Application of Polyurethane Catalyst in the Synthesis of Hard Plate
Specifically, the invention relates to a catalyst for preparing polyurethane and the application of the catalyst, belonging to the technical field of polyurethane material synthesis.
Polyurethane is a general term for macromolecular compounds containing repeated carbamate groups on the main chain. This macromolecular material can be used to manufacture rubber, hard and soft foamed plastics, adhesives, coatings, paints and other products. It is widely used in construction, automobile, light industry, textile, petrochemical, metallurgy, electronics, national defense, medical Machinery and many other fields.
Polyurethane materials are made from polyisocyanates, polyols and other stabilizers by catalytic reaction of catalysts at a certain temperature. A class of catalysts commonly used in the synthesis of polyurethane materials are metal organic compounds. This kind of organic metal catalysts are organic compounds of lead and mercury. However, because lead and mercury are heavy metals, they are harmful to human health and cause serious environmental pollution, and have been listed as prohibited products.
This is an amine catalyst for preparing soft polyurethane foam with low emission and stable re catalysis, which includes at least one reactive amine catalyst and at least one organic potassium, zinc and/or tin compound, and has good catalytic activity. However, due to the use of tin compounds as a component of the catalyst in the above catalysts, organic tin catalysts contain unreacted dibutyltin, etc. Such by-products are easy to lead to biological abnormalities or chronic poisoning, so they have been included in the list of controlled use by developed countries such as the European Union. However, if organic tin compounds are not added and other organic compounds such as potassium and/or zinc are used instead of tin compounds, the catalytic activity of the catalyst will be significantly reduced. On the one hand, even if the reaction temperature is increased, the reaction speed will be reduced and the reaction time will be prolonged. On the other hand, if the reaction speed is similar to that of the tin containing catalyst, the amount of catalyst needs to be increased, for example, in the synthesis of synthetic leather slurry, Using organic bismuth to completely replace dibutyltin dilaurate, the amount will be 4-5 times of the original amount; Whether the former prolongs the reaction time, increases the reaction temperature, or the latter increases the amount of catalyst, the synthesis cost of polyurethane materials will be increased to varying degrees. Even so, the physical properties of polyurethane materials synthesized by its catalyst, such as tensile strength and tear resistance, will be significantly reduced. Moreover, when using the formula without tin compounds in the above literature, It is also easy to make the light color polyurethane material yellow; In addition, when the raw material formula of synthetic polyurethane contains water, the organic compounds of bismuth or zinc will be inactivated due to hydrolysis, which will shorten the storage period of the composite.
For this reason, the technical problem to be solved by the Institute is that the catalyst without tin organic metals in the prior art not only has low catalytic activity, but also has poor performance of the polyurethane material, so as to provide an environment-friendly polyurethane catalyst with high catalytic activity and good physical performance for the preparation of rigid polyurethane materials.
