WO2018116500A1

WO2018116500A1 - Cement material reinforcing fiber

Info

Publication number: WO2018116500A1
Application number: PCT/JP2017/020895
Authority: WO
Inventors: 朋柿谷; 友紀子島川
Original assignee: 住友林業株式会社
Priority date: 2016-12-22
Filing date: 2017-06-05
Publication date: 2018-06-28

Abstract

A cement material reinforcing fiber of the present invention is made up of a lignocellulose fiber to which an antistatic agent is attached. Another cement material reinforcing fiber of the present invention is made up of a lignocellulose fiber to which a fiber surface coating agent is attached, the fiber surface coating agent being selected from the group consisting of a resin, a cellulose nanofiber, and a lignocellulose nanofiber. A fiber mixed cement material of the present invention comprises either one of said cement material reinforcing fibers and cement. This fiber mixed cement material preferably comprises small pieces of chopped lignocellulose material.

Description

Cement material reinforcement fiber

The present invention relates to a method for producing a fiber for cement material reinforcement, a fiber-mixed cement material, and a fiber-reinforced cement material.

The present invention also relates to a method for producing a compression-molded body of lignocellulose fibers, a compression-molded body produced by the production method, a method for using the same, and the like.

Cement is an important social infrastructure material that is inexpensive, has excellent strength and durability, and can be molded freely. Therefore, it is widely used for buildings, structures, building materials, etc. in the field of construction and civil engineering as materials having various characteristics and shapes such as concrete, mortar, cement board, foamed concrete and the like.
However, there are some problems with cement materials. Among them, the following two can be cited as typical examples.
The first problem is that the cement material itself is extremely poor in tensile resistance, so that it easily breaks against tensile stress associated with generation of external force such as drying shrinkage or earthquake. Once a crack occurs, the crack not only causes an appearance problem, but also causes rainwater intrusion and stress concentration. Rainwater intrusion causes corrosion of rebars, steel frames and other structural materials in concrete structures and the progress of neutralization of concrete, and stress concentration causes problems such as expansion of defects when stress occurs again Become.
The second is the response to environmental problems. In recent years, appropriate responses to environmental issues such as global warming have become increasingly important, and strict attention has been paid to cement materials that emit carbon dioxide. That is, the cement material is required to be devised to suppress the discharge of carbon dioxide or to store carbon dioxide in the material in some form for a long time at the time of use.

On the other hand, lignocellulosic resources derived from biomass, wood and non-wood plants accumulate carbon dioxide during plant growth and are recognized as carbon neutral materials that do not emit excess carbon dioxide when used or disposed of. Has been.
Lignocellulose resources obtained from wood and non-wood plants are composed of lignocellulose fibers. Lignocellulosic fiber breaks and unravels the intermediate layer that binds the fibers in an adhesive manner by mechanically, thermomechanically, chemically, chemically mechanically or chemically thermomechanically treating the lignocellulose resources. Can be obtained. The lignocellulosic fiber thus obtained is mainly used as pulp as a paper raw material or fiber as a fiberboard raw material.

As described above, the cement material has a drawback of exhibiting brittle properties. In order to improve this, research has been carried out to improve tensile stress and shock absorption by adding glass fibers and synthetic polymer fibers to cement materials. However, these fibers have an unfavorable aspect in that carbon dioxide is released due to the use of petroleum resources as a raw material, is not decomposed in the environment, or increases in weight.
On the other hand, using a plant-derived lignocellulose fiber to reinforce the cement material has also been limited to cement materials produced in factories.
For example, Patent Documents 1 to 7 describe a method of reinforcing a cement material using pulp or wood fiber.

Japanese Patent No. 1947309 Japanese Patent No. 2659806 Japanese Patent No. 2587306 Japanese Patent No. 1853706 Japanese Patent No. 1955557 Japanese Patent No. 2121236 Japanese Patent No. 2121258 US2002 / 0160174A1 Japanese Patent No. 4384411 Japanese Patent No. 5481066 Japanese Patent No. 5279125 Special table 2012-532040 JP 2012-161275 A JP 2009-051985

However, in lignocellulose fiber, cellulose, which is a constituent unit of the molecular chain of the fiber, has a plurality of highly polar hydroxyl groups, so it easily aggregates due to hydrogen bonding between fibers, and in addition, lignocellulose fiber is flexible. Due to its high nature, it tends to be a dull so-called fiber ball that is intricately entangled, and these have the disadvantage that they are not easily loosened.
Therefore, when adding lignocellulosic fiber to cement material, it has to be performed using a device (for example, a device called a pulper) that breaks a special fiber at a factory. In other words, lignocellulosic fibers could not be added in the case of a cement material that is usually kneaded with a simple device at the time of transportation to and from the site such as concrete and mortar.

In addition, there are cases where the agglomerated or entangled fibers can be loosened by mechanically stirring strongly in water. However, in that case, an excessive amount of water is required with respect to the amount of fiber, and when the amount of water to be added to the cement is limited to a very small amount, such as concrete and mortar, it is performed. The operation was not possible.
Here, in a factory, an excessive amount of water is once added, and a slurry composed of cement, fiber, and water is dehydrated in a subsequent process, so that an optimum water-cement ratio can be adjusted (reduced water). This is a so-called Hatcheck method, which is a method for manufacturing ceramic materials in a wet process. However, this operation cannot be performed at the site of construction or construction. Therefore, lignocellulosic fibers could not be added to cement materials that are kneaded with a simple device at the time of transportation to the field, such as concrete and mortar.
To describe the problem in more detail here, when lignocellulosic fibers are added during cement material preparation, that is, when kneading cement and water, the fibers remain agglomerated or become lumps and cannot be dispersed. If the fiber is not dispersed in the cement material, it does not show a reinforcing effect, but the portion becomes a defect and the physical properties of the material are lowered. Therefore, while using lignocellulosic fiber, there is no way to disperse it in the material without making this fiber lumpy, so adding lignocellulosic fiber to concrete or mortar to reinforce the material so far could not.

Patent Document 8 proposes a lignocellulose fiber-reinforced cement material. In the claims and the detailed description of the patent document 8, there is a possibility that the dispersibility of lignocellulosic fibers can be improved by adding potato starch or corn starch which is a cationic polymer that can be adsorbed or bound to the fiber material. (

Claims

3, 7, 8 and sentences 32, 33). This is a method usually used for improving the strength of paper, and it is empirically known that it has an effect of preventing aggregation of loose lignocellulose fibers. However, it does not help disperse the lignocellulose in a flocculated or damped state. In addition, Patent Document 8 does not disclose anything about the result of improving the dispersibility and the physical properties of the molded product by the addition, and the effect of the addition is only expected. Therefore, it is reasonable to interpret that it is not a scientific indication of whether it actually has an effect, and if it is, what kind of effect it is, and that it does not suggest a solution to the problem. .

In Patent Document 9, cellulose fibers are treated with a cationic surfactant, a quaternary ammonium salt, and the aggregation of cellulose fibers is eliminated by canceling the polarity of the negatively charged cellulose hydroxyl groups. Attempts have been disclosed. However, a water reducing agent is often added to materials such as cement and concrete, and since this is anionic, it cannot be used simultaneously with a cationic substance. Furthermore, quaternary ammonium salts are known to be corrosive to metals, which increases the possibility of corroding reinforcing bars, steel frames and other metal fasteners. In addition, this technology is intended to be used only when dewatering a slurry of cement, cellulose fibers, and water in a subsequent process by dispersing cellulose fibers using a large amount of water in a factory. It cannot be applied to mortar, concrete, etc., which cannot be dehydrated because it mainly involves kneading on site. Further, according to the method disclosed in this document, the composite material containing cement and cellulose fiber is heat-cured using an autoclave, and in that respect, mortar or concrete that cannot perform such a process. Etc. are different. Therefore, this patent document can be applied only to a very limited method under very limited conditions, and can be said to be different from the method to be solved in the present invention.
Further, Non-Patent Document 1 describes that the bending strength of mortar is improved by adding wood strips, but there is no mention of resistance to cracking.

An object of the present invention is to provide a fiber for reinforcing a cement material that uses plant-derived lignocellulose fibers and can effectively reinforce the cement material. Moreover, the subject of this invention is providing the fiber mixing cement material which can manufacture the high performance fiber reinforced molded object reinforced with the plant-derived lignocellulose fiber. Moreover, the subject of this invention provides the manufacturing method of the fiber reinforced cement material which can manufacture efficiently the fiber reinforced cement material which can form the high performance fiber reinforced molded object reinforced with the lignocellulose fiber derived from a plant. Is.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that fiber agglomeration and lumps can be easily loosened in water by treating lignocellulose fibers with an antistatic agent. In other words, one of the reasons why fiber aggregation and lumps are not unraveled is that electricity is not conducted and lignocellulosic fibers with a large specific surface area are rubbed together during the drying process, resulting in static electricity on the fiber surface. As a result, lignocellulosic fiber, which is originally hydrophilic, apparently behaves hydrophobicly without attracting water, so that it does not become familiar with water and inhibits the hydrophilicity and dispersion process of the fiber. It is a thing. In addition, the aggregation due to the high affinity between hydroxyl groups, which is another cause, improves the hydrophilicity of the fibers by improving the charging of the fibers, and utilizes an antistatic agent having a surface-active action (or By adding a surfactant separately), it is possible to loosen agglomeration and lumps in water. In other words, the present inventors have newly found that it can be effectively dispersed without using a strong cation such as a quaternary ammonium salt. Furthermore, by applying this knowledge as appropriate when kneading cement, water, and fibers, the lignocellulosic fibers can be agglomerated or damaged in the cement material without adding a special kneading device or an excessive amount of water (and then dehydrating). It was found that it can be uniformly dispersed in the absence of water.

The present invention has been completed based on the above findings and further studies.
The present invention provides a fiber for reinforcing a cement material, comprising a lignocellulose fiber to which an antistatic agent is attached.
The present invention also provides a fiber-mixed cement material comprising lignocellulose fibers, an antistatic agent and cement. The present invention also provides a fiber-mixed cement material comprising lignocellulosic fibers to which an antistatic agent is attached, and cement.
The present invention also includes a kneading step of mixing lignocellulosic fiber, antistatic agent, cement and water, and does not include a step of dehydrating after the kneading step, and a method for producing a fiber reinforced cement material Is to provide.
The present invention also provides a method for producing a fiber-reinforced cement material, characterized in that lignocellulose fibers and lignocellulosic material cutting pieces are added to the cement material (hereinafter, the present invention is referred to as the second method invention). Also called).
Moreover, this invention provides the fiber reinforced cement structure characterized by including the said fiber for cement material reinforcement.
Moreover, this invention provides the manufacturing method of a fiber reinforced cement structure characterized by including the kneading process which mixes lignocellulose fiber, an antistatic agent, cement, and water.

Moreover, what can be said in common to cement materials reinforced with pulp and wood fibers described in Patent Documents 1 to 7 is that a strong surface coating is applied on the premise that they are used outdoors. In other words, there is no use in which the base cement material itself is directly exposed to water. The reason is that when the cement material containing lignocellulose fiber repeats the process of water absorption and drying, the lignocellulose fiber repeats swelling and shrinking, whereas the cement material hardly swells and contracts. This is considered to be because the bonding point between the lignocellulose fiber and the cement is broken.

Also, as another problem, lignocellulosic fibers basically have a hollow cylindrical shape, and because of this shape, they exhibit high elastic behavior even if light. However, when water enters the inside of the hollow body together with the cement component, cement crystals gradually grow inside the hollow body (referred to as mineralization). As a result, lignocellulosic fibers lose their elastic properties and instead develop brittle properties. That is, the various physical property improvement effects based on the elastic properties of the lignocellulose fibers imparted by adding the lignocellulose fibers are reduced.

We think that the durability of the physical property improvement effect by adding lignocellulosic fiber can be improved by protecting the surface of mortar and concrete in some way, such as painting, and shielding the cement base from direct water. It is done.
However, when the cement base is not blocked from water, or even if measures are taken to block water, the function of blocking water is lost over time, and maintenance work to deal with it is not performed. Since the physical properties of lignocellulosic fibers are deteriorated, it is required to prevent this.

Non-Patent Document 2 discloses a method of treating lignocellulose fibers with a specific silane coupling agent. However, silane coupling agents are very expensive and difficult to handle.

Another object of the present invention is to provide a fiber for reinforcing a cement material that uses plant-derived lignocellulosic fibers, can effectively reinforce the cement material, and is excellent in durability of the reinforcing effect. Another object of the present invention is to provide a fiber-mixed cement material that is reinforced with plant-derived lignocellulosic fibers and that can produce a fiber-reinforced molded article having excellent water resistance and durability. Another object of the present invention is to provide a method for producing a fiber reinforced cement material capable of producing a fiber reinforced cement material reinforced with plant-derived lignocellulose fibers and capable of forming a fiber reinforced molded article having excellent water resistance and durability. To do.

As a result of intensive studies to solve the above problems, the present inventors have used a lignocellulosic fiber in which a resin is attached to a lignocellulosic fiber, preferably treated with a resin and cured with the resin component, Alternatively, the cellulose nanofiber and / or the lignocellulose nanofiber attached to the lignocellulose fiber is treated with the fiber, preferably the cellulose nanofiber and / or the lignocellulose nanofiber, and the cellulose nanofiber and / or the lignocellulose nanofiber is dried. It has been found that the use of the lignocellulose fiber thus produced greatly improves not only the initial water resistance / durability of the cement material but also the long-term water resistance / durability.

The present invention has been completed based on the above findings and further studies.
That is, the present invention comprises lignocellulose fibers to which a fiber surface coating agent is adhered, and the fiber surface coating agent is at least one selected from the group consisting of a resin, lignocellulose nanofibers and cellulose nanofibers. A fiber for reinforcing a cement material is provided.
Further, the present invention is a method for producing a fiber for reinforcing a cement material, wherein the fiber surface coating agent is a cellulose nanofiber and / or a lignocellulose nanofiber,
A liquid containing cellulose nanofibers and / or lignocellulose nanofibers is dried in a state where the liquid is in contact with the lignocellulose fibers, whereby lignocellulose fibers having the cellulose nanofibers and / or lignocellulose nanofibers attached to the surface are dried. The manufacturing method of the fiber for cement material reinforcement obtained is provided.
The present invention also provides a fiber-mixed cement material comprising the above-described cement material reinforcing fiber or the cement material reinforcing fiber obtained by the above method, and cement.
Further, the present invention includes a kneading step of mixing the cement material reinforcing fiber or the cement material reinforcing fiber obtained by the method, cement and water, and does not include a dehydrating step after the kneading step. The present invention provides a method for producing a fiber-reinforced cement material.

As described above, lignocellulose resources obtained from wood and non-wood plants are composed of lignocellulose fibers, which are mechanical, thermomechanical, chemical, and chemical mechanical. Alternatively, it can be obtained by breaking and unraveling the intermediate layer that bundles the fibers in an adhesive manner by chemical thermomechanical treatment.
The lignocellulosic fiber thus obtained is mainly used as pulp as a paper raw material or fiber as a fiberboard raw material. This is because lignocellulose fibers are lightweight, have high strength, and are highly elastic.

In order to solve environmental problems represented by global warming in recent years, the use of lignocellulosic fibers is expected as an alternative to glass fibers, synthetic resin fibers, metal fibers and asbestos fibers, which have been used in the past. Has been.
However, lignocellulose fibers are very bulky and typically have a bulk density of 30 to 50 kg / m ³ , so that they cannot be efficiently transported as they are. In addition, when mixed with the material to be reinforced as it is, dust easily rises, which may cause problems such as deterioration of the working environment and contamination of other materials and equipment.
In addition, when a fiber reinforced composite material is produced by mixing fibers with resin pellets, when mixing with resin pellets, if the lignocellulosic fibers are in the same state, the bulk density of the fibers and the resin is greatly different. There is a problem that a homogeneous fiber-reinforced composite material cannot be obtained because the resin pellets and fibers cannot be uniformly mixed with the resin pellets, or both cannot be supplied at a constant ratio.

In order to solve the above problem, it is considered preferable to compress the lignocellulosic fiber into a granular form such as a pellet.
As a technique for making lignocellulosic fibers into pellets, Patent Documents 10 to 12 disclose that a thermoplastic resin is added to lignocellulosic fibers, and the compression of the cellulose fibers is performed using a hot press method using the thermoplastic resin as a binder. A method is disclosed in which, after a plate is formed, the compressed plate is mechanically cut into small pieces and small grains called pellets or dies.
However, the methods described in Patent Documents 10 to 12 require large-scale equipment such as a hot press, and the pellets produced by the method are subjected to heat higher than the melting point of the resin used as the binder. There is a problem that it must be remelted and plasticized and not redispersed at room temperature. On the other hand, if a binder such as a thermoplastic resin is not added, the problem of difficulty in redispersion can be solved. However, lignocellulosic fibers have a very high elastic force or a strong elastic recovery force. However, when the fiber mass is simply compressed, when released from the compressive force, the fiber mass will elastically recover until it reaches a certain low bulk density.

As a conventional technique in a similar field, for example, as shown in Patent Document 13, in the case of a powder of lignocellulosic material, it is often pelletized and granulated by a device called a pelletizer. However, since the pelletizer pushes the object to be compressed to the nozzle provided on the die plate while grinding it with a mechanism like a stone mortar, the lignocellulosic fiber, which is long in the lengthwise direction, has a length. Becomes a wood powder cut short, which is not preferable as a reinforcing material.

On the other hand, as shown in Patent Document 14, a molding die is provided on the surface of two pairs of rollers, called a briquette manufacturing apparatus, and a powdery substance is introduced between the two pairs of rollers. 2. Description of the Related Art A granulating apparatus is known in which a powdery substance is compressed and molded between rollers by applying pressure while rotating in a meshing direction. According to this method, since the shearing force applied to the lignocellulose fiber at the time of compression molding is small, the lignocellulose fiber can be compression molded without being excessively powdered.
However, lignocellulosic fibers, the bulk density is typically 30 ~ 40kg / m ³ and very bulky, lighter, and since the fibers are long and flexible, forming a fiber ball fibers are intertwined Most of them do. For this reason, it is difficult to drop fibers or fiber bundles between rollers by gravity. There arises a problem that the toner is not supplied between the rollers of the roller, or is not supplied without some assistance. Therefore, it was difficult to continuously produce briquettes from lignocellulose fibers.

Therefore, the lignocellulosic fiber is granulated by continuously compressing and molding without using a binder added from the outside in order to substantially bond the fibers, and without making the fiber as powdery as possible. How to do it is required.

Therefore, the object of the present invention is to compress lignocellulosic fibers, which can efficiently compress and mold lignocellulose fibers derived from plants such as wood and non-wood, without substantially using a binder added from the outside. It is providing the manufacturing method of a molded object. Here, “without substantially using a binder” means that a resin binder intended to bind fibers is not added, and a resin or the like for treating lignocellulosic fibers for another purpose. Addition (for example, coating, etc.) means to allow.

Another object of the present invention is to provide a compression-molded body of lignocellulosic fibers that can be transported, stored and handled efficiently and economically and is excellent in the effect of improving the strength of a material to be reinforced.
Another object of the present invention is to provide a fiber-reinforced composite material that can efficiently blend lignocellulosic fibers derived from wood or non-wood plants with respect to the material to be reinforced, and that is excellent in improving the strength of the material to be reinforced. An object of the present invention is to provide a method for producing a fiber-reinforced composite material that can be efficiently produced.
Another object of the present invention is to provide a fiber-reinforced composite material that is reinforced with lignocellulosic fibers derived from wood or non-wood plants and is excellent in strength and durability.

As a result of intensive studies to solve the above problems, the present inventors have developed a multi-screw extruder that rotates lignocellulosic fibers so that multi-shaft bladed screws arranged in a housing mesh with each other. It was found that the above-mentioned problems can be solved by compressing and transferring the lignocellulosic fibers and discharging them from the discharge holes provided in the die.

Based on the above findings, the present invention has been further studied and completed the following inventions such as a compression molded product of lignocellulose fiber, a method for producing a fiber-reinforced composite material, and a fiber-reinforced composite material.
The present invention relates to a method for producing a compression molded product of lignocellulosic fibers used in a fiber-reinforced composite material, wherein the lignocellulosic fibers are introduced into a multi-screw extruder equipped with two or more screws, Cellulose fibers are forcibly transferred and compressed toward a die by screw blades meshing with each other in a plurality of screws, and the compressed product is discharged from a plurality of discharge holes provided in the die. The present invention provides a method for producing a compression molded product of lignocellulose fiber.

Moreover, this invention provides the compression molding body of the lignocellulose fiber manufactured by the said method.
Further, the present invention provides a fiber reinforced cement material as a fiber reinforced composite material by mixing a compression molded product of lignocellulose fiber produced by the above method with cement and water. A method for producing a reinforced composite material is provided.
Further, the present invention is characterized in that a compression-molded body of lignocellulose fibers produced by the above method is unraveled with a defibrating device and then mixed with a material to be reinforced to produce a fiber-reinforced composite material. The present invention provides a method for producing a fiber-reinforced composite material.
In addition, the present invention is characterized by producing a fiber reinforced resin composition as a fiber reinforced composite material by kneading a compression molded body of lignocellulose fiber produced by the above method and a molten resin. The present invention provides a method for producing a fiber-reinforced composite material.
Moreover, this invention provides the fiber reinforced composite material characterized by being reinforced using the compression molding body of the lignocellulose fiber manufactured by the said method.

FIG. 1 is a schematic view of an in-plane shear tester used in an in-plane shear test. FIG. 2 is a schematic view showing a multi-screw extruder which is an example of the multi-screw extruder used in the present invention. FIG. 3 is a perspective plan view of the two screws arranged in parallel with each other when viewed from above with the barrel omitted. FIG. 4 is an enlarged view showing a state in which the downstream surface of the die of the multi-screw extruder is viewed from the direction of arrow D in FIG.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
The fiber for reinforcing a cement material according to the present invention is made of lignocellulose fiber to which an antistatic agent is attached.
The fiber-mixed cement material of the present invention includes lignocellulose fibers, an antistatic agent and cement.
The manufacturing method of the fiber reinforced cement material of the present invention includes a kneading step of mixing lignocellulosic fiber, antistatic agent, cement and water, and does not include a step of dehydrating after the kneading step.

[Lignocellulose fiber]
The lignocellulosic fiber used in the present invention can be obtained by bonding a fiber by treating mechanically, thermomechanically, chemically, chemically mechanically, or chemically thermomechanically a wood or non-wood plant-derived lignocellulose material. It is a fiber that breaks and unravels the intermediate layers that are bound together. Such lignocellulosic fibers can be used without particular limitation. The wood may be coniferous or hardwood.
Examples of non-wood plant-derived lignocellulose fibers include walla pulp, bagasse pulp, reed pulp, kenaf pulp, linen pulp, ramie pulp, hemp pulp and the like.

As lignocellulosic fibers used in the present invention, for example, dissolving pulp, sulfite pulp, kraft pulp, semichemical pulp, chemiground pulp, refiner ground pulp, thermomechanical pulp, and groundwood pulp can be preferably used. As lignocellulosic fiber, it is preferable to use mechanical pulp or fiberboard fiber from the viewpoint of production efficiency and physical properties. Examples of mechanical pulp include refiner ground pulp, thermomechanical pulp, and groundwood pulp. From the same viewpoint, thermomechanical pulp is more preferable. Thermomechanical pulp also includes fiberboard fibers. The fiberboard fiber is a thermomechanical pulp in a broad sense, and is a relatively coarse fiber in a narrow sense.
Lignocellulose fibers, unlike bleached (deligenized) pulp, all contain lignin. A lignocellulose fiber may be used individually by 1 type, and may be used in combination of 2 or more type.

As a method for converting lignocellulosic material into lignocellulosic fibers, known methods can be used without particular limitation. For example, a conventional method for producing pulp, a conventional method for producing fiber for fiberboard, and the like are appropriately used. Can do.
As an example of a method for converting lignocellulosic material into lignocellulosic fiber, lignocellulosic material is crushed into chips and then steamed with a preheater or a press steamer while applying a pressure of about 1 to 10 Bar. A method for producing desired fibers by softening lignin and hemicellulose, which are constituents of the above, and using a disk-type blade while applying pressure in a pressure refiner to defibrate fibers or fiber bundles. Can do.
The lignocellulose fiber used in the present invention has a width of preferably 1 to 100 μm, more preferably 10 to 50 μm, and a length of preferably 0.1 to 50 mm, more preferably 1 to 5 mm. The length and width of such a fiber can be appropriately adjusted to a desired length and width by adjusting operating conditions such as a refiner disk interval.

Lignocellulose fibers are efficiently produced through the hydrothermal process as described above, and the resulting fibers are less damaged. In many cases, lignocellulosic fibers are dried for the purpose of improving transportation, storage, storage and handling.
As a method for drying lignocellulosic fibers, known methods can be used without any particular limitation. For example, wet lignocellulosic fibers are discharged onto a roller or wire as is done in the paper and pulp industry. Then, after dehydrating by suction or pressurization, the air flow in the tube where hot air is passed through the wet lignocellulosic fiber as is done in the method of heat drying or the production of fiber for fiberboard The method of heat-drying under can be mentioned. Such drying of lignocellulose fibers is preferably performed at 60 to 200 ° C., for example, more preferably 80 to 160 ° C., and still more preferably 100 to 140 ° C.

[Antistatic agent]
As the “antistatic agent” used in the present invention, those having an antistatic effect can be used without particular limitation. Antistatic effect is the effect of attracting moisture in the air to form a conductive water molecule layer, and the degree of antistatic effect is known methods such as surface resistivity, charged half-life, dirt chamber test, etc. Can be evaluated.
The antistatic agent preferably has an antistatic agent that satisfies the following criteria (1) or (2).
(1) The surface specific resistance defined in ASTM D257 is 10 ¹⁴ Ω or less. The surface resistivity defined in ASTM D257 is more preferably 10 ¹² Ω or less, and further preferably 10 ¹¹ Ω or less.
(2) The charged voltage half-life defined in JIS L1094 is 30 seconds or less. The charged half-life defined in JIS L1094 is more preferably 10 seconds or less, and even more preferably 5 seconds or less.

Examples of the antistatic agent used in the present invention include anionic and nonionic agents. As used herein, anionic refers to an anion (anionic) compound as the type of ion when dissolved in water, and nonionic refers to a nonionic compound that does not become an ion. As an antistatic agent, various compounds marketed as an antistatic agent, a surfactant having an antistatic effect, particularly a highly hydrophilic surfactant can be used.
As described above, a quaternary ammonium salt, which is a typical cationic compound, is not preferable because of its strong metal corrosiveness. In addition, when an anionic compound such as a water reducing agent is added to the cement material, a cationic material cannot be used at the same time. From such a viewpoint, the antistatic agent used in the present invention is preferably a surfactant type and not a cationic type, more specifically, an anionic or nonionic surfactant type. Antistatic agents are preferred, and nonionic surfactants are more preferred.
As a conventional common sense, it can be seen from the fact that cationized starch has been suitably used for lignocellulosic fibers and that strong cation is selected in Patent Document 9, other than cationic It is clear that this compound was practically not an option in improving the dispersibility of lignocellulosic fibers.

These antistatic agents can be used either water-based or water-insoluble, but in combination with other water-based additives, considering the processing efficiency when processing lignocellulosic fibers at a time, they may be water-based. preferable. However, even a water-insoluble antistatic agent can be used in combination with other aqueous additives by performing treatment such as emulsification.
Examples of the “anionic surfactant” that can be used as the antistatic agent used in the present invention include alkyl sulfonates, alkyl benzene sulfonates, and alkyl phosphates.
Examples of the “nonionic surfactant” that can be used as the antistatic agent used in the present invention include glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyldiethanolamine, hydroxyalkylmonoethanolamine, Examples include polyoxyethylene alkylamines, polyoxyethylene alkylamine fatty acid esters, polyoxyethylene sorbitan fatty acid esters, alkyl diethanolamides, and the like.
Polyoxyethylene sorbitan fatty acid esters are preferably mono-, di- or triesterized 1,4-, 1,5- or 3,6-sorbitan, ethylene oxide (EO), or ethylene oxide (EO) and propylene oxide. (PO) is obtained by addition condensation.

Examples of polyoxyethylene sorbitan fatty acid esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan dilaurate, polyoxyethylene sorbitan trilaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan dipalmitate, Polyoxyethylene sorbitan tripalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan distearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan diolate, polyoxyethylene sorbitan Triolate, polyoxyethylene sorbitan monoisostearate, polyoxyethylene sorbitan Isostearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan esters of mixed fatty acids, and the like. Examples of the polyoxyethylene sorbitan mixed fatty acid ester include sorbitan coconut oil fatty acid ester, monopalmitic acid polyoxyethylene sorbitan, and the like. As the polyoxyethylene sorbitan fatty acid esters, for example, polyoxyethylene sorbitan monolaurate is preferably used.
The above-mentioned antistatic agents may be used alone or in combination of two or more. Polyoxyethylene sorbitan fatty acid esters are preferred as antistatic agents, and are preferably attached to lignocellulose fibers regardless of whether they are antistatic agents.

As a method for using the antistatic agent, either a method in which lignocellulose fibers are treated with an antistatic agent in advance or a method in which lignocellulosic fibers are kneaded with cement and water can be used. .
As a method of treating lignocellulosic fibers with an antistatic agent in advance, a method of spraying an antistatic agent on wet lignocellulose fibers carried out from a defibrating apparatus (for example, a refiner) and then drying, or Examples thereof include a method in which wet lignocellulose fibers are immersed in a solution containing an antistatic agent and then dried. Or after drying lignocellulose fiber carried out from the defibrating apparatus, the method of spraying an antistatic agent or immersing in the solution containing an antistatic agent etc. can also be employ | adopted.
On the other hand, when kneading with cement material or water, it can be treated by mixing all of cement material, lignocellulose fiber, water, and antistatic agent. For the purpose of processing, it is more preferable to first mix water, surfactant and lignocellulose fiber and then add cement material.
The amount of the antistatic agent attached to the lignocellulosic fiber is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass in terms of the solid content of the antistatic agent relative to the dry lignocellulose fiber. More preferably, it is 0.5 to 2% by mass. The cement material reinforcing fiber according to the present invention is preferably in a state where an antistatic agent is partially attached to the surface of the fiber.

By adopting the above-described method of treating lignocellulose fibers with an antistatic agent, the cement material reinforcing fiber of the present invention comprising lignocellulose fibers with an antistatic agent attached thereto can be obtained.

In addition, the description regarding the fiber for cement material reinforcement to which the antistatic agent is attached, and the fiber mixed cement material and the fiber reinforced cement material using the same, which will be described below, is a second cement material described later unless otherwise contradicted. The same applies to reinforcing fibers, and fiber mixed cement materials and fiber reinforced cement materials using the same.

The cement material reinforcing fiber of the present invention may be sold alone or as a fiber-mixed cement material containing lignocellulose fiber, antistatic agent and cement. Cement material reinforcing fiber or fiber-mixed cement material is produced at the factory, and it is transported to the construction and civil engineering work sites in each region, where it is kneaded with other materials and water such as mortar and concrete. It is also preferable to use a reinforced cement material from the standpoint that a high-quality fiber-reinforced molded body can be produced while suppressing conveyance costs.

In addition, from the viewpoint of easy delivery of fiber-mixed cement material to the construction and civil engineering sites and reduction in the cost of transporting fiber-mixed cement material, the fiber-mixed cement material has a moisture content of 15% by mass or less. The mortar mix or concrete mix is preferable, and the moisture content is more preferably 10% by mass or less. In addition to cement, the mortar mix contains fine aggregates such as lignocellulosic fibers, antistatic agents and sand, and the concrete mix contains coarse aggregates such as lignocellulosic fibers, antistatic agents and gravel. Contains. The fiber-mixed cement material preferably contains lignocellulosic fibers to which an antistatic agent is attached as a lignocellulose fiber and an antistatic agent. As the fine aggregate and the coarse aggregate, known ones such as those defined in JIS A 1102 can be used.

[Cement material]
The cement material in the present invention is not particularly limited as long as it contains cement. Specific examples include concrete, mortar, and cement molding material. Examples of the cement molding material include wood piece cement board, wood wool cement board, siding board, slate board, and foamed concrete. The meaning of cement material and fiber reinforced cement material is not only the final product after water addition, but also the powder used as the raw material for producing the product (for example, water-free concrete mix powder mixture, water-free mortar Mixed powder mixture etc.). Furthermore, fly ash and blast furnace slag that are often used in recent years may be included.

[Other additives]
The fiber-mixed cement material and the fiber-reinforced cement material of the present invention include preservatives, insecticides, fungicides, water repellents, ultraviolet absorbers, flame retardants, fillers, cups as long as the effects of the present invention are not impaired. Various additives such as a ring agent, an elastomer, a polymer, an antifoaming agent, a lubricant, a pigment, a dye, a water reducing agent, a swelling agent, and a shrinkage reducing agent can be added. These may be used individually by 1 type and may be used in combination of 2 or more type.
Furthermore, glass fibers, synthetic resin fibers, carbon fibers, cellulose nanofibers, lignocellulose nanofibers, cellulose nanocrystals, carbon nanotubes, other nanofibers, and the like can be added as long as the object of the present invention is not impaired. This is because, in general, it is empirically known that when a plurality of types of fibers having different characteristics and shapes are combined, a preferable effect can be obtained as compared with the case where any one of them is used alone.

[Kneading method]
As a method of mixing the lignocellulosic fiber and the cement material, a known mixing method such as stirring by a mixer can be used.
What should be noted in the present invention is that aggregation of lignocellulosic fibers is eliminated and dispersed uniformly in the cement material unless a device that is mechanically vigorously stirred under excessive moisture is used. I could not. However, in the present invention, a cement material reinforcing fiber to which an antistatic agent is attached, or an ordinary concrete mixer that is not a special stirring device by mixing lignocellulose and water in the presence of the antistatic agent. The purpose can be achieved by using a mortar mixer without going through a dehydration step from the slurry.

The method for producing a fiber-reinforced cement material of the present invention includes a kneading step of mixing lignocellulose fibers, an antistatic agent, cement and water, and does not include a step of dehydrating after the kneading step. In the kneading step, it is preferable to knead small pieces obtained by cutting a lignocellulosic material described later in addition to the cement material reinforcing fiber, cement and water. According to the method for producing a fiber-reinforced cement material of the present invention, high-performance fiber reinforcement reinforced with plant-derived lignocellulose fibers by curing the mixture (fiber-reinforced cement material) after the kneading process at room temperature. A molded body can be manufactured. In addition, for the kneading of the mixture, it is possible to efficiently use the fiber-reinforced cement material without using a device that mechanically and vigorously stirs under excessive moisture, or after going through the dehydration process from the slurry. It can be manufactured.

The fiber-reinforced molded body may be a plate-shaped molded body or a molded body having a three-dimensional solid form. The molded product obtained by using the method for producing a fiber for reinforcing a cement material, a fiber-mixed cement material or a fiber-reinforced cement material according to the present invention corresponds to a fiber-reinforced molded product.
Examples of the plate-like fiber reinforced molded body include wood chip cement board, wood wool cement board, siding board, slate board, foamed concrete, and other concrete secondary products. The fiber reinforced molded body having a three-dimensional solid form may be a part of a building, for example, a concrete primary product such as a wall or floor of a concrete building, a conventional shaft assembly method or a two-by-four method. It may be a mortar wall in a wooden building. The wall of the building may be a wall having an opening for a window or a door.

The fiber reinforced molded body may be a fiber reinforced cement structure. The fiber reinforced cement structure may be a structure including fine aggregate and coarse aggregate, or may be a structure not including coarse aggregate.
The fiber reinforced cement structure includes a primary concrete product made by pouring ready-mixed concrete at a construction site, a secondary concrete product made in a factory using concrete as a material, and the like.
Examples of primary concrete products include the entire concrete building and parts thereof (walls and floors), concrete tunnels, and the like.
Secondary concrete products include utility poles, expressway columns and side grooves, wave-dissipating blocks, manholes, concrete piles, box culverts, segments used for tunnel inner walls, poles for traffic lights and distribution lines.

[Lignocellulose material cutting piece]
The cement material reinforcing fiber of the present invention (as well as the second cement material reinforcing fiber) is preferably used in combination with a small piece obtained by cutting a lignocellulosic material. The fiber-mixed cement material of the present invention preferably contains small pieces obtained by cutting the lignocellulosic material in addition to the lignocellulosic fiber, antistatic agent and cement, preferably cement material reinforcing fiber and cement. Further, in the method for producing a fiber reinforced cement material of the present invention, in addition to lignocellulosic fiber, antistatic agent, cement and water, preferably cement material reinforcing fiber, cement and water, a piece obtained by cutting the lignocellulose material is used. It is preferable to mix. Moreover, in the manufacturing method of the fiber reinforced cement material of 2nd method invention, the small piece which cut lignocellulose fiber and lignocellulose material is added to cement material.
In addition to lignocellulosic fibers, the addition of small pieces of lignocellulosic material cut from lignocellulosic materials, so-called flakes, wafers, strands, etc., improves the brittleness of the fiber reinforced molded product, etc. As compared with the case where lignocellulosic fiber is added alone, it can be greatly improved.

The “small piece of lignocellulosic material cut” used in the present invention (hereinafter referred to as lignocellulosic material-cut small piece) is produced with a flaker, a ring type or a disk type strand production device using wood or a plant other than wood as a raw material. Those that have been used can be used without particular limitation.
As examples of such lignocellulosic material cutting pieces, flakes for party quill boards, strands for wafer boards, and strands for oriented strand boards can be preferably used. One type of these lignocellulosic material cutting pieces may be used alone, or two or more types may be used in combination.

As a method of cutting lignocellulosic material into lignocellulosic material cutting pieces, known methods can be used without particular limitation. For example, a particle board manufacturing method, an oriented strand board, and a cutting piece for wafer board are used. A manufacturing method or the like can be used.
Examples of the above include a method in which the lignocellulose material is crushed into chips and then cut with a knife ring flaker, and a method in which the lignocellulose material is cut as it is with a ring-type strand manufacturing apparatus.
With respect to the shape of the cutting piece thus obtained, the width is preferably 1 to 50 mm, more preferably 2 to 20 mm. The length is preferably 1 to 50 mm, more preferably 2 to 20 mm. The thickness is preferably 0.2 to 1.0 mm, more preferably 0.3 to 0.6 mm.

The overall shape of the lignocellulosic material cutting piece is that the length of the fiber direction is the length and the direction perpendicular to the fiber direction is the width. From the standpoint of performance, it is preferable. The shape of such a cutting piece can be appropriately adjusted to a desired shape by adjusting the operating conditions of the flaker and the strand manufacturing apparatus.
Further, the size of the lignocellulose fiber cutting piece is appropriately changed depending on the purpose of use. For example, when added to mortar, the mortar composite material is applied to a reticulated base metal called a lath net. In this case, since the physical entanglement between the lath net and the mortar is important, the size of the lignocellulosic material cutting piece is determined by the size of the opening of the lath net. The same can be said for concrete, reinforcing bars and reinforcing wire mesh.
The lignocellulosic material cutting pieces are not treated with an antistatic agent, do not become lumps, and do not agglomerate, so the necessity of treatment is arbitrary.

The lignocellulosic fiber and the lignocellulosic material cutting piece may be added to the cement material at separate stages or may be added at the same stage. The case of adding together is preferable because the process can be simplified. In that case, lignocellulose fibers and lignocellulose material cutting pieces are mixed in a desired ratio in advance, and it may be added, More preferably, it is more preferable to add a mixture obtained by compression solidification or granulation such as pellets in order to improve lightness, workability, and work environment.

Further, the present invention comprises a lignocellulosic fiber to which a fiber surface coating agent is attached as a fiber for reinforcing a cement material, and the fiber surface coating agent is selected from the group consisting of a resin, lignocellulose nanofiber and cellulose nanofiber. The present invention provides the second fiber for reinforcing a cement material, which is one or more kinds.
The lignocellulose fiber in the second cement material reinforcing fiber may be a lignocellulose fiber to which the above-mentioned antistatic agent is not attached, but is preferably a lignocellulose fiber to which the above-mentioned antistatic agent is attached. . That is, in addition to the antistatic agent described above, lignocellulosic fibers to which the fiber surface coating agent is attached are preferred.

Examples of the second cement material reinforcing fiber include the following.
The cement material reinforcing fiber of the first embodiment is made of lignocellulosic fiber to which a fiber surface coating agent is attached, and the fiber surface coating agent is a resin.
The fiber for reinforcing cement material according to the second embodiment of the second embodiment is composed of lignocellulose fibers to which a fiber surface coating agent is attached, and the fiber surface coating agent is cellulose nanofiber and / or lignocellulose nanofiber.

The resin, lignocellulose nanofiber, cellulose nanofiber, and the like used for the second cement material reinforcing fiber will be described.
〔resin〕
The resin as the fiber surface coating agent improves the durability of the reinforcing effect of the cement material, and expresses one or more of the following (1) and (2), more preferably both functions.
(1) A material that adheres to the surface of lignocellulosic fibers and can suppress swelling of the lignocellulose fibers due to water absorption or moisture absorption.
(2) A material that adheres to the surface of the lignocellulose fiber and can prevent the cement component from entering the hollow portion of the lignocellulose fiber.

The resin as the fiber surface coating agent is a thermosetting resin from the viewpoint of improving the durability of the reinforcing effect, and is preferably attached to the fiber surface in a cured state.
In addition, the resin as the fiber surface coating agent is a water-soluble thermosetting resin, and the lignocellulosic fiber is efficiently attached to the thermosetting resin in a state of an aqueous solution by various methods such as spraying. This is preferable.
The resin used as the fiber surface coating agent is preferably at least one selected from the group consisting of amino resins, polyacrylamide resins, and polyacrylamide resin derivatives from the viewpoint of improving the durability of the reinforcing effect. These resins are water-soluble thermosetting resins.
An amino resin is a general term for resins obtained by a condensation reaction between a compound containing an amino group and an aldehyde. Examples of amino resins include urea-formaldehyde resins, melamine-formaldehyde resins, melamine-urea-formaldehyde resins, and derivatives thereof.
Moreover, considering that the cement material is mainly used outdoors, the resin used as the fiber surface coating agent is preferably a polyacrylamide resin or a derivative thereof from the viewpoint of durability.
Moreover, since the hydroxyl group of an lignocellulose fiber is anionic, when a polyacrylamide resin is used, it is preferable to use a cationic one because of its high adhesion and residual strength to the lignocellulose fiber. When anionic or amphoteric ones are used, it is preferable to use a spreading agent such as aluminum sulfate in combination.
Here, anionic means that it is an anionic (anionic) compound as a kind of ions when dissolved in water.
Resin can be used individually by 1 type or in combination of 2 or more.

[Method of processing resin into fibers]
As a method of treating lignocellulosic fibers with a resin (a method of attaching a resin to lignocellulosic fibers), a solution containing a resin is sprayed on wet lignocellulose fibers carried out from a defibrating apparatus (for example, a refiner), The method of drying after that, or the method of immersing the lignocellulose fiber in a wet state in a solution containing a resin and then drying it may be mentioned. Or the method of spraying the liquid containing resin, or immersing in the solution containing resin after drying the lignocellulose fiber carried out from the defibrating apparatus can also be mentioned. The solution containing the resin is preferably an aqueous solution in which the solvent is water, but the solvent may be a mixture of water and another liquid such as alcohol, or may be a liquid other than water such as alcohol. good. Examples of the alcohol include methanol, ethanol, and denatured alcohol. Further, instead of the solution containing the resin, the lignocellulosic fiber may be brought into contact with the dispersion containing the resin by spraying, dipping, or the like. The solvent or dispersion medium is preferably a liquid containing 50% by mass or more of water, and more preferably water.

By contacting the lignocellulosic fiber with a resin-containing solution and then drying, a cement material reinforcing fiber firmly adhered to the surface of the fiber in a cured state of the resin is obtained. Such a fiber for reinforcing a cement material is further excellent in sustainability of the reinforcing effect of the cement material.
When the resin is a thermosetting resin, it is more excellent in sustainability of the cement material reinforcing effect when the resin is heated to a temperature higher than the curing temperature of the thermosetting resin when the solution is dried or after the solution is dried. It is preferable from the viewpoint of obtaining fibers for reinforcing cement material, and it is further preferable from the viewpoint of production efficiency and the like that the drying temperature is set to be equal to or higher than the curing temperature of the thermosetting resin, and the solution drying and the resin thermosetting are simultaneously performed.
Since the adhesion amount of the resin to the lignocellulose varies depending on the resin, a desired adhesion amount can be appropriately selected. For example, the amount of the resin is preferably 0. It is 1 to 20% by mass, more preferably 0.2 to 10% by mass, and still more preferably 0.5 to 2% by mass. The cement material reinforcing fiber of the first embodiment may be entirely coated with a resin, or may be partially covered with a resin.

[Cellulose nanofibers, lignocellulose nanofibers]
Cellulose nanofibers and lignocellulose nanofibers used in the present invention are made from a material such as pulp containing cellulose fibers by nano-fabrication into nanofibers having a fiber size of nanosize level (less than 1 micron). The miniaturization treatment can be performed by any method selected from, for example, a high-pressure homogenizer, a grinder, a grinder, a refiner, and the like. Cellulose nanofibers are nanofibers obtained from materials that do not contain lignin, such as kraft pulp, and are substantially free of lignin. On the other hand, lignocellulose nanofibers are nanofibers produced from pulp containing lignin without delignification or by adjusting the amount of lignin contained, and contain lignin. The cellulose nanofiber has a lignin content of preferably less than 10% by mass, more preferably less than 5% by mass, and the lignocellulose nanofiber has a lignin content of preferably 10% by mass or more. The amount is preferably 10 to 50% by mass.

In the present invention, only one of cellulose nanofibers and lignocellulose nanofibers may be used as the fiber surface covering material, and both cellulose nanofibers and lignocellulose nanofibers may be used. Furthermore, the resin described above can be used in combination with cellulose nanofibers and / or lignocellulose nanofibers. Hereinafter, both cellulose nanofibers and lignocellulose nanofibers are collectively referred to as (ligno) cellulose nanofibers.
The (ligno) cellulose nanofiber used in the present invention has an average fiber diameter of preferably 1 to 500 nm, more preferably 10 to 100 nm, still more preferably 20 to 50 nm.
The average fiber length of the (ligno) cellulose nanofiber is preferably 1 to 5000 μm, more preferably 2 to 4000 μm, still more preferably 3 to 3000 μm.

The (ligno) cellulose nanofiber as the fiber surface coating agent improves the sustainability of the cement material reinforcing effect, and expresses one or more of the following (1) and (2), preferably both functions. .
(1) A material that adheres to the surface of lignocellulosic fibers and can suppress swelling of the lignocellulose fibers due to water absorption or moisture absorption.
(2) A material that adheres to the surface of the lignocellulose fiber and can prevent the cement component from entering the hollow portion of the lignocellulose fiber.

[(Ligno) Cellulose Nanofiber Processing Method]
As a method of treating lignocellulose fibers with (ligno) cellulose nanofibers (method of attaching (ligno) cellulose nanofibers to lignocellulose fibers), wet lignocello carried out from a defibrating device (for example, a refiner) is used. A method of spraying a liquid containing (ligno) cellulose nanofibers on cellulose fibers and then drying, or a method of immersing a lignocellulose fiber in a wet state in a liquid containing (ligno) cellulose nanofibers and then drying the liquid Can be mentioned. Or after drying the lignocellulose fiber carried out from the defibrating apparatus, the method of spraying the liquid containing (ligno) cellulose nanofiber or immersing the liquid containing (ligno) cellulose nanofiber etc. can be mentioned. .
The lignocellulose fiber-containing liquid of (ligno) cellulose nanofiber that is brought into contact with the lignocellulose fiber by spraying, dipping or the like is usually a dispersion of cellulose nanofiber and / or lignocellulose nanofiber.
The dispersion medium of the lignocellulose nanofiber and / or lignocellulose nanofiber dispersion is preferably water, but is a mixture of water and another liquid such as alcohol, or a liquid other than water such as alcohol. Also good. The dispersion medium is preferably a liquid containing 50% by mass or more of water, and more preferably water. Examples of the alcohol include methanol, ethanol, and denatured alcohol.

The lignocellulose fiber is brought into contact with the liquid containing the (ligno) cellulose nanofiber and then dried to obtain a cement material reinforcing fiber in which the (ligno) cellulose nanofiber is firmly attached to the surface of the fiber. Such a fiber for reinforcing a cement material is further excellent in sustainability of the reinforcing effect of the cement material.
The amount of (ligno) cellulose nanofiber attached to the lignocellulose fiber is preferably 0.1 to 10% by mass in terms of the solid content of the (ligno) cellulose nanofiber, based on the mass of the lignocellulose fiber in the dry state. More preferably, it is 0.2 to 5% by mass, and still more preferably 0.5 to 2% by mass. In the fiber for reinforcing cement material according to the second embodiment, the entire fiber surface may be coated with (ligno) cellulose nanofibers, or the fiber surface is partially coated with (ligno) cellulose nanofibers. It may be in the state.

[Cement material reinforcing fiber using second cement material reinforcing fiber]
By adopting the above-mentioned method for treating lignocellulose fibers with a resin, or the above-mentioned method for treating lignocellulose fibers with cellulose nanofibers and / or lignocellulose nanofibers, fibers, cellulose nanofibers and lignocellulose nanofibers can be used. A second cement material reinforcing fiber made of lignocellulosic fibers to which at least one selected from the group is attached is obtained.

In addition, from the viewpoint of easy delivery of fiber-mixed cement material to the construction and civil engineering sites and reduction in the cost of transporting fiber-mixed cement material, the fiber-mixed cement material has a moisture content of 15% by mass or less. The mortar mix or concrete mix is preferable, and the moisture content is more preferably 10% by mass or less. The mortar mix contains fine aggregates such as sand in addition to the cement material reinforcing fibers and cement, and the concrete mix contains coarse aggregates such as gravel in addition to the cement material reinforcing fibers and cement. The fiber-mixed cement material preferably includes a cement material reinforcing fiber to which an antistatic agent is attached as a cement material reinforcing fiber.

The second reinforcing fiber for cement material is that the antistatic agent is attached to the lignocellulose fiber in addition to the resin, cellulose nanofiber, and fiber surface coating agent that is at least one of cellulose nanofiber. It is preferable from the viewpoint of improving the dispersibility of water and the like during material preparation, and improving the strength and durability of the fiber-reinforced cement material and the fiber-reinforced molded body. One antistatic agent may be used alone, or two or more antistatic agents may be used in combination. Polyoxyethylene sorbitan fatty acid esters are preferable as antistatic agents, and it is preferable to adhere to lignocellulosic fibers in addition to the fiber surface coating agent, regardless of whether or not they are antistatic agents.

The method of using the antistatic agent is a method of treating the above lignocellulose fiber with a resin or a method of treating the above lignocellulose fiber with (ligno) cellulose nanofiber, and spraying and dipping a liquid containing a fiber surface coating agent. When the lignocellulose fiber is brought into contact with the liquid, an antistatic agent is preferably contained in the liquid. Thereby, the 2nd fiber for cement material reinforcement to which the antistatic agent has adhered to the lignocellulose fiber in addition to the fiber surface coating agent is obtained. The amount of the antistatic agent attached to the lignocellulosic fiber is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass in terms of the solid content of the antistatic agent relative to the dry lignocellulose fiber. More preferably, it is 0.5 to 2% by mass.

In addition, the second cement material reinforcing fiber, particularly lignocellulosic fiber, eliminates the aggregation of lignocellulosic fiber by using the cement material reinforcing fiber to which an antistatic agent is attached in addition to the fiber surface coating agent. It becomes easy to uniformly disperse the fiber for reinforcing the cement material into the cement material. Thus, for example, the use of a device that mechanically and vigorously stirs under excess moisture for kneading the mixture, or afterwards, the fiber reinforced cement material is made efficient without going through a dehydration process from the slurry. Can be manufactured. Moreover, the objective can be achieved without using a normal concrete mixer or mortar mixer, which is not a special stirring device, without going through a dehydration step from the slurry.

In a preferred embodiment of the method for producing a compression molded product of lignocellulosic fibers of the present invention (hereinafter also referred to as “method for producing the compression molded product of the present invention”), the lignocellulose fiber is a multi-screw extruder described below. To produce a compression molded body in which lignocellulose fibers are compressed and molded as an aggregate. As the lignocellulose fiber, those described above as the lignocellulose fiber used in the present invention can be used, and the above description is also applied to preferable lignocellulose fibers.

[Multi-screw extruder]
In the present invention, a multi-screw extruder equipped with two or more screws is used to obtain a compression molded product of lignocellulose fibers. The multi-screw extruder in the present invention includes a twin-screw extruder having two screws and a multi-screw extruder having three or more screws.
FIG. 2 shows a multi-screw extruder 1 that is an example of a multi-screw extruder preferably used in the present invention. In the multi-screw extruder 1, a plurality of screws 3 (only one is shown) are arranged in a barrel 2A so as to be rotatable in parallel with screw shafts 31 as rotation axes thereof being parallel to each other. Each of the screw shafts 31 is provided with screw blades 32 that mesh with each other, as shown in FIG.
The multi-screw extruder 1 includes, for example, an electric motor as a drive source 4 for the plurality of screws 3. Power is transmitted from the drive source 4 to the screw shafts 31 of the plurality of screws 3 such as a gear mechanism. Each of the plurality of screw shafts 31 is rotated by being transmitted through the system 5.

In order to produce a compression-molded body of lignocellulose fibers using the multi-screw extruder 1 shown in FIG. 2, when the lignocellulose fibers A are charged into the raw material charging unit 6 while rotating the plurality of screws 3, By rotation of the screw 3, the lignocellulose fiber A is forcibly drawn into the meshing space of the screw blade 32, and the lignocellulose fiber is forcibly transferred and compressed toward the die 7 side having the discharge hole 71 as it is.
The lignocellulose fiber A is compressed in a softened state by the heat generated by the forced transfer and compression and the water vapor generated by the heat, and the compressed product of the lignocellulose aggregate in which the bulk density is greatly reduced. And discharged from a plurality of discharge holes 71 provided in the die 7. The compressed product discharged from the discharge holes 71 is a compression molded body of substantially cylindrical lignocellulose fibers corresponding to the cross-sectional shape of the discharge holes 6.

Thus, in a preferred embodiment of the present invention, lignocellulosic fibers derived from wood or non-wood plants are transferred and compressed using the multi-screw extruder 1 equipped with two or more screws, and the compression is performed. In order to produce a compression molded body of lignocellulosic fiber by discharging the product from the discharge hole 71, the lignocellulosic fiber is efficiently compressed and molded without substantially using a binder added from the outside, A compression molded body of lignocellulose fibers can be obtained.
More specifically, if a mechanism for rotating the bladed screws arranged side by side in the direction of meshing with each other is used, 1) between the lignocelluloses generated by the rotation of the bladed screws in the direction of meshing with each other, or The fibers are softened by the frictional heat generated between the lignocellulose and the bladed screw, and the fiber-bound water originally held by the fibers is easily vaporized by the temperature rise. As a result, the lignocellulosic fibers are efficiently compressed in the softened state in the multi-screw extruder 1, and new hydrogen bonds are generated between the lignocellulosic fibers of the compressed product discharged from the discharge holes 71. Will be. By such an action, it is possible to obtain a compression molded body of lignocellulose fiber without substantially adding an external binder.
Further, when a stone mill type compression / extrusion mechanism such as found in a pelletizer used in Patent Document 13 is adopted, lignocellulosic fibers are sheared and become powdery. As in the embodiment, under the compression method using a multi-screw extruder, excessive shearing force is not generated on the fiber, and the lignocellulosic fiber becomes wood flour and the performance as a reinforcing material is greatly reduced. Can be prevented.

In addition, in the case of a two-pair roller system such as the briquette manufacturing apparatus used in Patent Document 14, excessive shearing of the fiber is not observed, but a bridge is generated inside the roller entrance and the supply apparatus, making the mechanism complicated. Therefore, it is difficult to continuously compress and mold without using any auxiliary pushing mechanism, but when a multi-screw extruder is used as in this embodiment, the bladed screws mesh with each other. By rotating in the direction, the lignocellulosic fiber is automatically pulled in, so no bridging occurs, and the lignocellulosic fiber is continuously supplied, compressed and molded to efficiently produce a compression molded product of lignocellulose fiber. can do.

Moreover, in the compression molding of the lignocellulose fiber manufactured using the multi-screw extruder 1 like this embodiment, when the lignocellulose fiber is compressed efficiently, the multi-screw extruder 1 The bulk density is greatly reduced as compared with that before being put in, and it has a shape formed as a compression-molded body, making it difficult for the fibers to scatter. Further, as described above, since the lignocellulosic fiber can be compressed and molded without excessive fiber breakage, the performance as a reinforcing material is not greatly deteriorated.
Therefore, the compression molded product obtained by the method for producing a compression molded product of lignocellulose fiber of the present invention and the compression molded product of lignocellulose fiber of the present invention can be transported, stored and handled economically and efficiently. Moreover, it is excellent in performance as a reinforcing material, and a high-performance fiber-reinforced composite material or a cured product thereof can be obtained.

The multi-screw extruder 1 may be provided with three or more screws 3, but in consideration of economic and technical convenience, it may be a twin-screw extruder. preferable. Multi-screw extruders include a counter-rotating extruder in which the screw shaft rotates in a different direction and a co-rotating extruder in which the screw shaft rotates in the same direction. The multi-screw extruder used in the present invention is preferably a counter-rotating extruder, more preferably a counter-rotating twin-screw extruder. Further, in the multi-screw extruder, it is preferable that a meshing portion of two screw blades is present immediately below the raw material charging unit 6, and in each of the meshing portions, each of the two screw blades is viewed from above. It is preferable to move downward. Also, as shown in FIG. 3, the two screws 3 have a distance between the two adjacent screw shafts 31 directly below the raw material charging unit 6 in the other part, preferably downstream (see FIG. It is preferable to have the biting introduction part 33 wider than the part located in the middle left). By having such a bite introducing part 33, the lignocellulose fiber can be taken into the multi-screw extruder 1 more smoothly. Therefore, lignocellulosic fibers having a low bulk density are prevented from staying in the vicinity of the raw material charging part 6 by forming a bridge. In addition, the mechanism may have an inclined structure in which the distance between the two adjacent screw shafts 31 is gradually or stepwise narrowed so that the raw material charging unit 6 is wide and the discharge unit is narrowed.

The compression-molded body of lignocellulose fibers to be produced preferably has a bulk density of 100 to 800 kg / m ³ and 200 to 500 kg / m ³ from the viewpoint of improving transportation, storage and handling properties. Further preferred. Moreover, the bulk density of the lignocellulosic fiber to be produced is 2 in comparison with the bulk density of the lignocellulosic fiber before compression molding, that is, the bulk density of the lignocellulose fiber before being fed into the multi-screw extruder. It is preferably 5 to 20 times, and more preferably 5 to 12.5 times.
Moreover, a bulky thing can be used as a lignocellulosic fiber used as the raw material of the compression molding body of a lignocellulose fiber, for example, the bulk density of the lignocellulosic fiber before compression molding is less than 100 kg / m < ³ >, for example. And preferably 10 to 60 kg / m ³ .

Here, the bulk density before compression molding of the lignocellulose fiber (bulk density of the raw material) and the bulk density of the compression molded product of lignocellulose fiber are measured by the following methods, for example.
<Method for measuring bulk density>
After the lignocellulosic fiber is put into a graduated cylinder having a capacity of 50 ml, the graduated cylinder is lifted by about 50 mm and dropped by its own weight, so that the contents are settled so as to fill a gap in the graduated cylinder. While repeating this operation 10 times, the upper part of the fiber is made flat using a glass rod or the like. When the fiber capacity reaches 50 ml, the mass of the fiber is measured and divided by 50 ml to obtain the bulk density. If there is an excess or deficiency in the amount of fibers, the fibers should be removed or added and adjusted accordingly. It is desirable to calculate the average value by repeating the same operation a plurality of times (for example, three times). Note that the bulk density is determined by the same operation for the compression molded body. However, when the size of the compression molded body is larger than the 50 ml graduated cylinder, it is desirable to change the size of the graduated cylinder.

In the method for producing a compression molded product of lignocellulosic fiber of the present invention, the lignocellulosic fiber can be introduced into a multi-screw extruder alone without substantially using a binder added from the outside. A compression-molded body having excellent retentivity is obtained. Here, “singlely without substantially using a binder” means that a resin binder intended to bind fibers is not added as described above, and lignocellulosic fibers are treated for another purpose. Addition of resin or the like (for example, coating) is permitted. For example, in order to improve the uniform mixing characteristics when the finished lignocellulosic fiber compression molding is mixed with a reinforcing material such as cement material or synthetic resin in order to obtain a fiber reinforced composite material, A small amount of water-soluble resin or thermosetting resin may be adhered to the lignocellulosic fiber before being put into the machine.
However, the content of the type of resin not originally contained in the lignocellulosic fiber is 10% by mass or less based on the total mass of all materials (excluding moisture) of the compression-molded body to be charged into the multi-screw extruder. Is preferable, and it is more preferable that it is 5 mass% or less.

From the viewpoint of accelerating softening and formation of hydrogen bonds in a compressed state in a multi-screw extruder, and obtaining a compression-molded body excellent in shape retention in a compressed state without using a binder, a multi-screw extruder The lignocellulosic fiber charged into the water content is preferably 1% or more, more preferably 5% or more. On the other hand, if the amount of water is too large, the inconvenience that the shape retention of the compressed product is too strong tends to occur. Therefore, the water content of the lignocellulose fiber to be input is preferably 1 to 100%, more preferably 5 to 50% or less.

The water content of the lignocellulose fiber (the water content of the raw material) is measured by the following method.
<Method for measuring moisture content>
An appropriate amount (for example, a mass of about 20 to 100 g) of lignocellulose fiber is put in a drier at a temperature of 105 ° C. and dried until the mass reaches a constant weight. (Mass after drying) is measured.
The mass before being put in the dryer is defined as “mass before drying”, and the moisture content (%) is obtained by the following formula.
Water content (%) = [(mass before drying−mass after drying) / mass after drying] × 100

In addition, the multi-screw extruder may be one having a heater on the outer peripheral portion of the barrel, and the lignocellulosic fiber in the barrel is produced when the compression molded product of lignocellulose fiber according to the present invention is produced. It can also be heated from the outside. However, as described above, the lignocellulosic fiber is heated by the frictional heat generated in the barrel, so that it is not necessary to perform external heating by the heater. Regardless of whether or not external heating is performed, lignocellulosic fibers are compressed in a multi-screw extruder from the viewpoint of obtaining a compression-molded article excellent in softening of lignocellulosic fibers and shape retention in a compressed state. The maximum temperature reached by the cellulose fibers is preferably 40 to 190 ° C., particularly 50 to 100 ° C., from the viewpoint of obtaining a compression-molded article excellent in softening of the lignocellulose fibers and excellent shape retention. The lignocellulosic fiber compressed in the multi-screw extruder can be adjusted by turning on / off the heater, the output of the heater, the rotational speed of the screw, the cross-sectional area of the discharge hole 71, and the like.

As shown in FIGS. 2 and 4, the multi-screw extruder 1 shown in FIG. 2 is provided with a compression molded body of lignocellulose fiber discharged from the discharge hole 71 of the die 7 on the downstream side of the die 7. A compression molded body B of lignocellulose fibers having a size adjusted by cutting by the cutting mechanism 8 can be obtained.
As the cutting mechanism 8, various known cutting mechanisms that can achieve the object can be used without particular limitation. For example, a rotary cutter mechanism as shown in FIG. 4 is simple and preferable. The cutter mechanism shown in FIG. 4 includes a plurality of cutting blades 81 that rotate along a plane orthogonal to the screw axis, and each of the cutting blades 81 is discharged from a plurality of discharge holes 71 provided in the die 7. The substantially cylindrical compression molded body is cut while rotating. The dice 7 may be block-shaped instead of plate-shaped. The discharge hole 71 shown in FIG. 2 has a cylindrical discharge-side opening protruding from the downstream surface 72 of the die 7, but the discharge side of the discharge hole 71 is formed on the downstream surface of the die 7. The opening may be open.

In addition, by appropriately adjusting the number, size and shape of the discharge holes 71 provided in the die 7, it is possible to change the density, hardness, shape and size, and productivity of the compression molded product of lignocellulose fiber. it can. Further, various combinations can be made by combining with a cutting mechanism.
From the viewpoint of handling properties (ease of handling), it is preferable that each compression-molded body whose size is adjusted is in the form of pellets. As used herein, “pellet-like” means that the aggregate of lignocellulosic fibers has a small lump-like form (regardless of regular shape or irregular shape).
The compression molded product of lignocellulosic fibers preferably has some space between the fibers in terms of dispersibility in the material to be reinforced.
In FIG. 4, reference numeral 73 denotes a bolt for fixing the die plate (die).

[Fiber-reinforced composite materials]
The compression-molded body of lignocellulosic fiber is variously reinforced with lignocellulosic fiber by blending into a reinforcing material such as cement material or resin composition having a known composition except that the lignocellulose fiber is not blended. The fiber-reinforced composite material can be obtained.
The fiber-reinforced composite material of the present invention is not particularly limited as long as it is produced using a compression molded body of lignocellulose fiber. Specific examples of the fiber reinforced composite material include a fiber reinforced cement material, a fiber reinforced asphalt composite material, and a fiber reinforced resin material.
Examples of fiber reinforced cement materials include concrete composite materials, mortar composite materials, and cement-molded composite materials. Examples of cement-molded composite materials include wood chip cement boards, wood wool cement boards, siding boards, slate boards, and foamed concrete. Is mentioned.
In the meaning of the composite material, not only the final product but also the raw material for manufacturing the product, such as a mixture of cement powder and the present lignocellulose fiber pellet, a mixture of resin pellet and the present lignocellulose fiber pellet, etc. Needless to say.
Furthermore, the utilization method which makes a composite material a component, for example, the wall structure of fiber reinforced concrete and mortar, the roadbed structure of fiber reinforced asphalt, and the molding of fiber reinforced resin are also included.

[Mixing method]
As a method for blending the compression-molded body of lignocellulose fibers into the material to be reinforced, any method capable of mixing both can be used without particular limitation. When a fiber reinforced cement material as a fiber reinforced composite material is produced using a compression molded body of lignocellulose fiber, the compression molded body of lignocellulose fiber may be mixed with cement and water. As a mixing method thereof, for example, stirring by a mixer or the like can be used.
As a method of mixing the compression-molded body of lignocellulose fibers with an asphalt material or a resin (plastic) material, any method that can mix lignocellulose fibers with an asphalt material or a resin can be used without particular limitation. In the case of producing a fiber-reinforced resin-based material as a fiber-reinforced composite material using a compression-molded body of lignocellulose fibers, the compression-molded body of lignocellulose fibers may be kneaded with a molten resin. As a method of kneading a compression molded product of lignocellulose fibers and a resin in a molten state, the compression molded product of lignocellulose fibers and resin pellets are introduced into a single-screw or multi-screw extruder or kneader. , A method of melting resin pellets and kneading with fibers, a method of kneading on a roller mill having a plurality of heating rollers, and the like.

The compression molded product of lignocellulose fibers produced by the production method of the present invention or the compression molded product of lignocellulose fibers of the present invention may be sold alone, or a fiber mixed cement material containing lignocellulose fibers and cement. May be sold as. Lignocellulosic fiber compression moldings or fiber-mixed cement materials are produced in factories, transported to local construction and civil engineering sites, where they are kneaded with mortar, other concrete materials and water. It is also preferable to use a fiber-reinforced cement material from the standpoint that a high-quality fiber-reinforced molded body can be produced while suppressing the conveyance cost.

In addition, from the viewpoint of easy delivery of fiber-mixed cement material to the construction and civil engineering sites and reduction in the cost of transporting fiber-mixed cement material, the fiber-mixed cement material has a moisture content of 15% by mass or less. The mortar mix or concrete mix is preferable, and the moisture content is more preferably 10% by mass or less. The mortar mix contains fine aggregates such as sand in addition to lignocellulose fibers and cement, and the concrete mix contains coarse aggregates such as gravel in addition to lignocellulose fibers and cement.
We produce lignocellulosic fiber compression moldings and fiber-mixed cement materials at factories, carry them to various construction and civil engineering sites, and knead them with mortar and other concrete materials and water. It is also preferable to use a fiber-reinforced cement material from the standpoint that a high-quality fiber-reinforced molded body can be produced while suppressing the conveyance cost.

In addition, from the viewpoint of easy delivery of fiber-mixed cement material to the construction and civil engineering sites and reduction in the cost of transporting fiber-mixed cement material, the fiber-mixed cement material has a moisture content of 15% by mass or less. The mortar mix or concrete mix is preferable, and the moisture content is more preferably 10% by mass or less. The mortar mix contains fine aggregates such as sand in addition to lignocellulose fibers and cement, and the concrete mix contains coarse aggregates such as gravel in addition to lignocellulose fibers and cement.

〔Additive〕
The lignocellulosic fiber according to the present invention includes preservatives, insecticides, fungicides, water repellents, ultraviolet absorbers, flame retardants, fillers, coupling agents, elastomers, antifoams as long as the effects of the present invention are not impaired. Various additives such as an agent, a lubricant, a pigment, a dye, an antifoaming agent, a water reducing agent, a swelling agent, and a shrinkage reducing agent can be added. These may be used individually by 1 type and may be used in combination of 2 or more type.
These additives can be appropriately blended at an arbitrary stage.

Further, the fiber reinforced composite material includes glass fibers, synthetic resin fibers, carbon fibers, cellulose nanofibers, lignocellulose nanofibers, cellulose nanocrystals, carbon nanotubes, other nanofibers and the like within a range not impairing the object of the present invention. Can be added. This is because, in general, it is empirically known that when a plurality of types of fibers having different characteristics and shapes are combined, a preferable effect can be obtained as compared with the case where any one of them is used alone.

When producing a fiber-reinforced cement material by mixing a compression molded body of lignocellulose fiber with cement and water, the compression molded body of lignocellulose fiber is mixed with cement and water in the presence of a dispersion aid. It is preferable to improve the uniform dispersibility of the lignocellulosic fibers and obtain a fiber-reinforced cement material excellent in strength and durability and a cured product thereof.
As the dispersion aid, nonionic surfactants are preferable. For example, glycerin fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyl diethanolamine, hydroxyalkyl monoethanolamine, polyoxyethylene alkylamine, polyoxyethylene alkylamine, Examples thereof include oxyethylene alkylamine fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and alkyldiethanol amides.
Polyoxyethylene sorbitan fatty acid esters are preferably mono-, di- or triesterized 1,4-, 1,5- or 3,6-sorbitan, ethylene oxide (EO), or ethylene oxide (EO) and propylene oxide. (PO) is obtained by addition condensation.

Examples of polyoxyethylene sorbitan fatty acid esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan dilaurate, polyoxyethylene sorbitan trilaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan dipalmitate, Polyoxyethylene sorbitan tripalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan distearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan diolate, polyoxyethylene sorbitan Triolate, polyoxyethylene sorbitan monoisostearate, polyoxyethylene sorbitan Isostearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan esters of mixed fatty acids, and the like. Examples of the polyoxyethylene sorbitan mixed fatty acid ester include sorbitan coconut oil fatty acid ester, monopalmitic acid polyoxyethylene sorbitan, and the like. As the polyoxyethylene sorbitan fatty acid esters, for example, polyoxyethylene sorbitan monolaurate is preferably used.
The nonionic surfactant mentioned above may be used individually by 1 type, and can also be used in combination of 2 or more type.

As described above, the preferred embodiments of the present invention have been shown and described, but each invention is not limited to the above-described embodiments, and can be appropriately changed.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.
1. Standard preparation method (Preparation of lignocellulose fiber)
The lignocellulosic fiber for fiberboard manufactured using the pressure type refiner in the fiberboard factory was used as lignocellulose fiber as it was. The fiber length was about 3 mm, and the fiber width was about 30 μm. Furthermore, using the same procedure, lignocellulose fibers for insulation boards (in particular, referred to as crude lignocellulose fibers) were produced and used as lignocellulose fibers as they were. The fiber length was approximately 15 mm and the fiber width was approximately 300 μm.
[Method for preparing cement material (water mixture)]
1 L of water was added to 2.5 kg of a commercially available lightweight mortar mix (manufactured by Fujikawa Construction Materials Co., Ltd., “AC mortar”) and stirred with a Hobart mixer to obtain a mortar cement material (water mixture).
Here, lignocellulosic fiber has high water absorption, so by adding lignocellulose fiber, apparent moisture is insufficient, kneading becomes difficult and water may be required. Water was added to the extent that the desired working efficiency could be ensured.

2. Bending toughness test (1) Cement material preparation method of Example and Comparative Example [Example 1]
A cement material was prepared according to the standard preparation method, except that instead of the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the following lignocellulose fiber A.
Lignocellulosic fiber A: Polyoxyethylene (20) sorbitan monolaurate, which is a nonionic surfactant having an antistatic effect, has an adhesion amount (in terms of solid content) of 1% by mass with respect to dry lignocellulose fiber. After the spray treatment as described above, the cement material reinforcing fiber was dried by a hot air dryer at 105 ° C.
[Example 2]
A cement material was prepared according to the standard preparation method, except that instead of the commercially available lightweight mortar mix, 2% by mass of the lightweight mortar mix was replaced with the following lignocellulose fiber B.
Lignocellulosic fiber B: Polyoxyethylene coconut alkylamine, which is a nonionic surfactant having an antistatic effect, is attached to lignocellulose fiber in a dry state (in terms of solid content) so as to be 2.5% by mass. After being sprayed on, the fiber for reinforcing cement material dried by a hot air dryer at 105 ° C.
Example 3
The cement material was adjusted according to the standard adjustment method, except that instead of the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the following crude lignocellulose fiber C.
Crude lignocellulosic fiber C: The amount of adhering polyoxyethylene (20) sorbitan monolaurate, which is a nonionic surfactant having an antistatic effect, to dry lignocellulose fiber (in terms of solid content) is 1% by mass. After the spray treatment as described above, the cement material reinforcing fiber was dried by a hot air dryer at 105 ° C.

[Comparative Example 1]
The above-mentioned commercially available lightweight mortar mix was used as it was, and a cement material (control) of Comparative Example 1 was prepared according to a standard preparation method.
[Comparative Example 2]
A cement material was prepared according to the standard preparation method, except that instead of the commercially available lightweight mortar mix, 0.5 wt% of the lightweight mortar mix was replaced with the following cellulose nanofiber.
Cellulose nanofiber: “Cellulose nanofiber (standard)” manufactured by Sugino Machine
In addition, since cellulose nanofiber has extremely high viscosity and cannot be kneaded when added more than this, the upper limit was made 0.5 mass%.
[Comparative Example 3]
In place of the above-mentioned commercially available lightweight mortar mix, a cement material was prepared according to the standard preparation method except that 0.75% by mass of the lightweight mortar mix was replaced with lignocellulose fibers not treated with an antistatic agent. Was prepared.
In the system to which no antistatic agent was added, it was observed during preparation that lignocellulosic fibers were clearly damped, so the upper limit was made 0.75% by weight.

(2) Evaluation of bending toughness test The cement materials prepared in Examples and Comparative Examples were subjected to a bending toughness test.
The bending toughness test is a method of calculating and evaluating the area under the load-displacement curve obtained when performing a bending test as the energy required for bending fracture. If the bending toughness is large, the evaluation becomes preferable.
(2-1) Test Method The prepared cement material was put into a mold and formed into a shape having a width of 75 mm, a length of 150 mm, and a thickness of 15 mm. After 24 hours, the mold was removed, and after curing at 20 ° C.-65% for 28 days, a bending toughness test was performed using the specimen. At the same time, the elongation of the material until the material required for destruction was also evaluated. All six test specimens were prepared, and the average was calculated for evaluation.
(2-2) Results Table 1 shows the test results. In addition, as for the result, the comparative example 1 (control) was set to 100, and the other result was represented by ratio (%) with respect to control.

From the above results, the bending toughness and the elongation at break were significantly improved with respect to Comparative Example 1 (control) in both Examples 1 and 2. In Example 3, the bending toughness was remarkably improved as compared with Comparative Example 1 (control). That is, it was clearly shown that the brittleness of the cement material is improved and the reinforcing effect is exhibited by adding lignocellulose fibers treated with an antistatic agent.
Comparative Example 3 is an example in the case of containing lignocellulose fibers but not containing an antistatic agent. Aggregation and lumps of lignocellulosic fibers that were clearly visible were observed in the prepared specimens. Moreover, it was clearly shown from the test results that the reinforcing effect was not effectively exhibited.

3. Ring test (1) Method for preparing cement materials of Examples and Comparative Examples [Example 4]
A cement material was prepared in the same manner as in Example 1.
Example 5
A cement material was prepared in the same manner as in Example 2.
[Comparative Example 4]
The above-mentioned commercially available lightweight mortar mix was used as it was, and a cement material of Comparative Example 4 was prepared according to a standard preparation method.

[Comparative Example 5]
A cement material was prepared in the same manner as in Comparative Example 2.
[Comparative Example 6]
A cement material was prepared in the same manner as in Comparative Example 3.
[Comparative Example 7]
The above-mentioned commercially available lightweight mortar mix was used as it was, and a cement material was prepared according to a standard preparation method. In the evaluation of the ring test described later, the evaluation was performed using a glass cloth made by knitting glass fibers on the surface of a ring-shaped test body. This reinforcement with glass cloth is a reinforcement method generally used in construction work in order to prevent cracking of concrete or mortar surface. The bending toughness test was not performed.

[Comparative Examples 8 to 12]
Instead of the above-mentioned commercially available lightweight mortar mix, a cement material was prepared according to the standard preparation method except that the 1, 2, 3, 4, 5% by mass replaced with the following lignocellulosic material cutting pieces A did.
Lignocellulosic material cutting pieces A: Particle board flakes (conifers) produced using a laboratory ring flaker were used as they were. The length of the cutting piece was about 10 mm, the width was 4 mm, and the thickness was 0.5 mm.
(2) Evaluation of ring test The cement materials prepared in Examples and Comparative Examples were subjected to a ring test.
The ring test is performed by pouring and molding the cement material into a ring-shaped test jig and utilizing the fact that the shrinkage stress generated by the hardening of the cement material differs between the inside and outside of the ring, and cracking occurs in the cement material. It is a method to evaluate.
(2-1) Test method The prepared cement material is put into a mold, and a test body is made in a ring-shaped mold having an inner circle of 50 mm, an outer circle of 150 mm, and a height of 50 mm. The bag was completely sealed and cured at 20 ° C. for 5 days. Thereafter, the bag and the outer circle were removed and placed in a dryer at 60 ° C. to evaluate the occurrence of cracks over time. Three test specimens were prepared and evaluated using the worst results.
(2-2) Results Table 2 shows the test results.

From the above results, Examples 4 and 5 showed a clear improvement effect as compared with Comparative Examples 4 to 7. In particular, no cracks were observed in Example 5, and cracks occurred in Example 4. However, the level of the cracks was slight and remained only on the surface in the thickness direction of the specimen. In Comparative Example 7, due to the reinforcing effect by the glass cloth, the occurrence of cracks was kept light in the width direction, but penetrated in the thickness direction.
Further, according to Comparative Examples 8 to 12, when a wood cutting piece is used alone, a large amount of addition is necessary, and problems such as cost, workability, and fluidity must be considered.

4). Combined use of lignocellulosic fibers and lignocellulosic material cutting pieces (1) Preparation method of cement materials of Examples and Comparative Examples [Example 11]
Instead of the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the above lignocellulose fiber A used in Example 1, and further 1% by mass was used in Comparative Examples 8-12. A cement material was prepared according to the standard preparation method described above except that the lignocellulosic material cutting piece A was used.
Example 12
Instead of using the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the above lignocellulose fiber A, and 2% by mass was replaced with the above lignocellulosic material cutting pieces A. Prepared a cement material according to the standard preparation method described above.
Example 13
Instead of using the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the above lignocellulose fiber A, and 3% by mass was replaced with the above lignocellulosic material cutting pieces A. Prepared cement material according to standard preparation methods.

[Comparative Example 21]
The above-mentioned commercially available lightweight mortar mix was used as it was, and a cement material (control) of Comparative Example 21 was prepared according to a standard preparation method.

Example 14
A cement material was prepared according to the standard preparation method, except that instead of the commercially available lightweight mortar mix, 1% by mass of the lightweight mortar mix was replaced with the lignocellulose fiber A described above.
Example 15
A cement material was prepared according to the standard preparation method, except that instead of the commercially available lightweight mortar mix, 2% by mass of the lightweight mortar mix was replaced with the lignocellulose fiber A described above.
[Comparative Examples 22 to 25]
Instead of the above-mentioned commercially available lightweight mortar mix, one in which 1% by mass, 2% by mass, 3% by mass or 4% by mass of the lightweight mortar mix is replaced with the above-mentioned lignocellulosic material cutting pieces A is used. Except for the above, a cement material was prepared according to a standard preparation method.
[Comparative Example 26]
As in Comparative Example 7 described above, the above-mentioned commercially available lightweight mortar mix is used as it is to prepare a cement material, and a glass cloth made by knitting glass fibers on the surface of the ring-shaped test body is used. I made something with it. In the ring test, the glass cloth reinforced was evaluated. The bending toughness test was not performed.

(2) With respect to Examples 11 to 15 and Comparative Examples 21 to 26, the bending toughness test and the ring test were performed by the above-described method, and the results of the similar evaluation are shown in Table 3. In addition, the result of the bending toughness test was set to 100 for Comparative Example 21 (control), and the other results were expressed as a ratio (%) to the control.

As is apparent from the results shown in Table 3, in Examples 11, 12, and 13, all the bending toughness and crack resistance were significantly improved with respect to Comparative Example 21 (control). In addition, Examples 11, 12, and 13 have improved bending toughness compared to Examples 14 and 15 in which only lignocellulose fibers treated with an antistatic agent were used alone.
Further, when the results at the same lignocellulose addition ratio were examined, Example 11 (1% by weight of lignocellulose fiber + 1% by weight of cutting piece of lignocellulose material = 2% by weight of content) was Comparative Example 23 (cutting lignocellulose material). Small piece 2% by weight = content 2% by weight), similarly, Example 12 (content 3% by weight) and Comparative Example 24 (content 3% by weight), Example 13 (content 4% by weight) and Comparative Example 25 (Content 4% by weight) can be compared.
Regarding the bending toughness test, Examples 11 to 13 are superior to Comparative Examples 23 to 25 each using a lignocellulosic material cutting piece alone, and the results of the ring test are also compared with Examples 11 to 13, respectively. Superior to Examples 23-25. Further, the result was superior to the reinforcing effect of the glass cloth of Comparative Example 26.
From the above, it can be seen that by using the lignocellulosic material cutting pieces together with the lignocellulose fibers, it is possible to obtain an excellent effect that is difficult to achieve conventionally. The lignocellulose fibers and the lignocellulose material cutting pieces are both made from lignocellulose material, and the lignocellulose material alone is also excellent in that such excellent effects can be obtained.

4). In-plane shear test (1) Preparation method of cement materials of Examples and Comparative Examples [Example 16]
A cement material was prepared in the same manner as in Example 12.
[Comparative Example 27]
The above-mentioned commercially available lightweight mortar mix was used as it was, and a cement material (control) of Comparative Example 27 was prepared according to a standard preparation method.

(2) Evaluation of in-plane shear test The cement materials prepared in Example 16 and Comparative Example 27 were subjected to an in-plane shear test.
The in-plane shear test is a method for evaluating the crack resistance of a specimen by measuring the total length of cracks generated when a load is applied in the horizontal direction to the upper part of a wall-like specimen.
This in-plane shear test conforms to the in-plane shear test (B) (when tie rods are not used) of JIS A 1414 “Performance test method for building components (panels) and structural parts thereof”. .

(2-1) Test Method FIG. 1 shows a schematic diagram of the in-plane shear tester 1 used in the in-plane shear test. A rectangular frame 20 composed of a base 21, a pair of

columns

22, 22 and a beam 23 is formed using a 105 mm square wooden square, and a 18 mm thick small plate (not shown) is formed on one side of the frame 20. ) Was fixed, and a lath net (not shown) was fixed thereon. The frame body 20 has its base 21 fastened to the force frame 11 of the in-plane shear tester 1 using hexagon bolts (M12), and the column base of the column 22 is fixed to the base 21 using hole-down hardware. .
In this way, a rectangular test wall 2A having a length of 1400 mm and a width of 1450 mm was formed. The cement material prepared in Example 16 and Comparative Example 27 was applied to the surface of a lath net (not shown) of the test wall 2A so as to have a thickness of 18 mm, and cured for one month or longer. It was created. As the test body 3, the window frame was arrange | positioned in the center part, and the mortar wall which has the opening part 26 for windows in the center part was formed.
A load was applied to the beam 23 of the frame body 20 in the horizontal direction (X, Y direction) by the force jack 12, and the frame body 20 and the test body 3 were subjected to shear deformation to the deformation angles shown in Table 4. For each deformation angle, a load was applied three times in the positive direction (X direction) and the negative direction (Y direction), and then the total length of cracks generated in the specimen 3 was measured.
(2-2) Test results Table 4 shows the test results. Table 4 shows the crack appearance status of the specimen 3. As a result, for each of Example 16 and Comparative Example 27, the total length of cracks generated around the window frame was measured, and the ratio of the total crack length of Example 16 to the total crack length of Comparative Example 27 (% )

From the above results, it was found that Example 16 had a remarkable crack suppression effect because the total length of cracks when shear deformation was applied was shorter than that of Comparative Example 27. That is, it was clearly shown that the brittleness of the cement material was improved by adding the lignocellulosic material cutting pieces together with the lignocellulosic fiber to the cement material, and high crack resistance against external force was exhibited.

[Second fiber for cement material reinforcement]
1. Preparation of lignocellulosic fiber The lignocellulose fiber for fiberboard manufactured using the pressure type refiner in the fiberboard factory was used as lignocellulose fiber as it was. The fiber length was about 3 mm, and the fiber width was about 30 μm.

1. Preparation of fiber for reinforcing cement material [Example 31]
With respect to the dried lignocellulose fiber obtained as described above, the amount of the polyacrylamide resin (Arakawa Chemical Industries, Ltd .: Polystron 705) attached to the dried lignocellulose fiber (in terms of solid content) is 1 mass. After being appropriately diluted with water and sprayed so as to be%, drying and thermosetting treatment were performed in an oven at 105 ° C. for 10 minutes. Moreover, in the sprayed liquid, polyoxyethylene (20) sorbitan monolaurate is blended as an antistatic agent, and the amount of the antistatic agent attached to dry lignocellulose fibers (in terms of solid content) is 1 mass. It was made to adhere so that it might become%. In this way, a cement material reinforcing fiber of Example 31 was obtained.
[Example 32]
With respect to the dried lignocellulose fiber obtained as described above, a melamine / urea / formaldehyde resin (molar ratio 1.15, melamine content 1% by mass) is attached to the dried lignocellulose fiber (in terms of solid content). ) Was appropriately diluted with water so as to be 10% by mass and sprayed, followed by drying and thermosetting treatment in an oven at 105 ° C. for 5 minutes. Moreover, in the sprayed liquid, polyoxyethylene (20) sorbitan monolaurate is blended as an antistatic agent, and the amount of the antistatic agent attached to dry lignocellulose fibers (in terms of solid content) is 1 mass. It was made to adhere so that it might become%. Thus, the cement material reinforcing fiber of Example 32 was obtained.

Example 33
With respect to the dry lignocellulose fiber obtained as described above, an aqueous dispersion of cellulose nanofiber (“Binfiss” manufactured by Sugino Machine Co., Ltd.) is attached to the dry lignocellulose fiber in an amount of 1 mass (solid content conversion). % Was appropriately diluted with water and sprayed, and then dried in an oven at 105 ° C. for 10 minutes. Moreover, in the sprayed liquid, polyoxyethylene (20) sorbitan monolaurate is blended as an antistatic agent, and the amount of the antistatic agent attached to dry lignocellulose fibers (in terms of solid content) is 1 mass. It was made to adhere so that it might become%. Thus, a cement material reinforcing fiber of Example 33 was obtained.
Example 34
With respect to the dry lignocellulose fiber obtained as described above, an aqueous dispersion of lignocellulose nanofibers is appropriately water so that the amount of adhesion (in terms of solid content) to the dry lignocellulose fiber is 1% by mass. After diluting with and spraying, it was dried in an oven at 105 ° C. for 10 minutes. Moreover, in the sprayed liquid, polyoxyethylene (20) sorbitan monolaurate is blended as an antistatic agent, and the amount of the antistatic agent attached to dry lignocellulose fibers (in terms of solid content) is 1 mass. It was made to adhere so that it might become%. Thus, the cement material reinforcing fiber of Example 34 was obtained.

[Comparative Example 31]
The dried lignocellulose fibers obtained as described above were used without being treated with a resin. However, in order to ensure dispersibility, polyoxyethylene (20) sorbitan monolaurate is applied as an antistatic agent so that the amount of adhesion (in terms of solid content) to dry lignocellulose fibers is 1% by mass. I let you. Thus, the cement material reinforcing fiber of Comparative Example 31 was obtained.

3. Preparation of cement material (water mixture) Commercial lightweight mortar mix (Fujikawa Construction Materials Co., Ltd., "AC mortar") Add 1L of water to 2.5kg mass and stir with a Hobart mixer to obtain mortar cement material (water mixture) Got. This preparation method is a standard preparation method. For the fibers for reinforcing the cement material of Examples 31 to 34 and Comparative Example 31, 1% by mass of the light-weight mortar mix is used for Examples 31 to 34 or Comparative Example 32. A fiber reinforced cement material was obtained according to the standard preparation method except that the fiber was replaced with a cement material reinforcing fiber.
Here, lignocellulosic fiber has high water absorption, so by adding lignocellulose fiber, apparent moisture is insufficient, kneading becomes difficult and water may be required. Water was added to the extent that the desired working efficiency could be ensured.

4). Evaluation of Bending Toughness Test Each cement material prepared using the fiber reinforced cement material of Examples 31 to 34 or Comparative Example 32 was subjected to a bending toughness test. Further, as Comparative Example 31, a cement material prepared by the standard preparation method using the above-described commercially available lightweight mortar mix as it was was also subjected to a bending toughness test.
The bending toughness test is a method of calculating and evaluating the area under the load-displacement curve obtained when performing a bending test as the energy required for bending fracture. If the bending toughness is large, the evaluation becomes preferable.
4-1. Test Method The prepared cement material was put into a mold and formed into a shape having a width of 75 mm, a length of 150 mm, and a thickness of 15 mm. After 24 hours, the mold was removed, and after curing at 20 ° C.-65% for 28 days, a bending toughness test was performed using the specimen.
In addition, as accelerated deterioration treatment, 8 hours of immersion in 20 ° C. water and 16 hours of drying in a dryer at 60 ° C. are defined as 1 cycle, and after repeating 0 cycle and 10 cycles, a bending toughness test is performed. The initial strength and the long-term durability of the strength were evaluated. All six test specimens were prepared, and the average was calculated for evaluation.
4-2. Results Table 5 shows the test results. In addition, the test result set the comparative example 31 (control) to 100, and represented the other result by ratio (%) with respect to the value of the comparative example 31 (control).

From the results shown in Table 5, both Examples 31 and 32 showed an effect of maintaining the bending toughness after the accelerated deterioration treatment with respect to Comparative Examples 31 and 32. That is, by blending the cement material reinforcing fiber of the present invention consisting of lignocellulosic fiber with a resin as a fiber surface coating agent attached to the cement material, the brittleness of the cement material is improved more than before, and for a longer period of time. It was clarified that the reinforcing effect was exhibited across.
Further, from the results shown in Table 5, in Example 33, the bending toughness was remarkably improved and the sustaining effect was excellent as compared with Comparative Examples 31 and 32. Also in Example 34, the effect of improving the bending toughness was recognized. That is, as a fiber surface coating agent, the cellulose nanofiber is treated with the fiber for reinforcing a cement material of the present invention, particularly cellulose nanofiber and / or lignocellulose nanofiber, which is composed of lignocellulose fiber to which (ligno) cellulose nanofiber is attached. Addition of lignocellulosic fibers obtained by drying and hardening lignocellulose nanofibers to the cement material improves the brittleness of the cement material more than before, and at the same time exerts a reinforcing effect for a longer period of time. It was revealed. In Example 34, 10 cycles of measurement were not performed. However, as in Example 33, it is presumed that the effect of improving the bending toughness is excellent.
Further, from the results shown in Table 5, according to the fiber-mixed cement material of the present invention using the fiber for reinforcing cement material of the present invention and the fiber-reinforced cement material of the present invention, a fiber-reinforced molded article excellent in water resistance and durability. It can also be seen that can be formed.

[Examples of compression molded product of lignocellulose fiber]
1. Manufacture of compression molded body of lignocellulose fiber The diameter of the discharge nozzle (discharge hole) of the die plate part (die) of the biaxial volume reduction solidification device (DP-3S) manufactured by Oguma Steel Corporation is 20 mm or 11 mm, and the fiber Lignocellulose fiber (13% moisture content) manufactured from fiberboard wood manufactured at a board factory is used as a raw material, and it is put into the device alone from the raw material input section, and the lignocellulose fiber pellets (compression molded product). Manufactured.
As a result, a compression molded product of lignocellulose fibers having a bulk density of 420 to 440 kg / m ³ could be obtained from lignocellulose fibers having a bulk density of 40 kg / m ³ .

2. Evaluation of Lignocellulose Fiber Compression Molded Body (1) Application to Fiber Reinforced Cement Composite Material Add 2% by mass of 20mm diameter lignocellulosic fiber pellets to a commercially available lightweight mortar mix, and use polyoxyethylene as a dispersion aid. (20) Water was added to 1% by mass of sorbitan monolaurate based on the pellets, and the mixture was stirred for 2 minutes using a Hobart mixer. As a result, it was possible to obtain a slurry mix in which lignocellulose fibers were uniformly dispersed in the mortar / water slurry without forming lumps.
(2) Application to fiber-reinforced resin composite material Lignocellulose fiber pellets having a diameter of about 11 mm and a length of about 5 mm together with resin pellets are placed in a biaxial kneading-type extruder for resin compound production set at 180 ° C. The disintegration / dispersion of the cellulose fiber pellet was evaluated. As a result, the lignocellulose fiber pellets were easily disintegrated and dispersed in a biaxial kneading apparatus, and a resin compound containing lignocellulose fibers was obtained without problems.

From the above results, it has been shown that normally bulky lignocellulose fibers can be compressed to 10 to 11 times without adding an external binder. From this, it can be said that lignocellulosic fibers can be transported, stored and handled economically and efficiently.
Furthermore, when the lignocellulose fiber compressed pellets were mixed with mortar mix and resin pellets, in any case, they could be uniformly dispersed in the dispersion without causing lumps. This confirms that lignocellulosic fibers can be suitably dispersed in different types of dispersions (dispersion medium: for example, water in the case of cement-based materials and molten liquid resin in the case of resin-based materials). It can be said that it can be used for various purposes as a reinforcing fiber for a fiber-reinforced composite material.

The fiber for reinforcing cement material of the present invention uses plant-derived lignocellulosic fibers, which is preferable from the viewpoint of consideration for the environment and can effectively reinforce the cement material.
According to the fiber-mixed cement material of the present invention, a high-performance fiber-reinforced molded body reinforced with plant-derived lignocellulose fibers can be produced.
According to the method for producing a fiber-reinforced cement material of the present invention, a fiber-reinforced cement material capable of forming a high-performance fiber-reinforced molded body reinforced with plant-derived lignocellulose fibers can be efficiently produced.
According to the fiber-reinforced cement structure and the method for producing a fiber-reinforced cement structure of the present invention, it is possible to easily obtain a high-strength fiber-reinforced cement structure in which the brittleness of the cement material is improved.

The fiber for reinforcing a cement material according to the present invention uses lignocellulosic fiber derived from a plant, which is preferable from the viewpoint of consideration for the environment, and can effectively reinforce the cement material, and also has a sustained reinforcing effect. Are better.
Moreover, according to the fiber-mixed cement material of the present invention, it is possible to produce a fiber-reinforced molded body that is reinforced with plant-derived lignocellulose fibers and has excellent water resistance and durability.
In addition, according to the method for producing a fiber-reinforced cement material of the present invention, a fiber-reinforced cement material that is reinforced with plant-derived lignocellulosic fibers and can form a fiber-reinforced molded article having excellent water resistance and durability is efficiently produced. Is possible.

More specifically, according to the present invention, one or more of the following effects can be achieved.
(1) A cement composite material having excellent physical properties can be obtained, and carbon neutral emission can be suppressed by using carbon neutral lignocellulosic fiber. As a result, during the period when the cement material is used, It becomes possible to stock carbon dioxide.
(2) The fiber reinforced cement material obtained by the present invention has improved brittleness, is resistant to drying shrinkage and tensile stress, and is excellent in impact absorption. As a result, long-term durability can be exhibited, the life cycle of the cement material can be extended, and the effect is great both economically and environmentally.
(3) Since it is easily biodegraded in the environment, its influence on the environment is reduced after its manufacture, use and use. In addition, the explosion of cement material during a fire is reduced.

According to the method for producing a compression-molded body of lignocellulose fiber of the present invention, the lignocellulose fiber is efficiently compressed and molded without substantially using a binder added from the outside, and the compression molding of the lignocellulose fiber is performed. You can get a body. Moreover, the compression molded body of the lignocellulose fiber manufactured can be transported, stored and handled efficiently and economically because the lignocellulose fiber is compressed as an aggregate. In addition, since it is compressed and molded without excessive fiber breakage, when used in a fiber-reinforced composite material, it exhibits an excellent reinforcing effect of the material to be reinforced, and a high-performance fiber-reinforced composite material or The cured product can be obtained.

Moreover, by providing a cutting mechanism on the downstream side of the die, the cut length in the length direction of the compression molded body can be adjusted as desired when discharging from the discharge hole, and can be made into a short cylindrical shape. It is also possible. By making the lignocellulosic fiber into a compression-molded body, in particular by adjusting the size to a desired length and adjusting the size, the meterability, feedability, and uniform mixing with other materials are improved. It will be easier to deploy to various applications.

In addition, according to the method for producing a fiber-reinforced composite material of the present invention, a fiber-reinforced composite material (for example, a material that can be efficiently blended with a material to be reinforced and whose physical properties such as strength and durability are greatly improved (for example, , Cement, asphalt and resin composite materials). The fiber-reinforced composite material includes both the composition before curing and the cured product after curing.
In the cured body of the fiber-reinforced composite material of the present invention, the material to be reinforced is reinforced with lignocellulosic fibers derived from plants such as wood or non-wood, and is excellent in strength and durability.

Claims

Cement material reinforcing fiber, characterized by comprising lignocellulose fiber with antistatic agent attached.
Furthermore, the fiber for cement material reinforcement of Claim 1 to which the 1 or more types of fiber surface coating agent selected from the group which consists of resin, a cellulose nanofiber, and a lignocellulose nanofiber has adhered.
A cement material comprising a lignocellulose fiber to which a fiber surface coating agent is adhered, wherein the fiber surface coating agent is at least one selected from the group consisting of a resin, a cellulose nanofiber, and a lignocellulose nanofiber. Reinforcing fiber.
The cement material reinforcing fiber according to claim 2 or 3, wherein the fiber surface coating agent is at least one resin selected from the group consisting of amino resins, polyacrylamide resins, and polyacrylamide resin derivatives.
The cement material reinforcing fiber according to claim 1 or 2, wherein the antistatic agent is not cationic.
The cement material reinforcing fiber according to claim 1, 2 or 5, wherein the antistatic agent is aqueous.
The cement material reinforcing fiber according to any one of claims 1, 2, 5, and 6, wherein the antistatic agent is a polyoxyethylene sorbitan fatty acid ester.
A fiber-mixed cement material comprising the cement material reinforcing fiber according to any one of claims 1 to 7 and cement.
The fiber-mixed cement material according to claim 8, wherein the fiber-mixed cement material is a mortar mix or a concrete mix having a moisture content of 15% or less.
The fiber-mixed cement material according to claim 8 or 9, further comprising a small piece obtained by cutting a lignocellulose material.
A method for producing a fiber-reinforced cement material, wherein the fiber for reinforcing a cement material according to any one of claims 1 to 7 is mixed with cement and water.
Furthermore, the manufacturing method of the fiber mixing cement material of Claim 11 characterized by adding the small piece which cut the lignocellulose material.
A method for producing a compression-molded body of lignocellulose fibers used in a fiber-reinforced composite material,
The lignocellulose fiber or the fiber for reinforcing a cement material according to any one of claims 1 to 7 is introduced into a multi-screw extruder having two or more screws, and the lignocellulose fiber Compression molding of lignocellulosic fibers, wherein the blades are forcibly transferred and compressed toward a die by screw blades meshing with each other, and the compressed product is discharged from a plurality of discharge holes provided in the die. Body manufacturing method.
14. The method for producing a compression-molded body of lignocellulose fibers according to claim 13, wherein the bulk density of the compression-molded body of lignocellulose fibers to be produced is 100 to 800 kg / m 3 .
The method for producing a compression-molded body of lignocellulose fibers according to claim 13 or 14, wherein the fiber-reinforced composite material is a fiber-reinforced cement material.
A fiber-reinforced cement material, which is reinforced by using a compression-molded body of lignocellulose fibers produced by the method according to claim 15.
The fiber-mixed cement material according to claim 16, further comprising mixing small pieces cut from the lignocellulosic material.
A fiber-reinforced cement structure comprising a fiber for reinforcing a cement material according to any one of claims 1 to 7, or a compression molded product of lignocellulosic fiber produced by the method according to claim 15. body.
The fiber-reinforced cement structure according to claim 18, further comprising a small piece obtained by cutting a lignocellulosic material.