JPH0144666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a porous calcium silicate molded body, and in particular a calcium silicate laminated heat insulating body which is integrally laminated with a layer that blocks radiant heat interposed therebetween.

Calcium silicate molded bodies are widely used as wall materials for heat insulation and sound insulation because they are lightweight and have low thermal conductivity, and are inorganic materials and fire resistant. On the other hand, it is also used as a heat insulating material to form heat insulating tanks such as cold storage tanks, constant temperature baths, and heating furnaces. There are heat transfer factors such as conductive heat transfer of the material, air conduction and convection heat transfer of the heat insulating layer, and radiation heat transfer as factors that determine the performance as a heat insulating material. To reduce conductive heat transfer in a material, it is sufficient to manufacture the material with a material that reduces thermal conductivity, and to reduce heat transfer due to conduction and convection in an air layer, the air in the insulation layer can be evacuated to create a vacuum. A further reduction in radiant heat transfer was achieved by interposing a shiny metal foil between the materials to reflect and block the heat incident on the heat insulating layer.

However, since the calcium silicate molded material has low thermal conductivity and is porous, when it is evacuated to form a vacuum insulation layer, an extremely wide vacuum space is obtained and the conduction of the air layer is reduced. Heat transfer and convective heat transfer can be reduced very effectively. As yet another means for reducing the heat transfer of radiant heat, in order to reflect and block incoming heat rays, metal foil such as aluminum with a glossy surface is coated with the molded calcium silicate molded body. During the stacking of each unit, the units were inserted as they were or glued together with an adhesive. However, with this method of radiant heat shielding, the fixation of the metal foil is unstable, the adhesive deteriorates over time, making it difficult to integrate, the metal foil often moves, and turning is complicated. There were various practical inconveniences.

The present invention was made in view of the above-mentioned current situation, and its characteristics are that a calcium silicate molded body is provided with a radiant heat shielding function, and that the molded body is manufactured as an integral part and a radiant heat shielding layer is laminated as an intervening layer, thereby solving the above-mentioned disadvantages. This is a calcium silicate laminated heat insulator that maintains the light weight characteristic of calcium silicate without separation of the shielding layer, and has excellent strength and heat insulation performance. Hereinafter, one embodiment of the laminated heat insulating body of the present invention will be described based on the drawings.

In the figure, 1A, 1B, and 1C are porous calcium silicate commercially available, which are obtained by mixing silicic acid raw materials, lime raw materials, and water and performing a hydrothermal reaction at high temperature and high pressure in an autoclave. This is a molded body obtained by molding and drying the obtained calcium silicate. Reference numeral 2 denotes a radiant heat shielding layer which is interposed between the calcium silicate molded bodies 1A and 1B and between the calcium silicate molded bodies 1B and 1C to form an integral structure. That is, the radiant heat shielding layer 2 is made by uniformly adding about 1 to 30% by weight of fine powder of a metal with high reflectivity (and therefore low emissivity) such as aluminum, copper, brass, or nickel into calcium silicate. The above-mentioned calcium silicate molded body, 1A-1
B, 1B-1C are in close contact with each other to form an integral structure.

Then, the above-mentioned radiant heat shielding layer is closely interposed between the calcium silicate molded bodies, and a molded body having an integral structure is manufactured in the following manner. That is, in the process of producing calcium silicate, silicic acid raw materials (silica powder, etc.)
Radiation of aluminum, copper, brass, nickel, etc. is added to slurry or powder of calcium silicate obtained by mixing lime raw materials (quicklime etc.) and water and hydrothermal reaction under high temperature and pressure in an autoclave. Add a metal with a low percentage of metal in powder form, preferably in an amount equivalent to about 1 to 30% by weight as a fine powder that passes through a 150-mesh sieve, and stir and mix to disperse uniformly. urge At this time, an appropriate amount of an adhesive such as sodium silicate, colloidal silica, colloidal alumina, etc. is dispersed and mixed into the mixture of calcium silicate and metal fine powder to prepare a paste-like substance having an appropriate viscosity. Note that a reinforcing agent such as glass fiber may be mixed if necessary. In addition, when aluminum is used as a metal for radiant heat shielding, the aluminum is corroded by the calcium silicate obtained by the hydrothermal reaction in the autoclave, so using colloidal silica as an adhesive has a corrosion inhibiting effect. In this case, silica colloid may be used.

Next, as shown in the figure, a material 2 in which fine metal powder is uniformly dispersed in sticky calcium silicate paste obtained by the method described above is applied to calcium silicate molded bodies 1A, 1B, and 1C to an appropriate thickness. Calcium silicate molded bodies 1A, 1B,
1C is laminated with paste-like calcium silicate 2 in which fine metal powder is dispersed interposed, and then pressure is applied from the upper and lower surfaces in opposite directions, and this state is maintained and dried using a drying device. As a result, the calcium silicate layer 2 in which the metal fine powder is uniformly dispersed
is manufactured as a laminated heat insulating body 8 in which an integral structure is formed between the calcium silicate molded bodies 1A and 1B, and between the calcium silicate molded bodies 1B and 1C, which are not separated but are tightly adhered to each other. It is to be noted that it is more effective to apply an adhesive curing agent in advance to the calcium silicate molded bodies 1A, 1B, and 1C before applying the paste-like calcium silicate dispersed in metal fine powder to achieve stronger adhesion.

The laminated heat insulating body 3 of the present invention obtained as described above has a dispersed layer of metal fine powder formed within the same structure as the conventional calcium silicate, and therefore has the physical and chemical properties originally possessed by calcium silicate. That is, in addition to sufficiently maintaining the porous structure of continuous open pores, light weight, and heat resistance, it also has the function of blocking radiant heat, which was lacking in conventional calcium silicate, and as a result, the heat insulation performance is further improved. Moreover, unlike the conventional method of interposing metal foil between insulation materials used for radiant heat shielding, a fine metal powder dispersed layer is formed within a single molded body, which is different from the conventional method of interposing metal foil. It is maintained in an extremely strong and stable state without the complexity of work, movement of position, or damage, etc.Therefore, it is particularly suitable for the load placed on the inner and outer tanks when evacuating the space between the inner and outer tanks in a vacuum insulated container. Therefore, it not only has excellent heat insulation performance and strength as a supporting material filled between the inner and outer tanks, but also has many effects such as being extremely easy to turn.

[Brief explanation of drawings]

The drawings are explanatory diagrams of the calcium silicate laminated molded heat insulating body of the present invention, where 1A, 1B, and 1C are calcium silicate molded bodies, and 2 is a calcium silicate layer in which fine metal powder is dispersed.

Claims (1)

[Claims] 1. A calcium silicate laminated insulation body characterized in that a plurality of calcium silicate molded plates are laminated and integrated by interposing a substance made of calcium silicate, metal powder, and adhesive.