JPH09183876A - Propylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene resin composition having low gloss and balanced mechanical strengths. SOLUTION: This resin composition is composed of (A) 55-95wt.% of a propylene polymer, (B) 1-10wt.% of a modified ethylene-α-olefin copolymer, (C) 1-10wt.% of a polyethylene-ethylene/butylene-polyethylene triblock copolymer and (D) 0-30wt.% of an inorganic filler.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a propylene resin composition having a low gloss and a good balance of mechanical strength.

[0002]

2. Description of the Related Art Propylene resin compositions are widely used for automobile parts such as bumpers, instrument panels, glove boxes, etc., because of their excellent mechanical strength, moldability and economy. Above all, automobile interior parts are required to have lower gloss in terms of design. In this case, attempts have conventionally been made to improve by adding a granular filler or adding a specific ethylene-propylene copolymer rubber.

[0003]

However, the addition of the particulate filler or the specific ethylene-propylene copolymer rubber has a small effect of reducing the gloss with respect to the addition amount. Therefore, in order to obtain low gloss, it is necessary to add a large amount of these components, but if a large amount of these components is added, the balance of other physical properties such as moldability and mechanical strength may be impaired.

[0004]

The inventors of the present invention have conducted various studies in order to solve the above-mentioned problems, and as a result, the specific propylene-based resin composition has a remarkably low gloss and balances mechanical strength. They found that they have the features and completed the present invention.

That is, the present invention provides (A) propylene polymer 55 to 95% by weight (B) modified ethylene-α-olefin copolymer 1-1
0% by weight (C) Polyethylene-ethylene / butylene-polyethylene triblock copolymer 1 to 10% by weight (D) Inorganic filler 0 to 30% by weight, which is a propylene resin composition.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. (A) Propylene-based polymer The propylene-based polymer blended in the propylene-based resin composition according to the present invention is, for example, a propylene homopolymer, a block copolymer of ethylene containing propylene as a main component and / or an α-olefin. It is selected from a polymer and a random copolymer mainly composed of propylene and ethylene and / or α-olefin. These are used alone or in combination. Further, to the propylene-based polymer of the present invention, an ethylene-propylene copolymer rubber may be added thereto in a range that does not impair the mechanical properties, that is, 40% by weight or less.

The melt flow rate (hereinafter, also referred to as MFR) of this propylene-based polymer (measured under the condition 14 according to the method of JIS K7210) is preferably 1.0 to 150.
g / 10 minutes, particularly preferably 3.0 to 150 g /
10 minutes. When a propylene-based polymer having an MFR of less than 1.0 g / 10 minutes is used, the moldability of the composition and the appearance of the molded product may be deteriorated, and conversely, the MFR is 150 g.
If a propylene-based polymer exceeding / 10 minutes is used, the mechanical strength of the resulting composition tends to decrease.

Among the propylene polymers of the present invention, a propylene-ethylene block copolymer containing a crystalline polypropylene portion (component a) and an ethylene-propylene random copolymer portion (component b), wherein The component accounts for 60 to 95% by weight of the whole block copolymer, and its MFR is 5 to 200 g / 10 minutes, preferably 20 to 1
50 g / 10 minutes and a density of 0.9070 g / cm ³ or more, preferably 0.99075 g / cm ³ or more, and b
The component accounts for 5 to 40% by weight, preferably 5 to 30% by weight of the whole block copolymer, and its ethylene content is 20 to
A block copolymer of 80% by weight, preferably 25 to 75% by weight, is preferable because it has a good balance of mechanical strength. Here, the content of component b is 200 g for a 1 g sample.
It can be calculated by immersing it in boiling xylene for 1 hour to dissolve it, then cooling it to room temperature, and filtering back and drying the solid phase deposited thereby, and calculating back by the solid phase weight. Further, the ethylene content can be measured by an infrared spectrum analysis method or the like.

The above-mentioned propylene-ethylene block copolymer can be produced by controlling the conditions by a generally known method, and those which are commercially available and satisfy the above requirements can be used. Further, as an arbitrary copolymer monomer component other than the ethylene component and the propylene component, a range that does not significantly impair the effects of the invention (for example,
15% by weight or less, preferably 10% by weight or less), such as 1-butene, 3-methyl-1-butene, 4-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-pentene. It may be a copolymer of α-olefin.

(B) Modified Ethylene-α-Olefin Copolymer The modified ethylene-α-olefin copolymer of the present invention comprises an unmodified ethylene-α-olefin copolymer in the presence of an organic peroxide. It is obtained by heat treatment with a saturated hydroxy compound or an unsaturated carboxy compound. Specifically, for example, an amorphous ethylene-α-olefin copolymer, an organic peroxide and an unsaturated hydroxy compound or an unsaturated carboxy compound are mixed in advance with a Henschel mixer or the like, and then a usual twin-screw extruder or single-screw extruder is used. It can be adjusted by heating and kneading with a kneader such as a machine or a Banbury mixer. The temperature during kneading depends on the type of resin and organic peroxide used, but is generally 100 ° C.
３００300 ° C.

Ethylene-α-which can be used here
Examples of the olefin copolymer include ethylene among propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-butene, 4-methyl-1-pentene, 1-hexene and 1-pentene. It is a copolymer with one or more kinds of α-olefins, and an amorphous ethylene-propylene copolymer is particularly preferable because it has a great effect of improving gloss. The ethylene content in the ethylene-α-olefin copolymer is 2
0 to 60% by weight is preferable, more preferably 20 to 4
0% by weight. When the ethylene content exceeds the above range,
The effect of improving gloss is inferior, which is not preferable.

Examples of the organic peroxide include dibenzoyl peroxide, p-chlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide,
t-Butyl cumyl peroxide, 1,3-bis (t-
Butylperoxy) isopropylbenzene, 2,5-bis (t-butylperoxy) -2,5-dimethylhexene, 2,5-bis (t-butylperoxy) -2,5-dimethyl-3-hexyne, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-
Butyl peroxybenzoate and the like can be used, and these may be diluted with an inert substance such as a plasticizer, calcium carbonate, and white carbon. The blending amount of the organic peroxide is 0.01 to 2 parts by weight with respect to 100 parts by weight of the ethylene-α-olefin copolymer,
It is preferably 1 part by weight or less in order to prevent significant crosslinking of the ethylene-α-olefin copolymer.

The unsaturated hydroxy compound used as a modifier is a compound having at least one unsaturated bond in the molecule and containing a hydroxy group, such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, Hydroxypropyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, glycerol mono or diacrylate, glycerol mono or dimethacrylate, trimethylolpropane mono or diacrylate, trimethylolpropane mono or di Methacrylate, ethylene glycol monoallyl ether, propylene glycol Over monoallyl ether, polyethylene glycol monoallyl ether, polypropylene glycol monoallyl ether, ortho, meta, or para-hydroxy styrene, and mixtures thereof. The blending amount of these unsaturated hydroxy compounds in the modified ethylene-α-olefin copolymer is 0.1 to 100 parts by weight with respect to 100 parts by weight of the ethylene-α-olefin copolymer.
It is 10 parts by weight, preferably 0.1 to 4 parts by weight. Outside of the above range, the physical properties and appearance of the molded product are inferior, which is not preferable.

It is essential that the content of hydroxy groups in the unsaturated hydroxy compound is 0.01% by weight or more in terms of hydroxyethyl methacrylate, based on the total amount of all components in the composition, and is below the above range. And the gloss is not sufficiently reduced, which is not preferable. The value of the hydroxy group content can be measured by an infrared spectrum analysis method or the like.

The unsaturated carboxy compound used as a modifier is a compound having at least one unsaturated bond in the molecule and containing a carboxyl group, and includes maleic anhydride, itaconic anhydride and citraconic anhydride. , Fumaric anhydride, endic anhydride, at most 1 carbon
Examples thereof include alkenyl succinic anhydride having a double bond at the terminal of 8 and alkadienyl succinic anhydride having a double bond at the terminal having at most 18 carbon atoms. The amount of these unsaturated carboxy compounds in the modified ethylene-α-olefin copolymer to be blended is 0.1 to 10 parts by weight, preferably 0.1 to 4 parts by weight, relative to 100 parts by weight of the ethylene-α-olefin copolymer. Parts by weight. Outside of the above range, the physical properties and appearance of the molded product are inferior, which is undesirable.

The content of the carboxyl group in the unsaturated carboxy compound is preferably 0.01% by weight or more in terms of maleic anhydride, based on the total amount of all components in the composition,
Below this range, the gloss is not sufficiently reduced, which is not preferable. The value of the carboxyl group content can be measured by an infrared spectrum analysis method or the like.

(C) Polyethylene-ethylene / butylene-polyethylene triblock copolymer The polyethylene-ethylene / butylene-polyethylene triblock copolymer of the present invention (hereinafter sometimes referred to as CEBC) has ethylene at the center of the molecule. / Butylene blocks are located, and crystalline polyethylene blocks are located on both sides of the blocks. The content of polyethylene block in CEBC is 15 to 40% by weight. If the content of the polyethylene block is less than 15% by weight, the rigidity, heat resistance and surface hardness of the propylene resin composition obtained will decrease. If it exceeds 40% by weight, the low temperature impact resistance of the propylene-based resin composition is lowered.

This CEBC melt flow rate (JI
(Measured under the condition 14 according to the method of SK7210) is preferably 0.5 to 70 g / 10 minutes. MFR is 0.5g
If CEBC of less than / 10 minutes is used, poor dispersion may occur and impact resistance of the composition may be deteriorated.
However, when CEBC of more than 70 g / 10 minutes is used, the rigidity and heat resistance of the composition tend to be lowered.

The polyethylene-ethylene / butylene-polyethylene triblock copolymer of the present invention can be produced by hydrogenating a triblock copolymer of 1,4-polymer polybutadiene and 1,2-polymer polybutadiene. Is. First, a method of producing such a butadiene diblock copolymer, forming a triblock copolymer using a coupling agent, and then hydrogenating the same, and a method of using the bifunctional initiator to prepare the triblock copolymer. There is a method of directly polymerizing and then hydrogenating. In any case, a diblock copolymer is produced, but this proportion is preferably less than 40% by weight of the whole. This is because if it exceeds 40% by weight, it will dissolve in the propylene-based polymer and the rigidity and surface hardness will decrease.

(D) Inorganic Filler In addition to the above-mentioned components, the propylene-based resin composition according to the present invention is widely used in the field of general synthetic resin or rubber for the purpose of increasing rigidity and heat resistance. Fillers can be included. As such an inorganic filler,
For example, oxides of metals such as aluminum, copper, iron, lead, nickel, magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony and titanium, hydrates (hydroxides), sulfates, carbonates thereof. , Compounds such as silicates, double salts thereof, and mixtures thereof.

Of these inorganic fillers, powdery ones have a diameter of 30 μm or less (more preferably 15 μm or less).
Are preferred. For fibrous materials, the diameter is 0.1
.About.20 .mu.m (more preferably 0.1 to 15 .mu.m) and a length of 1.0 to 150 .mu.m (more preferably 10 .mu.m or less) are preferable. Among these inorganic fillers, talc, mica, clay, wollastonite, potassium titanate, calcium carbonate and the like are preferable, and among them, surface-treated talc improves the mechanical strength of the molded product and the molded product appearance. Therefore, it is preferable. The surface treatment agent is preferably a silane compound, for example, vinylethoxysilane, 2-aminopropyltriethoxysilane, 2-glycidoxypropylmethoxysilane, a silazane compound, for example, dimethylpolysiloxysilazane, a titanate compound, and the like. Modified polypropylene, such as maleic anhydride modified polypropylene, can be used.

(E) Other Additives The propylene resin composition according to the present invention further comprises an ultraviolet absorber, an antioxidant and a weather resistance stabilizer which are generally used in the field of polyolefin resins, particularly polypropylene resins. Additives such as agents, plasticizers, lubricants, antistatic agents, colorants, pigments, flame retardants, and dispersants can be added within a range that does not substantially impair the physical properties of each composition or synthetic resin.

(F) Composition Ratio The resin composition according to the present invention comprises the above-mentioned propylene polymer (A), modified ethylene-α-olefin copolymer (B), polyethylene-ethylene / butylene-polyethylene triblock copolymer. It is composed of a polymer (C) and, if necessary, an inorganic filler (D).

The proportion of the propylene polymer (A) in the composition of the present invention is 55 to 9 based on the total weight of the composition.
5% by weight, preferably 60 to 90% by weight,
Particularly preferably, it is 65 to 90% by weight. If the proportion of the propylene-based polymer (A) in the composition is less than 55% by weight, the rigidity of the obtained molded article is lowered, which is not preferable. On the contrary, if it exceeds 95% by weight, impact resistance is deteriorated, which is not preferable. .

The proportion of the modified ethylene-α-olefin copolymer (B) in the composition of the present invention is 1 to 10% by weight, preferably 1 to 5% by weight, based on the total weight of the composition. And particularly preferably 1 to 3% by weight. If the proportion of the modified ethylene-α-olefin copolymer (B) in the composition is less than 1% by weight, the effect of lowering the gloss of the obtained molded product is poor, and conversely if it exceeds 10% by weight, the molded product obtained. The mechanical properties and the appearance of the molded product are inferior, which is not preferable.

The proportion of the polyethylene-ethylene / butylene-polyethylene triblock copolymer (C) in the composition according to the present invention is 1 to 10% by weight, preferably 1 to 5%, based on the total weight of the composition. % By weight. When the proportion of the polyethylene-ethylene / butylene-polyethylene triblock copolymer (C) in the composition is less than 1% by weight, the resulting molded article has poor impact resistance, and conversely, when it exceeds 10% by weight, molding is obtained. It is not preferable because the product has poor rigidity or heat resistance.

When the inorganic filler (D) is added to the composition according to the present invention, the mixing ratio is 30% by weight or less based on the total weight of the composition, and in order to further improve heat resistance and rigidity, 1 to 25% by weight is preferable. Inorganic filler (D)
If the blending amount exceeds 30% by weight, not only the impact resistance decreases but also the weight becomes heavy, which is not preferable.

When the resin composition according to the present invention is produced,
Each composition component may be mixed uniformly, a part of the composition component is mixed in advance to produce a so-called masterbatch,
You may mix this masterbatch and the remaining composition component.

To produce the resin composition according to the present invention,
A method generally used in the field of synthetic resins may be applied. Examples of the mixing method include a dry blending method using a mixer such as a Henschel mixer, and a melt kneading method using a mixer such as a roll mill, a screw type extruder, a kneader, a Banbury mixer, and a Brabender Plastograph. At this time, a more uniform composition can be obtained by dry-blending the composition components in advance and further melt-kneading the obtained mixture. The composition is in the form of pellets,
It is preferable in terms of handling when producing a molded product described below.

The resin composition according to the present invention can be formed into a molded product by a molding method such as an injection molding method, a press molding method, an extrusion molding method or the like which is generally used in the field of thermoplastic resins. It is necessary to carry out at a temperature higher than the melting point of the thermoplastic resin used in both the melt kneading and the molding. However, if it is carried out at an excessively high temperature, the polymer material used may be thermally decomposed. The melt-kneading temperature and the molding temperature cannot be unconditionally specified depending on the type and composition ratio of each material, but are generally 180 to 300 ° C., preferably 170 to 300 ° C.
The temperature is 250 ° C, more preferably 160 to 190 ° C.

[0031]

EXAMPLES The present invention will be described in more detail with reference to experimental examples. The evaluation method performed here is as follows.

"Gloss" The gloss is 240 mm in length and 80 in width.
of the flat plate test piece having a shape of mm and a thickness of 3 mm, and a gloss (60
°) was measured with a gloss meter. The molding was performed using an IS-150EN type injection molding machine manufactured by Toshiba Machine, and the molding conditions were 2
It was carried out at 20 ° C.

"Bending elastic modulus" The bending elastic modulus is JIS-K.
It measured based on 7203. The measurement temperature is 23 ° C., and the measurement speed is 30 mm / min.

"Izod impact value" The Izod impact value is J
It was measured according to IS-K7110. The notch is a molded notch and the measurement temperature is 23 ° C.

"Heat resistance" Heat resistance (HDT) is JIS-
It measured based on K7207. Bending stress is 4.6 kg
f / cm ³ .

The following was used as each component. (A) Propylene-based polymer (A-1): MFR 52 g / 10 minutes, density 0.9085
g / cm ³ or more crystalline polypropylene part (a component) 8
Propylene-containing 0% by weight and 20% by weight of an ethylene-propylene random copolymer portion (component b) having an ethylene content of 50% by weight, and having a total MFR of 20 g / 10 min.
Ethylene block copolymer. (A-2): MFR 38 g / 10 minutes, density 0.9085
g / cm ³ or more crystalline polypropylene part (a component) 9
A propylene-ethylene block copolymer containing 1% by weight and 8% by weight of an ethylene-propylene random copolymer portion (component b) having an ethylene content of 50% by weight, and having a total MFR of 20 g / 10 min.

(B) Modified or unmodified ethylene-α-olefin copolymer (B-1): Maleic anhydride addition amount 0.8 wt%, ethylene content 78 wt%, MFR 2.5 g / 10 min modified amorphous Ethylene-propylene copolymer. (B-2): ethylene content 82% by weight, MFR 1.8 g
/ 10 min amorphous ethylene-propylene copolymer. (B-3): ethylene content 82% by weight, MFR 0.5 g
/ 10 min amorphous ethylene-propylene copolymer.

(C) Polyethylene-ethylene / butylene-polyethylene triblock copolymer (C-1): 6200P (MFR manufactured by Nippon Synthetic Rubber Co., Ltd.)
2.5g / 10 minutes)

(D) Inorganic filler (D-1): Talc having a total length of 15 μm or less, an average particle size of 1 μm and an average aspect ratio of 5. In addition, in order to impart a surface modifying effect, maleic anhydride modified polypropylene (ER320P manufactured by Nippon Polyolefin Co., Ltd.)
Was added to the composition at 0.2 phr, along with other ingredients during mixing.

Examples 1 to 9 and Comparative Examples 1 to 7 Compositions shown in Tables 1 and 2 were mixed by a Henschel mixer at 500 rpm for 2 minutes, and a 30 mmφ co-directional twin-screw extruder [KTX-KTX- 30] at 160 ° C, 3
The mixture was kneaded under the condition of 50 rpm, cooled with water, and pelletized. The obtained pellets were injection molded and evaluated.
The evaluation results are shown in Tables 1-2.

[0041]

[Table 1]

[0042]

[Table 2]

As shown in Table 1, the resin compositions having the compositions shown in Examples 1 to 9 have gloss and good mechanical strength balance. On the other hand, in all of Comparative Examples 1 to 7, the gloss and the balance of mechanical strength were partially or entirely insufficient.

[0044]

EFFECTS OF THE INVENTION The propylene resin composition of the present invention contains a modified ethylene-α-olefin copolymer, a polyethylene-ethylene / butylene-polyethylene triblock copolymer, and an inorganic filler in the composition to reduce the Since it is glossy and has a good balance of mechanical properties, it has excellent applicability as a material for automobile interior parts such as instrument panels, trims, and glove boxes.

Claims (1)

[Claims] 1. (A) Propylene-based polymer 55 to 95% by weight (B) Modified ethylene-α-olefin copolymer 1-1
0% by weight (C) polyethylene-ethylene / butylene-polyethylene triblock copolymer 1 to 10% by weight (D) inorganic filler 0 to 30% by weight, a propylene-based resin composition.