JP7293048B2 - insulation board - Google Patents

Description

The present invention relates to a bendable insulation board suitable for insulating curved surfaces.

In various fields, heat insulating materials are used for heat and cold insulation.
For example, flexible heat insulating sheets are used to insulate cylindrical containers such as drums and tanks, and objects having curved surfaces such as concrete structures having curved surfaces.
As a flexible heat insulating sheet, synthetic resin foam such as flexible polyurethane foam or polyethylene foam is processed into a plate or sheet, or a fibrous body such as glass fiber is compressed and molded into a plate or sheet. things are used.

However, flexible foam sheets such as flexible polyurethane foam and polyethylene foam do not have high heat insulation performance. Also, increasing the thickness of the sheet improves the heat insulation performance, but if it is too thick, the flexibility becomes poor and it becomes impossible to follow the curved surface. In addition, flexible polyurethane foam is not suitable for outdoor use because it easily absorbs water.

On the other hand, rigid polyurethane foam is used as a heat insulating material for buildings because of its excellent heat insulation performance, hardness and strength, but it is a synthetic resin foam with poor flexibility. Therefore, if rigid polyurethane foam processed into a plate (board) is used and bent to conform to a curved surface portion, there is a risk that it will break. Also, if the thickness of the board is reduced, there is a possibility that it will be bent, but the insulation performance will be reduced.
Even if the board is thick, it is possible to make it conform to the curved surface shape by applying strong pressure and forcibly bending it at the factory, but performance is likely to deteriorate, and transportation to the construction site is difficult. , 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 part, a method of arranging a plurality of tile-shaped or strip-shaped heat insulating materials on the curved surface part and covering them (Patent Document 1), and a heat insulating formwork in which the face material is laminated on the surface of the foam A method of bending a panel by providing a plurality of grooves on a surface that bends inward is known (Patent Document 2).
However, the methods of Patent Literatures 1 and 2 require a large number of steps, require a great deal of time and effort, and often do not provide sufficient adhesion to curved surfaces, resulting in poor heat insulation performance.

Also, in the case of large-scale structures, it is known to use a urethane spraying construction method by on-site foaming. With this method, it is easy to apply heat insulation to curved surfaces, but it is difficult to achieve the desired heat insulation performance because it is difficult to achieve accurate thickness compared to factory-produced products such as boards. In addition, the work is large-scale because it is carried out by a specialist using special equipment.

JP-A-59-208298 JP-A-4-258466

Thus, it has been difficult to insulate a curved surface portion using rigid polyurethane foam, which has excellent heat insulation performance and strength.

Accordingly, an object of the present invention is to provide a heat insulating board that uses a rigid polyurethane foam with high strength, has excellent heat insulating performance, and can insulate curved portions.

As a result of investigations aimed at solving the above problems, the inventors have 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 provides a bendable heat insulating board comprising a rigid polyurethane foam as a core material and face materials laminated on both sides thereof, wherein the specific tensile strength of the face material measured in accordance with JIS P 8113 is 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.

Although a rigid polyurethane foam alone is difficult to bend, the insulation board of the present invention is laminated with face materials having specific specific tensile strengths in the length direction and 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 according to JIS P 8113 of 25% or more and 35% or less in the length direction and width direction of the core material.

The face material has a specific specific tensile strength and a specific tensile elongation at break in the length direction and width direction of the core material, so that the force required when bending the insulation board can be suppressed and the bending can be facilitated. .

Moreover, 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. 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 insulation board that is excellent in heat insulation performance and is easy to bend.

The thermal conductivity of the insulation board of the present invention is 0.024 W/(m·K) or less. The thermal conductivity is a value measured according to JIS A 9511.

Here, the thermal conductivity is a value that indicates how easily heat is transmitted through a substance, and the smaller the value, the more difficult the heat is transmitted. The thermal conductivity of the heat insulating board depends on the heat insulating performance of the core rigid polyurethane foam. That is, by using a core material with high heat insulation performance, the heat insulation performance of the heat insulation board is also improved. In the present invention, a heat insulating board having excellent heat insulating performance has a thermal conductivity of 0.024 W/(m·K) or less.

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

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

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

The core material 2 of the present invention comprises a rigid polyurethane foam, for example, a foam obtained by mixing and reacting a polyisocyanate, a polyol such as 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.

Polyester polyols or polyether polyols can be suitably used as the polyols used in the rigid polyurethane foam used in the present invention, and these can be used alone or in combination of two or more.

As polyester polyols, there are polyols obtained by condensing polyhydric alcohols to polyhydric carboxylic acids, and polyols obtained by ring-opening polymerization of cyclic esters. Polyvalent carboxylic acids include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, and polyols composed of these anhydrides. On the other hand, polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, bisphenol A and the like. Among them, a polyester polyol having an aromatic ring is particularly preferable as the polyester polyol.
Although the hydroxyl value of the polyester polyol is not particularly limited, it is preferably 100 to 400 mgKOH/g.

Examples of polyether polyols include alcohols such as aliphatic alcohols, aromatic alcohols and polyhydric alcohols; aliphatic amines such as ethanolamine, diethanolamine, triethanolamine and ethylenediamine; group amines; Mannich condensation products and the like include polyether polyols obtained by addition polymerization of one or more of alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide. The species can be used alone, or two or more species can be used in combination as appropriate.
Of these polyether polyols, aromatic polyether polyols are particularly preferred because they lower the thermal conductivity.
Although the hydroxyl value of the polyether polyol is not particularly limited, it is preferably from 300 to 800 mgKOH/g.
A polymer polyol obtained by dispersing a polymer component such as vinyl acetate, polyacrylonitrile, or polyacrylonitrile/styrene copolymer in a polyether polyol may also be used. In particular, polymer polyols obtained by dispersing vinyl acetate or polyacrylonitrile/styrene copolymer in polyether polyols are preferably used.

Examples of the polyisocyanate to be reacted with the above polyol include diphenylmethane diisocyanate (MDI), polymeric diphenylmethane diisocyanate (polymeric MDI), and the like; these modified polyisocyanates, that is, products obtained by partial chemical reaction of polyisocyanates, such as polyisocyanates containing groups such as ester, urea, biuret, allophanate, carbodiimide, isocyanurate, urethane; and the like. These polyisocyanates can be used singly or in combination of two or more.

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

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

As the catalyst used for reacting the polyol and the polyisocyanate, conventionally used amine catalysts, metal catalysts, and the like can be used.
As the amine catalyst, a reactive amine catalyst (a compound having an active hydrogen group in the molecule) is particularly suitable, and examples include dimethylmethanolamine, dimethylethanolamine, 2-[methyl[2-(dimethylamino)ethyl]amino ] ethanol (TMAEEA), 2-[2-(dimethylamino)ethoxy]ethanol (DMAEE), 1,3-bis(dimethylamino)-2-propanol (TMHPDA), 4-methylpiperazine-1-ethanol, 3, 3′-[3-(dimethylamino)propylimino]bis(2-propanol) (Thancat-DPA), 2-morpholinoethanol and the like. Commercially available products such as TOYOCAT RX7 (Tosoh Corp.), Polycat 16, Polycat 17 and DabcoWT (Air Products) can also be used.
Examples of metal catalysts that can be used include stannus octoate; dibutyltin dilaurate; lead octylate; and potassium salts such as potassium acetate and potassium octylate. 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 them may be used in appropriate combination. 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 foam stabilizer used in the rigid polyurethane foam used in the present invention, any foam stabilizer known in the art can be used. For example, Tegostab (registered trademark) B8232, B8481, B8443, B8465, B8486, B8466, B8450 (all of Evonik Degussa Japan Co., Ltd.); Foam stabilizers such as SZ-1642 and SZ-1671 (both manufactured by Dow Corning Toray Co., Ltd.) can be used.
One of these foam stabilizers may be used alone, or two or more thereof 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.
The density is a value measured according to JIS A 9511 by cutting out a test piece of 100 mm×100 mm×100 mm from a rigid polyurethane foam obtained by free foaming in a wooden box and using the test piece.

Moreover, the thermal conductivity of the rigid polyurethane foam of the present invention is preferably 0.024 W/(m·K) or less. A rigid polyurethane foam having a thermal conductivity within this range is excellent in heat insulation performance, and the heat insulation effect as a heat insulation 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 temperature-controlled to 45 ° C., and the thermal conductivity was measured by the heat flow meter method shown in JIS A 9511. It is a value measured at an average temperature of 23° C. using “Autolamda 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 insulation performance, but if it is too thick, it becomes difficult to bend even if the later-described face material of the present invention is laminated on both sides, making it difficult to handle when performing insulation work.

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 width direction of the core material 2 . If the specific tensile strength is less than 5.0 Nm/g, the heat insulating board is easy to bend, but the durability may be poor such that the face material is broken by repeated bending. Moreover, when it exceeds 13.0 Nm/g, it is difficult to bend a heat insulation board. The specific tensile strength is a value measured according to 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. The insulating board can be bent by using a face material having a specific tensile strength in both directions of the arrows X and Y.
For example, when the specific tensile strength of the face material is greater in the X direction than in the Y direction, the insulation board tends to bend along the arrow direction Y.

Moreover, 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 width direction of the core material 2 .
When the tensile elongation at break is less than 25%, the insulating board becomes difficult to bend, and when 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 according to JIS P 8113.

As the face material 3 of the present invention, for example, a synthetic resin film, a non-woven fabric, a metal-deposited film, or the like can be used alone or in a combination of a plurality of laminated films.
Synthetic resin films include polyester films such as polyethylene films, polypropylene films, and polyethylene terephthalate films, polyvinyl chloride films, and synthetic paper mixed with inorganic substances. Then, for example, corona treatment or the like may be performed in order to improve the adhesiveness with the rigid polyurethane foam that is the core material.
Non-woven fabrics include synthetic fibers such as polyester fiber, nylon fiber, vinylon fiber, acrylic fiber, urethane fiber, and polyolefin fiber, natural fibers such as cotton, hemp, silk, and wool, and inorganic fibers such as glass fiber, carbon fiber, and metal fiber. can be used from 1 or 2 or more.
Also, examples of the metal-deposited film include aluminum foil, copper foil, iron foil, lead foil, and the like, and aluminum foil, which is lightweight, can be preferably used.

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

The insulation board 1 of the present invention can be easily bent while maintaining the strength of the rigid polyurethane foam. The insulation board 1 of the present invention may be evaluated by the minimum bendable radius (minimum bending radius). The minimum bending radius is, as shown in FIG. 2, the radius R of imaginary circles overlapping each other when force is applied to both ends of the insulating board and the board is bent most. Although the minimum bending radius varies depending on the thickness and length of the insulating board, the insulating board of the present invention preferably has a minimum bending radius of 1000 mm or less.

Since the insulation 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 moreover, it is easy to fix to the curved surface portion, and it is possible to prevent people from climbing on it during work. It does not easily dent even if it is placed on it or an object falls on it, and it is also excellent in workability during insulation work.
Objects with curved surfaces include, for example, drums (200 L capacity), cylindrical tanks, concrete or steel structures with curved surfaces (e.g., roof and wall foundations, freezer/refrigerator rooms, storage warehouses, etc.). silos, plant facilities, simple FRP bridges, etc.), vehicles with curved surfaces such as airplanes, ships, submersibles, and tankers, and other small items using heat insulating materials (electric appliances, floor heating equipment, DIY), etc. If a plurality of insulation boards of the present invention are used, the use is not limited by the size of the object. Moreover, not only a single layer of heat insulating board but also a plurality of layers can be laminated to obtain an arbitrary thickness.

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

The present invention will be described using examples, but 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 non-woven fabric surface materials with a polyethylene film were laminated on both sides of the core material 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). In addition, the specific tensile strength of the nonwoven fabric surface material with 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 breaking elongation is , 27.3% in the length direction (X) of the core material and 31.0% in the width direction (Y) of the core material.

[Examples 2 to 5]
Insulation boards were produced 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 (manufactured by Nihon Matai Co., Ltd., trade name “NPE 120”) having a thickness of 50 μm was used. In addition, 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 2.4% in the length direction (X) of the core material and 8.1% in the width direction (Y) of the core material were used.

[Comparative Example 2]
A rigid polyurethane foam having a thickness of 20 mm, a width of 910 mm, and a length of 3000 mm, which was 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 was prepared without a face material. The flexible polyurethane foam used had a density of 29 kg/m ³ and a thermal conductivity of 0.037 W/(m·K).

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

The obtained heat insulating board was evaluated for bendability and heat insulating properties as follows. Tables 1 and 2 show the results.

[Bendability]
As shown in FIG. 2, force was applied to both ends of the heat insulating board, and the state of bending was observed and evaluated as follows.

○ It can be bent and the core material does not break when bent. △ The core material does not break when bent, but it is difficult to bend.
× Unable to bend or the core material breaks when bent

[Thermal insulation properties]
As shown in FIG. 3, each heat insulating board was fixed around a cylindrical container (drum, diameter 580 mm, capacity 200 L) using a plastic binding band. Next, 210 kg of the polyol component was placed in the container, left to stand at 25° C. (T ₀ ), and stored for 5 hours at a constant temperature of 40° C. After that, the temperature T of the polyol component in the container was measured, and the value of (T−T ₀ ) was evaluated as follows. As the polyol component, a polyol component manufactured by Achilles Co., Ltd. under the trade name of "Achilles Aeron FR-FO" was used. This polyol component is a mixture of an aromatic polyester polyol, an amine catalyst, a flame retardant, a foam stabilizer, water and HFO (hydrofluoroolefin) as a blowing agent. HFO-1233zd having a boiling point of 19° C. was used as HFO.

○ (T−T ₀ ) is 5°C or less, and HFO volatilization can be suppressed. × (T−T ₀ ) exceeds 5°C, and HFO easily volatilizes.

Examples 1 to 5 could be bent without breaking the core material. In addition, the bendable minimum radius (mm) of Examples 1 to 5 was measured, and was 500 mm for Example 1, 250 mm for Example 2, and 1000 mm for Examples 3 to 5. However, in Example 5, since more force was required for bending than in Examples 3 and 4, the bendability was evaluated as Δ.

In addition, Example 1 and Comparative Example 1 are the same except that the face material is different. 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 a rigid polyurethane foam that is difficult to bend.
In Comparative Example 2, when only the rigid polyurethane foam not laminated with the face material of the present invention was used, the core material was destroyed when bent, so the bendability was evaluated as x. , rigid polyurethane foam alone has been shown to crack when bent.

In Comparative Example 3, in which polyethylene foam was used as the core material, the bendability was evaluated as ◯, but the heat insulation property was evaluated as x, indicating poor heat insulation performance.

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

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

Claims (4)

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

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