Abstract: There is provided a far infrared radiator capable of highly activating methane gas prior to combustion to thereby attain an enhancement of thermal efficiency at combustion. In a passage of methane gas prior to combustion, there is positioned absorbent material (58) produced by mixing at least carbon with tourmaline as an absorption material of absorptivity higher than that of the material of the methane gas passage. Energy-absorbing coating (59) is applied to an fixed on the external surface of the absorbent material, and on a circumferential surface of the energy-absorbing coating there are positioned magnet (54) and far infrared radiator (57) produced by mixing tourmaline with at least iron powder and carbon.

Abstract: There is provided a far infrared radiator capable of highly activating methane gas prior to combustion to thereby attain an enhancement of thermal efficiency at combustion. In a passage of methane gas prior to combustion, there is positioned absorbent material (58) produced by mixing at least carbon with tourmaline as an absorption material of absorptivity higher than that of the material of the methane gas passage. Energy-absorbing coating (59) is applied to an fixed on the external surface of the absorbent material, and on a circumferential surface of the energy-absorbing coating there are positioned magnet (54) and far infrared radiator (57) produced by mixing tourmaline with at least iron powder and carbon.

Abstract: An adhesive composition can be provided which comprises a vinyl acetate polymer emulsion containing acetoacetylated polyvinyl alcohol as a protective colloid and a calcium silicate alone or the calcium silicate and an isocyanate compounded therein, which can solve the disadvantages observed in the adhesives of systems in which the isocyanates are added to the emulsions like the prior art, and which retains the adhesive strength for a long time, particularly has a little reduction in initial adhesive strength, and is excellent in water resistance (water-resistant adhesion) and also in heat resistance (heat-resistant adhesion) compared to those of the prior-art adhesives.