JP2015013916A - Vegetable fiber reinforced thermoplastic resin material for molding, method for manufacturing the same, and molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vegetable fiber reinforced thermoplastic resin material and a molding thereof, higher in productivity, inexpensive and high in quality by preventing the resin material and the molding from having a color and an odor and reducing a tar-like component adhering to a die surface when a high rigid fiber reinforced plastic resin material and a molding are manufactured using a vegetable fiber.SOLUTION: The vegetable fiber reinforced thermoplastic resin material for molding containing a palm fruit extraction residue and/or a vegetable fiber derived from a palm empty fruit bunch and a thermoplastic resin as a raw material and having a moisture content of 0.3 or less wt.% can vastly reduce a tar adhesion component on the surface of a mold die by preventing thermal decomposition and substantially improve moldability.

Description

  The present invention relates to a plant fiber reinforced thermoplastic resin material and a method for producing the same.

  Plant fibers such as bagasse, kenaf, bamboo, and hemp have high tensile strength and rigidity, and are tougher and more rigid than general-purpose resins, so they are used as the fiber content of fiber-reinforced plastics. be able to. Glass fibers and carbon fibers are known as fibers of fiber reinforced plastics. Although carbon fiber has low specific gravity, it is expensive, and glass fiber is relatively inexpensive but has high specific gravity.

  As an example of a fiber reinforced plastic of plant fiber, Patent Document 1 discloses a method for producing a lightweight high-rigidity board by making a non-woven fabric with kenaf fiber and polypropylene fiber and hot pressing. However, in order to obtain this lightweight high-rigidity board, dedicated large-scale equipment such as a fiber opening device is required, and since the board is produced by press molding, the shape is limited, and the production of a three-dimensional shape board Requires two pressing steps. Furthermore, kenaf fibers are disadvantageous in terms of cost because they need to be planted and harvested on a dedicated farm only for fiber extraction purposes. Moreover, since only the high strength bast portion is used, waste is generated.

  Patent Document 2 discloses a bagasse-based durable board, but does not specify fiber treatment. In addition, since the molding temperature is as low as 80 to 150 ° C., thermal decomposition of plant fibers is not a problem.

  Patent Document 3 discloses a method for modifying natural fibers by treating with high-temperature steam at 110 ° C. or higher as a natural fiber treatment method. This method produces a composite material having a low coefficient of expansion due to moisture absorption and excellent strength. It is an object.

  Patent Document 4 invents a bagasse fiber processing method, which is a dry distillation process for carbonization of bagasse.

  Patent Document 5 discloses a method in which a bagasse fiber is brought into contact with an alum aqueous solution, and sugar and pitch components are separated and used as a reinforcing material for a plastic material. However, in this invention, since the resin is a thermosetting resin, polypropylene is used. No mention is made of adhesion of a spear component to a mold caused by thermal decomposition of plant fibers that occurs when kneading and molding at 180 ° C. or higher, such as injection molding by JIS.

Patent Document 6 discloses that a fiber reinforced plastic is manufactured by kneading a general-purpose resin such as polypropylene and bagasse, and a cheap and light bagasse fiber reinforced plastic is produced.
According to the disclosed information, in order to blend polypropylene that is coarsely water-soluble with plant fibers that are hydrophilic, the polypropylene grafted with maleic anhydride is kneaded with the plant fibers and polypropylene, so that Rigidity and strength have been developed, and the impact value has been improved.

  In this patent, when plant fibers are kneaded with polypropylene, the viscosity becomes high, so that the formability to a three-dimensional thin plate is lowered, and the lack of filling is partly pointed out as a problem. For this reason, the kneading temperature or the injection temperature needs to be 200 ° C. or more, but at 200 ° C. or more, the bagasse fiber is thermally decomposed and pyrolyzed and carbonized. In order to solve this problem, the polypropylene to be kneaded has been devised so as to be molded at a temperature of 200 ° C. or less as a high-fluidity polypropylene to improve the moldability.

However, the bagasse fiber reinforced polypropylene resin material and injection-molded product of this patent have the following problems.

a. At a temperature at which bagasse fibers are thermally decomposed, brownish brown deposits are formed on the surface of the molding die and do not dissolve in organic solvents such as ethanol and acetone.
b. High flow polypropylene for improving moldability has a low molecular weight, so the impact of the molded product is low.

  Plant fibers are composed mainly of hemicellulose, cellulose and lignin. On the other hand, in order to ensure the fluidity necessary for mixing and molding with the thermoplastic resin, heating is performed to near the limit temperature for thermal decomposition. For example, in Patent Document 7, at the melt-kneading temperature exceeding 170 ° C., the progress of coloring due to “burning” of plant cellulose fibers and the occurrence of a strange odor are recognized, and the coloration and the generation of a strange odor when formed into a molded product are inevitable. Things are described. In order to solve this, a letting process is performed, and the heatable temperature of kenaf is increased to 210 ° C. However, it has been reported that at 240 ° C, the plant fiber was scorched and had a strange odor.

  Patent Document 8 discloses a process for producing pellets for injection molding by mixing kenaf and polypropylene. However, it is reported that the temperature of the mixing wall of the mixing apparatus is set to 200 ° C. or lower. In the examples, after the pellets are manufactured, the pellets are oven-dried at 100 ° C. for 24 hours, and injection molded at 190 ° C. is disclosed.

  When using plant fiber composites, it is common to dry the plant fibers. For example, in Patent Document 9, banana fiber, palm palm fiber, and sisal hemp fiber are defibrated and dried in the sun. The molding temperature is 210 ° C.

  In Patent Document 10, a board using a non-woven fabric of kenaf fibers is produced, and the press heating temperature is set so that the internal temperature of the board is 200 ° C.

  Patent Document 11 discloses a flame retardant composite material board made of kenaf fiber, and the board fiber is made by reducing the moisture content to 30-40% by drying treatment at 60 ° C. for 30-120 minutes. In this case, the upper limit is a molding temperature of 200 ° C. in the examples.

As described above, in order to produce a composite material of plant fiber and plastic, drying is common and the inventors have also performed. However, even after drying, the plant fiber / polypropylene composite material undergoes thermal decomposition at around 200 ° C, as described above, so it is necessary to use a high flow, relatively low molecular weight polypropylene grade to ensure fluidity. In addition, molding at 200 ° C. or higher without thermal decomposition was difficult.

JP 2004-314538 A JP-A-6-287321 JP 2009-132094 Japanese Patent Laid-Open No. 2002-18416 JP 49-2907 Japanese Patent No. 4370416 JP-A-2005-259601 JP 2010-23356 JP 2010-202797 JP 2010-280187 A JP 2011-000709 A

  The problem to be solved by the present invention is to prevent the coloring and odor of the resin material and the molded product, and the mold surface when producing a highly rigid fiber reinforced thermoplastic resin material and the molded product using plant fibers. It is to provide a plant fiber reinforced thermoplastic resin material and a molded product thereof with higher productivity, lower cost and higher quality by reducing the amount of spear-like components adhering to the surface.

  When the present inventors conducted earnest research to solve the above-mentioned problems, the water content containing a palm fruit extract residue and / or a plant fiber derived from palm empty fruit bunch and a thermoplastic resin as a raw material is 0.3% by weight or less. It has been found that a certain plant fiber reinforced thermoplastic resin material for molding can greatly reduce the component of adhesion to the mold surface by preventing thermal decomposition, and can greatly improve the moldability. The invention has been completed.

That is, the present invention
(1) A plant fiber reinforced thermoplastic resin material for molding, containing a palm fruit extract residue and / or a plant fiber derived from palm empty fruit bunches, and a thermoplastic resin, wherein the water content is 0.3% by weight or less,
(2) The plant fiber reinforced thermoplastic resin material for molding according to (1), wherein the aspect ratio of the palm fruit extract residue and / or the plant fiber derived from palm empty fruit bunch is 20 or more,
(3) The molding plant according to (1) or (2), containing 5 to 50% by weight of a palm fruit extract residue and / or a plant fiber derived from palm empty fruit bunch and 50 to 95% by weight of a thermoplastic resin. Fiber reinforced thermoplastic resin,
(4) The plant fiber-reinforced thermoplastic resin material according to any one of (1) to (3), wherein the thermoplastic resin is a polyolefin-based resin,
(5) Palm fruit extract residue and / or plant fiber derived from palm empty fruit bunches are washed with water or an organic solvent, and the plant fiber and thermoplastic resin are kneaded at 180 ° C. to 270 ° C., and then the water content is 0.3% by weight. A method for producing a plant fiber-reinforced thermoplastic resin material for molding, characterized by drying to the following:
(6) The method for producing a plant fiber-reinforced thermoplastic resin material for molding according to (5), wherein the plant fiber is washed with 10 parts by weight or more of water or an organic solvent with respect to 1 part by weight of the plant fiber.
(7) A molded product obtained by molding the plant fiber-reinforced thermoplastic resin material according to any one of (1) to (4) at 160 ° C to 270 ° C,
It is.

  By using the plant fiber reinforced thermoplastic resin material for molding having a moisture content of 0.3% by weight or less containing the palm fruit extract residue and / or the plant fiber derived from the palm empty fruit bunch and the thermoplastic resin, thermoforming The possible temperature rises from 200 ° C. to 260 ° C., which is the upper limit of conventional plant fiber composite materials, and the moldability is greatly increased, and various thermoplastic resins can be used. Prevention of thermal decomposition not only raises the moldable temperature, but also prevents the thermal decomposition of the plant fiber, thereby greatly reducing the component of the resin adhering to the molding die surface. In addition, the off-flavor and unpleasant odor of the molded product due to the thermal decomposition of the plant fiber can be greatly reduced. By such an effect, the application range of a vegetable fiber / thermoplastic resin composite material is greatly expanded.

It is a figure which shows the preparation methods of the vegetable fiber and a polypropylene pellet by a uniaxial kneader. It is a graph which shows the relationship between the absorption rate (weight ratio) of the EFB fiber moisture after drying of palm empty fruit bunches (EFB) fibers and EFB / polypropylene pellets, and exposure time in the atmosphere. In the figure, Δshort fibers are EFB fibers (fiber length 0.93 mm), ◆ Long fibers are EFB fibers (fiber length 3.41 mm), and ● pellets are EFB / polypropylene pellets. It is a graph which shows the adhesion amount of the spear component to the metal mold | die surface after the hot press molding by palm empty fruit bunch (EFB) fiber and a polypropylene pellet. It is a graph which shows the adhesion amount of the spear component to the metal mold | die surface after the heat press molding by palm fruit extraction residue (MF) fiber and a polypropylene pellet.

(Plant fiber reinforced thermoplastic resin material for molding)
The plant fiber reinforced thermoplastic resin material for molding of the present invention contains a palm fruit extract residue and / or plant fiber derived from palm empty fruit bunch as a raw material and a thermoplastic resin. The kneaded product is also pelletized with a pelletizer or the like.
The plant fiber reinforced thermoplastic resin material of the present invention preferably has a weight ratio of palm fruit extract residue and / or plant fiber derived from palm empty fruit bunches of 5 to 50% by weight, more preferably 30 to 40% by weight. is there. When using a palm fruit extraction residue and palm empty fruit bunch together, the mixture ratio of both can be set arbitrarily. The weight ratio of the thermoplastic resin is preferably 50 to 95% by weight, more preferably 60 to 70% by weight.
If the amount of plant fiber is too large, the viscosity becomes too high, and the moldability may decrease. If the amount of plant fiber is too small, the ratio of the thermoplastic resin increases, so the material cost increases, and the effect of using the plant fiber may be reduced.
The moisture content of the plant fiber reinforced thermoplastic resin material is 0.3% by weight or less, preferably 0.25% by weight or less. If the amount of water is too large, the plant fibers blended at the time of molding may be thermally decomposed and the coloring may increase.
Examples of the thermoplastic resin that can be used in the present invention include polyolefin resins, polyester resins, polyamide resins, ABS resins, polycarbonate resins, and polyacetal resins, and one or more of these can be used in combination. . Among these, polyolefin resin is preferable and polypropylene is more preferable.
For the purpose of improving impact properties or bending strength, modified polypropylene grafted with maleic anhydride is added to the molding fiber reinforced thermoplastic resin material of the present invention in the range of 0.1 to 20% by weight. It is preferable.
In addition, other fiber reinforcements and fillers can be added to the plant fiber reinforced thermoplastic resin material of the present invention as long as it does not hinder molding.

(Palm empty fruit bunch, palm fruit extract residue)
Palm empty fruit bunches (hereinafter sometimes referred to as EFB (Empty Fruit Bunch)) and palm fruit extract residue (hereinafter sometimes referred to as MF (Mesocarp Fiber)) are used in the process of producing palm oil. It is discharged as a by-product.
Palm empty fruit bunches are remaining fruit bunches after the fruits contained in the harvested fruit bunches (Fresh Fruit Bunch) are removed, and are mainly composed of plant fibers. Moreover, a palm fruit extraction residue is a residue after extracting oil from a palm fruit, and has a vegetable fiber as a main component.

The average fiber length of the EFB fiber or MF fiber is preferably 2 mm to 10 mm, more preferably 3 mm to 5 mm. If the average fiber length is too short, the aspect ratio (the ratio of the length of the plant fiber to the diameter of the cross section of the plant fiber) is lowered, and the mechanical strength of the composite may be lowered. If the average fiber length is too long, the viscosity becomes high when the polymer is melted and molded, and the moldability may be significantly reduced. Accordingly, the aspect ratio is preferably 20 or more, more preferably 25 to 50. Thus, when the fiber diameter is small and the aspect ratio is large, it is easy to knead with the resin and the moldability can be improved.
In order to adjust to a desired average fiber length, EFB fibers and MF fibers can be pulverized as necessary.

Since the pellets are blackened due to organic matter contained as impurities in the plant fibers, it is preferable to wash the plant fibers in advance. As a solvent to be washed, water or an organic solvent can be used, whereby various organic substances contained in the plant fiber are removed. By removing the organic matter in the plant fiber, it is possible to greatly suppress the spear component adhering to the mold due to the thermal decomposition of the plant fiber, eliminating the need to frequently wash the mold and greatly improving molding productivity. Can be made.
As a washing method, washing with 10 parts by weight or more, more preferably 15 parts by weight or more of water or an organic solvent is performed with respect to 1 part by weight of plant fiber. Since there may be no difference in effect even if there is too much water or organic solvent to be washed, it is preferably 40 parts by weight or less, more preferably 20 parts by weight or less.
When water is used, the temperature is preferably 40 to 100 ° C, more preferably 60 to 80 ° C.

  The plant fiber is washed with water or an organic solvent and then dried by heating. Thereby, various organic substances adhering to or contained in the plant fiber are removed. Examples of the drying method include hot air drying, oven drying, and vacuum heat drying.

  The dried plant fiber is mixed with the thermoplastic resin without being exposed to moisture atmosphere. The mixing temperature is 180 ° C to 270 ° C. Preferably it is 200 degreeC-230 degreeC. The kneading method is not limited. For example, a uniaxial or biaxial kneader or an open kneader may be used. After kneading, pelletize with a pelletizer or the like.

The vegetable fiber reinforced thermoplastic resin can be formed into pellets and then molded with an injection molding machine or a press molding machine. However, since the pellet absorbs moisture immediately when exposed to the atmosphere, it is preferably dried by a method such as reduced pressure drying. The timing of drying is not limited, and may be performed before molding or simultaneously with molding. For example, the method of shape | molding after drying a pellet, the method of shape | molding, drying a pellet with the shaping | molding apparatus provided with the reduced pressure drying apparatus etc. are mentioned.
The molding temperature is preferably 160 ° C to 270 ° C, more preferably 180 ° C to 260 ° C, and even more preferably 180 ° C to 230 ° C.
The water content of the mixture of vegetable fiber and thermoplastic resin is 0.3% by weight or less, preferably 0.25% by weight or less. If the amount of water is too large, the plant fibers blended at the time of molding may be thermally decomposed and the coloring may increase.

The plant fiber reinforced thermoplastic resin material of the present invention thus prepared is particularly advantageous in the following points as compared with the case of using bagasse fiber.
○ MFR (melt flow rate; an indicator of resin fluidity)
When EFB fiber or MF fiber is used, MFR is increased and the fluidity of the resin is improved, so that the moldability of the resin is better than when bagasse fiber is used. By using EFB fiber or MF fiber, molding at a lower temperature can be realized, which is advantageous in that it can prevent thermal decomposition of plant fibers.
○ Smoothness of the surface of the molded body As an index of surface roughness, the Rz value (10-point average, unit μm) becomes smaller, and the surface of the molded body becomes smoother than when bagasse fibers are used. Quality is improved.
The fiber diameter of EFB fiber and MF fiber (about 0.1 mm) is thinner than bagasse fiber (about 0.3 mm), so the surface roughness can be reduced, so fiber reinforcement is possible even if the fiber length is shorter than conventional bagasse. The effect of can be demonstrated.

  Examples of the present invention will be described below. In addition,% in an example shall mean a weight reference | standard unless there is particular notice.

(Comparative Examples 1-2)
EFB fibers having a fiber length of 10 mm to 50 mm were pulverized to have a fiber length distribution of 1 mm to 5 mm. The average fiber length was 3.41 mm and the aspect ratio was 28.4. EFB fiber was washed with warm water (80 ° C) while heating and stirring with a heater, adding 800 ml of distilled water to a 1000 ml beaker for 40 g of EFB fiber to remove the remaining water-soluble components. . After washing, the EFB fiber was filtered and dried. The weight of impurities in EFB fiber after washing treatment decreased by 8%. Furthermore, the EFB fiber was heat-dried in an oven for 24 hours at 80 ° C.
Next, EFB fibers and polypropylene resin were mixed at a weight ratio of 40:60 in a single-screw kneader as shown in FIG. 1 and heated and extruded at 200 ° C. to produce pellets. The moisture content of the pellets at this time was 0.8%.
2 g of this pellet was weighed and subjected to hot press molding. The hot press conditions were as follows: pressure 100 kgf / cm2, holding time 10 minutes, temperature 200 ° C, 240 ° C, 260 ° C.
In order to check the heat decomposability of the molded body prepared under each condition, the color tone of the molded body was evaluated.
The color tone evaluation was confirmed visually by 10 panelists, and based on the criteria in Table 1, the color tone of the EFB fiber before heating was set to 5 points, and the average value was calculated by assigning 1 to 5 points according to the degree of coloring. . Those with an average value of 3.5 or more were judged as acceptable as the color tone.

(Table 1) Color tone evaluation criteria

(Table 2) Color tone evaluation results

  From the results in Table 2, the color evaluation of Comparative Examples 1 and 2 is less than 3.5 points, and if the pellet water content is 0.8%, the thermal decomposition will be reduced when the hot press molding temperature is increased from 200 ° C to 240 ° C or 260 ° C. Resulting.

(Examples 1-2, Comparative Examples 3-4)
As in Comparative Example 1, EFB fibers from which water-soluble components in the EFB fibers were removed were prepared, and the EFB fibers were dried to a moisture content of 1% or less at 100 ° C., 5 hours, 5 torr using a vacuum heating dryer. Immediately after drying, EFB fibers and polypropylene were mixed and extruded at a weight ratio of 40:60 to produce pellets. After the pellets were prepared, the pellets were dried at 100 ° C., 5 hours, 5 torr using a vacuum heat drying apparatus. After drying, the pellets were left indoors (25 ° C., humidity 55%) for 0 minutes, 20 minutes, 40 minutes, and 60 minutes, followed by hot press molding. The hot press conditions were a pressure of 100 kgf / cm ² , a holding time of 10 minutes, and a temperature of 260 ° C. In addition, the moisture values of the pellets after being left for 0 minutes, 20 minutes, 40 minutes, and 60 minutes were 0%, 0.25%, 0.35%, and 0.42%, respectively. The results of color tone evaluation are shown in Table 3.

(Table 3) Color tone evaluation results

From Table 3, the pellets after drying were allowed to stand in the room for 0 and 20 minutes and then molded, and the color tone evaluation was 3.5 points or more, which was good. For 0 minutes, the color tone evaluation was the same as that molded at 200 ° C., and when the panelists evaluated the presence or absence of unpleasant odors due to scoring, no unpleasant odors were found. Became.
However, if the indoor exposure time is longer than 40 minutes, the discoloration due to scoring progresses, and the color tone evaluation becomes 2.4 points in 40 minutes, 1.4 points in 60 minutes, and unpleasant odor due to scoring by 10 panelists. When the presence or absence was evaluated, the result showed that unpleasant odor was recognized in all cases. From the above results, it is recognized that the moisture adsorbed on the pellets lowers the thermal decomposition temperature of the plant fiber, and the molding temperature is reduced from 200 ° C to 260 ° C by removing the moisture of the pellets to at least 0.3% or less. It became clear that it was possible to rise.

(Test Example 1)
The weight change of 1 g of EFB fiber and 1 g of EFB fiber / polypropylene pellets (40% by weight of plant fiber) was measured when left in the room after drying under reduced pressure. The temperature change under reduced pressure was 100 ° C, 5hr, 5torr, and the weight was measured with an electronic balance placed in a room kept at 25 ° C and 55% humidity.
FIG. 2 is a graph showing the relationship between the indoor standing time and the change in weight of EFB fibers and EFB fibers / polypropylene pellets.
As can be seen from FIG. 2, the EFB fiber was 7% by weight after drying, the EFB fiber / polypropylene pellet was 0.75% by weight, and an increase in weight due to moisture absorption was observed. It was also found that both EFB fibers, EFB fibers and polypropylene pellets absorbed moisture immediately after exposure to the atmosphere. In particular, the moisture absorption after 20 minutes to 60 minutes was large.
Judging from FIG. 2, it was found that the EFB fiber / polypropylene pellets start to thermally decompose when moisture of 0.3 wt% or more is absorbed. This corresponds to adsorption of 0.75% by weight of water in the EFB fiber alone because the weight of the EFB fiber in the pellet is 40%. Since 0.75% by weight of moisture is absorbed within 5 minutes in EFB fibers after drying, it is necessary to strictly control the amount of moisture adsorbed in order to avoid thermal decomposition of EFB fibers and polypropylene when molding at 200 ° C or higher. It is judged that there is.

(Examples 3-6, Comparative Examples 5-8)
The relationship between the washing treatment of the plant fiber and the mold adhesion component (soil component) was investigated.
After EFB fiber or MF fiber was not washed or washed, it was dried in an oven at 60 ° C. for 2 hours, and then allowed to stand at room temperature for 1 day. The water content of the EFB fiber or MF fiber after standing was 7%. The average fiber length was 3.41 mm and the aspect ratio was 28.4.
The washing conditions for plant fibers were 80 ° C. when washing with water, and the weight ratio of plant fibers to water was 1:20. When washing with acetone, it was performed at 25 ° C., and the weight ratio of plant fiber to acetone was 1:20.
Next, according to the method of Example 1, washed or unwashed EFB fiber or MF fiber and polypropylene were kneaded to produce 40% plant fiber / polypropylene pellets. When the pellets were dried, they were dried at 100 ° C., 5 hours, 5 torr with a vacuum heat drying apparatus. Hot press molding was performed on the produced pellets. The hot press conditions were a pressure of 100 kgf / cm ² , a holding time of 10 minutes, and a temperature of 260 ° C.
In addition, the washing | cleaning method of each plant fiber, the presence or absence of the drying process, and the moisture value of the pellet were shown in Table 4.
At the time of molding, an aluminum foil sheet was placed between the mold and the pellet. After molding, the aluminum foil sheet was peeled off from the molded body, and its weight was measured. When the spear component adheres, the weight of the aluminum foil sheet increases. Therefore, the weight difference between the aluminum foil sheets before and after molding was measured and used as a mass component (mass change). When the value of Mass change is 1.5 × 10 ⁻⁴ or less, the amount of adhesion of the spear component is not visually recognized, and it is judged that the amount of spear component adhesion is small and good.
The results of EFB fibers (Examples 3 to 4, Comparative Examples 5 to 6) are shown in FIG. 3, and the results of MF fibers (Examples 5 to 6 and Comparative Examples 7 to 8) are shown in FIG.

(Table 4) List of plant fiber treatment

Under both molding conditions of 200 ° C and 260 ° C, the mass change value of both EFB fiber and MF fiber was 1.5 × 10 ^-4 or less, and the spear component was greatly reduced. As a result, in both MF fiber and EFB fiber, it was found that the washing treatment of plant fiber with hot water or acetone and the vacuum drying treatment of the pellet greatly affect the decrease in the component of the spider.

(Example 7, Comparative Example 9) Comparison of MFR of polypropylene resin blended with MF fiber and bagasse fiber MF fiber of the present invention: resin material blended with polypropylene at 40:60 and bagasse fiber: blended with polypropylene at 40:60 The MFR (melt flow rate) of the obtained resin material was measured. MFR represents the fluidity of the resin. According to the method specified in JISK7210: 1999, the temperature determined by the resin in the cylinder, for example, 190 ° C for general polyethylene and 2160gf / cm for resin heated to 230 ° C for polypropylene. ^When a load of ² is applied, the flow rate (g / 10min) flowing out from the determined pore (orifice) in 10 minutes is expressed.
The higher the MFR value, the better the fluidity and the better the moldability of the resin.
The results of measuring MFR are shown in Table 5.

(Table 5) MFR measurement results

  As shown in the results of Table 5, those blended with MF fibers had higher MFR values than those blended with bagasse fibers, indicating that the resin moldability was superior to bagasse fibers.

(Examples 8 to 9, Comparative Example 10)
The surface roughness (Rz value) of the molded body prepared in the same manner as in Example 1 was measured using EFB fibers, MF fibers and bagasse fibers having different fiber lengths as raw materials.
The surface roughness Rz value (10-point average, unit μm) was measured in a measuring section of 7.2 mm using a small surface roughness measuring instrument SJ-301 (manufactured by Mitutoyo Corporation) as a measuring instrument. The results are shown in Table 6.

(Table 6) Comparison of surface roughness (Rz value)
* Average fiber length 3mm

  As shown in Table 6, it was shown that those blended with EFB fiber or MF fiber had a lower Rz value than bagasse fiber, a smoother surface, and good quality of the molded product.

  Due to the effect of preventing thermal decomposition of the plant fiber / thermoplastic resin composite material according to the present invention, the molding processable temperature is significantly increased from the conventional 200 ° C. to 260 ° C., and the molding processability is increased. Can be used. Not only the molding processable temperature rises but also the amount of the spear component adhering to the mold surface due to the thermal decomposition of the plant fiber is greatly reduced, so that the maintenance of the mold becomes extremely easy. Moreover, the bad smell and unpleasant odor of a molded object are suppressed by the thermal decomposition of a vegetable fiber being suppressed. Due to the above effects, a high-quality plant fiber reinforced plastic using inexpensive plant fibers can be provided.

Claims (7)

A plant fiber reinforced thermoplastic resin material for molding containing a palm fruit extract residue and / or a plant fiber derived from palm empty fruit bunches and a thermoplastic resin and having a moisture content of 0.3% by weight or less. The plant fiber reinforced thermoplastic resin material for molding according to claim 1, wherein the aspect ratio of the palm fruit extract residue and / or the palm fiber derived plant fiber is 20 or more. The plant fiber reinforced thermoplastic resin for molding according to claim 1 or 2, comprising 5 to 50% by weight of a palm fruit extract residue and / or a plant fiber derived from palm empty fruit bunch and 50 to 95% by weight of a thermoplastic resin. Wood. The plant fiber-reinforced thermoplastic resin material for molding according to any one of claims 1 to 3, wherein the thermoplastic resin is a polyolefin-based resin. Palm fruit extraction residue and / or plant fiber derived from palm empty fruit bunches are washed with water or an organic solvent, the plant fiber and thermoplastic resin are kneaded at 180 ° C. to 270 ° C. and then dried to a moisture content of 0.3% by weight or less. A process for producing a plant fiber-reinforced thermoplastic resin material for molding. The manufacturing method of the vegetable fiber reinforced thermoplastic resin material for shaping | molding of Claim 5 which wash | cleans with 10 weight part or more of water or an organic solvent with respect to 1 weight part of vegetable fibers. A molded article obtained by molding the plant fiber-reinforced thermoplastic resin material according to any one of claims 1 to 4 at 160 ° C to 270 ° C.