Sodium perborate, detergent

Many metal borates find important industrial applications (p. 140) and annual world production exceeds 2.9 million tonnes Turkey 1.2, USA 1.1, Argentina 0.26, the former Soviet Union 0.18, Chile 0.13Mt. Main uses are in glass-fibre and cellular insulation, the manufacture of borosilicate glasses and enamels, and as fire retardants. Sodium perborate (for detergents) is manufactured on a 550 000 tonne pa scale. 

World production expressed as 100% H2O2 approached 1.9 million tonnes in 1994 of which half was in Europe and one-fifth in the USA. The earliest and still the largest industrial use for H2O2 is as a bleach for textiles, paper pulp, straw, leather, oils and fats, etc. Domestic use as a hair bleach and a mild disinfectant has diminished somewhat. Hydrogen peroxide is also extensively used to manufacture chemicals, notably sodium perborate (p. 206) and percarbonate, which are major constituents of most domestic detergents at least in the UK and Europe. Normal formulations include 15-25% of such peroxoacid salts, though the practice is much less widespread in the USA, and the concentrations, when included at all, are usually less than 10%. 

Sodium perborate is used in laundry detergents and bleaches. It releases more hydrogen peroxide than borax when it reacts with water. Hydrogen peroxide acts as a bleach, and its action is aided by the alkaline solution that is also produced by the reaction. 

Aftertreatment with detergent (2-5 g/1) and sodium carbonate (2-5 g/1) often enhances whiteness and may improve fabric absorbency, particularly if the goods have not been scoured before bleaching. Antichlor treatment is unnecessary for white goods but may be required before coloration. A convenient antichlor treatment involves combining the detergent aftertreatment with sodium perborate, percarbonate or thiosulphate [143]. Traditional reductive antichlors such as sodium bisulphite are not recommended, since their residues can be just as troublesome as chlorite residues. 

The instability of DAST-type brighteners towards chlorine-containing bleaches has been mentioned already. They also show limited stability towards per-acids. As recommended washing temperatures have tended to fall in recent years, a bleach consisting of sodium perborate activated by addition of tetra-acetylethylenediamine (11.63) has become an important component of household detergent formulations. This system is effective at temperatures as low as 40-50 °C. Since the FBA may be sensitive to the activated oxidant, however, in some formulations it is necessary to protect compounds such as 11.60 or 11.61 by encapsulating either the brightener or the activator, if adequate shelf-life is to be maintained. 

Sodium perborate trihydrate in detergent formulations, 8 419 Sodium perbromate, 4 335 Sodium percarbonate, 28 413 Sodium perchlorate, 6 133... 

Sodium perborate has been for some time in use mixed with soap, borax, alkali, etc., and is sold for laundry work under such names as Persil, Glarax, and Ozonite. It possesses detergent and bleaching properties. Since 1914 the salt NaBOj, 4H20 has been produced by electrolysis, and many recent patents deal with this process. Formerly, the only means available for preparation was that of mixing borax with hydrogen peroxide. 

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