JP4306373B2 - Fiber reinforced plastic using plant fiber - Google Patents

Description

  The present invention relates to a fiber reinforced plastic containing a fiber as a reinforcing material in a plastic material.

  Conventionally, glass fibers having excellent strength have been used as reinforcing materials contained in fiber-reinforced plastics. However, when performing thermal recycling to recover thermal energy by burning fiber reinforced plastic using this glass fiber as a reinforcing material, because the glass fiber is an incombustible material, the combustion efficiency is damaged. There was a problem of lowering. There is also a problem that the residue after incineration increases. For this reason, in actuality, thermal recycling of fiber reinforced plastic using glass fiber as a reinforcing material is hardly performed, and it is currently disposed of in landfills.

In order to deal with such problems, fiber reinforced plastics using plant fibers as reinforcing materials have been proposed (see, for example, Patent Documents 1 and 2).
JP-A-5-92527 JP 2002-69208 A

  One of the plant fibers used as a reinforcing material for fiber reinforced plastics is lignocellulose fiber.

  Problems in using lignocellulosic fibers as a reinforcing material for fiber-reinforced plastic will be described with reference to FIGS. The lignocellulose fiber 1 is composed of a cell wall 2 which is a substantial part of the fiber and a cell lumen 3 which is a void. Because of having such a hollow structure, there is a possibility that when the plant fiber is combined with the plastic 4, the cell lumen may not be completely filled with the plastic due to the surface tension. This means that voids 5 are generated inside the material, and defects are generated in the material, so that the strength performance of the material is reduced (see FIG. 2).

  In addition, since plant fiber has lower strength than glass fiber, when the same amount of reinforcing material is included, fiber reinforced plastic using plant fiber has lower strength performance than fiber reinforced plastic using glass fiber. To do. As a means for solving this, it is conceivable to increase the content of plant fibers used as a reinforcing material. According to the composite law, the strength of the composite material increases as the reinforcing material content increases. However, plant fibers are bulky due to the presence of cell lumens. Therefore, it is difficult to uniformly mix with plastic in a state where the fiber content is increased.

  Furthermore, it has been confirmed that when plant fibers are simply mixed as a reinforcing material for fiber reinforced plastic, impact strength is low. In this regard, the mechanical properties of the fibers themselves are also related, but it is thought that there is little contact between the plant fibers.

This invention is made | formed in view of this reason, The place made into the objective is providing the plant fiber reinforced plastic excellent in the strength performance from the conventional fiber reinforced plastic which uses a vegetable fiber as a reinforcing material .

The invention according to claim 1 is a fiber reinforced plastic using a lignocellulosic fiber composed of a cell wall and a cell lumen as a reinforcing material, wherein the lignocellulosic fiber has a form of a fiber bundle, and oxalic acid The bond strength between single fibers is relaxed using any of ammonium, sodium hydroxide, chlorite, and hypochlorite, and beating is performed until the cell lumen disappears. It is characterized by. The cell lumen is desirably completely disappeared, but a slight cell lumen may partially remain.

In the invention according to claim 2, in the lignocellulose fiber, a part of cellulose microfibrils constituting the cell wall by beating treatment protrudes from the cell wall surface as whisker-like fibers.

The invention according to claim 3 is a method for producing a fiber reinforced plastic using a lignocellulose fiber composed of a cell wall and a cell lumen as a reinforcing material, wherein the lignocellulose fiber has a form of a fiber bundle. , Treatment to relax the bond strength between single fibers using any of ammonium oxalate, sodium hydroxide, chlorite, hypochlorite and beating until the cell lumen disappears Is a method for producing a fiber-reinforced plastic.

According to the fiber reinforced plastic according to claim 1, since the cell lumen of the lignocellulosic fiber as the reinforcing material is deformed to the extent that it disappears, there are few voids formed inside the material, and the strength performance is excellent. Yes. It is considered that the improvement in strength performance is also brought about by an improvement in adhesion between lignocellulose fibers by using lignocellulose fibers plasticized during deformation. Moreover, since the bulkiness which lignocellulose fiber has is eliminated, the composite with the plastic in the form which increased the amount of plant fiber rather than the conventional fiber reinforced plastic which uses a plant as a reinforcing material is attained. In addition, since any one of ammonium oxalate, sodium hydroxide, chlorite, and hypochlorite is used to loosen the bonds between single fibers, it is given to cellulose that bears the strength performance of the fibers. Damage can be reduced.

  According to the fiber reinforced plastic according to claim 2, since a part of the cellulose microfibril constituting the cell wall of the lignocellulose fiber is protruded from the cell wall surface as a whisker-like fiber, the effect of the invention of claim 1 is manifested. In addition, the adhesion between lignocellulose fibers is further improved. As a result, the strength of the fiber reinforced plastic is greatly improved. In particular, the impact strength is significantly improved.

According to the method for producing a fiber reinforced plastic according to claim 3, high strength performance is obtained by beating the lignocellulose fiber used as the reinforcing material of the fiber reinforced plastic to eliminate the cell lumen of the lignocellulose fiber. The fiber reinforced plastic which has can be provided. Moreover, since the process which loosens the coupling | bonding of the fiber of the fiber bundle comprised with the lignocellulose fiber is performed before performing a beating process, the effect of a beating process can be raised. In addition, by using any of ammonium oxalate, sodium hydroxide, chlorite, and hypochlorite in the process of loosening the bonds between single fibers, damage to the cellulose responsible for fiber strength is reduced. can do.

  Hereinafter, the present invention will be described based on embodiments. The fiber reinforced plastic according to the embodiment will be described with reference to FIGS. 3 and 4 show cross-sectional views of the fiber reinforced plastic. These consist of lignocellulosic fibers 1 and plastics 4 which are reinforcing materials.

  The following two types are mentioned as a composite method of a plant fiber and a plastic.

The first is a method in which plant fibers are molded into a sheet shape and the plant fiber sheets are combined with plastic. The sheet 1 made of lignocellulosic fibers having the form of this single fiber may be one sheet as shown in FIG. 3, may be three sheets as shown in FIG. There may be a plurality of sheets. The types of plastic to be combined will be described later. The plant fiber sheet combined as shown in FIGS. 3 and 4 is cured as necessary, and can be improved in strength performance and dimensional stability by heating and compression molding. Here, it is preferable that the mass ratio of the lignocellulose fiber 1 in the fiber reinforced plastic is in the range of 2 to 30%. When the lignocellulosic fiber 1 is 2% or more, the reinforcing effect is enhanced, and when it is 30% or less, the bond between the lignocellulose 1 and the plastic 4 is strengthened, and both have good characteristics as a fiber-reinforced plastic. Obtainable.

  The second is a method of forming a plant fiber mat (see FIG. 5) infiltrated with a resin from a uniform mixed solution consisting of a plant fiber and a resin solution by papermaking. The resin-impregnated vegetable fiber mat can be cured as necessary, and heated and compression molded to improve strength performance and stabilize dimensions.

  As the plastic 4, thermosetting resins such as unsaturated polyester, epoxy, phenol, and melamine, and thermoplastic resins such as polyethylene, polypropylene, polystyrene, saturated polyester, and ABS can be used, but are not limited thereto. is not. In addition, when a thermoplastic resin is used, it is possible to separate the lignocellulosic fiber and the plastic after molding and use, and there is an advantage that recycling becomes easy.

As the lignocellulosic fiber 1 to be used, those whose main components are cellulose and lignin can be used. Specifically, fibers collected from basts of hemp plants such as kenaf, flax, ramie, cannabis and jute, fibers collected from stem or leaf muscles of hemp plants such as Manila hemp and sisal hemp, wood Fiber. These fibers are composed of components such as hemicellulose and pectin in addition to cellulose and lignin. Among the fibers listed here, the fiber of hemp plant has a high ratio of cellulose, which is a source of fiber strength expression, of 60% or more compared with 30-50% of wood fibers, and has excellent strength as a fiber. Yes. In plant fibers, cellulose exists in the form of crystalline cellulose microfibrils in which a plurality of molecular chains are bound. Lignocellulose fibers are used in the form of a fiber bundle in which a plurality of single fibers are bound. Moreover, as a fiber bundle, length is long and the fiber of 20 mm or more is easily obtained by physical defibration.

The lignocellulosic fibers in the form of a fiber維束performs beating prior to forming the fiber sheet or fiber mat. The beating process is a process for applying compressive force and shear force to the fiber in the presence of moisture. The treatment is performed to such an extent that the lumen of the fiber disappears, and furthermore, the whisker-like fibers protrude from the cell wall. Devices used for the beating process include a beater and a PFI mill. By the beating treatment, part of hydrogen bonds between cellulose microfibrils constituting the cell wall of the fiber is cut, and the cohesive force between the microfibrils is reduced. The beating process results in plasticization of the fiber, and by applying a compressive force to the plasticized fiber, the voids in the fiber lumen are crushed. When moisture in the fiber is removed in this state, new hydrogen bonds are generated between the cellulose microfibrils, and the compression deformation applied to the fiber is fixed.

  As mentioned above, by eliminating the cell lumen of the lignocellulose fiber, the formation of voids derived from the cell lumen when the lignocellulose fiber and the plastic are combined is suppressed, and the fiber reinforcement has excellent strength performance. Can produce plastic.

  Moreover, since the bulkiness due to the cell lumen of the lignocellulose fiber is eliminated, more lignocellulose fibers can be used as a reinforcing material. This facilitates the design of a fiber reinforced plastic having excellent strength performance.

  Furthermore, since the plasticity of the lignocellulose fibers increases, the adhesion between the lignocellulose fibers inside the fiber reinforced plastic is dramatically improved. This increases the strength of the fiber reinforced plastic.

  Use of the beating process also improves the impact strength of the fiber reinforced plastic. This will be described with reference to FIG. As described above, the lumen of the lignocellulose fiber disappears by the beating process. When the beating treatment is further performed, the cohesive force between cellulose microfibrils constituting the lignocellulose fibers is remarkably reduced, and part of the cellulose microfibrils jumps out of the cell walls of the lignocellulose fibers as beard-like fibers 6. As a result, the surface area of the fiber is dramatically increased, and the contact surface between the lignocellulosic fibers in the fiber reinforced plastic is greatly increased. Thereby, when the fiber reinforced plastic which uses a lignocellulosic fiber as a reinforcing material receives external force and destruction of a fiber reinforced plastic arises, the bond between fibers is cut | disconnected in steps. As a result, the fracture proceeds with a large strain, and the impact strength is dramatically improved.

  Lignocellulose fibers having the form of fiber bundles are longer than lignocellulose fibers having the form of single fibers. In the fiber reinforced composite material, the longer the fiber length of the reinforcing material, the higher the reinforcing effect. Therefore, when using lignocellulose fiber as a reinforcing material, it may be advantageous to use lignocellulose fiber in the form of a fiber bundle. However, lignocellulosic fibers having the form of fiber bundles may not be able to fully enjoy the effect of the beating treatment. That is, when moisture does not sufficiently penetrate into the fiber bundle 7 and the plasticization of the fibers does not occur sufficiently, or when the deformation of the fibers is suppressed because the single fibers are constrained to each other, As shown in FIG. 7, even if the beating process is performed, the cell lumen 3 of the fiber may not completely disappear.

  As a solution to such a situation, it is effective to loosen the bond between the single fibers of the lignocellulose fiber bundle before performing the beating process. This will be described with reference to FIG. By creating the fiber bundle 8 in which the bonding strength between the single fibers is loosened, it becomes easy for moisture to penetrate into the fiber bundle 8. As a result, plasticization of the fiber bundle also occurs inside the fiber bundle. Moreover, since the restriction | limiting of single fibers is loose, a fiber bundle will be in the state which is easy to deform | transform. For this reason, the effect of the beating process is sufficiently expressed, and the cell lumen 3 is also easily lost during the process.

  The method for relaxing the bonding between single fibers is not particularly limited. As an example, the fiber bundle is chemically treated or disaggregated using ammonium oxalate, sodium hydroxide, chlorite, or hypochlorite. The method of doing is mentioned.

  In the lignocellulose fiber bundle, the chemical components that bind the single fibers are lignin, hemicellulose, and pectin. In the method by chemical treatment, lignin, hemicellulose, and pectin, which are components that adhere single fibers, are eluted and removed. Specific processing methods include a kraft pulping method in which pressure is heated with a mixed solution of sodium hydroxide and sodium sulfide, a soda pulping method, a sulfite pulping method, and the like, but the processing method is not particularly limited. As an example, the fiber bundle is first immersed in an aqueous sodium hypochlorite solution to remove lignin from the fiber bundle, and then the fiber bundle is ammonium oxalate to remove pectin contained in the hemp plant. A chemical treatment in which the fiber bundle is immersed in an aqueous solution of sodium hydroxide in order to remove the hemicellulose is mentioned. In this method, there is no need to apply pressure as in the kraft pulping method, soda pulping method, sulfite pulping method, etc., and processing under normal pressure is possible, so no equipment such as a digester is required. . Moreover, only the component which adhere | attaches a single fiber can be eluted and removed, without damaging the cellulose component which is supporting the strength expression of a lignocellulose fiber. The chemical treatment is not limited to the above treatment, and other chemicals having an action of defibrating plant fibers may be used.

  In the method using the disaggregation treatment, the fiber bundle is put into a disaggregator together with a large amount of water, and the fiber bundle solution is stirred. In the course of treatment, a shearing force acts between the single fibers, and the bonds between the single fibers are relaxed. In this treatment, since the total amount of lignin, hemicellulose, and pectin, which are components that adhere single fibers to each other, is not removed, lignocellulosic fibers can be obtained with high fiber bonding strength.

( Reference Example 1)
The bast portion, which is the outer skin portion of the kenaf stem, was alkali-digested to obtain a single fiber having an average length of 2.1 mm. The obtained kenaf single fiber was put into a standard disaggregator specified by JISP8220 (pulp-disaggregation method), and water was added so that the concentration of the single fiber suspension was 1.5%. The kenaf monofilament suspension was stirred up to a rotation index of 1200 times. Water was squeezed out until the concentration of the stirred single fiber solution reached 10%, and a beating process using a PFI mill was performed. The number of rotations was 5000 times. The kenaf monofilament subjected to the beating treatment until the cell lumen disappeared was dispersed again in water, poured into a sheet machine, drained, molded into a flat shape, and dried to prepare a monofilament sheet. Ten sheets of this monofilament sheet infiltrated with a liquid unsaturated polyester resin compound (SD-4200 manufactured by Matsushita Electric Works Co., Ltd.) were laminated to obtain a plate-shaped molding material. Furthermore, after this plate-shaped molding material was cured under the condition of 40 ° C. for 7 hours, it was compression-molded for 4 minutes with a hot plate press having a surface temperature of 135 ° C., and fiber reinforced having a shape of 300 mm in length and width and 5 mm in thickness. Got plastic. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.55, and the mass ratio of kenaf fiber was 25%.
( Reference Example 2)
In the same manner as in Reference Example 1, a kenaf monofilament having an average length of 2.1 mm was obtained. In the same manner as in Reference Example 1, the obtained kenaf monofilament was stirred with a standard disaggregator. Water was extracted until the concentration of the stirred pulp reached 10%, and a beating process using a PFI mill was performed. The number of rotations was 80000 times. A single fiber sheet was prepared from the kenaf single fiber subjected to the beating treatment in the same manner as in Reference Example 1. Ten sheets of this monofilament sheet impregnated with a liquid unsaturated polyester resin compound were laminated in the same manner as in Reference Example 1 to obtain a plate-shaped molding material. Further, curing and heating molding similar to those in Reference Example 1 were performed to form a fiber reinforced plastic having the same shape as in Reference Example 1. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.60 and the mass ratio of kenaf fiber was 25%. Moreover, as a result of observation with an optical microscope, the number of rotations of the beating process by the PFI mill was increased from that in Reference Example 1 and the conditions of the beating process were tightened. It was confirmed that many fibrils popped out. This was a phenomenon that was not observed from the fibers subjected to the beating treatment under the conditions of Reference Example 1.
(Example 1 )
A kenaf fiber bundle having an average fiber bundle length of 50 mm was obtained by cutting and defibrating the kenaf fiber bundle obtained from the bast that is the outer skin portion of the kenaf stem. In the same manner as in Reference Example 1, this fiber bundle was stirred by a standard disaggregator, and then water was extracted until the concentration of the fiber bundle solution reached 10%. Then, it used for the beating process by a PFI mill. The number of rotations was 80000 times. Further, in the same manner as in Reference Example 1, a fiber bundle sheet was prepared from the beef-treated kenaf fiber bundle. Ten sheets of this fiber bundle sheet impregnated with a liquid unsaturated polyester resin compound were laminated in the same manner as in Reference Example 1 to obtain a plate-shaped molding material. Further, curing and heating molding were performed in the same manner as in Reference Example 1 to form a fiber-reinforced plastic having the same shape. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.55, and the mass ratio of kenaf fiber was 25%.
(Example 2 )
In the same manner as in Example 1 , a kenaf fiber bundle having an average length of 50 mm was obtained. In order to loosen the cohesive force between the single fibers constituting the fiber bundle, the kenaf fiber bundle was treated with a mixed solution of sodium hydroxide and sodium sulfide under high temperature and high pressure. The treated kenaf fiber bundle was agitated by a standard disaggregator in the same manner as in Reference Example 1. Water was extracted until the concentration of the stirred fiber bundle solution reached 10%, and a beating process was performed using a PFI mill. The number of rotations was 80000 times. Moreover, the fiber bundle sheet | seat was created from the kenaf fiber bundle which performed the beating process similarly to the reference example 1. FIG. Ten sheets of this fiber bundle sheet impregnated with a liquid unsaturated polyester resin compound were laminated in the same manner as in Reference Example 1 to obtain a plate-shaped molding material. Further, curing and heating molding similar to those in Reference Example 1 were performed to form a fiber reinforced plastic having the same shape as in Reference Example 1. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.60 and the mass ratio of kenaf fiber was 25%.
(Example 3 )
In the same manner as in Example 1 , kenaf fibers having an average fiber bundle length of 50 mm were obtained. In order to loosen the cohesive force between the single fibers constituting the fiber bundle, treatment with ammonium oxalate and sodium hydroxide was performed. First, the kenaf fiber bundle was immersed in a dilute solution of ammonium oxalate and treated at a high temperature. After the treated fiber was washed with water, the kenaf fiber bundle was immersed in a dilute solution of sodium hydroxide and treated at a high temperature. The fiber bundle after the sodium hydroxide treatment was subjected to a stirring treatment with a standard disaggregator in the same manner as in Reference Example 1. In the same manner as in Reference Example 1 , water was squeezed out until the concentration of the stirred fiber bundle solution reached 10%, and a beating process using a PFI mill was performed. The number of rotations was 80000 times. A fiber bundle sheet was prepared from a kenaf fiber bundle subjected to beating treatment in the same manner as in Reference Example 1. Ten sheets of this fiber bundle sheet impregnated with a liquid unsaturated polyester resin compound were laminated in the same manner as in Reference Example 1 to obtain a plate-shaped molding material. Further, curing and heating molding similar to those in Reference Example 1 were performed to form a fiber reinforced plastic having the same shape as in Reference Example 1. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.60 and the mass ratio of kenaf fiber was 25%.
(Comparative Example 1)
In the same manner as in Reference Example 1, a kenaf monofilament having an average length of 2.1 mm was obtained. In the same manner as in Reference Example 1, a single fiber sheet was prepared from kenaf single fibers. Ten sheets of this monofilament sheet impregnated with a liquid unsaturated polyester resin compound in the same manner as in Reference Example 1 were laminated to obtain a plate-shaped molding material. Further, the same curing and heating molding as in Reference Example 1 was performed to form a fiber reinforced plastic having the same shape. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.50 and the mass ratio of kenaf fiber was 25%.
(Comparative Example 2)
A kenaf fiber bundle having an average fiber bundle length of 50 mm was obtained in the same manner as in Example 1 . This was arrange | positioned in the sheet form so that a fiber direction might be non-oriented, and the sheet | seat of the kenaf fiber bundle was obtained. Ten sheets of this kenaf fiber bundle sheet impregnated with a liquid unsaturated polyester resin compound in the same manner as in Reference Example 1 were laminated to obtain a plate-shaped molding material. Further, curing and heating molding were performed in the same manner as in Reference Example 1 to form a fiber-reinforced plastic having the same shape. As a result of measuring the basic physical properties of this fiber reinforced plastic, the specific gravity was 1.50 and the mass ratio of kenaf fiber was 25%.
(Characteristic evaluation)
The bending strength and bending elastic modulus of the plate-like fiber reinforced plastic obtained in Reference Examples 1 and 2, Examples 1 to 3 and Comparative Examples 1 and 2 were performed in accordance with a three-point bending test of JIS K7055. . The span of the three-point bending test was 80 mm. Izod impact test values were also measured.

  Here, as a test piece for measurement, in the bending test, the plate-like fiber reinforced plastic is formed into a shape having a width of 100 mm and a length of 15 mm, and in the impact test, the plate-like fiber reinforced plastic is formed into a shape having a width of 12 mm and a length of 65 mm. What was cut | disconnected was used, the repetition number of measurement was set to 5, and the average value was made into the measured value.

  The following formulas were used as specific formulas for calculating bending strength and flexural modulus.

Bending strength = 3PbL / 2bh ² (MPa)
here,
Pb: Breaking load (N)
L: Span (mm)
b: Width of test piece (mm)
h: Height of test piece (mm)
Flexural modulus = L ³ / 4bh ² × (P / δ) (MPa)
Here, P / δ: slope of the linear portion of the load-deflection curve L: span (mm)
b: Width of test piece (mm)
h: Height of test piece (mm)
Table 1 shows a summary of the above measurement results for Examples and Comparative Examples.

  Further, the following formula was used as a specific formula for calculating the Izod impact value.

Izod impact value = E / (b × h)
Here, E = W × R × (cos β−cos α) −L
W: Weight of hammer (N)
R: Distance to the center of gravity of the hammer (m)
α: Hammer lift angle β: Hammer swing angle after test L: Energy loss (when hammer is swung)
b: Width of test piece (mm)
h: Test piece thickness (mm)
Table 2 shows a summary of the above measurement results for Examples and Comparative Examples.

The fiber reinforced plastic using the lignocellulosic fiber that crushes and disappears the cell lumen of Reference Example 1 as the reinforcing material is the fiber reinforced plastic of Comparative Example 1 using the lignocellulose fiber having the cell lumen as the reinforcing material. It showed higher strength performance. That is, the strength performance of the obtained fiber reinforced plastic is improved by using the lignocellulose fiber from which the cell lumen has disappeared as the reinforcing fiber.

A fiber-reinforced plastic that crushes and disappears the cell lumen of Reference Example 2 and that uses part of the cellulose microfibrils constituting the cell wall as whisker-like fibers and lignocellulose fibers that protrude from the cell wall surface as a reinforcing material The strength performance is more improved than the fiber reinforced plastic prepared in Reference Example 1. In particular, the impact strength is significantly improved.

The mechanical strength of the fiber reinforced plastic using the lignocellulosic fiber bundle subjected to the treatment for relaxing the bond strength between single fibers before the beating treatment of Example 1 is a treatment for relaxing the bond strength between single fibers. The mechanical strength of the fiber reinforced plastic using the lignocellulosic fiber that was not subjected to the test was greatly exceeded. Moreover, the strength performance superior to the fiber reinforced plastic using the lignocellulose fiber bundle which was not beaten was shown. In other words, the mechanical strength of the resulting fiber-reinforced plastic is improved by using, as a reinforcing material, lignocellulosic fibers in the form of fiber bundles that have been treated to relax the bond strength between single fibers before the beating treatment. It will be done.

The mechanical strength of the fiber reinforced plastic using the lignocellulose fiber bundle subjected to the beating treatment after the treatment with ammonium oxalate and sodium hydroxide in order to relax the bonding between the single fibers in Example 3 was The mechanical strength of the fiber reinforced plastic using the lignocellulose fiber bundle, which was beaten after the treatment with sodium hydroxide and sodium sulfide under the high temperature and high pressure in Example 2 , was exceeded. That is, the strength performance of the fiber reinforced plastic is improved by using ammonium oxalate and sodium hydroxide as the treatment for relaxing the bonding between the single fibers.

It is a perspective view of the lignocellulose fiber which consists of a cell wall and a cell lumen. It is a front longitudinal cross-sectional view of the lignocellulose fiber showing the space | gap which generate | occur | produces inside the fiber derived from a cell lumen | bore which arises when a lignocellulose fiber and a plastics are compounded. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of an embodiment of the present invention, and is a side view of a fiber reinforced plastic using a single plant fiber sheet as a reinforcing material. It shows an example of embodiment of this invention and is a side view of the fiber reinforced plastic which uses three plant fiber sheets as a reinforcing material. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of a vegetable fiber mat impregnated with a resin, which is formed from a uniform mixed solution composed of a vegetable fiber and a resin solution by papermaking, showing an example of an embodiment of the present invention. The present invention relates to an embodiment of the present invention, in which lignocellulose produced as a result of heavy beating treatment of lignocellulose fiber, part of cellulose microfibrils jumped out of the cell wall of lignocellulose fiber as whisker-like fibers. It is a perspective view showing a fiber. The embodiment relates to an embodiment of the present invention, and before the beating treatment of the fiber bundle, when the treatment for reducing the binding force between the single fibers is not performed, the effect of the beating treatment is not sufficiently expressed. It is a perspective view about a fiber bundle. The lignocellulosic fiber relates to an embodiment of the present invention, and shows that the effect of the beating treatment is sufficiently expressed by reducing the binding force between the single fibers before the beating treatment of the fiber bundle. It is a perspective view about a bundle.

Explanation of symbols

1. Lignocellulose fiber with monofilament morphology 2. Cell wall 3. Cell lumen 4. Plastic 5. Void (defect in material)
6. Cellulose microfibrils protruding from the cell wall of lignocellulose fiber 7. Lignocellulose fiber having the form of fiber bundle 8. Lignocellulose fiber bundle with loose bonds between single fibers

Claims (3)

In a fiber reinforced plastic using a lignocellulose fiber composed of a cell wall and a cell lumen as a reinforcing material, the lignocellulose fiber has a form of a fiber bundle, and is composed of ammonium oxalate, sodium hydroxide, and chlorite. A fiber-reinforced plastic , which has been subjected to beating treatment until the bonding strength between single fibers is relaxed using either acid salt or hypochlorite, and the cell lumen disappears . 2. The fiber-reinforced plastic according to claim 1, wherein part of cellulose microfibrils constituting the cell wall by beating treatment protrudes from the cell wall surface as a whisker-like fiber. In the method for producing a fiber reinforced plastic using a lignocellulose fiber composed of a cell wall and a cell lumen as a reinforcing material, the lignocellulose fiber has a form of a fiber bundle, and is composed of ammonium oxalate and sodium hydroxide. Of fiber reinforced plastic, characterized in that the treatment of relaxing the bond strength between single fibers using any one of chlorite and hypochlorite, and beating treatment until the cell lumen disappears Production method.

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