JP3102851B2 - Method for producing thermoplastic elastomer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a thermoplastic elastomer composition.

[0002]

2. Description of the Related Art In recent years, thermoplastic elastomers, which are rubber-like materials and do not require a vulcanizing step and have the same moldability as thermoplastic resins, have been used in automobile parts, home electric parts, wire coatings, footwear, It is attracting attention in the field of miscellaneous goods.

[0003] As such a thermoplastic elastomer,
At present, various types of polymers such as polyolefins, polyurethanes, polyesters, polystyrenes, and polyvinyl chlorides have been developed and are commercially available.

Among them, styrene-butadiene-
Block polymer (SBS), styrene / isoprene-
Polystyrene-based thermoplastic elastomers such as block polymer (SIB) and hydrogenated products thereof are rich in flexibility, have good rubber elasticity at room temperature, and the thermoplastic elastomer composition obtained therefrom has good processability. Are better.

However, these block copolymer compositions not only have insufficient compression set at high temperatures, especially at 100 ° C., but also have markedly deteriorated tensile properties especially at 80 ° C. or higher. At present, the performance level required for rubber applications has not been reached.

[0006]

SUMMARY OF THE INVENTION The present invention provides a process for producing a thermoplastic elastomer composition which is rich in flexibility, excellent in heat deformation resistance, mechanical strength and moldability.

[0007]

Means for Solving the Problems The present inventors have conducted various studies to solve the above problems. As a result, the organic peroxide generates radicals that act on the cross-linking of polyethylene and molecular cleavage of polypropylene, and in particular, has a large effect on the molecular cleavage of polypropylene, and focuses on causing a decrease in physical properties of the obtained elastomer composition.
Upon melt-kneading in the presence of an organic peroxide,
By adding the minimum amount of polypropylene necessary to increase the flowability at the time of melting as described below and adopting an amount of polyethylene that can obtain appropriate dispersibility, it is possible to promote the crosslinking of the polyethylene and the dispersion of the rubber component. It has been found that a thermoplastic elastomer composition having excellent properties can be produced, and the present invention has been completed.

That is, the present invention relates to (1) (a) a block comprising at least two polymer blocks A mainly made of a vinyl aromatic compound and at least one polymer block B mainly made of a conjugated diene compound. 100 parts by weight of a copolymer and / or a block copolymer obtained by hydrogenating the same, (b) 40 to 240 parts by weight of a non-aromatic rubber softener, and (c) a single-site catalyst. 5 to 300 parts by weight of a copolymer mainly composed of polyethylene or ethylene, (d) a copolymer mainly composed of polypropylene or propylene 5 to 60
A method for producing a thermoplastic elastomer composition by melt-kneading 0 to 100 parts by weight of (e) an inorganic filler, and (e) components (a), (b), (d) and (e). e) and a part of component (c) are melt-kneaded in advance, and then or simultaneously with (f) an organic peroxide, and then (II) the resulting melt-kneaded product and component (c) And melting and kneading the remaining part.

In a preferred embodiment, (2) the weight ratio of component (c) used in steps (I) and (II) is 90:
The production method according to the above (1), which is 10 to 10:90,
(3) Component (f) is used as a total of components (a) to (d) of 100
The above (1) in which 0.1 to 1.5 parts by weight is used per part by weight.
Or, the production method described in (2), and together with (4) component (f), (g) 0.1 to 3.5 parts by weight of a crosslinking assistant with respect to 100 parts by weight in total of (a) to (d). The production method according to any one of the above (1) to (3), wherein the step (I) is performed using
(5) (h) The antioxidant is used in a total of 10 of (a) to (d).
The production method according to any one of the above (1) to (4), wherein the step (I) is carried out using not more than 3.0 parts by weight per 0 parts by weight; The production method according to any one of the above (1) to (5), in which (d) is added and melt-kneaded, can be mentioned.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Component (a) The block copolymer is a block copolymer consisting of at least two polymer blocks A mainly made of a vinyl aromatic compound and at least one polymer block B mainly made of a conjugated diene compound, and And / or obtained by hydrogenating it. For example, A-
A vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as BA, BABA, or ABABA, or a product obtained by hydrogenating the same. is there. The block copolymer as a whole preferably contains 5 to 60% by weight, particularly preferably 20 to 50% by weight, of a vinyl aromatic compound. The polymer block A mainly composed of a vinyl aromatic compound is preferably at least 50% by weight, particularly preferably at least 70% by weight, of a vinyl aromatic compound, and a homopolymer or a conjugated diene compound. It is a copolymer block. The polymer block B mainly composed of a conjugated diene compound is preferably 50% by weight or more, particularly preferably 70% by weight or more, of a conjugated diene compound, and a homopolymer or copolymer prepared from an optional component such as a vinyl aromatic compound. It is a polymer block. Further, in the polymer block A mainly composed of these vinyl aromatic compounds and the polymer block B mainly composed of a conjugated diene compound, the distribution of units derived from the conjugated diene compound or the vinyl aromatic compound in the molecular chain is random, It may be tapered (the monomer component increases or decreases along the molecular chain), partially block-shaped, or any combination thereof. When there are two or more polymer blocks A mainly containing vinyl aromatic compounds or two or more polymer blocks B mainly containing conjugated diene compounds, each polymer block has a different structure even if each has the same structure. There may be.

As the vinyl aromatic compound constituting the block copolymer, for example, one or more of styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene and the like can be selected. Styrene is preferred. As the conjugated diene compound, for example,
Butadiene, isoprene, 1,3-pentadiene, 2,
One or more of 3-dimethyl-1,3-butadiene and the like are selected, and among them, butadiene, isoprene and a combination thereof are preferable.

In the polymer block B mainly composed of a conjugated diene compound, the microstructure can be arbitrarily selected. For example, in the case of a polybutadiene block, 1,2 is used.
The microstructure is preferably from 20 to 50% by weight, particularly preferably from 25 to 45%; In the polyisoprene block, it is preferable that 70 to 100% by weight of isoprene has a 1,4-microstructure, and that at least 90% of aliphatic double bonds derived from isoprene are preferably hydrogenated.

The number average molecular weight of the block copolymer is preferably from 5,000 to 1,500,000, more preferably from 10,000 to 550,000, and still more preferably from 1 to 550,000.
It is in the range of 00,000 to 400,000 and the molecular weight distribution is 10 or less.

The molecular structure of the block copolymer is linear,
It may be branched, radial, or any combination thereof.

Numerous methods have been proposed as methods for producing these block copolymers. Representative methods include, for example, the method described in Japanese Patent Publication No. 23798/1971 using a lithium catalyst or a Ziegler catalyst. It can be obtained by performing block polymerization in an inert medium using a type catalyst. Methods for hydrogenation are also known.

Component (b) Examples of the non-aromatic rubber softener include non-aromatic mineral oils and liquid or low molecular weight synthetic softeners. In general, a mineral oil softener for rubber is a mixture of an aromatic ring, a naphthene ring and a paraffin chain. Generally, a paraffin chain having a carbon number of 50% or more of the total carbon number is a paraffinic or naphthenic ring. 30-40 carbon atoms
% Are called naphthenics, and those whose aromatic carbon number is 30% or more are called aromatics. As the mineral oil softener for rubber used as the component (b) of the present invention, the above-mentioned paraffin-based and naphthene-based are preferred. Aromatic softeners are not preferred because of poor dispersibility in relation to component (a). As the component (b), a paraffinic mineral oil softener is particularly preferred, and among the paraffinic ones, those having less aromatic ring components are particularly suitable.

The non-aromatic rubber softener is 37.8.
Dynamic viscosity at 20 ° C. is preferably 20 to 500 cst,
Pour point is preferably −10 to −15 ° C., flash point (CO
C) preferably represents 170 to 300 ° C.

The amount of the component (b) is 100 parts (a).
The upper limit is 240 parts by weight, preferably 18 parts by weight.
0 parts by weight, and the lower limit is 40 parts by weight, preferably 80 parts by weight. If the upper limit is exceeded, bleed-out of the softening agent is likely to occur, which may give the final product tackiness, and also deteriorates the mechanical properties. If the lower limit is less than the above lower limit, the load on the kneader becomes large during the production, but the molecular breakage occurs due to the heat generated by shearing, although it may be practically acceptable. Also, the flexibility of the resulting composition is impaired. .

Component (c) Examples of polyethylene or an olefin polymer mainly composed of ethylene include high-density polyethylene (low-pressure polyethylene), low-density polyethylene (high-pressure polyethylene),
Polyethylene, such as linear low-density polyethylene (copolymer of ethylene and a small amount, preferably 1 to 10 mol% of α-olefin such as butene-1, hexene-1, octene-1), ethylene-propylene copolymer, ethylene-acetic acid One or more selected from vinyl copolymers, ethylene-acrylate copolymers and the like are preferably used. Particularly preferred is a metallocene catalyst (single site catalyst) produced with a density of 0,1.
An ethylene octene copolymer having a density of 90 g / cm ³ or less or an ethylene hexene copolymer having a density of 0.90 g / cm ³ or more. Those having a Tm of 100 ° C. or lower need to be added and crosslinked at the latest at the time of crosslinking. Due to the crosslinking, Tm disappears and octene does not melt. When the addition is performed after the crosslinking, 30 to 60 ° C
Of octene remains, and the heat resistance decreases.

For example, according to the method described in JP-A-61-296008, the support and 4b of the periodic table
Comprising a reaction product of a metallocene containing at least one metal of Group 5, 5b and 6b with alumoxane;
An olefin polymer polymerized by an olefin polymer catalyst characterized in that the reaction product is formed in the presence of a support.

JP-A-3-163008, group 3 (other than scandium) of the periodic table of elements,
A metal coordination complex comprising a Group 10 or lanthanide series metal and a delocalized π-bonded moiety substituted with a constraint inducing moiety, wherein the complex has a constrained geometry around the metal atom and The metal angle between the center of the localized substituted π-bond moiety and the center of the at least one remaining substituent is smaller in such a comparison complex in which the only difference is that the constraint-induced substituent is replaced by hydrogen. And one more
For such complexes containing one or more delocalized substituted π-bonded moieties, wherein each of the complexes has, for each metal atom, only one of them is a cyclic delocalized substituted π-bonded moiety. An olefin-based polymer polymerized from a coordination complex is exemplified.

Component (c) is preferably at a temperature of 190 ° C.
MFR at a load of 2.16 kg is preferably 0.1 to
10.0 g / 10 minutes, more preferably 0.3 to 5.0 g
/ 10 minutes. The amount of component (c) is determined by the amount of component (a) 1
The upper limit is 300 parts by weight, preferably 250 parts by weight, and the lower limit is 5 parts by weight based on 00 parts by weight. If the amount is less than the lower limit, there is no effect. If the amount exceeds the upper limit, flexibility of the obtained elastomer composition is lost, and bleed-out of the rubber softener (b) tends to occur.

Component (d) The polypropylene or the copolymer mainly composed of propylene has an effect of improving the rubber dispersion of the obtained composition and improving the appearance of a molded article. The component is an olefin-based polymer or copolymer (peroxide-decomposable olefin-based resin), which is thermally decomposed by heating in the presence of a peroxide to reduce the molecular weight and increase the fluidity during melting, and For example, isotactic polypropylene or propylene and other α-olefins such as ethylene, 1-butene, 1-hexene, 4-methyl-
Copolymers with 1-pentene and the like can be mentioned.

The crystallinity of the homo part by DSC measurement is preferably such that Tm is 150 ° C. to 167 ° C. and ΔHm is 25 mJ.
/ Mg to 83 mJ / mg. The crystallinity can be estimated from Tm and ΔHm measured by DSC. Outside the above range, the rubber elasticity of the obtained elastomer composition at 100 ° C. or higher is not improved.

The MFR of component (d) (ASTM D-12
38, L condition, 230 ° C) is preferably 0.1 to 50.
g / 10 minutes, more preferably 0.5 to 20 g / 10 minutes. When the amount is less than the above lower limit, the moldability of the obtained elastomer composition is reduced, and when the amount exceeds the above upper limit, the rubber elasticity of the obtained elastomer composition is deteriorated.

The amount of the component (d) is 100 parts (a)
The upper limit is 60 parts by weight, preferably 30 parts by weight, and the lower limit is 5 parts by weight, preferably 10 parts by weight with respect to parts by weight. If the amount is less than the lower limit, the moldability of the obtained elastomer composition is deteriorated.If the amount exceeds the upper limit, the hardness of the obtained elastomer composition is too high, the flexibility is lost, and a rubber-like product cannot be obtained. Or bleed-out.

After melt-kneading in the presence of an organic peroxide, the component (d) is further kneaded to adjust the hardness of the composition or to adjust the moldability, for example, to adjust the appearance and shrinkage. Can also. At this time, component (d)
MFR (ASTM D-1238, L condition, 230
C) is preferably 0.1 to 200 g / 10 min, more preferably 0.5 to 60 g / 10 min. Outside this range, the same adverse effects as described above occur, which is not preferable. The upper limit is preferably 50 parts by weight, particularly preferably 20 parts by weight, and the lower limit is preferably 5 parts by weight, particularly preferably 10 parts by weight, based on 100 parts by weight of the component (a).
Parts by weight. If the amount is less than the lower limit, the moldability of the obtained elastomer composition cannot be sufficiently adjusted.If the amount exceeds the upper limit, the resulting elastomer composition has too high hardness, loses flexibility, and has a rubbery feel. Can not be obtained.

Component (e) If necessary, an inorganic filler can be blended. Inorganic fillers have the effect of improving some physical properties such as compression set of molded articles, and also have the economic advantage of increasing the amount.
Examples of the inorganic filler used include calcium carbonate, talc, magnesium hydroxide, mica, clay, barium sulfate, natural silicic acid, synthetic silicic acid (white carbon), titanium oxide, and carbon black. Of these, calcium carbonate and talc are particularly preferred. The amount is up to 100 parts by weight based on 100 parts by weight of component (a). If it exceeds 100 parts by weight, the mechanical strength of the obtained elastomer composition is remarkably reduced, and the hardness is increased to lose the flexibility, so that a rubber-like product cannot be obtained.

Component (f) The organic peroxide promotes the crosslinking of the component (c), promotes the molecular cleavage of the component (d), increases the fluidity of the composition during melt-kneading, and disperses the rubber component. Is good. Such components include, for example, dicumyl peroxide, di-tert-butyl peroxide,
2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di-
(Tert-Butylperoxy) hexyne-3,1,3
-Bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy)
-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert- Butyl peroxybenzoate, ter
t-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, ter
t-butylcumyl peroxide and the like. Among these, from the viewpoints of odor, coloring and scorch safety, 2,5-dimethyl-2,5-di- (ter
t-butylperoxy) hexane, 2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexyne-3 is particularly preferred.

The compounding amount of the component (f) is the same as that of the component (a)
Is determined in consideration of the compounding ratio of (e), particularly the quality of the obtained thermoplastic elastomer.
The upper limit is preferably 1.5 parts by weight, particularly preferably 1.0 part by weight, and the lower limit is preferably 0.1 part by weight, based on 100 parts by weight in total of (d). If the upper limit is exceeded, the moldability will be poor, and if it is less than the lower limit, crosslinking cannot be sufficiently achieved, and the heat resistance and mechanical strength of the obtained elastomer will be low.

Component (g) The component (g) crosslinking aid can be blended during the crosslinking treatment with the above (f) organic peroxide in the process for producing the elastomer composition of the present invention, whereby a uniform and efficient crosslinking is achieved. Cross-linking reaction can be performed. (G) Examples of the crosslinking auxiliary include divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate,
Incorporate multifunctional methacrylate monomers such as diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate, and polyfunctional vinyl monomers such as vinyl butyrate or vinyl stearate. be able to. Among the above crosslinking aids, triethylene glycol dimethacrylate is particularly preferred, and the compound is
It is easy to handle, has good compatibility with the main component (c) in the composition, has a peroxide solubilizing effect, and acts as a peroxide dispersing agent. In addition, it is possible to obtain a thermoplastic elastomer which is effectively and well-balanced in hardness and rubber elasticity. The compounding amount of the crosslinking aid is also determined by the above component (a).
Is determined in consideration of the compounding ratio of (e), particularly the quality of the obtained thermoplastic elastomer.
The upper limit is 3.5 parts by weight, preferably 2.5 parts by weight, and the lower limit is 0.1 part by weight based on 100 parts by weight in total of (d). If the amount exceeds the above upper limit, the degree of cross-linking is reduced due to self-polymerization, and no effect can be obtained. If the amount is less than the above lower limit, the effect of the substance cannot be sufficiently achieved.

The composition of the present invention may contain, in addition to the above components, various antiblocking agents, sealant improvers, heat stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, depending on the intended use. , A nucleating agent, a coloring agent, a flame retardant and the like. Here, as the antioxidant, for example,
2,6-di-tert-p-butyl-p-cresol,
Phenols such as 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4-dihydroxydiphenyl, and tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane Antioxidants, phosphite antioxidants,
And thioether-based antioxidants. Of these, phenolic antioxidants and phosphite antioxidants are particularly preferred. The antioxidant comprises the components (a) to (d) described above.
Is 100 parts by weight, and the upper limit is 3.0 parts by weight, preferably 1.0 part by weight.

The method for producing the elastomer composition of the present invention comprises:
(I) The total amount of the components (a), (b), (d) and (e) and a part of the component (c) are melt-kneaded in advance, and then or simultaneously with (f) the melt-kneading with an organic peroxide,
(II) This is a method of melt-kneading the obtained product after melt-kneading and the remainder of the component (c).

In the method, component (c) is used in step (I)
And (II) are melt-kneaded. The distribution ratio is preferably 90:10 to 10:90 by weight, particularly preferably 50:50 to 20:80. Step (I)
If the amount of the melt-kneading is too large, the crosslinking will proceed too much, increasing the load on the kneading machine at the time of production, causing molecular breakage due to shear heat generation, and the dispersibility of (c) resulting in an elastomer obtained. Affects the properties of the composition. If the amount is too small, appropriate crosslinking cannot be obtained, which is not preferable.

When using the above-mentioned component (g) crosslinking aid, it is preferably melt-kneaded in step (I) together with component (f) an organic peroxide. As a result, the above effects can be achieved.

Next, one embodiment of the production method of the present invention will be described. For example, first, an antioxidant, a light stabilizer, a pigment, a flame retardant, a lubricant, and the like are optionally added to the entire amount of the components (a), (b), (d), and (e) and a part of the component (c). In addition, it is melt-kneaded. There is no particular limitation on the method of melt kneading, and a generally known method can be used. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like can be used. Here, the temperature of the melt-kneading is preferably 160 to 180 ° C. The product obtained by the melt-kneading is then combined with component (f) and preferably component (g)
Is added and melt-kneaded. Thereby, partial crosslinking of component (c) can be achieved. The melt-kneading is generally performed by, for example, a twin-screw extruder, a Banbury mixer, or the like. Subsequently, the remainder of the component (c) and, if desired, the component (d) are further added to the product obtained by the melt kneading, followed by melt kneading. The temperature of melt-kneading for crosslinking is preferably 18
The temperature is 0 to 240 ° C, particularly preferably 180 to 220 ° C. For the melt-kneading, for example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like can be used. For example, the above operation can be performed continuously by using a twin-screw extruder having an L / D of 47 or more and a Banbury mixer.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0038]

EXAMPLES The evaluation methods used in the examples and comparative examples are as follows. 1) Hardness According to JIS K 7215, a 6.3 mm-thick pressed sheet was used as a test piece. 2) Tensile strength According to JIS K 6301, a test piece was prepared by punching a 1 mm thick pressed sheet into a No. 3 die using a dumbbell. Test temperature is room temperature (23 ° C), 60 ° C, 80
° C, and the tensile speed was 500 mm / min. 3) Tensile Elongation In accordance with JIS K 6301, a test piece was prepared by punching a 1 mm thick pressed sheet into a No. 3 die using a dumbbell. The tensile speed was 500 mm / min. 4) 100% elongation stress According to JIS K 6301, a test piece was prepared by punching a 1 mm thick pressed sheet into a No. 3 die using a dumbbell. The tensile speed was 500 mm / min. 5) Rebound resilience Based on BS903, a test piece used a 4 mm-thick press sheet. 6) Compression set In accordance with JIS K 6262, a 6.3 mm thick press sheet was used as a test piece. 100 ℃
× 70 hours, measured under the condition of 25% deformation. 7) Tear strength According to JIS K 6301, a test piece was used by punching a 2.5 mm-thick pressed sheet into a B type with a dumbbell. The tensile speed was 500 mm / min. 8) Oil resistance According to JIS K 6301, a test piece was prepared by punching a 1 mm thick pressed sheet into a No. 3 die using a dumbbell. Using ASTM No. 2 oil, the residual tensile strength and residual elongation at 100 ° C. for 24 hours were measured. Tensile speed is 5
00 mm / min. 9) Formability With an injection molding machine with a mold clamping pressure of 120 tons, 1
A sheet of 2.5 × 13.5 × 1 mm was formed under the following conditions.

Molding temperature 220 ° C. Mold temperature 40 ° C. Injection speed 55 mm / sec Injection pressure 1400 kg / cm ² Holding pressure 400 kg / cm ² Injection time 6 seconds Cooling time 45 seconds Delamination, deformation and significantly deteriorating appearance Evaluation was made based on the presence or absence of a flow mark.

：: good ×: bad 10) Bleed-out property After the above molded article was compressed by 50% in an environment of 100 ° C. × 22 hours, the presence or absence of bleeding and blooming of a low molecular weight material by visual inspection, and the stickiness due to tactile sensation were observed. The presence or absence was evaluated.

：: good ×: bad 11) DSC measurement Approximately 20 mg was cut out from the above molded article and a sample for DSC measurement was cut out.
Pulled. DSC220C (SII, Seiko Electronics
Using the range of -50 ℃ ~ 200 ℃
DSC measurement was performed at 10 ° C./min, and the glass transition point (T
g₁), Melting point (Tm₁, Tm_Two), Crystallization temperature (Tc
 ₁, Tc_Two). Where Tm₁, Tc ₁Is
Due to ethylene, Tm_Two, Tc_TwoIs
This is due to polypropylene. 12) Gloss The gloss of the above molded product was measured in accordance with JIS Z8741.
Specified. The higher the value, the smoother the surface
The smaller the value, the rougher the surface.

The components used in the examples and comparative examples are as follows. Component (a): hydrogenated block copolymer Septon 4077 (trade name) manufactured by Kuraray Co., Ltd. Styrene content: 30% by weight Isoprene content: 70% by weight Number average molecular weight: 260,000 Weight average molecular weight: 320,000 Molecular weight distribution : 1.23 Hydrogenation rate: 90% or more Component (b): Rubber softener Diana Process Oil PW- manufactured by Idemitsu Kosan Co., Ltd.
90 (trademark) Weight average molecular weight: 539 Paraffin-based carbon number: 71% Naphthene-based carbon number: 29% Component (c): (c-1) Ethylene-octene copolymer Engage EG81 manufactured by Dow Chemical Japan Co., Ltd.
50 (trademark) density: 0.868 g / cm ³ , melt index (1
90 ° C., load 2.16 kg): 0.5 g / 10 min (c-2) Ethylene-hexene copolymer SP2520 (trademark) manufactured by Mitsui Petrochemical Industries, Ltd. Density: 0.928 g / cm ³ , melt index (1
90 ° C., load 2.16 kg): 1.7 g / 10 min (c-3) polyethylene (for comparison of component (c),
It is a normal polyethylene not polymerized with a single-site catalyst. ) V-0398CN (trademark) manufactured by Idemitsu Petrochemical Co., Ltd. Density: 0.907 g / cm ³ , melt index (1
90 ° C., load 2.16 kg): 3.3 g / 10 minutes Component (d): Propylene homopolymer PP CJ700 (trademark) manufactured by Mitsui Petrochemical Industries, Ltd. Crystallinity: Tm 166 ° C., ΔHm 82 mJ / mg component (E): Inorganic filler Calcium carbonate, RS400 (trademark) manufactured by Sankyo Seiko Co., Ltd. Component (f): Organic peroxide Kayaku AD (trademark) manufactured by Akzo Co., Ltd. Other components (g) Crosslinking assistant: Shinnakamura NK Ester 3G (trademark) manufactured by Chemical Co., Ltd. (h) Antioxidant: Ir manufactured by Ciba-Geigy Japan
ganox B220 (trademark)

[0043]

Examples 1 to 5 and Comparative Examples 1 to 10 The components (parts by weight) shown in Tables 1 and 3 were used. First, component (a),
(B), (d), (e) and (h) in total and component (c)
(The amount described before the “+” symbol in Tables 1 and 3) was put into a twin-screw extruder having an L / D of 62.5 at a time and the kneading temperature was 180 to 240 ° C. and the screw rotation number was 350 rpm.
The melt kneading was started at m. Next, components (f) and (g)
Was side-fed and melt kneading was continued. Subsequently, the remainder of the component (c) (the amount described after the “+” symbol in Tables 1 and 3) was side-fed, melt-kneaded, and pelletized. The obtained pellets are placed in a predetermined mold, and
Pressing was performed under the conditions of 0 ° C. and 50 kg / cm ² to prepare respective sheets for the evaluation methods (1) to (8). Regarding the evaluation methods (9) to (11), the pellets obtained as described above were injection-molded under the conditions described in the evaluation method (9) and subjected to the respective tests.

The results are shown in Tables 2 and 4.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4] Example 1 is a resin composition produced by the method of the present invention, while Comparative Example 1 was the same as Example 1 except that components (f) and (g) were not added. In Comparative Example 1, it was found that the oil resistance was extremely low. Also, D
From the results of the SC measurement, in Example 1, the melting temperature (Tm ₁ ) of polyethylene decreased, and the melting (Tm ₂ ) of polypropylene disappeared. Polyethylene, polypropylene crystallization temperature (Tc _1, Tc ₂₎ is small but was reduced. Thus, in Example 1, it is considered that some interaction between polyethylene and polypropylene occurred, and a state close to partial compatibility occurred. Further, the glass transition point (Tg ₁ ) increased in Example 1 and became remarkable. This is considered to be because the crystal-amorphous phase separation of polyethylene became remarkable by the method of the present invention.

In Examples 2 to 4, the amount of component (c) was varied. All exhibited good characteristic values. Also, it was found that each characteristic value became better when the blending amount was increased. Example 5 does not contain component (e). Similarly, good characteristic values were shown.

On the other hand, in Comparative Example 2, the addition amount of the component (b) was less than the range of the present invention. The tensile elongation was very small, and the moldability was poor. In Comparative Example 3, the amount of component (b) added exceeded the range of the present invention. The tensile elongation was very small, and bleed out was remarkable. In Comparative Example 4, the amount of the component (c) added was less than the range of the present invention, and the components were combined at the same time in the kneading in the former stage. The tensile elongation was very small, and the moldability was poor. In Comparative Example 5, the amount of component (c) added exceeded the range of the present invention. Bleed-out was poor.
In Comparative Example 6, the component (d) was not blended.
The tensile elongation was extremely low, and the moldability was poor. In Comparative Example 7, the amount of component (d) added exceeded the range of the present invention. The tensile elongation was small and the bleed out property was poor. In Comparative Example 8, the amount of component (e) added exceeded the range of the present invention. Tensile elongation, tear strength, rebound resilience, oil resistance were poor, and moldability was also poor. Comparative Example 9
Is obtained by melting and kneading all the components at the same mixing ratio as in Example 1. Compared with Example 1, the tensile strength and the tensile elongation are lower. It was also found that the hardness was increased and the flexibility was reduced. Comparative Example 10 uses ordinary polyethylene which was not polymerized with a single-site catalyst, instead of component (c) of Example 1. Compared with Example 1, it was also found that the tensile elongation was low, the hardness was high, and the flexibility was low. It was also found that the gloss was significantly reduced, and the gloss of the surface of the molded article was significantly deteriorated. This is considered to be due to poor dispersibility of the resin as compared with Example 1.

[0051]

The present invention has excellent flexibility, heat deformation resistance,
Provided is a method for producing a thermoplastic elastomer composition having excellent mechanical strength and moldability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 23/04 C08L 23/04 23/10 23/10 (56) References JP-A-10-310617 (JP, A) JP JP-A-8-231817 (JP, A) JP-A-9-316285 (JP, A) JP-A-8-225713 (JP, A) Japanese Translation of PCT International Publication No. 10-501285 (JP, A) International publication 95/27756 (WO, A1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 53/02 C08J 3/20 C08K 3/00 C08K 5/01 C08K 5/14 C08L 23/04 C08L 23/10

Claims (4)

(57) [Claims] 1. A block copolymer comprising (a) at least two polymer blocks A mainly made of a vinyl aromatic compound and at least one polymer block B mainly made of a conjugated diene compound, and / or ,
Block copolymer obtained by hydrogenating this 100
Parts by weight, (b) a non-aromatic rubber softener 40 to 24
0 parts by weight, (c) polymerized with a single-site catalyst,
Polyethylene or copolymer based on ethylene 5
300 parts by weight, (d) 5 to 60 parts by weight of a copolymer mainly composed of polypropylene or propylene, and (e) 0 to 100 parts by weight of an inorganic filler are melt-kneaded to produce a thermoplastic elastomer composition. (I) The total amount of the components (a), (b), (d) and (e) and the component (c)
And a part of the mixture is previously melt-kneaded and then or simultaneously (f)
A method characterized by melt-kneading with an organic peroxide, and then (II) melt-kneading the obtained melt-kneaded product and the remainder of the component (c). 2. The process according to claim 1, wherein the weight ratio of component (c) used in steps (I) and (II) is 90:10 to 10:90. 3. The process according to claim 1, wherein component (f) is used in an amount of 0.1 to 1.5 parts by weight based on 100 parts by weight of the total of components (a) to (d). 4. A component (f) together with (g) a crosslinking aid in an amount of 0.1 to 100 parts by weight based on a total of (a) to (d).
The production method according to any one of claims 1 to 3, wherein the step (I) is performed using 3.5 parts by weight.