| 摘要 |
Polymerization inhibitors, especially hydroquinone, the monomethyl ether of hydroquinone, t-butylcatechol or p-hydroxy phenylamine, are removed from ethylenically unsaturated monomers, styrene, a-methylstyrene, ethyl styrene, vinyl toluene, divinylbenzene, trivinylbenzene or vinyl napthalene, by a process which comprises contacting the inhibitor containing monomer with the salt form of an anion exchange resin having a macroreticular structure and a specific surface area of at least one square metre per gramme when measured by the BET method using nitrogen adsorption at - 195 DEG C. The anion exchange resin may be in the sulphate, nitrate, carbonate, bicarbonate or phosphate form, the preferred form being the chloride. It is advantageous to have the anion exchange resin in the anhydrous state, thus if the monomer contains water not only will the inhibitor be removed but the monomer will simultaneously be dehydrated. The resin may be used in the form of a bed contained within a column, and the resin may be of the quaternary ammonium or tertiary amine type. The Specification refers to a large number of commercially used polymerization inhibitors which are most of the amine or phenol type, and in examples describes the efficiency resulting from the use of a resin having a macroreticular structure compared with the standard so-called porous resin, using ethyl acrylate, methyl methacrylate and styrene monomers.ALSO:Polymerization inhibitors, especially hydroquinone, the monomethyl ether of hydroquinone, t-butylcatechol or p-hydroxy phenylamine, are removed from ethylenically unsaturated monomers, alkyl or aryl acrylates, methacrylates or ethylacrylates, styrene, a-methylstyrene, ethyl styrene, vinyl toluene, vinyl chloride, vinylidene chloride, vinyl stearate, divinylbenzene, trivinylbenzene or vinyl naphthalene, by a process which comprises contacting the inhibitor containing monomer with the salt form of an anion exchange resin having a macroreticular structure and a specific surface area of at least one square metre per gram when measured by the B.E.T. method using nitrogen adsorption at -195 DEG C. The anion exchange resin may be in the sulphate, nitrate, carbonate, bicarbonate or phosphate form, the preferred form being the chloride. It is advantageous to have the anion exchange resin in the anhydrous state, thus if the monomer contains water not only will the inhibitor be removed but the monomer will simultaneously be dehydrated. The resin may be used in the form of a bed contained within a column, and the resin may be of the quaternary ammonium or tertiary amine type. The Specification refers to a large number of commercially used polymerization inhibitors which are mostly of the amine or phenol type, and in examples describes the efficiency resulting from the use of a resin having a macroreticular structure compared with the standard so-called porous resin, using ethyl acrylate, methyl methacrylate and styrene monomers. |
