Procédé de fabrication de dimères et trimères d'acrylates

摘要

The invention relates to polymerizable mixtures comprising a dimeric and/or trimeric C1-C18-alkyl acrylate optionally in association with other comonomers such as methyl methacrylate and/or styrene, processes for polymerizing such mixtures and the polymer so prepared. (For the preparation of the dimeric and trimeric acrylates see Division C2.) The copolymers, which may typically contain 40% by weight of methyl methacrylate, 40% by weight of styrene and 20% by weight of the trimeric acrylate, are effective as coatings that are resistant to cracking and have high impact strength.ALSO:Preparation of dimeric and/or trimeric acrylates from an acrylate monomer of the formula CH2=CH.COOR in the presence of a catalyst of the formula or wherein R is an alkyl group containing from 1 to 18 carbon atoms; R1 and R4 are the same or different phenyl, alkyl group containing from 1 to 18 carbon atoms or alkyl substituted phenyl in which the alkyl substituent(s) contain(s) a total of from 1 to 8 carbon atoms; and R2 and R3 are (a) the same or different alkyl groups containing from 1 to 18 carbon atoms optionally containing one or more inert substituents or (b) when taken together with the nitrogen to which they are attached form a saturated cyclic amine group containing up to 5 carbon atoms, and optionally an oxygen or sulphur atom in the ring which may contain one or more alkyl substituents having a total of up to 6 carbon atoms. The reaction is carried out at a temperature in the range 0 DEG to 100 DEG C. optionally in the presence of an inert volatile organic solvent, e.g. hexane, benzene or toluene. The specified catalysts include N,N,N1,N1 - tetraethyl - or N,N,N1,N1 - tetramethyl - P - phenylphosphonous diamide and N,N-diethyl- or N,N-di-n-butyl-P,P-di-phenylphosphinous amide, and may be prepared as solutions by treating a suitably substituted dichlorosphosphine or chlorophosphine with an appropriate amine in one of the above-mentioned solvents and removing the amine salt which forms. Specified monomeric reactants include methyl, ethyl, iso-propyl-butyl, 2-ethylhexyl, t-dodecyl and octadecyl acrylates. Diethyl-2-methyleneglutarate and diethyl-2-methylene-4-carbethoxy pimelate are prepared from ethyl acrylate. Hydroquinone monomethyl ether may be present as inhibitor during the reaction.