Additives for Polymers April 1994

High molecular weight antioxidant for polyurethanes

RT Vanderbilt has introduced a patented, low volatility, liquid high molecular weight antioxidant system for flexible PU slabstock. Vanox 927 consists of a diphenylamine in combination with a hindered phenolic. Contact: RT Vanderbilt Co, 30 Winteld Street, Norwalk, CT 06855, USA.

Colourable conductive compounds

A new compound which provides permanent static dissipation without using carbon black has been developed by Cabot Plastics to meet the demand for colourable conductive compounds. The new Cabelec 3371 compound has been designed to meet the CECC 00015 specification for safe handling areas and performs in low humidity. Its intrinsic alloying system ensures long-term dissipation of static electricity. Because it is a dissipative compound, Cabelec 3371 provides products with a higher resistivity than conventional conductive materials and is, therefore, especially valuable in applications where slower discharge of static electricity is required. The compound can be processed on most types of injection moulding machinery at cylinder/nozzle temperatures in the range 160-170°C and mould temperatures from 30- 50°C. Contact: Cabot Plastics, Interleuvenlaan 5, B-3001, Leuven, Belgium. Tel: +32-l 639- 0111. Fax: i-32-1640-1253.

Conductive compounds for EMI shielding

A range of conductive compounds which reduce electro-magnetic interference in electronic equipment is being marketed by Cabot Plastics. The materials have been designed, to provide EM1 shielding within complex injection-moulded shapes cost- effectively. Offered as an alternative to secondary treatments such as conductive

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paints, the new compounds solve the problems created when microprocessor- controlled devices transmit frequency signals to the surrounding environment. The metal- filled compounds both reduce emissions and protect equipment from incoming signals. The range consists of eight compounds and includes black and white ABS-based products, a natural PP-based product and a black ABS/PC-based product. Flame-retardant versions are also available. All the compounds can be processed on conventional moulding equipment. Data sheets with detailed information about the physical properties of the compounds are available from Cabot Plastics. Contact: Cabot Plastics, Interleuvenlaan 5, B-3001, Leuven, Belgium. Tel: +32-l 639- 0111. Fax: -132-1640-1253.

Cyclic acetal blowing agent

Toho Chemical Industry in Japan is developing a cyclic acetal blowing agent which it believes will be totally ozone friendly. The acetal is said to provide the same performance as cyclopentane agents currently being adopted in Europe, while at the same time being safer and easier to handle (1,3-dioxolane has an ignition temperature of 4O”C, higher than cyclopentane; it can also be used in the form of a premix, line conventional CFC blowing agent). Contact: Toho Chemical Industry, Tokyo, Japan.

Blowing agent for PVC wire and cable

Henley Chemicals Division of Boehringer Ingelheim has developed an exothermic blowing agent specifically for use in flexible PVC wire and cable covering. EX310, a self- nucleating azodiacarbonamide, has a decomposition temperature of 310-350°F. Upon decomposition, this yellow blowing agent becomes white. The gas given off is mostly nitrogen, with trace amounts of carbon dioxide and ammonia.

O1994 Elsevier Science Ltd