Coating of water dispersible polyisocyanate crosslinking agent

Coating of water dispersible polyisocyanate crosslinking agent,At present, the water can be dispersible polyisocyanate crosslinking agent has two kinds: the first kind, hydrophobic especially low viscosity isocyanate, such as used for conventional two-component polyurethane coating of isocyanate; The second, modification of hydrophilic emulsion isocyanate. With HDI and IPDI based on the market at present the two crosslinking agent.

Low viscosity hydrophobic isocyanate must with more suitable organic solvent, and in high shear force (such as using the mixing or dispersing equipment), can be mixed with water medium. And modified hydrophilic isocyanate with simple manual mixing, more can be achieved without cosolvent makings and crosslinking agent of homogeneous mixture.

Aliphatic or alicyclic isocyanate (e.g., HDI or IPDI trimer), and inadequate single functionality polyethylene oxide polyether glycol, simple reaction generated containing polyether urethane nonionic emulsifier mixture of isocyanate. In this way, the modification of the hydrophilic isocyanate is easy to use more manual mixing emulsion in water, without applying high shear force. This class can be more water emulsion isocyanate (for example, Bayhydur3100 Bayhydur401-70) has been identified as most of the use of standard water-based coatings and adhesives crosslinking agent.

Although polyether modified isocyanate used more widely, but they have a fundamental weakness, especially when used as a crosslinking agent of waterborne two-component polyurethane coatings, need higher content of polyether, to ensure enough dispersivity, this leads to a long drying time, and give lasting hydrophilic coating. More than it is for these reasons, polyether modified isocyanate was not the requirements of the highest level of patience (such as applications in automotive primer or antigraffiti coatings). These disadvantages can be eventually through the development of more than special ionized modified isocyanate and be able to overcome.

Aliphatic isocyanate and 3 - (hexanaphthene amino) - 1 - propane sulfonic acid (CAPS) (the latter sulfamic acid salt of zwitterionic), under mild conditions and reaction in the presence of tertiary amine neutralizer, generated sulfonic acid urea derivative is an excellent emulsifying agent.

Not consider into salt group, more CAPS modified isocyanate has good storage stability, not cloudy, even if have fewer sulfonate groups, also can be dispersed in water good emulsion.




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine Raw material ：

TDA industrial, Sichuan production

Ethylene (Et) polymer grade, Shanghai production

TEA industrial imports

A reagent grade additives


For more than a series of ionized modified isocyanate (e.g. BayhydurX2487/1, BayhydurXP2547 BayhydurXP2570 BayhydurXP2655), used for all kinds of environmentally friendly waterborne two-component polyurethane coatings with high quality. These coatings in terms of drying, chemical crosslinking and patience, completely can be compared with the general solvent coatings.

New regulations require further reduce the VOC (volatile organic compounds), the dosage of crosslinking agent will soar in the future, compared with solvent paint, they do not lead to the decrease of the quality of the paint film.

Flocculation regiment of the dispersion of solid particles or droplets, uniform in water or other liquid medium, can be dispersed into tiny particles suspended in the performance of the dispersion medium without precipitation.

Associated with the specific surface area of material dispersion, specific surface area is good dispersibility. The dispersivity of the commonly used material dispersion said. Divided according to the dispersed particle size, molecular dispersion (dispersed material particle size less than 10 ^ 7 cm), colloidal dispersion (dispersed material particle size 10 ^ 7 ~ 10 ^ 5 cm), coarse dispersion (dispersed material granularity in 10 ^ 5 ~ 10 ^ - 3 cm).

Points is a typical feature of soft material dispersion, the strength of the soft material properties are determined by the system of polydispersity (fluctuation). Polymer as a kind of soft material, the primary structure of the polydispersity is bound to affect or reflect on its structure and property of the state of aggregation on the polydispersity.

The crystallization of the crystalline olefin copolymer of polydispersity in sequence's length, have the same copolymer composition close to or sample processing and use of performance may have obvious difference. Fluctuation and the influence of polymerization conditions control the crystallization of the crystalline olefin copolymer polydispersity sequence's length, so the olefin copolymer polydispersity crystallization in the sequence's length.

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