SOLID DISPERSION, PROCESS OF PRODUCING SOLID DISPERSION, AND HEAT DEVELOPABLE PHOTOSENSITIVE MATERIAL

1 . A process of producing a solid dispersion of an organic compound, comprising:

solid dispersing an organic compound, so as to form a dispersion; and then heating the dispersion,

wherein the heating comprises a step in which a temperature is elevated stepwise to subject the dispersion to a heat treatment,

wherein

(A) the stepwise elevation comprises at least two stages defined by (B) set forth below, and

(B) wherein the stepwise elevation comprises a first stage of keeping the dispersion from 30 to 50° C., and then a second stage of elevating the temperature to 60° C. or higher.

2 . The process according to claim 1 ,

wherein each stage in the stepwise elevation is for five minutes or longer.

3 . The process according to claim 1 ,

wherein the organic compound is a photographically useful organic compound.

4 . The process according to claim 3 ,

wherein the photographically useful organic compound is a polyhalogen compound, a bisphenol compound or a compound capable of forming a hydrogen bond to a bisphenol compound.

5 . A solid dispersion of an organic compound prepared by the process according to claim 1 .

6 . A heat developable photosensitive material, comprising:

a support; and

a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder on one surface of the support,

wherein the heat developable photosensitive material is produced through a step of applying a coating solution containing the solid dispersion of an organic compound according to claim 5 and then drying it.

7 . The heat developable photosensitive material according to claim 6 ,

wherein the organic compound is a polyhalogen compound, a bisphenol compound or a compound capable of forming a hydrogen bond to a bisphenol compound.