No matter what, we broke into the polyurethane industry and are proud of the fact that polyurethane materials are the best among many chemical synthetic materials. However, when we really do it, we experience the hardship. Not only the products are varied, but also the influencing factors are varied. There is often the same kind of combination material, in the production of products, the normal conditions can produce qualified products, but due to the fluctuations of environmental temperature changes will be a problem, the ambient temperature is high, the material is too fast to start fearing that the injection time is not enough, or curing too fast foam is not in place. The ambient temperature is low to inject more material, and curing is slow, there is no ripening, foam brittle, bonding and other problems, more miserable is after a period of time the foam shrinkage. What is the reason? Is it because of operation? Do you want workers to improve? Experienced ones can follow the changes. But the root cause is that our material is too delicate. Do you remember how we mix the ingredients? Know the theory of calculating the index of isocyanate, in the preparation of white material, according to the ratio of feeding black and white material 1 ~ 1.05:1, with a good white material, and then do a small test.
Foaming measurement time period, the final measurement of wire drawing, what is the meaning of wire drawing? Is the formation of polyurethane structure began to gel due to the structure is viscoelastic foam began to be elongated, until curing, but to this change in the foam is not over, when the density is high enough, the ambient temperature is high enough, the foam by its own exothermic can be matured, no longer deformed. If this is not the case, it will be a disaster. This characteristic of polyurethane limits its application and development.
People call all materials with isocyanates in the reaction polyurethane, but no one has been able to synthesize and name the reaction between isocyanates and carbamates, and with urethane-based formates. It is because there is no catalyst that can catalyze the formation of carbamate when the isocyanate continues to react with it. The existing tertiary amine catalysts and organometallic catalysts also only solve the problem in the equilibrium of forming foaming gels of poly(carbamate). Nowadays, we are glad to find or synthesize a class of compounds called polytertiary amine formates, which present high catalytic activity as catalysts for multilevel and own trimerization of isocyanate and carbamate.
The structure of the catalyst is characterized by the presence of tertiary amines and organometallic salts. In the application of foaming, the comprehensive effect is shown in the first-level reaction of isocyanate, such as the generation of carbamate, and with water to generate CO2, replace the urea has a weak activity, while the depth of the reaction of isocyanate, that is, the second-level multi-stage self-polymerization reaction has a strong activity, which is shown in the slow foaming when used alone, no drawing curing can be matured, if shared with tertiary amine foaming catalyst, the early start shows the activity of tertiary amine If shared with tertiary amine foaming catalyst, the first phase of the foam starts to show the activity of tertiary amine.
The technology catalyst came out of nowhere, although there will be catalyzed target products from the first-stage reaction products urethane to multi-stage reaction products and their own trimer products, not only the final quality of the foam has changed, the foaming process has also changed observation, evaluation methods have also changed, for example: we found that the first-stage and multi-stage reaction of isocyanate is synchronized until the end of the foaming to the pressure in all directions, the driving force The base is the same, but also to measure the pulling wire as before? Promote the flow, the foaming time still need to be so long? Do we still need to be so strict about the curing time after promoting maturation? Foam in the unripe before the full has been issued without overfilling, while a small test free foaming height may not be enough; with slow maturation of the material is generally overfilled because as long as there is no maturation can be filled with a large number of materials to increase the heat to speed up maturation, the second is to fill the mold. And curing followed by ripening material when the display is full, and then more material will be squeezed out. This brings a whole lot of benefits in addition to saving raw materials. But it is not a panacea, as a catalyst it still needs to be used with a good tertiary amine catalyst with foaming activity to tend to perfection.
I have limited experience in dosing, so I would like to invite experts and experts in the industry to use your rich experience and wisdom to experience the change of the catalyst and the qualitative change of the product. We hope to make your combination material formulation easier, simpler and more stable, and become fun, so that the production operation of products has greater tolerance, and the products produced are all superb. Let’s all work hard, innovate boldly and struggle hard for China’s polyurethane industry to move to the forefront of the world and become a technological powerhouse. Seek change for your own strength. All actions are impermanent, and all things and changes are the result of the action of more than two elements of karma, so treat all things with the mindset of seeking changes, and will keep the peaceful mindset of being prepared.
Note 1: Using this system catalyst, if you want to achieve the desired effect, the index of isocyanate must be excessive, if you want to produce high temperature resistance, fuel resistance should be based on the height of temperature resistance, and flame retardant level can be increased exponentially.
