JPH10130398A - Injection molded form of propylene-based resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molded form excellent in impact resistance, rigidity, tensile elongation and surface gloss. SOLUTION: This molded form >=81% in surface gloss is obtained by injection molding of a composition prepared by compounding 100 pts.wt. of a crystalline polypropylene-based resin 0.5-100g/10min in melt flow rate (MFR), >=0.906g/m<3> in density and >=96 in isotactic pentad fraction with 3-40 pts.wt. of an ethylene-α-olefin copolymer containing 20-65wt.% of a 4-8C α-olefin, 0.6-40g/10min in MFR and 0.85-0.90 in density, polymerized in the presence of a metallocence catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propylene resin injection molded article having excellent impact resistance, rigidity, tensile elongation and surface gloss.

[0002]

2. Description of the Related Art In general, polypropylene resin has moldability,
Since it is excellent in rigidity, gloss, hygiene and heat resistance, it is subjected to various molding processes, polystyrene (PS),
Like acrylonitrile-butadiene-styrene (ABS) resin and the like, it is widely used for various uses such as daily necessities, food containers, home electric appliances, and automobile parts. Polypropylene resins have excellent rigidity, heat resistance and surface gloss due to their crystallinity, but have the disadvantage of low impact strength, especially low-temperature impact resistance. Conventionally, polypropylene, polyethylene, isoprene rubber, butadiene rubber and ethylene
A composition in which propylene copolymer rubber and the like are mixed has been proposed. However, when these compositions are used as molding materials for injection molding, the surface gloss is reduced as compared with propylene homopolymers, and therefore, particularly for products that emphasize surface appearance, improvement is strongly desired. . Examples of such a method for improving the surface gloss include a method of reducing the amount of polyethylene and other rubber to be compounded, and a method of reducing the ethylene content when a polypropylene resin which is a copolymer with ethylene is used. Even if the above method is adopted, the low-temperature impact strength is reduced and the range of use is limited. Therefore, to increase the gloss, there are a method of using a polypropylene having a low molecular weight, a method of increasing the crystallinity of the polypropylene, and the like. However, these methods do not provide a sufficiently satisfactory product with reduced impact strength, tensile elongation, and the like. .

[0003]

Under these circumstances, the present inventors have conducted intensive studies to improve the surface gloss of a propylene-based resin injection-molded article, and as a result, have obtained a specific catalyst. By mixing an ethylene / α-olefin copolymer with a propylene-based resin, it has been found that impact resistance, rigidity, tensile elongation and surface gloss are excellent, and the present invention has been accomplished.

[0004]

That is, the propylene resin injection molded article of the present invention has a melt flow rate of 0.5.
A crystalline polypropylene resin having a density of 0.906 g / cm ³ or more and an isotactic pentad fraction of 96 or more, and an α-olefin having 4 to 8 carbon atoms per 100 parts by weight of the resin. In a proportion of 20 to 65% by weight and a melt flow rate (230 ° C., 2.16%).
kg) is 0.5 to 40 g / min, and the density is 0.85 to 0.9.
The gloss obtained by injection-molding a propylene-based resin composition which is 0 g / cm ³ and ³ to 40 parts by weight of an ethylene / α-olefin copolymer polymerized with a metallocene catalyst is 81% or more. It is characterized by having.

[0005]

DETAILED DESCRIPTION OF THE INVENTION

[I] Propylene resin composition (1) Component (A) Component A Polypropylene resin (Component A) used in the present invention
Has a density of 0.906 g / cm ³ or more, preferably 0.907 g / cm ³ , measured according to JIS-K6758.
cm ³ or more, particularly preferably at 0.908 g / cm ³ or more, a melt flow rate (MFR, 230 ℃, 2.
16 kg load) 0.5 to 100 g / min, preferably 1
To 80 g / min, more preferably 2 to 50 g / min,
Further, the isotactic pentad shows a value of 96 or more, preferably 97 or more, particularly preferably 98 or more. If the MFR is higher than the above range, the impact strength of the product is insufficient, and if the MFR is lower than the above range, poor flow during injection molding is not preferable. If the value of the isotactic pentad fraction is too low, the rigidity becomes insufficient, which is not preferable.

The above-mentioned polypropylene resin includes propylene homopolymer, propylene, ethylene, 1-
Block copolymers with α-olefins such as butene, 1-pentene, 1-hexene and 4-methyl-pentene-1 and random copolymers are included. As the propylene / α-olefin block copolymer, specifically, the propylene / ethylene block copolymer, a crystalline polypropylene part (component (a)) and an ethylene / propylene random copolymer (b)
Component) and a propylene / ethylene block copolymer. The component a is 80 to 95% by weight in the propylene / ethylene block copolymer in consideration of the balance between impact resistance and rigidity.
Having an MFR of 5 to 100 g / min and a density of 0.9.
06 or more, the isotactic pentalid fraction is 96 or more, and the component b occupies 5 to 20% by weight of the propylene / ethylene block copolymer, and the ethylene content is 3% or less.
It is preferable that the propylene / ethylene block copolymer has a polymerization MFR of 1 to 80 g / min, from 0 to 70% by weight and an MFR of 0.01 to 1 g / min. The isotactic pentad fraction is an isotactic fraction in pentad units in a polypropylene molecular chain measured using ¹³ C-NMR (nuclear magnetic resonance method). For actual ¹³ C-NMR measurement, 270 M of FT-NMR was used.
Hz.

(B) Component B The ethylene / α-olefin copolymer (Component B) used in the present invention contains α-olefin having 4 to 8, preferably 6 to 8 carbon atoms in an amount of 20 to 65% by weight, preferably 20 to 60% by weight, particularly preferably 20 to 55% by weight,
Further, the melt flow rate (MFR, 230 ° C., 2.16
kg load) is 0.5 to 40 g / min, particularly preferably 1 to 40 g / min.
40 g / min, a density of 0.85 to 0.90 g / cm ³ , preferably 0.85 to 0.89 g / cm ³ , particularly preferably 0.85 to 0.88 g / cm ³ , and a metallocene catalyst It is polymerized by. Examples of the α-olefin to be copolymerized with ethylene include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and the like. Among them, 1-butene, 1
-Pentene, 1-hexene, 1-heptene and 1-octene are preferred, and 1-hexene and 1-octene are particularly preferred. Examples of the polymerization method of the ethylene / α-olefin copolymer include a gas phase polymerization method, a solution polymerization method, a slurry polymerization method, and a high pressure polymerization method.

As the metallocene polymerization catalyst, a catalyst called a metallocene catalyst is used. Specifically, alumoxane may not be contained, but a catalyst obtained by combining a metallocene compound and alumoxane, that is, a so-called Kaminsky catalyst, is described in JP-A-58-19309 and JP-A-59-19309. -95292, JP-A-60-35005, JP-A-60-35006, JP-A-60-35007, JP-A-60-35008,
JP-A-60-35009 and JP-A-3-1630088, European Patent Application Publication No. 420436,
Mention may be made of the catalysts described by U.S. Pat. No. 5,055,428, and particularly preferably by WO 91/04257.

Above all, it is desirable to use the ethylene / α-olefin copolymer of the component B having an ethylene three-chain fraction of 55 to 70% as measured by ¹³ C-NMR. When the content of the α-olefin is less than the above range, the impact strength and gloss are inferior. On the other hand, when the content exceeds the above range, not only the rigidity is reduced but also the shape of the polymer is maintained in a pellet form. Is difficult, and productivity is remarkably reduced in the production of the resin composition. If the MFR is less than the above, gloss and tensile elongation are inferior, and if it exceeds the above range, the impact strength is inferior. If the density is less than the above range, it is difficult to form a pellet, and if the density exceeds the above range, the impact strength and gloss are poor and unsuitable. Here, MFR is JIS-K72
10. The density is a value measured according to JIS-K7112. When an ethylene / α-olefin copolymer not polymerized with the above metallocene catalyst is used, the gloss is remarkably reduced. Further, the above-mentioned ethylene / α-olefin copolymer polymerized with a metallocene catalyst (component B)
Are generally 0 to 2 in the measurement of crystallinity by X-rays.
Exhibiting a crystallinity of 2%, preferably 0-20%,
The flexural modulus according to JIS-K7106 is generally 500k
g / cm ² or less, preferably 400 kg / cm ² or less.

(C) Additional Components In the present invention, in addition to these essential components, other additional components can be blended within a range that does not significantly impair the effects of the present invention. Additional components include crystallization nucleating agents, other lubricants such as fatty acid amides and silicone oils, antistatic agents such as glycerin esters of fatty acids and amines or amides, molecular weight regulators such as peroxides, foaming agents, and organic agents. Or inorganic pigments, dispersants, light stabilizers, UV absorbers, antioxidants, neutralizers, antacids, phosphorus, nitrogen, silicon, halogen flame retardants, metal deactivators , A surfactant, an antibacterial agent and the like.

Examples of the crystallization nucleating agent include inorganic substances such as talc, metal salts of aromatic carboxylic acids, metal salts of aromatic phosphates, metal salts of sorbitol derivatives and rosin. Among them, preferred are ALsalt-pt-butyl-benzoate, sodium benzoate, and phosphoric acid 2,2.
2'-methylenebis (4,6-di-t-butylphenyl) sodium, 1,2,3,4-dibenzylidene sorbitol, 1,2,3,4-bis (paramethylbenzylidene) sorbitol, 1,2,2 Metal salts (lithium, sodium, potassium, magnesium salts) of 3,4-bis (paraethylbenzylidene) sorbitol, 1,2,3,4-bis (parachlorobenzylidene) sorbitol and rosin can be exemplified.

Among the above-mentioned flame retardants, tetrabromobisphenol S bis (2,3-dibromophenyl ether), tetrabromobisphenol S, tetrabromobisphenol A bis (2,3-dibromophenyl ether), tetrabromobisphenol A bis (Allyl ether), tetrabromobisphenol A butyl ether oligomer, tetrabromobisphenol A, 1,2 bis (pentabromophenyl) ethane, decabromodiphenyl oxide, tris (2,3-dibromopropyl)
Isocyanurate, ethylene-bis (5,6-dibromonorbornane-2,3-dicarboximide), 1,2-
It is preferable to use bis (tetrabromophthalimide) ethane or the like.

As the antibacterial agent, any of an organic type and an inorganic type may be used. Examples of organic compounds include chlorine compounds, phenol compounds, imidazole compounds, thiazole compounds, and quaternary ammonium compounds. Examples of inorganic systems include
Examples of holding and containing metals such as silver, zinc and the like include zeolite, apatite, silica alumina, ceramic, zirconium phosphate, silica gel, hydroxyapatite, calcium silicate and the like.

In the present invention, an inorganic filler can be used in addition to the above components. The inorganic filler is 1 to 70 parts by weight, preferably 5 to 5 parts by weight based on 100 parts by weight of the total amount of the propylene resin and the ethylene / α-olefin copolymer.
It can be added in the range of 50 parts by weight. The rigidity can be imparted to the injection molded article obtained by adding the inorganic filler. As the inorganic filler, talc, barium sulfate, clay, silica, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide,
Glass fibers, whiskers and the like can be mentioned.

(2) Production of propylene resin composition The propylene resin composition comprising these components used in the present invention can be produced by a usual method. For example, the above component A, component B, and other additional components as needed are added to a powder of a polypropylene polymer, and the mixture is stirred and mixed with a Henschel mixer, melt-kneaded with an extruder, extruded, and pelletized. And Thereafter, the pellets can be obtained by molding an intended injection molded body using an injection molding machine.

[II] Injection molding The propylene-based resin injection-molded article of the present invention is obtained by injection-molding the propylene-based resin composition. The injection molding can be carried out in the same manner as in a normal injection molding method of a propylene-based resin.

[III] Injection molded article A polypropylene resin having the above-mentioned specific properties and ethylene / α
-The propylene resin injection molded article of the present invention obtained by injection molding a propylene resin composition containing an olefin copolymer preferably has an impact resistance of generally 3
２６26 kg / cm ² , preferably 3-20 kg / cm ²
While having an Izod impact strength of 8,000 kg / cm ² or more, preferably 13,00 kg / cm ² or more.
The flexural modulus and tensile elongation of 0 kg / cm ² or more are generally 20% or more, preferably 30% or more, and the surface gloss is 81%.
As described above, it is possible to obtain even those having physical properties of preferably 83% or more. Therefore, the polypropylene resin injection molded article of the present invention is superior in gloss and rigidity to conventional products.
Products with good impact strength balance can be obtained.

The injection-molded article of the present invention is used as a rice cooker, a vacuum cleaner, a washing machine, a refrigerator, a fan, an air conditioner, and other home electric parts, a dressing table, a ventilation fan, a toilet seat, a toilet lid, and accessories. Equipment parts for housing equipment, such as housings for equipment, food, cosmetics, detergents, chemical containers for insecticides, etc., caps for various sprays, stationery, accessories,
There are toys. Among these, preferable injection-molded articles include home electric parts, housing equipment parts, clothing, and storage containers (clothes boxes) for daily necessities. Particularly preferred are housing equipment parts such as toilet seats, toilet lids, and housings for equipment used as accessories.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Production of Propylene Homopolymer (Component A) After sufficiently replacing the inside of a 200-liter stirred autoclave with propylene, 60 liters of dehydrated and deoxygenated n-heptane were introduced, and the catalyst component magnesium chloride was added. 3.0 g of a supported titanium catalyst, 15.0 g of triethylaluminum (Al (C ₂ H ₅ ) ₃ ), and tert-butylmethyldimethoxysilane (t-C ₄ H ₉ ) as a third component
4.3 g of SiCH ₃ (OCH ₃ ) ₂ ) were introduced at a temperature of 70 ° C. under a propylene atmosphere. Next, propylene was introduced at a feed rate of 9 kg / hour, and after 240 minutes had elapsed, the introduction of the propylene was stopped. The molecular weight was adjusted while keeping the hydrogen concentration constant. The slurry thus obtained was filtered and dried, and the MFR (230
° C, 2.16 kg) 10 g / 10 min, density 0.90
88 g / cm ³ , isotactic pentad fraction 97
Was obtained as a powdered propylene homopolymer (component A).

Production of propylene resin composition 1-octene content 33% by weight ( ^13C -NMR method) based on 100 parts by weight of the propylene homopolymer (component A),
An ethylene / 1-octene copolymer (component B) having a MFR (230 ° C., 2.16 kg) of 11 g / 10 minutes and a density of 0.87 g / cm ³ , produced by a solution polymerization method using a metallocene catalyst, at 5 wt. Parts, as an additional component, 0.05 parts by weight of calcium stearate, 0.1 parts by weight of pentaerythyl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], tris (2, After blending 0.1 part by weight of 4-di-t-butylphenyl) phosphite with a Henschel mixer,
Using a 0 mmφ extruder, the composition was melt-kneaded and extruded at 240 ° C. to obtain a pellet-shaped composition.

Injection molding Using the obtained pellet-shaped composition, a test piece for measuring gloss (2 × 80 × 120 mmt), a flexural modulus and a test piece for measuring Izod impact strength were measured with an injection molding machine at a resin temperature. Injection molding was performed at 240 ° C. and a mold cooling temperature of 40 ° C., respectively. The measurement of each test piece was performed in accordance with (1) gloss JIS-Z8741 (2) flexural modulus JIS-K7203 (3) Izod impact strength JIS-K7110 (4) tensile elongation JIS-K7113. The tensile elongation was measured at a tensile speed of 50 mm / min after preparing a JIS No. 2 tensile test piece from the gloss test sheet test piece and adjusting the condition. Table 2 shows the results.

Example 2 In the production of the propylene resin composition of Example 1, sodium 2,2'-methylenebis (4,6-di-t-butylphenyl) phosphate was further added as an additional component. Performed in a similar manner to 1. Table 2 shows the results.

Example 3 The additional component 2,2'-methylenebis (4,6-di-t-butylphenyl) sodium phosphate of Example 2 was
The procedure was performed in the same manner as in Example 1, except that 3,2,4-di- (p-methylbenzylidene) -sorbitol was used. Table 2 shows the results.

Example 4 The procedure of Example 1 was repeated except that the amount of Component B was changed from 5 parts by weight to 15 parts by weight. Table 2 shows the results.
Shown in

Comparative Examples 1 to 3 The amount of component B in Example 1 was 0 part by weight (Comparative Example 1), and 5 parts by weight of a vanadium catalyst-based ethylene / propylene copolymer (Nippon Synthetic Rubber: EP02P) was used. Comparative Example 2) and 15 parts by weight (Comparative Example 3) were carried out in the same manner as in Example 1. Table 3 shows the results.

Example 5 Example 5 was carried out in the same manner as in Example 3 except that the component A in Example 3 was changed to a propylene / ethylene block copolymer (MFR: 10 g / 10 min) produced by the following method. Table 2 shows the results. Production of propylene / ethylene block copolymer (component A)
After thoroughly replacing the granulation content volume of 200 liter stirred autoclave with propylene, was introduced n- heptane 60 liters of dehydrated and deoxygenated, magnesium chloride-supported titanium catalyst 3.0g of the catalyst component, triethyl aluminum (Al _{(C 2 H 5) 3)} 15.0g, and tert-butyl methyl dimethoxy silane as the third component _(t-C 4 _{H 9}
4.3 g of SiCH ₃ (OCH ₃ ) ₂ ) were introduced at a temperature of 70 ° C. under a propylene atmosphere. The first-stage polymerization was started by heating the autoclave to a temperature of 75 ° C. and then introducing propylene at a feed rate of 9 kg / hour while maintaining the hydrogen concentration at 13%. After 228 minutes, the introduction of propylene was stopped and the polymerization was continued at a temperature of 75 ° C. for 90 minutes. 0.2 kg of propylene in the gas phase
/ Cm ² G. Next, 4.9 g of n-butanol was added, and the temperature of the autoclave was lowered to a temperature of 60 ° C.
Per hour, at a feed rate of 1.72 kg / hour of ethylene for 53 minutes. The slurry thus obtained was filtered and dried to produce a powdery propylene / ethylene block copolymer. Table 1 shows the measurement results of the physical properties of the copolymer.

Example 6 Component B of Example 5 was replaced with a 1-hexene content of 23% by weight ( ^13C
-NMR method), MFR (230 ° C, 2.16 kg) 27
The procedure was carried out in the same manner as in Example 5 except that the ethylene / 1-hexene copolymer produced by high-pressure polymerization using a metallocene catalyst and having a density of 0.89 g / cm ³ and g / 10 minutes was used.
Table 2 shows the results.

Example 7 Component B of Example 5 was prepared by adding 1-butene content of 22% by weight ( ¹³ C-
NMR method), MFR (230 ° C., 2.16 kg) 50 g
Example 10 was carried out in the same manner as in Example 5 except that an ethylene / 1-butene copolymer produced by a high-pressure polymerization method using a metallocene catalyst and having a density of 0.90 g / cm ³ and a density of 0.90 g / cm ³ was used. Table 2 shows the results.

Comparative Examples 4 to 7 0 parts by weight of the component B of Example 5 (Comparative Example 4), the propylene content of the vanadium catalyst system was 26% by weight, the density was 0.86, and the MFR was 3.0 g / 10 min. 5 parts by weight of ethylene-propylene copolymer (manufactured by Japan Synthetic Rubber: EP02P) (Comparative Example 5), butene content 19% by weight, density 0.8
9, 5 parts by weight (comparative example 6) of an ethylene / butene copolymer having an MFR of 6.2 g / 10 min (A4090 manufactured by Mitsui Petrochemical Co., Ltd.), an ethylene content of 34% by weight, and a density of 0.86 g
/ Cm ^3, MFR of 0.3 propylene-ethylene copolymer (Mitsui Petrochemical Co., Ltd.: S4030) except for using 5 parts by weight (Comparative Example 7) was prepared as in Example 5. Table 3 shows the results.

Comparative Example 8 In the production of the propylene homopolymer (component A) in Example 1, 3.0 g of a commercially available titanium trichloride catalyst manufactured by Toho Titanium Co., Ltd. and diethylaluminum chloride (Al (C ₂ H ₅₎ ) ₂ Cl) The polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 15.0 g. The obtained propylene homopolymer had an MFR of 10 g / 10 min and a density of 0.905.
7 g / cm ³ , isotactic pentad fraction of 91
Met. Production of the composition and measurement of physical properties were performed in the same manner as in Example 1. Table 3 shows the results.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

The propylene-based resin injection molded article of the present invention has impact resistance, rigidity, tensile elongation and excellent surface gloss. And so on.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23:08) B29K 23:00 (72) Inventor Masaru Uchida 1 Toho-cho, Yokkaichi-shi, Mie Japan Yokkaichi Technology Co., Ltd. Inside the center (72) Inventor Noriyuki Yada 1 Tohocho, Yokkaichi-shi, Mie Japan Inside Yokkaichi Technical Center, Polychem Corporation

Claims (5)

[Claims] 1. A melt flow rate of 0.5 to 100 g /
Min, density of 0.906 g / cm ³ or more, and isotactic pentad fraction of more than 96 crystalline polypropylene-based resin, 4 to 8 carbon atoms with respect to the resin 100 parts by weight of α
An olefin content of from 20 to 65% by weight and a melt flow rate (230 ° C., 2.16 kg) of 0.1%;
5-40 g / min, density 0.85-0.90 g / cm ³
And ethylene / α polymerized with a metallocene catalyst
A gloss of 81 obtained by injection molding a propylene resin composition containing 3 to 40 parts by weight of an olefin copolymer;
% Or more. 2. The injection molded article according to claim 1, wherein the ethylene / α-olefin copolymer is obtained by copolymerizing an α-olefin having 4 or more carbon atoms with ethylene. 3. A crystallization nucleating agent of 0.01 parts by weight based on 100 parts by weight of a crystalline polypropylene resin.
The injection-molded article according to claim 1, characterized in that it is contained in an amount of 0.5 parts by weight. 4. The injection molded article according to claim 1, wherein 3 to 30 parts by weight of an ethylene / α-olefin copolymer is blended with respect to 100 parts by weight of the polypropylene resin. 5. The injection molded article according to claim 1, wherein the ethylene / α-olefin copolymer has a rubbery property having a crystallinity of 0 to 22%.