Water-soluble copolymer and use thereof as dispersant for suspension of particles

A process for preparing a copolymer, the process comprising:

• conducting a polymerization reaction of compound (a) and compound (b) in the presence of water, an initiating compound, and an activating compound, thereby forming a polymerized compound,
• wherein the compound (a) is at least one acid selected from the group consisting of acrylic acid and methacrylic acid;
• the compound (b) is a compound of formula (I):
• wherein
• each X independently represents a linear or branched C3-alkylene group;
• n represents a whole or decimal number ranging from 1 to 5;
• L represents a direct bond or a CH2 group;
• R1 represents H, CH3 or C(O)OH;
• and
• R2 represents H or C(O)OH;
• the initiating compound is at least one compound selected from the group consisting of hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate and the activating compound comprises an alkali metal hypophosphite;
• and
• neutralizing the polymerized compound completely with at least one compound selected from the group consisting of MgO, CaO, an alkali metal hydroxide, and an alkaline earth metal hydroxide,
• wherein the neutralization is carried out after the polymerization reaction,
• wherein a weight-average molecular weight (MW) of the copolymer ranges from 1000 to 6000 g/mol.

An aqueous solution of a copolymer obtained by a process comprising:

• conducting a polymerization reaction of compound (a) and compound (b) in the presence of water, an initiating compound, and an activating compound, thereby forming a polymerized compound,
• wherein the compound (a) is at least one acid selected from the group consisting of acrylic acid and methacrylic acid;
• the compound (b) is at least one compound selected from the group consisting of formula (II), (III) and (IV):
• wherein
• each X independently represents a linear or branched C3-alkylene group;
• n represents a whole or decimal number ranging from 1 to 5;
• L represents a direct bond or a CH2 group;
• R1 represents H, CH3 or C(O)OH;
• and
• R2 represents H or C(O)OH;
• with the proviso that when (b) is a compound of formula (III), the combination X is a linear C3-alkylene group, n is 1, L is a CH2 group, and R1 and R2 are H, is excluded,
• the initiating compound is at least one compound selected from the group consisting of hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate and the activating compound comprises an alkali metal hypophosphite;
• and
• neutralizing the polymerized compound completely with at least one compound selected from the group consisting of MgO, CaO, an alkali metal hydroxide, and an alkaline earth metal hydroxide,
• wherein a weight-average molecular weight (MW) of the copolymer ranges from 1000 to 6000 g/mol.

A process for preparing a copolymer, the process comprising:

• conducting a polymerization reaction of compound (a) and compound (b) in the presence of water, an initiating compound, and an activating compound, thereby forming a polymerized compound,
• wherein the compound (a) is at least one acid selected from the group consisting of acrylic acid and methacrylic acid;
• the compound (b) is at least one compound selected from the group consisting of (II), (III) and (IV):
• wherein
• each X independently represents a linear or branched C3-alkylene group;
• n represents a whole or decimal number ranging from 1 to 5;
• L represents a direct bond or a CH2 group;
• R1 represents H, CH3 or C(O)OH;
• and
• R2 represents H or C(O)OH;
• the initiating compound is at least one compound selected from the group consisting of hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate and the activating compound comprises an alkali metal hypophosphite;
• and
• neutralizing the polymerized compound completely or partially with at least one compound selected from the group consisting of MgO, CaO, an alkali metal hydroxide, and an alkaline earth metal hydroxide.

An aqueous solution of a copolymer obtained by a process comprising:

• conducting a polymerization reaction of compound (a) and compound (b) in the presence of water, an initiating compound, and an activating compound, thereby forming a polymerized compound,
• wherein the compound (a) is at least one acid selected from the group consisting of acrylic acid and methacrylic acid;
• wherein the compound (a) further comprises at least one other acid selected from the group consisting of itaconic acid and maleic acid;
• the compound (b) is a compound of formula (I):
• wherein
• each X independently represents a linear or branched C3-alkylene group;
• n represents a whole or decimal number ranging from 1 to 5;
• L represents a direct bond or a CH2 group;
• R1 represents H, CH3 or C(O)OH;
• and
• R2 represents H or C(O)OH;
• the initiating compound is at least one compound selected from the group consisting of hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate and the activating compound comprises an alkali metal hypophosphite;
• and
• neutralizing the polymerized compound completely with at least one compound selected from the group consisting of MgO, CaO, an alkali metal hydroxide, and an alkaline earth metal hydroxide,
• wherein a weight-average molecular weight (MW) of the copolymer ranges from 1000 to 6000 g/mol.