JP2002210732A - Method for manufacturing olefin thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing an olefin thermoplastic elastomer composition having excellent tensile strength and molding appearance, and a method capable of manufacturing the olefin thermoplastic elastomer composition for remarkably reducing an appearance of a fish eye (gel-like fine lump). SOLUTION: The method for manufacturing the olefin thermoplastic elastomer composition comprises the step of disposing particularly a needing segment at least at one position of a screw, in the case of dynamically crosslinking and manufacturing the composition made of a polyolefin resin and a crosslinked rubber by using a twin screw extruder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an olefin-based thermoplastic elastomer composition having excellent tensile properties and molded appearance.

[0002]

BACKGROUND OF THE INVENTION Olefin-based thermoplastic elastomers are:
Because it is lightweight and easy to recycle, it is widely used as an energy-saving and resource-saving thermoplastic elastomer, especially as a substitute for soft vinyl chloride and vulcanized rubber, for automobile parts, industrial machinery parts, electronic / electric equipment parts, building materials, etc. ing. However, conventional olefin-based thermoplastic elastomers have a drawback that their tensile strength is inferior to soft vinyl chloride and vulcanized rubber, and improvement thereof has been strongly demanded.

[0003] In the case of sheet molding or profile extrusion molding, the appearance of a molded article is very important, and rough surface of the molded article and poor appearance such as minute projections significantly impair the value of the product. Japanese Patent Application Laid-Open No. 58-25340 discloses a technique for producing an olefin-based thermoplastic elastomer by a dynamic crosslinking method using a twin-screw extruder. Although the appearance of the sheet or the extruded product is greatly improved as compared with the case, it is not always sufficient. It is considered that the reason for this is that kneading at a high shear rate in a twin-screw extruder generates a large amount of heat generated by shearing, and as a result, the cross-linking reaction rapidly proceeds and uneven cross-linking tends to occur.

[0004] Japanese Patent Application Laid-Open No. 9-95540 discloses a method of manufacturing using a screw composed of a specific kneading disc. When the extrusion amount is increased, the above-described poor appearance is likely to occur.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, when a polyolefin resin and a rubber component are dynamically cross-linked using a twin-screw extruder to produce an olefin-based thermoplastic elastomer. By using a screw having a specific kneading segment, shear heat generation can be suppressed, and by performing dynamic crosslinking at an appropriate speed, an olefin-based thermoplastic elastomer composition having excellent tensile strength and molded appearance can be obtained. In addition, when a polyolefin resin and a rubber component are dynamically cross-linked using a twin-screw extruder, and then dynamically cross-linked under specific conditions when producing an olefin-based thermoplastic elastomer, fish eye It has been found that the appearance of (gel-like fine lumps) is significantly reduced, and the present invention has been completed.

[0006]

SUMMARY OF THE INVENTION The present invention aims to solve the problems associated with the prior art as described above, and provides an olefin-based thermoplastic elastomer composition having excellent tensile strength and molded appearance with good productivity. It is an object of the present invention to provide a method that can be produced, and a method that can produce an olefin-based thermoplastic elastomer composition in which the appearance of fish eyes (gel-like fine lumps) has been significantly reduced.

[0007]

The present invention includes the following inventions. (i) At least one kneading segment (α) was arranged when a olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a crosslinked rubber was dynamically crosslinked using a twin-screw extruder and produced. The clearance between the apex of the kneading segment (α) (here, the apex is a point or a part farthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder is determined by using a screw. A method for producing an olefin-based thermoplastic elastomer composition, wherein the composition is 1/60 or more and 1/6 or less.

(Ii) At the downstream of the kneading segment (α), the apex of the kneading segment (here, the apex is a point or a portion at the farthest distance from the center of gravity of the cross section)
And (k) in which the kneading segment (β) is arranged such that the ratio of the clearance between the screw and the clearance between the extruder and the inner wall of the cylinder is smaller than the ratio in the kneading segment (α). The manufacturing method as described.

(Iii) The method according to (ii), wherein the kneading segment (α) and the kneading segment (β) are arranged adjacent to each other. (iv) The clearance between the apex of the kneading segment (α) (where the apex is a point or a portion farthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder is 1/60 of the screw diameter. As described above, the production method according to any one of (i) to (iii), which is 1/10 or less. (v) the clearance between the apex of the kneading segment (β) (where the apex is the point or the part furthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder;
(I) the value of the ratio to the screw diameter is less than 1/60;
The production method according to (i) or (iii).

(Vi) The kneading segment (α) is
The following features: A1) Three vertices (a) in the cross-sectional shape (here, the vertices are the points or portions furthest from the center of gravity of the cross-section) A2) The vertices of the kneading segment Is in the thickness direction,
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
The production method according to any one of the above (i) to (v), comprising:

(Vii) When a thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked using a twin-screw extruder and produced, the following features are provided: A2) the vertex of the kneading segment in the thickness direction has a vertex (a) (where the vertex is a point or a portion at the farthest distance from the center of gravity of the cross section);
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
A method for producing an olefin-based thermoplastic elastomer composition, comprising: disposing a kneading segment (A) having at least one position in a screw.

(Viii) The kneading segment (A) has at least one location and the following features: B1) It has two apexes (b) in the cross-sectional shape (where the apex means a center of gravity of the cross-section) B2) the top of the kneading segment in the thickness direction,
(Vii) The production method according to the above (vii), wherein a screw having a kneading segment (B) having a discontinuously twisted structure is arranged in at least one place.

(Ix) The production method according to (viii), wherein a screw having a configuration in which the kneading segment (B) is arranged downstream of the kneading segment (A) without any other segment is used. (x) Kneading segment (B) without any other segment downstream of kneading segment (A)
(Ix) using the screw in which the combination of the kneading segments (A) and (B) in which is disposed is disposed in at least two places.

(Xi) The clearance between the apex of the kneading segment (A) and the inner wall of the cylinder of the extruder is 1/100 or more and 1/6 or less of the screw diameter.
The production method according to any one of (vii) to (x). (xii) The ratio of the clearance between the apex of the kneading segment (B) (where the apex is the point or the part furthest from the center of gravity of the cross section) to the inner wall of the cylinder of the extruder, and the screw diameter Is less than 1/60, the production method according to any one of the above (viii) to (x). (xiii) at least one of the upstream barrels of the twin screw extruder
The method according to any one of (i) to (xii), wherein the temperature is set to 170 ° C. or lower, and at least one of the downstream barrels is set to 190 ° C. or higher. (xiv)

[0015]

[Equation 2] 4.5 <2.2 log X + log Y-log Z + (T-18
0) ÷ 100 <6.0 (where T is the resin temperature (° C.) at the die outlet of the twin-screw extruder, and X is the screw diameter (m) of the twin-screw extruder.
m), Y is the maximum shear rate (sec ⁻¹ ) generated at the kneading segment (A) in the extruder, and Z is the output (kg / h) of the twin-screw extruder. The maximum shear rate Y (sec ^-1 ) is Y = (X × π × S) /
It is obtained from the equation of U. Here, X is the screw diameter (mm) of the twin-screw extruder, S is the screw rotation speed per second (rps), and U is the distance of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw ( mm). ) That dynamically crosslinks under conditions that satisfy
The production method according to any one of (i) to (xiii). (xv) When an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked using a twin-screw extruder to produce the same, the output of the twin-screw extruder in a steady state, Z (kg) / H) and the diameter X (mm) of the screw of the twin-screw extruder dynamically crosslink under the condition of the following formula: Z / X ^2.3 ≧ 0.01, and 1 in a steady state.
A method for producing an olefin-based thermoplastic elastomer composition, comprising obtaining an olefin-based thermoplastic elastomer composition in which the average number of fish eyes of at least three or more samples sampled every time is 10 or less.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing an olefin-based thermoplastic elastomer composition of the present invention will be specifically described. In the first invention of the present application, when an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked by using a twin-screw extruder and manufactured, at least one kneading segment (α) is used. The clearance between the apex of the kneading segment (α) (here, the apex is a point or a part at the farthest distance from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder is set using the arranged screw. 1/60 of screw diameter
As described above, the present invention provides a method for producing an olefin-based thermoplastic elastomer composition, wherein the composition is 1/6 or less.

The second invention of the present application is characterized in that when an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked by using a twin-screw extruder and produced, the following features: A1) Cross section The shape has three vertices (a) (here, the vertices are points or portions that are the farthest from the center of gravity of the cross section). A2) The vertices of the kneading segment are in the thickness direction.
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
The kneading segment (A) having the following is disposed in at least one place of a screw, and is a method for producing an olefin-based thermoplastic elastomer composition.

The first invention and the second invention of the present application both
It is characterized in that a polyolefin resin and a rubber component are dynamically crosslinked using a twin screw extruder having a specific kneading segment. The third invention of the present application relates to a method for producing an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber by dynamically cross-linking the same using a twin-screw extruder. Z (kg
/ H) and the diameter X (mm) of the screw of the twin-screw extruder dynamically crosslink under the condition of the following formula: Z / X ^2.3 ≧ 0.01, and 1 in a steady state.
A method for producing an olefin-based thermoplastic elastomer composition, characterized by obtaining an olefin-based thermoplastic elastomer composition in which the average number of fish eyes of at least three or more samples sampled every time is 10 or less. .

First, the components forming the olefin-based thermoplastic elastomer composition will be described. (Polyolefin resin) The polyolefin resin used in the present invention comprises a high-molecular-weight solid product obtained by polymerizing one or more monoolefins by either a high-pressure method or a low-pressure method. Such resins include, for example, isotactic and syndiotactic monoolefin polymer resins. These representative resins are commercially available.

Examples of suitable raw olefins for the polyolefin resin include ethylene, propylene,
1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 2-methyl-1-propene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1- Hexene and the like. These olefins are used alone or in combination of two or more.

The polymerization mode may be any type, such as a random type or a block type, as long as a resinous material is obtained. These polyolefin resins may be used alone or in combination of two or more. Among these polyolefin resins, propylene polymers, specifically, propylene homopolymer, propylene
An ethylene block copolymer, a propylene / ethylene random copolymer or a propylene / ethylene / butene random copolymer is particularly preferred.

The polyolefin resin used in the present invention is an MFR (ASTM D1238-65T, 230
° C, load 2.16 kg) is usually 0.01 to 100 g / 1
It is preferably in the range of 0 minute, particularly 0.05 to 50 g / 10 minutes. The polyolefin resin has a role of improving the fluidity and heat resistance of the composition.

In the present invention, the polyolefin resin is a polyolefin resin and a crosslinked rubber in a total amount of 1%.
It is preferably used in an amount of 10 to 80 parts by weight, more preferably 15 to 60 parts by weight, based on 00 parts by weight. When the polyolefin resin is used in the above proportion, a high heat-resistant thermoplastic elastomer composition having excellent flexibility and rubber elasticity and excellent moldability can be obtained.

(Crosslinked Rubber) Examples of the crosslinked rubber used in the present invention include ethylene / α-olefin / non-conjugated polyene copolymer rubber, ethylene / α-olefin copolymer rubber, isoprene rubber and Hydrogenated product, butadiene rubber and hydrogenated product thereof, styrene / butadiene rubber and hydrogenated product thereof, styrene / isoprene rubber and hydrogenated product thereof, chloroprene rubber, butyl rubber, halogenated butyl rubber, polyisobutylene rubber, acrylonitrile / butadiene rubber And at least one rubber selected from the group consisting of chlorinated polyethylene rubber, fluorine rubber, silicone rubber, polysulfide rubber and urethane rubber. Among them, ethylene / α-olefin / non-conjugated polyene copolymer rubber and ethylene / α-olefin copolymer rubber are preferable, and the following characteristics: Ethylene / propylene molar ratio: 30/70 to 90/1
An ethylene / propylene / non-conjugated diene copolymer rubber having an iodine value of 1 to 30 (g / 100 g) and a Mooney viscosity ML1 + 4 (100 ° C.) of 15 to 250 is particularly preferable. In the present invention, the crosslinked rubber is preferably 20 to 90 parts by weight based on 100 parts by weight of the total amount of the polyolefin resin and the crosslinked rubber,
More preferably, it is used in a proportion of 40 to 85 parts by weight.

(Other Components) In addition to the polyolefin resin and the crosslinked rubber, a softener and / or an inorganic filler can be blended with the olefin-based thermoplastic elastomer composition according to the present invention. As the softener, a softener usually used for rubber can be used. Specifically, petroleum softening agents such as process oil, lubricating oil, paraffin oil, liquid paraffin, petroleum asphalt, petrolatum; coal tars such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil, Fatty oils such as bean oil and coconut oil; tall oil; waxes such as beeswax, carnauba wax and lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate and zinc laurate or metal salts thereof; Synthetic polymer substances such as terpene resin, petroleum resin, coumarone indene resin, atactic polypropylene; ester softeners such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate; microcrystalline wax, sub (factice), liquid polybutadiene, modified Liquid polybutadi Emissions, liquid Thiokol, and hydrocarbon-based synthetic lubricating oils.

In the present invention, from the viewpoint of heat resistance of the obtained thermoplastic elastomer composition, the softener is usually 150 parts by weight or less, preferably 150 parts by weight or less, based on 100 parts by weight of the total amount of the polyolefin resin and the crosslinked rubber. It is used in a proportion of 2 to 100 parts by weight, more preferably 5 to 80 parts by weight. When the softening agent is used in the above ratio, the obtained thermoplastic elastomer composition has excellent fluidity at the time of molding and does not lower the mechanical properties of the molded article. In the present invention, the softener may be added during the production of the olefin-based thermoplastic elastomer, or may be oil-extended on the raw rubber in advance.

Specific examples of the inorganic filler include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic Examples include magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass sphere, shirasu balloon, basic magnesium sulfate whisker, calcium titanate whisker, and aluminum borate whisker.

In the present invention, the inorganic filler is usually used in an amount of 100 parts by weight based on the total amount of the polyolefin resin and the crosslinked rubber in view of rubber elasticity and moldability of the thermoplastic elastomer composition obtained. It is used in a proportion of at most 2 parts by weight, preferably 2 to 50 parts by weight. Furthermore, in the present invention, a conventionally known heat-resistant stabilizer, an anti-aging agent, a weather-resistant stabilizer, an antistatic agent; a lubricant such as a metal soap or a wax is added to the olefin-based thermoplastic elastomer composition. Can be added in a range that does not impair.

In the present invention, the olefin-based thermoplastic elastomer composition comprises the above-mentioned polyolefin resin,
It is obtained by mixing a raw rubber of a crosslinked rubber, a softener and / or an inorganic filler compounded as necessary, and then subjecting the mixture to dynamic crosslinking in the presence of a crosslinking agent. Here, "dynamic crosslinking" means that a crosslinking reaction is caused by kneading in a molten state in the presence of a crosslinking agent.

Examples of the crosslinking agent used in the present invention include organic peroxides, phenol resins, sulfur, hydrosilicone compounds, amino resins, quinones or derivatives thereof, amine compounds, azo compounds, epoxy compounds, isocyanates and the like. And crosslinking agents generally used in thermosetting rubbers. Among these crosslinking agents, organic peroxides are particularly preferred.

As the organic peroxide used in the present invention, specifically, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane , 2,5-dimethyl-2,5-di- (tert-
Butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert
-Butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide,
tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide and the like.

Among them, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-di- ( (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene is preferred, and
5-Dimethyl-2,5-di- (tert-butylperoxy) hexane is most preferred.

Such organic peroxides are used in view of the heat resistance, tensile properties, elastic recovery, rebound resilience and moldability of the resulting olefin-based thermoplastic elastomer composition, in terms of the total amount of the polyolefin resin and the crosslinked rubber. 0.02 to 3 parts by weight, preferably 0.05 to 1 part by weight, per 100 parts by weight
It is used in such an amount as to give parts by weight.

In the present invention, sulfur, p-quinonedioxime, p, p'-
Crosslinking such as dibenzoylquinone dioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane, N, N'-m-phenylenebismaleimide, divinylbenzene, triallyl cyanurate Auxiliaries or polyfunctional methacrylate monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate; polyfunctional vinyl monomers such as vinyl butyrate and vinyl stearate Can be blended.

By using a compound as described above,
A uniform and mild crosslinking reaction can be expected. Particularly, in the present invention, divinylbenzene is most preferred. Divinylbenzene is easy to handle, has good compatibility with rubber components such as polyolefin resin and ethylene / α-olefin / non-conjugated polyene copolymer rubber, which are the main components of the crosslinked product, and has an organic property. Since it has a function of solubilizing peroxide and acts as a dispersant for organic peroxide, a thermoplastic elastomer composition having a uniform cross-linking effect by heat treatment and a good balance between fluidity and physical properties can be obtained.

The above-mentioned compound such as a crosslinking aid or a polyfunctional vinyl monomer is used in an amount of usually not more than 2 parts by weight, preferably not more than 0.2 parts by weight, based on 100 parts by weight of the total amount of the polyolefin resin and the crosslinked rubber. It is used in an amount of 1 part by weight. In order to accelerate the decomposition of organic peroxides, tertiary amines such as triethylamine, tributylamine, 2,4,6-tri (dimethylamino) phenol, aluminum, cobalt, vanadium, copper, calcium, zirconium, Decomposition accelerators such as naphthenates such as manganese, magnesium, lead, and mercury may be used.

The dynamic crosslinking (heat treatment) in the first and second aspects of the present invention is performed in a twin-screw extruder having a specific kneading segment. This dynamic crosslinking is carried out with nitrogen,
It is preferable to carry out in an atmosphere of an inert gas such as carbon dioxide. The temperature of the extruder is in the range of 300 ° C. from the melting point or softening point of the polyolefin resin, and is usually 100 to 250.
° C, preferably 140 to 225 ° C.

In the first invention of the present application, in order to optimize the kneading conditions and the dynamic crosslinking reaction rate, the apex of the kneading segment (α) (here, the apex is furthest from the center of gravity of the cross section) The clearance between the point or the portion at a distance) and the inner wall of the cylinder of the extruder is 1/60 or more, preferably 2/100 or more of the screw diameter, and 1/6 or less, preferably 1/10 of the screw diameter.
Or less, more preferably 7/100 or less. That is, the clearance is 1/60 or more of the screw diameter,
/ 6 or less, for example, preferably 1/60 or more and 1/10 or less, more preferably 2/100 or more and 7/100 or less.

Further, in the first invention of the present application, in order to perform effective kneading, the apex portion of the kneading segment (here, the apex portion is the most abundant from the center of gravity of the cross section) downstream of the kneading segment (α). A point or part at a distance)
It is preferable to arrange the kneading segment (β) such that the ratio of the clearance between the screw and the clearance between the screw and the inner wall of the extruder and the screw diameter is smaller than the ratio in the kneading segment (α).

In the first and second aspects of the present invention, at least one of the upstream barrels of the twin-screw extruder has a temperature of 170 ° C. or less, and the downstream barrel has the advantage of optimizing the dynamic crosslinking reaction rate. It is preferable to set at least one of them to a temperature of 190 ° C. or higher. Here, upstream refers to the feed hopper side from the middle point, and downstream refers to the die side from the middle point.

The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. The applied shearing force is 10 to 1 at the shearing rate applied at the specific kneading segment (α) or kneading segment (A).
000 sec ⁻¹ , preferably 100 to 2,000 s
ec ^-1, more preferably in the range of 200～1000Sec ^-1, the specific kneading segment (beta) or kneading segment (B) 100~50,000sec ^-1 at a shear rate applied in, preferably 200 ~
10,000 sec ^-1 , more preferably 500 to 5,0
The range is 00 sec ^-1 . Dynamic crosslinking is of the formula:

[0042]

4.5 <2.2 log X + log Y-log Z + (T-18
0) ÷ 100 <6.0 (where T is the resin temperature (° C.) at the die outlet of the twin-screw extruder, and X is the screw diameter (m) of the twin-screw extruder.
m), Y is the maximum shear rate (sec ⁻¹ ) generated at the kneading segment (A) in the extruder, and Z is the output (kg / h) of the twin-screw extruder. The maximum shear rate Y (sec ^-1 ) is Y = (X × π × S) /
It is obtained from the equation of U. Here, X is the screw diameter (mm) of the twin-screw extruder, S is the screw rotation speed per second (rps), and U is the distance of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw ( mm). It is preferable to carry out under the conditions satisfying (3).

By dynamically cross-linking under the conditions satisfying the above formula, it is possible to produce an elastomer composition having excellent compatibility of each component constituting the olefin-based thermoplastic elastomer composition, and excellent in tensile strength and molded appearance. it can. The twin-screw extruder that can be used in the present invention is one in which two screws rotate in the same direction, one in different directions, or one in which two screws are fully or partially engaged, one that is not engaged, and the like. Any one may be mentioned, and among them, those in which the screw rotation direction is the same direction and two screws are completely or partially engaged with each other are preferable. The ratio (L / D) of the length (L) to the diameter (D) of the screw of the twin-screw extruder used in the present invention is usually 25.
~ 70, preferably 30 ~ 65, more preferably 35 ~
60.

Next, the kneading segment used in the present invention will be described. Kneading segment (α) The kneading segment (α) used in the first invention of the present application has the same characteristics as the kneading segment (A) used in the second invention of the present application, that is, the following characteristics: A1) Cross-sectional shape Has three vertices (a) (here, the vertices are points or portions located at the farthest distance from the center of gravity of the cross section). A2) The vertices of the kneading segment are in the thickness direction,
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
Are preferred.

Kneading segment (β) The kneading segment (β) preferably used in the first invention of the present application is obtained by damming the material to be kneaded to the downstream side and retaining it in the kneading segment (α). In terms of effective kneading, the ratio of the screw diameter to the clearance between the apex (where the apex is the point or the part furthest from the center of gravity of the cross section) and the inner wall of the extruder cylinder is described. Preferably, the value is less than 1/60. In the first invention of the present application, it is preferable that the kneading segment (α) and the kneading segment (β) are arranged adjacent to each other in terms of effective kneading.

As the kneading segment (β),
Features similar to those of the kneading segment (B) used in the second invention of the present application, that is, the following features: B1) The cross-sectional shape has two apexes (b) (here, the apex means the center of gravity of the cross-section) B2) the top of the kneading segment in the thickness direction,
It preferably has a discontinuously twisted structure.

Kneading segment (A) <FIG. 1> The kneading segment (A) used in the second invention of the present application has three apex portions (a) in a sectional shape. Here, the apex portion is a point or a portion located at the farthest distance from the center of gravity of the cross section. The kneading segment (A) has a portion (a) whose apex portion is continuously twisted in the thickness direction and continuously in the direction opposite to the screw rotation direction.
1) and a portion (a2) that is continuously twisted in the same direction as the screw rotation direction. Further, the thickness of the kneading segment (the sum of the thickness of a1 and the thickness of a2) is at least 1.0 times, preferably at least 2.0 times the screw diameter.

In order to optimize the kneading conditions and the dynamic crosslinking reaction rate, the clearance between the apex and the inner wall of the cylinder is preferably 1/100 or more, more preferably 1/60 or more, of the screw diameter. Preferably 2 /
It is 100 or more, and preferably 1/6 or less, more preferably 1/10 or less, more preferably 7/100 or less of the screw diameter. For example, the clearance is preferably 1/100 or more and 1/6 or less of the screw diameter, more preferably 1/100 or more, 1/10 or less, or 1/60 or more and 1/6 or less. More preferably, it is 2/100 or more and 7/100 or less.

Kneading segment (B) <FIG. 2> The kneading segment (B) preferably used in the second invention of the present application is a so-called two-section type kneading disk, and has two apexes in a sectional shape. (B). Here, the apex portion is a point or a portion located at the farthest distance from the center of gravity of the cross section. Further, the disk is usually composed of a plurality of disks, and the apexes of the adjacent disks are discontinuously twisted in the thickness direction. The direction of the twist may be the same as or different from the direction of rotation. Feeding adjacent discs twisted by less than 90 degrees in the direction opposite to the rotation direction from the upstream side to the downstream side (forward feeding)
Kneading segment (BR), a kneading segment twisted at less than 90 degrees in the same direction as the rotation direction (reverse feed), a kneading segment twisted at 90 degrees (neutral) (BN).

In the second invention of the present application, in order to perform effective kneading, it is preferable that the kneading segment (A) and the kneading segment (B) are each arranged at one or more screws, preferably at two or more screws. Is more preferred. In that case, it is preferable to arrange the kneading segment (B) on the downstream side of the kneading segment (A) without any other segment from the viewpoint of performing more effective kneading. In that case, a returning kneading segment (BR) or a neutral kneading segment (BN) is located downstream of the kneading segment (A).
It is preferable to increase the number of objects to be kneaded staying in the kneading segment (A) to improve the kneading efficiency.

By dynamically cross-linking using a twin-screw extruder having a screw in which the above-described kneading segment is arranged, an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber can be obtained. In the third invention of the present application, when an olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked using a twin-screw extruder to produce the same, the output of the twin-screw extruder in a steady state is Z (kg /
h) and the diameter X (mm) of the screw of the twin-screw extruder are dynamically crosslinked under the condition of the following formula: Z / X ^2.3 ≧ 0.01, so that the average number of fish eyes is 10 The following olefin-based thermoplastic elastomer composition can be obtained.

Here, the "steady state" refers to a state in which the conditions of the extruder are substantially stable and a substantially uniform thermoplastic elastomer composition is obtained. In the third invention of the present application, it is preferable to combine with the first invention or the second invention of the present application. Specifically, in the third invention of the present application, it is preferable to use a twin-screw extruder having a kneading segment (α) or a kneading segment (A) as described above in the first or second invention of the present application. In particular, the maximum shear rate Y (sec) generated in the kneading segment (α) or the kneading segment (A) portion.
^-1 ) is 10 to 10,000 sec ^-1 , preferably 100
2,000 sec ^-1 , more preferably 200-1,0
It is preferably 00 sec ^-1 . In the present invention, the fact that the rubber in the olefin-based thermoplastic elastomer composition is crosslinked means that the gel content measured by the following method is preferably 20% by weight or more, particularly preferably 45% by weight.
It means that it is within the above range.

[Measurement Method of Gel Content] A 100 mg sample of the thermoplastic elastomer composition was collected and 0.5 mm
A sample cut into × 0.5 mm × 0.5 mm strips was placed in 30 ml of cyclohexane at 23 ° C. for 48 hours in a closed container.
After soaking for a period of time, the sample is taken out on a filter paper and dried at room temperature for at least 72 hours until a constant weight is obtained. The value obtained by subtracting the weight of all cyclohexane-insoluble components (fibrous fillers, fillers, pigments, etc.) other than the polymer component and the weight of the polyolefin resin in the sample before cyclohexane immersion from the weight of this dried residue is referred to as "corrected". Final weight (Y) ".

On the other hand, the weight of the rubber in the sample is referred to as “corrected initial weight (X)”. Here, the gel content is determined by the following equation. Gel content [% by weight] = [corrected final weight (Y) / corrected initial weight (X)] × 100

[0055]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method of the physical property performed about the olefin-type thermoplastic elastomer composition of an Example and a comparative example is as follows.

[Method of measuring physical properties] (1) Tensile strength: 200 in accordance with JIS K6301
The tensile strength at break was measured at a tensile speed of mm / min. (2) Elongation at break: 200 in accordance with JIS K6301
The breaking elongation at break was measured at a tensile speed of mm / min. (3) Number of gel particles: 100 pressed at 190 ° C.
A sheet of × 100 × 0.5 mm was placed on glass, and the number of gel particles having a size of 0.3 × 0.1 mm or more was carefully examined using a graduated loupe while shining light from below. (4) Fish eye measurement method A press sheet of 100 × 100 × 0.5 mm was prepared,
Placed on the glass of the box shown in FIG. 4, and illuminated with fluorescent light from below, the scale in the press sheet was pressed with a graduated loupe.
Fish eye particles of 3 × 0.1 mm or more were searched for and counted. One hour after the steady state was reached, the average number of fish eyes of five samples sampled every hour was obtained and shown in Table 1 (the average number is rounded off and expressed as an integer).

Example 1 Ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber (R-1; Mooney viscosity ML1 + 4 (100 ° C.) 94, ethylene / propylene molar ratio 78/22, iodine 13) of a propylene homopolymer 1 (MFR (ASTM D
1238-65T, 230 ° C, load 2.16 kg) 11
g / 10 min, density 0.91 g / cm ³ ) pellet 25
Parts by weight, 0.2 parts by weight of 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 0.3 of divinylbenzene
3 parts by weight with a Henschel mixer.
The screw shown in (a) was loaded into a hopper of a twin-screw extruder and subjected to dynamic crosslinking under the following conditions to produce thermoplastic elastomer pellets.

Extruder: Full intermeshing twin-screw extruder (in the same rotation direction) Screw diameter: 46 mm Thickness of kneading segment (total thickness of a1 and thickness of a2): 108 mm L / D: 44 Set temperature: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / C9 / C10 / C11 / D = 12
0/120/140/140/160/180/200/220/220/220/220/200
(° C.) Number of revolutions: 400 rpm Extrusion amount: 100 kg / h Then, the obtained pellets were press-formed at 190 ° C.
Physical properties were measured by punching into a predetermined shape. Table 1 shows the results
Shown in

Comparative Example 1 Thermoplastic elastomer pellets were produced from the same raw materials and composition as in Example 1 using the same extruder as in Example 1. However, the screw shown in FIG. 3 (b) was used. Physical properties were measured in the same manner as in Example 1. Table 1 shows the results. (Example 2) Oil-extended product of ethylene / propylene / dicyclopentadiene copolymer rubber (R-2; Mooney viscosity ML)
1 + 4 (100 ° C) 70, ethylene / propylene molar ratio 79
/ 21, iodine value 13, oil extension amount 40 parts by weight (paraffin-based process oil manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process PW-380) 60 parts by weight, propylene / ethylene block copolymer (MFR ( ASTM
D1238-65T, 230 ° C, load 2.16kg)
25 parts by weight of pellets of 15 g / 10 min, density 0.91 g / cm ³ , extraction amount of n-decane 8.2 wt%), an ethylene / 1-hexene random copolymer (MFR (ASTM D
1238-65T, 190 ° C.) 18 g / 10 min, density 0.92 g / cm ³ , ethylene content 97 mol%) pellets 15 parts by weight, 2,5-dimethyl-2,5-di- (tert-butylperoxy) 0.2 parts by weight of hexane and 0.3 parts by weight of divinylbenzene were sufficiently stirred and mixed with a Henschel mixer, and then charged into a hopper of a twin-screw extruder equipped with a screw as shown in FIG. Crosslinking was carried out to produce thermoplastic elastomer pellets.

Extruder: Completely intermeshing type twin screw extruder (in the same rotation direction) Screw diameter: 46 mm Thickness of kneading segment (total thickness of a1 and thickness of a2): 108 mm L / D: 44 Set temperature: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / C9 / C10 / C11 / D = 12
0/120/140/140/160/160/180/220/220/220/220/200
(° C.) Number of rotations: 450 rpm Extrusion amount: 90 kg / h Next, physical properties were measured in the same manner as in Example 1 using the obtained pellets. Table 1 shows the results.

Comparative Example 2 Thermoplastic elastomer pellets were produced from the same raw materials and composition as in Example 2 using the same extruder as in Example 2. However, the screw shown in FIG. 3D was used. Physical properties were measured in the same manner as in Example 1. Table 1 shows the results.

Example 3 Oil-extended ethylene-propylene / 5-ethylidene-2-norbornene copolymer rubber (R-
3: Mooney viscosity ML1 + 4 (100 ° C.) 70, ethylene / propylene molar ratio 80/20, iodine value 11, oil extension 4
0 parts by weight (paraffin-based process oil manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process PW-380), 70 parts by weight of pellets, propylene homopolymer 2 (MFR (AS)
TMD 1238-65T, 230 ° C, load 2.16k
g) 30 parts by weight of pellets of 2 g / 10 min, density of 0.91 g / cm ³ ) and 0.2 part by weight of N, N'-m-phenylenebismaleimide were sufficiently stirred and mixed with a Henschel mixer.
The screw shown in FIG. 3 (e) was charged into the hopper of the twin-screw extruder and fed to the first feed port of the extruder at 120 kg / h, and 2,5-dimethyl-2,5-di- (tert- Butylperoxy) hexane as a softener (paraffin-based process oil manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process PW-
The mixture diluted to 380) to 30% by weight was fed at 240 g / h to the second supply port to perform dynamic crosslinking under the following conditions, thereby producing thermoplastic elastomer pellets.

Extruder: Completely intermeshing type twin screw extruder (in the same rotation direction) Screw diameter: 46 mm Thickness of kneading segment (sum of thickness of a1 and thickness of a2): 108 mm L / D: 44 Set temperature: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / C9 / C10 / C11 / D = 12
0/120/140/140/160/160/180/220/220/220/220/200
(° C.) Number of rotations: 350 rpm Extrusion amount: 120 kg / h Next, physical properties were measured in the same manner as in Example 1 using the obtained pellets. Table 1 shows the results.

(Comparative Example 3) Pellets of a thermoplastic elastomer were produced from the same raw materials and composition as in Example 3 using the same extruder as in Example 3 described in JP-A-9-095540. However, the screw shown in FIG. 3 (f) was used. Physical properties were measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 4 Thermoplastic elastomer pellets were produced from the same raw materials and composition as in Example 3 using the same extruder as in Example 3. However, the operating conditions of the extruder were as shown in Table 1. Physical properties were measured in the same manner as in Example 1. Table 1 shows the results. (Screw rotation speed: 150 rpm)

(Comparative Example 5) Pellets of thermoplastic elastomer were produced from the same raw materials and composition as in Example 2 using the same extruder as in Example 2. However, the operating conditions of the extruder were as shown in Table 1. Physical properties were measured in the same manner as in Example 1. Table 1 shows the results. (Screw rotation speed: 540 rpm)

[0067]

[Table 1] Organic peroxide: 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane Softener: Idemitsu Kosan Co., Ltd. paraffin-based process oil, trade name: Diana Process PW-380 T: Biaxial Resin temperature at exit of die of extruder (° C) X: Diameter of screw of twin screw extruder (mm) Y: Maximum shear rate (sec ^-1 ) generated at kneading segment (A) in extruder Z: The output of the twin-screw extruder (kg / h) U: the distance of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw (mm) Formula (1): 2.2 log X + log Y-log Z + ( T-180) ÷
100 Equation (2): Z / X ^2.3

[0068]

According to the present invention, an olefin-based thermoplastic elastomer composition having excellent tensile properties and molded appearance can be produced with high productivity. Since the olefin-based thermoplastic elastomer composition produced by the present invention has the above-mentioned excellent properties, it can be used for interior skin materials such as automobile instrument panels, doors, ceilings, seats, etc .; Exterior parts such as roof moldings, side moldings, window moldings and roof moldings; various sealing parts such as automotive glass run channels and weather strips; various gaskets, sealing parts and sheets in the field of civil engineering and construction materials; Can be used.

[Brief description of the drawings]

FIG. 1 (1-A) is a cross-sectional view of a kneading segment (A) of a twin-screw extruder, and (1-B) is a vertical cross-sectional view of a kneading segment (A) of a twin-screw extruder.

FIG. 2 (BF) is a schematic diagram of a kneading segment of forward (forward), (BR) is a schematic diagram of a kneading segment of backward (reverse), and (BN) is a schematic diagram of a kneading segment of neutral (orthogonal). It is a schematic diagram. The flow direction of the resin is a direction from the front to the back of the paper.

FIG. 3 is a view showing a screw arrangement used in Examples and Comparative Examples. (A) is Example 1, (b) is Comparative Example 1, (c) is Example 2 and Comparative Example 5, (d) is Comparative Example 2, (e) is Example 3 and Comparative Example 4, (f) ) Indicates the screw arrangement used in Comparative Example 3.

FIG. 4 is a diagram for explaining a method of measuring fish eyes.

[Explanation of symbols]

r Screw rotation direction s Resin flow direction c Clearance a1 Part continuously twisted in the opposite direction to the screw rotation direction a2 Part continuously twisted in the same direction as the screw rotation direction 1 First supply Port 2 second supply port 3 vent port F kneading segment for feed (forward) R kneading segment for return (reverse feed) N kneading segment for neutral (orthogonal) 4 press sheet 5 glass 6 fluorescent lamp

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 23:00 B29K 23:00 F term (Reference) 4F070 AA04 AA12 AA15 AA16 AB11 AB16 GA05 GB08 GC07 4F201 AA03 AA09 AA11 AA45 AB03 AM25 AR06 BK02 BK13 BK27 BK40 BK49 BN37 4J002 AC03X AC06X AC07X AC08X AC09X AC11X BB00W BB02W BB11W BB12W BB15W BB15X BB17W BB18X BB24X BD12X CK02X FD02 FD02

Claims (15)

[Claims] 1. An olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a crosslinked rubber,
When producing by dynamically crosslinking using a twin-screw extruder, a screw having at least one kneading segment (α) is used, and the top of the kneading segment (α) (here, the top The clearance between the point or the part farthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder is 1/60 or more and 1/6 of the screw diameter.
A method for producing an olefin-based thermoplastic elastomer composition, comprising: 2. The apex of the kneading segment downstream of the kneading segment (α) (where the apex is a point or a portion that is the farthest from the center of gravity of the cross section)
The kneading segment (β) according to claim 1, wherein a ratio of a clearance between the screw and the clearance between the screw and the inner wall of the extruder and the screw diameter is smaller than the ratio of the kneading segment (α). Production method. 3. The method according to claim 2, wherein the kneading segment (α) and the kneading segment (β) are arranged adjacent to each other. 4. The clearance between the apex of the kneading segment (α) (where the apex is a point or a part furthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder is 1 mm of the screw diameter. The method according to any one of claims 1 to 3, which is not less than / 60 and not more than 1/10. 5. A clearance between an apex of the kneading segment (β) (where the apex is a point or a portion furthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder, and a screw diameter. The method according to claim 2 or 3, wherein the value of the ratio is less than 1/60. 6. The kneading segment (α) has the following features: A1) Three vertices (a) in a cross-sectional shape (where the vertices are the distances farthest from the center of gravity of the cross section) A2) A vertex of the kneading segment extends in the thickness direction,
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
The production method according to any one of claims 1 to 5, comprising: 7. An olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a crosslinked rubber,
The following features are obtained when dynamically cross-linking and manufacturing using a twin-screw extruder: A1) It has three vertices (a) in the cross-sectional shape (where the vertices are the furthest away from the center of gravity of the cross-section) A2) a vertex of the kneading segment in the thickness direction,
A3) Knee composed of a portion (a1) continuously twisted in the opposite direction to the rotation direction of the screw and a portion (a2) continuously twisted in the same direction as the rotation direction of the screw; Thickness of the loading segment (a1 thickness and a
2, the total thickness of the screw is 1.0 or more times the screw diameter,
A method for producing an olefin-based thermoplastic elastomer composition, comprising: disposing a kneading segment (A) having at least one position in a screw. 8. The kneading segment (A) has at least one location and the following features: B1) It has two apex portions (b) in a cross-sectional shape (where the apex portion is the most prominent from the center of gravity of the cross-section). B2) the top of the kneading segment in the thickness direction,
The manufacturing method according to claim 7, wherein a screw having at least one kneading segment (B) having a discontinuously twisted structure is used. 9. The production method according to claim 8, wherein a screw having a configuration in which the kneading segment (B) is arranged downstream of the kneading segment (A) without any other segment is used. 10. A combination of kneading segments (A) and (B) in which a kneading segment (B) is arranged without any other segment downstream of the kneading segment (A) is arranged in at least two places. The method according to claim 9, wherein the screw is used. 11. The method according to claim 7, wherein the clearance between the top of the kneading segment (A) and the inner wall of the cylinder of the extruder is 1/100 or more and 1/6 or less of the screw diameter. The manufacturing method as described. 12. A clearance between an apex portion of the kneading segment (B) (where the apex portion is a point or a portion farthest from the center of gravity of the cross section) and the inner wall of the cylinder of the extruder, and a screw diameter. The method according to any one of claims 8 to 10, wherein the value of the ratio is less than 1/60. 13. The temperature of at least one of the barrels on the upstream side of the twin-screw extruder is set to 170 ° C. or lower, and the temperature of at least one of the downstream barrels is set to 190 ° C. or higher.
3. The production method according to any one of 2. 14. The following equation: 4.5 <2.2 log X + log Y−log Z + (T−18)
0) ÷ 100 <6.0 (where T is the resin temperature (° C.) at the die outlet of the twin-screw extruder, and X is the screw diameter (m) of the twin-screw extruder.
m), Y is the maximum shear rate (sec ⁻¹ ) generated at the kneading segment (A) in the extruder, and Z is the output (kg / h) of the twin-screw extruder. The maximum shear rate Y (sec ^-1 ) is Y = (X × π × S) /
It is obtained from the equation of U. Here, X is the screw diameter (mm) of the twin-screw extruder, S is the screw rotation speed per second (rps), and U is the distance of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw ( mm). The method according to any one of claims 1 to 13, wherein the composition is dynamically crosslinked under the condition of (1). 15. When the olefin-based thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber is dynamically cross-linked by using a twin-screw extruder to produce the same, the extrusion rate Z of the twin-screw extruder in a steady state. (Kg / h) and the diameter X (mm) of the screw of the twin-screw extruder dynamically crosslink under a condition satisfying the following formula: Z / X ^2.3 ≧ 0.01, and 1 in a steady state.
A method for producing an olefin-based thermoplastic elastomer composition, comprising obtaining an olefin-based thermoplastic elastomer composition in which the average number of fish eyes of at least three or more samples sampled every time is 10 or less.