1. R series thermochromic pigments are suitable for injection molding and extrusion:

R series (plastic grade) is a color-changing pigment variety developed by our company specifically for plastics. Its characteristics are: thick capsule wall, high strength, good heat resistance, easier to disperse evenly, and less residual color when decolorizing.

2. Scope of application:

This product can be used for injection molding and extrusion molding of transparent or translucent plastics such as polyethylene (PE), polypropylene (PP), polystyrene (PS), soft polyvinyl chloride (S-PVC), AS and ABS. It can also be mixed with unsaturated polyester, epoxy resin, organic glass or nylon monomer for casting, molding and curing.

3. Dosage:

When used for injection molding, extrusion processing or casting, molding, curing molding, the amount of color-changing pigment is 0.4~3.0% of the amount of plastic, usually 0.6~2.0%. The color-changing pigment and plastic particles should be fully mixed evenly (a small amount of white oil can be used during mixing). If ordinary pigments and color-changing pigments are used, the amount of ordinary pigments (or dyes) is about 0.5-2.5% of the color-changing pigments.

4. Color matrix:

In mass production, the color-changing pigment can be added to polyethylene wax or polystyrene wax to make a masterbatch with a pigment content of 10%, and then mixed with plastic particles. This can make the color-changing pigment disperse more evenly. The preparation method of the masterbatch can refer to the technical information provided by our company.

5. Temperature:

The processing temperature should be controlled below 200℃, and should not exceed 230℃, and the heating time of the material should be minimized. (High temperature and long-term heating will damage the color-changing properties of the pigment).

6. Notes:

A: When using color-changing pigments in injection molding and extrusion, other fillers or common pigments (such as titanium dioxide, calcium carbonate, barium sulfate, carbon black, etc.) should not be used in the plastic at the same time, otherwise the color-changing effect will be blocked.

B: When using color-changing pigments in casting, molding, and curing, the color-changing pigments should first be added to unsaturated polyester, organic glass, or nylon monomers and stirred and dispersed evenly, and then the initiator or curing agent is added to start polymerization or cross-linking reaction. Because the viscosity of the system increases sharply after prepolymerization, adding color-changing pigments at this time will cause a large number of pigment particles to be wrapped together, making it difficult to disperse evenly. In addition, the stirring operation at this time will also leave a large number of bubbles in the system.

C:Choose the crosslinker or curing agent carefully:During the cross-linking and curing process of epoxy resin and unsaturated polyester resin, strong shrinkage stress is sometimes generated inside, causing the shell of the color-changing pigment microcapsule to rupture and other chemicals to enter the pigment, causing it to lose its color-changing properties. This situation often occurs when the epoxy resin curing thickness is greater than 0.2 mm and a polyamine curing agent is used.

D:Internal mixers, kneaders, high-speed dispersers, and twin-screw extruders cannot be used.High shear equipment such as granules and pigments are used to pre-mix plastic particles. These equipment will seriously damage the protective layer on the surface of the pigment, causing it to lose its color-changing properties. In addition, when preparing the masterbatch, the pigment should be prevented from being subjected to repeated extrusion and granulation operations.

E: Avoid using phosphorus-containing stabilizers and plasticizers in the formulation of PVC resin, otherwise the color-changing injection molded products will have serious residual color when in the decolorized state.