, gelatin hardening agent and surface active agent weresame as in Example 1, and the silver halide emulsion layer was coated in a dry thickness of 5.0 p and in a silver amount of 5.0 g/m2.

The adhesive strength in a dry condition and in a developing solution, and the antiblocking property of Samples (12) and (13) were measured, and the results are shown in Table 10.

Table 10 Sample (12) Sample (13) Adhesive strength (dry condition) A D Adhesive strength in developing solution A D Antiblocking property A A As shown in Table 10, if Conditions (1) and (2) are satisfied in photographic layers having more than three layers including a silver halide emulsion layer like Sample (12), the adhesive strength and antiblocking property are better. Therefore, in order to obtain good adhesive strength and antiblocking property in photographic materials having at least three layers Conditions (1) and (2) should be satisfied.

Claims (17)

1. A method of firmly adhering at least two hydrophilic colloid layers to a plastic film support with out employing a subbing layer, which comprises simultaneously or successively coating at least two hydrophilic colloid layers, defined as a first layer, a second layer,... and a n-th layer (n~2) from the support, wherein the conditions represented by equations (1) and (2) are satisfied, B1 + B2 + .... + Bm # 0.5 (1) A1 + + .... + Am 1 j 0.65 (no 2) (2) A1 wherein the solid content per unit area of the hyd rophilic colloid in each layer is A1, A2 A# ~ ~ An (g/m2) and the solid content per unit area of polymer latex in each layer is B1, B2 . .Sm by (git2).

2. A method as claimed in Claim 1, wherein said polymer latex is a latex of a polymer having monomer units of an alkyl ester, a hydroxyalkyl ester or a glycidyl ester of acrylic acid, or an alkyl ester, a hydroxyalkyl ester or a glycidyl.

3. A method as claimed in Claim 2, wherein said polymer latex has a molecular weight of at least 100,000.

4. A method as claimed in Claim 2 or 3, wherein the polymer units are any of those shown hereinbefore as Polymers 1 to 8.

5. A method as claimed in any preceding claim, wherein said polymer latex has a particle size of 0.02 to 1 micron.

6. A method as claimed in any preceding claim, wherein said polymer latex has a glass transition point not higher than 30 C.

7. A method as claimed in any preceding claim, wherein said hydrophilic colloid is gelatin or a gelatin derivative.

8. A method as claimed in any preceding claim, wherein the surface of said support has been treated so as to activate it.

9. A method as claimed in Claim 8, wherein said activation is by corona discharge, vacuum glow discharge, electrodeless plasma discharge or flame treatment.

10. A method as claimed in any preceding claim, wherein B,/A, is 0.65 to 2.0.

11. A method as claimed in any of Claims 1 to 10, wherein said first hydrophilic colloid layer is a silver halide emulsion layer.

12. A method as claimed in Claim 11, wherein said second hydrophilic colloid layer is a surface pro tective layer.

13. A method as claimed in any of Claims 1 to 10 wherein said first hydrophilic colloid layer is a lower backing layer.

14. A method as claimed in Claim 13, wherein said second hydrophilic colloid layer is a second backing layer.

15. A method as claimed in any of Claims 1 to 10 wherein said first hydrophilic colloid layer is an anti-halation layer and said second hydrophilic col loid layer is a silver halide emulsion layer or gelatin interlayer.

16. A method as claimed in Claim 1 of adhering hydrophilic colloid layers onto a plastic film, substantially as hereinbefore described with reference to any of Samples (2), (5), (7), (8), (9), (10) or 12 of the Examples.

17. A photographic material made by a method as claimed in any preceding claim, wherein the hydrophilic colloid layers are the layers of the photographic material.