JP6073645B2 - Polypropylene resin composition and molded product thereof - Google Patents

Description

  The present invention relates to a polypropylene resin composition and a molded product thereof. More specifically, by adjusting the ratio of the melt flow rate of the polypropylene resin and styrene thermoplastic elastomer, the polypropylene has low specific gravity and improved ductility, heat resistance, impact resistance, etc. without impairing the original properties of the polypropylene resin. The present invention relates to a resin composition and a molded product thereof.

  Polypropylene resin is excellent in heat resistance, molding processability, mechanical properties, chemical resistance, etc., and is inexpensive, so it has a wide range of industrial applications, including electrical and electronic parts, home appliances, housings, packaging materials, and automotive parts. It is used. Furthermore, in recent years, it has been widely used for automobile applications such as bumpers and interior / exterior parts due to the demand for automobile weight reduction. Especially for automobile bumper applications, the material must have rigidity, heat resistance, and fluidity depending on the shape of the product. Therefore, it is commercialized by compounding with an inorganic filler such as talc. However, such compounding with an inorganic filler increases the specific gravity and is contrary to weight reduction.

  Therefore, as a method for reducing the weight and increasing the strength of the polypropylene resin, a method of blending a polypropylene resin with a high-strength polymer has been studied. In particular, since a polycarbonate resin is excellent in heat resistance, impact resistance, etc., a blend of a polypropylene resin and a polycarbonate resin is expected to exhibit good characteristics.

  However, the compatibility between the polypropylene resin and the polycarbonate resin is not good, and there is a problem of delamination and significant physical property deterioration. Therefore, various resin compositions have been proposed for the purpose of improving the compatibility. For example, a resin composition using an elastomer graft-modified with a hydroxyl group-containing vinyl monomer as a compatibilizing agent has been proposed. (Refer to Patent Documents 1 and 2) However, although the impact resistance is good in this composition, since the compatibilizing effect is not sufficient, it is necessary to improve heat resistance and mechanical strength. In addition, a resin composition has been proposed in which polypropylene modified with a hydroxyl group-containing vinyl monomer is used as a compatibilizing agent, and an ethylene-α-olefin copolymer composed of ethylene and an α-olefin having 4 or more carbon atoms is used as an impact resistance agent. Yes. However, although this composition is excellent in impact resistance and rigidity, there is no description about compatibility. Furthermore, a resin composition using a styrene-ethylene / butylene-styrene block copolymer as a compatibilizing agent has been proposed. However, although this composition is excellent in compatibility, the ratio of the melt flow rate between the polypropylene resin and the styrene-ethylene-butylene-styrene block copolymer is large, and the impact properties and tensile properties are high. Improvement effect is insufficient.

JP-A-7-330972 JP-A-8-134277 JP 2005-132937 A Japanese Patent Laid-Open No. 5-17633

  As described above, there is a demand for a resin composition that does not have delamination and has low specific gravity, high ductility, high heat resistance, and high impact properties. However, no method for obtaining such a resin composition is disclosed. is the current situation. Accordingly, an object of the present invention is to provide such a resin composition.

  As a result of intensive investigations in view of the above-mentioned problems of the prior art, the inventor has solved the delamination by adjusting the ratio of the melt flow rate of the polypropylene resin and the styrenic thermoplastic elastomer, and further the original polypropylene resin. As a result of further investigations, the inventors have reached the present invention as a result of obtaining high ductility, high heat resistance, and high impact resistance with a low specific gravity without impairing the above characteristics. According to the present invention, the above-mentioned problems are solved with respect to 100 parts by weight of a resin component consisting of (1) (A) polypropylene resin (component A) 50 to 90 parts by weight and (B) polycarbonate resin (component B) 10 to 50 parts by weight. , Containing 3 to 15 parts by weight of a styrenic thermoplastic elastomer (component C), and a ratio of the melt flow rate (230 ° C., load 2.16 kg) of the polypropylene resin and the styrenic thermoplastic elastomer (component MFR / C component) The MFR) is 0.1 to 5 and is achieved by a polypropylene resin composition.

One of the preferred embodiments of the present invention is the resin composition having the above constitution (1), wherein (2) the styrenic thermoplastic elastomer is a styrene-ethylene / butylene-styrene copolymer.
One of the preferred embodiments of the present invention is (3) the resin composition having the above constitution (1) or (2), wherein the styrene-based thermoplastic elastomer has a weight average molecular weight of 250,000 or less.
One of the preferred embodiments of the present invention is (4) a molded article for electric / electronic parts, automobile parts or OA equipments using the polypropylene resin composition of any one of the above constitutions (1) to (3). It is.

Hereinafter, the present invention will be described in more detail.
(A component: polypropylene resin)
The resin composition of the present invention contains a polypropylene resin as the component A. Polypropylene resin is a polymer of propylene, but in the present invention, it also includes copolymers with other monomers. Examples of the polypropylene resin of the present invention include a homopolypropylene resin, a block copolymer of propylene, ethylene, and an α-olefin having 4 to 10 carbon atoms (also referred to as “block polypropylene”), propylene, ethylene, and 4 to 4 carbon atoms. 10 random copolymers with α-olefin (also referred to as “random polypropylene”). “Block polypropylene” and “random polypropylene” are also collectively referred to as “polypropylene copolymer”.

In the present invention, one or more of the above-mentioned homopolypropylene resin, block polypropylene, and random polypropylene may be used as the polypropylene resin, and among them, homopolypropylene and block polypropylene are preferable.
Examples of the α-olefin having 4 to 10 carbon atoms used for the polypropylene copolymer include 1-butene, 1-pentene, isobutylene, 3-methyl-1-butene, 1-hexene, and 3,4-dimethyl-1. -Butene, 1-heptene, 3-methyl-1-hexene are included.

The content of ethylene in the polypropylene copolymer is preferably 5% by mass or less in all monomers. The content of the α-olefin having 4 to 10 carbon atoms in the polypropylene copolymer is preferably 20% by mass or less in all monomers.
The polypropylene copolymer is preferably a copolymer of propylene and ethylene or a copolymer of propylene and 1-butene, and particularly preferably a copolymer of propylene and ethylene.

  The melt flow rate (230 ° C., 2.16 kg) of the polypropylene resin in the present invention is preferably 0.05 to 40 g / 10 min, more preferably 0.5 to 30 g / 10 min, and 0.5 to It is especially preferable that it is 20 g / 10min. If the melt flow rate of the polypropylene resin is outside the above range, the properties of the polypropylene resin composition may be insufficient. The melt flow rate is also called “MFR”. MFR was measured at 230 ° C. and 2.16 kg load according to ISO1133.

(B component: polycarbonate resin)
The polycarbonate resin used as the component B in the present invention is obtained by reacting a dihydric phenol and a carbonate precursor. Examples of the reaction method include an interfacial polymerization method, a melt transesterification method, a solid phase transesterification method of a carbonate prepolymer, and a ring-opening polymerization method of a cyclic carbonate compound.

  Representative examples of the dihydric phenol used here include hydroquinone, resorcinol, 4,4′-biphenol, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl). ) Propane (commonly called bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl)- 1-phenylethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxyphenyl) Pentane, 4,4 ′-(p-phenylenediisopropylidene) diphenol, 4,4 ′-(m-phenylenediisopropyl Pyridene) diphenol, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ester, bis (4-hydroxy-3-methylphenyl) sulfide, 9,9-bis (4-hydroxyphenyl) Examples include fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene. A preferred dihydric phenol is bis (4-hydroxyphenyl) alkane, and bisphenol A is particularly preferred from the viewpoint of excellent toughness and deformation characteristics, and is widely used.

  In the present invention, in addition to the general-purpose polycarbonate bisphenol A-based polycarbonate, a special polycarbonate produced using other dihydric phenols can be used as the A component. For example, as part or all of the dihydric phenol component, 4,4 ′-(m-phenylenediisopropylidene) diphenol (hereinafter sometimes abbreviated as “BPM”), 1,1-bis (4-hydroxy Phenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (hereinafter sometimes abbreviated as “Bis-TMC”), 9,9-bis (4-hydroxyphenyl) Polycarbonate (homopolymer or copolymer) using fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (hereinafter sometimes abbreviated as “BCF”) has dimensions due to water absorption. It is suitable for applications where the demands for change and shape stability are particularly severe. These dihydric phenols other than BPA are preferably used in an amount of 5 mol% or more, particularly 10 mol% or more of the entire dihydric phenol component constituting the polycarbonate.

In particular, when high rigidity and better hydrolysis resistance are required, it is particularly preferable that the component A constituting the resin composition is a copolymerized polycarbonate of the following (1) to (3). is there.
(1) In 100 mol% of the dihydric phenol component constituting the polycarbonate, the BPM component is 20 to 80 mol% (more preferably 40 to 75 mol%, more preferably 45 to 65 mol%), and A copolymeric polycarbonate in which the BCF component is 20 to 80 mol% (more preferably 25 to 60 mol%, more preferably 35 to 55 mol%).
(2) In 100 mol% of the dihydric phenol component constituting the polycarbonate, the BPA component is 10 to 95 mol% (more preferably 50 to 90 mol%, more preferably 60 to 85 mol%), and A copolymeric polycarbonate in which the BCF component is 5 to 90 mol% (more preferably 10 to 50 mol%, more preferably 15 to 40 mol%).
(3) In 100 mol% of the dihydric phenol component constituting the polycarbonate, the BPM component is 20 to 80 mol% (more preferably 40 to 75 mol%, more preferably 45 to 65 mol%), and Copolymer polycarbonate in which the Bis-TMC component is 20 to 80 mol% (more preferably 25 to 60 mol%, still more preferably 35 to 55 mol%).

These special polycarbonates may be used alone or in combination of two or more. Moreover, these can also be mixed and used for the bisphenol A type polycarbonate generally used.
The production method and characteristics of these special polycarbonates are described in detail in, for example, JP-A-6-172508, JP-A-8-27370, JP-A-2001-55435, and JP-A-2002-117580. ing.

Of the various polycarbonates described above, those having a water absorption and Tg (glass transition temperature) adjusted within the following ranges by adjusting the copolymer composition, etc. have good hydrolysis resistance of the polymer itself, and Since it is remarkably excellent in low warpage after molding, it is particularly suitable in a field where form stability is required.
(I) polycarbonate having a water absorption of 0.05 to 0.15%, preferably 0.06 to 0.13% and Tg of 120 to 180 ° C, or (ii) Tg of 160 to 250 ° C, Polycarbonate which is preferably 170 to 230 ° C. and has a water absorption of 0.10 to 0.30%, preferably 0.13 to 0.30%, more preferably 0.14 to 0.27%.

Here, the water absorption of the polycarbonate is a value obtained by measuring the moisture content after being immersed in water at 23 ° C. for 24 hours in accordance with ISO 62-1980 using a disc-shaped test piece having a diameter of 45 mm and a thickness of 3.0 mm. is there. Moreover, Tg (glass transition temperature) is a value calculated | required by the differential scanning calorimeter (DSC) measurement based on JISK7121.
As the carbonate precursor, carbonyl halide, carbonic acid diester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

  In producing a polycarbonate resin by interfacial polymerization of the above dihydric phenol and carbonate precursor, a catalyst, a terminal terminator, an antioxidant for preventing the dihydric phenol from being oxidized, etc., as necessary. May be used. The polycarbonate resin of the present invention is a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin copolymerized with an aromatic or aliphatic (including alicyclic) difunctional carboxylic acid. And a copolymer polycarbonate resin copolymerized with a bifunctional alcohol (including alicyclic), and a polyester carbonate resin copolymerized with the bifunctional carboxylic acid and the bifunctional alcohol together. Moreover, the mixture which mixed 2 or more types of the obtained polycarbonate resin may be sufficient.

The branched polycarbonate resin increases the melt tension of the resin composition of the present invention, and can improve the molding processability in extrusion molding, foam molding and blow molding based on such properties. As a result, a molded product by these molding methods, which is superior in dimensional accuracy, is obtained.
Examples of the trifunctional or higher polyfunctional aromatic compound used in the branched polycarbonate resin include 4,6-dimethyl-2,4,6-tris (4-hydroxydiphenyl) heptene-2, 2,4,6- Trimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, 1,1 , 1-tris (3,5-dimethyl-4-hydroxyphenyl) ethane, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, and 4- {4- [1,1- Trisphenol such as bis (4-hydroxyphenyl) ethyl] benzene} -α, α-dimethylbenzylphenol is preferably exemplified. Other polyfunctional aromatic compounds include phloroglucin, phloroglucid, tetra (4-hydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) ketone, 1,4-bis (4,4-dihydroxytriphenylmethyl) benzene. And trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, and acid chlorides thereof. Of these, 1,1,1-tris (4-hydroxyphenyl) ethane and 1,1,1-tris (3,5-dimethyl-4-hydroxyphenyl) ethane are preferable, and 1,1,1-tris (4- Hydroxyphenyl) ethane is preferred.

The structural unit derived from the polyfunctional aromatic compound in the branched polycarbonate resin is preferably in a total of 100 mol% of the structural unit derived from the dihydric phenol and the structural unit derived from the polyfunctional aromatic compound. Is 0.03 to 1 mol%, more preferably 0.07 to 0.7 mol%, particularly preferably 0.1 to 0.4 mol%.
Further, such a branched structural unit is not only derived from a polyfunctional aromatic compound but also derived without using a polyfunctional aromatic compound, such as a side reaction during a melt transesterification reaction. Also good. The ratio of such a branched structure can be calculated by ¹ H-NMR measurement.

  The aliphatic bifunctional carboxylic acid is preferably α, ω-dicarboxylic acid. Examples of aliphatic difunctional carboxylic acids include sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and linear saturated aliphatic dicarboxylic acids such as icosanedioic acid, and cyclohexanedicarboxylic acid. Preferred are alicyclic dicarboxylic acids such as acids. As the bifunctional alcohol, an alicyclic diol is more preferable, and examples thereof include cyclohexanedimethanol, cyclohexanediol, and tricyclodecane dimethanol.

Further, a polycarbonate-polyorganosiloxane copolymer obtained by copolymerizing polyorganosiloxane units can also be used.
The reaction forms such as interfacial polymerization, melt transesterification, solid phase transesterification of carbonate prepolymer, and ring-opening polymerization of cyclic carbonate compounds, which are methods for producing the polycarbonate resin of the present invention, are various documents and patent publications. This is a well-known method.

In producing the resin composition of the present invention, the viscosity average molecular weight (M) of the polycarbonate resin is not particularly limited, but is preferably 1 × 10 ^{4 to} 5 × 10 ⁴ , more preferably 1.4 × 10 ^4. a to 3 × 10 ^4, more preferably from ^{1.4 × 10 4 ~2.4 × 10 4} . A polycarbonate resin having a viscosity average molecular weight of less than 1 × 10 ⁴ may not provide practically sufficient toughness and crack resistance. On the other hand, a resin composition obtained from a polycarbonate resin having a viscosity average molecular weight exceeding 5 × 10 ⁴ generally has a low versatility because it generally requires a high molding temperature or requires a special molding method. A high molding temperature tends to cause deterioration of the deformation characteristics and rheological characteristics of the resin composition.

The polycarbonate resin may be obtained by mixing those having a viscosity average molecular weight outside the above range. In particular, a polycarbonate resin having a viscosity average molecular weight exceeding the above value (5 × 10 ⁴ ) increases the melt tension of the resin composition of the present invention, and molding in extrusion molding, foam molding and blow molding based on such characteristics. Processability can be improved. Such an improvement effect is even better than the branched polycarbonate.

As a more preferable aspect, the B component is a polycarbonate resin (B-3-1 component) having a viscosity average molecular weight of 7 × 10 ⁴ to 2 × 10 ^{6, and} a polycarbonate resin having a viscosity average molecular weight of 1 × 10 ^{4 to} 3 × 10 ⁴ (B-3-2 component), and the viscosity average molecular weight is 1.6 × 10 ^{4 to} 3.5 × 10 ⁴ polycarbonate resin (B-3 component) (hereinafter, “high molecular weight component-containing polycarbonate resin”) May also be used).

In such a high molecular weight component-containing polycarbonate resin (B-3 component), the molecular weight of the B-3-1 component is preferably 7 × 10 ^{4 to} 3 × 10 ⁵ , more preferably 8 × 10 ⁴ to 2 × 10 ⁵ , preferably ^{1 × 10 5 ~2 × 10 5} , particularly preferably ^{1 × 10 5 ~1.6 × 10 5} . The molecular weight of the B-3-2 component is preferably 1 × 10 ^{4 to} 2.5 × 10 ⁴ , more preferably 1.1 × 10 ^{4 to} 2.4 × 10 ⁴ , and even more preferably 1.2 × 10 ^4. to 2.4 × 10 ^4, particularly preferably ^{1.2 × 10 4 ~2.3 × 10 4} .

  The high molecular weight component-containing polycarbonate resin (B-3 component) can be obtained by mixing the B-3-1 component and the B-3-2 component at various ratios and adjusting them so as to satisfy a predetermined molecular weight range. . Preferably, in 100% by weight of the B-3 component, the B-3-1 component is 2 to 40% by weight and the B-3-2 component is 60 to 98% by weight, more preferably the B-3-1 component is 5 to 20% by weight and B-3-2 component is 80 to 95% by weight. Usually, the molecular weight distribution of the polycarbonate resin is in the range of 2-3. Therefore, it is preferable that the B-3-1 component and the B-3-2 component of the present invention satisfy the molecular weight distribution range. The molecular weight distribution is represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) calculated by GPC (gel permeation chromatography) measurement. And Mw is based on standard polystyrene conversion.

  As a method for preparing the B-3 component, (1) a method of independently polymerizing the B-3-1 component and the B-3-2 component and mixing them, and (2) JP-A-5-306336. The method of producing an aromatic polycarbonate resin showing a plurality of polymer peaks in the molecular weight distribution chart by GPC method represented by the method shown in the publication No. 1 in the same system, such an aromatic polycarbonate resin is represented by B- of the present invention. A method of producing so as to satisfy the condition of one component, and (3) an aromatic polycarbonate resin obtained by such a production method (production method of (2)), a separately produced B-3-1 component and / or Examples thereof include a method of mixing the B-3-2 component.

The viscosity average molecular weight referred to in the present invention is first determined by using an Ostwald viscometer from a solution in which 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride at 20 ° C., with a specific viscosity (η _SP ) calculated by the following formula:
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]
The viscosity average molecular weight M is calculated from the determined specific viscosity (η _SP ) by the following formula.
η _SP /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
c = 0.7

  The calculation of the viscosity average molecular weight in the resin composition of the present invention is performed as follows. That is, the composition is mixed with 20 to 30 times its weight of methylene chloride to dissolve the soluble component in the composition. Such soluble matter is collected by Celite filtration. Thereafter, the solvent in the obtained solution is removed. The solid after removal of the solvent is sufficiently dried to obtain a solid component that dissolves in methylene chloride. A specific viscosity at 20 ° C. is determined from a solution obtained by dissolving 0.7 g of the solid in 100 ml of methylene chloride in the same manner as described above, and the viscosity average molecular weight M is calculated from the specific viscosity in the same manner as described above.

  The composition ratio of the polypropylene resin (component A) and the polycarbonate resin (component B) in the resin composition of the present invention is 100 parts by weight in total, and the component A is 50 to 90 parts by weight, preferably 50 to 80 parts by weight. More preferably, it is 50-75 weight part, B component is 10-50 weight part, Preferably it is 20-50 weight part, More preferably, it is 25-50 weight part. When the component A is less than 50 parts by weight, the moldability and ductility are lowered and the specific gravity is increased. If it exceeds 90 parts by weight, the effect of improving strength and heat resistance will be insufficient.

(C component: Styrenic thermoplastic elastomer)
The resin composition of the present invention contains a styrenic thermoplastic elastomer as the C component. Examples of the styrenic thermoplastic elastomer used in the present invention include a styrene-ethylene / butylene-styrene block copolymer, a styrene-hydrogenated butadiene-styrene triblock copolymer, a styrene-isoprene-styrene triblock copolymer, and styrene. -Hydrogenated isoprene-styrene triblock copolymer, styrene-hydrogenated butadiene diblock copolymer, styrene-hydrogenated isoprene block copolymer, styrene-isoprene block copolymer, etc., among them styrene -Ethylene butylene-styrene block copolymer is most preferred. In addition, the following formula (I) or (II)
X- (Y-X) _n (I)
(XY) _n (II)
Is also suitably used as a compatibilizing agent. X in the general formulas (I) and (II) is a styrene polymer block, and in the formula (I), the degree of polymerization may be the same or different at both ends of the molecular chain. Y is at least one selected from an isoprene polymer block, a hydrogenated butadiene polymer block, and a hydrogenated isoprene polymer block. N is an integer of 1 or more.

  The content of the X component in the block copolymer is 20 to 80% by weight, preferably 25 to 70% by weight. If this amount is less than 20% by weight, the rigidity of the resin composition tends to decrease, and if it exceeds 80% by weight, the moldability and impact strength tend to decrease. Specific examples of such a block copolymer include a styrene-hydrogenated butadiene-styrene triblock copolymer, a styrene-isoprene-styrene triblock copolymer, a styrene-hydrogenated isoprene-styrene triblock copolymer, Examples thereof include a styrene-hydrogenated butadiene diblock copolymer, a styrene-hydrogenated isoprene block copolymer, and a styrene-isoprene block copolymer.

  The weight average molecular weight of the styrenic thermoplastic elastomer is preferably 250,000 or less, more preferably 220,000 or less, and even more preferably 200,000 or less. When the weight average molecular weight exceeds 250,000, the molding processability is lowered, and the dispersibility in the polypropylene resin is also deteriorated. The lower limit of the weight average molecular weight is not particularly limited, but is preferably 40,000 or more, more preferably 50,000 or more. The weight average molecular weight was measured by the following method. That is, the molecular weight was measured in terms of polystyrene by gel permeation chromatography, and the weight average molecular weight was calculated.

  Content of C component is 3-15 weight part with respect to a total of 100 weight part of A component and B component, Preferably it is 5-13 weight part, More preferably, it is 5-10 weight part. If the content is less than 3 parts by weight, the strength is reduced due to delamination during the tensile test, and if it exceeds 15 parts by weight, the heat resistance is deteriorated.

  The ratio of the melt flow rate (230 ° C., load 2.16 kg) of the polypropylene resin and the styrenic thermoplastic elastomer (A component MFR / C component MFR) is 0.1 to 5, preferably 0.2. -5, more preferably 0.3-5, particularly preferably 0.4-5. When this ratio is less than 0.1, the dispersion of the styrene-based thermoplastic elastomer is deteriorated, and the strength is reduced due to delamination during the tensile test. Even if it exceeds 5, the strength decreases due to delamination during the tensile test. In addition, the measuring method of MFR of a styrene-type thermoplastic elastomer is the same as the measuring method of the said polypropylene resin.

(Other additives)
Further, the composition of the present invention may further include an inorganic filler, an organic filler, an antioxidant, a heat stabilizer, a light stabilizer, a flame retardant, a lubricant, an antistatic agent, an inorganic or organic colorant, if necessary. Additives such as a rust preventive agent, a crosslinking agent, a foaming agent, a fluorescent agent, a surface smoothing agent, a surface gloss improving agent, and a mold release improving agent such as a fluororesin may be included.

(Production of polypropylene resin composition)
The composition of the present invention is obtained by blending each component. Examples of blending include melt-kneading and mixing various components in a solvent. The composition of the present invention may be produced arbitrarily as long as the effects of the invention are not impaired, but is preferably produced by melt-kneading using a high-kneading biaxial extruder. Hereinafter, the manufacturing method will be described.

The composition of the present invention comprises:
1) A process of supplying various components to a twin screw extruder using a feeder (process 1),
2) Step of melt kneading while setting the cylinder and die set temperature of 160 to 290 ° C. of the twin screw extruder while vacuum degassing the inside of the twin screw extruder (step 2)
It is preferable to be manufactured through.

In step 1, the components may be mixed uniformly in advance with an apparatus such as a tumbler or a Henschel mixer, or may be omitted and supplied to a feeder if necessary. The feeder is a device that can supply a certain amount of raw material to a twin-screw extruder (hereinafter referred to as “kneading device”), and is equipped in the kneading device. Examples of the feeder include a twin screw extruder different from a metering feeder, a single screw extruder, or a kneading apparatus.
In the melt kneading in step 2, the set temperature of the cylinder and die of the kneading device is preferably 160 to 290 ° C, more preferably 180 to 260 ° C. The melt-kneading time varies depending on the blending ratio of each component, the melt-kneading temperature, and the like, and is not limited to one, but is preferably about 1 to 30 minutes. The kneading apparatus in this step is preferably a high-kneading twin screw extruder.

(About a molded article made of the resin composition of the present invention)
The resin composition in the present invention is produced by injection molding, extrusion molding, blow molding, by a known processing method such as injection molding, extrusion molding, blow molding, hollow molding, rotational molding, transfer molding, hot press molding, tube molding, and the like. Can be formed into a molded body, a hollow molded body, a rotational molded body, a transfer molded body, a press molded body, a tube molded body, and the like. The resin composition of the present invention is, for example, a T-die method for extruding and winding a molten resin from a T-die, an inflation film-forming method for extruding a molten resin into a cylindrical shape from an extruder provided with an annular die, and cooling and winding it. Alternatively, a molded product can be obtained as a film or a sheet by a hot press method or a solvent casting method.

  The composition of the present invention is excellent in ductility, impact resistance and heat resistance, and is lightweight and inexpensive. Therefore, the composition of the present invention is suitable as an electric / electronic device part, a home appliance part, an OA equipment part, or an automobile interior / exterior part. Examples of automotive interior and exterior components include automotive skins, doors, door trims, quarter trims, bumpers, instrument panels, front end modules, airbag peripheral components, cockpits, fan shrouds, radiator cooling fans, reserve tanks, automotive wheel covers Automobile parts such as cowling, window washer fluid tank, spoiler, instrument panel, bonnet, fuel pump housing, air cleaner, slot body, intake manifold, heater housing, bonnet, pillar, safety belt parts. Among these, automobile outer plates, doors, bumpers, automobile wheel covers, doors, door trims, pillars, instrument panels, and airbag peripheral parts are particularly preferable. In addition, the composition of the present invention can be widely applied to electric / electronic parts, home appliance parts, packaging materials, architectural interior materials, containers, films, sheets, bottles, housings, mechanical parts, and the like.

  The polypropylene resin composition of the present invention is excellent in ductility, heat resistance, impact resistance and the like with a low specific gravity without impairing the original properties of the polypropylene resin. Therefore, the polypropylene resin composition of the present invention is widely useful in automobile applications and other various fields. Therefore, the industrial effect of the present invention is extremely great.

  The form of the invention that the present inventor considers to be the best is an aggregation of the preferable ranges of the above requirements. For example, typical examples are described in the following examples. Of course, the present invention is not limited to these forms.

Hereinafter, examples will be described further. Evaluation was carried out by the following method.
(I) Melt flow rate (MFR)
Based on ISO1133, MFR (g / 10min) was measured at 230 ° C. and a load of 2.16 kg. In addition, what dried the pellet for 5 hours at 100 degreeC was used for the test.
(Ii) Weight average molecular weight Using a gel permeation chromatograph, the molecular weight was measured in terms of polystyrene, and the weight average molecular weight was calculated.
(Iii) Specific gravity Measured according to ASTM D 792.
(Iv) Tensile properties (elongation at break, strength at break)
Measurement was performed at a tensile speed of 100 mm / min in accordance with ISO 527. The test piece was a dumbbell-type test piece, and the parallel part shape was 25 mm long × 4 mm wide × 2 mm thick.
(V) Deflection temperature under load (HDT)
The deflection temperature under load (° C.) was measured at a load of 0.45 MPa according to ISO75. The shape of the test piece was 80 mm long × 10 mm wide × 4 mm thick.
(Vi) Izod impact strength Izod impact strength (kJ / m ² ) was measured in accordance with ASTM D256. The shape of the test piece was 80 mm long × 10 mm wide × 4 mm thick.
(Vii) Peeling test 100 grids of 1 mm square are cut into a grid of 50 mm long x 45 mm wide x 2 mm thick with a cutter. Subsequently, cellophane tape was applied on the grid and evaluated by the presence or absence of peeling of the sample surface.

[Examples 1-7, Comparative Examples 1-9]
The resin composition which consists of a mixture ratio of Table 1 and Table 2 was created in the following ways. The description will be made according to the symbols in the following table. Each component of the ratio of the table | surface was measured, it mixed uniformly using the tumbler, this mixture was thrown into the extruder, and preparation of the resin composition was performed. As the extruder, a vent type twin screw extruder (Kobe Steel Works KTX-30) having a diameter of 30 mmφ was used. The screw configuration is the first stage kneading zone (consisting of 2 feed kneading discs, 1 feed rotor, 1 return rotor and 1 return kneading disc) before the vent position. Thereafter, a second-stage kneading zone (consisting of a feed rotor × 1 and a return rotor × 1) was provided. The strand was extruded under the conditions of cylinder temperature and die temperature of 290 ° C. and vent suction of 3000 Pa, cooled in a water bath, then strand-cut with a pelletizer and pelletized. The obtained pellets were dried in a hot air circulation dryer at 100 ° C. for 5 hours, and then a test piece for evaluation was molded using an injection molding machine. The injection molding machine used was a NP7 type Real Mini manufactured by Nissei Plastic Industry Co., Ltd., and the molding conditions were a cylinder temperature of 230 ° C. and a mold temperature of 50 ° C. The evaluation results are shown in Tables 1 and 2.

In addition, each component of symbol description in Table 1 and Table 2 is as follows.
(Component A)
A-1: Homopolypropylene resin [Nobrene W101 (product name) manufactured by Sumitomo Chemical Co., Ltd., MFR (230 ° C., 2.16 kg load) = 9.0 g / 10 min, specific gravity 0.9]
A-2: Homopolypropylene [E111G (product name) manufactured by Prime Polymer Co., Ltd., MFR (230 ° C., 2.16 kg load) = 0.5 g / 10 min, specific gravity 0.9]
A-3: Homopolypropylene [Nippon Polypro Co., Ltd. Novatec FY4 (product name), MFR (230 ° C., 2.16 kg load) = 5.0 g / 10 min, specific gravity 0.9]
(B component)
B-1: Polycarbonate resin [Panlite L-1225L (product name) manufactured by Teijin Chemicals Ltd., Mv = 19,700]
(C component)
C-1: Styrene-ethylene-butylene-styrene block copolymer [G1657 (product name) manufactured by Kraton Polymer Co., Ltd.], MFR (230 ° C., 2.16 kg load) = 9.0 g / 10 min, Mw = 150,000 ]
C-2: Styrene-ethylene / butylene-styrene block copolymer [Taftec H1041 (product name) manufactured by Asahi Kasei Chemicals Corporation, MFR (230 ° C., 2.16 kg load) = 5.0 g / 10 min, Mw = 209, 000]
C-3: Styrene-ethylene-butylene-styrene block copolymer [Taftec H1051 (product name) manufactured by Asahi Kasei Chemicals Corporation, MFR (230 ° C., 2.16 kg load) = 0.8 g / 10 min, Mw = 100, 000]
C-4: Styrene-ethylene-butylene-styrene block copolymer [Kuraray Co., Ltd. Septon 8007 (product name), MFR (230 ° C., 2.16 kg load) = 2.0 g / 10 min, Mw = 80,000 ]

  Styrene prepared by adjusting the ratio of melt flow rate (230 ° C., load 2.16 kg) of polypropylene resin and styrene thermoplastic elastomer (MFR of component A / MFR of component C) from Examples 1 to 7 and Comparative Examples 1 to 9 It is clear that a polypropylene resin composition containing a thermoplastic elastomer and a polycarbonate resin is excellent in ductility, heat resistance, impact resistance, and peelability.

Claims (3)

(A) Polypropylene resin (component A) 50 to 90 parts by weight, (B) Polycarbonate resin (component B) 10 to 50 parts by weight of resin component 100 parts by weight, styrene-ethylene / butylene-styrene copolymer ( C component) containing 3 to 15 parts by weight, and the ratio of the melt flow rate (230 ° C., load 2.16 kg) between the polypropylene resin and the styrenic thermoplastic elastomer (MFR of component A / MFR of component C) is 0. 63 polypropylene resin composition which is a 5. Polypropylene resin composition of claim 1 Symbol placement, wherein the weight-average molecular weight of the styrene thermoplastic elastomer is 250,000 or less. Claim 1 or 2 polypropylene resin composition formed from electrical and electronic parts for molded article according to the molded article is selected from automobile parts moldings and the group consisting of molded article OA equipment.