Modified polyethylenephosphinic acids and their salts

The polymeric phosphinic acid or its salt of the formula

• 14
• where X=H, 1/m metal, amine-H+

The polymeric phosphinic acid or its salt of the formula

• 15
• where X=H, 1/m metal, amine-H+
• where R3 and R4=ethyl, propyl, butyl

A process for preparing polymeric phosphinic acids and theirs salts of the formula (I), which comprises reacting hypophosphorous acid and/or its alkali metal salts with alkynes (acetylenes) of the formula (II)

• R1—C≡C—R2 (II)
• where R1 and R2 are identical or different and are hydrogen, a carboxy group, a carboxylic acid derivative, an unsubstituted or substituted alkyl group having from 1 to 10 carbon atoms, phenyl, benzyl, or alkyl-substituted aromatic systems, and oxidizing the resultant phosphonous acid end groups to give phosphonic acid end groups.

A process for preparing polymeric phosphinic acids and theirs salts of the formula (I), which comprises reacting hypophosphorous acid and/or its alkali metal salts with alkynes (acetylenes) of the formula (II)

• R1—C≡C—R2 (II)
• where R1 and R2 are identical or different and are hydrogen, a carboxy group, a carboxylic acid derivative, an unsubstituted or substituted alkyl group having from 1 to 10 carbon atoms, phenyl, benzyl, or alkyl-substituted aromatic systems, and reacting the resultant phosphonous acid end groups with olefins to give phosphinic acid end groups.