Cationic Electrodeposition Emulsion Preparation Without Desolvation

The patent changes the temperature parameter during emulsion preparation (elevated temperature of 50-100°C) to reduce resin viscosity and improve handleability without adding organic solvents. This temperature parameter change allows the resin to be processed at lower solid contents while avoiding the need for MIBK and xylene, thus resolving the contradiction between ease of operation and environmental load.

The patent replaces expensive and environmentally harmful organic solvents (MIBK and xylene) with a temporary elevated temperature condition that serves the same viscosity-reduction purpose but leaves no harmful residue requiring desolvation, effectively substituting a harmful substance with a temporary process parameter change.

The patent extracts the harmful desolvation step entirely from the process by preventing organic solvent addition in the first place. By formulating the emulsion at elevated temperature without MIBK and xylene, the patent eliminates the need for subsequent solvent removal, thus removing the time-consuming and costly desolvation step while maintaining environmental benefits.

The patent performs preliminary viscosity reduction through temperature control during the emulsion formation stage itself, rather than relying on organic solvents that would require later removal. This preliminary action at the correct temperature stage achieves the desired handleability without creating a subsequent desolvation requirement, saving both time and cost.

The patent applies partial heating (50-100°C) rather than excessive high-temperature mixing, which is sufficient to reduce viscosity for handling but remains below the threshold that triggers significant epoxy-curing agent reaction. This partial action achieves the desired viscosity reduction while preventing the adverse viscosity increase from premature curing.

The patent performs the viscosity-reducing heating action preliminarily during emulsion formation, before the curing reaction significantly progresses. By establishing the correct temperature and viscosity conditions early in the process, the patent prevents subsequent viscosity increases from adverse reactions while maintaining stable composition throughout production.