JP5468229B2 - Water repellent wood and method for producing the same - Google Patents

Description

  The present invention relates to a water-repellent wood and a method for producing the same.

  Wood, which is widely used for building materials, furniture, crafts, and the like, may expand (elongate) and cause dimensional changes due to water absorption, and may cause mold and corrosion.

  Therefore, as a method for reducing the water absorption of wood, Patent Document 1 discloses a method of impregnating wood with a silane coupling agent, and Patent Document 2 discloses a method of impregnating wood with trialkoxysilane.

  In Patent Document 2, regarding the method of impregnating wood with a silane coupling agent, “the organic group has a long chain length and the hydrophobicity of the molecule because it is expected to have an effect on the crosslinkability and water repellency of the organic functional group. Therefore, it is impossible to impregnate the cell walls of wood as in the case of the treatment material composed of the above-mentioned polymer monomer, and the reaction of forming a Si—O bond between the OH group and the alkoxy group of wood is slow. Therefore, it had a problem that the effect as expected could not be exhibited.

  In Patent Document 3, a method of impregnating wood with a hydrolyzable alkoxysilyl group-containing organosilicon compound in a metal alkoxide solution is disclosed. Although Patent Document 3 is not a method for directly reducing the water absorption of wood, hydrolyzing by a sol-gel method using a hydrolyzable alkoxysilyl group-containing organosilicon compound when impregnating wood with metal alkoxide. Alternatively, the metal alkoxide is converted to a flame retardant metal oxide by thermal decomposition followed by polycondensation, and in the process of changing to a metal oxide, the organosilicon compound having water repellency and the metal oxide are chemically treated. It is described that it is possible to prevent the leaching metal oxide from being eluted by the action of water while being bound.

In addition, in Patent Document 3, the distribution location of the hydrolyzable alkoxysilyl group-containing organosilicon compound is not described in detail, but in Non-Patent Document 1 (the author is also the inventor of Patent Document 3), There is a description. That is, when a small amount of this organosilicon compound is added to a sol-gel reaction system using silicon alkoxide, the SiO ₂ gel produced in the cell wall and the organosilicon compound having an alkoxysilyl group at the terminal undergo hydrolysis and Si— O-Si covalent bond occurs. As a specific example, in a system in which an organosilicon compound having a long chain alkyl group (2-heptadecafluorooctylethyltrimethoxysilane) is added to tetraethoxysilane, the SiO ₂ gel is uniformly distributed in the cell wall. On the other hand, since the organosilicon compound residue is located at the interface between the cell wall and the lumen and has a trimethoxysilyl group at the terminal, it chemically bonds with the SiO ₂ gel generated in the cell wall through hydrolysis, It is described that it is fixed on the cell lumen surface and has a large molecular weight of the organosilicon compound and is hydrophobic, which makes it difficult to penetrate into the cell wall and adheres to the cell lumen surface.

In Non-Patent Document 1, when the organosilicon compound is directly reacted with wood, a C—O—Si bond is formed with a hydroxyl group in the wood component, but this bond is unstable and dissociates. It is also described that the active ingredient is leached with time.
JP-A-1-136704 Japanese Patent No. 3196188 Japanese Patent No. 2962191 Shiro Saka, “Durability Performance of Inorganic Composite Wood by Sol-Gel Method”, Wood Preservation, 2000, Vol. 20-3, p. 113-122

  An object of this invention is to provide the water-repellent wood excellent in durability, and its manufacturing method.

The present invention provides a water-repellent wood that contains an organosilane reactant in the cell wall of wood cells that are not exposed on the wood surface, and the organosilane is a compound represented by the following general formula (1) .
R _n SiX _4-n (1)
[Wherein, R represents an organic group having 1 to 18 carbon atoms, X represents a hydrolyzable group, and n represents an integer of 1 to 3, respectively. ]

Such water-repellent wood is much more durable than those described in the above document because the reaction product of organosilane exists even inside the cell walls of wood cells not exposed on the surface. In the present invention, the organosilane reactant is present at least inside the cell wall, but may also be present on the cell wall surface or in the cell lumen. In addition, organosilane having an organic group having up to 18 carbon atoms is easy to use as a vapor, is easily mixed with a carrier gas, and penetrates into the cell wall, so that it becomes a water-repellent wood excellent in water repellency.

  The present invention also provides a water-repellent wood in which a mixed gas of an organosilane vapor and a carrier gas is brought into contact with wood to contain the organosilane reactant inside the wood cell wall.

  Such water-repellent wood is made by contacting wood with a mixed gas of organosilane vapor and carrier gas, so that a reaction product of organosilane is present inside the cell wall, resulting in water repellency and durability. It will be excellent. In addition, as described in the above-mentioned known literature, in a known method of impregnation in a liquid phase (hereinafter sometimes referred to as “liquid phase impregnation method”), organosilane or a reaction product thereof is present inside the cell wall. It has been impossible in the past.

  The water-repellent wood can be produced by a production method comprising a step of bringing a mixed gas of organosilane vapor and carrier gas into contact with the wood to contain an organosilane reactant inside the wood cell wall.

  By this production method, the mixed gas can penetrate into the cell walls of the wood cells, and a water-repellent wood having much superior durability can be obtained as compared with the wood obtained by the liquid phase impregnation method. .

The organosilane is preferably a compound represented by the following general formula (1).
R _n SiX _4-n (1)
[Wherein, R represents an organic group having 1 to 18 carbon atoms, X represents a hydrolyzable group, and n represents an integer of 1 to 3, respectively. ]

  An organosilane having an organic group having up to 18 carbon atoms is easy to use as a vapor, and is easily mixed with a carrier gas and penetrates into the cell wall, so that a water-repellent wood having particularly excellent water repellency can be obtained.

  The carrier gas is preferably water vapor.

  Since the pressure of the mixed gas of the organosilane vapor and the water vapor can be made much higher than the vapor pressure of the organosilane alone, the organosilane can quickly reach the inside of the cell wall of the wood. Organosilanes may initiate hydrolysis by contact with water vapor and come into contact with the cell wall as a highly reactive intermediate, and rapidly hydrolyze and condense with hydroxyl groups such as cellulose that constitute the cell wall. Since the reaction occurs, the organosilane reactant is rapidly and reliably formed inside the cell wall.

  The temperature of the mixed gas is preferably 60 to 240 ° C.

  When the mixed gas in the above temperature range comes into contact with the wood, the water-repellent wood can be produced in a shorter time.

  The organosilane may be a mixture of at least one organosilane having an alkyl group having 1 to 4 carbon atoms and at least one organosilane having an alkyl group having 6 to 18 carbon atoms.

  Water repellency performance is high, but water repellency performance is high by mixing organosilane having long chain alkyl group with low vapor pressure and water repellency performance. Organosilane having a long-chain alkyl group can penetrate into the wood.

  Since a water-repellent wood particularly excellent in durability can be obtained, the amount of organosilane introduced is preferably 0.1 to 40.0% by weight based on the absolute dry weight of the wood to be contacted.

  The present invention provides a water-repellent wood that exhibits excellent water repellency from the wood surface to the inside and a method for producing the water-repellent wood.

  Hereinafter, preferred embodiments will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the drawings are exaggerated for easy understanding, and the dimensional ratios do not necessarily match those described.

  Fig.1 (a) is a perspective view of the water-repellent wood which concerns on embodiment, (b) is II sectional drawing of Fig.1 (a). FIG. 2 is an enlarged schematic view of a portion represented by A in FIG.

  The water repellent wood 100 shown in FIG. 1 (a) has a rectangular parallelepiped shape, and its II cross section is rectangular as shown in FIG. 1 (b). FIG. 2 is an enlarged view of the region A including the outer surface of the water-repellent wood 100 in FIG. 1B, and schematically shows wood cells. In FIG. 2, the wood cells (for example, wood cells 2a) existing in the region represented by x are exposed on the wood surface 4, and the wood cells (for example, wood cells 2b) present in the region represented by y are exposed. Is unexposed that is not exposed on the wood surface 4. Here, the actual cell has a passage (pit) (not shown) that communicates the cells, and plays a role of a flow path of sap and water. Sap and water enter the cell lumen through this passage (pit).

  The cell wall 6 in the wood cell is composed of cellulose, hemicellulose, lignin or the like, and generally has a multilayer structure such as a primary wall or a secondary wall. In the water-repellent wood 100, the organosilane reactant is contained in the cell wall 6 of the unexposed cell (for example, the wood cell 2b) on the wood surface 4 (the organosilane reactant is contained in the wood cell 2b). The contained region is indicated by hatching.) The reaction product preferably reacts with a hydroxyl group such as cellulose constituting the cell wall 6 to bind to the cell wall 6 inside the cell wall 6. Here, examples of the reaction product of organosilane include a hydrolyzate of organosilane and a condensate of the hydrolyzate, and the reaction product preferably has an organosiloxy skeleton. In the water-repellent wood 100, the organosilane reactant is present at least in the cell wall 6, but may be present in the cell wall surface 8 and the cell lumen 10 at the same time.

The water-repellent wood 100 can be obtained by using, for example, a mixed gas of organosilane vapor and carrier gas, as described in detail below. The organosilane used is, for example, an organosilicon compound having a basic structure of R _n SiX _4-n (n = 1, 2, 3). R represents an organic group such as an alkyl group or a fluoroalkyl group, X represents a hydrolyzable group such as a halogen group or an alkoxyl group, and n represents the number of organic functional groups. Here, when the organosilane has two or more organic groups (n = 2, 3), these organic groups may be the same or different. Similarly, when the organosilane has two or more X (n = 1, 2), X may be the same or different.

  Examples of the organic group in the organosilane include an alkyl group, a halogenoalkyl group, an aryl group, a halogenoaryl group, an aralkyl group, and a halogenoaralkyl group. From the viewpoint of water repellency, an alkyl group and a halogenoalkyl group are preferable. Here, as “halogeno”, fluoro, chloro and bromo are preferable, and fluoro is more preferable.

  When the organic group is an alkyl group, examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group. In general, an alkyl group is a long chain. Therefore, a methyl group, an ethyl group, a propyl group, and a butyl group are preferable because the hydrolysis reaction is not only slowed but also remains in the wood after the treatment and may cause a combustible component.

  Examples of the hydrolyzable group in the organosilane include a halogen atom, an alkoxy group, an acyloxy group, an alkenyloxy group, an amino group, a mercapto group, a ketoximate group, an aminooxy group and a carbamoyl group. An atom and an alkoxy group are preferable.

  Preferred as the organosilane are organochlorosilane, organoalkoxysilane, fluoroalkylchlorosilane, and fluoroalkylalkoxysilane, and among them, organoalkoxysilane is preferable.

  As the organochlorosilane, alkylchlorosilane is preferable. Examples of alkylchlorosilanes include methylchlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, triethylchlorosilane, trioctadecylchlorosilane, phenylchlorosilanes such as triphenylchlorosilane, diphenyldichlorosilane, and phenyltrichlorosilane, or fluoroalkylchlorosilanes. Can be mentioned.

  Examples of the fluoroalkylchlorosilane include 1H, 1H, 2H, 2H-perfluoropropyltrichlorosilane, 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane, 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane, 1H , 1H, 2H, 2H-perfluorodecylmethyldichlorosilane, 1H, 1H, 2H, 2H-perfluorodecyldimethylchlorosilane, etc., and as the fluoroalkylalkoxysilane, 1H, 1H, 2H, 2H-perfluoropropyl Trimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecylmethyldimethoxysilane 1H, 1H, 2H, 2H- perfluoro decyl dimethyl silane and the like can be exemplified.

  As the organoalkoxysilane, alkylalkoxysilane is preferable, and alkyltrialkoxysilane (n = 1) is particularly preferable. Examples of the alkyltrialkoxysilane include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethoxysilane, methyl Triethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, pentyltriethoxysilane, hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, un Decyltrimethoxysilane, dodecyltrimethoxysilane, decyltrimethoxysilane, tetradecyltrimethoxysilane, pentadecyltri Toxisilane, hexadecyltrimethoxysilane, heptadecyltrimethoxysilane, octadecyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, undecyltrimethoxysilane, dodecyltrimethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, Examples include tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane, and octadecyltriethoxysilane.

  Since the water-repellent wood is preferably manufactured using organosilane as a vapor, it is difficult to apply organosilane that does not vaporize. From such a viewpoint, the carbon number of the organic group (R) in the organosilane is also affected by the hydrolyzable group (X), but 1 to 18 is preferable.

  The method for producing water-repellent wood described above includes a step of bringing a mixed gas of an organosilane vapor and a carrier gas into contact with the wood and including the reaction product of the organosilane in the cell wall of the wood. Can be mentioned.

  Examples of the carrier gas include water vapor, alcohol vapor, halogen gas, nitrogen gas and the like, but water vapor is preferable from the viewpoint of not only reactivity but versatility, economy and safety. The mixed gas of organosilane vapor and carrier gas is preferably generated in a chamber capable of being heated and pressurized, and an autoclave is an example of such a chamber.

  The method of forming at least one kind of organosilane vapor and water vapor mixed gas in the autoclave is not particularly limited. For example, at least one kind of organosilane formed in advance in another container, piping, or the like. A method of injecting a mixed gas of silane vapor and water vapor into the autoclave, a method of injecting water vapor into the autoclave in a state where at least one organosilane is present in the autoclave, at least one organosilane and water in the autoclave There are a method in which the autoclave is heated by an external heat source in a state in which at least one organosilane vapor and water vapor are separately injected into the autoclave.

  As a method of forming a mixed gas of at least one kind of organosilane vapor and water vapor in another container or piping in advance, for example, water vapor is injected in a state where at least one kind of organosilane exists in another container. The organosilane can be vaporized by a plunger pump or the like through a vaporizing nozzle or the like through a vaporizing nozzle or the like from a method for vaporizing organosilane by vaporizing organosilane or injecting steam into the autoclave into the autoclave. There is a method of press-fitting directly into the steam pipe. Here, the organosilane to be injected may be in any state such as liquid, mist, and vapor, and when injected with the liquid or mist, it is vaporized in a high-temperature and high-pressure steam pipe.

  Examples of the method of placing at least one organosilane in the autoclave in advance include, for example, a method in which the organosilane is directly placed in the autoclave, a method in which the organosilane is placed in an unsealed open container, and automatic opening / closing. There is a method in which organosilane is placed in a sealed container that can be opened and the sealed container is opened. When placing organosilane in a sealed container that can be opened and closed automatically, not only before opening the steam, but also opening the sealed container at any time during the steam injection. It doesn't matter.

  Further, in the method of heating the autoclave with an external heat source in a state where at least one organosilane and water are present in the autoclave, as a method of putting the organosilane and water in the autoclave, for example, in the autoclave In this method, the organosilane and water are placed directly in the container, each is placed in a separate open container, the water is placed in an open container, and the organosilane is placed in a sealed container that can be opened and closed automatically. There is a method of opening the sealed container at the timing of. Here, the heat source from the outside is not particularly limited, but includes electricity, gas, heavy oil, light oil, water vapor and the like.

When using two or more kinds of organosilane organosilane, even by stone as a mixed gas of water vapor by vaporizing a mixed solution obtained by mixing beforehand two or more organosilanes, each vaporized separately each steam It may be a mixed gas.

  In the method of evaporating and vaporizing organosilane using water vapor, not only the water vapor becomes a heat source for vaporizing organosilane, but also the pressure of the resulting mixed gas of organosilane vapor and water vapor is the vapor pressure of organosilane alone. Because it becomes very high compared to, it can reach the inside of the wood quickly. In addition, if steam is used, it will not only become a heat source for heating wood, autoclave bodies, pipes, etc., but even if organosilane vapor condenses to a liquid at a place other than wood, it will be evaporated again due to the heat of water vapor. Therefore, organosilane can not only be used efficiently and efficiently reach the inside of the wood, but also to accelerate the reaction between the organosilane and the wood, the organosilane quickly bonds chemically with the wood, and the water repellent layer is formed. Form. If necessary, the autoclave may be preheated or auxiliary heated using an external heat source.

  Pressure difference before and after contacting the mixed gas when wood is treated with a mixed gas of organosilane vapor and water vapor at high temperature and high pressure, that is, when mixed gas of organosilane vapor and water vapor is contacted with wood at high temperature and high pressure Is preferably 0.02 to 3.0 MPa, more preferably 0.05 to 2.0 MPa, and still more preferably 0.1 to 1.5 MPa. The temperature at which the mixed gas is brought into contact is preferably 60 to 240 ° C, more preferably 80 to 215 ° C, and particularly preferably 100 to 200 ° C. Moreover, it is a preferable aspect to remove the air in the autoclave with a vacuum pump or the like before treating the wood with a mixed gas of organosilane vapor and water vapor.

  Here, the penetration of the organosilane into the wood is caused by the large pressure difference when the mixed gas of organosilane vapor and water vapor is brought to high temperature and high pressure in the autoclave. Even types of organosilanes can penetrate into wood quickly and reliably. In addition, water repellency performance is high by mixing organosilanes with long-chain alkyl groups with high water repellency but low vapor pressure and organosilanes with alkyl groups with high water pressure but slightly poor water repellency. Such a mixture of organosilanes is a preferred embodiment because it enables the organosilane having a long, long-chain alkyl group to penetrate into the wood. Specific examples of combinations of organosilanes include a mixture of at least one organosilane having an alkyl group having 1 to 4 carbon atoms and at least one organosilane having an alkyl group having 6 to 18 carbon atoms. It is done.

  The time for treating the wood with a mixed gas containing high-temperature and high-pressure organosilane vapor and water vapor may be 0.5 to 5 hours. If some unreacted organosilane is present and water repellency is not sufficiently developed, leave it for several days to several weeks at room temperature to react with unreacted organosilane and wood to develop water repellency. However, it is preferable to heat at 60 ° C. to 180 ° C. for about 0.5 to 5 hours. Here, the heating method is not particularly limited, and general hot air heating, far-infrared heating, steam heating, or the like can be used.

  The amount of organosilane for expressing sufficient water repellency is preferably 0.1 to 40.0% by weight, more preferably 0.5 to 20.0% by weight, based on the absolute dry weight of the wood to be treated. Furthermore, 1.0 to 10.0% by weight is particularly preferable.

  The reason why organosilane produces excellent water repellency with high durability is not necessarily clear, but the following factors are presumed. In other words, the penetration of organosilane into the wood is a gas with high molecular mobility, and the pressure difference, not diffusion, is the driving force. Since the organosilane has a high temperature, the reaction is accelerated and the hydrolyzable group of the organosilane is hydrolyzed to produce a silanol group (Si-OH group) and a wood hydroxyl group ( OH group) reacts rapidly and not only forms Si—O—C bonds, but also organosilanes self-condensate to form a three-dimensional network structure. The It is presumed that this network structure immobilizes organosilane on the cell surface and inside the cell and provides water repellency with extremely high durability.

  The wood used in the present invention is not particularly limited, and examples thereof include logs, lumber products, sliced veneers, and plywood, and may be dried products or wet products (saturated products).

Hereinafter, the present invention will be described in more detail with reference to examples.
In this example, the amount of organosilane permeation and water repellency, the weight increase rate of organosilane serving as an index of the network structure of organosilane and wood, the contact angle of water, and the organosilane elution rate were measured as follows.

<Rate of increase in organosilane weight>
The amount of organo penetration into wood is determined from the weight increase rate before and after treatment. Specifically, the weight increase rate due to organosilane is the absolute dry weight before treatment in which wood of the same size and material is dried at 105 ° C. for 24 hours. For (W ₀ ), after treatment with a mixed gas of organosilane vapor and water vapor, drying at 105 ° C. for 24 hours, and further vacuum drying at 40 ° C. for 24 hours, the absolute dry weight (W ₁ ) Obtained by the formula.
Weight increase rate = {(W ₁ −W ₀ ) / W ₀ } × 100 [% by weight]

<Water contact angle>
A wood sample having a length of 40 mm, a width of 40 mm, and a length of 200 mm was cut at a position of 100 mm in length, and a total of 16 points at 10 mm intervals in the vertical direction and the horizontal direction on a 40 mm square cut surface at a temperature of 20 ° C. It measured with the contact angle meter (CA-DT type | mold) by Kyowa Interface Science Co., Ltd. on the conditions of 65% of humidity.

<Elution rate of organosilane>
After the treatment with a mixed gas of organosilane vapor and water vapor, the weight (M ₀ ) of the treated wood after drying at 105 ° C. for 24 hours and further vacuum dried at 40 ° C. for 24 hours is measured. (Distilled water) or toluene at a rate of 10 g, and after stirring for 8 hours and 24 hours, the treated wood is taken out, dried at 105 ° C. for 24 hours, and then vacuum dried at 40 ° C. for 24 hours to obtain the weight (M ₁ ). It measured and the elution rate was calculated | required from following Formula.
Dissolution rate = {(M ₀ −M ₁ ) / (W ₁ −W ₀ )} × 100 [% by weight]

<Identification of organosilane>
A wood sample treated with a mixed gas of organosilane vapor and water vapor is an electron microscope (JSM-6060-LV) equipped with an energy dispersive X-ray analyzer (JED-2300) manufactured by JEOL Ltd. (JEOL). The location of the organosilane reactant was identified from the SEM photograph of the cell wall cross section of the wood and the mapping image of silicon (Si) by the KαX ray of the cell wall cross section.

[Example 1]
Ten cedars and spruce each having a length of 40 mm, a width of 40 mm, and a length of 200 mm are placed in an autoclave having a volume of 1.25 m ³ that has been heated to 150 ° C., and then the pressure in the autoclave is reduced to a gauge pressure of −0.095 MPa. Then, a mixed steam formed by press-fitting 1 kg of methyltriethoxysilane in a mist form with a plunger pump through a steam nozzle into a steam pipe having a gauge pressure of 1.5 MPa was injected to a gauge pressure of 1.0 MPa. Thereafter, in order to maintain the pressure, only water vapor was injected, and the gauge pressure was maintained at 1.0 MPa for 3 hours. Here, all the used wood was a dried product at 60 ° C. for 3 days.

  The percentage of increase in the weight of organosilane obtained by Example 1 in terms of the five-point average of organosilane was 8.2% by weight for spruce and 8.5% by weight for cedar. The water contact angles were 78-85 ° for spruce and 75-83 ° for cedar. The elution rate after 24 hours was 1.1% by weight for water of spruce, 2.1% by weight for toluene, 0.9% by weight for cedar and 1.8% by weight for toluene. From these results, it was confirmed that methyltriethoxysilane permeated into each of the timbers, thereby exhibiting water repellency with excellent durability. Moreover, from the SEM photograph (FIG. 3) of the cell wall cross section of the spruce obtained in Example 1 and the mapping image (FIG. 4) of the silicon (Si) of the cell wall cross section, it is derived from the methyltriethoxysilane reactant in the cell wall. As a result, the existence of silicon, which was presumed, was confirmed. In addition, the presence of silicon, which is presumed to be derived from the methyltriethoxysilane reactant, was also confirmed in the cell wall cross section of cedar by the same method.

[Example 2]
Ten cedars and spruce each having a length of 40 mm, a width of 40 mm, and a length of 200 mm were placed in an autoclave with a volume of 1.25 m ³ that had been heated to 150 ° C. in advance, and the autoclave was decompressed to a gauge pressure of −0.095 MPa. After putting 0.5 kg of propyltriethoxysilane in another pressure vessel having a volume of 0.312 m ³ and reducing the pressure to a gauge pressure of −0.095 MPa, water vapor was injected to form a mixed gas formed at a gauge pressure of 1.2 MPa. The autoclave was poured up to a gauge pressure of 0.5 MPa. Then, in order to maintain a pressure, only water vapor | steam was inject | poured and it hold | maintained for 1 hour with the gauge pressure of 0.5 MPa. Here, all the used wood was a dried product at 60 ° C. for 3 days.

  The percentage of increase in the weight of organosilane averaged by 5 points obtained in Example 2 was 5.1% by weight for spruce and 4.5% by weight for cedar. The water contact angles were 88-95 ° for spruce and 85-96 ° for cedar. The elution rate after 24 hours was 0.9% by weight for spruce water, 1.5% by weight for toluene, 1.0% by weight for cedar water, and 1.4% by weight for toluene. From these results, it was confirmed that propyltriethoxysilane permeated into each of the timbers and exhibited water repellency with excellent durability. Further, from the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, the presence of silicon presumed to be derived from the propyltriethoxysilane reactant was confirmed in the spruce and cedar cell wall cross sections.

[Example 3]
Two cedars and spruce each having a length of 40 mm, a width of 40 mm, and a length of 200 mm, and 0.2 kg of isobutytriethoxysilane and 2 kg of water placed in separate open containers are placed in an autoclave having a volume of 0.02 m ³ , After reducing the pressure inside the autoclave to a gauge pressure of -0.095 MPa, the autoclave was heated to a gauge pressure of 1.5 MPa with an electric heater provided in the autoclave and kept in that state for 1 hour. Here, all the used wood was a dried product at 60 ° C. for 3 days.

  The rate of increase in the organosilane weight of the wood obtained in Example 3 was 3.2% by weight for spruce and 2.8% by weight for cedar. The water contact angles were 98-110 ° for spruce and 105-112 ° for cedar. The elution rate after 24 hours was 0.8% by weight for water of spruce, 1.4% by weight for toluene, 0.8% for cedar by water, and 1.4% by weight for toluene. From these results, it was confirmed that isobutyltriethoxysilane permeated into each of the timbers and exhibited water repellency with excellent durability. In addition, from the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, the presence of silicon presumed to be derived from the isobutytriethoxysilane reactant was confirmed in the cell wall cross section of spruce and cedar. .

[Example 4]
Ten cedars and spruce each having a length of 40 mm, a width of 40 mm, and a length of 200 mm were placed in an autoclave with a volume of 1.25 m ³ that had been heated to 150 ° C. in advance, and the autoclave was decompressed to a gauge pressure of −0.095 MPa. A mixed gas formed by injecting 0.3 kg of hexyltriethoxysilane in a mist form with a plunger pump into a steam pipe having a gauge pressure of 1.5 Mpa through a steam nozzle to a gauge pressure of 0.005 MPa, Only, and a gauge pressure of 1.0 MPa was maintained for 3 hours. Here, all the used wood was a dried product at 60 ° C. for 3 days.

  The rate of increase in the organosilane weight of the wood obtained in Example 4 was 1.5% by weight for spruce and 1.7% by weight for cedar. The contact angle of water was 125 to 132 ° for spruce and 130 to 135 ° for cedar. The elution rate after 24 hours was 0.4% by weight for water of spruce, 0.9% by weight for toluene, 0.4% by weight for cedar and 1.0% by weight for toluene. From these results, it was confirmed that hexyltriethoxysilane permeated into each of the timbers and exhibited water repellency with excellent durability. Further, from the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, the presence of silicon presumed to be derived from the hexyltriethoxysilane reactant was confirmed in the cell wall cross sections of spruce and cedar.

[Example 5]
The treatment was performed in the same manner as in Example 4 except that 0.3 kg of octyltriethoxysilane was used.

  The percentages of increase in the weight of organosilane in the wood obtained in Example 5 were 1.4% by weight for spruce and 1.3% by weight for cedar. The contact angles of water were 130 to 138 ° for spruce and 129 to 138 ° for cedar. The elution rate after 24 hours was 0.3% by weight for water of spruce, 0.8% by weight for toluene, 0.3% for cedar by water, and 0.7% by weight for toluene. From these results, it was confirmed that octyltriethoxysilane permeated into each of the woods, and exhibited water repellency with excellent durability. Further, from the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, the presence of silicon presumed to be derived from the octyltriethoxysilane reactant in the cell wall cross section of spruce and cedar was confirmed.

[Example 6]
The treatment was performed in the same manner as in Example 4 except that a mixture of 0.2 kg of propyltriethoxysilane and 0.1 kg of octyltriethoxysilane was used.

  The rate of increase in the organosilane weight of the wood obtained in Example 6 was 1.7% by weight for spruce and 1.5% by weight for cedar. The contact angles of water were 135 to 142 ° for spruce and 138 to 142 ° for cedar. The elution rate after 24 hours was 0.2% by weight for water of spruce, 0.5% by weight for toluene, 0.2% by weight for cedar and 0.6% by weight for toluene. From these results, it was confirmed that propyltriethoxysilane and octyltriethoxysilane permeated into the wood, respectively, and exhibited water repellency with excellent durability. In addition, from the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, the cell wall cross section of spruce and cedar is assumed to be derived from the reaction product of propyltriethoxysilane and octyltriethoxysilane. Existence was confirmed.

[Example 7]
The treatment was performed in the same manner as in Example 4 except that a mixture of 0.25 kg of propyltriethoxysilane and 0.05 kg of octadecyltriethoxysilane was used.

  The percentage of increase in the organosilane weight of the wood obtained in Example 7 was 1.6% by weight for spruce and 1.7% by weight for cedar. The contact angle of water was 150 ° or more at all 16 points of spruce and cedar. The elution rate after 24 hours was 0.2% by weight for water of spruce, 0.3% by weight for toluene, 0.1% by weight for cedar and 0.3% by weight for toluene. From these results, it was confirmed that propyltriethoxysilane and octadecyltriethoxysilane permeated into the wood, respectively, and exhibited water repellency with excellent durability. Moreover, from the SEM photograph of the cell wall cross section and the mapping image of silicon (Si) of the cell wall cross section, the cell wall cross section of spruce and cedar is assumed to be derived from the reaction product of propyltriethoxysilane and octadecyltriethoxysilane. Existence was confirmed.

[Example 8]
The treatment was performed in the same manner as in Example 4 except that a mixture of 0.25 kg of propyltriethoxysilane and 0.05 kg of trifluoropropyltrimethoxysilane was used.

  The percentage of increase in the organosilane weight of the wood obtained in Example 8 was 1.5% by weight for spruce and 1.7% by weight for cedar. The contact angle of water was 150 ° or more at all 16 points of spruce and cedar. The elution rate after 24 hours was 0.1% by weight for water of spruce, 0.2% by weight for toluene, 0.2% by weight for cedar and 0.3% by weight for toluene. From these results, it was confirmed that propyltriethoxysilane and trifluoropropyltrimethoxysilane permeated into the wood, respectively, and exhibited water repellency with excellent durability. From the SEM photograph of the cell wall cross section and the silicon (Si) mapping image of the cell wall cross section, it is assumed that the cell wall cross section of spruce and cedar is derived from the reaction product of propyltriethoxysilane and trifluoropropyltrimethoxysilane. The presence of silicon was confirmed.

  As in the above examples, organosilane penetration amount and water repellency, organosilane weight increase rate, water contact angle, organosilane elution rate, which are indicators of the network structure of organosilane and wood, are excellent and excellent in durability. The water repellent performance was exhibited and the effectiveness of the present invention could be demonstrated.

(A) is a perspective view of the water repellent wood which concerns on embodiment, (b) is II sectional drawing of (a). It is the schematic diagram which expanded the part represented by A of FIG.1 (b). It is a SEM photograph of the cell section of spruce processed with the mixed gas of organosilane vapor and water vapor. FIG. 4 is a silicon (Si) mapping image of the same cell cross section as FIG. 3.

Explanation of symbols

2a, 2b ... wood cells, 4 ... wood surface, 6 ... cell wall, 8 ... cell wall surface, 10 ... cell lumen, 100 ... water-repellent wood.

Claims (9)

Containing reactant organosilane inside cell walls of the wood cells unexposed to the wood surface,
Water-repellent wood , wherein the organosilane is a compound represented by the following general formula (1) .
R _n SiX _4-n (1)
[Wherein, R represents an organic group having 1 to 18 carbon atoms, X represents a hydrolyzable group, and n represents an integer of 1 to 3, respectively. ] A mixed gas of vapor of the organosilane and the carrier gas is contacted with the wood, it was contained reactants Oh Ruganoshiran inside the cell wall of wood, water-repellent wood. The water-repellent wood according to claim 2 , wherein the organosilane is a compound represented by the following general formula (1).
R _n SiX _4-n (1)
[Wherein, R represents an organic group having 1 to 18 carbon atoms, X represents a hydrolyzable group, and n represents an integer of 1 to 3, respectively. ] A mixed gas of vapor of the organosilane and the carrier gas is contacted with the wood, comprising the step of containing the reaction product of o Ruganoshiran inside cell walls of the wood, the production method of the water-repellent timber. The manufacturing method of Claim 4 whose said organosilane is a compound represented by following General formula (1).
R _n SiX _4-n (1)
[Wherein, R represents an organic group having 1 to 18 carbon atoms, X represents a hydrolyzable group, and n represents an integer of 1 to 3, respectively. ]   The production method according to claim 4 or 5, wherein the carrier gas is water vapor.   The manufacturing method as described in any one of Claims 4-6 whose temperature of the said mixed gas made to contact with the said wood is 60-240 degreeC.   The organosilane is a mixture of at least one organosilane having an alkyl group having 1 to 4 carbon atoms and at least one organosilane having an alkyl group having 6 to 18 carbon atoms. The manufacturing method as described in any one of these.   The manufacturing method as described in any one of Claims 4-8 whose weight of the said organosilane is 0.1-40.0 weight% with respect to the absolute dry weight of the wood to contact.