Method for producing silica composite particle

A method for producing a silica composite particle, the method comprising:

• (i) providing a silica particle dispersion liquid having a silica particle content of about 20 mass % or more;
• (ii) mixing and reacting a compound represented by formula (Si) and the silica particle dispersion liquid to obtain a slurry, where the compound represented by formula (S1) is:
• Si(R1)n(OR2)4-n Formula (S1)
• where R1 and R2 each independently represent an alkyl group or an aryl group, and n represents an integer of 1 or more and 3 or less;
• (iii) providing at least one compound in which an aluminum atom bonds to an organic group through oxygen;
• and
• (iv) then mixing and reacting the slurry with the at least one compound to form the silica composite particle in which a coverage X of a surface of the silica composite particle with the aluminum atoms of the at least one compound is about 0.01 at % or more and about 30 at % or less,
• where the coverage X is calculated from a ratio of the aluminum Al/Si detected by X-ray photoelectron spectroscopy.