JPH0482708A - Production of modified wood - Google Patents

Abstract

PURPOSE:To make a wood have dimensional stability throughout, little odor of residual unreacted chemicals and excellent antiseptic and moth-proof proper ties and retain a wood feeling on the surface thereof, by impregnating a raw material wood with a specified organic compound, and forming and fixing an insloluble hardened resin in the texture of the wood. CONSTITUTION:A metal salt of acrylic or methacrylic acid and a polyalkylene glycol are infiltrated into a raw material wood in the state of being dissolved in water, and then an insoluble hardened resin is formed and fixed in the texture of the wood. The polyalkylene glycol is a polyalkylene glycol acrylate and/or a polyalkylene glycol methacrylate. The formation and fixation of the insoluble hardened resin in the texture of the raw material wood is carried out by prelimi narily impregnating also a radical polymerization initiator and heating. The resin is thereby formed and fixed in the wood texture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing modified wood used for housing equipment, building materials, etc.

[Conventional technology]

Conventionally, methods for imparting dimensional stability to wood include, for example, the following methods (1) to (2).

■ After impregnating the wood with acetic anhydride and a catalyst such as potassium acetate, by heating it at 100 to 130°C,
A method of replacing the hydroxyl groups of wood cellulose with acetyl groups (acetylation). According to this method, the hydrophilic hydroxyl groups of wood cellulose are replaced with hydrophobic acetyl groups, so
As a result of the reduced hygroscopic (water) property of the wood, dimensional changes in the wood are reduced.

■ A method of producing resin in wood by impregnating it with a monomer such as styrene or methyl methacrylate and then heating or irradiating it with electron beams (WPC manufacturing method). According to this method, in addition to improving dimensional stability, hardness and wear resistance are also improved.

■ A method of imparting high dimensional stability by impregnating wood with a resin having an isocyanate group or an epoxy group and reacting the resin with the wood [Problem to be solved by the invention] However, methods of The method is as follows (a) respectively.
There was the problem of ~(C).

(al) In the method ① above, it is difficult to completely acetylate the cellulose inside the wood, so it is not possible to stabilize the dimensions of the inside of the wood.Also, a sufficient acetylation rate cannot be obtained, and unreacted Since acetic acid remains in the wood, the odor of acetic acid is emitted, and the acetic acid destroys the wood weave, reducing the strength of the wood.

(bl) In the above method, the monomer impregnated into the wood is hydrophobic, so the monomers are not impregnated into the cell walls of the wood. Therefore, in order to impart high dimensional stability, it is necessary to It is necessary to impregnate the wood with a large amount of monomer, as much as 50 to 100% by weight.As a result, the wood surface loses its woody feel.

fc) In method (2) above, there is a possibility that the resin impregnated into wood and reacted with wood components may harden, and if the resin hardens, the wood structure may be destroyed due to the large degree of curing shrinkage. As a result, swelling occurs more than in untreated wood, resulting in reduced dimensional stability.

In view of these circumstances, the present invention has developed modified wood that is dimensionally stable to the inside of the wood, has little residual odor from unreacted chemicals, does not destroy the wood structure, and does not lose its surface wood texture. Our goal is to provide a method that can be obtained efficiently.

[Means to solve the problem]

In order to solve the above problems, the method for producing modified wood according to the present invention includes adding at least one kind of acrylic acid metal salts and methacrylic acid metal salts and at least one kind of polyalkylene gelicols to water. After it is impregnated into raw material wood in a dissolved state, insoluble hardened Wi-4 fat is produced and fixed within the structure of the wood.

The raw material wood used in this invention is not particularly limited, and includes, for example, raw wood logs, sawn timber products, sliced veneers, rotary veneers, plywood, and the like. There are no limitations on the tree species, etc.

The acrylic acid metal salts used in this invention are not particularly limited, but include, for example, those in which hydrogen in the carboxyl group of acrylic acid is replaced with a metal as exemplified later. The metal is not particularly limited, but preferably has a valence of 2 to 6. Specific examples include magnesium, calcium, barium, iron, nickel, cobalt, copper, zinc, and aluminum. Depending on the type of these metals, it is also possible to improve the flame retardance, wear resistance, surface hardness, etc. of wood. Such acrylic acid metal salts may be used alone or in combination. Furthermore, since acrylic acid metal salts generally have weak toxicity, they also have the effect of imparting antiseptic and insect repellent properties to wood. The acrylic acid metal salts are
For example, when a metal has a valence of 2 to 6, it forms a dimer to a hexamer depending on the valence, and is considered to have a complex-like structure. Since acrylic acid metal salts are water-soluble in the monomer stage, by impregnating them in a dissolved state in water, they are easily impregnated into the wood cell walls. After impregnation, three-dimensional crosslinking (curing) is achieved by homopolymerization or copolymerization via the vinyl groups in the metal salts.
Then, it forms a water-insoluble hardened resin that stabilizes the dimensions of the wood.

Note that instead of the acrylic acid metal salts, or
A metal methacrylate salt may be used together with the metal salt of acrylate. Methacrylic acid metal salts are
The hydrogen atom on the α carbon atom of the acrylic acid metal salt is substituted with a methyl group.

The polyalkylene glycols used in this invention are not particularly limited, but include, for example, polyalkylene glycol methacrylates such as polyethylene glycol monomethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol monomethacrylate, and polypropylene glycol dimethacrylate; Examples include polyalkylene glycol acrylates such as acrylate, polyethylene glycol diacrylate, polypropylene glycol monoacrylate, and polypropylene glycol diacrylate. These may be used alone or in combination. These polyalkylene glycols are linear polymeric compounds with a degree of polymerization of about 3 to 10 and are water-soluble, so by impregnating them in a dissolved state in water, they can easily penetrate into the wood cell walls. be done. After impregnation, the material is three-dimensionally crosslinked (cured) by copolymerizing with other impregnating components to form a water-insoluble cured resin, thereby stabilizing the dimensions of the interior of the wood.

Acrylic acid metal salts and/or methacrylic acid metal salts, and polyalkylene glycols (hereinafter referred to as "impregnation components") are dissolved in water (hereinafter referred to as "impregnation treatment liquid") as raw materials. The method for impregnating wood with the resin is not particularly limited, and examples thereof include a reduced pressure impregnation method, a pressure impregnation method, a normal pressure dipping method, and a coating method. Before impregnating with the impregnating treatment liquid, it is recommended that the roughening material wood be subjected to a water saturation treatment. This is because the impregnating components contained in the impregnating solution are quickly impregnated (diffused) into the wood using the water in the wood as a medium, so the impregnation time can be shortened. The method of water saturation treatment is not particularly limited, but may be carried out by underwater storage, steaming, reduced pressure impregnation, pressurized impregnation, or the like. Note that when impregnating with the impregnating treatment liquid under reduced pressure, it is not necessarily necessary to perform this water saturation treatment.

In addition, in order to improve processing efficiency, impregnation treatment with impregnating components is usually carried out by including all the necessary impregnation components in one impregnation treatment solution and impregnating the wood with the same impregnation treatment solution. However, the present invention is not limited thereto, and for example, the impregnation treatment liquid may be separately impregnated with a plurality of types of impregnation treatment liquids containing each impregnation component separately. That is, the timing of impregnation with each impregnating component is not limited at all as long as it is before the formation of an insoluble cured resin.

The impregnation ratio of the impregnating components to be impregnated into the raw wood is not particularly limited, but for example, the (total) impregnated amount M of acrylic acid metal salts and/or methacrylic acid metal salts is A, and the impregnated weight of polyalkylene glycols is B. In this case, it is preferable that the weight ratio of A/B is about 0.9 to 9.

The concentration of the impregnating solution is not particularly limited, but for example, when all the impregnating components are impregnated with one impregnating solution, the total concentration of the impregnating components is preferably about 10 to 50% by weight.

The method for producing and fixing an insoluble cured resin in raw material wood that has been impregnated as described above is not particularly limited, but the raw material wood may be impregnated with a radical polymerization initiator in advance and then heated. It is preferable to do so. This allows the insoluble cured resin to be generated within the wood with a high reaction rate and efficiency.

The heating temperature is not particularly limited, but is 50 to 10
The temperature is preferably about 0°C.

The method of impregnating the raw material wood with the radical polymerization initiator is not particularly limited, but for example, a method of adding the radical polymerization initiator to the impregnation treatment liquid and impregnating the raw material wood together with the impregnation treatment liquid, or, Separately from the impregnating treatment liquid, examples include a method of impregnating the raw material wood with an aqueous solution containing only a radical polymerization initiator. That is, the timing of impregnation with the radical polymerization initiator is not limited at all as long as it is before the insoluble cured resin is produced.

The radical polymerization initiator is not particularly limited, and examples thereof include peroxides such as hydrogen peroxide, potassium persulfate, and ammonium persulfate. these are,
They can be used alone or in combination. It can also be used as a redox initiator in combination with a reducing agent.

After the insoluble cured resin is produced in the wood in this manner, the surface of the wood is washed with water, if necessary, and dried to obtain the desired modified wood.

[For production]

If the impregnating component that stabilizes the dimensions of the wood is dissolved in water and impregnated into the ring material wood, and then the impregnating component is reacted, the aqueous solution has good penetration into the wood.
After the impregnating component is impregnated into the wood structure, it changes into a water-insoluble cured resin, resulting in dimensional stabilization even to the inside of the wood. Since the impregnating component reacts at a high reaction rate, there is less unreacted drug remaining. Since the cured product of the impregnating component has a small degree of curing shrinkage, it does not destroy the wood structure. As mentioned above, the impregnating component is efficiently impregnated into the inside of the wood, so the amount of impregnation required for dimensional stabilization is small.Furthermore, after impregnation, it becomes insoluble in water and is fixed inside the wood, so that it does not spread to the wood surface. Since there is no risk of seepage, the wood texture of the wood surface is maintained.

〔Example〕

Hereinafter, specific examples of the present invention will be described in detail together with comparative examples, but the present invention is not limited to the following examples.

Example 1 - Water: aluminum acrylate (aluminum acrylate): polyethylene glycol monomethacrylate) =
To an aqueous solution prepared by blending each component at a ratio of 6+1:1 (weight ratio), 0.5% by weight of potassium persulfate based on the aluminum acrylate contained in the aqueous solution was added and mixed. This aqueous solution is 50 (T direction) x 50 (R direction)
Vacuum pressure (50
m]Hg) After impregnation, it was impregnated for one day by the normal pressure immersion method.

Thereafter, the veneer was heated and dried at 60°C for 24 hours to obtain modified wood.

Example 2 Water diacrylate (zinc acrylate): polyethylene glycol monomethacrylate - 6: to 1 (
, weight ratio) to an aqueous solution prepared by blending each component in a ratio of 0 to zinc diacrylate contained in the aqueous solution.
．． 5% by weight of potassium persulfate was added and mixed. This aqueous solution was impregnated into a Noagatis veneer with dimensions of 50 (T direction) x 50 (R direction) x 4 m (L direction) under reduced pressure (5 ON Hg), and then impregnated for one day by a normal pressure immersion method.

Thereafter, the veneer was heated and dried at 100° C. for 24 hours to obtain modified wood.

Example 3 Water: Magnesium diacrylate (magnesium acrylate): Polyethylene glycol dimethacrylate-6
To a resin aqueous solution prepared by blending each component in a ratio of :I:1 (weight ratio), potassium persulfate was added in an amount of 0.5% by weight based on the magnesium diacrylate contained in the aqueous solution and mixed. This aqueous solution was impregnated under reduced pressure (50 m Hg) into an agathis veneer with dimensions of 50 (T direction) x 50 (R direction) x 4 m 1 m (L direction), and then soaked for one day by a normal pressure immersion method.

After that, the veneer was heated and dried at 100°C for 24 hours,
Obtained modified wood.

Example 4 Water: Magnesium diacrylate: Polypropylene glycol monoacrylate - An aqueous solution prepared by blending each component in a ratio of 10:1:3 (weight ratio) was added to an aqueous solution with a ratio of 0.0% to the magnesium diacrylate contained in the aqueous solution. 5% by weight of potassium persulfate was added and mixed. This aqueous solution, 5
0 (T direction) x50 (R direction) x4fl (L direction)
An agathis veneer of dimensions was impregnated with Ig) under reduced pressure (50 mm), and then impregnated for one day by a normal pressure immersion method.

Thereafter, the veneer was heated and dried at 100° C. for 24 hours to obtain modified wood.

Example 5 - Water: Aluminum acrylate: Polypropylene glycol monomethacrylate - Into an aqueous solution prepared by blending each component in a ratio of 10:3:1 (weight ratio), 0.5% of the aluminum acrylate contained in the aqueous solution was added. weight%
of potassium persulfate was added and mixed. This aqueous solution was
An agathis veneer with dimensions of (T direction) x 50 (R direction) x 4 m (L direction) was impregnated under reduced pressure (5 (lnHg)) and then impregnated for one day by a pressure dipping method.

Thereafter, the veneer was heated and dried at 100° C. for 24 hours to obtain modified wood.

Comparative Example Water: Polyethylene glycol monomethacrylate (PE
C; MA) = 3: ], P contained in the resin aqueous solution prepared by blending each component in the ratio of (weight ratio)
1% by weight of potassium persulfate was added to the EGMA and mixed. This aqueous solution was applied to an agathis veneer with dimensions of 50 (T direction) x 50 (R direction) x 4tm (L direction) under reduced pressure (
After impregnation (50 nHg), it was impregnated for one day by the normal pressure immersion method.

Thereafter, the veneer was heated and dried at 60°C for 24 hours to obtain modified wood.

The impregnation rate, bulking, and anti-swelling (shrinkage) rate were determined for the modified wood obtained in Examples 1 to 5 and Comparative Example.

The impregnation rate is the weight increase (%) of treated wood relative to untreated wood.

Bulking is expressed by the following formula (1).

[In formula (1), Dl represents the dry dimension of untreated wood, and D
2 represents the saturated size of untreated wood and D8 represents the dry size of treated wood. ] The anti-swelling (shrinkage) rate (ASE) is expressed by the following formula (n).

(In formula (II), Sl represents the swelling (shrinkage) rate of untreated wood, and S2 represents the swelling (shrinkage) rate of treated wood.) The above results are shown in Table 1.

Table 1 The active ingredients produced inside the modified wood are insoluble in water, so there is no risk of them seeping out onto the surface of the wood due to water or moisture, so the modified wood also has water resistance and moisture resistance. have

Also, depending on the type of active ingredient produced in the modified wood, the amount of wood! It is also possible to improve flammability, wear resistance, surface hardness, etc.

As shown in Table 1, the modified wood obtained in Examples 1 to 5 does not differ much in impregnation rate and bulking compared to the modified wood obtained in Comparative Examples, but the dimensional stability It can be seen that the performance is excellent (ASE is high).

〔Effect of the invention〕

According to the method for producing modified wood according to the present invention, the interior of the wood is dimensionally stabilized, there is little residual odor from unreacted chemicals, the wood structure is not destroyed, it has excellent antiseptic and insect repellent properties, and it has a wood texture on the surface. Modified wood with no loss of properties can be efficiently obtained.

Agent Patent Attorney Takehiko Matsumoto Procedural Amendment (Volunteer 1. Case Indication aMFL2-197362 No. 3,?!Relationship with the person making the correction case Patent Applicant Address 1048 Kadoma, Kadoma City, Osaka Prefecture Name ( 583) Matsushita Electric Works Co., Ltd. 4, Agent 5゜ Name (7346) No number of terms increased due to patent attorney amendment Takehiko Matsumoto - 5' Suji! = ν: 6,?! Positive subject specification 7, 7! iCorrect Content■ In lines 7 to 10 of page 3 of the specification, the statement ``(a) Unreacted acetic acid that cannot be obtained by the method ■ above'' has been replaced with ``(a)
In the method ① above, the by-product is acetic acid.''

(2) In lines 2 and 3 of page 4 of the specification, the phrase ``if the reacted resin cures, its curing shrinkage'' is corrected to read ``curing shrinkage of the reacted resin itself.''

■ On page 4, lines 7-8 of the specification, it says, "This invention achieves dimensional stability even inside the wood, and there is little residual odor from unreacted chemicals.""Not a lot," he corrected.

■ Lines 8 to 9 of page 6 of the specification and page 6 from the bottom of page 7
In two places in lines 5 to 5, the phrase ``forming a cured resin to stabilize the dimensions of the inside of the wood'' should be corrected to ``forming a cured resin to stabilize the dimensions of the wood.''

■ On page 11, lines 8 to 10 of the specification, the statement ``As a result, the size of the inside of the wood...residual odor of unreacted chemicals is reduced'' is replaced by ``As a result, the wood becomes highly dimensionally stable. The ingredients change into the resin with a high reaction rate and low odor, so the odor of the modified wood is reduced.''

■ In lines 5 to 3 from the bottom of page 17 of the specification, the phrase "modification according to this invention... has little residual odor and destroys wood structure" is replaced with "modification according to the method of producing modified wood according to this invention". "It is highly dimensionally stable, has little odor, and destroys wood structure."

Claims (1)

[Scope of Claims] 1. After impregnating raw wood with at least one of metal acrylates and metal methacrylates and at least one of polyalkylene glycols dissolved in water, A method for producing modified wood that produces and fixes an insoluble cured resin within the structure of the wood. 2 The polyalkylene glycols are polyalkylene glycol acrylates and/or polyalkylene glycol methacrylates, and when an insoluble cured resin is generated and fixed in the raw material wood structure, a radical polymerization initiator is also added to the raw material wood in advance. 2. The method for producing modified wood according to claim 1, wherein the resin is generated and fixed by impregnating the wood and heating the wood.