US2143791A - Photographic stripping film - Google Patents

Description

Jane M 1939. ca. F. NADEAU 2,243,791

PHOTOGRAPHIC STRIPPING FILM Filed May 16, 193.6

am f EMULSION GELATIN SUB w ng/ :75 SUPPORT F 12 H N/TAATE oPAcETATE a 24 BARYTA COAT/N6 CONTAIN/N6 P P UPP RT EMULSION ER 5 o LAT/N SUB I PERMANENT SUPPORT GLUE AND 6L YC'ERINE ADHESIVE GELAT/N SUB C'ELLUL05E NI TRATE ORAC'ETATE R SUPPORT C'ELLULOSE NITRATE 0R ACETATE GELA-T/N EMULSION GELA TIN aus I4 PERMANENT SUPPORT SYNTHETIC RESIN PAPER suPPonr I gg g gg f PERMANENT SUPPORT /GLUEANDGDTffi/NEADHE$IVE flGELAT/N sua "2"i2 ll A HEAL" 2 CEUULOJEACUATE SUPPORT (mums 1w TRATE l6 GELAT/N cow/2mm EMULSION MANGANESE wax/12c GELAT/N 5u5 Z5 CELLUL 05E N/TRA 7E cm ULOSE m'rPA r: 505 g; POLYV/NYI. ALCOHOL PAPER SUPPORT INVENTOR.

ATTORNEYS amt 1.... m, 1939 i 1,143,791

um'rso' STATES; PATENT orslcs Gale r. Naomi. mam, N. 2., anignor, by

mesne assignments, to Eastman Kodak Ooma pony, Jersey City, N. 1., a corporation oi New Jersey Application my 18, 1936, .SeriaLNo. 0,127

' a Claim. 95-9 This invention relates to photographic stripe Fig. 2 is a sectional view of a similar type of ping film, that is, film in which the sensitive layer film having cellulose ester and gelatin layers apls carried on a temporary support from which it plied to the reverse side of the paper support. may be removed, together with a permanent sup- Fig. 3 is a sectional view of a stripping film in port layer, after exposure. I which a layer of synthetic resin is applied be- 5 A photographicstripping film 01' this type is tween the paper support and the adhesive layer. described, for example, in US. Patent No. 1,973,- Fig, 4 is a sectional view of a stripping film in 476 of Fordyce et 9.1. These films are used in the which a layer 01 a water-soluble synthetic resin photo-engraving and related arts where an image is applied between the paper support and the perlo is to be recorded and after development and fix manent'emulsion support. log, removed from the temporary support and Fig. 5 is a sectional view oi a film similar to aifixed to a transparent plate for the purpose of that shown in Fig. 1, but having an anti-halatlon making photo-engraving plates. The emulsions dye in the baryta coating of the paper temporary used are usually a type whichgive an image havsupport.

l5 ing a high degree of contrast. A frequent difli Fig. 6 is a sectional. view of a film similar to l5 culty encountered in this type of film is the presthat shown in Fig. 1 but having a transparent ence 01 areas of varying sensitivity. produced by cellulose ester temporary support and an antithe lack of uniformity of overlying layers or by halation backing layer. a

7 other factors, not fully, understood. This results The construction of the stripping film accordin the formation of undesirable lines and mottle ing to my invention will now be described by par- 20 on the negative. A method of overcoming these ticular reference to the accompanying drawing. undesirable factors was described in my pricr ap- As shown in Fig. 1, the support it, which is a plication, Serial No. 64,103, filed February 15, temporary support of paper or other suitable ma- 1936, in which Idescribed an adhesive layer havterial, is coated with a layer it of a cellulose ing a controlled hydrogen ion concentration so ester, such as cellulose nitrate or cellulose ace- 25 that the emulsion layer would not be adversely tate, or a mixed ester, such as cellulose acetate ailected. propionate. The composition of this ester is not The principal object of the present invention is critical. The cellulose ester is applied from a- 5 to provide an improved method for overcoming to 10% of the ester in solution in a suitable solthese difilculties and tor producing a stripping vent. This solvent may be a mixture of 85% 30 film in which the sensitive emulsion does not show methyl alcohol and 15% acetone, or pure acetone, areas of varying sensitivity. methyl Cellosolve or other solvent. Over this This obiectis accomplished by applying a layer ester layer ii there is applied a thin gelatin subof cellulose ester or 'syntheticresin to the temlayer I The composition of h a in solution 36 porary support and coating the adhesive over from which this layer is applied may be as 101- this cellulose ester or synthetic resin layer.' 122- lows:

perimentation has established the iact that much i Grams oi the above-mentioned difiiculty may be attrib- Gela I 1.2 uted to the unevenness and lack oi! uniformity o! Acetic acid h I 1.2

40 the adhesive layer. When the adhesive is ap: Acetone 5 7o 40 plied directly to the paper temporary support it Water 5 is difierentially imbibed by the paper stock. By Ethyl alcohol j 22.6

applying a layer of cellulose ester or synthetic resin over the paper stock between the paper and The adhesive layer II is' pplied n x Thi the adhesive layer, this absorption th adh layer may consistoi' a 10 .to 15% aqueous solution 45 sive by the paper is prevented, with th e ult oi water-soluble glue or a mixture of 8%1iquld that very muchless'adhesive need be used and a glue and 8% glycerine in 84% of water. The perunli'orm coating is obtained. manent support layer I4 is then applied over the In the accompanying drawing whlch'fol'mga, adhesive layer. This permanent support layer 50, part of the' present invention I have shown a nummay consist of cellulose nitrate or acetate or other ber of enlarged sectional views of stripping film cellulose ester. I preferv to use, however, a cellumade according to my invention. i lose nitrate" of low nitrogen content and high al- Fig. 1 is a sectional view of a stripping film cohol solubility. A cellulose nitrate of this comhav'inga layer 0! cellulose ester between the paper position should contain approximately 9 to 12% "supportaudtheadhesi'velayer. oinitrogenandhaveasolubilityinmethyl alco- 5| hol of 30% to 100% and a viscosity of 2 to 5 seconds by the dropping ball method. This cellulose nitrate should be water permeable in order to permit the water of the developing bath or other treatment baths to reach and penetrate the adhesive layer. In order to increase this water permeability, it is desirable to add certain materials, such as glyceryl Bori-borate (sold by 'Glyco Products Company, New York, N. Y.),

.mono-, diand tri-acetin, lactic acid, glycerin,

from a solution having the same composition as the gelatin layer I2.

Viscosity by the dropping ball method referred to above is determined as follows:

10 grams of 'dry nitrocelluloseare dissolved in 100 cc. of a mixture comprising by volume of methyl alcohol and 50% by volume of acetone at 25 C. Viscosity is measured by the time in seconds it takes for a steel ball having a diameter of A;th of an inch and weighing .1320 to .1340 grams to fall 15 centimeters through the nitrocellulose solution at 25C. in a tube having a diameter of 1.7105 centimeters.

As shown in Fig. 2 the paper support i0 is coated on one side'rwith the layers II, I2, I3, I4, I5 and I6 as described above. On the opposite side of the paper support I0 there is coated a layer I! of a. cellulose ester, such as nitrate or acetatewhich may have the same composition as the layer II. Over this layer I! there is coated a,

gelatin layer I8. The purpose of these layers is to prevent curling of the element prior to or during exposure and to prevent water absorption by Fig. 3 a layer of a synthetic resin which is not easily attacked by water is substituted for the cellulose ester layerapplied to the paper support. As shown in this figure the-paper support I0 is coated witha layer of a synthetic resin I9. This is applied from a 3 to 10% solution of the resin in an appropriate solvent, such as ethylene chloride, acetone, or a mixture of ethylene chloride and methyl alcohol or acetone and methyl alcohol. Over the resin layer I9 there is applied a thin protective layer 20 of a cellulose ester, such as cellulose nitrate. This layer is applied merely to prevent the resin layer I9 from sticking in the 1,586,803 and 1,710,825. A further type of resin which may be used is the polyvinyl acetal type.-

, I6, as previously described.

Among the synthetic resins which may be used in stripping filmaccording to my invention, a

great many materials are available. These in clude the polyvinyl esters. such as polymerized vinyl acetate which is shown, for'example, under, the tradename Gelva, the preparation of which is described in the U. S. Patent Nos. 1,241,733;

These resins are condensation productsot partially or completely hydrolyzed polyvinyl acetate in water. The advantage of a stripping film in gelatin sub layer' I5 andthe emulsion layer I6.

and an aldehyde, such as formaldehyde, acetaldehyde,'or butyraldehyde and are known as poly vinyl acetals. They are sold under various tradenames such as Formvar" and Alvar, the prep-v 351,082 and in U. S. Patent Nos. 1,955,068 and 1,990,399. A still further type of resin which I may use are the alkyd resins, which are condensation products of. a polybasic acid and a polyhydroxy alcohol. An example of this type of resin is Glyptal, which is a condensation product of glycerine and phthalic acid or phthalic anhydride. A still further type of resin is the group known as the Santolites which are condensatio'n products of formaldehyde with aromaticisulfonamides.

I have also discovered that the adhesive layer may be partially or completely eliminated and in its place a water-soluble resin, such as polyvinyl alcohol applied to the paper support. A film of this type is shown-in Fig. 4. As shown in this figure the paper support I0 is coated with a layer 2i of polyvinyl alcohol in a 3 to 10% solution in water. The concentration of this solution will be determined by the method of application and by the speed of the coating operation. A thin layer "22 of cellulose nitrate is applied over the polyvinyl alcohol layer". and is followed by a heavier layer 23 of cellulose nitrate or of cellulose acetate or other cellulose ester which constltutes the permanent support. This is followed by the sublayer I! and emulsion layer I6.

In the modification of my invention in which a water-soluble synthetic resin is used as the adhesive layer, it'is sometimes desirable to coat a thin layer of a water-soluble glue directly over the resin layer; This is coated as a very thin .layer, much thinner than where the glue is used as the only adhesive, and may be, for example, a 2% solution of glue containing 1% of glycerine which the glue layer isf'partially or completely eliminated is that the stripping time is considerably reduced since the water of the processing bath does not need to penetrate a heavy glue layer.

. As shown in Fig. 5 the film may contain an anti-halation dye to prevent reflection of light from the paper support. As shown in this figure the paper support I 0 has a baryta coating 24 containing the anti-halation dye. This anti-halation layer is coated with the cellulose ester layer II followed by the gelatin sub-layer I2, the adhesive layer I3, the permanent support layer I4, the

gelatin sub-layer I5 and the emulsion layer I6.

It is also possible to apply the cellulose ester intermediate layer used according to my invention to asupport layer of transparent material, such as a cellulose ester, instead of to the paper support; As shown in. Fig. 6 the cellulose acetate temporary support layer 25 is coated with a cellu lose nitrate or acetate layer II and this is followed by the gelatin sub-layer I2, the adhesive layer I3, the permanent support layer II, the

On the opposite side 01' the transparent temporary support 25 there may be coated an anti-halation layer 21 of gelatin containing manganese dioxide or other suitable anti-halation material, coated over a subbing layer 26 of cellulose nitrate or other cellulose ester. This anti-halation baclaing may, o course, be omitted. The advantages of a transparent temporary support layer are that the operator may view the negative during proccasing and determine the extent of the development. A film having a temporary s pport layer of a cellulose ester is light in wei t and not liable to breakage prior to use. i

A photographic stripping film having a cellulose layer between the temporary support and the adhesive layer has a number of important advantages. Such a film is free from emulsion diificulties, such as lines and mottle and also may be stripped from the temporary support more easily and quickly than with films used hitherto. Less adhesivemay be used and there is a consequent decrease in the stripping time since less water must diffuse through the layers to dissolve the reduced quantity of-adhesive.

Although I have described a certain sequence of layers in the stripping film according to my in-,

' loseester or synthetic resin layer between the temporary support and the adhesive layer, or the substitution of a water-soluble resin layer for the adhesive layer. The remaining layers are added in a manner well known to those in the photographic film-making art. It is known, for example, that a gelatin layer does not readily adhere to a cellulose acetate layer of every composttion, although the gelatin layer will adhere to a cellulose nitrate layer. In some cases it is necessary to use an additional layer between the cellulose acetate and the gelatin layerin order to secure satisiactory adherence. 'The paper support may also carry other layers, such as a baryta or dextrin coating or both., My invention is to be taken as limited only by the scope of the appended claims.

What Iclaim is:

1. A'photographic stripping film comprising a temporary support, a water-permeable cellulose ester permanent supporthaving a sensitive emulslon layer thereon, and between said temporary suhlwrt and said cellulose ester permanent support, separate layers of a water-insoluble synthetic organic colloidal material and a watersoluble adhesive, the former layer being adjacent the temporary support, and said layers adhering temporary support, a water-permeable cellulose ester permanent support having a sensitive emulsion layer thereon, and between said-temporary support and said cellulose ester permanent support, separate layers of synthetic resin and a wa- 5 ter-soluble adhesive, the former layer being adjacent the temporary support, and said layers adhering firmly in the dry state.

4. A photographic stripping film comprising a temporary support, a water-permeable cellulose ester permanent support having a sensitive emulsion layer thereon, and between said temporary support and said cellulose ester permanent support, separate layers of cellulose nitrate and a water-soluble adhesive, the former layer being adjacent the temporary support, and said layers adhering firmly in the dry state. i

5, A photographic stripping film comprising a paper support, a cellulose ester layer on each side of said paper support, and in order on one of said cellulose ester layers, a water-soluble adhesive layer, a transparent water-permeable permanent support layer, and a photographic emulsion layer, all of said layers adhering firmly in the dry state.

6. A' photographic stripping film comprising a paper support, a cellulose nitrate layer on each side of said paper support, and in order on one of said cellulose nitrate layers, a water-soluble adhesive layer, a transparent water-permeable permanent support layer, and a photographic emulsion layer, all of said layers adhering firmly in the dry state. 4

'7. A photographic stripping film comprising'a paper support, a cellulose ester and gelatin layer in order on each side of said paper support, and in order on one of said gelatin layers, a watersoluble adhesive layer, a transparent water-permeable permanent support layer, and a photographic emulsion layer, all of said layers adhering firmly in the dry state.

8. A photographic stripping film comprising a temporary support, a water permeable cellulose ester permanent support having a sensitive emulsion layer thereon, and between said temporary support and said cellulose esterpermanent support, separate layers of a water-insoluble cellulose ester and 'a water-soluble. adhesive, the former layer being adjacent the temporary support, and said layers adhering firmly in the dry state.

9. A photographic strippingfilm comprising a paper support, on one side of said paper support successive layers of cellulose ester, water-soluble adhesive, transparent water-permeable cellulose ester permanent support, and sensitive emulsion, and on the opposite side of said paper support, a 5; layer of an organic acid ester of cellulose.

GALE F. NADEAU.

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