WO2006103992A1

WO2006103992A1 - Composition for forming woody coating layers and woody parts

Info

Publication number: WO2006103992A1
Application number: PCT/JP2006/305704
Authority: WO
Inventors: Shinji Oogoe; Hidetoshi Omura; Yoshiomi Horiguchi
Original assignee: Sekisui Jushi Kabushiki Kaisha
Priority date: 2005-03-25
Filing date: 2006-03-22
Publication date: 2006-10-05
Also published as: KR101182622B1; CN101146860A; JP5209961B2; HK1117556A1; KR20080002771A; JPWO2006103992A1; CN101146860B

Abstract

A composition for forming a woody coating layer, capable of forming a layer which hardly peels off even after long-term use; and woody parts whose woody coating layers hardly peel off substrates even after long-term use. Use of an α-olefin/unsaturated carboxylic acid copolymer as the base resin (11) brings about high adhesiveness to a substrate, while the blending of wood meal (12) gives woodiness to the surface of the coating layer (1). Further, the coating layer (1) easily causes cohesive failure in the application by virtue of the incompatibility of the wood meal (12) with the base resin (11), resulting in a layer which hardly peels off even after long-term use.

Description

Specification

WOODEN COATING LAYER COMPOSITION AND WOODEN MOLDED ARTICLE

Technical field

[0001] The present invention relates to a composition for forming a coating layer having a wood texture on the outer surface, and a wood-based molded article having a wood texture on the outer surface.

Background art

[0002] Various compositions have been disclosed for providing a wooden texture on the outer surface by coating or painting by thermoforming, or molded articles having a wooden texture. A molded article formed with a surface layer that forms an outer surface and an inner layer that forms the inside of the surface layer, and the inner layer has at least a mass similar to the physical properties of natural wood It is provided with an internal resin layer formed by extruding the resin, and the surface layer is a powder obtained by grinding a pulverized powder obtained by pulverizing a cellulose material to increase the bulk specific gravity. The outer peripheral surface of the powder In addition, a fixed surface particle having a diameter smaller than that of the powder particle is fixed to form a fixed particle, and a resin and a pigment are mixed and melted in the fixed particle, and formed on the outside of the internal resin layer. A wood-like product formed by fixing is disclosed (for example, Patent Document 1).

[0003] Also, as a result of painting, a coating material in which silica gel and Z or wood powder are mixed in the coating material, and a building board coated with the same are disclosed (for example, Patent Document 2).

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 8-207111

Patent Document 2: Japanese Unexamined Patent Publication No. 2003-128999

Disclosure of the invention

Problems to be solved by the invention

[0005] However, in conventional wood-based molded products such as those described in Patent Documents 1 and 2, if a part of the coating layer is scratched in use over a long period of time, peeling will occur from the scratched part. It progressed quickly, and there was a concern that the coating layer might peel off the object force of the coating over a long period of use.

[0006] The present invention has been made in view of the above-described problems, and can be used over a long period of time. A composition for forming a wood-based coating layer that can provide a coating layer that is difficult to peel off, and a wood-based molded product that is difficult to peel off even if it is used for a long period of time. It is intended to be provided.

Means for solving the problem

In order to achieve the above object, the present invention is configured as follows. That is, the composition for forming a woody coating layer according to the present invention is characterized in that wood flour is blended with a base resin formed using a copolymer of _a -olefin and an unsaturated carboxylic acid. To do.

[0008] According to the composition for forming a woody coating layer according to the present invention, the use of a copolymer of base coconut resin ex-olefin and unsaturated carboxylic acid makes it possible to cover the object to be coated. It is possible to obtain a high adhesiveness to wood, and by adding wood flour, the surface of the formed coating layer has a wood texture and is incompatible with wood flour and base oil. As a result, when the covering layer is formed, the coating layer is likely to cause cohesive failure. Therefore, even when used for a long period of time, the covering layer can be obtained without being peeled off.

[0009] In addition, in the composition for forming a woody coating layer according to claim 1, the base resin is in a powder form, and if wood powder is blended in the powder form, It is preferable that the wood resin can be blended into the base resin with less processing, and the fluidity is provided, so that it can be easily applied to the outer surface of an object to be coated in various shapes.

[0010] Further, the wood-based molded product according to the present invention is a molded product in which a coating layer is provided on a base material, and a wooden texture is provided on the surface by the coating layer. Any one of 1 to 3 is characterized in that it is formed using the woody coating layer forming composition described in item 1.

[0011] According to the wood-based molded article according to the present invention, high adhesiveness to the object to be coated can be obtained by the base resin, and wood powder is blended, so that the surface of the coating layer is made of wood. The texture is provided, and the cohesive failure of the coating layer is likely to occur due to the incompatibility between the wood flour and the base resin, which makes it difficult for the coating layer to be peeled off even during long-term use. Can be a thing.

[0012] Further, in the wood-based molded article according to claim 4, the covering layer includes the wood-based covering. As long as it is formed by thermoforming the layer forming composition, a coating layer can be easily provided on a substrate having various shapes, and the adhesiveness of the base resin is exhibited. This is also preferable because it is easy.

[0013] In addition, in the woody molded article according to claim 4 or 5, if the surface of the coating layer is sanded, the visual texture is enhanced, and the exposed area of the wood powder is increased, resulting in a tactile sensation. The texture of the material is also enhanced, which leads to further improvement of the wood texture.

[0014] According to the composition for forming a woody coating layer according to the present invention, the use of a copolymer of base coconut resin ex-olefin and unsaturated carboxylic acid makes it possible to cover the object to be coated. It is possible to obtain a high adhesiveness to wood, and by adding wood flour, the surface of the formed coating layer has a wood texture and is incompatible with wood flour and base oil. As a result, when the covering layer is formed, the coating layer is likely to cause cohesive failure. Therefore, even when used for a long period of time, the covering layer can be obtained without being peeled off.

[0015] Further, according to the wood-based molded article according to the present invention, high adhesiveness to the object to be coated can be obtained by the base resin, and since the wood powder is blended, the surface of the coating layer is obtained. Has a wood texture and is incompatible with wood flour and base resin, making it easy to cause cohesive failure in the coating layer. It can be difficult to peel off.

Brief Description of Drawings

FIG. 1 is an explanatory view showing an embodiment of a wood-based molded body according to the present invention.

FIG. 2 is an explanatory view showing an example of an application method by thermoforming of a woody coating layer forming composition according to the present invention.

FIG. 3 is an explanatory view showing another embodiment of the wood-based molded body according to the present invention.

4 is a longitudinal sectional view showing details of a corner portion of the wood-based molded product shown in FIG.

FIG. 5 is a perspective view showing still another embodiment of the wooden molded body according to the present invention.

FIG. 6 is a perspective view showing an example of a product using a wood-based molded body according to the present invention. Explanation of symbols [0017] 1 Coating layer

11 Base oil

12 Wood flour

2 Base material

10 Wood-based molded products

A Woody coating layer forming composition

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] The best mode for carrying out the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a first embodiment of a wood-based molded product according to the present invention, where (a) is a perspective view showing the whole, and (b) is a sectional view showing details of a coating layer. It is. First, in (a), the deck material 10 is formed by providing the coating layer 1 over the entire circumference of the substrate 2, and the cross-sectional direction β is 138 mm and the thickness direction γ is 45 mm. The substrate 2 is made of an integral aluminum extruded profile, and the cross section of the base member 2 is provided in the length direction γ across the hollow portion 21 and one rib 22 is provided in the middle of the short direction β. The rectangular rib-shaped base material 2 in which the hollow portion 21 is divided into two is formed by providing a single rib 22 in the longitudinal direction a with a rectangular cross section. . By providing the rib 22 in the hollow portion 21 of the base material 2, the sectional moment of inertia is increased, and by using an aluminum extruded profile, the base material 2 having the same cross section in the longitudinal direction a can be easily obtained. Can do. A convex portion 23 is provided on the lower inner surface of the base material 2 so that the screws can be firmly fixed when the deck material 10 is attached to the joist.

[0020] The coating layer 1 is formed directly on the outer surface of the base material 2 which also serves as a strong aluminum extruded profile by extrusion coating. In (b), 80-mesh wood powder 12 obtained by pulverizing Batesga is dispersed almost uniformly in the base resin 11 which is an ethylene acrylic acid copolymer, and the surface of the coating layer 1 is the surface of Sandinda As a result, the surface becomes rough. Since the base resin 11 is an ethylene acrylic acid copolymer, high adhesion to the base material 2 made of aluminum is obtained. Also, the base resin 11 and the wood powder 12 are bonded, but are compatible! /, !!, so when an external force is applied to the coating layer 1, the stress is applied to the coating layer 1 and the substrate. World with 2 Since it does not concentrate on the surface and is also dispersed at the interface between the base resin 1 1 and the wood flour 12, even if the coating layer 1 is scratched to reach the base material 2, it can be peeled off quickly from the scratch. In addition, even when external force such as flying sand or expansion / contraction due to temperature change is strong, it does not peel off at the interface between coating layer 1 and substrate 2, and Although it is possible to break at the interface with the wood powder 12, the covering state by the covering layer 1 can be maintained for a long period of time when the peeling or breaking of the covering layer 1 does not proceed rapidly.

[0021] The copolymer of exo-refin and unsaturated carboxylic acid used for base resin 11 has a skeleton as a resin by ex-one-year-old refin and has durability, stability, etc. Adhesiveness to the base material is provided by the carboxylic acid. The a-olefin is preferably derived from polyolefin having from about 2 to about 8 carbon atoms, such as ethylene, propylene, isobutylene and hexene. The α-olefin component is more preferably ethylene or propylene. The most desirable α-olefin component is ethylene.

[0022] Unsaturated carboxylic acids include both monocarboxylic acids and polycarboxylic acids, and derivatives thereof including esters and acid anhydrides, such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, crotonic acid. , Acids such as maleic acid and fumaric acid that can react with amine functions to form amide bonds. Acid chlorides, amides and esters can also be used, including acrylic acid chloride and acrylamide. Examples of the esters include methyl acrylate, methyl methacrylate, ethyl acrylate and dimethylaminoethyl methacrylate. Monoesters of dicarboxylic acids such as monomethyl ester of maleic acid, monomethyl ester of fumaric acid, monoethyl ester of fumaric acid, and maleic anhydride can also be suitably used. The proportion of the unsaturated carboxylic acid component may be appropriately set according to the balance between the required adhesive strength and durability, but in general, about 1% force is about 35% based on the total number of moles. The carboxylic acid component is preferably a 20% carboxylic acid component of about 2% strength.

[0023] When ethylene is used as the ex-olefin component, acrylic acid is preferably used as the unsaturated carboxylic acid. That is, it is preferable that the base resin is an ethylene acrylic acid copolymer. This ethylene monoacrylic acid copolymer resin has excellent adhesion to aluminum and other base materials. By using ethylene monoacrylic acid copolymer resin as a base resin, it is highly filled with wood flour. Even in such a case, it is possible to obtain a composition for forming a woody coating layer having excellent adhesion to aluminum or the like. In addition, since ethylene acrylate copolymer resin has flexibility and excellent adhesion to wood flour, it can be used to coat wood-based molded products using a wood-based coating layer forming composition as a coating layer. It has the effect of suppressing the occurrence of cracks in the coating layer due to shrinkage in the layer thickness direction, and also has the effect of suppressing the occurrence of scratches on the surface.

[0024] Further, since the ethylene acrylic acid copolymer resin has excellent adhesion to wood flour, the wood-based coating layer forming composition and this wood-based coating layer forming composition were used for the coating layer. It is possible to prevent the bare wood powder from appearing on the surface of the wood-based molded product. That is, by using an ethylene-acrylic acid copolymer rosin, the surface of the wood powder can be easily coated with the rosin, and the wood-based coating layer forming composition itself that can be prevented from deteriorating the wood powder can be obtained. It is possible to make a wood-based molded article excellent in weather resistance, water resistance and chemical resistance.

In addition, the ethylene acrylic acid copolymer resin has a moist touch due to the action of moisture bonded to the carboxyl group oriented on the surface because the carboxyl group is introduced, Combined with the wood texture of wood powder, you can get a feeling that touches the living wood skin.

In view of such excellent adhesion to aluminum and wood flour, the acrylic acid content in the ethylene acrylic acid copolymer resin is preferably 5 to 10% by weight. More preferably, it is 6 to 9%.

[0025] The content of acrylic acid in this ethylene-acrylic acid copolymer resin can be determined by the IR method. For example, measurement with FT-IR is performed together with a sample having a known acrylic acid content. In addition, the absorbance attributed to the main chain and the absorbance attributed to the acrylic group were measured, and a calibration curve showing the correlation between the acrylic acid content and the absorbance can be prepared and determined. In addition, this ethylene-acrylic acid copolymer resin has a durometer hardness (in terms of being able to prevent damage while giving an appropriate texture to the surface when used for forming a coating layer of a wood-based molded article. Shore D) A force of 5 to 55 is preferred, especially 49 to 51 Good. It is also preferable that the tensile strength is 20 MPa or more and the tensile elongation at break is 500% or more. This durometer hardness can be measured based on JIS K 7115, and the tensile strength and tensile elongation at break can be measured based on JIS K 7113.

[0026] Further, when mixed with wood flour to make a composition for forming a woody coating layer, the processing temperature in extrusion molding is prevented from becoming high, and the risk of alteration of wood flour is reduced. On the other hand, it is preferable that the melt flow rate is 3 to 25 gZlOmin at a melting point of 100 ° C or less in that it can be extruded onto a substrate with moderate flowability. It is more preferable that it is ˜7 gZlOmin. Particularly preferred is 4-6 gZlOmin.

This melting point can be generally measured using a differential scanning calorimetric analyzer. For example, when a sample of about 5 mg is measured in a nitrogen atmosphere at a heating rate of 10 ° C Zmin. It can be obtained by measuring the peak value of the endothermic peak accompanying the phase transition of.

Further, it can be measured based on the melt flow rate ίO IS K 7210.

[0027] Wood powder 12 is often made from milled off-cut materials, waste materials, sawdust, etc., such as cedar, cypress, and baitsuga, and more preferably has a particle size of 10 to 500 mesh. What is 60 ~: About LOO mesh.

[0028] In the composition for forming a woody coating layer in which the base rosin and the wood powder are combined, the amount of the wood powder may be blended in an appropriate amount depending on the balance between the adhesion to the object to be coated and the wood texture. However, it is preferably 10 to 80% by weight, and more preferably 20 to 50% by weight.

As mentioned above, when the base resin is made of ethylene acrylic acid copolymer resin, the amount of wood flour that can be received is large. Wood powder can be blended, and for example, 100 parts by weight or more of wood powder can be blended with 100 parts by weight of ethylene acrylic acid copolymer resin.

In this way, a composition for forming a woody coating layer containing a larger amount of wood flour than the content of the wood flour of the coating layer formed on the substrate is actually prepared, and the desired composition is formed by so-called dry blending. A coating layer with a wood flour content can be formed.

For example, when extruding and laminating a coating layer on a substrate, ethylene-acrylic acid copolymer It is possible to mix pellets of body fat and pellets filled with wood powder with a ribbon blender and put them into a hopper, melt and mix them in an extruder, and laminate them on a substrate. . This means that it is no longer necessary to stock the composition for forming the wood-based coating layer for each wood-based molded product to be manufactured, and it is possible to handle high-mix low-volume products while reducing the inventory of materials. A wood-based molded product can be produced at a lower cost.

[0029] In blending wood flour with base rosin, wood flour is blended in a state where the base rosin is heated and melted, and then kneaded with a mixer, a twin screw extruder or the like, and granulated raw materials or pellets are mixed. As a powdered product obtained by further pulverizing them, or by mixing wood flour into a powdered base resin in advance, a single component can be used for grinding and grinding the base resin. This is preferable because it makes it easy to make the particle size uniform and can be easily formed without the need to knead the base resin and wood flour. In this case, it is preferable to approximate the particle size of the base resin, which is a powder, to the particle size of the wood powder, in order to improve the uniform dispersibility of the wood powder in the base resin, the average of the preferred wood powder It is preferable that the particle diameter of the base resin is distributed in the range of about 50 to 200% with respect to the particle diameter.

[0030] In addition, the composition for forming a wood-based coating layer is blended with a plasticizer, a stabilizer, a filler, a foaming agent, a foaming aid, an ultraviolet absorber, a pigment, an antistatic agent, and the like as necessary. Also good.

FIG. 2 is an explanatory diagram showing an example of a method for applying the woody coating layer forming composition according to the present invention by thermoforming. First, (a) is based on extrusion coating. Metal base material 2 is pulled by take-up machine T1 and preheated in preheating furnace Y, and then coating layer 1 is coated and molded into the body by extruder E. Is done. Here, to the extruder E, the powdery wood-based coating layer forming composition A charged in the hopper H is supplied, and in the extruder E, this wood-based coating layer forming composition A is supplied. The coating layer 1 is laminated on the substrate 2 by being melted. The wood-based molded article 10 continuously formed in the longitudinal direction by the extruder E is pulled by the take-out machine T2, and the outer shape is trimmed by the sizing S, cooled and solidified by the cooling tank C, and a predetermined length by the cutter K. Is cut into products.

[0032] At this time, since the coating layer 1 is formed of a wood-based coating layer forming composition in which wood powder that is not compatible with the resin material is contained in the ethylene acrylic acid copolymer resin, cutting is performed. Cohesive failure is likely to occur on the end face, and interfacial delamination with substrate 2 is suppressed. It is.

If interfacial delamination occurs at the cut end face or at the machining end such as an open end by a drill, delamination in the internal direction is likely to be derived from the delamination at the end, and between the substrate and the coating layer. Depending on the case where large peeling is likely to occur, there is a possibility that water will flow and corrode the base material. However, in the above-mentioned wood-based molded products, interfacial delamination is suppressed by causing cohesive failure at the processed end, so that the wood-based molded products maintain the excellent aesthetics at the beginning of production for a long period of time. At the same time, corrosion can be suppressed and long-term durability can be imparted to the wood-based molded product.

[0033] In extrusion coating molding, the shape and size of the wood-based coating layer forming composition A are not particularly limited, so long as it can be coated by the extruder E, it can be a powder, pellet, A shape such as a granulated piece can be used as appropriate.

[0034] Further, the coating layer has a shrinkage amount per lm of a wood-based molded product in 5 cycles of heat cycle tests at 20 ° C and 80 ° C within 0.5 mm, and from a smooth substrate made of metal to the interface. If it is made to be able to be peeled off, it is possible to prevent the coating layer from shrinking and the end force from being exposed to the substrate even under severe conditions of temperature change and use under conditions. In this case, the substrate and the coating layer can be separated to facilitate recycling, which is preferable. When a metal material is used for the base material and the composition for forming a wood-based coating layer in which an ethylene-acrylic acid copolymer resin is used as a base layer as a coating layer is extruded and laminated to the base material in this way. The surface temperature of the metal material used as the base material is used as the base of the composition for forming the wood-based coating layer in that the material and the coating layer can be separated and recycled easily. It is preferable to extrude and laminate by preheating to a temperature of 30 to + 10 ° C. with respect to the melting point of the combined resin, and the extrusion ratio is preferably about 1.0.

[0035] (b) is based on fluid immersion, and the base material 2 which is a mesh panel formed by welding metal wires vertically and horizontally is suspended on the hanger G, and the base material 2 is in a preheated state. Speak. The fluidized tank R is filled with the powdery composition A for forming a wood-based coating layer, and the wood-based coating layer forming composition A is blown with hot air from the lower side, so that the wood-based coating composition is formed. The composition A for coating layer formation is maintained at a certain high temperature and the powdery body is in a state close to floating. Yes. By immersing the base material 2 in this wood-based coating layer forming composition A, the wood-based coating layer forming composition A adheres substantially uniformly to the surface of the base material 2, and in this state, the base By heating and baking at a temperature at which the resin can be melted and the wood powder does not burn, the base resin is melted and leveled, and a smooth and uniform coating layer on the substrate 2 Can be obtained. For example, when an ethylene acrylic acid copolymer is used as the base resin and Batesga wood flour is blended, a suitable baking temperature is about 200 to 280 ° C.

[0036] When the coating layer is formed on the surface of the base material 2 by fluid immersion, it is suitable not only for mesh panels but also for base materials with particularly complex external shapes such as pseudo jewels, door knobs, various mounting brackets, etc. Can be applied. In addition, in the fluid soaking, it is preferable to approximate the particle sizes of the base resin and wood powder as described above. Both the base resin and wood powder preferably have a particle size of 10 to: LOOO / zm, preferably The thing of a particle size about 50-500 micrometers can be used suitably.

FIG. 3 is an explanatory view showing another embodiment of the wood-based molded body according to the present invention. The wood-based molded body 10A is formed by providing the coating layer 1 over the entire circumference of the base material 2, and the coating layer 1 is made of an ethylene acrylic acid copolymer as in the embodiment shown in FIG. The base 2 is formed by blending 80 mesh wood flour obtained by pulverizing Batesga into this base resin, and the base material 2 has an aluminum extruded profile. The cross section of the wood-based molded body 10A is 100 mm in both the left and right direction j8 and the up and down direction γ, and a protrusion 23 is provided near the center of the inner surface of the hollow section 21 in all four sections to firmly fix the screw. In addition, screw holes 24 for facilitating the attachment of caps and the like are provided on the inner surfaces of the four corners of the cross section.

FIG. 4 is a longitudinal sectional view showing details of a corner portion of the wood-based molded body 10A. The covering layer 1 is directly formed on a smooth metal substrate 2 and has a thickness of 2 mm. An R groove 25 is formed on the outer surface of the substrate 2, and the coating layer 1 enters the R groove 25, whereby the shrinkage in the length direction α can be further suppressed.

FIG. 5 is a perspective view showing still another embodiment of the wood-based molded body according to the present invention. In the wood-based molded body 10B, the coating layer 1 is formed directly on the outer surface of the substrate 2 as in FIGS. The longitudinal direction of the cross section of the wood-based molded body 10B is 60 mm, and the short direction is 40 mm. FIG. 6 is a perspective view showing an example of a product using the wood-based molded products 10A and 10B. The wood-based molded product 10A is used as a strut with the ground surface force standing upright, and the multi-stage wood-based molded product 10B is passed between the wood-based molded products 10A, which are a plurality of standing struts. As a result, the protective fence G is formed.

Example

[0041] Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited to these.

(Example 1)

A composition pellet for forming a woody coating layer of Example 1 was prepared according to the formulation shown in Table 1.

[0042] [Table 1]

The ethylene acrylic acid copolymer resin has an acrylic content of 7% by weight and a melting point of 98. C, melt flow rate 5 g ZlOmin, durometer hardness (Shore D) 50 was used. The wood flour used was an 80 mesh pass with Batesuga powder frame and polished frame.

Further, calcium carbonate having an average particle size of about 2. O / z m was used.

[0043] The composition for forming a woody coating layer of Example 1 was extruded and laminated on an aluminum substrate at an oil temperature of about 170 ° C using an extruder and cut into lms to obtain a woody molded product. Manufactured.

This wood-based molded article had good appearance and excellent texture. Moreover, the adhesion between the substrate and the coating layer was also good. Sarakuko, No peeling or shrinkage of the coating layer that would cause a practical problem even after 30 cycles of heat cycle test at 20 ° C x 3h / 80 ° C x 3h o

Also, shrinkage at the edge (difference between the edge of the substrate and the edge of the coating layer) is less than lmm, and the surface temperature of the aluminum substrate is preheated to a temperature of -30 to + 10 ° C. The shrinkage was less than 0.5 mm, which was confirmed to be particularly excellent. [0044] (Example 2)

A composition pellet for forming a woody coating layer of Example 2 was prepared according to the formulation shown in Table 2.

[0045] [Table 2]

[0046] A dry blend of the composition for forming a woody coating layer of Example 2 and an ethylene acrylic acid copolymer pellet at a ratio of 1: 1 by weight was about 170 ° C using an extruder. Extruded and laminated on an aluminum substrate at the temperature of the resin was cut into lm, and wood-based molded products were produced.

The composition for forming a woody coating layer of Example 2 was in a good mixed state without separating the wood powder from the composition for forming a woody coating layer.

Further, the formed wood-based molded article had a good appearance and excellent texture as in the case of using the wood-based coating layer forming composition of Example 1. Moreover, the adhesion between the substrate and the coating layer was also good. Furthermore, even when a heat cycle test of 20 ° C × 3h / 80 ° C × h was performed for 30 cycles, no peeling or shrinkage of the coating layer, which would be a practical problem, was observed.

Also, shrinkage at the edge (difference between the edge of the substrate and the edge of the coating layer) is less than lmm, and the surface temperature of the aluminum substrate is preheated to a temperature of -30 to + 10 ° C. The shrinkage was less than 0.5 mm, which was confirmed to be particularly excellent.

[0047] (Comparative Example 1)

A composition pellet for forming a woody coating layer of Comparative Example 1 was prepared according to the formulation shown in Table 3.

[0048] [Table 3] Material 酉 self amount (parts by weight)

High density polyethylene 1 0 0

Wood flour 3 0

Calcium carbonate 1 6

Pigment 1.5 High density polyethylene having a density of 964 kgZm ³ , a melt flow rate of 5 gZlOmin, and a durometer hardness (Shore D) of 73 was used.

The wood flour used was an 80 mesh pass with Batesuga powder frame and polished frame.

[0049] Further, the formed wood-based molded article had a good appearance as in the case of using the composition for forming a wood-based coating layer of Example 1 or Example 2, but the texture was similar to that of Example. It was inferior to the case where the composition for forming a woody coating layer of 1 or Example 2 was used. In addition, interfacial delamination was observed between the substrate and the coating layer at the cut end.

Furthermore, when a heat cycle test at 20 ° C x 3h / 80 ° C x h was performed, the shrinkage exceeded 1 mm in several cycles, and 3-5 mm shrinkage was observed after 30 cycles.

[0050] From these facts, it is also possible to form a woody coating layer, characterized in that wood flour is blended with a base resin formed using a copolymer of α-olefin and an unsaturated carboxylic acid. By using the composition, even if it is used for a long time, it is difficult to peel off.

Claims

The scope of the claims

[1] A composition for forming a woody coating layer, characterized in that wood flour is blended with a base resin formed using a copolymer of a-olefin and an unsaturated carboxylic acid.

[2] The composition for forming a woody coating layer according to [1], wherein the base resin is in the form of a powder, and wood powder is blended in the powder.

[3] The woody coating layer forming composition according to claim 1 or 2, wherein the base resin is an ethylene acrylic acid copolymer.

[4] The molded article according to any one of claims 1 to 3, wherein the covering layer is provided on a base material, and the covering layer is provided with a wooden texture on the surface, and the covering layer is the woody material according to any one of claims 1 to 3. A wood-based molded article formed by using a composition for forming a coating layer.

[5] The wood-based molded article according to claim 4, wherein the coating layer is formed by thermoforming the composition for forming a wood-based coating layer.

6. The woody molded article according to claim 4 or 5, wherein the surface of the coating layer is siding.