LCR Hallcrest Photochromic Ink Slurries are a mixture of microcapsules containing a water soluble solvent and a photochromic leuco dye plus water. The slurries are a thick ink.
A binding chemical is added to the ink slurries to aid in adhering the dye to surfaces.
The part of the PC leuco dye responsible for color is called a chromophore, which is attached to
When not exposed to UV light, the bent shape of the chromophore allows visible light to pass through, much like visible light passes through the glass in a window. Thus, the photochromic leuco dye molecules are transparent to visible light when not exposed to UV light. When exposed to UV light, the energy from the UV light causes the twisted closed figure-8 shape of the chromophore to open into a more planar shape. This open shape is an effective absorber of visible light. The part of the visible light spectrum not absorbed is reflected. The visible light spectrum is made up of seven colors, red, orange yellow, green, blue indigo and violet. The visible light reflected by the dye molecules is what you perceive as color. The size of the chromophore determines which part of the visible light spectrum is absorbed. When the source of UV light is removed, the PC molecules change back to their unactivated closed resting shape. The rate at which the dye molecules revert back to their resting shape dependent on ambient temperature as well as the chemical structure of the dye. The higher the ambient temperature the faster will be the fading of the PC molecules. Kinetic refers to motion and its cause. The dye kinetics of PC dye refers to all variables affecting the activation and fading speeds of the PC dye molecules. The photochromic effect of PC dyes depends on the physical twisting of the dye molecule’s ring structure. Visual light doesn’ t provide enough energy for this molecular change, but UV light does. PC dye in crystalline powder form are not affected by UV light because the dry molecules are unable to move. They need to be in some kind of medium that allows the PC dye molecules to physically change. This is accomplished by a process called microencapsulation; the PC dyes and a solvent are surrounded by a thin protective wall, much like air is surrounded by a film that forming a soap bubble. inside a bubble has a protective wall bubble has a soap film The microencapsulation process is the most versatile, widely applicable, and successful way of stabilizing, packaging, and protecting leuco dyes. Microencapsulation is the process by which the PC dyes are encapsulated. The PC slurry is a thick water soluble A wide range of Reversible PC products, from raw materials to finished inks, powders, dyes and finished products is available. A PC material can be custom synthesized or formulated specifically for your application, including a color to color change. LCR Hallcrest does not offer permanent change photochromic inks at this time. Please let us know if we can be of assistance in creating your custom product! Generally, LCR Hallcrest reversible photochromic inks can cycle from colorless to colored to colorless and so on thousands of times depending upon length of exposure time to UV light as well as the intensity of UV light. LCR Hallcrest has a wide range of available Reversible PC products, including powders, slurries and inks. Permanent change photochromic inks at not offered at this time, but a PC material can be custom synthesized or formulated specifically for you. This includes color to color PC inks, which is a mixture of a PC leuco dye and a colorant, such as acrylic paint. Please let us know if we can be of assistance in creating your custom product! CONTENTS OF KIT HOW WOULD I USE THIS INK? Photochromic Ink is particularly effective in transforming images. Probably the most interesting use of the ink is in combination with standard black & white permanent inks. The indoor image might be a graphic of birds in permanent ink. When the person walks outside, the UV light in sunlight causes the PC Inks to change, thus revealing all the different vivid colors of the birds. A school name and mascot drawing on a T-shirt is black and white indoors. But, outside in the sunlight the school colors fill accent and fill the mascot design. Even hidden messages can be added that only appear under UV light in sunlight or black lights. The use of the PC inks for arts and crafts are limited only by your imagination. DILUTION Dilute with water. Inks work when thinned. To keep a more opaque look, do not dilute. APPLYING INK Ink can be applied with a brush, pad, roller or used as a screen ink (silk screening). FINISHED LOOK Paint dries to a matte finish. Ink will not come o on skin. Use laminate or over varnish (spot or spray) for more glossy look. PAINT ON ANY SURFACE Best on absorbent paper and board substrates. Plastics, glass, wood, and ceramic all make good surfaces as well. DRYING Use hot air dryers or IR lamps set to a maximum temperature of 70°C/158°F. Air drying time varies depending on ink thickness. FADING UV light will break down the ink over time. CLEAN UP Photochromic ink is water based and can be cleaned with water only. 1 MAKING THE INK Mix all the contents of the binder bottle with the contents of the slurry bottle. This is a correct weight ratio of 1 to 1 and will make approximately 1/4 C photochromic screen ink. MIXING COLORS Photochromic ink colors can be mixed with other photochromic ink colors. The resulting mixed ink colors all become vibrant when taken outdoors or under any UV light source. Photochromic ink colors can also be mixed with normally colored acrylic house paint or artist’s quality acrylic paint. The result would be that only the photochromic ink color would change with UV light, leaving the original acrylic color behind. PHOTOCHROMIC INK Qty Size Slurry Color 1 50g Yellow Slurry 1 50g Binder 1 50g Blue Slurry 1 50g Binder 1 50g Red Slurry 1 50g Binder CONTENTS OF KIT With the contents of this kit you will be able to experiment with UV activated ink. Included in this trial kit are: Mixed{Red Photochromic Ink Blue Photochromic Ink Mixed{Blue Photochromic Ink Yellow Acrylic Paint NORMAL NORMAL OUTDOORS (UV RAYS) OUTDOORS (UV RAYS) Red photochromic ink and blue photochromic ink are mixed and dry clear at room temperature. Blue photochromic ink and yellow acrylic paint are mixed. The blue dries clear leaving only the yellow. When taken outside or under UV lamp (black light), red, blue and mixed purple colors appear. When taken outside or under UV lamp (black light), the blue photochromic ink and the mixed green appear as vibrant color. 2 Applications are only limited by the imagination! Personal Accessories Color changing stamped canvas tote. *Hint-Use stamp and mix photochromic ink and acrylic paint. The colors will magically appear outside. Also use a disappearing thermochromic ink and watch how the hot sun makes that change too! Art Projects White labels coated with clear purple photochromic ink turn purple when exposed to the sun. Great science project demonstrating Patio, Deck, and Garden Items. Hand painted tumblers and cups change colors before your eyes. *Hint-Use both acrylic paint and photochromic ink to keep color always showing through. APPLICATION IDEAS DESIGN CONCEPTS Activated by sunshine 3 See PDS 071 Rev 00 Photochromic Water Based Screen Ink for additional product information including cleaning and storage instructions. hallcrest.com, Glenview, IL 60026 SM143 Rev00 Activated by sunshine the effects of UV light.