Method of preparing acrylic ion-transfer membranes

Claim 2

A process for forming ion-transfer membranes which comprises the following steps in sequence: preparing a reaction mixture consisting essentially of: (A) a major, non-ionic component selected from the group consisting of a hydrophobic acrylic monomer having the formula: ##STR4## where R is H or CH 3 and R 1 is methyl, ethyl or butyl, and mixtures of two or more of said hydrophobic monomers; (B) a minor, ionogenous acrylic monomer component selected from the group consisting of: (i) acrylic acid; (ii) methacrylic acid; (iii) monomers represented by the formula: ##STR5## wherein: R is H or CH 3 , and X is ##STR6## R 1 is alkylene or hydroxyalkylene R 2 , R 3 and R 4 are hydrogen, alkyl, or hydroxyalkyl, and Z - is a halide, acetate, or methyl sulfate ion; and, (iv) mixtures of two or more of said ionogenous acrylic monomers; and (C) an organic solvent, wherein the concentration of said major, non-ionic component in said solvent is in the range 2.5 to 7.5 molar, and the concentration of said minor, ionogenous component in said solvent is in the range 0.10 to 0.75 molar, and wherein the molar concentration of said ionogenous component is between 3 and 12% of the total monomer content in said reaction mixture; depositing a thin film of said reaction mixture on a substrate; and heating said deposited film in a substantially oxygen-free environment at a temperature between 55 degrees C. and 80 degrees C.

Claim 3

The process of claim 1 wherein said organic solvent is a water soluble alcohol.

Claim 4

The process of claim 1 wherein said organic solvent is a water soluble acid.

Claim 5

The process of claim 1 wherein said organic solvent is selected from the group consisting of ethanol and acetic acid.

Claim 6

The process of claim 1 wherein said reaction mixture further includes a polymerization initiator.

Claim 7

The process of claim 1 wherein said reaction mixture further includes a cross-linker.

Claim 8

The process of claim 5 wherein said polymerization initiator is azobisisobutyronitrile.

Claim 9

A process for forming ion-transfer membranes which comprises the following steps in sequence: preparing a reaction mixture consisting essentially of: (A) a major, non-ionic component selected from the group consisting of a hydrophobic acrylic monomer having the formula: ##STR7## where R is H or CH 3 and R 1 is methyl, ethyl or butyl, and mixtures of two or more of said hydrophobic monomers; (B) a minor, ionogenous acrylic monomer component selected from the group consisting of: (i) acrylic acid; (ii) methacrylic acid; (iii) monomers represented by the formula: ##STR8## wherein: R is H or CH 3 ,

Claim 10

A process for forming ion-transfer membranes which comprises the following steps in sequence: preparing a reaction mixture consisting essentially of: (A) a major, non-ionic component selected from the group consisting of a hydrophobic acrylic monomer having the formula: ##STR7## where R is H or CH 3 and R 1 is methyl, ethyl or butyl, and mixtures of two or more of said hydrophobic monomers; (B) a minor, ionogenous acrylic monomer component selected from the group consisting of: (i) acrylic acid; (ii) methacrylic acid; (iii) monomers represented by the formula: ##STR8## wherein: R is H or CH 3 ,

Claim 11

and X is ##STR9## R 1 is alkylene or hydroxyalkylene R 2 , R 3 and R 4 are hydrogen, alkyl, or hydroxyalkyl, and Z - is a halide, acetate, or methyl sulfate ion; and, (iv) mixtures of two or more of said ionogenous monomers; and (C) an organic solvent, wherein the concentration of said major, non-ionic component in said solvent is in the range 2.5 to 7.5 molar, and the concentration of said minor, ionogenous component in said solvent is in the range 0.10 to 0.75 molar, and wherein the molar concentration of said ionogenous component is between 2 and 12% of the total monomer content in said reaction mixture; heating said reaction mixture to a viscous consistency at a temperature between 55 and 80 degrees C. in a substantially oxygen-free environment; coating a substrate with a film of said viscous reaction mixture; and heating said deposited film to a temperature between 55 and 80 degrees C. in a substantially oxygen-free environment until said film becomes rubbery.

Claim 12

and X is ##STR9## R 1 is alkylene or hydroxyalkylene R 2 , R 3 and R 4 are hydrogen, alkyl, or hydroxyalkyl, and Z - is a halide, acetate, or methyl sulfate ion; and, (iv) mixtures of two or more of said ionogenous monomers; and (C) an organic solvent, wherein the concentration of said major, non-ionic component in said solvent is in the range 2.5 to 7.5 molar, and the concentration of said minor, ionogenous component in said solvent is in the range 0.10 to 0.75 molar, and wherein the molar concentration of said ionogenous component is between 2 and 12% of the total monomer content in said reaction mixture; heating said reaction mixture to a viscous consistency at a temperature between 55 and 80 degrees C. in a substantially oxygen-free environment; coating a substrate with a film of said viscous reaction mixture; and heating said deposited film to a temperature between 55 and 80 degrees C. in a substantially oxygen-free environment until said film becomes rubbery.

Claim 13

A process for forming ion-transfer membranes which comprises the following steps in sequence preparing a reaction mixture consisting essentially of: (A) a major, non-ionic component selected from the group consisting of a hydrophobic acrylic monomer having the formula: ##STR10## where R is H or CH 3 and R 1 is methyl, ethyl or butyl and mixtures of two or more of said hydrophobic monomers; (B) a minor, ionogenous acrylic monomer component selected from the group consisting of: (i) acrylic acid; (ii) methacrylic acid; (iii) monomers represented by the formula: ##STR11## wherein: R is H or CH 3 , and X is ##STR12## R 1 is alkylene or hydroxyalkylene R 2 , R 3 and R 4 are hydrogen, alkyl, or hydroxyalkyl, and Z - is a halide, acetate, or methyl sulfate ion; and, (iv) mixtures of two or more of said ionogenous monomers; and (C) an organic solvent, wherein the concentration of said major, non-ionic component in said solvent is in the range 2.5 to 7.5 molar, and the concentration of said minor, ionogenous component in said solvent is in the range 0.10 to 0.75 molar, and wherein the molar concentration of said ionogenous component is between 3 and 12% of the total monomer content in said reaction mixture; introducing a quantity of said reaction mixture into a mold cavity and thereafter maintaining said mold cavity in a substantially oxygen-free condition; heating said mold cavity to a temperature between 55 and 80 degrees C. and maintaining said temperature until the mold cavity contents becomes rubbery; and removing said rubbery contents from said mold cavity.

Claim 14

A process for forming ion-transfer membranes which comprises the following steps in sequence preparing a reaction mixture consisting essentially of: (A) a major, non-ionic component selected from the group consisting of a hydrophobic acrylic monomer having the formula: ##STR10## where R is H or CH 3 and R 1 is methyl, ethyl or butyl and mixtures of two or more of said hydrophobic monomers; (B) a minor, ionogenous acrylic monomer component selected from the group consisting of: (i) acrylic acid; (ii) methacrylic acid; (iii) monomers represented by the formula: ##STR11## wherein: R is H or CH 3 , and X is ##STR12## R 1 is alkylene or hydroxyalkylene R 2 , R 3 and R 4 are hydrogen, alkyl, or hydroxyalkyl, and Z - is a halide, acetate, or methyl sulfate ion; and, (iv) mixtures of two or more of said ionogenous monomers; and (C) an organic solvent, wherein the concentration of said major, non-ionic component in said solvent is in the range 2.5 to 7.5 molar, and the concentration of said minor, ionogenous component in said solvent is in the range 0.10 to 0.75 molar, and wherein the molar concentration of said ionogenous component is between 3 and 12% of the total monomer content in said reaction mixture; introducing a quantity of said reaction mixture into a mold cavity and thereafter maintaining said mold cavity in a substantially oxygen-free condition; heating said mold cavity to a temperature between 55 and 80 degrees C. and maintaining said temperature until the mold cavity contents becomes rubbery; and removing said rubbery contents from said mold cavity.

Claim 15

The process of claim 1, 8, or 9, wherein said ionogenous monomer is methacrylamidopropyltrimethylammonium chloride.

Claim 16

The process of claim 8 wherein said organic solvent is a water soluble alcohol.

Claim 17

The process of claim 8 wherein said organic solvent is a water soluble acid.

Claim 18

The process of claim 8 wherein said organic solvent is selected from the group consisting of ethanol and acetic acid.

Claim 19

The process of claim 8 wherein said reaction mixture further includes a polymerization initiator.

Claim 20

The process of claim 8 wherein said reaction mixture further includes a cross-linker.

Claim 21

The process of claim 8 wherein said polymerization initiator is azobisisobutyronitrile.

Claim 22

The process of claim 9 wherein said organic solvent is a water soluble alcohol.

Claim 23

The process of claim 9 wherein said organic solvent is a water soluble acid.

Claim 24

The process of claim 9 wherein said organic solvent is selected from the group consisting of ethanol and acetic acid.

Claim 25

The process of claim 9 wherein said reaction mixture further includes a polymerization initiator.

Claim 26

The process of claim 9 wherein said reaction mixture further includes a cross-linker.

Claim 27

The process of claim 9 wherein said polymerization initiator is azobisisobutyronitrile.