JP3202907B2 - Wood preservation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for preserving and treating wood, and more particularly to a method for chemically processing and preserving wood products, preventing fungi and / or termites, and wood products obtained thereby.

[0002]

2. Description of the Related Art For the purpose of imparting preservation, fungicide and / or termite resistance to wood, various chemicals have been used by impregnating the wood. However, many of the conventional chemicals are toxic, and health problems for workers and product users have been pointed out, and improvements in chemical treatment and disposal are required. In particular, toxicity is a problem, water-soluble fixing type preservatives,
Termites. These are preservatives and termites that use low-cost water as a solvent for the treatment agent and remain fixed in the wood, such as chromium copper arsenic preservative (CCA) and fluorochrome arsenic preservative (FCAP). is there. These arsenic and chromium compounds have been banned worldwide because of their extremely high toxicity. Many antifungal agents are also highly toxic, like preservatives. Chlorophenols have long been used because of their high fungicidal properties and persistence. However, since carcinogenic dioxin is contained as an impurity, use is being banned. In addition, many of the fungicides are water-insoluble and have a disadvantage that they lack practical convenience.

On the other hand, as a method for imparting dimensional stability to wood, there is a method in which hydroxyl groups in wood are chemically modified to suppress the absorption of moisture. Such methods include oligoesterification, etherification, acetylation, formalization, and maleic-glycerin treatment. Japanese Patent Application Laid-Open No. 64-8001 discloses that wood is impregnated or coated with a polyvalent carboxylic acid and a polyhydric alcohol and heated to react with wood constituents (cellulose, hemicellulose, lignin) by a reaction mainly involving a dehydration bond. A method for forming a three-dimensional network structure and imparting dimensional stability and decay resistance of wood is disclosed. This method has the advantage that the toxicity of the chemical used for the treatment is low, and high dimensional stability and decay resistance can be ensured at low cost. Also, JP-A-7-32313
Discloses that fungicidal properties can be imparted by a similar chemical treatment. However, the antiseptic and fungicidal properties obtained by such chemical processing mainly for the purpose of dimensional stability are sufficient compared with antiseptics such as TBZ [2- (4-thiazolyl-benzimidazole)]. Rather, depending on the conditions of use, higher antiseptic, antifungal and / or termite resistance is required. In such a case, it was necessary to separately impregnate with an antiseptic, antifungal and / or termitic agent by coating or the like.

[0004]

As described above, by subjecting wood to chemical processing, it is possible to impart dimensional stability and to improve antiseptic, antifungal and / or termite resistance. However, in order to impart high antiseptic, antifungal and / or anti-termite properties, it was necessary to separately perform antiseptic, anti-fungal and / or anti-termite treatment. In addition, ordinary antiseptic, antifungal and termite treatments have the drawback that they only impregnate and apply chemicals, do not chemically bond to wood substrates, and leaching out when contacted with solvents such as water. . Also, if the drug used is toxic, leaching will inevitably affect the health of the user. In addition, the effect is gradually lost due to leaching,
It is difficult to maintain long-term performance. Accordingly, an object of the present invention is to improve these drawbacks, secure effects such as dimensional stability by chemical processing, and at the same time, impart high antiseptic, antifungal, and / or termite resistance, and at the same time, have high safety. Another object of the present invention is to provide a method for preserving and processing wood, which has a long-lasting effect, and to provide a wood product having excellent dimensional stability, antiseptic properties, antifungal properties and / or termite resistance.

[0005]

According to the present invention, in order to achieve the above object, in a chemical processing of wood including a heat treatment in a treatment step, a treatment liquid is a polyvalent carboxylic acid or a polycarboxylic acid.
Is a mixture of its derivatives and polyhydric alcohols or
And a betaine-type structure as a chemical having a reactivity to a wood substrate and / or a reactive group of the processing liquid and exhibiting antiseptic, antifungal and / or termite-proofing properties.
Storage processing method of the wood which comprises treating by adding amphoteric surfactant having the Ru is provided. By treating wood in such a way, in addition to the performance such as dimensional stability originally obtained by chemical processing, high preservation,
A wood product having fungicidal and / or termite-proof properties and maintaining these effects for a long period of time is provided.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The method for preserving wood according to the present invention comprises:
The chemical processing solution has a betaine-type structure as an antiseptic, fungicide and / or termite-proofing agent (hereinafter referred to as a drug) having reactivity to reactive groups of the wood substrate and / or the processing solution.
By adding a zwitterionic surfactant , high antiseptic, antifungal and / or termite resistance is imparted to wood. That is, a solid exhibiting antiseptic, antifungal, and / or termitic properties
A zwitterionic surfactant having an in-type structure reacts with and binds to a reactive group (hydroxyl group) of a wood substrate, or reacts with a reactive group of a wood substrate to form a reactive group ( (Hydroxyl group, carboxyl group, etc.), or by reacting with and reacting with both reactive groups, leaching from wood is suppressed to a low level, and long-lasting antiseptic, antifungal and / or Termite resistance is imparted,
Of course, effects such as dimensional stability by the chemical processing can also be obtained.

[0007] As is clear from the above description, the above-mentioned chemicals are compounds having reactivity to the reactive groups of the wood substrate and / or the treating solution to be used, and exhibiting preservative, fungicide and / or termite resistance. All are available, but these
Above all, a zwitterionic surfactant with a betaine structure is necessary.
Used as an ingredient . As the chemical processing solution, conventionally known various processing solutions such as maleic acid-glycerin treatment, oligoesterification treatment, etherification treatment, acetylation treatment, and formalization treatment can be used. But especially as a chemical processing solution,
Using a treatment liquid containing a mixture or condensate of a polyhydric carboxylic acid or a derivative thereof and a polyhydric alcohol, and impregnating or applying these, and then adding the chemical to the treatment liquid in the chemical processing of wood to be heat-treated. As a result, it is possible to impart excellent preservability, fungicide and / or termite resistance to the wood at the same time as dimensional stability, and it is excellent in handling and processing properties, and has high safety and high safety for workers and product users. A wood product with little effect on the health of the plant is obtained.

As the chemical processing used in the present invention, for example, a maleic acid-glycerin treatment will be described. The maleic acid-glycerin treatment is a method in which a mixture of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol or a solution of these condensates is treated with impregnation or coating on wood, and heated to form a carboxylic acid group of the polyvalent carboxylic acid. An ester bond is formed between the hydroxyl group of the polyhydric alcohol and the hydroxyl group of the wood cellulose to form a resin in the wood and impart dimensional stability.

The polyvalent carboxylic acids used in such chemical processing include dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, adipic acid and phthalic acid, anhydrides thereof and Derivatives, trivalent carboxylic acids such as trimellitic acid, anhydrides and derivatives thereof, tetravalent carboxylic acids such as pyromellitic acid, anhydrides and derivatives thereof, and the like. The polyhydric alcohol used in the present invention includes ethylene glycol, diethylene glycol, dihydric alcohols such as propylene glycol, trihydric alcohols such as glycerin, various saccharides, sugar alcohols and the like, and further polyols such as polyvinyl alcohol and the like. Can be used. Best results are obtained, especially when using maleic acid and glycerin.

After mixing the polyhydric carboxylic acid and the polyhydric alcohol, an appropriate solvent is added to prepare a treatment liquid. After the treatment liquid is impregnated into the wood, the wood is dried and heated in a heating furnace to a predetermined temperature. The treatment temperature is set to a temperature equal to or higher than the temperature at which esterification proceeds during heating and equal to or lower than the temperature at which wood is thermally decomposed. Actually, the temperature is desirably from 120 ° C to 180 ° C. It is desirable that the rate of weight increase of the wood by the treatment is set to 5% or more and 35% or less.

[0011] The preservative, fungicide and / or termite-resistant agent having reactivity with the reactive group of the wood substrate and / or the treatment liquid means a chemical having a reactivity with a carboxyl group or a hydroxyl group, Carboxylic acid, hydroxyl group, thiocarboxylic acid,
It refers to a drug that has a reactive group such as thiol, sulfonic acid, amine, isocyanate, or epoxy, and does not lose its effect even after the reaction. Specifically carboxymethyl betaine, imidazolium Riniu Yibin tie down and the like.

Also, quaternary ammonium compounds are mentioned as agents having low toxicity and excellent antiseptic, antifungal and termite resistance properties. The quaternary ammonium compound is used as a surfactant, and functions as a cationic surfactant since a tetravalent nitrogen atom has a positive charge. This N ⁺
Inhibits the cell surface function of wood and exhibits antiseptic, antifungal and ant-control effects. Examples of the cationic surfactant include an aliphatic quaternary ammonium salt, an aromatic quaternary ammonium salt, and a heterocyclic quaternary ammonium salt represented by the following chemical formulas (A) to (C). In particular, the aromatic quaternary ammonium salt represented by the chemical formula (B) exhibits excellent antiseptic, antifungal and termite resistance.

Embedded image In the chemical formulas (A) to (C), R ₁ is an alkyl group having 10 to 18 carbon atoms, R ₂ is an alkyl group having 1 to 18 carbon atoms, R ₃ is an alkyl group having 8 to 24 carbon atoms, ₄ represents an alkyl group of 8-18 carbon atoms, X ₁ ^- is Cl ^-, Br ^- or I
^-, X ₂ ^- is Cl ^- or Br ^- represent.

The amphoteric surfactant contained as an essential component in the present invention includes carboxybetaine, imidazolinium betaine having the structure represented by the following chemical formulas (D) and (E), and And quaternary ammonium compounds such as derivatives of

Embedded image In the chemical formulas (D) and (E), R ₄ is an alkyl group having 8 to 18 carbon atoms, n is an integer of 1 or 2, R ₅
Represents an alkyl group having 12 to 18 carbon atoms. The above drug shows an effect at an addition concentration of 0.2% or more, and shows a practically sufficient effect at an addition concentration of 1% or more. The upper limit of the amount of drug added is not particularly limited, but is preferably 7% or less in view of cost.

When a maleic anhydride-glycerin solution is used as the chemical processing solution, the cationic surfactants represented by chemical formulas (A) to (C) combine with the maleic acid anion (carboxylate ion) to form an emulsion. To form In such a case, a transparent solution can be obtained by adding a water-soluble organic solvent such as alcohol. When a heating step is included as a chemical processing step, the alcohol is volatilized by heating, the above-mentioned cationic surfactant adheres to the cell wall surface of wood as an emulsion, and further, a resin film formed by a reaction between maleic acid and glycerin. It is taken in.

By the way, an aqueous solution of benzalkonium chloride reacts with an acid to form an emulsion and is not suitable for permeation into a thin tube such as a wood conduit. Therefore, it is necessary to add an organic solvent. On the other hand, the zwitterionic surfactants represented by the chemical formulas (D) and (E) dissolve in an acidic aqueous solution and can coexist with maleic acid or the like. These have a carboxylic acid group and react similarly to the carboxylic acid group of maleic acid,
It is taken into the resin. In addition, since it is taken in by a chemical bond, it does not leach out, and the effect is maintained for a long time. These agents are also effective when used in addition to the maleic acid-glycerin treatment and added to treatment solutions such as oligoesterification treatment, etherification treatment, acetylation treatment and formalization treatment.

To treat these chemicals into wood, a solution prepared by mixing the chemical processing solution with the chemical at a predetermined ratio is impregnated into the wood by coating or the like, and is reacted inside the wood by drying and heating. It should be done. When an aqueous solution is used, it is necessary to raise the temperature according to a drying schedule in order to prevent cracking due to drying. After sufficient drying, the temperature is further raised to carry out a chemical reaction between the chemical processing solution, chemicals, and wood components. The temperature at this time is desirably from 120 ° C. to 180 ° C. If the temperature is lower than 120 ° C., a sufficient reaction does not occur, and the reaction between the chemical processing solution, the chemical, and the wood component does not sufficiently proceed, and leaching is observed, which is not preferable. On the other hand, when the treatment is performed at a temperature higher than 180 ° C., the wood is deteriorated, and problems such as discoloration and reduced strength occur, which is not preferable.

[0017]

EXAMPLES Hereinafter, the effects of the present invention will be specifically described with reference to Test Examples and Examples, but it goes without saying that the present invention is not limited to the following Test Examples and Examples. First, a test example of a sample prepared using a benzalkonium chloride salt (hereinafter referred to as BKC) and an alkyl betaine (Nissan Anone BF, manufactured by NOF Corporation, hereinafter referred to as BF) will be described. The action and fungicidal performance of the product will be described.

Test Example 1 An aqueous solution of maleic anhydride 3 to glycerin 2 having a concentration of 20% was prepared, and BKC and BF were added thereto to 1% and 5%, respectively. 30% for the solution containing BKC
Was added and completely dissolved. Pieces of the chemical processing solution were impregnated into bunches and dried. In addition, as another sample, after drying, a heating reaction was performed at 160 ° C., and then a weathering operation was further performed. JIS for weatherproof operation
The method described in A9201 Wood Preservative Performance Standards and Test Methods was followed. About the obtained sample, Aspergillus niger (Aspergillus niger van Tieghem) and Aureobasidium pullulans Arnaud (Aureobasidiu)
m pullulans Arnaud) was tested for antifungal performance on an agar medium. Table 1 shows the results.

[Table 1]

As shown in Table 1, in the case of drying only, both BKC and BF form halos. This indicates that there is leaching of the drug from the sample, and is a result of the leached drug acting on bacteria on the agar medium. On the other hand, among the samples subjected to the weathering operation after the heating reaction, only the sample to which 5% of BKC was added shows the halo effect. The BKC 1% sample does not show a halo effect as a result of surplus BKC flowing out by the weathering operation. The sample containing 5% BKC contains a sufficient amount of BKC to exhibit the halo effect even after the weathering operation, and can suppress bacteria around the sample. Regarding BF, neither the 1% addition nor the 5% addition sample shows the halo effect after the weathering operation. This is presumably because the carboxyl group of BF reacts with glycerin or cellulose and is fixed inside and does not elute. In addition, the same effect was confirmed for rot fungi. In the case of only drying, BKC,
Both BF and surrounding rot bacteria are suppressed, and the hypha does not cover the sample itself. Except for the BKC 5% sample, the surroundings are not affected after the weathering operation, but there is no weight loss of the sample.

Test Example 2 A mixed solution of maleic anhydride 3 and glycerin 2 was prepared, and a sample containing 5% of BF added thereto was solidified at 160 ° C.
After solidification, it was pulverized and washed repeatedly with distilled water. FIG. 1 shows an IR spectrum of a solidified solution of only a mixed solution of maleic anhydride 3 and glycerin 2. FIG. 2 shows an IR spectrum of the solidified product of the sample to which BF was added before washing, and FIG. 3 shows an IR spectrum of the solidified product after washing and dried. FIG. 2 shows 2927 cm ⁻¹ , 285 not shown in FIG.
6cm ^-1, 891cm ^-1, the peak of 723cm ^-1 is confirmed. In FIG. 3, these peaks are confirmed as in FIG. 2, indicating that BF is bonded to the resin formed by maleic anhydride and glycerin via a chemical bond and is not easily leached. As described above, by adding a preservative having a reactivity to the chemical processing solution, a fungicide, an anti-termitic agent, and performing a heat treatment, it is difficult to leaching,
It is possible to obtain antiseptic, antifungal, and termite-treated wood that has a long-lasting effect.

Example 1 To a 20% aqueous solution of 3 parts of maleic anhydride and 2 parts of glycerin was added 1% of alkyl betaine (Nissan Anone BF, manufactured by NOF Corporation) to prepare a treatment liquid. Next, Kiguchi 5
A wood test piece having a size of 20 mm and a length of 50 mm was impregnated with the treatment liquid, dried, and then subjected to a heating reaction at 160 ° C. In accordance with the Wood Conservation Society Standard No. 2 "Testing method for fungicide efficacy of fungicides for wood", this sample was further subjected to Penicilliu in addition to the above two kinds of bacteria.
m funiculosum Thom), Gliocladium virens Miller and Rhizopus javanicus Takeda
The fungi of the species were tested for fungicidal efficacy. The test results are shown in Table 2 as efficacy values. The sample to which the alkyl betaine was added showed good fungicidal properties.

[Table 2]

Example 2 1% of alkyl betaine (Nissan Anone BF, manufactured by NOF Corporation) was added to a 20% aqueous solution of maleic anhydride 3 and glycerin 2 to prepare a treatment solution. Next, Kiguchi 1
A wood test piece having a size of 0 × 20 mm and a length of 20 mm was impregnated with the treatment liquid, dried, and then subjected to a heating reaction at 160 ° C. The obtained sample was left on the termite's nest for one month, and the state of eating damage was examined. Compared to the untreated sample, the sample treated with the treatment solution containing alkyl betaine was not damaged.

[0023]

As described above, according to the treatment method of the present invention, in addition to the performance such as dimensional stability obtained by the conventional chemical processing, it is excellent in antiseptic, antifungal and / or termite resistance. Chemically processed wood can be obtained. Moreover, the chemical processing solution has a preservative that is reactive with the wood substrate and / or the processing solution.
Betaine type structure as a fungicidal and / or termite-inhibiting agent
Since a zwitterionic surfactant having the formula (1) is added to chemically fix the drug, leaching can be suppressed, and the antiseptic, antifungal and / or anti-termite effects can be maintained for a long period of time. In addition, the chemicals used in the present invention have high safety, especially when maleic acid and glycerin are used as chemical processing solutions, their toxicity is extremely small, and they are chemically fixed in wood to suppress leaching. Therefore, there is an advantage that the health of workers and product users is hardly adversely affected.

[Brief description of the drawings]

FIG. 1 shows an IR spectrum of a solidified product of a mixed solution of maleic anhydride 3 and glycerin 2.

FIG. 2 shows an IR spectrum of a sample obtained by adding 5% of alkylbetaine to a mixture of maleic anhydride 3 and glycerin 2 before washing the solidified product.

FIG. 3: After washing the solidified sample of a sample obtained by adding 5% of alkyl betaine to a mixture of maleic anhydride 3 and glycerin 2,
The IR spectrum of the dried product is shown.

Continuation of front page (56) References JP-A-2-45102 (JP, A) JP-A-59-70503 (JP, A) JP-A-52-110803 (JP, A) JP-A-64-8001 (JP) JP-A-7-32313 (JP, A) JP-A-1-182002 (JP, A) JP-A-51-1603 (JP, A) JP-A-2-104507 (JP, A) 7-117015 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B27K 3/02-3/52

Claims (6)

(57) [Claims] In a chemical processing of wood including a heat treatment in a treatment step, a treatment liquid is a polyvalent carboxylic acid or a polycarboxylic acid thereof.
Derivatives and mixtures of polyhydric alcohols or condensates of these
A solution having a betaine-type structure as a chemical having a reactivity with a wood substrate and / or a reactive group of the processing liquid and exhibiting antiseptic, antifungal and / or anti-termite properties in the processing liquid.
A method for preserving wood, wherein the treatment is carried out by adding a zwitterionic surfactant . 2. The method according to claim 1, wherein the drug is carboxybetaine and / or
The method for preserving wood according to claim 1, wherein the method is imidazolinium betaine. Wherein the treatment liquid, preservation method of the wood according to claim 1 or 2 which is a solution of a mixture or condensate of maleic acid and anhydrous glycerin. 4. The method for preserving wood according to claim 1, wherein the treating solution is a solution of a mixture or a condensate of maleic anhydride and glycerin, and the added agent is alkyl betaine. 5. The temperature of the heat treatment is 120 ° C. or higher and 18.
The method for preserving wood according to any one of claims 1 to 4 , wherein the temperature is 0 ° C or lower. 6. Wood having antiseptic, antifungal and / or ant-proof properties, which has been treated by the method for preserving wood according to any one of claims 1 to 5 .