JP2538755B2 - Synthetic wood having wood grain pattern and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic wood having a streak pattern simulating natural wood grain (hereinafter referred to as a wood grain pattern) and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION In recent years, synthetic wood manufactured from plastic materials has been marketed. Conventionally, this synthetic wood is mainly manufactured by sticking one surface layer sheet having a wood grain pattern on the surface of the plastic body,
The plastic body did not have such a wood grain pattern.

Further, such a synthetic wood is manufactured by two steps (a first step is a step of printing a grain pattern on a surface sheet, and a second step is a step of attaching the surface sheet to a main body). Since the manufacturing process is complicated and the surface pattern sheet is formed by simply sticking the surface layer sheet to the main body, if the surface layer sheet is damaged, the main body without the grain pattern is exposed and There was a problem that the decorative beauty was lost.

Therefore, as a method for solving such a problem, a method called cellca has been developed. However, there is a problem in that the wood grain pattern formed on the surface of the synthetic wood produced by this method is not true, and there is a great difference in touch from the natural wood. In addition, since the surface layer sheet having a wood grain pattern attached to the synthetic wood body is thin, when the mechanical surface of the synthetic wood is subjected to mechanical processing such as thin cutting or nailing, the surface grain of the synthetic wood is grained. There is also a problem that the decorative beauty of synthetic wood is likely to be lost as a result of the destruction of wood.

The present invention is a conventional synthetic wood as described above,
And made in view of the drawbacks of the manufacturing method thereof, having a wood grain pattern, the wood grain pattern is less likely to be lost due to the destruction or processing of the surface, and further, the touch and texture are natural and true. An object is to provide a synthetic wood and a method for producing the same.

[0006]

SUMMARY OF THE INVENTION A method for producing synthetic wood according to the present invention comprises mixing a main resin component, an auxiliary resin component, a foaming agent, a stabilizer and a lubricant to prepare a powdery mixture having a particle diameter of about 2 to 4 μm. A first step of producing, a second step of granulating a part of the powdery mixture produced in the first step to form granules having a diameter of 3 mm to 5 mm, the powdery mixture and the granules And a weight ratio of 1:10 to 1: 4, preferably 1: 6 to
A third step of mixing at 1: 4 and extruding with a screw extruder.

The synthetic wood according to the present invention is manufactured by the above method and has a wood grain pattern. In the present invention, the above-mentioned raw materials and additives, or the mixing ratio thereof can be appropriately changed according to the desired wood grain pattern. For example, as the main resin component, PV
Vinyl resin such as C (degree of polymerization of 800 to 1000) and the like; acrylic resin and the like as auxiliary resin component; Ca-Zn metal soap and the like as stabilizer; lead stearate and the like as lubricant; foaming agent , Azobisformamide (AZC) and the like are preferably used.

The screw extruder used in the present invention has a length-to-diameter ratio (L / D) of 20: 1 to 2
A single screw type extruder having a screw extrusion cylinder having a compression ratio (C / R) of 6: 1 and 2.3 to 2.5 is preferably used.

In this extruder, a plurality of heaters (1st to 5th heaters) are arranged on the outer periphery including the cylinder along the direction in which the material inside the extruder is pushed and advances, that is, along the material advancing direction. Heaters are 110-130 ℃, 14
It is preferable that a portion corresponding to the heater position inside the cylinder is heated so that the temperature ranges from 0 to 160 ° C, 170 to 190 ° C, 150 to 170 ° C, and 155 to 175 ° C.

According to the synthetic wood and the method for producing the same according to the present invention, since the surface layer having a wood grain pattern is thick, the wood grain pattern is not easily lost by surface destruction or surface processing, and the texture and texture are natural and true. A rich synthetic wood can be provided.

Further, according to the present invention, it is possible to manufacture synthetic wood having various grain patterns by changing the mixing ratio of the powdery mixture and the granular material.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described more specifically with reference to the accompanying drawings. FIG. 1 is a flow chart of a preferred embodiment of the present invention, and as shown in the figure, the method for producing a synthetic wood having a grain pattern of the present invention includes: a powdery mixture production step 1 and a granular granulation step 2 And an extrusion molding step 3 of a mixed material including a powdery mixture and a granular material
And 3 steps including

In the first step, appropriately selected basic raw materials are mixed to produce a powdery mixture having the specific particle size. The main resin component and the auxiliary resin component used in this step can be selected and used according to preference. Further, the mixing ratio of the raw materials may be appropriately changed, and may further contain other additives such as pigments. In particular, by adding a pigment to the composition raw material, or changing its type and color,
It is possible to manufacture synthetic wood having different color wood grain patterns, and it is also possible to manufacture products imitating wood such as spear, zelkova, cedar, and mahogany.

In the second step, a granular material having the above-mentioned specific particle size is produced from a part of the powdery mixture. Next, in the third step, the powdery mixture and the granular material are mixed at the above-mentioned specific ratio, and the obtained mixed material is introduced into an extruder for extrusion molding. In such an extrusion molding process, the mixed material in the extruder is kneaded and extruded while continuing the low foaming and introduced into the mold, and as a result, a synthetic wood having a natural grain pattern on its surface is molded. It will be.

Next, a preferred embodiment of the synthetic wood production method of the present invention will be described. First, in the first step, for example, the following materials are mixed to produce a powdery mixture having an average particle diameter of 2 to 4 μm. (1) Main resin component: polyvinyl chloride PVC (polymerization degree is about 800 to 1000) 65.6 to 86.6 parts by weight (2) Auxiliary resin component: acrylic resin 10 parts by weight (3) Blowing agent (azobisform Amide AZC) 0.4 parts by weight (4) Stabilizer: Ca-Zn-based metal soap 3-4 PHR (5) Lubricant: Lead-based hard fatty acid (lead stearate) 0.2-0.3 PHR Pigment Some notes: PHR: parts per hundred rubber or reisin. Part of a powdery mixture obtained by mixing these raw materials,
In the second step, introduced into a granulator and granulated, average particle size 3m
Granules of m-5 mm are prepared.

Then, in the following extrusion step 3, the above-mentioned powdery mixture and the granules are mixed in a weight ratio of, for example, 1:10 to 1: 4, preferably 1: 6 to 1: 4, and obtained. The mixed material is introduced into a single-screw extruder, and the material heated and mixed in the extruder is extruded into a molding die for molding. In the extruder, the mixed material foams due to the action of the foaming agent. For this foaming, the material heating temperature and the like should be adjusted so that the specific gravity of the obtained molded product becomes 0.6 to 0.9. Controlled by. At this time, the grain pattern can be adjusted to a desired form by adjusting the mixing ratio of the powdery mixture and the granular material within the above range.

An extruding machine suitably used in the extruding step 3 can be exemplified by an extruding machine having a special design as described later. Here, this extruding machine is shown in FIGS. 2 and 3. Will be described with reference to. FIG. 2 is a configuration diagram showing a single-screw extruder preferably used in the present invention, and FIG. 3 is an enlarged configuration diagram showing a die mounting portion of the single screw extruder preferably used in the present invention. Is.

As shown in FIG. 2, this extrusion molding machine 4
Includes a cylinder 41 and an extrusion die 42 provided at the tip of the cylinder 41. Among them, a single screw 43 is provided in the cylinder 41, and the inside of the cylinder 41 is divided into three parts of a supply part 411, a compression part 412, and a measuring part 413 as the diameter of the single screw 43 changes.

A plurality of divided heating elements 44 are provided outside the cylinder 41 and the extrusion die 42. The heating positions of these heating elements 44 in the extrusion molding machine 4 are:
It is indicated by A, B, C, D and E in the figure. These 5
The extruder internal heating temperature by the heating element 44 at each of the two heating positions is in the order of the above temperature ranges, that is, A: 110-110.
130 ° C, B: 140 to 160 ° C, C: 170 to 190
° C, D: 150-170 ° C and E: 155-175 ° C
Is controlled. As can be seen from the correspondence between the installation position of the heating element 44 and the heating temperature, the extruder 4 not only heats the mixed material in the cylinder 41 but also continuously heats it in the extrusion die 42. continuing.
And, in particular, the heating temperature of the extrusion die 42 is set to the cylinder 41.
It is set lower than the heating temperature in. More specifically, in this extrusion molding machine 4, it is preferable that the maximum heating temperature of the mixed material is set to the extreme end of the cylinder 41, and the heating temperature is set to be slightly lower in the extrusion die 42 on the downstream side thereof. By thus setting the heating temperature in the molding machine 4 in multiple stages and kneading with the single screw 43, the powdery mixture and the granular material are continuously mixed while being sufficiently mixed in the extrusion molding machine. Can be foamed as a result, resulting in molded articles (synthetic wood)
A wood grain pattern will be formed.

Further, in such an extruder 4, the length / diameter ratio (L / D) of the single screw 43 is further increased.
By adjusting the compression ratio (C / R) and the density or average degree of the mixed material in the cylinder 41, the thickness of the surface layer having a grain pattern can be adjusted.
It is preferable to set / D to 20: 1 to 26: 1 and C / R to 2.3 to 2.5.

In the extrusion molding step 3 in which such an extruder is preferably used, as described above, the mixed material foams due to the action of the foaming agent. This foaming depends on the kind of the foaming agent used or the extrusion. By adjusting various conditions such as heating conditions and compression ratio of the molding machine, a low foaming state, that is,
The specific gravity of the obtained molded product is controlled to be 0.6 to 0.9.

FIG. 3 is an enlarged configuration diagram of a die mounting portion of a single screw extrusion molding machine preferably used in the present invention. As shown in the figure, the extrusion die 42 mounted on the tip of the cylinder 41 is A molding die 430 is provided which has a flow straightening plate 421 and is located at a predetermined distance from the exit of the extrusion die 42. The straightening plate 421 formed substantially in the center of the extrusion die 42 straightens the flow of the mixed material so that the mixed material 422 kneaded in the cylinder 41 is pushed out of the extrusion die 42 on average. Inside the cylinder 41 and the extrusion die 42, the mixed material 422 composed of the powdery mixture and the granular material, which are mixed in a proper proportion as described above, is continuously heated and kept at a low temperature even when extruded through the extrusion die 42. Maintain the foamed state. Extruded mixed material 42
2 is sent to the inside of the mold 430 through the flow straightening plate 423 of the mold 430 and is cooled and molded by the cooling water 424, has a wood grain pattern on the surface layer, and has an appropriate shape according to the mold cross-sectional shape. A molded article having

[0023]

As described above, according to the synthetic wood having a wood grain pattern and the method for producing the same according to the present invention, since the surface layer having the wood grain pattern is thick, the wood grain pattern is formed by surface destruction or surface processing. It is possible to provide a synthetic wood which is hard to be lost and has a natural touch and texture and is rich in truth.

Further, according to the present invention, the synthetic wood having various wood grain patterns can be manufactured by changing the mixing ratio of the powdery mixture and the granular material. Hereinafter, the present invention will be described in more detail with reference to Production Examples.
The present invention is not limited to the following examples.

[0025]

[Production Example 1] Polyvinyl chloride PVC as main resin component
( Polymerization degree : 900) 85 parts by weight, 5 parts by weight of acrylic resin as an auxiliary resin component, 0.4 parts by weight of azobisformamide as a foaming agent, 3.5 PHR of Ca-Zn metal soap as a stabilizer, Lead stearate 0.25 PHR as lubricant and titanium 0.01 as pigment
Parts by weight were mixed to produce a powdery mixture having an average particle size of 3 μm (first step).

Then, the obtained powdery mixture was introduced into a granulator to produce granules having an average particle diameter of 3 mm (second step). The powder mixture and the granules obtained in the first and second steps are mixed at a mixing ratio of 1: 8, and extrusion molding having a cylinder 41 shown in FIG. 2 and a mold mounting portion shown in FIG. It was introduced into the machine and a molded product was manufactured (third step). At this time, various conditions of the extruder were set as follows.

L / D: 24 C / R: 2.3 Heating temperature distribution: A; 120 ° C., B; 150 ° C., C; 1
80 ° C., D; 160 ° C., E; 165 ° C. Specific gravity of molded product: 0.75 Mold cross-sectional shape: rectangle 55 mm long × 30 mm wide, corner R
5 mm A photograph of the obtained synthetic wood is shown in FIGS. 4 and 5. FIG.
Is a photograph showing a perspective image of the synthetic wood obtained in Production Example 1, and FIG. 5 is a photograph showing a longitudinal section thereof.

[0028]

[Production Example 2] Synthetic wood was produced in the same manner as in Production Example 1 except that the red pigment Red 309 was used as the pigment to be used and the die cross section was a circle having a diameter of 60 mm.

A photograph of the obtained synthetic wood is shown in FIG. FIG. 6 is an end view of the synthetic wood obtained in Production Example 2.
The synthetic woods obtained in the above Production Examples 1 and 2 are shown in FIG.
As can be seen from FIG. 6, the wood grain pattern on the surface is extremely natural and has a real feeling, and the texture is almost the same as that of raw wood, and it was so hard to know that it was made of plastic. .

Further, as particularly shown in FIG. 6, the surface layer having the formed wood grain pattern is thick. Therefore, even if the surface of each of the synthetic woods of Examples 1 and 2 was cut to remove a considerable amount of the wood, a woody grain pattern was still seen in the cut portion, and the decorative beauty was not affected. . In addition, in Production Example 2, the pigment is a red pigment Red 3
Since the synthetic wood was manufactured by changing to 09, it was possible to manufacture a mahogany-like synthetic wood having a slightly reddish wood grain pattern.

[Brief description of drawings]

FIG. 1 is a flow chart of the preferred embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a single-screw extruder preferably used in the present invention.

FIG. 3 is an enlarged configuration diagram of a die mounting portion of a single screw extruder that is preferably used in the present invention.

FIG. 4 is a perspective view of a synthetic wood produced by the method of the present invention.

5 is a vertical cross-sectional view of the synthetic wood of FIG.

FIG. 6 is a cross-sectional view of synthetic wood produced by the method of the present invention.

[Explanation of symbols]

 4 ... Single screw extruder, 44 ... Heating element 42 ... Extrusion die 412 ... Single screw 230 ... Mold

Claims (6)

(57) [Claims] 1. A main resin component, an auxiliary resin component, a foaming agent, a stabilizer and a lubricant are mixed, and the powder particle size is approximately 2 to 4 μm.
A first step of producing the powdery mixture of No. 3, a second step of granulating a part of the powdery mixture produced in the first step to form a granular material having a diameter of 3 mm to 5 mm, and the powder Of the mixture of particles and the granules in a weight ratio of 1:10
A third step of extruding the mixed material containing 1: 4 with a screw extruder, and a method for producing a synthetic wood having a wood grain pattern, the method comprising: 2. The main resin component is PVC, the auxiliary resin component is acrylic resin, the stabilizer is Ca—Zn metal soap, the lubricant is lead stearate, and the foaming agent is azobisformamide (AZC). Item 2. The manufacturing method according to Item 1. 3. The front screw extruder has a ratio of length to diameter of 20: 1 to 26: 1 and an extrusion pressure ratio of 2.3.
The manufacturing method according to claim 1 or 2, which is a single-screw type extruder equipped with a screw extrusion cylinder having a size of 2.5. 4. The front screw extruder is provided with first to fifth heaters on the outer periphery thereof along the material pressing direction, and each heater has 110 to 130 inside the installation location.
℃, 140-160 ℃, 170-190 ℃, 150-1
The manufacturing method of Claim 3 which heats so that it may become a temperature range of 70 degreeC and 155-175 degreeC. 5. A synthetic wood having a wood grain pattern, which is produced by the production method according to any one of claims 1 to 4. 6. A molded product having a wood grain pattern, which is manufactured by the manufacturing method according to any one of claims 1 to 4.