Dishwasher Detergent

Sodium peroxoborate hexahydrate is an important ingredient of many household detergents, working best at temperatures above 60°C. It is also used in dishwasher detergents, denture cleaners, as well as foot and bath salts. The textile industry generally uses hydrogen peroxide for bleaching, but there are a few areas in which sodium peroxoborate hexahydrate is preferred. 

About 264,000 metric tons of elemental capacity is available in North America, plus another 79,000 t (P equivalent) of purified wet phosphoric acid (14). About 85% of the elemental P is burned to P2 5 hydrated to phosphoric acid. Part of the acid (ca 21%) is used direcdy, but the biggest part is converted to phosphate compounds. Sodium phosphates account for 47% calcium, potassium, and ammonium phosphates account for 17%. Pinal apphcations include home laundry and automatic dishwasher detergents, industrial and institutional cleaners, food and beverages, metal cleaning and treatment, potable water and wastewater treatment, antifree2e, and electronics. The purified wet acid serves the same markets. 

The use of chlorinated trisodium phosphate is declining. It has been largely replaced by chlorinated isocyanurates in powdered abrasive cleansers and automatic dishwash detergents to reduce cost, improve performance, or comply with restrictions on the use of phosphates. Some chlorinated trisodium phosphate is stiU used in commercial laundries and in disinfectant cleaners. 

Economic Aspects. Sodium hypochlorite—trisodium phosphate complex was commercialized in 1930. Chlorinated TSP is manufactured by Stauffer (a subsidiary of Rhc ne-Poulenc, Inc.). The consumption, steadily decreasing since 1980, dropped sharply in 1985 because of reduced use in dishwasher detergents. The estimated demand in 1987 was 37,360 t (220). In 1988 it sold for 0.32/lb ( 0.70/kg) for tmddoad quantities of 660 kg (300-lb) dmms. 

Appllca.tlons. The principal uses are in scouring cleansers and acid metal cleaners for dairy equipment. Use in dishwasher detergents has been supplanted by chlorinated isocyanurates, which are more cost-effective, more stable in hot water, and possess water softening properties. 

Other Clay Uses. Other appHcations for clays include use as a suspending agent, eg, montmorillonite and attapulgite in Hquid fertilizers and dishwasher detergents in pharmaceuticals (qv), eg, kaoHnite and attapulgite for diarrhea control in cosmetics, montmorillonite and attapulgite and in water impedence where bentonite linings are used for reservoirs and waste disposal areas. 

Phospha.tes, Pentasodium triphosphate [7758-29-4] sodium tripolyphosphate, STPP, Na P O Q, is the most widely used and most effective builder in heavy-duty fabric washing compositions (see also Phosphoric acid and phosphates). It is a strong sequestrant for calcium and magnesium, with a p c of ca 6, and provides exceUent suspending action for soils. Because of its high sequestration power, it also finds extensive appHcation in automatic-dishwashing detergents. Sodium tripolyphosphate forms stable hydrates and thus aids in the manufacture of crisp spray-dried laundry powders. 

Due to their favorable solubility, alkanesulfonates are preferred as surfactants in liquid products and concentrates. The recent trend to renewable resources has led to a somewhat reduced use in formulations of household detergents in past years. While some manufacturers have withdrawn these surfactants from, for example, manual dishwashing detergents, others did not. Besides many other industrial applications, alkanesulfonates are one of the most important emulsifiers in vinyl polymerization. 

Human skin compatibility has a high priority in manual dishwashing detergents. Recently, it was shown that there are some new possibilities to lower the Zein number by intelligent formulations. The Zein number is a common measure of the denaturation of protein under controlled conditions [84], A better... 

TABLE 26 Changes in the Surfactant Composition of German (European) Manual Dishwashing Detergents... 

TABLE 27 Typical Composition of a Manual Dishwashing Detergent Containing Alkanesulfonates... 

TABLE 28 Alkanesulfonates in Concentrated Dishwashing Detergents (50 wt % active matter)... 

Sodium dodecylbenzenesulfonate is undoubtedly the anionic surfactant used in the greatest amount because it is the basic component in almost all laundry and dishwashing detergents in powder and liquid forms. However, alcohol and alcohol ether sulfates are the more versatile anionic surfactants because their properties vary, with the alkyl chain, with the number of moles of ethylene oxide added to the base alcohol and with the cation. Consequently, alcohol and alcohol ether sulfates are used in almost all scientific, consumer, and industrial applications. 

Ammonium and alkanolamine alcohol sulfates are used in household formulations in light-duty liquids, manual dishwashing detergents, and liquid house-... 

Alcohol ether sulfates are used in mixture with sulfonates, either alkyl-benzenesulfonates or a-olefinsulfonates, and other surfactants, such as fatty alkanolamides, in manual liquid dishwashing detergents and light-duty detergents. These combinations show the excellent emulsifying and foaming properties required in dishwashing. 

Although IOS have not yet appeared in commercial formulations, several patents have claimed their use in LDLs and in other cleaning formulations. As an example, Kok et al. [8] have described the use of IOS containing 75% (3-hydroxysulfonate in a dishwashing detergent. Their patent also claims the use of IOS in granular and in liquid laundry detergents as well as in all-purpose cleaners. 

A great number of detergent compositions using a-sulfo fatty acid esters are given in the patent literature. The a-ester sulfonates are major or minor components, besides other surfactants and builders [68-76]. Some examples of laundry and dishwashing detergents are given below. 

Cutinase is a hydrolytic enzyme that degrades cutin, the cuticular polymer of higher plants [4], Unlike the oflier lipolytic enzymes, such lipases and esterases, cutinase does not require interfacial activation for substrate binding and activity. Cutinases have been largely exploited for esterification and transesterification in chemical synthesis [5] and have also been applied in laundry or dishwashing detergent [6]. 

The knowledge of physico-chemical parameters like surface tension, conductivity, turbidity and the pH of the washing liquor is important for the improvement of existing washing and dishwashing detergent formulations further development of new alternatives. Today s advanced physico-chemical and analytical methods make... 

---