Appearance and Properties: White, lustrant, bitter-tasting crystals.

　　Melting Point (℃): 176～178

　　Boiling Point (℃): Decomposes; Relative Density (water=1): 1.41

　　Logarithm of Octanol/Water Partition Coefficient: 2.5

　　Solubility: Soluble in cold water and ethanol; slightly soluble in ether.

　　Main Uses

　　Pharmaceutical and Pesticide Industries

　　As a Drug Intermediate: Used for synthesizing sulfa drugs (e.g., sulfathiazole), antithyroid drugs (e.g., methimazole), and antitumor drugs; the sulfur atom in thiourea participates in the structural construction of biologically active molecules.

　　Pesticide Production: Used for synthesizing insecticides (e.g., thiourea insecticides), fungicides (e.g., isoprothiolane), and herbicides, utilizing their inhibitory effects on pests or pathogens.

　　Metallurgy and Electroplating Industries

　　Mineral Dressing: Acts as a flotation agent for sulfide ores, capable of selectively adsorbing onto the surface of metal sulfide minerals, enhancing the adhesion between minerals and bubbles, and improving dressing efficiency (e.g., separation of copper, lead, and zinc ores).

　　Electroplating Additive: Used in electroplating solutions to improve the gloss and uniformity of the coating, preventing pinholes or cracks; commonly used in the electroplating of metals such as copper and silver.

　　Metal Corrosion Inhibitor: Added to industrial water or lubricating oil to form a protective film by combining with the metal surface, slowing down metal corrosion (e.g., corrosion protection for steel and copper).

　　Organic Synthesis

　　As a Reducing Agent: Reduces nitro, nitroso, and other groups in organic reactions, or is used to prepare compounds such as thiols and isothiocyanates.

　　Used for Synthesizing Heterocyclic Compounds: Reacts with aldehydes and ketones to form heterocycles such as thiazoles and imidazoles; these structures are core skeletons for many drugs and dyes.

　　Chemical and Materials

　　Production of Thiourea Resins: Condenses with formaldehyde to produce thermosetting resins used in adhesives, coatings, or molding plastics, possessing acid and alkali resistance.

　　As a Rubber Vulcanization Accelerator: Accelerates the rubber vulcanization reaction and improves the hardness and wear resistance of rubber (e.g., processing of natural rubber and synthetic rubber).

　　Used in the Paper Industry: Acts as a bleaching aid to enhance pulp brightness, or as a water repellent for paper.