Polyurethane adhesive molecular chain contains carbamate group (-NHCOO-) or isocyanate group (-NCO), divided into polyisocyanate and polyurethane two categories.Polyurethane adhesives, through the reaction of isocyanate groups in the system and substances containing active hydrogen inside or outside the system, generate polyurethane groups or polyurea, so as to greatly improve the strength of the system and achieve the purpose of bonding.
Adhesives are mainly adhesive, with various curing agent, plasticizer, fillers, solvents, preservatives, stabilizers and coupling agents and other additives prepared.In recent years, with the rapid improvement of the level of material development, a variety of adhesives with stronger applicability came out one after another, which greatly enriched the adhesive market.
1. Development status
Polyurethane adhesive is a kind of middle and high grade adhesive, which has excellent flexibility, impact resistance, chemical resistance, wear resistance, and the most important is its low temperature resistance.By adjusting the raw material and formula, we can design a variety of polyurethane adhesives which are suitable for the bonding between various materials and different uses.Polyurethane adhesive was first used in the military field in 1947. By Bayer company, triphenyl methane triisocyanate was successfully applied to the bonding of metal and rubber, and used on the track of tank, which laid a foundation for the polyurethane adhesive industry.Japan introduced German and American technology in 1954, began to produce polyurethane adhesives in 1966, and successfully developed water-based vinyl polyurethane adhesives, which were put into industrial production in 1981.At present, the research and production of polyurethane adhesives in Japan are very active, and together with the United States and Western Europe, Japan has become a major producer and exporter of polyurethane.Since 1980s, polyurethane adhesives have developed rapidly, and now they have become a wide variety and widely used industry.
In 1956, China developed and produced triphenyl methane triisocyanate (Lekner adhesive), and soon produced toluene diisocyanate (TDI) and two-component solvent-based polyurethane adhesive, which is still the largest variety of polyurethane adhesive in China.Since then, China has introduced many advanced production lines and products from abroad, in which a large number of imported polyurethane adhesives are needed to support them, thus promoting the development of polyurethane adhesives in domestic research units.Especially after 1986, the polyurethane industry in China has entered a period of rapid development.In recent years, the price of polyurethane glue is decreasing, and the current price of polyurethane glue is only about 20% higher than that of chloroprene glue, which provides the conditions for polyurethane glue to occupy the chloroprene glue market.
Post time: Mar-03-2021