JP2002088164A - Molded product of olefinic thermoplastic elastomer, method for producing the same and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded product of an olefinic thermoplastic elastomer excellent in balance between hardness and elasticity, readily recyclable and available at a low cost. SOLUTION: This molded product of the olefinic thermoplastic elastomer is produced by molding the molded product from the olefinic thermoplastic elastomer, reducing the surface temperature of the molded product to <=50 deg.C and then heat-treating the resultant molded product at >=60 deg.C temperature. Furthermore, the molded product of the olefinic thermoplastic elastomer has characteristics satisfying the formula (1) -5<=Y-0.43X<9 (1) [in the formula (1), X is the JISA hardness (no unit) of the molded product measured according to JIS K6301; Y is the compression set (unit: %) of the molded product measured under conditions of 70 deg.C×22 h according to JIS K6301].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article of an olefin-based thermoplastic elastomer (hereinafter sometimes simply referred to as a molded article), a method for producing the same, and a use thereof. More specifically, it is made of polyethylene resin, ethylene-α-olefin-based copolymer and, if necessary, olefin-based thermoplastic elastomer containing polypropylene resin, and is excellent in balance between hardness and rubber elasticity, easy to recycle, and low cost. The present invention relates to an obtained olefin-based thermoplastic elastomer molded product, a method for producing the same, and a use thereof.

[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 cost increases. 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, vinyl chloride resin is inferior in rubber elasticity as compared with vulcanized rubber, and thus 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 a recyclable olefin-based thermoplastic elastomer, a dynamically crosslinked product of polypropylene and an ethylene / α-olefin copolymer is known. However, also in this case, there is a problem that the cost is increased due to the necessity of a crosslinking agent and a crosslinking aid.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems by providing an olefin-based thermoplastic resin which has an excellent balance between hardness and rubber elasticity, is easy to recycle, and can be obtained at low cost. An object of the present invention is to provide an elastomer molded article, a production method thereof, and an application.

[0006]

The present invention relates to the following olefins:
-Based thermoplastic elastomer molded article, its production method and use
It is way. (1) Molded from olefinic thermoplastic elastomer
A molded product obtained by the following equation (1) -5 ≦ Y−0.43X <9 (1) (where X is measured in accordance with JIS K6301)
JIS hardness (no unit) of the molded product, Y is JIS
 Measured at 70 ° C for 22 hours according to K6301
It is the compression set (unit:%) of the molded article. Full)
Olefinic thermoplastic elastomer composition with added properties
Shape. (2) Molded from olefinic thermoplastic elastomer
(1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (in the formula (1 ′), X is measured in accordance with JIS K6301).
JISA hardness of the molded product (no unit), Y is JI
Measured at 70 ° C for 22 hours according to SK6301
It is the compression set (unit:%) of the specified molded product. )
Olefinic thermoplastic elastomer with satisfying properties
Molding. (3) When the olefin-based thermoplastic elastomer is
A polyethylene resin (A) having a content of 90 mol% or more;
Ethylene with an ethylene content of 70 mol% or more and less than 90 mol%
Containing α-olefin-based copolymer (B)
(1) or a thermoplastic thermoplastic elastomer
The molded article according to (2). (4) The content of the polyethylene resin (A) is 5 to 60 weights
% Of ethylene / α-olefin copolymer (B)
The molding according to the above (3), wherein the amount is 40 to 95% by weight.
Goods. (5) Polyethylene resin (A) is high density polyethylene
Polyethylene, medium density polyethylene, linear low density polyethylene
(3) or (4) above or a low density polyethylene
The molded article as described. (6) The ethylene / α-olefin copolymer (B) is
Mooney viscosity ML_{1 + 4}(100 ° C) 90-250 etch
Above (3) which is a len-α-olefin copolymer
(5) The molded article according to any of (5). (7) The olefin-based thermoplastic elastomer is
Tylene resin (A) and ethylene / α-olefin
With respect to a total of 100 parts by weight of the polymer (B),
The propylene resin (C) is contained in a ratio of 0.1 to 30 parts by weight.
(3) which is an olefinic thermoplastic elastomer
A molded article according to any one of (1) to (6). (8) The olefin-based thermoplastic elastomer is
Tylene resin (A), ethylene / α-olefin copolymer
Body (B) and optionally used polypropylene tree
Fat (C) is obtained by dynamically heat-treating in the absence of a crosslinking agent.
The above is an olefinic thermoplastic elastomer used
The molded article according to any one of (3) to (7). (9) After the surface temperature of the molded article has dropped to 50 ° C. or less,
The above (1) which has been heat-treated at a temperature of 60 ° C. or higher.
A molded article according to any one of (8) to (8). (10) The surface temperature of the molded product has dropped to 50 ° C or less.
Thereafter, heat treatment was performed at a temperature of 60 to 110 ° C. for 1 to 90 minutes.
The method according to any one of (1) to (8) above,
Molding. (11) After molding the molded product, the surface temperature of the molded product is 8
At a cooling rate of 10 ° C./hr or less during a period between 0 and 60 ° C.
Any of the above (1) to (8), which is slowly cooled
The molded article according to the above. (12) Polyethylene having an ethylene content of 90 mol% or more
Resin (A), ethylene content 70 mol% or more 90 mol
% Ethylene / α-olefin copolymer (B)
Molded from an olefinic thermoplastic elastomer containing
The surface temperature of the molded product is 50 ° C or less.
After lowering, heat-treated at a temperature of 60 ° C or higher
An olefin-based thermoplastic elastomer molded product. (13) Equation (1) −5 ≦ Y−0.43X <9 (1) (In the equation (1), X is measured according to JIS K6301.
JIS hardness (no unit) of the molded product, Y is JIS
 Measured at 70 ° C for 22 hours according to K6301
It is the compression set (unit:%) of the molded article. Full)
The molded article according to the above (12), which has an additional property. (14) Equation (1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (In the equation (1 ′), X is measured according to JIS K6301.
JISA hardness of the molded product (no unit), Y is JI
Measured at 70 ° C for 22 hours according to SK6301
It is the compression set (unit:%) of the specified molded product. )
The molded article according to the above (12), which has characteristics that satisfy the requirements. (1
5) Molded products from olefinic thermoplastic elastomer
After molding, the surface temperature of the molded product falls to 50 ° C or less,
And heat-treated in the formula (1) -5 ≦ Y−0.43X <9 (1) (in the formula (1), X is measured according to JIS K6301)
JIS hardness (no unit) of the molded product, Y is JIS
 Measured at 70 ° C for 22 hours according to K6301
It is the compression set (unit:%) of the molded article. Full)
Olefinic thermoplastic elastomer composition with added properties
Olefinic thermoplastic elastomer molding to produce shaped articles
Product manufacturing method. (16) Molded from olefinic thermoplastic elastomer
The product was molded and the surface temperature of the molded product dropped to 50 ° C or less.
Thereafter, heat treatment is performed at a temperature of 60 ° C. or more, and the formula (1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (in the formula (1 ′), X is measured according to JIS K6301).
JISA hardness of the molded product (no unit), Y is JI
Measured at 70 ° C for 22 hours according to SK6301
It is the compression set (unit:%) of the specified molded product. )
Olefinic thermoplastic elastomer with satisfying properties
Olefinic thermoplastic elastomers for molding
The method of manufacturing shaped articles. (17) Heat treatment at 60 to 110 ° C for 1 to 90 minutes
(15) or (16). (18) Molded from olefinic thermoplastic elastomer
After molding, the surface temperature of the molded
Is gradually cooled at a cooling rate of 10 ° C./hr or less,
(1) −5 ≦ Y−0.43X <9 (1) (In the formula (1), X is measured according to JIS K6301.
JIS hardness (no unit) of the molded product, Y is JIS
 Measured at 70 ° C for 22 hours according to K6301
It is the compression set (unit:%) of the molded article. Full)
Olefinic thermoplastic elastomer composition with added properties
Olefinic thermoplastic elastomer molding to produce shaped articles
Product manufacturing method. (19) Molded from olefinic thermoplastic elastomer
After molding, the surface temperature of the molded
Is gradually cooled at a cooling rate of 10 ° C./hr or less,
(1 ′) − 5 ≦ Y−0.43X <8.18 (1 ′) (In the formula (1 ′), X is measured according to JIS K6301.
JISA hardness of the molded product (no unit), Y is JI
Measured at 70 ° C for 22 hours according to SK6301
It is the compression set (unit:%) of the specified molded product. )
Olefinic thermoplastic elastomer with satisfying properties
Olefinic thermoplastic elastomers for molding
The method of manufacturing shaped articles. (20) The olefin-based thermoplastic elastomer is
Polyethylene resin (A) with a ren content of 90 mol% or more
And an ethylene content of 70 mol% or more and less than 90 mol%.
Oleide containing Tylene / α-olefin copolymer (B)
Above (15) which is a fin type thermoplastic elastomer
(19) The production method according to any of (19). (21) The content of the polyethylene resin (A) is 5 to 60.
% By weight of the ethylene / α-olefin copolymer (B)
The product according to the above (20), wherein the content is 40 to 95% by weight.
Construction method. (22) Polyethylene resin (A) is high density polyethylene
Polyethylene, medium density polyethylene, linear low density polyethylene
Or (2) or (2)
1) The production method according to the above. (23) Ethylene / α-olefin copolymer (B)
Is Mooney viscosity ML_{1+ Four}(100 ° C) 90-250 d
The above (20), which is a ethylene / α-olefin copolymer
To (22). (24) When the olefin-based thermoplastic elastomer is
Ethylene resin (A) and ethylene / α-olefin type
With respect to a total of 100 parts by weight of the copolymer (B),
0.1 to 30 parts by weight of propylene resin (C)
(2) which is an olefinic thermoplastic elastomer containing
The production method according to any one of 0) to (23). (25) When the olefin-based thermoplastic elastomer is
Ethylene resin (A), ethylene / α-olefin copolymer
Combination (B) and optionally used polypropylene
Resin (C) is dynamically heat-treated in the absence of a crosslinking agent
The obtained olefinic thermoplastic elastomer is
(20) The production method according to any one of (24) to (24). (26) Polyethylene having an ethylene content of 90 mol% or more
Resin (A), ethylene content 70 mol% or more 90 mol
% Ethylene / α-olefin copolymer (B)
Molded from olefin-based thermoplastic elastomer containing
Was molded, and the surface temperature of the molded article was reduced to 50 ° C. or less.
Olefin-based thermoplastics that are then heat treated at a temperature of 60 ° C or higher
Method for producing conductive elastomer molded article. (27) Equation (1) −5 ≦ Y−0.43X <9 (1) (In the equation (1), X is measured according to JIS K6301.
JIS hardness (no unit) of the molded product, Y is JIS
 Measured at 70 ° C for 22 hours according to K6301
It is the compression set (unit:%) of the molded article. Full)
Olefinic thermoplastic elastomer composition with added properties
The manufacturing method according to (26), wherein the shaped article is manufactured. (28) Expression (1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (In the expression (1 ′), X is measured according to JIS K6301.
JISA hardness of the molded product (no unit), Y is JI
Measured at 70 ° C for 22 hours according to SK6301
It is the compression set (unit:%) of the specified molded product. )
Olefinic thermoplastic elastomer with satisfying properties
The production method according to the above (26), wherein the molded article is produced. (29) According to any one of the above (1) to (14)
Interior or exterior parts of automobiles consisting of molded products of (30) Any of the above (1) to (14)
Home appliance parts consisting of molded products. (31) Any of the above (1) to (14)
Civil engineering or building material parts made of molded products.

The olefin-based thermoplastic elastomer used in the present invention is not particularly limited as long as it can obtain a molded product satisfying the characteristics of the above formula (1), preferably the formula (1 ′). Olefin-based thermoplastic elastomer containing ethylene / α-olefin-based copolymer (B) is preferable, and by using such an elastomer, a molded article satisfying the characteristics of the formula (1) can be easily produced at low cost. Can be manufactured.

<< Polyethylene Resin (A) >> The polyethylene resin (A) used in the present invention may be a homopolymer of ethylene, or 90 mol% or more, preferably 92 mol%.
A copolymer of the above ethylene and another monomer of 10 mol% or less, preferably 8 mol% or less may be used. Other monomers include those having 3 to 20 carbon atoms, preferably 3 to 20 carbon atoms.
Α-olefin No. 8; 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,
-Hexene and 1-octene. Other monomers can be used alone or in combination of two or more.

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. The polyethylene resin (A) can be produced by a known method using a known catalyst such as a metallocene catalyst and a vanadium catalyst.

The polyethylene resin (A) preferably used in the present invention is a linear low-density polyethylene, and particularly preferably a linear low-density polyethylene polymerized using a metallocene catalyst. When the linear low density polyethylene is used as the polyethylene resin (A), as compared with the case where the high density polyethylene or the medium density polyethylene is used, the roughening is less likely to occur and the appearance is excellent and the surface is less sticky. A molded product such as a product or an injection molded product can be obtained.

The polyethylene resin (A) has a melt flow rate (MFR; ASTM D 1238, 190 ° C.)
2.16 kg load) is 0.01 to 100 g / 10 min, preferably 0.01 to 50 g / 10 min. The ultrahigh molecular weight polyethylene having an MFR of less than 0.1 g / 10 min usually has an intrinsic viscosity [η] of 7 to 4 at 135 ° C. measured in a decalin (decahydronaphthalene) solvent.
0 dl / g. When such an ultra-high molecular weight polyethylene is used as the polyethylene resin (A), 13
The intrinsic viscosity [η] measured in a decalin solvent at 5 ° C is 0.1
Low molecular weight to high molecular weight polyethylene 1 to 5 dl / g
5 to 40% by weight and an intrinsic viscosity [η] of 7 to 40 dl / g
Is preferably used in the form of an ultrahigh molecular weight polyethylene resin composition containing 85 to 60% by weight of the ultrahigh molecular weight polyethylene, and the intrinsic viscosity [η] of the whole ultrahigh molecular weight polyethylene resin composition is 3.5 to 8 It is preferably 0.3 dl / g.

The polyethylene resin (A) has a density of 0.88
0 to 0.980 g / cm ³ , preferably 0.900 to 0.980 g / cm ³
0.960 g / cm ³ , more preferably 0.900 to
Desirably, it is 0.950 g / cm ³ . The polyethylene resin (A) can be used alone, or 2
More than one type can be used in combination.

<< Ethylene / α-olefin Copolymer (B) >> The ethylene / α-olefin copolymer (B) used in the present invention has an ethylene content of 70 mol% or more and less than 90 mol%, preferably 75 mol% or more and 90 mol%
Less, more preferably 75 to 85 mol% of a known ethylene / α-olefin copolymer can be used. When the ethylene content is in the above preferred range, an excellent balance of physical properties is obtained, and in particular, an olefin-based thermoplastic elastomer molded article having excellent compression set is obtained. An olefin-based thermoplastic elastomer molded article having more excellent permanent 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 copolymer (B) preferably has a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 250, preferably 100 to 200, more preferably 110 to 180. When the Mooney viscosity is in the above preferred range, the physical property balance is excellent,
In particular, an olefin-based thermoplastic elastomer molded article having an excellent compression set can be obtained, and when the olefin-based thermoplastic elastomer is in the above more preferable range, an olefin-based thermoplastic elastomer molded article having a more excellent balance of physical properties and particularly having a more excellent compression set can be obtained. .

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)”.

<< Polypropylene Resin (C) >> The olefin-based thermoplastic elastomer used in 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) A propylene homopolymer 2) A 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, 2.16 kg
(Load) of 0.1 to 50 g / 10 min is preferable. The polypropylene resin (C) can be used alone or in combination of two or more.

<< Olefin-Based Thermoplastic Elastomer >> The olefin-based thermoplastic elastomer used in the present invention contains the above-mentioned polyethylene resin (A), ethylene / α-olefin-based copolymer (B) and, if necessary, polypropylene resin (C). It is preferable that the content thereof is based on the total amount of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B).
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).
When an olefin-based thermoplastic elastomer having a content of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) within the above range is used, a molded article satisfying the above-mentioned formula (1) can be more easily formed. Can be manufactured at low cost. The content of the polypropylene resin (C) is the same as that of the polyethylene resin (A) and ethylene · α.
-0.1 to 30 parts by weight, preferably 2 to 30 parts by weight, based on a total of 100 parts by weight of the olefin copolymer (B);
More preferably, the ratio is 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.

[0024] The olefinic thermoplastic elastomer used in the present invention includes, as long as the object of the present invention is not impaired,
If necessary, known additives such as a softener, a heat-resistant stabilizer, an antioxidant, a weather-resistant stabilizer, an antistatic agent, a filler, a colorant, and a lubricant 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.
Further, such a mineral oil-based softener may be added when producing an olefin-based thermoplastic elastomer, or may be added in advance as an extender oil to the ethylene / α-olefin-based copolymer (B). Good.

The olefinic thermoplastic elastomer used in the present invention includes the polyethylene resin (A), ethylene
The α-olefin-based copolymer (B), and the polypropylene resin (C) to be blended if necessary, and other resins and additives are mixed in the above-described specific ratio, and the mixture is dynamically heat-treated in the absence of a crosslinking agent. Thus, those manufactured by the method are preferred.

The above-mentioned "dynamically heat-treating" means the above-mentioned polyethylene resin (A), ethylene / α-olefin copolymer (B), and optionally blended polypropylene resin (C), other resins and This refers to kneading the additive in a molten (melted) state. This dynamic heat treatment
The mixing can be performed using a kneading device such as a mixing roll, an intensive mixer (for example, a Banbury mixer or a kneader), a single screw extruder, or a twin screw extruder. Is
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 .

When the dynamic heat treatment is performed using a twin-screw extruder, the following formula (2), preferably formula (2 ′),
More preferably, the reaction is performed under the condition satisfying the expression (2 ″).

4.8 <(T-130) /100+2.2logP+logQ-logR <7.0 ... (2) 5.0 <(T-130) /100+2.2logP+logQ-logR <6.8 ... (2 ') 5.3 <(T-130) /100+2.2logP+logQ-logR <6.5 ... (2 '') (where T is the resin temperature (° C.) at the die exit of the twin screw extruder, and P is the twin screw extrusion Machine screw diameter (mm),
Q is the maximum shear rate (sec ^-1 ) received in the twin screw extruder,
R is the extrusion rate (kg / h) of the twin-screw extruder. The maximum shear rate Q (sec ^-1 ) is obtained from the equation Q = P × π × S / U. Here, P is the diameter (mm) of the screw of the twin-screw extruder, and S is the screw rotation speed per second (rpm).
s), U is the distance (mm) of the narrowest part of the clearance between the barrel inner wall and the kneading segment of the screw
It is. )

By dynamically heat-treating using a twin-screw extruder under the conditions satisfying the above condition (2), the components constituting the olefin-based thermoplastic elastomer are excellent in compatibility, excellent in tensile strength and excellent in molding appearance. Molded articles can be manufactured.

<< Olefin Thermoplastic Elastomer Molded Article >> The molded article of the present invention has the following formula (1), preferably formula (1 ′), more preferably formula (1 ″), and particularly preferably formula (1 ′). '') Molded product having characteristics that satisfy −5 ≦ Y−0.43X <9 (1) −5 ≦ Y−0.43X <8.18 (1 ′) −5 ≦ Y−0.43X ≦ 8.1 (1 ″) − 5 ≦ Y−0.43X ≦ 8 (1 ′ ″)

A molded product that satisfies the above formula (1) means that it has an excellent balance between hardness and rubber elasticity, and is suitable for applications in which compression and release and / or elongation and release are repeated. This property becomes more excellent as the expressions (1 ′), (1 ″), and (1 ″ ′) are satisfied.

X in the formula (1) is the JIS A hardness of the molded article measured in accordance with JIS K6301 (unit is no unit).
, Which is an instantaneous value obtained by a spring type hardness tester A type. Y is 70 ° C. × 2 according to JIS K6301.
It is the compression set (unit:%) of the molded article measured under the condition of 2 hours, and is a value of 25% compression.

The molded article of the present invention contains an olefin thermoplastic elastomer containing the polyethylene resin (A) and the ethylene / α-olefin copolymer (B), preferably containing the polyethylene resin (A). 5-6
0% by weight, ethylene / α-olefin copolymer (B)
A molded article formed from an olefinic thermoplastic elastomer having a content of 40 to 95% by weight, more preferably an olefinic thermoplastic elastomer obtained by dynamic heat treatment in the absence of a crosslinking agent, The molded article has been subjected to a heat treatment at a temperature of 60 ° C. or higher after the surface temperature of the molded article has dropped to 50 ° C. or lower. A molded article obtained by heat-treating such a specific olefin-based thermoplastic elastomer under specific conditions has an excellent balance between hardness and rubber elasticity, and usually satisfies the formulas (1) to (1 ′ ″).

[0034] The molded article of the present invention is excellent in rubber elasticity and excellent in balance between hardness and rubber elasticity, although it is made of an olefinic thermoplastic elastomer which does not use a crosslinking agent or a vulcanization aid. ing. Since there is no need to use a cross-linking agent or a vulcanization aid, and no complicated vulcanization step is required, it can be produced at low cost and can be recycled.

<< Method for Producing Olefin-Based Thermoplastic Elastomer Molded Article >> The olefin-based thermoplastic elastomer molded article of the present invention comprises an olefin-based thermoplastic elastomer, preferably the above-mentioned polyethylene resin (A) and ethylene.
α-olefin-based copolymer (B), and olefin-based thermoplastic elastomer containing polypropylene resin (C) optionally used, more preferably olefin produced by dynamically heat-treating in the absence of a crosslinking agent It is manufactured by molding a molded article from a thermoplastic elastomer and then cooling the molded article to a surface temperature of 50 ° C. or lower, preferably 40 ° C. or lower, more preferably room temperature, and heat-treating at a temperature of 60 ° C. or higher. be able to. The molding method at the time of molding is not particularly limited, and molding methods used for ordinary thermoplastic elastomers such as injection molding, extrusion molding, compression molding (press molding), and blow molding can be adopted. Various composite moldings such as two-color injection molding and multilayer extrusion molding with an olefin resin or an olefin elastomer are also possible.

The heat treatment can be performed, for example, in a thermostat such as a gear oven. Heat treatment condition is heat treatment temperature 6
0 ° C or more, preferably 60 to 110 ° C, more preferably 65 to 100 ° C, and the heat treatment time is 1 minute or more, preferably 1 to 90 minutes, more preferably 2 to 6 minutes.
0 minutes is desirable. The heat treatment is preferably performed on a molded article having the shape of the final molded article. By performing the heat treatment in this manner, a molded product satisfying the above formula (1) can be easily manufactured at low cost.

In the molded article of the present invention, after the molded article is molded from the olefin-based thermoplastic elastomer, the period in which the surface temperature of the molded article is 80 to 60 ° C. is 10 ° C./hr or less.
Preferably, it can also be produced by a method of gradually cooling at a cooling rate of 2 to 10 ° C / hr. By controlling the cooling time in this way, it is possible to easily produce a molded product satisfying the above formulas (1) to (1 ′ ″) at low cost.

[0038] The molded article of the present invention obtained in this way is made from an olefin-based thermoplastic elastomer which does not use a crosslinking agent or a vulcanization aid, etc.
Excellent rubber elasticity and excellent balance between hardness and rubber elasticity. Since there is no need to use a cross-linking agent or a vulcanization aid, and no complicated vulcanization step is required, it can be produced at low cost and can be recycled.

The molded article of the present invention has the above characteristics and can be repeatedly used for compression and release and / or extension and release, so that the interior and exterior parts of automobiles, parts for home appliances, and parts for civil engineering and civil engineering It can be suitably used in fields such as building material-related parts, miscellaneous goods and daily necessities.

[0040]

The olefin-based thermoplastic elastomer molded article of the present invention satisfies the above formula (1), so that it is excellent in the balance between hardness and rubber elasticity, easy to recycle, and can be obtained at low cost. In addition, the olefin-based thermoplastic elastomer molded article of the present invention is heat-treated under specific conditions after molding, or is obtained by cooling under specific conditions, so that it is excellent in balance between hardness and rubber elasticity and easy to recycle, Moreover, it can be obtained at low cost.

In the method for producing a molded article of an olefin-based thermoplastic elastomer of the present invention, the molded article is heat-treated under specific conditions or cooled under specific conditions after molding, so that the molded article can be easily produced at low cost.

Since the molded article of the present invention has an excellent balance between hardness and rubber elasticity, is easy to recycle, and can be obtained at low cost, it can be used for interior and exterior parts of automobiles, parts for home appliances, parts for civil engineering and construction materials. , Miscellaneous goods and daily necessities.

[0043]

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.

The raw materials such as polyethylene resin (A), ethylene / α-olefin 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 12 unless otherwise specified.
38, 190 ° C., 2.16 kg load. The abbreviations of each raw material correspond to the symbols in the table.

<< 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 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
- pentene content; 3.0 mole% · (A-3) low-density polyethylene: 1) ^{Density; 0.927g / cm 3 2) MFR} ; 3g / 10 min 3) ethylene homopolymer

<< 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 ・ (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; 0.5 g / 10 min (ASTM D123)
8, 230 ° C, 2.16 kg load) << Mineral oil-based softener >> Paraffin-based oil: PW-38, manufactured by Idemitsu Kosan Co., Ltd.
0, trademark

Examples 1 to 7 The components shown in Table 1 were mixed with a Henschel mixer. Next, L / D = 3
0, using a twin screw extruder with a screw diameter of 50 mm, dynamically heat-treated at 220 ° C. in a nitrogen atmosphere and extruded to produce pellets of an olefin-based thermoplastic elastomer.
Next, from the pellets of the olefin-based thermoplastic elastomer, using an injection molding machine, a thickness of 12.7 mm and a diameter of 2
A 9.0 mm cylindrical sample was injection molded. After the sample was cooled to room temperature, the hardness (JIS A) was measured. Further, after heat-treating this sample in an oven at 90 ° C. for 30 minutes, the compression set (JIS K6301) after 22 hours at 70 ° C. was measured. Table 1 shows the results.

Comparative Example 1 An ethylene / propylene / dicyclopentadiene copolymer rubber (B-1) and a propylene / ethylene random copolymer (C-1) were used in the proportions shown in Table 1 in the same manner as in Example. Thus, pellets of an olefin-based thermoplastic elastomer were obtained. A sample for measuring physical properties was prepared from the pellet in the same manner as in the example, and the hardness and compression set were measured. Table 1 shows the results.

Comparative Example 2 Using a sample obtained from the olefin-based thermoplastic elastomer pellets of Example 1, the compression set was measured without heat treatment in an oven. Table 1 shows the results.

[0051]

[Table 1]

Notes to Table 1 * 1 A-1: High density polyethylene * 2 A-2: Linear low density polyethylene * 3 A-3: Low density polyethylene * 4 B-1: Ethylene propylene dicyclopentadiene Copolymer rubber * 5 B-2: 70 parts by weight of the ethylene / propylene / dicyclopentadiene copolymer rubber of B-1 mixed with 40 parts by weight of an extending oil * 6 C-1: Propylene / ethylene Random copolymer * 7 Paraffin oil: PW, manufactured by Idemitsu Kosan Co., Ltd.
-380, Trademark * 8 T: Resin temperature at die outlet of twin screw extruder (° C) * 9 P: Diameter of screw of twin screw extruder (mm) * 10 Q: Received in twin screw extruder, Q = P × π × S /
Maximum shear rate (sec ^-1 ) determined from the formula of U * 11 R: Extrusion amount of twin screw extruder (kg / h) * 12 S: Screw rotation speed per second (rps) * 13 U: Barrel inner wall And the distance of the narrowest part of the clearance between the kneading segments of the screw (m
m) * 14 Value of equation (2): "(T-130) / 100 + 2.2logP + l
ogQ-logR "* 15 Hardness (JIS A): JIS K6301, instantaneous value using a spring type hardness tester type A * 16 Compression set: JIS K6301, 25% compression, residual strain after 70 ° C x 22 hours * 17 Y-0.43X: X is the hardness of * 15 above, Y is the compression set of * 16 above

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C08L 23/10 C08L 23/10 // B29K 21:00 B29K 21:00 23:00 23:00 F term ( Reference) 4F071 AA15 AA15X AA16 AA17 AA19 AA20 AA20X AF13Y AF20Y AF21Y AF25Y BB05 BB13 4F073 AA07 AA32 BA07 BA08 BA09 GA01 4F201 AA03 AA04E AA05 AA07 AA11 AA45 AB03 AH24 AH15 A26B26 ARH26 AB12

Claims (31)

[Claims] 1. A molded article formed from an olefin-based thermoplastic elastomer, wherein the formula (1) -5 ≦ Y−0.43X <9 (1) (wherein X is JIS K6301. JISA hardness (unit: none) of the molded product measured according to JIS, Y is JIS
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with K6301. An olefin-based thermoplastic elastomer molded product having characteristics satisfying (1). 2. A molded article molded from an olefin-based thermoplastic elastomer, wherein the formula (1 ′)-5 ≦ Y−0.43X <8.18 (1 ′) (1 ′) , X is the JISA hardness of the molded article measured in accordance with JIS K6301 (no unit), Y is JI
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. An olefin-based thermoplastic elastomer molded product having characteristics satisfying (1). 3. An olefin-based thermoplastic elastomer,
An olefin-based thermoplastic elastomer comprising a polyethylene resin (A) having an ethylene content of 90 mol% or more and an ethylene / α-olefin-based copolymer (B) having an ethylene content of 70 mol% or more and less than 90 mol%. Item 3. The molded article according to item 1 or 2. 4. The content of the polyethylene resin (A) is 5 to 5.
The molded article according to claim 3, wherein the content of the ethylene / α-olefin-based copolymer (B) is 40 to 95% by weight. 5. The molded article according to claim 3, wherein the polyethylene resin (A) is a high-density polyethylene, a medium-density polyethylene, a linear low-density polyethylene, or a low-density polyethylene. 6. An ethylene / α-olefin copolymer (B) having a Mooney viscosity ML _{1 + 4} (100 ° C.) of 90 to 25.
The molded article according to any one of claims 3 to 5, wherein the molded article is an ethylene / α-olefin copolymer of 0. 7. An olefin-based thermoplastic elastomer,
An olefin-based thermoplastic elastomer further containing 0.1 to 30 parts by weight of a polypropylene resin (C) based on a total of 100 parts by weight of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B) The molded article according to any one of claims 3 to 6, wherein 8. An olefin-based thermoplastic elastomer,
Olefin-based thermoplastic resin obtained by dynamically heat-treating polyethylene resin (A), ethylene / α-olefin-based copolymer (B) and optionally used polypropylene resin (C) in the absence of a crosslinking agent The molded article according to any one of claims 3 to 7, which is an elastomer. 9. The molded article according to claim 1, wherein the molded article has been subjected to a heat treatment at a temperature of 60 ° C. or higher after the surface temperature of the molded article has dropped to 50 ° C. or lower. 10. The molded article according to claim 1, wherein the molded article is heat-treated at a temperature of 60 to 110 ° C. for 1 to 90 minutes after the surface temperature of the molded article has dropped to 50 ° C. or lower. 11. The method according to claim 1, wherein after the molded article is molded, the period in which the surface temperature of the molded article is 80 to 60 ° C. is gradually cooled at a cooling rate of 10 ° C./hr or less. The molded article as described. 12. An olefin heat containing a polyethylene resin (A) having an ethylene content of 90 mol% or more and an ethylene / α-olefin copolymer (B) having an ethylene content of 70 mol% or more and less than 90 mol%. A molded article molded from a thermoplastic elastomer, wherein the surface temperature of the molded article is 5
An olefin-based thermoplastic elastomer molded article which has been subjected to a heat treatment at a temperature of 60 ° C. or higher after decreasing to 0 ° C. or lower. 13. Formula (1) −5 ≦ Y−0.43X <9 (1) (in the formula (1), X is the JISA hardness (unit: none) of the molded product measured according to JIS K6301) Y is JIS
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with K6301. 13. The molded article according to claim 12, which has a property satisfying (1). 14. Formula (1 ′)-5 ≦ Y−0.43X <8.18 (1 ′) (wherein X is the JISA hardness of a molded product measured in accordance with JIS K6301. (No unit), Y is JI
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. 13. The molded article according to claim 12, which has a property satisfying (1). 15. A molded article is molded from an olefin-based thermoplastic elastomer, and after the surface temperature of the molded article falls to 50 ° C. or lower, heat treatment is performed at a temperature of 60 ° C. or higher to obtain the formula (1) −5 ≦ Y-0. .43X <9 ... (1) (In the formula (1), X is the JISA hardness of the molded article measured in accordance with JIS K6301 (unit is none), and Y is JIS
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with K6301. A method for producing an olefin-based thermoplastic elastomer molded article for producing an olefin-based thermoplastic elastomer molded article having characteristics satisfying the above conditions. 16. A molded article is molded from an olefin-based thermoplastic elastomer, and after the surface temperature of the molded article falls to 50 ° C. or lower, heat treatment is performed at a temperature of 60 ° C. or higher to obtain the formula (1 ′)-5 ≦ Y− 0.43X <8.18 (1 ′) (in the formula (1 ′), X is the JISA hardness of the molded article measured according to JIS K6301 (unit is none), and Y is JI
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. A method for producing an olefin-based thermoplastic elastomer molded article for producing an olefin-based thermoplastic elastomer molded article having characteristics satisfying the above conditions. 17. The method according to claim 15, wherein the heat treatment is performed at a temperature of 60 to 110 ° C. for 1 to 90 minutes. 18. After a molded article is molded from an olefinic thermoplastic elastomer, the molded article has a surface temperature of 80 to 60.
At a cooling rate of 10 ° C./hr or less,
Formula (1) −5 ≦ Y−0.43X <9 (1) (in Formula (1), X is the JISA hardness of the molded article measured according to JIS K6301 (unit is none), and Y is JIS
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with K6301. A method for producing an olefin-based thermoplastic elastomer molded article for producing an olefin-based thermoplastic elastomer molded article having characteristics satisfying the above conditions. 19. After molding a molded article from the olefinic thermoplastic elastomer, the surface temperature of the molded article is 80 to 60.
At a cooling rate of 10 ° C./hr or less,
Formula (1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (In the formula (1 ′), X is the JISA hardness of the molded product measured in accordance with JIS K6301 (unit is none), Y is JI
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. A method for producing an olefin-based thermoplastic elastomer molded article for producing an olefin-based thermoplastic elastomer molded article having characteristics satisfying the above conditions. 20. An olefin thermoplastic elastomer comprising a polyethylene resin (A) having an ethylene content of 90 mol% or more and an ethylene / α-olefin copolymer (B) having an ethylene content of 70 mol% to less than 90 mol%. 15. An olefin-based thermoplastic elastomer comprising:
20. The production method according to any one of the above items. 21. The content of the polyethylene resin (A) is 5
The method according to claim 20, wherein the content of the ethylene / α-olefin-based copolymer (B) is 40 to 95% by weight. 22. The polyethylene resin (A) according to claim 20, wherein the polyethylene resin (A) is a high density polyethylene, a medium density polyethylene, a linear low density polyethylene or a low density polyethylene.
2. The production method according to 1. 23. An ethylene / α-olefin copolymer (B) having a Mooney viscosity of ML _{1 + 4} (100 ° C.) 90 to 25.
23. The method according to claim 20, wherein the ethylene / α-olefin-based copolymer is 0. 24. The olefin-based thermoplastic elastomer is based on 100 parts by weight of the total of the polyethylene resin (A) and the ethylene / α-olefin-based copolymer (B).
The method according to any one of claims 20 to 23, further comprising an olefin-based thermoplastic elastomer containing the polypropylene resin (C) in a ratio of 0.1 to 30 parts by weight. 25. An olefin-based thermoplastic elastomer is obtained by mixing a polyethylene resin (A), an ethylene / α-olefin-based copolymer (B) and optionally a polypropylene resin (C) in the absence of a crosslinking agent. 25. The production method according to claim 20, which is an olefin-based thermoplastic elastomer obtained by dynamically heat-treating. 26. An olefin heat containing a polyethylene resin (A) having an ethylene content of 90 mol% or more and an ethylene / α-olefin copolymer (B) having an ethylene content of 70 mol% or more and less than 90 mol%. A method for producing an olefin-based thermoplastic elastomer molded article, comprising molding a molded article from a thermoplastic elastomer, reducing the surface temperature of the molded article to 50 ° C. or lower, and then heat-treating the molded article at a temperature of 60 ° C. or higher. 27. Formula (1) −5 ≦ Y−0.43X <9 (1) (In Formula (1), X is the JISA hardness (unit: none) of the molded product measured according to JIS K6301) Y is JIS
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with K6301. 27. The production method according to claim 26, wherein an olefin-based thermoplastic elastomer molded article having the property satisfying the condition (2) is produced. 28. Formula (1 ′) −5 ≦ Y−0.43X <8.18 (1 ′) (In Formula (1 ′), X is the JISA hardness of a molded product measured according to JIS K6301.) (No unit), Y is JI
It is the compression set (unit:%) of a molded article measured under the conditions of 70 ° C. × 22 hours in accordance with SK6301. 27. The production method according to claim 26, wherein an olefin-based thermoplastic elastomer molded article having the property satisfying the condition (2) is produced. 29. An interior or exterior part of an automobile, comprising the molded article according to claim 1. Description: 30. An electric home appliance part comprising the molded article according to claim 1. Description: 31. A civil engineering or building material part comprising the molded article according to claim 1. Description: