Groundbreaking innovation in colorants for plastics has enabled personal care
maker Conair Corp. (Stamford, CT, U.S.) to manufacture hair dryers that display
brilliant iridescent effects previously only found in nature. Using new Variocrom™ color-variable
pigments developed by BASF
Corp., Teknor Color (Pawtucket, RI, U.S.) has produced
concentrates that impart to the Conair dryers a shimmering, kaleidoscope play
of bright colors that merge from one into another as the viewing angle changes.
The hair dryers are the first North American application of the BASF technology.
"While the hand-held hair dryer pioneered by Conair has long since become
an everyday necessity for people around the world, striking design and color
as important for this appliance as functionality," says Paulette Heller,
director of Marketing for Conair. "By bringing an exciting new visual
flair to our hair dryers, color-variable effects make them stand out from other
personal care products and add a new dimension of enjoyment to everyday use."
key to these effects is the development by BASF of formulations of pigment
flakes or platelets that, in plastics processing, form multi-layer structures
whose reflection, refraction, and interference properties yield what BASF describes
as "angle-dependent color play." Teknor Color developed concentrates
that incorporate this complex optical system and worked with Conair to maximize
economy in using the concentrates.
Dramatic Special Effects
The effects provided by the new Variocrom pigments
differ from conventional angle-dependent or "flip-flop" effects in
the intensity of their colors and the complexity of their shifting hues, according
to Jennifer Bailey,
BASF account manager. "For precedents, the scientists who developed our
new pigments have pointed to the brilliantly iridescent shells of exotic insects
like the rose beetle, and to the constantly changing colors in soap bubbles," Ms.
Intrigued by the new pigments, Teknor Color brought them to the
attention of George Murray, Jr., Conair's director of Tooling and Plastics
on its experience with other flip-flop pigments containing platelets that cause
color shifts with changes in viewing angle, Teknor Color developed concentrates
that maximize the special effects of the Variocrom pigments at minimal loadings," Mr.
Murray says. "They accomplished this without compromising other color
Based on technology developed in Germany 2 years ago
by BASF AG, Variocrom pigments come in four colors: Magic Gold, Magic Red,
Magic Purple, and Magic
Green. The intensity of the color-variable effect depends on the clarity of
the natural resin used, and the shift in hue is most pronounced in large parts
with multiple curves. "These can be combined with organic pigment and
dyes to produce an infinite variety of colors," says Ms. Bailey. "Possibilities
range from dramatic color shifts, such as from rose to green, to many kinds
of subtle effects. For example, a part might be transparent when viewed at
an angle of 90 degrees, colored at 15 degrees, and opaque at 180 degrees."
"The eye-catching effects are particularly attractive to people in the
15- to 30-year-old category," notes Ms. Bailey. She says that all Variocrom
pigments are approved by the U.S. Food and Drug Administration for food-contact