JP2005271209A - Weatherable synthetic wood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide weatherable synthetic wood obtained by bonding a surface material excellent in weatherability to a main body material based on a polypropylene resin with excellent bondability. <P>SOLUTION: The weatherable synthetic wood is constituted by bonding the surface material based on a weatherable synthetic resin to the outer surface of the main body material based on a foamed polypropylene resin by coextrusion molding. The main body material is a foam of a composition prepared by mixing a resin or the like being the main component of the surface material with a polypropylene resin as a bonding improving agent and mixing 5-400 pts.wt. of sawdust with 100 pts.wt. of the polypropylene resin. The surface material is based on an acrylonitrile/acrylate rubber/styrene copolymer resin and/or an acrylonitrile/ethylene/propylene rubber/styrene copolymer resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a synthetic wood having a surface material, and more particularly to a synthetic wood that has excellent weather resistance and can be used for outdoor use and has a strong joint between the surface material and the main body material.

Conventionally, synthetic wood having a surface layer has no water absorption compared to natural wood, the material is uniform, and there is no decay by insects such as decay by decaying fungi, dirt by spiders, termites, It is excellent in dimensional stability, mechanical strength uniformity, surface condition uniformity, durability, etc., and is widely used in building interiors and interior materials including water.

Since this kind of synthetic wood is desired to be handled in the same way as natural wood, in order to provide the same density as natural wood and processability such as nailing and sawing, and to prevent scratches caused by external forces In addition, a skin layer that covers the outer surface of the main body made of foamed resin material is provided, or a surface material with excellent non-foaming or low-foaming bondability is joined to the main body material made of foamed resin material. Therefore, the physical properties of excellent workability and high surface strength are imparted.

By the way, in the plastics industry, recycling of materials is actively performed in response to a request to reduce waste. Polypropylene resin (hereinafter PP)
It is called resin. ) Generates a large amount of waste, and attempts have been made to use this waste PP resin as a raw material for synthetic wood.
However, since this synthetic wood is inferior in weather resistance to PP resin, it is difficult to use it outside the building and its use is limited.

Therefore, in order to enable outdoor use, an acrylonitrile-acrylate rubber-styrene copolymer resin (hereinafter referred to as AAS resin) or acrylonitrile that is excellent in weather resistance as a surface material on a main body made of a foam material of PP resin. -Joining of ethylene / propylene rubber-styrene copolymer resins (hereinafter referred to as AES resins) was studied, but these resins have poor bonding properties with PP resins and easily peel off at the bonding surfaces. Had the problem of
In addition, the PP resin as the main body material has a problem in using as it is because the basic physical properties as a synthetic wood are low in rigidity and large in shrinkage compared with other synthetic resins.

The present invention was created in order to solve the above-mentioned problems. In a synthetic wood having PP resin as a main component of a main body material, the present invention imparts necessary physical properties to the main body material and joins the main body material and the surface material. The problem to be solved is to provide synthetic wood with improved properties.

The weather-resistant synthetic wood of the present invention for solving the above problems is a synthetic wood in which a surface material mainly composed of a weather-resistant synthetic resin is bonded to the outer surface of a main body material composed mainly of a foamed PP resin by coextrusion molding. In the above-mentioned main body material, PP resin as a main component, acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as ABS resin), one or more of AAS resin and AES resin as a bonding improver, While mixing 5 to 50 parts by weight, preferably 10 to 25 parts by weight with respect to 100 parts by weight of the PP resin, the wood flour is 5 to 400 parts by weight, preferably 80 to 200 parts by weight with respect to 100 parts by weight of the PP resin. Partly mixed foam of the main body material composition, and the surface material is a molded body of the surface material composition mainly composed of AAS resin and / or AES resin, and the book Bonding strength between wood and the surface material is characterized in that the junction modifiers to the body member is high in comparison with the case of the unmixed.

In preferable embodiment of the synthetic wood of this invention, the said main body material is 1.2-3.0.
It is a solid foam that has a double expansion ratio and is formed into a long shape. The surface material composition is composed of a main component of the surface material and a polypropylene resin that is the main component of the main body material bonded to the surface material composition. Mixing as an improving agent, wood powder is desirably mixed in an amount of 5 to 30 parts by weight with respect to 100 parts by weight of the main component of the surface material, and a woody pigment is mixed.
It is configured as a molded article that is foamed to a foaming ratio of ˜1.2 times to give a wood texture to the surface as well as weather resistance.

In another preferred embodiment of the synthetic wood of the present invention, the main body material composition comprises a main component PP resin, ABS resin and / or AES resin as a bonding improver for the main body material, It is configured as a mixture of 10 to 25 parts by weight with respect to 100 parts by weight of the PP resin.
In another preferred embodiment of the synthetic wood of the present invention, the amount of the PP resin mixed as the bonding improver with the main component of the surface material is 3 with respect to 100 parts by weight of the main component of the surface material. -10 parts by weight, more preferably 5-7 parts by weight.

In another preferred embodiment of the synthetic wood of the present invention, the main body material is made of a glass fiber wire mainly composed of glass fiber at a position that is substantially symmetrical in the vertical and horizontal directions of the cross section of the main body material. It is buried along the vertical direction.
As said glass fiber wire, what impregnated polypropylene resin to the glass fiber bundle which bundled the glass fiber can be used.

According to the present invention, in synthetic wood having PP resin as a main component of the main body material, it improves the bondability of the surface material having excellent weather resistance to the outer surface of the main body material, and with the improvement of the bondability. It is possible to provide a weather-resistant synthetic wood in which the resulting main body has improved rigidity and shrinkage rate.

The weather-resistant synthetic wood according to the present invention includes a main body (core portion) formed of foamed PP resin, a surface material mainly composed of the weather-resistant synthetic resin, and joined to the outer surface of the main body by coextrusion molding. It is what has.
The main body material is composed mainly of PP resin, and 5 parts of ABS resin, AAS resin, and AES resin are added to 100 parts by weight of the PP resin as a bonding improver.
-50 parts by weight, mixed with wood powder in an amount of 5 to 400 parts by weight, preferably 80 to 200 parts by weight. Further, an appropriate amount of a foaming agent is added and these raw material compositions are mixed and foamed for foaming. It is a body.

When the main body material is mixed with ABS resin and one or more of AAS resin or AES resin, which is a component of the surface material, the bonding strength with the surface material is significantly higher than that of the material not mixed with the bonding material. Get higher. This is because ABS resin, AAS resin and A
This is considered to be due to the good compatibility between the acrylic functional groups in the ES resin. That is, it is considered that the functional groups exert a binding force at the interface between the main body material and the surface material to increase the bonding force.
When this bonding improver is less than 5 parts by weight with respect to 100 parts by weight of the PP resin, the bonding force is not much different from that when the bonding improver is not mixed. Absent.
Moreover, it is preferable that this joining improving agent is a mixture of ABS resin and AES resin, and the mixing ratio with respect to PP resin is 10 to 25 parts by weight with respect to 100 parts by weight of PP resin.

The wood powder in the material composition of the main body is mixed to increase the rigidity of the PP resin and reduce the linear expansion coefficient and reduce the weight, and the mixing ratio is less than 5 parts by weight. When the mixing effect is not sufficiently observed and the amount exceeds 400 parts by weight, the foaming property is remarkably deteriorated, and the required performance as a synthetic wood is not satisfied.

The foaming agent to be added to the main body composition is mixed in the composition within the range of 0.5 to 6.0 parts by weight in the form of a master batch with respect to 100 parts by weight of the PP resin, and directly in the extruder. Knead and melt to foam. The foamed composition is extruded as a solid foam body through a mold. The expansion ratio is generally 1.2 to 3.0 times, preferably about 2 times.
When the expansion ratio is less than 1.2 times, the density increases and the workability decreases, and when it exceeds 3.0 times, the strength decreases, which is not preferable.
The density when the mixing amount of the main body wood powder is 120 parts by weight is 1.2 times the foaming ratio.
The magnification is about 0.99, and the magnification of 3.0 is about 0.40, which is almost the same as natural wood.
In order to color the main body material, an appropriate amount of pigment can be added in the range of 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the PP resin.

The surface material is a composition in which any one of AAS resin and AES resin or a mixture thereof is a main component, and further, a PP resin which is a component of the main body material is desirably mixed as a bonding improver Is coextruded with the body material.
By mixing this bonding improver with the surface material, a synergistic effect is produced and the bonding force between the main body material and the surface material is further increased as compared with the case where the bonding improver is mixed only with the main body material.
The mixing ratio of the surface material bonding improver is 3 to 10 parts by weight with respect to 100 parts by weight of the main component,
The amount is preferably 5 to 7 parts by weight, and if it is less than 3 parts by weight, the effect is not recognized.

In addition, a small amount of foaming agent is mixed with the surface material to cause foaming to a foaming ratio of about 1.1 to 1.2 times, and wood powder and pigments are added to improve the appearance and texture of the wood. Can give a texture.
The addition amount of the wood flour is 5 to 60 parts by weight, preferably 5 to 100 parts by weight of the main component.
When the amount is less than 5 parts by weight, there are few changes in the appearance and feel, and when it exceeds 60 parts by weight, the mechanical strength is undesirably lowered.
The addition amount of the foaming agent is in the range of 0 to 3.0 parts by weight with respect to 100 parts by weight of the main component in the master batch, and the addition amount of the pigment is 0.5 to 10 parts with respect to 100 parts by weight of the main component. The range is 0 part by weight.

Here, in order to obtain a wood texture while ensuring the necessary mechanical strength, the foaming ratio of the surface material is about 1.1 to 1.2 times, and the mixing amount of the wood powder is 5 to 30 parts by weight. It is preferable that the pigment has a woody color. If the mixing amount of the wood powder is increased, the appearance becomes closer to that of natural wood, but the weather resistance is lowered and the surface hardness is lowered, which is not preferable as a construction material. Therefore, the foaming ratio, the amount of wood powder mixed, and the combination of wood color pigments are most balanced in terms of mechanical strength and wood texture as synthetic wood.

The thickness of the surface material is about 0.05 to 0.7 mm, preferably 0.5 mm.
It is.
If this thickness is less than 0.05 mm, the weather resistance is not sufficient and the surface hardness is insufficient, and if it exceeds 0.7 mm, the weather resistance is constant and there is almost no further increase. Absent.
Moreover, the surface material containing a joining improving agent can be made into the foam of the range of 1-2 times, and the density in this case will be 1.16-0.58.

The synthetic wood has a metal reinforcing material (wire material or plate material) such as aluminum or iron, or a glass fiber wire in the vicinity of both ends in the cross section of the main body formed into a long shape, or in the center in the width direction of the cross section, It may be embedded along the longitudinal direction of the main body material. The embedding of these reinforcing materials can be performed simultaneously with the extrusion of the main body material. Synthetic wood in which this reinforcing material is embedded over its entire length is preferable because the mechanical strength increases and the linear expansion coefficient decreases, so that the usage is widened.

A structural example of synthetic wood in which a glass fiber wire is embedded as the reinforcing material will be described more specifically based on the drawings.
FIG. 1 shows a cross section of a synthetic wood 1A in which the glass fiber wire 10 is embedded.
As shown in FIG. 1, the synthetic wood 1 </ b> A has a surface material 3 joined to the outer periphery of a main body 2 made of a solid foam, and the vertical axis and the center line in the width direction of the main body 2. Thus, a large number of glass fiber wires 10 are embedded along the length direction of the main body 2 at positions that are vertically and horizontally symmetrical.
In this way, a large number of glass fiber wires 10 are embedded in the symmetrical position of the synthetic wood 1A having a symmetrical shape with respect to the center line, which is preferable because the stress balance becomes uniform.

This glass fiber wire 10 is an integral product obtained by impregnating a bundle of a plurality of single glass fibers impregnated with PS resin, and when the main body 2 is extruded from the mold, the main body from the rear side of the mold. 2 is supplied in the extruding direction and embedded at the same time as molding of the synthetic wood 1A. When the glass fiber wire 10 is supplied to the mold, the impregnated PS resin softens immediately and the foam P of the main body material 2 is softened.
It melts and joins with S resin mutually. Thus, when the impregnated synthetic resin of the glass fiber wire 10 and the constituent synthetic resin of the main body material 2 are coincident with each other, they are melted and joined together in a softened state.

FIG. 2 shows a cross section of the deformed synthetic wood 1B in which the glass fiber wire 10 is embedded.
This deformed synthetic wood 1B is used as a deck material or the like, and is used by connecting a plurality of pieces in the left-right direction. For this reason, it has the 1st connection part 4 and the 2nd connection part 5 on each right and left, and the 2nd connection part 5 of the other modified synthetic wood 1B is engaged and connected with the 1st connection part 4. . And the required number according to the required width of a construction area repeats this engagement, and forms a deck.
In this deformed synthetic wood 1B, a large number of positions are substantially vertically and horizontally symmetrical with respect to the center line in the vertical direction and the width direction of the main body 2 of the main part excluding the first and second connecting parts 4 and 5. A glass fiber wire 10 is embedded along the length direction of the main body 2.
The manufacturing method of this deformed synthetic wood 1B and the method of embedding the glass fiber wire 10 are the same as those of the synthetic wood 1A.
The deformed synthetic wood 1B has the first and second connecting portions 4 and 5 and thus is not symmetrical with respect to the center line, but the cross-sectional area of the main portion that is symmetrical vertically and horizontally is About 7
As long as it is a synthetic wood that can be split over, the other parts have little effect on the expansion and contraction of the synthetic wood. If 10 is embedded, there is no practical problem.

The number of embedded glass fiber wires 10 varies depending on the shape of the synthetic wood, but is generally 4 to
0.
The impregnated synthetic resin of the glass fiber wire 10 is not limited to PP resin, but when a synthetic resin different from the constituent synthetic resin of the main body material 2 is used, the glass fiber wire 10 is coated with an adhesive. Embedded in the main body 2.

As a synthetic resin material of the above synthetic wood, particularly as a material of the main body, virgin material and / or
Alternatively, recycled materials can be used.
PP resin, which has a large production volume in the plastics industry, generates a large amount of waste.
Recycling to synthetic wood as a recycled material meets society's demand to reduce waste.
Although the synthetic wood is for outdoor use, it can of course be used for indoor use.

Next, examples and comparative examples of the present invention will be described.
[Example]
The material composition of the main body was as follows.
-PP resin 100 parts-Wood flour 150 parts-AAS resin (joining improver) 18 parts-Foaming agent 2.5 parts-Pigment (color: brown) 2.0 parts by weight

The material composition of the surface material was as follows.
AAS resin 100 parts by weight PP resin (bonding improver) 6 parts by weight Pigment (hue: woody color) 2.0 parts by weight The above main body material and surface material are supplied to an extruder and co-extruded, Foaming rate is almost 1.8
Synthetic wood having a thickness of about 0.5 mm was manufactured on the outer surface of the double body material.

[Comparative example]
A synthetic wood composed of a main body material and a surface material having the same composition other than the above was added in the same manner.
About said Example and a comparative example, the test which peels a main body material and a surface material by hand was done, and these joining force was compared.
[result]
The synthetic wood of the example was firmly bonded and was difficult to peel by hand.
On the other hand, the synthetic wood of the comparative example was weakly bonded and easily peeled off by hand.

The cross-sectional view of the synthetic wood which embed | buried the glass fiber wire. Cross section of other synthetic wood with embedded glass fiber wire.

Explanation of symbols

1A, 1B Synthetic wood 2 Body material 3 Surface material 10 Glass fiber wire

Claims (11)

In synthetic wood in which a surface material mainly composed of weathering synthetic resin is joined by coextrusion molding to the outer surface of the main body material mainly composed of expanded polypropylene resin,
The main body material is polypropylene resin as a main component, and acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-acrylate rubber-styrene copolymer resin, and acrylonitrile-ethylene / propylene rubber-styrene copolymer resin as a bonding improver. And a mixture of 5 to 400 parts by weight of wood powder with respect to 100 parts by weight of the polypropylene resin.
The surface material is a molded body of a surface material composition mainly composed of acrylonitrile-acrylate rubber-styrene copolymer resin and / or acrylonitrile-ethylene / propylene rubber-styrene copolymer resin,
The bonding force between the main body material and the surface material is higher than when the bonding improver is not mixed in the main body material,
Weather-resistant synthetic wood characterized by that. The main body material has a foaming ratio of 1.2 to 3.0 times, and is a solid foam molded into a long shape,
The surface material composition is a composition in which the main component of the surface material is mixed with a polypropylene resin as a main component of the main body material as a bonding improver, and wood powder is mixed.
It is a molded product with a wood texture on the surface as well as weather resistance.
The weather-resistant synthetic wood according to claim 1. The surface material is a composition in which the wood powder is mixed in an amount of 5 to 30 parts by weight with respect to 100 parts by weight of the main component of the surface material, and a wood color pigment is mixed. The weather-resistant synthetic wood according to claim 2, which is a foam-molded product foamed at a double foaming ratio. The weather-resistant synthetic wood according to any one of claims 1 to 3, wherein the main body material composition is a mixture of 80 to 200 parts by weight of wood flour with respect to 100 parts by weight of the polypropylene resin in the composition. The weather resistant synthetic wood according to any one of claims 1 to 4, wherein the main body material composition is a mixture of 5 to 50 parts by weight of the bonding improver with respect to 100 parts by weight of the polypropylene resin in the composition. . The weather resistant synthetic wood according to any one of claims 1 to 4, wherein the main body material composition is a mixture of 10 to 25 parts by weight of the bonding improver with respect to 100 parts by weight of the polypropylene resin in the composition. . The main body material composition includes a main component polypropylene resin, an acrylonitrile-butadiene-styrene copolymer resin and / or an acrylonitrile-ethylene-propylene rubber-styrene copolymer resin as a bonding improver for the main body material. Is mixed with 10 to 25 parts by weight per 100 parts by weight of the polypropylene resin.
The weather resistant synthetic wood according to any one of -4. The weather resistance according to any one of claims 1 to 6, wherein a mixing amount of the polypropylene resin mixed as the bonding improver with the surface material is 3 to 10 parts by weight with respect to 100 parts by weight of the main component of the surface material. Sex synthetic wood. The weather resistance according to any one of claims 1 to 6, wherein the amount of the polypropylene resin mixed with the surface material as the bonding improver is 5 to 7 parts by weight with respect to 100 parts by weight of the main component of the surface material. Sex synthetic wood. The said main body material is embedded in the length direction of the above-mentioned main body material in the length direction of the above-mentioned main body material, in which the glass fiber wire material which has glass fiber as a main ingredient is embedded in the position which becomes symmetrical in the up-and-down of the cross section, and the horizontal direction. Weather-resistant synthetic wood according to any one of 1 to 9. The weather-resistant synthetic wood according to claim 10, wherein the glass fiber wire is formed by impregnating a glass fiber bundle obtained by bundling glass fibers with a polypropylene resin.

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