SU697957A1 - Method of obtaining images on silver halide photographic materials - Google Patents

Description

one

The invention relates to methods of obtaining images on halogen-silver photographic materials and can be used in photography in cases where the sensitivity of photographic materials is not sufficient to perform a particular job, or in cases where there are no conditions for storing highly sensitive photographic materials.

A known method of obtaining images on halogen-silver photographic materials (on nuclear emulsions) consists in heating the photographic material at 50-C for 1-3 days, cooling the material to room temperature, exposing it with some kind of radiation, and chemically-photographing it. .

The disadvantage of this method is the long duration of heating, as well as the low efficiency of the method: when heated for 3 days, the density of traces of charged particles increases by 30–35%.

There is also known a method of obtaining images on halogen-silver photographic materials not sensitized by optical dyes, which consists in heating the photographic material to a temperature of 700 s for 20-40 hours, cooling the material to room temperature, exposing and chemically photographing it.

The disadvantage of this method is the long duration of the process, as well as low efficiency: when warming up photographic materials in the above mode, the sensitivity of photographic material increases by 30-70%.

Another disadvantage is that with this method it is possible to obtain an image only on some insensitive black-and-white photographic materials and nuclear emulsions, since many materials, such as negative and positive, do not withstand long-term heat treatment and veil heavily.

The aim of the invention is to reduce the duration of the process and increase the sensitivity of photographic material.

The goal is achieved by the fact that in the method of obtaining images on halogen-silver photographic materials, not sensitized

Optical dyes, which consist in heating the photographic material, exposing / cooling the material to room temperature and chemical-photographic processing, heat the photographic material to a temperature of 150,200 ° C for 2-3 minutes and expose the material in a heated state.

The proposed method makes it possible to significantly shorten the process time, increase the sensitivity of photographic material by about 15 times and use photographic materials of various types.

A photographic plate, watered with a high-resolution photographic emulsion, is cut into four pieces.

The first part of the photographic plate is exposed to monochromatic light and developed in the usual way (image, sample No. 1).

The second part of the photographic plate is processed according to method 1 (sample No. 2)

The third part of the photographic plate is processed according to method 2 (sample),

The fourth part of the photographic plate is heated to a temperature for 2 minutes, exposed to the same radiation as the control samples.

Then, the heated exposed photoplate is cooled to room temperature and developed in the usual way (sample No. 4).

Fig. 1 shows the density curves of the blackening of the samples for different wavelengths:

curve 1 - control sample, not subjected to processing (sample No. 1);

curve 2 - the sample subjected to processing according to method 2 (sample No. 3);

curve 4 is a sample processed by the proposed method (sample No. 4).

I process two more photoplates in a similar way, but the heating of one of them is carried out to, and the second to 200 ° C. (samples 5 and № 6).

The blackening density curves of samples No. 5 and No. 6 coincide with curve 4.

From the analysis of the curves, it follows that the known methods 1 and 2 (curves 2 and 3) make it possible to increase the sensitivity of the photographic material by no more than 30% to 70%.

The proposed method (curve 4) makes it possible to increase the sensitivity by a factor of 15.

Positive materials, both on glass substrates and on films, after heating at a temperature of 55 s for 2 days and at a temperature of 40 h and show, have a veil 3.

Lig.2 shows the density curves of the blackening of the positive layers for different wavelengths:

curve 1 - control emulsion, not subjected to processing

curve 2 - the same emulsion according to the proposed method.

The known methods can increase the sensitivity of a highly dispersed emulsion of more than 70%. For positive materials, the known methods do not give a positive effect, since a significant veil appears.

The proposed method allows to increase the sensitivity of the positive material by 3 times, and the highly dispersed material, by $ 15 times.

To determine the changes in resolution using the proposed method, the method for determining the microcrystal size distribution curves before and after heating is used, photographs of the crystals are taken in a Hetachi-type electron microscope. The distribution curves are measured on 1000 grains.

Fig. 3 shows the microcrystal size distribution curves for a highly dispersed emulsion (a) and a positive emulsion (b): solid line - control emulsion without treatment; dotted - the same emulsion of the proposed method.

As a result of the tests performed, it was established that the size of the microcrystals of the studied photographic materials does not change when exposed to intensive short-term heating. This result indicates that the resolution of the materials studied does not change when applying the proposed method

Thus, the proposed method can significantly reduce the duration of the process of obtaining images on halogen-silver Photographic materials and significantly increase the sensitivity of the materials, while the image quality and physical and mechanical properties of photographic materials do not deteriorate.

Claims (2)

1. Authors certificate of the USSR 178263, cl. G 03 S 1/02, published. 1963. 2. Recording media for holography. Collection of articles L., 1976, with. 106 (prototype). 225 50 75 500 25 50 75 tOO 25 50 75 500 525 9mg.  . 697957 W 79 a sa w a 7S sa SHLT