Foamed resin boards and partitions

Abstract

The present invention provides a foamed resin sheet made of a foamed resin containing polycarbonate, which is difficult to break under normal circumstances and can be easily broken by applying a predetermined external force in an emergency, as well as a partition sheet including the foamed resin sheet. [Solution] The foamed resin sheet 1 is a foamed resin sheet made using a foamed resin containing polycarbonate resin. The foamed resin sheet 1 comprises a core layer 2 made of foamed resin and a first skin layer 3 and a second skin layer 4 made of non-foamed resin, laminated on one and the other main surfaces of the core layer 2. The foamed resin sheet 1 has a first groove 5 opening on the surface of the first skin layer 3. The first groove has a depth d1. The depth d1 is greater than the thickness t1 of the first skin layer 3 and less than 50% of the thickness T1 of the foamed resin sheet 1.

Description

Technical Field

[0001] The present disclosure relates to a foamed resin plate containing a polycarbonate resin and a partition plate containing the foamed resin plate.

Background Art

[0002] Conventionally, partitions have been installed on balconies or verandas of apartment houses such as apartments. The partition functions as a partition board between neighboring houses in normal times. On the other hand, balconies or verandas function as evacuation routes in an emergency such as a fire or an earthquake. Therefore, the partition is required to be difficult to break under normal conditions and to have a predetermined strength that can be broken when a predetermined external force is applied by evacuees in an emergency.

[0003] Japanese Unexamined Patent Application Publication No. 2017-114125 (Patent Document 1) discloses a multilayer sheet and a multilayer container which is a molded body of the multilayer sheet. The multilayer sheet includes a polystyrene-based resin layer (outer layer), an intervening layer (middle layer) containing a polyolefin, and a polyethylene-based resin layer (inner layer) which is a foamed layer. The polystyrene-based resin layer and the polyethylene-based resin layer are adhered via the intervening layer. The intervening layer contains a polyolefin-based resin composition containing a modified polyolefin grafted with an unsaturated dicarboxylic acid anhydride. The multilayer container includes a plurality of storage recesses and a connecting portion that connects the openings of adjacent storage recesses. Each storage container is a molded body of the multilayer sheet. The storage recess and the connecting portion are integrally molded from the multilayer sheet, and a groove portion having a depth reaching from the inner layer surface to the outer layer of the connecting portion is formed. Thereby, the multilayer container has excellent adhesiveness in each layer and excellent fracture divisibility between a plurality of multilayer containers. Note that Patent Document 1 discloses that the multilayer container is used as a container for food or medical use, and preferably as a container for storing dairy products with strict food safety requirements (paragraph 0052 of the specification of Patent Document 1).

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-114125 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Multilayer containers, which are molded from multilayer sheets, can be easily separated by hand by providing grooves in the connecting parts that link the multilayer containers together. However, multilayer containers are mainly used for food or medical purposes, especially for dairy products, and from the viewpoint of ensuring a certain level of strength, multilayer sheets cannot be simply used as sheet material such as partitions. Furthermore, Patent Document 1 discloses that the depth of the grooves in the outer layer should be 50% or less of the thickness of the outer layer, and that the depth of the grooves should be 1 to 100 μm. However, the groove depth of multilayer containers used in the above-mentioned applications cannot be simply applied to sheet material such as partitions.

[0006] Therefore, the object of this disclosure is to provide foamed resin plates and partitions using a foamed resin containing polycarbonate, which are difficult to break under normal circumstances and can be easily broken by applying a predetermined external force in an emergency. [Means for solving the problem]

[0007] To solve the above problems, this disclosure employs the following solutions. Specifically, the foamed resin sheet according to this disclosure is a foamed resin sheet containing polycarbonate resin, comprising a core layer made of foamed resin, a first skin layer made of non-foamed resin laminated on one main surface of the core layer, and a second skin layer laminated on the other main surface of the core layer. The foamed resin sheet has a first groove opening on the surface of the first skin layer. The depth of the first groove is greater than the thickness of the first skin layer and less than 50% of the thickness of the foamed resin sheet.

[0008] The partition relating to this disclosure includes the foamed resin plate described above. [Effects of the Invention]

[0009] The foamed resin plate and partition according to this disclosure are difficult to break under normal circumstances, and can be easily broken by applying a predetermined external force in an emergency. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view showing a foamed resin plate according to an embodiment. [Figure 2] Figure 2 is a perspective view showing a modified example of a foamed resin plate. [Figure 3] Figure 3 is a cross-sectional view showing the foamed resin sheet shown in Figure 1. [Modes for carrying out the invention]

[0011] (Composition 1) The foamed resin sheet of the embodiment of the present disclosure is a foamed resin sheet containing polycarbonate resin, comprising a core layer made of foamed resin, a first skin layer made of non-foamed resin laminated on one main surface of the core layer, and a second skin layer laminated on the other main surface of the core layer. The foamed resin sheet has a first groove opening on the surface of the first skin layer. The depth of the first groove is greater than the thickness of the first skin layer and less than 50% of the thickness of the foamed resin sheet.

[0012] Such a foamed resin sheet is difficult to break under normal circumstances, but can be easily destroyed by applying a predetermined external force in an emergency.

[0013] (Configuration 2) The foamed resin plate of configuration 1 may have a second groove that opens onto the surface of the second skin layer. The depth of the second groove may be greater than the thickness of the second skin layer and less than 50% of the thickness of the foamed resin plate. This makes it difficult to break under normal circumstances, but can be easily broken by applying a predetermined external force in an emergency.

[0014] (Composition 3) A foamed resin plate having configuration 1 or 2, wherein the first skin layer or the second skin layer may have a thickness of 10 to 20% of the thickness of the foamed resin plate.

[0015] (Composition 4) The foamed resin plate is one of the three components (1 to 3), and the foamed resin plate may have a breaking load of 20N to 60N.

[0016] (Composition 5) The partition in the embodiment of this disclosure includes one of the foamed resin plates of any of the components 1 to 4.

[0017] Hereinafter, embodiments of the foamed resin plate 1 of this disclosure will be specifically described with reference to Figures 1 to 3. In the figures, the same and corresponding components are denoted by the same reference numerals, and the same explanation will not be repeated. In order to make the explanation easier to understand, the components in the drawings referred to below are shown in a simplified or schematic manner, and some components are omitted.

[0018] The foamed resin plate 1 contains a polycarbonate resin. The foamed resin plate 1 according to the present embodiment is in a sheet shape or a plate shape. However, the foamed resin plate 1 may be curved, or may be processed into a wave shape or a square wave shape or the like. The foamed resin plate 1 may be manufactured, for example, by co-extrusion molding of a molten polycarbonate resin. The resin used in the present disclosure may include other engineering plastics excluding the polycarbonate resin together with the polycarbonate resin. The engineering plastic is a thermoplastic resin having a load deflection temperature of 100°C or higher. The engineering plastic is, for example, in addition to a polycarbonate resin (PC), a modified polyphenylene ether (m-PPE), a syndiotactic polystyrene (SPS), and the like. The resin used for the foamed resin plate 1 of the present disclosure can include at least one selected from the group consisting of these engineering plastics. The foamed resin plate 1 can contain at least 50% by mass or more of a polycarbonate resin from the viewpoint of ensuring a predetermined strength. Further, an ultraviolet absorber, an anti-aging agent, and the like may be added to the resin material of the foamed resin plate 1.

[0019] The foamed resin plate 1 can be used not only as the above-described partition plate but also as other partition plates and the like. That is, the foamed resin plate 1 may be used in a scenario where it is easy to cut a large-sized foamed resin plate 1 into a small size by a predetermined external force, for example, using a cutting tool or by hand without using a tool, and its use is not limited. Further, in the present disclosure, the "predetermined external force" varies depending on the use of the foamed resin plate 1. For example, when the foamed resin plate 1 is used as the above-described partition plate, the "predetermined external force" is an external force by the bare hands of an evacuee, an external force when kicked, or an external force when using a tool such as a hammer.

[0020] As shown in FIG. 1, the foamed resin plate 1 has a core layer 2, a skin layer 3 laminated on one main surface of the core layer 2, and a skin layer 4 laminated on the other main surface of the core layer 2.

[0021] The core layer 2 is made of a foamed resin. In the present disclosure, the foamed resin refers to a resin having an average porosity of 5% to 95%. That is, it can also be said that the core layer 2 has an average porosity of 5 to 95%. The core layer 2 can be formed by foam molding a molten resin material. Therefore, the core layer 2 has a large number of air bubbles.

[0022] As shown in FIG. 2, the skin layer 3 is made of a non-foamed resin. The skin layer 3 is not foam molded. In the present disclosure, the non-foamed resin refers to a resin having an average porosity of 0% or more and less than 5%. That is, it can also be said that the skin layer 3 has an average porosity of 0% or more and less than 5%.

[0023] The skin layer 3 may be made of a thermoplastic resin that can be well adhered to the core layer 2. More specifically, it is particularly preferable that the resin material of the skin layer 3 is the same as the resin material of the core layer 2. Further, the skin layer 3 can be composed of a reinforced resin containing an inorganic filler in order to strengthen the skin layer 3. With these configurations of the skin layer 3, it is possible to achieve weight reduction and strength improvement while efficiently improving the strength. The inorganic filler is, for example, glass fiber, carbon fiber, aramid fiber, talc, mica, etc.

[0024] The skin layer 4 is the same as the skin layer 3 except that it is laminated on the other main surface of the core layer 2. Therefore, a specific description of the skin layer 4 is omitted.

[0025] The skin layer 3 or the skin layer 4 can be laminated on the core layer 2 by adhering it to one main surface or the other main surface of the core layer 2 after being separately formed from the core layer 2. Also, the skin layer 3 or the skin layer 4 may be integrally laminated with the core layer 2 by coextrusion molding. That is, a clear interface may not be formed between the core layer 2 and the skin layer 3, or between the core layer 2 and the skin layer 4, and the core layer 2 and the skin layer 3 or the skin layer 4 may be formed as a continuous integral body.

[0026] Here, the average porosity (%) of core layer 2, skin layer 3, and skin layer 4 can be determined from the ratio of the cross-sectional area of ​​foam cells per unit cross-sectional area in the foamed resin sheet 1. More specifically, the average porosity is calculated as follows. First, the foamed resin sheet 1 is cut in the thickness direction, and the cross section is photographed at 25x magnification using a scanning electron microscope (Hitachi, Ltd., model number "Miniscope(registered trademark), TM4000Plus2"). In the captured cross-sectional image, the foamed resin sheet 1 is divided into 10 equal parts with a width of 1 mm in the thickness direction, and 10 sections arranged in a row along the thickness direction of the foamed resin sheet 1 are extracted at three locations: the center and both ends in the width direction of the foamed resin sheet 1. Next, the closed cells contained in each section are extracted, and the cross-sectional area of ​​these closed cells is calculated using the cell diameter that maximizes the cell size of these closed cells, and assuming that the closed cells are circular. The average value of the cross-sectional area of ​​the closed cells contained in each section is calculated, and the porosity for each section is calculated by dividing this average value by the cross-sectional area of ​​the section. Next, the average value of the porosity of the three sections in the same thickness region in the three rows mentioned above is calculated. This average value of the porosity of the three sections in the same thickness region is called the average porosity. In order to calculate the average porosity in more detail in the thickness direction, the foamed resin plate 1 may be divided into 11 or more equal parts.

[0027] The foamed resin plate 1 has a groove 5 that opens onto the surface of the skin layer 3. The groove 5 has a depth d1. Details of the depth d1 of the groove 5 will be described later.

[0028] The foamed resin plate 1 may have grooves 6 that open to the surface of the skin layer 4, as shown in Figure 2. The grooves 6 may be formed with a predetermined distance from the grooves 5 when viewed from above, that is, when viewed from the surface side of the skin layer 3. In other words, the grooves 6 may be arranged so as not to overlap with the grooves 5 when viewed from above. The grooves 6 have a depth d2. Details of the depth d2 of the grooves 6 will be described later.

[0029] The cross-sectional shape of the groove 5 or groove 6 is preferably V-shaped, as shown in Figures 1 to 3. This makes it possible to obtain a foamed resin plate 1 that is less likely to break under normal conditions and can be easily destroyed by applying a predetermined external force in an emergency. The cross-sectional shape of the groove 5 or groove 6 is not limited to V-shape, but may be concave (U-shaped), U-shaped, semicircular, or semi-elliptical. The groove 5 or groove 6 may also be formed by cutting notches in the surface of the foamed resin plate 1 using a cutting tool such as a utility knife or a rotary blade.

[0030] Next, using Figure 3, we will explain in detail the relationship between the thickness T1 of the foamed resin plate 1, the thickness T2 which is 50% of the total thickness (T1) of the foamed resin plate 1, the thickness t1 of the skin layer 3, the thickness t2 of the skin layer 4, the depth d1 of the groove 5, and the depth d2 of the groove 6.

[0031] The foamed resin sheet 1 has a thickness T1. The thickness T1 of the foamed resin sheet 1 is not particularly limited, but for example it can be 1.5 mm to 3.0 mm. The thickness T1 of the foamed resin sheet 1 is preferably 1.0 mm to 10.0 mm, preferably 1.5 mm to 5.0 mm, and more preferably 3.0 to 5.0 mm. In other words, the thickness T1 of the foamed resin sheet 1 is preferably 1.0 mm or more, preferably 1.5 mm or more, more preferably 3.0 mm or more, and 10.0 mm or less, preferably 5.0 mm or less.

[0032] Skin layer 3 has a thickness t1. Skin layer 4 has a thickness t2.

[0033] As described above, when the core layer 2, skin layer 3, and skin layer 4 are integrally formed by co-extrusion molding, the thickness t1 of skin layer 3 and the thickness t2 of skin layer 4 can be measured as follows. Specifically, the cross-section obtained by cutting the foamed resin plate 1 in the thickness direction along the width direction is observed using a microscope. In this disclosure, a KEYENCE model VHX-60000 microscope is used. The magnification of the microscope should be such that the diameter of the bubbles at the interface between the skin layer 3 and the core layer 2 of the foamed resin plate 1 can be confirmed. In the cross-sectional view of the foamed resin plate 1, from among the many bubbles present, 15 bubbles close to the surface of the foamed resin plate 1 are selected on each virtual boundary line obtained by dividing the cross-section of the foamed resin plate 1 into 16 equal parts in the width direction, and the bubble closest to the surface of the foamed resin plate 1 is identified. A virtual line is drawn passing through the upper end of this closest bubble and perpendicular to the thickness direction. The area inside the virtual line in the thickness direction is defined as the core layer 2, and the area outside the virtual line in the thickness direction is defined as the skin layer 3. The boundary between core layer 2 and skin layer 4 is defined similarly, and the thickness t1 of skin layer 3 and the thickness t2 of skin layer 4 are measured.

[0034] The groove 5 has a depth d1 along the thickness direction of the foamed resin plate 1. The depth d1 of the groove 5 is greater than the thickness t1 of the skin layer 3. The depth d1 of the groove 5 is less than the thickness T2, which is 50% of the thickness T1 of the foamed resin plate 1. In other words, the depth d1 of the groove 5 is less than the sum of the thickness t1 of the skin layer 3 and 50% of the thickness (T1-(t1+t2)) of the core layer 2. That is, the deepest part of the groove 5 is located between the boundary between the core layer 2 and the skin layer 3 and the thickness direction center C of the foamed resin plate 1 (or the thickness direction center of the core layer 2).

[0035] If the depth d1 of the groove 5 is too large, the foamed resin plate 1 will be easily destroyed under normal circumstances. On the other hand, if the depth d1 of the groove 5 is too small, it will be difficult to destroy the foamed resin plate 1 with a predetermined external force in an emergency. From this viewpoint, it is preferable that the depth d1 of the groove 5 be greater than the thickness t1 of the skin layer 3, and less than the sum of the thickness t1 of the skin layer 3 and 50% of the thickness t2 of the core layer 2, preferably less than the sum of the thickness t1 of the skin layer 3 and 40% of the thickness t2 of the core layer 2, and even more preferably less than the sum of the thickness t1 of the skin layer 3 and 30% of the thickness t2 of the core layer 2.

[0036] By providing the groove 5 in this way, it is possible to obtain a foamed resin plate 1 that is difficult to break under normal circumstances, and can be easily broken by applying a predetermined external force in an emergency.

[0037] The skin layer 3 has a thickness t1 that is 10-20% of the thickness T1 of the foamed resin plate 1. This makes it possible to achieve both strength and lightness in the foamed resin plate 1.

[0038] The relationship between the depth d2 of the groove 6, the thickness T1 of the foamed resin plate 1, the thickness T2 of 50% of the thickness T1 of the foamed resin plate 1, and the thickness t2 of the skin layer 4 is the same as the relationship between the depth d1 of the groove 5, the thickness T1 of the foamed resin plate 1, the thickness T2 of 50% of the thickness T1 of the foamed resin plate 1, and the thickness t1 of the skin layer 3 described above, so an explanation is omitted.

[0039] The foamed resin sheet 1 should have a breaking load of 20N to 60N, from the viewpoint of being difficult to break under normal conditions, but easily breakable by applying a predetermined external force in an emergency. The breaking load of the foamed resin sheet 1 can be measured by a three-point bending test in accordance with JIS K 7171. The breaking load of the foamed resin sheet 1 should preferably be 40N to 60N, more preferably 50N to 60N, from the viewpoint of ensuring strength under normal conditions while being easy to break in an emergency. This makes it possible to obtain a foamed resin sheet 1 that is even more difficult to break under normal conditions, and can be broken by applying a predetermined external force in an emergency. In other words, the breaking load of the foamed resin sheet 1 should preferably be 20N or more, preferably 30N or more, more preferably 50N or more, and 60N or less.

[0040] The foamed resin sheet 1 can reduce the amount of resin used through foam molding. As a result, the foamed resin sheet 1 according to this embodiment can contribute to improved resource utilization efficiency, reduced transportation burden, reduced energy consumption, and reduced CO2 emissions. By providing the foamed resin sheet 1 to society, it is possible to contribute to achieving three of the 17 Sustainable Development Goals (SDGs) established by the United Nations: Goal 7 (Affordable and Clean Energy), Goal 9 (Industry, Innovation and Infrastructure), and Goal 11 (Sustainable Cities and Communities).

[0041] Although embodiments have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the disclosure. [Examples]

[0042] As shown in Table 1 below, test specimens (foamed resin boards) for Examples 1 to 16 and Comparative Examples 1 to 3 were prepared, and a three-point bending test was performed to measure the breaking load of each test specimen.

[0043] The three-point bending test was conducted in accordance with JIS K 7171, specifically as follows. First, rectangular test pieces with a width of 10 mm and a length of 80 mm were prepared using a punching machine. Next, a groove along the width direction was formed on the surface of each test piece at the center of the length direction using a utility knife (see Figure 1). Finally, the three-point bending test was performed on each test piece by applying a load to the center of the test piece, with fulcrums at positions 16 times the thickness of the test piece, extending from the center of the length direction to both ends of the length direction. In this disclosure, the three-point bending test can be performed using, for example, a precision universal testing machine (manufactured by Shimadzu Corporation, model number "AGS-J").

[0044] In this embodiment, each test specimen was evaluated as follows. The breaking load of a foamed resin plate (without grooves) with a thickness T1 of 3 mm and a skin layer on the main surface of one and the other of the core layer was approximately 70 N. Therefore, as a guideline for evaluation, it was evaluated that a foamed resin plate with grooves having a breaking load of 20 N or more from the viewpoint of being difficult to break under normal conditions, and 60 N or less from the viewpoint of being easily broken by applying a predetermined external force in an emergency, can effectively solve the problems of this disclosure.

[0045] [Table 1]

[0046] (Comparison of Examples 1-8 and Comparative Examples 1-3) Comparing Examples 1-8 and Comparative Examples 1-3, where the thickness T1 of the test specimens was 3 mm, Examples 1-6, where the groove depth d1 was greater than the skin layer thickness t1 and less than the thickness T2 (50% of the total thickness T1 of the test specimen), exhibited a breaking load of 20 N to 60 N. In particular, Example 3, with a breaking load of 40 N or more, and Examples 1, 2, 7, and 8, with breaking loads of 50 N or more, are considered to be able to secure the required strength under normal conditions and are considered useful when using foamed resin boards as partitions. On the other hand, in Comparative Example 1, where the skin layer thickness t1 and the groove depth d1 were the same, and in Comparative Example 3, where the groove depth d1 was less than the skin layer thickness t1, the breaking load was not significantly different from the 70 N in the case without grooves. Therefore, the test specimens of Comparative Examples 1 and 3 are less likely to break in emergencies. Furthermore, in Comparative Example 2, the groove depth d1 was greater than the thickness T2 (50% of the total thickness T1 of the test specimen), resulting in a significantly reduced breaking load. Therefore, it is thought that it has become more susceptible to damage even under normal circumstances.

[0047] (Examples 3, 7, and 8) In Examples 3, 7, and 8, the thickness T1 of each test specimen and the depth d1 of the groove were kept the same, and the thickness t1 of the skin layer was varied during the test. As a result, in Example 3, where the ratio of the skin layer thickness t1 to the thickness T1 of the test specimen (hereinafter referred to as the thickness ratio) was 5%, the breaking load was less than 50N. In Example 7, where the skin layer thickness ratio was 12%, and in Example 8, where the skin layer thickness ratio was 18%, the breaking load was 50N or more. This indicates that, to achieve a breaking load of 50N or more, it is preferable to set the skin layer thickness ratio to 10% to 20%. It should be noted that when the skin layer thickness ratio exceeds 20%, the breaking load gradually approaches 60N, and it is considered difficult to ensure the lightweight nature of the test specimen (foamed resin plate).

[0048] (Examples 9-16) In Examples 9-16, the test specimen thickness was changed from that of Examples 1-8. As a result, in Examples 9-13, where the specimen thickness was 2 mm, the breaking load was smaller than that of the specimens in Examples 1-8, and in Examples 14-16, where the specimen thickness was 1.5 mm, the breaking load was even smaller. Considering the trend of the breaking load in Examples 1-16, it was found that in order to achieve a breaking load of 20 N or more, it is preferable to set the thickness of the specimen (foamed resin plate) to 1.0 mm or more, and more preferably 1.5 mm or more. However, in Example 16, since the breaking load was less than 20 N, it is thought that it was more easily broken unintentionally under normal circumstances compared to Examples 1-15. Nevertheless, compared to Comparative Example 2, which had a larger thickness, in Example 16, by making the depth of the groove d1 larger than the thickness t1 of the skin layer and smaller than 50% of the thickness of the specimen, it was possible to increase the breaking load compared to Comparative Example 2. Furthermore, based on the results of Examples 1 to 8, it is considered that in order to achieve a breaking load of 50 N or more, the thickness of the test specimen should be 10 mm or less, preferably 5 mm or less, and more optimally around 3 mm.

[0049] It should be noted that the aforementioned "20N to 60N" breaking load is merely a guideline for test specimens of the predetermined thicknesses in Examples 1 to 16 and Comparative Examples 1 to 3. From the perspective of solving the problems of this disclosure, in order to provide a foamed resin plate that is difficult to break under normal circumstances and can be easily broken by applying a predetermined external force in an emergency, it can be sufficiently inferred from the test results in Table 1 above that, even when the thickness of the test specimen is changed, the depth of the groove should be greater than the thickness of the skin layer and less than 50% of the thickness of the test specimen. [Explanation of Symbols]

[0050] 1 Foamed resin sheet, 2 Core layer, 3 Skin layer, 4 Skin layer, 5 Groove, 6 Groove, d1 Depth of groove, d2 Depth of groove, t1 Thickness of skin layer, t2 Thickness of skin layer, T1 Thickness of foamed resin sheet, T2 Thickness of 50% of foamed resin sheet

Claims

1. A foamed resin sheet containing polycarbonate resin, A core layer made of foamed resin, It consists of a non-foaming resin, and a first skin layer laminated on one main surface of the core layer, The core layer comprises a second skin layer laminated on the other main surface of the core layer, The foamed resin plate has a first groove that opens onto the surface of the first skin layer, A foamed resin plate in which the depth of the first groove is greater than the thickness of the first skin layer and less than 50% of the thickness of the foamed resin plate.

2. A foamed resin board according to claim 1, The foamed resin plate has a second groove that opens onto the surface of the second skin layer, A foamed resin plate in which the depth of the second groove is greater than the thickness of the second skin layer and less than 50% of the thickness of the foamed resin plate.

3. A foamed resin board according to claim 1, The first skin layer is a foamed resin board having a thickness of 10 to 20% of the thickness of the foamed resin board.

4. A foamed resin board according to any one of claims 1 to 3, The foamed resin board is a foamed resin board having a breaking load of 20 N to 60 N.

5. A partition comprising a foamed resin board according to any one of claims 1 to 3.

Images