JP2016070379A - Adiabatic body and hot water storage tank unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adiabatic body and a hot water storage tank unit showing superior heat resistance characteristic and humidity resistance and producing less amount of carbon dioxide when they are manufactured.SOLUTION: Polyol of at least 70 pts.wt to 50 pts.wt obtained by blending of polyol of 60% or more with functional group of valance of 6 to 8 and polyol of 30% or less with functional group of valance of 3 to 5 is mixed with foam stabilizers, catalysts, water and cyclopentane to make polyol, then plant-origin polyol with functional group of valance of 4 to 5 and viscosity of 1000 to 2500 mPa s is mixed in a range of 30 pts.wt to 50 pts.wt and they are filled in an adiabatic space formed between an outer case and a hot water storage tank. Application of plant-origin polyol enables an adiabatic body having superior heat resistance and humidity resistance required for the hot water storage tank to be attained and enables an amount of carbon dioxide generated when they are manufactured to be substantially reduced.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heat insulator used for a hot water storage tank unit of a hot water storage type water heater, and more particularly to a heat insulator and a hot water storage tank unit filled with polyurethane foam.

  Since the hot water storage type water heater is often provided outdoors, the hot water storage tank unit used for this is provided with a heat insulating material for keeping hot hot water and storing it. In such a hot water storage type hot water heater, for example, as shown in JP 2011-106791 A (Patent Document 1), a molded foam heat insulating material made of polystyrene is arranged around the hot water storage tank to keep the heat. Is going.

  However, since the molded foam heat insulating material has a problem that the adhesiveness with the outer surface of the hot water storage tank is not sufficient and the heat insulating performance is inferior, Japanese Patent Laid-Open No. 58-160758 (Patent Document 2). As shown in the figure, the raw material liquid of the petroleum-based foam heat insulating material such as polyurethane is injected into the heat insulating space between the hot water storage tank and the outer box of the hot water tank unit, and the raw material liquid of the foamable heat insulating material is foamed in the heat insulating space. The filling method is adopted. According to this, since the raw material liquid of the foam heat insulating material enters the narrow gap between the hot water storage tank and the outer box and foams, the adhesiveness between the foam heat insulating material and the hot water storage tank is good, and the heat insulating performance can be improved. It becomes like this.

JP 2011-106791 A JP 58-160758 A

  By the way, since hot water is stored in the hot water storage tank in the hot water storage type water heater, the temperature difference from the outside air temperature becomes large, so that heat leakage tends to increase. Further, as in Patent Document 2, when the heat insulation space between the hot water storage tank and the outer box is filled with the petroleum-based foaming heat insulating material, the foaming heat insulating material is exposed to a high temperature on the hot water storage tank side, and the foaming heat insulating material. The foaming heat insulating material is likely to be deteriorated due to the replacement of the gas existing in the bubbles (foamed cells) and the change in the internal pressure of the bubbles. For this reason, in the hot water storage tank, heat leakage is relatively likely to occur.

  Furthermore, although the hot water storage tank is generally installed outdoors and incorporates waterproofing measures in terms of design, the foaming heat insulating material swells due to the ingress of moisture from the outside and the increase in humidity based on this, The thermal conductivity may deteriorate over time. In addition, since it is exposed to direct sunlight in the summer, the ambient temperature of the hot water storage tank unit also rises, so that the gas present in the foam (foaming cell) of the foaming insulation material is replaced and the internal pressure of the foam changes, causing foaming. The heat insulating material tends to deteriorate. Thus, in the hot water storage tank, heat leakage is relatively likely to occur, and it is difficult to ensure the temporal stability of the heat insulating performance of the foamable heat insulating material. Thus, it is an important specification that the foamable heat insulating material used in the hot water storage unit of the hot water storage type water heater has heat resistance and moisture resistance.

  On the other hand, as a social effort to prevent global warming, measures are being taken in various fields in order to control carbon dioxide (CO2) emissions. And it is important to suppress the generation amount of carbon dioxide until the manufacturing process of a heat insulating material as a countermeasure against global warming. For example, polyether polyol, which is one of the constituent raw materials for petroleum-based foam heat insulating materials, is a raw material derived from petroleum, and the amount of carbon dioxide generated during production is large.

  An object of the present invention is to provide a heat insulator and a hot water storage tank unit that are excellent in heat resistance and moisture resistance and that generate less carbon dioxide during production.

  The feature of the present invention is that at least 70% by weight to 50% by weight of a polyol obtained by blending 60% or more of a polyol having 6 to 8 functional groups and 30% or less of a polyol having 3 to 5 functional groups. A polyol prepared by mixing a foam stabilizer, a catalyst, water and cyclopentane in a part, and 30 to 50 parts by weight of a plant-derived polyol having a functional group number of 4 to 5 and a viscosity of 1000 to 2500 mPa · s. It is mixed in the range, and this is filled and foamed in the heat insulation space formed between the outer box and the hot water storage tank.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in the heat resistance and moisture resistance of a heat insulating body and a hot water storage tank unit, the generation amount of the carbon dioxide at the time of manufacture can be reduced significantly.

It is a figure which shows the hot water storage tank unit which concerns on one Embodiment of this invention, and is a front view of a hot water storage tank unit. It is a figure which shows the hot water storage tank unit concerning one Embodiment of this invention, and is a right view of a hot water storage tank unit. It is sectional drawing which shows the XX cross section of FIG. 1B. It is sectional drawing which shows the YY cross section of FIG. 1A. It is sectional drawing which shows the ZZ cross section of FIG. 1A. It is a disassembled perspective view of a hot water storage tank unit. It is a figure which shows the position which extract | collects a foaming heat insulating material from a hot water storage tank. It is a figure which shows the physical property of the polyurethane foam produced by the Example of this invention compared with a prior art example and a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range.

  Before describing an embodiment of the present invention, a configuration of a hot water storage type hot water heater will be briefly described with reference to FIGS. 1A to 1E and FIG. The hot water storage tank unit TU is a device that constitutes a heat pump water heater, and includes a hot water storage tank 1 and an exterior body that covers the hot water storage tank 1. The hot water storage tank 1 is a container for storing hot water and the like, and has a hollow, substantially cylindrical shape. On the other hand, the exterior body includes exterior plates 2, 3 and 4, a partition plate 5, a joint mounting plate 6, top plate auxiliary plates 7 and 8, a top plate 9 and a bottom plate 10.

  The exterior plates 2 and 3, the partition plate 5, the top plate auxiliary plates 7 and 8, and the bottom plate 10 constituting a part of these exterior bodies constitute an outer box of the heat insulation box 15 that houses the hot water storage tank 1. Yes. As described above, the heat insulating box 15 shown in the figure is configured with the exterior plates 2 and 3, the partition plate 5, the top plate auxiliary plates 7 and 8, and the bottom plate 10 as an outer box and the hot water storage tank 1 as an inner box. ing. A vacuum heat insulating material containing a decompressed core material is attached to the inner side surface of the outer box with an adhesive tape or hot melt.

  Inside the hot water storage tank unit TU, as shown in FIGS. 1C and 1D, the hot water storage tank 1 is supported by an inner leg 11 fixed to the upper surface of the bottom plate 10 and accommodated inside the outer box. A heat insulating space 14 is formed between the hot water storage tank 1 and the outer box, and the heat insulating space 14 is filled with a foamable heat insulating material 16 formed of polyurethane foam. A specific constituent material of the foamable heat insulating material 16 is a feature of the present invention, which will be described in detail below with reference to FIG.

  On the other hand, inside the hot water storage tank unit TU, on the front side of the partition plate 5, the exterior plate 4, the partition plate 5 and the top plate auxiliary plate 7 are used as side walls, the top plate 9 is used as the top wall, and the joint mounting plate 6 is used as the bottom wall. A machine room 13 is formed. The machine room 13 accommodates instrumentation equipment (not shown) such as pipes, valves provided in the pipes, pumps, electrical components, control equipment, sensors, and the like. The hot water storage tank unit TU in which the heat insulating space 14 and the machine room 13 are formed is supported and installed by the outer legs 12 fixed to the lower surface of the bottom plate 10.

  A plurality of pipes (not shown) are connected to the hot water storage tank 1 at the bottom surface (bottom wall) and the top surface (top wall). A water supply pipe is connected to the bottom surface of the hot water storage tank 1, and water supplied from a water supply source is supplied to the hot water storage tank 1 through the water supply pipe. In addition, a hot water supply pipe and a water intake pipe are respectively connected to the bottom surface part and the top surface part, and a heat exchanger is connected to the other end of these pipes. An annular pipe line is formed.

  In the heat pump water heater provided with the hot water storage tank unit TU, the heat exchanger is stored in the hot water storage tank 1 by exchanging heat by a heat pump cycle including a compressor, a condenser, an expansion valve, an evaporator, and the like. Heats hot water. The stored hot water is supplied from the top surface portion of the hot water storage tank 1 to the heat exchanger via the incoming water piping, and the heated hot water is returned to the bottom surface portion of the hot water storage tank 1 via the hot water supply piping. In addition, a hot water supply pipe is connected to the top surface, and hot water (90 ° C. to 100 ° C.) stored in the hot water storage tank 1 is supplied through the hot water supply pipe and used by residents of the residential building.

  As shown in FIG. 1E, the heat insulating space 14 of the heat insulating box 15 is filled with a raw material for forming the foamable heat insulating material 16 from the foam heat insulating material inlet 18. By filling the foamable heat insulating material 16, a heat insulating layer is formed over the entire outer peripheral surface, upper surface and lower surface of the hot water storage tank 1 to reduce heat leakage. In addition, the vacuum heat insulating material is pressed against the inner surface of the outer box by the foaming pressure of the foamable heat insulating material 16 and the hardening after foaming, and the vacuum heat insulating material is peeled off or there is a gap between the outer box and the vacuum heat insulating material. Is prevented. By doing in this way, it becomes the structure by which the effect | action which vibration resistance is further improved and vibration resistance is improved by fixing between each member firmly is obtained. Polyurethane is generally used as the conventional petroleum-based foam heat insulating material 16, and liquid polyurethane is injected into the heat insulating space 14 together with a foaming agent and isocyanate, and solidified while foaming to form a heat insulating layer. It is.

  By the way, since the hot water storage tank unit is often installed outdoors, the minute size of the mutual fitting portion of the exterior plate 2, the exterior plate 3, the top plate auxiliary plate 8, and the bottom plate 10 forming the outer box shown in FIG. There is a risk of moisture or moisture entering through the gap. When moisture or moisture enters, it gradually begins to enter the foamed cell from the skin layer, and eventually the cell swells and collapses, and the foam shrinkage becomes remarkable. In addition, the thermal conductivity and mechanical properties are greatly deteriorated, which may lead to deterioration of the amount of heat leakage. Furthermore, petroleum-based foam heat insulating materials generate a large amount of carbon dioxide during the production process, and it is necessary to reduce the amount used as much as possible against global warming.

  From this point of view, this embodiment proposes a heat insulating material that is excellent in heat resistance and moisture resistance as a heat insulating material for a hot water storage tank and that generates less carbon dioxide during production. First, the composition of the polyurethane foam raw material filled in the heat insulation space 14 between the exterior pair (outer box) and the hot water storage tank (inner box) constituting the heat insulation box will be described.

  The premix polyol as the foamable heat insulating material 16 according to the present example is a premix polyol composition containing a polyol, a foam stabilizer, a catalyst, water and cyclopentane, and one kind of polyhydric alcohol having 3 to 8 functional groups. Alternatively, a compound obtained by adding an alkylene oxide to a mixture of two or more kinds is used as the base of the polyol.

  Here, among polyhydric alcohols having 3 to 8 functional groups, examples of polyhydric alcohols having 6 to 8 functional groups include sugars such as sucrose and lactose, derivatives thereof, and phenols. Examples of the polyhydric alcohol having 3 to 5 functional groups include diglycerin, pentaerythritol, methyl glucoside, ethylenediamine, toluenediamine, diphenylmethanediamine, and tetramethylolcyclohexane. These may be used alone or in combination of two or more. Preferred are 6 to 8 functional group sucrose and 3 to 5 functional group toluenediamine.

  Further, as the catalyst used in this example, a known foaming catalyst, resinification catalyst, and trimerization catalyst are used. Pentamethyldiethylenetriamine, dimethylcyclohexylamine, bis (dimethylaminoethyl) ether, N, N, N′— Trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol, diethylcyclohexylamine, triethylenediamine, N, N, N ', N'-tetramethylhexanediamine, N, N, N', N'-tetramethylpropylene Diamine, N, N, N ′, N′-tetramethylethylenediamine, N, N ′, N ″ -tris (3-dimethylaminopropyl) hexahydro-s-triazine, N, N ′, N ″ -tris ( 3-diethylaminopropyl) hexahydro-s-triazine and the like can be used.

  Furthermore, the polyisocyanate used in this example may be a known one, and is not particularly limited. For example, there are diphenylmethane diisocyanate (MDI) and its derivatives. These may be used alone or mixed. Can be used. In addition, there are tolylene diisocyanate (TDI) and derivatives thereof, and examples thereof include a mixture of 2,4-TDI and 2,6-TDI, a terminal isocyanate prepolymer derivative of TDI, and the like. Examples of MDI and its derivatives include a mixture of MDI and its polymer polyphenylpolymethylene diisocyanate, and a diphenylmethane diisocyanate derivative having a terminal isocyanate group.

  In this embodiment, a plant-derived polyol is used as an auxiliary polyol. The plant-derived polyol specifically has 4 to 5 functional groups and a viscosity of 1000 to 2500 mPa · S. Examples of the plant-derived polyol include plant-derived polyols such as soybean, oil palm, rapeseed, coconut, cottonseed, sunflower, here, castor oil, etc. These may be used alone or in combination of two or more. It can be used. Since the plant-derived polyol has a low number of functional groups and a low viscosity, it has excellent heat resistance and moisture resistance, and can suppress the amount of carbon dioxide generated during production.

  By the way, according to the knowledge of the present inventors, it has been found that there is a difference in the hardness, weight change rate, and thermal conductivity of the polyurethane foam depending on the mixing ratio of the plant-derived polyol, and there is a preferable mixing ratio in the heat insulating material of the hot water storage tank. did. That is, since the hot water storage tank unit is often installed outdoors, there is a risk that moisture and moisture may enter through the gaps in the outer box. When moisture or moisture has infiltrated, it gradually begins to enter the foamed cell from the skin layer, and finally the cell swells and collapses, and the foam shrinkage becomes remarkable. In addition, the thermal conductivity and mechanical properties are greatly deteriorated, which may lead to deterioration of the amount of heat leakage.

  Therefore, since it is necessary to obtain a suitable mixing ratio that can withstand these events, the present inventors, as shown in FIG. 4, have a conventional heat insulation box, a plurality of heat insulation boxes according to this embodiment, and a comparison. We made a heat insulation box for and searched and investigated its physical properties. As shown in FIG. 3, the mechanical properties and thermal conductivity were evaluated by measuring polyurethane foam sample 21 cut out in an area of 200 × 200 mm at a position 500 mm away from the polyurethane foam raw material inlet 18, 22 was used.

  The foam hardness ratio shown in FIG. 4 is a comparison of measured values when a hardness tester is pressed from the top for a measurement sample when left for 21 days in an environment of a temperature of 90 ° C. and a relative humidity of 100%. doing. And it represents with the ratio when the hardness of the polyurethane foam created with the conventional structural material is set to 100% of a parameter | index. Moreover, the weight change rate shown in FIG. 4 compares the weight change amount in the test environment mentioned above. Furthermore, the thermal conductivity shown in FIG. 4 is measured and compared with the thermal conductivity in the test environment described above, and the thermal conductivity was measured with an HC-073 type manufactured by Eihiro Seiki. It is expressed as a ratio when the thermal conductivity of a polyurethane foam made of a conventional constituent material is taken as an index of 100%.

  Hereinafter, based on FIG. 4, the comparison result of the heat insulation box which becomes a present Example, the conventional heat insulation box, and the heat insulation box for a comparison is demonstrated.

<Conventional example>
As a conventional polyurethane foam raw material, 100 parts by weight of a 6-functional polyhydric polyol component mixed with 70% sucrose-based polyol and 30% toluenediamine is used. 1.0 part was used to prepare a premix polyol using water and cyclopentane as a foaming agent and organic silicone as a foam stabilizer. Furthermore, polymethylene polyphenyl diisocyanate was used as an isocyanate component, and the heat insulating space between the outer body (outer box) and the hot water tank (inner box) of the hot water tank unit was filled and foamed.

  In the foaming process of the heat insulating material of the hot water storage tank, first, an outer box made of a steel plate and an inner box made of a resin molded product are combined, and a hot water storage tank having a heat insulating space formed by these combinations is manufactured and temperature-controlled in advance. Thereafter, as shown in FIG. 3, the hot water storage unit was set in a pre-temperature-controlled foaming jig so that the front side of the hot water storage unit was on the lower side and the rear side was on the upper side, and a prescribed amount of polyurethane foam raw material (polyol mixture and Water, cyclopentane, catalyst, mixed composition premixed with foam stabilizer and isocyanate) are injected into the adiabatic space. At the time of injection, a polyol and isocyanate, which are polyurethane raw materials, are collided and mixed in an injection head to promote a chemical reaction and pressurized by foaming pressure, and polyurethane foam is filled into a heat insulating space of a hot water storage tank to be completed.

  The completed hot water storage tank unit is dismantled and the polyurethane foam at the position shown in FIG. 3 is cut out and the foam hardness and weight change of the sample when left in an environment of 90 ° C. and 100% relative humidity for 21 days. Rate and heat transfer rate are measured. Regarding foam hardness and thermal conductivity, the following examples and comparative examples are evaluated based on this conventional example as a standard (index: 100%). Moreover, the change of 3.5% of weight change rate is recognized, and a direction with little change rate has a high evaluation as a heat insulating material.

<Example 1>
Example 1 includes 70 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluenediamine are mixed, and 30 weight of castor oil polyol A having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 20% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, the foam hardness ratio became 118%, the weight change rate became 0.6%, and the heat conductivity ratio became 75%. Therefore, it can be understood that the heat resistance and the moisture resistance are greatly improved as compared with the conventional example.

<Example 2>
Example 2 includes 65 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluenediamine are mixed, and 35 weight of castor oil polyol B having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 25% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 119%, weight change rate became 0.5%, and thermal conductivity ratio became 78%. Therefore, it can be understood that the heat resistance and moisture resistance of the present example are greatly improved as compared with the conventional example.

<Example 3>
Example 3 includes 65 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluenediamine are mixed, and 35% of castor oil polyol B having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 15% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 119%, weight change rate became 0.5%, and thermal conductivity ratio became 80%. Therefore, it can be understood that the heat resistance and moisture resistance of the present example are greatly improved as compared with the conventional example.

<Example 4>
Example 4 includes 60 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluenediamine are mixed, and 40% of castor oil polyol B having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 15% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 120%, weight change rate became 0.4%, and thermal conductivity ratio became 82%. Therefore, it can be understood that the heat resistance and moisture resistance of the present example are greatly improved as compared with the conventional example.

<Example 5>
Example 5 includes 45 parts by weight of a polyol component in which 70% of shoe-closed polyol and 30% of toluenediamine are mixed, and 45% of castor oil polyol B having a viscosity of 1000 to 2500 mPa · S and a degree of biomass of 30% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 120%, weight change rate became 0.4%, and thermal conductivity ratio became 84%. Therefore, it can be understood that the heat resistance and moisture resistance of the present example are greatly improved as compared with the conventional example.

<Example 6>
Example 6 is 50 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluene diamine are mixed, and 50% of castor oil polyol B having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 35% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 121%, weight change rate became 0.3%, and thermal conductivity ratio became 85%. Therefore, it can be understood that the heat resistance and moisture resistance of the present example are greatly improved as compared with the conventional example.

<Comparative Example 1>
Comparative Example 1 includes 75 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluenediamine are mixed, and 25 weight of castor oil polyol A having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 20% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, foam hardness ratio became 95%, weight change rate became 1.8%, and thermal conductivity ratio became 97%. Therefore, in Comparative Example 1, the foam hardness was greatly inferior. This is presumably because the foam hardness is inferior because the mixing ratio of the plant-derived polyol is small.

<Comparative Example 2>
Comparative Example 2 is 45 parts by weight of a polyol component in which 70% of a shoe-closed polyol and 30% of toluene diamine are mixed, and 55 weight of castor oil polyol A having a viscosity of 1000 to 2500 mPa · S and a biomass degree of 20% as a plant-derived polyol. A premix polyol was prepared by using 2.0 parts of an amine catalyst and 1.0 part of a trimerization catalyst as reaction catalysts, water and cyclopentane as foaming agents, and organic silicone as a foam stabilizer. . In addition, polymethylene polyphenyl diisocyanate is used as the isocyanate component and the heat insulation space between the outer body (outer box) of the hot water tank unit and the hot water tank (inner box) is filled and foamed under the condition of a blending ratio of 0.90. A heat insulating material was produced. And as a result of measuring each physical property on the same conditions as a prior art example, the foam hardness ratio became 105%, the weight change rate became 0.3%, and the heat conductivity ratio became 105%. Therefore, in Comparative Example 2, the thermal conductivity was greatly inferior. This is presumed that the mixing ratio of the plant-derived polyol is too high, resulting in poor thermal conductivity.

  As can be seen from each of the above-mentioned examples, the foam hardness, weight change rate, heat conduction with respect to temperature and humidity can be supplemented by mixing plant-derived polyol in the range of 30 to 50 parts by weight. The rate can be improved from the conventional one. In addition, although castor oil was used as the plant-derived polyol described above, various plant-derived polyols can be used without being limited thereto. However, it is desirable to use castor oil from the viewpoint of easy procurement, heat resistance, and moisture resistance.

  As described above, according to the present invention, at least a polyol 70 obtained by blending 60% or more of a polyol having 6 to 8 functional groups and 30% or less of a polyol having 3 to 5 functional groups. A polyol prepared by mixing a foam stabilizer, a catalyst, water and cyclopentane in 50 to 50 parts by weight, and 30 parts by weight of a plant-derived polyol having 4 to 5 functional groups and a viscosity of 1000 to 2500 mPa · s. It mixed in the range of -50 weight part, and this was filled into the heat insulation space formed between the outer box and the hot water storage tank. According to this, heat insulation and heat resistance necessary for hot water storage tanks can be obtained by adopting plant-derived polyols, and a heat insulating material for hot water storage tanks that can greatly reduce the amount of carbon dioxide generated during production can be obtained. It is.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Hot water storage tank, 2 ... Exterior plate, 3 ... Exterior plate, 8 ... Top plate auxiliary plate, 10 ... Bottom plate, 11 ... Inner leg, 12 ... Outer leg, 14 ... Thermal insulation space, 15 ... Hot water storage tank unit, 16 ... Foaming Heat insulating material.

Claims (5)

In a heat insulator including a foamable heat insulating material,
The foamable heat insulating material is obtained by blending at least 60% of a polyol having 6 to 8 functional groups and 30% or less of a polyol having 3 to 5 functional groups in an amount of 50 to 50 parts by weight. A polyol prepared by mixing a foam stabilizer, a catalyst, water and cyclopentane in parts by weight, and 30 to 50 parts by weight of a plant-derived polyol having 4 to 5 functional groups and a viscosity of 1000 to 2500 mPa · s. A heat insulator characterized by being mixed and foamed within the range. The thermal insulator according to claim 1,
A thermal insulation having a biomass degree of the plant-derived polyol of 15% to 35%. The thermal insulator according to claim 1,
The heat insulating body, wherein the polyol having 6 to 8 functional groups is a shoe-closed polyol, and the polyol having 3 to 5 functional groups is toluenediamine. In the heat insulator according to any one of claims 1 to 3,
The plant-derived polyol is castor oil. In the hot water storage tank unit, which is composed of a hot water storage tank and an exterior body, and is filled with a foaming heat insulating material and foamed into a heat insulating space formed by the hot water storage tank and the exterior body,
The foamable heat insulating material is obtained by blending at least 60% of a polyol having 6 to 8 functional groups and 30% or less of a polyol having 3 to 5 functional groups in an amount of 50 to 50 parts by weight. A polyol prepared by mixing a foam stabilizer, a catalyst, water and cyclopentane in parts by weight, and 30 to 50 parts by weight of a plant-derived polyol having 4 to 5 functional groups and a viscosity of 1000 to 2500 mPa · s. A hot water storage tank unit formed by mixing in the range of the above, filling the heat insulation space and foaming.

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