CA1038214A

CA1038214A - Silver halide emulsions and elements including sensitizers of adamantane structure

Info

Publication number: CA1038214A
Application number: CA214,518A
Authority: CA
Inventors: Edwin N. Oftedahl
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1974-07-29
Filing date: 1974-11-25
Publication date: 1978-09-12
Also published as: US3901714A

Abstract

SILVER HALIDE EMULSIONS AND ELEMENTS INCLUDING
SENSITIZERS OF ADAMANTANE STRUCTURE

Abstract of the Disclosure A photographic silver halide emulsion is disclosed which incorporates from 0.1 to 100 mg per mole of silver of a compound containing six imino groups bonded to four phosphorus, arsenic or antimony atoms. The compound incorporated is of adamantane structure and is useful as a sensitizer for the emulsion alone or in combination with known gold and/or sulfur sensitizers. The compound can be employed in combina-tion with an antifoggant, such as an azaindene. Photographic elements incorporating such emulsions are also disclosed.

Description

~03~Z~4 My invention relates to silver halide emulsions sensitized with Group VA elements containing imide compounds of adamantane structure and to photographic elements including such emulsions.
The use of compounds containing nitrogen and higher atomic number Group VA elements in combination as sensitizers for photographic silver halide emulsions and elements is known in the art. For example, British Patent 1,057,949, published February 18, 1967, teaches the sensitization of silver bromide emulsions by developing in the presence of an amido-phosphoric acid polyethylene glycol ester. British Patent 1,295,463, -~
published November 8, 1972, teaches that silver halide emulsions can be sensitized through the use of gelatin which has been treated with phosphine, arsine, stibine, white phosphorus or white arsenic or by the direct addition to the emulsion of white phosphorus or white arsenic. Willems et al U.S. Patent 3,552,968, issued January 5, 1971, teaches sensitization with phosphonitrile trimer and tetramer derivatives.
While varied compounds containing nitrogen and higher ~; 20 atomic weight Group VA elements in combination have been recognized to be sensitizers for photographic silver halide emulsions, it should not be assumed that such compounds are, in general, useful as silver halide sensitizers. Compounds containing nitrogen and higher atomic number Group VA elements~
in fact, cover the gamut of performance characteristics, ranging from desensitizers to sensitizers. Even among such compounds as have been observed to be sensitizers, many have exhibited an ineffectiveness and/o~ incompatibility with other chemical sensitizers. For example, some of these sensitizers in 30 combination with hea~ metal sensitizers, such as gold sensitizers~
produce no additional speed increase while others produce ~ prohibitively large increases in fog.
: - 2 -" , `~, 103~Z14 In one aspect then, my invention is directed to a photo-graphic silver halide emulsion improved by the incorporation of a sensitizing amount of a compound containing six imino groups bonded to four atoms of a Group VA element in an adamantane structural arrangement in which the four atoms of the Group VA element each exhibit an atomic number of at least 15.
My invention may be better appreciated by reference to the following description:
The compounds useful as sensitizers in the practice of my invention are those containing six imino groups bonded to four atoms of a Group VA element having an atomic number of at least 15 and preferably from 15 to 51--i.e., phosphorus, arsenic, antimony, etc. The imino groups can include sterically compatible hydrocarbon substituents, such as alkyl, aryl, alkaryl, aralkyl, etc. Typically the hydrocarbon substituents contain 10 (preferably : 8) or fewer carbon atoms. The alkyl groups and moieties each preferably incorporate 6 or fewer atoms while the aryl groups and moieties are preferably phenyl groups. The imino groups and j Group VA elements are related in an adamantane structure. These 20 compounds are generically designated 2,4,6,8,9,10-hexaaza-1,3,5,7-tetra(Group VA)-adamantanes, such as 2~ll,6,8,9,10-hexaaza-1,3,5,7-tetraphosphaadamantanes, 2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-arsaadamantanes, and 2,4,6,8,9,10-hexaaza-1,3,5,7-tetrastiba-adamantanes.
Preferred compounds of this type are those exhibiting -~ the structural formula .:
.

''`' .

. - ' ~038Z14 R-N N-R

/ N N \
z\ /z " \ /

., ` , :~.wherein, Z represents a Group VA element having an atomic number of from 15 to 51 inclusive and R is hydrogen or a hydrocarbon containing 8 or fewer carbon atoms. Specif`ically preferred hydroc~rbon substituents include methyl, ethyl, propyl, butyl, benzyl, phenyl, tolyl and similar substituents.
-Exemplary preferred adamantane compounds useful in :the practice of my invention are set forth below in Table I.

TABLE I
: 10 S.. -~
'l\
/ N-H
. H-N/ ¦ \ N-H

~/ \
:, \ /

\ N
H

2,4,6,8,9,10-hexaaza-1,395,7-tetraphosphaadamantane -~ ~

~03~

1`1/ ¦~
CH3- / P ~ ~-CH3 ¦ / N \ ¦

\ N /
CH3 -:
hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-phosphaadamantane /1 ~
CH3_~ ~ ¦ -CH3 As / As \ N /

hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5~7-tetra-arsaadamantane .~ ' '' ' ' '' ".

s-4 103~214 As 1~
C3H7-~ ~ ~ N-C3H7 : / \ C3H7 : / cN3H7 N \
A ~ / As ` N
, ~: hexapropyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-arsaadamantane s_~
As ' /1\
/ 1 4 9 \
:; C4H9-N~ I N-C4H9 As / \ ,C4iIg N N

A \ / As .: \ N /

hexabutyl-2,4,6,8~9,10-hexaaza-1,3,5,7-tetraarsa-adamantane .

... . . ~

~0~8214 / N
2-N ~ ¦ N CH2 / \CHZ~)¦

/CH2~' \ ¦
A ~ N / As H2~>
hexabenzyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-arsaadamantane ~ Sb CH3-i ~ ¦ N-CH3 ~S~

S / Sb N

hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-stibaadamantane ~ 03B214 s -8 / Sb ... /1\
/ I l-c3H7 \

3 7 ~ ~ 3 7 / ' \ C3H7 ~ / CN3H7 N
: S ~ ,b : 3 7 hexapropyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-stibaadamanatane b / 4 9 \
! ~4H9-~ ~ ¦ 4 9 / \ C4Hg / C4H9 \

Sb / ~ ;b \ N /
: 4H9 hexabutyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-stibaadamanatane ~, ~ -8-., .
: ~.: , . . - , :. .

Z~
S -lo Sb ~ N
: ~ I i ¦ N
~ / Sb /~) \
S \ / Sb \ N /
.:

hexaphenyl-2,4,6,8~9,10-hexaaza-1,3,5,7-tetra-stibaadamantane S-ll ~CH2- ¦ N-CH2~>

N ~ N
/CH2~> \ I :, Sb ~Sb \:N/
CH2~
hexabenzyl-2,4,6,8~9,10-hexaaza-1,3,5,7-tetra-.stibaadamantane _g_ lO;~Z~4 c CH ~ N N $

Sb / \ ~ CH3 / ~ CH3 \
S \ / c )b \ N /

hexa-o-tolyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetra-stibaadamantane The preparation of adamantane compounds useful in the practice of my invention is generally known in the art. For `'! example, the preparation of compounds of this type is taught by Dieter Hass, Z. Anorg. Allgem. Chem., Volume 325, pp. 139-148, March-April, 1963, and Volume 332, pp. 287-298, May-June; H. J.
Vetter et al, Z. Anorg. Allgem, Chem., Volume 328, pp. 144-153, March-April, 1964j Dieter Hass, Z. Chem., Volume 3, p. 391, October, 1963j and R. R. Holmes, J. Am. Chem. Soc., Volume 83, pp. 1334-1336, March, 1961.
The silver halide emulsions used in accord~nce with the sensitizers of my invention can comprise, for example, silver chloride, silver bromide, silver bromoiodide, silver chloro-bromide, silver chloroiodide, silver chlorobromoiodide and mixtures thereof. The emulsions can be coarse or fine grain emulsions prepared by any of the well-known techniques, e.g., single jet emulsions9 such as those described in Trivelli and Smith, The Photographic Journal, Vol. LXXI~, May, 1939 (pp 330-338); double jet emulsions, such as those described in Glafkides, Photographic Chemistry, Vol. 1, Chapter 28, Eountain Press, London, 1958; ammoniacal, thiocyanate or thioether ripened emulsions such as those described in Nietz et al U.S. Patent 2,222,264, issued November 19, 1940, Illingsworth U.S. Patent 3,320,069, issued May 16, 1967 and Jones U.S. Patent 3~574,628, issued April 13, 1971.
The silver halide emulsions utilized in this invention can be surface sensitized and/or internally sensitized. One convenient approach for forming internally sensitized emulsions is to sensitize the grain surfaces of an emulsion to be employed as a core emulsion followed by the further deposition of silver halide on the sensitized surfaces of the grains. Exemplary of internal image forming silver halide emulsions which can be used in the practice of this invention with adamantane sensitizers are those sensitized predominantly on the interior of the silver halide grains as described in Porter et al U.S. Patent 3,206~313, issued September 14, 1965; Porter et al U.S. Patent 3,317,322, ;` 20 issued May 2, 1967; Spence et al U.S. Patent 3,690,891, issued September 12, 1972; and Evans U S. Patent 3,761,276, issued September 25, 1973.
. . .
The silver halide emulsions can be regular grain emulsions such as the type described in Klein and Moisar, J.
Phot. Sci., ~ol. 12, No. 5, Sept./Oct., 1964, pp 242-251 and German Patent 2,107,118. Negative type emulsions can be utilized, as well as direct-positive emulsions as described in Illingsworth U.S. Patent 3,501,307, issued March 17, 1970 and Berriman U.S.
Patent 3,367,778, issued ~ebruary 6, 1968; such emulsions being surface fogged in addition to being internally sensitized.
~. ' , ~03~214 Inasmuch as the adamantane sensitizers of my inven-tion produce further enhanced photographic speeds when employed in combination with known chemical sensitizers, silver halide emulsions employed in the practice of my invention are pre-ferably chemically sensitized according to conventional practice in addition to including the adamantane sensitizers. My silver halide emulsions can be usefully sensitized with chemical sensitizers, such as with sulfur, selenium or tellurium compounds;

gold, platinum or palladium compounds; or combinations of these.
Procedures for chemically sensitizing silver halide emulsions are described in Sheppard et al U.S. Patent 1,623,499, issued April 15, 1927; Waller et al U.S. Patent 2,399,083, issued April 23, 1946;
McVeigh U.S. Patent 3,297,447, issued January 10, 1967, and Dunn U.S. Patent 3,297,446, issued January 10, 1967.
My adamantane sensitizers can be added in a variety of ways to photographic emulsions and at various stages in the -preparation thereof; however, I prefer to introduce the adamantane sensitizers of my invention immediately after chemical sensitiza-tion by conventional techni~ues has been completed and before other addenda have been incorporated into the emulsion. The sensitizers can be added with useful effects at the completion of Ostwald ripening and prior to one or more of the final digestion operations. The sensitizers are preferably added to the silver halide emulsion after the silver halide grains are substantially in their final size and shape. The adamantane sensitizers can be added in methanol, acetone or other innocuous organic solvents. To avoid thermally degrading the adamantane sensitizers it is generally preferred that the silver halide emulsion not be maintained above a temperature of about 50 to :i ,~ .

~03~Z~14 60C for an extended period in preparation steps subsequent to adamantane incorporation. Effective adamantane sensitization can be obtained by holding the emulsion at an elevated tempera-ture of up to about 40c or more for a period ranging from a few minutes to an hour or more--preferably 10 to 40 minutes.
Any sensitizing amount of the adamantane compounds of this invention can be usefully incorporated into the silver halide emulsion. Typically concentrations of from about 0.1 to 100 mg of adamantane sensitizer per mole of silver halide, preferably o.5 to 50 mg of adamantane sensitizer per mole of silver halide, can be employed.
Since higher concentrations of the adamantane sensitizers can raise fog levels, the maximum concentrations of the adaman-tane sensitizers is a function of (a) the amount of background fog compatible with the particular photographic application and (b) whether or not an antifoggant is incorporated in the silver halide emulsion. While the adamantane sensitizers are ~, generally compatible with known antifoggants and stabilizers, I have found the adamantane sensitizers employed in the practice 20 of this invention to be particularly effective in combination with known azaindene antifoggants, most preferably tetrazaindene ~; antifoggants. Exemplary antifoggants and stabilizers, each used alone or in combination include the following:
a) thiazolium salts described in Brooker et al U.S.
; Patent 2,131,038, issued September 27, 1938 and Allen et al U.S.
Patent 2,694,716, issued November 16, 1954;
b) the azaindenes described in Piper U.S. Patent 2,886,437, issued May 12, 1959 and ~eimbach et al U.S. Patent : , 2,444,605, issued July 6, 1948, ~03~Z~4 c) the mercury salts as described in Allen et al U.S.
Patent 2,728,663, issued December 2-1, 1955;
d) the urazoles described in Anderson et al U.S. Patent 3,287,135, issued November 22, 1966;
e) the sulfocatechols described in Kennard et al U.S.
Patent 3,236,652, issued February 22, 1966;
f) the oximes described in Carroll et al British Patent : 623,448, issued May 18, 1949;
~: g) nitron;
h) nitroindazoles;
i) mercaptotetrazoles described in Kendall et al U.S.
Patent 2,403,927, issued July 16, 1946; Kennard et al U.S. Patent 3,266,897, issued August 16, 1966; and Luckey et al U.S. Patent 3,397,987, issued August 20, 1968;
~ . j) the polyvalent metal salts described in Jones U.S.
`; Patent 2,839,405, issued June 17, 1958, k) the thiuronium salts described in Herz et al U.S.
Patent 3,220,839, issued November 30, 1965; and 1) the palladium, platinum and gold salts described in Trivelli et al U.S. Patent 2,566,263, issued Au~,ust 28, 1951; and Yutzy et al U.S. Patent 2,597,915, issued May 27, 1952.
In addition to the components above mentioned the silver halide emulsions include a vehicle for dispersing the silver halide grains. The vehicle is typically a hydrophilic colloid, such as gelatin, but can take any conventional form.
In addition, the silver halide emulsion can contain any one or a variety of conventional photographic emulsion addenda, such as - hardeners, spectral sensitizers, brighteners~ coating aids, plasticizers and lubricants, absorbing and filter dyes, develop-ing agents, development modifiers, etc. Typical conventional vehicles and addenda of this type useful in the practice of this -14 _ Z~4 invention are disclosed in Product Licensing Index, Vol. 92, ~ecember 1971, publication 9232, pages 107 through 110, here incorporated by reference.
The photographic emulsions according to my invention can be employed as coatings in single and multi-layer photographic elements. Such elements typically include a conventional photo-graphic support of the type disclosed specifically in paragraph X of Product Licensing Index, cited above. The photographic emulsion layers can be employed in combination with subbing, interlayers, Carey Lea silver layers, antihalation layers, etc., as is well understood in the art.
The photographic elements according to my invention can be applied to a variety of applications. The photographic elements can be used with X-rays or can be orthochromatic, pan-chromatic or infrared sensitive. The photographic elements can be employed to form black-and-white images or to form colored or multi-colored images in one or a plurality of layers as taught specifically in paragraph XXII of Product Licensing Index, cited above. The photographic elements can be of a type which form 20 images upon development in conven-tional silver halide developing solutions, which form images by dry physical development, which form images by image transfer~ etc. The photographic elements can be employed as lithographic printing plates as taught in paragraph XXIV of Product Licensing Index, cited above. The photographic elements can be formed to produce positive or nega-tive images and can be formed to be of the direct print type, as specifically disclosed in paragraph XXV of Product Licensing Index, cited above.
The following examples are intended to further illus-trate my invention.
`

_. ~

~0~214 Example 1 A silver bromide emulsion having a mean grain size of 0.4 micron in diameter was prepared using a conventional double ~et technique. To the emulsion were added a conventiGnal spread-ing aæent, hardening agent and antifoggant, the antifoggant being

4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene. The emulsion was separated into equal portions and chemically sensitized to a maximum obtainable speed using the reduction sensitizers in the concentrations set forth below in Table II. The emulsion samples were then coated on a film support at 29 mg silver per square decimeter, exposed, developed for 4 minutes in~Kodak Developer D-l9 (the composition of which is set forth at page 43 of Kodak Advanced Data Book J-l, titled Processing Chemicals and Formulas for Black-and-White Photography, 6th edition, published 1963), fixed, washed and dried. -TABLE II

;~ Reduction Concentration Fresh Sensitizer m~ Sens/mole A~ Relative Speed Fog None None 100 0.03 thiourea dioxide 2.0 209 0.03 S-2 0.2 977 0.04 Table II shows hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5~7-tetra-; phosphaadamantane to be a sufficiently effective sensitizer to increase the relative speed of the emulsion more than 9 times.
At the same time, Table II shows that the adamantane sensitizer is more than 4 times as effective as thiourea dioxide, a conven-; tional reduction sensitizer, even when incorporated in a concentra-tion which is an order of magnitude lower. This shows the adamantane sensitizer to be a surprisingly effective sensitizer.
*trademark - ~ -. - -- ~

10;36Z14 Example 2 Example 1 was repeated, except that no antifoggant was incorporated and the sensitizers and concentrations were employed as set forth below in Table III.
TABLE III

Reduction Concentration Fresh Sensitizer mg Sens/mole ~ Relative Speed None None 100 0.04 -~

tris(diethyl~
amino)phosphine 1.0 257 0.04 .. :
S-2 0.3 832 0.04 Table III shows the adamantane sensitizer to be sufficiently effective in the absence of an antifoggant to increase the relative speed of the emulsion by more than 8 times. At the same time, Table III shows the adamantane sensitizer to be more than 3 times as effective as tris(diethylamino)phosphine, a sensitizer disclosed in my U.S. Patent No. 3,904,415, issued September 9, 1975, entitled PHOSPHINE SENSITIZED PHOTOGRAPHIC
.. ...
SILVER HALIDE EMULSIONS AND ELEMENTS. This further illus-20' trates the surprlsing effectiveness of the adamantane sensitizers of my invention.
Examples 3 through 5 The procedure of Example 2 was repeated, except that the mean diameter of the silver bromide grains was 0.2 micron and the sensitizers and sensitizer combinations and concentra~
tions were employed as set forth below in Table IV.
Table IV shows that the adamantane sensitizer is more .~ effective than the sulfur sensitiæer or a combination of the : sulfur sensitizer and the gold sensitizer, even though the :~ adamantane sensitizer is employed in a much lower concentration.
Table III further shows the adamantane sensitizer to more than double the emulsion speed when combined with the sulfur sensitizer o ~
~ o o o o o o U~ ~
s~ $~
U2 ., .
:'`
. .
. ~ ~, ~ .
.,, ,_ . ~ ~, a r~ . ~ ~ .
~Q ~ .
m ~¢

¢ CC
a) ~ +
c~ u2a~ ~ - .
~ o ~ ~ ~ ~
3 Z;~ ~ o o o :, -~ o o , ~U C~l o . o 13 td ~
v ~1 ~ æ æ

.

.
: .

. , i..... . .
. . . ~. -~ .... . .
:. . ~- . - .

~3B%14 as compared with the speed obtainable with the adamantane sensitizer alone and to produce a relative speed increase of more than 5 times as compared to the emulsion containing the sulfur sensitizer alone. The combination of the adamantane sensitizer, the sulfur sensitizer and the gold sensitizer pro-duces an emulsion having a relative speed more than 17 times greater than that of the unsensitized emulsion, more than 11 times greater than that of the sulfur sensitized emulsion, more than 6 times greater than that of sulfur and gold sensitized emulsion and more than twice that of the adamantane and sulfur sensitized emulsion. Further, Table III shows that the adamantane sensltizer does not increase fog levels in ` combination with gold and/or sulfur sensitizers.
The invention has been described with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

: ' .'. '.
',"

.

Claims

I CLAIM:

1. In a photographic silver halide emulsion the improvement comprising the incorporation of a sensitizing amount of a compound of the structural formula wherein, Z represents a Group VA element having an atomic number of from at least 15 inclusive and R is hydrogen or a hydrocarbon containing 8 or fewer carbon atoms.

2. In a photographic silver halide emulsion according to claim 1, the further improvement in which said emulsion is additionally sensitized with a gold sensitizer, a sulfur sensitizer or a combination of gold and sulfur sensitizers.

3. In a photographic silver halide emulsion according to claim 2, the further improvement in which said emulsion contains an azaindene antifoggant.

4. In a photographic silver halide emulsion according to claim 3, the further improvement in which said emulsion contains a tetrazaindene antifoggant.

5. In a photographic silver halide emulsion the improvement comprising the incorporation of a sensitizing amount of a compound of the structural formula wherein, Z represents a Group VA element having an atomic number of from 15 to 51 inclusive and R is hydrogen or a hydrocarbon containing 8 or fewer carbon atoms.

6. In a photographic silver halide emulsion according to claim 5, the further improvement in which said Group VA element is phosphorus.

7. In a photographic silver halide emulsion according to claim 6, the further improvement in which R is an alkyl group having 8 or fewer carbon atoms.

8. In a photographic silver halide emulsion, the improvement comprising the incorporation of a sensitizing amount of` a compound having the structural formula .

9. In a photographic silver halide emulsion, according to claim 8, the further improvement in which said emulsion is additionally sensitized with a gold sensitizer, a sulfur sensitizer or a combination of gold and sulfur sensitizers.

10. In a photographic silver halide emulsion according to claim 9, the further improvement in which said emulsion contains an azaindene antifoggant.

11. In a photographic element comprised of a support and, as a coating thereon, a photographic silver halide emulsion layer, the improvement in which said emulsion is as set forth in claim 1.

12. In a photographic element according to claim 11 the further improvement in which said emulsion includes gold sensitizing means, sulfur sensitizing means, or a combination of gold and sulfur sensitizing means.

13. In a photographic element according to claim 12, the further improvement in which said emulsion includes anti-foggant means.

14. In a photographic element according to claim 11, the further improvement in which said emulsion includes a phosphorus imide sensitizer.

15. In a photographic element comprised of a support and, as a coating thereon, a photographic silver halide emulsion layer, the improvement in which said photographic silver halide emulsion includes a sensitizing amount of hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetraphosphaadamantane, gold sensitizing means, sulfur sensitizing means or a combination of gold and sulfur sensitizing means, and azaindene antifoggant means.