Patent GB-690921-A (GB)
Title: Improvements in or relating to the preparation of polyesters of 3,5,5-trimethyl hexanol
IPC: C08K5/10
Filed: 1948-10-21
Abstract: Polyesters of 3,5,5-trimethyl-1-hexanol with inorganic polybasic acids or aromatic polycarboxylic acids (see Group IV (b)) are stated to be excellent plasticizers for rubbers and synthetic resins, especially for vinyl resins such as polyvinyl chloride.  Specified inorganic acids are boric acid, phosphoric acid, and carbonic acid, and specified aromatic acids are phthalic, isophthalic, terephthalic, hemimellitic, trimellitic, trimesic, mellophanic, pyromellitic, benzene pentacarboxylic acid and naphthalic acid.  Other vinyl resins specified are polyvinyl bromide and copolymers of vinyl chloride or bromide with one or more other polymerizable unsaturated compounds containing a single olefinic bond, e.g. vinyl acetate, vinylidene chloride or bromide, styrene, acrylonitrile, methyl (or ethyl) acrylate, methyl chloroacrylate, ethyl cyanoacrylate, methyl methacrylate, diethyl fumarate, diethyl chloromaleate, isobutyl crotonate, vinyl isobutyl ether, vinyl methyl ketone, vinyl benzoate, vinyl butyrate, vinyl furane, vinyl pyridine, dichlorostyrene, isobutylene and ethylene.  Examples are given to show the improved properties of materials plasticized with the esters.  Thus polyvinyl chloride stocks are prepared by mixing polyvinyl chloride with the diphthalate ester to form a dough-like mix which is then milled at 240 DEG  F. to form a clear homogenous sheet.  The latter is removed from the mill, allowed to cool to room temperature and then moulded at 320 DEG  F., the moulded samples being shown to have superior properties to polyvinyl chloride compositions containing the same proportion of di-2-ethylhexyl phthalate as plasticizer.  An example is also given to illustrate the improved electrical resistivity of polyvinyl chloride plasticized with the esters, the resistivity of a stock prepared from polyvinyl chloride, basic lead carbonate, clay and carbon black and containing di-(3,5,5-trimethylhexyl) phthalate as plasticizer, being shown to be superior to that of a stock prepared same amount of di-2-ethyl hexyl phthalate as plasticizer. Similar results are also obtained when the carbon black is omitted from the composition.  The Specification as open to inspection under Sect. 91 also includes the production of polyesters of the alcohol with aliphatic polycarboxylic acids such as oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, brassylic, thapsic, maleic, fumaric and glutaconic acids, alpha-butyl-alpha-ethyl-glutaric acid, alpha-beta-diethyl succinic acid; 1,1,5-pentane-tricarboxylic acid, 1,2,4-hexane tricarboxylic acid and 1,2,4-butane tricarboxylic acid, and it is stated that these esters also are valuable plasticizers for rubbery and resinous materials.  This subject-matter does not appear in the Specification as accepted.  Reference has been directed by the Comptroller to Specifications 632,758, 632,759 and 632,760.ALSO:Polyesters of 3,5,5-trimethyl-1-hexanol are obtained by reacting the alcohol with an inorganic polybasic acid or an organic aromatic polycarboxylic acid or a corresponding acid anhydride or acid halide or by reacting a halide ester of the alcohol with a sodium salt of the inorganic polybasic acid or organic aromatic polycarboxylic acid.  Specified inorganic acids are boric acid, phosphoric acid and carbonic acid and specified aromatic acids are phthalic, isophthalic, terephthalic, hemimellitic, trimellitic, trimesic, mellophanic, pyromellitic, benzene pentacarboxylic acid and naphthalic acid.  It is preferred to use a molar excess of the hexanol and preferably a ratio of 3 mols. of the hexanol for each carboxyl group of the acid is used.  The reaction is conducted by adding the anhydride, acid or acid halide to the alcohol, which has been cooled to a low temperature, preferably below 15 DEG  C.  The mixture is then brought to the reaction temperature which varies according to the ester being prepared but is generally from 20 DEG  C. or lower to 300 DEG  C. or higher.  The monoester which is formed as the reaction proceeds should be separated from the reaction mixture or converted to a less harmful form.  Separation may be effected by high temperature, high vacuum distillation or in the case of the phosphate ester by adding sufficient base to neutralize 1/3 of the free carboxyl groups present in the monoester, after which the product is distilled to recover the pure triester.  A preferred method consists in adding a finely divided ion-exchange resin to remove the monoester and then washing with an organic solvent to remove the resin-monoester combination. In examples: (1) and (2), the phthalate ester is prepared from the alcohol and phthalic anhydride; (3) and (4) the triphosphate is obtained from phosphorus oxychloride and the alcohol, the ester being purified in (3) by treating the residue, after distilling off excess alcohol, with an aqueous solution of sodium hydroxide to neutralize 1/3 of the free carboxyl groups present in the monoester and then distilling at reduced pressure, and in (4) by treating with an ion exchange resin as above.  The ester products are stated to be excellent plasticizers for rubbers and synthetic resins (see Group IV (a)), and may be used as dielectrics in applications when a liquid insulating compound is required.  They are also useful as repellants for insects and for other applications in the insecticidal, fungicidal and pesticidal fields.  U.S.A. Specification 2,410,118 is referred to.  3,5,5-Trimethyl hexanol can be obtained by the saponification and hydrogenation of the acetate of 2 - (2,2 - dimethylpropyl) - buten - 1 - ol-4, the preparation of which is described in Specification 657,497.  The Specification as open to inspection under Sect. 91 also includes the production of polyesters of 3,5,5-trimethyl hexanol with aliphatic polycarboxylic acids such as oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, brassilic, thapsic, maleic, fumaric, glutaconic, a -butyl-a -ethyl glutaric acid, a -beta-diethyl succinic acid, 1,1,5-pentanetricarboxylic acid, 1,2,4-hexanetricarboxylic acid and 1,2,4-butane tricarboxylic acid.  This subject-matter does not appear in the Specification as accepted.  Reference has been directed by the Comptroller to Specifications 632,758, 632,759 and 632,760, [all in Group IV (a)].