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Antistatic Plastic Shovels Disclosure Number: IPCOM000029505D
Publication Date: 2004-Jul-01

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The Prior Art Database


Plastic tool blades, for example polyolefin shovel blades, are effectively made antistatic by incorporation therein of a polyetheresteramide additive. The shovels are suitable for example for use with powders, granules, dusts, and the like, in municipal, industrial or household settings. The polyolefin is for example polypropylene or polyethylene, for example high density polyethylene (HDPE). The polyetheresteramide additive is incorporated in the molded plastic articles by known methods, for example by mixing the additive with the plastic in appliances such as calendars, mixers, kneaders, extruders, and the like. The additives may be added to the plastic alone or with further optional components. The additives may be added by dry blending, compaction, wet mixing in the form of a solution, dispersion or suspension in a solvent, water or oil, as a masterbatch or in the melt. For example, the additives are incorporated in the plastic during processing. Processing includes extrusion, co-kneading, pultrusion, compression molding, sheet extrusion, thermoforming or injection molding. The polyetheresteramides are present at a level from about 2% to about 30% by weight, from about 5% to about 15% by weight, from about 0.5% to about 15% by weight, for example from about 1% to about 10% by weight, for instance from about 2% to about 8% by weight, or from about 4% to about 10%, based on the weight of the polymer. The polyetheresteramide additives are for example those as described in GB 2112795 and GB 2112789 and in U.S. Pat. Nos. 3,839,245, 4,230,838, 4,332,920 and 5,965,206 and in U.S. Pat. Nos. 5,096,995, 5,604,284, 5,652,326 and 5,886,098. The polyetheresteramides comprise polyamide and polyether segments linked together with ester groups. They are prepared for example from polyamines, polybasic carboxylic acids and polyoxyalkylene glycols. In the simplest sense, they are a copolymer of a polyamide with carboxylic end groups (a dicarboxylic polyamide) and a polyoxyalkylene glycol, for example the product of PA 12 and polyethylene glycol. Aromatic polyetheresteramides are described similarly, and additionally comprise an aromatic portion. Aromatic polyetherester amides are those where an aromatic portion is introduced as part of the polyether (polyol) segment, for example through a bisphenol such as bisphenol A. Polyetheresteramides are commercially available under tradenames such as PEBAX or PELESTAT. The polyetheresteramides may be employed together with a polyamide (nylon) component and with a salt component. Suitable salt components are disclosed for example in U.S. Pat. Nos. 5,965,206 and 6,552,131. The polyetheresteramides may be employed together with other known antistatic agents.