JPH08267411A - Antibacterial wood architectural material - Google Patents

Abstract

PURPOSE: To provide an antibacterial wood architectural material with excellent tick proliferation inhibitive effects. CONSTITUTION: This antibacterial wood architectural material consists of a veneer of precious wood with a coated surface, adhered to a wood base through an adhesive. The coat contains hinoki thiol, and the adhesive contains a microcapsule which envelops an essential oil impregnated with a resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial wood building material capable of exerting a forest bathing effect and having excellent repellent effect against living pests and suppression of proliferation, and particularly, to a house dust mite, a dwarf spider mite, etc. that inhabits human living environment. The present invention relates to an antibacterial wooden building material having excellent anti-mite properties against mites.

[0002]

2. Description of the Related Art Conventionally, with regard to antibacterial wood building materials, a multi-layer emulsion treatment of various essential oil components (Patent No. 18236)
No. 30, etc.), and a method of adding and using the same to an adhesive for decorative veneer (Japanese Patent Laid-Open No. 3-61001, etc.), and a method of further adding an essential oil component to a coating material (special Kaihei 2-26809, etc.) has been proposed.

By utilizing these techniques, the essential oil component is diffused from the surface of the wooden building material for a long period of time, and the indoor space is filled with the essential oil component to bring about a forest bathing effect in the room and at the same time harmful mites in the real life. -It has become possible to give wood building materials the effect of suppressing or repelling the breeding of harmful insects such as cockroaches and mosquitoes, and mold.

However, it is necessary to evaporate a large amount of the essential oil component in order to enhance its efficacy such as antibacterial action, but on the other hand, it is necessary to suppress the evaporative amount in order to enhance the sustained release property and maintain the effect for a long period of time. Since it is necessary to have a contradictory function that there is, its effect and sustainability are
I was still not satisfied. When a high boiling point substance that is difficult to evaporate is used as an essential oil component to be added to the adhesive in consideration of sustainability, it is meaningless because the amount of evaporation from the surface of the wooden building material decreases and the effect itself decreases.

Therefore, it is effective to microencapsulate a highly volatile essential oil component and add it to the adhesive in order to maintain a relatively high effect for a long period of time. However,
As the highly volatile essential oil component used in this case, a small amount that is sufficiently effective against living organisms is not known. Therefore, when a large amount of highly volatile essential oil component is added to the adhesive in order to improve the efficacy against living organisms, there is a drawback that the adhesive performance is deteriorated.

[0006]

Accordingly, the present inventors diligently studied a more excellent essential oil-containing wood flooring material, and when the essential oil and hinokitiol were used in combination, the mite growth inhibitory performance was particularly expected. With the above improvements,
They have found that their performance also lasts for a long period of time and have reached the present invention. Therefore, it is an object of the present invention to provide an antibacterial wood building material which is particularly excellent in mites growth inhibitory performance.

[0007]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
A wood building material formed by sticking a name wood veneer with a surface coated on a wood base material via an adhesive, and containing hinokitiol in the coating, and in the adhesive, This has been achieved by an antibacterial wood building material containing microcapsules containing essential oil impregnated in a resin as a core substance.

Generally, an essential oil is composed of 100 or more kinds of components, but since it is necessary to fill the indoor space with the essential oil component in order to impart a forest bathing effect, in the present invention, a large amount of a component having a relatively high transpiration property is used. It is preferable to add the essential oil contained in the adhesive to the adhesive. In addition, in order to evaporate the essential oil component for a long period of time, it is necessary to microencapsulate the essential oil, but with normal microcapsules, it is destroyed when the veneer is thermocompression-bonded onto the wood base material. In the present invention, the essential oil is not simply encapsulated in the microcapsules, but the resin is impregnated with the essential oil to form the core substance.

The resin as the core substance may be any resin that absorbs essential oil and swells, but in particular, a resin obtained by polymerizing or copolymerizing at least one of acrylic acid, methyl methacrylic acid, and vinyl acetate monomer. preferable. The polymer used as the wall material of the microcapsule can be appropriately selected from known polymers capable of emulsion polymerization. Such a microcapsule is described in JP-A-3-61001. The essential oil used in the present invention is particularly preferably an essential oil collected from cypress and cedar.

On the other hand, Taiwan cypress, hiba or red
"Hinokitiol (β-tsuyaprisin)" contained in the seeder has extremely high bactericidal activity and repellent effect against harmful insects, but is compatible with a substance used for emulsification, and in addition to being difficult to microencapsulate, Since it has a high boiling point, it is hardly expected to evaporate from the surface of the wooden building material even if it is added to the adhesive.

Therefore, in the present invention, hinokitiol is added to the coated portion of the surface layer of the wooden building material.
Hinokitiol is an antibacterial substance specifically contained in cypress family tree species, and its antibacterial properties and the like are known to have many properties as outlined below (Mitsukatsu Yata, Aromatopia No. 9 (1994)). As the cypress family tree species, Asunaro asunaro, other cypress asunaro, Kurobe genus Neko, sugi, incense cedar genus incense cedar, squirrel Ibuki, Heinez,
There are Hinoki cypress, Hinoki cypress, Benihi, Konotega wrinkle, etc.

The antibacterial activity of hinokitiol is remarkable, and the bactericidal action of hinokitiol diluted to 4,000 to 5,000 times against Mycobacterium tuberculosis and 1 against typhoid fever.
Even if it is diluted 10,000 times, it has a bactericidal action. Furthermore, against Bacillus subtilis, Salmonella typhi, Paratyphi, Shigella, Cholera, Diphtheria, Proteus, Pneumococcus, Streptococcus pneumoniae, Streptococcus pneumoniae, etc., antibacterial properties are about 2,000 to 10,000 times diluted. Is recognized.

It also has antibacterial properties against fungi, and it is effective against Aspergillus, Fusarium, Penicillium, etc.
It is known to show a growth inhibitory action at several tens of ppm, and in addition to these bacteria and fungi, it has antibacterial activity against spirochetes, plant pathogens, and the like. Furthermore, even with respect to mesicillin-resistant Staphylococcus aureus (MRSA), its growth can be completely inhibited at about 100 μg / ml (Toshihiro Okabe et al., Proceedings of the Japan Wood Research Society, 44,
494 (1989)).

The name wood veneer used in the present invention has a thickness of 0.2.
It means a so-called thin decorative veneer having a thickness of 5 to 0.33 mm, and can be appropriately selected and used from known decorative veneers. Examples of the wood base material to which the name wood veneer is attached include plywood, particle board, hard board, MDF and the like. The adhesive for sticking the name wood veneer to the wood base material can be appropriately selected from known adhesives, and in the present invention, it is appropriate in the range that the adhesive strength can be sufficiently maintained in this adhesive. The amount of essential oil encapsulated in microcapsules is added and used. The amount of the adhesive used is such that the adhesive force is sufficient and the amount of essential oil is 10 to 40 g / m ² .

On the other hand, the amount of hinokitiol or the like added to the coating material applied to the surface of the veneer is 0.05 to 0.50 g / m ²
It is preferred that 0.05 g / m antimicrobial effect is ² or less is insufficient, when it comes to 0.50 g / m ² or more,
The coating film is likely to crack. In addition, the addition of hinokitiol to the paint is dissolved in the paint solvent such as toluene,
Alternatively, it may be dispersed.

[0016]

EFFECTS OF THE INVENTION The wood-based building material of the present invention uses both essential oils and hinokitiol in combination, so not only is it excellent in antibacterial properties,
It is possible to exert a growth inhibitory effect on mites more than can be predicted from the individual effects of essential oil and hinokitiol.

[0017]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto.
In addition, "%" represents "wt%" unless otherwise specified.

Example 1. In a rubber latex adhesive (“SB-1125” manufactured by Mitsui Toatsu Co., Ltd.), 2 essential oil components were added.
25% by weight of microcapsules (made in-house) containing 5%
It was blended so that The obtained adhesive was applied to a 12 mm-thick plywood plate at 150 g / m ^2, and then a 0.3 mm-thick wet veneer was attached by thermocompression bonding at 105 ° C. and 6 kg / cm ² for 50 seconds.

Next, hinokitiol: thinner (an IST roll diluent manufactured by Natco Paint Co., Ltd.) was added at 1: 100.
Then, the two were mixed so as to obtain a UV-curable coating material (IST # 230 manufactured by NATCO PAINT CO., LTD.): The hinokitiol-containing thinner was mixed at 100: 10 to prepare a coating material. The obtained coating material was applied to the surface of the veneer so that the coating amount was 85 g / m ^{2, and then} the coating material was cured using an ultraviolet curing device to produce an antibacterial wood building material. Also, a comparative wood building material (for blank) was prepared in exactly the same manner except that essential oil and hinokitiol were not used.

With respect to the obtained wooden building material, a mite proliferation inhibitory performance test was carried out as follows, immediately after preparation and after being left for 2 years in an indoor environment of 25 ° C. and a humidity of 63%.
Each wooden building material cut into 4 cm x 4 cm has a diameter of 9 c
Place in a sterile petri dish with the coated surface facing up,
A medium (powdered feed:
Rat feed + dry yeast) About 0.5g 3cm ×
Spread to 3 cm. There were 100 mites in the medium.

The inside of this petri dish was conditioned to about 86% with a saturated potassium chloride solution, stored at a temperature of 25 to 30 ° C., and after 3 weeks, the number of living mites in the medium was counted under a stereoscopic microscope. Then, as a result of obtaining the growth inhibition rate shown in the following formula,
The mite growth inhibitory performance of the wood-based building material of the present invention was 59.0% immediately after the building material was manufactured, and 56.2% even after two years, which was extremely good. Growth inhibition rate (%) = (1-T / C) x 100 T is the number of living mites in building materials containing essential oils and components C is the number of living mites in targeted blank building materials

Example 2. The essential oil component in the adhesive is 0, 5.
0, 10.0, 40.0, 80.0 g / m ² divided into 5 steps, and the hinokitiol in the paint at each step was 0.0, 0.01, 0.05, 0.1
Thirty types of antibacterial wood building materials were produced in the same manner as in Example 1 except that the conditions were 0, 0.50 and 1.00 g / m ² . The results obtained by measuring the growth inhibitory rate against mites in exactly the same manner as in Example 1 are as shown in Table 1.

[0023]

[Table 1] The values in parentheses in the table represent the sum of the effects of hinokitiol alone and the effects of essential oil alone.

From Table 1, it can be seen that the mite growth inhibitory performance is 12% or more at the essential oil amount of 5 g / m ² or more, and the effect is recognized, and the effect increases as the added amount of the essential oil increases, Is further increased by the addition of hinokitiol to the paint, and is 40% or more at 0.05 g / m ² or more, and the efficacy when using essential oil and hinokitiol in combination is only when using the essential oil and when only hinokitiol is used. It proved to be larger than the sum when used.

[0025] For example, essential oils when not using the 80.0 g / m ² hinokitiol using, and the mite growth inhibition rate in the case where only hinokitiol without the essential oil was used 1.00 g / m ² simply respectively in addition even, the essential oil and hinokitiol, falls short of mite growth inhibition rate when used in combination respectively 80.0 g / m ² and 1.00 g / m ² simultaneously. This demonstrates that the combined use of essential oil and hinokitiol produced a synergistic effect.

Example 3. The essential oil component in the adhesive is 0, 5.
The antibacterial wood was made in the same manner as in Example 2 except that hinokitiol was not added to the paint on the surface and the paint was divided into five stages so as to obtain 0, 10.0, 40.0 and 80.0 g / m ^2. Building materials were produced. The effect of adding essential oil on the adhesive strength
A Type 2 immersion peeling test according to the Japanese Agricultural Standards for special plywood was performed, and the pass rate (%) was evaluated. The results are shown in Table 2.

[0027]

[Table 2] ─────────────────── Amount of essential oil added Type 2 Dipping and passing rate (g / m ² ) (%) ───────── ─────────── 0.0 100 5.0 5.0 100 10.0 10.0 40.0 98 80.0 87 ──────────────────── The results in Table 2 show that the upper limit of the essential oil added to the adhesive is about 40.
It is shown that it is preferable to set g / m ² (about 27% of the adhesive).

On the other hand, the content of hinokitiol in the paint is 0.0, 0.01, 0.05, 0.10, 0.50,
Divide into 1.00 g / m ² and add the hinokitiol addition to the adhesive without adding essential oil to the adhesive.
Evaluation was made based on the adhesion pass rate and the number of cracks in the coating film.
The results are as shown in Table 3. The adhesion pass rate is the general test method for paints (JIS K5400-1990).
Was performed according to the cross-cut tape method, and the percentage was defined as the number of squares that did not come off. The number of cracks in the coating film was determined by repeating the cold heat cycle B test of the Japanese agricultural standard for special plywood, and then counting the number of cracks in the coating film having a length of 3 mm or more.

[0029]

[Table 3] ──────────────────────── Hinokitiol Adhesiveness Number of cracks Addition amount (g / m ² ) Pass rate (%) (book) ─ ─────────────────────── 0.00 0.00 100 20 0.01 0.01 100 18 0.05 0.05 100 24 0.10 100 20 20 0.50 95 30 30 1. 00 77 69 ──────────────────────── The results of Table 3 show that the upper limit of the amount of hinokitiol added during coating is about 0.5 g / m 2. ² (1% of paint) is shown to be preferable.

Claims (2)

[Claims] 1. A wood building material comprising a wood veneer whose surface is coated on a wood base material with an adhesive,
While containing hinokitiol in the coating,
An antibacterial wood building material, characterized in that the adhesive contains microcapsules in which an essential oil impregnated with a resin is included as a core substance. 2. The amount of essential oil contained in the adhesive is 10 to 40 g / m ² per surface area of building material, and the amount of hinokitiol contained in the surface coating is 0.0 per surface area of building material.
The antibacterial wood building material according to claim 1, which has an amount of 5 to 0.50 g / m ² .