Abstract: A preparation method for a self-thixotropic polyurethane curing agent includes the following steps: mixing an isocyanate and a crystalline polyester diol and/or polyether diol, reacting at a temperature between 70° C.-110° C., after a reaction, cooling to room temperature and standing still for more than 12 h to obtain the self-thixotropic polyurethane curing agent.

Abstract: A preparation method for a self-thixotropic polyurethane curing agent includes the following steps: mixing an isocyanate and a crystalline polyester diol and/or polyether diol, reacting at a temperature between 70° C.-110° C., after a reaction, cooling to room temperature and standing still for more than 12 h to obtain the self-thixotropic polyurethane curing agent.

Abstract: A preparation method for a salt-spray-resistant polyaspartic acid ester includes mixing polyaspartic acid ester, cardanol resin and a catalyst together for transesterification reaction, and controlling a temperature at 100-130° C. and a relative vacuum degree at ?0.095 MPa-?0.1 MPa, and stirring for reaction for 2-5 h to obtain the salt-spray-resistant polyaspartic acid ester; in particular, a molar ratio of the polyaspartic acid ester to the cardanol resin to the catalyst is polyaspartic acid ester:the cardanol resin:the catalyst=1:0.1-0.3:0.001-0.003, and the catalyst is tetraisopropyl titanate or dibutyltin oxide.

Abstract: A preparation method for a salt-spray-resistant polyaspartic acid ester includes mixing polyaspartic acid ester, cardanol resin and a catalyst together for transesterification reaction, and controlling a temperature at 100-130° C. and a relative vacuum degree at ?0.095 MPa-?0.1 MPa, and stirring for reaction for 2-5 h to obtain the salt-spray-resistant polyaspartic acid ester; in particular, a molar ratio of the polyaspartic acid ester to the cardanol resin to the catalyst is polyaspartic acid ester:the cardanol resin:the catalyst=1:0.1-0.3:0.001-0.003, and the catalyst is tetraisopropyl titanate or dibutyltin oxide.

Abstract: The present application relates to a field of anti-corrosion coating, in particular, relates to an aspartic polyurea coating including a polyaspartic acid ester: 36%-60%; a ketoimine: 4%-8%; a dispersant: 0.5%-1.0%; an organotin catalyst: 0.1%-0.2%; a titanium white powder: 0%-48%; a thixotropic agent: 0.2%-1.0%; a leveling agent: 0.05%-0.3%; an antifoamer: 0.1%-1.0%; an antiager: 0%-3.0%; a coupling agent: 0%-5%; a diluent: 0%-10% and component B isocyanate curing agent.

Abstract: Disclosed are a microwave power source and a method of adjusting operation frequency for a microwave oven. The microwave power source comprises: a phase-locked frequency generator configured to generate a plurality of operation frequencies; a standing wave detection circuit configured to detect, for each operation frequency, a standing wave in a chamber of the oven and provide information about the standing wave; and a microcontroller configured to select one of the operation frequencies based on the information, and control the generator to generate the selected operation frequency so that the microwave oven operates at the selected operation frequency. Embodiments of the present disclosure can automatically adjust the operation frequency of the oven according to VSWR in the oven chamber.