Reverse washing developing solution for RDA black and white films

Abstract

The invention discloses an RDA black and white film reverse washing developing solution, which comprises a solution A, a solution B and a bleaching solution, and specifically comprises the following components: the solution A is prepared from 14-16g of hydroquinone and 0.2-1g of phenidone S, and the volume of the solution A is fixed to 100ml with propylene glycol; the solution B is prepared from 14-16 g of borax decahydrate, 17-19 g of boric acid, 98-102 g of anhydrous sodium carbonate, 98-102 g of anhydrous sodium sulfite, 14-16 g of potassium bromide and 9-11 g of potassium thiocyanate, and the volume of the solution B is fixed to 1 L with deionized water; the bleaching solution is prepared from 19-21 g of sodium hexametaphosphate, 1.5-2.5 g of potassium permanganate and 26-28 ml of sulfuric acid, and the volume of the bleaching solution is fixed to 1 L with deionized water. The reverse washing developing solution is designed through a unique formula, the obtained developing solution is good in preservation performance, and the preservation time is prolonged; the bleaching liquid is low in toxicity, so that health hazards and wastewater treatment difficulty are reduced; the obtained developing solution is environment-friendly, and is beneficial to environmental protection and wastewater treatment; and meanwhile, thick emulsion films can be processed, and the film compatibility is high.

Description

Technical Field

[0001] The invention relates to the technical field of photographic film processing, in particular to a RDA black-and-white film reversal processing developer. Background Art

[0002] In the 21st century, with the rapid development of photography culture, retro trends and film photography have become increasingly popular, and reversal films are loved by the majority of players for their strong sense of presence and unique expressiveness. However, color reversal films are too expensive for ordinary players to afford. Therefore, more players are turning to black and white reversal films, which are cheaper and have equally good effects.

[0003] Black and white reversal film is a kind of film that is specially processed through the black and white reversal process, and processed into a positive film with the same brightness and darkness as the actual shooting scene. At present, the black and white reversal process can be summarized into five steps: first development, bleaching, secondary exposure, second development, and cleaning.

[0004] However, the prior art has the following disadvantages:

[0005] 1) Poor preservation of developer: The developer has defects in its structure. The black-and-white reversal developer has a short shelf life and can generally only be stored for about one month after opening.

[0006] 2) High toxicity of bleaching liquid: The main component of traditional bleaching liquid is acidic potassium dichromate solution, which is highly toxic and corrosive, highly carcinogenic, difficult and costly to treat wastewater, and poses a great health hazard to users; and the traditional potassium permanganate formula easily causes the gelatin layer of the film to dissolve and demold, resulting in a low success rate of washing and high requirements for washing equipment;

[0007] 3) The developer is highly polluting: the developer used is metol-hydroquinone, which is a non-environmentally friendly system and is not conducive to environmental protection and wastewater treatment;

[0008] 4) Poor film compatibility: The traditional reversal processing process cannot process thick emulsion films, such as Ilford Formosa 100, FP4+, PanF, etc. This greatly limits the choice and use of different types of films by photography enthusiasts and makes it impossible to give full play to the advantages of the black and white reversal process. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the defects of the above-mentioned technology and provide a RDA black-and-white film reversal washing and developing solution.

[0010] In order to solve the above technical problems, the technical solution provided by the present invention is a RDA black and white film reversal developing solution, comprising liquid A, liquid B and bleaching solution, and the specific composition is as follows:

[0011] The liquid A is prepared by dissolving 14 - 16 g of hydroquinone, 0.2 - 1 g of phenidone S, and making up the volume to 100 ml with propylene glycol;

[0012] The liquid B is prepared by dissolving 14 - 16 g of borax decahydrate, 17 - 19 g of boric acid, 98 - 102 g of anhydrous sodium carbonate, 98 - 102 g of anhydrous sodium sulfite, 14 - 16 g of potassium bromide, 9 - 11 g of potassium thiocyanate, and making up the volume to 1 L with deionized water;

[0013] The bleaching solution is prepared by dissolving 19 - 21 g of sodium hexametaphosphate, 1.5 - 2.5 g of potassium permanganate, 26 - 28 ml of sulfuric acid, and making up the volume to 1 L with deionized water.

[0014] Further, the concentration of the sulfuric acid is 20%.

[0015] Further, the preparation method of the liquid A is as follows: Add an appropriate amount of propylene glycol into a container, heat it to 75 - 80 °C, add hydroquinone and phenidone S, stir until completely dissolved, make up the volume to 100 ml, and then cool it to room temperature to obtain the liquid A.

[0016] Further, the preparation method of the liquid B is as follows: Add an appropriate amount of deionized water at 45 - 50 °C into a container, and dissolve borax decahydrate, boric acid, anhydrous sodium carbonate, anhydrous sodium sulfite, potassium bromide, and potassium thiocyanate in sequence under stirring. After cooling to room temperature, discard the precipitate and the precipitated matter, and take the supernatant to obtain the liquid B.

[0017] Further, the preparation method of the bleaching solution is as follows: Add an appropriate amount of deionized water at 45 - 50 °C into a container, dissolve sodium hexametaphosphate and potassium permanganate in sequence under stirring, then slowly add 27 ml of sulfuric acid with a concentration of 20%, and cool it to room temperature to obtain the bleaching solution.

[0018] The advantages of the present invention compared with the prior art are as follows:

[0019] 1) Good preservation property: Through the unique formulation design of the liquid A and the liquid B, the storage time of the developer is significantly prolonged, and it can be stored for a long time after opening, reducing the trouble of frequent preparation and lowering the usage cost;

[0020] 2) Low toxicity of the bleaching solution: By adopting a new bleaching solution formulation, the use of highly toxic acidic potassium dichromate solution is avoided. At the same time, the usage mode of potassium permanganate is optimized, and components such as sodium hexametaphosphate are added, effectively reducing the adverse effects on the gelatin layer of the film, improving the rinsing success rate, and reducing the harm to the health of users and the difficulty and cost of wastewater treatment;

[0021] 3) Environmentally friendly developer: Hydroquinone and phenidone S are selected as the main developing agents, which is more environmentally friendly than the traditional metol-hydroquinone system, is beneficial to wastewater treatment, and meets the requirements of environmental protection in today's society;

[0022] 4) Strong film compatibility: The developing solution of the present invention can process thick emulsion films, such as Ilford FP100, FP4+, Pan F, etc., greatly broadening the range of films applicable to the black-and-white reversal development process and providing more film choices for photography enthusiasts. Detailed implementation mode

[0023] The following further details an RDA black-and-white film reversal developing solution of the present invention in conjunction with embodiments.

[0024] Embodiment 1

[0025] An RDA black-and-white film reversal developing solution includes liquid A, liquid B, and bleach, wherein:

[0026] Preparation of liquid A: Add an appropriate amount of propylene glycol to a container, heat to 75°C, add 14 g of hydroquinone and 0.4 g of phenidone S, stir until completely dissolved, make up the volume to 100 ml, and then cool to room temperature.

[0027] Preparation of liquid B: Add an appropriate amount of deionized water at 45°C to a container, and successively dissolve 14 g of borax decahydrate, 17 g of boric acid, 98 g of anhydrous sodium carbonate, 98 g of anhydrous sodium sulfite, 14 g of potassium bromide, and 9 g of potassium thiocyanate under stirring. After cooling to room temperature, discard the precipitate and the separated substances, and take the supernatant.

[0028] Preparation of bleach: Add an appropriate amount of deionized water at 45°C to a container, and successively dissolve 19 g of sodium hexametaphosphate and 1.5 g of potassium permanganate under stirring. Then slowly add 26 ml of sulfuric acid with a concentration of 20%, and cool to room temperature.

[0029] Use the above-prepared developing solution to perform reversal development on Ilford FP100 thick emulsion film, and operate according to the conventional black-and-white reversal process steps. The results show that the film developing effect is good, the image is clear, and there is no gelatin layer dissolution and demolding phenomenon on the film. After the developing solution is unsealed and stored, it can still be used to develop the film normally after one month, and the developing effect has no obvious decline.

[0030] Embodiment 2

[0031] An RDA black-and-white film reversal developing solution includes liquid A, liquid B, and bleach, wherein:

[0032] Preparation of liquid A: Add an appropriate amount of propylene glycol to a container, heat to 80°C, add 16 g of hydroquinone and 0.6 g of phenidone S, stir until completely dissolved, make up the volume to 100 ml, and then cool to room temperature.

[0033] Preparation of Solution B: Add appropriate amount of deionized water at 50 °C into a container, and successively dissolve 16 g of borax decahydrate, 19 g of boric acid, 102 g of anhydrous sodium carbonate, 102 g of anhydrous sodium sulfite, 16 g of potassium bromide and 11 g of potassium thiocyanate under stirring. After cooling to room temperature, discard the precipitate and the separated out substances, and take the supernatant.

[0034] Preparation of Bleaching Solution: Add appropriate amount of deionized water at 50 °C into a container, and successively dissolve 21 g of sodium hexametaphosphate and 2.5 g of potassium permanganate under stirring, then slowly add 28 ml of sulfuric acid with a concentration of 20%, and cool to room temperature.

[0035] Use this developing solution to perform reversal rinsing on FP4+ thick emulsion film. After rinsing, the quality of the film is excellent, the color reproduction is accurate, and the contrast is moderate. At the same time, after this developing solution is stored for two months after opening, it can still maintain good developing performance and has little influence on the rinsing effect of the film.

[0036] Example 3

[0037] A reversal developing solution for RDA black-and-white film includes Solution A, Solution B and bleaching solution, wherein:

[0038] Preparation of Solution A: Add appropriate amount of propylene glycol into a container, heat it to 78 °C, add 15 g of hydroquinone and 1 g of phenidone S, stir until completely dissolved, make up the volume to 100 ml and then cool to room temperature.

[0039] Preparation of Solution B: Add appropriate amount of deionized water at 48 °C into a container, and successively dissolve 15 g of borax decahydrate, 18 g of boric acid, 100 g of anhydrous sodium carbonate, 100 g of anhydrous sodium sulfite, 15 g of potassium bromide and 10 g of potassium thiocyanate under stirring. After cooling to room temperature, discard the precipitate and the separated out substances, and take the supernatant.

[0040] Preparation of Bleaching Solution: Add appropriate amount of deionized water at 48 °C into a container, and successively dissolve 20 g of sodium hexametaphosphate and 2 g of potassium permanganate under stirring, then slowly add 27 ml of sulfuric acid with a concentration of 20%, and cool to room temperature.

[0041] Use this developing solution to rinse Pan F thick emulsion film, and satisfactory results are obtained. The details of the film are richly presented, the grains are fine, and during the whole rinsing process, there is no film damage caused by problems of the developing solution or the bleaching solution. After this developing solution is stored for one and a half months after opening and used to rinse the film, it can still meet a high quality standard.

[0042] It can be seen from the above examples that the reversal developing solution for RDA black-and-white film of the present invention has achieved remarkable improvement effects in aspects such as the storage stability of the developing solution, the toxicity of the bleaching solution, the environmental friendliness of the developing solution and the film compatibility, and has good application prospects.

[0043] The above describes the present invention and its implementation manners, and such description is not restrictive. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, creatively design structural manners and embodiments similar to the technical solution, they shall fall within the protection scope of the present invention.

Claims

1. A RDA black and white film reversal developing solution, characterized in that: It includes liquid A, liquid B and bleaching liquid, and the specific composition is as follows: The A solution is prepared by mixing 14-16 g of hydroquinone and 0.2-1 g of phenidone S with propylene glycol to make the volume to 100 ml; The B solution is prepared by mixing 14-16 grams of borax decahydrate, 17-19 grams of boric acid, 98-102 grams of anhydrous sodium carbonate, 98-102 grams of anhydrous sodium sulfite, 14-16 grams of potassium bromide, and 9-11 grams of potassium thiocyanate with deionized water to make the volume 1L; The bleaching solution is prepared by mixing 19-21 grams of sodium hexametaphosphate, 1.5-2.5 grams of potassium permanganate, 26-28 ml of sulfuric acid, and diluting the volume to 1 L with deionized water.

2. The reverse washing and developing solution according to claim 1, characterized in that: The concentration of the sulfuric acid is 20%.

3. The reversal washing and developing solution according to claim 1 or 2, characterized in that: The preparation method of the liquid A is as follows: add an appropriate amount of propylene glycol into a container, heat to 75-80° C., add hydroquinone and phenidone S, stir until completely dissolved, dilute to 100 ml, and cool to room temperature to obtain the liquid A.

4. The reversal washing and developing solution according to claim 1 or 2, characterized in that: The preparation method of the B liquid is as follows: add an appropriate amount of deionized water at 45-50° C. into a container, dissolve borax decahydrate, boric acid, anhydrous sodium carbonate, anhydrous sodium sulfite, potassium bromide and potassium thiocyanate in sequence under stirring, cool to room temperature, discard the precipitate and the precipitate, and take the supernatant to obtain the B liquid.

5. The reversal washing and developing solution according to claim 1 or 2, characterized in that: The preparation method of the bleaching liquid is as follows: add an appropriate amount of deionized water at 45-50° C. into a container, dissolve sodium hexametaphosphate and potassium permanganate in sequence under stirring, then slowly add 27 ml of 20% sulfuric acid, and cool to room temperature to obtain the bleaching liquid.