WO2018230614A1

WO2018230614A1 - Thermoplastic elastomer composition

Info

Publication number: WO2018230614A1
Application number: PCT/JP2018/022616
Authority: WO
Inventors: 亘佑中村; 雄志熊谷; 勝長谷川
Original assignee: デンカ株式会社
Priority date: 2017-06-13
Filing date: 2018-06-13
Publication date: 2018-12-20
Also published as: JP2020128447A

Abstract

[Problem] To provide: a thermoplastic elastomer composition which has excellent transparency, flexibility, low-temperature characteristics, tensile characteristics and blocking resistance; and a molded body, a sheet and a tube for medical use, each of which uses this thermoplastic elastomer composition. [Solution] A thermoplastic elastomer composition which is obtained by blending 3-10 parts by mass of (B) an acetylated monoglyceride-based plasticizer per 100 parts by mass of (A) a cross-copolymer which comprises a main chain of an olefin-aromatic vinyl compound copolymer containing 10-23% by mole of an aromatic vinyl compound monomer unit and 0.01-0.5% by mole of an aromatic polyene monomer unit, with the balance made up of an olefin monomer unit, and a cross chain of an aromatic vinyl compound polymer that is formed from an aromatic vinyl compound monomer unit.

Description

Thermoplastic elastomer composition

The present invention relates to a thermoplastic elastomer composition excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance, and a molded body, a sheet, and a medical tube using the same.

In recent years, thermoplastic elastomers having excellent productivity have been increasingly used for applications such as automobile parts, home appliance parts, medical parts or sundries, where vulcanized rubber has been the mainstream. Among them, many new thermoplastic elastomers having required characteristics according to various uses have been proposed. For example, in Patent Documents 1 and 2, a so-called styrene-ethylene copolymer is obtained by a method in which a small amount of divinylbenzene is copolymerized and a polystyrene chain (cross chain) is introduced via a vinyl group of a divinylbenzene unit. Cross copolymers have been proposed. The cross-copolymer obtained by this method is a block copolymer having a branched structure having a styrene-ethylene copolymer chain as a soft segment and polystyrene as a hard segment, and is extremely excellent in scratch resistance and molding processability. It has become a material.

The cross-copolymer is a thermoplastic elastomer that has extremely excellent properties such as scratch resistance, softness, transparency, and moldability, but depending on the application, curing at low temperatures is an issue, and excellent low-temperature softness, etc. It was necessary to use a processing technique such as blending with a resin, elastomer, rubber, additive, etc. having the above characteristics. In addition, in medical tube applications, low temperature characteristics may be required because it may be connected to an infusion pump used at low temperatures. In addition, in medical tube applications, blocking resistance at high temperatures may be required because heating is performed during sterilization. Transparency decreases when pursuing low-temperature properties and blocking resistance with a cross-copolymer alone. There was a problem to do.

For example, in medical tubes that are medical parts, in addition to softness, transparency, and bending resistance (kink resistance), there is little drug absorption and absorption, and drug quantification that can be transported quantitatively and resistance to infusion pump circuits. Various properties are required such as ironing ability (shape recovery, wear resistance, etc.) and excellent radiation resistance against gamma rays and electron beams for sterilization. In response to these requirements, in Patent Document 3, the surface is cross-linked by electron beam irradiation after tube forming, so that the softness, transparency, low absorption and absorption of drugs, pump circuit suitability, chemical stability, It has been proposed to provide a medical tube having excellent kink resistance, heat resistance corresponding to various sterilization methods while suppressing blocking. In Patent Document 4, a support layer occupying 50% or more of the tube thickness is a cross-copolymer having sufficient softness, and an inner layer is a multi-layer tube having a small blocking property. It is proposed to improve the blockage caused by the close contact between the inner walls when clamped with a. In recent years, the dissemination of medical parts has been promoted, and in many cases it is incinerated after use to prevent biohazards, and it is important to use non-soft PVC material that does not generate chlorine compounds as gas during incineration. It has become.

JP 2009-102515 A International Publication No. 2007/139116 JP 2013-202133 A International Publication No. 2013/137326

An object of the present invention is to provide a thermoplastic elastomer composition excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance, and a molded article, a sheet, and a medical tube using the same.

The gist of the present invention is as follows.
[1] Olefin-aromatic vinyl compound system in which aromatic vinyl compound monomer unit is 10 to 23 mol%, aromatic polyene monomer unit is 0.01 to 0.5 mol%, and the balance is an olefin monomer unit. The acetylated monoglyceride plasticizer (B) is used for 100 parts by mass of the cross-copolymer (A) containing the main chain of the copolymer and the cross-chain of the aromatic vinyl compound polymer comprising the aromatic vinyl compound monomer unit. ) A thermoplastic elastomer composition comprising 3 to 10 parts by mass.

[2] The cross copolymer (A) contains 70 to 95% by mass of an olefin-aromatic vinyl compound copolymer and 5 to 30% by mass of an aromatic vinyl compound polymer. Thermoplastic elastomer composition.

[3] The thermoplastic elastomer composition according to any one of [1] or [2], wherein the aromatic vinyl compound monomer unit is styrene.

[4] The thermoplastic elastomer composition according to any one of [2] to [3], wherein the olefin monomer unit is ethylene.

[5] The thermoplastic elastomer composition according to any one of [1] to [4], wherein the aromatic polyene monomer unit is divinylbenzene.

[6] The thermoplastic elastomer composition according to any one of [1] to [5], wherein the acetylated monoglyceride plasticizer (B) is substantially acetylated monolauryl glyceride.

[7] The cross copolymer (A) has a structure in which an ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and an aromatic vinyl compound polymer chain are bonded via an aromatic polyene monomer unit. The thermoplastic elastomer composition according to [1], which is a copolymer satisfying all of the following conditions (1) to (3):
(1) The content of the aromatic vinyl compound monomer unit in the ethylene-aromatic vinyl compound-aromatic polyene copolymer is 10 to 23 mol%, and the content of the aromatic polyene monomer unit is 0.01 mol% or more. 0.5 mol% or less, and the balance is the content of ethylene monomer units.
(2) The ethylene-aromatic vinyl compound-aromatic polyene copolymer has a weight average molecular weight of 50,000 to 300,000 and a molecular weight distribution (Mw / Mn) of 1.8 to 6.
(3) The content of the ethylene-aromatic vinyl compound-aromatic polyene copolymer contained in the cross copolymer is in the range of 70 to 95% by mass.

[8] A thermoplastic elastomer composition comprising 3 to 10 parts by mass of an acetylated monoglyceride plasticizer (B) per 100 parts by mass of a cross copolymer (A), the cross copolymer (A ) Satisfies all the following conditions (4) to (7).
(4) By ¹ H-NMR measurement, peaks attributed to the ethylene-aromatic vinyl compound copolymer and aromatic vinyl compound polymer were observed, and the aromatic vinyl compound in the ethylene-aromatic vinyl compound copolymer was observed. The content is 10 to 23 mol%, and the content of the ethylene-aromatic vinyl copolymer component contained is in the range of 70 to 95% by mass,
(5) The ethylene-aromatic vinyl compound copolymer and aromatic vinyl compound polymer contained have a bond,
(6) MFR (200 ° C., weight 49 N) is in the range of 0.05 to 50 g / 10 minutes,
(7) The gel content is 0.2% by mass or less.

[9] A molded body using the thermoplastic elastomer composition according to any one of [1] to [8].

[10] The molded article according to [9], which is a sheet.

[11] The molded article according to [9], which is a medical tube.

According to the present invention, it is possible to provide a thermoplastic elastomer composition that is excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance, and a molded article, sheet, and medical tube using the same.

Hereinafter, the thermoplastic elastomer composition of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within a range that does not impair the effects of the present invention.
[Thermoplastic elastomer composition]
The present invention relates to aromatic vinyl compound monomer units of 10 to 23 mol%, aromatic polyene monomer units of 0.01 to 0.5 mol%, preferably 0.01 to 0.2 mol%, and the balance being olefin. A cross copolymer (A) 100 comprising a main chain of an olefin-aromatic vinyl compound copolymer as a monomer unit and a cross chain of an aromatic vinyl compound polymer comprising an aromatic vinyl compound monomer unit. A thermoplastic elastomer composition comprising 3 to 10 parts by mass of an acetylated monoglyceride plasticizer (B) per part by mass.

In the present specification and claims, the description “A to B” means not less than A and not more than B.

(Cross copolymer (A))
In one embodiment of the present invention, the cross copolymer (A) is an olefin-aromatic vinyl compound copolymer comprising an aromatic vinyl compound monomer unit, an olefin monomer unit, and an aromatic polyene monomer unit. A main chain of a polymer (olefin-aromatic vinyl compound-aromatic polyene copolymer) and a cross chain of a polymer (aromatic vinyl compound polymer) comprising an aromatic vinyl compound monomer unit, The polymer which consists of an aromatic vinyl compound monomer unit has the structure couple | bonded through the aromatic polyene monomer unit of the principal chain.

Examples of the aromatic vinyl compound monomer unit include styrene and various substituted styrenes such as p-methylstyrene, m-methylstyrene, o-methylstyrene, ot-butylstyrene, mt-butylstyrene, p- Examples thereof include units derived from styrene monomers such as t-butylstyrene, p-chlorostyrene and o-chlorostyrene. Among these, a styrene unit, a p-methylstyrene unit, and a p-chlorostyrene unit are preferable, and a styrene unit is particularly preferable. One type of these aromatic vinyl compound monomer units may be used, or two or more types may be used in combination.

Examples of olefin monomer units include ethylene and α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, vinylcyclohexane, cyclic olefins, Examples thereof include units derived from each α-olefin monomer and cyclic olefin monomer such as cyclopentene and norbornene. Preferably, a mixture of an ethylene unit, a propylene unit, a 1-butene unit, a 1-hexene unit, a 1-octene unit or the like is used, and an ethylene unit is particularly preferably used.

The aromatic polyene monomer unit is an aromatic polyene having 10 to 30 carbon atoms and having a plurality of double bonds (vinyl group) and one or more aromatic groups, such as o- Divinylbenzene, p-divinylbenzene, m-divinylbenzene, 1,4-divinylnaphthalene, 3,4-divinylnaphthalene, 2,6-divinylnaphthalene, 1,2-divinyl-3,4-dimethylbenzene, 1,3 -Units derived from an aromatic polyene monomer such as divinyl-4,5,8-tributylnaphthalene, preferably any one or two of orthodivinylbenzene unit, paradivinylbenzene unit and metadivinylbenzene unit A mixture of seeds or more is preferably used.

The content of each structural unit in the olefin-aromatic vinyl compound-based copolymer is 10 to 23 mol% of the aromatic vinyl compound monomer unit from the viewpoint of flexibility and transparency, and the aromatic polyene monomer unit. 0.01 to 0.5 mol%, the balance being olefin monomer units, and from the viewpoints of softness and blocking resistance as a thermoplastic elastomer composition, preferably aromatic vinyl compound monomer units 12 ˜18 mol%, aromatic polyene monomer units 0.01 to 0.2 mol%, and the balance is olefin monomer units.

The content ratio of the olefin-aromatic vinyl compound copolymer and the polymer comprising the aromatic vinyl compound monomer unit is preferably an olefin-aromatic vinyl compound copolymer from the viewpoint of transparency and flexibility. Is from 70 to 95% by weight, and the polymer comprising aromatic vinyl compound monomer units is from 5 to 30% by weight. From the viewpoint of physical properties as a thermoplastic elastomer composition, olefin-aromatic vinyl is particularly preferable. The compound-based copolymer is 82 to 92% by mass, and the polymer composed of aromatic vinyl compound monomer units is 8 to 18% by mass.

The fact that the olefin-aromatic vinyl compound-aromatic polyene copolymer chain and the aromatic vinyl compound polymer chain are bonded via the aromatic polyene monomer unit can be proved by the following observable phenomenon. In the following description, an example in which the most preferable ethylene-aromatic vinyl compound (styrene) -aromatic polyene (divinylbenzene) copolymer chain and aromatic vinyl compound (polystyrene) chain are bonded via a divinylbenzene unit will be described. Show. See below for details of the manufacturing method. That is, 1H-NMR (proton) of the cross-copolymer obtained by anionic polymerization in the presence of the ethylene-styrene-divinylbenzene copolymer macromonomer obtained in the coordination polymerization step and the present copolymer and styrene units. NMR) is measured, and the peak intensities of vinyl group hydrogen (protons) of both divinylbenzene units are compared using an appropriate internal standard peak (appropriate peak derived from an ethylene-styrene-divinylbenzene copolymer). Here, the peak intensity (area) of vinyl group hydrogen (proton) of the divinylbenzene unit of the cross-copolymer is compared with the same peak intensity (area) of the divinylbenzene unit of the ethylene-styrene-divinylbenzene copolymer macromonomer. And less than 50%, preferably less than 20%. In the anionic polymerization (cross-linking step), the divinylbenzene unit is copolymerized simultaneously with the polymerization of the styrene unit, and the ethylene-styrene-divinylbenzene copolymer chain and the polystyrene chain are bonded via the divinylbenzene unit. In the cross-copolymer after anionic polymerization, the peak intensity of hydrogen (proton) of vinyl group of divinylbenzene unit is greatly reduced. Actually, the hydrogen (proton) peak of the vinyl group of the divinylbenzene unit substantially disappears in the cross-copolymer after the anionic polymerization. For details, see the publicly known document “Synthesis of a branched copolymer using an olefin copolymer containing a divinylbenzene unit”, Jun Arai, Masaru Hasegawa, Journal of the Japan Rubber Association, p382, vol. 82 (2009).

From another viewpoint, in the cross copolymer (A), the ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and the aromatic vinyl compound polymer chain are bonded via an aromatic polyene monomer unit. The fact that the ethylene-styrene-divinylbenzene copolymer chain and the polystyrene chain are bonded via a divinylbenzene unit can be proved by the following observable phenomenon. That is, even after the Soxhlet extraction is carried out a sufficient number of times using an appropriate solvent, the contained ethylene-styrene-divinylbenzene copolymer chain cannot be separated from the polystyrene chain. Normally, the ethylene-styrene-divinylbenzene copolymer and polystyrene of the same composition as the ethylene-styrene-divinylbenzene copolymer chain contained in this cross copolymer are subjected to Soxhlet extraction with boiling acetone, so that the acetone insoluble part As an ethylene-styrene-divinylbenzene copolymer and as an acetone soluble part into polystyrene. However, when the same Soxhlet extraction is performed on the cross copolymer, a relatively small amount of polystyrene homopolymer contained in the cross copolymer is obtained as the acetone soluble part, but the acetone insoluble, which accounts for the majority, is obtained. The NMR measurement shows that the ethylene-styrene-divinylbenzene copolymer chain and the polystyrene chain are both contained in the part, and it can be seen that these cannot be separated by Soxhlet extraction. Details of this are also described in the publicly known document “Synthesis of a branched copolymer using an olefin copolymer containing a divinylbenzene unit”, Jun Arai, Masaru Hasegawa, Journal of Japan Rubber Association, p382, vol. 82 (2009).

From the above, the expression defining the cross copolymer of this embodiment is that the cross copolymer (A) has an ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and an aromatic vinyl compound polymer chain. And a copolymer having a structure in which an ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and an aromatic vinyl compound polymer chain are bonded via an aromatic polyene monomer unit. The cross-copolymer may contain a relatively small amount of an aromatic vinyl compound (polystyrene) homopolymer.

In one embodiment of the present invention, the cross copolymer (A) comprises an ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and an aromatic vinyl compound polymer chain via an aromatic polyene monomer unit. The copolymer has a bonding structure and further satisfies all the following conditions (1) to (3).
(1) The content of the aromatic vinyl compound monomer unit in the ethylene-aromatic vinyl compound-aromatic polyene copolymer is 10 to 23 mol%, preferably 12 to 18 mol%, The content is 0.01 mol% or more and 0.5 mol% or less, preferably 0.01 mol% or more and 0.2 mol% or less, and the balance is the content of ethylene monomer units.
(2) The ethylene-aromatic vinyl compound-aromatic polyene copolymer has a weight average molecular weight of 50,000 to 300,000 and a molecular weight distribution (Mw / Mn) of 1.8 to 6.
(3) The content of the ethylene-aromatic vinyl compound-aromatic polyene copolymer contained in the cross-copolymer is in the range of 70 to 95% by mass, preferably 82 to 92% by mass.

The weight average molecular weight Mw of the aromatic vinyl compound polymer chain is arbitrary, but is generally in the range of 10,000 to 80,000. In the cross copolymer, the molecular weight of the aromatic vinyl compound polymer chain bonded to the main chain ethylene-aromatic vinyl compound-aromatic polyene copolymer cannot be determined. The weight average molecular weight Mw of the aromatic vinyl compound polymer homopolymer contained in a relatively small amount in the copolymer is defined as the weight average molecular weight Mw of the aromatic vinyl compound polymer chain contained in the cross copolymer. Yes.

As a result of ¹ H-NMR measurement of the cross-copolymer (A), the amount of aromatic polyene (divinylbenzene) unit contained was significantly less than that of the aromatic vinyl compound (styrene) unit, and the peak position was further reduced. Since it overlaps with the aromatic vinyl compound (styrene) unit, the peak cannot be confirmed directly. Therefore, in the ¹ H-NMR measurement of the present cross-copolymer, the peak derived from the ethylene-aromatic vinyl compound copolymer (ethylene-styrene copolymer) and the peak derived from the aromatic vinyl compound polymer (polystyrene) The ethylene unit content, the aromatic vinyl compound (styrene) unit content derived from the ethylene-aromatic vinyl compound copolymer (ethylene-styrene copolymer) of the cross copolymer, and the weight of the aromatic vinyl compound The content of coalesced (polystyrene) can be determined. Here, aromatic polyene (divinylbenzene) actually contained in an ethylene-aromatic vinyl compound copolymer (ethylene-styrene-divinylbenzene copolymer) in an amount of 0.01 mol% to 0.5 mol%. ) Content is included in the aromatic vinyl compound (styrene) unit content in which the peak positions overlap, and each content is obtained. The acetone-insoluble part occupying most of the cross-copolymer contains both an ethylene-aromatic vinyl compound copolymer (ethylene-styrene copolymer) and an aromatic vinyl compound polymer (polystyrene). This cannot be separated by further fractionation operations. Therefore, in the present cross copolymer, the ethylene-aromatic vinyl compound copolymer chain and the aromatic vinyl compound polymer chain have a bond (for example, the ethylene-styrene copolymer chain and the polystyrene chain). Can be proved). This cross-copolymer is substantially free of gels and has thermoplasticity despite the fact that the ethylene-aromatic vinyl compound copolymer chain and the aromatic vinyl compound polymer chain have a bond. Practical moldability as a resin, that is, a specific MFR value can be shown.

As described above, in one embodiment of the present invention, in a thermoplastic elastomer composition obtained by blending 3 to 10 parts by mass of an acetylated monoglyceride plasticizer (B) with 100 parts by mass of a cross copolymer (A), From the viewpoint of detectability, the copolymer (A) can be defined as a copolymer that satisfies all of the following conditions (4) to (7).
(4) According to ¹ H-NMR measurement, peaks attributed to the ethylene-aromatic vinyl compound copolymer and the aromatic vinyl compound polymer were observed, and the content of the aromatic vinyl compound in the ethylene-aromatic vinyl compound was 10 -23 mol%, preferably 12-18 mol%, and the content of the ethylene-aromatic vinyl compound copolymer component contained is in the range of 70-95 wt%, more preferably 82-92 wt%,
(5) The ethylene-aromatic vinyl compound copolymer and aromatic vinyl compound polymer contained have a bond,
(6) MFR (200 ° C., weight 49 N) is in the range of 0.05 to 50 g / 10 min, more preferably in the range of 0.1 to 20 g / 10 min.
(7) The gel content is 0.2% by mass or less, more preferably 0.1% by mass or less.
The melt flow rate (MFR) can be measured according to JIS K 7210. The gel content can be determined according to ASTM-D2765-84.

(Method for producing cross-copolymer (A))
The manufacturing method of the cross copolymer (A) based on this invention is demonstrated. The polymerization mode is not particularly limited and can be produced by a known method such as solution polymerization or bulk polymerization, but is more preferable because solution polymerization has a high degree of freedom in controlling polymerization in obtaining a desired cross-copolymer. is there.

The polymerization method is not particularly limited as long as the desired cross-copolymer (A) can be obtained. A coordination polymerization step of polymerizing an olefin-aromatic vinyl compound copolymer using a coordination polymerization catalyst, and a coordination In the coexistence of the olefin-aromatic vinyl compound copolymer obtained in the polymerization step and the aromatic vinyl compound monomer, polymerization is performed using an anionic polymerization initiator to form an aromatic polyene monomer unit of the main chain. By a production method that undergoes a two-step polymerization process comprising an anionic polymerization process for producing a cross-copolymer (A) having a structure in which a polymer comprising an aromatic vinyl compound monomer unit is formed as a cross chain on the remaining vinyl group It is possible to manufacture.

(Coordination polymerization process)
The coordination polymerization process will be specifically described. As the coordination polymerization catalyst, a single site coordination polymerization catalyst composed of a transition metal compound and a promoter can be used. Methylaluminoxane can be suitably used as a cocatalyst that assists the activity of the single site coordination polymerization catalyst. Moreover, in order to remove the water | moisture content contained in a solvent and each monomer raw material, and to suppress the poisoning of a single site coordination polymerization catalyst, alkyl aluminum can be used suitably. The solvent to be used is preferably a hydrocarbon system such as cyclohexane, methylcyclohexane, toluene, ethylbenzene, or an aromatic hydrocarbon system because it poisons the single-site coordination polymerization catalyst if it has a polar functional group. The amount of the solvent added is preferably 200 to 900 parts by mass with respect to 100 parts by mass of the obtained copolymer. If it is 200 mass parts or more, it is suitable when controlling a polymerization-solution viscosity and reaction rate, and if it is 900 mass parts or less, it is preferable from a viewpoint of productivity.

(Anionic polymerization process)
The anionic polymerization process will be specifically described. In the anionic polymerization step, the main chain is polymerized by using an anionic polymerization initiator in the coexistence of the olefin-aromatic vinyl compound copolymer obtained in the coordination polymerization step and the aromatic vinyl compound monomer. A cross-copolymer (A) having a structure in which a polymer composed of an aromatic vinyl compound monomer unit is cross-linked to a vinyl group remaining in the aromatic polyene monomer unit is synthesized. The olefin-aromatic vinyl compound copolymer obtained in the coordination polymerization step is precipitated by a poor solvent such as methanol, the solvent is evaporated by a heating roll or the like (drum dryer method), and the concentrator. Concentrate the solution after removing the solvent with a vent type extruder, disperse the solution in water, blow off water vapor to remove the solvent by heating (steam stripping method), crumb forming Any method such as a method may be used for the anionic polymerization step after separation and purification from the polymerization solution after the coordination polymerization. In addition, a polymerization solution containing an olefin-aromatic vinyl compound copolymer may be used in the anionic polymerization step without separating and purifying the olefin-aromatic vinyl compound copolymer from the polymerization solution. Is preferable from the viewpoint of productivity. As the anionic polymerization initiator, known anionic polymerization initiators such as n-butyllithium and sec-butyllithium can be used. As the aromatic vinyl compound monomer, the aromatic vinyl compound monomer remaining in the polymerization solution after the coordination polymerization can be used as it is. Moreover, the target cross-copolymer (A) can be obtained by adding a required amount before the start of anionic polymerization, or adding or adding in the middle of anionic polymerization.

(Recovery process)
The method for recovering the cross-copolymer (A) is not particularly limited, a method for precipitation with a poor solvent such as methanol, a method for evaporation by evaporation with a heating roll or the like (drum dryer method), and a solution of water. A known method such as a method of recovering a copolymer by blowing water vapor and removing the solvent by heating (a steam stripping method) or a crumb forming method can be used. Further, there is a method in which a polymerization solution is continuously fed to a twin-screw devolatilizing extruder using a gear pump, and a polymerization solvent is devolatilized. This method is economical because the devolatilizing component containing the polymerization solvent is condensed and recovered using a condenser, etc., and the polymerization solvent can be reused by purifying the condensate in the distillation tower. It is preferable from the viewpoint.

For details of the present cross-copolymer and its production method, the entire description thereof is incorporated herein by reference, International Publication No. 2000/37517, International Publication No. 2007/139116, or Japanese Patent Application Laid-Open No. 2009-12092. It is described in the publication.

(Acetylated monoglyceride plasticizer (B))
Examples of the acetylated monoglyceride plasticizer (B) used in the present invention include, but are not limited to, acetylated monolauryl glyceride, acetylated monocapryl glyceride, acetylated monostearyl glyceride, and acetylated monooleyl. A glyceride is mentioned.
These plasticizers may be used alone or in combination.

The plasticizer used in the present invention is preferably an acetylated monoglyceride plasticizer from the viewpoints of transparency and blocking resistance. Particularly preferred is substantially acetylated monolauryl glyceride. If the acetylated monoglyceride plasticizer (B) is substantially acetylated monolauryl glyceride, it is particularly preferred because blocking resistance is improved. Here, “substantially” means that 70% by mass or more of the contained plasticizer is acetylated monolauryl glyceride. The structure of the glycerin fatty acid ester plasticizer (B) used was measured by performing composition analysis using ACQUITY UPLC manufactured by Waters as a liquid chromatography (LC) and Synapt G2 manufactured by Waters as a mass spectrometer (MS). .

As the acetylated monoglyceride plasticizer (B), a commercially available product can be used, and it can also be produced using a known production method. These acetylated monoglyceride lubricants can be purchased from, for example, Riken Vitamin.

The blending amount of the acetylated monoglyceride plasticizer (B) is preferably 3 to 10 parts by mass of the acetylated monoglyceride plasticizer (B) with respect to 100 parts by mass of the cross copolymer (A). If the amount of the acetylated monoglyceride plasticizer (B) is 3 parts by mass or more, low temperature curing is suppressed, which is preferable. A blending amount of the acetylated monoglyceride plasticizer (B) of 10 parts by mass or less is preferable because a decrease in tensile strength is suppressed. From the viewpoints of transparency, softness, low temperature properties, tensile properties, and blocking resistance of the thermoplastic elastomer composition of the present embodiment, the blending amount of the acetylated monoglyceride plasticizer (B) is most preferably 4 to 8 parts by mass.

The thermoplastic elastomer composition of this embodiment is excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance. Specifically, the transparency is 20% or less for a 1 mm-thick sheet, the softness is 79 or less in terms of A hardness, the tensile property is a tensile stress of 3.0 MPa or more at 23 ° C. and 100% elongation, and Tensile stress at 5 ° C. and 100% elongation is 7.5 MPa or less, low temperature characteristics (low temperature curing), the difference in tensile stress at 100% elongation at 5 ° C. and 23 ° C. is 3.5 MPa or less, The anti-blocking property is evaluated by the method defined in this example, and the evaluation level is 2 or more. Furthermore, most preferably, the transparency is 15% or less for a 1 mm thick sheet, the softness is 75 or less in terms of A hardness, and the tensile properties are 23 ° C., 100% elongation tensile stress 3.5 MPa or more, And the tensile stress at 100% elongation at 5 ° C is 6.5 MPa or less, and the low temperature property (low temperature curing) is the difference between the tensile stress at 100% elongation at 5 ° C and 23 ° C is 3.0 MPa or less. The anti-blocking property is evaluated by the method defined in this example, and the evaluation level is 3 or more.

In the thermoplastic elastomer composition of the present invention, a lubricant, a stabilizer, an antistatic agent, an impact strength improver, a processing aid, an ultraviolet absorber, and an antioxidant are added to the thermoplastic elastomer composition of the present invention, as necessary. Agent, organic or inorganic foaming agent, crosslinking agent, co-crosslinking agent, crosslinking aid, pressure-sensitive adhesive, softener, color pigment, flame retardant, for example, with respect to 100 parts by mass of the cross-copolymer (A), It can add in the ratio of 0.01 mass part or more and 10 mass parts or less.
Further, other thermoplastic resins such as ethylene-based resins, propylene-based resins, or styrene-diene block copolymers such as SBS, SIS, SEBS, and SEPS and hydrogenated products thereof may be used as the cross-copolymer (A) 100. It can add in the ratio of 1 to 30 mass parts with respect to the mass part.

The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited, but a single-screw extruder, a mating co-rotating or mating counter-rotating twin-screw extruder, a non- or incomplete mating two It can be manufactured using a known melt-kneading apparatus such as a screw extruder such as a screw extruder, Banbury mixer, a kneader, and a mixing roll. Among them, the melt-mixing method using an extruder is from the viewpoint of productivity and good kneadability. preferable.

The thermoplastic elastomer composition of the present embodiment is excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance, and can be used for various molded articles, particularly suitable for sheets and medical tubes. It is. There is no restriction | limiting in particular in the shaping | molding method of a molded object, Well-known methods, such as an extrusion molding method, an injection molding method, a blow molding method, a rotation molding method, can be used.

The thermoplastic elastomer composition of the present invention can be synthesized by, for example, synthesis described in JP2009-102515A, WO09 / 128444, WO13 / 018171, or JP2011-153214A. It is suitably used for leather, grips or exterior members, foams, skin materials, tape substrates, wire coating materials, gaskets, or conductive sheets. The sheet using the thermoplastic elastomer composition of the present invention may be a single layer or a multilayer. In the case of a multilayer, you may use as a multilayer which has the layer which consists of another resin component. The thermoplastic elastomer composition of the present invention is, for example, a medical device described in International Publication No. 2007/139116, Japanese Unexamined Patent Publication No. 2009-120922, Japanese Unexamined Patent Publication No. 2013-202133, or International Publication No. 2013/137326. It is suitably used for tubes. The medical tube using the thermoplastic elastomer composition of the present invention may be a single layer or multiple layers. Moreover, in the case of a multilayer, you may use as a multilayer which has the layer which consists of another resin component.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, these are all illustrations and do not limit the content of this invention.
The raw material resins and production methods used in Examples and Comparative Examples are as follows.

Cross copolymer (A)
The following cross copolymers 1 to 7 were used.
These cross-copolymers were produced by the production methods of Examples or Comparative Examples described in International Publication No. 2000/37517, International Publication No. 2007/139116, and Japanese Unexamined Patent Publication No. 2009-12092. Was similarly determined by the method described in these publications. In other words, the composition in the cross-copolymer or ethylene-aromatic vinyl compound-aromatic polyene copolymer, ie, the content of ethylene, aromatic vinyl compound or aromatic vinyl compound polymer is determined by ¹ H-NMR (proton NMR). The content of aromatic polyene in the ethylene-aromatic vinyl compound-aromatic polyene copolymer was determined from the amount of aromatic polyene charged at the time of polymerization and gas chromatographic analysis of the polymerization solution sampled after completion of coordination polymerization. It calculated by calculating | requiring the amount of aromatic polyene used for superposition | polymerization from the difference of the amount of unreacted aromatic polyene, and comparing with the amount of the copolymer obtained by superposition | polymerization. The molecular weight in the polymerization solution was determined by GPC measurement. The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polystyrene chain were determined by GPC measurement of the aromatic vinyl compound polymer separated by solvent fractionation.
In these cross copolymers, the vinyl group hydrogen (proton) peak intensity (area) of the divinylbenzene unit is the same peak of the divinylbenzene unit of the ethylene-styrene-divinylbenzene copolymer obtained in the coordination polymerization step. The strength (area) was less than 20%. Actually, the hydrogen (proton) peak of the vinyl group of the divinylbenzene unit substantially disappeared in the cross-copolymer after anionic polymerization. In addition, the cross copolymer was subjected to Soxhlet extraction using boiling acetone. The ethylene-styrene-divinylbenzene copolymer chain (substantially ethylene-styrene copolymer chain) and the polystyrene chain contained therein were removed. I couldn't sort it. The styrene content, divinylbenzene content, weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) of the ethylene-styrene-divinylbenzene copolymer used to define the cross copolymer, the cross copolymer The ethylene-styrene-divinylbenzene copolymer content, polystyrene chain weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), and MFR are shown. The gel content measured by ASTM-D2765-84 was less than 0.1% by mass (below the lower limit of detection) in any cross-copolymer.
The measurement conditions for GPC are as follows.
<GPC measurement conditions>
Device name: HLC-8220 (manufactured by Tosoh Corporation)
Column: Four series of Shodex GPC KF-404HQ Temperature: 40 ° C
Detection: Differential refractive index Solvent: Tetrahydrofuran Calibration curve: Prepared using standard polystyrene (PS).

Cross copolymer (A-1)
An ethylene-styrene-divinylbenzene copolymer having a styrene content of 11 mol%, a divinylbenzene content of 0.06 mol%, a weight average molecular weight of 121,000, a molecular weight distribution of 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 88% by mass,
-Weight average molecular weight of polystyrene chain 13,000, molecular weight distribution 1.2
A hardness 83
-MFR 0.7g / 10min (200 ° C, weight 49N)
Cross copolymer (A-2)
An ethylene-styrene-divinylbenzene copolymer having a styrene content of 15 mol%, a divinylbenzene content of 0.06 mol%, a weight average molecular weight of 141,000, a molecular weight distribution of 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 94% by mass,
-Weight average molecular weight of polystyrene chain 15000, molecular weight distribution 1.2
・ A hardness 76
-MFR is 0.9g / 10 min (200 ° C, weight 49N)
Cross copolymer (A-3)
-Styrene content 15 mol%, divinylbenzene content 0.06 mol%, weight average molecular weight 131000, molecular weight distribution 2.2, ethylene-styrene-divinylbenzene copolymer,
-Content of ethylene-styrene-divinylbenzene copolymer: 88% by mass,
-Weight average molecular weight of polystyrene chain 14,000, molecular weight distribution 1.2
・ A hardness 78
-MFR 1.3g / 10min (200 ° C, weight 49N)
Cross copolymer (A-4)
-Styrene content of ethylene-styrene-divinylbenzene copolymer 15 mol%, divinylbenzene content 0.06 mol%, weight average molecular weight 112000, molecular weight distribution 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 81% by mass,
-Weight average molecular weight of polystyrene chain 13,000, molecular weight distribution 1.2
A hardness 81
・ MFR is 2.5g / 10min (200 ℃, weight 49N)
Cross copolymer (A-5)
An ethylene-styrene-divinylbenzene copolymer having a styrene content of 19 mol%, a divinylbenzene content of 0.05 mol%, a weight average molecular weight of 141,000, a molecular weight distribution of 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 85% by mass,
-Weight average molecular weight of polystyrene chain 15000, molecular weight distribution 1.2
A hardness 73
-MFR 5.2g / 10min (200 ° C, weight 49N)
Cross copolymer (A-6)
-The styrene content of the ethylene-styrene-divinylbenzene copolymer is 8 mol%, the divinylbenzene content is 0.06 mol%, the weight average molecular weight is 111,000, the molecular weight distribution is 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 88% by mass,
-Weight average molecular weight of polystyrene chain 12000, molecular weight distribution 1.2
・ A hardness 87
・ MFR 0.5g / 10min (200 ℃, weight 49N)
Cross copolymer (A-7)
-Styrene content of 25 mol%, divinylbenzene content of 0.05 mol%, weight average molecular weight of 151,000, molecular weight distribution of ethylene-styrene-divinylbenzene copolymer, 2.2,
-Content of ethylene-styrene-divinylbenzene copolymer: 83% by mass,
-Weight average molecular weight of polystyrene chain 16000, molecular weight distribution 1.2
・ A hardness 67
-MFR is 7.3 g / 10 min (200 ° C, weight 49N)

Acetylated monoglyceride plasticizer (B)
Acetylated monoglyceride plasticizer (B-1): Acetylated monolauryl glyceride Riquemar PL-012 (manufactured by Riken Vitamin Co., Ltd.) was used. The content of acetylated monolauryl glyceride was 80% by mass or more.
A mixture of acetylated monoglyceride plasticizer (B-2): acetylated monolauryl glyceride: acetylated monocaprylic glyceride (mass ratio 50:50) Riquemar PL-019 (manufactured by Riken Vitamin Co., Ltd.) was used.
The structures of the plasticizers (B-1) to (B-2) used were subjected to composition analysis using ACQUITY UPLC manufactured by Waters as a liquid chromatography (LC) and SynaptG2 manufactured by Waters as a mass spectrometer (MS). Performed and measured.
Other plasticizers (C)
Other plasticizer (C-1): Liquid paraffin Hicol M-352 (manufactured by Kaneda) was used.
The structure of the plasticizer (C-1) used was measured by composition analysis using ACQUITY UPLC manufactured by Waters as a liquid chromatography (LC) and SynaptG2 manufactured by Waters as a mass spectrometer (MS). The results are shown in Table 1.

[Examples 1 to 9, Comparative Examples 1 to 6]
Table 3 shows the ratios of the cross copolymers (A-1) to (A-7) and the acetylated monoglyceride plasticizers (B-1) to (B-2) or other plasticizers (C-1). (Mass part) was melt-kneaded at a cylinder temperature of 200 ° C. with a twin-screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.) and pelletized to obtain a thermoplastic elastomer composition. About the obtained thermoplastic elastomer composition, the test piece according to the following evaluation criteria was created and evaluated. The results are shown in Table 2.

(Creation of specimen)
Sheet preparation was as follows. As a sample for physical property evaluation, a square mirror surface press sheet having a thickness (1 mm) formed by a heat press method (200 ° C., time 5 minutes, pressure 50 kg / cm 2) using a mirror surface mold (manufactured by STAVAX) was used. .

(transparency)
A haze meter (Nippon Denshoku Industries Co., Ltd. NDH-1001DP type) was used to measure the haze of a square mirror surface press sheet having a thickness of 1 mm and a side of 50 mm in accordance with JIS K7136. In addition, the haze of 20% or less was set as an acceptable level, and 15% or less was set as a particularly preferable level.

(Tensile properties)
Based on JIS K6251, the tensile stress at 100% elongation under 23 ° C. and 5 ° C. conditions was determined. The tensile stress at 100% elongation is the tensile stress when 100% elongation is given to the test piece. As a test piece, a 1 mm thick press sheet was punched into a No. 3 dumbbell mold and used. The tensile speed was 500 mm / min. In addition, the tensile property is a tensile stress of 3.0 MPa or more at 23 ° C. and 100% elongation and the tensile stress is 7.5 MPa or less at 100 ° elongation of 5 ° C., and the tensile property is a tensile stress of 3 at 23 ° C. and 100% elongation. A tensile stress of 6.5 MPa or less at 5 ° C. and 100% elongation was set to a particularly preferable level.

(Low temperature curing)
The tensile stress at 100% elongation under 5 ° C and 23 ° C conditions was determined by the above method, and the difference between the measured value under 23 ° C condition and the measured value under 5 ° C condition was determined. In addition, low temperature hardening made 3.5 MPa or less into the pass level, and made 3.0 MPa or less into the most preferable level.

(Softness)
In accordance with JIS K6253-3, instantaneous hardness was determined using type A durometer hardness. Six 1 mm-thick press sheets were used as test pieces. In addition, A hardness 79 or less was made into the acceptable level, and 75 or less was made into the most preferable level.

(Blocking resistance)
Two square mirror press sheets with a thickness of 1 mm and a side of 60 mm are superposed and a 60 mm diameter disc-shaped weight (100 g, 300 g) is placed, left at 60 ° C. for 2 hours, the weight is removed, and the corner of the top press sheet is removed. The blocking property was evaluated according to the following criteria by lifting and observing the ease of peeling of the press sheet on the lower surface. The test was performed three times for each sample.
3: The press sheet peeled off without sticking with all the weights.
2: The press sheet peeled off without sticking with the 100 g weight, or peeled off due to its own weight even when stuck, but there was a thing stuck with the 300 g weight but not peeled off by its own weight.
1: There was a thing stuck with all the weights and not peeled off by its own weight.
0: Some press sheets were stuck and could not be removed by their own weight without placing a weight.
In addition, 2 or more was made into the pass level, and 3 or more was made into the most preferable level.

For Examples 1 to 9, all had a haze of 20% or less, 23 ° C., 100% elongation tensile stress of 3.0 MPa or more, 5 ° C., 100% elongation tensile stress of 7.5 MPa or less, low temperature curing of 3.5 MPa or less, A It had a hardness of 79 or less and a blocking resistance evaluation of 2 or more, was excellent in transparency, tensile properties, softness and blocking resistance, and low-temperature curing was suppressed. On the other hand, Comparative Examples 1 to 6 were inferior in any of physical properties among transparency, tensile properties, softness and anti-blocking properties, or weakly suppressed at low temperature.

[Compatibility evaluation for medical tubes]
[Example 10]
Using the thermoplastic elastomer composition obtained in Example 2, a tube having an outer diameter of 3.6 mm, an inner diameter of 2.4 mm, and a tube thickness of 0.6 mm was formed by extrusion molding. The characteristics as a medical tube were evaluated according to the following criteria. The results are shown in Table 3.

(Tube softness)
The subject is touched at 23 ° C. with the prepared tube cut to a length of 20 cm and a comparative soft polyvinyl chloride medical single-layer tube, and the one with the soft touch is selected. If the created tube was softer than a soft polyvinyl chloride medical single-layer tube, ◎ (excellent), if equal, ○ (good), and if the created tube was clearly hard, × (impossible). As for the softness of the tube, ○ (good) or better was regarded as acceptable.

(Softness of the tube under 5 ° C condition)
The subject is touched at 5 ° C. with the prepared tube cut to a length of 20 cm and a comparative soft polyvinyl chloride medical single-layer tube, and the one with the soft touch is selected. If the created tube was softer than a soft polyvinyl chloride medical single-layer tube, ◎ (excellent), if equal, ○ (good), and if the created tube was clearly hard, × (impossible). As for the softness of the tube, ○ (good) or better was regarded as acceptable.

(transparency)
Saline was poured into the tube, and it was observed whether the liquid level, bubbles, etc. were visible with the naked eye. The case where it was easy to observe was marked with ◯ (good), and the case where observation was difficult was marked with x (impossible).

(Eluate test based on sterilized infusion set standards)
In accordance with JIS T3211, the eluate test was performed based on the sterilized infusion set standard, and the pH, heavy metal, potassium permanganate reducing substance, and evaporation residue were measured. The following pH, heavy metal, potassium permanganate reducing substance, evaporation residue test solution and blank test solution were obtained as follows.
Test solution: 10 g of the tube portion was cut into about 1 cm length, and boiled with 100 mL of distilled water for 30 minutes to obtain a test solution.
Blank test solution: 100 mL of distilled water was boiled for 30 minutes to obtain a blank test solution.

(PH)
Take 20 mL each of the test solution and the blank test solution, add 1.0 mL each of these solutions to 1000 mL by dissolving 1.0 g of potassium chloride in water, and measure the pH change by the pH measurement method of the Japanese Pharmacopoeia General Test Method did. A pH difference of 2.0 or less was accepted.

(heavy metal)
10 mL of the test solution was taken and the test was carried out according to the first method of the Japanese Pharmacopoeia heavy metal test method. To the blank test solution, 2.0 mL of lead standard solution was added and the test was performed in the same manner. If the color became darker than the blank test solution, the test was accepted.

(Potassium permanganate reducing substance)
Take 10 mL of the test solution in a stoppered Erlenmeyer flask, add 20.0 mL of 0.002 mol / L potassium permanganate solution and 1 mL of dilute sulfuric acid, seal tightly, shake and leave for 10 minutes, then 0.01 mol / L sodium thiosulfate solution (5 drops of indicator starch test solution). Separately, 10 mL of blank test solution is used and the same operation is performed. If the difference in the consumption of 0.002 mol / L potassium permanganate solution between the test solution and the blank test solution was 2.0 mL or less, the test was accepted.

(Evaporation residue)
10 mL of the test solution was evaporated to dryness on a water bath, and when the residue was dried at 105 ° C. for 1 hour, if the weight was 1.0 mg or less, the test was accepted.

(Kink start radius)
A 20 cm tube was bent to each radius of curvature, and the minimum radius of curvature at which the occurrence of bending of the tube was not confirmed after 1 minute was determined. The kink start radius is preferably 10 mm or less. Moreover, the shape of the generated kink (bending) was observed. Observe the situation where crushing occurs relatively uniformly in a wide part of the tube.
◎ (excellent): Wide kink is generated and crushing occurs in a narrower range ○ (good): A relatively wide kink is generated, crushing occurs in a narrower range, and the tube is broken △ (defective) ): Classified as acute-angle kink. The shape of the kink was set to pass (good) or better.

(Forceps resistance)
At 40 ° C., the tube filled with physiological saline was closed with medical tube forceps for 10 hours, and then the forceps were removed, and the time during which the inside of the tube recovered its shape and the liquid penetrated was used as an index of the forceps resistance of the tube. .

(Drug adsorption)
Nitroglycerin adsorptivity: Nitroglycerin injection solution (active ingredient 50 mg / 100 mL, Millisrol injection, Nippon Kayaku Co., Ltd.) 60 mL was injected into 1 L of Japanese Pharmacopoeia physiological saline and gently stirred. Immediately, the sample was sampled with a syringe with a syringe needle to obtain a blank. The tube of the infusion set was closed with a flow rate adjusting clamp, and the drip tube was pierced through a rubber stopper. The lower half of the drip tube was filled with the solution by pumping the drip tube. The clamp for adjusting the flow rate was gradually loosened, and the tube was filled with the solution, and then set on the infusion pump. The flow rate was set to 36 mL / h, the flow rate adjusting clamp was opened, the switch was turned on, and infusion was started. The solution flowing out from the tip was sampled over time, and the concentration was measured using ACQUITY UPLC manufactured by Waters as liquid chromatography (LC). The infusion was performed for 180 minutes, and the first 60 minutes were sampled every 5 minutes and thereafter every 15 minutes. If the density drop was within 10% compared to the blank density, the test was accepted.

(Infusion pump suitability)
The tube was closed with a flow rate adjusting clamp, and the drip tube was pierced through a rubber stopper of Japanese Pharmacopoeia saline. The lower half of the drip tube was filled with the saline by pumping the drip tube. The flow rate adjusting clamp was gradually loosened, and the tube was filled with the saline solution, and then set on the infusion pump. The flow rate was set to 250 mL / h, the flow rate adjusting clamp was opened, the switch was turned on, and infusion was started. Immediately after this, the amount of physiological saline per minute flowing out from the tip was measured and used as the initial flow rate. After 24 hours, the flow rate per minute was again measured in the same manner. If the rate of change in flow rate after 24 hours was within 10%, it was considered acceptable.
Tube state after completion of pump infusion: After completion of the above-mentioned pump flow rate stability, the squeezed portion of the tube was incised, and the surface state of the inner and outer surfaces, the change in tube diameter, and the presence or absence of cracks were observed.

(Gamma ray resistance)
After irradiating the tube with gamma rays (25 kGy), color tone and transparency were observed with the naked eye.

(Electron beam resistance)
Using the Iwasaki Electric EB equipment TYPE: CB250 / 15 / 180L, irradiation was performed twice from the top and bottom of the sheet under the conditions of an acceleration voltage of 250 kV and an irradiation dose of 30 kGy. The color tone and transparency were observed with the naked eye.

The thermoplastic elastomer composition of the present invention is excellent in transparency, softness, low temperature characteristics, tensile characteristics, and blocking resistance, and can be suitably used for molded articles, sheets, and medical tubes.

Claims

Olefin-aromatic vinyl compound copolymer in which aromatic vinyl compound monomer unit is 10 to 23 mol%, aromatic polyene monomer unit is 0.01 to 0.5 mol%, and the balance is olefin monomer unit Of acetylated monoglyceride plasticizer (B) 3 to 100 parts by mass of a cross-copolymer (A) comprising a main chain of the above and a cross-chain of an aromatic vinyl compound polymer comprising an aromatic vinyl compound monomer unit. A thermoplastic elastomer composition comprising 10 parts by mass.
The thermoplastic elastomer according to claim 1, wherein the cross-copolymer (A) contains 70 to 95% by mass of the olefin-aromatic vinyl compound copolymer and 5 to 30% by mass of the aromatic vinyl compound polymer. Composition.
The thermoplastic elastomer composition according to claim 1, wherein the aromatic vinyl compound monomer unit is styrene.
The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the olefin monomer unit is ethylene.
The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the aromatic polyene monomer unit is divinylbenzene.
The thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the acetylated monoglyceride plasticizer (B) is substantially acetylated monolauryl glyceride.
The cross copolymer (A) has a structure in which an ethylene-aromatic vinyl compound-aromatic polyene copolymer chain and an aromatic vinyl compound polymer chain are bonded via an aromatic polyene monomer unit. The thermoplastic elastomer composition according to any one of claims 1 to 6, wherein the thermoplastic elastomer composition further satisfies the following conditions (1) to (3).
(1) The content of the aromatic vinyl compound monomer unit in the ethylene-aromatic vinyl compound-aromatic polyene copolymer is 10 to 23 mol%, and the content of the aromatic polyene monomer unit is 0.01 mol% or more. 0.5 mol% or less, and the balance is the content of ethylene monomer units.
(2) The ethylene-aromatic vinyl compound-aromatic polyene copolymer has a weight average molecular weight of 50,000 to 300,000 and a molecular weight distribution (Mw / Mn) of 1.8 to 6.
(3) The content of the ethylene-aromatic vinyl compound-aromatic polyene copolymer contained in the cross copolymer is in the range of 70 to 95% by mass.
A thermoplastic elastomer composition comprising 3 to 10 parts by mass of an acetylated monoglyceride plasticizer (B) per 100 parts by mass of a cross copolymer (A), wherein the cross copolymer (A) is: A thermoplastic elastomer composition satisfying all the following conditions (4) to (7):
(4) By 1 H-NMR measurement, peaks attributed to the ethylene-aromatic vinyl compound copolymer and aromatic vinyl compound polymer were observed, and the aromatic vinyl compound in the ethylene-aromatic vinyl compound copolymer was observed. The content is 10 to 23 mol%, and the content of the ethylene-aromatic vinyl copolymer component contained is in the range of 70 to 95% by mass,
(5) The ethylene-aromatic vinyl compound copolymer and aromatic vinyl compound polymer contained have a bond,
(6) MFR (200 ° C., weight 49 N) is in the range of 0.05 to 50 g / 10 minutes,
(7) The gel content is 0.2% by mass or less.
A molded body using the thermoplastic elastomer composition according to any one of claims 1 to 8.
The molded article according to claim 9, which is a sheet.
The molded body according to claim 9, which is a medical tube.