Method of preparing polymer gels using chelated aluminum salt

Claim 2

A PROCESS FOR PREPARING A POLYMER GEL WHICH COMPRISES: A. MIXING THE FOLLOWING INGREDIENTS:

Claim 3

FIRST WATER SOLUTION COMPRISING ABOUT 0.1 TO 5 PERCENT BY WEIGHT, BASED ON THE TOTAL WEIGHT OF SOLUTION OF A WATER SOLUBLE ALUMINUM SALT, AN ALUMINUM CHELANT SELECTED FROM THE GROUP CONSISTING OF A. ALPHA-HYDROXY MONOCARBOXYLIC ACIDS HAVING 3 TO 4 CARBON ATOMS, B. ALPHA-HYDROXY TRICARBOXYLIC ACIDS, AND BON ATOMS, C. BETA-HYDROXY TRICARBOXYLIC ACIDS, HAVING 3 TO 4 CARD. DICARBOXYLIC ACIDS OF 2 TO 4 CARBON ATOMS, SAID CHELANT BEING PRESENT IN AN AMOUNT SUCH THAT THE CHELANT/ALUMINUM MOLAR RATIO IS ABOUT 0.2 TO 2 AND A BASE IN AN AMOUNT SUFFICIENT TO ADJUST THE PH OF SAID FIRST SOLUTION TO ABOUT 4 TO 9; AND

Claim 4

FIRST WATER SOLUTION COMPRISING ABOUT 0.1 TO 5 PERCENT BY WEIGHT, BASED ON THE TOTAL WEIGHT OF SOLUTION OF A WATER SOLUBLE ALUMINUM SALT, AN ALUMINUM CHELANT SELECTED FROM THE GROUP CONSISTING OF A. ALPHA-HYDROXY MONOCARBOXYLIC ACIDS HAVING 3 TO 4 CARBON ATOMS, B. ALPHA-HYDROXY TRICARBOXYLIC ACIDS, AND BON ATOMS, C. BETA-HYDROXY TRICARBOXYLIC ACIDS, HAVING 3 TO 4 CARD. DICARBOXYLIC ACIDS OF 2 TO 4 CARBON ATOMS, SAID CHELANT BEING PRESENT IN AN AMOUNT SUCH THAT THE CHELANT/ALUMINUM MOLAR RATIO IS ABOUT 0.2 TO 2 AND A BASE IN AN AMOUNT SUFFICIENT TO ADJUST THE PH OF SAID FIRST SOLUTION TO ABOUT 4 TO 9; AND

Claim 5

A SECOND WATER SOLUTION COMPRISING ABOUT 0.1 TO 2.5 PERCENT BY WEIGHT, BASED ON THE TOTAL WEIGHT OF SAID SOLUTION, OF A WATER SOLUBLE COPOLYMR OF ACRYLAMIDE AND ACRYLIC ACID OR A METAL SALT OF ACRYLIC ACID; THE RELATIVE PROPORTIONS OF SOLUTION 1) AND 2) BEING SUFFICIENT TO PROVIDE IN THE MIXTURE THEREOF A MOLAR RATIO OF ALUMINUM ATOMS TO CARBOXYL GROUPS INT E COPOLYMER OF ABOUT 0.018 TO 90 AND A COPOLYMER CONTENT OF ABOUT 0.09 TO 2.3 PERCENT BY WEIGHT OF THE TOTAL WATER PRESENT; AND B. ADJUSTING THE PH OF THE TOTAL MIXTURE TO ABOUT 4.6 TO 8.3.

Claim 6

A SECOND WATER SOLUTION COMPRISING ABOUT 0.1 TO 2.5 PERCENT BY WEIGHT, BASED ON THE TOTAL WEIGHT OF SAID SOLUTION, OF A WATER SOLUBLE COPOLYMR OF ACRYLAMIDE AND ACRYLIC ACID OR A METAL SALT OF ACRYLIC ACID; THE RELATIVE PROPORTIONS OF SOLUTION 1) AND 2) BEING SUFFICIENT TO PROVIDE IN THE MIXTURE THEREOF A MOLAR RATIO OF ALUMINUM ATOMS TO CARBOXYL GROUPS INT E COPOLYMER OF ABOUT 0.018 TO 90 AND A COPOLYMER CONTENT OF ABOUT 0.09 TO 2.3 PERCENT BY WEIGHT OF THE TOTAL WATER PRESENT; AND B. ADJUSTING THE PH OF THE TOTAL MIXTURE TO ABOUT 4.6 TO 8.3.

Claim 7

a second water solution comprising about 0.1 to 2.5 percent by weight, based on the total weight of said solution, of a water soluble copolymer of acrylamide and acrylic acid or a metal salt of acrylic acid; the relative proportions of solutions 1) and 2) being sufficient to provide in the mixture thereof a molar ratio of aluminum atoms to carboxyl groups in the copolymer of about 0.018 to 90 and a copolymer content of about 0.09 to 2.3 percent by weight of the total water present; and B. adjusting the pH of the total mixture to about 4.6 to 8.3.

Claim 8

a second water solution comprising about 0.1 to 2.5 percent by weight, based on the total weight of said solution, of a water soluble copolymer of acrylamide and acrylic acid or a metal salt of acrylic acid; the relative proportions of solutions 1) and 2) being sufficient to provide in the mixture thereof a molar ratio of aluminum atoms to carboxyl groups in the copolymer of about 0.018 to 90 and a copolymer content of about 0.09 to 2.3 percent by weight of the total water present; and B. adjusting the pH of the total mixture to about 4.6 to 8.3.

Claim 9

The process of claim 1 wherein step B. is accomplished by adjusting the pH of the copolymer solution to about 2 to 9 prior to mixing solutions (1) and (2).

Claim 10

The process of claim 1 where the aluminum salt is aluminum sulfate and the chelate is citric acid.

Claim 11

The process of claim 1 where the copolymer is a copolymer of 50 to 99 percent acrylamide and 50 to 1 percent by weight of a comonomer selected from the class consisting of acrylic acid and water soluble metal salts of acrylic acid.

Claim 12

The process of claim 4 where the comonomer is sodium acrylate.

Claim 13

The process of claim 5 where the aluminum salt is aluminum sulfate and the chelant is citric acid.