US2326056A - Antihalation film - Google Patents

Description

g- 1943 G. F. NADEAU ET AL 2,326,056

ANTIHALATION FILM Original Filed March 4, 1941 EMULSION. susa/we LA YER.

LLULOSE ESTER SUPPORT AN T/HALAT/ON LA YER 0F CELLULOSE ORGAN/CAC/D D/CARBOXYL/C ACID ESTER,-CARRYIN6 A DYE.

Fig.2

UE SENSITIVE EMULSION. EEN SENSITIVE EMULSION. RED SENSITIVE EMULSION. JUBB/NG LAYER.

LOSE A CE TA TE PROP/DNA TE SUPPORT AN T/HALAT/ON LA YER OF CELLULOSE ACETATE PHTHALATE CONTAIN/N6 I4-28 ACE TVL AND 0-I6 PHTHAL YL, CARRY/N6 A DYE Gale E/Vadeau A/fred Q S/ack IN VEN TORS BY Q EMA/M A TTORNE YS antihalation purposes.

Patented Aug. 3, 1943 AN TIHALATION FILM Gale F. Nadeau and Alfred D. Slack, Rochester, N. Y., assignors to Eastman Kodak Company, v I Rochester, N. Y., a corporation of New Jersey Original application March 4, 1941, Serial No.

881,695. Divided and this application November 1, 1941, Serial No. 417,530

6 Claims.

This invention relates to a photographic film and more particularly to a film provided with antihalation layers.

This application is a division of Nadeau and I Slack U. S. Patent 2,311,073, granted February 16, 1943.

Coatings on the backs of films containing a dye or a superficial dye layer removable in photographic processing solutions are well known for Less well known are antihalation layers which are designed to be nonremovable. The disadvantages of the removable types of coatings are the tendency of some coatings to deposit sludge in processing solutions, the tacky nature of some coatings, the known thermoplastic qualities of other coatings which are in general undersirablaand furthermore, in the case of certain resinous coatings their tendency to form insoluble products with the antihalation dye. been designed to avoid these difiiculties and to prevent the penetration of the dye into and the consequent staining of the support. The success or ths practice depends upon the selection of a material, for the dye carrier, which is, sufli ciently permeable to processingsolutions, yet not soluble, that the dye giving antihalation protection may be completely discharged when desired.

The object of the present inventionis to provide a photographic film with a carrier for an Non-removable antihalation layers havea light sensitive layer adhesively joined to the support by means of a subbing layer.

Fig. 2 represents a multi-layer color film provided, on one side ofa subbed celluloseacetate propionate support, with emulsion layers sensitive to red, green and blue light, and on the opposite side, a cellulose acetate phthalate antihalation layer containing a dye.

antihalation dye, said carrier being permeable to, but not soluble in, photographic processing solutions. Other objects appear hereinafter.

We have found that a cellulose organic acid dicarboxylic acid ester containing substantially 4-8 acyl groups per C24 cellulose unit, of which not more than one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups of less than five carbon atoms, accomplishes our objectswhcn used as an antihalation layer in conjunction with a dye.

The general method we employ is to coat a photographic support with an emulsion, joining said emulsion to the support by means of suitable subbing layers.

the other side of the support. We may vary this procedure by applying the antihalation layer between the light sensitive emulsicn layer and the support. The antihalat. on layer. may also be coated before the emulsion layer.

Fig. 1 represents the general method of applying an antihalation layer and a dye to the back of a film support provided on the front side with We then coat a water-permeable cellulose ester layer and a dye layer onto containing less than 4 acyl groups or more than one phthalyl group D61.C24 cellulose unit are too soluble in photographic processing solutions to be of use in the manner of our invention. Likewise, those esters containing more than 8 acyl groups are too impermeableto be used in our invention. It is obvious that we contemplate, the use of other cellulose organic acid dicarboxylic acid esters, such as cellulose acetate propionate phthalate, cellulose acetate butyrate phthalate, cellulose acetate succinate, etc., the acyl content of which is of the order described.

In designating the cellulose esters of our invention in terms of acyl groups, we use the expression substantially.

esters which are useful fall within the range approximated by those esters having 4-8 acyl groups C24 cellulose unit Thus, cellulose acetate phthalate containing more than about 14 per cent phthalyl, in addition to about 7 acyl groups per C24 unit is too permeable to photographic developing solutions to be ofuse in our invention and this phthalyl content corresponds to about 1 phthalyl group per C24 unit of cellulose. We use a C24 unit as the basic cellulose unit in order to avoid expressing the dicarboxylic acid acyl content of an ester in fractional terms in respect to the aliphaticmonobasic acid acyl content.

Several types of supports may be provided with the antihalation layer of our invention. Cellulose esters such as cellulose acetate or cellulose nitrate, or mixed esters of cellulose, such as cellulose acetate propionate and cellulose acetate butyrate, and opaque supports such as pa- This is due. to the fact that in analyzing our esters we find that those For in- .per, may all be so provided with .antihalation and methyl Cellosolve in suitable proportions.

We will now describe our invention with particular reference to the accompanying drawing.

As shown in Fig. 1 of the accompanying drawing a cellulose ester support is provided with .a subbing layer l2 which may be gelatin or other suitable material, and over this is coated the emulsion layer l3 which may consist of a silver halide and colloid, such as gelatin, 2. cellulosic On'the opposite side of the support is coated the antihalation layer II or resinous material.

of our invention containing a dye in the outer stratum.

Fig. 2 shows a multilayer color film wherein a cellulose acetate propionate support I0 is provided with the red, green and blue light sensitive emulsion layers I 4, l5, and I6 respectively, adhesively joined to the support by means of a subbing layer I2. On the opposite side of the support is an antihalation layer H consisting of a cellulose acetate phthalate, 14-28% acetyl and 0-14% phthalyl, containing a dye in the outer stratum. .a

The following example illustrates one method of producing a film according to our invention, said example being intended to merely illustrate our invention and is not to be taken as limiting the scope of said invention.

Example A film base of cellulose acetate propionate containing 16% propionyl and 29% acetyl is coated with a 3% solution of cellulose acetate phthalate, acetyl content and phthalyl 13%, in a mixture of 45 parts acetone and 55 parts of methanol. Over this layer is applied a fugitive type of dye such as Acid Blue 2R or a dye of Color Index No. 702N704, 705, or 707. The solvent mixture for the dye may vary over a fairly wide range, although a mixture of 90 parts of meth-- anol and 10 parts of water is generally satisfactory. On the other side of the support, now provided with an antihalation layer, is coated from solvent solution, a subbing layer consisting of a resin or a mixture of a resin and a cellulose ester followed by agelatin layer and a light'sensitive emulsion. layer. Resins containing subbing layers have been more fully described in a prior Patent U. S. 2,133,110, and others. A subbing solution, containing gelatin and which is suitable for coating a gelatin layer over a resin containing layer is also described therein. The film may be provided with differentially light-sensitive emulsion layers which may be sensitized in the natural order as shown in Fig. 2 ofthe drawing, or sensitized in the natural order and colored complementary to the sensitivity as desired. A filter dye may be incorporated in one of the layers such as the blue sensitive layer in order to screen the lower layers from radiations which they are not intended to record. Also, there may be interposed between the emulsion layers a layer designed to receive a sound record or this record may be printed in one of the emulsion layers. Itis obvious that we may reverse or vary the order of deposition of the layers on the support as in an alternative method we coat the emulsion layers on the support before the antihalation and dye layers.-

The photographic elements described are used in any of the well-known processes designed to record an image in black-and-white or color. After exposure of the materials to an image the elements are usually developed t a negative and during this development or in a subsequent fixing treatment the cellulose ester antihalation layer becomes sufiiciently swollen to allow the penetration of the constituent removing the antihalation dye, but the cellulose ester of the anti halation layer is not dissolved.

While we have described the use of permeable cellulose esters, in antihalation layers, and this is the preferred embodiment of our invention, it is evident that any process requiring a water permeable, but not soluble layer, with or without a dye, may be served by the materials of our invention. Such processes are those of the photographic type which use sensitive films containing light filtering layers, the dye of which is to be removed at some stage in the processing treat-. ment.

The materials and examples of the present specification are illustrative only and it is to be understood that numerous methods and ingredients may be used Within the scope of the present description, and that the scope f our invention is to be taken as limited only by the scope of the appended claims.

What we claim is:

1. A photographic element free from halation which comprises a support provided with a light sensitive emulsion layer, and an antihalation layer of a water-permeable cellulose ester containing substantially 4 to 8 acyl groups per C24 cellulose unit, of which one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups of less than live carbon atoms, said layer carrying a light-absorbing dye.

2. A photographic element free from halation which comprises a support provided with a light sensitive emulsion layer, and an antihalation layer of, a water-permeable cellulose ester containing substantially 4 to 8 acyl groups per C24 cellulose unit, of which one is a phthalyl group and the remainder are aliphatic monobasic acyl groups of less than five carbon atoms, said layer carrying a light-absorbing dye.

3. A photographic element free from halation which comprises a support provided with a light sensitive emulsion layer, and an antihalation layer of a water-permeable cellulose ester containing substantially 4 to 8 acyl groups per 024 cellulose unit, of which one is a phthalyl group and the remainder are acetyl groups, said layer carrying a light-absorbing dye.

4. A photographic element free from halation which comprises a support provided with a light sensitive emulsion layer, and an antihalation layer of a Water-permeable cellulose ester containing, per C24 cellulose unit, substantially one phthalyl group and seven acetyl groups, said layer carrying a light-absorbing dye.

t 5. Aphotographic element free from halation which comprises a cellulose acetate propionate support provided with a light sensitive emulsion layer, and an antihalation layer of a water- 6. A photographic element free from halation which comprises a support provided with a light sensitive emulsion layer, and an antihalation layer of a water-permeable cellulose aliphatic monobasic organic acid-dicarboxylic acid, ester containing substantially 4 to 8 aliphatic monobasic organic acid acyl and dicarboxylic acid acyl groups per C24 cellulose unit, of which not more than one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups of less than five carbon atoms, said layer carrying a light-absorbing dye.

GALE F. NADEAU.- ALFRED D. SLACK.

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