JP3535640B2 - Thermoplastic elastomer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition. More specifically, it relates to a thermoplastic elastomer composition having excellent scratch resistance.

[0002]

2. Description of the Related Art Olefin polymer materials are widely used for automobile parts and the like as energy-saving and resource-saving type materials because they are lightweight and easy to recycle.
Further, in recent years, from the viewpoint of protecting the global environment, olefin polymer resin materials, which emit no harmful gas during incineration, have been widely used. However, conventional olefin polymer materials have the drawback of being inferior in scratch resistance compared to vinyl chloride resin, so when used for automobile parts etc., make sure that they are not scratched by spray painting or knife coater etc. Although a method of surface-treating has been used, there is a problem that the manufacturing process is complicated and costly, and therefore improvement has been desired.

[0003]

The object of the present invention is to make use of the advantages of the olefin polymer material such as light weight, easy recycle use, and generation of noxious gas even when incinerated, and scratch resistance. To provide an excellent thermoplastic elastomer.

[0004]

The above objects and advantages of the present invention are to provide a thermoplastic elastomer (A) containing a crystalline polyolefin resin (a) and a crosslinked olefin rubber (b) and a poly-1-butene resin ( B) and silicone oil (C), and the weight ratio of thermoplastic elastomer (A) and poly 1-butene (B) [(A) /
(B)] is and is in the range of 60 / 40-5 / 95 on SL
Silicone oil (C) as thermoplastic elastomer (A)
And a thermoplastic elastomer composition containing 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the poly-1-butene resin (B).

The present invention is described in detail below, with which other objects and advantages of the present invention will become apparent.

Thermoplastic Elastomer (A) [I] Crystalline Polyolefin Resin (a) The crystalline polyolefin resin (a) used in the present invention is a homopolymer or a copolymer of α-olefin having 2 to 20 carbon atoms. Polymers may be mentioned. Specific examples of the crystalline polyolefin resin (a) include the following polymers or copolymers. (1) Ethylene homopolymer (manufacturing method may be low pressure method, high pressure method, etc.) (2) Copolymerization of ethylene with 10 mol% or less of other α-olefin or vinyl monomer such as vinyl acetate or ethyl acrylate Polymer (3) Propylene homopolymer (4) Random copolymer of propylene and 10 mol% or less of other α-olefin (5) Block copolymerization of propylene and 30 mol% or less of other α-olefin Polymer (6) 1-Butene homopolymer (7) Random copolymer of 1-butene and 10 mol% or less of other α-olefin (8) 4-Methyl-1-pentene homopolymer (9) 4 -Random copolymer of methyl-1-pentene and 20% by mole or less of other α-olefins Other α-olefins as the above-mentioned comonomers include, for example, ethylene, 1-butene, 4-methyl-1-pentene. The
One or more kinds can be appropriately selected from 1-hexene, 1-octene and the like. In the above, the mol% of other α-olefin as a comonomer is based on all repeating units constituting the copolymer. Hereinafter, mol% of the olefin is based on all repeating units constituting the polymer similarly.

Among the above crystalline polyolefin resins (a), a crystalline polypropylene resin is preferable, and a propylene homopolymer, a random copolymer of propylene and 10 mol% or less of α-olefin, and a propylene content of 50.
A propylene / α-olefin block copolymer of not less than mol% is particularly preferable. The crystalline polyolefin resin (a) as described above can be used alone or in combination. Melt flow rate of crystalline polyolefin resin (a) (MFR; ASTM D1238, 230 ° C, 2.
16 kg load, the same below) is preferably 0.01 to 10
0 g / 10 minutes, more preferably 0.3 to 70 g / 10
It is in the range of minutes. The crystallinity of the crystalline polyolefin resin (a) determined by the X-ray method is usually 5-10.
It is in the range of 0%, preferably 20 to 80%.

In the thermoplastic elastomer (A), the crystalline polyolefin resin (a) is preferably 10 to 90 parts by weight per 100 parts by weight of the total amount of the crystalline polyolefin resin (a) and the crosslinked olefin rubber (b). Parts, more preferably 10 to 80 parts by weight, still more preferably 10 to 70 parts by weight. When the crystalline polyolefin resin (a) is used in the above proportion, the thermoplastic elastomer composition of the present invention has good moldability, and the molding obtained from the composition has excellent scratch resistance and heat resistance. .

[II] Crosslinked olefin rubber (b) The crosslinked olefin rubber (b) which is a component constituting the thermoplastic elastomer (A) has an α-olefin content of 2 to 20 carbon atoms of 50 mol% or more. It is a cross-linked product of α-olefin random copolymer rubber. Examples of the α-olefin random copolymer rubber include copolymer rubbers of two or more types of α-olefins and copolymer rubbers of two or more types of α-olefins and non-conjugated dienes. As the α-olefin random copolymer rubber, specifically, the following (1) to (4)
The rubber shown by can be illustrated. (1) Ethylene / α-olefin copolymer rubber [ethylene / α-olefin (molar ratio) = about 90/10 to 50 /
50] (2) Ethylene / α-olefin / non-conjugated diene copolymer rubber [ethylene / α-olefin (molar ratio) = about 90
/ 10 to 50/50] (3) Propylene / α-olefin copolymer rubber [propylene / α-olefin (molar ratio) = about 90/10 to 5
0/50] (4) 1-butene / α-olefin copolymer rubber [1-
Butene / α-olefin (molar ratio) = about 90/10 to 5
0/50]

Examples of the α-olefins (1) to (4) above include ethylene, propylene, 1-butene and 4-
One or more of methyl-1-pentene, 1-hexene, 1-octene and the like can be appropriately selected and used.

The non-conjugated diene preferably has 6 to 20 carbon atoms, and specific examples thereof include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene and ethylidene norbornene. . The iodine value of the ester / α-olefin / non-conjugated diene copolymer rubber of the above (2) in which such a non-conjugated diene is copolymerized is preferably 25 or less, 5
-20 are more preferable. The Mooney viscosity [ML1 + 4 (121 ° C.)] of the copolymer rubber of (1) to (4) above is 10.
˜250 is preferable, and 30 to 150 is particularly preferable.

The crystallinity of the α-olefin random copolymer rubber is preferably less than 20% as measured by X-ray method.

The crosslinked olefin rubber (b) is a crosslinked product of the above-mentioned α-olefin random copolymer rubber, but it is preferably in a partially crosslinked state. Here, the state of being partially crosslinked means the case where the gel content measured by the method described later is 20 to 97%.

From the α-olefin random copolymer rubber,
The crosslinked olefin rubber (b) can be obtained by a method known per se, for example, a method in which an α-olefin random copolymer is melt-kneaded in the presence of a small amount of a crosslinking agent. At this time, a thermoplastic elastomer (a) containing the crystalline polyolefin resin (a) and the crosslinked olefin rubber (b) is allowed to coexist with the crystalline polyolefin resin (a) in a single operation by the method described in detail later. It is also possible to produce A).

In the thermoplastic elastomer (A), the crosslinked olefin rubber (b) is 100 in total of the crystalline polyolefin resin (a) and the crosslinked olefin rubber (b).
10 to 90 parts by weight, preferably 20 to 9 parts by weight
It is used in an amount of 0 part by weight, more preferably 30 to 90 parts by weight.

[III] Preferred Thermoplastic Elastomer (A) and Method for Preparing Thermoplastic Elastomer (A) The thermoplastic elastomer (A) preferably used in the present invention comprises a crystalline polypropylene resin and a crosslinked ethylene / α-olefin copolymer. Polymer rubber or cross-linked ethylene
Contains α-olefin / non-conjugated diene copolymer rubber,
In addition, the weight ratio of the crystalline polypropylene resin and the crosslinked olefin rubber (crystalline polypropylene resin / crosslinked olefin rubber) is in the range of 70/30 to 10/90.

As a more specific example of the thermoplastic elastomer (A) that is preferably used, a crystalline polypropylene resin (a) is used as the crystalline polyolefin resin (a).
As the cross-linked olefin rubber (b), cross-linked ethylene / propylene copolymer rubber and cross-linked ethylene / propylene /
At least one of the non-conjugated diene copolymer rubbers is contained, and the polymerization ratio thereof is 70/30 to 90/10 [(a) /
(B)], and further contains 5 to 100 parts by weight of a rubber other than the olefin rubber and / or a mineral oil-based softening agent described below per 100 parts by weight of the total amount of these components. .

The thermoplastic elastomer (A) used in the present invention is a blend containing a crystalline polyolefin resin (a) and an α-olefin random copolymer rubber,
It can be obtained by kneading in the presence of a cross-linking agent such as an organic peroxide while melting the blend.

Specific examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5- Dimethyl-2,5-di-
(Tert-Butylperoxy) hexyne-3,1,3
-Bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy)
-3,3,5-trimethylcyclohexane, n-butyl-
4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, ter
Examples thereof include t-butyl perbenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butyl cumyl peroxide.

Of these, 2,5-dimethyl-2,5-di- (tert-) is preferable in terms of odor and scorch stability.
Butylpentyloxy) hexane, 2,5-dimethyl-
2,5-Di- (tert-butylperoxy) hexyne-3,1,3-bis (tert-butyloxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane , N-
Butyl-4,4-bis (tert-butylperoxy)
Valerate is preferred, especially 1,3-bis (te
Most preferred is rt-butylperoxyisopropyl) benzene.

The organic peroxide is preferably 0.05 to 3 parts by weight, more preferably 0.1 parts by weight, based on 100 parts by weight of the crystalline polyolefin resin (a) and the α-olefin random copolymer rubber. It is used in a proportion of 1% by weight.

In the present invention, sulfur, p-quinonedioxime, p,
p'-dibenzoylquinone dioxime, N-methyl-N
-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N, N'-
Peroxy crosslinking aids such as m-phenylene dimaleimide; or multi-agents such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate and the like. Functional methacrylate monomers; multifunctional vinyl monomers such as vinyl butyrate and vinyl stearate can be blended.

By using the above compound,
A uniform and gentle crosslinking reaction of the α-olefin random copolymer rubber can be expected. Particularly, divinylbenzene is most preferred in the present invention. Divinylbenzene is easy to handle and has good compatibility with the crystalline polyolefin (a) and the α-olefin random copolymer rubber,
In addition, it has a function of solubilizing the organic peroxide and acts as a dispersant for the organic peroxide, so that a thermoplastic elastomer (A) having uniform cross-linking by heat treatment and having a good balance of fluidity and physical properties is obtained. To be

In the present invention, the above-mentioned crosslinking aid, polyfunctional methacrylate monomer or polyfunctional vinyl monomer is added to the entire melt-kneaded product in an amount of 0.
It is preferably used in an amount of 1 to 2% by weight, particularly 0.3 to 1% by weight. When the mixing ratio of the crosslinking aid, the polyfunctional methacrylate monomer or the polyfunctional vinyl monomer is within the above range, the thermoplastic elastomer (A) obtained is obtained.
Is a cross-linking aid, a polyfunctional methacrylate monomer or a polyfunctional vinyl monomer, which rarely remains as an unreacted monomer in the elastomer, so that there is little change in physical properties due to thermal history during processing, Moreover, it has excellent fluidity.

As the kneading device, conventionally known kneading devices,
For example, an open type mixing roll, a non-open type Banbury mixer, an extruder, a kneader, a continuous mixer and the like are used. Of these, a non-open type kneading device is preferable, and kneading is preferably performed in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.

The kneading is preferably carried out at a temperature at which the half-life of the organic peroxide used is less than 1 minute. The kneading temperature is usually 150 to 280 ° C, preferably 170 to 280 ° C.
The temperature is 240 ° C., and the kneading time is 1 to 20 minutes, preferably 1 to 5 minutes. The shearing force applied is usually 10 to 10 ⁴ sec ⁻¹ , preferably 10 ² to 10 at a shear rate.
It is in the range of ⁴ sec ^-1 . As described above, the thermoplastic elastomer (A) containing the crystalline polyolefin resin (a) and the crosslinked olefin rubber (b) can be obtained.

The term "crosslinked" as used herein means that the gel content (cyclohexane insoluble matter) measured by the following method is 10:
When it is more than%. In the present invention, the gel content of the thermoplastic elastomer is preferably 20% or more, more preferably 30% or more, and further preferably 4%.
0 to 97%. The thermoplastic elastomer having a gel content in the above range has good rubber elasticity, and can provide a molded product excellent in mechanical strength and elongation at break.

[Measurement method of gel content (cyclohexane-insoluble matter)] About 100 mg of a sample of a thermoplastic elastomer was weighed and cut into a piece of 0.5 mm x 0.5 mm x 0.5 mm, and then obtained. The strips are immersed in 30 ml of cyclohexane in a closed container at 23 ° C. for 48 hours.

Next, this sample is taken out on a filter paper and dried at room temperature for 72 hours or more until a constant weight is obtained. The value obtained by subtracting the weight of the cyclohexane-insoluble component (fibrous filler, filler, content, etc.) other than the polymer component from the weight of the dry residue is defined as "corrected final weight (Y)". On the other hand, from the weight of the sample, the weight of the cyclohexane-soluble component other than the polymer component (for example, the softening agent) and the cyclohexane-insoluble component other than the polymer component (fibrous filler, filler,
The value obtained by subtracting the weight of the pigment or the like) is defined as "corrected initial weight (X)". Here, the gel content (cyclohexane insoluble content) is calculated by the following mathematical formula.

[0030]

[Equation 1]

Poly 1-butene resin (B) As the poly 1-butene resin (B), the following (1),
The (co) polymers exemplified in (2) and (3) are preferably used. (1) 1-Butene homopolymer (2) Random copolymer of 1-butene and 10 mol% or less of other α-olefin (3) 1-butene and 30 mol% or less of other α-olefin The other α-olefin as the above-mentioned comonomer specifically includes ethylene, propylene, 4-methyl-1-pentene, 1-hexene, 1-octene and the like. Among them, a homopolymer of 1-butene or a random copolymer of 1-butene containing 1-butene as a main component and ethylene or propylene is particularly preferable. These α-olefins may be used alone or in combination of two or more.

The poly-1-butene resins may be used alone or in combination of two or more. MFR of poly 1-butene resin (B) (methol flow rate; ASTM D1)
238, 230 ℃, 2.16kg load) is 0.01-3
The range of 0 is preferable.

Thermoplastic elastomer composition and its preparation
Production Method The thermoplastic elastomer composition of the present invention comprises the above-mentioned thermoplastic elastomer (A), poly-1-butene resin (B) and
And a silicone oil (C) described later. The weight ratio [(A) / (B)] of these is 60/40.
˜5 / 95, preferably 59/41 to 10/90
And more preferably 55/45 to 20/80.

The thermoplastic elastomer composition of the present invention may be blended with a rubber other than an olefin rubber as an optional component, if necessary, within a range not impairing the achievement of the object of the present invention.

As the rubber other than the olefin rubber, for example, styrene-butadiene rubber (SBR), nitrile rubber (NBR), natural rubber (NR), butyl rubber (II
Examples thereof include diene rubbers such as R) and polyisobutylene rubbers.

Rubbers other than the above-mentioned olefinic rubbers can be added at any stage of producing the thermoplastic elastomer composition of the present invention. However, they should be added at the stage of preparing the above-mentioned thermoplastic elastomer (A). Is preferred.
The rubber other than the olefin rubber is preferably used in a ratio of 40 parts by weight or less, more preferably 5 parts by weight, based on 100 parts by weight of the total amount of the crystalline olefin resin (a) and the crosslinked olefin rubber (b). Used in a proportion of up to 20 parts by weight. By using a rubber other than the olefin rubber, a thermoplastic elastomer composition having excellent flexibility can be obtained.

Further, the thermoplastic elastomer composition of the present invention contains a silicone oil (C) for the purpose of improving scratch resistance. And the compounding quantity is 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the poly-1-butene resin (B). Is.

Specific examples of the silicone oil (C) include dimethyl silicone oil, phenylmethyl silicone oil, fluorosilicone oil, tetramethyltetraphenyltrisiloxane, modified silicone oil and the like. Among them, dimethyl silicone oil and phenylmethyl silicone oil are preferably used.

Kinematic viscosity of silicone oil (C) [JIS
K2283, 25 ° C] is 10 to 30,000 cS
t, preferably 50 to 10,000 cSt, more preferably 100 to 5,000 cSt.

[0040]

[0041]

[0042]

The silicone oil (C) component may be blended in advance with at least one of the thermoplastic elastomer (A) and the poly-1-butene resin (B).

Further, in the present invention, in the thermoplastic elastomer composition, known mineral oil type softeners, inorganic fillers and heat stabilizers may be added, if necessary, to the extent that the object of the present invention is not impaired. Additives such as antiaging agents, weathering stabilizers, antistatic agents, lubricants exemplified by metal soaps and waxes can be added. These are
It may be blended with at least one of the thermoplastic elastomer (A) and the poly-1-butene resin (B).

Specific examples of such an inorganic filler include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, barium sulfate, aluminum sulfate, calcium sulfate and magnesium carbonate. , Molybdenum disulfide, glass fiber, glass sphere, shirasu balloon, graphite, alumina and the like.

Examples of known heat stabilizers, antiaging agents and weathering stabilizers include phenol type, sulfite type, phenylalkane type, phosphite type and amine type stabilizers.

The thermoplastic elastomer composition of the present invention comprises
It can be prepared by blending the thermoplastic elastomer (A), the poly-1-butene resin (B), and the silicone oil (C) in the above-mentioned proportions and melt-kneading.

[0048] Further, in the preparation of the thermoplastic elastomer composition of the present invention, in formulating the respective components described above, if necessary, rubber other than o olefin-based rubber, be blended other aforementioned optional ingredients it can.

As the above-mentioned melt-kneading method, the melt-kneading method described above in the preparation of the thermoplastic elastomer (A) is preferable.

[0050]

EXAMPLES The present invention will be specifically described below based on examples. Examples 1 and Comparative Examples 1 to 3 (I) Ethylene / propylene / ethylidene norbornene terpolymer rubber (ethylene unit / propylene unit (molar ratio): 78/22, iodine: 15, Mooney viscosity ML
1 + 4 (121 ° C.): 61) 80 parts by weight, and (II) crystalline isotactic polypropylene (MFR: 13 g /
Mixture 10 consisting of 20 parts by weight for 10 minutes (230 ° C)
To 0 parts by weight, 0.7 parts by weight of a pre-prepared mixture (50% by weight of (III) di-tert-butyl peroxide, 40% by weight of divinylbenzene and 10% by weight of paraffinic mineral oil) was added and stirred with a Henschel mixer. Mixed.

Then, the mixture thus obtained was fed into the cylinder from the hopper of the twin-screw extruder and directly injected into the cylinder portion using a plunger pump so that the paraffinic process oil amounted to 19 parts by weight. Pellets of the thermoplastic elastomer (TPO) were manufactured by extruding at 210 ° C. in the atmosphere. The gel content was 90%.

Next, TPO pellets, 1-butene homopolymer (MFR: 20 g / 10 minutes (230 ° C.)) pellets and silicone oil (C) were mixed in the ratios shown in Table 1 with a Henschel mixer, and then mixed. The pellets of the thermoplastic elastomer composition were manufactured again by kneading with a twin-screw extruder. From the obtained thermoplastic elastomer pellets, using an injection molding machine, a square plate (150 mm × 150
mm × 3 mm) was molded at 220 ° C. Then, a 20 mm square felt cloth was placed on the obtained square plate, and a weight was placed thereon so that a pressure of 200 g / cm ² was applied, and the cloth was reciprocated 100 times on the square plate. The surface resistance was evaluated by 5 grades of scratch resistance. (Five-step evaluation of scratch resistance) A: Almost no scratch is noticeable B: Scratch is slightly noticeable C: Scratch is noticeable D: Scratch is noticeably noticeable E: Surface whitening results are shown in Table 1.

[0053]

[Table 1]

The components shown in Table 1 are as follows. [Silicone oil (C)]: Toray Silicone Co., S
H 200

[0055]

EFFECTS OF THE INVENTION The thermoplastic elastomer of the present invention is lightweight, easy to recycle and uses the advantages of the olefin polymer material such as not generating harmful gas even when incinerated, and is excellent in scratch resistance. . Therefore, it can be used for automobile interior and exterior parts.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 83:04) (56) References JP-A-1-123847 (JP, A) JP-A-6-256538 (JP, A) Practical Plastics Encyclopedia, Material, Industrial Research Council Encyclopedia Publishing Center, May 1, 1993, 293-297, 403, 822-825 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 1 / 00-101/16 C08K 3/00-13/08

Claims (5)

(57) [Claims] 1. A thermoplastic elastomer (A) containing a crystalline polyolefin resin (a) and a crosslinked olefin rubber (b), a poly-1-butene resin (B) and a silicone oil (C). And the weight ratio of the thermoplastic elastomer (A) to the poly-1-butene (B) [(A) /
(B)] is and is in the range of 60 / 40-5 / 95 on SL
Silicone oil (C) as thermoplastic elastomer (A)
And 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the poly-1-butene resin (B), a thermoplastic elastomer composition. 2. The thermoplastic polyolefin (A) contains the crystalline polyolefin resin (a) in a total amount of 1 of the crystalline polyolefin resin (a) and the crosslinked olefin rubber (b).
10. 1 to 70 parts by weight relative to 00 parts by weight.
The composition according to. 3. In the thermoplastic elastomer (A), at least one rubber selected from styrene-butadiene rubber, nitrile rubber, natural rubber, butyl rubber and polyisobutylene rubber and / or a mineral oil-based softening agent is crystalline. The composition according to claim 1, further comprising 5 to 100 parts by weight based on 100 parts by weight of the total amount of the polyolefin resin (a) and the crosslinked olefin rubber (b). 4. The crystalline polyolefin resin (a) is a crystalline polypropylene resin, and the crosslinked olefin rubber (b) is an ethylene / propylene random copolymer rubber or an ethylene / propylene / non-conjugated diene random copolymer rubber. The composition according to any one of claims 1 to 3, which is at least one of crosslinked rubbers. 5. The thermoplastic elastomer (A) is obtained by melting and kneading a crystalline polyolefin resin (a) and a crosslinked olefin rubber (b) in the presence of an organic peroxide. The composition according to any of the above.