Investigaton On The Photographic Developing Composition Containing Ascorbic Acid And Phenidone

The developing solution containing hydroquinone as major ingredient has been used for quite a long time. However, the toxicity of hydroquinone has always been a huge threat to manipulator and environment. Thus, the use of nontoxic and harmless developing agents without hydroquinone is more and more popular these years. In this dissertation, we used environmental–friendly ascorbic acid to take the place of toxic hydroquinone and designed the ascorbic acid-phenidone developing prescription. In order to discover the relationship between the major ingredient and developing performance, we carried out comprehensive study and found out that the developing effects were greatly influenced by the mass ratio of ascorbic acid and phenidone; the dosage of antioxidant and antifog agent; pH value of developing solution. According to the optimization experiments upon the dosage ratio mentioned above, when the mass ratio of phenidone and ascorbic acid is 5:100; the mole ratio of anti-oxidant and ascorbic acid remains between 3.6:1 and 5.6:1; the concentration of anti-oxidant remains between 0.3 and 0.5M; and the pH value of the developing solution remains between 9.3 and 9.6, the obtained PA solution performs the best developing, anti-oxidation and deposition effects. Moreover, the combined use of the potassium bromide and BT could result in cooperation effect. When 0.9g potassium bromide was used in combination with 0.3ml 10% BT solution in 1L of developing solution, the minimum developing fog could be achieved. Developing performance experiments indicated that the PA solution could function under the temperature between 20 and 26℃. The best developing condition might be with temperature of 20℃and developing time of about 5 minutes. Application experiments showed that the PA solution could be used for the development of industrial and medical X-ray film, and could perform as well as the commonly used D-19b developing solution.