JPH09104801A - Thermoplastic resin composition - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: Thermoplastic having excellent heat resistance and mechanical properties (especially tensile permanent elongation), good color tone and the like, particularly suitable for light-colored products and having a simple manufacturing process. A resin composition is provided. SOLUTION: (1) (A) polypropylene component is 1 to 7
0% by weight and (B) a propylene-ethylene random copolymer component of 30 to 99% by weight, which is a block copolymer, wherein the propylene-ethylene random copolymer component comprises 15 units of ethylene-based monomer units. ~ 80 mol%,
100 parts by weight of a propylene block copolymer having 85 to 20 mol% of propylene-based monomer units and an intrinsic viscosity of 5 dl / g or more, and (2) 5 to 200 parts by weight of a plasticizer represented by a process oil. It is a thermoplastic resin composition consisting of parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel olefinic thermoplastic elastomer. More specifically, the present invention relates to an olefin-based thermoplastic elastomer composition having excellent mechanical properties, a good appearance such as hue, and a simple manufacturing process.

[0002]

2. Description of the Related Art Thermoplastic elastomers are characterized by excellent processability, recyclability and mechanical properties, and have recently expanded their applications mainly in the fields of home appliances and automobiles as an alternative to soft vinyl chloride and vulcanized rubber. I am doing it. Above all, demand for olefin-based thermoplastic elastomers is increasing due to their low specific gravity, heat resistance, and excellent recyclability.

As an olefinic thermoplastic elastomer composition, a composition comprising a crystalline polyolefin component such as polypropylene or polyethylene and a rubber component (EPR) such as an ethylene-propylene copolymer is known.

A method for obtaining this composition is known, for example, by melt-kneading polypropylene and EPR using an extruder.

Another olefinic thermoplastic elastomer composition comprises polypropylene, ethylene-propylene-diene terpolymer (EPDM) and process oil, and the EPDM component is dynamically crosslinked by an organic peroxide. Compositions are known. This composition has excellent heat resistance and rubbery properties, and is widely used in industrial parts such as the automobile field.

[0006]

However, the composition obtained by the method of melt-kneading polypropylene and EPR by using an extruder is not suitable when a large amount of a rubber component is added to obtain sufficient flexibility, and When a rubber component is used alone without compounding a crystalline polyolefin component in order to obtain sufficient flexibility, it is difficult to apply it to, for example, the interior parts of automobiles such as steering wheel skins and side brake grips due to poor heat resistance. Met.

Further, a composition comprising polypropylene, an ethylene-propylene-diene terpolymer (EPDM) and a process oil requires a cross-linking reaction step at the time of production, so that the production step is complicated. Also, due to the cross-linking reaction, a yellowish tint is lost, which makes it difficult to apply when a bright color or transparency is required in applications such as stationery such as clear files, desk mats and mechanical pencils. It was

Therefore, it has been desired to develop a new technique that compensates for the above-mentioned drawbacks of the conventional technique. That is, the object of the present invention is to
It is an object of the present invention to provide a thermoplastic resin composition which has a simple manufacturing process, is excellent in heat resistance and mechanical properties (particularly tensile permanent elongation), has a good color and the like, and is suitable for light-colored products.

[0009]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the present inventors have found that a polypropylene component and a propylene-ethylene copolymer component are contained in a specific ratio in a high molecular weight. A thermoplastic resin composition obtained by melt-kneading a propylene-based block copolymer and a plasticizer,
They have found that they are excellent in heat resistance, mechanical properties, and color tone, and have completed the present invention.

That is, the present invention is a block copolymer comprising (1) 1-70% by weight of (A) polypropylene component and 30-99% by weight of (B) propylene-ethylene random copolymer component, The propylene-ethylene random copolymer component contains 15 monomer units based on ethylene.
~ 80 mol%, 85-85 monomer units based on propylene
A thermoplastic resin composition comprising 20 mol% and 100 parts by weight of a propylene-based block copolymer having an intrinsic viscosity of 5 dl / g or more and (2) a plasticizer of 5 to 200 parts by weight.

The propylene block copolymer used in the present invention (hereinafter simply referred to as "block copolymer") comprises a polypropylene component and a propylene-ethylene random copolymer component. As for the respective component ratios of the polypropylene component and the propylene-ethylene random copolymer component, the polypropylene component is 1 to 7
0% by weight, preferably 3 to 60%, and the propylene-ethylene random copolymer component is 30 to 99% by weight, preferably 40 to 97%.

In the above composition, when the polypropylene component is less than 1% by weight, the heat resistance of the molded article made of the thermoplastic resin composition is lowered. On the other hand, when the polypropylene component exceeds 70% by weight, the flexibility and rubber properties of the molded product are lost, and the composition intended by the present invention cannot be obtained.

Within this range, the polypropylene component is 1
When the content is -30% by weight, the transparency of the obtained thermoplastic composition is good, which is preferable.

Further, in the present invention, the above-mentioned propylene-
The content ratio of each of the ethylene-based monomer unit and the propylene-based monomer unit in the ethylene random copolymer component is 15
To 80 mol%, preferably 18 to 60 mol%, more preferably 20 to 50 mol%, and the propylene-based monomer unit is 85 to 20 mol%, preferably 82 to 40 mol%, more preferably 80. ˜50 mol%.

In the above composition, when the content ratio of ethylene-based monomer units is less than 15 mol%, the flexibility and rubber-like properties of the molded product are insufficient and the object of the present invention cannot be achieved. On the other hand, when the content ratio of the ethylene-based monomer unit exceeds 80 mol%, the heat resistance of the molded product is insufficient, and similarly the object of the present invention cannot be achieved.

The block copolymer used in the present invention includes:
Polypropylene component, any one of propylene-ethylene random copolymer component, or as long as both components do not impair the physical properties of the thermoplastic resin composition, to prevent blocking of the block copolymer, other α such as butene. −
5 olefins per 100 parts by weight of block copolymer
It is preferably contained by copolymerization in the range of not more than parts by weight.

The block copolymer used in the present invention comprises a so-called block copolymer molecular chain in which a polypropylene component and a propylene-ethylene random copolymer component are arranged in one molecular chain, and a polypropylene component and propylene-ethylene. It is considered that the random copolymer components and the individual molecular chains are micro-mixed to an extent that cannot be achieved by mechanical mixing.

In the present invention, another important requirement is that the block copolymer should have an intrinsic viscosity of at least 5 dl / g, preferably at least 6 dl / g as measured in a 135 ° C. tetralin solvent. Is. That is, when the intrinsic viscosity is less than 5 dl / g, the allowable oil expansion amount of the plasticizer decreases, so that bleeding of the plasticizer occurs, contamination of the product, adhesion, etc. are observed, heat resistance, tensile permanent elongation, etc. The mechanical properties of are also impaired, and the object of the present invention cannot be achieved.

Further, if the intrinsic viscosity is too high, melt fracture occurs during high-speed extrusion molding and spoils the appearance of the product. Therefore, when the productivity and the appearance of the product are taken into consideration, 40d
It is preferably 1 / g or less.

The other component of the thermoplastic resin composition of the present invention is a plasticizer.

The plasticizer used in the present invention is an aliphatic hydrocarbon, liquid paraffin, polyethylene wax, mineral oil having a molecular weight of 2000 or less, which is blended for the purpose of improving processability and mechanical properties. Etc. and their derivatives are used.

Among these, there is little pollution and odor,
A paraffinic mineral oil having a good color is preferably used.

The plasticizer used in the present invention is blended in an amount of 5 to 200 parts by weight per 100 parts by weight of the block copolymer.
If the blending amount of the plasticizer is less than 5 parts by weight, the flexibility and rubber-like properties of the thermoplastic composition obtained are not sufficient, and 20
If it exceeds 0 part by weight, a large amount of plasticizer bleeding occurs on the surface of the molded article of the obtained thermoplastic composition, and the appearance and touch are extremely deteriorated.

The thermoplastic resin composition of the present invention shows almost no bleeding of the plasticizer and has a good color tone. For example, with regard to colors, the yellowness degree obtained by a color computer is -8 to +1. Furthermore, it has excellent rubber properties,
For example, if the tensile elongation is less than A hardness 60, 10%
20% or less when the A hardness is 60 or more and less than 80,
When the A hardness is 80 or more and less than 90, it is 30% or less.
Furthermore, it is also excellent in heat resistance. For example, when the Vicat softening point (load 2.5N) is less than A hardness 60, 70 ° C or higher, A
When the hardness is 60 or more and less than 80, 90 ° C. or more, the A hardness is 8
At 0 or more and less than 90, the temperature is 100 ° C. or more.

The method for producing the thermoplastic resin composition of the present invention may be any method. Generally, the block copolymer and the plasticizer are mixed in a specific ratio and melt-kneaded. As a kneading device, a conventionally known roll, Banbury mixer, twin-screw extruder or the like is used. Kneading temperature is 1
The temperature may be 70 ° C to 280 ° C, preferably 180 ° C to 250 ° C. The kneading time is 10 seconds to 30 minutes, preferably 1 minute to 10 minutes. Further, the melt-kneading is preferably carried out under a stream of an inert gas such as nitrogen gas in view of suppression of decrease in molecular weight and color tone.

The thermoplastic resin composition of the present invention contains 20 parts by weight of a crystalline polyolefin such as polypropylene or polyethylene for the purpose of improving the fluidity of the resulting thermoplastic resin composition within a range that does not significantly impair the properties thereof. It can be blended in a ratio of less than%.

Further, the thermoplastic resin composition of the present invention comprises
Fillers that have been conventionally used, such as calcium carbonate, whisker carbonate,
Calcium silicate, talc, silica, carbon fiber, graphite, glass fiber, glass sphere, glass flake,
Shirasu balloon, hydrotalcite, clay, alumina, molybdenum disulfide, barium sulfate, mica, diatomaceous earth, aluminum sulfate, calcium sulfate, basic magnesium sulfate, potassium titanate, wollastonite, sepiolite, zonotolite, asbestos, etc., or Coloring agents such as carbon black, titanium oxide, zinc white, red iron oxide, ultramarine blue, dark blue, azo pigments, nitroso pigments, lake pigments, phthalocyanine pigments, quinacridone pigments, or a combination of multiple types of these fillers and pigments. You can do it.

In the present invention, a conventional antioxidant or weathering agent such as a phenol-based, sulfite-based, phenylalkane-based, phosphite-based, or amine-based stabilizer, or a plurality of these types of antioxidants is used. Antioxidants and weathering agents can be combined and compounded. Especially,
Tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl)
Phosphite-based processing stabilizers such as 4,4′-biphenylene diphosphite and distearyl pentaerythritol diphosphite, or by combining them in appropriate amounts, the effect of suppressing a decrease in the molecular weight of the block copolymer can be obtained. Is preferred.

Further, in the thermoplastic resin composition of the present invention, oleic acid amide, N-stearyl erucic acid amide, erucic acid amide, elaidic acid amide and lauric acid, which have been conventionally used, are contained in the thermoplastic resin composition so long as the characteristics thereof are not significantly impaired. Acid fatty acid amides, valmitic acid amides, stearic acid amides, methylenebisstearic acid amides, methylenebisoleic acid amides, ethylene bisstearic acid amides, saturated fatty acid amides such as ethylenebisoleic acid amides, unsaturated fatty acid amides, bis fatty acid amides, etc. The slipperiness of the surface of the molded product can be imparted by adding a lubricant or a combination of plural kinds of lubricants.

Further, in the thermoplastic resin composition of the present invention, a cationic, anionic, nonionic or amphoteric antistatic agent, which has been conventionally used, or a plurality of antistatic agents, which are conventionally used, may be used as long as the characteristics are not significantly impaired. Antistatic agents of different types can be combined and compounded. In particular, nonionic antistatic agents such as polyoxyethylene alkylamines, polyoxyethylene alkylamides, fatty acid esters thereof, and fatty acid esters of glycerin are preferred.

The thermoplastic resin composition of the present invention also comprises
A compounding agent that can be usually compounded with a polyolefin, such as a crystallization nucleating agent such as an aromatic carboxylic acid metal salt, a sorbitol derivative, an organic phosphate and talc, or a chlorine scavenger such as a higher fatty acid metal salt, is used in the present invention. Can be blended within a range that does not impair the mechanical properties of.

These additives can be blended at the stage of producing the thermoplastic resin composition of the present invention or by dry blending with the thermoplastic resin composition of the present invention.

The thermoplastic resin composition of the present invention can be molded into various shaped articles by any of the conventionally used molding methods such as injection molding, extrusion molding, compression molding, calender molding and compression molding. be able to.

[0034]

INDUSTRIAL APPLICABILITY The thermoplastic resin composition of the present invention has a simple manufacturing process, heat resistance and mechanical properties (especially tensile permanent elongation).
Since it is excellent in color tone and the like, when it is made into a product, it is possible to obtain a product which has a rubber-like touch and has a bright color and a good appearance.

Applications of the thermoplastic resin composition according to the present invention include automobile exterior parts (side moldings, mudguards, etc.), automobile interior parts (instrument panel skins, door trim skins, steering wheel skins, armrest skins, pedal skins such as accelerators, footrests). , Side brake grips, switch buttons, etc., household electric appliances parts (refrigerator packing, jar pots and rice cookers, PC key tops, hot carpets, switch buttons, etc.), construction materials (waterproof sheets, industrial waste treatment plants) Sheets, etc., medical supplies (supporters, tapes for taping, bandages, etc.), stationery (clear files, desk mats, etc.)
It can be used in a wide range of fields such as mechanical pencil slip prevention, chisel grip etc.), miscellaneous goods (sucker, bath chair slip prevention, coaster, water bottle grip, packing for underwater glasses, carpet etc.) and resin modification.

[0036]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The measuring method used in the following examples will be described.

1) Method for measuring the respective proportions of ethylene-based monomer units and propylene-based monomer units in the propylene-ethylene (PE) random copolymer component and measurement of the polybutene (PB) component proportion. Method It calculated using the chart of a C-NMR spectrum. That is, the respective proportions of the monomer units based on ethylene and the monomer units based on propylene in the propylene-ethylene random copolymer component are first determined by the polymer (Po
Lymer) Vol. 29 (1988), page 1848, and the attribution of peaks was determined. Next is Macromolecules
The respective ratios of the monomer units based on ethylene and the monomer units based on propylene were calculated with reference to the method described in Volume 10 (1977), page 773.

Next, the weight and ratio of the polybutene component were calculated from the integrated intensity ratio of the peak attributable to methyl carbon in the monomer unit and the peak attributable to methyl carbon in the polybutene component based on propylene.

2) Intrinsic viscosity Measured in tetralin at 135 ° C.

3) Vicat softening temperature Measured according to JIS K7206. However, the test load applied to the test piece was 2.5N.

4) Tensile Permanent Tensile Elongation Measured in accordance with JIS K6262 (100% elongation, holding for 10 minutes, contraction, and measurement after 10 minutes). A No. 1 type test piece was prepared by injection molding and used as a test piece.

5) Color The degree of yellowness is defined by JIS K7105. An SM color computer model SM-3 manufactured by Suga Test Instruments Co., Ltd. was used for measuring and calculating the yellowness. Vertical 78 mm x Horizontal 47 m
A color plate of m × thickness 3 mm was prepared by injection molding and used as a test piece. It should be noted that the more positive the degree of yellowness, the stronger the yellow tint and the worse the color tone.

6) Bleed A No. 1 type test piece specified in JIS K6262 was prepared by injection molding and left in an oven at 60 ° C. for 1 hour. Then, the bleed of the plasticizer on the surface of the test piece was visually observed as follows. Three-stage evaluation was performed.

◯: Almost no bleeding was observed Δ: Some bleeding was observed ×: Severe bleeding was observed.

7) A hardness Measured according to JIS K6253.

In Comparative Example 5 and Comparative Example 8, block copolymers preliminarily degraded with an organic peroxide were used.

As the plasticizer, Diana Process Oil PW-380 molecular weight 746 manufactured by Idemitsu Kosan Co., Ltd. was used.

Example 1 (Preliminary Polymerization) A glass autoclave reactor having an internal volume of 1 liter equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Reactor temperature 2
Keeping at 0 ° C., 0.18 mmol of diethylene glycol dimethyl ether, 22.7 mmol of ethyl iodide, 18.5 mmol of diethyl aluminum chloride, and titanium trichloride (“TOS-1” manufactured by Marubeni Solvay Chemical Co., Ltd.).
7 "), 22.7 mmol was added, and then propylene was continuously introduced into the reactor for 30 minutes such that the amount of propylene was 3 g per 1 g of titanium trichloride. The temperature during this period was kept at 20 ° C. After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed four times with purified heptane. As a result of the analysis, 2.9 g of propylene was polymerized per 1 g of titanium trichloride.

(Main Polymerization) Polymerization of Propylene and Copolymerization of Propylene Ethylene To a 2 liter autoclave subjected to nitrogen substitution, 1 liter of liquid propylene and 0.70 mmol of diethylaluminum chloride were added, and the internal temperature of the autoclave was adjusted to 70 ° C. The temperature was raised. 0.087 mmol of a titanium-containing polypropylene polymer was added as titanium trichloride, and propylene was polymerized at 55 ° C. for 30 minutes. During this time, hydrogen was not used. Then, the internal temperature of the autoclave is rapidly increased to 55
0.50 mmol of ethylaluminum sesquiethoxide and 0.01
A 4 mmol mixed solution was added, ethylene was supplied so that the ethylene gas concentration in the gas phase was 15 mol%, and propylene and ethylene were copolymerized at 55 ° C. for 120 minutes. During this period, the ethylene gas concentration was kept at 15 mol% while being confirmed by a gas chromatograph. During this time, hydrogen was not used. After the polymerization was completed, unreacted monomers were purged to obtain a polymer. The yield was 120 g, and the polymerization ratio of all polymers was 6000 g-polymer / g-titanium trichloride.

The obtained block copolymer had a polypropylene component content of 10% by weight, a propylene-ethylene random copolymer component content of 90% by weight, and an ethylene-based monomer unit in the propylene-ethylene random copolymer component content. Three
It had an intrinsic viscosity of 16.5 dl / g measured in tetralin at 135 ° C. at 9 mol%.

The block copolymer 100 thus obtained was obtained.
After adding 100 parts by weight of a plasticizer (manufactured by Idemitsu Kosan Co., Ltd., Diana Process Oil PW380, molecular weight 746) per part by weight, a twin-screw high-kneading extruder was used to perform melt-kneading at 200 ° C. under a nitrogen gas stream to obtain a thermoplastic resin. A composition was obtained. The evaluation results of the thermoplastic resin composition are shown in Table 1.

Examples 2 to 7 The procedure of Example 1 was repeated except that the type of the block copolymer used was changed, and the properties of the block copolymer used and the blending and evaluation results of the thermoplastic resin composition were evaluated. The results are shown in Table 1.

Comparative Examples 1 to 5 The procedure of Example 1 was repeated, except that the type of the block copolymer used was changed, and the properties of the block copolymer used and the blending and evaluation results of the thermoplastic resin composition were shown. The results are shown in Table 1.

Example 8 The procedure of Example 1 was repeated except that the amount of the plasticizer added was changed to 8 parts by weight, and the properties of the block copolymer used and the blending and evaluation results of the thermoplastic resin composition are shown in Table 1. It was shown to.

Example 9 The procedure of Example 1 was repeated except that the type of the block copolymer used was changed and the amount of the plasticizer added was 180 parts by weight. The composition of the resin composition and the evaluation results are shown in Table 1.

Comparative Example 6 The procedure of Example 1 was repeated except that the amount of the plasticizer added was changed to 3 parts by weight, and the properties of the block copolymer used and the blending and evaluation results of the thermoplastic resin composition are shown in Table 1. It was shown to.

Comparative Example 7 Example 9 was repeated except that the amount of the plasticizer added was 210 parts by weight.
Table 1 shows the properties of the block copolymer used, the formulation of the thermoplastic resin composition, and the evaluation results.

Comparative Example 8 The procedure of Comparative Example 5 was repeated except that the amount of the plasticizer added was changed to 3 parts by weight, and the properties of the block copolymer used and the blending and evaluation results of the thermoplastic resin composition are shown in Table 1. It was shown to.

Comparative Example 9 Commercially available ethylene-propylene random copolymer rubber (E
The evaluation results of (PR) are shown in Table 1.

Comparative Example 10 Table 1 shows the evaluation results of an olefinic thermoplastic elastomer comprising a commercially available polypropylene, an ethylene-propylene-diene terpolymer (EPDM) and a process oil.

[0062]

[Table 1]

Claims (1)

[Claims] 1. The (1) (A) polypropylene component is 1 to
70% by weight and (B) a propylene-ethylene random copolymer component of 30 to 99% by weight, which is a block copolymer, wherein the propylene-ethylene random copolymer component has 15 ethylene-based monomer units. ~ 80 mol%, 85 to 20 mol% of propylene-based monomer units
And a thermoplastic resin composition comprising 100 parts by weight of a propylene-based block copolymer having an intrinsic viscosity of 5 dl / g or more and (2) a plasticizer of 5 to 200 parts by weight.