Patent GB-912944-A (GB)
Title: Diols and polyesters thereof
IPC: C08G63/682
Filed: 1959-06-02
Abstract: Polyesters, which are useful for making thermosetting, flame-resistant resins, are prepared by reacting an ethylenic dicarboxylic acid or anhydride, such as maleic anhydride, with a halogenated phenoxy-methyl diol of the formula <FORM:0912944/IV(a)/1> the two hydroxyl groups being attached to different carbon atoms (or an epoxide thereof), or <FORM:0912944/IV(a)/2> wherein X is chlorine or bromine, and R is an aliphatic hydrocarbon group having 2 to 10 carbon atoms, or a plurality of such groups separated by ether linkages.  Hard resins are obtained by reacting the polyesters with liquid ethylenic monomers such as styrene, chlorostyrene, diallyl phthalate, vinyl acetate, and acrylonitrile.  In Example 1, a mixture of 1-pentachlorophenoxy-2,3-propanediol, propylene glycol, maleic anhydride and toluene, containing a trace of hydroquinone (as gelation inhibitor) is heated under reflux with removal of reaction-water until an acid value of 57,5 is attained.  The polyester is then interpolymerized with styrene using benzoyl peroxide as catalyst.  Figures are given for the strength, hardness and flame-resistance of the cured resin.  In Example 2, the polyester is made with fumaric acid instead of maleic anhydride.  A mixture of maleic anhydride and adipic acid (see Example 6), or of maleic anhydride and phthalic anhydride (see Example 7), may also be used to make the polyester.  In Example 9, diethylene glycol is used in place of the propylene glycol of Example 1.  Example 4 describes the preparation of a polyester and a resin starting from a mixture of 1-pentabromophenoxy-2,3-propanediol, propylene glycol and maleic anhydride.  Example 10 describes the preparation of a polyester by reacting the compound of the formula <FORM:0912944/IV(a)/3> with maleic anhydride; the polyester is then reacted with styrene to obtain a resin.  The resins may be used to impregnate glass fibre fabrics or mats.  For the preparation of the halogenated phenoxy diols-see Group IV(b).  Specification 768,957 also is referred to.ALSO:Halogenated phenoxymethyl diols having the formula <FORM:0912944/IV (b)/1> wherein X is chlorine or bromine, R is an aliphatic hydrocarbon group having 2 to 10 carbon atoms, or a plurality of such groups separated by ether linkages, and the two hydroxyl groups are attached to different carbon atoms, are made by reacting a pentachloro- or pentabromo-phenol with an epihalohydrin and hydrolysing the glycidyl ether so obtained, or by reacting a pentachloro- or pentabromo-benzene with a compound having the formula HO-CH2-R(OH)2.  In Example A, pentachlorophenol is reacted with epichlorohydrin, in the presence of caustic soda, to give pentachlorophenyl glycidyl ether, which is then hydrolysed with dilute sulphuric acid to yield 1-pentachlorophenoxy-2,3-propane diol. Example 4 describes the preparation of 1-pentabromophenoxy-2,3-propane diol by the same process.  In Example 10, pentachlorophenyl glycidyl ether is heated with excess ethylene glycol, in the presence of stannic chloride, to obtain 1-pentachlorophenoxy-2-hydroxy-3-beta-hydroxyethoxy-propane.  But if 1 mole of ethylene glycol is reacted with at least 2 moles of the glycidyl ether, the product is <FORM:0912944/IV (b)/2> When equal molar amounts of pentachlorophenyl glycidyl ether and 1-pentachlorophenoxy-2,3-propanediol are reacted together, the product is <FORM:0912944/IV (b)/3> The pentachlorophenyl glycidyl ether may be replaced by the pentabromo compound to give mixed compounds in which one pentahalophenyl group is brominated, while the other is chlorinated.  In Example 5, hexachlorobenzene is heated with trimethylol ethane in the presence of NaOH and trimethylbenzyl ammonium chloride (catalyst), the reaction being carried out in the dimethyl ether of diethylene glycol as solvent.  The product is worked up to isolate 2-pentachlorophenoxymethyl-2-methyl-1,3-propanediol.  The diols may be reacted with dicarboxylic acids and anhydrides to obtain polyesters which may be used to make flame-resistant resins (Group IV(a)).  Specification 768,957 also is referred to.