Patent GB-842759-A (GB)
Title: New polycarbonates and a process for the production thereof
IPC: C08G64/18
Filed: 1957-11-14
Abstract: New polycarbonates, suitable for the manufacture of stretchable filaments or films, have more than 40 recurrent units fo the general formula:-  [-O-CH2-CH2-O-R-O-CH2-CH2-O-CO-] in which R is an arylene radical.  The polycarbonates may be made (a) by heating at 50 DEG -350 DEG C. an aromatic bis-b - hydroxyethyl ether with an aromatic, aliphatic or cycloaliphatic diester of carbonic acid and a monohydroxy compound, preferably in an inert gas and, if desired, in the presence of a transesterification catalyst (e.g. an alkali or alkaline earth metal or an alcoholate or hydride thereof; sodium phenate; sodium, lead or antimony oxide; or a titanium or molybdenum compound): preferably the latter part of the reaction is effected under vacuum and at the end of the reaction basic catalysts are neutralised with a volatile acidic material (e.g. dimethyl sulphate); (b) by heating a bis aryl-, alkyl- or cycolalkyl-carbonate of a bis-b -hydroxyethyl ether either alone in the presence of a basic catalyst or with a free bis-b -hydroxyethyl ether and/or other dihydroxy compound; (c) by reacting 1 mol of the aromatic bis-b -hydroxyethyl ether with 1 mol of phenol chlorocarbonic ester and polycondensing the resulting monocarbonate by heating to 250 DEG C. with removal of phenol.  Specified bis-b -hydroxyethyl ethers are those of 4, 41-dihydroxydiphenyl, 1, 5-dihydroxynaphthalene, hydroquinone, 2, 3, 5, 6,-tetrachlorohydroquinone-1, 4 and tetrachloro-4, 41-dihydroxy-diphenyl-2, 2-propane.  The bis-b -hydroxyethyl ether may be used in admixture with other dihydroxy compounds e.g. hydroquinone, resorcinol, pyrocatechol, 4, 41-dihydroxydiphenyl, 1, 4-dihydroxynaphthalene, o-, m- or p-hydroxybenzyl alcohol, ethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, quinitol or m- or p-xylylene glycol.  Examples describe the manufacture of polycarbonate from (1)-(6) and (9) Diphenyl carbonate and (1) the bis-b -hydroxyethyl ether of 1, 5-dihydroxynaphthalene; diphenyl-4, 41- bis (b -hydroxyethyl ether); (3) 2, 3, 5, 6-tetrachlorophenylene-1, 4-bis-(b -hydroxyethyl ether); (4) a mixture of diphenyl-4, 41-bis-(b -hydroxyethyl ether) and 1, 5-naphthalene-bis-(b -hydroxyethyl ether); (5) a mixture of diphenyl-4, 41-bis-(b -hydroxyethyl ether) and hydroquin-one bis-(b -hydroxyethyl ether); (6) a mixture of diphenyl-4, 41-bis-(b -hydroxyethyl ether) and hexanediol-1, 6; (9) the bis-b -hydroxyethyl ether of tetrachloro-4, 41-dihydroxy-diphenyl-2, 2-propane.  Further examples describe the manufacture of polycarbonates from (7) the bis-phenyl carbonic acid ester of 1, 5-naphthylene-bis-(b -hydroxyethyl ether) and 1, 5-naphthalene-bis-(b -hydroxyethyl ether); (8) the monocarbonate formed by reacting 1, 5-naphthalene-bis-(b -hydroxyethyl ether) with phenol-chlorocarbonic acid ester.  Some of the polycarbonates are soluble in methylene chloride, tetrachloroethane chloroform, benzene or toluene. Specification 772,627 is referred to.ALSO:Bis-aryl, alkyl or cycloalkyl carbonates of aromatic bis-b -hydroxyethyl ethers may be made, for example, (a) By reacting 1 mol. of a bis-chlorocarbonic ester of the dihydroxy compound with a sodium alcoholate or phenate or (b) by reacting the dihydroxy compound with a phenol chlorocarbonic acid ester in pyridine or in the melt.  Also, mono-carbonate of aromatic bis-b -hydroxethyl ethers may be made by heating 1 mol. of the dihydroxy compound with 1 mol. of phenol chlorocarbonic acid ester at 140 DEG C., hydrogen chloride being split off.  The dihydroxy compound may be the bis-b -hydroxyethyl ether of 4.41-dihydroxydiphenyl, 1.5-dihydroxynaphthalene, hydroquinone, 2.3.5.6.-tetrachlorohydroquinone or tetrachloro -4.41-dihydroxydiphenyl -2.2-propane.  The monomeric carbonates are converted into polycarbonate resins (see Group IV(a)).