| abstract |
This specification discloses that certain polychlorinated or polybrominated aromatic hydrocarbon compounds can be incorporated in thermosetting polymer compositions to make the thermosetting compositions flame retardant without injuring the desirable physical and electrical properties of the thermosetting compositions when in the thermoset state. These polyhalogenated aromatic hydrocarbons are apparently caused to react into the thermosetting composition, provided there is a minimum of 1 mol of a polyunsaturated monomer containing carbon to carbon unsaturation for each 3 mols of polychlorinated aromatic hydrocarbons. The thermosetting compositions generally contain a polyunsaturated monomer, a polyunsaturated polymer with carbon to carbon double bond unsaturation or a polyphenylene ether polymer which may be used in place of some or all of the polyunsaturated polymer, and a polyhalogenated aromatic hydrocarbon, containing at least 50% by weight combined chlorine or bromine and whose molecular weight is greater than 200. These thermosetting compositions can be heat cured or thermoset by a free radical initiator at a temperature of at least 130 DEG C, and can contain pigments, reinforcing fibers, release agents, coupling agents, and other incidental amounts of additives commonly used in thermosetting resin compositions. |