To improve impact resistance and to prevent the design of a surface decorative layer of a composite building material, from being distorted even if the decorative layer is impacted, by allowing a core member constituting the composite building material having the decorative layer with a specific thickness formed at least on one surface thereof to contain an inorganic amorphous body internally having fibrous materials.
Decorative layers 5 each formed of a decorative veneer are arranged on both front and rear surfaces of a core member 1, and a reinforcing layer 6 is interposed between the core member 1 and each decorative layer 5 having a thickness of 0.1-10 mm, to thereby form a composite building material. The core member 1 contains an amorphous body 2 which internally contains organic fibrous materials 3 and inorganic fine particles 4, and the reinforcing layer 6 is constituted of a fibrous backing 6b impregnated with a resin 6a. The amorphous body 2 is an inorganic amorphous compound generated by solution treatment or hydration of two or more kinds of oxides, which compound serves as a strength manifestation material. In addition, the fibrous materials 3 are dispersed in the amorphous body 2 to improve a fracture toughness value, leading to improved bending strength value and impact resistance. Therefore, even if an impact acts, a gouge is rarely formed, whereby the design of the decorative layer 5 is not distorted.
OGAWA TETSUJI
SATO KENJI
NOMURA TOSHIHIRO
