Precautions of thiourea dioxide:

If proper measures are taken to avoid heat, moisture and external contamination, the material could maintain stability for a long time. In handling the material, please observe the following precautions:

Store in dry and clean warehouse with good ventilation conditions and room temperature below 30℃. Keep the product away from kindling material, heat sources and direct sunshine. Pay attention to moisture and rain prevention measures. Maintain the containers closed, and ensure the label is intact and available. Handle with care in the loading and unloading process to prevent damage of package and containers. Please pay attention to maintain the normal pressure relief of the container. Transportation should not be arranged in rainy days. The product shall be stored separately with flammable or combustible materials, reducing agent, sulfur, phosphorus, etc.

As a reducing agent, thiourea dioxide shall keep away from oxidants like chlorine based bleach, percarbonic acid soda, peroxysulphate, etc. The reaction will be accelerated if contacting with water.

After contacting with steam tube, welding park, electric heater and other heat sources, it will generate irritative odor and decompose. Friction of the material will generate heat transmission, which would be very dangerous. Please pay attention to avoid such situation. The heat generated from the decomposition will further decomposition.

Thiourea dioxide shall not be placed back to the original package after take-out or leakage. Contamination of dirty material, iron rust, moisture and other pollutant will accelerate its decomposition. The leaked material shall be dissolved with massive water.

In handling or storing products or water solution of thiourea dioxide, plastic containers are the most suitable containers. Stainless steel, ceramic and glass containers could also be used. In the storage process, the water solution of thiourea dioxide will decompose slowly and generate sulfuric acid. At the same time, the pH value will gradually decrease. Please avoid using iron, copper and aluminum containers to store the material.

Safety instructions: S24/25: avoid skin and eye contact.

Marks of dangerous goods: Xn: hazardous substance

Hazard category code: R22: harmful if swallowing.

R36/37/38: irritative to eyes, respiratory tract and skin.

Introduction to applications of thiourea dioxide

The product is an important intermediate for nitrogen compound in organic and inorganic chemical industry. Originated from fiber industry, the product has been used for in the early period. It has also been widely used in chemical industry and roll film industry, etc. Thiourea dioxide is a stabilized compound, and the using methods shall be same with other reducing agents, which does not have any harm. Moreover, the bad smell of sulfide is very limited, and it is very safe in operating environment and health.

Fiber Industry

Bleaching: thiourea dioxide has excellent bleaching effect to natural fibers like wool, silk, cotton, etc. In particular, it has exceptional performance in weak base environment. In the bleaching process, it will not damage the fibre. Moreover, the treatment of the wasted liquid of the bleaching agent is much easier.

Dyeing: it could achieve the purpose by using only 1/10 of the original dosage of hydrosulphite for the dyeing of disperse dye and sulfur dyestuff. Due to the high reduction potential of thiourea dioxide, please be noted that the color tone will change along with changes in types of dyes or concentration of thiourea dioxide.

Reduction and cleaning: on account of the strong reduction property, thiourea dioxide has exceptional performance in the reduction and cleaning of fibers dyed with disperse dyestuff, and it has high stability in the alkaline reduction bath. It could achieve the purpose by using only 1/4 of the original dosage of hydrosulphite. Therefore, it is very economical.

Discharge printing: with the feature of high reduction potential and high stability, it could be used in the discharge printing of all materials.

Shrink-proof finishing: in using thiourea dioxide and polyamide for shrink-proof finishing for wool, thiourea dioxide could promote the absorption of fiber to chemical agents.

Decoloration: in comparison with other chemical agent, thiourea dioxide has higher reduction and decoloration performance for dyestuff. Therefore, it could be used for the decoloration of recoloring and cleaning of staining jax.

Paper Pulp

Wood pulp: thiourea dioxide is applicable for the reduction and bleaching of high step trap paper pulp, especially for neutral to weak alkaline environment. Moreover, it could acquire paper pulp with high brightness after mixing with DIP bleaching agent.

Chemical paper pulp: thiourea dioxide could acquire the color beyond the reach of previous bleaching agent in bleaching KP, SP, soda pulp and other chemical paper pulp. Moreover, it could perform non-chlorine bleach after using together with semi-bleached paper pulp H2O2. The former chlorinated bleaching agent and thiourea dioxide could be used together for multi-section bleaching. In the digesting of soda paper pulp, the combined application of thiourea dioxide could improve the whiteness. In the chlorinated bleaching of KP, combined application of thiourea dioxide could be considered to prevent the reduction in strength.

DIP: the general alkaline treatment in the deinking of old newspaper, old magazine and ancient paper will result in lower whiteness. Thiourea dioxide could restore the whiteness. In order to age DIP and H2O2 with superior quality, the product may be used together with other bleaching agent to perform two to three sections of bleaching. Thanks to the resource protection activities, prevailing recycling of old newspaper and strict requirements for chlorinated bleaching, the combined applications become more and more popular.

Biomass cellulose

Thiourea dioxide could be used in the reduction and bleaching of biomass cellulose.

Synthetic fibre

In spinning acrylic fiber, we may place acrylic fiber and thiourea dioxide into the spinning bath together or place the spinning silk into the water solution with thiourea dioxide. After drying, we could get superior products with high whiteness. Thiourea dioxide could improve the dyeing performance.

Polymerization reaction

Vinyl compound: most vinyl compounds would perform polymerization reactions under the catalysis of oxidizing agents like peroxide, persulfate or hydrogen peroxide and the reducing agent like thiourea dioxide.

Acrylonitrile compounds: the polymerization of acrylonitrile compounds with the concentration above 80% will generally take persulfate or hydrogen peroxide and thiourea dioxide as the catalysts for oxidation and reduction.

Chloroprene compounds: the polymerization of chloroprene compounds will generally take persulfate or hydrogen peroxide and thiourea dioxide as the catalysts for oxidation and reduction.

Others: in order to cotton, linen, grafted polyvinyl compound and vinyl compound, persulfate or hydrogen peroxide and thiourea dioxide would generally be used as the catalysts.

Organic synthesis.

Thiourea dioxide could reduce aldehydes into primary ethanol, reduce ketone into secondary ethanol, or reduce nitryl in organic nitrogen-containing compound and reduce thiourea dioxide in organic sulfide into thioredoxin.

Inorganic synthesis

Thiourea dioxide could be used to recycle valuable metals like platinum, silver and uranium, and remove heavy metal like iron, cadmium, nickel, etc.

Roll film industry

In the roll film industry, thiourea dioxide could improve the photo-electric sensitivity of silver compound. It could be used as sensitizers of anti-fouling agent, or reducing agent for heavy amino dyestuff.

Detergent

In addition to the bleaching function, Thiourea dioxide could also remove iron, blood and other dirt in cloth if it is used to clean cloth.