JPS59148652A - insulation structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat insulating structure using a powder vacuum heat insulation method.

Structure of conventional examples and their problems Traditionally, insulation materials have been made of inorganic materials such as glass wool, asbestos ceramic foam, and calcium silicate, and foams such as polystyrene, Epoquin, and polyurethane. It is used in various applications from the viewpoints of heat insulation, heat resistance, mechanical strength of 1k, workability, and economical efficiency.

Refrigeration 1. (As the low temperature insulation 41 such as T, polyethylene foam, expanded polystyrene, foam rubber, etc.
Foams such as hard TU polyurethane foam and phenol foam are mainly used, and 0.015-0,
It shows a heat transfer rate of 03711+a1/m h °C, but from the standpoint of energy conservation, it is more important to know that there are 94 rare cases of 1 cedar, 1 nose, and 114 ko that have been affected by thermal effects.

In addition, as the cryogenic insulation used in liquefied nitrogen tanks, foamed perlite powder evacuated to a high vacuum of 0.01 Torr or more is used, or in this case, a container filled with foamed pearlite powder is used. In order to withstand high vacuum, the tubes must be placed in thick iron containers, which is one problem for powder vacuum insulation systems.

A heat insulating structure made by filling a plastic container with a heat insulating material and evacuating it to a vacuum has excellent heat insulating properties with a thermal conductivity of 0.017/mh °C or less, or in general, plastic is superior to metal. The air permeability is high, and the insulation properties deteriorate over time. One way to suppress this air permeation through plastic is to cover the plastic container with foamed resin such as foamed polyurethane, or even in this case, some of the fluorocarbon gas used for foaming (/
i. It has the disadvantage that it enters the plastic container over time and deteriorates the insulation properties of the insulation structure.

Purpose of the Invention The present invention provides an insulating structure that hardly deteriorates over time in a structure formed by filling a plastic container with a heat-retaining insulating material and evacuating it to a vacuum, or by embedding it in a foamed plastic. This is what we provide.

Structure of the Invention The present invention is a heat-insulating structure embedded in foamed plastic, which is a structure formed by filling a plastic container with a heat-insulating material and evacuating it to a vacuum. This is a characteristic heat-insulating structure.

According to the present invention, 0.0121o1/mh at room temperature
It is possible to obtain a heat insulating structure that has an excellent thermal conductivity of 0.degree. C. or less and exhibits almost no deterioration over time.

DESCRIPTION OF EMBODIMENTS FIG. 1 is a diagram for explaining the basic structure of the heat insulating structure of the present invention. A plastic container 2 embedded in a foamed plastic 1 is filled with activated carbon 3, and the inside of the plastic container 2 is evacuated. 1st
The figure is a diagram for explaining the basic configuration of the heat insulating structure.
There is no restriction on the method of filling the activated carbon 3 in the heat insulating structure (C) of the present invention.

As the foamed plastic 1, polyethylene foam,
Expanded follistyrene, phenolic form.

Various types of foam, such as rigid polyurethane foam, have been used depending on the purpose, but as a heat insulating material, (1) it can be foamed on-site. (2) Low thermal conductivity.

(3) Has practical strength. Rigid polyurethane foam is superior in these respects.

The plastic container 2 is made of phenolic resin, urea resin, melamine resin, furan resin, unsaturated polyester resin, epoxy resin, or silicone resin.

Thermosetting resins such as diallyl phthalate resin, vinyl chloride resin, vinylidene chloride resin, polystyrene, AS resin, ABS resin, and methacrylic resin.

Thermoplastic resins such as polyethylene, polypropylene, fluororesin, polyamide, and thermoplastic polyester can be used. From a practical standpoint, polyethylene, polyethylene, polyester.

Film plastic containers such as polypropylene are preferred.

The activated carbon 3 may be activated by either the zinc chloride method or the steam method, but the heat insulating structure of the present invention
In order to exhibit excellent thermal conductivity below 121a-al/mh °C, at least 60 weight percent of the activated carbon 3 must be 16
It is desirable that the activated carbon be able to pass through a Menonyu sieve. Generally, the smaller the particle size of the activated carbon 3, the lower the thermal conductivity of the heat insulating structure of the present invention tends to be.

It goes without saying that substances other than activated carbon may be added to the activated carbon 3 if necessary.

In the insulating structure of the present invention, which is formed by filling a plastic container with activated carbon and evacuating it to vacuum, the structure is embedded in foamed plastic, and the activated carbon in the plastic container is
By adsorbing foaming gas such as fluorocarbon gas that enters the plastic container from inside the foamed plastic,
This is intended to prevent the degree of vacuum within the plastic container from decreasing and the heat insulating properties of the heat insulating structure from deteriorating.

Embodiments of the present invention will be described in detail below.

Examples (1) Activated carbon Y6. Y12. Y24. Y48 (trade name of activated carbon manufactured by Hitachi Carbon Industries) was classified using a sieve to obtain activated carbons A, E, C, and D, each having a particle size distribution of 754.

I got an E. The particle size distribution of each activity 79< is approximately as follows.

Next, the activated carbon A300ji' was filled into a kraft paper bag and dried under vacuum heat at 120°C for 12 hours.Then, the bag was placed in a container made of a laminate film of polyethylene, aluminum thin stone polyvinyl alcohol, and polypropylene. 2 by heating and fusing the opening of the film container under a vacuum of 0.1 Torr using a vacuum packaging machine.
A structure A of 50 mm x 250 mm x 25111111 was obtained. Next, add 300 tnm x 30 to this structure.
Place it in a pressure-resistant container with a space of 0 × 50 rum,
Inject and foam mixed polyurethane foam with Freon-11 (CFCl2) for two nights so that the surface of the structure A is covered with polyurethane foam of approximately the same thickness.
A heat insulating structure A of the present invention was created. Activated carbon B, C, D, E
Similar method for .

The anterior bodies B, C, D, and E were created.

Insulation λ+Vla bodies A, B, C, D, and E are 7 < y, and the thermal conductivity was determined by djlj in the rear chambers 111 and 11. Table 2
showed the value of

The measurement of the proficiency rate is made by DynateCh.
ASTM-C518 using ic heat transfer grammage measuring device
Measured using the method based on (This 11!1.1 heat analysis) One side of the iXli-adhesive field is 35℃, the other side is 1
The temperature was set at 3°C. ) As is clear from Table 2, the heat insulating structure of the present invention, which is formed by filling a plastic container with activated carbon and evacuating it to σf air, is embedded in foamed plastic. It is possible to have a thermal conductivity of /mh °C or less, and its practical value is very large. In addition, regarding the particle size of activated carbon, from Table 2, the present invention'7rfi fjA Ml'i structure or afforestation 012kal
/mh'CJd, in order to exhibit an excellent heat transfer rate of less than 50% by weight of activated carbon, it is desirable that the activated carbon passes through a 16 mesh sieve.

Example (2) Carphorafine-6 (trade name of activated carbon manufactured by Narita Pharmaceutical Industries)
and Shirasagi E-16 (trade name of activated carbon manufactured by Narita Pharmaceutical Industries)
After each was dried at 150° C. for 5 hours in a vacuum heating dryer, the specific surface area of each was measured using a BET method surface area measuring device P-700 (manufactured by Shibata Kagaku Kikai Kogyo). After sufficient degassing, the amount of Freon-11 gas (CFCl2) adsorbed onto the activated carbon at room temperature and in an empty state was measured.

The results are shown in Table 3.

As is clear from Table 3, activated carbon has the ability to sufficiently adsorb fluorocarbons even at room temperature and in a vacuum state.
Insulation of the present invention +・Y) In afforestation, activated carbon adsorbs chlorofluorocarbons that enter the plastic container from inside the foamed plastic, reducing the degree of vacuum inside the plastic container. It has the ability to effectively suppress the deterioration of afforestation insulation properties. In this example, the activated carbon that had been dried at 150° C. for 5 hours in a vacuum heating dryer was used, but the amount of chlorofluorocarbon adsorbed is greatly influenced by this treatment method. For example, in the air 2
The amount of Froncas adsorbed by the activated carbon that was heated and dried at 00°C for 5 hours was about 8 units as shown in Table 3.

Example (3) A heat insulating structure F was obtained in exactly the same manner as in Example (1) except that CarboFine-6 (trade name of activated carbon manufactured by Shikinichi Yakuhin Kogyo) was used as the activated carbon.

Next, this inventive heat insulating structure was heated to 60°C with Freon-11 (
CFCl2) was left in a closed container in a gas atmosphere, and was taken out from time to time to measure its thermal conductivity, and to examine changes in thermal conductivity over time. In addition, as a comparative example, foamed perlite powder (average particle size 3
The heat insulating structure G using .

Figure 2 compares the changes in thermal conductivity over time of the heat insulating structure F (solid line) of the present invention and the heat insulating structure G (dotted line) that does not contain activated carbon at 60°C in a Freon-11 gas atmosphere. .

As is clear from Fig. 2, the heat insulating structure of the present invention can effectively suppress the deterioration of the heat insulating properties caused by a decrease in the degree of vacuum due to the intrusion of fluorocarbon gas into the inside of the foamed plastic and into the plastic container. The practical value is extremely strong.

In this example, Freon-11 gas (CF) is used as the foaming gas.
Although Cl2) was used, any gas can be used as long as activated carbon can adsorb it, and this does not limit the foaming gas to be used in any way.

Effects of the Invention As described above, the present invention is a heat insulating structure in which a plastic container is filled with activated carbon and evacuated to form a structure, which is embedded in foamed plastic.
Its practical value is extremely great, as it has a thermal conductivity of less than mh ℃, is light in weight, has sufficient mechanical strength for practical use, and has almost no deterioration of its insulation properties over time.

[Brief Description of the Drawings] Fig. 1 is a cross-sectional view explaining the basic configuration of the heat insulating structure of the present invention, and Fig. 2 is a heat insulating structure 1 of the present invention.
Foamed plastic, 2...Plastic container, 3.
...Activated carbon. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure B Huan

Claims (4)

[Claims] (1) A heat insulating structure made by filling a plastic container with activated carbon and evacuating the structure, which is then buried in foamed plastic. (2) The heat insulating structure according to claim 1, which is a plastic container or a film-like plastic container. (3) The heat insulating structure according to claim 1, wherein 50% by weight or more of the activated carbon is activated carbon that passes through a 16-menu sieve. (4) The heat insulating structure according to claim 1, which is made of foamed plastic or foamed polyurethane.