BE699375A - - Google Patents

Description

  

  



    NEW $ PROTOCRAPHIC EMULSIONS WITH HIGH RESOLVING POWER
The present invention relates to novel light sensitive photographic elements and more especially to silver halide photographic emulsions with which high resolving power reproductions can be obtained from fine grain originals.



   Dyes, especially yellow dyes, have often been incorporated into light-sensitive gelatin and silver halide emulsion layers to reduce image smearing upon exposure. This process is very effective when the decrease in oontrast and sensitivity due to the presence of the dye has been made acceptable for the purpose.

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   However, this approach is not suitable when emulsion layers are required for the production of resolving power and definition images as required by printed electronic circuits and electronic products, particularly for miaromini. - aturization. For this purpose, we have become accustomed to @rejetor irages with the aid of a microscope on a so-called Lippmann emulsion (that is to say a silver halide emulsion whose average grain diameter is at most 0.1 4).

   For some works requiring a resolving power 'raised, one can use, even of our joura: the proceeds to the oollodion bumide,
$ Antihalo backbones are required for earlier products with high resolving power. However, the sharp edges of glass plates scratch them easily and the removal of the antihalation layer is very desirable.



   A subject of the present invention is therefore in particular the preparation of a new Lippmann emulsion, which, lying on a support, allows greater adjustment of the width of the image lines, which has an exceptionally high resolving power and definition, and which does not require any antihalation layer.



   The novel Lippmann emulsions with silver halides and hydrophilic colloldal binder according to the invention are remarkable in that they contain a high proportion of at least one eliminable light-absorbing dye, and exhibiting practically complete photographic inertia. These emulsions are advantageously coated on suitable supports preferably not having any antihalation layer so as to obtain photographic products used to produce reproductions of images at

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 exceptionally high resolving and definition power. The removable and photographically inert dye absorbs light of the spectral composition chosen for the exposure of the photographic material.

   By "removable dye" is meant a dye which can be removed during photographic processing by dissolving it in water or alkaline developing solutions, or by bleaching or decolorizing the dye with said solutions. The exhaustions are advantageously applied in thin layers on a suitable support, to usually obtain a dry layer thickness ranging from approximately 24 to 6.

   The proportion by mass of silver halogemides relative to the hydrophilic coloidal binder in the Lippmann emulsion according to the invention is advantageously at least about 1.3 and preferably about at least 2.1, and the concentration of the emulsion in light absorbing dye is sufficient to obtain a layer having a density of 0.15 units per micron of thickness based on the spectral composition chosen.

   It has been found that the use of the emulsions according to the invention is suitably advantageous, since the increase in the silver halide content compensates for the loss in sensitivity and in contrast which results from the use of a large quantity of dye,
Any hydrophilic collotal binder used in photographic emulsion layers can advantageously be used in the new Lippmann emulsifier according to the invention, for example, gelatin, albumin, cellulose derivatives and various synthetic polymeric binders.

   Polymeric binders include polyvinyl alcohol or a hydrolyzed polyvinyl acetate, as described in the French patent

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 869,973 a highly hydrolyzed cellulose ester, such as cellulose acetate hydrolyzed to an acetyl content of 10-26%, as described in US Pat. No. 2,327,808, a cellulose acetate and water-soluble ethganolamine, as described in U.S. Patent 2,322,085, a polyaorylamide having a combined acrylamide content of 30-60% and a specific viscosity of 0.25-1, 5 or an imidized polyacrylamide of identical acrylamide content and viscosity, as described in.

   French Patent 1,055,759 zein as described in French Patent 1,000,682, a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in United States Patent 2,768,154. or containing oyancacetyl groups, such as the oopolymer of vinyl oyanoacetate and vinyl alcohol, as described in French patent 1,155,898; or a polymeric substance which results from the polymerization of a protein or of a saturated alylated protein with a monomer having a vinyl group, as described in French patent 1 151 480.



   Any mixed or pure silver halide is used to make the Lippmann emulsions according to the invention comprising silver browide, silver chloride, silver iodide, silver chloroiodide, bromoiodide. silver and silver ohlorobromoiodide, etc., Silver halide emulsions in which the halide comprises more than 90 mole% bromide and the silver halide grain size of which is up to about 0 , 1 are particularly advantageous *

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The upper limits of the proportion of silver halide to hydrophilic colloidal binder and of the declared light absorbing concentration are due to practical considerations.

   Thus, the proportion of axgont halide to the binder can be as low as the preparation of the emulsion can withstand, taking into account the fact that it is desirable to avoid the formation of coarse grains during precipitation and defects, such as those known as - "black spots" due to grains of silver halides touching each other and developing spontaneously (i.e. without exposure), and developmental defects, such as chemical haze and excessive grain growth.

   In order to obtain the new emulsions according to the invention, it is advantageous to use a proportion by mass of silver halide relative to the hydrophilic colloidal binder of between approximately 1: 3 and 8: 1, A very advantageous proportion range is between 2: 1 and 6: 1.



   The upper limit of concentration of light absorbing dyes depends to some extent on the given dye. For example, some dyes crystallize more easily from gelatin mixtures than other dyes. Too much dye can also prevent the collotdal binder from spreading properly when coated on its backing.



   The colorant chosen should be a colorant before minimal harmful effect (such as haze or desensitization) on the emulsion and should be easily washed off the emulsion layer or bleached during processing. The density of the dye in the layer can be measured

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 directly or can be calculated from the density and volume or from the dye solution used during the preparation of the layer or from a solution obtained by removing the dye from the layer * One can easily calculate the thickness of the dry layer from the coating masses of the hydrophilic colloidal binder and the silver halide, as well as the specific mass of these substances.



   In the case where the support is made of paper, the dye is preferably a dye which is substantive for the colloidal binder or which can be etched on it so that it does not seep into the paper.



   The light absorbing dyes used in the Lippmann emulsions according to the invention can be any well known removable light absorbing dye used in photographic materials. Among these are particularly advantageous oxonol dyes, as described in United States patent 2,611,696, styrylic dyes, as described in United States patent 2,622,082, dyes of the pyrrole series as described in French patent 1,053,982, merocyanines, as described in French patent 992,994, dyes of the amazonaphthalene series, as described in French patent 1,228,072, merocarbocyanine dyes , as described in French patent 1 221 619;

  oxanol dyes, as described in US Pat. No. 3,247,127, oxonol dyes, meroarbo-cyanines and merodicarbocyanines, such as described in French Patent 1,359,682 dyes derived from substituted 3-pyrrocolines as described in US Pat. USA 3,260,601; 4-pyenylazo-2-phenylorazoles as described in US Pat. No. 2,852,376; azo dyes as described in French patent 1,152,693, and the like.

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 EMI8.1
 



  Particularly effective stains include those represented by the following Formulas I, II, III and IV.
 EMI8.2
 
 EMI8.3
 where R represents an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, etc., or an o = Eoalkyl group, such as oarboxymethyl, oarboxyethylo, carboxypropyl or a sultoalkyl group, such as sultoethylpeulfopropyl, sultobutylop etc. , Z represents the non-metallic atoms essential for oo:

  plete one
 EMI8.4
 benzoxazole series heterooyolic ring (including benzoxazole
 EMI8.5
 and benzoxazole substituted with groups such as methyl, ethyl, phenyl, m-thoxy, ethoxy, chlorine, bromine, etc.) or a serial ring of bonzoxazola which has a 8UhKti '<. Kt sulfo on the ba6ne ring as well. that a
 EMI8.6
 or more of the single substituents mentioned above, such as when
 EMI8.7
 R represents an alkyl group, Z represents the benzoxazole nucleus aubalitué with a sulto ut group when R represents an oarboxyalooyl group or a sulfoalooyio group, Z rqtl) rc-feel the non-nietulllqueu atoms necessary to complete a honzoxxzolo ring j Q represents the non-atoms metallic. necessary to complete a heteroa, yoliqu6 ring of the mlfophë! ylpyrazblinono series and n is an integer ranging from 1 to 3.

   
 EMI8.8
 

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   or. Q and n are as defined above,.
 EMI9.1
 



  (oxonol dye) where. R2is a carboxyalkyl group in which the oarboxy substituent is attached to an alkyl group having 1 or 2 carbon atoms; R3 is a member selected from an alkyl group having 1 to 8 carbon atoms, such as methyl, benzyl, ethyl, propyl, isopropyl, butyl, secondary butyl, tertiary butyl, heryl, ootyl, cyclohexyl, etc., an aryl group, such as phenyl, 2-methylphenyl, 2-methoxyphenyl, 2,4-dimethylvinyl, etc. ;

   n is an integer ranging from 1 to 3; x is a hydrogen atom or an alkyl group containing from 1 to 4 carbon atoms such as methyl, ethyl, propyl, butyl, etc., such that n there is no more than a single X which is an alkyl group.
 EMI9.2
 where R4 represents a hydrogen atom, a lower alkyl group (sulfonated or not), such as methyl, sulfoethyl, sulfopropyl, propyl, aulfobutyl, etc. a lower alooxy group such as methoxy, ethoxy, propoxy, butoxy, eta., a benzene ring which may be condensed with the pyridine ring of the

 <Desc / Clms Page number 10>

 
 EMI10.1
 pyrrQooline group etc. ;

   R5 and n6 may each represent an alooyl group (sulfond or not) such as methyl, sulfomethyl, ethyl, propyl, isopi'0pylo, 8ultopropylo,! T-Dutyl, sulfobutyl, etc., an aryl group, (au1to6 or not) such that phenyl, 4-mlfophenyloe, 4-tolyl, 2-sulfo-4to1yl., 5-methoxyphenylo, 4-aoetamidophétylOt etc., an ary3alaoyla group, (sulphone or not), such as phé1Vlmethylet phúI \ 11étb, yl, 4-phé11ylpropyle -aulfophylethyl, 2-aulfopherylpopyle, etc., and Z '831; a group of atoms *, which reunited with the nitrogen of the pyrrooolino ring completes a conjugate chain and ends with another nitrogen atom or with an oxygen atom. All dyes may have one or more sultonic acid constituent or molecules in their molecule and may also have one or more carboxyl groups.



  The following examples of typical dyes are advantageously used 1. 3- (3t5-disulfobanzarido) -4; 3-dt2'12- (3A) benzoxaasolylidans) .. ethyliden! 7-1-pbényl-2-pyr4zo1in-5-ono 2 . 3-Mthyl- ° 3 - $ ulioethyl-2 (3) benzoxazo: .ylid8ne) rtylid8n .. l-2-mlfophenyl-2-pyrxzolin-5-ono 3. 4-éÎ3-ethyl-2 (3X) - bonzoxàzolylidéno) ethylidén é-3-methyl-1- (p-sulfophenyl) -2-pyrazolin-5-one, monoaultonée 4. 4-ù- (3-éthyi-2 (3E) -bénzoxazolylidéno) -2-butéryiidén% 7 -3-Methyl- 1- (E-Sulfophel \ Yl) -2-pyrazolin-5-one, mon'J.uifon; a 5.4-El3-A-aarboxyethyl-2 (3X) -bonzoxazolyiidéno) -ethylidén é -3m6thyl-1- (2-xulfophérylj-2-pyrazoiin-5-one 6. ° - (3-j3-dthyl-2 (3H) -benzoxazolylidèns) -2 butezLYliden -raetll.



  1- (h-sulfopheryi) -2-pyrazoiin-fi-one

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 EMI11.1
 7, 3-methyl-4- 6 - (4-sulfobutyl) -2-bsnzoxazolirqlidèn1 t3néopsntylèns-24-haxadiérlidène -1-h-xulfophenyl-2-pyrazolin- 3'-oa <t 8. 3- # ethyl-4- ± 6-L3- (2-sultoethyl) -2-benzoxzolilidèni7-1.3n3opentylne-2,4-hexadiezYZidèns -1-2-mlfophenyl-2-pyrazolin- 5-ano 9. 3-methyl-4- (6 .. ( ..carboryetïyl) -2-banzoxazolilidn 1. néopentylèna-4-hsxadirirylidènE -1-2-xulfophenyl-2-pyrazolin- 5-o re 10. 3-dt $ Yl- ° .- 6- (4-sulfobutyl) -2 -bsnxoxasolirylidèns-1,3neopentylene-2-butenylidene) -1--2ultophenyl-2-pyrazolin-5-on.



  11, bi i-butyi-3-o * boxymé <hyl h6xahydyo-2t4t6-trioxo "5-Fyrimidi !! e) '-' trimethinoxonol 12. bixfl-OE-oulfophenyl) -3-methyl-2-pyrazôlin-5- one (4à7-trimethin-
 EMI11.2
 oxonol
 EMI11.3
 13. bia1- (n-auli'ophenyl) -3-aaethyl2-pYraxolin-5-one (4,% - pentam6thin ..
 EMI11.4
 oxonol, eto.
 EMI11.5
 14 * bia (1-butyl-3-aarboxyEethyl hoxa% dro-2,4,6-trioxo-5-pyrimidine) -:

   trimethinoxonol 15. bi s (1.-buty-3-cr, rbozywdthyl haxabydro-2,4 6-trioxo-5-pyrimidine)
 EMI11.6
 pentamethinoxonol
 EMI11.7
 16. bie (1-aarboxymethylhexahydro-3-1,1-ootyl-2,4 6-trioxo-5 pyrimidins) - 3-methylpentamethinoxonol 17. bia (1-n-butyl-3-curboçymëtivlhexahydro-24: 6trioxo-5pyrimidine) trimethinoxonol 18, (3-ethyl-2-benzoxazole) iodide (1-n acid) 6thyl-2-phéayl-3pyrroooline mlfoniquc) dimethinecyanine 19. biu aoetate (aoid l-aëthyl-2-pMTtyl-3-pyriquroooline) a methinooyanine

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 EMI12.1
 20. 1-butyl-3-oarboxymethylhexx% ydro-5-Ô- (aoide 1-m & tb11-2-ph41- 3-oyrrooolirvl xulfoniquw3allylidèn-2l4f6-txioxopyriuidina 21. acetate de (1-ethyl-2,5-ààm4thyl-3 -pyiiolo) (1-methyl-2phenyl-3-1yi'reaJlin0 8ultonic acid) methineqfanine 22.

   3-i-am acetate% hylaminoboncylidéno-l-methyl-2-whànyl-3eulfopyryoaoliniua 23. 4- (4-9-4odeoyloxy-2-aulfo> h'ryla% o) -µ-hydrosy-2-phé1qrloxaSol * (sodium ael) 24. 4- (3-oarboxyphéxylazo) -2- (1-aarboxyphéXyl) -µ-hydroxyoxa% ol * 25. 5-anilinowethylén # -3- (i-àim4thylamiiw <thyl) rhoàanino 26. 5 * * aoétaniiido tatylna-3 ('ài.methylaminsetirl) rhodanine 27. (2-dimdtàylamrno6thyl) -5-pigridirmtà, y2bns-rhodanine.



  Lee col. Oranta 25, 26 and 27 above present dyes. lumi8xe b8orbent, aubat1tuéa by a dialooylaarinoalooyl group, roof described in French patent 1,444,772, for example lea dye8 h4mioxonol 8ubstituted. by a dialooylaminoalool1e group.



   Light absorbing dyes are incorporated into emulsions according to the invention by the usual methods used to incorporate *
 EMI12.2
 Light absorbing dyes with hydrophilic oils for coating filters of photographic products. The dyestuffs according to the invention are usually soluble in water, however, other usual solvents, such as ethanol, pyridine, etc. are also advantageously used.



  As will be noted in Example 1 below, some colorants in their soluble form are advantageously added to the emulsion and they are stirred carefully until they are dissolved in the water contained in the emulsion.

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   When coating the emulsion on a paper backing, mordants are advantageously added to it to prevent the dye from passing from the emulsion into the paper. To this end, the dyes having acidic solubilizing groups are advantageously mordanted by any well-known basic mordant, including those described in French patents 1,168,210, 1,053,767, 982,994 and to the patents. of the United States of America 2,768,078, 2,531,468 and 2,531,469, etc. Particularly effective are the bites.

     described in French patent 1,168,210, prepared * by concentration of a compound of polyvinyloranol or of certain copolymers with styrene or alkyl methacrylates,
% Emulsion laws according to the invention are optically sensitized by any well-known optical sensitizer comprising cyanines and merocyanines as described in French patents 712 995, 729 097, 718 471, 741 502, 808 598, 942 838, 972 109, 1,017,981, 1,115,402, 1,116,632, and 1,107,475 as well as the certificate of addition 70,503 attached to French patent 1,107,457, and certificate of addition 48,226 attached to French patent 793,722 .

   



   An advantageous product according to the invention comprises a Lippmann emulsion sensitized to green. In photograpbiquea products which are spectral sensitized, it is convenient to choose a light to expose the emulsion layer which contains wavelengths predominantly of the spectral sensitization region of the emulsion.

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   The emulsions according to the invention are advantageously treated with salts of noble metals, such as rathenium, rhodium, le.palladium, iridinium, and platinum, as described in French patent 983,991 and in United States patents. America 2,566,245 and 2,566,263.



   Emulsions can also be chemically sensitized with gold salts, as described in US Pat. No. 2,339,083 or stabilize them with gold salts as described in US Patents 2,597,856 and 2,597,915. The emulsions according to the invention can also contain the thiopolymers described in US Pat. No. 3,046,129.



   Said emulsions can also be stabilized with compounds * of mercury, triazoles, azaindenes and disulfides. quaternary benzothiazolium compounds, zino and cadmium salts which are described in the indicated references of column 20, line 51, to column 21, line 3, of US Pat. No. 3,046,129.



   The emulsions according to the invention can be tanned with any suitable tanning agent for hydrophilic colloids such as gelatin, including tanning agents such as formaldehyde, a halogen-substituted aliphatic acid such as mucochloric acid, a compound having several groups of acid anhydride, a bis-ester of a methansulfonic acid, a dialdehyde or one of the derivatives of sodium biaulfite, such as ss-methylglutaraldehyde-bis-bisulfite se xamide, such as trimethhlene-bis ( 1-Aziridneoarboxamide), etc., as described in column 21, line 32 to line 61, of U.S. Patent 3,046,129.

   

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 Advantageously used for the preparation of the layers
 EMI15.1
 omuls any customary coating agent such as those ddarita columns 2 'and 22 of the last patent mentioned above.



   Said emulsions are 0QUche on any support usually used for photographic products including glass, cellulose acetate, cellulose nitrate, synthetic resins.
 EMI15.2
 (eg polystyrene, polyethylene terephthalate etc.), paper, etc.



   The following examples illustrate the invention.



  EXAMPLE 1. -
An emulsion of 50 g of gelatin and 88 g of silver bromide is prepared for a total volume of 1400 ml. The precipitation conditions are adjusted to obtain an emulsion with an average seed diameter of about 0.06. Information on suitable precipitation conditions can be found in "Small Soale Preparation of Fine Grain Photography Emulsions" by B.H. Crawford, N.P.L. Notes on Applied Science
 EMI15.3
 ne 20, 1960p and in the publication of Porfilov, N.A. Novlkova, N, .R. and Proko ± Yevai EoI., Trav. Inst. Rad. Chlopin, 7, 257; 1956. The emulsion is sensitized with 0.25 g of -metbyl-23'-diethozathiazolooarbocyanina iodide, which gives a particularly strong spectral sensitization.
 EMI15.4
 the interval 510 - 530 at.

   Then 38 of solid dye n 12, olo8t-à-die bis (3-mthyl-t (p-sultophdryl-2-pyraxolin-5-one (4) triWé with agitation thinoxonol) are added to the emulsion at This dye is dissolved for 15 ° C. and the resulting strongly colored emulsion is then coated on a glass plate to obtain a dry layer 5 thick.

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   exposes the plate to a resolving power test image, reduced with a microscope objective. The light is imparted by a tungsten filament lamp filtered with a Kodak Wratten No. 16 Filter for the green gap, so that the formation of the latent image occurs only in the gap actually absorbed by the absorbent dye.

   The layer is developed by a p-methylaminophenol and hydroquinone developer, such as Kodak Developer D-19 to give crisp images) the quality of the image also changes greatly if the exposure is varied. which gives advantageous working tolerances * The interval of the line width * correctly reproduced with a single exposure value is also increased. Calculation of the density of the untreated layer at 520 µ gave a value of 0.4 per micron of dried emulsion thickness. Identical results are obtained when other usual black and white developing solutions are used.



  EXAMPLE 2. -
Results identical to those of Example 1 are obtained; the said example is repeated using approximately equivalent amounts of dyes 1, 2, quane 3, 5, 14, 11., 23, 24, 17, 25, 26, and 27 in separate emulsion fractions in place of dye 12 used in Example 1.



   It can be shown in an identical manner that these green light absorbing dyes as well as others of the same type are advantageously used in other Lippmann emulsions according to the invention using silver bromide and other halides. 'silver (either without optical sensitizer, or with green sensitization with the same or another

 <Desc / Clms Page number 17>

 optical sensitizing dye), dispersed in gelatin or other hydrophilic colioid binder in which the mass ratio of silver halide to hydrophilic colloid is in the range of from about 2: 1 to about 8: 1 EXAMPLE 3 ...



   Example 1 is repeated but using an optical sensitizing dye in the orange region of the spectrum (i.e. in the range of about 580 to 600 m) in place of the green sensitizer of the spectrum. Example 1, and using colorant 12 in combination with approximately equivalent amounts of colorants 4, 6, 10, 13, 15, 17 and 22 in separate emulsion fractions. Exposures to the resolving power test image are made using a tungsten filament lamp with an orange-colored Xodak Wratten Filter # 24 as a light source instead of the Kodak Wratten Filter # 16. a development identical to that of Example 1, have a high resolving power.



  EXAMPLE 4. -
The procedure is identical to Example 1 but using an optical sensitizing dye in the red region of the spectrum instead of the sensitizer of Example 1 and using instead of dye 12 approximately equivalent amounts of the dyes. 7K, 8, 9 and 21 in fruotiona distiontes emulsion. The resolving power test image was exposed using a tungsten filament lamp with a Kodak Wratten No. 29 filter colored red as the light source.

   High resolving power images identical to those obtained in Examples 1, 2 and 3 are obtained by developing with usual developers,

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Note that we observe no halo in the images developed in the products)! photographs according to the invention of Examples 1, 2, 3 and 4 despite the fact that these products do not contain any antihalation layer.



  The elimination of the need for antihalo coatings in photographic products is an important technical advance, especially for high resolving power plates where no halo can be tolerated. As we mentioned above the antihalo backings, particularly on glass cladding, are prone to scratches and holes caused by the corners and quickly bordered the glass cladding when handling * This is why the removal of these backends .. eliminates a potentially important if not important source of faults.

   Given the exact conditions required for high receive power and high image sharpness, especially in the field of manufacturing micominiaturized electronic compounds and circuits, it is obvious that a halo cannot be tolerated in reproductions of images. and defects such as scratches and holes. The emulsions according to the invention are valid because they do not give any halo even without the presence of oouohea antihalation and because they give images of exceptionally high resolving power and great clarity.



   The following example further illustrates the advantages presented by the invention.



  EXAMPLE 5.-
An emulsion is produced as described in Example 1, but in which the percentage of silver bromide in relation to the gelatin is approximately 1: 3, it is oouohe on a glass plate having

 <Desc / Clms Page number 19>

 an antihalation backbone. The antihalation backbone is then carefully removed from half of the plate. A parallel treated screen is then oopied by contact on the emulsion layer using a sensitometer as the light source. The printing is carried out in such a way that half of the plate with the antihalation layer and half of the plate without said layer receives identical sensitometric exposures.

   After photographic development as described in Example 1, a comparison of the reproduction of. treated parallels even at the end of strong exposures shows that there is no halo or silver developed in areas where there is no image, i.e. between parallel lines consecutive reproduced on half of the plate from which the backbone was removed.

   When repeating Example 5 using the same emulsion but without dye, the reproduction of the parallel line image of the half of the plate where the backing was removed prior to exposure is completely obscured by the halo due to - , silver development of the exposed silver halide in the gaps. higher and intermediate exposure. This means that high resolving power emulsions outside the invention are inoperative above a sufficient exposure interval when no antihalation backbone feature is provided on the photographic plate.

   A comparison of the images obtained on a previous product (with an antihalation backbone) with the images obtained on the products according to the invention (either with or without an antihalation backbone) shows that those obtained with the products according to the invention exhibit a power significantly higher resolution and definition than those obtained with the previous product.



   Of course, the invention is not limited to the embodiments described which have been chosen only as examples.



    ' -ABSTRACT-
The objects of the present invention are in particular "the) - a novel photographic emulsion of Lippmann with silver halides and with a hydrophilic colloidal binder, remarkable in particular by the following characteristics considered separately or in combination - a) - it contains a removable dye. , practically inert from a photographic point of view and which absorbs light of a spectral composition corresponding to that of the light used to expose the emulsion, the concentration of the dye being sufficient to give the layer of this emulsion a density of 'to the monk about 0.15 units per micron of thickness with the light of the chosen composition;

   b) - the proportion by mass of silver halide relative to the hydrophilic colloidal binder is at least about 1.3
 EMI20.1
 a) r the proportion in maeae of silver halide per rprp. : Hydrophilic colloidal content is at least about 2: 1; d) - the hydrophilic colloid is gelatin and the emulsion is
 EMI20.2
 apictrally sensitized; s) - = the haloenide comprises more than 90 mole percent bromide and the halide grains have an average diameter of not more than about
0.1;

   f) - the mass proportion of silver halide relative to gelatin is approximately 3.8 to 1, the silver bromide grains having a diameter of approximately 0.06, and the emulsion containing
 EMI20.3
 approximately 0.06 g of bis (3-methyl-1 -eulfophéryl-r-pyrazole5-one) trimethinoxonol per gram of gelatin

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 2) = a sensitive photographic product, remarkable in particular for the following characteristics considered separately or in combinations a) - it comprises a support and an orohe photographic emulsion of Lippmann as defined under 1); b) - the emulsion layer has a dry thickness of 5 m;

   c) - it does not contain any antihalation oouohe) - the support is paper s) - the support is glass; 3) - a process for preparing images with high resolving power, which consists in exposing a product having a photosensitive emulsion layer and processing it to obtain an image, and which is remarkable in that a product is used. photosensitive as defined by us 2).

 

Claims (1)

<Desc / Clms Page number 1> The undersigned is aware that no document attached to the file of a patent for invention may be of a nature to make either the description or the drawings ;, substantive modifications and declares that the content of this mote does not make such changes and has no other purpose than to report one or more material errors, It recognizes that the content of this note cannot have the effect of making the patent which will be granted on the aforementioned patent application valid in whole or in part. if it was not fully or partially under the legislation currently in force, It authorizes the administration to attach this note to the patent file and to issue a photocopy thereof.