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Publication numberUS2725297 A
Publication typeGrant
Publication dateNov 29, 1955
Filing dateOct 8, 1952
Priority dateOct 8, 1952
Publication numberUS 2725297 A, US 2725297A, US-A-2725297, US2725297 A, US2725297A
InventorsDonald R Morey
Original AssigneeEastman Kodak Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Antistatic photographic film
US 2725297 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

Nov. 29, 1955 v D. R. MOREY 2,725,297

ANTISTATIC PHOTOGRAPHIC FILM Fi led Oct. 8, 1952 u EMULSION A. ANTI-STATIC LAYER CONTAIN/N6 OELAT/N,

, WATER-SOLUBLE POLYMER/O SALT, ANO

WAT E R-SOLUBLE SIMPLE INORGANIC SALT DONALD R. MORE) IN VEN TOR.

ATTORNEYS United States .Ratent AN TISTATIC PHOTOGRAPHIC FILM Donaldv R. Morey, Rochester, N. Y.,- assignor to-.Eastman Kodak Company, Rochester, N. Y.,. a corporation of New Jersey Application October 8, 1952, Serial No. 313,771

6 Claims. (Cl. 959) This invention relatesto photographic ;film and particularly to a film protected against static.

The accumulation of electrical charges on photographic tested as irregular fogged patterns in the emulsion of the filnr after it .has been developed. Thesezstatic effects are particularly noticeable in films provided with. cellulose 1 nitrate supports, although they. are. .also evident on cel- ,lulose acetate supports, pa'rticularly-sincerzthe.adventrof high speed emulsions. Static markings on film are thought to. result also upon separation of emulsion. from paper during unwinding of a stockroll when the roll. was wound -,at.a humidity sutficiently high to-irnpart sticking.

Attempts have been made to'overcome :static in photographic-film by the application of' various layers tosthe i film support. 'materials designed to dissipate the electric chargesby providinghthe film with a conductingrsurface. 1 Materials These layers have in general. consistedof which absorb moisture and thereforenprovide, a conducting surfacehave frequently been employed. :Most of these methods have not proven entirely satisfactory with the newer high speed emulsions.

It is also known that antistatic layers-may be; made by adding to gelatin certain ionic .organiczmaterialsincluding water-soluble polymeric materials as described in Morey and White U. S. 'Patent. 2,639,234. Thepusexof water-soluble inorganic acid salts .in antistatic layers:.has also been proposed. None of these types ofantistatic rcoating has, however, been broadlysatisfa'ctory.for. all' of -the different film types whichnare manufactured.

It is therefore an object of the present invention to provide a-novel and efiectivemeans of protecting a sensitive photographic-film against static. -A furtherrobject isto provide a method of coating a photographic film in order to reduce its static tendency. -A stillfurther bje'ct-is to provide a suitable means for protecting cellulose acetate films especially cellulose .triacetate-films against static. producing photographic film of. considerably lowenelec- 'trical resistance while, at .the same time,- retainingits A further object is; to provide means 'of optical transparency. Other objects will 'appear'fromthe following description of my invention.

Theseobjects .are accomplished bycoating photographic film base with a mixture of three components: (1) gelatin, (2) a water-soluble polymeric, salt, and (3) a water- -soluble simple inorganic acid salt.

The accompanying drawing shows. a sectional view of 'film constructed according to-my invention.

'The ternary mixture of gelatin, water solublegpolyrneric :salt, .andvwater-soluble simple inorganic acidtsaltwhich "I proposeitonse produces an enhancedconductivi-ty:over

that of the sum of the separate components. There is Patented "Nov. 29, 1 9

afimarked-synergistic effect -ofthe' mixture which enables thedesired conductance level to be reached without having. tohave excessive amounts of-addenda which would otherwise lead .to incompatibilityanda hazy or sticky coating.

It has been found possible to add-sufi'icient'of these addenda to bring the surface resistivity below 10 ohms, a value which is sufficient to alleviate difiiculties from static electricity generated in the normal handling of the film. The surface resistance of the-usual gelatin backing is 50 to 100 times the value stated-above.

The surface resistivity was measured placing two parallel electrodes on the film at a fixed relative humidity of 50%; these electrodes are long compared to the distance between them, so as to avoid end effects. The observed resistance reading is divided 'by" the distance between electrodes and multiplied by their length, to obtain the surface resistivity.

' The ternary mixtures which I propose to use contain the following ingredients:

1. Gelatin. 2. Water-soluble polymeric salt, e. g.;

Carboxy methyl cellulose (sodium salt). Sodium alginate. Sodium cellulose sulfate. Cellulose acetate sodium sulfate. Methyl methacrylate methacrylic acid (sodium salt). Sulfonated polystyrene (sodium salt). Sodium polyethylene glycol lauroyl sulfate. 3. Water-soluble, simple. inorganic acid salt, e. g. sodium chloride.

When used to preventstatic on sensitive photographic film the mixtures of my invention may beincorporated in the. sensitive emulsion layer in. an..overcoating layer or used as a backing layer. Our agents possess such physical properties that when applied to the back of a cellulose ester film they form a cleartransparent layer on the film without any undesirable physical or photographic efiects. It is, of course, assumed that the'addenda willbe properly chosen or purified so that they have no fogging or desensitizing action upon light-sensitive emulsions. Our ternary mixtures are preferably applied to the back of the film, that is, to the side opposite that of the sensitive emulsion layer.

- The following examplesillustratemethods of applying the ternary mixturetofilms according to my invention.

Example 1 To an .aqueous. gelatin.solutioncontaining 5%: of

. gelatinthere was. added.20%' ofv the weight of thetgelatin of the sodium .salt .of carboxyme'thyl cellulose and. 2%

halide emulsion. This film showed good optical appear ance-of the backing. Films similarly coatedwith gelatin alone -and-with gelatin plus 20% of the-weight'ofthe gelatin of the-sodium salt of 'carboxymethyl cellulose and .with gelatin plus 2%of'the'weight ofgelatin'of sodium chloride were-brought to equilibrium with"50'% relative humidity and tested for electrical conductance. (in computing the'sum of the separate cor'iductances, the value for the gelatin check coating was subtractedpsincesgelatin would otherwisenbeuaddedtwice, i. e. with, the ..sodium chloride. .and .with. the. polymerusalt.) "The: following. re-

sults for electrical conductance were ObtainedKinthe tables, the value for ohms is the reciprocal ohms reading):

' l/RXlO ohms Gelatin check coating 0.069 Gelatin+20 percent Na salt of carboxymethyl cellulose 3.23 Gelatin-#2 percent NaCl 0.38 Sum of separate conductances of the components 3.54 Gelatin+20 percent CMC+2 percent NaCl 8.33

A synergistic factor of over 2 was obtained. Similar tests were made using other polymer salts with the following results.

Example 2 Ohms Gelatin check coating 0.011 Gelatin+20 percent sodium alginate 1.47 Gelatin+2 percent NaCl 0.141

Sum of separate conductances of the components 1.60 Gelatin+20 percent Na alginate-i-Z percent NaCl 6.25

A synergistic factor of nearly 4 was obtained.

Example 3 Ohms Gelatin check coating 0.014 Gelatin+10 percent sodium cellulose sulfate 0.045 Gelatin+2 percent NaCl 0.068

Sum of separate conductances of the components 0.099 Gelatin-H percent sodium cellulose sulfate+2 percent NaCl 0.217

A synergistic factor of 2 was obtained.

Example 4 Ohms Gelatin check coating as 0.014 Gelatin+20 percent sodium cellulose sulfate a- 0.061 Gelatin+2 percent NaCl 0.068

Sum of separate conductances of the components 0.115 Gelatin-l-ZO percent sodium cellulose sulfate+2 percent NaCl 0.333

A synergistic factor of 3 was obtained.

Gelatin-{-20 percent copolymer+4 percent NaCL- 125.

A synergistic factor of 26 was obtained.

Example 7 4 Ohms Gelatin check coating 0.01 Gelatin-F20 percent Na salt of sulfonated polystyrene 0.18 Gelatin-l-Z percent NaCl 0.1

Sum of separate conductances of the components 0.27 Gelatin-[-20 percent sulfonated polystyrene-l-Z percent Nam A synergistic factor of 4 was obtained.

In my coatings as finally dried, the gelatin should comprise at least 75% by weight of the ternary mixture;

the water-soluble polymeric salt should comprise between about 5 and 20% or slightly more, of the weight of the gelatin and the simple inorganic acid salt should comprise from about 2 to 10% or slightly more, of the weight of the gelatin.

In the accompanying drawing,

The single figure is a sectional view of a film constructed according to my invention. As shown therein, a suitably subbed film support 5.0 of any appropriate film base material such as cellulose acetate has coated thereon a gelatin-silver halide emulsion 111 and on the opposite side a layer 12 of gelatin, water-soluble polymeric salt and Water-soluble simple inorganic acid salt.

It will be understood that my invention is capable of numerous modifications within the scope of the appended claims.

I claim:

1. An antistatic photographic film comprising a cellulose ester support having thereon a sensitive silver halide emulsion layer and in one of the layers of the film a mixture of (l) gelatin, (2) a water-soluble polymeric salt selected from the group consisting of Water-soluble salts of carboxymethyl cellulose, alginic acid, cellulose acid sulfate, cellulose acetate acid sulfate, methyl methacrylate-methacrylic acid, sulfonated polystyrene and polyethylene glycol lauroyl acid sulfate, and (3) from about 2% to 10% of the weight of gelatin of sodium chloride, said gelatin comprising at least 75 by weight of said mixture.

2. An antistatic photographic film comprising a cellu lose ester support having one one side thereon a sensitive silver halide emulsion layer, and on the opposite side thereof a layer comprising a mixture of gelatin, the sodium salt of carboxymethyl cellulose, and from about 2% to 10% of the Weight of gelatin of sodium chloride, said gelatin comprising at least 75 of saidmixture.

3. An antistatic photographic film comprising a cellulose ester support having on one side tiereon a sensitive silver halide emulsion layer, and on the opposite side thereof a layer comprising a mixture of gelatin, sodium alginate, and from about 2% to 10% of the weight of gelatin of sodium chloride, said gelatin comprising at least 75 of said mixture.

4. An antistatic photographic film comprising a cellulose ester support having on one side thereon a sensitive silver halide emulsion layer, and on the opposite side thereof a layer comprising a mixture of gelatin, sodium cellulose sulfate, and from about 2% to 10% of the Weight of gelatin of sodium chloride, said gelatin comprising at least 75 of said mixture.

5. An antistatic photographic film comprising a cellulose ester support having on one side thereon a sensitive silver halide emulsion layer, and on the opposite side thereof a layer comprising a mixture of gelatin, cellulose acetate sodium sulfate, and from about 2% to 10% of the Weight of gelatin of sodium chloride, said gelatin comprising at least 75 of said mixture.

6. An antistatic photographic film comprising a cellulose ester support having on one side thereon a sensitive silver halide emulsion layer, and on the opposite side thereof a layer comprising a mixture of gelatin, the sodium salt of methyl-methacrylate-methacrylic acid, and from about 2% to 10% of the weight of gelatin of sodium chloride, said gelatin comprising at least 75% of said mixture.

References Cited in the file of this patent UNITED STATES PATENTS 1,981,102 Hagedorn et al. Nov. 20, 1934 2,118,059 Slack et a1. May 24, 1938 2,127,621 Staud et a1 Aug. 23, 1938 2,322,085 Yutzy June 15, 1943 2,357,590 Iatfe Sept. 5, 1944 2,386,167 Murray Oct. 2, 1945

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1981102 *Aug 14, 1933Nov 20, 1934Agfa Ansco CorpPhotographic material and process of making the same
US2118059 *Sep 20, 1935May 24, 1938Eastman Kodak CoAntistatic photographic film
US2127621 *Apr 16, 1936Aug 23, 1938Eastman Kodak CoPhotographic emulsions
US2322085 *May 14, 1941Jun 15, 1943Eastman Kodak CoPhotographic emulsion
US2357590 *Jul 18, 1939Sep 5, 1944Chromogen IncPhotographic layers and process of manufacture thereof
US2386167 *Aug 28, 1943Oct 2, 1945Du PontPhotographic article of manufacture
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2972535 *Sep 3, 1957Feb 21, 1961Eastman Kodak CoQuaternary salts of c-vinylpyridine polymers with compounds containing a haloacetyl group
US2972536 *Sep 3, 1957Feb 21, 1961Eastman Kodak CoAnti-static quaternary salts of c-vinylpyridine polymers with haloacetone cyanohydrins
US2972537 *Sep 3, 1957Feb 21, 1961Eastman Kodak CoCondensation products of polyvinylketones with hydrazides containing quaternary nitrogen groups
US2972538 *Sep 3, 1957Feb 21, 1961Eastman Kodak CoCondensation products of c-vinylpyridinium haloketone polymers with hydrazides containing quaternary nitrogen groups
US2976148 *Jan 2, 1957Mar 21, 1961Gen Aniline & Film CorpAntistatic backing layers for photographic film
US3039870 *Jan 29, 1960Jun 19, 1962Eastman Kodak CoAntistatic copolymers comprising salts of n-sulfoalkyl-alpha, beta-unsaturated dicarboxylic imides
US3062649 *Aug 26, 1958Nov 6, 1962Eastman Kodak CoPhotographic film with antistatic layer
US3082087 *Nov 12, 1959Mar 19, 1963Eastman Kodak CoAntistatic photographic films
US3184311 *Mar 9, 1962May 18, 1965Eastman Kodak CoFurcellaran as an antistatic agent for photographic film
US3206312 *Jun 12, 1962Sep 14, 1965Eastman Kodak CoPhotographic film having antistatic agent therein
US3437484 *Jul 26, 1965Apr 8, 1969Eastman Kodak CoAntistatic film compositions and elements
US3653906 *Sep 29, 1969Apr 4, 1972Ilford LtdPhotographic material containing antistatic coating
US3655386 *Feb 9, 1970Apr 11, 1972Ilford LtdAnti-static coatings for photographic materials
US3769020 *Feb 11, 1971Oct 30, 1973Agfa Gevaert AgPhotographic material with improved properties
US3857729 *Sep 21, 1972Dec 31, 1974H BurwasserIndicia receiving matte sheet materials having an outermost antistatic layer
US3861924 *Feb 9, 1973Jan 21, 1975Gaf CorpImprovement in viscosity of gelatin solutions for photosensitive materials
US4196001 *Apr 16, 1975Apr 1, 1980Eastman Kodak CompanyAntistatic layer for photographic elements
US4225665 *Dec 20, 1978Sep 30, 1980E. I. Du Pont De Nemours And CompanyPhotographic element in which the antistatic layer is interlinked in the base
US4268623 *Jan 11, 1980May 19, 1981Fuji Photo Film Co., Ltd.Photographic light-sensitive material having a carboxylic acid polymer antistatic layer
US4272616 *Jun 7, 1979Jun 9, 1981Fuji Photo Film Co., Ltd.Photographic radiation-sensitive materials having improved antistatic property
US4335201 *Nov 24, 1980Jun 15, 1982Eastman Kodak CompanyAntistatic compositions and elements containing same
US5108884 *Mar 26, 1991Apr 28, 1992Mitsubishi Paper Mills LimitedAntistatically finished silver halide photographic photosensitive material
EP2385425A1May 2, 2011Nov 9, 2011Fujifilm CorporationSilver halide photographic light-sensitive material for movie
WO1982001945A1 *Oct 22, 1981Jun 10, 1982Kodak Co EastmanPhotographic antistatic compositions and elements coated therewith
Classifications
U.S. Classification430/529, 430/530, 260/DIG.160
International ClassificationG03C1/85
Cooperative ClassificationY10S260/16, G03C1/85
European ClassificationG03C1/85