JP2537957B2 - Plate composite - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a plate-shaped composite body in which a thermoplastic resin sheet containing mica powder is composited on the surface of a synthetic wood-based plate-shaped material. More specifically, the wood-based plate-shaped material can not be used, such as contact with high temperature, contact with liquid substances such as water oil, contact with corrosive gas, outdoor use exposed to wind and rain, wood Impairing the characteristics of a wood-based plate-like material that has been made available for these purposes by compounding a thermoplastic resin sheet containing a mica powder having a specific shape on one or both sides of the plate-like plate-like material The present invention relates to a plate-shaped composite body having a light, inexpensive, and beautiful surface.

[Conventional technology]

Conventionally, for surface improvement of wood-based plate-like materials such as plywood, the method by surface coating is inexpensive and general, but it has poor durability and it is used for applications where it is exposed to high temperatures, liquids, corrosive gases, wind and rain, etc. There was a problem that this phenomenon appeared.

In order to solve these problems in recent years, a plate-shaped composite of a wood-based plate-like material such as plywood and a plastic sheet, a FRP plate and a metal plate such as Al is a building material, furniture, a bath unit,
It is used in fields such as frozen truck bodies and marine containers.

[Problems to be Solved by the Invention]

The composite of the wood-based plate-like material and the plastic sheet is lightweight and has an inexpensive and beautiful surface, but the rigidity of the plastic sheet is not sufficient so that the above-mentioned dance phenomenon cannot be fundamentally solved. is there.

Although the composite of wood-based plate material and FRP plate does not have a dance phenomenon due to contact with high temperature, liquid matter, corrosive gas, wind and rain, etc.
Since it is impossible to manufacture a thin FRP plate, it is heavy and cost /
It is inferior in terms of performance, and it is difficult to process such as cutting and boring, and reinforcing glass fibers are raised on the surface, and there are problems in surface smoothness and weather resistance.

In addition, the composite of wooden plate-like material and metal plate such as Al plate does not have the same dance phenomenon as the composite material with FRP plate, but it is difficult to process such as cutting and punching, and there is a risk of rust and corrosion, causing dew condensation. The current situation is that there are many problems.

Thus, the present invention provides an inexpensive wood-based plate-like composite which has good durability, does not cause the above-mentioned dance phenomenon, has excellent surface smoothness, has good processability, and is free from rust and corrosion. To do.

[Means for solving the problem]

The present inventors have conducted extensive studies to solve the above problems, and obtained by compounding a thermoplastic resin sheet containing a mica powder of a specific shape on one or both sides of a wood-based plate material such as plywood. The present inventors have found that the wood-based plate-like composite having the desired performance has desirable performance, and have completed the present invention.

That is, it is inexpensive to combine a thermoplastic resin sheet containing 10 to 60 weight percent of mica powder having a weight average flake diameter of 10 μm or more and 500 μm or less and a weight average aspect ratio of 10 or more on one or both sides of a wood-based plate material In addition, there is no fear of dance phenomenon, rust and corrosion in applications where it will come into contact with high temperature, liquid matter, corrosive gas, wind and rain, etc., easy processing such as cutting and drilling, no condensation phenomenon, surface smoothness It is an excellent and excellent wood-based plate-like composite.

The mica powder used in the present invention can be appropriately selected from phlogopite (phlogopite), muscovite (mascobite), synthetic mica, etc., and these have a weight average flake diameter of 10 μm or more and 500 μm or less and a weight average aspect ratio. It is necessary that the ratio is 10 or more, and preferable ranges include a weight average flake diameter of 20 μm or more and 200 μm or less and a weight average aspect ratio of 15 or more and 80 or less.

The weight average flake diameter and the weight average aspect ratio of the mica powder used in the present invention affect the mechanical performance such as rigidity, shape performance such as warpage and deformation, and heat resistance of the plate-like composite of the present invention.

The weight average flake diameter 1 of the mica powder in the present invention means the mica powder obtained by classifying the mica powder using various standard sieves or micro sieves, plotting the results on a Rosin-Rammlar diagram, and using the mica powder for measurement. Is a value defined by the formula (1) or (2) by using an opening l ₅₀ of a sieve or a microsieve through which 50% by weight of the total weight of is passed.

On the other hand, the weight average aspect ratio α of the mica powder in the present invention is a value calculated from the weight average flake diameter 1 and the weight average thickness d of the mica powder measured by the following method using the following formula. .

α = l / d (3) The weight average thickness d of the mica powder in the formula (3) is CECa.
Water surface mono-particle membrane method (CECapes and R.
C. Coleman, Ind. Eng. Chem. Fundam., 12, 124 (1973)) is a value calculated by the formula (4) using the occupied area S of the flakes on the water surface.

Here, W is the weight of the mica powder used for the measurement, ρ is the specific gravity of the mica, and (1-ε) is the occupancy rate when the mica powder is in the closest packed state on the water surface. 0.9 is used for calculation.

When the weight average flake diameter is less than 10 μm, the rigidity of the formed sheet is not sufficient, and there is no effect of suppressing the dance phenomenon in the above-mentioned wood-based plate-like composite. On the other hand, the weight average flake diameter is
If the thickness exceeds 500 μm, the rigidity of the formed sheet is sufficient, but the surface roughness of the obtained sheet causes the difficulty of production such as the production of a thin sheet. Surface smoothness deteriorates. On the other hand, if the weight average aspect ratio is less than 10, the rigidity of the formed sheet is not sufficient, the effect of suppressing the dance phenomenon in the wood-based plate-like composite is not exerted, and the heat resistance is poor.

It is necessary that these mica powders are blended in an amount of 10% by weight or more and 60% by weight or less in all components. If the content of the mica powder is less than 10% by weight, the rigidity of the molded sheet is not sufficient, the effect of suppressing the dance phenomenon in the woody plate-like composite is not exerted, and the heat resistance is poor. If the amount of mica powder exceeds 60% by weight, it is difficult to melt and knead and it cannot be formed into a sheet. Desirably a range of 15 to 50 weight percent is preferred.

In the present invention, it is necessary to use a mixture of the mica powder and the thermoplastic resin in a sheet form.

As the thermoplastic resin used in the present invention, for example, polyolefin resin, styrene resin such as acrylonitrile butadiene styrene resin, polymethylmethacrylate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyvinyl chloride resin, polyamide resin and the like are mainly used. As a component, a copolymer can be used, but from the viewpoint of cost / performance, polypropylene (hereinafter abbreviated as PP), polyethylene terephthalate (hereinafter abbreviated as PET), and a copolymer containing these as main components are particularly preferably used. .

Further, there is no problem in adding a plasticizer, a crystallization accelerator, a heat deterioration inhibitor, a heat stabilizer, an ultraviolet absorber, a lubricant, a flame retardant, a coloring agent, etc. to these thermoplastic resins, if necessary. It is also possible to use a filler other than the mica powder in combination.

A mixture of mica powder and a thermoplastic resin is used in the form of a sheet, but there is no limitation on the method of forming a sheet,
For example, mica powder and thermoplastic resin may be directly melted, kneaded, and formed into a sheet using a sheet manufacturing apparatus, or a sheet manufacturing apparatus in which the mica powder and the thermoplastic resin are made into pellets using an extruder or the like. May be used to form a sheet, as long as the mica powder having a specific shape is uniformly dispersed in the thermoplastic resin.

The sheet is used in a state in which it is compounded on one side or both sides of a wood-based plate-like material, but the sheet thickness is 0.2 mm to 1
mm, more preferably 0.3 mm to 0.8 mm. If the sheet is less than 0.2 mm, the rigidity is not sufficient, and the dance phenomenon of the plate-shaped composite cannot be suppressed. A sheet having a thickness of more than 1 mm gives sufficient performance as a plate-shaped composite, but becomes heavy in weight, which is not preferable from the viewpoint of cost / performance.

On the other hand, the wood-based plate-shaped material as the base material is not particularly limited, and various plywoods, particle boards, hard fiber boards, wood boards and the like can be mentioned, but plywoods typified by lauan plywood and kapole plywood are Particularly preferably used.

The present invention is a plate-shaped composite formed by combining a thermoplastic resin sheet containing a wood-based plate-shaped material and mica, and the compounding method is not particularly limited. For example, a wood-based plate-shaped material and a mica are mixed. A thermoplastic resin sheet to be prepared separately is prepared, and a compounding method using an adhesive, a compounding method by thermocompression bonding, a thermoplastic resin containing mica is formed into a sheet in a molten state. There are methods such as casting on the surface of the wood-based plate-shaped material and pressing it with a roll to form a composite, but any method is possible as long as the wood-based plate-shaped material and the thermoplastic resin sheet containing mica are bonded and integrated. Good.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

Example 1 PET resin ([η] 0.78) was blended with 30% by weight of natural phlogopite (trade name, manufactured by Kuraray Co., Ltd.) having a weight average flake diameter of 30 μm and a weight average aspect ratio of 28. Then, the mixture was kneaded using a single-screw extruder to obtain a mica-blended PET compound. The mica-blended PET compound was sheeted using a sheet manufacturing apparatus and then crystallized to a thickness of 0.
A PET sheet containing 4 mm of mica was obtained.

Next, the above mica-containing PET sheet was adhered to both sides of a commercially available 5.5 mm thick lauan plywood by using a hot melt adhesive (PEA-170H manufactured by Toagosei), and 60 cm x 60 cm thick 6.3 mm thick mica-filled PET plywood. A complex was obtained.

The specific gravity, surface roughness, dance state, workability, and bending performance of this plywood composite were measured, and the results are shown in Table-1.

Here, the measuring methods of these measurement items were as follows.

Specific gravity: 60 × 60 cm It was determined from the weight, size and thickness of the test piece.

Surface roughness: The surface roughness was measured using a surface roughness meter model SE-4 manufactured by Kosaka Laboratory, and expressed as the maximum roughness between 8 mm lengths.

Dance state: A 60 × 60 cm test piece is heat-treated in an oven at 120 ° C. for 30 minutes, placed on a smooth surface plate, and the warped state of the test piece is observed.

Workability: Observe the state of the machined surface, especially the burr state of the machined surface, by cutting the test piece with a rotating cutter, cutting with a hand saw and drilling with a drill.

Bending performance: Bending strength and bending elastic modulus are measured according to JIS-A-1408.

As is clear from these results, a lightweight plywood composite having sufficient performance as a composite was obtained.

Example 2 A mica-filled PET plywood composite having the same composition and the same method as in Example 1 except that a natural phlogopite having a weight-average flake diameter of 300 μm and a weight-average aspect ratio of 70 was used and having a thickness of 60 × 60 cm and a thickness of 6.3 mm. Got The same performance as in Example 1 was evaluated for this plywood composite, and the results are shown in Table-1. The surface roughness was a little rough due to the large particle size of the mica, but the elastic modulus was high, and it was a lightweight plywood composite having sufficient performance as a composite.

Examples 3 and 4 Other than changing the blending amounts of natural phlogopite having the same weight average flake diameter and weight average aspect ratio as in Example 1 to 15% by weight (Example 3) and 45% by weight (Example 4). A mica-filled PET plywood composite having the same composition and the same method as in Example 1 and having a size of 60 × 60 cm and a thickness of 6.3 mm was obtained. The same performance as in Example 1 was evaluated for this plywood composite, and the results are shown in Table-1. Although the bending performance of the composite slightly changed depending on the amount of mica compounded, it was a lightweight plywood composite having sufficient performance as a composite.

Example 5 A commercially available PP resin (MI = 0.8 g / 10 min) was blended with 40% by weight of natural phlogopite having a weight average flake diameter of 65 μm and a weight average aspect ratio of 45, and the same method as in Example 1 was used. A mica-blended PP sheet having a thickness of about 0.5 mm was obtained.

Next, place the mica-blended PP sheet on both sides of a commercially available 5.5 mm thick lauan plywood, further place mirror finish release plates on both sides, introduce into a flat plate press machine, and at 190 ° C at low pressure. After hot-pressing for 3 minutes, it was taken out and the mirror-finished release plate was peeled off to obtain a mica-filled PP plywood composite having a size of 60 cm × 60 cm and a thickness of 6.5 mm. The same performance as in Example 1 was evaluated for this plywood composite, and the results shown in Table 1 were obtained. As can be seen from the bending performance, the adhesive property was good without using an adhesive, the surface roughness was particularly good, and it was a lightweight plywood composite having sufficient performance as a composite.

Comparative Examples 1 to 4 Using the same PET resin as in Example 1, natural phlogopite (Comparative Examples 1 and 2) in which the weight average flake diameter and the weight average aspect ratio were changed as shown in Table 1 and Example 1 were used. Using the same phlogopite, the composition was changed (Comparative Examples 3 and 4) to obtain a mica-filled PET plywood composite having a size of 60 × 60 cm and a thickness of 6.3 mm in the same manner as in Example 1. The same performance as in Example 1 was evaluated for this composite, and the results are shown in Table-1.

When the weight average flake diameter and the weight average aspect ratio of natural phlogopite are small, the composite exhibits a phenomenon of bending and the bending performance is inferior, and when the weight average flake diameter is too large, a thin satisfactory sheet cannot be obtained and the composite is not formed. It was profitable.

When the ratio of natural phlogopite contained in PET resin was low, the composite showed a phenomenon of dance and the bending performance was poor, and when the ratio was too high, it was difficult to compound and the sheet could not be obtained.

Comparative Example 5 A commercially available Al plate having a thickness of 0.3 mm was bonded to both sides of a lauan plywood having a thickness of 5.5 mm, which was commercially available, by using an epoxy adhesive to form 60 × 60 cm.
Thus, an Al plywood composite having a thickness of 6.1 mm was obtained. The same performance as in Example 1 was evaluated for this composite, and the results are shown in Table-1.

Compared with the composite obtained according to the present invention, the weight of the composite is large, and the cost / performance is inferior.
It was inferior in workability such as drilling.

Comparative Example 6 A commercially available general sheet molding compound having a basis weight of 1.8 kg / m ² was placed on both sides of a commercially available 5.5 mm thick lauan plywood, and mirror finish release plates were placed on both sides of the lauan plywood.
Introduced into a flat plate press, temperature 140 ℃, pressure 30kg / cm ² 4
After heat-pressing for 1 minute, it was taken out, and the mirror-finished release plate was peeled off to obtain an FRP plywood composite body having a size of 60 × 60 cm and a thickness of 7.1 mm. The same performance as in Example 1 was evaluated for this composite, and
The results are shown in 1.

Compared with the composite obtained according to the present invention, it is difficult to form a thin surface layer due to the strength unevenness, so the weight of the surface layer becomes large, and accordingly the composite becomes heavy, so that the cost / performance is low. It was disadvantageous and was inferior in surface roughness and workability.

[Advantages of the Invention] According to the present invention, a wood-based plate-like composite having excellent durability, surface smoothness, good workability and no dance phenomenon can be obtained.

Claims (1)

(57) [Claims] 1. A weight average flake diameter of 10 μm or more, 500 μ
10 mica powder with a weight average aspect ratio of 10 or more
A composite body composed of a thermoplastic resin sheet containing 60 to 60 weight percent and a wood-based plate material.