Patent ID: 7468387

Claim:
An imido-alkanpercarboxylic acid represented by formula (I): wherein A is wherein: R1 is hydrogen, chlorine, bromine, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, aryl, or alkylaryl, R2 is hydrogen, chlorine, bromine —SO 3 M, —CO 2 M, —CO 3 M or —OSO 3 M, M is hydrogen, an ammonium alkaline metal, or an alkaline-earth metal equivalent, and X is a C 1 -C 19 alkylene or an arylene; wherein said imido-alkanpercarboxylic acid is in a crystalline form of alpha that is stable at storage at the solid state, but when dispersed in water is capable of being transformed into one or more crystals of beta crystalline form that are stable in aqueous environment, wherein said one or more crystals of beta crystalline form have an average size of lower than 30 microns, and wherein the respective spectra of the alpha crystalline form obtained by X-ray Diffraction and Surface Infrared Spectroscopy techniques show, with respect to the spectra of the beta form of the same peracid, exhibit a different spectral X-ray image and a typical absorption shift in the 1697-1707 cm −1 zone by Surface Infrared Spectroscopy towards higher frequencies, of the order of 10 cm −1 .