JP7194426B2 - dynamically crosslinked elastomer - Google Patents

Description

The present invention relates to novel elastomers, which are dynamically crosslinked elastomers, processes for their preparation and compositions containing them.

Natural rubber is a kind of elastomer whose main component is cis-1,4-polyisoprene with a molecular weight of about 1,000 to several million. Natural rubber has a three-dimensional network structure when vulcanized, and exhibits high impact resilience, so it is used in various products such as tires. On the other hand, diene polymers such as isoprene rubber and butadiene rubber, which are obtained by polymerizing monomers having a 1,3-butadiene structure such as isoprene and 1,3-butadiene, are also called synthetic rubbers. It has advantages such as being easy to process because it is homogeneous and its molecular weight is adjusted. It is also used in various products as an alternative raw material rubber to natural rubber.

In order to impart additional properties to natural rubber and isoprene rubber containing cis-1,4-isoprene units, modifications thereof have been investigated. Such modifications include, for example, hydrogenation, halogenation, hydroxylation or epoxidation of the double bond site of the cis-1,4-isoprene unit. Among others, epoxidation of natural rubber and isoprene rubber is known to improve oil resistance, organic solvent resistance, air permeability, damping properties, friction resistance, and the like. In addition, various methods for synthesizing polymers in which a part of the epoxy groups of such epoxidized natural (synthetic) rubber is hydrolyzed to introduce a diol (vicinal diol) structure into the main chain, and methods for improving the thermal stability and adhesive strength thereof. Improvements have been reported (see, for example, Non-Patent Documents 1-3).

Furthermore, in recent years, it has been reported that olefin polymers and diene polymers are obtained by ring-opening metathesis polymerization reactions of cyclic olefins, and novel polymer materials using such reactions have been reported (e.g., Patent Document 1 and Non-Patent Documents 4).

U.S. Patent Publication No. 6023923

Polymer, Vol. 38, No. 8, pp. 1953-1956, 1997 Advanced Materials Research, Vol.747, pp.493-496, 2013 Sains Malaysian, Vol.46, No.3, pp.485-491, 2017 Polymer Chemistry, Vol. 5, pp. 3507-3532, 2014

The present inventors have searched for novel diene-based polymers obtained by ring-opening metathesis polymerization reaction of cyclic olefins and their properties as elastomers. As a result, by introducing a vicinal diol structure into a diene-based polymer without relying on ring-opening of the epoxy groups in the main chain, it imparts excellent properties such as high elasticity, toughness, recyclability, and self-healing properties. The inventors have found that it is possible to do so, and have completed the present invention.

The present invention is as follows.

で表されるビシナルジオール単位、および式（２）：

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるブタ－１－エン－１，４－ジイル単位を含むが、但し、式（３）：

（式中、Ｒは、上記と同義である）
で表されるエポキシ単位を５mol％以上含まない、エラストマー。
［２］ 下記式（Ｉ）：

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるエラストマー。 [1] Formula (1):

and a vicinal diol unit represented by the formula (2):

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
but-1-ene-1,4-diyl unit represented by the proviso that formula (3):

(Wherein, R has the same definition as above)
An elastomer containing no more than 5 mol% of the epoxy unit represented by
[2] Formula (I) below:

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
Elastomer represented by.

で表されるビシナルジオール単位の割合が、１０～９０mol％である、上記［１］または［２］に記載のエラストマー。 [3] Formula (1):

The elastomer according to [1] or [2] above, wherein the proportion of vicinal diol units represented by is 10 to 90 mol %.

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるエラストマー。 [4] Formula (II) below:

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
Elastomer represented by.

[5] The elastomer according to any one of [1] to [4] above, wherein each R is independently a hydrogen atom or a methyl group.

（式中、Ｒ^１は、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基であり、Ｒ^２は、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表される共重合体の製造方法であって、
式（４）：

（式中、Ｒ^１は、上記と同義である）
で表される５－シクロオクテン－１，２－ジオール化合物と、式（５）：

（式中、Ｒ^２は、上記と同義である）
で表されるシクロオクタ－１，５－ジエン化合物とを、開環メタセシス重合にて重合させることを特徴とする方法。 [6] Formula (III):

(wherein R ¹ is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group, and R ² is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group, be)
A method for producing a copolymer represented by
Formula (4):

(Wherein, R ¹ has the same definition as above)
and a 5-cyclooctene-1,2-diol compound represented by formula (5):

(Wherein, R ² has the same definition as above)
A method characterized by polymerizing a cycloocta-1,5-diene compound represented by ring-opening metathesis polymerization.

[7] The production method according to [6] above, wherein R ¹ and R ² are each independently a hydrogen atom or a methyl group.

[8] A composition for self-healing materials, comprising the elastomer according to any one of [1] to [5] above.

[9] A rubber modifier comprising the elastomer according to any one of [1] to [5] above.

In the elastomer of the present invention, adjacent hydroxy groups form a stronger hydrogen bond than a single hydroxy group. Since it exhibits elastomeric properties (elongation/shrinkability) without chemical crosslinking, it can be used as a remoldable and recyclable rubber or rubber modifier. Also, hydrogen bonds between adjacent hydroxy groups in the elastomer of the present invention are broken when an external force is applied, dissipating energy and relieving stress concentration. The elastomers of the present invention are thus toughened. Furthermore, the elastomer of the present invention has self-healing properties derived from dynamic cross-linking. For example, it has excellent properties such that it rejoins and recovers mechanical properties simply by bringing cut surfaces into contact and leaving them at room temperature.

1 is a ¹ H-NMR spectrum of polymer 1 (x:y=1:9 in formula (I)) of Example 1. FIG. 1 is a stress-strain diagram showing the relationship between stress and strain obtained by subjecting test pieces prepared from polymers 1 to 3 of Examples 1 to 3 to the tensile test of Test Example 1. FIG. 2 is a stress-strain diagram showing the relationship between stress and strain obtained in each cycle when a test piece prepared from Polymer 3 of Example 3 was subjected to the load-unloading cycle test of Test Example 2. FIG. A test piece (virgin) made from polymer 3 of Example 3 and the same test piece (3d healing) subjected to the self-healing test of Test Example 3 were subjected to the same tensile test as in Test Example 1. It is a stress-strain diagram showing the relationship between stress and strain. A test piece (virgin) made from polymer 3 of Example 3 and the same test piece (Recycled) subjected to the recycling test of Test Example 4 were subjected to the same tensile test as in Test Example 1, and the obtained stress and It is a stress-strain diagram showing the strain relationship.

で表されるビシナルジオール単位、および下記式（２）：

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるブタ－１－エン－１，４－ジイル単位を構成繰り返し単位として含む。 <Dynamic cross-linked elastomer>
The present invention relates to dynamically crosslinked elastomers. The elastomer of the present invention has the following formula (1):

and a vicinal diol unit represented by the following formula (2):

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
contains a but-1-ene-1,4-diyl unit represented by as a structural repeating unit.

（式中、Ｒは、上記と同義である）
で表されるエポキシ単位を、エラストマーを構成する全構成繰り返し単位に対して、５mol％以上の割合で含むものではない。 provided that the elastomer of the present invention has the formula (3):

(Wherein, R has the same definition as above)
The epoxy unit represented by is not contained in a ratio of 5 mol % or more with respect to all structural repeating units constituting the elastomer.

In the dynamically crosslinked elastomer of the present invention, adjacent hydroxy groups form strong hydrogen bonds, which act as relatively stable dynamic crosslinks in spite of the intermolecular interaction, giving the elastomer toughness and self-healing properties. It is characterized by giving sexuality. Therefore, the proportion of the vicinal diol units of formula (1) in the elastomer is not particularly limited as long as it is within a range that can impart toughness and self-healing properties to the elastomer. 10 mol % or more, preferably 15 mol % or more, more preferably 20 mol % or more, and 90 mol % or less, preferably 50 mol % or less, more preferably 40 mol % or less.

The dynamically crosslinked elastomers of the present invention contain but-1-ene-1,4-diyl units of formula (2) in addition to vicinal diol units of formula (1). Examples of but-1-ene-1,4-diyl units of formula (2) include but-1-ene-1,4-diyl (both R are hydrogen atoms), 1-methylbut-1-ene -1,4-diyl (1-position R is a methyl group, 2-position R is a hydrogen atom), 1-chlorobut-1-ene-1,4-diyl (1-position R is a chlorine atom, and R at the 2-position is a hydrogen atom). The but-1-ene-1,4-diyl unit of formula (2) is preferably but-1-ene-1,4-diyl or 1-methylbut-1-ene-1,4-diyl.

The proportion of the but-1-ene-1,4-diyl unit represented by formula (2) in the elastomer of the present invention is not particularly limited, but is 10 mol % or more, preferably 50 mol, based on all structural units constituting the elastomer. % or more, more preferably 60 mol % or more, and 90 mol % or less, preferably 85 mol % or less, more preferably 80 mol % or less.

The epoxy unit of formula (3) in the elastomer of the present invention may inevitably be formed from the vicinal diol unit of formula (1), and the ratio is within a range that does not impair the role of the vicinal diol unit described above. Specifically, it is less than 5 mol %, preferably less than 1 mol %, more preferably less than 0.1 mol %, based on all structural units constituting the elastomer. A particularly preferred embodiment of the elastomer of the present invention is substantially free of epoxy units of formula (3).

The dynamically crosslinked elastomer of the present invention contains the vicinal diol unit of formula (1) and the but-1-ene of formula (2) within a range that does not impair its excellent properties such as high elasticity, toughness, and self-healing property. In addition to -1,4-diyl units and optionally less than a predetermined amount of epoxy units of formula (3), optional constitutional units may be included. Such structural units are not particularly limited, but include, for example, structural units contained in known synthetic rubbers. Monomers that can derive such structural units include ethylene, propylene, styrene, acrylonitrile, acrylic acid, Examples include esters and vinyl acetate. The proportion of such optional constitutional units may be 20 mol % or less, preferably 10 mol % or less, more preferably 5 mol % or less, or may be free of any constitutional units.

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるエラストマーである。すなわち式（Ｉ）のエラストマーは、上記式（１）のビシナルジオール単位と、上記式（２）のブタ－１－エン－１，４－ジイル単位とからなるコポリマーである。なお上記式（Ｉ）は、コポリマーの各単位が、統計、ランダム、交互またはブロックのいずれであってもよいことを意味する。また各単位の割合（モル基準）は、ｘ：ｙ＝１：９～９：１の範囲であり、好ましくはｘ：ｙ＝３：１７～１：１の範囲であり、より好ましくはｘ：ｙ＝２：８～４：６の範囲である。 A preferred embodiment of the dynamically crosslinked elastomer of the present invention is represented by the following formula (I):

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
is an elastomer represented by That is, the elastomer of formula (I) is a copolymer comprising vicinal diol units of formula (1) above and but-1-ene-1,4-diyl units of formula (2) above. Note that formula (I) above means that each unit of the copolymer can be statistical, random, alternating or block. The ratio of each unit (on a molar basis) is in the range of x:y=1:9 to 9:1, preferably x:y=3:17 to 1:1, more preferably x: y=2:8 to 4:6.

（式中、Ｒは、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表されるエラストマーである。すなわち式（ＩＩ）のエラストマーは、５－シクロオクテン－１，２－ジオール化合物から誘導される、上記式（１）のビシナルジオール単位と上記式（２）のブタ－１－エン－１，４－ジイル単位とからなる単位と、シクロオクタ－１，５－ジエン化合物から誘導される、上記式（２）のブタ－１－エン－１，４－ジイル単位からなる単位とからなるコポリマーである。なお上記式（ＩＩ）は、コポリマーの各単位が、統計、ランダム、交互またはブロックのいずれであってもよいことを意味する。また各単位の割合（モル基準）は、ｎ：ｍ＝１：８～１：０の範囲であり、好ましくはｎ：ｍ＝３：１４～９：１の範囲であり、より好ましくはｎ：ｍ＝２：６～２：１の範囲である。 Similarly, another preferred embodiment of the dynamically crosslinked elastomer of the present invention is the following formula (II):

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
is an elastomer represented by That is, the elastomer of formula (II) is derived from a 5-cyclooctene-1,2-diol compound, the vicinal diol unit of formula (1) above and the but-1-ene-1, 4-diyl units and units composed of but-1-ene-1,4-diyl units of the above formula (2) derived from a cycloocta-1,5-diene compound. . Note that formula (II) above means that each unit of the copolymer can be statistical, random, alternating or block. The ratio of each unit (molar basis) is in the range of n:m=1:8 to 1:0, preferably in the range of n:m=3:14 to 9:1, more preferably n: m=2:6 to 2:1.

（式中、Ｒは、上記と同義である）
で表されるエポキシ単位を、エラストマーを構成する全構成繰り返し単位に対して、５mol％以上の割合で含むものではない。 In yet another preferred embodiment, the elastomers of formulas (I) and (II) are also represented by formula (3):

(Wherein, R has the same definition as above)
The epoxy unit represented by is not contained in a ratio of 5 mol % or more with respect to all structural repeating units constituting the elastomer.

The molecular weight of the dynamically crosslinked elastomer of the present invention is not particularly limited, but is about 2,000 to 1,000,000, preferably about 10,000 to 200,000, more preferably about 20,000. ~100,000.

In the dynamically crosslinked elastomer of the present invention, the vicinal diol unit of the above formula (1) and the but-1-ene-1, of the above formula (2) derived from a 5-cyclooctene-1,2-diol compound R in a unit consisting of a 4-diyl unit is independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group, preferably a hydrogen atom or a C _1-5 alkyl group, more preferably hydrogen It is an atom or a C _1-3 alkyl group, more preferably a hydrogen atom or a methyl group, particularly preferably a hydrogen atom. Plural R's present in the unit derived from the 5-cyclooctene-1,2-diol compound may be the same or different.

In the dynamically crosslinked elastomers of the present invention, R of the but-1-ene-1,4-diyl units are independently of each other hydrogen atoms, halogen atoms or C _1-5 alkyl groups, preferably hydrogen atoms or It is a C _1-5 alkyl group, more preferably a hydrogen atom or a C _1-3 alkyl group, still more preferably a hydrogen atom or a methyl group, particularly preferably a hydrogen atom. Plural R's present in the but-1-ene-1,4-diyl unit may be the same or different.

In the present specification, unless otherwise specified, the "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, preferably a fluorine atom or a chlorine atom, more preferably a chlorine atom. and the "C _1-5 alkyl group" includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group, a t-butyl group, a pentyl group and the like, preferably methyl or an ethyl group, more preferably a methyl group.

（式中、Ｒ^１は、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基であり、Ｒ^２は、互いに独立して、水素原子、ハロゲン原子またはＣ_１～５アルキル基である）
で表される共重合体の製造方法であって、
式（４）：

（式中、Ｒ^１は、上記と同義である）
で表される５－シクロオクテン－１，２－ジオール化合物と、式（５）：

（式中、Ｒ^２は、上記と同義である）
で表されるシクロオクタ－１，５－ジエン化合物とを、開環メタセシス重合にて重合させることを特徴とする方法である。 <Method for producing dynamically crosslinked elastomer>
One aspect of the method for producing the dynamically crosslinked elastomer of the present invention is represented by the following formula (II):

(wherein R ¹ is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group, and R ² is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group be)
A method for producing a copolymer represented by
Formula (4):

(Wherein, R ¹ has the same definition as above)
and a 5-cyclooctene-1,2-diol compound represented by formula (5):

(Wherein, R ² has the same definition as above)
A method characterized by polymerizing a cycloocta-1,5-diene compound represented by ring-opening metathesis polymerization.

The 5-cyclooctene-1,2-diol compound of formula (4), which is a raw material monomer, is a known compound and is available from reagent suppliers or can be synthesized according to known methods. . Examples of such synthetic methods include Reference Examples 1 and 2 described later. From the viewpoint of availability and the like, compounds in which R ¹ is a hydrogen atom, a halogen atom, a methyl group or an ethyl group are preferred, compounds in which a hydrogen atom or a methyl group are more preferred, and compounds in which a hydrogen atom is particularly preferred. Examples of such 5-cyclooctene-1,2-diol compounds of formula (4) include 5-cyclooctene-1,2-diol (both R ¹ are hydrogen atoms).

The cycloocta-1,5-diene compound of formula (5), which is the starting monomer, is also a known compound and is available from reagent suppliers or can be synthesized according to known methods. From the viewpoint of availability and the like, compounds in which R ¹ is a hydrogen atom, a halogen atom, a methyl group or an ethyl group are preferred, compounds in which a hydrogen atom or a methyl group are more preferred, and compounds in which a hydrogen atom is particularly preferred. Such cycloocta-1,5-diene compounds of formula (5) include cycloocta-1,5-diene (where all R ² are hydrogen atoms), 1-chlorocycloocta-1,5-diene ( 1-position R ² is a chlorine atom and the remaining R ² is a hydrogen atom), 1,5-dichlorocycloocta-1,5-diene (1- and 5-position R ² are chlorine atoms, the remaining R ² is a hydrogen atom), 1-methylcycloocta-1,5-diene (the R ² at the 1-position is a methyl group and the remaining R ² is a hydrogen atom), 1,5-dimethyl Examples include cycloocta-1,5-diene (R ² at the 1st and 5th positions are methyl groups, and the remaining R ² are hydrogen atoms).

The amount of each raw material monomer used is such that the vicinal diol structure contained in the 5-cyclooctene-1,2-diol compound of formula (4) is introduced at a rate that can impart toughness and self-healing properties to the elastomer. Although there is no particular limitation as long as it is possible, the ratio (molar ratio) of 5-cyclooctene-1,2-diol of formula (5) to the cycloocta-1,5-diene compound of formula (4) is 1:1: It is in the range of 8 to 1:0, preferably in the range of 3:14 to 9:1, more preferably in the range of 2:6 to 2:1.

で表される公知の化合物であり、試薬供給業者から入手可能である。 In the production method described above, a known catalyst used in ring-opening metathesis polymerization can be used. Such catalysts are available from reagent suppliers or can be synthesized according to known methods and are typically transition metal complexes such as titanium complexes, zirconium complexes, molybdenum complexes, ruthenium complexes, complexes, tantalum complexes, tungsten complexes and rhenium complexes. Among them, it is preferred to use catalysts such as transition metal-carbene complexes, for example Grubbs first generation catalysts, Grubbs second generation catalysts and Hoveyda-Grubbs catalysts. The Grubbs second-generation catalyst has the following formula:

is a known compound represented by and is available from reagent suppliers.

The amount of the catalyst used is not particularly limited, but it is preferably 0.001 to 10 mol %, more preferably 0.01 to 1 mol %, more preferably 0.01 to 0.01 mol %, relative to 1 mol of the total amount of raw material monomers used. 1 mol % is particularly preferred.

The above production method may be carried out in a solvent, and the solvent that can be used is a solvent that is inert to the reaction, and reaction conditions such as the type and amount of the monomers and catalysts used, and the desired reaction temperature. is selected as appropriate. For example, aliphatic halogen solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, aromatic hydrocarbon solvents such as benzene, toluene, xylene and mesitylene, monochlorobenzene, Aromatic halogen solvents such as dichlorobenzene and aliphatic hydrocarbon solvents such as hexane, heptane, octane and cyclohexane can be used, but the solvents that can be used are not limited thereto. These solvents may be used alone or in combination of two or more.

The above production method can be carried out at a temperature appropriately selected from the range of -50°C to 180°C. From the viewpoint of reaction rate and yield, -20 to 100°C is preferred, -10 to 80°C is more preferred, and room temperature (about 25±5°C) is particularly preferred. The reaction time is appropriately set according to conditions such as the amounts and types of the raw material monomers, catalyst and solvent used, and the reaction temperature, and is not particularly limited, but is preferably 1 to 24 hours from the viewpoint of reaction rate and yield. . The reaction pressure may be pressurized, reduced pressure or atmospheric pressure, but atmospheric pressure is preferred. The reaction atmosphere is preferably an inert gas atmosphere such as nitrogen or argon.

There are no particular restrictions on the order of addition of essential components (raw material monomers and catalysts) used in the above production method and optional components (solvents, other monomer components, etc.) used as necessary, and any order. can be added to a suitable reaction vessel to initiate the reaction. After completion of the reaction, the elastomer represented by the formula (II) can be isolated and purified from the reaction solution, if necessary. The method of isolation and purification is not particularly limited, and a method known to those skilled in the art, for example, the reaction solution after completion of the reaction may be dropped into a poor solvent to deposit a precipitate, which may be collected by filtration.

This production method hydrolyzes some of the epoxy groups of the epoxidized natural (synthetic) rubber to introduce a diol (vicinal diol) structure into the main chain, unlike the polymer obtained by the conventional production method. Elastomers which are substantially free of epoxy groups can be obtained. In addition, in the production method of the present invention, a vicinal diol structure that imparts toughness and self-healing properties to the elastomer can be introduced without relying on ring-opening of the epoxy group, so that the introduction ratio of the vicinal diol structure can be easily adjusted. , an elastomer with desired properties can be efficiently produced.

<Composition for self-healing material/rubber modifier>
The elastomer of the present invention has self-healing properties derived from dynamic cross-linking, and has excellent properties such that, for example, simply by bringing cut surfaces into contact with each other and allowing them to stand at room temperature, they rejoin and recover their mechanical properties. Therefore, compositions containing the elastomers of the invention can be used as self-healing materials. The composition for self-healing materials of the present invention contains 10 to 99% by mass of the elastomer of the present invention, depending on its use.

Further, the elastomer of the present invention has toughness in addition to self-healing properties. Therefore, the elastomers of the present invention can be used as rubber modifiers. The rubber improver of the present invention contains 10-99% by weight of the elastomer of the present invention, depending on its application.

The composition for self-healing materials or the rubber improver of the present invention may contain known additives such as inorganic fillers, reinforcing agents, and coloring agents, depending on the purpose, as long as the effects of the present invention are not impaired. agent, stabilizer, bulking agent, solvent, viscosity modifier, tackifier, flame retardant, UV absorber, antioxidant, anti-discoloration agent, antibacterial agent, anti-mold agent, anti-aging agent, antistatic agent, plasticizer , a lubricant, a smoothing agent, a foaming agent, a release agent, and the like.

<Reference example 1>
Synthesis of (Z)-9-oxabicyclo[6.1.0]non-4-ene
A solution of m-chlorobenzoic acid (mCPBA) (<70%, 50.0 g, 202.8 mmol) in chloroform (400 mL) was added to 1,5-cyclooctadiene (16.2 g, 150.1 mmol) at 0°C. added gradually. The mixture was stirred at room temperature for 12 hours. The mixture was diluted with saturated aqueous sodium bicarbonate and then excess sodium sulfite was added. The solution was extracted with chloroform and washed with brine. The organic layer was dried over magnesium sulphate and evaporated. The resulting residue was purified by column chromatography (eluent: ethyl acetate/hexane=1/15) to obtain 14.9 g of the desired compound (yield: 80%).

<Reference example 2>
Synthesis of (Z)-cyclooct-5-ene-1,2-diol
(Z)-9-Oxabicyclo[6.1.0]non-4-ene (4 g, 32.2 mmol) obtained in Reference Example 1 was dissolved in water (200 mL), and 2-3 drops of Concentrated sulfuric acid was added. The mixture was stirred overnight at room temperature. The solution was extracted with chloroform and the organic layer was treated with saturated aqueous sodium bicarbonate. The organic layer was then washed with brine. The organic layer was dried over magnesium sulphate and evaporated. The resulting residue was purified by column chromatography (eluent: ethyl acetate/hexane=1/1) to obtain 2.74 g of the desired compound (yield: 60%).

<Example 1>
Polymerization of polymer 1
A Schlenk flask was charged with (Z)-cyclooct-5-ene-1,2-diol (0.233 g, 1.64 mmol), 1,5-cyclooctadiene (0.71 g, 6.44 mmol) and anhydrous dichloromethane (5 mL). was added. A separate Schlenk flask was charged with Grubbs second generation catalyst (2.37 mg) and anhydrous tetrahydrofuran (5 mL). The two solutions were degassed by a freeze degassing cycle and the catalyst solution was transferred to the monomer solution via cannula. The mixture was stirred at room temperature for 24 hours. The reaction mixture was quenched with ethyl vinyl ether. The reaction mixture was precipitated from 2,6-di-t-butyl-4-methylphenol (BHT) containing methanol. The precipitate was collected and dried under reduced pressure to obtain 0.57 g (yield: 60%) of a gum-like substance. FIG. 1 shows the ¹ H-NMR spectrum of the obtained polymer 1 (x:y=1:9 in formula (I)).

<Example 2>
Polymerization of polymer 2
Same as Example 1 except that 0.495 g (3.49 mmol) of (Z)-cyclooct-5-ene-1,2-diol and 0.880 g (8.13 mmol) of 1,5-cyclooctadiene were used. Similarly, 0.82 g (yield: 60%) of polymer 2 (x:y=1.5:8.5 in formula (I)) was obtained.

<Example 3>
Polymerization of polymer 3
Same as Example 1 except that 0.289 g (2.03 mmol) of (Z)-cyclooct-5-ene-1,2-diol and 0.88 g (8.13 mmol) of 1,5-cyclooctadiene were used. Similarly, 0.70 g of polymer 3 (x:y=2:8 in formula (I)) was obtained (yield: 60%).

<Test Example 1>
Tensile test
The tensile test was performed with a precision universal testing machine (AGS-X 100N, manufactured by Shimadzu Corporation). As test pieces, dumbbell-shaped films formed by molding polymers 1 to 3 obtained in Examples 1 to 3, respectively, were used. The dimensions of the parallel portion of the dumbbell-shaped specimen were 8.4 x 1.4 x 0.3 mm (length x width x thickness). A pulling speed of 50 mm/min was employed. Each measurement was repeated at least three times. All tests were performed at room temperature. The results are shown in FIG. It can be seen from FIG. 2 that each polymer becomes tougher as the ratio of vicinal diol units increases.

<Test Example 2>
cycle test
The cycle test was performed using a precision universal testing machine (AGS-X 100N, manufactured by Shimadzu Corporation). As a test piece, a dumbbell-shaped film formed by molding the polymer 3 obtained in Example 3 was used. The dimensions of the parallel portion of the dumbbell-shaped specimen were 8.4 x 1.4 x 0.3 mm (length x width x thickness). Each specimen was loaded to 600% elongation on each cycle and then unloaded to its original length. A load-unload rate of 50 mm/min was employed. During the self-healing test, load-unload cycles were repeated with delay times of 0 seconds and 1 hour. All tests were performed at room temperature. The results are shown in FIG. It can be seen from FIG. 3 that the toughness of the polymer is almost maintained even after repeated loading-unloading cycles.

<Test Example 3>
Self-healing test
In the self-healing test, a dumbbell-shaped film formed from polymer 3 obtained in Example 3 was used as a test piece. The dimensions of the parallel portion of the dumbbell-shaped specimen were 8.4 x 1.4 x 0.3 mm (length x width x thickness). Each specimen was first cut in two with a knife and immediately reconnected without applying any significant pressure. The reconnected specimen was placed in a desiccator. After a given period of time (3 days), the specimens were removed and subjected to tensile testing. Each measurement was repeated at least three times. All tests were performed at room temperature. The results are shown in FIG. It can be seen from FIG. 4 that the reconnected specimen (3d hearing) exhibits similar tensile strength, although the breaking point is lower than that of the specimen not subjected to the self-healing test (virgin).

<Test Example 4>
recycling test
In the recycling test, a dumbbell-shaped film formed by molding the polymer 3 obtained in Example 3 was used as a test piece. The dimensions of the parallel portion of the dumbbell-shaped specimen were 8.4 x 1.4 x 0.3 mm (length x width x thickness). The specimen was cut into small pieces and then pressed at 10 MPa for 20 minutes at a fixed temperature of 80°C. The recycled specimens were subjected to tensile testing. The results are shown in FIG. It can be seen from FIG. 5 that the recycled test piece (Recycled) exhibits the same tensile strength as the test piece (virgin) not subjected to the recycling test.

The elastomer of the present invention exhibits elastomer properties (elongation/contraction properties) without chemical cross-linking such as vulcanization, and has toughness. Therefore, it can be used as a re-moldable and recyclable rubber or a rubber modifier. In addition, the elastomer of the present invention has self-healing properties derived from dynamic cross-linking. For example, it has an excellent property that it rejoins simply by bringing the cut surfaces into contact and leaving them at room temperature to recover the mechanical properties. , can be used for compositions for self-healing materials.

Claims (8)

Formula (1):

and a vicinal diol unit represented by the formula (2):

(Wherein R is independently of _each other a hydrogen atom, a halogen atom or a C1-5 alkyl group)
An elastomer containing a but -1-ene-1,4-diyl unit represented by the formula (1) with respect to all structural units constituting the elastomer is 10 to 40 mol%, the but-1-ene-1,4-diyl unit represented by formula (2) is 60 to 90 mol%, and formula (3):

(Wherein, R has the same definition as above)
An elastomer containing no more than 5 mol% of the epoxy unit represented by Formula (I) below:

(Wherein R is independently a hydrogen atom, a halogen atom or a C1-5 alkyl group, and x:y is ₁ :9-4:6 (on a molar basis) )
Elastomer represented by. Formula (II) below:

(Wherein R is each independently a hydrogen atom, a halogen atom or a C1-5 alkyl group , and n:m is 2:6 to 2:1 (on a molar basis) ₎
Elastomer represented by. Elastomer according to any one of claims 1 to 3 , wherein R is, independently of each other, a hydrogen atom or a methyl group. Formula (III):

(wherein R ¹ is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group, and R ² is each independently a hydrogen atom, a halogen atom or a C _1-5 alkyl group , Yes, and n:m is 2:6 to 2:1 (molar basis) )
A method for producing a copolymer represented by
Formula (4):

(Wherein, R ¹ has the same definition as above)
and a 5-cyclooctene-1,2-diol compound represented by formula (5):

(Wherein, R ² has the same definition as above)
A method characterized by polymerizing a cycloocta-1,5-diene compound represented by by ring-opening metathesis polymerization at a ratio in the range of 2:6 to 2:1 (on a molar basis) . 6. The production method according to claim 5 , wherein ^R1 and ^R2 are each independently a hydrogen atom or a methyl group. A composition for self-healing materials, comprising the elastomer according to any one of claims 1-4 . A rubber modifier comprising the elastomer according to any one of claims 1-4 .

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