Substances which are subject to microbial spoilage are preserved by addition of a dihydrocinnamyl phenol, e.g., dihydro-2-cinnamyl-phenol, dihydro-4-cinnamyl-phenol, dihydro-2-cinnamyl-4-methylphenol, etc.
A photocurable soluble resin suitable for manufacturing photosensitive resin plates obtained by polycondensing an alkylol derivative or an alkylated alkylol derivative of urea or thiourea with an N-alkylolacrylamide or N-alkylolmethacrylamide in the presence of an acid or an ammonium salt thereof or by reacting urea or thiourea with formaldehyde to form a linear polycondensation product and then grafting an N-alkylolacrylamide or N-alkylolmethacrylamide on the linear polycondensation product in the presence of an acid or an ammonium salt thereof. This soluble resin is incorporated with known soluble resins such as soluble nylon, photosensitizers and thermal polymerization inhibitors and mixed thoroughly to obtain a soluble photosensitive resin composition.