US1434454A

US1434454A - Antistatic photographic film

Info

Publication number: US1434454A
Application number: US434354A
Authority: US
Inventors: Paul C Seel
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1920-12-31
Filing date: 1920-12-31
Publication date: 1922-11-07
Anticipated expiration: 1939-11-07

Description

P. C. SEEL.

ANTISTATIC PHOTOGRAPHIC FILM. APPLICATION man DEC-31.1920.

1 1,434,454. Patented Nov. 7, 1922.

Phafograp/Y/bn/[y 5 @1751 five La er: 1

)Vr'fmaslidlose Layer Con/airing 0 Sugar;

an Inert hygroscopic Orgaruc Compound and Wafer.

WITNESS INVENTOR ATTORNEY Patented Nov. 7, 1922.

UNITED STATES PATENT OFFICE.

PAUL C. SEEL, OF ROCHESTER, NEW YORK, ASSIGN 'OR TO EASTMAN KODAK COMPANY, 01 ROCHESTER, NEW YORK, A CORPORATION 01 NEW YORK ANTISTATIC PHOTOGRAPHIG FILM.

Application filed December 81, 1920. Serial No. 434,854.

the usual qualities and possessing in addition the property of preventing or greatly minimizing markings due to electrical discharges which are customarily referred to 1n the motion picture art as static. Other ob ects will hereinafter appear.

I have found that photographic film may be rendered substantially anti-static by incorporating in the nitrocellulose base or support thereof certain substances together with small amounts of water. The preferred substances which -I employ are glucose and glycerin. In place of the glucose analogous sugary substances ma be employed and in place of the glycerin may employ similar organic compounds of low volatility which are hygroscopic or have a strong afiinity for water and are substantially inert toward the photographic coatings.

- In the accompanying drawing the single figure is a sectional view on an exaggerated scale of a film embodying my invention.

In the drawing 1 is the base or support and 2 the sensitive layer.

In practice I mix the anti-static ingredients together and then add'such mixture to any of the usual nitrocellulose film dopes, In the preferred embodiment of my invention I add an amount of glucose equal to from 2 to 4% of the weight of the nitrocellulose in the dope, an amount of glycerin equal to from 2 to 4% of the weight of the nitrocellulose in the dope and an amount of water equal to from 2 to 4% of the weight of the nitrocellulose in the dope. f course, these proportions are merely illustrative and may be varied considerably according to the thickness of the dope and the methods of 4 and uring the iatter. But the her-2%:- described were As an illustration of the formula to which my anti-static mixture may be added the following is noted: 100 arts of nitrocellulose, 200 to 400 (say 250 parts of acetone, 200 to 400 (say 250) parts of methyl alcohol, 20 to 200 (say 40) parts of fusel oil. this may be added, if desired, 1 to 30 (say 10) parts of camphor; My mixture of 4 parts of glucose, 4 parts of glycerin and 4 parts of water is then incorporated thoroughly in the dope.

The ingredients are those commonly used in the art, of sufficient purity to yield films of the desired transparency and relative freedom from color. Various volatile solvents may be used and either acetone or methyl alcohol can be used alone in a suitable amount or varying mixtures can be employed. For the fusel oil may be substituted the other monohydroxy aliphatic alcohols of from 4 to 5 carbon atoms, like normal butyl and isobutyl alcohols.

The (lope is spread and cured by the evaporation of the volatile solvents, so as to form a transparent flexible sheet or film base in the usual way. On this support the sensitive photographic coatings or emulsions are applied and from the product motion picture films and other films are prepared as is well understood in the art. Such films are notably resistant to defects from the electrical discharges. While I am inclined to attribute this propert to the increased electrical conductivity 0 the film base, due to the moisture which is trapped or held therein by the glucose and glycerin, a knowledge of the theoretical basis of my invention is not necemary to the practicing of it, as hereinabovedescribed. It should be noted that the water, when incorporated with the sub stances and in the manner set forth in the examples given above, does not segregate in the film so as to impair the transparency of the latter.

The film base and dope are covered in my co-pending divisional application, Serial No. 461,916, filed Apr. 16, 1921.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent i photogra i i film comprising sensitive coating on a nitrocellulose support which contains a. sugar, an inert hygroscopic organic compound of low volatility and Water.

2. A photographic film comprising a sensitive coating on a nitrocellulose support which contains a sugar glycerin, and water.

3. A photographic film comprising a sensitive coating on a nitrocellulose support which contains glucose an inert hygroscopic organic compound of low volatility and Water.

i. A photographic film comprising a sensitive coating on a nitrocellulose support which contains'glucose, glycerin anti Water.

A photographic comprising a sensitive coating on a nitrocellulose support which contains an amount a sugar equal to approximately 4% or less of the weight the nitrocellulose, an amount of an inertv Weight of the nitrocellulose ancl an aincunt of Water equal to substantially l% or less of the Weight of the nitrocellulose.

'l. A photographic film comprising a sensitive coating on a nitrocellulose support Which contains an amount of glucose equal to substantially 4% or less elf the w'eight of the nitrocellulose, an amount of an inert hygroscopic' organic compound of low volatility equal to substantial 7 or less of the Weight of the nitroce lulose and an amount of Water equal to substantially 4:92 or less of the Weight of the nitrocellulose.

8. A photographic film comprising a sensitive coating" on a nitrocellulose support which contains an amount of glucose. equal to substantially. l:% or less of the Weight of the nitrocellulose, an amount of glycerin equal to substantially l% or less oi the Weight of the nitrocellulose and an amount of Water equal to sulostan lly 4% or less of the Weight oi the l'lllilOCGll'tliOSG.

9. A photographic film comprising a sensitive coating on a nitrocellulose support, which contains water ancl organic material for retaining and preventing precipitation of said Water.

Signed at Rochester, New York, this filth clay or" December, 1920