JPH0959424A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which shows low volatility and low smoking property during molding such as injection molding, extrusion molding, compression molding or blow molding, gives a cured product having a woody texture and good processability such as releasability from concrete, nailing and sawing and has excellent quality. SOLUTION: This composition comprises a thermoplastic resin (e.g. polypropylene), an organic filler (e.g. rice hull powder) and a basic filler (e.g. magnesium oxide). The organic filler should be used in an amount of 5-80 pts.wt., per 100 pts.wt. total of the thermoplastic resin and the organic filler, and the basic filler should be used in an amount of 5-80 pts.wt. per 100 pts.wt. basic filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a thermoplastic resin, an organic filler and a basic filler, and more specifically, it can be used for injection molding, extrusion molding, compression molding, blow molding and the like at a low temperature. A resin composition that exhibits volatility, low smoke generation, and has a woody feel, and has good workability such as peelability with concrete, nailing, sawing, etc., especially when used as a formwork material for concrete. Is.

[0002]

2. Description of the Related Art Conventionally, when concrete is to be hardened, a mold is assembled with wooden panels, concrete is poured into the mold to harden it, and then it is removed after the completion. In such a conventional form made of wooden panels, concrete is easily adhered, it takes labor to remove the concrete, and it is often damaged due to that, and the number of times of repeated use is small. Besides, the wooden ones were heavy and expensive. Further, resin molds have been put on the market in order to solve these drawbacks, but they have drawbacks such as much poorer moldability / workability such as nailing and sawing compared with wooden panels.

In order to solve these drawbacks, it is known to mix a polyolefin resin with an organic filler such as wood powder and obtain a molded product such as a concrete form by compression molding, but it is still known. Not enough.

[0004] In recent years, regarding the technology of using the above organic filler, in addition to the soaring resin price, global environment protection, resource saving,
From the viewpoints of resource utilization and pollution prevention, more and more attention is being paid.

Organic fillers are generally cheaper than other fillers for resins, and molded products obtained by blending the fillers show so-called low pollution such as easy incineration and the like. Material,
Especially, it has suitable conditions as an extender. In addition to the appearance factors such as wood texture, resin products containing organic fillers such as those mentioned above are lighter in weight, rigidity, dimensional stability, machinability, nailing and sawing compared to general resin products. Processability such as pulling and vibration damping, etc.
It has excellent weather resistance and peelability from concrete.
Since it exhibits characteristic properties, it can be said that establishment of a method for preparing an organic filler, a compounding technique, a molding technique and the like is a very important industrial problem from this point as well.

[0006]

However, in actually blending the organic filler with the thermoplastic resin and carrying out the above-mentioned thermoforming such as injection molding and extrusion molding, some difficulties are encountered. It's not always easy.
That is, since the organic filler usually contains about 7% by weight or more of water in some cases and is thermally unstable, a large amount of water or decomposition occurs at a relatively low temperature, for example, near the molding temperature. It shows a phenomenon usually called "burning" such as product release, smoke generation, etc., which causes poor appearance of resin molding (generation of silver streak) and internal defects, and physical properties such as impact strength and bending strength. It causes a large decrease and significantly reduces the product value.

In addition, the problem of odor during molding and the problem of odor generated from the molded product are added, and the establishment and practical application of the technique of using the organic filler has not progressed more than expected.

[0008]

In view of the present circumstances as described above, the inventor of the present invention has conducted earnest research to establish a technique for using an organic filler. As a result, the thermoplastic resin,
By blending a basic filler in addition to the organic filler, the intended resin composition can be obtained, and the basic filler is also effective for improving odor and appearance. The present invention has been found and the present invention has been completed.

That is, the present invention comprises a thermoplastic resin, an organic filler, and a basic filler, and the proportion of the organic filler in 100 parts by weight of the thermoplastic resin and the organic filler is 100% by weight. 5 to 80 parts by weight, and the basic filler is 5 to 80 parts by weight with respect to 100 parts by weight of the organic filler, which is a resin composition for concrete formwork.

As the thermoplastic resin used in the present invention, known resins can be used without any limitation. For example, polyolefin, polyamide, polycarbonate,
Polyether, polyester, polyvinyl chloride, ABS
Various thermoplastic resins such as Especially, it is preferable to use polyolefin, especially propylene resin. Here, the propylene-based resin is a general term including a homopolymer of propylene and a copolymer of propylene and another α-olefin such as ethylene and butene. The propylene resins currently on the market have a melt flow rate of 0.1 to 150 g / 10 minutes, but in the present invention, these propylene resins can be used without particular limitation.

Further, by using a modified polyolefin resin in combination as the thermoplastic resin, the adhesiveness between the organic filler and the thermoplastic resin can be enhanced and physical properties such as impact resistance can be improved. Modified polyolefin resin is
It is a reaction product of a polyolefin resin and a polymerizable carboxylic acid compound, and is generally a graft copolymer. The above-mentioned polymerizable carboxylic acid compound is a general term for a carboxylic acid having an ethylenically unsaturated group and a carboxylic acid anhydride. Specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride and the like are preferably used. A modified polyolefin resin in which such a polymerizable carboxylic acid compound is bound in the modified polyolefin resin in an amount of 0.01 to 5% by weight, preferably 0.05 to 3% by weight is suitably used in the present invention. Such a modified polyolefin resin preferably accounts for 2 to 20% by weight of the thermoplastic resin.

The shape of the thermoplastic resin is powdery, granular,
Pellets and the like can be used without particular limitation, but in general, the average particle size is 3 from the viewpoint of uniform dispersibility and high packing of the filler.
The granular thermoplastic resin having a size of 00 to 800 μm is most preferable.

Next, the organic filler used in the present invention is preferably rice husk powder, bamboo powder and wood powder obtained by crushing, but not limited to them, soybean meal, wheat husk powder, fruit shell powder,
Organic fillers such as wood pulp, finely crushed newspaper, magazines, waste paper such as corrugated cardboard, etc., that is, organic fillers having a small particle size that does not cause a problem during the molding process can be effectively used. Normally, the average particle size is 1 to 800 μm
It is preferable to use the following fine organic fillers. These organic fillers may be used alone or in combination of two or more.

The amount of the organic filler compounded should be 5 to 80 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the thermoplastic resin. That is, when the compounding amount of the organic filler is less than 5 parts by weight, the effect of improving the physical properties of the molded product is not observed, while when it exceeds 80 parts by weight, the resin becomes hard and the moldability is significantly deteriorated.

In the present invention, the basic filler can be used without particular limitation as long as it has a function of acid neutralization.
For example, one or more of magnesium oxide, calcium oxide, calcium hydroxide, calcium silicate, zinc oxide, barium oxide and the like can be used without particular limitation. Particularly, magnesium oxide having both water absorption and acid neutralization is effective.

The above-mentioned basic filler can be used in various shapes and sizes regardless of quality, but the average particle size is 0.1 to 100 μm, preferably 1 to 50 μm from the viewpoint of workability and uniform dispersibility. Are preferred.

The amount of the basic filler compounded is 5 to 80 parts by weight, preferably 10 parts by weight, based on 100 parts by weight of the organic filler in order to facilitate the molding and improve the appearance of the molded product.
It is preferably about 40 parts by weight. If the amount is less than 5 parts by weight, the acidic liquid from the organic filler cannot be fully digested, which may result in poor appearance of the molded product and mold corrosion.
If the amount exceeds 0 parts by weight, the resin generally becomes hard and the moldability deteriorates.

In the resin composition for concrete formwork of the present invention, the above-mentioned three components can sufficiently achieve the object, but by further adding an organic peroxide,
Superior physical properties can be expected. That is, according to the organic peroxide, it is possible to improve the fluidity which is reduced by filling the organic filler.

The above-mentioned organic peroxide is not particularly limited, and known ones can be used. Generally, hydroperoxides, dialkyl peroxides, diacyl peroxides, ketone peroxides, alkyl peresters, and peroxides are used. The oxydicarbonates and the like are used alone or in combination of two or more. The amount of the organic peroxide used is 0. 1 with respect to 100 parts by weight of the composite resin composition of the present invention.
It is preferably in the range of 005 to 0.1 parts by weight.

The resin composition of the present invention comprises, in addition to the above components,
Known additives can be added as necessary within a range that does not significantly impair the effects of the present invention. For example, foaming agent, lubricant, glass fiber, potassium titanate, wollastonite, magnesium oxysulfate, talc,
Inorganic fillers such as calcium carbonate and mica, antioxidants,
Auxiliary additives such as colorants, flame retardants, antistatic agents, ultraviolet absorbers and plasticizers can be added.

The mixing of the above-mentioned respective components in the present invention is not particularly limited, and a known mixing device can be adopted as it is. For example, a known mixer such as a high speed mixer, a tumbler, or a ribbon mixer may be used at a mixing ratio according to the purpose. In addition, the order of mixing and adding the respective components in the above mixing is not particularly limited, and they may be mixed simultaneously or appropriately sequentially if necessary.

For the resin composition of the present invention, the pellets prepared by pelletizing the above raw material mixture directly or by using an extruder are introduced into a molding machine such as an extrusion molding machine, an injection molding machine, a compression molding machine or a blow molding machine. By this, various shapes can be obtained.

[0023]

INDUSTRIAL APPLICABILITY The resin composition of the present invention greatly improves physical properties such as mechanical strength, particularly tensile strength and bending strength, as compared with a molded product obtained from a resin composition containing no basic filler. . In addition, since the generation of gas during molding is suppressed, there is no odor, and the moldability and the appearance of the molded product are extremely good.

In particular, when it is molded into a concrete form, it has excellent peelability from concrete and workability such as nailing and sawing, and exhibits excellent quality in such applications.

Furthermore, when molding is carried out using the resin composition of the present invention, it is possible to prevent corrosion of a molding machine, a mold or the like.

Therefore, it is not necessary to manufacture a molding machine or a mold with a special rope having high corrosion resistance, or to perform anticorrosion plating. The present invention also has such an effect.

[0027]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the raw material in an Example is as follows.

(1) Thermoplastic resin Propylene-ethylene block copolymer having a melt flow rate of 23 g / 10 min (trade name: Tokuyama Polypro PN6)
70, average particle size 570 μm) were used.

(2) Organic filler-rice husk (Sumiselco A type 1 manufactured by Sumitomo Seika Chemicals Ltd.)
00 mesh all products ・ Bamboo powder (Okayama Jonan Denki Co., Ltd. Moso bamboo powder Average particle size 27μ
m) -Wood flour (Ohbayashi Kogyo cellulosin 100M 100 mesh, all products) was used.

(3) Basic filler-Magnesium oxide (manufactured by Ube Chemical Co., Ltd., active magnesium oxide powder U-180-P, average particle size 2.8 μm)
m) ・ Calcium oxide (Bell manufactured by Shiraishi Calcium Co., Ltd.)
-C. M. L. (P) Average particle size 4.0 μm ・ Calcium carbonate (manufactured by Shiraishi Industry Co., Ltd., Whiten P-
30 average particle size 1.75 μm) Calcium hydroxide (Wako Pure Chemical Industries, Ltd. reagent average particle size 5.0 μm) was used.

(4) Modified polypropylene A maleic anhydride modified polypropylene resin (Tokuyama Polypro AD89G, manufactured by Tokuyama Corporation) was used, which has a melt flow rate of 60 g / 10 min.

(5) Organic peroxide 1,3-bis (tert-butylperoxyisopropyl) benzene was used.

The results of the examples were measured and evaluated by the following methods.

(A) Number of shots in which rust was generated Using an injection molding machine (13 oz, manufactured by Japan Steel Works), the resin composition was molded at a molding temperature of 200 ° C. for a molding time of 18 seconds to a wall thickness of 3
A plate-shaped product having a size of mm, a length of 127 mm, and a width of 127 mm was formed. The number of shots in which rust was generated on the die surface and the protruding pins was visually determined.

(B) Appearance of Molded Product In measuring the number of shots in which rust was generated, the appearance of the molded plate-like material was visually judged and evaluated according to the following criteria.

[0036]

[Table 1]

(C) Odor of molded product In measuring the number of shots of rust, the presence or absence of odor of the molded plate-like product was judged and evaluated according to the following criteria.

[0038]

[Table 2]

(D) Concrete releasability Concrete is cast using a concrete form molded using the resin composition of the present invention, and the concrete releasability after solidification is visually determined, and the following criteria are used. evaluated.

[0040]

[Table 3]

(E) Nailing / sawing workability The nailing properties and sawing workability of concrete formwork molded using the resin composition of the present invention were evaluated according to the following criteria.

[0042]

[Table 4]

(F) Density Measured in accordance with JIS K7112.

(G) Melt flow rate Measured in accordance with JIS K6758 (230 ° C.).

(H) Tensile Strength It was measured according to JIS K7113.

(I) Bending strength It was measured according to JIS K7203.

(H) Hardness (Rockwell R Scale) Measured in accordance with JIS K6758.

(J) Heat distortion temperature It was measured according to JIS K7207 (load 181.3 N / cm ² ).

Example A thermoplastic resin (including modified polypropylene resin), an organic filler, a basic filler, and an organic peroxide were mixed at a mixing ratio shown in the table (all parts by weight), and a high-speed mixer (Kawata Manufacturing Co., Ltd.) was used. SMG-100) manufactured by Ikegami Co., Ltd. for 1 minute, and pelletized in advance using a twin-screw extruder (PCM45) manufactured by Ikegai Tekko Co., Ltd. The pellets were injection-molded to produce a concrete mold.

The results are also shown in Table 5, Table 6, Table 7, Table 8, Table 9 and Table 10.

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

[Table 7]

[0054]

[Table 8]

[0055]

[Table 9]

[0056]

[Table 10]

Claims (1)

[Claims] 1. A thermoplastic resin, an organic filler and a basic filler, wherein the total amount of the thermoplastic resin and the organic filler is 1
The resin composition is characterized in that the proportion of the organic filler in 00 parts by weight is 5 to 80 parts by weight, and the basic filler is 5 to 80 parts by weight with respect to 100 parts by weight of the organic filler. Stuff.