Production of polymaleic acid
AssigneeKao Corporation
InventorsYasuhisha Fukumoto, Moboru Moriyama
Life of this patent
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Abstract
A polymer or copolymer of maleic acid is produced by neutralizing (I) maleic acid in an aqueous medium with (III) an alkali metal hydroxide or ammonia at a molar ratio of (I) to (III) in the range of 100:0 to 100:90, polymerizing (I) with a polymerization initiator, adding (III) a further amount of the alkali metal hydroxide or ammonia at a molar ratio of (I) to (III) in the range of 100:100 to 100:130 in total through the previous addition and this addition and continuing the polymerization to the complete effect.
Claims11
A process for preparing a homoplymer of maleic acid, which comprises the steps of:
- neutralizing a monomer of (I) maleic acid or maleic anhydride in an aqueous medium with (III) an alkali metal hydroxide or ammonia so that the molar ratio of (I) to (III) in the aqueous medium is in the range of 100:00 to 100:90,
- beginning the polymerization of the monomer in the presence of a polymerization initiator,
- adding a further amount of said alkali metal hydroxide or ammonia so that the molar ratio of (I):(III) in the aqueous medium is from 100:100 to 100:130,
- then completing the polymerization of said monomer (I).
A process for producing a polymaleate homopolymer having a molecular weight of from 200 to 2000 and having a narrow molecular weight distribution, which comprises:
- providing a solution of (A) maleic acid monomer or maliec anhydride monomer containing from 0 to 90 mols of (B) alkali metal hydroxide or ammonia, per 100 mols of (A), in a solvent consisting of at leasta 60 percent by weight of water and up to 40 percent by weight of an alcohol or ketone, said solution containing from 30 to 85 percent by weight of said monomer,
- then polymerizing said monomer in the presence of an amount of water-soluble polymerization initiator effective to initiate polymerization of said monomer, at a polymerization temperature of from 60.degree. to 160.degree. C.;
- adding a further amount of (B) to said solution so that the molar ratio of (A)/(B) in said solution is from 100/100 to 100/130;
- and then completing the polymerization of said monomer so that an aqueous solultion of a polymaleate homopolymer is formed.
A process for producing a polymaleate homopolymer having a molecular weight of from 200 to 2000 and having a narrow molecular weight distribution, which comprises:
- providing an aqueous solution of (A) maleic acid monomer or maleic anhydride monomer and from 0 to 90 mols of (B) alkali metal hydroxide or ammonia, per 100 mols of (A), said solution containing from 30 to 85 percent by weight of said monomer,
- then polymerizing said monomer in the presence of an amount of water-soluble polymerization initiator effective to initiate polymerization of said monomer, at a polymerization temperature of from 60.degree. to 160.degree. C.;
- adding a further amount of (B) to said solution so that the molar ratio of (A)/(B) in said solution is from 100/100 to 100/130;
- adding an additional amount of said initiator to said solution;
- and then completing the polymerization of said monomer so that an aqueous solution of a polymaleate homopolymer is formed.
Dependencies are inferred from the claim text.