JPH05318420A - Structural composite material - Google Patents

Abstract

PURPOSE:To relatively inexpensively provide a structural composite material by using a material having required mechanical strength, low in water absorbability, excellent in weatherability and capable of achieving the effective utilization of resources. CONSTITUTION:A structural composite material is obtained by subjecting a mixture consisting of 30-60wt.% of a vulcanized rubber powder with a particle size of 1.5mm or less obtained by grinding a rubber tire, 30-60wt.% of small wooden pieces (diameter, 0.5-2mm, length, 1-6 m) of a pine material and 8-20wt.% of a phenol resin, a urea resin or other thermosetting resin to hot- pressing molding at 120-200 deg.C under pressure of 20-80kg/cm<2>.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structural composite material used as a general-purpose structural material such as plate and square.

[0002]

2. Description of the Related Art Generally, wood, synthetic resin, etc. are known as general-purpose structural materials for building materials and other plate materials and square materials, and also serving as materials such as pallets for transportation.

Such structural materials are required to have required mechanical strength such as bending strength, tensile strength and compressive strength when they are used for the above various uses.

[0004] In addition, considering that the raw materials are inexpensive and can be supplied in large quantities, and that they are used outdoors, they are required to have weather resistance such that they are not easily exposed to sunlight or deteriorated under humid conditions.

[0005]

However, among the above, the wooden structural material has a problem that it has water absorbability and is easily deteriorated by the action of sunlight, microbial decomposition, etc., and has a short outdoor service life. There is a point. Further, it is not preferable to use a large amount of wood as a consumable item under severe usage conditions from the viewpoint of effective use of resources, and it is difficult to stably secure raw materials.

[0006] When synthetic resin is used as a structural material, it is possible to add a fiber material to strengthen it, but it is difficult to obtain sufficient strength at a low cost with a fiber material. Furthermore, it has been known to pulverize a waste tire which is a vulcanized rubber and use this as an extender,
Its use was limited to the extent that it was added (less than 30% by weight), and there was no satisfactory one as a structural composite material using vulcanized rubber as a main raw material.

According to the present invention, the above-mentioned problems can be solved and a structural composite material can be provided at a relatively low cost by providing required mechanical strength, excellent weather resistance, and effective use of resources. The task is to do.

[0008]

In order to solve the above-mentioned problems, in the present invention, 30-60% by weight of vulcanized rubber is used.
And 30-60% by weight of wood chips and 8-2 thermosetting resin
The composition was obtained by thermocompression molding of a mixture containing 0% by weight as a main component.

[0009]

In the structural composite material of the present invention, the vulcanized rubber compounded in a predetermined ratio serves as a matrix and is mixed with the highly rigid wood chips, and when thermocompression-molded, they form a thermosetting resin. Since it is integrally bonded and fixed via the above, it has excellent mechanical strength such as bending strength, tensile strength, and compression strength. The small pieces of wood are mixed independently of each other, and the vulcanized rubber intervenes between them to prevent water from permeating therethrough, resulting in low water absorption and excellent weather resistance. Further, since the properties of the vulcanized rubber are properly exhibited by the above-mentioned compounding ratio, the vulcanized rubber is resistant to impact and fatigue, and has vibration damping properties.

[0010]

EXAMPLES The vulcanized rubber used in the present invention is not particularly limited, and is a synthetic rubber such as styrene-butadiene rubber (hereinafter abbreviated as SBR) and isoprene rubber (hereinafter abbreviated as IR). Based rubber, butyl rubber (hereinafter abbreviated as IIR), other olefinic rubber or natural rubber (NR), or a mixture thereof can be used. The production cost of such a vulcanized rubber can be reduced by diverting a commercially available rubber automobile tire. Most of passenger car tires currently use SBR as a main material, and truck tires use IR that can withstand heavy loads, while tubeless tire inner liners consist of air impermeable IR. .. Such a rubber tire is used after being pulverized by a crusher.
In this case, as a method of pulverizing the vulcanized rubber, a roll type or other pulverizer is used to obtain powder having a diameter (φ) of 1 to 2 mm or less, and the mixed metal is attached by magnetic attachment or the like. Remove and use.

Next, the wood piece used in the present invention is not particularly limited to a tree as a material thereof and may be, for example, pine, cedar, cherry tree, lauan, etc., and thinned wood, sawdust, etc. can also be used. .. The above-mentioned small pieces of wood are crushed into rod-like pieces having a diameter of 0.5 to 2 mm and a length of about 1 to 6 mm so as to be easily mixed uniformly with the vulcanized rubber powder and granules.

The thermosetting resin used in the present invention is preferably a phenol resin (phenol / formaldehyde resin), a melamine resin (melamine / formaldehyde resin), a urea resin or the like because of good moldability. Further, it goes without saying that a plurality of types of the thermosetting resin as described above may be blended or a copolymer may be used.

The mixing ratio of the above raw materials is such that the vulcanized rubber 3
It is 0 to 60% by weight, wood particles 30 to 60% by weight, and thermosetting resin 8 to 20% by weight. This is because when the amount of the vulcanized rubber used as the matrix is less than 30% by weight, the impact resistance and vibration resistance peculiar to the rubber material are low, and when the amount exceeds 60% by weight, the mechanical strength decreases. Also,
When the amount of the thermosetting resin is less than 8% by weight, the mechanical strength cannot be sufficiently obtained, and when the amount is more than 20% by weight, the cost becomes high and it is not practical. Loses its elasticity.

The molding conditions for the structural material may be the same as those for general thermosetting resins, and the molding temperature is 120-2.
The temperature may be 00 ° C. and the pressure may be ²⁰ to 80 kg / cm ² as a guide. Also, the molding time is 30 to 60 seconds per 1 mm of plate thickness, and molding of the required thickness can be performed. Further, a general preheating or post-curing method may be used together to shorten the molding time.

[Example 1] 500 g of a vulcanized rubber powder having a particle size of 1.5 mm or less obtained by crushing a truck tire and 340 g of pine wood crushed chips (length of 6 mm or less) were mixed with a Shinagawa mixer for 1 minute. After that, add 160g of liquid phenol resin and add 4
Mix for minutes. Next, 600 g of this mixture was put into a mold and pressure-molded at room temperature at a pressure of 40 kg / cm ² for 1 minute using a hydraulic press machine to obtain a preform (hereinafter referred to as a tablet).

The obtained tablets were placed in a mold heated to 150 ° C., and thermoformed by a hydraulic press at a pressure of 30 kg / cm ² for 30 minutes to form a thick plate (100 mm × 200 mm × 30 mm).
Thus, a structural composite material having a weight of 570 g was obtained.

[Example 2] The same vulcanized rubber powder 3 as in Example 1
50g, wood chips 550g, liquid phenol resin 10
0 g was mixed exactly as in Example 1. Next, 300 g of this mixture was placed in a mold and pressure-molded for 1 minute at a pressure of 60 kg / cm ² at room temperature using a hydraulic press machine to obtain tablets.

This tablet was placed in a mold heated to 180 ° C. and thermocompressed with a hydraulic press at a pressure of 50 kg / cm ² for 10 minutes to form a thin plate (100 mm × 200 mm × 15 mm).
Thus, a structural composite material having a weight of 282 g was obtained.

[Example 3] Vulcanized rubber powder 3 which is the same as in Example 1
00g, wood chips 550g, and liquid urea resin 150
g were mixed exactly as in Example 1. Then mix 3
Tablets were obtained by press-molding 00 g under the same conditions as in Example 2.

The obtained tablet was placed in a mold heated to 135 ° C. and heat-pressed for 10 minutes with a hydraulic press at a pressure of 25 kg / cm ² to obtain a thin plate (100 mm × 200 mm × 15 m).
m), a structural composite material weighing 279 g was obtained.

Here, a test piece was prepared for each of the obtained Examples 1 to 3, and the specific gravity, bending strength (kg / cm ² ), and tensile strength (kg / kg) were measured by the test method of JISK6915. c
m ² ) and compressive strength (kg / cm ² ) were determined, and the respective results are shown in Table 1. For each test, the raw material pine wood was used as a comparative example, and the results are also shown in Table 1.

[0022]

[Table 1]

As is clear from the results shown in Table 1, Example 1
Nos. 3 to 3 have bending strength equal to or higher than that of the pine wood of Comparative Example,
The compressive strength was improved four times or more. In addition, a pallet for transportation was actually manufactured by adhesion, and a product having extremely good weather resistance was obtained, and the production cost could be kept low.

[0024]

[Effects] As described above, the present invention provides a vulcanized rubber,
Small pieces of wood and thermosetting resin are mixed in a prescribed ratio and integrally molded, so it has the required mechanical strength as a structural composite material, has vibration absorption, and has low water absorption and weather resistance. Excellent in performance. In addition, rubber tires can be reused as a raw material and can be manufactured at a relatively low cost, and in particular, it can be molded into a pallet for transportation, general-purpose square timbers, plate materials or floor materials that utilize its vibration-proofing properties to provide excellent structural materials. There are advantages.

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[Procedure amendment]

[Submission date] May 27, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

[0021] Here, with respect to Examples 1 to 3 obtained above, and a test piece at JISK691 1 test method, the specific gravity, bending strength (kg / ^cm 2), tensile strength (kg
/ Cm ² ), and compressive strength (kg / cm ² ),
The respective results are shown in Table 1. For each test, the raw material pine wood was used as a comparative example, and the results are also shown in Table 1.

Claims (2)

[Claims] 1. A structural composite obtained by thermocompression molding a mixture containing 30-60% by weight of vulcanized rubber, 30-60% by weight of wood chips, and 8-20% by weight of thermosetting resin. material. 2. The structural composite material according to claim 1, wherein the vulcanized rubber is a crushed product of a rubber tire.