JP2003183465A - Thermoplastic elastomer composition for extrusion molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition for extrusion molding reduced in generation of gum on extrusion molding. <P>SOLUTION: The thermoplastic elastomer composition for extrusion molding comprises 100 pts.wt. of a wholly or partially crosslinked olefinic elastomer (A) and, incorporated therewith, 0.05-5 pts.wt. of a fatty acid amide (B) having a melting point of at least 125°C. <P>COPYRIGHT: (C)2003,JPO

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 for extrusion molding, and more particularly to an olefin-based elastomer composition for extrusion molding in which the occurrence of dents during extrusion molding is reduced.

[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 electric appliance parts, medical care and food products. It is used in the fields of equipment parts, electric wires and sundries. By the way, a completely or partially cross-linked olefinic elastomer, which is a kind of the above-mentioned thermoplastic elastomer, has excellent rubber elasticity, heat resistance, lightweight property, and weather resistance, but when it is extruded, it adheres to a die of an extruder ( There is a problem in that a large amount of so-called mess is generated.

As a method for reducing the occurrence of the above-mentioned burr, for example, a method of adding a fatty acid amide and a polyolefin resin or an organopolysiloxane to a thermoplastic elastomer, as proposed in JP-A-9-176408, As proposed in Japanese Patent Laid-Open No. 2000-95900, a thermoplastic elastomer has a viscosity of 1 × 1.
There is a method of adding both 0 ⁶ cst or more and 10 to 10 ⁶ cst of polysiloxane in combination, but the sufficient effect is not always obtained, and when the addition amount is increased, the problem that the additive bleeds to the surface is there.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a thermoplastic elastomer composition for extrusion molding in which the occurrence of dents during extrusion molding is reduced. Especially.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that the blending of a specific material into an olefin-based elastomer can reduce the body loss, and has completed the present invention. I arrived.

That is, the gist of the present invention is that fatty acid amide (B) having a melting point of 125 ° C. or higher per 100 parts by weight of completely or partially crosslinked olefinic elastomer (A).
A thermoplastic elastomer composition for extrusion molding is characterized by being compounded in an amount of 0.05 to 5 parts by weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

<Olefin Elastomer (A)> The completely or partially crosslinked olefin elastomer (A) used in the present invention is an olefin rubber (rubber-like olefin copolymer) (A1) and a propylene polymer. (A
2) is an elastomer whose main component is. Examples of such olefin elastomers include "Thermoran" manufactured by Mitsubishi Chemical Co., Ltd., "Milastomer" manufactured by Mitsui Petrochemical Co., Ltd.,
There are commercially available products such as "Sumitomo TPE" manufactured by Sumitomo Chemical Co., Ltd. and "Santoprene" manufactured by AES Japan. In the present invention, it is preferable to select and use a grade suitable for various physical properties required.

As the olefin rubber (A1) which is an essential component of the olefin elastomer (A), ethylene-propylene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), ethylene Examples thereof include elastic copolymers containing olefin as a main component such as -1-butene-non-conjugated diene copolymer rubber and propylene-1-butene-non-conjugated diene copolymer rubber. Of these, EPDM is preferred.

Examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene and the like, but ethylidene norbornene is particularly preferable. A more preferable 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 will be reduced to 75
If it is more than wt%, flexibility tends to be lost.

Similarly, the propylene polymer (A2), which is an essential component of the olefin elastomer (A), is not particularly limited, but polypropylene or polypropylene and a copolymerization weight of the α-olefin having 2 or more carbon atoms are copolymerized. Coalescence 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, 4-methyl-1-pentene, 1-octene and the like can be mentioned.

The melt flow rate (MFR) of the above-mentioned propylene polymer (A2) is usually 0.1 as a value at a temperature of 230 ° C. and a load of 21.18 N measured according to condition 14 of Table 1 of JIS K-7210. 01-30g / 10
Min, preferably 0.1 to 20 g / 10 min.
If the MFR is out of the above range, there may be a problem in moldability.

In the olefin elastomer (A), the proportion of each component used is as follows. The olefin-based rubber (A1) is usually 20 to 90% by weight, preferably 30 to 80% by weight, based on the total amount of the olefin-based rubber (A1) and the propylene-based polymer (A2), and the propylene-based polymer (A2). Is 10 to 80% by weight, preferably 20 to 70
% By weight. When the proportion of the olefin rubber (A1) used is less than 20% by weight, the flexibility of the composition and the resulting molded article is lost, and when the proportion of the olefin rubber (A1) used is more than 90% by weight, molding is performed. Sex deteriorates.

In the present invention, the olefin elastomer (A) is used after being completely or partially crosslinked for the purpose of imparting rubber elasticity and softening. Vulcanizing agents used for complete or partial crosslinking include organic peroxides,
Phenol resins, sulfur, etc. may be mentioned, but organic peroxides are preferred.

As the organic peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 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, Examples include 5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, dicumyl peroxide and the like. Among them, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t) is particularly preferable in terms of odor and scorch.
-Butylperoxy) hexyne-3 is preferred.

In the present invention, a crosslinking aid may be used in combination with the vulcanizing agent. The main cross-linking aids are sulfur, p-quinone dioxime, nitrosobenzene,
Diphenylguanidine, N-methyl-N-4-dinitrosoaniline, trimethylolpropane-N, N'-m-
Peroxy crosslinking aids such as phenylene dimaleimide,
Examples thereof include polyfunctional methacrylate monomers such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate. By using the compound as described above,
A uniform and mild crosslinking reaction can be expected.

The amount of the vulcanizing agent used is usually 0.00 per 100 parts by weight of the olefin elastomer (A).
It is 5 to 5 parts by weight, preferably 0.05 to 2 parts by weight.
When the amount of the vulcanizing agent used is less than 0.005 parts by weight, the effect of the crosslinking reaction is small, and when it is more than 5 parts by weight, the extrusion appearance is deteriorated and it is not economically advantageous. The amount of the crosslinking aid used is usually 0.005 to 4 parts by weight, preferably 0.05, based on 100 parts by weight of the olefin elastomer (A).
~ 3 parts by weight. If the addition 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.

<Fatty acid amide (B) having a melting point of 125 ° C. or higher> The fatty acid amide having a melting point of 125 ° C. or higher used in the present invention is, for example, a bisamide type such as methylene bis stearoamide or ethylene bis stearoamide. It is a higher fatty acid amide. These may be used alone or in combination of two or more. The upper limit of the melting point of fatty acid amide (B) is usually 170 ° C.
Is.

The amount of the fatty acid amide (B) having a melting point of 125 ° C. or higher is 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, per 100 parts by weight of the olefinic elastomer (A). It is a department. If the amount is less than 0.05 parts by weight, the effect of reducing the generation of porcelain is small, and if the amount is more than 5 parts by weight, the fatty acid amide causes a bleeding phenomenon and causes porridge.

<Fatty acid amide (C) having a melting point of less than 125 ° C.> The melting point used in the preferred embodiment of the present invention is 125.
The fatty acid amide below ℃, for example, stearoamide, oxystearoamide, oleyl amide, erucyl amide, lauryl amide, palmityl amide, monoamide type of higher fatty acids such as behenamide,
Modified monoamides such as methylol amide and ethylol amide, and composite amides such as stearyl oleyl amide and N-stearyl erucamide. These may be used alone or in combination of two or more. The lower limit of the melting point of fatty acid amide (C) is usually 55 ° C.

The fatty acid amide (C) having a melting point of less than 125 ° C. is used in an amount of 0.01 to 3 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the olefinic elastomer (A). It is a department. If the amount is less than 0.01 part by weight, the effect of reducing the generation of porcelain is small, and if the amount is more than 3 parts by weight, the fatty acid amide causes a bleeding phenomenon and causes porridge.

<Organopolysiloxane (D)> The organopolysiloxane used in the preferred embodiment of the present invention is
Dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, etc., and
These are modified polysiloxanes such as epoxy modified, alkyl modified, amino modified, carboxyl modified, alcohol modified, and fluorine modified. These may be used alone or in combination of two or more.

The amount of the organopolysiloxane (D) used is the above-mentioned olefin elastomer (A) 10
It is usually 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 0 parts by weight. If the amount is less than 0.05 parts by weight, the effect of reducing the occurrence of mesiness will be small, and if the amount is more than 10 parts by weight, the surface of the molded product will become sticky, and conversely will cause mesiness.

Further, in the present invention, a mineral oil-based softening agent can be used in order to further improve mechanical properties and workability. Such mineral oil-based softeners include types such as paraffin-based, naphthene-based, and aromatic-based softeners.
A paraffin softener is particularly preferable. The mineral oil-based softening agent is an olefin-based rubber (a) and a propylene-based polymer (b) constituting the above-mentioned olefin-based elastomer (A).
150 parts by weight or less per 100 parts by weight of the mixture of
It is preferably 130 parts by weight or less. When a mineral oil-based softening agent is used, the minimum amount thereof is usually 0.1 part by weight per 100 parts by weight of the olefin rubber (a) and propylene polymer (b) mixture.

In addition to the above-mentioned components, the thermoplastic elastomer composition of the present invention may contain other optional components in accordance with various purposes within the range of not significantly impairing the effects of the present invention. Examples of such components include fillers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers,
Neutralizer, antifogging agent, antiblocking agent, slip agent,
Dispersant, colorant, flame retardant, antistatic agent, conductivity imparting agent,
Examples include various additives such as metal deactivators, molecular weight modifiers, antibacterial agents, mildew-proofing agents, optical brighteners, thermoplastic resins and elastomers other than the above essential components, and fillers.

As the thermoplastic resin other than the above essential components, for example, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid ester copolymer, Ethylene copolymers such as ethylene / methacrylic acid ester copolymers, polyolefin resins such as polyethylene and polybutene-1 resins, polyphenylene ether resins, polyamide resins such as nylon 6 and nylon 66, polyethylene terephthalate, polybutylene terephthalate Polyester resin such as polyoxymethylene homopolymer,
Examples thereof include polyoxymethylene-based resins such as polyoxymethylene copolymers and polymethylmethacrylate-based resins.

Examples of elastomers other than the above essential components include styrene elastomers such as styrene / butadiene copolymer rubber and styrene / isoprene copolymer rubber. Furthermore, as a filler,
Examples thereof 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 manufactured, for example, as follows.

A mixture of the olefin rubber (a) and the propylene polymer (b) is dynamically heat treated in the presence of a vulcanizing agent. Here, "dynamically heat-treating" means kneading in a molten state. The above 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 the range of 1 to 30 minutes.

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

The thermoplastic elastomer composition of the present invention comprises
It can be easily extruded using the equipment used for ordinary thermoplastic resins. The thermoplastic elastomer composition of the present invention is suitable for use as automotive parts such as glass run channels, roof moldings and window moldings, profile extrusion moldings such as gaskets, sheets molded by a T-die molding machine and the like.

[0032]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. The materials used as the components in the following examples are as follows.

(A1): Ethylene-propylene-ethylidene norbornene copolymer rubber (ethylene content 70%,
Ethylidene norbornene content 5.5%), oil extension 100
%, ML = 400, (ML: Mooney viscosity (ML1 + 4
100 ° C), based on ASTM D-927-57T)

(A2): Propylene-based copolymer (MFR
(230 ° C., 21.18N, measured according to JIS K-7210, Table 1, condition 14) = 0.7 g / 10 minutes)

(B): Methylenebis stearoamide (melting point: 138 ° C.)

(C): Amide oleate (melting point: 70
℃)

(D): Organopolysiloxane-polypropylene masterbatch ("BY27-001" manufactured by Toray Dow Corning KK; ultra high molecular weight silicone oil content 50%)

(E): Organopolysiloxane (“SH200” manufactured by Toray Dow Corning Co., Ltd .: 100 cSt)

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

TMP: trimethylolpropane trimethacrylate

OIL: Paraffin type process oil ("PW-380" manufactured by Idemitsu Petrochemical Co., Ltd.)

The evaluation method is as follows.

<Measurement of the amount of porcelain production> φ40 manufactured by Mitsubishi Heavy Industries
mm single-screw extruder (L / D = 22, full flight screw with compression ratio of 2.8), flat belt-shaped die of 25 × 1 mm, molding temperature under hopper: 160 ° C., cylinder: 170-190 ° C. Extrusion was performed for 1 hour under the conditions of a die: 180 ° C. and a screw rotation speed: 25 rpm.
After that, the extruder was stopped and the porcelain attached to the die was sampled and its weight was measured.

<Evaluation of Surface Bleed> The flat belt-shaped extrusion molded article prepared above was left for 7 days, and the bleed on the surface of the molded article was visually evaluated. The evaluation criteria are as shown in Table 1 below.

[0045]

[Table 1] O: No bleeding. Δ: It is difficult to see, but some stickiness or whitening is observed. X: Stickiness or whitening is observed.

Examples 1 to 3 and Comparative Examples 1 to 5 The components shown in Table 2 were blended in the proportions shown in the table and blended for 1 minute with a Henschel mixer. "Parts by weight" in Table 2 is the ratio per 100 parts by weight of the components A1 and A2 in total. After that, the same-direction twin-screw extruder (Kobe Steel “K
TX44 ”, L / D = 41, number of cylinder blocks = 1
It was charged into the first supply port of 1) at a rate of 40 kg / h, melt-kneaded, and pelletized. The evaluation results are shown in Table 2.

[0047]

[Table 2]

[0048]

EFFECT OF THE INVENTION According to the present invention described above, a thermoplastic elastomer composition for extrusion molding is provided, in which the generation of mesiness during extrusion molding is reduced by blending a specific material.
The industrial value of the present invention is great.

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Claims (3)

[Claims] 1. A melting point of 125 ° C. per 100 parts by weight of a completely or partially crosslinked olefinic elastomer (A).
A thermoplastic elastomer composition for extrusion molding, comprising 0.05 to 5 parts by weight of the above fatty acid amide (B). 2. A melting point of 125 ° C. per 100 parts by weight of a completely or partially crosslinked olefinic elastomer (A).
The thermoplastic elastomer composition for extrusion molding according to claim 1, which comprises 0.01 to 3 parts by weight of a fatty acid amide (C) of less than 1. 3. The extrusion molding according to claim 1, wherein 0.05 to 10 parts by weight of the organopolysiloxane (D) is mixed with 100 parts by weight of the completely or partially crosslinked olefinic elastomer (A). Thermoplastic elastomer composition.