JPH06192488A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition which is excellent in processability and gives a molding having well-balanced rigidity, heat resistance, etc. CONSTITUTION:The composition consists of 100 pts.wt. polyolefin, 0.1-20 pts.wt. polymethylpentene resin and 0-400 pts.wt. inorganic filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin composition, and more specifically, it is composed of a polyolefin, a polymethylpentene resin and an inorganic filler and is excellent in processability and excellent in rigidity, heat resistance and the like. The present invention relates to a polyolefin resin composition that provides a molded product.

[0002]

2. Description of the Related Art Polyolefins are widely used because they are inexpensive and have excellent physical properties. However, for example, in polypropylene, 1) the viscosity and the tension at the time of melting are low, and therefore the vacuum formability of the sheet (hereinafter,
Thermoformability), calender moldability, blow moldability,
Low workability such as foam moldability 2) Low rigidity compared to other polystyrene, polyvinyl chloride, ABS resin, etc.
It has drawbacks such as

[0003] Mechanical mixing of polyethylene and the like is widely used to improve processability, but the improvement effect is insufficient, and therefore a large amount of polyethylene component is required, and the rigidity is further increased. Has caused a decline in. Also,
Although the viscosity and tension at the time of melting have been improved by increasing the molecular weight of polyolefin, it is not preferable because it makes extrusion molding, which is an important processing method of polyolefin, difficult. Originally low rigidity of polyolefin, and addition of an inorganic filler or the like is carried out for the purpose of improving the rigidity reduction due to the addition of polyethylene or the like, but the inorganic filler has a low compatibility with the polyolefin, and therefore due to poor dispersion, It has a drawback that the surface properties of a molded product, for example, an extruded sheet, are significantly reduced. Further, the heat resistance is lower than that of engineering plastics and the like, and improvement thereof is desired. As described above, the fact is that a polyolefin resin that is sufficiently satisfactory in processability, rigidity, heat resistance, etc. has not yet been obtained.

[0004]

DISCLOSURE OF THE INVENTION The present invention aims to obtain a polyolefin resin composition having excellent processability, rigidity and heat resistance by mixing a polymethylpentene resin and an inorganic filler with a polyolefin. It was made.

[0005]

According to the present invention, 100 parts by weight of a polyolefin (A), 0.1 to 20 parts by weight of a polymethylpentene resin (B) and 0 to 4 of an inorganic filler (C) are used.
The content is a polyolefin resin composition consisting of 100 parts by weight.

That is, the inventors of the present invention increase the melt tension at the time of processing the polyolefin by mixing the polymethylpentene resin (B) with the polyolefin (A), and thus the processability, especially thermoformability and calender molding. , Blow moldability,
It was found that the drawdown of the sheet and the parison at the time of melting is improved and the open cell formation of the foam cells is improved in foam moldability and the like, and the present invention has been made based on such findings.

The reason why the drawdown is improved is not clear, but the crystal nuclei of the polymethylpentene resin, which has a high melting point, remains as it is during the melting of a normal polyolefin having a lower melting point and acts as a pseudo-crosslinking point. , It is estimated to prevent drawdown. With respect to thermoformability, calender moldability, blow moldability, foam moldability, etc., it is possible to carry out molding by selecting such an intermediate temperature range. Further, in the extrusion molding, polymethylpentene can also be carried out at a high temperature at which it is melted at the same time, and in particular, it does not hinder the extrusion characteristics such as the discharge amount,
It can be extruded. Rather, by selectively using polymethylpentene having a small melt viscosity, the viscosity at the time of extrusion is lowered and the extrusion characteristics are improved, and further the above-mentioned thermoformability, calender moldability, blow moldability, foam moldability, etc. are further improved. It is possible to

Examples of the polyolefin (A) in the present invention include polypropylene, high density, low density and linear low density polyethylene, poly-1-butene, polyisobutylene, copolymers of ethylene and propylene in all ratios, ethylene. Ethylene with a diene component of 10% (wt%, the same applies below) or less at any ratio of propylene and propylene
Random, block, graft copolymerization of propylene-diene terpolymer, polymethylpentene, ethylene or propylene with vinyl compound such as 50% or less of vinyl acetate, methacrylic acid alkyl ester, acrylic acid alkyl ester and aromatic vinyl. A combination and the like are included, and these are used alone or in combination of two or more kinds. As the polyolefin in the present invention, a propylene-based polyolefin containing 50% or more of propylene, or 100 parts by weight of propylene-based polyolefin containing 50% or more of propylene (parts by weight;
100 parts of the mixture, and further, those having a melt flow index at 230 ° C. of 4 or less have good kneading and dispersibility with a crosslinked rubbery polymer, an inorganic filler and the like, and easily exhibit the effects of the present invention. Is preferred.

The polymethylpentene resin (B) used in the present invention is a polymer of 4-methylpentene-1, which is commercially available from Mitsui Petrochemical Co., Ltd. under the trade name of TPX. Until now, no attempt has been made to use a polymethylpentene resin as a polyolefin processability improver. In particular, no attempt has been made to use it as a drawdown inhibitor during melting.

Typical examples of the inorganic filler (C) in the present invention include heavy calcium carbonate, light calcium carbonate, talc, glass fiber and the like, and these may be used alone or in combination of two or more kinds. Particularly, heavy calcium carbonate, light calcium carbonate, talc and the like are preferable.

The polyolefin resin composition of the present invention is
It is obtained by mixing the polyolefin (A), the polymethylpentene resin (B) and the inorganic filler (C). The mixing ratio of the polymethylpentene resin (B) is 0.1 to 20 with respect to 100 parts of the polyolefin (A).
Parts, the inorganic filler (C) is 0 to 400 parts, preferably the polymethylpentene resin (B) is 0.5 to 10 parts, and the inorganic filler (C) is 0 to 300 parts. When the polymethylpentene resin (B) is less than 0.1 parts, the effect of improving the workability, impact resistance and surface property is insufficient, and when it exceeds 20 parts, the original properties of the polyolefin are lost. Be seen.
Further, when the inorganic filler (C) exceeds 400 parts, the surface property is deteriorated. The method of mixing the polyolefin (A), the polymethylpentene resin (B), and the inorganic filler (C) is not particularly limited, but extrusion kneading, roll kneading, etc. may be used.
Conventional methods well known can be used. It is also possible to perform multi-stage mixing such as mixing the polymethylpentene resin (B), the inorganic filler (C) and a part of the polyolefin (A), and then further adding and mixing the rest of the polyolefin (A). is there. A stabilizer, a lubricant and the like can be added to the polyolefin resin composition of the present invention, if necessary. Also, if necessary, a core-shell type impact modifier conventionally used in polyvinyl chloride resins,
A processability improver and the like can also be used. The resin composition of the present invention obtained as described above is excellent in processability, rigidity, heat resistance and the like.

[0012]

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto. Examples 1 to 3 and Comparative Examples 1 and 2 Polymethylpentene resin "TPX-MX-004 (trade name, manufactured by Mitsui Petrochemical Industry Co., Ltd.)", heavy calcium carbonate surface-treated with fatty acid and having a particle diameter of 1.8 µm Was mixed with polypropylene "Hipol-B-200 (trade name, manufactured by Mitsui Petrochemical Industry Co., Ltd.)" at a mixing ratio shown in Table 1, and a twin screw extruder having a screw diameter of 44 mm and an L / D of 30 was used. The mixture was extruded at 240 ° C. and 100 rpm, kneaded, and pelletized. Various test pieces were obtained by roll-kneading the obtained pellets at 200 ° C. and press-molding. Using the obtained test piece, ASTM-D 790, ASTM-D 64
Bending elasticity test and heat resistance test were carried out according to 8. The drawdown was performed by forming a sheet having a 100 mm square and a thickness of 1.5 mm, fixing the sheet with a clamp having an opening of 76 mm square, and measuring the drawdown of the sheet for 30 minutes in a 190 ° C. oven. The melt flow index was calculated using the above pellets as A
It measured at 230 degreeC according to STM-D1238.
The obtained results are shown in Table 2.

[0013]

[Table 1] Note: PP: polypropylene, trade name: HYPOL-B-20
0. Polymethylpentene resin manufactured by Mitsui Petrochemical Co., Ltd .: trade name: TPX-MX-00
4, manufactured by Mitsui Petrochemical Industry Co., Ltd.

[0014]

[Table 2]

The mixture of the polymethylpentene resin (B) and the inorganic filler (C) in the olefin (A) (Example 1) is a mixture of the olefin (A) and the inorganic filler (C) (comparison). As compared with Example 1), the rigidity and heat resistance are improved, and at the same time, the workability, especially the drawdown of the sheet, is improved. Further, at this time, the melt flow index was rather increased, and the extrudability was not hindered, but rather improved. Also,
It can be seen that the same tendency is observed also in the system in which the inorganic filler (C) does not exist (Example 2, Comparative Example 2).

[0016]

EFFECT OF THE INVENTION The polyolefin resin composition of the present invention can provide a molded article which is excellent in processability and rigidity and heat resistance.

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Claims (5)

[Claims] 1. A polyolefin (A) 100 parts by weight,
0.1 to 20 parts by weight of polymethylpentene resin (B),
A polyolefin resin composition comprising 0 to 400 parts by weight of an inorganic filler (C). 2. The polymethylpentene resin (B) is 0.1
The composition according to claim 1, which is from 10 to 10 parts by weight. 3. The composition according to claim 1, wherein the inorganic filler (C) is calcium carbonate and / or talc. 4. The polyolefin (A) is at least 50.
A propylene-based polyolefin of about 1% by weight.
~ The composition according to 3. 5. The polyolefin (A) is at least 50.
The composition according to claims 1 to 3, which comprises a mixture of 100 parts by weight of a propylene-based polyolefin consisting of propylene in an amount of 0.1% by weight and 0.1 to 100 parts by weight of polyethylene.