PURPOSE: To prevent cracks by coating the surface of natural stone plates or natural stone-like plates with a water glass containing a hardening agent, laminating an inorganic aggregate consisting essentially of specific silas balloons in a lamellar state to the coated plates, molding under pressure and hardening.
CONSTITUTION: 100 pts.wt. silas balloons comprising fine particles and coarse particles are blended with 30-150 pts.wt. calculated as solid content of a water glass such as Na2SiO3, 10-40 pts.wt. glass hardening agent such as Na2SiF6, further optionally ≥0.5 ps.wt. polymer binder such as PVA, 0.1-10 pts.wt. organic or inorganic reinforcing fibers having ≥1mm fiber length and ≥30 pts.wt. inorganic powder such as mica having ≥70μm particle diameter. The powdery granular mixture is press-molded and hardened at normal temperature or under heating to give inorganic light-weight plates. One side or both sides of these light-weight plates and one side of natural stone plates such as marble or natural stone-like plates are coated with a water glass-based adhesive prepared by mixing said water glass with a hardening agent and inorganic powder, and the light-weight plates are laminated to the natural stone or natural stone-like plates to give the objective light-weight decorative plates.
HASHIBA MASAHIRO
SHIMOJO YOSHINORI
