1380093 Polyepoxide-polysiloxanes CIBAGEIGY AG 24 Oct 1972 [25 Oct 1971] 49019/72 Headings C3T and C3B Polyepoxide-polysiloxanes having the unit formula in which Z denotes a n-valent radical of a polycarboxylic acid or of an acid polyester, Q denotes an aliphatic, cycloaliphatic, heterocyclic or aromatic epoxide containing group in which the two oxygen atoms bonded to Q are attached to adjacent carbon atoms, R 1 and R 2 denote an alkyl, alkenyl, aralkyl, aryl, cycloalkyl, alkoxy or aryloxy group or an epoxide-containing polysiloxane chain, m is greater than 1, preferably 2-30, and n is 2 or 3, are prepared by esterifying or trans-esterifying at a temperature of 50- 200‹ C. a stoichiometric mixture of a polysiloxane of the formula in which R denotes a hydrogen atom or a C 1-4 alkyl group, and an adduct, prepared from a polyepoxide and a polycarboxylic acid or an acid polyester, of the formula preferably in the presence of a catalyst such as quaternary ammonium salts, titanium salts of organic acid, aluminium halides or boron halides. Preferably Q represents the 3-(3SP1/SP,4SP1/SP- epoxy - cyclohexyl) - 2,4 - dioxaspiro - (5,5)- undecylene-(8,9)-radical. Preferred polysiloxanes used for forming the adduct are 1,4-diethoxyoctamethyltetrasiloxane; 1,3-dimethyl- 1,2,3 - triphenyl - 1,2,3 - trimethoxytrisiloxane; and 1,6 - dimethoxyhexamethylhexaphenylhexasiloxane. Numerous examples of polyepoxides suitable for the formation of the adduct are listed and belong to the following groups:- cycloaliphatic epoxides with at least 1 five- or six-membered ring to which a 1,2-epoxide group is bonded; cycloaliphatic epoxides in which the epoxide groups are in alkyl side chains particularly glycidyl groups; polyglycidyl compounds containing a nitrogen-containing heterocyclic ring; di- or poly-glycidyl ethers of polyhydric alcohols; polyglycidyl esters of polybasic carboxylic acids or of polyesters with terminal carboxyl groups; and N-glycidyl derivatives of aromatic amines. Preferred polyesters for forming the adduct are esters of dicarboxylic acids, especially straight-chain aliphatic dicarboxylic acids, and aliphatic diols, the polyesters preferably possessing at least 8 carbon atoms in the recurring units and having a melting point of 50-140‹ C. Curable mixtures suitable for mouldings can be prepared from the polyepoxide-polysiloxanes, epoxide resin curing agents and optionally a curing accelerator, and other polyepoxide compounds and customary modifiers such as extenders, fillers, reinforcing agents, pigments, dyestuffs, organic solvents, flow control agents, plasticizers, thixotropic agents, flameproofing substances and mould release agents; examples of each ingredient being listed. In the examples polyepoxide-polysiloxanes are prepared by reacting an adduct prepared by reacting an acid polyester of sebacic acid and hexanediol or neopentyl glycol with 3-(3SP1/SP,4SP1/SP- epoxycyclohexyl) - 8,9 - epoxy - 2,4 - dioxaspiro - (5,5)-undecane, with a methoxy-containing methylphenylpolysiloxane using tetramethyl ammonium chloride as catalyst. The resulting resins are each cured in an aluminium mould using hexahydrophthalic anhydride as curing agent in the presence of a solution of sodium in 2,4-dioxy-3-methylolpentane. Uses.-Paints, lacquers, compression moulding compositions, sintering powders, dipping resins, casting resins, injection moulding formulations, impregnating resins and binders, adhesives, tool resins, laminating resins, sealing and filling compositions, floor covering compositions, and binders for mineral aggregates.
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