Abstract: A preparation for inhibiting scale formation in aqueous media with a high threshold activity is prepared by condensation of 2 moles of a mixture of acetic acid anhydride and an acetylhalide in the proportion of 0.2:1.8 to 1.8:0.2 with 0.6 moles to 1 mole crotonaldehyde, thereafter with 0.6 moles to 1 mole of acrylic acid, followed by condensation with 0.6 moles to 1 mole of maleic acid anhydride, and finally by oxidation with nitric acid without isolating any of the resulting intermediate products. Said preparation is added in amounts of 10 mg. to 200 mg. to each liter of aqueous medium to exert its scale formation inhibiting, chelating, sequestering, and/or complexing effect.

Abstract: Novel 1,4-bis-formyl cyclohexane polycarboxylic acids have proved of considerable value as agents capable of preventing and inhibiting scale formation in aqueous media. Especially valuable scale formation inhibiting and complexing agents are 1,4-bis-formyl cyclohexane-1,2,3,6-tetracarboxylic acid and 1,4-bis-formyl cyclohexane-1,2,3-tricarboxylic acid. They are prepared by oxidizing the corresponding bicyclo-(2,2,2)-octene(7) polycarboxylic acid-2,3-anhydrides. The novel nitrogen- and phosphorus-free acids have a surprisingly high threshold effectiveness and can be used in detergent and cleaning solutions in combination with conventional detergents and cleaning agents.