DE2012095C3 - Silver halide photographic emulsion - Google Patents

Description

Acrylamide,

N-methyl acrylamide,

Ν, Ν-dimethylacrylamide,

Ν, Ν-diethylacrylamide,

N-ethyl acrylamide, N-hydroxyethyl acrylamide, N-hydroxyethyl-N-methyiacrylamide,

a-acetamide acrylamide,

a-methylacrylamide (methacrylamide),

Ν, Ν-dimethyl methacrylamide,

Ν, Ν-diethyl methacrylamide,

N-methyl methacrylamide, N-ethyl acrylamide, N-hydroxyethyl-N-methyl methacrylamide, N-methoxymethacrylamide, N-acetamide acrylamide, N-methylolacrylamide, N-methylol methacrylamide or ⁴ ' N-acetamide methacrylamide

was used.

4. silver halide emulsion according to claim 1 to 3, characterized in that as Monomerekom- ', 0 component C)

I vinyl-2-methylimidazole,

1-vinyl-2-ethylimidazole,

I - vinyl-2,4-dimethylimidazole,

l-vinyl-2-ethyl-4-methylimidazole,

l-vinyl-4 (5) - ^ - hydro) tyäthylimidazol,

1 - vinyl-2-hydroxyethylimidazole or

5-vinylimidazole

was used. mi

20th

25th

30th

35

40

The invention relates to a photographic silver halide emulsion which contains an amphoteric binder as a binder Contains interpolymer, which by interpolymerization of the monomer component A), consisting of one containing carboxyl or sulfonic acid groups Vinyl compound with the exception of acrylic acid and Derivatives thereof, with the monomer component B), consisting of acrylamide or derivatives thereof was produced.

From "Journal of Japan Photographic Society", Volume 29, No. 1, page 30, only a copolymer is made Acrylamide, acrylic acid and vinylimidazole derivative known, which have a similar protective effect as Has gelatin

DE-PS 4 45 733 describes a process for the preparation of photosensitive silver salt emulsions in which imidazole or derivatives thereof to a silver halide emulsion before or during its preparation or before application added to the emulsion, gelatin being used as a protective colloid.

DE-PS 12 02 132 describes a process for the production of photographic silver halide emulsions in which a synthetic high molecular weight material containing amide, ester and acidic groups is used as a protective colloid.

Finally, from US-PS 34 49 123 a photographic layer, for. B. a silver halide emulsion layer is known in which a vinylmethylimidazole homopolymer and / or copolymer is incorporated. This addition is used to prevent Color opacities only in color photography.

In contrast, the object of the invention is to provide a photographic silver halide emulsion in which the growth rate of the silver halide crystals as with gelatin is increased by means of a more amorphous copolymer as its binder can be controlled, however, the disadvantages of gelatin, namely mold, rot or Decomposition is avoided, but at the same time an excellent protective colloid effect and constant quality of the emulsions is achieved.

This object is achieved in that the copolymer additionally contains 3.8 to less than 10 mol% of a copolymerized monomer component Q, consisting of vinylimidazole or derivatives thereof, the content of monomer component A) from 5 to less than 20 mol% and the Content of monomer component B) is over 70 to 91.2 mol%.

The invention thus provides a silver halide photographic emulsion in which an amphoteric Copolymer which contains an acidic and a basic group and additionally copolymerized vinylimidazole or derivatives thereof in the same molecule, is used as a protective colloid for the silver halide. The invention thus differs in respect of that Task and guidance of the process according to DE-PS 4 45 753, according to the imidazole or derivatives of which can only be used in a low molecular weight state.

That in the process according to DE-PS 12 02 132 The synthetic high molecular weight material used contains only acidic and neutral, but not basic Groups of which the latter are known to have a strong affinity for silver halide, The The absorption power to silver halide is therefore only weak there and it is therefore not so good Properties as a protective colloid as in the amphoteric copolymer used according to the invention achieved.

The high molecular weight copolymer used according to the invention is therefore a basic group

essential for absorption as a protective colloid on the Silver halide responsible, while the acidic groups to a certain extent have a control function over the Exercise the effect of the basic group. In this way, the absorption properties and thus the protective properties against silver halide can be freely regulated by the ratio of the basic groups changed accordingly to the acidic groups within the specified limits In addition, the isoelectric point can be far Area, depending on the relationship between the two groups, can be freely chosen. In this way, the Conditions for the preparation of the silver halide emulsion (e.g. pH value or ion concentration) in vary over a wide range. In addition, the copolymer used according to the invention has excellent properties Properties in controlling the growth rate of silver halide crystals on. This is largely due to the absorbency of the vinylimidazole on the silver halide. In contrast, it is already theoretically clear that one can use one as an additive for photographic Synthetic copolymer known as silver halide emulsions which does not contain any basic groups, cannot achieve these excellent effects and advantages. This also applies to prevention homo- and / or copolymers used to reduce color cloudiness U.S. Patent 3,449,123.

The interpolymerization of the three monomer components can be carried out in a known manner using of e.g. persulfates or hydrogen peroxide as starter substances.

Typical examples of the monomer component A) are p-styrene sulfonic acid, V ^: nylsulfonic acid, maleic acid, fumaric acid, itaconic acid, C-stonic acid and p-styrene carboxylic acid.

Examples of the monomer component B) are

Acrylamide,

N-methyl acrylamide,

N ₁ N-dimethylacrylamide,

Ν, Ν- diethyl acrylamide,

N-ethyl acrylamide,

N-hydroxyethyl acrylamide,

N-hydroxyethyl-N-methylacrylamide,

Λ-acetamide acrylamide,

«-Methylacrylamide (methacrylamide),

Ν, Ν-dimethyl methacrylamide,

Ν, Ν-diethyl methacrylamide,

N-methyl methacrylamide,

N-ethyl acrylamide,

N-hydroxyethyl N-methyl methacrylamide,

N-methoxymethacrylamide,

N-acetamide acrylamide,

N-methylolacrylamide,

N-methylol methacrylamide and

N- acetamide methacrylamide.

Examples of the monomer component C) are

I - vinyl-2-methylimidazole,

I - vinyl-2-ethylimidazole,

1 - vinyl-2,4-dimethylimidazole,

l-vinyl-2-ethyl-4-methylimidazole,

l-vinyl-4- (5) -jS-hydroxyethylimidazole,

1 -Vinyl-2-hydroxyethylimidazole and

5-vinylimidazole.

Of the three monomer components, acrylamides or derivatives thereof impart to the obtained one Copolymer good hydrophilic properties and protective colloid effect and the vinylimidazoles or Derivatives thereof have the effect of strongly suppressing the growth of the silver halide crystals. Carboxyl and sulfonic acid groups counteract the growth inhibiting Effect of the imidazole groups. For this reason, the effect of the copolymer on the growth rate of the light-sensitive silver halide crystals by appropriate selection

ίο the proportions of the three components influenced will. In this way, one can determine the crystal growth rate of the silver halide emulsion set to the same value as when using gelatine. You can also change the amount of Imidazoles increase or decrease the amount of acid groups to prevent crystal growth Increase impact; on the other hand, you can increase the amount of acid groups or the amount of Decrease imidazole to reduce its growth-preventing effect.

The content of copolymer in the emulsion should preferably be less than 40% by weight, based on the Total binder weight.

The copolymer has a good affinity for gelatin and for this reason the silver halide emulsion according to the invention also contain gelatin as a binder at the same time.

In order to have adverse photographic properties, such as e.g. B. to prevent fogging in the emulsion, soft are caused by the peroxides used as starter substance, one can use a aromatic amino compound or a derivative thereof represented by the following general formula is expedient Use when starting the copolymerization:

R ²

^l -N

In the above formula, R ^{1 represents} an aryl group which may be substituted by alkyl or alkoxy groups or halogen atoms, and R ² and R ³ each represent hydrogen atoms or alkyl or hydroxyalkyl groups. As a special connection z. B. aniline, monomethylaniline, dimethylaniline, monoethylaniline, diethylaniline, toluidine, anisidine, D \ -ß- hydroxyethylaniline and 0-naphthylamine. Furthermore, a peroxide-catalyzed radical polymerization can be terminated in a certain stage by adding these compounds.

The amount of these compounds to be added is not particularly critical; it is preferably used but in an amount equivalent to the starter substance, since there is none when a smaller amount is used sufficient effect is obtained and disadvantageous photographic properties remain in some cases. On the other hand, when the amount of the amino compound exceeds that of the starter substance, it is observed there are generally no significant adverse photographic properties, but increased Coloring on. The effect of adding this compound is greatest when it is used directly after the end of the polymerization is added, the amount required also being the lowest. the Conversion by which the disadvantageous photographic properties are eliminated does not proceed

momentarily, but requires a certain amount of time. These However, time can be shortened by heating.

The invention will now be explained further with reference to the following examples, but for the Production of the copolymers does not require protection.

Example 2
(1) Production of the copolymer

It became the following two. Solutions made:

example 1
(1) Production of the copolymer

The following two solutions were made:

IO

Solution I: 63.8 g Acrylamide 5.4 g 1 -VinyI-2-methylimidazo! 5.4 g Vinyl sulfonic acid 4.5 g 70% aqueous nitric acid solution 70 ml water Solution II: 348 ml water 0.4 g Ammonium persulfate

25th

Solution A: (60 ° C) 40 g lO ^ bige aqueous solution of the llOgml Mixed polymer ig water ig Citric acid 6 η caustic soda 10g Solution B: (60 ° C) 50 ml Silver nitrate Distilled water 2g Lead nitrate (5% aqueous Solution) 4.5 g Solution C: (50 ° C) 34 g Sodium chloride Potassium chloride 10g Cadmium chloride (10% aqueous 50mi Solution) water

Solution B was added to solution A over one minute while stirring, and solution C then added over a further minute. Thereafter, the resulting emulsion was 55 minutes Digested at 60 ° C for a long time. In addition, 5 ml of a 1% strength potassium chloride solution and 5 ml of a 0.01% strength Sodium thiosulfate solution was added and the emulsion was digested for 20 minutes with a Mr Magnifying papip.re suitable emulsion was obtained.

Solution I:

Acrylamide
5-vinylimidazole
Potassium p-styrene sulfonate
water

Solution II:

water

Ammonium persulfate

63.8 g
4.9 g

11.1 g
79.6 ml

375 ml
0.4 g

30th

Solution II was ^{heated to 90 °} C. in a stream of nitrogen and solution I was then added dropwise to it over the course of one hour. The combined solutions were then ^{heated to 90 °} C. for a further hour, cooled and added to five times the amount of methanol, the copolymer precipitating . It was dried after being separated

(2) Preparation of Photosensitive Emulsion The following three solutions were prepared:

40

The solution II was ^{heated to 90 0} C and the solution; I added dropwise to it over the course of an hour. The combined solutions were πι. Heated to 90 ° C. for one hour, cooled and the misehp mymerizate was precipitated by adding 5 times the amount of methanol. It was dried after separation

(2) Preparation of the photosensitive emulsion

A 10% strength aqueous solution of the copolymer was prepared according to that described in Example 1 Method used to obtain an emulsion suitable for enlargement purposes.

Example 3

The polymerization of Example 1 was repeated, except that 0.25 g of diethylaniline to 1 hour at 90 ° C heated solution was added and the solution was then heated for a further half hour at 70 ⁰ C. Then, cooled, methanol was added and the precipitated mixed polymer was separated off. This mixed polymer used in a light-sensitive emulsion did not cause any fogging possible due to residual starter substance.

Example 4

The polymerization process according to Example 2 was repeated, except that 03 g of dimethylaniline were added to the solution heated ^{to 90 ° C. for 1 hour;} the mixture was then ^{heated to 70 °} C. for 30 minutes, cooled and precipitated with methanol. This product obtained in this way also did not cause fogging when used in a photosensitive emulsion

Example 5

(1) Production of the copolymer
The following solution was made:

Acrylamio 53.2 g

Ethyl 1-vinylimidazole 6.2 g

Fumaric acid 23.2 g

Dimethylformamide 327.3 g

Benzoyl peroxide 0.5 g

The above solution was heated in a nitrogen atmosphere at 70 ⁰ C for 7 hours, thereby precipitating the resulting copolymer with acetone and eetrocknet after separation.

(2) Preparation of the photosensitive emulsion

The following three solutions A, B and C were made:

Solution A: (50 ⁰ C) 10% aqueous solution of the

Copolymer water
Citric acid 6 η sodium hydroxide solution

Solution B: (50 ° C) silver nitrate distilled water lead nitrate (50% aqueous Solution)

Solution C: (50 ° C)

Sodium chloride

Cadmium chloride

water

4.5 g

2.5 g

50 ml

Solution B became solution A with stirring

40 g added over the course of one minute and solution C

110ml then added over a further minute

1 g ίο The resulting emulsion was 35 minutes

Digested Ig 5O ⁰ C. Then she was given 5 ml of 10% potassium jo

did solution was added and it continued for another 20 minutes

digested, one suitable for contact printing!

10 g of emulsion was obtained.

50 ml π The ampho

Other copolymers can of course also be used for color emulsions.

Claims (3)

Patent claims: 1. Photographic silver halide emulsion containing an amphoteric copolymer as a binder contains, by copolymerization of the monomer component A), consisting of one Carboxyl or sulfonic acid groups containing vinyl compounds with the exception of acrylic acid and Derivatives thereof, with the monomer component B), consisting of acrylamide or derivatives of this, was produced, characterized in that the copolymer additionally 3.8 to less than 10 mol% of a copolymerized monomer component C), consisting of Vinylimidazole or derivatives thereof, contains the Content of monomer component A) is 5 to less than 20 mol% and the content of monomer component B is over 70 to 91.2 mol%. 2. silver halide emulsion according to claim 1, characterized in that as monomer component A) p-styroisulfonic acid, vinyl sulfonic acid, Maleic acid, fumaric acid, itaconic acid, crotonic acid or p-styrenic acid was used. 3. Silver halide emulsion according to claim 1 or 2, characterized in that as monomer component B)