Additives for Polymers September 1991

Talc products agency in

EM4/RFI shielding

Supacel blowing agents

Antioxidant approved for foodstuffs

Literature on ceramic fibres

Toxic properties of polymers and additives

The talc products of Talc de Luzenac are now marketed in the UK by Luzenac UK, Gorsey Lane, Widnes, Lanes, WAS ORP. Telephone: +44-51-4203116. These products were previously marketed by Durham Chemicals.

INCO, of West Bromwich, says it can now provide EMI/RFI shielding on components made from materials such as carbon loaded plastics, epoxy composites, PA, and LCPs, by sputter coating. The metal can be deposited at thicknesses from 0.1 to 5.0 microns, on surfaces with which electroless plating cannot be used. The company says the metal is deposited pure, providing a high density shield without embrittlement of the substrate. A typical coating is a single layer of nickel, but for more robust coatings, the company recommends a base layer of stainless steel, a second coat of copper, and a final layer of stainless steel.

Colourfast Plastics of Eccles (UK) is to market all its masterbatch blowing agents under the trade name SUPACEL. These blowing agents are produced in such a way that imposes minimal heat history on the material to affect either storage life or processing quality.

An antioxidant from GE Specialty Chemicals, Ultranox 626, has been approved by the BGA, the German state health authority. The product comprises bis(2,4_butylphenyl) pentaerythritol diphosphite, to which no more than 1.00/o of trisopanolamine has been added. It has been approved for use at different levels in various types of PE, 1% in PVC, 0.1% in PP, and 0.25% in PET and PC. GE says there is a need to improve the colour and process stability of HiVIWHDPE film and bottles, which Ultranox will achieve, together with reduced gels.

Ceramic fibres used in thermoset composites are explained in new literature from Carborundum Co.‘s Fibers Div., Niagara Falls, NY, (USA). Fiberfrax fibres reportedly can be used as a reinforcement or filler in phenolic, epoxy, nylon, melamine and polyurethane systems. They are said to provide better retention of properties at elevated temperatures in appliance and under- the-hood automotive applications.

BOOKS/PUBLICATIONS

This publication from BAPRA Technology in the UK is by V. 0. Sheftel, and is in the form of a directory which gives a comprehensive guide to the toxicity of over 1000 polymers, monomers and additives used by the rubber and plastics industries.

14 01991 Elsevier Science Publishers Ltd.