JP2002225011A - Woody composition for molding and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody composition for molding effectively utilizing a woody waste to be discharged in a manufacturing industry of a furniture, a building material or the like, and a method for efficiently manufacturing the same at a low cost. SOLUTION: The method for manufacturing the woody composition for molding comprises the steps of mechanically comminuting a mixture of the woody waste, a polyolefin, a maleic acid or a maleic anhydride modified polyolefin at 120 to 190 deg.C until compositing is substantially completed, and then pelletizing the mixture at 110 deg.C or lower to obtain the woody composition obtained by mechanochemically compositing a wood flour, the polyolefin, and the maleic acid or the maleic anhydride modified polyolefin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a woody composition for molding utilizing woody waste discharged in the manufacturing industry of furniture, building materials and the like, and a method for efficiently and inexpensively manufacturing this composition. It is.

[0002]

2. Description of the Related Art In recent years, the importance of resource-recycling social and economic systems that reduce industrial waste and reduce environmental pollution has been recognized. In the field, the Containers and Packaging Recycling Law and the Home Appliance Recycling Law have been enacted, and the reuse of wood-based industrial waste and plastic industrial waste has become a socially required issue.

[0003] For this reason, wood-based industrial waste, for example, the use of wood discharged from house demolition, which is currently limited in use, is used, and plastic industrial waste, for example, is discharged in the process of manufacturing and processing plastic products. The use of plastic waste and crushed waste plastics such as injection molded polypropylene used in refrigerators and other light electrical appliances collected as waste can be reduced by the Building Recycling Law, the Containers and Packaging Recycling Law, and the Home Appliance Recycling Law. Various studies have been made to achieve the purpose.

[0004] In a conventional wood-based compound for extrusion molding obtained by mixing or compounding a wood-based material and a general-purpose resin, the content of the wood-based material is usually 30 to 50.
% By mass, at most 60% by mass. In the production of the wood-based compound, wood-based material is first crushed by a device having a mechanism such as a ball mill to obtain wood flour having no whisker-like portions. It is necessary to take a complicated method of adding and mixing a polyolefin and a maleic acid-grafted polyolefin to a diameter of about 0.1 mm or less, and then it takes a long time to obtain fine wood flour used for this. Processing had to be done.

On the other hand, instead of using an expensive maleic acid-grafted polyolefin, wood, polypropylene, maleic anhydride and a grafting initiator are simultaneously charged into an extruder and mixed and reacted in a cylinder of the extruder. [Journal of the Japan Wood Research Society, Vol. 35, No. 12
Vol. 1, pp. 1100-1104 (1989), Vol. 36, No. 11, pp. 976-982 (1990)
Year)]. However, in this method, in the extruder cylinder, polypropylene and maleic anhydride must be reacted with the initiator or the antioxidant at the same time, but since these raw materials have high viscosity and low flowability, The mixing and the reaction became uneven, and the reaction between the wood and the maleic anhydride group was inevitable.

[0006] In general, wood-based materials contain a relatively large amount of water, and in some cases, 10% by mass or more of water. Therefore, when a wood-based compound is heat-formed, foaming or hydrolysis of the wood-based material is caused by the water. In addition, it causes deterioration such as polyolefins and deteriorates the physical properties and quality of the molded product, and also causes inconveniences such as hydrolysis of the maleic anhydride group to lower its reactivity. Therefore, in order to use it as a raw material for woody compounds, the woody material must be
A sufficient drying treatment was required, which inevitably increased the cost.

[0007] By the way, the main chemical component of the wood-based substance is cellulose, and various other substances such as hemicellulose, carbohydrate, and lignin are also contained, and many substances are hydrophilic. It is difficult to simply form a composite with a hydrophobic polyolefin by hot-melt kneading, etc. due to differences in chemical properties. If substances having different chemical properties are kneaded, the dispersion of the respective substances tends to be non-uniform in the product, and the deterioration of the molding processability and the physical properties of the obtained molded article is inevitable. In addition, a relatively long kneading time is required to more uniformly disperse and mix, and during that time, there is a disadvantage that the wood component is easily decomposed.

In addition, when a mixture of a woody substance and a polyolefin is simply put into an extruder, the mixture is melted and kneaded by a screw inside a cylinder, and the mixture is extruded. Even if powdered, relatively large aggregates are generated, and the dispersion is likely to be uneven. This non-uniformity increases the viscosity during extrusion molding, and also increases the die pressure, resulting in undesirable situations such as inability to extrude or applying an excessive load to the extruder and causing damage to the apparatus.

In order to enhance the dispersibility and mixing properties of the wood-based material and the polyolefin, and to enhance the physical properties of the produced molded product, a modified polyolefin, particularly a maleic acid-grafted polyolefin, is generally used as a compatibilizer. I have. This modified polyolefin is widely used as an adhesive layer of a general-purpose resin film and the like, and is also often used for producing a composite material of a wood-based material and a polyolefin.

However, when extruding a mixture of a wood-based material containing a wide variety of materials with a polyolefin and a modified polyolefin, the conventional method of hot-melt kneading in an extruder decomposes and disperses the wood-based material. Becomes uneven,
It is inevitable that the quality of the obtained molded body is partially deteriorated. If the amount of the expensive modified polyolefin added is increased in order to improve the physical properties of the molded article, the cost is inevitably increased. Under these circumstances, it is important today to obtain a high quality woody composition for molding using woody materials without using expensive processing agents and without much trouble. It has become a challenge.

[0011]

SUMMARY OF THE INVENTION Under such circumstances, the present invention provides a high quality molded product by effectively utilizing woody waste discharged in the manufacturing industry such as furniture and building materials. The object of the present invention is to provide a woody composition for molding easily and at low cost.

[0012]

The present inventors have previously developed a technique for producing a heat-moldable composite from a natural polymer compound and a synthetic or other natural polymer compound by mechanical pulverization. [Patent No. 3099064, "Chemistry Letters (Chem. Letters)", No. 11
55-1156 (1999)], and as a result of further research, they found that if this technology was used, wood flour, a polyolefin, and maleic acid or maleic anhydride-modified polyolefin could be easily compounded.
The present invention has been accomplished based on this finding.

That is, the present invention provides a woody composition for molding obtained by mechanochemically compounding wood flour, a polyolefin, and a polyolefin modified with maleic acid or maleic anhydride under dry conditions, and a woody substance. And a mixture of polyolefin and maleic acid or maleic anhydride-modified polyolefin is subjected to mechanical pulverization at 120 to 190 ° C. until the complexation is substantially completed.
It is intended to provide a method for producing a woody composition for molding, which is characterized by lowering the temperature to not more than ° C and pelletizing.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The woody composition for molding of the present invention comprises:
Wood flour, polyolefin and maleic acid or maleic anhydride-modified polyolefin are mechanochemically compounded under dry conditions, and can be obtained by mechanically pulverizing a mixture of each component. .

By this mechanical pulverization treatment, each component becomes fine particles, is uniformly dispersed, and forms a composite compounded at the molecular level. At this time, the maleic acid or maleic anhydride-modified polyolefin interacts with a woody substance having a large number of chemical components such as cellulose having a maleic acid group or a maleic anhydride group portion in the molecule having many hydroxyl groups, and a polyolefin main chain portion. Interacts with the polyolefin.
That is, the maleic acid or maleic anhydride-modified polyolefin functions as a compatibilizer.

As the wood flour used in the composition of the present invention, wood-based waste such as wood scraps and canned waste discharged in the manufacturing and processing steps of furniture and building materials, and wood discharged from house demolition can be used. Can be mentioned.
In particular, the use of wood from house demolition, which is currently limited, can contribute to the promotion of the Building Recycling Law.

On the other hand, as the polyolefin, polyolefin waste discharged in the manufacturing process of plastic products and crushed waste plastic such as injection-molded polypropylene used in refrigerators and the like for light electric appliances collected as waste are used as raw materials. Can be mentioned.
Use of such plastic industrial waste can contribute to the promotion of the Containers and Packaging Recycling Law and the Home Appliance Recycling Law.

Examples of the polyolefin include polyethylene, polypropylene, polybutylene, and poly4-
A homopolymer such as methylpentene-1, a copolymer of ethylene and propylene, a copolymer of ethylene and butylene, and a copolymer of ethylene and another α-olefin having 5 or more carbon atoms, that is, a low density line Copolymers such as linear polyethylene can be used. These may be used alone or as a mixture of two or more. Among these, polyethylene or polypropylene or a mixture thereof is particularly preferred.

Next, the maleic acid or maleic anhydride-modified polyolefin is not particularly limited, and conventionally known polyolefins can be used. This modified polyolefin is, for example, polyethylene, polypropylene, ethylene-
α-olefin copolymer, ethylene-α-olefin-
Polyolefins such as non-conjugated diene compound copolymer (such as EPDM) and ethylene-aromatic monovinyl compound-conjugated diene compound copolymer rubber are graft-copolymerized with maleic acid or maleic anhydride and chemically modified. . This graft copolymerization is carried out, for example, by reacting the polyolefin with maleic acid or maleic anhydride in a suitable solvent using a radical generator such as benzoyl peroxide.

Since this modified polyolefin has a carboxyl group or an acid anhydride group in the molecule, these portions easily react with the hydroxyl group-containing component in the wood flour to exhibit an affinity, and the polyolefin main component. Since the chain portion has an affinity for the polyolefin used in combination, it acts as a compatibilizer between the wood flour and the polyolefin. As described above, since the modified polyolefin acts as a compatibilizer, the coexistence of the modified polyolefin can significantly increase the content ratio of wood flour to the polyolefin.

The content ratio of each component in the woody composition for molding of the present invention is not particularly limited. However, in view of the moldability of the composition and the physical properties of the obtained molded product, wood powder 1
It is preferable that the composition contains 10 to 20 parts by mass of a polyolefin and 1 to 5 parts by mass of a polyolefin modified with maleic acid or maleic anhydride per 100 parts by mass.

Further, the woody composition for molding of the present invention includes:
If desired, various additives conventionally used in polyolefin-based molding materials, such as plasticizers, stabilizers, reinforcing agents,
Contains antioxidants, ultraviolet absorbers, light stabilizers, metal deactivators, flame retardants, flame retardant aids, antistatic agents, lubricants, mold release agents, coloring agents, fungicides, etc. at their respective effective concentrations can do.

The woody composition for molding of the present invention is prepared by reacting wood flour, polyolefin, and maleic acid or maleic anhydride-modified polyolefin while applying mechanical energy under dry conditions. The hydroxyl group-containing component, the polyolefin, and the modified polyolefin react at a molecular level mechanochemically to form a composite and exhibit thermoplasticity. Therefore, when molding with an extruder, it is possible to reduce the time required for kneading operation in a cylinder and the like, and it is possible to suppress the decomposition and deterioration of wood flour containing many components that are easily decomposed by heat. .

The woody composition for molding of the present invention can be prepared in the same manner as a general polyolefin-based molding material by a known molding method such as press molding, extrusion molding or injection molding. And molded articles such as films and sheets. For example, it is supplied to an oblique twin-screw extruder equipped with a deformed mold, and under appropriate conditions, for example, a die pressure of 10 to 20 MPa and a cylinder temperature of 180 to 21.
By extrusion molding at 0 ° C. and a die temperature of 160 to 200 ° C., it is possible to produce an extruded molded article composed of a composite of wood flour containing at least 80% by mass of wood flour and polyolefin.

According to the method for producing a woody composition for molding of the present invention, a mixture of a woody substance, a polyolefin, and a maleic acid or maleic anhydride-modified polyolefin is mixed with 120 wt.
After performing mechanical pulverization treatment until the complexing is substantially completed at ~ 190 ° C, the temperature is lowered to 110 ° C or lower and pelletized, whereby a woody composition for molding can be produced. In addition, in order to facilitate the compounding of the mixture of the wood-based material and the polyolefin and the modified polyolefin, if necessary, a solid or liquid polymer material, a low-molecular material, an inorganic compound, and the like may be added to the mixture in addition to the above components. Can be added.

FIG. 1 is a process chart showing an example of a method for producing a woody composition for molding of the present invention. Here, as a raw material of the wood flour, a wood-based substance such as the above-mentioned wood-based waste is used, and since this often contains a relatively large amount of water, the maleic acid group or the maleic acid group in the modified polyolefin is often used. It is preferable to reduce the water content to 10% by mass or less by a hot air drying treatment, a vacuum drying treatment, or the like in order to suppress a decrease in the interaction capability of the maleic anhydride group and foaming during molding.

This woody waste contains a lot of planer waste, sawdust and wood scraps, and generally has a low bulk density (about 0.01 kg / liter) and is bulky. Inconvenient. Therefore, when the woody waste has a large shape, it is preferable to reduce the volume in a powder or pellet form in advance using a volume reducer in order to end the compounding efficiently and in a short time.

On the other hand, polyolefin, maleic acid or maleic anhydride-modified polyolefin can be directly mixed with woody waste and compounded by mechanical pulverization if the particle size is about 5 mm or less. In order to perform the compounding efficiently and in a short time, it is preferable to use a cutting mill or the like to make the particles into a particle diameter of 1 mm or less in advance.
When a commercially available powdered polyolefin or powdered maleic acid or maleic anhydride-modified polyolefin is used, it may be used for direct compounding.

Next, to 100 parts by mass of the woody waste,
About 10 to 20 parts by mass of the polyolefin, and 1 to 5 of the maleic acid or maleic anhydride-modified polyolefin.
Approximately parts by mass are added, and if necessary, various additives are added in appropriate amounts and mixed, and the mixture is subjected to mechanical pulverization using a ball mill or a high-speed mixer in the absence of a solvent.

In the mechanical pulverizing treatment, the woody waste is pulverized in the initial stage and further reduced in volume. The temperature rises due to the frictional heat of the pulverization. If necessary, the pulverizer is externally heated with a heating heat medium, steam, or the like, and mechanical pulverization is performed at a temperature in the range of 120 to 190 ° C. At this time, the polyolefin is plasticized and softened or melted. The time until the completion of the compounding depends on the temperature and the amount of mechanical energy at that time, but is usually about 20 to 120 minutes. If the composite thus obtained is cooled while stirring to 110 ° C. or lower, it can be formed into granules or pellets, and can be directly used for molding. The size of the granules or pellets at this time can be controlled by the shape of the stirring blade, the number of revolutions, the cooling conditions and the like.

The woody waste usually has a water content of 10% by mass or more. However, even if the woody waste is used as a raw material without being dried, it can be used as a raw material in the mechanical pulverization treatment of the present invention. Since the temperature rises uniformly, the water evaporates or disperses, and the water content of the resulting woody composition for molding is usually 0.8% by mass or less. Therefore, the woody composition for molding can be molded as it is without drying treatment. However, if the woody composition for molding is left unnecessarily, it causes moisture absorption. After that, it is preferable to use it promptly.

According to the method of the present invention, a woody composition for molding compounded at the molecular level can be produced only by mechanical pulverization, so that the production equipment is simple and the production cost is low. There are advantages. In addition, even when the obtained wood-based composition has a high wood powder content, it is thermoplasticized itself, so molding is easy, improving productivity and extending the life of the molding machine. Can be. Furthermore, when the woody composition for molding obtained by the method of the present invention is put into a twin-screw extruder having an oblique shaft, the composition at the time of extrusion is compared with the woody composition obtained by mixing with an ordinary mixer. The torque is low, and the physical properties of the extruded molded body are greatly improved.

[0033]

According to the present invention, wood-based waste discharged in the manufacturing industries such as furniture and building materials is combined with polyolefin and modified polyolefin, and reused as a molding material in the same manner as general thermoplastic resins. Therefore, it is possible to provide a technology useful as one of the resource recycling industries. In particular, if wood that can be used as debris from house demolition can be used as a woody waste, it can contribute to the promotion of the Building Recycling Law, and it can be used as a polyolefin in the processing of plastic products. The use of waste polyolefin waste and crushed waste plastics such as injection-molded polypropylene used in refrigerators and other light electrical appliances recovered as waste can promote the Containers and Packaging Recycling Law and the Home Appliance Recycling Law. Can contribute.

[0034]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

EXAMPLE As woody waste, canna waste and sawdust of poplar material discharged in the furniture manufacturing process were used. Polypropylene was used as a polyolefin [trade name "MS-79" manufactured by Tokuyama Corporation.
1 ", melt flow rate (MFR) 60 g / 10 min]
Was used as the modified polyolefin, maleic anhydride-grafted polypropylene [trade name “UMEX CA-60” manufactured by Sanyo Chemical Industries, Ltd.]. 1.8 parts by weight of a modified polyolefin is added to a mixture of 85 parts by weight of woody waste and 15 parts by weight of polypropylene, and this mixture is mixed with a high-speed mixer [SGM-10, manufactured by Kawata Corporation].
0 "], and the mixer blade is set at 1500 to 2000 rpm.
m and high-speed stirring and pulverization for 30 minutes. The temperature at this time is 15 degrees due to frictional heat and heat from the high-speed mixer main body.
The rotation speed was adjusted to raise the temperature to 0 ° C. After high-speed stirring and pulverization, the obtained composite was transferred to a cooling mixer equipped with a cooling tank [trade name "SMC-100" manufactured by Kawata Corporation) and pelletized by low-speed stirring at 100 ° C for 30 minutes. Was carried out to produce a woody composition for molding.

Next, the woody composition for molding obtained in this way is introduced into a twin-screw extruder having a deformed mold and an oblique shaft, a screw rotation speed of 12 rpm, and a cylinder temperature of 180 to 210 ° C. Extruded at a die temperature of 180 ° C,
A plate-shaped molded plate was produced. At this time, the motor torque and the die pressure of the molding machine were measured, and the plate-like molded body was cut into a predetermined size, and a bending strength test was performed. Table 1 shows the results.

COMPARATIVE EXAMPLE In the example, a woody composition for molding was produced in the same manner as in the example using a mixing mixer instead of the high-speed mixer, and then a plate-like molded article was produced with a twin-screw extruder. .
At this time, the motor torque and the die pressure of the molding machine were measured in the same manner as in the example, and the plate-shaped molded body was cut into a predetermined size, and a bending strength test was performed. Table 1 shows these results.
Shown in

[0038]

[Table 1]

As can be seen from Table 1, in the case of a plate-like molded product obtained by molding the woody composition for molding produced by using the high-speed mixer of the example, the molding produced by using the ordinary mixer of the comparative example was used. As compared with the case where a wood-based composition is molded, the motor torque of the extruder can be reduced by about 50%, the die pressure can be reduced by 23%, and the bending strength can be reduced by 24% when dried.
%, And 25% when wet.

[Brief description of the drawings]

FIG. 1 shows a method 1 for producing a woody composition for molding of the present invention.
Process drawing showing an example.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kitagawa 529-4 Asano, Kagawa-cho, Kagawa-gun, Kagawa Prefecture Inside (72) Inventor Masaaki Isaya 529-4 Asano, Kagawa-machi, Kagawa-cho, Kagawa-gun, Kagawa (72) Inventor Nobuyuki Kubo 529-4 Asano, Kagawa-cho, Kagawa-gun, Kagawa Prefecture Inside Taiyo Gosei Co., Ltd. Inside Shikoku Institute of Industrial Technology (72) Inventor Koichi Moriya 587-1 Go Higashi-cho, Takamatsu City, Kagawa Prefecture Inside the Kagawa Prefectural Industrial Technology Center (72) Kazuya Ohkita 587-1 Go Higashi-cho, Takamatsu City, Kagawa Prefecture Kagawa Sangyo F-term in technical center (reference) 2B260 BA02 BA15 BA18 CA02 CB01 CD02 CD23 DA07 DB21 DC06 DC08 DC14 EA03 EA12 EA13 EB05

Claims (5)

[Claims] 1. A woody composition for molding obtained by mechanochemically compounding wood powder, a polyolefin, and a maleic acid or maleic anhydride-modified polyolefin under dry conditions. 2. The woody composition for molding according to claim 1, comprising 10 to 20 parts by mass of polyolefin and 1 to 5 parts by mass of polyolefin modified with maleic acid or maleic anhydride per 100 parts by mass of wood flour. 3. The woody composition for molding according to claim 1, wherein the polyolefin is at least one selected from polyethylene and polypropylene. 4. A mixture of a wood-based material, a polyolefin and maleic acid or maleic anhydride-modified polyolefin,
A method for producing a woody composition for molding, comprising: performing mechanical pulverization treatment at 120 to 190 ° C. until compounding is substantially completed; and then lowering the temperature to 110 ° C. or less and pelletizing. 5. The method according to claim 4, wherein 10 to 20 parts by weight of polyolefin and 1 to 5 parts by weight of maleic acid-modified polyolefin are used per 100 parts by weight of the woody substance.