JP2014054729A - Wood-resin composite board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wood-resin composite board which is a wooden plate material used for top plates of a table and a desk, or a shelf board of a book shelf or the like, which is light-weight and scarcely produces warpage, further which is excellent in reworkability and versatility when a change in specification occurs, and for which a low-cost raw material is used.SOLUTION: A wood-resin composite board is composed of: a core material 11; two sheets of synthetic resin foamed bodies 12 being identical in material and thickness and respectively adhered and laminated to a front surface and to a rear surface of the core material 11 with an adhesive; two sheets of surface members 13 being identical in material and thickness and respectively adhered and laminated to surfaces of the two sheets of synthetic resin foamed bodies 12 with an adhesive; and two sheets of decorative papers 14 being identical in material and thickness and respectively adhered and laminated to surfaces of the two sheets of surface members 13 with an adhesive.

Description

  The present invention relates to a wooden board used for a table, a top board of a desk, a shelf board of a book shelf, or the like. More specifically, the present invention relates to a wood compound composite board excellent in reworkability and versatility that is light in weight, has little warpage, and does not lose its strength and handleability even when size cuts are made due to specification changes. Is.

  Wooden boards are used for various purposes such as building members such as walls and floors, partitions, doors, blinds, tables, desk tops, and bookshelves. In addition to solid wood that has been cut to the required dimensions from a single log, these boards have been joined together with a solid adhesive to create a single board to reduce manufacturing costs. In general, a laminated board, a medium density fiberboard (MDF), or a particle board formed by crushing a piece of wood and spraying an adhesive and then pressing it is used.

  Further, as an attempt to reduce the weight, as shown in FIG. 2, a ridge formed in a frame shape using a particle board or the like is used as a core material 21, and plywood, MDF, or the like is provided on the front surface and the back surface of the core material 21. A hollow board bonded as the material 23, that is, a so-called flash-structured wood board 20 is widely distributed. However, a plate material used for applications such as a table top, a desk top plate or a book shelf shelf requires a certain degree of strength against the weight applied from above, but the plate member 20 having a flash structure has a hollow portion 21a. Due to the structure, there is a problem that a portion having extremely low strength is formed with respect to the weight from above. In order to compensate for this, a wooden flash panel or the like in which a honeycomb paper core material is spread as an internal space member in a hollow portion is disclosed (for example, see Patent Document 1). In this wooden flash panel, a paper core material or the like is laid in the hollow portion to compensate for the lack of strength, which is one of the problems of the flash structure panel. Also, in this wooden flash panel, by attaching a non-woven fabric between the core material and the back surface material, even when an ultra-thin board is used as the surface material, unevenness such as a paper core material spread in the hollow portion is provided. It is said that it is difficult to come out on the surface and is excellent in decorativeness, and can be suitably used for applications such as folding screens and stands for clause decorations.

  On the other hand, in order to compensate for weight reduction and insufficient strength, instead of the core material used for the plate material of the flash structure, for example, as shown in FIG. A composite board 30 having a three-layer structure (excluding decorative paper) in which a surface material 33 is bonded and sandwiched between the front surface and the back surface of the foam 32 has also been proposed. In this composite board 30, weight reduction is achieved by using a polystyrene foam or the like that is very lightweight and has a desired flexibility at the center, and does not have a hollow portion like a flash-structured plate material. For this reason, the problem that the strength becomes extremely weak in the vicinity of the center of the shelf surface is less likely to occur.

Registered Utility Model No. 3044135 (Claim 1, FIG. 1)

  However, the flash-structured plate material as shown in Patent Document 1 has problems in terms of reworkability and versatility when specifications are changed after being manufactured once. For example, in the flash-structured plate member 20 shown in FIG. 2, when the sheet is cut to a desired size along the line AA, the cut surface is opened as shown in FIG. As described above, when an opening is formed in the cut surface, the strength against the pressure from above and below is greatly reduced near the opening, and deformation due to compression occurs. The problem is that, even in the structure of the wooden flash panel of Patent Document 1 described above, even if the core material is spread in the hollow portion, one of the four pieces of cocoons is missing, so a decrease in strength is avoided. I can't. Further, when the plate material having the opening after the size cut is fixed as a shelf on a book shelf or the like, the opening cannot be screwed or nailed for fixing.

  On the other hand, in the composite board 30 having a three-layer structure having a foam shown in FIG. 4, the foam occupies the center of the plate material when viewed from the side. Since the foam is a member having a certain degree of flexibility, it cannot be stably fixed even if a nail or the like is driven from the side to the center. For this reason, the composite board 30 having the three-layer structure has a very poor handling property in terms of fixing by screwing or nailing even when the size is not cut.

  An object of the present invention is a plate material mainly made of a low-cost wooden material used for a table top, a table top or a shelf of a book shelf, etc., which is lightweight, has little warpage, and has undergone a specification change. The object is to provide a woody compound composite board with excellent reworkability and versatility.

  As shown in FIG. 1, the first aspect of the present invention is that the core material 11 and two sheets of the same material and the same thickness that are bonded and laminated with an adhesive on each of the front surface and the back surface of the core material 11. Synthetic resin foam 12, two surface materials 13 of the same material, the same thickness, and two surface materials 13 bonded to each of the surfaces of the two synthetic resin foams 12 with an adhesive. This is a woody compound composite board composed of two decorative papers 14 of the same material and the same thickness, which are bonded to each of the surfaces with an adhesive.

  The second aspect of the present invention is an invention based on the first aspect, characterized in that the synthetic resin foam 12 has an expansion ratio of 5 to 60 times.

  The third aspect of the present invention is an invention based on the first or second aspect, wherein the synthetic resin foam 12 is made of expanded polystyrene having an expansion ratio of 10 to 40 times.

  A fourth aspect of the present invention is an invention based on the first to third aspects, in which the core 11 has a thickness of 3 to 10 mm, and the synthetic resin foam 12 has a thickness of 3 to 40 mm. The thickness of the surface material 13 is 2 to 5 mm, the thickness of the decorative paper 14 is 0.1 to 0.5 mm, and the total thickness is 12 to 100 mm.

  The woody chemical composite board according to the first aspect of the present invention is made of two synthetic resins of the same material and the same thickness, which are bonded to each other with an adhesive on the core and the front and back surfaces of the core. Adhesives are applied to the surfaces of the foam and two synthetic resin foams with the same material, two surface materials having the same thickness, and two surface materials adhered and laminated to each surface of the synthetic resin foam. It consists of two decorative papers of the same material and the same thickness that are bonded and laminated. By having such a structure, the woody chemical composite board of the present invention can achieve a significant weight reduction, less warpage, and a stable strength against the weight from above. In addition, no opening is generated unlike a plate material having a flash structure even if it is cut at any position. For this reason, even if the size of the board is cut when the specification is changed, the strength is not significantly reduced at the specific portion. In addition, no matter what size you cut, the core will always be placed in the center, so there will be no inconveniences such as screwing and nailing, and there will be changes in specifications. Excellent in reworkability and versatility. Moreover, the effect that the sticking of an edge tape to an edge part becomes easy is acquired.

  In the woody chemical composite board of the third aspect of the present invention, the synthetic resin foam is made of expanded polystyrene having an expansion ratio of 10 to 40 times. Expanded polystyrene having an expansion ratio in the above range has an appropriate elasticity and a small specific gravity, so that a desired strength can be obtained as a whole board and the weight can be further reduced. In addition, soundproofing and sound insulation effects can be obtained.

It is a lamination sectional view showing the woody chemical product composite board of the embodiment of the present invention. It is a perspective view which shows the board | plate material made from wood of a general flash structure. It is a figure which shows a piece when the board | plate material of FIG. 2 is cut | disconnected in two by the AA line. It is a perspective view which shows the laminated board of 3 layer structure which has arrange | positioned the foam in the center. It is explanatory drawing of the strength test in an Example.

  Next, an embodiment for carrying out the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the woody chemical composite board of the present invention has two cores 11 and the same material and the same thickness, which are bonded and laminated with an adhesive on the front surface and the back surface of the core material 11, respectively. Synthetic resin foam 12, two surface materials 13 of the same material, the same thickness, and two surface materials laminated together by bonding with an adhesive to the surfaces of the two synthetic resin foams 12. It is composed of two decorative papers 14 of the same material and the same thickness, which are bonded and laminated to each of the 13 surfaces.

  Examples of the core material 11 include plywood, MDF, and particle board. Among these, it is preferable to use plywood or MDF because screwing is easy. Moreover, it is preferable that the thickness of the core material 11 shall be the range of 3-10 mm. If the thickness of the core material 11 is less than the lower limit value, there is a tendency that problems such as insufficient strength and a decrease in screw holding force tend to occur. On the other hand, if the thickness exceeds the upper limit, it is not preferable because sufficient weight reduction cannot be achieved.

  Examples of the synthetic resin foam 12 include thermoplastic polymer foams such as expanded polystyrene and expanded polyethylene, polypropylene resin, acrylic resin, vinyl chloride resin, zinc white, lead white, lithopone, titanium dioxide, precipitated barium sulfate, Examples thereof include a synthetic resin plate material produced by extrusion molding by kneading an inorganic pigment such as kaolin clay or barite or an organic pigment such as plastic pigment, and the expansion ratio is preferably 5 to 60. Among these, as the synthetic resin foam 12 constituting the woody chemical composite board 10 of the present invention, foamed polystyrene having a foaming ratio of 10 to 40 is particularly preferable. For example, in the case of foamed polyethylene, those with a large expansion ratio are too elastic, while those with a low expansion ratio tend to have a specific gravity that is too high. Adjustment is somewhat difficult. On the other hand, foamed polystyrene has a high restoring force, and foamed polystyrene having a foaming ratio in the above range is preferable because the specific gravity can be reduced while maintaining appropriate elasticity. Moreover, it is preferable that the thickness of the synthetic resin foam 12 is 3 to 40 mm. The thickness of the synthetic resin foam 12 is preferably larger than the thickness of the surface material 13 in terms of weight reduction.

  Examples of the adhesive applied to the synthetic resin foam 12 include a vinyl acetate adhesive, an aqueous vinyl urethane adhesive, a natural rubber adhesive, a hot melt adhesive, and the like. Among these, a vinyl acetate-based adhesive or a water-based vinyl urethane-based adhesive is particularly preferable for reasons such as a balance between adhesive strength and cost or availability of simple equipment. Moreover, in order to improve adhesive force, it is preferable to use what mixed the solvent in the ratio of 0.5-5 mass%. Examples of the solvent include toluene, xylene, hexane, acetone or ethyl acetate.

  As the surface material 13, plywood, MDF, HDF (High Density Fiberboard), particle board, or the like may be used. Among these, since it is excellent in surface smoothness and intensity | strength and is excellent also in cost, it is especially preferable to use MDF or a plywood. Moreover, it is preferable that the thickness of the surface material 13 is 2-5 mm.

  Examples of the decorative paper 14 include printing paper, synthetic paper, melamine paper, and vinyl chloride sheet. Among these, printing paper is particularly preferable because of excellent processability and cost. The thickness of the decorative paper 14 is preferably 0.1 to 0.5 mm.

  Examples of the adhesive that bonds the surface material 13 and the decorative paper 14 include a vinyl acetate adhesive, a water-based vinyl urethane adhesive, a natural rubber adhesive, or a hot melt adhesive. Among these, a vinyl acetate adhesive or a hot melt adhesive is particularly preferable because of excellent adhesion workability.

  As described above, in the woody chemical composite board of the present invention, the weight can be significantly reduced by the above configuration, and a stable strength against the weight from above can be obtained. In addition, when the specification is changed, even if size cutting is performed, the strength does not significantly decrease at a specific portion, and there is no inconvenience that screwing or nailing cannot be performed.

  Further, in the woody chemical composite board of the present invention, the two synthetic resin foams 12 bonded to the front surface and the back surface of the core material 11, and 2 bonded to the surfaces of these synthetic resin foams 12. The two surface papers 13 and the two decorative papers 14 to be bonded to the surface of the surface material 13 are composed of members of the same material and the same thickness. As a result, in FIG. 1, the material, structure, and size of the upper half portion and the lower half portion from the center of the core material 11 are symmetric. By configuring in this way, it is possible to greatly prevent the occurrence of warping due to changes in the usage environment such as humidity or temperature. The total thickness of the woody chemical composite board is preferably in the range of 12 to 100 mm because secondary processing is easy.

  Then, the manufacturing method of this woody chemical composite board is demonstrated.

  First, a core material 11, a synthetic resin foam 12, a surface material 13, and a decorative paper 14 constituting the woody chemical composite board of the present invention are prepared. The synthetic resin foam 12, the surface material 13, and the decorative paper 14 are each prepared with two sheets of the same material and thickness. Then, the two decorative papers 14 are bonded in advance to the respective surfaces of the surface material 13 using an adhesive. Examples of the adhesive include a vinyl acetate adhesive, a water-based vinyl urethane adhesive, and a hot melt adhesive.

  And the adhesive agent is apply | coated to the front side surface and back side surface except each side surface of the two synthetic resin foams 12 prepared. Examples of the adhesive include the above-described vinyl acetate-based adhesive, aqueous vinyl urethane-based adhesive, hot-melt adhesive, and the like. For reasons such as adhesiveness and cost balance or availability of simple equipment, vinyl acetate-based adhesive is used. It is particularly preferred to use an agent or an aqueous vinyl urethane adhesive. When using these adhesives, the solvent is mixed and diluted at a ratio of 0.5 to 5% by mass (the ratio of the solvent when the total of the adhesive and the solvent is 100% by mass) before coating. Keep it. Further, the application of the adhesive to the synthetic resin foam 12 is preferably performed by a method such as a roll coater because it is excellent in coating workability and can be uniformly applied.

  Next, these members are bonded and bonded to each other by crimping these members at room temperature of 5 to 40 ° C. using, for example, a cold press molding machine. First, a set of laminated members prepared by aligning the above members so that the decorative paper, the surface material, the synthetic resin foam, the core material, the synthetic resin foam, the surface material, and the decorative paper are laminated, 10-30 sets of laminated members are placed. At that time, a polyolefin film or the like is inserted in order to prevent the adhesive from leaking between the sets of laminated members. Next, the upper press plate is lowered, and these members are pressure-bonded by preferably pressing at a pressure of 0.1 to 0.5 MPa for 5 minutes to 24 hours. If the pressure at this time is less than the lower limit, the pressure bonding between the members becomes insufficient, and delamination or swelling may occur, which is not preferable. On the other hand, if the upper limit is exceeded, the total thickness may become too thin, which is not preferable. In addition, when the pressurization time is less than the lower limit value, the pressure-bonding between the members becomes insufficient, and adhesion failure may occur. On the other hand, even if the pressurization time exceeds the upper limit value, the adhesive force is not improved further, and workability, work efficiency, and the like are lowered, which is not preferable.

  After the respective members are pressure-bonded by press molding, the formed board material is taken out from the press molding machine, whereby the woody chemical composite board of the present invention is obtained.

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
First, a sheet of 4 mm thick plywood (manufactured by Shin Yang Plywood) was prepared as a core material, and a foamed polystyrene (made by Dow Chemical Co., Ltd.) having a thickness of 5 mm and an expansion ratio of 18 times as a synthetic resin foam. (Trade name: wood rack panel), MDF board (manufactured by Daiken Kogyo Co., Ltd.) having a thickness of 3 mm as a surface material, and two printing papers having a thickness of 0.2 mm were prepared as decorative paper. The dimensions other than the thickness of these members were all 91 cm in width and 182 cm in length. In addition, as an adhesive, an aqueous vinyl urethane-based adhesive prepared by adding and mixing a crosslinking agent (AX-200 manufactured by Koyo Sangyo Co., Ltd.) at a ratio of 5% by mass to the main agent (KR-134 manufactured by Koyo Sangyo Co., Ltd.) is prepared. Then, toluene as a solvent was mixed and diluted at a ratio of 0.5% by mass.

  Next, using these members, a woody chemical composite board having the laminated structure shown in FIG. 1 was produced. Specifically, first, an adhesive prepared by mixing and diluting the solvent was applied to the front surface and the back surface of the two prepared synthetic resin foams 12 except for the side surfaces by a roll coater. In addition, a printing paper was pasted on one surface of the surface material 13 as a decorative paper 14 with a hot melt adhesive in advance. Next, between the upper press plate and the lower press plate provided in the cold press molding machine (manufactured by Kobayashi Machine Industry Co., Ltd.), the prepared members are made of decorative paper 14, surface material 13, and synthetic resin foam 12. A set of laminated members prepared so that the core material 11, the synthetic resin foam 12, the surface material 13, and the decorative paper 14 were arranged in the order of lamination was set, and 20 sets thereof were placed. At that time, a polyethylene film was inserted in order to prevent the adhesive from leaking between the sets of laminated members.

  Finally, the upper press plate of the press molding machine was lowered and pressed at room temperature for 12 hours at a pressure of 0.2 MPa, so that these members were pressure-bonded to obtain a woody chemical composite board 10. This composite board was referred to as Example 1.

<Example 2>
Similar to Example 1, except that MDF board was used as the core material instead of plywood, and particle board (manufactured by Iris Ohyama Co., Ltd.) was used as the surface material instead of MDF board. Got the board. This composite board was referred to as Example 2.

<Example 3>
In the same manner as in Example 1 except that foamed polystyrene having a foaming ratio of 24 times was used as the synthetic resin foam, and plywood was used as the surface material instead of the MDF board, the woody chemical composite board was obtained. Obtained. This plate was designated as Example 3.

<Example 4>
A woody chemical composite board is obtained in the same manner as in Example 1 except that foamed polystyrene having a foaming ratio of 11 times is used as the synthetic resin foam and that an MDF board is used as the core material instead of plywood. It was. This plate was designated as Example 4.

<Comparative Example 1>
First, a 4 cm wide, 174 cm, 1.4 cm thick laver obtained by cutting a particle board with a running saw, and a 4 cm wide, 91 cm long, 1.4 cm thick laver material, respectively. Two were prepared. These were joined by a tucker to obtain a core material 21 having a hollow portion shown in FIG. Further, as the surface material 23, two MDF boards having a width of 91 cm, a length of 182 cm, and a thickness of 0.3 cm were prepared.

  Next, using these members, a wooden board 20 made of a flash structure shown in FIG. 2 was produced. Specifically, first, an adhesive mixed with the solvent used in Example 1 is applied to the front surface and the back surface of the core material 21 excluding the hollow portion 21a and the side surfaces with a roll coater, and then the core material is cold-pressed. 21 and the surface material 23 were bonded and bonded to obtain a wooden board 20 made of a flash structure. This plate was designated as Comparative Example 1.

<Comparative example 2>
First, one sheet of expanded polystyrene (trade name: Wood Rack Panel, manufactured by Dow Chemical Co., Ltd.) having a width of 91 cm, a length of 182 cm, a thickness of 1.4 cm, and an expansion ratio of 18 was prepared. Further, two MDF boards having a width of 91 cm, a length of 182 cm, and a thickness of 0.3 cm were prepared as surface materials.

  Next, the laminated board 30 of the three-layer structure shown in FIG. 4 was obtained using these members. Specifically, first, an adhesive prepared by mixing the solvent used in Example 1 was applied to the front surface and the back surface of the foam 32 except for the side surfaces by a roll coater. Next, between the upper press plate and the lower press plate provided in the cold press molding machine used in Example 1, the prepared members are arranged in the stacking order of the surface material 33, the foam 32, and the surface material 33. Was placed as follows.

  Finally, the upper press plate was moved down and pressurized at a pressure of 0.2 MPa at room temperature for 12 hours, so that these members were pressure-bonded to obtain a laminated plate 30. This plate was designated as Comparative Example 2.

<Comparative Example 3>
As in Comparative Example 1, except that a 14 mm thick paulownia laminated material was used as a core material and MDF having a 0.2 mm thick printed paper stuck as a decorative paper 14 was used as a surface material. A plate was obtained. This plate was designated as Comparative Example 3.

<Comparison test and evaluation>
The plate materials obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated for specific gravity and strength. These results are shown in Table 2 below.

  (1) Specific gravity: Density was measured under the conditions of a temperature of 23 ° C. and a relative humidity of 50% RH, and this was defined as the specific gravity.

  (2) Strength: An equally distributed load test shown in FIG. 5 was performed using a plate piece obtained by size-cutting the plate material obtained in each of Examples 1 to 4 and Comparative Examples 1 to 3 as a test piece. Specifically, according to the acceptance criteria by fixture manufacturer A, a plurality of weights of the same weight are arranged at equal intervals on the surface of the test piece, and the load is continuously applied for 7 days at a pressure of 1.96 kPa. added. About the said test piece, the deflection amount immediately after a load and the deflection amount immediately after the load removal after progress for 7 days were measured, respectively. Moreover, it evaluated about the presence or absence of shape abnormality by visual observation. In addition, the acceptable reference value of the deflection amount was set to 7.9 mm or less immediately after the load, and 2.37 mm or less immediately after the load was removed after 7 days. In the table, “A” indicates a case where no abnormal shape such as a crack was observed in the test piece, and “B” indicates a case where a slight crack was confirmed in the test piece.

  As is clear from Tables 1 and 2, when Examples 1-4 and Comparative Examples 1-3 are compared, the plate material of Examples 1-4 has a smaller specific gravity and is lighter than the plate material of Comparative Example 3. I understand that. In addition, the plate material of the flash structure of Comparative Example 1 and the plate material without the core material centered on the expanded polystyrene of Comparative Example 2 have a small specific gravity and light weight, and have passed the acceptance criteria, but are bent immediately after loading. The amounts were very large, 4.67 mm and 5.95 mm, respectively, and the strength after cutting was greatly reduced. In particular, the plate material of Comparative Example 2 did not return to its original deformed shape after removing the load, resulting in an extremely large amount of deflection. Moreover, in the board | plate material of the flash structure of the comparative example 1, a crack is confirmed partially in the board | plate material immediately after the load removal after 7-day progress, and it turns out that intensity | strength is inferior also from the surface of durability.

  On the other hand, although the plate materials of Examples 1 to 4 are lighter than the plate material of Comparative Example 3, both the deflection amount immediately after the load and the deflection amount immediately after the load removal after the lapse of 7 days are both cores. It shows the same value as the plate material of Comparative Example 3 using a very expensive paulownia laminated material as the core material, and there is no shape abnormality due to load, and stable strength is obtained even if size cutting is performed. It was confirmed that

  It can be used for building members such as walls and floors, partitions, doors, blinds, tables, desk tops, and bookshelves.

10 Wood Compound Composite Board 11 Core Material 12 Synthetic Resin Foam 13 Surface Material 14 Decorative Paper

Claims (4)

Core material (11),
Two synthetic resin foams (12) having the same material and the same thickness, which are bonded and laminated to each of the front surface and the back surface of the core (11),
Two surface materials (13) of the same material and the same thickness, which are bonded and laminated to each surface of the two synthetic resin foams (12) with an adhesive;
A woody chemical composite board comprising two decorative papers (14) having the same material and the same thickness, which are bonded and laminated to each surface of the two surface materials (13) with an adhesive.   2. The woody compound composite board according to claim 1, wherein the synthetic resin foam (12) has an expansion ratio of 5 to 60 times.   The woody chemical composite board according to claim 1 or 2, wherein the synthetic resin foam (12) is made of expanded polystyrene having an expansion ratio of 10 to 40 times.   The core material (11) has a thickness of 3 to 10 mm, the synthetic resin foam (12) has a thickness of 3 to 40 mm, and the surface material (13) has a thickness of 2 to 5 mm. The woody chemical composite board according to any one of claims 1 to 3, wherein the decorative paper (14) has a thickness of 0.1 to 0.5 mm and a total thickness of 12 to 100 mm.

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