Common knowledge of coating: new waterborne polyurethane coating

Key tips: Section III new waterborne polyurethane coating Polyurethane paint, which contains active NCO group, will react with water, so the development of waterborne paint is difficult and slow Nowadays, there are two kinds of waterborne polyurethane paint One is thermoplastic, whose NCO group has reacted completely and synthesized into macromolecular polymer to provide enough mechanical strength and elasticity The other is thermosetting, which has been developed in recent years The coating is divided into two components, one containing active hydrogen and the other containing NCO group It can be crosslinked and solidified into film at room temperature or heating 1、 Thermoplastic waterborne polyurethane paint In the preparation of waterborne polyurethane coating, it is basically connected on the main chain of PU Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Home of coatings: the third section of the new waterborne polyurethane paint polyurethane paint due to the active NCO base will react with water, the development of its waterborne paint is more difficult and slow Nowadays, there are two kinds of waterborne polyurethane paint One is thermoplastic, whose NCO group has reacted completely and synthesized into macromolecular polymer to provide enough mechanical strength and elasticity The other is thermosetting, which has been developed in recent years The coating is divided into two components, one containing active hydrogen and the other containing NCO group It can be crosslinked and solidified into film at room temperature or heating 1、 In the preparation of water-borne polyurethane coating, thermoplastic water-borne polyurethane paint is basically made by emulsification after the main chain of Pu is connected with hydrophilic group or hydrophilic side group According to the types of these hydrophilic groups, they can be divided into cation, anion, nonion and amphoteric 1 after coating the cationic polyurethane water emulsion, the salt forming agent evaporated and the hydrophilic ammonium group became amine, resulting in the formation of hydrophobic film It can be used as leather finishing agent 2 PU emulsion was prepared by acetone method with anionic polyurethane wateremulsion 3, Pu Pu IPN emulsion Acetone was extracted in vacuum during postprocessing If acrylate monomer is used as solvent, PU emulsion can be prepared, and initiator is added to make the monomer polymerized in the emulsion to form polyacrylate Because the aggregation is in the network of PU, the final result is interpenetrating network Polyurethane emulsion particles on the surface of water swelling, is conducive to interparticle and synthetic membrane, therefore, although no film additives, its MFFT (minimum film temperature) is still very low, and the film is very hard, acrylic emulsion is not enough 2、 Thermosetting waterborne polyurethane paint has been successfully developed by utilizing the slow reaction of aliphatic isocyanates (such as IPDI, hmdi, TMXDI) with water The preparation method is as follows 1 The hydroxy component first reacts diisocyanate with hydroxy diol and DMPA to make prepolymer, then neutralizes with tertiary amine and disperses in water, similar to the above operations 2 The polyisocyanate component is HDI Trimer, which reacts with polyethylene glycol monobutyl ether The product contains NCO and can be dispersed in water Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,