Plate-shaped hydrotalcite with high aspect ratio, method for manufacturing same and resin composition

A plate-shaped hydrotalcite represented by a formula (1) below:

• (M2+)1−x(M3+)x(OH)2(An−)x/n·mH2O (1)
• wherein M2+ indicates at least one divalent metal, M3+ indicates at least one trivalent metal, An− indicates an n-valent anion, n indicates an integer of 1 to 6, and x and m are within respective ranges of 0.1≤x≤0.33 and 0≤m≤10,
• the plate-shaped hydrotalcite satisfying (A) to (E) below:
• (A) an average width of primary particles as measured using an SEM method is 1 μm or greater;
• (B) an average thickness of primary particles as measured using an SEM method is 80 nm or less;
• (C) a degree of monodispersity of width expressed by an equation below is 50% or greater:
• degree of monodispersity of width (%)=(average width of primary particles as measured using the SEM method/average width of secondary particles as measured using a laser diffraction method)×100;
• (D) a degree of monodispersity of thickness expressed by an equation below is 50% or greater:
• degree of monodispersity of thickness (%)=(average thickness of primary particles as measured using the SEM method/average thickness of secondary particles as measured using an SEM method)×100;
• and
• (E) an aspect ratio of secondary particles (average width of secondary particles as measured using the laser diffraction method/average thickness of secondary particles as measured using the SEM method) is 10 or greater;
• and
• a boehmite content in the plate-shaped hydrotalcite being 0.1 wt. % or less with respect to the plate-shaped hydrotalcite.