DE1547756A1 - Use of sulfonium salts as hardening agents to harden the binder of photographic materials - Google Patents

Description

PATENTANWÄLTE 25/65/77 J! DR.-.NG. WOLFF, H. BARTELS, ⁸ ^ SSSSL ^ ^ DR. BRANDES, DR.-ING. HELD phone = (oeii) 293297

Reg. No. 120

Eastman Kodak Company, 3 ^ 3 State Street, Rochester, New York State, United States of America

Use of sulfonium salts as hardening agents to harden the binder of photographic materials

For hardening the binder, in particular the gelatin of photographic materials, for example for hardening of the gelatin of silver halide photographic emulsions, various hardening agents have been proposed been. It has been found, however, that the known hardening agents often reduce the properties of photographic properties Adversely affecting materials, either immediately after the addition of the curing agent or after the photographic materials have been stored for a long time.

The invention was based on the surprising finding

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J 547756

that sulfonium salts with 2 or more sulfate ester groups,

to

each in the β-position in a sulfonium salt group are excellent hardeners for binders for photographic materials.

Accordingly, the invention relates to the use of sulfonium salts with at least 2 sulfate ester groups,

to
each in the ß-position hm a sulfonium salt group

fe are located as a hardening agent for hardening the binder photographic materials.

The invention was based on the knowledge that the invention sulfonium salts used are not only excellent hardening agents but also have the effect of antifoggants can exercise. The ß-sulfatoalkylsulfonium salts used according to the invention influence the sensitometric properties of photographic materials neither shortly after addition nor after prolonged storage of the photographic material negative.

The sulfonium salts used according to the invention can be generally used for hardening photographic layers

^co , whose binding agents are active groups, such as belspielso

^ wise free amino groups. The most famous ver

- ^ - A member of this group is gelatine. When using

ο The binder not only needs gelatine as a binder

* ° to consist of gelatin. Rather, such photo-

graphic layers are hardened, the binders of which consist partly of / gelatin different binders.

The sulfonium salts used according to the invention are of particular importance for hardening the gelatin of photographic silver halide emulsion layers.

Is the binder of the silver halide emulsion layers partially composed of a binder or carrier other than gelatin, then this binder or carrier consist of one of the usual binders or carriers, those used for the production of photographic silver halide modules sions can be used. Examples include polyvinyl alcohol and copolymers of alkyl acrylates and acrylic acid, such as, for example, copolymers of ethyl acrylate and acrylic acid or butyl acrylate and acrylic acid and the like, as well as a wide variety of others Polymers made from vinyl or acrylic compounds, such as those used for the production of photographic emulsion layers will.

Quite generally, the sulfonium salts used according to the invention are effective hardeners for such polymers Binders having hydrophilic groups, d. H. Hydroxyl groups and carboxyl groups.

If appropriate, the sulfonium salts used according to the invention can also be used for hardening those layers of photographic materials whose binders are intact from a binding agent other than gelatine «it hydro-" 909847/0793

philic remains.

The use of sulfonium salts of the following structural formula has proven to be particularly advantageous;

9 9 Ί f π 2 2 3

R R

where mean:

η «0 or 1;

R is an alkyl radical having 1 to 6 carbon atoms or a radical of the formula: -CH ₂ CH ₂ OSO ₃ M;

Q is an alkylene radical with 1-10 carbon atoms, which can optionally have unsaturated groups or have a phenylene radical can or a cycloalkylene radical or a heteroatom;

M is an alkali or alkaline earth metal atom or an ammonium group and

X is an anion, for example a halogen anion, such as, for example, a chlorine anion or an anion of the formula R ¹ SO ₃ or the like, in which R 'has the meaning of an alkyl or aryl radical.

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The sulfonium salts which can be used according to the invention include also so-called compounds consisting of zwitterions, which differ from the compounds described by deduction differ from one or more equivalents MX and as disalts of an inner tris (ß-sulfatoalkyl) sulfonium salt can be designated.

The sulfonium salts used according to the invention are preferred used in concentrations of 0.5 to 5 wt .- $, based on the weight of the gelatin to be hardened.

The use of the disodium salt has proven to be particularly advantageous of the inner tris (ß-sulfatoethyl) sulfonium salt proved.

The following examples are intended to illustrate the invention in more detail:

example 1

A highly sensitive silver bromoiodide emulsion which had been panchromatically sensitized by the addition of a cyanine dye was divided into 3 parts. Different concentrations of the disodium salt of the inner tris (ß-sulfoethyl) sulfonium salt of the following structural formula were added to two portions:
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S (CH ₂ CH ₂ OSO ₃ Na) ₂

I Q

The various emulsion samples were placed on cellulose

Acetate film carrier applied in such a way that on a carrier area of 0.0929 m ² (1 squ;
1040 mg of gelatine were omitted.

area of 0.0929 m (1 square foot) 459 mg of silver and

Samples of the films obtained were then exposed in an Eastman 1B sensitometer, whereupon the exposed Samples were developed for 5 minutes in a developer of the following composition:

Water, about 50 ° C 500 ml

p-methylaminophenol sulfate 2.5 g

Sodium sulphite, dehydrated ...,. 30.0 g

Hydroquinone 2.5 g

Alkali 10.0 g

Potassium bromide. 0.5 g

made up to 1.0 liter with water

The exposed samples were then used in a known manner fixed, washed and dried. It became the following

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Get results:

g hardener per 100 g of gelatin

fresh material

Material incubated for 1 week at 49 ° C

I swell in water

ReI. γ sensitivity

Schlei- ReI. γ veil sensation opportunity

1 3

100 1.25 0.13

100 1.32 0.13

95 1.32 0.11

60 0.97 0.38 48 0.75 0.26 52 0.75 0.15

750 490 320

The percentage swelling in water was determined by immersing strips of the obtained photographic material in distilled water at 20 ⁰ C. The Sttrke of the photographic material before immersion in the distilled water, and after removal of the distilled water was measured.

The results obtained clearly show the effectiveness of the sulfonium salt as an antifoggant and also the effectiveness of the sulfonium salt as a hardening agent.

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Example 2

A highly sensitive silver halide emulsion layer was prepared, the binder for the silver halide of which consisted of a mixture which was 25 liters composed of gelatin and 751 of the sodium salt of a copolymer of ethyl acrylate and acrylic acid. The silver halide emulsion was divided into two portions. 5 parts by weight of the disodium salt of the inner tris (β-sulfatoethyl) sulfonium salt per 100 parts by weight of binder were added to one portion.

The two portions of the emulsion were then coated onto clear cellulose acetate film backing such that 750 mg of emulsion was ^{applied to a 0.0929 m 2 (1 square foot) backing area.}

The vertical swelling of the photographic materials obtained was determined at 25 ^° C. in water and in a developer solution of the specified composition. The following results were obtained:

g hardener per liter of vertical swelling at 25 ^° C. g binder developer H ₂ O

approx. 1200 is washed off 5 450 120

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Claims (1)

P a te nt to s ρ rüche 1, ^ Use of sulfonium salts with at least two sulfate ester groups, each in ß-position to a sulfonium salt group as a hardening agent for hardening the binder of photographic materials, 2, use of sulfonium salts according to claim 1, characterized in that that they correspond to the following formula: MO ^ O CH ₂ CH ₂ -S - (QS) _n CH ₂ CH ₂ OSO ₃ M, (n + 1) Χ ^Θ R R where mean: η ^a 0 or 1; G R is an alkyl radical with 1 to 6 carbon atoms or a radical of the formula: -CH ₂ CH ₂ OSO ₃ M; Q is an alkylene radical having 1 to 10 carbon atoms; M is an alkali or alkaline earth metal atom or a Ammonium group and
X is an anion. 909847/0793 3. Use of sulfonium salts according to claims 1 and 2, characterized in that it is one of de »Disalz inner tris (ß-sul £ atoalkyl) sul £ onium salt. 4. Use of sulfonium salts according to Claims 1 to 3, characterized in that they consist of the disodium salt of the inner tris (ß-sul £ atoethyl) sulfonium salt. 5. Use of sulfonium salts according to Claims 1 to 4, characterized in that it is used for hardening the gelatin of gelatin-containing silver halide emulsion layers. 909847/0793