Water-Soluble Thermoset Binder for Cemented Carbide 3D Printing

The patent changes the chemical parameters of the binder system by using specific compounds with defined molecular weights (less than 2000 g/mol) and functional groups (hydroxyl and carboxyl groups). The molar ratio of hydroxyl to carboxyl groups is controlled between 0.1 and 10, which optimizes the crosslinking reaction to achieve adequate green strength while minimizing porosity formation during curing.

The invention creates a composite binder system combining compound A (with hydroxyl groups) and compound B (with carboxyl groups) in specific proportions (30-80 wt% total). This composite approach allows the binder to provide sufficient green strength for handling while the controlled chemical reaction produces a more uniform structure with reduced porosity in the sintered body.

The patent replaces hazardous epoxy binders with biodegradable, non-toxic compounds derived from natural sources. The binder system uses compounds without nitrogen, phosphorous, silicon, potassium, sodium, or fluorine, making it environmentally friendly and safe for handling while still providing adequate green strength for the application.

The invention changes the chemical composition parameters by selecting compounds with specific functional groups (hydroxyl and carboxyl) and molecular weights (less than 2000 g/mol). This parameter optimization allows the binder to achieve sufficient adhesion and green strength without relying on hazardous epoxy chemistry, thus improving environmental and health safety.

The patent optimizes the concentration parameter by using compounds with low molecular weights (less than 2000 g/mol) and specific functional groups that enable high solubility in water. This allows the binder to be formulated at high concentrations (30-80 wt% total compounds) without requiring large amounts of solvent, thereby achieving both high green strength and environmental safety.

The invention creates a composite binder system where compound A and compound B work synergistically. The combination of hydroxyl-containing and carboxyl-containing compounds creates extensive hydrogen bonding and crosslinking, which provides high green strength even at high binder concentrations, eliminating the need to dilute with large amounts of solvent.

The patent applies preliminary action by adding the binder to the powder mixture before printing, allowing the binder to penetrate and bond the particles during the printing process. The binder is incorporated into the green body structure before depowdering occurs, ensuring that the bonded particles maintain their strength even when exposed to cleaning fluids during the depowdering stage.

The invention changes the chemical reactivity parameter by using compounds that undergo controlled crosslinking reactions. The hydroxyl and carboxyl groups react to form ester bonds and crosslinked structures, creating a chemically bonded network that provides durable green strength. This chemical bonding maintains strength during depowdering unlike purely physical entanglement mechanisms.