JP2002167479A - Thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer composition capable of keeping a slidability in the long term, while displaying the excellent slidability from a starting point. SOLUTION: This thermoplastic elastomer composition is obtained by blending 0.05-20 pts.wt., polyolefin resin (B) having an organopolysiloxane graft- copolymerized content of 30-70 wt.%, with 0.05-5 pts.wt., organopolysiloxane (C) per 100 pts.wt. olefin-based elastomer (A).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition, and more particularly, to a thermoplastic elastomer composition having excellent slidability.

[0002]

2. Description of the Related Art In recent years, thermoplastic elastomers, which are rubber-like soft materials and do not require a vulcanization step and have the same moldability as thermoplastic resins, have been used for automobile parts, home appliance parts, medical care and foodstuffs. It is used in fields such as equipment parts, electric wires, and miscellaneous goods. In particular, parts requiring slidability are multi-layered with a thermoplastic elastomer having excellent slidability.

[0003] With respect to the improvement of the sliding properties of thermoplastic elastomers, for example, Japanese Patent Application Laid-Open No. Hei 9-176408 discloses that (1) fatty acid amide 0.1 parts per 100 parts by weight of thermoplastic elastomer (composition). To 5 to 100 parts by weight of a polyolefin resin or (2) 0.1 to 5 parts by weight of a fatty acid amide and 0.1 to 10 parts by weight of an organopolysiloxane. I have. Japanese Patent Application Laid-Open No. 2000-17082 proposes a method in which a polyolefin grafted with a silicone polymer (organopolysiloxane) is blended so that the silicone polymer content is 5 to 50% by weight.

However, according to a detailed study on the slidability by the present inventors, the method described in Japanese Patent Application Laid-Open No. 9-176408 is inferior in long-term slidability,
The method described in Japanese Patent No. 7082 is inferior in initial slidability.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object of the present invention is to develop excellent slidability from the beginning and maintain the slidability for a long period of time. An object of the present invention is to provide a thermoplastic elastomer composition that can be used.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that if the specific components are used in combination, the above objects can be easily achieved by the synergistic effect of the two. Thus, the present invention was completed.

That is, the gist of the present invention is that 0.05 to 20 parts by weight of a polyolefin resin (B) having a graft copolymerization amount of an organopolysiloxane of 30 to 70% by weight per 100 parts by weight of an olefin elastomer (A). And an organopolysiloxane (C) in an amount of 0.05 to 5 parts by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

First, the olefin elastomer (A) used in the present invention will be described. As the olefin-based elastomer (A), olefin-based rubber (rubber-like olefin copolymer) (a) and propylene-based polymer (b)
And the main component is suitable. Examples of such olefin-based elastomers include commercially available products such as "Thermolan" manufactured by Mitsubishi Chemical Corporation, "Millastomer" manufactured by Mitsui Petrochemical Company, "Sumitomo TPE" manufactured by Sumitomo Chemical Co., Ltd. and "Santoprene" manufactured by AES Japan Co., Ltd. .

The olefin rubber (a) which is a main component of the olefin elastomer (A) includes ethylene-propylene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), ethylene −
1-butene-non-conjugated diene copolymer rubber, propylene
Elastic copolymers containing an olefin as a main component, such as 1-butene-non-conjugated diene copolymer rubber, may be used. Of these, EPDM is preferred.

Examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene, with ethylidene norbornene being particularly preferred. A more preferred specific example of the olefin rubber (a) is EPDM having an ethylene content of 55 to 75% by weight and a non-conjugated diene content of 1 to 10% by weight. If the ethylene content is less than 55% by weight, the extrudability decreases, and the
If the amount is more than the percentage by weight, flexibility tends to be lost.

On the other hand, the propylene-based polymer (b), which is another component of the olefin-based elastomer (A), is not particularly limited, but may be polypropylene or a copolymer of polypropylene and an α-olefin having 2 or more carbon atoms. Is preferred. Specific examples of the α-olefin having 2 or more carbon atoms include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-decene, 3-methyl-1-pentene, -Methyl-1-pentene, 1-octene and the like.

The melt flow rate (MFR) of the propylene-based polymer (b) was measured at a temperature of 230 ° C. and a load of 2 according to Table 1 of JIS K-7210, condition 14.
As a value of 1.18 N, usually 0.01 to 30 g / 10
Min, preferably in the range of 0.1 to 20 g / min. MF
When R is out of the above range, there is a possibility that a problem occurs in the moldability.

In the olefin elastomer (A), the content ratio of the olefin rubber (a) and the propylene polymer (b) is as follows. That is, the olefin rubber (a) is usually 20
To 80% by weight, preferably 30 to 70% by weight, and the propylene polymer (b) is 80 to 20% by weight, preferably 70 to 70% by weight.
３０30% by weight. When the use ratio of the olefin-based rubber (a) is less than 20% by weight, the flexibility of the composition and the obtained molded article is lost, and when the use ratio of the olefin-based rubber (a) exceeds 80% by weight, the sliding is performed. Mobility and scratch resistance tend to deteriorate.

The olefin-based elastomer (A) is preferably one obtained by dynamically heat-treating a mixture of the olefin-based rubber (a) and the propylene-based polymer (b) in the above ratio in the presence of a vulcanizing agent. Examples of the vulcanizing agent include an organic peroxide, a phenol resin, and sulfur. Of these, organic peroxides are preferred.

As the organic peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane,
5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) -3, 5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, dicumyl peroxide and the like. Among these, especially in terms of odor and scorch,
2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t-
Butylperoxy) hexyne-3 is preferred.

Further, a crosslinking assistant can be used together with the vulcanizing agent. The main crosslinking aids include p-quinone dioxime, nitrosobenzene, diphenylguanidine, N-
Methyl-N-4-dinitrosoaniline, trioxylpropane-N, N-m-phenylenedimaleimide, a peroxy crosslinking auxiliary such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, Examples include polyfunctional methacrylate monomers such as polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate. A uniform and mild crosslinking reaction can be expected by using the above compounds.

The amount of the vulcanizing agent used is usually 0.005 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the olefin elastomer (A). If the amount of the vulcanizing agent is less than 0.005 parts by weight, the effect of the crosslinking reaction is small. The amount of the crosslinking aid to be used is usually 0.005 to 4 parts by weight, preferably 0.05 to 3 parts by weight, per 100 parts by weight of the olefin elastomer (A). If the amount of the crosslinking aid is less than 0.005 parts by weight, no effect is exhibited, and if it is more than 4 parts by weight, it is not economically advantageous.

Next, the components used in the present invention will be described. In the present invention, as an essential compounding component,
Polyolefin resin (B) and organopolysiloxane (C) are used, and fatty acid amide (D) and polyolefin resin (E) are used as optional components.

The polyolefin resin (B) used in the present invention is a polyolefin resin having a graft copolymerization amount of an organopolysiloxane of 30 to 70% by weight. Examples of such a resin include “SP300” and “SP350” manufactured by Dow Corning Asia Co., Ltd., and “BY27-201” manufactured by Dow Corning Silicone Toray Co., Ltd.
There are commercially available products such as "BY27-202". When the amount of the organopolysiloxane graft copolymerized is less than 30% by weight, the durability of the slidability is insufficient, and when the amount is more than 70% by weight, the production is difficult.

The organopolysiloxane (C) used in the present invention includes dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, epoxy-modified, alkyl-modified, amino-modified,
Various modified polysiloxanes such as carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl-polyether-modified, epoxy-polyether-modified, and polyether-modified are exemplified.

In the present invention, fatty acid amides (D) include monoamides of higher fatty acid amides such as stearylamide, oxystearylamide, oleylamide, erucylamide, laurylamide, palmitylamide, behenylamide, methylolamide, methylenebis Amide types of higher fatty acids such as stearylamide, ethylenebisstearylamide, ethylenebisoleylamide, ethylenebislauramide, stearyloleylamide, N
-Complex amides such as stearyl ercrylamide and N-oleyl palmitylamide.

In the present invention, as the polyolefin resin (E), various polyolefins obtained from one or more monoolefins as raw materials and obtained as a high molecular weight solid product containing a crystal component by a high pressure method or a low pressure method Resins. Examples of the raw material monoolefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-1-propene, 3-methyl-1 pentene, 4-methyl-1-pentene, and 5-methyl- 1-hexene and mixtures thereof.
As the polyolefin resin (E), polyethylene or polypropylene is preferably used.

Next, the amounts of the above components will be described. All are values per 100 parts by weight of the olefin-based elastomer (A).

The blending amount of the polyolefin resin (B) is
0.05 to 20 parts by weight, preferably 0.5 to 10 parts by weight.
Parts by weight. The amount of the organopolysiloxane (C) is 0.05 to 5 parts by weight, preferably 0.1 to 5 parts by weight.
1 to 5 parts by weight. The effect of the present invention, that is, the excellent slidability obtained from the initial stage over a long period of time, can be obtained from the above (B)
And a synergistic effect of the component (C). Therefore, when the amount of each component is less than the above range, the object of the present invention cannot be achieved. When the blending amount of the polyolefin resin (B) exceeds 20 parts by weight, the flexibility of the obtained composition is lost, and when the blending amount of the organopolysiloxane (C) exceeds 5 parts by weight, kneading is performed. At the time of molding or at the time of molding, the workability deteriorates.

The fatty acid amide (D) and the polyolefin resin (E) are used for further improving the slidability of the thermoplastic elastomer composition. The amount of the fatty acid amide (D) is usually 0.05 to 5 parts by weight, preferably 0.05 to 5 parts by weight.
３3 parts by weight. When the amount is less than 0.05 part by weight, the effect of improving the slidability by the fatty acid amide (D) cannot be obtained. When the amount exceeds 5 parts by weight, slip occurs during kneading or molding and the processing is performed. It becomes worse. The compounding amount of the polyolefin resin (E) is usually 5 to 80 parts by weight, preferably 10 to 60 parts by weight. If the amount is less than 5 parts by weight, the effect of improving the slidability by the polyolefin resin (E) cannot be obtained. May cause whitening.

In the present invention, a mineral oil-based softener can be used in order to further improve the mechanical properties and workability. Examples of the mineral oil-based softener include paraffin-based, naphthene-based, and aromatic-based softeners, and paraffin-based softeners are particularly preferable. The minimum amount of the mineral oil-based softener is usually 0.1 part by weight per 100 parts by weight of the olefin elastomer (A).

In the thermoplastic elastomer composition of the present invention, in addition to the above-mentioned components, other optional components can be blended according to various purposes within a range that does not significantly impair the effects of the present invention. Such components include, for example, fillers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers,
Neutralizing agents, lubricants, anti-fog agents, anti-blocking agents, slip agents, dispersants, coloring agents, flame retardants, antistatic agents, conductivity-imparting agents, metal deactivators, molecular weight regulators, antibacterial agents, Examples of the additives include various additives such as molds, fluorescent whitening agents, etc., thermoplastic resins and elastomers other than the above essential components, fillers, and the like.

Examples of the thermoplastic resin other than the essential components include ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic ester copolymer, ethylene・ Polyoxy resins such as methacrylic acid ester copolymers, polyphenylene ether resins, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene homopolymers and polyoxymethylene copolymers Examples include a methylene resin and a polymethyl methacrylate resin.

The elastomers other than the above essential components include, for example, styrene / butadiene copolymer rubber,
Styrene-based elastomers such as styrene-isoprene copolymer rubber or hydrogenated products thereof are exemplified. Furthermore,
Examples of the filler include glass fiber, hollow glass sphere, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, titanium dioxide, and carbon black.

The thermoplastic elastomer composition of the present invention can be produced, for example, as follows.

The olefin rubber (a) and the propylene polymer (b) are subjected to a dynamic heat treatment as a mixture in the presence of a vulcanizing agent. Here, "dynamically heat-treating" refers to kneading in a molten state. The heat treatment is performed using a kneading device such as a Banbury mixer, a mixing roll, a kneader, and an extruder. When an organic peroxide is used as the vulcanizing agent, the heat treatment temperature is preferably a temperature at which the half life of the organic peroxide used is less than 1 minute, and is usually selected from 130 to 280 ° C. The time is usually selected from a range of 1 to 30 minutes.

Other components such as a mineral oil-based softener can be mixed at any stage. For example, the mineral oil-based softener may be added to the olefin-based rubber (a) in advance.

[0034] The thermoplastic elastomer composition of the present invention comprises:
Molding can be easily performed with an apparatus used for ordinary thermoplastic resins, and extrusion molding, injection molding, and the like can be performed. The composition of the present invention is particularly suitable for a surface member of a molded article. Applications of the thermoplastic elastomer composition of the present invention include automotive parts such as roof molding and window molding.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the following, “%” means% by weight, and “parts” means parts by weight. The materials and test methods used as the components in the following examples are as follows.

<Materials> (a): Ethylene-propylene-ethylidene norbornene copolymer rubber (ethylene content 70%, ethylidene norbornene content 5.5%), oil extension 100%, ML = 40
0, (ML: Mooney viscosity (ML1 + 4 100 ° C),
(Based on ASTM D-927-57T)

(B): Propylene copolymer (MFR)
(230 ° C, 21.18N, JIS K6758 compliant)
= 0.7g / 10min)

(B): Organopolysiloxane-grafted polyolefin ("SP35" manufactured by Dow Corning Asia Ltd.)
0 ")

(C): Organopolysiloxane (“SH200” manufactured by Dow Corning Toray)

(D): Oleylamide

(E): polyethylene-based polymer (density of 0.
958 g / cm ³ , MFR (190 ° C., 21.18 N,
(Based on JIS K6760) = 20g / 10min)

POX: 2,5-dimethyl-2,5-di (t-butylperoxy) hexane

TMP: trimethylolpropane trimethacrylate

<Test Method> (1) Molding of Sample: Using a φ40 mm single screw extruder (L / D = 22, compression ratio: 2.8, full flight screw) manufactured by Mitsubishi Heavy Industries, under molding temperature hopper: 160 ° C. Cylinder: 170-190 ° C., Die: 180 ° C., Screw rotation speed: 25 rpm, molding is performed under the conditions of 25 × 1 mm.
A flat belt-shaped extruded product was obtained.

(2) Friction test and measurement of friction coefficient: For the friction test, a Haydon scratch tester was used, a cotton cloth (Kanakin No. 3) was placed as an indenter on the surface of the extruded product, and a load of 1 kg was applied. It was reciprocated 200 times. The friction coefficient of each test piece before / after the friction test was measured using a friction coefficient measuring machine of Toyo Seiki Seisaku-sho, using an indenter with a load of 300 g and moving at a speed of 100 mm / min with a load of 300 g after the initial peak. Each coefficient was calculated with the steady state as dynamic friction.

Example 1 2 parts by weight of the component (B), 0.5 part by weight of the component (C), and 100 parts by weight of a mixture of 50% of the component (a) and 50% of the component (b) per 100 parts (component (A)) 21 parts, TMP0.5
After blending 7 parts and blending with a Henschel mixer for 1 minute, the same direction twin screw extruder (“KTX4 made by Kobe Steel”
No. 4 ", L / D = 41, number of cylinder blocks = 11), and the mixture was charged at a rate of 40 kg / h into a first supply port, melt-kneaded and pelletized. Using these pellets, a test was conducted by the method described above, and the evaluation results are shown in Table 1. In the following examples, the above-described extruder was used.

Example 2 2 parts by weight of component (B), 0.5 part by weight of component (C), and 100 parts by weight of a mixture of component (a) 50% and component (b) 50% (component (A)) D) 0.15 parts by weight, PO
After 0.21 part of X and 0.57 part of TMP were blended and blended by a Henschel mixer for 1 minute, the mixture was charged into the first supply port of the extruder at a rate of 40 kg / h and melt-kneaded to form pellets. Using these pellets, a test was conducted by the method described above, and the evaluation results are shown in Table 1.

Example 3 2 parts by weight of the component (B), 0.5 part by weight of the component (C), 100 parts by weight of a mixture of 55% by weight of the component (a) and 45% by weight of the component (b) 21 parts, TMP0.5
After mixing 7 parts and blending with a Henschel mixer for 1 minute, the mixture was introduced into the first supply port of the extruder at a rate of 40 kg / h, and the component (E) was further supplied through the second supply port provided in the middle of the extruder. The mixture was charged to 20 parts by weight, melt-kneaded, and pelletized. Using these pellets, a test was conducted by the method described above, and the evaluation results are shown in Table 1.

Comparative Example 1 4 parts by weight of component (B) per 100 parts of a mixture (component (A)) of 50% of component (a) and 50% of component (b), POX
After 0.21 part and 0.57 part of TMP were blended and blended for 1 minute with a Henschel mixer, the mixture was charged into the first supply port of the extruder at a rate of 40 kg / h and melt-kneaded to form pellets. Using these pellets, a test was conducted by the method described above, and the evaluation results are shown in Table 1.

Comparative Example 2 0.5 part by weight of component (C) per 100 parts of a mixture of component (a) 50% and component (b) 50% (component (A))
(D) 0.15 part by weight, POX 0.21 part, TMP0.
After blending 57 parts and blending for 1 minute with a Henschel mixer, the mixture was charged into the first supply port of the extruder at a rate of 40 kg / h and melt-kneaded to form pellets. Using these pellets, a test was conducted by the method described above, and the evaluation results are shown in Table 1.

[0051]

[Table 1]

From Table 1, it can be seen that the initial and long-term slidability is maintained by blending the polyolefin resin (B) obtained by grafting a silicone polymer onto the olefin elastomer (A) and the organopolysiloxane (C). I understand.

[0053]

According to the present invention described above, there is provided a thermoplastic elastomer composition capable of exhibiting excellent slidability from the beginning and maintaining the slidability for a long period of time. The industrial value is great.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08L 83:04) C08L 83:04) F-term (reference) 4J002 BB031 BB051 BB121 BB122 BB141 BB151 BB152 BB171 CP034 CP044 CP054 CP084 CP094 CP173 CP184 EP016 EP026 FD010 FD140 FD150 GM00 GN00

Claims (4)

[Claims] 1. An olefin-based elastomer (A) 100
Polyolefin resin (B) having a graft copolymerization amount of organopolysiloxane of 30 to 70% by weight per part by weight
A thermoplastic elastomer composition comprising 0.05 to 20 parts by weight of an organopolysiloxane (C) and 0.05 to 5 parts by weight. 2. An olefin-based elastomer (A) 100
The thermoplastic elastomer composition according to claim 1, wherein the fatty acid amide (D) is incorporated in an amount of 0.05 to 5 parts by weight per part by weight. 3. An olefin-based elastomer (A) 100
5-100 parts by weight of polyolefin resin (E) per part by weight
3. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition is blended in parts by weight. 4. A olefin-based elastomer (A) comprising a mixture comprising 30 to 80% by weight of an olefin-based rubber (a) and 70 to 20% by weight of a propylene-based polymer (b) is dynamically mixed in the presence of a vulcanizing agent. The thermoplastic elastomer composition according to any one of claims 1 to 3, which is a heat-treated composition.