| 摘要 |
Polystyrene particles are covered with a high power loss factor mixture of water and a wetting or coating agent in a weight ratio of particles to mixture between 25 : 1 and 1 : 1 and then exposed to a high frequency field until the particles soften and expand, the cellular product being removed before it chars. The particles may be pre-expanded, in which case they contain 3%-30% of a volatile aliphatic hydrocarbon of a B. Pt 35 DEG -60 DEG C. Flame retardency can be obtained by using a paste containing antimony oxide and a chlorinated aliphatic hydrocarbon. An apparatus is described; and a list of wetting and coating agents is given.ALSO:Polymeric particles of low power loss factor are covered with a high power loss factor mixture of water and a wetting or coating agent in a weight ratio of particles to mixture between 25 : 1 and 1 : 1. and then exposed to a high frequency field until the particles soften and expand, the cellular product being removed before it chars. The particles may be pre-expanded, in which case they contain 3-30% of a volatile aliphatic hydrocarbon of a boiling point 35 DEG -60 DEG C. Flame retardant products can be obtained by using a coating of water, antimony oxide and a chlorinated aliphatic hydrocarbon. An apparatus is described, and a list of wetting and coating agents given.
|
