Low Temperature Optical Brightener
Fluorescent brightener for polyester fibres and their blends.
Nature: Styrylbenzene derivative, nonionic.
Storage: When stored correctly in sealed containers, the product has a shelf life of up to 24 months. The dispersion should be well stirred before removal from containers.
Properties: Yellowish dispersion, miscible with cold water in all proportions. Depending on dosage, the white effect can range in reddish/bluish tone. The product is stable in reductive bleaching liquors and those containing hydrogen peroxide or sodium hypochlorite. Unfixed product/fabric should be protected from light. Its high yield allows brilliant white effects even at low dosage. A carrier is required for exhaust processing at the boil; it is less suitable for CA, CT and PA.
0.1–0.5% Ultrashine LT Liquid 0.5–1 g/l dispersing agent pH 4.5–5.5 (acetic acid); liquor ratio 5:1 to 20:1 Starting temperature: approx. 50–60°C; heat to 130°C; 30–45 min at 130°C. A dispersing agent is particularly important for wound packages.
0.1–0.5% Ultrashine LT Liquid Carrier as recommended by manufacturer 0.5–1 g/l dispersing agent pH 4.5–5.5; liquor ratio 10:1 to 20:1 Temperature: 98–105°C; time: 45–60 min.
0.5–5 g/l Ultrashine LT Liquid Liquor pick-up: approx. 60–70% Dry: approx. 120°C Thermosol: 180–200°C; approx. 30–15 seconds. Fixation depends on fabric construction; heavier/tighter fabrics may require longer time or higher temperature. Protect padded/dried fabric from prolonged light before fixation.
Equipment has a considerable influence on fixation time and temperature. Conditions based on plant experience are preferred; preliminary trials are recommended. Product dosage is the same as for the two-stage process.
The product can be fixed under resin-finishing and other finishing conditions. Fluorescent brightening of print grounds is frequently carried out with the thermosol process; texturised PES knit goods can also be brightened by HT processing.
| Printing system | Medium | Temperature | Time | White effect |
|---|---|---|---|---|
| Disperse dyes | HT steam | 160–170°C | 8–10 min | No impairment |
| Disperse dyes | Hot air | 200°C | 6 min | No impairment |
| Pigment dyes | HT steam | 160°C | 3 min | No impairment |
| Pigment dyes | Hot air | 175°C | 6 min | No impairment |
Values below refer to the change in white effect on PES at an optimum standard of white.
| Light (Xenotest), DIN 54 004 | 5–6 |
|---|---|
| Washing at 40°C, DIN 54 014 | 5 |
| Washing at 60°C, DIN 54 010 | 5 |
| Seawater, DIN 54 007 | 5 |
| Perspiration — alkaline, DIN 54 020 | 5 |
| Perspiration — acid, DIN 54 020 | 5 |
| Dry cleaning, DIN 54 024 | 5 |
| Dry heat pleating/setting 180°C, DIN 54 060 | 5 |
| Dry heat pleating/setting 210°C, DIN 54 060 | 4–5 |
| Oxides of nitrogen, DIN 54 024 (E) | 5 |