Isocyanate crosslinking agent class coating

Isocyanate crosslinking agent class coating,Polyurethane resin with excellent comprehensive performance is often used to high-end paint raw materials.

Using isocyanate crosslinking agent crosslinking hydroxyl polyester resin is an important variety of powder coating.
But the activity of isocyanate group is very high, in the process of preparing powder coating BH will need to adopt closed agent isocyanate group closed, when the crosslinking crosslinking to unlock. Using isocyanate as more diisocyanate (HDI) and isophorone diisocyanate (IPDI) trimer or oligomer.

Using closed isocyanate crosslinking agent disadvantage is that the paint film crosslinked sealants leave system, affect the paint film density and produce some pollution problems. In order to reduce the dosage of blocking agent, also can be used from the shrinkage of IPDI form urea diketone structure, shrinkage urea diketone points at certain temperatures can solution to release the isocyanate groups.

Beta dicarbonyl compounds malonic diethyl isocyanates can be closed, and in 120-140 ℃ low temperature crosslinking, and can be used in epoxy and its mixed formula, is a kind of very promising crosslinking agent at low temperature.

Oxime (butyl ketone oxime) is commonly used in closed isocyanate, crosslinking exhalation oxime, no unpleasant odor, crosslinking temperature is low, and cooperate with hydroxyl-terminated polyester used for polyurethane powder coating, but the yellowing problem.
Isocyanate is the floorboard of all sorts of isocyanic acid ester. If the number of classification with - NCO groups, including single isocyanate R - N = C = O and diisocyanate O = C = N - R - N = C = O and more isocyanate, etc.

Single isocyanate is one of the important intermediates in organic synthesis, can be made into a series of carbamate insecticides, fungicides, herbicides, and also to improve waterproof plastic, fabric, leather, etc. More than two functional groups and isocyanate can be used in the synthesis of a series of excellent performance of polyurethane foam plastic, rubber, elastic fiber, paint, adhesives, synthetic leather, artificial wood, etc.

Currently, the largest output is the most widely used are: Toluene Diisocyanate (Toluene Diisocyanate, TDI); Diphenyl methane Diisocyanate (Methylenediphenyl Diisocyanate, MDI).




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine Uses:

The product is identical to Ethancure 100 and Lonza DETDA 80, DETDA is very effective polyurethane elastomer chain extender; also be used as polyurethane and epoxy resin curing agent, epoxy resin of an antioxidant, industrial oils and lubricants . In addition, also as intermediates in organic synthesis.Especially for the RIM (reaction injection molding), is important in the field of spray polyurea chain extender species. Also can be used for casting polyurethane elastomer (CPU) and a curing agent, epoxy curing agent, epoxy resin of antioxidants, lubricants and industrial oils other antioxidants.


Toluene diisocyanate (TDI) is a colorless, has a strong pungent flavour liquid, the boiling point of 251 ° C, specific gravity 1.22, with light black, has strong stimulation to the skin, eyes, and can cause eczema with bronchial asthma, is mainly used for polyurethane foam plastics, coating, synthetic rubber, insulating paint, adhesives, etc. According to its composition, tdi is a nitrogenous base of organic compounds.

Diphenyl methane diisocyanate (MDI) is divided into pure MDI and crude MDI. Pure MDI under normal temperature for white solid, when heated to stimulate the stink, the boiling point of 196 ° C, it is mainly used for rigid polyurethane foam plastics, synthetic fiber, synthetic rubber, synthetic leather, adhesives, etc. According to its composition, pure diphenyl methane diisocyanate was nitrogenous organic compounds.

And the yellow variant 1, 6 - diisocyanate (HDI).

Industry mainly adopts primary amine production isocyanate phosgene method, the reaction is as follows: by diamine diisocyanate can be obtained from phosgene method: with the progress of science and technology and the deepening of the synthesis theory, nitro compounds directly with carbon monoxide catalytic synthesis of isocyanate process of high temperature and high pressure is more and more mature.

The floorboard of the various kinds of ester of isocyanate. One isocyanate R - N = C = O and diisocyanate O = C = N - R - N = C = O. The liquid is generally unpleasant smell. A isocyanate is easy with ammonia and amine type, easy to the role of alcohol and carbamate (e.g., amino ethyl formate).

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