Thermoplastic elastomer composition and composite molded body

Abstract

Provided are: a thermoplastic elastomer composition containing the following component (A), component (B1), component (B2), and component (C); a composite molded body using the thermoplastic elastomer composition; a thermoplastic elastomer capable of being molded into a composite molded body excellent in sliding property, fusion property, and fusion durability; and a composite molded body. Component (A): a styrene elastomer; component (B1): a crystalline polypropylene; component (B2): an amorphous polypropylene; and component (C): a silicone-based lubricant.

Description

Technical Field

[0001] This invention relates to a thermoplastic elastomer composition and a composite molded article using the thermoplastic elastomer composition. Background Technology

[0002] Thermoplastic elastomer compositions obtained by melt-blending acrylic resins and styrene-butadiene block copolymers exhibit the characteristics of rubber-like soft materials, while requiring no vulcanization process and possessing the same molding and processability as thermoplastic resins. Therefore, from the perspectives of manufacturing process optimization and reusability, thermoplastic elastomer compositions have attracted attention and are widely used in automotive parts, household appliances, medical device components, wires, and general merchandise. In particular, thermoplastic elastomer compositions are frequently used as sealing materials in automotive and building materials.

[0003] Because automotive sealing materials have complex structures, composite molded parts formed from thermoplastic elastomer compositions are often bonded together to create the desired composite molded parts.

[0004] The inventors previously proposed a bonding technique that fuses a bonding member formed from a thermoplastic elastomer composition to a molded body that is the bonded member without the use of adhesives, etc., and obtained a thermoplastic elastomer composition by dynamically crosslinking a mixture of a styrene-butadiene non-hydrogenated block copolymer, a styrene-butadiene hydrogenated block copolymer, a hydrocarbon rubber softener, and a propylene resin in a certain ratio (Patent Document 1).

[0005] As a technique for welding molded bodies together, a method has been proposed to heat-weld molded bodies obtained by extruding a thermoplastic elastomer composition containing a specific hydrogenated block copolymer, a specific amorphous polyolefin polymer, a polypropylene resin, and a mineral oil-based rubber softener in a specified ratio. In Patent Document 2, an amorphous polyolefin polymer is incorporated into the thermoplastic elastomer composition to improve heat weldability.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-131722

[0007] Patent Document 2: Japanese Patent Application Publication No. 10-120865

[0008] For composite molded bodies used as sealing materials for window frames in automobiles, further sliding performance is required to prevent abnormal noise and permanent strain caused by repeated window raising and lowering. It is known that if a material with high sliding performance is incorporated to improve sliding performance, the weldability and weld durability of the joint components will deteriorate. A technology that balances sliding performance, weldability, and weld durability at a high level is desired.

[0009] The bonding member made of a thermoplastic elastomer composition described in Patent Document 1 maintains good slidability and weldability with the bonded member. However, when it is bent with the interface between the bonding member and the bonded member in the welded portion as the starting point, there is a problem that it simply peels off from the interface. There is room for improvement in the weld durability of the welded portion between the bonding member and the bonded member.

[0010] The thermoplastic elastomer composition described in Patent Document 2 is not satisfactory for applications where it is required to balance slippage, weldability, and weld durability as a joining component. Summary of the Invention

[0011] The purpose of this invention is to solve the problems of the prior art and provide a thermoplastic elastomer composition that can be molded into a composite molded body with excellent sliding properties, weldability and weld durability, as well as a composite molded body formed from the thermoplastic elastomer composition.

[0012] The inventors have discovered that a thermoplastic elastomer composition incorporating a styrene-based elastomer, a specific propylene-based resin, and an organosilicon-based lubricant can achieve a composite molded body with excellent sliding properties, weldability, and weld durability, thus completing this invention.

[0013] Furthermore, it was found that in thermoplastic elastomer compositions with styrene-based elastomers and specific acrylic resins as island structures, using such thermoplastic elastomer compositions and specific thermoplastic elastomer compositions containing acrylic resins as the sea phase, and having a tear elongation of more than a specified value as determined by a specific method, it is also possible to achieve composite molded articles with excellent sliding properties, weldability, and weld durability.

[0014] Further findings revealed that in a composite molded body formed by a joining member and a joined member, the joining member is formed of a first thermoplastic elastomer composition having a sea-island structure in an propylene-based resin sea phase consisting of crystalline polypropylene and non-crystalline polypropylene, wherein a styrene-based elastomer is present as an island phase, and the joined member is formed of a second thermoplastic elastomer composition containing a thermoplastic elastomer of an propylene-based resin. If the tear elongation measured by a specific method using the first thermoplastic elastomer composition and the second thermoplastic elastomer composition is above a specified value, a composite molded body with excellent sliding properties, weldability, and weld durability can be produced.

[0015] That is, the essence of the present invention is as follows.

[0016] [1] A thermoplastic elastomer composition comprising the following components (A), (B1), (B2), and (C), wherein,

[0017] Component (A): Styrene-based elastomer;

[0018] Composition (B1): Crystalline polypropylene;

[0019] Composition (B2): Non-crystalline polypropylene;

[0020] Ingredient (C): Organosilicon lubricant.

[0021] [2] The thermoplastic elastomer composition according to [1], wherein the tear elongation determined by the following method is 230% or more.

[0022] <Method for determining tear elongation>

[0023] The tear elongation between the mark spacing of 20 mm was measured on the JIS K6252 uncut right-angled dumbbell-shaped test piece cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding the thermoplastic elastomer composition [1] at 260°C in an injection molding die filled with a thermoplastic elastomer composition containing acrylic resin as the marine phase (Shore A hardness: 75-85, melting point: 133-143°C) as an insert material.

[0024] [3] The thermoplastic elastomer composition according to [1] or [2], wherein when the total of the components (B1) and (B2) is 100% by mass, the content of the component (B2) is 10% by mass or more and 30% by mass or less.

[0025] [4] The thermoplastic elastomer composition according to any one of [1] to [3], wherein the mass ratio of component (A) is 1.00 or more and 1.30 or less relative to the total mass of component (B1) and component (B2).

[0026] [5] The thermoplastic elastomer composition according to any one of [1] to [4] has a compression set of less than 55% as determined by reference to JIS K6262 under conditions of 70°C, 22 hours, and 25% compression.

[0027] [6] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the melt flow rate (MFR) of the component (B2) is 1 to 10 g / 10 min at a test temperature of 230 °C and a test load of 21.2 N.

[0028] [7] The thermoplastic elastomer composition according to any one of [1] to [6] has an elongation at break of 950% or more as determined by reference to JIS K6251.

[0029] [8] A joining member formed of any one of the thermoplastic elastomer compositions described in [1] to [7].

[0030] [9] An automotive corner member comprising the joining member described in [8].

[0031]

[10] A composite molded body comprising a joining member and a joined member, wherein the joining member is formed of a first thermoplastic elastomer composition and the joined member is formed of a second thermoplastic elastomer composition, wherein the first thermoplastic elastomer composition is any one of [1] to [7].

[0032]

[11] A glass guide channel for automobiles, comprising the composite molded body described in

[10] .

[0033]

[12] A thermoplastic elastomer composition having an island structure in which a styrene elastomer of component (A) exists as an island phase in a marine phase of a propylene resin of component (B), and a tear elongation of 230% or more as determined by the following method.

[0034] <Method for determining tear elongation>

[0035] The tear elongation at a mark spacing of 20 mm was measured for JIS K6252 uncut right-angled dumbbell-shaped test pieces cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding at 260°C in an injection molding die containing an injection-molded sheet material filled with a thermoplastic elastomer composition containing acrylic resin as the marine phase (Shore A hardness: 75-85, melting point: 133-143°C).

[0036]

[13] The thermoplastic elastomer composition according to

[12] , wherein the component (B) is composed of component (B1) crystalline polypropylene and component (B2) non-crystalline polypropylene.

[0037]

[14] The thermoplastic elastomer composition according to

[13] , wherein when the total of the components (B1) and (B2) is 100% by mass, the content of the component (B2) is 10% by mass or more and 30% by mass or less.

[0038]

[15] The thermoplastic elastomer composition according to

[13] or

[14] , wherein the mass ratio of component (A) is 1.00 or more and 1.30 or less relative to the total mass of component (B1) and component (B2).

[0039]

[16] The thermoplastic elastomer composition according to any one of

[12] to

[15] has a compression set of less than 55% as determined by reference to JIS K6262 under conditions of 70°C, 22 hours, and 25% compression.

[0040]

[17] A composite molded body comprising a joining member and a joined member, wherein the joining member is formed of a first thermoplastic elastomer composition and the joined member is formed of a second thermoplastic elastomer composition, wherein,

[0041] The first thermoplastic elastomer composition is a thermoplastic elastomer composition with an island structure in which component (A) styrene elastomer exists as an island phase within the marine phase of component (B) propylene resin.

[0042] The second thermoplastic elastomer composition contains a thermoplastic elastomer containing a propylene resin.

[0043] Using the first thermoplastic elastomer composition and the second thermoplastic elastomer composition, and measuring the tear elongation by the following method, the tear elongation is 230% or more.

[0044] <Method for determining tear elongation>

[0045] The tear elongation at a mark spacing of 20 mm was measured on a JIS K6252 uncut right-angled dumbbell-shaped test piece cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding the first thermoplastic elastomer composition at 260°C in an injection molding die containing the second thermoplastic elastomer composition as an insert material.

[0046]

[18] According to the composite molded body of

[17] , wherein the component (B) is composed of component (B1) crystalline polypropylene and component (B2) non-crystalline polypropylene.

[0047]

[19] According to the composite molded article of

[18] , wherein when the total of the components (B1) and the components (B2) is 100% by mass, the content of the components (B2) is 10% by mass or more and 30% by mass or less.

[0048]

[20] A glass guide channel for automobiles, comprising any one of the composite molded bodies described in

[17] to

[19] .

[0049] Invention Effects

[0050] According to the present invention, a thermoplastic elastomer composition capable of being molded into a composite molded body with excellent sliding properties, weldability and weld durability can be provided, as well as a composite molded body using the thermoplastic elastomer composition.

[0051] The thermoplastic elastomer composition and composite molded body of the present invention are useful as sealing materials for automobiles and building materials due to their excellent sliding properties, weldability, and weld durability. They are particularly useful as composite molded bodies for automotive glass guide channels and the like. Attached Figure Description

[0052] Figure 1 This is a perspective view showing an example of an automotive glass guide channel in which the present invention is applied.

[0053] Figure 2 This is a front view of the JIS K6252 uncut right-angled dumbbell-shaped test piece used for tear elongation determination.

[0054] Explanation of reference numerals in the attached figures

[0055] 1A, 1B: Joined components; 2: Joining components; 3: Composite molded body; 10: JIS K6252 uncut right-angled dumbbell-shaped test piece. Detailed Implementation

[0056] The present invention will now be described in detail. The present invention is not limited to the following description and can be implemented in any way without departing from the spirit of the invention.

[0057] In this specification, when “~” is used to indicate numerical or physical property values ​​inserted before or after it, it is used as including the values ​​before and after it.

[0058] [Thermoplastic elastomer composition]

[0059] The thermoplastic elastomer composition of the present invention contains the following components (A), (B1), (B2) and (C).

[0060] Component (A): Styrene-based elastomer (hereinafter, sometimes referred to as "styrene-based elastomer (A)")

[0061] Composition (B1): Crystalline polypropylene (hereinafter, sometimes referred to as "crystalline polypropylene (B1)")

[0062] Composition (B2): Non-crystalline polypropylene (hereinafter, sometimes referred to as "non-crystalline polypropylene (B2)")

[0063] Ingredient (C): Silicone-based lubricant (hereinafter, sometimes referred to as "silicone-based lubricant (C)")

[0064] The thermoplastic elastomer composition of the present invention is also a thermoplastic elastomer composition with a sea-island structure in which component (A) styrene elastomer is present as an island phase in the marine phase of component (B) propylene resin (hereinafter, sometimes referred to as "propylene resin (B)"), and the tear elongation is 230% or more as determined by the following method.

[0065] The formation of island structures as described above by thermoplastic elastomer compositions can be confirmed by the methods shown below.

[0066] First, as a pretreatment, the material to be observed is embedded in epoxy resin, and sections are prepared using diamond tools. The prepared sections are then stained with osmium tetroxide or ruthenium tetroxide in a desiccator. Next, the stained sections are observed using a transmission electron microscope. The marine and island portions of island structures are distinguished by the intensity of osmium tetroxide staining on the resin; this is used to confirm the presence or absence of island structures. Styrene-based elastomers are stained more darkly (darkly), while acrylic resins are stained less brightly (lightly).

[0067] [Method for determining tear elongation]

[0068] Regarding the method for determining the tear elongation in this invention (hereinafter, sometimes referred to as "the method for determining the tear elongation in this invention"), please refer to... Figure 2 Please provide an explanation.

[0069] In the following text, the thermoplastic elastomer composition of the present invention supplied for the tear elongation determination is sometimes referred to as the "test thermoplastic elastomer composition", and the thermoplastic elastomer composition containing an propylene resin as a marine phase, which is used as a compound material for the tear elongation determination, is referred to as the "thermoplastic elastomer composition for insert materials".

[0070] The tear elongation of the present invention is specifically determined according to the following operating steps (1) to (4).

[0071] (1) A thermoplastic elastomer composition for use as an insert material is made by using a thermoplastic elastomer composition containing a propylene resin as the marine phase (Shore A hardness: 75-85, melting point: 133-143℃), which is molded into an injection-molded sheet with a thickness of 2mm, and the injection-molded sheet is cut into 10cm×5cm pieces to make an insert material.

[0072] (2) The insert material is inserted into the mold of a 110-ton injection molding machine. The test thermoplastic elastomer composition is injected into the mold at a setting of 260°C barrel temperature and 40°C mold temperature. By insert molding method, a composite molded body is obtained in which the thickness portion of the molded sheet formed by the insert material and the test thermoplastic elastomer composition is integrally formed at the edge of the sheet.

[0073] (3) Punch out the following from the composite molded body Figure 2 The JIS K6252 uncut right-angled dumbbell-shaped test piece 10 is shown. This test piece 10 is used in thermoplastic elastomer compositions containing acrylic resin as an insert material (…). Figure 2 The portion with dots) 10A and the tested thermoplastic elastomer composition portion ( Figure 2 The composite test piece with a fracture initiation point 10X and a welded interface 10C of 10B (the blank part in the middle) is left blank.

[0074] The test piece 10 Figure 2 As shown, the insert material thermoplastic elastomer composition part 10A is used as the upper part in the vertical direction, the test thermoplastic elastomer composition part 10B is used as the lower part in the vertical direction, and the weld interface 10C is used as the center line. Marking lines 10a and 10b are drawn at a distance of 10mm in the vertical direction, with a total distance of 20mm between the marking lines.

[0075] (4) For the test piece 10, at a test temperature of 23°C and a test speed of 200 mm / min, the thermoplastic elastomer composition portions 10A and 10B are stretched from the weld interface 10C in the opposite direction, and the tear elongation is measured. The tear strength can also be measured during the tear elongation measurement.

[0076] That is, when evaluating weld durability, the inventors found that the reproduction of weld durability was insufficient when using test pieces made of JIS No. 3 dumbbell shape, which are commonly used in tensile tests. Therefore, the inventors repeatedly conducted research to evaluate weld durability with good reproducibility, and confirmed that the JIS K6252 uncut right-angled dumbbell shape, previously used in tear tests of single materials, creates a location at the weld interface prone to breakage, as described above. Figure 2 In the test piece 10 of the V-groove portion 10X of the weld interface 10C, the tear elongation is measured by using the test piece 10, which can evaluate the weld durability of the thermoplastic elastomer composition as a bonding member with good reproducibility.

[0077] Here, the thermoplastic elastomer composition containing acrylic resin as the marine phase (Shore A hardness: 75-85, melting point: 133-143°C) used as the thermoplastic elastomer composition for insert material is not particularly limited, but "TREXPRENE (registered trademark) 3855N (dynamically cross-linked thermoplastic elastomer, Shore A hardness: 83, melting point: 138°C)" manufactured by Mitsubishi Chemical Corporation can be used as a commercially available product.

[0078] Typically, increasing the amount of styrene-based elastomer (A), a rubber component, is considered as a means to improve tear elongation. However, this reduces the proportion of acrylic resin (B), which acts as a welding component, thereby decreasing weldability. The inventors have discovered that by incorporating amorphous polypropylene (B2) together with crystalline polypropylene (B1), tear elongation can be improved without compromising weldability, thus maintaining weld durability.

[0079] [mechanism]

[0080] The exact reasons why the thermoplastic elastomer composition of the present invention achieves the above-mentioned effects are uncertain, but can be presumed as follows.

[0081] The non-crystalline polypropylene (B2) contained in the propylene resin (B) improves the dispersibility of the styrene elastomer (A) as a rubber component, resulting in higher tear elongation characteristics than existing products. This makes it less likely to apply force to the welded part (weld interface) between the joining component and the joined component, improving sliding properties and obtaining good weld durability.

[0082] [Styrene-based elastomers (A)]

[0083] The styrene-based elastomer (A) used in the thermoplastic elastomer composition of the present invention can be a known elastomer.

[0084] As a styrene-based elastomer (A), preferably examples include: a block copolymer having at least two polymer blocks mainly composed of vinyl aromatic compounds and at least one polymer block containing butadiene, and / or a hydrogenated product of the block copolymer. Hereinafter, the block copolymer of component (A) and / or its hydrogenated product are sometimes referred to as "(hydrogenated) block copolymer".

[0085] Here, "polymer blocks mainly composed of vinyl aromatic compounds" refers to blocks formed by polymerizing monomers mainly composed of vinyl aromatic compounds. "Polymer blocks containing butadiene" refers to blocks formed by polymerizing monomers containing butadiene. "Mainly composed of vinyl aromatic compounds" means containing more than 50 mol% vinyl aromatic compounds.

[0086] The composition of component (A) is a polymer block primarily composed of vinyl aromatic compounds. The vinyl aromatic compounds of the monomers are not limited, but styrene and / or styrene derivatives such as α-methylstyrene are preferred. Styrene is preferred as the main component. The polymer block primarily composed of vinyl aromatic compounds may also contain monomers other than vinyl aromatic compounds as raw materials.

[0087] The butadiene-containing polymer block of component (A) may also contain monomers other than butadiene, such as isoprene as a raw material.

[0088] The mass percentage of “polymer blocks mainly composed of vinyl aromatic compounds” in the block copolymer of component (A) is not limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, preferably 55% by mass or less, more preferably 50% by mass or less, and even more preferably 45% by mass or less.

[0089] The chemical structure of the block copolymer of component (A) can be any one of linear, branched, or radial. Component (A) is preferably a block copolymer represented by formula (I) or (II) below, and from the viewpoint of improving mechanical strength, the structure of formula (I) below is more preferred.

[0090] P-(QP) m (I)

[0091] (PQ) n (II)

[0092] (In the formula, P represents a polymer block mainly composed of vinyl aromatic compounds, Q represents a polymer block containing butadiene, m represents an integer from 1 to 5, and n represents an integer from 2 to 5.)

[0093] When multiple blocks P and multiple blocks Q are present, these compound units can be identical or different from each other.

[0094] In equation (I) or (II), m and n are better when considering the order-disorder transition temperature of the polymer as rubber, but better when considering ease of manufacturing and cost.

[0095] From the viewpoint of the rubber elasticity of the composition, component (A) is preferably a block copolymer represented by formula (I), more preferably a block copolymer represented by formula (I) with m of 3 or less, even more preferably a block copolymer represented by formula (I) with m of 2 or less, and most preferably a block copolymer represented by formula (I) with m of 1.

[0096] Component (A) can be a hydrogenated product of a block copolymer having blocks P and Q. In this case, a hydrogenated product of a block copolymer represented by formula (I) is preferred, a hydrogenated product of a block copolymer represented by formula (I) with m of 3 or less is more preferred, a hydrogenated product of a block copolymer represented by formula (I) with m of 2 or less is even more preferred, and a hydrogenated product of a block copolymer represented by formula (I) with m of 1 is most preferred.

[0097] Examples of (hydrogenated) block copolymers comprising (A) having at least two polymer blocks primarily composed of vinyl aromatic compounds and at least one polymer block containing butadiene include: styrene-butadiene-styrene block copolymers and their hydrogenated products, styrene-isoprene-butadiene-styrene block copolymers and their hydrogenated products, etc.

[0098] Among these, when used as a bonding component, it is easy to obtain the flowability required for the weldability of olefin-based rubbers and olefin-based thermoplastic elastomers used as bonded components, therefore styrene-butadiene-styrene hydrogenated block copolymers are preferred.

[0099] The weight-average molecular weight of the styrene-based elastomer (A) of component (A) is a polystyrene equivalent value determined by gel permeation chromatography (hereinafter, sometimes simply referred to as GPC), preferably 200,000 or more, more preferably 220,000 or more, and even more preferably 240,000 or more. The upper limit of the weight-average molecular weight of the styrene-based elastomer (A) is preferably 600,000 or less, more preferably 580,000 or less, even more preferably 560,000 or less, and from the viewpoint of weld strength, particularly preferably 430,000 or less.

[0100] If the weight-average molecular weight of the styrene-based elastomer (A) is within the above range, it can achieve good sliding properties while having sufficient compression set.

[0101] The method for manufacturing styrene-based elastomers (A) can be any method, as long as the aforementioned structure and physical properties can be obtained, and there are no particular limitations. For example, block polymerization using a lithium catalyst or the like can be carried out by the method described in Japanese Patent Application Publication No. 7-97493, thereby obtaining a block copolymer. The hydrogenation (hydrogenation) of the block copolymer can be carried out, for example, by the method described in Japanese Patent Application Publication No. 59-133203, in the presence of a hydrogenation catalyst in an inert solvent.

[0102] Commercially available products of styrene-based elastomers (A) include: "TAIPOL (registered trademark)-6151" and "TAIPOL (registered trademark)-6159" manufactured by Taiwan Synthetic Rubber (TSRC) Co., Ltd.; "G1651" and "G1633" manufactured by Kronen Polymer Japan Co., Ltd.; and "SEPTON (registered trademark) 4099" manufactured by Kuraray Co., Ltd.

[0103] Styrene-based elastomers (A) can be used in combination with one or more elastomers with different compositions and physical properties.

[0104] [Acrylic Resin (B)]

[0105] The acrylic resin (B) used in the thermoplastic elastomer composition of the present invention is preferably composed of crystalline polypropylene (B1) and non-crystalline polypropylene (B2). Crystalline polypropylene (B1) is the component that primarily contributes to injection molding properties. Non-crystalline polypropylene (B2) is the component that primarily imparts weldability and weld durability to the thermoplastic elastomer composition.

[0106] In this invention, "propylene resin" refers to a resin with a content of propylene unit of 50% or more by mass, and also includes compositions composed of a single resin component and compositions composed of multiple resin components.

[0107] In crystalline polypropylene (B1), the content of ethylene units is less than 7% by mass relative to the total number of monomer units constituting crystalline polypropylene (B1). The upper limit of the ethylene unit content is preferably 6% by mass or less, more preferably 5% by mass or less. The lower limit of the ethylene unit content in crystalline polypropylene (B1) is preferably 1% by mass or more, more preferably 2% by mass or more. Furthermore, the content of propylene units in crystalline polypropylene (B1) is typically 50% by mass or more, preferably 60 to 99% by mass, more preferably 80 to 98% by mass, relative to the total number of monomer units constituting crystalline polypropylene (B1).

[0108] The content of each structural unit in crystalline polypropylene (B1) can be determined by infrared spectroscopy. The same applies to amorphous polypropylene (B2), which will be discussed later.

[0109] The melting peak temperature of crystalline polypropylene (B1) is preferably above 100°C and below 157°C. When the melting peak temperature is above the lower limit mentioned above, it is preferred from the viewpoint of heat resistance, and when it is below the upper limit mentioned above, it is preferred from the viewpoint of compatibility with styrene-based elastomers (A).

[0110] The melting peak temperatures of crystalline polypropylene (B1) and non-crystalline polypropylene (B2), described later, can be determined according to JIS K7121 by the following method.

[0111] Using a differential scanning calorimeter (DSC6220 manufactured by Seiko Nanotechnology Co., Ltd.), the following steps (1) to (3) are performed sequentially.

[0112] In each process, time is plotted on the horizontal axis and melting heat is plotted on the vertical axis to obtain the melting curve, and the peak of the peak observed in process (3) is taken as the melting peak temperature.

[0113] Procedure (1): Heat 5 mg of sample from room temperature to 200°C at a rate of 100°C / min from 40°C. After the heating is completed, keep it for 3 minutes.

[0114] Step (2): Cool down from 200℃ to 40℃ at a rate of 10℃ / min. After cooling, maintain the temperature for 3 minutes.

[0115] Process (3): Increase the temperature from 40°C to 200°C at a rate of 10°C / min.

[0116] As crystalline polypropylene (B1), a propylene-ethylene copolymer is preferred. A propylene-ethylene copolymer is a copolymer having propylene units, ethylene units, and structural units other than propylene and ethylene units as needed. Specifically, structural units other than propylene and ethylene units can be categorized as α-olefin units other than propylene. Other α-olefin units include, for example, 1-butene units, 1-pentene units, 1-hexene units, 1-heptene units, 1-octene units, 1-nonene units, 1-decene units, 1-undecene units, 1-dodecene units, 1-tetracene units, 1-tetradecene units, 1-pentadecaene units, 1-hexadecene units, 1-heptadecene units, 1-octadecene units, 1-nonadecaene units, 1-eicosene units, 3-methyl-1-butene units, 3-methyl-1-pentene units, 4-methyl-1-pentene units, 2-ethyl-1-hexene units, and 2,2,4-trimethyl-1-pentene units. Crystalline polypropylene (B1) may contain only one of these other structural units, or it may contain two or more of them.

[0117] The melt flow rate (MFR) of crystalline polypropylene (B1), as measured according to JIS K7210 at a test temperature of 230°C and a test load of 21.2 N, is preferably 0.5 to 50 g / 10 min. By keeping the MFR of crystalline polypropylene (B1) within the above range, its moldability tends to become excellent.

[0118] In the amorphous polypropylene (B2), the content of ethylene units is 7% by mass or more and 50% by mass or less relative to the total number of monomer units constituting the amorphous polypropylene (B2). The upper limit of the content of ethylene units is preferably 20% by mass or less, more preferably 15% by mass or less. The lower limit of the content of ethylene units is preferably 8% by mass or more, more preferably 10% by mass or more.

[0119] The content of propylene units in amorphous polypropylene (B2) is typically 50% by mass or more and 93% by mass or less, relative to the total number of monomer units constituting amorphous polypropylene (B2). The upper limit of the content of propylene units in amorphous polypropylene (B2) is preferably 92% by mass or less, more preferably 90% by mass or less. The lower limit of the content of propylene units in amorphous polypropylene (B2) is preferably 80% by mass or more, more preferably 85% by mass or more. When the content of propylene units in amorphous polypropylene (B2) is within the above-mentioned range, it easily falls within the range of the melting peak temperature described later, and is therefore preferred.

[0120] The melting peak temperature of amorphous polypropylene (B2) is preferably 45°C or higher and 100°C or lower. By setting the melting peak temperature of amorphous polypropylene (B2) to the upper limit mentioned above, it is easier to impart weldability to the components being bonded. From this viewpoint, the melting peak temperature of amorphous polypropylene (B2) is more preferably 90°C or lower. From the viewpoint of heat resistance, the lower limit of the melting peak temperature of amorphous polypropylene (B2) is preferably 45°C or higher, and more preferably 55°C or higher.

[0121] The non-crystalline polypropylene (B2) non-crystalline propylene-ethylene copolymer can also have structural units other than ethylene units and propylene units, such as α-olefin units other than propylene. Examples of other α-olefin units include: 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetracene, 1-tetradecene, 1-pentadecaene, 1-hexadecene, 1-heptadecene, 1-heptadecene, 1-octadecene, 1-nonadecaene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene, and 2,2,4-trimethyl-1-pentene. The non-crystalline polypropylene (B2) can contain only one of these other structural units or more than two.

[0122] The melt flow rate (MFR) of the amorphous polypropylene (B2), as measured according to JIS K7210 at a test temperature of 230°C and a test load of 21.2 N, is preferably 1 to 10 g / 10 min. By keeping the MFR of the amorphous polypropylene (B2) within the above range, it is easier to impart strong shear during melt mixing of the thermoplastic elastomer composition, and the material dispersibility tends to become excellent.

[0123] When the total of crystalline polypropylene (B1) and non-crystalline polypropylene (B2) is set at 100% by mass, from the viewpoint of maintaining weldability and weld durability while ensuring heat resistance, it is preferable that the content of crystalline polypropylene (B1) is 70% by mass or more and 90% by mass or less, and the content of non-crystalline polypropylene (B2) is 10% by mass or more and 30% by mass or less. From these viewpoints, the content of crystalline polypropylene (B1) in the total of 100% by mass of crystalline polypropylene (B1) and non-crystalline polypropylene (B2) is 75% by mass or more and 85% by mass or less, and the content of non-crystalline polypropylene (B2) is more preferably 15% by mass or more and 25% by mass or less.

[0124] As a method for manufacturing crystalline polypropylene (B1) and non-crystalline polypropylene (B2), known polymerization methods utilizing known catalysts for olefin polymerization can be used. For example, polymerization methods utilizing Ziegler-Natta catalysts can be used. Slurry polymerization, solution polymerization, bulk polymerization, gas-phase polymerization, etc., can be used in this polymerization method, and two or more of these methods can be combined.

[0125] Crystalline polypropylene (B1) and non-crystalline polypropylene (B2) are also available as commercial products.

[0126] Commercially available products conforming to crystalline polypropylene (B1) include: PrimPolypro (registered trademark) manufactured by Prim Polymers Co., Ltd.; Sumitomo NOBLEN (registered trademark) manufactured by Sumitomo Chemical Co., Ltd.; Polypropylene Block Copolymer manufactured by SunAllomer Co., Ltd.; NOVATEC (registered trademark) PP manufactured by Nippon Polypropylene Co., Ltd.; Moplen (registered trademark) manufactured by LyondellBasell Co., Ltd.; ExxonMobil PP manufactured by ExxonMobil Co., Ltd.; Formolene (registered trademark) manufactured by Formosa Plastics Co., Ltd.; Borealis PP manufactured by Borealis Co., Ltd.; SEETEC PP manufactured by LG Chem Co., Ltd.; ASIPOLYPROPYLENE manufactured by A. Schulman Co., Ltd.; INEOS PP manufactured by INEOS Olefins & Polymers Co., Ltd.; Braskem PP manufactured by Braskem Co., Ltd.; and Samsung Total Co., Ltd. Brands such as "Total," "Sabic (registered trademark) PP" manufactured by Sabic, "TOTAL PETROCHEMICALS Polypropylene" manufactured by Total Petrochemicals, and "YUPLENE (registered trademark)" manufactured by SK are available for selection.

[0127] Commercially available products conforming to non-crystalline polypropylene (B2), as propylene-ethylene copolymers, include, for example, "PRIME TPO (registered trademark)" manufactured by Pramie Polymers Co., Ltd., "VERSIFY (registered trademark)" manufactured by Dow Chemical Company, and "Vistamaxx (registered trademark)" manufactured by ExxonMobil Chemical Company. As a propylene-ethylene-1-butene copolymer, for example, "TAFMER (registered trademark) XM" manufactured by Mitsui Chemicals Co., Ltd. Appropriate selections can be made from these.

[0128] Acrylic resins (B) can also contain crystalline polypropylene (B1) and non-crystalline polypropylene (B2), which can be used in combination to produce products with different compositions and physical properties.

[0129] In the thermoplastic elastomer composition of the present invention, 40 parts by mass and 120 parts by mass of acrylic resin (B) are preferably contained relative to 100 parts by mass of styrene elastomer (A) (when components (B1) and (B2) are used as acrylic resin (B), the total of components (B1) and (B2) is included).

[0130] From the viewpoint of moldability, the lower limit of the content of acrylic resin (B) in the thermoplastic elastomer composition of the present invention is preferably 40 parts by weight or more, more preferably 50 parts by weight or more, and even more preferably 60 parts by weight or more, relative to 100 parts by weight of styrene elastomer (A). From the viewpoint of obtaining sufficient softness as a molded article, the upper limit of the content of acrylic resin (B) in the thermoplastic elastomer composition of the present invention is preferably 120 parts by weight or less, more preferably 110 parts by weight or less, and even more preferably 100 parts by weight or less, relative to 100 parts by weight of styrene elastomer (A).

[0131] In the thermoplastic elastomer composition of the present invention, the mass ratio of styrene-based elastomer (A) to acrylic resin (B) (when components (B1) and (B2) are used as acrylic resin (B), the total mass of components (B1) and (B2)) is preferably 1.00 or more and 1.30 or less, more preferably 1.10 or more and 1.27 or less. By keeping the styrene-based elastomer (A) and acrylic resin (B) within the above-mentioned mass ratio range, a good island structure is formed in which the styrene-based elastomer (A) exists as an island phase in the marine phase of acrylic resin (B), which easily tends to highly balance weldability and compression set.

[0132] [Organosilicon-based lubricant (C)]

[0133] Examples of silicone-based lubricants (C) include silicone oil, silicone masterbatch, and liquid siloxane wax. The silicone-based lubricant (C) is preferably used in the range of 0.5 to 50 parts by weight, more preferably 1 to 25 parts by weight, further preferably 1.4 to 13.9 parts by weight, and particularly preferably 2.8 to 8.3 parts by weight, relative to 100 parts by weight of the styrene-based elastomer component (A). When the content of the silicone-based lubricant (C) is within the above range, excellent sliding properties can be obtained by suppressing the reduction of weldability.

[0134] The kinematic viscosity (at 25°C) of the silicone-based lubricant (C) is preferably 1 cSt or higher, more preferably 5 cSt or higher, and even more preferably 10 cSt or higher, with no particular upper limit. Within the above range, the higher the kinematic viscosity, the faster the improvement in sliding performance, and the better the slow-release effect of the improvement in sliding performance.

[0135] Here, the kinematic viscosity is the kinematic viscosity at 25°C measured using an Ubbelohde viscometer according to ASTM D445-46T (or JIS Z8803).

[0136] As a silicone-based lubricant (C), commercially available products can also be used. Specifically, examples include "KF96-10CS", "KF96-100CS", "KF96-1000CS" and "KF96-5000CS" manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0137] Silicone-based lubricants (C) can be used alone or in any combination and ratio of two or more.

[0138] [Softener for Hydrocarbon-Based Rubber (D)]

[0139] From the viewpoint of improving formability, the thermoplastic elastomer composition of the present invention preferably contains a hydrocarbon rubber softener (D) (hereinafter sometimes referred to as "component (D)").

[0140] From the viewpoint of formability, the lower limit of the content of hydrocarbon rubber softener (D) in the thermoplastic elastomer composition of the present invention is generally 70 parts by mass or more, preferably 75 parts by mass or more, and more preferably 80 parts by mass or more, relative to 100 parts by mass of styrene-based elastomer (A). From the viewpoint of flexibility, the upper limit of the content of hydrocarbon rubber softener (D) in the thermoplastic elastomer composition of the present invention is generally 130 parts by mass or less, preferably 125 parts by mass or less, and more preferably 120 parts by mass or less, relative to 100 parts by mass of styrene-based elastomer (A).

[0141] Examples of softeners (D) for hydrocarbon-based rubber include mineral oil-based softeners and synthetic resin-based softeners. From the viewpoint of affinity with other components, mineral oil-based softeners are preferred. Mineral oil-based softeners are typically mixtures of aromatic hydrocarbons, cycloalkanes, and paraffinic hydrocarbons. Specifically, those containing more than 50% paraffinic hydrocarbons are called paraffinic oils, those containing 30-45% cycloalkanes are called cycloalkanes, and those containing more than 35% aromatic hydrocarbons are called aromatic oils. Among these, paraffinic oils are preferred.

[0142] The kinematic viscosity of the softener (D) for hydrocarbon-based rubber at 40°C is not particularly limited, but it is preferably 20 cSt or higher, more preferably 50 cSt or higher, more preferably 800 cSt or lower, and more preferably 600 cSt or lower. The flash point (COC method) of the softener for hydrocarbon-based rubber is preferably 200°C or higher, and more preferably 250°C or higher.

[0143] Hydrocarbon-based rubber softeners (D) are available as commercially available products. Examples of suitable commercially available products include: the "Nisseki Polybutene (registered trademark) HV" series manufactured by JX Nippon Minerals & Energy Co., Ltd., and the "DIANA (registered trademark) PROCESS OIL PW" series manufactured by Idemitsu Kosan Co., Ltd. A suitable product can be appropriately selected from these.

[0144] Hydrocarbon-based rubber softeners (D) can be used alone or in any combination and ratio of two or more.

[0145] [Other ingredients]

[0146] In the manufacture of the thermoplastic elastomer composition of the present invention, other components besides those described in (A) to (D) may be used as raw materials as needed, without impairing the effects of the present invention. Hereinafter, "component (B)" includes component (B1) and component (B2).

[0147] Other components include, for example: crosslinking agents and resins such as thermoplastic resins and elastomers other than components (A) and (B); antioxidants; fillers; heat stabilizers; light stabilizers; UV absorbers; neutralizers; lubricants other than component (C); antifogging agents; antiblocking agents; slip agents; dispersants; colorants; flame retardants; antistatic agents; conductivity imparting agents; metal passivators; molecular weight regulators; antibacterial agents; antifungal materials; antimicrobial agents; antiviral agents; fluorescent whitening agents, and various other additives. These can be used alone or in combination with any of the components.

[0148] Organic peroxides, phenolic resins, and other crosslinking auxiliaries can be used as crosslinking agents. Only one of these crosslinking agents can be used, or two or more can be used in combination.

[0149] As an organic peroxide that can be used as a crosslinking agent, either aromatic organic peroxides or aliphatic organic peroxides can be used. Specifically, examples include: di-tert-butyl peroxide, tert-butyl isopropylbenzene peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)-3-hexyne, 1,3-bis(tert-butylperoxide isopropyl)benzene, 1,1-di(tert-butylperoxide)-3,3,5-trimethylcyclohexane, and other dialkyl peroxides; tert-butyl peroxide, tert-butyl isopropyl carbonate, 2,5-dimethyl-2,5-di(benzoyl peroxide)hexane, 2,5-dimethyl-2,5-di(benzoyl peroxide)-3-hexyne, and other peroxide esters; and acetyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and other hydroperoxides. Of these, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane is preferred. These organic peroxides may be used alone or in combination of two or more.

[0150] Examples of phenolic resins that can be used as crosslinking agents include alkylphenol formaldehyde and bromoalkylphenol formaldehyde. These phenolic resins can be used alone or in combination of two or more.

[0151] Examples of crosslinking aids other than organic peroxides and phenolic resins include: peroxide aids such as sulfur, p-benzoquinone dioxime, p-nitrosobenzene, and 1,3-diphenylguanidine; crosslinking aids for phenolic resins such as anhydrous stannous chloride, stannous chloride dihydrate, and ferric chloride; multifunctional vinyl compounds such as divinylbenzene, triallyl cyanurate, triallyl isocyanurate, and diallyl phthalate; and multifunctional (meth)acrylate compounds such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and allyl (meth)acrylate. These can be used individually or in combination of two or more.

[0152] When using a crosslinking agent, from the viewpoint of ensuring sufficient crosslinking reaction, the amount used is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 1.5 parts by mass or more, relative to 100 parts by mass of the styrene-based elastomer (A). From the viewpoint of controlling the crosslinking reaction, the amount of crosslinking agent used is preferably 10.0 parts by mass or less, more preferably 9.0 parts by mass or less, and even more preferably 8.0 parts by mass or less, relative to 100 parts by mass of the styrene-based elastomer (A).

[0153] Examples of thermoplastic resins other than 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 polyoxymethylene homopolymers and polyoxymethylene copolymers; polymethyl methacrylate resins and polyolefin resins (but excluding resins that conform to component (B)).

[0154] Examples of elastomers other than components (A) and (B) include polyester elastomers and polybutadiene.

[0155] When the thermoplastic elastomer composition of the preferred embodiment of the present invention contains resins other than components (A), (B1), and (B2), in order to fully obtain the effect of containing components (A) to (C), the content of the other resins is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, relative to a total of 100 parts by mass of components (A) to (C).

[0156] Examples of antioxidants (E) (hereinafter sometimes referred to as "component (E)") include phenolic antioxidants, phosphite antioxidants, and thioether antioxidants. When using antioxidants (E), the amount of antioxidant (E) relative to 100 parts by weight of the styrene-based elastomer (A) is typically in the range of 0.01 to 3.0 parts by weight, preferably 0.15 to 0.6 parts by weight. Good thermal stability is obtained when the content of antioxidant (E) is within the above range.

[0157] Examples of filler materials include: glass fiber, hollow glass microspheres, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, metal soap, titanium dioxide, and carbon black. When using filler materials, the filler material is typically used in the range of 0.3 to 100 parts by weight relative to 100 parts by weight of the styrene-based elastomer (A).

[0158] [Method for manufacturing thermoplastic elastomer compositions]

[0159] The thermoplastic elastomer composition of the present invention is preferably obtained by melt-blending a composition containing a specified amount of a styrene-based elastomer (A), an propylene-based resin (B) (or components (B1) and (B2) when used as components (B1) and (B2) of the propylene-based resin (B)), an organosilicon lubricant (C), a hydrocarbon-based rubber softener (D), and other components.

[0160] In this invention, as a mixing and blending apparatus for melt blending, for example, a non-open Banbury mixer, mixing rollers, a kneader, or a twin-screw extruder are used. Among these, a twin-screw extruder is preferred. A preferred method of manufacturing using a twin-screw extruder is to supply the components to the feed inlets (hoppers) of a twin-screw extruder having multiple feed inlets for melt blending.

[0161] The temperature during melt mixing is typically 80–300°C, preferably 100–250°C.

[0162] When manufacturing the thermoplastic elastomer composition of the present invention by melt mixing using a twin-screw extruder, it is preferable to extrude while maintaining the relationship of formula (i) between the barrel radius (R (mm)), screw speed (N (rpm)) and discharge rate (W (kg / h)) of the twin-screw extruder, and more preferably extrude while maintaining the relationship of formula (ii).

[0163] 2.6 <NW / R 3 <22.6 (i)

[0164] 3.0 <NW / R 3 <20.0 (ii)

[0165] To efficiently produce thermoplastic elastomer compositions, it is preferable that the relationship between the barrel radius (R (mm)), screw speed (N (rpm)), and discharge rate (W (kg / h)) of the twin-screw extruder is greater than the lower limit mentioned above. On the other hand, it is preferable that the relationship is less than the upper limit mentioned above, as this suppresses heat generation caused by shearing and reduces the likelihood of foreign matter being generated that could lead to unsatisfactory appearance.

[0166] [Physical Properties of Thermoplastic Elastomer Compositions]

[0167] The thermoplastic elastomer composition of the present invention is preferably a sea-island structure thermoplastic elastomer composition in which a styrene elastomer (A) is present as an island phase in the marine phase of a propylene resin (B), and the tear elongation measured by the tear elongation determination method of the present invention described above is typically 230% or more. By achieving a tear elongation of 230% or more, excellent weldability and weld durability are achieved.

[0168] From the viewpoint of weld durability, the elongation at break of the thermoplastic elastomer composition of the present invention is preferably 250% or more. There is no particular upper limit to this elongation at break, but it is generally 400% or less.

[0169] According to the method for determining tear elongation of the present invention, the tear strength of the thermoplastic elastomer composition of the present invention, when measuring tear elongation, is preferably 40 N / mm or more, more preferably 50 N / mm or more. It is considered that if the tear strength is 30 N / mm or more, it is within the scope of practical use as a sealing material for window frames in automobiles, etc. There is no particular upper limit to this tear strength, but it is generally 60 N / mm or less.

[0170] The thermoplastic elastomer composition of the present invention preferably conforms to JIS K6262, and exhibits a compression set of 55% or less under conditions of 70°C, 22 hours, and 25% compression. By achieving a compression set of 55% or less at 70°C, the thermoplastic elastomer composition of the present invention can achieve sufficient durability against compression, even in applications such as automotive sealing materials and building material sealing materials, where it is repeatedly used in a compressed state through the opening and closing of window frames, door frames, etc.

[0171] The thermoplastic elastomer composition of the present invention has a melt flow rate (MFR) of 0.5 g / 10 min or more, measured according to the method based on JIS K7210 at a measuring temperature of 230°C and a measuring load of 21.2 N. From the viewpoint of moldability, this is preferred, more preferably 0.7 g / 10 min or more, and even more preferably 0.9 g / 10 min or more. From the viewpoint of moldability, the melt flow rate (MFR) of the thermoplastic elastomer composition of the present invention is preferably 80 g / 10 min or less, more preferably 75 g / 10 min or less, and even more preferably 70 g / 10 min or less.

[0172] From a lightweighting perspective, the thermoplastic elastomer composition of the present invention preferably has a density of 0.95 g / cm³, as determined by method A (water displacement method) based on ISO 1183. 3 Hereinafter, the density is more preferably 0.93 g / cm³. 3 The following is a further preferred value: 0.91 g / cm³ 3 The lower limit of density is typically 0.90 g / cm³. 3 above.

[0173] From the viewpoint of achieving suitable fit with the substrate when used as a joining component, the lower limit of the tensile stress at fracture of the thermoplastic elastomer composition of the present invention, measured according to the procedure based on JIS K6251, is preferably 19.0 MPa or more, more preferably 20.0 MPa or more. From the viewpoint of preventing the temporarily fitted joining component from detaching from the substrate, the upper limit of the tensile stress at fracture is preferably 29.0 MPa or less, more preferably 28.0 MPa or less.

[0174] From the same viewpoint, the elongation at break of the thermoplastic elastomer composition of the present invention, measured according to the procedure based on JIS K6251, is preferably 950% or more, more preferably 1000% or more. From the viewpoint that the joined parts do not detach from the substrate once engaged, the upper limit of the elongation at break is preferably 1300% or less, more preferably 1200% or less.

[0175] [Molded body / Application]

[0176] The thermoplastic elastomer composition of the present invention can generally be molded into a molded body using various molding methods used in thermoplastic elastomer compositions, such as injection molding, extrusion molding, blow molding, and compression molding. Among these methods, injection molding is preferred for the molding of the thermoplastic elastomer composition of the present invention. Molded bodies that have undergone secondary processing such as lamination or thermoforming can also be produced after these molding processes.

[0177] Molded bodies formed from the thermoplastic elastomer composition of the present invention can be used in a wide range of fields, including: automotive parts such as skins, windshields, headliners, interior trim sheets, bumper guards, body guards, air spoilers, air duct hoses, and sealing materials; civil engineering parts such as waterproofing materials, sealant materials, window frames, and sealing materials; sporting goods such as golf club grips and tennis racket grips; industrial parts such as hoses and gaskets; household appliance parts such as hoses and gaskets; medical parts such as medical containers, gaskets, and gaskets; food parts such as containers and gaskets; medical machine parts; wires; and general merchandise.

[0178] The molded articles formed from the thermoplastic elastomer compositions of the present invention are suitable for use as automotive sealing materials, building material sealing materials, and automotive sealing materials, particularly automotive glass guide channels, among those listed above.

[0179] [Jointed Components / Composite Molded Body]

[0180] By melt-blending the thermoplastic elastomer composition of the present invention, and preferably by injection molding the blend, a bonding component can be manufactured.

[0181] The composite molded body of the present invention is a composite molded body composed of a joining member and a joined member, wherein the joining member is formed from a first thermoplastic elastomer composition which is the thermoplastic elastomer composition of the present invention, and the joined member is formed from a second thermoplastic elastomer composition. It is generally manufactured by melt-kneading the thermoplastic elastomer composition of the present invention and injection molding the mixture onto the joined member formed from the second thermoplastic elastomer composition, such as an extruded member.

[0182] Furthermore, the composite molded body of the present invention is a composite molded body composed of a joining member and a joined member. The joining member is formed from a first thermoplastic elastomer composition, and the joined member is formed from a second thermoplastic elastomer composition. The first thermoplastic elastomer composition is a thermoplastic elastomer composition with an island structure in which a styrene elastomer (A) exists as an island phase in the marine phase of an propylene resin (B). The second thermoplastic elastomer composition contains a thermoplastic elastomer containing an propylene resin. When the first thermoplastic elastomer composition is used as a test thermoplastic elastomer composition and the second thermoplastic elastomer composition is used as a thermoplastic elastomer composition for insert materials, the tear elongation measured by the tear elongation determination method of the present invention described above is 230% or more.

[0183] In this composite molded article, from the viewpoint of maintaining weldability and weld durability while ensuring heat resistance, it is preferable that the acrylic resin (B) is composed of crystalline polypropylene (B1) and non-crystalline polypropylene (B2). When the total of crystalline polypropylene (B1) and non-crystalline polypropylene (B2) is set at 100% by mass, the content of crystalline polypropylene (B1) is 70% by mass or more and 90% by mass or more, and the content of non-crystalline polypropylene (B2) is 10% by mass or more and 30% by mass or less. From these viewpoints, the content of crystalline polypropylene (B1) in the total of 100% by mass of crystalline polypropylene (B1) and non-crystalline polypropylene (B2) is more preferably 75% by mass or more and 85% by mass or less, and the content of non-crystalline polypropylene (B2) is more preferably 15% by mass or more and 25% by mass or less.

[0184] The bonded component constituting the composite molded body of the present invention is preferably formed of an olefin-based rubber. Examples of olefin-based rubbers include olefin-based thermoplastic elastomers and sulfur-cured rubber. From the viewpoint of obtaining good weldability, it is preferable to use a thermoplastic elastomer composition containing an propylene-based resin as the marine phase.

[0185] Thermoplastic elastomer composition containing acrylic resin as the marine phase, which constitutes the joined component, is preferably a thermoplastic elastomer composition with a Shore A hardness of 75 to 85 and a melting point of 133 to 143°C.

[0186] Because of the excellent weldability of the thermoplastic elastomer composition of the present invention, and the excellent mechanical strength and compression set (fatigue resistance) of the frame portion of the glass guide channel for automobiles, olefin-based thermoplastic elastomers and styrene-based thermoplastic elastomers are preferred as the thermoplastic elastomers used in the joined components, with olefin-based dynamically crosslinked thermoplastic elastomers being more preferred.

[0187] Olefin-based dynamically crosslinked thermoplastic elastomer compositions containing propylene resins as the marine phase are available as commercially available products. Examples of suitable commercially available products include, for instance, "TREXPRENE (registered trademark)" manufactured by Mitsubishi Chemical Corporation. Appropriate products can be selected from these.

[0188] In particular, the composite molded body of the present invention is suitable as a composite molded body for automotive glass guide channels, etc.

[0189] Figure 1 This is a perspective view showing an example of a glass guide channel for automobiles as a composite molded body 3. The composite molded body 3 is formed by fusing together the corner portions of the joined members 1A and 1B, which are separately manufactured by extrusion molding of a thermoplastic elastomer composition and constitute linear portions, through the corner portions of the joined members 2 formed from the thermoplastic elastomer composition of the present invention.

[0190] Such a composite molded body 3 can be manufactured, for example, by inserting the pre-made joining end sides of the joined members 1A and 1B into an injection molding mold, and then injecting the thermoplastic elastomer composition of the present invention into the mold to form the corner joining member 2, and then fusing it integrally with the end faces of the joined members 1A and 1B.

[0191] Example

[0192] The present invention will be further described in detail below using examples. The present invention is not limited to the following examples without departing from its spirit. The various manufacturing conditions and evaluation results in the following examples have the meaning of preferred values ​​as upper or lower limits in the embodiments of the present invention, and the preferred range may also be a range defined by the values ​​of the above-mentioned upper or lower limits and the values ​​of the following examples or the values ​​of each other in the examples.

[0193] [raw materials]

[0194] The raw materials used in the following examples and comparative examples are shown below.

[0195] [Styrene-based elastomers (A)]

[0196] <a-1>

[0197] Styrene-butadiene-styrene hydrogenated block copolymer (having the structure of formula (I) above. Styrene (block P) content: 32% by mass, weight average molecular weight: 260,000) / "TAIPOL (registered trademark)-6151" manufactured by Taiwan Synthetic Rubber Co., Ltd.

[0198] [Acrylic Resin (B)]

[0199] <Crystallized Polypropylene (B1)>

[0200] <b1-1>

[0201] Propylene-ethylene copolymer (MFR (JIS K7210): 1.3 g / 10 min (230℃, 21.2 N), melt peak temperature: 149℃, propylene unit content: 97% by mass, ethylene unit content: 3% by mass) / "NOVATEC (registered trademark) PP EG7F" manufactured by Nippon Polypropylene Co., Ltd.

[0202] <Amorphous Polypropylene (B2)>

[0203] <b2-1>

[0204] Propylene-ethylene copolymer (MFR (JIS K7210): 8 g / 10 min (230 °C, 21.2 N), melt peak temperature: 75 °C, propylene unit content: 91% by mass, ethylene unit content: 9% by mass) / "Vistamaxx (registered trademark) 3980FL" manufactured by ExxonMobil Chemical Company

[0205] <b2-2>

[0206] Propylene-ethylene copolymer (MFR (JIS K7210): 2 g / 10 min (230 °C, 21.2 N), melt peak temperature: 65 °C, propylene unit content: 89% by mass, ethylene unit content: 11% by mass) / "Vistamaxx (registered trademark) 3020FL" manufactured by ExxonMobil Chemical Company

[0207] [Organosilicon-based lubricant (C)]

[0208] <c-1>

[0209] Silicone oil / "KF96-1000CS" manufactured by Shin-Etsu Chemical Co., Ltd.

[0210] [Softener for Hydrocarbon-Based Rubber (D)]

[0211] <d-1>

[0212] Paraffin-based rubber softener (kinematic viscosity at 40°C: 95.5 cSt, flash point: 272°C) / "DIANA (registered trademark) PROCESS OIL PW90" manufactured by Idemitsu Kosan Co., Ltd.

[0213] [Antioxidant (E)]

[0214] <e-1>

[0215] Phenolic antioxidant / "IRGANOX (registered trademark) 1010" manufactured by BASF Japan Co., Ltd.

[0216] [Evaluation Method]

[0217] The evaluation methods for the thermoplastic elastomer compositions in the following examples and comparative examples are described below.

[0218] In the following measurements (1) to (5), the sheet material obtained as follows was used: a sheet material (120 mm wide, 80 mm long, and 2 mm thick) obtained by injection molding using each thermoplastic elastomer composition and using a coaxial reciprocating screw injection molding machine ("IS130" manufactured by Toshiba Machine Co., Ltd.) under the conditions of injection pressure of 50 MPa, barrel temperature of 220 °C and mold temperature of 40 °C.

[0219] (1) Shore A hardness: The value was determined 15 seconds after the test piece was pressed, according to JIS K6253 (JIS-A).

[0220] The Shore A hardness for automotive sealing materials is 35–95, with a particularly preferred range of 40–98.

[0221] (2) Tensile stress at fracture: As a strength indicator of the thermoplastic elastomer composition, the tensile stress at fracture is measured according to the procedure for determining tensile stress at fracture based on JIS K 6251. The higher the value of the tensile stress at fracture, the better the tensile properties required for the thermoplastic elastomer composition.

[0222] (3) Elongation at break: As a strength indicator of the thermoplastic elastomer composition, the elongation at break is measured according to the procedure for determining elongation at break based on JIS K 6251. The higher the value of the elongation at break, the better the tensile properties required for the thermoplastic elastomer composition.

[0223] (4) Compression set: The compression set was measured according to JIS K6262 at 70°C for 22 hours under 25% compression. The smaller the compression set value, the better the durability.

[0224] (5) Coefficient of dynamic friction and coefficient of static friction

[0225] A sheet (120mm wide, 80mm long, 2mm thick) obtained by injection molding was cut into 60cm × 45cm pieces. A 200g weight (110mm long × 110mm wide × 3mm thick), attached to a glass plate with double-sided tape, was moved 6cm on the test piece to determine the static and dynamic coefficients of friction. The measurements were performed three times, and the average value was calculated.

[0226] The smaller the values ​​of the dynamic friction coefficient and the static friction coefficient, the better the sliding performance required for the thermoplastic elastomer composition.

[0227] (6) Weld strength and elongation at sea of ​​thermoplastic elastomer compositions containing propylene resin as the marine phase: A 2mm thick injection-molded sheet of a thermoplastic elastomer composition containing propylene resin as the marine phase ("TREXPRENE (registered trademark) 3855N", dynamically crosslinked thermoplastic elastomer manufactured by Mitsubishi Chemical Corporation) was cut into 10cm × 5cm pieces and placed into the mold of a 110-ton injection molding machine. Each thermoplastic elastomer composition was injected into the mold at a barrel temperature of 210°C and a mold temperature of 40°C, and a composite molded body was obtained by insert molding. The composite molded body was punched into a dumbbell shape using JIS No. 3 die, and its tensile strength, weld strength, and elongation at sea speed of 200mm / min at 23°C were measured.

[0228] The higher the values ​​of weld strength and weld elongation, the better the weldability required for the joint components.

[0229] (7) Tear strength and elongation at break of the thermoplastic elastomer composition containing acrylic resin as the marine phase. A 2mm thick injection-molded sheet of the thermoplastic elastomer composition containing acrylic resin as the marine phase ("TREXPRENE (registered trademark) 3855N" manufactured by Mitsubishi Chemical Corporation, a dynamically crosslinked thermoplastic elastomer) was cut into 10cm × 5cm pieces and placed into the mold of a 110-ton injection molding machine. Each thermoplastic elastomer composition was injected into the mold at a barrel temperature of 260°C and a mold temperature of 40°C, and a composite molded body was obtained by insert molding. The composite molded body was then punched into a JIS K6252 non-cut right-angled dumbbell shape, such as... Figure 2 As shown, markings 10a and 10b are drawn 10 mm from the weld interface 10C, with a total distance of 20 mm between the markings. Then, the material is stretched at 23°C and a tensile speed of 200 mm / min to determine the tear strength and elongation at break.

[0230] For tear elongation, the following criteria shall be used for evaluation:

[0231] ◎: Tear elongation is 250% or more;

[0232] ○: Tear elongation is ≥230% and <250%;

[0233] ×: Tear elongation is less than 230%.

[0234] This evaluation assesses the weld durability of injection-molded sheets, but based on the results, it is also possible to determine the weld durability of the manufactured sheets. Figure 1 The weld durability of the composite molded body shown is compared with the weld strength and weld elongation of (6), and the good performance is evaluated.

[0235] [Example / Comparative Example]

[0236] <Example 1>

[0237] 100 parts by weight of (A-1), 69 parts by weight of (B1-1), 14 parts by weight of (B2-1), 5.6 parts by weight of (C-1), 94 parts by weight of (D-1), and 0.28 parts by weight of (E-1) were mixed in a Henschel mixer for 1 minute to obtain a mixture. This mixture was then fed into the feed section of a co-rotating twin-screw extruder ("TEX30α", manufactured by Nippon Steel Works, L / D = 46, number of barrel groups: 13) at a total rate of 15 kg / h, and melt-blended within the temperature range of 110–220°C, followed by granulation to produce a thermoplastic elastomer composition.

[0238] Transmission electron microscopy confirmed that the obtained thermoplastic elastomer composition formed an island structure with component (B) as the marine phase and component (A) as the island phase.

[0239] For the obtained thermoplastic elastomer composition, the melt flow rate (MFR) was determined according to the method based on JIS K7210 standard, at a test temperature of 230°C and a test load of 21.2 N.

[0240] The density of the obtained thermoplastic elastomer composition was determined according to Method A (drainage method) based on ISO 1183.

[0241] The obtained thermoplastic elastomer composition was evaluated as described in (1) to (7) above.

[0242] The evaluation results are shown in Table-1.

[0243] <Examples 2-5 and Comparative Example 1>

[0244] Except for changes to the formulation shown in Table-1, the process was carried out in the same manner as in Example 1 to obtain granules of the thermoplastic elastomer composition. The resulting thermoplastic elastomer compositions were evaluated in the same way as in Example 1. The results are shown in Table-1.

[0245] In Table 1, "(B2) content" refers to the content of non-crystalline polypropylene (B2) in the total of 100% by mass of crystalline polypropylene (B1) and non-crystalline polypropylene (B2).

[0246] [Table 1]

[0247] <Table-1>

[0248]

[0249] <Evaluation Results>

[0250] As shown in Table 1, Examples 1 to 5 exhibit excellent sliding properties, weldability, and weld durability.

[0251] Comparative Example 1 is an example that does not use non-crystalline polypropylene (B2). The weld strength and weld elongation are not much different from those of the Example, but the tear elongation is small and the weld durability is poor.

[0252] Although the invention has been described in detail using specific methods, it will be apparent to those skilled in the art that various modifications can be made without departing from the intent and scope of the invention.

[0253] This application is based on Japanese Patent Application No. 2020-158729, filed on September 23, 2020, which is incorporated herein by reference in its entirety.

[0254] Industrial availability

[0255] The thermoplastic elastomer composition of the present invention can be applied in a wide range of fields, including: automotive parts such as skins, windshields, headliners, interior trim sheets, bumper guards, body guards, air spoilers, air duct hoses, and sealing materials; civil engineering and construction materials such as waterproofing materials, sealant materials, window frames, and sealing materials; sporting goods such as golf club grips and tennis racket grips; industrial parts such as hoses and gaskets; household appliance parts such as hoses and gaskets; medical parts such as medical containers, gaskets, and gaskets; food parts such as containers and gaskets; medical machine parts; wires; and general merchandise. Among the fields listed above, the thermoplastic elastomer composition of the present invention is suitable for use as automotive sealing materials and building material sealing materials, and is particularly suitable for use as automotive sealing materials, especially automotive glass guide channels.

Claims

1. A thermoplastic elastomer composition comprising the following components (A), (B1), (B2), and (C), wherein, Component (A): Styrene-based elastomer; Composition (B1): Crystalline polypropylene; Composition (B2): Non-crystalline polypropylene; Ingredient (C): Organosilicon-based lubricant. Compared to a total of 100 parts by weight of components (A) to (C), the content of other resins besides components (A), (B1), and (B2) is 0 parts by weight or more and 10 parts by weight or less. The silicone-based lubricant (C) is used in the range of 0.5 to 8.3 parts by weight, relative to 100 parts by weight of the styrene-based elastomer component (A). In component (B1) crystalline polypropylene, the content of ethylene units is less than 7% by mass relative to the total number of monomer units constituting component (B1) crystalline polypropylene. In component (B2) amorphous polypropylene, the content of ethylene units is 7% by mass or more and 50% by mass or less, relative to the total number of monomer units constituting component (B2) amorphous polypropylene. When the total of component (B1) and component (B2) is 100% by mass, the content of component (B2) is 10% by mass or more and 30% by mass or less. The mass ratio of component (A) relative to the total mass of components (B1) and (B2) is 1.00 or more and 1.30 or less.

2. The thermoplastic elastomer composition according to claim 1, wherein, The tear elongation, as determined by the following method, is above 230%. <Method for determining tear elongation> The tear elongation at a mark spacing of 20 mm was measured on a JIS K6252 uncut right-angled dumbbell-shaped test piece cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding the thermoplastic elastomer composition of claim 1 at 260°C in an injection molding die filled with an injection-molded sheet containing a thermoplastic elastomer composition containing an acrylic resin as the marine phase. The thermoplastic elastomer composition containing an acrylic resin as the marine phase has a Shore A hardness of 75-85 and a melting point of 133-143°C.

3. The thermoplastic elastomer composition according to claim 1, wherein, The mass ratio of component (A) relative to the total mass of components (B1) and (B2) is 1.10 or more and 1.27 or less.

4. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the compression set measured at 70°C, 22 hours, and 25% compression, as per JIS K6262, is less than 55%.

5. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein, The melt flow rate (MFR) of the component (B2) measured at a temperature of 230°C and a load of 21.2 N was 1–10 g / 10 min.

6. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the elongation at break, as determined with reference to JIS K6251, is 950% or more.

7. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the content of other resins besides components (A), (B1), and (B2) is 0 parts by mass or more and 3 parts by mass or less relative to a total of 100 parts by mass of components (A) to (C).

8. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein, Component (A) styrene-based elastomer is: a block copolymer having at least two polymer blocks mainly composed of vinyl aromatic compounds and at least one polymer block containing butadiene, and / or a hydrogenated product of the block copolymer.

9. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein, The weight-average molecular weight of component (A) styrene-based elastomer, converted from polystyrene as determined by gel permeation chromatography, is 240,000 or more and 430,000 or less.

10. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein, In component (B1) crystalline polypropylene, relative to the total number of monomer units constituting component (B1) crystalline polypropylene, the content of ethylene units is 2% by mass or more and 5% by mass or less, and the content of propylene units is 80% by mass or more and 98% by mass or less.

11. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein, In component (B2) amorphous polypropylene, relative to the total number of monomer units constituting component (B2) amorphous polypropylene, the content of ethylene units is 10% by mass or more and 15% by mass or less, and the content of propylene units is 85% by mass or more and 90% by mass or less.

12. A joining member formed of the thermoplastic elastomer composition according to any one of claims 1 to 11.

13. A corner member for automobiles, comprising the joining member as described in claim 12.

14. A composite molded body comprising a joining member and a joined member, wherein the joining member is formed of a first thermoplastic elastomer composition, and the joined member is formed of a second thermoplastic elastomer composition, wherein... The first thermoplastic elastomer composition is the thermoplastic elastomer composition according to any one of claims 1 to 11.

15. A glass guide channel for automobiles, comprising the composite molded body as described in claim 14.

16. A thermoplastic elastomer composition having a sea-island structure in which a styrene elastomer of component (A) is present as an island phase in a marine phase of a propylene resin of component (B), and having a tear elongation of 230% or more as determined by the following method, wherein component (B) is composed of crystalline polypropylene of component (B1) and amorphous polypropylene of component (B2), and the mass ratio of component (A) is 1.00 or more and 1.30 or less relative to the total mass of components (B1) and (B2). In component (B1) crystalline polypropylene, the content of ethylene units is less than 7% by mass relative to the total number of monomer units constituting component (B1) crystalline polypropylene. In component (B2) amorphous polypropylene, the content of ethylene units is 7% by mass or more and 50% by mass or less, relative to the total number of monomer units constituting component (B2) amorphous polypropylene. When the total of component (B1) and component (B2) is 100% by mass, the content of component (B2) is 10% by mass or more and 30% by mass or less. <Method for determining tear elongation> The tear elongation at intervals of 20 mm between markings was measured on a JIS K6252 uncut right-angled dumbbell-shaped test piece cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding the island-structured thermoplastic elastomer composition at 260°C in an injection molded die containing an acrylic resin as a marine phase thermoplastic elastomer composition as an insert material. The Shore A hardness of the acrylic resin as a marine phase thermoplastic elastomer composition is 75-85, and the melting point is 133-143°C.

17. The thermoplastic elastomer composition according to claim 16, wherein the compression set, as determined by JIS K6262, is less than 55% under conditions of 70°C, 22 hours, and 25% compression.

18. A composite molded body comprising a joining member and a joined member, wherein the joining member is formed of a first thermoplastic elastomer composition, and the joined member is formed of a second thermoplastic elastomer composition, wherein... The first thermoplastic elastomer composition is a thermoplastic elastomer composition with an island structure in which component (A) styrene elastomer exists as an island phase within the marine phase of component (B) propylene resin. The second thermoplastic elastomer composition contains a thermoplastic elastomer containing a propylene resin. Using the first thermoplastic elastomer composition and the second thermoplastic elastomer composition, and measuring the tear elongation by the following method, the tear elongation is 230% or more. Component (B) is composed of crystalline polypropylene (B1) and amorphous polypropylene (B2), and the mass ratio of component (A) to the total mass of components (B1) and (B2) is 1.00 or more and 1.30 or less. In component (B1) crystalline polypropylene, the content of ethylene units is less than 7% by mass relative to the total number of monomer units constituting component (B1) crystalline polypropylene. In component (B2) amorphous polypropylene, the content of ethylene units is 7% by mass or more and 50% by mass or less, relative to the total number of monomer units constituting component (B2) amorphous polypropylene. When the total of component (B1) and component (B2) is 100% by mass, the content of component (B2) is 10% by mass or more and 30% by mass or less. <Method for determining tear elongation> The tear elongation at a mark spacing of 20 mm was measured on a JIS K6252 uncut right-angled dumbbell-shaped test piece cut from the following composite molded body at a test temperature of 23°C and a test speed of 200 mm / min. The composite molded body was obtained by injection molding the first thermoplastic elastomer composition at 260°C in an injection molding die containing the second thermoplastic elastomer composition as an insert material.

19. A glass guide channel for automobiles, comprising the composite molded body as described in claim 18.

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