DE1447642B - Spectrally sensitized silver halide photographic emulsion - Google Patents

Description

The invention relates to a spectrally sensitized silver halide photographic emulsion comprising a sensitizing, non-ionized cyanine dye.

It is known e.g. B. from German patents 958 684 and 1 008 115, for spectral sensitization photographic silver halide emulsions to use non-ionized neutrocyanine dyes. It is also known from French patent specification 1,254,275 for spectral sensitization photographic silver halide emulsions to use non-ionized merocyanine dyes.

The disadvantage of the previously known, non-ionized neutrocyanine and merocyanine dyes is that they silver halide emulsions only face the green part of the spectrum in most cases

able to sensitize and / or have unsatisfactory negative blue sensitivities.

It is an object of the invention to provide a spectrally sensitized silver halide photographic emulsion

indicate that by adding a non-ionized cyanine dye compared to the yellow to red Area of the spectrum is sensitized and characterized by an improved minus blue sensitivity is.

The invention relates to a spectrally sensitized silver halide photographic emulsion with a sensitizing, non-ionized cyanine dye and is characterized by that they contain a cyanine dye of the fol-

contains the following formulas:

R - N (- CH =

-! - C = CH - C (= CH - CH) ^ ₁ = C

N -
CH (-R ₃ R ₉

C = C-CH (= CH-CH) _fc _, =

'Cn
O

₁₀

R-Nt-CH = CH) _n ^ -C = CH-C-CH = C- (CH = CH-),

O = C C = O

- R ₁

R ₃

where n, m, d and j each denote 1 or 2, k 1, 2 or 3, R and R _{1 are} alkyl groups having 1 to 12 carbon atoms, R _{2 is} a hydrogen atom or a methyl group, R ₃ and R _{4 are} either individually hydrogen atoms or alkyl groups with 1 to 12 carbon atoms, phenyl, benzyl, tolyl or carbalkoxy groups with 1 to 4 carbon atoms in the alkoxy groups or together the atoms which have a 5- or 6-membered structure with the carbon atom on which they are attached form carbocyclic ring, with the proviso that either only R ₃ or R _{4 can be} a hydrogen atom, R ₈ , R ₉ and R ₁₀ hydrogen atoms, alkyl or aryl groups, Z and Z _{1 are} those required to form a 5- or 6-membered heterocyclic ring Non-metal _{atoms, Z 2} the non-metal atoms required to form a 5-membered heterocyclic ring.

A common feature of the non-ionized cyanine dyes used according to the invention is thus a 1,3-cyclobutanedione residue. The new dyes can be according to customary known processes in incorporate photographic silver halide emulsions.

In the structural formulas given, for example: R and R ₁ methyl, ethyl, n-propyl, isopropyl, η-butyl, isobutyl,

sec-butyl, n-amyl, decyl, dodecyl, / S-hydroxyethyl, y-Hydro.xypropyl-, / I-methoxyethyl-, / 9-ethoxyethyl-, Allyl, benzyl, / 9-phenylethyl, /? - carboxyethyl, Carboxymethyl, y-carboxypropyl, /? - acetoxyethyl, y-acetoxypropyl, carbomethoxymethyl or

/ f-carbethoxyethyl groups; R ₃ and R ₄ methyl, ethyl,

Propyl, isopropyl, butyl, sec-butyl, amyl, hexyl,

Heptyl, decyl, dodecyl, allyl, phenyl, tolyl

or benzyl groups; Z and Z ₁ the non-metal

, atoms that each have one of the following rings

complete:

a thiazole ring, ζ..B. a thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole or a 4- (2-thienyl) -thiazoI-

ring; a benzothiazole ring, e.g. B. a Benzothia'zöl-, 4-chlorobenzothiazole, 5-chlorobenzothiazole,

6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, 5 - methoxybenzothiazole, 6 - methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylene benzothiazole, 5-hydroxybenzothiazole or a 6-hydroxybenzothiazole ring;

a naphthothiazole ring, e.g. B. an α-naphthothiazole, ß-naphthothiazole, 5-methoxy / S-naphthothiazole, 5-ethoxy- (S-naphthothiazole-, 8-methoxy-a-naphthothiazole- or a 7-methoxy-naphthothiazole ring;

a thianaphtheno-7 ', 6', 4,5-thiazole ring, e.g., a 4'-methoxythianaphtheno-7 ', 6', 4,5-thiazole ring; an oxazole ring, e.g. B. a 4-methyloxazole, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-Ethyloxazole, 4,5-Dimethyloxazole or a 5-phenyloxazole ring;

a benzoxazole ring, e.g. B. a benzoxazole, 5 - chlorobenzoxazole, 5 - methylbenzoxazole, 5 - phenylbenzoxazole, 6 - methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, 5-ethoxybenzoxazole, 6-chlorobenzoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole or a 6-hydroxybenzoxazole ring;

a naphthoxazole ring, e.g. B. an α-naphthoxazole or 8-naphthoxazole ring;
a selenazole ring, e.g. B. a 4-methylselenazole or 4-phenylselenazole ring;
a benzoselenazole ring, e.g. B. a benzoselenazole 5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole or a tetrahydrobenzoselenazole ring; a naphthoselenazole ring, e.g. B. an α-naphthoselenazole or ß-naphthoselenazole ring;
a thiazoline ring, e.g. B. a thiazoline or 4-methylthiazoline ring;

a 2-quinoline ring, e.g. B. a quinoline, 3-methylquinoline, 5-methylquinoline-, 7-methylquinoline-, 8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, 6-ethoxychino-Hn, 6-hydroxyquinoline or an 8-hydroxyquinoline ring; a 4-quinoline ring, e.g. B. a quinoline, 6-methoxyquinoline, 7-methylquinoline or one 8-methylquinoline ring;

an 1-isoquinoline ring, e.g. B. an isoquinoline or 3,4-dihydroxyisoquinoline ring; a 3,3-dialkylindolenin ring, e.g. B. a 3,3-dimethylindolenine, 3,3,5-trimethylindolenine or 3,3,7-trimethy Undo leninring;
a 2-pyridine ring, ζ. B. a pyridine, 3-methylpyridine, 4-methylpyridine, 5-methylpyridine, 6-methylpyridine, 3,4-dimethylpyridine, 3,5-dimethylpyridine, 3,6-dimethylpyridine, 4,5 -Dimethylpyridine-, 4,6-dimethylpyridine-, 4-phenylpyridine-, 5-chloropyridine-, 6-chloropyridine-, 3-hydroxypyridine-, 4-hydroxypyridine-, 5-hydroxypyridine-, 6-hydroxypyridine-, 3-phenylpyridine- , 4-phenylpyridine or a 6-phenylpyridine ring or

a 4-pyridine ring, e.g. B. a 2-methylpyridine, 3-methylpyridine, 3-bromopyridine, 3-chloropyridine, 2,3-dimethylpyridine-, 2,5-dimethylpyridine-, 2,6-dimethylpyridine-, 2-hydroxypyridine- or a 3-hydroxypyridine ring;

R ₈ , R ₉ and R ₁₀ methyl, ethyl, propyl, butyl, phenyl, p-tolyl or o-tolyl groups, Z ₂ the non-metal atoms that make up a thiazole, benzothiazole, naphthothiazole, thianaphtheno 7 ', 6', 4,5-thiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole or naphthoselenazole ring. In detail, Z _{2 can complete} one of the rings that were specified in connection with Z and Z _1. Furthermore, Z ₂ can, for example, take the place of the non-metal atoms that complete one of the following rings:

a 1-alkylbenzimidazole ring, for example a 1-methy lbenzimidazole, 1 - (7 - sulfopropyl) - 4 - chlorobenzimidazole, 1 - {ß - carboxyethyl) - 5 - chlorobenzimidazole, 1 - (/ 3-chloroethyl) -6 -chlorobenzimidazole, 1 - methyl - 4 - methylbenzimidazole, 1 - {ß - hydroxyethyl) - 5 - methoxybenzimidazole or 1 - (| S-acetoxyethyl) -6-hydroxybenzimidazole ring;

a 1-alkylnaphthimidazole ring, e.g. B. a 1 - methylnaphth [2,3-d] - imidazole-, 1 - (ω - sulfobutyl) -4-chloronaphth [2,3-d] -imidazole, 1 -ethyl-5-methylnaphth [2,3- d] - imidazole-, 1 - ethylnaphth [1,2-d] - imidazole-, 1 - butyl - 6 - chloronaphth [1,2-d] - imidazole-, 1 - (ß - carboxyethyl) 4-methylnaphth [2 , 1-d] -imidazole or 1-ethyl-5-hydroxynaphth [2, ld] -imidazole ring.

The new non-ionized dyes of the formula I, in which d = 1, can easily be prepared by reacting a 1,3-cyclobutanedione of the following general formula

R ₃

H ₂ C

R.
O

wherein R and R _{4 have} the meaning given, with a quaternary cyclammonium salt of the following general formula:

* 7

R-N (= CH-CH) _n _! =. C-CH = CA IV

Λ. Iv ₂

are prepared, where in formula IV R, R ₂ , η and Z have the meaning given and A is a group. of the formula - SR ₅ or - NR ₆ R ₇ , in which R ₅ in turn has the meaning of an alkyl group with 1 to 12 carbon atoms, for example a methyl to dodecyl group or an aryl group with 6 to 7 carbon atoms, ζ. Β. a phenyl, p-tolyl or o-tolyl group and in which R _{6 is} an aryl group having 6 to 7 carbon atoms and R _{7 is} an acyl group, e.g. B. an acetyl, propionyl or benzoyl group and in which X is also an acid

represents anion, for example a chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, Perchlorate or p-toluenesulfonate anion.

Dyes of the formula I in which d = 2 can be prepared as will be described later in connection with the preparation of dye no. 5. The 1,3-cyclobutanedione of the formula III can be used in the dione form or in the enol form.

The reaction of the two starting compounds can be carried out by heating the reaction mixture up to Reflux temperature, preferably in the presence of an inert solvent, e.g. B. ethanol, n-propanol,

n-butanol, pyridine, quinoline and isoquinoline, accelerates will. Preferably, in the implementation of the two compounds are equimolar Quantities used. The two compounds are advantageously reacted in the presence a basic condensing agent, e.g. B. a trialkylamine, such as triethylamine, tri-n-propylamine, Tri-n-butylamine, N-methylpiperidine, N-ethylpiperidine or N, N-dimethylaniline.

Dyes of the formula IA, in which k has the meaning of 2 or 3, can advantageously be obtained by condensation of a compound of the general formula

■ Ν —CHi = CH-CH) ^ ₁ = CC Α ..

O = CCH ₃ ^C ^ ⁴

in which R ₃ and R _{4 have} the meaning given for the atom, sulfur or selenium atom and q = 2 or 3, with a compound of the formula 25, can advantageously be prepared in that a compound of the formula

X-N =

-C- CH ₂
CH

WH

R ₈ R ₉

10

in which X, Z ₂ , R ₈ , R ₉ , R ₁₀ and j have the meaning given, are prepared. The reaction of the two compounds can be carried out in the same way as described in connection with the preparation of compounds of the formula I.

Compounds of formula (A) in which q = 2 can be prepared by the process described below for the preparation of 4 - (3 - acetanilidoallylidene) - 2,2 - dimethyl -1,3 - cyclo butanedione. Compounds of the formula (A) in which q = 3 can be prepared in a corresponding manner, but glutaconicaldehyde dianilide hydrochloride is used in place of / J-anilinoacroleinanil hydrochloride.

Dyes of the formula IA, in which k = 1, can advantageously be prepared by condensation of a compound of the formula III with a compound of the following formula:

X-N =

CH (-CH) -R ₈ R ₉

Ks v ^ rl I

CH O = C-CH ₃

wherein X, Z ₂ , R ₈ , R ₉ , R ₁₀ and; have the meaning given, are produced.

Compounds of the formula (B), in which Z _{2 represents} the one to complete a ring with an acidic NH,

wherein W denotes a sulfur, selenium or oxygen atom, T and T ₁ individually hydrogen atoms, alkyl groups, e.g. B. methyl, ethyl, propyl and butyl groups or aryl groups, e.g. B. phenyl groups or halogen atoms, e.g. B. chlorine, bromine or iodine atoms, or together the non-metal atoms necessary to complete a naphthalene compound, e.g. B. a 1-amino-2-WH-naphthalene compound, a 2-amino-3-WH-naphthalene compound or a 2-amino-1-WH-naphthalene compound or a derivative thereof with a lactone of the following formula

C CH ₂

0-CH (CH) ₇ TT-CH

R ₈ R ₉ Rio

in which R ₈ , R ₉ , R ₁₀ and j have the meaning given, is condensed.

The condensation is advantageously carried out in the presence of a compound which yields an acid anion performed, e.g. B. in the presence of phosphoryl chloride, hydrobromic acid, hydriodic acid or hydrochloric acid.

Compounds of the formula (B) in which Z _{2 represents} the atoms which complete a ring with 2 nitrogen atoms can be advantageously obtained by reacting a 1,2-diaminobenzene, a 1,2-diaminonaphthalene or a 2,3-diaminonaphthalene make with a lactone. Suitable lactones are e.g. B. y-butyrolactones, e.g. B. y-butyrolactone, / J-methyl-j'-butyrolactone, / J-ethyl-j'-butyrolactone, / J-Pro-

pyl-y-butyrolactone, ß-butyl-y-butyrolactone, ß- phenyl -γ- butyrolactone, β, γ - dimethyl - γ - butyrolactone, γ - methyl -γ- butyrolactone, γ -ethyl -γ- butyrolactone, 7- Propyl-γ-butyrolactone and ß- phenyl-γ-methyly-butyrolactone or o-valerolactone, e.g. B. o-valerolactone, β - methyl-o-valerolactone, / 3-ethyl- <5-valerolactone, (3-propyl-o-valerolactone, y-methyl-r5-valerolactone, γ- ethyl - «5-valerolactone, <5-methyl-o-valerolactone, ό-ethyl- (5-valerolactone, r5-propyl-o-valerolactone, ß- phenyl- 6- valerolactone, γ -phenyl-o-valerolactone, / ?, y-dimethyl-o -valerolactone or β, γ, δ-Ίτί- methyl-f5-valerolactone.

The diaminobenzenes or diaminonaphthalenes used for the reaction can optionally be substituted being. On the other hand, however, it is also possible to use these substituents later, i. H. after implementation with the lactone. The cyclization reaction can be carried out by heating the diaminobenzenes or diaminonaphthalenes and lactones are carried out at atmospheric pressure or at elevated pressure in an autoclave. In the presence of solvents, such as diphenyl ether or chlorobenzene, the reaction can take place at lower temperatures be performed. The reaction of a lactone with a diaminobenzene or Diaminonaphthalene can then easily be converted into the base by heating with an alkylating agent appropriate quaternary salt are transferred.

The particularly advantageous, non-ionized, trinuclear dyes of the formula II can be prepared by reacting a compound of the formula I, in which R _{2 has} the meaning of a methyl group and in which d = 1, with a quaternary cycloammonium salt of the following formula:

2-monosubstituted 1,3-cyclobutanediones or 2,2-disubstituted 1,3-cyclobutanediones hydrolyzed will. Diketenes and mixed dialkyl ketenes suitable for carrying out the process are also known from French patent 1,310,791.

The invention achieves that compared to the yellow to red region of the spectrum, spectral sensitized silver halide emulsions having an excellent negative blue sensitivity can be.

According to one aspect of the invention, the spectrally sensitized silver halide emulsion contains a cyanine dye of one of the following formulas:

15th

20th

R ₁ -M = CH-CH) _n ^ ₁ =
X

SR,

35

40 C = CH-C-CH = C

C = CH-C-CH = C

in which R ₁ , R ₅ , m, X and Z _{1 have} the meaning given, are prepared.

An excess is preferably used in this reaction of the quaternary salt is used, and preferably at temperatures up to reflux temperature the mix worked. The reaction is advantageously carried out in the presence of a basic one Condensing agent and an inert solvent, as already mentioned in connection with the preparation of compounds of formula I have been mentioned. The dyes can be obtained from the reaction mixture by precipitation into a nonsolvent such as water and ether, and subsequent recrystallization from a lower alkanol, such as methanol or ethanol, to be isolated.

A process for the preparation of compounds of the formulas IV and V is known from U.S. Reissue Patent No. 24,292. The cyclobutanediones of the formula III can be prepared according to the J. Orsi. Chem., 27 (1962), p. 3743; Rec. Trav. Chim., 77 (1958 "), p. 1159, and Rec. Trav. Chim., 81 (1962), pp. 549 to 553, known processes, according to which monoalkyl ketenes, dialkyl ketenes and diphynyl ketens are reacted with an alkoxyacetylene and the obtained alkoxy derivatives to the corresponding in which R, R ₁ , R ₃ and R ₄ are alkyl groups having 1 to 12 carbon atoms.

The dyes can also be represented by the corresponding holopolar structural formulas will:

C = CH-C = CH-C

or.

= CH-C = CH-C

009 524/206

C = CH-C-CH = C

4 - [(3-Ethyl-2-benzoxazolinylidene) ethylidene] -2,2-dimethyl-1 3'cyclobutanedione

, CH ₁

C = CH-CH = C

This embodiment of the invention is particularly advantageously spectrally sensitized Silver halide emulsions.

According to a further aspect of the invention, the spectrally sensitized silver halide emulsion contains a cyanine dye of one of the following formulas:

IO dye 2

4 - [(3-Ethyl-2-benzothiazolinylidene) ethylidene] -2,2-dimethyl-1,3-cyclobutanedione

_C H ₃

C = CH-CH = C

C ₂ H ₅

20th

■ 3 °

These cyanine dyes have been found to be particularly effective dyes.

In detail, the cyanine dyes can be produced, for example, as follows:

Dye 1

0.56 g of 2,2-dimethyl-1,3-cyclobutanedione, 2.25 g of 2 - β - acetanilidovinyl - 3 - ethylbenzothiazolium iodide and 1.4 ml of triethylamine were dissolved in 10 ml of ethanol, whereupon the solution was refluxed for 10 minutes was heated. After cooling, the reaction mixture was diluted with 1000 ml of chloroform and then washed several times with 100 ml portions of water. After filtering and drying, the chloroform solution was again separated by chromatography. The dye fraction was concentrated to dryness, whereupon the residue was taken up in 10 ml of methanol and allowed to cool. The dye was then filtered off. After two recrystallizations from methanol, 0.70 g (47%) of the dye with a melting point of 257 to 259 ^° C. (dec.) Were obtained.

Dye 3

4 - [(3-Ethyl-2-benzothiazolinylidene) isopropylidene] -2,2-dimethyl-1,3-cyclobutanedione

40

C = CH-C = C

I \

CH ₃

^ CH ₃

C ₂ H ₅

45

^S C ' ^X CH ₃

Il ο

0.56 g of 2,2-dimethyl-1,3-cyclobutanedione, 2.18 g of 2 - /? - AcetanilidovinyU3-äthylbenzoxazoliumjodid and 1.4 ml of triethylamine were dissolved in 10 ml of ethanol, whereupon the mixture was heated to reflux temperature for 10 minutes would. After cooling, the reaction mixture was diluted with 1000 ml of chloroform and washed with several 100 ml portions of water. After drying, the chloroform solution was separated by chromatography by means of a column about 30 cm long, about 2.54 cm in diameter and filled with neutral aluminum oxide. After the fraction obtained the dye was concentrated, the concentrate was recrystallized twice from benzene. 1.1 g (79%) of purified dye with a melting point of 188 to 190 ^° C. (dec.) Were obtained.

0.56 g of 2,2-dimethyl-1,3-cyclobutanedione, 2.06 g of 3-ethyl-2-ethylthiopropenylbenzothiazolium ethyl sulfate and 1.4 ml of triethylamine were dissolved in 10 ml of pyridine and the solution was refluxed for 10 minutes . After cooling, the crude dye was filtered off from the reaction mixture, washed with methanol and dried. The crude dye was purified by dissolving it in hot pyridine, filtering, and adding methanol to the filtrate to cause the dye to precipitate. After two recrystallizations, 1.0 g (64%) of dye with a melting point of 289 to 290 ^° C. (dec.) Were obtained.

Dye 4

4 - [(l-Ethylnaphtho Γ_ 1,2-d] thiazolin-2-ylidene) isopropylidene] -2,2-dimethyl-1,3-cyclobutanedione

C ₂ H ₅
1.5 g of l-ethyl-2-thioacetonylidene naphtho [l, 2-d] -

thiazoline and 1.02 g of methyl p-toluenesulfonate were mixed with one another and melted in a flask over a free flame. After cooling, 0.56 g of 2,2-dimethyl-1,3-cyclobutanedione and 1.4 ml of triethylamine and 10 ml of pyridine were added. The mixture was then heated to reflux temperature for 10 minutes and then allowed to cool. The precipitated crude dye was filtered off. The dye was dissolved in hot pyridine, filtered, and obtained from the filtrate by the addition of 0.97 g (54%) of pure dye having a melting point of about 300 ⁰ C.

dye

4- [4- (3-Ethyl-2-benzothiazolinylidene) -2-butenylidene] -2,2-dimethyl-1,3-cyclobutanedione

_// Cx _x / CH ₃ C = CH - CH = CH - CH = CC

1.42 g of 4 - (3 - acetanilidoallylidene) - 2,2 - dimethyl 1,3-cyclobutanedione, 1.85 g of 3-ethyl-2-methylbenzothiazolium-p-toluenesulfonate and 1.4 ml of triethylamine were dissolved in 10 ml of ethanol and heated to reflux temperature for 5 minutes. After cooling down the dye was filtered off, washed with a little ethanol and dried. After two recrystallizations 0.4 g (25%) of the pure dye with a melting point of 232 were obtained from ethanol to 233 ° C (dec.).

The 4- (3-acet-

anilidoallyliden) - 2,2 - dimethyl -1,3 - cyclobutanedibn was prepared as follows: 5.6 g of 2,2-dimethyl-1,3-cyclobutanedione and 13 g of jS-anilinoacroleinanil were obtained suspended in acetic anhydride and rapidly heated to reflux temperature. After 2 minutes it was the mixture is cooled in an ice-acetone bath, whereupon the precipitated reaction product is filtered off would. The filtered reaction product was then washed with cold acetic anhydride, dried and used without further purification. The yield was 6.1 g (43%)

Dye 6 4- [1,3-di- (3-ethyl-2-benzothiazolinylidene) isopropylidene] -2,2-dimethyl-1,3-cyclobutanedione

' ^s \ Λ

= CH-C-CH =

V; =

CH ₃

0.62 g of 4 - [(3-ethyl-2-benzothiazolinylidene) isopropylidene] - 2,2 - dimethyl -1,3 - cyclobutanedione and 1.40 g of 3-ethyl-2-ethylmercaptobenzothiazolium ethyl sulfate were suspended in 10 ml of pyridine, whereupon 1.4 ml of triethylamine were added. After heating at reflux temperature for 10 minutes, the reaction mixture was allowed to cool and 100 ml of CH ₃

Water and 100 ml of ether. After cooling overnight, the crude dye was filtered off and dried. After two recrystallizations from ethanol, 0.52 g (55%) of pure dye were obtained obtained with a melting point of 292 to 293 ° C (dec.).

Dye 7 4- [1,3-di '(3-ethylnaphtho [1,2-d] thiazolin-2-ylidene) isopropylidene] -2,2-dimethyl-1,3-cyclobutanedione

CH ₃

0.72 g of 4 - [(1-ethylnaphtho [1,2-d] thiazolin-2-ylidene-isopropylidene] -2,2-dimethyl-l , 3-cyclobutanedione and 1.77 g of 1-ethyl ^ -äthylmercaptonaphthorj ^ -djthi-

azolinium p-toluenesulfonate were dissolved in 10 ml of pyridine suspended, whereupon 1.4 ml of triethylamine were added. The resulting mixture was 10 minutes

heated to reflux temperature for a long time. After cooling, the mixture with 100 ml of water and 100 ml Stir ether until the dye became crystalline. The mixture was then chilled overnight, whereupon the crude dye is filtered off, treated with ether

washed and dried. After two recrystallizations from ethyl alcohol, 0.50 g (43%) of pure dye with a melting point of over 310 ^° C. were obtained.

dye

4- [5- (5-Ethyl-3-methyl-4- (5H) -piperidino [1,2-a] benzimidazolyl) -2,4-pentadienylidene] -

2,2-dimethyl-1,3-cyclobutanedione

C = C (- CH = CH) ₂ - CH = C / CHCH ₃

C (CH ₃ J ₂

C CH ₂

H ₂

Il ο

1.93 g of 5-ethyl-3-methylpiperidino [l, 2-a] benzimidazolium p-toluenesulfonate, 1.47 g of 4- (5-acetanilido-2,4-penudienylidene) -2,2-dimethyl-1,3-cyclobutanedione and 1.4 ml (1 mol + 100%) of triethylamine were dissolved in 15 ml of pyridine and for 10 minutes Heated to reflux temperature. The reaction mixture was then allowed to cool, followed by the crude Dye was precipitated by adding diethyl ether. Pyridine and ether were then decanted off. The remaining crude dye was dissolved in chloroform and then chromatographed Ways isolated using a column filled with neutral alumina. The the The fraction containing the dye was dried and the dye was recrystallized from ethanol.

The dyes are preferably added to the washed, ready-to-use silver halide emulsion added and evenly distributed in this. The dyes can be added to the emulsion, for example be added in the form of a solution. Suitable solvents are, for example, methanol and isopropanol and pyridine. The silver halide emulsion may consist of a conventional emulsion, to their Preparation of hydrophilic colloids used to disperse the silver halide, for example Gelatin, albumin, agar-agar, gum arabic and alginic acid or hydrophilic synthetic Resins such as polyvinyl alcohol, polyvinyl pyrrolidone, cellulose ethers and partially hydrolyzed Cellulose acetate.

The concentration of the dyes in the emulsions can be very different and for example from about 5 to about 100 mg per liter of flowable emulsion. The one required in the individual case Dye concentration depends, of course, on the type of photosensitive emulsion and those desired Effects. To achieve maximum sensitization effects with common gelatin silver bromide emulsions, including bromoiodide and chlorobromide emulsions, 10 to 20 mg of dye per liter of emulsion are sufficient. When using fine-grained Emulsions, which include most of the common gelatin silver chloride emulsions, can slightly higher dye concentrations are required to achieve optimal sensitization effects being.

Optionally, the dyes can also be incorporated thereby into photographic silver halide emulsions that recording materials are immersed in the solution of a dye.

Chemical sensitizers can also be added to the silver halide photographic emulsions of the invention be added, e.g. B. Sulfur containing sensitizers such as allyl thiocarbamide, Thiourea, allyl isothiocyanate and cystine or a wide variety of gold compounds, e.g. B. Potassium chloroaurate and auritrichloride, as described in U.S. Patents 2,540,085, 2,597,856 and 2,597,915 is known. Furthermore, the emulsions Palladium compounds are added, for example palladium chloride (see. USA. Patent 2,540,086) or potassium chloropalladate (see U.S. Patent 2,598,079).

Antifoggants can also be added to the emulsions of the invention, e.g. B. ammonium chloroplatinate (see US Pat. No. 2,566,245) or ammonium chloroplatinite (see US Pat 2 566 263) as well as benzotriazole, nitrobenzimidazole, 5-nitroindazole, benzidine and mercaptans (see Mees, "The Theory of the Photographic Process", Macmillan Pub., 1942, p. 460).

Furthermore, customary hardening agents, such as, for example, can be added to the emulsions of the invention from U.S. Patents 1,763,533 and 1,870,354 and British Patent 406 750 are known.

Finally, the photographic emulsions of the invention can also contain color couplers, as known, for example, from U.S. Patents 2,423,730 and 2,640,776.

The spectrally sensitized emulsions can be applied to the usual substrate, which are used for the production of photographic recording materials, such as, for example Glass, paper, cellulose acetate. Cellulose nitrate and synthetic film-forming plastics, e.g. B. polystyrene, Polyesters and polyamides.

example 1

Various proportions of a silver bromoiodide emulsion of that of Trivelli and Smith in Phot. Journal, 79, 330 (1939), with

0.77 mole percent iodide was added to various dyes according to the invention. The dyes were dissolved in a solvent and used in concentrations of about 40 to 130 mg per mole of silver halide. After digestion at 50 ° C. for 10 minutes, the emulsions were applied to cellulose acetate film support in such a way that 432 mg of Ag were ^{applied to a support area of about 930 cm 2.}

Samples of the recording materials were then exposed in a sensitometer ^x . Then they were developed for 3 minutes, fixed, washed and dried. The following results were obtained:

Sensitizing Sensitizing Emulsion type dye
No. area yield maximum (mji) ■ (ΓΠμ) Bromoiodide 5 to 530 Chlorobromide 6th 500 to 650 600 Bromoiodide 500 to 650 600 Chlorobromide 7th 500 to 670 620 Bromoiodide 500 to 700 670

Example 2

First, a silver bromoiodide emulsion containing 0.77 mole percent iodide was prepared according to the method described in Phot. Journal, 79, p. 330 (1939)

manufactured. Various proportions of the emulsion were shown in the table below Dyes incorporated after dissolving in a solvent.

The emulsions obtained were then transferred to

applied pherent support, whereupon the obtained Recording materials sensitometrically with tungsten light with the interposition of a No. 16 Wratten filters were exposed. The exposed recording materials were then

Then developed, fixed, washed and dried in the usual way for 3 minutes.

The relative minus blue sensitivities were determined for all test specimens. Simultaneously were further test items by a step wedge

exposed by spectrograph and then developed, fixed, washed and dried in the same way. The sensitization areas and sensitization maxima were derived from the step wedge spectrograms obtained read.

The results obtained are summarized in the following table:

concentration Awareness raising Awareness raising Relative " (g / mol AgBrJ) Area maximum sensitivity (ηΐμ) (mn) (Minus blue) dye 0.08 No. 6 of the invention to 640 560 100 according to Example 11 of the German 0.08 Patent specification 958 684 - up to 600 no def. 86.3 maximum according to example 14 of the German 0.08 Patent 958,684 to 660 585 83.4 according to example 15 of the German 0.08 Patent 958,684 to 645 590 91.5

The results obtained show the higher relative negative blue sensitivity of the dye No. 6 according to the invention.

Claims (3)

Patent claims: 1. Spectrally sensitized silver halide photographic emulsion with a sensitizing, not ionized cyanine dye characterized by being a cyanine dye of the following Formula contains: R - N (- CH = C = CH - C (= CH - CH) - C R, N CH (- R « / ^c \ Λ C = C-CH (CH = CH) _Ä _, = CC Ri 009 524/206 R - N (- CH = CH) ^ ₁ -C = CH - C - CH = C - (CH == ^ - N - R ₁ where n, m, d and j each denote 1 or 2, k 1, 2 or 3, R and R _{1 are} alkyl groups having 1 to 12 carbon atoms, R _{2 is} a hydrogen atom or a methyl group, R ₃ and R _{4 are} either individually hydrogen atoms or alkyl groups with 1 to 12 carbon atoms. Phenyl, benzyl, tolyl or carbalkoxy groups with 1 to 4 carbon atoms in the alkoxy groups or together the atoms which form a 5- or 6-membered carbocyclic ring with the carbon atom on which they are attached, where either only R ₃ or R _{4 can be} a hydrogen atom, R ₈ , R ₉ and R _{10 can be} hydrogen atoms, alkyl or aryl groups, Z and Z ₁ the non-metal atoms required to form a 5- or 6-membered heterocyclic ring and Z ₂ the non-metal atoms required to form a 5-membered heterocyclic ring Ringes required non-metal atoms. 2. Spectrally sensitized silver halide photographic emulsion according to claim 1, characterized in that it contains a dye of the following formulas: wherein R, R ₁ , R ₃ and R ₄ are alkyl groups with 1 to 12 carbon atoms. 3. Spectrally sensitized photographic silver halide emulsion according to claims 1 and 2, thereby characterized in that it contains a dye of the following formulas: