JP6155915B2 - Manufacturing method of fiber molded body - Google Patents

Description

  The present invention relates to a method for producing a fiber molded body. More specifically, the present invention relates to a method for manufacturing a fiber molded body having a structure in which a plurality of plant fibers are bound by a thermoplastic resin.

  In recent years, development of composite materials using both natural and synthetic materials has been underway. For example, a fiber molded body using a fiber mat in which vegetable fibers and thermoplastic resin fibers are mixed is known. In this fiber molded body, plant fibers are bound with a thermoplastic resin by heating a fiber mat and melting thermoplastic resin fibers. Such a composite material is useful from the viewpoint of environmental measures, but may require various measures that are not required when using only synthetic materials. For example, Patent Document 1 below discloses countermeasures for deodorizing wood materials.

JP 2000-289005 A

Patent Document 1 describes that odor is generated when a wood material is heat-treated. And as a countermeasure, a method of deodorizing by applying a sodium hydrogen carbonate aqueous solution to the woody material after heat treatment or immersing in a sodium hydrogen carbonate aqueous solution is disclosed.
However, the method disclosed in Patent Document 1 is a measure against odor generated by heat treatment of a wooden material, and cannot be similarly used for odors having different generation factors.
The present invention has been made in view of the above circumstances, and in the production of a fiber molded body in which plant fibers are bound with a thermoplastic resin, the production of a fiber molded body capable of taking measures against deodorization in the production process. It aims to provide a method.

In order to solve the above-mentioned problem, the method for producing a fiber molded body according to claim 1 contacts a plurality of plant fibers (excluding plant fibers in which a self-adhesive component is generated) defibrated by letting with an alkaline aqueous solution. A contact process;
A drying step of drying the plurality of plant fibers that have undergone the contact step;
A plurality of plant fibers that have undergone the drying step, and a binding step of binding using an olefin-based thermoplastic resin having a melting point of less than 170 ° C. ,
The alkaline aqueous solution contains sodium hypochlorite,
The concentration of sodium hypochlorite in the alkaline aqueous solution is 1 ppm or more and 50 ppm or less on a mass basis,
In the binding step, in a state where the plurality of plant fibers that have undergone the drying step and the olefinic thermoplastic resin coexist, the whole is heated to a temperature of 200 ° C. or less, and the olefinic thermoplastic resin is heated. The gist is to include a melting process .
The method for producing a fiber molded body according to claim 2 includes a washing step of washing the alkaline aqueous solution with water from a plurality of plant fibers having undergone the contact step in the method for producing a fiber molded body according to claim 1. The gist is not .
The method for producing a fiber molded body according to claim 3 is the method for producing a fiber molded body according to claim 1 or 2 ,
In the contact step,
Container and said container
A rotating device provided rotatably inside, a contact device comprising:
The container is formed in a substantially cylindrical shape inside, and is divided into upper and lower halves on the container upper part and the container lower part,
The upper part of the container is provided with an inlet for introducing the plant fiber into the container on one end side in the longitudinal direction, and the vegetable fiber is placed in the container on the ceiling of the inner peripheral surface of the upper part of the container. Provided with a plurality of crescent-shaped guide plates for screwing,
The container lower part is provided with a discharge port for discharging the plant fiber on the other end side in the longitudinal direction, and the alkaline aqueous solution in contact with the plant fiber is discharged on the inner peripheral surface of the container lower part. A plurality of drain holes for discharging out of the container,
The rotating body is supported by a bearing of the container along the longitudinal direction of the container, and includes a rotating shaft led out of the container and a blade standing on the rotating shaft. , Is connected to a driving source through the rotating shaft and is rotatable.
The blade has a rectangular shape and uses a contact device whose long side is erected along the rotation axis.
When the plant fiber is introduced, the plant fiber is agitated while being rotated in the container by the movement of the blade rotated with the rotation of the rotating body and the guide plate, and is discharged from the input port. The gist is that it is a step of contacting the alkaline aqueous solution supplied into the container while being screwed toward the outlet .

The manufacturing method of the fiber molded object of Claim 1 is equipped with the contact process which makes a some plant fiber contact alkaline aqueous solution. Then, the drying process of drying the some plant fiber which passed through the contact process is provided. Furthermore, it comprises a binding step of binding a plurality of plant fibers that have undergone this drying step using an olefinic thermoplastic resin having a melting point of less than 170 ° C.
By manufacturing in this way, a deodorizing measure can be applied to the plant fiber that is the raw material of the fiber molded body. Furthermore, deodorizing measures can be taken in the process of manufacturing the fiber molded body. Thereby, the odor at the time of use can be suppressed effectively.

When the alkaline aqueous solution contains sodium hypochlorite and the concentration thereof is 1 to 10 ppm by mass, particularly effective deodorizing measures can be taken. Moreover, the odor at the time of use can be suppressed more effectively by it.
When the alkaline aqueous solution contains sodium bicarbonate and the concentration thereof is 500 to 100,000 ppm by mass, particularly effective deodorizing measures can be taken. Moreover, the odor at the time of use can be suppressed more effectively by it.

The present invention will be further described in the following detailed description with reference to the drawings referred to, with reference to non-limiting examples of exemplary embodiments according to the present invention. Similar parts are shown throughout the several figures.
It is a disassembled perspective view explaining the outline | summary of the contact apparatus which can be used by this method. It is explanatory drawing explaining the contact apparatus which can be used by this method.

  The items shown here are for illustrative purposes and exemplary embodiments of the present invention, and are the most effective and easy-to-understand explanations of the principles and conceptual features of the present invention. It is stated for the purpose of providing what seems to be. In this respect, it is not intended to illustrate the structural details of the present invention beyond what is necessary for a fundamental understanding of the present invention. It will be clear to those skilled in the art how it is actually implemented.

The present invention will be described in detail below.
The method for producing a fiber molded body of the present invention includes a contact step, a drying step, and a binding step. And by this method, the fiber molded object with which several plant fibers were bound by the olefin type thermoplastic resin is obtained.

The “contacting step” is a step of bringing a plurality of plant fibers into contact with an alkaline aqueous solution.
The plant fiber used in the present invention is a fiber derived from a plant, and includes a fiber taken out from a plant body and a fiber obtained by processing the fiber. Plants that are the source of plant fiber include kenaf, hemp, jute hemp, ramie, flax (flux), manila hemp, sisal hemp, crust, sansou, cocoon, banana, pineapple, coconut, corn, sugar cane, bagasse, palm, Various plants such as papyrus, straw, esparto, survivorgrass, wheat, rice, bamboo, various conifers (such as cedar and cypress), broad-leaved trees, and cotton are included. These may use only 1 type and may use 2 or more types together. Among these, bast plants, that is, kenaf, hemp, jute hemp, ramie, flax (flux) are preferable. Bast plants are generally fast growing and have excellent carbon dioxide absorption. For this reason, it can contribute to the reduction of the amount of carbon dioxide in the atmosphere and the effective use of forest resources. Furthermore, among the bast plants, kenaf is preferable, and kenaf fibers collected from kenaf bast are most preferable.

As the plant fiber, any processed plant fiber may be used. Especially, this method is suitable for the plant fiber processed using microorganisms and an enzyme. That is, it is suitable for plant fibers obtained through letting for extracting plant fibers from a plant body, or processing for washing plant fibers extracted from a plant body using microorganisms or enzymes. Of these, letting is a process of decomposing a substance such as pectin that adheres between plant fibers in a plant using microorganisms or enzymes. As described above, when processing using microorganisms or enzymes is performed, degradation products decomposed by the microorganisms or enzymes in the process adhere to the plant fibers, and the degradation products often cause odor. Therefore, this method can obtain a particularly high effect when using the plant fiber obtained by the above processing. The present invention uses plant fibers defibrated by letting.

The aqueous alkaline solution used in the present method is an aqueous solution containing a component that is alkaline and exhibits alkalinity. When the plant fiber is brought into contact with an alkaline aqueous solution, a compound that causes the earthy odor attached to the plant fiber (hereinafter simply referred to as “earthy odor”) can be removed. The compound considered to cause this earthy odor is a compound having an anisole skeleton such as trichloroanisole or a compound having a pyrazine skeleton such as isopropylmethoxypyrazine. It is believed that these compounds can be dissolved or extracted in an aqueous alkaline solution.
Further, when the plant fiber is brought into contact with an alkaline aqueous solution, the compound causing the rot odor attached to the plant fiber can be removed. Compounds considered to be a cause of rot odor are fatty acids such as decanoic acid and dodecanoic acid. These fatty acids are relatively high molecular weight compounds having a boiling point of 250 ° C. or higher. For this reason, it is difficult to remove fatty acids only by bringing plant fibers into contact with water. On the other hand, when the plant fiber is contacted with an alkaline aqueous solution, the fatty acid is neutralized and can be dissolved or extracted into the aqueous solution, and can be more easily removed from the plant fiber.

The alkali component contained in the alkaline aqueous solution used in the present method is not particularly limited as long as it is a component that can exhibit alkalinity by water. Specific examples include hydrogen carbonates such as sodium hydrogen carbonate and hypochlorites such as sodium hypochlorite. These may use only 1 type and may use 2 or more types together. Among these, sodium hypochlorite or sodium hydrogen carbonate is preferable from the viewpoints of versatility, safety, cost, and the like. The aqueous alkaline solution used in the present invention contains sodium hypochlorite.

When sodium hypochlorite is used as the alkali component, the concentration of sodium hypochlorite in the aqueous alkali solution is preferably 1 ppm or more on a mass basis. If this concentration is 1 ppm or more, a sufficient effect can be obtained for removal of earthy odor and rot odor. Moreover, although the upper limit of the sodium hypochlorite density | concentration in alkaline aqueous solution is not specifically limited, Usually, it is 50 ppm or less. The concentration of sodium hypochlorite in the alkaline aqueous solution used in the present invention is 1 ppm or more and 50 ppm or less on a mass basis. The sodium hypochlorite concentration is particularly preferably 1 to 10 ppm. In this range, it can suppress that an alkali component remains in a vegetable fiber, exhibiting the high effect with respect to earthy odor and rotten odor removal. This concentration is more preferably 2 to 8 ppm and particularly preferably 3 to 7 ppm.

  On the other hand, when sodium hydrogen carbonate is used as the alkali component, the concentration of sodium hydrogen carbonate in the aqueous alkali solution is preferably 500 ppm or more on a mass basis. If this density | concentration is 500 ppm or more on a mass basis, sufficient effect can be acquired with respect to removal of earthy odor and rotten odor. Moreover, although the upper limit of the sodium hydrogencarbonate density | concentration in aqueous alkali solution is not specifically limited, Usually, it is 500,000 ppm or less on a mass basis. This sodium hydrogen carbonate concentration is particularly preferably 500 to 100,000 ppm on a mass basis. In this range, it can suppress that an alkali component remains in a vegetable fiber, exhibiting the high effect with respect to earthy odor and rotten odor removal. This concentration is more preferably 1,000 to 80,000 ppm on a mass basis, and particularly preferably 5,000 to 50,000 ppm on a mass basis.

The method for bringing plant fibers into contact with an alkaline aqueous solution is not particularly limited. For example, an alkaline aqueous solution may be sprayed on the plant fiber, the plant fiber may be immersed in the alkaline aqueous solution, or other methods may be used.
Among these, when spraying alkaline aqueous solution on a vegetable fiber, the following contact apparatus (1) (refer FIG.1 and FIG.2) can be used, for example. If this contact apparatus (1) is used, a vegetable fiber and alkaline aqueous solution can be efficiently contacted, stirring a vegetable fiber in a container (3) under dispersion | distribution of alkaline aqueous solution.

The contact device (1) includes a container (3) and a rotating body (5) rotatably provided in the container (3).
Among these, the container (3) is comprised in the container upper part (3A) and the container lower part (3B) in the upper and lower halves. Moreover, the inside is formed in a substantially cylindrical shape.
Moreover, the container upper part (3A) is equipped with the insertion port (7) for throwing a vegetable fiber into a container (3) in the one end side of a longitudinal direction. Furthermore, the container upper part (3A) includes a plurality of crescent-shaped guide plates (9) on the ceiling portion of the inner peripheral surface. The guide plate (9) serves as a guide for screwing the plant fiber into the container (3).
On the other hand, the container lower part (3B) is equipped with the discharge port (11) for discharging | emitting a vegetable fiber in the other end side of a longitudinal direction. The container lower part (3B) includes a plurality of drain holes (13) on the inner peripheral surface. The drainage hole (13) is a hole for discharging the drainage solution of the alkaline aqueous solution in contact with the plant fiber to the outside of the container (3).

  Furthermore, the rotating body (5) includes a rotating shaft (15) and a blade (17) standing on the rotating shaft (15). The blade (17) has a rectangular shape, and its long side is erected along the rotation axis (15). The rotating body (5) is pivotally supported by the bearing (19) of the container (3) so that the rotating shaft (15) is along the longitudinal direction of the container (3). Further, the rotating body (5) is connected to a drive source (not shown) through a rotating shaft (15) led out of the container (3), and is rotatable in the direction (X).

  And when plant fiber is thrown in from a slot (7), plant fiber is made into a container (3) by the motion of the braid | blade (17) rotated with rotation of a rotary body (5), and a guide plate (9). It is stirred while being rotated inside. Then, it is screwed as shown by an arrow Y from the inlet (7) toward the outlet (11) (see FIG. 2). Meanwhile, the plant fiber is contacted with the alkaline aqueous solution.

The aqueous alkaline solution may be supplied into the contact device (1) in any manner. For example, a water supply pipe (not shown) can be provided on the ceiling of the upper part (3A) of the container, and the alkaline aqueous solution can be supplied into the container (3) through this water supply pipe. In this form, the alkaline aqueous solution can be sprayed from the ceiling of the upper part of the container (3A) toward the rotating shaft (15).
Moreover, a water supply path (not shown) is provided in the rotating shaft (15) of the rotating body (5), and the alkaline aqueous solution can be supplied from the connecting portion between the rotating shaft (15) and the blade (17). In this embodiment, the alkaline aqueous solution can be uniformly distributed from the rotating shaft (15) toward the entire inner peripheral surface of the container (3) as the rotating body (5) rotates.

  Thus, the alkaline aqueous solution contacted with the plant fiber is discharged from the drain hole (13) in the lower part of the container (3B) together with the component that is an odor source eluted from the plant fiber. On the other hand, the plant fiber is discharged from the discharge port (11) after being contacted with the alkaline aqueous solution.

  In addition, after making a vegetable fiber and aqueous alkali solution contact using the said contact apparatus (1), a plant fiber can be wash | cleaned using a contact apparatus (1) as needed. In this case, the plant fibers that have been in contact with the alkaline aqueous solution can be washed by spraying water instead of the alkaline aqueous solution.

  On the other hand, when plant fibers are immersed in an alkaline aqueous solution and the plant fibers and the alkaline aqueous solution are brought into contact with each other, the following method can be used. That is, an immersion tank storing an alkaline aqueous solution is prepared, and the plant fiber is immersed in the immersion tank so that the plant fiber and the alkaline aqueous solution can be brought into contact with each other. When the plant fiber and the alkaline aqueous solution are brought into contact with each other by dipping, a step of washing the alkaline aqueous solution with water (washing step) can be provided before the drying step thereafter. In particular, when an aqueous sodium hydrogen carbonate solution is used as the alkaline aqueous solution, it is preferable to provide a cleaning step.

  By providing the washing step, a higher deodorizing effect can be obtained. When a sodium hydrogen carbonate aqueous solution is used, the reason why a high deodorizing effect can be obtained by providing a cleaning step is not clear. However, it is thought that it is possible to prevent sodium bicarbonate remaining in the plant fiber and its reaction product from becoming a new source of odor. This method includes a binding step after the contacting step and the drying step. In this binding step, it is necessary to heat the plant fiber together with the thermoplastic resin to a temperature exceeding its melting point. And during this heating, it is conceivable that sodium hydrogen carbonate and its reactants remaining in the contacting step are decomposed and become a new odor source in the fiber molded body. On the other hand, when the cleaning process is provided, the odor at the time of use can be suppressed even for the fiber molded body obtained through the binding process.

  The “drying step” is a step of drying a plurality of plant fibers that have undergone the contact step. In this step, the plant fiber may be dried. The degree of drying is not particularly limited, and is preferably set to an appropriate moisture content depending on the plant fiber to be used. For example, the moisture content is preferably 2 to 20%. Moreover, although drying conditions etc. are not specifically limited, It is preferable to dry under the temperature of 180 degrees C or less, 25-150 degreeC is more preferable, 50-100 degreeC is more preferable. If a drying temperature is 180 degrees C or less, the thermal decomposition of the component which comprises a vegetable fiber can be prevented. For this reason, it can avoid generating a new odor source.

More the "binding step", a plurality of plant fibers with a drying step, melting point Ri step der of forming wear with less than 170 ° C. olefin thermoplastic resin in the present invention, in which a drying step in a state in which the plant fiber and an olefin-based thermoplastic resin is coexistence in its entirety, by heating to a temperature 200 ° C. or less, Ru steps der comprising the step of melting the olefinic thermoplastic resin. In this step, while using the plant fiber that has undergone the contact step and the drying step, and binding using an olefin-based thermoplastic resin having a melting point of less than 170 ° C., odor from the resulting fiber molded body can be suppressed. In particular, generation of tobacco odor can be effectively suppressed by using an olefin-based thermoplastic resin having a melting point of less than 170 ° C. as the binder resin. Compounds considered to cause tobacco odor are eugenol and isoeugenol produced by thermal decomposition of lignin. The generation of these compounds could be suppressed by suppressing the melting point of the binder resin to less than 170 ° C.

  In the binding step, it is necessary to heat the plant fiber together with the thermoplastic resin to a temperature exceeding the melting point of the thermoplastic resin. This is because the thermoplastic resin is heated and melted so that the molten binder resin is infiltrated between the plant fibers and then solidified, whereby the plant fibers can be bound to each other. However, when the heating temperature exceeds 200 ° C., it is observed that the thermal decomposition of the components in the plant fiber further proceeds compared to the heating at a temperature below that. And it is thought that the pyrolyzed decomposition product remains in the fiber molded body and is released as an odor during use. On the other hand, when the melting point of the thermoplastic resin used in the binding step is less than 170 ° C., it is not necessary to heat the plant fiber to a temperature exceeding 200 ° C. in the binding step. Therefore, it is considered that the thermal decomposition of the plant fiber can be effectively suppressed and the odor can be greatly suppressed.

The olefinic thermoplastic resin used in this method may have a melting point of 170 ° C. or lower, and the other conditions are not particularly limited. The olefinic thermoplastic resin is a resin in which 50% or more of all the structural units are derived from olefins. Examples of the olefin monomer constituting the olefin-based thermoplastic resin include ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, and 4-methyl-1-pentene. , 1-hexene, 1-octene and the like. These may use only 1 type and may use 2 or more types together.
That is, examples of the olefinic thermoplastic resin include polyethylene resins such as an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and an ethylene / 4-methyl-1-pentene copolymer. Is mentioned. These polyethylene resins are resins whose units are derived from ethylene by 50% or more of the total number of structural units. Furthermore, polypropylene resins such as propylene homopolymer, propylene / ethylene copolymer (propylene / ethylene random copolymer, etc.), propylene / 1-butene copolymer and the like can be mentioned. These polypropylene resins are resins whose units are derived from propylene by 50% or more of the total number of structural units.

The melting point of the olefinic thermoplastic resin used in this method is less than 170 ° C, preferably 120 to 165 ° C, more preferably 130 to 160 ° C, and still more preferably 140 to 155 ° C. This melting point (melting temperature) is measured according to JIS K7121.
The melt flow rate (MFR) is not particularly limited, but is preferably 15 g / 10 min or more. The MFR is more preferably 15 to 40 g / 10 min, further preferably 17 to 35 g / 10 min, and particularly preferably 20 to 32 g / 10 min. This MFR is measured according to JIS K7210.

  As described above, for example, Wintech WMX03, Wintech WSX02, Wintech WMG03, Wintech WMG03UX, or the like manufactured by Nippon Polypro Co., Ltd. can be used as the olefinic thermoplastic resin having a melting point of less than 170 ° C. Among these, Wintech WMX03 and Wintech WMG03 are preferable.

  Moreover, although the length of the vegetable fiber in the above-mentioned contact process is not specifically limited, It is preferable that the length of the vegetable fiber at the time of using at a binding process is 10-150 mm in average fiber length. The average fiber length is more preferably 20 to 100 mm, still more preferably 30 to 80 mm. The average fiber length is JIS L1015 in accordance with JIS L1015. Single fibers are randomly taken out by the direct method one by one, stretched straight without stretching, and the fiber length is measured on a measuring scale. It is the average value of the values measured for.

Furthermore, the olefin-based thermoplastic resin may include a modified olefin-based thermoplastic resin modified with a polar group as a part thereof. That is, the olefinic thermoplastic resin is a mixed olefin of a non-modified olefinic thermoplastic resin (hereinafter also simply referred to as “non-modified resin”) and a modified olefinic thermoplastic resin (hereinafter also simply referred to as “modified resin”). A thermoplastic resin (hereinafter also simply referred to as “mixed resin”).
The modified resin can exhibit high affinity for plant fibers due to the polar group of the modified resin. For this reason, when the olefinic thermoplastic resin is a mixed resin containing a modified resin, the plant fibers can be bound more firmly than when the modified resin is not contained.

The type of the polar group that the modified olefin-based thermoplastic resin has is not particularly limited, and examples thereof include a carboxylic anhydride group (—CO—O—OC—), a carboxylic acid group (—COOH), a carbonyl group (—CO—), hydroxyl (-OH), an amino group _(-NH 2), nitro group _(-NO 2), a nitrile group (-CN) and the like. These may use only 1 type and may use 2 or more types together. Among these, at least one of a carboxylic anhydride group, a carboxylic acid group, and a carbonyl group is preferable, and a carboxylic anhydride group or a carboxylic acid group is particularly preferable.

  These polar groups may be introduced using any compound. For example, maleic anhydride, itaconic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic acid, itaconic acid, fumaric acid, It can introduce | transduce using acrylic acid, methacrylic acid, etc. These may use only 1 type and may use 2 or more types together. Of these, maleic anhydride and itaconic anhydride are preferred, and maleic anhydride is particularly preferred.

  That is, the modified resin is preferably an acid-modified olefin thermoplastic resin into which at least one of a carboxylic anhydride group, a carboxylic acid group, and a carbonyl group is introduced. Furthermore, among them, an acid-modified olefin thermoplastic resin into which a carboxylic anhydride group or a carboxylic acid group has been introduced is more preferable.

  When the modified resin is acid-modified, the acid value of the modified resin is preferably 15 or more (usually 80 or less). In this range, it is possible to exhibit high binding properties to plant fibers while suppressing the ratio of the modified resin in the mixed resin. The acid value is more preferably 15 to 70, still more preferably 20 to 60, and particularly preferably 23 to 30. The acid value is measured according to JIS K0070.

  Furthermore, the molecular weight of the modified resin is preferably 10,000 to 200,000 in terms of weight average molecular weight. In this range, it is possible to exhibit high binding properties to plant fibers while suppressing the ratio of the modified resin in the mixed resin. The weight average molecular weight is more preferably 15,000 to 150,000, further preferably 25,000 to 100,000, and particularly preferably 35,000 to 60,000. The weight average molecular weight is measured by GPC method.

  In addition, when the olefinic thermoplastic resin is a mixed resin containing a modified resin, the modified resin is preferably 1 to 12% by mass when the total of the non-modified resin and the modified resin is 100% by mass. In this range, it is possible to exhibit high binding properties to plant fibers while suppressing the ratio of the modified resin in the mixed resin. This ratio is more preferably 2 to 9% by mass, further preferably 3 to 7% by mass, and particularly preferably 4 to 6% by mass.

  Further, in this method, the plant fibers may be bound together using an olefinic thermoplastic resin. Usually, the plant fiber and the olefinic thermoplastic resin are coexisted, and the whole is heated to melt the olefinic thermoplastic resin. Furthermore, pressurization is performed so that the molten olefin-based thermoplastic resin enters the gap between the plurality of plant fibers. Then, by cooling and solidifying the olefinic thermoplastic resin that has entered the gaps between the plurality of plant fibers, the plant fibers can be bound together by the olefinic thermoplastic resin.

  The shape, size, thickness and the like of the fiber molded body obtained by this method are not particularly limited. Further, its use is not particularly limited. This fiber molded body is used, for example, as an interior material and an exterior material for automobiles, railway vehicles, ships, airplanes, and the like. Among these, examples of the automobile article include an automobile interior material, an automobile instrument panel, and an automobile exterior material. Specifically, door base material, package tray, pillar garnish, side garnish, switch base, quarter panel, armrest, automotive door trim, seat structure material, seat backboard, ceiling material, console box, automotive dashboard, various types Instrument panel, deck trim, bumper, spoiler and cowling. Furthermore, for example, interior materials and exterior materials such as buildings and furniture can be mentioned. That is, door covering materials, door structural materials, and covering materials for various furniture (desks, chairs, shelves, bags, etc.) can be mentioned. In addition, a package, a container (such as a tray), a protective member, a partition member, and the like can be given.

Hereinafter, the present invention will be described specifically by way of examples.
[1] Production of fiber molded body <1> Example 1
(1) Preparation of plant fiber (contact process and drying process)
As the plant fiber, a kenaf fiber defibrated from the plant body kenaf by letting was prepared. This kenaf fiber was charged into the container 3 from the charging port 7 of the contact device 1 shown in FIGS. Then, a sodium hypochlorite aqueous solution having a concentration of 5 ppm was sprayed from a spray pipe (not shown) disposed on the ceiling in the container 3 while rotating the rotating body 5. The kenaf fiber was stirred while being rotated in the container 3 by a blade 17 erected on the rotating shaft 15, and in contact with the aqueous solution of sodium hypochlorite for 1 minute. Then, the kenaf fiber is screwed as shown by an arrow Y (see FIG. 2) from the inlet 7 to the outlet 11 while being in contact with the sodium hypochlorite aqueous solution, and from the outlet 11 to the outside of the container 3. It was discharged. The kenaf fiber discharged from the contact device 1 was placed in an oven set at 80 ° C. and dried until the moisture content became 5%.

(2) Production of fiber molded body (binding process)
The kenaf fiber obtained in the above (1) and the resin fiber obtained by spinning an olefin-based thermoplastic resin composed of a polypropylene homopolymer (melting point: 145 ° C.) were mixed to form a fiber mat. Specifically, the fiber mat was obtained by laminating the kenaf fiber and the resin fiber by a card method so that the mass ratio was 50:50.
The obtained fiber mat was heated using a hydraulic press machine until the temperature of the fiber mat reached 180 ° C. Thereafter, the fiber mat was taken out from the hydraulic press and cooled and compressed to obtain a plate-like fiber molded body (Example 1).

<2> Example 2
(1) Preparation of plant fiber (contact process and drying process)
As the plant fiber, a kenaf fiber defibrated from the plant body kenaf by letting was prepared. This kenaf fiber was immersed in an aqueous solution of sodium bicarbonate having a concentration of 20,000 ppm by mass for 1 minute. Thereafter, the contact device 1 used in Example 1 was used as a cleaning device, and water was sprayed from a spray tube (not shown) of the cleaning device. The kenaf fiber was stirred while being rotated in the container 3 by a blade 17 erected on the rotating shaft 15, and washed with water during that time. Then, the kenaf fiber was screwed as indicated by an arrow Y (see FIG. 2) from the inlet 7 to the outlet 11 while being washed with water, and discharged from the outlet 11 to the outside of the container 3. The kenaf fiber discharged from the cleaning device was placed in an oven set at 80 ° C. and dried until the moisture content became 5%.

(2) Production of fiber molded body (binding process)
The fiber molded body of Example 2 in the same manner as in Example 1 except that the kenaf fiber (1) (a kenaf fiber in contact with a 20,000 ppm sodium bicarbonate aqueous solution on a mass basis) was used. Got.

<3> Example 3
(1) Preparation of plant fiber (contact process and drying process)
Kenaf fibers were obtained in the same manner as in Example 2 except that the concentration of the aqueous sodium hydrogen carbonate solution was 5,000 ppm on a mass basis.
(2) Production of fiber molded body (binding process)
The fiber molded body of Example 3 in the same manner as in Example 2 except that the kenaf fiber of (1) (a kenaf fiber in contact with a 5,000 ppm sodium bicarbonate aqueous solution on a mass basis) was used. Got.

<4> Comparative Example 1
(1) Preparation of plant fiber (contact process and drying process)
In the same manner as in Example 1, a kenaf fiber brought into contact with an aqueous sodium hypochlorite solution was obtained.
(2) Production of fiber molded body (binding process)
The kenaf fiber obtained in the above (1) and the resin fiber obtained by spinning an olefin-based thermoplastic resin made of polypropylene homopolymer (melting point: 170 ° C.) were mixed to form a fiber mat. Specifically, the fiber mat was obtained by laminating the kenaf fiber and the resin fiber by a card method so that the mass ratio was 50:50.
The obtained fiber mat was heated using a hydraulic press machine until the temperature of the fiber mat reached 230 ° C. Thereafter, the fiber mat was taken out from the hydraulic press and cooled and compressed to obtain a plate-like fiber molded body (Comparative Example 1).

<5> Comparative example 2
(1) Preparation of plant fiber (contact process and drying process)
In the same manner as in Example 2, a kenaf fiber brought into contact with an aqueous sodium hydrogen carbonate solution having a concentration of 20,000 ppm by mass was obtained.
(2) Production of fiber molded body (binding process)
A fiber molded body (Comparative Example 2) was obtained in the same manner as in Comparative Example 1 using a homopolymer of polypropylene having a melting point of 170 ° C. as an olefinic thermoplastic resin.

<6> Comparative Example 3
(1) Preparation of plant fiber As a plant fiber, a kenaf fiber defibrated from a plant body kenaf by letting was prepared. That is, a kenaf fiber not subjected to the contact process was prepared.
(2) Production of fiber molded body (binding process)
Using a kenaf fiber not subjected to the contact step prepared in (1) above, and using a homopolymer of polypropylene having a melting point of 170 ° C. using an olefin-based thermoplastic resin, a fiber molded body (Comparative Example) 3) was obtained.

[2] Evaluation of Fiber Molded Body For the fiber molded bodies of Example 1-2 and Comparative Example 1-3 obtained in [1] above, the odor was evaluated as follows.
10 g of each fiber molded body obtained in the above [1] was cut out and put into odorless vinyl bags. Then, 10 g of water was poured into the bag and left at room temperature (temperature 25 ° C.) for 10 minutes. Then, the contents were taken out and five evaluators smelled each smell. Each evaluator evaluated (1) earthy odor and rot odor, (2) tobacco odor, and the presence or absence of the odor. And when all the odors of the above (1) or (2) were not detected, “◯” is shown in Table 1. In addition, when one or more people sense the odor of either (1) or (2) above, “Δ” is shown in Table 1. In addition, when one or more people sense both odors of (1) and (2), “x” is shown in Table 1.

表１中の「＊」は本発明の範囲外となる要素を示す。

“*” In Table 1 indicates an element that is outside the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1; Contact apparatus, 3; Container, 5: Rotating body, 3A; Upper part of container, 3B; Lower part of container, 7: Input port, 9: Guide plate, 11: Discharge port, 13: Drainage hole, 15; Blade, 19; bearing.

Claims (3)

A contact step of contacting a plurality of plant fibers defibrated by letting ( excluding plant fibers in which a self-adhesive component is generated) with an alkaline aqueous solution;
A drying step of drying the plurality of plant fibers that have undergone the contact step;
A plurality of plant fibers that have undergone the drying step, and a binding step of binding using an olefin-based thermoplastic resin having a melting point of less than 170 ° C. ,
The alkaline aqueous solution contains sodium hypochlorite,
The concentration of sodium hypochlorite in the alkaline aqueous solution is 1 ppm or more and 50 ppm or less on a mass basis,
In the binding step, in a state where the plurality of plant fibers that have undergone the drying step and the olefinic thermoplastic resin coexist, the whole is heated to a temperature of 200 ° C. or less, and the olefinic thermoplastic resin is heated. The manufacturing method of the fiber molded object characterized by including the process to fuse | melt . The manufacturing method of the fiber molded object of Claim 1 which does not comprise the washing | cleaning process which wash | cleans the said alkaline aqueous solution with water from the some plant fiber which passed through the contact process . In the contact step,
Container and said container
A rotating device provided rotatably inside, a contact device comprising:
The container is formed in a substantially cylindrical shape inside, and is divided into upper and lower halves on the container upper part and the container lower part,
The upper part of the container is provided with an inlet for introducing the plant fiber into the container on one end side in the longitudinal direction, and the vegetable fiber is placed in the container on the ceiling of the inner peripheral surface of the upper part of the container. Provided with a plurality of crescent-shaped guide plates for screwing,
The container lower part is provided with a discharge port for discharging the plant fiber on the other end side in the longitudinal direction, and the alkaline aqueous solution in contact with the plant fiber is discharged on the inner peripheral surface of the container lower part. A plurality of drain holes for discharging out of the container,
The rotating body is supported by a bearing of the container along the longitudinal direction of the container, and includes a rotating shaft led out of the container and a blade standing on the rotating shaft. , Is connected to a driving source through the rotating shaft and is rotatable.
The blade has a rectangular shape and uses a contact device whose long side is erected along the rotation axis.
When the plant fiber is introduced, the plant fiber is agitated while being rotated in the container by the movement of the blade rotated with the rotation of the rotating body and the guide plate, and is discharged from the input port. method for producing a fiber molded article according to, in claim 1 or 2 is a step to be contacted with the aqueous alkaline solution supplied to the vessel while it is screwed towards the outlet.

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