OPTICAL BRIGHTENER FOR CELLULOSE FIBRES

AVCO-LUX NMA produces very brilliant optical brightening effects with a redish violete shade on cellulose fibres. AVCO-LUX NMA is an optical brightener with low to medium fibre affinity. It is therefore particularly suitable for application by the padding method. It can be applied by the exhaust method, with excellent good brightening effects in the presence of salt.

SPECIFICATIONS:

Appearance	Clear brownish liquid with fluorescence hue.
Chemical nature	Sulphonated stilbene derivative in aqueous solution.
Density (g/cc)	1.12 – 1.16
Ionicity	Anionic
Solubility	Soluble in water at any ratio.
pH (10%)	8.0-10.5
Shade on fibres	Reddish violet white
Compatibility	Is not compatible with strong acids and cationic products
Storage	Sensitive to frost. Shelf life is at least 12 months.

Stability in application baths:

Electrolytes: very good

Peroxide: very good

Hypochlorite: not stable

Sodium chlorite: not stable

Reducing agents: very good

pH stability (at 3.5-12) very good

Resin finishing: very good

Alkali: very good

Fastness properties on cellulose fibres:

1. Light fastness 3 – 4

2. Washing fastness at 40°C very good

3. Acid fastness very good

4. Alkali fastness very good

5. Perspiration fastness, acid very good

6. Perspiration fastness, alkaline very good

7. Fastness to hypochlorite bleaching good

8. Fastness to peroxide bleach very good

9. Fastness to hydrosulfite bleach very good

10. Fastness to dry heating (30 sec./180°C) very good

PROPERTIES & USES:

1. AVCO-LUX NMA is an optical brightener for cellulosic fibres with brilliant reddish violet white shade.

2. AVCO-LUX NMA has low to medium affinity to the cellulosic fibres, with outstanding build-up and excellent levelling properties.

3. AVCO-LUX NMA has a good acid stability in the application bath down to pH=3.5. No risk to acidification of textiles pretreated in alkaline bath.

4. Very good stability to peroxides, reducing agents, alkali and electrolytes.

5. AVCO-LUX NMA produces attractive white effects when applied by padding or by exhaustion in peroxide bleach baths.The low affinity may be an advantage since it helps to prevent from tailing in goods finished by padding or in the jig machine.

6. By adding salt to the finishing liquor, the affinity of AVCO-LUX NMA can be adjusted as required.

7. AVCO-LUX NMA produces excellent white effects when applied in resin finishing, especially together with reactive resins. The finish can be cured by either the conventional method or shock condensation.

8. AVCO-LUX NMA is a versatile brightener which can be used in handle finishing baths together with starch, synthetic resin dispersions provided the ionic properties permit it. The excellent compatibility with other polyester brighteners enables one step application in the wash and wear finishing of blends of polyester/cotton and polyester/rayon.

9. AVCO-LUX NMA is a pumpable liquid product, which can be mixed easily in the finishing bath.

APPLICATION:

Typical examples of the application of AVCO-LUX NMA to cellulosic fabrics.

1. Padding process:

Cellulosic fabrics: AVCO-LUX NMA: 2 – 8 g/l

Liquor pick up app. 70-80%

2. Exhaustion process:

Apply the optical brightener together with electrolyte.

Use the following recipe:

AVCO-LUX NMA 0.5 – 2.0%

Sodium sulfate 2.0 – 5.0 g/l

Temperature: 30 – 60°C

Treatment time: 20 – 30 minutes.

3. Application in the bleaching bath:

AVCO-LUX NMA can be applied also in a peroxide bleaching bath at the usual treatment temperature and time.

AVCO-BLANKINOL VLF 3 – 4 g/l

H₂O₂ (50%) 6 – 10 cc/l

AVCO-LUX NMA 0.5 – 1.5 %

Sodium sulfate 1 – 3 g/l

Bleach for 45-60 min. at 80-100°C.

4. One step easy care finishing and optical brightening of white fabrics:

AVCO-REZ ECO-CONC 40 – 80 g/l

AVCO-CATALYST PMC 20 – 40 g/l

AVCO-ELASTOGUM 100 10 – 30 g/l

AVCO-SOFT PE 20 – 40 g/l

Acetic acid (60%) 0.2- 0.5 cc/l

AVCO-LUX NMA 5 – 15 g/l

Pad at liquor pick up of 60-90% dry at 110-130°C and cure for 3-5 minutes at

150-155°C.