Process for preparing an aqueous copolymer solution

• US 5,750,781 A
• Filed: 06/07/1995
• Issued: 05/12/1998
• Est. Priority Date: 06/20/1994
• Status: Expired due to Fees

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Yamamoto, Satoshi, Yoshida, Yoshifumi, Tanigawa, Akira
• Primary Examiner(s): O SULLIVAN, PETER G
• Application Number:
  US08/485,143
• Time in Patent Office: 1,070 Days
• Field of Search: 252/344, 252/341, 210/708, 562/565, 564/153
• US Class Current: 564/153
• CPC Class Codes: C08F 220/56 Acrylamide; Methacrylamide
• CPC Class Codes: C08F 226/04 Diallylamine

Abstract

A process for preparing an aqueous solution of an ionic copolymer having a copolymer concentration of 20 % by weight or less and a viscosity of 20 ps or more at 25° C. which comprises conducting copolymerization of an acrylamide compound(B) with a diallylamine compound(A) by continuously adding an aqueous solution of (B) having a concentration of 30% by weight or less to an aqueous solution of the diallylamine compound(A) having a concentration of 5% by weight or more and less than 10% by weight, and this process exhibit high conversion of diallylamine compounds, of which reactivity is low, and a copolymer having a high molecular weight can be obtained.

Claims

1. A process for preparing an aqueous solution of an ionic copolymer having a copolymer concentration of 20% by weight or less and a viscosity of 20 ps or more at 25°

C., which comprises;

conducting copolymerization of a diallylamine compound (A) represented by the following formula (I);

##STR3## wherein R¹ and R² each independently represents hydrogen or a methyl group, R³ and R⁴ each independently represents hydrogen or an alkyl group having 1-6 carbon atoms, and X^- is an acid anion, and an acrylamide compound (B) represented by the following formula (II);

##STR4## wherein R⁵ represents hydrogen or a methyl group, and R⁶ and R⁷ each independently represents hydrogen or an alkyl group having 1-4 carbon atoms, by continuously adding an aqueous solution of the acrylamide compound (B) having a concentration of the acrylamide compound (B) of 30% by weight or less to an aqueous solution of diallylamine compound (A) having a concentration of the diallylamine compound (A) of 5% by weight or more and less than 10% by weight.

2. A process according to claim 1, wherein the amount of diallylamine compound (A) is 1-70% by mole and the amount of acrylamide compound (B) is 30-99% by mole based on the total molar amount of the monomers (A) and (B).

3. A process according to claim 1 wherein the amount of diallylamine compound (A) is 10-35% by mole and the amount of acrylamide compound (B) is 65-90% by mole based on the total molar amount of the monomers (A) and (B).

4. A process according to claim 1 wherein a carboxylic compound (C) selected from the group consisting of an α

, β

-unsaturated monocarboxylic acid and an α

, β

-unsaturated dicarboxylic acid is also added continuously to the solution containing the diallylamine compound (A).

5. A process according to claim 4 wherein the amount of carboxylic acid compound (C) is not more than 20 % by mole based on the total molar amount of the monomers (A), (B) and (C).