JP2002210735A - Method for manufacturing low crystalline polyolefin resin granulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a low crystalline polyolefin resin granulating material having no blocking at times of manufacturing, storing and using the material. SOLUTION: The method for manufacturing the low crystalline polyolefin resin granulating material by an underwater cutting granulating method comprises the steps of cutting the molten low crystalline polyolefin resin under water, and then setting a time in which the cut resin piece arrives at a solid liquid separator to 3 s or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a low-crystalline polyolefin resin granule by improving the surface tackiness thereof.
The present invention relates to a method for producing a low-crystalline polyolefin resin granule that does not cause blocking during the production, storage and use of a granule, and a low-crystalline polyolefin resin granule obtained by this production method. .

[0002]

2. Description of the Related Art Amorphous polyolefin resin has flexibility,
Due to its advantages such as low specific gravity and high environmental safety, it is used in a wide range of fields such as hot melt adhesives, floor materials, and flexible film raw materials. However, the amorphous polyolefin resin contains a large amount of a relatively low molecular weight amorphous component, so that the pellet-like or crumb-like raw material has a strong surface tackiness, and therefore the raw material itself is easily blocked, and the raw material itself is easily blocked. There was a problem that it was difficult to take out. In order to improve such problems, attempts have been made to add various additives to the amorphous polyolefin resin to prevent tackiness (JP-A-59-33339, JP-A-59-43044). No.). However, even with these methods, the effect of preventing adhesion is not sufficient,
In some cases, the added additive migrated to the surface of the molded article and caused a problem. In recent years, as a method for solving these problems, a method of dispersing a release agent in water when granulating by an underwater cutting method (Japanese Patent Laid-Open No. 7-40339).
Or a method of staying in warm water for a long time (JP-A-7-316)
222 has been proposed. However, these methods also have a problem that a release agent remains, a problem in production complexity, a decrease in productivity, and the like, and cannot be said to be a sufficient production method. Further, as a new resin replacing the amorphous polyolefin resin, a low-crystalline polyolefin resin produced in a homogeneous catalyst system has been proposed (JP-A-2000-95820). This low-crystalline polyolefin resin has a small amount of low molecular weight components, which are so-called sticky components, and is granulated by a strand cut type granulator, but is not sufficiently flexible.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to improve the surface tackiness of a low-crystalline polyolefin resin granule so that the granule can be produced, stored and stored. A method for producing a low-crystalline polyolefin resin granule that does not cause blocking during use,
It is another object of the present invention to provide a low-crystalline polyolefin resin granule obtained by this production method.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, when producing a low-crystalline polyolefin resin granule by an underwater cutting method, a molten low-crystalline polyolefin resin was produced. After the water-soluble polyolefin resin is cut in water, the time required for the cut resin piece to reach the solid-liquid separator is equal to or longer than a certain time, that is, the residence time of the resin piece in water is set to a certain time. Through the above, it has been found that the object can be achieved, and the present invention has been completed. That is, the present invention relates to [1]
In the method for producing a low-crystalline polyolefin resin granule by underwater cut granulation, after the molten low-crystalline polyolefin resin is cut in water, until the cut resin piece reaches a solid-liquid separator. And a method for producing a low-crystalline polyolefin resin granule, wherein the time is 3 seconds or more. Further, the present invention provides [2] a melting point (T) produced by the method described in [1] above and measured by the following (1) and (2) (1) differential scanning calorimeter (DSC).
m) is from 40 to 100 ° C. (2) The heat of fusion (ΔH) measured by a differential scanning calorimeter (DSC) is from 10 to 30 J / g. It is produced by the method described in the above [1], and the following (3) and (4) (3) mesopentad fraction (mmmm) is 0.2 to 0.6 (4) racemic pentad fraction ( rrrr) and (1-mm
mm) is [rrrr / (1−mmmm)] ≦ 0.1.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the underwater cut granulation method according to the present invention, a resin is extruded in water in a molten state, cut into a spherical or cylindrical shape in water by a rotary cutter or the like to obtain a resin piece, which is cooled. After that, it is separated from water using a solid-liquid separator and dried to obtain granules. In the present invention, the temperature of the molten resin is not particularly limited as long as the resin is in a molten state and can be extruded or cut. When a low crystalline polypropylene resin is used as the resin, the temperature is usually 60 to 300 ° C, preferably 100 to 300 ° C.
It is 280 ° C, more preferably 120-260 ° C. The rotary cutter used for cutting the molten resin may be any ordinary underwater cutter for resin, and is not particularly limited. In the present invention, the temperature of the water from which the molten resin is extruded is usually 0 to 40 ° C, preferably 10 to 30 ° C. If the water temperature is lower than 0 ° C., the water freezes, and there is no necessity of heating the water temperature to 40 ° C. or higher by a heater or the like. When the water temperature is 60 ° C. or higher, the resin pieces are fused to each other and do not form granules. In the present invention, the time required for the resin piece to reach the solid-liquid separator needs to be 3 seconds or more, and there is no particular upper limit, but from the viewpoint of production efficiency, 3 to 600 seconds is preferable, and more preferably. Is 3 to 60
Seconds, particularly preferably 3 to 30 seconds. If this time is less than 3 seconds, blocking of the granules is likely to occur, and the flow characteristics will decrease. Also, this time is 60
Even if the time exceeds 0 second, there is no difference in effect, and there is a possibility that inconveniences such as a complicated production line and a special facility are required. The time until the resin piece reaches the solid-liquid separator can be set, for example, by adjusting the length of a connecting pipe connecting the underwater cutter and the solid-liquid separating device. In the present invention, the solid-liquid separator used to separate and dry the resin pieces from water is not particularly limited as long as it is a usual solid-liquid separation dryer for resin.

The low-crystalline polyolefin resin granule of the present invention is a low-crystalline polyolefin resin granule produced by the above method and satisfying the following (1) and (2). (1) Melting point (T) measured by differential scanning calorimeter (DSC)
m) is from 40 to 100 ° C. (2) The heat of fusion (ΔH) measured by a differential scanning calorimeter (DSC) is from 10 to 30 J / g.
If m) is less than 40 ° C., there is a disadvantage that the granules are easily fused to each other, and if the melting point (Tm) exceeds 100 ° C., there is a disadvantage that flexibility and transparency tend to be insufficient. . The melting point (Tm) is preferably from 60 to 90C.
Further, when the heat of fusion (ΔH) is less than 10 J / g, there is a disadvantage that stickiness is likely to be caused, and when the heat of fusion (ΔH) exceeds 30 J / g, there is a disadvantage that flexibility is insufficient. . The heat of fusion (ΔH) is 15-
30 J / g is preferred. In addition, a differential scanning calorimeter (DS
The measurement according to C) will be described in Examples.

[0007] The low-crystalline polyolefin resin granules of the present invention are produced by the above-mentioned method, and the following (3)
And (4) a granulated low-crystalline polyolefin resin. (3) The mesopentad fraction (mmmm) is 0.2 to 0.6. (4) The racemic pentad fraction (rrrr) and (1-mm)
mm) is [rrrr / (1-mmmm)] ≦ 0.1 In the low-crystalline polyolefin resin granules, the mesopentad fraction (mmmm) is preferably 0.3 to 0.6, and 0.4.
~ 0.5 is more preferred. Racemic pentad fraction (rr
rr) and (1-mmmm) are represented by [rrrr /
(1-mmmm)] ≦ 0.08,
More preferably, [rrrr / (1-mmmm)] ≦ 0.06, and [rrrr / (1-mmmm)] ≦ 0.
Particularly preferred is 05. When the low-crystalline polyolefin resin granule satisfies the above relationship, the obtained product has an excellent balance between the amount of the sticky component and the low elastic modulus. In other words, elasticity is low and flexibility (also called softness)
It has the advantage of having less sticky components and excellent surface characteristics (e.g., less transfer of sticky components to bleed and other products). Mesopentad fraction of low-crystalline polyolefin resin granules (mmm
If m) is less than 0.2, stickiness is caused, and if it exceeds 0.6, the elastic modulus is undesirably high. [Rrrr / (1-mmmm)] of low-crystalline polyolefin resin granules
If it exceeds 0.1, it may cause stickiness. Note that the mesopentad fraction (mmmm fraction) used in the present invention is described in Macromolecules, 6, 925 (197) by A. Zambelli and others.
3) is a meso fraction in pentad units in a polypropylene molecular chain measured by a signal of a methyl group in a ¹³ C-NMR spectrum in accordance with the method proposed in “3)”. When this is increased, it means that stereoregularity is increased. Similarly, the racemic pentad fraction (rrrr fraction) is a racemic fraction in pentad units in a polypropylene molecular chain. [Rrrr / (1-mmmm)] is an index obtained from the above fraction of the pentad unit and is an index indicating the uniformity of the stereoregularity distribution of the propylene polymer. When this value is increased, the stereoregularity distribution is expanded, and high stereoregularity PP (polypropylene) and atactic PP as in the case of conventional polypropylene produced using an existing catalyst system.
(APP), which means that tackiness increases and transparency decreases. The measurement of the ¹³ C-NMR spectrum was performed by A. Zambelli.
"Macromolecules, 8,687
(1975) "according to the assignment of peaks proposed by the following apparatus and conditions.

Apparatus: JNM-EX40 manufactured by JEOL Ltd.
Type 0 ¹³ C-NMR apparatus Method: Proton complete decoupling method Concentration: 220 mg / ml Solvent: 90:10 (volume ratio) mixed solvent of 1,2,4-trichlorobenzene and heavy benzene Temperature: 130 ° C. Pulse width: 45 ° Pulse repetition time: 4 seconds Integration: 10000 times As the low crystalline polyolefin resin granules, in addition to the above (3) and (4) requirements,

(5) A low-order polyolefin resin granule having an intrinsic viscosity [η] of 0.1 to 3.0 deciliter / g measured in tetralin at 135 ° C. is preferred. Among them, more preferably 0.2 to 2.8 deciliter / g, and particularly preferably 0.3 to 2.5 deciliter / g. If the intrinsic viscosity [η] is less than 0.1 deciliter / g, the strength may decrease. On the other hand, if it exceeds 3.0 deciliters / g, the flowability may be reduced and the moldability may be poor.

The granulated low-crystalline polyolefin resin of the present invention preferably further satisfies any of the following requirements. The molecular weight distribution (Mw / Mn) measured by the gel permeation (GPC) method is 4 or less, more preferably 3.
It is 5 or less, particularly preferably 3 or less. Molecular weight distribution (M
If (w / Mn) exceeds 4, stickiness may occur. Note that the above Mw / Mn is determined by a gel permeation chromatography (GPC) method described in Examples. The tensile modulus is preferably 100 MPa or less, more preferably 80 MPa or less.

The low-crystalline polyolefin resin granules of the present invention satisfy the above (1) and (2), (3) and (4), or (1) to (4). In the present invention, the low-crystalline polyolefin resin is preferably a low-crystalline polypropylene resin, and a copolymer of 2% by mass or less of a comonomer other than propylene may be used as long as the object of the present invention is not impaired. Examples of the comonomer include ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like, and in the present invention, one or more of these can be used. The method for producing the low-crystalline polypropylene resin used in the present invention includes a metallocene catalyst obtained by combining (A) a transition metal compound forming a crosslinked structure via two crosslinking groups and (B) a cocatalyst. The method of polymerizing or copolymerizing propylene using is preferred. Specifically, the general formula (I)

[0012]

Embedded image

[Wherein M is a group 3 to 10 of the periodic table or La
E represents a tanthanoid metal element ¹And E^TwoIs it
Substituted cyclopentadienyl group, indenyl group, substituted
Indenyl group, heterocyclopentadienyl group,
Telocyclopentadienyl group, amide group, phosphide
Ligand selected from the group consisting of a group, a hydrocarbon group and a silicon-containing group
And A¹And A^TwoTo form a crosslinked structure via
And they may be the same or different
X represents a σ-binding ligand, and when there are a plurality of Xs,
A plurality of X may be the same or different, and other X,
E¹, E^TwoAlternatively, it may be crosslinked with Y. Y is Lewis salt
A plurality of Ys are the same or different
Other Y, E¹, E^TwoOr cross-linked with X
May be, A¹And A^TwoIs the two that binds the two ligands
A divalent crosslinking group, a hydrocarbon group having 1 to 20 carbon atoms,
A halogen-containing hydrocarbon group having a prime number of 1 to 20, a silicon-containing group,
Germanium-containing groups, tin-containing groups, -O-, -CO-,
-S-, -SO_Two-, -Se-, -NR¹-, -PR¹
-, -P (O) R¹-, -BR¹-Or-AlR¹-
And R¹Is a hydrogen atom, a halogen atom, a carbon number of 1 to 20
A hydrocarbon group or a halogen-containing hydrocarbon having 1 to 20 carbon atoms
Denote radicals, which may be the same or different
Good. q is an integer of 1 to 5 and represents ((valence of M) -2).
And r represents an integer of 0 to 3. Transition metallization represented by
Compound (A), and the transition metal compound or the component (A).
Capable of forming an ionic complex by reacting with derivatives of
Selected from (B-1) and aluminoxane (B-2)
In the presence of a polymerization catalyst containing the co-catalyst component (B),
A method of polymerizing or copolymerizing pyrene is exemplified.

A specific example of the transition metal compound represented by the general formula (I) is (1,2′-dimethylsilylene)
(2,1′-dimethylsilylene) bis (3-n-butylindenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium Dichloride, (1,2′-dimethylsilylene) (2,
1′-dimethylsilylene) bis (3-phenylindenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (4,5
-Benzoindenyl) zirconium dichloride, (1,
2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (4-isopropylindenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2
1′-dimethylsilylene) bis (5,6-dimethylindenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (4,7-di-i-propylindenyl) ) Zirconium dichloride, (1,2′-dimethylsilylene) (2,
1'-dimethylsilylene) bis (4-phenylindenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3-methyl-4-i-propylindenyl) zirconium Dichloride, (1,2'-dimethylsilylene) (2,1'-
Dimethylsilylene) bis (5,6-benzoindenyl)
Zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-isopropylidene) -bis (indenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-isopropylidene) -bis ( 3-
Methylindenyl) zirconium dichloride, (1,
2′-dimethylsilylene) (2,1′-isopropylidene) -bis (3-i-propylindenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2
1'-isopropylidene) -bis (3-n-butylindenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-isopropylidene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride , Etc. and those obtained by substituting zirconium in these compounds with titanium or hafnium.

Next, the component (B-1) of the component (B) includes triethylammonium tetraphenylborate, tri-n-butylammonium tetraphenylborate, trimethylammonium tetraphenylborate, tetraethylammonium tetraphenylborate, Examples thereof include methyl tetraphenylborate (tri-n-butyl) ammonium and benzyltetraphenylborate (tri-n-butyl) ammonium. (B-1) may be used alone, or two or more kinds may be used in combination. On the other hand, as the aluminoxane of the component (B-2),
Methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane and the like are mentioned. These aluminoxanes may be used alone or in a combination of two or more. As the polymerization catalyst, an organoaluminum compound can be used as the component (C) in addition to the components (A) and (B).

As the organoaluminum compound (C), trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, diisobutyl Aluminum hydride,
Examples thereof include diethyl aluminum hydride and ethyl aluminum sesquichloride. These organoaluminum compounds may be used alone or in combination of two or more. Here, in the polymerization of propylene, at least one of the catalyst components can be used by being supported on a suitable carrier.

The polymerization method is not particularly limited, and any method such as a slurry polymerization method, a gas phase polymerization method, a bulk polymerization method, a solution polymerization method, and a suspension polymerization method may be used. Legitization is particularly preferred. The polymerization temperature is usually -100 to 2
At 50 ° C., the usage ratio of the catalyst to the reaction raw material is preferably such that the raw material monomer / component (A) (molar ratio) is 1 to 10
^8, it is preferable that the particular 100 to 10 ^5. Further, the polymerization time is usually 5 minutes to 10 hours, and the reaction pressure is usually
Normal pressure to 20 MPa (gauge).

In the present invention, if necessary, various additives such as a plasticizer, an inorganic filler, an antioxidant, a nucleating agent and the like can be added to the low-crystalline polyolefin resin. These may be used alone or in combination of two or more. Examples of the plasticizer include polyethylene glycol, polyamide oligomer, ethylene bisstearamide, phthalic acid ester, polystyrene oligomer, polyethylene wax, and silicone oil. As the inorganic filler, calcium carbonate,
Examples include spherical fillers such as kaolin (aluminum silicate) and silica, plate-like fillers such as talc and mica, and fibrous fillers such as glass fibers. As the antioxidant, a known one such as a phenolic antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant can be used.
Examples of phenolic antioxidants include Ciba Specialty Chemicals Co., Ltd. Irganox 1010: Substance name: pentaerythrityl-tetrakis [3- (3,5-di-t)
-Butyl-4-hydroxyphenyl) propionate]
Examples of the phosphorus-based antioxidant include Ciba Specialty Chemicals Co., Ltd. Irgafos 168: substance name: tris (2,4-di-t-butylphenyl) phosphite, and examples of the sulfur-based antioxidant include Sumilizer. TPL (Sumitomo Chemical Co., Ltd.) and the like. Examples of the nucleating agent include a high melting point polymer, an organic carboxylic acid or its metal salt, an organic phosphoric acid compound or its metal salt, dibenzylidene sorbitols, rosin acid partial metal salts, inorganic fine particles, imides, amides, quinacridones, Examples include quinones and mixtures thereof.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 (1) Preparation of catalyst and production of low crystalline propylene Synthesis of complex (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride Synthesis (1,2'-dimethylsilylene) (2,
3.0 g (6.97 mmol) of lithium salt of 1'-dimethylsilylene) -bis (indene) was dissolved in 50 ml of THF and cooled to -78 ° C. 2.1 ml (14.2 mmol) of iodomethyltrimethylsilane was slowly added dropwise, and the mixture was stirred at room temperature for 12 hours. The solvent was distilled off, 50 ml of ether was added, and the mixture was washed with a saturated ammonium chloride solution. After liquid separation, the organic phase was dried, and the solvent was removed. 3.04 g (5.88 mmol) of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindene) was removed. I got (Yield 8
Next, 3.04 g of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindene) obtained above was placed in a Schlenk bottle under a nitrogen stream. 5.88 mmol) and 50 ml of ether. Cool to -78 ° C and n-BuLi
(Hexane solution 1.54M) in 7.6 ml (11.7
(mmol), and the mixture was stirred at room temperature for 12 hours. The solvent was distilled off, and the obtained solid was washed with 40 ml of hexane to convert the lithium salt into an ether adduct.
06 g (5.07 mmol) was obtained (yield 73%). ¹ H
_{-NMR (90MHz, THF-d 8} ) results of measurement by the,: δ 0.04 (s, 18H , trimethylsilyl), 0.48 (s, 12H, dimethylsilylene), 1.1
0 (t, 6H, methyl), 2.59 (s, 4H, methylene), 3.38 (q, 4H, methylene), 6.2-7.7
(M, 8H, Ar-H). The lithium salt obtained above was dissolved in 50 ml of toluene under a nitrogen stream. After cooling to −78 ° C., a toluene (20 ml) suspension of zirconium tetrachloride (1.2 g, 5.1 mmol) previously cooled to −78 ° C. was added dropwise. After the addition, the mixture was stirred at room temperature for 6 hours. The solvent of the reaction solution was distilled off.
The obtained residue was recrystallized from dichloromethane to give 0.9 g of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride (1. 3
3 mmol) was obtained (yield 26%). ¹ H-NMR (9
0 MHz, CDCl ₃ ) gives: δ
0.0 (s, 18H, trimethylsilyl), 1.02, 1.1
2 (s, 12H, dimethylsilylene), 2.51 (dd,
4H, methylene), 7.1-7.6 (m, 8H, Ar-H)
Met.

Polymerization of Low Crystalline Propylene 37.4 L / h of n-heptane and 19 mmol of triisobutylaluminum (manufactured by Nippon Alkyl Aluminum Co., Ltd.) were placed in a 250 L stainless steel reactor equipped with a stirrer.
/ H, methylaluminoxane (Albemarle) 13.
6 mmol / h, and 13.6 μmol / h of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride obtained above were continuously supplied.
Further, the volume ratio of hydrogen / propylene in the gas phase was set to 0.02,
Propylene and hydrogen were continuously supplied so as to keep the total pressure in the reactor at 0.8 MPaG. Polymerization was continuously performed at a temperature of 60 ° C. and a residence time of 90 minutes. Post-treatment The following addition was prescribed to the obtained polymerization solution, and a flash drum having a built-in plate fin-type polymer heater was set to 2
Using a step, melt flushing was performed at a jacket temperature of 220 ° C. to remove the solvent.

(Formulation of additives) Phenolic antioxidant: Ciba Specialty Chemicals, Irganox 1010; 500 ppm Phosphorus antioxidant: Ciba Specialty Chemicals, Irgafos 168; 1,000 ppm

(2) Manufacture of granules The molten resin after flushing (resin temperature: 200 ° C.) is extruded by a gear pump, and an underwater cutter (PASC-21-HS type, Tanabe Plastics Machine) equipped with a rotary drum type solid-liquid separator is used. (Manufactured by Sharp Corporation). The time required for the cut resin pieces to reach the solid-liquid separator (residence time of the granules in water) was set by adjusting the length of a connecting pipe connecting the underwater cutter and the solid-liquid separating device. . The residence time of the granules in water at this time is 4 seconds, and the water temperature is 20
° C.

(3) Evaluation of Resin Properties of Granules of Low Crystalline Polypropylene The resin properties of the granules were evaluated by the following method. Moreover, the state of the granulated body was visually observed. Table 1 shows the results. Measurement of [η] It was measured at 135 ° C. in a tetralin solvent using a VMR-053 type automatic viscometer manufactured by Rigosha Co., Ltd. Measurement of Pentad Fraction It was measured by the method described in the text of the specification. Measurement of melt flow rate (MFR) 230 ° C, load 21.1 according to JIS K7210
Measured at 8N. Measurement of molecular weight distribution (Mw / Mn) Mw / Mn was measured by an apparatus described below.

GPC measuring apparatus Column: TOSO GMHHR-H (S) HT Detector: RI detector for liquid chromatogram WATERS 150C Measurement conditions Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145 ° C. Flow rate: 1.0 Milliliter / min Sample concentration: 2.2 mg / ml Injection volume: 160 microliter Calibration curve: Universal Calibration Analysis program: HT-GPC (Ver. 1.0)

DSC measurement Differential scanning calorimeter (manufactured by Perkin-Elmer, DSC-
7) Using a 10 mg sample at 230 ° C. in a nitrogen atmosphere for 3
After melting for one minute, the peak top of the maximum peak of the crystallization exothermic curve obtained by lowering the temperature to -40 ° C at 1 ° C / minute was defined as the crystallization temperature (Tc). Furthermore, -40 ° C
, And the temperature was raised at a rate of 10 ° C./min., And the peak top of the maximum peak of the melting endothermic curve was defined as the melting point (Tm). The endothermic amount obtained at this time was defined as the melting endothermic amount (ΔH). Tensile modulus The granulated material is press-molded to produce a test piece, which is JIS K7
It was measured under the following conditions by a tensile test in accordance with No.113. Crosshead speed: 50 mm / min Test piece shape: No. 2 test piece, thickness 1 mm (4) Evaluation of fluidity of granulated material Single screw extruder (TLC 35-20, manufactured by Tsukada Juki Seisakusho)
The extrudability of the granules from the hopper when extruding the granules from the mold was evaluated according to the following criteria. Table 1 shows the results. ：: The granules could be continuously supplied. X: Granules could not be continuously supplied.

Example 2 In the polymerization of propylene, the hydrogen / propylene ratio was adjusted to 0.0
A granulated body was produced in the same manner as in Example 1, except that the residence time of the resin piece in water during granulation was 8 seconds, and the same evaluation was performed. Table 1 shows the results. Example 3 In the polymerization of propylene, the hydrogen / propylene ratio was adjusted to 0.0
A granulated body was manufactured in the same manner as in Example 1 except that the residence time of the resin piece in water during granulation was 12 seconds, and the same evaluation was performed. Table 1 shows the results. Comparative Example 1 In the polymerization of propylene, the hydrogen / propylene ratio was adjusted to 0.0.
A granulated body was manufactured in the same manner as in Example 1 except that the residence time of the resin piece in water during granulation was set to 2 seconds, and the same evaluation was performed. Table 1 shows the results. Comparative Example 2 The low crystallinity polypropylene obtained in Example 1 was extruded at a resin temperature of 210 ° C. using a single screw extruder (TLC35-20, manufactured by Tsukada Juki Seisakusho) and granulated using a strand cutter. The same evaluation as in Example 1 was performed. Table 1 shows the results.

[0027]

[Table 1]

[0028]

According to the present invention, it is possible to obtain a low-crystalline polyolefin resin granule having improved adhesion on the surface of the granule. The granules are easy to handle without blocking during the production, storage and use of the granules.

Claims (5)

[Claims] 1. A method for producing a low-crystalline polyolefin resin granule by an underwater cut granulation method, wherein a molten low-crystalline polyolefin resin is cut in water, and then the cut resin piece is subjected to solid-liquid separation. A method for producing a low-crystalline polyolefin resin granule, wherein the time required to reach the machine is 3 seconds or more. 2. A differential scanning calorimeter (DSC) produced by the method according to claim 1 and comprising the following (1) and (2) (1):
(2) The heat of fusion (ΔH) measured with a differential scanning calorimeter (DSC) is 10 to 30 J / g. body. 3. The mesopentad fraction (mmm) produced by the method according to claim 1 and having the following (3) and (4) (3):
m) is 0.2 to 0.6. (4) The racemic pentad fraction (rrrr) and (1-mm)
mm) and [rrrr / (1-mmmm)] ≦ 0.1. 4. The method according to claim 1, wherein the low-crystalline polyolefin resin is a low-crystalline polypropylene resin. 5. The granulated low-crystalline polyolefin resin according to claim 2, wherein the low-crystalline polyolefin resin is a low-crystalline polypropylene resin.