Photochromic ink is also called chameleon.The color of printing products shows a pair of colors, example: red-green, green-blue, gold-silver, etc. Have the extremely strong reliability of security . So many countries in the world,it is designated for anti-counterfeiting in the most strict and most difficult of currency and securities .Some well-known domestic manufacturers also used for anti-counterfeiting packaging.
Photochromic Ink---classification
The photochromic ink have the widely application in the field of printing ink.According to its different uses it have water-based/ oil -based ink/ plastic ink/ interferometric ink / etc.
Photochromic Ink---Manufacturing methods
The manufacturing methods of this kind of ink , general dissolve photochromic pigment with the solvent,then made the miniature pigment capsules.In the dissolved pigment ,adding the adhesive according to different purposes. The best manufacturing method is to dissolve photochromic pigment and let it to be the overlap monomerput .Shattered this kind of polymer superfine particle, made into the powder,and use as the powder.Compared with the ink and ink miniature capsule which made by this methods ,the light fastness increase for 10 times.
printing ink and miniature capsule made of ink in this way, compared to 10 times more light fastness. These powders can adding into the water-based ink ,oil-based ink,plastic printing ink, and all kinds of glue as the pigments .
Photochromic Ink-Product application
(1) Photochromic water-based screen printing ink and water-based ink
Dominant in the fibre industry,with the advantage of safty use and easy operate . Using this kind of the water-based ink should use the the 80 ~ 120 mesh screen printing, after drying under 100 ℃ for 1 min) (best dry for overnight), dry again under 130 ℃ heat for 3 min bridging reaction, then you can get the excellent fiber products. The characteristics of the water-based ink are as follows:
Can quickly appear the color in the sun ,can restore colorless state in a short time after shading (different colors have the differences, yellow should after 2 ~ 3 min, cyan can be finished in a moment).
* good dispersion performance,can get the uniform color appering printing products;
* good color rendering and friction fastness;
* this water-based ink belong to liquid type ink;
* good storage stability, easy to operate
(2)Photochromic oil -based ink
(3)It is mainly used in surface printing of the plastic film, metal plate , etc.
This kind of ink use the 100 ~ 200 mesh silk screen printing . There are a lot of kinds of resin using in the adhesive: propylene, epoxy resin, amino ethyl formate, silicone modified resin, etc. As the esters, ketones etc of the solvent, oil, etc. In these composed of resin and solvent adhesive with light color changing materials, can be appropriately adjust the viscosity of screen printing ink, made oil-base screen printing ink.
(3)Photochromic plastic ink
According to the survey, the printing factory which production the Japanese using plastisol screen printing ink is very few. But in the country such as United States , especially the T-shirt production industry use the more printing ink. Plastic printing ink is a kind of ink which is not easy to dry, ordinary do not need to cleaning themesh plate.The ink remaining on the version , can also repeated used the next day. The plastic printing ink is using the DOP plasticizer to inflation the Superfine powder particles in the copolymer of vinyl acetat to make screen printing ink. Photochromic plastic ink can also add this plastic polymerizer to make screen printing ink. But when the features by photochromic material itselfl is restrained, and make it completely decomposed, this kind of phenomenon will show after a few days, therefore, it’s hard to use it as a commodity.
But if the plastic resin without the vinyl acetate copolymer, but use a kind of superfine powder material which have the same characteristics and can control the photochromic pigment , it would be an ideal photochromic plastic ink powder .
(4) interferometric ink
This kind of ink is the most complex one in modern anti-counterfeiting printing ink, is the popular high-tech products currently .Photochromic ink is a kind of reflective ink, has the pearl and the metal effect. Color copiers or the electronic copy machine also canl not copy it out. The printing products which printed out by photochromic ink, The color of printing products shows a pair of colors, example: red-green, green-blue, gold-silver, etc. Tilt the pattern to 60 ° , can make the pattern change from one color to another color . Due only when the ink film of the product is thicker, can appear the significant color drift phenomenon. So the printing is characterized can not be copied by any other ink or way of printing .