Resin composition and resin molded body thereof

A resin molded body comprising:

• metal oxide particles with a negative coefficient of linear expansion at 0° C. to 60° C.;
• and
• a resin with a positive coefficient of linear expansion at 0° C. to 60° C.,
• wherein:
• the metal oxide particles change in metal element valence during crystal phase transition;
• a surface of the metal oxide particles is provided with a compound containing at least one metal element selected from the group consisting of Si, Al, and Ti;
• the compound containing the metal element is a condensate of an alkoxide compound represented by formula (1) or (2):
• SiR1n1R2m1 (1)
• wherein:
• R1 is a functional group selected from the group consisting of a methyl group, a methoxy group, and an ethoxy group;
• R2 is a functional group having 8 or less carbon atoms and having an end portion selected from the group consisting of any one of epoxy, amine, imine, and (meth)acryloxy groups;
• n1 is a positive integer;
• m1 is a positive integer or 0;
• and
• n1+m1 is 4;
• M4R3n2R4m2 (2),
• wherein:
• M4 is Al or Ti;
• R3 is a functional group selected from the group consisting of an alkyl group having 8 or less carbon atoms and an alkoxy group having 8 or less carbon atoms;
• R4 is a functional group having 8 or less carbon atoms and having an end portion selected from the group consisting of any one of epoxy, amine, imine, and (meth)acryloxy groups, phosphoric acid ester, and sulfonic acid ester;
• when M4 is Al, n2 is a positive integer, m2 is a positive integer or 0, and n2+m2 is 3;
• and
• when M4 is Ti, n2 is a positive integer, m2 is a positive integer or 0, and n2+m2 is 4;
• and
• the metal oxide particles are particles of a metal oxide represented by formula (A) or (B):
• (Bi1-x1M1x1)(Ni1-x2M2x2)Oy (A),
• wherein:
• M1 is at least one metal element selected from the group consisting of lanthanoids, Y, and In;
• M2 is at least one metal element selected from the group consisting of Al, V Cr, Mn, Fe, Co, Ga, and Sb;
• x1, x2, and y are such that x1 is 0.02 to 0.15, x2 is 0.02 to 0.50, and y is 3 or less;
• BiNi1-xM3xOy (B),
• wherein:
• M3 is at least one metal element selected from the group consisting of Al, V, Cr, Mn, Fe, Co, Ga, and Sb;
• x is 0.02 to 0.50;
• and
• y is 3 or less.

A method of producing a resin molded body which includes metal oxide particles with a negative coefficient of linear expansion at 0° C. to 60° C. and a resin with a positive coefficient of linear expansion at 0° C. to 60° C., wherein the metal oxide particles change in metal element valence during crystal phase transition, the method comprising:

• providing a compound containing at least one metal element selected from the group consisting of Si, Al, and Ti on a surface of the metal oxide particles;
• mixing the metal oxide particles provided with the compound with the resin;
• and
• molding the resin mixed with the metal oxide particles provided with the compound at a temperature of 100° C. to 300° C.,
• wherein the compound containing the metal element is a condensate of an alkoxide compound represented by formula (1) or (2):
• SiR1n1R2m1 (1),
• wherein:
• R1 is a functional group selected from the group consisting of a methyl group, a methoxy group, and an ethoxy group;
• R2 is a functional group having 8 or less carbon atoms and having an end portion selected from the group consisting of any one of epoxy, amine, imine, and (meth)acryloxy groups;
• n1 is a positive integer;
• m1 is a positive integer or 0;
• and
• n1+m1 is 4;
• M4R3n2R4m2 (2),
• wherein:
• M4 is Al or Ti;
• R3 is a functional group selected from the group consisting of an alkyl group having 8 or less carbon atoms and an alkoxy group having 8 or less carbon atoms;
• R4 is a functional group having 8 or less carbon atoms and having an end portion selected from the group consisting of any one of epoxy, amine, imine, and (meth)acryloxy groups, phosphoric acid ester, and sulfonic acid ester;
• when M4 is Al, n2 is a positive integer, m2 is a positive integer or 0, and n2+m2 is 3;
• and
• when M4 is Ti, n2 is a positive integer, m2 is a positive integer or 0, and n2+m2 is 4, and
• wherein the metal oxide particles are particles of a metal oxide represented by formula (A) or (B):
• (Bi1-x1M1x1)(Ni1-x2M2x2)Oy (A),
• wherein:
• M1 is at least one metal element selected from the group consisting of lanthanoids, Y, and In;
• M2 is at least one metal element selected from the group consisting of Al, V, Cr, Mn, Fe, Co, Ga, and Sb;
• x1, x2, and y are such that x1 is 0.02 to 0.15, x2 is 0.02 to 0.50, and y is 3 or less;
• BiNi1-xM3xOy (B),
• wherein:
• M3 is at least one metal element selected from the group consisting of Al, V, Cr, Mn, Fe, Co, Ga, and Sb;
• x is 0.02 to 0.50;
• and
• y is 3 or less.

A resin composition comprising:

• metal oxide particles having a negative coefficient of linear expansion at 0° C. to 60° C. and represented by formula (B):
• BiNi1-xFexO3 (B), where x is 0.02 to 0.50;
• and
• a thermoplastic resin with a positive coefficient of linear expansion at 0° C. to 60° C.,
• wherein the metal oxide particles change in metal element valence during crystal phase transition, and a surface of the metal oxide particles is provided with a protective layer containing Si,
• wherein the protective layer is a condensate of an alkoxide compound having one functional group selected from the group consisting of an epoxy functional group, an amino functional group, and a methacryl functional group, the alkoxide compound reacting under neutral conditions, and
• wherein a converted value of a coefficient of linear expansion of the metal oxide particles in the thermoplastic resin is −178 ppm/° C. to −42 ppm/° C.