JPH06263823A - Polypropylene with high melt strength, its production and molded object - Google Patents

Abstract

PURPOSE:To obtain a polypropylene extremely high in melt strength and crystallization temp. and excellent in rigidity and moldability and to provide a method for producing the polypropylene and a molding made from the polypropylene. CONSTITUTION:This polypropylene is a linear crystalline polypropylene having a branching index of substantially 1 and satisfies the following equations: log(MS)>4.24Xlog[eta]-0.745 (wherein MS is the melt strength at 230 deg.C and [eta]is the intrinsic viscosity measured at 35 deg.C in tetralin) and (Tc)>0.784X(Tm)-4.00 (wherein Tc and Tm are the crystallization temp. and melting point, respectively, measured with a differential scanning calorimeter). It has a boiling-xylene-extractable content of 99wt.% or higher and a weight- average mol.wt./number-average mol.wt. ratio of 7-30. A method for producing this polypropylene and that for producing a molding from this polypropylene are included.

Description

Detailed Description of the Invention

[0001]

This invention relates to polypropylene having a high melt tension. More specifically, a polypropylene having a high melt tension and a high crystallization temperature, excellent rigidity and moldability, and having a high melt tension which can be reused by remelting after being used as a molded article, and a method for producing the same. And molded articles.

[0002]

2. Description of the Related Art Crystalline polypropylene has mechanical properties
It is widely used in various molding fields because it has excellent chemical resistance and is extremely useful in balance with economic efficiency. However, since the melt tension is low and the crystallization temperature is low, the moldability of hollow molding, foam molding, extrusion molding and the like is poor.

As a method for increasing the melt tension or crystallization temperature of crystalline polypropylene, a method of reacting crystalline polypropylene with an organic peroxide and a crosslinking aid in a molten state (Japanese Patent Laid-Open No. 59-93711). JP 61-
However, there is a problem that an odor remains in the modified polypropylene obtained by using the crosslinking aid. In addition, the improvement of the melt tension is insufficient, and if the addition amount of the organic peroxide and the crosslinking aid is increased to increase the melt tension, the gel will be generated and the moldability will deteriorate. It was also impossible to do.

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

[0005]

As described above, the polypropylene obtained by the method of the prior invention is insufficient in improving the melt tension and the 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 remelt and recycle.

The inventors of the present invention have solved the problems of the above-mentioned known invention, and have earnestly studied a polypropylene suitable for blow molding, foam molding, extrusion molding, and a method for producing the same. As a result, by reacting a specific organic peroxide with a polypropylene having a wide molecular weight distribution under specific conditions and further melt-kneading, polypropylene having a specific structure and properties is obtained, and the polypropylene is used as a molded article. The inventors have found that the problems of the known invention are solved and have reached the present invention.

As is clear from the above description, the object of the present invention is to have extremely high melt tension and crystallization temperature, excellent rigidity and moldability, and to be used as a molded product, then remelted and recycled. Another object is to provide polypropylene, a method for producing the same, and a molded product using the polypropylene.

[0008]

The present invention has the following constitutions (1) to (10). (1) A linear crystalline polypropylene having a branching index of substantially 1, and (A) a melt tension (MS) at 230 ° C. and an intrinsic viscosity [η] measured at 135 ° C. in tetralin. And log (MS)> 4.24 × log [η] −0.685, and (B) differential scanning calorimeter (DS).
Crystallization temperature (Tc) and melting point (Tm) measured by C)
Satisfy the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight (Mw) /
A polypropylene having a number average molecular weight (Mn) value (Q) of 7 to 30.

(2) The polypropylene according to (1) above, wherein the crystalline polypropylene is a propylene homopolymer.

(3) The polypropylene according to (1) above, wherein the crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene.

(4) Value (Q) of weight average molecular weight (Mw) / number average molecular weight (Mn) in an inert gas atmosphere
6 to 30, the linear crystalline polypropylene 10
1 to 10 mmol of di-2-ethylhexyl peroxydicarbonate was added and mixed per 0 g, and 70 to 150 ° C.
A linear crystalline polypropylene having a branching index of substantially 1, which is obtained by reacting for 10 minutes to 3 hours under the following temperature conditions and then melt-kneading, and (A)
Melt tension (MS) at 230 ° C and 1 in tetralin
The intrinsic viscosity [η] measured at 35 ° C. has a relationship expressed by log (MS)> 4.24 × log [η] −0.685, and (B) differential scanning calorimeter (DS).
Crystallization temperature (Tc) and melting point (Tm) measured by C)
Satisfy the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight (Mw) /
A method for producing polypropylene having a number average molecular weight (Mn) value (Q) of 7 to 30.

(5) The method according to (4) above, wherein the crystalline polypropylene is a propylene homopolymer.

(6) The method according to (4) above, wherein the crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene.

(7) After the reaction of crystalline polypropylene and di-2-ethylhexyl peroxydicarbonate, subsequently in an inert gas atmosphere at 100 to 150 ° C.
The method according to (4) above, which comprises post-treatment by heating for 10 minutes to 3 hours.

(8) A linear crystalline polypropylene having a branching index of substantially 1 and (A) 230
Melt tension (MS) at ℃ and 135 ℃ in tetralin
And the intrinsic viscosity [η] measured by the following: log (MS)> 4.24 × log [η] −0.685, and (B) differential scanning calorimeter (DS)
Crystallization temperature (Tc) and melting point (Tm) measured by C)
Satisfy the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight (Mw) /
A molded article made of polypropylene having a number average molecular weight (Mn) value (Q) of 7 to 30.

(9) The molded article according to (8) above, wherein the crystalline polypropylene is a propylene homopolymer.

(10) The molded article according to the above (8), wherein the crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene.

The constitution of the present invention will be described in detail below. In addition, the polypropylene of the present invention is not limited to propylene homopolymer, and contains 10 or more olefin polymer units other than propylene.
A propylene-olefin random copolymer containing less than or equal to wt% is also included, and the description of polypropylene is used in this sense.

The polypropylene of the present invention is a linear crystalline polypropylene having a branching index of substantially 1. The branching index indicates the degree of long chain branching. Generally, the following formula is used. Is defined. Branching index (g) = [η] Br / [η] Lin Here, [η] Br is the intrinsic viscosity of the branched polypropylene, and is the measured value [η] Obs of the polypropylene of the present invention in this specification. Also, [η] Lin is
In the method for producing the polypropylene of the present invention described later, obtained by the same method as the linear crystalline polypropylene obtained by a known method used as a raw material, the above [η]
Intrinsic viscosity of a linear crystalline polypropylene having the same weight average molecular weight as the Obs sample. The above intrinsic viscosity ratio indicates the degree of branching of the non-linear polymer, and is less than 1 when long chain branching is present.

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

The polypropylene of the present invention has a branching index of substantially 1 according to the above definition and measuring method, and does not have a long chain branched structure. It should be noted that substantially 1 means that even if there is a long chain branch, it is below the detection limit by the above method, and the range of statistical error when the same sample is repeatedly measured by the above method It includes the meaning of 1 inclusive. Therefore, the practical value is 0.
A value of about 95 to 1.05 is shown. Since the branching index is substantially 1, it has the same properties as the conventionally known linear polypropylene except for the characteristic properties of the polypropylene of the present invention described later, and thus the conventionally known linear polypropylene It has the feature that the molding method and equipment used for polypropylene can be used as it is.

Further, the polypropylene of the present invention has the following four essential requirements. That is, (A) the melt tension (MS) at 230 ° C. and the intrinsic viscosity [η] measured at 135 ° C. in tetralin are expressed by log (MS)> 4.24 log [η] −0.685, And (B) Differential scanning calorimeter (DS
Crystallization temperature (Tc) and melting point (Tm) measured by C)
Satisfy the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight (Mw) /
The characteristic is that the value (Q) of the number average molecular weight (Mn) satisfies 7 to 30.

As described above, the melt tension of polypropylene required to achieve the object of the present invention is as follows: melt tension (MS) at 230 ° C. and intrinsic viscosity [η] measured at 135 ° C. in tetralin. log (MS)> 4.24
The relationship represented by log [η] -0.685, and more preferably log (MS)> 4.24 log [η] -0.47.
It is necessary to have a relationship represented by 0.

Here, the melt tension (M
S) uses a melt tension tester type 2 manufactured by Toyo Seiki Seisakusho Co., Ltd.
Heated to ℃, melted polypropylene diameter 2.095mm
From the nozzle of No. 2 at a speed of 20 mm / min into the atmosphere of 23 ° C. to form a strand, and this strand is 3.14 m
The tension of the filamentous polypropylene at the time of taking it up at the speed of / min was measured and it was set as the melt tension (MS).

The crystallization temperature of polypropylene required to achieve the object of the present invention is, as described above, the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC). And (Tc)> 0.784 ×
It is necessary to satisfy the relationship represented by (Tm) -4.00, and more preferably the relationship represented by (Tc)> 0.784 × (Tm) -3.00. If this relationship is not met, the polypropylene of the present invention loses its good moldability characteristics due to slow crystallization.

The crystallization temperature (Tc) and melting point (Tm) were measured by using a DSC7 type differential scanning calorimeter manufactured by Perkin-Elmer Co., Ltd. and heating the polypropylene from room temperature to 30 ° C. under the conditions of 30 ° C./min. Then, after holding at the same temperature for 10 minutes,
The temperature is lowered to -20 ° C at -20 ° C / min, and 10 is kept at the same temperature.
After the temperature was maintained for a minute, the melting point (Tm) was defined as the temperature at which the maximum peak at the time of melting was obtained under the temperature rising condition of 20 ° C./min. Further, even after the melting point peak appears, the temperature is continuously raised to 230 ° C. under the same conditions, the temperature is kept at the same temperature for 10 minutes, and then at 1 ° C./minute
The temperature was lowered to 50 ° C., and from 150 ° C., the temperature showing the maximum peak during crystallization was set as the crystallization temperature (Tc) while decreasing the temperature at −5 ° C./min.

The polypropylene of the present invention is also required to have a boiling xylene extraction residual rate of 1% by weight or less, more preferably 0.6% by weight or less, as described above. If the extraction residual ratio is high, the moldability is deteriorated, and it is extremely difficult to remelt and recycle after use as a molded product.

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

Further, the polypropylene of the present invention needs to have a weight average molecular weight (Mw) / number average molecular weight (Mn) value (Q) of 7 to 30, which is a measure of the molecular weight distribution. When the molecular weight distribution (Q) is less than 7, the melt tension is insufficiently improved, and when it exceeds 30, the moldability is rather deteriorated and gel is apt to be generated. Weight average molecular weight (M
w) and the number average molecular weight (Mn) were measured by the method described above, and the (Q) value was calculated.

In addition to the above characteristics, the polypropylene of the present invention has a crystallinity of 10 measured by an X-ray diffraction method.
% Or more, the intrinsic viscosity [η] measured at 135 ° C. in tetralin is 0.5 to 5 dl / g, particularly preferably 0.7 to 4 dl / g, and the weight average molecular weight (Mw) is 8
It has the additional characteristic of 10,000 to 1.1 million, particularly preferably 120,000 to 900,000.

Next, a method for producing the above-mentioned polypropylene of the present invention will be described. The crystalline polypropylene used for producing the polypropylene of the present invention has a weight average molecular weight (Mw) / number average molecular weight (Mn) value (Q) of 7 to 30 which is a measure of the molecular weight distribution from the effect of improving the melt tension.
It is necessary to have a broad molecular weight distribution which is
Further, it is a crystalline polypropylene having a crystallinity of 10% or more as measured by an X-ray diffraction method, and preferably has an intrinsic viscosity [η] measured at 135 ° C. in tetralin of 0.5 to
5 dl / g, particularly preferably 0.7 to 4 dl / g is desirable from the viewpoint of moldability. Further, 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,
Branched chain monoolefins such as 4-methylpentene-1 and 2-methylpentene-1 as well as random copolymers of styrene and propylene can be used. When the copolymer is used, the olefin other than propylene is not limited to one type, and may contain two or more types. Specifically, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer, propylene-
4-methylpentene-1 copolymer, propylene-ethylene-butene-1 copolymer, propylene-ethylene-4-
Examples include methyl pentene-1 copolymer and the like. At this time,
The number of olefin polymer units other than propylene in the copolymer is 1
It should be 0% by weight or less. If it exceeds 10% by weight, gel is likely to occur in the obtained polypropylene, which is outside the scope of the present invention.

The method for producing crystalline polypropylene having such a wide molecular weight distribution is not particularly limited, and various known methods can be 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, a method of polymerizing propylene using a plurality of or specific catalyst components It can be manufactured by a method or the like. At this time, as a form of polymerizing propylene, slurry polymerization in which propylene is polymerized in an inert solvent, bulk polymerization in which propylene itself is a solvent, gas phase polymerization in a gas phase mainly composed of propylene gas, and further It can be obtained by a known method combining these.

The form of the crystalline polypropylene used in the present invention is not particularly limited, and powders, pellets, films, sheets and the like may be used.
For reasons of reaction efficiency and commercial production, a powder obtained by the above-mentioned various methods in a state immediately after the completion of the polymerization step and before being pelletized is a preferable form. The average particle size of the powder is about 50 μm to 5 mm. In terms of reaction efficiency, a smaller particle size is preferable, but a larger particle size is preferable from the viewpoint of powder fluidity, so it is preferable to use a particle size suitable for the purpose.

The di-2-ethylhexyl peroxydicarbonate to be reacted with the crystalline polypropylene in the present invention has a decomposition temperature of 92 ° C. when the half-life is 1 minute and a decomposition temperature when the half-life is 1 hour. It is an organic peroxide showing 60 ° C. As will be apparent from the examples described below, the use of similar percarbonates having similar decomposition temperatures does not achieve the object of the present invention.

When added to and mixed with the crystalline polypropylene, it is diluted with an inert solvent typified by a hydrocarbon solvent such as toluene, xylene, isoparaffin, octane and decane for handling and uniform reaction. It is convenient to use one. The concentration of di-2-ethylhexyl peroxydicarbonate in the solvent is about 10 to 90% by weight.

The reaction between the crystalline polypropylene and di-2-ethylhexyl peroxydicarbonate in the method of the present invention is carried out by first di-crystallizing the crystalline polypropylene in an inert gas atmosphere such as nitrogen or argon in a reaction vessel.
-Add and mix ethylhexyl peroxydicarbonate. The temperature at this time is preferably 40 ° C. or lower and 0 ° C. or higher.
Further, it is desirable to stir so that they are sufficiently mixed.
The amount of addition is 1 per 100 g of crystalline polypropylene.
10 to 10 millimole is preferable, and 2 to 10 millimole is particularly preferable. If the amount used is small, the effect of reforming is insufficient,
Further, if the amount is too large, not only the effect cannot be expected to be improved, but also odor remains, and the polypropylene becomes unstable with great deterioration over time.

Mixed crystalline polypropylene and di-
2-Ethylhexyl peroxydicarbonate is subsequently added to 70-150 ° C., preferably 75-150 ° C. under an inert gas atmosphere in a reaction vessel and optionally under stirring conditions.
At a temperature of ~ 140 ° C for 5 minutes to 5 hours, preferably 10
React for ~ 3 hours.

After the reaction, the polypropylene of the present invention is obtained by taking out from the reaction vessel and further melt-kneading. A known melt-kneading method is used for the melt-kneading. For example, using a single-screw extruder, a twin-screw extruder, an extruder combining these with a gear pump, a Brabender, a Banbury mixer, etc.
Melt-kneading is carried out at a temperature not lower than the melting point of polypropylene for about 10 seconds to 1 hour, preferably about 20 seconds to 30 minutes. By melt-kneading, the crystallization temperature rises remarkably, and the characteristics of the polypropylene of the present invention appear. The crystallization temperature of the powder before melt-kneading is the same as that before the reaction or only slightly increases.

After the melt-kneading, it is usually cut into granules and made into pellets for use in various molded articles, but it is also possible to process them immediately after the melt-kneading to obtain molded articles. In addition,
In the powder state before melt-kneading, it is possible to wash with an inert solvent, if necessary, and then dry and then melt-knead.

In the melt-kneading, if necessary, before heating and melting, an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, a lubricant, a flame retardant, an anti-blocking agent, a coloring agent,
Various additives such as an inorganic or organic filler can be blended.

Although the polypropylene of the present invention can be obtained by the above-mentioned method, after the reaction is completed and before melt-kneading, the reaction product is continuously heated under an inert gas atmosphere under a stirring condition, if necessary, at 100 to 100%. A post-heat treatment at 150 ° C is a desirable aspect of the present invention. Processing time is 1
It is suitable for 0 minutes to 2 hours, preferably 15 minutes to 1 hour. The post-heating treatment increases the reaction efficiency and
In addition to further reducing the odor of the obtained polypropylene, stabilized polypropylene with little change over time can be obtained.

The desired polypropylene of the present invention can be obtained by the above-mentioned method, and the polypropylene must have the characteristics described above. The object of the present invention cannot be achieved unless these characteristics are satisfied.

The polypropylene of the present invention thus obtained has extremely high melt tension and crystallization temperature, is excellent in rigidity and moldability, and can be reused by remelting after being used as a molded article. Therefore, it is particularly suitable for hollow molding, foam molding, extrusion molding, but is not limited to the molding field, and various containers such as hollow containers by injection molding, T-die molding, thermoforming, films, sheets, pipes, It can be used for various molded articles such as fibers.

[0044]

The reaction mechanism for obtaining the polypropylene of the present invention is unknown at the present time, but the radicals generated from di-2-ethylhexyl peroxydicarbonate do not interact with polypropylene having a wide molecular weight distribution. It is presumed that, by causing the action and further melt-kneading, the melting behavior and the crystallization behavior characteristic of the polypropylene of the present invention, which are not found in known polypropylene, are exhibited.

[0045]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Definitions of terms and measurement methods used in Examples and Comparative Examples 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 index: (g), measured by the method described above. (5) Melt tension: (MS), measured by the method described above. (Unit: gf) (6) Melting point: (Tm), measured by the method described above.
(Unit: ° C) (7) Crystallization temperature: (Tc), which was measured by the method described above. (Unit: ° C) (8) Rigidity: A polypropylene type test piece was prepared from polypropylene pellets with an injection molding machine at a molten resin temperature of 230 ° C and a mold temperature of 50 ° C.
%, After leaving it in a room at room temperature of 23 ° C for 72 hours, JISK
The flexural modulus was measured according to 7230. (Unit: k
gf / cm ² )

Example 1 After replacing a 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 as described above, further 3 moles of diethylaluminum chloride to 1 mole of titanium in the titanium trichloride composition, and p as the third component.
-Slurry polymerization of propylene in n-hexane in the presence of hydrogen, which is a molecular weight controlling agent, using a catalyst in which 0.8 mol of methyl toluate is combined with 1 mol of titanium in the titanium trichloride composition. The obtained intrinsic viscosity [η] was 1.68 dl / g, and the weight average molecular weight (Mw) /
10 kg of a propylene homopolymer powder having a number average molecular weight (Mn) value (Q) of 9.5 and an average particle size of 140 μm was added. Then, after the inside of the reactor was evacuated and the operation of supplying nitrogen gas to atmospheric pressure was repeated 10 times, di-2-ethylhexyl having a concentration of 70% by weight in a toluene solution at 25 ° C. was stirred at 25 ° C. under a nitrogen gas atmosphere. 0.35 mol of peroxydicarbonate was added and mixed. Subsequently, the temperature inside the reactor was raised to 120 ° C., and the reaction was carried out at the same temperature for 30 minutes. After the reaction time has elapsed, the temperature inside the reactor is further increased to 13
The temperature was raised to 5 ° C. and 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 polypropylene. The melting point (Tm) and crystallization temperature (Tc) of the polypropylene were measured and found to be 163.7 ° C and 122.4 ° C, respectively. Subsequently, with respect to 100 parts by weight of the obtained polypropylene, 0.1 parts by weight of tetrakis [methylene-3- (3′-5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane and a steer. Calcium phosphate 0.1
Parts by weight were mixed, and the mixture was granulated at 230 ° C. using an extruder having a screw diameter of 40 mm to obtain the polypropylene of the present invention as pellets. When various physical properties of the pellet were evaluated and measured, the crystallinity by an X-ray diffraction method was 67%, and the weight average molecular weight (Mw) / number average molecular weight (Mn) was 9.8. The other results are shown in Table 1.

Examples 2 and 3 Polypropylene was prepared in the same manner as in Example 1 except that the intrinsic viscosity of polypropylene used in the reaction and the reaction conditions and post-treatment conditions were changed as shown in Table 1. Pellets were obtained.

Comparative Examples 1 to 3 Granulation was carried out in the same manner as in Example 1 without reacting the propylene homopolymer used in the reaction with di-2-ethylhexyl peroxydicarbonate in Examples 1 to 3, Pellets were obtained.

Comparative Example 4 In obtaining polypropylene used as a raw material in Example 1, 0.01 mol of diethylene glycol dimethyl ether was used as the third component of the catalyst in place of methyl p-toluate, based on 1 mol of titanium. Was used, and propylene was slurry-polymerized in the same manner as in Example 1 except that the amount of hydrogen was changed, and the intrinsic viscosity [η] was 1.68 dl / g and the weight average molecular weight (Mw) /
A propylene homopolymer powder having a number average molecular weight (Mn) value (Q) of 5.6 was obtained. 10 kg of the polypropylene
After reacting with di-2-ethylhexyl peroxydicarbonate in the same manner as in Example 1 except that was used as the raw material polypropylene, granulation was performed to obtain polypropylene pellets.

The above Examples 1 to 3 and Comparative Examples 1 to 4
The conditions and results are shown in Table 1.

[0051]

[Table 1]

Example 4 In Example 1, as polypropylene used in the reaction, Example 1 in JP-A-62-104812 was used.
Magnesium chloride-supporting titanium catalyst component obtained by the method described above and triethylaluminum are 200 mols per 1 mol of titanium in the titanium catalyst component, and diisopropyldimethoxysilane as the third component is 1 mol of titanium in the titanium catalyst component. In the n-hexane, three continuous polymerization reactors connected in series were used with a catalyst in which 20 moles were combined with each other, while maintaining different hydrogen concentrations in the gas phase in each polymerization reactor. Intrinsic viscosity [η] obtained by continuous multi-stage polymerization of propylene at 1.52d
1 / g, weight average molecular weight (Mw) / number average molecular weight (M
Polypropylene pellets were obtained in the same manner as in Example 1 except that 10 kg of a propylene homopolymer powder having a value (Q) of n) of 12.4 and an average particle size of 750 μm was used.

Comparative Example 5 In Example 4, the propylene homopolymer used in the reaction was granulated in the same manner as in Example 4 without reacting di-2-ethylhexyl peroxydicarbonate to obtain pellets. .

Comparative Example 6 Slurry polymerization of propylene was carried out in the same manner as in Example 4 except that one polymerizer was used when the polypropylene used as a raw material was obtained and the amount of hydrogen was adjusted. And the intrinsic viscosity [η] is 1.52 dl / g,
A propylene homopolymer powder having a weight average molecular weight (Mw) / number average molecular weight (Mn) value (Q) of 5.0 was obtained. After reacting with di-2-ethylhexyl peroxydicarbonate in the same manner as in Example 4 except that 10 kg of the polypropylene was used as the raw material polypropylene, granulation was performed to obtain polypropylene pellets.

Comparative Example 7 In Example 4, instead of di-2-ethylhexyl peroxydicarbonate, the decomposition temperature when the half-life was 1 minute was 85 ° C., and the decomposition temperature when the half-life was 1 hour. Is 57
The reaction was carried out in the same manner as in Example 4 except that di-3-methoxybutyl peroxydicarbonate was used,
Post-treatment was performed.

Comparative Example 8 In Example 4, instead of di-2-ethylhexyl peroxydicarbonate, the decomposition temperature when the half-life was 1 minute was 93 ° C., and the decomposition temperature when the half-life was 1 hour. Is 61
The reaction and post-treatment were carried out in the same manner as in Example 4 except that diisopropyl peroxydicarbonate, which was at 0 ° C., was used.

Comparative Example 9 In Example 4, instead of di-2-ethylhexyl peroxydicarbonate, the decomposition temperature when the half-life was 1 minute was 112 ° C., and the decomposition temperature when the half-life was 1 hour. Is 7
Reaction and post-treatment were carried out in the same manner as in Example 4 except that t-butylperoxypivalate at 3 ° C was used.

Table 2 shows the conditions and results of Example 4 and Comparative Examples 5 to 9 described above.

[0059]

[Table 2]

Example 5 In Example 4, the same catalyst as in Example 4 was used as the polypropylene to be used in the reaction, and the high-molecular weight polymer was bulk polymerized in the first stage, followed by vapor phase in the same polymerization vessel. The ethylene unit content was 0.2% by weight and the intrinsic viscosity [η] was 1.70 dl /, which was obtained by carrying out the copolymerization of propylene and ethylene under the polymerization conditions for producing a low molecular weight polymer by polymerization. g, weight average molecular weight (Mw) /
Polypropylene pellets were obtained in the same manner as in Example 4 except that 10 kg of a propylene-ethylene random copolymer powder having a number average molecular weight (Mn) value (Q) of 8.0 and an average particle size of 780 μm was used.

Comparative Example 10 In Example 5, the propylene-ethylene random copolymer used as the raw material was granulated in the same manner as in Example 5 without reacting with di-2-ethylhexyl peroxydicarbonate, and pelletized. Got

Comparative Example 11 In Example 5, except that polypropylene was used as a raw material, bulk polymerization was carried out in one step without carrying out polymerization in multiple steps, and ethylene amount and hydrogen amount were adjusted. Was obtained by copolymerizing propylene and ethylene in the same manner as in Example 5. The ethylene unit content was 0.2% by weight and the intrinsic viscosity [η] was 1.72 d.
1 / g, weight average molecular weight (Mw) / number average molecular weight (M
A propylene-ethylene random copolymer powder having a value (n) of n) of 4.8 was obtained. 10 kg of the polypropylene
After reacting with di-2-ethylhexyl peroxydicarbonate and granulating in the same manner as in Example 5 except that was used as a raw material polypropylene, polypropylene pellets were obtained.

Example 6 In Example 4, as the polypropylene used in the reaction, the same catalyst as in Example 4 was used, and the two were connected in series.
Using a continuous gas phase polymerizer, the copolymerization of propylene, ethylene and butene-1 is continuously carried out by gas phase polymerization in two stages while maintaining different hydrogen concentrations in the gas phase in each polymerizer. The ethylene unit content was 3.2% by weight, the butene-1 unit content was 2.5% by weight, the intrinsic viscosity [η] was 1.60 dl / g, and the weight average molecular weight ( Mw) / number average molecular weight (Mn) value (Q) 7.8, propylene having an average particle size of 770 μm
Ethylene-butene-1 random copolymer powder 10k
Polypropylene pellets were obtained in the same manner as in Example 1 except that g was used and the reaction conditions and the post-treatment conditions were changed as shown in Table 3.

Comparative Example 12 In the same manner as in Example 5, except that the propylene-ethylene-butene-1 random copolymer used as a raw material was not reacted with di-2-ethylhexyl peroxydicarbonate in Example 6, Granules were obtained to obtain pellets.

Comparative Example 13 In Example 6, when the polypropylene used as a raw material was obtained, the gas phase polymerization was carried out in one step without carrying out the polymerization in multiple steps, the amount of ethylene, the amount of butene-1 and the amount of hydrogen. The ethylene unit content was 3.2% by weight and the butene-1 unit content was obtained by copolymerizing propylene, ethylene and butene-1 in the same manner as in Example 5 except that the concentration was adjusted. Is 2.5% by weight, intrinsic viscosity [η] is 1.60 dl / g, weight average molecular weight (Mw) /
A propylene-ethylene-butene-1 random copolymer powder having a number average molecular weight (Mn) value (Q) of 4.1 was obtained. After reacting with di-2-ethylhexyl peroxydicarbonate and granulating in the same manner as in Example 6 except that 10 kg of the polypropylene was used as the raw material polypropylene, polypropylene pellets were obtained.

The above Examples 5 and 6 and Comparative Examples 10 to 1
Table 3 shows the conditions and results of No. 3.

[0067]

[Table 3]

Example 7 100 parts by weight of polypropylene powder obtained by reacting raw material polypropylene with di-2-ethylhexyl peroxydicarbonate in the same manner as in Example 1 was added with tetrakis [methylene-3- (3'-5 ']. -Di-t-butyl-4 '
-Hydroxyphenyl) propionate] methane 0.1
1 part by weight, 0.1 part by weight of calcium stearate, and 0.1 part by weight of talc as a foam nucleating agent were mixed, and the mixture was supplied to a single-screw extruder set to a screw diameter of 65 mm and an extruder temperature of 230 ° C. Then, 22 parts by weight of 1,1,2,2-tetrafluorodichloroethane was injected as a foaming agent from the middle of the extruder. Mounted on the extruder,
Using a nozzle-shaped mold with a diameter of 5 mm, mold temperature 155 ℃
Was extruded and foamed. The surface of the obtained foam was smooth, and abnormal cells were not observed, and the cells had uniform cells.

Comparative Example 14 In place of the polypropylene powder obtained by reacting di-2-ethylhexyl peroxydicarbonate in Example 7, the propylene homopolymer used as a raw material when obtaining the polypropylene powder was used as it was. When extrusion foam molding was carried out in the same manner except that the above was carried out, the obtained foam had an appearance defect due to outgassing and had large cavities, and was unsatisfactory for use.

Example 8 Propylene-ethylene random copolymer pellets obtained in the same manner as in Example 5 were subjected to extrusion sheeting at 260 ° C. using an extruder with a T-die and a screw diameter of 65 mm. A sheet having a thickness of 0.5 mm was obtained. Next, in order to evaluate the heat-vacuum formability of the sheet as a model, the sheet was fixed to a 40 cm square frame and heated at 210 ° C.
It was put in a thermostatic chamber of No. 2 and the behavior was observed. The sheet starts to hang down due to heating, and when it hangs down 31 mm,
The drooping stopped and the lower part rose. 20 after stopping drooping
After a lapse of a second, the sheet started to hang down again, and thereafter only drooped. It was found that the amount of drooping was small and the time until the start of re-dragging was long, which was as long as 20 seconds, and that the sheet had extremely excellent heat-vacuum formability.

Comparative Example 15 In Example 8, instead of the polypropylene of the present invention,
A sheet was obtained in the same manner except that the pellets of the propylene-ethylene random copolymer obtained in the same manner as in Comparative Example 11 were used. When the heating behavior of the sheet was observed in the same manner as in Example 8, it was found that the drooping stopped at 40 m.
m, and the time until the start of re-hanging was as short as 8 seconds, which was inferior to the vacuum molding by heating as compared with Example 8.

Example 9 In order to recycle the molded article of the present invention, in the same manner as in Example 1, many test pieces for flexural modulus measurement were prepared,
A polypropylene composition comprising 10% by weight of the crushed test piece obtained by subjecting the injection-molded test piece to a crusher and 90% by weight of polypropylene pellets obtained in the same manner as in Example 1 was directly blown with a screw diameter of 65 mm. Using a molding machine, a kerosene tank having an internal volume of 100 l was hollow-molded at a molding temperature of 230 ° C and a mold temperature of 20 ° C.
As for the parison, a uniform hollow molded product was obtained without drawdown and having uniform thickness.

Comparative Example 16 In Example 9, hollow molding was performed in the same manner as in Example 8 except that polypropylene pellets obtained in the same manner as in Comparative Example 1 were used as the polypropylene, but the parison was greatly drawn down. However, blow molding could not be performed.

Comparative Example 17 A blow molding was performed in the same manner as in Example 8 except that polypropylene pellets obtained in the same manner as in Comparative Example 4 were used as the polypropylene in Example 9, but the parison was drawn down. This resulted in an inhomogeneous hollow molded product with uneven thickness.

[0075]

As is apparent from the above-mentioned Examples and Comparative Examples, the polypropylene of the present invention has extremely high melt tension and crystallization temperature, excellent rigidity and moldability, and is limited to conventional polypropylene. It is possible to expand the field of application.

Claims (10)

[Claims] 1. A linear crystalline polypropylene having a branching index of substantially 1, and (A) a melt tension (MS) at 230 ° C. and an intrinsic viscosity measured at 135 ° C. in tetralin [A]. η] is a relationship expressed by log (MS)> 4.24 × log [η] −0.685, and (B) crystallization temperature (Tc) and melting point measured by a differential scanning calorimeter (DSC). (Tm) satisfies the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight ( Mw) / number average molecular weight (Mn)
Value (Q) of 7 to 30, polypropylene. 2. The polypropylene according to claim 1, wherein the crystalline polypropylene is a propylene homopolymer. 3. The polypropylene according to claim 1, wherein the crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene. 4. The value (Q) of weight average molecular weight (Mw) / number average molecular weight (Mn) is 7 in an inert gas atmosphere.
100 g of linear crystalline polypropylene that is ~ 30
1 to 10 mmol of di-2-ethylhexyl peroxydicarbonate was added and mixed, and the mixture was reacted under the temperature condition of 70 to 150 ° C. for 10 minutes to 3 hours and then melt-kneaded. A linear crystalline polypropylene having an index of substantially 1 and (A) the melt tension (MS) at 230 ° C. and the intrinsic viscosity [η] measured in tetralin at 135 ° C. MS)> 4.24 × log [η] −0.685, and (B) the crystallization temperature (Tc) and melting point (Tm) measured by a differential scanning calorimeter (DSC): Tc)> 0.784 × (Tm) −4.00 is satisfied, (C) boiling xylene extraction residual rate is 1 wt% or less, and (D) weight average molecular weight (Mw) / number average molecular weight ( Mn)
A method for producing a polypropylene having a value (Q) of 7 to 30. 5. The method according to claim 4, wherein the crystalline polypropylene is a propylene homopolymer. 6. The method according to claim 4, wherein the crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene. 7. After the reaction of crystalline polypropylene and di-2-ethylhexyl peroxydicarbonate, the method further comprises post-treatment by heating at 100 to 150 ° C. for 10 minutes to 3 hours in an inert gas atmosphere. Item 4. The method according to Item 4. 8. A linear crystalline polypropylene having a branching index of substantially 1, and (A) a melt tension (MS) at 230 ° C. and an intrinsic viscosity measured at 135 ° C. in tetralin [A]. η] is a relationship expressed by log (MS)> 4.24 × log [η] −0.685, and (B) crystallization temperature (Tc) and melting point measured by a differential scanning calorimeter (DSC). (Tm) satisfies the relationship represented by (Tc)> 0.784 × (Tm) −4.00, (C) boiling xylene extraction residual rate is 1% by weight or less, and (D) weight average molecular weight ( Mw) / number average molecular weight (Mn)
A molded article made of polypropylene having a value (Q) of 7 to 30. 9. The molded article according to claim 8, wherein the crystalline polypropylene is a propylene homopolymer. 10. The crystalline polypropylene is a propylene-olefin random copolymer containing 10% by weight or less of olefin polymerized units other than propylene.
The molded product described in.