1. Introduction

The photochromic product changes colors when exposed to sunlight/UV, and reverts to its original color when the sunlight/UV is dimmed or blocked. After absorbing the energy of sunlight/UV, its molecule structure is changed, which causes its absorbed wavelength to be changed allowing a color to appear. It reverts to the original molecule structure and color when the light stimuli is dimmed or blocked.

2. Product Description

A. Color Conversion:

From colorless to colored

colorless(without UV)

colored(with UV)

B. Colors:

#12 Purple, #13 Sky blue, #14 Blue, #16 Yellow, #17 Peach Orange, #18 Orange, #19 Magenta, #22 Gray

#12 Purple	#13 Sky Blue	#14 Blue	#16 Yellow
#17 Peach Orange	#18 Orange	#19 Margenta	#22 Grey

3. Applications

A. Available Products & Applicability

B. Photochromic dye

a. Product Description

Photochromic dye does not react to sunlight/UV and need to be dissolved in a medium (solvent, resin, or polymer) to function. Polarity of the medium is directly related to the color.

b. Properties

The photochromic dye is an organic dye completely pervious to light, suitable for plastic injection and solvent based ink/paint.

c. Recommended Concentrations

For solvent based ink/paint            0.02%~0.3% w/w
(For best results, about 0.1% concentration is required for 20um film thickness)

For plastic injection/extrusion           0.01%~0.3% w/w
(For best results, about 0.01% concentration is required for 0.2cm plastic thickness)

d. General Recommendations

Overexposure to sunlight, acids, free radicals and humidity may cause poor fastness, which could be improved by adding UV absorbents or anti-oxidants. Specific formulations of UV absorbents or anti-oxidants should be used depending on the media. Improper formulations speed destroying color fastness and end up destroying the color changing properties.

The photochromic dye can not be injection molded at temperatures over 250℃ due to its low decomposition temperature.

The solvent compatibilities of photochromic dyes are different. There are standard formulations available for ink/paint applications. Please contact sales representatives for more information.

Please link to http://www.colorchange.com.tw/ for more information about solvent compatibility.

C. Photochromic Slurry

a. Product Description

Photochromic slurry is microencapsulated aqueous dispersion with good dispersal in water, suitable for water based paint. It contains 45%(±5%) of solid content. The average particle size of the slurry is 3-10µm.

b. Properties

Photochromic slurry protected by microcapsules can change colors steadily, and does not be affected by extreme environment.

c. Recommended Concentrations

For aqueous based ink/paint         　　　　　5%~60% w/w
(For best results, about 25% concentration is required for 20µm film thickness)

d. General Recommendations

Slurry may gather together during storage. Heating the slurry to 45℃ in a double boiler to disperse.

Avoid any high polarity solvents since the microcapsules may be permeated and their contents may be affected.

D. Photochromic Microcapsulated Powder

a. Product Description

Photochromic microencapsulated powder contains 2~5 % of photochromic dye and less than 3% of moisture, suitable for solvent/aqueous based ink/paint and plastic injection/extrusion. The average particle size is 3-10µm.

b. Properties

Photochromic microencapsulated powder is a pigment, which is heat and solvent resistant. The powder shows brilliant color when exposed to sunlight/UV. Suitable for plastic injection and solvent based ink/paint.

c. Recommended Concentrations

For solvent/ aqueous based ink/paint　　　　　      3% ~30% w/w
(For best results, about 25% concentration is required for 20µm film thickness)

For plastic injection/extrusion　　　　　          0.2% ~1% w/w
(For best results, about 0.5% concentration is required for 0.2cm plastic thickness)

d. General Recommendations

Added heat stabilizer and processed at temperatures not higher than 230℃ when applied to plastic injection/extrusion.

E. Photochromic Masterbatch

a. Product Description

Photochromic masterbatch is made by injection molding of 1% photochromic dye, 99% plastic, UV stabilizer and anti-oxidants.

b. Properties

Dispersed and used easily, can be directly applied to plastic injection/extrusion.

c. Recommended Concentrations

For plastic injection/extrusion　　　　　            1% ~5% w/w
(For best results, about 1% concentration is required for 0.2cm plastic thickness)

d. General Recommendations

Standard masterbatch is PE masterbatch.

Photochromic masterbatch is made with special formulations. Its color changing effects are different from the effects of photochromic powder and dye.

4. Miscellaneous

A. Colored to colored

B. All the NCC photochromic products, except the photochromic dyes, are in pigment forms, which can provide various levels of coverage effects.

C. The light fastness of the photochromic products should be thoroughly tested prior to approval for production.

D. Light fastness can be improved by adding more photochromic materials.

5. Others

A. Storage: Keep sealed in a dark, cool place, away from direct sunlight. Best within two years if stored correctly.

B. Certifications: EN-71 & RoHS passed. Safe for food grade packing and toys.