HU203120B - Process for reductive sensibilisation of silver-halogenid foto-emulsions - Google Patents

Abstract

Silver halide photographic emulsions made by precipitating silver halide crystals in a protective colloid solution, growing them up to the size required and optionally removing the excess ions are reductively sensitized introducing into the emulsion in an amount 100-500 mu mol/mol of silver halide by an inclusion complex consisting of a cyclodextrin of the general formula (I> CD-(O-R)K (I> or a cyclodextrin polymer of the general formula (II> <IMAGE> containing 30 to 70% of cyclodextrin and having an average molecular weight of 2000 to 15000 as well as a hydrazine derivative of the general formula (III> R<1>-NH-NH-R<2> (III> the molecular ratio of the cyclodextrin monomer in the inclusion complex to the sensitizing agent, being between 4:1 and 80:1.

Description

The present invention relates to a process for reducing the sensitization of a silver halide photographic emulsion by inclusion complexes of hydrazine derivatives with substituted cyclodextrins or water soluble cyclodextrin polymers.

The purpose of chemical sensitization of silver halide crystals is to render a certain proportion of them crystallized with lower illumination. One method of sensitization is the reduction process, which involves the use of a suitable reducing agent to create very small sensitivity centers on the surface of the crystals, consisting of several hundred silver sticks.

The reducing agents most commonly used are tin (II) compounds, ascorbic acid, formamidine sulfinic acid, silanes (H. FRIESER, E. KLEIN: Grundlagen et al. Photographs of Silberhalogeniden, 1986, Akademische Verlaggesellschaft, Frankfurt, Vol. 677). Amino-boranes (U.S. Pat. No. 3,761,276) and U.S. Pat. and also hydrogen gas (U.S. Patent Nos. 3,891,446 and 3,984,249).

Reduction sensitization with hydrazine has long been known (as early as 1943 in U.S. Patent No. 2,410,690), but has not been widely used in industry. This is due to the fact that the emulsion is already veiled in relatively small amounts (e.g., S.S. COLLIER: International Congress of Photography, ICPS, 1978, Rochester, p. 130).

Therefore, hydrazine and its derivatives (e.g., hydrazine dihydrochloride, phenylhydrazine hydrochloride, p-methylsulfonamide-ethylphenylhydrazine, etc.) are used in direct positive emulsions as described in U.S. Patent No. 3,761,276. U.S. Pat.

The veiling properties are related to the relatively strong reducing effect of hydrazine and some of its derivatives. This allows them to be used as a photographic developer in addition to the appropriate components, for example. phenylhydrazine, naphthylhydrazine, hydrazobenzene, aliphatic hydrazine derivatives, carboxyphenylhydrazine, diphenylhydrazine, and the like. (T.H.JAMES: Theory of the Photographic Process, New York, 1977, p. 310).

SUMMARY OF THE INVENTION An object of the present invention is to provide hydrazine derivatives for use in the reduction sensitization of photographic emulsions. The use of these compounds may be interesting because their oxidation in the photoemulsion is irreversible, and thus their action is comparable to hydrogenation sensitization which is otherwise advantageous but problematic in industrial feasibility.

No. 200081. According to the Hungarian patent, water-soluble monomers and polymers containing various substituents are unstable sulfur or selenium, respectively. The inclusion complexes of tellurium with thiazolidine, oxazolidine, imidazolidine and selenazolidine derivatives are useful for the chemical sensitization of silver halides.

The present invention is based on the discovery that hydrazines containing aromatic or aliphatic ring substituents also form water-soluble inclusion complexes with cyclodextrin derivatives,

The invention is based on the discovery that took The lock ² ványkomplexbe hydrazine derivatives are capable of reduction sensitization without significantly incremented in the veil.

Cyclodextrins are cyclic, non-reducing oligosaccharides composed of α-D-glucopyranose units, which are known primarily for their inclusion complexing properties (J. SZEJTLI: Cyclodextrins and their Inclusion Complexes, Akadémiai Kiadó, Budapest, 1982). Most commonly, α-, β- or γ-cyclodextrins of 6, 7 or 8 glucopyranose units are used. They are produced by enzymatic decomposition of starch.

Α-cyclodextrins 18, β- and γ-derivatives 21 and 21, respectively. They contain 24 free alcohol groups. Their reactivity enables the various substituted derivatives of the monomer to be used. water-insoluble and water-insoluble polymers.

The sulpho and / or sulphonate moieties obtained by substitution of the monomer (for example, by reaction with chloroacetic acid or butanesulfone). carboxy derivatives are distinguished by their good water solubility.

Water-soluble, medium molecular weight cyclodextrin polymers can be prepared by a variety of methods. In one method, an unsaturated, polymerizable derivative is first obtained from cyclodextrin, which is then polymerized alone or with a monomer without cyclodextrin [J.Polym. Sci. Letters, 13, 357 (1975)]. Alternatively, cyclodextrin molecules may be solubilized with a dual-function reagent, e.g. is converted to a linear or branched water-soluble polymer product containing diepoxides or epichlorohydrin (Hungarian Patent No. 180,597) or to a water-soluble polymer product substituted with ionic groups (Hungarian Patent No. 191,101). Reagents which interact with alcoholic hydroxyl groups in the alkaline media used in the preparation of the polymer (e. G., Haloalkylamines or aminoalkylcarboxylic acids) or those which are used in the preparation of ionizing functional groups are used. They may react with one of the epoxy groups on the coupling agent or with the epoxy groups formed at the end of the chain during polymer preparation.

According to the present invention, the silver halide crystals are precipitated in a protective colloidal solution, enlarged to the required size, and optionally, after removal of excess ions, for reduction sensitization from the cyclodextrin of formula (I).

CD ¹ : group derived from the removal of k hydrosyl groups from α-, β- or γ-cyclodextrin

R ^{1 is} hydrogen, or R "COOCH, R" SO ³ H, R "NH ₂ - wherein R" is a linear or branched alkylene group containing Ιό C, an integer from 1 to 5, or a compound of formula II Containing from 30 to 70% by weight of cyclodextrin, with an average molecular weight of 200015 000,

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Bow

CD and CD are the derivative of the α, β, or γ-cyclodextrin molecule which can be derived by removing p + s for CD ² and 1 + r + t for CD,

R and R 'are independently -CH 2 -, -CHOH-CH 2 -, -CH 2 -O- (CH 2) 2 -O-CH 2 CHOH-CH ₂ -CH ₂ -O-CH ₂ -CHOH-CH _{2 -} , or CH ₂ O (CH 2). ) 4-O-CH 2 CHOH-CH 2 -,

X is -OR ¹ , or -OR ^2, or NR 1 -R ^{5 in} which

R ¹ is hydrogen or, when different from r ^{0, it} is a derivative of the α-, β- or γ-cyclodextrin which can be derived from a hydroxyl group,

R ² is hydrogen, -PO (OH) 2, or

-SO2OH group of the formula -R- (COOH) n, R ³ -SO ₂ OH, R ^ NRV radical or an α-, β- or γ-cyclodextrin molecule by removing a hydroxy group can be derived,

R ² has the same meaning as R ² other than the above derivative of a cyclodextrin molecule,

R ^{3 is} a u + 1-valent C 1 -C 10 alkane-derived group whose carbon at the terminal end of the polymer may be optionally substituted with oxo,

R ⁴ and R ⁵ each independently represent hydrogen or C 1 -C 4 alkyl, m and n each independently represent an integer from 1 to 10, r an integer from 0 to 23, p an integer from 1 to 24, s and t independently 0 is an integer from 7 to 7, and u is an integer from 1 to 5, with the proviso that m, n, r, t and u may vary within a unit,

CD ² and CD are a group derived from α-cyclodextrin, then p + s <18 and r + t <17, and if

CD ² and CD are a group derived from β-cyclodextrin, then p + s <21 and r + t <20, and if

CD ² and CD derived from γ-cyclodextrin is a group, then p + s <24 and r + t <23, and the hydrazine derivative of the general formula (III),

- in the formula

R ^{6 is} quinolyl, pyridyl, or cyclohexyl, or (a), (b), (c), (d), (e), (f), (g), or (h);

R ^{7 is} hydrogen, phenyl,

R ^{8 is} hydrogen, halogen, C 1-4 alkyl or alkoxy, or sulfonamido,

R ⁹ , R ^{10 are} hydrogen or halogen,

R ^{11 is a C} 1 -C 4 alkyl or alkoxy-encapsulated inclusion complex in the photographic emulsion in an amount of 10-500 pmol / mole, preferably 25-100 pmol / mole, of silver halide per reducing agent, while the CD monomers in the inclusion complex are the sensitizing compound. the calculated molar ratio of Q- [CD] / [S] is from 4: 1 to 80: 1, preferably from 10: 1 to 50: 1.

To calculate the value of Q [CD] - (0.01cc) / 1135, where: c is the amount of cyclodextrin derivative in g in 1 liter of solution; m - the CD monomer content of the cyclodextrin derivative, mole%; 1135 - molecular weight of the CD monomer.

In the process of the invention, reduction sensitization can be combined with sulfur and gold sensitization. In this case, the inclusion complex containing the reducing agent is preceded by a sulfur and a gold compound, between the two. they may be administered after they have been administered.

In accordance with the invention, the reduction sensitization may be carried out by sulfur sensitization and in accordance with Table VIII of the Periodic Table. is combined with sensitization with one of its elements (preferably Irish, Pt, Pd, Ru), while the inclusion complex is characterized by sulfur and VIII. column element, between the two, respectively. they may be administered after they have been administered.

According to the invention, it is still possible to apply reduction sensitization after the silver halide crystals have been enlarged to a certain size, and then to further increase the crystals to a specified size, thereby forming a core / shell structure. Sulfur and gold sensitization is optionally carried out on the surface of the shell.

According to the present invention, the inclusion complex containing the reducing agent is added to the emulsion after the crystals have been enlarged to a specified size and then recrystallized from the surface of the existing crystals by adding the halide necessary to form a silver salt less soluble than the precipitate silver halide.

According to the invention, the inclusion complex containing the reducing agent can also be introduced into the protective colloid solution prior to precipitation of the silver halide crystals, so that reduction can take place throughout the course of crystal formation and growth.

In the process of the invention, the emulsion is provided with the usual additives upon completion of maturation. These include color sensitizing dyes, stabilizers, tanning agents, wetting agents, etc.

Color sensitizers include, for example, 1-ethyl-3'-phenyl-2-quino-5'-rhodanine (Dye I); 3,3'-diethyl-1'-phenylbenzoxazolidene (ethylidene-2'-thiohydantoin) (to Dye; 3,3'-diethyl-6,6'-dinaphthyl-9-phenylthiocarbocyanine (Dye-ΠΙ), benzothiazole; phenyl-2-thiohidantoin-tetramethine-merocyanin (Dyes-IV) (P.GLAFKIDES: Photographic Chemistry, Vol. 8, pp. 832-836, Fountain Press, London, 1960).

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Examples of stabilizers that may be used include 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindole (TAI), 1-phenyl-5-mercaptotetrazole (FMT), mercaptobenzothiazole (MBT), mercaptobenzoxazole ( MBO), etc. (G.F.DUFF1N: Photographic Emulsion Chemistry, Photo Press, London, 1966, pp. 138-141).

Tanning agents include, for example, formalin, glutaraldehyde, glyoxal, 2,4-dichloro-6-oxy-s-triazine, and the like. (T.H.JAMES: Theoiy of the Photographic Process, Fourth Edition, McMillan, New York, 1977, p. 82).

Suitable wetting agents include, for example, alkenyl succinic polyglycerides, dodecyl phenol polyglycol ether, saponin, and the like. (B.M.DERJAGIN; S.M.LEVI: Film Coating Theory, Focal Press, London, 1966,

162).

The inclusion complex is prepared by dissolving the necessary amount of a reducing sensitizer in an aqueous solution of the cyclodextrin derivative.

For complexation, solutions of 1-10% of the substituted monomer and 2-20% of the water-soluble polymer are prepared. The cyclodextrin solution was dissolved in 10 ^'4 -10 ² mol / liter of a sensitizing.

The compounds of Tables 13 may optionally be used in the process of the invention.

Table 1. Compounds derived from a compound of formula (I)

mark R ¹ k ml 2 COOH 3 M2 2 COOH 5 M3 - (CH2) 4SO3H 1 M4 - (CH2) 3SO3H 3 M5 -N (C ₂ H 5) 2 2

Advantages of the process according to the invention are as follows:

1. The hydrazine derivatives of the invention, with the exception of phenyl hydrazine, have a low or very poor solubility in hydrochloric acid salts; some of them are soluble in ethanol but are separated from the solution at room temperature.

In contrast, these same compounds ciklod20 extrin derivatives are highly soluble in aqueous solution at a concentration of even 10 ^'2 mol / liter, which allows their convenient loading on the photoresist.

2. Hydrazine derivatives decompose in aqueous solution and increase in stability as an inclusion complex. E. Storage also phenylhydrazine 10 ^'3 mol / L aqueous solution of 6'-C by reduction potential for reduced to 30% during 8 days, while a 10% solution of the same conditions e.g.

Table 2. Compounds derived from the compound of formula (II)

sign Average CD Carboxi Nit- Sulfur R ² ' S t R R ² m n X r P mw ro R ' M _w gene Content% E.g 5339 63.8 3.37 - CH 2 COOH 1 1 CH2 CH 2 COOH and H 2 21 CD 1 1 P2 5810 57.7 1.93 - - 0 0 CH2 CH 2 N (C 2 H 5) 2; and H 8 12 CD 1 1 P3 6019 55.7 - 3.19 - 0 0 CH2 (CH 2) 4 SO 3 H and H 6 12 CD 1 1 P4 5709 59.6 1.57 1.47 - CH 2 COOH 2 0 CH2 CH 2 N (C 4 H 9) 2 and 6 18 CD 1 1 P5 3893 58.3 2.30 0.70 - B 1 1 CH2 H 18 0 0 0 1

Note: B- -CH2-CHOH-CH2-NH (CH2) 2-COOH

Table 3. Compounds of formula III

mark

Formula

mark

Formula

SKI

S2,

S3

S4 <^ \ - NH-NH2

CH ₃ O ^ Q ^ -NH-NH 2

^ NH2-C2H5- QyNH

cl

50 S5 α- ^ θ ^ ΝΗ-ΝΗ ² S6 H2NO2S- ^ 0)) - NH-NH 2 55 S7 ΓΟΤΟ1νΗ-ΝΗ2 S8 nQ ^ —nh-nh ₂ 60

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_z CH ₂ -CH _{2 x}

S14 CH1 CH2 -NH-NH2 ^X CH2 -CH2 ^ remains unchanged.

3. The inclusion complex reducing agent has a much better sensitizing effect than the aqueous or alcoholic emulsion, although it produces a smaller veil.

The following embodiments illustrate the process of the present invention.

Example 1

After swelling in 100 ml of water and dissolving 10 g of inert gelatin, 0.035 mol of potassium bromide, 0.01 mol of cadmium chloride and 0.06 pmol of rhodium complex are added, followed by precipitation at 60 ° C with 1.4 ml of silver nitrate solution. silver halide. After 20 minutes of heat treatment, 40 g of inert gelatin are added and the heat treatment is continued for an additional 80 minutes. The resulting emulsion is cooled to 40 ° C and the casting additives (50 ml 0.05% dye solution, 80 ml 50% glycerol solution, 40 ml 4 t, calculated per mole of silver halide) are added. % saponin solution, 20 ml of 5% form, 35 ml of 1% FMT solution). The emulsion is then loaded on a paper carrier with a silver content of 1.05 ± 0.05 g / m ² . The photographic characteristics of the control material thus obtained are determined according to ISO 6846/1984. Reconstitution at 18 ° C for 2 minutes in the following solution: 1 g of N-methyl-p-aminophenol sulfuric acid salt, 20 g of anhydrous sodium sulphite, 4 g of hydroquinone, 10 g of anhydrous sodium carbonate, 1 g of potassium bromide 1 liter of water.

The inclusion complex solution was flushed into the emulsion 15 minutes after the second gelatin was added. An aqueous or alcoholic solution of the hydrazine derivative is added at the same site. optionally, each of the chemical sensitizers, in the order indicated.

Test substances: inclusion complexes of cyclodextrin monomers. They are denoted here, and later, by the components. The results obtained a

Table 4 shows.

Table 4

Complex sign [CD] [S] Reducing agent ada- align it pmol / mol Average- gradient Photographic features Relative sensitivity kenység Veil 18 ' 2 ' 30 ' 10 ' control - 1.58 100 0.02 0.12 Sl (aqueous) - 48 1.13 108 0.05 0.15 Ml / Sl 40 48 1.51 158 0.02 0.10 M2 / S1 40 48 1.43 145 0.02 0.10 M3 / S1 40 48 1.61 175 0.03 0.09 M4 / S1 40 48 1.39 140 0.02 0.08 M5 / S1 40 48 1.62 185 0.03 0.10

The results show that the inclusion of cyclohextrin monomers in inclusions with phenylhydrazine results in a 40-85% increase in sensitivity without veil growth. The uncomplexed sensitizer caused a lower gradient and sensitivity and a larger veil.

Example 2

All of the procedures described in Example 1 were followed except that inclusion complexes of P1 polymer with various hydrazine derivatives were added to the emulsion in varying amounts and molar ratios. The results are shown in Table 5.

The results show that the hydrazine derivatives administered in the form of inclusion complexes exhibited higher sensitivity than aqueous or alcoholic solutions, respectively.

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Table 5

Complex sign [CD] [S] Addition of reducing agent pmol / mol Average- gradient Photographic features Relative sensitivity kenység Veil 18 ° 2 ' o o control - 1.58 100 0.02 0.12 SKI* 48 1.17 145 0.05 0.18 SKI** - 48 1.13 95 0.05 0.16 S2 *** - 48 1.26 100 0.05 0.10 S3 * - 480 1.30 106 0.06 0.18 S4 - 480 1.10 95 0.04 0.09 S5 - 480 1.26 115 0.04 0.10 S6 48 1.11 91 0.03 0.08 S7 - 48 1.26 130 0.06 0.16 S9 - 48 1.19 140 0.04 0.15 Sll - 48 1.29 125 0.04 0.14 Eg / SI 50 48 1.33 219 0.05 0.14 P1 / S2 50 48 1.20 105 0.05 0.12 P1 / S3 50 480 1.61 165 0.04 0.10 P1 / S4 50 480 1.56 110 0.03 0.10 P1 / S5 50 480 1.75 152 0.03 0.12 P1 / S6 50 24 1.28 200 0.06 0.22 P1 / S7 50 72 1.30 190 0.06 0.15 P1 / S9 50 48 1.40 180 0.03 0.12 Eg / SII 50 48 1.43 140 0.03 0.10 Eg / SI 5 48 1.40 200 0.05 0.09 5 96 1.39 185 0.05 0.10 5 144 1.36 167 0.06 0.12 5 192 1.28 150 0.06 0.14 Eg / SI 75 48 1.25 140 0.04 0.10 50 48 1.33 219 0.05 0.14 25 48 1.42 202 0.04 0.12 15 48 1.35 198 0.04 0.12 10 48 1.26 196 0.04 0.08 5 48 1.40 200 0.05 0.09

Note: *) ethanol solution, **) aqueous solution, ***) S4-S11 aqueous solution

Example 3 Various inclusion complexes were added to the emulsion. The results are shown in Table 6.

with the difference that phenylhydrazine and 2-quinolylhydrazine

Table 6

Complex [CD] reducing Average- Photographic features sign [S] times ada- Relative Veil align it gradient feel 18 ' 30 ° pmol / mol comfort 2 ' 10 '

P1 / S7 50 48 1.22 176 0.04 0.14 P2 / S7 50 48 1.32 121 0.06 0.14 P3 / S7 50 • 48 1.31 102 0.05 0.15 P4 / S7 50 48 1.06 95 0.05 0.14 P5 / S7 50 48 1.02 86 0.05 0.14 S7 (aqueous) - 48 1.26 130 0.06 0.16 Eg / SI 50 48 1.33 219 0.05 0.14 P2 / S1 50 48 1.35 115 0.05 0.12 P3 / S1 50 48 1.26 126 0.05 0.12

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Complex sign [CD] [S] The reducing agent is added in pmoles / mol Average- gradient Photographic features Relative detected kenység Veil 18 ' 2 ' 30 ' 10 ' P4 / S1 50 48 1.22 110 0.06 0.16 P5 / S1 50 48 1.05 175 0.05 0.20 SI (aqueous) - 48 1.16 104 0.05 0.16 control - - 1.58 100 0.02 0.12

As can be seen from the data, the inclusion complexes, depending on the structure of the cyclodextrin polymer and the hydrazine derivative, have different effects on the sensitivity, but in the optimal complex composition both reducing agents are more effective than in aqueous solution alone.

Example 4

All proceed as in Example 1, except that only 0.01 mol of cadmium chloride is added to the inhaled gelatin solution, and 60-60 ml of 1.4 M AgNO3 is added. Precipitate the silver halide with KBr solution; as a sensitizer, complexes of the P4 polymer with various hydrazine derivatives are used, and color-sensitized with dye IV. The results are shown in Table 7.

Table 7

Complex sign [CD] [S] The reducing agent is added in pmoles / mol Average- gradient Photographic features Relative detected kenység Veil 18 ' 2 ' 30 ' 10 ' control - 1.35 100 0.08 0.18 P4 / S1 25 48 1.40 215 0.07 0.15 P4 / S2 25 48 1.20 122 0.05 0.15 P4 / S8 25 48 1.26 280 0.09 0.25 P4 / S10 25 48 1.29 160 0.10 0.19 P4 / S12 25 48 1.36 127 0.05 0.13 P4 / S13 25 48 1.26 148 0.04 0.12 P4 / S14 25 48 1.42 196 0.05 0.18

The data indicate that all inclusion complexes show significant sensitizing effects.

Example 5 Na ₂ S ₂ O _{3 -} 48 pmol / mol (S); NH ₄ Au (SNC) ₂ = 55

All were carried out as in Example 1, with pmol / mol (AU); K ₂ PdCl _{6 -} 60 pmol / mole (PD).

with the difference that the Pl / Sl inclusion complex has a molar ratio of [CD] / [S] = 50 in the 45 A inclusion complex. Sulfur + gold, respectively. Combined results with sulfur + palladium sensitization are shown in Table 8. náljuk. Dosages: Pl / Sl-48 pmol / mol (R);

Table 8

Row- song Order of sensitization dosing Average gradient Reletív sensitivity kenység Veil Comment 18 ' 2 ' 30 ' 10 ' First control 1.58 100 0.06 0.12 No sensitizers Second R 1.33 219 0.05 0.14 Third S + U 1.86 377 0.0? 0.18 4th R + S + U 2.05 720 0.08 0.36 5th R + S + U 1.76 550 0.10 0.52 S1 in aqueous solution

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Row- song Order of sensitization dosing Average gradient Reletív sensitivity kenység Veil Comment 18 ' 2 ' 30 ' 10 ' 6th S + Au + R 1.66 940 0.09 0.44 7th S + Au + R 1.53 690 0.11 0.46 8th R + S + U 1.29 530 0.09 0.40 Ski dosing before impact 9th R + S + PD 1.92 686 0.06 0.32

The results show that the inclusion complex of the reducing sensitizer can be well combined with other sensitizing agents and has a higher gradation and sensitivity compared to the reducing agent used in aqueous solution only. creates a smaller veil value. It can also be seen that phenylhydrazine in the inclusion complex has a synergistic effect with sulfur + gold sensitizers, but the reducing agent used in aqueous solution alone does not. (See the sensitivity data in rows 4 and 5 of the table for the sum of the sensitivities obtained in Experiments 2 and 3.)

PATENT CLAIMS

Claims (4)

PATENT CLAIMS A process for reducing the sensitization of silver halide photographic emulsions, optionally in combination with other sensitization, by precipitating the silver halide crystals in a protective colloidal solution, increasing them to the required size, optionally removing excess ions, characterized in that ) from a cyclodextrin of general formula - in the formula A group derived from the removal of k hydroxyl groups from CD ¹ α, β or γ-cyclodextrin R ^{1 is} hydrogen, or R is COOH, R is SO ³ H, R "NH2 - wherein R" is a linear or branched alkylene group having 1 to 5 carbon atoms, k being an integer from 1 to 5, or a cyclodextrin polymer of formula II having from 30 to 70% by weight of a cyclodextrin having an average molecular weight of 2000-15000 , - in the formula CD ² and CD represents the α- and β- or γ-cyclodextrin molecule and p + 1 + t + r hydroxyl group derived by removal of ^two CD case, R and R 'are independently -CH 2 -, -CHOH-CH 2 -, -CH ₂ -O- (CH 2) 2 -O-CH ₂ CHOH-CH ₂ -CH ₂ -O-CH ₂ CHOH-CH _{2 -} , or -CH ₂ O (CH 2) 4 -O-CH ₂ -CHOH-CH ₂ -. group of formula X is -OR ¹ , or -O-R ^2, or -NR ^ ^{5 in} which R ¹ is hydrogen or, when different from r ^{0, it} is a derivative of the α-, β- or γ-cyclodextrin which can be derived from a hydroxyl group, R ² is hydrogen, -PO (OH) 2, or 8 R ⁴ and R ⁵ m and nr P s and t 35 ^u CD ² and CD CD and CD CD ² and CD 50 Rs R ⁹ and R ¹⁰ Represented when R-SO2OH formula R ³ - (COOH) _u, -R ³ -SO2OH, -R ⁴ NR ³ R ⁴ R ⁵ radical, or a α-, β- or γ-cyclodextrin molecule by removing a hydroxy group derived from , the same as R ² , other than the above derivative of a cyclodextrin, represents a u + 1-valent C 1 -C 10 alkali derivative which may be optionally substituted with oxo, independently hydrogen or C 1 -C 4; alkyl is independently an integer from 1 to 10, An integer from 0 to 23, An integer from 1 to 24, independently an integer from 0 to 7, and Represents an integer from 1 to 5, with the proviso that m, n, r, t and u may vary within a unit, side-by-side, and if a group derived from α-cyclodextrin, p + s 18 and r + t 17, and if p is a derivative of β-cyclodextrin, then p + s 21 and r + t 20; and if a derivative of γ-cyclodextrin, p + s 24 and r + t 23; a quinolyl, pyridyl or cyclohexyl group or a group of the general formula (a), (b), (c), (d), (e), (f), (g) or (h), hydrogen, phenyl, hydrogen , halogen, C 1-4 alkyl or alkoxy or sulfonamido, hydrogen or halogen, The C 1 -C 4 alkyl or alkoxy group is incorporated into the photographic emulsion in an amount of 10-500 pmol / mole, preferably 25-100 pmol / mole, of silver halide per reducing agent, while the inclusion complex-81 The CD monomers at 120 Β have a Q- [CD] / [S] molar ratio of sensitizing compound of from 4: 1 to 80: 1, preferably from 10: 1 to 50: 1. 2. The method of claim 1, wherein the reduction sensitization is combined with sulfur and gold sensitization while the inclusion complex can be administered before, between or after the sulfur and gold compounds. The process of claim 1, wherein the reduction sensitization is sulfur sensitization and the periodic table is VHI. column, preferably Irish, Pt, Pd, Ru, while the inclusion complex is characterized by sulfur and Vm. may be administered before, between, or after the administration of a compound containing a column element. 4. A process as claimed in any one of claims 1 to 4, characterized in that the inclusion complex of the reduction sensitizer is preceded by the crystallization of silver halide crystals during the crystal growth stage, or