Acrylate

Acrylic acid esters are esters derived from acrylic acid ( CH2 = CH- COOH) and thus have the general formula CH2 = CH- COOR. Here, R stands for a Organylgruppe.

Be produced a large scale, the esters by reacting the acrylic acid with the corresponding alcohol with the addition of a catalyst. Reaction with lower alcohols (methanol, ethanol) is at 100-120 ° C under acidic heterogeneous catalysis ( cation exchanger) instead. The reaction of higher alcohols (n- butanol, 2 -ethylhexanol ) in the homogeneous phase is catalyzed with sulfuric acid. Acrylic acid esters of higher alcohols by transesterification of lower esters catalyzed by titanium alkoxides or organic tin compounds (eg, dibutyltin dilaurate) accessible. Since it is an equilibrium reaction in the esterification, the reaction products are removed by distillation to increase the sales. Because of the pronounced tendency to polymerize the acrylic acid ester, the reaction mixtures with inhibitors are added (such as phenothiazine ) and the esterification lean air atmosphere (oxygen content of less than 20 vol - % ) is performed. In large quantities, inter alia, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate and acrylic acid 2-ethylhexyl ester is [(2 -ethylhexyl ) acrylate, 2 -EHA ] produced.

Acrylic acid esters are often used in the Diels -Alder reaction as dienophiles for preparing cyclic carboxylic acid esters. The main application of acrylic acid esters is in homo- and copolymers with, for example, acrylic acid, acrylamides, methacrylates, acrylonitrile, maleates, vinyl acetate, vinyl chloride, styrene, butadiene and unsaturated polyesters for adhesives and sealants, paints and coatings, coatings for textiles, leather, paper, and for a variety of plastics. As reactive diacrylate, isobornyl acrylate and 2 -EHA are mainly used.