JP3295112B2 - Water resistant treatment of woody materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for waterproofing a wood material having a wood fiber layer exposed at the tip of the wood, for example, a wood material such as a medium fiber board, a hard board, a particle board and a plywood.

[0002]

2. Description of the Related Art Wood materials such as those described above, for example, urea-type medium fiberboards which are generally used, have insufficient water resistance. This is due to the following reasons. That is, as is well known, the medium fiber board is a water-absorbing wood fiber layer in which the front and back surfaces are hard and the middle portion is soft, so that in a product state, the wood fiber layer is exposed to the side end of the wood fiber. Become. For this reason, moisture is easily absorbed into the fiber layer from the tip of the tip and penetrates into the interior, and the absorbed moisture causes the fiber structure to swell in the thickness direction. Specifically, the medium fiberboard is 7
When subjected to a water resistance test in which immersion in hot water at 0 ° C. for 2 hours and drying at 60 ° C. for 3 hours are sequentially performed, moisture penetrates from the inside of the wood to the inside and the medium fiberboard swells significantly in the thickness direction. And lower strength.

[0003] Such poor water resistance is observed not only in a medium fiberboard, but also in a wood material such as a hard board, in which a wood fiber layer is exposed at a wood opening.

[0004] Therefore, in order to prevent the ingress of moisture from the lip, the lip is filled with a resin to seal the lip.

[0005]

However, since the wood fibers protrude irregularly from the wood surface and there are many gaps between the fibers, the resin filled in the wood surface is sucked between the fibers. Therefore, it was practically extremely difficult to form a sufficient resin film that could block the wooden surface.

[0006] As a medium-quality fiberboard having excellent water resistance, there is also a material to which a large amount of a water-resistant resin such as melamine is added. However, it is hardly used in general because it is expensive. It is a fact.

The present invention has been made in view of such a technical background, and provides a water resistant treatment method capable of improving the water resistance of a woody material such as the above-mentioned medium fiberboard.

[0008]

Means for Solving the Problems In order to achieve the above object, the present invention basically employs a method of filling a kiguchi surface with a resin and sealing the kiguchi surface, while directly applying a resin to the kiguchi surface. In order to prevent the resin from being sucked into the space between the fibers at the time of filling and to form a sufficient film, a pretreatment with the resin is performed prior to filling.

That is, the present invention relates to a method for water-resistant treatment of a wood material having a wood fiber layer exposed on the wood tip surface, wherein a low-viscosity resin liquid is penetrated into the fiber layer exposed on the wood tip surface and cured. /> , The wood fiber around the mouth is coated with resin
After the resin and the fiber have been integrated into a resin state , the kiguchi surface is filled with a water-resistant resin having a relatively higher viscosity than the resin for infiltration, thereby closing the gap between the fibers and the kiguchi. Tree on the surface
The gist of the present invention is a method for water-resistant treatment of woody material, characterized by forming a grease film .

First, a resin infiltration step as a pretreatment will be described. In this step, the wood fibers around the edge of the wood are coated with a resin or the resin and the fiber are integrated into a resin to form a resinized state. The purpose of the present invention is to facilitate and complete the closing of the lip by filling. Suitable examples of the resin liquid used include various solvent-type resin liquids such as a moisture-curable urethane, an acrylic resin, and a silicon resin.

It is necessary to use a low-viscosity resin liquid for facilitating the penetration of the wood fiber layer at the wood opening. Specifically, 10 seconds to 30 minutes with Iwata viscosity cup
It is better to use one with a viscosity of seconds. If the viscosity exceeds 30 seconds, the viscosity may be too strong and the penetration into the fiber layer may be insufficient. Conversely, if the viscosity is less than 10 seconds, the viscosity is too low, and there is a possibility that a sufficient coating or resinification cannot be realized.

The infiltration of the resin solution into the wood fiber layer of the open end can be performed by applying the resin solution to the open end.
As a specific method of the application, for example, a spray method, a roll coater method, a dipping method, and the like can be mentioned. It is preferable to apply the resin liquid to the front and back surfaces around the cut edge simultaneously with the operation of applying the resin liquid to the cut edge in that the water resistance treatment can be more complete.

After the penetration of the resin liquid, the resin is cured by a method such as room temperature curing or heat curing, if necessary . Cal penetration of the resin solution, the curing or, wood fiber layer near the butt surface is resin coating, or a part has become integrated with the resin and the resin state. However, at this stage, the gap between the wood fibers is almost intact, so that this treatment alone is not enough to prevent the infiltration of moisture.

[0014] Then, a step of filling the resin at the tip of the wood is carried out. As the resin used for filling, a resin having water resistance and a tough resin film after curing, such as a urethane-based resin, an acrylic-based resin, and a urea-vinyl acetate-based resin, is preferable. The same type of resin as used for the penetration into the fiber layer in the pretreatment may be used. The viscosity of the resin is relatively higher than the resin for infiltration
Although it required to be those, and E sufficiently filled in the gap between the fibers of the end grain surface, the use of a viscosity sufficient to be closed to the gap rather good, preferably 20 seconds Iwata viscosity cup 90 It is preferable to use a resin having a medium viscosity in seconds.

The method of filling the resin at the tip of the wood is not particularly limited, but it is preferable to use a roll coater method or the like in view of the fact that a resin having a medium viscosity is preferable.

Since the wood fiber layer on the tip side is coated or further resinized by a resin infiltration step as a pretreatment, the resin applied to the tip side in the subsequent resin filling step no longer has a gap between the fibers. The gap is sufficiently filled without being sucked into the space.

Thereafter, the filling resin is cured at room temperature or, if necessary, cured by heating. In the hardened state, a strong film of the filling resin is formed on the lip end surface, thereby preventing intrusion of moisture from the lip end surface. In addition, without performing the pre-treatment, when only the step of filling the resin to the tip surface, as described in the prior art, the resin is absorbed into the gap between the fibers, the gap between the fibers is closed. It is difficult to form a film sufficient to obtain, and it is possible to form a strong resin film by combining this with the preceding resin infiltration step.

In the case where a decorative veneer or a patterned paper is stuck to a wooden material to apply makeup, or in the case of performing a cutting process, the water-resistant treatment of the present invention is applied after applying such makeup or processing. It should be implemented.

[0019]

Next, an embodiment of the present invention will be described.

(Embodiment 1) thickness 5.5 mm × length 100
A moisture-curable urethane resin adjusted to a viscosity of 15 seconds in a viscosity cup is sprayed on the tip of a urea type medium-density fiberboard having a size of 100 mm × 100 mm by spraying at 200 g / m ^2.
Applied. Then, the resin was allowed to cure at room temperature.

Next, 200 g / m ^{2 of} an acrylic urethane resin adjusted to have a viscosity of 30 seconds in a viscosity cup was applied to the above-mentioned cut edge by a roll coater for side application.

Then, the resin was cured by drying at 50 ° C. × 1 hour to obtain a product of the present invention.

(Embodiment 2) A thickness of 0.2 on the front and back surfaces
12mm thick vinyl chloride resin film attached
A urea type particle board of mm × length 100 mm × width 100 mm was prepared.

Then, the particle board was subjected to a water-resistant treatment under the same conditions as in Example 1 to obtain a product of the present invention.

(Comparative Example 1) A medium-density fiberboard of the same material and the same dimensions as those used in Example 1 was used as a sample without water-resistance treatment.

(Comparative Example 2) A particle board having the same material and the same dimensions as those of Example 2 was used as it was as a sample without performing a water-resistant treatment.

(Comparative Example 3) A melamine-type medium-density fiberboard having the same dimensions as that of Example 1 was used as a sample without any water-resistant treatment.

A water resistance test was carried out on the five test samples obtained as described above. The water resistance test was performed under the conditions of immersing in hot water of 70 ° C. for 2 hours and drying at 60 ° C. for 3 hours.

Then, the state of each specimen after completion of the water resistance test was examined. Table 1 shows the results.

[0030]

[Table 1]

As is clear from the above test results, the product of the present invention has a thickness swelling ratio of about 10 to 12% as compared with the comparative products 1 and 2 which are not subjected to the water resistance treatment, and contains a large amount of melamine resin. It can be seen that the sample exhibited a swelling state similar to that of Comparative Example 3 which was excellent in water resistance. Therefore,
According to the present invention, it was confirmed that the water resistance of the woody material can be significantly improved by a simple treatment.

[0032]

According to the present invention, as described above, the present invention relates to a method for water-resistant treatment of a wood material having a wood fiber layer exposed on a wood mouth surface, wherein a low-viscosity resin solution is penetrated into the wood layer exposed on the wood mouth surface ,
Hardened , resin coated wood fiber around the mouth
Or after the resin and fiber are integrated into a resin state, the resin has a higher viscosity than the resin for infiltration
Filled with water-resistant resin to close the gaps between fibers and
A resin film is formed on the mouth surface . Therefore, the resin penetrates into the fiber layer of the kiguchi surface in advance ,
The fibers are made into a coating state by curing , or a resinized state in which the resin and the fibers are partially integrated, so that the resin to be filled thereafter is not sucked into the gap in the fiber layer. In addition, the supplied resin can be effectively used, a strong resin film can be formed on the cut surface with a minimum amount of resin, and the cut surface can be reliably closed with the resin. As a result, it is possible to effectively block the intrusion of moisture from the mouth of the wood, and it is possible to significantly improve the water resistance of the whole wood material.

Further, even if fiber protrusions are present on the wooden surface, since the fibers are resin-coated or resinized in the pretreatment, the danger of absorbing moisture therefrom can be eliminated.

Furthermore, even if moisture intrudes into the interior through pinholes or the like, since the fiber layer around the edge of the wood is resin-coated or resinified, the fibers in that portion swell and moisture is sequentially introduced into the interior. The disadvantages introduced can be avoided.

In addition, while a relatively simple processing step of only filling the opening edge with the filling resin after infiltrating the low-viscosity resin, it is also a low-priced general ordinary material such as a medium fiberboard using a urea resin. A low-water-resistant wood material can be provided with almost the same water resistance as a high-grade wood material using a melamine resin, and a base material of a floor material, a wall material, and the like that requires water resistance. The use of these wood materials can be dramatically expanded.

Furthermore, since the wood surface is treated with resin, the bonding strength of the wood fibers around the wood surface can be improved, and the strength of the whole wood material can be improved. Can also be expected.

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Claims (1)

(57) [Claims] 1. A water-resistant treatment method for a woody material having a wood fiber layer exposed on a wood-mouth surface, wherein a low-viscosity resin solution is penetrated and hardened into the wood layer exposed on the wood-mouth surface, and the wood material around the wood-mouth surface is exposed .
Wood fiber is coated with resin or resin and fiber are
After being made into an integrated resin state , the above
Filled with water-resistant resin with relatively higher viscosity than that of resin
A water-resistant treatment method for woody material, comprising closing a gap between the two and forming a resin film on the lip surface .