Organic bismuthBismuth belongs to Group 15 in the periodic table of elements and is the most metallic in this group. Element is the heaviest stable element in the periodic table.
Bismuth compounds have green and safe properties such as low cost, easy handling, low toxicity and low radioactivity. In the past 10 years, both the synthesis of new organobismuth compounds and the research on organobismuth compounds in organic synthesis, catalysts and biomedicine have been at a leading level. Rapid development stage. Organic bismuth products produced in advanced foreign countries have a history of more than 30 years and have been supplied to the European and American markets for many years. These environmentally friendly organobismuth catalysts can be cured at room temperature or under heat, making them an excellent alternative to toxic lead, mercury and tin products.
1. Safe and environmentally friendly, it can replace lead, mercury and tin which are being abolished by legislation; 2. It has better hydrolysis resistance, reduces the selectivity of reaction with water, and reduces the amount of water and NCO in water-based PU dispersions. side reactions; 3. Promote NCO/OH reaction, avoid NCO side reactions, and reduce the generation of CO2; 4. In a one-component system, liberate the amine shielded by water instead of promoting the reaction between NCO and water; 5. The combination of bismuth and zinc has a synergistic effect, making the formulation and production more flexible, reducing energy consumption, and increasing profits; 6. It can be used alone or in combination with amines or other organic metal compounds;
The environmentally friendly organic bismuth catalyst is slightly yellow and transparent Liquid, the viscosity increases as the metal content increases, has a special compound smell, and is soluble in commonly used polyurethane raw materials. It is used as a polypolyurethane catalyst and is not a restricted metal. It complies with domestic and foreign environmental protection regulations and is an environmentally friendly substitute for eliminating traditional organotin, mercury, lead and other catalysts. . Recommended for use in industries such as runways, etc. Organic bismuth of different categories and metal contents can be customized according to the specific requirements of customers. It has good compatibility and can be used alone or in combination with other organometallic compounds.
3. Application fields are common in all areas of the polyurethane industry, such as elastomers, coatings, foams, sealants, PU synthetic leather, shoe materials, runways, etc.
4. How to use organic bismuth alone will generally cause the viscosity of the polyurethane reaction system to rise rapidly, the fluidity will become worse, and the construction time will be shorter; it is more often combined with organic zinc Used in combination. The suitable bismuth-zinc ratio is tested according to different formulas and process requirements.
For organic bismuth, the ratio of bismuth-zinc is generally between 1:1-1:10, with 1:4 being the most common. When using the bismuth-zinc compound, it is recommended to add the polyol (component B, material P) component. It is best to add it after dehydration and stir evenly. It is not recommended to add it to the isocyanate component (Group A component). If it must be added, be sure to conduct applicability and storage stability tests first. The dosage is related to the product system and hardness. Generally, the dosage of the compound is 0.1~1% of the weight of the P material.
