Organic-inorganic composite particles and production process therefor

A process for producing organic-inorganic composite particles, which comprises:

• a condensation step of hydrolyzing and condensing at least one silicon compound selected from the group consisting of compounds represented by General Formula (1) below and derivatives thereof:
• R'.sub.m Si(OR").sub.4-m ( 1)
• wherein said derivatives of said compound of Formula (1) comprise
• (A) substituted compounds of said silicon compound of Formula (1) wherein at least some of the hydrolyzable groups are substituted by a carboxyl group and/or .beta.-dicarbonyl group, or
• (B) a lower condensation product obtained by partial hydrolysis and condensation of said silicon compounds of Formula (1), substituted compounds (A) and mixtures thereof,
• where:
• R' indicates a monovalent group selected from the group consisting of alkyl groups of 1-10 carbon atoms, aryl groups of 6-10 carbon atoms and unsaturated aliphatic residual groups of 2-4 carbon atoms, which may have a substituent group:
• R" indicates a hydrogen atom or a monovalent group selected from the group consisting of alkyl groups of 1-5 carbon atoms and acyl groups of 2-5 carbon atoms;
• m indicates an integer of 0-3;
• when m is 2, the two R's may be either different from or identical with one another;
• when m is 3, the three R's may differ from one another, or two or more of the R's may be identical;
• when 4-m is 2, the two OR"s may be either different from or identical with one another;
• when 4-m is 3, the three OR"s may be either different from each other, or two or more of the OR"s may be identical;
• and
• when 4-m is 4, the four OR"s may be different from each other, or two or more of the OR"s may be identical;
• with the proviso that when a single compound of Formula 1 is used, said compound is selected from the group consisting of compounds where m=1, and that when 2 or more silicon compounds used together, at least one of said compounds of Formula 1 is selected from the group consisting of compounds of m=1 in said Formula (1) and derivatives thereof;
• and a compound selected from the group consisting of compounds of m=0 in said Formula (1) and derivatives thereof;
• to give condensed particles;
• and
• a heat-treatment step of treating said condensed particles by heating at a temperature of 100.degree. C. to 1000.degree. C. to obtain particle bodies of organic-inorganic composite particles.