Abstract: A vacuum heat insulator according to the present invention includes a core molded to be plate-shaped with the use of a binding agent. The vacuum heat insulator assumes any one of the following configurations. A) The core is formed by curing a fiber aggregate by means of a binding agent. The fibers have an average fiber diameter of at least 0.1 ?m but at most 10 ?m, and voids defined by fibers have a void diameter of at most 40 ?m. The core has a percentage of the voids of at least 80%. B) The binding agent is varied in concentration in a through-thickness direction of the core. C) A cured layer solidified by the binding agent is formed on at least one side surface of the core. D) The core contains fibers having a length of at most 100 ?m. The fibers are oriented perpendicular to a direction of heat transmission. Such vacuum heat insulator is excellent in adiabatic property.

Abstract: In a vacuum heat insulator, a heat seal layer of its enveloping member of a laminated structure is made of a film having a melting point of at least 200° C. Alternatively, the heat seal layer is made of a film having a melting point above 100° C. and below 200° C., and fins are bent on a low-temperature side. Either of these structures can inhibit a decrease in gas barrier property even in a high-temperature atmosphere of approx. 150° C. Thus, the heat-insulating property of the vacuum heat insulator is maintained for a long period of time. This vacuum heat insulator is preferable for an apparatus that has a heat source or a portion to be kept warm exceeding a temperature of 100° C.

Abstract: In a vacuum heat insulator, a heat seal layer of its enveloping member of a laminated structure is made of a film having a melting point of at least 200° C. Alternatively, the heat seal layer is made of a film having a melting point above 100° C. and below 200° C., and fins are bent on a low-temperature side. Either of these structures can inhibit a decrease in gas barrier property even in a high-temperature atmosphere of approx. 150° C. Thus, the heat-insulating property of the vacuum heat insulator is maintained for a long period of time. This vacuum heat insulator is preferable for an apparatus that has a heat source or a portion to be kept warm exceeding a temperature of 100° C.

Abstract: A vacuum heat insulator according to the present invention includes a core molded to be plate-shaped with the use of a binding agent. The vacuum heat insulator assumes any one of the following configurations. A) The core is formed by curing a fiber aggregate by means of a binding agent. The fibers have an average fiber diameter of at least 0.1 ?m but at most 10 ?m, and voids defined by fibers have a void diameter of at most 40 ?m. The core has a percentage of the voids of at least 80%. B) The binding agent is varied in concentration in a through-thickness direction of the core. C) A cured layer solidified by the binding agent is formed on at least one side surface of the core. D) The core contains fibers having a length of at most 100 ?m. The fibers are oriented perpendicular to a direction of heat transmission. Such vacuum heat insulator is excellent in adiabatic property.