The stem is molded from plastic formulations, civil engineering materials, building materials, gardening materials, and the method of producing molded stems from plastic formulations.
Patent Information
- Application Number
- VN1202601994
- Authority / Receiving Office
- VN · VN
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2026-08-17
Smart Images
Figure VN1202601994_0
Abstract
Description
Resin composition molded body, civil engineering material, building material, gardening material, and method for producing resin composition molded body
[0001] The present disclosure relates to a resin composition molded article, a civil engineering material, a building material, a gardening material, and a method for producing a resin composition molded article.
[0002] Molded resin compositions containing wood flour particles dispersed in a resin (matrix material) are known (see, for example, Patent Document 1). Molded resin compositions containing wood flour particles are also called wood plastics, and while they have a texture similar to wood, they offer advantages such as being less susceptible to corrosion, cracking, and splintering, and being lighter than wood. For this reason, molded resin compositions containing wood flour particles are widely used as building materials and the like. Molded resin compositions containing wood flour particles are generally produced by hot molding a raw material composition containing wood flour particles and a thermoplastic resin. The use of recycled resins separated and recovered from waste as raw materials for thermoplastic resins has been investigated (see, for example, Patent Document 2).
[0003] JP 2015-529582 A JP 2001-353707 A
[0004] Using recycled resin derived from waste as the resin raw material for resin composition molded products promotes resource circulation and reduces CO2 emissions from incineration of waste. ２ This is desirable from the viewpoint of greatly contributing to the reduction of waste emissions. However, recycled resins derived from waste contain various resins. The present inventors have discovered a problem that when recycled resins contain a large amount of high-melting-point resins or thermosetting resins, the water resistance of resin composition molded articles may decrease. Furthermore, they have discovered a problem that when the temperature during heat molding of a resin composition molded article is high, low-molecular-weight components contained in the recycled resin or wood flour volatilize, causing bubbles to form on the surface of the molded article, which may impair the appearance.
[0005] The present disclosure aims to provide a resin composition molded product containing cellulose-based material particles such as wood flour particles, which is less likely to develop bubbles on the surface and exhibits excellent water resistance even when manufactured using recycled resins including high-melting-point resins and thermosetting resins, a method for manufacturing the same, and civil engineering materials, building materials, and gardening materials.
[0006] The present disclosure relates to a molded body of a composition including a resin substrate containing a low-melting-point resin, cellulose-based material particles dispersed in the resin substrate, and non-low-melting-point resin particles dispersed in the resin substrate, wherein the low-melting-point resin has a melting point in the range of 80°C or higher but lower than 190°C, and the content of the low-melting-point resin relative to the total amount of the composition is in the range of 10% by mass or higher and 80% by mass or lower, the cellulose-based material particles include at least wood flour particles, and the content of the cellulose-based material particles relative to the total amount of the composition is in the range of 10% by mass or higher and 50% by mass or lower, and the non-low-melting-point resin particles include one or both of a high-melting-point resin and a thermosetting resin, each having a melting point of 190°C or higher, and the content of the non-low-melting-point resin particles relative to the total amount of the composition is in the range of 10% by mass or higher and 80% by mass or lower.
[0007] 1 is a cross-sectional view of a resin composition molded article according to an embodiment of the present disclosure; 2 is a perspective view of a paving material according to an embodiment of the present disclosure; 3 is a cross-sectional view of a road surface paved using the paving material according to an embodiment of the present disclosure.
[0008]
[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. As shown in Fig. 1, a resin composition molded article 10 of this embodiment is a molded article of a composition including a resin substrate (matrix material) 11, cellulose-based material particles 12 dispersed in the resin substrate 11, and non-low-melting-point resin particles 13 dispersed in the resin substrate 11.
[0009] The resin substrate 11 includes a low-melting-point resin. The low-melting-point resin is a thermoplastic resin having a melting point in the range of 80°C or higher and lower than 190°C. The low-melting-point resin may have a melting point lower than 160°C or higher. Examples of low-melting-point resins having a melting point in the range of 80°C or higher and lower than 160°C include polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), polyethylene (PE), polymethyl methacrylate (PMMA), and polycarbonate (PC). Examples of low-melting-point resins having a melting point in the range of 160°C or higher and lower than 190°C include polypropylene (PP), polyamide 12 (PA12), and polyacetal (POM). The low-melting-point resin may be used alone or in combination of two or more. For example, if the low-melting-point resin is derived from waste and is a mixture of multiple low-melting-point resins, the resins may be separated by type or the mixture may be used as is. When two or more types are used in combination, low-melting-point resins having a melting point of less than 160°C may be combined, low-melting-point resins having a melting point of 160°C or higher may be combined, or a low-melting-point resin having a melting point of less than 160°C may be combined with a low-melting-point resin having a melting point of 160°C or higher. The low-melting-point resin may contain at least polyethylene (PE) and polypropylene (PP). The PE and PP content, in terms of the mass ratio of PE to PP (PE / PP), may be, for example, 1.4 or less, or 1.2 or less.
[0010] The low-melting-point resin may be derived from waste, for example, a low-melting-point resin separated and recovered from waste plastic collected in accordance with the Containers and Packaging Recycling Law.
[0011] The content of the low-melting point resin is in the range of 10% by mass or more and 80% by mass or less relative to the total amount of the resin composition molded product 10. The content of the low-melting point resin may be in the range of 10% by mass or more and 50% by mass or less, in the range of 12% by mass or more and 45% by mass or less, or in the range of 15% by mass or more and 45% by mass or less.
[0012] The particle shape of the cellulose-based material particles 12 dispersed in the resin substrate 11 is not particularly limited and may be, for example, spherical, oval-spherical, cylindrical, prismatic, plate-like, or amorphous. The particle size of the cellulose-based material particles 12 is not particularly limited, but among particles with a major axis of 1.0 mm or more, the content of particles with a major axis of 3.0 mm or more may be 35% by number or less, or 20% by number or less. Furthermore, the content of particles with a major axis of less than 2.0 mm may be 30% by number or more, or 50% by number or less. The content of these particles can be determined by observing a cross section of the resin composition molded product 10 using an optical microscope and measuring the particle diameter of the cellulose-based material particles 12.
[0013] The content of the cellulose-based material particles 12 having a major axis of 5.0 mm or more is 1.0 particle / 100 mm as the average content contained in a 10 mm x 10 mm cross-sectional area of the resin composition molded body 10. ２ It may be less than 0.5 pieces / 100 mm ２ The average content of the cellulose-based material particles 12 can be determined, for example, by dividing the cross section of the resin composition molded body 10 into 10 mm x 10 mm regions and measuring the particle diameters of the cellulose-based material particles present in 1,000 of the divided regions using an optical microscope.
[0014] The cellulose-based material particles 12 may be those that have passed through a sieve with a mesh size of 3 mm. The cellulose-based material particles 12 may be those that have passed through a sieve with a mesh size of less than 3 mm. Examples of sieves with a mesh size of less than 3 mm include sieves with a mesh size of 1 mm and sieves with a mesh size of 2 mm.
[0015] The cellulose-based material particles 12 contain at least wood flour particles. The cellulose-based material particles 12 may contain pulp particles as particles other than wood flour particles. The content of wood flour particles in the cellulose-based material particles 12 may be 50% by mass or more, or 80% by mass or more. The cellulose-based material particles 12 may also contain a single type of wood flour particle. The cellulose-based material particles 12 may be derived from waste. The wood flour particles may be, for example, ground waste wood separated from construction waste, thinned wood, sawdust, or other waste materials. The pulp particles may be, for example, ground waste paper, used cardboard, or other waste materials.
[0016] The content of the cellulose-based material particles 12 relative to the total amount of the resin composition molded body 10 is in the range of 10% by mass to 50% by mass. The content of the cellulose-based material particles 12 may be in the range of 20% by mass to 40% by mass. The ratio of the content of the cellulose-based material particles 12 to the content of the low-melting-point resin contained in the resin substrate 11 (content of cellulose-based material particles 12 / content of low-melting-point resin) may be 5.0 or less, 3.0 or less, less than 3.0, or 2.5 or less. The content of the cellulose-based material particles 12 may vary depending on the size of the cellulose-based material particles 12. For example, in the case of cellulose-based material particles that have passed through a sieve with a mesh size of 1 mm, the content may be in the range of 10% by mass to 50% by mass, and the ratio of the content of the cellulose-based material particles to the content of the low-melting-point resin may be in the range of 0.1 to 5.0 or in the range of 0.1 to 4.0. In the case of cellulose-based material particles that have passed through a sieve with a mesh size of 2 mm, the content may be in the range of 10% to 40% by mass, and the ratio of the content of cellulose-based material particles to the content of low-melting point resin may be in the range of 0.1 to 3.0, or in the range of 0.1 to 2.0. In the case of cellulose-based material particles that have passed through a sieve with a mesh size of 3 mm, the content may be in the range of 10% to 40% by mass, and the ratio of the content of cellulose-based material particles to the content of low-melting point resin may be in the range of 0.1 to 2.0, or in the range of 0.1 to 1.0.
[0017] The non-low melting point resin particles 13 dispersed in the resin substrate 11 include one or both of a high melting point resin and a thermosetting resin. The high melting point resin is a thermoplastic resin with a melting point of 190°C or higher. The melting point of the high melting point resin may be 340°C or lower. Examples of high melting point resins include polyethylene terephthalate (PET), polyamide 6 (PA6), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polyether ether ketone (PEEK). The thermosetting resin is a resin after curing. Examples of thermosetting resins include polyimide (PI), polyurethane (PU), and phenolic resin (PF).
[0018] The particle shape of the non-low melting point resin particles 13 is not particularly limited, and may be, for example, spherical, oval spherical, cylindrical, prismatic, plate-like, or amorphous. The particle size of the non-low melting point resin particles 13 is not particularly limited, but among particles having a major axis of 1.0 mm or more, the content of particles having a major axis of 3.0 mm or more may be 35% by number or less, or 20% by number or less. The content of particles having a major axis of less than 2 mm may be 30% by number or more, or 50% by number or less. The content of non-low melting point resin particles 13 having a major axis of 5.0 mm or more is 1.0 number / 100 mm as the average content contained in a 10 mm x 10 mm cross-sectional area of the resin composition molded product 10. ２ It may be less than 0.5 pieces / 100 mm ２ It may be the following:
[0019] The non-low melting point resin particles 13 may be those that pass through a sieve with a mesh size of 3 mm. The non-low melting point resin particles 13 may be those that pass through a sieve with a mesh size of less than 3 mm. Examples of sieves with a mesh size of less than 3 mm include sieves with a mesh size of 1 mm and sieves with a mesh size of 2 mm.
[0020] The non-low melting point resin particles 13 may be derived from waste, for example, a pulverized product of a high melting point resin or a thermosetting resin separated and recovered from waste plastic collected in accordance with the Containers and Packaging Recycling Law.
[0021] The content of the non-low melting point resin particles 13 is in the range of 10% by mass or more and 80% by mass or less as a content rate relative to the total amount of the resin composition molded product 10. The content of the non-low melting point resin particles 13 may be in the range of 15% by mass or more and 75% by mass or less, or may be in the range of 30% by mass or more and 60% by mass or less. When the resin composition molded product 10 does not contain the non-low melting point resin particles 13, recycled resin derived from waste containing a non-low melting point resin cannot be used as the resin raw material for the resin composition molded product 10. For this reason, CO2 emissions from the incineration of waste containing a non-low melting point resin ２ It cannot contribute to reducing emissions.
[0022] The content of the non-low melting point resin particles 13 may be equal to or greater than the content of the low melting point resin contained in the resin substrate 11. The content of the non-low melting point resin particles 13 and the low melting point resin, expressed as the ratio of the content of the non-low melting point resin particles 13 to the content of the low melting point resin (content of non-low melting point resin particles 13 / content of low melting point resin), may be, for example, 0.2 or more and less than 13, more than 0.6 and 10 or less, or 1 or more and 8 or less.
[0023] The total amount of the cellulose-based material particles 12 and the non-low melting point resin particles 13 dispersed in the resin substrate 11 may be less or more than that of the resin substrate 11. For example, when the content of the low melting point resin contained in the resin substrate 11 is X (unit: mass %), the content of the non-low melting point resin particles 13 is Y (unit: mass %), and the content of the cellulose-based material particles 12 is Z (unit: mass %), the difference (Y+Z)-X between the particle content (Y+Z) and the low melting point resin may satisfy, for example, the following formula (1): (Y+Z)-X≧-10 (1)
[0024] Furthermore, (Y+Z)-X may satisfy the following formula (2): 79≧(Y+Z)-X≧1 (2)
[0025] The resin composition molded product 10 of this embodiment may further contain an additive. Examples of the additive include various additives that are conventionally used in wood plastics, such as compatibilizers, pigments, weather resistance improvers, lubricants, heat stabilizers, fillers, foaming agents, and antistatic agents. The content of the additive relative to the total amount of the resin composition molded product 10 is, for example, in the range of 3% by mass to 10% by mass. The additive may be dissolved in the resin substrate 11 or dispersed in the resin substrate 11.
[0026] The resin composition molded product 10 of this embodiment may contain inevitable impurities. The inevitable impurities are impurities that are inevitably mixed in raw materials or during the production process. Examples of the inevitable impurities include aluminum derived from aluminum-deposited plastic contained in waste plastic used as a raw material for the low-melting point resin or non-low-melting point resin particles 13. The aluminum content relative to the total amount of the resin composition molded product 10 may be, for example, less than 1 mass%, less than 0.5 mass%, or less than 0.2 mass%.
[0027] In the resin composition molded body 10 of this embodiment configured as described above, the content of the low-melting point resin contained in the resin substrate 11 is within the above-mentioned range. Therefore, it can be manufactured at a heating temperature of, for example, less than 190°C, which allows the cellulosic material particles 12 and non-low-melting point resin particles 13 to be dispersed in the resin substrate 11 while suppressing the volatilization of low-molecular-weight components contained in the low-melting point resin, non-low-melting point resin, and cellulosic material, so that the cellulosic material particles 12 and non-low-melting point resin particles 13 are less likely to absorb water. Therefore, even when manufactured using recycled resin derived from waste containing non-low-melting point resins such as high-melting point resins and thermosetting resins, the resin composition molded body 10 of this embodiment is less likely to generate bubbles on the surface and exhibits excellent water resistance. By using recycled resin containing non-low-melting point resins, CO2 emissions from waste incineration can be reduced. ２ The resin composition molded article 10 of the present embodiment may have an equilibrium expansion coefficient of 20% or less, particularly 10% or less, as an index of water resistance, measured by the following measurement method, for example.
[0028] (Measurement Method) The resin composition molded body 10 is immersed in warm water adjusted to 60°C until the daily thickness change rate of the resin composition molded body 10 becomes 0.5% or less, and the thickness of the resin composition molded body 10 when the thickness change rate becomes 0.5% or less is defined as Tf (unit: mm), and the thickness of the resin composition molded body 10 before immersion in the warm water is defined as Ti (unit: mm), and the equilibrium expansion coefficient is calculated using the following formula (3): Equilibrium expansion coefficient (%) = {(Tf - Ti) / Ti} × 100 (3)
[0029] Furthermore, in the resin composition molded product 10 of this embodiment, the cellulose-based material particles 12 have a particle size within the above range, and the content in the resin composition molded product 10 is within the above range, so the texture of the resin composition molded product 10 due to the cellulose-based material particles 12 is improved. For example, if the cellulose-based material particles 12 are wood flour particles, the resin composition molded product 10 has an excellent wood texture. Furthermore, since the content in the resin composition molded product 10 of the non-low melting point resin particles 13 is within the above range, high melting point resins and thermosetting resins that are often incinerated can be effectively utilized, and CO2 emissions from the incineration of waste materials can be reduced. ２ This will make a significant contribution to reducing emissions.
[0030] In the resin composition molded product 10 of this embodiment, when the content of cellulose-based material particles 12 having a major axis of 1.0 mm or more is 35% or less by number of particles having a major axis of 3.0 mm or more, the particle diameter of the cellulose-based material particles 12 is small, and the surfaces of the cellulose-based material particles 12 are easily coated with the low-melting-point resin. As a result, the cellulose-based material particles 12 are less likely to fall off from the resin composition molded product 10 and are less likely to absorb water, improving the water resistance of the resin composition molded product 10. Furthermore, when the cellulose-based material particles 12 have passed through a sieve with a mesh size of 3 mm, coarse cellulose-based material particles 12 are less likely to be mixed in, and the surfaces of the cellulose-based material particles 12 can be more reliably coated with the low-melting-point resin.
[0031] In the resin composition molded product 10 of this embodiment, when the content of non-low melting point resin particles 13 having a major axis of 1.0 mm or more is 35% or less by number, the particle diameter of the non-low melting point resin particles 13 is small, and the surfaces of the non-low melting point resin particles 13 are easily coated with the low melting point resin. Therefore, the non-low melting point resin particles 13 are less likely to fall off from the resin composition molded product 10. Furthermore, when the non-low melting point resin particles 13 have passed through a sieve with a mesh size of 3 mm, coarse non-low melting point resin particles 13 are less likely to be mixed in, and the surfaces of the non-low melting point resin particles 13 can be more reliably coated with the low melting point resin.
[0032] In the resin composition molded body 10 of this embodiment, when the ratio of the content of cellulose-based material particles 12 to the content of low-melting point resin contained in the resin substrate 11 is 3.0 or less, the surface of the cellulose-based material particles 12 can be more reliably coated with the low-melting point resin.
[0033] In the resin composition molded product 10 of this embodiment, when the low-melting-point resin contained in the resin substrate 11 includes polyethylene with a melting point of less than 160°C and polypropylene with a melting point of 160°C or higher, the fluidity of the resin substrate 11 is improved by heating, so that the cellulose-based material particles 12 and the non-low-melting-point resin particles 13 can be dispersed more uniformly and air bubbles are less likely to be generated. When the mass ratio of polyethylene to polypropylene is 1.4 or less, the effect of using polyethylene and polypropylene in combination can be more reliably obtained.
[0034] The resin composition molded body 10 of this embodiment can be used, for example, as civil engineering materials, building materials, and gardening materials. Examples of civil engineering materials include paving materials. Examples of building materials include flooring materials, particularly bathroom flooring materials, roofing materials, wall materials, handrails, sashes, wood decks, and fences. Examples of gardening materials include flower beds. The resin composition molded body 10 has excellent water resistance and is therefore useful, particularly as paving materials and building materials used outdoors. Furthermore, a wood flour particle-containing resin composition molded body 10 in which the cellulose-based material particles 12 are wood flour particles can be used as a wood plastic. The shape of the resin composition molded body 10 is not particularly limited, and can be block-shaped, plate-shaped, or columnar, depending on the intended use.
[0035] Next, an embodiment of a paving material using the resin composition molded product 10 of this embodiment will be described. As shown in Figure 2, the paving material 20 of this embodiment is a square plate-like body in a plan view. The surface 21 of the paving material 20 has a plurality of convex portions extending parallel to each other. The paving material 20 has a pair of opposing side surfaces, one of which has a male tongue 22 and the other of which has a female tongue 23.
[0036] As shown in Figure 3, the paving material 20 is laid on top of a layered structure of a concrete slab 33 and leveling material 34, which are formed in this order within an area surrounded by curbstone blocks 32 on a roadbed 31. The concrete slab 33 contains reinforcing bars. The leveling material 34 can be mortar or sand.
[0037] The paving material 20 is joined by fitting the male tongue 22 and the female tongue 23 together. When it rains, rainwater flows out through the gap between the male tongue 22 and the female tongue 23 of the paving material 20. Therefore, rainwater is less likely to accumulate on the surface 21 side of the paving material 20.
[0038] Next, a description will be given of a method for producing the resin composition molded product 10 of this embodiment. The resin composition molded product 10 can be produced, for example, by a method including a preparation step of preparing a raw material composition powder and a formation step of forming the resin composition molded product 10 using the raw material composition powder.
[0039] The raw material composition powder prepared in the preparation step is a powder of a composition including waste-derived low-melting-point resin particles, cellulosic material particles, and waste-derived non-low-melting-point resin particles. The low-melting-point resin particles include a low-melting-point resin having a melting point in the range of 80°C or higher and lower than 190°C. The low-melting-point resin particles may have passed through a sieve with a mesh size of 3 mm. The content of the low-melting-point resin is in the range of 10% by mass or higher and 80% by mass or lower, as a percentage of the total amount of the raw material composition powder. The cellulosic material particles may have passed through a sieve with a mesh size of 3 mm. The content of the cellulosic material particles is in the range of 20% by mass or higher and 50% by mass or lower, as a percentage of the total amount of the raw material composition powder. The non-low-melting-point resin particles include one or both of a high-melting-point resin and a thermosetting resin having a melting point of 190°C or higher. The non-low-melting-point resin particles may have passed through a sieve with a mesh size of 3 mm. The content of the non-low melting point resin particles is in the range of 10% by mass to 80% by mass relative to the total amount of the raw material composition powder.
[0040] The raw material composition powder can be produced, for example, by mixing low-melting-point resin particles, cellulose-based material particles, and non-low-melting-point resin particles in a ratio that satisfies the above-mentioned range. Alternatively, the raw material composition powder can be produced, for example, by mixing agglomerates of low-melting-point resin, agglomerates of cellulose-based material, and agglomerates of non-low-melting-point resin particles in a ratio that satisfies the above-mentioned range, pulverizing the resulting mixture, and then classifying the mixture using a sieve with a mesh size of 3 mm or less.
[0041] The particle size of the cellulose-based material particles and non-low-melting-point resin particles in the raw material composition powder may include particles less than 1.0 mm in a range of 10% by number to 85% by number, particles of 1.0 mm or more and less than 2.0 mm in a range of 15% by number to 50% by number, particles of 2.0 mm or more and less than 3.0 mm in a range of 0% by number to 40% by number, and particles of 3.0 mm or more in a range of 0% by number to 30%.
[0042] In the forming step, the raw material composition powder is heated and kneaded at a temperature equal to or higher than the melting point of the low-melting-point resin particles and lower than 190°C. The kneading temperature may be 150°C or higher, or may be in the range of 165°C to 180°C. By the heating and kneading, a melt is generated in which the low-melting-point resin particles in the raw material composition powder are melted. The generated melt is then molded into a desired shape. As a method for molding the melt, various methods used as molding methods for thermoplastic resins, such as extrusion molding and injection molding, can be used.
[0043] According to the manufacturing method of the resin composition molded product 10 of this embodiment configured as described above, the kneading temperature in the forming step is within the above-mentioned range, so that the low-molecular-weight components contained in the raw material composition powder are less likely to volatilize. Therefore, the resulting resin composition molded product 10 is less likely to generate bubbles. In the manufacturing method of the resin composition molded product 10 of this embodiment, if the particle sizes of the cellulose-based material particles and the non-low-melting-point resin particles are within the above-mentioned range, a resin composition molded product 10 having a uniform composition and high water resistance can be obtained without pelletizing the raw material composition powder before the forming step. However, even in the manufacturing method of the resin composition molded product 10 of this embodiment, the raw material composition powder may be pelletized before the forming step.
[0044] The present disclosure will be described in more detail below with reference to examples. The present disclosure is not limited to these examples. In these examples, the following low-melting-point resins, wood chips, and non-low-melting-point resins were used as raw materials. Low-melting-point resin powder (PE powder): pulverized polyethylene (melting point: 150°C) separated and recovered from waste plastic collected in accordance with the Container and Packaging Recycling Law. Low-melting-point resin powder (PP powder): pulverized polypropylene (melting point: 160°C) separated and recovered from waste plastic collected in accordance with the Container and Packaging Recycling Law. Non-low-melting-point resin powder (PET powder): pulverized polyethylene terephthalate (PET) separated and recovered from waste plastic collected in accordance with the Container and Packaging Recycling Law, and classified using sieves with openings of 1 mm, 2 mm, and 3 mm (melting point: 250°C). Wood powder: pulverized construction waste wood separated from construction waste and classified using sieves with openings of 1 mm, 2 mm, and 3 mm.
[0045] The particle size distributions of the PET powder and wood powder classified using sieves with openings of 1 mm, 2 mm, and 3 mm are shown in Table 1 below. In Table 1, the 1 mm, 2 mm, and 3 mm classifications represent products classified using sieves with openings of 1 mm, 2 mm, and 3 mm, respectively. The particle size distributions of the PET powder and wood powder were obtained by measuring the major axis of 1,000 particles using a microscope and an image size measuring device, and calculating the number percentage of particles less than 1.0 mm, the number percentage of particles 1.0 mm or more and less than 2.0 mm, the number percentage of particles 2.0 mm or more and less than 3.0 mm, and the number percentage of particles 3.0 mm or more. The particle size distributions of the PET powder and wood powder were each measured three times.
[0046]
[0047] [Example 1] A raw material composition powder was prepared by mixing 10 parts by mass of PE powder, 5 parts by mass of PP powder, 50 parts by mass of PET powder (2 mm fraction), and 30 parts by mass of wood powder (2 mm fraction). 90 parts by mass of this raw material composition powder was mixed with 10 parts by mass of additives, and the resulting mixture was placed in an extrusion molding machine. The paving material shown in Figure 2 was produced at a kneading and molding temperature of 165 °C. The additives used were a compatibilizer, pigment, weather resistance improver, lubricant, and thermal stabilizer. The resulting paving material was a plate-shaped body measuring 300 mm long x 300 mm wide x 30 mm thick. The content ratios of low-melting point resin (PE, PP), non-low-melting point resin (PET), wood powder, and additives in the resulting paving material were the same as those of the raw materials.
[0048] [Examples 2 to 15, Comparative Examples 1 to 5] Raw material composition powders were prepared in the same manner as in Example 1, except that the blending ratios of PE powder, PP powder, PET powder, and wood powder were changed to the ratios shown in Table 2 below, and the types of PET powder and wood powder were changed to those shown in Table 2 below. Then, using the obtained raw material composition powders, paving materials were prepared in the same manner as in Example 1, except that the kneading and molding temperature of the extrusion molding machine was set to the temperature shown in Table 2 below. In Comparative Example 3, a non-low melting point resin was not used.
[0049] [Evaluation] The resulting paving materials were evaluated for the proportion of non-low melting point resin, appearance (woody texture, foaming), and water resistance (equilibrium expansion coefficient) as follows. The results are shown in Table 2 below.
[0050] <Ratio of non-low melting point resin> The ratio of non-low melting point resin in the paving material was calculated. When the ratio of non-low melting point resin was more than 10 mass%, it was rated as "A", and when it was 10 mass% or less, it was rated as "B".
[0051] <Appearance (wood texture, foaming)> The surface of the paving material was visually observed. The wood texture was evaluated visually. A case in which there was a change from light to dark brown and the wood texture was present was rated "A", a case in which there was only dark brown and the wood texture was present was rated "B", and a case in which there was only dark brown and the wood texture was not present was rated "C". Foaming was evaluated by measuring the expansion in the thickness direction immediately after removal from the mold of the extrusion molding machine. An expansion of less than 0.5 mm was rated "A", an expansion of 0.5 mm or more but less than 2.0 mm was rated "B", and an expansion of 2.0 mm or more was rated "C".
[0052] <Water resistance (equilibrium expansion rate)> The paving material is immersed in warm water adjusted to 60°C. Every day, the paving material is removed from the warm water and the thickness of the paving material is measured. The rate of change in thickness of the paving material compared to the thickness of the paving material on the previous day is calculated using the following formula: Rate of change in thickness of paving material (%) = (thickness of paving material - thickness of paving material on the previous day) / thickness of paving material on the previous day x 100
[0053] When the change in thickness of the paving material becomes 0.5% or less, the expansion rate of the paving material due to water absorption is considered to have reached equilibrium, and the equilibrium expansion rate of the paving material thickness is calculated using the following formula (3). The thickness of the paving material was taken as the average of the thicknesses of the central part of the plane and the parts near each of the four corners, a total of five locations. Equilibrium expansion rate (%) = {(Tf - Ti) / Ti} x 100 (3) In formula (3), Tf (unit: mm) is the thickness of the resin composition molded body when the change in thickness becomes 0.5% or less, and Ti (unit: mm) is the thickness of the resin composition molded body before immersion in warm water. Water resistance was evaluated as "A" when the equilibrium expansion rate was 10% or less, "B" when it was more than 10% and 20% or less, and "C" when it was more than 20%.
[0054]
[0055] The results shown in Table 2 indicate that paving materials with low-melting-point resin, non-low-melting-point resin particle, and wood flour particle contents within the ranges of the present disclosure have excellent appearance and water resistance. Therefore, these paving materials can be advantageously used as paving materials for outdoor use. In particular, the paving materials obtained in Examples 1 to 6, in which 2mm-classified wood powder was used and the wood powder / low-melting-point resin ratio was 2.0 or less, and in Examples 8, 10 to 12, and 14, in which 1mm-classified wood powder was used and the wood powder / low-melting-point resin ratio was 4.0 or less, exhibited water resistance of A (equilibrium expansion coefficient in 60°C hot water of 10% or less), demonstrating excellent water resistance.
[0056] In contrast, the paving materials obtained in Comparative Examples 1 and 2, which had a low content of low-melting-point resin compared to the range of the present disclosure, were rated water resistance C (equilibrium expansion coefficient in 60°C hot water exceeds 20%). This is because the low content of low-melting-point resin meant that some of the wood flour particles were not coated with the low-melting-point resin, making them more susceptible to absorbing hot water. Comparative Example 3, which did not use a non-low-melting-point resin, showed excellent water resistance, but the CO2 emissions from the incineration of waste containing non-low-melting-point resins were low. ２ Comparative Example 4, which has a higher wood powder content than the range of the present disclosure, received a water resistance rating of C. This is because the high wood powder content made it easier to absorb hot water.
[0057] Comparative Example 5 A paving material was produced in the same manner as in Example 3, except that the kneading and molding temperature of the extruder was set to 200° C. The foaming evaluation result of the resulting paving material was rated C. This was because the low-molecular-weight components contained in the raw material composition powder volatilized, causing bubbles to form on the surface of the paving material.
[0058] The following additional notes apply to aspects of the present disclosure: (Additional Note 1) A molded product of a composition including a resin substrate containing a low-melting-point resin, cellulose-based material particles dispersed in the resin substrate, and non-low-melting-point resin particles dispersed in the resin substrate, wherein the low-melting-point resin has a melting point in the range of 80°C or higher but lower than 190°C and a content of the low-melting-point resin in the total amount of the composition in the range of 10% by mass or higher and 80% by mass or lower, the cellulose-based material particles include at least wood flour particles and a content of the cellulose-based material particles in the total amount of the composition in the range of 10% by mass or higher and 50% by mass or lower, and the non-low-melting-point resin particles include one or both of a high-melting-point resin and a thermosetting resin, each having a melting point of 190°C or higher, and a content of the non-low-melting-point resin particles in the total amount of the composition in the range of 10% by mass or higher and 80% by mass or lower.
[0059] (Appendix 2) The resin composition molded product according to Appendix 1, wherein the cellulose-based material particles and the non-low melting point resin particles have a major axis of 1.0 mm or more, and a content of particles having a major axis of 3.0 mm or more is 35% by number or less.
[0060] (Appendix 3) The molded article of the resin composition according to Appendix 2, wherein the content of particles having a major axis of 3.0 mm or more is 20% by number or less.
[0061] (Appendix 4) The resin composition molded product according to any one of Appendices 1 to 3, wherein the cellulose-based material particles and the non-low melting point resin particles are passed through a sieve having an opening of 3 mm.
[0062] (Appendix 5) The resin composition molded product according to Appendix 4, wherein the cellulose-based material particles and the non-low melting point resin particles are passed through a sieve having an opening of 2 mm.
[0063] (Appendix 6) The resin composition molded body according to any one of Appendices 1 to 5, wherein the ratio of the content of the cellulose-based material particles to the content of the low-melting point resin (cellulose-based material particles / low-melting point resin) is 5.0 or less.
[0064] (Appendix 7) The resin composition molded article according to Appendix 6, wherein the ratio of the content of the cellulose-based material particles to the content of the low-melting-point resin (cellulose-based material particles / low-melting-point resin) is 3.0 or less.
[0065] (Appendix 8) The resin composition molded article according to Appendix 7, wherein the ratio of the content of the cellulose-based material particles to the content of the low-melting-point resin (cellulose-based material particles / low-melting-point resin) is 2.5 or less.
[0066] (Appendix 9) The molded article of the resin composition according to any one of Appendices 1 to 8, wherein the low melting point resin contains at least two types of resin.
[0067] (Appendix 10) The resin composition molded article according to Appendix 9, wherein the low melting point resin contains at least polyethylene and polypropylene.
[0068] (Appendix 11) The resin composition molded article according to Appendix 10, wherein the content of the polyethylene and the content of the polypropylene are such that the mass ratio of the polyethylene to the polypropylene is 1.4 or less.
[0069] (Appendix 12) The resin composition molded article according to Appendix 11, wherein the content of the polyethylene and the content of the polypropylene are such that the mass ratio of the polyethylene to the polypropylene is 1.2 or less.
[0070] (Appendix 13) The resin composition molded article according to any one of Appendices 1 to 12, wherein the content of the low melting point resin is in the range of 10% by mass to 50% by mass.
[0071] (Appendix 14) The resin composition molded article according to any one of Appendices 1 to 13, wherein the content of the non-low melting point resin particles is equal to or greater than the content of the low melting point resin.
[0072] (Appendix 15) The molded article of the resin composition according to any one of Appendices 1 to 14, wherein the content of the non-low melting point resin particles is in the range of 15% by mass to 75% by mass.
[0073] (Appendix 16) The molded article of the resin composition according to Appendix 15, wherein the content of the non-low melting point resin particles is in the range of 30% by mass to 60% by mass.
[0074] (Appendix 17) The molded article of the resin composition according to any one of Appendices 1 to 16, wherein the aluminum content relative to the total amount of the composition is less than 1 mass%.
[0075] (Appendix 18) The resin composition molded article according to any one of Appendices 1 to 17, wherein when the content of the low melting point resin is X (unit: mass%), the content of the non-low melting point resin particles is Y (unit: mass%), and the content of the cellulose-based material particles is Z (unit: mass%), (Y+Z)-X satisfies the following formula (1): (Y+Z)-X≧-10 (1)
[0076] (Appendix 19) The molded article of the resin composition according to Appendix 18, wherein (Y+Z)-X satisfies the following formula (2): 79≧(Y+Z)-X≧1 (2)
[0077] (Appendix 20) The resin composition molded article according to any one of Appendices 1 to 19, having an equilibrium expansion coefficient of 20% or less, as measured by the following measurement method. (Measurement Method) A resin composition molded article is immersed in warm water adjusted to 60°C until the daily thickness change rate of the resin composition molded article becomes 0.5% or less, and the equilibrium expansion coefficient is calculated using the following formula (3), where Tf (unit: mm) is the thickness of the resin composition molded article when the thickness change rate becomes 0.5% or less, and Ti (unit: mm) is the thickness of the resin composition molded article before immersion in the warm water. Equilibrium expansion coefficient (%) = {(Tf - Ti) / Ti} × 100 (3)
[0078] (Appendix 21) The resin composition molded article according to Appendix 20, wherein the equilibrium expansion coefficient is 10% or less.
[0079] (Appendix 22) The resin composition molded article according to any one of Appendices 1 to 21, which is in the shape of a block, a plate, or a column.
[0080] (Appendix 23) A civil engineering material comprising a molded article of the resin composition according to any one of Appendices 1 to 22.
[0081] (Appendix 24) A building material comprising a molded article of the resin composition according to any one of Appendices 1 to 22.
[0082] (Appendix 25) A gardening material comprising a molded article of the resin composition according to any one of Appendices 1 to 22.
[0083] (Appendix 26) A method for producing a resin composition molded product, comprising: preparing a raw material composition powder comprising waste-derived low-melting-point resin particles, cellulosic material particles, and waste-derived non-low-melting-point resin particles, wherein the low-melting-point resin particles comprise a low-melting-point resin having a melting point in the range of 80°C or more and less than 190°C, and the content of the low-melting-point resin relative to the total amount of the composition is in the range of 10% by mass or more and 80% by mass or less, the content of the cellulosic material particles relative to the total amount of the composition is in the range of 10% by mass or more and 50% by mass or less, and the non-low-melting-point resin particles comprise one or both of a high-melting-point resin and a thermosetting resin having a melting point of 190°C or more, and the content of the non-low-melting-point resin particles relative to the total amount of the composition is in the range of 10% by mass or more and 80% by mass or less, and heating and kneading the raw material composition powder at a temperature equal to or higher than the melting point of the low-melting-point resin particles and lower than 190°C.
[0084] (Appendix 27) The method for producing a resin composition molded product according to Appendix 26, wherein the cellulose-based material particles and the non-low melting point resin particles are passed through a sieve having a mesh size of 3 mm.
[0085] 10...resin composition molded body, 11...resin substrate, 12...cellulose-based material particles, 13...non-low melting point resin particles, 20...paving material, 21...surface, 22...male tongue, 23...female tongue, 31...roadbed, 32...curbstone block, 33...earth floor concrete, 34...leveling material
Claims
1. A molded body of a composition comprising a resin substrate containing a low melting point resin, cellulose-based material particles dispersed in the resin substrate, and non-low melting point resin particles dispersed in the resin substrate, wherein the low melting point resin has a melting point in the range of 80°C or higher and lower than 190°C, and the content of the low melting point resin in the total amount of the composition is in the range of 10% by mass or higher and 80% by mass or lower, the cellulose-based material particles include at least wood flour particles, and the content of the cellulose-based material particles in the total amount of the composition is in the range of 10% by mass or higher and 50% by mass or lower, and the non-low melting point resin particles include one or both of a high melting point resin and a thermosetting resin having a melting point of 190°C or higher, and the content of the non-low melting point resin particles in the total amount of the composition is in the range of 10% by mass or higher and 80% by mass or lower.
2. A resin composition molded body as described in claim 1, wherein, among the cellulose-based material particles and the non-low melting point resin particles having a major axis of 1.0 mm or more, the content of particles having a major axis of 3.0 mm or more is 35% or less by number.
3. A resin composition molded body according to claim 1 or 2, wherein the cellulose-based material particles and the non-low melting point resin particles have been passed through a sieve having an opening of 3 mm.
4. A resin composition molded body according to any one of claims 1 to 3, wherein the ratio of the content of the cellulose-based material particles to the content of the low melting point resin is 5.0 or less.
5. A molded article of a resin composition according to any one of claims 1 to 4, wherein the low melting point resin comprises at least two types of resin.
6. The molded article of a resin composition according to claim 5, wherein the low melting point resin contains at least polyethylene and polypropylene.
7. A resin composition molded article according to claim 6, wherein the content of the polyethylene and the polypropylene is such that the mass ratio of the polyethylene to the polypropylene is 1.4 or less.
8. A resin composition molded body described in any one of claims 1 to 7, wherein the content of the low melting point resin is in the range of 10 mass % or more and 50 mass % or less.
9. A molded article of a resin composition according to any one of claims 1 to 8, wherein the content of the non-low melting point resin particles is equal to or greater than the content of the low melting point resin.
10. A molded article of the resin composition according to any one of claims 1 to 9, which is in the shape of a block, plate or column.
11. A civil engineering material comprising a molded article of the resin composition according to any one of claims 1 to 10.
12. A building material comprising a molded article of the resin composition according to any one of claims 1 to 10.
13. A horticultural material comprising a molded article of the resin composition according to any one of claims 1 to 10.
14. A method for producing a resin composition molded product, comprising: preparing a raw material composition powder comprising waste-derived low melting point resin particles, cellulose-based material particles, and waste-derived non-low melting point resin particles, wherein the low melting point resin particles comprise a low melting point resin having a melting point in the range of 80°C or more and less than 190°C, and the content of the low melting point resin in the total amount of the composition is in the range of 10% by mass or more and 80% by mass or less, the content of the cellulose-based material particles in the total amount of the composition is in the range of 10% by mass or more and 50% by mass or less, and the non-low melting point resin particles comprise one or both of a high melting point resin and a thermosetting resin having a melting point of 190°C or more, and the content of the non-low melting point resin particles in the total amount of the composition is in the range of 10% by mass or more and 80% by mass or less, and heating and kneading the raw material composition powder at a temperature equal to or more than the melting point of the low melting point resin particles and less than 190°C.
15. The method for producing a resin composition molded product according to claim 14, wherein the cellulose-based material particles and the non-low melting point resin particles are passed through a sieve having a mesh size of 3 mm.