JP2844299B2 - Polypropylene composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polypropylene composition having a high melt tension. More specifically, the present invention relates to a polypropylene composition having a high melt tension and a high crystallization temperature, having excellent rigidity and moldability, and having a high melt tension that can be used again as a molded article, then re-melted and recycled.

[0002]

[Prior art and its problems] Crystalline polypropylene is
It is widely used in various molding fields because it has excellent mechanical properties, chemical resistance and the like, and is extremely useful in balance with economy. However, since the melt tension is low and the crystallization temperature is low, the moldability such as hollow molding, foam molding, and extrusion molding is poor.

As a method for increasing the melt tension and crystallization temperature of crystalline polypropylene, a method of reacting an organic peroxide and a crosslinking assistant with crystalline polypropylene in a molten state (JP-A-59-93711, JP-A-61-
No. 152754), however, there is a problem that the modified polypropylene obtained by using the crosslinking aid has an odor remaining. In addition, the melt tension is not sufficiently improved, and if the amount of the organic peroxide and the crosslinking aid is increased to increase the melt tension, a gel will be generated. It was impossible to do that.

On the other hand, Japanese Patent Application Laid-Open No. 2-298536 discloses that a polypropylene having a free-end long-chain branch and containing no gel is prepared by reacting a semi-crystalline polypropylene with a peroxide having a low decomposition temperature in the absence of oxygen. Although a method for obtaining the polypropylene has been disclosed, improvement in the melt tension of the obtained polypropylene has been insufficient.

[0005]

As described above, the polypropylene obtained by the method of the prior application has insufficient melting tension and crystallization temperature, has an odor, and contains a gel. After using it as a molded product,
There was a problem that it was impossible to re-melt and use it for recycling.

[0006] The present inventors have already made a specific organic peroxide react with polypropylene under specific conditions, and further melt-knead to obtain a polypropylene having a specific structure and properties. Have been found to solve the problems of the known invention ( JP-A-6-157666, JP-A-6-157666).
263823, JP-A-6-299013 , hereinafter these inventions may be referred to as prior inventions).

As a result of further studies, the present inventors have found that the composition comprising the polypropylene obtained by the above-mentioned invention and the ordinary polypropylene obtained by the conventional method has a different melt tension, crystallization temperature and rigidity. They have discovered that they show a synergistic effect, and have led to the present invention.

As is apparent from the above description, it is an object of the present invention to provide a material having extremely high melt tension and crystallization temperature, excellent rigidity and moldability, and, after being used as a molded article, re-melted and recycled. It is another object of the present invention to provide a polypropylene composition.

[0009]

The present invention has the following constitutions (1) to (5). (1) 100 parts by weight of (A) crystalline polypropylene (PP1), (B) a branching index of substantially 1, and a melt tension (MS) at 230 ° C. and an intrinsic viscosity measured at 135 ° C. in tetralin. [Η] is log (M
S)> 4.24 log [η] −0.843, and the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC) are (Tc)> 0.784
× (Tm)-A polypropylene composition containing 1 to 900 parts by weight of high melt tension polypropylene (PP2) that satisfies the relationship represented by -4.00 and has a residual boiling xylene extraction ratio of 1% by weight or less.

(2) High melt tension polypropylene (PP)
2) In an inert gas atmosphere, 1 to 10 mmol of di-2-ethylhexyl peroxydicarbonate was added and mixed per 100 g of linear crystalline polypropylene (PP3), and mixed at a temperature of 70 to 150 ° C. After melt-kneading for 10 minutes to 3 hours, the branching index is substantially 1, and the melt tension (MS) at 230 ° C and the intrinsic viscosity measured at 135 ° C in tetralin. [Η] is log (MS)> 4.24.
× log [η] −0.843, and the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC) are (Tc)> 0.784 ×
(Tm) The polypropylene composition according to the above (1), which is a high melt tension polypropylene (PP2) satisfying the relationship of -4.00 and having a residual boiling xylene extraction ratio of 1% by weight or less.

(3) Linear crystalline polypropylene (P
P3) is calculated as weight average molecular weight (Mw) / number average molecular weight (M
The polypropylene composition according to the above (2), which is a linear crystalline polypropylene having a value (Q) of n) of 7 to 30.

(4) Linear crystalline polypropylene (P
P3) comprises 1 to 50% by weight of a linear crystalline polypropylene (PP4) having an intrinsic viscosity [η] of 2.5 to 10 dl / g measured at 135 ° C. in tetralin. Intrinsic viscosity [η] is 1.0 to 4.0 d
The polypropylene composition according to the above (2), which is 1 / g of a linear crystalline polypropylene (PP3).

(5) Linear crystalline polypropylene (P
The polypropylene according to (2), (3), or (4), wherein P3) is a propylene homopolymer and / or a propylene-olefin random copolymer containing 10% by weight or less of an olefin polymerization unit other than propylene. Composition.

The configuration of the present invention will be described in detail below. The polypropylene composition of the present invention is a polypropylene composition containing a polypropylene having a specific high melt tension in addition to a polypropylene obtained by a known ordinary method. (A) Polypropylene (PP) which is a component of the composition of the present invention
1) is a polypropylene obtained by a known ordinary method. For example, a titanium catalyst component (a solid catalyst component containing titanium trichloride as a main component and further containing an electron donor, or a solid catalyst component containing titanium tetrachloride supported on a carrier such as magnesium chloride and further containing an electron donor) A slurry polymerization method in an inert solvent using a so-called Ziegler-Natta catalyst in which a so-called Ziegler-Natta catalyst is used, in which propylene itself is used as a solvent. Propylene or polypropylene obtained by polymerizing propylene and an olefin other than propylene by a known method combining a gas phase polymerization method or a gas phase polymerization method in a gas phase mainly containing propylene gas, or a combination thereof is used. More specifically, one or more of known propylene homopolymers, propylene-olefin random copolymers, and propylene-olefin block copolymers are used.

The other component (B) of the composition of the present invention, (B) high melt tension polypropylene (PP2) is a linear polypropylene having a branching index of substantially 1.
The branching index indicates the degree of long-chain branching, and is generally defined by the following equation. Branching degree index (g) = [η] _Br / [η] _Lin Here, [η] _Br is the intrinsic viscosity of the branched polypropylene, and in this specification, (B) high melt tension polypropylene which is an essential component of the present invention. This is the measured value [η] _Obs of (PP2). [Η] _Lin is described later in this specification in (B)
In the method for producing high melt tension polypropylene (PP2), the above-mentioned [η] _Obs sample obtained by the same method as the linear crystalline polypropylene (PP3) obtained by a known method used as a raw material is used. It is the intrinsic viscosity of a linear crystalline polypropylene having the same weight average molecular weight. The above ratio of the intrinsic viscosity indicates the degree of branching of the non-linear polymer, and is less than 1 when a long-chain branch is present.

The intrinsic viscosity was measured at 135 ° C. on a sample dissolved in tetralin. Also,
Weight average molecular weight (Mw) and number average molecular weight (Mn)
By American Laboratory, Ma by MLMcConnell
y, 63-75 (1978), ie, low angle laser light scattering photometry.

The high melt tension polypropylene (B2), which is an essential component of the present invention, has a degree of branching index of substantially 1 according to the above definition and measurement method, and does not have a long-chain branched structure. In addition, being substantially 1 means that
This means that even if there is a long-chain branch, it is not more than the detection limit by the above-mentioned method, and that it includes 1 including the range of statistical error when the same sample is repeatedly measured by the above-mentioned method. Therefore, the practical value is 0.95
It shows a value of about 1.05.

Furthermore, (B) the high melt tension polypropylene (PP2) has the following four essential requirements. That is, the melt tension (MS) at 230 ° C. and the intrinsic viscosity [η] measured in tetralin at 135 ° C. are log (M
S)> 4.24 log [η] −0.843, and the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC) are (Tc)> 0. 784
× (Tm) −4.00, and the residual rate of boiling xylene extraction is 1% by weight or less.

As described above, the melt tension of (B) high melt tension polypropylene (PP2) required to achieve the object of the present invention is as follows.
S) and intrinsic viscosity [η] measured at 135 ° C. in tetralin are such that log (MS)> 4.24 log [η] −
It is necessary to have a relationship represented by 0.843, and preferably log (MS)> 4.24 log [η] −0.68
5, more preferably log (MS)>
It is desirable that the relationship be expressed by 4.24 log [η] −0.470.

Here, the melt tension at 230 ° C. (M
S) uses a melt tension tester type 2 manufactured by Toyo Seiki Seisaku-Sho, Ltd. to convert polypropylene into 230
℃, melted polypropylene 2.095mm in diameter
From the nozzle at a speed of 20 mm / min into the air at 23 ° C. to form a strand.
The tension of the filamentous polypropylene at the time of drawing at a rate of / minute was measured and defined as a melt tension (MS).

The crystallization temperature of (B) the high melt tension polypropylene (PP2) required to achieve the object of the present invention is, as described above, a differential scanning calorimeter (DSC).
It is necessary that the crystallization temperature (Tc) and the melting point (Tm) measured by the above satisfy the relationship expressed by (Tc)> 0.784 × (Tm) −4.00, and more preferably (Tc). Tc)> 0.784 × (Tm) −3.00 Failure to satisfy this relationship will result in the loss of good moldability characteristics of the polypropylene composition of the present invention due to slow crystallization.

The crystallization temperature (Tc) and the melting point (Tm) of the polypropylene were raised from room temperature to 230 ° C. under a heating condition of 30 ° C./min using a DSC7 differential scanning calorimeter manufactured by Perkin Elmer. After holding at the same temperature for 10 minutes,
The temperature was lowered to -20 ° C at -20 ° C / min, and
After holding for 20 minutes, the temperature showing the maximum peak at the time of melting under a heating condition of 20 ° C./min was defined as a melting point (Tm). Further, after the melting point peak appeared, the temperature was continuously raised to 230 ° C. under the same conditions, and the temperature was maintained at the same temperature for 10 minutes.
The temperature was lowered to 50 ° C., and from 150 ° C., the temperature at which the maximum peak was reached during crystallization while the temperature was lowered at −5 ° C./min was defined as the crystallization temperature (Tc).

As described above, the high melt tension polypropylene (PP2), which is an essential component of the present invention, has a boiling xylene extraction residual ratio of 1% by weight or less, more preferably 0.6% or less.
It is necessary to be less than the weight%. If the extraction residual ratio is large, the moldability of the obtained polypropylene composition deteriorates, and it becomes extremely difficult to re-melt and reuse it after use as a molded article.

The boiling xylene extraction residue ratio was determined by placing 1 g of polypropylene in a 200-mesh wire net using a Soxhlet extractor, extracting the mixture with boiling xylene using 200 ml of p-xylene for 6 hours, and drying and weighing the extraction residue. It was calculated as (weight of extraction residue / weight before extraction) × 100%.

Further, (B) a high melt tension polypropylene (PP) which is an essential component of the polypropylene composition of the present invention.
In 2), it is a more preferable embodiment for the purpose of the present invention to satisfy any one of the following optional conditions in addition to the above four essential requirements. The optional conditions are as follows: (B) value of weight average molecular weight (Mw) / number average molecular weight (Mn) of linear crystalline polypropylene (PP3) used as a raw material in obtaining high melt tension polypropylene (PP2) (Q ) Is 7-30, or (B) the linear crystalline polypropylene (PP3) used as a raw material in obtaining the high melt tension polypropylene (PP2) has an intrinsic viscosity measured at 135 ° C. in tetralin. It comprises 1 to 50% by weight of a linear crystalline polypropylene (PP4) having [η] of 2.5 to 10 dl / g, and has an overall intrinsic viscosity [η] of 1.0 to 4.
0 dl / g linear crystalline polypropylene (PP
3). By adding these optional conditions, the effect of improving the melt tension of the obtained polypropylene composition becomes remarkable. If the value (Q) of the weight average molecular weight (Mw) / number average molecular weight (Mn), which is a measure of the molecular weight distribution, exceeds 30, the moldability is rather deteriorated and a gel is easily generated. Weight average molecular weight (Mw)
And the number average molecular weight (Mn) is measured by the method described above,
(Q) The value was calculated. In addition, the intrinsic viscosity of linear crystalline polypropylene (PP4) exceeds 10 dl / g,
If the ratio of (PP4) to (PP3) exceeds 50% by weight, the moldability is rather deteriorated, and a gel is easily generated.

The high melt tension polypropylene (B) which is an essential component of the polypropylene composition of the present invention (B)
The stereoregularity of the linear crystalline polypropylene (PP3) used as a raw material in obtaining 2) is not particularly limited, but in order for the obtained polypropylene composition to have high rigidity, a certain degree or more is required. It is desirable to have stereoregularity. Specifically, when a propylene homopolymer is used as the crystalline polypropylene (PP3), the stereoregularity (II) represented by the extraction residual ratio (% by weight) after 6 hours of extraction in boiling n-heptane is high. 80%
Above, preferably 90% or more, particularly preferably 95% or more of crystalline polypropylene is used. When a propylene-olefin random copolymer is used, crystalline polypropylene having a stereoregularity (II) of 20% or more, preferably 30% or more is used. The above description of stereoregularity is similarly applied to (A) crystalline polypropylene (PP1), which is another component of the polypropylene composition of the present invention.

Next, the high melt tension polypropylene (B) which is an essential component of the polypropylene composition of the present invention (PP)
The method of manufacturing 2) will be described. The crystalline polypropylene (PP3) used for producing (B) the high melt tension polypropylene (PP2) according to the present invention is the same as the other component of the polypropylene composition of the present invention described above (A) crystalline polypropylene (PP1). Known polypropylene obtained by a similar method can be used. Specifically, not only propylene homopolymers but also olefins other than propylene, for example, linear monoolefins such as ethylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, and the like, Branched chain monoolefins such as methylpentene-1 and 2-methylpentene-1, and random copolymers of styrene and propylene with propylene can also be used. When a copolymer is used, the olefin other than propylene is not limited to one type, and two or more olefins may be included. Specifically, a propylene-ethylene copolymer,
Propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer,
Examples thereof include propylene-4-methylpentene-1 copolymer, propylene-ethylene-butene-1 copolymer, and propylene-ethylene-4-methylpentene-1 copolymer. At this time, it is necessary that the content of olefin polymer units other than propylene in the copolymer is 10% by weight or less. 1
If it exceeds 0% by weight, a gel is easily generated in the obtained high melt tension polypropylene (PP2), which is outside the scope of the present invention.

As described above as a preferred embodiment of the present invention, when the (B) high melt tension polypropylene (PP2) is obtained, the value (Q) of weight average molecular weight (Mw) / number average molecular weight (Mn) is 7 as a raw material. Although the use of linear crystalline polypropylene (PP3) having a wide molecular weight distribution of from 30 to 30 is mentioned, a method for producing a crystalline polypropylene having such a wide molecular weight distribution is not particularly limited, and is known. Various methods are used. For example, a method of mixing two or more crystalline polypropylenes having different molecular weights, a method of polymerizing crystalline polypropylenes having different molecular weights in multiple stages, and a method of polymerizing propylene using a plurality or a specific catalyst component It can be manufactured by a method or the like.

In a similar preferred embodiment, the intrinsic viscosity [η] measured at 135 ° C. in tetralin as linear crystalline polypropylene (PP3) is 2.5 to 1
0 dl / g linear crystalline polypropylene (PP
The use of linear crystalline polypropylene (PP3) containing 1 to 50% by weight of 4) and having an overall intrinsic viscosity [η] of 1.0 to 4.0 dl / g is mentioned. The method for producing the crystalline polypropylene having such a specific high intrinsic viscosity is not particularly limited, and various known methods can be used. For example, in addition to a linear crystalline polypropylene (PP4) having an intrinsic viscosity [η] of 2.5 to 10 dl / g obtained by a known method, a polypropylene (PP5) having a different intrinsic viscosity separately obtained by a similar method is used. In a method of mixing or a method of polymerizing crystalline polypropylenes having different intrinsic viscosities in multiple stages, the intrinsic viscosity [η] can be determined at any one stage.
Can be obtained by including a step of polymerizing a linear crystalline polypropylene (PP4) having a molecular weight of 2.5 to 10 dl / g.

The form of the crystalline polypropylene (PP3) used in the present invention is not particularly limited, and may be in the form of powder, pellets, film, sheet, etc., for reasons of reaction efficiency and commercial production. Therefore, the powder in a state immediately after the completion of the polymerization step obtained by the above-described various methods and before pelletization is a preferable embodiment. The average particle size of the powder is 50 μm to 5 m.
m is used. It is preferable that the particle size is small in terms of reaction efficiency, but it is preferable that the particle size is large from the viewpoint of powder fluidity. Therefore, it is preferable to use one having a particle size suitable for the purpose.

In the present invention, crystalline polypropylene (P
Di-2-ethylhexyl peroxydicarbonate reacted with P3) is an organic peroxide having a decomposition temperature of 92 ° C. when the half-life is 1 minute and 60 ° C. when the half-life is 1 hour. Things. The use of other similar percarbonates having similar decomposition temperatures does not achieve the objectives of the present invention, as will be apparent from the examples below.

When adding and mixing with crystalline polypropylene (PP3), an inert solvent typified by a hydrocarbon solvent such as toluene, xylene, isoparaffin, octane, decane, etc., in order to handle and to make the reaction uniform. It is convenient to use one diluted in water. The concentration of di-2-ethylhexyl peroxydicarbonate in the solvent is about 10 to 90% by weight.

The reaction between crystalline polypropylene (PP3) and di-2-ethylhexyl peroxydicarbonate in the method of the present invention is carried out first in a reaction vessel under an inert gas atmosphere such as nitrogen or argon. -2-Ethylhexyl peroxydicarbonate is added and mixed. The temperature at this time is desirably 40 ° C. or less and 0 ° C. or more. In addition, it is desirable to stir so as to sufficiently mix. Crystalline polypropylene (PP
3) 1 to 10 mmol, preferably 2 to 10 mmol per 100 g. If the amount used is small, the effect of improving the final polypropylene composition is insufficient, and if the amount is too large, not only the effect cannot be expected to improve, but also an odor remains, and an unstable polypropylene composition having a large aging deterioration turn into.

Mixed crystalline polypropylene (PP
3) and di-2-ethylhexyl peroxydicarbonate are subsequently reacted in an inert gas atmosphere in a reaction vessel, optionally with stirring, at a temperature of 70 to 150 ° C, preferably 75 to 140 ° C. The reaction is carried out for 5 minutes to 5 hours, preferably for 10 minutes to 3 hours.

After the reaction, the reaction product is taken out of the reaction vessel, further melt-kneaded, and then cut into granules to obtain pellets, thereby obtaining (B) a high melt tension polypropylene (PP2) which is an essential component of the composition of the present invention. . For the melt kneading, a known melt kneading method is used. For example, using a single-screw extruder, a twin-screw extruder, an extruder combining these and a gear pump, a Brabender, a Banbury mixer, or the like, at a temperature equal to or higher than the melting point of polypropylene for about 10 seconds to 1 hour, preferably 20 seconds to 30 hours. Melt and knead for about a minute. By melt-kneading, the crystallization temperature rises remarkably, and the feature of (B) high melt tension polypropylene (PP2), which is an essential component of the present invention, appears. The crystallization temperature in the powder before the melt-kneading is the same as that before the reaction or only slightly increased.

In one embodiment of the present invention, it is possible to wash with an inert solvent if necessary in a powder state before melt-kneading, then dry and then melt-knead.

At the time of melt-kneading, an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, a lubricant, a flame retardant, an anti-blocking agent, a coloring agent, an inorganic or organic Various additives such as a filler can be blended.

Although the above method can also provide (B) the high melt tension polypropylene (PP2) used in the present invention, after the reaction is completed and before the melt-kneading, the reaction product is continuously treated under an inert gas atmosphere. Under stirring conditions according to
Post-heating at 100 to 150 ° C. is a desirable embodiment of the present invention. The processing time is 10 minutes to 2 hours, preferably 15 minutes to 1 hour. By the post-heating treatment, the reaction efficiency is increased, the odor of the finally obtained polypropylene composition is further reduced, and a stabilized polypropylene composition with little change over time is obtained.

(B) used in the present invention by the method described above
A high melt tension polypropylene (PP2) is obtained, which must have the characteristics already mentioned. Unless these characteristics are satisfied, the object of the present invention cannot be achieved.

The thus obtained (B) high melt tension polypropylene (PP2) is mixed and / or melt-kneaded with the (A) crystalline polypropylene (PP1) obtained by a known method as described above. A polypropylene composition is obtained. Various embodiments can be considered as a method for producing the composition of the present invention. For example, a method of mixing a pellet-like (A) crystalline polypropylene (PP1) and a pellet-like (B) high melt tension polypropylene (PP2), Pellets (A) crystalline polypropylene (PP1) and pellets (B) high melt tension polypropylene (PP2)
, Melt-kneading and pelletizing, powder-forming (A) crystalline polypropylene (PP1) and pellet-forming (B) high melt tension polypropylene (PP2) after melt-kneading, and powdering (A) A method in which the crystalline polypropylene (PP1) and the powdery (B) high melt tension polypropylene (PP2) precursor before melt-kneading are melt-kneaded and then pelletized. The method of (1) uses a powdery (B) high melt tension polypropylene (PP2) precursor before melt kneading, but melt kneading is carried out at the stage of producing the composition, so that (B) high melting Tensile polypropylene (PP2) is manufactured,
It is within the scope of the present invention. In addition, as described above, the pelletized form is usually the polypropylene resin of the present invention,
The polypropylene resin pellets of the present invention are used for various molded articles.
1) and (B) high melt tension polypropylene (PP2) or powdery (B) high melt tension polypropylene (P
P2) It is also possible to form a molded product by molding the precursor immediately after melt-kneading.

The composition ratio of (A) crystalline polypropylene (PP1) and (B) high melt tension polypropylene (PP2) in the polypropylene composition of the present invention is not particularly limited, but is determined from the synergistic effect of the effects of the present invention. (A)
For 100 parts by weight of crystalline polypropylene (PP1),
(B) 1 part by weight of high melt tension polypropylene (PP2)
900 parts by weight are preferred.

In the process of producing the polypropylene composition of the present invention, when melt-kneading, an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, a lubricant, Various additives such as a flame retardant, an anti-blocking agent, a coloring agent, and an inorganic or organic filler can be blended.

The polypropylene composition of the present invention thus obtained has an extremely high melt tension and crystallization temperature, is excellent in rigidity and moldability, and can be used again as a molded article and then re-melted for recycling. Because, is particularly suitable for hollow molding, foam molding, extrusion molding,
Not limited to the molding field, various containers such as hollow containers, films, sheets, by injection molding, T-die molding, thermoforming, etc.
It can be used for various molded products such as pipes and fibers.

[0044]

Next, the present invention will be described specifically with reference to examples. Definitions of terms used in Examples and Comparative Examples and measurement methods are as follows. (1) Intrinsic viscosity: [η], measured by the method described above.
(Unit: dl / g) (2) Weight average molecular weight: (Mw), measured by the method described above. (3) Number average molecular weight: (Mn), measured by the method described above. (4) Branching degree index: (g), measured by the method described above. (5) Melt tension: (MS) was measured by the method described above. (Unit: gf) (6) Melting point: (Tm) was measured by the method described above.
(Unit: ° C) (7) Crystallization temperature: (Tc), measured by the method described above. (Unit: ° C) (8) Rigidity: A JIS type test piece was prepared from a polypropylene pellet at a molten resin temperature of 230 ° C and a mold temperature of 50 ° C using an injection molding machine, and the test piece was subjected to a humidity of 50%.
%, At room temperature of 23 ° C. for 72 hours.
The flexural modulus was measured according to 7230. (Unit: k
gf / cm ² )

Example 1 After replacing the reactor equipped with a stirrer with a stirrer with nitrogen gas, Example 1 in JP-B-59-28573 was used.
The titanium trichloride composition obtained by the method described in the above, and diethyl aluminum chloride in an amount of 3 mol per mol of titanium in the titanium trichloride composition, and p as a third component
-Slurry polymerization of propylene in n-hexane in the presence of hydrogen, a molecular weight controller, using a catalyst in which methyl toluate is combined with 0.8 mole per 1 mole of titanium in the titanium trichloride composition. The intrinsic viscosity [η] was 1.68 dl / g and the weight average molecular weight (Mw) /
10 kg (PP3) of a crystalline propylene homopolymer powder having a number average molecular weight (Mn) value (Q) of 9.5, a stereoregularity (II) of 98%, and an average particle size of 140 μm were added. Then, the operation of evacuating the reactor and supplying nitrogen gas to atmospheric pressure was repeated 10 times.
0.35 mol of di-2-ethylhexyl peroxydicarbonate by weight was added and mixed. Subsequently, the temperature in the reactor was increased to 120 ° C., and the reaction was performed at the same temperature for 30 minutes. After the reaction time has elapsed, the temperature in the reactor is further increased to 135 ° C.
And a post-treatment was performed at the same temperature for 30 minutes. After the post-treatment, the reactor was cooled to room temperature, and then opened to obtain a powdery high melt tension polypropylene (PP2) precursor. When the melting point (Tm) and the crystallization temperature (Tc) of the polypropylene were measured, they were 163.7 ° C., 1
22.4 ° C. Subsequently, tetrakis [methylene-3- (3′-) was added to 100 parts by weight of the obtained powdery high melt tension polypropylene (PP2) precursor.
5′-Di-tert-butyl-4′-hydroxyphenyl) propionate], 0.1 part by weight of methane and 0.1 part by weight of calcium stearate are mixed, and the mixture is extruded using an extrusion granulator having a screw diameter of 40 mm. Granulated at 230 ° C and pelletized high melt tension polypropylene (PP2)
I got The physical properties of the pellets were evaluated and measured. As a result, the branching index was 0.99, and the intrinsic viscosity [η] was 1.6.
7 dl / g, melt tension (MS) 11.0 gf, melting point (Tm) 163.6 ° C., crystallization temperature (Tc) 13
2.9 ° C., boiling xylene extraction residual ratio was 0.0% by weight. On the other hand, when obtaining the above-mentioned crystalline polypropylene (PP3), a catalyst using 0.01 mol of diethylene glycol dimethyl ether per 1 mol of titanium instead of methyl p-toluate as the third component of the catalyst, Propylene was slurry polymerized in the same manner as in the production of crystalline polypropylene (PP3) except that the amount of hydrogen and the amount of hydrogen were changed, and the intrinsic viscosity [η] was 1.68 dl.
/ G, weight average molecular weight (Mw) / number average molecular weight (Mn)
Of the propylene homopolymer having a value (Q) of 5.6, which was designated as (A) crystalline polypropylene (PP1) used in the present invention. Next, with respect to 100 parts by weight of the powdery (A) crystalline polypropylene (PP1), 25 parts by weight of a pellet-like high melt tension polypropylene (PP2),
0.1 parts by weight of tetrakis [methylene-3- (3′-5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane and 0.1% of calcium stearate.
One part by weight was mixed, and the mixture was granulated at 230 ° C. by using an extrusion granulator having a screw diameter of 40 mm to obtain a polypropylene composition of the present invention as pellets. Table 1 shows the results of evaluating and measuring various physical properties of the composition.

Examples 2, 3, 4, 5 and Comparative Example 1 In Example 1, when a polypropylene composition was obtained, the mixing ratio of (A) crystalline polypropylene (PP1) and high melt tension polypropylene (PP2) was shown. A polypropylene composition was obtained in the same manner as in Example 1 except that the composition was changed as shown in (1). Table 1 shows the results of evaluating and measuring various physical properties of the composition.

[0047]

[Table 1]

Comparative Example 2 In Example 1, a high melt tension polypropylene (PP
In the production of 2), the decomposition temperature when the half-life is 1 minute is 85 ° C. and the decomposition temperature when the half-life is 1 hour is 57 ° C. instead of di-2-ethylhexylperoxydicarbonate.
The reaction and post-treatment were carried out in the same manner as in Example 1 except that 0.35 mol of di-3-methoxybutylperoxydicarbonate, which was at 0 ° C, was granulated to obtain polypropylene pellets. A polypropylene composition was obtained in the same manner as in Example 1 except that the polypropylene was used instead of the high melt tension polypropylene (PP2). Table 2 shows the results of evaluating and measuring various physical properties of the composition.

Comparative Example 3 In Example 1, a high melt tension polypropylene (PP
In the production of 2), instead of di-2-ethylhexyl peroxydicarbonate, the decomposition temperature when the half-life is 1 minute is 93 ° C., and when the half-life is 1 hour, the decomposition temperature is 61.
The reaction and post-treatment were carried out in the same manner as in Example 1 except that 0.35 mol of diisopropyl peroxydicarbonate at a temperature of 0 ° C was used, followed by granulation to obtain polypropylene pellets. A polypropylene composition was obtained in the same manner as in Example 1 except that the polypropylene was used instead of the high melt tension polypropylene (PP2). Table 2 shows the results of evaluating and measuring various physical properties of the composition.

Comparative Example 4 In Example 1, a high melt tension polypropylene (PP
In the production of 2), the decomposition temperature when the half-life is 1 minute is 112 ° C. and the decomposition temperature when the half-life is 1 hour is 7 instead of di-2-ethylhexylperoxydicarbonate.
T-butyl peroxypivalate 0.35 at 3 ° C
After conducting the reaction and post-treatment in the same manner as in Example 1 except that the mole was used, the mixture was granulated to obtain polypropylene pellets. The polypropylene is made of high melt tension polypropylene (P
A polypropylene composition was obtained in the same manner as in Example 1 except that P2) was used instead of P2). Table 2 shows the results of evaluating and measuring various physical properties of the composition.

Example 6 Magnesium chloride-supporting titanium catalyst component and triethylaluminum obtained by the method described in Example 1 in JP-A-62-104812 were added in an amount of 200 mol per 1 mol of titanium in the titanium catalyst component. And two continuous gas-phase polymerization reactors connected in series using a catalyst in which diisopropyldimethoxysilane is combined as a third component with 20 mol per 1 mol of titanium in the titanium catalyst component. In the first-stage polymerization vessel, the intrinsic viscosity [η] of the polymer was 4.10 dl / g, and the first-stage polymerization was performed with respect to the total polymerization amount, while maintaining different hydrogen concentrations in the gas phase in each vessel. In the second-stage polymerization vessel, the intrinsic viscosity [η] of the polymer produced in the second-stage polymerization is 0.76 dl / g, which is one step with respect to the total polymerization amount. Eye weight Such that the amount is 70 wt%, propylene continuously for 2 Dankisho polymerizing, intrinsic viscosity [η] of 1.76dl /
g, a propylene-homopolymer powder having an average particle size of 780 μm was obtained.
P3). Subsequently, in Example 1, the crystalline polypropylene (PP3) obtained by the above-mentioned method was used as the crystalline polypropylene (PP3) used as a raw material when producing the high melt tension polypropylene (PP2). A polypropylene pellet was obtained in the same manner as in Example 1 except that the reaction temperature with ethylhexyl peroxydicarbonate was set at 100 ° C. and the reaction time was set at 1 hour.
P2). The high melt tension polypropylene (PP2)
When various physical properties were evaluated and measured, the branching degree index was 0.98, the intrinsic viscosity [η] was 1.76 dl / g, the melt tension (MS) was 11.3 gf, and the melting point (Tm) was 163.7.
° C, the crystallization temperature (Tc) was 132.8 ° C, and the boiling xylene extraction residue was 0.0% by weight. On the other hand, when the above-mentioned crystalline polypropylene (PP3) is obtained, propylene is vapor-phase polymerized in the same manner except that one polymerization vessel is used and the amount of hydrogen is adjusted, so that the intrinsic viscosity [η] is increased. 1.
A propylene homopolymer powder of 76 dl / g was obtained and used in the present invention.
1). In Example 1, (A) crystalline polypropylene (PP1) obtained by the above method was used as (A) crystalline polypropylene (PP1), and (B) high melt tension polypropylene (PP2) was obtained by the above method. A polypropylene composition was obtained in the same manner as in Example 1, except that the obtained (B) high melt tension polypropylene (PP2) was used. Table 2 shows the results of evaluating and measuring various physical properties of the composition.

Comparative Example 5 Pellets were obtained by granulating (A) crystalline polypropylene (PP1) in the same manner as in Example 6, except that (B) the high melt tension polypropylene (PP2) was not used. Table 2 shows the results of evaluation and measurement of various physical properties of the pellets.

Example 7 In Example 1, (A) crystalline polypropylene (PP
Using the same catalyst as that used in the production of 1), propylene, ethylene and butene
1 was subjected to random copolymerization to have an ethylene unit content of 3.2% by weight, a butene-1 content of 2.5% by weight, an intrinsic viscosity [η] of 1.60 dl / g, and an average particle size of 190 μm.
Of propylene-ethylene-butene-1 random copolymer was obtained, and the random copolymer was used as (A) crystalline polypropylene (PP1) and crystalline polypropylene (PP3) used in the present invention. Subsequently, in Example 1, the crystalline polypropylene (PP3) obtained by the above-mentioned method was used as the crystalline polypropylene (PP3) used as a raw material when producing the high melt tension polypropylene (PP2). Except that the reaction temperature with ethylhexyl peroxydicarbonate was 85 ° C. and the reaction time was 45 minutes, a polypropylene pellet was obtained in the same manner as in Example 1 to obtain a high melt tension polypropylene (PP2) used in the present invention. The high melt tension polypropylene (PP
When various physical properties were evaluated and measured for 2), the branching index was 1.00, the intrinsic viscosity [η] was 1.60 dl / g, the melt tension (MS) was 6.2 g, and the melting point (Tm) was 135.5.
° C, the crystallization temperature (Tc) was 109.9 ° C, and the boiling xylene extraction residue was 0.1% by weight. In Example 1,
(A) The crystalline polypropylene (PP1) obtained by the above method is used as the crystalline polypropylene (PP1), and (B) the high melt tension polypropylene (PP)
A polypropylene composition was obtained in the same manner as in Example 1 except that (B) the high melt tension polypropylene (PP2) obtained by the above method was used as 2). Table 2 shows the results of evaluating and measuring various physical properties of the composition.

Comparative Example 6 A pellet was obtained by granulating (A) crystalline polypropylene (PP1) in the same manner as in Example 7, except that (B) the high melt tension polypropylene (PP2) was not used. Table 2 shows the results of evaluation and measurement of various physical properties of the pellets.

[0055]

[Table 2]

Example 8 In Example 6, propylene homopolymerization was carried out in the first stage using the same catalyst and production equipment as used in the production of crystalline polypropylene (PP3), followed by propylene polymerization in the second stage. And a propylene-ethylene block copolymer powder having an ethylene unit content of 7.5% by weight and an intrinsic viscosity [η] of 2.5 dl / g obtained by carrying out copolymerization of ethylene and ethylene. The copolymer was designated as (A) crystalline polypropylene (PP1) used in the present invention. Next, in Example 1, 25 parts by weight of the (B) high melt tension polypropylene (PP2) precursor powder obtained in the same manner as in Example 1 was used instead of pellet-like high melt tension polypropylene (PP2). A polypropylene composition of the present invention was obtained in the same manner as in Example 1, except that 100 parts by weight of the (A) crystalline polypropylene (PP1) obtained by the above method was used as the (A) crystalline polypropylene (PP1). Using a direct blow molding machine with a screw diameter of 65 mm, the above polypropylene composition was subjected to hollow molding of a kerosene tank with an inner volume of 20 l at a molding temperature of 230 ° C. and a mold temperature of 20 ° C., and the parison was drawn down. Thus, a homogeneous hollow molded article having no thickness unevenness was obtained.

Comparative Example 7 In Example 8, (B) was used as the polypropylene composition.
Except for using polypropylene pellets obtained without using high melt tension polypropylene (PP2) precursor powder, hollow molding was performed in the same manner as in Example 8,
The parison was greatly drawn down, and the hollow molding could not be performed.

[0058]

As is clear from the above-described embodiment,
The polypropylene composition of the present invention has an extremely high melt tension and crystallization temperature, is excellent in rigidity and moldability, and can be used in a wide range of applications limited to conventional polypropylene.

Claims (5)

(57) [Claims] (A) crystalline polypropylene (PP1)
100 parts by weight, (B) the branching index is substantially 1, and the melt tension (MS) at 230 ° C. and the intrinsic viscosity [η] measured in tetralin at 135 ° C. are log (M
S)> 4.24 log [η] −0.843, and the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC) are (Tc)> 0.784
× (Tm)-A polypropylene composition containing 1 to 900 parts by weight of high melt tension polypropylene (PP2) that satisfies the relationship represented by -4.00 and has a residual boiling xylene extraction ratio of 1% by weight or less. 2. High melt tension polypropylene (PP2)
However, under an inert gas atmosphere, 1 to 10 mmol of di-2-ethylhexyl peroxydicarbonate was added and mixed with 100 g of linear crystalline polypropylene (PP3), and mixed under a temperature condition of 70 to 150 ° C. Min ~ 3
After the reaction for a period of time, the degree of branching obtained by melt-kneading is substantially 1, and the melt tension (MS) at 230 ° C and the intrinsic viscosity [η] measured at 135 ° C in tetralin are shown. , Log (MS)> 4.24 × l
og [η] -0.843, and the crystallization temperature (T) measured by a differential scanning calorimeter (DSC).
c) and the melting point (Tm) are (Tc)> 0.784 × (T
m) The polypropylene composition according to claim 1, which is a high melt tension polypropylene (PP2) satisfying the relationship of -4.00 and having a boiling xylene extraction residual ratio of 1% by weight or less. 3. A linear crystalline polypropylene (PP)
3) is the weight average molecular weight (Mw) / number average molecular weight (M
The polypropylene composition according to claim 2, which is a linear crystalline polypropylene having a value (Q) of n) of 7 to 30. 4. A linear crystalline polypropylene (PP)
3) contains 1 to 50% by weight of a linear crystalline polypropylene (PP4) having an intrinsic viscosity [η] of 2.5 to 10 dl / g in tetralin measured at 135 ° C. Intrinsic viscosity [η] is 1.0 to 4.0 dl
/ G of a linear crystalline polypropylene (PP3). 5. A linear crystalline polypropylene (PP)
The polypropylene composition according to claim 2, 3 or 4, wherein 3) is a propylene homopolymer and / or a propylene-olefin random copolymer containing 10% by weight or less of an olefin polymerization unit other than propylene.