Method for producing thermoplastic elastomer compositions

Abstract

The present invention relates to a novel method for producing a thermoplastic elastomer composition with low melt viscosity (melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N), which offers excellent productivity and no problems with strength or heat resistance. [Solution] A method for producing a thermoplastic elastomer composition comprising the following components A to C and having a melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N in an extruder capable of carrying out the following steps 1 and 2, comprising: step 1, kneading at least the following component A and the following component B at a temperature 10°C or more higher than the melting point of the following component B; and step 2, kneading the kneaded product obtained in step 1 with the following component C. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

Description

[Technical Field]

[0001] This invention relates to a method for producing thermoplastic elastomer compositions. [Background technology]

[0002] Conventionally, in order to provide a method for automatically applying adhesive to door service hole covers to the inner panel of a door in a safe and short time, a method has been proposed in which a composition is manufactured using a pressure kneader and a hot melt adhesive is applied using a robot equipped with a discharge nozzle (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-86871 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The production of low-melt-viscosity compositions used in hot-melt applications typically employs a batch-type heated-melt-kneading machine called a pressurized kneader, which sequentially adds several raw materials and manufactures the composition while monitoring the mixing process. However, because it is a batch-type process, the kneading time until all raw materials are uniformly mixed is long, and the operation is cumbersome. Therefore, a more productive manufacturing method is desired.

[0005] The present invention relates to a novel method for producing a thermoplastic elastomer composition with low melt viscosity (melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N), which offers excellent productivity and no problems with strength or heat resistance. [Means for solving the problem]

[0006] The present invention relates to the following [1] to [6]. [1] A method for producing a thermoplastic elastomer composition comprising the following components A to C and having a melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N in an extruder capable of carrying out the following steps 1 and 2, comprising: step 1, kneading at least the following component A and the following component B at a temperature 10°C or more higher than the melting point of the following component B; and step 2, kneading the kneaded product obtained in step 1 with the following component C. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener [2] The manufacturing method according to [1], further comprising a pelletizing step of cutting the kneaded material obtained in step 2 into pellets to obtain pellets of the thermoplastic elastomer composition. [3] The manufacturing method according to [2], wherein the pelletizing step is a step of cutting the kneaded material with an underwater cutting type pelletizer. [4] The manufacturing method according to any one of [1] to [3], wherein the elongation at the breaking point of the thermoplastic elastomer composition is 200% or more. [5] The thermoplastic elastomer composition is a composition for forming a composite by heat-fusion to a resin molded product, a rubber molded product, or a metal molded product, the manufacturing method according to any one of [1] to [4]. A method for producing a composite, comprising the step of applying a thermoplastic elastomer composition obtained by any of the manufacturing methods described in [6][1] to [5] to a resin molded product, a rubber molded product, or a metal molded product using a hot melt coating. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a method for producing a novel thermoplastic elastomer composition with low melt viscosity that is highly productive and has no problems with strength or heat resistance. [Modes for carrying out the invention]

[0008] The present inventors investigated the continuous production of a low-melt-viscosity thermoplastic elastomer composition containing a hydrogenated block copolymer, a crystalline polyolefin resin, and a softening agent using an extruder. They discovered that, compared to production using a batch-type heated melt kneader (hereinafter also referred to as a "batch mixer"), the elongation at the breaking point of the thermoplastic elastomer composition was lower, resulting in strength problems. Therefore, the present inventors diligently investigated how to solve this new problem, and found that... Surprisingly, we have newly discovered that a thermoplastic elastomer composition with no strength issues can be obtained by melt-kneading a hydrogenated block copolymer and a crystalline polyolefin resin under specific temperature conditions, and then adding a softener to the resulting mixture and melt-kneading it again. Although the mechanism is not yet clear, the hydrogenated block copolymer is mechanically and thermally reinforced by being mixed with the crystalline polyolefin resin. However, strong shear force is required in a heated, molten state to mix the hydrogenated block copolymer and the crystalline polyolefin resin. However, when the mixture is kneaded with a softener that plays a role in adjusting flexibility and fluidity while maintaining good miscibility with the hydrogenated block copolymer in excess relative to the weight-average molecular weight of the hydrogenated block copolymer, the melt viscosity of the hydrogenated block copolymer decreases, and strong shear force cannot be obtained. As a result, it is presumed that the dispersion and mixing of the hydrogenated block copolymer with the crystalline polyolefin resin is insufficient, and the reinforcing effect on the hydrogenated block copolymer is not fully exerted.

[0009] Furthermore, it has been newly discovered that pellets of thermoplastic elastomer compositions can be obtained according to a preferred manufacturing method of the present invention. In manufacturing methods using batch mixers, it is difficult to produce pelletized compositions, and conventional thermoplastic elastomer compositions for hot melt applications have been supplied in block or sheet form. However, block and sheet forms require cutting during use, which is extremely cumbersome. On the other hand, in a preferred manufacturing method of the present invention, it is possible to provide thermoplastic elastomer compositions for hot melt applications in pellet form, thus offering superior handling. Here, pellets refer to small tablet-like, cylindrical, or rice-grain-like granular forms.

[0010] The present invention relates to a method for producing a thermoplastic elastomer composition containing the following components A to C and having a melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N, in an extruder capable of carrying out the following steps 1 and 2, comprising: step 1 (hereinafter also referred to as "kneading step 1"), in which at least the following component A and the following component B are kneaded at a temperature at least 10°C higher than the melting point of the following component B; and step 2 (hereinafter also referred to as "kneading step 2"), in which the kneaded product obtained in step 1 (also referred to as "kneaded product 1") is kneaded with the following component C. The kneaded product obtained in kneading step 2 is also referred to as kneaded product 2. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

[0011] Component A in the manufacturing method of the present invention is a hydrogenated block copolymer containing polymer block a and polymer block b, which are described in detail below. Component A imparts mechanical and thermal properties, as well as the melt viscosity of the thermoplastic elastomer composition according to the manufacturing method of the present invention.

[0012] The polymer block a contains a structural unit derived from an aromatic vinyl compound. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinyl naphthalene, etc., and two or more of these may be used in combination. Among these, styrene, which is easily available, is preferable.

[0013] The polymer block a may contain a compound other than the aromatic vinyl compound as a monomer as long as the effects of the present invention are not impaired. Examples of such a compound include ethylene, acrylonitrile, acrylic ester, vinyl acetate, etc.

[0014] The proportion of the structural unit derived from the aromatic vinyl compound in all the structural units constituting the polymer block a is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more.

[0015] The content of the structural unit derived from the aromatic vinyl compound in Component A is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more from the viewpoint of compression set. On the other hand, it is preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less from the viewpoints of flexibility and sealing property. In this specification, the content of the structural unit derived from the aromatic vinyl compound can be measured by the method described in the examples.

[0016] The polymer block b contains a structural unit derived from a conjugated diene compound. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, etc., and two or more of these may be used in combination.

[0017] The polymer block b may contain a compound other than the conjugated diene compound as a monomer as long as the effects of the invention are not impaired. Examples of such a compound include styrene, α-olefin, isobutylene, farnesene, etc.

[0018] The proportion of the structural units derived from the conjugated diene compound in all the structural units constituting the polymer block b is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more. In the present specification, the content of the structural units derived from the conjugated diene compound can be measured by the method described in the Examples.

[0019] The hydrogenated block copolymer of Component A contains at least one polymer block a and at least one polymer block b.

[0020] In Component A, the bonding form of the polymer block a and the polymer block b is not particularly limited, and it may be any of linear, branched, radial, or a combination of two or more of them. However, from the viewpoints of melt viscosity and mechanical strength, a linearly bonded form is preferred. When the polymer block a is represented by "A" and the polymer block b is represented by "B", (A - B) l , A - (B - A) m , A - (B - A) n -A, B - (A - B) n (wherein l, m, and n each independently represent an integer of 1 or more) is preferably the bonding form, and from the viewpoint of compression set, (A - B) l and A - (B - A) m , A - (B - A) n -A is more preferably the bonding form represented, and the bonding form of the triblock structure represented by A - B - A is still more preferably.

[0021] Also, when Component A has two or more polymer blocks a or two or more polymer blocks b, the respective polymer blocks a and polymer blocks b may be blocks having the same constitution or different constitutions from each other. For example, in the triblock structure represented by [A - B - A], the two polymer blocks A may have the same or different types of aromatic vinyl compounds constituting them.

[0022] Also, when Component A is (A - B) l , A - (B - A) m, A-(BA) n -A, B-(AB) n The compound may contain two or more block copolymers with different bonding configurations (wherein l, m, and n each represent an integer of 1 or more). The compound is a diblock (AB). l If it is included, from the viewpoint of compression set, it is preferably 30% by mass or less, more preferably 10% by mass or less, and even more preferably 1% by mass or less in component A.

[0023] In component A, the mass ratio of polymer block a to polymer block b (polymer block a / polymer block b) is preferably 5 / 95 to 70 / 30, more preferably 10 / 90 to 50 / 50, and even more preferably 15 / 85 to 40 / 60, from the viewpoint of flexibility and mechanical strength.

[0024] Component A is essentially a polymer block b in which some or all of the unsaturated double bonds (carbon-carbon double bonds) have been hydrogenated. The hydrogenation rate of polymer block b is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. In the present invention, the hydrogenation rate of polymer block b can be determined by 1H-NMR spectroscopy. Component A may optionally have one or more functional groups such as a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group, or an epoxy group in its molecular chain and / or at its molecular terminals, as long as it does not impair the effects of the present invention.

[0025] Specific examples of component A include styrene-ethylene-butylene block copolymer (SEB), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene block copolymer (SEP), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene block copolymer (SEEP), styrene-(ethylene-ethylene-propylene)-styrene block copolymer (SEEPS), (α-methylstyrene)-ethylene-butylene block copolymer, and (α-methylstyrene)-ethylene-butylene-(α-methylstyrene) block copolymer, among other styrene-based elastomers. These may be used individually or as a mixture of two or more, but from the viewpoint of compression set and melt viscosity, SEBS, SEPS, and SEEPS are preferred, with SEBS and SEEPS being more preferred.

[0026] From the viewpoint of compression set, the weight-average molecular weight of component A is preferably 20,000 or more, more preferably 30,000 or more, and even more preferably 50,000 or more. On the other hand, from the viewpoint of melt viscosity, the weight-average molecular weight of component A is preferably 400,000 or less, more preferably 150,000 or less, and even more preferably 80,000 or less. In this specification, the weight-average molecular weight (Mw) of component A can be measured by the method described in the examples.

[0027] The content of component A in the kneaded product 1 obtained in kneading step 1 is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of melt viscosity and compression set, while preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0028] The content of component A in the kneaded product 2 obtained in the kneading step 2 is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of melt viscosity and compression set, while preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less.

[0029] The difference in the content of component A contained in compound 1 and compound 2 (compound 1 - compound 2) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of miscibility, while preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0030] Component A can be manufactured by conventionally known methods. Component A is available as a commercially available product. Examples of commercially available products include the Kraton G series, Kraton FG series, Kraton MD series, and Kraton A series from Kraton Polymers, the ToughTec series and SOE series from Asahi Kasei, and the Septon series and Hybler series from Kuraray.

[0031] Component B in the manufacturing method of the present invention is a crystalline polyolefin resin. When component B is mixed with component A, an improvement in compression set is achieved. Here, resin refers to a polymer, which is a polymer in which monomers constituting the polymer exceed a thousand units, while a polymer in which monomers are polymerized to several hundred to a thousand units is generally called an oligomer. Due to these differences in molecular weight, component B, being a resin, has high crystallinity due to its molecular weight and constituent monomers, and therefore has higher viscosity, melting point, and heat of fusion compared to, for example, oligomers such as polyethylene wax and polypropylene wax. This characteristic allows for mechanical and thermal reinforcement effects to be imparted to the thermoplastic elastomer composition according to the manufacturing method of the present invention.

[0032] Examples of crystalline polyolefin resins that can be used as component B include known ones such as polyethylene homopolymers, polypropylene homopolymers, ethylene-propylene copolymers, α-olefin copolymers, and polyolefin resins modified with polar groups such as maleic acid. Among these, polypropylene homopolymers and ethylene-propylene copolymers are preferred from the viewpoint of compression set. From the viewpoint of miscibility, polypropylene homopolymers are even more preferred.

[0033] The melting point of component B is preferably 110°C or higher from the viewpoint of compression set, and preferably 200°C or lower from the viewpoint of miscibility. From these viewpoints, the melting point range of component B is more preferably 130 to 190°C, even more preferably 150 to 180°C, and even more preferably 160 to 170°C. In this specification, the melting point can be measured by the method described in the examples.

[0034] The heat of fusion (ΔH) of component B is 20 J / g or more. From the viewpoint of compression set, the heat of fusion is preferably 60 J / g or more, more preferably 82 J / g or more, and even more preferably 85 J / g or more. On the other hand, from the viewpoint of miscibility, the heat of fusion is preferably 150 J / g or less, more preferably 110 J / g or less, and even more preferably 100 J / g or less. In this specification, the heat of fusion can be measured by the method described in the examples.

[0035] The melt mass flow rate of component B at 230°C and 21.2N is an indicator that correlates with the molecular weight, for example, when component B is a homopolymer. A higher melt mass flow rate, i.e., a lower melt viscosity, corresponds to a lower molecular weight of component B. The miscibility between the polymer components, component A and component B, is better as the molecular weight decreases, and at the same time, the melt viscosity of the resulting thermoplastic elastomer composition can be reduced. On the other hand, if the molecular weight of component B becomes too low, the crystallinity of component B decreases. For these reasons, from the viewpoint of miscibility, a melt mass flow rate of 10 g / 10 min or more is preferred, and from the viewpoint of compression set, a melt mass flow rate of 5000 g / 10 min or less is preferred. From these viewpoints, the range of the melt mass flow rate of component B is preferably 30 to 3000 g / 10 min, more preferably 50 to 2500 g / 10 min, and even more preferably 100 to 2000 g / 10 min. In this specification, the melt mass flow rate can be measured by the method described in the examples.

[0036] From the viewpoint of melt viscosity and compression set, the ratio of component A to component B used in the kneaded product 1 of kneading step 1 is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, of component B per 100 parts by mass of component A. On the other hand, from the viewpoint of flexibility, the ratio of component B per 100 parts by mass is preferably 150 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 80 parts by mass or less, of component B per 100 parts by mass of component A.

[0037] The content of component B in the kneaded product 1 obtained in kneading step 1 is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of melt viscosity and compression set, while from the viewpoint of flexibility it is preferably 70% by mass or less, more preferably 55% by mass or less, and even more preferably 45% by mass or less.

[0038] The content of component B in the kneaded product 2 obtained in the kneading step 2 is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of melt viscosity and compression set, while from the viewpoint of flexibility it is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0039] The difference in the content of component B contained in compound 1 and compound 2 (compound 1 - compound 2) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, from the viewpoint of miscibility, while preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0040] Component B can be manufactured by conventionally known methods. Component B is available commercially. Examples of commercially available products include the PM series from Sun Allomer Co., Ltd., the Novatec PP series from Nippon Polypropylene Co., Ltd., and the Prime Polypropylene series from Prime Polymer Co., Ltd.

[0041] Component C in the manufacturing method of the present invention is a softening agent. Examples of component C include mineral oil-based softening agents such as paraffinic oils, naphthenic oils, and asphaltic oils; polyolefin synthetic softening agents such as 1-decene oligomers; plant-derived synthetic softening agents such as β-farnesene oligomers; vegetable oil-based softening agents such as fatty oils, pine root oils, tall oils, and Factis; coal tar-based softening agents such as tars and coumarone indene resins; and liquid or low molecular weight synthetic resins such as phenolic resin low condensates, low melting point styrene resins, polybutenes, and tertiary butylphenol acetylene condensates. Among these, paraffinic oils, polyolefin synthetic softening agents, and plant-derived synthetic softening agents are preferred from the viewpoint of melt viscosity and miscibility.

[0042] The kinematic viscosity of component C at 40°C is 10 mm from the standpoint of volatility. 2 Preferably 50,000 mm / s or more, and from the viewpoint of bleed-out. 2 Preferably less than / s, and 10000mm 2 / s or less is more preferable, and 1000mm 2 / s or less is even more preferable, and 500mm 2 A value of less than or equal to / s is even more preferable. From this viewpoint, the kinematic viscosity is preferably 20 to 300 mm². 2 / s, more preferably 30-200mm 2 / s, more preferably 50-100 mm 2 It is / s.

[0043] The amount of component C used in the manufacturing method of the present invention is preferably 5 parts by mass or more, from the viewpoint of melt viscosity, and preferably 800 parts by mass or less, from the viewpoint of bleed-out, per 100 parts by mass of component A in the thermoplastic elastomer composition. From these viewpoints, the amount of component C used is preferably 5 to 800 parts by mass, more preferably 10 to 700 parts by mass, even more preferably 15 to 600 parts by mass, even more preferably 20 to 500 parts by mass, and even more preferably 25 to 400 parts by mass, per 100 parts by mass of component A.

[0044] From the viewpoint of melt viscosity, the content of component C in the thermoplastic elastomer composition is preferably 10% by mass or more, and from the viewpoint of bleed-out, it is preferably 90% by mass or less. From this viewpoint, the content of component C in the thermoplastic elastomer composition is preferably 15 to 80% by mass, more preferably 20 to 65% by mass, and even more preferably 25 to 70% by mass.

[0045] In the manufacturing method of the present invention, component C is used in at least the kneading step 2 and is contained in the kneaded product 2, and it is also acceptable for a portion of the component C used to be contained in the kneaded product 1. The amount of component C used and the content mentioned above refer to the total amount of component C. The amount of component C used in the kneading step 2 is preferably 5 parts by mass or more from the viewpoint of melt viscosity, and preferably 400 parts by mass or less from the viewpoint of bleed-out, per 100 parts by mass of component A. From these viewpoints, it is preferably 5 to 500 parts by mass, more preferably 10 to 400 parts by mass, even more preferably 15 to 300 parts by mass, even more preferably 20 to 250 parts by mass, and even more preferably 25 to 200 parts by mass.

[0046] When component C is included in the kneaded product 1, the shear rate during kneading in the kneading step 1 is also affected by the weight-average molecular weight of component A. Therefore, from the viewpoint of miscibility between component A and component B, when the weight-average molecular weight of component A is between 20,000 and less than 100,000, the amount of component C in the kneaded product 1 is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of component A. Furthermore, when the weight-average molecular weight of component A is between 100,000 and 400,000, the amount of component C in the kneaded product 1 is preferably 400 parts by mass or less, more preferably 300 parts by mass or less, and even more preferably 250 parts by mass or less, per 100 parts by mass of component A.

[0047] The total content of component A, component B, and component C in the thermoplastic elastomer composition according to the manufacturing method of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, from the viewpoint of compression set. The upper limit may be 100% by mass, but in embodiments that include other components, the amount may be 98% by mass or less, 97% by mass or less, or 96% by mass or less.

[0048] The thermoplastic elastomer composition according to the manufacturing method of the present invention may further contain an antioxidant as component D. Examples of component D include hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, aromatic amine antioxidants, etc. By incorporating an antioxidant, the effect of preventing a decrease in the mechanical properties of the thermoplastic elastomer composition due to thermal degradation is achieved. Component D may be used in either kneading step 1 or kneading step 2.

[0049] Examples of hindered phenol antioxidants include 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, hydroxymethyl-2,6-di-t-butylphenol, 2,6-di-t-α-dimethylamino-p-cresol, 2,5-di-t-butyl-4-ethylphenol, 4,4'-bis(2,6-di-t-butylphenol), 2,2'-methylene-bis-4-methyl-6-t-butylphenol, 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), and 4,4 '-Methylene-bis(6-t-butyl-o-cresol), 4,4'-Methylene-bis(2,6-di-t-butylphenol), 2,2'-Methylene-bis(4-methyl-6-cyclohexylphenol), 4,4'-Butylidene-bis(3-methyl-6-t-butylphenol), 4,4'-Thiobis(6-t-butyl-3-methylphenol), Bis(3-methyl-4-hydroxy-5-t-butylbenzyl) sulfide, 4,4'-Thiobis(6-t-butyl-o-cresol), 2,2'-Thiobis(4-methyl-6-t-butylphenol), 2,6-Bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol, 3,5-di-t-butyl-4-hydroxybenzenesulfonate diethyl ester, 2,2'-dihydroxy-3,3'-di(α-methylcyclohexyl)-5,5'-dimethyl-diphenylmethane, α-octadecyl-3(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, 6-(hydroxy-3,5-di-t-butylanilino)-2,4-bis-octyl-thio-1,3,5-triazine, hexamethylene glycol - Bis[β-(3,5-di-t-butyl-4-hydroxyphenol)propionate], N,N'-hexamethylene-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamic acid amide), 2,2-thio[diethyl-bis-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,5-di-t-butyl-4-hydroxybenzenephosphonate dioctadecyl ester, tetrakis[methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6-tris(3,Examples include 5-di-t-butyl-4-hydroxybenzyl)benzene, 1,1,3-tris(2-methyl-4-hydroxy-5-di-t-butylphenyl)butane, tris(3,5-di-t-butyl-4-hydroxyphenyl)isocyanurate, and tris[β-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl-oxyethyl]isocyanurate, among which those with a molecular weight of 500 or more, such as tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, are preferred.

[0050] Examples of phosphorus-based antioxidants include phosphite compounds and phosphate compounds, among which phosphite compounds are preferred.

[0051] Examples of phosphite compounds include tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,6-hexamethylene-bis(N-hydroxyethyl-N-methyl semicarbazide)-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-1,10-decamethylene-di-carboxylic acid-di-hydroxyethyl carbonylhydrazide-diphosphite, and tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl] Examples include [phenyl]-1,10-decamethylene-di-carboxylic acid-di-salisiloylhydrazide-diphosphite, tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-di(hydroxyethylcarbonyl)hydrazide-diphosphite, and tetrakis[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5'-t-butylphenyl)-5-methylphenyl]-N,N'-bis(hydroxyethyl)oxamide-diphosphite, but in the present invention, phosphite compounds in which at least one PO bond or P=O bond is bonded to an aromatic group are preferred.Examples of such phosphite compounds include tris(2,4-di-t-butylphenyl) phosphite, tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylene phosphate, bis(2,4-di-t-butylphenyl)pentaerythritol-di-phosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-di-phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, and 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl). Examples include triphenyl-di-tridecyl) phosphite, 1,1,3-tris(2-methyl-4-ditridecylphosphite-5-t-butylphenyl)butane, tris(mixed mono and di-nonylphenyl) phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenebis(phenyl-dialkylphosphite), 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, etc.

[0052] Examples of sulfur-based antioxidants include sulfur-containing compounds such as thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, and thiodipropion esters, with thioethers being preferred among these. Thioether antioxidants are compounds having at least one thioether bond in their molecular structure. Specifically, examples of thioether antioxidants include dilong-chain alkylthiodipropionates (dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, etc.) and tetrakis[methylene-3-(long-chain alkylthio)propionate]alkanes (e.g., tetrakis[methylene-3-(dodecylthio)propionate]methane, etc.). Long-chain alkyl groups include linear or branched alkyl groups having 8 to 20 carbon atoms. These thioether antioxidants can be used individually or in combination of two or more.

[0053] Examples of aromatic amine antioxidants include phenylnaphthylamine, 4,4'-dimethoxydiphenylamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, and 4-isopropoxydiphenylamine. Among these, aromatic secondary amine compounds are preferred, and diphenylamine compounds are more preferred.

[0054] The amount of component D used is preferably 0.05 to 20 parts by mass, preferably 0.07 to 7 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of component A.

[0055] The amount of component D used in the manufacturing method of the present invention is preferably 0.01 to 0.8% by mass, more preferably 0.03 to 0.3% by mass, in the thermoplastic elastomer composition.

[0056] The thermoplastic elastomer composition according to the manufacturing method of the present invention may optionally contain various additives other than component A, to the extent that they do not impair the effects of the present invention, such as thermoplastic elastomers other than component A, tackifiers, inorganic fillers (e.g., calcium carbonate, talc, silica), organic fillers (e.g., wood flour and cellulose powder, organic fibers), weather stabilizers, ultraviolet absorbers (e.g., benzotriazole, tridiamine, anilide, and benzophenone), heat stabilizers, anti-aging agents, light stabilizers (e.g., hindered amine and benzoate), antistatic agents, nucleating agents, pigments, adsorbents (e.g., metal oxides), metal chlorides (e.g., iron chloride and calcium chloride), hydrotalcite, aluminates, lubricants (e.g., fatty acids, higher alcohols, aliphatic amides and aliphatic esters), flame retardants, foaming agents, and silicone compounds. These components can be optionally added in the manufacturing method of the present invention.

[0057] While tackifiers may be used to impart fusion strength, they tend to cause stickiness. In applications where multiple openings and closings are expected, it is preferable to either omit the tackifier or, if it is included, use a small amount of it, from the viewpoint of preventing a decrease in sealing performance due to the adhesion of dust and other debris. The amount of tackifier used in the manufacturing method of the present invention is preferably 50% by mass or less, more preferably 20% by mass or less, even more preferably 5% by mass or less, and even more preferably 0% by mass, in the thermoplastic elastomer composition. Examples of tackifiers include alicyclic hydrogenated tackifiers, rosin, modified rosin, or esters thereof, aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, copolymer petroleum resins of aliphatic and aromatic components, low molecular weight styrene resins, isoprene resins, alkylphenol resins, terpene resins, and chromanindene resins.

[0058] The A hardness (HsA) of the thermoplastic elastomer composition according to the manufacturing method of the present invention, in accordance with JIS K 6253, is preferably 0 points or higher, more preferably 5 points or higher, and even more preferably 10 points or higher, from the viewpoint of mechanical strength. Furthermore, from the viewpoint of flexibility and sealing properties, it is preferably 90 points or lower, more preferably 70 points or lower, and even more preferably 50 points or lower.

[0059] The melt mass flow rate of the thermoplastic elastomer composition according to the manufacturing method of the present invention at 190°C and a 21.2N load, in accordance with JIS K 7210-1, is 85 g / 10 min or more, preferably 100 g / 10 min or more, from the viewpoint of coating properties.

[0060] The thermoplastic elastomer composition according to the manufacturing method of the present invention preferably has heating and melting characteristics compatible with hot-melt coating machines. For example, thermoplastic elastomer compositions for extrusion molding and injection molding are melted by heating and compression kneading with the strong shear force of a screw. However, thermoplastic elastomer compositions for hot-melt coating are required to melt after being placed in a heating pot and left to stand (without shear). For this reason, the heating and melting temperature without shear of the thermoplastic elastomer composition according to the manufacturing method of the present invention is preferably 120°C or higher, more preferably 140°C or higher, and even more preferably 160°C or higher, from the viewpoint of sealing properties and compression set. Furthermore, from the viewpoint of preventing thermal degradation during coating, it is preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower. The heating and melting temperature is measured at a temperature that can be measured with a Brookfield viscometer.

[0061] The melt viscosity of the thermoplastic elastomer composition according to the manufacturing method of the present invention, as measured by a Brookfield viscometer at 170°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability (dimensional stability during coating). Furthermore, from the viewpoint of coatability, it is preferably 1000 Pa·s or lower, more preferably 500 Pa·s or lower, and even more preferably 100 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition according to the manufacturing method of the present invention, as measured by a Brookfield viscometer at 190°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability. Furthermore, from the viewpoint of coating properties, it is preferably 500 Pa·s or lower, more preferably 100 Pa·s or lower, and even more preferably 50 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition according to the manufacturing method of the present invention, as measured by a Brookfield viscometer at 210°C, is preferably 0.1 Pa·s or higher, more preferably 0.2 Pa·s or higher, and even more preferably 0.5 Pa·s or higher, from the viewpoint of formability. Furthermore, from the viewpoint of coatability, it is preferably 100 Pa·s or lower, more preferably 70 Pa·s or lower, and even more preferably 50 Pa·s or lower. The melt viscosity of the thermoplastic elastomer composition at each temperature is measured using a Brookfield viscometer by the method described in the examples below.

[0062] The tensile strength of the thermoplastic elastomer composition according to the manufacturing method of the present invention is preferably 0.1 MPa or higher, more preferably 0.5 MPa or higher, and even more preferably 0.8 MPa or higher, from the viewpoint of sealing stability against breakage and tearing. The tensile strength of the thermoplastic elastomer composition is measured by the method described in the examples below.

[0063] From the viewpoint of sealing properties, the elongation at the breaking point of the thermoplastic elastomer composition according to the manufacturing method of the present invention is preferably 200% or more, more preferably 250% or more, and even more preferably 300% or more. The elongation at the breaking point of the thermoplastic elastomer composition is measured by the method described in the examples below.

[0064] The thermoplastic elastomer composition according to the manufacturing method of the present invention can be used to obtain a molded article that has resistance to compressive stress (also called compression set). For example, the compression set after 24 hours at 23°C is preferably 50% or less, more preferably 45% or less, and even more preferably 40% or less. Furthermore, the compression set after 24 hours at 70°C is preferably 95% or less, more preferably 90% or less, and even more preferably 85% or less. The compression set can be measured according to the method described in the embodiments below.

[0065] As shown in the examples below, the thermoplastic elastomer composition according to the manufacturing method of the present invention has no problems with strength, heat resistance, or fusion strength to polypropylene resin after hot-melt coating, and is a composition suitable for hot-melt coating. Therefore, the present invention also provides a method for manufacturing a composite, which includes a step of hot-melt coating a component such as a resin molded product, a rubber molded product, or a metal molded product, and the composite obtained thereby. Furthermore, because it has excellent compression set, it can also be used as various sealing materials used for cover materials for service holes in automobile doors, etc. Moreover, the thermoplastic elastomer composition according to the manufacturing method of the present invention is not limited to the above embodiment, and may be used as a thermoplastic elastomer molded article by various known molding methods, such as extrusion molding, press molding, injection molding, calendering, hollow molding, foam molding, and foam injection molding.

[0066] The extruder used in the manufacturing method of the present invention will be described in detail below. In the method for producing the thermoplastic elastomer composition of the present invention, the extruder is configured to perform kneading step 1 and kneading step 2. That is, the thermoplastic elastomer composition can be obtained using a single extruder equipped with an extrusion screw configuration for kneading step 1 and kneading step 2. For example, the thermoplastic elastomer composition of the present invention can also be obtained in a manufacturing method using two extruders, with kneading step 1 and kneading step 2 performed by each extruder. However, from the viewpoint of productivity, such as energy efficiency and the complexity of the work, a manufacturing method using a single extruder is preferred.

[0067] As the extruder used in the manufacturing method of the present invention, a general-purpose extruder can be used, and a multi-screw extruder is preferred from the viewpoint of kneading ability. Furthermore, a twin-screw extruder is more preferred from the viewpoint of handling. From the viewpoint of kneading ability and productivity, a twin-screw extruder equipped with a pair of meshing, co-rotating parallel screws is even more preferred.

[0068] An extruder comprises a cylindrical extrusion barrel and an extrusion screw inserted through the extrusion barrel. The rotation of the extrusion screw transports and mixes the material from the upstream raw material inlet to the extruder outlet (hereinafter also referred to as the "die"). The extrusion barrel is equipped with multiple heating means, each with adjustable temperature settings, towards the upstream raw material inlet and towards the downstream, to heat the material inside the extruder. Furthermore, between the raw material inlet and the die, there is an extrusion barrel with an additional material inlet (hereinafter also referred to as the "side feed"). The extrusion screw has multiple screw components called segments arranged from the upstream to the downstream outlet (die) of the extruder, each designed with different shapes and shear forces. Low-shear progressive screw segments (progressive segments) and high-shear mixing screw segments (mixing segments) are used as segments, and low-shear reverse-feed screw segments (reverse segments) may also be used.

[0069] The extrusion barrel and extrusion screw configuration of the extruder used in the manufacturing method according to the present invention preferably includes a kneading zone configured by continuously arranging a plurality of kneading segments, and a plurality of kneading zones separated by a sequential feed zone configured by continuously arranging a plurality of sequential feed segments, from the viewpoint of the miscibility between component A and component B, and between the kneaded product 1 and component C. More preferably, from the viewpoint of the miscibility between the kneaded product 1 and component C, the extrusion barrel downstream of the kneading zone that is the kneading step 1, which is located at the uppermost of the plurality of kneading zones, is equipped with a side feed for introducing component C, and the component C is kneaded in the kneading zone downstream of the kneading step 1 after being introduced. For example, in this segment configuration, multiple resin materials (e.g., component A and component B) are fed into the extruder and heated in the progressive zone from the uppermost part of the extruder while being transported downstream. In the kneading zone, which is kneading step 1, the multiple resin materials are kneaded with high shear force to form compound 1. Subsequently, after being transported downstream in the progressive zone, compound 1 is kneaded again with a softening agent component C added from the side feed in the kneading zone, which is kneading step 2 to form compound 2. This compound is then transported in the progressive segment and discharged from the die at the extruder outlet.

[0070] From the viewpoint of productivity, the inner diameter of the extrusion barrel of the extruder is preferably 5 mm or more, more preferably 15 mm or more, and even more preferably 40 mm or more. From the viewpoint of handling, it is preferably 100 mm or less, more preferably 80 mm or less, and even more preferably 60 mm or less. From the viewpoint of productivity and kneadability, the ratio of the length (L) to the inner diameter (D) of the extrusion barrel of the extruder is preferably 20 or more, more preferably 30 or more, and even more preferably 40 or more.

[0071] In the manufacturing method of the present invention, a higher saturation rate of molten resin in the space between the extrusion barrel and the screw in the kneading zone of the extruder results in a higher kneading force. From the viewpoint of the kneadability and miscibility of components A, B, and C, the saturation rate is preferably 90% or higher, more preferably 95% or higher, even more preferably 98% or higher, and even more preferably 100%. In the production of the low melt viscosity thermoplastic elastomer composition of the present invention, it is preferable to arrange a reverse feed segment continuously at the downstream end of the kneading zone, which is kneading step 1 or kneading step 2, in order to increase the saturation rate.

[0072] The kneading step 1 is a step in which at least component A and component B are kneaded in a kneading zone within an extruder at a temperature at least 10°C higher than the melting point of component B. In the kneading step 1, in addition to component A and component B, component C, component D, and the above-mentioned optional components may also be used, as long as they do not impair the effects of the present invention. One way to supply component A and component B to the extruder is to supply them quantitatively from a container (hopper) having a funnel-shaped outlet at the bottom (described later) to the raw material inlet of the extruder. From the raw material inlet, component A and component B are heated by the rotation of the screw and sent to the kneading step 1. The kneading temperature is preferably 10 to 150°C higher, more preferably 20 to 120°C higher, and even more preferably 30 to 80°C higher than the melting point of component B, from the viewpoint of sufficiently melting component B and ensuring good miscibility with component A.

[0073] Mixing step 2 is a step in which the mixture 1 and component C are mixed in a mixing zone. Component C can be supplied to the extruder via a side feed. In mixing step 2, in addition to component C, component D, the above-mentioned optional components, etc., may be added, as long as they do not impair the effects of the present invention. The mixing temperature may be the same as that of mixing step 1, or it may be a lower temperature.

[0074] The kneaded material containing the kneaded material 2 obtained in the kneading step 2 is a thermoplastic elastomer composition according to the manufacturing method of the present invention, and can be in the form of pellets, sheets, etc., depending on the application. From the viewpoint of improving the complexity of the hot melt coating process, it is preferable to cut the resin extruded from the extruder into cylindrical or rice-grain sized pellets with a diameter of 10 mm or less and a length of 10 mm or less using a cutter. Since the kneaded material containing the kneaded material 2 has a low melt viscosity, it is preferable that the manufacturing method of the present invention includes a pelletizing step in which the material is cut with an underwater cutting type pelletizer. Here, an underwater cutting type pelletizer is a pelletizer in which the die at the outlet of the extruder and the hole (die) provided in the die from which the kneaded material is extruded are in contact with water, and the heated and molten kneaded material is extruded into the water, and the kneaded material extruded from the die is intermittently cut with a cutter blade that is in contact with the hole (die) of the die. In other words, the heated and molten kneaded material extruded from the die is always in water and is cut and pelletized in water. Furthermore, the pellets, which are cut in water, are transported with the water, then separated by centrifugal force, and the pellets are recovered.

[0075] A preferred embodiment of the manufacturing method of the present invention is shown below. Components A and B, in granular or powdery form, are pre-mixed in a mixer as a blend of powdery and granular substances that can flow within the hopper and be quantitatively supplied to the extruder. (1) Component A and component B are quantitatively fed from the hopper into the extruder raw material inlet. (2) Mix the ingredients from the raw material inlet to the material inlet (side feed) at a temperature at least 10°C higher than the melting point of component B. (3) Supply component C from the material inlet (side feed) (4) The mixture to which component C was supplied in (3) is kneaded from the material input port (side feed) to the die. (5) The mixture extruded from the die is cut into pellets using an underwater cutting pelletizer.

[0076] The pellets obtained by the manufacturing method of this embodiment do not require cutting when used for hot melt applications, and therefore offer superior handling compared to conventional block or sheet-shaped thermoplastic elastomer compositions. [Examples]

[0077] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The various physical properties of the raw materials used in the examples were measured by the following methods.

[0078] <Component A: Hydrogenated block copolymer> [Weight average molecular weight (Mw)] The weight-average molecular weight (Mw) was determined as the weight-average molecular weight in terms of polystyrene by gel permeation chromatography under the following measurement conditions. Measuring device Pump: PU-980, manufactured by JASCO (Japan Spectroscopic Co., Ltd.) • Column oven: Manufactured by Showa Denko Corporation, model AO-50 • Detector: Hitachi L-3300, RI (Differential Refractometer) detector. • Column type: One K-805L (8.0 x 300 mm) and one K-804L (8.0 x 300 mm) column from Showa Denko Corporation are used in series. Column temperature: 40°C • Guard column: KG (4.6 x 10 mm) • Eluent: Chloroform ·Eluent flow rate: 1.0mL / min • Sample concentration: Approximately 1 mg / mL • Sample solution filtration: Disposable polytetrafluoroethylene filter with a pore size of 0.45 μm. • Standard sample for calibration curve: Polystyrene manufactured by Showa Denko Corporation

[0079] [Composition of block copolymer] Proton NMR measurements were performed using a nuclear magnetic resonance spectrometer (BRUKER DPX-400, Germany) to determine the content of constituent units derived from styrene and / or styrene derivatives, for example, by quantifying the characteristic groups of styrene. The content of other monomer units can also be determined by proton NMR measurements.

[0080] <Component B: Crystalline polyolefin resin>

[0081] [Melting point] The melting point was determined in accordance with ISO 11357-3, and the peak melting temperature was measured using a differential scanning calorimeter under a nitrogen atmosphere at a heating rate of 10°C / min.

[0082] [Heat of fusion] The heat of fusion was measured using a differential scanning calorimetry (DSC) analyzer, following the procedure described in JIS K 7122 (1987) for "measuring the heat of fusion after a certain heat treatment" (the heating and cooling rates in the conditioning of the test specimen were both set to 10°C / min).

[0083] [Meltmass Flow Rate (MFR)] The measurements were taken according to the method compliant with JIS K6921-2, under conditions of 230°C and a load of 21.2N.

[0084] <Ingredient C: Softener> [Kinematic viscosity] The viscosity was measured at a temperature of 40°C using a Brookfield-type rotational viscometer in accordance with JIS K 7117-1.

[0085] Examples 1-8, Comparative Examples 1-4 (1) Preparation of thermoplastic elastomer composition (pellets) The raw material compositions shown in Tables 1-3 were used to prepare raw material powder for extruder input. Each component was added to a Kawata Super Mixer SMV-20Ba, heated and mixed at 60-80°C. The extruder, equipped with the screw configuration shown in Tables 1-3, had its extrusion barrel at the raw material inlet set to 130°C, while the other extrusion barrels and dies were set to the extruder temperatures shown in Table 1. The raw material powders of each composition were added to the extruder, and then the amount of component C shown in the side feeds in Tables 1-3 was supplied to the extruder through the material inlet. The residence time was measured after the discharge rate from the extruder stabilized, by adding several black-colored elastomer pellets to the raw material inlet and measuring the time from the addition of the pellets to the extrusion die until the black material was discharged. The residence time can be considered as the mixing time by the extruder. Next, a water-cutting pelletizer was attached to the extruder, and the molten resin discharged from the extruder was cooled in cold water while being cut by a cutter to obtain pellets with a diameter of approximately 3 mm and a thickness of approximately 3 mm.

[0086] <Extrusion mixing conditions> Extruder: Shibaura Machinery Co., Ltd., twin-screw compounding extruder, TEM-26SX-16 / 1V Cylinder temperature: The temperature at the raw material inlet was set to 130°C, and the temperature up to the extruder outlet was set to the extruder temperature shown in Table 1. Screw rotation speed: 600 r / min Number of extrusion barrels: 14 (C1~C14: C1 is the raw material inlet) The feed zone and kneading zone (kneading process 1, kneading process 2) of the extrusion screw were positioned at the locations of the extrusion barrel numbers shown in Tables 1-3.

[0087] In Example 1 and Comparative Examples 2-4, the extruder configuration 2 shown in Table 4 was used. The mixing zones for mixing process 1 and mixing process 2 are located at extrusion barrel numbers C6-C8 and C10, respectively, and the side feed is located at extrusion barrel number C7, between mixing process 1 and mixing process 2.

[0088] Examples 2-8 and Comparative Example 7 used the extruder configuration 1 shown in Table 4. The mixing zones for mixing process 1 and mixing process 2 are located at extrusion barrel numbers C6 and C10, respectively, and the side feed is located at extrusion barrel number C7, between mixing process 1 and mixing process 2.

[0089] In Comparative Example 1, the extruder configuration 3 shown in Table 4 was used. The mixing zones for mixing process 1 and mixing process 2 are located at extrusion barrel numbers C6-C8 and C10, respectively, and the side feed is located at extrusion barrel number C3, upstream of mixing process 1.

[0090] Comparative Examples 5 and 6 In a batch mixer (Bravender Plusgraph 350cc model) set to 190°C, the amounts of components A, B, and D shown in Table 2 were added simultaneously. Mixing was started at a rotor speed of 60 r / min, and while checking the mixing (stability of rotor torque), component C was added sequentially. The mixing (retention) times were 5 minutes and 30 minutes, respectively, after the addition of components A, B, and D.

[0091] (2) Preparation of a 2mm thick sheet Pellets were injection molded under the following conditions to produce a sheet with dimensions of 125 mm in width, 125 mm in length, and 2 mm in thickness.

[0092] <Injection molding conditions> Injection molding machine: EC100SXII-4B (product name, manufactured by Toshiba Machine Co., Ltd.) Injection molding temperature: 160~200℃ Injection pressure: 120 MPa, Holding pressure: 10 MPa Injection time: 2sec Mold temperature: 40℃

[0093] [Table 1]

[0094] [Table 2]

[0095] [Table 3]

[0096] [Table 4]

[0097] Details of the representative components used in the examples and comparative examples are as follows.

[0098] [Table 5]

[0099] [Table 6]

[0100] [Table 7]

[0101] Ingredient c-1: (Product name "PW-90", manufactured by Idemitsu Kosan Co., Ltd.) Component c-2: (Product name "VIVA-B-FIX10227", manufactured by Hansen & Rosenthal, a branched alkane compound)

[0102] Furthermore, the following was used as an antioxidant for component D. Ingredient d-1: (Hindered phenol antioxidant, product name "Irganox 1010", manufactured by BASF Corporation) Ingredient d-2: (Phosphorus-based antioxidant, product name "Irgaphos 168", manufactured by BASF Corporation)

[0103] The following evaluations were performed using pellets or sheets of the thermoplastic elastomer compositions obtained in the examples and comparative examples. The results are shown in Table 1.

[0104] [Hardness (HsA)] Three layers of 2mm thick sheets (total 6mm) were stacked and measured using a Type A durometer in accordance with JIS K 6253. The A hardness (value 15 seconds after the start of the test) was measured over a 15-second period. The measurements were performed in a room at 23°C and 50% humidity after a 1-day conditioning period. A smaller measured value, specifically a value of 90 or less, is preferable as it indicates good sealing properties.

[0105] [Melting viscosity of compositions measured by melt mass flow rate (MFR)] The measurements were taken in accordance with JIS K 7210-1, under test conditions of 190°C and a load of 21.2N.

[0106] [Melting viscosity of the composition measured with a Brookfield viscometer] Measurements were taken at 170°C, 190°C, and 210°C using a Brookfield-type rotational viscometer, in accordance with JIS K 7117-1. A metal test container filled with test pellets was placed in a melt pot set to the test temperature, and the pellets were melted while left undisturbed. Viscosity measurements were performed using a Brookfield viscometer (Eiko Seiki Co., Ltd., RV DV2T) with a spindle No. 27 (Eiko Seiki Co., Ltd., SC4-27). The spindle rotation speed was adjusted within the range of 0.1 to 100 r / min so that the torque value was within the range of 10 to 90% and measured. A lower viscosity value indicates better hot-melt coating properties. If the composition did not melt at these temperatures, or if the viscosity of the melted material was too high to measure, it was evaluated as "unmeasurable".

[0107] [Tensile strength] In accordance with JIS K6251, a No. 3 dumbbell was punched out from a 2mm sheet to serve as the test specimen. The thickness and width of the constricted portion of the dumbbell were defined as the cross-sectional area of ​​the test specimen. Tensile tests were conducted using a Strograph AE manufactured by Toyo Seiki Seisakusho at a tensile speed of 500 mm / min in an environment of 23°C, and the tensile stress was calculated by dividing the measured load cell value (N) by the cross-sectional area of ​​the test specimen.

[0108] [Elongation at the breaking point] In accordance with JIS K6251, a No. 3 dumbbell was punched out from a 2mm sheet to serve as a test specimen. Gauge lines were marked at 20mm intervals on the constricted portion of the dumbbell. A tensile test was conducted using a Toyo Seiki AE Strograph at 23°C with a tensile speed of 500mm / min. The distance between the gauge lines at the time of fracture was measured, and the elongation was calculated by setting the distance between the gauge lines before the test (20mm) as 0%.

[0109] [Compression set rate] A circular sheet measuring 29 mm in diameter and 2 mm in thickness was produced from a 2 mm thick sheet using a 29 mm diameter circular punching die. This sheet was inserted into a cylindrical mold measuring 12.5 mm in height and 29 mm in diameter. A hot press (Toho Machinery Co., Ltd., hydraulic molding machine TB-50-2) heated to 200°C was used to hot press for 5 minutes, followed by a cooling press for 5 minutes to produce a cylindrical test piece measuring 12.5 mm in thickness and 29 mm in diameter. In accordance with JIS K 6262, (1) the compression set rate under conditions of 25% compressibility, 23°C, and 24 hours, and (2) the compression set rate under conditions of 25% compressibility, 70°C, and 24 hours were measured. A smaller set rate indicates that the rebound force is maintained over a long period of time, which is preferable because it indicates good sealing performance over long periods. Specifically, when measured at 23°C, a set rate of 50% or less is preferable, and when measured at 70°C, a set rate of 95% or less is preferable.

[0110] [Fusing strength for non-polar resins (PP fusing strength)] A homopolypropylene (Sun Allomer, PM870A) injection molding plate (2 mm thick x 25 mm wide x 125 mm long) was prepared by dissolving the compositions obtained in each example and comparative example at 180°C and applying them to the plate. A 22.5 mm wide, 2.0 mm thick SEBS (Kraton, G1643) sheet was then placed on top, and a 100 g load was applied while cooling to create a fusion test specimen (composite molded body) with alternating gripping margins. A tensile shear test was performed at a tensile speed of 50 mm / min, and the maximum load per 25 mm width of the specimen was measured. From the viewpoint of substrate adhesion, a larger fusion force is preferable; for example, a force of 10 N / 25 m or more is preferable.

[0111] [Coating properties] The pellets obtained in each example and comparative example were loaded into a melt gun (Hakko MELTER806, 801-NL-S nozzle (discharge hole thickness 0.5 mm, width 5.5 mm)) and coated onto a polypropylene plate substrate. The surface properties of the coated material were visually inspected and evaluated according to the following evaluation criteria. From the viewpoint of discharge stability, the smoother the surface, the better the coating properties. <Evaluation Criteria> ○: A smooth-surfaced coating was obtained with stable dispensing. △: The discharge from the nozzle was pulsating, and there was a wavy surface on the coated material. ×: The molded product could not be obtained because it could not be extruded from the nozzle.

[0112] [Pellet blocking properties] In each example and comparative example, 200g of the pellet sample was placed in an aluminum cylindrical tube with an inner diameter of 100mm and a height of 100mm, leveling it evenly. A 3.7kg stainless steel disc-shaped weight with an outer diameter of 98mm was then placed on top of the pellets. After being left in a 40°C oven for 3 hours, the pellet sample was removed and left overnight at a temperature of 23°C to cool. <Evaluation Criteria> ○: When there are no aggregates △: Aggregates are present, but they can be easily broken up by hand. ×: If there are aggregated clumps that cannot be easily broken up by hand.

[0113] As shown in Tables 1-3, in Examples 1-8, pellets without blocking issues were obtained in approximately 1 minute (residence time in Tables 1-3), and in all cases, the elongation at the breaking point was 200% or more, confirming that there were no problems with the strength after hot melt coating. Furthermore, in Examples 1-8, good results were obtained in terms of compression set at 70°C, confirming that there were no problems with heat resistance.

[0114] In Comparative Example 1, which used extruder configuration 3 and added component C upstream (C3) of the kneading process 1 (C6-C8), poor kneading occurred, resulting in a lower elongation at the breaking point compared to Example 1. In Comparative Example 2, where component C was not used, the melt viscosity was higher and the hot-melt coating properties were inferior compared to Example 1. In Comparative Example 3, where the temperature during the mixing process 1 (C6-C8) was lower than the melting point of component B, mixing was insufficient, resulting in a lower elongation at the breaking point compared to Example 1. In Comparative Example 4, where component B was not used, the compression set at 70°C was inferior to that of Example 1. Although the components used in Comparative Examples 5 and 6, and Example 1, which used a batch mixer, were the same, the mixing (residence) times for Comparative Examples 5 and 6 were 5 minutes and 30 minutes, respectively, which were longer than the 71 seconds in Example 1. Furthermore, Comparative Example 4 showed inferior elongation at the breaking point, indicating that mixing was still insufficient with a mixing time of 5 minutes using a batch mixer. In Example 8, a manufacturing method was used in which 100 parts by mass of component a-1, which has a high weight-average molecular weight, was used, 250 parts by mass of component C was used as the raw material for the extruder, and an additional 150 parts by mass was added as a side feed. Compared with Comparative Example 7, in which 400 parts by mass of component C was used as the raw material for the extruder, Example 8 showed superior elongation at breaking and compression set at 70°C. [Industrial applicability]

[0115] The thermoplastic elastomer composition according to the manufacturing method of the present invention can be used in sealing gaskets, sheets, extruded films, tubes, etc., in the automotive, electrical and electronic products, packaging, and medical fields. The thermoplastic elastomer composition according to the manufacturing method of the present invention can be particularly suitable for use as a sealing material for covering service holes in automobile doors.

Claims

1. A method for producing a thermoplastic elastomer composition comprising the following components A to C and having a melt mass flow rate of 85 g / 10 min or more at 190°C and 21.2 N in an extruder capable of carrying out the following steps 1 and 2, comprising: step 1, kneading at least the following component A and the following component B at a temperature 10°C or more higher than the melting point of the following component B; and step 2, kneading the kneaded product obtained in step 1 with the following component C. Component A: Hydrogenated block copolymer containing polymer block a containing structural units derived from aromatic vinyl compounds and polymer block b containing structural units derived from conjugated diene compounds. Component B: Crystalline polyolefin resin Ingredient C: Softener

2. The manufacturing method according to claim 1, further comprising a pelletizing step of cutting the kneaded material obtained in step 2 into pellets to obtain pellets of the thermoplastic elastomer composition.

3. The manufacturing method according to claim 2, wherein the pelletizing step is a step of cutting the kneaded material with an underwater cutting type pelletizer.

4. The manufacturing method according to claim 1, wherein the elongation at the breaking point of the thermoplastic elastomer composition is 200% or more.

5. The manufacturing method according to claim 1, wherein the thermoplastic elastomer composition is a composition for forming a composite by heat-fusion bonding to a resin molded product, a rubber molded product, or a metal molded product.

6. A method for producing a composite, comprising the step of hot-melt coating a thermoplastic elastomer composition obtained by the manufacturing method described in any one of claims 1 to 5 onto a resin molded product, a rubber molded product, or a metal molded product.

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