US2444608A

US2444608A - Stabilizers for photographic silverhalide emulsions

Info

Publication number: US2444608A
Application number: US664254A
Authority: US
Inventors: Heimbach Newton; Jr Walter Kelly
Original assignee: General Aniline and Film Corp
Current assignee: GAF Chemicals Corp
Priority date: 1946-04-23
Filing date: 1946-04-23
Publication date: 1948-07-06
Anticipated expiration: 1965-07-06

Description

Patented July 6', 1.948i

UNITED STATES STABILIZERS FOR PHOTOGRAPSHIC SILVER- HALIDE EMULSION Newton Heimbach and Walter Kelly, Jr., Binghamton, N. Y., assignors to General Aniline & Film Corporation, New York, N.. Y., a corporation of Delaware Application April 23, 1946, Serial No. 664,254

This invention relates to 1,3bis[3amino-1,2,4- triazole] oxypropenes, to a method for their preparation, and to photographic silver-halide emulsions containing the same.

It is known in the art that light-sensitive emulsions, such as gelatin silver-halide emulsions, have a decided tendency to fog. The fog may be of two types, namely, yellow fog and chemical (gray) The yellow fog, sometimes referred to as color fog or dichroic fog, is essentially a colloidal deposit of silver, the color intensity and general appearance of which are determined by the minute particle size and degree of subdivision. The fog is chiefly yellow in color and is most apparent in the lighter portions of a negative. The color may vary, however, and the colloidal silver particles may, for example, appear green by reflected light and yellow or red by transmitted light. The so-called chemical fog, or gray fog, on the other hand, is the more common and is formed in a number of ways. It may be caused by premature exposure, by excessive ripening' of` the emulsions, or by the storage of the film, particularly at high temperatures or for unusually long periods of time.

It is an object of the present invention to provide 1,3-bis [3-amino-1,2,4triazolel -oxypropenes useful as stabilizers for silver-halide emulsions.

Another object oi this invention is to provide a process of preparing such 1,3-bis[3-amino-l,2,4- triazolel -oxypropenes A further object is to provide 1,3-bis[3-

amino

1,2,4-triazolel-oxypropenes as stabilizers or fog inhibiting agents which tend to prevent the formation of chemical fog in light-sensitive sil- Ver-halide emulsions,

A still further object is to provide `1,3-bisl3- amino-1,2,4-triazolel-oxypropenes as stabilizers or anti-fogging agents for light-sensitive silverhalide emulsions, which do not lower the sensitivity of the emulsion, an-d which increase its stability.

Still further objects and advantages will appear from the following specification.

We have found that the above objects are accomplished by condensing a -keto ester or anilide thereof, with a 3-amino-1,2,4triazole. The resulting condensation product is characterized by a structure corresponding to the following general formula:

11 Claims. (Cl. 95-7) 2 wherein R isv hydrogen or an alkyl group, e. g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, teit-butyl, amyl, and the like, R1 is an alkyl of the same Value as R, aryl, e. g., phenyl,r

- o, m-, and p-tolyl, naphthyl, diphenyl, etc.,

aralkyl, e. g., benzyl, methylbenzyl, ethylbenzyl, and the like, R2 is either hydrogen allyl, or an alkyl of the same value as R.

The method for the preparation of 1,3-bis[3 amino-1,2,4-triazolel-oxypropenes consists of condensing l mol of a -keto ester or anilide thereof, of the following general formula:

wherein Rs is of the same value as R1, R4 is of the same value as R2, and R5 is an anilino or alkoxy radical, e. g., methoxy, ethoxy, propoxy, butoxy, amoxy, heXoXy, heptoxy, octoxy, and the like, with 2 mols of 3-amino-1,2,ltriazole of the following general formula: v

/N\ Re-(IJ/ NH N= NH2 wherein Re is either hydrogen or an alkyl group, e. g., methyl, ethyl, propyl, butyl, and the like.

Suitable -keto esters and anilides thereof are, for example, ethyl acetoacetate, ethyl benzoylacetate, ethyl a-ethyl acetoacetate, ethyl a-allyl acetoacetate, ethyl toluylacetate, ethyl propionylacetate, ethyl butyrylacetate, ethyl valerylacetate, ethyl acetoacetanilide, ethyl benzoylacetanilide, ethyl a-ethyl acetoacetanilide, ethyl a-alyl acetoacetanilide, ethyl toluylacetoacetanilide, ethyl propionylacetoacetanilide, ethyl butyrylacetoacetanilide, ethyl valerylacetoacetanilide, and the like.

As suitable 3-an1ino-1,2,4triazoles may be mentioned, 3-amino-1,2,4triazcle, 3amino5 methyl -1,2,4- triazole, 3 -amino-5- ethyl-1,2,4- triaz'ole, B-amino -5- propyl -l,2,4 triazole, 3- amino-5-butyl-1,2,4-triazole, B-amino -5- amyl- 1,2, l-triazole, and the like.

The rcondensation [between the -keto ester or anilide thereof, and the 3-arnino-l,2,4triazole is carried out by heating =the reac-tion components at a temperature ranging from -160 C., in the presence of a suitable solvent such as nitrobenzene, for a period oi time ranging from 10 minutes to 2 hours. The iinal product either precipitates or is removed by diluting with an aromatic hydrocarbon, such as,v for example, toluene, chlorobenzene, cyclohexane, cyclohep.

3 tane, cyclooctane, benzene, o, m, and p-Xylene, ethylbenzene, 1,2,4-trimethylbenzene, propylbenzene, l-ethylmethylbenzene, or an 05W- genated solvent, e. g., ether, acetone, ethylmethyl ketone, diet-hyl ketone, dimethyl ketone, propyl ketone, allylacetonecmesityl oxide, dioxane, and= the like, and -iecrystallized from water; Instead of heating the reaction components, the reactants may be allowed to stand in a cold, aqueous, alk

aline solution such as, for example, a 5-207% aque-` ous solution of sodium or potassium hydroxide-l for several days at room temperatura After standing for several days atrroomntemp'eratm'eif the reaction mixture is dilutdi-With'aboutan equal Volume of Water and warmed slightly torcedissolve the precipitated lproduct. To this solution a sufficient quantity of cold-glacial yacetic-.2`

acid is added in order to neutralize the alkali,

and after chilling in an ice-bath, the productie' filtered off and Washedseveral times with cold water andnecrystallizedifromboilingzwater.

'Ile'lr 3-aniir1'o-1,2,4tria2oles. :Fand: the -keto estersand anilidesthereoflarewelliknown to the artfand thezmeth'ods for their.` preparation meed notllceF4 described herein; r

Speci'ccompounds."Which have been .prepared inlaccordaiicelwiththelabve procedures,V with their formulas, are asrfollowsfz CH3 03H5 o amenacen-o C-CHzoH'or CH3 CH3 O Example 1I '1'0"15` cc. of nitrobenzene, 0`.1' incl (8.4' grams) of"3arnino1,2,41-triazole'and U.05`1'n'ol(8.5 grams) of' ethyl a-allyl acetoacetatelwereadded andl the mixtureheatedto' 15U-,160''LC., foi 1 hour.y The reaction mixture -was cooled toroom temperature andl theproduct precipitated by' the addition of ether. `Tlieprecipitated product was washed s'evieral'timeswitlfi'V ether and recry'stallied from Wa-- One-tenth mol (854;y grams) of 3arnino1l,2,4 trlazole is dissolved in 156e.- of- Water andthemix# ture cooled to room-temperature.- To thislsolu-v tion 0.1 mol.-(13grams) offethyl,acetoacetateis added. After standing for lvminutesya coldsolution of 4 grarnsfof NaCbH-in 10 ccs-of- Water` is addedslowlywith external cooling-to *keep-.the mixture approximately at l roomf temperature. After standingA 2 days.- at roomftemperature, the

mixture isdilutedto 40 ccVandWarmed/slightly;

to redissolve the precipitated product. Six grams: of coldiglacial `acetic'acid is their added,- andf after chilling in an icefbathftheproductislteredoff: and Washedvwith a few cc.-offcoldwater andrecrystallized fromtboiling AWater.-

CH3-C To 15 cc. of nitrobenzene, 1 mol (9.8 grams) of 3-amino-5methyll,2,4triazole and 0.05 mol (6.5 grams) of ethyl acetoacetate were added and the mixture heated to 15G-160 C., for 1 hour. The reaction mixture was cooled to room temperature and the product isolated |by diluting with ether and recrystallizing from water.

Example III was repeated with the exception that 9.6 grams of ethyl benzoylacetate was substituted for 6.5 grams of ethyl acetoacetate.

In the preparation of emulsions containing the stabilizers as above prepared, a solution of the stabilizer in a suitable solvent, such as alcohol or an alcohol-water mixture, adjusted to a neutral or slightly alkaline pH, i. e., pH '7.5 to 10, is made up and the solution mixed with the emulsion at any point during its preparation, but preferably during ripening or just prior to coating in concentrations varying from 25 mg. to 500 mg. per liter of emulsion. The `actual concentration employed will depend upon the type of emulsion used and may vary somewhat with the particular compound employed.

The method of testing the stabilizers employed in the following examples consists of coating two film strips, such as cellulose acetate, with the same emulsion, one with and one without any stabilizer, storing the emulsions in an incubator for six days at 50 C., then exposing, developing, fixing, and washing the same under standard conditions. The fog density or -blackening produced in the unexposed areas in the two emulsions is then measured in a transmission densitometer of standard type.

The following examples will serve to illustrate certain ways in which the 1,3-bis[3-amino-l,2,4 triazolel-oxypropenes of our invention are applied as stabilizers for silver-halide emulsions, but are not to be construed as limiting the invention.

Example V A photographic film coated with an ordinary gelatin-bromoiodide `emulsion of normal speed and contrast on development under standard conditions, after incubation for six days at 50 C., gave a fog of 0.28 density. Another film coated with the same emulsion containing an addition of 100 mg. of the compound of Example I per 1000 cc. of emulsion, equivalent'to about 50 grams of silver-halide, and developed under the same conditions, after the same incubation, gave a fog of only 0.06 density.

Eample VI Example V was repeated with the veXcep-tion that an equivalent quantity of the compound of Example II was substituted for the compound of Example I. The results obtained were almost identical with those obtained in Example V.

Ea'ample VII Example V was again repeated with the exception that 75 mg. of the compound of Example the emulsion containing the compound of Ex ample III gave a fog of only 0.1.

Further experiments have shown that emulsions containing stabilizers in accordance with our invention have not only improved keeping qualities (i. e., a reduction in thefog produced by incubation or by long storage), but have-greatly `diminished and, in some cases -completely eliminated changes of vspeed to which some emulsions are susceptible.

The stabilizers, which we have prepared and employed, may be used in various kinds of emulsions. In addition to being useful in orthochromatic and panchromatic emulsions, they may also be used in non-sensitized emulsions and -X-ray emulsions. If used with sensitizing dyes they may be added to the emulsion before or after the dyes are added. The dispersing agents for the silver-halides may be gelatin or other colloid such as water-soluble cellulose derivatives, e. g., hydroxy ethyl cellulose, methyl cellulose, carboxy-oxy-cellulose, low acetyl value cellulose acetate, and the like. The stabilizers may also be employed in gelatin or other colloid, such as polyamides or a mixture of gelatin with a, polyamide as described in United States Patent 2,289,775; polyvinyl alcohol and `ielling compound as described in United States Patent 2,249,537; polyvinyl acetaldehyde acetal .resins and partially hydrolyzed acetate resins described iny United States Patents 1,939,422 and 2,036,092; cellulose derivatives, e. g., cellulose nitrate, cellulose acetate, the lower fatty acid esters of cellulose including simple and mixed esters, ethers of cellulose, and the like, as an under or overcoat for the emulsion, or as a backing layer for the support. Moreover, they may be incorporated in the support for the sensitive emulsion layer or in an intermediate layer between the sensitive emulsion layer and the support, such as the baryta coating commonly used in photographic papers, or they may be incorporated in a protective layer coated upon the emulsion surface, or the otherwise nished photographic material may be bathed in an alcohol or alcohol-water solution containing the stabilizer.

In the accompanying drawing the various iigures are enlarged section views of photographic materials having anti-fogging layers made according to our invention. y

As shown in Figure 1, the support I', which may be of any suitable material such as glass, cellu-l lose ester, synthetic resin, or paper, is provided with an anti-fogging layerl 3, containing one of the 1,3-bis [3-amino-1,2,4triazolel-oxypropenes referred to above. The light sensitive emulsion layer 2 is attached to the anti-fogging layer 3.

Figure 2 illustrates a similar material in which the support I is coated with a light-sensitive emulsion layer 2, and on the latter side there is provided an anti-fogging layer 3 containing one of said 1,3-bis i3-amino-1,2,4triazolel-oxypropenes.

Figure 3 illustrates a lm or plate of which the support l bearson one side the light-sensitive emulsion layer 2, and on the other side an antifogging layer 3 containing one of said 1,3-bis [3amino-1,2,4triazolel-oxypropenes `Figure 4 illustrates a lm, plate, or paper of which the support I is provided with the lightsensitive emulsion layer 2 containing as an antitriazole] -oxypropenes Since: the; Plasencia, off these` new compounds tenl toprevent; chemical, fog` whether they. are

in; rpo ratedil directly: into the emulsion, added to a. separate surface orvsubstratum layenitzis understood, that. the term. photograplrno matei'ialasempioyed herein and in .the appended, claims, is usedfin a generic sense todnoludefeach.

of, thesepossible: applications;

Vaw. moeiiicationsl of` thisv invention will;

OCQulJ--O .13.1.2,1'591'18skilledV in theart andits, theresfcre, understood thatr the patent.` grantedshall;

only be limited by the appended claims..

We claimi.

1.y Af photographic material .comprising a base andxa..lightsensitive silverfhalide emulsion care riad-thereby, said photographie. material contain.- ing, in .foginhibiting amount, a .compound of the general :formula:

wherein R is a` member selected from the class consisting Qf hydrogen and alkyl groups, R1 is a. member selected from the class consisting of' alkyl; arylanciaralkyligroups, and R2 is a memberselected from, the class consisting of hydrogen.. ,allylzand 'alkyl f groups.

2': A- photographic material comprising a base anda light-sensitive silver-halide emulsion carriei thereby, saidphotographic material vcontaining,x` in fog inhibiting amount, a compound for the formula:

CH3 CaHs 0 3i..A.-.chetceraphic material 'comprsne abase.

and.. .flight-,sensitive:silverfhalide emulsion carreQ-thereb-y., said. nhotoeraphiemanai .centaine v f-,Oe nhbitifl.e;A aeomnound .ofthe H-c\ l /CH- N? r\f11frqi\iT =N.r

4; A photographicmaterialcorriprising a base and a light-sensitive silver-halideemulsion oarriedjihereby,saidphotographic material containing-,i n foginhibitingamount, a compound of lthe formula-z CHifllf 5.i A; llctcgranhic material, `cfilfrliufisi.ne as. base,-V

whereinR, is av mjen'ilzier-selectedA from the -class consisting ofwhydrogenandv-alkyl groups, Riis a sar member: selected: from thel class" f'zonsisting.I of alkyl, aryl andvaralkyl groups, andR2 is amember selectedfromthe class consisting oft hydro.- gen, ailyl, and alkyllgroups.

6.v AV photographic .material comprising a base, and a light-sensitive silverhaiide emulsion containing, in fog inhibiting amount, a compound of the formula:

7. A photographic'materialcomprising a base, and a lightvsensitive silver-halide emulsion containing, in foginhibiting amount, a compound of the formula:

\N=l-NH1. HQN.-C=N

10. A' photographic gelatine silver-halide, emulsion containing from about25 mg. to about 500 mg.- per `liter of emulsion of a compoundof'the formula:

N--C--NHz HzNC=N y 1l. A photographic gelatino silver-halide emulsion `containing,from about 25 mg. to about 500 mg, p enliterof emulsion of acompoundf the probableformula:

Then following,references are. of record in the file of. thispatenti,

UNITED STATES-ii PATENTS L Name., Date I. Matthies et a1.` May 13,' 1930 Number