GB1583343A

GB1583343A - Coated film assemblies

Info

Publication number: GB1583343A
Application number: GB3396376A
Authority: GB
Original assignee: Bexford Ltd
Current assignee: Bexford Ltd
Priority date: 1976-08-16
Filing date: 1976-08-16
Publication date: 1981-01-28
Also published as: CA1119450A; DE2736881C2; CH633640A5; LU77968A1; DE2736881A1; NL7708965A; BE857832A; IT1115386B; FR2362423B1; FR2362423A1; JPS5322735A; JPS6052419B2

Abstract

The surface of a self-supporting plastic film is coated with a priming layer composition consisting of a copolymer. The copolymer contains one or more comonomer(s) selected from acrylic and/or methacrylic acid and/or derivatives thereof. Subsequently, the priming layer undergoes a treatment with a corona discharge which modifies its surface. Photosensitive photographic emulsions adhere without the need for a gelatinous interlayer directly on the treated priming layer.

Description

(54) IMPROVEMENTS IN COATED FILM ASSEMBLIES (71) We, BEXFORD LIMITED, Imperial Chemical House, Millbank, London SW1P 3JF, a British Company do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a process for the production of a coated photographic film base and to the production of a lightsensitive photographic film by the application of a light-sensitive photographic emulsion to the film base and to the products.

It has been widely accepted in the photographic art that a light-sensitive photographic emulsion applied directly to the surface of a plastics support film does not exhibit sufficient adhesion to the support film for use in most of the usual photographic end uses. As a result, it has become common practice to interpose two or more subbing layers between the support film and the photographic emulsion. For example, when the photographic emulsion comprises a gelatinous silver halide composition, a polymeric subbing layer and then a gelatinous subbing may be applied to the surface of the support film prior to the application of the photographic emulsion to the gelatinous subbing layer.

According to the present invention, a process for the production of a photographic film base comprises coating the surface of a selfsupporting plastics film with a subbing composition comprising a copolymer comprising one or more comonomers selected from acrylic acid, methacrylic acid or a derivative of acrylic acid or methacrylic acid, said one or more comonomers,comprising the major monomeric constituent or constituents of the subbing copolymer molecularly orienting the coated film by stretching in at least one direction, and then subjecting the surface of the applied subbing layer to a modifying treatment by corona discharge.

The present invention also relates to a photographic film base comprising a selfsupporting plastics film and a subbing layer applied to the surface of said film prior to stretching the film in at least one direction to impart molecular orientation to the film, said subbing layer comprising a copolymer comprising one or more comonomers selected from acrylic acid, methacrylic acid or a derivative of acrylic acid or methacrylic acid, the subbing layer being adherent to the plastics film and having been subjected to a surface modifying treatment by corona discharge.

According to this invention, light-sensitive photographic emulsions, such as gelatinous silver halide emulsions, adhere directly to the corona discharge treated copolymeric subbing layer of the base without further treatment or coating, e.g. with a gelatinous subbing layer.

On the other hand, it has been found that gelatinous subbing layers also adhere strongly to the treated copolymeric subbing layer and that light-sensitive photographic emulsion layers adhere strongly via the gelatinous subbing layer. Therefore, according to this invention, a gelatinous subbing layer may be interposed between the treated copolymeric subbing layer and the light-sensitive emulsion layer of a light-sensitive photographic emulsion, although it is preferred to apply the lightsensitive photographic emulsion directly to the surface of the treated copolymeric subbing layer for simplicity and economy of production and also to avoid certain technical disadvantages which may be associated with gelatinous layers, for example tackiness in damp or humid conditions, high surface fricition which can create winding problems, optical interference patterns on the film, static charge generation and an effect termed "ageing in contact" which results from components, such as hardening agents, included in coatings on the other side of the film migrating into the gelatinous subbing layer when the coated film is wound into a reel and causing premature cross-linking of the gelatin subbing layer which impairs the adhesion of the light-sensitive emulsion to the gelatin subbing layer.

The self-supporting plastics film may consist of any suitable plastics film, such as films of polysulphones and linear polyesters which may be obtained by condensing one or more dicarboxylic acids or their lower alkyl diesters, e.g. terephthalic acid, isophthalic, phthalic, 2,5-, 2,6- and 2,7-naphthalene dicarboxylic acid, succinic acid, sebacic acid, adipic acid, azelaic acid, diphenyl dicarboxylic acid, and hexahydroterephthalic acid or bis p-carboxyl phenoxy ethane, optionally with a monocarboxylic acid, such as pivalic acid, with one or more glycols, e.g. ethylene glycol, 1,3-propanediol, 1 ,4-butanediol, neopentyl glycol and 1 ,4-cyclohexane-dimethanol.

Biaxially oriented and heat-set films of polyethylene terephthalate are particularly useful for the production of the photographic films according to this invention. Such selfsupporting plastics films may be transparent and light-transmitting, optionally including photographically inert dyestuffs, e.g. blue dyestuffs for X-ray films, or may be rendred opaque by the addition of additives, such as pigments and fillers, and may in particular have a white and paper-like texture which may be achieved by the addition of suitable fillers and! or by voiding. The white and paper-like films may be used as bases for photographic prints.

The acrylic acid and/or methacrylic acid and/or derivative of acrylic acid and/or methacrylic acid comonomer(s) are the major monomeric constituent or constituents of the subbing copolymer, i.e. the molar proportion of such comonomer(s) preferably exceeds the molar proportion of any other comonomer.

Generally, the molar proportion of such comonomer(s) should preferably exceed 25 mole % of the copolymer.

Monomeric derivatives of acrylic acid and methacrylic acid which are suitable for the formation of the subbing copolymers include glycidyl acrylate and glycidyl methacrylate, alkyl esters in which the alkyl group comprises up to 10 carbon atoms, e.g. methyl, ethyl, propyl, isopropyl, butyl, hexyl, heptyl, n-octyl, and 2-ethylhexyl acrylates, halo-substituted acrylates and methacrylates, amides including N-alkylol and N-alkylsubstituted amides, e.g. acrylamide, methacrylamide, N-methylol acrylamide, N-ethanol acrylamide, N-propanolacrylamide, N-methylol methacrylamide, N-ethanol methacrylamide, N-methyl acrylamide, N-tertiary-butylacrylamide, nitriles, e.g.

acrylonitrile, halo-substituted acrylonitrile and methacrylonitrile, acrylic and methacrylic compounds containing functional hydrophilic groups, and amines including dimethylamino ethylmethacrylate.

Ethyl acrylate and methyl methacrylate are particularly useful alkyl ester comonomers and provide useful subbing properties when copolymerised together and when copolymerised with other comonomers.

The epoxy group of the glycidyl methacrylate and glycidyl acrylate monomers is effective in cross-linking the subbing copolymer thereby providing a barrier against the penetration of organic solvents which might function to weaken or destroy the bond between the subbing layer and the support film.

Cross-linking may be further enhanced by the presence of a hydrophilic acrylic or methacrylic comonomer in conjunction with glycidyl acrylate and/or glycidyl methacrylate since the hydrophilic group can crosslink with the epoxy group of the glycidyl methacrylate or glycidyl acrylate thus contributing to the barrier properties of the layer. Suitable monomers are hydroxyalkyl methacrylates such as hydroxyethyl methacrylate, and silanes which hydrolyse in aqueous media to introduce functional hydroxyl groups, such as wy-methacryloxypropyl trimethoxysilane.

Acrylonitrile is another useful comonomer for a subbing copolymer which has barrier properties against solvent penetration.

Antistatic properties may be incorporated into the copolymer by the use of acrylic and methacrylic comonomers having an ionic character, e.g. dimethylaminoethylmethacrylate acetate salt.

The subbing copolymer may also be derived from other copolymerisable ethylenically unsaturated comonomers in addition to the acrylic acid and/or methacrylic acid and/or derivatives thereof which are described above, for example styrene, derivatives of styrene, butadiene, vinyl chloroacetate, vinyl chloroacetate, vinyl benzoate, vinyl pyridine, vinyl chloride, vinylidene chloride, maleic acid and anhydride and itaconic acid and anhydride.

The subbing copolymer preferably comprises from 25 to 100 mole % of the comonomer(s) comprising acrylic acid and/or methacrylic acid and/or derivatives thereof and most preferably 51 to 100 mole %, provided that when such comonomers comprise 100 mole %, the copolymer is derived from two or more monomers comprising acrylic acid and/or methacrylic acid and/or derivatives thereof and the total of the monomeric proportions amount to 100 mole %.

Particularly suitable subbing copolymers for use according to this invention comprise 3 to 25 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 60 mole % of acrylonitrile and 35 to 95 mole % of one or more other comonomers comprising acrylic acid and/or methacrylic acid and/or derivatives thereof, such as an acrylic and/or methacrylic acid ester(s) and/or an acrylic or methacrylic monomer having a functional group, especially a hydroxyalkyl methacrylate. Preferably, such copolymers comprise 5 to 10 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 5 mole % of a hydroxyalkyl methacrylate, 1 to 40 mole % of acrylonitrile and 50 to 80 mole % of acrylic and/or methacrylic acid ester(s). An especially suitable subbing copolymer of this class consists of 7 mole % of glycidyl methacrylate, 1 mole % of hydroxyethyl methacrylate, 35 mole % of ethyl acrylate, 21 mole % of methyl methacrylate and 36 mole % of acrylonitrile. This is an example of a copolymer in which the total molar pro portions of acrylic and methacrylic acid derivatives amount to 100 mole %.

Conventional additives may be included in the copolymeric subbing layer, e.g. adhesion promoters, such as a partially hydrolysed vinyl acetate/vinyl chloride copolymer optionally admixed with a chlorinated phenol, slip and anti-static agents.

If desired, the coating dispersion or solution may contain a cross-linking agent which functions to cross-link the subbing coplymer thereby improving adhesion to the plastics film. Additionally, the cross-linking agent should preferably be capable of internal crosslinking in order to provide protection against solvent penetration. Suitable cross-linking components may comprise epoxy resins, alkyd resins, amine derivatives such as hexamethoxymethyl melamine, and/or condensation products of an amine, e.g.

melamine, diazine, urea, cyclic ethylene urea, cyclic propylene urea, thiourea, cyclic ethylene thiourea, alkyl melamines, aryl melamines, benzo guanamines, guanamines, alkyl guanamines and aryl guanamines with an aldehyde, e.g. formaldehyde. A useful condensation product is that of melamine with formaldehyde. The condensation product may optionally be alkoxylated. The cross-linking agent may be used in amounts of up to 25% by weight based on the weight of the polymer in the subbing composition.

A catalyst is also preferably employed to facilitate cross-linking, Preferred catalysts for cross-linking melamine formaldehyde include ammonium chloride, ammonium nitrate, ammonium thiocyanate, ammonium dihydrogen phosphate, ammonium sulphate, ammonium hydrogen phosphate, para toluene sulphonic acid, maleic acid stabilised by reaction with a base, and morpholinium para toluene sulphonate.

According to the invention, the copolymeric subbing layer is applied to the plastics film during of the process by which the plastics film is produced.

If the film is produced by a process of molecular orientation which is normally achieved by stretching in one or more directions it is convenient to apply the copolymeric subbing layer during the stretching operation.

Usually, oriented films are biaxially oriented by stretching in two mutually perpendicular directions, for example as is the case with polyethylene terephthalate films. The subbing layer may be applied before the stretching operation is commenced, or more preferably between the stretching operations applied in the two perpendicular directions. Such a sequence of coating between the stretching operations is preferred for the coating of oriented polyethylene terephthalate films.

The subbing layer is preferably applied as an aqueous dispersion in such an operation.

The procedure for applying the subbing composition may be any of the known coating techniques, such as dip coating, bead coating, reverse roller coating or slot coating and the composition may be applied as an aqueous latex or solution or as a solution in an organic solvent.

Corona discharge treatment may be effected in air at atmospheric pressure with conventional equipment using a high frequency, high voltage generator, preferably having a power output of from 1 to 20 kw at a potential of 1 to 100 kv.

Discharge is conveniently accomplished by passing the film over a dielectric support roller at the discharge station at a linear speed preferably of 1;0 to 500 m per minute. The discharge electrodes may be positioned 0.1 to 10.0 mm from the moving film surface. The applied subbing layer should preferably exhibit a wetting test value after corona discharge treatment exceeding 56 dynes/cm when measured by the Union Carbide Standard Wetting Test (WC 81-3/1964) with a formamide/ 'Cellosolve' (registered Trade Mark) mixture, whereas the value exhibited by an untreated layer is generally in the range 35 to 45 dynes/cm In this test, liquid mixtures having a range of surface tensions are made up using various concentrates of formamide in 'Cellosolve' (2-ethoxy ethanol) and brushed onto the surface to be examined. The wetting test value is the surface tension of the liquid mixture having the highest surface tension which does not contract into droplets within two seconds after application onto the surface.

Copolymeric subbing layers having a coat weight in the range 0.1 to 10 mg/dm2 provide satisfactory adhesion. Coat weights in the range 1.0 to 3.0 mg/dm2 are preferred.

The copolymeric subbing layers applied according to this invention to polyethylene terephthalate films are such that the film base is suitable for recycling through the filmforming extruder and stretching equipment.

The invention also relates to a process for the production of a photographic film which comprises applying a light-sensitive photographic emulsion over the surface modified copolymeric subbing layer of a photographic film base produced as described above and to the photographic film.

Any suitable light-sensitive photographic emulsion, such as a conventional gelatinous silver halide emulsion, may be applied by conventional techniques to the surface modified subbing layer. Such an emulsion may contain any of the conventional additives.

It has been found that light-sensitive emulsions bond with good adhesion, as stated above, after direct application to the surface modified layer. Therefore, according to this invention, it is preferred to apply the lightsensitive emulsion directly to the surface modified subbing layer in the production of light-sensitive photographic films.

Nevertheless, conventional gelatinous subbing layers may, if desired, be interposed between the surface modified copolymeric subbing layer and the light-sensitive photographic emulsion layer.

Such gelatin subbing layers may contain any of the usual additives such as polyvinyl acetate, particulate materials, e.g. silica, anti-blocking agents and cross-linking agents, e.g. formalin, and may be applied by any known technique.

The invention is further illustrated by the following examples, in which dry and wet adhesion have the following meanings and were assessed by the following tests.

Dry adhesion refers to the adhesion of a gelatinous silver halide emulsion via an underlying gelatin subbing layer, if present, to the plastics film in the final photographic film, assessed, both before and after processing in standard photographic chemicals, by sticking a self-adhesive tape along the torn edge of the film and rapidly separating the tape from the film.

Wet adhesion refers to the adhesion of a gelatinous silver halide emulsion via on underlying gelatin subbing layer, if present, to the plastics film in the final photographic film, assessed, after processing in the standard photographic chemicals and washing in water for 15 minutes by rubbing with a sponge over a series of lines scored in the still wet emulsion.

EXAMPLES A subbing composition was prepared from a monomer mixture of: ethyl acrylate 36 mole % methyl methacrylate 29 mole % glycidyl methacrylate 8 mole % hydroxyethyl methacrylate 2 mole % acrylonitrile 25 mole % 600 mls of water, 20 g of an emulsifier which is commercially available as 'GAFAC' (registered Trade Mark) RE6 10, 2 mls of dimethylaminoethanol, 0.6 ml of lauryl mercaptan to control molecular weight, 10% by weight of the total monomer content and 25% by weight of the total catalyst content were charged to a flask, degassed, stirred and heated at a polymerisation temperature of 60"C under an inert atmosphere. The total volume of the monomers was about 600 mls, and of the catalyst 300 mls of 0.1% aqueous solution of potassium persulphate. After the reaction had progressed for 30 minutes, the remaining monomers and a further 55% by weight of the catalyst were fed in over a period of about 3 hours. The resulting latex was stirred for a further 1 5 minutes, the remaining 20% by weight of catalyst added, and the batch was stirred for a further 15 minutes before discharge. The latex was stripped of residual monomers under partial vaccum.

This composition was diluted to 3.5% by weight solids and 0.5% by volume of a nonionic surfactant available commercially as 'Lissapol' (registered Trade Mark) N was added.

A polyethylene terephthalate film was melt extruded and quenched to the amorphous state on a cooled rotating drum. The resulting film was stretched in the direction of extrusion to about 3.5 times its original length. It was then coated on both sides with the aqueous dispersion described above by a roller coating technique and passed into a stenter oven where the coating was dried. The dried coated film was then stretched sideways about 3.5 times its original width and finally heat set at a temperature of about 210"C. The final thickness of the subbing layer on each side of the biaxially drawn film was about 0.3 micron, and the total thickness of the film was about 100 microns.

The copolymeric subbing layer was corona discharge treated at atmospheric pressure using a commercially availabe 'Vetaphone' (registered Trade Mark) 3 kw treater to produce a coating having Union Carbide Wetting Test value greater than 56 dynes/cm. The treatment conditions were film speed 20 fpm, power 2 kw electrode to film distance 1.5 mm.

A conventional X-ray silver halide photographic emulsion was applied directly to the corona discharge treated surface of the subbing layers, without interposing a gelatin subbing layer. The wet and dry emulsion adhesions were satisfactory.

EXAMPLE 2 The procedure of Example 1 was repeated to stretch a polyethylene terephthalate film and coat it with a subbing composition comprising: A carboxy modified acrylic polymer which is commercially available as 'Hycar' 260X84 10 g Distilled water 90 g The polymeric subbing layer was corona discharge treated in accordance with Example 1 and coated with a conventional gelatinous silver halide photographic emulsion. The emulsion was subjected to accelerated ageing at 50"C and 67% relative humidity for 16 hours before testing for adhesion. The wet and dry adhesion of the emulsion was satisfactory.

EXAMPLE 3 The procedure of Example 1 was repeated to stretch a polyethylene terephthalate film and coat it with a subbing composition comprising: An acrylic/vinyl chloride copolymer which is commercially available as 'Geon' (registered Trade Mark) 450X20 lOg Distilled water 90 g The copolymeric subbing layer was corona discharge treated in accordance with Example 1 and coated with a conventional gelatinous silver halide photographic emulsion. The emulsion exhibited excellent wet and dry adhesion.

EXAMPLE 4 Example 3 was repeated except that the subbing composition contained the following ingredients: An acrylic/acrylonitrile/styrene copolymer which is commercially available from Morton Williams Limited and designated AA421 10 g Distilled water 90 g The applied emulsion exhibited excellent wet and dry adhesion upon manual processing and also in conventional solutions for use in automatic processing apparatus.

EXAMPLE5 Example 3 was repeated except that the subbing composition contained the following ingredients: An ethyl acrylate/methyl methacrylate/ itaconic acid/styrene copolymer (28.5/28.5/5/38 mole % respectively) latex lOg Distilled water 90 g The silver halide emulsion applied to the corona discharge treated copolymeric subbing layer was a conventional X-ray photographic emulsion.

WHAT WE 1. A process for the production of a photographic film base, which comprises coating the surface of a self-supporting plastics film with a subbing composition comprising'a copolymer comprising one or more comonomers selected from acrylic acid, methacrylic acid or a derivative of acrylic acid or methacrylic acid, said one or more comonomers comprising the major monomeric constituent or constituents of the subbing copolymer molecularly orienting the coated film by stretching in at least one direction, and then subjecting the surface of the applied subbing layer to a modifying treatment by cornona discharge.

2. A process according to claim 1, in which the subbing copolymer is derived from one or more monomers selected from glycidyl acrylate and glycidyl methacrylate; methyl, ethyl, propyl, isopropyl, butyl, hexyl, heptyl, n-octyl, and 2-ethylhexyl acrylates, halosubstituted acrylates, and methacrylates; acrylamide, methacrylamide, N-methylol acrylamide, N-ethanol acrylamide, N-propanol acrylamide, N-methylol methacrylamide, N-ethanol methacrylamide, N-methyl acrylamide, and N-tertiary-butylacrylamide; acrylonitrile, halo-substituted acrylonitrile, and methacrylonitrile; acrylic and methacrylic compounds containing functional hydrophilic groups; and dimethylaminoethylmethacrylate.

3. A process according to claim 2, in which the subbing copolymer is derived from ethyl acrylate and methyl methacrylate.

4. A process according to claim 1, 2 or 3, in which the subbing copolymer is also derived from styrene, a derivative of styrene, butadiene, vinyl chloroacetate, vinyl benzoate, vinyl pyridine, vinyl chloride, vinylidene chloride, maleic acid, maleic anhydride, itaconic acid or itaconic anhydride.

5. A process according to any preceeding claim, in which the comonomer comprising acrylic acid and/or methacrylic acid and/or a derivative thereof comprises more than 25 mole % of the subbing copolymer.

6. A process according to claim 2, 3,4 or 5, in which the subbing copolymer comprises 3 to 25 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 60 mole % of acrylonitrile and 35 to 95 mole % of one or more other comonomers comprising acrylic acid and/or methacrylic acid and/or a derivative thereof.

7. A process according to claim 6, in which the subbing copolymer comprises 5 to 10 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 5 mole % of a hydroxyalkyl methacrylate, 1 to 40 mole % of acrylonitrile and 50 to 80 mole % of an acrylic and/or methacrylic acid ester.

8. A process according to claim 7, in which the subbing copolymer comprises 7 mole % of glycidyl methacrylate, 1 mole % of hydroxyethyl methacrylate, 35 mole % of ethyl acrylate, 21 mole % of methyl methacrylate and 36 mole % of acrylonitrile.

9. A process according to any preceding claim, in which the subbing composition contains a cross-linking agent.

10. A process according to claim 9, in which the cross-linking agent comprises an epoxy resin; an alkyd resin; hexamethoxymethyl melamine; or a condensation product of melamine, diazine, urea, cyclic ethylene urea, cyclic propylene urea, thiourea, cyclic ethylene thiourea, an alkyl melamine, an aryl melamine, a guanamine, a benzo guanamine, an alkyl guanamine or an aryl guanamine with an aldehyde.

11. A process according to any preceding claim, in which the plastics film is biaxially oriented by stretching in two mutually perpendicular directions and the subbing composition is applied between the stretching operations in the two directions.

12. A process according to any preceding claim, in which the plastics film comprises a biaxially oriented and heat-set polyethylene terephthalate film.

13. A process for the production of a photographic film, which comprises applying a light-sensitive photographic emulsion directly over the corona discharge treated copolymeric subbing layer of a photographic film base produced according to a process as claimed in any preceding claim.

14. A process for the production of a photographic film base substantially as described in any of the Examples.

15. A process for the production of a photographic film substantially as described in any of the Examples.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. adhesion. EXAMPLE 4 Example 3 was repeated except that the subbing composition contained the following ingredients: An acrylic/acrylonitrile/styrene copolymer which is commercially available from Morton Williams Limited and designated AA421 10 g Distilled water 90 g The applied emulsion exhibited excellent wet and dry adhesion upon manual processing and also in conventional solutions for use in automatic processing apparatus. EXAMPLE5 Example 3 was repeated except that the subbing composition contained the following ingredients: An ethyl acrylate/methyl methacrylate/ itaconic acid/styrene copolymer (28.5/28.5/5/38 mole % respectively) latex lOg Distilled water 90 g The silver halide emulsion applied to the corona discharge treated copolymeric subbing layer was a conventional X-ray photographic emulsion. WHAT WE

1. A process for the production of a photographic film base, which comprises coating the surface of a self-supporting plastics film with a subbing composition comprising'a copolymer comprising one or more comonomers selected from acrylic acid, methacrylic acid or a derivative of acrylic acid or methacrylic acid, said one or more comonomers comprising the major monomeric constituent or constituents of the subbing copolymer molecularly orienting the coated film by stretching in at least one direction, and then subjecting the surface of the applied subbing layer to a modifying treatment by cornona discharge.

16. A photographic film base, which com

prises a self-supporting plastics film and a subbing layer applied to the surface of said film prior to stretching the film in at least one direction to impart molecular orientation to the film, said subbing layer comprising a copolymer comprising one or more comonomers selected from acrylic acid, methacrylic acid or a derivative of acrylic acid or methacrylic acid, said one or more comonomers comprising the major monomeric constituent or constituents of the subbing copolymer, the subbing layer being adherent to the plastics film and having been subjected to a surface modifying treatment by corona discharge.

17. A photographic film base according to claim 16, in which the subbing copolymer is derived from one or more monomers selected from glycidyl acrylate and glycidyl methacrylate; methyl, ethyl, propyl, isopropyl, butyl, hexyl, heptyl, n-octyl, and 2-ethylhexyl acrylates, halo-substituted acrylates, and methacrylates; acrylamide, methacrylamide, N-methylol acrylamide, N-ethanol acrylamide, N-propanol acrylamide, N-methylol methacrylamide, N-ethanol methacrylamide, N-methyl acrylamide, and N-tertiarybutylacrylamide; acrylonitrile, halo-substituted acrylonitrile, and methacrylonitrile, acrylic and methacrylic compounds containing functional hydrophilic groups, and dimethylaminoethylmethacrylate.

18. A photographic film base according to claim 17, in which the subbing copolymer is derived from ethyl acrylate and methyl methacrylate.

19. A photographic film base according to any of claims 16, 17 or 18, in which the subbing copolymer is also derived from styrene, a derivative of styrene, butadiene, vinyl chloroacetate, vinyl benzoate, vinyl pyridine, vinyl chloride, vinylidene chloride, maleic acid, maleic anhydride, itaconic acid or itaconic anhydride.

20. A photographic film base according to any of claims 16 to 19, in which the comonomer comprising acrylic acid and/or methacrylic acid and/or derivatives thereof comprises more than 25 mole % of the subbing copolymer.

21. A photographic film base according to any of claims 17 to 20, in which the subbing copolymer comprises 3 to 25 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 60 mole % of acrylonitrile and 35 to 95 mole % of one or more other comonomers comprising acrylic acid and/or methacrylic acid and/or a derivative thereof.

22. A photographic film base according to claim 21, in which the subbing copolymer comprises 5 to 10 mole % of glycidyl methacrylate or glycidyl acrylate, 1 to 5 mole % of a hydroxyalkyl methacrylate, 1 to 40 mole % of acrylonitrile and 50 to 80 mole % of an acrylic and/or methacrylic acid ester.

23. A photographic film base according to claim 22, in which the subbing copolymer comprises 7 mole % of glycidyl methacrylate, 1 mole % of hydroxyethyl methacrylate, 35 mole % of ethyl acrylate, 21 mole % of methyl methacrylate and 36 mole % of acrylonitrile.

24. A photographic film base according to any of claims 16 to 23, in which the subbing layer contains a cross-linking agent.

25. A photographic film base according to claim 24, in which the cross-linking agent comprises an epoxy resin; an alkyd resin; hexamethoxymethyl melamine; or a condensation product of melamine, diazine, urea, cyclic ethylene urea, cyclic propylene urea, thiourea, cyclic ethylene thiourea, an alkyl melamine, an aryl melamine, a guanamine a benzo guanamine, an alkyl guanamine with an aldehyde.

26. A photographic film base according to any of claims 16 to 25, in which the plastics film comprises a biaxially oriented and heat-set polyethylene terephthalate film.

27. A photographic film, which comprises a light-sensitive photographic emulsion applied directly over the corona discharge treated polymeric subbing layer of a photographic film base according to any of claims 16 to 26.

28. A photographic film base substantially as described in any of the Examples.

29. A photographic film substantially as described in any of the Examples.