DE1182526B - Image-receiving layer for a photographic light-sensitive material for color diffusion transfer processes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: G 03 c

German class: 57 b -14/02

Number: 1182 526

File number: J 24517IX a / 57 b

Filing date: October 4, 1963

Opening day: November 26, 1964

The invention is directed to an improved image receiving material for dye diffusion transfer processes, wherein an image-receiving layer containing polymers is hardened by novel hardening agents.

The invention relates to such color diffusion transfer processes, in which a layered photosensitive material is exposed and a latent image is thereby generated in it. That latent image is developed, while at the same time and under control of this development an image-correct one Distribution of diffusible, color-producing materials is formed. At least part of this Diffusible color-producing substances is processed by means of an alkaline aqueous developer liquid transferred to an overlying image-receiving layer to form a color image thereon. An example of such methods is found in U.S. Patent 2,983,606, which includes dye developing agents (i.e. dyes which can develop exposed silver halide layers) as coloring substances. Another one For example, see U.S. Patent 2,647,049, which describes dye developing agents used to develop the latent image and dye couplers as coloring substances be used. In the processes according to US Pat. No. 2,774,668, complete, pre-formed Dyes which are capable of coupling are used as coloring substances. Further Examples are the methods of U.S. Patent 2,968,554.

The image receiving layers generally used in these processes contain a translucent or transparent support covered with an image-receiving layer of a dyeable Material is coated, which is permeable to an alkaline aqueous developer solution. Previously attempts were made to use film-forming materials such as polyvinyl alcohol and types of polyamides, i.e. polyamides such as N - methoxy - methylpolyhexamethylene - adipic acid amide to be used as dyeable substances. at A preferred image receiving layer has been poly-4-vinyl-pyridine and in particular a mixture of poly-4-vinylpyridine and polyvinyl alcohol is used. This is described in German patent specification 1,138,319.

The image-receiving layers described above have been found to be particularly useful in color diffusion transfer processes employing dye developing agents. The improvements are particularly evident when making an image-receiving layer for a photosensitive
photographic material for color diffusion transfer processes

Applicant:

International Polaroid Corporation,

Jersey City, N.J. (V. St. A.)

Representative:

Dr.-Ing. F. Wuesthoff,

Dipl.-Ing. G. Pulse and

Dipl.-Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,

Patent Attorneys, Munich 9, Schweigerstr. 2

Named as inventor:

Lloyd David Taylor, Everett, Mass. (V. St. A.)

Claimed priority:
V. St. v. America 8 October 1962
(229 194)

azo and anthraquinone dye developing agents are used. The dye developing agents are, as mentioned above, compounds that are in the same molecule both the chromophore System of a dye possess as well as halogen silver can develop. You can also use it as a Dyes are designated which are silver halide developing substances. Particularly useful Dye developing agents are those in which the developing property is due to the presence a benzenoid group (i.e. an aromatic group, especially a benzene group containing Group) is given. A preferred benzenoid developing group in these compounds is a Hydroquinonyl residue. Examples of typical dye developing agents can be found in that mentioned above U.S. Patent 2,983,606 and in other references cited in this patent. In color diffusion transfer processes using dye developers, one is exposed Silver halide emulsion developed in the presence of the dye developing agent, and as a result During this development, the dye developer substance in the developed areas is oxidized and essentially immobilized. At least part of the immobilization process is likely

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at least in part due to a change in the solubility properties of the dye developing agent in terms of oxidation and especially with regard to its solubility in alkaline solutions be due. The dye developer substance is in unexposed and partially exposed areas of the emulsion unconverted and diffusible and thus results in an image-appropriate distribution of non-oxidized dye developing agent which is dissolved in the liquid developing solution as a result the point-by-point exposure of the silver halide emulsion. At least some of the picture-fair ones Distribution of non-oxidized dye developer substance is achieved by swelling onto an overlying one Transferred the image-receiving layer, of which transfer essentially the oxidized Dye developer substance is excluded. The image receiving layer receives from the developed one Emulsion a diffusion of the non-oxidized dye developer substance which varies according to the depth, without noticeably destroying the image-justified distribution on it, thereby creating a gives an inverted or positive color image of the developed image.

The presence of a water-sensitive film-forming material in the image-receiving layer results often swelling of the film during the development process, thereby destroying the image. This water sensitivity can be achieved by curing or crosslinking the polymer before photographic processing with aldehydes such as glyoxal can be reduced or eliminated. While however, the curing of the polymer can cause such substances to have photographically undesirable side effects such as loss of gloss, decreased image density and adhesion of the developer formulation to the receiving layer. To prevent this adhesion of the developer solution, an additional coating or layer can be applied but this so-called stripping layer and the introduction of an additional one can also be used Step in the production of the image-receiving layer interferes with the transfer of the dye developer substance make noticeable on the receiving layer, as is the case with some hardening or crosslinking agents in a reduction in the total Image quality of positive images can be recognized.

It has now been possible to find a substance class that, surprisingly, most if does not even eliminate all of the above-mentioned problems by, on the one hand, the polymer in the Receiving layer light up to the desired level of water-insensitivity and without loss of gloss can be hardened and on the other hand the receiving layer clean of its overlying layer can be stripped off without adhesion to the developer solution and without an additional stripping layer on the receiving layer would be necessary and without adverse effects on the stability of the transmission color image.

The results enumerated above can be achieved by adding receiving layers which Contain polymers with - OH, - NHa or - SH groups, with acrolein or acrolein condensates treated. With the term "acrolein condensates" are products of the reaction between acrolein and meant a compound which has at least one aldehyde group and at least 1 active hydrogen atom which can add to the double bond in acrolein. Such Reactions are known and z. B. in the work "Acrolein", Verlag John Wiley & Sons, Ine, New York, N-J., Described. The acrolein condensates suitable as curing agents within the scope of the invention are low molecular weight substances that preferably have an average molecular weight from 120 to 600 and contain no more than three carbonyl groups per molecule.

Examples of compounds that react with acrolein and form acrolein condensates are the following substances:

CH ₂ - CH - C = O

OH OH H OCH ₃ Glyceraldehyde - CH ₂ - C - H CH ₃ O H-C-

CH ₃ O OCH ₃

1,1,3,3-tetramethoxypropane

CH ₃ CH ₂ O OCH ₃

HC-CH ₂ -CH

I!

CH ₃ O OCH ₃

1,1, S-trimethoxy-S-ethoxypropane

CH ₃ CH ₂ O

OCH ₂ CH ₃

HC-CH ₂ -CH

I I

CH ₃ CH ₂ O OCH ₂ CH ₃

1,1,3,3-tetraethoxypropane

As mentioned, acrolein condensation reactions are generally known. Such reactions can carried out by mixing 2 moles of acrolein or dimeric acrolein and 1 mole of that compound containing at least one aldehyde group and at least 1 active hydrogen atom, which can add to the double bond in acrolein. The reaction product can then be diluted, e.g. B. to a 50 weight percent aqueous solution, or it can be used directly for curing of the image-receiving layers can be used without thinning.

The following information is used to explain the production of an acrolein condensate suitable as a hardening agent for the purposes of the invention without thereby restricting the invention.

Attempt a

11.2 g acrolein, 15.2 g 1,1,3,3-tetramethoxypropane and a drop of phosphoric acid were mixed in a beaker; Were 26.4g of water then added to give a 50 weight percent aqueous solution.

The term “acrolein” used here is intended not only to _{mean CH 2} = CHCHO, propenal (acrolein), but also

CHO

Include acrolein dimer in both its monomeric and polymeric forms.

Examples of polymers which are suitable as curing agents according to the invention are polyvinyl alcohol, Gelatin, partial acetals of polyvinyl alcohol, as described in the German patent 1,133,977 are described, furthermore cellulose, cellulose derivatives and other carbohydrate polymers.

The novel hardeners to be used according to the invention are water-soluble and can therefore easily in image receiving layers by adding an aqueous solution of the hardening agent to the polymer solution be incorporated shortly before potting. As mentioned above, the hardening agent is preferred applied in a 50 weight percent aqueous solution, but the hardener can can also be used without dilution. The amount of curing agent to be used is related refers to the amount of - OH, - NH2 or - SH groups in the polymer.

But you can also first cast the polymeric receiving layer as a film, after which it is cured Treating the film with a solution of the hardening agent, e.g. B. by distributing, spraying or pouring on the solution onto the film or by dipping the film in a solution of the hardener.

The degree of cure desired is also a factor in determining the amount of to be used Hardening substance. It is therefore easy to see the amount of Curing agent is not decisive and varies according to the choice of the particular desired conditions in terms of the desired properties in the image-receiving layer.

In a preferred embodiment, namely when the image receiving layer is a mixture of Contains polyvinyl alcohol and poly-4-vinyl-pyridine in a weight ratio of 2: 1, 5% the 50% aqueous solution of the curing agent, based on the weight of polyvinyl alcohol, is used. The hardening agents can be used for the treatment of polymeric receiving layers either in diluted form Form or in concentrated form. Because of the easier handling the hardeners are usually applied as 50% strength aqueous solutions. The following examples explain the use of the curing agent for the invention:

example 1

To an aqueous solution containing 100 g of polyvinyl alcohol and 50 g of poly-4-vinylpyridine, based on dry weight, were added 10 g of a 50% strength by weight aqueous solution of a low molecular weight acrolein condensate having the following properties: average molecular weight 180 to 200; Viscosity at 6.65 cP at 20 ^° C .; Density 1.135 g / ml at 20 ⁰ C; pH 4 to 5; Carbonyl value about 1.20 equivalents / 100 g of solution; completely soluble in water and ether. The solution was then cast onto a coated film support to form a receiving layer.

Example 2

To an aqueous solution containing 100 g of polyvinyl alcohol and 50 g of poly-4-vinylpyridine, based on the dry weight contained 10 g of a 50 weight percent aqueous solution of acrolein given. The solution was then applied to a coated film support to form a Poured receiving layer.

Example 3

To an aqueous solution containing 100 g of polyvinyl alcohol and 50 g of poly-4-vinylpyridine, on dry weight based, contained, 5 g of dimeric acrolein was added. The solution was then on a cast with a coated film base to form a receiving layer.

Example 4

To an aqueous solution containing 100 g of polyvinyl alcohol and 50 g of poly-4-vinylpyridine on On a dry weight basis, there was 10 g of a 50% aqueous solution in percent by weight of an acrolein condensate which was prepared by reacting acrolein with 1,1,3,3-tetramethoxypropane in a molar ratio of 2: 1. The solution was then coated onto a Cast film base to form a receiving layer.

The new hardeners to be used according to the invention have proven particularly useful Proven to achieve particularly good results when using the alkaline aqueous developer solution with a cellulosic material, e.g. B. thickened with carboxymethyl cellulose or hydroxyethyl cellulose.

When using the new hardening agents according to the invention, it is possible to use the characteristic To avoid water sensitivity of image receiving layers on the polymer basis and at the same time the disadvantages, such as adhesion of the positive to the negative and loss of stability of the negative, to be avoided if it is stored in the presence of the image-receiving layer, so disadvantages that had to be accepted with many known hardening agents such as glutaraldehyde.

The outstanding properties of the hardening agents to be used according to the invention can be demonstrated prove by a simple experiment, in which one looks at the above-mentioned wiping properties served. The development of an exposed silver halide emulsion is carried out as long as the overlying silver halide emulsion is on the image-receiving layer, between the an aqueous alkaline developer solution distributed over both layers and the resulting sandwich-like Arrangement passes through a pair of pressure rollers with a pre-set gap. Hardeners do not appear to be useful if the image receiving layer is not without adhesion of the Developer solution can be stripped off to the image receiving layer. So to the effectiveness of the To determine hardeners, image-receiving

layers that have been treated with the curing agents, passed through a pair of rollers, their Gap is larger than is normally considered sufficient, resulting in the wiping properties being checked. The thicker the gap, the more likely it is that some of the developer solution will stick adhere to the image receiving layer. For example, it has been shown that a polyvinyl alcohol containing Image receiving layer that has been hardened with glyceraldehyde or malonaldehyde and through a nip was guided, the l ^ times so was as large as the usual gap (0.0102 cm), a substantial amount of developer preparation per se allowed to adhere, while a similarly cured polymer layer with a curing agent according to the invention, z. B. the acrolein condensate, which is produced by the reaction between acrolein and 1,1,3,3-tetramethoxypropane has been produced, could be stripped off cleanly and no adhesion of the developer preparation showed. The experiment described above quickly gives a useful measurement of the stripping qualities of polymeric receiving layers which have been treated with hardeners. It is it should be noted that image-receiving layers formed with the hardeners to be used according to the invention Treated have been found to be unusually satisfactory when attempting this were subjected.

Image-receiving layers produced according to the invention and especially those according to Examples 1 Up to 3 layers produced gave excellent results when compared to multilayer Negatives used which contained dye developing agents ven of the kind described in the U.S. Patent 2,983,606.

The image receiving layers of the invention are particularly useful for composite films, in a Polaroid land camera from the Polaroid Corporation, Cambridge, 39, Massachusetts, or in a similar camera are to be used, e.g. B. a camera as described in the U.S. Patent 435 717 are described. In general, such composite films contain a photosensitive one Layer, an image receiving layer and a tearable container containing an alkaline aqueous Contains developer solution. The layers and the container are assigned to one another that in the Develop the light-sensitive layer on top of the image-receiving layer and the container is torn and the alkaline aqueous developer solution between the superimposed Layers distributed. The arrangement and design of such containers in such films is general known and described, for example, in U.S. Patents 2,543,181 and 2,634,886.

Claims (2)

Patent claims: 1. image-receiving layer for photographic light-sensitive materials for color diffusion transfer process, Containing a light-sensitive layer, an image-receiving layer and optionally a tear-open container for a developer liquid, characterized in that the image receiving layer, which polymers with —OH-, —NH2- or - Contains SH groups with acrolein or a reaction product between acrolein and a Compound containing at least one aldehyde group and at least I active hydrogen atom, which is capable of adding to the double bond on acrolein, has been hardened is. 2. Image receiving layer according to claim 1, characterized in that it is with low molecular weight Acrolein condensates, preferably with an average molecular weight of 120 to 600 and has been cured with no less than three carbonyl groups per molecule. 409 729/335 11.64 θ Bundesdruckerd Berlin