The hardener 2,4-dichloro-6-hydroxy-s-triazine sodium salt can be prepared by using Sodium Metaborate instead of Sodium Bicarbonate,the hardening effects of the products prepared by both methods are basically the same,but the product yielded by the new method can be kept well at room temperature.

Taking the making of the transmission hologram using the recording material of silver halides as an example, this paper puts forward the auxiliary technics adopting respectively reduction, hardening, bleaching, etc.

The hardener 2,4-dichloro-6-hydroxy-s-triazine sodium salt can be prepared by using Sodium Metaborate instead of Sodium Bicarbonate,the hardening effects of the products prepared by both methods are basically the same,but the product yielded by the new method can be kept well at room temperature.

The author synthesized a series of chrome-containing organic compounds performing very promising characteristics when used as hardener in photographic materials,e.

The result shows that the pretreatment is the key for sloving the unifor-mity,brightness and firmness of coloring of stainless steel, and the abradability of color film is decided by the firmly treatment.