JPH1060220A - Thermoplastic resin composition - Google Patents

Abstract

(57) Abstract: (a) Two or more polymer blocks A comprising a vinyl aromatic compound, and 35% of carbon-carbon double bonds based on the conjugated diene compound, comprising a conjugated diene compound 100 parts by weight of a hydrogenated block copolymer having at least one hydrogenated polymer block B and a vinyl aromatic compound content of 5 to 75% by weight, (b) a non-aromatic rubber 30 to 200 parts by weight of a softener for use, (c) 10 to 100 parts by weight of a polyolefin resin, and (d) an average particle diameter of 0.5 to 2 μm, and a sieve residue of 325 mesh of 0.01% by weight or less. A thermoplastic resin composition comprising 30 to 100 parts by weight of inorganic particles having a specific gravity of 3 or more. [Effect] A molded article having excellent mechanical strength, flexibility and heat resistance, good surface gloss, and a specific gravity of 1 or more is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic resin composition having good surface gloss and excellent flexibility.
The present invention also relates to a thermoplastic resin composition that gives a molded article having a large specific gravity.

[0002]

2. Description of the Related Art Conventionally, vulcanized rubber and PVC (polyvinyl chloride) have been used in the fields of industrial goods, sundries, sports goods, and the like, but they have problems such as poor recyclability and environmental pollution. Have a point. Therefore,
Polyolefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and the like have been used as substitutes for these materials. These thermoplastic elastomers are characterized in that they are easy to mold, that they can be recycled, and that a lightweight molded article with a low specific gravity can be obtained. However, a molded article having a specific gravity as large as one or more may be required depending on the application. In such a case, generally, a large amount of an inorganic filler is added to these thermoplastic elastomers for the purpose of adjusting the specific gravity, but the moldability is reduced, and the surface gloss of the obtained molded article is impaired. I will. In addition, when a polyolefin-based thermoplastic elastomer or a polyester-based thermoplastic elastomer is used, it is generally difficult to obtain a molded article having high flexibility.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a specific gravity of 1 unit.
Accordingly, an object of the present invention is to provide a thermoplastic resin composition which gives a molded article having excellent surface gloss and flexibility.

[0004]

According to the present invention, the above object is achieved by (a) comprising at least two polymer blocks A comprising a vinyl aromatic compound and a conjugated diene compound, based on the conjugated diene compound. 35% of carbon-carbon double bonds
100 parts by weight of a hydrogenated block copolymer having at least one hydrogenated polymer block B and a vinyl aromatic compound content of 5 to 75% by weight, (b) a non-aromatic rubber 30 to 200 parts by weight of a softener for use, (c) 10 to 100 parts by weight of a polyolefin resin, and (d) an average particle diameter of 0.5 to 2 μm, and a sieve residue of 325 mesh of 0.01% by weight or less. Is achieved by providing a thermoplastic resin composition comprising 30 to 100 parts by weight of inorganic particles having a specific gravity of 3 or more.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The hydrogenated block copolymer (a) constituting the thermoplastic resin composition of the present invention is a polymer having two or more polymer blocks made of a vinyl aromatic compound in a molecule and comprising a conjugated diene compound A hydrogenated block copolymer obtained by hydrogenating a block copolymer having one or more blocks, wherein at least 35% of carbon-carbon double bonds based on a conjugated diene compound are hydrogenated, and vinyl The content of the aromatic compound is 5 to 75% by weight.

Examples of the vinyl aromatic compound constituting the block copolymer before hydrogenation include styrene, α-methylstyrene, o, m- or p-methylstyrene,
3-dimethylstyrene, vinylnaphthalene, vinylanthracene and the like. Among them, styrene or α-methylstyrene is preferred. The vinyl aromatic compounds may be used alone or in combination of two or more.

The conjugated diene compounds constituting the block copolymer before hydrogenation include, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like can be mentioned. Among these, isoprene, 1,3-
Butadiene or mixtures thereof are preferred. The conjugated diene compounds may be used alone or in combination of two or more.

The content of the vinyl aromatic compound in the hydrogenated block copolymer (a) needs to be 5 to 75% by weight. 5% by weight of vinyl aromatic compound
If it is less than 1, the mechanical strength of the molded article obtained from the thermoplastic resin composition is not sufficient. On the other hand, when the content of the vinyl aromatic compound exceeds 75% by weight, a molded article obtained from the thermoplastic resin composition tends to have problems such as poor flexibility and brittleness. The content of vinyl aromatic compound is 1
It is preferably from 0 to 65% by weight.

In the hydrogenated block copolymer (a), it is necessary that at least 35% of carbon-carbon double bonds based on the conjugated diene compound in the polymer block composed of the conjugated diene compound are hydrogenated. is there. When the hydrogenation rate of the carbon-carbon double bond in the polymer block composed of the conjugated diene compound is less than 35%, the hydrogenated block copolymer (a) deteriorates during the molding process of the thermoplastic resin composition. Moreover, the heat resistance of the obtained molded product is not sufficient. In addition, the hydrogenation rate of the carbon-carbon double bond in the polymer block composed of the conjugated diene compound can be calculated by an iodine value measurement method, an infrared spectrophotometer, nuclear magnetic resonance, or the like.

The molecular weight of the hydrogenated block copolymer (a) is
Although not particularly limited, preferably 50,000 to 1,0
00,000, more preferably 100,000-
300,000.

The bonding mode of the polymer block A and the polymer block B in the hydrogenated block copolymer (a) is as follows:
It may be linear, branched, or any combination thereof. Further, the hydrogenated block copolymer (a)
As long as the spirit of the present invention is not impaired, a carboxyl group, a hydroxyl group, an acid anhydride group,
It may contain a functional group such as an amino group or an epoxy group.

As a method for producing the hydrogenated block copolymer (a), for example, the following known anionic polymerization method can be employed. That is, a vinyl aromatic compound and a conjugated diene compound are sequentially polymerized in an inert organic solvent using an alkyllithium compound or the like as an initiator to form a block copolymer. Next, the obtained block copolymer is hydrogenated in an inert organic solvent in the presence of a hydrogenation catalyst according to a known method to synthesize a hydrogenated block copolymer (a). Here, platinum is used as the hydrogenation catalyst,
Noble metal-based catalysts such as palladium; Raney nickel, organic nickel compounds, organic cobalt compounds, or composite catalysts of these compounds with other organic metal compounds can be used.

As the softener (b) for the non-aromatic rubber constituting the thermoplastic resin composition of the present invention, conventionally known softeners can be used without any particular limitation. For example, paraffin-based process oils and Naphthenic process oil, white oil, mineral oil, ethylene and α-
Examples include olefin oligomers, paraffin wax, and liquid paraffin, and among them, paraffin-based process oil is preferable. The non-aromatic rubber softener (b) may be used alone or in combination of two or more.

The amount of the non-aromatic rubber softener (b) to be used should be 30 to 200 parts by weight per 100 parts by weight of the hydrogenated block copolymer (a).
Preferably it is 80 parts by weight. The amount of the non-aromatic rubber softener (b) used is equal to or less than the hydrogenated block copolymer (a) 10
If the amount is less than 30 parts by weight with respect to 0 parts by weight, the moldability of the thermoplastic resin composition decreases, while the amount of the non-aromatic rubber softener (b) used is less than that of the hydrogenated block. When the amount exceeds 200 parts by weight with respect to 100 parts by weight of the polymer (a), the molded article obtained from the thermoplastic resin composition has insufficient mechanical strength and causes bleeding of the softener. It is not preferable.

[0015] The polyolefin resin (c) constituting the thermoplastic resin composition of the present invention is an α-olefin having 2 to 12 carbon atoms.
Monoolefin is a polymer having a main monomer component, for example, polyethylene, polypropylene, ethylene-propylene random copolymer, ethylene-propylene block copolymer, low-density polyethylene, high-density polyethylene, linear low-density polyethylene Known materials such as ethylene-octene random copolymer, ethylene-vinyl acetate copolymer, poly-4-methylpentene-1, polybutene-1, and ethylene-acrylate copolymer can be used. Among these, a polymer containing ethylene or propylene as a main monomer component is preferable. Specifically, various polypropylenes, various polyethylenes, an ethylene-octene random copolymer, an ethylene-vinyl acetate random copolymer, and an ethylene- ( Examples thereof include an ethylene-based random copolymer such as a (meth) acrylic acid random copolymer and an ethylene-glycidyl methacrylate random copolymer, a propylene-based random copolymer, and a propylene-based block copolymer. These polyolefin-based resins (c) may be used alone or as a mixture of two or more.

The amount of the polyolefin resin (c) used is
10 to 100 parts by weight of the hydrogenated block copolymer (a)
-100 parts by weight, preferably 15-80 parts by weight. If the amount of the polyolefin-based resin (c) is less than 10 parts by weight based on 100 parts by weight of the hydrogenated block copolymer (a), the moldability of the thermoplastic resin composition is inferior. The amount of the base resin (c) used is hydrogenated block copolymer (a) 1
If the amount exceeds 80 parts by weight with respect to 00 parts by weight, the flexibility of the molded article obtained from the thermoplastic resin composition becomes insufficient, which is not preferable.

The inorganic particles (d) constituting the thermoplastic resin composition of the present invention have an average particle diameter of 0.5 to 2 μm and 3
It is necessary that the sieve residue at 25 mesh is 0.01% by weight or less. Average particle size of inorganic particles is 0.5μ
If it is less than m, the dispersion of the inorganic particles becomes poor when preparing the thermoplastic resin composition, and it becomes difficult to prepare a uniform thermoplastic resin composition. On the other hand, when the average particle diameter of the inorganic particles (d) exceeds 2 μm, the surface gloss of a molded article obtained from the thermoplastic resin composition is impaired. The average particle diameter of the inorganic particles (d) is preferably from 0.7 to 1.2 μm. Incidentally, the average particle size in the present invention,
It was measured using a laser diffraction and light diffusion type particle size distribution analyzer.

If the amount of the inorganic particles (d) at 325 mesh exceeds 0.01% by weight, the surface gloss of the molded article obtained from the thermoplastic resin composition is impaired. The sieve residue referred to in the present invention means a ratio of particles remaining on the inorganic particles (d) when the inorganic particles (d) are passed through a sieve having a mesh size of 325 mesh.

The inorganic particles (d) used in the present invention must have a specific gravity of 3 or more. When the specific gravity of the inorganic particles (d) is less than 3, it is necessary to use a large amount of the inorganic particles (d) in order to obtain a molded product having a specific gravity of 1 or more, and the processability of the thermoplastic resin composition is increased. Is undesirably reduced. The specific gravity of the inorganic particles is preferably 4 or more.

Inorganic particles (d) satisfying such conditions
As the material of, for example, barium sulfate, titanium oxide,
Examples thereof include lithopone (white pigment), zinc oxide, and zinc powder. Of these, barium sulfate and zinc oxide are preferable. As the inorganic particles (d), commercially available particles may be used, or particles having a large particle diameter may be appropriately pulverized using a grinder, a milk stick or the like. Also,
One kind of the inorganic particles (d) may be used, or two or more kinds may be used as a mixture.

The amount of the inorganic particles (d) used must be 30 to 100 parts by weight, and preferably 50 to 100 parts by weight, per 100 parts by weight of the hydrogenated block copolymer (a). preferable. When the amount of the inorganic particles (d) used is less than 30 parts by weight based on 100 parts by weight of the hydrogenated block copolymer (a), a molded article having a specific gravity of 1 or more cannot be obtained. If the amount of the inorganic particles (d) exceeds 100 parts by weight with respect to 100 parts by weight of the hydrogenated block copolymer (a), the moldability of the thermoplastic resin composition decreases and the surface gloss is improved. Cannot be obtained.

In the thermoplastic resin composition of the present invention, a filler different from the above-mentioned inorganic particles (d) can be added as needed within a range not to impair the gist of the invention. Such fillers include, for example, calcium carbonate,
Examples include talc, carbon black, silica, clay, magnesium carbonate, glass fiber, carbon fiber and the like.

The thermoplastic resin composition of the present invention may further contain, if necessary, a styrene-based resin such as polystyrene, high-impact polystyrene, ABS, or the like; polyethylene terephthalate, polybutylene terephthalate, etc. Polyester resins; thermoplastic resins such as polyamide resins such as nylon-6, nylon-66 and nylon-12; heat stabilizers; antioxidants;
Light stabilizer, flame retardant, tackifier, antistatic agent, foaming agent,
It is also possible to add a coloring pigment or the like.

As a method for producing the thermoplastic resin composition of the present invention, a conventionally known method is used without any particular limitation. In order to obtain a uniform composition, a single-screw extruder, a twin-screw extruder, It is preferable to use a kneading machine such as a Banbury mixer, a Brabender, an open roll, or a kneader. A homogeneous thermoplastic resin composition can also be obtained by blending each component in advance using a mixer such as a Henschel mixer or a tumbler, and then kneading the mixture using the above-described kneader.

The thermoplastic resin composition of the present invention is, for example,
It can be processed into a molded product using a conventionally known method such as extrusion molding, injection molding, hollow molding, compression molding, and calendar molding.

The thermoplastic resin composition of the present invention provides a molded article having excellent moldability, excellent mechanical strength, flexibility and heat resistance, good surface gloss, and a specific gravity of 1 or more. It has features, various gaskets,
Hose coatings, weather strips, filler panels, wire cable coatings, air intake hoses, refrigerators, washing machines, electric fans, televisions, stereos, speakers and other household electrical appliance parts, and industrial parts such as door panels and front panels Parts; applications such as hoses, tubes, belts, etc .; footwear applications, such as sports shoes, leisure shoes, fashion sandals, etc .; a wide range of other everyday products, leisure products, sports equipment applications, such as tennis rackets and golf club grips; Can be used for applications.

[0027]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In these examples and comparative examples, the hardness, rupture strength, rupture elongation, surface glossiness and specific gravity of a molded product obtained from the thermoplastic resin composition were evaluated by the following method. . (1) Hardness In accordance with the method specified in JIS K6301, the hardness of the sheet was measured using a spring-type A-type hardness meter and used as an index of flexibility. (2) Breaking strength and elongation at break A tumbler-shaped test piece specified in JIS No. 3 is punched out from a sheet having a thickness of 1 mm, and the test piece is used in accordance with JIS.
A tensile test was performed at a tensile speed of 500 mm / min in accordance with K6301, and the breaking strength (kg / cm ² ) and the breaking elongation (%) were measured. (3) Surface glossiness The surface of a sheet having a thickness of 1 mm was visually observed and evaluated according to the following criteria. ：: Good (with gloss, without agglomerates) ×: Poor (without gloss, with agglomerates) (4) A sheet with a specific gravity of 1 mm is cut into a slit with a width of 1 cm,
Using the obtained strip, it was measured by a displacement method according to JIS K6220.

In the following Examples and Comparative Examples, the hydrogenated block copolymer (a), the softener for non-aromatic rubber (b), the polyolefin resin (c), and the inorganic particles (d) were as follows: The following were used respectively. Hydrogenated block copolymer (a) a-1) "Septon 4055" (trade name, Kuraray Co., Ltd.)
[Hydrogenated styrene-isoprene-styrene block copolymer having a styrene content of 30%, hydrogenation ratio: about 100%] Softener for non-aromatic rubber (b) b-1) Paraffin-based process Oil (trade name: Diana Process Oil PW-380, (made by Idemitsu Kosan Co., Ltd.) Polyolefin resin (c) c-1) Polypropylene (trade name: B301H, made by Ube Industries, Ltd.) c-2) Polyethylene ( Trade name: LC604, manufactured by Mitsubishi Chemical Corporation) Inorganic particles (d) d-1) Barium sulfate (specific gravity: 4.3) "B-54" (trade name, manufactured by Sakai Chemical Industry Co., Ltd.) [Average particle diameter 1.2 μm,
D-2) Barium sulfate (specific gravity: 4.3) “300” (trade name, manufactured by Sakai Chemical Industry Co., Ltd.) [average particle diameter: 0.7 μm, 3
The sieve residue at 25 mesh> 0.01% by weight (0.1
Weight% or less)]

Examples 1 to 4 and Comparative Examples 1 to 3 According to the composition shown in Table 1, after premixing each component, kneading was performed at 230 ° C. using a twin screw extruder, and pelletized thermoplastic resin was obtained. A composition was obtained. The obtained pellets were pressed at 230 ° C., 100 kg / cm ² , 5 using a press molding machine.
For 15 minutes, then solidified in a cooling press at 20 ° C., 15 cm (length) × 15 cm (width) × 1 m
m (thickness) was obtained. Using the obtained sheet, various physical properties were measured by the methods described above. The results are shown in Table 1.

[0030]

[Table 1]

[0031]

According to the present invention, mechanical strength, flexibility,
Provided is a thermoplastic resin composition having excellent heat resistance, good surface gloss, and giving a molded article having a specific gravity of 1 or more. The thermoplastic resin composition of the present invention is excellent in moldability and recyclability, and can be used for a wide range of uses such as home electric parts, industrial goods, sports goods, and miscellaneous goods.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yosuke Jigo 36-towada, Kamisu-cho, Kashima-gun, Ibaraki Pref. Kuraray Co., Ltd.

Claims (1)

[Claims] 1. (a) Two or more polymer blocks A comprising a vinyl aromatic compound and a conjugated diene compound, wherein at least 35% of carbon-carbon double bonds based on the conjugated diene compound are hydrogenated. 100 parts by weight of a hydrogenated block copolymer having at least one polymer block B having a vinyl aromatic compound content of 5 to 75% by weight, and (b) a softener for a non-aromatic rubber 30 to 200 parts by weight, (c) 10 to 100 parts by weight of a polyolefin resin, and (d) a specific gravity of 3 having a mean particle size of 0.5 to 2 μm and a sieve residue of 325 mesh of 0.01% by weight or less is 3% A thermoplastic resin composition comprising 30 to 100 parts by weight of the above inorganic particles.