JPH10259256A - Polyolefin resin composition containing cork powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of expressing excellent physical properties and stain resistance and being used for building members such as floor materials and wall materials by compounding a polyolefin resin having a specific flexural modulus and cork powder having a specific average particle diameter in specific amounts, respectively. SOLUTION: This polyolefin resin composition comprises (A) 100 pts.wt. of a polyolefin resin (preferably polypropylene resin) having a flexural modulus of 2000-10000kgf/cm<2> and (B) 15-150 pts.wt. of cork powder having an average particle diameter of 200-5000μm. The composition can be molded into a sheet- like product by the use of heated rolls or calender rolls. The molding temperature is preferably 150-200 deg.C. The molded sheet preferably has a thickness of 0.5-10mm. The molded product can be used as an interior wall material as such, and further be laminated to a woody material such as a plywood through an adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyolefin resin composition containing cork powder. In particular, the present invention relates to a polyolefin-based resin composition suitable for a floor material, a wall material, a ceiling material, a member of furniture, and the like for a building interior, and a molded article based thereon.

[0002]

2. Description of the Related Art Cork is a natural material obtained from cork oak and is not made of plant fibrous material such as ordinary trees, but is made of aggregates of fine cells and pores. These cells are neatly arranged without gaps, and each is independent including air. Cork made of cork with such a structure,
Lighter than wood, etc., excellent in heat insulation, soundproofing, elasticity, abrasion resistance, etc., taking advantage of its characteristics, building materials such as flooring and wall materials, sealing materials such as cork stoppers, daily miscellaneous goods, decorative accessories Widely used until.

[0003] In general, cork as the bark of cork oak is
Used as is for cork stoppers. On the other hand, a large amount of shavings produced during the cork stopper manufacturing process are squeezed and pulverized, an adhesive is added to the obtained cork particles, a block is made with heat and pressure, and the cork sheet is sliced to a required thickness. Various methods have been devised for effective use of resources, such as use. However, the cork sheet manufactured by the above method requires a long time for molding for curing of the adhesive,
Further, the tensile strength of the sliced sheet is weak, and there is a problem that the sheet is easily damaged at the stage of secondary processing or the like. Furthermore, the surface of the sliced cork sheet is easily soiled, and it is necessary to form a protective coating by coating with a paint or laminating a thermoplastic resin film, but the price of the sheet becomes expensive, including performance. It was hardly satisfactory.

[0004]

A polyolefin-based resin composition containing cork powder, which has excellent physical properties and stain resistance and is inexpensive to be used for architectural members such as floor materials and wall materials.
And the provision of molded articles using the same.

[0005]

The gist of the present invention is to provide a polyolefin resin having a flexural modulus of 2,000 to 10,000 kgf / cm ² and a cork powder having an average particle diameter of 200 to 5000 μm per 100 parts by weight of the resin. It is present in the polyolefin resin composition containing cork powder containing up to 150 parts by weight.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyolefin resin used in the composition of the present invention has a flexural modulus of 2,000 to 10,000 kgf / cm ² . As the flexural modulus, a value measured according to JIS K-7203 is used.

[0007] If the flexural modulus is less than 2000 kgf / cm ² , the rigidity of the molded product is insufficient, and particularly in the use of building materials, it often cannot be used. On the other hand, when the flexural modulus exceeds 10,000 kgf / cm ² , the tendency of the impact strength of the molded article to decrease becomes remarkable, which is not preferable. Flexural modulus is 3000-8000kgf / c
More preferably, it is in the range of m ² .

The above-mentioned polyolefin resins include homopolymers (homopolymers) such as polyethylene and polypropylene, copolymers (copolymers) containing ethylene or propylene as a main component, or the above homopolymers and other polymers. And the like (polymer blend) can be exemplified.
Among them, a polypropylene resin which is a polymer mainly composed of propylene is preferable.

As the polypropylene resin, in addition to the above-mentioned polypropylene, propylene and ethylene or other α
A random copolymer or a block copolymer with an olefin, or a propylene graft polymer having a polyolefin copolymer as a trunk polymer. As the α-olefin copolymerizable with propylene,
Those having 4 to 12 carbon atoms are preferred.
Butene, 1-pentene, 1-hexene, 1-heptene,
Examples thereof include 1-octene, 4-methyl-1-pentene, 1-decene, and the like, and one or a mixture of two or more thereof is used. The mixing ratio of the α-olefin is preferably 5 to 40% by weight based on propylene.

[0010] Examples of the polyolefin copolymer for the backbone polymer of the graft copolymer with propylene include ethylene-propylene rubber, ethylene-butene rubber, and ethylene-propylene-diene rubber. Examples of the polymer which can be mixed with the homopolymer to give a polymer blend include styrene-based thermoplastic elastomers such as styrene-butadiene rubber-based and styrene-isoprene rubber-based. This styrenic thermoplastic elastomer is preferably hydrogenated.

The composition of the present invention comprises the above-mentioned polyolefin resin and 15 to 150 parts by weight of cork powder per 100 parts by weight of the resin. Cork powder having an average particle diameter of 200 to 5000 μm, preferably 300 to
The one of 3000 μm is used. When the average particle size of the cork powder exceeds 5000 μm, heat generation due to the frictional resistance of the cork powder increases during molding, and foaming or coloring occurs due to generation of gas due to decomposition of the cork powder. In addition, fine cork powder having an average particle size of less than 200 μm requires time and effort for pulverization, and is liable to be powdered at the time of mixing at the time of producing the composition, and may contaminate the periphery.

The average particle size of the cork powder is expressed as the particle size at the point where the integrated value of the weight of each fraction measured by a JIS sieve is 50% of the whole. Further, as the cork powder, one having an average particle size within the above-mentioned specific range and having 70% by weight or more, preferably 80% by weight or more of the whole cork powder within the above-mentioned range is suitable.

When the amount of the cork powder to be added is less than 15 parts by weight with respect to 100 parts by weight of the polyolefin resin, the molded product cannot be reduced in weight, and the cushioning property cannot be obtained.
Also poor in design. On the other hand, the amount of cork powder added was 15
If the amount exceeds 0 parts by weight, the surface of the molded article becomes insufficient in smoothness, resulting in poor appearance, or the mechanical strength is significantly reduced.

More preferably, the amount of the cork powder to be added is 25 to 100 parts by weight per 100 parts by weight of the polyolefin resin. The moisture contained in the cork powder is not particularly problematic as long as the cork powder does not significantly absorb moisture. For example, when the cork powder has a water content of more than 10% by weight, foaming during molding becomes intense. The above problems are more likely to occur. In such a case, for example, use after reducing the water content in advance with an oven or a hopper dryer, etc., or prior to mixing with the resin, stir while heating only the cork powder in the mixer to be used to perform the drying process. Then, a method of adding a polyolefin-based resin may be used.

The water content of the cork powder is preferably 3% by weight or less. The cork powder used in the present invention is bark obtained from cork oak, and may be obtained by pulverizing this bark. The bark may include an inner skin and an outer skin in addition to the cork layer. Further, a cork sheet or a cork formed in a block shape may be crushed and recycled as cork particles.

The cork powder-containing polyolefin-based resin composition of the present invention contains a stabilizer, an inorganic filler, a lubricant, a surfactant, an anti-adhesive, a pigment, in addition to the above components, as long as the object of the present invention is not impaired. An antibacterial agent or the like may be added. The cork powder-containing resin composition can be obtained, for example, by kneading a pellet of polyolefin resin and a predetermined amount of the specific cork powder with a Banbury mixer.

Further, the composition thus obtained is
It can be formed into a sheet by a heating roll or a calender roll. Alternatively, the above resin and cork powder may be mixed and pelletized using a twin-screw extruder kneader equipped with a hot-cut device, and then molded using an extruder equipped with a T-die. The molding temperature is preferably in the range of 150 to 200 ° C.
More preferably, it is in the range of 80 ° C.

The thickness of the sheet thus formed is preferably in the range of 0.5 to 10 mm. When the thickness is less than 0.5 mm, the sheet is likely to break during molding. On the other hand, when the thickness exceeds 10 mm, the molding speed is reduced, the productivity of the sheet is significantly reduced, and In this case, the processability also tends to deteriorate. A more preferred sheet thickness is 1 to 5 mm.

The sheet-like cork powder-containing polyolefin-based resin molded article obtained as described above can be used as it is as a wall covering for interiors, or can be used as a wood-based material such as plywood and an adhesive layer. May be used after being laminated.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. <Evaluation of flexural modulus of polyolefin resin> JIS
It was measured according to K-7203. <Evaluation of Sheet> (1) Formability: As shown in the following examples, when a test sheet was prepared using an extruder, ease of forming was evaluated.
The evaluation criteria are as follows.

・ ・ ・: A sheet having a good appearance was produced without any problem. Δ: A sheet could be prepared, but the appearance was inferior. X: The sheet could not be formed. (2) Cracking resistance due to nailing: A test sheet of 3 cm square was prepared and placed in a constant temperature room at 23 ° C. on a plywood plate having a thickness of 15 mm, with a length of 50 mm and a body diameter of 2.75 mm. The occurrence of cracks in the sheet when nails were driven in from the center of the sheet was visually evaluated. The evaluation criteria are as follows.

・ ・ ・: Nail was able to be driven into the sheet without cracking in the nail hole portion. ・ ・ ・: Crack was generated in the nail hole portion. X: The sheet was broken when the nail was driven. (3) Cushioning property: A test piece was placed on a plywood having a thickness of 17 mm placed on the floor, and J was measured at a distance of 80 cm from the upper surface.
A large-sized golf ball specified in ISS 7005 is allowed to fall freely, and the height (from the test piece) of the rebounding ball at the maximum arrival at that time is measured. I read it visually. At this time, the value at the bottom of the ball was read. This measurement was performed ten times, and the average value of eight values excluding the lowest value and the highest value was obtained. In addition, the obtained value (cm)
The smaller the value, the better the cushioning properties (shock absorption properties).

[0023]

[Table 1] Test conditions Test piece: two test sheets each measuring 30 cm long x 20 cm wide x 0.2 cm thick Drop height: 80 cm Measurement temperature: 23 ° C (4) Sheet properties: Tensile fracture of test sheet Strength,
Elongation was measured according to JIS K-7127. (5) Contamination: Measured according to JIS A-5707. <Example 1> 80 parts by weight of a polypropylene resin (FY4 manufactured by Mitsubishi Chemical Corporation), 20 parts by weight of a styrene-based thermoplastic elastomer (Dynalon 1320P manufactured by Nippon Synthetic Rubber Co., Ltd.), and the average particle diameter and addition shown in the table An amount of cork powder was kneaded with a Banbury mixer, a sheet was formed with a roll, and a pellet was formed with a pelletizer. The obtained pellets were formed into a sheet at a temperature of 195 ° C., a sheet thickness of 2 mm, and a take-up speed of 0.5 m / min using a 65 mmφT die forming machine manufactured by Mitsubishi Heavy Industries, Ltd. This sheet was measured for sheet performance such as moldability and cracking resistance due to nailing.

Separately, a resin mixture having the same composition except that it did not contain cork powder was formed into a sheet under the same conditions, and the flexural modulus of the resin used was measured. The results are summarized in (Table). Example 2 A sheet was prepared and evaluated in the same manner as in Example 1 except that the composition ratio of the resin mixture was changed as shown in (Table). The results are shown in (Table). Comparative Example 1 A sheet was prepared and evaluated in the same manner as in Example 1 except that FY4 manufactured by Mitsubishi Chemical Corporation was used alone as the polyolefin resin. The results are shown in (Table). <Comparative Examples 2 and 3> Preparation of a sheet in the same manner as in Example 1 except that the average particle size (Comparative Example 2) or the amount of addition (Comparative Example 3) of the cork powder was changed as shown in Table. An evaluation was performed. The results are shown in (Table). Comparative Example 4 A commercially available cork sheet (2 mm thick) was evaluated.

[0025]

According to the present invention, the polyolefin resin composition having a specific flexural modulus and a specific amount of a cork powder having a specific average particle diameter and a cork powder-containing polyolefin resin composition have good moldability into sheets and the like. Good, excellent in tensile strength and impact resistance, and also excellent in stain resistance. In addition, since it is easy to treat and recycle as waste, it is particularly suitable as an interior building material.

[0026]

[Table 2]

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Miyuki Yamada 2 Oike, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi Pref.

Claims (3)

[Claims] 1. A flexural modulus of 2000 to 10000 kg
f / cm ² polyolefin resin and the resin 100
A cork powder-containing polyolefin resin composition containing 15 to 150 parts by weight of cork powder having an average particle size of 200 to 5000 μm per part by weight. 2. The cork powder-containing polyolefin resin composition according to claim 1, wherein the polyolefin resin is a polypropylene resin. 3. The composition according to claim 1 or 2, wherein
A cork powder-containing resin molded product formed into a sheet having a thickness of 10 to 10 mm.