JPH08224708A - Architectural material and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a warp- and twist-free architectural material which demonstrates a high bending strength and outstanding surface properties and size stability despite its light weight by increasing the specific gravity of only the front and rear of a base material to form a hard layer without increasing the entire specific gravity of the base material in the architectural material coated on the surface using a wooden material as a base material. CONSTITUTION: A wooden material with a content of moisture adjusted to a level below a fiber saturation point, is sandwiched between heating plates, then is thermally compressed at temperature higher than the softening point of cellulose which is the crystal component of the wooden material and higher than the softening point temperature with a content of moisture after the adjustment of a non-crystal component, and is decompressed and cooled. Thus the wooden material is obtained which has a hard layer 2 consolidated on both front/rear of the wooden material. In addition, a decorative material 5 is attached to the surface of the consolidated material as a base material 1 through an adhesive layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building material in which a decorative material is attached to the surface of a wood material through an adhesive and a method for producing the same.

[0002]

2. Description of the Related Art Wall materials, floor boards, ceiling boards, stair treads, stair side boards, shelves, counters, door materials, frame materials, opening members, construction materials and the like are used for various construction materials such as wood materials, particularly wood. The solid sawed wood, or laminated wood, plywood, particle board, or other substrate surface to which a decorative material such as decorative paper or veneer is attached via an adhesive is used.

On the other hand, it has been conventionally proposed to heat-compress and consolidate a wood material. Consolidation by heat and compression of the wood material according to the conventional method is performed in a wet state of the wood material, or by humidifying it in a steam atmosphere so that the wood material has a high water content.

[0004] In this method, since the compaction is carried out by heating and compression at a high water content, that is, in the state where a large amount of water is present in the wood material, the water is a plasticizer, especially hemicellulose, lignin, etc. in the main components of wood. It has a great effect as a plasticizer on the non-crystalline components of and has a softening point of 60
It lowers the temperature to about 0 ° C and increases the plasticity of the wood material.

[0005]

In the above conventional construction board, when a softwood material is used for the substrate, there is a difference in specific gravity between the spring wood part and the autumn wood part, so that the adhesive There is a problem that the amount of suction is different, the adhesive strength of the decorative material varies, and wrinkles and swelling of the decorative material easily occur.

In the case of a hardwood substrate, since the conduit groove is large and porous, the adhesive strength is reduced due to bridging of the adhesive in the conduit groove portion, or conversely, when the adhesive is depressed in the conduit groove portion. The same as above, wrinkles and swelling on the decorative material,
There is a problem that a depression or the like is likely to occur.

Therefore, in order to reduce the difference in the specific gravity of the surface of the softwood material or to fill the conduit groove in the hardwood material to form a smooth surface, the surface of the substrate is strengthened and smoothed by a sealer treatment or a sealing treatment. After that, the adhesive was applied to attach the decorative material.

However, the need for pretreatment prior to the application of the adhesive in this way complicates the process and requires strict control over the application amount and drying, so that production And the cost was increased.

In addition, since the dimensional change rate in the width, length and thickness directions due to the water absorption and release of the wood itself is large in the wood material, when a decorative material is attached to the surface with an adhesive, The difference in moisture absorption between the front and back causes imbalance, resulting in warpage and twist, and wrinkles, swelling, fine cracks, and peeling of the cosmetic material due to the warpage and twist. In order to prevent this, moisture-proof coating such as moisture-proof coating or applying a moisture-proof sheet is applied to the surface of the wooden material, but like the above, productivity decline and cost increase due to the complicated process are unavoidable. It was

On the other hand, in the consolidation treatment of the wood material by the above-mentioned conventional method, the wood material is heated and compressed in a high water content state. It acts as a force to restore the consolidated state, and it is difficult to maintain the consolidated state together with the springback phenomenon due to decompression. Further, particularly in a wood material having a low specific gravity, the high steam pressure may be released in an instant, so that puncture (delamination) may occur.

In order to prevent the release of the high vapor pressure, it is conceivable to cool in the pressed state, but the productivity is extremely low and the cost is greatly increased.

Further, according to the above-mentioned prior art, even if the compacted state can be maintained, the whole wooden material in the high water content state is compacted, so that it becomes a high specific gravity wooden material. Will end up.

[0013]

SUMMARY OF THE INVENTION The present invention was devised with the object of solving the problems of the above-mentioned prior art, in which hard wood layers, which are compacted on both front and back sides by heat-compressing a wood material, are provided. The building material is characterized in that a decorative material is attached to at least the surface of the compacted material as a base material via an adhesive.

Further, the building material according to the present invention comprises, as a base material, a consolidated material obtained by forming consolidated hard layers on both front and back surfaces of a wooden material having a water content adjusted to a fiber saturation point or less by heat compression. It is characterized in that a decorative material is adhered to at least the surface thereof via an adhesive.

In the method for producing a building material according to the present invention, a wood material having a water content adjusted to a fiber saturation point or lower is sandwiched between hot plates, and the temperature is not lower than the softening point temperature of cellulose which is a crystalline component of the wood material. And by heating and compressing at a temperature equal to or higher than the softening point temperature in the adjusted water content of the amorphous component, and then decompressing and cooling, a consolidated material having consolidated hard layers on both front and back surfaces of the wood material. And a decorative material is attached to at least the surface of the consolidated material via an adhesive.

As the wood material used as the substrate of the building material of the present invention, solid wood, solid sawn wood, or laminated wood, laminated veneer, plywood, particle board, fiber board and the like are used. As the wood materials, both softwood materials and hardwood materials can be used, and particularly soft materials and materials with low specific gravity are preferably used.

These wood materials are dried before or after sawing to adjust the water content below the fiber saturation point. The water content below the fiber saturation point here is preferably 35%.
The following water contents are meant.

The wood material whose water content is adjusted below the fiber saturation point is inserted between the hot plates of a hot press machine to which a thickness control jig generally called a distance bar for controlling the distance between the upper and lower hot plates is attached. It

As the thickness controlling jig between the heating plates, a jig having a thickness of 80 to 95%, more preferably 82 to 92% of the thickness of the wood material is used. In other words, the thickness regulating jig is attached so that the compressibility of the wood material is 5 to 20%, more preferably 8 to 18%.

If the compressibility of the wood material is less than 5%, the compaction on both the front and back surfaces becomes insufficient, and the strength required for the hard layer cannot be obtained. Conversely, the compressibility of wood is 20
%, The front and back surfaces will be sufficiently consolidated to obtain the required strength as a hard layer, but the overall specific gravity will increase, leading to an increase in weight, and giving an excessive compression rate is a loss of raw material. Is large, the yield is reduced, which causes an increase in cost, which is not preferable.

The compressibility can be arbitrarily selected within the above range depending on the wood species used, the specific gravity of the wood itself, the surface hardness to be obtained, etc., and the thickness corresponding to the compressibility. Set the control jig.

The wood material inserted between the upper and lower hot plates of the hot press machine to which the thickness regulating jig is attached is heated and compressed by hot pressing, and is hardened on both front and back surfaces to form a hard layer.

The hot pressing is carried out at a hot pressing temperature which is equal to or higher than the softening point temperature of cellulose, which is a crystalline component of the wood material, and higher than or equal to the softening point temperature of the amorphous component in the adjusted water content. Be seen.

The pressing time and the pressing pressure are arbitrarily set according to the specific gravity, softness, etc. of the wood material used,
Since the above-mentioned thickness regulating jig is used to obtain the required compression rate during pressing, the pressing time is 3 to 15 minutes and the pressing pressure is 5 to 25 minutes.
It is preferably set to kg / cm ² .

The wood material heated and compressed between the upper and lower hot plates of the hot press machine is gradually softened and compacted by the pressing force from the front and back surfaces in direct contact with the hot plate toward the center. Since the water content is adjusted to a low water content below the fiber saturation point, heat transfer is relatively slow, and only the front and back parts of the wood material are consolidated. In this way, the temperature of the wood material itself does not rise even during hot pressing, so that the wood material is easily cooled by subsequent decompression. Moreover, the fibrous cellulose remains in the wood tissue without being softened by heat, and the softened and melted hemicellulose and lignin act as an adhesive to the cellulose when heated and pressed, so that the solution after hot pressing and pressing Springback of the wood material due to the pressure is minimized, and consolidated hard layers are formed on both front and back surfaces.

The hardness of the hardened layer is JIS Z
4.5k in the method of testing hardness of wood according to 2007
It is preferably gf / mm ² or more. Hard layer is 4.
If it is less than 5 kgf / mm ² , the impact resistance of the surface is insufficient and scratches are likely to occur, and since the compaction is insufficient, the bending strength of the material itself is not improved and the material is hydrophobic. Since the swelling rate and the water absorption rate cannot be reduced, dimensional stabilization cannot be achieved.

The thus-obtained compacted material having hard layers on both front and back surfaces is used as a base material, and an adhesive is applied to at least the surface of the material using a coating device such as a roll coater or a spreader. As the adhesive, vinyl acetate resin-based, urea resin-based, melamine resin-based, phenolic resin-based, acrylic resin-based, urethane resin-based, synthetic resin-based adhesive such as isocyanate or its modified adhesive is preferably used, These are used alone or as a mixed adhesive in which they are arbitrarily mixed. Further, as the adhesive, an adhesive that is transparent or becomes transparent when cured, or a colored adhesive to which a coloring agent is added if necessary is used.

The decorative material is placed on the adhesive-coated surface of the base material, and is pressed by a pressing device such as a laminating device, a vacuum press, a hot press, a cold press or the like, so that the decorative material is attached. As the decorative material, any of decorative paper, decorative synthetic resin sheet, veneer, veneer provided with a backing material, and the like can be used.

In the surface hard layer of the base material, if necessary, fine grooves can be formed on the surface by wire brushing, sanding or the like. The fine grooves increase the surface area of the hard layer, and the anchoring effect due to it increases, so
To improve the adhesive force of the decorative material provided on the surface of the hard layer.

[0030]

The softening point temperature of cellulose, which is a crystalline component in wood, is 200 to 250 ° C regardless of the water content of wood.
However, the softening point temperature of hemicellulose and lignin, which are non-crystalline components, greatly changes depending on the water content of wood, and the softening point temperatures of hemicellulose and lignin in an absolutely dry state are about 180 ° C and about 150 ° C, respectively. However, at a water content of 35% which is the fiber saturation point of the wood material, the softening point temperature decreases to around 60 ° C. That is, unlike cellulose, which is substantially non-plastic, hemicellulose and lignin are plasticized by the water contained in the wood material acting as a plasticizer even at a fiber saturation point or lower.

Therefore, for example, the fiber saturation point of 3
In the case of a wood material adjusted to have a water content of 5%, the heat-pressing temperature in the range of about 60 to about 200 ° C. causes the cellulose, which is a crystalline component, to be hardly softened and to be amorphous in tissue cells. The components hemicellulose and lignin can be heat-softened.

By heating and compressing a wood material having a low water content below the fiber saturation point at such a temperature, only a portion near the front and back of the wood material is consolidated to form a hard layer.

A decorative material is adhered onto the hard layer via an adhesive to obtain the building material of the present invention.

[0034]

EXAMPLE FIG. 1 shows a schematic structure of a building material according to the present invention. Hard woods 2, 2 are formed by consolidation on both front and back surfaces of a wood base material 1, and an adhesive layer 4 is formed on one surface thereof. The decorative material 5 is attached via the.

As an example of the substrate 1, a thickness of 30 mm,
Width 150 mm, length 100 mm, overall specific gravity of about 0.5 solid Agatisu sawwood, low water content below the fiber saturation point (19 ~
21%) and then inserted between the hot plates of a hot press equipped with a 25 mm thickness control jig, the hot plate temperature is 160 ° C., the pressing pressure is 10 kgf / cm ² , and the pressing time is 15
When the product was heated and pressed under the condition of 1 minute, the obtained thickness was 25
Approximately 8 to 10 m from the front and back of compressed solid wood of mm
a hard layer 2 having a specific gravity of 0.6 to 1.0 in a thickness range of m,
2 was formed, and the specific gravity of the inner central portion 3 was almost constant at the overall specific gravity (about 0.5) before the consolidation treatment. Further, the hardness of the hard layer is 4.5 to 16.5 kgf / mm ² , and the material hardness before the consolidation treatment is 2.6 to 3.4 kgf / m.
It was remarkably improved as compared with m ² .

[0036]

According to the present invention, the hard layer is formed by increasing the specific gravity of only the front and back of the wood material without increasing the overall specific gravity.
Since the surface hardness is improved and the balance between the front and back is maintained, warping and twisting can occur even if a decorative material is attached to only one surface via an adhesive. Absent.

The hard layers on the front and back of the wood material as the base material are mainly hemicellulose, which is an amorphous component in the wood material,
Since lignin is formed by being softened and melted and then hardened to a high density that is compressed, it becomes a hydrophobic film, which reduces the swelling rate and water absorption rate together with the decrease in hydrophilicity due to consolidation. It is possible to greatly improve the dimensional stability of the wood material.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a building material according to the present invention.

[Explanation of symbols]

 1 Base Material 2 Hard Layer 3 Center Part 4 Adhesive Layer 5 Decorative Material

[Procedure amendment]

[Submission date] April 26, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

[0015] In the method of manufacturing building materials according to the present invention, the water content adjusted woody material below the fiber saturation point sandwiched between hot plates, equal to or lower than the softening point temperature of the cellulose is a crystalline component of the wood material And by heating and compressing at a temperature equal to or higher than the softening point temperature in the adjusted water content of the amorphous component, and then decompressing and cooling, a consolidated material having consolidated hard layers on both front and back surfaces of the wood material. And a decorative material is attached to at least the surface of the consolidated material via an adhesive.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

The hot pressing is performed by setting the hot pressing temperature to a temperature not higher than the softening point temperature of cellulose which is a crystalline component of the wood material and not lower than the softening point temperature of the amorphous component in the adjusted water content. Be seen.

Claims (5)

[Claims] 1. A base material is a consolidated material having hardened layers on both front and back surfaces of a wood material that is heat-compressed, and a decorative material is attached to at least the surface thereof via an adhesive. Characteristic building material. 2. A consolidated material, which comprises a consolidated hard layer formed on both front and back surfaces by heat compression of a wood material whose water content is adjusted to a fiber saturation point or lower, is used as a base material, and an adhesive is provided on at least the surface thereof. A construction material, characterized in that a decorative material is adhered through the material. 3. The hardness of the hard layer is 4.5 kgf / m.
The construction material according to claim 1 or 2, wherein the construction material is m ² or more. 4. A water content of a wood material, the water content of which has been adjusted to a fiber saturation point or less, is sandwiched between hot plates so as to be above the softening point temperature of cellulose, which is a crystalline component of the wood material, and which is an amorphous component after the adjustment. Heat compression at a temperature above the softening point temperature, then decompressing and cooling to obtain a consolidated material having consolidated hard layers on both front and back surfaces of the wood material, and at least the surface of the consolidated material. A method for manufacturing a building material, which comprises applying a decorative material to an adhesive via an adhesive. 5. The method for manufacturing a building material according to claim 4, wherein after forming the fine grooves on the surface of the hard layer of the consolidation material, the decorative material is attached via the adhesive.