JP2000343529A - Manufacture of woody resin composition, woody resin composition obtained thereby and its molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly mix a cellulosic material and a thermoplastic plastic material in a short time by a method wherein the cellulosic material granulated in a pellet state while a thermoplastic plastic material is melted is ground in a fine powder state, and mixed in the thermoplastic plastic material of a molten state. SOLUTION: A pellet-like MDF sander dust and a polypropylene which are cast in a stirring blade type mixer 1 are stirred by stirring blades 13a-13f in a chamber 11. Thereby they collide with each other and collide with a wall face of the chamber 11. Then, a friction heat is generated, they are gradually ground, and a temperature of the polypropylene being a thermoplastic plastic material is gradually raised by the generated friction heat. Then, since the polypropylene is melted in a gel state when it reaches a melting temperature of the polypropylene, the MFD sander dust ground finely following that is uniformly dispersed while it is entangled in the polypropylene of a molten state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a wood-based resin composition containing a cellulosic material and a thermoplastic material.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic material such as polypropylene or polystyrene and a cellulosic material such as wood flour have been charged into a stirring blade type mixer. A wood-based resin composition is produced by mixing a cellulose-based material with a thermoplastic material in a molten state while melting the thermoplastic material by frictional heat generated when the two are stirred in the machine. For example, a wooden composite board is formed using an object.

By the way, as the cellulosic material used for producing the above-mentioned woody resin composition, a powdery or fibrous material such as wood flour produced from wood or the like is usually used. However, when such a granular or fibrous cellulosic material is put into a stirring blade type mixer together with a thermoplastic material and mixed while stirring at high speed, the cellulosic material having a small particle diameter is mixed with the stirring blade type mixing material. There is a problem that the cellulose-based material and the thermoplastic material cannot be efficiently and uniformly mixed in a short time in a machine.

Accordingly, an object of the present invention is to provide a method for producing a woody resin composition capable of efficiently and uniformly mixing a cellulosic material and a thermoplastic material in a short time, and a woody resin obtained by the method. An object of the present invention is to provide a composition and a molded article of the woody resin composition.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a stirring blade for mixing a granular or fibrous cellulosic material granulated into pellets with a thermoplastic material. By throwing into a mold mixer and stirring, the cellulose-based material granulated into pellets is pulverized into fine powder while melting the thermoplastic material, and the cellulosic material pulverized into fine powder is obtained. It is to be mixed with the thermoplastic material in a molten state.

In such a method, the cellulose-based material granulated into pellets is gradually pulverized into fine powder while being stirred, so that the granular or fibrous cellulose-based material is previously stirred together with the thermoplastic material. Cellulose-based materials do not soar in the stirring blade-type mixer, as in the case of being thrown into the blade-type mixer and stirred, and the thermoplastic material and the cellulose-based material are efficiently and uniformly mixed in a short time. Can be.

In the wood-based resin composition produced by such a method, since a cellulose-based material is uniformly dispersed and mixed in a thermoplastic material, a molded article formed by the wood-based resin composition is used. Is of high quality with stable physical properties.

Further, by pelletizing the cellulosic material, it is easy to measure the amount to be charged into a stirring blade type mixer and the like, and the charging operation is facilitated, and there is no danger of dust explosion. There is an effect that the handleability of the material is improved.

Further, when the blending amount of the cellulosic material is set in the range of 50 to 80% by weight as in the production method according to the second aspect, it is possible to obtain from the produced woody resin composition. There is an effect that a texture close to that of a wooden material can be imparted to the molded product.

The above-mentioned "cellulosic material" includes PB chips, dry refiner chips, wet refiner chips, virgin MDF fiber, plywood sander dust, PB sander dust, MDF sander dust, waste MDF fiber, plywood sawdust, PB Sawdust, MDF
Sawdust can be used, and the particle diameter or fiber length is 1
Those having a diameter of 0 mm or less are preferable.

Such a cellulosic material has a diameter of 8 to 10 m by various granulation methods such as a ring die method.
m, length 5-10 mm, bulk density 0.5-0.6 g /
It is desirable to pelletize to about cm ³ , and it is particularly effective to pelletize when the particle diameter of the cellulosic material to be used is 5 mm or less. The density of the pelletized cellulosic material is 1.
0 g / cm ³ or less, more preferably 0.9 g / cm ³ or less.
/ Cm ³ or less. In addition, the above-mentioned cellulose-based materials may be pelletized as a single type, or may be pelletized in a state where a plurality of types are mixed.

The above-mentioned "thermoplastic material" includes polypropylene (PP), polystyrene (PS), polyethylene (PE), polyethylene terephthalate (PET), acrylonitrile butadiene styrene copolymer (ABS), polyvinyl chloride (PVC) or the like or these waste plastics can be used alone or in a mixture of a plurality of types, and a small amount of a thermosetting plastic material may be mixed in these thermoplastic materials. When the thermoplastic material is crushed, the thermosetting plastic material is also crushed into fine powder and dispersed together with the cellulosic material in the molten thermoplastic material, so it does not significantly affect the physical properties of the molded product. It is.

Further, a deodorant such as a metal catalyst (zinc oxide, copper oxide), activated carbon and sodium hydrogen carbonate, and a compatibilizer (eg, maleic anhydride) for strengthening the bond between the cellulosic material and the thermoplastic material. Modified polypropylene) and a lubricant (eg, wax, paraffin, butyl stearate, methyl stearate) for improving the fluidity of the mixture can be appropriately added.

The molded wood-based resin composition can be subjected to press molding, roll (continuous) press molding, extrusion molding or the like in a molten state to produce various molded articles such as a synthetic wood board. . Concretely, floor base materials and panel base materials for floor heating panels with hot water tube receiving grooves are suitable for press molding, and floor panels and control panels are suitable for roll press molding. , Exterior moldings (such as wood decks), building structural members (such as building pillars), construction materials (surrounding edges, sills, window frames, etc.) are suitable for extrusion molding. The floor panel and control panel can also be manufactured by press molding.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First, the MDF sander dust was granulated by a ring die granulator (75HP, manufactured by CPM) to have a diameter of 8 to 10 mm and a length of 5 to 10 m.
m, and pelletize to a bulk density of about 0.5 to 0.6 g / cm ³ . Then, 120 g of MDF sander dust pelletized as a cellulosic material and 80 g of polypropylene as a thermoplastic material were charged into a stirring blade type mixer 1 as shown in FIG. 1 and stirred for about 50 seconds.

As shown in FIG. 1, the stirring blade type mixer 1 has a rotating shaft 12 horizontally supported by a bearing (not shown) penetrating a chamber 11 having a horizontal cylindrical shape.
The rotating shaft 12 has six stirring blades 13a, 13b, 13
c, 13d, 13e and 13f are provided.

Of the six agitating blades 13a to 13f, the two agitating blades 13a and 13f at both ends prevent the molten thermoplastic material from adhering to the inner surfaces of both end walls of the chamber 11. In addition, it is attached to the rotating shaft 12 so as to slide on the inner surfaces of both end walls of the chamber 11.

On the other hand, four stirring blades 13b, 13c, 13d, and 13e located at an intermediate portion in the chamber 11 are provided.
Is used to increase the collision efficiency by guiding the input material to the center of the chamber 11 and to uniformly mix the materials. The materials are staggered on the outer peripheral surface of the rotating shaft 12, and the tip has an angle of about 15 degrees. Twisted.

The chamber 11 has a material supply port 1.
1a and a mixture discharge port 11b are respectively formed, and the material supplied to the hopper 15 is moved from the material supply chamber 16 to the material supply port 11a by a spiral material supply screw 14 provided on the outer peripheral surface of the rotating shaft 12. It is supplied to the inside of the chamber 11. The mixture discharge port 11b is closed by an open / close door (not shown).

The pellet-shaped MDF sander dust and polypropylene fed into the stirring blade type mixer 1 are stirred by the stirring blades 13a to 13f in the chamber 11 to collide with each other, or to impinge on the stirring blades 13a to 13f.
By colliding with the wall 13f or the wall of the chamber 11, frictional heat is generated and crushed gradually, and the generated frictional heat gradually raises the temperature of polypropylene, which is a thermoplastic material. The capacity of the stirring blade type mixer 1 used was 1 L, and the stirring blades 13 a to 13 f were rotated at a high speed so that the tip speed was about 30 m / sec.

As described above, the temperature of the input material is gradually increased while being pulverized by stirring, and when the temperature reaches the melting temperature of the polypropylene, the polypropylene is melted in a gel state. The MDF sander dust is uniformly dispersed while being entrained in the molten polypropylene, and finally becomes a gel-like wood-based resin composition in which the polypropylene and the fine powdered MDF sander dust are uniformly mixed. It is discharged from 11b.

A woody synthetic board was produced by cold-pressing the gel-like woody resin composition thus obtained at a pressure of about 40 kgf / cm ² . This wood composite board had excellent dimensional stability and sufficient physical strength, and was of high quality with stable physical properties.

As described above, according to this method for producing a woody resin composition, the powdered MDF sander dust is not charged into the stirring blade type mixer 1 as it is, but is granulated in the form of pellets in advance. In this state, the mixture is put into the stirring blade type mixer 1, and is stirred with the thermoplastic polypropylene material so as to be gradually pulverized into fine powders while raising the temperature. In the initial stage of stirring when the MDF sander dust cannot be taken into the polypropylene,
When the temperature rises and the polypropylene begins to melt without the presence of the F sander dust, the pelletized MDF sander dust is pulverized into a fine powder. As in the case where the powder is fed into the stirring blade type mixer 1 as it is, the powdered MDF sander dust does not soar in the stirring blade type mixer 1 due to the stirring, and the polypropylene and the MDF sander dust are efficiently separated. Uniform mixing can be achieved in a short time.

Further, by pelletizing the MDF sander dust, which is a cellulosic material, it becomes easy to measure the amount to be charged into a stirring blade type mixer and the like, and the charging operation is facilitated, and the danger of dust explosion is reduced. M
There is an effect that the handleability of a powdery cellulosic material such as DF sander dust is improved.

In this embodiment, the blending amount of MDF sander dust which is a cellulose-based material is 60% by weight. However, the blending amount of the cellulose-based material is determined in consideration of physical properties required for the final molded product. , 50 to 80% by weight. Cellulose-based compounding amount is 5
If the amount is less than 0% by weight, the texture of the wood material cannot be imparted to the final molded product. If the amount of the cellulosic material is more than 80% by weight, the amount of the thermoplastic material functioning as a binder is too small. This is because sufficient strength cannot be ensured for the final molded product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing a stirring blade type mixer used for carrying out a method for producing a woody resin composition according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stirring blade type mixer 11 Chamber 12 Rotation axis 13a, 13b, 13c, 13d, 13e, 13f Stirring blade 14 Material supply screw 15 Hopper 16 Material supply chamber

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jiro Nishio 2-10-60 Hirabayashi-minami, Suminoe-ku, Osaka-shi, Osaka Inside Eidai Sangyo Co., Ltd. (72) Inventor Akira Nakamura 2 Hirabayashi-minami, Suminoe-ku, Osaka, Osaka No. 10-60, Eidai Sangyo Co., Ltd. (72) Eiji Yamano 2-10-60, Hirabayashi Minami, Suminoe-ku, Osaka City, Osaka Prefecture F-term, Eidai Sangyo Co., Ltd. BC01 BC02 BC12 BC17 BC19 BC37 BD02 BD05 BK15 BN15 BN29 BN30 4J002 AB011 BB032 BB122 BD042 BN152 CF062 FD170 FD200

Claims (4)

[Claims] 1. A thermoplastic resin material and a powdery or fibrous cellulosic material formed into pellets and a thermoplastic plastic material are put into a stirring blade type mixer and stirred to melt the thermoplastic plastic material. A wood-based resin composition in which the cellulosic material granulated into pellets is pulverized into fine powders while being mixed, and the cellulosic material pulverized into fine powders is mixed with the thermoplastic material in a molten state. Manufacturing method. 2. The compounding amount of the cellulosic material is 50 to 50.
The method for producing a woody resin composition according to claim 1, wherein the amount is 80% by weight. 3. A wood-based resin composition produced by the method according to claim 1. 4. A molded article molded using the woody resin composition according to claim 3.