Improved light fastness

Type of light (energy content including exposure time, rhythm of change from light to dark) 

Better LF with higher concentration and lower specific surface (pigment particles have better LF than molecular distributed dyes). Equal dye distribution over the fibre cross-section has better LF than ring dyeing with dyes concentrated near the fibre surface. 

Catalytic fading (another dye catalyses photodegradation), rarely also LF protection 

Identical disperse dyes on PES show better LF than on PA. Basic dyes on PAN have better LF than on meta aramide (for example Nomex). 

Better LF with lower water content. Defined humidity for LF testing 

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Dyeing. Supercritical fluid can be used to provide a water and solvent-free method of textile dyeing. Fluoro-modified dyestuffs have been developed in order to provide improved light-fastness etc. and are readily available. It might be interesting to research die supercritical fluid solubility of these products.23-27... 

Troubleshooting finishes that improve light fastness... 

Excellent compatibility Improves wet and dry crock Improves light fastness Excellent color yield Applicable on a variety of fabrics... 

The introduction of a trifiuoromethyl group into the molecule of an aromatic amine gives improved light-fastness coupled with brightness of shade to the pigment, as demonstrated by Fast Scarlet VD Salt, (8). Derivatives of mono acetjdated paraphenylenediamine such as Fast Blue BB Base, (9), are particularly useful for blue shades. 

Sulphur dyes are after-treated with copper sulphate or, more commonly, with copper sulphate together with potassium or sodium dichromate and acetic acid. The treatment improves light-fastness and, in some cases, wash-fastness, to a small extent. When copper sulphate alone is used the process consists of running, after rinsing, at 70°C (160°F) for 20 to 30 minutes in a liquor containing... 

Before hand testing of light stabilizing activity of DTIU while introducing it into a polymer as mechanical additive was carried out. Data of Table 24 show that DTIU possesses photostabilizing activity that gives the reason to consider the fact that its condensation with CDA will improve light fastness of the latter. 

Uniplex 80 is economical both on a cost and a performance basis, while exhibiting excellent compatibility with a wide range of polymers, cellulosics, and resins. Resins plasticized with Unlplex 80 exhibit Improved light-fastness and low toxicity. 

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