Coating with HDI biuret crosslinking agent

Coating with HDI biuret crosslinking agent.In a quaternary ammonium alkali as catalyst synthesis of HDI trimer product, trimer, polymer, dimers and HDI monomer mass fraction in the product were 62% ~ 64%, 29% ~ 31% and 29% ~ 3% and 2% ~ 3%. Table 1 is under the effect of several catalysts of HDI three main properties of the products.

Is particularly pointed out that with no active hydrogen atoms, rings do not form intramolecular or intermolecular hydrogen bond, and thus the viscosity of the product is very low, about HDI biuret type one over ten of the crosslinking agent. After vacuum distillation or film evaporator treatment of melamine product also contains a small amount of HDI monomer, someone put forward using inert gas or solvent to post-processing of melamine products, mass fraction of HDI monomer can drop to below 0.04% ~ 0.005%.

Compared with HDI biuret, HDI trimer has the following advantages:

(1) the HDI trimer low viscosity, can use or not use less solvent, made of high solid content of products, to reduce pollution, protect the environment;

(2) the HDI trimer of different melamine urea acid ester base is stable, not easy metamorphism, viscosity changed little after storage, less effect on performance;

(3) the HDI system of melamine product of heat, light resistance, corrosion resistance and solvent resistance were higher than HDI biuret.

(4) the HDI trimer crosslinking agent lasts long, is advantageous to the construction operation;

(5) the HDI (system of high hardness, toughness and adhesion force and HDI biuret.

HDI trimer applications

(1) the HDI trimer mixed with a polyacrylic ester polyols, for low carbon steel coated sex is good, bright and clean degree was 94%, and the chemical solvents such as toluene resistance at the same time.

(2) the HDI trimer with polyester film at 28 ℃ after 6, 12 and 18 months, its gloss retention rate of 93%, 85% and 42% respectively, and corresponding value standard coating are 92%, 70% and 92% respectively, shows the HDI trimer of prominent role in the persistence and resistance to weathering.

(3) an HDI trimer crosslinked coating layer, can very good resistance, resistance to chemical reagent, good corrosion resistance.

(4) in three kinds of derivatives crosslinking agent HDI, make the order of the acrylic coating color yellow is from fast to slow, HDI biuret > HDI - > TMP adduct HDI trimer.




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine packing： net weight 200KG/ galvanized iron drum (a small cabinet pallet loaded 16 tons), 1000KG/IB barrels (a small cabinet loaded 18 tons or 23 tons of ISOTANK).


(5) with different melamine urea acid ester base has good thermal stability, HDI trimer and recording materials coating can be used in the heat of the coatings.

Quaternary ammonium salt catalysts. Scholl, Fujita, Kumada and Ueyanagi using quaternary ammonium salt as catalyst, the HDI melamine products.

Quaternary ammonium alkali catalyst. Quaternary ammonium alkali as the catalyst was first used in TDI and IPDI, in recent years, and the success of HDI. Since quaternary ammonium alkali synthesis is simple, smooth, high catalytic efficiency, can be at room temperature, and rapid development.

Quaternary ammonium alkali catalysis of HDI from polyethylene reaction without induction period, stable reaction, can carry on bulk polymerization. Its biggest advantage is that at the end of the polymerization reaction, not to join the termination agent, by using the properties of quaternary ammonium alkali on the thermal instability, only warming can termination reaction catalyst decomposition, HDI melamine product won't produce gel or precipitation.

Compared with metal salts, quaternary ammonium alkali catalytic generated from the products of more annular polymer, this suggests that the quaternary ammonium alkali catalyst activity be larger.

HDI trimer colorless to light yellow transparent liquid, isocyanate root mass fraction is high, low viscosity, low steam. With the formation of cyclic polymer, HDI trimer of isocyanate root mass fraction is less than the theoretical value; Ring the mass fraction of polymer, the greater the product of isocyanate root mass fraction, the greater the deviation from the theoretical value.

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Diethyl toluene diamine(DETDA)  http://www.yaruichem.com