CA2020382A1 - White light handleable negative-acting silver halide photographic elements - Google Patents
White light handleable negative-acting silver halide photographic elementsInfo
- Publication number
- CA2020382A1 CA2020382A1 CA 2020382 CA2020382A CA2020382A1 CA 2020382 A1 CA2020382 A1 CA 2020382A1 CA 2020382 CA2020382 CA 2020382 CA 2020382 A CA2020382 A CA 2020382A CA 2020382 A1 CA2020382 A1 CA 2020382A1
- Authority
- CA
- Canada
- Prior art keywords
- silver halide
- halide photographic
- photographic element
- layer
- group
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/76—Photosensitive materials characterised by the base or auxiliary layers
- G03C1/815—Photosensitive materials characterised by the base or auxiliary layers characterised by means for filtering or absorbing ultraviolet light, e.g. optical bleaching
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
- G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
Abstract
ABSTRACT OF DISCLOSURE
UV-sensitive negative acting silver halide photographic elements are used in contacting processes, and especially dry etch correction processes and can be safely handled under white light. These elements comprise a support base, a negative acting hydrophilic colloidal silver halide emulsion layer comprising photographic silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion support base has on its surface most distant from the layer an antihalation layer comprising a water-removable UV-absorbing compound having significant absorption in the range of from 350 to 400 nm.
UV-sensitive negative acting silver halide photographic elements are used in contacting processes, and especially dry etch correction processes and can be safely handled under white light. These elements comprise a support base, a negative acting hydrophilic colloidal silver halide emulsion layer comprising photographic silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion support base has on its surface most distant from the layer an antihalation layer comprising a water-removable UV-absorbing compound having significant absorption in the range of from 350 to 400 nm.
Description
- 2~2~ J~
WHITE LIGHT HANDLEABLE NEGATIVE-ACTING SILVER
HALIDE_PHOTOGRAPHIC ELEMENTS
FIELD OF THE INVENTION
The present invention relat~s to W sensltive negative acting silver halide photographic elements, and more particularly to W sensitive negative acting silver halide photographic element~ which can be handled under room lighting conditions without significant loss in image density, and which upon development of a half-tone image thereon can be dry etched with improved performance ~haracteristics.
BACRGROUND OF T~E ART
Light sensitive recording materials may suffer from a phenomenon known as halation which causes degradation in the quality of the recorded image. Such degradation may occur when a fraction of the imaging light which strikes the photosensitive layer is not absorb~d but passes through to the film base on which the photosensitive layer is coated. A portion of the light reaching the base may be reflected back to strike the photosensitive layer from the underside. Light thus reflected may, in some cases, contribute significantly to the total exposure of the photosensitive layer. Any particulate matter in the photosensitive element may cause 33 light passing through the element to be scattered.
Scattered light which is reflected from the film base wiIl, on its second passage through the photosensitive layer, cause exposure over an area adjacent to the point of intended exposure. It is this effect which leads to image degradation. Silver halide based photograhic material~ tincluding photothermographic mater~als) are prone to this form of image degradation since the .............. ... . ..... . . . . . . . . .
WHITE LIGHT HANDLEABLE NEGATIVE-ACTING SILVER
HALIDE_PHOTOGRAPHIC ELEMENTS
FIELD OF THE INVENTION
The present invention relat~s to W sensltive negative acting silver halide photographic elements, and more particularly to W sensitive negative acting silver halide photographic element~ which can be handled under room lighting conditions without significant loss in image density, and which upon development of a half-tone image thereon can be dry etched with improved performance ~haracteristics.
BACRGROUND OF T~E ART
Light sensitive recording materials may suffer from a phenomenon known as halation which causes degradation in the quality of the recorded image. Such degradation may occur when a fraction of the imaging light which strikes the photosensitive layer is not absorb~d but passes through to the film base on which the photosensitive layer is coated. A portion of the light reaching the base may be reflected back to strike the photosensitive layer from the underside. Light thus reflected may, in some cases, contribute significantly to the total exposure of the photosensitive layer. Any particulate matter in the photosensitive element may cause 33 light passing through the element to be scattered.
Scattered light which is reflected from the film base wiIl, on its second passage through the photosensitive layer, cause exposure over an area adjacent to the point of intended exposure. It is this effect which leads to image degradation. Silver halide based photograhic material~ tincluding photothermographic mater~als) are prone to this form of image degradation since the .............. ... . ..... . . . . . . . . .
3 ~ 2 photosensitive layers contain light scattering particles.
The e~fect of light scatter on image quality is well documented and is described, for example, in T. H. James "The Theory of the Photographic Process", 4th Edition, Chapter 20, ~acmillan 1977.
It is common practice to minimise the effects of light scatter by including a light absorbing layer within the photographic element. To be effective the absorption of this layer must be at the same wavelengths as the sensitivity of the photosensitive layer. In the case of imaging materials coated on transparent base, a light absorbing layer is ~requently coated on the reverse side of the base from the photosensitive layer. Such a coating, known as an "antihalation layer", effectively prevents reflection of any light which has passed through the photosensitive layer.
I A similar effect may be achieved by a light absorbing layer interposed between the photosensitive layer and the base. This construction, described as an "antihalation underlayer" is applicable to photosensitive coatings on transparent or non-transparent bases. A light absorbing substance may be incorporated into the photosensitive layer itself, in order to absorb scattered light. Substances used for this purpose are known as "acutance dyes". It is also possible to improve image quality by coating a light absorbing layer above the photosensitive layer of a wet procçssed photographic element. Coatings of this kind, described in U.S. Patent Specification No. 4,312,941 prevent multiple reflections of scattered light between the internal surfaces of a photographic element.
When the wavelength of sensitivity of the imaging medium is within the visible regions of the electromagnetic spectrum it is often necessary to have the antihalatlon dye ~endered colorle ~ prior to vie~ing of the ~inal image. If the dye i~ not rendered colorless, the visible antihalation dye will provide a background 7J ~
density or stain to the final image. Antihalation dyes can be rendered colorless by way of heat bleaching, development solution bleaching, a specific bleaching solution, or removal from the medium in a dissolving bath.
When the wavelength of sensitivity of the medium, and hence the wavelength of absorption o~ the antihalation dye, is outside the visible re~ion, it is not nece~sary to decolorize the antihalation dye since it has no color (i.e.~ it is not visible). Some antihalation dyes may have absorption tails that extend into the visible region and would therefore have to be decolorized (e.g., U.S. Patent 4~58~1~3~5)o It is very desirable to produce silver halide photographie elements for duplicating and contacting processes which may be handled safely in bright white light. The benefits of this include ease of working and inspection of the element during exposure and processing, and generally more pleasant working conditions for the operators. Neqative acting silver halide elements can generally be made resistant to fogging in room light by making use of an accentuated low intensity reciprocity failure effect.
In the use of negative acting ultraviolet radiation sensitive photographic silver halide emulsion~
and elements, it is desirable to have the elements room light or white light handlable. Providing these emulsions and elements with ultraviolet radiation sensitivity below 400nm can provide an element with good room light handlability. These elements, primarily useful as black and white image forming elements, can still benefit from and often need backside antihalation layers in order to provide sharp images. Using W absorbing antihalation dyes without any significant tail in the visible region of the electromagnetic spectrum has eliminated the need for decolorizing of the antihalation dye.
It has been discovered by applicants, however, that when half-tone images produced from such W sensitive ~ 3~3~
photographic ~edia are used in dry etch processes, there is an adv~rse affect on the process from the residual antihalation dye. In the dry e~ch process, the photosensitive medium of this invention is repeatedly exposed through the black-and-white half-tone color separation image. These multiple 'exposures increase the dot sizes, minimizing on-press dot gain or correcting color balance or tone. If the W dye is not present in the antihalation layer of ths unexposed UV sensitive film, what is ordinarily observed is that the higher percentage dots expand to fill in the highlights (veiling) before there is sufficient dot gain in the low percentage and intermediate dots. Conversely if the W dye is still present in the imaged medium after processing then lS subsequent exposures to duplicating, proofing or plate materials necessitates hisher exposure to burn through the hiqh W Dmin areas which causes a shift in dot size, leading to inaccurate dot reproduction.
Thus two key requirements are 1) that the W dye be present during the image step of the unimaged material for optimal dry etching, and 2) that the W dye be removed during the chemical process for optimal subsequent contact exposures.
U.S. Reissue Patent No. 30,303 describes W
absorbing dyes useful as filter dyes in photographic elements. The claims are for molecules of the type Rl /CN
N-CH=C~-CH=C
~ R~ \G n wherein n is 1 or 2, when n is 1, R~ and R2 are independently chosen to represent hydrogen, an alkyl group of 1 to 10 carbon atoms, or a cyclic alkyl group of 5 or 6 carbon atoms provided that R1 and R2 cannot both be hydrogen, or R1 and R2 taken together represent the atoms neeessary to complete a cycli~ amino group and when n is 2 at least one of R1 and R2 is alkylene and G represents an e~ectron withdrawing group.
They are incorporated in a photographic element of a suport, silver halide layer(s) and in W filter layer containing above dye. Alternatively, they can be in the film support. The examples given refer to color negative coatings, though black and white constructions are not excluded. No mention is made of water solubilization or bleachability. There use is to protect the film of unwanted W exposure to give a more balanced color rendition.
Similar abilities are described in U.S. Patents 4,307,184 and 4,756,908. The first patent refers to polymeric versions of the dye class and is fairly far removed from our proposed use. The second patent refers to particular versions of Formula I (Rl-R2-allyl for 3, and R short chain alkyl, C1-C3 Rl~opt. subs long chain alkyl >ClO). Advantages are claimed for improved absorption profiles, easier and more consistent dispersions obtainable and show a reduced speed loss compared to the derivatives claimed in Reissue Patent 30~303- Again the main application is for the W filter dye in the color negative constructions. The dyes are hydrophobic in U.S. Patents 4,307,184 and 4,576,908 and presumably would not be bleached in processing. In fact it is usually preferred to be nonbleachable and nondiffusing to give W protection after processing.
In U.S. Patent 4,307,183 the supersensitizing combination of a polymeric version of ~ormula I with a methine spectral sensitizer in silver halide oonstructions is claimed.
O~ more relevance is U.S. Patent Application Serial No. IF/381] where water solubilized versions of I
are claimed in direct positive (black and white) silver halide constructions. A general formula of water solubilization is used which may make it novel compared to the clas~ and uses disclosed in Reissue Patent 39,303.
~he dye has to be reacti~ely associated with the silver halide emulsion and is not dîsclosed specifically as a --6f'~'J $ 2 ~ ~3 ~ r J
backside coating. Advantages are claimed for i~proved white light safety with minimal residual UV stain after processing.
SUMMARY OF THE INVENTION
According to the present'invention, there i~
provided a W sensitive negative acting silver halide photographic element for contacting processes which can be safely handled under white light, said element comprising a support, a hydrophilic colloidal silver halide emul~ion layer comprising negative acting silver halide ~rains, and a backside coated antihalatlon layer, wherein said backside coated antihalation layer comprises a water removable W absorbing compound having at least 80%
lS absorption in the range of 359 to 400 nm.
DETAILED DESCRIPTION OF TEIE INVENTION
The present invention relates to a UV sensitive negative acting silver halide photographic element comprising a support, a hydrophilic colloidal silver halide emulsion layer comprising negative acting UV
sensitive photographic 6ilver halide grains, and at least a backside coated W absorbing antihalation layer, wherein said antihalation layer comprises a water removable UV
ab~orbing compound having at least 80% of absorption in the range of 350 to 400 nm.
Preferably, the W absorbing compounds for use in the silver halide photographic element according to the pre6ent invention correspond to the general formula:
Rl\ CN
- N-CH=CH-CH=C
35 in which Rl and R2, the same or different, each represent~ an alkyl group~ an aryl group or a cyclic alkyl -7- ~ ~ r~J ~
group, or R1 and ~2 taXen together represent the atoms necessary to complete a cyclic amino group, G represents an electron withdrawing group, and at least one of Rl, R2 and ~ is substituted ~ith a water solubilizing group.
In the above general formula (I):
R1 and IR2 can be the same or different and represent alkyl groups, preferably alkyl groups having 1 to 10 carbon atoms, more preferably alkyl groups having 1 to 4 carbon atoms, including substituted alkyl groups such as cyanoalkyl or alkoxyalkyl groups, aryl ~roups, preferably aryl groups having 6 to 20 ~arbon atoms, more preferably aryl groups having 6 to 10 carbon atoms or cyolic aIkyl groups, preferably cyclic alkyl groups having 5 or 6 carbon atoms or R1 and R2 taken together represent the elements necessary to complete a cyclic amino group such as, for example, a piperidino, a morpholino, a pyrrolidino, a hexahydroazepino and a piperazino group, G represents an electron withdrawing group of any electron withdrawing groups known in the art such as, for example, CN, NO2, COOR or SO2R wherein R represents an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, or an aryl group (such as phenyl or naphthyl), preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and at least one of Rl, R2 and G is substituted with a water solubilizing group o any water solubilizing groups known in the art such as, for example, a COOH group or an alkaline metal or ammonium salt thereof, a S03H
group or an alkaline metal or ammonium salt thereof, a hydroxy group, a quaternary ammonium salt containing group, a phosphate group or a polyoxyalkylene group.
-8~ s~.? ;~
More preferably, the W absorbing compounds ~or use in the silver halide photographic elements according to the present invention correspond to the general formula:
Rl\ CN
N-CHYCH-CH=C II
in which:
~ 1 represents an alkyl group having 1 to 10 carbon atoms, preferably a lower alkyl group having 1 ~o 4 carbon atoms such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tert-butyl group, and R3 represents an alkylene group having 1 to 10 carbon atoms whose carbon atom chain may comprise divalent groups such as, for example, -o-, -S-, -COO- or -SO2-.
The W absorbing compounds of the photographic elements according to the present invention have a strong absorption in the region of the electromaynetic spectrum at the ~oundary between the W and the visible region.
The W absorbing compounds acording to this invention : have a peak or plateau in its absorbing spectrum around 380 nm. At least 80% of their absorption is in the range of from 350 to 400 nm, their absorption below 350 nm being such as not to affect significantly the response of the silver halide emulsion to the W radiation of the exposure ~ light, preferably such as not to absorb more than 30% of : 30 the radiation emitted by exposure lamps having a maximum emulsion wavelength of 317nm. Additionally, the W
: : ~ absorbing compound~ of the photographic elements according to the present invention are highly soluble in water, so :that they can be washed out of the element during ~ 35 processingt without a signlficant retention of UV
: ~ absorption. Preferably, the absorption of the element in Dmin areas after processing is, in the range from 300 nm to 400 nm, less than 0.10.
.
_9~ 5 ~ ~
The following are examples of water soluble W
absorbing compound~ which are applicable to the present invention:
N--CE~CH--CEI~C ( 1 ) HO--C--C~12 CN
N-CE~-CH-CH=C ( Z ) CH3 \ CN
N--CH=CH--CH3C ( 3 ) C2H5 \ CN
N-C~=CH-CH2C ( 4) HO3S--CH2-C~2 COOC2H!;
2 5 ~3 ~ CN
N--CH~=CH~CH=C ( 5 ) I
~~ CN
~ SC)3H
C2H5 \ CN
N--CH~CH-C}I~C ( 6 ) ~O~
: 35 O-CHz~ OE~
O
2 ~
--1 0 ~
C2H5\ CN
CH2-CH N-C~=CH-CH-C (7) O + 7~CH2-C~2 CN
S C~12-CH2 CH3 CH3-C6H4-sO 3 11 \ /
O N-CH CH-CH-C (8) HO-C-CH CN
11 z CH3\ N
N-CH=C~-CH~C 19) Na2O3P-o-c~2-cH2 CN
HO3S ~ N
N-CH=CH-CH-C (10) ~0 ~, CN
{H3co-(cH2-c~2o)n-cH2-cM2}2-N-CH-CH~C~-c (11) CN
(wherein n=12-14) ~ .
;The W absorbing compounds of this invention can ::30 be prepared according to methods well known in the art.
: The W absorbing compounds of general formulas (I) and ~II) can be prepared by treating an appropriate amine : compound Gontaining the water solubilizing ~roup with an appropriate intermediate in an organic solvent at boiling temperature followed by u~ual techniques for isolating the ~: .
~ 2 ~ 3 ~3, ~ r,J
compounds. Useful intermediates are for exampl~ described in U.S. Patent 4,045,229.
The following is a preparative example of a W
absorbing compound for use in the present invention.
PREPAR~TIVE E~AMPLE
Compound ( 1 ):
N-(3-allylidenemalononitrile~-sarcosine Sarcosine (89.1 grams, 1 mole) was dissolved in 170 ml of water containing ~aOH (40 ~rams, 1 mole) and 450 ml of methanol. Acetanilidoallylide~emalononiSrile (216 grams, 0.91 moles) was then added with stirring. The mixture was refluxed for 30 minutes and then cooled in ice. The addition of 100 ml of 37% HCl separated a yellow colored solid that was filtered and cry~tallized from a 2:1 ethanol-wa~er mixture. The obtained product (112 grams, yield 65~) had a M.P. = 170-2C and a percent analysi~ for CgHgN30 as follows:
N~C% H%
Calculated 21.9856.544.74 Found 21.66 56.224.72 Spectropho~etric analysis :
~max (in water) = 374nm ~ (in water) - 52,000 The product is soluble in water upon addition of a stoi~hiometric quantity of NaO~.
In the photographic elements ok this invention, the UV absorbing compoun~s are used in an aqueous penetrable binder layer hydrophilic colloidal layer on the back~ide of the base or support layer. Said backside layer is further frDm the exposure light source than the silver halide emulsion layer and on the oppo~ite side of the base ~rom the silver halide emulsion layer. In order to incorporate the UV absorbing compounds into an -12- ~J'~ )J
hydrophilic colloidal layer of the silver halide photographic elements according to this invention, they may be added in the ~orm of a water solution to the hydrophilic colloidal coating composition. The amount of the W absorbing eompounds used, although difPerent according to the type of the compo~nd or of ~llver halide emulsion to be used, is generally about 0.02g/m2 or greater (preferably no more than 0.3g/m2). The antihalation dye ~hould provide an absorbance between 350 and 400 nm (e.g., 375 nm) of at least 0.3, preferably at least 0.5, and more preferably at least 0.8.
It is well known in the art that silver halides have a high natural sensitivity to UV radlations and that silver bromide also has a relatively high sensitivity to blue and shorter wavelength visible light, while ~ilver chloride has a relatively low sensitivity to blue and to shorter wavelength visible light. Therefore, silver halide emulsions for use in the photographic elements according to this invention are preferably higher chloride silver halide emulsions. They preferably contain at least 50%
mole and more pre~erably at least 75% mole of silver chloride. The higher the silver chloride content, the lower is the natural blue and visible light sensitivity, even if the UV radiation sensitivity remains high. More preferably, the silver halide emulsions to be used in type photographic elements according to the present invention are emulsions wherein at least 75% by weight of all silver halide grains are silver halide grains wherein at least at 80% mole is silver chloride. The remaining siIver halide, if any, will be silver bromide and/or silver iodide but the latter should normally be present in an amol~nt not exceeding 10% mole. In case of silver halides comprising chloride in the range of fr~m 50 to 75%
mole, the remaining halide being essentially bromide, the 3$ speotral sensitivity is even more extended to visible region and lt may be useful to comblne the W absorblng compounds according to this invention with dyes ~apable of 2 ~
absorbing visible radiations so that the photographic element can be safely handled in bright light conditions.
The dyec include, for example, oxonol dyes, benzylidene dyes, and the like, which can be bleachable or washable during processing. Examples of useful dyes are described, for example, in U.S. patent 4,140,~31. In conventional emulsions sensitizing dyes are used to extend the sensitivity of the emulsion to longer wavelengths of visible light. This is not required with the emulsions used in the present invention. It also appears to be desirable for the high chloride silver halide emulsions to have a relatively small grain size, e.g. a mean grain size of from 0.05 to 0.6 micron, the preferred grain size being in the range of from 0.05 to 0.3 microns and the most lS preferred being from O.OS to 0.1 micron. The high chloride silver halide grains preferably have a cubic shape, but may have other shapes, such as octahedra, sphere~, tabular shapes, etc.
In the present invention, silver halides are preferably prepared in ~he presence of at least a doping metallic element of the 8th Group of the Periodic Table of Elements, such as rhodium, iridium and ruthenium, which acts as electron acceptor. Said doping element is preferably chosen among water-soluble iridium salts, water soluble ruthenium salts, or water-soluble rhodium salts. Iridium salts include iridium and alkaline metal halides, such as potassium iridium (III) hexachloride and sodium iridium (III) hexabromide. Rhodium salts include rhodium halides, such as rhodium (III) trichloride and rhodium (IV) tetrachloride and rhodium and alkaline metal halides such as potassium rhodium ~III) hexabromide and sodium rhodium (III) hexachloride. These salts may be added in a quantity of from 0.5x10-4 to lOx10-4 moles, and preferably from 2x10-4 to 7x10-4 moles per mole of silver halide.
Gold compounds, used for chemical sensiti~ation, inslude alkali metal chloroaurates, chloroauric acid, gold sulfide, gold selenide, and the like. Said gold compounds -14~ J ~ ''J ''~ ~
are generally used in a quantity of from lxlO-6 to lx10-4 moles per mole of silver halide.
The W sensitive silver halide emulsions of the photoqraphic elements according to this invention may contain various other photographic additives wich include sensitizers, desensitizers, solarization accelerators, stabilizers, hardeners, coating aids, preservatives, matting agents, antistatic agents, and the like, as de~cribed, for e~ample, in U.S. Patent 4,495,274.
Gelatin is generally used as hydrophilic colloid for the silver halide photographic elements of the pre~ent invention. As hydrophilic colloids, gelatin derivatives, natural substances such as albumin, casein, agar-agar, alginic acid and the like, and hydrophilic poly~ers such as polyvinyl alcohol, polyvinylpyrolidone, cellulose ethers, partially hydrolized polyvinyl acetate, and the like can be used in addition to or instead of gelatin.
Further, gelatin can be partially substituted with polymer latexes obtained by emulsion polymerization of vinyl monomers, such as polyethylacrylate latexes, to improve ~he physical characteristics of the photographic layers.
Support bases used in the negative-acting silver halide photographic elements according to this invention can be any of the conventionally used support bases, such as glass, cloth, metal, film including for example cellulose acetate, cellulose acetate-butyrate, cellulose nitrate, polyester, polyamine, polystyrene, and the like, paper including baryta-coated paper, resin-coated paper, and the like.
The silver halide photographic elements according to this invention may be used in the field of Graphic Arts for various purposes, such as, for example, ~or contacting, for reproduction, for making offset printing masters~ as well as in radiography for special purposes, in electron photo~raphy, and the like, where high W sensitivity is required together with low blue light sensitivity.
... ..
-15- ~?~ ~ r3 ~ o ?) The silver halide photographic elements according to this invention are highly W sensitive and give high contrast and low minimum density (fog) when they are exposed with light rich in W rays, and they can be handled in bright white room light~
These and other advantages according to the present invention will be lllustrated with reference to the following examples.
A silver halide emulsion containing 84 mole %
chloride and 16 mole % bromide was prepared by adding simultaneously and under stirring, over a period of 25 minutes, with a double-jet technique, water solution B and water solution C to water gelatin solution A, said water solutions having the composition reported herein below.
Solution A
~ater - g 833.3 Gelatin - ~ 25 Polyvinylpyrrolidone (K-30) - 6.33 KBr - ml 0.167 (lN~
Solution B
Water - g 368 AgNO3 - 9 170 Solution C
. .
Water - g 361.3 KCl - g 62.65 (0.84 moles) KBr - g 19.04 (0.16 moles) Na3RhCl6.12H2O - g 0.200 The gelatin solution was kept at constant temperature of 30~C. The addition rate of solution ~ was constant, while the addition rate of solution C varied such as to maintain the millivolt of the emulsion thus formed at a value of ~,J ~ 1,; 3~3~ 3, 120 + 2 mv measured with a specific electrode for Br ion and a reference electrode of the saturated Ag/AgCl type.
The emulsion, wherein the sol~ble salts had been removed with the conventional coagulation method, had a mean grain diameter of O.O9~m. The emulsion was then chemieally ~ensitized with sodium thiosulfate`and sodium gold chloride. At the end of the chemical sensitization a triazole stabilizer was added and the emulsion was prepared for coa~ing with the addition of additional gelatin, coatin~ surface active agents and formaldehyde hardener.
The emulsion was then coated at a silver coating weight of 2.7g Ag/m2 onto a polyethylene terephthalate support base which was backed with green antihalation layers that had varying amounts of yellow, blue and UV dye as shown as explained in Table l and Figures 1 and 2.
The resulting films were exposed through a 0-2, 20 cm continuus wed~e. The exposing lamp was a violux 1500S W lamp at a distance of 52 inches from the film plane.
The exposed films were developed in 3M RDC
developer for 20 sec at 40C and fixed in 3M fix roll ixer.
Dmin, Dmax, Speed at .2, Toe Contrast, and Average Contrast of the resulting coatings show that the E-E sensitivity are essentially the ~ame.
Next the dry etching characteristics were examined which demonstrates the resulting improvement by incorporating the W dye into the antihalation formulation.
In order to evaluate the dry etching characteristics it is first necessary to determine the optimum dot-for-dot exposure in the E-E mode.
For these tests a hard dot original was usedO
The optimum contact exposure which we will define as producing a Dmax >4.0 with a dot reprodu~tion within 1% at the midtone turned out to be 18 units.
.... , .. ~ .. , . , .. , .. , .. , ., ....... _.... ......... ......... .
-17- 2~2~
The dry etch test then consists of making contact exposures to the original of lx, 2x, 4x, 6x, 8x, lOx, 12x, 14x and 16x the dot-for-dot exposure. The resulting dot enlargement is measured. Both the highlight, shadow and midtone are of importance with the objective being to obtain a very cbntrolled movement of all dot sizes and as large a movement as possible in the midtone and shadow before the highlights veil in.
o Antihalation Characteristlcs of the Various Coatinqc Coatin~ Absorbance *y *W
1 .83 .34 .18 2 .80 .34 .38 3 .80 .33 .S0 4 .80 .48 0.24 .82 .49 .69 *B is oxonol blue 628 which has an absorbance peak 20 at 650nm *Y is oxonol yellow K which has an absorbance peak at 430nm * W is the water soluble W dye number 1 of this invention which has an absorbance peak at 370nm .
'~ ~ 2 ~ S ~
Sensitometr~ _f the Various Coatings Toe ~verage Ctg. No. Dmin Dmax S.2 Contrast Contrast .
5 1 .04 4.5 -2.8~; 2.0g 9.8 2 .04 4.5 -2.87 ' 2.14 9.8 3 .04 4.5 -~.87 2.20 9.6 .04 4.5 -2.86 2.17 9.~
.04 4.5 -2.88 2.17 g.2 TA~LE 3 Dry Etch Results Table 3 shows how dramatically the addition of the W dye to the antihalation backing affects the resulting dry etch1ng characteristics. It holds back veiling in the highlights allowing greatcr movement in the midtone and shadow ends.
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~ C o ~ ~ o ~ ~
O U~ ~ U7 U~
\O ~_, O _I ~ ':P Ul r-_I cn o~ ~ cr ~n o~o O _l _~ (~ cn C7 _~
,~ o : ~ Lt'~ IS~
~ o~o o .~ u~ a~
~ 8~
~ ~
t: V ~ V ~: ' ) ~ ~ :~ V _I
.,", tn C v v.
~ ~ ~ O O
O E~ tl; ~
~ ,.
: ~ .
~ ~ X
X ~ ~ P~ o ~ <~r .... . .... . .
The e~fect of light scatter on image quality is well documented and is described, for example, in T. H. James "The Theory of the Photographic Process", 4th Edition, Chapter 20, ~acmillan 1977.
It is common practice to minimise the effects of light scatter by including a light absorbing layer within the photographic element. To be effective the absorption of this layer must be at the same wavelengths as the sensitivity of the photosensitive layer. In the case of imaging materials coated on transparent base, a light absorbing layer is ~requently coated on the reverse side of the base from the photosensitive layer. Such a coating, known as an "antihalation layer", effectively prevents reflection of any light which has passed through the photosensitive layer.
I A similar effect may be achieved by a light absorbing layer interposed between the photosensitive layer and the base. This construction, described as an "antihalation underlayer" is applicable to photosensitive coatings on transparent or non-transparent bases. A light absorbing substance may be incorporated into the photosensitive layer itself, in order to absorb scattered light. Substances used for this purpose are known as "acutance dyes". It is also possible to improve image quality by coating a light absorbing layer above the photosensitive layer of a wet procçssed photographic element. Coatings of this kind, described in U.S. Patent Specification No. 4,312,941 prevent multiple reflections of scattered light between the internal surfaces of a photographic element.
When the wavelength of sensitivity of the imaging medium is within the visible regions of the electromagnetic spectrum it is often necessary to have the antihalatlon dye ~endered colorle ~ prior to vie~ing of the ~inal image. If the dye i~ not rendered colorless, the visible antihalation dye will provide a background 7J ~
density or stain to the final image. Antihalation dyes can be rendered colorless by way of heat bleaching, development solution bleaching, a specific bleaching solution, or removal from the medium in a dissolving bath.
When the wavelength of sensitivity of the medium, and hence the wavelength of absorption o~ the antihalation dye, is outside the visible re~ion, it is not nece~sary to decolorize the antihalation dye since it has no color (i.e.~ it is not visible). Some antihalation dyes may have absorption tails that extend into the visible region and would therefore have to be decolorized (e.g., U.S. Patent 4~58~1~3~5)o It is very desirable to produce silver halide photographie elements for duplicating and contacting processes which may be handled safely in bright white light. The benefits of this include ease of working and inspection of the element during exposure and processing, and generally more pleasant working conditions for the operators. Neqative acting silver halide elements can generally be made resistant to fogging in room light by making use of an accentuated low intensity reciprocity failure effect.
In the use of negative acting ultraviolet radiation sensitive photographic silver halide emulsion~
and elements, it is desirable to have the elements room light or white light handlable. Providing these emulsions and elements with ultraviolet radiation sensitivity below 400nm can provide an element with good room light handlability. These elements, primarily useful as black and white image forming elements, can still benefit from and often need backside antihalation layers in order to provide sharp images. Using W absorbing antihalation dyes without any significant tail in the visible region of the electromagnetic spectrum has eliminated the need for decolorizing of the antihalation dye.
It has been discovered by applicants, however, that when half-tone images produced from such W sensitive ~ 3~3~
photographic ~edia are used in dry etch processes, there is an adv~rse affect on the process from the residual antihalation dye. In the dry e~ch process, the photosensitive medium of this invention is repeatedly exposed through the black-and-white half-tone color separation image. These multiple 'exposures increase the dot sizes, minimizing on-press dot gain or correcting color balance or tone. If the W dye is not present in the antihalation layer of ths unexposed UV sensitive film, what is ordinarily observed is that the higher percentage dots expand to fill in the highlights (veiling) before there is sufficient dot gain in the low percentage and intermediate dots. Conversely if the W dye is still present in the imaged medium after processing then lS subsequent exposures to duplicating, proofing or plate materials necessitates hisher exposure to burn through the hiqh W Dmin areas which causes a shift in dot size, leading to inaccurate dot reproduction.
Thus two key requirements are 1) that the W dye be present during the image step of the unimaged material for optimal dry etching, and 2) that the W dye be removed during the chemical process for optimal subsequent contact exposures.
U.S. Reissue Patent No. 30,303 describes W
absorbing dyes useful as filter dyes in photographic elements. The claims are for molecules of the type Rl /CN
N-CH=C~-CH=C
~ R~ \G n wherein n is 1 or 2, when n is 1, R~ and R2 are independently chosen to represent hydrogen, an alkyl group of 1 to 10 carbon atoms, or a cyclic alkyl group of 5 or 6 carbon atoms provided that R1 and R2 cannot both be hydrogen, or R1 and R2 taken together represent the atoms neeessary to complete a cycli~ amino group and when n is 2 at least one of R1 and R2 is alkylene and G represents an e~ectron withdrawing group.
They are incorporated in a photographic element of a suport, silver halide layer(s) and in W filter layer containing above dye. Alternatively, they can be in the film support. The examples given refer to color negative coatings, though black and white constructions are not excluded. No mention is made of water solubilization or bleachability. There use is to protect the film of unwanted W exposure to give a more balanced color rendition.
Similar abilities are described in U.S. Patents 4,307,184 and 4,756,908. The first patent refers to polymeric versions of the dye class and is fairly far removed from our proposed use. The second patent refers to particular versions of Formula I (Rl-R2-allyl for 3, and R short chain alkyl, C1-C3 Rl~opt. subs long chain alkyl >ClO). Advantages are claimed for improved absorption profiles, easier and more consistent dispersions obtainable and show a reduced speed loss compared to the derivatives claimed in Reissue Patent 30~303- Again the main application is for the W filter dye in the color negative constructions. The dyes are hydrophobic in U.S. Patents 4,307,184 and 4,576,908 and presumably would not be bleached in processing. In fact it is usually preferred to be nonbleachable and nondiffusing to give W protection after processing.
In U.S. Patent 4,307,183 the supersensitizing combination of a polymeric version of ~ormula I with a methine spectral sensitizer in silver halide oonstructions is claimed.
O~ more relevance is U.S. Patent Application Serial No. IF/381] where water solubilized versions of I
are claimed in direct positive (black and white) silver halide constructions. A general formula of water solubilization is used which may make it novel compared to the clas~ and uses disclosed in Reissue Patent 39,303.
~he dye has to be reacti~ely associated with the silver halide emulsion and is not dîsclosed specifically as a --6f'~'J $ 2 ~ ~3 ~ r J
backside coating. Advantages are claimed for i~proved white light safety with minimal residual UV stain after processing.
SUMMARY OF THE INVENTION
According to the present'invention, there i~
provided a W sensitive negative acting silver halide photographic element for contacting processes which can be safely handled under white light, said element comprising a support, a hydrophilic colloidal silver halide emul~ion layer comprising negative acting silver halide ~rains, and a backside coated antihalatlon layer, wherein said backside coated antihalation layer comprises a water removable W absorbing compound having at least 80%
lS absorption in the range of 359 to 400 nm.
DETAILED DESCRIPTION OF TEIE INVENTION
The present invention relates to a UV sensitive negative acting silver halide photographic element comprising a support, a hydrophilic colloidal silver halide emulsion layer comprising negative acting UV
sensitive photographic 6ilver halide grains, and at least a backside coated W absorbing antihalation layer, wherein said antihalation layer comprises a water removable UV
ab~orbing compound having at least 80% of absorption in the range of 350 to 400 nm.
Preferably, the W absorbing compounds for use in the silver halide photographic element according to the pre6ent invention correspond to the general formula:
Rl\ CN
- N-CH=CH-CH=C
35 in which Rl and R2, the same or different, each represent~ an alkyl group~ an aryl group or a cyclic alkyl -7- ~ ~ r~J ~
group, or R1 and ~2 taXen together represent the atoms necessary to complete a cyclic amino group, G represents an electron withdrawing group, and at least one of Rl, R2 and ~ is substituted ~ith a water solubilizing group.
In the above general formula (I):
R1 and IR2 can be the same or different and represent alkyl groups, preferably alkyl groups having 1 to 10 carbon atoms, more preferably alkyl groups having 1 to 4 carbon atoms, including substituted alkyl groups such as cyanoalkyl or alkoxyalkyl groups, aryl ~roups, preferably aryl groups having 6 to 20 ~arbon atoms, more preferably aryl groups having 6 to 10 carbon atoms or cyolic aIkyl groups, preferably cyclic alkyl groups having 5 or 6 carbon atoms or R1 and R2 taken together represent the elements necessary to complete a cyclic amino group such as, for example, a piperidino, a morpholino, a pyrrolidino, a hexahydroazepino and a piperazino group, G represents an electron withdrawing group of any electron withdrawing groups known in the art such as, for example, CN, NO2, COOR or SO2R wherein R represents an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, or an aryl group (such as phenyl or naphthyl), preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and at least one of Rl, R2 and G is substituted with a water solubilizing group o any water solubilizing groups known in the art such as, for example, a COOH group or an alkaline metal or ammonium salt thereof, a S03H
group or an alkaline metal or ammonium salt thereof, a hydroxy group, a quaternary ammonium salt containing group, a phosphate group or a polyoxyalkylene group.
-8~ s~.? ;~
More preferably, the W absorbing compounds ~or use in the silver halide photographic elements according to the present invention correspond to the general formula:
Rl\ CN
N-CHYCH-CH=C II
in which:
~ 1 represents an alkyl group having 1 to 10 carbon atoms, preferably a lower alkyl group having 1 ~o 4 carbon atoms such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tert-butyl group, and R3 represents an alkylene group having 1 to 10 carbon atoms whose carbon atom chain may comprise divalent groups such as, for example, -o-, -S-, -COO- or -SO2-.
The W absorbing compounds of the photographic elements according to the present invention have a strong absorption in the region of the electromaynetic spectrum at the ~oundary between the W and the visible region.
The W absorbing compounds acording to this invention : have a peak or plateau in its absorbing spectrum around 380 nm. At least 80% of their absorption is in the range of from 350 to 400 nm, their absorption below 350 nm being such as not to affect significantly the response of the silver halide emulsion to the W radiation of the exposure ~ light, preferably such as not to absorb more than 30% of : 30 the radiation emitted by exposure lamps having a maximum emulsion wavelength of 317nm. Additionally, the W
: : ~ absorbing compound~ of the photographic elements according to the present invention are highly soluble in water, so :that they can be washed out of the element during ~ 35 processingt without a signlficant retention of UV
: ~ absorption. Preferably, the absorption of the element in Dmin areas after processing is, in the range from 300 nm to 400 nm, less than 0.10.
.
_9~ 5 ~ ~
The following are examples of water soluble W
absorbing compound~ which are applicable to the present invention:
N--CE~CH--CEI~C ( 1 ) HO--C--C~12 CN
N-CE~-CH-CH=C ( Z ) CH3 \ CN
N--CH=CH--CH3C ( 3 ) C2H5 \ CN
N-C~=CH-CH2C ( 4) HO3S--CH2-C~2 COOC2H!;
2 5 ~3 ~ CN
N--CH~=CH~CH=C ( 5 ) I
~~ CN
~ SC)3H
C2H5 \ CN
N--CH~CH-C}I~C ( 6 ) ~O~
: 35 O-CHz~ OE~
O
2 ~
--1 0 ~
C2H5\ CN
CH2-CH N-C~=CH-CH-C (7) O + 7~CH2-C~2 CN
S C~12-CH2 CH3 CH3-C6H4-sO 3 11 \ /
O N-CH CH-CH-C (8) HO-C-CH CN
11 z CH3\ N
N-CH=C~-CH~C 19) Na2O3P-o-c~2-cH2 CN
HO3S ~ N
N-CH=CH-CH-C (10) ~0 ~, CN
{H3co-(cH2-c~2o)n-cH2-cM2}2-N-CH-CH~C~-c (11) CN
(wherein n=12-14) ~ .
;The W absorbing compounds of this invention can ::30 be prepared according to methods well known in the art.
: The W absorbing compounds of general formulas (I) and ~II) can be prepared by treating an appropriate amine : compound Gontaining the water solubilizing ~roup with an appropriate intermediate in an organic solvent at boiling temperature followed by u~ual techniques for isolating the ~: .
~ 2 ~ 3 ~3, ~ r,J
compounds. Useful intermediates are for exampl~ described in U.S. Patent 4,045,229.
The following is a preparative example of a W
absorbing compound for use in the present invention.
PREPAR~TIVE E~AMPLE
Compound ( 1 ):
N-(3-allylidenemalononitrile~-sarcosine Sarcosine (89.1 grams, 1 mole) was dissolved in 170 ml of water containing ~aOH (40 ~rams, 1 mole) and 450 ml of methanol. Acetanilidoallylide~emalononiSrile (216 grams, 0.91 moles) was then added with stirring. The mixture was refluxed for 30 minutes and then cooled in ice. The addition of 100 ml of 37% HCl separated a yellow colored solid that was filtered and cry~tallized from a 2:1 ethanol-wa~er mixture. The obtained product (112 grams, yield 65~) had a M.P. = 170-2C and a percent analysi~ for CgHgN30 as follows:
N~C% H%
Calculated 21.9856.544.74 Found 21.66 56.224.72 Spectropho~etric analysis :
~max (in water) = 374nm ~ (in water) - 52,000 The product is soluble in water upon addition of a stoi~hiometric quantity of NaO~.
In the photographic elements ok this invention, the UV absorbing compoun~s are used in an aqueous penetrable binder layer hydrophilic colloidal layer on the back~ide of the base or support layer. Said backside layer is further frDm the exposure light source than the silver halide emulsion layer and on the oppo~ite side of the base ~rom the silver halide emulsion layer. In order to incorporate the UV absorbing compounds into an -12- ~J'~ )J
hydrophilic colloidal layer of the silver halide photographic elements according to this invention, they may be added in the ~orm of a water solution to the hydrophilic colloidal coating composition. The amount of the W absorbing eompounds used, although difPerent according to the type of the compo~nd or of ~llver halide emulsion to be used, is generally about 0.02g/m2 or greater (preferably no more than 0.3g/m2). The antihalation dye ~hould provide an absorbance between 350 and 400 nm (e.g., 375 nm) of at least 0.3, preferably at least 0.5, and more preferably at least 0.8.
It is well known in the art that silver halides have a high natural sensitivity to UV radlations and that silver bromide also has a relatively high sensitivity to blue and shorter wavelength visible light, while ~ilver chloride has a relatively low sensitivity to blue and to shorter wavelength visible light. Therefore, silver halide emulsions for use in the photographic elements according to this invention are preferably higher chloride silver halide emulsions. They preferably contain at least 50%
mole and more pre~erably at least 75% mole of silver chloride. The higher the silver chloride content, the lower is the natural blue and visible light sensitivity, even if the UV radiation sensitivity remains high. More preferably, the silver halide emulsions to be used in type photographic elements according to the present invention are emulsions wherein at least 75% by weight of all silver halide grains are silver halide grains wherein at least at 80% mole is silver chloride. The remaining siIver halide, if any, will be silver bromide and/or silver iodide but the latter should normally be present in an amol~nt not exceeding 10% mole. In case of silver halides comprising chloride in the range of fr~m 50 to 75%
mole, the remaining halide being essentially bromide, the 3$ speotral sensitivity is even more extended to visible region and lt may be useful to comblne the W absorblng compounds according to this invention with dyes ~apable of 2 ~
absorbing visible radiations so that the photographic element can be safely handled in bright light conditions.
The dyec include, for example, oxonol dyes, benzylidene dyes, and the like, which can be bleachable or washable during processing. Examples of useful dyes are described, for example, in U.S. patent 4,140,~31. In conventional emulsions sensitizing dyes are used to extend the sensitivity of the emulsion to longer wavelengths of visible light. This is not required with the emulsions used in the present invention. It also appears to be desirable for the high chloride silver halide emulsions to have a relatively small grain size, e.g. a mean grain size of from 0.05 to 0.6 micron, the preferred grain size being in the range of from 0.05 to 0.3 microns and the most lS preferred being from O.OS to 0.1 micron. The high chloride silver halide grains preferably have a cubic shape, but may have other shapes, such as octahedra, sphere~, tabular shapes, etc.
In the present invention, silver halides are preferably prepared in ~he presence of at least a doping metallic element of the 8th Group of the Periodic Table of Elements, such as rhodium, iridium and ruthenium, which acts as electron acceptor. Said doping element is preferably chosen among water-soluble iridium salts, water soluble ruthenium salts, or water-soluble rhodium salts. Iridium salts include iridium and alkaline metal halides, such as potassium iridium (III) hexachloride and sodium iridium (III) hexabromide. Rhodium salts include rhodium halides, such as rhodium (III) trichloride and rhodium (IV) tetrachloride and rhodium and alkaline metal halides such as potassium rhodium ~III) hexabromide and sodium rhodium (III) hexachloride. These salts may be added in a quantity of from 0.5x10-4 to lOx10-4 moles, and preferably from 2x10-4 to 7x10-4 moles per mole of silver halide.
Gold compounds, used for chemical sensiti~ation, inslude alkali metal chloroaurates, chloroauric acid, gold sulfide, gold selenide, and the like. Said gold compounds -14~ J ~ ''J ''~ ~
are generally used in a quantity of from lxlO-6 to lx10-4 moles per mole of silver halide.
The W sensitive silver halide emulsions of the photoqraphic elements according to this invention may contain various other photographic additives wich include sensitizers, desensitizers, solarization accelerators, stabilizers, hardeners, coating aids, preservatives, matting agents, antistatic agents, and the like, as de~cribed, for e~ample, in U.S. Patent 4,495,274.
Gelatin is generally used as hydrophilic colloid for the silver halide photographic elements of the pre~ent invention. As hydrophilic colloids, gelatin derivatives, natural substances such as albumin, casein, agar-agar, alginic acid and the like, and hydrophilic poly~ers such as polyvinyl alcohol, polyvinylpyrolidone, cellulose ethers, partially hydrolized polyvinyl acetate, and the like can be used in addition to or instead of gelatin.
Further, gelatin can be partially substituted with polymer latexes obtained by emulsion polymerization of vinyl monomers, such as polyethylacrylate latexes, to improve ~he physical characteristics of the photographic layers.
Support bases used in the negative-acting silver halide photographic elements according to this invention can be any of the conventionally used support bases, such as glass, cloth, metal, film including for example cellulose acetate, cellulose acetate-butyrate, cellulose nitrate, polyester, polyamine, polystyrene, and the like, paper including baryta-coated paper, resin-coated paper, and the like.
The silver halide photographic elements according to this invention may be used in the field of Graphic Arts for various purposes, such as, for example, ~or contacting, for reproduction, for making offset printing masters~ as well as in radiography for special purposes, in electron photo~raphy, and the like, where high W sensitivity is required together with low blue light sensitivity.
... ..
-15- ~?~ ~ r3 ~ o ?) The silver halide photographic elements according to this invention are highly W sensitive and give high contrast and low minimum density (fog) when they are exposed with light rich in W rays, and they can be handled in bright white room light~
These and other advantages according to the present invention will be lllustrated with reference to the following examples.
A silver halide emulsion containing 84 mole %
chloride and 16 mole % bromide was prepared by adding simultaneously and under stirring, over a period of 25 minutes, with a double-jet technique, water solution B and water solution C to water gelatin solution A, said water solutions having the composition reported herein below.
Solution A
~ater - g 833.3 Gelatin - ~ 25 Polyvinylpyrrolidone (K-30) - 6.33 KBr - ml 0.167 (lN~
Solution B
Water - g 368 AgNO3 - 9 170 Solution C
. .
Water - g 361.3 KCl - g 62.65 (0.84 moles) KBr - g 19.04 (0.16 moles) Na3RhCl6.12H2O - g 0.200 The gelatin solution was kept at constant temperature of 30~C. The addition rate of solution ~ was constant, while the addition rate of solution C varied such as to maintain the millivolt of the emulsion thus formed at a value of ~,J ~ 1,; 3~3~ 3, 120 + 2 mv measured with a specific electrode for Br ion and a reference electrode of the saturated Ag/AgCl type.
The emulsion, wherein the sol~ble salts had been removed with the conventional coagulation method, had a mean grain diameter of O.O9~m. The emulsion was then chemieally ~ensitized with sodium thiosulfate`and sodium gold chloride. At the end of the chemical sensitization a triazole stabilizer was added and the emulsion was prepared for coa~ing with the addition of additional gelatin, coatin~ surface active agents and formaldehyde hardener.
The emulsion was then coated at a silver coating weight of 2.7g Ag/m2 onto a polyethylene terephthalate support base which was backed with green antihalation layers that had varying amounts of yellow, blue and UV dye as shown as explained in Table l and Figures 1 and 2.
The resulting films were exposed through a 0-2, 20 cm continuus wed~e. The exposing lamp was a violux 1500S W lamp at a distance of 52 inches from the film plane.
The exposed films were developed in 3M RDC
developer for 20 sec at 40C and fixed in 3M fix roll ixer.
Dmin, Dmax, Speed at .2, Toe Contrast, and Average Contrast of the resulting coatings show that the E-E sensitivity are essentially the ~ame.
Next the dry etching characteristics were examined which demonstrates the resulting improvement by incorporating the W dye into the antihalation formulation.
In order to evaluate the dry etching characteristics it is first necessary to determine the optimum dot-for-dot exposure in the E-E mode.
For these tests a hard dot original was usedO
The optimum contact exposure which we will define as producing a Dmax >4.0 with a dot reprodu~tion within 1% at the midtone turned out to be 18 units.
.... , .. ~ .. , . , .. , .. , .. , ., ....... _.... ......... ......... .
-17- 2~2~
The dry etch test then consists of making contact exposures to the original of lx, 2x, 4x, 6x, 8x, lOx, 12x, 14x and 16x the dot-for-dot exposure. The resulting dot enlargement is measured. Both the highlight, shadow and midtone are of importance with the objective being to obtain a very cbntrolled movement of all dot sizes and as large a movement as possible in the midtone and shadow before the highlights veil in.
o Antihalation Characteristlcs of the Various Coatinqc Coatin~ Absorbance *y *W
1 .83 .34 .18 2 .80 .34 .38 3 .80 .33 .S0 4 .80 .48 0.24 .82 .49 .69 *B is oxonol blue 628 which has an absorbance peak 20 at 650nm *Y is oxonol yellow K which has an absorbance peak at 430nm * W is the water soluble W dye number 1 of this invention which has an absorbance peak at 370nm .
'~ ~ 2 ~ S ~
Sensitometr~ _f the Various Coatings Toe ~verage Ctg. No. Dmin Dmax S.2 Contrast Contrast .
5 1 .04 4.5 -2.8~; 2.0g 9.8 2 .04 4.5 -2.87 ' 2.14 9.8 3 .04 4.5 -~.87 2.20 9.6 .04 4.5 -2.86 2.17 9.~
.04 4.5 -2.88 2.17 g.2 TA~LE 3 Dry Etch Results Table 3 shows how dramatically the addition of the W dye to the antihalation backing affects the resulting dry etch1ng characteristics. It holds back veiling in the highlights allowing greatcr movement in the midtone and shadow ends.
.
-19~ 3 ~ ~
o~o ~ o ~ ~ ~ ~ ~ ~ ~r U7 oo~ ,, , ~ ~ ~ ~ , , .,, o ~ ~ ~ U~
u~ ~ ~ u~
o t, ~;~o ~
o ~ ~ ~ ~ U~ ~o ~ ~ 0 o~ cl ~ cn ~ v~ cr ~ o~
o\o o ~r ~ o~
~ o~o .~ o ~ ~ ~ o J~ ~n Lr o ~, o~o o ~ ~ ~ ~ o~
a~
o~
,, o ,, ~ 8 a~
.
J~
~r~ O ~ ~ ~ ~ a~
J V In ~ U~
--IC ) o~ H ~I t`~ G
a~ _l o~
P;
~:1 o~ O ~
~ ~1 ~ a- c: o~ C
~ C o ~ ~ o ~ ~
O U~ ~ U7 U~
\O ~_, O _I ~ ':P Ul r-_I cn o~ ~ cr ~n o~o O _l _~ (~ cn C7 _~
,~ o : ~ Lt'~ IS~
~ o~o o .~ u~ a~
~ 8~
~ ~
t: V ~ V ~: ' ) ~ ~ :~ V _I
.,", tn C v v.
~ ~ ~ O O
O E~ tl; ~
~ ,.
: ~ .
~ ~ X
X ~ ~ P~ o ~ <~r .... . .... . .
Claims (8)
1. A UV sensitive silver halide photographic element comprising a support, a hydrophilic colloidal silver halide emulsion layer comprising UV sensitive negative acting silver halide grains, and a backside coated antihalation layer, said antihalation layer comprising a water removable UV absorbing compound having at least 80% radiation absorption in the wavelength range of 350 to 400 nm.
2. The silver halide photographic element of claim 1, wherein said UV absorbing compound is represented by the general formula:
(I) in which:
R1 and R2, the same or different, each represents an alkyl group, an aryl group or a cyclic alkyl group, or R1 and R2 taken together represent the atoms necessary to complete a cyclic amino group, G represents an electron withdrawing group, and at least one of R1, R2 and G is substituted with a water solubilizing group.
(I) in which:
R1 and R2, the same or different, each represents an alkyl group, an aryl group or a cyclic alkyl group, or R1 and R2 taken together represent the atoms necessary to complete a cyclic amino group, G represents an electron withdrawing group, and at least one of R1, R2 and G is substituted with a water solubilizing group.
3. The silver halide photographic element of claim 1, wherein said UV absorbing compound is represented by the general formula:
(II) in which:
R1 represents an alkyl group, and R3 represents an alkylene group.
(II) in which:
R1 represents an alkyl group, and R3 represents an alkylene group.
4. The silver halide photographic element of claim 1, wherein the added quantity of said water removable UV absorbing compound is in the range greater than 0.02 g/m2 such that the absorbance in the coated element is greater than 0.3.
5. The silver halide photographic element of claim 1, wherein said water removable UV absorbing compound is comprised in a backside gelatin antihalation layer.
6. The silver halide photographic element of claim 1, wherein said UV absorbing compound is comprised in a hydrophilic colloid layer.
7. The silver halide photographic element of claim 1, wherein said silver halide emulsion is a high chloride silver halide emulsion.
8. The silver halide photographic element of claim 1, wherein said silver halide grains have been prepared in the presence of a water soluble iridium salt or a water soluble rhodium salt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US386,631 | 1982-06-09 | ||
| US38663189A | 1989-07-31 | 1989-07-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2020382A1 true CA2020382A1 (en) | 1991-02-01 |
Family
ID=23526402
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2020382 Abandoned CA2020382A1 (en) | 1989-07-31 | 1990-07-04 | White light handleable negative-acting silver halide photographic elements |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0411819A3 (en) |
| JP (1) | JPH0368935A (en) |
| CA (1) | CA2020382A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1250717B (en) * | 1991-07-30 | 1995-04-21 | Minnesota Mining & Mfg | NEGATIVE-TYPE SILVER HALIDE PHOTOGRAPHIC ELEMENTS WITH EXTENDED LATITUDE OF EXPOSURE TO UV LIGHT. |
| DE69517160T2 (en) * | 1995-06-06 | 2000-11-16 | Agfa Gevaert Nv | Photographic materials |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59101646A (en) * | 1982-12-02 | 1984-06-12 | Konishiroku Photo Ind Co Ltd | Photosensitive silver halide material for daylight room |
| IT1186757B (en) * | 1985-07-11 | 1987-12-16 | Minnesota Mining & Mfg | 3-AMINOALLYLIDENMALONONITRILE UV ABSORBING COMPOUNDS AND PHOTOGRAPHIC ELEMENTS THAT CONTAIN THEM |
| JPS6280640A (en) * | 1985-10-04 | 1987-04-14 | Fuji Photo Film Co Ltd | Silver halide photographic sensitive material |
| JPH07109492B2 (en) * | 1987-06-18 | 1995-11-22 | コニカ株式会社 | Negative-type silver halide photographic light-sensitive material that can be handled in a bright room |
| IT1222087B (en) * | 1987-07-21 | 1990-08-31 | Minnesota Mining & Mfg | SILVER HALIDE PHOTOGRAPHIC ELEMENTS OF DIRECT POSITIVE TYPE HANDLING WITH WHITE LIGHT |
-
1990
- 1990-07-04 CA CA 2020382 patent/CA2020382A1/en not_active Abandoned
- 1990-07-25 EP EP19900308153 patent/EP0411819A3/en not_active Ceased
- 1990-07-30 JP JP20236290A patent/JPH0368935A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0411819A3 (en) | 1991-12-18 |
| EP0411819A2 (en) | 1991-02-06 |
| JPH0368935A (en) | 1991-03-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |