Patent GB-1094004-A (GB)
Title: A method of subbing a photographic film
Inventor: OOBA SEICHI
IPC: C08J7/12
Filed: 1965-09-09
Abstract: A method of subbing a photographic film comprises irradiating a film support formed from a biaxially orientated crystalline linear polyester containing an aromatic carbonyl group with u.v. light of wavelength 1800 to 3200 , in the presence of free oxygen and/or free ozone, and thereafter applying to the irradiated surface of the support a solution or dispersion of a hydrophilic organic resin in an organic medium in which 1 to 25% of a solvent or swelling agent for the polyester is contained.  The polyester may be polyethylene terephthalate, a copolyester of terephthalic acid-isophthalic acid-glycol, or poly-1, 4-cyclohexyenodimethyl terephthalate.  The rubbing solution may comprise an organic, solvent-soluble hydrophilic resin, e.g. gelatin, a gelatin swelling agent, a dispersing agent, an organic solvent and further additives including hardening agents, antistatic agents, dyestuffs, hydrophilic and hydrophobic resins.  A gelatin hardening agent such as an ethylene imine derivative, an epoxy derivative, or a hydrophobic resin, e.g. a partially saponified vinyl chloride-vinyl acetate copolymer or cellulose nitrate may be added.  The hydrophilic resin may be resin containing one or more <FORM:1094004/B1-B2/1> (where R1 and R2 are H, -CH3, -C2 H5, -C3 H7, or -C4H9), -SO3M (where M is H or an alkali metal), or nitrogen-containing heterocyclic groups, e.g. cellulose acetate phthalate, maleate, a vinyl copolymer containing maleic anhydride such as a 1:1 vinyl acetate-maleic anhydride copolymer, acetal mixtures containing -SO3M groups and rederived from polyvinyl alcohols as referred to in Specification 894,509, or p  containing -COOM groups and derived from polyvinyl alcohols, a polyvinyl alcohol partially esterified with a divalent acid, and a mixture of polyvinyl pyrrolidone and polyacrylic acid.  The conditions during irradiation may be varied such that the quality of the film does not deteriorate. Any gaseous or liquid medium containing free oxygen and/or free ozone which does not absorb the u.v. light may be used.  Apparatus for carrying out the process is described, and tests for the adhesion of the rubbing layers to the polyester films are disclosed. Polyethylene terephthalate films are irradiated and coated in Examples (1), (2), (3), (5) with a gelatin despersion in a mixture of organic solvents, and then the subbed support is coated on one side with a gelatin-silver halide emulsion layer and an antihalation layer applied to the other side, in Example (6) with a solution of an hydrophilic resin comprising a polyvinyl alcohol acetylated with benzaldehyde and with a sodium salt of benzaldehyde 2-sulphonic acid, then with a gelatin-silver halide emulsion and an antihalation backing layer. Poly-1, 4-cyclo-hexylene-dimethylterephthalate is irradiated and coated in Example (4) with a subbing gelatin dispersion, a gelatin-silver halide emulsion, and a gelatin antihalation backing layer, in Example (8) with a subbing solution of a copolymer of diethylacrylamide and methacrylic acid, a gelatin-silver halide emulsion layer and a gelatin antihalation layer.