Foamed resin composition, method for producing the same, and foamed molded article produced thereby

Abstract

The foamable resin composition of the present invention comprises about 100 parts by weight of polypropylene; 2 / g ~ approx. 15m 2 / g of zinc oxide, about 0.1 parts by weight to about 4 parts by weight of aliphatic alcohol, about 0.08 parts by weight to about 2.5 parts by weight of a surfactant. The foamable resin composition is excellent in antibacterial properties, foamability, foam moldability, etc.

Description

[Technical Field]

[0001] The present invention relates to a foaming resin composition, a method for producing the same, and a foamed molded article produced thereby. More specifically, the present invention relates to a foaming resin composition with excellent antibacterial properties, foaming properties, foam moldability, etc., a method for producing the same, and a foamed molded article produced thereby. [Background technology]

[0002] By introducing a foamed resin composition into a high-pressure reactor together with water and utilizing carbon dioxide gas or the like as a foaming agent, a foamed resin composition in the form of foamed particles can be produced by reducing the pressure and discharging under constant temperature and pressure conditions. The produced foamed particles can then be filled into a mold, heated, and fused to produce a molded product (foamed molded body). Because the molded products produced in this way have excellent properties such as high strength, light weight, cushioning, waterproofing, heat retention, and thermal insulation, they are used in a variety of fields, such as packaging materials for home appliances, boxes for agricultural and marine products, floats, and insulation materials for building materials.

[0003] To impart antibacterial properties to foamed resin compositions, antibacterial agents such as silver nanoparticles, copper particles, and zinc oxide particles can be introduced during the manufacturing process of the foamed resin composition. However, such antibacterial agents may not be suitable for the manufacturing process of foamed resin compositions due to issues with specific gravity and / or particle size, leading to difficulties in producing foamed products, such as reduced fusion properties.

[0004] Therefore, there is a need to develop foamed resin compositions that are excellent in antibacterial properties, foaming properties, and foam moldability.

[0005] The background art of this invention is disclosed in Korean Patent No. 10-0833453, etc. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The objective of the present invention is to provide a foamed resin composition that is excellent in antibacterial properties, foaming properties, foam moldability, and the like.

[0007] Another object of the present invention is to provide a method for producing the foamed resin composition.

[0008] Another object of the present invention is to provide a foamed molded article formed from the foamed resin composition.

[0009] All of the aforementioned and other objectives of the present invention can be achieved by the present invention as described below. [Means for solving the problem]

[0010] 1. One aspect of the present invention relates to a foamed resin composition. The foamed resin composition comprises approximately 100 parts by weight of polypropylene; with an average particle size of approximately 100 nm to approximately 300 nm and a specific surface area BET of approximately 5 m². 2 / g ~ approx. 15m 2 It contains approximately 0.1 to 4 parts by weight of zinc oxide per gram; approximately 0.08 to 2.5 parts by weight of aliphatic alcohol; and approximately 0.08 to 2.5 parts by weight of surfactant.

[0011] 2. In the specific example of paragraph 1 above, the polypropylene may include one or more of propylene homopolymers, propylene-ethylene random copolymers, and ethylene-propylene copolymers.

[0012] 3. In the specific examples of 1 or 2 above, the aliphatic alcohol may be an aliphatic alcohol having 6 to 22 carbon atoms.

[0013] 4. In the specific examples of 1 to 3 above, the surfactant may include one or more of glyceryl monostearate, polyethylene glycol, polyoxyethylene alkyl ether, and polyoxyethylene alkylamine.

[0014] 5. In the specific examples described in 1 to 4 above, the weight ratio of zinc oxide to the surfactant may be approximately 1:0.09 to approximately 1:2.5.

[0015] 6. In the specific examples 1 to 5 above, the weight ratio of the aliphatic alcohol and the surfactant can be from about 1:0.1 to about 1:10.

[0016] 7. In the specific examples 1 to 6 above, the foamed resin composition can be in the form of foamed particles produced by foaming a resin composition containing the polypropylene, zinc oxide, aliphatic alcohol and surfactant at a foaming ratio of about 10 times to about 80 times and an average cell size of about 50 μm to about 300 μm.

[0017] 8. In the specific examples 1 to 7 above, the foamed resin composition can have antibacterial activity values of about 2 to about 7 respectively when measured after inoculating Staphylococcus aureus and Escherichia coli on a test piece of 5 cm × 5 cm size according to the JIS Z 2801 antibacterial evaluation method and culturing at 35 °C and RH 90% for 24 hours.

[0018] 9. In the specific examples 1 to 8 above, the foamed resin composition can have a foaming ratio of about 20 times and an average cell size of about 80 μm to about 200 μm.

[0019] 10. Another aspect of the present invention relates to a method for producing a foamed resin composition. The production method includes mixing a resin composition containing about 100 parts by weight of polypropylene; about 0.1 part by weight to about 4 parts by weight of zinc oxide with an average particle diameter of about 100 nm to about 300 nm and a BET specific surface area of about 5 m 2 / g to about 15 m 2 / g; about 0.08 part by weight to about 2.5 parts by weight of an aliphatic alcohol; and about 0.08 part by weight to about 2.5 parts by weight of a surfactant with a dispersion medium containing water and a dispersant to produce a mixture; and then adding a foaming agent to the mixture and foaming it at a foaming ratio of about 10 times to about 80 times and an average cell size of about 50 μm to about 300 μm.

[0020] 11. In the specific example 10 above, the foaming is carried out by maintaining the mixture to which the foaming agent has been added at a temperature condition of about 130 °C to about 160 °C and a pressure of about 20 kgf / cm 2 to about 50 kgf / cm 2After heating and pressurizing to achieve the pressure conditions, it can be exposed to normal temperature and atmospheric pressure conditions.

[0021] 12. Another aspect of the present invention relates to a foamed molded body. The foamed molded body is characterized in that the foaming resin composition according to any one of the above 1 to 9 is filled into a mold and formed by heating and fusing.

Effect of the Invention

[0022] The present invention has the effect of an invention that provides a foaming resin composition excellent in antibacterial properties, foaming properties, foam molding properties, etc., a method for producing the same, and a foamed molded body produced thereby.

Modes for Carrying Out the Invention

[0023] [Best Mode for Carrying Out the Invention] Hereinafter, the present invention will be described in detail.

[0024] The foaming resin composition according to the present invention contains (A) polypropylene; (B) zinc oxide; (C) aliphatic alcohol; and (D) surfactant.

[0025] In this specification, "a~b" representing a numerical range is defined as "≧a and ≦b".

[0026] (A) Polypropylene The polypropylene according to a specific example of the present invention can include, as a base resin for forming a foaming resin composition and a foamed molded body, a propylene homopolymer; a propylene-ethylene random copolymer; an ethylene-propylene copolymer in which a propylene homopolymerized part and an ethylene-propylene copolymerized part are polymerized stepwise in a reactor; or a combination thereof, etc. For example, a propylene-ethylene random copolymer can be used.

[0027] In a specific example, the polypropylene may have a melt-flow index measured by ASTM D1238 under the load condition of 230°C and 2.16 kg of about 1 g / 10 min to about 50 g / 10 min, for example, about 5 g / 10 min to about 30 g / 10 min. Within this range, the foaming resin composition can be excellent in mechanical strength, molding processability, foaming property, etc.

[0028] (B) Zinc oxide The zinc oxide according to a specific example of the present invention can be applied together with an aliphatic alcohol and a surfactant to improve antibacterial properties, foaming properties, foam molding properties, etc. without degrading the mechanical properties of the molded product of the foaming resin composition. It has an average particle size of about 100 nm to about 300 nm and a specific surface area BET of about 5 m 2 / g to about 15 m 2 / g of zinc oxide can be used.

[0029] In a specific example, the zinc oxide may have an average particle size (D50) measured using a particle size analyzer (Beckman Coulter, equipped with Laser Diffraction Particle Size Analyzer LS I3 320) of about 100 nm to about 300 nm, for example, about 120 nm to about 200 nm. Also, the zinc oxide has a specific surface area BET measured by a BET analysis equipment (Micromeritics, equipped with Surface Area and Porosity Analyzer ASAP 2020) using the nitrogen gas adsorption method of about 5 m 2 / g to about 15 m 2 / g, for example, about 8 m 2 / g to about 12 m 2 / g, and the purity can be about 99% or more. Outside this range, the antibacterial properties, foaming properties, foam molding properties, etc. of the foaming resin composition may decrease.

[0030] In specific examples, the zinc oxide may be included in an amount of about 0.1 parts by weight to about 4 parts by weight, for example, about 0.2 parts by weight to about 2.5 parts by weight, per about 100 parts by weight of the polypropylene. If the zinc oxide content is less than about 0.1 parts by weight per about 100 parts by weight of the propylene, the antibacterial properties of the foamed resin composition may decrease, and if it exceeds about 4 parts by weight, the foaming properties, foam moldability (fusion properties), mechanical properties, etc. of the foamed resin composition may decrease.

[0031] (C) Faliphatic alcohols An example of the present invention is an aliphatic alcohol that, when applied together with zinc oxide and a surfactant, can improve the antibacterial properties, foaming properties, and foam moldability of a foamed resin composition without degrading its mechanical properties. Aliphatic alcohols with 6 to 22 carbon atoms can be used.

[0032] In specific examples, the aliphatic alcohol can be 1-octadecanol, 3-methylene-3-pentanol, 1-heptanol, 1-nonanol, or combinations thereof.

[0033] In specific examples, the aliphatic alcohol may be included in an amount of about 0.08 parts by weight to about 2.5 parts by weight, for example, about 0.1 parts by weight to about 2.2 parts by weight, per about 100 parts by weight of polypropylene. If the content of the aliphatic alcohol is less than about 0.08 parts by weight per about 100 parts by weight of propylene, the antibacterial properties of the foamed resin composition may decrease, and if it exceeds about 2.5 parts by weight, the foaming moldability (foaming properties, fusion properties, etc.) and mechanical properties of the foamed resin composition may decrease.

[0034] (D) Surfactants One specific example of the surfactant according to the present invention can be applied together with zinc oxide and an aliphatic alcohol to improve the antibacterial properties, foaming properties, foam moldability, etc., of a foamed resin composition without degrading its mechanical properties.

[0035] In specific examples, the surfactant may be a nonionic surfactant and may include one or more of glyceryl monostearate, polyethylene glycol, polyoxyethylene alkyl ether, and polyoxyethylene alkylamine.

[0036] In specific examples, the surfactant may be included in an amount of about 0.08 parts by weight to about 2.5 parts by weight, for example, about 0.1 parts by weight to about 2.2 parts by weight, per about 100 parts by weight of the polypropylene. If the amount of the surfactant is less than about 0.08 parts by weight per about 100 parts by weight of the propylene, the antibacterial properties of the foamed resin composition may decrease, and if it exceeds about 2.5 parts by weight, the foaming moldability (foaming properties, fusion properties, etc.) and mechanical properties of the foamed resin composition may decrease.

[0037] In a specific example, the weight ratio of zinc oxide to the surfactant (zinc oxide:surfactant) can be approximately 1:0.09 to approximately 1:2.5. Within this range, the antibacterial properties, foaming properties, foam moldability, etc., of the foaming composition can be improved.

[0038] In specific examples, the weight ratio of the aliphatic alcohol to the surfactant (aliphatic alcohol:surfactant) can be approximately 1:0.1 to approximately 1:10. Within this range, the antibacterial properties, foaming properties, foam moldability, etc., of the foaming composition can be improved.

[0039] A foamed resin composition according to one specific example of the present invention may be in the form of foamed particles produced by foaming a resin composition containing polypropylene, zinc oxide, aliphatic alcohol, and a surfactant at a foaming ratio of about 10 to about 80 times and with an average cell size of about 50 μm to about 300 μm.

[0040] In a specific example, the resin composition may be obtained in pellet form by mixing the constituent components and melt-extruding them using a conventional single-screw or twin-screw extruder at a temperature of approximately 150°C to approximately 240°C, for example, approximately 160°C to approximately 230°C.

[0041] In a specific example, the foamed particles (foamable resin composition) may have a foaming ratio of approximately 10 to 80 times, for example, approximately 10 to 60 times, and an average cell size of approximately 50 μm to 300 μm, for example, approximately 70 μm to 250 μm. Within this range, the foamed particles (foamed molded article) may exhibit excellent foaming moldability (fusion properties), mechanical properties, etc. Here, the foaming ratio of the foamed particles can be measured by the direct immersion method. Specifically, the weight and volume of the dried foamed particles are measured using a graduated cylinder and a scale to calculate the particle density, and then the density of the resin composition particles before foaming is calculated to be 0.9 g / cm³. 3 This value is calculated using a standard of 1x. The average cell size is obtained by cooling the foam particles with liquid nitrogen, cutting the cross-section, measuring the diameter (size) of three or more foam particle cells using an SEM (Scanning Electron Microscope), and then calculating the average value.

[0042] A foamed resin composition according to one specific example of the present invention may further contain additives commonly used in foamed resin compositions, to the extent that they do not impede the objectives and effects of the present invention. Examples of such additives include, but are not limited to, antioxidants, light stabilizers, heat stabilizers, flame retardants, colorants, plasticizers, slip agents, and combinations thereof. When using such additives, their content may be approximately 0.001 parts by weight to approximately 40 parts by weight, for example, approximately 0.1 parts by weight to approximately 10 parts by weight, per approximately 100 parts by weight of the polypropylene.

[0043] In one specific example of the present invention, the foamed resin composition can have antibacterial activity values ​​of approximately 2 to approximately 7, for example, approximately 3 to approximately 6.5, when a 5cm x 5cm specimen is inoculated with Staphylococcus aureus and Escherichia coli according to the JIS Z 2801 antibacterial evaluation method, and then cultured for 24 hours at 35°C and RH90%.

[0044] In a specific example, the foaming resin composition may have a foaming ratio of approximately 20 times and an average cell size of approximately 80 μm to approximately 200 μm, for example, approximately 90 μm to approximately 150 μm.

[0045] A foamed resin composition according to one specific example of the present invention can be produced by known methods for producing foamed particles. For example, the resin composition can be mixed with a dispersion medium containing water and a dispersant to produce a mixture; and a foaming agent can be added to the mixture and foamed to have the foaming ratio and the average size of the cells.

[0046] In specific examples, the dispersant may include one or more of the following: higher fatty acids, higher fatty acid esters, and higher fatty acid amides.

[0047] In specific examples, the resin composition can be added to a reactor containing a dispersion medium, or the dispersion medium can be added to the reactor together with the resin composition to form a mixture.

[0048] In specific examples, the foaming agent can be a foaming agent commonly used for foaming particles, such as carbon dioxide, propane, butane, hexane, pentane, heptane, cyclobutane, cyclohexane, methyl chloride, ethyl chloride, methylene chloride, dimethyl ether, diethyl ether, methyl ethyl ether, nitrogen, argon, etc., which can be used individually or in combination of two or more.

[0049] In a specific example, the foaming occurs when the mixture containing the foaming agent is heated to a temperature of approximately 130°C to 160°C, for example, approximately 135°C to 155°C, and at a pressure of approximately 20 kgf / cm². 2 ~Approx. 50kgf / cm 2 For example, approximately 30 kgf / cm² 2 ~approximately 40 kgf / cm² 2 The process can be carried out by heating and pressurizing to achieve the specified pressure conditions, followed by exposure to room temperature and atmospheric pressure conditions. Under these temperature and pressure conditions, foamed particles (foamable resin composition) with a foaming ratio of approximately 10 to 80 times and an average cell size of approximately 50 μm to 300 μm can be obtained.

[0050] In a specific example, the foamed particles (foamable resin composition) may have an average particle size of approximately 1 mm to 7 mm, for example, approximately 2 mm to 6 mm, as measured by a vernier caliper, but are not limited to this. Within this range, excellent foam moldability and other properties can be obtained.

[0051] The foamed molded article according to the present invention can be formed by filling a mold with the foamable resin composition (foamed particles) and fusing them together, and can be easily manufactured by a person with ordinary skill in the art to which the present invention belongs. For example, the foamed molded article can be manufactured by filling (introducing) the foamed particles into a non-sealed mold, supplying saturated steam (for example, saturated steam at a pressure of about 2.0 bar to about 3.5 bar) to the mold for about 30 seconds to fuse the foamed particles together, and then drying it. Because the foamed molded article has excellent antibacterial properties and mechanical properties, it is useful for aquaculture buoys, hydroponic seedling beds, packaging materials, and cooling materials for transport boxes.

[0052] Furthermore, the foamed resin composition can be used alone in the form of foamed particles without molding, and because it has excellent antibacterial properties, it is also useful as a filling for sofas and cushions in the form of particles.

[0053] [Modes for carrying out the invention] The present invention will be described in more detail below through examples, but such examples are for illustrative purposes only and should not be construed as limiting the present invention.

[0054] Examples The specifications of each component used in the examples and comparative examples are as follows:

[0055] (A) Polypropylene Propylene-ethylene random copolymer (manufacturer: Lotte Chemical, product name: SEP-550) was used.

[0056] (B) Zinc oxide (B1) The average particle size is 150 nm and the specific surface area BET is 10 m². 2Zinc oxide (manufacturer: Taekyung SBC, product name: KS1(F)) was used at a concentration of / g.

[0057] (B2) Average particle size is 30 nm, and specific surface area BET is 40 m². 2 Zinc oxide (manufacturer: Taekyung SBC, product name: ZINIKA-30N) was used at a concentration of / g.

[0058] (B3) The average particle diameter is 750 nm and the specific surface area BET is 5 m². 2 Zinc oxide (manufacturer: Taekyung SBC, product name: KS1) was used at a concentration of / g.

[0059] (C) Faliphatic alcohols 1-Octadecanol (Manufacturer: Merck, Product Name: Stearyl Alcohol) was used.

[0060] (D) Surfactants Glyceryl monostearate (manufacturer: Merck) was used.

[0061] Examples 1-6 and Comparative Examples 1-8 After adding each of the aforementioned components in the amounts listed in Tables 1 and 2 below, the resin composition (1.2 mg, Φ0.8 mm × 1.1 mm pellet form) was produced by extrusion at 220°C. A single-screw extruder with an L / D ratio of 34 and a diameter of 40 mm (screw rotation speed: 700 rpm) was used for extrusion.

[0062] Next, 100 parts by weight of the resin composition was placed in an autoclave together with 300 parts by weight of a dispersion medium (water to which a dispersant had been added). After adding carbon dioxide (CO2), which is a foaming agent, to the autoclave, the temperature and pressure inside the autoclave were changed to 147°C and 40 kg / cm² while stirring. 2The temperature was adjusted accordingly. Next, the contents of the autoclave were exposed to the atmosphere to produce foamed particles (foaming resin composition, foaming ratio approximately 20 times). After drying the foamed particles at room temperature for 24 hours, they were placed in a pressure tank and pressurized to 3 bar at atmospheric pressure (1 bar) for 10 hours, and then filled into a mold (450 mm × 450 mm × 50 mm). Subsequently, saturated steam at 2.5 bar was supplied to the mold for 30 seconds to fuse the foamed particles together, and after cooling and removal, the foamed molded body was dried in a 70°C convection oven for 12 hours to produce a foamed molded body. The physical properties of the produced foamed molded body were evaluated using the following method, and the results are shown in Table 1 below.

[0063] Physical property determination methods (1) Average cell size of foamed particles: After cooling a sample of foamed particles (foamed resin composition) that had been foamed to a foaming ratio of approximately 20 times with liquid nitrogen, the cross section was cut, 10 cells were selected, and the diameter (size) of each cell was measured using an SEM (Scanning Electron Microscope). The average value of the cell diameters (average size, unit: μm) was then calculated.

[0064] (2) Antimicrobial activity value: According to the JIS Z 2801 antimicrobial evaluation method, Staphylococcus aureus and Escherichia coli were inoculated into injection-molded test pieces measuring 5 cm x 5 cm, incubated at 35°C and RH 90% for 24 hours, and then the antimicrobial activity value was measured.

[0065] (3) Evaluation of fusion properties: After bending and crushing the molded articles produced according to the examples and comparative examples, the fusion properties of each foam were evaluated based on the form observed by photographing the cross-section with a microscope. Specifically, if the foam was observed to have torn or cracked on the crushed surface of the molded article, it was judged to have good fusion properties, and if the surface of the foam was observed to be exposed on the crushed surface, it was judged to have poor fusion properties.

[0066] [Table 1]

[0067] [Table 2]

[0068] From the results described above, it can be seen that the foamed resin composition of the present invention is excellent in all aspects, including antibacterial properties, foaming properties, and foam moldability (fusion properties, etc.), and that the quality of the cells of the foamed resin composition (foamed particles) is excellent.

[0069] On the other hand, Comparative Example 1, which used a small amount of zinc oxide, showed a decrease in antibacterial properties, etc. Comparative Example 2, which used an excessive amount of zinc oxide, showed a decrease in foaming properties, fusion properties, etc. Comparative Example 3, which used zinc oxide (B2) instead of the zinc oxide of the present invention, showed that foaming did not occur smoothly, and Comparative Example 4, which used zinc oxide (B3), showed a decrease in antibacterial properties, etc. Furthermore, Comparative Example 5, which used a small amount of aliphatic alcohol, showed a decrease in antibacterial properties, etc. Comparative Example 6, which used an excessive amount of aliphatic alcohol, showed a decrease in antibacterial properties, fusion properties, etc. Comparative Example 7, which used a small amount of surfactant, showed a decrease in antibacterial properties, etc. Comparative Example 8, which used an excessive amount of surfactant, showed a decrease in antibacterial properties, fusion properties, etc.

[0070] The present invention has been described above, primarily focusing on embodiments. Those with ordinary skill in the art to which the present invention pertains should understand that the present invention can be embodied in modified forms that do not deviate from its essential characteristics. Therefore, the disclosed embodiments should be considered from an explanatory perspective, not a restrictive one. The scope of the present invention is expressed in the claims, not in the foregoing description, and all differences within an equivalent scope should be interpreted as being included within the scope of the present invention.

Claims

1. 100 parts by weight of polypropylene; The average particle size is 100 nm to 300 nm, and the specific surface area BET is 5 m². ２ / g to 15m ２ 0.1 to 4 parts by weight of zinc oxide per gram; Aliphatic alcohol 0.08 to 2.5 parts by weight; and A foaming resin composition characterized by containing 0.08 to 2.5 parts by weight of a surfactant.

2. The foamed resin composition according to claim 1, characterized in that the polypropylene comprises one or more of a propylene homopolymer, a propylene-ethylene random copolymer, and an ethylene-propylene copolymer.

3. The foaming resin composition according to claim 1, characterized in that the aliphatic alcohol is an aliphatic alcohol having 6 to 22 carbon atoms.

4. The foaming resin composition according to claim 1, characterized in that the surfactant comprises one or more of glyceryl monostearate, polyethylene glycol, polyoxyethylene alkyl ether, and polyoxyethylene alkylamine.

5. The foaming resin composition according to claim 1, characterized in that the weight ratio of zinc oxide to the surfactant is 1:0.09 to 1:2.

5.

6. The foaming resin composition according to claim 1, characterized in that the weight ratio of the aliphatic alcohol and the surfactant is 1:0.1 to 1:

10.

7. The foamed resin composition according to claim 1, characterized in that the foamed resin composition is in the form of foamed particles produced by foaming a resin composition containing polypropylene, zinc oxide, aliphatic alcohol, and surfactant at a foaming ratio of 10 to 80 times and with an average cell size of 50 μm to 300 μm.

8. The foamed resin composition according to claim 1, characterized in that, according to the JIS Z 2801 antimicrobial evaluation method, the antimicrobial activity values ​​measured after inoculating a 5 cm x 5 cm specimen with Staphylococcus aureus and Escherichia coli, and culturing it for 24 hours at 35°C and 90% RH are 2 to 7, respectively.

9. The foaming resin composition according to claim 1, characterized in that the foaming resin composition has a foaming ratio of 20 times and an average cell size of 80 μm to 200 μm.

10. 100 parts by weight of polypropylene, with an average particle size of 100 nm to 300 nm and a specific surface area BET of 5 m². ２ / g to 15m ２ A resin composition comprising 0.1 to 4 parts by weight of zinc oxide per gram; 0.08 to 2.5 parts by weight of an aliphatic alcohol; and 0.08 to 2.5 parts by weight of a surfactant is mixed with a dispersion medium containing water and a dispersant to produce a mixture; and A method for producing a foamed resin composition, characterized by including the step of adding a foaming agent to the mixture and foaming it so that the foaming ratio is 10 to 80 times and the average cell size is 50 μm to 300 μm.

11. The foaming is performed by heating the mixture containing the foaming agent at a temperature of 130°C to 160°C and at a flow rate of 20 kgf / cm². ２ ~50 kgf / cm² ２ A method for producing a foamed resin composition according to claim 10, characterized by heating and pressurizing to achieve the specified pressure conditions, and then exposing it to room temperature and atmospheric pressure conditions.

12. A foamed molded article formed from the foamed resin composition according to any one of claims 1 to 9.

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