Block member

Abstract

To provide a block member having high strength.SOLUTION: A block member comprising polypropylene (A), composite material powder (B), and a compatibilizer (C), wherein the composite material powder (B) is a powder of a fiber-reinforced composite material comprising a cured product of a resin composition and reinforcing fibers.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a block member. [Background technology]

[0002] For example, when constructing a building on a soft foundation, it is necessary to lay a temporary road between the main road and the work site in order to transport the base materials and other materials required for the work. Large construction vehicles such as large cranes are used on temporary floors such as temporary roads, but these vehicles are heavy. In addition, heavy loads are placed on the ground supporting the vehicles as they perform tasks such as lifting and moving heavy objects such as steel frames.

[0003] Therefore, temporary floors are required to be strong and durable. For example, Patent Document 1 discloses a temporary floor made of an assembly of a plurality of rectangular parallelepiped blocks made of resin foam that are adjacent to each other and further stacked one on top of the other in multiple levels. Patent document 2 discloses a method in which mat-like molded bodies having voids surrounded by a large number of partitions or protrusions made of synthetic resin are connected and laid out, and the voids of the mat-like molded bodies are filled with a filler containing a granular porous body. Other known methods include combining sand, crushed stone, sleepers, and iron plates.

[0004] Furthermore, materials that can withstand vertical loads are also required for rainwater storage block members. For example, Patent Document 3 discloses a block member made of a resin composition containing polypropylene resin and glass fiber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-177005 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-90006 [Patent Document 3] Japanese Patent Application Publication No. 2017-179786 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the temporary floor described in Patent Document 1 and the method described in Patent Document 2 have the problem that construction is time-consuming. In the block member described in Patent Document 3, the polypropylene resin and the glass fiber have poor compatibility, and the adhesion between them is insufficient, so durability is not necessarily satisfactory. An object of the present invention is to provide a block member having high strength. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A block member comprising polypropylene (A), a composite material powder (B), and a compatibilizer (C), wherein the composite material powder (B) is a powder of a fiber-reinforced composite material containing a cured product of a resin composition and reinforcing fibers. [2] The block member according to [1], wherein the content of the composite material powder (B) is 1 to 30 mass % relative to the total mass of the block member. [3] The block member according to [1] or [2] above, wherein the reinforcing fibers contained in the composite material powder (B) have an average fiber length of 50 to 150 μm. [4] The block member according to any one of [1] to [3] above, wherein the content of the compatibilizer (C) is 0.1 to 5 mass % relative to the total mass of the block member. [5] The block member according to any one of [1] to [4] above, wherein the compatibilizer (C) contains a silane-modified polyolefin. [6] The block member according to any one of [1] to [5], wherein the reinforcing fibers include glass fibers. [Effects of the Invention]

[0008] According to the present invention, a block member having high strength can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes in detail the form for implementing the present invention. However, the following description is an example of an embodiment of the present invention, and the present invention is not limited to the contents of the following description as long as it does not go beyond the gist of the present invention. In this specification, the use of "to" to indicate a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0010] [Block material] The block member of the present invention contains polypropylene (A), composite material powder (B), and compatibilizer (C) shown below. The block member may further contain other components (optional components) in addition to the polypropylene (A), the composite material powder (B), and the compatibilizer (C), as necessary, within a range that does not impair the effects of the present invention.

[0011] <Polypropylene (A)> Polypropylene (A) serves as the base resin. Examples of the polypropylene (A) include a homopolymer of propylene (homopolypropylene) and a copolymer of propylene with other monomers.

[0012] When the polypropylene (A) is a copolymer, it may be a random copolymer or a block copolymer. When the polypropylene (A) is a copolymer, the other monomers are not particularly limited as long as they are copolymerizable with propylene, and examples thereof include ethylene, 1-butene, 1-pentene, isobutylene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 4-methyl-1-pentene, 3-methyl-1-hexene, 1-octene, and other α-olefins having 4 to 10 carbon atoms. The other monomers may be used alone or in combination of two or more. Specific examples of the copolymer include a random copolymer of propylene and ethylene (ethylene-propylene random copolymer), a block copolymer of propylene and ethylene (ethylene-propylene block copolymer), a random copolymer of propylene, ethylene, and an α-olefin having 4 to 10 carbon atoms, a block copolymer of propylene, ethylene, and an α-olefin having 4 to 10 carbon atoms, a random copolymer of propylene and an α-olefin having 4 to 10 carbon atoms, and a block copolymer of propylene and an α-olefin having 4 to 10 carbon atoms.

[0013] The polypropylene (A) may be a recycled material for containers and packaging. Examples of recycled materials include plastic waste collected by local governments that has undergone pre-processing such as sorting, washing, crushing, and gravity separation, and then undergoes a granulation process to be molded into a specific shape such as pellets or reduced-volume products (crushed products compressed and solidified). In addition, recycled polypropylene (A) is also called "recycled polypropylene (A)". The polypropylene (A) may be used alone or in combination of two or more kinds.

[0014] The content of polypropylene (A) is preferably 69.9 to 98.9 mass%, more preferably 74.5 to 89.5 mass%, and even more preferably 79 to 84 mass%, relative to the total mass of the block member. When the content of polypropylene (A) is equal to or greater than the lower limit, the fluidity of the resin composition (x) at the time of melting is less likely to decrease when preparing the resin composition (x) described below, and good moldability can be maintained when molding the resin composition (x) to produce a block member. When the content of polypropylene (A) is equal to or less than the upper limit, the content of composite material powder (B) described below can be increased, and when a load is applied to the block member, the load is more easily transmitted to the reinforcing fibers, thereby further improving the strength of the block member.

[0015] <Composite material powder (B)> The composite material powder (B) is a powder of a fiber-reinforced composite material containing a cured product of the resin composition (b) and reinforcing fibers. That is, the composite material powder (B) contains a cured product of the resin composition (b) and reinforcing fibers. The composite powder (B) acts as a filler. When the block member contains composite material powder (B), the reinforcing fibers in the composite material powder (B) act as a reinforcing material. Therefore, when a load is applied to the block member, the load is transmitted not only to the base resin polypropylene (A) but also to the reinforcing fibers, improving the strength of the block member as a whole. In addition, since the surface area of ​​the composite material powder (B) is larger than that of individual reinforcing fibers or bundled reinforcing fibers, it has a larger contact area with the base resin polypropylene (A), increasing adhesion with the polypropylene (A), and the anchor effect makes it easier for strength to be expressed.

[0016] It is preferred that a part or all of the cured product of the resin composition (b) is attached to the reinforcing fibers. The cured product of the resin composition (b) may be a foam or a non-foam, i.e., the cured product of the resin composition (b) may or may not have voids derived from the foaming agent. A fiber-reinforced composite material in which the cured product of the resin composition (b) is a foam is also referred to as a "foamed fiber-reinforced composite material" or a "foamed resin molded product."

[0017] Examples of the resin component contained in the resin composition (b) include thermosetting resins such as urethane resins, epoxy resins, vinyl ester resins, unsaturated polyester resins, and phenolic resins, as well as raw materials for these thermosetting resins. Among these, urethane resins or raw materials for them are more preferred. The thermosetting resin may be used alone or in combination of two or more kinds. The resin composition (b) containing a urethane resin or a raw material thereof is also referred to as a "urethane resin composition (b1)," and a fiber-reinforced composite material containing a cured product of the urethane resin composition (b1) and reinforcing fibers is also referred to as a "urethane resin molded product." Among these, a fiber-reinforced composite material in which the cured product of the urethane resin composition (b1) is a foam is also referred to as a "urethane resin foam molded product."

[0018] The resin composition (b) contains, for example, the above-mentioned thermosetting resin or a raw material thereof. When the cured product of the resin composition (b) is a foam, the resin composition (b) contains a thermosetting resin and a foaming agent. For example, when the resin composition (b) is a urethane resin composition (b1), the urethane resin composition (b1) may contain, instead of a urethane resin, a polyol and a polyisocyanate which are raw materials for the urethane resin, and, if necessary, a catalyst, etc. The resin composition (b) may further contain other additives, if necessary.

[0019] The foaming agent is not particularly limited, and any foaming agent known in the field of fiber reinforced composite materials can be used, such as water. The other additives are not particularly limited, and any additive known in the field of fiber-reinforced composite materials can be used. Examples of such additives include carbonate compounds such as calcium carbonate, magnesium carbonate, zinc carbonate, and barium carbonate; minerals such as dawsonite, hydrotalcite, mica, imogolite, sericite, and gypsum fiber; sulfate compounds such as calcium sulfate, barium sulfate, and magnesium sulfate; silicate compounds such as calcium silicate; clays such as talc, clay, montmorillonite, bentonite, activated clay, and sepiolite; nitrides such as aluminum nitride, boron nitride, and silicon nitride; carbon compounds such as carbon black, graphite, carbon balloons, and charcoal powder; titanium compounds such as potassium titanate and lead zirconate titanate; metal borate compounds such as aluminum borate; sulfides such as molybdenum sulfide; carbides such as silicon carbide; hydroxides such as aluminum hydroxide; ash such as fly ash, coal ash, and shirasu balloons; sand such as silica sand; pyroclastic materials such as pumice; perlite; glass balloons; wood chips; bamboo chips; starch; and rice bran. The other additives may be used alone or in combination of two or more.

[0020] Examples of reinforcing fibers include inorganic fibers such as glass fibers, carbon fibers, and metal fibers; and organic fibers such as natural fibers and synthetic fibers. Among these, glass fibers are preferred from the viewpoints of strength and economy. That is, the composite material powder (B) preferably contains glass fibers. The reinforcing fibers may be used alone or in combination of two or more types.

[0021] Examples of glass fibers include glass roving, glass roving cloth, glass mat, and continuous strand mat. The glass fibers may be used alone or in combination of two or more types, and may be used as a mixture of long and short fibers.

[0022] The composite material powder (B) can be obtained from a fiber-reinforced composite material containing a cured product of the resin composition (b) and reinforcing fibers. Examples of the composite material powder (B) that can be used include pulverized unused fiber-reinforced composite materials, scraps (waste) generated when processing fiber-reinforced composite materials into a predetermined shape, and pulverized fiber-reinforced composite materials (waste) after use as products (for example, sleepers). Note that scraps, used fiber-reinforced composite materials, and other materials that have conventionally been treated as waste are also referred to as fiber-reinforced composite materials. The composite material powder (B) may be a molded product formed into an unintended shape, which can reduce the environmental load and the cost. The composite material powder (B) may be a powder of a foamed resin molded product. The composite material powder (B) may be used alone or in combination of two or more kinds.

[0023] From the viewpoint of reducing the environmental load and reducing costs, the composite material powder (B) is preferably chips of a fiber-reinforced composite material or pulverized used fiber-reinforced composite material. Here, "chips" refers to pieces of debris such as powder (cutting chips) generated when cutting a fiber-reinforced composite material, powder (grinding chips) generated when the surface of a fiber-reinforced composite material is sanded, and powder (cutting chips) generated when part of a fiber-reinforced composite material is scraped off. The composite material powder (B) is preferably cutting chips, grinding chips, or shavings of a fiber-reinforced composite material.

[0024] The shape of the composite material powder (B) may be spherical or may be a shape other than spherical (for example, polygonal, plate-like, or scale-like).

[0025] The particle size of the composite material powder (B) is not particularly limited, but is preferably, for example, about 75 to 200 μm. If the particle size of the composite material powder (B) is within the above range, the moldability when molding the resin composition (x) described below will be better. The particle size of the composite material powder (B) can be adjusted by classification, etc. For classification, a known classification device, such as a circular vibration sieving machine equipped with a wire mesh sieve with a predetermined mesh size, can be used.

[0026] The particle size of the composite material powder (B) means the diameter value corresponding to 50% of the volume-based cumulative fraction of particle size distribution measured by a laser diffraction particle size distribution analyzer, calculated from the smaller particle size side.

[0027] The average fiber length of the reinforcing fibers contained in the composite material powder (B) is preferably 50 to 150 μm, more preferably 100 to 150 μm, and even more preferably 125 to 150 μm. If the average fiber length of the reinforcing fibers is equal to or greater than the above lower limit, when a load is applied to the block member, the load is easily transmitted to the reinforcing fibers, thereby further improving the strength of the block member. If the average fiber length of the reinforcing fibers is equal to or less than the above upper limit, the fluidity of the reinforcing fibers when melted is less likely to decrease when preparing the resin composition (x) described below, and good moldability can be maintained when molding the resin composition (x) to produce a block member. The average fiber length of the reinforcing fibers contained in the composite material powder (B) can be adjusted by classification or the like.

[0028] The average fiber length of the reinforcing fibers can be measured as follows. That is, the reinforcing fibers contained in the composite material powder (B) are photographed under a microscope, and the fiber lengths of the reinforcing fibers are measured from the microscope photograph using commercially available image analysis software. The fiber lengths of 100 arbitrarily selected reinforcing fibers are measured, and the average value is taken as the average fiber length of the reinforcing fibers. If there are not 100 or more reinforcing fibers in the obtained microscope photograph, a new area is photographed under the microscope until the number of reinforcing fibers reaches 100 or more.

[0029] The fiber volume content of the composite material powder (B) is preferably 10 to 90 volume %, more preferably 30 to 60 volume %, and even more preferably 40 to 50 volume %. When a load is applied to the block member, the load is easily transmitted to the reinforcing fibers, and the strength of the block member is further improved.

[0030] The fiber volume content of the composite material powder (B) can be calculated by the following formula (1). Fiber volume content (volume%) = (fiber volume per unit volume (cm 3 / cm 3 ) / volume (cm) of composite powder (B) per unit volume 3 / cm 3 ))×100 (1) The volume of the composite material powder (B) in the block member is the volume of the composite material powder (B) added during molding. The reinforcing fibers can be extracted from the block material by, for example, subjecting the block material to a heat treatment at 250 to 550°C for about 7 hours and removing components contained in the block material other than the reinforcing fibers in a furnace.

[0031] The content of the composite material powder (B) is preferably 1 to 30% by mass, more preferably 10 to 25% by mass, and even more preferably 15 to 20% by mass, relative to the total mass of the block member. When the content of the composite material powder (B) is equal to or greater than the above-mentioned lower limit, the strength of the block member is further improved. When the content of the composite material powder (B) is equal to or less than the above-mentioned upper limit, the fluidity at the time of melting is less likely to decrease when preparing the resin composition (x) described below, and good moldability can be maintained. In addition, the specific gravity and production costs of the block member, which is a molded product of the resin composition (x), can be reduced.

[0032] <Compatibilizer (C)> When the block member contains the compatibilizer (C), the compatibility between the polypropylene (A) and the composite material powder (B) increases, and they become more easily adhered to each other, thereby improving moldability. Examples of the compatibilizer (C) include modified polyolefins, chlorinated polyolefins, etc. Among these, modified polyolefins are preferred. The compatibilizer (C) may be used alone or in combination of two or more kinds.

[0033] Examples of modified polyolefins include acid-modified polyolefins such as maleic anhydride-modified polyolefins, maleic acid-modified polyolefins, and (meth)acrylic acid-modified polyolefins; silane-modified polyolefins, etc. Among these, silane-modified polyolefins are preferred from the viewpoint of their low water absorption. The modified polyolefin may be used alone or in combination of two or more kinds.

[0034] Silane-modified polyolefin is a resin in which polyolefin is modified with a silane compound. Examples of silane-modified polyolefins include silane-grafted polyolefins obtained by mixing a polyolefin, a silane compound, and a peroxide at a temperature equal to or higher than the melting point of the polyolefin to graft the silane compound onto the polyolefin; and silane-copolymerized polyolefins obtained by copolymerizing ethylene with an ethylenically unsaturated silane compound.

[0035] Examples of polyolefins include polyethylene, polypropylene, ethylene-vinyl acetate copolymers, and ethylene-α-olefin copolymers. The ethylene-α-olefin copolymer is particularly preferably a copolymer in which ethylene is copolymerized with an α-olefin such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, or 1-octene at a ratio of about several mol %.

[0036] Examples of the silane compound include vinyltriethoxysilane, vinyltrimethoxysilane, and vinylmethyldimethoxysilane. The silane compound may be used when obtaining a polyolefin by polymerization reaction, or may be reacted with the polyolefin after the polyolefin has been obtained by polymerization reaction.

[0037] Examples of the ethylenically unsaturated silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinylacetoxysilane, and γ-methacryloxypropylmethyldimethoxysilane.

[0038] The compatibilizer (C) may be a commercially available product, such as those manufactured by Mitsubishi Chemical Corporation under the trade names "Linkron" and "Modic," Mitsui Chemicals, Inc. under the trade names "Admer" and "Hiwax," Sanyo Chemical Industries, Ltd. under the trade name "UMEX," NOF Corporation under the trade name "Modiper," Japan Polyethylene Corporation under the trade name "Rexpearl," DuPont under the trade name "FUSABOND," and Borealis under the trade name "HE2545."

[0039] The content of the compatibilizer (C) is preferably 0.1 to 5 mass% relative to the total mass of the block member, more preferably 0.5 to 3 mass%, and even more preferably 1 to 2 mass%. When the content of the compatibilizer (C) is equal to or greater than the lower limit, the compatibility between the polypropylene (A) and the composite material powder (B) is enhanced, the adhesion between them is improved, and the strength of the block member is increased. When the content of the compatibilizer (C) is equal to or less than the upper limit, the brittleness of the block member is reduced.

[0040] <Optional ingredients> The optional components are components other than the polypropylene (A), the composite material powder (B), and the compatibilizer (C). Examples of the optional components include heat stabilizers, light stabilizers, impact modifiers, flame retardants, release agents, sliding agents, fluorescent brighteners, colorants, fluorescent dyes, inorganic fluorescent materials, antistatic agents, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents, flow modifiers, radical generators, infrared absorbers (heat ray absorbers), photochromic agents, fillers other than the composite material powder (B), neutral paper, and paints. The optional components may be used alone or in combination of two or more.

[0041] The content of the optional components is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less, based on the total mass of the block member.

[0042] <Manufacturing method> The block member can be obtained by molding, for example, a resin composition (x) containing polypropylene (A), composite material powder (B), and a compatibilizer (C), and optionally any other components, into a predetermined shape. The block member thus obtained is a molded article of the resin composition (x). It is preferable to classify the composite material powder (B) in advance so that the average fiber length of the reinforcing fibers contained in the composite material powder (B) falls within the above-mentioned range.

[0043] The resin composition (x) can be obtained, for example, by mixing polypropylene (A), composite material powder (B), and compatibilizer (C), and, if necessary, optional components, using a mixing device such as a V-type blender or a Henschel mixer, and then granulating the resulting mixture if necessary, melt-kneading it using a melt-kneading device such as a twin-screw extruder, and pelletizing it using a cutting device such as a pelletizer.

[0044] The method for molding the resin composition (x) is not particularly limited, but examples thereof include extrusion molding, calendar molding, injection molding, roll molding, compression molding, and blow molding.

[0045] The block member may be a foamed material. A foamed block member is also referred to as a "foamed block member." When a foam block member is produced, the resin composition (x) contains a foaming agent. In consideration of foaming properties, the foaming agent can be used in an appropriate content.

[0046] Examples of the blowing agent include water, organic halogen compounds, etc. Among these, water is preferred from the viewpoint of easy availability and excellent convenience. The foaming agent may be used alone or in combination of two or more kinds.

[0047] The organic halogen compound may be an organic halogen compound in which all of the hydrogen atoms are substituted with halogen atoms, or an organic halogen compound in which some of the hydrogen atoms are substituted with halogen atoms. Examples of the organic halogen compounds include organic chlorine compounds, organic fluorine compounds, organic bromine compounds, and organic iodine compounds.

[0048] Examples of the organic chlorine compounds include saturated organic chlorine compounds such as dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride; and unsaturated organic chlorine compounds. Examples of organic fluorine compounds include hydrofluorocarbons (e.g., difluoromethane, 1,1,1,2,2-pentafluoroethane, 1,1,1-trifluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 1,1,1,2,2 saturated organic fluorine compounds such as 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene (E and Z isomers), 1,1,1,4,4,4-hexafluoro-2-butene (E and Z isomers), etc.; unsaturated organic fluorine compounds such as 1,2-dichloro-1,2-difluoroethene (E and Z isomers), hydrochlorofluoroolefins (e.g., For example, 1-chloro-3,3,3-trifluoropropene (E and Z isomers), 1-chloro-2,3,3-trifluoropropene (E and Z isomers), 1-(4)chloro-1,3,3-trifluoropropene (E and Z isomers), 2-chloro-1,3,3-trifluoropropene (E and Z isomers), 2-chloro-2,2,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene, 3-chloro-1,2,3-trifluoropropene (E and Z isomers), and compounds having a chlorine atom, a fluorine atom, and a double bond, such as 3-chloro-1,1,2-trifluoropropene, 3,3-dichloro-3-fluoropropene, 1,2-dichloro-3,3,3-trifluoropropene (E and Z isomers), 2-chloro-1,1,1,4,4,4-hexafluoro-2-butene (E and Z isomers), and 2-chloro-1,1,1,3,4,4,4-heptafluoro-2-butene (E and Z isomers).

[0049] Among these, from the viewpoint of excellent foaming properties, the organic halogen compound is preferably an organic chlorine compound or an organic fluorine compound, and more preferably hydrochlorofluoroolefin, hydrofluorocarbon, or hydrofluoroolefin.

[0050] The expansion ratio of the foamed block member is preferably 0.1 to 10 times, more preferably 1 to 5 times. The expansion ratio of the foamed block member can be adjusted by the type or amount of polypropylene (A), the type or amount of foaming agent, production conditions, and the like. The expansion ratio of the foamed block member is calculated by the formula: expansion ratio = y / x, where x is the specific gravity of the foamed block member and y is the specific gravity of the non-foamed block member.

[0051] <Action and effect> The block member of the present invention described above contains the composite material powder (B) and therefore has high strength and excellent durability. If recycled polypropylene (A) is used as the polypropylene (A) and chips of a fiber-reinforced composite material or pulverized material of used fiber-reinforced composite material is used as the composite material powder (B), the environmental load can be reduced and costs can be reduced.

[0052] <Application> The block members are suitable for use as temporary road materials, rainwater storage materials (for example, rainwater storage tanks, rainwater infiltration tanks, etc.), and the like. In addition to the above, the block members can also be used for applications such as buildings, vehicles and ships, railway facilities, water treatment facilities, factory facilities, fisheries and aquaculture facilities, electrical equipment, sports and park facilities, and civil engineering sites. The block members are suitable for use in buildings, for example, as balconies, flooring materials, foundations, beams, joists, posts, roofs, and battens. The block members are suitable for use in vehicles or ships, for example, as joists, FFU ships, decks, bulkheads, truck beds, bridges, and the like. The block members are suitable for use in railway facilities, for example, as sidewalk boards, protective boards for large three-sail rails, platforms, sleepers (bridges, branch, regular, short), etc. The block members are suitably used in water treatment facilities, for example, as covers, stoppers, stoppers, flocculator blades, doors, louvers, flow straightening plates, diversion plates, partition plates, inclined plates, and the like. The block members are suitable for use in factory facilities, for example, as floorboards, walkways, pit covers, chemical tanks, water tanks, workbenches, stands, joists, pallets, freezers, etc. The block members are suitable for use in aquaculture facilities, such as hatchery tanks, farm tanks, live fish tanks, walkways, etc. The block member is suitable for use in electrical equipment, for example, as a cleat, a pipe pillow, etc. The block members are suitable for use in sports and park facilities, for example, as pergolas, bridges, signboards, gazebos, back screens, tennis practice boards, scoreboards, floating piers, suspension bridges, promenades, ski cores, water wheels, and pool members. The block members are suitable for use at civil engineering sites, for example, as pressure plates, SEW earth retaining walls, etc. [Example]

[0053] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0054] [Measurement and Evaluation] <Mechanical strength evaluation> (Measurement of flexural modulus and flexural strength) A test piece measuring 80 mm (length) x 10 mm (width) was cut out from the block material. The resulting test pieces were measured for flexural modulus (MPa) and flexural strength (MPa) at 23°C in accordance with JIS K 7171:2022. The flexural modulus and flexural strength of each of the five test pieces were measured, and the arithmetic mean values ​​were taken as the flexural modulus and flexural strength of the block member, respectively.

[0055] (Measurement of tensile strength) A type 1B series A test piece (dumbbell test piece) specified in JIS K 7164:2005 was cut out from the block member. The tensile strength (MPa) of the obtained test piece was measured in accordance with JIS K 7164:2005 under the conditions of a chuck distance of 110 mm, a temperature of 23°C, and a tensile speed of 25 mm / min. The tensile strength of the five test pieces was measured, and the arithmetic mean value was taken as the tensile strength of the block member.

[0056] [Example 1] <Production of composite material powder (B)> The powder (grinding dust) generated when the surface of a urethane resin molded product (recycled material, a resin molded product containing a cured product of a urethane resin composition (b1) containing a polyol and diphenylmethane diisocyanate, and glass fiber, fiber volume content 30 to 70% by volume) was sanded was classified to obtain a composite material powder (B) containing a cured product of the urethane resin composition (b1) and glass fiber. A sieve with a mesh size of 3 mm was used for the classification. The average fiber length of the glass fibers in the composite powder (B) was 110.89 μm.

[0057] The average fiber length of the glass fibers was measured as follows. Specifically, the glass fibers contained in the composite material powder (B) were photographed under a microscope, and the fiber lengths of the glass fibers were measured from the microscope photograph using commercially available image analysis software. The fiber lengths of 100 randomly selected glass fibers were measured, and the average value was taken as the average fiber length of the glass fibers.

[0058] <Manufacturing of block components> As the polypropylene (A), a product name "Novatec PP BC 3LS" manufactured by Japan Polypropylene Corporation was used. As the compatibilizer (C), a silane-grafted modified polyolefin (trade name "Linkron XPM800HM" manufactured by Mitsubishi Chemical Corporation) was used. 35.7 parts by mass of polypropylene (A), 60 parts by mass of composite material powder (B), and 4.3 parts by mass of compatibilizer (C) were fed into a twin-screw extruder and melt-kneaded to prepare pellets of resin composition (x). 30.4 parts by mass of the obtained pellets of resin composition (x) and 69.6 parts by mass of polypropylene (A) were fed into an injection molding machine, and a molded block member having a length of 994 mm, a width of 994 mm, and a thickness of 220 mm was obtained at a cylinder temperature of 40 to 210°C and a mold temperature of 60°C. The mechanical strength of the resulting block member was evaluated, and the results are shown in Table 1.

[0059] [Examples 2 to 16] Block members were produced in the same manner as in Example 1, except that the grinding chips of the urethane resin molded body were classified so that the average fiber length of the glass fibers in the composite material powder (B) would be the value shown in Table 1, and the mechanical strength was evaluated. The results are shown in Table 1.

[0060] [Comparative Example 1] A block member was produced in the same manner as in Example 1, except that polypropylene (A) was fed to the injection molding machine instead of resin composition (x), and the mechanical strength was evaluated. The results are shown in Table 1.

[0061] [Table 1]

[0062] As shown in the results in Table 1, the block members obtained in each example had high flexural modulus, flexural strength and tensile strength, and were shown to be excellent in durability. On the other hand, the block member obtained in Comparative Example 1, which did not contain the composite material powder (B) and the compatibilizer (C), had low flexural modulus and flexural strength.

Claims

1. A composite material (A) comprising polypropylene (A), a composite material powder (B), and a compatibilizer (C), The composite material powder (B) is a powder of a fiber-reinforced composite material containing a cured product of a resin composition and reinforcing fibers.

2. 2. The block member according to claim 1, wherein the content of the composite material powder (B) is 1 to 30 mass % with respect to the total mass of the block member.

3. 3. The block member according to claim 1, wherein the reinforcing fibers contained in the composite material powder (B) have an average fiber length of 50 to 150 μm.

4. 3. The block member according to claim 1, wherein the content of the compatibilizer (C) is 0.1 to 5% by mass with respect to the total mass of the block member.

5. The block member according to claim 1 or 2, wherein the compatibilizer (C) comprises a silane-modified polyolefin.

6. 3. The block member according to claim 1, wherein the reinforcing fibers include glass fibers.

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