US3821001A

US3821001A - Heat decolorizable antihalation layers of a vanadium complex of 8-hydroxyquinoline

Info

Publication number: US3821001A
Application number: US00248917A
Authority: US
Inventors: J Weber
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1972-05-01
Filing date: 1972-05-01
Publication date: 1974-06-28
Anticipated expiration: 1991-06-28

Abstract

A photosensitive element comprises a support, a light-sensitive coating, an alkali bleachable vanadium complex of 8hydroxyquinoline and a heat labile alkali precursor. An antihalation layer comprising a vanadium complex of 8hydroxyquinoline is bleached by heating the element to about 80*C to about 250*C in the presence of a heat labile alkali precursor.

Description

United States Patent [19] Weber June 28, 1974 HEAT DECOLORIZABLE ANTIHALATION LAYERS OF A VANADIUM COMPLEX OF S-HYDROXYQUINOLINE [75] Inventor: Joanne B. Weber, Rochester, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

[22] Filed: May 1, 1972 [21] Appl. No.: 248,917

[52] U.S. Cl 96/84 R, 96/76, 96/1 l4. 1, 1 96/52 [51] Int. Cl G03c l/34 [58] Field of Search 96/109, 84, 52,1 14.6 r

[56] a References-Cited UNITED STATES PATENTS 3,364,029 l/l968 Haetner 96/84 R 3,434,839 3/l969 McGuckin 96/52 3,531,285 9/l970 Haist 96/l09 R 57 Aas'nmc'r A photosensitive element comprises a support, a lightsensitive coating, an alkali bleachable vanadium complex of S-hydroxyquinoline and a heat labile alkali precursor. An antihalation layer comprising a/vanadium complex of '8-hydroxyquinoline is bleached by heating the element to about 80C to about 250C in the presence of a heat'labile alkali precursor.

14 Claims, No Drawings I HEAT DECOLORIZABLE ANTIHALATION LAYERS 11 ANAIZWMQ XIFL X 9F s itvriitoxvoumotms BACKGROUND OF THE INVENTION emulsion or to a layer under the emulsion or on the support opposite to the emulsion side. For example,

carbon black and other pigments, dyes, toned Carey.

Lea silver, and the like have been used. Some of these have been coated in binders which have been solubilized by alkaline solutions followed by washing away of the solubilized hinder or by physical removal. Vanadium complexes of 8hydroxyquinolines disclosed in Haefner et. al., U.S. Pat. 3,364,029 issued Jan. 16, 1968 as antihalation materials, become decolorized during normal photographic processing when the element is immersed in an alkaline solution.

Dry processed elements in which the photographic element is processed by heating require that the antiha lation layer must be destroyed by the application of heat alone since there is no convenient means to remove the antihalation layer. Typical dry processed elements are described in U.S. Pat. No. 3,041,170 issued June 26, 1962 and U.S. Pat. No. 3,418,122 issued Dec. 24, 1968. Efforts to provide such an antihalation layer using dye to produce a neutral layer coated underneath the emulsion layer have generally been unsatisfactory since it has been difficult to provide dye combinations which result in a neutral tone. In addition, residual color has been left by the dye products following processing of the heat sensitive element. Accordingly, there is a need for improved antihalation layers which may be decolorized by heat.

It has been desirable to find a material with a neutral color which would act as an antihalation material which could be added either to the emulsion itself or to an undercoating, but which could be decolorized with heat. However, such a material would have to be compatible with a light-sensitive coating such as a silver halide emulsion and should not appreciably affect the speed of the emulsion when utilized contiguous thereto.

SUMMARY OF THE INVENTION 1 have found that an alkali bleachable black vanadium complex combined with a heat labile alkali precursor can be decolorized by heat. I have found that,

according to the invention, an oxodi-(8-quinolyloxo-.

2 contains, either in the coating with the antihalation material or in an adjacent or contiguous coating, a heat labile alkali precursor such as those compounds described as activator precursors in Haist et. al., U.S. Pat. No. 3,531,285 issued Sept. 29, 1870.

One object of this invention is to provide an antihalation material which provides a light absorbing sub stance which can be decolorized by heat and remains decolorized. Another object is to provide a photographic element having an incorporated antihalation layer in which the light absorbing material can be decolorized by heat. A further object is to provide a heat decolorizable antihalation material which is compatible with a photosensitive silver salt layer and which does not have an appreciable effect on the speed of the silver, halide emulsion when used as an undercoat for antihalation purposes. A still further object is to provide a method of obtaining antihalation for a lightsensitive element'on the same side of the support as the silver salt emulsion. Additional objects will be apparent from the following disclosure.

DETAILED DESCRIPTION ln carrying out my invention, I employ a vanadium complex of an 8-hydroityquinoline as a heat decolorizable antihalation material in photosensitive materials processed by heat. The following generic formula illustrates typical vanadium complexes which can be used:

R can be the same or different and'represents l-I,

l Him H dra ClHzOH I at... L

ZOOH

Polymeric complexes may also be utilized for antihalation protection. For example:

OOH

5,5'-Methylene bis(8-quinolinol) yields the following complex-in which X represents an integer granter than Any bifunctional group that does not destroy the color of the pigment may be substituted for the CH in linking the two hydroxyquinoline rings.

A useful amount of from 5 mg to 2.5 grams per square foot of the vanadium oxinate may be employed in the undercoat. However, more or less of the material may be utilized depending on the density required and the ability to decolorize the material during the processing cycle.

Heat labile alkali precursors which are preferably used include those which are stable at temperatures normally encountered during conditions of storage, e.g., 20 to 45C. The pH of the aqueous'solution containing the alkali precursor should be no higher than about 7, in order to prevent decolorizing the vanadium complex prior to heating.

The combination of heat labile alkali precursor with the described vanadium oxinates result in a reduction in density at temperatures employed in the substantially dry heat processing of the element in a short period, usually less than about 8 seconds at temperatures above about C.

While some compounds including certain quaternary ammonium bases and other amino compounds'will decompose at temperatures employed in the present process, it will be appreciated that certain of these compounds are not alkali precursors as employed herein and are not satisfactory for photographic purposes. As indicated in US. Pat. No. 3,220,839, certain of such compounds provide unpredictable properties to photographic elements and processes. Therefore, the term heat labile alkali precursor as used herein defines those compounds which are substantially compatible with light-sensitive materials.

Examples of classes of alkali precursors of the present invention include guanidinium salts, such as diguanidinium glutarate, succinate, malonate, adipate, pimelate or itaconate and monoguanidinium malonate, succiante or trichloracetate.

Quaternary ammonium malonates, such as piperazinium malonate, piperidinium malonate, pyrrolidine malonate, N,N-diethylenediamine bismalonate, and N-isopropylcyclohexylamine malonate; amino acids such as 4- aminobutyric acid, 6-aminocaproic acid, glycine and DL-serine and certain heat cleavable hydrazide compounds having cleavable nitrogen to nitrogen bonds, such as benzhydrazide, isonicotinic acid hydrazide and N-methyl piperidinebenzimide have been found suitable. Other compounds which have been found suitable include certain oxazolidones, including oxazolidone and N-methyl oxazolidone.

Certain heat cleavable quaternary ammonium compounds which provide the desired properties, that is, which are heat activated within the desired time and temperature limitations to activate the alkali precursor employed, include certain compounds within the scope of British Pat. No. 998,949, such as guanidinium trichloroacetate. It will be appreciated, however, that the element, compositions, and processes of the present invention are directed to systems containing photosensi= tive silver salts and that such systems do not involve the same mechanisms as are set out in non-silver salt systerns, such as diazo systems as described in British Pat. No. 998,949.

Useful alkali precursors include cyclic carbonates derived from ethylene glycol, and especially a cyclic carbonate having the structure:

wherein X is a water-solubilizing, non-metallic, nucleophilic anion such as halogen, cyanide, cyanate, thiocyanate, azide, sulfide, and the like anions, and each of R,

R R and R are selected from the group consisting of alkyl having 1 to carbon atoms including aralkyl groups such as benzyl, phenethyl, and the like.

Because of the sensitive nature of certain photo graphic materials, care may have to be exercised in selection and addition of the salt having the nucleophilic anion. While quaternary ammonium halides are particularly useful for generation of base, some of them, particularly the bromides, are powerful silver halide complexing agents. The presence of halide, azide, cyanide, and cyanates may be detrimental in some form to the activity of the silver halide emulsion either greatly restraining development, or producing high fog levels at ambient temperature.

Additional heat sensitive salts which are useful include the readily dicarboxylated organic acids disclosed in Tinker et al US. Pat. No. 3,220,846 issued Nov. 30, 1965. 1

According to the invention, the alkali precursor is activated within a short period, that is a period of seconds, when the element in which it is present is exposed to temperatures of above about 50C preferably from 90C to about 260C. The temperature range at which the photographic element or composition containing these components is treated will be determined by various components of the emulsion, such as incorporated developing agents and other addenda, as well as the degree of development required. Under most conditions, it is desirable to employ temperatures well above 90C, typically above about 150C, and usually in the range of about 190C to about 260C. The higher temperatures significantly shorten processing time in most instances to a period of less than about 8 seconds and usually in the range of about 1 to less than about 5 seconds.

Generally heating according to the invention can be carried out by contacting the photographic element containing the alkali precursor with suitable heating means such as metal rolls, infrared radiation, heated plates and the like.

The concentration of alkali precursor will be influenced by the amount of vanadium complex employed. In general, the amount of alkali precursor should be sufficient to effect decolorizing at the temperatures employed. The precursor is present in an amount of about b mole alkali precursor per mole vanadium oxinate to about 5 moles per mole'vanadium oxinate. It is coated in an amount of about 2 mg to 10 g per foot square.

The described antihalation compounds of this invention can be employed in print-out photosensitive elements as described in Colt US. Pat. No. 3,418,122 issued Dec. 24, 1968. Such an element comprises a silver halide print-out niaterial of the type that is capable of being exposed to light to form a latent image that is chemically developable to a visible image and which latent image is incapable of being photodeveloped by uniform exposure to a visible image of substantial descrimination (e.g., Dmax Dmin less than .1 at temperatures up to 121C.

This print-out material, which normally would uniformly fog if uniformly exposed to light after an imagewise exposure can be used to prepare light-stable visible silver images by heating to temperatures of at least about 149C prior to the photodevelopment or photolysis step. The heating step represses the usual printing out of unexposed or non-image areas (Dmin), the original recording sensitivity of the silver halide being inactivated by such heating. The optimum temperature and time interval to which the silver halide print-out material is heated can be readily ascertained by one of ordinary skill in the art by simply modifying such variables until an image having optimum or desirable discrimina tion density is obtained'after photodevelopment. Temperatures of at least about 149C are utilized and preferably at least about 177C. The upper extremes of the heating conditions utilized in the process can also be readily ascertained by one of ordinary skill in the art,

such factors as the breaking down or charring of the support of the photographic element or the vehicle for the silver halide beingpractical considerations.

The initial imagewise exposure is to light in the spectrum range in which the silver halide is sensitive sufficient to form a latent image (invisible image) in the silver halide materials, but insufficient to cause the silver halide .to print out. Such an image exposure can be effected with high or low intensity light. Such exposure conditions can be readily ascertained and vary widely with the type of silver halide material utilized. The latent image so formed is capable of image with known photographic devloping compositions.

The final step in the process is a uniform or over-all exposure of the image-exposed and heated silver halide material to light in the spectrum range in which the silver halide was initially sensitive (typically about 2,5005,700 Angstrom units such as ordinary daylight, tungsten light, fluoroescent light, etc.). This step is a photodevelopment of photolysis step and is utilized to develop the latent image formed in the initial imagewise exposure to a visible silver image of substantial discrimination. Such photodevelopment can be carried out during or after the heat treatment step. The development of the unexposed or non-image areas is repressed by the aforedescribed heating step.

The silver halide print-out element contains unfogged silver halide grains formed in the presence of a trivalent metal ion in an acidic media, such silver halide preferably having a halogen acceptor contiguous to the trivalent metal containing silver halide grains.

In preparing such photographic materials, trivalent metal ions are used in the precipitation or formation of the silver halide. Silver halide crystals are formed with trivalent ions on the inside of the crystals, i.e., silver halide crystals with trivalent ions occluded therein. Typical suitable trivalent metal ions include those of bismuth, iridium, rhodium and the like. Bismuth ions are particularly useful. The trivalent metal ion can be suitably added with the water-soluble silver salt (e.g., silver nitrate) or the water-soluble halide (e.g., sodium or potassium iodide, bromide, or chloride) that are conventionally reacted to prepare or precipitate photographic silver halide. Likewise, the trivalent ions can be introduced into the silver halide precipitation vessel with a hydrophilic colloid such as gelatin. The trivalent metal ions can be added to the system as water-soluble inorganic salts, as organometallic materials, as complexes, or any other form of material that results in the availability of trivalent metal ions during the formation of silver halide. The amount of trivalent metal utilized can be widely varied, although at least about 1 l' and more generally 1 X 10' to 2, mole percent based on the silver halide is used.

In preparing the print-out silver halide with trivalent metal ions, the water-soluble silver salt and the watersoluble halide are reacted to precipitate the silver halide under acidic conditions. The pH of the silver halide precipitation is typically less than 6 and preferably less than 5. Such acids as phosphoric, trifluoracetic, hydrobromic, hydrochloric, sulfuric and nitric are typically.

,utilized in the silver halide precipitating media to maintain acidic conditions.

Suitable silver halides used in preparing the photographic elements include silver chloride, silver bromide, silver bromoiodide, silver chloroiodide, and silver chlorobromoiodide. The silver halide preferably contains at least 50 percent bromide, less than 10 percent iodide and less than 50 percent chloride on a molar basis.

The silver halide utilized is unfogged. Such silver halide contains no visible or developable latent image. The silver halide is sensitive to electromagnetic radiation such as light and X-ray.

A wide variety of halogen acceptors can be utilized in the silver halide systems. Such materials are well known to those skilled in the photographic art and art conventionally added to light-developable, direct print silver halide emulsions.

The described antihalation compounds can be employed in a thermographic element or composition containing a complex of silver as the photosensitive component, such as a silverdye complex. Such a ther- 'mographic element can comprise a support, a silverdye complex, a reducing agent for a silver salt, a source of a metal for physical development, especially a source of silver for physical development, such as silver behenate or silver stearate, and a binder, typically polyvinyl butyral. Suitable silver-dye complexes are described in US. Pat. No. 3,446,619 of Gilman et. al., issued May 27, 1969.

In one embodiment, the element or composition contains a catalyst for an image-forming combination, especially a photosensitive silver salt. A typical concentration range of photosensitive silver salt is from about 0.005 to about 0.50 mole of silver salt per mole of oxidizing agent such as per mole of silver salt of organic acid, e.g., per mole of silver behenate. A preferred catalyst is photosensitive silver halide, e.g., silver chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide, or mixtures thereof. The photosensitive silver halide can be coarse or fine-grain, very fine-grain silver halide being especially useful.

The photosensitive and thennosensitive elements used in the practice of the invention can contain antistatic or conducting layers.

Photographic silver halide emulsions, preparations, addenda, processing and systems can be used in the practice of this invention as disclosed in Product Licensing Index, Vol. 92, Dec. 1971, publication 9232, pages 107-110, paragraphs l-XVIlI and XX.

The following examples are included for a further understanding of the invention.

EXAMPLE 1 To a stirred solution of m1 of 10 percent gelatin solution at 40C is added a solution of 3 grams of 8- hydroxyquinoline in 50 ml of ethanol followed by a warm solution of 1.3 grams of sodium metavanadate in 25 ml of water. The pH of the solution then is lowered to between 5 and 6 by addition of 60 percent aqueous citric acid. As this is done, the black vanadium complex forms as a dispersion in the gelatin solution. The warm dispersion is chill-set, noodled, and washed one hour after it has been kept one hour at room temperature. This dispersion is diluted with one part of 5 percent gelatin solution and coated on a thin base at approximately 10 ml per square foot.

Strips of the coated base are bathed over half of their area each in a solution containing 0. 1 equivalent of various activator precursors for about 1 minute. After drying, the coating is heated at C for 4 seconds. The portion of this sample that has been treated is substantially reduced in density compared to the portion which has not been treated. The results are given in Table 1.

Table 1 Change in Density Produced on Heating Coatings Containing lmbibed Activator Precursors The data shows that the density of antihalation layers which contain the alkali precursors may be considerably reduced by heat treatment above. No significant change takes placein the control coating; however,

density changes up to 0.38 take place in coating containing the precursors.

"saturate Polyvinyl alcohol (Lemol 60-99) solutions containing 0.027 equivalent/liter of alkali precursors listed in.

" ""T alile'll" W in which R represents a group selected from the class consisting of hydrogen, -SO H, halogen, carboxyl, acyl containing lcarbon atoms, alkyl containing l-20 carbon atoms, and aryl containing 6-12 carbon atoms and R, represents a member selected from the class consisting of R and aanilinobenzyl and an alkali precursor selected from the group consisting of cyclic carbonates derived from ethylene glycol, guanidinium salts, quaternary ammonium malonates, amino acids, heat cleavable organic hydrazide compounds and oxazolidones. I

2. An element of claim 1 in which said alkali precursor is stable at temperatures up to about C. and becomes labile at temperatures above about 90C.

3. An element of claim 1 in which said alkali precursor is 2-hydroxyethy1 isothiuronium trichloroacetate.

Change in Density Produced on Heating Hand- I Coatings of Alkali Precursors Wet Thickness Density Density Compound (gm/liter) of Coating Unheated Heated AD (in mils) None 2 1.08 0.86 0.22 4 0.96 0.78 -0.l8

Guanidinium trichloro- 2 1.05 0.72 0.33

acetate (6.0) 4 0.96 0.52 -0.44

2-Hydroxyethyl isothiuronium 2 0.92 0.62 -0.30 trichloroacetate (7.75) 4 0.96 0.58 0.38

Piperazinium monomalonate (5.0) 2 1.04 0.60 -0.44 4 0.98 0.41 0.57

Sodium trichloroacetate (5.0) 2 1.06 0.72 0.34 4 0.98 0.58 0.40

-Aminocaproic acid (3.5) 2 0.91 0.60 --0.31 4 0.96 0.54 0.42

Benzyl-B-alanine (5.0) 2 0.90 0.60 -0.30 4 0.92 0.48 0.44

All of the base-release agents reduce the density of the vanadium complex antihalation layers when the coating is heated for 4 seconds at 190C.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit aiid scope of the} invention. 1 claim:

1. An element comprising a support, a light-sensitive coating, an 8-hydroxyquinoline vanadium complex having the following formula:

4. Ari e1emeritof claim 1 in which the alkali precursor is guanidinium trichloroacetate.

5. An element of claim 1 in which the alkali precursor is piperazinium monomalonate.

6. An element of claim 1 in which the alkali precursor is sodium trichloroacetate.

7. An element of claim 1 in which the alkali precursor is 6-aminocaproic acid.

8. An element of claim 1 in which the alkali precursor is benzyl-Balanine. v

9. An element of claim 1 in which said complex is in i a layer contiguous to said lightsensitive coating.

hydroxyethyl isothiuronium trichloroacetate.

* k t 3 a

Claims

2. An element of claim 1 in which said alkali precursor is stable at temperatures up to about 45*C. and becomes labile at temperatures above about 90*C.
3. An element of claim 1 in which said alkali precursor is 2-hydroxyethyl isothiuronium trichloroacetate.
4. An element of claim 1 in which the alkali precursor is guanidinium trichloroacetate.
5. An element of claim 1 in which the alkali precursor is piperazinium monomalonate.
6. An element of claim 1 in which the alkali precursor is sodium trichloroacetate.
7. An element of claim 1 in which the alkali precursor is 6-aminocaproic acid.
8. An element of claim 1 in which the alkali precursor is benzyl- Beta alanine.
9. An element of claim 1 in which said complex is in a layer contiguous to said lightsensitive coating.
10. An element of claim 1 in which said complex is in said lightsensitive coating.
11. An element of claim 1 in which said complex and said alkali precursor are in the same layer.
12. An element of claim 1 in which said complex is in a layer contiguous to a layer containing said alkali precursor.
13. A photothermographic element of claim 1 in which said light-sensitive coating is a photosensitive silver halide layer and an oxidation-reduction image forming combination comprising an oxidizing agent with a reducing agent.
14. An element of claim 11 containing 2-hydroxyethyl isothiuronium trichloroacetate.