JP2020055981A - Thermoplastic elastomer composition and joining member - Google Patents

Abstract

To provide a joining member composed of a thermoplastic elastomer composition having excellent slidability and fusibility to an extrusion material and having flowability suitable for injection molding.SOLUTION: There is provided a joining member composed of a thermoplastic elastomer composition which comprises the following components (A), (B) and (C) and 17 to 50 pts.mass of the component (A) based on the total 100 pts.mass of the components (A) to (C). Component (A): a modified polypropylene having a melt flow rate of 0.1 to 250 g/10 min (according to JIS K7210, at 230°C, 21.2 N load), a melt tension of 1.0 to 20 cN and a melting point of 157°C or less which exhibits strain hardenability, Component (B): a hydrogenated block copolymer comprising at least 2 polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene or isobutylene, and Component (C): a hydrocarbon-based rubber softener.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermoplastic elastomer composition, a joining member made of the thermoplastic elastomer composition, a method for producing the same, and a composite molded article for automobiles using the joining member. Specifically, a thermoplastic elastomer composition having excellent slidability and fusion property with an extruded material and having fluidity suitable for injection molding, a joining member made of this thermoplastic elastomer composition, a method for producing the same, The present invention relates to a composite molded article for automobiles using a joining member.

  A thermoplastic elastomer composition obtained by melt-kneading a polypropylene resin and a styrene-butadiene block copolymer does not require a vulcanization step while exhibiting properties as a rubber-like soft material, and is similar to a thermoplastic resin. It has a moldability. For this reason, such thermoplastic elastomer compositions are attracting attention from the viewpoints of rationalization of manufacturing processes, recyclability, and the like, and are widely used in the fields of automobile parts, home appliances, medical equipment parts, electric wires, miscellaneous goods, and the like. . In particular, the thermoplastic elastomer composition has been frequently used in applications as a sealing material for automobiles and a sealing material for building materials.

  Since a sealing material for automobiles and a sealing material for building materials have a complicated structure, members made of a thermoplastic elastomer composition are usually joined together to produce a desired member. At this time, in order to join the molded articles made of the thermoplastic elastomer composition, as a technique of joining without using an adhesive or the like, for example, as described in Patent Document 1, olefin copolymer rubber and There is known a technique in which a mineral oil-based rubber softener and a polypropylene-based resin are mixed at a fixed ratio and thermally fused by a dynamically cross-linked joining member.

  Patent Document 2 discloses an olefin copolymer rubber and crystalline ethylene as a technique for obtaining a thermoplastic elastomer as a joint corner member for a composite molded article for automobiles that sufficiently fuses vulcanized rubber molded articles. There is disclosed a technique of mixing a system copolymer and a polypropylene resin at a fixed ratio to dynamically crosslink.

JP 2008-266615 A JP 2003-155386 A

  In recent years, as a joining member of a composite molded article for automobiles made of a thermoplastic elastomer composition, it is required to have excellent slidability, fusion property with an extruded material, and good moldability (fluidity). .

Although the joining member made of the thermoplastic elastomer composition described in Patent Document 1 has good adhesiveness to an elastomer molded article, Patent Document 1 discloses a sliding member required as a joining member for a composite molded article for automobiles. No mention of mobility.
Generally, when a lubricant such as silicone oil or oleic amide is added, high slidability can be obtained. However, such a lubricant has a low surface tension and is exposed to an adhesive surface with a molded product to improve the fusibility. May cause a decrease.
Further, in Patent Document 1, since a low-flow propylene homopolymer (MFR: 0.7 g / 10 min (230 ° C., 21.18 N)) is used as the polypropylene resin, the flowability is low. And the injection moldability was insufficient.
The joining member made of the thermoplastic elastomer composition described in Patent Document 2 has good adhesiveness to a vulcanized rubber molded product, but also in Patent Document 2, a sliding member required as a joining member for a composite molded product for automobiles. No mention of mobility.

  As described above, in the related art, a thermoplastic elastomer composition having all of the slidability, the fusibility, and the molding processability in a well-balanced manner and suitable as a joining member of a composite molded article for automobiles has not been provided. .

  The present invention has been made in view of the above problems, and has excellent slidability and fusing property, and has good moldability and a thermoplastic elastomer composition, and comprises the thermoplastic elastomer composition. An object of the present invention is to provide a joining member, a method of manufacturing the same, and a composite molded article for automobiles using the joining member.

  The present inventor has found that when a modified polypropylene having a specific fluidity and a melting point of not more than a predetermined value and showing a strain hardening property and a hydrogenated product of a styrene-butadiene-based block copolymer are used in combination, a melt with an extruded material is obtained. The present inventors have obtained a novel finding that has not been known at all and found that the above-mentioned problem can be solved, and that the present invention has been completed.

  That is, the gist of the present invention is as follows.

[1] A thermoplastic elastomer composition containing the following (A), (B) and (C), and containing 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C). A joining member.
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber

[2] A composite molded article for automobiles, comprising the joining member according to [1].

[3] A thermoplastic elastomer composition containing the following (A), (B) and (C), and 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C). For producing a joining member by melt-kneading and kneading the mixture.
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber

[4] A thermoplastic elastomer composition containing the following (A), (B) and (C) and containing 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C). .
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber

The thermoplastic elastomer composition of the present invention has excellent slidability and fusibility, has good moldability, and has excellent slidability and fusibility using the thermoplastic elastomer composition of the present invention. A joining member for a composite molded article can be obtained with good moldability.
The joining member made of the thermoplastic elastomer composition of the present invention is useful as a sealing material for automobiles and a sealing material for building materials because of its excellent slidability, fusing property and moldability. It is useful as a joining member for a composite molded article for automobiles.

It is a perspective view showing an example of a glass run channel for vehicles to which the present invention is applied.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following description, and can be arbitrarily modified and implemented without departing from the gist of the present invention. In addition, in this specification, when a numerical value or a property value is inserted before and after using “to”, it is used as including the values before and after.

(Thermoplastic elastomer composition)
The thermoplastic elastomer composition of the present invention is characterized by containing at least the following components (A) to (C) at a predetermined ratio.
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber

[mechanism]
Advantageous Effects of Invention The thermoplastic elastomer composition of the present invention has an effect of being excellent in slidability and fusibility and good in moldability.

Although the details of the reason why the thermoplastic elastomer composition of the present invention exhibits such an effect are not clear, since the component (A) -modified polypropylene has a comb-like structure having a branched chain, the extrusion partner which is a fusion partner is used. It is considered that the entanglement of the molecule with the resin component of the material was promoted, and the fusing property was improved. Further, since the component (A) modified polypropylene has a high viscosity and the dispersion diameter of the component (B) styrene-based hydrogenated block copolymer can be finely dispersed by a strong shearing action, the surface of the molded article becomes smoother and good sliding is obtained. It is estimated that mobility was obtained.
Further, since the styrene-based hydrogenated block copolymer (B), which is a rubber component of the thermoplastic elastomer composition of the present invention, mainly contains a vinyl aromatic compound unit, more rubbers are used as compared with olefin-based rubbers. The composition can contain a softening agent for use, and the fluidity required for injection molding can be obtained, and the moldability can be improved.

  Conventionally, as in Patent Documents 1 and 2 described above, a method of using an ethylene / α-olefin-based copolymer rubber to improve the fusibility of a molded article obtained is generally well known, The technology of satisfying the slidability and the fusibility and further improving the moldability by the combination of the hydrogenated product of the block copolymer mainly composed of the polypropylene and the vinyl aromatic compound unit has been developed by the present invention. It was established for the first time.

<Component (A)>
The modified polypropylene of the component (A) is a strain-hardening polypropylene resin (a homopolymer of propylene or a propylene copolymer, hereinafter sometimes referred to as a “propylene (co) polymer”). is there. Here, "strain hardening" means a phenomenon in which the viscosity increases as the stretching strain of the melt increases, and in the present invention, the presence or absence of "strain hardening" is determined by measuring the melt tension under the conditions described below. Can be determined from the fracture behavior of the molten strand of Example 1. When the take-up speed is increased, the take-up load increases rapidly, and when cutting occurs, it is determined that the material exhibits strain hardening.

  Modified polypropylene exhibiting the strain hardening property of the component (A) has a melting point of 157 ° C. or lower and a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2N, JIS K7210), and It has a melt tension of 1.0 to 20 cN.

The fusion between the adherend and the olefin-based resin composition or the elastomer composition containing the olefin-based resin depends on the melting point of the adherend. A lower one is advantageous in terms of the fusibility and is preferred. The melting point of the modified polypropylene exhibiting the strain hardening property of the component (A) is preferably 157 ° C. or lower, more preferably 156 ° C. or lower. On the other hand, it is usually 120 ° C. or higher from the viewpoint of heat resistance.
Here, the melting point of the modified polypropylene exhibiting the strain hardening property is a melting peak temperature measured by a differential scanning calorimeter.

  The MFR of the modified polypropylene exhibiting the strain hardening property of the component (A) is preferably from 0.3 g / 10 min to 100 g / 10 min, more preferably from 0.5 g / min, from the viewpoint of moldability and the like. It is 10 minutes or more and 70 g / 10 minutes or less. In particular, from the viewpoint of compression set, the MFR of the modified polypropylene exhibiting the strain hardening property of the component (A) is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, and most preferably 10 g / 10 min. It is as follows. Here, the MFR of the modified polypropylene exhibiting the strain hardening property of the component (A) is a value measured at 230 ° C. and a load of 2.12 N according to JIS K7210.

  The melt tension of the modified polypropylene exhibiting the strain hardening property of the component (A) is more preferably from 1.5 to 19 cN, and still more preferably from 2.0 to 18 cN, from the viewpoint of moldability and compression set. And particularly preferably 2.5 to 15 cN.

Here, the method for measuring the melt tension is as follows.
That is, a capillograph (manufactured by Toyo Seiki Seisakusho) equipped with a melt tension measurement attachment and having a φ10 mm cylinder with a φ1 mm or 10 mm long orifice at the tip is used at 230 ° C. and a piston descent speed of 10 mm / The strand discharged from the die when it is lowered in minutes is pulled on a pulley with a load cell below 350 mm at a speed of 1 m / min, and after stabilization, the take-up speed is increased at a rate of reaching 200 m / min in 4 minutes. The load applied to the pulley with a load cell when the strand was broken was measured, and the measured load was used as the melt tension.

The type of the modified polypropylene exhibiting the strain hardening property of the component (A) is not particularly limited, and a propylene-based polymer such as a propylene homopolymer, a block copolymer of propylene and another copolymer component, or a random copolymer is used. Any of the copolymers can be used. Here, the propylene-based copolymer means one having a propylene unit content of more than 50% by mass. From the viewpoints of heat resistance, rigidity, crystallinity, chemical resistance, and the like, the content of the propylene unit in the propylene-based copolymer is preferably 60% by mass or more, more preferably 75% by mass or more, and further preferably 90% by mass. % Or more. On the other hand, the upper limit of the content of the propylene unit is not particularly limited, but is usually less than 100% by mass.
The contents of the propylene unit in the component (A) and the constituent units of the other copolymer components described below can be determined by infrared spectroscopy.

  When the modified polypropylene of the component (A) exhibiting the strain hardening property is a propylene-based block copolymer or a random copolymer, the other copolymerizable components copolymerized with propylene include ethylene, 1-butene, and 1-butene. Α- having 2 or 4 to 12 carbon atoms such as butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. Olefin; cyclic olefin such as cyclopentene, norbornene, tetracyclo [6,2,11,8,13,6] -4-dodecene; 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 1,4-hexadiene And diene such as methyl-1,4-hexadiene and 7-methyl-1,6-octadiene; vinyl chloride, vinylidene chloride, acrylonitrile Vinyl acetate, acrylic acid, methacrylic acid, maleic acid, ethyl acrylate, butyl acrylate, methyl methacrylate, maleic anhydride, styrene, methyl styrene, vinyl toluene, vinyl monomers such as divinylbenzene, and the like, It is not particularly limited to these. One of these other copolymer components may be used alone, or two or more thereof may be used in any combination and ratio. Among these, ethylene and 1-butene are preferred.

  Here, when the component (A) is a propylene-based block copolymer, a propylene-based block copolymer obtained by performing polymerization in multiple stages is preferable. For example, a propylene-based block copolymer obtained by polymerizing polypropylene in the first step and polymerizing a propylene-ethylene copolymer in the second step is preferably used.

  Further, as the component (A), a propylene-based (co) polymer having a branched structure, a propylene-based (co) polymer having a high molecular weight component, and the like are also preferably used. Examples of such a propylene (co) polymer include linear propylene homopolymers, propylene homopolymers, block copolymers, and random copolymers obtained by irradiating a linear polypropylene resin with radiation. Examples include a crystalline propylene (co) polymer obtained by melt-mixing a polypropylene resin, a conjugated diene compound, and a radical polymerization initiator. Among these, those having a branched structure are preferable.

  The method for producing the modified polypropylene exhibiting the strain-hardening property of the component (A) is not particularly limited, and for example, a known polymerization method using a known olefin polymerization catalyst can be used. A multi-stage polymerization method using a Ziegler-Natta catalyst can be used. For this multi-stage polymerization method, a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method, or the like can be used, and a combination of two or more thereof may be used.

  The modified polypropylene exhibiting the strain hardening property of the component (A) used in the present invention preferably has a long-chain branched structure.

For the long-chain branched structure, Macromol. Chem. Phys. 2003, vol. 204 and 1738, which are described in detail below.
The propylene-based (co) polymer having a long-chain branched structure has a specific branched structure as shown in the following structural formula (1). In the structural formula (1), Ca, Cb, and Cc represent a methylene carbon adjacent to the branched carbon, Cbr represents a methine carbon at the base of the branched chain, and P1, P2, and P3 are propylene (co) carbons. Shows the coalescing residue.
P1, P2, and P3 may themselves contain another branched carbon (Cbr) different from the Cbr described in the structural formula (1).

Such a branched structure is identified by ¹³ C-NMR analysis. Assignment of each peak is described in Macromolecules, Vol. 35, no. 10. The description on pages 3839-3842 of 2002 can be referred to. That is, a total of three methylene carbons (Ca, Cb, Cc) were observed at 43.9 to 44.1 ppm, 44.5 to 44.7 ppm, and 44.7 to 44.9 ppm, and 31.5 to 31.5 ppm. Methine carbon (Cbr) is observed at ３１31.7 ppm. The methine carbon observed at 31.5 to 31.7 ppm is sometimes referred to as a branched methine carbon (Cbr).
It is characterized in that three methylene carbons close to the branched methine carbon Cbr are observed unequally divided into three diastereotopic topics.

Such a branched chain assigned by ¹³ C-NMR indicates a propylene (co) polymer residue having 5 or more carbon atoms branched from the main chain of the propylene (co) polymer, and a propylene (co) polymer residue having 4 or less carbon atoms. Can be distinguished from each other by the difference in the peak position of the branched carbon. In the present invention, the presence or absence of the long-chain branched structure can be determined by confirming the peak of the branched methine carbon.
The method for measuring ¹³ C-NMR in the present invention is as follows.

( ^13C -NMR measurement method)
NMR sample having an inner diameter of 10 mmφ with 200 mg of a sample together with 2.4 ml of o-dichlorobenzene / deuterated bromobenzene (C ₆ D ₅ Br) = 4/1 (volume ratio) and hexamethyldisiloxane as a chemical shift reference substance Dissolve in a tube and perform ¹³ C-NMR measurement.
^{The 13} C-NMR measurement is performed using a Bruker BioSpin KK AV400M NMR apparatus equipped with a 10 mmφ cryoprobe.
The measurement is performed at a sample temperature of 120 ° C. by a proton complete decoupling method. Other conditions are as follows.
Pulse angle: 90 °
Pulse interval: 4 seconds Number of times of integration: 20000 times The chemical shift was set with the methyl carbon peak of hexamethyldisiloxane being 1.98 ppm, and the chemical shift of the peak due to other carbons was based on this.
Using the peak around 44 ppm, the amount of long-chain branching can be calculated.

The modified polypropylene having a long-chain branched structure according to the present invention has a long-chain branching amount quantified from a peak near 44 ppm of a ¹³ C-NMR spectrum of 0.01 / 1000 total propylene (total 1000 skeleton-forming carbons). Per) or more, more preferably at least 0.03 / 1000 total propylene, even more preferably at least 0.05 / 1000 total propylene, preferably at most 1.00 / 1000 total propylene, more preferably Is not more than 0.50 / 1000 total propylene, and more preferably not more than 0.30 / 1000 total propylene. Within this range, a polypropylene resin having no or little gel and a high degree of strain hardening can be obtained.

  Further, the modified polypropylene having a long-chain branched structure according to the present invention has a branching index g ′, which is known as a direct index for long-chain branching, at an absolute molecular weight of 1,000,000 Mabs, with a lower limit of 0.3 or more in a preferred order, It is 0.55 or more, 0.75 or more, and 0.78 or more, and the upper limit is less than 1.0, 0.98 or less, 0.96 or less, and 0.95 or less in the order of preference. The above lower limit and upper limit can be any combination. When the branching index g 'is in the range between any of the above-mentioned preferable lower limits and any of the above-mentioned preferable upper limits, a highly cross-linked component is not formed, which is preferable in terms of molded appearance. The most preferable range of the branching index g 'in the present invention is a range of 0.78 or more and 0.95 or less.

The branching index g 'is known as a direct index for long-chain branching. The branching index g 'is described in detail in "Development in Polymer Characterization-4" (JV Dawkins ed. Applied Science Publishers, 1983), and its definition is as follows.
Branching index g ′: [η] br / [η] lin
[Η] br: Intrinsic viscosity of polymer (br) having long-chain branched structure [η] lin: Intrinsic viscosity of linear polymer having the same molecular weight as polymer (br)

  As is clear from the above definition, when the branching index g ′ takes a value smaller than 1, it is determined that a long-chain branching structure exists, and the value of the branching index g ′ decreases as the number of long-chain branching structures increases. .

  The branching index g 'can be obtained as a function of the absolute molecular weight Mabs by using GPC equipped with a light scatterometer and a viscometer in the detector. The method of measuring the branching index g 'in the present invention is described in detail in JP-A-2015-40213, and is as follows.

<Measurement method>
GPC: Alliance GPCV2000 (Waters)
Detector: described in connection order Multi-angle laser light scattering detector (MALLS): DAWN-E (Wyatt Technology)
Differential refractometer (RI): GPC attached Viscometer: GPC attached Mobile phase solvent: 1,2,4-trichlorobenzene (Irganox 1076 added at a concentration of 0.5 mg / mL)
Mobile phase flow rate: 1 mL / min Column: Tosoh Corporation GMHHR-H (S) Two HTs connected Sample injection part temperature: 140 ° C
Column temperature: 140 ° C
Detector temperature: 140 ° C for all
Sample concentration: 1 mg / mL
Injection volume (sample loop volume): 0.2175 mL

<Analysis method>
In order to obtain the absolute molecular weight (Mabs) obtained from a multi-angle laser light scattering detector (MALLS), the root mean square radius (Rg), and the intrinsic viscosity ([η]) obtained from a Visometer, data processing attached to MALLS was used. The calculation is performed using the software ASTRA (version 4.73.04) with reference to the following literature.
References:
1. "Developments in Polymer Characterization-4" (JV Dawkins ed. Applied Science Publishers, 1983. Chapter 1.)
2. Polymer, 45, 6495-6505 (2004).
3. Macromolecules, 33, 2424-2436 (2000)
4. Macromolecules, 33, 6945-6952 (2000).

  Such a modified polypropylene having a long-chain branched structure and exhibiting a strain-hardening property is produced by a method using a macromer copolymerization method in which a long-chain branched structure is formed during polymerization. Examples of this method include, for example, JP-T-2001-525460, JP-A-10-338717, JP-T-2002-523575, JP-A-2009-57542, JP05507353, and JP-A-1027353. And the method disclosed in JP-A-338717. In particular, the macromer copolymerization method disclosed in JP-A-2009-57542 is suitable for the present invention.

  In addition, as the modified polypropylene exhibiting the strain hardening property of the component (A), many grades of various grades are commercially available from manufacturers in Japan and overseas, and commercially available products can be used. Examples of commercially available products include Prim Polypro (registered trademark) manufactured by Prime Polymer, Sumitomo Noblen (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., a polypropylene block copolymer manufactured by Sun Allomer Co., and Novatec (registered trademark) PP manufactured by Nippon Polypropylene Corporation. , Waymax (registered trademark), Mollen (registered trademark) manufactured by Lyondell Basel, ExxonMobil PP manufactured by ExxonMobil, Formoline (registered trademark) manufactured by Formosa Plastics, Inc., and Borealis manufactured by Borealis SEETEC PP, A. Schulman Inc. of ASI POLYPROPYLENE, INEOS Olefins & Polymers, Inc. of INEOS PP, Braskem manufactured by Braskem PP, SAMSUNG TOTAL PETROCHEMICALS Co., Ltd. of Sumsung Total, Sabic manufactured by Sabic (registered trademark) PP, TOTAL PETROCHEMICALS Co., Ltd. TOTAL PETROCHEMICALS Polypropylene And SK Corporation's YUPLENE (registered trademark). Among them, Waymax is preferably used as a polypropylene having a long-chain branched structure and showing strain hardening properties.

  The lower limit of the content of the component (A) in the thermoplastic elastomer composition of the present invention is usually 17 parts by mass with respect to the total amount of the components (A) to (C) of 100 parts by mass from the viewpoint of fusing property. Or more, preferably 18 parts by mass or more, more preferably 19 parts by mass or more. The upper limit of the content of the component (A) is usually 50 parts by mass or less, preferably 45 parts by mass, from the viewpoint of flexibility, based on 100 parts by mass of the total of the components (A) to (C). Or less, more preferably 40 parts by mass or less.

  In addition, as the component (A), only one type can be used alone, or two or more types can be used in an arbitrary combination and ratio.

[Component (B)]
The component (B) used in the thermoplastic elastomer composition of the present invention comprises at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene. (Hereinafter, sometimes referred to as “hydrogenated block copolymer”).

  The vinyl aromatic compound as a monomer constituting the block P of the hydrogenated block copolymer is not limited, but styrene and / or styrene derivatives such as α-methylstyrene are preferred. Especially, it is preferable to use styrene as a main component. Note that the block P may contain a monomer other than the vinyl aromatic compound as a raw material.

  The block Q may contain a monomer other than butadiene, for example, isoprene as a raw material.

  The weight ratio of the block P in the hydrogenated block copolymer of the component (B) is not limited, but is preferably 5% by mass, more preferably 10% by mass or more, while 55% by mass or less. Preferably, it is 50% by mass or less, more preferably 45% by mass or less. When the weight ratio of the block P is in the above range, the balance between heat resistance and flexibility tends to be good.

  The chemical structure of the hydrogenated block copolymer of the component (B) may be linear, branched or radial, and the hydrogenated block copolymer represented by the following formula (1) or (2) may be used. It is preferably a polymer, and more preferably a structure represented by the following formula (1) from the viewpoint of improving mechanical strength.

P- (Q-P) m (1)
(PQ) n (2)
(Where P represents a block P, Q represents a block Q, m represents an integer of 1 to 5, and n represents an integer of 2 to 5)

  In the formula (1) or (2), m and n are preferably large in terms of lowering the order-disorder transition temperature as a rubbery polymer, but are preferably small in terms of ease of production and cost. . In the present invention, those in which m and n are given by integers of 1 to 5 are preferable, and 2 to 4 are more preferable.

  As the hydrogenated block copolymer of the component (B), a hydrogenated block copolymer which is excellent in rubber elasticity is preferable, and a hydrogenated block copolymer represented by the formula (1) in which m is 3 or less. Is more preferable, and the hydrogenated block copolymer represented by the formula (1) wherein m is 2 or less is further preferable.

  Although the number average molecular weight of the hydrogenated block copolymer of the component (B) is not limited, it may be 100000 or more as a value in terms of polystyrene measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC). Preferably, it is more preferably 150,000 or more, further preferably 200,000 or more, preferably 600,000 or less, more preferably 550,000 or less, and still more preferably 500,000 or less.

  The method for producing the hydrogenated block copolymer of the component (B) in the present invention may be any method as long as the above-mentioned structure and physical properties can be obtained, and are not particularly limited. Specifically, for example, it can be obtained by performing block polymerization using a lithium catalyst or the like by the method described in JP-A-7-97493. The hydrogenation (hydrogenation) of the block copolymer can be carried out, for example, by a method described in JP-A-59-133203 or the like in an inert solvent in the presence of a hydrogenation catalyst.

  Commercial products of the hydrogenated block copolymer of the component (B) include “TAIPOL-6151” and “TAIPOL-6159” manufactured by Taiwan Synthetic Rubber (TSRC), “G1651” and “G1633” manufactured by Clayton Polymer Japan Ltd. And "Septon 4099" manufactured by Kuraray Co., Ltd.

  As the component (B), only one type may be used, or two or more types having different compositions and physical properties may be used in combination.

  In the method for producing a thermoplastic elastomer composition of the present invention, the lower limit of the content of the component (B) is usually from 34 to 100 parts by mass of the total of the components (A) to (C) from the viewpoint of moldability. Not less than 35 parts by mass, more preferably not less than 36 parts by mass. On the other hand, the upper limit is usually 60 parts by mass or less, preferably 59 parts by mass or less, and more preferably 58 parts by mass or less.

[Component (C)]
Component (C) used in the thermoplastic elastomer composition of the present invention is a softener for hydrocarbon rubber.

  The lower limit of the content of the component (C) in the thermoplastic elastomer composition of the present invention is usually 80 parts by mass or more, preferably 81 parts by mass, from the viewpoint of moldability, based on 100 parts by mass of the component (B). And more preferably at least 82 parts by mass. Further, the upper limit of the content of the component (C) is usually 102 parts by mass or less, preferably 101 parts by mass or less, more preferably 100 parts by mass, from the viewpoint of flexibility, with respect to 100 parts by mass of the component (B). Not more than parts by mass.

  Examples of the hydrocarbon rubber softener of the component (C) include a mineral oil softener and a synthetic resin softener, but a mineral oil softener is preferable from the viewpoint of affinity with other components. The mineral oil-based softener is generally a mixture of an aromatic hydrocarbon, a naphthenic hydrocarbon and a paraffinic hydrocarbon, and a paraffinic oil in which 50% or more of all carbon atoms are paraffinic hydrocarbons, Those in which 30 to 45% of all carbon atoms are naphthenic hydrocarbons are called naphthenic oils, and those in which 35% or more of all carbon atoms are aromatic hydrocarbons are called aromatic oils. Among them, in the present invention, it is preferable to use a paraffinic oil.

  The kinematic viscosity at 40 ° C. of the hydrocarbon rubber softener of the component (C) is not particularly limited, but is preferably 20 cSt or more, more preferably 50 cSt or more, and preferably 800 cSt or less, more preferably 600 cSt or less. is there. The flash point (COC method) of the softening agent for hydrocarbon rubber is preferably 200 ° C. or higher, more preferably 250 ° C. or higher.

  The hydrocarbon rubber softener of the component (C) can be obtained as a commercial product. Examples of the corresponding commercially available products include “Nisseki Polybutene (registered trademark) HV” series manufactured by JX Nippon Oil & Energy Corporation and “Diana (registered trademark) process oil PW” series manufactured by Idemitsu Kosan Co., Ltd. Appropriate products can be selected and used from among them.

  As the hydrocarbon-based rubber softener of the component (C), only one kind may be used, or two or more kinds may be used in optional combination and ratio.

[Other ingredients]
In the production of the thermoplastic elastomer composition of the present invention, other components can be used as a raw material, if necessary, in addition to the components (A) to (C) as long as the effects of the present invention are not impaired.

  Other components include, for example, resins such as thermoplastic resins and elastomers other than the components (A) and (B), antioxidants, fillers, heat stabilizers, light stabilizers, ultraviolet absorbers, and neutralizers. , Lubricants, anti-fog agents, anti-blocking agents, slip agents, dispersants, coloring agents, flame retardants, antistatic agents, conductivity-imparting agents, metal deactivators, molecular weight regulators, germicides, fungicides, Various additives such as a fluorescent whitening agent and a crosslinking agent can be exemplified. Any of these can be used alone or in combination.

Examples of the thermoplastic resin other than the components (A) and (B) include polyphenylene ether resins; polyamide resins such as nylon 6 and nylon 66; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polyoxymethylene resins such as homopolymers and polyoxymethylene copolymers; polymethyl methacrylate resins, polyolefin resins, and the like.
Examples of the elastomer other than the component (A) and the component (B) include a styrene-based elastomer (however, excluding those corresponding to the component (B)); a polyester-based elastomer; and polybutadiene.

  Examples of the lubricant (hereinafter, sometimes referred to as “component (D)”) include silicone oil, silicone masterbatch, and liquid siloxane wax. When a lubricant is used, the lubricant is used in an amount of usually 0.05 to 50 parts by mass, preferably 0.1 to 10 parts by mass based on 100 parts by mass of the components (A) to (C) in total. As described above, in the present invention, the use amount of the lubricant can be suppressed by the effect of improving the slidability by the components (A) and (B), and as described above, the total amount of the components (A) to (C) can be reduced. By adding a small amount of 10 parts by mass or less with respect to 100 parts by mass, excellent slidability can be obtained while suppressing a decrease in the fusibility.

  Examples of the antioxidant (hereinafter sometimes referred to as “component (E)”) include, for example, a phenolic antioxidant, a phosphite antioxidant, and a thioether antioxidant. When an antioxidant is used, the antioxidant is used in an amount of usually 0.01 to 3.0 parts by mass, preferably 0.1 to 0.6 parts by mass, based on 100 parts by mass of the components (A) and (B) in total. Used in parts by weight. Within the above range, good thermal stability can be obtained.

  Examples of the filler include glass fiber, hollow glass sphere, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, metal soap, titanium dioxide, and carbon black. When a filler is used, the filler is usually used in an amount of 0.3 to 100 parts by mass based on 100 parts by mass in total of the components (A) to (C).

[Method for producing thermoplastic elastomer composition]
The thermoplastic elastomer composition of the present invention is preferably obtained by melt-kneading a composition containing a predetermined amount of component (A), component (B), component (C) and other components.

  In the present invention, “melt kneading” means kneading in a molten state or a semi-molten state. As the mixing and kneading apparatus for melt kneading, for example, a non-open type Banbury mixer, a mixing roll, a kneader, a twin-screw extruder and the like are used. Among these, it is preferable to use a twin-screw extruder. In a preferred embodiment of the production method using the twin-screw extruder, each component is supplied to a raw material supply port (hopper) of a twin-screw extruder having a plurality of raw material supply ports to perform melt kneading.

  The temperature at the time of performing the melt kneading is usually 80 to 300 ° C, preferably 100 to 250 ° C. The time for performing the melt kneading is usually 0.1 to 30 minutes.

When the thermoplastic elastomer composition of the present invention is produced by melt-kneading with a twin-screw extruder, the twin-screw extruder has a barrel radius (R (mm)), a screw rotation speed (N (rpm)), and It is preferable to extrude while maintaining the relationship of the following formula (I) between the discharge amounts (W (kg / hour)), and it is more preferable to extrude while maintaining the relationship of the following formula (II).
2.6 <NW / R ³ <22.6 (I)
3.0 <NW / R ³ <20.0 (II)

  It is thermoplastic that the relationship between the barrel radius (R (mm)), the screw rotation speed (N (rpm)), and the discharge rate (W (kg / h)) of the twin-screw extruder is larger than the lower limit. It is preferable for efficiently producing the elastomer composition. On the other hand, it is preferable that the above-mentioned relationship is smaller than the above-mentioned upper limit, since heat generation due to shearing is suppressed, and a foreign substance causing poor appearance is less likely to be generated.

[Physical properties of thermoplastic elastomer composition]
The thermoplastic elastomer composition of the present invention may have a melt flow rate (MFR) of 2.0 g / 10 min or more measured at a measuring temperature of 230 ° C. and a measuring load of 21.2 N by a method based on JIS K7210. It is preferable from the viewpoint of moldability, more preferably at least 2.1 g / 10 min, even more preferably at least 2.2 g / 10 min. In addition, from the viewpoint of moldability, the melt flow rate (MFR) is preferably 100 g / 10 minutes or less, more preferably 95 g / 10 minutes or less, and even more preferably 90 g / 10 minutes or less. , 60 g / 10 min or less.

[Molded object / use]
The thermoplastic elastomer composition of the present invention can be formed into a molded article by various molding methods usually used for the thermoplastic elastomer composition, for example, injection molding, extrusion molding, hollow molding, compression molding and the like. Of these, injection molding is preferred. In addition, a molded article that has been subjected to secondary processing such as lamination molding and thermoforming after performing these moldings can also be used.

Molded articles made of the thermoplastic elastomer composition of the present invention include automobile parts such as skins, weather strips, ceiling materials, interior sheets, bumper moldings, side moldings, air spoilers, air duct hoses, sealing materials, etc .; Civil engineering and construction materials such as window frames, seals, etc .; Sports equipment such as grips for golf clubs and grips for tennis rackets; Industrial parts such as hose tubes and gaskets; Home appliance parts such as hoses and packings; Medical parts such as containers, gaskets and packings; food parts such as containers and packings; medical equipment parts; electric wires;
The molded article made of the thermoplastic elastomer composition of the present invention is suitable as a sealing material for automobiles and a sealing material for building materials among the above-mentioned ones, and is also suitable as a sealing material for automobiles, particularly a glass run channel for automobiles.

(Joint members)
The joining member of the present invention comprises the above-described thermoplastic elastomer composition of the present invention, and is produced by melt-kneading the thermoplastic elastomer composition of the present invention and injection-molding the kneaded product.

In particular, the joining member of the present invention is suitable as a joining member used for an automobile composite molded article such as an automobile glass run channel.
FIG. 1 is a perspective view showing an example of a glass run channel for an automobile as a composite molded article 3 for an automobile, and extruded members 1A and 1B constituting a linear portion separately manufactured by extrusion molding of a thermoplastic elastomer composition. Are fused and integrated at a corner portion made of the joining member 2 of the present invention.

  In such a composite molded article 3, for example, the joining end sides of the extruded members 1A and 1B manufactured in advance are inserted into an injection molding die, and the thermoplastic elastomer composition of the present invention is injected into the die. It can be manufactured by molding to form the joining member 2 at the corner portion, and by fusing and integrating with the end faces of the extruded members 1A and 1B.

  The thermoplastic elastomer composition constituting the extruded members 1A and 1B is not particularly limited, but has excellent fusion property with the thermoplastic elastomer composition of the present invention, and has a mechanical property as a frame portion of a glass run channel for automobiles. Olefin-based thermoplastic elastomers and styrene-based thermoplastic elastomers are preferred because they are excellent in strength and compression set (set).

  Hereinafter, the content of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferred values of the upper limit or the lower limit in the embodiment of the present invention, and the preferred range is the value of the upper limit or the lower limit, and The range may be defined by a combination of the values of the examples or the values of the examples.

〔raw materials〕
Raw materials used in the following Examples and Comparative Examples are as follows.

[Component (A) for Examples]
<A-1>
"WAYMAX MFX8" manufactured by Nippon Polypropylene Co., Ltd.
Melting point: 155 ° C
MFR (230 ° C, 21.2N): 1g / 10min Melt tension: 24cN (230 ° C)
Methylene carbon (Ca, Cb, Cc) and methine carbon (Cbr): Observed long-chain branching amount: 0.1 / 1000 total propylene (per 1,000 total skeleton-forming carbons)
Branching index g ′ at an absolute molecular weight Mabs of 1,000,000: 0.89
<A-2>
"WAYMAX MFX3" manufactured by Nippon Polypropylene Co., Ltd.
Melting point: 154 ° C
MFR (230 ° C, 21.2N): 8g / 10min Melt tension: 5cN (230 ° C)
Methylene carbon (Ca, Cb, Cc) and methine carbon (Cbr): Observed long-chain branching amount: 0.2 / 1000 total propylene (per 1,000 total skeleton-forming carbons)
Branching index g ′ at an absolute molecular weight Mabs of 1,000,000: 0.87

[Component (a) for Comparative Example]
<A-1>
Propylene-ethylene random copolymer "Novatech (registered trademark) PP EG7F" manufactured by Japan Polypropylene Corporation
MFR (230 ° C., 21.2 N): 1.3 g / 10 min Melting point: 149 ° C.
Propylene unit content: 98% by mass

[Component (B)]
<B-1>
Styrene-butadiene-styrene hydrogenated block copolymer (having the structure of the above formula (1)) "TAIPOL-6151" manufactured by Taiwan Synthetic Rubber (TSRC)
Styrene (block P) content: 32% by mass
Number average molecular weight: 220,000

[Component (C)]
<C-1>
"Diana (registered trademark) process oil PW90" manufactured by Idemitsu Kosan Co., Ltd.
Kinematic viscosity at 40 ° C .: 95.5 cSt
Pour point: -15 ° C
Flash point: 272 ° C

[Component (D)]
<D-1>
Silicone oil "KF96-1000CS" manufactured by Shin-Etsu Chemical Co., Ltd.

[Component (E)]
<E-1>
Phenolic antioxidant "Irganox (registered trademark) 1010" manufactured by BASF Japan

[Evaluation method]
The evaluation method of the thermoplastic elastomer composition in the following Examples and Comparative Examples is as follows.

  In the following measurements (1) to (5), each thermoplastic elastomer composition was used, and an injection pressure of 50 MPa and a cylinder temperature of 220 were measured using an in-line screw type injection molding machine (“IS130” manufactured by Toshiba Machine Co., Ltd.). A sheet (120 mm wide, 80 mm long, 2 mm thick) obtained by injection molding at a temperature of 40 ° C. and a mold temperature of 40 ° C. was used.

(1) Hardness duro A
According to JIS K6253 (JIS-A), the value was measured 15 seconds after the needle was pressed against the test piece.
The hardness durometer A is preferably in the range of 35 to 95, particularly preferably 40 to 98.

(2) Compression set In accordance with JIS K6262, the compression set was measured under conditions of 70 ° C., 22 hours, and 25% compression.
The following criteria were evaluated from the measured value (CS) of compression set (set).
：: CS less than 53% Δ: CS 53% or more and less than 55% ×: CS 55% or more

(3) Static friction coefficient and dynamic friction coefficient A sheet (120 mm wide, 80 mm long, 2 mm thick) obtained by injection molding was cut into a size of 60 cm × 45 cm × size, and a glass plate (110 mm × length) was placed on the test piece. The static friction coefficient and the dynamic friction coefficient were measured by moving a weight of 200 g adhered with a double-sided tape to a width of 110 mm and a thickness of 3 mm) by 6 cm. The measurement was performed three times, and the average value was calculated.
The static friction coefficient was evaluated according to the following criteria.
：: Static friction coefficient less than 3.0 △: Static friction coefficient 3.0 or more and less than 4.0 ×: Static friction coefficient 4.0 or more

(4) Fusion strength and fusion elongation with TPV (dynamic crosslinked thermoplastic elastomer) 2 mm thick injection of olefinic dynamically crosslinked thermoplastic elastomer ("TREXPRENE (registered trademark) 3855N" manufactured by Mitsubishi Chemical Corporation). The sheet was cut into a size of 10 cm × 5 cm, loaded into a mold of a 110-ton injection molding machine, and each thermoplastic elastomer composition was injected into the mold at a cylinder temperature of 210 ° C. and a mold temperature of 40 ° C., A composite molded body was obtained by the insert molding method. The composite molded body was punched out with a JIS No. 3 dumbbell, pulled at a tensile speed of 200 mm / min, and the fusion strength and fusion elongation were measured.
The fusing strength was evaluated according to the following criteria.
：: Fusing strength 4.0 MPa or more Δ: Fusing strength 3.5 MPa or more and less than 4.0 MPa ×: Fusing strength less than 3.5 MPa This evaluation is an evaluation of the fusing property using an injection sheet. From the evaluation results, it is also possible to evaluate whether or not the fusibility of the composite molded body as shown in FIG. 1 is good.

(5) Tensile breaking strength / tensile breaking elongation Measurement was performed in accordance with the procedure based on the measuring method of tensile stress at break and elongation at break according to JIS K6251.

(6) Melt flow rate (MFR)
The measurement was performed at 230 ° C. and a measurement load of 21.2 N in accordance with JIS K7210.
From the value of MFR, moldability was evaluated according to the following criteria.
：: MFR 2.0 g / 10 min or more △: MFR 1.6 g / 10 min or more and less than 2.0 g / 10 min ×: MFR 1.6 g / 10 min or less

[Examples / Comparative Examples]
<Example 1>
(A-1) 30 parts by mass, (B-1) 36 parts by mass, (C-1) 34 parts by mass, (D-1) 2 parts by mass, (E-1) 0.1 part by mass into a Henschel mixer. For 1 minute to obtain a mixture. This mixture was fed into a feed section of a co-directional twin-screw extruder (“TEX30α” manufactured by Nippon Steel Works, L / D = 46, number of cylinder blocks: 13) at a total speed of 15 kg / h, and was fed at 110 to 180 ° C. The temperature was raised within the range, melt-kneaded, and pelletized to produce a thermoplastic elastomer composition.
With respect to the obtained thermoplastic elastomer composition, the above-mentioned (1) to (6) were evaluated. Table 1 shows the evaluation results.

<Examples 2 to 5 and Comparative Examples 1 to 4>
Except having changed the composition as shown in Table 1, it carried out similarly to Example 1 and obtained the pellet of the thermoplastic elastomer composition. The same evaluation as in Example 1 was performed on the obtained thermoplastic elastomer composition. The results are shown in Table 1.

<Evaluation results>
As shown in Table 1, Examples 1 to 5 are excellent in evaluation of "slidability (static friction coefficient)" and "fusion property with extruded material", and "fluidity (MFR)" which indicates moldability. Good.

Comparative Example 1 is an example in which half of (A-1) used in Example 4 was replaced with (a-1), but "slidability (static friction coefficient)" and "fusion with extruded material" And "liquidity" are poorly evaluated.
Comparative Example 2 is an example in which the total amount of (A-2) used in Example 2 was replaced with (a-1), but "slidability (static friction coefficient)" and "fusion with extruded material" And "liquidity" are poorly evaluated.
Comparative Example 3 is an example in which the total amount of (A-1) used in Example 4 was replaced with (a-1), but "slidability (static friction coefficient)" and "fusion with extruded material" And "liquidity" are poorly evaluated.
In Comparative Example 4, the total amount of (A-2) used in Example 2 was replaced with (a-1), the amount of (a-1) was increased, and the increase (B-1) was reduced. Although it is an example, evaluations of "slidability (static friction coefficient)", "fusibility with extruded material" and "fluidity" are inferior.

  The thermoplastic elastomer composition of the present invention includes: automobile parts such as skin, weatherstrip, ceiling material, interior sheet, bumper molding, side molding, air spoiler, air duct hose, sealing material; water-blocking material, joint material, window frame, Civil engineering and building materials parts such as sealing materials; sporting goods such as grips for golf clubs and grips for tennis rackets; industrial parts such as hose tubes and gaskets; home appliance parts such as hoses and packings; medical containers and gaskets; It can be used in a wide variety of fields such as medical parts such as packing; food parts such as containers and packing; medical equipment parts; electric wires; The thermoplastic elastomer composition of the present invention is suitable as a sealant for automobiles and a sealant for building materials among the above-mentioned ones, and is also suitable as a sealant for automobiles, particularly as a glass run channel for automobiles.

DESCRIPTION OF SYMBOLS 1A, 1B Extrusion molding member 2 Joining member 3 Composite molding

Claims (4)

Joining made of a thermoplastic elastomer composition containing the following (A), (B) and (C) and containing 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C) Element.
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber   An automotive composite molded article comprising the joining member according to claim 1. Melt-kneading a thermoplastic elastomer composition containing the following (A), (B) and (C) and containing 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C). And a method for manufacturing a joining member for injection-molding a kneaded material.
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber A thermoplastic elastomer composition comprising the following (A), (B) and (C), and 17 to 50 parts by mass of the component (A) based on 100 parts by mass of the total of the components (A) to (C).
Component (A): having a melt flow rate of 0.1 to 250 g / 10 min (MFR, 230 ° C., load 21.2 N, according to JIS K7210), and a melt tension of 1.0 to 20 cN, and a melting point of 157 ° C. or less Modified polypropylene component (B) exhibiting a strain hardening property of: at least two polymer blocks P derived from a vinyl aromatic compound and at least one polymer block Q derived from a conjugated diene and / or isobutylene Component (C) of Block Copolymer Having: Softener for Hydrocarbon Rubber

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