JP2001253980A - Urethane-based elastomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer excellent in flexibility, weather resistance, heat resistance, low temperature characteristics, strength and molding processability, and an elastomer member consisting of the above composition, not requiring surface coating and excellent in scratch resistance. SOLUTION: This thermoplastic elastomer composition consists of the following (A), (B) and (C). (A) 100 pts.wt. polyurethane elastomer. (B) 10-900 pt.wt. polypropylene mixture of (B-1) 10-60 wt.% homopolymer or copolymer of polypropylene, (B-2) 40-90 wt.% ethylene-propylene (-&alpha;-olefin) copolymer (provided that it has <=2 &mu;m mean dispersed particle diameter of ethylene-propylene- based copolymer rubber in the above mixture and the above mixture has specific bending modulus, Shore D hardness and melt flow rate). (C) 3-100 pt.wt. modified polymer having carboxylic acid group, epoxy group or the like in its molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to various molded articles having excellent scratch resistance (scratch resistance) on the surface of molded articles, and excellent flexibility, heat resistance, low-temperature properties, weather resistance, strength, and moldability. The present invention relates to a thermoplastic elastomer composition that can be used as a material.

[0002]

2. Description of the Related Art Thermoplastic elastomers having excellent productivity have been increasingly used for automotive parts, home electric parts, medical parts and miscellaneous goods, for which vulcanized rubber has hitherto been mainly used. Examples thereof include olefin-based elastomers composed of an ethylene-propylene copolymer and polypropylene, polyurethane elastomers, and soft polyvinyl chloride.

However, at present, these molding materials have drawbacks in terms of scratch resistance, flexibility, workability, economy, and recyclability. That is, olefin-based elastomers are relatively inexpensive and have excellent weather resistance and heat resistance, but are inferior in flexibility and scratch resistance. Polyurethane elastomers have excellent scratch resistance, but have the disadvantage that they have a large specific gravity and are expensive. Soft vinyl chloride is relatively inexpensive and has excellent weather resistance and scratch resistance, but has the drawback of poor flexibility at low temperatures and poor recyclability.

Some proposals have also been made for elastomer compositions using hydrogenated derivatives of vinyl aromatic compound-conjugated diene compound block copolymers (hereinafter abbreviated as hydrogenated block copolymers). . For example, JP-A-50-14742, JP-A-52-65551,
JP-A-58-206644 discloses compositions in which a hydrogenated block copolymer is blended with a rubber softener and an olefin resin. However, these compositions, like the olefin-based elastomers, also had poor scratch resistance.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems, and a thermoplastic elastomer having excellent flexibility, weather resistance, heat resistance, low-temperature properties, strength, and moldability. Another object of the present invention is to provide an inexpensive elastomer member having excellent scratch resistance which does not require coating of the surface of the composition.

[0006]

That is, the present invention relates to a thermoplastic elastomer composition comprising the following components (A), (B) and (C). (A) polyurethane elastomer: 100 parts by weight (B) (B-1) a homopolymer of polypropylene or a copolymer of propylene and an α-olefin (containing 85% by weight or more of propylene) or an ethylene-propylene copolymer ( (Contains 85% by weight or more of propylene): 10 to 60% by weight (B-2) Ethylene-propylene copolymer (containing 75% by weight or less of propylene) or ethylene-propylene-
α-olefin copolymer (containing 75% by weight or less of propylene): a mixture of 40 to 90% by weight, wherein the average dispersed particle size of the ethylene-propylene-based copolymer rubber in the mixture is 2 μm or less; Has a flexural modulus of 20 to 700 MPa and a Shore D hardness of 2
0 to 60, a polypropylene mixture having a melt flow rate of 10 to 60 g / 10 min: 10 to 900 parts by weight (C) a modified polymer having a carboxylic acid group or its derivative group, or an epoxy group or its derivative group in the molecule: 3 to 100 parts by weight

Hereinafter, the present invention will be described in detail. The polyurethane elastomer (hereinafter abbreviated as TPU) as the component (A) of the present invention is classified according to the linear polyol used, and includes polyester (caprolactone, adipate), polycarbonate, and polyether types. Both can be used. Of these, polycarbonates having high mechanical strength and a good balance of heat aging resistance and hydrolysis resistance are desirable.

The polycarbonate-based polyurethane elastomers have a Shore D hardness of 20 to 70 obtained by copolymerizing the following components (a) and (b) and, if necessary, component (c).
Are preferred.

(A) A polycarbonate diol comprising a repeating unit represented by the following formula (1) and having a terminal group of a hydroxyl group (wherein R represents an aliphatic or alicyclic hydrocarbon group having 2 to 10 carbon atoms) .

[0010]

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(B) Polyisocyanate (c) Chain extender having two active hydrogens capable of reacting with polyisocyanate

The polycarbonate diol used as the component (a) of the polyurethane elastomer of the present invention comprises:
Schell, Polymer Review No. 9
, Pages 9-20 (1964), from aliphatic and / or cycloaliphatic diols. Preferred diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 2,3 -Butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like.

In order to obtain an elastomer having a good balance of hydrolysis resistance (sweat resistance), weather resistance and softness,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol is preferred.

Particularly preferred polycarbonate diols are 1,4-butanediol and / or 1,5-butanediol.
A copolymerized polycarbonate diol synthesized from pentanediol and 1,6-hexanediol is preferred because the resulting thermoplastic elastomer composition has excellent low-temperature properties and rebound resilience. A repeating unit in the polymer,
The ratio of 1,4-butanediol and / or 1,5-pentanediol to 1,6-hexanediol is 1
0/90 to 90/10, preferably 20/80 to 80
/ 20, more preferably 30/70 to 70/30.

The average molecular weight of the polycarbonate diol used in the present invention is usually in the range of number average molecular weight of 500.
~ 5000, preferably 1000 ~ 3000,
More preferably, those having a molecular weight of 1500 to 2500 are used, and it is desirable that the terminal of the polymer is substantially all hydroxyl groups.

In the present invention, in addition to the above-mentioned diols, compounds having three or more hydroxyl groups in one molecule, such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol,
Polyurethane using a polycarbonate which has been polyfunctionalized by using a small amount such as the above is also included.

Next, as the polyisocyanate used as the component (b) of the polyurethane elastomer of the present invention, for example, 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate and mixtures thereof (TD
I), diphenylmethane-4,4′-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3′-dimethyl-4,4′-biphenylene diisocyanate, crude TDI, polymethylene polyphenylisocyanate, Known aromatic diisocyanates such as crude MDI; xylylene diisocyanate (XD
I), known aromatic alicyclic diisocyanates such as phenylene diisocyanate; 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI) Known aliphatic diisocyanates, such as
And modified isocyanurates, carbodiimidations and biurets of these isocyanates.

Suitable chain extenders used as necessary as the copolymer component (c) of the polyurethane elastomer of the present invention include those commonly used in the polyurethane industry. Supervised by Keiji Iwata Recent polyurethane application technology CMC 1985, pp. 25-27, including known water, low molecular polyol, polyamine and the like.
A known polyol may be used in combination with the aliphatic polycarbonate used in the present invention, depending on the use of the polyurethane, as long as the effects of the present invention are not impaired. Known polyols include known polyols such as polyester and polyether carbonate described in Yoshio Imai, Polyurethane Form Polymer Publishing Association, 1987, pp. 12-23.

Specifically, a diol having a molecular weight of 300 or less is usually used as the low-molecular polyol. For example, aliphatic diols such as ethylene glycol, 1,3-propylene diol, 1,4-butane diol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol and the like can be mentioned.

Also, alicyclic diols such as 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and tricyclodecanedimethanol, xylylene glycol, bis (p-hydroxy) diphenyl, bis (p-hydroxy Phenyl) propane, 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4 (2-hydroxy) phenyl] sulfone,
1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane and the like. Preferably, ethylene glycol and 1,4-butanediol are used.

As a method for producing the polyurethane elastomer of the present invention, a urethane-forming reaction technique known in the polyurethane industry is used. For example, an NCO-terminated polyurethane prepolymer is produced by reacting the polyol with an organic polyisocyanate at room temperature to 200 ° C.

A thermoplastic polyurethane elastomer can be produced using the polyol, polyisocyanate and, if necessary, a chain extender. In the production of these, known polymerization catalysts represented by organic metal salts such as tertiary amines, tin, and titanium are described, for example, by Keiji Yoshida (polyurethane resin), published by Nihon Kogyo Shimbun, pp. 23-32 (1).
969) can be used. These reactions may be carried out using a solvent, and preferred solvents include dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, methylisobutylketone, dioxane, cyclohexanone, benzene, toluene, and ethylcellosolve. is there.

In producing the polyurethane elastomer of the present invention, a compound containing only one active hydrogen which reacts with an isocyanate group, for example, a monohydric alcohol such as ethyl alcohol and propyl alcohol, and a compound such as diethylamine and di-n-propylamine Secondary amines and the like can be used as terminal terminators.

The polyurethane elastomer using the polycarbonate diol of the present invention is not only excellent in flexibility and elastic recovery but also extremely good in hydrolyzability as compared with other polyurethane elastomers. When used as a member, it is suitable because of its excellent sweat resistance.

The polypropylene mixture as the component (B) of the present invention is, for example, a propylene copolymer mixture obtained by sequential polymerization of at least two stages. In the first step, a propylene homopolymer or propylene and α-
The component (B-1) is produced by polymerizing an olefin copolymer (containing 85% by weight or more of propylene) or an ethylene propylene copolymer (containing 85% by weight or more of propylene). Propylene (contains 75% by weight or less of propylene) or ethylene-propylene-α-olefin (may contain a small amount of diene)
The copolymer (containing 75% by weight or less of propylene) is polymerized to produce the component (B-2).

In the polymerization of propylene in the first step, the obtained polypropylene has an isotactic index of 80% or more,
Preferably an amount of at least 85%, more preferably at least 90%, of ethylene or α-olefin, such as butene-1, pentene-1,4-methyl-pentene-
It can be performed in the presence of 1, hexene-1, and octene-1 or a combination thereof.

The monomers used to polymerize the ethylene-propylene copolymer or ethylene-propylene-α-olefin copolymer after the second step are propylene and ethylene and / or α-olefin (for example, butene-
1, pentene-1, 4-methyl-pentene-1, hexene-1, and octene-1 or a combination thereof). The polymerization of the copolymer after the second step is carried out by conjugated or non-conjugated dienes, for example, butadiene, 1,4-
It can be carried out in the presence of hexadiene, 1,5-hexadiene, and ethylene-norbornene-1. The diene, when present, is typically from 0.5 to 10% by weight, based on the weight of all monomers used in the second and subsequent steps.

The amount of component (B-1) in the polypropylene composition of component (B) is from 10 to 60% by weight, preferably from 15 to 60% by weight.
50% by weight, the amount of (B-2) is 40 to 90% by weight, preferably 50 to 85% by weight.

The total amount of ethylene copolymerized in the polypropylene mixture of the component (B) is 15 to 60% by weight, preferably 17 to 45% by weight, more preferably 20 to 3% by weight.
5% by weight. The amount of all α-olefins copolymerized in the polypropylene mixture (B) is 0 to 30% by weight, preferably 3 to 20% by weight, more preferably 5 to 5% by weight.
10% by weight.

The mixture (B) was subjected to differential scanning calorimetry (D
SC) shows at least one melting peak present at a temperature above 120 ° C., preferably above 140 ° C. Further, the mixture (B) has a flexural modulus of 20 to 700 MPa, preferably 50 to 300 MPa.
Mpa, more preferably 70-200 MPa. The mixture (B) has a Shore D hardness of 20 to 60,
Preferably it is 30-50.

The melt flow rate of the mixture (B) (ASTM D1238, measured at 230 ° C. under a load of 2.16 kg; hereinafter abbreviated as MFR) is 10 to 10.
60 g / 10 min, preferably 12 to 50 g / 10 min, more preferably 15 to 40 g / 10 min. If the MFR is less than 10 g / 10 minutes, the melt viscosity of the elastomer composition is high, and the moldability (flowability) of the elastomer composition is lowered, and the appearance of a molded product is deteriorated (the generation of flow marks). Further, the MFR is 10 g / 10
If the amount is less than minutes, the scratch resistance of the elastomer composition also decreases, which is not preferable. On the other hand, the MFR is 60 g / 10
If the amount exceeds minutes, the strength and heat resistance of the elastomer composition are undesirably reduced.

The average particle size of the ethylene-propylene copolymer rubber dispersed in the mixture (B) is 2 μm or less.
Preferably it is 1.5 μm or less. If the average dispersed particle size of the rubber exceeds 2 μm, the scratch resistance of the elastomer composition is extremely lowered, which is not preferable.

The catalyst used for the polymerization of the polypropylene mixture of component (B) is a Ziegler-Natta type catalyst.
Preferred catalysts are reaction products of a solid catalyst component containing a titanium compound and an electron donor compound (internal donor) supported on magnesium chloride with a trialkylaluminum compound and an electron donor compound (external donor). . As a method for preparing the catalyst and a method for polymerizing the component (B),
For example, JP-A-3-205439 and JP-A-6-2
No. 5367, JP-A-6-25489 and the like.

The blending amount of the polypropylene mixture of the component (B) in the thermoplastic elastomer composition of the present invention is TPU
10 to 900 parts by weight, based on 100 parts by weight of component (a),
Preferably 20 to 500 parts by weight, more preferably 30 parts by weight.
２００200 parts by weight. If the amount of the polypropylene mixture of the component (B) exceeds 900 parts by weight, the rubber elasticity decreases and the low-temperature characteristics deteriorate, which is not preferable. Also,
If the blending amount of the polypropylene mixture of the component (B) is less than 10 parts by weight, the hydrolysis resistance and the molded appearance of the thermoplastic elastomer composition are deteriorated (flow marks are generated), and the specific gravity is high.

The polypropylene mixture of the component (B) used in the present invention includes Adflex, Hifax
(Manufactured by Montell, Catalloy TPO series) or the like.

Next, the modified polymer as the component (C) of the present invention is effective as a compatibilizer for compatibilizing the polyester elastomer as the component (A) and the polypropylene mixture as the component (B). To improve the dispersibility of each component of the obtained thermoplastic elastomer composition.
As a result, not only the scratch resistance of the obtained thermoplastic elastomer and the appearance of the molded product can be improved, but also a molded product without peeling can be obtained.

The modified polymer used as the component (C) in the present invention is a polymer in which a molecular unit containing a carboxylic acid group or a derivative thereof, or an epoxy group or a derivative thereof is bonded to various polymers. Examples of various polymers used as the component (C) include polyolefin resins such as polyethylene, polypropylene, and polybutene;
Polystyrene, styrene-acrylonitrile copolymer,
A styrene-based resin such as a styrene-acrylonitrile-diene copolymer can be used. Also preferably, polybutadiene, polyisoprene, diene elastomers such as random copolymers of polybutadiene and polystyrene and hydrogenated products thereof; ethylene-propylene copolymer, ethylene-propylene / 5-ethylidene norbornene copolymer, Olefinic elastomers such as ethylene / propylene / 5-methylnorbornene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / butene copolymer, ethylene / octene copolymer; styrene / butadiene block copolymer Styrene-based elastomers such as ethylene, styrene-isoprene block copolymers and hydrogenated products thereof; ethylene such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer When Elastomers and copolymers of machine acid esters are used. Among these elastomers, hydrogenated styrene / butadiene block copolymers and hydrogenated styrene / isoprene block copolymers are particularly preferred because the resulting elastomer composition is excellent in moldability and scratch resistance.

Examples of compounds containing a carboxylic acid group or a derivative thereof bonded to the modified polymer include maleic acid, maleic ester, maleic amide, maleic imide, maleic anhydride, fumaric acid, fumaric ester, and the like. Fumaric acid amide, fumaric acid imide, phthalic acid, itaconic acid, itaconic anhydride, itaconic acid ester, itaconic acid amide, itaconic imide, halogenated maleic acid, halogenated maleic acid ester, halogenated maleic acid amide, halogenated maleic acid Acid imide, acrylic acid, crotonic acid, methacrylic acid, cis-4-cyclohexane-1,2-dicarboxylic acid, its ester, its anhydride, its amide, and its imide, endo-cis-bicyclo (2,2,1 ) -5-Heptene-2,3-dicarboxylic acid, its ester , Its anhydrides, its amides and its imides: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, glycidyl (meth) acrylate, (meth) Acrylic amide and the like can be mentioned. Of these, maleic anhydride is particularly preferred.

The modified polymer having an epoxy group in the molecule is not particularly limited, and is a copolymer of ethylene and glycidyl methacrylate, or a tertiary copolymer of ethylene / methacrylic acid copolymer and glycidyl methacrylate. Coalescence and the like are exemplified. Further, a styrene-based block copolymer containing an epoxy group can also be used. Examples of the epoxidized styrene-based block copolymer include an epoxidized styrene-butadiene block copolymer, an epoxidized styrene-isoprene block copolymer, an epoxidized hydrogenated styrene-butadiene block copolymer, and an epoxidized hydrogenated styrene. -Isoprene block copolymer and the like. The epoxidized styrene-based block copolymer of the present invention is obtained by adding a block copolymer to an epoxy compound having an unsaturated double bond such as glycidyl methacrylate or reacting a residual unsaturated bond with peracetic acid or the like. It can be obtained by:

The content of the compound containing a carboxylic acid group or a derivative thereof, or an epoxy group or a derivative thereof in the polymer is 0.1 to 20 parts by weight based on 100 parts by weight of the unmodified polymer. , Preferably 0.
It is 3 to 10 parts by weight, more preferably 0.5 to 5 parts by weight. By using the component (C) in which a carboxylic acid group or a derivative group thereof, or an epoxy group or a derivative group thereof is introduced into a hydrogenated block copolymer, the compatibility between the component (A) and the component (B) of the present invention is improved. Is significantly improved, but if the content of the carboxylic acid group or its derivative group, or the epoxy group or its derivative group is too large, the fluidity of the composition is lowered, and a problem arises that molding processability is deteriorated. On the other hand, if the content of the carboxylic acid group or its derivative group, or the epoxy group or its derivative group is too small, the effect of improving the compatibility between the component (A) and the component (B) of the present invention becomes insufficient. . For this reason, the above-mentioned additional amount is desirable.

The amount of the component (C) used in the present invention is 3 to 100 parts by weight, preferably 5 to 50 parts by weight, and more preferably 8 to 100 parts by weight based on 100 parts by weight of the component (A) of the present invention.
30 parts by weight. When the amount of the component (C) is less than 3 parts by weight, the effect of improving the compatibility is not sufficient, and a composition having excellent scratch resistance and appearance cannot be obtained. Also, 100
Even when used in a large amount in excess of parts by weight, the compatibility effect reaches a peak and the fluidity is rather remarkably reduced, and the composition does not have excellent scratch resistance and appearance.

As a method for producing the modified polymer as the component (C), a compound containing a carboxylic acid group or a derivative group thereof, or an epoxy group or a derivative group thereof and a commonly used radical initiator are allowed to coexist. It is obtained by radical addition to a polymer. The method for producing these modified polymers is not particularly limited in the present invention. However, the resulting modified polymers contain undesirable components such as gels, and their melt viscosities are significantly increased, resulting in extremely poor processability. Is not preferred.

A preferred production method is to react an unmodified polymer with a carboxylic acid group or a derivative thereof, or an epoxy group or a derivative thereof in the presence of an inert gas in an extruder, for example, in the presence of a radical initiator. There is a way to make it happen. Further, a method is also used in which an unmodified polymer is dissolved in a solvent such as toluene or xylene and reacted with a carboxylic acid group or a derivative group thereof, or an epoxy group or a derivative group thereof in the presence of a radical initiator. Unreacted carboxylic acid or its derivative, or epoxy or its derivative is preferably removed by an appropriate post-treatment such as vacuum degassing, extraction, or precipitation.

Further, the elastomer composition of the present invention includes:
If necessary, a polyolefin-based resin can be added. Specific examples of polyolefin resins that can be added include polyethylene resins and polypropylene resins. Examples of the polyethylene resin include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms. In the case of a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms, the α-olefin in the copolymer may be propylene, butene-1, isobutene, pentene-
1, hexene-1, 4-methylpentene-1, octene-1 and the like. The ratio of α-olefin is 3
What is 0% by weight or less is used.

The polypropylene resin is a propylene homopolymer or a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms (hereinafter abbreviated as propylene resin). In the case of a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, the α-olefin in the copolymer may be ethylene, butene-1, isobutene, pentene-
1, hexene-1, 4-methylpentene-1, octene-1 and the like. The ratio of α-olefin is 3
What is 0% by weight or less is used. These propylene-based resins can be synthesized by a conventionally known method, for example, a propylene homopolymer synthesized using a Ziegler-Natta type catalyst, or a copolymer of random or block propylene and an α-olefin. Is raised.

As additives used in the present invention, it is desirable to use at least an antioxidant, a light stabilizer and a heat stabilizer. Examples of these antioxidants include aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid and phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diacids. Phosphite,
Phosphorus compounds such as dialkylbisphenol A diphosphite; phenol derivatives, especially compounds containing sulfur such as hindered phenol compounds, thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, thiodipropionates; tinmalate, dibutyltin mono Tin compounds such as oxides can be used.

These may be used alone or in combination of two or more. The addition amount of these stabilizers is based on 100 parts by weight of the polyetherester block copolymer.
0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.2 to 2 parts by weight. Generally, antioxidants can be divided into primary, secondary and tertiary antiaging agents. Particularly, as a hindered phenol compound as a primary anti-aging agent, Irganox 1010 (trade name:
Ciba-Geigy), Irganox 1520 (trade name: Ciba-Geigy) and the like are preferable. Phosphorus compounds as secondary aging inhibitors are PEP-36, PEP-24G,
HP-10 (all trade names: manufactured by Asahi Denka Co., Ltd.)
afos168 (trade name: Ciba-Geigy) is preferred. Further, as the sulfur compound as the tertiary aging inhibitor, thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP) are preferable.

[0048] Examples of the ultraviolet absorber and light stabilizer include benzotriazole compounds and benzophenone compounds. As the light stabilizer, a radical scavenging light stabilizer such as a hindered amine compound is suitably used.

Further, the composition of the present invention may optionally contain a plasticizer. Examples of such a plasticizer include phthalic acid esters such as dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, diisononyl phthalate: tricresyl phosphate, triethyl phosphate, Tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, tris-chloroethyl phosphate, tris-
Phosphates such as dichloropropyl phosphate: octyl trimellitate, isodecyl trimellitate, trimellitate, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl azelate,
Dioctyl azelate, dioctyl sebacate, di-2
Fatty acid esters such as ethylhexyl sebacate and methylacetyl ricinocate: pyromellitic esters such as octyl pyromellitic acid: epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized fatty acid alkyl esters: Polyether plasticizers such as adipic acid ether ester and polyether: liquid N
Liquid rubbers such as BR, liquid acrylic rubber and liquid polybutadiene: non-aromatic paraffin oils and the like.

These plasticizers can be used alone or in combination of two or more. The addition amount of the plasticizer is appropriately selected according to the required hardness and physical properties, but is preferably 0 to 50 parts by weight per 100 parts by weight of the composition.

The elastomer composition may contain an inorganic filler, a lubricant, a coloring agent, a silicone oil, a foaming agent, a flame retardant, and the like. Examples of the inorganic filler include calcium carbonate, talc, magnesium hydroxide, mica, barium sulfate, silicic acid (white carbon), titanium oxide,
And carbon black.

Shore D of the thermoplastic elastomer of the present invention
The hardness is preferably from 20 to 70, more preferably from 25 to 70.
The range is 50. If the Shore D hardness is less than 20, heat resistance and scratch resistance are inferior. On the other hand, if the Shore D hardness exceeds 70, the obtained low-temperature performance and soft feeling are insufficient, which is not preferable.

Further, the melt flow rate of the thermoplastic elastomer of the present invention (at 230 ° C. under a load of 2.16 kg,
(Hereinafter abbreviated as MFR) is 0.5 to 100 g / 10 min, preferably 5 to 50 g / 10 min, more preferably 10 to 3 g.
0 g / 10 minutes. If the MFR is less than 0.5 g / 10 minutes, the injection moldability is poor and short shots are caused, which is not preferable. On the other hand, if the MFR exceeds 100 g / 10 minutes, not only are mechanical properties (breaking strength, breaking elongation, etc.) and wear properties inferior, but also low-temperature performance is unfavorably deteriorated.

In general, any method known in the art for blending polymer components may be used to prepare the elastomeric composition of the present invention.
In order to obtain the most homogeneous blend, a method of melt-kneading using various kinds of kneading machines such as commonly used mixing rolls, kneaders, Banbury mixers and extruders is desirable. Before melt-kneading, these compounds are dry-blended in advance using a mixer such as a Henschel mixer, tumbler or ribbon blender, and the mixture is melt-kneaded to obtain a homogeneous elastomer composition.

As the molding method of the elastomer composition of the present invention, injection molding, extrusion molding, compression molding and the like can be applied, but it has a feature that it is particularly excellent in moldability at the time of injection molding. When performing injection molding, a normal plastic molding machine can be used, and an injection molded product can be obtained in a short time. In addition, the elastomer composition has an advantage that the sprue portion and the runner portion can be recycled because of its excellent thermal stability.

[0056]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the examples and comparative examples, the test methods used for various evaluation methods are as follows. (1) Shore D hardness [-]: ASTM D2240, D
Type, measured at 23 ° C. (2) Melt flow rate (MFR) [g / 10 min]:
ASTM D1238 was measured at 230 ° C. under a load of 2.16 kg. (3) Tensile strength [kgf / cm ² ]: JIS K625
No. 1 and No. 3 dumbbells and 2 mm thick pressed sheets were used as samples. (4) Elongation [%]: JIS K6251, No. 3 dumbbell, 2 mm thick pressed sheet was used as a sample. (5) Rebound resilience [%]: JIS K6255, Lupke pendulum, 23 ° C. (6) Embrittlement temperature [° C.]: JIS K6261, Gehman torsion test, t100 temperature

(7) Scratch resistance and gloss retention [%]: A flat plate with a smooth surface was formed by injection molding. A flat plate is placed horizontally, and a cotton cloth to which a load of 40 g / cm ² is applied is placed.
Reciprocated twice. The glossiness of the friction surface is determined according to JIS K7105.
(E1), and the retention ratio from the glossiness (E0) before friction; (E1 / E0) × 100 (%) was determined.

(8) Crack drop test: A flat plate having a surface grain (matte, edging depth about 20 microns) was formed by injection molding. The plate was left in an oven at 100 ° C. for 168 hours. After being taken out of the oven, the surface condition was visually observed, and those having no change were evaluated as ○, slightly glossy as Δ, and glossy as ×.

(9) Formability: A flat plate having a length of 150 mm, a width of 100 mm and a thickness of 2 mm was molded by an injection molding machine under the following conditions (gate; side gate having a cross section of 10 × 2 mm). Observe the appearance of the molded product, such as flow mark and gloss, by visual observation.
Poor ones were marked as x. Cylinder temperature C1: 200
° C, C2: 210 ° C, C3: 210 ° C, nozzle temperature: 2
00 ° C, injection speed: low, mold temperature: 40 ° C

(10) Evaluation of Peelability A flat plate was formed in the same manner except that the injection speed was increased under the above-mentioned injection molding conditions. The case where the peeling phenomenon occurred in the gate portion was visually evaluated as poor, and the case where the peeling phenomenon was not observed was evaluated as good.

(11) Sweat Resistance Test The injection test piece was subjected to artificial sweat (artificial sweat composition; 7 g of NaCl,
It was immersed in 500 cc of methyl alcohol, 1 g of urea, 4 g of lactic acid, and 500 cc of distilled water at room temperature for 30 days. The test piece was taken out and subjected to an abrasion test (JIS K7
204 after wear test) was rated on a scale of 3. 3: no scratches due to worn wheels were observed at all 2: scratches due to worn wheels were slightly observed 1: scratches caused by worn wheels were clearly observed

The components used in the examples and comparative examples are as follows. Component (A): Polyurethane Elastomer A method for synthesizing an aliphatic copolycarbonate diol is shown below as a reference example.

Reference Example 1 970 g of ethylene carbonate (EC) was placed in a 3 liter flask equipped with a Dixon packing 3φ and having a diameter of 10 mm and a length of 300 mm, a distillation column, a thermometer and a stirrer.
(11 mol), 1,6-hexanediol (HDL) 6
50 g (5.5 mol) and 570 g (5.5 mol) of 1,5-pentanediol (PDL) were added, and 20 torr was added.
The mixture was heated and stirred under reduced pressure, and the internal temperature was controlled to 150 ° C. The reaction was carried out for 20 hours while distilling EC having an azeotropic composition and ethylene glycol (hereinafter abbreviated as EG) from the top of the distillation column. Next, the distillation column was removed, the degree of vacuum was reduced to 7 torr, and unreacted EC and diol were recovered. After the completion of the distillation of unreacted substances, the internal temperature is set to 190 ° C,
By distilling out the diol while maintaining the temperature, a self-condensation reaction was performed to increase the molecular weight. Four hours later, G
A polymer having a molecular weight of 2000 was obtained by PC analysis. The yield was 740 g and the hydroxyl value was 56 mgKOH / g. This polymer is abbreviated as pc-a.

Reference Examples 2 and 3 1,4-butanediol (BDL) as the diol,
Aliphatic copolycarbonate diol (pc-pc) was prepared in the same manner as in Reference Example 1 except that 1,5-pentanediol and 1,6-hexanediol were used and the amounts shown in Table 1 were used.
b, pc-c). Table 1 shows the respective molecular weights.

[0065]

[Table 1]

Raw materials used in Examples and Comparative Examples,
And the evaluation method is as follows. 1. Polyurethane elastomer (hereinafter abbreviated as TPU) Component (A) Component (A) -1 (TPU-1): pc- obtained in Reference Example 1
a 200 g, hexamethylene diisocyanate 67.2
g was charged into a reactor equipped with a stirrer, thermometer and cooling tube, and reacted at 100 ° C. for 4 hours to obtain a prepolymer having terminal NCO. 30 g of 1,4-butanediol as a chain extender and 0.006 g of dibutyltin dilaurate as a catalyst are added to the prepolymer, and a universal extruder for a laboratory with a built-in kneader (a universal extruder for LABO manufactured by Kasamatsu Chemical Industry Laboratory Co., Ltd.). KR-
(Type 35) at 140 ° C. for 60 minutes, and then pelletized by an extruder. Shore D hardness of urethane elastomer is 3
9, MFR was 24.

Component (A) -2 (TPU-2): TP was used except that pc-b was used as the polycarbonate diol.
Polymerization was carried out in the same manner as in the synthesis method of U-1 to obtain a urethane elastomer. The Shore D hardness of the obtained urethane elastomer was 40, and the MFR was 20.

Component (A) -3 (TPU-3): TP was used except that pc-c was used as the polycarbonate diol.
Polymerization was carried out in the same manner as in the synthesis method of U-1 to obtain a urethane elastomer. The resulting urethane elastomer had a Shore D hardness of 43 and an MFR of 23.

Component (A) -4 (TPU-4): Polycaprolactone polyol (manufactured by Daicel, Placcel 220, molecular weight 2,0 instead of polycarbonate diol)
(00), except that TPU-1 was used. The resulting urethane elastomer had a Shore D hardness of 45 and an MFR of 27.

Component (A) -5 (TPU-5): Miractran E190 (manufactured by Nippon Miractran, MDI / adipate TPU), Shore D hardness 45, MFR: 28

2. Polypropylene mixture component (B) Preparation of solid catalyst; anhydrous MgCl ₂ and 49.5 g of absolute ethanol, 100 ml of petrolatum oil and 100 ml of silicon oil until 120 mg of MgCl ₂ completely dissolved
The mixture was stirred at ℃ under a nitrogen atmosphere. The mixture is then mixed with 150 ml of petrolatum oil and 150 ml of silicone oil.
After being transferred into a 1500 ml autoclave containing ml in advance, the mixture was stirred at 120 ° C. and 3000 rpm for 3 minutes. 1000 ml of cooled n-heptane
The mixture was added under agitation with stirring to precipitate a spherical solid of MgCl ₂ .3EtOH (average particle size: 30 to 150 μm). Further, the obtained solid is heated from 50 ° C to 100 ° C under a nitrogen atmosphere.
, And the mixture was adjusted to a EtOH / MgCl ₂ molar ratio of 1.27. The resulting solid has a porosity of 0.139.
cc / g, surface area: 9.1 m ² / g, bulk density: 0.564 g
/ Cc.

25 g of this solid (carrier) was mixed with TiCl ₄ 6
25 cc in an autoclave with stirring and containing
C. under a nitrogen atmosphere. Further, the temperature of the autoclave was raised to 100 ° C. over 1 hour. When the temperature reached 40 ° C. in the heating process, diisobutyl phthalate was added at a molar ratio of 1/8 of magnesium. 100 ℃
After stirring for 2 hours, the mixture was allowed to stand at the same temperature to precipitate a solid.
The supernatant was removed by suction with a siphon. TiCl ₄ 5
50 ml was newly added, and the mixture was stirred at 120 ° C. for 1 hour and allowed to stand. After the supernatant was removed by suction with a siphon, the remaining solid was washed with 200 ml of anhydrous hexane six times at 60 ° C. and three times at room temperature. After drying in vacuum, it was used as a catalyst for polymerization of component (B).

The components (B) -1 and (B) -2 were polymerized by the following method. The polymerization was carried out continuously in a series of reactors equipped with a device for transferring sequentially from one reactor to the next. In a 22 liter stirred autoclave, consist of 16 liters of liquid propylene at 20 ° C. and a mixture of about 0.15 g of the above-mentioned solid catalyst, 75 ml of a 10% hexane solution of triethylaluminum and cyclohexylmethyldimethoxysilane (CMMS). A polymerization catalyst (Al / CMMS molar ratio 7.5) was added,
For 24 minutes. The prepolymer was then sent to a first reactor in the gas phase where propylene homopolymerization was performed. Further, the polymer was transferred to a second reactor, where copolymerization of ethylene and propylene was performed. Table 2 shows the polymerization conditions of the first and second reactors and the properties of the final product obtained.

[0074]

[Table 2]

Component (B) -3: Cataloy Adflex KS-084P, manufactured by Montell, MFR 30 g / 10
Minutes. Flexural modulus 108 MPa, Shore D hardness 44, average dispersed particle size of rubber 0.4 μm.

Component (B) -4: manufactured by Montell, Cataloy Adflex KS-359P, MFR 12 g / 10
Minutes. Flexural modulus 83 MPa, Shore D hardness 41, average dispersed particle size of rubber 0.6 μm.

Component (b) -5: Cataloy Adflex KS-221P, MFR 2.5 g / 1, manufactured by Montell
0 minutes. Flexural modulus 350 MPa, Shore D hardness 53, average dispersed particle size of rubber 0.5 μm.

3. Modified polymer component (C) Component (C) -1: number-average molecular weight 55,000, molecular weight distribution 1.08, bound styrene content 20% by weight, 1,2-vinyl bond content of polybutadiene part before hydrogenation is 35 weighted %, Styrene / polybutadiene part having a hydrogenation rate of 99% /
A hydrogenated block copolymer of a butadiene block copolymer was synthesized by the method described in JP-A-60-220147, and maleic anhydride was added in an extruder at a weight of 2% based on the weight of the hydrogenated block copolymer. % Added.

Component (C) -2: Maleic EPR obtained by modifying ethylene / propylene copolymer rubber (EPR) with maleic anhydride (trade name: Modick, manufactured by Mitsubishi Chemical Corporation, maleic anhydride content: 1.2% by weight, MI: 1.0 g / 10
Minutes).

Component (C) -3: Number average molecular weight of 55,000
0, molecular weight distribution 1.08, bound styrene content 20% by weight,
A hydrogenated block copolymer of a styrene / butadiene block copolymer having a 1,2-vinyl bond content of 35% by weight in the polybutadiene portion before hydrogenation and a hydrogenation rate of 99% in the polybutadiene portion is disclosed in JP-A-60-220147. Glycidyl methacrylate was added in an extruder in an amount of 2% by weight to the hydrogenated block copolymer in a method described in the official gazette.

Component (C) -4: Epoxy-modified polyethylene (manufactured by Sumitomo Chemical Co., Ltd., Bond First E, glycidyl methacrylate: 12% by weight copolymerized polyethylene, M
FR: 3 g / 10 minutes)

Examples 1 to 12 (A) -1, (A)-
2, (A) -3, (A) -4, (A) -5, and (B) -1, (B) -2,
(B) -3, (B) -4, and (B) -5 were used, and (C) -1, (C) -2, and (C) -3 were used as modified polymers. After blending with a Henschel mixer at the respective ratios shown in No. 5, the mixture was melt-kneaded with a 45 mm diameter co-directional twin screw extruder at 220 ° C. to obtain pellets of an elastomer composition. Tables 3, 4, and 5 show the results of the physical properties and the molding processability.

[0083]

[Table 3]

[0084]

[Table 4]

[0085]

[Table 5]

Examples 13 to 16 (A) -1 was used as the polyurethane elastomer, (B) -2 was used as the polypropylene mixture, and (C) -1 was used as the modified polymer. After blending with a Henschel mixer, the mixture was melt-kneaded with a 45 mm diameter co-directional twin screw extruder at 220 ° C to obtain pellets of an elastomer composition. Table 6 shows the results of the physical properties and the molding processability.

[0087]

[Table 6]

Comparative Examples 1 to 6 (A)-
Using (B) -2 as a polypropylene mixture and (C) -1 as a modified polymer, kneading was carried out in the respective proportions shown in Table 7 in the same manner as in Example 1, and evaluated. Also, instead of the polypropylene mixture of the present invention,
For comparison, an extruded blend type TPO (PP / EP
DM blend) Santoprene 203-
40 (flexural modulus 80 MPa, Shore D hardness 40, MF
(R8 g / 10 min, rubber dispersed particle diameter 9 μm) and kneaded at the respective ratios shown in Table 7 in the same manner as in the method of Example 1 and evaluated. The results are shown in Table 7. From this result, it is clear that the composition outside the range of the present invention has any bad physical properties.

[0089]

[Table 7]

[0090]

The elastomer composition obtained by the present invention is excellent in scratch resistance, strength, heat resistance, flexibility, and moldability, so that it can be suitably used in the fields of automobile parts, home electric parts, toys, miscellaneous goods and the like. Although it can be used, it is particularly suitable for automotive interior parts such as instrument panels, armrests, handles, horn pads, etc., and interior and exterior parts for automobiles such as window moldings and bumpers, which require a product appearance due to its excellent scratch resistance. Can be. Further, since the surface of the molded article is excellent in scratch resistance and molding workability, the coating step which has been conventionally required can be eliminated, so that high productivity and low cost can be realized.

Claims (4)

[Claims] 1. A thermoplastic elastomer composition comprising the following components (A), (B) and (C). (A) polyurethane elastomer: 100 parts by weight (B) (B-1) a homopolymer of polypropylene or a copolymer of propylene and an α-olefin (containing 85% by weight or more of propylene) or an ethylene-propylene copolymer ( (Contains 85% by weight or more of propylene): 10 to 60% by weight (B-2) Ethylene-propylene copolymer (containing 75% by weight or less of propylene) or ethylene-propylene-
α-olefin copolymer (containing 75% by weight or less of propylene): a mixture of 40 to 90% by weight, wherein the average dispersed particle size of the ethylene-propylene-based copolymer rubber in the mixture is 2 μm or less; Has a flexural modulus of 20 to 700 MPa and a Shore D hardness of 2
0 to 60, a polypropylene mixture having a melt flow rate of 10 to 60 g / 10 min: 10 to 900 parts by weight (C) a modified polymer having a carboxylic acid group or its derivative group, or an epoxy group or its derivative group in the molecule: 3 to 100 parts by weight 2. The thermoplastic elastomer according to claim 1, wherein the polyurethane elastomer is a polyurethane elastomer obtained by copolymerizing the following components (a), (b) and, if necessary, component (c). Composition. (A) a polycarbonate diol comprising a repeating unit represented by the following formula (1) and having a terminal group of a hydroxyl group (wherein R
Represents an aliphatic or alicyclic hydrocarbon group having 2 to 10 carbon atoms). Embedded image (B) Polyisocyanate (c) Chain extender having two active hydrogens capable of reacting with polyisocyanate 3. The polycarbonate diol comprises a repeating unit of the following formulas (2) and (3), and includes an aliphatic polycarbonate diol having a hydroxyl group as a terminal group,
The ratio of the above (2) and (3) is (2) / (3) = 10/9
3. The thermoplastic elastomer according to claim 2, wherein the polyol is a high molecular weight polyol (where n is an integer of 4 and / or 5), which is 0 to 90/10 (molar ratio). Composition. Embedded image Embedded image 4. The polypropylene composition (B) is a mixture mainly composed of polypropylene obtained by sequential polymerization of at least two or more stages. In the first step, a homopolymer of propylene or a copolymer of propylene and an α-olefin is used. After polymerizing the copolymer (containing 85% by weight or more of propylene) or the ethylene-propylene copolymer (containing 85% by weight or more of propylene), ethylene-propylene or ethylene-propylene containing a small amount of a diene as required in the second and subsequent steps.
The elastomer composition according to any one of claims 1 to 3, wherein the composition is obtained by polymerizing a propylene-α-olefin copolymer.