JP2014037551A - Rubber composition for side wall and tire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition having high elasticity, high tensile strength and excellent in heat generation properties and fatigability.SOLUTION: A rubber composition contains 0.1 to 50 pts.wt. of a polyamide elastomer (B) having a melting point of 100 to 180°C and 1 to 100 pts.wt. of an inorganic reinforcing agent (C) per 100 pts.wt. of a vulcanizable rubber (A), and a soft segment of the polyamide elastomer (B) is polyether.

Description

  The present invention relates to a rubber composition comprising a vulcanizable rubber, a polyamide elastomer having a melting point of 100 to 180 ° C. and an inorganic reinforcing agent, a rubber composition for a base tread, a rubber composition for a chafer, and a rubber composition for a sidewall. About.

  In recent years, attention has been paid to technologies for reducing fuel consumption of automobiles, in particular, reducing fuel consumption of tires, in consideration of the environment that is demanded worldwide. Generally, the fuel consumption of a tire is reduced by reducing the amount of reinforcing agent that restrains the polymer and reducing the hysteresis of rubber. However, reducing the amount of the reinforcing agent not only reduces the reinforcing property of the tire, but also causes a problem that the hardness decreases.

  Therefore, there is a method of reducing the hysteresis of the rubber by increasing the amount of the crosslinking agent, but there is a problem that the rubber itself becomes brittle and the crack growth property is promoted, and further improvement is required.

  Further, in order to solve the above-described problems, it is necessary to improve the reinforcement of the rubber itself without reducing the reinforcement even if the amount of the reinforcing agent is reduced. As a measure therefor, Patent Document 1 describes that a reinforcing effect is maintained even if the reinforcing agent is reduced by using a butadiene rubber that is changed to syndiotactic polybutadiene having a high reinforcing property. However, with the method using syndiotactic polybutadiene, it has been difficult to improve the target fuel efficiency, elongation at break, balance of hardness, etc. comprehensively.

Patent Document 2 discloses a rubber composition in which a thermoplastic polyamide refined (or shortened fiber) and silica particles are blended with rubber to improve the wear resistance of a roll of OA equipment. Further, Patent Document 3 discloses a rubber composition for a seismic isolation laminate that absorbs vibration energy efficiently with a high elastic modulus by blending natural rubber or the like with a polyamide elastomer and fine carbon black.
JP 2006-124503 A JP 7-224189 A Japanese Patent Laid-Open No. 10-237221

  However, generally, when a resin or fiber is blended with rubber, there is a problem in that although it becomes highly elastic, the tensile strength is lowered, and heat generation and fatigue are deteriorated. In addition, although any desired effect can be obtained with any of the techniques, there is a problem that the tensile strength and the like are reduced, and when it is used for a tire member, particularly a base tread, a more practical one is required. Yes.

  Furthermore, the durability of the bead portion that comes into contact with the belt portion or the rim of a heavy load tire such as a truck or bus is particularly insufficient among the tires, and particularly the bead portion needs to have sufficient durability. Further, a chafer is blended as a hard rubber part between the rim and the bead part for the purpose of suppressing deformation of the bead part, but it is not sufficient in terms of hardness, elongation at break and the like.

  Further, among the tires, particularly, the side wall rubber of heavy-duty tires such as trucks and buses, problems such as bending crack growth and hardness remain, and more practical ones have been demanded.

  Accordingly, a first object of the present invention is to provide a rubber composition having high elasticity, high tensile strength, and excellent heat generation and fatigue.

  The present invention also provides a rubber composition for a base tread, a base tread, and a tire including the same, having high elasticity, high tensile strength, high elongation at break, excellent heat generation and fatigue, and excellent balance between them. The second purpose is to do.

  Furthermore, a third object of the present invention is to provide a chafer rubber composition, chafer, and a tire including the same, which are excellent in exothermic property, elongation at break, hardness, and fatigue properties and are well balanced. And

  Furthermore, the present invention provides a rubber composition for a sidewall, a sidewall, and a tire including the same, which are excellent in exothermic property, chip cut resistance, hardness, fatigue property, and flex crack growth property, and in an excellent balance thereof. The fourth purpose is to provide it.

  In order to achieve the first object described above, the present inventors have conducted extensive research, and as a result, polyamide elastomer (B) having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). ) By containing 0.1 to 50 parts by weight and 1 to 100 parts by weight of the inorganic reinforcing agent (C), it is possible to obtain a rubber composition having high elasticity, high tensile strength, and excellent exothermic and fatigue properties. I found out that I can do it.

  That is, the present invention is based on 100 parts by weight of vulcanizable rubber (A), 0.1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 1 to 100 parts by weight of an inorganic reinforcing agent (C). A rubber composition characterized by containing a part.

  Moreover, in order to achieve the above second object, the present inventors have made extensive studies, and as a result, polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1-50 parts by weight and inorganic reinforcing agent (C) 20-70 parts by mass, the inorganic reinforcing agent (C) contains at least carbon black and silica, and the silica in the inorganic reinforcing agent (C) When the blending amount is 80% by mass or less, it is possible to obtain a rubber composition for a base tread having high elasticity, large tensile strength and elongation at break, excellent exothermic property and fatigue property, and excellent balance between them. I found.

  That is, the present invention comprises 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 70 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of vulcanizable rubber (A). A rubber composition for a base tread, wherein the inorganic reinforcing agent (C) contains at least carbon black and silica, and the amount of silica in the inorganic reinforcing agent (C) is 80% by mass or less. . Moreover, this invention is a base tread containing the said rubber composition for base treads. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire, which have the said base tread.

  Furthermore, in order to achieve the above third object, the present inventors have conducted extensive research and have found that a polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1 to 50 parts by weight and inorganic reinforcing agent (C) 60 to 100 parts by weight, JIS-A hardness is 70 to 90, and elongation at break in a tensile test is 180% or more. It has been found that a rubber composition for chafers can be obtained which is excellent in elongation at break, hardness and fatigue properties and in an excellent balance between them.

  That is, the present invention comprises 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 60 to 100 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of vulcanizable rubber (A). It is a rubber composition for chafers containing JIS-A hardness of 70 to 90 and elongation at break in a tensile test of 180% or more. Moreover, this invention is a chafer containing the said rubber composition for chafers. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire which have the said chafer.

  Furthermore, in order to achieve the fourth object described above, the present inventors have made extensive studies, and as a result, polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1-50 parts by weight and inorganic reinforcing agent (C) 20-60 parts by weight, JIS-A hardness 55-75, exothermic, chip-cut resistance, hardness, fatigue and It has been found that a rubber composition for a sidewall can be obtained that has excellent flex crack growth and is well balanced.

  That is, the present invention contains 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 60 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of the vulcanizable rubber (A). And a rubber composition for a sidewall, having a JIS-A hardness of 55 to 75. Moreover, this invention is a side wall containing the said rubber composition for side walls. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire which have the said sidewall.

  As described above, according to the present invention, it is possible to provide a rubber composition having high elasticity, high tensile strength, and excellent heat generation and fatigue properties.

  The present invention also provides a rubber composition for a base tread, a base tread, and a tire including the same, having high elasticity, high tensile strength, high elongation at break, excellent heat generation and fatigue, and excellent balance between them. can do.

  Furthermore, the present invention can provide a rubber composition for chafers, a chafer, and a tire including the same, which are excellent in exothermic property, elongation at break, hardness, and fatigue properties and are well balanced.

  Furthermore, the present invention provides a rubber composition for a sidewall, a sidewall, and a tire including the same, which are excellent in exothermic property, chip cut resistance, hardness, fatigue property, and flex crack growth property, and in an excellent balance thereof. Can be provided.

Rubber composition:
Next, the rubber composition according to the present invention will be described.

[Vulcanizable rubber (A)]
The vulcanizable rubber used in the rubber composition according to the present invention is not particularly limited, and any known rubber can be used, and a diene rubber can be preferably used. For example, diene monomers such as natural rubber, butadiene rubber (BR), syndiotactic-1,2-polybutadiene (SPB) -containing butadiene rubber, SPB-containing natural rubber, isoprene rubber, butyl rubber, and chloroprene rubber. Polymer; Acrylonitrile-diene copolymer rubber such as acrylonitrile butadiene rubber (NBR), nitrile chloroprene rubber, and nitrile isoprene rubber; Styrene-diene copolymer rubber such as styrene butadiene rubber (SBR), styrene chloroprene rubber, and styrene isoprene rubber And ethylene propylene diene rubber (EPDM) and the like. Among these, butadiene rubber, syndiotactic-1,2-polybutadiene-containing butadiene rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, natural rubber, and isoprene rubber are preferable. These can be used alone or in combination of two or more.

  Syndiotactic-1,2-polybutadiene-containing butadiene rubber includes 1,3-butadiene syndiotactic-1,2 polymerized (SPB) and 1,3-butadiene cis-1,4 polymerized. It can be obtained by mixing (for example, Japanese Patent Publication No. 3-63566).

Particularly preferred among SPB-containing butadiene rubbers is a specific syndiotactic compound in which the average length of crystal fibers is 90 nm or more per 25 μm ² and the melting point is 170 ° C. or more. 1,2-polybutadiene crystal fiber 1-30 wt%, cis-polybutadiene rubber 99-70 wt%, and unsaturated polymer material having at least one unsaturated double bond per repeating unit 0-20 wt% Vinyl cis-polybutadiene rubber (for example, WO 2006-54808).

  Moreover, a vulcanizing agent and a vulcanization accelerator can be added to the vulcanizable rubber (A). Examples of the vulcanizing agent include sulfur, a compound that generates sulfur by heating, an organic peroxide, a metal oxide such as magnesium oxide, a polyfunctional monomer, and a silanol compound. Examples of the compound that generates sulfur by heating include tetramethyl thiuram disulfide and tetraethyl thiuram disulfide.

  Examples of the vulcanization accelerator include aldehydes, ammonia, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, and xanthates, and more specifically, tetramethylthiuram. Disulfide (TMTD), N-oxydiethylene-2-benzothiazolylsulfenamide (OBS), N-cyclohexyl-2-benzothiazylsulfenamide (CBS), dibenzothiazyl disulfide (MBTS), 2-mercaptobenzo Examples include thiazole (MBT), zinc di-n-butyldithiocarbide (ZnBDC), and zinc dimethyldithiocarbide (ZnMDC).

  In addition, if necessary, known additives usually used in rubber compositions such as anti-aging agent, filler, process oil, zinc white, stearic acid and the like can be blended.

  Anti-aging agents include amine / ketone-based, imidazole-based, amine-based, phenol-based, sulfur-based and phosphorus-based anti-aging agents. More specifically, as an anti-aging agent, phenol-based 2,6-di-tert-butyl-p-cresol (BHT), phosphorus-based trinonylphenyl phosphite (TNP), sulfur-based 4.6-bis (Octylthiomethyl) -o-cresol, dilauryl-3,3′-thiodipropionate (TPL) and the like.

  Fillers include inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, Lissajous, and diatomaceous earth, recycled fillers, and fillers such as powdered rubber. Process oils include aromatics, Examples include naphthenic and paraffinic process oils.

[Polyamide elastomer (B)]
In the polyamide elastomer (B) having a melting point of 100 to 180 ° C. used in the rubber composition according to the present invention, the hard segment is a polyamide, and the soft segment is a multi-block copolymer using polyether or polyester. The soft segment is preferably a polyether. The amide component is nylon 6,66,610,11,12, etc., representative examples of polyethers are diol poly (oxytetramethylene) glycol, poly (oxypropylene) glycol, etc., and typical examples of polyesters are poly (ethylene adipate). ) Glycol, poly (butylene-1,4 adipate) glycol, and the like. Examples of such polyamide elastomer (B) include polyether polyamide elastomers described in Japanese Patent No. 4123475 and polyether ester / amide block copolymers described in Japanese Patent Publication No. 56-45419.

  It is not preferable to use a polyamide elastomer having a melting point lower than 100 ° C. because it is inferior in heat resistance, and a melting point higher than 180 ° C. is not preferable because it does not melt and disperse when kneaded with rubber.

  The melting point of the polyamide elastomer (B) used in the present invention is 100 ° C to 180 ° C, more preferably 120 ° C to 170 ° C. The melting point can be adjusted by, for example, the ratio between the hard segment and the soft segment.

  The polyamide elastomer (B) used in the present invention preferably has a hardness (Shore D) of 30 to 65, and more preferably 35 to 60. The hardness can be adjusted by, for example, the ratio between the hard segment and the soft segment.

  Further, in the present invention, the amount of the polyamide elastomer (B) is 0.1 to 50 parts by weight, preferably 0.2 to 40 parts by weight, more preferably 0 to 100 parts by weight of the vulcanizable rubber (A). .3 to 30 parts by weight, particularly preferably 0.5 to 20 parts by weight. If the amount of the polyamide elastomer is less than 0.1 parts by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited.

  As the polyamide elastomer (B), in particular, a polyamide-forming monomer [that is, an aminocarboxylic acid compound (D1) and / or a lactam compound (D2)], an XYX type triblock polyetherdiamine compound (E) (Y is a polyoxy And a polyether polyamide elastomer obtained by polymerizing a dicarboxylic acid (F).

  In the polyether polyamide elastomer, the terminal carboxylic acid or carboxy group contained in the polyamide-forming monomer, XYX type triblock polyether diamine (E) and dicarboxylic acid (F) and the terminal amino group are approximately equimolar. A ratio such that

  In particular, when one end of the polyamide-forming monomer is an amino group and the other end is a carboxylic acid or a carboxy group, the XYX type triblock polyether diamine (E) and the dicarboxylic acid (F) are XYX type triblock poly The ratio is preferably such that the amino group of the ether diamine (E) and the carboxy group of the dicarboxylic acid (F) are approximately equimolar.

[Aminocarboxylic acid compound (D1) and lactam compound (D2)]
Next, the aminocarboxylic acid compound (D1) and the lactam compound (D2) will be described. The aminocarboxylic acid compound (D1) used in the present invention is a compound represented by the following formula (1).
^{_{H 2 N-R 1 -COOH (}} 1)

Here, R ¹ represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 2 to 20 carbon atoms or an alkylene group having 2 to 20 carbon atoms, More preferably, the hydrocarbon group having 3 to 18 carbon atoms or the alkylene group having 3 to 18 carbon atoms, more preferably the hydrocarbon group having 4 to 15 carbon atoms or the alkylene group having 4 to 15 carbon atoms, Particularly preferably, it represents the hydrocarbon group having 10 to 15 carbon atoms or the alkylene group having 10 to 15 carbon atoms.

The lactam compound (D2) used in the present invention is a compound represented by the following formula (2). Here, R ² represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 3 to 20 carbon atoms or an alkylene group having 3 to 20 carbon atoms, More preferably, the hydrocarbon group having 3 to 18 carbon atoms or the alkylene group having 3 to 18 carbon atoms, more preferably the hydrocarbon group having 4 to 15 carbon atoms or the alkylene group having 4 to 15 carbon atoms, Particularly preferably, it represents the above hydrocarbon group having 10 to 15 carbon atoms or an alkylene group having 10 to 15 carbon atoms.

  As the aminocarboxylic acid compound (D1) and the lactam compound (D2), at least one aliphatic or alicyclic group selected from ω-aminocarboxylic acid, lactam, or a compound synthesized from diamine and dicarboxylic acid and salts thereof And / or polyamide-forming monomers containing aromatics are used.

  Specific examples of ω-aminocarboxylic acids include carbon numbers such as 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 10-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples thereof include 5 to 20 aliphatic ω-aminocarboxylic acids.

  Specific examples of the lactam include ε-caprolactam, ω-enantolactam, ω-undecalactam, ω-dodecalactam, and aliphatic lactam having 5 to 20 carbon atoms such as 2-pyrrolidone.

  Examples of the diamine synthesized from diamine and dicarboxylic acid and salts thereof include at least one diamine compound selected from aliphatic diamine, alicyclic diamine and aromatic diamine, or derivatives thereof. . Examples of the dicarboxylic acid include at least one dicarboxylic acid compound selected from aliphatic dicarboxylic acid, alicyclic dicarboxylic acid and aromatic dicarboxylic acid, or derivatives thereof. In particular, by using a combination of an aliphatic diamine compound and an aliphatic dicarboxylic acid compound, a polyether polyamide elastomer having a low specific gravity, large tensile elongation, excellent impact resistance, and good melt moldability can be obtained. it can.

  The molar ratio of diamine to dicarboxylic acid (diamine / dicarboxylic acid) is preferably in the range of 0.9 to 1.1, more preferably in the range of 0.93 to 1.07, and in the range of 0.95 to 1.05. Is more preferable, and the range of 0.97 to 1.03 is particularly preferable. If this molar ratio is within the above range, high molecular weight can be easily achieved.

  Specific examples of the diamine include ethylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2, Examples thereof include diamine compounds such as aliphatic diamines having 2 to 20 carbon atoms such as 2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, and 3-methylpentamethylenediamine.

  Specific examples of the dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as dodecanedioic acid. The dicarboxylic acid compound can be mentioned.

[XYX type triblock polyether diamine (E)]
XYX type triblock polyether diamine (E) is a compound represented by the following formula (3), and after making propylene oxide by adding propylene oxide to both ends of poly (oxytetramethylene) glycol and the like, Polyether diamine produced by reacting ammonia at the end of this polypropylene glycol can be used.

  In the above formula (3), x and z are 1 to 20, preferably 1 to 18, more preferably 1 to 16, more preferably 1 to 14, particularly preferably 1 to 12, and y is 4 to 50. , Preferably 5 to 45, more preferably 6 to 40, more preferably 7 to 35, and particularly preferably 8 to 30. Further, as a combination of x, y and z, x is in the range of 2 to 6, y is in the range of 6 to 12, z is in the range of 1 to 5, or x is in the range of 2 to 10, and y is in the range of 13 to Preferred examples include a range of 28 and a combination of z in the range of 1-9.

  In the XYX type triblock polyether diamine (E), when x and z are each smaller than the above range, the resulting elastomer is inferior in transparency, which is not preferable. When y is smaller than the above range, rubber elasticity Is not preferable because of a low. Moreover, when x and z are larger than the said range, or when y is larger than the said range, since compatibility with a polyamide component becomes low and a tough elastomer is difficult to be obtained, it is not preferable.

  Specific examples of the XYX type triblock polyether diamine (E) include XTJ-533 manufactured by HUNTSMAN (USA) (in the general formula (3), x is approximately 12, y is approximately 11, and z is approximately 11), XTJ-536 (In general formula (3), x is about 8.5, y is about 17, and z is about 7.5), and XTJ-542 (in general formula (3), x is about 3, y is about 9, z is approximately 2).

  Further, as XYX type triblock polyether diamine (E), XYX-1 (general formula (3), x is about 3, y is about 14, z is about 2), XYX-2 (general formula (3) X is about 5, y is about 14, and z is about 4), and XYX-3 (in general formula (3), x is about 3, y is about 19, and z is about 2), etc. it can.

[Dicarboxylic acid compound (F)]
The dicarboxylic acid compound (F) used in the present invention is a compound represented by the following formula (4).
_{^{HOOC- (R 3) m -COOH (}} 4)

Here, R ³ represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 20 carbon atoms or an alkylene group having 1 to 20 carbon atoms. And more preferably the hydrocarbon group having 1 to 15 carbon atoms or the alkylene group having 1 to 15 carbon atoms, more preferably the hydrocarbon group having 2 to 12 carbon atoms or the alkylene group having 2 to 12 carbon atoms. Particularly preferably, it represents the above hydrocarbon group having 4 to 10 carbon atoms or an alkylene group having 4 to 10 carbon atoms. M represents 0 or 1.

  As the dicarboxylic acid compound (F), at least one dicarboxylic acid selected from aliphatic, alicyclic and aromatic dicarboxylic acids or derivatives thereof can be used.

  Specific examples of the dicarboxylic acid include linear aliphatic dicarboxylic acids having 2 to 25 carbon atoms such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid. Or aliphatic dicarboxylic acids such as dimerized aliphatic dicarboxylic acids having 14 to 48 carbon atoms (dimer acid) obtained by dimerizing unsaturated fatty acids obtained by fractional distillation of triglycerides and hydrogenated products thereof (hydrogenated dimer acid) Mention may be made of acids, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. As the dimer acid and hydrogenated dimer acid, trade names “Pripol 1004”, “Plipol 1006”, “Plipol 1009”, “Plipol 1013” and the like manufactured by Unikema Corporation can be used.

  The ratio of the polyamide-forming monomer to the total components of the polyether polyamide elastomer is preferably 10 to 95% by mass, more preferably 15 to 90% by mass, more preferably 15 to 85% by mass, and particularly preferably 15 to 80% by mass. %, Most preferably 15 to 70 mass. If the ratio of the polyamide-forming monomer to all the components of the polyether polyamide elastomer is 10% by mass or more, the crystallinity of the polyamide component can be improved, and mechanical properties such as strength and elastic modulus can be improved. Can do. If it is 95 mass% or less, the function and performance as elastomers, such as rubber elasticity and a softness | flexibility, can be expressed.

  Moreover, the ratio of the total amount of the (E) compound and the (F) compound with respect to all the components of the polyether polyamide elastomer is preferably 5 to 90% by mass, more preferably 10 to 85% by mass, and more preferably 15 to 85%. % By mass, particularly preferably 20 to 85% by mass, most preferably 30 to 85% by mass.

  The hardness (Shore D) of the polyether polyamide elastomer is preferably in the range of 30 to 65, more preferably in the range of 35 to 60. In the present invention, the hardness (Shore D) can be measured according to ASTM D2240.

  The flexural modulus of the polyether polyamide elastomer is preferably 20 to 450 MPa, more preferably 20 to 400 MPa, more preferably 20 to 350 MPa, and particularly preferably 20 to 300 MPa. When the elastic modulus is within the above range, an elastomer having particularly excellent toughness and rubber elasticity can be obtained. In the present invention, the flexural modulus can be measured according to ASTM D790.

  The tensile yield strength of the polyether polyamide elastomer is preferably in the range of 3-25 MPa, more preferably in the range of 3-22 MPa, more preferably in the range of 3-20 MPa, and particularly preferably in the range of 3-18 MPa. When the tensile yield point strength is in the above range, an elastomer having particularly excellent toughness and rubber elasticity can be obtained. In the present invention, the tensile yield point strength can be measured according to ASTM D-638.

  The tensile elongation at break of the polyether polyamide elastomer is preferably 300% or more, particularly preferably 600% or more. If the amount is less than this range, performance as an elastomer such as toughness and rubber elasticity becomes difficult to be exhibited, which may not be preferable. In the present invention, the tensile elongation at break can be measured according to ASTM D-638.

  The flexural strength of the polyether polyamide elastomer is preferably 0.8 to 15 MPa, more preferably 1 to 13 MPa, more preferably 1.1 to 10 MPa, and particularly preferably 1.2 to 9 MPa. When the bending strength of the polyether polyamide elastomer is within the above range, an elastomer having an excellent balance between toughness such as bending strength and rubber elasticity can be obtained. In the present invention, the bending strength can be measured according to ASTM D-790.

  It is preferable that the polyether polyamide elastomer is not broken (abbreviated as NB) in the measurement of impact strength with an Izod notch at 23 ° C., because it is particularly excellent in impact resistance. In the present invention, the impact strength with Izod notch can be measured in accordance with ASTM D-256.

  The deflection temperature under load of the polyether polyamide elastomer is preferably 50 ° C. or higher. Within the above range, the material is less likely to be deformed during use, which is preferable. In the present invention, the deflection temperature under load can be measured according to ASTM D-648.

  The relative viscosity (ηr) of the polyether polyamide elastomer is preferably in the range of 1.2 to 3.5 (0.5 mass / volume% metacresol solution, 25 ° C.).

[Method for producing polyether polyamide elastomer]
As an example of a method for producing a polyether polyamide elastomer, a polyamide-forming monomer (that is, an aminocarboxylic acid compound (D1) and / or a lactam compound (D2)), an XYX type triblock polyetherdiamine compound (E) and A method comprising a step of melt-polymerizing three components of dicarboxylic acid (F) under pressure and / or normal pressure, and further performing melt-polymerization under reduced pressure as required can be used. Further, a polyamide-forming monomer, XYX type Use a method comprising a step of simultaneously subjecting the three components of the triblock polyether diamine compound (E) and the dicarboxylic acid (F) to melt polymerization under pressure and / or normal pressure, and further performing melt polymerization under reduced pressure as necessary. Can do. A method of polymerizing the two components of the polyamide-forming monomer and the dicarboxylic acid (F) first and then polymerizing the XYX type triblock polyether diamine compound (E) can also be used.

  In the production of the polyether polyamide elastomer, there is no particular restriction on the raw material charging method, but the charging ratio of the polyamide-forming monomer, the XYX type triblock polyether diamine compound (E) and the dicarboxylic acid (F) is based on the total components. The polyamide-forming monomer is preferably 10 to 95% by mass, particularly preferably 15 to 90% by mass, and the XYX type triblock polyether diamine compound (E) is preferably 3 to 88% by mass, particularly preferably 8 to The range is 79% by mass. Among the raw materials, the XYX-type triblock polyether diamine compound (E) and the dicarboxylic acid (F) are approximately equimolar in the amino group of the XYX-type triblock polyether diamine compound (E) and the carboxy group of the dicarboxylic acid (F). It is preferable to prepare such that

  The polymerization temperature is preferably 150 to 300 ° C, more preferably 160 to 280 ° C, and particularly preferably 180 to 250 ° C. When the polymerization temperature is 150 ° C. or higher, the polymerization reaction proceeds favorably, and when it is 300 ° C. or lower, thermal decomposition is suppressed and a polymer having good physical properties can be obtained.

  The polyether polyamide elastomer can be produced by a method comprising a step of normal pressure melt polymerization or normal pressure melt polymerization followed by reduced pressure melt polymerization when ω-aminocarboxylic acid is used as the polyamide-forming monomer.

  On the other hand, when using a lactam or a diamine synthesized from a dicarboxylic acid and / or a salt thereof as a polyamide-forming monomer, an appropriate amount of water is allowed to coexist and melt polymerization under a pressure of 0.1 to 5 MPa is performed. And a subsequent method comprising normal pressure melt polymerization and / or reduced pressure melt polymerization.

  The polymerization time is usually 0.5 to 30 hours. If the polymerization time is 0.5 hours or more, the molecular weight can be increased, and if it is 30 hours or less, coloring due to thermal decomposition and the like can be suppressed, and a polyether polyamide elastomer having desired physical properties can be obtained. .

  The production of the polyether polyamide elastomer can be carried out batchwise or continuously, and a batch reactor, a single- or multi-tank continuous reactor, a tubular continuous reactor, etc. can be used alone or in combination. Can be used.

  When producing a polyether polyamide elastomer, monoamines and diamines such as laurylamine, stearylamine, hexamethylenediamine, and metaxylylenediamine, acetic acid, Monocarboxylic acids such as benzoic acid, stearic acid, adipic acid, sebacic acid and dodecanedioic acid, or dicarboxylic acids can be added. These used amounts are appropriately added so that the finally obtained polyether polyamide elastomer has a relative viscosity of 1.2 to 3.5 (0.5 mass / volume% metacresol solution, 25 ° C.). It is preferable.

  The addition amount of the above-mentioned monoamine and diamine, monocarboxylic acid and dicarboxylic acid is preferably set within a range that does not hinder the properties of the obtained polyether polyamide elastomer.

  When producing a polyether polyamide elastomer, phosphoric acid, pyrophosphoric acid, polyphosphoric acid, etc. are used as a catalyst as necessary, and phosphorous acid, hypophosphorous acid, for the effect of both the catalyst and the heat-resistant agent, Further, inorganic phosphorus compounds such as alkali metal salts and alkaline earth metal salts thereof can be added. The addition amount is usually 50 to 3000 ppm with respect to the charged raw materials.

  Other examples of the polyamide elastomer (B) include a polyamide elastomer of the formula (5).

In Formula (4), A is a polyamide sequence, B is a linear or branched aliphatic polyoxyalkylene glycol sequence, and the alkylene group has at least two carbon atoms, and n is an integer representing a repeating unit. . A process for producing a moldable and / or extrudable polyether ester amide block copolymer represented by the formula (4) comprises a dicarboxylic acid polyamide having a carboxylic acid group at a chain end and an average molecular weight of 300 to 15000. , Reacting in a molten state with a linear or branched aliphatic polyoxyalkylene glycol having a hydroxyl group at the chain end and an average molecular weight of 200 to 6000, and the reaction is carried out at a temperature of 100 to 400 ° C. under high vacuum, A catalyst containing a tetraalkylorthotitanate represented by the general formula Ti (OR) ₄ (wherein R is a linear or branched aliphatic hydrocarbon group having 1 to 24 carbon atoms) is added to the reaction mixture. In contrast, it can be obtained by carrying out in an amount of 0.01 to 5% by weight (Japanese Patent Publication No. 56-45419).

  Polyether polyamide elastomer is heat resistant agent, ultraviolet absorber, light stabilizer, antioxidant, antistatic agent, lubricant, slip agent, crystal nucleating agent, tackifier, and sealability improvement as long as its properties are not hindered. An agent, an antifogging agent, a release agent, a plasticizer, a pigment, a dye, a fragrance, a flame retardant, a reinforcing material, and the like can be added.

  Polyether polyamide elastomer has low water absorption, excellent melt moldability, excellent moldability, excellent toughness, excellent bending fatigue resistance, excellent rebound resilience, low specific gravity, and low temperature flexibility. Excellent low-temperature impact resistance, excellent stretch recovery, excellent sound deadening properties, excellent rubber properties and transparency.

  By a known molding method such as injection molding, extrusion molding, blow molding, and vacuum molding, a sheet-like molded article made of a polyether polyamide elastomer can be obtained.

  The polyether polyamide elastomer in the present invention is commercially available as “UBESTA XPA 9040X1, 9040F1, 9048X1, 9048F1, 9055X1, 9055F1, 9063X1, 9063F1, 9040X2, 9048X2, 9040F2, and 9048F2.” (Ube Industries, Ltd.) etc. can be used.

  The polyether polyamide elastomer has good compatibility with thermoplastic resins such as polyamide, polyvinyl chloride, thermoplastic polyurethane and ABS resin excluding the polyether polyamide elastomer used in the present invention, and should be blended with these thermoplastic resins. Thus, the moldability, impact resistance, elasticity and flexibility of these resins can be improved. The polyether polyamide elastomer has gas barrier properties, but the gas barrier properties can be further improved by mixing with other resins. Further, the polyether polyamide elastomer has an effect of accelerating vulcanization when added to rubber and vulcanized, and can contribute to improvement of productivity of rubber products.

[Inorganic reinforcing agent (C)]
Examples of the inorganic reinforcing agent (C) blended in the rubber composition according to the present invention include various carbon blacks, white carbon, silica, activated calcium carbonate, and ultrafine magnesium silicate. Among these, at least one of carbon black and silica is preferable. Particularly preferred is carbon black having a particle size of 90 nm or less and a dibutyl phthalate (DBP) oil absorption of 70 ml / 100 g or more. For example, FEF, FF, GPF, SAF, ISAF, SRF, and HAF are used.

  Silica preferably has a silica purity of 97% or more. Silica having a purity of less than 97% does not have a sufficient rubber reinforcing effect, so that a rubber composition blended with such silica does not have sufficient wear resistance. The average particle diameter of the silica particles is preferably in the range of 0.1 to 50 μ, more preferably 1 to 50 μ, and particularly preferably 5 to 50 μ. Such silica particles can be obtained, for example, by a method of pulverizing completely melted quartz glass to an appropriate particle size. Further, pulverized natural quartz having a silica purity of 97% or more is also preferably used. Furthermore, particles obtained by hydrolyzing an organosilicon compound such as silane are also preferably used.

  A coupling agent may be used so that the vulcanizable rubber (A) and silica are well mixed. As the coupling agent, an alkylphenol formaldehyde resin initial condensate, an acid anhydride, a silane coupling agent, and a titanate coupling agent are preferable, and a silane coupling agent is more preferable.

  Examples of silane coupling agents include alkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, diethoxydiethylsilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, dimethoxymethylphenylsilane, triethoxyethylsilane, and trimethoxyphenylsilane. , Trimethoxypropylsilane, phenyltriethoxysilane, hexyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, and N-dodecyltriethoxysilane.

  Including alkoxysilanes as described above, alkoxysilanes containing vinyl groups, alkoxysilanes having ester bonds, alkoxysilanes having epoxy groups, alkoxysilanes having amino groups, alkoxysilanes having mercapto groups, sulfide groups Examples include alkoxysilanes having chloro groups, alkoxysilanes having chloro groups, alkoxysilanes having styryl groups, alkoxysilanes having ureido groups, alkoxysilanes having isocyanate groups, and the like.

  Examples of alkoxysilanes having a vinyl group include vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinylsilane, vinylmethyldimethoxysilane, trichlorovinylsilane, allyltriethoxysilane, allyltrimethoxysilane, allyltrichlorosilane, and vinyltris. Alkoxysilanes having (2-methoxyethoxy) silaneacryloxy group or methacryloxy group, such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloxypropylmethyldiethoxysilane and 3-methacryloxypropylmethyldimethoxysilane.

  Examples of the alkoxysilanes having an ester bond include triacetoxymethylsilane and diacetoxydimethylsilane.

  Examples of alkoxysilanes having an epoxy group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyltriethoxysilane, and 3-glycol. Examples include cidoxypropyltrimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane.

  Examples of alkoxysilanes having an amino group include 3- (N-phenyl) aminopropyltrimethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyl Examples include methyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, and N- (vinylbenzyl) -2-aminoethyl-3-aminopropyl.

  Examples of alkoxysilanes having a mercapto group include 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

  Examples of alkoxysilanes having a sulfide group include 3-octanoylthio-1-propyltriethoxysilane and bis (triethoxysilylpropyl) tetrasulfide.

  Examples of alkoxysilanes having a chloro group include chloromethyltriethoxysilane, 3-chloropropyldimethoxymethylsilane, 3-chloropropyltrichlorosilane, 3-chloropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Chloropropyldimethoxymethylsilane, butyltrichlorosilane, chlorohexyltrichlorosilane, dodecaciltrichlorosilane, ethyltrichlorosilane, n-decyltrichlorosilane, n-octyltrichlorosilane, n-tetradecyltrichlorosilane, and phenyltrichlorosilane is there.

  Examples of alkoxysilanes having a styryl group include p-styryltrimethoxysilane.

  Examples of alkoxysilanes having a ureido group include 3-ureidopropyltriethoxysilane.

  Examples of alkoxysilanes having an isocyanate group include 3-isocyanatepropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, and tris- (3-trimethoxysilylpropyl) isocyanurate.

  A silane coupling agent may be used in combination of a plurality of the above compounds.

The amount of the silane coupling agent used is preferably 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight, particularly preferably 2 to 100 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A).
30 parts by weight.

In particular, an alkoxysilane having an amino group or an epoxy group is desirable.

  In addition, when a silane coupling agent having an amino group is used, it is effective for both a vulcanizable rubber such as SBR and a polyamide-based resin, and as a result, the compatibility between the two is activated. Since it increases, it is more preferable. Similarly, the same effect can be obtained with a silane coupling agent having an epoxy group.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of the carbon black / silica is preferably 90/10 to 5/95, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

  The amount of the inorganic reinforcing agent (C) used is 1 to 100 parts by weight, preferably 10 to 80 parts by weight, more preferably 20 to 70 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

[Other ingredients]
The rubber composition according to the present invention usually contains a vulcanizing agent, a vulcanization aid, an activator, an anti-scorch agent, an anti-aging agent, a filler, a process oil, zinc white, and stearic acid, if necessary. You may knead | mix the compounding agent used in the rubber industry.

  As the vulcanizing agent, known vulcanizing agents such as sulfur, organic peroxides, resin vulcanizing agents, and metal oxides such as magnesium oxide are used.

  As the vulcanization aid, known vulcanization aids such as aldehydes, ammonia, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, and xanthates are used.

  As the scorch inhibitor (retarder), organic acids, nitroso compounds, N-cyclohexylthiophthalimide, sulfonamide derivatives, and the like are used.

  Examples of the anti-aging agent include amine / ketone series, imidazole series, amine series, phenol series, sulfur series and phosphorus series.

  Examples of the filler include inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, Lissajous and diatomaceous earth, and organic fillers such as recycled rubber and powder rubber.

  The process oil may be any of aromatic, naphthenic, and paraffinic.

[Production of rubber composition]
The rubber composition according to the present invention is a condition in which the maximum temperature during kneading is equal to or higher than the melting point of the polyamide elastomer using a Banbury, an open roll, a kneader, a biaxial kneader or the like in which the above components are usually performed. It is obtained by kneading. The maximum temperature during kneading is preferably in the range of the same temperature as the melting point of the polyamide elastomer to a temperature higher by 50 ° C. than the melting point. More preferably, the temperature is 5 ° C higher than the melting point to 40 ° C higher than the melting point. If the maximum temperature during kneading is lower than the melting point of the polyamide elastomer, the polyamide elastomer does not melt and disperse, and if it is 50 ° C. higher than the melting point, the vulcanizable rubber may deteriorate.

[Use of rubber composition]
TECHNICAL FIELD The rubber composition according to the present invention relates to a rubber composition having high elasticity, high tensile strength, exothermic property, and excellent fatigue properties. Tire external members such as treads, sidewalls, chafers, etc. in tires, carcass belts・ Beads, inner liners and other tire internal components, anti-vibration rubber, rubber belts, hoses, seismic isolation rubber, fenders, and other industrial goods, men's shoes, women's shoes, and sports shoes, industrial and printing Rubber rolls for OA equipment, sports equipment such as golf balls, tennis balls and sports floors, solid tires for agriculture and forklifts, rubber crawlers, casters, sealing materials, adhesives, rubber sheets, waterproofing materials, packings, It can also be used for sponge products. The rubber composition is preferably used for a tire. Further, a rubber composition for a base tread, a rubber composition for a chafer, and a rubber composition for a sidewall, which will be described later, are preferable.

  Furthermore, when applied to an inner liner of a tire, a polyamide elastomer can be used as an adhesive layer between the carcass and the inner liner. Alternatively, in order to increase gas barrier properties, as an inner liner, polyamide elastomer resin or rubber, for example, halogenated butyl rubber, EVOH, low density polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetate, amorphous polyethylene terephthalate, which are known materials , Polyvinyl chloride, nylon 6, polyvinyl fluoride, polyvinylidene chloride, polyacrylonitrile, ethylene vinyl alcohol copolymer, polyvinyl alcohol, etc. can be used. In this case, the carcass and inner liner are directly laminated. You may do it.

Rubber composition for base tread:
Next, the base and the rubber composition for red according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the rubber composition for a base tread according to the present invention can be the same as those used in the above rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable.

  The vulcanizable rubber (A) used in the rubber composition for a base tread according to the present invention preferably contains SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent (C) used in the rubber composition for a base tread according to the present invention, the same one as that used in the above rubber composition can be used. However, the inorganic reinforcing agent (C) contains at least carbon black and silica, and the blending amount of silica in the inorganic reinforcing agent (C) is 80% by mass or less.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of carbon black / silica is preferably 95/5 to 20/80, more preferably 90/10 to 30/70, and particularly preferably 60/40 to 40/60. When the amount of silica is less than 5%, energy loss increases. When the amount is more than 80%, there is a drawback that workability and wear resistance are deteriorated.

  The amount of the inorganic reinforcing agent (C) used is 20 to 70 parts by weight, preferably 30 to 60 parts by weight, more preferably 35 to 55 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

[Wax (D)]
The rubber composition for a base tread according to the present invention preferably contains a wax in order to maintain ozone crack resistance of the tire groove bottom.

  The blending amount of the wax is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the vulcanizable rubber (A) from the viewpoint of good ozone crack resistance. 0.8 parts by weight or more is particularly preferable.

  Further, the blending amount of the wax is preferably 5 parts by weight or less (particularly 3 parts by weight or less with respect to 100 parts by weight of the vulcanizable rubber (A)) from the viewpoint of good wax blooming resistance.

  As the wax (D), it is particularly preferable to use a wax having a melting point of 60 ° C to 70 ° C.

  Specific examples of the wax (D) include Suntite S, R and E manufactured by Seiko Chemical Co., Ltd., and Sunnock N and P manufactured by Ouchi Shinsei Chemical Co., Ltd.

[Other ingredients]
In the rubber composition for a base tread according to the present invention, the same components as those used in the above rubber composition can be used as other components.

[Physical properties]
55-75 are preferable and, as for the JIS-A hardness of the rubber composition for base treads which concerns on this invention, 60-70 are especially preferable. When the hardness is less than 55, the steering stability tends to become unstable. When the hardness is 75 or more, the elongation at break tends to decrease.

  The tensile elongation of the rubber composition for base tread is preferably 350% to 600%, and more preferably 400% to 550%. If the tensile elongation of the rubber composition for a base tread is less than 350%, the target tire groove bottom cracks tend to grow, which is not preferable. On the contrary, when the tensile elongation is 600% or more, the exothermic property tends to deteriorate.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for base tread is preferably 0.1 or less. If it exceeds 0.1, fuel economy tends to be impaired. If tan δ is less than 0.03, fatigue may be deteriorated.

Chafer rubber composition:
Next, the chafer rubber composition according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the chafer rubber composition according to the present invention may be the same as those used in the above rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable. The vulcanizable rubber (A) preferably contains at least 30% by weight of natural rubber or polyisoprene rubber, and more preferably contains 40% by weight or more.

  The vulcanizable rubber (A) used in the chafer rubber composition according to the present invention preferably contains SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent (C) used in the chafer rubber composition according to the present invention, the same materials as those used in the above rubber composition can be used.

  The amount of the inorganic reinforcing agent (C) used is 60 to 100 parts by weight, preferably 60 to 90 parts by weight, more preferably 65 to 80 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

  When carbon black and silica used for the inorganic reinforcing agent are mixed, workability, low energy loss, wearability, and the like can both be achieved. Therefore, the inorganic reinforcing agent (C) is preferably a mixture of carbon black and silica. . In particular, the weight ratio of carbon black / silica is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

[Other ingredients]
As the other components used in the chafer rubber composition according to the present invention, the same components as those used in the above rubber composition can be used.

[Physical properties]
The JIS-A hardness of the chafer rubber composition according to the present invention is 70 or more, preferably 75 or more. If the JIS-A hardness of the rubber composition is less than 70, sufficient bead durability cannot be obtained. Further, the JIS-A hardness of the chafer rubber composition is 90 or less, preferably 85 or less. When the JIS-A hardness of the rubber composition exceeds 90, the elongation of the rubber composition is lowered.

  The vulcanization temperature of the chafer rubber composition is preferably 130 to 180 ° C. When the vulcanization temperature is less than 130 ° C., the vulcanization time becomes excessively long and the productivity is lowered. On the other hand, when the vulcanization temperature exceeds 180 ° C., it is difficult to make the elongation at break 180% or more, and when the tire is detached from the rim, the chafer tip of the bead portion is likely to be chipped.

  The breaking elongation of the chafer rubber composition is 180% or more, preferably 180% to 500%, and more preferably 250% to 400%. If the elongation at break of the chafer rubber composition is less than 180%, cracks at the tire groove bottom tend to grow, which is not preferable. Conversely, when the elongation at break exceeds 500%, the intended low heat build-up tends to be poor.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for chafer is preferably 0.2 or less. If it exceeds 0.2, fuel economy tends to be impaired. Note that if tan δ is less than 0.05, fatigue may be deteriorated.

Rubber composition for sidewalls:
Next, the rubber composition for a sidewall according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the rubber composition for a sidewall according to the present invention can be the same as those used in the rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable.

  The vulcanizable rubber (A) used in the sidewall rubber composition according to the present invention preferably includes SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent according to the present invention, the same materials as those used in the above rubber composition can be used.

  The amount of the inorganic reinforcing agent (C) used is 20 to 60 parts by weight, preferably 30 to 55 parts by weight, more preferably 40 to 50 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of carbon black / silica is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

[Wax (D)]
The rubber composition for a sidewall according to the present invention preferably contains a wax in order to maintain ozone crack resistance at the tire groove bottom.

  The blending amount of the wax is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the vulcanizable rubber (A) from the viewpoint of good ozone crack resistance. 0.8 parts by weight or more is particularly preferable.

  Further, the blending amount of the wax is preferably 5 parts by weight or less (particularly 3 parts by weight or less with respect to 100 parts by weight of the vulcanizable rubber (A)) from the viewpoint of good wax blooming resistance.

  As the wax (D), it is particularly preferable to use a wax having a melting point of 60 ° C to 70 ° C.

  Specific examples of the wax (D) include Suntite S, R and E manufactured by Seiko Chemical Co., Ltd., and Sunnock N and P manufactured by Ouchi Shinsei Chemical Co., Ltd.

[Other ingredients]
In the rubber composition for a sidewall according to the present invention, the same components as those used in the above rubber composition can be used as other components.

[Physical properties]
The rubber composition for sidewalls according to the present invention has a JIS-A hardness of 55 to 75, preferably 60 to 70. When the JIS-A hardness is less than 55, the steering stability tends to be unstable. When the JIS-A hardness exceeds 75, the elongation at break tends to decrease.

  The breaking elongation of the rubber composition for a sidewall is preferably 300% to 700%, and more preferably 400% to 600%. If the breaking elongation of the rubber composition for sidewalls is less than 300%, cracks at the tire groove bottom tend to grow, which is not preferable. Conversely, when the elongation at break exceeds 700%, the intended low heat build-up tends to be poor.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for sidewall is preferably 0.15 or less. If it exceeds 0.15, fuel economy tends to be impaired. If tan δ is less than 0.03, fatigue may be deteriorated.

〔tire〕
The tire according to the present invention has the rubber composition for a base tread obtained in the present invention, so that the rolling resistance can be reduced without lowering the steering stability.

  Since the tire according to the present invention has the chafer rubber composition obtained in the invention, a tire excellent in exothermic property, elongation at break, hardness and fatigue and excellent in balance between them can be obtained.

  The tire according to the present invention can improve heat generation, chip cut resistance, hardness, and flex crack growth by having the rubber composition for a sidewall obtained in the invention.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In Examples and Comparative Examples, the physical properties of vulcanizable rubber and the properties of the resulting rubber composition and the vulcanized product were measured as follows.

[Rubber properties that can be vulcanized]
(1) Mooney viscosity (ML)
The Mooney viscosity (ML) was measured by a Mooney viscometer (SMV-202, manufactured by Shimadzu Corp.) in accordance with JIS-K6300 and preheated for 1 minute at 100 ° C. for 4 minutes.

(2) Intrinsic viscosity [η]
Intrinsic viscosity [η] is obtained by adding 0.1 g of sample rubber and 100 ml of toluene into an Erlenmeyer flask and completely dissolving them at 30 ° C., and then in a constant temperature water bath maintained at 30 ° C. 10 ml was added, the falling time (T) of the solution was measured, and the value obtained by the following formula was used.
ηsp = T / T0-1 (T0: falling time of toluene only)
ηsp / c = [η] + k ′ [η] 2c
(Ηsp: specific viscosity, k ′: Huggins constant (0.37), c: sample concentration (g / ml))

(3) Toluene solution viscosity (Tcp)
Toluene solution viscosity (Tcp) was obtained by dissolving 2.28 g of polymer in 50 ml of toluene, and using viscometer calibration standard solution (JIS-Z8809) as a standard solution. 400 was used and measured at 25 ° C.

(4) Microstructure The microstructure was analyzed by infrared absorption spectrum analysis. The microstructure was calculated from the absorption intensity ratio of cis 740 cm ⁻¹ , trans 967 cm ⁻¹ and vinyl 910 cm ⁻¹ .

(5) ηsp / c
ηsp / c was a reduced viscosity measured at 135 ° C. from a 0.20 g / dl o-dichlorobenzene solution as a measure of the molecular weight of 1.2 polybutadiene crystal fiber.

[Rubber properties after compounding]
The Mooney viscosity (ML1 + 4, 100 ° C.) was measured by a Mooney viscometer (SMV-202, manufactured by Shimadzu Corporation) in accordance with JIS-K6300, with a preheat 1 minute measurement at 100 ° C. for 4 minutes. The smaller the value, the lower the viscosity and the better the fluidity.

Die swell is a measure of the dimensional stability of the compound, using a processability measuring device (manufactured by Monsanto, MPT) at a shear rate of 100 ° C. and 100 sec ⁻¹ and the cross-sectional area of the compound during extrusion. The ratio of the die orifice cross-sectional area (where L / D = 1.5 mm / 1.5 mm) was measured. It shows that extrusion property is so favorable that a numerical value is small.

  Vulcanization characteristics (t90) were measured using a curator meter IIF manufactured by JSR Corporation at a temperature of 150 ° C. until the vulcanization torque reached 90%. The smaller the value, the shorter the vulcanization time. .

[Vulcanized physical properties]
The JIS-A hardness indicates that the hardness is higher as the numerical value is larger, measured with a type A durometer in accordance with the measurement method defined in JIS-K6253.

  Tensile stress measured 100% tensile stress according to JIS-K6251. The larger the value, the higher the tensile stress.

  As for the tensile strength, the tensile strength at break was measured according to JIS-K6251. It shows that tensile strength is so high that a numerical value is large.

  The elongation at break was measured by measuring the elongation at break according to JIS-K6251. It shows that breaking elongation is so large that a numerical value is large.

  The tear strength was measured according to JIS-K6252. It shows that tear strength is so high that a numerical value is large.

  Tensile fatigue resistance is measured by using a tensile fatigue tester (manufactured by Yasuda Seiki Seisakusho) to make a 0.5 mmφ scratch in the center of a dumbbell-shaped No. 3 (JIS-K6251) test piece, with an initial strain of 100%, 300 times / The number of times the test piece broke was measured under the condition of minutes. The larger the value, the better the stretch fatigue property.

  The exothermic property was measured according to the measurement method defined in JIS-K6265. The smaller the numerical value, the smaller the calorific value and the better.

  The loss factor (tan δ) was measured using RPA2000 (manufactured by Alpha Technologies) under the conditions of 60 ° C., 10 Hz, and 2% strain. The smaller the value, the smaller the energy loss and the better.

  The bending crack growth property was measured in accordance with JIS-K6260, and the crack length was measured when the movement distance of the specimen gripper was bent 10,000 times at 30 mm using a dimer bending tester (manufactured by Ueshima Seisakusho). It shows that bending crack growth resistance is so favorable that a numerical value is small.

  Abrasion was measured under the condition of a slip rate of 20% using a Lambourn abrasion tester specified in JIS-K6265. The smaller the numerical value, the smaller the amount of wear and the better.

  The oxygen permeability was measured under the conditions of 23 ° C. and 50% relative humidity using an oxygen gas permeation measuring device (MOCON-OX-TRAN 2/20 manufactured by Modern Control) according to ASTM-D3985. The smaller the value, the less oxygen permeation and the better the gas barrier property.

Hereinafter, the characteristic value of the polyether polyamide elastomer was measured as follows.
(1) Relative viscosity (ηr) (0.5 mass / volume% metacresol solution, 25 ° C.)
Using reagent-grade m-cresol as a solvent, it was measured at 25 ° C. using an Ostwald viscometer at a concentration of 5 g / dm ³ .

(2) Terminal carboxy group concentration ([COOH])
40 ml of benzyl alcohol was added to about 1 g of the polymer, heated and dissolved in a nitrogen gas atmosphere, phenolphthalein was added as an indicator to the obtained sample solution, and titrated with an N / 20 potassium hydroxide-ethanol solution.

(3) Terminal amino group concentration ([NH ₂ ])
About 1 g of the polymer was dissolved in 40 ml of a phenol / methanol mixed solvent (volume ratio: 9/1), thymol blue was added as an indicator to the obtained sample solution, and titrated with N / 20 hydrochloric acid.

(4) Melting point (Tm) and crystallization temperature (Tc)
Tm and Tc were measured under a nitrogen atmosphere using a differential scanning calorimeter DSC-50 manufactured by Shimadzu Corporation. The temperature was raised from room temperature to 230 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 230 ° C. for 10 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first run). Then, the temperature was raised to 230 ° C. at a rate of 10 ° C./min (referred to as a temperature raised second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(5) Composition The composition of the polyether polyamide elastomer was determined from a proton NMR spectrum measured at room temperature using JNM-EX400WB type FT-NMR manufactured by JEOL Ltd. at a concentration of 4% by mass using heavy trifluoroacetic acid as a solvent. The composition of each component was determined.

(6) Shore D hardness Shore D was measured according to ASTM D2240. It measured using the sheet | seat of thickness 6mm shape | molded by injection molding. The measurement was performed at a temperature of 23 ° C.

(7) Mechanical properties: Measurements (i) to (iv) shown below were performed by molding the following test pieces by injection molding.
(I) Tensile test (tensile yield point strength and tensile elongation at break): A Type I test piece described in ASTM D638 was measured according to ASTM D638.
(Ii) Bending test (flexural modulus and bending strength): Measured according to ASTM D790 using a test piece having a test piece size of 6.35 mm × 12.7 mm × 127 mm.
(Iii) Impact strength (with Izod notch): Measured at 23 ° C. in accordance with ASTM D256 using a test piece with dimensions of 12.7 mm × 12.7 mm × 63.5 mm.
(Iv) Deflection temperature under load: It was measured at a load of 0.45 MPa in accordance with ASTM D648 using a test piece having a test piece size of 6.35 mm × 12.7 mm × 127 mm.

Production Example 1 (Production of PAE1)
In a 70 liter pressure vessel equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator and polymer outlet, Ube Industries' 12-aminododecanoic acid 8.000 kg, ABA type Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) and 10.429 kg of adipic acid were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 8 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 12 kg of pellets. The obtained pellets are white tough and flexible polymers rich in rubber elasticity, ηr = 2.16, [COOH] = 1.28 × 10 −5 eq / g, [NH 2] = 1.86 × 10 −5 eq / g, Mn = 63700, Tm = 135 ° C., Tc = 59 ° C. The polymer composition is PA12 / XTJ-542 / AA = 40.7 / 52.9 / 6.4 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 units XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 40, flexural modulus: 76 MPa, bending strength: 4.3 MPa, tensile yield strength: 6.3 MPa, tensile breaking elongation: 300% or more, impact strength: NB, load deflection temperature: 48 ° C.

Production Example 2 (Production of PAE2)
Ube Industries Co., Ltd. 12-aminododecanoic acid 11.200kg, ABA type in a 70 liter pressure vessel equipped with stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator and polymer outlet Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) and 7.121 kg of adipic acid were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 6 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 12 kg of pellets. The obtained pellets are white tough and flexible polymers rich in rubber elasticity, ηr = 2.22, [COOH] = 1.61 × 10 −5 eq / g, [NH 2] = 2.17 × 10 −5 eq / g, Mn = 52900, Tm = 154 ° C., Tc = 109 ° C. Polymer composition is PA12 / XTJ-542 / AA = 56.5 / 38.9 / 4.6 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 unit XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 48, flexural modulus: 132 MPa, bending strength: 7.2 MPa, tensile yield strength: 9.2 MPa, tensile breaking elongation: 300% or more, impact strength: NB, deflection temperature under load: 73 ° C.

Production Example 3 (Production of PAE3)
A 70-liter pressure vessel equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator, and polymer outlet, Ube Industries, Ltd. 12-aminododecanoic acid 14.000 kg, ABA type Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) 5.236 kg and adipic acid 0.764 kg were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 6.5 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 13 kg of pellets. The obtained pellets are white tough and flexible polymer rich in rubber elasticity, ηr = 2.05, [COOH] = 2.48 × 10 −5 eq / g, [NH 2] = 2.82 × 10 −5 eq / g, Mn = 37700, Tm = 163 ° C., Tc = 123 ° C. The polymer composition is PA12 / XTJ-542 / AA = 70.1 / 26.6 / 3.3 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 units XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 55, flexural modulus: 232 MPa, bending strength: 11.9 MPa, tensile yield strength: 14.8 MPa, tensile breaking elongation: 300% or more, impact strength: NB, deflection temperature under load: 78 ° C.

Production Example 4 (Production of nano VCR)
(A) Preparation of vinyl cis-polybutadiene Content of nitrogen gas substituted in a 1.5 L stainless steel reactor equipped with a stirrer 1.0 L of polymerization solution (butadiene; 31.5 wt%, 2-butenes: 28.8 wt%) , Cyclohexane; 39.7 wt%), and added water 1.7 mmol, diethylaluminum chloride 2.9 mmol, carbon disulfide 0.3 mmol, cyclooctadiene 13.0 mmol, and cobalt octoate 0.005 mmol, and at 60 ° C. The mixture was stirred for 20 minutes to perform 1,4 cis polymerization. Thereafter, 150 ml of butadiene, 1.1 mmol of water, 3.5 mmol of triethylalumonium chloride, and 0.04 mmol of cobalt octoate were added, and the mixture was stirred at 40 ° C. for 20 minutes to perform 1,2 syndiopolymerization. To this was added an anti-aging ethanol solution. Thereafter, unreacted butadiene and 2-butenes were removed by evaporation to obtain a vinyl cis polybutadiene having a yield of 66 g and HI; 40.5%. Of this, 58 g of vinyl cis polybutadiene was dissolved in cyclohexane to prepare a vinyl cis polybutadiene slurry.

(B) Preparation of cis-polybutadiene In a 1.5 L stainless steel reactor equipped with a stirrer, the content was replaced with nitrogen gas, 1.0 L of a polymerization solution (butadiene; 31.5 wt%, 2-butenes; 28.8 wt%, Cyclohexane; 39.7 wt%), 1.7 mmol of water, 2.9 mmol of diethylaluminum chloride, 20.0 mmol of cyclooctadiene, and 0.005 mmol of cobalt octoate are added, and the mixture is stirred at 60 ° C. for 20 minutes. Cis polymerization was performed. The polymerization was stopped by adding an anti-aging agent ethanol solution thereto. Thereafter, unreacted butadiene and 2-butenes were removed by evaporation to obtain 81 g of cis-polybutadiene having a Mooney viscosity of 29.0 and a toluene solution viscosity of 48.3. This operation was carried out twice and a total of 162 g of cis-polybutadiene was dissolved in cyclohexane to prepare a cis-polybutadiene cyclohexane solution.

(A) + (B) Prototype of VCR Manufacture of VCR Contents Replaced with nitrogen gas 5.0L A stainless steel reaction vessel with a stirrer is charged with cis-polybutadiene cyclohexane solution in which 162 g of cis polybutadiene described above is dissolved. A vinyl cis polybutadiene cyclohexane slurry containing 58 g of vinyl cis polybutadiene described above was added with stirring. After adding the slurry, the mixture was stirred for 1 hour and then vacuum-dried at 105 ° C. for 60 minutes to obtain 220 g of nano VCR which is a mixture of (A) + (B).

  The ML of this nano-VCR was 62, and the content of 1.2 polybutadiene crystal fiber was 11.9%. The melting point of 1.2 polybutadiene crystal fiber was 203 ° C., ηsp / c was 1.7, the average fiber length was 156 nm, the aspect ratio was 2.8, and the number of crystal fibers was 123.

  ηsp / c was a reduced viscosity measured at 135 ° C. from a 0.20 g / dl o-dichlorobenzene solution as a measure of the molecular weight of 1.2 polybutadiene crystal fiber.

  1.2 The melting point and content of the polybutadiene crystal fiber were obtained by using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) to obtain an endothermic curve at a heating rate of 10 ° C./min. The content was calculated from the endothermic amount.

The average fiber length of crystal fibers, the number of crystal fibers having a fiber length of 200 nm or less, and the average aspect ratio of crystal fibers were determined as follows. The vinyl cis-polybutadiene rubber was vulcanized in a mixed solution of sulfur monochloride and carbon disulfide, and an ultrathin section was cut out from the vulcanized product with an ultramicrotome (manufactured by Leica). The section was observed with a transmission electron microscope (H-7100FA type, manufactured by Hitachi, Ltd.), and a 5000-times photograph was taken. The photograph was binarized in an area of 25 μm ² using image analysis software (Win ROOF (manufactured by Mitani Corporation)), and the fiber length, aspect ratio, and area of the crystal fiber were obtained. Next, the average fiber length and aspect ratio were averaged by multiplying the value of each crystal fiber by the area fraction to obtain the average fiber length of crystal fibers and the average aspect ratio of crystal fibers. The number of crystal fibers was determined by calculating the number of fibers having a fiber length of 200 nm or less per 1.2 mass% of polybutadiene crystal fiber content.

(Rubber composition)
Examples 1-5 and Comparative Examples 1-2
Next, Examples 1-5 and Comparative Examples 1-2 will be described. Among the formulation shown in Table 1, vulcanization accelerator, BR150 excluding sulfur (ML = 43, Tcp = 75), PAE and compounding agent using a 1.7 liter Banbury mixer for test, start temperature 90 ° C. For 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are collectively shown in Table 1 as an index with Comparative Example 1 as 100. The symbols shown in the table are common to all the following tables and indicate the following.

(* 1) High-cis polybutadiene rubber manufactured by Ube Industries, Ltd. (* 2) UBESTA XPA9040X1 (melting point 135 ° C., hardness 40) manufactured by Ube Industries, Ltd.
(* 3) UBESTA XPA9048X1 (melting point 154 ° C, hardness 48) manufactured by Ube Industries, Ltd.
(* 4) UBESTA XPA9055X1 (melting point 163 ° C., hardness 55) manufactured by Ube Industries, Ltd.
(* 5) UBESTA XPA9068X1 (melting point 181 ° C, hardness 68) manufactured by Ube Industries, Ltd.
(* 6) Dia Black H manufactured by Mitsubishi Chemical Corporation
(* 7) High-cis polybutadiene rubber manufactured by Ube Industries, Ltd. (* 8) NipsilAQ manufactured by Tosoh Silica
(* 9) Degussa silane coupling agent (* 10) Ube Industries, Ltd. Reinforced polybutadiene rubber (* 11) Nano VCR manufactured in Production Example 4
(* 12) PEBAX 5533 manufactured by ARKMA (melting point 159 ° C, hardness 55)
(* 13) Suntite S manufactured by Seiko Chemical Co., Ltd.

  From Table 1, the rubber compositions of Examples 1 to 5 are superior to Comparative Example 1 in vulcanization characteristics and processability (small die swell), high elasticity, large tensile strength, exothermic property and elongation fatigue property, It turns out that it is excellent in gas barrier property. Further, since the PAE used in Comparative Example 2 had a high melting point, it was not melted and dispersed during kneading and remained in a pellet form.

Examples 6 to 10 and Comparative Examples 3 to 5
Next, Examples 6 to 10 and Comparative Examples 3 to 5 will be described. Among the compounding recipes shown in Table 2, vulcanization accelerator, BR150L excluding sulfur (ML = 43, Tcp = 105), NR, PAE and compounding agent using a 1.7 liter Banbury mixer for test, start temperature The mixture was kneaded at 90 ° C. for 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the resulting vulcanizate were measured, and the results are collectively shown in Table 2 as an index with Comparative Example 3 being 100.

  It can be seen from Table 2 that the physical properties of the examples blended with the polyamide elastomer are improved in a balanced manner as compared with the comparative examples.

Examples 11-16 and Comparative Examples 6-8
Next, Examples 11 to 16 and Comparative Examples 6 to 8 will be described. Of the formulation shown in Table 3, vulcanization accelerator, BR150L excluding sulfur (ML = 43, Tcp = 105), NR, PAE and compounding agent using a 1.7 liter Banbury mixer for test, start temperature The mixture was kneaded at 90 ° C. for 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the resulting vulcanizate were measured, and the results are collectively shown in Table 3 as an index with Comparative Example 6 being 100.

  From Table 3, it can be seen that when a proper amount of polyamide elastomer is blended, each physical property is improved in a well-balanced manner. In Comparative Examples 6 and 7 with a small amount of polyamide elastomer, the effect was not recognized, and Comparative Example 8 with a large amount was discharged from the Banbury mixer in a discrete state, and secondary mixing with a roll was not possible.

Examples 17 to 21 and Comparative Example 9
Next, Examples 17 to 21 and Comparative Example 9 will be described. Among the compounding formulations shown in Table 4, VCR or BR150L (ML = 43, Tcp = 105) excluding sulfur, NR, PAE and compounding agent using a 1.7 liter Banbury mixer for testing. The mixture was kneaded for 5 minutes at a start temperature of 90 ° C. to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are collectively shown in Table 4 as an index with Comparative Example 9 taken as 100.

  From Table 4, it can be seen that the physical properties are further improved in a balanced manner by combining the polyamide elastomer with the VCR or nano VCR.

[Rubber composition for base tread]
Examples 22-25 and Comparative Examples 10-11
Next, Examples 22 to 25 and Comparative Examples 10 to 11 will be described. Among the formulation shown in Table 5, vulcanization accelerator, BR150L excluding sulfur (ML = 43, Tcp = 105), NR, PAE and compounding agent using 1.7 liter test Banbury mixer, start temperature The mixture was kneaded at 90 ° C. for 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are collectively shown in Table 5 as an index with Comparative Example 10 taken as 100.

  From Table 5, the rubber compositions of Examples 22 to 25 have excellent processability (small die swell), high elasticity, high tensile strength, high elongation at break, and excellent flex crack growth compared to Comparative Example 10. I understand that. Moreover, since PAE used in Comparative Example 10 had a high melting point, it did not melt and disperse during kneading and remained in a pellet form.

Examples 26-30 and Comparative Examples 12-14
Next, Examples 26 to 30 and Comparative Examples 12 to 14 will be described. Among the formulation shown in Table 6, VCR or Nano VCR excluding sulfur, NR, PAE and compounding agent are kneaded for 5 minutes at a start temperature of 90 ° C. using a 1.7 liter Banbury mixer for testing. Thus, a primary kneaded product was obtained. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the resulting vulcanizate were measured, and the results are collectively shown in Table 6 as an index with Comparative Example 12 being 100.

  From Table 6, it can be seen that when polyamide elastomer is blended with VCR or nano-VCR, each physical property is improved in a well-balanced manner. Further, Comparative Example 13 with a small amount of inorganic reinforcing agent (carbon black and silica) is not sufficient in hardness and tensile strength, and Comparative Example 14 with a large amount is inferior in heat generation and flex crack growth. I understand.

[Rubber composition for chafer]
Examples 31-34 and Comparative Examples 15-16
Next, Examples 31 to 34 and Comparative Examples 15 to 16 will be described. Of the formulation shown in Table 7, the vulcanization accelerator, VCR, NR and PAE excluding sulfur, and the formulation were kneaded for 5 minutes at a start temperature of 90 ° C using a 1.7 liter Banbury mixer for testing. A kneaded product was obtained. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are summarized in Table 7.

  From Table 7, it can be seen that the rubber compositions of Examples 31 to 34 have excellent processability (small die swell), high hardness, high elongation at break, and excellent flex crack growth compared to Comparative Example 15. . Further, since the PAE used in Comparative Example 16 had a high melting point, it did not melt and disperse during kneading and remained in a pellet form.

Examples 35-38 and Comparative Examples 17-19
Next, Examples 35 to 38 and Comparative Examples 17 to 19 will be described. Among the compounding formulations shown in Table 8, VCR or BR150L (ML = 43, Tcp = 105) excluding sulfur, NR, PAE and compounding agent using a 1.7 liter Banbury mixer for testing. The mixture was kneaded for 5 minutes at a start temperature of 90 ° C. to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the resulting vulcanizate were measured, and the results are summarized in Table 8.

  From Table 8, it can be seen that when a polyamide elastomer is blended, each physical property is improved in a well-balanced manner. Further, Comparative Example 18 with a small amount of the inorganic reinforcing agent was not sufficiently hard, and Comparative Example 19 with a large amount was discharged from the Banbury mixer in a discrete state and could not be secondarily mixed with a roll. .

[Rubber composition for sidewall]
Examples 39 to 42 and Comparative Examples 20 to 21
Next, Examples 39 to 42 and Comparative Examples 20 to 21 will be described. Among the formulation shown in Table 9, vulcanization accelerator, BR150 excluding sulfur (ML = 43, Tcp = 75), NR, PAE and compounding agent using 1.7 liter test Banbury mixer, start temperature The mixture was kneaded at 90 ° C. for 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are summarized in Table 9.

  From Table 9, the rubber compositions of Examples 39 to 42 have superior processability (small die swell), high elasticity, high tensile strength, high elongation at break, and excellent flex crack growth properties compared to Comparative Example 20. I understand. Moreover, since PAE used in Comparative Example 21 had a high melting point, it did not melt and disperse during kneading and remained in a pellet form.

Examples 43 to 48 and Comparative Examples 22 to 24
Next, Examples 43 to 48 and Comparative Examples 22 to 24 will be described. Among the compounding formulations shown in Table 10, VCR or BR150L (ML = 43, Tcp = 105) excluding sulfur, NR, PAE and compounding agent using a 1.7 liter Banbury mixer for testing. The mixture was kneaded for 5 minutes at a start temperature of 90 ° C. to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are summarized in Table 10.

  From Table 10, it can be seen that the physical properties are further improved in a well-balanced manner by combining the polyamide elastomer with the VCR or nano-VCR. Further, Comparative Example 23 with a small amount of the inorganic reinforcing agent is not sufficient in hardness, tensile strength, and elongation at break, and Comparative Example 24 with a large amount is inferior in heat generation and flex crack growth. .

  The present invention relates to a rubber composition comprising a vulcanizable rubber, a polyamide elastomer having a melting point of 100 to 180 ° C. and an inorganic reinforcing agent, a rubber composition for a base tread, a rubber composition for a chafer, and a rubber composition for a sidewall. About.

  In recent years, attention has been paid to technologies for reducing fuel consumption of automobiles, in particular, reducing fuel consumption of tires, in consideration of the environment that is demanded worldwide. Generally, the fuel consumption of a tire is reduced by reducing the amount of reinforcing agent that restrains the polymer and reducing the hysteresis of rubber. However, reducing the amount of the reinforcing agent not only reduces the reinforcing property of the tire, but also causes a problem that the hardness decreases.

  Therefore, there is a method of reducing the hysteresis of the rubber by increasing the amount of the crosslinking agent, but there is a problem that the rubber itself becomes brittle and the crack growth property is promoted, and further improvement is required.

  Further, in order to solve the above-described problems, it is necessary to improve the reinforcement of the rubber itself without reducing the reinforcement even if the amount of the reinforcing agent is reduced. As a measure therefor, Patent Document 1 describes that a reinforcing effect is maintained even if the reinforcing agent is reduced by using a butadiene rubber that is changed to syndiotactic polybutadiene having a high reinforcing property. However, with the method using syndiotactic polybutadiene, it has been difficult to improve the target fuel efficiency, elongation at break, balance of hardness, etc. comprehensively.

Patent Document 2 discloses a rubber composition in which a thermoplastic polyamide refined (or shortened fiber) and silica particles are blended with rubber to improve the wear resistance of a roll of OA equipment. Further, Patent Document 3 discloses a rubber composition for a seismic isolation laminate that absorbs vibration energy efficiently with a high elastic modulus by blending natural rubber or the like with a polyamide elastomer and fine carbon black.
JP 2006-124503 A JP 7-224189 A Japanese Patent Laid-Open No. 10-237221

  However, generally, when a resin or fiber is blended with rubber, there is a problem in that although it becomes highly elastic, the tensile strength is lowered, and heat generation and fatigue are deteriorated. In addition, although any desired effect can be obtained with any of the techniques, there is a problem that the tensile strength and the like are reduced, and when it is used for a tire member, particularly a base tread, a more practical one is required. Yes.

  Furthermore, the durability of the bead portion that comes into contact with the belt portion or the rim of a heavy load tire such as a truck or bus is particularly insufficient among the tires, and particularly the bead portion needs to have sufficient durability. Further, a chafer is blended as a hard rubber part between the rim and the bead part for the purpose of suppressing deformation of the bead part, but it is not sufficient in terms of hardness, elongation at break and the like.

  Further, among the tires, particularly, the side wall rubber of heavy-duty tires such as trucks and buses, problems such as bending crack growth and hardness remain, and more practical ones have been demanded.

  Accordingly, a first object of the present invention is to provide a rubber composition having high elasticity, high tensile strength, and excellent heat generation and fatigue.

  The present invention also provides a rubber composition for a base tread, a base tread, and a tire including the same, having high elasticity, high tensile strength, high elongation at break, excellent heat generation and fatigue, and excellent balance between them. The second purpose is to do.

  Furthermore, a third object of the present invention is to provide a chafer rubber composition, chafer, and a tire including the same, which are excellent in exothermic property, elongation at break, hardness, and fatigue properties and are well balanced. And

  Furthermore, the present invention provides a rubber composition for a sidewall, a sidewall, and a tire including the same, which are excellent in exothermic property, chip cut resistance, hardness, fatigue property, and flex crack growth property, and in an excellent balance thereof. The fourth purpose is to provide it.

  In order to achieve the first object described above, the present inventors have conducted extensive research, and as a result, polyamide elastomer (B) having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). ) By containing 0.1 to 50 parts by weight and 1 to 100 parts by weight of the inorganic reinforcing agent (C), it is possible to obtain a rubber composition having high elasticity, high tensile strength, and excellent exothermic and fatigue properties. I found out that I can do it.

  That is, the present invention is based on 100 parts by weight of vulcanizable rubber (A), 0.1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 1 to 100 parts by weight of an inorganic reinforcing agent (C). A rubber composition characterized by containing a part.

  Moreover, in order to achieve the above second object, the present inventors have made extensive studies, and as a result, polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1-50 parts by weight and inorganic reinforcing agent (C) 20-70 parts by mass, the inorganic reinforcing agent (C) contains at least carbon black and silica, and the silica in the inorganic reinforcing agent (C) When the blending amount is 80% by mass or less, it is possible to obtain a rubber composition for a base tread having high elasticity, large tensile strength and elongation at break, excellent exothermic property and fatigue property, and excellent balance between them. I found.

  That is, the present invention comprises 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 70 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of vulcanizable rubber (A). A rubber composition for a base tread, wherein the inorganic reinforcing agent (C) contains at least carbon black and silica, and the amount of silica in the inorganic reinforcing agent (C) is 80% by mass or less. . Moreover, this invention is a base tread containing the said rubber composition for base treads. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire, which have the said base tread.

  Furthermore, in order to achieve the above third object, the present inventors have conducted extensive research and have found that a polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1 to 50 parts by weight and inorganic reinforcing agent (C) 60 to 100 parts by weight, JIS-A hardness is 70 to 90, and elongation at break in a tensile test is 180% or more. It has been found that a rubber composition for chafers can be obtained which is excellent in elongation at break, hardness and fatigue properties and in an excellent balance between them.

  That is, the present invention comprises 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 60 to 100 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of vulcanizable rubber (A). It is a rubber composition for chafers containing JIS-A hardness of 70 to 90 and elongation at break in a tensile test of 180% or more. Moreover, this invention is a chafer containing the said rubber composition for chafers. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire which have the said chafer.

  Furthermore, in order to achieve the fourth object described above, the present inventors have made extensive studies, and as a result, polyamide elastomer having a melting point of 100 to 180 ° C. with respect to 100 parts by weight of vulcanizable rubber (A). (B) 1-50 parts by weight and inorganic reinforcing agent (C) 20-60 parts by weight, JIS-A hardness 55-75, exothermic, chip-cut resistance, hardness, fatigue and It has been found that a rubber composition for a sidewall can be obtained that has excellent flex crack growth and is well balanced.

  That is, the present invention contains 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 60 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of the vulcanizable rubber (A). And a rubber composition for a sidewall, having a JIS-A hardness of 55 to 75. Moreover, this invention is a side wall containing the said rubber composition for side walls. Furthermore, this invention is tires, such as a tire for passenger cars and a studless tire which have the said sidewall.

  As described above, according to the present invention, it is possible to provide a rubber composition having high elasticity, high tensile strength, and excellent heat generation and fatigue properties.

  The present invention also provides a rubber composition for a base tread, a base tread, and a tire including the same, having high elasticity, high tensile strength, high elongation at break, excellent heat generation and fatigue, and excellent balance between them. can do.

  Furthermore, the present invention can provide a rubber composition for chafers, a chafer, and a tire including the same, which are excellent in exothermic property, elongation at break, hardness, and fatigue properties and are well balanced.

  Furthermore, the present invention provides a rubber composition for a sidewall, a sidewall, and a tire including the same, which are excellent in exothermic property, chip cut resistance, hardness, fatigue property, and flex crack growth property, and in an excellent balance thereof. Can be provided.

Rubber composition:
Next, the rubber composition according to the present invention will be described.

[Vulcanizable rubber (A)]
The vulcanizable rubber used in the rubber composition according to the present invention is not particularly limited, and any known rubber can be used, and a diene rubber can be preferably used. For example, diene monomers such as natural rubber, butadiene rubber (BR), syndiotactic-1,2-polybutadiene (SPB) -containing butadiene rubber, SPB-containing natural rubber, isoprene rubber, butyl rubber, and chloroprene rubber. Polymer; Acrylonitrile-diene copolymer rubber such as acrylonitrile butadiene rubber (NBR), nitrile chloroprene rubber, and nitrile isoprene rubber; Styrene-diene copolymer rubber such as styrene butadiene rubber (SBR), styrene chloroprene rubber, and styrene isoprene rubber And ethylene propylene diene rubber (EPDM) and the like. Among these, butadiene rubber, syndiotactic-1,2-polybutadiene-containing butadiene rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, natural rubber, and isoprene rubber are preferable. These can be used alone or in combination of two or more.

  Syndiotactic-1,2-polybutadiene-containing butadiene rubber includes 1,3-butadiene syndiotactic-1,2 polymerized (SPB) and 1,3-butadiene cis-1,4 polymerized. It can be obtained by mixing (for example, Japanese Patent Publication No. 3-63566).

Particularly preferred among SPB-containing butadiene rubbers is a specific syndiotactic compound in which the average length of crystal fibers is 90 nm or more per 25 μm ² and the melting point is 170 ° C. or more. 1,2-polybutadiene crystal fiber 1-30 wt%, cis-polybutadiene rubber 99-70 wt%, and unsaturated polymer material having at least one unsaturated double bond per repeating unit 0-20 wt% Vinyl cis-polybutadiene rubber (for example, WO 2006-54808).

  Moreover, a vulcanizing agent and a vulcanization accelerator can be added to the vulcanizable rubber (A). Examples of the vulcanizing agent include sulfur, a compound that generates sulfur by heating, an organic peroxide, a metal oxide such as magnesium oxide, a polyfunctional monomer, and a silanol compound. Examples of the compound that generates sulfur by heating include tetramethyl thiuram disulfide and tetraethyl thiuram disulfide.

  Examples of the vulcanization accelerator include aldehydes, ammonia, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, and xanthates, and more specifically, tetramethylthiuram. Disulfide (TMTD), N-oxydiethylene-2-benzothiazolylsulfenamide (OBS), N-cyclohexyl-2-benzothiazylsulfenamide (CBS), dibenzothiazyl disulfide (MBTS), 2-mercaptobenzo Examples include thiazole (MBT), zinc di-n-butyldithiocarbide (ZnBDC), and zinc dimethyldithiocarbide (ZnMDC).

  In addition, if necessary, known additives usually used in rubber compositions such as anti-aging agent, filler, process oil, zinc white, stearic acid and the like can be blended.

  Anti-aging agents include amine / ketone-based, imidazole-based, amine-based, phenol-based, sulfur-based and phosphorus-based anti-aging agents. More specifically, as an anti-aging agent, phenol-based 2,6-di-t-butyl-p-cresol (BHT), phosphorus-based trinonylphenyl phosphite (TNP), sulfur-based 4.6- Bis (octylthiomethyl) -o-cresol, dilauryl-3,3′-thiodipropionate (TPL) and the like can be mentioned.

  Fillers include inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, Lissajous, and diatomaceous earth, recycled fillers, and fillers such as powdered rubber. Process oils include aromatics, Examples include naphthenic and paraffinic process oils.

[Polyamide elastomer (B)]
In the polyamide elastomer (B) having a melting point of 100 to 180 ° C. used in the rubber composition according to the present invention, the hard segment is a polyamide, and the soft segment is a multi-block copolymer using polyether or polyester. The soft segment is preferably a polyether. The amide component is nylon 6,66,610,11,12, etc., representative examples of polyethers are diol poly (oxytetramethylene) glycol, poly (oxypropylene) glycol, etc., and typical examples of polyesters are poly (ethylene adipate). ) Glycol, poly (butylene-1,4 adipate) glycol, and the like. Examples of such polyamide elastomer (B) include polyether polyamide elastomers described in Japanese Patent No. 4123475 and polyether ester / amide block copolymers described in Japanese Patent Publication No. 56-45419.

  It is not preferable to use a polyamide elastomer having a melting point lower than 100 ° C. because it is inferior in heat resistance, and a melting point higher than 180 ° C. is not preferable because it does not melt and disperse when kneaded with rubber.

  The melting point of the polyamide elastomer (B) used in the present invention is 100 ° C to 180 ° C, more preferably 120 ° C to 170 ° C. The melting point can be adjusted by, for example, the ratio between the hard segment and the soft segment.

  The polyamide elastomer (B) used in the present invention preferably has a hardness (Shore D) of 30 to 65, and more preferably 35 to 60. The hardness can be adjusted by, for example, the ratio between the hard segment and the soft segment.

  Further, in the present invention, the amount of the polyamide elastomer (B) is 0.1 to 50 parts by weight, preferably 0.2 to 40 parts by weight, more preferably 0 to 100 parts by weight of the vulcanizable rubber (A). .3 to 30 parts by weight, particularly preferably 0.5 to 20 parts by weight. If the amount of the polyamide elastomer is less than 0.1 parts by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited.

  As the polyamide elastomer (B), in particular, a polyamide-forming monomer [that is, an aminocarboxylic acid compound (D1) and / or a lactam compound (D2)], an XYX type triblock polyetherdiamine compound (E) (Y is a polyoxy And a polyether polyamide elastomer obtained by polymerizing a dicarboxylic acid (F).

  In the polyether polyamide elastomer, the terminal carboxylic acid or carboxy group contained in the polyamide-forming monomer, XYX type triblock polyether diamine (E) and dicarboxylic acid (F) and the terminal amino group are approximately equimolar. A ratio such that

  In particular, when one end of the polyamide-forming monomer is an amino group and the other end is a carboxylic acid or a carboxy group, the XYX type triblock polyether diamine (E) and the dicarboxylic acid (F) are XYX type triblock poly The ratio is preferably such that the amino group of the ether diamine (E) and the carboxy group of the dicarboxylic acid (F) are approximately equimolar.

[Aminocarboxylic acid compound (D1) and lactam compound (D2)]
Next, the aminocarboxylic acid compound (D1) and the lactam compound (D2) will be described. The aminocarboxylic acid compound (D1) used in the present invention is a compound represented by the following formula (1).
^{_{H 2 N-R 1 -COOH (}} 1)

Here, R ¹ represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 2 to 20 carbon atoms or an alkylene group having 2 to 20 carbon atoms, More preferably, the hydrocarbon group having 3 to 18 carbon atoms or the alkylene group having 3 to 18 carbon atoms, more preferably the hydrocarbon group having 4 to 15 carbon atoms or the alkylene group having 4 to 15 carbon atoms, Particularly preferably, it represents the hydrocarbon group having 10 to 15 carbon atoms or the alkylene group having 10 to 15 carbon atoms.

The lactam compound (D2) used in the present invention is a compound represented by the following formula (2). Here, R ² represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 3 to 20 carbon atoms or an alkylene group having 3 to 20 carbon atoms, More preferably, the hydrocarbon group having 3 to 18 carbon atoms or the alkylene group having 3 to 18 carbon atoms, more preferably the hydrocarbon group having 4 to 15 carbon atoms or the alkylene group having 4 to 15 carbon atoms, Particularly preferably, it represents the above hydrocarbon group having 10 to 15 carbon atoms or an alkylene group having 10 to 15 carbon atoms.

  As the aminocarboxylic acid compound (D1) and the lactam compound (D2), at least one aliphatic or alicyclic group selected from ω-aminocarboxylic acid, lactam, or a compound synthesized from diamine and dicarboxylic acid and salts thereof And / or polyamide-forming monomers containing aromatics are used.

  Specific examples of ω-aminocarboxylic acids include carbon numbers such as 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 10-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples thereof include 5 to 20 aliphatic ω-aminocarboxylic acids.

  Specific examples of the lactam include ε-caprolactam, ω-enantolactam, ω-undecalactam, ω-dodecalactam, and aliphatic lactam having 5 to 20 carbon atoms such as 2-pyrrolidone.

  Examples of the diamine synthesized from diamine and dicarboxylic acid and salts thereof include at least one diamine compound selected from aliphatic diamine, alicyclic diamine and aromatic diamine, or derivatives thereof. . Examples of the dicarboxylic acid include at least one dicarboxylic acid compound selected from aliphatic dicarboxylic acid, alicyclic dicarboxylic acid and aromatic dicarboxylic acid, or derivatives thereof. In particular, by using a combination of an aliphatic diamine compound and an aliphatic dicarboxylic acid compound, a polyether polyamide elastomer having a low specific gravity, large tensile elongation, excellent impact resistance, and good melt moldability can be obtained. it can.

  The molar ratio of diamine to dicarboxylic acid (diamine / dicarboxylic acid) is preferably in the range of 0.9 to 1.1, more preferably in the range of 0.93 to 1.07, and in the range of 0.95 to 1.05. Is more preferable, and the range of 0.97 to 1.03 is particularly preferable. If this molar ratio is within the above range, high molecular weight can be easily achieved.

  Specific examples of the diamine include ethylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2, Examples thereof include diamine compounds such as aliphatic diamines having 2 to 20 carbon atoms such as 2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, and 3-methylpentamethylenediamine.

  Specific examples of the dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as dodecanedioic acid. The dicarboxylic acid compound can be mentioned.

[XYX type triblock polyether diamine (E)]
XYX type triblock polyether diamine (E) is a compound represented by the following formula (3), and after making propylene oxide by adding propylene oxide to both ends of poly (oxytetramethylene) glycol and the like, Polyether diamine produced by reacting ammonia at the end of this polypropylene glycol can be used.

  In the above formula (3), x and z are 1 to 20, preferably 1 to 18, more preferably 1 to 16, more preferably 1 to 14, particularly preferably 1 to 12, and y is 4 to 50. , Preferably 5 to 45, more preferably 6 to 40, more preferably 7 to 35, and particularly preferably 8 to 30. Further, as a combination of x, y and z, x is in the range of 2 to 6, y is in the range of 6 to 12, z is in the range of 1 to 5, or x is in the range of 2 to 10, and y is in the range of 13 to Preferred examples include a range of 28 and a combination of z in the range of 1-9.

  In the XYX type triblock polyether diamine (E), when x and z are each smaller than the above range, the resulting elastomer is inferior in transparency, which is not preferable. When y is smaller than the above range, rubber elasticity Is not preferable because of a low. Moreover, when x and z are larger than the said range, or when y is larger than the said range, since compatibility with a polyamide component becomes low and a tough elastomer is difficult to be obtained, it is not preferable.

  Specific examples of the XYX type triblock polyether diamine (E) include XTJ-533 manufactured by HUNTSMAN (USA) (in the general formula (3), x is approximately 12, y is approximately 11, and z is approximately 11), XTJ-536 (In general formula (3), x is about 8.5, y is about 17, and z is about 7.5), and XTJ-542 (in general formula (3), x is about 3, y is about 9, z is approximately 2).

  Further, as XYX type triblock polyether diamine (E), XYX-1 (general formula (3), x is about 3, y is about 14, z is about 2), XYX-2 (general formula (3) X is about 5, y is about 14, and z is about 4), and XYX-3 (in general formula (3), x is about 3, y is about 19, and z is about 2), etc. it can.

[Dicarboxylic acid compound (F)]
The dicarboxylic acid compound (F) used in the present invention is a compound represented by the following formula (4).
_{^{HOOC- (R 3) m -COOH (}} 4)

Here, R ³ represents a linking group containing a hydrocarbon chain, and is preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 20 carbon atoms or an alkylene group having 1 to 20 carbon atoms. And more preferably the hydrocarbon group having 1 to 15 carbon atoms or the alkylene group having 1 to 15 carbon atoms, more preferably the hydrocarbon group having 2 to 12 carbon atoms or the alkylene group having 2 to 12 carbon atoms. Particularly preferably, it represents the above hydrocarbon group having 4 to 10 carbon atoms or an alkylene group having 4 to 10 carbon atoms. M represents 0 or 1.

  As the dicarboxylic acid compound (F), at least one dicarboxylic acid selected from aliphatic, alicyclic and aromatic dicarboxylic acids or derivatives thereof can be used.

  Specific examples of the dicarboxylic acid include linear aliphatic dicarboxylic acids having 2 to 25 carbon atoms such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid. Or aliphatic dicarboxylic acids such as dimerized aliphatic dicarboxylic acids having 14 to 48 carbon atoms (dimer acid) obtained by dimerizing unsaturated fatty acids obtained by fractional distillation of triglycerides and hydrogenated products thereof (hydrogenated dimer acid) Mention may be made of acids, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid. As the dimer acid and hydrogenated dimer acid, trade names “Pripol 1004”, “Plipol 1006”, “Plipol 1009”, “Plipol 1013” and the like manufactured by Unikema Corporation can be used.

  The ratio of the polyamide-forming monomer to the total components of the polyether polyamide elastomer is preferably 10 to 95% by mass, more preferably 15 to 90% by mass, more preferably 15 to 85% by mass, and particularly preferably 15 to 80% by mass. %, Most preferably 15 to 70 mass. If the ratio of the polyamide-forming monomer to all the components of the polyether polyamide elastomer is 10% by mass or more, the crystallinity of the polyamide component can be improved, and mechanical properties such as strength and elastic modulus can be improved. Can do. If it is 95 mass% or less, the function and performance as elastomers, such as rubber elasticity and a softness | flexibility, can be expressed.

  Moreover, the ratio of the total amount of the (E) compound and the (F) compound with respect to all the components of the polyether polyamide elastomer is preferably 5 to 90% by mass, more preferably 10 to 85% by mass, and more preferably 15 to 85%. % By mass, particularly preferably 20 to 85% by mass, most preferably 30 to 85% by mass.

  The hardness (Shore D) of the polyether polyamide elastomer is preferably in the range of 30 to 65, more preferably in the range of 35 to 60. In the present invention, the hardness (Shore D) can be measured according to ASTM D2240.

  The flexural modulus of the polyether polyamide elastomer is preferably 20 to 450 MPa, more preferably 20 to 400 MPa, more preferably 20 to 350 MPa, and particularly preferably 20 to 300 MPa. When the elastic modulus is within the above range, an elastomer having particularly excellent toughness and rubber elasticity can be obtained. In the present invention, the flexural modulus can be measured according to ASTM D790.

  The tensile yield strength of the polyether polyamide elastomer is preferably in the range of 3-25 MPa, more preferably in the range of 3-22 MPa, more preferably in the range of 3-20 MPa, and particularly preferably in the range of 3-18 MPa. When the tensile yield point strength is in the above range, an elastomer having particularly excellent toughness and rubber elasticity can be obtained. In the present invention, the tensile yield point strength can be measured according to ASTM D-638.

  The tensile elongation at break of the polyether polyamide elastomer is preferably 300% or more, particularly preferably 600% or more. If the amount is less than this range, performance as an elastomer such as toughness and rubber elasticity becomes difficult to be exhibited, which may not be preferable. In the present invention, the tensile elongation at break can be measured according to ASTM D-638.

  The flexural strength of the polyether polyamide elastomer is preferably 0.8 to 15 MPa, more preferably 1 to 13 MPa, more preferably 1.1 to 10 MPa, and particularly preferably 1.2 to 9 MPa. When the bending strength of the polyether polyamide elastomer is within the above range, an elastomer having an excellent balance between toughness such as bending strength and rubber elasticity can be obtained. In the present invention, the bending strength can be measured according to ASTM D-790.

  It is preferable that the polyether polyamide elastomer is not broken (abbreviated as NB) in the measurement of impact strength with an Izod notch at 23 ° C., because it is particularly excellent in impact resistance. In the present invention, the impact strength with Izod notch can be measured in accordance with ASTM D-256.

  The deflection temperature under load of the polyether polyamide elastomer is preferably 50 ° C. or higher. Within the above range, the material is less likely to be deformed during use, which is preferable. In the present invention, the deflection temperature under load can be measured according to ASTM D-648.

  The relative viscosity (ηr) of the polyether polyamide elastomer is preferably in the range of 1.2 to 3.5 (0.5 mass / volume% metacresol solution, 25 ° C.).

[Method for producing polyether polyamide elastomer]
As an example of a method for producing a polyether polyamide elastomer, a polyamide-forming monomer (that is, an aminocarboxylic acid compound (D1) and / or a lactam compound (D2)), an XYX type triblock polyetherdiamine compound (E) and A method comprising a step of melt-polymerizing three components of dicarboxylic acid (F) under pressure and / or normal pressure, and further performing melt-polymerization under reduced pressure as required can be used. Further, a polyamide-forming monomer, XYX type Use a method comprising a step of simultaneously subjecting the three components of the triblock polyether diamine compound (E) and the dicarboxylic acid (F) to melt polymerization under pressure and / or normal pressure, and further performing melt polymerization under reduced pressure as necessary. Can do. A method of polymerizing the two components of the polyamide-forming monomer and the dicarboxylic acid (F) first and then polymerizing the XYX type triblock polyether diamine compound (E) can also be used.

  In the production of the polyether polyamide elastomer, there is no particular restriction on the raw material charging method, but the charging ratio of the polyamide-forming monomer, the XYX type triblock polyether diamine compound (E) and the dicarboxylic acid (F) is based on the total components. The polyamide-forming monomer is preferably 10 to 95% by mass, particularly preferably 15 to 90% by mass, and the XYX type triblock polyether diamine compound (E) is preferably 3 to 88% by mass, particularly preferably 8 to The range is 79% by mass. Among the raw materials, the XYX-type triblock polyether diamine compound (E) and the dicarboxylic acid (F) are approximately equimolar in the amino group of the XYX-type triblock polyether diamine compound (E) and the carboxy group of the dicarboxylic acid (F). It is preferable to prepare such that

  The polymerization temperature is preferably 150 to 300 ° C, more preferably 160 to 280 ° C, and particularly preferably 180 to 250 ° C. When the polymerization temperature is 150 ° C. or higher, the polymerization reaction proceeds favorably, and when it is 300 ° C. or lower, thermal decomposition is suppressed and a polymer having good physical properties can be obtained.

  The polyether polyamide elastomer can be produced by a method comprising a step of normal pressure melt polymerization or normal pressure melt polymerization followed by reduced pressure melt polymerization when ω-aminocarboxylic acid is used as the polyamide-forming monomer.

  On the other hand, when using a lactam or a diamine synthesized from a dicarboxylic acid and / or a salt thereof as a polyamide-forming monomer, an appropriate amount of water is allowed to coexist and melt polymerization under a pressure of 0.1 to 5 MPa is performed. And a subsequent method comprising normal pressure melt polymerization and / or reduced pressure melt polymerization.

  The polymerization time is usually 0.5 to 30 hours. If the polymerization time is 0.5 hours or more, the molecular weight can be increased, and if it is 30 hours or less, coloring due to thermal decomposition and the like can be suppressed, and a polyether polyamide elastomer having desired physical properties can be obtained. .

  The production of the polyether polyamide elastomer can be carried out batchwise or continuously, and a batch reactor, a single- or multi-tank continuous reactor, a tubular continuous reactor, etc. can be used alone or in combination. Can be used.

  When producing a polyether polyamide elastomer, monoamines and diamines such as laurylamine, stearylamine, hexamethylenediamine, and metaxylylenediamine, acetic acid, Monocarboxylic acids such as benzoic acid, stearic acid, adipic acid, sebacic acid and dodecanedioic acid, or dicarboxylic acids can be added. These used amounts are appropriately added so that the finally obtained polyether polyamide elastomer has a relative viscosity of 1.2 to 3.5 (0.5 mass / volume% metacresol solution, 25 ° C.). It is preferable.

  The addition amount of the above-mentioned monoamine and diamine, monocarboxylic acid and dicarboxylic acid is preferably set within a range that does not hinder the properties of the obtained polyether polyamide elastomer.

  When producing a polyether polyamide elastomer, phosphoric acid, pyrophosphoric acid, polyphosphoric acid, etc. are used as a catalyst as necessary, and phosphorous acid, hypophosphorous acid, for the effect of both the catalyst and the heat-resistant agent, Further, inorganic phosphorus compounds such as alkali metal salts and alkaline earth metal salts thereof can be added. The addition amount is usually 50 to 3000 ppm with respect to the charged raw materials.

  Other examples of the polyamide elastomer (B) include a polyamide elastomer of the formula (5).

In the formula ( 5 ), A is a polyamide sequence, B is a linear or branched aliphatic polyoxyalkylene glycol sequence, and the alkylene group has at least two carbon atoms, and n is an integer representing a repeating unit. . A method for producing a moldable and / or extrudable polyether ester amide block copolymer represented by the formula ( 5 ) comprises a dicarboxylic acid polyamide having a carboxylic acid group at a chain end and an average molecular weight of 300 to 15,000. , Reacting in a molten state with a linear or branched aliphatic polyoxyalkylene glycol having a hydroxyl group at the chain end and an average molecular weight of 200 to 6000, and the reaction is carried out at a temperature of 100 to 400 ° C. under high vacuum, A catalyst containing a tetraalkylorthotitanate represented by the general formula Ti (OR) ₄ (wherein R is a linear or branched aliphatic hydrocarbon group having 1 to 24 carbon atoms) is added to the reaction mixture. In contrast, it can be obtained by carrying out in an amount of 0.01 to 5% by weight (Japanese Patent Publication No. 56-45419). .

  Polyether polyamide elastomer is heat resistant agent, ultraviolet absorber, light stabilizer, antioxidant, antistatic agent, lubricant, slip agent, crystal nucleating agent, tackifier, and sealability improvement as long as its properties are not hindered. An agent, an antifogging agent, a release agent, a plasticizer, a pigment, a dye, a fragrance, a flame retardant, a reinforcing material, and the like can be added.

  Polyether polyamide elastomer has low water absorption, excellent melt moldability, excellent moldability, excellent toughness, excellent bending fatigue resistance, excellent rebound resilience, low specific gravity, and low temperature flexibility. Excellent low-temperature impact resistance, excellent stretch recovery, excellent sound deadening properties, excellent rubber properties and transparency.

  By a known molding method such as injection molding, extrusion molding, blow molding, and vacuum molding, a sheet-like molded article made of a polyether polyamide elastomer can be obtained.

  The polyether polyamide elastomer in the present invention is commercially available as “UBESTA XPA 9040X1, 9040F1, 9048X1, 9048F1, 9055X1, 9055F1, 9063X1, 9063F1, 9040X2, 9048X2, 9040F2, and 9048F2.” (Ube Industries, Ltd.) etc. can be used.

  The polyether polyamide elastomer has good compatibility with thermoplastic resins such as polyamide, polyvinyl chloride, thermoplastic polyurethane and ABS resin excluding the polyether polyamide elastomer used in the present invention, and should be blended with these thermoplastic resins. Thus, the moldability, impact resistance, elasticity and flexibility of these resins can be improved. The polyether polyamide elastomer has gas barrier properties, but the gas barrier properties can be further improved by mixing with other resins. Further, the polyether polyamide elastomer has an effect of accelerating vulcanization when added to rubber and vulcanized, and can contribute to improvement of productivity of rubber products.

[Inorganic reinforcing agent (C)]
Examples of the inorganic reinforcing agent (C) blended in the rubber composition according to the present invention include various carbon blacks, white carbon, silica, activated calcium carbonate, and ultrafine magnesium silicate. Among these, at least one of carbon black and silica is preferable. Particularly preferred is carbon black having a particle size of 90 nm or less and a dibutyl phthalate (DBP) oil absorption of 70 ml / 100 g or more. For example, FEF, FF, GPF, SAF, ISAF, SRF, and HAF are used.

Silica preferably has a silica purity of 97% or more. Silica having a purity of less than 97% does not have a sufficient rubber reinforcing effect, so that a rubber composition blended with such silica does not have sufficient wear resistance. The average particle size of the silica particles is preferably in the range of 0.1～50Myu m, more preferably 1～50Myu m, particularly preferably 5~50μ m. Such silica particles can be obtained, for example, by a method of pulverizing completely melted quartz glass to an appropriate particle size. Further, pulverized natural quartz having a silica purity of 97% or more is also preferably used. Furthermore, particles obtained by hydrolyzing an organosilicon compound such as silane are also preferably used.

  A coupling agent may be used so that the vulcanizable rubber (A) and silica are well mixed. As the coupling agent, an alkylphenol formaldehyde resin initial condensate, an acid anhydride, a silane coupling agent, and a titanate coupling agent are preferable, and a silane coupling agent is more preferable.

  Examples of silane coupling agents include alkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, diethoxydiethylsilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, dimethoxymethylphenylsilane, triethoxyethylsilane, and trimethoxyphenylsilane. , Trimethoxypropylsilane, phenyltriethoxysilane, hexyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, and N-dodecyltriethoxysilane.

  Including alkoxysilanes as described above, alkoxysilanes containing vinyl groups, alkoxysilanes having ester bonds, alkoxysilanes having epoxy groups, alkoxysilanes having amino groups, alkoxysilanes having mercapto groups, sulfide groups Examples include alkoxysilanes having chloro groups, alkoxysilanes having chloro groups, alkoxysilanes having styryl groups, alkoxysilanes having ureido groups, alkoxysilanes having isocyanate groups, and the like.

  Examples of alkoxysilanes having a vinyl group include vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinylsilane, vinylmethyldimethoxysilane, trichlorovinylsilane, allyltriethoxysilane, allyltrimethoxysilane, allyltrichlorosilane, and vinyltris. Alkoxysilanes having (2-methoxyethoxy) silaneacryloxy group or methacryloxy group, such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloxypropylmethyldiethoxysilane and 3-methacryloxypropylmethyldimethoxysilane.

  Examples of the alkoxysilanes having an ester bond include triacetoxymethylsilane and diacetoxydimethylsilane.

  Examples of alkoxysilanes having an epoxy group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyltriethoxysilane, and 3-glycol. Examples include cidoxypropyltrimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane.

  Examples of alkoxysilanes having an amino group include 3- (N-phenyl) aminopropyltrimethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyl Examples include methyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, and N- (vinylbenzyl) -2-aminoethyl-3-aminopropyl.

  Examples of alkoxysilanes having a mercapto group include 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

  Examples of alkoxysilanes having a sulfide group include 3-octanoylthio-1-propyltriethoxysilane and bis (triethoxysilylpropyl) tetrasulfide.

  Examples of alkoxysilanes having a chloro group include chloromethyltriethoxysilane, 3-chloropropyldimethoxymethylsilane, 3-chloropropyltrichlorosilane, 3-chloropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Chloropropyldimethoxymethylsilane, butyltrichlorosilane, chlorohexyltrichlorosilane, dodecaciltrichlorosilane, ethyltrichlorosilane, n-decyltrichlorosilane, n-octyltrichlorosilane, n-tetradecyltrichlorosilane, and phenyltrichlorosilane is there.

  Examples of alkoxysilanes having a styryl group include p-styryltrimethoxysilane.

  Examples of alkoxysilanes having a ureido group include 3-ureidopropyltriethoxysilane.

  Examples of alkoxysilanes having an isocyanate group include 3-isocyanatepropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, and tris- (3-trimethoxysilylpropyl) isocyanurate.

  A silane coupling agent may be used in combination of a plurality of the above compounds.

  The amount of the silane coupling agent used is preferably 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight, particularly preferably 2 to 30 parts per 100 parts by weight of the vulcanizable rubber (A). Parts by weight.

  In particular, an alkoxysilane having an amino group or an epoxy group is desirable.

  In addition, when a silane coupling agent having an amino group is used, it is effective for both a vulcanizable rubber such as SBR and a polyamide-based resin, and as a result, the compatibility between the two is activated. Since it increases, it is more preferable. Similarly, the same effect can be obtained with a silane coupling agent having an epoxy group.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of the carbon black / silica is preferably 90/10 to 5/95, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

  The amount of the inorganic reinforcing agent (C) used is 1 to 100 parts by weight, preferably 10 to 80 parts by weight, more preferably 20 to 70 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

[Other ingredients]
The rubber composition according to the present invention usually contains a vulcanizing agent, a vulcanization aid, an activator, an anti-scorch agent, an anti-aging agent, a filler, a process oil, zinc white, and stearic acid, if necessary. You may knead | mix the compounding agent used in the rubber industry.

  As the vulcanizing agent, known vulcanizing agents such as sulfur, organic peroxides, resin vulcanizing agents, and metal oxides such as magnesium oxide are used.

  As the vulcanization aid, known vulcanization aids such as aldehydes, ammonia, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, and xanthates are used.

  As the scorch inhibitor (retarder), organic acids, nitroso compounds, N-cyclohexylthiophthalimide, sulfonamide derivatives, and the like are used.

  Examples of the anti-aging agent include amine / ketone series, imidazole series, amine series, phenol series, sulfur series and phosphorus series.

  Examples of the filler include inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, Lissajous and diatomaceous earth, and organic fillers such as recycled rubber and powder rubber.

  The process oil may be any of aromatic, naphthenic, and paraffinic.

[Production of rubber composition]
The rubber composition according to the present invention is a condition in which the maximum temperature during kneading is equal to or higher than the melting point of the polyamide elastomer using a Banbury, an open roll, a kneader, a biaxial kneader or the like in which the above components are usually performed. It is obtained by kneading. The maximum temperature during kneading is preferably in the range of the same temperature as the melting point of the polyamide elastomer to a temperature higher by 50 ° C. than the melting point. More preferably, the temperature is 5 ° C higher than the melting point to 40 ° C higher than the melting point. If the maximum temperature during kneading is lower than the melting point of the polyamide elastomer, the polyamide elastomer does not melt and disperse, and if it is 50 ° C. higher than the melting point, the vulcanizable rubber may deteriorate.

[Use of rubber composition]
TECHNICAL FIELD The rubber composition according to the present invention relates to a rubber composition having high elasticity, high tensile strength, exothermic property, and excellent fatigue properties. Tire external members such as treads, sidewalls, chafers, etc. in tires, carcass belts・ Beads, inner liners and other tire internal components, anti-vibration rubber, rubber belts, hoses, seismic isolation rubber, fenders, and other industrial goods, men's shoes, women's shoes, and sports shoes, industrial and printing Rubber rolls for OA equipment, sports equipment such as golf balls, tennis balls and sports floors, solid tires for agriculture and forklifts, rubber crawlers, casters, sealing materials, adhesives, rubber sheets, waterproofing materials, packings, It can also be used for sponge products. The rubber composition is preferably used for a tire. Further, a rubber composition for a base tread, a rubber composition for a chafer, and a rubber composition for a sidewall, which will be described later, are preferable.

  Furthermore, when applied to an inner liner of a tire, a polyamide elastomer can be used as an adhesive layer between the carcass and the inner liner. Alternatively, in order to increase gas barrier properties, as an inner liner, polyamide elastomer resin or rubber, for example, halogenated butyl rubber, EVOH, low density polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetate, amorphous polyethylene terephthalate, which are known materials , Polyvinyl chloride, nylon 6, polyvinyl fluoride, polyvinylidene chloride, polyacrylonitrile, ethylene vinyl alcohol copolymer, polyvinyl alcohol, etc. can be used. In this case, the carcass and inner liner are directly laminated. You may do it.

Rubber composition for base tread:
Next, the base and the rubber composition for red according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the rubber composition for a base tread according to the present invention can be the same as those used in the above rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable.

  The vulcanizable rubber (A) used in the rubber composition for a base tread according to the present invention preferably contains SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent (C) used in the rubber composition for a base tread according to the present invention, the same one as that used in the above rubber composition can be used. However, the inorganic reinforcing agent (C) contains at least carbon black and silica, and the blending amount of silica in the inorganic reinforcing agent (C) is 80% by mass or less.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of carbon black / silica is preferably 95/5 to 20/80, more preferably 90/10 to 30/70, and particularly preferably 60/40 to 40/60. When the amount of silica is less than 5%, energy loss increases. When the amount is more than 80%, there is a drawback that workability and wear resistance are deteriorated.

  The amount of the inorganic reinforcing agent (C) used is 20 to 70 parts by weight, preferably 30 to 60 parts by weight, more preferably 35 to 55 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

[Wax (D)]
The rubber composition for a base tread according to the present invention preferably contains a wax in order to maintain ozone crack resistance of the tire groove bottom.

  The blending amount of the wax is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the vulcanizable rubber (A) from the viewpoint of good ozone crack resistance. 0.8 parts by weight or more is particularly preferable.

  Further, the blending amount of the wax is preferably 5 parts by weight or less, particularly preferably 3 parts by weight or less with respect to 100 parts by weight of the vulcanizable rubber (A) from the viewpoint of good wax blooming resistance.

  As the wax (D), it is particularly preferable to use a wax having a melting point of 60 ° C to 70 ° C.

  Specific examples of the wax (D) include Suntite S, R and E manufactured by Seiko Chemical Co., Ltd., and Sunnock N and P manufactured by Ouchi Shinsei Chemical Co., Ltd.

[Other ingredients]
In the rubber composition for a base tread according to the present invention, the same components as those used in the above rubber composition can be used as other components.

[Physical properties]
55-75 are preferable and, as for the JIS-A hardness of the rubber composition for base treads which concerns on this invention, 60-70 are especially preferable. When the hardness is less than 55, the steering stability tends to become unstable. When the hardness is 75 or more, the elongation at break tends to decrease.

  The tensile elongation of the rubber composition for base tread is preferably 350% to 600%, and more preferably 400% to 550%. If the tensile elongation of the rubber composition for a base tread is less than 350%, the target tire groove bottom cracks tend to grow, which is not preferable. On the contrary, when the tensile elongation is 600% or more, the exothermic property tends to deteriorate.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for base tread is preferably 0.1 or less. If it exceeds 0.1, fuel economy tends to be impaired. If tan δ is less than 0.03, fatigue may be deteriorated.

Chafer rubber composition:
Next, the chafer rubber composition according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the chafer rubber composition according to the present invention may be the same as those used in the above rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable. The vulcanizable rubber (A) preferably contains at least 30% by weight of natural rubber or polyisoprene rubber, and more preferably contains 40% by weight or more.

  The vulcanizable rubber (A) used in the chafer rubber composition according to the present invention preferably contains SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent (C) used in the chafer rubber composition according to the present invention, the same materials as those used in the above rubber composition can be used.

  The amount of the inorganic reinforcing agent (C) used is 60 to 100 parts by weight, preferably 60 to 90 parts by weight, more preferably 65 to 80 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

  When carbon black and silica used for the inorganic reinforcing agent are mixed, workability, low energy loss, wearability, and the like can both be achieved. Therefore, the inorganic reinforcing agent (C) is preferably a mixture of carbon black and silica. . In particular, the weight ratio of carbon black / silica is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

[Other ingredients]
As the other components used in the chafer rubber composition according to the present invention, the same components as those used in the above rubber composition can be used.

[Physical properties]
The JIS-A hardness of the chafer rubber composition according to the present invention is 70 or more, preferably 75 or more. If the JIS-A hardness of the rubber composition is less than 70, sufficient bead durability cannot be obtained. Further, the JIS-A hardness of the chafer rubber composition is 90 or less, preferably 85 or less. When the JIS-A hardness of the rubber composition exceeds 90, the elongation of the rubber composition is lowered.

  The vulcanization temperature of the chafer rubber composition is preferably 130 to 180 ° C. When the vulcanization temperature is less than 130 ° C., the vulcanization time becomes excessively long and the productivity is lowered. On the other hand, when the vulcanization temperature exceeds 180 ° C., it is difficult to make the elongation at break 180% or more, and when the tire is detached from the rim, the chafer tip of the bead portion is likely to be chipped.

  The breaking elongation of the chafer rubber composition is 180% or more, preferably 180% to 500%, and more preferably 250% to 400%. If the elongation at break of the chafer rubber composition is less than 180%, cracks at the tire groove bottom tend to grow, which is not preferable. Conversely, when the elongation at break exceeds 500%, the intended low heat build-up tends to be poor.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for chafer is preferably 0.2 or less. If it exceeds 0.2, fuel economy tends to be impaired. Note that if tan δ is less than 0.05, fatigue may be deteriorated.

Rubber composition for sidewalls:
Next, the rubber composition for a sidewall according to the present invention will be described.

[Vulcanizable rubber (A) and polyamide elastomer (B)]
The vulcanizable rubber (A) and polyamide elastomer (B) used in the rubber composition for a sidewall according to the present invention can be the same as those used in the rubber composition. However, the content of the polyamide elastomer (B) is 1 to 50 parts by weight, preferably 2 to 40 parts by weight, more preferably 3 to 100 parts by weight of the vulcanizable rubber (A). 30 parts by weight. If the amount of the polyamide elastomer (B) is less than 1 part by weight relative to 100 parts by weight of the vulcanizable rubber (A), the effect is not exhibited, and if it is more than 50 parts by weight, the workability deteriorates, which is not preferable.

  The vulcanizable rubber (A) used in the sidewall rubber composition according to the present invention preferably includes SPB-containing butadiene rubber or SPB-containing natural rubber in order to improve its strength. The blending amount of these SPB-containing butadiene rubber and SPB-containing natural rubber is preferably 1 to 30 parts by weight, particularly preferably 5 to 20 parts by weight, based on 100 parts by weight of the vulcanizable rubber (A).

[Inorganic reinforcing agent (C)]
As the inorganic reinforcing agent according to the present invention, the same materials as those used in the above rubber composition can be used.

  The amount of the inorganic reinforcing agent (C) used is 20 to 60 parts by weight, preferably 30 to 55 parts by weight, more preferably 40 to 50 parts by weight with respect to 100 parts by weight of the vulcanizable rubber (A). is there.

  When carbon black and silica used in the inorganic reinforcing agent (C) are mixed, it becomes possible to achieve both workability, low energy loss and wear properties, and the inorganic reinforcing agent (C) is a mixture of carbon black and silica. It is preferable. In particular, the weight ratio of carbon black / silica is preferably 90/10 to 10/90, more preferably 80/20 to 20/80, and particularly preferably 70/30 to 30/70. If the amount of silica is less than 10%, energy loss increases, and if it is more than 90%, there is a drawback that workability and wear resistance are deteriorated.

[Wax (D)]
The rubber composition for a sidewall according to the present invention preferably contains a wax in order to maintain ozone crack resistance at the tire groove bottom.

  The blending amount of the wax is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the vulcanizable rubber (A) from the viewpoint of good ozone crack resistance. 0.8 parts by weight or more is particularly preferable.

  Further, the blending amount of the wax is preferably 5 parts by weight or less (particularly 3 parts by weight or less with respect to 100 parts by weight of the vulcanizable rubber (A)) from the viewpoint of good wax blooming resistance.

  As the wax (D), it is particularly preferable to use a wax having a melting point of 60 ° C to 70 ° C.

  Specific examples of the wax (D) include Suntite S, R and E manufactured by Seiko Chemical Co., Ltd., and Sunnock N and P manufactured by Ouchi Shinsei Chemical Co., Ltd.

[Other ingredients]
In the rubber composition for a sidewall according to the present invention, the same components as those used in the above rubber composition can be used as other components.

[Physical properties]
The rubber composition for sidewalls according to the present invention has a JIS-A hardness of 55 to 75, preferably 60 to 70. When the JIS-A hardness is less than 55, the steering stability tends to be unstable. When the JIS-A hardness exceeds 75, the elongation at break tends to decrease.

  The breaking elongation of the rubber composition for a sidewall is preferably 300% to 700%, and more preferably 400% to 600%. If the breaking elongation of the rubber composition for sidewalls is less than 300%, cracks at the tire groove bottom tend to grow, which is not preferable. Conversely, when the elongation at break exceeds 700%, the intended low heat build-up tends to be poor.

  The tangent loss (tan δ) of viscoelasticity at 2% strain at 60 ° C. of the rubber composition for sidewall is preferably 0.15 or less. If it exceeds 0.15, fuel economy tends to be impaired. If tan δ is less than 0.03, fatigue may be deteriorated.

〔tire〕
The tire according to the present invention has the rubber composition for a base tread obtained in the present invention, so that the rolling resistance can be reduced without lowering the steering stability.

  Since the tire according to the present invention has the chafer rubber composition obtained in the invention, a tire excellent in exothermic property, elongation at break, hardness and fatigue and excellent in balance between them can be obtained.

  The tire according to the present invention can improve heat generation, chip cut resistance, hardness, and flex crack growth by having the rubber composition for a sidewall obtained in the invention.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In Examples and Comparative Examples, the physical properties of vulcanizable rubber and the properties of the resulting rubber composition and the vulcanized product were measured as follows.

[Rubber properties that can be vulcanized]
(1) Mooney viscosity (ML)
The Mooney viscosity (ML) was measured by a Mooney viscometer (SMV-202, manufactured by Shimadzu Corp.) in accordance with JIS-K6300 and preheated for 1 minute at 100 ° C. for 4 minutes.

(2) Intrinsic viscosity [η]
Intrinsic viscosity [η] is obtained by adding 0.1 g of sample rubber and 100 ml of toluene into an Erlenmeyer flask and completely dissolving them at 30 ° C., and then in a constant temperature water bath maintained at 30 ° C. 10 ml was added, the falling time (T) of the solution was measured, and the value obtained by the following formula was used.
ηsp = T / T0-1 (T0: falling time of toluene only)
ηsp / c = [η] + k ′ [η] 2c
(Ηsp: specific viscosity, k ′: Huggins constant (0.37), c: sample concentration (g / ml))

(3) Toluene solution viscosity (Tcp)
Toluene solution viscosity (Tcp) was obtained by dissolving 2.28 g of polymer in 50 ml of toluene, and using viscometer calibration standard solution (JIS-Z8809) as a standard solution. 400 was used and measured at 25 ° C.

(4) Microstructure The microstructure was analyzed by infrared absorption spectrum analysis. The microstructure was calculated from the absorption intensity ratio of cis 740 cm ⁻¹ , trans 967 cm ⁻¹ and vinyl 910 cm ⁻¹ .

(5) ηsp / c
ηsp / c was a reduced viscosity measured at 135 ° C. from a 0.20 g / dl o-dichlorobenzene solution as a measure of the molecular weight of 1.2 polybutadiene crystal fiber.

[Rubber properties after compounding]
The Mooney viscosity (ML1 + 4, 100 ° C.) was measured by a Mooney viscometer (SMV-202, manufactured by Shimadzu Corporation) in accordance with JIS-K6300, with a preheat 1 minute measurement at 100 ° C. for 4 minutes. The smaller the value, the lower the viscosity and the better the fluidity.

Die swell is a measure of the dimensional stability of the compound, using a processability measuring device (manufactured by Monsanto, MPT) at a shear rate of 100 ° C. and 100 sec ⁻¹ and the cross-sectional area of the compound during extrusion. The ratio of the die orifice cross-sectional area (where L / D = 1.5 mm / 1.5 mm) was measured. It shows that extrusion property is so favorable that a numerical value is small.

  Vulcanization characteristics (t90) were measured using a curator meter IIF manufactured by JSR Corporation at a temperature of 150 ° C. until the vulcanization torque reached 90%. The smaller the value, the shorter the vulcanization time. .

[Vulcanized physical properties]
The JIS-A hardness indicates that the hardness is higher as the numerical value is larger, measured with a type A durometer in accordance with the measurement method defined in JIS-K6253.

  Tensile stress measured 100% tensile stress according to JIS-K6251. The larger the value, the higher the tensile stress.

  As for the tensile strength, the tensile strength at break was measured according to JIS-K6251. It shows that tensile strength is so high that a numerical value is large.

  The elongation at break was measured by measuring the elongation at break according to JIS-K6251. It shows that breaking elongation is so large that a numerical value is large.

  The tear strength was measured according to JIS-K6252. It shows that tear strength is so high that a numerical value is large.

  The tensile fatigue test was performed using a tensile fatigue tester (manufactured by Yasuda Seiki Seisakusho), with a 0.5 mmφ scratch placed in the center of a dumbbell-shaped No. 3 (JIS-K6251) test piece, initial strain of 100%, 300 times / The number of times the test piece broke was measured under the condition of minutes. The larger the value, the better the stretch fatigue property.

  The exothermic property was measured according to the measurement method defined in JIS-K6265. The smaller the numerical value, the smaller the calorific value and the better.

  The loss factor (tan δ) was measured using RPA2000 (manufactured by Alpha Technologies) under the conditions of 60 ° C., 10 Hz, and 2% strain. The smaller the value, the smaller the energy loss and the better.

  The bending crack growth property was measured in accordance with JIS-K6260, and the crack length was measured when the movement distance of the specimen gripper was bent 10,000 times at 30 mm using a dimer bending tester (manufactured by Ueshima Seisakusho). It shows that bending crack growth resistance is so favorable that a numerical value is small.

  Abrasion was measured under the condition of a slip rate of 20% using a Lambourn abrasion tester specified in JIS-K6265. The smaller the numerical value, the smaller the amount of wear and the better.

  The oxygen permeability was measured under the conditions of 23 ° C. and 50% relative humidity using an oxygen gas permeation measuring device (MOCON-OX-TRAN 2/20 manufactured by Modern Control) according to ASTM-D3985. The smaller the value, the less oxygen permeation and the better the gas barrier property.

Hereinafter, the characteristic value of the polyether polyamide elastomer was measured as follows.
(1) Relative viscosity (ηr) (0.5 mass / volume% metacresol solution, 25 ° C.)
Using reagent-grade m-cresol as a solvent, it was measured at 25 ° C. using an Ostwald viscometer at a concentration of 5 g / dm ³ .

(2) Terminal carboxy group concentration ([COOH])
40 ml of benzyl alcohol was added to about 1 g of the polymer, heated and dissolved in a nitrogen gas atmosphere, phenolphthalein was added as an indicator to the obtained sample solution, and titrated with an N / 20 potassium hydroxide-ethanol solution.

(3) Terminal amino group concentration ([NH ₂ ])
About 1 g of the polymer was dissolved in 40 ml of a phenol / methanol mixed solvent (volume ratio: 9/1), thymol blue was added as an indicator to the obtained sample solution, and titrated with N / 20 hydrochloric acid.

(4) Melting point (Tm) and crystallization temperature (Tc)
Tm and Tc were measured under a nitrogen atmosphere using a differential scanning calorimeter DSC-50 manufactured by Shimadzu Corporation. The temperature was raised from room temperature to 230 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 230 ° C. for 10 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first run). Then, the temperature was raised to 230 ° C. at a rate of 10 ° C./min (referred to as a temperature raised second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(5) Composition The composition of the polyether polyamide elastomer was determined from a proton NMR spectrum measured at room temperature using JNM-EX400WB type FT-NMR manufactured by JEOL Ltd. at a concentration of 4% by mass using heavy trifluoroacetic acid as a solvent. The composition of each component was determined.

(6) Shore D hardness Shore D was measured according to ASTM D2240. It measured using the sheet | seat of thickness 6mm shape | molded by injection molding. The measurement was performed at a temperature of 23 ° C.

(7) Mechanical properties: Measurements (i) to (iv) shown below were performed by molding the following test pieces by injection molding.
(I) Tensile test (tensile yield point strength and tensile elongation at break): A Type I test piece described in ASTM D638 was measured according to ASTM D638.
(Ii) Bending test (flexural modulus and bending strength): Measured according to ASTM D790 using a test piece having a test piece size of 6.35 mm × 12.7 mm × 127 mm.
(Iii) Impact strength (with Izod notch): Measured at 23 ° C. in accordance with ASTM D256 using a test piece size of 12.7 mm × 12.7 mm × 3.5 mm.
(Iv) Deflection temperature under load: It was measured at a load of 0.45 MPa in accordance with ASTM D648 using a test piece having a test piece size of 6.35 mm × 12.7 mm × 127 mm.

Production Example 1 (Production of PAE1)
In a 70 liter pressure vessel equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator and polymer outlet, Ube Industries' 12-aminododecanoic acid 8.000 kg, ABA type Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) and 10.429 kg of adipic acid were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 8 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 12 kg of pellets. The obtained pellets are white tough and flexible polymers rich in rubber elasticity, ηr = 2.16, [COOH] = 1.28 × 10 ⁻⁵ eq / g, [NH ₂ ] = 1.86 × 10 ^{−. It was 5} eq / g, Mn = 63700, Tm = 135 ° C., Tc = 59 ° C. The polymer composition is PA12 / XTJ-542 / AA = 40.7 / 52.9 / 6.4 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 units XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 40, flexural modulus: 76 MPa, bending strength: 4.3 MPa, tensile yield strength: 6.3 MPa, tensile breaking elongation: 300% or more, impact strength: NB, load deflection temperature: 48 ° C.

Production Example 2 (Production of PAE2)
Ube Industries Co., Ltd. 12-aminododecanoic acid 11.200kg, ABA type in a 70 liter pressure vessel equipped with stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator and polymer outlet Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) and 7.121 kg of adipic acid were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 6 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 12 kg of pellets. The obtained pellet is a white tough and flexible polymer rich in rubber elasticity, ηr = 2.22, [COOH] = 1.61 × 10 ⁻⁵ eq / g, [NH ₂ ] = 2.17 × 10 ^{−. It was 5} eq / g, Mn = 52900, Tm = 154 ° C., Tc = 109 ° C. Polymer composition is PA12 / XTJ-542 / AA = 56.5 / 38.9 / 4.6 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 unit XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 48, flexural modulus: 132 MPa, bending strength: 7.2 MPa, tensile yield strength: 9.2 MPa, tensile breaking elongation: 300% or more, impact strength: NB, deflection temperature under load: 73 ° C.

Production Example 3 (Production of PAE3)
A 70-liter pressure vessel equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure regulator, and polymer outlet, Ube Industries, Ltd. 12-aminododecanoic acid 14.000 kg, ABA type Of triblock polyetherdiamine (manufactured by HUNTSMAN, trade name: XTJ-542) 5.236 kg and adipic acid 0.764 kg were charged. After sufficiently replacing the inside of the container with nitrogen, heating was gradually performed while supplying nitrogen gas at a flow rate of 300 liters / minute. The temperature was raised from room temperature to 230 ° C. over 3 hours, and polymerization was carried out at 230 ° C. for 6.5 hours. The pressure in the container was adjusted to 0.05 MPa after heating was started. Next, stirring was stopped, and the colorless and transparent polymer in a molten state was drawn out from the polymer takeout port into a string shape, cooled with water, and pelletized to obtain about 13 kg of pellets. The obtained pellet is a soft polymer with white toughness and rich rubber elasticity, ηr = 2.05, [COOH] = 2.48 × 10 ⁻⁵ eq / g, [NH ₂ ] = 2.82 × 10 ^{− It was 5} eq / g, Mn = 37700, Tm = 163 ° C., Tc = 123 ° C. The polymer composition is PA12 / XTJ-542 / AA = 70.1 / 26.6 / 3.3 (% by weight) (where PA12, XTJ-542 and AA represent each component in the polymer, PA12 is nylon 12 units XTJ-542 represents an ABA type triblock polyether diamine unit, and AA represents an adipic acid unit. The obtained pellets were injection molded to obtain samples for measuring various physical properties. The hardness and mechanical properties of the obtained sample are as follows.
Hardness: 55, flexural modulus: 232 MPa, bending strength: 11.9 MPa, tensile yield strength: 14.8 MPa, tensile breaking elongation: 300% or more, impact strength: NB, deflection temperature under load: 78 ° C.

Production Example 4 (Production of nano VCR)
(A) Preparation of vinyl cis-polybutadiene Content of nitrogen gas substituted in a 1.5 L stainless steel reaction vessel with a stirrer 1.0 L polymerization solution (butadiene: 31.5 wt%, 2-butenes: 28.8 wt%) , Cyclohexane; 39.7 wt%), water 1.7 mmol, diethylaluminum chloride 2.9 mmol, carbon disulfide 0.3 mmol, cyclooctadiene 13.0 mmol, and cobalt octoate 0.005 mmol are added, and at 60 ° C. The mixture was stirred for 20 minutes to perform 1,4 cis polymerization. Thereafter, 150 ml of butadiene, 1.1 mmol of water, 3.5 mmol of triethylalumonium chloride, and 0.04 mmol of cobalt octoate were added, and the mixture was stirred at 40 ° C. for 20 minutes to perform 1,2 syndiopolymerization. To this was added an anti-aging ethanol solution. Thereafter, unreacted butadiene and 2-butenes were removed by evaporation to obtain vinyl cis polybutadiene having a yield of 66 g and HI of 40.5%. Of this, 58 g of vinyl cis polybutadiene was dissolved in cyclohexane to prepare a vinyl cis polybutadiene slurry.

(B) Production of cis-polybutadiene In a 1.5 L stainless steel reactor equipped with a stirrer, the content was replaced with nitrogen gas, 1.0 L (butadiene; 31.5 wt%, 2-butenes; 28.8 wt%, Cyclohexane; 39.7 wt%), 1.7 mmol of water, 2.9 mmol of diethylaluminum chloride, 20.0 mmol of cyclooctadiene, and 0.005 mmol of cobalt octoate are added, and the mixture is stirred at 60 ° C. for 20 minutes. Cis polymerization was performed. The polymerization was stopped by adding an anti-aging agent ethanol solution thereto. Thereafter, unreacted butadiene and 2-butenes were removed by evaporation to obtain 81 g of cis-polybutadiene having a Mooney viscosity of 29.0 and a toluene solution viscosity of 48.3. This operation was carried out twice and a total of 162 g of cis-polybutadiene was dissolved in cyclohexane to prepare a cis-polybutadiene cyclohexane solution.

(A) + (B) Prototype of VCR Manufacture of VCR Contents Replaced with nitrogen gas 5.0L A stainless steel reaction vessel with a stirrer is charged with cis-polybutadiene cyclohexane solution in which 162 g of cis polybutadiene described above is dissolved. A vinyl cis polybutadiene cyclohexane slurry containing 58 g of vinyl cis polybutadiene described above was added with stirring. After adding the slurry, the mixture was stirred for 1 hour and then vacuum-dried at 105 ° C. for 60 minutes to obtain 220 g of nano VCR which is a mixture of (A) + (B).

  The ML of this nano-VCR was 62, and the content of 1.2 polybutadiene crystal fiber was 11.9%. The melting point of 1.2 polybutadiene crystal fiber was 203 ° C., ηsp / c was 1.7, the average fiber length was 156 nm, the aspect ratio was 2.8, and the number of crystal fibers was 123.

  ηsp / c was a reduced viscosity measured at 135 ° C. from a 0.20 g / dl o-dichlorobenzene solution as a measure of the molecular weight of 1.2 polybutadiene crystal fiber.

  1.2 The melting point and content of the polybutadiene crystal fiber were obtained by using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) to obtain an endothermic curve at a heating rate of 10 ° C./min. The content was calculated from the endothermic amount.

The average fiber length of crystal fibers, the number of crystal fibers having a fiber length of 200 nm or less, and the average aspect ratio of crystal fibers were determined as follows. The vinyl cis-polybutadiene rubber was vulcanized in a mixed solution of sulfur monochloride and carbon disulfide, and an ultrathin section was cut out from the vulcanized product with an ultramicrotome (manufactured by Leica). The section was observed with a transmission electron microscope (H-7100FA type, manufactured by Hitachi, Ltd.), and a 5000-times photograph was taken. The photograph was binarized in an area of 25 μm ² using image analysis software (Win ROOF (manufactured by Mitani Corporation)), and the fiber length, aspect ratio, and area of the crystal fiber were obtained. Next, the average fiber length and aspect ratio were averaged by multiplying the value of each crystal fiber by the area fraction to obtain the average fiber length of crystal fibers and the average aspect ratio of crystal fibers. The number of crystal fibers was determined by calculating the number of fibers having a fiber length of 200 nm or less per 1.2 mass% of polybutadiene crystal fiber content.

In addition, the symbol shown in the table | surface shown below is common in all the following tables | surfaces, and shows the following things.

(* 1) High-cis polybutadiene rubber manufactured by Ube Industries, Ltd. (* 2) UBESTA XPA9040X1 (melting point 135 ° C., hardness 40) manufactured by Ube Industries, Ltd.
(* 3) UBESTA XPA9048X1 (melting point 154 ° C, hardness 48) manufactured by Ube Industries, Ltd.
(* 4) UBESTA XPA9055X1 (melting point 163 ° C., hardness 55) manufactured by Ube Industries, Ltd.
(* 5) UBESTA XPA9068X1 (melting point 181 ° C, hardness 68) manufactured by Ube Industries, Ltd.
(* 6) Dia Black H manufactured by Mitsubishi Chemical Corporation
(* 7) High-cis polybutadiene rubber manufactured by Ube Industries, Ltd. (* 8) NipsilAQ manufactured by Tosoh Silica
(* 9) Degussa silane coupling agent (* 10) Ube Industries, Ltd. Reinforced polybutadiene rubber (* 11) Nano VCR manufactured in Production Example 4
(* 12) PEBAX 5533 manufactured by ARKMA (melting point 159 ° C, hardness 55)
(* 13) Suntite S manufactured by Seiko Chemical Co., Ltd.

[Rubber composition for sidewall]
Examples 39 to 42 and Comparative Examples 20 to 21
Next, Examples 39 to 42 and Comparative Examples 20 to 21 will be described. Among the formulation shown in Table 9, vulcanization accelerator, BR150 excluding sulfur (ML = 43, Tcp = 75), NR, PAE and compounding agent using 1.7 liter test Banbury mixer, start temperature The mixture was kneaded at 90 ° C. for 5 minutes to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are summarized in Table 9.

  From Table 9, the rubber compositions of Examples 39 to 42 have superior processability (small die swell), high elasticity, high tensile strength, high elongation at break, and excellent flex crack growth properties compared to Comparative Example 20. I understand. Moreover, since PAE used in Comparative Example 21 had a high melting point, it did not melt and disperse during kneading and remained in a pellet form.

Examples 43 to 48 and Comparative Examples 22 to 24
Next, Examples 43 to 48 and Comparative Examples 22 to 24 will be described. Among the compounding formulations shown in Table 10, VCR or BR150L (ML = 43, Tcp = 105) excluding sulfur, NR, PAE and compounding agent using a 1.7 liter Banbury mixer for testing. The mixture was kneaded for 5 minutes at a start temperature of 90 ° C. to obtain a primary kneaded product. At this time, the maximum kneading temperature was 170 ° C to 180 ° C. Next, the primary kneaded product was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll at 60 ° C. to obtain a secondary kneaded product. The die swell and vulcanization characteristics (t90) of the obtained secondary kneaded product were measured. Next, the secondary kneaded product was placed in a mold and press vulcanized at 150 ° C. for (t90 × 3) minutes to obtain a vulcanized product. The physical properties of the obtained vulcanizate were measured, and the results are summarized in Table 10.

  From Table 10, it can be seen that the physical properties are further improved in a well-balanced manner by combining the polyamide elastomer with the VCR or nano-VCR. Further, Comparative Example 23 with a small amount of the inorganic reinforcing agent is not sufficient in hardness, tensile strength, and elongation at break, and Comparative Example 24 with a large amount is inferior in heat generation and flex crack growth. .

Claims (37)

  It contains 0.1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 1 to 100 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of the vulcanizable rubber (A). A rubber composition.   The rubber composition according to claim 2, wherein the soft segment of the polyamide elastomer (B) is a polyether.   3. The rubber composition according to claim 1, wherein the polyamide elastomer (B) has a hardness (Shore D) of 30 to 65. 4.   The rubber composition according to any one of claims 1 to 3, wherein the inorganic reinforcing agent (C) contains at least carbon black (Ca) or silica (Cb).   The rubber composition according to any one of claims 1 to 4, wherein the rubber composition is produced by melt-kneading the vulcanizable rubber (A) and the polyamide lastomer (B).   The inorganic reinforcing agent (C) is a mixture of carbon black (Ca) and silica (Cb), and the weight ratio of carbon black (Ca) to silica (Cb) is 90/10 to 5 6. The rubber composition according to claim 1, wherein the rubber composition is / 95.   7. The vulcanizable rubber (A) comprises vinyl cis-butadiene rubber which is cis-1,4-polybutadiene containing syndiotactic 1,2-polybutadiene. A rubber composition as described above. The vinyl cis-butadiene rubber is a specific syndiotactic-1, 2 having a crystal fiber having an average long axis length of 200 nm or less of 90 or more per 25 μm ² and a melting point of 170 ° C. or more. A vinyl cis comprising 1 to 30% by weight of polybutadiene crystal fibers, 99 to 70% by weight of cis-polybutadiene rubber, and 0 to 20% by weight of an unsaturated polymer having at least one unsaturated double bond per repeating unit. The rubber composition according to claim 7, which is a polybutadiene rubber.   A rubber composition for tires, wherein the rubber composition according to any one of claims 1 to 8 is used for tires. Containing 100 parts by weight of vulcanizable rubber (A), 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 70 parts by weight of an inorganic reinforcing agent (C),
A rubber composition for a base tread, wherein the inorganic reinforcing agent (C) contains at least carbon black and silica, and the amount of silica in the inorganic reinforcing agent (C) is 80% by mass or less.   Furthermore, 0.1-5 weight part of wax (D) whose melting | fusing point is 60 degreeC or more is mix | blended, The rubber composition for base treads of Claim 10 characterized by the above-mentioned.   The rubber composition for base tread according to claim 10 or 11, wherein the soft segment of the polyamide elastomer (B) is a polyether.   The rubber composition for base tread according to any one of claims 10 to 12, wherein the polyamide elastomer (B) has a hardness (Shore D) of 30 to 65.   The rubber composition for a base tread according to any one of claims 10 to 13, wherein the rubber composition (A) and the polyamide lastmer (B) that can be vulcanized are melt-kneaded.   A base tread comprising the rubber composition for a base tread according to any one of claims 10 to 14.   A tire for a passenger car having the base tread according to claim 15.   A studless tire having the base tread according to claim 15.   A tire having the base tread according to claim 15. Containing 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 60 to 100 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of the vulcanizable rubber (A),
A rubber composition for chafers having a JIS-A hardness of 70 to 90 and an elongation at break in a tensile test of 180% or more.   The rubber composition for chafer according to claim 19, wherein the soft segment of the polyamide elastomer (B) is a polyether.   21. The chafer rubber composition according to claim 19 or 20, wherein the polyamide elastomer (B) has a hardness (Shore D) of 30 to 65.   The rubber composition for chafers according to any one of claims 19 to 21, wherein the vulcanizable rubber (A) contains at least 30% by weight of natural rubber or polyisoprene rubber.   The rubber composition for a chafer according to any one of claims 19 to 22, wherein the rubber composition is produced by melt-kneading a vulcanizable rubber (A) and a polyamide lastmer (B).   A chafer comprising the rubber composition for a chafer according to any one of claims 19 to 23.   A tire for a passenger car having the chafer according to claim 24.   A studless tire having the chafer according to claim 24.   A tire having the chafer according to claim 24. Containing 1 to 50 parts by weight of a polyamide elastomer (B) having a melting point of 100 to 180 ° C. and 20 to 60 parts by weight of an inorganic reinforcing agent (C) with respect to 100 parts by weight of the vulcanizable rubber (A),
A rubber composition for a sidewall, having a JIS-A hardness of 55 to 75.   Furthermore, 0.1-5 weight part of wax (D) whose melting | fusing point is 60 degreeC or more is mix | blended, The rubber composition for sidewalls of Claim 28 characterized by the above-mentioned.   30. The rubber composition for a side wall according to claim 28, wherein the soft segment of the polyamide elastomer (B) is a polyether.   The rubber composition for a sidewall according to any one of claims 28 to 30, wherein the polyamide elastomer (B) has a hardness (Shore D) of 30 to 65.   32. The rubber composition for a sidewall according to claim 28, wherein the rubber component of the vulcanizable rubber (A) contains 30% by weight or more of natural rubber.   The rubber composition for a side wall according to any one of claims 28 to 32, which is produced by melt-kneading a vulcanizable rubber (A) and a polyamide lastmer (B).   A sidewall comprising the rubber composition for a sidewall according to any one of claims 28 to 33.   A tire for a passenger car having the sidewall according to claim 34.   A studless tire having the sidewall according to claim 34.   A tire having the sidewall according to claim 34.