Additives anionic antistats

Antistatic agents are incorporated in plastics to prevent or reduce the build-up of static charges on the surface of a product. They must be able to stand the processing temperatures used and not interact negatively with other additives (some cationic and anionic antistats interfere with PVC heat stabilisers). They must also satisfy food contact regulations, and not adversely affect performance in other ways. 

Anionic antistatic additives have active ingredients such as alkyl sulfonates, sulfates or phosphates, dithiocarbamates, or carboxylates. Sodium alkyl sulfonates produce an antistatic effect in PVC as well as in styrenic polymers. 

Anionic Antistats Anionic antistats for PVC include sodium salts of alkyl sulfonates and phosphates. These additives are, in addition, external lubricants. In some cases, their inclusion may boost stabdizer activity (as with lubricants in general). Generally, their use poses less of a hazard to heat stabUity than amine salts of strong acids. At more than trace levels, adjustments to the overall stabilizer and lubricant package are usually needed. Usage with barium or lead must also be checked, as noted above, for unexpected effects. 

Antistatic polystyrenes have been developed in terms of additives or coatings to minimise primarily dust collecting problems in storage (see Antistatic agents). Large Hsts of commercial antistatic additives have been pubhshed (41). For styrene-based polymers, alkyl and/or aryl amines, amides, quaternary ammonium compounds, anionics, etc, are all used. 

Surface-active agents iacrease the conductivity of oils quite significantly (97), and addition of water, probably dissolved at the iaterface with the surfactant, further iacreases the conductivity. Nonionic and cationic surface-active agents are preferred to anionic surface-active agents probably because of their higher solubiHty ia oils and higher hygroscopicity. Many anionic surfactants have adequate antistatic efficiency, but they are used less frequendy. 

Generally, PS containing amine groups are synthesized by condensation of chlorinated PS with amines. These type of resins are widely used as anionic resins.[8] PSs containing imidazol rings have antistatic properties and are used as additives to make dyeing of synthetic fiber materials easy [9] (Scheme [3]). 

Antistatic agents, anionic, to be used as additives to other finishing agents. 

Monoalkyl phosphate and phosphate esters are special types of phosphoms-contain-ing anionic surfactants that are of great industrial importance. They are used for flameproofing, as antistatic for textiles, for foam inhibition, as an extreme pressure (EP) lubricant additive, as a surfactant component for alkaline, and as acid cleaners and for special cosmetic preparations (5). The commercially available phosphate ester products are complex mixtures of monoester and diester, free phosphoric acid, and free nonionic. 

Antistatic additives or agents operate by being present at the surface of the plastic where they attract a layer of moisture which acts as a conductor for electrostatic charges. They are normally incorporated at a level of 0.01-0.2% and are usually surfactants, i.e. cationic, anionic and non-ionic compounds. 

Static charges on polymer surfaces can be controlled by the presence of antistatic agents that make the surface more conductive or less resistive. For example, water within a hydrophilic polymer can act as an antistatic agent and prevent static buildup. The amount of water is important for example, water in a polyamide in equilibrium with air at 65% RH acts as an antistatic agent, but at iow RH values, water is not effective. Since most polymers used in packaging are not hydrophilic, antistatic additives may be used to control static. Generally, these agents are cationic, anionic, or nonionic surfactants. 

Properties Liq. si. sol. in water sp.gr. 1.13 acid no. 430 flash pt. (TCC) 265 F anionic NFPA Health 3, Flammability 1 Uses Acid catalyst in resin curing chemical intermediate in formulation of rust preventatives antistat textile lubricant oil additive heavy metal extractant surfactant Manuf./Distrib. Rhodia/Phosphorus Perf. Derivs. http //www.rhodia-ppd.com Trade Name Synonyms Findet DD t[Finetex http //www.finetexmc.com, Servoxyl VPIZ... 

Uses Emulsifier mfg. of textile lubricants solvent and waterless hand cleaners coemulsifier detergent additive in petrol, oils intermediate for anionic surfactants surfactant in cosmetics plastics antistat Trade Name Synonyms Ethylan ME t[Akzo Nobel Surf. Chem. AB... 

CAS 39407-03-9 EINECS/ELINCS 201-116-6 Synonyms Phosphoric acid, octyl ester Empirical C8H19O4P Properties M.w. 210.21 anionic Uses Detergent in dry cleaning emulsifier in emulsion polymerization, pesticides, cosmetics acid catalyst in resin curing chem. intermediate in formulation of rust preventatives, antistats, textile lubricants, oil additives, heavy metal extractants Manuf./Distrib. Rhodia/Phosphorus Perf. Deri vs. 

Properties Anionic Toxicoiogy TSCA listed Uses Antistat, surfactant for cosmetics detergent, sebum control additive for shampoos... 

Migratory antistats (MAS). Migratory antistats have chemical structures that are composed of hydrophilic and hydrophobic components. These materials have limited compatibility with the host plastic and migrate or bloom to the surface of the molded product. The hydrophobic portion provides compatibility within the polymer and the hydrophilic portion functions to bind water molecules onto the surface of the molded part. If the surface of the part is wiped, the MAS is temporarily removed, reducing the antistat characteristics at the surface. Additional material then migrates to the surface until the additive is depleted. These surface-active antistatic additives can be cationic, anionic, and nonionic compounds. 

Blooming antistatic additives fall into fom categories (i) non-ioitic, (ii) anionic, (iii) cationic, and (iv) amphoteric. 

Antistatic additives can be classified by application method, as internal and external, and by chemistry, as anionic, cationic, and non-ionic. Internal agents are normally compounded at 0.1-3.0% by weight and have a slight compatibility with the polymer, but the molecule has a hydrophilic head forcing it to migrate to the surface and attract moisture from the environment, which increases the surface conductivity. These are easy to use and have low addition rates, often also providing other benefits such as improved processability and mould release. 

Antistatic additives are divided into non-ionic, anionic, cationic, and amphoteric. Non-ionic antistatic additives are the most commonly used. These include fatty acid esters, ethoxylated alkylamines, diethanolamides, and ethoxylated alcohol. 

Uses Emulsifier, lubricant for hair rinses hand modifier for textiles spreading agent in paste waxes and polishes antistat and emulsifier for SR and polyolefins Properties Off-wh. waxy flake sp.gr. 0.94 m.p. 41-43 C Alrowet D-65 [Ciba Spec. Chems./Plastic Addit.j Chem. Descrip. Dioctyl sodium sulfosuccinate ionic Nature Anionic... 

There are also some additives used in formulating sizes. Fatty substances, e.g., ->fatty acid esters, in combination with nonionic or anionic emulsifiers (->surfactants), and - sulfonated oils plasticize the size film, impart antistatic properties, help in foam control and improve smoothness. Fatty alcohol ethoxylates are sometimes added to increase wettability of the yam. 

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