SU857917A1 - Method of preparation gelatin photographic emulsion to casting - Google Patents

Description

(54) METHOD OF PREPARATION OF GELATINOUS PHOTOGRAPHIC EMULSION FOR WATERING

one

The invention relates to methods for preparing a gelatin photographic emulsion for irrigation and can be used in the manufacture of cinema photographs.

A known method of preparing a gelatin photographic emulsion for irrigation consists in introducing into the emulsion a viscosity regulator — a mixture of formalin and phloroglucin (1: 3) l.

The disadvantage of this method is that the introduction of these substances in a low-gelatin photo emulsion (4-5%) allows the viscosity of the latter to be increased only to a viscosity corresponding to an emulsion containing 7-13% gelatin.

In addition, a mixture of formalin and phloroglucine is photographically active; on. Formalin causes veil growth

BUT

WITH

-sn -snh 050 jNa rs osnn / Z1 he

where X is 9.65-39%; V 37-66.5%;

 3.19-38.1%, in the amount of 1-20% by weight of dry gelatin.

in emulsion s and has limited. use even as a tanning agent in the manufacture of film photographic materials. The use of a known mixture in photoemulsions causes the rapid appearance of red staining at pH 6 and precipitation of flocculent precipitate due to the polymerization of the starting components.

The purpose of the invention is to reduce the consumption of gelatin.

The goal is achieved by the fact that according to the method of preparing a gelatin photographic emulsion for irrigation, which involves introducing a viscosity regulator into the emulsion, the viscosity regulator uses a mixed ester of polyvinyl alcohol, sulfuric and cinnamic acids of the general formula

(one)

Example 1. K432ML pyridine, cooled to, slowly 30. 29.5 ml (6.45 gmol) are added dropwise.

lorsulfonic acid. The reaction assembly is heated to and, at this temperature, 26.4 g (0.6 g, -1 mole) of polyvinyl alcohol is added in portions. The mass is heated in a boiling water bath for 1 h. At the end of the exposure, the contents of the flask are cooled to 45-50 s and at this temperature 74.7 g (0.45 g-mol) of cinnamic acid chloride are quickly charged. The reaction mass is heated to 100 ° C and allowed to hold for 1 hour. At the end of the exposure, the mass is cooled to, the upper pyridine layer is decanted, and the remaining polymer is dissolved by adding water in an amount equal to the volume of pyridine fused, tlaccy is stirred until complete dissolution and filtered through the bz filter.

The filtrate is adjusted with a 40% aqueous solution of caustic soda to a slightly alkaline reaction to brilliant yellow, maintaining the temperature of the reaction mass equal to 20 ° C.

The resulting solution was added to 2000 ml of methanol. The methanol after decantation of the polymer is decanted. 2000 ml of fresh methanol is added to the polymer, which after stirring for 1 hour is decanted, and the precipitate is poured with 2000 ml of acetone and stirred for 1 hour. The precipitate is filtered and dried at 20 ° C.

Similarly to the described, other mixed esters of polyvinyl alcohol, sulfuric and cinnamic acids are obtained by changing the ratio of initial reagents.

Table 1 shows the characteristics of mixed esters of polyvinyl alcohol, sulfuric and cinnamic acids, obtained at different ratios of the initial reagents.

I Table 1

Example 2. To the aqueous solution of gelatin at 40 ° C and pH b ± 0.5 is added with stirring a 10% aqueous solution of mixed ester of polyvinyl alcohol, sulfuric and cinnamic

ABOUT

0.1 0.2

famous

1.6

ABOUT

15

ten

20 o

acids in the amount of 1-20% (by weight of air-dry gelatin).

Tables 2 and 3 show the viscosity of gelatin solutions containing various amounts of viscosity regulators. table 2

Coagulates

4.7

8.1 23.5

26.1

25.1, 4.7

7.0

6.3

I I

 Contains 0.2 g of formalin in 1000 ml. 5% gelatin solution.

 Corresponds to 80 ml of a mixture of 1% solution of formalin and phloroglucin in the ratio of 1: 3.

 other compounds obtained similar results.

8579176

Continued table. 2

28

36.0

Table 3 Example Z.To a negative bromine of an olfactory emulsion with a pH of 6.5 ± 0.5 pBr of 2.2-2.3 was added with stirring a 10% aqueous solution of mixed ester of polyvinyl alcohol, sulfuric and cinnamon acid in an amount 1-20% (by weight of air dry gelatin). Table 4 shows the viscosity of a negative bromide-silver emulsion containing various amounts of compound I I. Table 4

Thus, the viscosity of 5% gelatin solutions containing up to 20% polymer by weight of dry gelatin; increases from 4.4 to 393 Cp, i.e. 89 times; and 1% aqueous solution of platinum with the same ratios - 58 times. In the process of setting at 40 ° C, the viscosity does not change.

When applying a viscosity regulator, a mixture of formalin and phloroglucin (1: 3). already at a mixture concentration of 1.6%, gelatins coagulate., with the use of smaller amounts, the viscosity increases slightly. The proposed viscosity regulator can use 1% solution. Gelatin solutions, instead of 4-5% solutions, are used according to a known method, with

/ -СНг-СНЛ АсНд-рН- N AcНg-СНV he / X ООЛМАЛ OCQ

this achieves the same value in the list. This allows, using the proposed method, to reduce the consumption of gelatins by 5 times compared with the known method.

Claims (1)

1. USSR author's certificate 1 77060, cl. 6 03 C 1/06, 1948 (prototype)