Abstract: This surface-treated hydrotalcite is obtained by surface-treating a hydrotalcite having a compositional makeup represented by formula (1) and satisfies (A)-(C). This hydrotalcite has excellent dispersibility. (M2+)(1-x)(M3+)x(OH)2(An?)x/n·mH2O??(1) (Wherein, respective signs in formula (1) are as defined in the claims.) (A) The proportion of a surface-treating agent is 20-50 mass %. (B) The average width of primary particles is 5-120 nm. (C) The monodispersity is 75% or more.

Abstract: A hydrotalcite is represented by formula (1): (M2+)1-X(M3+)X(OH)2(An?)X/n·mH2O??(1), wherein M2+ indicates a divalent metal, M3+ indicates a trivalent metal, An? indicates an n-valent anion, n indicates an integer of 1 to 6, 0.17?x?0.36, and 0?m?10. The hydrotalcite has (A) a lattice strain in the <003> direction is 3×10?3 or less as measured using an X-ray diffraction method; (B) primary particles with an average width between 5 nm and 200 nm inclusive per a SEM method; and (C) a degree of monodispersity of 50% or greater (degree of monodispersity (%)=(average width of primary particles as measured using the SEM method/average width of secondary particles as measured using a dynamic light scattering method)×100). A resin containing the hydrotalcite, a suspension containing the hydrotalcite and a method for producing the hydrotalcite are disclosed.