JP2021032339A - Heat insulating board - Google Patents

Abstract

To provide a heat insulating board that uses strong rigid polyurethane foam, is excellent in heat insulation performance and can insulate a curved portion.SOLUTION: The present invention is a bendable heat insulating board which is made of rigid polyurethane foam as a core material and on both sides of which face materials are laminated, wherein, the specific tensile strength of the face material measured in accordance with JIS P 8113 is 5.0 Nm/g or more and 13.0 Nm/g or less in the length direction and width direction of the core material.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bendable heat insulating board suitable for heat insulating a curved surface portion.

Insulation materials are used to keep warm and cool in various fields.
For example, a flexible heat insulating sheet is used for heat insulating an object having a curved surface such as a cylindrical container such as a drum or a tank or a concrete structure having a curved surface.
As a flexible heat insulating sheet, a synthetic resin foam such as flexible polyurethane foam or polyethylene foam is processed into a plate or sheet, or a fiber such as glass fiber is compressed and molded into a plate or sheet. Things are being used.

However, the heat insulating performance of flexible foam sheets such as flexible polyurethane foam and polyethylene foam is not high. Further, if the thickness of the sheet is increased, the heat insulating performance is improved, but if it is too thick, the flexibility is inferior and it becomes impossible to follow the curved surface portion. Moreover, since flexible polyurethane foam easily absorbs water, it is not suitable for outdoor use.

On the other hand, hard polyurethane foam is a synthetic resin foam that is inferior in flexibility, although it is used as a heat insulating material for buildings because it has excellent heat insulating performance and is hard and strong. Therefore, if a rigid polyurethane foam processed into a plate shape is used and bent to follow a curved surface portion, there is a risk of cracking. Further, if the thickness of the board is reduced, it may be bent, but the heat insulating performance is deteriorated.
Even if the board is thick, it is possible to follow the curved surface shape by forcibly bending it by applying strong pressure at the factory, but performance is likely to deteriorate and transportation to the construction site is taken into consideration. , Bent boards cannot be stacked flat, and large quantities cannot be loaded, resulting in poor transportation efficiency.

Therefore, as a method of insulating the curved surface portion, a method of arranging and covering a plurality of heat insulating materials processed into tiles or strips on the curved surface portion (Patent Document 1), or a heat insulating mold in which a face material is laminated on the surface of the foam. A method is known in which a panel is curved by providing a plurality of grooves on a surface that bends inward (Patent Document 2).
However, in the methods of Patent Documents 1 and 2, the number of steps is large and a large amount of labor is required, and the degree of adhesion to the curved surface is often insufficient, resulting in inferior heat insulating performance.

Further, in the case of a large structure, it is known to use a urethane spraying method by in-situ foaming. With this method, it is easy to perform heat insulation work according to the curved surface part, but it is difficult to obtain the desired heat insulation performance because the thickness accuracy is difficult to obtain as compared with products produced in factories such as boards. In addition, since the construction is carried out by a specialized contractor using special equipment, the construction will be large-scale.

Japanese Unexamined Patent Publication No. 59-20828 Japanese Unexamined Patent Publication No. 4-258466

As described above, it has been difficult to insulate a curved surface portion by using a rigid polyurethane foam having excellent heat insulating performance and strength.

Therefore, an object of the present invention is to provide a heat insulating board which uses a strong rigid polyurethane foam, has excellent heat insulating performance, and can insulate a curved surface portion.

As a result of studies to solve the above problems, it was found that a bendable heat insulating board can be obtained by combining a rigid polyurethane foam with a specific face material.

That is, the present invention is a bendable heat insulating board in which a rigid polyurethane foam is used as a core material and face materials are laminated on both sides thereof, and the specific tensile strength measured in accordance with JIS P 8113 of the face material. The core material is 5.0 Nm / g or more and 13.0 Nm / g or less in the length direction and the width direction.

Although it is difficult to bend the rigid polyurethane foam alone, the heat insulating board of the present invention is made of rigid polyurethane because face materials having specific specific tensile strengths are laminated on both sides in the length direction and the width direction of the core material. It can be easily bent while maintaining the strength of the foam. Therefore, the heat insulating board of the present invention can be used as a heat insulating material for an object having a curved surface portion.

Further, the face material of the present invention preferably has a tensile elongation at break measured in accordance with JIS P 8113 of 25% or more and 35% or less in the length direction and the width direction of the core material.

Since the face material has a specific specific tensile strength and a specific tensile elongation at break in the length direction and the width direction of the core material, the force required when bending the heat insulating board can be suppressed and the bending can be made easier. ..

Further, it is preferable that the thickness of the core material made of the rigid polyurethane foam of the present invention is 5 mm or more and 50 mm or less.

The thicker the core material, the better the heat insulating performance, but if it is too thick, it becomes difficult to bend even if the face material of the present invention is used. In the present invention, by setting the thickness of the core material to 5 mm or more and 50 mm or less, it is possible to obtain a heat insulating board having excellent heat insulating performance and being easy to bend.

The thermal conductivity of the heat insulating board of the present invention is 0.024 W / (m · K) or less. The thermal conductivity is a value measured in accordance with JIS A 9511.

Here, the thermal conductivity is a value indicating the ease of heat transfer of a substance, and the smaller the value, the more difficult it is for heat to be transferred. The thermal conductivity of the heat insulating board depends on the heat insulating performance of the rigid polyurethane foam as the core material. That is, by using a core material having high heat insulating performance, the heat insulating performance of the heat insulating board is also improved. In the present invention, the heat insulating board having excellent heat insulating performance has a thermal conductivity of 0.024 W / (m · K) or less.

In the heat insulating board of the present invention, a face material having excellent heat insulating performance by using a rigid polyurethane foam as a core material and having a specific specific tensile strength in the length direction and the width direction of the core material is provided on both sides of the core material. Since it is laminated, it can be easily bent while maintaining the strength of the rigid polyurethane foam. Therefore, it is possible to provide a heat insulating board capable of heat insulating a curved surface portion.

It is sectional drawing explaining the heat insulation board of this invention. It is a figure explaining the bending radius of the heat insulating board of this invention. It is a figure explaining the state which wound this invention around a cylindrical container.

As shown in FIG. 1, the present invention is a heat insulating board 1 in which a rigid polyurethane foam is used as a core material 2 and face materials 3 and 3 are laminated on both sides thereof.

The core material 2 of the present invention is made of a rigid polyurethane foam, and is a foam obtained by mixing and reacting, for example, a polyisocyanate, a polyol made of a polyether polyol or a polyester polyol, a foaming agent, and a foam stabilizer. Further, if necessary, various additives generally used in the production of rigid polyurethane foams such as catalysts and flame retardants may be added.

As the polyol used for the rigid polyurethane foam used in the present invention, a polyester polyol or a polyether polyol can be preferably used, and one of these can be used alone or two or more thereof can be used in combination.

Examples of the polyester polyol include a polyol obtained by condensing a polyhydric alcohol with a multivalent carboxylic acid and a polyol composed of cyclic ester ring-opening polymerization. Examples of the polyvalent carboxylic acid include polyols composed of succinic acid, glutonic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid and anhydrides thereof. On the other hand, examples of the polyhydric alcohol include ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, shoeclaw, and bisphenol A. Among them, as the polyester polyol, a polyester polyol having an aromatic ring is particularly preferable.
The hydroxyl value of the polyester polyol is not particularly limited, but is preferably 100 to 400 mgKOH / g.

Examples of the polyether polyol include alcohols such as aliphatic alcohols, aromatic alcohols and the above polyhydric alcohols; aliphatic amines such as ethanolamine, diethanolamine, triethanolamine and ethylenediamine; aromatics such as toluenediamine and methylenedianiline. Group amines: Polyether polyols obtained by addition-polymerizing one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to Mannig condensate and the like can be mentioned, and these polyether polyols are 1 The seeds can be used alone or in combination of two or more as appropriate.
Among them, as the polyether polyol, an aromatic polyether polyol is particularly preferable because it lowers the thermal conductivity.
The hydroxyl value of the polyether polyol is not particularly limited, but is preferably 300 to 800 mgKOH / g.
Further, a polymer polyol in which a polymer component such as vinyl acetate, polyacrylonitrile, or polyacrylonitrile / styrene copolymer is dispersed in a polyether polyol may be used. In particular, a polymer polyol in which vinyl acetate or a polyacrylonitrile / styrene copolymer is dispersed in a polyether polyol is preferably used.

Examples of the polyisocyanate to be reacted with the above-mentioned polyol include diphenylmethane diisocyanate (MDI) and polyether diphenylmethane diisocyanate (polymeric MDI); these modified polyisocyanates, that is, products obtained by a partial chemical reaction of the polyisocyanate, for example, Polyisocyanates containing groups such as esters, ureas, burettes, allophanates, carbodiimides, isocyanurates and urethanes; and the like. One of these polyisocyanates may be used alone, or two or more thereof may be used in combination as appropriate.

The amount of the above-mentioned polyisocyanate used is preferably such that the isocyanate index represented by the following formula (1) is 30 to 300, and more preferably 80 to 150.
Isocyanate index = active hydrogen of NCO group / polyol × 100 (1)

As the foaming agent used for the rigid polyurethane foam used in the present invention, at least one selected from water, HFC, HC, HFO, and carbon dioxide can be used. Examples of HFCs include 1,1,1,3,3-pentafluoropropane (HFC245fa), 1,1,1,3,3-pentafluorobutane (HFC365mfc) and the like. Examples of HC include normal pentane, isopentane, cyclopentane, isobutane and the like. The HFOs include tetrafluoropropene (HFO1234), trifluoropropene (HFO1243), 1-chloro-3,3,3-trifluoropropene (HFO1233), and tetrafluorobutene (2,4,5,4-tetrafluoro). Examples thereof include HFO1354) other than butene-1, pentafluorobutene (HFO1345), hexafluorobutene (HFO1336), heptafluorobutene (HFO1327), heptafluoropentene (HFO1447), octafluoropentene (HFO1438), nonafluoropentene and the like. .. Examples of carbon dioxide include carbon dioxide in a liquid state, a subcritical state, and a supercritical state.
As the foaming agent, water, HFC, HC, HFO, and carbon dioxide may be used alone or in combination of two or more. The amount of the foaming agent used is preferably 5 to 40 parts by mass per 100 parts by mass of the above-mentioned polyol.

As the catalyst used for reacting the polyol with the polyisocyanate, an amine catalyst, a metal catalyst or the like which have been generally used conventionally can be used.
As the amine catalyst, a reactive amine catalyst (a compound having an active hydrogen group in the molecule) is particularly preferable, and for example, dimethylmethanolamine, dimethylethanolamine, 2- [methyl [2- (dimethylamino) ethyl] amino. ] Ethanol (TMAEEA), 2- [2- (dimethylamino) ethoxy] ethanol (DMAEE), 1,3-bis (dimethylamino) -2-propanol (TMHPDA), 4-methylpiperazin-1-ethanol, 3, Examples thereof include 3'-[3- (dimethylamino) propylimino] bis (2-propanol) (Thancat-DPA), 2-morpholinoethanol and the like. Commercially available products such as TOYOCAT RX7 (Tosoh Corporation), Polycat 16, Polycat 17, and DabcoWT (Air Products & Chemicals) can also be used.
As the metal catalyst, for example, stanas octoate; dibutyltin dilaurylate; lead octylate; potassium salts such as potassium acetate and potassium octylate can be used. In addition to these amine catalysts and metal catalysts, quaternary ammonium salts of fatty acids such as formic acid and acetic acid can also be used.
One of the above catalysts may be used alone, or two or more of the above catalysts may be used in combination as appropriate. The amount of the catalyst used is preferably about 0.1 to 15 parts by mass with respect to 100 parts by mass of the polyol.

As the defoaming agent used for the rigid polyurethane foam used in the present invention, a defoaming agent known in the art can be used. For example, Tegostab® B8232, B8841, B8443, B8465, B8486, B8466, B8450 (all from Evonik Degussa Japan Co., Ltd.); SF-2936F, SF-2937F, SF-2938F, SF-2945F, SZ-1605, A defoaming agent such as SZ-1642, SZ-1671, etc. (all of which are Toray Dow Corning Co., Ltd.) can be used.
One type of these foam stabilizers may be used alone, or two or more types may be used in combination.

The rigid polyurethane foam of the present invention has a density of 25 kg / m ³ or more and 50 kg / m ³ or less, and is hard and strong, so that the foam alone is difficult to bend.
The density is a value measured in accordance with JIS A 9511 by cutting out a test piece having a size of 100 mm × 100 mm × 100 mm from a rigid polyurethane foam obtained by free foaming in a wooden box.

The thermal conductivity of the rigid polyurethane foam of the present invention is preferably 0.024 W / (m · K) or less. The rigid polyurethane foam having a thermal conductivity in this range is excellent in heat insulating performance, and the heat insulating effect as a heat insulating board is improved. A test piece of 200 mm × 200 mm × 25 mm was cut out from a rigid polyurethane foam obtained by free foaming on a metal plate whose thermal conductivity was adjusted to 45 ° C., and Hidehiro was subjected to the heat flow metering method shown in JIS A 9511. It is a value measured at an average temperature of 23 ° C. using "Auto Lambda HC-074 Series" manufactured by Seiki Co., Ltd.

The core material 2 of the present invention may have a thickness of 5 mm or more, preferably 10 mm or more and 50 mm or less. Increasing the thickness of the core material improves the heat insulating performance, but if it is too thick, it becomes difficult to bend even if the face material of the present invention described later is laminated on both sides, and it becomes difficult to handle the heat insulating material.

The face material 3 of the present invention has a specific tensile strength of 5.0 Nm / g or more and 13.0% Nm / g or less in the length direction and the width direction of the core material 2. If the specific tensile strength is less than 5.0 Nm / g, the heat insulating board is easily bent, but the durability may be inferior such as the face material being torn by repeated bending. Further, if it exceeds 13.0 Nm / g, it is difficult to bend the heat insulating board. The specific tensile strength is a value measured in accordance with JIS P 8113.
Here, the length direction of the core material 2 is the arrow direction X shown in FIG. 1, the width direction is the arrow direction Y, and the arrow directions X and Y are orthogonal to each other. The heat insulating board can be bent by using a face material having a specific specific tensile strength in both the arrow directions X and Y.
For example, when the specific tensile strength of the face material is larger in the X direction than in the Y direction, the heat insulating board is likely to bend along the arrow direction Y.

Further, the face material 3 of the present invention preferably has a tensile elongation at break of 25% or more and 35% or less in the length direction and the width direction of the core material 2.
If the tensile elongation at break is less than 25%, it becomes difficult to bend the heat insulating board, and if it exceeds 35%, it becomes easy to bend, but the board warps and the dimensional stability deteriorates. The tensile elongation at break is a value measured in accordance with JIS P 8113.

As the face material 3 of the present invention, for example, a synthetic resin film, a non-woven fabric, a metal vapor-deposited film, or the like can be used alone or in combination of two or more.
Examples of the synthetic resin film include polyester films such as polyethylene films, polypropylene films and polyethylene terephthalate films, polyvinyl chloride films, and synthetic paper mixed with inorganic substances. Then, in order to improve the adhesiveness with the rigid polyurethane foam as the core material, for example, corona treatment or the like may be performed.
Non-woven fabrics include synthetic fibers such as polyester fiber, nylon fiber, vinylon fiber, acrylic fiber, urethane fiber and polyolefin fiber, natural fiber such as cotton, linen, silk and wool, and inorganic fiber such as glass fiber, carbon fiber and metal fiber. One type or a mixture of two or more types can be used.
Examples of the metal-deposited film include aluminum foil, copper foil, iron foil, lead foil, and the like, and lightweight aluminum foil can be preferably used.

The method for manufacturing the heat insulating board 1 of the present invention is not particularly limited.
For example, if one face material 3 is unwound on a conveyor, a hard polyurethane foam raw material is discharged onto the conveyor, and then the other face material 3 is unwound from above to sandwich the hard polyurethane foam, continuous production can be achieved. It is possible.
Alternatively, a hard polyurethane foam block prepared in advance may be cut out into a plate shape to form a core material 2, and a face material 3 may be attached to the surface thereof with an adhesive or the like to create a heat insulating board.

The heat insulating board 1 of the present invention can be easily bent while maintaining the strength of the rigid polyurethane foam. The heat insulating board 1 of the present invention may be evaluated by the minimum radius that can be bent (minimum bending radius). As shown in FIG. 2, the minimum bending radius is the radius R of virtual circles that overlap when a force is applied to both ends of the heat insulating board and the most bends. Although the minimum bending radius differs depending on the thickness and length of the heat insulating board, the heat insulating board of the present invention preferably has a minimum bending radius of 1000 mm or less.

Since the heat insulating board 1 of the present invention can be easily bent while maintaining the strength of the rigid polyurethane foam, it is possible to insulate the curved surface portion, and it is easy to fix the heat insulating board 1 to the curved surface portion and a person can stand on it during work. It is hard to dent even if it is placed or dropped, and it has excellent workability during heat insulation construction.
Objects having a curved surface include, for example, a drum can (200 L capacity), a cylindrical tank, a concrete structure having a curved surface, or a steel structure (for example, a roof or wall base, a freezing / cooling room, a storage warehouse). Silo, plant facility, simple FRP bridge, etc.), vehicles with curved surfaces such as airplanes, ships, submersible boats, tankers, and other small items using heat insulating materials (electrical appliances, floor heating appliances, DIY), etc. If a plurality of heat insulating boards of the present invention are used, the use is not restricted by the size of the object. Further, not only a single layer of the heat insulating board but also a plurality of sheets can be laminated and used in order to obtain an arbitrary thickness.

The method of fixing the heat insulating board 1 to the curved surface portion is not particularly limited, and for example, it can be fixed by using an adhesive or by winding it with a plastic binding band. FIG. 3 shows a state in which the heat insulating board of the present invention is fixed to a cylindrical container with a plastic binding band.

Although the present invention will be described with reference to examples, the present invention is not limited to the contents of the examples.

[Example 1]
A rigid polyurethane foam having a width of 910 mm, a length of 3000 mm, and a thickness of 20 mm was used as a core material, and a non-woven fabric surface material with a polyethylene film was laminated on both sides thereof to prepare a heat insulating board.
The rigid polyurethane foam used had a density of 25 kg / m ³ and a thermal conductivity of 0.024 W / (m · K). The specific tensile strength of the non-woven fabric facing material with a polyethylene film is 12.3 Nm / g in the length direction (X) of the core material, 6.1 Nm / g in the width direction (Y) of the core material, and the tensile elongation at break is , 27.3% in the length direction (X) of the core material and 31.0% in the width direction (Y) of the core material were used.

[Examples 2 to 5]
A heat insulating board was prepared in the same manner as in Example 1 except that the thickness of the rigid polyurethane foam was 10 mm, 30 mm, 40 mm, and 50 mm.

[Comparative Example 1]
A heat insulating board was prepared in the same manner as in Example 1 except that a kraft paper composite face material having a thickness of 50 μm (manufactured by Nihon Matai Co., Ltd., trade name “NPE 120”) was used. The specific tensile strength of the kraft paper composite face material is 64.0 Nm / g in the length direction (X) of the core material, 33.8 Nm / g in the width direction (Y) of the core material, and the tensile elongation at break is The core material used was 2.4% in the length direction (X) and 8.1% in the width direction (Y) of the core material.

[Comparative Example 2]
A rigid polyurethane foam having a thickness of 20 mm, a width of 910 mm, and a length of 3000 mm used in Example 1 was prepared without a face material.

[Comparative Example 3]
A polyethylene foam having a thickness of 20 mm, a width of 910 mm, and a length of 3000 mm without a face material was prepared. The flexible polyurethane foam used had a density of 29 kg / m ³ and a thermal conductivity of 0.037 W / (m · K).

In the core material, the density and thermal conductivity are values measured according to JIS A 9511 or JIS A 1412-2.
Further, in the face material, the specific tensile strength and the tensile elongation at break are the values measured in accordance with JIS P 8113.

The obtained heat insulating board was evaluated for bendability and heat insulating property as follows. The results are shown in Tables 1 and 2.

[Bendability]
As shown in FIG. 2, a force was applied to both ends of the heat insulating board, the state when bent was observed, and the evaluation was made as follows.

○ Bent and the core material is not destroyed when bent △ The core material is not destroyed when bent, but it is difficult to bend.
× Cannot be bent, or the core material is destroyed when bent

[Thermal insulation properties]
As shown in FIG. 3, each heat insulating board was fixed around a cylindrical container (drum, diameter 580 mm, 200 L capacity) using a plastic binding band. Next, 210 kg of the polyol component was put in a container and _{allowed to stand at 25 ° C. (T 0} ), and then the temperature in the thermostatic chamber was set to 40 ° C. and the mixture was stored for 5 hours. Then, the temperature T of the polyol component in the container was measured, and _{the value of (TT 0} ) was evaluated as follows. As the polyol component, a polyol component manufactured by Achilles Corporation and having a trade name of "Achilles Aeron FR-FO" was used. This polyol component is a mixture of aromatic polyester polyl, an amine catalyst, a flame retardant, a defoaming agent, water as a foaming agent, and HFO (hydrofluoroolefin). As the HFO, HFO-1233zd having a boiling point of 19 ° C. was used.

○ ( _{TT 0} ) is 5 ° C or lower, and the volatilization of HFO can be suppressed. × (TT ₀ ) exceeds 5 ° C, and HFO is likely to volatilize.

In Examples 1 to 5, the core material could be bent without being broken. Moreover, as a result of measuring the bendable minimum radius (mm) of Examples 1 to 5, it was 500 mm in Example 1, 250 mm in Example 2, and 1000 mm in Examples 3 to 5. However, in Example 5, since a force was required when bending as compared with Examples 3 and 4, the evaluation of bendability was set to Δ.

Further, Example 1 and Comparative Example 1 are the same except that the face materials are different, but in Example 1, the evaluation of bendability is ◯, whereas in Comparative Example 1, the heat insulating board does not bend and ×. Met. From this, it was confirmed that a bendable heat insulating board can be obtained by laminating the face material of the present invention on both sides of the hard polyurethane foam which is difficult to bend.
In Comparative Example 2, when only the rigid polyurethane foam in which the face material of the present invention was not laminated was used, the core material was broken when bent, and the bendability was evaluated as x. , It has been shown that the rigid polyurethane foam alone breaks when bent.

Further, in Comparative Example 3 in which polyethylene foam was used as the core material, the evaluation of bendability was ◯, but the heat insulating property was ×, which was inferior in heat insulating performance.

As described above, in the heat insulating board of the present invention, a face material having excellent heat insulating performance by using a rigid polyurethane foam as a core material and having a specific specific tensile strength in the length direction and the width direction of the core material is the core. Since it is laminated on both sides of the material, it can be easily bent while maintaining the strength of the rigid polyurethane foam. Therefore, it is possible to provide a heat insulating board capable of heat insulating a curved surface portion.

1 Insulation board 2 Core material 3 Face material 4 Cylindrical container (drum)
5 Cable tie C Virtual circle R Radius of virtual circle (bending radius)
M center point

Claims (4)

A heat insulating board made of rigid polyurethane foam as a core material and face materials laminated on both sides.
The specific tensile strength of the face material measured in accordance with JIS P 8113 is 5.0 Nm / g or more and 13.0 Nm / g or less in the length direction and the width direction of the core material. Bendable insulation board. The heat insulation according to claim 1, wherein the tensile elongation at break measured according to JIS P 8113 of the face material is 25% or more and 35% or less in the length direction and the width direction of the core material. board. The heat insulating board according to claim 1 or 2, wherein the thickness of the core material is 5 mm or more and 50 mm or less. The heat insulating board according to any one of claims 1 to 3, wherein the heat insulating board has a thermal conductivity of 0.024 W / (m · K) or less.

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