JPH09309982A - Polypropylene resin composition - Google Patents

Abstract

(57) [PROBLEMS] To provide a polypropylene resin composition having excellent flexibility, heat resistance and scratch resistance, and having high tensile elongation. SOLUTION: The polypropylene resin composition contains 5 to 95% by weight of the following component (A) and 95 to 5% by weight of the component (B). (A): Crystalline polypropylene resin (B): Amorphous polypropylene resin whose n-hexane insoluble content at a temperature of 25 ° C. is 2% by weight or less.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a polypropylene resin composition. More specifically, the present invention relates to a polypropylene resin composition having excellent flexibility, heat resistance and scratch resistance and having high tensile elongation.

[0002]

2. Description of the Related Art Polypropylene resins are widely used in the fields of home electric appliances, automobile parts, miscellaneous goods, etc. due to their excellent characteristics. Polypropylene resins used in these fields are required to have excellent flexibility, heat resistance, scratch resistance, and high tensile elongation, but the required levels have become more sophisticated in recent years. It's starting. Under these circumstances, conventional polypropylene resins have not always been satisfactory.

For the purpose of improving softness and heat resistance, a composition mainly composed of 10 to 90% by weight of boiling heptane-soluble polypropylene and 90 to 10% by weight of boiling heptane-insoluble polypropylene has been disclosed (Japanese Patent Publication No. 7-11).
9292 publication). However, the polypropylene resin composition has not been satisfactory in terms of the softening effect.

[0004]

The problem to be solved by the present invention is to provide a polypropylene resin composition which is excellent in flexibility, heat resistance and scratch resistance and has a high tensile elongation.

[0005]

That is, the present invention relates to a polypropylene resin composition containing the following (A) component 5 to 95% by weight and the (B) component 95 to 5% by weight. (A): Crystalline polypropylene-based resin (B): Amorphous polypropylene-based resin having an n-hexane insoluble content of 2% by weight or less at a temperature of 25 ° C.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) of the present invention is a crystalline polypropylene resin, which is a homopolymer of propylene or a random or block copolymer of propylene and a small amount of α-olefin. When the polypropylene resin is a copolymer, in the case of a random copolymer, the other α-olefin copolymerization ratio in the copolymer is
Generally, it is 10% by weight or less, preferably 0.5 to 7% by weight, and in the case of a block copolymer, other α-in the copolymer.
The copolymerization ratio of olefin is generally 1 to 40% by weight, preferably 1 to 25% by weight, more preferably 2 to 20% by weight, and particularly preferably 3 to 15% by weight. These polypropylene-based polymers may be a combination of two or more polymers. As an index of the crystallinity of polypropylene, for example, a melting point, a heat of crystal fusion, or the like is used, and the melting point is 12
0 ° C to 176 ° C, heat of fusion of crystal is 60 J / g to 120 J
/ G is preferable. If the melting point of the crystal is too low or the heat of fusion is too low, the heat resistance of the material will be poor.

As a method for producing the component (A), generally, a Ziegler-Natta type catalyst using a combination of a so-called solid titanium-containing transition metal component and an organic metal component, particularly, the transition metal component is titanium or magnesium. And a halogen as an essential component, a solid component or titanium trichloride with an electron-donating compound as an optional component, and a slurry polymerization using a catalyst in which the organometallic component is an aluminum compound,
One-stage or multi-stage polymerization method such as gas phase polymerization, bulk polymerization, solution polymerization or a combination thereof, propylene homopolymer is obtained by homopolymerizing propylene, or propylene and α having 2 or 4 to 12 carbon atoms. -Olefins,
Preferable examples include a method of obtaining a propylene / α-olefin copolymer by copolymerizing ethylene with ethylene in one or more stages. A commercially available product may be used.

The component (B) of the present invention is an amorphous polypropylene resin having an n-hexane insoluble content of 2% by weight or less at a temperature of 25 ° C., and is a propylene homopolymer.

The component (B) has an n-hexane insoluble content at 25 ° C. of 2% by weight or less, preferably 1% by weight or less. If the insoluble content is too large, the flexibility of the amorphous polypropylene may be insufficient, the flexibility of the blend composition with the crystalline polypropylene may be insufficient, or the scratch resistance may be poor. is there. The method for measuring the insoluble content is as follows.

(I) The sample is shredded to a size of about 1 mm square, and 0.5 g is used as a standard, and Xg is weighed. (Ii) The weighed sample was placed in an Erlenmeyer flask with a stopper, and the antioxidant Sumitizer BHT (2,6-di-tert) was added.
-Butyl-4-methylphenol) 0.1
Add 250 ml of wt% n-hexane solvent, and add 25
Leave for 24 hours in a constant temperature water bath at ℃. (Iii) Set the flask on a shaker and shake to 12
Shake at 0 rpm for 1 hour. (iv) Filtration is carried out using a 120-mesh wire net (Yg) which has been weighed in advance. (v) The filtered wire net is dried by a vacuum dryer at 80 ° C. for 3 hours, and the weight Zg of the wire net + insoluble portion is weighed. (vi) The n-hexane insoluble part (wt%) is calculated by the following formula. n-hexane insoluble part (wt%) = 100 × (Z−Y) /
X

The component (B) is a differential scanning calorimeter (DSC).
It is preferably an amorphous polypropylene-based resin having neither a crystal melting peak nor a crystallization peak of 1 J / g or more when measured by. When using those having such a peak, the flexibility of the amorphous polypropylene is insufficient, or the flexibility of the blend composition with the crystalline polypropylene is insufficient, or the scratch resistance is poor. I have something to do. Amorphous polypropylene has rubber-like properties at room temperature and only exhibits a glass transition temperature when heated, which is below 0 ° C. for the preferred amorphous polypropylene. It should be noted that the differential scanning calorimeter (DSC) measurement is performed in 10
Perform at a rate of (° C / min).

Component (B) is a molecular weight distribution non-uniformity index Mw.
/ Mn (Mw represents a weight average molecular weight and Mn represents a number average molecular weight) is preferably 5 or less. If the index is too large, the amount of low molecular weight components also increases, the tensile elongation of the blended composition with crystalline polypropylene may decrease, and bleeding of low molecular weight components may cause the molded article to become sticky.

The molecular weight distribution was measured by gel permeation chromatography (GPC) method (Waters, 15
0CV ALC / GPC). Elution temperature is 1
40 ° C, the column used is Shodex Pa manufactured by Showa Denko KK
cked Column AT-806 M / S 8m
mφ × 250 mm (2), molecular weight standard substance is polystyrene (Made by Tosoh Corporation, molecular weight 68-8,400,000)
Was used. Using the obtained polystyrene-converted weight average molecular weight (Mw) and number average molecular weight (Mn), this ratio (Mw
/ Mn) was used as the molecular weight distribution non-uniformity index. As a measurement sample, about 5 mg of the polymer was dissolved in 5 ml of o-dichlorobenzene to have a concentration of about 1 mg / ml. 400 μl of the obtained sample solution was injected. The flow rate of the eluting solvent was 1.0 ml / min, and the refractive index detector was used for detection.

The intrinsic viscosity [η] of the amorphous polypropylene as the component (B) was measured in xylene at 70 ° C. using an Ubbelohde viscometer. Sample is 300mg 100m
It was dissolved in 1 xylene to prepare a 3 mg / ml solution.
Further, the solution was diluted to 1/2, 1/3, and 1/5, and each was measured in a constant temperature water bath at 70 ° C (± 0.1 ° C). The measurement was repeated three times at each concentration, and the obtained values were averaged and used.

The component (B) is usually an amorphous polypropylene resin obtained by using a metallocene catalyst. Here, as a preferable metallocene catalyst, one represented by the following chemical formula (1) can be given.

[0016]

(In the formula, M represents a transition metal element of Group 4 of the periodic table of elements, Cp represents cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl,
Represents fluorenyl or substituted fluorenyl. A represents an element of group 16 of the periodic table of elements, and B represents an element of group 14 of the periodic table of elements. X ¹ and X ² are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, and 1 to 2 carbon atoms.
0 represents an alkoxy group or an amide group having 1 to 20 carbon atoms, which may be the same or different. R ^{1 to} R ⁶ are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and 1 carbon atom. ~ 20
Represents an amide group or a silyl group having 1 to 20 carbon atoms,
They may be the same or different, and they may optionally be combined to form a ring. )

Examples of the method for producing the component (B) include aliphatic hydrocarbons such as butane, pentane, hexane, heptane and octane, aromatic hydrocarbons such as benzene and toluene, and halogenated carbonization such as methylene dichloride. Solvent polymerization using hydrogen as a solvent, or slurry polymerization,
Gas phase polymerization or the like in a gaseous monomer is possible, and both continuous polymerization and batch polymerization are possible. The polymerization temperature may be in the range of -50 ° C to 200 ° C, but is particularly preferably in the range of -20 ° C to 100 ° C, and the polymerization pressure is preferably atmospheric pressure to 60 kg / cm 2 G. The polymerization time is generally appropriately determined depending on the type of the catalyst to be used and the reactor, but can range from 1 minute to 20 hours. Further, a chain transfer agent such as hydrogen can be added to adjust the molecular weight of the polymer.

The polypropylene resin composition of the present invention is
It contains (A) component 5 to 95% by weight and (B) component 95 to 5% by weight ((A) + (B) = 100% by weight). In addition, 90 to 20 weight% of (A) component and 10 to 80 weight% of (B) component are more preferable, 70 to 30 weight% of (A) component and 30 to 70 of (B) component are more preferable.
% By weight. Excessive amount of (A) component (excessive amount of (B) component)
If so, the fluidity becomes low, the moldability is poor, the strength is insufficient, and the heat resistance is poor. On the other hand, if the amount of component (A) is too large (the amount of component (B) is too small), the flexibility becomes poor. Poor or poor scratch resistance.

In addition to the essential components (A) and (B), the polypropylene resin composition of the present invention may optionally contain other rubber components such as ethylene-propylene copolymer rubber, Ethylene-propylene-non-conjugated diene copolymer rubber, ethylene-butene-1 copolymer rubber, polybutadiene, styrene-butadiene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, styrene-butadiene random copolymer Polymer rubber, partially hydrogenated styrene-butadiene-styrene block copolymer rubber, partially hydrogenated styrene-butadiene random copolymer rubber, styrene-isoprene block copolymer rubber, partially hydrogenated styrene-isoprene block copolymer rubber, etc. May be added. Further, if necessary, a crosslinking reaction can be carried out by adding a peroxide. Furthermore,
If necessary, antioxidants, heat stabilizers, UV absorbers,
A lubricant, an antistatic agent, a pigment, a filler and a flame retardant may be added.

As a method for obtaining the polypropylene resin composition of the present invention, a method of melt-kneading the respective components with a twin-screw extruder, a Banbury mixer or the like can be mentioned. The polypropylene resin composition of the present invention can be optimally used for home electric appliances, automobile parts, miscellaneous goods, etc. by utilizing its excellent characteristics.

[0022]

The present invention will be described below with reference to examples. The present invention will be described in more detail with reference to the following examples, which are for the purpose of illustration and do not limit the present invention. Examples 1 and 2 and Comparative Examples 1 to 3 <Production of amorphous polypropylene>

Reference Example 1 A separable flask reactor having a capacity of 2 l was equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser to reduce the pressure, and then the atmosphere was replaced with nitrogen. 1 l of dried toluene was introduced into this flask as a polymerization solvent.
Propylene 8 NL / min was continuously fed to the mixture at normal pressure to adjust the solvent temperature to 30 ° C. After adding 1.25 mmol of triisobutylaluminum (hereinafter abbreviated as TIBA) to the polymerization tank, (t-butylamide) was used as a polymerization catalyst.
0.005 mmol of dimethyl (tetramethyl- [eta] ⁵ -cyclopentadienyl) silanedichlorotitanium was added to the polymerization tank. 15 seconds later, 0.005 mmol of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added to the polymerization tank to initiate polymerization. As a result of polymerization for 30 minutes, polypropylene 43.9 g
was gotten.

Reference Example 2 In Reference Example 1, as a polymerization catalyst (tetramethyl-η ⁵ -cyclopentadienyl)
The procedure was basically the same except that dimethyl (3-t-butyl-5-methoxy-2-phenoxy) silanedichlorotitanium was used, and 65.6 g of polypropylene was obtained. Using a twin-screw batch-type kneading machine Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.), the composition shown in Table 1 was heated at 200 ° C.
Kneading was performed for 3 minutes at a screw rotation speed of 100 rpm.
The resin composition was pressed at 200 ° C. to form a 2 mm thick sheet. For the physical property test, a test piece was punched out from the press sheet and measured.

The characteristics described in Examples and Comparative Examples were measured by the following methods. (1) Hardness: ASTM D2240 (2) Bending test: JIS K7203 (3) Tensile test: JIS K6301 No. 3 dumbbell was used, and the test was performed at a tensile speed of 200 (mm / min). (4) Scratch resistance test: Surface property measuring instrument A scratching needle having a load of 500 g was used to scratch a 2 mm thick press sheet of the sample at a constant speed using a Tribogear (manufactured by Shinto Kagaku Co., Ltd.) to scratch the sample. The scratch depth is measured by a contact-type surface roughness tester.
It was measured by Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.) on a scale of μm order. (5) Haze: JIS K7105 Measurement was performed on a 2 mm-thick press sheet.

The results show the following. Example 1 and Example 2 satisfying the conditions of the present invention show satisfactory results in all evaluation items. On the other hand, Comparative Example 1 using crystalline polypropylene as the component (B), Comparative Example 2 using an ethylene-propylene copolymer instead of the polypropylene of the component (B), and comparison using an ethylene-butene copolymer. In each of Example 3, the flexural modulus is high (that is, the flexibility is poor), the tensile elongation is low, and the scratch resistance is poor.

[0027]

[Table 1] ---------------------------------------------- Examples Comparative Example 1 2 1 2 3 Blend (A) * 1 Amount wt% 50 50 50 50 50 (B) Type * 2 B-1 B-2 B-3--Characteristic n-Hex Insoluble matter wt% * 3 0 0.04 22.44 Crystal peak * 4 None None Yes Mw / Mn 3.2 3.3 19.0 Quantity wt% 50 50 50 0 0 (C) Type * 5---C-1 C-2 Quantity wt% 0 0 0 50 50 Crystal peak * 4 Yes Yes Hardness Shore A 93 92 93 96 93 Shore D 53 50 53 54 56 Flexural modulus kgf / cm ² 1550 2060 3280 4110 4700 Tensile strength kgf / cm ² 81 95 57 99 129 Tensile elongation% 560 640 10 250 20 Wound depth μm 32 28 121 117 70 Haze (2mmt)% 94 97 89 97 91 PP Crystal heat of fusion mJ / mg 52.0 50.4 57.8 48.6 50.4 −−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−

* 1 (A): Homopolypropylene having a MI of 14 (g / 10 min) under a load of 2.16 kg at 230 ° C. * 2 (B) B-1: Amorphous polypropylene prepared in Reference Example 1. 7
The intrinsic viscosity [η] measured using 0 ° C xylene as a solvent was 2.26 (dl / g). FIG. 1 shows a DSC chart. B-2: Amorphous polypropylene prepared in Reference Example 2. 7
The intrinsic viscosity [η] measured using 0 ° C xylene as a solvent was 2.96 (dl / g). FIG. 2 shows a DSC chart. B-3: Atactic polypropylene Sumitic SK
-11C (manufactured by Sumitomo Chemical Co., Ltd.) is polymerized by a Ziegler-Natta type catalyst that uses a solid transition metal component containing titanium and an organometallic component in combination. Melt viscosity measured at 170 ° C. using a B type viscometer is 300 to 5000 c
ps. * 3 n-Hex insoluble matter: n-hexane insoluble matter at a temperature of 25 ° C * 4 Crystal peak: presence or absence of crystal melting peak and crystallization peak when measured by differential scanning calorimeter (DSC) * 5 (C) C- 1: Ethylene propylene rubber (EPR) Tufmer S4030 (manufactured by Mitsui Petrochemical) Propylene content = 63 wt
%, Mooney viscosity (ML1 + 4 121 ° C.) = 48 C-2: Ethylene butene rubber (EBR) Esplen S
PO N0394 (Sumitomo Chemical) butene content = 17 wt
%, 230 ° C., MI under 2.16 kg load is 7.3 (g / g)
10 min)

[0029]

As described above, according to the present invention, it is possible to provide a polypropylene resin composition having excellent flexibility, heat resistance and scratch resistance and having high tensile elongation.

[Brief description of drawings]

FIG. 1D of the amorphous polypropylene prepared in Reference Example 1
It is an SC chart.

FIG. 2 D of amorphous polypropylene prepared in Reference Example 2
It is an SC chart.

Claims (5)

[Claims] 1. A polypropylene resin composition containing 5 to 95% by weight of the following component (A) and 95 to 5% by weight of component (B). (A): Crystalline polypropylene-based resin (B): Amorphous polypropylene-based resin having an n-hexane insoluble content of 2% by weight or less at a temperature of 25 ° C. 2. The polypropylene resin according to claim 1, wherein (B) is an amorphous polypropylene resin having neither a crystal melting peak nor a crystallization peak as measured by a differential scanning calorimeter (DSC). Composition. 3. The molecular weight distribution non-uniformity index Mw / M of (B).
The polypropylene resin composition according to claim 1, wherein n (Mw represents a weight average molecular weight and Mn represents a number average molecular weight) is 5 or less. 4. The polypropylene resin composition according to claim 1, wherein (B) is an amorphous polypropylene resin obtained by using a metallocene catalyst. 5. The polypropylene resin composition according to claim 4, wherein the metallocene catalyst is represented by the following chemical formula (1). (Wherein, M represents a transition metal element of Group 4 of the Periodic Table of the Elements, Cp represents cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl or substituted fluorenyl. A represents the element. Represents an element belonging to Group 16 of the periodic table, and B represents an element belonging to Group 14 of the periodic table.X ¹ and X ² represent a hydrogen atom, a halogen atom, or a hydrocarbon having 1 to 20 carbon atoms. group, halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group or an amide group having 1 to 20 carbon atoms having 1 to 20 carbon atoms, they may be the same or different .R ¹ to R ⁶ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms,
Represents an alkoxy group of 20; an amide group of 1 to 20 carbon atoms; or a silyl group of 1 to 20 carbon atoms, which may be the same or different, and may be arbitrarily combined to form a ring. Good. )