JP2012040136A - Composition for mouth guard, sheet for mouth guard, and mouth guard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for a mouth guard and a sheet for the mouth guard which are used for manufacturing a mouth guard which excels in impact absorbency, can be made thinner and lighter than conventional ones and has a good feeling of fitting, as well as the mouth guard which has these characteristics.SOLUTION: The composition for the mouth guard contains 50-100 pts.wt. of a 4-methyl-1-pentene propylene copolymer (A) consisting of a constituent unit (i) derived from 4-methyl-1-pentene of 15-75 mol% and a constituent unit (ii) derived from propylene of 25-85 mol% (where, the sum total of the rate of the constituent unit (i) and that of the constituent unit (ii) is 100 mol%), and a thermoplastic resin or rubber (B) of 50-0 pts.wt. (where, the total amount of the copolymer (A) and the resin or the rubber (B) is 100 pts.wt.).

Description

  The present invention relates to a mouth guard composition, a mouth guard sheet, and a mouth guard.

  In sports that involve intense movements such as boxing, rugby, and American football, dental guards commonly called mouth guards (also called mouthpieces) are commonly used to protect the teeth and reduce the impact on the brain. Widely used.

  Conventionally, a mouth guard made of ethylene-vinyl acetate copolymer (EVA) has been known, but there are various mouth guards due to problems such as low shock absorption and easy breakage due to the application of occlusal force. Has been developed.

  For example, JP 2002-355352 A, WO 2002/98521 pamphlet (Patent Documents 1 and 2), etc. describe a hydrogenated styrene / isoprene / styrene copolymer (hydrogenated SIS) mouthguard material. And a mouth guard are disclosed.

  JP-A-2001-54610 and JP-A-2009-84326 (Patent Documents 3 and 4) disclose mouth guard materials and mouth guards based on styrene / ethylene butylene / styrene copolymers (SEBS). ing.

  Examples using polyolefin-based materials are also known, and Japanese Patent Application Laid-Open Nos. 5-23353 (Patent Document 5) and 5-23354 (Patent Document 6) disclose ethylene-α-olefin- An orthodontic orthodontic appliance formed from a crosslinked product obtained by crosslinking a diene copolymer is disclosed. Further, JP-A-2005-385 (Patent Document 7) discloses a linear low-density ethylene-α-olefin obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms with a metallocene catalyst. A mouthpiece molding material and a mouthpiece made of a copolymer are disclosed.

  On the other hand, International Publication No. 96/28507 (Patent Document 8) and International Publication No. 2005/121192 (Patent Document 9) include 4-methyl-1-pentene copolymers and compositions containing the same. Is disclosed. However, these documents do not describe mouth guard.

JP 2002-355352 A International Publication No. 2002/98521 Pamphlet JP 2001-54610 A JP 2009-84326 A Japanese Patent Laid-Open No. 5-23353 JP-A-5-23354 JP 2005-385 A International Publication No. 96/28507 Pamphlet International Publication No. 2005/121192 Pamphlet

  As described above, various mouth guard materials and mouth guards are conventionally known. However, hydrogenated SIS mouth guards (Patent Documents 1 and 2) are insufficient in shock absorption and light weight, and SEBS mouth guards (Patent Documents 3 and 4) have shock absorption and stress relaxation. And lightness were insufficient. Moreover, since the hydrogenated SIS type | system | group and SEBS type | system | group mouth guard of the said description contain the oligomer derived from styrene, there existed the subject on the hygiene side.

The orthodontic appliances described in Patent Documents 5 and 6 have room for further improvement in terms of impact absorption and flexibility.
Furthermore, the mouthpiece molding material described in Patent Document 7 needs to be improved in terms of impact absorption, flexibility, and lightness.

  The object of the present invention is to solve the above-mentioned problems in the prior art. Specifically, the mouth guard (excellent in shock absorption, thinner and lighter than the conventional one and having a good wearing feeling) An object of the present invention is to provide a mouth guard composition for manufacturing a sports mouth guard, a mouth guard sheet, and a mouth guard having such characteristics.

The composition for mouthguard of the present invention,
The structural unit (i) derived from 15 to 75 mol% of 4-methyl-1-pentene and the structural unit (ii) derived from 25 to 85 mol% of propylene (provided that the proportion and configuration of the structural unit (i) 50 to 100 parts by weight of 4-methyl-1-pentene / propylene copolymer (A) consisting of the proportion of the unit (ii) is 100 mol%, and a thermoplastic resin or rubber (B ) 50 to 0 parts by weight (however, the total amount of the copolymer (A) and the resin or rubber (B) is 100 parts by weight)
Is contained.

  The mouthguard composition is preferably 50 to 98 parts by weight of the 4-methyl-1-pentene / propylene copolymer (A) and 50 to 2 parts by weight of the thermoplastic resin or rubber (B). contains.

The mouth guard sheet of the present invention is characterized by comprising the mouth guard composition of the present invention.
The mouth guard of the present invention is characterized by comprising the mouth guard composition of the present invention.

  According to the present invention, a mouth guard composition and a mouth guard sheet suitable for manufacturing a mouth guard that is excellent in shock absorption, thinner than conventional ones, lighter in weight and easy to wear, and such characteristics are provided. A mouth guard is provided.

  Hereinafter, the composition for mouth guard, the seat for mouth guard and the mouth guard of the present invention will be described in more detail.

[Mouth guard composition]
The composition for mouthguard of the present invention,
The structural unit (i) derived from 15 to 75 mol% of 4-methyl-1-pentene and the structural unit (ii) derived from 25 to 85 mol% of propylene (provided that the proportion and configuration of the structural unit (i) 50 to 100 parts by weight of 4-methyl-1-pentene / propylene copolymer (A) consisting of the proportion of the unit (ii) is 100 mol%, and a thermoplastic resin or rubber (B ) 50 to 0 parts by weight (however, the total amount of the copolymer (A) and the resin or rubber (B) is 100 parts by weight)
Containing.
An embodiment in which the amount of the thermoplastic resin or rubber (B) is 0 part by weight is also expressed as a “composition” for convenience.

<4-Methyl-1-pentene / propylene copolymer (A)>
The 4-methyl-1-pentene / propylene copolymer (A) is derived from a structural unit (i) derived from 15 to 75 mol% of 4-methyl-1-pentene and 25 to 85 mol% of propylene. The structural unit (ii) is included (however, the sum of the proportion of the structural unit (i) and the proportion of the structural unit (ii) is 100 mol%).

  The proportion of the structural unit (i) derived from 4-methyl-1-pentene is preferably 20 to 72 mol%, more preferably 20 to 65 mol%, still more preferably 20 to 33 mol%. .

  Further, the proportion of the structural unit (ii) derived from propylene is preferably 28 to 80 mol%, more preferably 35 to 80 mol%, and further preferably 67 to 80 mol%.

  If the proportion of the structural unit (i) is less than 15 mol%, the shock absorption, flexibility, and lightness of the mouth guard are impaired, and if it exceeds 75 mol%, the shock absorption of the mouth guard is impaired. And flexibility are impaired.

  The 4-methyl-1-pentene / propylene copolymer (A) is a structural unit derived from another monomer as long as it is a small amount (for example, 10 mol% or less) that does not impair the object of the present invention. May be included. Specific examples of other monomers are preferably ethylene, 1-butene, 1-hexene, 1-octene and the like.

  The intrinsic viscosity [η] of the 4-methyl-1-pentene / propylene copolymer (A) in decalin at 135 ° C. is preferably 0.01 to 5.0 (dL / g), more preferably It is 0.05 to 4.0 (dL / g), more preferably 0.1 to 3.0 (dL / g), and particularly preferably 0.5 to 2.5 (dL / g). As described later, when hydrogen is used together during polymerization, the molecular weight can be controlled, and the intrinsic viscosity [η] can be adjusted by freely obtaining from a low molecular weight body to a high molecular weight body.

  The weight average molecular weight (Mw) of the 4-methyl-1-pentene / propylene copolymer (A) measured by gel permeation chromatography (GPC) is preferably 500 to 10,000 in terms of polystyrene. 1,000, more preferably 1,000 to 5,000,000, and still more preferably 1,000 to 2,500,000.

  The ratio (molecular weight distribution) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of the 4-methyl-1-pentene / propylene copolymer (A). Mw / Mn) is preferably 1.0 to 3.5, more preferably 1.2 to 3.0, and still more preferably 1.5 to 2.5.

The copolymer (A) having a value of Mw / Mn within the above range is advantageous in producing a mouth guard having excellent mechanical properties and wear resistance with excellent moldability, and has industrial value. Is higher.
If the catalyst described later is used, the copolymer (A) having a value of Mw / Mn within the above range within the range of the intrinsic viscosity [η] or the weight average molecular weight (Mw) described above can be obtained. it can. The values of Mw / Mn and Mw are values measured by the method employed in the examples described later.

  The amount of 4-methyl-1-pentene / propylene copolymer (A) extracted with methyl acetate is preferably 0 to 1.5% by weight, more preferably 0 to 1.0% by weight, and still more preferably 0. It is -0.8 weight%, Most preferably, it is 0-0.5 weight%. The amount of methyl acetate extracted becomes an index of stickiness during molding. When this value is large, the obtained polymer has a large composition distribution and contains a low molecular weight polymer, causing problems during molding. When the methyl acetate extraction amount is within the above range, there is no problem due to stickiness during molding. Also, by using the catalyst described later, a copolymer (A) with a low stereoregularity and a small atactic component can be synthesized. By molding the obtained polymer, a mouth guard having no stickiness and excellent hygiene can be obtained. It is done.

The density (measured by ASTM D 1505) of the 4-methyl-1-pentene / propylene copolymer (A) is preferably 880 to 810 kg / m ³ , more preferably 860 to 820 kg / m ³ , and still more preferably. 855 to 830 kg / m ³ .

  The density can be changed by the comonomer composition ratio of the 4-methyl-1-pentene / propylene copolymer (A), and the copolymer (A) within the above range is used for producing a lightweight mouth guard. It is advantageous.

  The melting point [Tm] of the 4-methyl-1-pentene / propylene copolymer (A) measured by a differential scanning calorimeter (DSC) is preferably less than 110 ° C. or not recognized. The melting point can be changed depending on the comonomer composition ratio of the 4-methyl-1-pentene / propylene copolymer (A), and the copolymer (A) within the above range is used for producing a flexible mouth guard. It is advantageous.

  Measurement of dynamic viscoelasticity of the 4-methyl-1-pentene / propylene copolymer (A) at a frequency of 10 rad / s in a temperature range of −40 ° C. to + 180 ° C. (details of measurement conditions and the like will be described later) The maximum value of the loss tangent tan δ obtained as described above is preferably 0.1 to 10, more preferably 0.4 to 8.0, and still more preferably 0.6 to 6.0, particularly preferably 1.5 to 5.0, particularly preferably 2.0 to 4.0. The temperature at which the value of tan δ is maximized is preferably −50 ° C. to 100 ° C., more preferably −30 ° C. to 50 ° C., further preferably −10 ° C. to 40 ° C., and particularly preferably 0 ° C. to 40 ° C. It is in the range of ° C. The maximum value of tan δ can be controlled by the comonomer composition ratio of the 4-methyl-1-pentene / propylene copolymer (A). For example, the 4-methyl-1-pentene content in the copolymer (A) is determined. By setting it to 20 to 72 mol%, the maximum value of tan δ can be within the above range.

The 4-methyl-1-pentene / propylene copolymer (A) has a rebound resilience (%) defined by the following formula of 0 to 25% at 40 ° C., which is a temperature condition assuming the oral cavity. Preferably it is 0 to 20%, more preferably 0 to 10%.
Rebound resilience (%) = (Rebound height) (mm) / 460 × 100

  The rebound resilience can be controlled by the comonomer composition ratio of the 4-methyl-1-pentene / propylene copolymer (A). For example, the rebound resilience can be achieved by setting the 4-methyl-1-pentene content to 20 to 65 mol%. The elastic modulus can be within the above range.

<Manufacturing method>
Next, a method for producing 4-methyl-1-pentene / propylene copolymer (A) will be described.

  For the production of the 4-methyl-1-pentene / propylene copolymer (A), a conventionally known catalyst such as a magnesium-supported titanium catalyst, WO 01/53369, WO 01/27124, etc. The metallocene catalyst described in JP-A-3-193966 or JP-A-02-41303 is preferably used, and more preferably a metallocene compound represented by the following general formula (1) or (2): The contained olefin polymerization catalyst is preferably used.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｒ¹³およびＲ¹⁴は、水素、炭化水素基およびケイ素含有炭化水素基から選ばれ、それぞれ同一でも異なっていてもよく、Ｒ¹からＲ⁴までの隣接した置換基は互いに結合して環を形成してもよく、Ｒ⁵からＲ¹²までの隣接した置換基は互いに結合して環を形成してもよく、
Ａは一部不飽和結合および／または芳香族環を含んでいてもよい炭素原子数２〜２０の２価の炭化水素基であり、ＡはＹと共に形成する環を含めて２つ以上の環構造を含んでいてもよく、
Ｍは周期表第４族から選ばれた金属であり、
Ｙは炭素またはケイ素であり、
Ｑはハロゲン、炭化水素基、およびアニオン配位子または孤立電子対で配位可能な中性配位子から同一のまたは異なる組合せで選ばれ、
ｊは１〜４の整数である。）
上記一般式（１）または（２）のＲ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｒ¹³およびＲ¹⁴は、水素、炭化水素基およびケイ素含有炭化水素基から選ばれ、それぞれ同一でも異なっていてもよい。

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are hydrogen, carbonized, Selected from a hydrogen group and a silicon-containing hydrocarbon group, which may be the same or different, and adjacent substituents from R ¹ to R ⁴ may be bonded to each other to form a ring; R ⁵ to R ¹² Up to adjacent substituents may combine with each other to form a ring,
A is a divalent hydrocarbon group having 2 to 20 carbon atoms which may partially contain an unsaturated bond and / or an aromatic ring, and A is two or more rings including a ring formed with Y May contain structure,
M is a metal selected from Group 4 of the periodic table,
Y is carbon or silicon;
Q is selected from the same or different combinations from halogen, hydrocarbon groups, and anionic ligands or neutral ligands capable of coordinating with lone pairs;
j is an integer of 1-4. )
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ^{13 in the} general formula (1) or (2) R ¹⁴ is selected from hydrogen, a hydrocarbon group and a silicon-containing hydrocarbon group, and may be the same or different.

  The hydrocarbon group is preferably an alkyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkylaryl group having 7 to 20 carbon atoms. Yes, it may contain one or more ring structures. Moreover, a part or all of hydrogen of the hydrocarbon group may be substituted with a functional group such as a hydroxyl group, an amino group, a halogen group, or a fluorine-containing hydrocarbon group. Specific examples of the hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1,1-diethylpropyl, and 1-ethyl-1. -Methylpropyl, 1,1,2,2-tetramethylpropyl, sec-butyl, tert-butyl, 1,1-dimethylbutyl, 1,1,3-trimethylbutyl, neopentyl, cyclohexylmethyl, cyclohexyl, 1-methyl -1-cyclohexyl, 1-adamantyl, 2-adamantyl, 2-methyl-2-adamantyl, menthyl, norbornyl, benzyl, 2-phenylethyl, 1-tetrahydronaphthyl, 1-methyl-1-tetrahydronaphthyl, phenyl, biphenyl, Naphthyl, tolyl, chlorophenyl, chlorobipheny , Chloronaphthyl, and the like.

  The silicon-containing hydrocarbon group is preferably an alkylsilyl group or arylsilyl group having 1 to 4 silicon atoms and 3 to 20 carbon atoms, and specific examples thereof include trimethylsilyl, tert-butyldimethylsilyl, triphenylsilyl and the like. Is mentioned.

Adjacent substituents from R ⁵ to R ¹² on the fluorene ring may be bonded to each other to form a ring. Examples of such a substituted fluorenyl group include benzofluorenyl, dibenzofluorenyl, octahydrodibenzofluorenyl, octamethyloctahydrodibenzofluorenyl and the like.

The substituents R ⁵ to R ¹² on the fluorene ring are symmetrical from the viewpoint of synthesis, that is, R ⁵ = R ¹² , R ⁶ = R ¹¹ , R ⁷ = R ¹⁰ , and R ⁸ = R ^9. And the fluorene ring is more preferably unsubstituted fluorene, 3,6-disubstituted fluorene, 2,7-disubstituted fluorene or 2,3,6,7-tetrasubstituted fluorene. Wherein the 3-position on the fluorene ring, 6-position, 2-position, 7-position corresponds to the ^{R 7, R 10, R 6} , R 11 , respectively.

R ¹³ and R ^{14 in} the general formula (1) are selected from hydrogen and a hydrocarbon group, and may be the same or different. Specific examples of preferred hydrocarbon groups include the same as those described above.

Y is carbon or silicon. In the case of the general formula (1), R ¹³ and R ¹⁴ are bonded to Y to form a substituted methylene group or a substituted silylene group as a bridging part. Preferred examples include methylene, dimethylmethylene, diisopropylmethylene, methyl tert-butylmethylene, dicyclohexylmethylene, methylcyclohexylmethylene, methylphenylmethylene, fluoromethylphenylmethylene, chloromethylphenylmethylene, diphenylmethylene, dichlorophenylmethylene, difluorophenylmethylene. Methylnaphthylmethylene, dibiphenylmethylene, di-p-methylphenylmethylene, methyl-p-methylphenylmethylene, ethyl-p-methylphenylmethylene, dinaphthylmethylene or dimethylsilylene, diisopropylsilylene, methyl-tert-butylsilylene, dicyclohexyl Silylene, methylcyclohexylsilylene, methylphenylsilylene, fluoromethyl Enirushiriren, chloromethyl silylene, diphenyl silylene, mention may be made of di-p- methylphenyl silylene, methyl -p- methylphenyl silylene, ethyl -p- methylphenyl silylene, methyl naphthyl silylene, a dinaphthyl silylene like.

  In the case of the general formula (2), Y is bonded to a divalent hydrocarbon group A having 2 to 20 carbon atoms which may partially contain an unsaturated bond and / or an aromatic ring, and a cycloalkylidene group or It constitutes a cyclomethylenesilylene group and the like. Preferred examples include cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexylidene, cycloheptylidene, bicyclo [3.3.1] nonylidene, norbornylidene, adamantylidene, tetrahydronaphthylidene, dihydroindanidene. Examples include lidene, cyclodimethylenesilylene, cyclotrimethylenesilylene, cyclotetramethylenesilylene, cyclopentamethylenesilylene, cyclohexamethylenesilylene, cycloheptamethylenesilylene, and the like.

M in the general formulas (1) and (2) is a metal selected from Group 4 of the periodic table, and examples of M include titanium, zirconium, and hafnium.
Q is selected from the same or different combinations from halogen, a hydrocarbon group having 1 to 20 carbon atoms, and an anionic ligand or a neutral ligand capable of coordinating with a lone electron pair. Specific examples of the halogen include fluorine, chlorine, bromine and iodine, and specific examples of the hydrocarbon group include the same as those described above. Specific examples of the anionic ligand include alkoxy groups such as methoxy, tert-butoxy and phenoxy, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate. Specific examples of neutral ligands that can be coordinated by a lone pair include organophosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, diphenylmethylphosphine, and tetrahydrofuran, diethyl ether, dioxane, 1,2- And ethers such as dimethoxyethane. Among these, Q may be the same or different combinations, but at least one is preferably a halogen or an alkyl group.

  Specific examples of the metallocene compound in the present invention include compounds exemplified in WO 01/27124, WO 2006/025540, or WO 2007/308607. In particular, this does not limit the scope of the present invention.

When using a metallocene compound for the production of the 4-methyl-1-pentene / propylene copolymer (A), the catalyst component is:
(A) a metallocene compound (for example, a metallocene compound represented by the above general formula (1) or (2));
(B) (b-1) an organoaluminum oxy compound,
(B-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and (b-3) at least one compound selected from organoaluminum compounds;
If necessary,
(C) It is comprised from a particulate carrier. As a production method, for example, the method described in International Publication No. 01/27124 pamphlet can be employed.

  Further, it reacts with an organoaluminum oxy compound (b-1) (hereinafter also referred to as “component (b-1)”) and a metallocene compound (a) (hereinafter also referred to as “component (a)”) to form an ion pair. Specifics of compound to be formed (hereinafter also referred to as “component (b-2)”), organoaluminum compound (b-3) (hereinafter also referred to as “component (b-3)”), and particulate carrier (c) Examples include those compounds or carriers conventionally known in the field of olefin polymerization, such as the specific examples described in WO 01/27124.

In the production of the 4-methyl-1-pentene / propylene copolymer (A), the polymerization can be carried out by either a liquid phase polymerization method such as solution polymerization or suspension polymerization or a gas phase polymerization method.
In the liquid phase polymerization method, an inert hydrocarbon solvent may be used. Specific examples of the inert hydrocarbon include aliphatic carbon such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene. Hydrogen; cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogens such as ethylene chloride, chlorobenzene, dichloromethane, trichloromethane, and tetrachloromethane And hydrocarbons, and mixtures thereof.

Bulk polymerization using 4-methyl-1-pentene and propylene itself as a solvent can also be carried out.
Further, 4-methyl-1-pentene / propylene copolymer having a controlled composition distribution was obtained by performing stepwise polymerization of 4-methyl-1-pentene and copolymerization of 4-methyl-1-pentene and propylene. It is also possible to obtain a polymer (A).

In carrying out the polymerization, the component (a) is usually 10 ⁻⁸ to 10 ⁻² mol, preferably 10 ⁻⁷ to 10 ⁻³ mol, in terms of group 4 metal atom in the periodic table, per liter of reaction volume. Used in various amounts. In the component (b-1), the molar ratio [(b-1) / M] of the component (b-1) and the transition metal atom (M) in the component (a) is usually 0.01 to 5000, Preferably it is used in such an amount that it is 0.05-2000. In the component (b-2), the molar ratio [(b-2) / M] of the component (b-2) and the transition metal atom (M) in the component (a) is usually 1 to 10, preferably 1. Used in an amount such that it is ˜5. Component (b-3) has a molar ratio [(b-2) / M] of component (b-3) to transition metal atom (M) in component (a) of usually 10 to 5000, preferably 20 It is used in an amount such that it is ˜2000.

The polymerization temperature is usually in the range of −50 to 200 ° C., preferably 0 to 100 ° C., more preferably 20 to 100 ° C.
The polymerization pressure is usually normal pressure to 10 MPa gauge pressure, preferably normal pressure to 5 MPa gauge pressure, and the polymerization reaction can be carried out in any of batch, semi-continuous and continuous methods. Furthermore, the polymerization can be performed in two or more stages having different reaction conditions.

  Hydrogen may be added for the purpose of controlling the molecular weight and polymerization activity of the produced polymer during the polymerization, and the amount is suitably about 0.001 to 100 NL per 1 kg of the total of 4-methyl-1-pentene and propylene.

<Thermoplastic resin or rubber (B)>
The thermoplastic resin or rubber (B) is not particularly limited, and examples thereof include the following resins and rubbers.

Thermoplastic polyolefin resin (excluding the copolymer (A)), specifically, low density, medium density, high density polyethylene, high pressure method low density polyethylene, isotactic polypropylene, syndiotactic polypropylene, poly 1-butene, poly-4-methyl-1-pentene, poly-3-methyl-1-butene, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, 1-butene / α-olefin copolymer , Cyclic olefin copolymer, chlorinated polyolefin;
Thermoplastic polyamide resins, specifically aliphatic polyamides (nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 612);
Thermoplastic polyester resin, specifically, polyethylene terephthalate, polybutylene terephthalate, polyester elastomer;
Thermoplastic vinyl aromatic resins, specifically polystyrene, ABS resin, AS resin, styrene elastomer (styrene / butadiene / styrene block polymer, styrene / isoprene / styrene block polymer, styrene / isobutylene / styrene block polymer, and The aforementioned hydrogenated product);
Thermoplastic polyurethane; vinyl chloride resin; vinylidene chloride resin; acrylic resin; ethylene / vinyl acetate copolymer; ethylene / methacrylic acid acrylate copolymer; ionomer; ethylene / vinyl alcohol copolymer; polyvinyl alcohol; Polyacetal; Polyphenylene oxide; Polyphenylene sulfide polyimide; Polyarylate; Polysulfone; Polyethersulfone; Rosin resin; Terpene resin; Petroleum resin;
Copolymer rubber, specifically, ethylene / α-olefin / diene copolymer, propylene / α-olefin / diene copolymer, 1-butene / α-olefin / diene copolymer, polybutadiene rubber, polyisoprene Examples thereof include rubber, neoprene rubber, nitrile rubber, butyl rubber, polyisobutylene rubber, natural rubber, and silicone rubber.

These thermoplastic resins and rubbers may be used alone or in combination of two or more.
Among these, low density, medium density, high density polyethylene, high pressure method low density polyethylene, isotactic polypropylene, syndiotactic polypropylene, poly 1-butene, poly 4-methyl-1-pentene, poly 3-methyl-1 -Butene, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, 1-butene / α-olefin copolymer, polystyrene, styrene elastomer, ethylene / vinyl acetate copolymer, ethylene / methacrylic acid Preferred forms of acrylate copolymer, ionomer, fluorine resin, rosin resin, terpene resin and petroleum resin are isotactic polypropylene, poly 1-butene, poly 4-methyl-1-pentene, ethylene / α-olefin. Copolymer, propylene / α-olefin Copolymer, 1-butene / α-olefin copolymer, ethylene / vinyl acetate copolymer, styrene elastomer, rosin resin, terpene resin, petroleum resin, ethylene / α-olefin / diene copolymer , Propylene / α-olefin / diene copolymer, 1-butene / α-olefin / diene copolymer, polybutadiene rubber, polyisoprene rubber, neoprene rubber, nitrile rubber, butyl rubber, polyisobutylene rubber, and silicone rubber are preferable.

  Examples of the rosin resin include natural rosin, polymerized rosin, modified rosin and rosin derivatives modified with maleic acid, fumaric acid, (meth) acrylic acid, and the like. Examples of the rosin derivative include the above-mentioned natural rosin, polymerized rosin or esterified product of modified rosin, phenol-modified product and esterified product thereof. Furthermore, these hydrogenated substances can also be mentioned.

  Examples of the terpene resin include resins composed of α-pinene, β-pinene, limonene, dipentene, terpene phenol, terpene alcohol, terpene aldehyde, etc., and α-pinene, β-pinene, limonene, dipentene, and the like. An aromatic modified terpene resin obtained by polymerizing aromatic monomers such as α-methylstyrene and isopropenyltoluene. Moreover, these hydrogenated substances can also be mentioned.

  Examples of the petroleum resin include an aliphatic petroleum resin mainly containing a C5 fraction of tar naphtha, an aromatic petroleum resin mainly containing a C9 fraction and a copolymer petroleum resin thereof. That is, C5 petroleum resin (resin obtained by polymerizing C5 fraction of naphtha cracked oil), C9 petroleum resin (resin obtained by polymerizing C9 fraction of naphtha cracked oil), C5C9 copolymerized petroleum resin (C5 fraction of naphtha cracked oil) And styrene / α-methylstyrene copolymer petroleum resin, α-methylstyrene polymer petroleum resin, isopropenyltoluene polymer petroleum resin, and the like. Coumarone indene resins containing styrenes, indenes, coumarone, other dicyclopentadiene, alkylphenol resins represented by condensates of p-tertiarybutylphenol and acetylene, o-xylene, p-xylene or Examples thereof include xylene-based resins obtained by reacting m-xylene with formalin.

One or more resins selected from the group consisting of rosin resins, terpene resins, and petroleum resins are preferably hydrogenated derivatives because they are excellent in weather resistance and discoloration resistance. The softening point of the resin by the ring and ball method is preferably in the range of 40 to 180 ° C. The number average molecular weight (Mn) molecular weight measured by GPC of the resin is preferably in the range of about 100 to 10,000.
A commercially available product may be used as one or more resins selected from the group consisting of rosin resins, terpene resins and petroleum resins.

<Softener>
In the mouth guard composition of the present invention, a softener may be blended as necessary within a range not impairing the object of the present invention. As the softener, a conventionally known softener that is usually used can be used. Specifically, petroleum-based substances such as process oil, lubricating oil, paraffin, liquid paraffin, polyethylene wax, polypropylene wax, petroleum asphalt and petroleum jelly; coal tars such as coal tar and coal tar pitch; castor oil, linseed oil, Fat oils such as rapeseed oil, soybean oil and coconut oil; waxes such as tall oil, beeswax, carnauba wax and lanolin; ricinoleic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, montanic acid, oleic acid and elca Fatty acids such as acids or metal salts thereof; synthetic polymers such as petroleum resins, coumarone indene resins and atactic polypropylene; ester plasticizers such as dioctyl phthalate, dioctyl adipate and dioctyl sebacate; other microcrystals WAX, and liquid polybutadiene or its modified product or hydrogenated product; and liquid Thiokol and the like.

<Other additives>
In the composition for mouth guard of the present invention, various weather resistance stabilizers, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, anti-slip agents, antiblocking agents, as long as the object of the present invention is not impaired. Antifogging agent, nucleating agent, lubricant, pigment, dye, anti-aging agent, hydrochloric acid absorbent, inorganic or organic filler, organic or inorganic foaming agent, crosslinking agent, co-crosslinking agent, crosslinking aid, adhesive, Additives such as flame retardants may be blended as necessary.

  Specific examples of additives include phenolic stabilizers, 2,6-di-t-butyl-p-cresol, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ] Methane, 4,4'-butylidenebis (6-t-butyl-m-cresol), tocopherols, ascorbic acid, dilauryl thiodipropionate, phosphoric acid stabilizer, fatty acid monoglyceride, N, N- [bis- 2-hydroxyethyl] alkylamine, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, calcium stearate, magnesium oxide, magnesium hydroxide, alumina, hydroxylation Aluminum, silica, clay, gypsum, glass fiber, titania, calcium carbonate, carbon black, etc. It is done.

<Mouthguard composition (X)>
The mouthguard composition of the present invention contains 50 to 100 parts by weight of the 4-methyl-1-pentene / propylene copolymer (A) and 50 to 0 parts by weight of a thermoplastic resin or rubber (B) ( However, the total amount of the copolymer (A) and the resin or rubber (B) is 100 parts by weight.) From the viewpoint of impact absorption of the mouth guard, the lower limit of the copolymer (A) is: The upper limit of the copolymer (A) is preferably 52 parts by weight, more preferably 55 parts by weight, particularly preferably 60 parts by weight. The amount is preferably 98 parts by weight, more preferably 95 parts by weight, particularly preferably 90 parts by weight.

The mouth guard composition of the present invention can be prepared by mixing the 4-methyl-1-pentene / propylene copolymer (A) and the thermoplastic resin or rubber (B), and optionally the additives. . As a manufacturing method, a conventionally known mixing method, for example, a method of mixing with a plast mill, a Henschel mixer, a V-blender, a ribbon blender, a tumbler blender, a kneader ruder or the like, or after mixing, a single screw extruder, a twin screw extruder, a kneader It can be produced by adopting a method of granulating or pulverizing after melt-kneading with a Banbury mixer or the like.
In addition, the mouth guard composition of the present invention preferably has the following physical properties.

  (A): Shore A hardness value (details such as measurement conditions are as described in the column of Examples described later) is 5 to 90, preferably 10 to 80, more preferably 15 to 70, Especially preferably, it is 15-65.

  The Shore A hardness value of the 4-methyl-1-pentene / propylene copolymer (A1) according to the present invention is the comonomer composition ratio of the 4-methyl-1-pentene / propylene copolymer (A), or for mouthguard. It can be changed arbitrarily depending on the mixing ratio of the components in the composition (X), and the mouth guard is excellent in flexibility when the Shore A hardness value is within the above range.

  (B): Obtained by measuring the dynamic viscoelasticity in the temperature range of −40 ° C. to + 180 ° C. and a frequency of 10 rad / s (details of measurement conditions and the like are as described in the column of Examples described later). The maximum value of the loss tangent tan δ is 0.1 to 10, preferably 0.4 to 8, more preferably 0.6 to 6, and further preferably 0.8 to 4. The temperature at which the value of tan δ is maximized is in the range of −50 ° C. to 100 ° C., preferably −30 ° C. to 50 ° C., more preferably −10 ° C. to 40 ° C. If the maximum value of tan δ is within these ranges, the mouth guard can exhibit excellent shock absorption. The maximum value of tan δ is the comonomer composition ratio of 4-methyl-1-pentene / propylene copolymer (A), or the copolymer (A), resin or rubber (B) in the mouthguard composition (X). The maximum value of tan δ can be controlled within the above range by adjusting the 4-methyl-1-pentene content to 20 to 65 mol%, for example.

(C): Rebound resilience (%) defined by the following formula (details of measurement conditions and the like are as described in the column of Examples described later) are 0 to 30% at room temperature (23 ° C.). It is preferably 0 to 20%, more preferably 0 to 15%. At 40 ° C., which is a temperature condition assuming the oral cavity, 0 to 30%, preferably 0 to 25%, more preferably 0 to 20% It is.
Rebound resilience (%) = (Rebound height) (mm) / 460 × 100

  The rebound resilience is the comonomer composition ratio of 4-methyl-1-pentene / propylene copolymer (A), or the mixture of copolymer (A), resin or rubber (B) in mouthguard composition (X). It can control by ratio etc. For example, the impact resilience can be made into the said range by making 4-methyl-1- pentene content into 20-65 mol%.

<Graft modification>
The 4-methyl-1-pentene / propylene copolymer (A) may be partly or entirely graft-modified within a range not impairing the object of the present invention, and the thermoplastic resin or rubber (B) Part or all may be graft-modified. Examples of the polar compound used for graft modification and the graft modification method include conventionally known compounds and methods. For example, the compounds and methods described in JP-A-2008-127440 can be employed.

The graft amount of the graft modified product is usually 0.1 to 40% by weight, preferably 0.2 to 30% by weight, and more preferably 0.2 to 20% by weight.
When the 4-methyl-1-pentene / propylene copolymer (A) or the thermoplastic resin or rubber (B) is graft-modified, it is advantageous in terms of compatibility or adhesiveness of the composition.

<Crosslinking>
At least a part or all of the mouthguard composition may be crosslinked with a crosslinking agent.

  There is no restriction | limiting in particular as a crosslinking agent, Sulfur, an organic peroxide, and a SiH group containing compound are mentioned. When sulfur is used, the amount is preferably 0.1 to 10 weights with respect to a total of 100 parts by weight of the copolymer (A) and the resin or rubber (B) in the mouthguard composition. Part. When the organic peroxide is used, the amount thereof is preferably 0.05 with respect to a total of 100 parts by weight of the copolymer (A) and the resin or rubber (B) in the mouthguard composition. ~ 15 parts by weight.

  Further, when the SiH group-containing compound is used, its amount is preferably 0 with respect to a total of 100 parts by weight of the copolymer (A) and the resin or rubber (B) in the mouthguard composition. 2 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, still more preferably 0.5 to 5 parts by weight. When using an SiH group-containing compound, a silane coupling agent and / or a reaction inhibitor may be added as a catalyst and optional components.

[Mouth guard seat]
The mouth guard sheet of the present invention comprises the mouth guard composition of the present invention, and the aforementioned mouth guard composition of the present invention is formed by extrusion molding, calendar molding, press molding, injection molding, vacuum molding, pressure molding, It is formed by processing into a sheet by an arbitrary forming method such as vacuum / pressure forming.

[Mouth guard]
The mouth guard of the present invention comprises the mouth guard composition of the present invention, and is formed from the aforementioned mouth guard composition or mouth guard sheet of the present invention.

  The mouth guard of the present invention is prepared in the same manner as the conventional mouth guard except that the material is the mouth guard composition or mouth guard sheet of the present invention, for example, WO 2002/98521. It can be produced by the method described in JP 2010-131181. More specifically, the mouth guard sheet is heated until it softens, and a mouth guard is manufactured along the dental model or jaw model, and a concave mold is created using the dental model or jaw model. However, a mouth guard can be produced by a method for producing a mouth guard by injecting the mouth guard composition therein.

  Since the mouth guard of the present invention is composed of the composition for mouth guard of the present invention having excellent characteristics as described above, it has the following advantages.

・ Because the material has high shock absorption, it is not only excellent in wearing feeling even if it is thinner than conventional products, but also excellent in shock absorption.
-Since the rebound resilience of the material is low, it has an excellent fit, especially when it is tightly tightened.
-Since the Shore A hardness of the material is low, it follows the unevenness of the teeth and is excellent in wearing comfort.
-Light weight due to low material density.
-The material has high wear resistance and excellent durability.
・ There is no odor unlike mouth guard made of styrene elastomer.
-Since the softening temperature is low, it is excellent in moldability compared to EVA mouth guards.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these Examples.

[Measurement conditions]
The measurement conditions of the physical properties in the examples are as follows.

〔composition〕
The 4-methyl-1-pentene and propylene contents in the polymer were measured by ¹³ C-NMR with the following apparatus and conditions. Using an ECP500 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd., a mixed solvent of orthodichlorobenzene / heavy benzene (80/20% by volume) as a solvent, sample concentration 55 mg / 0.6 mL, measurement temperature 120 ° C., observation nucleus ¹³ C (125 MHz), sequence is single pulse proton decoupling, pulse width is 4.7 μs (45 ° pulse), repetition time is 5.5 seconds, integration number is 10,000 times or more, 27.50 ppm as standard for chemical shift Measured as a value.

〔density〕
The density of the copolymer (A) was calculated from the weight of each sample measured in water and in air using ALFA MIRAGE electronic hydrometer MD-300S according to ASTM D 1505 (in-water replacement method).

[Melting point (Tm)]
The melting point (Tm) of the polymer was measured with a differential scanning calorimeter (DSC) using a DSC220C apparatus manufactured by Seiko Instruments Inc. Samples 7-12 mg obtained from the polymerization were sealed in an aluminum pan and heated from room temperature to 200 ° C. at 10 ° C./min. The sample was held at 200 ° C. for 5 minutes to completely melt and then cooled to −50 ° C. at 10 ° C./min. After 5 minutes at −50 ° C., the sample was heated a second time to 200 ° C. at 10 ° C./min. The peak temperature in the second heating test was adopted as the melting point (Tm).

[Intrinsic viscosity]
The intrinsic viscosity [η] was measured at 135 ° C. using a decalin solvent.
[Molecular weight (Mw, Mn) / Molecular weight distribution (Mw / Mn)]
The molecular weight of the copolymer (A) was measured using a liquid chromatograph: Waters ALC / GPC 150-C plus (integrated refractometer detector), and two columns of GMH6-HT manufactured by Tosoh Corporation and GMH6. -Two HTLs were connected in series, and o-dichlorobenzene was used as a mobile phase medium, and measurement was performed at a flow rate of 1.0 ml / min and 140 ° C.

  Mw / Mn value, Mw value, and Mn value were calculated by analyzing the obtained chromatogram by a known method using a calibration curve using a standard polystyrene sample. The measurement time per sample was 60 minutes.

[Methyl acetate extraction amount]
The polymer was collected in a Soxhlet extractor, heated and refluxed under methyl acetate, and the amount of polymer before and after the reflux was weighed and adopted as the extraction amount (%).

[Methods for producing various measurement press sheets]
Each composition of the example and the comparative example was formed into a sheet at a pressure of 10 MPa using a hydraulic hot press machine manufactured by Shindo Metal Industry Co., Ltd. set at 190 ° C. In the case of a sheet having a thickness of 1 to 3 mm (spacer shape; 80 × 80 × 0.5 to 3 mm, 4 pieces on a 240 × 240 × 2 mm thick plate), the remaining heat is about 5 to 7 minutes, and 1 to 2 at 10 MPa. After pressurizing for a minute, using another hydraulic hot press machine manufactured by Shinfuji Metal Industry Co., Ltd. set to 20 ° C., the sample was compressed at 10 MPa and cooled for about 5 minutes to prepare a measurement sample. A 5 mm thick brass plate was used as the hot plate. Samples prepared by the above method were used for various physical property evaluation samples.

[Shore A hardness]
In the measurement of Shore A hardness (according to JIS K6253), a press sheet having a thickness of 3 mm was used as a measurement sample, and the scale was read 15 seconds after the pressing needle contact.

(Dynamic viscoelasticity)
A press sheet having a thickness of 3 mm was prepared, and a strip of 45 mm × 10 mm × 3 mm necessary for dynamic viscoelasticity measurement was cut out. The temperature dependence of dynamic viscoelasticity up to -40 to 180 ° C. was measured at a frequency of 10 rad / s using MTON 301 manufactured by ANTON Paar, and the loss tangent (tan δ) due to the glass transition temperature was the peak value (maximum value). ) (Hereinafter also referred to as “peak temperature”), and the value of loss tangent (tan δ) at that time.

[Tensile modulus (YM), tensile elongation at break (EL), tensile yield stress (YS), tensile stress at break (TS)]
Tensile modulus (YM), tensile elongation at break (EL), tensile yield stress (YS), and tensile stress at break (TS), which are tensile properties, were evaluated from a 1 mm thick press sheet obtained by the above method. The punched JISK7113 type 2 test piece 1/2 was used as an evaluation sample, and the test was carried out in a 23 ° C. atmosphere at a tensile speed of 30 mm / min.

[Rebound resilience]
A press sheet having a thickness of 6 mm was prepared, and in accordance with JIS K6400, a rebound height L (mm) when a hard ball of 16.310 g was dropped from a height of 460 mm onto the press sheet was measured. The impact resilience defined by the following formula was determined.
Rebound resilience (%) = L (mm) / 460 × 100

(Stress relaxation measurement)
In the measurement of the stress relaxation rate, a measurement sample having a thickness of 12 mm was obtained by stacking four press sheets having a thickness of 3 mm. In the stacking direction of the measurement sample, a compression jig having a tip diameter of 5 mmφ used in a bending test or the like was pressed at 23 ° C. at a speed of 10 mm / min to compress the measurement sample. When the load reaches 500 N (about 50 kgf) (hereinafter referred to as “maximum load”), which corresponds to the force of an adult male biting the back teeth, further compression is stopped, and the load after being placed for 5 minutes (relaxed load) ) And the ratio (post-relaxation load / maximum load) was defined as the stress relaxation rate (%).

[Example 1]
750 ml of 4-methyl-1-pentene was charged at 23 ° C. into a SUS autoclave with a stirring blade having a capacity of 1.5 liters sufficiently purged with nitrogen. The autoclave was charged with 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAl), and the stirrer was rotated. Next, the autoclave was heated to an internal temperature of 30 ° C. and pressurized with propylene so that the total pressure was 0.74 MPaG. Subsequently, methylaluminoxane prepared in advance, 1 mmol in terms of Al, diphenylmethylene (1-methyl-3-t-butyl-cyclopentadienyl) (2,7-di-t-butyl-fluorenyl) A toluene solution containing 0.35 ml of zirconium dichloride in an amount of 0.005 mmol was pressed into the autoclave with nitrogen to initiate polymerization. Thereafter, the temperature of the autoclave was adjusted to 60 ° C. for 60 minutes. Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave with nitrogen to stop the polymerization, and the autoclave was depressurized to atmospheric pressure. Acetone was poured into the reaction solution with stirring. The resulting rubbery polymer containing the solvent was dried at 130 ° C. under reduced pressure for 12 hours. The obtained polymer was 56.3 g, and the propylene content in the polymer was 75.3 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] was 1.5 dl / g. The molecular weight distribution obtained from GPC was Mw = 287000, Mn = 144000, and Mw / Mn = 2.0. The physical properties of the obtained polymer are shown in Table 1.

[Example 2]
Polymerization was carried out in the same manner as in Example 1 except that propylene was pressurized so that the total pressure in the polymerization vessel was 0.68 MPaG. The obtained polymer was 45.9 g, and the propylene content in the polymer was 68.9 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] was 1.5 dl / g. The molecular weight distribution obtained from GPC was Mw = 267000, Mn = 1340, Mw / Mn = 2.0. The physical properties of the obtained polymer are shown in Table 1.

Example 3
Polymerization was carried out in the same manner as in Example 1 except that propylene was pressurized so that the total pressure in the polymerization vessel was 0.35 MPaG. The obtained polymer was 46.9 g, and the propylene content in the polymer was 52.7 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] = 1.4 dl / g. The molecular weight distribution obtained from GPC was Mw = 277000, Mn = 132000, Mw / Mn = 2.1. The physical properties of the obtained polymer are shown in Table 1.

Example 4
Polymerization was carried out in the same manner as in Example 1 except that propylene was pressurized so that the total pressure in the polymerization vessel was 0.20 MPaG. The obtained polymer was 35.5 g, and the propylene content in the polymer was 40.0 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] = 1.4 dl / g. The molecular weights obtained from GPC were Mw = 272000, Mn = 131000, Mw / Mn = 2.1. The physical properties of the obtained polymer are shown in Table 1.

Example 5
Polymerization was carried out in the same manner as in Example 1 except that propylene was pressurized so that the total pressure in the polymerization vessel was 0.15 MPaG. The obtained polymer was 46.9 g, and the propylene content in the polymer was 38.0 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] = 1.4 dl / g. The molecular weight distribution obtained from GPC was Mw = 295000, Mn = 142000, Mw / Mn = 2.1. The physical properties of the obtained polymer are shown in Table 1.

Example 6
Polymerization was performed in the same manner as in Example 1 except that propylene was pressurized so that the total pressure in the polymerization vessel was 0.10 MPaG. The obtained polymer was 29.7 g, and the propylene content in the polymer was 28.1 mol%. The Tm of the polymer was not observed, and the intrinsic viscosity [η] = 1.4 dl / g. The molecular weight distribution obtained from GPC was Mw = 289000, Mn = 138000, and Mw / Mn = 2.1. The physical properties of the obtained polymer are shown in Table 1.

[Comparative Example 1]
Polymerization was carried out in the same manner as in Example 1 except that 100 ml of 4-methyl-1-pentene in the polymerization vessel and 650 ml of hexane as a polymerization solvent were added and pressurized with propylene so that the total pressure became 0.68 MPaG. . The obtained polymer was 21.2 g, and the propylene content in the polymer was 90.0 mol%. The polymer had a Tm of 69.1 ° C. and an intrinsic viscosity [η] of 1.31 dl / g. The molecular weight distribution obtained from GPC was Mw = 262000, Mn = 133000, Mw / Mn = 2.0. The physical properties of the obtained polymer are shown in Table 1.

[Comparative Example 2]
Polymerization was carried out in the same manner as in Example 1 except that 750 ml of 4-methyl-1-pentene in the polymerization vessel was pressurized with propylene so that the total pressure was 0.05 MPaG, and the polymerization temperature was 60 ° C. The obtained polymer was 21.2 g, and the propylene content in the polymer was 9.8 mol%. The polymer had a Tm of 144.1 ° C. and an intrinsic viscosity [η] of 1.45 dl / g. The molecular weight distribution obtained from GPC was Mw = 296000, Mn = 148000, and Mw / Mn = 2.1. The physical properties of the obtained polymer are shown in Table 1.

[Comparative Example 3]
A commercially available hydrogenated styrene / isoprene / styrene copolymer (manufactured by Kuraray Co., Ltd., Hibler 5127) was used. The MFR at 190 ° C. was 5 g / 10 min. Table 1 shows the physical properties of the comparative examples. It turns out that it is inferior to lightness from a density value.

[Comparative Example 4]
A commercially available hydrogenated styrene / butadiene / styrene copolymer (Asahi Kasei Co., Ltd., Tuftec H1062) was used. The MFR at 230 ° C. was 17 g / 10 min. Table 1 shows the physical properties of the comparative examples. It turns out that it is inferior to lightness from a density value.

[Comparative Example 5]
A commercially available ethylene / α-olefin copolymer (Mitsui Chemicals, Tuffmer P0680) was used. The MFR at 190 ° C. was 0.8 g / 10 min. Table 1 shows the physical properties of the comparative examples. It can be seen from the values of tan δ and impact resilience that the stress absorption is poor.

[Comparative Example 6]
A commercially available ethylene / vinyl acetate copolymer (Mitsui / DuPont Polychemical Co., Ltd., Evaflex EV250) was used. The MFR at 190 ° C. was 15 g / 10 min. Table 1 shows the physical properties of the comparative examples. It can be seen that the density value is inferior in lightness and the Shore A hardness is inferior in flexibility.

表１から明らかなように、実施例に示した本発明によるマウスガード用組成物（共重合体（Ａ））は、低硬度であり、ｔａｎδの値が高く、反発弾性率が低い。これらの特性より、該マウスガード用組成物は耐衝撃性に優れていることがわかる。さらに従来のＥＶＡやスチレン系エラストマーと比較しても高い応力緩和率を示すことから、外部衝撃を緩和する能力に優れたマウスガードを該マウスガード用組成物から製造できることがわかる。

As is apparent from Table 1, the mouthguard composition (copolymer (A)) according to the present invention shown in the examples has a low hardness, a high tan δ value, and a low rebound resilience. From these characteristics, it can be seen that the composition for mouth guard is excellent in impact resistance. Furthermore, since it shows a high stress relaxation rate even compared with conventional EVA and styrene-based elastomer, it can be seen that a mouth guard having an excellent ability to alleviate external impact can be produced from the mouth guard composition.

Example 7
90 parts by weight of the 4-methyl-1-pentene / propylene copolymer obtained in Example 1 and 10 parts by weight of polypropylene F107 manufactured by Prime Polymer Co., Ltd. were blended as a thermoplastic resin. Furthermore, 1000 ppm of hindered phenolic antioxidant Irganox 1076 manufactured by Ciba Japan Co., Ltd., 1000 ppm of phosphorous processing heat stabilizer Irgafos 168, and calcium stearate manufactured by NOF Corporation After blending 500 ppm, using a lab plast mill (biaxial batch type melt kneader) manufactured by Toyo Seiki Co., Ltd., at a set temperature of 200 ° C., resin charge 40 g (apparatus batch volume = 60 cm ³ ), 50 rpm, after 5 minutes of melt kneading The mixture was cooled with a cooling press set at 20 ° C. to prepare a mouth guard composition.

  A mouth guard sheet was prepared by molding the sheet at a pressure of 10 MPa using a hot press set at 190 ° C. using the above mouth guard composition. Table 2 shows the results of various physical properties.

Example 8
80 parts by weight of the 4-methyl-1-pentene / propylene copolymer obtained in Example 1 and 20 parts by weight of polypropylene F327 manufactured by Prime Polymer Co., Ltd. were blended as a thermoplastic resin. Furthermore, 1000 ppm of hindered phenolic antioxidant Irganox 1076 manufactured by Ciba Japan Co., Ltd., 1000 ppm of phosphorous processing heat stabilizer Irgafos 168, and calcium stearate manufactured by NOF Corporation After blending 500 ppm, using a lab plast mill (biaxial batch type melt kneader) manufactured by Toyo Seiki Co., Ltd., at a set temperature of 200 ° C., resin charge 40 g (apparatus batch volume = 60 cm ³ ), 50 rpm, after 5 minutes of melt kneading The mixture was cooled with a cooling press set at 20 ° C. to prepare a mouth guard composition.

  A mouth guard sheet was prepared by molding the sheet at a pressure of 10 MPa using a hot press set at 190 ° C. using the above mouth guard composition. Table 2 shows the results of various physical properties.

Example 9
60 parts by weight of 4-methyl-1-pentene / propylene copolymer obtained in Example 3 and 40 parts by weight of ethylene / α-olefin copolymer TAFMER P0680 manufactured by Mitsui Chemicals, Inc. as a thermoplastic resin did. Furthermore, 1000 ppm of hindered phenolic antioxidant Irganox 1076 manufactured by Ciba Japan Co., Ltd., 1000 ppm of phosphorous processing heat stabilizer Irgafos 168, and calcium stearate manufactured by NOF Corporation After blending 500 ppm, using a lab plast mill (biaxial batch type melt kneader) manufactured by Toyo Seiki Co., Ltd., at a set temperature of 200 ° C., resin charge 40 g (apparatus batch volume = 60 cm ³ ), 50 rpm, after 5 minutes of melt kneading The mixture was cooled with a cooling press set at 20 ° C. to prepare a mouth guard composition.

  A mouth guard sheet was prepared by molding the sheet at a pressure of 10 MPa using a hot press set at 190 ° C. using the above mouth guard composition. Table 2 shows the results of various physical properties.

[Comparative Example 7]
40 parts by weight of the 4-methyl-1-pentene / propylene copolymer obtained in Example 1 and 60 parts by weight of polypropylene F107 manufactured by Prime Polymer Co., Ltd. were blended as a thermoplastic resin. Furthermore, 1000 ppm of hindered phenolic antioxidant Irganox 1076 manufactured by Ciba Japan Co., Ltd., 1000 ppm of phosphorous processing heat stabilizer Irgafos 168, and calcium stearate manufactured by NOF Corporation After blending 500 ppm, using a lab plast mill (biaxial batch type melt kneader) manufactured by Toyo Seiki Co., Ltd., at a set temperature of 200 ° C., resin charge 40 g (apparatus batch volume = 60 cm ³ ), 50 rpm, after 5 minutes of melt kneading The mixture was cooled with a cooling press set at 20 ° C. to prepare a mouth guard composition.

  A mouth guard sheet was prepared by molding the sheet at a pressure of 10 MPa using a hot press set at 190 ° C. using the above mouth guard composition. Table 2 shows the results of various physical properties.

[Comparative Example 8]
A mouth guard material (trade name: GC Impact Guard, manufactured by GC Corporation) using a commercially available styrene / α-olefin block copolymer was used. Table 2 shows the physical properties of the comparative examples.

[Comparative Example 9]
A mouth guard (trade name: + α mouth guard, manufactured by Sun Medical Co., Ltd.) using a commercially available ethylene / vinyl acetate copolymer was used. Table 2 shows the physical properties of the comparative examples.

表２からも明らかなように、実施例に示した本発明によるマウスガード用樹脂組成物は、低硬度であり、ｔａｎδの値が高く、引張強度に優れ、さらに反発弾性率が低い。この特性より、該マウスガード用組成物は耐衝撃性、耐久性に優れていることがわかる。

As is clear from Table 2, the mouthguard resin composition according to the present invention shown in the examples has low hardness, high tan δ value, excellent tensile strength, and low rebound resilience. From this characteristic, it can be seen that the mouthguard composition is excellent in impact resistance and durability.

Claims (4)

The structural unit (i) derived from 15 to 75 mol% of 4-methyl-1-pentene and the structural unit (ii) derived from 25 to 85 mol% of propylene (provided that the proportion and configuration of the structural unit (i) 50 to 100 parts by weight of 4-methyl-1-pentene / propylene copolymer (A) consisting of the proportion of the unit (ii) is 100 mol%, and a thermoplastic resin or rubber (B ) 50 to 0 parts by weight (however, the total amount of the copolymer (A) and the resin (B) is 100 parts by weight.)
A composition for mouth guard characterized by containing.   The said 4-methyl-1- pentene propylene copolymer (A) contains 50 to 98 parts by weight, and the thermoplastic resin or rubber (B) contains 50 to 2 parts by weight. The composition for mouth guard as described.   A mouth guard sheet comprising the mouth guard composition according to claim 1.   A mouth guard comprising the composition for mouth guard according to claim 1 or 2.