JPH04372677A - Heat insulating lining material and heat insulating structure made by using same - Google Patents

Abstract

PURPOSE:To obtain a heat insulating lining material which gives a coating layer excellent in heat insulation, dew prevention, anticorrosiveness, etc., at low cost by incorporating a specified amount of a closed-cell filler into a synthetic resin binder. CONSTITUTION:100 pts.wt. synthetic resin binder comprising a thermoplastic resin (e.g. acrylic resin) or thermosetting resin (e.g. polyurethane) is mixed with 20-300 pts.wt. closed-cell filler (e.g. shirasu baloon) to produce a heat insulating lining material. A coating layer of this material is provided on the surface of a part to be insulated to form a heat insulating structure. Thus, a heat insulating structure which is not adversely affected by rain water or by dewing can be formed. Also, the material can be easily applied to a part to be insulated of complicated structure. A flame retardant, a dispersant, etc., can be incorporated in addition into the material.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to, for example, piping and tanks of plants that are heated, cooled, or kept at constant temperature.
This article relates to a heat insulating lining material used to ensure heat insulation and safety in places that require heat insulation or where temperatures are dangerous if touched directly, and a heat insulating structure using the same. More specifically, the present invention relates to a heat insulating lining material suitable for heat insulation and ensuring safety in places where the surface temperature is relatively close to room temperature even in such places, and a heat insulating structure using the same.

0002

[Prior Art] Conventionally, for example, in plants where insulation is required or where temperature safety is required, perlite or calcium silicate plates or tubes, rock wool blankets, polyurethane foam, polystyrene foam, etc. have been used. The area is covered with heat insulating material, and exterior materials such as colored iron plates are attached to the outside of the heat insulating material.

[0003]Furthermore, in order to ensure safety, metal cages are sometimes installed in areas where heat insulation is not particularly necessary, but where the temperature would be dangerous if directly touched by an operator.

On the other hand, Japanese Patent Publication No. 47-10535 discloses that an epoxy resin and a curing agent contain an inorganic substance containing water of crystallization and S
A heat-insulating material containing an inorganic substance containing iO2 has been proposed, and Japanese Patent Application Laid-open Nos. 118437-1982 and 54-
Japanese Patent No. 126236 proposes a heat insulating paint in which a porous substance such as granular pearlite is mixed with an adhesive.

[0005]

[Problems to be Solved by the Invention] However, the above-mentioned conventional insulation and cage attachment for heat retention and safety have the following problems.

(1) Conventional insulation for heat retention and safety does not provide a completely waterproof structure, and therefore cannot prevent rainwater from entering areas exposed to wind and rain. For this reason, rainwater can enter the gap between the insulated part and the insulation material, and depending on the insulation material, rainwater can penetrate into the insulation material itself.
This not only reduces the heat insulation properties, but also causes corrosion of the heat-insulated part if the surface of the heat-insulated part is made of a material that is easily corroded, such as steel.

[0007] When the surface temperature of the insulated part exceeds 120°C, even if a small amount of rainwater enters, it will evaporate in a short time, so it is possible to prevent corrosion by ordinary rust prevention treatment. be. However, if the surface temperature of the insulated part is 40 to 120 degrees Celsius, especially around 80 degrees Celsius, oxidation is more likely to occur than at room temperature, and the moisture that has entered tends to remain without evaporating in a short period of time, causing corrosion in a short period of time. is easy to progress. This type of corrosion is not visible from the outside, so it is often only noticed after a leakage accident occurs. Periodic inspections are carried out to prevent this, but the insulation must be removed and inspected each time, and once it is confirmed that there are no abnormalities, the insulation must be reinstalled, which is a huge burden on labor and expense. It becomes.

(2) When conventional insulation is applied to a place where the temperature is lower than room temperature, it is difficult to completely prevent condensation on the surface of the insulated part because the surface of the insulated part and the insulating material do not come into perfect contact with each other. Even if the area is not exposed to the wind and rain, this condensation can cause wetting, which can lead to poor insulation and corrosion. Particularly in the case of an insulated part through which a fluid having a temperature lower than room temperature flows, there is a problem that dew condensation occurs on the surface of the insulated part and corrosion is likely to occur.

(3) When trying to ensure safety with a metal cage, it is possible to prevent corrosion with normal rust prevention treatment because it does not particularly accumulate moisture, but in complex piping areas etc. It is difficult to manufacture a cage to match this. Furthermore, not only does it cost about 10 times as much to manufacture as a heat insulating material, but it is also heavy, which limits the locations where it can be installed.

[0010] Furthermore, the method proposed in the above-mentioned gazette is used for parts exposed to extremely high temperatures, such as the nose cone of a rocket, and has the problem of not being able to provide good heat insulation in a temperature range close to room temperature. There is. Furthermore, the method proposed in the above-mentioned publication suffers from limitations such as the need for a large amount of solvent to form a coating layer while maintaining the pores of the added porous material, and the resulting coating layer is There is a problem that water easily enters.

The present invention has been made in view of the above problems, and an object of the present invention is to provide heat insulation at low cost without being affected by the adverse effects of rainwater or dew condensation and without being subject to restrictions on installation locations.

0012

[Means for solving the problem] As a means for this purpose,
The invention of claim 1 provides a heat insulating lining material in which 20 to 300 parts by weight of a filler having closed cells is blended with 100 parts by weight of a synthetic resin binder. Further, in the invention of claim 2, a coating layer of a heat-insulating lining material containing 20 to 300 parts by weight of a filler having closed cells to 100 parts by weight of a synthetic resin binder is provided on the surface of the heat-insulated part. This provides a heat insulating structure with

The synthetic resin binder used in the present lining material may be a thermoplastic resin or a thermosetting resin, and a wide variety of synthetic resins commonly used for paints can be used. Moreover, it is also possible to use a mixture of multiple types of thermoplastic resins or thermosetting resins.

Specific examples of thermoplastic resins include acrylic resin, polyvinyl chloride, polyamide, urethane elastomer, phenoxy resin, vinyl acetate, and ethylene resin.
Examples include polyolefin resins such as vinyl acetate copolymers, and various other rubbery resins.

Specific examples of thermosetting resins include epoxy resins, polyurethanes, polyesters, amino-alkyd resins, amino-acrylic resins, and alkyd resins.

By the way, when a thermoplastic resin is used as the synthetic resin binder, if the temperature of the part to be insulated is high, the coating layer may soften and flow or deform, leading to a decrease in the heat insulation properties. On the other hand, when a thermosetting resin is used as the synthetic resin binder, it can withstand relatively high temperatures, so from this point of view it is preferable to use a thermosetting resin as the synthetic resin binder. In particular, it is preferable to use a halogenated resin for flame retardancy. In addition, when using a thermosetting resin as a synthetic resin binder, it is possible to absorb the internal stress of the coating layer due to the temperature difference between the insulated part side and the outside side. It is preferable to use a curable resin.

The synthetic resin binder may be a mixed resin of a thermoplastic resin and a thermosetting resin. In the case of a mixed resin mainly composed of a thermoplastic resin, plasticization due to heat can be suppressed to some extent by adding a thermosetting resin. In the case of a mixed resin mainly composed of a thermosetting resin, by adding a thermoplastic resin, it can be plasticized to some extent by heat, and flexibility can be imparted to the coating layer. Here, the mixed resin mainly composed of a thermoplastic resin refers to a mixture with a thermosetting resin in which the content of the thermoplastic resin is 51% by weight or more, preferably 70% by weight or more. On the contrary, a mixed resin mainly composed of a thermosetting resin is one in which the content of the thermosetting resin is 51% by weight or more, preferably 70% by weight.
It refers to a mixture with the above thermoplastic resin.

The filler used in the present invention is particularly one having closed cells, such as hollow inorganic beads such as hollow glass beads, hollow beads such as various hollow synthetic resin beads, etc.
Examples include closed-cell multicellular inorganic or synthetic resin granules, and further, multicellular inorganic granules whose surfaces are covered with a film made of glass or the like. Although the particle size of this filler depends on the thickness of the coating layer to be applied, it is preferably 0.1 to 5.0 mm from the viewpoint of adhesion and heat insulation. As commercially available products, "Fuyolite" manufactured by Fuyolite Co., Ltd. and "Shirasu Balloon" manufactured by Shirasu Co., Ltd. can be used.

The blending ratio of the filler having closed cells is 20 to 300 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight (solid content) of the synthetic resin binder. If this proportion is too small, it will be difficult to obtain a sufficient heat insulating effect, and if it is too large, it will be difficult to obtain sufficient adhesion or water will easily penetrate into the coating layer.

The present lining material is applied to the surface of the part to be insulated as a solvent-free type, a solvent-soluble type, an emulsion type, or a water-soluble type.

[0021] The above-mentioned solvent-free type, solvent-soluble type, emulsion type, or water-soluble type may be selected depending on the type of synthetic resin used as the synthetic resin binder. In general, a solvent-soluble type using an organic solvent is easy to use because it is easy to adjust the viscosity so that it is easy to apply even when adding , and there is no need to include moisture that can cause corrosion. However, when synthetic resin beads are used as a filler in a solvent-soluble type using an organic solvent, synthetic resin beads that are insoluble or poorly soluble in the solvent are used.

On the other hand, if a water-based water-soluble or hydrophilic resin is used as a synthetic resin binder to form a water-soluble type using water as a solvent or an emulsion type using water as a dispersion medium, the binder may be, for example, gypsum, cement, or water. A hydraulic or water-soluble inorganic binder such as glass can be used in combination with a synthetic resin binder, thereby improving the heat resistance of the coating layer. When this inorganic binder is used in combination, the amount added is preferably 60 parts by weight or less based on 100 parts by weight of the synthetic resin binder. If the amount added is too large, the coating layer will tend to crack or water will easily penetrate into the coating layer.

[0023] The present lining material may further contain a thickening agent, an anti-sagging agent, a dispersant, a flame retardant, a dye and pigment, and the like. The amount of these additives is preferably 30 parts by weight or less based on 100 parts by weight of the synthetic resin binder.

The thickness of the coating layer of the lining material formed on the surface of the heat-insulated area varies depending on the required heat-insulating performance, but is generally preferably about 2 to 50 mm, more preferably 4 to 50 mm. It is about 5 mm. If the coating layer is too thin, it will be difficult to obtain sufficient heat insulation. From the standpoint of heat insulation, the thicker the better, but if it is too thick, it will be difficult to construct and there will still be economic problems.

The coating layer can be formed by conventional methods such as spraying, pouring, and troweling.

The coating layer may be formed directly on the surface of the heat-insulated part, but in order to improve the adhesion to the surface of the heat-insulated part and the corrosion resistance of the heat-insulated part, it may be formed through a primer layer. You can also. This primer layer can be formed using a commonly used anti-corrosion primer, but a thermosetting resin primer such as epoxy resin or urethane resin is preferred because of its excellent heat resistance.

[0027] In order to improve the weather resistance of the coating layer, an overcoat layer may be provided on the surface of the coating layer. This top coat layer can be formed of, for example, an acrylic resin paint, an acrylic-urethane resin paint, a silicone resin paint, a fluorine resin paint, or the like.

[0028] Examples of parts to be insulated that should be insulated by a coating layer of the present lining material include piping, storage tanks, buildings, and various equipment whose interiors are heated, cooled, or kept at a constant temperature.

In particular, when a thermoplastic resin or a mixed resin mainly composed of a thermoplastic resin is used as the synthetic resin binder, the surface temperature of the heat-insulated portion should be 10° C. or more lower than the softening temperature of the synthetic resin binder, preferably 20° C. or more lower. It is preferable that In addition, when a thermosetting resin or a mixed resin mainly composed of a thermosetting resin is used as a synthetic resin binder, the surface temperature of the insulated part should be 10°C lower than the decomposition temperature of the synthetic resin binder, preferably 20°C or more lower. The temperature is preferably 120°C or lower. If the surface temperature of the insulated part is too high, the coating layer will be easily damaged.

[0030]

[Function] The coating layer of this lining material functions as a heat insulating layer. That is, the blended filler imparts heat insulation properties to the coating layer through the bubbles formed within itself.

[0031] By the way, a certain degree of heat insulation can be obtained even by using a filler that does not have bubbles. Also, even if the filler has open cells, if a large amount of solvent is added,
After application, the bubbles are maintained as the solvent in the filler diffuses, so that the bubbles can provide insulation.

However, in the former case, the insulation obtained is insufficient, and in the latter case, open cells are left in the coating layer, so water easily penetrates into the coating layer, making it impossible to prevent corrosion of the insulated part. . Therefore, in the present invention, a closed cell filling material is used. In the case of this closed-cell filling material, each bubble exists independently within the coating layer, so the presence of air bubbles prevents water from penetrating into the coating layer.
It has high insulation properties due to the air bubbles and can also block moisture infiltration.

[0033]

[Example] Examples 1 to 5, Comparative Examples 1 to 3 Each lining material having the composition shown in Table 1 was applied to a cold rolled steel plate whose surface was spray-coated with an epoxy resin primer and dried to 4 mm.
It was coated thickly with a trowel, dried for 24 hours, and then spray-painted with an acrylic-urethane resin top coat and dried to a constant weight to prepare a test piece. Further, a lining material was applied to the outer peripheral surface to a thickness of 4 mm and dried until a constant weight was obtained, and a glass plate was adhered to one end of the steel tube using a silicone sealing material to form a cylindrical test container.

The test items and test methods conducted using the above test piece and test container are as follows. The results are shown in Table 2.

(1) Heat Insulation Each test piece was placed on a hot plate kept at 90° C. with its coated layer facing up, and the surface temperature of the coated layer side was measured after 1 hour.

(2) Anti-condensation test After 0° C. ice water was placed in a test container and allowed to stand for one hour, the presence or absence of dew condensation on the circumferential surface of the test container was observed. At this time, the temperature in the room was 20°C, and the relative humidity was 73% (dew point: 15°C).

In Table 2, ◯ indicates that no dew condensation was observed, and × indicates that dew condensation was observed.

(3) Adhesive strength Tested in accordance with JIS A6910. That is, 40×
Attach a 40mm steel attachment to the coating surface,
It was pulled using an autograph (manufactured by Shimadzu Corporation, tensile speed: 5 mm/min), and the tensile load at the time of peeling was measured.

(4) Heat/Cool Cycle Test The appearance of each test piece after 10 cycles of heat/cool cycles, with one cycle being 2 hours at 100°C and 2 hours at -10°C, is compared to the appearance before the heat/cool cycle. In addition to comparative observations, the adhesion strength after hot-cooling cycles was measured.

[0040] In Table 2, ○ indicates that no change in appearance was observed at all, and × indicates that a wide range of changes were observed.

(5) Corrosion resistance After spraying salt water for 1000 hours in accordance with JIS K5400 using a salt spray tester specified in JIS Z2371 (however, no cross-cutting was performed), the coating layer was peeled off to determine the presence or absence of corrosion. I looked into it.

In Table 2, ◯ indicates that no corrosion was observed, △ indicates that some corrosion was observed, and × indicates that corrosion was observed over a wide range.

(6) Water permeability The water permeability after 24 hours under 250 mm water pressure was measured in accordance with JIS A6910.

[0044]

[Table 1]

[0045]

[Table 2] As is clear from Table 2, the lining materials of Examples 1 to 5 all substantially satisfy the three properties of heat insulation, anti-condensation properties, and anti-corrosion properties. Furthermore, since the lining material of Example 5 uses thermoplastic resin as a synthetic resin binder, the results of the heat-cooling cycle test are inferior, but it can be used satisfactorily for insulation purposes at lower temperatures than in this test. It is possible. In addition, similar tests were conducted on the lining materials of Examples 1 to 5 by creating test pieces without providing a primer layer and an overcoat layer.
Similar results were obtained.

On the other hand, the lining materials of Comparative Examples 1 to 3 all have problems in their heat insulation properties, dew condensation prevention properties, and corrosion prevention properties. The reason why the lining material of Comparative Example 1 is inferior in heat insulation and anti-condensation properties is because the filler did not have closed cells and no solvent (xylene) was used, so the resin penetrated into the bubbles of the filler and the filling This is thought to be due to insufficient insulation due to the bubbles in the material. The reason why the lining materials of Comparative Examples 2 and 3 are inferior in corrosion resistance is thought to be because they use a filler that does not have closed cells and a large amount of solvent, so although the cells are maintained, water easily penetrates. As a result, water permeability is high.

Comparative Examples 4 and 5 In order to investigate the influence of the water permeability of the coating layers using the lining materials of Comparative Examples 2 and 3, the heat insulation properties were measured using a test method under more natural humid conditions.

[0048] After the test piece that had reached a constant weight was immersed in water for 24 hours and taken out, the test piece was wiped with a cloth and placed on a hot plate maintained at 90°C with the coated side facing up. The surface temperature of the coated layer side was measured after 1 hour.

The results are shown in Table 3 along with the heat insulation properties measured under the dry conditions.

[0050]

[Table 3] In the coating layers of Comparative Examples 2 and 3, water easily penetrates into the bubbles as described above, so the heat insulating effect was significantly reduced in a wet state similar to natural conditions.

[0051]

[Effects of the Invention] The present invention is as described above, and has the following effects.

(1) Since it has excellent heat insulation properties, anti-condensation properties, and anti-corrosion properties, it is possible to maintain heat retention or ensure safety through heat insulation, and at the same time, sufficiently protect the portion to be insulated.

(2) Since only a coating layer is provided, construction can be easily carried out even in a heat-insulated part with a complicated structure.

(3) The coating layer is mainly made of a synthetic resin binder and a filler, and is much lighter and cheaper than conventional metal cages, and is not subject to restrictions on the installation location due to weight.

Claims (2)

[Claims] 1. A heat-insulating lining material characterized in that 20 to 300 parts by weight of a filler having closed cells is blended with 100 parts by weight of a synthetic resin binder. 2. On the surface of the heat-insulated part, 20 parts by weight of a filler having closed cells is added to 100 parts by weight of a synthetic resin binder.
A heat insulating structure characterized by being provided with a coating layer of a heat insulating lining material containing ~300 parts by weight.