US 2080066 A
Description (OCR text may contain errors)
, 066 ZGSO! SHEPPARD ET s E- 937.. 1 l l May GE ACKA PRES'ERVING P FILM 1933 .led oct. 31' F1 @hm www me Patented May 11,' 1937 FILM rnEsEavlnG rscmscr:v
Samuel E. Sheppard and John J. Schmitt, Rochest'er, N. Y., assignors, by -mesne assignments, to Eastman Kodak Company, Jersey Gity, N. J., a corporation of New Jersey Application October 31, 1933, Serial No. 696,012
(ci. 20s-sez) 6 Claims.
This invention relates to' photography and more-particularly to packaging photographica'lly light-sensitive film to prevent-deterioration.
It has been common practice to use wooden cores for winding convolutions of iiim or convolution of lm and film backing paper for photographic use. The coils of film so wound are ordinarily sold in cans or other substantially moistureproof containers which preserve the ilm from the vusual climatic changes vto which it is subjected.
The use of such wooden cores has som'e advantages and some disadvantages. One of the advantages is that a wooden core may absorb and give off a certain amount of moisture which ls desirable but at the same time the wooden core is liable to give off vaporswhich react on the photographic lm and cause it to become fogged. This is due to the liberation of volatile peroxides, chiefly hydrogen peroxide.
In Patent No. 1,921,950, Samuel E. Sheppard. August 8, 1933, non-fogging photographic packing materials are considered and in this patent various methods of treating woodencores to prevent them from giving oi fogging materials are disclosed.
In order to overcome the above-mentioned and other diiculties due to the use of wooden cores, metallic cores are coming into use, these having many advantages over the wooden cores. It has been found, however, that with the use of a metallic support for the film, there is a greater tendency for water vapor to condense due to the temperature changes and form liquid drops of water which are responsible for the so-called moisture spots and moisture mottle which ruins I film.
Our present invention is particularly directed to a means for overcoming or at least minimizingv the tendency to condensation. To obtain the desired results we fill the metal core or place in the film package a substance of high moisture regain which will both take upwater vapor with fair velocity and also give it up. Thus, such a substance will serve as a stabilizing material and f will prevent the-formation of liquid water drops due to condensation. y
It is obvious that it is not highly important as to the location of the stabilizing material ln the film package, except that it is, of course, desirable to have such material in a position in which it can readily performthe desired function.
Coming now to the drawing wherein like reference characters denote like parts throughout:
Figure 1 is a perspective view partially in section showing a film package constructed in accordance with and embodying a preferred form of our invention.
4Figure 2 is a perspective view of a film core which may be used in accordance with a dliletent embodiment of our invention.
Figure 3 is a section through still another type of lm core suited for use with our invention.
Figure 4 is a. sectionV through a film package suitable for use with the ordinary hand camera Iiilm cartridges, but equipped for use with our invention, and
Figure 5 is a section through a lm package constructed' in accordance with still another embodiment of our invention.
In Figure 1 we have illustrated a usual type i of lm package in which the film F is supported on a spool which consists of a cylindrical hub member I and Bange members 2 for protecting the edges of the film. Such spools are well known.
However, the hub member l differs from the usual hub members in having' a series of perforatlons 3 in the periphery of the hub and a series of perforations l in the anges lying over the ends of the hub. These perforatlons permit the air inside the container to circulate freely through and around the hub. The film spool is enclosed in a can consisting of a top member 5 and a bottom member 6 which lit together through the flanges I and B which inter-engage to form a tight joint. This joint is renderedsubstantially air-tight by means of a paster or tape 9 which may be of the usual surgeons adhesive tape so that the entire package is substantially moistureproof.
The moisture content of the room in which the lm is packed and of the ilm itself determines to a largeextent the moisture conditions in the air inside of the package. However, it has been found that due to temperature changes the film given 01T.
y It is. important that the materials'used should be incapable Aof deliquescing and liquefying however much moisture they may take up, because of course, if they should liquefy they would spoil the i'llm in the same Way as the water drops. It is also important that 'the materials must be chemically inert towards the nlm-that is, that they must not give off vapors Vwhich deleteriously aiect the nlm.
We have found as suitable materials to place in the lm package that vapor absorbing mineral gels may be used, such as silica gel. iron `oxide gels may be mixed and if desired. We have also found that cellulosic materials may be used. vsuoli as Vwood pulp3. paper pulp, mercerlzed, washed, and dried cotton cellulose. These may be used alone or mixed.
In the case of cellulose materials, where 'there is a possibility of auto-oxidation and production of logging peromdes, this-may be overcome by pretreatment with permanganate solutions as considered in the patent abovementioned-No.
In the speciiicatlon and in the claims where we use the term stabilizing material, we mean any ofthe materials in the classes above referred to, or broadly a material capable of both absorbingand giving od moisture to stabilize the moisture content of the film 'package preventing the formation of waterdroplets. Such materials really transfer the moisture to and from the film as temperature conditions change and prevent moisture from condensing into drops of water.
v.as mentioned above, the stabilizing materials may be treated, if desired, tol prevent chemical fogging of the iilm.
It is impossible to give deiinite limits of humidity at which the nlm may take-up or give od moisture because there are so many contributing factors. Film, when packed, may contain quite widely varying moisture content. The lm may be packaged under varying conditions'o humidity. Consequently with diderent nlm packages the moisture transfer may occur at dlerent temperatures.
Referring again to the drawing, it is possible to place a loose or unsupported coil of in a container in which a small box contains the stabilizing material, or the box may be made into a hub by making itv cylindrical as shown in Figure 2 wherein the lhub consists of a cylindrical periphery il perforated at i2 having a bottom i3 perforated'at Il. The stabilizing materials may be introduced through a cover member l5 and the film may be wound directly on the hub i i.
In accordance with Figure 3, a hub i@ is shown as having a central opening il with perforations it and as including side walls ld perforated vat 2d. stabilizing material lil may be placed inside of the annular space' 2l' and the moisture can pass through the slots I8 and 29'.
It is customary to pack nlm for cameras of l the amateur type in moistureproof metal containers such as lead or composition tubes. Figure 4 we have illustrated such a tube at 25, this tube supporting convolutions of film or nlm and backing paper 26 wound upon -a hub 2l on the ends of which there are flanges 28. The hub may be perforated at 29 so that the stabilizing material lil may absorb and may give oli moisture to the lm 26.
Figure shows another type of container which -may be used to carry outour invention. In this case the lrn 3B is wound on an imperforate cylindrical member 3l which may t loosely over a box 32 which is perforated at 33 and which contains a stabilizing material l0. For convenience, this box opens on the outside of the container which consists of two parts 84 and 35 which may be sealed together in any suitable manner. A
screw cap or door 3S permits the stabilizing material to be introduced into the package.
aosaoee `gels, or alumina oxide gels. Different mineral 'While it is not necessary tor the lm package to be absolutely moistureproof, best results can be obtained .with a stabilizing material, in accordance with our invention, by having the package nsubstantially moisture-proof because the condition of the lmcan be beter controlled.
We are aware that iilm has been packed in containers in which an absorbent material may be partially saturated with a liquid capable of maintaining the air in the case in a moist condition. Such containers are frequently used for developed which is not so susceptible to moisture spots and which becomes very dry and brittlc through passing through the light beam of a Howevenpsuch a humidifying device is totally unsuitable for unexposed light-sensitive photographic film.
We are also aware that the use of calcium `chloride or other moisture absorbing substances has been suggested particularly for use with certain types of light-sensitive photographic paper which must be kept extremely dry before um.
obviously such a material is unautea for and would not accomplish applicants purpose.
In one case the sole object is to supply moisture to a film to prevent it from becoming dried out and brittle, and in the other case the object is solely to keep the photographic paper as dry as possible.
Our ,present invention is not for either oi these purposes.` We do not wish to moisten dry film or keep sensitive material dry. Our invention is stabilizing the moisture content of a nlm package and preventing moisture spots on lm byy transferring moisture back and forth, if temperature conditions require it, between a moisfrom the following group, silica gel, iron'oxlde gel, alumina gel.
3. A photographic film package including photographically light sensitive material enclosed with a moisture-stabilizing material consisting essentially of silica gel.
4. A photographic lm package including photographically lightv sensitive material enclosed with a moisture-stabilizing material consisting essentially of iron oxide gel.
5.- A photographic film package including photographically light sensitive material enclosed with a moisture-stabilizing material consisting essentially of aluminum gel.
6. A photographic nlm package including photographically light sensitive material enclosed with a moisture-stabilizing material consisting essentially of a mixture of mineral gels having the properties of giving up and absorbing mois--l ture;
SAMUEL E. sHEPPAaD. JOHN J. scm/irma4