JP2020084061A - Rubber composition and method for producing the same - Google Patents

Abstract

To provide a vulcanized rubber composition that can improve the dispersibility of carbonaceous material, and can achieve both of mechanical properties such as hardness and strength and flexibility such as elongation at high levels.SOLUTION: A rubber composition is prepared by combination of a rubber component (A), a fluorene compound (B) having a 9,9-bis(aryl) fluorene skeleton, and a carbonaceous material (C) (where, ring Z is an arene ring, Rand Rare substituents, Xis a hetero atom-containing functional group, k is an integer of 0-4, n is an integer of 1 or greater, p is an integer of 0 or greater).SELECTED DRAWING: None

Description

The present invention relates to a rubber composition containing a compound having a 9,9-bisarylfluorene skeleton and a carbonaceous material, and a method for producing the same.

Since rubber is excellent in elasticity, it is used as a material for molded products in various applications requiring elasticity. However, since it is required to have mechanical properties such as hardness and rigidity depending on the application, carbonaceous materials such as carbon black are used. Materials are often compounded as reinforcing agents. However, since there is a trade-off relationship between flexibility such as elasticity and elongation and mechanical properties such as hardness and rigidity, it is difficult to make both properties highly compatible in a vulcanized rubber composition.

On the other hand, in JP-A-2005-290113 (Patent Document 1), as a compatibilizer that can secure practical physical properties even when a plastic material is recycled by using a plurality of types of polymers containing a flame retardant and an inorganic filler, A compatibilizer composed of a compound having a fluorene skeleton is disclosed. In this document, examples of polymers to which the compatibilizing agent is applied include thermoplastic resins, thermoplastic elastomers, rubbers, and thermosetting resins. In the examples, waste polyethylene terephthalate (PET flakes) and polyethylene gas pipe waste material pellets are blended with fluorene-based polyester and molded, and the tensile yield strength is measured.

However, in this document, a study on a vulcanized rubber composition containing a carbonaceous material is not specifically made.

JP-A-2005-290113 (Claim 1 and paragraphs [0012][0097], Example)

Therefore, an object of the present invention is to provide a rubber composition capable of improving the dispersibility of a carbonaceous material and highly compatible with mechanical properties such as hardness and strength and flexibility such as elongation, and a method for producing the same. Especially.

Another object of the present invention is to provide a rubber composition capable of achieving a high degree of compatibility between mechanical properties such as hardness and strength and flexibility such as elongation even when the carbonaceous material is fine, and a method for producing the same. It is in.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have combined a compound having a 9,9-bis(aryl)fluorene skeleton and a carbonaceous material into a rubber component to form a vulcanized rubber composition. The inventors have found that the dispersibility of a carbonaceous material in an object can be improved and mechanical properties such as hardness and strength and flexibility such as elongation can be highly compatible with each other, and the present invention has been completed.

That is, the rubber composition of the present invention contains a rubber component (A), a fluorene compound (B) having a 9,9-bis(aryl)fluorene skeleton, and a carbonaceous material (C). The fluorene compound (B) may be a compound represented by the following formula (1).

(In the formula, ring Z is an arene ring, R ¹ and R ² are substituents, X ¹ is a heteroatom-containing functional group, k is an integer of 0 to 4, n is an integer of 1 or more, and p is an integer of 0 or more. Shown).

In the formula (1), X ¹ may be a group —[(OA) _m1 —OH] (in the formula, A represents an alkylene group and m1 represents an integer of 0 or more). The rubber component (A) may be a diene rubber (in particular, a diene rubber having an aromatic skeleton). The carbonaceous material (C) may be carbon black. The ratio of the fluorene compound (B) may be 1 to 30 parts by mass with respect to 100 parts by mass of the rubber component (A). The ratio of the carbonaceous material (C) may be 10 to 300 parts by mass with respect to 100 parts by mass of the rubber component (A). The rubber composition of the present invention may be a vulcanized vulcanized rubber composition.

The present invention also includes a method for producing the rubber composition, which includes a kneading step of kneading the rubber component (A), the fluorene compound (B) and the carbonaceous material (C). This manufacturing method may further include a vulcanization step of vulcanizing the kneaded composition obtained in the kneading step to obtain a vulcanized rubber composition.

In the present invention, the rubber component, the compound having the 9,9-bis(aryl)fluorene skeleton, and the carbonaceous material are combined, so that the carbonaceous material can be uniformly dispersed in the vulcanized rubber composition, and the hardness and hardness can be improved. Mechanical properties such as strength can be highly compatible with flexibility such as elongation. Further, even if the carbonaceous material is a fine carbonaceous material such as carbon black, it is possible to achieve both the mechanical characteristics and the flexibility.

The rubber composition of the present invention contains a rubber component (A), a fluorene compound (B) having a 9,9-bis(aryl)fluorene skeleton, and a carbonaceous material (C).

[Rubber component (A)]
The rubber component (A) is not particularly limited, and a commonly used rubber component can be used. Examples of commonly used rubber components include diene rubber, olefin rubber, acrylic rubber (ACM, ANM), butyl rubber (IIR), epichlorohydrin rubber (CO), polysulfide rubber (OT, EOT), urethane rubber. (U), silicone rubber (Q), fluororubber (FFKM, FKM), sulfur-containing rubber and the like. These rubber components may be used alone or in combination of two or more. Among these rubber components, a diene rubber and/or an olefin rubber is preferable because the effect of improving the dispersibility of the carbonaceous material (C) by the fluorene compound (B) is great.

Examples of the diene rubber include natural rubber (NR), epoxidized natural rubber, polybutadiene [eg, butadiene rubber (BR), 1,2-polybutadiene (VBR), etc.], isoprene rubber (IR), chloroprene rubber (CR). ), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), and the like. These diene rubbers may be hydrogenated rubbers (for example, hydrogenated BR, hydrogenated NBR, hydrogenated SBR, etc.). These diene rubbers can be used alone or in combination of two or more.

Examples of the olefin rubber include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), ethylene-butene rubber, ethylene-1-butene-diene rubber, propylene-1-butene-diene rubber, polyisobutylene rubber, ethylene. -Vinyl acetate rubber, maleic acid modified ethylene-propylene rubber (M-EPM), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorinated polyethylene (M-CM) and the like. Examples of the diene unit (non-conjugated diene unit) contained in the olefin rubber include units derived from dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, and the like. These olefin rubbers can be used alone or in combination of two or more.

The copolymer rubber may be a random or block copolymer, and the block copolymer includes a copolymer having an AB type, ABA type, taper type, radial teleblock type structure, and the like. ..

Of these, diene rubbers such as SBR and NBR and olefin rubbers such as EPDM are preferable, and diene rubbers are particularly preferable. Further, among the diene rubbers, the diene rubbers having an aromatic skeleton or aromatic ring such as SBR have a high compatibility with the fluorene compound (B) and a large effect of improving the dispersibility of the carbonaceous material (C). Rubber is particularly preferred.

[Fluorene compound (B)]
The fluorene compound (B) only needs to have a 9,9-bis(aryl)fluorene skeleton, and may be a resin component having a fluorene skeleton (for example, polyester having a fluorene skeleton). The compound represented by the above formula (1) is preferable because it is easily dispersed in a substance and has a large effect of improving the dispersibility of the carbonaceous material (C).

In the above formula (1), examples of the arene ring represented by ring Z include a monocyclic arene ring such as a benzene ring and a polycyclic arene ring. The polycyclic arene ring includes a condensed polycyclic arene ring. A ring (fused polycyclic aromatic hydrocarbon ring), a ring-collecting arene ring (ring-collecting aromatic hydrocarbon ring), and the like are included.

Examples of the condensed polycyclic arene ring include a condensed bicyclic arene ring (for example, a condensed bicyclic C _10-16 arene ring such as a naphthalene ring) and a condensed tricyclic arene ring (for example, an anthracene ring, phenanthrene ring). Ring etc.) and the like bi- to tetracyclic arene ring and the like. Examples of preferable fused polycyclic arene ring include naphthalene ring and anthracene ring, and naphthalene ring is particularly preferable.

Examples of the ring-collecting arene ring include a biarene ring [eg, biphenyl ring, binaphthyl ring, phenylnaphthalene ring (eg, 1-phenylnaphthalene ring, 2-phenylnaphthalene ring, etc.) and other biC _6-12 arene ring], terarene Examples thereof include a ring (for example, a ter C _6-12 arene ring such as a terphenylene ring). Preferred ring-assembled arene rings include biC _6-10 arene rings, especially biphenyl rings.

The two rings Z substituting at the 9-position of fluorene may be different or the same, but usually they are often the same ring. Of the ring Z, a benzene ring, a naphthalene ring, a biphenyl ring (particularly a benzene ring) and the like are preferable.

The substitution position of ring Z substituting at the 9-position of fluorene is not particularly limited. For example, when the ring Z is a naphthalene ring, the group corresponding to the ring Z substituting at the 9-position of fluorene may be a 1-naphthyl group, a 2-naphthyl group or the like.

Examples of the hetero atom-containing functional group represented by X ¹ include a functional group having at least one hetero atom selected from oxygen, sulfur and nitrogen atoms. The number of heteroatoms contained in such a functional group is not particularly limited, but may be usually 1 to 3, preferably 1 or 2.

Examples of the functional group, for example, group ^{_{- [(OA) m1 -Y 1}} ] ( wherein, ^{Y 1} is a hydroxyl group, glycidyloxy group, an amino group, N-substituted amino group or a mercapto group, A is an alkylene group , M1 is an integer of 0 or more), a group —(CH ₂ ) _{m 2} —COOR ³ (in the formula, R ³ is a hydrogen atom or an alkyl group, and m 2 is an integer of 0 or more).

Group - in ^{_{[(OA) m1 -Y 1]}} , as the N-substituted amino group of ^{Y 1,} for example, N- monoalkylamino group (N- mono _{C 1-4} alkylamino group such as methylamino, ethylamino group Etc.) and N-monohydroxyalkylamino groups such as hydroxyethylamino groups (N-monohydroxyC _1-4 alkylamino groups etc.) and the like.

The alkylene group A includes a linear or branched alkylene group. Examples of the linear alkylene group include C _2-6 alkylene groups such as ethylene group, trimethylene group and tetramethylene group. Of these, a linear C _2-3 alkylene group is preferable, a linear C _2-3 alkylene group is more preferable, and an ethylene group is most preferable. Examples of the branched alkylene group include a branched C _3-6 alkylene group such as a propylene group, a 1,2-butanediyl group and a 1,3-butanediyl group. Of these, a branched C _3-4 alkylene group is preferable, and a propylene group is particularly preferable.

M1 which shows the repeating number of an oxyalkylene group (OA) can be selected from the range of 0 or more (for example, 0-15, preferably about 0-10), for example, 0-8 (for example, 1-8), preferably 0-. 5 (for example, 1 to 5), more preferably 0 to 4 (for example, 1 to 4), particularly 0 to 3 (for example, 1 to 3), and usually 0 to 2 (for example, 0 to 1). Alternatively, 1 is the most preferable. Also when the repeating number is the average number of added moles, it can be selected from the above range. When m1 is 2 or more, the types of the alkylene group A may be the same or different. Further, the types of the alkylene group A may be the same or different in the same or different ring Z.

Group - in (CH _{2) m2} -COOR ^3, the alkyl group represented by ^{R 3,} methyl, ethyl, propyl, isopropyl, butyl, straight or branched chain, such as t- butyl group _Examples include a C _1-6 alkyl group and the like. Of these, a C _1-4 alkyl group is preferable, and a C _1-2 alkyl group is particularly preferable. M2 indicating the number of repeating methylene groups may be 0 or an integer of 1 or more, and is, for example, 1 to 6, preferably 1 to 4, and more preferably 1 to 2. m2 may be 0 or 1-2. When the repeating number is the average number of moles added, the number can be selected from the range.

Among these, the group X ¹ is a group —[(OA) _{m 1} —OH] (in the formula, A is an alkylene group) because it has a large effect of improving the dispersibility of the carbonaceous material (C) and is excellent in handleability. , M1 is an integer of 0 or more), and a group —[(OA) _m1 —OH] (in the formula, A is a C _2-4 alkylene group such as ethylene group, m1 is an integer of 0 to 5). but more preferably the group _{- [(OA) m1 -OH]} ( wherein, a is _{C 2-3} alkylene group such as ethylene group, m1 is 0 or 1) are most preferred.

In the formula (1), n indicating the number of the groups X ¹ substituted on the ring Z is 1 or more, preferably 1 to 3, more preferably 1 or 2, and most preferably 1. The number of substitutions n may be the same or different in each ring Z.

The group X ¹ can be substituted at any suitable position on the ring Z, for example when the ring Z is a benzene ring, it can be substituted at the 2,3,4 position, preferably the 3 and/or 4 position of the phenyl group. In many cases, when the ring Z is a naphthalene ring, it is often substituted at any of the 5 to 8 positions of the naphthyl group, for example, the 1 position of the naphthalene ring with respect to the 9 position of fluorene. Or substituted at the 2-position (substituting in the relationship of 1-naphthyl or 2-naphthyl), and the relationship of 1,5-position, 2,6-position, etc., with respect to this substitution position, particularly when n is 1, 2 In many cases, the group X ¹ is substituted due to the 6-position. Further, when n is 2 or more, the substitution position is not particularly limited. Further, in the ring-assembled arene ring Z, the substitution position of the group X ¹ is not particularly limited, and, for example, even if it is substituted with an arene ring bonded to the 9-position of fluorene and/or an arene ring adjacent to this arene ring. Good. For example, the 3-position or 4-position of the biphenyl ring Z may be bonded to the 9-position of fluorene, and when the 3-position of the biphenyl ring Z is bonded to the 9-position of fluorene, the substitution position of the group X ¹ is It may be at any of the 2,4,5,6,2′,3′,4′ positions, and preferably may be substituted at the 6 position.

In the above formula (1), the substituent R ² may be a non-reactive group. The substituent R ² is a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom; an alkyl such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group or a t-butyl group. Group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, methylphenyl group (tolyl group), dimethylphenyl group (xylyl group), biphenyl group, naphthyl group; benzyl group, phenethyl group, etc. Aralkyl group; methoxy group, ethoxy group, propoxy group, n-butoxy group, isobutoxy group, t-butoxy group and other alkoxy groups; phenoxy group and other aryloxy groups; cyclohexyloxy group and other cycloalkyloxy groups; phenoxy Groups such as aryloxy groups; benzyloxy groups such as aralkyloxy groups; methylthio groups such as alkylthio groups; cyclohexylthio groups such as cycloalkylthio groups; thiophenoxy groups such as arylthio groups; benzylthio groups such as aralkylthio groups; acetyl And acyl groups such as groups; nitro groups; cyano groups; and substituted amino groups such as methylamino groups. These substituents can be used alone or in combination of two or more.

Of these substituents R ² , typically, a halogen atom, a hydrocarbon group (alkyl group, cycloalkyl group, aryl group, aralkyl group), an alkoxy group, an acyl group, a nitro group, a cyano group, a substituted amino group. And so on. Of these substituents R ² , a linear or branched C _1-4 alkyl group and a linear or branched C _1-4 alkoxy group are preferable, and a linear or branched chain such as a methyl group is preferable. Particularly preferred is a C _1-3 alkyl group. When the substituent R ² is an aryl group, the substituent R ² together with the ring Z may form the ring-collecting arene ring. The types of the substituents R ² may be the same or different in the same or different ring Z.

The coefficient p of the substituent R ² can be appropriately selected depending on the kind of the ring Z, and can be selected from an integer of, for example, about 0 to 8, for example, 0 to 4, preferably 0 to 3, and more preferably 0 to 2, Most preferably, it is 0 or 1. In particular, when p is 1, the ring Z may be a benzene ring, a naphthalene ring or a biphenyl ring, and the substituent R ² may be a methyl group.

As the substituent R ¹ , a cyano group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), a carboxyl group, an alkoxycarbonyl group (for example, a C _1-4 alkoxy-carbonyl group such as a methoxycarbonyl group), an alkyl Examples thereof include groups (C _1-6 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group) and aryl groups (C _6-10 aryl groups such as phenyl group). The substituent R ¹ may be a non-reactive group. These substituents can be used alone or in combination of two or more.

Among these substituents R ¹ , a carboxyl group, a linear or branched C _1-4 alkyl group, a C _1-4 alkoxy-carbonyl group, a cyano group and a halogen atom are preferable, and a C _1- group such as a methyl group. _{A 3-} alkyl group is particularly preferred. The substitution number k can be selected from an integer of 0 to 4, and is, for example, 0 to 3, preferably 0 to 2, more preferably 0 or 1, and most preferably 0. The substitution numbers k may be the same or different from each other, and when k is 2 or more, the types of the substituents R ¹ may be the same or different from each other, and the two benzene rings of the fluorene ring are substituted. The types of the substituents R ¹ may be the same or different. The substitution position of the substituent R ¹ is not particularly limited, and may be the 2-position to the 7-position (eg, 2-position, 3-position and/or 7-position) of the fluorene ring.

Among these, as a preferable fluorene compound, when the group X ¹ is a group —[(OA) _{m 1} —OH], for example, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis( 9,9-bis(hydroxy C _6-12 aryl)fluorene such as 5-hydroxy-1-naphthyl)fluorene and 9,9-bis(6-hydroxy-2-naphthyl)fluorene; 9,9-bis(3,3) 9,9-bis(di- or trihydroxy C _6-12 aryl)fluorene such as 4-dihydroxyphenyl)fluorene; 9,9-bis(such as 9,9-bis(3-methyl-4-hydroxyphenyl)fluorene. Mono or di C _1-4 alkyl-hydroxy C _6-12 aryl)fluorene; 9,9-bis(3-phenyl-4-hydroxyphenyl)fluorene, 9,9-bis(4-phenyl-3-hydroxyphenyl) 9,9-Bis(C _6-12 aryl-hydroxy C _6-12 aryl)fluorene such as fluorene; 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, 9,9-bis[6- (2-hydroxyethoxy) -2-naphthyl] fluorene such as 9,9-bis (hydroxy _{(poly) C 2-4} alkoxy _{-C 6-12} aryl) fluorene; 9,9-bis [3-methyl-4- 9,2-Bis(C _1-4 alkyl-hydroxy(poly)C _2-4 alkoxy-C _6-12 aryl)fluorene such as (2-hydroxyethoxy)phenyl]fluorene; 9,9-bis[3-phenyl 4,5-(2-hydroxyethoxy)phenyl]fluorene, 9,9-bis[4-phenyl-3-(2-hydroxyethoxy)phenyl]fluorene and other 9,9-bis(C _6-12 aryl-hydroxy( And poly)C _2-4 alkoxy-C _6-12 aryl)fluorene and the like.

These fluorene compounds (B) can be used alone or in combination of two or more. In addition, "(poly)alkoxy" is used to mean both an alkoxy group and a polyalkoxy group.

The ratio of the fluorene compound (B) can be selected from the range of about 1 to 30 parts by mass with respect to 100 parts by mass of the rubber component (A), and for example, 2 to 25 parts by mass, preferably 3 to 20 parts by mass, and more preferably It is about 5 to 15 parts by mass (particularly 8 to 12 parts by mass). If the proportion of the fluorene compound (B) is too small, the dispersibility of the carbonaceous material (C) may decrease, and if it is too large, rubber properties such as elasticity may deteriorate.

The ratio of the fluorene compound (B) can be selected from the range of about 1 to 50 parts by mass with respect to 100 parts by mass of the carbonaceous material (C), and for example, 3 to 40 parts by mass, preferably 4 to 30 parts by mass, and more preferably Is about 5 to 25 parts by mass (particularly 10 to 20 parts by mass). If the proportion of the fluorene compound (B) is too small, the dispersibility of the carbonaceous material (C) may decrease, and if it is too large, mechanical properties such as hardness may deteriorate.

[Carbonaceous material (C)]
Examples of the carbonaceous material (C) include carbon black, graphene, graphite (artificial graphite, expanded graphite, natural graphite, etc.), coke, carbon nanotube, carbon nanohorn, fullerene, carbon fiber and the like. These carbonaceous materials can be used alone or in combination of two or more. Of these, carbon black, graphite, carbon nanotubes, carbon nanohorns, fullerenes and the like are preferable because they can improve mechanical properties without deteriorating rubber properties, and carbon black is particularly preferable in consideration of versatility.

Examples of carbon black include acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, coated carbon black, and graft carbon black. These carbon blacks can be used alone or in combination of two or more.

The average particle size of carbon black can be selected from the range of about 5 to 200 nm, and is, for example, about 10 to 150 nm, preferably 15 to 100 nm, more preferably about 20 to 80 nm (particularly about 30 to 50 nm). If the average particle size of carbon black is too small, uniform dispersion may be difficult, and if it is too large, the mechanical properties of the vulcanized rubber composition may deteriorate.

The ratio of the carbonaceous material (C) can be selected from the range of about 3 to 300 parts by mass with respect to 100 parts by mass of the rubber component (A), for example, 5 to 200 parts by mass, preferably 10 to 150 parts by mass, and further preferably Is about 30 to 100 parts by mass (particularly 50 to 80 parts by mass). If the proportion of the carbonaceous material (C) is too small, the effect of improving the mechanical properties of the rubber composition may be reduced, while if it is too large, the elongation and strength of the vulcanized rubber composition may be reduced. There is a risk.

[Softener (D)]
In order to improve the dispersibility of the carbonaceous material (C) in the composition and the mechanical properties of the composition, the rubber composition of the present invention comprises a rubber component (A), a fluorene compound (B) and a carbonaceous material ( In addition to C), a softening agent (D) may be further included.

The softening agent (D) includes oils and the like as a softening agent that is compatible with the rubber component (A) and can reduce the viscosity of the unvulcanized rubber composition. Examples of the oils include paraffin oil, naphthene oil, process oil and the like. These softening agents can be used alone or in combination of two or more.

In the present invention, even when these softening agents are blended in order to improve moldability, the fluorene compound (B) is contained, so that the softening agent (D) reduces the mechanical properties of the vulcanized rubber composition. Can be suppressed.

The proportion of the softening agent (D) can be appropriately selected according to the type of the rubber component (A), and can be selected from the range of about 0.1 to 500 parts by mass with respect to 100 parts by mass of the rubber component (A), for example, 0. 0.5 to 400 parts by mass (for example, 1 to 300 parts by mass), preferably 1 to 200 parts by mass, and more preferably 3 to 100 parts by mass. When the rubber component (A) is a diene rubber, the proportion of the softening agent (D) is, for example, 1 to 50 parts by mass, preferably 2 to 30 parts by mass, and further 100 parts by mass of the rubber component (A). It may be preferably about 3 to 10 parts by mass (particularly 4 to 8 parts by mass). If the proportion of the softening agent (D) is too small, the effect of improving the dispersibility of the carbonaceous material (C) may decrease, and if it is too large, the mechanical properties of the vulcanized rubber composition may deteriorate. is there.

[Plasticizer (E)]
The rubber composition of the present invention may further contain a plasticizer (E) in addition to the rubber component (A), the fluorene compound (B) and the carbonaceous material (C) in order to improve moldability and the like. Good. Examples of the plasticizer (E) include stearic acid, stearic acid metal salt, wax, paraffin, and fatty acid amide. These plasticizers can be used alone or in combination of two or more. Of these, higher fatty acids such as stearic acid are preferred. The proportion of the plasticizer (E) is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, and more preferably 1 to 3 parts by mass with respect to 100 parts by mass of the rubber component (A). is there. If the proportion of the plasticizer (E) is too small, the effect of improving the moldability may decrease, and conversely, if it is too large, the mechanical properties of the vulcanized rubber composition may deteriorate.

[Vulcanizing agent (F)]
The rubber composition of the present invention usually contains a vulcanizing agent (F). As the vulcanizing agent (F), a commonly used vulcanizing agent can be used depending on the type of rubber. The vulcanizing agent (F) includes a sulfur-based vulcanizing agent and an organic peroxide.

Examples of the sulfur-based vulcanizing agent include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, surface-treated sulfur, sulfur chloride (sulfur monochloride, sulfur dichloride, etc.), morpholine disulfide, alkylphenol disulfide. And so on.

Examples of organic peroxides include diacyl peroxides such as dilauroyl peroxide, dibenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide. Oxide, 1,1-di-butylperoxy-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, 1,3-bis(t- Dialkyl peroxides such as butylperoxy-isopropyl)benzene; hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide and diisopropylbenzene hydroperoxide; n-butyl-4,4-di-t-butylperoxide Examples include peroxyesters such as oxyvalerate and 2,5-dimethylhexane-2,5-di(peroxylbenzoate).

These vulcanizing agents can be used alone or in combination of two or more kinds. Among these, dialkyl peroxides such as sulfur and dicumyl peroxide are generally used.

The ratio of the vulcanizing agent (F) can be selected from the range of about 0.1 to 30 parts by mass with respect to 100 parts by mass of rubber, and in the case of a sulfur-based vulcanizing agent, for example, 0.1 to 10 parts by mass, preferably Is about 0.5 to 8 parts by mass, more preferably about 0.6 to 5 parts by mass (particularly 1 to 3 parts by mass), and in the case of an organic peroxide, for example, 1 to 25 parts by mass, preferably 3 to 20 parts by mass. Parts by mass, more preferably about 5 to 15 parts by mass.

[Vulcanization aid (G)]
The rubber composition of the present invention may further contain a vulcanization aid (G) in order to accelerate vulcanization. Examples of the vulcanization aid (or co-crosslinking agent) (G) include organic vulcanization accelerators [eg, N-cyclohexyl-2-benzothiazylsulfenamide (CBS), Nt-butyl-2. -Sulfenamide-based accelerators such as benzothiazyl sulfenamide (TBBS); thiuram-based accelerators such as tetramethylthiuram monosulfide (TMTM) and tetramethylthiuram disulfide (TMTD); 2-mercaptobenzothiazole (MBT) , Zinc salt of MBT, thiazole type accelerator such as dibenzothiazyl disulfide (MBTS); thiourea type accelerator such as trimethylthiourea (TMU) and diethylthiourea (EDE); diphenylguanidine (DPG), dioltotolylguanidine ( Guanidine-based accelerators such as DOTG); dithiocarbamic acid-based accelerators such as sodium dimethyldithiocarbamate; xanthate-based accelerators such as zinc isopropylxanthate; aldehyde-amine-based or aldehyde-ammonia-based accelerators such as hexanemethylenetetramine Etc.], polyfunctional (iso)cyanurate [eg, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), etc.], polydiene (eg, 1,2-polybutadiene etc.), metal salt of unsaturated carboxylic acid [ For example, polyvalent metal salt of (meth)acrylic acid such as zinc (meth)acrylate, polyfunctional (meth)acrylate [eg, alkanediol di(meth)acrylate such as ethylene glycol di(meth)acrylate, pentaerythritol tetra Alkane polyol poly(meth)acrylate such as (meth)acrylate], aromatic maleimide (arene bismaleimide such as N,N′-m-phenylene dimaleimide), inorganic auxiliary [zinc oxide (zinc white), oxidation Magnesium, etc.] and the like.

These vulcanization aids may be used alone or in combination of two or more. Of these, sulfenamide accelerators such as CBS, thiuram accelerators such as TMTD, and inorganic auxiliaries such as zinc oxide are widely used.

The proportion of the vulcanization aid (G) may be, for example, 1 to 30 parts by mass, preferably 3 to 25 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the rubber. The ratio of the organic vulcanization accelerator is, for example, 0.5 to 10 parts by mass, preferably 1 to 8 parts by mass, and more preferably about 1.5 to 5 parts by mass with respect to 100 parts by mass of rubber. Good. The proportion of the inorganic auxiliary agent (particularly zinc white) may be, for example, 2 to 20 parts by mass, preferably 3 to 15 parts by mass, and more preferably 4 to 10 parts by mass with respect to 100 parts by mass of the rubber. ..

[Other additives (H)]
The rubber composition of the present invention may contain a conventional additive to be added to the vulcanized rubber, depending on the type of the rubber component (A). Examples of conventional additives include resin components (thermoplastic resins, thermosetting resins, etc.), reinforcing agents (silica, titanium oxide, calcium carbonate, and other granular reinforcing agents; fibers such as cellulose fibers, aramid fibers, and glass fibers). Reinforcing agent), solvent, vulcanization retarder, dispersant, aging or antioxidant (aromatic amine-based, benzimidazole-based antioxidant, etc.), colorant (for example, dye/pigment, etc.), tackifier, Coupling agent (silane coupling agent, etc.), stabilizer (UV absorber, light resistance stabilizer, heat stabilizer, etc.), release agent, lubricant, flame retardant (phosphorus flame retardant, halogen flame retardant, inorganic type Flame retardant, etc.), vibration damping agent, flame retardant aid, antistatic agent, conductive agent, flow control agent, leveling agent, defoaming agent, surface modifier, stress reducing agent, nucleating agent, crystallization accelerator. , Antibacterial agents, preservatives and the like.

These other additives may be used alone or in combination of two or more. The ratio of the other additives is, for example, 0.1 to 50 parts by mass, preferably 0.5 to 30 parts by mass, and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component (A). May be.

[Method for producing rubber composition]
The rubber composition of the present invention is obtained through a kneading step of kneading the rubber component (A), the fluorene compound (B) and the carbonaceous material (C). Further, in the present invention, a vulcanized rubber composition is obtained through a vulcanization step of vulcanizing the kneaded composition obtained in the kneading step to obtain a vulcanized rubber composition.

In the kneading step, the kneading method of the composition containing the rubber component (A), the fluorene compound (B) and the carbonaceous material (C) may be, for example, a mixing roller, a kneader, a Banbury mixer, an extruder (uniaxial or biaxial extrusion). Machine etc.) etc. can be used. Of these, a kneader such as a pressure kneader is preferable.

The kneading may be performed without heating or with heating. When heating, the kneading temperature is, for example, about 30 to 200° C., preferably 50 to 180° C., and more preferably 100 to 170° C. (particularly 120 to 160° C.).

In the vulcanization step, normally, the unvulcanized rubber composition obtained in the kneading step is vulcanized in a state of being molded into a predetermined shape. In the vulcanization step, the vulcanization temperature can be selected according to the type of the rubber component (A), and is, for example, 100 to 250°C, preferably 150 to 200°C, more preferably 160 to 190°C.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The raw materials used and the evaluation method are as follows.

(Raw materials used)
Fluorene compound: 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, "BPEF" manufactured by Osaka Gas Chemicals Co., Ltd.
SBR: "JSR 1502" manufactured by JSR Corporation
CB N234: "Seast 7HM" manufactured by Tokai Carbon Co., Ltd.
Process oil: "Vivatec 500 (TDAE)" manufactured by H&R Co., Ltd.
Zinhua: "Zinc Hua No. 1" manufactured by Mitsui Mining & Smelting Co., Ltd.
Stearic acid: "Bead stearic acid camellia" manufactured by NOF CORPORATION
Sulfur: "Powdered Sulfur" made by Tsurumi Chemical Co., Ltd.
Accelerator CBS: "NOXCELLER CZ-G" manufactured by Ouchi Shinko Chemical Co., Ltd.

(Tensile test)
Tensile strength and elongation were measured according to JIS K6251.

(Durometer hardness)
The durometer hardness was measured according to JIS K6253 type A.

(density)
The density was measured according to JIS K6268.

(Carbon dispersibility)
The carbon dispersibility was evaluated using a filler dispersion meter (“Dispersion Checker DCF50A” manufactured by M&K Co., Ltd.). It takes a value of 0 to 100, and the higher the value, the higher the dispersibility.

Comparative Example 1 and Examples 1-2
The components in the proportions shown in Table 1 were kneaded at a temperature of 150° C. using a pressure kneader (manufactured by Moriyama Co., Ltd., capacity: 10 liters) to prepare an unvulcanized rubber composition. The obtained composition was press-vulcanized at a vulcanization temperature of 180° C. to obtain a vulcanized rubber composition.

Table 2 shows the evaluation results of the vulcanized rubber compositions obtained in Comparative Example 1 and Examples 1 and 2.

As is clear from the results in Table 2, the vulcanized rubber compositions of the examples have improved carbon black dispersibility, tensile strength and elongation as compared to the vulcanized rubber composition of Comparative Example 1.

The rubber composition of the present invention is used for various industrial members (conveyor belts, rubber cover rolls, gaskets, printing rolls, oil seals, packings, hoses such as oil resistant hoses, etc.), building members (window frame rubber, damping materials, It can be used for carpet bagging materials), transportation equipment materials (automobile materials, tires, power transmission belts, etc.), and electric/electronic equipment materials (electric wire coatings, etc.).

Claims (10)

A rubber composition comprising a rubber component (A), a fluorene compound (B) having a 9,9-bis(aryl)fluorene skeleton, and a carbonaceous material (C). The rubber composition according to claim 1, wherein the fluorene compound (B) is a compound represented by the following formula (1).

(In the formula, ring Z is an arene ring, R ¹ and R ² are substituents, X ¹ is a heteroatom-containing functional group, k is an integer of 0 to 4, n is an integer of 1 or more, and p is an integer of 0 or more. Show) In formula (1), ^{X 1} is a group _{- [(OA) m1 -OH]} ( in the formula, A is an alkylene group, m1 represents an integer of 0 or more) according to claim 1 or 2 rubber composition wherein the .. The rubber composition according to claim 1, wherein the rubber component (A) is a diene rubber. The rubber composition according to claim 4, wherein the diene rubber has an aromatic skeleton. The rubber composition according to claim 1, wherein the carbonaceous material (C) is carbon black. The ratio of the fluorene compound (B) is 1 to 30 parts by mass and the ratio of the carbonaceous material (C) is 10 to 300 parts by mass with respect to 100 parts by mass of the rubber component (A). The rubber composition according to any one of claims. The rubber composition according to any one of claims 1 to 7, which is a vulcanized vulcanized rubber composition. The method for producing a rubber composition according to claim 1, further comprising a kneading step of kneading the rubber component (A), the fluorene compound (B) and the carbonaceous material (C). The production method according to claim 9, further comprising a vulcanization step of vulcanizing the kneaded composition obtained in the kneading step to obtain a vulcanized rubber composition.