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Process for a Uniform Size Spherical Phenol Formaldehyde Ion Exchange Resin

IP.com Disclosure Number: IPCOM000231853D
Publication Date: 2013-Oct-09
Document File: 5 page(s) / 68K

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The IP.com Prior Art Database

Abstract

One class of ion exchange resins is produced from the condensation polymerization of phenol and formaldehyde. The current resins are made by bulk polymerization and mechanically ground to make irregular non spherical granules. Uniform spherical polymers have advantages in lower pressure drop, better chromatographic separation, and better mixed bed separability. Spherical polymers may be more resistant to attrition than irregular particles. Uniform particle size polymers also have better yields in the desired particle size range lowering the manufacturing cost. In this technology, vibrational jetting into a gas phase is used to form uniform spherical phenol formaldehyde drops in the 5 to 2000 micron range. The reaction rate is accelerated by jetting into and acid or base catalyst mist and by using microwave radiation so that the beads quickly polymerize beyond the gel point to preserve the bead sphericity and uniformity. The solid partially converted polymer may be transferred to another vessel for curing. This technology could also be used for producing uniform spherical condensate polymers other than phenol formaldehyde resins in the 5 to 2000 micron range.

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Process for a Uniform Size Spherical Phenol Formaldehyde Ion Exchange Resin 

October 7, 2013

Abstract

One class of ion exchange resins is produced from the condensation polymerization of phenol and formaldehyde. The current resins are made by bulk polymerization and mechanically ground to make irregular non spherical granules. Uniform spherical polymers have advantages in lower pressure drop, better chromatographic separation, and better mixed bed separability. Spherical polymers may be more resistant to attrition than irregular particles. Uniform particle size polymers also have better yields in the desired particle size range lowering the manufacturing cost. In this technology, vibrational jetting into a gas phase is used to form uniform spherical phenol formaldehyde drops in the 5 to 2000 micron range. The reaction rate is accelerated by jetting into and acid or base catalyst mist and by using microwave radiation so that the beads quickly polymerize beyond the gel point to preserve the bead sphericity and uniformity. The solid partially converted polymer may be transferred to another vessel for curing. This technology could also be used for producing uniform spherical condensate polymers other than phenol formaldehyde resins in the 5 to 2000 micron range.

Primary Article

Condensation polymers of phenol and formaldehyde are some of the earliest commercial resins [[1]] and are used in many industrial applications. One application is as ion exchangers.  The phenolic groups on the resin itself are capable of ion exchange [[2]].  Strong acid cation exchange resins can be made by adding sodium sulfite to the phenol and formaldehyde to introduce a methylene sulfonic acid group [[3]]. Strong acid cation exchange resins can also be synthesized by reacting sulfonated phenol with formaldehyde. Anion exchange resins can be made by adding triethylene tetramine to the phenol and formaldehyde [[4]]. These final anion exchange resins such as Duolite™ A7 typically have high capacity. Phenolic resins with other functional groups can be synthesized. Currently, commercially available phenolic ion exchange resins are produced by bulk polymerization then mechanically ground to smaller particle sizes. This produces non-spherical particles with irregular shapes. The irregular shapes are jagged and prone to attrition. The particle size distribution is typically broad requiring sifting. This sifting generates yield loss and increased cost.

Many ion exchange resins are produced by functionalization of styrene-divinylbenzene copolymers. These copolymers are produced by free radical suspension polymerization. The suspension of drops is formed by the drop breakup of a monomer phase into an aqueous phase caused by the inertial forces from a mechanical impeller and results in a Gaussian particle size distribution of spherical copolymer.  Upon sulfonation to a cation exchanger or chloromethylation and amination to an anion exchanger the final resin remains spherical...