Process for production of amphoteric electrolyte resin by continuous bulk polymerization and apparatus for the production
A process for producing an amphoteric electrolyte resin by continuous bulk polymerization at low cost is provided. Also provided is an apparatus for achieving the process. The process comprises the steps of: feeding, from the mixture supply side, a mixture comprising 0.01 to 10 wt % of at least one radically polymerizable basic monomer containing a nitrogen atom, 0.01 to 35 wt % of at least one radically polymerizable acidic monomer having a carboxyl group and 45 to 99.98 wt % of a monomer capable of copolymerizing with these monomers.
1. A process for producing an amphoteric electrolyte resin by continuous polymerization, comprising the steps of:
feeding, from a mixture supply port, a monomer mixture containing 0.01 to 10% by weight of at least one radically polymerizable basic monomer(s) including a nitrogen atom, 0.01 to 35% by weight of at least one radically polymerizable acidic monomer(s) having a carboxyl group and 45 to 99.98% by weight of a monomer(s) capable of copolymerizing with these monomers, or a mixture of the monomer mixture and a polymerization initiator and/or an organic solvent having a boiling point of 80° C. or higher and contained in an amount of 10% by weight or less to the total weight of the monomers, into a reaction zone composed of four polymerization zones independently providing the mixture temperatures of T 1 , T 2 , T 3 and T 4 which satisfy the following expressions:
T 1 =50 to 160° C., T 2 =70 to 190° C., T 3 =70 to 250° C., T 4 =70 to 270° C., and T 1 <T 2 , T 2 <T 3 and T 3 <T 4 ; and
continuously passing the mixture through the reaction zone with stirring while the residence time in each of the polymerization zones is controlled to 5 to 20 minutes; whereby
a copolymer is produced in a reaction yield of 85% or higher in one passage through the reaction zone, and an amphoteric electrolyte resin having a number average molecular weight of 700 to 6,000 and a Mw/Mn ratio of 1.5 to 10 can be obtained.
2. The process for producing an amphoteric electrolyte resin according to claim 1 , wherein the mixture contains the polymerization initiator; and T 1 , T 2 , T 3 and T 4 respectively satisfy the following expressions: T 1 =50 to 100° C., T 2 =70 to 120° C., T 3 =70 to 150° C., T 4 =70 to 180° C., and T 1 <T 2 , T 2 <T 3 and T 3 <T 4 .
3. The process for producing an amphoteric electrolyte resin according to claim 1 , wherein the mixture contains no polymerization initiator; and T 1 , T 2 , T 3 and T 4 respectively satisfy the following expressions: T 1 =100 to 160° C., T 2 =100 to 200° C., T 3 =100 to 240° C., T 4 =100 to 270° C., and T 1 <T 2 , T 2 <T 3 and T 3 <T 4 .