JP2001207051A - Polyurethane elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane elastomer composition a molded article of which is excellent in the surface damage resistance (scratch resistance) as well as in the flexibility, thermal resistance, low-temperature characteristics, weatherability, strengths, hydrolysis resistance and moldability, therefore which is useable for automobiles, household electric appliances, toys, miscellaneous goods, or the like, and besides, which can exclude a coating process and realize a high productivity and a low cost so that the molded article is excellent in the scratch resistance. SOLUTION: This elastomer composition comprises 100 pts.wt. of (a) a polyurethane-based thermoplastic elastomer and 5-900 pts.wt. of (b) a polypropylene mixture consisting of 10-60 wt.% of (b-1) a polypropylene-based polymer (containing 85 wt.% or more of propylene) and 40-90 wt.% of (b-2) an ethylene/propylene-based copolymer rubber (containing 75 wt.% or more of propylene), with the polypropylene mixture having an average dispersed- particle diameter of the ethylene/propylene copolymer rubber of 2 μm or less, a bending modulus of 20-700 MPa and a Shore D hardness of 20-60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a molded article having excellent scratch resistance (scratch resistance), flexibility, heat resistance, and the like.
The present invention relates to a thermoplastic elastomer composition which can be used as a material for various molded articles having excellent low-temperature characteristics, weather resistance, strength, hydrolysis resistance, and moldability.

[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. Urethane-based elastomers are excellent in scratch resistance, but have problems in hydrolyzability, and have drawbacks of high specific gravity and high cost. 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]

The present invention has been made in view of the above-mentioned conventional technical problems, and has excellent flexibility, weather resistance, heat resistance, low-temperature characteristics, strength, hydrolysis resistance, and moldability. The present invention provides a thermoplastic elastomer and an elastomer member which is excellent in scratch resistance and does not require surface coating.

[0006]

That is, the present invention relates to (a) a polyurethane-based thermoplastic elastomer: 100 parts by weight. (B) (b-1) a polypropylene-based polymer (propylene is 85 parts by weight).
(B-2) ethylene-propylene-based copolymer rubber (containing 75% by weight or less of propylene): a mixture of 40 to 90% by weight, and ethylene-propylene-based copolymer rubber The average dispersion particle size of the polymer rubber is 2 μm or less, and the flexural modulus of the mixture is 2
The present invention relates to an elastomer composition comprising a polypropylene mixture having a hardness of 0 to 700 MPa and a Shore D hardness of 20 to 60: 5 to 900 parts by weight.

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

The aliphatic polycarbonate diol used for the soft segment of the polycarbonate-based TPU includes:
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 a thermoplastic elastomer composition having an excellent balance between hydrolysis resistance (perspiration resistance) and weather resistance, 1,4-hexanediol, 1,5-pentanediol, 1,6-hexanediol It is particularly preferable to use an aliphatic diol such as

Further, copolycarbonate diols obtained by copolymerizing these 1,4-hexanediols, 1,5-pentanediol and 1,6-hexanediol are excellent in rubber elasticity and low-temperature properties, and are particularly suitable. Can be used.

The average molecular weight of the polycarbonate diol used for the soft segment of the polycarbonate-based TPU is usually from 500 to 30,000 in number average molecular weight, preferably from 600 to 20,000, more preferably from 700 to 60,000. Preferably, the polymer ends are substantially all hydroxyl groups.

In the polycarbonate type TPU, in addition to the diols described above, compounds having three or more hydroxyl groups in one molecule, for example, trimethylolethane,
Polyurethanes using polycarbonates multifunctionalized by using small amounts of trimethylolpropane, hexanetriol, pentaerythritol and the like are also included.

The polyisocyanate used in the TPU of the present invention includes, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and a mixture thereof (TDI), diphenylmethane-4,4'-diisocyanate (MDI ), Naphthalene-1,5-diisocyanate (NDI), 3,3′-dimethyl-4,4′-
Known aromatic diisocyanates such as biphenylene diisocyanate, crude TDI, polymethylene polyphenyl isocyanate, and crude MDI; known aromatic alicyclic diisocyanates such as xylylene diisocyanate (XDI) and phenylene diisocyanate; 4,4'-methylenebiscyclohexyl diisocyanate (Hydrogenated MDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), known aliphatic diisocyanates such as cyclohexane diisocyanate (hydrogenated XDI), and modified isocyanurates and carbodiimides of these isocyanates And modified biuret products.

In the present invention, suitable chain extenders used as needed 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.

The method for producing the TPU of the present invention includes:
Techniques for urethanization reactions known in the polyurethane industry are used. For example, polyol (polycarbonate diol, polyester diol, polyether diol, etc.)
And an organic polyisocyanate at room temperature to 200 ° C. to produce an NCO-terminated polyurethane prepolymer.

A TPU can be produced by 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 (1969). Year)) can be used. These reactions may be carried out using a solvent. Preferred solvents include dimethylformamide, diethylformamide, dimethylacetamide,
Examples include dimethyl sulfoxide, tetrahydrofuran, methyl isobutyl ketone, dioxane, cyclohexanone, benzene, toluene, and ethyl cellosolve.

In producing the TPU of the present invention, a compound containing only one active hydrogen that 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.

A TPU using a specific polycarbonate polyol is not only excellent in flexibility and elastic recovery but also extremely good in hydrolyzability as compared with other TPUs. In this case, it is particularly preferable because the sweat resistance is excellent.

The Shore D hardness of the TPU of the present invention preferably falls within the range of 20 to 70, more preferably 25 to 50, and the soft segment amount is appropriately selected. If the Shore D hardness is less than 20, the strength and scratch resistance of the obtained thermoplastic elastomer are undesirably deteriorated. If the Shore D hardness is more than 70, the resulting thermoplastic elastomer has an unsatisfactory soft feeling, which is not preferable.

The polyurethane elastomer of the present invention preferably has a melt flow rate (at 230 ° C., under a load of 2.16 kg, hereinafter abbreviated as MFR) of 0.5 to 100 g.
/ 10 minutes, more preferably 5 to 50 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 min, not only is moldability deteriorated, but also mechanical properties (such as breaking strength and breaking elongation), abrasion, and compression set (C-Set) are inferior. .

As additives used in the present invention, it is preferable 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 0.01 to 10 parts by weight based on 100 parts by weight of TPU,
Preferably 0.1 to 5 parts by weight, more preferably 0.2
~ 3 parts by weight is desirable. 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: manufactured by Ciba Geigy), Irganox 1520 (trade name: manufactured by Ciba Geigy) and the like are preferable. PGA-36, PEP-24G and HP-10 (all trade names: manufactured by Asahi Denka Co., Ltd.) Irgafos 168 as a phosphorus-based compound as a secondary anti-aging agent.
(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.

If necessary, an ultraviolet absorber and a light stabilizer may be added in the same manner. Examples of these ultraviolet absorbers include benzotriazole-based compounds and benzophenone-based compounds. As the light stabilizer, a radical scavenging light stabilizer such as a hindered amine compound is suitably used.

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-
An olefin copolymer (containing 85% by weight or more of propylene) or an ethylene-propylene copolymer (containing 85% by weight or more of propylene) is formed by polymerization to obtain a component (b-
1), and ethylene-propylene (containing 75% by weight or less of propylene) or ethylene-propylene-α-olefin (which may contain a small amount of diene) copolymer (75% by weight or less of propylene) Is formed by polymerization to produce 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 for polymerizing 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 (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. Further, the amount of all α-olefins copolymerized in the polypropylene mixture of (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 (measured according to ASTM D1238, 230 ° C., 2.16 kg load; hereinafter abbreviated as MFR) of the mixture (b) 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 ethylene-propylene copolymer rubber dispersed in the mixture (b) has an average dispersed particle size of 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 the method for preparing the catalyst and the 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
5-900 parts by weight, preferably 10-500 parts by weight, more preferably 15-500 parts by weight, based on 100 parts by weight of component (a).
200 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 5 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.

Further, the elastomer composition of the present invention includes:
If necessary, a polyolefin resin (component c) 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, propylene, butene-1, isobutene, pentene-1, hexene-1, 4-methylpentene- 1,
Octene-1 and the like. The proportion of α-olefin is 30% by weight or less.

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 a 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.

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.

Further, the present elastomer composition contains an inorganic filler, a stabilizer, a lubricant, a coloring agent, silicone oil, a foaming agent,
A flame retardant or the like may be added. Examples of the inorganic filler include calcium carbonate, talc, magnesium hydroxide, mica, barium sulfate, silicic acid (white carbon), titanium oxide, and carbon black. Examples of the stabilizer include a hindered phenol-based antioxidant, a phosphorus-based heat stabilizer, a hindered amine-based light stabilizer, and a benzotriazole-based UV absorber. Examples of the lubricant include stearic acid, stearic acid esters, and metal salts of stearic acid.

In general, any method known in the art for blending polymer components may be used to prepare the elastomer 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.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION 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 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.

While distilling azeotropic EC and ethylene glycol (hereinafter abbreviated as EG) from the top of the distillation column, 20
A time reaction was performed. 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 the unreacted substances, the internal temperature was set to 190 ° C., and the diol was distilled while maintaining the temperature to carry out a self-condensation reaction to increase the molecular weight. 4 hours later, GP
A polymer having a molecular weight of 2000 was obtained by C analysis. The yield was 740 g and the hydroxyl value was 56 mgKOH / g. This polymer is abbreviated as pc-a.

Reference Examples 2 to 5 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 to pc-e) were obtained. Table 1 shows the respective molecular weights.

[0045]

[Table 1]

Raw materials used in Examples and Comparative Examples,
And the evaluation method is as follows. Component (a) TPU component (a) -1 (TPU-1): pc-a2 obtained in Reference Example 1.
00g and 67.2g of hexamethylene diisocyanate were charged into a reactor equipped with a stirrer, a thermometer, and a condenser.
The reaction was carried out at 00 ° C. for 4 hours to obtain a prepolymer having a terminal NCO. 30 g of 1,4-butanediol as a chain extender was added to the prepolymer, and 0.2 g of dibutyltin dilaurate was used as a catalyst.
Universal extruder for lab with built-in kneader (Kasamatsu Chemical Industries, Ltd. LABO universal extruder KR-
(Type 35) at 140 ° C for 60 minutes,
The mixture was extruded at a cylinder temperature of ° C. to complete the polymerization, and was formed into urethane pellets by a pelletizer. The resulting urethane elastomer had a Shore D hardness of 36 and an MFR of 28.

(A) -2 (TPU-2): except that pc-b was used as the polycarbonate diol,
Polymerization was performed in the same manner as in the synthesis method 1 to obtain a urethane elastomer. The resulting urethane elastomer has a Shore D hardness of 3
5, MFR was 25.

(A) -3 (TPU-3): except that pc-c was used as the polycarbonate diol,
Polymerization was performed in the same manner as in the synthesis method 1 to obtain a urethane elastomer. The resulting urethane elastomer has a Shore D hardness of 4
2, MFR was 30.

(A) -4 (TPU-4): except that pc-d was used as the polycarbonate diol,
Polymerization was performed in the same manner as in the synthesis method 1 to obtain a urethane elastomer. The resulting urethane elastomer has a Shore D hardness of 3
9, MFR was 29.

(A) -5 (TPU-5): except that pc-e was used as the polycarbonate diol,
Polymerization was performed in the same manner as in the synthesis method 1 to obtain a urethane elastomer. The resulting urethane elastomer has a Shore D hardness of 3
8, MFR was 23.

(A) -6 (TPU-6): poly (tetramethyleneoxy) glycol as polyether diol: PTG-1,800, M manufactured by Hodogaya Chemical Co., Ltd.
except that n = 1828 and Mv / Mn = 2.1
It was synthesized in the same manner as the synthesis method of PU-1. The Shore D hardness of the obtained urethane elastomer was 32 and the MFR was 27.

(A) -7 (TPU-7): manufactured by Dainippon Ink and Chemicals, Pandex T2185 (polycaprolactone, Shore D hardness: 33, MFR; 21)

(A) -8 (TPU-8): manufactured by Dainippon Ink and Chemicals, Pandex T1185 (adipate,
Shore D hardness; 33, MFR; 19)

Component (b): Preparation of solid catalyst; MgCl ₂
Was completely dissolved, 49.5 g of anhydrous MgCl ₂ and 49.5 g of absolute ethanol, 100 ml of petrolatum oil and 100 ml of silicone oil were stirred at 120 ° C. in a nitrogen atmosphere. The mixture was then filled with 1500 ml of pre-filled 150 ml of petrolatum oil and 150 ml of silicone oil.
after transfer to an autoclave at 120 ° C., 3000
The mixture was stirred at rpm for 3 minutes. The mixture is cooled n
-Added under stirring in 1000 ml of heptane,
spherical solid l ₂ · 3EtOH was precipitated (average particle size 3
0-150 μm). Further, the obtained solid was dried under a nitrogen atmosphere while increasing the temperature from 50 ° C. to 100 ° C.
The H / MgCl ₂ molar ratio was adjusted to 1.27. The obtained solid had a porosity of 0.139 cc / g and a surface area of 9.1 m ² / g.
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 polymerization catalyst for 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.

[0057]

[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: Cataloy Adflex KS-359P, MFR 12 g / 10, manufactured by Montell Corporation
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.

Component (c) -1 Made by JPO, Show Allomer MK711 (block type polypropylene), MFR
30 g / 10 min, flexural modulus 1400 MPa. In Examples and Comparative Examples, test methods used for various evaluation methods are as follows.

(1) Shore D hardness [-]: ASTM D
2240, D type, measured at 23 ° C.

(2) Melt flow rate (MFR) [g
/ 10 min]: ASTM D1238, 230 ° C, 2.1
It was measured under a load of 6 kg.

(3) Tensile strength [kgf / cm ² ]: JI
SK6251, No. 3 dumbbell, and a sample used a 2 mm-thick press sheet.

(4) Elongation [%]: JIS K6251,
A No. 3 dumbbell and a sample used a 2 mm-thick press sheet.

(5) Rebound resilience [%]: JIS K625
5. Lupke pendulum, 23 ° C

(6) Embrittlement temperature [° C.]: JIS K626
1. Gehman torsion test, t100 temperature

(7) Scratch resistance and gloss retention [%]: A flat plate having 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 of 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) Sweat Resistance Test A TPU flat plate was subjected to artificial sweat (artificial sweat composition; NaCl 7 g, methyl alcohol 50).
(0 cc, 1 g of urea, 4 g of lactic acid, 500 cc of distilled water) at room temperature for 30 days. The flat plate was taken out, and the appearance after the abrasion test (the appearance after the test using a JIS K7204 wear wheel) was evaluated with a 3 grade. 3; no change in appearance 2; slight change in appearance 1; change in appearance

(10) 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. The appearance of the molded product was visually observed such as flow mark and gloss, and a good one was evaluated as ○, a slightly poor one as Δ, and a poor one as ×. Cylinder temperature C
1: 200 ° C, C2: 210 ° C, C3: 210 ° C, nozzle temperature: 200 ° C, injection speed: low speed, mold temperature: 40 ° C

Examples 1 to 8 As TPUs, (a) -1, (a) -2, (a) -3,
(A) -4, (a) -5, (a) -6, (a) -7,
Using (a) -8, (b) as a polypropylene mixture
After blending with a Henschel mixer at the ratios shown in Tables 3 and 4 using -1, the mixture was melt-kneaded with a 20 mm diameter co-axial twin screw extruder at 220 ° C to obtain pellets of an elastomer composition. . Tables 3 and 4 show the results of physical properties and moldability.

[0073]

[Table 3]

[0074]

[Table 4]

Examples 9 to 12 (a) -1 was used as TPU, and (b) -2, (b) -3, (b) -4, (b)-as a polypropylene mixture.
After blending with a Henschel mixer at the ratios shown in Table 5 by using No. 5, the mixture was melt-kneaded at 220 ° C. with a 20 mm diameter co-directional twin screw extruder to obtain elastomer composition pellets. Table 5 shows the results of the physical properties and moldability.

[0076]

[Table 5]

Examples 13 and 14 (a) -1 was used as TPU, (b) -1 was used as a polypropylene mixture, and (c) -1 was used as a polyolefin resin. After blending with a Henschel mixer, the mixture was melt-kneaded with a 20 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 moldability.

[0078]

[Table 6]

Comparative Examples 1 to 3 (a) -1 and (a) -8 were used as TPUs, (b) -1 was used as a polypropylene mixture, and Sa was an extrusion blend type TPO (PP / EPDM blend).
ntoprene 203-40 (flexural modulus 80MP)
a, Shore D hardness of 40, MFR of 8 g / 10 min, rubber dispersion particle size of 9 μm), and kneading at the respective ratios shown in Table 7 in the same manner as in Examples 1 to 4, and evaluation was performed. 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.

[0080]

[Table 7]

[0081]

The elastomer composition obtained by the present invention is excellent in scratch resistance, strength, heat resistance, flexibility, hydrolysis resistance, and moldability, so that it can be used for automobile parts, home electric parts, toys, miscellaneous goods, etc. Although it can be suitably used in the field, it is particularly excellent in scratch resistance, and it is necessary to have a product appearance, such as instrument panels, armrests, steering wheels (steering wheels), horn pads, etc., and automobile interior parts such as window moldings and bumpers. It can be suitably used for exterior parts. 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.

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Claims (4)

[Claims] (A) Polyurethane-based thermoplastic elastomer: 100 parts by weight (b) (b-1) Polypropylene-based polymer (propylene is 85 parts by weight)
(B-2) ethylene-propylene-based copolymer rubber (containing 75% by weight or less of propylene): 40 to 90% by weight, wherein ethylene in the mixture is 40 to 90% by weight. The average dispersion particle size of the propylene copolymer rubber is 2 μm or less, the flexural modulus of the mixture is 20 to 700 MPa, and the Shore D hardness is 20 to
An elastomer composition comprising a polypropylene mixture having a weight ratio of 60 to 5 to 900 parts by weight. 2. A polyurethane thermoplastic elastomer obtained by copolymerizing the following components (a) and (b) and, if necessary, component (c): Plastic elastomer 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 and / 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 polypropylene composition (b) having a melt flow rate of 10 to 60 g / 10 minutes.
The elastomer composition as described in the above. 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 mixture of propylene and an α-olefin is used. After forming a copolymer (containing 85% by weight or more of propylene) or an ethylene-propylene copolymer (containing 85% by weight or more of propylene) by polymerization, ethylene-propylene containing a small amount of a diene as required in the second and subsequent steps 3. The elastomer composition according to claim 1, wherein the ethylene-propylene-α-olefin copolymer is formed by polymerization.