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Urea-formaldehyde resin urea-formaldehyde resins
Trade name Beetle. Also known as urea formaldehyde resin, known as UF, with an average molecular
weight of about 10000. Aqueous solutions of urea formaldehyde and 37% acid or Base catalyzed by
polycondensation of urea formaldehyde oligomer linear industries with alkali catalyst, 95 ℃ or reactions, formaldehyde/urea molar
ratio of 1.5~2.0 to ensure the resin curing. Reaction step generates a and dimethylol urea, and
hydroxymethyl further condensation with amino, get soluble resin, using acid catalysis
Lead gel. Storage products required in the neutral condition. Linear urea-formaldehyde resin with ammonium chloride as hardener at room temperature when curing. Moulding
powder in the 130~160℃ heat cure, promoters such as zinc sulfate, methyl tributyl phosphate, diethyl
oxalate can accelerate the curing process. Urea-formaldehyde resin is mainly used in the manufacture of molded plastic, manufacture household life and
electrical parts, sheet metal adhesives, paper and fabric used for pulp, plywood, decorative panels, and
so on. Due to its light color and color products, often colorful and magnificent. Low cost ureaformaldehyde resin, light in colour, hardness, resistant to oil, mildew-resistant, has better insulating properties and temperature resistance, but poor weatherability and
water resistance. It was one of the earlier development of thermosetting resin. In 1924, United Kingdom
Cyanamid company in 1928, began selling the product, mid 30 thousand tons, 80 the world’s annual
output of more than 1.5Mt. Production of urea-formaldehyde resin used in plastic products only accounted for around 10%. In formaldehyde and urea
of Moore than lower of situation Xia business have of urea aldehyde resin, and filler (pulp, and wood
powder), and color material, and lubricant, and hardener, and stable agent (six Asia methyl four amine,
and carbonated ammonium), and plasticizer (urea or sulfur urea), component mixed, again after dry, and
crushed, and ball mill, and sift, that have urea aldehyde pressure plastic powder. Suppression of urea-formaldehyde plastics 140~150℃ of temperature, pressure, 25~35MPa, pressing time varies according
to the thickness of the product, usually 10~60min. Plastic products mainly of electrical lighting equipment
and phone parts. Urea-formaldehyde resin for water-soluble resins, more easily cured, cured resin is nontoxic, colorless, good light resistance, long term use
do not change color, thermoforming and do not change color, you can also add colorant to produce a
variety of brightly coloured products. Urea-formaldehyde resin hard, scratch-resistant, weak acid and grease-resistant, and other media, cheap, has a certain toughness, but it is easy to absorb water, so less water
resistance and electrical properties, heat resistance is not high.
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