Patent GB-839773-A (GB)
Title: Improvements in polyester resins from dicarboxylic acid anhydrides and monoepoxides
IPC: C08G63/58
Filed: 1957-04-05
Abstract: Thermoplastic polyesters having at least three linear polyester branch chains joined to a nucleus forming initiator (and in which the number of branch chains is equal to the functionality of said initiator and the length of each branch chain is theoretically equal to the total number of mols. of the monoepoxide (i) plus the number of mols. of the dicarboxylic anhydride, (iii) per mol. of the initiator (ii), divided by the functionality of the initiator) are prepared by reacting, without the formation of water and at temperatures at which carboxy-epoxy, phenolic hydroxyl-epoxy and alcoholic hydroxyl-anhydride reactions occur but below carboxylhydroxyl reaction temperatures, (i) a monoepoxide, (ii) an initiator having a functionality of at least three, and (iii) one or more dicarboxylic acid anhydrides; the mono-epoxide (i) being oxirane or an alkyl oxirane, or an ether or an ester containing only one three-membered epoxide substituent, and also being free of other groups capable of reacting with an acid anhydride; the initiator (ii) being a monomeric phenol or a monomeric or a polymeric ether, or an ester, or a polycarboxylic acid or a polyhydric alcohol, and also having at least three substituents of carboxylic, alcoholic hydroxyl, or phenolic hydroxyl radicals; wherein either the anhydride or the monoepoxide but not both, can be ethylenically unsaturated, the mol. ratio of (i) to (iii) being from 2:1 to 1:2 and the mol. ratio of (i) plus (iii) to (ii) being greater than 7:1.  In general the process is carried out at temperatures of 120-150 DEG  C. and a tertiary amine catalyst may be employed.  The following compounds are specified: (i) ethylene-, propylene- and butene - 2 - oxides; phenyl-, isopropyl-, butyl- and allyl-glycidyl ethers; glycidyl-benzoate, -acrylate, -methacrylate, -crotonate and -acetate; (ii) pyromellitic, tricarballylic and aconitic acids; phloroglucinol and 1,2,4-trihydroxy-benzene; glycerol, erythritol, pentaerythritol, di- and poly-pentaerythritol, and sorbitol; castor oil; polyhydric alcohols which are the reaction product of 1 or 2 mols. of phthalic acid or anhydride with 2 or 3 mols. of pentaerythritol respectively; bis-phenol terminated bisphenol-epihalohydrin condensates which may or may not be partially esterified with a dicarboxylic acid or anhydride, and the bis-phenol-halohydrin condensate of Example (7) below; and a wide range of addition polymers, e.g. polyvinyl alcohol, the copolymers of vinyl toluene with hydroxypropyl-acrylate (see Example (12)) or acrylic acid, and of vinyl acetate with crotonic acid; (iii) succinic, adipic, maleic, glutaric, phthalic, sebacic, naphthalene dicarboxylic, endo-cis-bicyclo-(2,2,1)-5-heptene-2,3-dicarboxylic, and 1,4,5,6,7,7-hexachloro-bicyclo - (2,2,1) - 5 - heptene - 2,3 - dicarboxylic anhydrides.  All three reagents may be reacted together or the initiator may be reacted first with one of the other reagents, the other being added later.  In examples: (1)-(6), (8), (10) and (11) maleic and phthalic anhydrides and propylene oxide are reacted with glycerine, pentaerythritol, dipentaerythritol, pyromellitic acid, phloroglucinol or castor oil.  (7) A polyhydroxy polyether is prepared from 5 mols. bisphenol A, 4 mols. epichlorhydrin, 2 mols. ethylene chlorhydrin and 6.9 mols. NaOH.  The product which contains 6 hydroxyl groups is reacted with propylene oxide, and maleic and phthalic anhydrides.  (9) as (7) but using butyl glycidyl ether in place of propylene oxide.  In (1)-(8) and (11) the resultant polyesters, being unsaturated, are copolymerized with styrene which is inhibited with tert.-butyl catechol, in the presence of a paste of benzoyl peroxide and tricresyl phosphate. In (12) vinyl toluene, propylene oxide and acrylic acid are dissolved in xylene and methyl isobutyl ketone and are co-polymerized in the presence of benzoyl peroxide and a solution of benzyl trimethyl ammonium hydroxide in methanol.  The resultant polymer, which is a co-polymer of vinyl toluene and hydroxy propyl acrylate, is reacted with propylene oxide and phthalic anhydride in (12)-(15); xylene, methyl isobutyl ketone and "Cellosolve" (Registered Trade Mark) acetate are used as solvents.  In (W)-(Z) polyesters of earlier examples are mixed with butylated urea-formaldehyde resins, butyl alcohol, xylene, toluene and "Cellosolve" (Registered Trade Mark) acetate being used as solvents; the use of alkylated urea- or melamine-aldehyde resins in a similar way is discussed but not exemplified.  Uses.-The resins may be used for potting, casting, moulding, laminating and coating (e.g. cables or wires) and in textile or adhesive applications.