Resin molded products and structures

Abstract

The present invention provides a thermoplastic resin molded article, which is made by blending inorganic fillers such as regolith into a thermoplastic resin, and which is free from warping, has excellent mechanical strength such as fracture stress and self-supporting (rigidity), and when used as a building material for structures, can be used to construct large, column-free structures, and a structure using this resin molded article. [Solution] A resin molded article comprising a thermoplastic resin (A) and an inorganic filler (B), wherein the true density under lunar conditions is 0.001 g / cm³. 3 More than 1.0g / cm 3 The following resin molded product. A structure containing this resin molded product.

Description

[Technical Field]

[0001] This invention relates to a resin molded article containing a thermoplastic resin and an inorganic filler. More specifically, it relates to a thermoplastic resin molded article that suppresses warping through the formulation of an inorganic filler, enabling the construction of a column-free, self-supporting structure. The present invention also relates to a structure using this resin molded body. [Background technology]

[0002] Conventionally, numerous techniques have been studied to increase the mechanical strength of thermoplastic resins by incorporating inorganic fillers. For example, Patent Document 1 proposes a polycarbonate resin composition in which an inorganic filler is blended with the polycarbonate resin to improve rigidity and other properties.

[0003] On the other hand, in recent years, space development programs have been actively pursued, and research is also progressing on the effective utilization of lunar resources. For example, Patent Document 2 proposes a method for manufacturing building materials, in which regolith is kneaded with a curable resin, the mixture of regolith and curable resin is poured into a mold and cured in a lunar environment, then a photosensitive resin is applied to the surface, and the photosensitive resin is cured by irradiating it with light in a lunar environment to form block-shaped building materials.

[0004] Regolith is sediment deposited on the lunar surface, consisting of aggregates of particles with a median particle size of 70 μm and a maximum particle size of approximately 2 mm. Its composition has been determined from samples brought back by Apollo 11 and other missions, and as shown in Table 1 below, it contains a higher proportion of iron oxide, calcium oxide, magnesium oxide, and titanium oxide compared to minerals on Earth. Furthermore, a regolith simulant (a simulated lunar surface soil) has been developed using Earth's mineral resources based on the composition of regolith, and as shown in Table 1 below, it contains slightly less than 5% iron(III) oxide (Fe2O3), which is not found in regolith.

[0005] [Table 1] [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-187863 [Patent Document 2] Japanese Patent Application Publication No. 5-139866 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As mentioned above, while blends of thermosetting resins and regolith have been proposed, no consideration has been given to blends of thermoplastic resins and regolith.

[0008] Thermosetting resins have advantages over thermoplastic resins in terms of heat resistance, mechanical strength, and chemical resistance, but they also have disadvantages such as inferior toughness, a long molding time, a large number of molding steps, difficulty in obtaining molded products with complex shapes, and high molding costs. Therefore, from the standpoint of industrial practical application, the inventors conceived of using a thermoplastic resin with an inorganic filler such as regolith, rather than a thermosetting resin, to create a building material. Furthermore, when such a thermoplastic resin molded body is used as a building material for structures, especially for structures on the lunar surface or structures on the lunar surface (lunar structures), it is desirable that it be free from warping, have excellent mechanical strength such as fracture stress and self-supporting ability (rigidity), and enable the construction of large, column-free structures.

[0009] The present invention aims to provide a thermoplastic resin molded article, which is a thermoplastic resin molded article obtained by blending an inorganic filler such as regolith into a thermoplastic resin, and which is free from warping, has excellent mechanical strength such as fracture stress and self-supporting (rigidity), and is particularly useful as a building material for structures on the lunar surface, enabling the construction of large, column-free structures. The present invention also aims to provide a structure using this resin molded article. [Means for solving the problem]

[0010] As a result of repeated studies to solve the above problems, the inventors have found that the above problems can be solved by controlling the true density of a thermoplastic resin molded body containing an inorganic filler within a specific range in the lunar environment. That is, the gist of the present invention is as follows.

[0011] [1] A resin molded body containing a thermoplastic resin (A) and an inorganic filler (B), having a true density in the lunar environment of 0.001 g / cm , ,

[0018] , , , ,

[0017] or more and 1.0 g / cm 3 or less.

[0012] [2] The resin molded body according to [1], wherein the true density is 0.005 g / cm 3 or more and 0.5 g / cm 3 or less.

[0013] [3] The resin molded body according to [1] or [2], having a plate-like portion with a thickness of 10 cm or more and 200 cm or less.

[0014] [4] The resin molded body according to any one of [1] to [3], wherein the thermoplastic resin (A) is a polycarbonate-based resin.

[0015] [5] The resin molded body according to any one of [1] to [3], wherein the thermoplastic resin (A) is a polyvinyl alcohol-based resin.

[0016] [6] The resin molded body according to [5], wherein the polyvinyl alcohol-based resin is an ethylene-vinyl alcohol copolymer.

[0017] <​​​​​​

[0019] [9] The resin molded article according to [7] or [8], wherein the SiO2 content is 20 to 60% by mass relative to the total amount of the inorganic filler (B).

[0020]

[10] The resin molded article according to any one of [7] to [9], wherein the inorganic filler (B) further comprises Al2O3.

[0021]

[11] The resin molded article according to

[10] , wherein the content of Al2O3 is 10 to 50% by mass relative to the total amount of the inorganic filler (B).

[0022]

[12] The resin molded article according to any one of [1] to

[11] , wherein the inorganic filler (B) is regolith.

[0023]

[13] A lunar surface structure made of a resin molded body as described in any of [1] to

[12] .

[0024]

[14] A structure containing a resin molded body as described in any of [1] to

[12] . [Effects of the Invention]

[0025] The resin molded article of the present invention is a thermoplastic resin molded article obtained by blending an inorganic filler such as regolith into a thermoplastic resin, and is free from warping, has excellent mechanical strength such as fracture stress, and also has excellent self-supporting properties (rigidity). Therefore, by using the resin molded body of the present invention as a building material for structures, particularly for structures on the lunar surface, it is possible to construct large, column-free structures. [Brief explanation of the drawing]

[0026] [Figure 1] Figure 1 is a schematic diagram showing the structure of a building modeled for the purpose of evaluating its self-supporting nature in the embodiment. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following description and can be modified and implemented as appropriate without departing from the spirit of the invention. Furthermore, in this specification, when "~" is used to enclose numerical values ​​or physical properties, it shall be used to include the values ​​before and after it. Furthermore, in this specification, “mass%” and “parts by mass” are synonymous with “weight%” and “parts by weight.”

[0028] [Resin molded product] The present invention relates to a resin molded article comprising a thermoplastic resin (A) and an inorganic filler (B), wherein the true density under lunar conditions is 0.001 g / cm³. 3 More than 1.0g / cm 3 The following characteristics apply:

[0029] In the present invention, the true density of a resin molded article is the value obtained by dividing the mass (weight) of the resin molded article by the volume of the resin molded article with or without voids. However, for convenience, the true density of the pellets of the resin composition used to mold the resin molded article can be used as a substitute. The true density of the pellets of the resin composition can be determined by dividing the mass (weight) of the pellets by the volume of the pellets, and can be measured using a conventionally known dry density measurement method (23°C).

[0030] A key feature of this invention is that, as the true density of the resin molded article, it is specifically defined as "true density under lunar conditions." As described later, since gravity on the lunar surface is approximately 1 / 6 of gravity on Earth, the "true density under lunar conditions" according to this invention can be calculated by reducing the true density on Earth to 1 / 6. In the following, "true density under lunar conditions" will be referred to as "lunar density," and "true density on Earth" will be referred to as "Earth density."

[0031] Furthermore, in the following, a resin composition comprising a thermoplastic resin (A) and an inorganic filler (B) used for molding the resin molded article of the present invention will be referred to as "the resin composition of the present invention."

[0032] <Mechanism of the resin molded body in the lunar density> The inventors have repeatedly studied a resin molded body containing a thermoplastic resin (A) and an inorganic filler (B) such as wollastonite, and as a result of repeatedly studying the mechanical strength such as breaking stress and self-supporting property (rigidity) and warpage suppression required in the use as a building material, particularly a building material used on the lunar surface, it has been found that the lunar density of the resin molded body is an important requirement, and by controlling the lunar density within a predetermined range, a resin molded body excellent in mechanical strength such as breaking stress and self-supporting property (rigidity) and free from the problem of warpage can be obtained. That is, for example, as the use of a resin molded body using wollastonite as the inorganic filler (B), it is considered that the use as a building material for a building on the lunar surface is optimal. However, since the gravity on the lunar surface is 1 / 6 of the gravity on the earth, the density of the resin molded body on the lunar surface also becomes a lunar-specific density of 1 / 6 of the earth density. The inventors have determined the lunar density of a resin molded body that has no warpage, is excellent in self-discipline, and can construct a large building without columns at such a lunar-specific density, and the lunar density is 0.001 g / cm 3 Up to 1.0 g / cm 3 If it is below, it has been found that a resin molded body that meets this purpose can be obtained. In addition, conventionally, no study has been made on the regulation of the lunar density of a resin molded body considering such gravity on the lunar surface, and this is the first study by the inventors.

[0033] The lunar density of the resin molded body is 0.001 g / cm 3 Less than this is a value that cannot be realized unless a large amount of voids are included, so the strength as a building structure cannot be maintained. On the other hand, if the true density exceeds 1.0 g / cm 3 For example, in the case of a ceiling material, its own weight becomes large, so it is difficult to construct a large building without columns. From this point of view, the lunar density of the resin molded body of the present invention is preferably 0.005 g / cm 3 or more and 0.5 g / cm 3 or less, and preferably 0.1 g / cm 3 or more and 0.4 g / cm 3The following is more preferable:

[0034] To achieve the above range for the lunar surface density of the resin molded article of the present invention, for example, the specific gravity of the thermoplastic resin (A) should be 0.8 to 2.2 g / cm³. 3 Use an inorganic filler (B) with a specific gravity of 1.3 to 5.0 g / cm³. 3 Using materials such as; setting the ratio of inorganic filler (B) to thermoplastic resin (A) to 20-50% by mass; and employing such methods, the Earth density is 0.005-0.5 g / cm³. 3 Especially 0.01~0.45 g / cm³ 3 In particular, 0.1-0.4 g / cm³ 3 It can be made into a resin molded body.

[0035] <Inventive Resin Composition> The following describes the resin composition of the present invention, which comprises a thermoplastic resin (A) and an inorganic filler (B), and is a constituent material of the resin molded article of the present invention.

[0036] (Thermoplastic resin (A)) There are no particular restrictions on the thermoplastic resin (A), and examples of usable materials include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, polyurethane resin, styrene-acrylonitrile copolymer (AS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylic resin, polyamide resin (nylon 6, nylon 66, etc.), polyacetal resin, polycarbonate resin, polyester resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene ether resin, polyetherimide resin, fluororesin, etc. These may be used individually, or two or more may be mixed in any combination and ratio.

[0037] Of these thermoplastic resins, it is preferable to use a polycarbonate-based resin, and in particular an aromatic polycarbonate-based resin, as the thermoplastic resin (A) used in the present invention from the viewpoint of heat resistance.

[0038] The polycarbonate resin used as thermoplastic resin (A) is selected based on its stability during molding and the toughness and heat resistance of the resulting molded resin. The melt volume flow rate (MVR), measured at 300°C and a 2160 gkgf load in accordance with ISO 1133, is between 1 and 50 cm³. 3 At 10 minutes, the density (earth's density) measured in accordance with ISO 1183 is 1.1-1.6 g / cm³. 3 Those within the specified range are preferred. If the MVR of polycarbonate resin is above the lower limit, it tends to have an appropriate viscosity and excellent melt extrusion properties, and if it is below the upper limit, it tends to have excellent stability during molding. From this perspective, the MVR of polycarbonate resin should be between 3 and 15 cm. 3 A time of 10 minutes is more preferable. Furthermore, if the density of the polycarbonate resin is above the lower limit mentioned above, the resulting molded resin tends to have excellent flexibility and heat resistance, while if it is below the upper limit, the resulting molded resin tends to have excellent toughness. From this perspective, the density of the polycarbonate resin is 1.15 to 1.3 g / cm³. 3 It is preferable that it be so.

[0039] Polycarbonate resins may be used individually, or two or more types with different monomer compositions and physical properties may be mixed and used.

[0040] Furthermore, as the thermoplastic resin (A), it is preferable to use a polyvinyl alcohol-based resin from the viewpoint of having excellent affinity with regolith and obtaining a good dispersion state.

[0041] Examples of polyvinyl alcohol-based resins to be used include polyvinyl alcohol resin, modified polyvinyl alcohol resin obtained by modifying polyvinyl alcohol resin, ethylene-vinyl alcohol copolymer, and modified ethylene-vinyl alcohol copolymer obtained by further modifying ethylene-vinyl alcohol copolymer. These polyvinyl alcohol-based resins may be used individually or in combination of two or more types.

[0042] Polyvinyl alcohol resin can be obtained by saponifying the acetate group of polyvinyl acetate, which is a polymer of vinyl acetate. Examples of modified polyvinyl alcohol resins include butenediol-modified, silanol-modified, or acetoacetyl-modified polyvinyl alcohol resins.

[0043] The content of ethylene structural units in the ethylene-vinyl alcohol copolymer is preferably 20 to 60 mol%, more preferably 25 to 50 mol%, and particularly preferably 25 to 35 mol%. When the content is above the lower limit, the product tends to exhibit excellent gas barrier properties and melt moldability under high humidity conditions. On the other hand, when the content is below the upper limit, the product tends to exhibit excellent gas barrier properties. In this embodiment, the content ratio of ethylene structural units in the ethylene-vinyl alcohol copolymer is as follows: 1 It can be measured by 1H-NMR.

[0044] The degree of saponification of the ethylene-vinyl alcohol copolymer is preferably 90 to 100 mol%, more preferably 95 to 100 mol%, and even more preferably 99 to 100 mol%. When the degree of saponification is above the lower limit, it tends to exhibit excellent gas barrier properties, thermal stability, moisture resistance, etc. The degree of saponification of such ethylene-vinyl alcohol copolymer is, 1 It can be measured by 1H-NMR.

[0045] The melt flow rate (MFR) (210°C, 2160g load) of the ethylene-vinyl alcohol copolymer is preferably 0.5 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, and even more preferably 3 to 35 g / 10 min. When the MFR is below the upper limit, the material tends to have excellent stability during molding, and when it is above the lower limit, it tends to have an appropriate viscosity and excellent melt extrudeability. The aforementioned MFR is an indicator of the degree of polymerization of the ethylene-vinyl alcohol copolymer, and can be adjusted by the amount of polymerization initiator and solvent used when copolymerizing ethylene and vinyl ester.

[0046] Polyvinyl alcohol-based resins, such as ethylene-vinyl alcohol copolymers, typically have a density (density on Earth) of 1.05 to 1.30 g / cm³ as measured by the dry density method (23°C). 3 Particularly preferred is 1.14 to 1.21 g / cm³. 3 The MFR (Melting Frequency Rating) measured by a melt indexer (at 210°C, 2160g load) is typically 1 to 50g / 10 min, particularly preferably 3 to 12g / 10 min, and the melting point measured by DSC method at a heating and cooling rate of 10°C / min is typically 120 to 210°C, particularly preferably 140 to 185°C. If the density of the polyvinyl alcohol-based resin, such as ethylene-vinyl alcohol copolymer, is above the lower limit, the resulting resin molded article tends to have excellent flexibility and heat resistance. If the density is below the upper limit, the resulting resin molded article tends to have excellent toughness and a suitable melting point, making it easy to melt mold. If the MFR of a polyvinyl alcohol-based resin such as an ethylene-vinyl alcohol copolymer is above the lower limit, the resin itself tends to have excellent fluidity and is easy to mix with inorganic filler (B). If it is below the upper limit, it tends to have excellent heat resistance and the resulting resin molded article tends to have excellent strength. If the melting point of a polyvinyl alcohol-based resin, such as an ethylene-vinyl alcohol copolymer, is above the lower limit, it exhibits excellent heat resistance, and the resulting molded resin tends to have excellent strength. If the melting point is below the upper limit, the resulting molded resin tends to have excellent toughness and is easy to melt mold.

[0047] Polyvinyl alcohol-based resins such as ethylene-vinyl alcohol copolymers may be used alone, or two or more resins with different resin types, modification status, and physical properties may be mixed and used.

[0048] (Inorganic filler (B)) The inorganic filler (B) used in the present invention is preferably one containing SiO2 from the viewpoint of obtaining a resin molded article with excellent mechanical strength and light weight, and is even more preferably one containing Al2O3 from the viewpoint of compatibility with thermoplastic resin (A) and uniform dispersion.

[0049] As the inorganic filler (B), two or more different inorganic fillers (B) may be mixed and used, but the SiO2 content is preferably 20 to 60% by mass, and more preferably 40 to 60% by mass, relative to the total amount of inorganic filler (B). If the SiO2 content is above the lower limit, the compatibility with thermoplastic resin (A) tends to be excellent, and if it is below the upper limit, the resulting resin molded article tends to have excellent brittleness and is less prone to becoming brittle.

[0050] Furthermore, the Al2O3 content relative to the total amount of inorganic filler (B) is preferably 10 to 50% by mass, and more preferably 20 to 30% by mass. If the Al2O3 content is above the lower limit, the compatibility with thermoplastic resin (A) tends to be excellent, and if it is below the upper limit, the resulting resin molded article tends to have excellent brittleness and is less prone to becoming brittle.

[0051] Examples of such inorganic fillers (B) include red clay, acidic clay, and basalt, but in the present invention, it is preferable to use regolith from the viewpoint of effective utilization of lunar resources. In this invention, regolith refers to a broader term encompassing not only lunar soil but also lunar soil simulants (regolith-like products) such as the aforementioned regolith simulant.

[0052] In the present invention, the inorganic filler (B) may be one of the inorganic fillers described above, or two or more may be mixed, as long as the preferred SiO2 and Al2O3 content ratios described above are met. From the perspective of utilizing lunar resources, it is preferable that the inorganic filler (B) contains 30% by mass or more, and particularly 50-100% by mass, of regolith.

[0053] (Percentage of inorganic filler (B) content) The content ratio of inorganic filler (B) in the resin composition of the present invention is the same as the content ratio of inorganic filler (B) in the resin molded article of the present invention. In the resin molded article and resin composition of the present invention, the content of inorganic filler (B) is preferably 10% by mass or more of the total amount of the resin molded article and resin composition in order to effectively obtain mechanical strength such as fracture stress, self-supporting (rigidity), and anti-warping effects due to the incorporation of inorganic filler (B). On the other hand, the content of inorganic filler (B) in the resin molded article and resin composition of the present invention is preferably 50% by mass or less of the total amount of the resin molded article and resin composition in order to suppress the decrease in elongation at break due to the incorporation of inorganic filler (B), increase mechanical strength such as breaking stress, and obtain a practical resin molded article. From the viewpoint of balancing the suppression of the decrease in elongation at break with the improvement of mechanical strength such as fracture stress, the content of inorganic filler (B) is more preferably 20 to 50% by mass, and particularly preferably 30 to 40% by mass, relative to the total amount of the resin molded article and resin composition.

[0054] (Other ingredients) The resin composition of the present invention may contain other components besides the thermoplastic resin (A) and inorganic filler (B), as long as they do not impair the purpose of the present invention. Other components that the resin composition of the present invention may contain include plasticizers (such as triacetin), lubricants, antistatic agents, antioxidants, light stabilizers, ultraviolet absorbers, dyes, pigments, hydrolysis inhibitors, nucleating agents, antiblocking agents, lightfastness agents, heat stabilizers, flame retardants, mold release agents, antifogging agents, surface wetting improvers, dispersion aids, various surfactants, slip agents, and other additives, as well as fillers other than inorganic filler (B). These can be arbitrarily blended as long as they do not impair the effects of the present invention, and one type may be used alone, or two or more types may be used in combination.

[0055] The content of these other components is usually preferably such that the total amount of components mixed is 30% by mass or less, for example, 0.05 to 20% by mass, relative to the total amount of the resin composition of the present invention, in order not to impair the physical properties of the resin composition of the present invention.

[0056] (Method for manufacturing resin compositions) The resin composition of the present invention is produced by mixing a thermoplastic resin (A) and an inorganic filler (B) with other components as needed.

[0057] This mixing process involves mixing the thermoplastic resin (A) and inorganic filler (B), along with other components as needed, simultaneously or in any order in predetermined proportions using a mixer such as a tumbler, V-type blender, Nauter mixer, Banbury mixer, kneading roll, or extruder, preferably by melt kneading. While either a twin-screw extruder or a single-screw extruder may be used, a twin-screw extruder is more preferable for achieving good melt kneading depending on the properties of the thermoplastic resin (A) and inorganic filler (B).

[0058] The temperature during melt mixing is preferably 150 to 230°C, and more preferably 190 to 220°C. Within this temperature range, the time required for the melt reaction can be shortened, deterioration of color due to resin degradation can be prevented, and the physical properties in practical applications can be further improved. Furthermore, regarding the melting and kneading time, from the viewpoint of more reliably avoiding resin degradation as described above, unnecessary lengthening should be avoided. Preferably, it should be 20 seconds to 15 minutes, and more preferably 30 seconds to 10 minutes. It is preferable to set the melting and kneading temperature and time conditions to satisfy this.

[0059] <Method for molding resin molded products> The resin molded articles of the present invention are obtained by molding the resin composition of the present invention. Examples of molding methods include compression molding (compression molding, lamination molding, stampable molding), injection molding, extrusion molding and co-extrusion molding (film molding, lamination molding, pipe molding, wire / cable molding, profile molding by inflation method and T-die method), hot press molding, hollow molding (various blow molding), calendering, solid molding (uniaxial stretching, biaxial stretching, roll rolling, stretch-oriented nonwoven fabric molding, thermoforming (vacuum forming, pressure forming), plastic processing, powder molding (rotational molding), and various nonwoven fabric molding (dry method, adhesive method, entanglement method, spunbond method, etc.). In particular, injection molding, extrusion molding, compression molding, or hot press molding are preferred methods. Specific shapes of molded articles include plate-like, sheet-like, film-like, pellet-like, fibrous, hollow cylindrical, and various injection-molded shapes.

[0060] Furthermore, the resin molded articles of the present invention, which are formed by molding the resin composition of the present invention, can be subjected to various secondary processing for the purpose of imparting surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, and thermal functions. Examples of secondary processing include embossing, painting, bonding, printing, metallizing (plating, etc.), machining, and surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.).

[0061] The resin molded articles of the present invention, comprising the resin composition of the present invention, are applicable to various fields such as building materials, automotive interior materials, furniture, and various enclosures. In particular, they are useful for building material applications due to their excellent mechanical strength, such as fracture stress, and warp suppression. Among these, they are particularly useful as building materials or lunar structures used on the lunar surface, from the viewpoint of effective utilization of regolith. As lunar structures, they may be block-shaped building materials or used as building materials.

[0062] Building materials using the resin molded articles of the present invention can be applied to various parts of a house or facility on the lunar surface, such as walls, ceilings, floors, doors, antennas, and spacecraft docks.

[0063] <Shape of the resin molded product> There are no particular restrictions on the shape of the resin molded article of the present invention. As mentioned above, the resin molded article of the present invention can be molded into various shapes. However, particularly for applications such as building materials, it is preferable that the article has a plate-like portion with a thickness of 10 cm to 200 cm, as this effectively improves the mechanical strength, such as fracture stress, and self-supporting (rigidity) of the resin molded article of the present invention, as well as the effect of preventing warping, and is applicable to various uses. In this context, the plate-like portion is not necessarily limited to a flat plate; it may also be curved or have partial steps.

[0064] If the thickness of this plate-like section is 10 cm or more, it will have sufficient strength to construct large, column-free structures without warping, and if it is 200 cm or less, it will allow for the construction of structures with a highly flexible appearance. From this viewpoint, the thickness of the plate-like portion according to the present invention is preferably 10 to 200 cm, and particularly preferably 15 to 150 cm.

[0065] Typical shapes of the resin molded articles of the present invention having such plate-like portions include plate-like bodies with a thickness of 10 to 200 cm, particularly 15 to 150 cm, and especially 20 to 100 cm, with a length of 300 to 1200 m and a width of 300 to 1200 m, and such plate-like bodies are formed using the resin molded article molding method described above.

[0066] [Building] The structure of the present invention is constructed using the resin molded body of the present invention as a building material, and there are no particular restrictions on its shape. However, the structure of the present invention, like the resin molded body of the present invention, is particularly suitable as a structure on the lunar surface, and due to its excellent self-supporting properties, for example, with a wall thickness of 10 to 200 cm and a volume (volume of external dimensions) of 2.6 × 10 7 ~1.5×10 9 m 3 Even for structures of a certain size, it is possible to create a column-free structure, resulting in excellent constructability. [Examples]

[0067] The specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. The various manufacturing conditions and evaluation result values ​​in the following embodiments represent preferred upper or lower limits in the embodiments of the present invention, and the preferred range may be defined by a combination of the aforementioned upper or lower limits and the values ​​of the following embodiments or between embodiments.

[0068] [Raw materials used] The details of the raw materials used in the following examples and comparative examples are as follows.

[0069] <Thermoplastic resin (A)> Ethylene-vinyl alcohol copolymer: EVOH pellets "Soanol (registered trademark) A4412B" manufactured by Mitsubishi Chemical Corporation (Density: 1.14 g / cm³) 3 MFR = 12.0 g / 10 min (210°C), Melting point: 164°C, Ethylene structural unit content: 44 mol%, Degree of saponification: 99.7 mol%) Polycarbonate resin: PC pellets "XANTAR(registered trademark) 7022J" manufactured by Mitsubishi Chemical Corporation (density: 1.21 g / cm³) 3 MVR=14cm 3 / 10 minutes (300℃))

[0070] <Inorganic filler (B)> Regolith-like product: Tegara Corporation's "LHS-1D" (SiO2 content: 51.2% by mass, Al2O3 content: 26.6% by mass)

[0071] [Examples 1-3] <Preparation of resin composition pellets> A mixture was obtained by dry blending the thermoplastic resin (A) and inorganic filler (B) shown in Table 2 in the proportions shown in Table 2. This mixture was fed into a twin-screw extruder (20 mmφ) equipped with a two-hole die, extruded under the following extrusion conditions (required time 5 minutes), and the extruded strand was cooled and solidified by air cooling. Next, the solidified strands were cut with a pelletizer to obtain pellets of the resin composition. (Extrusion conditions) Extruder setting temperature (℃): C1 / C2 / C3 / C4 / C5 / C6 =200 / 210 / 225 / 225 / 225 / 225

[0072] <Measurement of lunar surface density> For the obtained pellets, the true density of the pellets was measured using a dry automatic densimeter (Micromeristics). The true density of the pellets and the known true density of the regolith simulant were used to calculate the true density of the composite from the ratio of these two components. The lunar surface density of the resin molded body was defined as 1 / 6 of the calculated true density. The results are shown in Table 2.

[0073] <Preparation of resin molded body (1)> Using the prepared pellets, a dumbbell-shaped test specimen (total length 170 mm) with a thickness of 4 mm and a gauge distance of 115 mm was obtained by injection molding at a nozzle temperature of 210°C using an electric injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd.).

[0074] <Measurement of maximum stress (fracture stress)> The obtained resin molded body (1) was subjected to a tensile test using an Autograph AG-IS5kN (manufactured by Shimadzu Corporation) with a chuck distance of 115 mm, in accordance with JIS K7139, at room temperature of 23°C and a speed of 50 mm / min. The maximum stress (fracture stress) was determined from the obtained stress-strain curve. The results are shown in Table 2.

[0075] <Evaluation of whether or not there is warping> A test specimen of resin composition (1) was placed on a horizontal table, and one end of the specimen in the longitudinal direction was pressed against the upper surface of the table. The other end, opposite to the pressed end, was visually observed to see if it lifted off the table and evaluated as follows. The results are shown in Table 2. ○: The other end does not lift up, and there is no warping. ×: The other end is lifted and warped.

[0076] <Evaluation of the self-supporting properties of the resin molded body (2)> From the above-mentioned lunar surface density, deformation, and stress measurement results, the stiffness (K) is calculated. Using the following software, a resin molded body (2) with the shape shown in Figure 1 is modeled assuming a structure on the lunar surface. Under lunar conditions, the load (F) of the resin molded body (1) is multiplied by the reciprocal (inverse matrix) of the stiffness, and the displacement vector (X) of the structure is obtained from the linear elastic equation using the finite element method shown below. The stress generated inside the structure is calculated from the displacement vector (X), and it is determined that if the stress is less than one-tenth of the maximum stress (breaking stress), it is possible to stand independently without columns. The maximum size (volume (external dimensions) and side length) of the resin molded body (2) subjected to one-tenth of the maximum stress (breaking stress) of the resin molded body (1) is investigated with the wall thickness shown in Table 3. The larger this maximum volume (or side length) value, the more capable the structure (building, etc.) is of being self-supporting, indicating superior self-supporting ability. Software used: NASTRAN Linear elasticity equation: X = F / K X: Displacement vector (unknown quantity) F: Load vector K: Stiffness matrix The results are shown in Table 3.

[0077] [Comparative Example 1] Without incorporating regolith, pellets were prepared and evaluated using only the thermoplastic resin (A) shown in Table 2, in the same manner as in Example 1, and the results are shown in Tables 2 and 3.

[0078] [Reference examples 1 and 2] The Earth density of the resin composition pellets produced in Examples 1 and 3 was determined, and the self-supporting properties of the resin molded body (2) on Earth, rather than in the lunar environment, were similarly evaluated. The results are shown in Tables 2 and 3.

[0079] [Table 2]

[0080] [Table 3]

[0081] Tables 2 and 3 show that if a resin molded body containing thermoplastic resin (A) and inorganic filler (B) has a lunar surface density within a predetermined range, there is no problem with warping, and even large structures exhibit excellent self-supporting properties, allowing for the construction of large, column-free structures. In contrast, the resin molded article of Comparative Example 1, which does not contain inorganic filler (B), has a problem of warping. Reference Examples 1 and 2 show the results of evaluations in the global environment. It can be seen that even with the same composition as Examples 1 and 3, the conclusion is that, given the global density, it can only be applied to small structures and cannot be used to construct large, column-free structures. Furthermore, the evaluation results of the self-supporting properties based on the difference in wall thickness in Example 1 show that excessively thick walls limit the size of the structure that can stand on its own.

Claims

1. A resin molded article comprising a thermoplastic resin (A) and an inorganic filler (B), The true density under lunar conditions is 0.001 g / cm³. ３ 1.0g / cm or more ３ The following resin molded products.

2. The true density is 0.005 g / cm³. ３ 0.5g / cm or more ３ The resin molded article according to claim 1, which is as follows:

3. The resin molded body according to claim 1, wherein the thickness of the resin molded body is 10 cm or more and 200 cm or less, and the plate-like portion is also a resin molded body.

4. The resin molded article according to claim 1, wherein the thermoplastic resin (A) is a polycarbonate-based resin.

5. The resin molded article according to claim 1, wherein the thermoplastic resin (A) is a polyvinyl alcohol-based resin.

6. The resin molded article according to claim 5, wherein the polyvinyl alcohol-based resin is an ethylene-vinyl alcohol copolymer.

7. The inorganic filler (B) is SiO ２ A resin molded article according to claim 1, comprising:

8. The resin molded article according to claim 1, wherein the content of the inorganic filler (B) is 10% by mass or more relative to the entire resin molded article.

9. The SiO ２ The resin molded article according to claim 8, wherein the content of is 20 to 60% by mass relative to the total amount of the inorganic filler (B).

10. The inorganic filler (B) is further Al ２ O ３ A resin molded article according to claim 8, including the following:

11. The above-mentioned Al ２ O ３ The resin molded body according to claim 11, wherein the content ratio is 10 to 50% by mass based on the total amount of the inorganic filler (B).

12. The resin molded article according to claim 1, wherein the inorganic filler (B) is regolith.

13. A lunar surface structure comprising a resin molded body according to any one of claims 1 to 12.

14. A structure comprising a resin molded body according to any one of claims 1 to 12.

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