JP2022117650A - Method for collecting immature wood part of tree, wood powder particle suspension and its production method, and method for producing coating film using wood powder particle suspension - Google Patents

Abstract

To provide a method for collecting immature wood parts of trees and a method for producing a wood powder particle suspension by mixing cellulose nanofibers with lignin or hemicellulose separated from wood powder.SOLUTION: A wet milling method of the invention facilitates the conventional very labor-intensive processes of micronization and nanofiberization by using immature wood parts that are easy to grind as raw materials and by performing fine grinding and classification processes. A wood powder particle suspension of the invention suitable for forming a coating film is produced by mixing the wood powder having a nanofiberized surface with cellulose nanofibers and lignin or hemicellulose separated from the wood powder in the suspension, and the average particle size of the wood powder in the suspension is 50 μm or less, and the concentration of the cellulose nanofiber contained in the suspension is 50% or less of the wood powder by weight. The coating film produced from the liquid has excellent adhesion to the base material and has excellent heat insulating properties and design properties that are characteristic of wood.SELECTED DRAWING: Figure 7

Description

Application for application of Article 30, Paragraph 2 of the Patent Law (1) Toyama Prefectural Industrial Technology Research and Development Center Research Report No. 34 2020 p. 3-4 (Publication date: July 20, 2020 Publisher: Toyama Prefectural Industrial Technology Research and Development Center)

The present invention provides a method for collecting immature wood from a tree, a wood flour particle suspension in which cellulose nanofibers separated from wood flour, lignin and hemicellulose are mixed in the suspension, and a method for producing the same. and a method for producing a coating film using a wood flour particle suspension.

Cellulose nanofibers (CNF) have attracted attention as next-generation environmentally friendly materials, and various applications have been attempted as gels or additives that impose thixotropic properties, or as reinforcing agents due to their high strength. However, there are still issues such as manufacturing costs, such as the high cost of mixing CNF, which is hydrophilic (easy to mix with water), with hydrophobic plastic (hard to mix with water).
In addition, in research on the production of cedar wood powder, a part of wood powder such as cedar is made into lignocellulose nanofiber (LCNF) consisting of lignin and cellulose nanofiber, so that it has the characteristics of CNF and lignin. It is being studied to give the film a feature of the wood-derived structure. It has been reported that when this wood powder is used as a raw material to produce a compound for kneading WPC under appropriate conditions, the wood flour can be made into fine fibers of the order of pigments (10 µm or less). has been developed.

In Non-Patent Document 1, as a basis for nanofiber production, it was thought that "as a method for effectively nanoizing the woody tissue, the beating treatment performed in the paper pulp field was considered effective. The beating process involves immersing pulp raw materials in water and mechanically applying shear force and pressure to make thick pulp fibers into finer fibers and to fluff some of the surfaces (internal and external). fibrillation), a method of increasing the amount of entanglement of fibers and hydrogen bonding between fibers to improve the strength of paper.In the laboratory beating process, wood flour and pulp are mixed at a solid content concentration of about 5 wt%. After being dispersed in water, it can be prepared by wet pulverization using a ball mill.In such a simple wet pulverization process, no purification etc. When defibrated, the ultrafine fibers obtained are LCNF containing lignin and hemicellulose."
In addition, as an efficient nanofiber production from wood, ``In the previous section, LCNF production by wet ball milling was described, but ball milling is a high-cost process that is difficult to perform in large quantities and continuously. As a result of examining the wet grinding method, it was found that an electric millstone type (grinder) disk type grinder (Super Mascolloider, Masuko Sangyo Co., Ltd.) was effective (solid content concentration is about 5 wt%). As the test progressed, the nano defibration efficiency varied greatly depending on the tree species used as the raw material, and in the disk mill, which has a lower shear force than the ball mill, the efficiency was greatly reduced for hard wood such as broad-leaved trees. We also considered optimizing (clearance between discs, number of rotations, etc.), but as a more reliable method, we investigated an efficient process by weakening the wood structure that is the raw material in advance.Results , It was found that the wood structure can be weakened by combining preliminary coarse pulverization and hydrothermal treatment....As preliminary pulverization, wet high-speed cutter mill (Micro Meister, Masuko Sangyo Co., Ltd.) and dry type can be used. The effect was shown by miniaturization (about 1 mm to 100 μm) by cutter mill pulverization, etc. Hydrothermal treatment involves partial hydrolysis of wood components with pressurized hot water at 100 ° C or higher using a special pressure vessel. As mentioned above, the factor that strengthens the woody tissue is the adhesive action of the laminated cell wall structure and hemicellulose, etc. In the above preliminary pulverization treatment, a strong tissue structure (hoop-like structure) is formed. Hydrothermal treatment partially hydrolyzes the hemicellulose, weakening the adhesive action, these processes partially destroy or degrade wood toughening factors, and greatly weaken the wood structure. As a final step, disc milling can efficiently and effectively loosen the woody tissue and produce nanofibers.”

Here, in Non-Patent Document 2, the results of measuring the Young's modulus of Bokasugi, etc. are shown under the title of "Elucidation of the strength distribution in the trunk of large-diameter Bokasugi wood." 2 to 4 in Non-Patent Document 2 are shown in FIG.
In Non-Patent Document 2, "1 Background In the cedar plantations in the prefecture, the lengthening of the cutting period is progressing. Large-diameter timber with a mouth diameter of 30 cm or more is expected to be produced (Fig. 1). So far, we have not fully understood the material properties of a large-diameter Bokasugi tree, so we measured the density and tracheid length, which are indicators of the material, and the Young's modulus, which is an indicator of strength. We examined the distribution within the tree trunk.”
In addition, ``2 Overview of research results 1) Distribution of materials in the trunk From a 62-year-old Bokasugi (tree height: 32.9m, breast height diameter: 52cm), discs were cut every 4m, and the density, annual ring width, and tracheid length (TL) were cut out. ), the microfibril inclination (MFA) was measured.In general, within the trunk, the immature wood part around the pith is flexible and weak, and the mature wood part around it is firm and strong. The immature zone was calculated from the tendencies of the tracheid tube length and the microfibril inclination.Furthermore, when practical judgment indices were examined, the immature zone roughly coincided with the annual ring width of 6 mm (Figs. 2 and 3). ).This annual ring width 6 mm boundary is adopted by the Japanese Agricultural Standards (JAS) for lumber, and can be said to be an index that is easy for lumber mills to use.The density tended to increase as the height of the tree was higher. In the radial direction (horizontal direction), although it was slightly lower at around 50 mm from the pith, a generally constant trend was observed (Fig. 4).

In addition, in Non-Patent Document 3, the concept of basic words is explained under the title of "Understanding of heartwood/sapwood, core wood, and immature wood". Below is an excerpt from the summary (Table 1).

Production of lignocellulose nanofiber and resin composite technology https://www.jstage.jst.go.jp/article/jjsk/81/0/81_23/_pdf/-char/ja Clarification of strength distribution in trunk of large-diameter Bokasugi taffrc.pref.toyama.jp/nsgc/center/webfile/t1_98327e479120dfec4d4745c3bd8e0cc2.pdf Understanding heartwood, sapwood, core wood, and immature wood https://kinomemocho.com/zatu_shinzai_shinmochizai.html

The inventors of the present application have found that by using lignocellulose nanofibers (LCNF) as part of wood flour, it is possible to impart the characteristics of lignin, which has amphiphilic properties with CNF, and when it is made into a film, wood We thought that it would be possible to provide excellent heat insulation and adhesion (adhesiveness) due to the powder-derived structure. Its applications include heat-resistant paints and high-class handicraft products that make the most of its texture. In addition, CNF can add strong bonds between wood flour particles by strong hydrogen bonds, and research and development was conducted on this.
As a result of the experiment, depending on the tree species used as the raw material, the fibrillation efficiency into nanofibers differs, and the properties of the wood flour produced differ depending on the part of the wood and the moisture content. In addition, when conventional wood powder containing no nanofibers was used as a paint, finely pulverized wood powder agglomerated and precipitated in the paint, making it difficult to make a paint (Fig. 10). In other words, even if it is dispersed at first, the wood powder aggregates and precipitates over time, and it is difficult to make a paint that forms a uniform coating film by firmly bonding the wood powder together. Met. In addition, depending on the tree species used as a raw material, there was also a problem that a device with high shearing force was required (Non-Patent Document 1). Furthermore, when this wood powder is used as a raw material for paint, a large amount of polypropylene resin or the like is required as a binder, and it has been difficult to make a paint by only processing while adding water. In addition, depending on the temperature conditions, it was not possible to maintain excellent heat insulation or to produce a thin film (coating film) with excellent adhesion (adherence) (Non-Patent Document 1). That is, in order to produce cellulose nanofibers, the mechanical treatment must be performed as many times as several tens of times, resulting in poor productivity. In addition, if the treatment is carried out more than necessary, the film shrinks significantly during the drying process, resulting in cracking problems and poor adhesion to the substrate, making it impossible to form a good coating film.

Here, as a raw material for the wood powder particle suspension suitable for coating materials, etc., it is possible to collect from wood in general, and it is possible to process it by a wet pulverization method. In the above, if the stump retains a certain amount of moisture, even if it is a stump that has been cut down, if it has roots, the amount of moisture is ensured by the circulation of water, so it is more preferable. has been clarified by the inventors of the present application through research.
However, it is difficult to distinguish the immature part of the tree from the heartwood of the tree. In addition, it is necessary to retain a certain amount of moisture. There is a risk that a raw material that is not suitable as a raw material for the turbid liquid will be collected.

Accordingly, an object of the present invention is to provide a method for extracting the raw material (a method for extracting the immature wood portion of a tree) in which the immature wood portion of the tree is suitable as a raw material for the wood powder particle suspension. The purpose is to In addition, the object of the present invention is to provide a paint that is a thin film (coating film) with excellent adhesion (adhesiveness) and has excellent heat insulation (thermal conductivity), and a wood powder coating film that can be formed by just processing while adding water. The object of the present invention is to provide a wood powder particle suspension, a method for producing the same, and a method for producing a coating film.

The inventors of the present application have found that conifers such as cedar and cypress and broadleaf trees such as Mizunara can be used as raw materials to easily convert cellulose nanofibers (CNF). It was found that a film having excellent adhesion (adherence), heat insulation (thermal conductivity), and design (film formation) can be formed by structure. In tropical rainforests, organic matter in the soil is quickly decomposed into inorganic matter due to the high temperature and humidity.
The film (coating film) is applied to paints for heat countermeasures that have excellent heat insulating properties and excellent film-forming properties due to the structure derived from wood, and to high-class handicrafts that make use of the texture. can be considered. Furthermore, by including CNF, it was possible to produce a film (coating film) that exhibits properties superior to bulk wood, such as hardness.
The present invention is a method for collecting immature wood from conifers such as Japanese cedar and Japanese cypress or from broadleaf trees such as Quercus crispula. Judging the annual rings of the tree with the remaining roots, coating agents (including exterior wall coating agents, floor coating agents, or these surface treatment agents), pigments, adsorbents, anti-mold agents, etc. A method for extracting immature wood from a tree, characterized by extracting a raw material for a wood powder particle suspension by cutting. In addition, the portion of immature wood has a height position of 2 m to 3 m from the ground, and when the tree is about 20 to 30 years old, it is a portion within 15 years old from the center of the wood. The method for collecting immature wood portions of trees according to claim 1, characterized in that:
Here, in Japanese cedar, the heartwood has a very large number of grain sizes of several μm, and the heartwood at the root of cedar and the like has immature (soft) cells (contains a large amount of immature wood). It was found that this part has different easiness of forming fine fibers depending on the part of the cedar, etc., has a characteristic of low thermal conductivity, and has a hygroscopic function. These parts can be easily sorted out by classifying and classifying the wood. In addition, depending on the type of wood, heartwood and immature wood can be sorted by their color tone, odor, annual rings, etc. (in order to ascertain the above functions, it is more preferable to judge by annual rings). Then, from the material collected from the immature wood portion of the tree according to claim 1 or 2, a coating agent (including an exterior wall coating agent, a floor coating agent, or a surface treatment agent thereof), a pigment, an adsorbent, Suspension raw materials such as antifungal (mold) agents are adjusted only by adjusting the moisture content (the amount of wood flour is 1 to 20% by weight relative to water) by a wet pulverization method, and coating agents (exterior wall coating agents, It is possible to produce a wood flour particle suspension suitable for suspensions of floor coating agents, or these surface treatment agents), pigments, adsorbents, anti-mold (mold) agents, and the like.
In addition, the present invention provides a suspension of wood flour particles containing cellulose nanofibers, which is processed by a wet grinding method (under conditions where the weight percentage of water is larger than that of wood flour) after dry grinding of wood with an impact grinder or the like. In the liquid, wood flour with a nanofiber surface and wood flour particle suspension in which cellulose nanofiber separated from wood flour, lignin and hemicellulose are mixed in the suspension. A suspension of wood flour particles characterized by having a particle diameter of 50 μm or less and a concentration of cellulose nanofibers contained in the suspension being 50% or less of wood flour by weight. In addition, the present invention provides wood powder particles containing cellulose nanofibers, which are processed by dry pulverizing wood with an impact pulverizer or the like and then wet pulverizing (under conditions where the weight percentage of water is higher than that of wood flour). In the suspension, wood cut as a raw material is naturally dried indoors, then finely pulverized and classified to obtain wood flour with a nanofiber surface and cellulose nanoparticles separated from the wood flour in the suspension. A wood flour particle suspension in which fiber and lignin or hemicellulose are mixed, wherein the average particle size of the wood flour is 50 μm or less, and the concentration of cellulose nanofibers contained in the suspension is the weight ratio of the wood flour is 50% or less of the wood flour particle suspension. In this case, the compounding ratio is preferably 80 to 99% by weight of water and 1 to 20% by weight of wood flour (wood powder).
According to the present invention, when coniferous trees such as cedar are pulverized by a fine particle grinder, a part of the surface is converted into nanofibers, and a coating composition that can be made into a coating with only water and can form a strong woody film is obtained. . It is highly safe because the raw materials are only wood powder from wood such as cedar and water. This material has good water absorption, oil absorption, and adsorption properties, and is excellent in wettability with water, so it can be used in various applications by mixing it with other materials. Only the surface (surface layer, front and back) can be efficiently atomized by atomizing with a grinder-type grinder (electric stone mill-type disk-type grinder) composed of a grindstone. Then, the wood flour containing lignin and hemicellulose can be wet ground to obtain lignocellulose nanofibers. In addition, in order to grind (and fluff) to an average particle size of 50 μm or less, the raw material may be immersed in water for beating treatment, but from the viewpoint of production efficiency, the stone mill It is preferable to use a type grinder (electric stone mill type disk type grinder).
Coniferous trees such as Japanese cedar and Japanese cypress and broadleaf trees such as Mizunara oak are more preferably immature rooted portions remaining after cutting at a height of about 2 to 3 m from the ground. That is, it may be a portion with a height of 2 m to 3 m or less from the ground before being felled, but it may be a portion with roots left on a mountain after being felled. Rather, it is easier to recognize that it is an immature part (it is easier to judge from the annual rings, etc.) in the part with roots after it has been cut down, and not only is it easier to extract it, but it is also rooted. The immature cells formed at the time of young trees are alive as they are, unlike the parts that are felled and do not absorb water from the roots, even if they are felled and left in the forest. It is relatively fragile and can be easily pulverized into fine fibers by wet pulverization (suitable as a material for wood powder paints). Regardless of the age of the tree, there is no change over time. Even Jindai cedar that has been in the ground for thousands of years can be turned into paint (if it has roots, there is a supply of water, and as long as the wood fibers are not decomposed by fungi, etc. immature parts may be used). If it is the remains of felling in a rooted state, it can be said that the original immature state is rather maintained in the state from when the tree was young. It is suitable for application to a coating film manufacturing method using a particle suspension. These parts are the parts that are usually discarded in lumber, etc. (Non-Patent Document 2), or the parts that are left unattended when they are cut in the forest, but the rest of the felling can be used ( It can be said that the immature part is preserved in an ideal form.), which is expected to lead to the discovery of environmentally friendly raw materials.

In addition, in the method for producing a coating film of the present invention, wood cut out as a raw material is naturally dried indoors, then finely pulverized and classified, and then wood flour having a nanofiber surface and a suspension A wood flour particle suspension is prepared in which cellulose nanofibers separated from wood flour, lignin and hemicellulose are mixed therein, and the average particle size of the wood flour is 50 μm or less, and the cellulose nanofibers contained are A coating film is formed by using a wood flour particle suspension having a concentration of 50% or less of wood flour by weight.
Here, the wood powder particles include a wood powder particle suspension using immature materials of conifers such as Japanese cedar and Japanese cypress and broad-leaved trees such as Mizunara, and a wood powder particle suspension using mature materials of the conifers. Using these same types, after forming a wood powder particle suspension using the sapwood or mature wood of the conifer as an undercoat film, the heartwood or untreated wood of the conifer It is characterized by using a wood powder particle suspension using mature wood as a top coat film. According to the present invention, in addition to adhesion and the like, it is excellent in hygroscopicity, and it is possible to enhance the design of unevenness.
Moreover, it is preferable that the content of the immature material is at least 20% by weight or more. Regarding the particle size (pulverized particle size) of the immature wood, the aspect ratio of the treated wood flour is lower in the portion where the height of the tree is lower, making it easier to pulverize. On the other hand, with respect to sapwood and heartwood, sapwood has a higher aspect ratio of the treated wood flour and is easily pulverized.
Here, immature wood, mature wood, sapwood and core wood used in the present invention will be explained. As shown in FIG. 1 and Table 1, the "heartwood" refers to the dark-colored central portion of the cross section of a log such as cedar wood. A heartwood substance is formed in the heartwood and is generally resistant to decay. In addition, "immature wood" refers to the part where the fiber length is short and the strength is small until a certain age from the center, and defects are likely to appear even if lumbered. It is said that there are about 10 to 15 annual rings from the center. The outside of immature wood is called mature wood. Technically, "the wood formed by the cambium in the mature stage is defined as mature wood, and the wood formed by the cambium in the immature stage is defined as immature wood" (Non-Patent Document 3). Heartwood is formed from the central part such as the trunk and the reed when the tree reaches about 10 years of age, but immature wood is formed from the initial stage of growth regardless of the age of the tree.
According to the present invention, by making the average particle size 50 μm or less in a state containing cellulose, excellent adhesion (adhesion), heat insulation, moisture absorption, design (film formation), etc. due to the structure derived from wood are obtained. It is possible to give excellent features to More specifically, fine fibers that are partially CNF-ized on the surface of wood flour (the surface layer is partially CNF-ized, or the surface becomes fluffy) are physically entangled in the process of forming a coating film. (The CNFs on the surface are entangled, or the fluffs on the surface are entangled), and it is presumed that they are bonded more firmly by hydrogen bonding or the like.
In addition, it was presumed that there would be the following effects. (1) The moisture contained in the wood contains organic components, which are specific to the species, but the extracted components firmly bind the wood flour together. (2) For the base material, it contains a component that enhances adhesion to the base material, a component that acts as a binder, or a component that is suitable for overcoating.
Due to the above effects, when this suspension is used as a paint, it has excellent adhesion (adhesiveness), quick drying (ultra-quick drying), and moisture absorption, and has almost the same value as commercially available acrylic resin for aluminum painting. is considered to indicate
It was also effective to add CNF separately to further improve film properties and ease of application.
Also, a wood powder coating film (a coating film, a coating film, a coating film) having a heat conductivity of 0.06 W/mK, which is equivalent to that of glass wool, could be produced. Furthermore, depending on the wood powder, it is possible to form a film with excellent antifungal properties. Therefore, it is suitable for use as an exterior wall coating agent, a floor coating agent, or a surface treatment agent for these.
In the case of lumber such as cedar, cypress, and mizunara, it is preferable to use a portion whose height from the ground is within 2 m to 3 m. The immature part (about 10 to 15 annual rings) remains low in strength even after 100 years. In addition, most of the heartwood A2 is immature wood A3 in trees aged 60 years or older (Fig. 1). In addition, since the portion within 2 m to 3 m in height from the ground is close to the soil portion, it is considered that the organic component in the soil is also absorbed and contained in large amounts. These parts are disposed of as waste in the lumbering process, or are left in the forests during felling, so their recycling can be said to be the use of environment-friendly materials. Immature wood (soft) A3 is easy to refine, and can be easily sorted by classification and classification of wood (although it depends on the species, color tone and smell are often different), making it easy to manufacture. . In addition, these parts retain the color of the wood, making it easy to use when painting indoor walls and pillars, as well as metals such as aluminum. Due to these characteristics, the liquid of the present invention can be manufactured at a low cost, and can be manufactured at the same level as a commonly used paint.

In the present invention, wood flour obtained by pulverizing and classifying Japanese cedar, Japanese cypress, and Mizunara oak was used as the raw material. Films were prepared from the treated suspensions and tested for heat transfer properties, mildew resistance and coefficient of friction. The wood flour particles are those of soft trees such as Japanese cedar and Japanese cypress and broad-leaved trees such as Mizunara oak. It is more preferable that these immature woods are the remaining roots attached to the tree, regardless of the age of the tree. Moreover, it is preferable to classify by the particle size which can pass through a sieve of 200 meshes (opening of 75 μm).
(Structure of ligno-CNF by grinder treatment)
FIG. 2 shows microscopic images of cedar wood powder prepared under different conditions. Fig. 2(a) shows cedar wood powder of sapwood portion A1, which is a raw material, and distorted shape particles and fine fine particles having a size of about 100 µm are observed. When this was classified and coarse particles were used as the raw material, FIG. 2(b) shows that the particles were light-colored and about 20 μm in size. After the treatment of the classified fine particles of the sapwood portion A1, fine particles with a size of 30 to 50 μm were formed, which is finer than the treatment of the coarse particles (FIG. 2(d)). On the other hand, the grinder-treated fine core material A2 shows a large number of light-colored particles of several μm, which are considered to be CNF (FIG. 2(c)). It was found that these sites (heartwood A2 and immature wood A3) are suitable for the CNF conversion of the present invention.
It is also possible to add sapwood A1 of Japanese cedar, Japanese cypress and Quercus crispula. As a result, even coarse pulverization can be mixed with each other by a grinding machine or the like equipped with a grindstone. By mixing sapwood (or mature wood) with immature wood as described above (at least 20% by weight or more as a proportion of immature wood), excellent heat insulation and moisture absorption function can be achieved, and unevenness can be achieved. A sense of design can be provided.
(Viscoelasticity evaluation of wood flour gel by rheometer)
Using a rheometer, the viscosity and storage elastic modulus of wood flour paint (or wood paint) with a concentration of 2% prepared by changing the particle size of sapwood A1 of Japanese cedar were investigated, and the structural analysis was performed. FIG. 3(a) shows the shear rate dγ/dt dependence of the viscosity η of the suspension when coarse wood flour is used as the raw material, and FIG.
Under the condition that the distance between the plates of the rheometer is as large as 200 μm, η of the suspension made from coarse particles was 1×10 3 mPa·s or less. In addition, there was a tendency for η to be less dependent on dγ/dt. This indicates that this wood flour paint (or wood paint) has viscosity characteristics as a Newtonian fluid, indicating that nanofiberization has not progressed so much. On the other hand, when fine wood flour of heartwood A2 and immature wood A3 is used as raw materials, η is 2×10 ⁴ mPa s, which is more than 20 times that of the coarse case, and η depends on dγ/dt. got bigger. This liquid exhibited properties as a pseudoplastic fluid. From these results, it was found that there are parts that are easily defibrated and parts that are not, depending on the part and grain size of the wood material. It was found that raw materials with finer particle sizes (heart material A2 and immature wood A3) are more likely to be made into nanofibers, and this portion is an effective raw material for producing lignocellulose nanofibers. Here, the term "pseudoplastic fluid" refers to a fluid that does not have a yield value and whose viscosity decreases when a force is applied. Since it exhibits a high viscosity until a force is applied, it has the property of behaving like a Bingham fluid. Bingham fluid (plastic fluid) means that butter can be spread on toast by applying force with a knife, but it will not start to move unless a certain amount of force is applied, but it yields the force necessary to make this butter flow. It is called stress and its value is called yield value. In particular, fluids that exhibit a constant viscosity, like Newtonian fluids, while having a yield value are called "Bingham fluids (plastic fluids)."

(Influence of parts of wood)
As shown in FIG. 2(d), the material prepared from cedar sapwood A1 became finer particles with a size of 30 to 50 μm than the treatment of coarse particles. On the other hand, as shown in Fig. 2(c), the material prepared from the cedar heartwood A2 and the immature cedar material A3 contained a large number of particles of several µm, and it was found that this site is suitable for making fine fibers.
The heartwood A2 and the immature cedar A3 of the root material of cedar, etc., had a high ratio of immature wood with immature cell tissues formed when the tree was young, and the strength performance was inferior (Fig. 1). On the other hand, the sapwood portion A1 of the root wood has a large proportion of mature wood that is old, has a mature cell structure, and has high strength performance. It is considered that the core material A2s of the cedar root material and the immature cedar material A3 are suitable for making fine fibers. These parts (heartwood A2 and immature wood A3) can be easily determined from their colors and annual rings, so it is easy to cut out and select and sort materials (see Non-Patent Document 2). The sapwood A1 of the cedar, cypress, and mizunara oak has a thick trunk even if the height of the sapwood A1 from the ground is within 2 m, and these parts (A1, A2, A3) have different colors and It can be easily determined from annual rings, and has the effect of being excellent in the adhesion (adhesiveness), thermal conductivity, design, and the like.

(Influence of particle size and part of raw material wood flour)
Wood powder paint prepared from coarse-grained wood powder (particle size: 60 mesh pass-100 mesh on (opening 150 to 250 μm) and fine-grained wood powder (200 mesh pass (opening 75 μm pass)), and the site ( The fibrillation state of the wood powder paints prepared by changing the cedar core and cedar sapwood (particle size: 200 mesh pass) was observed under a microscope.
(Influence of particle size of raw material wood flour)
As shown in FIG. 2(b), when coarse-grained wood flour was used as the raw material, the particles were about 20 μm. On the other hand, when fine-grained wood flour is used as the raw material, as shown in Fig. 2(c), there are many particles of several micrometers, and it was found that fine-grained wood flour is more suitable for refining. .
When the wood is pulverized by a pin mill (using a pin disk rotary pulverizer), soft tissues such as early wood parts and parenchyma cells that make up the wood are pulverized into wood flour with a small particle size. It is thought that hard structures such as crucifixes have large grain sizes and are pulverized. In the same way, it is thought that nanofiber formation tends to be easier for soft portions.
Here, the term "latewood" refers to a portion of one growth ring of wood that is formed in the latter stage of the growing season. In coniferous trees, tracheids with thick cell walls and small diameters are formed, while in broadleaf trees, thin vessels are formed. This area is dense and often appears dark. In addition, the wood part that grows early in the spring in the annual rings is called early wood (spring wood), and the cell shape is large and the cell membrane is thin. The wood that grows after summer when growth slows down is called late wood (autumn wood, summer wood), and the cell shape is small and the cell membrane is thick.

The present invention uses conifers such as cedar and cypress and broadleaf trees such as Mizunara as raw materials (irrespective of the age of the tree, the immature part with the remaining roots cut at a height of about 2 m to 3 m from the ground). It is more preferable that it is wood.), and it is characterized by adding only water and stirring to make it into a paint (natural paint) to give it performance. Alternatively, when immature wood and/or heartwood of Japanese cypress is used as a raw material, it is characterized in that it also has antifungal performance. Here, the above is cypress, and it can be a coating film in which an antifungal (mold) component such as hinokiol appears on the surface.
By using lignocellulose nanofibers with a nanofiber structure as a part of wood flour, a biomass material, the coating has excellent heat insulation and film-forming properties due to the wood-derived structure. , In addition, it can be used as a water-based wood preservative or a water-based wood insect repellent, used as a woody film with excellent antifungal performance, used as a pigment or adsorbent, and has a thermal conductivity of 0.06 W / mK. A wood powder coating film (paint film, coating film, coating film) equivalent to glass wool can be produced.

Various wood raw materials were pulverized with a grinder (Mascolloider manufactured by Masuko Sangyo Co., Ltd.) to prepare wood powder paints, and their performance was evaluated. As a result, the following facts were clarified.
1. Depending on the particle size or part of the wood powder of the raw material, the easiness of pulverization by the grinder equipped with the above-mentioned grindstone differs. .
2. The wood powder paint prepared according to the present invention had adhesion (adhesiveness) equivalent to that of general paint.
3. When the coating film of the wood powder coating material of the present invention was hot-pressed at a temperature ranging from room temperature to 160°C, the coating film had a very high hardness. That is, the heat press treatment turned the lignocellulose component into a resin and increased the surface hardness, but the highest temperature was obtained at a heating temperature of 160°C (described later). Even if pressed at room temperature, a coating film with excellent adhesion can be formed.
4. The coating film of the wood flour paint of the present invention had low thermal conductivity and excellent heat insulation.
5. The coating film prepared from the cypress heartwood of the present invention was excellent in antifungal performance.
6. The wood powder paint of the present invention was able to form a coating film with a unique sense of design (unevenness). In particular, by mixing immature wood with sapwood (or mature wood), it was possible to provide a textured design.

According to the method of extracting the immature wood portion of the tree of the present invention, even if the remaining rooted wood that has been cut at a predetermined height above the ground has annual rings and color on the cut surface, , Judging that it contains a predetermined amount of moisture from the smell, etc., paint agents (including exterior wall paint agents, floor paint agents, or these surface treatment agents.), pigments, adsorbents, anti-mildew ( It becomes possible to easily collect the raw material of the wood powder particle suspension such as the mold agent by cutting.
In addition, according to the method for producing the wood flour particle suspension of the present invention, the CNF content in the suspension is increased by pulverizing the coniferous trees such as cedar and cypress, which are easily made into nanofibers, as raw materials. and the residual amount of distorted fine particles can be reduced, so the coating film when using the wood powder fine particles has an increased film density and excellent heat insulation and film-forming properties due to the structure derived from wood. A coating film with excellent adhesion can be produced from wood flour, the coating coefficient can be as small as 0.14, and the high anti-mold performance of hinoki is demonstrated. It was confirmed that The same applies to immature materials such as Japanese cedar, Japanese cypress, and Mongolian oak whose height from the ground is within 2 m. For these reasons, the present suspension can be used as a raw material for water-based paints, water-based paints, powder paints, synthetic resin paints, and the like.
And 1. 2. excellent heat insulation and adhesion; 3. excellent touch feeling and smoothness; It must be easy to combine with synthetic resins and inorganic materials. Since it has active ingredients such as antibacterial and antifungal properties, it is used as a coating film-forming component (coating film-forming composition) for anticorrosion, antiseptic, antifungal, anti-termite, antifouling, waterproof, sterilization, etc. Used as a coating film-forming component (coating film-forming composition) for heat shielding, water repellency, fluorescence, phosphorescence, camouflage, adsorption of harmful chemical substances, smoothing, glossing, coloring, pattern, design, landscape creation, etc. It can be used as a forming component (coating film forming composition). In addition, it can be applied to coating agents (exterior wall coating agents, floor coating agents, or these surface treatment agents, and by forming these into a multi-layer coating film, adhesion and design can be improved.
Polypropylene resins, alkyd resins, unsaturated polyester resins, melamine resins, urea resins (amino resins), phenol resins, epoxy resins, vinyl chloride resins, acrylic resins, acrylic urethane resins, In the case of acrylic silicone resins, fluorine resins, etc., they can be used by mixing with the suspension.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining immature wood, mature wood, sapwood, and core wood which are used by this invention. FIG. 4 is a diagram showing microscope images of cedar wood powder produced under different conditions. FIG. 10 is a graph showing shear rate dγ/dt dependence of viscosity η of a wood flour suspension processed by a grinder. FIG. 1 is a diagram showing a portion of wood used in the present invention, a manufacturing method using the same, antifungal performance when a wood powder coating film is formed, and thermal conductivity when a wood powder coating film is formed. It is a figure which shows partial CNF conversion of wood flour. FIG. 2 shows the results of JIS Z 2911 test of various coating films. FIG. 10 is a diagram showing the appearance of wood powder paint-coated aluminum plates that were experimentally produced by changing the coating method. FIG. 4 is a diagram showing the planar tensile strength of the coating film of the coated aluminum plate for each raw material. 2 to 4 in Non-Patent Document 2. FIG. It is a figure which shows the conventional problem.

Embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

(Conversion of wood flour to CNF)
FIG. 5(a) is a diagram for explaining the partial conversion of wood flour into CNF, and FIG. 5(b) is a diagram for explaining the formation of a wood flour coating film.
First, the raw material wood powder is pulverized by a pin mill (S1) after sorting out the above-mentioned parts, thereby obtaining wood powder suitable for making fine fibers. Next, the wood flour suitable for making fine fibers is subjected to a wet grinder treatment (S2). In wet grinder processing, the roughness of the mortar used is #46 or less, or in the range of #46 to #120.
In this way, a partially CNF-converted wood flour is obtained (S3). Partially CNFized wood flour is wood flour that has been CNFized only on the surface (atomized such that the surface is fluffed or whiskered), as shown in an enlarged view in S4. The average particle size of the wood powder particles is preferably 10 μm or less (or preferably 3 to 10 μm) (FIG. 5(a)).
As shown in FIG. 5(b), the wood flour in which only the surface is CNF-ized as shown in S4 is strongly bound by entanglement of the CNFs on the surface of the wood flour (in FIG. 5(a), only the surface is CNFized (surface The fluffed portion (Ba is 3 μm or less) functions as a binder and forms a coating film with high hardness and excellent heat insulation. It is highly safe because the raw materials are only wood powder from wood such as cedar and water. It has good water absorption and oil absorption, and excellent wettability with water, so it can be used in various applications by mixing it with other materials (etc.).
In this case, the substrate (coating substrate) K1 is not particularly limited, and various commonly used substrates (substrates made of synthetic resin such as acrylic or aluminum) can be used. It can be selected and used as appropriate.

(Preparation of wood powder paint/wood paint)
Raw materials shown in Table 2 are cut out from Bokasugi from Toyama Prefecture, cypress root logs from Iwate Prefecture, and mizunara oak from Iwate Prefecture. , wood flour having an average particle size of 500 μm or less was prepared. Next, this wood powder is put into a grinder equipped with the above grindstone (wear wheel G#80 or G#46) by a wet method, and the treatment is repeated three times to prepare a wood powder paint (solid content 10%). did. As a result, it was confirmed that wood flour paints (or wood paints) could be produced from all raw materials. The Bokasugi and Hinoki cypress produced in Toyama Prefecture used here are cutting varieties that are common in the western part of Toyama Prefecture.
Table 2 shows the types of wood powder paints prepared from various types of wood. Here, "mesh" is a unit that indicates the mesh size of a sieve, and indicates how many parts 1 inch (2.54 cm) is divided into, that is, how many meshes pass through it. (new JIS). The "coarse" wood powder particle size before fine pulverization shown in (1) of Table 2 (a) is the particle size that passes through a 60 to 100 mesh sieve (opening 150 to 200 μm), and (2) The "fine" wood powder particle size shown in 1 is a particle size that passes through a sieve of 200 mesh (opening of 75 μm) (new JIS). Further, the larger the masscolloider wear wheel No. shown in (3), the finer it is pulverized. "Mascolloider" is a product name of Masuko Sangyo Co., Ltd.

(Properties of wood powder paint)
a) Adhesion (flat tensile strength)
Fig. 7 and Fig. 8(a) show the appearance of the coating film of the wood powder paint (or wood paint) coated aluminum plate and the planar tensile strength of each raw material. The planar tensile strength of the wood powder coating film is in the range of about 12 to 14 N/cm ² for all raw materials, which is almost the same as the existing acrylic resin for aluminum coating (about 13 N/cm ² ). It showed the adhesion of the membrane. Fine fibers partially converted to CNF on the surface of wood flour are physically entangled in the process of forming a coating film by a grinder equipped with the grindstone (a millstone-type grinder composed of grindstones), and hydrogen bonding, etc. It is presumed that the binding was even stronger at 1 (Fig. 5).
b) Surface hardness (pencil hardness)
As shown in Figs. 8(b) and 8(c), the structure of the aluminum plate coated with wood powder was obtained by pressing an aluminum plate coated with wood powder paint (or wood paint) and acrylic resin (acrylic primer). .
The surface hardness (pencil hardness) was measured at different press temperatures. For all the raw materials, the pencil hardness improved with increasing pressing temperature, especially at a pressing temperature of 160.degree. Hard sheets used in commercially available PCs and the like have a pencil hardness of 3H to 4H, and the automotive coating film JIS (JIS D 0202) specifies that the maximum coating film hardness evaluation is 5H. The wood powder coating film pressed at ℃ is very hard compared to existing coating films. In addition, it can be pressed at room temperature (without baking and painting), has excellent adhesion, makes the appearance of the object to be painted beautiful, and has the effect of protecting the surface (see FIG. 8 (b)). ) function.

The pencil hardness improved with increasing press temperature, and became very high at 6H to 7H at a press temperature of 160°C. In addition, the color of the wood remains, making it easy to use when painting indoor walls and pillars.

c) Thermal Conductivity The wood powder particle suspension M using cedar or the like can be expected to be applied as a heat insulating material with low thermal conductivity. In order to investigate whether the value changes with the amount of nanofibers in the suspension and the size of the wood powder particles, the thermal conductivity was evaluated by the steady-state method and the heat flow meter method. Table 4 shows the results when the wood powder paint (or wood paint) of the heartwood A2, the immature wood A3, and the sapwood A1 was used as a coating film.

Although the wood flour did not form a film and was in a flaking state, it exhibited a very small thermal conductivity of 0.045 W/(m·K). The film of the sapwood portion A1 was increased to 0.105 W/(m·K) by the grinder treatment. On the other hand, in the heartwood portion A1 and the immature wood A3, the increase was only slightly from 0.062 to 0.082 W/(m·K) due to the treatment. This indicates that the sapwood A1 has finer grains and a larger volume of the nanofiberized portion, thereby improving the film density. From the above, it was clarified that in the case of cedar, it is more suitable to use the core part when using a coating film as a heat insulating material.

d) Preparation of wood powder paint (preparation of paint using wood fine particles M containing water)
Raw materials shown in Table 2 are cut out from Bokasugi from Toyama Prefecture, cypress root logs from Iwate Prefecture, and mizunara oak from Iwate Prefecture, dried naturally indoors, then finely pulverized with a pin mill pulverizer and classified with a vibration sieve to obtain a particle size. A wood flour of 500 μm or less was prepared. Next, this wood powder was put into a grinder equipped with the grindstone (wear wheel G#80 or G#46), and the treatment was repeated three times to prepare a wood powder paint (solid content: 10%). As a result, it was confirmed that the wood powder particle suspension M, which is a wood powder paint, can be produced from all raw materials.

A membrane was produced from the produced wood flour suspension (wood particles containing water) M, and its antifungal performance was tested. A JIS Z 2911 test was performed on a coating film using Japanese cedar and a coating film using Japanese cypress. The results are shown in FIG. The black part is mold. The anti-mold (mold) performance of the cedar coating film varies from 4: (mycelium grows well, and the area of the growing part is 50% or more of the total area of the sample) to 5: (mycelium grows vigorously, and the entire surface of the sample However, the cypress coating showed 2: (mold growth was observed with the naked eye, and the area of the growing part was less than 25% of the total area of the sample) to 0: (with the naked eye and under a microscope No fungal growth was observed). The biodegradability of Japanese cedar was enhanced by making nanofibers, making it easier for mold to grow. In Hinoki, however, antifungal components such as hinokiol appeared on the surface of the wood, and it is thought that the growth of mold was suppressed. Hinoki cypress has the effect of chemically reacting with malodorous components in the extracted essential oil to decompose it (deodorant effect), so this may be further mixed with the suspension.

A coating film Mm having excellent adhesion to the substrate was produced from the wood powder particle suspension M. As a result of examining the thermal conductivity and antifungal properties of this coating film Mm, it was confirmed that the thermal conductivity was as low as 0.1 W/(m·K) or less and that the coating film had high heat insulating performance. In addition, it can be confirmed that the coefficient of friction of the coating film Mm is as small as 0.14, and that it also has the texture of wood. Indicated. In addition, the high antifungal performance of Japanese cypress was also confirmed. Applications that take advantage of these features can be expected.

(Appearance design of wood powder paint)
In order to give the painted surface a design with unevenness, coarse wood powder (32 mesh pass - 60 mesh on (opening)) selected from the same part as the mixed paint is added to the cedar sapwood and wood powder paint (or wood paint) 500 μm pass-250 μm on)) was mixed with 50% and 100% of the solid content of the wood powder paint (wood paint), and the wood powder paint coated aluminum plate (thickness 1 mm) with different design feeling was prepared. On the other hand, a wood powder coating film Mm having a thickness of 0.1 to 0.2 mm was experimentally produced. As a result, it became possible to form a coating film with an uneven surface and a unique design feeling of wood flour paint (Fig. 7).
Here, the undercoating process (a process to firmly solidify the base to increase the adhesion of the intermediate coating material and top coating material) is performed with acrylic paint, and then the intermediate coating process (patterning, giving elasticity, heat insulation) A process to give functional added value such as imparting) was performed with wood flour particle suspension (prepared from wood flour with coarse particle size) M1 (Fig. 7(a)). Furthermore, the overcoating step (the step of imparting weather resistance, heat shielding properties, etc.) was performed with a wood powder particle suspension prepared from wood powder having a coarse particle size (M2).
Also, an aluminum plate (thickness 1 mm) was used as the base material (resin base material) K1, but other decorative boards (acrylic plate, etc.) can be used. Moreover, the wood powder particle suspension M can be used not only for acrylic resin coatings but also for polyurethane resin coatings, fluorine resin coatings, epoxy resin coatings, and vinyl chloride resin coatings.
The present invention also provides a wood powder particle suspension using the heartwood or immature wood of conifers such as Japanese cedar and Japanese cypress and broad-leaved trees such as Mizunara, and wood powder particles using the sapwood or mature wood of the conifers. Using these same types of suspensions, the wood powder particle suspension using the sapwood or mature wood of the coniferous tree is formed as an undercoat film, and then the heartwood of the coniferous tree. Alternatively, a wood flour particle suspension using immature wood is used as a top coat film. The ratio of the immature material is preferably at least 20% by weight or more. If the amount is less than 20% by weight, the properties of immature wood (adhesion, heat insulation, etc.) are not sufficiently exhibited, but when mixed with sapwood (ripened wood), there was no effect on the design of unevenness. .
When a water-based paint is prepared using the wood powder particle suspension M to which the present invention is applied, it can be applied as an exterior wall coating agent, a floor coating agent, or a surface treatment agent for these only by adding water. In addition, it can be pressed at room temperature (without baking and painting), has excellent adhesion, makes the appearance of the object to be painted beautiful, and has the effect of protecting the surface (see FIG. 8 (b)). ).

The water-based paints were prepared in Examples 1-5 (5-20% by weight solids) and Comparative Examples 1-3 (25-50% by weight solids) and mixed in a high-speed mixer at 2000 rpm for 5 minutes. let me

(Adhesion test to substrate)
In the adhesion test to the base material, a strip of 20 cm long and 10 cm wide was coated on the center of the aluminum plate K1 and dried at room temperature for 1 to 2 hours. Next, for the suspensions of Examples 1 to 5 and Comparative Examples 1 to 3, the wood powder particle suspensions obtained based on the Examples were applied using a coating tool. After that, a coating film was produced by curing it with a normal temperature press (FIG. 8(b)). The evaluation of adhesion to the base material is as follows: ○ when the applied state of the paint is maintained when rubbed with a brush; △ when the painted part peels off; was evaluated in 3 stages with x. There was no difference in the wood flour particles and components of immature wood between Bokasugi 60 years old or more and Bokasugi 10 years old or less. In addition, there was no difference in the wood flour particles and components of the immature materials between the Mizunara oak trees of 60 years or older and the Mizunara oak trees of less than 10 years old.

(Topcoat adhesion test)
Water-soluble paints prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were air-sprayed onto acrylic plate K1 under the conditions of a temperature of 25°C and a humidity of 70% to obtain a suspension of wood powder particles. was applied and cured by pressing at room temperature to prepare a coating film (FIG. 8(b)). Next, as a top coating, a coating film cured by pressing at room temperature was produced (FIG. 8(b)). Evaluation of the adhesion of the topcoat is as follows: ○ when the coating state is maintained when rubbed with a brush; It was evaluated in three stages.

(Test as an adsorbent)
Wood has the ability to adsorb ammonia gas, etc., and its adsorption ability can be clarified by measuring its hygroscopicity. Therefore, as a test for the adsorption of the coating film, the adhesiveness to the base material and the topcoat adhesiveness described above were tested, and then placed in a predetermined container in which the humidity was adjusted to 85% by inserting an aqueous potassium chloride solution. sex measurements were taken. If this test reveals hygroscopicity, it suggests that the coating film has the same adsorptivity as wood, and that the wood flour particle suspension can be used as an adsorbent. The evaluation was made on the basis of a three-point scale: ◯ when having the same hygroscopicity as wood, Δ when slightly hygroscopic, and x when poor hygroscopicity. As a result, as shown in Table 5, in Examples 1 to 5 in which the wood powder particles of the wood were 1 to 20% by weight and the water or solvent was 80 to 99% by weight, the base material K1 Adhesion, adhesion as a topcoat, and adsorbent tests were all good (⊚).

(thixotropy)
Thixotropy refers to a phenomenon in which viscosity is reduced by applying force, such as by stirring or shaking. Pseudoplastic fluids and thixotropic fluids are the same in that the viscosity is reduced by stirring. be. Fluids exhibiting thixotropy decrease in viscosity when a constant force is continuously applied, and return to the original state when the decreased viscosity is left for a certain period of time. In addition, a familiar application of thixotropic properties is paint. Stirring the paint makes it less viscous and easier to apply, making it easier to apply to walls with a brush or roller. Stirring well before applying paint not only eliminates color unevenness, but also brings out thixotropic properties. In addition, the paint applied to the wall immediately becomes viscous (returns to its original state) and dries without dripping.
When the present invention is applied to a water-based wet paint, it becomes a water-based paint containing a binder such as a water-based resin, a solvent, and water-based paint components such as pigments and other additives as necessary, and water. The surface tension is reduced sufficiently to demonstrate the uniformity of the surface tension, suppressing the roughness of the coating film surface due to local variations in the surface tension, and exhibiting excellent thixotropic performance.
From the above results, the wood powder particle suspension of the present invention is suitable for use as an exterior wall coating agent, a floor coating agent, or a surface treatment agent for these. As a surface treatment agent, it is used as a pretreatment when painting exterior walls or floors with synthetic resins such as acrylic resins. However, by applying the wood powder particle suspension of the present invention, a coating film with high hardness can be formed, and a coating film with excellent adhesion can be formed even by press molding at room temperature. was made.

As described above, in the present embodiment, a method for producing a wood flour suspension containing CNF as a coating film or a coating composition has been mainly described. INDUSTRIAL APPLICABILITY The present invention can be applied to various coating films such as paints, pigments and adsorbents, and is suitable for use as an exterior wall coating agent, a floor coating agent, or a surface treatment agent for these. For further improvement of workability and film properties, it is possible to add CNF separately to the wood flour particle suspension of the present invention while further adjusting the water content.

A1 root sapwood,
A2 heartwood,
A2s root heartwood,
A3 immature wood,
A3s Immature wood at the base,
A4 mature wood,
M wood flour particle suspension,
M1 wood flour particle suspension (prepared from coarse wood flour),
M2 wood powder particle suspension (prepared from fine-grained wood powder),
Mm wood powder coating (coating film),
Mt paint,
K1 base material (resin base material)

Claims (14)

Extracting immature timber from conifers such as cedar and cypress or from broadleaf trees such as Quercus crispula A method of extracting immature timber from trees in which the remaining roots cut at a predetermined height above the ground are Judging from the tree rings attached, wood powder particle suspensions such as coating agents (exterior wall coating agents, floor coating agents, or these surface treatment agents), pigments, adsorbents, anti-mold agents, etc. A method for collecting immature wood from a tree, characterized in that the raw material for the turbid liquid is collected by cutting. The portion of immature wood has a height of about 2m to 3m from the ground, and if the tree is about 20 to 30 years old, it is a portion within 15 years old from the center of the wood. A method for harvesting immature wood portions of trees according to claim 1, characterized by: The immature wood portion of the tree collected by the method according to claim 1 or 2 is treated with a coating agent (including an exterior wall coating agent, a floor coating agent, or a surface treatment agent for these), a pigment, an adsorbent, and an antifungal agent. (Mold) agents, etc., are used as raw materials for suspensions, and only water content is adjusted by a wet pulverization method (the amount of wood flour is 1 to 20% by weight relative to water), and coating agents (exterior wall coating agents, floor coating agents, or , including these surface treatment agents), pigments, adsorbents, anti-mold agents, and the like. A method for producing a wood powder particle suspension collected by the method of. In a suspension of wood flour particles containing cellulose nanofibers, which is treated by a wet grinding method after dry grinding wood with an impact grinder or the like, wood flour having a nanofiber surface and A wood flour particle suspension in which cellulose nanofibers separated from wood flour and lignin or hemicellulose are mixed, wherein the average particle size of the wood flour is 50 μm or less, and the cellulose nanofibers contained in the suspension are A wood flour particle suspension characterized by having a concentration of 50% or less of wood flour by weight. The wood includes conifers such as cedar and cypress and broad-leaved trees such as Mizunara, and the wood flour particles of the wood include immature wood of the wood (irrespective of the age of the tree, the height position from the ground is about 2 m to 3 m). 5. A wood flour particle suspension according to claim 4, characterized in that it more preferably contains immature wood of the remaining rooted part of the tree felled in . The wood is coniferous trees such as Japanese cedar and Japanese cypress, and broadleaf trees such as Mizunara oak. It is more preferable to include mature wood.), and the wood flour particles of the wood are a mixture of mature wood and immature wood (including at least 20% by weight of immature wood). ), wherein the mature wood and the immature wood include the immature wood of the remaining rooted part of the tree cut at a height of about 2 m to 3 m from the ground. The wood flour particle suspension according to claim 4 or 5. The wood powder particles of the wood are 1 to 20% by weight and the water is 80 to 99% by weight, and a coating agent (including an exterior wall coating agent, a floor coating agent, or a surface treatment agent thereof), 7. The wood flour particle suspension according to any one of claims 4 to 6, which is used as a pigment, an adsorbent and an antifungal agent. After dry pulverizing the wood with an impact pulverizer or the like, it is then processed by a wet pulverization method. Wood flour with a nanofiber surface after pulverization and classification, and a wood flour particle suspension in which cellulose nanofibers separated from the wood flour, lignin, and hemicellulose are mixed in the suspension. A method for producing a wood flour particle suspension, characterized in that the average particle size of the powder is 50 μm or less, and the concentration of cellulose nanofibers contained in the suspension is 50% or less of the weight of the wood flour. . The wood powder particles to be wet-pulverized are powder particles of coniferous trees such as cedar and cypress and broad-leaved tree powder particles such as Mizunara oak, and are characterized by being classified by a particle size that passes through a sieve mesh smaller than 200 mesh (opening 75 μm). The method for producing a wood flour particle suspension according to claim 8. The wood is coniferous trees such as cedar and cypress and broad-leaved trees such as Quercus crispula, and the wood powder fine particles of the wood include immature wood of the wood (irrespective of the age of the tree, the height position from the ground is about 2 m to 3 m). 7. The method for producing a wood flour particle suspension according to claim 5 or 6, characterized in that it contains immature wood of trees with remaining roots that have been cut down. The wood is coniferous trees such as Japanese cedar and Japanese cypress and broad-leaved trees such as Mizunara oak (regardless of tree age), and the wood flour particles of the wood are a mixture of mature wood and immature wood. Contains at least 20% by weight of immature wood. ), the mature wood and the immature wood are parts with a height of 2 m or less from the ground (remaining roots cut at a height of 2 m to 3 m from the ground) 7. The method for producing a wood flour particle suspension according to claim 5 or 6, characterized in that immature wood of said wood in the attached portion is more preferably included. The mixing ratio of the wood powder particles is 1 to 20% by weight and the water is 80 to 99% by weight, and the coating agent (including an exterior wall coating agent, a floor coating agent, or a surface treatment agent thereof), a pigment, 12. The method for producing a wood flour particle suspension according to any one of claims 3 to 11, characterized in that it is used as an adsorbent and an antifungal agent. In the method of manufacturing coatings applied to synthetic resins and metal substrates containing acrylic and aluminum, wood cut as raw material is naturally dried indoors, finely pulverized and classified, and then wet pulverized. In the treatment of the method, the average particle size of the wood flour was reduced to 50 μm in a state where the wood flour with a nanofiber surface and the cellulose nanofiber separated from the wood flour, lignin and hemicellulose were mixed in the suspension. A coating film obtained by applying a wood flour particle suspension to the synthetic resin substrate below, wherein the concentration of cellulose nanofibers contained in the suspension is 50% or less by weight of the wood flour, and a method for producing a coating film using a suspension of wood flour particles, wherein the coating film is formed by pressing at room temperature. The wood powder particles to be wet-pulverized are wood powder particles of conifers such as cedar and cypress and broad-leaved trees such as Mizunara (irrespective of the age of the tree, the height position from the ground is about 2 m to 3 m). It is preferable that it is an immature material of the above-mentioned wood in the part with the roots.), classified by a particle size that passes through a sieve mesh smaller than 200 mesh (opening 75 μm), and then by a wet pulverization method. , Wood flour having a nanofiber surface, and cellulose nanofibers separated from the wood flour and lignin and hemicellulose in a suspension are mixed, and the wood flour is pulverized to an average particle size of 10 μm or less. 14. The coating film using the wood flour particle suspension according to claim 13, wherein the wood flour particle suspension is applied to the synthetic resin substrate and pressed at room temperature to form the coating film. manufacturing method.

Images