Patent GB-746063-A (GB)
Title: Flame retardant resinous compositions and copolymers
IPC: C08G63/682
Filed: 1953-09-07
Abstract: A composition polymerizable to an infusible, insoluble resin comprises an unsaturated polyester and a cross linking agent at least one of which components comprises a chemically combined adduct of a hexahalocyclopentadiene and a dienophile, said resin preferably having a halogen content of 14 to 45 per cent.  The polyester may contain the adduct in the acid and/or alcohol part of the molecule and unsaturation may be introduced by preparing a mixed ester of said adduct and a compound retaining copolymerizable unsaturation after esterification.  Alternatively or in addition the adduct may be a di-olefinic or an acetyleni compound or the hexahalocyclopentadiene may be combined with an excess of dienophile.  The dienophile may be an unsaturated polycarboxylic acid, anhydride, acid halide or ester or an unsaturated polyhydric alcohol or an ether and ester thereof and specified are maleic, fumaric, citraconic, chloromaleic, mesaconic, pyrocinchonic, acetylene dicarboxylic, aconitic and itaconic acids and derivatives; butene and pentene diols, allyl and vinyl glycerol and pentaerythritol ethers and acrylic and methacrylic esters of glycerol and pentaerythritol.  Unsaturation may be introduced into the polyester chains by the dienophile acids, esters, alcohols and ethers.  Polyhydric alcohols, chain stoppers and esterification catalysts used in the preparation of the polyester are also specified.  Cross-linking agents listed are styrene, monoand dichlorostyrenes, divinyl benzene, diallyl phthalate, maleate and benzene phosphonate, vinyl acetate and benzoate, allyl diglycol carbonate, triallyl cyanurate, methyl methacrylate, reaction products of hexachlorocyclopentadiene with isoprene or butadiene and compounds of the type diallyl-1,4,5,6,7,7-hexachlorobicyclo - (2.2.1) - 5 - heptene - 2,3 - dicarboxylate.  Optional ingredients are catalysts such as benzoyl, acetyl, lauroyl and methyl ethyl ketone peroxides and cumene hydroperoxide; promoters such as cobalt resinate, maleate and napththenate, dibutyl amines and dodecyl mercaptan; inhibitors such as hydroquinone, benzoquinone, p-t-butyl catechol, p-phenylene diamine, trinitrobenzene and picric acid; inert and/or fibrous fillers such as calcium carbonate, chopped fibre glass rovings, macerated fabric, asbestos fibres and mica; dyes; pigments; plasticizers; lubricants and other copolymerizable polyesters. Foamed articles may be produced by the use of sodium bicarbonate and laminates may be obtained from cured glass fibre cloth or mats.  The resins are flame resistant and may be used in castings for electrical contacts, wall coverings, panels, pipes and ash trays.ALSO:A hexahalocyclopentadiene is chemically combined with a dienophile to give a 1-4 adduct.  The halogen of the hexahalocyclopentadiene may be chlorine, bromine, fluorine and the dienophile may be an unsaturated polycarboxylic acid, anhydride, acid halide, or an unsaturated polyhydric alcohol or an ether or ester thereof (particularly allyl esters) and may contain further unsaturation such as in diolefinic and polyolefinic or acetylenic compounds.  Other dienophiles specified are isoprene and butadiene.  Listed dienophiles are maleic, fumaric, citraconic, chloromaleic, mesaconic, pyrocinchonic, acetylene dicarboxylic, aconitic, itaconic and endomethylene tetrahydrophthalic acids, anhydrides, acid chlorides and esters (e.g. fumaryl chloride and dimethyl maleate), butene- and pentene-diols, allyl and vinyl glycerol ethers, allyl and vinyl pentaerythritol ethers and unsaturated acid esters of glycerol and pentaerythritol (e.g. acrylic and methacrylic acid esters).  The reaction is exemplified by the equations <FORM:0746063/IV(a)/1> (1,4,5,6,7,7 - hexachlorobicyclo - (2.2.1) - 5-heptene-2, 3-dicarboxylic anhydride) and <FORM:0746063/IV(a)/2> Among other adducts specified are 2-(1,4,5,6,7,7-hexachlorobicyclo - (2.2.1) - 5 - heptene - 2 - yl)-methoxy - 1,2 - propanediol; 1,4,5,6,7,7 - hexachlorobicyclo - (2.2.1) - 5- heptene - 2 - acetic-2-carboxylic anhydride and various esters such as diallyl - 1,4,5,6,7,7 - hexachlorobicyclo-(2.2.1) - 5 - heptene - 2.3 - dicarboxylate.  The adducts may be copolymerized with other unsaturated compounds to give flame-resistant products (see Group IV (a)).