JPH07165931A - Production of thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To produce a thermoplastic elastomer composition having excellent flexibility, mechanical properties, etc., low oil-bleeding tendency and excellent extrusion moldability, etc. CONSTITUTION:This process for the production of a thermoplastic elastomer composition is characterized by the direct supply of (A) a particulate oil- extended olefinic copolymer rubber containing 20-150 pts.wt. of a mineral oil softening agent based on 100 pts.wt. of an olefinic copolymer rubber having a 100 deg.C Mooney viscosity (ML1+4 100 deg.C) of 180-350 and (B) an olefinic plastic to a single screw extruder and the dynamic crosslinking of the rubber in the presence of an organic peroxide under a condition satisfying the formulas, 0.5<=alpha<=50 and 1.0>=beta>=0.003alpha+0.12 [wherein alpha is the size (g/100 particles) of the particulate oil-extended olefinic copolymer rubber A and beta is specific energy (KW.hr/kg) of the extruder].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a thermoplastic elastomer composition. More specifically, the present invention relates to a method for producing an olefin-based thermoplastic elastomer composition which has excellent mechanical properties and can substitute for vulcanized rubber.

[0002]

2. Description of the Related Art Thermoplastic elastomer (hereinafter referred to as "TP
"E". ) Does not require a vulcanization process and can be processed with a normal thermoplastic resin molding machine, and its applications have been developed in a wide range of fields including automobile parts, home electric appliances parts and sundries. There is. Of these, olefin-based TPE compositions are known from JP-A-58-26838. However, this composition is inferior to the vulcanized rubber in terms of flexibility, tensile strength at break, elongation at break, compression set, etc. in the field of vulcanized rubber replacement, and thus has limited applications.

In order to improve these properties, a softening agent such as a mineral oil type softener and a non-crosslinking peroxidic hydrocarbon type rubber-like material are added to impart flexibility, and a crosslinking aid is used in combination to increase the degree of crosslinking and to achieve compression set. Various attempts have been made to improve the distortion.
(For example, JP-B-56-15740 and JP-A-58)
No. 25340, JP-A-58-152023, JP-A-59-58043). However, in these compositions, even if the degree of cross-linking is increased to improve the compression set, therefore, the flexibility decreases and the breaking strength and breaking elongation in the tensile test decrease, or the bleeding of the softening agent to the composition surface occurs. It has been difficult to obtain an olefinic TPE composition having a good balance of physical properties.

[0004]

SUMMARY OF THE INVENTION Under such circumstances, the problems to be solved by the present invention include vulcanization of an olefinic TPE composition in terms of flexibility and mechanical properties (particularly tensile breaking strength, breaking elongation, compression set). It is an object of the present invention to provide a method for producing an olefin-based TPE composition which can substitute for rubber and has good blow moldability, extrusion moldability, injection moldability and the like.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to overcome the drawbacks of the above-mentioned conventional methods, and as a result, using a specific particulate oil-extended olefin-based copolymer rubber and olefin-based plastic, The inventors have found that a composition obtained by dynamically cross-linking these by a specific method is excellent in appearance and the like with less bleeding, and is excellent in flexibility, mechanical properties and the like, and has completed the present invention.

That is, according to the present invention, the Mooney viscosity (M
L _{1 + 4} 100 ° C.) is 180 to 350, and mineral oil softener is added to 100 parts by weight of olefinic copolymer rubber 100 parts by weight.
Particulate oil-extended olefin-based copolymer rubber (A) and olefin-based plastic (B) containing 150 parts by weight
The present invention relates to a method for producing a thermoplastic elastomer composition, which is characterized in that it is directly supplied to a shaft extruder and is dynamically crosslinked in the presence of an organic peroxide under the condition that the following expression 2 is satisfied.

[0007]

## EQU2 ## 0.5 ≦ α ≦ 50 1.0 ≧ β ≧ 0.003 α + 0.12 α: Size of the particulate oil-extended olefin copolymer rubber (A). (G / 100) β: Specific energy of extruder. (KW ・ hr / kg)

Further, the present invention relates to a method for producing the above-mentioned thermoplastic elastomer composition, characterized in that dynamic crosslinking is carried out at a maximum shear rate of 500 / sec or more.
The present invention will be specifically described below.

The olefin copolymer rubber (A) constituting the particulate oil-extended olefin copolymer rubber used in the present invention is, for example, ethylene-propylene copolymer rubber or ethylene-propylene-non-conjugated rubber. It is an amorphous random elastic copolymer containing olefin as a main component, such as diene copolymer rubber, ethylene-butene-1-non-conjugated diene copolymer rubber, and propylene-butene-1 copolymer rubber. . Of these, ethylene-propylene-non-conjugated diene copolymer rubber (hereinafter referred to as "EPDM") is particularly preferable. Examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene and the like, and ethylidene norbornene is particularly preferable.

As a more specific example, the propylene content is 10 to 55% by weight, preferably 20 to 40% by weight,
Ethylene-propylene-ethylidene norbornene copolymer rubbers having an ethylidene norbornene content of 1 to 30% by weight, preferably 3 to 20% by weight are preferred. If the propylene content is less than 10% by weight, the flexibility is lost and 55
If it exceeds 5% by weight, mechanical properties are deteriorated, which is not preferable.
When the content of ethylidene norbornene is less than 1%, mechanical properties are deteriorated, and when it is more than 30% by weight, injection moldability is deteriorated, which is not preferable.

In the present invention, the 100 ° C. Mooney viscosity (ML 1 _{+ 4} 100 ° C.) of the olefinic copolymer rubber is 18
It is 0 to 350, preferably 200 to 300. 100
When the ℃ Mooney viscosity (ML _{1 + 4} 100 ℃) is lower than 180, the mechanical properties are deteriorated, and when it is higher than 350, the appearance of the molded article is deteriorated, which is not preferable.

In the present invention, the oil-extended olefin copolymer rubber is 20 to 150 parts by weight, preferably 3 parts by weight, of a mineral oil softener per 100 parts by weight of the olefin copolymer rubber.
It contains 0 to 120 parts by weight. If the amount is less than 20 parts by weight, the fluidity of the olefin-based TPE composition decreases,
In particular, extrusion processability and injection moldability are impaired, which is not preferable. On the other hand, if the amount is more than 150 parts by weight, the plasticity is remarkably increased and the workability is lowered, and further, the performance such as physical properties of the product is lowered, which is not preferable. Then, the Mooney viscosity (ML _{1 +} 41) of the oil-extended olefin-based copolymer rubber at 100 ° C.
00 ° C.) is preferably 30 to 150, more preferably 40 to 100. When it is lower than 30, mechanical properties are lost, and when it is higher than 150, moldability becomes difficult, which is not preferable.

The mineral oil-based softening agent used in the oil-extended olefin-based copolymer rubber is a high-boiling petroleum fraction that is blended for the purpose of improving processability and mechanical properties. Although there are system-based or aromatic-based systems, paraffin-based systems are preferably used. When the amount of aromatic components is large, the staining property becomes strong and the use for transparent products or light-colored products is limited, which is not preferable.

Next, the properties of an oil-extended olefin copolymer rubber (oil-extended EPDM) and a method for producing the same will be described by taking EPDM as an example. ML _{1 + 4 When a} large amount of a mineral oil-based softener is blended using EPDM having a temperature of 180 to 350 at 100 ° C,
It is possible to obtain an olefin-based TPE composition capable of satisfying both improvement of processability by securing flexibility and improvement of fluidity and improvement of mechanical properties at the same time. Generally, a mineral oil-based softening agent is used as a fluidity improver in an olefin-based TPE composition.
When oil-extended EPDM is not used, if 40 parts by weight or more of a mineral oil-based softening agent is added per 100 parts by weight of EPDM,
Bleed of the softening agent is generated on the surface of the TPE composition, and the product is contaminated and sticky, which is not preferable. But for example ML
_{1 + 4} 100 ° C. 180-350 EPDM 100 to 200 parts by weight of EPDM pre-blended with 20 to 150 parts by weight of a mineral oil-based softener, the oil-extended EPDM causes less bleeding of the softener, resulting in less product contamination and sticking. TPE with excellent physical properties such as breaking strength, breaking elongation, compression set, etc.
A composition can be obtained. Despite the large blending ratio of this mineral oil-based softening agent, the bleeding of the softening agent is not observed. When EPDM having a relatively high Mooney viscosity is used, the upper limit of the allowable oil extension of the mineral oil-based softening agent is It is considered that the temperature rises and that the softener added in advance is uniformly dispersed in the EPDM.

A known method is used as the oil-extending method of EPDM. For example, using a device such as a roll or a Banbury mixer, a method of oil-extending by a method of mechanically kneading EPDM and a mineral oil-based softening agent, or adding a predetermined amount of a mineral oil-based softening agent to an EPDM solution, and then , A method of removing the solvent by a method such as steam stripping, and the like.
Of these, the preferred oil extension method is a method using an EPDM solution, and the EPDM solution is an EPDM obtained by polymerization.
The operation is easier when using a solution.

In the present invention, the method for obtaining the (A) particulate oil-extended olefin copolymer rubber from the oil-extended olefin copolymer rubber is as follows. 1. Grinding of bale rubber. (1) A method of crushing with a commonly used crusher for rubber. (2) A method of pulverizing at low temperature using a high speed mill or a jet pulverizer. 2. A method of granulating using an extruder or the like. 3. A method in which a sheet is formed using rolls, and this is granulated with a pelletizer or the like. 4. A method in which the crumb-like polymer obtained by removing the solvent after the polymerization is used as it is. Of these, 1 and 4 are the preferred methods. Here, the particle of the particulate rubber means an irregular particle,
Not only spherical and columnar shapes, but also rectangular parallelepiped shapes, flake shapes, crumb shapes, lint shapes, and the like are included, as well as foamed particles and the like having a void inside. That is, the form does not matter as long as it can be identified as individual particles. Further, the particulate rubber has an inorganic filler for the purpose of preventing mutual adhesion,
It is possible to use a powder such as an olefin plastic, an organic lubricant, an inorganic lubricant, etc., and a liquid substance such as silicone oil, adhered to the surface in a small amount, or kneaded into rubber for use.

In the present invention, the size (α, g / 100) of the (A) particulate oil-extended olefin copolymer rubber is
As will be described later, it is important for the physical property balance of the thermoplastic elastomer composition to be obtained, and 0.5 ≦ α ≦ 50 g / 1
00, preferably 1 ≦ α ≦ 40 g / 100.

The olefinic plastic (B) used in the present invention is polypropylene or a copolymer of propylene and an α-olefin having 2 or more carbon atoms. Specific examples of the α-olefin having 2 or more carbon atoms include ethylene, 1-butene, 1-pentene, and 3-methyl-.
1-butene, 1-hexene, 1-decene, 3-methyl-
1-Pentene, 4-methyl-1-pentene, 1-octene and the like. The melt flow rate of these polymers is 0.
It is preferably 1 to 100 g / 10 minutes, more preferably 0.
It is in the range of 5 to 50 g / 10 minutes. If the melt flow rate is smaller than 0.1 g / 10 minutes or larger than 100 g / 10 minutes, there may be a problem in workability.

In the present invention, the compounding weight ratio of (A) the particulate oil-extended olefin copolymer rubber and (B) the olefin plastic is (A) / (B) = 20 to 95/8.
It is preferably 0-5. More preferably (A) /
(B) = 35-90 / 65-10, more preferably,
(A) / (B) = 35-85 / 65-15.

In the present invention, the above α is the above component (A).
And (B) are indexes that greatly affect the step of directly supplying the extruder to the extruder and performing melt-kneading. Especially ML _{1 + 4} 100 ℃
When an olefin-based copolymer rubber having a large value is used, it has a great influence on the dispersibility and morphology of the composition comprising the copolymer rubber and the olefin-based plastic. The dispersibility and the like of the composition formed here significantly affect the physical properties and processability of the TPE composition obtained through the subsequent dynamic crosslinking step. In the present invention, α is 0.5 to 50 g
However, if α is smaller than 0.1, the transport efficiency will be poor in the solid transport part of the continuous kneading extruder, and there is a risk of blockage in some cases. In addition, the mixing and kneading properties in the kneading section of the kneading machine are deteriorated, and it is difficult to form a preferable morphology in the TPE composition obtained. α is preferably 1 to 40 g / 100.
On the other hand, the size of the (B) olefin-based plastic particles does not have to be the same as the size (α) of the (A) particulate oil-extended olefin-based copolymer rubber, but it is generally about 1
It is preferably within the range of 10 to 100 g.

As the organic peroxide for dynamically cross-linking the mixture of (A) the particulate oil-extended olefin-based copolymer rubber and (B) the olefin-based plastic, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexane,
2,5-Dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) 3 , 5,5-trimethylcyclohexane,
2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, dicumyl peroxide and the like. Of these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is particularly preferable in terms of odor and scorch. The amount of the organic peroxide added is 0.005 to 2.50 per 100 parts by weight of the total of (A) the particulate oil-extended olefin-based copolymer rubber and (B) the olefin-based plastic.
It can be selected in the range of 0 parts by weight, preferably 0.01 to 0.6 parts by weight. If it is less than 0.005 parts by weight, the effect of the crosslinking reaction is small, and if it exceeds 2.0 parts by weight, it is difficult to control the reaction and it is not economically advantageous.

In producing the composition of the present invention, N, N'-m- serves as a cross-linking aid during dynamic cross-linking with an organic peroxide.
Peroxide crosslinking aids such as phenylene bismaleimide, toluylene bismaleimide, p-quinone dioxime, nitrobenzene, diphenylguanidine, trimethylolpropane, or divinylbenzene, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate. It is possible to coexist with a polyfunctional vinyl monomer such as allyl methacrylate. By blending such a compound, a uniform and mild crosslinking reaction and a reaction occur between the olefin-based copolymer rubber and the olefin-based plastic, and it is possible to improve the mechanical properties. The addition amount of the crosslinking aid is 100 in total of (A) the particulate oil-extended olefin-based copolymer rubber and (B) the olefin-based plastic.
It can be selected in the range of 0.01 to 4.0 parts by weight with respect to parts by weight. It is preferably 0.05 to 2.0 parts by weight. If it is less than 0.01 part by weight, the effect is difficult to appear, and if it exceeds 4 parts by weight, it is not economically advantageous.

A specific method for producing a TPE composition by dynamically crosslinking a mixture of (A) the particulate oil-extended olefin-based copolymer rubber and (B) the olefin-based plastic will be described below. First, the particulate olefin-based copolymer rubber (A) and the olefin-based plastic (B) are directly supplied and mixed in a specific ratio to a single-screw extruder, and melt-kneaded.
Next, an organic peroxide is preferably supplied from a supply port provided on the downstream side of the extruder to perform dynamic crosslinking, whereby the desired TPE composition is obtained.

In the production of the TPE composition according to the present invention, the particulate oil-extended olefin copolymer rubber (A), the olefin plastic (B) and the organic peroxide are fed to a single-screw extruder, The dynamic heat treatment is performed under the condition that satisfies the expression 3.

[0025]

0.5 ≦ α ≦ 50 1.0 ≧ β ≧ 0.003 α + 0.12 α: Size of particulate oil-extended olefin-based copolymer rubber (A)
It is. (G / 100) β: Specific energy of extruder. (KW · hr / kg) Here, the specific energy is the dynamic heat treatment.
Driving power of extruder (HP ₁: KW) to the same screw speed
Driving motion when driving empty (without feed material)
Power (HP₂: KW) was subtracted by the extrusion rate (Qkg / hr)
Is defined as a value and therefore its unit is KW · hr / kg
It This specific energy changes the operating conditions of the extruder.
It can be adjusted by That is, increase in screw rotation speed
In addition, increase of screen pack mesh,
Increase the amount of specific energy due to a decrease in salary.
You can It also varies depending on the screw shape.
And use a screw with a shallow groove depth.
And the specific energy increases.

In the present invention, the specific energy (β) is equal to or more than the value (0.003α + 0.12) represented by the equation 3 defined by the particle size (α) of the copolymer rubber. It is essentially important that it must be large, and if it is less than this, only a partially crosslinked rubber-resin composition having poor dispersion and poor physical properties can be obtained. However, the specific energy (β) is 1.0 kW · hr / kg
It is desirable that the temperature does not exceed, and under the conditions that exceed this, the temperature locally increases due to the conversion of mechanical energy into friction energy, which tends to cause deterioration of the object to be processed and physical properties, Moreover, the provision of such excess energy is unnecessary and not economical.

As the single-screw extruder which gives such specific energy, a single-screw continuous kneading extruder equipped with a screw or rotor having a kneading-improving function, or the material in the extruder is in a molten state It is possible to use a combination of extruders connected so as to be movable by. Examples of the screw design having the function of improving the kneading property include dullage, pins, and multi-dimensional flights.
Examples of the commercially available type of the uniaxial continuous kneading extruder include Busconieder (Buss) and HM type (Mitsubishi Heavy Industries).

In the present invention, the dynamic heat treatment using a single-screw extruder is generally carried out at a temperature at which a material, particularly an olefinic plastic, is melted, generally at 150 to 280 ° C., preferably at 200 to 250 ° C. Is carried out under conditions of a residence time of about 15 to 240 seconds, preferably about 30 to 180 seconds.

In the present invention, the maximum shearing rate at the time of dynamic crosslinking is preferably 500 / sec or more, but this can only be achieved by using the above continuous kneading extruder, and it can be achieved by conventional Banbury or roll. It is difficult to obtain with a batch type mixer. When the shear rate is less than 500 / sec, it is difficult to obtain a TPE composition having low production efficiency and excellent appearance and physical properties.

Next, specific steps of the preferred manufacturing method will be described. In the melt-kneading step of the particulate olefin-based copolymer rubber (A) and the olefin-based plastic (B), first, the components (A) and (B) are fed to the extruder by a belt type screw or a screw. Type feeder can be used,
A screw type pushing operation can also be used. Ingredient (A) /
The blending weight ratio of (B) is such that (A) / (B) is 20 to 95 /
80 to 5 is preferable, and when the content of (B) is less than that, physical properties are likely to be deteriorated during dynamic crosslinking, and shear heat generation tends to be large. In order to form a good morphology of the composition comprising the components (A) and (B), it is desirable that the kneading section has a screw or rotor having a design having a kneading property improving function.

Next, in the dynamic crosslinking step, the organic peroxide can be used by diluting it with a liquid or powdery substance. Supply from the supply port provided in the middle of the extruder
In the case of a liquid, it can be carried out by appropriately injecting it into the supply port with a metering pump or into a cylinder, and in the case of a powder, supplying it to the supply port with a metering feeder. As the diluent, oil, organic solvent, inorganic filler (silica,
Talc etc.) can be used. It is desirable that the dynamic cross-linking portion has a design having a function of improving kneading properties, such as dulmage, pins, and polymorphic flights. The maximum shear rate in the dynamically crosslinked portion is preferably 500 / sec or more. However, if it is too high, heat generation due to shearing tends to cause decomposition, deterioration, and coloration.

In the present invention, an olefinic plastic may be additionally added. The supply location can be upstream or downstream of the extruder. Moreover, it does not matter even after the dynamic crosslinking step. In the present invention, when a crosslinking aid is used, it is preferable to supply it before or at the same time as the supply of the organic peroxide. In the present invention, if necessary, an inorganic filler, an antioxidant, a weatherproofing agent, an antistatic agent, a lubricant, a coloring pigment, etc. may be added and used, but these may be fed from any part of the extruder.

As an alternative application of the vulcanized rubber of the olefinic TPE composition according to the present invention, a weather strip, a ceiling material, an interior sheet, a bumper molding, a side molding, an air spoiler, an air duct hose, various backings are used for automobile parts. Kind etc. For civil engineering materials and building materials, waterproofing materials, jointing materials, window frames for construction, etc. For sports equipment, grips for golf clubs and tennis rackets. Hose tubes, gaskets, etc. for industrial parts. For home electric appliances, there are hoses and backings. Hereinafter, the embodiments of the present invention will be specifically described by the present invention.

[0034]

EXAMPLES The contents of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The test methods used for measuring the physical properties in these examples and comparative examples are as follows.

(1) Mooney viscosity (ML _{1 + 4} 100 ° C.)
(Hereinafter referred to as "viscosity"): ASTM D-927-5
Compliant with 7T. The viscosity (ML ₁ ) of EPDM was calculated by Equation 4.

[0036]

## EQU00004 ## log (ML ₁ / ML ₂ ) = 0.066 (ΔPHR) ML ₁ : viscosity of EPDM. ML ₂ : Oil-extended EPDM viscosity. ΔPHR: Oil extension amount per 100 parts by weight of EPDM.

(2) Extrudability: USV type 25 mmφ extruder manufactured by Union Plastics. Full flight type screw, screw rotation speed 30 rpm. The T-die was used, and the judgment was performed on the extruded skin. The judgment ranks are as follows. ○: excellent △: good ×: bad

(3) Oil bleeding property: 7
Let stand for 1 hour in an oven at 0 ° C and visually observe the oil bleeding on the surface of the molded product. The judgment rank is as follows. ○: No bleeding. Δ: There is slight bleeding. ×: There is bleeding.

The production conditions for the uniaxial continuous kneading extruder are shown below. Equipment used: Tanabe Plastics Machine VS65-28
(L / D = 28 cylinder block number = 5) The configuration of the cylinder depends on the outer 1. That is, C1 to C
It has 5 cylinder blocks of 5, and the first supply port is C
1, a vent port is provided at C4, and a second supply port for supplying organic peroxide or the like is provided at C3 at the outside 1.
D is the die exit. In addition, C1 → C5 in Outer 1
To the downstream side of the extruder.

[0040]

[Outer 1]

Example 1 EPDM (ethylene-propylene-ethylidene norbornene copolymer rubber, viscosity = 242, propylene = 28% by weight, iodine value = 12) in a 4% by weight hexane solution,
100 parts by weight of a mineral oil-based softening agent (Diana Process Oil PW380 manufactured by Idemitsu Kosan Co., Ltd.) was added per 100 parts by weight of EPDM, and then the oil-extended EPDM (viscosity = 53) desolvated by steam stripping was crushed with a crusher to obtain a size. A particulate oil-extended olefin-based copolymer rubber (oil-extended EPDM) having (α) of 4.5 g / 100 was obtained. Next, 87 parts by weight of this oil-extended EPDM, MFR (230 ° C., 2.16 kg
Load) 10, 13 parts by weight of crystalline polypropylene (PP) having a size of 1.9 g / 100 pieces, and 1.1 parts by weight of N, N-metaphenylene bismaleimide (BM) are super mixers (manufactured by Kawata Manufacturing Co., Ltd.). And mixed for 30 seconds. This mixture was mixed into a single-screw continuous kneading extruder having a cylinder configuration shown in the outside 1 (VS65-2 manufactured by Tanabe Plastics Machinery).
8, L / D = 28, cylinder set temperature 180-200
℃, the die set temperature of 230 ℃) 1st supply port (C of outside 1)
It is melt-kneaded by supplying it from 1) at 30 kg / hr, and then from the second supply port (C3 of the outside 1), 2,5-dithymer-
2,5-di (tert-butylperoxy) hexane (hereinafter referred to as "organic peroxide") diluted to 50% by weight with a mineral oil-based oil (Idemitsu Kosan's paraffin-based oil Diana Process Oil PW90) (PO-1)
Was supplied at a rate of 480 g / hr to give a specific energy (β) of 0.15 KW · hr / kg for dynamic crosslinking and pelletization, and the physical properties and extrusion moldability were evaluated. The maximum shear rate of the dynamically crosslinked part was about 1600 / sec. Table 1 shows the evaluation results.
Shown in.

Comparative Example 1 In Example 1, 87 parts by weight of oil-extended EPDM was added to JSR.
43.5 parts by weight of EP-24 (ML 1 _{+ 4} 100 ° C. = 70, propylene content = 44% by weight, EPDM of iodine value = 12, manufactured by Japan Synthetic Rubber Co., Ltd.) and a mineral oil softener 43.
The same procedure as in Example 1 was carried out except that the amount was changed to 5 parts by weight. The evaluation results are shown in Table 1.

[0043]

[Table 1]

[0044]

According to the present invention, mechanical properties such as tensile strength, elongation at break, and compression set in the low hardness region of olefin-based TPE are improved, and further, workability and bleeding of oil onto the surface of a molded product are achieved. It is possible to provide a method for producing an olefin-based TPE composition which has an improved property and can substitute for a vulcanized rubber.

Claims (8)

[Claims] 1. A Mooney viscosity at 100 ° C. (ML _{1 + 4} 100
Particulate oil-extended olefin-based copolymer rubber (A) and olefin-based plastic (B) containing 20 to 150 parts by weight of a mineral oil-based softening agent per 100 parts by weight of an olefin-based copolymer rubber having a temperature of 180 to 350. ) Is directly supplied to a single-screw extruder, and dynamic crosslinking is carried out in the presence of an organic peroxide under the condition of satisfying the following formula 1, a method for producing a thermoplastic elastomer composition. ## EQU1 ## 0.5 ≦ α ≦ 50 1.0 ≧ β ≧ 0.003 α + 0.12 α: Size of the particulate oil-extended olefin copolymer rubber (A). (G / 100) β: Specific energy of extruder. (KW ・ hr / kg) 2. A 100 ° C. Mooney viscosity (ML 1 _{+ 4} 100 ° C.) of the (A) particulate oil-extended olefin copolymer rubber is 30.
The manufacturing method according to claim 1, wherein 3. The method according to claim 1, wherein the mineral oil softener is a paraffin softener. 4. The compounding weight ratio of (A) the particulate oil-extended olefin-based copolymer rubber and (B) the olefin-based plastic is (A) / (B) = 20-95 / 80-5. 1. The manufacturing method according to 1. 5. The (A) olefin-based copolymer rubber constituting the particulate oil-extended olefin-based copolymer rubber is ethylene-based rubber.
A propylene-non-conjugated diene copolymer rubber.
The manufacturing method described. 6. An ethylene-propylene-non-conjugated diene copolymer rubber is an ethylene-propylene-ethylidene norbornene copolymer rubber having a propylene content of 10 to 55% by weight and an ethylidene norbornene content of 1 to 30% by weight. The manufacturing method according to claim 5. 7. The production method according to claim 1, wherein the olefin-based plastic (B) is at least one selected from polypropylene and propylene-α-olefin copolymer resin. 8. The production method according to claim 1, wherein the dynamic crosslinking is performed at a maximum shear rate of 500 / sec or more.