JP2000327718A - Olefinic thermoplastic elastomer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an olefinic thermoplastic elastomer which can simply be produced in one process at a low cost without using a cross-linking agent, has excellent rubber elasticity, and can easily be recycled. SOLUTION: This olefinic thermoplastic elastomer comprises (A) 5 to 60 wt.% of polyethylene resin and (B) 40 to 95 wt.% of an ethylene.α-olefinic copolymer, and has the following characteristics (1) to (3): (1): 9<=Y-0.43X<=27 [X is the JIS A hardness of the elastomer, measured according to JIS K6301; Y is the compression permanent strain (%) of the elastomer, measured according to JIS K6301 under conditions of 70 deg.C×22 hr]; (2) a tensile strength of 5 to 30 MPa measured according to JIS K6301; and (3) a permanent elongation of <=17% measured according to JIS K6301.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an olefin-based thermoplastic elastomer, a thermoplastic elastomer composition for producing the same, and a method for producing the same. More specifically, the present invention relates to an olefin-based thermoplastic elastomer containing polyethylene resin and an ethylene / α-olefin-based copolymer and having excellent rubber elasticity, a composition, and a method for producing the same.

[0002]

2. Description of the Related Art Various materials have been used for parts or parts requiring rubber elasticity used in automobile parts, industrial machine parts, electric / electronic parts, building materials and the like. Such materials include, for example, vulcanized rubber. Normally, vulcanized rubber is prepared by kneading the rubber with a crosslinking agent, a crosslinking aid, additives and auxiliary materials to prepare an unvulcanized rubber compound,
Since it is manufactured through a vulcanization step of heating and vulcanizing, there is a problem that the steps are complicated and costly. Further, the vulcanized rubber is a thermosetting rubber and cannot be recycled.

On the other hand, a vinyl chloride resin is a material which does not require a vulcanizing step and has a performance similar to that of rubber. However, it is a major problem that vinyl chloride resin generates toxic gas when incinerated. Further, the rubber elasticity is inferior to vulcanized rubber, so that its use is limited.

A thermoplastic elastomer is known as a polymer material which is plasticized at a high temperature and can be molded in the same manner as a plastic, and has a rubber elasticity at a normal temperature. As an olefinic thermoplastic elastomer, a dynamically crosslinked product of polypropylene and an ethylene / α-olefin copolymer is known. However, also in this case, a dynamic cross-linking step is required, so that there is the same problem as above.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems by easily and inexpensively manufacturing in one step without using a crosslinking agent.
An object of the present invention is to provide an olefin-based thermoplastic elastomer which has excellent rubber elasticity and is easily recycled.
Another object of the present invention is to provide an olefin-based thermoplastic elastomer composition from which the above-mentioned olefin-based thermoplastic elastomer can be obtained by molding. Still another object of the present invention is to propose a method for producing an olefin-based thermoplastic elastomer composition that can efficiently produce the above-mentioned olefin-based thermoplastic elastomer composition. Still another object of the present invention is to provide
An object of the present invention is to propose a method for producing an olefin-based thermoplastic elastomer which can easily produce the above-mentioned easily recyclable olefin-based thermoplastic elastomer in a single step without using a crosslinking agent, and at a low cost. .

[0006]

SUMMARY OF THE INVENTION The present invention relates to the following olefinic thermoplastic elastomers, compositions and methods for producing them. (1) An olefin-based thermoplastic elastomer having the following characteristics. 9 ≦ Y−0.43X ≦ 27 (1) (in the formula (1), X is the JIS A hardness of the olefin resin-based thermoplastic elastomer measured in accordance with JIS K6301 (no unit), and Y is in accordance with JIS K6301. And
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours. ) Tensile strength measured according to JIS K6301 is 5
Permanent elongation measured according to JIS K6301 is 1
8% or less (2) An olefin-based thermoplastic elastomer containing a polyethylene resin (A) and an ethylene / α-olefin-based copolymer (B), the olefin-based thermoplastic elastomer having the above characteristics. (3) 5 to 60% by weight of a polyethylene resin (A), an ethylene / α-olefin-based copolymer (B) having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol% The olefin-based thermoplastic elastomer according to the above (2), which is obtained by dynamically heat-treating 40 to 95% by weight in the absence of a crosslinking agent. (4) Polyethylene resin (A) and ethylene / α-olefin copolymer (B) under the following conditions:
(2) or (3), which is obtained by dynamically heat-treating in the absence of a crosslinking agent with a twin-screw extruder. 4.8 <(T-130) / 100 + 2.2 logP + logQ-logR <7.0 ... (2) (In the formula (2), T is the resin temperature (° C) at the die outlet of the twin-screw extruder, and P is the twin-screw. Extruder screw diameter (m
m) and Q are the maximum shear rates (sec) received in the twin-screw extruder.
^-1 ), R is the throughput (kg / h) of the twin-screw extruder. The maximum shear rate Q (sec ^-1 ) is: Q = P × π × S / U
It is obtained from the formula. Here, P 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). (5) 5 to 60% by weight of a polyethylene resin (A), an ethylene / α-olefin copolymer having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol% ( B) An olefinic thermoplastic elastomer composition containing 40 to 95% by weight. (6) An ethylene / α-olefin copolymer (B) having a polyethylene resin (A) of 5 to 60% by weight, a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250, and an ethylene content of 70 to 95 mol%. An olefin-based thermoplastic elastomer composition obtained by dynamically heat-treating 40 to 95% by weight in the absence of a crosslinking agent. (7) The olefin-based thermoplastic elastomer composition according to the above (5) or (6), wherein the ethylene / α-olefin-based copolymer (B) is an ethylene / α-olefin / non-conjugated polyene copolymer. (8) Polyethylene resin (A) and ethylene α-
The olefin-based thermoplastic elastomer composition according to any one of the above (5) to (7), containing the polypropylene resin (C) in an amount of 30 parts by weight or less based on a total of 100 parts by weight of the olefin-based copolymer (B). (9) An ethylene / α-olefin copolymer (B) having a polyethylene resin (A) of 5 to 60% by weight, a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250, and an ethylene content of 70 to 95 mol%. A) a method for producing an olefin-based thermoplastic elastomer composition in which 40 to 95% by weight is dynamically heat-treated in the absence of a crosslinking agent; (10) Polyethylene resin (A), ethylene-α-
The thermoplastic elastomer composition containing the olefin-based copolymer (B) is dynamically heat-treated in the absence of a cross-linking agent to produce a thermoplastic elastomer having the above characteristics. A method for producing an elastomer. (11) 5 to 60% by weight of a polyethylene resin (A);
An ethylene / α-olefin copolymer (B) having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol% in the absence of a crosslinking agent And a method for producing a thermoplastic elastomer having the above-mentioned properties by molding a thermoplastic elastomer composition obtained by dynamically heat-treating the composition. (12) The production method according to the above (10) or (11), wherein the dynamic heat treatment is dynamically heat-treated by a twin-screw extruder under the conditions satisfying the above and in the absence of a crosslinking agent.

<< Polyethylene Resin (A) >> As the polyethylene resin (A) used in the present invention, known polyethylene resins such as high-density polyethylene, medium-density polyethylene, linear low-density polyethylene and low-density polyethylene are used without limitation. However, a linear low-density polyethylene is preferable, and a linear low-density polyethylene polymerized using a metallocene catalyst is particularly preferable.

The polyethylene resin (A) has a melt flow rate (MFR; ASTM D 1238, 190 ° C., 2.16 kg load) of 0.01 to 100 g / 10 minutes, preferably 0.01 to 5 g.
It is desirably 0 g / 10 minutes. MFR is 0.1
g / 10 minutes ultra high molecular weight polyethylene is 13
The intrinsic viscosity [η] measured in a 5 ° C decalin (decahydronaphthalene) solvent is usually 7 to 40 dl / g, and when such an ultrahigh molecular weight polyethylene is used as the polyethylene resin (A), the 135 ° C decalin An intrinsic viscosity [η] measured in a solvent of 15 to 40% by weight of a low to high molecular weight polyethylene having 0.1 to 5 dl / g;
It is preferably used in the form of an ultrahigh molecular weight polyethylene resin composition containing 85 to 60% by weight of ultrahigh molecular weight polyethylene having an intrinsic viscosity [η] of 7 to 40 dl / g. The intrinsic viscosity [η] is preferably from 3.5 to 8.3 dl / g. Polyethylene resin (A) has a density of 0.88 to 0.98 g / c
m ³ , preferably 0.90 to 0.95 g / cm ³ .

When a linear low-density polyethylene is used as the polyethylene resin (A), MFR (ASTM D 123)
8, 190 ° C, 2.16 kg load) 0.1 to 30 g / 10 min, preferably 0.2 to 20 g / 10 min, density 0.88 to
0.95 g / cm ³ , preferably 0.91 to 0.94 g
/ Cm ³ of linear low-density polyethylene is preferred.

[0010] When a linear low-density polyethylene is used as the polyethylene resin (A), skin roughness is less likely to occur and the appearance is excellent, and the surface has a sticky surface, as compared with a case where a high-density polyethylene or a medium-density polyethylene is used. It is possible to obtain molded products such as less extruded products and injection molded products.

The polyethylene resin (A) may be a homopolymer of ethylene, or a small amount of ethylene, for example, 1
It may be a copolymer with 0 mol% or less of another monomer. Other monomers include α-olefins having 3 to 20, preferably 3 to 8 carbon atoms; vinyl monomers such as vinyl acetate and ethyl acrylate. Examples of the α-olefin used as another monomer include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene. Other monomers can be used alone or in combination of two or more. The polyethylene resin (A) can be used alone or in combination of two or more.

<< Ethylene / α-olefin copolymer (B) >> As the ethylene / α-olefin copolymer (B) used in the present invention, known ethylene / α-olefin copolymers can be used. , Mooney viscosity ML _{1 + 4} (1
00 ° C) is from 90 to 250, preferably from 100 to 200,
More preferably, those having 110 to 180 are preferable. When the Mooney viscosity is in the above preferred range, the physical property balance as a thermoplastic elastomer is excellent, and an olefin-based thermoplastic elastomer with particularly excellent compression set is obtained, and when in the above more preferable range, the physical property balance is more excellent, In particular, an olefin-based thermoplastic elastomer having more excellent compression set can be obtained.

The ethylene / α-olefin copolymer (B) used in the present invention has an ethylene content of 70 to 95 mol%, preferably 70 to 90 mol%, more preferably 75 to 90 mol%, and particularly preferably. Is preferably a 75 to 85 mol% ethylene / α-olefin copolymer. When the ethylene content is in the above preferred range, an excellent balance of physical properties as a thermoplastic elastomer is obtained, and an olefin-based thermoplastic elastomer having particularly excellent compression set is obtained,
When it is in the above more preferable range, an olefin-based thermoplastic elastomer having more excellent balance of physical properties, particularly more excellent compression set can be obtained.

The ethylene / α-olefin copolymer (B) is composed of ethylene and C 3-20, preferably 3-8 carbon atoms.
And a copolymer other than the α-olefin may be copolymerized. Examples of the monomer other than the α-olefin include a non-conjugated polyene. In addition, ethylene
The α-olefin-based copolymer (B) may be a random copolymer or a block copolymer.

Specific examples of the ethylene / α-olefin copolymer (B) include ethylene / α-olefin copolymers and ethylene / α-olefin / non-conjugated polyene copolymers. Among them, ethylene / α-olefin / non-conjugated polyene copolymer is preferred.

In the ethylene / α-olefin copolymer (B), examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, pentene, 4-methyl-1-pentene, 1-hexene and 1
-Octene and the like. The α-olefin can be used alone or in combination of two or more.

In the ethylene / α-olefin copolymer (B), the non-conjugated polyene copolymerized with ethylene and α-olefin includes, for example, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene And non-conjugated dienes such as ethylidene norbornene. The non-conjugated polyene can be used alone or in combination of two or more. The iodine value of the ethylene / α-olefin / non-conjugated polyene copolymer is usually 0.1.
It is desirably 1 to 50, preferably 5 to 30.

The ethylene / α-olefin-based copolymer (B) can be used alone or in combination of two or more. Ethylene α-
The olefin copolymer (B) can be produced by a known method using a known catalyst such as a metallocene catalyst and a vanadium catalyst. For example, an ethylene / α-olefin / non-conjugated polyene copolymer can be produced by a method described in “Polymer Production Process (published by Industrial Research Institute, Ltd., pp. 309 to 330)”.

<< Olefin-based thermoplastic elastomer >> The olefin-based thermoplastic elastomer of the present invention comprises:
And an elastomer having the following characteristics.

9 ≦ Y−0.43X ≦ 27 (1) Preferably, 9 ≦ Y−0.43X ≦ 26 (1 ′) More preferably, 10 ≦ Y−0.43X ≦ 26 (1 ′) ') (In the formulas (1), (1') and (1 ''), X is JIS
JIS A hardness (no unit) of olefin resin thermoplastic elastomer measured according to K6301; Y is JI
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. ) Tensile strength measured according to JIS K6301 is 5
~ 30MPa, preferably 8 ~ 30MPa, more preferably 12 ~ 30MPa The permanent elongation measured in accordance with JIS K6301 is 1
8% or less, preferably 0.5 to 15%, more preferably 0.5 to 12%

The measuring method for the above characteristics is as follows. JIS A hardness: JIS K6301, instantaneous value by spring type hardness tester type A Compression set: JIS K6301, thickness 12.7 mm,
Using a cylindrical sample having a diameter of 29.0 mm, residual strain after compression at 25% and 70 ° C. for 22 hours. Tensile strength: Tensile strength obtained by performing a tensile test at a tensile speed of 200 mm / min using a JIS K6301 and JIS No. 3 dumbbell. Strength Permanent elongation: JIS K6301, JIS No. 3 dumbbell is stretched 100%, held for 10 minutes, and residual strain 10 minutes after load removal

The olefin-based thermoplastic elastomer of the present invention contains a polyethylene resin (A) and an ethylene / α-olefin-based copolymer (B), and has the above characteristics. Is preferred. As the ethylene / α-olefin-based copolymer (B), the ethylene / α-olefin-based copolymer (B) having Mooney viscosity and ethylene content within the above ranges is preferable. The content of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) is based on the sum of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B). A)
It is desirable that the amount is 5 to 60% by weight, preferably 10 to 50% by weight, and 40 to 95% by weight, preferably 50 to 90% by weight of the ethylene / α-olefin copolymer (B).

The olefin-based thermoplastic elastomer of the present invention is obtained by dynamically preparing an elastomer composition containing the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) in the absence of a crosslinking agent. It is preferably a thermoplastic elastomer obtained by heat treatment, and particularly preferably a thermoplastic elastomer obtained by dynamic heat treatment with a twin-screw extruder under the following conditions.

4.8 <(T-130) /100+2.2logP+logQ-logR <7.0 ... (2) Preferably, 5.0 <(T-130) /100+2.2logP+logQ-logR <6.8 ... (2 ') More preferably, 5.3 <(T-130) /100+2.2logP+logQ-logR <6.5 (2 ″) (in the above formulas (2), (2 ′) and (2 ″), T is Resin temperature (° C.) at the die outlet of the twin-screw extruder, P is the screw diameter (mm) of the twin-screw extruder, Q is the maximum shear rate (sec ⁻¹ ) received in the twin-screw extruder, and R is the twin-screw extruder. This is the extruder output (kg / h) and the maximum shear rate Q (se
c ^-1 ) is obtained from the equation of Q = P × π × S / U. Here, P is the diameter (mm) of the screw of the twin screw extruder, S
Is the number of rotations of the screw per second (rps), and U is the distance (mm) of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw. The olefin-based thermoplastic elastomer of the present invention obtained by dynamically heat-treating with a twin-screw extruder in the absence of a cross-linking agent under the conditions satisfying the above conditions provides tensile strength, permanent elongation, compression set, and molded appearance. Are better.

<< Olefin-Based Thermoplastic Elastomer Composition >> The olefin-based thermoplastic elastomer composition of the present invention, which is a raw material for producing the above-mentioned thermoplastic elastomer, comprises the polyethylene resin (A) and ethylene
5 to 60% by weight, preferably 10% by weight of polyethylene resin (A), based on the total amount of α-olefin copolymer (B)
To 50% by weight, ethylene / α-olefin-based copolymer (B) 40 to 95% by weight, preferably 50 to 90% by weight
It is a composition containing.

The olefin-based thermoplastic elastomer composition of the present invention comprises the polyethylene resin (A) and ethylene
5 to 60% by weight, preferably 10% by weight of polyethylene resin (A), based on the total amount of α-olefin copolymer (B)
To 50% by weight, ethylene / α-olefin-based copolymer (B) 40 to 95% by weight, preferably 50 to 90% by weight
Is preferably a composition obtained by dynamically heat-treating a mixture containing the following in the absence of a crosslinking agent.

The olefin-based thermoplastic elastomer and the elastomer composition of the present invention can be used as the thermoplastic elastomer when the contents of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) are within the above preferred ranges. It is possible to produce a thermoplastic elastomer having an excellent balance of physical properties, particularly excellent in compression set, and a thermoplastic elastomer having a more excellent balance of physical properties, particularly having a more excellent compression set when in the above more preferable range. can do.

The olefin thermoplastic elastomer and the elastomer composition of the present invention may contain a polypropylene resin (C). As the polypropylene resin (C), a known polypropylene resin can be used without limitation. Specific examples include the following polypropylene resins.

1) Propylene homopolymer 2) Random copolymer of propylene of 90 mol% or more and another α-olefin of 10 mol% or less (propylene
α-olefin random copolymer) 3) Block copolymer of propylene of 70 mol% or more and 30 mol% or less of other α-olefin (propylene
α-olefin block copolymer) Specific examples of the other α-olefin copolymerized with propylene include ethylene, 1-butene, and 4-methyl-.
Examples thereof include α-olefins having 2 to 20 carbon atoms, preferably 2 to 8 carbon atoms, such as 1-pentene, 1-hexene, and 1-octene.

As the polypropylene resin (C), the propylene homopolymer of 1) and the propylene
α-olefin random copolymer is preferred, especially MF
R (ASTM D 1238, 230 ° C, 2.16kg load) 0.1 ~ 50
g / 10 minutes is preferred. The polypropylene resin (C) can be used alone or in combination of two or more.

The content of the polypropylene resin (C) in the olefin-based thermoplastic elastomer and the elastomer composition of the present invention is 10 times in total of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B).
30 parts by weight or less, preferably 2 to 30 parts by weight with respect to 0 parts by weight
It is desirable that the amount be 5 parts by weight, more preferably 5 to 20 parts by weight. When the content of the polypropylene resin (C) is within the above range, it is possible to obtain molded products such as an extruded product and an injection molded product which are less likely to be roughened, have excellent appearance, and have less stickiness.

The olefin-based thermoplastic elastomer and the elastomer composition of the present invention may contain, if necessary, known softeners, heat stabilizers, anti-aging agents, and weather stabilizers as long as the objects of the present invention are not impaired. , Antistatic agent, filler,
Additives such as colorants and lubricants can be blended. As the softener, a mineral oil softener is preferably used. As such a mineral oil-based softener, a paraffin-based, naphthene-based, aromatic-based softener and the like usually used for rubber are suitable.

<< Production of Olefin-Based Thermoplastic Elastomer Composition >> The olefin-based thermoplastic elastomer composition of the present invention comprises the polyethylene resin (A) and the ethylene / α-olefin copolymer (B) or the polyethylene resin. (A), an ethylene / α-olefin-based copolymer (B) and a resin or an additive to be blended if necessary, and preferably by mixing at the above-mentioned specific ratio. They can also be prepared by dynamically heat treating these mixtures in the absence of a crosslinking agent.

<< Production of Olefin Thermoplastic Elastomer >> The olefin thermoplastic elastomer of the present invention is an elastomer composition containing the polyethylene resin (A) and the ethylene / α-olefin copolymer (B) or the polyethylene composition. An elastomer composition containing the resin (A), the ethylene / α-olefin-based copolymer (B) and a resin and an additive to be blended if necessary, preferably an elastomer composition containing the above-mentioned specific ratio, in the absence of a crosslinking agent. It can be manufactured by dynamically heat-treating below and shaping into a predetermined shape. When the elastomer composition is subjected to a dynamic heat treatment in the absence of a crosslinking agent,
The olefin-based thermoplastic elastomer of the present invention can be obtained only by molding the elastomer composition into a predetermined shape.

The above "dynamically heat-treating" means that the polyethylene resin (A), the ethylene / α-olefin copolymer (B), and the resins and additives to be blended if necessary are in a molten (melted) state. Means to knead. This dynamic heat treatment is preferably performed in the absence of an organic solvent such as a hydrocarbon solvent. However, the above softener may be present.

The dynamic heat treatment can be performed using a kneading device such as a mixing roll, an intensive mixer (eg, Banbury mixer, kneader), a single-screw extruder and a twin-screw extruder. It is preferably performed under conditions satisfying the above-mentioned formula (2). By dynamically heat-treating using a twin-screw extruder under the conditions satisfying the above formula (2), the components constituting the olefin-based thermoplastic elastomer are excellent in compatibility, tensile strength, permanent elongation, compression set, and An elastomer having excellent molded appearance can be produced. Dynamic heat treatment
It is preferably carried out in a non-open type kneading apparatus. Further, it is preferable to carry out in an inert gas such as nitrogen.

The conditions for the dynamic heat treatment are as follows: the kneading temperature is usually 150 to 280 ° C., preferably 170 to 240 ° C.
It is desirable that the kneading time is 1 to 20 minutes, preferably 1 to 5 minutes. Also, the shear force applied during kneading is
The shear rate is usually 10 to 10 ⁴ sec ⁻¹ , preferably 10 ²
It is desirable to set to 410 ⁴ sec ⁻¹ . In this way, by dynamically heat-treating in the absence of a crosslinking agent,
An olefin-based thermoplastic elastomer having the above characteristics can be obtained.

In the olefin-based thermoplastic elastomer of the present invention thus obtained, the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) form a lamellar structure. The length of one side of the lamella to be formed is preferably 2 μm or less, and more preferably 0.5 to 1.8 μm. When the length of one side of the lamella is within the above range, the polyethylene resin (A)
And the ethylene / α-olefin-based copolymer (B) have good compatibility and excellent tensile strength and compression set.

The olefin-based thermoplastic elastomer of the present invention has excellent rubber elasticity without being crosslinked (vulcanized) using a crosslinking agent or a crosslinking aid. Further, the olefin-based thermoplastic elastomer of the present invention is not a thermosetting elastic material such as a conventional vulcanized rubber, but a thermoplastic elastomer, so that it can be easily recycled. In addition, since a cross-linking agent or a solvent is not required, a kneading step of a cross-linking agent or the like and a step of desolvation are not required, and a dynamic heat treatment can be simply and efficiently obtained, thereby being inexpensive. Furthermore, since olefins are the main raw material and do not contain chlorine, no toxic gas is generated even when incinerated.

According to the production method of the present invention, the polyethylene resin can be used without using a crosslinking agent such as an organic peroxide or a vulcanization aid such as a divinyl compound which has been used in the production of a conventional vulcanized rubber. (A) and the ethylene / α-olefin-based copolymer (B), or the polyethylene resin (A), the ethylene / α-olefin-based copolymer (B), and resins and additives to be blended if necessary. By dynamically processing the olefinic thermoplastic elastomer having excellent rubber elasticity, it is possible to easily and efficiently produce the olefinic thermoplastic elastomer in one step. Further, since it is not necessary to use a crosslinking agent or a vulcanization aid, and a complicated vulcanization step is not required, it can be manufactured at low cost.

The thus obtained olefinic thermoplastic elastomer of the present invention can be suitably used in the fields of interior and exterior parts of automobiles, parts for home appliances, parts for civil engineering and construction materials, miscellaneous goods and daily necessities. it can.

[0042]

The olefin-based thermoplastic elastomer of the present invention has specific properties and is therefore excellent in rubber elasticity. Moreover, it can be easily performed in one process without using a crosslinking agent,
Moreover, it can be manufactured at low cost and is easy to recycle.

The olefin-based thermoplastic elastomer composition of the present invention is prepared by subjecting a specific amount of a polyethylene resin (A) and a specific ethylene / α-olefin-based copolymer (B) to a specific amount in the absence of a crosslinking agent. By heat treatment, it is possible to produce easily and inexpensively in one step without using a crosslinking agent, and it is possible to easily produce a thermoplastic elastomer having excellent rubber elasticity and easy recycling. .

The method for producing an olefinic thermoplastic elastomer composition of the present invention comprises the steps of: providing a specific amount of a polyethylene resin (A) and a specific amount of a specific ethylene / α-olefin-based copolymer (B) with a crosslinking agent In the absence of a olefinic thermoplastic elastomer composition which is dynamically heat-treated because of its excellent rubber elasticity and easy to recycle, it can be easily processed in one step without using a crosslinking agent, and at a low cost. It can be manufactured efficiently.

The method for producing the olefin-based thermoplastic elastomer of the present invention comprises the steps of:
The α-olefin-based copolymer (B) is dynamically heat-treated in the absence of a cross-linking agent to produce an elastomer having specific properties, so that the rubber has excellent rubber elasticity and is easy to recycle. An olefin-based thermoplastic elastomer can be easily produced in one step without using a crosslinking agent, and can be efficiently produced at low cost.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited to these examples. Raw materials such as polyethylene resin (A), ethylene / α-olefin-based copolymer (B) and polypropylene resin (C) used in the production of the olefin-based thermoplastic elastomer in Examples and Comparative Examples are described below. The melt flow rates (MFR) of these raw materials are ASTM D 1238, 190 unless otherwise specified.
It is a value measured under conditions of ° C and a load of 2.16 kg.

By measuring the intrinsic viscosity [η] of the copolymer in decalin at 135 ° C., the equation (3) gη ^* = [η] / [η] blank (3) (in the equation (3)) , [Η] is the intrinsic viscosity of the ethylene / α-olefin copolymer (B), and [η] blank is [η]
Ethylene / α-olefin copolymer (B)
Is the intrinsic viscosity of a linear ethylene / propylene random copolymer having the same weight average molecular weight (by the light scattering method) and an ethylene content of 70 mol% as measured in decalin at 135 ° C. Gη ^* value [Tokuhei 3
No. 14045 (JP-A-58-191705)]
I asked. The copolymer having a gη ^* value of more than 0.95 is linear, and the copolymer having a value of 0.2 to 0.95 can be said to be long-chain branched.

Equation (4) B = P _OE / (2P _O · P _E ) (4) (where P _E and P _O are ethylene · α, respectively)
-The mole fraction of the ethylene component and the mole fraction of the α-olefin component contained in the olefin-based copolymer (B), and P _OE is the ratio of ethylene / α-olefin to the total number of dyad chains. It is the ratio of the number of alternate chains. ) Was determined by the ¹³ C-NMR method. The B value is a parameter indicating the randomness of the copolymer monomer chain distribution, and is an index indicating the composition distribution state of the structural unit in the copolymer chain.

The P _E , P _O, and P _OE values were specifically calculated as follows. That is, 10 mm
ethylene · alpha-olefin copolymer to about 200mg in a test tube of φ a (B) was uniformly dissolved in hexachlorobutadiene 1ml to prepare a sample, ¹³ C-N of the sample
The MR spectrum is measured under the following conditions. << Measurement condition >> Measurement temperature: 120 ° C. Measurement frequency: 20.05 MHz Spectral width: 1500 Hz Filter width: 1500 Hz Pulse repetition time: 4.2 sec Pulse width: 7 μsec Integration frequency: 2000 to 5000 times

The values of P _E , P _O and P _OE were determined by GJ Ray from the ¹³ C-NMR spectrum measured as described above.
(Macromolecules, 10, 773 (1977)), JC Randall
(Macro-molecules, 15, 353 (1982)), K. Kimura (Po
lymer, 25, 4418 (1984)). Note that the B value obtained from the above equation (4) is
When both monomers are alternately distributed in the ethylene / α-olefin-based copolymer (B), the value is 2; in the case of a complete block copolymer in which both monomers are completely separated and polymerized, 0. Becomes

The glass transition temperature (Tg) was determined by DSC (differential scanning calorimeter). The D value was calculated from the ¹³ C-NMR spectrum of the ethylene / α-olefin copolymer (B). The D value is the intensity (area) ratio of Tαβ to Tαα in the ¹³ C-NMR spectrum of the ethylene / α-olefin copolymer (B), that is, Tαβ / Tαα.
It is. The D value varies depending on the type of the α-olefin constituting the ethylene / α-olefin copolymer (B). Tαβ and Tα in ¹³ C-NMR spectrum
α is the peak intensity of CH ₂ of the structural unit derived from α-olefin, and means two kinds of CH ₂ having different positions with respect to the tertiary carbon as shown in the following formula.

[0052]

Embedded image (Wherein, R is a residue of an α-olefin.)

The D value of the ethylene / α-olefin copolymer (B) was specifically determined as follows. That is, the ethylene / α-olefin-based copolymer (B)
^{The 13} C-NMR spectrum was measured by JEOL
Using an L-GX270 NMR measuring apparatus, a sample concentration of 5
% By weight of hexachlorobutadiene / d ₆ -benzene = 2
/ 1 (volume ratio) mixed solution at 67.8 MHz, 25 ° C
Was measured on the basis of d ₆ -benzene (128 ppm).
The analysis of the ¹³ C-NMR spectrum is basically based on the proposal of Lindemann Adams (Analysis Chemistry 43, p1245 (197
1)), JC Randall (Review Macromolecular Chemist
ry Physics. C29, 201 (1989)).

Here, the D value will be specifically described by taking ethylene / 1-butene / 7-methyl-1,6-octadiene copolymer rubber as an example. Ethylene 1-butene 7
¹³ C- of -methyl-1,6-octadiene copolymer rubber
In the NMR spectrum, the peak appearing at 39 to 40 ppm is assigned to Tαα, and the peak appearing at 31 to 32 ppm is assigned to Tαβ. The D value is calculated from the integrated value (area) ratio of each peak portion. The D value determined in this way is generally a ratio at which the 1,1 addition reaction of 1-butene is followed by a 2,1 addition reaction, or the 1,2-butene 2,2 addition reaction.
It is considered to be a scale indicating the rate at which 1,2 addition reactions occur after 1-addition reaction. Therefore, as the D value increases, α-
The bonding direction of the olefin (1-butene) is irregular,
Conversely, a smaller D value indicates that the α-olefin bond direction is more regular. When the D value is small and the regularity is high, the molecular chains are easily aggregated, and the copolymer tends to have excellent strength and the like, which is preferable. The ethylene / α-olefin copolymer (B) having a D value of 0.5 or less can be easily obtained by polymerization using a Group 4 metallocene catalyst such as titanium or zirconium. When a Group 5 metallocene catalyst is used, it is difficult to obtain an ethylene / α-olefin-based copolymer (B) having a D value of 0.5 or less. The same applies to α-olefins other than 1-butene.

<< Polyethylene Resin (A) >> (A-1) High-density polyethylene: 1) Density; 0.954 g / cm ³ 2) MFR; 0.8 g / 10 min 3) Ethylene homopolymer (A-2) Linear low density polyethylene: 1) Density; 0.920 g / cm ³ 2) MFR; 2.1 g / 10 min 3) Ethylene content; 97.0 mol%, 4-methyl-1-
Penten content: 3.0 mol% (A-3) Linear low-density polyethylene: 1) density; 0.920 g / cm ³ 2) MFR; 18 g / 10 min 3) ethylene content: 96.8 mol%, 4 -Methyl-1-
Penten content: 3.2 mol% (A-4) Low density polyethylene: 1) Density: 0.927 g / cm ³ 2) MFR: 3 g / 10 min 3) Ethylene homopolymer (A-5) Linear low Density polyethylene: 1) density; 0.915 g / cm ³ 2) MFR; 2 g / 10 min 3) ethylene content; 97.0 mol%, 4-methyl-1-
Penten content: 3.0 mol% 4) Linear low-density polyethylene polymerized using a metallocene catalyst (A-6) Low-density polyethylene: 1) Density; 0.915 g / cm ³ 2) MFR; 2.3 g / 10 min 3) Ethylene content; 95.8 mol%, 1-butene content;
4.2 mol% 4) Low density polyethylene polymerized using metallocene catalyst

<< Ethylene / α-olefin Copolymer (B) >> (B-1) Ethylene / propylene / dicyclopentadiene copolymer rubber: 1) Ethylene content: 77 mol% 2) Mooney viscosity [ML _{1 +4} , 100 ° C]; 145 3) Iodine value; 12 (B-2) Ethylene propylene / 5-ethylidene-2
-Norbornene copolymer rubber: 1) Ethylene content; 78 mol% 2) Mooney viscosity [ML1 _{+ 4} , 100 ° C]; 150 3) Iodine value; 13 (B-3) Ethylene propylene / 5-ethylidene- 2
-Norbornene copolymer rubber: 1) Ethylene content; 78 mol% 2) Mooney viscosity [ML1 _{+ 4} , 100 ° C]; 110 3) Iodine value; 13 (B-4) Ethylene propylene / 5-ethylidene- 2
-Norbornene copolymer rubber: 1) Ethylene content; 85 mol% 2) Mooney viscosity [ML _{1 + 4} , 100 ° C]; 150 3) Iodine value;

(B-5) Ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber: 1) Ethylene content; 82 mol% 2) Mooney viscosity [ML _{1 + 4} , 100 ° C.]; 153) Iodine value; 10 (B-6) ethylene-propylene / 5-ethylidene-2
-Norbornene copolymer rubber: 1) Ethylene content; 68 mol% 2) Mooney viscosity [ML1 _{+ 4} , 100 ° C]; 69 3) Iodine value; 13 (B-7) Ethylene propylene / 5-ethylidene- 2
-Norbornene copolymer rubber: 1) Ethylene content; 68 mol% 2) Mooney viscosity [ML _{1 + 4} , 100 ° C]; 100 3) Iodine value; 12 (B-8) Ethylene / 1-butene / 5- Ethylidene-2
-Norbornene copolymer rubber: 1) Ethylene content; 79 mol% 2) Mooney viscosity [ML _{1 + 4} , 100 ° C.]; 100 3) Iodine value; 10 4) Linear type polymerized using metallocene catalyst Ethylene / 1-butene / ENB copolymer rubber 5) gη ^* ; 0.98 6) B value; 1.1 7) Glass transition temperature (Tg); -56 ° C 8) D value; <0.01 (B -9) Ethylene / 1-butene-5-ethylidene-2
-Norbornene copolymer rubber: 1) Ethylene content; 79 mol% 2) Mooney viscosity [ML _{1 + 4} , 100 ° C.]; 95 3) Iodine value; 134 4) Long chain branch polymerized using metallocene catalyst Type ethylene / 1-butene / ENB copolymer rubber 5) gη ^* ; 0.67 6) B value; 1.1 7) Glass transition temperature (Tg); −56 ° C. 8) D value; B-10) The ethylene / propylene / (B-1)
40 parts by weight of dicyclopentadiene copolymer rubber
Parts by weight of extender oil (paraffin oil: Idemitsu Kosan Co., Ltd.)
Manufactured by PW-380 (trademark)

<< Polypropylene resin (C) >> (C-1) Propylene-ethylene random copolymer 1) Ethylene content; 4 mol% 2) MFR (ASTM D 1238, 230 ° C, 2.16 kg load);
5 g / 10 min (C-2) Propylene homopolymer 2) MFR (ASTM D 1238, 230 ° C, 2.16 kg load);
5 g / 10 min (C-3) Propylene homopolymer 1) Density; 0.91 g / cm^Three  2) MFR (ASTM D 1238, 230 ° C, 2.16 kg load);
4 g / 10 min << Mineral oil-based softener >> Paraffin-based oil: PW-38, manufactured by Idemitsu Kosan Co., Ltd.
0, trademark

Examples 1 to 18 The components were mixed at the ratios shown in Tables 1 to 3 using a Henschel mixer. Next, L / D = 30, screw diameter 5
Using a twin screw extruder of 0 mm, in a nitrogen atmosphere, 220 ° C.
And heat-extruded to produce pellets of the olefin-based thermoplastic elastomer composition. Next, a thermoplastic elastomer molded product as a sample for measuring physical properties is injection-molded from the pellets of the olefin-based thermoplastic elastomer composition using an injection molding machine, and has a hardness (JIS).
A), compression set (CS), and tensile strength were measured.
Further, permanent elongation was measured using this sample.
The results are shown in Tables 1 to 3.

Comparative Examples 1 to 7 The same procedures as in Examples were carried out except that the components shown in Table 4 or Table 5 were used in the proportions shown in Table 4 or Table 5. The results are shown in Tables 4 and 5.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

[0065]

[Table 5]

Notes in Tables 1 to 5 * 1 Hardness (JIS A): JIS K6301, instantaneous value using a spring type hardness tester A type * 2 Compression set: JIS K6301, thickness 12.7
mm, 29.0 mm in diameter using a cylindrical sample, 2
5% compression, residual strain after 70 ° C. × 22 hours * 3 Tensile strength: JIS K6301, a tensile strength obtained by performing a tensile test using a JIS No. 3 dumbbell at a tensile speed of 200 mm / min * 4 Permanent elongation: JIS K6301, JIS3 No. 10 dumbbell is stretched 100% and held for 10 minutes to remove the load 10
Residual strain after 5 minutes * 5 Roughness: A tape-shaped molded product was obtained at 210 ° C. by using an extruder having a screw diameter of 50 mm using pellets of the olefin-based thermoplastic elastomer composition. The surface roughness of this molded product was visually judged according to the following evaluation criteria. ：: No rough skin is observed ○: The rough skin is hardly noticeable △: The rough skin is not noticeable ×: The rough skin is considerably noticeable JIS A hardness (unit: none) of the thermoplastic elastomer, which is the value of * 1. Y: Compression set (unit: in units of compression set) of the olefin-based thermoplastic elastomer measured at 70 ° C. for 22 hours in accordance with JIS K6301. %), Which is the value of * 2. * 7 to * 11: (T-130) /100+2.2logP+logQ-logR (2) T: Resin temperature at die exit of twin screw extruder (° C.) P: Screw diameter of twin screw extruder (mm) Q: Maximum shear rate (sec ^-1 ) obtained from the above equation, received in the screw extruder R: Extrusion amount (kg / h) of the twin screw extruder

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BB03W BB05X GL00 GM00 GN00 GQ00 4J100 AA02P AA03Q AA04Q AA16Q AA17Q AA19Q CA01 CA04 DA09 JA28 JA43 JA67

Claims (12)

[Claims] An olefin-based thermoplastic elastomer having the following characteristics: 9 ≦ Y−0.43X ≦ 27 (1) (in the formula (1), X is the JIS A hardness of the olefin-based thermoplastic elastomer measured in accordance with JIS K6301 (unit is no unit), and Y is in accordance with JIS K6301. And
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours. ) Tensile strength measured according to JIS K6301 is 5
Permanent elongation measured according to JIS K6301 is 1
8% or less 2. A polyethylene resin (A), comprising:
An olefin-based thermoplastic elastomer containing an α-olefin-based copolymer (B), wherein the olefin-based thermoplastic elastomer has the following characteristics. 9 ≦ Y−0.43X ≦ 27 (1) (in the formula (1), X is the JIS A hardness of the olefin-based thermoplastic elastomer measured in accordance with JIS K6301 (unit is no unit), and Y is in accordance with JIS K6301. And
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours. ) Tensile strength measured according to JIS K6301 is 5
Permanent elongation measured according to JIS K6301 is 1
8% or less 3. A polyethylene resin (A) of 5 to 60% by weight.
And Mooney viscosity ML _{1 + 4} (100 ° C) is 90-25
0, ethylene-α- having an ethylene content of 70 to 95 mol%
The olefin-based thermoplastic elastomer according to claim 2, which is obtained by dynamically heat-treating the olefin-based copolymer (B) with 40 to 95% by weight in the absence of a crosslinking agent. 4. A heat treatment of a polyethylene resin (A) and an ethylene / α-olefin-based copolymer (B) dynamically by a twin-screw extruder in the absence of a crosslinking agent under the following conditions: The olefin-based thermoplastic elastomer according to claim 2, which is obtained by the following method. 4.8 <(T-130) / 100 + 2.2 logP + logQ-logR <7.0 ... (2) (In the formula (2), T is the resin temperature (° C) at the die outlet of the twin-screw extruder, and P is the twin-screw. Extruder screw diameter (m
m) and Q are the maximum shear rates (sec) received in the twin-screw extruder.
^-1 ), R is the throughput (kg / h) of the twin-screw extruder. The maximum shear rate Q (sec ^-1 ) is: Q = P × π × S / U
It is obtained from the formula. Here, P 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). ) 5. 5 to 60% by weight of a polyethylene resin (A)
And an olefin-based thermoplastic containing Mooney viscosity ML _{1 + 4} (100 ° C.) of from 90 to 250 and an ethylene content of from 70 to 95 mol% of 40 to 95% by weight of an ethylene / α-olefin-based copolymer (B). Elastomer composition. 6. Polyethylene resin (A) 5 to 60% by weight
And an ethylene / α-olefin copolymer (B) having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol%, and 40 to 95% by weight of a crosslinking agent. An olefin-based thermoplastic elastomer composition obtained by dynamically heat-treating in the presence. 7. The olefinic thermoplastic elastomer composition according to claim 5, wherein the ethylene / α-olefin-based copolymer (B) is an ethylene / α-olefin / non-conjugated polyene copolymer. 8. The method according to claim 5, wherein the polypropylene resin (C) is contained in an amount of 30 parts by weight or less based on 100 parts by weight of the total of the polyethylene resin (A) and the ethylene / α-olefin copolymer (B). The olefin-based thermoplastic elastomer composition according to any one of the above. 9. Polyethylene resin (A) 5 to 60% by weight
And an ethylene / α-olefin copolymer (B) having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol%, and 40 to 95% by weight of a crosslinking agent. A method for producing an olefin-based thermoplastic elastomer composition which is dynamically heat-treated in the presence. 10. A thermoplastic elastomer composition containing a polyethylene resin (A) and an ethylene / α-olefin-based copolymer (B) is dynamically heat-treated in the absence of a crosslinking agent to obtain the following: And a method for producing an olefin-based thermoplastic elastomer having the characteristics described above. 9 ≦ Y−0.43X ≦ 27 (1) (in the formula (1), X is the JIS A hardness of the olefin-based thermoplastic elastomer measured in accordance with JIS K6301 (unit is no unit), and Y is in accordance with JIS K6301. And
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours. ) Tensile strength measured according to JIS K6301 is 5
Permanent elongation measured according to JIS K6301 is 1
8% or less 11. An ethylene / α-olefin copolymer having a polyethylene resin (A) content of 5 to 60% by weight, a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250 and an ethylene content of 70 to 95 mol%. (B) An olefin for forming a thermoplastic elastomer composition obtained by dynamically heat-treating 40 to 95% by weight in the absence of a crosslinking agent to produce a thermoplastic elastomer having the following characteristics: A method for producing a thermoplastic elastomer. 9 ≦ Y−0.43X ≦ 27 (1) (in the formula (1), X is the JIS A hardness of the olefin-based thermoplastic elastomer measured in accordance with JIS K6301 (unit is no unit), and Y is in accordance with JIS K6301. And
It is the compression set (unit:%) of the olefin-based thermoplastic elastomer measured under the conditions of 70 ° C. × 22 hours. ) Tensile strength measured according to JIS K6301 is 5
Permanent elongation measured according to JIS K6301 is 1
8% or less 12. The production method according to claim 10, wherein the dynamic heat treatment is carried out dynamically by a twin-screw extruder in the absence of a crosslinking agent under the following conditions. 4.8 <(T-130) / 100 + 2.2 logP + logQ-logR <7.0 ... (2) (In the formula (2), T is the resin temperature (° C) at the die outlet of the twin-screw extruder, and P is the twin-screw. Extruder screw diameter (m
m) and Q are the maximum shear rates (sec) received in the twin-screw extruder.
^-1 ), R is the throughput (kg / h) of the twin-screw extruder. The maximum shear rate Q (sec ^-1 ) is: Q = P × π × S / U
It is obtained from the formula. Here, P 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). )