JPH07133387A - Polypropylene resin composition - Google Patents

Abstract

(57) [Summary] [Structure] A polypropylene resin composition obtained by heating and mixing crystalline polypropylene and a copolymer of propylene and an α-ω diene having vinyl groups at both ends. [Effect] A polypropylene resin composition having an excellent balance of rigidity and impact resistance, and capable of making a molded product thinner.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin composition, and more particularly to a polypropylene resin composition containing a specific compound and having a good balance of rigidity and impact strength.

[0002]

2. Description of the Related Art Polypropylene has various moldability, has a relatively good balance of physical properties, has excellent electrical, mechanical and chemical properties, and can be obtained at low cost. It is used very well in various fields, but because the crystallinity is relatively small, molding with a normal method gives a molded product with a better balance of rigidity and impact resistance than the original resin. There is a problem that it is defective, and in order to solve this problem, change the molecular weight distribution,
A method of mixing polypropylenes having different physical properties, a method of adding various nucleating agents to increase rigidity, and a method of adding various rubbers to improve impact resistance are generally known.

On the other hand, propylene / diene copolymers have hitherto been used as crosslinkable polymers, and at least one of the diene compounds used is an internal olefin or vinylidene group, and α having both propylene and vinyl groups at both ends. The copolymerization reaction with -ω-diene has been hardly investigated because the activity of the conventional Ziegler-Natta catalyst is lowered, the copolymerization property is poor, and the block-type polymerization causes gelation.

Recently, it has been disclosed in JP-A-5-194659, JP-A-5-222121 and JP-A-5-222251 that an α-olefin / diene copolymer is useful for increasing the melt tension. Also,
It is known that when a metallocene catalyst is used, a copolymer having good copolymerization characteristics and a uniform composition distribution can be obtained in the copolymerization of propylene and α-ω diene. For example, a method for producing a copolymer having a specific structure by using a specific catalyst is disclosed in JP-A-4-25514.

[0005]

It is easy to improve either rigidity or impact resistance by conventional methods by improving the physical properties of polypropylene, but it is difficult to improve them in a well-balanced manner. . For example, in the method of adding a nucleating agent, since the crystallinity of polypropylene only increases, the rigidity increases, but the impact resistance decreases.
In addition, in the method of improving impact resistance by adding rubber, since soft rubber is added, the impact resistance can be improved, but the rigidity is lowered, and both are not always satisfactory as methods for improving the balance of physical properties. There wasn't.

[0006]

The present inventors have found that a copolymer of propylene and α-ω diene is effective for improving the balance between rigidity and impact resistance of polyolefins such as polypropylene. Found and completed the present invention.

An object of the present invention is to provide a propylene resin composition in which the balance between the rigidity and impact resistance of polyolefin is improved and a method for producing the same.

That is, the present invention relates to crystalline polypropylene (A)
And a copolymer (B) of propylene and an α-ω diene by heating and mixing.

As the crystalline polypropylene (A) used in the present invention, not only a homopolymer of propylene but also propylene and ethylene, butene-1,
It may be a random copolymer or a block copolymer with other olefins such as hexene-1, and those which are commercially available or widely available in the market can be used without any trouble. The molecular weight of this crystalline polypropylene is about 0.1 to 20 dl / g as the intrinsic viscosity [η] measured with a tetralin solution at 135 ° C., and the content of other olefins is 0 to 50% by weight.

In the production of these crystalline polypropylenes, the catalyst used for the polymerization is, for example, a titanium trichloride catalyst or a catalyst component in which a titanium compound such as titanium trichloride or titanium tetrachloride is supported on a magnesium compound, and an alkylaluminum cocatalyst. A carrier catalyst as a component is used. Furthermore, a catalyst composed of a metal complex of a group 3 or 4 of the periodic table having a cyclopentadienyl compound represented by a combination of dicyclopentadienyl zirconium dichloride and an aluminoxane and an aluminoxane compound, or A homogeneous catalyst using a metal cation complex of Groups 3 and 4 of the Periodic Table having a cyclopentadienyl compound as a ligand can also be used.

As the polymerization method, a conventional method such as a solvent polymerization method, a bulk polymerization method in which substantially no solvent is present, or a gas phase polymerization method can be used, and the polymerization conditions are not particularly limited, and the reaction temperature is usually room temperature. ~ 200 ℃, normal pressure ~ 50kg
/ Is carried out in cm ^2.

The propylene used in the present invention and the α-ω diene copolymer having vinyl groups at both ends are produced by copolymerizing propylene and α-ω diene having vinyl groups at both ends. The α-ω diene is a diene compound having an unsaturated bond at least in the α-position and the ω-position, and may be linear or branched as long as it is a diene compound having a vinyl group at both ends, oxygen Heteroatoms and atomic groups such as sulfur, boron, etc. may be contained. For example, 1-3 butadiene, 1-4 pentadiene, 1-5 hexadiene, 1-6 heptadiene, 1-7 octadiene, 1-
8 Nonadiene, 1-9 Decadiene, 1-10 Undecadiene, 1
-11 Dodecadiene, 1-13 tetradecadiene, divinylbenzene, etc. are exemplified. Among them, a diene compound having 6 or less carbon atoms is more preferable.

In the present invention, the copolymer of propylene and the above-mentioned diene is generally synthesized by using a catalyst composed of a transition metal compound and an organometallic compound. As the transition metal compound, titanium halide or organic compound is used. Polymerization can be carried out using a solid catalyst composed of an organoaluminum compound as the metal compound, or a catalyst composed of a transition metal catalyst soluble in a hydrocarbon solvent and an aluminoxane, and a copolymer obtained using a titanium halide solid catalyst. The effect of the present invention is not obtained with a polymer.

Therefore, a preferable catalyst for use in the polymerization is a group 3 of the periodic table containing a cyclopentadienyl compound represented by a combination of dicyclopentadienyl zirconium dichloride and aluminoxane as a ligand,
Activator consisting of an aluminoxane compound which is an oligomer or polymer obtained by reacting organoaluminum with water or water of crystallization, which is a group 4 or group 5 metal complex compound, or a cyclopentadienyl compound Periodic Table Group 3, Group 4, and Group 5
Catalysts that combine an activator consisting of a Group 3 metal cation complex and a compound that forms a stable anion are also available.

As the polymerization method, a conventional method such as a solvent polymerization method, a bulk polymerization method in which substantially no solvent is present, or a gas phase polymerization method can be used, and the polymerization conditions are not particularly limited, and the reaction temperature is usually room temperature. ~ 200 ℃, normal pressure ~ 50kg
/ Is carried out in cm ^2.

There are no particular restrictions on the polymerization ratio of the diene monomer and propylene, but usually the diene monomer is
It is about 0.0001 to 30 mol%, preferably 0.001 to 10 mol%, and the content of α-ω diene units in the copolymer obtained by such a method is in the range of 0.0001 to 5 mol%. preferable. In particular, if the α-ω diene content is less than 0.0001 mol%, the effect of the present invention is not achieved, and if it exceeds 5 mol%, the molecular weight of the copolymer becomes very large and the polymer becomes insoluble in the solvent. Further, even if heated, the infusible portion will be present, and the industrial utility value will be lost.

The copolymer of propylene and α-ω diene according to the present invention may be a random copolymer or a block copolymer. The molecular weight of this copolymer was 0.1 as the intrinsic viscosity [η] measured with a tetralin solution at 135 ° C.
It is preferably about 10 dl / g. In addition, the mmmm pentad fraction determined by ¹³ C-NMR of the propylene chain portion in the copolymer is 90% or more. A copolymer having a mmmm pentad fraction of less than 90% has a low stereoregularity of the polypropylene unit and is not preferable because the effect of improving the balance between the rigidity and impact resistance of the polyolefin is reduced.

What is important in the present invention is that the number of moles (M) of vinyl groups and the number of moles (M ₀ ) of α-ω diene units contained in the copolymer of propylene and α-ω diene are represented by the following formula (Formula 2) ) It is necessary to have a relationship represented by.

[0019]

[Equation 2] The number of moles (M) of the vinyl group contained in the copolymer can be calculated from the absorption spectrum of the vinyl group in the infrared absorption spectrum or NMR spectrum of the copolymer. Also α-
Similarly, the ω-diene content is determined by the infrared absorption spectrum of the copolymer and
It can be calculated from the NMR spectrum, but can also be calculated from the difference between the number of moles of the diene monomer supplied during the polymerization and the number of moles of the unreacted monomer at the end of the polymerization.

Number of moles of vinyl groups contained in the copolymer
(M) and the number of moles of the α-ω diene unit (M ₀ ) above is 0.9 or less means that both ends of the diene react and polypropylene is bonded with the diene, or the diene It is that the structure in which the two are bonded, or the structure in which the diene is cyclically introduced is 0.1 or more of the introduced diene, and particularly the copolymer of the present invention has high stereoregularity. It is thought that it has a structure in which polypropylene of diene is bonded with a diene, and such a structure has an effect of improving the balance between the rigidity and the impact resistance of the polyolefin when these copolymers are added to the polyolefin. It is considered to be a thing. On the other hand, in the case where one vinyl group of the diene introduced by copolymerization remains, polypropylene does not grow on both sides of the diene, and therefore the effect of improving the physical properties cannot be obtained. Therefore, the value of the above formula (Equation 2) is preferably 0.9 or less, and more preferably 0.5 or less. Further, in the copolymer of propylene and a diene obtained by using a titanium halide-based solid catalyst, the structure as described above cannot be taken because propylene is difficult to react at both ends of the introduced diene. It seems that the effect is not appearing.

The resin composition of the present invention is characterized by using an olefin copolymer (propylene / diene copolymer) having a boiling paraxylene insoluble content of 1% by weight or less.
If the boiling para-xylene insoluble content exceeds 1% by weight, that is, if the crosslinked gel content is more than 1% by weight, the mixing with the crystalline polypropylene cannot be carried out uniformly, resulting in a poor appearance and a gel. Is present in the molded product, and as a result, the effect of improving the physical properties is not exhibited, which is not preferable.

There is no particular limitation on the mixing method of the above-mentioned respective components or the mixing method with known additives such as antioxidants, ultraviolet absorbers, lubricants, antistatic agents, and other nucleating agents which are added as necessary. It is preferable that the respective components are mixed with a Henschel mixer, a V-type blender, etc., and then melt-mixed with an extruder, a roll, a Banbury mixer, a kneader, etc., and once granulated into pellets.

According to the present invention, it is possible to produce a molded product having a good balance of rigidity and impact resistance by molding by a method used for molding of ordinary polypropylene such as injection molding. The molding temperature is not particularly limited and may be a normal molding temperature, usually 200 to 300 ° C.

[0024]

The present invention will be further described with reference to the following examples.

Example 1 [Method for synthesizing propylene / diene copolymer] 1 liter of toluene was placed in a stainless steel autoclave having an internal volume of 2 liters, and 1.44 g of methylaluminoxane (manufactured by Tosoh Akzo, degree of polymerization 16.2) and 1, 5-hexadiene 3.6 g
Charged. Further, propylene gas was introduced at 20 ° C and 3
A solution prepared by dissolving 3 mg of dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride synthesized in a conventional manner as kg / cm ² -G in 10 ml of toluene was added, and the mixture was polymerized at 20 ° C. for 2 hours.

After the completion of the polymerization, unreacted propylene was purged and the polymer was taken out by filtration, vacuum dried at 80 ° C. for 8 hours and weighed to obtain 76.0 g of propylene / 1,5-hexadiene copolymer (hereinafter, It is referred to as a copolymer a).
The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography to calculate the reaction amount of 1,5-hexadiene, which was 0.75 g. The content of boiling para-xylene solubles was 99.5%, and no gel was formed. The IR absorption spectrum of the press sheet is shown in (FIG. 1-1), and the IR absorption spectrum of the polypropylene homopolymer used in Comparative Example 1 is shown in (FIG. 1-3).

This copolymer a has 906 cm ^-1 and 1640 cm ^-1.
(Not shown) has absorption of vinyl group, and it is clearly recognized that the diene is copolymerized. Further, the copolymer a is characterized by absorption of a vinylidene group at 884 cm ^-1 . ^{In 1} H-NMR, a signal of the terminal vinyl group is observed around 6 ppm, the amount is about 0.2 ppm, and it is considered that most of the double bonds have reacted. Also ¹³ C-NMR
The mmmm pentad fraction calculated from was 0.98, and the intrinsic viscosity (hereinafter referred to as η) measured with a 135 ° C tetralin solution was
The ratio of the weight average molecular weight to the number average molecular weight measured with 0.96, 1,2,4-trichlorobenzene (hereinafter referred to as MW / MN) is 3.
It was 3.

[Production of Resin Composition] The above-mentioned copolymer a is shown in (Table 1) with respect to 100 parts by weight of polypropylene (J3H or block copolymer BJHH manufactured by Mitsui Toatsu Chemicals, Inc.). In addition, 0.1 part by weight of an antioxidant and 0.1 part by weight of calcium stearate were added and mixed in a Henschel mixer, and then heated and mixed at 230 ° C. in an extruder to obtain pellets. Using the pellets, a test piece was molded with an injection molding machine (FSM55T, manufactured by Komatsu Ltd.) and the physical properties were measured. The results are shown in (Table 1). Flexural modulus is ASTM D790, tensile strength is ASTMD
882 and Izod impact strength were measured according to ASTM D256.

Comparative Example 1 The procedure of Example 1 was repeated except that polypropylene (J3H or block copolymer BJHH, manufactured by Mitsui Toatsu Chemicals, Inc.) was used without adding a propylene / diene copolymer. . The results are shown in (Table 1).

Example 2 Copolymerization was carried out in the same manner as in Example 1 except that 2.0 g of 1,7-octadiene was used instead of 1,5-hexadiene, and 74.0 g of propylene / 1,7-octadiene copolymer was obtained. A polymer (hereinafter referred to as a copolymer b) was obtained. The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography to calculate the reaction amount of 1,7-octadiene, which was 0.74 g. The content of boiling para-xylene solubles was 99.5%, and no gel was formed. In addition, the IR absorption spectrum of the press sheet (Fig. 1
-2).

The copolymer b obtained had 906 cm ^-1 and 1640.
There is a vinyl group absorption at cm ^-1 (not shown), and it is clearly recognized that the diene is copolymerized. Also, the copolymer b
Is characterized by absorption of vinylidene group at 884 cm ^-1 . ^{In 1} H-NMR, a signal of the terminal vinyl group was observed at around 6 ppm, and the amount was about 0.3 ppm, and it is considered that most of the double bonds have reacted. Also ¹³ C-NMR
The mmmm pentad fraction calculated from is 0.98, and η is 1.2.
6, MW / MN was 3.2. Further, this copolymer b was used as polypropylene (J3H, manufactured by Mitsui Toatsu Chemicals, Inc.) 100
The same procedure as in Example 1 was carried out except that the proportions shown in (Table 1) were used with respect to parts by weight. The results are shown in (Table 1).

Example 3 Copolymerization was carried out in the same manner as in Example 1 except that 1.8 g of 1,4-pentadiene was used instead of 1,5-hexadiene, and 107.8 g of propylene / 1,4-pentadiene copolymer was obtained. A polymer (hereinafter referred to as a copolymer c) was obtained. The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography and the reaction amount of 1,4-pentadiene was calculated to be 0.8 g. The boiling para-xylene soluble content was 99.5%, and no gel was formed. ^{In 1} H-NMR, a signal of the terminal vinyl group was observed at around 6 ppm, and the amount was about 0.3 ppm, and it is considered that most of the double bonds have reacted. The mmmm pentad fraction obtained from ¹³ C-NMR is 0.98, η is 1.45, MW
/ MN was 3.4. Further, this copolymer c was used in the same manner as in Example 1 except that 100 parts by weight of polypropylene (J3H manufactured by Mitsui Toatsu Chemicals, Inc.) was used in the ratio shown in (Table 1). The results are shown in (Table 1).

Comparative Example 2 A copolymerization was conducted in the same manner as in Example 1 except that 13.0 g of 1,5-hexadiene was used in Example 1.
118.4 g of propylene / 1,5-hexadiene copolymer (hereinafter referred to as copolymer d) was obtained. The boiling para-xylene soluble content of this copolymer d was 29.5%, and a large amount of gel was formed. Further, this copolymer d was used as a polypropylene block copolymer (BJHH, manufactured by Mitsui Toatsu Chemicals, Inc.) 10
The same procedure as in Example 1 was carried out except that the proportion shown in (Table 1) was used with respect to 0 part by weight. The molded product had a poor appearance due to gel. In addition, there was almost no improvement effect due to the physical properties of the gel. The results are shown in (Table 1).

Comparative Example 3 In Example 2, 5 mg of isopropylidene (cyclopentadienylfluorenyl) zirconium dichloride was used as a polymerization catalyst instead of dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride. Copolymerization was performed in the same manner as in Example 2 except that 3.2 g of 7,7-octadiene was used and the amount of methylaluminoxane was changed to 1.44 g. 114.5 g of propylene / 1,7-octadiene copolymer (hereinafter referred to as copolymer It is referred to as a combined e.).
The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography to calculate the reaction amount of 1,7-octadiene, which was 1.85 g. The content of boiling para-xylene solubles was 99.5%, and no gel was formed. The mmmm pentad fraction determined from ¹³ C-NMR was 0.10, η was 1.79 and MW / MN was 4.3. Further, this copolymer e was added to 100 parts by weight of polypropylene (J3H, manufactured by Mitsui Toatsu Chemicals, Inc.) (Table 1).
The same procedure as in Example 1 was carried out except that the ratio was used in the above. The appearance of the molded product was good, but there was no effect of improving the physical properties. The results are shown in (Table 1).

[0035]

[Table 1]

[0036]

EFFECTS OF THE INVENTION The composition of the present invention has an excellent balance of rigidity and impact resistance as compared with hitherto known compositions, and it is possible to reduce the thickness of molded products, which is extremely industrially valuable.

[Brief description of drawings]

1 is an IR absorption spectrum of a propylene / diene copolymer, where 1 is the IR of the copolymer a obtained in Example 1.
2 shows the absorption spectrum, and 2 shows the IR absorption spectrum of the copolymer b obtained in Example 2. Further, 3 is Comparative Example 1
2 shows an IR absorption spectrum of the polypropylene homopolymer used in.

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[Procedure amendment]

[Submission date] November 25, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

The propylene used in the present invention and the α-ω diene copolymer having vinyl groups at both ends are produced by copolymerizing propylene and α-ω diene having vinyl groups at both ends. The α-ω diene is a diene compound having an unsaturated bond at least in the α-position and the ω-position, and may be linear or branched as long as it is a diene compound having a vinyl group at both ends, oxygen Heteroatoms and atomic groups such as sulfur, boron, etc. may be contained. For example 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,
Examples include 8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,13-tetradecadiene and divinylbenzene. Among them, it has 6 carbon atoms
The following diene compounds are more preferred.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

This copolymer a has 906 cm ^-1 and 1640 cm ^-1.
(Not shown) has absorption of vinyl group, and it is clearly recognized that the diene is copolymerized. Further, the copolymer a is characterized by absorption of a vinylidene group at 884 cm ^-1 . ^{In 1} H-NMR, a signal of the terminal vinyl group was observed at around 6 ppm, and the amount was about 0.2% by weight, and it is considered that most of the double bonds have reacted. Also ¹³ C-NM
The mmmm pentad fraction obtained from R is 0.98 and is 135 ° C.
Intrinsic viscosity measured with tetralin solution (hereinafter referred to as η)
Is 0.96, and the ratio of the weight average molecular weight to the number average molecular weight measured with 1,2,4-trichlorobenzene (hereinafter referred to as MW / MN) is
It was 3.3.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

The copolymer b obtained had 906 cm ^-1 and 1640.
There is a vinyl group absorption at cm ^-1 (not shown), and it is clearly recognized that the diene is copolymerized. Also, the copolymer b
Is characterized by absorption of vinylidene group at 884 cm ^-1 . ^{In 1} H-NMR, a signal of the terminal vinyl group was observed at around 6 ppm, and the amount was about 0.3% by weight, and it is considered that most of the double bonds have reacted. Also ¹³ C-
The mmmm pentad fraction obtained from NMR is 0.98, and η is
The value was 1.26 and MW / MN was 3.2. Further, this copolymer b was used as polypropylene (J3H, manufactured by Mitsui Toatsu Chemicals, Inc.) 10
The same procedure as in Example 1 was carried out except that the proportion shown in (Table 1) was used with respect to 0 part by weight. The results are shown in (Table 1).

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Example 3 Copolymerization was carried out in the same manner as in Example 1 except that 1.8 g of 1,4-pentadiene was used instead of 1,5-hexadiene, and 107.8 g of propylene / 1,4-pentadiene copolymer was obtained. A polymer (hereinafter referred to as a copolymer c) was obtained. The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography and the reaction amount of 1,4-pentadiene was calculated to be 0.8 g. The boiling para-xylene soluble content was 99.5%, and no gel was formed. ^{In 1} H-NMR, a signal of the terminal vinyl group was observed at around 6 ppm, and the amount was about 0.3% by weight, and it is considered that most of the double bonds have reacted. Also ¹³ C-NMR
The mmmm pentad fraction calculated from is 0.98, and η is 1.4
5, MW / MN was 3.4. Further, this copolymer c was used as polypropylene (J3H, manufactured by Mitsui Toatsu Chemicals, Inc.) 100
The same procedure as in Example 1 was carried out except that the proportions shown in (Table 1) were used with respect to parts by weight. The results are shown in (Table 1).

Claims (3)

[Claims] 1. A copolymer of crystalline polypropylene (A), propylene and an α-ω diene having vinyl groups at both ends.
A polypropylene resin composition obtained by heating and mixing with (B). 2. The crystalline polypropylene (A) is 100 parts by weight and the copolymer (B) of propylene and an α-ω diene having vinyl groups at both ends is 0.1 to 30 parts by weight. Polypropylene resin composition. 3. Propylene and α having vinyl groups at both ends
The copolymer (B) with -ω diene has a content of the α-ω diene unit in the range of 0.0001 to 5 mol%, and the number of moles (M) of vinyl groups contained in the copolymer (B). And the number of moles of α-ω diene unit (M ₀ ) are represented by the following formula (Equation 1), the boiling para-xylene insoluble content is 1% by weight or less, and ¹³ C-NMR of the propylene chain part Mmmm pentad fraction 90%
The polypropylene resin composition according to claim 1, which is a propylene / diene copolymer having an intrinsic viscosity [η] measured with a tetralin solution at 135 ° C. in the range of 0.1 to 10 dl / g. [Equation 1]