DE1063028B - Process for sensitizing halide silver emulsions - Google Patents

Description

GERMAN

The method according to the invention relates to the sensitization of halogen silver emulsions with cyanine or Styryl dyes which have at least one heterocyclically substituted nucleus of the general formulas

Process for raising awareness
of halogen silver emulsions

Y- N '
I. I. respectively. Y C. i
Ri I _E
\ / - C
^X N ' Yes

J
Ib

Applicant:

VEB Filmfabrik Agfa Wolfen,
Wolfen (district of Bitterfeld)

included at the end.

Here R is a heterocyclic radical which can be substituted as desired and can be in any substitutable position of the benzene ring, R _{1 is} an alkyl, aralkyl or aryl radical, Y is an O, S or Se atom, an NR ₂ -, CH = CR ₂ or CR ₃ R ₄ radical, R _{2 is} a hydrogen atom or an alkyl, cycloalkyl or aryl radical, and R ₃ and R ₄ are alkyl, cycloalkyl or aryl radicals.

These sensitizing dyes are made from compounds the general formula

Υ-Ι
R ₅ -C

II

W-

produced, in which R and Y have the same meaning as in formulas Ia and Ib and R _{5 is} a condensable group, such as. B. is an alkyl, cycloalkyl, aralkyl, alkyl mercaptan or aryl mercaptan radical or a halogen, according to the reactions known in cyanine chemistry.

The emulsions which can be prepared according to the invention have novel properties which are common to some photographic materials are particularly advantageous. In particular, the spectral sensitivity of halogen silver emulsions can be varied within certain limits by heterocyclically substituted sensitizing dyes. As a result, higher sensitivities can be achieved in certain spectral regions than with known cyanine dyes can be achieved. Since the introduction of the most diverse heterocyclic substituents in these sensitizing dyes is possible and can optionally contain further substituents in these, can be further achieve valuable properties of such sensitized materials. For example, can.? large volume «heterocyclic Remnants of the natural tendency of dyes to diffuse in photographic multilayer materials, the color couplers or filter dyes contain, completely or largely reduce, and likewise Dipl.-Chem. Dr. Günther Bach., Wolfen (district of Bitterfeld), has been named as the inventor

the clarity and coloration of the developed layers can be favorably influenced.

As an example of the change in the optical and photographic properties of halogen superemulsions by heterocyclically substituted sensitizing dyes the 3,3 ', 9-triethylbenzoxocarbocyanine is chosen, which is substituted in 5,5'- and / or 6,6'-position.

From this class are the dyes with 5,5'-phenyl substitution (I), 6,6 '~ phenyl substitution (II) and with 5,6,5 ', 6'-Benzoannellierung (III) as sensitizing dyes of halogen silver emulsions for the green Spectral range known (for the formulas of the dyes, see Appendix 1). The dye is of technical importance I for the sensitization of the purple layer of chromogenically developable halogen overlays for Negative and positive purposes, as it sensitizes selectively with a steep slope in the desired spectral range

and not diffused. Its superiority in terms of awareness level and intensity is demonstrated by comparison further clarified with the dyes II and III. It has now been found that by replacing the phenyl radicals Dyes IV and V obtained in dyes I and II by furyl residues differ in their optical properties behave very similarly and photographic properties, that, however, their sensitization maximum shifted by 10 to 15 ΐημ towards the longer wavelengths is. With these dyes, higher sensitivities can be achieved in the spectral range between 500 and 590 πιμ than can be achieved with the previously known, without the red sensitivity increasing significantly.

The introduction of other heterocyclic radicals, e.g. B. those of thiophene or benzoxazole, ver

909 £ 80/357

changes the photographic properties of such substituted cyanine dyes in a similar manner. To the A comparison of the dyes I to V was a bromiodide silver emulsion with the purple coupler Z 169 (cf. Cornwell-Clyne, Color Cinematography, third edition, 1951, p. 384) and then with the various Sensitizers, 3.0 mg per 100 ecm emulsion, added. The samples were placed on a film pad shed. Sample strips of this material were exposed in the same way by means of a spectrograph and in a p-methylaminophenol hydroquinone developer (e.g. »AGFA40«, see Lühr and Nürnberg, Rezepte, 1951, p. 30) developed in black and white. the Copies of the spectrograms obtained in this way can be seen from Appendix 2.

The sensitization of the halide silver emulsion by adding a dye solution in a water-miscible Solvent, the determination of the optimal dosage and the further evaluation of the poured and developed photographic layers are carried out according to the methods customary in photographic technology.

example 1

1 kg of a ready-to-cast silver halide emulsion is mixed with 40 mg of Ν, Ν'-diethylquinopseudocyanine and 2 mg of the dye of the formula

CH = CH- <f

CH,

sensitized and shed in the usual way. The sensitization maximum is 580 ηιμ. The awareness area extends from 500 to 590 πιμ.

The dye used above is prepared by fusing p-dimethylaminobenzaldehyde and 2-methyl-5- (2'-benzoxazolyl) -benzthiazole with anhydrous zinc chloride for 3 hours (mp 246 to 248 ° C from benzene). 2-methyl-5- (2'-benzoxazolyl) benzothiazole is prepared from 2 - (4'-chloro-3 '-nitrophenyl) - benzoxazole (F. 178-180 ⁰ C from n-butanol) by reaction with Na ₂ S ₂ recovered to the corresponding disulfide and reaction with glacial acetic acid-acetic anhydride-zinc dust in dioxane at 120 to 14O ⁰ C (160 ⁰ C to F. from 158 methanol).

Example 2

1 kg of a ready-to-cast halogen silver emulsion
with 30 mg of a dye of the formula

-0

^X;

-CH = C-CH = I

CH ₉ CH ₉ OSO;

CHXH-OSO ₁ H

sensitized and after adding the color coupler Z 169 (cf. BIOS Final Report Item No. 22, p. 78) encapsulated in the usual way. The maximum of sensitization is 560 to 565 ΐημ. The sensitization range extends from 500 to 580 ΐημ. The dye used above is short fusion of 1.0 g of 2-methyl-5- (2'-furyl) -benzoxazole with 0.6 g Äthylensulfat at 110 ⁰ C and subsequent condensation with 8 ml Orthopropionsäureäthylester in 5 ml of pyridine and 3 ml of glacial acetic acid within 2 hours at 140 ^° C., precipitation with ether and crystallization
(M.p. 226 ° C [decomposition]).

made from methanol 2-methyl-5- (2'-furyl) -benzoxazole is made by boiling 2-methyl-S-nitrosoacetylaminobenzoxazole with furan for 80 hours. After the excess furan has been distilled off, the residue is distilled in vacuo and the distillate is recrystallized from gasoline. (M.p. 60 to 62 ⁰ C, bp ₅ _ ₆ 154 to 155 ° C).

Example 3

1 kg of a ready-to-cast halogen silver emulsion is mixed with 30 mg of a dye of the formula

C ₉ H _S

CH = C-CH = I

OCH,

offset. A sharply pronounced sensitization maximum is obtained at 600 to 605 χημ. The sensitization range extends from 500 to 620 χημ.

The dye used above is prepared as follows: 2 g of 2-methyl-5- (2'-thienyl) -benzoxazole and 2.6 g of ethyl 2,4-dinitrobenzenesulfonate are converted into the corresponding quaternary salt by brief melting on the steam bath , 5 with 1.2 g of S-Äthylisothiopropionylanilid 30 minutes at 180 ⁰ C heated g. 1.5 g of the intermediate product thus obtained are condensed to the dye by heating for 1 hour at 125 ° C. with 0.95 g of 2-methyl-3-ethyl-5-methoxybenzthiazolium-p-toluenesulfonate in 3 ecm of pyridine-glacial acetic acid (5: 1) , which is precipitated with 2 ecm potassium] odide solution (20%) and recrystallized after boiling with water (mp 203 to 205 ° C from alcohol).

2-Methyl-5- (2'-thienyl) -benzoxazole (F. 68 to 70 ⁰ C from alcohol) is obtained from thiophene and 2-methyl-5-nitrosoacetylaminobenzoxazole.

Example 4

1 kg of a ready-to-cast halogen silver emulsion is mixed with 50 mg of a dye of the formula

C ₂ H ₅

= C-CH = ¹

CH ₂ CH ₂ COO "

sensitized and after adding the color coupler F 654 (see BIOS Final Report No. 1355 Item No. 22, p. 71) shed in the usual way. The range of awareness extends from 500 to 650 πιμ.

The above dye is made by heating 1.15 g of 2-methyl-6- (2'-thienyl) benzothiazole at 0.76 g for 1 hour jß-bromopropionic acid and subsequent ^ permanent Boil in 10 ecm pyridine-glacial acetic acid (5: 1) at 2 ecm Obtained ethyl orthopropionate (mp 204-206 ° C from alcohol).

CH ₂ CH ₂ COOH

2-Methyl-6- (2'-thienyl) -benzthiazole is prepared by diazotizing 2-methyl-6-aminobenzothiazole in dilute hydrochloric acid and then stirring the diazonium salt solution with thiophene for 15 hours in the presence of 5η sodium hydroxide solution. The thiophene layer is separated off and concentrated and the residue is distilled in vacuo (mp 83 to 85 ^° C. from alcohol).

Example 5

1 kg of a ready-to-cast halogen silver emulsion is mixed with 30 mg of a dye of the formula

NC ₆ H ₅

C ₆ H ₅ -N -CH = CH-CH =

CH,

sensitized and encapsulated after adding the Z 169 color coupler. The maximum of sensitization is 560 up to 565 ΐημ.

The dye used above is made by heating 1.6 g of l-phenyl-2-methyl-5- (2'-benzoxazolyl) benzimidazole with 5 ml of methyl iodide at 100 ° C in a sealed tube for 3 hours, then boiling the resulting iodine methylate for 3 hours 1 ml of ethyl orthoformate is obtained in 10 ml of nitrobenzene and precipitated with ether (mp 270 ^° C. from acetone).

CoH _K CH _a

l-Phenyl-2-methyl-5- (2'-benzoxazolyl) -benzimidazole is converted from 2- (4'-chloro-3'-nitrophenyl) -benzoxazole by Boiling with aniline, reduction of the 2- (4'-anilino-3'-nitrophenyl) -benzoxazole obtained (M.p. 161 to 163 ° C from acetone) with hydrogen in methanol in the presence of Raney nickel and boiling the diamine with glacial acetic anhydride (mp 127 to 128 ° C from gasoline).

40

: '- C H = C - C H =

CpHs

-CH = C-CH = C.H.SOI

C ₂ H ₅

O / λ. / \ C ₂ H ₅ _ | I.

III

C107

^s 0 '

ClOT

Claims (1)

Patent claims: Process for the sensitization of halogen silver emulsions, characterized in that these -R respectively. included at the end; here R is a heterocyclic radical which can be substituted as desired and in any substitutable position of the benzene ring, R _{1 is} an alkyl, aralkyl or emulsion, cyanine or styryl dyes are incorporated which have at least one heterocyclically substituted nucleus of the general formula Aryl radical, Y an O, S or Se atom, an NR ₂ , CH = CR ₂ or CR ₃ R ₄ radical, R ₂ a hydrogen atom, an alkyl, cycloalkyl or aryl radical, and R ₃ as well R ₄ are alkyl, cycloalkyl or aryl radicals. 1 sheet of drawings © 909 580/357 7.59