JP2019178239A - Thermoplastic elastomer composition - Google Patents

Abstract

An object of the present invention is to provide a thermoplastic elastomer resin composition having excellent heat-fusibility with polyacetal (POM) and a composite molded article using the composition. A thermoplastic resin containing a controlled distribution type styrenic block copolymer A and a (meth) acrylic block copolymer B at a mass ratio (A / B) of 30/70 to 90/10. Elastomer composition. And a composite molded article in which the thermoplastic elastomer composition and polyacetal are thermally fused. [Selection diagram] None

Description

  The present invention relates to a thermoplastic elastomer composition used for various molded articles such as automobile parts, electrical / electronic equipment parts, medical equipment, building materials / pipe members, daily life / cosmetics, and a composite molded body using the composition. .

  A thermoplastic elastomer composition containing an acrylic elastomer and a styrene elastomer is proposed as a useful composition for various molded products such as automobile parts, electrical / electronic equipment parts, medical equipment, building materials / piping members, and daily life / cosmetics. Has been. The thermoplastic elastomer composition is required to have various physical properties depending on the use of the molded product. For example, in order to use it for grip rubber of game controllers and toothbrushes, not only good moldability but also heat fusion to polar resin such as polyacetal (POM) constituting the composite material body, and good tactile sensation High flexibility is required.

  In Patent Document 1, a controlled distribution type styrenic block copolymer is used as a flow modifier for improving the workability of a polymer compound. By increasing the blending ratio, the flowability is improved and easier. It is disclosed that high performance rubber compounds can be made that can be processed into

  Patent Document 2 discloses that a thermoplastic elastomer composition containing an acrylic resin and a softening agent in a hydrogenated styrene-based block copolymer has not only a heat fusion property with a polar resin such as an ABS resin, but also a flexibility. It is disclosed that it is excellent.

  Patent Document 3 discloses a resin composition containing an organic peroxide and carboxylated liquid polybutadiene in a hydrogenated styrene block copolymer, and a polyacetal resin adhesive obtained by adding a urethane thermoplastic elastomer and a petroleum resin. A thermoplastic resin composition is disclosed in Patent Document 4 that a thermoplastic polymer composition containing a styrene-based thermoplastic elastomer or an olefin-based thermoplastic elastomer and polyvinyl acetal is fused to polyacetal (POM). Has been.

JP 2007-84821 A JP 2001-81276 A JP 2010-1479 A International Publication No. 2009/081877

  However, Patent Document 1 discloses that a controlled distribution styrenic block copolymer is used as a flow modifier and can produce a high-performance rubber compound that can be easily processed. There is no description about wearability, and its performance is not clear.

  In Patent Document 2, the use of an acrylic resin or a hydrocarbon rubber softener for a styrene block copolymer that is not a controlled distribution type allows polar fusion, particularly for ABS, to have heat fusion properties. Although it is disclosed, the effect of heat fusion with polyacetal (POM) is not clear because there is no description.

  Moreover, although patent document 3 and 4 are evaluating the heat-fusibility with a polyacetal (POM) by the 180 degree | times peel test, higher adhesive force is desired.

  An object of the present invention is to provide a thermoplastic elastomer resin composition excellent in heat-fusibility with polyacetal (POM) and a composite molded body using the composition.

  As a result of various studies on the above problems by the present inventors, the control distribution type styrene-based block copolymer has heat-fusibility to a polar resin, and further, a (meth) acrylic block copolymer is used in combination. As a result, it was found that good heat-fusibility and moldability can be obtained with respect to polyacetal (POM), and the present invention has been completed.

The present invention
[1] Thermoplastic elastomer containing controlled distribution type styrene block copolymer A and (meth) acrylic block copolymer B in a mass ratio (A / B) of 30/70 to 90/10 The composition, and [2] relates to a composite molded body in which the thermoplastic elastomer composition according to [1] and polyacetal are heat-sealed.

  The thermoplastic elastomer resin composition of the present invention is effective in heat fusion with polyacetal (POM).

  The thermoplastic elastomer composition of the present invention has a controlled distribution type styrene block copolymer A and a (meth) acrylic block copolymer B, and has mechanical properties such as rigidity and toughness, wear resistance, and sliding properties. It is characterized by having heat-fusibility with respect to polyacetal (POM), which is known to be poor in adhesion and heat-fusibility while being excellent in mobility. “Heat fusion” refers to applying heat above the melting point to the thermoplastic elastomer composition, thermally fusing it to the adherend in a molten state, and solidifying it at a temperature below the melting point. A phenomenon that adheres to an interface of an object. In the present invention, a film having a peel strength measured by a test method described later of 30 N / 25 mm or more is “having heat-fusibility”.

  The content of the styrene monomer unit in the controlled distribution styrene block copolymer A is preferably 45% by mass or more, more preferably 50% by mass or more, from the viewpoint of heat-fusibility to a polar resin. Preferably, it is 55% by mass or more, and from the viewpoint of flexibility, it is preferably 80% by mass or less, more preferably 75% by mass or less, and further preferably 70% by mass or less. The content of the styrene monomer unit in the controlled distribution type styrene block copolymer A is the total amount of the styrene monomer unit in the hard segment and the styrene monomer unit in the soft segment. Further, when two or more kinds are used in combination as the control distribution type styrenic block copolymer A, the weighted average value of the content of the styrenic monomer in each block copolymer is calculated as the styrene-based single amount. The content of body units.

  In the present invention, the styrenic monomer includes not only styrene but also o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, etc. Also included are styrene derivatives substituted with ~ 4 alkyl groups.

  The controlled distribution type styrenic block copolymer A preferably has a hard segment and a soft segment from the viewpoint of flexibility and moldability. For example, a block unit (polymer unit of a styrene monomer as the hard segment ( Examples of the block copolymer Z include a block unit S) and a block unit (block unit B) which is a copolymer unit of a conjugated diene and a styrene monomer as a soft segment and has a control distribution structure.

  The mass ratio of the hard segment to the soft segment (hard segment / soft segment) in the controlled distribution type styrene block copolymer A is preferably 45/55 to 80/20, more preferably 50/50 to 65/35. .

  Examples of the conjugated diene include butadiene, isoprene, 1,3-pentadiene and the like.

  The block copolymer Z preferably has a [block unit S-block unit B] m-block unit S-type structure. Here, m is preferably 1 to 5, but in the present invention, a triblock copolymer in which m is 1 is preferable.

  Block unit B has two or more regions containing conjugated diene units as main constituent units and one or more regions containing styrene monomer units as main constituent units, and both ends adjacent to block unit S. Is preferably a region containing a conjugated diene unit as a main constituent unit.

In the block copolymer Z, it is preferable that part or all of the unsaturated bond of the conjugated diene monomer unit is hydrogenated. By hydrogenating the unsaturated bond of the conjugated diene monomer unit, the unsaturated bond is reduced, and the heat resistance, weather resistance and mechanical properties are improved. The hydrogenation rate is preferably 80% or more, and more preferably 90% or more. In the present invention, the hydrogenation rate is determined by measuring the content of carbon-carbon double bonds derived from the conjugated diene monomer in the thermoplastic styrene elastomer A by ¹ H-NMR spectrum before and after hydrogenation. , From the measured value.

  The hydrogenated product of the block copolymer Z having a triblock structure in which the conjugated diene is butadiene is called a control distribution SEBS. Examples of commercially available products of the control distribution SEBS include A series manufactured by Kraton Polymer Co., Ltd. MD series etc. are mentioned.

  The control distribution type styrene block copolymer is well known in the technical field, and is described in, for example, JP-A 2007-84821, JP-T 2013-518170, and the like.

  The weight average molecular weight of the controlled distribution type styrenic block copolymer A is preferably 100,000 or more, more preferably 200,000 or more from the viewpoint of heat-fusibility to a polar resin, and preferably 500,000 from the viewpoint of moldability. Below, more preferably 450,000 or less, and still more preferably 350,000 or less. When two or more types are used in combination as the control distribution type styrene block copolymer A, the weighted average molecular weight of each styrene lock copolymer is defined as the weight average molecular weight.

  Examples of the (meth) acrylic monomer constituting the (meth) acrylic block copolymer B include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic. Acid butyl, phenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (meth ) Glycidyl acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. In the present specification, unless otherwise specified, an alkyl group name without a subscript includes isomers such as n-, iso-, sec-, tert-, etc. And both acrylic.

  The amount of the (meth) acrylic monomer is preferably 20% by mass or more, more preferably 50% by mass or more, and more preferably 80% by mass or more in the monomer constituting the (meth) acrylic block copolymer B. preferable.

  Other monomers that can be copolymerized include vinyl monomers such as styrene, α-methylstyrene, vinyl acetate, ethylene, propylene, butadiene, isoprene, and maleic anhydride. Among these, styrene, α-Methylstyrene and ethylene are preferable, and these monomers are used in combination within a range not to impair the object of the present invention (preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less). May be.

  Examples of the monomer polymerization method for obtaining the (meth) acrylic block copolymer B include a radical polymerization method, a living anion polymerization method, and a living radical polymerization method. Examples of the polymerization form include a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, and a bulk polymerization method.

  The (meth) acrylic block copolymer B is preferably a block copolymer having two or more blocks constituting a hard segment and one or more blocks constituting a soft segment, and a block constituting a soft segment A triblock copolymer having two blocks constituting a hard segment on one side is more preferable. The proportion of the triblock copolymer is preferably 60% by mass or more, and more preferably 70% by mass or more in the (meth) acrylic block copolymer B. Further, the (meth) acrylic block copolymer B may contain a diblock copolymer and a multiblock copolymer in addition to the triblock copolymer.

  The monomer constituting the hard segment is preferably one or more methacrylic monomers. Such methacrylic acid monomers include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, cyclohexyl methacrylate, phenyl methacrylate, methacrylic acid. Examples include hydroxyethyl acid, glycidyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, phenoxyethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, and the like. More preferred is methyl methacrylate.

  The monomer constituting the hard segment preferably contains the methacrylic monomer, but does not impair the object of the present invention (preferably 30% by mass or less, more preferably 20% by mass or less, More preferably, it is 10% by mass or less) and may contain an acrylic monomer or another monomer. Moreover, it can also be set as a hard segment by high molecular weight by a polymerization reaction.

  Examples of the copolymerizable monomer include ethylene, propylene, α-olefin, styrene, α-methylstyrene, acrylonitrile, parahydroxystyrene, vinyl alcohol, acrylic acid, methacrylic acid, acrylamide, methacrylamide, methyl vinyl ether, Examples thereof include vinyl monomers such as vinyl benzoate, maleic acid, and N-cyclohexylmaleimide. Among these, styrene, α-methylstyrene, and ethylene are preferable.

  In order for the (meth) acrylic block copolymer B to exhibit characteristics as a thermoplastic elastomer, it is preferable to have a hard segment having a glass transition temperature of room temperature or higher.

  The glass transition temperature of the block constituting the hard segment is preferably 20 to 200 ° C, more preferably 30 to 180 ° C, and even more preferably 50 to 150 ° C from the viewpoint of maintaining toughness in the normal temperature range of the composition. If the glass transition temperature of the block constituting the hard segment is too low, the resulting composition may have insufficient heat resistance, and it is difficult to obtain raw materials for blocks having a glass transition temperature exceeding 200 ° C.

  The vinyl monomer constituting the soft segment is preferably one or more of acrylic monomers. As such an acrylic monomer, ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, benzyl acrylate, phenylethyl acrylate and the like are preferable because of high reactivity with the transesterification catalyst.

  The glass transition temperature of the block constituting the soft segment is preferably −100 to 19 ° C., more preferably −80 to 10 ° C., and further preferably −70 to 0 ° C. If the glass transition temperature of the block constituting the soft segment is too high, the resulting composition may be insufficient in flexibility, and it is difficult to obtain raw materials for blocks having a glass transition temperature lower than −100 ° C.

  Acrylic monomers composing soft segments with a glass transition temperature of 19 ° C or lower include n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, n-hexyl acrylate, ethyl hexyl acrylate, acrylic acid At least one selected from the group consisting of n-heptyl, n-octyl acrylate, and phenylethyl acrylate is preferred, and it is difficult to be compatible with the hard segment, so that a phase-separated structure is easily obtained. At least one selected from the group consisting of propyl, n-butyl acrylate, n-hexyl acrylate, n-heptyl acrylate and n-octyl acrylate is more preferable, and n-butyl acrylate is more preferable.

  The monomer constituting the soft segment preferably contains the acrylic monomer, but does not impair the purpose of the present invention (preferably 30% by mass or less, more preferably 20% by mass or less, More preferably, it is 10% by mass or less) and may contain a methacrylic monomer or another monomer.

  As a method for measuring the glass transition temperature of a polymer, differential scanning calorimetry (DSC), dynamic viscoelasticity measurement, thermal expansion measurement (TMA), etc. are known. In the present invention, a hard segment and a soft segment are used. In block copolymers containing both, dynamic viscoelasticity measurement is a common method that can accurately measure both hard segment and soft segment values. A method for determining the glass transition temperature from the peak of the dielectric loss tangent Tan δ is known. Therefore, the glass transition temperature measured by dynamic viscoelasticity measurement is used for the glass transition temperature of the hard segment and the soft segment in the present invention.

  The mass ratio of the hard segment to the soft segment (hard segment / soft segment) in the (meth) acrylic block copolymer B is preferably 10/90 to 70/30 from the viewpoint of imparting appropriate flexibility, 85-60 / 40 is more preferable.

  Examples of commercially available products that can be used as the (meth) acrylic block copolymer B include Clarity manufactured by Kuraray Co., Ltd. and Nano Strength manufactured by Arkema Co., Ltd.

  The weight average molecular weight of the (meth) acrylic block copolymer B is preferably 20,000 or more, more preferably 30,000 or more, and further preferably 40,000 or more, from the viewpoint of mechanical properties such as tensile strength. Further, from the viewpoint of easy handling and maintaining a melt viscosity suitable for production of a molded article such as injection molding, 500,000 or less is preferable, 400,000 or less is more preferable, and 200,000 or less is more preferable. From these viewpoints, the weight average molecular weight of Component A is preferably 20,000 to 500,000, more preferably 30,000 to 400,000, and further preferably 40,000 to 200,000.

Moreover, in the relationship between a weight average molecular weight (Mw) and a number average molecular weight (Mn), it is Mw / Mn,
1-5 are preferable and 1.05-3 are more preferable.

  The A hardness of the (meth) acrylic block copolymer B is preferably 20 to 80, more preferably 25 to 70, and further preferably 30 to 67 from the viewpoint of the flexibility of the composition.

  In the thermoplastic elastomer composition of the present invention, when the content of the (meth) acrylic block copolymer B exceeds a certain amount, the releasability is deteriorated. From this viewpoint, the mass ratio (A / B) of the controlled distribution type styrene block copolymer A and the (meth) acrylic block copolymer B in the thermoplastic elastomer composition of the present invention is 30/70 to 90 / 10, preferably 35/65 to 85/15, more preferably 40/60 to 80/20.

  The total content of the controlled distribution type styrene block copolymer A and the (meth) acrylic block copolymer B is preferably 70% by mass or more, more preferably 80% by mass or more in the thermoplastic elastomer composition. Preferably, it is 99.8 mass% or less, More preferably, it is 90 mass% or less.

  The thermoplastic elastomer composition of the present invention preferably further contains a plasticizer C from the viewpoints of flexibility and heat-fusibility.

  The plasticizer C is preferably at least one selected from the group consisting of paraffin oil, naphthenic oil, and aromatic oil, and among these, the affinity for the control distribution type styrene block copolymer A is high. Paraffin oil is more preferable from the viewpoint of being good and being less likely to bleed.

The higher the kinematic viscosity of the plasticizer C at 40 ° C., the more it prevents volatilization at the time of heating and melting, and the bleed resistance is improved, so that it is preferably 50 mm ² / s or more, more preferably 60 mm ² / s or more, More preferably, it is 80 mm ² / s or more, and from the viewpoint of improving heat-fusibility to a polar resin, more preferably 150 mm ² / s or more, and since the lower one is easier to handle, preferably 500 mm ² / s or less, more preferably 450 mm ² / s or less, and still more preferably 400 mm ² / s or less.

  The content of the plasticizer C is preferably 1 part by mass or more from the viewpoint of flexibility, with respect to the total amount of 100 parts by mass of the controlled distribution styrene block copolymer A and the acrylic block copolymer B. The amount is preferably 10 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less, from the viewpoint of preventing oil bleed and heat fusion to a polar resin.

  Moreover, content of the plasticizer C in a thermoplastic elastomer composition becomes like this. Preferably it is 5-45 mass%, More preferably, it is 10-40 mass%.

  The thermoplastic elastomer composition of the present invention may contain an elastomer other than the controlled distribution type styrene block copolymer A and the (meth) acrylic block copolymer B. As long as the effect of the invention is not impaired, reinforcing agents such as carbon black, silica, carbon fiber, glass fiber, inorganic filler, insulating heat conductive filler, pigment, hydrated metal compound, red phosphorus, ammonium polyphosphate, antimony , Flame retardants such as silicone, antistatic agents, thickeners, tackifiers, crosslinking agents, crosslinking aids, thermal stabilizers, antioxidants, light stabilizers, UV absorbers, antiblocking agents, sealability improvers Further, various additives such as a release agent, a colorant, and a fragrance may be contained.

  The thermoplastic elastomer composition of the present invention is prepared by mixing raw materials including a control distribution type styrene block copolymer A and a (meth) acrylic block copolymer B, and further a plasticizer C as required. Obtained by solidification.

  “Mixing” as used in the present invention is not particularly limited as long as various components are mixed well, and various components may be dissolved and mixed in a soluble organic solvent, or by melt kneading. Although mixing may be performed, mixing of the raw materials is preferably performed under conditions where the raw materials are melted, preferably under conditions where the (meth) acrylic block copolymer B is melted.

  When melt-kneading, a general extruder can be used, and it is preferable to use a twin-screw extruder for improving the kneading state. Supply to the extruder may be made by mixing various components in advance using a mixing device such as a Henschel mixer from one hopper, or each component is charged into two hoppers and fixed with a screw under the hopper. You may offer while.

  The product obtained by mixing the raw materials constituting the thermoplastic elastomer composition can be in the form of pellets, sheets, etc., depending on the application. For example, it is melt-kneaded by an extruder, extruded into a strand, and cut into pellets such as a cylindrical shape or a rice grain by a cutter while cooling in cold water. The obtained pellet is usually formed into a predetermined sheet-like molded product or molded product by injection molding or extrusion molding. Further, the melt-kneaded product can be formed into pellets with a ruder or the like and used as a forming raw material.

  The A hardness of the thermoplastic elastomer composition of the present invention is preferably 90 or less, more preferably 85 or less, and still more preferably 80 or less, from the viewpoint of flexibility, and preferably from the viewpoint of stickiness suppression and practicality. Is 40 or more, more preferably 50 or more, and still more preferably 55 or more.

  A molded body can be obtained by appropriately heat-molding the thermoplastic elastomer composition of the present invention according to a conventional method. The use of the molded product obtained by thermoforming the thermoplastic elastomer composition of the present invention is not particularly limited, and fields in which general styrene elastomers, (meth) acrylic elastomers, polyolefin elastomers, and the like are used. Can be used.

  The apparatus used for manufacturing a molded body using the thermoplastic elastomer composition of the present invention can be any molding machine capable of melting a molding material. For example, an extrusion molding machine, an injection molding machine, a press molding machine, a blow molding machine, a mixing roll, etc. are mentioned.

  Since the thermoplastic elastomer composition of the present invention is fused to various materials, it can be suitably used for bonding members made of different materials. For example, it is used for fusing to at least one member selected from the group consisting of metal, ceramic, glass, and polar resin, and particularly exhibits good heat-fusibility with respect to polar resin and the like.

  The metal is not particularly limited, and examples thereof include aluminum, aluminum alloy, stainless steel, iron, copper, galvanized steel, magnesium, magnesium alloy, and various plated products.

  Examples of polar resins include polyester resins such as polyacetal and polybutylene terephthalate, poly (meth) acrylate resins such as polycarbonate and polymethyl methacrylate, polyethylene oxide resins, polypropylene oxide resins, polyvinyl acetate resins, and polyamides. Resin, polyurethane resin, polystyrene resin such as ABS resin, polyvinyl ether resin, polyvinyl alcohol resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyetherimide resin, polyether ketone resin, polyether ether Examples include ketone resins, LCP (liquid crystal polymer), polar resins such as ionomers, and mixtures of two or more thereof. Among these, heat fusion with polyacetal, which has heretofore been difficult to heat-fuse, is excellent.

  As a means for applying heat to heat-seal the thermoplastic elastomer, a hot press machine, a heated roll machine, a hot air generator, heated steam, an ultrasonic welder, a high frequency welder, a laser, or the like can be used.

  Therefore, the thermoplastic elastomer composition of the present invention can be integrated with the metal, ceramic, glass, polar resin and other members to form a composite molded body. Even if the interface of the fusion part is a complicated three-dimensional shape by heat fusion, it can be well integrated and integrated into a complicated three-dimensional shape, and members with complicated joint surfaces and joint surfaces of different shapes It is also possible to combine the members having

  The composite molded body in which the thermoplastic elastomer composition of the present invention is heat-sealed to a member includes injection molding, injection compression molding, insert molding, multicolor molding, vacuum molding, pressure molding, blow molding, hot press molding, foam molding, The thermoplastic elastomer composition of the present invention is not self-adhesive like an adhesive and is easy to handle, although it can be obtained by molding by a method such as laser fusion molding or extrusion molding. Therefore, it can be applied to injection molding.

  The composite molded body in which the thermoplastic elastomer composition of the present invention is thermally fused to a member includes an insert molded body in which a polar resin is inserted into a molded body made of the thermoplastic elastomer composition, the thermoplastic elastomer composition, and the polar resin. And a composite molded body obtained by multicolor molding.

  The thermoplastic elastomer composition of the present invention can be used as various molded products depending on applications, but since it has excellent heat-fusibility of polar resins such as polyacetal and has good flexibility, It can be suitably used for a grip rubber of a toothbrush.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Various physical properties of the raw materials used in Examples and Comparative Examples were measured by the following methods.

<Component A (controlled distribution type styrene block copolymer, etc.)>
[Content of styrene monomer unit]
Proton NMR measurement is performed with a nuclear magnetic resonance apparatus (manufactured by BRUKER, Germany, DPX-400), and the content of styrene and / or styrene derivative is determined by quantifying the characteristic group of styrene. The content of other monomer units can also be determined by proton NMR measurement.

[Hard segment / Soft segment (mass ratio)]
The mass ratio of the hard segment to the soft segment was measured by proton NMR measurement at 25 ° C in a 3-5 vol% concentration in deuterated chloroform solvent using a nuclear magnetic resonance apparatus (manufactured by BRUKER, Germany, DPX-400). It calculates from the signal intensity ratio of the methylene peak adjacent to various oxygen in the structure.

[Weight average molecular weight (Mw)]
Under the following measurement conditions, the molecular weight is measured in terms of polystyrene by gel permeation chromatography, and the weight average molecular weight is determined.

Measuring device / pump: JASCO (JASCO Corporation), PU-980
・ Column oven: Showa Denko KK, AO-50
・ Detector: Hitachi, RI (differential refractometer) detector L-3300
・ Column type: Showa Denko Co., Ltd. “K-805L (8.0 × 300mm)” and “K-804L (8.0 × 300mm)” each used in series ・ Column temperature: 40 ℃
・ Guard column: KG (4.6 × 10mm)
・ Eluent: Chloroform ・ Eluent flow rate: 1.0 ml / min
・ Sample concentration: about 1mg / ml
・ Sample solution filtration: 0.45μm pore size disposable filter made of polytetrafluoroethylene ・ Standard sample for calibration curve: Polystyrene made by Showa Denko K.K.

<Component B ((meth) acrylic block copolymer, etc.)>
[Hard segment / Soft segment (mass ratio)]
The composition ratio (mass ratio) of each polymer block in the (meth) acrylic block copolymer is determined by ¹ H-NMR ( ¹ H-nuclear magnetic resonance) measurement.
・ Device: Nuclear magnetic resonance device “AVANCE III” manufactured by BRUKER
・ Deuterated solvent: Deuterated chloroform

[A hardness]
Measure with JIS K 6253 Type A.

[Melting point]
Using a differential scanning calorimetry (DSC) apparatus, the melting peak temperature obtained by raising the temperature at 10 ° C./min according to the method specified in JIS K 7121 is defined as the melting point. When a plurality of melting peaks appear, the melting peak appearing at a lower temperature is taken as the melting point.

[Glass transition temperature (Tg)]
Using a dynamic viscoelasticity measuring device (RSAIII manufactured by TA Instruments Co., Ltd.), heat the test piece under the conditions of -100 to 280 ° C, temperature rise rate of 5 ° C / min, frequency 10Hz. The peak temperature of the loss tangent (Tan δ) observed at this time is defined as the glass transition temperature (Tg). A test piece having a thickness of 2 mm, a width of 12 mm, and a length of 30 mm is used.
In an elastomer having a plurality of blocks (soft segment and hard segment), a plurality of loss tangent peaks are usually observed. In this case, the peak on the low temperature side is derived from the soft segment, and the peak on the high temperature side is It comes from the hard segment.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
From a gel permeation chromatograph (GPC), the following apparatus, column and solvent are used and determined from polystyrene conversion.
・ Equipment: Tosoh HLC-8120
・ Column: Inertsil WF300
・ Solvent: Tetrahydrofuran

<Component C (plasticizer)>
(Kinematic viscosity)
Measured at a temperature of 40 ° C. according to JIS Z 8803.

Examples 1-8 and Comparative Examples 1-8
(1) Production of Thermoplastic Elastomer Composition (Pellets) The materials shown in Tables 5 and 6 other than Component C were dry blended and impregnated with Component C to prepare a mixture. Thereafter, the mixture was melt-kneaded with an extruder under the following conditions, extruded into strands, cooled to about 3 mm in diameter and about 3 mm in thickness with a cutter while cooled in cold water, and pellets of the thermoplastic elastomer composition were formed. Manufactured.

[Melting and kneading conditions]
Extruder: KZW32TW-60MG-NH (trade name, manufactured by Technobel Co., Ltd.)
Cylinder temperature: 180 ~ 220 ℃
Screw rotation speed: 300r / min

  The details of the raw materials described in Tables 5 and 6 used in Examples and Comparative Examples are as follows.

(2) Production of molded body of thermoplastic elastomer composition The pellets were injection molded under the following conditions to produce a plate 2 mm thick x 125 mm wide x 125 mm long.

[Injection conditions]
Injection molding machine: 100MSIII-10E (trade name, manufactured by Mitsubishi Heavy Industries, Ltd.)
Injection molding temperature: 200 ℃
Injection pressure: 30%
Injection time: 3sec
Mold temperature: 40 ℃

  In addition, injection moldability was evaluated from the state of the obtained plate, etc., and further, flexibility and heat fusibility were evaluated. The results are shown in Tables 5 and 6.

[Evaluation criteria for injection moldability]
○: The plate is in good condition ×: The plate can be molded but bleed out occurs from the plate XX: The plate can be molded, but the releasability is poor XX: The plate cannot be molded, or Bad condition

[Flexibility]
A durometer A hardness was measured in accordance with the method specified in JIS K 6253 using a plate (125 mm square plate) that has passed one day after injection molding, and the flexibility was evaluated according to the following evaluation criteria.
<Evaluation criteria>
A hardness: ◎: 55 or more and 80 or less ○: Over 80 and 90 or less △: Less than 55 or more than 90

[Heat fusion]
The following polar resin is inserted into a 4 mm thick x 25 mm wide x 125 mm long mold, and the thermoplastic elastomer compositions obtained in the examples and comparative examples are injection molded under the following conditions to produce a strip-shaped melt. A wearing test piece was prepared.

<Insert material (polar resin)>
(1) Size: 2mm thick x 25mm wide x 120mm long
(2) Type / Polyacetal (POM): Duracon M90-44 (manufactured by Polyplastics)
Polycarbonate (PC): Iupilon H-3000, manufactured by Mitsubishi Engineering Plastics

<Injection molding conditions>
Injection molding machine: 100MSIII-10E, manufactured by Mitsubishi Heavy Industries, Ltd.
Injection molding temperature: 260 ° C (POM) or 240 ° C (PC)
Injection pressure: 98MPa, injection speed: 50%, holding pressure: 20%, holding time: 10sec
Injection time: 2sec
Mold temperature: 40 ℃

  Using the obtained fusion test piece, the peel strength was measured at an ambient temperature of 23 ° C. according to JIS K6854-2 “Test method for adhesive peel strength (180 degree peel)”. Using a thermoplastic elastomer layer as a flexible adherent and a polar resin layer as a rigid adherend, the elastomer layer is subjected to a tensile test in the direction of 180 ° at 50 mm / min. The peel strength between the skin layer and the base material layer (unit: N / 25 mm) was measured, and the heat-fusibility was evaluated according to the following evaluation criteria.

<Evaluation criteria>
Peel strength: ○: 30N / 25mm or more ×: Less than 30N / 25mm

  From the above results, the thermoplastic elastomer compositions of Examples 1 to 8 have good flexibility and excellent moldability as compared with the thermoplastic elastomer compositions of Comparative Examples 1, 2, and 5. I understand. Moreover, it turns out that it is excellent in the heat-fusion property with respect to a polyacetal compared with the thermoplastic elastomer composition of the comparative examples 6, 7, and 8. Moreover, it turns out that the thermoplastic-elastomer composition of Example 4 which mix | blended high-viscosity paraffin oil among the Examples is excellent in heat-fusibility with a polyacetal.

  The thermoplastic elastomer composition of the present invention is useful for various molded products such as automobile parts, electrical / electronic equipment parts, medical equipment, building materials / piping members, daily life / cosmetics, and further grips, tubes, packings, gaskets. It is used for various members such as cushion bodies, films and sheets.

Claims (10)

  A thermoplastic elastomer composition comprising a controlled distribution type styrene block copolymer A and a (meth) acrylic block copolymer B in a mass ratio (A / B) of 30/70 to 90/10.   Furthermore, 1-50 mass parts of plasticizers C are contained with respect to 100 mass parts of total amounts of the control distribution type styrene block copolymer A and the (meth) acrylic block copolymer B. A thermoplastic elastomer composition.   The thermoplastic elastomer composition according to claim 2, wherein the plasticizer C is at least one selected from the group consisting of paraffin oil, naphthenic oil, and aromatic oil. The thermoplastic elastomer composition according to claim 2 or 3, wherein the plasticizer C has a kinematic viscosity at 40 ° C of 50 to 400 mm ² / s.   The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the weight average molecular weight of the controlled distribution type styrenic block copolymer A is 100,000 to 500,000.   The (meth) acrylic block copolymer B is a block copolymer having two or more blocks constituting a hard segment and one or more blocks constituting a soft segment. Thermoplastic elastomer composition.   The glass transition temperature of the block constituting the hard segment of the (meth) acrylic block copolymer B is 20 to 200 ° C, and the glass transition temperature of the block constituting the soft segment is -100 to 19 ° C. 7. The thermoplastic elastomer composition according to 6.   The thermoplastic elastomer composition according to any one of claims 1 to 7, wherein the (meth) acrylic block copolymer B has a weight average molecular weight of 20,000 to 500,000.   The thermoplastic elastomer composition according to any one of claims 1 to 8, wherein the thermoplastic elastomer composition is used for heat-sealing with polyacetal.   A composite molded body in which the thermoplastic elastomer composition according to claim 1 and polyacetal are heat-sealed.