US1954333A - Wrapping paper for photographic goods - Google Patents

Description

Patented Apr. 10, 1934 WRAPPING PAPER, ron rnoroonsrmo GOODS Samuel E. Sheppard and Herbert J. Dietz,

Rochester, N.

Y., assignors to Eastman Kodak Company, Rochester, N. Y., -a corporation of New York No Drawing. Application May 13, 1930, Serial No. 452,127

8 Claims.

This invention relates to a process and product for the wrapping of, light-sensitive materials and particularly to the preparation of wrapping papers'having thereon various markings of contrasting colors. i

The paper which is usually employed for wrapping photographic plates and films is frequently the source or trouble in the sense that a fogging or desensitizing of the light-sensitive emulsions is effected. This is particularly liable to be the case in respect of roll film, as used in photographic roll film cameras, because of the various convolutions of the film, one side being rolled up in contact with the emulsion, and the back of that wrapping paper coming in contact with the film support, or more usually, a gelatin coating on the back of said support. Any inequality of the paper, in regard to emanations or fogging vapors therefrom, is liable, therefore, by this immediate contact, to produce corresponding inequalities of density on the developed film. This condition is liable to be accentuated by the presence of imprints: signs, letters, ornumerals, put upon the paper, as, for example to indicate the batch or roll number, the origin, or to signal to the operator the number of the particular exposure. Apart from mere mechanical offsetting, such imprints are liable to give pseudo-photographic offsetting, whether by fogging (increase of local density on development) or by desensitizing =-('decrease of local density).

i The inherent chemical emulsion fog of any photographic emulsion is liable to be enhanced or added to on storage or incubation in the presence of almost any organic material which is in any degree autoxidizable by reason of the production of peroxides, and especially the volatile hydrogen peroxide. This is notably the case in certain substances, .such as drying oils, resins and the like. But even when such substances are reduced to a minimum, it is extremely difficult, probably impossible to have organic materials present-and they are necessarily present, as the gelatin and the film support itself-without some degree of autoxidation taking place in the presence of air and moisture. So that, although the fog due to this cause may be and is in good practice reduced to a very small amount and in most instances to a slight veil not. objectionable to the photographic use of such materials, yet a slight fog'will normally be produced, and tend to increase somewhat with the age of the product, i. e., with time of storage. i

So long as this slight veil of fog is uniform over the plate, it is unobjectionable or harmless, but if anything occurs to locally interfere with the autoxidation of the paper (and of course its constituents) and consequently perceptibly en-, hance or diminish this slight veil or fog, then this differential reduces the photographic purposes.

An object of the present invention is to provide a process for the preparation of materials which contact with light sensitive coatings, the former having no offsetting effect upon the coatings. By the term, offsetting effect, is meant the tendency of portions of light sensitive coatings to unevenly fog due to the stimulusof the surrounding materials. Another object of this invention is to provide a process for the preparation of wrapping paper for photographic goods, such paper having no offsetting effect upon the coatings. Another object of this invention is to provide a process for the preparation of wrapping paper for photographic goods, such paper having no offsetting effect upon the photographic material wrapped therewith. Other objects will hereinafter appear.

We have found that if anyone of a number of substantially pure inorganic pigments and certain lakes, (which, of course, consist of the compound resulting from the interaction of a mordant and a dye, the lake being preferably prepared in a state of fine subdivision), are suspended in a considerable quantity of gelatin or other colloid binder and dried, and are then brought into close contact with the sensitivesurface of a photographic plate or film, which is then stored or incubated, that the area in contact with the. pigmented or laked layer shows a materially decreased or increased fog density because the lake or pigment has an increased power of catalytically destroying hydrogen peroxide which is formed by autoxidation of the paper utility of the product for itself (or its constituents or even the binder used in the ink) and which peroxide, as known in the art, fogs a light sensitive emulsion. If the pigmented or laked layer is held sufficiently far away from contact with the emulsion, no differential impression is observable. Now it is evident that if such pigments be employed in making up an ink for impressing a photographic wrapping paper, which will frequently contain a black or red dye for producing opacity to light-the former generally being in direct contact with the film support or gelatin coating thereon and the latter, particularly when used in roll films, will be wound -up in contact with the light-sensitive emulsion-that the uniform veiling action, partly due to the paper itself and partly due to the dye or pigment used in the paper will be locally reduced, so that undesirable off-setting effects will result on the developed film, and experiments show this to be the case.

We have found a method for the preparation of paper, cloth, organophil cellulosic sheet or other wrapping materials for photographic or other light-sensitive goods whereby the disadvantages resulting from the use of dissimilar dyes may be obviated. It consists as usual in loading 'the paper or coating thereon a pigment to make the paper opaque to light and, subsequent to this preliminary preparation, coating the paper with a second pigment which may or may not have a contrasting color to the first pigment but which has substantially the same catalytic effect with regard to production or destruction of hydrogen peroxide as does the first pigment (namely that in the paper) and, therefore, the same fogging or anti-fogging effect upon light-sensitive coatings as does the first pigment applied to the material. In some instances it has been found desirable to impregnate the paper while in the formative stage with a size and a pigment, and subsequent to its fabrication in sheet form, printing thereon with a pigmented ink (to produce markings or identifications) which comprises as a hinder the size used in first impregnation of the paper. The pigment in both cases is, of course, of different colors, but their activity with regard to hydrogen peroxide and consequently their action on the photographic light-sensitive emulsion will be substantially the same, whether it be a fogging or anti-fogging action upon the lightsensitive layer. In place of impregnating the fibers-of the paper in its preliminary preparation, this sizing material may be applied to the surface thereof with equally good results.

The size which may be utilized for-both the preliminary treatment of the paper as well as for the binder in the suspension of the second pigment may comprise any type of sizing or binding material which has, at the most, but slight action upon the light-sensitive emulsions. It is immaterial whether this slight activity be of the fogging or anti-fogging nature. The sizes which we have found useful have been engine size, such as purified rosin sizing plus starch, or tub sizing, e. g., animal size. Many other sizes having the above qualities may be used, and such will come within the scope of this invention.

The pigments which we have found suitable comprise a large number of both the organic and inorganic pigments, and in speaking of pigments in this application, we imply the broad dictionary meaning of that word, including all the coloring media. In selecting the pigment, whether it be for the preliminary treatment of the paper or the subsequent treatment, it must be borne in mind that here again the activity of this pigment toward the light-sensitive coating should be relatively slight. It does not matter whether this activity be of the fogging or desensitizing nature. It is advantageous, however, in order that the developed film or other sensitive surface be not deleteriously affected that the pigment has comparatively slight activity in this regard. We have found the following substantially pure pigments give similar catalytic effect with regard to hydrogen peroxide and, therefore, the same antifogging effect under the specified conditions.

Manganese di-oxide. FerncJerrous-cyanide. Grapbitie carbon.

Prussian blue Aquadag artificial g r a p b (blac Calcium alizarine lake (red brown).

Calcium alizarinate.

The following give substantially the same rate of autoxidation and production of hydrogen peroxide when associated with paper fibers and consequently similar fogging action under like conditions:

I\ rune Chemical character Fugging pigments:

Carbon blacks Tuscan red Fogging dyes:

Methylene blue Tetraniethyl diamino-diphennz-thioniuni chloride.

Zinc double chloride of para 1mm tetramethyldiamino tri phehyl-cnrbinol anhydride.

Not listed.

Sodium salt of diphcnyl-diazo bis-S- amino l -naphthol 3:6 disulphonic Victoria green Diazino black Niagara blue acid.

Sodium salt of 6 sulph-l-amino-a-naphthalene-azo-benzene-azo-3-sulpho-lnaphthol-7-azo-m-phenylcnediamine.

Sodium salt of disulphonic acid of m-hydroxy-tetra-ethyldiamino-triphenylcarbinolanhydride.

Sodium salt of 4-sulpho-a-napbtbaleneazo-p-naphthol.

Mixture of diamino-phenyl-ditolazomurn chloride diamino-o-tolyl-ditolazonium chloride.

Pontarnine last black.

Xylene blue National fast red S. cone.

Erie fast scarlet S B A.

Sairanine G In the preparing of papers or other materials, as described in our preferred process hereinabove disclosed, in some instances it may not be necessary to have a binder present in the pigment which is applied to the sized and pigmented paper, although this expedient will not in all cases give the optimum results as it is well known that papers will generally not hold as much pigment or dye when it contains little or no size. It is desirable that the pigments have the same activity and likewise can be held in sufiicient amounts by the paper while the amount of pigment of either type over a given area of the paper has substantially equal density. Should this process be employed, the size of the paper should not harmfully act on the light-sensitive emulsions.

It will be evident from the above disclosure that we are not limited to any particular manner of preparing the paper or other material or applying thereto the sizing pigment or the contrasting pigments, the degree of color contrast desired governing the quantities of the dyes and the necessary size and binder used. Variations, therefore, in the quantity of these materials or in similar pigments having equivalent activity, be it of the fogging or anti-fogging nature, will come within the scope of this invention and in no way sacrifice any of its advantages.

What we claim as our invention and desire to be secured by Letters Patent of theUnited States 1. Process for preparing papers which are intended for contact with light-sensitive materials which comprises loading the paper base with a light excluding pigment and subsequently locally applying to the paper an ink in the form of identification marks, which ink comprises a contrasting pigment, both pigments having the same catalytic effect with regard to the hydrogen peroxide produced by'the autoxidation of materials comprised in the finished paper.

2. Process for preparing papers which are intended for contact with light-sensitive materials which comprises loading the paper with a size and a light excluding pigment and subsequently locally applying to the paper an ink in the form of identification marks, which ink comprises a contrasting pigment and comprises, as a suspending medium, the same size as used in the paper, both pigments having the same catalytic effect with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper.

3. Process for preparing papers which are intended for contact with light sensitive materials which comprises loading the paper base with a size and a light-excluding pigment and subsequently locally applying to the paper an ink in the form of identification marks, which ink comprises a contrasting pigment and a suspending medium therefor, the total catalytic effect of the size and pigment in the paper base with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper being the same as the total catalytic effect, with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper, of the suspending medium and pigment comprised in the ink. V

4. A photographic wrapping paper intended for contact with light sensitivematerials, comprising a paper base loaded with a light-excluding pigment and identification marks thereon composed of ink which comprises a contrasting pigment, both pigments having the same catalytic effect with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper.

5. A photographic wrapping paper intended for contact with light sensitive materials, comprising a paper base loaded with a size and a light-excluding pigment, and identification marks thereon composed of ink which comprises a contrasting pigment and, as a suspending medium, the same size as is used in the paper, both pigments having the same catalytic effect with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper.

6. A photographic wrapping paper intended for contact with light-sensitive materials, comprising a paper baseloaded with a size and a light-excluding pigment, and identification marks thereon composed of ink which comprises a contrasting pigment and a suspending medium therefor, the total catalytic effect of the size and pigment in the paper base with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper being the same as the total catalytic effect, with regard to the hydrogen peroxide produced by the autoxidation of materials comprised in the finished paper, of the suspending medium and pigment comprised in the ink.

7. Process for the preparation of papers which contact with light-sensitive materials which comprises loading the paper with sizing and artificial graphite and subsequently applying thereto a color coating comprising sizing and manganese dioxide.

8. A photographic wrapping paper loaded with sizing and artificial graphite and marked with a color coating comprising sizing and manganese dioxide.

. SAMUEL E. SHEPPARD.

HERBERT J. DIETZ.