GB500223A - Improvements in or relating to the impregnation of porous materials - Google Patents

Abstract

500,223. Polymerization products. DU PONT DE NEMOURS & CO., E. I. Aug. 5, 1937, No. 21660. Convention date, Aug. 22, 1936. [Class 2 (iii)] Rigid porous materials, e.g. wood, cement, marble, tile, fibre board, cork, are impregnated to a depth appreciably below the surface thereof with one or more substantially - completely monomeric polymerizable acrylic compounds and with a polymerization catalyst in the same phase, and the impregnant is polymerized. The material may be immersed, after evacuation of its pores, in a solution of the catalyst in the monomer, with or without the use of raised pressure, or in an atmosphere of monomer and catalyst both in vapour phase, and polymerization brought about. There are specified: catalysts-organic peroxides such as acetyl and .benzoyl peroxides, sulphur dioxide, hydrogen peroxide, perborates, percarbonates, oxygen, ozone; monomers-esters, amides, acids, nitriles, and salts of the acrylic series, particularly esters, amides, nitriles, and salts of alpha-alkyl acrylic acids, o.g. methyl, ethyl, propyl, and higher acrylates, methyl, ethyl; n- and iso-propyl, isobutyl, and higher methacrylates, acrylic nitrile, acrylamide, methacrylonitrile, methacrylamide, sodium and lead methacrylates. For treating wood, there may be added dyes, e.g. Oil Red O, Sudan Brown 3G, Anthraquinone Violet R Base, or alpha-p-toluidoanthraquinone; the process may be applied to veneers, e.g. using methyl methacrylate, to plywoods (which maybe further laminated), to shingles, and to chair rungs. In examples: black walnut shot-gun fore-ends, apple saw-handles, maple textile-bobbin blanks, and white pine, oak and maple blocks were impregnated with liquid methyl methacrylate and benzoyl peroxide under raised pressure; white pine and maple blocks were placed in vacuo, then impregnated with methyl methacrylate vapour and sulphur dioxide ; white pine and maple blocks were half immersed in liquid methyl methacrylate containing dissolved sulphur dioxide, impregnation taking place by capillary action; the methacrylate being afterwards polymerized by heat in each case. Specications 418,449 and 436,084 are referred to. According to the Specification as open to inspection under Sect. 91, the rigid porous materials are impregnated with one or more monomeric polymerizable organic compounds, with or without a catalyst, which is subsequently polymerized in situ. There are additionally specified: monomers-vinyl esters, olefines, styrene ; dyes-Oil Yellow F. This subject-matter does not appear in the Specification as accepted.