GB870696A - Epoxy acetals - Google Patents

Abstract

The invention comprises an epoxidized cycloaliphatic acetal containing at least two epoxide groups derived from an acetal obtainable by reaction between an aldehyde of the general formula: <FORM:0870696/IV (a)/1> wherein R1, R2, R3, R4, R5, R6, R7, R8 and R9 represent halogen atoms, alkoxy groups, or aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon radicals, or hydrogen atoms, or R1 and R5 taken together represent an alkylene group, and a compound containing at least two alcoholic hydroxyl groups, including polymeric compounds with free hydroxyl groups, such as polyvinyl alcohol and partially hydrolysed polyvinyl acetate. The novel epoxides may be made by epoxidizing the corresponding unsaturated acetals using organic per acids, or by treatment with HOCl followed by a dehydrochlorinating agent. The epoxides can be hardened with suitable hardening agents such as aliphatic and aromatic primary, secondary and tertiary amines (including tetrahydroxyethyldiethylenetriamine, triethanolamine, tris-dimethylaminophenol (Example 17) are triethylenetetramine (Example 18)) guanidines, dicyandiamide, aniline-, urea-, or melamine-formaldehyde resins, poly(aminostyrenes), polyamides, e.g. from aliphatic polyamines and dimerized or trimerized unsaturated fatty acids, isocyanates, isothiocyanates, polyhydric phenols, quinone, phenol-aldehyde resins, products of aluminium alcoholates and tautomerically reacting compounds, Friedel-Crafts catalysts and their complexes, and phosphoric acid. Preferred hardeners are polybasic carboxylic acids and their anhydrides (especially phthalic anhydride in many examples). Accelerators such as tertiary amines and polyhydroxyl compounds (including 2, 4-dihydroxy-3-methoxypentane in Examples 16 and 17) may be present. It is advantageous to employ impure polyepoxides containing a proportion of acetals in which the epoxide groups have been wholly or partially saponified to hydroxyl groups. Fillers, plasticizers, colouring substances, asphalt, bitumen, glass fibres, mica, powdered quartz, cellulose, kaoline, finely divided silica or metal powders may be added. In Example (13) a polyepoxide of the invention is mixed with a liquid polyglycidyl ether of bisphenol A. In Example (14) another polyepoxide of the invention is mixed with a compound of the formula: <FORM:0870696/IV (a)/2> In Example (17) a polyepoxide of the invention and a polyepoxide of the above formula are separately mixed with methyl-endomethylene tetrahydrophthalic anhydride, which may be replaced by a mixture of hexahydro-, tetrahydro-, and phthalic anhydrides.ALSO:The invention comprises an epoxidized cycloaliphatic acetal containing at least two epoxide groups derived from an acetal obtainable by reaction between an aldehyde of the general formula: <FORM:0870696/IV (b)/1> wherein R1, R2, R3, R4, R5, R6 R7, R8 and R9 when taken individually represent halogen atoms, alkoxy groups or aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon radicals, or hydrogen atoms, or R1 and R5 taken together represent an alkylene group, and a compound containing at least two alcoholic hydroxyl groups, one of the epoxide groups being in each cyclohexane ring derived from the aldehyde. Preferred diepoxides have the general formula: <FORM:0870696/IV (b)/2> wherein the R and R1 radicals are hydrogen or halogen atoms, hydrocarbon radicals or R1 and R5, or R11 and R51, together represent an alkylene group. Other preferred diepoxides have the formula: p <FORM:0870696/IV (b)/3> wherein A represents a tetravelent aliphatic radical which contains at least 4 carbon atoms none of which is attached to more than one of the oxygen atoms, and which may be substituted by hydroxyl, ether, sulphide, carboxyl, ester, keto, aldehyde or acetal groups, and other symbols are as above. Similar triepoxides are formed from hexavalent alcohols. The novel epoxides are obtained by epoxidizing the corresponding unsaturated acetals using organic per-acids, or by treatment with HOCl followed by a dehydrochlorinating agent. The acetals used as starting materials may be made by reacting or an epoxide that will form the appropriate dialcohol, polyalcohol or an epoxide that will form the acetal by fission of the epoxide ring. The novel epoxides may be hardened with conventional hardeners (see Group IV(a)).