US3264108A - Antistatic photographic film - Google Patents

Description

, of manufactured film through the camera.

3,264,100 ANTHS'ITATHC PHUTUGRAH'HHC FlLlt i E. Scudder Maclrey and Aaron Ben-Ezra, lilinghamton,

N.Y., and Fred E. Woodward, Watchung, NJ, assignors to General Aniline dz Film @orporation, New York, N.Y., a corporation of Delaware No Drawing. Filled Mar. 19, 1963, Ser. No. 266,175 4 Claims. (Cl. %-tl) This invention relates to photographic film and more particularly to film having anti-static coatings.

Considerable difficulty has been encountered in the manufacture and use of photographic film due to the accumulation of electrical charges on the film. These elec trical charges, which are known as static, develop when photographic film is handled during processing as, for example, when film sheets are separated from each other or when motion picture film is passed through a projector. The more serious difficulty is the accumulation of static in the application of the various coatings in the manufacturing process of the photographic film and in the passage Manifestations of these charges are glow discharges which after development of the exposed film show up as black streaks or lines, or as irregular fogged patterns in the emulsion layer. Attempts have been made to overcome static in films by the application of substances which are electrolytes or possess hygroscopic properties. The function of these substances is to impart conductivity to the film and thus dissipate the electrical charges before their accumulation leads to local discharges. Many of these substances are incompatible with the materials which 'form one or more layers of the photographic film and introduce new manufacturing difficulties.

It is an object of the present invention to provide a means for eliminating static charges on a photographic film.

It is a further object to provide a means for coating photographic film whereby the composition resulting therefrom has a reduced static tendency.

Other objects will be apparent from the following description:

The above and other objects of the invention are accomplished by the present invention by incorporating in layers of the film, or on either surface of the film, an inorganic or organic salt of a phosphate ester having the formula:

wherein R represents hydrogen or an alkyl group containing from 4 to 27 carbon atoms, e.g., butyl, hexyl, octyl, nonyl, decyl, hendecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonaclecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl and beptacosyl radicals; R represents an alkyl group of from 4 to 27 carbon atoms; M represents ammonium radical, an inorganic radical derived from an alkali metal compound, e.g., sodium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., or an organic compound of the alkali metal salt thereof such as N-methyltaurine, 'sodium-N-methylsarcosinate, sarcosine, sodium sarcosinate, etc.; it is an integer representing the degree of oxyethylation ranging from 1 to 40 moles of ethylene oxide per mole of alkyl phenol;

w om-onion] O i -OM ill at and y represent positive integers ranging from i to 2, 2: being 1 when y is 2, and y being i when x is 2.

The salts utilized for purposes of the invention are prepared from known phosphate esters of ethylene oxide addition products of alkyl phenols. Such acid esters can be readily prepared, for example, by este-rifying an alkyl phenol such as nonyl phenol, dodecyl phenol, octadecyl phenol, dibutyl phenol or dinonyl phenol with phosp-orus pentoxide (P 0 under substantially anhydrous conditions at a temperature below about 115 C. for a period of four or more hours, as described in United States Patents 3,004,056 and 3,004,057.

The organic and inorganic salts may be formed in any known manner. The preferred method of preparation involves neutralizing the acid phosphate diester to a pH of about 7.0 to 7.5, followed by purification and recovery of the salt.

The anti-static agents thus formed may be applied to the film in various ways to eliminate static. As an example, they may be applied as constituents of the emul sion, as a constituent of a surface layer over the emulsion or over the base, in which instance the layer might be termed as a noncurl layer. In other instances the anti-static agent may be used as a constituent of a rinse solution applied to the surfaces of the film. A preferred procedure is to coat the film base with a gelatin sub-layer to which the anti-static agent has been added thereto in a concentration ranging from 10 to 200 grams or more per kilogram of dry gelatin.

The anti-static agents described may be used in various kinds of photographic emulsions. In addition to being useful in orthochrom-atic and panchromatic emulsions, they may also be used in non-sensitized emulsions, X-ray emulsions, paper emulsions, color emulsions or the like.

They may be used in combination with known antifoggants and stabilizers, reductionand metal-and noble metal sensitizers or in combination with other additive agents, and the like. The anti-static agents may also be employed in gelatin carriers, or other colloids such as water-soluble cellulose derivatives, e.g., hydroxy ethyl cellulose, methyl cellulose, low acetyl value cellulose acetate, and the like. Moreover, they may be incorporated on any conventional support for the emulsion such as a cellulose organic ester, e.g., cellulose acetate, cellulose propionate, etc., or filmtorming polymers, such as polyvinyl chloride, copolymers of vinyl chloride-vinyl acetate, and the like.

The following examples illustrate the best mode now contemplated for carrying out the invention.

EXAMPLE 1 Light-sensitive silver halide photographic samples oi mm. high speed X-ray film were surface coated individually with a 2% gelatin solution containing (1) 20% by weight of sodium sarcosinatc, (2) 20% by weight of the acid phosphate ester formed from a polyoxyethylated nonyl phenol (6 moles of ethylene oxide per mole of nonyl phenol) and (3) 20% by weight of the sodium sarcosinatc salt of the acid phosphate ester formed from a polyoxycthylated nonyl phenol (6 moles of ethylene oxide per mole of nonyl phenol). Each of the coatings also contained a typical spreading agent and hardener finals. The films were conditioned at 22% and 42% humidities and tested for electrical conductance by standard electrode technique. As shown in Table l, the antistatic agent of the invention has a lower resistivity than the control by a factor of more than 14 at a relative humidity of 22% and 42%.

Patented August 2, i060 1 No special surface additive.

EXAMPLE 2 The light-sensitive film samples prepared in Example 1 were also given a practical handling test to determine finger rub susceptibility. The finger rub tests were examined for static handling marks on eight pieces of each sample. As illustrated below in Table II, the control sample, the sodium sarcosinate and acid phosphate ester all showed considerable static in most of the pieces. The anti-static agent of the invention, however, produced static-free samples.

Table II Sample i N i L M H 1 Control 2 3 3 (1) 1 7 0 0 (2) 0 2 2 4 (3) 8 0 0 O 1 No special surface additive.

1 Number of strips having No, Light, Medium or Heavy static.

Various modifications of the invention will occur to persons skilled in the art. Thus, it is evident that in lieu of using the compounds of the examples, any of the compounds mentioned above can be employed with similar results. Therefore, it is not intended that the invention be limited in the patent granted except as necessitated by the appended claims.

O-(CHr-ClIzOh] O wherein R represents an alkyl group of from 4 to 27 carbon atoms; R; is a member of the group consisting of hydrogen and an alkyl group of from 4 to 27 carbon atoms; M represents a radical derived from a salt-forming compound; n represents the degree of oxyethylation ranging from 1 to x and y are positive integers ranging from 1 to 2, x being 2 when is 1 and y being 2 when x is l.

2. The material of claim 1 wherein the anti-static layer is located in a layer adjacent to the photographic emulsion layer.

3. The material of claim 2 wherein the anti-static layer is located in gelatin.

4. The material of claim 3 wherein the salt-forming compound is sodium sarcosinate.

References Cited by the Examiner UNITED STATES PATENTS 2,639,234 5/1953 Marcy et al. 96-87 3,004,056 10/1961 Nunn er al 252-351 3,039,870 6/1962 Laakso et al 96--87 NORMAN G. TORCHIN, Primary Examiner.

T. I. HOFFMANN, Examiner.

R. H. SMITH, Assistant Examiner.

Claims (1)

1. A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT CARRYING A PHOTOGRAPHIC SILVER HALIDE EMULSION LAYER AND AN ANTI-STATIC LAYER COMPRISING A SALT OF A PHOSPHATE ESTER HAVING THE FORMULA: