JP3220416B2 - Resin composition with excellent vibration damping properties and low-temperature impact properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oil resistance, chemical resistance, heat resistance, impact resistance, particularly vibration damping and low temperature impact resistance, which can be used in the fields of electric / electronics, automobiles, and various other industrial materials. And a polymer composition having an excellent balance of

[0002]

2. Description of the Related Art Polypropylene resins are known to be excellent in moldability, water resistance, oil resistance, acid resistance, alkali resistance and the like, but have drawbacks inferior in heat resistance, rigidity and impact resistance. .

On the other hand, polyphenylene ether is known to have poor mechanical properties, electrical properties, heat resistance, low-temperature properties, low water absorption and excellent dimensional stability, but poor molding workability and oil resistance. I have.

Therefore, in order to compensate for these drawbacks, the concept of a polymer alloy in which a polypropylene resin is mixed with a polyphenylene ether resin so that the polypropylene resin forms a matrix and the polyphenylene ether resin forms dispersed particles, Many concepts of polymer alloys with inverted sea-island structures have been proposed.

For example, US Pat. No. 3,361,851 proposes to improve solvent resistance and impact resistance by blending polyphenylene ether with polyolefin. 856
No. 4,145,37 describes a method for improving impact resistance and solvent resistance by blending polyphenylene ether or polyphenylene ether and a styrene resin with a hydrogenated block copolymer.
In the specification of Japanese Patent No. 7, polyphenylene ether or polyphenylene ether and a styrene resin are mixed with a polyolefin / hydrogenated block copolymer = 20 to 80 parts by weight / 80 to
There is a description of improving impact resistance and solvent resistance by blending with a premix consisting of 20 parts by weight and a hydrogenated block copolymer.
No. 055 and U.S. Pat. No. 4,239,673 describe the improvement of impact resistance by blending polyphenylene ether with hydrogenated block copolymers and polyolefins. U.S. Pat. No. 4,383,082 and EP-A-115,712 disclose that polyphenylene ether is blended with a polyolefin and a hydrogenated block copolymer to improve the impact resistance. ing.

Further, Japanese Patent Application Laid-Open Nos. 63-113058 and 63-225642, US Pat. No. 4,863,997, and Japanese Patent Application Laid-Open No. 2-305
814, JP-A-3-72512, JP-A-4-183748, and JP-A-5-320
No. 471 proposes a resin composition excellent in chemical resistance and processability by blending a specific hydrogenated block copolymer for modifying a resin composition comprising a polyolefin resin and a polyphenylene ether resin. .

Further, Japanese Patent Application Laid-Open No. 7-165998 discloses a hydrogenated block copolymer in which the bonding form of a conjugated diene compound is specified as a compatibility modifier for a resin composition comprising a polyphenylene ether resin and a polyolefin resin. It has been proposed to use coalescence.

[0008]

In recent years, in the field of information equipment, high-speed rotation of a driving unit has been required with a large increase in information processing capacity and processing speed. Vibration due to rotation becomes remarkable,
In the worst case, noise is of course the cause of data reading errors and malfunctions, so the plastic materials used in these devices are required to have vibration damping performance at room temperature. .

Further, at present, there is a demand for almighty performance which sufficiently satisfies heat resistance, impact resistance, workability, and the like as basic properties as a plastic material, and also has excellent low-temperature impact strength. .

[0010] In particular, some of the resin compositions obtained by the above-mentioned prior art individually give resin compositions excellent in vibration damping performance and low-temperature impact strength. However, there are problems such as poor low-temperature impact strength, and a composition excellent in low-temperature impact strength is inferior in vibration damping performance. An object of the present invention is to provide a polymer composition containing a polypropylene resin and a polyphenylene resin that is excellent in vibration damping performance and low-temperature impact strength in view of the current situation.

[0011]

Means for Solving the Problems The present inventors have made it possible to impart a high level of compatibility to a composition containing a polypropylene resin and a polyphenylene ether resin, and to impart a vibration damping performance and a low-temperature impact resistance. As a result of intensive studies on a hydrogenated block copolymer that can be an admixture, delamination occurs when a hydrogenated block copolymer having a specific structure is used as an admixture for a composition containing a polypropylene resin and a polyphenylene ether resin. Have been found to provide an improved resin composition, and further provide a resin composition having a remarkably excellent balance between the contrary damping properties and low-temperature impact properties.

That is, the present invention relates to: (a) 5 to 95% by weight of a polypropylene resin, (b) 95 to 5% by weight of a polyphenylene ether resin, based on 100 parts by weight of the total of the above components (a) and (b).
(C) the block copolymer has a weight ratio of at least one polymer block A mainly composed of a vinyl aromatic compound, isoprene and butadiene of 80/20 to 20/80, and 1,2-vinyl A hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one copolymer block B of isoprene and butadiene having a total amount of the bond amount and the 3,4-vinyl bond amount of 50 to 80%. An object of the present invention is to provide a resin composition having excellent vibration damping properties and low-temperature impact properties, characterized by comprising 1 to 30 parts by weight of a polymer.

The polypropylene resin used as the component (a) in the present invention comprises a crystalline propylene homopolymer and
The crystalline propylene homopolymer portion obtained in the first step of polymerization and propylene, ethylene and / or at least one other α-olefin (for example, butene-1, hexene-1, etc.) are copolymerized in the second and subsequent steps of polymerization. A crystalline propylene-ethylene block copolymer having a propylene-ethylene random copolymer portion obtained by polymerization, and even a mixture of these crystalline propylene homopolymer and crystalline propylene-ethylene block copolymer. I don't care.

Such a polypropylene resin is usually prepared at a polymerization temperature of 0 to 100 ° C. and a polymerization pressure of 3 in the presence of a titanium halide catalyst or the like supported on a carrier such as titanium trichloride catalyst or magnesium chloride and an alkyl aluminum compound. It is obtained by polymerization in the range of 〜100 atm. At this time, it is also possible to add a chain transfer agent such as hydrogen to adjust the molecular weight of the polymer, and it is also possible to use a batch method or a continuous method as a polymerization method, butane, pentane, hexane, heptane A method such as solution polymerization or slurry polymerization in a solvent such as octane or octane can also be selected, and a bulk polymerization in a monomer without a solvent, a gas phase polymerization in a gaseous monomer, and the like can be applied.

Furthermore, in order to increase the isotacticity and polymerization activity of the obtained polypropylene in addition to the above-mentioned polymerization catalyst, an electron-donating compound can be used as an internal donor component or an external donor component as a third component. .

Known electron-donating compounds can be used, for example, ester compounds such as ε-caprolactone, methyl methacrylate, ethyl benzoate, methyl toluate, triphenyl phosphite, tributyl phosphite. Such as phosphites, phosphoric acid derivatives such as hexamethylphosphoric triamide, alkoxyester compounds, aromatic monocarboxylic acid esters and / or aromatic alkylalkoxysilanes, aliphatic hydrocarbonalkoxysilanes, and various ether compounds And various alcohols and / or various phenols.

The polypropylene resin used in the present invention may be any one having any crystallinity or melting point, as long as it can be obtained by the above-mentioned method, alone or in combination of two or more.

The polypropylene resin used in the present invention may be prepared by melting the above polypropylene resin and an α, β-unsaturated carboxylic acid or a derivative thereof in the presence or absence of a radical generator in addition to the above polypropylene resin. Status,
A known modified (0.01 to 10% by weight of the α, β-unsaturated carboxylic acid or a derivative thereof is grafted or added thereto) polypropylene resin obtained by reacting at a temperature of 30 to 350 ° C. in a solution state; And a mixture of the above-mentioned polypropylene resin and the modified polypropylene resin at an arbitrary ratio.

The polyphenylene ether resin (b) used in the present invention (hereinafter simply referred to as PPE) is
The PPE is an essential component for imparting heat resistance and flame retardancy to the polymer composition of the present invention.

[0020]

Embedded image

(Wherein R ₁ , R ₂ , R ₃ , and R ₄ are each hydrogen, halogen, a primary or secondary lower alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, An aminoalkyl group, a hydrocarbonoxy group or a group selected from the group consisting of a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom, which may be the same or different from each other ), Reduced viscosity (0.5 g / dl, chloroform solution,
(Measured at 30 ° C.) is a homopolymer and / or copolymer in the range of 0.15 to 0.70, more preferably in the range of 0.20 to 0.60.

Specific examples of the PPE include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly ( 2-methyl-6-phenyl-
1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like. Further, 2,6-dimethylphenol and other phenols (for example, 2,3,6-trimethyl) Polyphenylene ether copolymers such as phenol and 2-methyl-6-butylphenol). Among them, poly (2,6-dimethyl-1,4-phenylene ether),
Copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferred, and poly (2,6-dimethylphenol) is more preferred.
6-dimethyl-1,4-phenylene ether) is preferred.

The method for producing such PPE is not particularly limited as long as it can be obtained by a known method. For example, complex of cuprous salt and amine by Hay described in US Pat. No. 3,306,874 Can be easily produced, for example, by oxidative polymerization of 2,6-xylenol using as a catalyst.
Nos. 6,875, 3,257,357 and 3,257,358, JP-B-52-17880, JP-A-50-51197 and JP-A-63-1.
It can be easily manufactured by a method described in, for example, Japanese Patent No. 52628.

The PPE used in the present invention may be a mixture of the above-mentioned PPE and a styrene monomer and / or an α, β-unsaturated carboxylic acid or a derivative thereof in the absence of a radical generator. A known modification (the styrene monomer and / or the α, β-unsaturated carboxylic acid or derivative thereof is obtained in a molten state, a solution state, or a slurry state at a temperature of 80 to 350 ° C. under a temperature of 80 to 350 ° C.). (A graft or addition of 0 to 10% by weight) PPE, or a mixture of the above-mentioned PPE and the modified PPE in any ratio.

The PPE used in the present invention is the above-mentioned PPE.
In addition to PE, those obtained by adding polystyrene or high-impact polystyrene in an amount not exceeding 400 parts by weight to 100 parts by weight of these PPEs can also be suitably used.

Next, the hydrogenated block copolymer used as the component (c) in the present invention is obtained by melting and mixing the polypropylene resin (a) and the polyphenylene ether resin (b). A hydrogenated block having the ability to suitably finely disperse the polyphenylene ether resin in the polypropylene resin (a) or the finely disperse the polypropylene resin (a) in the polyphenylene ether resin (b). It is a polymer. That is,
In the present invention, the weight ratio of at least one polymer block A mainly composed of a vinyl aromatic compound to isoprene and butadiene is 80/20 to 20 /.
80, and the amount of 1,2-vinyl bond and 3,4-
A hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one copolymer block B of isoprene and butadiene having a total amount of vinyl bonds of 50 to 80% is used.

Examples of the block copolymer having such a structure include AB, ABA, and ABA-
B, ABABA, ABABAB, B
It is obtained by hydrogenating a block copolymer such as -AB.

Here, the ratio of isoprene and butadiene constituting the polymer block B before hydrogenation is 80/20.
-20/80 (weight ratio), preferably 70 / 30-30
/ 70, more preferably 60/40 to 40/60. If the proportion of the polymer block B containing isoprene exceeds 80% by weight, the resulting resin composition has a remarkably poor low-temperature impact resistance, which is not preferable. If the proportion of the polymer block B containing isoprene is less than 20% by weight, the obtained resin composition has poor vibration damping properties, which is not preferable.

Further, the amount of 1,2-vinyl bond and 3,4
-The total amount of vinyl bonds (hereinafter abbreviated as vinyl bond amount) is 50 to 80%, preferably 50 to 75%, more preferably 50 to 65%. When the vinyl bond amount of the polymer block B is less than 50%, the miscibility of the polypropylene resin and the polyphenylene ether resin deteriorates,
The delamination phenomenon occurs, which is not preferable. Further, when the vinyl bond amount of the polymer block B exceeds 80%, the miscibility of the polypropylene resin and the polyphenylene ether resin is good and the vibration damping performance is excellent, but the low-temperature impact resistance is remarkably deteriorated, which is not preferable. The amount of 1,2-vinyl bond or 3,4-vinyl bond is usually determined by using an infrared spectrophotometer or N
It can be known by MR or the like.

The hydrogenated block copolymer of the component (C) contains 15 to 95% by weight, preferably 20 to 70% by weight, more preferably 15 to 95% by weight of the vinyl aromatic compound bonded in the block copolymer before hydrogenation. Preferably, the content is 35 to 50% by weight.

Referring to the block structure, the polymer block A mainly composed of a vinyl aromatic compound contains more than 50% by weight of a homopolymer block of a vinyl aromatic compound or more preferably 70% by weight of a vinyl aromatic compound. It has a structure of a copolymer block of a vinyl aromatic compound and a conjugated diene compound contained above.

The polymer block A mainly composed of the vinyl aromatic compound and the weight ratio of the isoprene to butadiene are 80/20 to 20/80, and the amount of 1,2-vinyl bond and 3,4-vinyl bond The total amount is 50-8
The block copolymer comprising 0% of the copolymer block B has at least one or more of A and B, respectively, and each of the polymer blocks may have the same structure in terms of the molecular weight and the monomer composition ratio. It may be a structure.

As the vinyl aromatic compound constituting the block copolymer, for example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, diphenylethylene and the like can be used. It can be selected, and among them, styrene is preferable. The conjugated diene compound copolymerizable with the vinyl aromatic compound is, for example, one or two selected from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and the like. The above are selected, and among them, butadiene, isoprene and a combination thereof are preferable.

The block copolymer having the above structure has a number average molecular weight of 5,000 to 1,000,000,
It is preferably in the range of 10,000 to 800,000, more preferably in the range of 30,000 to 500,000, and has a molecular weight distribution [weight determined by monodispersion polystyrene molecular weight measured by gel permeation chromatography and used as a calibration curve. Average molecular weight (Mw) and number average molecular weight (M
n)] is 10 or less. Further, the molecular structure of the block copolymer may be linear, branched, radial, or any combination thereof.

The block copolymer having such a structure has a weight ratio of isoprene to butadiene of 80/20 to 20/80, and 1,2-
When the total amount of the vinyl bond amount and the 3,4-vinyl bond amount is 5
Hydrogenating reaction of at least one aliphatic double bond of at least one isoprene and butadiene copolymer block B of 0 to 80% to be used as the component (c) of the present invention as a hydrogenated block copolymer Can be. The hydrogenation rate of such aliphatic double bonds is at least more than 60%,
It is preferably at least 80%, more preferably at least 85% from the viewpoint of heat stability. The hydrogenation rate can usually be determined by iodine titration before and after the hydrogenation reaction, infrared spectrophotometer, NMR, and the like.

These hydrogenated block copolymers of component (c) may be obtained by any production method as long as they have the above-mentioned structure.
Examples of known production methods include, for example, JP-A-47-1
1486, JP-A-49-66743, JP-A-50-75651, JP-A-54-126255.
JP-A-56-10542, JP-A-56-10542
No. 62847, JP-A-56-100840,
JP-A-2-300218, British Patent 1,13
No. 0,770 and U.S. Pat. Nos. 3,281,383 and 3,639,517, and British Patent 1,020,720 and U.S. Pat.
There are methods described in 3,024 and 4,501,857.

The hydrogenated block copolymer of the component (c) used in the present invention may be, in addition to the hydrogenated block copolymer described above, the hydrogenated block copolymer and an α, β-unsaturated carboxylic acid. Or a derivative thereof in the presence, absence or presence of a radical generator in a molten state, a solution state, or a slurry state.
Known modified hydrogenated block copolymers obtained by reacting at a temperature of 50 ° C. (the α, β-unsaturated carboxylic acid or its derivative is grafted or added in an amount of 0.01 to 10% by weight) Further, a mixture of the above-mentioned hydrogenated block copolymer and the modified hydrogenated block copolymer in any ratio may be used.

The resin composition of the present invention has the above-mentioned (a) to
The component (c) is constituted as a basic component. The compounding amount of the polypropylene resin as the component (a) is 5 to 95% by weight, preferably 10 to 90% by weight. If the compounding amount is less than 5% by weight, the resulting polymer composition has excellent heat resistance, but is not preferable because of poor vibration damping performance, moldability and solvent resistance. On the other hand, if it exceeds 95% by weight, the moldability and solvent resistance are good, but the heat resistance is inferior and cannot be used as a heat resistant material.

The blending amount of the polyphenylene ether of the component (b) is 95 to 5% by weight, preferably 90 to 10% by weight. When the compounding amount exceeds 95% by weight, the heat resistance of the obtained polymer composition is extremely excellent, but the vibration damping performance, the moldability and the solvent resistance are inferior, which is not preferable. If the content is less than 5% by weight, the moldability and solvent resistance are excellent, but the heat resistance is inferior and cannot be used as a heat-resistant material.

The amount of the hydrogenated block copolymer of the component (c) is 1 to 30 parts by weight based on 100 parts by weight of the total of the components (a) and (b). If the amount is less than 1 part by weight, the effect as an admixture, the effect of improving vibration damping properties and the effect of improving low-temperature impact strength are not seen, which is not preferable. Further, even if the amount exceeds 30 parts by weight, the effect of improving the vibration damping property and the low-temperature impact strength is not remarkable, and conversely, the heat and solvent resistances of the effects of the components (a) and (b) are exhibited. , Rigidity and mechanical strength are undesirably reduced.

In the present invention, in addition to the above components, if necessary, other additional components such as a styrene-butadiene block having a bound styrene content of 10 to 90% may be used as long as the characteristics and effects of the present invention are not impaired. Polymer, bound styrene content 1
A hydrogenated block copolymer having a structure different from that of the present invention in which 0 to 90% of a styrene-isoprene block copolymer and 80% or more of an aliphatic double bond caused by a conjugated diene compound of the block copolymer are hydrogenated. Polymers, antioxidants, metal deactivators, flame retardants (organic phosphate ester compounds, inorganic phosphorus compounds, aromatic halogen flame retardants, silicone flame retardants, etc.), fluoropolymers, plasticizers (oils) , Low molecular weight polyethylene, epoxidized soybean oil,
Polyethylene glycol, fatty acid esters, etc.), flame retardant aids such as antimony trioxide, weather (light) improver, nucleating agent for polyolefin, slip agent, inorganic or organic filler and reinforcing material (glass fiber, carbon Fiber, polyacrylonitrile fiber, whisker, mica, talc, carbon black, titanium oxide, calcium carbonate, potassium titanate, wollastonite, conductive metal fiber, conductive carbon black, etc.), various colorants, release agents, etc. It may be added.

The resin composition of the present invention is obtained by melt-kneading the components (b) and (c) in advance using the above-described components and then melt-kneading the components together with the component (a).
A method in which a part of the component (c) is preliminarily kneaded with the component (a) or the component (b) and the preliminarily kneaded material is again melt kneaded together. A method in which the component (c) is supplied, and the component (a) is supplied and melt-kneaded into these compositions in a molten state from an intermediate port of the extruder, or the component (b) and the component (a) are supplied from the first feed port of the extruder. )
It is manufactured by various methods such as a method in which a part of the components is supplied, and the remaining components (a) and (c) are supplied from the intermediate feed port of the extruder to the melted composition and the remaining components are melt-kneaded. be able to. As these methods, for example, a single-screw extruder, a twin-screw extruder, a roll, a kneader, a Brabender plastograph, a hot-melt kneading method using a Banbury mixer and the like, among which a melt-kneading method using a twin-screw extruder is used. Most preferred. The melting and kneading temperature at this time is not particularly limited, but it can be arbitrarily selected usually from 200 to 350 ° C.

The resin composition of the present invention thus obtained can be prepared by various known methods, for example, injection molding,
It can be molded as a molded body of various parts by extrusion molding and hollow molding. These various parts include, for example, automobile parts, and specifically, exterior parts such as bumpers, fenders, door panels, various moldings, emblems, engine hoods, wheel caps, roofs, spoilers, various aero parts, and components such as interior parts. Suitable for interior parts such as instrument panel, console box, trim etc. Furthermore, it can be suitably used as an interior / exterior component of electric equipment, and specifically, various computers and their peripheral devices, other OA equipment, televisions, videos, cabinets for various disk players, chassis, trays, refrigerators and other components. Suitable for application.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto.

Polypropylene resin of component (a) used in Examples (a): Homo-polypropylene Melting point = 161 ° C., MFI = 2.1 PPE of component (b) used in Examples (b): 2,6 -Polyphenylene ether having reduced viscosity of 0.43 obtained by oxidative polymerization of xylenol Hydrogenated block copolymer of component (c) used in Examples (c-1): polystyrene-hydrogenated isoprene / butadiene copolymer Polymer (Isoprene / butadiene = 30
% By weight / 70% by weight, total vinyl bond amount: 76%)-has a polystyrene structure, a bonded styrene amount of 45%, a number average molecular weight of polystyrene of 20,000, and a total hydrogenation ratio of the isoprene / butadiene copolymerized portion of 98.3. % Of a hydrogenated block copolymer was synthesized, and this polymer was designated as (c-1).

(C-2): polystyrene-hydrogenated isoprene / butadiene copolymer (isoprene / butadiene = 70% by weight / 30% by weight, total vinyl bond amount 54)
%)-Having a polystyrene structure and a bound styrene content of 25
%, A hydrogenated block copolymer having a number average molecular weight of polystyrene of 16,000 and a total hydrogenation rate of isoprene / butadiene copolymer of 97.7% was synthesized.
2).

(C-3): polystyrene-hydrogenated isoprene / butadiene copolymer (isoprene / butadiene = 40% by weight / 60% by weight, total vinyl bond amount 52
%)-Having a polystyrene structure and an amount of bound styrene of 33
%, A number average molecular weight of polystyrene of 18,000, and a total hydrogenation ratio of isoprene / butadiene copolymer part of 98.9% was synthesized to obtain a hydrogenated block copolymer.
3).

(C-4): polystyrene-hydrogenated isoprene / butadiene copolymer (isoprene / butadiene = 50% by weight / 50% by weight, total vinyl bond amount 66)
%)-Polystyrene structure and the amount of bound styrene is 48
%, A hydrogenated block copolymer having a number average molecular weight of polystyrene of 21,000 and a total hydrogenation ratio of isoprene / butadiene copolymer of 96.5% was synthesized.
4).

(C-5): polystyrene-hydrogenated polyisoprene (isoprene / butadiene = 100% by weight / 0% by weight, total vinyl bond amount: 46%)-polystyrene structure, bonded styrene amount: 25% A hydrogenated block copolymer having a number average molecular weight of polystyrene of 16,000 and a hydrogenation ratio of the polyisoprene portion of 90.1% was synthesized, and this polymer was designated as (c-5).

(C-6): polystyrene-hydrogenated polybutadiene (isoprene / butadiene = 0% by weight)
/ 100% by weight, total vinyl bond amount 48%)-a hydrogenated block copolymer having a polystyrene structure, a bonded styrene amount of 33%, a polystyrene number average molecular weight of 19000, and a hydrogenation rate of a polybutadiene portion of 99.2%. A coalescence was synthesized, and this polymer was designated as (c-6).

(C-7): polystyrene-hydrogenated polybutadiene (isoprene / butadiene = 0% by weight)
/ 100% by weight, total vinyl bond amount 80%)-a hydrogenated block copolymer having a polystyrene structure, a bonded styrene amount of 44%, a polystyrene number average molecular weight of 20,000, and a hydrogenation rate of the polybutadiene portion of 99.7%. A coalescence was synthesized, and this polymer was designated as (c-7).

(C-8): polystyrene-hydrogenated polyisoprene (isoprene / butadiene = 100% by weight / 0% by weight, total vinyl bond content: 60%)-polystyrene structure, bound styrene content: 20% A hydrogenated block copolymer having a polystyrene number average molecular weight of 96,000 and a polyisoprene hydrogenation ratio of 88.6% was synthesized, and this polymer was designated as (c-8).

The properties of the obtained resin composition were determined by the following methods.

(1) Heat Resistance Test The heat distortion temperature (HDT) was measured under a load of 18.6 kg according to ASTM D648.

(2) Low-Temperature Impact Test According to ASTM D256, a notched Izod impact strength at −15 ° C. was measured on a 1/8 inch thick injection molded piece.

(3) Vibration Suppression Property (Loss Coefficient η) Using a two-channel fast Fourier transform apparatus, measurement was performed at a measurement temperature of 23 ° C. by a cantilever method using non-contact random vibration.

Examples 1 to 7 and Comparative Examples 1 to 6 A polypropylene resin, a polyphenylene ether resin and a hydrogenated block copolymer were blended according to the composition shown in Table 1.
Twin screw extruder with vent port set at 260-280 ° C (ZSK-25; WERNER & PFLEIDERE)
R, Germany) to obtain pellets.

The pellets are fed to a screw in-line type injection molding machine set at 240 to 280 ° C.
A test piece for an Izod impact test and a test piece for measuring a thermal deformation temperature were injection-molded at a mold temperature of 60 ° C. Further, a test piece having a thickness of 1/8 inch, a width of 0.5 inch and a length of 5 inch was injection molded as a test piece for measuring vibration damping performance. These test pieces were measured for the heat distortion temperature (HDT), the low-temperature Izod impact strength, and the vibration damping performance by the methods described above. Table 1 shows the results.
Put on.

[0059]

[Table 1]

From these results, as the hydrogenated block copolymer, at least one copolymer mainly composed of a vinyl aromatic compound was used.
Polymer block A, the weight ratio of isoprene and butadiene is 80/20 to 20/80, and 1,2-
When the total amount of the vinyl bond amount and the 3,4-vinyl bond amount is 5
By using a hydrogenated block copolymer obtained by hydrogenating a block copolymer of at least one isoprene and butadiene copolymer block B of 0 to 80%, vibration damping properties and low-temperature impact strength are obtained. And a resin composition having an excellent balance of heat distortion temperature.

Further, as a hydrogenated block copolymer outside the present invention, the polymer block B simply has a total amount of 50% of 1,2-vinyl bond and 3,4-vinyl bond of isoprene.
When a hydrogenated block copolymer composed of only at least one isoprene polymer block of ８０80% is used, the vibration control performance is excellent, but the low-temperature impact strength is extremely deteriorated. Further, as the hydrogenated block copolymer, the polymer block B is simply a 1,2-vinyl bond amount of butadiene of 50-8.
When using a hydrogenated block copolymer consisting of at least one butadiene polymer block of 0%,
Although the resin composition is excellent in low-temperature impact strength, the resin composition has poor vibration damping properties and a poor balance between vibration damping properties and low-temperature impact strength.

[0062]

The resin composition of the present invention comprises a polypropylene resin, a polyphenylene ether resin and a hydrogenated block copolymer.
Since the hydrogenated block copolymer having the specified structure is used, the heat resistance, low-temperature impact resistance and vibration damping performance of a resin composition containing a polypropylene resin and polyphenylene ether, which were difficult in the prior art, are improved.

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Claims (1)

(57) [Claims] 1. A resin composition comprising: (a) 5 to 95% by weight of a polypropylene resin, (b) 95 to 5% by weight of a polyphenylene ether resin, based on 100 parts by weight of the total of the components (a) and (b).
(C) the block copolymer has a weight ratio of at least one polymer block A mainly composed of a vinyl aromatic compound, isoprene and butadiene of 80/20 to 20/80, and 1,2-vinyl A hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising at least one copolymer block B of isoprene and butadiene having a total amount of the bond amount and the 3,4-vinyl bond amount of 50 to 80%. A resin composition having excellent vibration damping properties and low-temperature impact properties, characterized by comprising 1 to 30 parts by weight of a polymer.