STS
Characteristics:
Molar mass: 194.2g/mol, white powder.
(a) purity > 90%, Fe < 30 ppm
(b) purity > 70%, sodium sulfate < 30% and Fe < 100ppm.
General Uses:
This salt of p-toluenesulfonic acid (PTSA) finds its widest application in the manufacture of an assortment of liquid powdered detergents. For both purposes, the basis of its use is not any effect it has on the detergency power, or as a foam builder, but rather in its two main functions as a hydrotropic and anti-caking agent in the following manners, in the actual manufacturing process:
a) As a hydrotrope in powdered detergent: It changes the solubility of anionic and nonionic surfactants including the main detergent powder component, the alkyl- benzenesulfonates, in water, and decreases the viscosity of the detergent paste initially formed during the manufacturing of detergent powders. It is thus possible to increase the initial concentration of the various low soluble ingredients at a constant viscosity, thus decreasing the amount of water entering the spray dryer and therefore greatly decreasing the energy consumption during the drying phase. In other words, this increased concentration of the formulation ingredients in the spray-dryer feed does effectively result in a significant increase of the actual plant production capacity at constant energy consumption, without affecting significant changes to the plant hardware.
b) As an anti-caking agent in powdered detergent production: It prevents the caking of the powder particles once they leave the spray dryer. Usually, this caking results in the clogging of the conveyer system, of the packaging equipment, requiring the time-consuming interruption of the operation, for a manual de-clogging process. This" stickiness " of the powder particles, also often causes dismay to the consumer, when part of the powder sticks to the base and the walls of the package and therefore fails to pour out of the package freely.
c) As a rinsing aid: The increased solubility of the detergent ingredients in water will probably result in a significant decrease in water requirement during the machine, or hand-rinsing and in a considerable overall saving of water consumption. Use is made of this property in dishwashing formulations.
d) As a formulation modifier: It acts as an agent enabling the substitutions of the less expensive and environmentally more suitable carbonate instead of polyphosphate-based builders for powder detergent.
e) As a homogenizing agent in liquid detergent formulations: The increased solubility of other anionic, as well as, various nonionic detergent components in diverse liquid detergent formulations. In this capacity, it prevents phase separation, as well as/or, cloudiness of the finished product, especially during cold storage.