Patent GB-856917-A (GB)
Title: Improvements in or relating to synthetic polyesters and products formed therefrom
IPC: C08G63/20
Filed: 1958-06-20
Abstract: A film- or fibre-forming polyester having improved dye-affinity has a minor proportion of its structural units in the form of organic radicals containing carboxylate, phosphonate or sulphinate groups in the form of free acids or as metal salts, with the proviso that if said groups are only carboxylate groups, some at least of said structural units occur away from the end of the polymer chain.  The major proportion of the structural units are preferably derived by reaction between a diester of a dicarboxylic acid and an aliphatic diol or diester of an aromatic diol or by polymerization of an alkyl ester of a monohydroxymonocarboxylic acid.  Specified polyesters to be modified are polyethylene terephthalate, polytetramethylene terephthalate, polyethylene hexahydroterephthalate, polyethylene bibenzoate, poly (trans-1, 4-trans hexahydroxylyl) terephthalate, polyhexamethylene adipate, polyethylene sebacate and the polyesterification products of ethyl 4-(b -hydroxyethoxyl)-3-methylbenzoate or methyl p-(2-hydroxyethoxy) benzoate.  The metal carboxylate groups may be introduced by including with the polyester forming components a compound of formula:  <FORM:0856917/IV(a)/1> where n is a small integer, M is an atomic equivalent of a metal, -R- is an organic radical, -Z- and -Z1- are -O- or <FORM:0856917/IV(a)/2> , and -Y and -Y1 are -lower alkyl, -H or <FORM:0856917/IV(a)/3> lower alkyl; with the proviso that when -Z- or -Z1- is <FORM:0856917/IV(a)/4> , its attached terminal member -Y or -Y1 is lower alkyl, whereas when -Z -or -Z1- is -O-, its attached terminal member -Y or -Y1 is other than lower alkyl; and with the further proviso that when -Z- or -Z1- is -O- and is attached to a carbon atom of an aromatic ring, its attached terminal member -Y or -Y1 is <FORM:0856917/IV(a)/5> -lower alkyl.  The metal carboxylate compound may be sodium dimethyl trimesate, lithium desoxycholate, dipotassium diphenyl-2, 4,2 1,41-tetracarboxylate or sodium monomethyl-4-hydroxyazelate.  The free carboxyl groups may be p introduced by heating a melt of a linear polyester in which the end groups are predominantly hydroxyl with a dianhydride, e.g. pyromellitic, naphthalene-1, 4, 5, 8-tetracarboxylic, diphenyl-3, 4, 31, 41-tetracarboxylic, butane-1, 2, 3, 4-tetracarboxylic or 2, 2-bis (3, 4-dicarboxyphenyl) propane dianhydride.  The phosphonate groups may be introduced into the polyester by including with the polyester forming components a compound of formula:  <FORM:0856917/IV(a)/6> where -Q1 is -OH, -OM or R111-(-Y1)r, Y and Y1 are -OH, <FORM:0856917/IV(a)/7> (lower alkyl) or <FORM:0856917/IV(a)/8> (lower alkyl), -M is one atomic equivalent of a metal, -R11- and -R111- are aliphatic, alicyclic or aromatic non-hetero polyvalent radicals, q is 1 or 2, r is 0 or 1; and the sum of q and r is 1 or 2; with the proviso that when r is zero, -Q is -R111-H and with the further proviso that whenever either of -Y- and -Y1- is joined to -R11- and -R111- by -O-, the carbon of -R11- and -R111- to which such attachment is made is saturated.  The phosphonate may be a salt (preferably an alkali or alkaline earth salt) of 3, 5-dicarbomethoxybenzenephosphonic, 4-carbomethoxybenzenephosphonic, hydroxymethylphosphonic, 3-carboethoxypropanephosphonic 10-carboethoxydecane-phosphonic, bis-(hydroxymethyl)-phosphonic, 4-carbomethoxyphenyl-4-tolylphosphonic or phenyl carboethoxymethylphosphonic acid.  The sulphinite groups may be introduced into the polyester by including with the polyester forming components a compound of formula:  <FORM:0856917/IV(a)/9> where -M is an atomic equivalent of a metal, -R- is an organic radical, - Y is-OH, <FORM:0856917/IV(a)/100> (lower alkyl) or <FORM:0856917/IV(a)/111> (lower alkyl), with the proviso that when -Y is -OH it is attached to a saturated carbon atom, and -Y1 is -H or the same as -Y.  The sulphinate may be a salt (preferably an alkali or alkaline earth salt) of 3, 4-dicarbomethoxybenzenesulphinic, m-carboethoxybenzenesulphinic, pcarbomethoxybenzenesulphinic, 2(b -carbomethoxyethyl)-benzene sulphinic, 5-acetoxynaphthalene-1-sulphinic or 6-acetoxynaphthalene-2-sulphinic acid.  Polyesters containing free carboxyl, phosphonic or sulphinic groups may be made by treating polyesters containing the corresponding metal salts with hot dilute sulphuric acid. Polyesterification may be effected in the presence of a catalyst (e.g. a titanate ester, a salt of calcium, manganese or lanthanum or antimony oxide), a colour inhibitor (e.g. phosphoric acid or a salt or ester thereof), a pigment or a delusterant (e.g. titanium dioxide or barium carbonate).  In examples polyesters were made by reacting (1)-(2) dimethyl terephthalate, ethylene glycol and either potassium dimethyl trimesate or potassium desoxycholate i.e. (HO)2C23H37 COOK; (3) dimethyl terephthalate, butanediol-1:4 and potassium diethyl trimesate; (4) dimethyl hexahydroterephthalate, ethylene glycol and potassium diethyl trimesate; (5) Methyl p-(2-hydroxyethoxy)-benzoate and potassium diethyl trimesate; (6) - (7) Polyethylene terephthalate flake or powder and pyromellitic dianhydride or any other of the previously specified dianhydrides; (8) - (11) dimethyl terephthalate, ethylene glycol and potassium bis-(hydroxymethyl) phosphonate, disodium 4 - carbomethoxybenzenephosphonate, sodium hydrogen 3, 5-dicarbomethoxybenzenephosphonate or disodium 3, 5-dicarbomethoxybenzenephosphonate; (12) dimethyl terephthalate ethylene glycol and sodium 3, 5-dicarbomethoxybenzenesulphinate.ALSO:Salts of carboxylic, phosphonic or sulphinic acids for use as modifying agents for film- or fibre-forming polyesters (see Group IV(a)) are made in examples as follows: (1) Potassium dimethyl trimesate is made by refluxing trimethyl trimesate with potassium hydroxide in the presence of methanol; the sodium salt is similarly prepared and the lead salt is made by treating the potassium salt with lead acetate; (8) Potassium bis-(hydroxymethyl) phosphonate is made by neutralising bis-(hydroxymethyl) phosphonic acid with an equivalent amount of potassium hydroxide; (9) disodium 4 - carbomethoxybenzenephosphonate, 4 - CH3OOCC6H4 P(O) (ONa)2 is made by titrating a solution of 4-carbomethoxy-benzenephosphonic acid in ethanol with sodium hydroxide; (10) Sodium hydrogen 3, 5-dicarbomethoxy-benzenephosphonate, 3, 5-(CH3OOC)2 C6H3P(O) (OONa) OH is made by mixing dimethyl 5-aminoisophthalate with hydrochloric acid and sodium fluoborate, adding sodium nitrate solution, washing and drying the resulting pasty mess, adding dioxane to it, then adding cuprous chloride and phosphorus trichloride and next adding water and evaporating the solvents.  The product is dissolved in water, the solution adjusted to pH7 with sodium carbonate, ethanol added, the resulting precipitate filtered and dried, dissolved in warm hydrochloric acid and the solution filtered and cooled to yield 3, 5-dicarbomethoxybenzenephosphonic acid.  This is dissolved in methanol and sodium methoxide added to form the desired product; (12) Sodium 3, 5-dicarbomethoxybenzenesulphinate <FORM:0856917/IV(b)/1> is made by heating sodium 3, 5-dicarbomethoxybenzenesulphonate with phosphorus oxychloride to produce 5-chlorosulpho-isophthalyl chloride.  This is then added to a solution of sodium bisulphite and sodium hydroxide which is thereafter acidified with sulphuric acid and the product extracted with ether to form 3, 5-dicarboxybenzenesulphinic acid which is then esterified with methanol and the resulting ester treated with sodium carbonate to form the desired product.