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Photochromic

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
Colored

 B. Colors: #12 Purple, #13 Sky blue, #14 Blue, #16 Yellow, #17 Orange, #19 Magenta, #22 Gray

One color (RA) for conventional Zinc Sulfide) powder

 

 #12 Purple           #13 Sky Blue            #14 Blue            #16 Yellow            #17 Orange            #19 Magenta            #22 Grey

 

3. Applications

A. Available Products & Applicability

B. Photo chromic dye

a. Product description
Photo chromic 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 photo chromic 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(0.1%)
(For the best result, about 0.1% concentration is required for 20um film thickness)
For plastic injection/extrusion 0.01%~0.3% w/w(0.01%)
(For the best result, 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 photo chromic dye cannot be injection molded at temperatures over 250℃ due to its low decomposition temperature.
The solvent compatibilities of photo chromic dyes are different. There are standard formulations available for ink/paint applications. Please contact sales department for more information.
Please link to technical data sheet for more information about solvent compatibility.

C. Photo chromic Slurry

a. Product Description
Photo chromic slurry is microcapsulated aqueous dispersion with good dispersal in water, suitable for water based paint. It contains 48% of solid content. The average particle size of the slurry is 3-7µm.

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(25%)
(For the best result, about 25% concentration is required for 20µm film thickness)

d. General Recommendations
Slurry may clump together during storage, which can be heated with a double boiler to disperse.
Avoid high polarity solvents, which will affect the microcapsules’ content through permeation.

D. Photochromic Microcapsulated Powder

a. Product Description
Photochromic microcapsulated powder contains 2% of photochromic dye and less than 3% of moisture, suitable for solvent based ink/paint and plastic injection/extrusion. The average particle size is 3-12µm.

b. Properties
Photochromic microcapsulated powder is pigment, which is colorful, high temperature resistant, and solvent resistant, suitable for plastic injection and solvent based ink/paint.

c. Recommended Concentrations
For solvent/ aqueous based ink/paint 3% ~30% w/w(25%)
(For the best result, about 25% concentration is required for 20µm film thickness)
For plastic injection/extrusion 0.2% ~1% w/w(0.5%)
(For the best result, 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 PS Powder

a. Product Description
Photochromic PS powder comprises of 1.5% photochromic dye and 98.5% PS plastic. The mixture is molded and then grinded into the powder. It can withstand processing temperatures ≦180℃, containing moisture≦0.5%, suitable for solvent based ink/paint.

b. Properties
Photochromic PS powder is pigment with property of easy dispersal, that can be directly applied to solvent based ink/paint.

c. Recommended Concentrations
For ink/paint 5%~30% w/w(25%)
(For the best result, about 25% concentration is required for 20µm film thickness)
For plastic injection/extrusion 1% ~5% w/w(0.5%)
(For the best result, about 0.5% concentration is required for 0.2cm plastic thickness)

d.General Recommendations
The compatibility between PS powder and formulations should be always considered.

F. 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(1%)
(For the best result, about 1% concentration is required for 0.2cm plastic thickness)

d. General recommendations
Standard masterbatch is PE masterbatch. Please check the properties of PE for applications.
Photochromic masterbatch is made with special formulations. Its color changing effect is different from the effect of photochromic powder or 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.

5. Others

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

B. Safe for food grade packing and toys.