Formaldehyde is not a necessary direct material in the decoration, and the paint and adhesives are. The most commonly used adhesive is urea formaldehyde resin. During the production of urea formaldehyde resin, there will be a large amount of formaldehyde residue, which is known as free formaldehyde. This part of free formaldehyde will be released when paint is leveled and solidified, which is the direct source of formaldehyde harm. The so-called urea formaldehyde resin, abbreviated as UF, is known to be a resin condensed from urea and aldehyde. Urea is urea, formaldehyde is the most basic formaldehyde -- this is the modern chemical industry raw materials, bluntly said that the price of cabbage as raw material, urea and formaldehyde mixed together in acid or base catalyzed polymerization, the traditional process will add 1.5 times to 2 times the amount of formaldehyde to ensure products grade. Because urea formaldehyde resin viscosity is large, so after the reaction, there will be a large number of formaldehyde not mixed in the whole system, which is the free formaldehyde that causes formaldehyde harm.
The preparation route of urea formaldehyde resin is not the necessary thing for decoration, but also the residue that is bound to be limited to the existing mature production process when producing coatings and adhesives. Not who wants to add formaldehyde in the inside, in fact, formaldehyde itself does not have much use for decoration. The gentleman said, we don't use the urea formaldehyde resin. Using other harmless or no residual formaldehyde. Yes, this is now the direction of green chemistry and chemical industry aiming at decorating formaldehyde, and studying the alternatives of urea formaldehyde resin, but not yet good results. What is a good result? In fact, there are too many formaldehyde free adhesives. There have been many commercialized examples, such as polyisocyanate resin MDI, such as polyvinyl acetate PVA, but these things now can't replace urea formaldehyde resin quickly and completely. 1. first, the most critical reason, the most critical reason, is that the urea formaldehyde resin is too cheap to be TM.
This cheap is not only raw material -- urea and formaldehyde, the two basic chemical products are cheap, but also includes urea formaldehyde resin has formed a complete mature industrial chain.
In 80s, the world's urea formaldehyde resin output was already one million tons. Now it is estimated that the consumption of urea formaldehyde resin is only 2 million tons per year.
Now, at least in Jiezhuang wood products industry, the use of UF accounted for more than 90% of all the amount of adhesive, ten years ago, UF is almost all the only option with particleboard global adhesives -- traditional industries, the biggest problem is the inertia, but for a certain production process, to achieve in a short period of time to the more difficult than IT the industry is too much, and now is not too good direction. Other products try to compete with UF, which is very difficult at first. The cost of new products is not two times higher than that of UF, but tens of times or even hundreds of times. 2., the performance of urea formaldehyde resin as adhesive is pretty good, relative price. The so-called "three formaldehyde glue", refers to the three with the most traditional formaldehyde resin: urea formaldehyde resin, phenolic resin and melamine formaldehyde resin, urea formaldehyde resin which is the color of the light cured phenolic resin (dark colour, light color of the decoration adhesive to say is very important), and no urea formaldehyde resin curing can be mixed with water is better, the curing speed is very fast, but also a good bonding strength (for decoration enough).
Compared with the development of new adhesives, another more realistic route is to develop new urea formaldehyde resin production technology with lower free formaldehyde content. Many domestic and foreign universities, research institutes and R & D departments of enterprises are working in this direction. But the same reason, though many achievements have been achieved, none of them can fundamentally shake up the status of urea formaldehyde resin in the adhesive industry. It will take a very long time to eliminate formaldehyde completely in the field of home decoration.