JP2673916B2 - High bulk density wood flour and method for producing high bulk density wood flour - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high bulk specific gravity wood flour and a method for producing high bulk specific gravity wood flour. More specifically, it is used as a filler in plastic molded products, plastic sheets, plastic films and paints. The present invention relates to a high bulk specific gravity wood flour used and a method for producing the high bulk specific gravity wood flour.

[0002]

2. Description of the Related Art Conventionally, the characteristics of natural wood, especially,
In order to obtain various plastic molded products, plastic sheets, plastic films (hereinafter simply referred to as plastic products), etc. having surface characteristics similar to those of natural wood, paints for various furniture, daily necessities, etc. In order to give the same characteristics to the surface coating or film of the above, fine powder wood powder is applied to the plastic material of plastic products, the surface coating of furniture, daily necessities, etc., or the paint forming the film. Attempts to include it.

As a conventional typical wood powder improved in this respect, there is, for example, a surface polishing powder in a particle board which is hardened with a urea resin. The main reason for using such particle board surface polishing powder is that the particle board surface polishing powder is fine and has a "grain" shape with relatively few cilia. That is, depending on the surface polishing means for the particle board, it is possible to easily obtain a fine and finely-powdered finely-powdered polishing powder, particularly finely-powdered polishing powder having good dispersibility in a molding resin material for plastic products and the like. There is a point that can be.

On the other hand, however, this type of particle board surface polishing powder is obtained because the material characteristics of the particle board itself, which is the object of polishing, do not have a homogenized average wood property. The resulting finely divided abrasive powder may not have the properties of a homogenized average wood. In addition, since the hard portion that accompanies the curing treatment with the urea resin is inherited by the finely powdered abrasive powder obtained, the essential hygroscopicity and moisture release characteristic of ordinary wood flour can be achieved. There are problems such as chipping and lacking in the soft feel of wood flour.

From this point of view, conventionally, the raw wood is mechanically broken by a cutter mill or the like, and the raw wood is crushed by a crusher using an impact, shearing or grinding means, for example, an impeller mill. It has been attempted to use wood powder which is made into a fine powder and retains the moisture absorbing function and moisture releasing function of the raw material wood itself.

[0006]

However, when the surface polishing powder of the particle board is mixed with and dispersed in a molding resin material of a plastic product to obtain a plastic product by plastic molding, Alternatively, when a resin coating film was obtained by mixing and dispersing in a resin paint, the obtained plastic product or coating film did not have a sufficient and uniform moisture absorption function, and the obtained plastic product or coating film was touched. It had the drawback of giving a sticky feel. In addition, the plastic products and coating films containing the surface polishing powder of the particle board have a hardened portion of the thermosetting resin possessed by the surface polishing powder on the surfaces of the plastic products and coating films, which is peculiar to wood. There is a disadvantage that these plastic products, coating films, etc. do not have a soft feel.

Next, in the wood powder obtained by crushing the raw material wood by using a crusher such as an impeller mill which acts by impact, shear, friction, etc., various inherent peculiar characteristics of the wood itself are obtained. While the functions are effectively retained, the resulting wood powder has angular parts, protruding parts, cilia-shaped beard parts, and many fibrous elongated wood powders. However, there is a disadvantage that the dispersibility in a solvent such as a coating liquid and a coating liquid and the solution is extremely poor, and the resin cannot be uniformly dispersed in various plastic molding resin materials or sealing agents. Further, the wood powder thus obtained is liable to agglomerate in the process of crushing the wood powder and in the process of storing the wood powder obtained by crushing, and it is difficult to handle, especially during plastic molding or coating. In this case, there is a defect that they are aggregated in a molding resin material for these plastic products or in a paint.

Further, the chips and sawdust as the raw wood are not crushed by the action of impact, shear, friction, etc. of an impeller mill, etc., and the chips and sawdust are crushed by a friction action of, for example, a dry ball mill. When crushed directly using, the amount of long-fibrous wood powder occupied in the obtained crushed wood powder was large, while pulverized wood powder in the form of fine powder was particularly overcrushed, which was difficult to use. .

In view of the inconvenience of wood powder used as such conventional fillers, the present invention has an angular part, a protruding part, and a cilia-like fluffy part of the wood powder used. By removing as much as possible the outer surface shape of the wood powder, that is, wood powder having a large bulk specific gravity, the dispersibility in plastic molding materials, paints, etc. is improved, and the wood powder aggregates during handling. It is an object of the present invention to provide a high bulk specific gravity wood flour that does not occur and a method for producing a high bulk specific gravity wood flour having such characteristics.

[0010]

In order to achieve the above object, the high bulk specific gravity wood flour according to the invention of claim 1 is a wood flour obtained by classifying at the same time as crushing or after crushing. ,
By grinding by frictional action, the outer surface shape is substantially adjusted and the bulk specific gravity is made larger than that of the wood flour.

In order to achieve the above object, the high bulk specific gravity wood flour according to the invention of claim 2 is classified at the same time as pulverization,
Alternatively, the wood powder obtained by classifying after crushing has its outer surface shape substantially adjusted by crushing by a frictional action between crushing balls, and has a bulk specific gravity larger than that of the wood powder.

Further, in order to achieve the above object, the method for producing a high bulk specific gravity wood flour according to the invention of claim 3 is to grind and classify at the same time as the grinding, or grind and classify after the grinding. And a pretreatment step for obtaining wood flour, and a wood flour obtained by the pretreatment step is crushed by friction to make wood flour having a bulk specific gravity larger than that of the wood flour obtained by the pretreatment step. And a processing step.

Furthermore, in order to achieve the above object,
The method for producing high bulk specific gravity wood flour according to the invention of claim 4 is a pretreatment step of pulverizing and classifying simultaneously with the pulverizing, or pulverizing and classifying after the pulverizing to obtain wood flour, and the pretreatment. The wood powder obtained by the process is pulverized by a frictional action between the crushing balls to obtain a wood powder having a bulk specific gravity larger than that of the wood powder obtained by the pretreatment process. .

In the present specification, "wood flour obtained by classifying at the same time as crushing or by classifying after crushing" in claims 1 and 2, and claims 3 and 4 The "wood flour" obtained by the "pretreatment step of pulverizing and classifying simultaneously with the pulverizing or pulverizing and classifying after the pulverizing to obtain wood flour" is hereinafter referred to as pretreated wood flour. .

[0015]

[Function] When the pretreated wood powder is crushed by the frictional action, the angular portion, the protruding portion, the ciliary beard portion, etc. of the wood powder are gradually reduced, and the bulk specific gravity of the wood powder is reduced. Be made bigger. Further, the wood powder having such a large bulk specific gravity, that is, the wood powder having a high bulk specific gravity does not cause agglomeration between the wood powders, and has good dispersibility in a coating liquid and the like. Furthermore, since the pretreated wood powder obtained by crushing the raw material wood is made into a high bulk specific gravity wood powder by crushing by friction, various characteristics and functions of the raw material wood are
It is inherited by the high bulk density wood flour.

[0016]

EXAMPLES Hereinafter, typical examples of the high bulk specific gravity wood flour and the method for producing the high bulk specific gravity wood flour according to the present invention will be described in detail.

FIG. 1 shows the formation of pretreated wood powder 102 from a raw material wood 101 to which an embodiment of the present invention is applied, and the pretreated wood powder 102 is crushed by friction. In this embodiment, crushing is performed. It is a schematic explanatory drawing which each typically showed the high bulk specific gravity wood flour 103 obtained by grind | pulverizing by the frictional action between use balls. FIG. 2 is a longitudinal sectional front view of a main part showing an outline configuration of an open type dry ball mill according to an example for performing grinding by frictional action between grinding balls on the pretreated wood flour 102 in one embodiment of the present invention. is there. FIG.
FIG. 3 is a vertical sectional front view of a main part showing a schematic configuration of a closed dry ball mill according to an example for performing grinding by frictional action between grinding balls on pretreated wood flour 102 in one embodiment of the present invention. FIG. 4 is a longitudinal sectional front view of a main part showing a schematic configuration of a classifying apparatus according to an example for classifying the pretreated wood flour 102 and the high bulk specific gravity wood flour 103 in one embodiment of the present invention.

Prior to the detailed description of the embodiments according to the present invention, the main terms used in the description will be defined as follows. Regarding this definition, as mentioned earlier, the size of the wood powder itself to be treated as the subject of the invention is a very fine pulverized particle, so it can be inferred to some extent regarding its action. Considering that it is unavoidable, the definition is not always the only requirement. The "grinding by frictional action" and "grinding by frictional action between crushing balls" mainly mean pulverization by the action of friction with respect to an object to be pulverized by using a ball mill, and hereinafter, also referred to as grinding. In the present specification, the "ball mill" refers to a mill that mainly stirs grinding balls vertically and circumferentially by a stirring means and grinds them by friction between the grinding balls. It also includes a type ball mill and other ball mills.

It is to be noted that the pretreatment wood powder here has a substantially uniform outer surface shape by crushing by frictional action, which means that the pretreatment wood powder has a relatively elongated fibrous shape by crushing by frictional action. The wood powder is broken into a more granular shape, the angular corners are removed by grinding by friction, the rounded shape is removed, and the protruding parts are removed by grinding by friction. The rounded shape, the cilia-shaped beard is removed by crushing by friction, and the part that is relatively sparse due to the entanglement of cilia-shaped beards is relatively dense by the crushing by friction. By including the outer surface shape in such a state as described above, substantially all of the bulk specific gravity of the wood powder is included.

It is to be noted that the pre-treated wood powder is substantially adjusted in its outer surface shape by the crushing by the frictional action between the crushing balls. Friction grinding breaks the relatively elongated fibrous wood powder into a more granular shape, and angular corners are removed by grinding between grinding balls to give a rounded taste. It has a wavy shape, and the protruding part is removed by crushing due to the frictional action between the crushing balls, and it has a rounded shape, and the ciliary beard is removed by crushing due to the frictional action between the crushing balls. The outer surface shape of the part where the cilia-like mustaches are entangled to make it relatively sparse is made relatively dense by crushing due to the frictional action between the crushing balls. By Erareru, it is intended to include all to increase the bulk specific gravity of substantially wood flour.

The particle size of wood flour obtained by crushing raw wood, pretreated wood flour, and high bulk specific gravity wood flour (Table 2, Table 3, Table 4, Table 5, Table 6) is, for example, While each of these is suspended and dispersed in a prescribed solution, it is individually guided into a transparent channel and allowed to pass through, and by irradiating and transmitting laser light in the channel, the flow direction Indicates the particle diameter obtained by converting the numerical value obtained by measuring the length in to the diameter. Further, the particle size of the raw wood (Table 1) is such that when the raw wood is sieved for 5 minutes using a test vibrating screener (low tap), it passes through a large sieve mesh and a small sieve mesh. The raw wood remaining in No. 2 is indicated by the diameter of the sieve mesh.
It should be noted that here, the particles are not limited to spherical or spherical-like outer shapes, as is clear from the above-mentioned regulation of particle diameter, and most of them have irregular shapes. It is an eggplant.

The average particle size means a particle size of 50 (half amount) weight percent of the cumulative weight percent distribution in the pretreated wood flour and the high bulk specific gravity wood flour.

In this embodiment, the kind of the natural wood which is the raw material to be crushed may be any of commonly used softwoods such as hemlock and lauan, and hardwoods,
Each raw material such as this wood, its chips, or its sawdust is used.

Among the raw materials, the raw material wood 101 such as wood and chips is first subjected to various known mechanical means, for example, a cutter mill or the like, and then various wood materials are used. It is cut and crushed without losing each function, and a large number of raw material materials having a particle size smaller than 1000 μm, preferably raw material materials having a particle size of 500 μm or less are prepared.

The prepared raw material wood 101 is subjected to a required pretreatment, if necessary. This pretreatment is usually carried out in order to bleach a raw material having lignin or tannin, or an undesired pigment or resin content, or to remove unnecessary substances. Process by means.

The raw wood material 101 thus prepared is subjected to a pretreatment as a pretreatment step. First, by using a pulverizer, for example, a fine pulverizer that pulverizes by the action of impact, shearing, grinding or the like, for example, an impeller mill, pulverize each of the raw material woods 101, and similarly in this case,
It is preferable to obtain wood powder having a particle size of about 200 μm or less without losing the various properties and functions of the wood material.

In this case, the wood powder obtained by crushing the raw material wood 101 by the action of impact, shearing, grinding, etc.
As mentioned above, although the original and peculiar characteristics and functions of the wood itself are retained, long wood fibers are included, and the surrounding surface part The fibrous elongated ciliary beard is still derived. Further, the obtained wood powder has many angular portions and protruding portions, is bulky in its entirety, and tends to aggregate with each other.

Here, as the crushing device used for the crushing, for example, an impact blade capable of adjusting the clearance between the crushing chamber and the corrugated liner, in this case, an impact blade protruding in the radial direction of the circumference. An impeller mill configured with a rotor having

By rotating the rotor at a high speed while adjusting the clearance of the impeller mill, the raw material wood 101 is crushed by impact breaking between the corrugated liner and the impact blade, and the impact blade itself also serves as the raw material wood. 10
1 is struck on the corrugated liner surface, similarly crushed and crushed to obtain crushed wood powder.

The crushed wood powder thus crushed is classified at the same time as the crushing or after the crushing, so that the pretreated wood powder 102 has a particle size adjusted according to the purpose of use.

Further, the pretreated wood powder 102 prepared as described above is used for crushing by friction as the next main processing step, and in this embodiment, crushing by friction between the crushing balls. The water content is less than 10 wt%, preferably 8 w, in advance or in the process of the crushing treatment.
It is adjusted by drying so as to be less than t%, more preferably 3 wt% or less.

Here, the drying of the pretreated wood flour 102 is
For the pretreated wood flour 102, the point of effectively giving a surface modification action by crushing by the frictional action between crushing balls, and an object at the time of use, for example, an object such as a plastic product or a paint. When mixed and dispersed in things,
It has a meaning in that it does not adversely affect the object.

The main treatment step performed after the pretreatment step is the pretreated wood flour 102 treated as described above.
On the other hand, the grinding is performed by mechanical means, which is the above-mentioned grinding by friction, and in this embodiment, re-grinding by friction between the grinding balls. A typical means for this mechanical milling process is the dry ball mill shown in FIG. The grinding process by this dry ball mill will be described below.

Pretreated wood powder 10 by this dry ball mill
In the grinding treatment of No. 2, there is a fear that the temperature in the mill will suddenly rise and a violent explosion will occur along with the grinding treatment of the pretreated wood flour 102, and the grinding treatment will be carried out by grinding in a high temperature region. Since the properties and functions originally possessed by the wood flour inside or the wood flour whose bulk specific gravity is increased are impaired, as shown in FIG. 2, the cooling jacket is provided in the peripheral wall of the mill body 1. By forming 2, from the water supply pipe 8 to the drain pipe 9 at all times,
Cooling water is supplied and the temperature inside the mill is at least 80 ° C.
Hereinafter, the temperature is preferably maintained at 70 ° C. or lower.

Inside, there are arranged a stirring bar 4 as a stirring means which is rotationally driven by a motor 5, and a large number of intervening grinding balls 3 which stir and roll by the stirring bar 4 to generate a grinding action. Then, the pretreated wood flour 102 is put into the system from above and opened to operate, and after the process is completed, it can be taken out from the take-out valve 6 through the take-out port 7 to the outside. It

In this case, as the crushing ball 3 for obtaining the above-mentioned grinding action, a ceramic ball having a diameter of 3 mm to 15 mm is used, and the use of a stainless ball which may cause an explosion is avoided. Is preferred.

In the dry ball mill having the above construction, however, the pretreated wood powder 102 fed into the mill is milled between the crushed balls 3 which are agitated and rolled to form a long fiber form. The pre-treated wood powder 102 is broken and crushed by friction so that the pre-treated wood powder 102 is made more granular.
The angular parts, protruding parts, and cilia-shaped beard parts are removed or deformed to adjust the whole to a shape closer to a grain, and between these crushing balls 3 or Due to the frictional heat generated between each crushing ball 3 and the pretreated wood flour 102, the crushed balls 3 are rapidly heated to the required temperature to remove the water contained therein,
Moreover, by continuing the milling, it is dried up to about 3 wt% to 5 wt%.

In this way, the pretreated wood flour 102 is crushed by the frictional action between the crushing balls,
Its outer surface shape is substantially adjusted to have a large bulk specific gravity,
So-called high bulk specific gravity wood flour 103 is obtained.

Further, instead of the open type dry ball mill having the above-mentioned structure, as shown in FIG. 3, a closed type dry type ball mill having a sealing lid 10, an exhaust pipe 11 and an air supply pipe 12 is arranged. A ball mill can also be used.

In the grinding treatment of the pretreated wood powder 102 using this closed type dry ball mill, the oxygen concentration in the mill is adjusted to 15
%, And the temperature inside the mill is preferably set to 80 ° C. or lower. In this mill, after the crushing chamber in the mill is closed by the sealing lid 10, the crushing chamber in the crushing chamber is closed by using the exhaust pipe 11 and the air supply pipe 12. The atmosphere is replaced with an inert gas, for example, nitrogen gas, or the nitrogen gas is continuously flowed while operating under an inert atmosphere.

Further, as described above, the bulk specific gravity is increased by crushing, that is, crushing by frictional action between the crushing balls, that is, crushing the outer surface shape and giving the whole roundness. In order to classify the wood powder 103, for example, the classifying device shown in FIG. 4 can be used.

This classifying device is a wind-type specific gravity classifier that classifies by true specific gravity, and classifies the high bulk specific gravity wood powder 103 supplied from the arrow Y direction by the motor 14 into the rotor 1.
In order to classify under the balance between the centrifugal force generated by the rotation of 3 and the suction force of vacuum exhaust in the direction of arrow W, and to take out coarse powder that does not satisfy the classification condition in the direction of arrow X. In order to avoid the risk of a burst of fine wood powder inside the equipment, nitrogen gas is continuously supplied into the equipment from the direction of arrow N, and while maintaining the oxygen concentration within the equipment within 15%, Operate in an inert atmosphere.

The high bulk specific gravity wood powder 103 thus obtained having a large bulk specific gravity is slightly smaller than the particle size of the pretreated wood powder 102 before being crushed by the frictional action between the crushing balls. The high bulk specific gravity wood powder 103 having a small average particle diameter is formed, and the bulk specific gravity thereof is larger than that of the pretreated wood powder 102 before the pulverization processing due to the frictional action between the crushing balls. That is, the pre-treated wood powder 102 is a long fiber-shaped pre-treated wood powder 102 recognized before the crushing process due to the frictional action between the crushing balls, and is broken into short fiber-like parts. And the cilia-like mustaches are removed, and the entangled cilia-like sparse parts are smoothed and densified by pressing and grinding between the balls, resulting in a rounded overall shape. The surface density is adjusted to increase the bulk specific gravity.

Here, individual experimental examples in each processing operation for obtaining the high bulk specific gravity wood flour 103 having a large bulk specific gravity and comparative examples thereof will be specifically described. (still,
For better understanding of this experimental example and comparative example,
Objects having the same contents as those in the above-described embodiment will be described by giving the same numbers, for example, raw wood 101, pretreated wood flour 102, and high bulk specific gravity wood flour 103. )

Experimental Example 1. Sawdust of Ezo pine consisting of the particle size distribution of Table 1 obtained by sieving, in this case, raw wood 101 as a raw material,
Impeller mill (model IM made by Seishin Enterprise Co., Ltd.
P-250), the clearance between the impact blade of the crushing rotor and the liner was set to 3 mm, and this was mechanically crushed by the action of impact, shearing, grinding, etc. The treated wood flour 102 was obtained.

[0046]

[Table 1]

[0047]

[Table 2]

The pretreated wood flour 10 thus obtained
For No. 2, this was classified using the wind force type specific gravity classifier (PS separator manufactured by Powtech Co., Ltd.) shown in FIG. 4 to obtain the pretreated wood flour 102 having the particle size distribution shown in Table 3 and then further classified. Pretreated wood flour 102 has a diameter of 3
mm zirconia-based ceramic crushed balls 2.
A dry ball mill (Attritor A-200 manufactured by Mitsui Miike Kakoki Co., Ltd.) equipped with a stirring bar having a capacity of 5.4 liters loaded with 4 liters was used, and this was crushed by friction for 2 hours, that is, ground, Table 4 with increased specific gravity
High bulk density wood flour 103 having a particle size distribution of

[0049]

[Table 3]

[0050]

[Table 4]

The high bulk specific gravity wood flour 103 having the particle size distribution shown in Table 4 is
The average particle size of the pretreated wood flour 102 has the particle size distribution shown in Table 3.
It was confirmed that the particle size was slightly reduced, and the bulk specific gravity was increased, almost in Japan.

That is, the pretreated wood flour 10 shown in Table 3
2, the loose bulk specific gravity was 0.126 g / cc and the solid bulk specific gravity was 0.286 g / cc, while the high bulk specific gravity wood flour 103 shown in Table 4 Loose bulk density is 0.186 g / cc, solid bulk density is 0.46
It was 3 g / cc, and it was confirmed that the bulk specific gravity of the wood powder was remarkably increased by the pulverization treatment by the frictional action between the pulverization balls of the ball mill.

The loose bulk specific gravity here is 100.
The pretreated wood flour 102 or high bulk specific gravity wood flour 1 in a cc container
No. 03 was sprinkled with a 24 mesh sieve to form a heap in the container, which was scraped off, and the total weight of each wood flour in the container was divided by 100.
Further, the bulk specific gravity of the solid is sprinkled by sieving the pretreated wood flour 102 or the high bulk specific gravity wood flour 103 through a 24 mesh sieve in a 100 cc container which is subjected to vertical vibration (tapping vibration), and the vibration When the change in the bulk of each wood powder in the container due to is finished, it is scraped off, and the total weight of each wood powder in this container is divided by 100.

In addition, in the pretreated wood powder 102 before the grinding treatment shown in Table 3, it is found that the dimension on the major axis side is longer than the dimension on the minor axis side. There are a lot of cilia and whiskers,
The high bulk specific gravity wood flour 103 shown in Table 4 has a granular shape as a whole, has a roundness, and has a relatively smooth and dense surface. confirmed.

The thus-obtained high bulk specific gravity wood flour 103 almost never aggregated with each other and had good dispersibility in a solution or the like.

Experimental Example 2. Ezo pine sawdust having the particle size distribution shown in Table 1 above, in this case,
Similar to the previous example, regarding the raw wood 101 as a raw material,
After using the same impeller mill as in Experimental Example 1 and setting the clearance between the impact blade of the crushing rotor rotated at high speed and the liner to 3 mm and crushing this, the pretreated wood flour 102 in Table 2 was obtained. , The crushed pretreated wood flour 102
For the above, a 5.4 liter capacity ball mill (Mitsui Miike Kakoki Co., Ltd. Attritor A-200) loaded with 2.4 liters of zirconia-based ceramic crushing balls having a diameter of 3 mm was used for crushing balls for 2 hours. Grinding by frictional action between particles, that is, grinding to obtain high bulk specific gravity wood powder 103 having a particle size distribution shown in Table 5, and using the wind power specific gravity classifier (PS separator manufactured by Powtec Co., Ltd.) shown in FIG. Then, classification was performed to obtain high bulk specific gravity wood flour 103 having a particle size distribution shown in Table 6.

[0057]

[Table 5]

[0058]

[Table 6]

Also, the high bulk specific gravity wood flour 1 thus obtained
03 is the angular portion of the pretreated wood flour 102,
As a result of observation by micrographs, it was confirmed that protruding parts, cilia-like beard parts, etc. were removed, and the whole had roundness and the surface was relatively smooth and dense. .

Moreover, these high bulk specific gravity wood flours 103 are
They were available in a relatively narrow range of particle sizes, and were excellent in fluidity and dispersibility.

Comparative Example 1. The sawdust of Ezo pine consisting of the particle size distribution shown in Table 1 above is
Using a 5.4 liter capacity ball mill (Mitsui Miike Kakoki Co., Ltd. Attritor A-200) loaded with 2.4 liters of zirconia-based ceramic crushed balls of m,
Grinding, i.e. grinding, by friction between the grinding balls for 2 hours.

In the wood flour thus obtained, the ultrafine powder wood flour portion and the long fiber-like portion are mixed, and 70 wt% or more remains with a particle size close to the original shape and does not necessarily have a granular shape. It was confirmed that not. That is, in comparison with the above-mentioned respective experimental examples in which sawdust of Ezo pine was crushed in advance using an impeller mill to form pretreated wood powder 102, and the bulk specific gravity was increased by means of friction, crushing was performed by directly grinding the sawdust. In the case of carrying out, the pulverization efficiency is extremely low, a large amount of long fiber-like parts remain even after pulverization for a long time, and on the other hand, there is a disadvantage that ultra-fine powdered over-pulverized wood powder is produced.

As is clear from the above Examples and Comparative Examples, in order to obtain a high bulk specific gravity wood flour 103 having good fluidity and good dispersibility in a solvent or the like,
At least crush and classify the raw wood 101 in advance,
By preparing this as the pretreated wood powder 102, it is necessary to perform a pulverization process by the action of friction between the pulverization balls, that is, a grinding process, on the pretreated wood powder 102. Then, the prepared pretreated wood flour 102 is subjected to a grinding treatment, so that the pretreated wood flour 102 has angular portions, protruding portions, cilia-like beard portions, etc. Are sequentially removed by the grinding, and the cilia-like sparsely entangled parts are made relatively dense by the pressure caused by the grinding, and the outer shape is rounded as a whole, and the bulk specific gravity thereof is adjusted. Is a relatively high bulk density wood flour 103.

High bulk specific gravity wood flour 10 thus obtained
No. 3 has a feature that it does not aggregate with each other in the storage process or the handling process, has good dispersibility when used in paints, and is uniformly dispersed in a coating liquid. doing. Further, in this embodiment, the high bulk specific gravity wood flour 103 having such characteristics is formed by subjecting the pretreated wood flour 102 prepared in advance to the above-mentioned grinding, and the characteristics The structure is suitable for providing a certain high bulk specific gravity wood flour 103 easily and in mass production. The high bulk specific gravity wood flour 103 thus constructed can be used as a filler for various plastic products, and can be added to paints and the like, and the high bulk specific gravity wood flour 103 can be pressed to form a board. It can be used for various purposes such as forming.

The high bulk specific gravity wood flours 103 obtained in Experimental Examples 1 and 2 are various solvents or various synthetic resin solutions,
Good dispersibility in paints, coating liquids, sealing agents, plastic materials, etc.
A plastic molding, a film containing 3 evenly,
Suitable for obtaining sheets, films or coatings.

For example, the legs made of ABS resin formed by containing 25 wt% of the high bulk specific gravity wood powder 103 of 16 μm under obtained as described above were hard and the feel of the skin was close to that of natural wood. Further, 15 wt% of the high bulk specific gravity wood powder 103 of 5 μm under obtained above was mixed with vinyl chloride resin to obtain a soft vinyl chloride sheet having a thickness of 2 mm by extrusion molding. The obtained sheet had a soft touch and no stickiness. In the above examples, the high bulk specific gravity wood powder 103 obtained by classification or the like has a relatively small particle size, but when a plastic extruded product, an injection molded product or the like is obtained, the high bulk specific gravity contained therein The particle size of the wood powder 103 is preferably larger, for example, the average particle size is 80
A high bulk specific gravity wood flour 103 of μm or the like is used.

Then, the above-mentioned high bulk specific gravity wood flour 103 is blended with the coating material to be used to bring woody surface characteristics to various articles. As the article to be coated, a plastic molded article, a metal molded article, a wood molded article, and synthetic articles such as synthetic leather can be applied and formed on the surface of all articles. The high bulk specific gravity wood powder 103 used here is suitable for forming a better coating surface as the particle size is smaller, and it is preferable to use wood powder having a large bulk specific gravity. From that point of view, high bulk specific gravity wood flour 103 used in paints
Preferably has a particle size of at least 16 μm and a water content of 5 wt% or less. The mixing ratio needs to be set separately depending on the properties of the paint, the purpose of coating, and the like.

When the high bulk specific gravity wood powder 103 obtained above is used as a sealing agent for wood, it has an excellent sealing effect. After applying the undercoat paint as this sealing agent, After that, by wiping off the applied paint, it is possible to perform an undercoating treatment in a state where the wood grain of the wood stands out clearly,
The high-bulk specific gravity wood flour 103 is effectively attached to the surface other than the grain portion. After such undercoating, the high bulk specific gravity wood flour 1
A matte coating film having a woody texture can be obtained by preparing a top coating composition containing No. 03 and applying it to a wood surface that has been subjected to a sealing treatment with the undercoat coating composition. In the case where wood is treated with a paint containing the high bulk specific gravity wood powder 103 of the above example, particularly when the undercoat paint is applied, the applied paint is wiped off, and the topcoat paint is applied to the wood. Unlike the use of the above-mentioned filling agent, it has a feature that the wood grain part of the wood is clearly raised, and has a feature that it has an excellent effect of filling the wood surface other than the wood grain part.

[0069]

EFFECTS OF THE INVENTION The high bulk specific gravity wood flour 103 according to the present invention is effective in the constitution having the above-mentioned features, in particular, the pretreated wood flour 102 having an angular portion, a protruding portion, a ciliated beard portion, and the like. The high bulk specific gravity wood flour 103 does not agglomerate later in the process of storage and handling and use, since it has been removed into the shape of a rounded external shape as a whole. It has a good dispersibility with respect to the like and is characterized by being uniformly dispersed. As a result, the high bulk specific gravity wood flour 103 is uniformly contained in the obtained plastic molded product, film, sheet or coating film, and it is possible to effectively bring various properties and functions peculiar to wood flour to these products. it can. Further, the raw wood 101 is crushed and classified in advance to prepare the pretreated wood flour 102, and the pretreated wood flour 102 is subjected to a treatment for increasing the bulk specific gravity in a separate step, that is, pulverization by the action of friction. However, the high bulk specific gravity wood powder 103 having a large bulk specific gravity has an advantage of being efficiently and mass-produced.

[Brief description of the drawings]

FIG. 1 shows the formation of pretreated wood flour 102 from raw wood 101 according to an embodiment of the present invention, and the pretreated wood flour 102 is crushed by the action of friction to obtain high bulk specific gravity wood flour 103.
Schematic explanatory diagram that schematically shows each process that forms the

FIG. 2 is a longitudinal sectional front view of a main part showing an outline configuration of an open type dry ball mill according to an example for performing a grinding process by frictional action between grinding balls on pretreated wood powder.

FIG. 3 is the same as the above. A longitudinal sectional front view of essential parts showing a schematic configuration of a closed type dry ball mill according to an example for subjecting pretreated wood powder to a grinding treatment by a frictional action between grinding balls.

[Fig. 4] Same as the above, a longitudinal sectional front view of essential parts showing a schematic configuration of a classifier according to an example for classifying pretreated wood flour and high bulk specific gravity wood flour

[Explanation of symbols]

 101 Raw Wood 102 Pretreated Wood Flour 103 High Bulk Density Wood Flour 1 Mill Main Body 2 Cooling Jacket 3 Grinding Ball 4 Stir Bar 5 Motor 6 Removal Valve 7 Removal Port 8 Water Supply Pipe 9 Drain Pipe 10 Sealing Lid 11 Exhaust Pipe 12 Air Supply Pipe 13 classification rotor 14 motor

Claims (4)

(57) [Claims] 1. A wood powder obtained by classifying at the same time as crushing or by classifying after crushing has an outer surface shape substantially adjusted by crushing by frictional action, and has a bulk specific gravity larger than that of the wood powder. High bulk density wood flour that is characterized by being. 2. A wood powder obtained by classifying at the same time as crushing or by classifying after crushing has an outer surface shape substantially adjusted by crushing by a frictional action between crushing balls,
A high bulk specific gravity wood flour having a bulk specific gravity higher than that of the wood flour. 3. A pretreatment step of pulverizing and classifying at the same time as the pulverizing, or pulverizing and classifying after the pulverizing to obtain wood powder, and the wood powder obtained by the pretreatment step is subjected to frictional action. And a main treatment step of crushing to obtain wood flour having a bulk specific gravity larger than that of the wood flour obtained in the pretreatment step. 4. A pretreatment step of pulverizing and classifying at the same time as the pulverizing, or pulverizing and then classifying after the pulverizing to obtain wood powder; and a wood powder obtained by the pretreatment step, a crushing ball A method for producing high bulk specific gravity wood flour, comprising: a main treatment step of making wood flour having a bulk specific gravity larger than that of the wood flour obtained by the pretreatment step by pulverization by friction between the wood flour.