JP3355816B2 - Manufacturing method and molded product of modified polypropylene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified polypropylene and a molded article. More specifically, the present invention relates to a method for producing a modified polypropylene having excellent melt tension and melt elasticity, and a molded article using the modified polypropylene obtained by the method.

[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 the like and is extremely useful in balance with economy.
However, since the melt tension is small, the moldability is inferior in fields such as hollow molding, foam molding, and extrusion molding.

As a method of increasing the melt tension 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-61-1986) −152754
However, the improvement of the melt tension is insufficient, and when the addition amount of the organic peroxide and the crosslinking assistant is increased to increase the melt tension, a gel is generated and the moldability is deteriorated.

[0004]

As described above, the polypropylene obtained by the method of the known invention is insufficient in improving the melt tension, and in addition, the amount of the organic peroxide and the amount of the crosslinking aid are increased in order to increase the melt tension. There is a problem in that when the number of particles increases, a gel is generated and the moldability deteriorates.

[0005] The present inventors have solved the problems of the above-mentioned known inventions, and have earnestly studied polypropylene suitable for hollow molding, foam molding, extrusion molding and the like, and a method for producing the same. As a result, the problems of the known invention can be solved by blending a very small amount of an organic peroxide and a crosslinking assistant into a polypropylene composition containing a specific amount of a high-viscosity polypropylene, followed by heat treatment, preferably by melt-kneading. This led to the present invention.

As is apparent from the above description, an object of the present invention is to provide a modified polypropylene having an extremely high melt tension and excellent moldability such as hollow molding, foam molding and extrusion molding, and a molded article using the polypropylene. To provide.

[0007]

The present invention has the following constitutions (1) to (4). (1) To 100 parts by weight of the crystalline polypropylene (PP1), 0.0005 to 0.5 parts by weight of an organic peroxide and at least one crosslinking aid selected from diacrylates, dimethacrylates, and triacrylates are used. .01-5.
In a method of producing a modified polypropylene (PP2) having a boiling xylene extraction residual ratio of 1% by weight or less by blending 0 parts by weight and heat-treating at 180 to 300 ° C, a crystalline polypropylene (PP1) in tetralin is used. The intrinsic viscosity [η] measured at 135 ° C. is 2.5 to 10
dl / g of crystalline polypropylene (PP3)
A method for producing a modified polypropylene, comprising using a crystalline polypropylene composition (PP4) containing 50% by weight and having an overall intrinsic viscosity [η] of 1.0 to 4.0 dl / g.

(2) The modified polypropylene has an intrinsic viscosity [η] of 2.5 d in tetralin measured at 135 ° C.
The method according to the above (1), which is 1 / g or less.

(3) 1 to 50% of crystalline polypropylene (PP3) having an intrinsic viscosity [η] of 2.5 to 10 dl / g in tetralin measured at 135 ° C. η] is 1.0 to 4.0 dl
/ G of the crystalline polypropylene composition (PP4), 0.0005 to 0.5 parts by weight of an organic peroxide and 0 or more crosslinking aids selected from diacrylates, dimethacrylates, and triacrylates. .01-5.0
A molded article using a modified polypropylene (PP2) having a boiling xylene extraction residual ratio of 1% by weight or less, obtained by blending parts by weight and heat-treating at 180 to 300 ° C.

(4) The modified polypropylene has an intrinsic viscosity [η] of 2.5 d in tetralin measured at 135 ° C.
The molded article according to the above (3), which is 1 / g or less.

The configuration and effect of the present invention will be described in detail below. The polypropylene used in the present invention includes not only a propylene homopolymer but also a propylene-olefin copolymer containing 40% by weight or less of olefin polymerization units other than propylene. Used.

The crystalline polypropylene (P) used in the present invention
As P1), the intrinsic viscosity [η] measured at 135 ^° C. in tetralin is 2.5 due to the effect of improving the melt tension.
Crystalline polypropylene (PP3) having a viscosity of 10 to 10 dl / g
It is necessary to use a crystalline polypropylene composition (PP4) containing 1 to 50% by weight and having an overall intrinsic viscosity [η] of 1.0 to 4.0 dl / g.
The intrinsic viscosity of crystalline polypropylene (PP3) is 2.5d
If it is smaller than 1 / g, the effect of improving the melt tension is low, and 1
If it is larger than 0 dl / g, a gel will be generated in the obtained polypropylene, which is outside the scope of the present invention. The ratio of the high-viscosity crystalline polypropylene (PP3) to the entire crystalline polypropylene composition (PP4) obtained by mixing one or more types of crystalline polypropylene (PP5) with the high-viscosity crystalline polypropylene (PP3) is 1 If the content is less than 50% by weight, the effect of improving the melt tension is low, and if it exceeds 50% by weight, a gel is generated in the obtained polypropylene or the processability deteriorates. Further, a crystalline polypropylene composition (PP
4) If the intrinsic viscosity as a whole is less than 1.0 dl / g, the impact strength of the obtained polypropylene is low, and
If it is greater than 0 dl / g, the processability of the resulting polypropylene will be poor.

The modified polypropylene (P) obtained by the present invention
P2) is an essential condition that the boiling xylene extraction residual ratio is 1% by weight or less. The polypropylene of the present invention has a boiling xylene extraction residual ratio of 1% by weight, which is a measure of the gel content.
It is necessary that the content is not more than 0.7% by weight, most preferably not more than 0.5% by weight. If the extraction residual ratio is large, the moldability deteriorates, and it becomes extremely difficult to re-melt and recycle 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 gauze using a Soxhlet extractor, extracting 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%.

The intrinsic viscosity [η] of the modified polypropylene (PP2) obtained in the present invention measured at 135 ^° C. in tetralin is 2.5 dl / g as described above.
It is more preferable that the content is less than the effect of improving the melt tension.

To achieve the object of the present invention, the melt tension of the modified polypropylene is preferably such that the melt tension at 230 ^° C. (MS) and the intrinsic viscosity [η] measured at 135 ^° C. in tetralin are log (log). MS)> 4.24 × lo
g [η] −0.409, more preferably log (MS)> 4.24 × log [η] −0.354
It is desirable that the relationship be expressed as follows.

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
It was heated to ^o C, the molten polypropylene diameter 2.095m
m at a speed of 20 mm / min into a 23 ^° C. atmosphere to form a strand.
The tension of the filamentous polypropylene when it was taken off at a speed of 4 m / min was measured and defined as the melt tension (MS).

Next, a method for producing the above-mentioned modified polypropylene (PP2) of the present invention will be described. As the crystalline polypropylene (PP1) used in the present invention, 135 ^° C.
Including 1 to 50% by weight of a crystalline polypropylene (PP3) having an intrinsic viscosity [η] of 2.5 to 10 dl / g measured in the above, the overall intrinsic viscosity [η] is 1.0 to 4.0.
0 dl / g crystalline polypropylene composition (PP
It is necessary to use 4), and it is desirable from the viewpoint of physical properties that the crystallinity measured by an X-ray diffraction method is 10% or more. These crystalline polypropylenes include a catalyst obtained by combining a transition metal compound catalyst component, an organometallic compound catalyst component containing a metal selected from Groups 1 to 3 of the periodic table, and, if necessary, an electron donor. It is a known crystalline polypropylene obtained by polymerizing propylene using the same.

Specifically, not only propylene homopolymer but also olefins other than propylene, for example, ethylene,
Butene-1, pentene-1, hexene-1, heptene-
1, a linear monoolefin such as octene-1, a branched monoolefin such as 4-methylpentene-1 or 2-methylpentene-1, a random copolymer of styrene and propylene, and a propylene copolymer. It is obtained by homopolymerization or random copolymerization of propylene with olefins other than propylene after copolymerization of propylene with a small amount of olefins other than propylene such that the content of olefins other than propylene is 3% by weight or less. A so-called block copolymer can also be used. When using a copolymer, the number of olefins other than propylene is not limited to one, but may be 2
Even if more than one kind is included, it can be accepted. In particular,
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-methylpentene-1 copolymer and the like. At this time, the content of olefins other than propylene in the copolymer is not particularly limited, but is preferably 40% by weight or less. If it exceeds 40% by weight, a gel is easily generated in the obtained polypropylene, which is outside the scope of the present invention.

As the transition metal compound catalyst component used in producing the above-mentioned crystalline polypropylene, a compound containing a transition metal selected from Groups 3 to 8 of the periodic table can be mentioned. Include Ti, Zr, Hf, N
Compounds containing one or more transition metals selected from b, Ta, Cr and V are included.

Examples of such a transition metal compound catalyst component include known olefin polymerization catalyst components. Specific examples include a titanium compound, a magnesium compound, and, if necessary, oxygen and nitrogen in the molecule. , Phosphorus, a supported catalyst component obtained by contacting an electron donor containing at least one of sulfur, titanium, magnesium, halogen and, if necessary, an electron donor, and reduction of titanium tetrachloride. And a titanium trichloride-based catalyst component obtained by contacting the obtained titanium trichloride composition with a tetravalent titanium compound and / or an electron donor. Further, a metallocene compound obtained by contacting a cyclopentadienyl compound with a transition metal compound can also be used. As the metallocene compound, an inorganic compound such as SiO ₂ or Al ₂ O ₃ or a compound supported on a polymer compound such as polyethylene or polypropylene can be used.

Examples of the organometallic compound catalyst component containing a metal selected from Groups 1 to 3 of the periodic table include trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, aluminoxane and the like. Are preferably used.

The electron donor used if necessary may be any one of oxygen, nitrogen, phosphorus and sulfur in the molecule.
Examples include compounds containing at least one or more species, and specifically, organosilicon compounds having an Si-O bond, esters, ethers, and the like are preferably used.

Using a catalyst obtained by combining the above-described transition metal compound catalyst component, an organometallic compound catalyst component containing a metal selected from Groups 1 to 3 of the periodic table, and, if necessary, an electron donor. Slurry polymerization in which propylene polymerization is carried out in an inert solvent, bulk polymerization in which propylene itself is used as a solvent, gas phase polymerization in which propylene gas is mainly used, and polymerization of propylene by a known polymerization method combining these are obtained. Crystalline polypropylene (P
P1) is used in the present invention.

The method for producing the polypropylene composition (PP4) containing the crystalline polypropylene (PP3) having a specific intrinsic viscosity used in the above-mentioned method of the present invention is not particularly limited, and various known methods can be used. . For example, a method of mixing two or more types of crystalline polypropylenes having different molecular weights, and a method of polymerizing crystalline polypropylenes having different molecular weights in multiple stages are possible.

In the method of the present invention, 0.0005 to 0.5 parts by weight of an organic peroxide and 100 parts by weight of the crystalline polypropylene composition (PP4) are selected from diacrylate, dimethacrylate and triacrylate. 0.01 to 5.0 parts by weight of at least one type of crosslinking aid, preferably 0.001 to 0.1 of an organic peroxide and 0.1 to 2.0 parts by weight of the crosslinking aid. 180-300 ^o C
Is a heat treatment method. The amount of the organic peroxide added is 0.
If the amount is less than 0005 parts by weight, the reactivity is inferior and the melt tension is not improved, and if it exceeds 0.5 parts by weight, a decomposition reaction of polypropylene occurs and further improvement of the melt tension is not desired.
If the amount of the crosslinking aid is less than 0.01 parts by weight, the decomposition reaction of polypropylene occurs preferentially, and if it exceeds 5.0 parts by weight, the boiling xylene extraction residual ratio becomes 1% by weight or more, and the moldability deteriorates.

In the present invention, the organic peroxide to be added and mixed is preferably such that the decomposition temperature at which the half-life is 1 minute is in the range of 150 to 270 ^° C.
4-trimethylpentyl-2-hydroperoxide, diisopropylbenzene hydroperoxide,
Hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane, 1,3-bis (t -Butylperoxyisopropyl) -benzene, t-butylcumyl peroxide, di-t-butylperoxide,
2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3, tris (t-butylperoxy)
Dialkyl peroxides such as triazine, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di (t-butyl Peroxy such as peroxy) -butane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester and 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane Ketal, t-butylperoxy-3,5
Alkyl peresters such as 5-trimethylhexanoate, t-butylperoxyacetate, and t-butylperoxybenzoate, and t-butylperoxyisopropyl carbonate as the percarbonate can be given. Of these, dicumyl peroxide,
Di-t-butyl peroxide, 2,5-dimethyl-
2,5-di (t-butylperoxy) -hexyne-3,
Preferred are 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane, 1,3-bis (t-butylperoxyisopropyl) -benzene and the like.

The crosslinking aid used in the present invention is at least one compound selected from diacrylate, dimethacrylate and triacrylate. Specific examples of the crosslinking aid include 1,4-butanediol diacrylate,
6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene such as tripropylene glycol diacrylate, polypropylene glycol diacrylate, etc. Acrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Dimethacrylates such as polyethylene glycol dimethacrylate, trimethylolpropane triacrylate,
Examples thereof include triacrylates such as tetramethylolmethane triacrylate and pentaerythritol triacrylate. Among these crosslinking aids, more preferred are 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, and tripropylene glycol. Triacrylates such as diacrylates such as diacrylate, 1,3-butanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane triacrylate, and tetramethylolmethane triacrylate It is. These crosslinking aids can be used alone or in combination of two or more.

As a method for mixing the crystalline polypropylene composition (PP4) with the organic peroxide and the crosslinking aid, various known methods, for example, a method in which polypropylene is mixed with a powdery or liquid organic peroxide and a crosslinking aid are used. A method of mixing with a shell mixer, a tumbler or the like can be used.

The method for producing polypropylene according to the present invention is characterized in that the mixture is heated to a temperature higher than the melting point of polypropylene using a single-screw extruder, a twin-screw extruder, an extruder combining these with a gear pump, a Brabender, a Banbury mixer and the like. For about 10 seconds to 1 hour, preferably about 20 seconds to 30 minutes. If the temperature of the heat treatment is lower than 180 ^° C., the crosslinking reaction of the polypropylene does not sufficiently occur, and if it exceeds 300 ^° C., the polypropylene decomposition reaction takes precedence, resulting in a polypropylene having poor mechanical strength.

When 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,
Various additives such as inorganic or organic fillers can be blended.

The desired modified polypropylene of the present invention is obtained by the above-mentioned method.
Must have the features described above. Unless these characteristics are satisfied, the object of the present invention cannot be achieved.

The modified polypropylene of the present invention thus obtained has an extremely high melt tension, is excellent in moldability, and can be used again as a molded article and then remelted and recycled. Suitable for molding, foam molding, extrusion molding, but not limited to the molding field, various types of containers such as hollow containers, films, sheets, pipes, fibers, etc., by injection molding, T-die molding, thermoforming, etc. It can be used for molded articles.

[0034]

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) Boiling xylene extraction residual ratio: measured by the method described above. (Unit: weight%) (2) Intrinsic viscosity: [η], measured by the method described above.
(Unit: dl / g) (3) Melt tension: (MS), measured by the method described above. (Unit: cN)

Example 1 Using a catalyst obtained by combining the titanium trichloride composition obtained by the method described in Example 1 in JP-B-59-28573, diethylaluminum chloride, and diethylene glycol dimethyl ether as a third component,
Using three continuous slurry polymerization reactors connected in series, while maintaining different hydrogen concentrations in the gas phase in each polymerization reactor, the intrinsic viscosity of the polymer [η Is 1.24 dl / g, and the intrinsic viscosity of the polymer formed in the second-stage polymerization in the second-stage polymerization vessel is 50% by weight based on the total polymerization amount. [Η] is 1.97 dl / g, and the amount of polymerization in the second stage is 30% by weight based on the total amount of polymerization.
The intrinsic viscosity [η] of the polymer formed in the second stage polymerization is 4.4.
Propylene is continuously multi-stage polymerized in n-hexane so that the intrinsic viscosity [η] is 2.10 dl / g so that the polymerization amount of the third stage is 20% by weight based on the total polymerization amount of 5 dl / g. g
Was obtained and used as a polypropylene composition (PP4). 100 parts by weight of the obtained polypropylene composition (PP4) was mixed with 2,6-di-t-butyl-
0.1 parts by weight of p-cresol, 0.05 parts by weight of tetrakis [methylene (3-5-di-t-butyl-4-hydroxy) hydrocinnamate] methane, 0.1 parts by weight of calcium stearate, 2,5- Dimethyl-2,5-di (t-butylperoxy) -hexane (0.01 part by weight) and 1,6-hexanediol diacrylate (0.7 part by weight) were added and mixed with a Henschel mixer. Resin temperature 2 using a single screw extruder
The mixture was kneaded and granulated at 20 ^° C. Table 1 shows the physical properties of the modified polypropylene (PP2) obtained here.

Example 2 In Example 1, to obtain the polypropylene composition (PP4) used in the reaction, propylene was slurry in two stages using two continuous slurry polymerization reactors connected in series.
The polypropylene obtained by polymerization was used as a polypropylene composition (PP4). 100 parts by weight of the obtained polypropylene composition (PP4) was mixed with 2,6-di-t-butyl-p.
Cresol 0.1 part by weight, tetrakis [methylene (3
-5-di-t-butyl-4-hydroxy) hydrocinnamate] methane 0.05 part by weight, calcium stearate 0.1 part by weight, 2,5-dimethyl-2,5-di (t-
Butyl peroxy) -hexane (0.005 parts by weight) and diethylene glycol diacrylate (0.5 parts by weight) were added and mixed by a Henschel mixer. The mixture was heated at a resin temperature of 220 ^° C. using a single screw extruder having a screw diameter of 40 mm.
Under the following conditions. Table 1 shows the physical properties of the modified polypropylene (PP2) obtained here.

Comparative Example 1 In Example 1, when the propylene homopolymer used as a raw material was obtained, the intrinsic viscosity [η] of the polymer produced in the first step by changing the hydrogen concentration was 2.10 dl / g, The intrinsic viscosity [η] of the polymer formed in the second-stage polymerization is 2.23 dl /
g, and propylene is continuously multi-stage polymerized in n-hexane so that the intrinsic viscosity [η] of the polymer produced in the third stage polymerization becomes 2.40 dl / g. Was 2.21 dl / g. A polypropylene pellet was obtained in the same manner as in Example 1 except that the polypropylene was used as a raw material polypropylene. Table 1 shows the physical properties of the modified polypropylene obtained here.

Comparative Example 2 0.1 part by weight of 2,6-di-t-butyl-p-cresol was added to 100 parts by weight of the raw material polypropylene used in Example 1, and tetrakis [methylene (3-5-di-t-butyl) −
4-Hydroxy) hydrocinnamate] methane 0.05
Parts by weight and 0.1 part by weight of calcium stearate were added and mixed by a Henschel mixer, and the mixture was kneaded and granulated using a single screw extruder having a screw diameter of 40 mm at a resin temperature of 220 ^° C. Table 1 shows the physical properties of the obtained polypropylene.

Comparative Example 3 In Example 1, when obtaining a propylene homopolymer used as a raw material, propylene was polymerized using a single polymerization vessel without multi-stage polymerization, and the amount of hydrogen was changed. Propylene was slurry polymerized in the same manner as in Example 1 except that the intrinsic viscosity [η] was 1.61 dl /
g of propylene homopolymer was obtained. A polypropylene pellet was obtained in the same manner as in Example 2 except that the polypropylene was used as a raw material polypropylene. Table 1 shows the physical properties of the modified polypropylene obtained here.

Comparative Example 4 0.1 part by weight of 2,6-di-t-butyl-p-cresol was added to 100 parts by weight of the raw material polypropylene used in Example 2 and tetrakis [methylene (3-5-di-t-butyl). −
4-Hydroxy) hydrocinnamate] methane 0.05
Parts by weight and 0.1 part by weight of calcium stearate were added and mixed by a Henschel mixer, and the mixture was kneaded and granulated using a single screw extruder having a screw diameter of 40 mm at a resin temperature of 220 ^° C. Table 1 shows the physical properties of the obtained polypropylene.

[0041]

[Table 1]

Example 3 A catalyst combining magnesium chloride-supported titanium catalyst component obtained by the method described in Example 1 in JP-A-62-104812 with triethylaluminum, and diisopropyldimethoxysilane as the third component was used. Therefore, two continuous gas-phase polymerization reactors connected in series are used, and while maintaining different hydrogen concentrations in the gas phase in each polymerization reactor, the polymer inherent in the first-stage polymerization reactor is maintained. The viscosity [η] is 4.70 dl / g, the polymerization amount in the first stage is 25% by weight based on the total polymerization amount, and the weight generated in the second stage polymerization in the second stage polymerization vessel. Propylene is continuously subjected to two-stage gas phase polymerization so that the intrinsic viscosity [η] of the coalesce is 0.49 dl / g and the polymerization amount of the second stage is 75% by weight based on the total polymerization amount, [Η] is 1.54 dl /
g of propylene homopolymer was obtained. A polypropylene pellet was obtained in the same manner as in Example 1 except that the polypropylene was used as a raw material polypropylene. Table 2 shows the physical properties of the modified polypropylene obtained here.

Comparative Example 5 In the same manner as in Example 3 except that one polymerization reactor was used and the amount of hydrogen was adjusted, propylene was vapor-phased in the same manner as in Example 3 except that a polypropylene used as a raw material was obtained. By polymerization, a propylene homopolymer having an intrinsic viscosity [η] of 1.50 dl / g was obtained. Using this polypropylene as a raw material polypropylene, a polypropylene pellet was obtained in the same manner as in Example 3. Table 2 shows the physical properties of the modified polypropylene obtained here.

Example 4 Using the same catalyst as in Example 3, in the first stage, the intrinsic viscosity [η] of the polymer was 4.25 dl / g in the bulk polymerization. Random copolymerization of propylene and ethylene was carried out so that the content of ethylene unit became 30% by weight and the content of ethylene unit became 0.2% by weight. Subsequently, the intrinsic viscosity [η] of the polymer formed in the second-stage polymerization by gas-phase polymerization in the same polymerization vessel is 1.29 dl / g, and the amount of the second-stage polymerization relative to the total amount of polymerization is 70% by weight. Random copolymerization of propylene and ethylene was performed so that the ethylene unit content was 0.2% by weight. The intrinsic viscosity [η] thus obtained is 2.18 dl / g, and the ethylene unit content is 0.1.
2% by weight of a propylene-ethylene random copolymer was used as a polypropylene composition (PP4). 100 parts by weight of the obtained polypropylene was mixed with 2,6-di-t-butyl-p-
Cresol 0.1 part by weight, tetrakis [methylene (3-
5-Di-t-butyl-4-hydroxy) hydrocinnamate] methane 0.05 parts by weight, calcium stearate 0.1 parts by weight, 2,5-dimethyl-2,5-di (t-butylperoxy)- 0.005 parts by weight of hexane and 0.7 parts by weight of 1,6-hexanediol diacrylate were added and mixed by a Henschel mixer, and the mixture was heated to a resin temperature of 220 using a single screw extruder having a screw diameter of 40 mm.
^{o It} was kneaded and granulated under the condition of C. Table 2 shows the physical properties of the modified polypropylene obtained here.

Comparative Example 6 In Example 4, when obtaining polypropylene used as a raw material, except that bulk polymerization was performed in one stage without performing polymerization in multiple stages, and that the amounts of ethylene and hydrogen were adjusted. Was obtained by copolymerizing propylene and ethylene in the same manner as in Example 4. The ethylene unit polymerization amount was 0.2% by weight and the intrinsic viscosity [η] was 2.12.
The procedure was performed in the same manner as in Example 4 except that a dl / g propylene-ethylene random copolymer was used as a raw material. Table 2 shows the physical properties of the modified polypropylene obtained here.

Example 5 Using the same catalyst as in Example 3, using a batch type slurry polymerization reactor, copolymerization of propylene, ethylene and butene-1 in n-hexane was carried out to reduce the ethylene unit content. 3.2, propylene having a butene-1 unit content of 2.5% by weight and an intrinsic viscosity [η] of 3.05 dl / g.
An ethylene-butene-1 random copolymer was obtained. According to the same polymerization method, the ethylene unit content is 3.2, the butene-1 unit content is 2.5% by weight, and the intrinsic viscosity [η] is 1.
61 dl / g, and intrinsic viscosity [η] of 1.53 dl / g
g of propylene-ethylene-butene-1 random copolymer were separately obtained. Of the copolymers thus obtained, 5 copolymers having an intrinsic viscosity [η] of 3.05 dl / g
30% by weight of a copolymer having an intrinsic viscosity [η] of 1.61 dl / g and an intrinsic viscosity [η] of 1.53 dl / g.
A copolymer composition (PP4) was obtained by mixing 65 g by weight of the copolymer (g). The obtained polypropylene 1
0.1 parts by weight of 2,6-di-t-butyl-p-cresol to 00 parts by weight of tetrakis [methylene (3-5-di-t
-Butyl-4-hydroxy) hydrocinnamate] methane 0.05 parts by weight, calcium stearate 0.1 parts by weight, 1,3-bis (t-butylperoxy-isopropyl) -benzene 0.005 parts by weight and trimethylol 0.4 parts by weight of propane triacrylate was added and mixed with a Henschel mixer, and the mixture was adjusted to a screw diameter of 40 m.
The mixture was kneaded and granulated using a single screw extruder at a resin temperature of 210 ^° C. Table 2 shows the physical properties of the modified polypropylene obtained here.

Comparative Example 7 The ethylene unit content obtained by the polymerization in Example 5 was 3.2.
A propylene-ethylene-butene-1 copolymer having a weight% of butene-1 unit content of 2.5% by weight and an intrinsic viscosity [η] of 1.61 dl / g is referred to as a polypropylene composition (PP4). Other than that, it carried out similarly to Example 5.
Table 2 shows the physical properties of the modified polypropylene obtained here.

[0048]

[Table 2]

Example 6 A polypropylene was obtained in the same manner as in Example 1 except that 0.1 part by weight of talc was added as a foam nucleating agent during the heat treatment of the polypropylene composition (PP4). The obtained pellets were fed to a single screw extruder set at 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 in the middle of the extruder. Attached to the extruder,
Using a nozzle-shaped mold with a diameter of 5 mm, mold temperature 155 ^°
Extrusion foam molding was performed at C. The surface of the obtained foam was smooth, and no abnormal air bubbles were observed, and the foam had uniform air bubbles.

Comparative Example 8 A polypropylene was obtained in the same manner as in Comparative Example 1, except that 0.1 part by weight of talc was added as a foam nucleating agent during the heat treatment of the raw polypropylene. Extrusion foaming was carried out in the same manner as in Example 6 except that this polypropylene was used. As a result, the foam obtained had outgassing and was poor in appearance.

Example 7 For a propylene-ethylene random copolymer pellet (PP2) obtained in the same manner as in Example 4, using an extruder with a T-die and a screw diameter of 65 mm at 260 ^° C. Extrusion sheeting was performed to obtain a sheet having a thickness of 0.5 mm. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was fixed in a 40 cm square frame, placed in a constant temperature room at 210 ^° C., and behavior was observed. The center of the sheet began to hang down due to the heating, and when the sheet hanged down by 40 mm, the hang was stopped and, conversely, the hang down was raised.
When 14 seconds had elapsed after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. The amount of sag was small, and the time until the start of re-sagging was as long as 14 seconds, indicating that the sheet was extremely excellent in heat vacuum formability.

Comparative Example 9 In Example 7, instead of the polypropylene of the present invention,
A sheet was obtained in the same manner except that pellets of the propylene-ethylene random copolymer obtained in the same manner as in Comparative Example 6 were used. When the heating behavior of the sheet was observed in the same manner as in Example 7, it was found that the droop stopped at 46 mm, and the time until the start of the re-droop was as short as 6 seconds. The moldability was poor.

Example 8 In order to recycle the molded article of the present invention, modified polypropylene pellets obtained in the same manner as in Example 1 were subjected to JIS at an injection molding machine at a molten resin temperature of 230 ^° C. and a mold temperature of 50 ^° C.
A large number of test pieces for measuring the bending elastic modulus of the shape were prepared, and the injection-molded test pieces were crushed by a crusher to obtain a crushed test piece of 10 pieces.
A polypropylene composition consisting of 90% by weight of the modified polypropylene pellets obtained in the same manner as in Example 1 was molded using a direct blow molding machine having a screw diameter of 65 mm at a molding temperature of 230 ^° C. and a mold temperature of 20%. ^When a kerosene tank having an inner volume of 20 l was hollow-formed at 0 ^° C., a uniform hollow-formed product having no unevenness in thickness was obtained without drawdown of the parison.

Comparative Example 10 A 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 2 were used as the polypropylene. This resulted in a non-uniform hollow molded product with uneven thickness.

[0055]

As is clear from the above description, according to the method of the present invention, the melt tension of polypropylene is remarkably improved, and no gel component is contained.
It has excellent moldability such as extrusion molding, and can be used in a wide range of applications limited to conventional polypropylene.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-93709 (JP, A) JP-A-59-93711 (JP, A) JP-A-61-16944 (JP, A) JP-A-61-944 152754 (JP, A) JP-A-6-16743 (JP, A) JP-A-4-25520 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 255/02-255 / 06

Claims (4)

(57) [Claims] 1. A crystalline polypropylene (PP1) 100
0.0005 to 0.5 parts by weight of an organic peroxide and at least one type of crosslinking aid selected from diacrylate, dimethacrylate and
In a method for producing a modified polypropylene (PP2) having a boiling xylene extraction residual ratio of 1% by weight or less by blending 1 to 5.0 parts by weight and heat-treating at 180 to 300 ° C, the crystalline polypropylene (PP1) The intrinsic viscosity [η] measured at 135 ° C. in tetralin was 2.
5 to 10 dl / g of crystalline polypropylene (PP
(3) a modified polypropylene comprising a crystalline polypropylene composition (PP4) containing 1 to 50% by weight and having an intrinsic viscosity [η] of 1.0 to 4.0 dl / g as a whole. Manufacturing method. 2. The modified polypropylene has an intrinsic viscosity [η] of 2.5 dl / in tetralin measured at 135 ° C.
The method of claim 1, wherein the weight is less than or equal to g. 3. An overall intrinsic viscosity [η] of crystalline polypropylene (PP3) having an intrinsic viscosity [η] of 2.5 to 10 dl / g in tetralin measured at 135 ° C. Is selected from the group consisting of 0.0005 to 0.5 parts by weight of an organic peroxide and diacrylate, dimethacrylate, and triacrylate with respect to the crystalline polypropylene composition (PP4) having a pH of 1.0 to 4.0 dl / g. A modified polypropylene (PP2) having a boiling xylene extraction residual ratio of 1% by weight or less obtained by blending one or more crosslinking aids in an amount of 0.01 to 5.0 parts by weight and heat-treating at 180 to 300 ° C. Molded products. 4. The modified polypropylene has an intrinsic viscosity [η] of 2.5 dl / in tetralin measured at 135 ° C.
The molded article according to claim 3, which is not more than g.