Clevertex - Grado Zero Espace Srl

2.2.5.2 Patents published
Toray Industries, Inc., published a patent for the production of a photochromic spiro-oxazine
compound that is valuable as a photochromic printing material for clothing and decorative articles
under US 4784474 in 1988.
In US 6 749 935 B2 a temperature-sensitive colour-changeable composite fibre produced by the
Japanese company The Pilot Ink Co., Ltd, is described. The sheath-core-type structures are imposed
by constraints on spinning conditions set by the thermal sensitivity of microcapsules. The sheath is
made of a high-melting fibre-forming polymer (e.g. polyester or polyamide), and the core consists of a
dispersion of microcapsules (5 to 20 µm) with epoxy/amine resin walls in a low melting matrix (e.g.,
polyolefin, polyamide, or polyester). Due to that sensitivity, the sheath must cover at least 80 percent
of the fibre’s surface and constitute 25 to 90 percent of the fibre’s weight.
The patent is based on another patent applied by Pilot Ink from 1977, US patent 4028118. In this
patent the production of a thermochromatic material exhibiting a reversible metachromatism within a
temperature range from -40°C to 80°C is described. The material can be processed into
microcapsules or into thermochromic printing inks.
2.3 Optical fibres
2.3.1 Description
A material that is not primarily associated with textiles is glass. However, fabrics comprising glass
fibres are used for interior textiles as they are capable to reflect and filter light and additionally they
resist mould/ funghis and moths. But, disadvantageously, they have the tendency to irritate the skin, a
property that makes it difficult to apply them in fashion [5].
Fibres of glass are often referred to as optical fibres, usually about 120µm in diameter, which are used
to carry signals in the form of pulses of light over distances up to 50 km without the need for repeaters.
These signals may code voice communications or computer data.
Interest in the use of light as a carrier for information grew in the 1960's with the advent of laser as a
source of coherent light. Initially, the transmission distances were very short, but as manufacturing
techniques for very pure glass arrived in 1970, it became feasible to use optical fibres as a practical
transmission medium. At the same time developments in semi-conductor light sources and detectors
meant that by 1980 world wide installation of fibre optic communication systems had been achieved.
Fields of application:
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