DE1015682B - Light-insensitive image receiving layer for the silver salt diffusion process - Google Patents

Description

GERMAN

The invention relates to a method for producing positive photographic images in films, Plates and papers using the silver salt diffusion process.

According to the invention, the image receiving layer consists of a layer support, ζ. Β. a film, a slide, Plate or paper with a light-insensitive, water-permeable colloid layer that finely divided, individual solid particles of an inert substance with an average diameter not less than 1 ΐημ and not more than 10,000 ηιμ, the solid particles have a silane compound containing at least one silicon-hydrogen bond on their surface wear. This silane compound makes 0.1 to 100 percent by weight based on the total weight of the uncoated particles.

Various types of water-permeable colloids can be used as binders for those containing the silane compound coated particles are used including naturally occurring binders, z. B. gelatin, albumin, cein, agar-agar, alginic acid and casein and synthetic binders, e.g. B. polyvinyl alcohol, partially hydrolyzed polyvinyl esters, hydrolyzed ethylene-vinyl acetate copolymers, Polyvinyl acetate including sodium o-sulfobenzaldehyde polyvinyl acetal and benzaldehyde polyvinyl acetal; Polyglycuronic acid and carboxymethyl cellulose.

Suitable substances for the individual inert particles include white or colorless substances such as dense silica, inorganic silicates such as magnesium silicate, diatomaceous earth, sodium aluminum silicate and potassium carbonate, barium sulfate and titanium dioxide, etc., or colored or black Particles, e.g. B. carbon black, lamp black, etc.

The inert particles can be obtained by adding a solution in an inert solvent or a Dispersion of the silane compound to be coated into the finely divided particles. The amount used the silane compound should generally be between 0.1 and 100% of the total weight of the uncoated Particles. In the case of liquid silane compounds no solvent is required, and the inert particles and the liquid silane compound can be mixed in suitable proportions so that the particles with an intermediate 0.1 and 100 percent by weight based on the weight of the uncoated particles the silane compound are coated.

The particles coated with the silane compound can be applied by simply mixing them with an aqueous solution or dispersion of the water-permeable colloid or with a solution or dispersion of the same in an organic light-insensitive image-receiving layer
for the silver salt diffusion process

Applicant:

EI du Pont de Nemours and Company,
Wilmington, Del. (V. St. A.)

Representative: Dipl.-Ing. E. Prinz, patent attorney,
Graefelfing near Munich, Aribostr. 14th

Claimed priority:
V. St. v. America November 15, 1954

Russell Houston Gray, Red Bank, NJ (V. St. A.),
has been named as the inventor

see solvents being prepared. So that the coated particles easily within an aqueous Solution or dispersion of the water-permeable colloid can be dispersed, one uses expediently a wetting or dispersing agent in an amount of 0.1 to 100 percent by weight, based on the total weight of the inert particles coated with the silane compound. Appropriate means for this include saponin and the compounds described in US Pat. No. 2,400,532, namely: the oxyalkylene alcohol esters of hexitol ring dehydrogenation products, e.g. B. the polyoxyethylene sorbitan monolaurate, monostearate and monooleate, which contain two to twenty oxyethylene groups included in three chains; a salt of an alkyl substituted aryloxyalkylene ether sulfonate, e.g.

Sodium p-tert-octylphenoxyethoxyethsulfonate, described in U.S. Patent 2,600,831; Sodium dodecyl, tetradecyl and octadecyl sulfate and the dioctyl ester of sodium sulfosuccinic acid.
The new image-receiving layer has an excellent light-insensitive image-receiving layer for reverse transfer of soluble silver complexes from the unexposed and undeveloped parts of an immediately overlying light-sensitive layer consisting of silver halide and water-permeable colloid, as will be described in more detail below. The particles coated with the silane compound not only act as a core for a silver deposit in the light-insensitive, water-permeable colloid layer containing them,

709 '696/287

but they also accelerate this deposition. Because the coated particles do not go out of or into the Layer migrate into and on the surface of the image receiving layer containing such particles excellent picture dejected. As a result of the —SiH group in the silane compounds, which reduce the silver complexes to silver, a denser picture than if uncoated Particles (e.g. silica) can be used.

optionally removed by treatment with an aqueous solution or a fixative.

The invention will be better understood from the following non-limiting examples.

Sion layer of a film, a paper or a plate are brought into surface contact can. Other useful embodiments according to the invention

Example I.

To 1 liter of a 5 weight percent aqueous gelatin were 4.0 g of silica particles with an average Diameter of 0.015 μ added, which with

The image-receiving layer according to the invention has been coated with trichlorosilane, which is hydrolyzed to form only one type of the image-providing, non-photosensitive coating of (HSiO _{1> 5} ), the borrowed layer (ie which is not a photosensitive sub- η 1 or more and the Coating 15 to 20% of the punch, for example silver halide, bichromates and diazo, constituting the total weight of the coated particles, layer containing sodium compounds). These coated particles were expediently located at the top in the form of a layer, so that they were added by mixing in a high-speed mixer with a separate outer silver halide mixed ethanol dispersion. The received

Gelatin dispersion was applied to a sheet of paper to form a thin layer which was dried upset. Another sheet of paper has been made but has a photosensitive, 20 coated with a similar gelatin solution, which silver halide-containing, water-permeable colloid but no coated particles and one The layer on which the silane compound formed over control sample. The coatings were pulled inert particles containing light-insensitive dries.

borrowed, water-permeable KolloMschicht. The SiI- Separate Photographic Contact Printing Paper-

The halide emulsion layer has a colloidal emulsion layer in these samples, which have elements composed of silver chlorobromide gelatin, and have been treated with a binder which is relatively soluble in water compared to the positive image base layer on a film, so that it is exposed and the exposed element obtained, samples after the end of the image transfer are washed away the light-insensitive paper, which can be overdened. The lower layer can be relatively insoluble from the start, containing gelatin layers containing 30 drawn particles, or it can be chemically carried and samples of the no such particles containment hardened. When gelatin is chosen as the colloid
the underlayer can be coated with a gelatin hardener, e.g. B. chrome alum, formalin or
Dimethylolurea, to be cured. 35

When the image receiving layers according to the invention are used for image transfer by the silver salt diffusion process becomes a latent image in a water-permeable halogen silver collord layer by the usual method of exposure 40 with an objective field, e.g. B. an original scene, a reproduction or a photographic image. Either during or after development the latent silver image is well known

Way, an aqueous solution of a solvent for 45 with the developer-impregnated gelatin over the silver halide, e.g. B, sodium thiosulfate, wet elements removed from the developer, and triumrhodanide or sodium sulfite or mixtures, a sample of the exposed element of two or more of these compounds and the gelatin element were firmly brought into contact with the gelatin, preferably compressed into surfaces and held in contact for 10 minutes in the presence of noticeable actinic radiation while 50 others. After this time, the light-sensitive layer was intimately separated, fixed, washed and kept dry surface contact with the image-receiving layer until a small or large part of the undeveloped silver halide is dissolved out, which
z. B. takes 5 to 600 seconds. The 55
Silver complexes diffuse into the receiving layer,
which contains the coated particles and where the
Silane compound and the photographic developer
reduce the silver complexes and metallic silver
on the particles to produce an image
suggest which is the reverse image of the original
latent image is. The original silver halide layer is then removed. If z. B. the SiI overhalide layer on a separate film or

Tending light-insensitive paper were separated, each 1.5 minutes in a developer solution of Submerged at 20 ° C, which was obtained by mixing the following ingredients:

N-methyl-para-aminophenol sulfate .. 1.0 g

Hydroquinone 4.0 g

Sodium sulfite (anhydrous) 15.0 g

Sodium carbonate (monohydrate) ... 22.5 g

Potassium bromide 0.63 g

Water up to 1.0 1

Sodium thiosulphate (crystalline) 1.0 g

The exposed paper samples were collected together

net, and the following results were obtained:

Image receiving layer

Gelatin (no particles
containing)

Gelatin + coated
Particle

Received positive image

very pale

strong image with clean white areas

Example II

Each 1 g of a silane compound over paper, the two elements are simply 65 pulled silica particles of type a), b) and c) in separated. If the silver halide is different in a form of an ethantol prepared as in Example I. soluble layer, the dispersion became more aqueous to samples of 250 ecm each whole original layer washed away. About 5 percent by weight gelatin added which of the 1.6 ecm saponin containing a deposited silver image and 1.5 ecm of a 10.25 weight per image receiving layer Remaining stains may contain an aqueous solution of chrome alum.

a) silica particles with an average diameter of 0.015 μ, coated with (SiHO _li5 ) ", where η is a positive integer of 1 or more and the silane compound makes up 15 to 20 percent by weight of the coated particles;

b) coated particles similar to a) prepared by coating "Si-O-Lite" particles with (SiOH ₁₅ ) "(manufactured by Mallinckrodt Chemical Works);

c) Silica particles coated with 5 percent by weight HO [(C _? H ₅ ) HSiO] „H, where η can be between 6 and 20. The gelatin dispersions obtained were applied to a barium oxide-coated paper and the coatings were dried. The gelatin dispersion containing no coated silica particles was applied to the same type of paper and the coating was dried.

Photographic papers with a silver chlorobromide gelatin emulsion layer were exposed to a positive image located on a film, and the papers were then together with samples of the Image receiving papers a), b) and c) separately, each 1.5 minutes, as described in Example I, in one Developer solution immersed at 20 ° C. The exposed impregnated samples of the photographic Paper and impregnated samples from a), b) and c) were firmly pressed together with their gelatin surfaces and kept in contact with each other for 10 minutes. Then the layers were separated and dried with the following results:

Image receiving layer Received positive image Gelatin (no particles) pale picture Gelatin + coated Particle a) strong blue-black image Gelatin + coated Particle b) the same Gelatin + coated Particle c) the same

Each of the images on the papers in the table above showed the same stains. With similar attempts however, the stains in each image support layer were removed by making the positive prints Fixed for 3 minutes in a fixing bath obtained by mixing the following ingredients.

Sodium thiosulfate · 5H ₂ O 240 g

Sodium sulfite, anhydrous 15 g

Borax-1OH ₂ O 18 g

Glacial acetic acid 12 ecm

Potassium Alum · 24H ₂ O 20g

Water up to 11

washed the treated elements with water and dried.

Example III

1 g of coated silica particles in ethanol solution, as described in Example I, became one 250 ecm sample of medium viscosity polyvinyl alcohol (almost completely hydrolyzed polyvinyl alcohol) Ethanol and water in a ratio of 5: 5: 90 percent by weight added, with the solution contains 6.25 ecm of a 25 percent by weight aqueous solution of cetyl betaine. The polyvinyl alcohol dispersion obtained was applied to a paper coated with barium oxide, and the obtained thin layer was dried. An identical polyvinyl alcohol solution, which no coated silica particles was coated with barium oxide in the same way Paper applied and the coatings dried as control paper samples.

Samples of lithographic film with a silver chlorobromide gelatin emulsion layer a cellulose acetate support were exposed in the manner described in Example I. The emulsion surface of the exposed samples was subjected to intimate contact with the coated surface of two papers described in the previous paragraph and with the coated papers described in Example II in a commercial processor brought, said developing device means to bring the surfaces into contact with one another and a developer solution at 20 ° C with the following composition:

Water of 51.7 °

Sodium sulfite (anhydrous)

Hydroquinone

Boric acid crystals

Potassium bromide

Sodium thiosulphate (anhydrous) ....

»Sterox« CD * (1/50, C ₂ H ₅ OH,
V / V)

1-pheniyl-5-mercaptO'tetrazole

(Ig in lOOOccm CH ₃ OH)

Sodium hydroxide

Cold water except for

* A polyethylene ester of a tall oil acid.

After 20 seconds of contact time, the lithographic film samples were separated and the gelatin and polyvinyl alcohol image-receiving layers were made in the fixing solution described in Example II Treated for 3 minutes and then dried with the results given in the table below:

750 ecm ecm 45.0 G ecm 16.0 G G 5.5 G 1.01 2.0 G 15.0 g 5.0 6.0 24.0

Image receiving layer Received positive image Gelatin (no particles) pale gray Gelatin + coated Particle a) Brown Gelatin + coated Particle b) Brown Gelatin + coated Particle c). black Polyvinyl alcohol (no particles) pale gray Polyvinyl alcohol + over pulled particles a) ... Brown black

Example IV

The procedure of Example II was repeated except that that served as a control Gelatin coating contained uncoated silica particles with the same mean diameter. Man achieved the following results:

Image receiving layer Received positive image Gelatin + silica particles (not over pulled) weak Gelatin + coated Particle a) of Example II strong

The invention is of course not limited to the use of those mentioned in the preceding examples

Silane compounds still refer to those in these examples specified amounts are limited. A large number of other silane compounds, including at least one Silicon-hydrogen bond can be used equally.

The usefulness of any silane compound containing a silicon-hydrogen bond, can be determined by testing whether it or its hydrolysis products have a reducing effect Have an effect on silver halide or form nuclei for silver precipitation. The mechanism or the theory why the silane compounds act as chemical sensitizers for silver halide emulsions work is not entirely clear. However, it is believed that the silicon-hydrogen bond is an alkaline initiated hydrolysis must be capable of what in the following equation for one according to the invention to be used class of silane compounds is expressed.

OH-

-v R _n SiOH _4. , + H ₈ ,

R _n SiH ₄ - "+ HOH

in which R _{n is} hydrogen, halogen, e.g. Fluorine, chlorine and bromine, an alkyl of 1 to 30 carbon atoms, an alkoxy group of 1 to 30 carbon atoms, an aryl group, e.g. Phenyl, tolyl, naphthyl, etc., an aryloxy group e.g. B. phenoxy, naphthoxy, etc., a siloxy group or combinations thereof and η is 1-3. Other suitable specific silane compounds that may be mentioned are: alkylsilanes, for example methylsilane, dimethylsilane, trimethylsilane; Ethylsilane, diethylsilane, triethylsilane, n-propylsilane, butylsilane, alkylhalosilanes, dimethylchlorosilane, ethyldichlorosilane, diethylchlorosilane, propyldichlorosilane; Arylsilanes, for example diphenylsilane, triphenylsilane and mixed alkyl-aryl-silanes, e.g. B. ethyldiphenylsilane; Methyl-phenyl-silane and dihexyl-phenyl-silane; Alkoxy-, aroxy-, alkoxy-halogen- and aroxy-halosilanes, e.g. B. diethyloxysilane, methyldichlorodiethyloxysilane and phenoxysilane; cyclic and linear polymeric siloxanes, e.g. B. Cyclic tetrameric methylsiloxane and its linear analogues: HO [CH ₃ (H) SiO] ₄ H.

Hydrolysis products of the silanes listed above which retain a silicon-hydrogen bond can also be used.

Mixtures of two or more silane compounds can be drawn onto the particles, or it mixtures of particles coated with two different silane compounds in the aqueous, colloidal solution used to coat the image receiving layers. There can also be different types of coated with either the same or different silane compounds Carrier particles are used.

The amount of that coated with the silane compound used in the water-permeable colloid Particle can change within a wide range of amounts. A common range is between 0.1 mg and 100g to 100mg of the colloid. There can also be layers of the active silane compound coated particles are produced without a water-permeable colloid as a binder, by making the particles from a dispersion in a solvent which has a dissolving effect on the carrier Has an effect, e.g. B. applies acetone in the case of cellulose acetate to a plastic carrier. the Particles can be sprayed onto a carrier, the surface of which is heated to softening became. The particles can be pressed or embedded in this softened surface by means of a roller will.

Various types of supports can be used for the image receiving layers containing the particles coated with the silane compound. Suitable supports include films and plates made from cellulose derivatives, e.g. B. cellulose acetate, propionate, butyrate, acetate butyrate, and nitrate; high "'polymeric materials, such as nylon, polyvinyl chloride, a copolymer of vinyl chloride and vinyl acetate, polystyrene, polymethylene terephthalates, for example ^poly;.; ethylene terephthalate; thin aluminum foils, paper and cardboard, etc. Of course, various intermediate layers for anchoring the Layers should be present on the basis as is customary in the manufacture of photographic films and plates.

Any photographic processing solution can be used in the practice of the process Find. Suitable developers and solutions are at Mees, “The Theory of the Photographic Process "published by the Macmillan Company, New York (1946), pp. 338 to 369, and in particular P. 352.

The image receiving layers according to the invention are suitable for reproducing various images. So are they z. B. cheap for copying printed matter. In this case, an image receiving paper is used with a separate exposed film is used which contains a latent photosensitive silver halide image wearing. The image recording papers are particularly suitable for photographic with the direct achievement of Positive images. Though doing the recording paper and the photosensitive film or the photosensitive Paper are separate elements, but the development that takes place when the two come into contact becomes carried out with simultaneous reverse transmission.

An advantage of the invention is that it provides new and extremely practical light-insensitive image receiving films, Films, sheets and papers create which are economical to manufacture and easy to use are. The image receiving layers remain stable for a long time. They give denser images than they are achieved using uncoated particles. The coated particles can are prepared long before their application and do not require any storage to the exclusion of actinic Radiation. The preparation of particles coated with a silane compound is simple and cheap in contrast to the difficult production of the colloidal or complexes previously used Particle. Another advantage is that the size of the particles is slightly prior to application of the silane compound can be separated out, so that one of the many commercially available particles is a large one Selection of those with reproducible and controlled size can make. The one with the silane compound coated particles form dry powders which are easy to store and handle and have many other advantages, such as: B. easy control of the amount of active ingredient by changing the type and amount of silane coating.

Claims (7)

Patent claims: 1. Light-insensitive image-receiving layer for ^; the silver salt diffusion process, characterized by a sheet-like carrier with a. Ii; Layer of finely divided inert solid Tejlchejj. ^ j with a mean diameter between 0. OQf " and 10.0 μ, which are coated with a least one SiIicium-hydrogen bond-containing Süanverbindung containing 0.1 to lOO / represents from ⁰ "to the weight of the uncoated particles. 2. Image receiving layer according to claim 1, characterized in that the finely divided, with inert solid particles coated with the silane compound with a light-insensitive, water-permeable colloid layer in an amount of 0.1 mg to 100 g are mixed for 100 mg of the colloid. 3. Image receiving layer according to claim 2, characterized in that the colloid layer is the only image receiving layer in the element. 4. Element according to claim 3, characterized in that the carrier is paper. 5. Element according to claim 3, characterized in that the colloid layer is outermost. 6. Image receiving layer according to one of claims 2 to 5, characterized in that the finely divided, inert solid particles consist of silica (SiO ₂ ). 7. image receiving layer according to one of claims 2 to 6, characterized in that directly above the light-insensitive, water-permeable colloid layer a light-sensitive, relatively water-soluble silver halide-containing colloid layer is located. © 709 «96/287 9.57