JP7064130B2 - Olefin-based thermoplastic elastomer with excellent transparency - Google Patents

Description

The present invention relates to a thermoplastic elastomer having excellent transparency. Specifically, by blending a diacetal compound having a specific structure with a specific olefin-based thermoplastic elastomer, the mechanical properties such as flexibility and strength are not impaired. With respect to thermoplastic elastomers with significantly improved transparency.

Thermoplastic elastomer has rubber elasticity similar to that of vulcanized rubber at room temperature, does not require a vulcanization step like vulcanized rubber, and can be plasticized and melted by heating like thermoplastic resin. Since it is easy to mold and can be recycled, it has been used in a wide range of fields such as automobile parts, home appliance parts, medical parts, building materials, toys, sporting goods, and daily necessities in recent years. Examples of such thermoplastic elastomers include olefin-based, styrene-based, urethane-based, ester-based, amide-based, vinyl chloride-based, etc. Among them, olefin-based thermoplastic elastomers are lightweight and have more moldability. It also has various features such as excellentness, and is widely used in the above fields (Non-Patent Documents 1 and 2).

Recently, thermoplastic elastomers are often used in applications such as medical materials, covering materials, packaging materials, and toys that require transparency from the viewpoint of visibility and design, and are flexible. As a matter of course, there is a demand for a thermoplastic elastomer having excellent mechanical properties such as strength and further excellent transparency. Conventionally, in applications requiring such transparency, for example, specific ester-based and acrylate-based elastomers have been put into practical use in some applications (Patent Documents 1 to 3). However, the above-mentioned elastomers are not versatile, and attempts have been made to improve the transparency of thermoplastic elastomers such as olefins with high versatility (Patent Document 4), but the transparency is satisfactory so far. The current situation is that it is difficult to obtain. Therefore, it is desired to improve the transparency of general-purpose plastic elastomers such as olefins.

Japanese Unexamined Patent Publication No. 2000-6364 Japanese Unexamined Patent Publication No. 2007-126527 Japanese Unexamined Patent Publication No. 2016-79226 Japanese Patent Publication No. 2007-511643

Japan Rubber Association Paper, Vol. 51, No. 10, 779-796 (1978) Japan Rubber Association Paper, Vol. 83, No. 9, 269-276 (2010)

An object of the present invention is to improve the transparency of an olefin-based thermoplastic elastomer which is a general-purpose thermoplastic elastomer, and to provide an olefin-based thermoplastic elastomer having excellent transparency, and for that purpose, a specific olefin-based It is an object of the present invention to provide an olefin-based thermoplastic elastomer composition comprising the thermoplastic elastomer of the above and a diacetal compound having a specific structure.

As a result of diligent studies to solve the above problems, the present inventors have obtained mechanical properties such as flexibility and strength by blending a diacetal compound having a specific structure with an olefin-based thermoplastic elastomer having a specific structure. It was confirmed that the transparency could be greatly improved without impairing the transparency, and as a result, it was found that a thermoplastic elastomer having very excellent transparency could be obtained, and the present invention was completed based on this.

That is, the present invention is a method for improving the transparency of a thermoplastic elastomer shown below, an olefin-based thermoplastic elastomer composition, and an olefin-based thermoplastic elastomer whose transparency is improved by the method using the composition as a raw material. Regarding molded products.

［式（１）中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシ基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシカルボニル基又はハロゲン原子を示す。Ｒ^３は、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数２～４のアルケニル基又は直鎖状若しくは分岐鎖状の炭素数１～４のヒドロキシアルキル基を示す。ｍ及びｎは、それぞれ１～５の整数を示す。ｐは０又は１を示す。２つのＲ^１は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。２つのＲ^２基は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。］ [Item 1] An olefin-based thermoplastic elastomer composition having excellent transparency, in which a diacetal compound represented by the following general formula (1) is added from 0.05 to 100 parts by mass of the olefin-based thermoplastic elastomer. An olefin-based thermoplastic elastomer composition containing 5.0 parts by mass.

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. The two R1s may be bonded to ^each other to form a tetralin ring with the benzene ring to which they are bonded. The two ^R2 groups may be bonded to each other to form a tetralin ring with the benzene ring to which they are bonded. ]

[Item 2] The olefin-based thermoplastic elastomer contains 60 to 99% by mass of propylene-inducing units with respect to the total mass of the thermoplastic elastomer and 1 to 40% by mass of ethylene with respect to the total mass of the thermoplastic elastomer. Item 6. The item 1], wherein the copolymer is composed of an induction unit and / or an α-olefin induction unit having 4 to 10 carbon atoms, and the heat of fusion measured by the differential scanning calorific value analysis is 50 J / g or less. An olefin-based thermoplastic elastomer composition.

[Item 3] The olefin-based thermoplastic elastomer contains 70 to 97% by mass of propylene-inducing units with respect to the total mass of the thermoplastic elastomer and 3 to 30% by mass of ethylene with respect to the total mass of the thermoplastic elastomer. Item 2. The item 2], wherein the copolymer is composed of an induction unit and / or an α-olefin induction unit having 4 to 10 carbon atoms, and the heat of fusion measured by the differential scanning calorific value analysis is 30 J / g or less. An olefin-based thermoplastic elastomer composition.

[Item 4] Any of [Item 1] to [Item 3], in which the maximum melting peak temperature measured by the differential scanning calorimetry is 115 ° C. or less, or the melting peak temperature is not observed by the measurement of the differential scanning calorimetry. The olefin-based thermoplastic elastomer composition according to.

[Item 5] In the general formula (1), R ¹ and R ² are the same or different, and the diacetal compound is a methyl group or an ethyl group, and R ³ is a hydrogen atom, and m and n are. The olefin-based thermoplastic elastomer composition according to any one of [Item 1] to [Item 4], which is an integer of 1 or 2 and p is 1.

[Item 6] In the general formula (1), R ¹ and R ² are the same or different, and the diacetal compound is a propyl group or a propoxy group, and R ³ is a propyl group or a propenyl group. The olefin-based thermoplastic elastomer composition according to any one of [Item 1] to [Item 4], wherein n is 1 and p is 1.

[Item 7] The olefin-based compound according to any one of [Item 1] to [Item 6], wherein the content of the diacetal compound is 0.05 to 1.0 part by mass with respect to 100 parts by mass of the thermoplastic elastomer. Thermoplastic elastomer composition.

[Item 8] A thermoplastic elastomer molded product having excellent transparency, using the olefin-based thermoplastic elastomer composition according to any one of [Item 1] to [Item 7] as a raw material.

［式（１）中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシ基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシカルボニル基又はハロゲン原子を示す。Ｒ^３は、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数２～４のアルケニル基又は直鎖状若しくは分岐鎖状の炭素数１～４のヒドロキシアルキル基を示す。ｍ及びｎは、それぞれ１～５の整数を示す。ｐは０又は１を示す。２つのＲ^１は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。２つのＲ^２基は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。］ [Item 9] A method for improving the transparency of a thermoplastic elastomer, wherein the diacetal compound is contained in an amount of 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the olefin-based thermoplastic elastomer, and further, the olefin-based thermoplastic elastomer is contained. The thermoplastic elastomer of the above is 60 to 99% by mass of propylene inductive units based on the total mass of the thermoplastic elastomer, and 1 to 40% by mass of ethylene inductive units and / or carbon based on the total mass of the thermoplastic elastomer. It is a copolymer composed of α-olefin induction units of several 4 to 10, further, the heat of fusion measured by differential scanning calorific value analysis is 50 J / g or less, and the diacetal compound is represented by the following general formula (1). An improvement method characterized by being the indicated compound.

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. The two R1s may be bonded to ^each other to form a tetralin ring with the benzene ring to which they are bonded. The two ^R2 groups may be bonded to each other to form a tetralin ring with the benzene ring to which they are bonded. ]

By using the method of the present invention and the olefin-based thermoplastic elastomer composition, it is possible to impart excellent transparency to the olefin-based thermoplastic elastomer, which has been a problem so far, and it has become possible to impart excellent transparency to the olefin-based elastomer. It is possible to use an olefin-based elastomer that is lightweight and has excellent recyclability even in applications that require transparency, which was difficult to use.

<Olefin-based thermoplastic elastomer composition>
The olefin-based thermoplastic elastomer of the present invention is characterized by containing an olefin-based thermoplastic elastomer having a specific structure and a diacetal compound having a specific structure.

Olefin-based thermoplastic elastomer The thermoplastic elastomer of the present invention is an olefin-based thermoplastic elastomer, preferably 60 to 99% by mass, more preferably 70 to 97% by mass, based on the total mass of the thermoplastic elastomer. It is a copolymer composed of a propylene-inducing unit, an ethylene-inducing unit of 1 to 40% by mass, more preferably 3 to 30% by mass, and / or an α-olefin inducing unit having 4 to 10 carbon atoms.

Specific examples of the α-olefin that forms the basis of the α-olefin inducing unit include 1-butene, isobutene, 1-pentene, 1-hexene, 3-methyl-1-pentene, and 4-methyl-1-pentene. , 1-heptene, 1-octene, 1-nonen, 1-decene and the like, and among them, preferable α-olefins include 1-butene and 4-methyl-1-pentene. These α-olefins may be used alone or in combination of two or more.

Further, it is recommended that the thermoplastic elastomer of the present invention preferably has a heat of fusion measured by differential scanning calorimetry of 50 J / g or less, more preferably 30 J / g or less. The amount of heat of fusion is a numerical value that serves as a guideline for crystallinity, and within the above range, it indicates that the elastomer has low crystallinity to the extent that it can impart flexibility, which is the original characteristic of the elastomer.

The measurement in the differential scanning calorimetry can be performed under general conditions using a general-purpose analyzer. Specifically, for example, a measurement sample (sample weight = about 5 mg to 10 mg) is precisely weighed using a differential scanning calorimetry device (trade name “DSC8500”) manufactured by PerkinElmer, and the temperature is 10 ° C to 10 ° C /. The temperature is raised to 220 ° C. at a heating rate of min, and the melting peak and the amount of heat thereof when the sample is melted can be measured.

Further, it is recommended that the maximum melting peak temperature of the thermoplastic elastomer of the present invention measured by differential scanning calorimetry is preferably 115 ° C. or lower, or that the melting peak temperature is not observed by the measurement of differential scanning calorimetry. Will be done. When the melting peak temperature is within the above range, the characteristics of the thermoplastic elastomer can be maximized.

The measurement in the differential scanning calorimetry can be performed under general conditions using a general-purpose analyzer as in the case of the heat of fusion.

The olefin-based thermoplastic elastomer of the present invention can be obtained by copolymerizing propylene with ethylene and / or an α-olefin having 4 to 10 carbon atoms under normal conditions in the presence of a known production method, for example, a metallocene catalyst. Be done. Specifically, it can be produced by using the production method described in JP-A-2007-2266.

Further, as the olefin-based thermoplastic elastomer of the present invention, a commercially available olefin-based thermoplastic elastomer that exhibits the effect of the present invention, that is, that meets the scope of the present invention can be used as it is. Examples of such commercially available olefin-based thermoplastic elastomers include ExxonMobil's Vistamaxx series, Dow Chemical's Versify series, Mitsui Chemicals'Tafmer series and Notio series, and Sumitomo Chemical's Tafthren. Products such as series can be mentioned.

［式（１）中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシ基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシカルボニル基又はハロゲン原子を示す。Ｒ^３は、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数２～４のアルケニル基又は直鎖状若しくは分岐鎖状の炭素数１～４のヒドロキシアルキル基を示す。ｍ及びｎは、それぞれ１～５の整数を示す。ｐは０又は１を示す。２つのＲ^１は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。２つのＲ^２基は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。］ Diasetal compound The diacetal compound of the present invention is a diacetal compound represented by the following general formula (1).

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. The two R1s may be bonded to ^each other to form a tetralin ring with the benzene ring to which they are bonded. The two ^R2 groups may be bonded to each other to form a tetralin ring with the benzene ring to which they are bonded. ]

Among the diacetal compounds, as more preferable compounds, for example, R ¹ and R ² in the above general formula (1) are the same or different, and are a methyl group or an ethyl group, and R ³ is a hydrogen atom. Yes, m and n are integers of 1 or 2, p is 1, and R ¹ and R ² in the above general formula (1) are propyl groups or propyloxy groups, and R ³ is. Examples thereof include compounds which are propyl groups or propenyl groups, in which m and n are 1, and p is 1.

Further, the following compounds can also be exemplified as further preferable compounds; in the above general formula (1), R ¹ and R ² are propyl groups or propyloxy groups, and R ³ is a propyl group or propenyl. A compound that is a group, m and n are 1, and p is 1.

Specific embodiments of the diacetal compound include the following compounds. 1,3: 2,4-di-O-benzylidene-D-sorbitol, 1,3: 2,4-bis-O- (methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O -(O-Methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-) Methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (ethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-ethylbenzylidene) -D- Sorbitol, 1,3: 2,4-bis-O- (m-ethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -D-sorbitol, 1, 3: 2,4-bis-O- (o-isopropylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-isopropylbenzylidene) -D-sorbitol, 1,3: 2, 4-bis-O- (p-isopropylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (one-propylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (mn-propylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-propylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (one-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (mn-butylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (pn-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (ot-butylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (mt-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pt-butylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 3'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis- O- (2', 4'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 5'-dimethylbenzylidene) -D-sorbitol, 1,3: 2, 4-bis-O- (2', 6'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3', 4'-dimethylbenzyl) Liden) -D-sorbitol, 1,3: 2,4-bis-O- (3', 5'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 3'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 4'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 5'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2', 6'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4- Bis-O- (3', 4'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3', 5'-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-Bis-O- (2', 4', 5'-trimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3', 4', 5'-trimethylbendylidene) ) -D-sorbitol, 1,3: 2,4-bis-O- (2', 4', 5'-triethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3) ', 4', 5'-triethylbenzitol) -D-sorbitol, 1,3: 2,4-bis-O- (o-methoxybenzylidene) -D-sorbitol, 1,3: 2,4-bis-O -(M-Meth benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-methoxybenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-) Ethoxybenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-ethoxybenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethoxybenzylidene)- D-sorbitol, 1,3: 2,4-bis-O- (o-isopropoxybenziliden) -D-sorbitol, 1,3: 2,4-bis-O- (m-isopropoxybenziliden) -D- Sorbitol, 1,3: 2,4-bis-O- (p-isopropoxybenziliden) -D-sorbitol, 1,3: 2,4-bis-O- (one-propoxybenziliden) -D-sorbitol , 1,3: 2,4-bis-O- (mn-propoxybenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-propoxybenzylidene) -D-sorbitol , 1,3: 2,4-bis-O- (o-methoxycarbonylbenzylene) -D-sorbitol, 1,3: 2,4-bis-O- (m) -Methoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-methoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-ethoxy) CarbonylBenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-ethoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethoxycarbonylbenzylidene) ) -D-Sorbitol, 1,3: 2,4-bis-O- (o-isopropoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-isopropoxycarbonylbenzylidene) ) -D-Sorbitol, 1,3: 2,4-bis-O- (p-isopropoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (one-propoxycarbonyl) Benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (mn-propoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-) Propoxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-fluorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-fluorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-fluorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-chlorobenzylidene) -D-sorbitol , 1,3: 2,4-bis-O- (m-chlorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-chlorobenzylidene) -D-sorbitol, 1,3 : 2,4-bis-O- (o-bromobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-bromobenzylidene) -D-sorbitol, 1,3: 2,4 -Bis-O- (p-bromobenzylidene) -D-sorbitol, 1,3-O-benzylidene-2,4-O- (p-methylbenzylidene) -D-sorbitol, 1,3-O- (p-) Methylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (p-ethylbenzylidene) -D-sorbitol, 1,3-O- (p-) Ethylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (p-chlorobenzylidene) -D-sorbito Le, 1,3-O- (p-chlorobenziliden) -2,4-O-benziliden-D-sorbitol, 1,3-O-benziliden-2,4-O- (2', 4'-dimethylbenziliden) ) -D-Sorbitol, 1,3-O- (2', 4'-Dimethylbenziliden) -2,4-O-Benzilidene-D-Sorbitol, 1,3-O-Benzilidene-2,4-O- ( 3', 4'-dimethylbenzylidene) -D-sorbitol, 1,3-O- (3', 4'-dimethylbenziliden) -2,4-O-benziliden-D-sorbitol, 1,3-O- ( p-Methylbenzylidene) -2,4-O- (p-ethylbendylidene) -D-sorbitol, 1,3-O- (p-ethylbendylidene) -2,4-O- (p-methylbenziliden) -D -Sorbitol, 1,3-O- (p-methylbenziliden) -2,4-O- (3', 4'-dimethylbenziliden) -D-Sorbitol, 1,3-O- (3', 4'- Dimethylbenziliden) -2,4-O-p-methylbenziliden-D-sorbitol, 1,3-O- (p-ethylbendiliden) -2,4-O- (3', 4'-dimethylbenziliden) -D -Sorbitol, 1,3-O- (3', 4'-dimethylbenziliden) -2,4-O-p-ethylbendylidene-D-sorbitol, 1,3-O- (p-methylbenziliden) -2, 4-O- (p-chlorobenziliden) -D-sorbitol, 1,3-O- (p-chlorobenziliden) -2,4-O- (p-methylbenziliden) -D-sorbitol, 1,3: 2 , 4-bis-O- (3', 4'-dichlorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O-benziliden-1-methylsorbitol, 1,3: 2,4-bis -O- (p-Methylbenziliden) -1-methylsorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O -(Pn-propylbenzylene) -1-methylsorbitol, 1,3: 2,4-bis-O- (2', 3'-dimethylbenzylidene) -1-methylsorbitol, 1,3: 2,4 -Bis-O- (2', 4'-dimethylbenziliden) -1-methylsorbitol, 1,3: 2,4-bis-O- (2', 5'-dimethylbenziliden) -1-methylsorbitol, 1 , 3: 2,4-Bis-O- (2', 6'-dimethylbenzylidene) -1-me Tyrsorbitol, 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (3', 5'- Dimethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (2', 3'-diethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O-( 2', 4'-diethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (2', 5'-diethylbenziliden) -1-methylsorbitol, 1,3: 2,4 -Bis-O- (2', 6'-diethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (3', 4'-diethylbenzylidene) -1-methylsorbitol, 1 , 3: 2,4-bis-O- (3', 5'-diethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-methoxybenziliden) ) -1-Methylsorbitol, 1,3: 2,4-bis-O- (3', 4'-dichlorobenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (p-) Methylcarbonylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-fluorobenzylidene) -1-methylsorbitol, 1,3: 2,4-bis- O- (3'-bromo-4'-ethylbenzylidene) -1-methylsorbitol, 1,3: 2,4-bis-O-benziliden-1-ethylsorbitol, 1,3: 2,4-bis-O -(P-Methylbenziliden) -1-ethylsorbitol, 1,3: 2,4-bis-O- (p-ethylbenziliden) -1-ethylsorbitol, 1,3: 2,4-bis-O- ( pn-propylbenziliden) -1-ethylsorbitol, 1,3: 2,4-bis-O- (2', 3'-dimethylbenziliden) -1-ethylsorbitol, 1,3: 2,4-bis -O- (2', 4'-dimethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (2', 5'-dimethylbenziliden) -1-ethylsorbitol, 1,3 : 2,4-bis-O- (2', 6'-dimethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (3', 4'-dimethylbenziliden) -1- Ethylsorbitol, 1,3: 2,4-bis-O- (3', 5'-dimethylbenziliden) -1-d Tyrsorbitol, 1,3: 2,4-bis-O- (2', 3'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (2', 4'- Diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (2', 5'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (2', 5'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- 2', 6'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (3', 4'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4 -Bis-O- (3', 5'-diethylbenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-methoxybenzylidene) -1-ethylsorbitol , 1,3: 2,4-bis-O- (3', 4'-dichlorobenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (p-methoxycarbonylbenzidene) -1 -Ethylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-fluorobenzylidene) -1-ethylsorbitol, 1,3: 2,4-bis-O- (3'- Bromo-4'-ethylbenzylene) -1-ethylsorbitol, 1,3: 2,4-bis-O-benzylidene-1-n-propylsorbitol, 1,3: 2,4-bis-O- (p-) Methylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- ( pn-propylbenziliden) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (2', 3'-dimethylbenzylidene) -1-n-propylsorbitol, 1,3: 2 , 4-Bis-O- (2', 4'-Dimethylbenziliden) -1-n-propylsorbitol, 1,3: 2,4-Bis-O- (2', 5'-Dimethylbenziliden) -1- n-propylsorbitol, 1,3: 2,4-bis-O- (2', 6'-dimethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3') , 4'-Dimethylbenziliden) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3', 5'-dimethylbenzylidene) -1-n-propylsorbitol, 1,3: 2 , 4-Bis-O- (2', 3'-diethylbenzylidene) -1-n-propylsorbitol, 1, 3: 2,4-bis-O- (2', 4'-diethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (2', 5'-diethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (2', 6'-diethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3', 4'-diethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3', 5'-diethylbenzylidene) -1-n-propylsorbitol, 1, 3: 2,4-bis-O- (3'-methyl-4'-methoxybenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3', 4'-dichloro Benzilidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (p-methoxycarbonylbenziliden) -1-n-propylsorbitol, 1,3: 2,4-bis-O- ( p-ethoxycarbonylbenzylene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (p-propoxycarbonylbenzylene) -1-n-propylsorbitol, 1,3-O- (p-) n-propylbenziliden) -2,4-O- (p-propoxybenziliden) -1-n-propylsorbitol, 1,3-O- (p-propoxybenziliden) -2,4-O- (pn-) Propylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-fluorobenziliden) -1-n-propylsorbitol, 1,3: 2,4 -Bis-O- (3'-bromo-4'-ethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (pn-propylbenziliden) -1-propenylsorbitol , 1,3: 2,4-bis-O- (p-ethoxycarbonylbenzylidene) -1-propenylsorbitol, 1,3: 2,4-bis-O- (p-propoxycarbonylbenziliden) -1-propenylsorbitol , 1,3-O- (pn-propylbenziliden) -2,4-O- (p-propoxybenzylidene) -1-propenyl sorbitol, 1,3-O- (p-propoxybenzylidene) -2,4 -O- (pn-Propylbenzylidene) -1-propenylsorbitol, 1,3: 2,4-bis-O-benzylidene-1-allylsorbitol, 1,3: 2,4-bis-O- ( p-Methylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (p-) n-propylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (2', 3'-dimethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O -(2', 4'-dimethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (2', 5'-dimethylbenzylidene) -1-allyl sorbitol, 1,3: 2 , 4-Bis-O- (2', 6'-dimethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -1-allyl sorbitol , 1,3: 2,4-bis-O- (3', 5'-dimethylbenzylidene) -1-allylsorbitol, 1,3: 2,4-bis-O- (2', 3'-diethylbenzylidene) ) -1-Allylsorbitol, 1,3: 2,4-bis-O- (2', 4'-diethylbenzylidene) -1-allylsorbitol, 1,3: 2,4-bis-O- (2') , 5'-diethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (2', 6'-diethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis -O- (3', 4'-diethylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (p-ethoxycarbonylbenzylidene) -1-allyl sorbitol, 1,3: 2, 4-Bis-O- (p-propoxycarbonylbenzylidene) -1-allyl sorbitol, 1,3-O- (pn-propylbenzylidene) -2,4-O- (p-propoxybenzylidene) -1-allyl Sorbitol, 1,3-O- (p-propoxybenzylidene) -2,4-O- (pn-propylbenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (3' , 5'-diethylbenzylidene) -1-n-propylsorbitol, 1,3: 2,4-bis-O- (3'-methyl-4'-methoxybenzylidene) -1-allylsorbitol, 1,3: 2 , 4-bis-O- (3', 4'-dichlorobenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (p-methoxycarbonylbenzylidene) -1-allyl sorbitol, 1, 3: 2,4-bis-O- (3'-methyl-) Examples thereof include 4'-fluorobenzylidene) -1-allyl sorbitol, 1,3: 2,4-bis-O- (3'-bromo-4'-ethylbenzylidene) -1-allyl sorbitol and the like.

Particularly preferred embodiments are 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -D. -Sorbitol, 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-chlorobenzylidene) -D -Sorbitol, 1,3: 2,4-bis-O- (pn-propylbenzylidene) -1-propylsorbitol can be mentioned.

Further, the diacetal compound of the above specific embodiment may be used alone, but from the viewpoint of other performance, for example, low temperature processability, two or more kinds of diacetal compounds may be used in combination or in a premixed manner. May be good.

When used in combination or in a mixed system, for example, 1,3: 2,4-di-O-benzylidene-D-sorbitol and 1,3: 2,4-bis-O- (p-methylbenziliden) -D- Combination of sorbitol and 1,3: 2,4-bis-O- (p-ethylbenzylidene) -D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzidene)- Combination of D-sorbitol, combination of 1,3: 2,4-dibenzylidene-D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-chlorobenzylidene) -D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3', 4'-dichlorobenzylidene) -D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzidene)- An example is a combination of D-sorbitol.

The production method described for the diacetal compound is described in, for example, Japanese Patent Application Laid-Open No. 48-43748, JP-A-53-5165, JP-A-57-185287, JP-A-2-231488, and the like. It can be easily manufactured by using or the like. Also, those currently on the market as crystal nucleating agents for polyolefins, such as Gelol D, Gelol MD, Gelol DXR of Shin Nihon Rika Co., Ltd., Mirad 3988, Mirad NX8000, GCH TECHNOLORY of Milliken (USA) (China). ) SIPAX NA-2 or the like may be used as it is.

The content of the diacetal compound in the olefin-based thermoplastic elastomer composition of the present invention is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the thermoplastic elastomer, preferably 0.05 to 1. It is recommended to have 0 parts by mass. When the content of the diacetal compound is within the above range, the effect of improving transparency, which is a feature of the present invention, can be maximized.

Other Additives The olefin-based thermoplastic elastomer composition of the present invention is generally a thermoplastic elastomer other than the diacetal compound of the present invention, depending on the purpose of use and its use, as long as the effects of the present invention are not impaired. Other additives used in the above, for example, softeners used in ordinary rubbers and additives for polyolefin resins generally used in polyolefin resins may be contained.

Specific examples of the softener for rubber include petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt, and vaseline; Coultal softeners; Fatty oil softeners such as castor oil, flaxseed oil, rapeseed oil, soybean oil, palm oil; tall oil; sub, (factis); waxes such as beeswax, carnauba wax, lanolin; , Palmitic acid, stearic acid, barium stearate, calcium stearate, zinc laurate and other fatty acids and fatty acid salts; naphthenic acid; pine oil, rosin or derivatives thereof; terpene resin, petroleum resin, kumaron inden resin, atactic polypropylene, etc. Synthetic polymer substances; ester-based softeners such as dioctylphthalate, dioctyl adipate, dioctyl sebacate; microcrystallin wax, liquid polybutadiene, modified liquid polybutadiene, liquid polyisoprene, terminal-modified polyisoprene, hydrogenated terminal-modified polyisoprene, liquid Examples thereof include thiocol and hydrocarbon-based synthetic lubricating oils. When the softening agent is blended, the blending amount is generally, for example, about 20 to 100 parts by mass with respect to 100 parts by mass of the thermoplastic elastomer.

Examples of the additives for polyolefin resins include various additives described in "Handbook of Additives on the Positive List" (September 2004) edited by the Polyolefin Hygiene Council. Specifically, nucleating agents (phosphate ester metal salts, carboxylic acid metal salts, etc.) other than diacetal compounds, fluorescent whitening agents (2,5-thiophendiyl (5-t-butyl-1,3-benzoxa)). Zol), 4,4'-bis (benzoxazole-2-yl) stylben, etc.), antioxidants, stabilizers (metal compounds, epoxy compounds, nitrogen compounds, phosphorus compounds, sulfur compounds, etc.), ultraviolet absorbers (benzophenone) Systems compounds, benzotriazole compounds, etc.), surfactants, lubricants (aliphatic hydrocarbons such as paraffin and wax, higher fatty acids with 8 to 22 carbon atoms, higher fatty acid metal (Al, Ca) salts with 8 to 22 carbon atoms). , Higher aliphatic alcohol having 8 to 22 carbon atoms, polyglycol, ester of higher fatty acid having 4 to 22 carbon atoms and aliphatic monovalent alcohol having 4 to 18 carbon atoms, higher fatty acid amide having 8 to 22 carbon atoms, silicone. Oils, rosin derivatives, etc.), fillers (talc, hydrotalcite, mica, zeolite, pearlite, diatomaceous earth, calcium carbonate, glass fiber, etc.), foaming agents, foaming aids, polymer additives, plasticizers (dialkylphthalate, dialkyl) Hexahydrophthalate, etc.), cross-linking agent, cross-linking accelerator, antistatic agent, flame retardant, dispersant, organic-inorganic pigment (indigo compound, phthalocyanine-based compound, anthraquinone-based compound, ultramarine compound, cobalt aluminate compound, etc.), Various additives such as processing aids and other nucleating agents are exemplified.

When these additives for polyolefin resins are used, the amount thereof may be used within the range normally used as long as the effects of the present invention are not impaired. For example, with respect to 100 parts by mass of the polyolefin resin. It is generally used in an amount of about 0.0001 to 100 parts by mass, more preferably about 0.001 to 50 parts by mass.

Examples of the antioxidant include phenol-based antioxidants, phosphite-based antioxidants, sulfur-based antioxidants, and the like, and specific antioxidants include 2,6-di-tert-butylphenol. , Tetrax [Methylene-3- (3,5-tert-butyl-4-hydroxyphenol) propionate] Phenolic antioxidants such as methane and 2-hydroxy-4-methoxybenzophenone, alkyl disulfides, thiodipropionic acid esters, Sulfur-based antioxidants such as benzothiazole, trisnonylphenylphosphite, diphenylisodecylphosphite, triphenylphosphite, tris (2,4-di-tert-butylphenyl) phosphite, 3,9-bis (2) , 6-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] Subphosphate ester-based antioxidants such as undecane are exemplified. Among them, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, which is a phenolic antioxidant, and tris (2,) which is a phosphite ester-based antioxidant. 4-Di-tert-butylphenyl) phosphite, 3,9-bis (2,6-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5, 5] Undecan is especially recommended.

The method for producing the olefin-based thermoplastic elastomer composition of the present invention is not particularly limited as long as the effect of the present invention is exhibited, and for example, the olefin-based thermoplastic elastomer of the present invention, the diacetal compound, and if necessary, others. Examples thereof include a method in which the additive of the above is melt-mixed using a general-purpose melt-mixer, a single-screw extruder, a twin-screw extruder, etc., then cooled and solidified, and cut into a pellet-like shape. Further, a method of uniformly dry-blending each component in advance before melting and mixing is also mentioned as an effective method. Further, when the temperature at the time of melting and mixing is equal to or higher than the temperature at which the total amount of the compounded diacetal compound is dissolved in the olefin-based thermoplastic elastomer, the effect of the present invention can be further exhibited.

［式（１）中、Ｒ^１及びＲ^２は、同一又は異なって、それぞれ、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシ基、直鎖状若しくは分岐鎖状の炭素数１～４のアルコキシカルボニル基又はハロゲン原子を示す。Ｒ^３は、水素原子、直鎖状若しくは分岐鎖状の炭素数１～４のアルキル基、直鎖状若しくは分岐鎖状の炭素数２～４のアルケニル基又は直鎖状若しくは分岐鎖状の炭素数１～４のヒドロキシアルキル基を示す。ｍ及びｎは、それぞれ１～５の整数を示す。ｐは０又は１を示す。２つのＲ^１は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。２つのＲ^２基は互いに結合してそれらが結合するベンゼン環と共にテトラリン環を形成していてもよい。］
なお、本発明の透明性の改善方法に係る各構成の説明は、上記＜オレフィン系の熱可塑性エラストマー組成物＞に記載した構成の説明と同義である。 <How to improve transparency>
The method for improving transparency of the present invention is characterized by containing 0.05 to 5.0 parts by mass of a diacetal compound with respect to 100 parts by mass of an olefin-based thermoplastic elastomer, and further, the olefin-based thermoplastic elastomer is contained. However, 60 to 99% by mass of the propylene inductive unit with respect to the total mass of the thermoplastic elastomer, 1 to 40% by mass of the ethylene inductive unit with respect to the total mass of the thermoplastic elastomer, and / or 4 to 10 carbon atoms. It is a copolymer composed of the α-olefin inducing unit of the above, and further, the heat of fusion measured by the differential scanning calorific value analysis is 50 J / g or less, and the diacetal compound is a compound represented by the following general formula (1). It is characterized by being.

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. The two R1s may be bonded to ^each other to form a tetralin ring with the benzene ring to which they are bonded. The two ^R2 groups may be bonded to each other to form a tetralin ring with the benzene ring to which they are bonded. ]
The description of each configuration according to the method for improving transparency of the present invention is synonymous with the description of the configuration described in the above <olefin-based thermoplastic elastomer composition>.

<Olefin-based thermoplastic elastomer molded product>
The olefin-based thermoplastic elastomer molded product of the present invention can be obtained by molding using the above-mentioned olefin-based thermoplastic elastomer composition of the present invention according to a conventional molding method. The molding method is not particularly limited as long as the effect of the present invention is exhibited, and any conventionally known molding method such as injection molding, extrusion molding, blow molding, pneumatic molding, rotary molding, and film molding can be adopted.

The olefin-based thermoplastic elastomer molded product thus obtained is extremely excellent in optical properties such as transparency and mechanical properties such as flexibility and strength. It is very useful in various applications such as parts, machine parts, and daily miscellaneous goods. In particular, it has transparency that cannot be obtained with general thermoplastic elastomers, and medical materials, coating materials, packaging materials, toys, etc. that require transparency from the viewpoint of visibility and design. It is very useful in the applications of.

Examples are shown below and the present invention will be described in more detail, but the present invention is not limited to these examples. The methods for measuring each characteristic described in the examples and the thermoplastic elastomers and diacetal compounds used in the examples are as follows.

[Characteristics of thermoplastic elastomer]
(1) Heat quantity of melting and maximum melting peak temperature Using a differential scanning calorimetry device (trade name "DSC8500") manufactured by PerkinElmer, a measurement sample having a weight between 5 mg and 10 mg is precisely weighed and 10 The temperature was raised from ° C. to 220 ° C. at a heating rate of 10 ° C./min, and the melting peak and the amount of heat thereof when the sample melted were measured.

[Optical properties of thermoplastic elastomer molded product]
(2) Transparency evaluation: Measurement of haze value The haze value was measured by a method according to JIS K7136 (2000) using a haze meter manufactured by Toyo Seiki Seisakusho. As the evaluation sample, a thermoplastic elastomer molded product having a thickness of 1 mm was used. The smaller the obtained haze value, the better the transparency. When the haze value is 20% or less, preferably 10% or less, it can be said that the transparency is excellent enough to obtain practically sufficient visibility.

[Mechanical properties of thermoplastic elastomer molded product]
(3) Tensile test: Measurement of tensile elastic modulus, tensile yield stress, and tensile fracture strain According to JIS K7161-1 (2014) using a universal material tester manufactured by Instron (model name "Instron 5565"). The tensile test was carried out by the above method, and the tensile elastic modulus, tensile yield stress, and tensile fracture strain were measured. The test environment, test piece shape, and test conditions are as follows.
Measurement temperature: 23 ° C., sample length (distance between chucks): 10 mm, test speed: 50 mm / min.
Tensile test piece: An injection-molded product having a thickness of 0.5 mm was cut into strips having a width of 7 mm and a length of 10 mm in the resin flow direction (MD direction) and vertical direction (TD direction).

Olefin-based thermoplastic elastomer elastomer A: propylene / ethylene copolymer, trade name Vistamaxx3588FL, manufactured by Exxon Mobile, content of ethylene induction unit: 4% by mass, MFR (230 ° C, load 21.18N): 8g / 10 minutes, heat of fusion: 29.3 J / g, maximum melting peak temperature: 106.8 ° C.
Elastomer B: propylene / ethylene copolymer, trade name Vistamaxx6102, manufactured by Exxon Mobile, content of ethylene induction unit: 16% by mass, MFR (230 ° C, load 21.18N): 3g / 10 minutes, heat of melting : 15 J / g or less, maximum melting peak temperature: not observed.

Diacetal compound / compound a: 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol compound b: 1,3: 2,4-bis-O- (3', 4') -Dimethylbenzylidene) -D-sorbitol compound c: 1,3: 2,4-bis-O- (pn-propylbenziliden) -1-n-propylsorbitol compound d: 1,3: 2,4 7: 3 (mass ratio) of -bis-O- (p-ethylbenzylidene) -D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol Mixture of

[Example 1]
ExxonMobil's Vistamaxx3588FL (elastomer A) 100 parts by mass as an olefin-based thermoplastic elastomer and 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol (compound a) as a diacetal compound. ) 0.05 parts by mass were mixed and then melt-mixed at a barrel temperature of 220 ° C. using a twin-screw extruder (KZW15TW-45MG-NH manufactured by Technobel Co., Ltd.). The extruded strands were cooled and cut with a pelletizer to obtain pelletized olefin-based thermoplastic elastomer composition of the present invention.

Subsequently, using the olefin-based thermoplastic elastomer composition obtained above, an injection molding machine (NS40-5A manufactured by Nissei Plastic Industry Co., Ltd.) was used to inject molding temperature (heating temperature) 220 ° C. and mold temperature (mold temperature (NS40-5A)). Molding was performed under the condition of cooling temperature) 40 ° C. to obtain a thermoplastic elastomer molded product having a thickness of 0.5 mm and 1.0 mm.

Using the molded product obtained above as an evaluation sample, the haze value was measured by the method described in (2) above, and the obtained results are shown in Table 1. Further, according to the method described in (3) above, a strip-shaped test piece is cut out from the molded body, a tensile test is performed, and the tensile elastic modulus, the tensile yield stress, and the tensile fracture strain are obtained from the test results, and Table 1 shows. Indicated.

[Example 2]
The same procedure as in Example 1 was carried out except that the blending amount of the diacetal compound was changed to 0.1 part by mass to prepare a composition and a molded product, and the obtained molded product was used in the same manner as in Example 1. The tests were performed and the results of the obtained haze value, tensile modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Example 3]
The same procedure as in Example 1 was carried out except that the blending amount of the diacetal compound was changed to 0.2 parts by mass to prepare a composition and a molded product, and the obtained molded product was used in the same manner as in Example 1. The tests were performed and the results of the obtained haze value, tensile modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Example 4]
As a diacetal compound, 1,3: 2,4-bis-O- (3', 4) instead of 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol (compound a) The same procedure as in Example 2 was carried out except that'-dimethylbenzylidene) -D-sorbitol (compound b) was used to prepare a composition and a molded product, and the obtained molded product was used in the same manner as in Example 2. The results of the obtained haze value, tensile elastic modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Example 5]
As a diacetal compound, 1,3: 2,4-bis-O- (pn-) instead of 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol (compound a) The same procedure as in Example 2 was carried out except that propylbenzylidene) -1-n-propylsorbitol (compound c) was used to prepare a composition and a molded product, and the obtained molded product was used as the second embodiment. The same test was performed, and the results of the obtained haze value, tensile modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Example 6]
The same procedure as in Example 5 was carried out except that the blending amount of the diacetal compound was changed to 0.2 parts by mass to prepare a composition and a molded product, and the obtained molded product was used in the same manner as in Example 5. The tests were performed and the results of the obtained haze value, tensile modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Example 7]
As a diacetal compound, 1,3: 2,4-bis-O- (p-ethylbenzylidene) instead of 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol (compound a) )-D-sorbitol and 1,3: 2,4-bis-O- (3', 4'-dimethylbenzylidene) -D-sorbitol 7: 3 (mass ratio) mixture (compound d) was used. Is carried out in the same manner as in Example 2, the composition and the molded product are prepared, and the obtained molded product is used in the same test as in Example 2, and the obtained haze value, tensile elastic modulus and tensile yield are obtained. The results of stress and tensile fracture strain are shown in Table 1.

[Example 8]
The composition and the molded product were prepared in the same manner as in Example 2 except that Vistamaxx6102 (elastomer B) manufactured by Exxon Mobile Co., Ltd. was used instead of Vistamaxx3588FL (elastomer A) as the olefin-based thermoplastic elastomer. The same test as in Example 2 was carried out using the obtained molded product, and the results of the obtained haze value, tensile elastic modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Comparative Example 1]
The same procedure as in Example 1 was carried out without blending the diacetal compound to prepare a composition and a molded product, and the obtained molded product was used in the same test as in Example 1 to obtain a haze value and tension. The results of elastic modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

[Comparative Example 2]
The same procedure as in Example 8 was carried out without blending the diacetal compound to prepare a composition and a molded product, and the obtained molded product was used in the same test as in Example 8 to obtain the haze value and tensile strength. The results of elastic modulus, tensile yield stress and tensile fracture strain are shown in Table 1.

From the results in Table 1, it can be seen that the haze value is greatly reduced and the transparency is improved by using the thermoplastic elastomer composition of the present invention. Further, regarding the mechanical properties, no deterioration due to the use of the composition of the present invention was observed. That is, it can be seen that the thermoplastic elastomer composition of the present invention can significantly improve the transparency while maintaining the mechanical properties of the original thermoplastic elastomer.

The method for improving the transparency of a thermoplastic elastomer and the olefin-based thermoplastic elastomer composition of the present invention exert a great effect on improving the transparency of a thermoplastic elastomer, and can be conventionally used by using the method or composition. Olefin-based thermoplastic elastomers can also be used in medical applications, covering materials, packaging materials, toys, etc., where transparency is required from the viewpoint of visibility and design, which were difficult. In addition, by taking advantage of the features of olefin-based elastomers such as light weight and recyclability, it can be used as molded products, sheets, and films for various purposes such as automobile parts, electrical parts, machine parts, and daily miscellaneous goods. can.

Claims (7)

An olefin-based thermoplastic elastomer composition having excellent transparency.
The olefin-based thermoplastic elastomer contains 60 to 99% by mass of propylene-inducing units with respect to the total mass of the thermoplastic elastomer, and 1 to 40% by mass of ethylene-inducing units with respect to the total mass of the thermoplastic elastomer. Alternatively, it is a copolymer composed of an α-olefin inducing unit having 4 to 10 carbon atoms, and
The heat of fusion measured by differential scanning calorimetry has crystallinity of 15 J / g or more and 50 J / g or less.
An olefin-based thermoplastic elastomer composition containing 0.05 to 5.0 parts by mass of a diacetal compound represented by the following general formula (1) with respect to 100 parts by mass of the olefin-based thermoplastic elastomer. ..

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. The olefin-based thermoplastic elastomer composition according to claim 1, wherein the maximum melting peak temperature measured by differential scanning calorimetry is 115 ° C. or lower, or no melting peak temperature is observed by differential scanning calorimetry. In the general formula (1), the diacetal compound has R ¹ and R ² which are the same or different, a methyl group or an ethyl group, R ³ is a hydrogen atom, and m and n are 1 or 2. The olefin-based thermoplastic elastomer composition according to claim 1 or 2 , which is an integer and p is 1. In the diacetal compound, in the above general formula (1), R ¹ and R ² are the same or different, a propyl group or a propoxy group, R ³ is a propyl group or a propenyl group, and m and n are 1. The olefin-based thermoplastic elastomer composition according to claim 1 or 2 , wherein p is 1. The olefin-based thermoplastic elastomer composition according to any one of claims 1 to 4 , wherein the content of the diacetal compound is 0.05 to 1.0 part by mass with respect to 100 parts by mass of the thermoplastic elastomer. A thermoplastic elastomer molded product having excellent transparency, using the olefin-based thermoplastic elastomer composition according to any one of claims 1 to 5 as a raw material. A method for improving the transparency of thermoplastic elastomers.
To contain 0.05 to 5.0 parts by mass of the diacetal compound with respect to 100 parts by mass of the olefin-based thermoplastic elastomer, further,
The olefin-based thermoplastic elastomer contains 60 to 99% by mass of propylene-inducing units with respect to the total mass of the thermoplastic elastomer, and 1 to 40% by mass of ethylene-inducing units with respect to the total mass of the thermoplastic elastomer. / Or a copolymer composed of α-olefin-inducing units having 4 to 10 carbon atoms, further having a crystallinity of 15 J / g or more and 50 J / g or less in melting heat measured by differential scanning calorific value analysis, and ,
An improvement method, wherein the diacetal compound is a compound represented by the following general formula (1).

[In the formula (1), R ¹ and R ² are the same or different, respectively, a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a linear or branched carbon. It indicates an alkoxy group having the number of 1 to 4, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, or a halogen atom. R3 is a hydrogen atom ^, a linear or branched-chain alkyl group having 1 to 4 carbon atoms, a linear or branched-chain alkenyl group having 2 to 4 carbon atoms, or a linear or branched-chain carbon. The number 1 to 4 hydroxyalkyl groups are shown. m and n represent integers of 1 to 5, respectively. p indicates 0 or 1. ]