JPH06128414A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic elastomer composition having excellent flexibility, heat resistance, oil resistance, moldability and processability and mechanical strength by blending a thermoplastic polyester elastomer with a specific hydrogenated rubber. CONSTITUTION:A thermoplastic elastomer composition comprises (A) 40-99wt.% thermoplastic polyester elastomer, preferably having a ratio of a high-melting crystalline segment composed of an aromatic polyester and a low-melting polymer segment composed of an aliphatic polyether and/or an aliphatic polyester of 95/5-5/95 by weight, having >=100 deg.C softening point and (B) 60-1wt.%, rubber selected from B1: hydrogenated material of acrylonitrile-butadiene rubber having >=80%, preferably >=90% hydrogenation rate and 20-30%, preferably 30-45% acrylonitrile content and B2: rubber composed of a hydrogenated material of a random copolymer of acrylic acid (alkoxy-substituted) alkyl ester and a conjugated diene, having preferably <=50mum average particle diameter.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition having improved flexibility without impairing the excellent heat resistance and oil resistance of the polyester elastomer.

[0002]

2. Description of the Related Art Thermoplastic polyester elastomers are
It is a multi-block copolymer having polyester and polyether repeating units, or polyester and polyester in the polymer main chain, and is excellent in mechanical properties, heat resistance and oil resistance.

However, the thermoplastic polyester elastomer has drawbacks such as high hardness and poor flexibility as an elastomer, and expansion of its application is restricted.

As a method of improving this drawback and making it a flexible material, a method of blending a polystyrene type block copolymer with a polyester elastomer to soften it (Japanese Patent Laid-Open No.
82162) or a method of blending an ethylene copolymer with a polyester elastomer to soften it (JP-A-60-7).
No. 662) has been proposed.

However, the flexibility of the polyester elastomer obtained by these methods is not yet sufficient, and there is a drawback that the oil resistance and heat resistance of the obtained composition are lowered.

[0006]

As described above, since thermoplastic polyester elastomers are excellent in mechanical properties, oil resistance, heat resistance, molding processability, etc., their applications are desired to be expanded. Has the drawback of lacking.

[0007]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in view of the above-mentioned points, the blending of a specific hydrogenated rubber (B) with a polyester elastomer (A) results in excellent flexibility and It was found that a thermoplastic elastomer composition in which oil resistance and heat resistance are not deteriorated can be obtained,
The present invention has been completed based on this finding.

That is, the present invention comprises (A) 40 to 99% by weight of a thermoplastic polyester elastomer, and (B) at least one selected from a hydrogenated product of acrylonitrile butadiene rubber and a hydrogenated product of acrylic ester butadiene rubber. A thermoplastic elastomer composition comprising 60 to 1% by weight of rubber is provided.

The thermoplastic polyester elastomer which is the component (A) of the present invention is a polyester block copolymer, and a high melting point crystalline segment (A-1) mainly composed of an aromatic polyester unit in its polymer chain.
And a low melting point polymer segment (A-2) mainly composed of an aliphatic polyether unit (a) and / or an aliphatic polyester unit (b).

The aromatic polyester unit of the high melting point crystalline segment (A-1) which is a hard segment is formed from an acid component and a glycol component, and the acid component is substantially terephthalic acid and / or 2, It is 6-naphthalenedicarboxylic acid. In addition to terephthalic acid or 2,6-naphthalenedicarboxylic acid, other aromatic dicarboxylic acids such as isophthalic acid, or aliphatic dicarboxylic acids such as adipic acid, sebacic acid, cyclohexane-1,4-dicarboxylic acid and dimer acid. May be used together in a small amount. The glycol component forming the aromatic polyester unit is a glycol having 2 to 12 carbon atoms, such as ethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexanediol, decanediol. The lower limit of the melting point of the high melting point crystalline segment (A-1) is not particularly limited, but is generally preferably 150 ° C. or higher.

The aliphatic polyether unit (a) constituting the low melting point polymer segment (A-2) which is a soft segment is formed of polyalkylene glycol having an average molecular weight in the range of about 400 to 600, The polyalkylene glycol is, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or polyethylene glycol-polypropylene glycol block copolymer, and polytetramethylene glycol is particularly preferable. These can be used alone as a mixture as long as the carbon number: oxygen number ratio is 2.0 to 4.5.

The aliphatic polyester unit (b) which is another unit constituting the low melting point polymer segment (A-2) is mainly composed of an aliphatic dicarboxylic acid and glycol, and the aliphatic acid unit which is the main acidic component thereof. The dicarboxylic acid is, for example, succinic acid, adipic acid, sebacic acid, decanedicarboxylic acid. In addition to these aliphatic dicarboxylic acids, a small amount of aromatic dicarboxylic acids such as isophthalic acid may be used together. The glycol component forming the aliphatic polyester unit (b) is a glycol component having 2 to 12 carbon atoms and has a high melting point crystalline segment (A-
It is the same as the one exemplified as the glycol component forming the aromatic polyester unit of 1).

The aliphatic polyester unit (b) is obtained by polycondensing the above aliphatic dicarboxylic acid and a glycol component by a usual method, and may be a homopolyester or a copolyester, or a cyclic lactone. Polylactone obtained by ring-opening polymerization (for example, poly-
ε-caprolactone). The upper limit of the melting point is not particularly limited, but generally 130 ° C. or lower,
Particularly preferably, it is 100 ° C. or lower.

Thermoplastic polyester elastomer (A)
The composition ratio of the high melting point crystalline segment (A-1) and the low melting point polymer segment (A-2) in the medium is preferably 95/5 to 5/95 by weight, and more preferably 70 /
30 to 30/70. Further, as the thermoplastic polyester elastomer (A), an elastomer having a softening point of 100 ° C. or higher is particularly suitable.

Thermoplastic polyester elastomer (A)
The polyester block copolymer particularly preferably used as the high melting point crystalline segment (A-1) is polytetramethylene terephthalate or polytrimethylene terephthalate-2,6-naphthalate, and the low melting point polymer segment (A-2) is used. ) As polytetramethylene glycol, polytetramethylene adipate, poly-
It is formed using an aliphatic polyester such as ε-caprolactone. In addition, a polycarboxylic acid, a polyfunctional hydroxy compound, an oxy acid or the like may be copolymerized as a part of the dicarboxylic acid or glycol. When the polyfunctional component is copolymerized in the range of 3 mol% or less, it effectively acts as a viscosity increasing component. Examples of the polyfunctional component include trimellitic acid, trimesic acid, pyromellitic acid, benzophenonetetracarboxylic acid, butanetetracarboxylic acid, glycerin, pentaerythritol, their esters, and acid anhydrides.

The component (B) of the present invention is at least one rubber selected from hydrogenated acrylonitrile butadiene rubber and hydrogenated acrylic ester butadiene rubber.

The hydrogenated product of the acrylonitrile-butadiene rubber is a rubber obtained by hydrogenating 80% or more, preferably 90% or more of the double bonds of the conjugated diene polymerized units of the random copolymer composed of acrylonitrile and butadiene. The proportion of acrylonitrile in the random copolymer is usually 20 to 30% by weight, preferably 30 to 45% by weight.

Further, the hydrogenated product of the acrylic ester butadiene rubber is 80% or more of the double bonds of the conjugated diene polymerized units of the random copolymer composed of the acrylic acid alkyl ester or the acrylic acid alkoxy-substituted alkyl ester and the conjugated diene. The rubber is preferably 90% or more hydrogenated rubber. Here, as the acrylic acid alkyl ester, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-methylpentyl acrylate, n -Octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate, n-octadecyl acrylate, etc. are preferable, and methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate are preferable, and particularly preferable. Are methyl acrylate and ethyl acrylate. Moreover, as the acrylic acid alkoxy-substituted alkyl ester, for example, 2-methoxyethyl acrylate, 2
-Ethoxyethyl acrylate, 2- (n-propoxy) ethyl acrylate, 2- (n-butoxy) ethyl acrylate, 3-methoxypropyl acrylate, 3
-Ethoxypropyl acrylate, 2- (n-propoxy) propyl acrylate, 2- (n-butoxy) propyl acrylate and the like are mentioned, preferably 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate, particularly preferably 2- It is methoxyethyl acrylate.

The amounts of the component (A) and the component (B) used in the present invention are (A) component / (B) component = 40 to 99/60.
˜1% by weight, preferably 50-90 / 50-10
% By weight, more preferably 60-80 / 40-2
It is 0% by weight. In the region where the amount of the component (A) used exceeds 99% by weight (the amount of the component (B) is less than 1% by weight), the effect of improving the flexibility of the resulting composition is not recognized. Also (A)
Area where the amount of the component used is less than 40% by weight ((B) component is 6
If it exceeds 0% by weight), the processability and fluidity of the resulting composition are poor.

The component (B) of the present invention must be dispersed and mixed in the component (A), and the average particle size thereof is 50.
μm or less is preferable, more preferably 10 μm or less,
Particularly preferably, it is 5 to 0.01 μm.

In the present specification, "average particle size"
Is a value obtained by measuring 100 or more rubber particles in a random visual field observed with an electron microscope and averaging the particle diameters. For non-spherical particles, the diameter when the circular area was measured was measured.

A plasticizer may be added to the thermoplastic elastomer composition of the present invention in order to further improve flexibility and fluidity within a range that does not impair mechanical strength and the like.

The plasticizer used is a process oil or a softening agent for mineral oil rubber called extension oil, dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate,
Phthalates such as di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, diisononyl phthalate, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethyl phosphate, tributoxyethyl phosphate, tris -Chloroethyl phosphate, tris-dichloropropyl phosphate, condensed phosphoric acid ester, triphenyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, trilauryl phosphate, tricetyl phosphate, Phosphoric acid such as tristearyl phosphate and trioleyl phosphate Sterimes, trimellitic acid octyl ester, trimellitic acid isononyl ester, trimellitic acid isodecyl ester, and other trimellitic acid esters, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl adipate, diisobutyl Fatty acid esters such as adipate, dibutyl adipate, diisodecyl adipate, dibutyl diglycol adipate, di-2-ethylhexyl azelate, dioctyl azelate, dioctyl sebacate, di-2-ethylhexyl sebacate, methyl acetylricinoleate, pyromellitic acid Pyromellitic acid esters such as octyl ester, epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid alkyl ester (for example, epoxidized fat Acid octyl ester) and other epoxy plasticizers, adipic acid ether ester, polyether ester, polyether and other polyether plasticizers. These plasticizers may be used alone or in combination of two or more. it can.

When the above-mentioned plasticizer is added to the composition of the present invention, phthalic acid esters, phosphoric acid esters, epoxy plasticizers, polyether plasticizers and the like are preferable from the viewpoint of bleeding property, and more preferably. Phthalates and polyether plasticizers.

The thermoplastic elastomer composition of the present invention contains fillers such as calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth and mica powder as long as the fluidity and mechanical strength are not impaired. ,
Asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, carbon black, carbon fiber, etc., or colorants such as carbon black, ultramarine blue, titanium oxide, zinc white, red iron oxide, dark blue , Azo pigments, nitrone pigments, lake pigments, phthalocyanine pigments and the like can be added.

Further, a hindered phenol antioxidant, a benzotriazole ultraviolet absorber, a hindered amine ultraviolet stabilizer and the like can be added during mixing.

The thermoplastic elastomer composition of the present invention includes polypropylene, polyvinyl chloride, polycarbonate, PET, PBT, polyacetal, polyamide, epoxy resin, vinylidene fluoride, polysulfone,
Ethylene-vinyl acetate copolymer, PPS resin, polyether ether ketone, PPO resin, styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer, rubber-modified PPO resin, styrene-maleimide copolymer, A resin such as a rubber-modified styrene-maleimide copolymer, an elastomer other than a polyester elastomer (for example, a polyamide elastomer), a thermoplastic elastomer, or the like can be appropriately blended.

Molded articles of the composition of the present invention include bumper parts, side shields, steering wheels, moldings,
Automotive parts such as handles, shoe soles, footwear such as sandals, electric wire coatings, connectors, electrical parts such as cap plugs, golf club grips, baseball bat grips,
Swimming fins, sports such as underwater glasses, leisure products, rubber contacts such as keyboard switches, curl cords, couplings, O-rings, gaskets, waterproof cloths, hydraulic hoses, power hose hoses, vacuum tubes, garden hoses such as coil tubes, etc. It can be used as a material for tubes, hoses, packing rolls, belts, etc.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In the following examples, "parts" means "parts by weight" and "%" means "% by weight" unless otherwise specified.

Example 1 A hydrogenated product of a polyether ester elastomer (PIBIFLEX 46M manufactured by Montedippe Co.) and acrylonitrile butadiene rubber (Terban 190 manufactured by Bayer Co.).
7) was kneaded in a ratio shown in Table 1 at 210 ° C. using a twin-screw extruder.

The pellets obtained were thoroughly dried and then 2
Molded into a 2mm thick sheet with an injection molding machine at 10 ° C,
The performance was evaluated. The results are shown in Table 1.

The test methods used for each evaluation are as follows. (1) Hardness: JIS K-6301 JIS A hardness (2) Fluidity: MFR230 ° C × 2.16 kg (3) Tensile strength: JIS K-6301 JIS No. 3 dumbbell (4) Tensile elongation: JIS K-6301 JIS No. 3 Dumbbell (5) Heat aging resistance: JIS K-6301 Measure the change in tensile strength after 70 hours at 120 ° C. using a Gar type aging tester (6) Oil resistance: JIS K-6301 JIS No. 70 in 70 oil Measure the change in tensile strength after soaking at ℃ for 22 hours

Example 2 Pellets were produced in the same manner as in Example 1 except that the hydrogenated product of an acrylic ester butadiene rubber (B-1) shown below was used as the rubber. The performance of the obtained pellets was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Production of hydrogenated product (B-1) of acrylate butadiene rubber: methyl acrylate 50 parts, 1,3
-Butadiene 50 parts, water 200 parts, sodium lauryl sulfate 3 parts, p-menthane hydroperoxide 0.2
Parts, sodium ethylenediaminetetraacetate 0.125 parts,
0.05 parts of ferrous sulfate, 0.2 parts of sodium formaldehyde sulfoxylate, and 0.2 parts of t-dodecyl mercaptan were placed in an iron container in which the atmosphere was replaced with nitrogen, and the contents were adjusted to 1 at 10 ° C.
It was polymerized for 10 hours.

After the polymerization, the reaction product was taken out and steam was blown into it to remove unreacted monomers. The latex of the copolymer rubber thus obtained was coagulated by adding an aqueous calcium chloride solution, and the coagulated product was thoroughly washed with water and dried at about 90 ° C. for 1 to 3 hours to obtain a copolymer rubber. .

10 parts of the obtained copolymer rubber was mixed with 9 parts of toluene.
After being dissolved in 0 part, the solution was placed in a pressure resistant container, and 0.5 part of nickel naphthenate and 0.15 part of triethylaluminum were used as a solvent under hydrogen pressure (40 kg / cm ² · G) at a temperature of 6
A hydrogenated copolymer rubber was obtained by hydrogenating the carbon-carbon double bond of the conjugated diene polymerized units of the rubber in the copolymer at 0 ° C for 1 to 5 hours. The obtained hydrogenated copolymer rubber had a polystyrene equivalent weight average molecular weight of 1,230,000 and a hydrogenation rate of 96%.

Comparative Example 1 Other than changing the compounding ratio of the polyether ester elastomer and the hydrogenated product of acrylonitrile butadiene rubber,
Pellets were obtained in the same manner as in Example 1, and the performance was evaluated by the same method as in Example 1. The results are shown in Table 1.

Comparative Examples 2 to 4 Instead of hydrogenated acrylonitrile butadiene rubber,
Styrenic block copolymer (TR made by Japan Synthetic Rubber Co., Ltd.
2000) or EPM (JSR manufactured by Japan Synthetic Rubber Co., Ltd.)
Pellets were obtained in the same manner as in Example 1 except that EP02P) was used, and the performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0039]

[Table 1]

As is clear from the results shown in Table 1, in Examples 1 and 2, compositions satisfying all physical properties such as hardness, fluidity, tensile strength, tensile elongation, heat aging resistance and oil resistance were obtained. ing.

On the other hand, the composition of Comparative Example 1 is (B)
This is an example in which the blending ratio of the components is higher than the range of the present invention, and it cannot be said that it is any more thermoplastic and molding cannot be performed.

The compositions of Comparative Examples 2 to 4 are examples using the component (B) outside the range of the present invention, and are inferior in heat aging resistance and oil resistance.

[0043]

INDUSTRIAL APPLICABILITY The thermoplastic elastomer composition of the present invention is excellent in flexibility, heat resistance and oil resistance, as well as in moldability and mechanical strength, and cannot be used in conventional thermoplastic elastomers. It can be used as a molding material for new applications, and its industrial value is extremely large.

Claims (1)

[Claims] 1. A thermoplastic polyester elastomer (A) 40 to 99% by weight and at least one rubber (B) acrylonitrile butadiene rubber hydrogenated product and acrylic ester butadiene rubber hydrogenated product 60 to
A thermoplastic elastomer composition comprising 1% by weight.