JP2014009539A - Compact for laying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact for laying utilizing a biomass effective for suppressing generation of carbon dioxide and excellent in manufacturability, laying workability, drainage efficiency, and antistatic performance.SOLUTION: A composition, which is subjected to a heat treatment in temperature range of 100 to 300°C and a pulverizing treatment and contains bamboo powder containing 80 mass% or more of components having fiber length of 1,000 μm or less and a plastic at a weight ratio ranging from 1:9 to 8:2, is fused and formed to obtain a compact for laying of which specific gravity is in the range of 1-2. The inventive compact for laying improves workability of laying, restoration, or the like of a compact and has a dust adherence suppression function.

Description

TECHNICAL FIELD The present invention relates to a molded body for laying on a floor in a room where side grooves installed along roads and railways, electronic device parts and automation devices are installed. Specifically, the present invention relates to a laying molded article that is molded from a composition containing bamboo powder and plastic that has been heat-treated in a specific temperature range, and has excellent laying workability, drainage efficiency, and antistatic performance.

It became clear that global warming due to the increase in carbon dioxide gas is the result of abuse of fossil resources, and for future descendants, it is necessary to reserve valuable fossil resources and effectively use renewable resources to produce carbon dioxide gas Preventing and further reducing the increase in production is a consensus among engineers involved in manufacturing. Effective use of biomass as a renewable resource and recycling of recovered resources are effective methods for preventing an increase in carbon dioxide gas.

A gutter is installed along the road for draining rainwater. In order to prevent the vehicle from taking a wheel in the side groove, the side groove is usually provided with a lid made of concrete or a metal lid having an excellent drainage function called grating. A concrete lid has excellent strength characteristics and can withstand the load of heavy vehicles, but has a problem in terms of drainage function. In addition, the lid itself is heavy and has a problem in workability. Metal grating is widely used as a gutter lid with excellent drainage function and workability, but because it is a metal material, it is prone to theft (Non-Patent Document 1), and the name of the municipality is stamped. Although the method and the method of fixing with a chain lock or a coupling tool are taken, it is a factor which reduces workability, such as manufacture and restoration.

In order to solve the above problems, plastic side groove covers and gratings have been developed. For example, Patent Document 1 discloses that the collected plastic is simply reused to produce a gutter lid. Patent Document 2 discloses a grating assembled with a pultruded member made of glass fiber reinforced plastic. However, the effect of reducing carbon dioxide gas is small in the cascade use of plastics derived from fossil resources.

On the other hand, in addition to the workability required for laying, the molded body for laying including the cover of the side groove is required to have a function such as, for example, a drainage function and dust-free adhesion. In particular, in factories and offices where electronic equipment parts and automation equipment such as computers are installed, in order to prevent the effects of static electricity and dust on electronic equipment parts, the floor material and the lid of the groove installed on the floor do not collect static electricity. There is a demand for a molded article that is excellent in antistatic property and does not adhere and has no tackiness. As a grating or flooring having such a function, a resin molded body in which carbon long fibers are laminated and impregnated and cured is disclosed (Patent Document 3). However, since this method uses an expensive carbon long fiber, there is a problem in moldability and poor versatility.

JP 2000-87437 A JP-A-5-209432 Japanese Patent Laid-Open No. 10-106788

Nikkei BP [edition], new product / new service The name of the local government is engraved on the lid for the ditch, theft control, Nikkei Construction, 433, 89, October 12, 2007

The problem to be solved by the present invention is to provide a molding for laying that is excellent in production, laying workability, drainage efficiency, and antistatic performance by using biomass effective for suppressing carbon dioxide generation. .

Heat-treated and pulverized in a specific temperature range, and contains bamboo powder containing 10% by mass or more of short fibers whose fiber length is 1000 μm or less and 80% by mass or more and plastic in a weight ratio of 1: 9 to 8: 2. The composition is melt-molded to obtain a molded article for laying having a specific gravity in the range of 1 to 2 and a surface resistivity of less than 10 ¹⁴ Ω / □.

Bamboo powder, which is a raw material for producing a laying molded body according to the present invention, exhibits better mechanical strength and antistatic performance when the aspect ratio is 5 or more.

Furthermore, by using a used recovered plastic having a specific gravity of 1.0 or more as a plastic as a raw material for producing a laying molded body according to the present invention, suppression of carbon dioxide generation and stability during drainage Will be improved.

Since the molding for laying according to the present invention is made from bamboo powder, which is biomass, it contributes to the reduction of net carbon dioxide gas according to the composition ratio of the bamboo powder components. The true specific gravity of the bamboo powder component is about 1.5. By blending the bamboo powder with the recovered plastic, the bamboo powder component contributes to an increase in the specific gravity of the composite and suppresses floating in the water when draining to the side groove.

Bamboo powder has a fiber length of 1000 μm or less in an amount of 80% by mass or more. Therefore, it can be applied to general melt molding means by blending with plastic, and mass molding is easy.

The compact produced by melt molding has a specific gravity in the range of 1 to 2, which is smaller than 2.3 to 2.4 for concrete compact and 7 to 8 for carbon steel. Workability such as is improved.

Furthermore, the molded body produced by melt molding has a surface resistivity of less than 10 ¹⁴ Ω / □, and has an antistatic function and a function of suppressing dust adhesion to the surface.

FIG. 1 is an optical micrograph of a 60 mesh pass component (bamboo powder). FIG. 2 is a fiber length distribution (size distribution) diagram of a 60 mesh path component measured by optical microscope observation. FIG. 3 is a photograph of a melt-molded product produced by injection molding. FIG. 4 is a fiber length distribution (size distribution) diagram of a 235 mesh path component measured by optical microscope observation. FIG. 5 is a fiber length distribution (size distribution) diagram of components between 235 and 140 mesh.

Embodiments of the present invention will be described below.

The bamboo according to the present embodiment contains, as main components, plant-derived cellulose fibers that are components that decompose at high temperatures, hemicellulose that decomposes at lower temperatures, and lignin that decomposes over a wide temperature range. Bamboo is homogeneous and present in large quantities, and has many fibrous components with excellent rigidity.

In a broad sense, bamboo is a general term for a species of woody stems such as Kimoto, from the family Gramineae. It is said that there are 600 kinds of bamboo grown in Japan. Typical examples include bamboo shoots, mosouchiku, and honeybees.

The type of bamboo used in the present embodiment is not limited. Further, in the present embodiment, bamboo means an overall body composed of trunks, branches, leaves, and roots, and in particular, trunks that contain a large amount of vascular sheaths rich in cellulose fiber components are suitable. .

Bamboo consists of cellulose, hemicellulose and lignin as its main constituents. Hemicellulose plays the role of an adhesive that binds cellulose and lignin or cellulose. This hemicellulose, for example, when raw bamboo powder is blended with a polymer material and molded at high temperature, decomposition products, so-called bamboo vinegar liquid components volatilize, not only lower the physical properties of the blend, but also work by odor Causes environmental degradation.

The bamboo powder according to the present embodiment is an aggregate of fine components obtained by pulverizing bamboo, and a short fiber component and a soft tissue in which cellulose crystals derived from a bamboo vascular sheath are gathered in a bundle. Coexists with particulate components derived from The shape as a whole is a powder containing 80% by mass or more of a component having a fiber length of 1000 μm or less. Preferably, the component having a fiber length of 1000 μm or less is 90% by mass or more, and more preferably, the component having a fiber length of 1000 μm or less is 95% by mass or more.

The mass% of the bamboo powder component according to the present embodiment is obtained by directly measuring fibers in a 1 cm × 1 cm image obtained by microscopic observation with adjustable magnification, and assuming a cylindrical shape from the fiber length and fiber diameter. Based on the fact that the volume produced is substantially proportional to the mass, it is obtained by measuring the cumulative frequency% of the fiber length and replacing it with mass%. In addition, the approximate value of the mass ratio of the powder component having a fiber length within a predetermined range can be easily obtained by a sieving method.

Since bamboo powder itself is infusible, there is a risk of hindering fluidity when melt-molding a mixed composition with plastic, and particularly high fluidity is required in injection molding. By setting the fiber length and mass range of the bamboo powder to the above ranges, fluidity at the time of melting is ensured.

The bamboo powder preferably has an average aspect ratio of 5 or more, more preferably 10 or more, and even more preferably 15 or more. There is no particular upper limit on the average aspect ratio, but if it exceeds 100, there may be a problem in moldability. Here, the aspect ratio is expressed as a ratio of fiber length / fiber diameter. A large aspect ratio means a more elongated fibrous form.

In general, bamboo powder having a large aspect ratio can exhibit a function as a reinforcing fiber when melt-molded together with plastic. Furthermore, contact between fibers tends to occur, and as a result, the antistatic performance can be further improved. In order to exhibit excellent charging performance, the average aspect ratio is preferably 5 or more, and more preferably 10 or more.

The method for producing bamboo powder according to the present embodiment is carried out by heat-treating bamboo at 100 to 300 ° C. and then pulverizing until the desired fiber length distribution is obtained.

The heat treatment according to the present embodiment means simple heating under heated air, heating under pressurized heating steam, heating under normal pressure heating steam, and the like. A method in which normal-pressure superheated steam heated to ˜300 ° C. is brought into contact with bamboo is a desirable method because heat treatment can be performed more effectively. Here, normal-pressure superheated steam is different from pressurized saturated steam obtained by heating in a constant volume state, and is obtained by further heating 100 ° C. steam in a state where it can be expanded. Water vapor.

As overheat treatment conditions, if the temperature is less than 100 ° C., the steam treatment effect of bamboo is small and the treatment takes a long time. Furthermore, when the temperature exceeds 300 ° C., the decomposition of the bamboo is likely to proceed more than necessary, the cellulose component is likely to deteriorate, and the contribution to the strength of the composite is reduced. As heating steam processing temperature, More preferably, it is 150-250 degreeC, More preferably, it is the range of 170-210 degreeC. The heat treatment time is inversely proportional to the treatment temperature, and requires a short time at a high temperature and a long time at a low temperature. Usually, it is carried out in the range of 30 minutes to 3 hours.

The bamboo that has been heat-treated is preferentially decomposed by the readily degradable hemicellulose component and partially volatilized and removed. Can be easily pulverized. The crushing and crushing can be appropriately performed using a generally known crushing / crushing apparatus. At this time, a two-stage pulverization process in which fine pulverization is performed after coarse pulverization may be performed. Examples of suitable crushing and crushing apparatuses include, for example, a hammer mill, a cutter mill, a pin mill, a crusher mill, a ball mill, a rod mill, a bar mill, a disk mill, a blade mill, a vibration mill, and a combination of two or more of these methods. This is a composite grinding method.

The pulverized bamboo powder can be used as it is as a component of the laying molded body according to the present embodiment, but in order to express more advanced characteristics, it is also preferable to control the particle size distribution by classification operation. Done. As a method used for the classification operation, a generally known classification method can be used without any limitation. Examples of suitable classification methods include, for example, sieve classification, airflow classification, vortex centrifugal classification, electrostatic separation classification, and the like, and various combinations of loads such as ultrasonic waves, longitudinal and transverse vibrations, and the like. There are different classification methods. Specifically, a vibration sieving device, a cyclone, an air classifier, a rotary drum electrostatic separator, and the like are suitable classifiers. Using these apparatuses, the bamboo component for the laying molded body according to the embodiment of the present invention is produced.

Next, the plastic material according to this embodiment will be described. The laying molded body according to the present embodiment (hereinafter, this may be simply referred to as a molded body) is made of bamboo powder and plastic material according to the present embodiment with a mass of 1: 9 to 8: 2. Molded from a composition blended in a ratio. The mass ratio of the bamboo powder and the plastic material according to this embodiment is more preferably 3: 7 to 7: 3, and further preferably 4: 6 to 6: 4.

If the mass ratio of the bamboo powder is less than 10%, not only the carbon dioxide gas reducing effect is small, but also the specific gravity increasing effect of the molded body by the bamboo powder is reduced. Furthermore, there exists a possibility that the antistatic performance based on bamboo powder may not be expressed effectively. On the other hand, if it exceeds 80%, the melt moldability is lowered, and even if it can be molded, there is a risk that the mechanical strength of the obtained molded product is lowered.

As the plastic material according to the present embodiment, any plastic material that can be combined with bamboo powder can be used without any limitation. In particular, a thermoplastic resin is more suitably used because it can produce a molded article with higher designability by melt molding.

As the thermoplastic resin, any resin that can be combined with bamboo powder can be used without any limitation. Examples of suitable thermoplastic resins include polyolefins such as polyethylene and polypropylene; polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene- (AS) resin, methyl methacrylate-butadiene-styrene (MBS) resin Styrenic resins such as: Aromatic polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); Aromatic polycarbonates such as bisphenol A type polycarbonate (PC); Nylon-6, Nylon-6, 6, etc. Polyamides of the following: Aliphatic polyesters such as polylactic acid, polycaprolactone, poly (3-hydroxybutyric acid), polytetramethyl glycolide, polyglycolic acid and the like. Among these thermoplastic resins, polyolefins are available from the viewpoint of availability and moldability, and styrene-based trees such as ABS resin and PET from the point that the specific gravity is greater than 1 and excellent in impact resistance. Particularly suitable are aromatic polyesters such as PC and aromatic polycarbonates such as PC. These thermoplastic resins may be used alone or in combination of two or more.

In addition to the thermoplastic resin, a thermoplastic prepolymer of a thermosetting resin can be used. Typical prepolymers of thermosetting resins include prepolymers such as epoxy resins, unsaturated polyester resins, silane-crosslinked polyethylene, alkyd resins, melamine resins, polyurethane, and crosslinked rubber. Among these prepolymers of thermosetting resins, prepolymers such as epoxy resins, polyurethanes, and unsaturated polyester resins are preferable because they can be easily combined with the bamboo powder according to the present invention.

The plastic material according to the present embodiment is preferably used recovered plastic from the viewpoint of suppressing the generation of carbon dioxide gas. As such a recovered plastic, a plastic material that is recovered and sorted by the Containers and Packaging Recycling Law, the Home Appliance Recycling Law, the Automobile Recycling Law, and the Effective Resource Utilization Promotion Law is suitably used.

As the melt molding method of the molded body according to the present embodiment, any known method can be used without any limitation as long as the bamboo powder can be uniformly dispersed in the thermoplastic resin. For example, a melt kneading method in which a thermoplastic resin is melted by heat and kneaded while applying shear stress to the bamboo powder, a solution in which the thermoplastic resin is dissolved in a solvent, the bamboo powder is added and dispersed, and then the solvent is vaporized and removed. There are a mixing method, a calender molding method in which a thermoplastic resin is softened on a heated roll, bamboo powder is added thereon, and kneaded while being pressed by a hot roll. Among these compounding methods, the melt-kneading method is most preferable in terms of efficiency and versatility.

Specific examples of the melt-kneading method include an injection molding method using an injection molding machine, an extrusion molding method using an extrusion molding machine, and a blow molding method using a blow molding machine. Using the sheet-like molded body as a raw material, deep drawing by a vacuum molding method using a vacuum molding machine or a compression molding method using a compression molding machine is preferably used. Among these molding methods, the injection molding method and the extrusion molding method are more preferably used from the viewpoints of versatility and expandability.

Injection molding is a method to obtain a molded product by injecting and injecting heat-melted material into a mold cavity, and cooling and solidifying it. Through the parts called sprue and runner, the mold of the molded product is obtained. The molten bamboo powder-containing resin melt is filled into the cavity. Here, since bamboo powder does not melt, a thermoplastic resin excellent in fluidity is selected when performing injection molding that requires melt fluidity.

Extrusion molding is a molding method in which a material melted and mixed by shearing stress and heat generated by the rotation of a screw in a heated cylinder is cooled and solidified while being extruded from a die extrusion port at a constant speed. Since high fluidity like injection molding is not required, a high-molecular weight thermoplastic resin having a high viscosity so as not to be deformed after being extruded from the extrusion port is selected. Furthermore, in extrusion molding, kneading with a screw is effectively performed. There are various screw shapes and directions of rotation, which can be selected according to the purpose of use. In the production of a laying molded body, in order to further increase the degree of kneading, kneading with a biaxial co-rotating screw is a more preferable method.

In the method for producing a molded body according to the present embodiment, for example, when molding is performed using an injection molding machine, high melt fluidity is required, and a large size infusible is passed through a screen before filling into a mold. In order to filter the material, it is more effective for the moldability that the fiber length of bamboo powder is distributed more in the relatively short direction. On the other hand, when a molded body is molded using an extrusion molding machine, bamboo powder containing a long fibrous component is oriented and flows in the molten thermoplastic resin. Therefore, as a result, a composite containing an oriented fibrous bamboo powder is obtained, and an improvement in mechanical properties due to fiber reinforcement is easily manifested, and this is a preferred embodiment of the production method.

In the case of using a prepolymer of a thermosetting resin instead of a thermoplastic resin, the above-described production method can be used, but at this time, a prepolymer of bamboo powder and a thermosetting resin, and a curing agent as necessary. A molded product having excellent mechanical strength can be obtained by melt-molding the mixed composition under conditions where the curing reaction does not proceed, and then curing the mixture by stimulation such as heating, water vapor, or light irradiation.

The specific gravity of the molded body according to the present embodiment is in the range of 1-2. The true specific gravity of the bamboo powder component is about 1.5, and the specific gravity of the composite is increased by blending the bamboo powder with the plastic material, so that it can be prevented from floating in the water when draining into the side groove.

As a plastic material blended with bamboo powder, styrene-based trees such as ABS resin, aromatic polyesters such as PET, and aromatic polycarbonates such as PC are particularly preferred because the specific gravity is greater than 1 and excellent in impact resistance. Preferably used. These thermoplastic resins may be used alone or in combination of two or more. Moreover, if it is the said resin collect | recovered and fractionated with implementation of the container packaging recycling law, the household appliance recycling law, and the automobile recycling law, it is more preferably used from a viewpoint of carbon dioxide generation suppression.

For the purpose of increasing the specific gravity of the molded body, it is also preferable to add an inorganic filler. As the inorganic filler, as long as it does not affect the bamboo powder or the plastic material, a generally known inorganic filler can be added without any limitation for the purpose of increasing the specific gravity. As inorganic fillers that are preferably used, calcium carbonate, magnesium carbonate, talc, mica, silica, sand and the like are used. A preferable addition amount of these inorganic fillers is in the range of 1 to 100% by mass with respect to the plastic material. Within this mass range, the specific gravity can be increased without significantly sacrificing melt moldability and mechanical properties.

By the method for manufacturing a laying molded body according to the present embodiment described above, a molded body having excellent melt moldability, mechanical properties, and antistatic properties can be efficiently obtained.

When the molded body according to the present embodiment is laid on a side groove installed along a road or a railroad and an indoor floor where electronic equipment parts and automation equipment are installed, a corresponding physical load is applied. The molded body has sufficient durability against the load. The largest load that can be applied is when the weight of the vehicle is loaded. For example, when a half load of a vehicle weight of 20 t is hung by a width of 10 cm, the load to be endured by a width of 1 cm is 1000 kg, and when the thickness of the molded body is 5 cm, the bending load applied per cm ² is about 20 MPa. It is. Accordingly, the load resistance required for the molded body is a bending strength of 20 MPa or more, and the bending strength of the molded body of the present invention is 20 MPa or more as shown in the Examples.

The bending strength of the molded body is evaluated by the following method. After making the melt-molded body of bamboo powder and plastic material into a pellet form, a test piece for a bending test is prepared using an injection molding machine, and the bending strength is obtained according to JIS-K-7171.

Although the mechanism of the antistatic function expression exhibited by the molded body according to the present embodiment is not yet clear, as shown in the examples described later, the laying molded body obtained by adding bamboo powder to the plastic material, The surface resistivity is below 10 ¹⁴ Ω / □, more preferably below 10 ¹³ Ω / □. The surface resistivity of the bamboo powder composite is reduced according to the amount of bamboo powder added.

The surface resistivity is measured according to JIS-K-6911. In addition to surface resistivity, an ash test is a simple method for evaluating antistatic properties, which is determined by the distance in the height direction where tobacco ash begins to adhere. The ash test is a method for evaluating the height at which a charged ash sample comes close to the top of the tobacco ash and the tobacco ash begins to adhere (this is defined as the deposition distance). The smaller the adhesion distance, the higher the antistatic property. The molded body obtained by adding bamboo powder to the plastic material preferably has an adhesion distance of less than 18 cm, more preferably less than 10 cm.

From the above, the molded body for laying according to the present embodiment can be suitably used for applications laid on the floor in the room where the side groove and electronic equipment parts and automation equipment installed along the road and railway are installed. it can.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, these examples do not limit the scope of the present invention.

<Manufacture example 1 of bamboo powder> Miso bamboo (diameter: about 12 cm, length: about 40 cm, weight: about 1 kg) is placed in a superheated steam treatment apparatus manufactured by Naomoto Kogyo Co., Ltd. with the following specifications, and superheated steam treatment is performed at 210 ° C. for 3 hours. Went. In addition, as a comparative example, crushing and fine crushing tests were also performed on the scorpion bamboo (the above dimensions) not subjected to superheated steam treatment using the same apparatus. The treated Sosou bamboo was taken out and coarsely pulverized at 7000 rpm using the following coarse and fine pulverizer, and further pulverized at 7000 rpm. Further, bamboo powder having a 60 mesh (aperture 250 μm) pass was produced using the following sieve device. Specification of superheated steam treatment device: Steam generation part: Heater capacity 6.3 kW Equivalent evaporation 9.45 kg / h Maximum operating pressure 0.11 MPa Treatment tank: Heater capacity 8 kW Internal dimensions W590 × D385 × H555 mm Specification of grinding device: Coarse crushing: HM-5 manufactured by Nara Machinery Co., Ltd. Fine grinding: Specifications of free crusher M-2 manufactured by Nara Machinery Co., Ltd. Shaker MVS-I

<Measurement of Fiber Length Distribution and Average Aspect Ratio of Bamboo Powder> The fiber length, fiber diameter, and average aspect ratio of bamboo powder were measured using the following optical microscope. The magnification of the optical microscope was changed according to the fiber length size of the bamboo powder. Optical microscope: VH-5000 type manufactured by Keyence Corporation Fig. 1 shows an optical micrograph of a 60 mesh path component (bamboo powder), and Fig. 2 shows a fiber length distribution histogram of the 60 mesh path component.

From the optical micrograph of the bamboo powder in FIG. 1, it can be seen that the bamboo powder that has been subjected to the steam treatment and the pulverization treatment is a mixture of short fiber-like components and irregular particulate components. The single fiber component is derived from a vascular sheath made of cellulose crystals, and the irregular particulate component is derived from a flexible structure. From the fiber length distribution observation result of FIG. 2, it was found that the 60 mesh pass component reached 90% by mass of the component having a fiber length of 1000 μm or less. As described above, the presence of a component having a fiber length equal to or larger than the mesh size while passing through the sieve of 60 mesh (mesh size 250 μm) means that the fiber passes between the mesh sizes in the longitudinal direction. doing. The average aspect ratio of the 60 mesh path component measured by observation with an optical microscope was 8.35.

(Melt Molded Production Examples 1-2) Bamboo powder produced in Production Example 1 and polypropylene (PP) (Novatech PP FY-6 manufactured by Nippon Polypropylene Co., Ltd.) were used in a mass ratio of 20/80 and 50/50 (wt% / wt%), and 1 wt% of anhydrous maleated PP was further added for dry mixing. The uniformly mixed sample is supplied to a twin-screw kneading extruder, and predetermined heating conditions (hopper temperature 80 ° C., screw left 190 ° C., screw right 200 ° C., outlet 210 ° C., screw rotation speed 15 rpm, residence time in the screw about 5 minutes) ) And was extruded from a die at the tip to produce a bamboo-PP composite strand-shaped molded body. The strand-shaped molded body was cut into pellets and injection molded at 210 ° C. using an IMC-18D1 type simple injection molding machine manufactured by Imoto Seisakusho, and a rectangular parallelepiped melt-formed body (length: 20 mm, width: 5 mm, thickness) : 2 mm). Further, a rectangular parallelepiped injection-molded body (FIG. 3) was prepared with the intention of a side groove lid as a laying molded body.

(Melt Molded Manufacturing Examples 3 to 4) The bamboo powder prepared in Production Example 1 and acrylonitrile-butadiene-styrene resin (ABS) (manufactured by UMG-ABS, MFR = 35.8) were used in a mass ratio of 20/80 and 50 /. 50 (wt% / wt%) was mixed. The uniformly mixed sample is supplied to a twin-screw kneading extruder, and predetermined heating conditions (hopper temperature 110 ° C., screw left 200 ° C., screw right 210 ° C., outlet 200 ° C., screw rotation speed 50 rpm, residence time in the screw about 3 minutes) ) And was extruded from a die at the tip to produce a bamboo-PP composite strand-shaped molded body. The strand-shaped molded body was cut into pellets and subjected to injection molding at 220 ° C. using an IMC-18D1 type simple injection molding machine manufactured by Imoto Seisakusho, and a rectangular parallelepiped melt-molded body (length: 20 mm, 20 mm, width: 5 mm, (Thickness: 2 mm).

(Molded Molded Production Examples 5 to 6) The bamboo powder produced in Production Example 1 and bisphenol A type polycarbonate resin (PC) (Mitsubishi Engineering Plastics Iupilon S-3000 MFR = 15) in a mass ratio of 20/80 And 50/50 (wt% / wt%). The uniformly mixed sample is supplied to a twin-screw kneading extruder, and predetermined heating conditions (hopper temperature 120 ° C., screw left 215 ° C., screw right 230 ° C., outlet 220 ° C., screw rotation speed 50 rpm, residence time in the screw about 3 minutes) ) And was extruded from a die at the tip to produce a bamboo-PP composite strand-shaped molded body. The strand-shaped molded body was cut into pellets and injection molded at 250 ° C. using an IMC-18D1 type simple injection molding machine manufactured by Imoto Seisakusho, and a rectangular parallelepiped melt-formed body (length: 20 mm, width: 5 mm, thickness) : 2 mm).

(Molded Mold Production Example 7) The bamboo powder produced in Production Example 1, the ABS resin, and the PC resin were mixed at a mass ratio of 20/40/40 (wt% / wt% / wt%). The uniformly mixed sample is supplied to a twin-screw kneading extruder, and predetermined heating conditions (hopper temperature 120 ° C., screw left 215 ° C., screw right 230 ° C., outlet 220 ° C., screw rotation speed 50 rpm, residence time in the screw about 3 minutes) ) And was extruded from a die at the tip to produce a bamboo-PP composite strand-shaped molded body. The strand-shaped molded body was cut into pellets and subjected to injection molding at 250 ° C. using an IMC-18D1 type simple injection molding machine manufactured by Imoto Seisakusho, and a rectangular parallelepiped melt-molded body (length: 20 mm, width: 5 mm, thickness) : 2 mm).

<Measurement of Specific Gravity of Melt Molded Body> The measurement of the specific gravity of the melt molded body of the rectangular parallelepiped produced in the melt molded body production examples 1 to 7 is the weight accompanying immersion of the molded body in distilled water having a constant volume at 23 ° C. The specific gravity was measured from the comparison between the increase amount and the volume increase amount. The obtained results are shown in Table 1. <Measurement of Bending Strength of Melt Molded Body> The bending strength test of the cuboid melt molded body manufactured in melt molded body manufacturing examples 1 to 7 is a bending test using an IMC-18E0 type tensile compression tester manufactured by Imoto Seisakusho. (Test speed: 10 mm / min). Bending strength and bending elastic modulus were calculated from the obtained stress-strain curve (s-s curve). The obtained results are also shown in Table 1.

As is clear from the results in Table 1, each of the melt-formed bodies had a specific gravity of 1.0 or more and a bending strength of 20 MPa or more.

<Manufacture example 2 of bamboo powder> Miso bamboo (diameter: about 12 cm, length: about 40 cm, weight: about 1 kg) is placed in a superheated steam treatment apparatus manufactured by Naomoto Kogyo Co., Ltd. with the following specifications, and subjected to superheated steam treatment at 220 ° C for 120 minutes went. The treated Sosou bamboo was taken out and crushed at 7000 rpm using the following coarse pulverizer, and then pulverized at 7000 rpm using a fine pulverizer. Furthermore, by using the following sieving apparatus, classification is performed using a sieve of 140 mesh (aperture 106 μm) and 235 mesh (aperture 63 μm), so that two types of components, a 235 mesh pass component and a component between 235 and 140 mesh, are obtained. Bamboo powder was prepared. Specification of superheated steam treatment device: Steam generation part: Heater capacity 6.3 kW Equivalent evaporation 9.45 kg / h Maximum operating pressure 0.11 MPa Treatment tank: Heater capacity 8 kW Internal dimensions W590 × D385 × H555 mm Specification of grinding device: Coarse crushing: HM-5 manufactured by Nara Machinery Co., Ltd. Fine grinding: Specifications of free crusher M-2 manufactured by Nara Machinery Co., Ltd. Moisture measuring device specification: Moisture meter MPC-120H manufactured by Shimadzu Corp. Specification of sieve device: Mini sieve manufactured by ASONE CORPORATION Shaker MVS-I

<Measurement of Fiber Length Distribution and Average Aspect Ratio of Bamboo Powder> Measurement of fiber length and measurement of average aspect ratio were performed using the following optical microscope. The magnification of the optical microscope was changed according to the fiber length size of the bamboo powder. Optical microscope: VH-5000 type manufactured by Keyence Co., Ltd. FIG. 4 shows a fiber length distribution (size distribution) diagram of a 235 mesh path component measured by observation with an optical microscope, and FIG. 5 shows two types of bamboo powder having a component between 235 and 140 mesh. The fiber length distribution (size distribution) figure of was shown.

From the fiber length distribution observation result of FIG. 4, it was found that the 235 mesh path component reached 100% by mass of the component having a fiber length of 1000 μm or less. From the fiber length distribution observation result of FIG. 5, the component between 235 and 140 mesh is 37% by mass of the component having a fiber length of 250 μm or less, the component of 500 μm or less is 80% by mass, and the component of 1000 μm or less is 100% by mass. I found out. As described above, a component having a fiber length larger than the mesh size is present in the mesh in the longitudinal direction while passing through the sieves of 235 mesh (aperture 63 μm) and 140 mesh (aperture 106 μm). Means to pass between. The average aspect ratio of the 235 mesh pass component measured by observation with an optical microscope was 3.0. On the other hand, the average aspect ratio of the components between 235 and 140 mesh was 10.0.

(Production Examples 8 to 13 of antistatic moldings) Two types of bamboo powders (components between 235 mesh pass and 235 to 140 meshes) obtained in Production Example 2 of bamboo powder and polypropylene (manufactured by Nippon Polypropylene Co., Ltd.) Novatec PP FY-6) is mixed with bamboo powder: polypropylene = 1: 9, 3: 7, 5: 5 (mass ratio), and this is a biaxial kneading extruder 160B with a vent manufactured by Imoto Seisakusho (rotating in the same direction) Using a biaxial screw, screw diameter: 15 mm, L / D: 25, vent port number: 1), melt-kneading was performed to produce a strand-shaped molded body. The melt-kneading conditions for compounding with polypropylene were carried out at a hopper lower temperature of 80 ° C., a barrel temperature of 190 ° C., a die temperature of 190 ° C., and a screw rotation speed of 15 rpm.

The strand-shaped molded body produced using the extruder was preheated at 190 ° C. for 3 minutes using a hot press apparatus IMC-180C manufactured by Imoto Seisakusho, and then pressurized at a pressure of 12 MPa for 5 minutes. From the obtained sheet having a thickness of about 0.6 mm, a sheet-like molded body having a size of 100 mm × 100 mm was cut out to measure the surface resistivity. Moreover, the polypropylene sheet of the same size was produced as a comparative example using the same hot press apparatus.

<Surface Resistivity Measurement of Sheet-Shaped Molded Body> Surface resistivity measurement was performed using HI-100 (Mitsubishi Chemical Co., Ltd.) as a probe in accordance with JIS-K-6911 (main electrode φ50 mm, guard inner diameter). φ53.2 mm), an applied voltage of 1000 v, an application time of 60 seconds, and a test temperature of 23 ° C. The measurement was performed 3 times or more for each compact sample, and the average surface resistivity was obtained. The results are shown in Table 2.

As is clear from the results in Table 2, it can be seen that by adding bamboo powder to polypropylene, the surface resistivity was 10 ¹⁴ Ω / □ or less, and the antistatic performance was significantly improved as compared with the polypropylene of the comparative example. . In addition, it was found that bamboo powder having a high average aspect ratio between 235 and 140 mesh exhibits better antistatic properties than bamboo powder having a low average aspect ratio and having a 235 mesh pass component.

Claims (5)

A composition containing bamboo powder and plastic in a weight ratio of 1: 9 to 8: 2 containing 80% by mass or more of short fiber having a fiber length of 250 μm or less and 10% by mass or more of short fibers ranging from 63 to 250 μm. A molding for laying, which is melt-molded and has a specific gravity in the range of 1 to 2. 2. The molded article for laying according to claim 1, wherein the bamboo powder has an aspect ratio of 5 or more. The molded article for laying according to claim 1 or 2, wherein the plastic is used recovered plastic and has a specific gravity of 1.0 or more. Bending test strength is 20 MPa or more, The molded object for laying according to claims 1 to 3. 5. The laying molded article according to claim 1, wherein the surface resistivity is less than 10 ¹⁴ Ω / □.