thermochromic dye

Fabric is one of the more demanding substrates for thermochromic chemistry. The dye has to survive wash cycles, flex without cracking, bond to fiber structures that weren't designed to hold encapsulated colorants, and still deliver a clean, repeatable color transition. That's a tighter brief than most people expect when they first start sourcing.

Textile printing puts unique demands on color-change systems. The ink or paste has to survive washing, stretching, heat-press cycles, and direct skin contact — and the thermochromic response still needs to be crisp and repeatable after all of that. These pigments are microencapsulated leuco-dye systems: a color former, a developer, and a solvent coencapsulated in a polymer shell that protects the active chemistry from the binder matrix. The shell integrity is what separates a pigment that lasts through 50 wash cycles from one that fades after five.

KTP-30-VB is a Purple-to-Blue thermochromic pigment with a 31°C activation temperature in the fine 3–10μm particle size range — a Colored-to-Colored (C2C) microencapsulated leuco dye pigment that transitions from purple below 31°C to blue above 31°C in response to body temperature or warm contact. 

KTP-30-BR is a Black-to-Red color-changing thermochromic pigment with a 31°C activation temperature in the fine 3–10μm particle size range — a microencapsulated leuco dye pigment that shifts from black below 31°C to red above 31°C, producing a two-color visual transition triggered by body temperature or warm contact. 

KTP-18-BY is a Yellow thermochromic pigment with an activation temperature of 18°C, in the fine 1–10μm particle size range — a microencapsulated leuco dye pigment that is yellow below 18°C and becomes colorless as temperature rises above the threshold. 

KTP-16-BR is a Red thermochromic pigment with an activation temperature of 16°C, in the fine 1–10μm particle size range — a leuco dye-based color-changing pigment that is red below 16°C and becomes colorless as temperature rises above the activation threshold.