JP2000037764A - Extrusion machine and method using the machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the crosslinking reaction uniform and enhance the physical properties and the productivity by specifying the screw array, screw length and outer diametral ratio of the screw of each of a first kneading zone for crosslinking and a second kneading zone for crosslinking and providing a specified number of oil addition injection apertures for rubber on the barrel of an extrusion machine from the extreme upstream of the first kneading zone to the second kneading zone. SOLUTION: In a biaxial extrusion machine with 40-136 mm barrel dia. which has two or more kneading zones, the screw array of a first kneading zone for crosslinking is constituted of a proper combination of a plurality of kneading discs with varying angle of torsion and width of each blade, a mixing screw, a reverse flighted screw, a varistor ring and the like. Further the L/D (L = the length of the screw and D = the outer dia. of the screw) of the first kneading zone for crosslinking is 2.0-15 and the L/D of a second kneading zone is 10-30. In addition, a single oil addition injection aperture for rubber or more are provided on the barrel of an extrusion machine across the distance equivalent to 1/2 of the length between the extreme upstream of the first kneading zone and the second kneading zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a crosslinking reaction of a rubber-based oil by adding a crosslinking agent to a crosslinkable elastomer selected from an olefin elastomer and a vinyl aromatic block copolymer and a propylene polymer to cause crosslinking. The present invention relates to an extruder and a method for producing a thermoplastic elastomer which is a composition to be added to a zone.

[0002]

2. Description of the Related Art Thermoplastic elastomer composition by so-called dynamic crosslinking in which a radically crosslinkable elastomer and an olefin resin having no radically crosslinkable properties such as PP are crosslinked while being melt-kneaded in an extruder in the presence of a radical initiator. Objects are already known technologies and are widely used for applications such as automobile parts.

It is known to use an extruder as an apparatus for producing this thermoplastic elastomer. 2-52
No. 648 discloses a method in which an olefin-based elastomer, polypropylene, and a crosslinking agent are supplied collectively by using a twin-screw extruder. In Japanese Patent Publication No. 05-87529,
A method of kneading at a shear rate of at least 2,000 seconds to ¹ in the method of dynamically crosslinking plastic and rubber is disclosed. JP-A-6-299018 discloses a method in which a radical initiator crosslinked olefin and a radical initiator decomposed olefin are subjected to dynamic heat treatment in the presence of a radical initiator, and a mineral oil-based softening agent is added. JP-A-9-955
40, in a production method of dynamically thermoplastically crosslinking an olefin-based copolymer rubber and an olefin-based plastics to form a thermoplastic composition, the twin-screw extruder has one or more kneading units in a dynamically crosslinked unit. Discloses a manufacturing method comprising a screw having a progressive kneading disk whose first blade width is less than 13 mm.

[0004]

The twin-screw co-rotating extruder of the apparatus for producing a thermoplastic elastomer is composed of ten or more kinds of screw parts having screw part lengths Ls / D = 0.5 to 1.5. There are a huge variety of combinations to design. According to our knowledge, for example, even if the length of the kneading zone is the same, productivity and physical properties change drastically depending on how the screw configuration is assembled. In addition, when the type and shape of the resin change, the physical properties and productivity often change even with the same screw configuration. However, there is almost no technical disclosure about a screw configuration for making the crosslinking reaction and oil dispersion uniform.

According to our findings, in a dynamic crosslinking reaction using an extruder, the temperature of the molten resin in the kneading zone for crosslinking in the extruder is in the range of 170 to 290 ° C. Since the life of the radical initiator used under these reaction temperature conditions is as short as 10 seconds or more, the crosslinking reaction becomes uneven unless the radical initiator is uniformly dispersed in the resin immediately after the start of kneading. It has been found that a technique of rapidly dispersing the radical initiator in the constitution and a technique of lowering the resin temperature in the crosslinking reaction zone to lengthen the reaction time are the most important.

That is, in order to quickly plasticize solid pellets, the pellets are ground by the shearing force of the blades of the progressive kneading disk, and oil is added to the crosslinking reaction zone in order to prevent the resin temperature from rising during the crosslinking reaction. I found out what to do. However, there has been no disclosure of these most important technologies.

The prior art of Japanese Patent Publication No. 2-52648 does not disclose any screw configuration. This prior art is a technique in which EPDM is impregnated with a rubber oil in advance and crosslinked. According to the findings obtained by our invention, rubber oil may be impregnated with an elastomer having an unsaturated bond such as EPDM, but the oil may be impregnated with an olefin elastomer having no unsaturated bond. Since the cross-linking reaction is less likely to occur when immersed, the properties are better when oil is added during the cross-linking reaction.

[0008] Japanese Patent Publication No. 05-87529 discloses that the maximum shear rate when passing between a screw tip and a barrel in a method for dynamically crosslinking plastic and rubber is from 2000 seconds to ¹ hour.
Although kneading is described above, our findings show that the maximum shear rate decreases, especially when the distance between the screw tip and barrel of the kneading disc in the plasticizing zone of solid resin is reduced, but the amount of resin that passes through increases. Therefore, the radical initiator can be dispersed and mixed in a short time.

According to Japanese Patent Application Laid-Open No. Hei 6-299018, the oil is added after the crosslinking reaction is completed in this prior art,
According to our findings, the addition of the oil to the cross-linking reaction zone can reduce the rate of increase in the resin temperature and prevent the deterioration of the physical properties.

Japanese Patent Application Laid-Open No. 9-95540 states that a first-feed kneading disk having a first blade width of less than 13 mm is formed.
While this method is suitable for rapid dispersion and mixing in the molten resin, our findings are not suitable for rapidly dispersing the radical initiator in the resin during the plasticization process in which the resin melts from a solid. Rather, it has been found that it is important to quickly plasticize and disperse and mix the radical initiator using a kneading disk that generates a strong shear force when the solid resin plasticizes.

In the screw configuration design of the kneading zone of the twin screw extruder for the thermoplastic elastomer used in the present invention,
The screw configuration for performing the crosslinking reaction, the position where the oil is added, and the design of the screw configuration are important for obtaining good physical properties, extrusion operation stability, and productivity, and the extrusion method is also important.

The present invention provides an extruder having a screw structure capable of uniformly performing a cross-linking reaction between a thermoplastic elastomer and a thermoplastic resin with the addition of oil and realizing excellent extrusion stability and productivity. It is an object of the present invention to provide a method for producing an elastomer composition in which oil is uniformly dispersed using the same.

[0013]

Means for Solving the Problems The present inventors have found a screw structure for a crosslinking reaction and a screw structure and an extrusion method for making oil dispersion uniform that satisfy the physical properties, extrusion stability and productivity of a thermoplastic elastomer. Thus, the present invention has been completed.

[0014] The present invention provides: (1) two or more barrel diameter D _b having a kneading zone more than 40mm 136m
m or less, and in the screw configuration of the first kneading zone for crosslinking, (H), (B), and (D) are combined, and if necessary, (C), (E), ( F) and at least one of (G) in combination, the length Lm1 / D of the first kneading zone for crosslinking is 2.0 to 15,
In the screw configuration of the second kneading zone, (A), (B), (D), (F) or (G) are combined, and if necessary, at least one of (C), (E), and (H) is further added. Kneading zone length Lm2 / screw outer diameter D
Wherein the rubber oil addition inlet is provided at least one in the extruder barrel between Lm2 / 2 of the first kneading zone and Lm2 / 2 in the second kneading zone. Machine.

(A) A cutting disk having a twisting angle of (30 / Nt) degrees to (150 / Nt) degrees and a blade width of 4 to 13 mm per sheet. (B) A cutting disk. Twist angle of (160
/ Nt) degree to (220 / Nt) degree, and a nying disc having a blade width Lb / D = 0.08 to 0.4 per sheet. (C) The twisting angle of the nying disc is (-20).
/ Nt) degree to (20 / Nt) degree, and a needing disk having a blade width Lc / D = 0.3 to 2 per sheet. (D) The twisting angle of the needing disk is (240)
/ Nt) degree to (330 / Nt) degree, and a needing disk having a blade width Ld / D of 0.08 to 0.4 per sheet. Mixing screw with notches of up to 15 places and screw element length Le / D = 0.3 to 2 (F) Lead length L / D = 0.4 to 2 and screw length Lf / D = 0.3 (G) Screw length Lg / D = 0.3 to 2 varistoring (H) The twisting angle of the leading disk is (30 /
(Nt) degrees to (150 / Nt) degrees, and a needing disk having a blade width of 13.2 to 40 mm per sheet.

(A), (B), (C), (D) and (H)
The numerical value of Nt described is 2 and / or 3.

(2) In the extruder according to the above (1),
The addition position of the oil injection port is 1 /
An extruder for a thermoplastic elastomer, wherein the extruder is 4 to 2/3.

(3) From the main hopper of the extruder according to the above (1) or (2), (1) ethylene and at least one or more carbon atoms of 3
Olefinic elastomer comprising α-olefins of at least 12 and ethylene and at least one or more carbon atoms having 3 carbon atoms.
Olefin elastomers composed of α-olefins and non-conjugated dienes, block copolymers composed of vinyl aromatics and conjugated dienes, and hydrogenated block copolymers composed of vinyl aromatics and conjugated dienes. 5 to 95 parts by weight of one or more selected crosslinkable elastomers (2) 95 to 5 parts by weight of propylene-based polymer (total amount of (1) and (2) is 100 parts by weight) (3) Radical initiator 0.02 to 3 parts by weight of a radical initiator or 0.02 to 3 parts by weight of a radical initiator and 0.1 to 5 parts by weight of a cross-linking aid are added. Add from the inlet, and reduce the total extrusion amount to dimensionless extrusion amount Q * =
0.006 to 0.02 and the rotation speed is 150 rpm to 6
A method for producing a thermoplastic elastomer composition, wherein the composition is extruded at 00 rpm.

(4) The method for producing a thermoplastic elastomer composition according to the above (3), wherein (1) and (3) are preblended and (2) is supplied by different supply devices.

(5) The olefin elastomer comprising ethylene and α-olefin comprises ethylene and at least one α-olefin having 6 to 12 carbon atoms, and has a density of 0.8 to 0.9 g / cm ³ . Range,
And gel permeation chromatography (GP
Molecular weight distribution (Mw / Mn), which is the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) calculated by C)
Is a olefinic elastomer having a molecular weight of less than 3.0, the method for producing a thermoplastic elastomer composition according to the above (3) or (4).

Further, the present invention will be described with reference to FIGS.

In FIG. 1, 1 is an extruder, 2 is a main hopper, 3 and 4 are feeders, 5 is a liquid addition nozzle, 6 is a liquid addition pump, and 7 is a liquid addition tank.

The extruder 1 of the present invention is a twin-screw extruder so that a sufficient conveying force for the thermoplastic elastomer can be obtained.
Generally, it is a co-rotating type.

The extruder 1 of the present invention is generally used to obtain a pellet resin, but the present invention is not limited to this, and may be a sheet or film-forming machine. . For example, ZSK series manufactured by Warner & Friedler, TEM manufactured by Toshiba Machine Co., Ltd.
And TEX series manufactured by Nippon Steel Corporation. The barrel diameter of the extruder of the present invention is 40 to 136 mm. When the barrel diameter is smaller than 40 mm, 13.2 to 40 mm
When the kneading disk is manufactured, it is not preferable because the kneading disk is excessively sheared and the kneading disk is easily broken due to insufficient strength of the kneading disk. When the barrel diameter is larger than 136 mm, the blade width per one kneading disc is 40.
mm is not preferable.

The length of the extruder 1 of the present invention is Lex /
D (Lex = extruder length, D = screw diameter) is 10
Preferably, the length is 80. Lex / D is 1
If the value is less than 0, degassing and side feeding are difficult to occur, and if the Lex / D of the extruder 1 of the present invention exceeds 80, the residence time of the resin is prolonged and the resin is likely to deteriorate.

In the present invention, the screw structure of the melting zone of the first kneading zone, the screw structure of the second kneading zone and the screw structure of the second kneading zone, and the oil addition position are particularly significant.

The definitions of the first kneading zone and the second kneading zone of the present invention will be described with reference to FIGS. The location of the rubber oil inlet is shown in FIG.

The first kneading zone is the first kneading zone downstream from the hopper. Screw parts consist of a combination of screws (B) to (H),
(H), (B) and (D) are mandatory, and in some cases,
(C), (E), (F) and (G) are appropriately combined.
The length of the kneading zone is Lm1 / D = 2.0-15.
Preferably, Lm1 / D = 2.5-12. Lm1 /
When D is shorter than 2.0, poor dispersion of the radical initiator occurs, and when Lm1 / D is longer than 15, the resin temperature becomes too high. The second kneading zone is composed of a combination of screws (A) to (H), and (A), (B) and (D),
(F) or (G) is essential, and in some cases (C),
(E) and (H) are appropriately combined. The length of the kneading zone is Lm2 / D = 10-30. If Lm2 / D is shorter than 10, insufficient kneading of the added oil is caused, and Lm2 / D = 3.
If it is longer than 0, the resin temperature becomes high, which causes embrittlement, which is not desirable.

The rubber oil inlet is located between the uppermost stream of the first kneading zone and Lm2 / 2 of the second kneading zone. Preferably, it is installed between the uppermost stream and Lm2 / 4 from the upstream side of the second kneading zone. More preferably, it is installed between the uppermost stream and the lowermost stream of the first kneading zone.

When injected from the main hopper, surging is apt to occur, and if it is installed downstream from the middle of the second kneading zone, the temperature in the crosslinking reaction zone becomes too high, which undesirably leads to a decrease in physical properties.

The structure of the entire screw and the role of each part are roughly as follows.

First, a screw element usually called a double-thread screw and / or a single-thread screw is used as a screw in a solid transfer zone of an extruder that transfers a solid from a main hopper to a first kneading zone.

Next, in the first kneading zone, the crosslinkable elastomer and the propylene resin or the crosslinkable elastomer and the propylene resin described in the above (4) and (5) supplied from the main hopper 2 shown in FIG. (3) First, kneading and melting are performed with the crosslinking agent described above. Although the position of the first kneading zone depends on the length of the extruder 1 of the present invention, from the center position of the barrel in which the main hopper 2 is provided, Lex / D = 7.0 of the extruder of the present invention. The range is largely smaller than 20. In the second kneading zone, the crosslinking reaction and the rubber oil are melted and kneaded, and the rubber oil is dispersed and mixed so as not to bleed out.

Further, when the second and subsequent rubber oil inlets are present, a kneading zone is present downstream thereof, and the composition and the rubber oil are dispersed and mixed. Further, a resin and an elastomer can be additionally added from a side feeder, and melt kneading can be performed in a kneading zone downstream of the resin and the elastomer.

In the present invention, the calculation of the width La / D of the blade per one piece of the needing disc of (A), (B), (C), (D) and (H) is based on the length of the needing disc. L is divided by the screw diameter D and further divided by the number of blades, and Equation 1 is used.

(Equation 1) Blade Width = Needing Disk Length / (Number of Blades ×
(Screw outer diameter) In the actual needing disk, there is a gap between the blades as in FIG. 3, but in the present invention, Ln / D was determined on the assumption that there was no gap. (The value of n is a for (A),
(In the case of (B), it is assumed that b,...)) Nt of the present invention described in the above (1) is the number of screw screws. FIGS. 3, 4, and 5 show examples of Nt = 2 with a double thread. N
t = 3 means a three-start thread.

As can be seen from the drawing, the two screws have two long diameters and the three screws have three long diameters.

(Equation 2) Maximum shear rate γ γ = π × D × N / Hc D: Outer diameter of barrel mm N: Number of rotations rps Hc: Clearance between barrel and screw tip mm The needing disk (A) ( 3), the number of the blades 3 is two or more, and the twist angle of the blades 3 in FIG. 3 is (30 / Nt) degrees to (150 / Nt) degrees. If the degree is larger than (150 / Nt), the gap between the blades is too wide, and the transport capacity is reduced. Even if it is smaller than (30 / Nt) degrees, the transport capacity is reduced. Preferred torsional angles are 30 degrees, 45 degrees and 60 degrees when Nt = 2 and Nt = 3 when Nt = 2.
At this time, it is 30 degrees. In addition, even if La / D is smaller than 0.08 or larger than La / D = 0.25, the carrying capacity is reduced.

In the needing disk (B) (see FIG. 3) used in the present invention, two or more blades 3 have a twist angle (160 / Nt) to (220 / Nt) degrees. A preferred angle is 90 degrees when Nt = 2 and 60 when Nt = 3.
Degrees. Also, even if La / D is smaller than 0.08, L
Even if a / D is larger than 0.4, the carrying capacity is reduced.

The needing disk (C) (see FIG. 3) used in the present invention has a single blade 3 and a twist angle of (−20 / Nt) to (20 / Nt) degrees. Is 0 degree at both Nt = 2 and Nt = 3. Even if La / D is smaller than 0.3, La / D = 2.0.
If it is larger, the carrying capacity is reduced.

The needing disk (D) (see FIG. 3) used in the present invention is called a needing disk left and has a twist angle of (240 / Nt) to (330 / N).
Nt) degrees, and preferable twist angles are 135 and 150 degrees when Nt = 2 and 90 degrees when Nt = 3.
Even if La / D is smaller than 0.08, La / D =
If it is larger than 0.4, the carrying capacity is reduced.

The needing disk (H) (see FIG. 3) used in the present invention has two or more blades 3, and
Angle of the blade 3 is (30 / Nt) degrees to (150 / Nt).
Nt) degrees. If the degree is larger than (150 / Nt), the gap between the blades is too wide, and the transport capacity is reduced. (30 /
Even if it is smaller than (Nt) degree, the transport capacity is reduced. Preferred torsional angles are 15 degrees, 22.5 degrees when Nt = 2,
It is 30 degrees when Nt = 3 at 30, 45, and 60 degrees. Further, when the blade width is smaller than 14.0 mm, the shearing force becomes small, which is not preferable. If it is larger than 40 mm, the shearing force is excessively applied, which causes deterioration of the resin, which is not preferable.

Mixing screw (E) used in the present invention
(See FIG. 4) is a mixing screw in which a screw mountain (flight portion) is cut out, and examples thereof include a notch-type mixing screw with a forward feed two-thread screw, a reverse-feed single-thread notch-type mixing screw, and the like. . The number of cutouts is preferably 5 to 15 per screw lead. The mixing screw also includes a gear-type mixing screw.

The screw element (F) used in the present invention
(See FIG. 5) is called a reverse screw, and the lead length is L /
D = 0.4 to 2.0 is preferred. The lead length is the length of the screw when the screw rotates 360 degrees,
Leads are sometimes called pitches by extruder manufacturers. If the lead length is shorter than L / D = 0.4, the pressure rises too much, which is not preferable. If the lead length is longer than L / D = 2.0, the pressure gradient decreases, leading to insufficient kneading.

Varistor ring (G) used in the present invention
(See FIG. 6) is also called a seal ring, and the preferable range of the screw major axis and the barrel gap is 0.004 to 0.0.
4. If the gap is too large, the sealing property is deteriorated, and if it is too small, the pressure is too high.

The needing disk (D) (see FIG. 3) used in the present invention has two or more blades 3 and
Angle of the blade 3 is (30 / Nt) degrees to (150 / Nt).
Nt) degrees. If the degree is larger than (150 / Nt), the gap between the blades is too wide, and the transport capacity is reduced. (30 /
Even if it is smaller than (Nt) degree, the transport capacity is reduced. Preferred twist angles are 30 degrees, 45 degrees and 60 when Nt = 2.
The degree is 30 degrees when Nt = 3. Also, Lh / D =
If less than 0.26, no shearing force is applied, and Lh / D
If it is greater than 0.40, the transport capacity decreases.

The length L / D of the screw parts of (E), (F) and (G) is 0.3 to 2.0, and L / D = 2.0
If the length is longer, a strong shear force is generated, which causes deterioration of the resin and breakage of the screw parts.
If the length is shorter than 0.3, the mechanical strength of the screw becomes weak, which is not preferable.

The injection port for the liquid additive is as described in (1) and (2) above.
If the above is satisfied, any barrel of the extruder barrel may be used. As an example, the position of the injection port in FIG.
One is provided on the intermediate plate between. When there are two or more inlets, any position that satisfies (1) and (2) above may be used.

[0049] Several kinds of liquid additives may be put in the same inlet, or liquid additives may be divided into each inlet. During the liquid addition, heating can be performed according to the viscosity of the liquid to be added. As the liquid addition pump 6 for supplying the liquid from the liquid addition tank 7, either a plunger pump or a gear pump may be used. In particular, heating is effective when the viscosity of the oil is high. The extruder 1 may be provided with a side feeder to perform side feed.

One or more vent holes 8 can be provided, and the direction thereof may be either upward or lateral. The shape of the vent port opening is W & P A type and
Those of the Japan Steel Works ZL-J type, ZH-J and the like are preferable.
If the venting is severe, a stopper may be inserted into the vent port, or a screw push-in type vent device may be used.

The dimensionless extrusion amount Q * described in the above (3) is
Equation 3 (Equation 3) Q * = M / (1000 × 3600 × Db × Db × Db ×
2 × π × Ns) M: extrusion amount kg / H Db: barrel diameter m Ns: screw rotation speed rps, if Q * is less than 0.006, the resin temperature is too high, and Q * is from 0.02. If it is large, insufficient kneading will occur.

If the number of rotations is less than 150 rpm, kneading becomes insufficient, and if it is more than 600 rpm, shearing increases and the resin temperature rises, causing thermal degradation of the resin.

Olefinic Elastomer The olefinic elastomer of the present invention is an olefinic elastomer having crosslinkability, and is typically represented by ethylene and at least one carbon atom having 3 to 3 carbon atoms.
There are copolymers of 12 α-olefins, ethylene and at least one or more α-olefins having 3 to 12 carbon atoms and a non-conjugated diene.

Examples of the copolymer of ethylene, α-olefin and non-conjugated diene include ethylene-propylene-non-conjugated diene copolymer (EPDM) and ethylene-butene-non-conjugated diene copolymer. Non-conjugated dienes include, but are not limited to, ethylidene norbornene, methylene norbornene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, and the like.

Examples of the α-olefin having 3 to 12 carbon atoms include propylene, butene-1, pentene-1,
Hexene-1, 4-methylpentene-1, heptene-
1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1 and the like.

The olefin-based elastomer used in the present invention may be a mixture of plural kinds.
Workability can be improved.

As the olefin elastomer, ethylene and at least one or more α-olefins having 6 to 12 carbon atoms are used.
Those using an olefin copolymer have excellent mechanical strength and do not contain a diene component, and thus are desirable without problems such as resistance to environmental degradation.

In particular, as the olefin-based elastomer component, ethylene and at least one or more carbon atoms having 6 to 6 carbon atoms.
Consisting of 12 α-olefins and having a density of 0.8 to 0.9.
g / cm ³ , and the molecular weight distribution (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) calculated by gel permeation chromatography (GPC), is 3. In the case of using a copolymer having a molecular weight of less than 0, the crosslinked site at the time of production of the thermoplastic elastomer composition by dynamic crosslinking is relatively uniform, and the mechanical properties and rubber properties of the composition are generally excellent and uniform. It is preferable because it has excellent properties.

The copolymer having a narrow molecular weight distribution and excellent uniformity as described above can be produced using a metallocene catalyst.

The metallocene-based catalyst is composed of a cyclopentadienyl derivative of a Group IV metal such as titanium or zirconium and a co-catalyst.
Compared with conventional catalysts, for example, Ziegler-based catalysts, the molecular weight distribution of the resulting polymer is narrow, and the distribution of α-olefins having 3 to 12 carbon atoms, which is a comonomer in the copolymer, is uniform. I have.

An olefin elastomer produced by using a metallocene catalyst differs greatly in properties of a polymer obtained from a conventional olefin elastomer using a Ziegler catalyst or the like.

The characteristics of the olefin elastomer using the metallocene polymerization catalyst are listed below. Since the polymerization catalyst has high activity, the composition of the comonomer α-olefin can be greatly increased as compared with the conventional one, and an elastomeric polymer having high flexibility can be obtained even without a plasticizer. 2. Uniform distribution of comonomer compared to Ziegler-based polymer; 3. Extremely sharp molecular weight distribution, extremely low molecular weight components, excellent mechanical strength and processability, and high quality compared to Ziegler polymers. Despite the sharp molecular weight distribution, when a long-chain branch is introduced, the melt index (I10) at 190 ° C./10 kgf specified by ASTM D1238 and the melt index (I2) at 190 ° C./2.16 kgf are obtained. 4. The ratio (I10 / I2) is large, and the processing characteristics are excellent. 5. It does not contain a diene component and has excellent resistance to environmental degradation. Even if the copolymerization ratio of the α-olefin is high, blocking hardly occurs, and a pellet form is possible.

In the case of an olefin-based elastomer which is a copolymer of ethylene and an α-olefin using a Ziegler catalyst, the above-mentioned melt index ratio (I10 / I2) and the molecular weight distribution show a substantially linear proportional relationship. The molecular weight distribution tends to increase with the increase. The molecular weight distribution is usually about 3 to 10.

On the other hand, in the case of an olefin polymer using a metallocene catalyst, the molecular weight distribution is a sharp value of less than 3.0 and the amount of low molecular weight components is extremely small irrespective of the value of the melt index ratio. For this reason, workability is extremely excellent.

The molecular weight distribution of these olefin elastomers is calculated by high-temperature GPC using dichlorobenzene as a solvent.

Further, by modifying the metallocene catalyst, a copolymer having a long chain branch can be obtained.
A copolymer having a long-chain branch is more preferable because it has high flexibility and cross-linking proceeds efficiently, and as a characteristic of the composition after cross-linking, it has excellent rebound resilience, compression set and the like.

Examples of the olefin elastomer comprising ethylene produced by a metallocene catalyst and at least one α-olefin having 6 to 12 carbon atoms include:
Products such as "Engage" from DuPont Dow Elastomers are known.

The olefin elastomer used in the present invention has a melt index of 0.01-10.
Those having a range of 0 g / 10 minutes (190 ° C., 2.16 kg load) are preferably used, and more preferably 0.2 to 10 minutes.
g / 10 minutes. If it exceeds 100 g / 10 minutes, the crosslinking property of the thermoplastic elastomer composition will be insufficient, and if it is less than 0.01 g / 10 minutes, the fluidity will be poor and the processability will be undesirably reduced.

The block copolymer of vinyl aromatic and conjugated diene or the hydrogenated product of block copolymer of vinyl aromatic and conjugated diene can be prepared by any known method for producing the block copolymer of the present invention. For example, a method in which a vinyl aromatic compound and a conjugated diene compound are block-polymerized using a polymerization initiator such as an organic lithium compound in a hydrocarbon solvent.

The block copolymer obtained by hydrogenation can be obtained by subjecting the block copolymer to a hydrogenation reaction. The method of the hydrogenation reaction may be any known method, for example, hydrogenation can be performed in an inert solvent in the presence of a hydrogenation catalyst. The reaction conditions for hydrogenation are selected such that at least 80%, preferably 90% or more, of the conjugated diene compound is hydrogenated, while less than 20%, preferably less than 10%, of the vinyl aromatic compound is hydrogenated. Is done.

A typical example of the hydrogenated block copolymer of the present invention is a block copolymer comprising a styrene block and a butadiene block. Specifically, styrene-butadiene type 2 block copolymer, styrene-butadiene-styrene type 3 block copolymer, and styrene-butadiene-styrene-butadiene 4 type
There are, for example, star-shaped block copolymers and type-2 block copolymers using a coupling agent, all of which are copolymers in which unsaturated portions are hydrogenated by 90% or more with hydrogen. The butadiene 1,2 bond is 20 parts in total butadiene.
５０50% by weight. The ratio of the styrene portion is 20 to 6
0% by weight. The molecular weight is 10,000 to 40 in number average molecular weight.
It is ten thousand.

Another typical example of the hydrogenated block copolymer is composed of a styrene block and an isoprene block, and is composed of a styrene-isoprene type 2 block copolymer and a styrene-isoprene-styrene type 3 block copolymer. A polymer, a styrene-isoprene-styrene-isoprene type 4 block copolymer, and a type 2 block copolymer formed into a star shape using a coupling agent. It is an added copolymer. The isoprene 1, 2 bond is 20 to the total isoprene.
７０70% by weight. The ratio of the styrene portion is 20 to 6
0% by weight. The molecular weight is 10,000 to 40 in number average molecular weight.
It is ten thousand.

The butadiene block or isoprene block of these hydrogenated styrene-based block copolymers is a block copolymerized with butadiene or isoprene as a main component, and may contain other monomers as a polymerization component. . Further, a block obtained by copolymerizing butadiene and isoprene may be used.

The block copolymer of the present invention has mechanical properties as an elastomer, has a high oil holding ability,
In addition, it has a property of crosslinking by a radical initiator.
Accordingly, a large amount of rubber oil can be retained, and a low-hardness composition can be easily obtained.

The melt index of the block copolymer used in the present invention is 0.01 to 100 g / 1.
Those having a range of 0 minutes (190 ° C., 2.16 kg load) are preferably used, and more preferably 0.2 to 10 g / 10.
Minutes. If it exceeds 100 g / 10 minutes, the crosslinkability of the thermoplastic elastomer composition is insufficient, and 0.01% or less.
If it is less than g / 10 minutes, the fluidity is poor and the processability is undesirably reduced.

Propylene Polymer Specific examples of the propylene polymer used in the present invention include homo isotactic polypropylene, propylene and ethylene, butene-1, pentene-1, and hexene-.
And isotactic copolymers (including block and random) with other α-olefins such as 1.

At least one selected from these polymers
More than one polymer is used in a composition ratio of 5 to 95 parts by weight. If the amount is less than 5 parts by weight, the fluidity and processability of the composition decrease, and if it exceeds 95 parts by weight, the flexibility of the composition is insufficient, which is not desirable.

The propylene polymer used in the present invention has a melt index of 0.1 to 100 g / 1.
Those in the range of 0 minutes (230 ° C., 2.16 kg load) are preferably used. If it exceeds 100 g / 10 minutes, the heat resistance and mechanical strength of the thermoplastic elastomer composition will be insufficient, and if it is less than 0.1 g / 10 minutes, the fluidity will be poor and the moldability will be reduced, which is not desirable. .

Rubber Oil The rubber oil used in the present invention is preferably a paraffinic or naphthenic process oil. These are used in an amount of 5 to 250 parts by weight for adjusting the hardness and flexibility of the composition. If the amount is less than 5 parts by weight, flexibility and workability are insufficient, and if it exceeds 250 parts by weight, oil bleeding becomes remarkable, which is not desirable. The rubber oil may be pre-impregnated with the elastomer in the range of 0 to 150 parts by weight.

The thermoplastic elastomer composition provided by the present invention is obtained by combining the above-described specific olefin-based elastomer, block copolymer, propylene-based polymer, and rubber oil in a specific composition ratio. The balance between mechanical strength, flexibility and workability is improved, and it can be preferably used.

Radical Initiator, Crosslinking Aid The thermoplastic elastomer composition provided by the present invention comprises:
It is necessary to partially crosslink the composition with a radical initiator such as an organic peroxide or a radical initiator and a crosslinking aid. Thereby, it becomes possible to further improve the wear resistance, mechanical strength, heat resistance, and the like.

Here, specific examples of the radical initiator preferably used include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane,
1,1-bis (t-hexylperoxy) -3,3,5
-Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-
Butylperoxy) cyclododecane, 1,1-bis (t
-Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,
Peroxy ketals such as 4-bis (t-butylperoxy) butane and n-butyl-4,4-bis (t-butylperoxy) valerate; di-t-butyl peroxide, dicumyl peroxide, t -Butylcumyl peroxide, α, α′-bis (t-butylperoxy-m
-Isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5 Dialkyl peroxides such as -bis (t-butylperoxy) hexyne-3; acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexa Diacyl peroxides such as noyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butylperoxyacetate, t
-Butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate,
Di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate Peroxyesters; and
Hydrogens such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide Peroxides can be mentioned.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.

These radical initiators are used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight of the crosslinkable elastomer. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if it exceeds 3 parts by weight, the physical properties of the composition are not improved, which is not preferable.

Further, as a crosslinking assistant, divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate , Ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinone dioxime, P, P'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N, N'-
m-phenylene bismaleimide, diallyl phthalate,
Tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. These crosslinking aids may be used in combination of two or more.

These crosslinking assistants are used in an amount of 0.1 to 5 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the crosslinkable elastomer.
It is used in an amount of 5 to 2 parts by weight. If the amount is less than 0.1 part by weight, crosslinking is insufficient, and if it exceeds 5 parts by weight, the physical properties of the composition are not improved, and an excessive amount of a crosslinking aid remains, which is not preferable. The addition positions of the radical initiator and the crosslinking assistant are on the upstream side or at the same time as the rubber oil injection port.

As shown in FIG. 2, the radical initiator and the crosslinking assistant may be supplied to the barrel 1 by a liquid adding pump, or may be provided in the first kneading zone upstream of the rubber oil inlet. Also, it may be added at the same position as the oil inlet. The feed method is
The radical initiator and the crosslinking aid may be fed at the same time, or may be fed separately at different positions. Further, the radical initiator and the crosslinking assistant may be added to the elastomer in advance and mixed.

Further, other resins and elastomers may be added to the thermoplastic elastomer composition of the present invention to such an extent that its characteristics are not impaired. For example, polyethylene, polybutene, polyisobutene, a block copolymer of an aromatic vinyl compound-conjugated diene compound, an ethylene-vinyl ester copolymer such as an ethylene-vinyl acetate copolymer, and an ethylene such as an ethylene-ethyl acrylate copolymer -Unsaturated carboxylic acid ester copolymers, ethylene-vinyl alcohol copolymers and the like.

The thermoplastic elastomer composition of the present invention can contain an inorganic filler and a plasticizer to such an extent that the characteristics thereof are not impaired. Examples of the inorganic filler used here include calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide. Examples of the plasticizer include phthalic acid esters such as polyethylene glycol and dioctyl phthalate (DOP). In addition, other additives, for example, organic and inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers,
Flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents and the like are also suitably used. Additives such as these resins, elastomers, inorganic fillers, plasticizers and the like may be fed sideways or may be fed from a main feeder.

[0090]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In particular, the screw configuration is merely an example.

Table 1 shows the screw parts used.

[0092]

[Table 1]

In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows.

(1) Resin temperature in extruder A thermocouple was placed in an intermediate plate between barrels 6 and 7 and measured.

(2) Separation of Oil The strand at the exit of the die was observed and judged.

(3) Compression set (C-Set) [%] Evaluation was made at 70 ° C. for 22 hours according to JIS K6301.

(4) Tensile strength and elongation Dumbbells were processed with FANAC 50D and ASTM648
Was measured at a tensile speed of 5 mm, manufactured by Toyo Seiki Co., Ltd.

(5) Extruder Torque The average value of the upper limit and the lower limit of the torque indicator (in%) of the extruder was taken.

In preparing the thermoplastic elastomer compositions of Examples and Comparative Examples, the present inventors used the following.

Component (a) Olefin-based elastomer Engage 8180 manufactured by Dupont Dow Elastomers Copolymer of ethylene and octene-1, density: 0.86
g / cm ³ , Mw / Mn = 2.4, ASTM D123
8 Melt index 0.5 ASTM D2240 Hardness (Type A) 65 components (b) Propylene polymer Isotactic polypropylene resin MA2 ASTM D1238 manufactured by Nippon Polychem Co., Ltd. 15 components of melt index (c) Paraffin oil Diana Process manufactured by Idemitsu Kosan Co., Ltd. Oil PW-90 component (2) Radical initiator 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane Perhexa 25B component manufactured by NOF Corporation (e) Crosslinking assistant divinylbenzene

[0101]

EXAMPLES Examples 1 to 11 and Comparative Examples 1 to 7 As an extruder, a twin screw extruder (ZSK-40, manufactured by W & P, Germany, Lex / D) in which oil injection ports are attached to barrels 4, 5, and 8 = 47, 11 barrels, barrel diameter 40.
3 mm) (FIG. 2).

100 parts by weight of the olefin-based elastomer (a) /0.3 part by weight of the radical initiator (d) / 1 part by weight of the crosslinking aid (e) were blended by a blender and put into a gravimetric feeder. Set to .52 kg / H. The propylene polymer (b) is charged into a weight feeder. Set the gravimetric feeder to 12.96 kg / H.

(C) is the injection port of the liquid additive in the barrel 4 (the middle of the uppermost stream screw part h in the first kneading zone).
Using a gear pump, 70 parts by weight (26 kg / H) is added. The set temperature of the barrels 2 to 11 is set to 220 ° C., and the rotation speed is set to 295 rpm. The overall throughput is 76.48
kg / H and the dimensionless extrusion rate were 0.0105.

In each of the examples and comparative examples, unless otherwise specified, the same conditions were used. The pellet was pelletized to obtain an elastomer composition pellet. Table 2 shows the screw configuration of each example and comparative example.

[0105]

[Table 2]

In Examples 1 to 7, when the screw structure and the screw parts of the present invention were used, the temperature of the intermediate resin was 235.
At ~ 240 ° C, tensile strength, tensile elongation, permanent compression set, and oil bleed were also good.

Comparative Example 1 The most upstream kneading disk in the first kneading zone of Example 1 was changed from (H) to (A). When the blade width was reduced, the value of the compression set was lower than that in Example 1.

Comparative Example 2 (a), (b), (d), and (e) of Example 1 were collectively blended, put into a gravimetric feeder, and extruded. The values of compression set, tensile strength and elongation were lower than those of Example 1.

Comparative Example 3 The oil addition position in Example 1 was changed from B4 to B6. The values of tensile strength and elongation were lower than those of Example 1. Also, the value of the torque increased.

Comparative Example 4 The length Lm2 / D of the second kneading zone in Example 1 was 9.92.
I made it. As compared with Example 1, when the strand was observed, oil separation was observed, and the values of tensile strength and elongation were reduced.

Comparative Example 5 The length of the first kneading zone of Example 1 was set to Lm1 / D = 1.5. In comparison with Example 1, when the strand was observed, oil separation was observed, and the values of compression set, tensile strength and elongation were reduced.

Comparative Example 6 The pellets of Example 1 (a) were impregnated with 70 parts of oil, and side injection of oil was stopped. Compared to Example 1,
The value of compression set decreased.

Comparative Example 7 The liquid addition nozzle of Example 1 was changed from B4 to a main hopper provided in barrel 1. The values of tensile strength, elongation, and compression set were lower than those in Example 1.

Example 8 The extrusion amount was increased so that the same torque value as in Comparative Example 4 was obtained.
The extrusion rate increased by 24%.

Example 9 The second kneading zone in Example 1 was set to Lm2 / D = 14.92. Compared with Comparative Example 4, the tensile strength and the elongation were improved.

Example 10 The second kneading zone of Example 1 was divided into two, and three flight screws with a 40 mm lead were inserted between them. As compared with Example 1, almost the same performance was shown.

Example 11 The radical initiator and the crosslinking assistant of Example 1 were mixed with B
Inject from the inlet of No. 4 using a precision plunger pump (liquid chromatography pump). The setting is (d) / (e) = 0.
It was 480 g / H at 3 parts by weight / 1 part by weight. Oil B
5 was injected. The performance was equivalent to that of Example 1.

[0118]

According to the present invention, the thermoplastic elastomer composition obtained through the screw structure and the extrusion method for uniformizing the screw structure and oil dispersion of the crosslinking reaction can improve the physical properties and productivity. .

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an extruder for an olefin-based thermoplastic elastomer according to the present invention.

FIG. 2 is an explanatory diagram of an extruder used in Examples and Comparative Examples.

FIG. 3 shows screw parts (A), (B), (C),
(D) An example of a needing disk (example of a double-start thread).

FIG. 4 shows an example of a mixing screw (E) (an example of a double thread).

FIG. 5 shows an example of a reverse screw part (F) (example of a double thread).

FIG. 6 shows an example of varistoring (G).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Extruder for olefin-based thermoplastic elastomer 2 Main hopper 3, 4 Feeder 5 Liquid addition nozzle 6 Liquid addition tank 7 Liquid addition pump 8 Vent port

Continued on the front page F term (reference) 4F207 AA03 AA11 AA13F AA45 AB03 AR12 AR13 AR15 KA01 KA17 KF01 KF13 KK13 KK34 KL01 KL04 KL05 KL07 KL17 KL22 KL23

Claims (5)

[Claims] 1. A two or more two-axis turning extruder barrel diameter D _b of 40mm or more 136mm or less with kneading zone, the screw configuration of the first kneading zone for crosslinking,
(H), (B) and (D) are combined, and if necessary, at least one of (C), (E), (F) and (G) is further combined, and the length Lm of the first kneading zone for crosslinking is obtained.
1 / D = 2.0-15, and in the screw configuration of the second kneading zone, (A), (B), (D), (F) or (G) are combined, and if necessary, (C) ),
(E), at least one of (H) is combined, the kneading zone length Lm2 / the screw outer diameter D = 10 to 30, and the rubber oil addition inlet is from the uppermost stream of the first kneading zone to the second kneading zone. An extruder for thermoplastic elastomers, wherein at least one is provided in an extruder barrel between Lm2 / 2. (A) The twisting angle of the needing disk is (30 /
(Nt) degree to (150 / Nt) degree, and a blade having a blade width of 4 to 13 mm per sheet. (B) The twisting angle of the needle disk is (160).
/ Nt) degree to (220 / Nt) degree, and a nipping disk having a blade width Lb / D = 0.08 to 0.4 per sheet. (C) The twisting angle of the niping disk is (-20).
/ Nt) degree to (20 / Nt) degree, and a winging disc having a blade width Lc / D = 0.3 to 2 per sheet. (D) The twisting angle of the neading disc is (240)
/ Nt) degrees to (330 / Nt) degrees, and a needing disk having a blade width Ld / D = 0.08 to 0.4 per sheet. Mixing screw with notches of up to 15 places and screw element length Le / D = 0.3 to 2 (F) Lead length L / D = 0.4 to 2 and screw length Lf / D = 0.3 (G) Screw length Lg / D = 0.3 to 2 varistoring (H) The torsion angle of the leading disk is (30 /
(Nt) degree to (150 / Nt) degree, and a needing disk having a blade width of 13.2 to 40 mm per sheet. The numerical value of Nt described in (A), (B), (C), (D), and (H) is 2 and / or 3. 2. The extruder according to claim 1, wherein the position of the oil injection port is 1/4 to 2 of the entire extruder from the upstream side.
/ 3, an extruder for thermoplastic elastomers. 3. The extruder according to claim 1 or 2, wherein (1) ethylene and at least one or more carbon atoms have 3 or more carbon atoms.
Olefinic elastomer comprising α-olefins of at least 12 and ethylene and at least one or more carbon atoms having 3 carbon atoms.
Olefin elastomers composed of α-olefins and non-conjugated dienes, block copolymers composed of vinyl aromatics and conjugated dienes, and hydrogenated block copolymers composed of vinyl aromatics and conjugated dienes. 5 to 95 parts by weight of one or more selected crosslinkable elastomers (2) 95 to 5 parts by weight of propylene-based polymer (total of (1) and (2) is 100 parts by weight) (3) Radical initiator 0.02 to 3 parts by weight of a radical initiator or 0.02 to 3 parts by weight of a radical initiator and 0.1 to 5 parts by weight of a cross-linking aid are added. Add from the inlet, and reduce the total extrusion amount to dimensionless extrusion amount Q * =
0.006 to 0.02 and the rotation speed is 150 rpm to 6
A method for producing a thermoplastic elastomer composition, wherein the composition is extruded at 00 rpm. 4. The method for producing a thermoplastic elastomer composition according to claim 3, wherein (1) and (3) are preblended and (2) is supplied by different supply devices. 5. An olefin elastomer comprising ethylene and α-olefin comprises ethylene and at least one α-olefin having 6 to 12 carbon atoms, and has a density of 0.8 to 0.9 g / cm ³ . And gel permeation chromatography (GPC)
4. An olefin elastomer having a molecular weight distribution (Mw / Mn) of less than 3.0, which is a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn), calculated by the following formula.
Or a method for producing a thermoplastic elastomer composition according to item 4.