What kind of glue do you want to make the plywood?
The first step of the reaction is to produce one and dihydroxy methyl urea, and then to further condensation of hydroxymethyl with the amino group to obtain a soluble resin, which, if catalyzed by acid, results in a gel. The product should be stored under neutral conditions. Linear urea formaldehyde resin can be cured at room temperature with ammonium chloride as curing agent. The molding powder is heated at 130~160 DEG C, and the accelerator, such as zinc sulfate, phosphoric acid trimethyl ester and oxalic acid two ethyl ester, can accelerate the curing process. Urea formaldehyde resin is mainly used in the manufacture of molded plastics, making daily necessities and electrical components, as well as adhesives for sheets, paper and fabrics, paste panels, building decorative panels, etc.. Because of its light color and easy to color, the products are often rich in color and magnificent.
Urea formaldehyde resin has low cost, light color, high hardness, oil resistance, mildew resistance, good insulation and temperature resistance, but its weather resistance and water resistance are poor. It is one of the thermosetting resins developed earlier. In 1924, the British developed melamine company, beginning in 1928, the sale of products, the mid 30s output reached thousand tons, in 80s the world's annual output has more than 1.5Mt.
Urea formaldehyde resin is the main adhesive for wood industry at home and abroad, because of its high strength, fast curing, good operation, low production cost, rich raw materials and easy access to a wide range of advantages and so on.
The cured urea formaldehyde resin is lighter in color and lighter in appearance than phenolic resin, and has weak acid and weak base, good insulation property, excellent abrasion resistance and low price, but it can be easily decomposed with strong acid and alkali, and has poor weather resistance. Trade name Beetle. 37% urea and formaldehyde in aqueous solution can be obtained by the polycondensation of linear urea formaldehyde oligomer in catalytic acid or alkali industry, with alkali as catalyst, reaction temperature of about 95, molar ratio of formaldehyde to urea is 1.5 ~ 2, to ensure that the resin can be cured
UF resin can be used.Urea formaldehyde resinUrea-formaldehyde resinsUrea reacted with formaldehyde to obtain the polymer. Urea formaldehyde resin. English abbreviation UF. Crosslinking occurs during processing, and the product is insoluble and non - fusible thermosetting resin.
