US 5,064,563 A · Process for producing and use of maleic acid (co-) polymer salt improved in biodegradability

Abstract

A specially defined amount of hydrogen peroxide is used as a polymerization catalyzer; a specially defined amount and a specially defined kind of a polyvalent metal ion is used; and a specially defined amount of an alkaline substance is used, in order to polymerize a monomer component consisting essentially of only maleic acid, or a monomer component composed of maleic acid and another water-soluble ethylenically unsaturated monomer, in a specially defined proportion in water, whereby a maleic acid polymer salt, preferably a copolymer salt, of improved biodegradability is produced. The maleic acid polymer salt obtained is superior in biodegradability, has a low residual monomer content, and is useful as a detergent builder and as a scale inhibitor, etc.

Claims21

Dependent claims

A process for producing a maleic acid polymer salt having improved biodegradability which comprises polymerizing a monomer component composed of 75.about.100 weight % of maleic acid (A) and the remainder another water-soluble ethylenically unsaturated monomer (B) in a medium consisting essentially of an aqueous solution containing 12.about.150 g of hydrogen peroxide per mole of the monomer component as the polymerization catalyzer;

0.3.about.500 ppm, based on the weight of the monomer component, of at least one kind of polyvalent metal ion selected from the group consisting of a vanadium containing ion, an iron ion, and a copper ion;
and an amount of an alkaline substance added prior to polymerization sufficient to neutralize more than 0 and up to 45 mole % of all the acid in the monomer component to thereby produce a polymer salt comprising neutralized maleic acid having improved biodegradability.

A detergent builder composed of a maleic acid polymer salt, improved in biodegradability, which is obtained by polymerizing a monomer component composed of 75.about.100 weight % of the maleic acid (A) other water-soluble and the remainder being another in an aqueous solution containing 12.about.150 g per mole of the monomer component of hydrogen peroxide as a polymerization catalyzer;

0.3.about.500 ppm based on the weight of the monomer component of at least one kind of polyvalent metal ion selected from a vanadium containing ion, an iron ion, and a copper ion;
and sufficient alkaline substance added prior to polymerization to neutralize more than 0 and up to 45 mole % of all of the acid in the monomer component.

A scale inhibitor composed of a maleic acid polymer salt, improved in biodegradability, which is obtained by polymerizing a monomer component composed of 75.about.100 weight % of the maleic acid (A) and the remainder being another water-soluble ethylenically unsaturated monomer (B) in an aqueous solution containing 12.about.150 g of hydrogen peroxide per mole of the monomer component as a polymerization catalyzer;

0.3.about.500 ppm, based on the weight of the monomer component, of at least one kind of polyvalent metal ion selected from a vanadium containing ion, an iron ion, and a copper ion;
and sufficient alkaline substance added prior to polymerization to neutralize more than 0 and up to 45 mole % of all of the acid in the monomer component.

Dependencies are inferred from the claim text.

Process for producing and use of maleic acid (co-) polymer salt improved in biodegradability

Life of this patent

Process for producing and use of maleic acid (co-) polymer salt improved in biodegradability

Life of this patent

Abstract

Claims21