Antistatic agents combinations

None of the antistatic agents combine all the properties needed, i.e., antistatic efficiency, heat stability, miscibility with the basic polymer, nontoxicity, hygienic acceptability. The easiest practical answer to this problem is to use mixed antistatic agents showing a synergetic effect. It concerns either the mere mixtures of two or more antistatic agents or the so-called internal mixtures, which means that the same molecule contains many effective atoms. 

Film or sheet generally function as supports for other materials, as barriers or covers such as packaging, as insulation, or as materials of constmction. The uses depend on the unique combination of properties of the specific resins or plastic materials chosen. When multilayer films or sheets are made, the product properties can be varied to meet almost any need. Further modification of properties can be achieved by use of such additives or modifiers as plasticizers (qv), antistatic agents (qv), fire retardants, sHp agents, uv and thermal stabilizers, dyes (qv) or pigments (qv), and biodegradable activators. 

Typical commercial ethoxylated sorbitan fatty acid esters are yellow Hquids, except tristearates and the 4- and 5-mol ethylene oxide adducts which are light tan soHds. These adducts, as well as the 20-mol adducts of the triesters, are insoluble but dispersible in water. The monoester 20-mol adducts are water soluble. Ethoxylated sorbitan esters are widely used as emulsifiers, antistatic agents, softeners, fiber lubricants, and solubilizers. In combination with the unethoxylated sorbitan esters or with mono- or diglycetides, these are often used as co-emulsrfiers. The ethoxylated sorbitan esters are produced by beating sorbitan esters with ethylene oxide at 130—170°C in the presence of alkaline catalysts. 

Most polymers are very good electrical insulating materials because of their chemical composition, i.e., their electrical conductivity is exceptionally low. Because of this important property, many plastics are used to produce electrically nonconductive parts. However, the high surface resistance leads to an unwanted property the material is prone to electrostatic charge accumulation. To facilitate dissipation of the charge, antistatic agents are incorporated, which combine with atmospheric moisture on the plastic surface to form a conductive film. 

The combination of a positive charge and reducibility of tetrazolium salts finds use as anticorrosion agents for metals.634,635 The y are components of an oxidant/etchant bath composition for silicon dioxide corrosion-resistant surfaces.636 They are also used as antistatic agents in polyamide... 

Impermanent antistatic agents that are not surface-active include triethanolamine, glycerol in combination with potassium acetate, as well as inorganic salts such as lithium chloride [471]. 

Polyurethanes can be used in applications where electrical properties are important. They are not normally used for high-voltage insulation. Polyurethanes are often used directly or in combination with epoxies for encapsulation. The addition of antistatic agents to polyurethane gives a product with the correct electrical properties while retaining the excellent wear needed for a number of roller-type applications. 

By adding an antistatic agent (complex non-ionic or cationic materials), the surface resistivity is reduced, along with a reduction in static charge accumulation. The agent functions by the formation of an antistatic layer on the surface, which by attraction of moisture and in combination with the antistatic agent itself, conducts away charges. 

Antistatic agents for carpet backing gives a complete antistatic carpet in combination with conductive pile material can be used in adhesives for secondary backing also, compatible with binders for needle felts. 

Material preparation The plastic/metal/mixtru e may be cleaned, dried, colored, blended, heated, cooled, or in some way readied for use in the machine. This can be one resin, thermoplastic or thermoset, or combination of base resin and additives. Additives include colors, metal particles, foaming agents, antistatic agents, fillers, fibers, flow aids, stabilizers, antioxidants, mold-release agents, binders, flame retardants, etc. 

Alkanolamine derivatives, such as the triethanolamine laurate ester, find use as antistatic agents in polymer compositions. Polyoxyalkylated amines, the ethanolamine derivatives of fatty acids, and long-chain alkyl derivatives of diethanolamine also have been used as antistatic agents in polymers. Textile carpets and fibers are rendered antistatic and soil resistant by treatment with combinations of diethanolamine and palmitic or stearic acid. 

It is possible that an antistatic agent will prove technically effective, but interfere unacceptably with other additives in the polymer, such as stabilizers. On the other hand, some additives can successfully combine an antistatic role with one or more other important functions. 

The addition of water-insoluble aliphatic alcohols or ethylene-oxide condensation products to polyethylene were in US. Patent 2,525,691, issued on October 10, 1950, to ICI scientists. Examples of alcohols used as antistatic agents were a saturated aliphatic alcohol(s) such as myristic, cetyl and stearyl alcohol in combination with an xmsaturated alcohol such as oleyl alcohol. The second type of anti-static agent was obtained from the interaction of ethylene oxide with a mixture of a saturated and an unsaturated alcohol. 

Yang et al. [245] have used TG for the study of the thermal weight loss of low-MW surfactants, used as antistatic agents in HDPE containers. In a typical example of product development Ward et al. [246] have reported the use of TG in combination with static decay and optical measurements for evaluation of the effectiveness of some 13 internal antistatics. With fail/pass criteria of a weight loss of 5% (up to 250°C) and a static decay time of less than 0.5 s at 70% r.h., none of the commercially available surfactants did meet all critical criteria developmental PMMA antistats were reported. 

Examples of simple antistatic agent mixtures are alkanolamines mixed with fatty acids, alcohols, or amides and eventually with metallic oxides or hydroxides. An example of a combination antistatic agent is the N-methyl-iV-stearyl-... 

It imparts processing and good long-term stability to TPO. It is particularly suitable for use in PP films. It can be used alone or in combination with other additives such as costabilizers (thioesters, phosphites), light stabilizers, and antistatic agents. 

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