PURPOSE: To obtain a cement plate material having excellent weather resistance free from efflorescence by coating an unhardened cement layer with an emulsion coating compound of specific resin and curing the cement plate material at ≥the second-order transition point of the resin.
CONSTITUTION: An unhardened cement layer is coated with an emulsion coating compound of a resin having ≥35°C second-order transition temperature of skeleton to give the aimed plate material. When the unhardened cement material is cured at ≥ the second-order transition temperature as mentioned above, the melted resin is permeated into gaps of the cement particles and integrated with a cement matrix to form an extremely dense surface layer. Consequently, a surface coating film having extremely low water permeability is formed after curing and hardening. An emulsion coating compound of acrylic resin having 0.05μ average particle diameter and 40°C transition temperature is suitable as the emulsion coating compound and the application amount is sufficiently about 1g/200cm2.
MINEMOTO TAKASHI
MAEKAWA TOYOHIKO
