US2432864A - Photographic elements bearing silver halide emulsion layer and adjacent light-insensitive colloid layer containing silver derivatives of azoles - Google Patents

Description

DCC- 16, 1947. 1 w. H. DIMSDALE ET Al. 2,432,864

PHOTOGRAPHIC ELEMENTS BEARING SILVER HALIDE EMULSION LAYER AND ADJACENT LIGHT-INSENSITIVE COLLOID LAYER CONTAINING SILVER DERIVATIVES OF AZOLES F11-ed Jan. 1a, 1945 v 'F/azj SILVER DERIVATIVES OFSULFUR-AZ SILVER HALIDE EMULSION LAYER FILM SUPPORT SILVER HALIDE EMULSION LAYER WATER-PERMEABLE COLLOID LAYER CONTAINING SILVER DERIVATIVES OF SULFUR'AZOLES FILM SUPPORT SILVER HALIDE EMULSION LAYER WATER-PERMEABLE GOLLOID LAYER CONTAINING SILVER DERIVATIVES OF SULFUR'AZOLES SILVER HALIDE EMULSION LAYER FILM SUPPORT y r I I SILVER HALIDE EMULSION LAYER FILM SUPPORT WATER-PERMEABLE GOLLOID LAYER CONTAINING SILVER DERIVATIVES 0F SULEURAZOLES INVENTORS W/LFR/D HAM/DEN D/MSDALE ggd R/OHA no Roa En r Roem/50N' A TTOPJI/E Y Patented Dec. 16, 1947 'PHOTOGRAPHIC ELEMENTS BEARING SIL- `VER HALIDE EMULSION LAYER AND AD- JACENT LIGHT-INSENSITIVE HCOLLQID LAYER CONTAINING TIYES OF AZOLES SILVER DERIVA- `Wilfrid Hampden Dimsdale and Richard VRobert Robinson, Ilford, England, assignors to Ilford Limited, Ilford, England, aritish company Application January 18, 1945,:Se1'ial No. 573,460 In Great Britain February 3, 1944 5 Claims.

This invention relates-to photographic lightsensitive elements, toco-mpounds which serve as improvers for photographic sil-ver halide emulsions, and particularly to compounds which improve the quality of the developed photographic images obtained in such emulsions.

In the production ofphotographic .images in silver halide emulsions, and particularly in the case of emulsions consisting primarily of silver chloride, the maximum image density obtainable is not always so great as may be desired. Moreover,'the .common practice of hot-glazing photographic prints tends to affect adversely the image colour, giving a poor quality black which has a bronzed appearance, and also reduces the effective maximum density obtainable Yin the image.

In British Patent No. 561,875 methods are` described for improving the quality of -the developed photographic images which comprise treating the emulsions With 5-'mercapto tetraz`oles.`

These compounds may be introduced into `the emulsion itself, or into a subcoat, supercoat or backing A.layer,'or 'they may be'included in the Wrapping materials used. Alternatively, the compounds may be applied 'in `solution fto 'the emulsion before or during development, e. g. by including them 'in the developing solution used. These compounds, iso used, .not l'only improve the maximum image density obtainableand serve as anti-bronzing agents, but also reduce the level `of foginthe Adevelopedimage. As stated in the said patent,`- compounds used to reduce the fog level'frequently cause a serious reduction in the speed of the -emulsion, and it is an advantage of the Ycompounds .described inthe said patent that `the reduction ,'inspeed whichthey cause .is not serious. Nevertheless, .in'the case of many Lof :the compounds,v 'some 'reduction in nspeed is caused by their use, as indicated by the figures set out in Table I of the said patent.

There are other classes of compounds which serve to increase the maximum image density obtainable and serve as anti-bronzing agentsamong which are -mercapto-1.2.4-triazoles described .in U. SxapplioationNo. 553,270. These compounds, Wheni'incorporatedin `the emulsion `or, `developer also serve to 'decrease the fog level in the. developed image, and also 'sometimes effect a decrease inthe 'speed l`of the emulsions.

Whilst the method 'ofusing such compounds jdescribed in the `said 111; S. application Serial No.

558,270, filed October 11, 1944, ydoes not lead to a loss in speed of the emulsion, since thecompounds are not. applied, until' the emulsion has alreadybeen developed, thefmethod entails that the user needs to employ special fixing, `,glaz/:ing orothersolutions containing the compounds, It would ,clearly be an advantage for the manufacturer-.to be able to include Jthe `compoundin the photosensitive element as` marketed, providing thatits presence in such element didnotunduly reduce the speed of thephoto-sensitive emulsion.

.The .present invention is concerned With. a methodof including `the compounds in the pho- Ato-sensitive .element itself .in a form such that anytendency .for lthe compoundto reduce the speed ofthe photo-sensitive emulsion .is reduced or -eliminated.

According to thisinvention there is` added to aphotographic emulsion `or toa colloid medium other Ythan'the emulsion which forms a vWaterperr-nealcle layer vin a photographic .element including a silver halide .emulsion layer, a silver derivative of a `compound which, when added in itsfree state, or in the4 state of its alkalimetal derivative, improves the quality 'of photoygraphic. images developed in such emulsion layers. L The term added is intended to mean `that the siiver derivative ,itself is added orthat reagents are added which reactamong themselves to form the `silver derivative. The mere addition ofthe free compound or of fits alkali-metal derivative to a silver. halide .emulsion with the consequent Vpossible formation of somesilverde- .rivaux/e by react-ion with part of the einerv ,of

the emulsion itself =is lnot included Withnthe meaning of the term and does not give the same results as are'obtained bythe process of this invention.

The term silver derivative is intendedto mean a derivative resulting from replacement of hydrogen `in the said compound by silver.

In a preferred form Yof the invention the silver derivatives are added to colloid media which are to be used for coating layers in Contact Withthe silver halide emulsion layer or layers. For example, the silver derivative may be included in Aa supercoat layer, e. g., a colloid layer-coated on top of the photographic emulsion layer and forming, for example, anouter layer of the element, or may be .includedin a subcoatlayer, e. g., a colloid layer v lying between a photographic'emulsion layer and a support layer, or may be included in an inter-layer between two emulsion layers. It may, however, be present in other layers, for example a backing layer.

The pho-tographic elements described in the preceding paragraphs are illustrated in the accompanying drawing wherein:

Fig. 1 is a cross section of a film bearing a silver halide emulsion layer` and a superposed layer containing an anti-bronzing agent of the type described below;

Fig. 2 is a cross section of a similar lm wherein the silver halide layer is outermost;

Fig. 3 is a cross section of a similar film wherein a colloid layer containing an anti-bronzing agent is disposed between two emulsion layers; and

Fig. 4 is a cross section of a modified lm wherein the two layers are on opposite surfaces.

Referring more particularly to the drawing, in Fig. 1 a iilm support l is provided with a silver halide emulsion layer 2 on which there is disposed a water-permeable colloid layer 3 containing an anti-bronzing agent of the type disclosed below.

In Fig. 2 a lm support I is provided with a water-permeable colloid layer 4 containing an anti-bronzing agent as herein disclosed on which there is disposed a silver halide emulsion layer 5.

The element of Fig. 3 consists of a nlm support I bearing silver halide emulsion layers 6 and 8. between which there is disposed a water-permeable colloid layer 'l containing an anti-bronzing agent as herein disclosed.'

The element of Fig. 4 consists of a lm support l bearing a silver halide emulsion layer 9 on one surface and having disposed on the other surface a water-permeable eolloid layer l containing a herein disclosed anti-bronzing agent.

It is desirable, especially where the silver derivative is included in a supercoat or in the emulsion layer itself, that it should be in a very fine state of subdivision in the layer in which it is incorporated. Thus, a convenient method of use is to form the silver derivative in situ in the colloid medium in which it is to be dispersed, for example by the double decomposition of a soluble silver salt and an alkali-metal derivative of the compound in a gelatin medium.

The invention may be applied to all varieties of compound which are capable of improving the quality of the developed image and which will form silver derivatives.

The following are typical classes of compounds which may be used, as their silver derivatives, in accordance with this invention.

(a) Compounds of the type described in British Patent No. 561,875. These are -mercapto tetrazoles and specific examples are:

1-phenyl-5-mercapto-tetrazole 1-a-naphthyl--mercapto-tetrazole 1--naphthyl-5-mercapto-tetrazole 1-p-diethylamino phenyl-5-mercapto-tetrazole l-o-methoxy phenyl--mercapto tetrazole l-p-chlor phenyl-5-mercapto-tetrazole 1benzyl5-mercapto-tetrazole 1-cyclohexyl-5-rnercapto-tetrazole 1-methy1-5-mercapto-tetrazole 1-ethyl-5-mercapto-tetrazole (b) The -mercapto-1.2.4-triazoles described in U. S. application Serial No. 558,270, referred to above. Specific examples of these are:

1.2-dimethyl-5-mercapto-1.3.4-triazole 1-ethyl-2-methyl-5-mercapto-1.3.4;-t1fazole 1-phenyl-2-methy1-5-mercapto-1.3.4triazole l-phenyl-5-mercapto-1.3.4-triazole l-benzyl-S-mercapto-1.3.4-triazo1e 1 -methyl-2-ethyl-5-mercapto- 1.3.4-triazole 1-methyl-2-n-hexyl--mercapto-1.3.4-triazole l-p-hydroxy phenyl-2-methyl-5-mercapto-1.3.4-

triazole l-p-arnino phenyl-2-methyl-S-mercapto-1.3.4-

triazole 1a-naphthyl-2-phenyl-5-mercapto-1.3.4-triazole 2-a-naphthyl-5-mercapto-1.3.4-triazole 1.2-diphenyl-5-mercapto-1.3.4-triazo1e (c) Heterocyclic nitrogen compounds containing two nitrogen atoms in the ring and one, two or three sulphur atoms attached to carbon atoms which are in fic-position to the nitrogen atoms (compounds containing a single sulphur atom linked to a carbon atom which is a to both nitrogen atoms are included but are generally less eflicient). Examples of this class of compound are:

2.5-dimercapto-1.3.4-thiodiazole 2-mercapto-5-amino-1.3.4-thiodiazole 1-mercapto-4-hydroxy-phthalazine 1.4-dim-ercapto-phthalazine 2.5-dimercapto-3-methyl-1.3.4-thiodiazole 2-hydroxy-4-mercapto pyrimidine 2 :4-dimercapto-pyrimidine 2 :4-dimercapto-quinazoline Trithio barbituric acid (d) Mercapto hydroxy diazoles, an example of which is:

2-mercapto-4-phenyl-5-hydroXy1.3.4 thiodiazole.

(e) Dimercapto monazoles, an example of which is:

2.4-dimercapto quinoline.

(f) Mono mercapto monazoles, examples oi which are:

2-mercapto-benzthiazole 2-mercapto-benzoxazole 2-mercapto-quinoline 2-mercapto-6-7-benzbenzthiazole (i. e., naphthathiazole) 4-mercapto-quinoline.

EXAMPLE I 1 gram of 1-phenyl-2-methyl-5-mercapto- 1.3.4-triazole was dissolved in 3.6 ccs. of a 40% aqueous solution of sodium carbonate (Cryst). This solution was added to 250 ccs. of a 4.4% solution of gelatin (containing a small quantity of dispersing agent) and made up to 500 ccs. with water. 77.7 ccs. of a 1% aqueous solution of silver nitrate was added to 250 ccs. of a 4.4% solution of gelatin (containing a small quantity of disture wascooledto'dorm afsrnall amountrofronn- -Jal'd'ehyde a'd'ded and ttlfien, 1 after' stari'ding; was coated at 80 F. asA afsupercoatr (fai afstandard silverfbromideemulsion-'asmsedi 'or aryfbro- Timide prlinting paper.Y 4"and T:Cb -a ta 'da-rdrsi-lver chloride Iemulsiorifasyusediirikordiriary ffooritact" Aor gas1ight printing paper; ftheV ul'sion ilayers `being carried f onfpaper 1-s',upp'cr-ts. Testfsaniples `of the fdriedfcoatings were 4exposedrbehindaidensity rstep wedge,` developed and xfed. :'JSome Isamples Wereidried normally ramd othersilwere dried on -alcommerc'ial hotiglazin'g machine.

'Control samples, 'in fwhi'ch the triazole voorn- :p'oundfwas Lomitted Vfrom @the gelation "superooat, -were similarly processedaand'tne speed andimanimum image density (Dmax) Were determinedior Fthe I.various1samples. The fre's'ultslobtained were .fassetrout1in-.the` following" Tabler:

vTable .Y

.randltheereslts.nbtainedfwere .fasssettoufzfixtzthe ses SilverBroinidCoatings4 `Si1verChlorldlGoatings following Table II:

AZThese speed values 'are calculatedas before. Again "there is no measurable' loss in Jspee'din vfthe jcaseof the silver chloride emulsiorrcoatingsj'b'ut there is `some loss in-thecase'of the silver bromide emulsion coatings. MHowever,l a comparable test on the silver bromide material =using Ja superco'a't containing the free compound(i."'e.,riot"'asithe Asilverderivati-ve) sh'ovved "a speed value only-T5 lof* that of 'the 'test "sample o'f the above Table"'[I. 'The testsamples `in all cases vshowed* 4a markedly llessdegree of bronzing Aafter hot-glazing, `than "the "control *rt-should 1'te pointedout-therme speed' vfigures given V:in this "example `are not 'comparable with 1130 I "PatenNo': 561;'8'75. `thoughthe ysame"compound is `in use; "for the reason that 4Vin I'the' present 'case very much larger quantities of the compound have Ebeent'aken in ythe' examples-and 'the-fernulsionsl used are different.

11i-EXAMPLE rIII 'free generar procedure- Forex-amples'"nano 1111 Vwas"followed using concentrations-oi 1-`partfdf Vthe @silver-derivative! "in- 50'00 Cparte f'i fthe fge tin Ksincerco'at solution, |other compounds' than Table `III .'Slver Broniide Coatings VSilver Chloride .Coatings i.

AD normallyJ ""Dvm hot- "l 'Dm normally r"D hot- Compound mariee gled "d1-ieu lzed Control Test Control Test Control Test Control Test 2.4-di-me1capto pyrimidine 1. 91 1.94 1. 70 2.05 1. 74 1.86 1. 46 2.00 1-mercapto-4-hyd10xypl1thalazne l. 83 1. 94 1. 58 1. 99 1. 75 l. 90 l. 45 l. 98 Z-mercapto-benzthiazole 1.83 1.89 1. 58 1. 94 1. 75 1. 86 1. 45 1. 97 2.4.dimercapt0 quinoline 1.82 1.85 1.71 1.90 1.80 1.83 1.53 1.86

parable test on the silver bromide material using a supercoat containing the free compound (i. e., not as the silver derivative) showed a speed value only 1% of the speed of the test sample of the above Table I. `The test samples in all cases showed a markedly less degree of bronzng after hot-glazing than the control.

EXAMPLE II The procedure given in Example I Was followed with the variations that the compound used Was l-phenyl--mercapto-tetrazole, it was dissolved in 5.0 ccs. of the sodium carbonate solution and the quantity of silver nitrate solution taken was 95.5 ccs. All other conditions remained the same EXAMPLE IV The silver derivative of lr-phenyl--mercapto tetrazole was prepared and added in finely divided condition to silver chloride and silver bromide emulsions, one part of the silver derivative being added per 1000 parts of emulsion. Tests were made as before and gave the results set out in Table IV.

The bronzed effect of the control samples, shown particularly on the hot-glazed samples, was substantially eliminated in the test samples and, though some loss in speed Was caused by the addition of the silver derivativeto the bromide emulsion, this loss was less than is caused by the addition of the free compound. An increase inv Dmax was effected in all cases.

What we claim is:

1. A photographic element comprising a silver halide emulsion layer and, in Contact therewith,

a Water-permeable light-insensitive colloid layerl which contains a silver derivative of a compound selected from the class consisting of -mercaptotetrazoles, -mercapto-1.3.4-triazoles, diazoles containing up to three sulphur atoms attached to carbon atoms which are in a-positions to the cyclic nitrogen atoms, mercapto hydroxy diazoles, dimercapto monazoles and monomercapto monazoles.

2. A photographic element comprising a silver halide emulsion layer and an outer water-permeable light-insensitive colloid layer in contact with saidemulsion layer, said outer layer containing a preformed silver derivative of a compound selected from the class consisting of 5- mercapto-tetrazoles, 5 mercapto-1.3.4-triazoles, diazoles containing up to three sulphur atoms attached to carbon atoms which are in aL-positions to the cyclic nitrogen atoms, mercapto hydroxy diazoles, dimercapto monazoles and mono mercapto monazoles.

3. A photographic element comprising a silverhalide emulsion layer of which the predominant silver halide is silvei` chloride and, in contact therewith, a water-permeable light-insensitive colloid layer which contains a silver derivative of a compound selected from the class consisting of -mercapto tetrazoles, 5 mercapto 1.3.4-triazoles, diazoles containing up to three sulphur atoms attached to carbon atoms which are in a-positionsvto the cyclic nitrogen atoms, mercapto hydroxy diazoles, dimercapto monazoles and mono mercapto monazoles.

4. A photographic element comprising a silver halide emulsion layer of Which the predominant silver halide is silver chloride and an outer waterpermeable light-insensitive cclloid layer in contact with said emulsion layer, said outer layer containing a silver derivative of a compound selected frum the class consisting of 5-mercaptotetrazoles, 5-mercapto-1.3.4triazoles, diazoles containing up to three sulphur atoms attached to carbon atoms which are in na-positions to the cyclic nitrogen atoms, mercapto hydroxy diazoles, dimercapto monazoles and mono mercapto monazoles.

5. A photographic element comprising a paper support carrying a silver halide emulsion layer and an outer Water-permeable light-insensitive colloid layer in Contact with said emulsion layer, said outer layer containing a silver derivative of a compound selected from the class consisting of 5-mercapto-tetrazoles, 5-rnercapto-1.3.4triazoles, diazoles containing up to three sulphur atoms attached to carbon atoms which are in a-positions to the cyclic nitrogen atoms, mercapto hydroxy diazoles, dimercapto monazoles and mono mercapto monazoles.

WILFRID HAMPDEN DIMSDALE. RICHARD ROBERT ROBINSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,057,764 Brunken Oct. 20, 1936 2,066,099 Dieterle Dec. 29, 1936 2,221,805 Leermakers Nov. 19, 1940 2,377,375 Russell June 5, 1945 FOREIGN PATENTS Number Country Date 390,037 Great Britain Mar. 30, 1933

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