US3518085A

US3518085A - Lith-type emulsions containing a polyalkyleneoxy polymer and a 3-pyrazolidone developing agent

Info

Publication number: US3518085A
Application number: US489736A
Authority: US
Inventors: Kirby M Milton; Charles A Goffe
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1965-09-23
Filing date: 1965-09-23
Publication date: 1970-06-30
Anticipated expiration: 1987-06-30
Also published as: GB1164494A; DE1547734C3; DE1547734B2; BE686827A; DE1547734A1

Description

United States Patent 3,518,085 LITH-TYPE EMULSIONS CONTAINING A POLYALKYLENEOXY POLYMER AND A 3-PYRAZOLIDONE DEVELOPING AGENT Kirby M. Milton and Charles A. Golfe, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Sept. 23, 1965, Ser. No. 489,736 Int. Cl. G03c 5/24, 1/28, 1/04 US. Cl. 96--66.3 23 Claims ABSTRACT OF THE DISCLOSURE High contrast photographic emulsions in which the silver halide comprises at least 50% silver chloride are improved by the addition of a polyalkyleneoxy polymer and a 3-pyrazolidone silver halide developing agent. Further improvement is obtained by the incorporation of a vinyl polymer and an onium salt.

This invention relates to high-contrast, silver-halidesensitized photographic materials for graphic arts use and particularly to lith-type silver halide emulsion layers of improved physical and photographic properties.

In the photomechanical arts, photographic films capable of providing high image contrast and good dimensional stability with varying temperature and humidity are required for the preparation of the line and halftone film intermediates which are used in making printing plates. In reproducing continuous tone material, it is customary to make a halftone photographic intermediate, usually a film negative, in which the gradations in tone are represented by differing sizes of dots of uniform density. The shape, density and uniformity of the halftone dots are closely correlated to the quality of the resulting picture.

Most lith films are processed in hydroquinone-type developers which contain relatively low concentrations of sulfite ion. The dot quality and the development contrast obtained in processing lith emulsions in such developers can be improved by processing in the presence of certain water-dispersible polymers containing substantial proportions of ethylene oxide units, such as polyethylene oxides, their terminally substituted derivatives, block copolymers containing ethylene oxide units, etc. These can be added either to the photographic element or the developing solution or both.

It is further advantageous to use as part of the colloid binder for lith type emulsions a colloid-compatible vinyl polymer, the presence of which improves the dimensionable stability of the resulting lith film.

The marked improvement resulting from the use of the ethylene oxide polymer on the contrast and dot quality of the emulsion and that of the vinyl polymers on the dimensional stability of the element may result in certain unwanted effects on other properties such as decreasing the developing rate, impairing the emulsion speed, and narrowing the development latitudes.

There is accordingly a need for a lith film system which will provide the advantages afforded by the above two types of addenda without the possibility of detrimental 3,518,085 Patented June 30, 1970 results and which will produce measurable and simultaneous improvements in (1) physical properties, e.g., dimensional stability and emulsion hardness, (2) photographic properties, e.g., exposure latitude, sensitivity, contrast, line and dot quality, and (3) processing characteristics, e.g., development rate and development latitude.

We have found a method of overcoming the undesirable side effects of adding polymers to the gelatin of lithtype emulsions without impairing their beneficial action.

It is an object of this invention to provide a photographic lith-type silver halide sensitized film of high dimensional stability, which yields high contrast, excellent dot quality, high emulsion speed, which develops uniformly in short developing times, and which shows superior exposure and development latitude.

It is a further object to provide lith-type films containing a compoundwhich reduces the adverse effect of prolonged development induction times which may be required when certain vinyl polymers are used to improve dimensional stability. It is a further object to provide lith-type films containing a compound which regains the effective photographic speed lost when certain ethylene oxide polymers are used to improve contrast and dot quality.

It is a further object to provide lith-type films containing a compound which produces, synergistically in combination with certain ethylene oxide block copolymers, improved speed, contrast and dot quality.

It is also an object to provide improvements in the development of silver halide images.

It is a further object to provide a photographic lith film with improved properties which can be processed in a simple lith-developer containing a sufficiently high concentration of sulfite ion to provide good resistance to aerial oxidation by the developer.

It is a further object to provide lith-type films containing a compound which reduces the adverse eifect on emulsion hardness which may be produced by certain ethylene oxide polymers used to improve contrast and dot quality.

We have accomplished these and other objects which will be apparent from the further disclosures and the claims by adding a 3-pyrazolidone compound to lith-type silver halide sensitized photographic materials containing polymeric addenda for the purpose of improving photographic properties.

Our invention provides an improved photographic lithtype film material comprising a radiation sensitive hydrophilic colloid silver halide emulsion, an alkyleneoxy polymer, and a S-pyrazolidone.

In one embodiment of this invention an aqueous silver chlorobromoiodide lithographic emulsion containing at least 50% silver chloride and a reduced amount of gelatin is prepared in a manner familiar to those skilled in the art. To this emulsion are then added a gelatin-compatible vinyl polymer, a polyalkyleneoxy compound and a pyrazolidone silver halide developing agent. This preparation is then coated on a suitable film support, dried, sensitometrically exposed, processed in a lith-type developing solution, fixed and dried.

The fine grain silver halide emulsions used to advantage have silver halide crystals preferably containing at least 50 mole percent chloride. The emulsions can be prepared as described by MacWilliam US. 2,756,148, issued July 24, 1956. These emulsions may be used without being sensitized, however, it is advantageous to spectrally sensitize them according to methods Well known in the art to make them ortho-sensitized or panchromaticallysensitized.

The silver halide is dispersed in hydrophilic colloid materials used as binders, including gelatin, collodion, gum arabic, cellulose ester derivatives, such as, alkyl esters of carboxylated cellulose, hydroxy ethyl cellulose, carboxy methyl hydroxy ethyl cellulose, synthetic resins, such as the amphoteric copolymers described by Clavier et al. in US. Pat. 2,949,442, issued Aug. 16, 1960, polyvinyl alcohe], and others well known in the art. Examples of these polymeric gelatin substitutes are copolymers of allylamine and methacrylic acid; copolymers of allylamine, acrylic acid and acrylamide; hydrolyzed copolymers of allylamine, methacrylic acid and vinyl acetate; the copolymers of allylamine, acrylic acid and styrene; the copolymers of allylamine, methacrylic acid and acrylonitrile; alkyl acrylate-acrylic acid copolymers, e.g., copolymers of butyl acrylateacrylic acid; etc., and etc.

Useful compatible vinyl polymers include the following:

(1) Copolymers of butylacrylate and acrylic acid such as those disclosed in U.S. Pat. 3,062,674.

(2) Interpolymers of acrylic acid, unsaturated carboxylic acid esters, and sulfobetaines such as those disclosed in U.S. Ser. No. 449,879 filed Apr. 21, 1965, now US. Pat. No. 3,411,912.

(3) Interpolymers of alkyl esters of unsaturated carboxylic acid with sulfoesters of unsaturated carboxylic acids such as those disclosed in US. Ser. No. 454,683 filed May 10, 1965, now Pat. No. 3,411,911.

(4) Homopolymers of acrylic acid esters, homopolymers of ot-hydrocarbon substituted acrylic acid esters. Copolymers of unsubstituted or substituted acrylic acid esters with other vinyl compounds, containing at least 90% by weight of acrylic acid ester structural units such as those disclosed in British Pats. 955,191 and 961,490.

The vinyl polymers are incorporated in the photographic elements of our invention at quantities ranging from approximately 30 to 80 percent of the total emulsion vehicle. In one embodiment in which a gelatin emulsion is employed, the ratio of gleatin to vinyl polymer ranges from 20:80 to 80:20 parts by weight.

Other vinyl polymers useful in our invention may include those disclosed in U.S. Pats. No. 1,933,052, patented Oct. 31, 1933 and No. 2,140,048, patented Dec. 13, 1938 and US. AlienProperty Custodian Ser. No. 397,138, published May 11, 1943.

The alkyleneoxy polymers useful in tihs invention are:

(1) Water-dispersible polyethylene oxides having molecular weights of from approximately 400 to approximately 4,000. Particularly useful polyethylene oxides include the following:

M.W. Polyethylene glycol 400 Polyethylene glycol 600 Polyethylene glycol 425 Polyglycol 1000 Polyglycol 4000 These compounds may be expressed by the general formula:

HOCH CH O (CH O CH CH OH wherein n is an integer greater than 10.

Other useful polyglycols include, for example, polyethylene glycol oleyl ether, polyethylene glycol ether, as well as the polyethylene glycols disclosed in US. Pats. Nos. 2,531,832, 2,423,549, and 2,886,437.

(2) Water-dispersible alkyleneoxy block copolymers containing at least about 30 percent by weight of ethyleneoxy units. Particularly useful water-soluble block polymers include those block polymers in which the polyoxypropylene chain (or moiety) has an average molec- 4 ular weight between 800 and 3,000 and in which the polyoxyethylene units constitute from about 10 to about 70 percent by weight of the polymer.

The water-soluble block polymers of polyoxypropylene and polyoxyethylene used to advantage inc ude those represented by the formula:

wherein Y represents an organic radical having a valence of x, said radical being the residue of an organic compound containing atoms selected from the class consisting of carbon, hydrogen, oxygen, nitrogen and sulfur with x active hydrogen atoms, such as, the residue of polyhydroxy compounds, e.g., ethylene glycol, 1,2-propanediol, 1,5 pentanediol, 1,2,3 propanetriol, sucrose etc., the residue of a polybasic acid, e.g., oxalic acid, malonic acid, succinic acid, maleic acid, citric acid, etc.,

the residue of a polyamine, e.g., ethylenediamine, 1,3-diaminopropylene, etc., the residue of a polyamide, e.g., malonamide, succinamide, etc., the residue of a polythiol, e.g., 1,2-ethylenedithiol, 1,3-propylenedithiol, etc., 11 is an integer greater than 1; x is an integer greater than 1, so that the values of n and x are such that the molecular weight of the said polymer exclusive of Y, E and R is between 800 and 3,000; E represents a polyoxyethylene chain constituting from about 10 to about 70 percent by weight of said block polymer; and R represents the hydrogen atom, an alkyl group having from 1 to 20 carbon atoms, (such as methyl, propyl, decyl, dodecyl, octadecyl, etc.), an alkyl carbonyl group in which the alkyl groups has from 1 to 20 carbon atoms as described above, an aryl carbonyl group, such as, benzoyl, p-methyl benzoyl, etc.

Included among the preferred block polymers are those having the formula:

in which b represents an integer of from 14 to 42; a and c are each integers such that the sum of a+c has a total of from 4 to 48 and the polyoxyethylene groups constitute between 10 and 70 percent by weight of the block polymer.

The block polymers of Formula II and of Formula I where R represents the hydrogen atom are described in Lundsted US. Pat. 2,674,619, issued Apr. 6, 1954 and Lundsted US. Pat. 3,022,335, issued Feb. 20, 1962. The block polymers of Formula I in which R is hydrogen are readily converted to compounds where R represents an organic residue by reaction with the appropriate reagent in a suitable inert organic solvent that is preferably anhydrous. For example, alkyl halides, such as alkyl chlorides, alkyl bromides, etc., are used to advantage to replace the terminal hydrogen atom of the block polymer with an alkyl group. Alkyl-p-toluenesulfonates are also used to advantage to place an alkyl group at the end of the block polymers. The appropriate acid chloride or acid anhydride, such as, acetyl chloride, propionyl chloride, stearoyl chloride, benzoyl chloride, acetic anhydride, etc., are used to advantage to prepare block polymers of Formula I in which R is an alkyl carbonyl or an aryl carbonyl group.

(3) Water dispersi ble alkyleneoxy block copolymers containing at least about 30 percent by weight of ethyleneoxy units and containing in their main chain up to approximately 15 percent by Weight silicone atoms. Particularly useful water-soluble organosilicone polyalkylene oxide polymers include those disclosed in US. Pat. No. 2,917,480, issued Dec. 15, 1959. Polymers used to advantage are of the type which are prepared by reacting a dialkyl siloxane with a compound of the following structure:

wherein Y is the residue of an organic compound containing therein, x active hydrogen atoms, and wherein n is an integer, x is an integer greater than 1, the values of n and x are such that the molecular weight of the compound exclusive of E and R is between 800 and 3,000, and E is a polyoxyethylene chain constituting 70% by weight of the compound, R is hydrogen or the residue of an organic compound containing an active hydrogen atom; e.g., alcohols, amines. acids, amides, phenols, etc.

The above alkyleneoxy block copolymers (2 and 3) have molecular weights ranging from approximately 600 to about 10,000.

The alkyleneoxy polymers may be added to the photographic element at any stage in the preparation. They may be added as such or from an aqueous solution or from an organic solvent, e.g., ethanol, but are advantageously added from solutions in water. They are added to the aqueous hydrophilic colloid (either with or without the silver halide) before it is coated. The alkyleneoxy polymerscan be used to advantage over a wide. range of concentrations. The operable range of concentrations is from 0.01 to 3.00 gram of polymer per mole of silver, while the particularly useful range is from 0.010 to 1.0 gram per mole of silver. The optimum concentration of a given alkylene oxide-containing polymer used in my elements depends upon the results desired, the particular silver halide emulsion, the developer solution, etc., and is readily determined by methods known in the art. The determination of the optimum concentration is preferably made by employing the alkyleneoxy polymer in the silver halide emulsion layer or in an adjacent hydrophilic colloid layer according to the element that is desired.

It is advantageous to add certain onium Salts, such as, quaternary ammonium salts, sulfonium salts and phos phonium salts to our light-sensitive emulsions in order to increase the photographic speed Without adversely affecting the improved dot quality, contrast and evenness of development. Examples of quaternary ammonium salts include nonyl pyridinium perchlorate, hexoxymethyl pyridinium perchlorate, ethylene bis-dioxymethyl pyridiniurn perchlorate and others described by Carroll U.S. 2,271,623, issued Feb. 3, 1942, hexadecamethylene-l,l6- bis(pyridinium perchlorate), 9,l6-diaza-7,18-dioxa-8,l7- dioxotetracosane 1,24 bis(pyridinium perchlorate), and others of Beavers et al. U.S. 2,944,898, issued July 12, 1960. Other examples include the onium salts of polyoxyalkylenes of Carroll et al., U.S. 2,944,902, issued July 12, 1960, the polyonium salts of Carroll et al. U.S. 2,288,- 226, issued June 30, 1942, such as bis(lauryl methyl sulfonium p-toluene sulfonate) 1,2-ethane, N,N-trimethylene dioxymethyl pyridinium perchlorate, etc., the sulfonium salts of Carroll et al. U.S. 2,275,727, issued Mar. 10, 1942, such as, n-decyl dimethyl sulfonium p-toluene sulfonate, n-nonyl dimethyl sulfonium p-toluene sulfonate, etc., and the phosphonium salts of Carroll et al. U.S. 2,271,622, issued Feb. 3, 1942, such as, tetramethylene bis-triethyl phosphonium bromide, lauryltriethylphosphonium bromide, etc.

The onium salts are added to the photographic materials at concentrations ranging from approximately 0.01 to approximately 2.0 gram per mole of silver in the light sensitive emulsions. The preferred range is from approximately 0.035 gram to approximately 0.65 gram per mole of silver.

The use of the onium compound alone does not result in any particular improvement in speed in lith emulsions containing vinyl polymers and ethyleneoxy polymers.

The addition of 3-pyrazolidone to the emulsion containing the onium salt, however, gives a very surprising increase in emulsion speed and this is enhanced further by some apparent synergism between the 3-pyrazolidone and an onium compound. The pyrazolidones used to advantage 6 include those disclosed in U.S. Pat. No. 2,751,297 and represented by the following general formula:

XN CHRI l-phenyl-3-pyrazolidone 1-p-tolyl-3 -pyrazolidone 5-phenyl-3-pyrazolidone 5-methyl-3-pyrazolidone 1-p-chlorophenyl-3pyrazolidone l-phenyl-5-phenyl-3-pyrazolidone l-m-tolyl-3-pyrazolidone l-phenyl-5-methyl-3-pyrazolidone 1-p-tolyl-5-phenyl-3pyrazolidone 1-m-tolyl-3-pyrazolidone 1-p-methoxyphenyl-3pyrazolidone 1-p-acetamidophenyl-3-pyrazolidone I 1-phenyl-2-acetyl-4 4-dimethyl-3 -pyrazolidone 1-phenyl-4 4-dimethyl-3-pyrazolidone 1-m-aminophenyl-4-methyl-4-n-pro pyl-3-pyrazolidone 1-o-chlorophenyl-4-methyl-4-ethyl-3pyrazolidone 1-m-acetamidophenyl-4:4-diethyl-3pyrazolidone l- (p-fi-hydroxyethylphenyl) -4 4-dimethyl-3-pyrazolidone l-phydroXyphenyl-4 4-dimethyl-3-pyrazolidone 1-p-meth0xyphenyl-4: 4-diethyl-3 -pyrazolidone 1-p-tolyl-4 4-dimethyl-3-pyrazolidone 1 (7 hydroxy 2 naphthyl) 4-methyl-4-n-propyl-3- I pyrazolidone 1-p-diphenyl-4 4-dimethyl-3-pyrazolidone 1-(p-B-hydroxyethylphenyl)-3-pyrazolidone l-o-tolyl-3-pyrazolidone l-o-tolyl-4 4-dimethyl-3-pyrazolidone l-benzothiazolyl-3-pyrazolidone 4-methyl-1-phenyl-3-pyrazolidone Useful concentrations of pyrazolidones in the photographic elements range from 0.005 to 2.0 gm./mole of silver in the emulsion. The preferred range is from 0.01 to 1.0 gm./mole of silver. Optimum concentrations of the alkyleneoxy polymers and the pyrazolidones can be determined readily by actual tests in the emulsion and will vary with the formulation of thephotographic emulsion and the developer used.

In general, both the alkyleneoxy polymer and the pyrazolidone are incorporated in the light-sensitive silver halide emulsion. While this is a particulary useful form of the invention, either or both the alkyleneoxy polymer and pyrazolidone may alternatively be present in an adjoining insensitive layer, or one or both can be imbibed from a processing bath, it being required only that both are present during development.

Our light-sensitive emulsions can be coated to advantage on any of the conventional photographic supports, including glass, cellulose acetate, polystyrene, polyalkyleneterephthalate, etc.

A typical lith-type developing solution which may be used contains as the only developing agent, hydroquinone or a hydroquinone derivative and having a very low sulfite ion content, the sulfite ion content being maintained by the presence in the solution of formaldehyde. Lith-type developing solutions are used for developing lithographic film materials which contain photographic emulsions having an emulsionsof uniform and fine-grain silver halide crystals. Such emulsions are developed in lith-type developing solutions to yield a contrast of 10 and above.

A typical lith-type developing solution is Kodak De- The film samples were then fixed, washed and dried, and the speed, contrast, fog and dot quality evaluated. A dot quality scale from 1 to 10 represents increasing quality of half-tone dot with increasing number, 6 being a first acceptable quality of half-tone dot. The results are illustrated in Table I.

veloper D-85 (see Kodak Formulas for the Graphic Arts, Kodak Pamphlet No. Q41, p. 4) as follows:

KODAK DEVELOPER D-85 I Water about 90 F. (30 C.) metric cc 500 Sodium sulfite desiccated grams 30.0 Paraformaldehyde do 7.5 Sodium bisulfite do 2.2 Boric acid crystals do 7.5 Hydroquinone do 22.5 Potasium bromide .Q. do 1.6

Water to make 1.0 liter. A

The following examples are intended to illustrate our invention but not to limit it in any way:

EXAMPLE I A high-contrast ortho-senitized fine-grain gelatino chlorobromoiodide emulsion containing 90 mole percent 35 The results are illustrated in Table II.

silver chloride, 9 mole percent silver bromide, and ap- It is shown that the addition of PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540, raised contrast, dot quality, but caused speed loss. Further addition of Elon did not regain speed loss.

EXAMPLE II Example I was repeated, except that the methyl-paminophenol was replaced by 4-methyl-l-phenyl-B-pyraz olidone as shown below:

(a) no further addition I '(b) 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540 (c) 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540, plus .025 gm. 4-methyl- 1-phenyl-3-pyrazolid0ne (d) 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540, plus .050 gm. 4-methyl- 1-phenyl-3-pyrazolidone TABLE II 2V minutes developing time 3% minutes developing time Relative Effective D ot Relative Efleetive Dot speed contrast quallty Fog speed contrast quality Fog proximately 1 mole percent silver iodide was prepared and split into separate portions. The following compounds were added to the individual portions in the indicated amounts per mole of silver halide:

(a) no further addenda (b) 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540 (c')" 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540 plus 0.025 gm. methylp-aminophenol (d) 0.5 gm. PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540 plus 0.050 gm. methylp-aminophenol M p Thevarious parts were coated on acellulose triacetate film support at a coverage of 455 mg. of silver halide and 1.450 mg. of-vehicle per square foot, dried, exposed to continuous and half-tone screen step wedges, developed for 2% minutes and 3%.minutes, respectively, at a temperature of 68 F. in a developing solution of the following composition: H

Hydroquinone 15.0 Sodium formaldehyde bisulfite 50.0 Sodium bicarbonate 22.5 Sodium carbonate 35'.0 Sodiumsulfite 2.5 Potassium bromide 0.75.

Water to make 1 liter.

It is shown that the addition of PEO, oleyl ether of polyethylene glycol having a molecular weight of 1540, raised contrast and dot quality but caused speed loss. Further addition of a 3-pyrazolidone regained speed, maintained contrast and dot quality.

EXAMPLE III An emulsion was prepared as described in Example I. The following compounds were added to the individual portions in the indicated amounts per mole of silver halide.

TABLE III [DEVELOPING TIME: 1% MINUTES] Relative speed Efieetive contrast Sample a 100 55 b 741 6. 3 e. 289 2. 4

EXAMPLE IV TABLE IV [DEVELOPING TIME: 2% MINUTES Relative speed Effective contrast Control. 194 5. 4 Sample containing 4-methyl'1- phenyl-Ekpyrazolidone 253 11. 2

Result: 4-methyl-l-phenyl 3 pyrazolidone has increased speed and contrast.

EXAMPLE V An emulsion was prepared as in Example IV and split into two portions, (a) and (b). To each portion were added, per mole of silver halide, .030 gm. of organosilicone, coply(polyethyleneoxypolypropyleneoxy dimethylsiloxane), mol weight 2000, PPG-PEG 6040, 9.5% by weight silicone. To portion (b) was added, in addition, .015 gm. of 4-methyl-1-pheny1-3-pyrazolidone per mole of silver halide. Each sample was processed and evaluated as in Example I. The results are shown in Table V.

TABLE V [DEVELOPING TIME: 1% MINUTES] Relative speed Efiective contrast Result: The 3-pyrazolidone has increased speed and contrast.

EXAMPLE VI An emulsion was prepared as in Example IV and split into two portions, (a) and (b). To each portion were added, per mole of silver halide, 0.100 gm. of an organosilicone, a water-soluble polysiloxane made up of dimethyl silicone sections and polyether sections and containing 6.5% by weight of silicone, and .5 gm. of w-hydroxydecylpyridinium-perchlorate. To portion (b) were added, in addition, .015 gm. of 4-methyl-l-phenyl-3-pyrazolidone. Each sample was processed and evaluated as in Example I. The results are shown in Table VI.

TABLE VI.-DEVELOPING TIME: 2 MINUTES Relative speed Efieetive contrast Result: Addition of an onium salt, a known developer accelerator, has given acceptable speed, but has lowered contrast. Addition of 4-methyl-1-phenyl-3-pyrazolidone has improved speed further and given excellent contrast.

10 EXAMPLE v11 .This is a repeat of Example VI, except that Sample (a) contained only 0.085 gm. of the organosilicone of Example VI.

The results are shown in Table VII.

TABLE VIL-DEVELOPING TIME: 2 MINUTES I Relative speed Effective contrast Results: Same as in Example VI.

EXAMPLE VllII An emulsion was prepared as in Example IV and split into three portions, (a), (b), and (c). To portion (a) were added per mole of silver halide, .025 gm. of a block copolymer of polyethyleneoxide and polypro'pyleneoxide units having a total molecular weight of 2000 and wherein the molecular weight of the polypropyleneoxide constituent is 1200 and wherein the ratio by weight of the polyethyleneoxide to polypropyleneoxide is 60 to 40; to portion (b), .025 gm. of a polymer similar to (a) above, having a total molecular weight of 2920 and wherein the molecular weight of the polypropyleneoxide constituent is 1750 and wherein the ratio by weight of the polyethyleneoxide to polypropyleneoxide is 40 to 60; to portion (c), .055 gm. of a polypropyleneoxide-polyethyleneoxide glutarate having a total molecular weight of 2000 and wherein the ratio by weight of polyethyleneoxide to polypropyleneoxide is 60 to 40' and wherein the polypropylene constituent has a molecular weight of 1200. To each portion were added, in addition, .015 gm. of 4-methyl-1- phenyl-3-pyrazolidone and .3 gm. of w-hydroxydecyl pyridinium-perchlorate. Each sample was processed and evaluated as in Example I. The results are shown in Table VIII.

Result: All coatings showed excellent speed and good contrast.

EXAMPLE IX An emulsion was prepared as in Example I wherein the vehicle comprised, per mole of silver halide, 70 gm. of gelatin and 70 gm. of copoly(butyl acrylateacrylic acid- 4,4,9 trimethyl 8-oxo-7-oxa-4--azonia-9-decene-l-sulfonate). The emulsion was split into two portions, (a) and (b). To each portion were added, per mole of silver halide, .075 gm. of the block polymer A of Example VIII and .500 gm. of w-hydroxydecyl pyridinium-perchlorate. To portion (b) were added, in addition, .015 gm. of 4- methyl-1-pheny1-3-pyrazolidone. Each sample was processed and evaluated as in Example I. The results are shown in Table IX.

The advantageous efifeot of the 3-pyrazolidone with respect to speed and contrast is retained when the vinyl polymer concentration in the emulsion vehicle is increased to constitute 50 percent of the total vehicle.

EXAMPLE X To an emulsion as described in Example I were added, per mole of silver halide, 0.1 gm. of organosilicone block polymer of Example VI. The emulsion was then divided into two portions, A and B. To portion B were added,

1 1 per mole of silver halide, 0.015 gm. of 4-methyl-1-ph nyl- 3-pyrazolidone. After coating, the above portions of emulsion as described in Example I, samples of each film were processed as described in Example I at the developing times as shown below: the results are listed in Table X.

It is shown that the addition of small amounts of 4- methyl-l-phenyl-3-pyrazolidone to silver halide emulsions containing polyalkylene oxide-dialkyl siloxane polymers results in an increase in speed, contrast and halftone dot quality over a wide range of developing time.

EXAMPLE XI One film sample of each coating made with emulsion portions A and B of Example X was incubated for 1 week at 120 F. and 50% relative humidity. Each of the incubated samples was, together with a nonincubated corresponding sample, immersed at a temperature of 68 F. for 4 minutes into a developing solution of the following composition:

Water ml 500 Methyl-p-aminophenol gm 1.0 Sodium sulfite, dessicated gm 75.0 I-Iydroquinone r gm 9.0 Sodium carbonate, monohydrate gm 30.0

Potassium brodide gm 5.0

Water to make 1.0 liter.

The observed fog of each sample is recorded in Table XI.

TABLE XI Fog Fresh test Ineubated sample Coating:

It is shown that the presence of 4amethyl-1-phenyl-3-pyrazolidone has effectively protected the film material against fog growth upon incubation.

EXAMPLE XII TABLE XII Developing time, Relative Effective min. speed contrast Coating:

a 2 100 7. 5 b 2 115 10. 5 e 2 186 9. 0

12 EXAMPLE XIII This example illustrates the advantage derived from the presence of the pyrazolidone in the emulsion over its presence in the developer solution. It also illustrates, again, the superiorty of a pyrazolidone over other common developing agents as an addenda in the lith-type materials of our invention.

Several film strips were prepared according to the procedures described in the preceeding examples. They comprised, in addition to silver halide and other common addenda, the following compounds per mole of silver halide:

Block polymer A of Example VIII, grams Developer Strip A 0. 025 4-methyl-l-phenyl-3-pyrazolidone,

0.015 gm. B 0. 025 Hydroquinone, 0.5 gm. C 0. 025 N-methyl-p-aminophenol, 0.5 gm. D 0.025 None.

Strips A, B, and C were developed in the developer solution of Example I. Strip D- was developed in the developer soution of Example I to which were added 5 gm. of 4-methyl-1-phenyl-3-pyrazoidone per liter of solution. The development time was in each case 1% minutes.

Relative Effective Dot spee contrast quality Fog Effective Contrast of a developed photographic material differs from the conception of contrast which is in the photographic art generally synonymous with only the slope of the straightline portion of the characteristic curve, in that the slope of the characteristic curve in the toe region is also taken into account. For example, two diiferent photographic materials may exhibit identical contrasts, but the one whose characteristic curve shows also a more acute shape of the curve in the toe region has a higher effective contrast.

Other tests similar to those described above have shown (a) that coatings of lith-type emulsions containing a vinyl polymer for the purpose of improving dimensional stability require a considerably longer development time to yield satisfactory dot quality than coatings not containing such vinyl polymers and that at such prolonged development times the vinyl polymer containing coatirigs produced unacceptably high fog, (b) materials as described under (a) which, in addition, contained a 3-pyrazolidone did not exhibit the cited undesirable side effects introduced by the vinyl polymer.

The quality of the silver images produced in lithtype emulsion layers is conveniently measured in terms of efiective contrast and dot quality. Dot quality is a measure of the quality of the reproduction of a halftone image lith-type photographic elements exposed to a half-tone image, and developed, produce areas commonly referred to as shadow dots and areas known as highlight areas. Intermediate between these two extremes are areas of varying size. The dot quality used herein is a measure of the areas referred to as 50% dots Ge, /2 clear, and V2 developed denisty) and is expressed in a progressive scale where 9 is excellent and 1 is extremely poor. A 50% dot quality below 6 is generally not acceptable.

. 13 g The beneficial combination of addenda which constitutes our invention are used to particular advantage in lith emissions containing more than 50 mloe percent of silver chloride. The image reproductions produced in our lithographic emulsion layers-are of excellent quality. Although the conventional alkaline, pure hydroquinone, low free-sulfite developer may be used to develop these exposed elementsyit is also advantageous to use a pure hydroquinone developer having 'from to about 30 grams of an alkali-sulfiteper liter of developing solution or even an Elon-hydroquinone developer having from 10 to about 30 grams of an alkali-sulfite per liter of developing solution. When the elements of this invention are developed in .one of theitwo latter developing solutions, not only is the image contrast high and the dot quality excellent, but this excellent quality is produced over a wide range of exposure and development times,

Typical olymeric vinyl compounds useful in our invention are disclosed in.U. S. P at; 3,142,568, issued July 28, 1964, incorporated herein 'byL-ref erence'.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that var can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim: 1

1. A light-sensitive photographic element comprising a support having thereon at least one light-sensitive silver halide emulsion in which the chloride comprises at least 50 mole percent of the halide, containing a hydrophilic colloid binder, a polyalkyleneoxy polymer in amount of about 0.01 gram to about 3.0 grams per mole of silver halide, and a 3-pyrazolidone silver halide developing agent in an amount of about 0.005 gram to about 2.0 grams per mole of silver halide.

2. A photographic element of claim 1 in which the colloid binder is gelatin.

3. A light sensitive photographic containing an onium salt.

4. A light sensitive photographic element of claim 2 containing an aqueous dispersion of a polymerized vinyl compound.

5. A light sensitive photographic element of claim 2 comprising an aqueous dispersion of a polymerized vinyl compound and an onium salt.

6. A light sensitive photographic element of claim 2 in which said support is a dimensionally stable polymeric support and said element comprises an aqueous dispersion of a polymerized vinyl compound and an onium salt.

7. A photographic element of claim 4 in which the ratio of gelatin to vinyl polymer ranges from 20 to 80 to 80 to 20 parts by weight.

8. A photographic element of claim 4 in which the vinyl polymer comprises an acrylic acid-ester polymeric compound selected from the group consisting of a homopol mer of an acrylic acid-ester and a copolymer of ac. lic acid-ester and acrylic acid, said copolymer containing at least 80% by weight of units of said acrylic acid esters.

9. A photographic element of claim 4 in which the vinyl polymer comprises an interpoly-mer selected from the group consisting of acrylic acid, unsaturated carboxylic acid esters and sulfobetaines, said interpolymer containing (1) up to about by weight, of acrylic acid, (2) at least about 75%, by weight of a monomer having the formula:

element of claim 2 wherein R is hydrogen or methyl and R is an alkyl radiions and modifications 14 cal, containing 1-12 carbon atoms, with (3) up to about 10%, by weight, of a monomer having the formula:

wherein R- is hydrogen or alkyl, R and R are each divalent saturated aliphatic hydrocarbon radicals, containing up to 12 carbon atoms, and R and R are each hydrogen or alkyl.

10. A photographic element of claim 1 in which the polyalkyleneoxy polymer is the oleyl ether of polyethylene glycol.

11. A photographic element of claim 1 in which the polyalkyleneoxy polymer is a block polymer of polyoxypropylene" and polyoxyethylene represented by the formula: p

wherein Y represents an organic radical having a valence of x; n is an integer; x is an integer'greater than 1, so that the values of n and x are such that the molecular weight of the said polymer exclusive of Y, E and R is between 800 and 3,000; B represents a polyoxyethylene chain constituting from about 10 to about 70 percent by weight of said polymer; and R is a member selected from the class consisting, of the hydrogen atom, an alkyl group, an alkyl carbonyl group, and an aryl carbonyl group.

12. A photographic element of claim 1 in which the polyalkyle'neoxy polymer is a block copolymer of polyoxypropylene and polyoxyethylene represented by the formula:

wherein b represents an integer of from 14 to 52; and a and c each represent integers such that the sum of a+c represents an integer of from 4 to 48 and the polyoxyethylene groups constitute between 10 and 70 percent by weight of said polymer. 1

13. A photographic element of claim 11 in which the copolymer of polyoxypropylene and polyoxyethylene contains in the main chain silicone atoms at concentration ranges to approximately 15% by weight, of the polymer compound.

14. A photographic element of claim 12 in which the copolymer of polyoxypropylene and polyoxyethylene contains in the main chain silicone atoms at concentrations ranging up to approximately 15%, by weight, of the polymer compound.

15. A photographic element of claim 3 in which the onium salt is selected from the class consisting of a quaternary ammonium salt, a sulfonium salt and a phosphonium salt.

16. A photographic element of claim 3 in which the concentration of the onium salt ranges from approximately 0.01 to approximately 2.0 grams per mole of silver halide inthe emulsion.

17. A photographic element of claim 1 in which the 3-pyrazolidone is selected from the class represented by the following generic formula:

wherein X represents hydrogen or acetyl, R represents a heterocyclic group or an aryl group of the benzene or naphthalene series and R represents hydrogen, an aryl group of the benzene or naphthalene series, or an alkyl group, and R and R each represents hydrogen or an alkyl group.

IS. A photographic element of claim 4 in which the 15 ratio of gelatin to vinyl polymer ranges from 20 to 80 to 80 to 20 parts by weight.

19. A photographic element of claim in which the polymerized vinyl compound comprises an acrylic acidester polymeric compound selected from the group consisting'of a homopolymer of an acrylic acid-ester, and a copolymer of acrylic acid-ester and acrylic acid, said copolymer containing at least 80% :by weight of units of said acrylic acid-esters.

20. A photographic element of claim 5 in which the polymerized vinyl compound comprises an interpolymer selected from the group consisting of acrylic acid, unsaturated carboxylic acid-ester and sulfobetaines, said interpolymer containing (1) up to about 15%, by weight, of acrylic acid, (2) at least about 75%, by weight, of a monomer having the formula:

wherein R is hydrogen or methyl and R is an alkyl radical, containing 1-12 carbon atoms, with (3) up to about by weight, of a monomer having the formula:

wherein R is hydrogen or alkyl, R; and R are each divalent saturated aliphatic hydrocarbon radicals, containing up to 12 carbon atoms and R and R are each hydrogen or alkyl.

21. A photographic element of claim 15 in which the concentration of said polyethyleneoxy polymer present in said emulsion ranges from 0.001 to 3.0 grams per mole of silver halide.

22. A photographic element of claim 15 in which the polyalkyleneoxy polymer is the oleyl ether of polyethylene glycol.

23. A process of developing an exposed photographic silver halide emulsion in which the halide comprises at least mole percent chloride, comprising imbibing into the said emulsion about 0.01 gram to 3.0 grams per mole of silver halide of a polyalkyleneoxy polymer and about 0.005 gram to about 2.0 grams per mole of silver halide of a 3-pyraz0lidone silver halide developing agent, and reducing the exposed silver halide to silver.

References Cited UNITED STATES PATENTS 3,017,271 11/1962 Piper 9666.3 X 3,142,568 7/1964 Nottorf 96-87 3,158,483 11/1964 Lowe et al 96--66.3 3,312,550 4/1967 Stewart et al 96-76 X 3,294,540 12/1966 'Golfe 96107 NORMAN G. TORCHIN, Primary Examiner R. E. FICHTER, Assistant Examiner US. Cl. X.R.