Modified vinylaromatic compolymer and methdo of producing the same, and modified conjugated diene based copolymer, resin composition, resin crosslinked product and structural member obtained from the same

Abstract

The present invention provides a reactive and soluble modified vinyl aromatic copolymer that can be used to manufacture copolymer rubber, and a copolymer rubber material obtained from the copolymer that has processability, strength and homogeneity. The modified vinyl aromatic copolymer of the present invention is characterized by containing structural units (a) derived from divinyl aromatic compounds, structural units (b) derived from monovinyl aromatic compounds, and structural units (c) derived from conjugated diene compounds, wherein 95 mol% or more of the structural unit (a) is a crosslinked structural unit (a1) represented by the following formula (1), the modified vinyl aromatic copolymer is modified by at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups and hydroxyl groups, and 30 mol% or more of the aforementioned functional groups are bonded to the structural unit (c) derived from the conjugated diene compound, and its number average molecular weight Mn is 500 to 30,000.

Description

Technical Field

[0001] This invention relates to modified vinyl aromatic copolymers with branched structures and their manufacturing methods, as well as modified conjugated diene copolymers with excellent processability, tensile strength and wear resistance, resin compositions obtained from the copolymers, resin crosslinks formed by crosslinking the copolymers, and structural components. Prior Technology

[0002] Compounds containing multiple vinyl groups within their molecules readily undergo intermolecular cross-linking reactions through polymerization. Utilizing this property, by adding such compounds to a polymerization system to copolymerize them, cross-linked polymers can be formed, rendering the polymer insoluble or imparting functionality. For example, divinylbenzene, a compound with multiple vinyl groups within its molecule, can be used as an ion exchange resin by adding a small amount to a styrene polymer and copolymerizing it to introduce functional groups such as sulfonic acid groups. Furthermore, it can be used as a crosslinking agent for styrene-based resins such as synthetic rubber, ABS resin, MBS resin, and unsaturated polyester resin, or as a modifier for polyethylene. Furthermore, in another example, by reacting a branched polyfunctional vinyl aromatic copolymer with a thermoplastic resin, it is also expected to impart functionality to the thermoplastic resin. For example, conjugated diene rubbers such as SBR (styrene-butadiene rubber), BR (butadiene rubber), IR (isoprene rubber), and styrene-isoprene rubber have excellent abrasion resistance, elasticity, and water resistance, and are used in various applications such as molding materials and resin modifiers.

[0003] One of the main applications of this conjugated diene rubber is in automobile tires. The required properties for tires include: mechanical strength, abrasion resistance, and wet grip (hereinafter collectively referred to as strength, etc.). Furthermore, in recent years, there has been active development of tires with excellent energy efficiency, i.e., low fuel consumption (the so-called "ecotire"). These eco-friendly tires, in addition to strength, also require low rolling resistance.

[0004] It is known that fillers such as carbon black or silica are added to conjugated diene rubber (reinforcing fillers) to ensure tire strength, but end-modified solution polymerized SBR (end-modified S-SBR) has attracted much attention as a material to further improve tire strength and impart excellent rolling resistance. End-modified S-SBR has functional groups at the ends of the SBR molecules, which interact with the filler. Through this interaction, the dispersibility of the filler in the SBR is improved, and the molecular ends of the SBR are constrained, reducing mobility. The result is a reduction in tire hysteresis loss (internal friction) and rolling resistance. Currently, this property is being utilized to develop environmentally friendly tires that combine strength and low rolling resistance.

[0005] In such rubber compositions, various studies are being conducted on methods for modifying butadiene-based polymers used as raw rubber by introducing predetermined functional groups into them, with the aim of improving the affinity between the polymer and the filler. For example, in Patent Document 1, an organolithium compound is used as an initiator in a nonpolar solvent to synthesize a block copolymer composed of α-methylstyrene and butadiene blocks by active anionic polymerization. Furthermore, by reacting a multifunctional coupling agent according to requirements, an S-SBR with both high-temperature properties and rubber properties is obtained. Patent document 2 discloses a star-block interpolymer having random copolymer blocks of conjugated diene and monovinyl aromatic monomer, polyconjugated diene blocks, and functional groups derived from multifunctional lithium-based initiators. It also discloses that it can be widely used as a rubber for making tire treads with excellent properties such as reduced rolling resistance and improved traction characteristics. Patent documents 1 and 2 suggest that introducing branched structures into the rubber composition can ensure the processability of the rubber. However, they do not specifically consider the interaction with fillers used to ensure strength, and therefore the contribution to strength is insufficient. Patent document 3 discloses a rubber composition formed by incorporating a predetermined amount of carbon black into a mixed rubber comprising multiple diene rubbers. The composition incorporates a low-molecular-weight polymer containing functional groups at the ends of its molecular chains that interact with the carbon black, and is composed of a polymer structure similar to that of the diene rubber components. This rubber composition allows for control of the distribution of carbon black among the diene rubber components by incorporating a low-molecular-weight compound that interacts with the carbon black into the rubber. Therefore, the advantages of each rubber component can be effectively utilized, for example, achieving rubber properties that are opposite in nature, such as rolling and wetting properties. However, in this technology, because of the incorporation of low-molecular-weight compounds into the rubber, the contribution to strength is not sufficient. Patent Document 4 discloses a rubber composition containing cross-linked rubber particles comprising conjugated diene units, aromatic vinyl units, and units having at least two polymerizable unsaturated groups, as well as a conjugated diene / aromatic vinyl copolymer rubber comprising conjugated diene units having a specific bonding structure. It also discloses that the cross-linked rubber particles may contain monomer units having carboxylic acid groups, amino groups, hydroxyl groups, epoxy groups, and alkoxysilicone groups. The technology disclosed in Patent Document 4 involves making the cross-linked rubber particles, comprising three-dimensionally cross-linked conjugated diene units, aromatic vinyl units, and units having at least two polymerizable unsaturated groups, contain at least one functional group selected from carboxylic acid groups, amino groups, hydroxyl groups, epoxy groups, and alkoxysilicone groups. By using polymerizable unsaturated monomers that can copolymerize with the monomers of the cross-linked rubber particles, the monomers are introduced into the cross-linked rubber particles, resulting in appropriate interactions with inorganic fillers (fillers) such as silica. Therefore, the dispersibility and processability of the inorganic fillers are excellent. However, according to the technology disclosed in the patent publication, introducing at least one of the functional groups among the carboxylic acid group, amino group, hydroxyl group, epoxy group and alkoxysilyl group of the three-dimensional cross-linked rubber particles will enter the interior of the insoluble network structure of the cross-linked rubber particles, which may not help the dispersibility of the inorganic filler outside the cross-linked rubber particles, and the effect of functional group introduction is not sufficient. Patent Document 5 discloses a conjugated diene rubber formed from an interpenetrating network structure polymer. This interpenetrating network structure polymer is composed of a crosslinked polymer having structural units derived from vinyl unsaturated compounds with a glass transition temperature of 10°C or higher from homopolymers and structural units derived from crosslinking compounds, and a non-crosslinked polymer having structural units derived from conjugated diene compounds. The embodiments of this patent disclose a conjugated diene rubber in which a crosslinked polymer composed of styrene and divinylbenzene is polymerized. After deactivating a portion of the active species, butadiene and n-butyllithium as a polymerization initiator are added to continue polymerization. After polymerization, modifiers such as N,N-bis(triethylsilyl)aminopropylmethyldimethoxysilane are added for modification. However, the patent publication discloses that the molecular ends of non-crosslinked polymers can also be modified by using a modifier formed from a silane compound containing functional groups such as amine, phosphine, or thiol groups. It does not show that the modifier modifies the crosslinked polymer itself composed of styrene and divinylbenzene. Furthermore, the crosslinked polymer composed of styrene and divinylbenzene disclosed in the patent publication, even though it is a three-dimensionally crosslinked polymer insoluble in solvents and is a non-crosslinked polymer with structural units derived from conjugated diene compounds, exhibits an interpenetrating network structure, but due to its structurally brittle microgels, the improvement in mechanical strength is insufficient. Patent document 6 discloses a cross-linked polymer particle characterized by a polysiloxane surface and an average particle size of 0.01 to 10 μm. In an embodiment of this patent publication, divinylbenzene and styrene are subjected to suspension polymerization in the presence of a free radical polymerization initiator. After obtaining polymer particles, methyltriethoxysilane is reacted at pH 8.0, and the polysiloxane-modified cross-linked polymer particles are recovered. It is further disclosed that incorporating the obtained polysiloxane-modified cross-linked polymer particles into polypropylene resin can improve the anti-caking properties of the membrane. Furthermore, it is disclosed that the polysiloxane-modified cross-linked polymer particles of this patent publication can be used as a resin modifier, a flow improver for toner, an anti-caking agent for resin membranes, a slip agent for films, a spacer, a standard particle, an antigen-antibody reaction test particle, a transport stabilizer for thermal paper, a cosmetic additive, a rheology control agent, and a low-shrinkage agent. However, the polysiloxane-modified crosslinked polymer particles disclosed in the patent publication are crosslinked polymer particles that are insoluble in solvents. They are hard and brittle crosslinked polymer particles, so if they are used to modify conjugated diene copolymers synthesized by anionic polymerization, they cannot improve the strength. Patent Document 7 discloses the formation of the "ω,ω-carboanionic" active polymer molecule of the present invention by reacting a vinylene polymerization initiator with a monomer, and obtaining a modified polymer molecule by reacting at least one active polymer molecule with at least one equivalent of a chain-end modifier. It then discloses the formation of branched modified polymer molecules by reacting a coupling agent such as tin tetrachloride with the end positions of the carboanionic polymer chains. Furthermore, it discloses the formation of branched modified polymer molecules by adding monomers capable of reacting two or more growth polymer chains, such as divinylbenzene, to the polymerization mixture at any time during polymerization. However, according to the technology in this patent publication, if divinylbenzene is subsequently added as a coupling agent, microgels are formed, resulting in insufficient strength improvement. Furthermore, this patent publication does not suggest the use of low-molecular-weight, solvent-soluble modified vinyl aromatic copolymers with functional groups and branched structures as coupling agents for conjugated diene polymers. Patent Document 8 discloses a crosslinked polymer, which is formed by swelling an aminomethylated polystyrene crosslinked with 1% divinylbenzene in dichloromethane, followed by reaction with toluene 2,4-diisocyanate (TDI) to contain silylated ferrocene diphosphine ligands. However, the crosslinked polymer disclosed in this patent publication is swelled in dichloromethane, which suggests that the crosslinked polymer disclosed in this patent publication is not solvent-soluble and does not consider solvent-soluble branched polymers. Furthermore, although the crosslinked polymer disclosed in this patent publication can be used as a catalyst for enantioselective hydrogenation, it does not suggest the possibility that it can help improve the properties of conjugated diene polymers. Patent document 9 discloses a resin composition modified by incorporating antioxidants, silane coupling agents, and free radical initiators into a crosslinked copolymer (a copolymer containing ethylene-styrene-divinylbenzene copolymer chains and polystyrene chains obtained by anionic polymerization in the presence of styrene monomers obtained by coordination polymerization, followed by compounding. However, in the crosslinked copolymer used in the examples of this patent publication, the divinylbenzene content is significantly lower than 0.5 mol%, and it does not mention whether the subsequently added silane coupling agent modifies the ends of the crosslinked copolymer, nor does it suggest the possibility that coupling the conjugated diene-based active polymer can improve the properties of the conjugated diene polymer.

[0006] Therefore, in view of the above issues, the applicant disclosed that a copolymer rubber can be provided, which combines processability, strength and homogeneity by using a specific polyfunctional vinyl aromatic copolymer that has the function of interacting with branched structures and fillers as the constituent unit of the conjugated diene rubber (Patent Document 10). Furthermore, patent documents 11 to 14 propose a multifunctional vinyl aromatic copolymer, wherein the copolymer must have an indane structural unit or a structural unit derived from a cycloalkene compound and a structural unit derived from styrene. This invention proposes a material that helps modify resins by means of a different method than those disclosed in Patent Documents 10 to 14. This material is particularly useful for rubber components such as tires, and helps to improve properties such as strength and wear resistance. [Previous Technical Documents] [Patent Literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2003-73434 [Patent Document 2] Japanese Patent Publication No. 2004-517202 [Patent Document 3] Japanese Patent Application Publication No. 2005-213381 [Patent Document 4] International Publication No. 2002 / 000779 [Patent Document 5] Japanese Patent Application Publication No. 2013-155268 [Patent Document 6] Japanese Patent Application Publication No. 7-207029 [Patent Document 7] Japanese Patent Publication No. 2016-530361 [Patent Document 8] Japanese Patent Application Publication No. 8-259584 [Patent Document 9] Japanese Patent Application Publication No. 2012-92197 [Patent Document 10] International Publication No. 2018 / 084128 [Patent Document 11] Japanese Patent Application Publication No. 2004-123873 [Patent Document 12] Japanese Patent Application Publication No. 2018-39995 [Patent Document 13] International Publication No. 2018 / 181842 [Patent Document 14] International Publication No. 2020 / 67336 Summary of the Invention

[0008] The purpose of this invention is to solve this problem by providing a modified vinyl aromatic copolymer, which is reactive and soluble and can be used to manufacture a modified conjugated diene copolymer with a branched structure, without the formation of even a small amount of microgels, and provides a resin composition with a branched structure that has processability, strength and homogeneity, a resin crosslink formed by crosslinking it, and a structural component.

[0009] Through repeated and detailed research, the inventors of this case discovered that a copolymer obtained by modifying the active ends of a branched vinyl aromatic copolymer containing structural units (a) derived from specific divinyl aromatic compounds, structural units (b) derived from monovinyl aromatic compounds, and structural units (c) derived from conjugated diene compounds with amino groups, alkoxysilyl groups, or hydroxyl groups can solve the above-mentioned problems, thereby completing the present invention.

[0010] This invention relates to a modified vinyl aromatic copolymer, characterized by containing structural units (a) derived from divinyl aromatic compounds, structural units (b) derived from monovinyl aromatic compounds, and structural units (c) derived from conjugated diene compounds, wherein 95 mol% or more of structural unit (a) is a crosslinked structural unit (a1) represented by the following formula (1): In the formula, R1 represents an aromatic hydrocarbon group with 6 to 30 carbon atoms; It is modified by at least one functional group selected from the group consisting of amino, alkoxysilyl and hydroxyl groups, with an average number of functional groups of 2.0 or more per molecule, and more than 30 moles of the aforementioned functional groups are bonded to structural units (c) derived from conjugated diene compounds for modification, and the number average molecular weight Mn is 500 to 30,000.

[0011] The modified vinyl aromatic copolymer described above may contain: 0.5 mol% to 45.0 mol% of structural units derived from divinyl aromatic compounds (a), 0.5 mol% to 99.0 mol% of structural units derived from monovinyl aromatic compounds (b), and 0.5 mol% to 99.0 mol% of structural units derived from conjugated diene compounds (c), and the molecular weight distribution (Mw / Mn), expressed as the ratio of weight average molecular weight Mw to number average molecular weight Mn, may be 10.0 or less. Furthermore, the average number of the aforementioned functional groups per molecule may be in the range of 2 to 20. Examples of the aforementioned monovinyl aromatic compounds include: styrene, vinylnaphthalene, vinylbiphenyl, m-methylstyrene, p-methylstyrene, o-, p-dimethylstyrene, m-ethylvinylbenzene, indene, or p-ethylvinylbenzene.

[0012] Furthermore, the present invention relates to a method for manufacturing the aforementioned modified vinyl aromatic copolymer, comprising: a polymerization step, using an alkali metal compound or an alkaline earth metal compound as an anionic polymerization initiator, copolymerizing a divinyl aromatic compound and a monovinyl aromatic compound, or a divinyl aromatic compound and a monovinyl aromatic compound and monomers capable of anionic copolymerization with such compounds, to obtain a vinyl aromatic copolymer having a branched structure and active ends; and an end modification step, reacting a compound having at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups, and hydroxyl groups, or such precursor compounds, at the active ends of the vinyl aromatic copolymer to form functional groups.

[0013] Furthermore, the present invention is a modified conjugated diene copolymer, which is obtained by reacting the above-mentioned modified vinyl aromatic copolymer with a polymer of a conjugated diene compound or a copolymer of a conjugated diene compound and an aromatic vinyl compound.

[0014] The aforementioned modified conjugated diene copolymer may contain 0.001 to 6% by weight of structural units derived from modified vinyl aromatic copolymers (A1), 29 to 99.999% by weight of structural units derived from conjugated diene compounds (B1), and 0 to 70% by weight of structural units derived from aromatic vinyl compounds (C1). Furthermore, in the differential molecular weight distribution curve obtained by gel permeation chromatography (GPC), when the total area is set to 100%, the area of ​​the region with a number average molecular weight (Mn) that is more than three times (3 Mp or more) the peak value on the lowest molecular weight side may be more than 10%.

[0015] Furthermore, the present invention is a resin composition, wherein, relative to 100 parts by weight of the above-mentioned modified conjugated diene copolymer, it contains 0.5 to 200 parts by weight of at least one reinforcing filler selected from the group consisting of silicon dioxide inorganic fillers, metal oxides, metal hydroxides and carbon black.

[0016] The resin composition may further contain a crosslinking agent. Furthermore, the present invention is a resin crosslinker, characterized by being formed by crosslinking a resin composition further containing a crosslinking agent. Furthermore, the present invention is a structural component characterized by comprising the resin crosslinker.

[0017] The modified vinyl aromatic copolymer of the present invention can be used as a raw material for modified conjugated diene copolymers. Furthermore, the modified conjugated diene copolymer contains fillers, and the cross-linked resin composition formed by its cross-linking exhibits excellent filler dispersibility and superior mechanical strength and abrasion resistance. Therefore, it can be used as an elastomer material for tires (especially tire treads), shock-absorbing rubber, rubber hoses, rubber rollers, footwear materials, etc. It can also be applied to molding materials and as a resin modifier. In the electrical / electronics industry, aerospace industry, and construction industry, it can be provided as a dielectric material, insulating material, heat-resistant material, structural material, adhesive, filler, coating, coating agent, sealant, ink, dispersant, etc., suitable for low-dielectric substrates. Furthermore, films and sheets coated with curable resin compositions containing the modified vinyl aromatic copolymers of this invention are suitable for use in plastic optical components, touch panels, flat panel displays, thin-film liquid crystal elements, etc. The modified vinyl aromatic copolymers of this invention can be used as modifiers to modify the heat resistance, dielectric properties, adhesion / sealing properties, and optical properties of thermoplastic or curable resin compositions used as the main materials for films, sheets, and prepregs. Additionally, curable resin compositions containing the multifunctional vinyl aromatic copolymers of this invention as the main material can also be processed into films, sheets, and prepregs for use. Moreover, curable resin compositions containing the modified vinyl aromatic copolymers of this invention can also be used as various optical components, primarily optical waveguides and optical lenses. Simple Explanation of the Diagram

[0018] Figure 1 shows a GPC graph displaying the peak molecular weight (Mp), the molecular weight twice that of Mp (2Mp), and the molecular weight three times that of Mp (3Mp). Implementation

[0019] The modified vinyl aromatic copolymer of the present invention (hereinafter also referred to as modified copolymer or copolymer) is a copolymer containing structural units (a) derived from divinyl aromatic compounds, structural units (b) derived from monovinyl aromatic compounds and structural units (c) derived from conjugated diene compounds, wherein 95 mol% or more of the structural unit (a) is a crosslinked structural unit (a1) represented by the above formula (1).

[0020] The structural unit (a) derived from divinyl aromatic compounds contained in the modified vinyl aromatic copolymer of the present invention plays an important role as a crosslinking component that branches the copolymer and forms a multifunctional crosslinking component. If a polymer of conjugated diene compounds is modified using a multifunctional modified vinyl aromatic copolymer, a high molecular weight multibranched component is generated, and abrasion resistance can be improved. Examples of divinyl aromatic compounds include divinylbenzene (including its isomers), divinylnaphthalene (including its isomers), and divinylbiphenyl (including its isomers), but these are not limited to these. Furthermore, these compounds can be used alone or in combination of two or more. From a processability point of view, divinylbenzene (intermediate, para, or a mixture of their isomers) is more preferred.

[0021] On the other hand, the structural units (b) derived from monovinyl aromatic compounds contained in the modified vinyl aromatic copolymers of the present invention improve the solvent solubility, compatibility, and processability of the copolymers. Examples of monovinyl aromatic compounds include: vinyl aromatic compounds such as styrene, vinylnaphthalene, vinyl biphenyl, and α-methylstyrene; nucleoalkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o-, p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene; cyclic vinyl aromatic compounds such as indene, acenaphthene, benzothiophene, and coumarone, but not limited to these. In order to prevent the copolymer from gelling and improve its solubility, compatibility, and processability in solvents, from the viewpoint of cost and availability, it is particularly preferable to use styrene, ethylvinylbenzene (including various isomers), ethylvinyl biphenyl (including various isomers), ethylvinylnaphthalene (including various isomers), and indene. From a compatibility and cost perspective, styrene, ethyl vinylbenzene (intermediate, para, or mixtures of isomers thereof), and indene are preferred.

[0022] The structural unit (c) derived from a conjugated diene compound contained in the modified vinyl aromatic copolymer of the present invention has the following functions: 1) improving the introduction efficiency of the modified group of the modified vinyl aromatic copolymer; 2) improving the reactivity of the terminal modified group of the modified vinyl aromatic copolymer when the modified vinyl aromatic copolymer reacts with a polymer of a conjugated diene compound with an active end, or with a copolymer of a conjugated diene compound with an active end and an aromatic vinyl compound.

[0023] Regarding conjugated diene compounds, those containing 4 to 12 carbon atoms per molecule are preferred, and those containing 4 to 8 carbon atoms are more preferred. Such conjugated diene compounds are not limited to those listed below, but examples include: 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-heptadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of ease of copolymerization with aromatic vinyl compounds and ease of industrial acquisition. One of these compounds may be used alone, or two or more may be used in combination.

[0024] The modified vinyl aromatic copolymer of the present invention can be modified by a polymerization initiator or modifier having at least one functional group selected from the group consisting of amino groups (-NR), alkoxysilyl groups (Si-OR), and hydroxyl groups (-OH), wherein the amount of modifier introduced is such that the average number of functional groups per molecule is 2.0 or more. If the value of the number average molecular weight of the copolymer divided by the functional group equivalent is 2.0 or more, it can be determined that two or more functional groups have been functionalized. The amount introduced from the polymerization initiator or modifier having functional groups is such that the average number of functional groups per molecule is preferably 2.0 to 20, more preferably 2.0 to 5.0, and even more preferably 2.0 to 4.0 terminal functional groups. In the modified vinyl aromatic copolymers of the present invention, the modifier having a functional group introduced as a stopping terminal by reacting with the active terminal at the time of polymerization is preferably 30 mol% or more, more preferably 60 mol% or more, bonded to the structural unit (c) derived from the conjugated diene compound for modification. For example, in anionic living polymerization, when a diene monomer is added after the successive addition of monomers, the conversion of the active terminal into a diene monomer unit can be confirmed by the shift of the molecular weight distribution to the high molecular weight side. The modifier having the functional group is more preferably 80 mol% or more, most preferably 90 mol% or more, bonded to the structural unit (c) derived from the conjugated diene compound for modification.

[0025] The modified copolymer of the present invention can be manufactured by the manufacturing method of the present invention. The manufacturing method of the present invention includes: a polymerization step, using an alkali metal compound or an alkaline earth metal compound as an anionic polymerization initiator to copolymerize a divinyl aromatic compound and a monovinyl aromatic compound, or a divinyl aromatic compound and a monovinyl aromatic compound and monomers that can be anionicly copolymerized with such compounds, to obtain a vinyl aromatic copolymer (M) having a branched structure and active ends; and an end modification step, forming the aforementioned functional groups at the active ends of the vinyl aromatic copolymer (M).

[0026] The modified vinyl aromatic copolymer of the present invention is a copolymer containing structural units (a) derived from divinyl aromatic compounds, structural units (b) derived from monovinyl aromatic compounds, and structural units (c) derived from conjugated diene compounds. However, within the scope of not damaging the structural units (a) to (c), other monomers with anionic polymerization properties, such as trivinyl aromatic compounds, can be used to introduce structural units (e) derived from these other monomers into the copolymer.

[0027] Specific examples of the other monomers mentioned above are preferably 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, etc., but are not limited to these. These can be used alone or in combination of two or more. Other monomers can also be used in amounts less than 30 mol% of all monomers. Thus, the structural units relative to the total amount of structural units in the copolymer, derived from structural units (e) of other monomers, are in the range of less than 30 mol%. Furthermore, when synthesizing a vinyl aromatic copolymer comprising structural units (a) derived from divinyl aromatic compounds and structural units (b) derived from monovinyl aromatic compounds via cationic polymerization as a precursor, and then using it as a polymeric initiator derived from the precursor prepolymer and a polymerization initiator composed of alkali metal compounds or alkaline earth metal compounds to synthesize the modified vinyl aromatic copolymer of the present invention, specific examples of monomers introduced into the precursor prepolymer as other monomers include: isobutylene, diisobutylene, cyclobutene, cyclopentene, etc. Cyclooctene, norcamphene, dicyclopentadiene, 2-methyl-1-butene, 2-methyl-1-pentene, 1-methyl-1-cyclopentene, 2-methyl-1-hexene, 1-methyl-1-cyclohexene, 2-methyl-1-heptene, 2-methyl-1-octene, 2-methyl-1-nonene, 2-methyl-1-decene, 2-methyl-1-dodecene, 2-methyl-1-tetradecene, 2-methyl-1-hexadecene, 2-methyl-1-octadecene, 2-methyl-1-eicosene, 2-methyl-1-teicosadiene, 2-methyl-1-teicosteaene, etc., but not limited to these. These can be used alone or in combination of two or more. Other monomers can also be used in amounts less than 30 mol% of all monomers. Thus, the structural units relative to the total amount of structural units in the copolymer, the structural units (e) derived from other monomers, are in the range of less than 30 mol%.

[0028] In the above-mentioned method for manufacturing unmodified multifunctional vinyl aromatic copolymers, copolymers are manufactured by polymerizing divinyl aromatic compounds and monovinyl aromatic compounds, or monomers containing other monomers as required, in the presence of a polymerization initiator composed of alkali metal compounds or alkaline earth metal compounds.

[0029] At least a portion of the above structural unit (a) is the cross-linked structural unit (a1) represented by the above formula (1), but the molar fraction (also known as the degree of cross-linking) representing the proportion of the cross-linked structural unit (a1) derived from the divinyl aromatic compound relative to the structural unit (a) is 0.95 or more. The degree of crosslinking of the crosslinked structural unit (a1) is in the range of 0.95 or higher, but the lower limit is preferably 0.98 or higher, and more preferably 0.99 or higher.

[0030] The aforementioned degree of crosslinking is a parameter that can be arbitrarily controlled and changed. However, if the degree of crosslinking is less than 0.95, due to the large amount of highly reactive side vinyl groups remaining in the modified copolymer of the present invention, when the polymer is used to modify conjugated diene (co)polymers, due to the thermal process in subsequent steps, crosslinking reactions are easily initiated from the side vinyl groups remaining in the copolymer, resulting in a tendency to generate microgels during compounding or vulcanization.

[0031] The method for manufacturing the modified copolymer of the present invention, as described above, includes a polymerization step and an end-modification step. This describes the polymerization initiator, which is composed of alkali metal compounds or alkaline earth metal compounds, used in the polymerization step. There are no particular limitations on the alkali metal compounds used as polymerization initiators; for example, organolithium compounds are preferred. Organolithium compounds can be any of the following: low molecular weight organolithium compounds or soluble oligomeric organolithium compounds. Examples of compounds with carbon-lithium bonds, nitrogen-lithium bonds, or tin-lithium bonds include those with organic groups. Using organolithium compounds results in good initiation efficiency and high polymer activity. There are no particular limitations on the organolithium compounds used; examples include organolithium monolithium compounds, organolithium dilithium compounds, and organolithium polylithium compounds. The organic group should preferably be a hydrocarbon containing a functional group, as this provides excellent solubility in organic solvents and also results in a good initiation rate. Furthermore, by using compounds with nitrogen-lithium bonds or tin-lithium bonds, functionalized modification groups can be introduced into the initiator. There are no particular limitations regarding organoalkali metal compounds other than organolithium compounds; examples include organosoilane compounds, organopotassium compounds, organorubidium compounds, and organocesium compounds. More specifically, examples include sodium naphthalene and potassium naphthalene. Additionally, examples include alkoxides, sulfonates, carbonates, and acetylamines of lithium, sodium, and potassium. Furthermore, they can be used in combination with other organometallic compounds.

[0032] Examples of alkaline earth metal compounds used as polymerization initiators include organomagnesium compounds, organocalcanthenic compounds, and organostrontium compounds. Alkaline earth metal alkoxides, sulfonates, carbonates, and amides can also be used. These organoalkaline earth metal compounds can also be used in combination with the aforementioned alkali metal compounds or other organometallic compounds.

[0033] In this invention, a polymerization initiator having at least one functional group selected from the group consisting of amino (-NR), alkoxysilyl (-Si-OR) and hydroxyl (-OH) can be used to modify the terminal or structural unit. Here, the amino group (-NR) includes a primary amino group (-NH2), a secondary amino group (-NHR1), or a tertiary amino group (-NR1R2). The alkoxysilyl group (-Si-OR) is formed by one to three alkoxy groups bonded to silicon. Examples of alkoxy groups bonded to the alkoxysilyl group include methoxy, ethoxy, propoxy, butoxy, pentoxy, and hexoxy. Among these, from the viewpoint of ending the reaction with the polymer having an active end in a short time, methoxy and ethoxy are preferred. Therefore, regarding the alkoxysilyl group, methoxysilyl (-Si-OCH3) or ethoxysilyl (-Si-OC2H5) are preferred.

[0034] There are no particular limitations on the functionalized alkali metal compounds that can be used as polymerization initiators. Examples include lithium amide compounds obtained by lithiumning a secondary amine, or alkyllithium compounds bonded with the aforementioned functional groups. These compounds can thereby impart functional groups to the polymerization initiation terminals of conjugated diene copolymers. There are no particular limitations on the functional groups, but they are preferably inactive relative to the alkali metal. Examples include disubstituted amino groups (i.e., tertiary amines), protected monosubstituted amino groups (hereinafter also referred to as "protected monosubstituted amino groups"), and protected amino groups (hereinafter also referred to as "protected disubstituted amino groups"). Furthermore, examples of protected monosubstituted amino groups or protected amino groups include those formed by replacing one hydrogen atom of a monosubstituted amino group or two hydrogen atoms of an amino group with trialkylsilyl groups.

[0035] There are no particular limitations on the organolithium compounds used as polymerization initiators, but examples include: single organolithium compounds such as n-butyllithium, dibutyllithium, tributyllithium, n-propyllithium, isopropyllithium, and benzyllithium; and multifunctional organolithium compounds such as 1,4-dilithium butane, 1,5-dilithium pentane, 1,6-dilithium hexane, 1,10-dilithium decane, 1,1-dilithium diphenylene, dilithium polybutadiene, dilithium polyisoprene, 1,4-dilithium benzene, 1,2-dilithium-1,2-diphenylethane, 1,4-dilithium-2-ethylcyclohexane, 1,3,5-trilithium benzene, and 1,3,5-trilithium-2,4,6-triethylbenzene. Among these, single organolithium compounds such as n-butyllithium, dibutyllithium, and tributyllithium are preferred.

[0036] There are no particular limitations on polymerization initiators with functional groups; the following compounds are examples. Additionally, the types of functional groups that can be imparted to the polymer are listed in parentheses. Examples include lithium dipropylamino, lithium diisopropylamino, lithium dibutylamino, lithium tetramethyleneimine, lithium pentamethyleneimine, lithium hexamethyleneimine, lithium heptamethyleneimine, lithium 2-dimethylaminoethyl, lithium 3-dimethylaminopropyl, lithium 3-diethylaminopropyl, lithium 4-dimethylaminobutyl (all disubstituted amino groups), lithium 2-trimethylsilylethylaminoethyl, lithium 3-trimethylsilylmethylaminopropyl (all monosubstituted amino groups), lithium 2-bistrimethylsilylaminoethyl, and lithium 3-bistrimethylsilylaminopropyl (all amino groups).

[0037] Regarding polymerization initiators, various lithium-based initiators can be used to react with monomers to form oligomeric initiators. In this case, the monomer can be a monomer having at least one functional group selected from the group consisting of amino, alkoxysilyl, and hydroxyl groups. There are no particular limitations on the oligomeric initiator; however, a molecular weight of 1000 or less is preferred for ease of industrialization. When using a functionalized polymerization initiator for polymerization or copolymerization, in a next step, a compound having at least one functional group selected from the group consisting of amino, alkoxysilyl, and hydroxyl groups, or a compound forming at least one functional group selected from the group consisting of amino, alkoxysilyl, and hydroxyl groups, can be introduced into the active end of the vinyl aromatic copolymer.

[0038] There are no particular limitations regarding multifunctional initiators; specifically, there are organodilithium compounds and organopolylithium compounds. The organic group is not particularly limited, but it is preferably a hydrocarbon. This provides the advantage of excellent solubility in organic solvents and also a good initiation rate.

[0039] There are no particular limitations on the preparation methods of multifunctional initiators. For example, the method of reacting lithium metal dispersions with polyhalogenated hydrocarbon compounds can be listed.

[0040] Polar compounds can also be added during the polymerization steps described above. By adding polar compounds to participate in the initiation and growth reactions, they can also be effective in controlling the molecular weight / molecular weight distribution and promoting the polymerization reaction. Examples of polar compounds include: tetrahydrofuran, diethyl ether, and diethyl ether. Ethers such as alkanes, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis(2-oxolanyl))propane; tertiary amines such as tetramethylethylenediamine, dipiperidinyl ethane, trimethylamine, triethylamine, pyridine, and quinuclidine; alkali metal alkoxides such as potassium terpentoxide, potassium terbutoxide, sodium terbutoxide, and sodium pentanoxide; and phosphine compounds such as triphenylphosphine. These polar compounds can be used alone or in combination of two or more. There is no particular limitation on the amount of polar compound used, and it can be selected according to the purpose, etc. Generally, 0.01 to 100 mol is preferred relative to 1 mol of polymerization initiator or multifunctional initiator. Such polar compounds, as regulators of the initiation and growth reactions of modified vinyl aromatic copolymers (A), can be used in appropriate amounts according to the expected molecular weight and molecular weight distribution. Most polar compounds have an effective randomizing effect in the copolymerization of divinyl aromatic compounds and monovinyl aromatic compounds, and can be used as regulators of the distribution of aromatic vinyl compounds or the amount of styrene blocks.

[0041] The copolymerization of monomers comprising divinyl aromatic compounds and monovinyl aromatic compounds is preferably carried out by solution polymerization in an inert solvent. There are no particular limitations on the polymerization solvent; hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons can be used. Specific examples include: hydrocarbon solvents composed of aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, and decahydronaphthalene; aromatic hydrocarbons such as benzene, toluene, and xylene; and mixtures thereof. Preferably, organometallic compounds are used beforehand to treat the monomers and polymerization solvents separately, or to treat a mixture thereof. This allows for the treatment of monomers such as divinyl aromatic compounds and monovinyl aromatic compounds, or allenes or acetylenes contained in the polymerization solvent. The result is a polymer with a high concentration of active terminals, achieving a high modification rate.

[0042] The polymerization temperature during copolymerization is not particularly limited as long as it is a temperature suitable for living anionic polymerization. From a production point of view, it is preferably above 0°C. From the viewpoint of ensuring sufficient reaction amount for the active end in the end-modification step after polymerization, it is preferably below 120°C. More preferably, it is 50 to 100°C.

[0043] Regarding the type of polymerization reaction described above, there are no particular limitations; it can be carried out in batch (also known as "batch polymerization"), continuous polymerization, or other types. In continuous polymerization, one or more reactors connected together can be used. The reactor is a tank type or a tubular type equipped with a stirrer. In batch polymerization, the molecular weight distribution of the resulting polymer is generally narrower, tending to be 1.0 or higher and less than 1.8 in terms of Mw / Mn. In continuous polymerization, the molecular weight distribution is generally wider, tending to be 1.8 or higher and less than 3 in terms of Mw / Mn.

[0044] In the manufacturing method of the present invention, after obtaining a vinyl aromatic copolymer having a branched structure and active ends in the polymerization step, a compound having at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups, and hydroxyl groups (including precursors, also referred to as modifiers) is reacted with the active ends to form functional groups. The modifier may also be a polymerization initiator that forms functional groups in the polymerization step. Functional groups are introduced into the copolymer using such polymerization initiators or modifiers.

[0045] There are no particular limitations on the reaction temperature and reaction time when reacting compounds (including precursors) with functional groups at the active end, but it is preferred to react them at 0 to 120°C for more than 30 seconds. There is no particular limitation on the amount of functionalized polymerization initiators and modifiers added. The total mole number of the functionalized modifiers is preferably in the range of 0.05 to 6 times the equivalent number of active species derived from the polymerization initiator or polyfunctional initiator. The lower limit is more preferably 0.3, more preferably 0.5, and particularly preferably 0.7. On the other hand, the upper limit is more preferably 3 times, more preferably 2 times, and particularly preferably 1.5 times. From the viewpoint of obtaining a sufficient modification rate in the target modified vinyl aromatic copolymer, an addition amount of 0.05 times or more is preferred.

[0046] In batch polymerization, the final modification step can continue the modification reaction in the reactor used in the polymerization step, or it can be transferred to the next reactor for modification. In continuous polymerization, it is transferred to the next reactor. The final modification step is preferably carried out immediately after the polymerization step, preferably with the modifier mixed within 5 minutes to allow the reaction to proceed. The reactor used for the modification reaction is preferably one capable of thorough stirring. Specifically, there are static mixer reactors, tank reactors with agitators, etc.

[0047] The end-modification step involves reacting a modifier having at least one functional group selected from amino, alkoxysilyl, or hydroxyl groups with structural units (c) of vinyl aromatic copolymers, particularly those derived from conjugated dienes. The modifier must have an amino, alkoxysilyl, or hydroxyl group as a functional group; other functional groups, such as halogen, ketone, ester, amide, or epoxy groups, may also be present, provided they do not impede the purpose of this invention.

[0048] Regarding modifiers containing amine groups, there are no particular limitations. Specifically, examples include compounds with functional groups bonded to the amine group and the active ends of the polymer, and preferably without active hydrogen. Regarding the amine group, there are no particular limitations. Specifically, it is preferably a functional group that is inactive relative to the alkali metal, preferably a disubstituted amine group, i.e., a tertiary amine, a protected monosubstituted amine group, or an amine group with two hydrogens protected. Furthermore, examples of protected monosubstituted amine groups or amine groups with two hydrogens protected include those formed by replacing one hydrogen of a monosubstituted amine group or two hydrogens of an amine group with trialkylsilyl groups.

[0049] There are no particular limitations on modifiers containing alkoxysilyl groups, but specific examples include: compounds with multiple alkoxysilyl groups within the molecule (including compounds with silicon groups bonded to multiple alkoxy groups), and compounds with alkoxysilyl groups within the molecule and functional groups bonded to the active ends of the polymer. Furthermore, these are preferably compounds without active hydrogen atoms.

[0050] There are no particular limitations on the modifiers that form hydroxyl groups. Specifically, they can be listed as: compounds that have functional groups that bond to the active ends of the polymer and generate hydroxyl groups after the bonding reaction; compounds that do not bond to the active ends of the polymer and generate hydroxyl groups through subsequent reactions such as hydrolysis; and preferably compounds that do not have active hydrogen. Examples of compounds that have a functional group that forms a hydroxyl group after a bonding reaction include compounds with ketone, ester, amide, or epoxy groups. Examples of compounds that have a functional group that forms a hydroxyl group after a bonding reaction via hydrolysis or similar reactions include compounds with alkoxysilyl or aminosilyl groups.

[0051] Specific examples of modifiers are as follows. There are no particular limitations on compounds that bond to the active ends of a polymer to form amine groups at the polymer's ends; examples include C=N double-bonded compounds such as N,N'-dicyclohexylcarbodiimide. There are no particular limitations on compounds that bond to the active ends of a polymer to form amine and hydroxyl groups at the polymer ends. Examples include: ketone compounds containing amine groups such as N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone (milchlerone) and N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone; cyclic urea compounds such as N,N'-dimethylimidazolidineone and N-methylpyrrolidone; cyclic amides, i.e., endamides; epoxides containing amine groups such as N,N,N',N'-tetracyclooxypropyl-1,3-diaminomethylcyclohexane; and epoxides containing nitrogen-containing heterocyclic groups as described in Japanese Patent Application Laid-Open No. 2001-131227. There are no particular limitations on compounds that bond with the active ends of a polymer to form alkoxysilane groups at the polymer ends. Examples include: trimethoxychlorosilane, triethoxychlorosilane, diphenoxydichlorosilane, and other haloalkoxysilane compounds; and bis(trimethoxysilyl)ethane, bis(3-triethoxysilylpropyl)ethane, and other polyfunctional alkoxysilane compounds. There are no particular limitations on compounds that bond to the active ends of a polymer to form alkoxysilyl and hydroxyl groups at the ends of the polymer. Examples include 3-epoxypropoxypropyltrimethoxysilane and polysiloxane compounds having 3-epoxypropoxypropyltriethoxysilane epoxy and alkoxysilyl groups within the molecule.

[0052] There are no particular limitations on compounds that bond to the active ends of a polymer to form amino and alkoxysilane groups at the polymer ends. Examples include: alkoxysilane compounds with alkyl groups having amino substituents such as 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropyldimethoxymethylsilane, 3-dimethylaminopropyltriethoxysilane, bis(3-trimethoxysilylpropyl)methylamine, and bis(3-triethoxysilylpropyl)methylamine; N-[3-(triethoxysilyl)-propyl]-N,N'-diethyl-N'-trimethylsilyl-ethane-1,2-diamine, and 3-(4-trimethylsilyl-1-piperyl)-propyl]-N,N'-diethyl-N'-trimethylsilyl-ethane-1,2-diamine. 1-[3-(triethoxysilyl)propyl]-4-methylphenylene oxide, etc., as described in WO2007 / 034785, are alkoxysilane compounds with a protected one-substituted amino group; N-[2-(trimethoxysilyl)-ethyl]-N,N',N'-trimethylethane-1,2-diamine, 1-[3-(triethoxysilyl)-propyl]-4-methylphenylene oxide. 2-(trimethoxysilyl)-1,3-dimethylimidazolidine, bis-(3-dimethylaminopropyl)-dimethoxysilane, and other alkoxysilane compounds with multiple substituted amino groups as described in WO2008 / 013090; 1,4-bis[3-(trimethoxysilyl)propyl]piperazine 1,4-Bis[3-(triethoxysilyl)propyl]piperazine The alkoxysilane compounds with nitrogen-containing heterocycles described in WO2011 / 040312; 3-[N,N-bis(trimethylsilyl)amino]propyltrimethoxysilane, 3-[N,N-bis(trimethylsilyl)amino]propylmethyldiethoxysilane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silanecyclopentane, 2,2-diethoxy-1-(3-triethoxysilylpropyl)-1-aza-2-silanecyclopentane, and alkoxysilane compounds with azasilyl groups described in WO2011 / 129425, etc. There are no particular limitations on compounds that bond to the active ends of a polymer to form hydroxyl groups at the polymer ends, and examples include epoxides such as ethylene oxide and propylene oxide, and ketone compounds such as benzophenone.

[0053] The modified copolymers of the present invention, or the modified vinyl aromatic copolymers of the present invention obtained by the above-described manufacturing method, can be modified by at least one reactive functional group selected from the group consisting of amino groups, alkoxysilyl groups, and hydroxyl groups. Therefore, they can be molded and cured individually, or other polymerizable resins can be used for functional group modification and the synthesis of high molecular weight multi-branched components. In particular, the modified vinyl aromatic copolymers of the present invention, when used to obtain conjugated diene compounds alone, and / or conjugated diene copolymers (rubbers) formed by copolymerizing conjugated diene compounds with other monomers, can be used for functional group modification and the synthesis of high molecular weight multi-branched components. In the modified vinyl aromatic copolymer of the present invention, the proportion of multi-branched components is preferably 40% or more, and more preferably 50% to 80% of the area.

[0054] The modified copolymer of the present invention is an excellent modifier for conjugated diene (co)polymers (rubber). The detailed mechanism is not yet clear, but it is inferred that by introducing appropriate functional groups into the modified copolymer of the present invention, the rubber is modified into a modified conjugated diene copolymer (modified rubber), and it becomes easier to concentrate near the reinforcing filler, thus increasing the reinforcing effect of the reinforcing filler and improving the wear resistance of the resulting crosslinked product. Furthermore, it can be inferred that by modifying the rubber, the affinity between the modified conjugated diene copolymer of the present invention and the reinforcing filler is improved, and the dispersion state of each component such as the reinforcing filler in the resin composition is ideal for improving the physical properties of the resulting crosslinked product (e.g., improved abrasion resistance, improved handling stability, dry grip performance, and wet grip performance). On the other hand, it is speculated that if the functional group number of the modified conjugated diene copolymer becomes too large, the interaction between the copolymers adsorbed on the reinforcing filler will lead to the aggregation of the reinforcing filler, and the copolymer will not help to improve the affinity between the modified conjugated diene copolymer and the reinforcing filler.

[0055] The average number of functional groups in each molecule of the modified vinyl aromatic copolymer can be obtained from the equivalent (g / eq) of the functional groups of the modified vinyl aromatic copolymer (A) and the number average molecular weight Mn converted from styrene, and by the following formula (1). The average number of functional groups in each molecule = [(number average molecular weight Mn) / (average molecular weight of divinyl aromatic compound units and monovinyl aromatic compounds)] / (equivalent number of functional groups) (1) Furthermore, the equivalent of the functional groups in the modified vinyl aromatic copolymer (A) refers to the mass of the divinyl aromatic compound units and monovinyl aromatic compounds bonded to each functional group. The equivalent of the functional groups can be calculated using 1H-NMR or 13C-NMR from the area ratio of the peaks originating from the functional groups to the peaks originating from the polymer backbone.

[0056] The amount of modifier added to the modified vinyl aromatic copolymer (A) is preferably 1 to 200 parts by weight relative to 100 parts by weight of the unmodified multifunctional vinyl aromatic copolymer. More preferably, the upper limit is 100 parts by weight, more preferably 60 parts by weight, more preferably 50 parts by weight, and most preferably 40 parts by weight. When the amount of added modifier is more than 200 parts by weight, the dispersibility of the reinforcing filler (D) is poor, the processability deteriorates, and the abrasion resistance of the resulting crosslinked product tends to decrease. When the amount is less than 1 part by weight, the dispersibility of the reinforcing filler (D) is poor, and the dispersion state of the reinforcing filler (D) tends to be undesirable for improving the physical properties of the resulting crosslinked product. Furthermore, the amount of modifier added to the modified vinyl aromatic copolymer (A), having at least one functional group selected from amino, alkoxysilyl, or hydroxyl groups, can be determined using various analytical instruments such as nuclear magnetic resonance spectroscopy.

[0057] The modified vinyl aromatic copolymer of the present invention contains 0.5 to 45.0 mol% of structural units (a) derived from divinyl aromatic compounds. When the structural unit consists only of structural units (a), (b), and (c), the mole fraction of structural unit (a) is 0.005 to 0.45 relative to the sum of structural units (a), (b), and (c). That is, 0.5 to 45 moles. This mole fraction is calculated by the following formula (2). (a) / [(a)+(b)+(c)] (2) Here, (a): molar fraction of structural unit (a) derived from divinyl aromatic compounds, and (b): molar fraction of structural unit (b) derived from monovinyl aromatic compounds, and (c): molar fraction of structural unit (c) derived from conjugated diene compounds. The lower limit of the molar fraction of structural unit (a) is preferably 0.006, more preferably 0.007. The upper limit is preferably 0.40, more preferably 0.35. Even more preferably, it is 0.01 to 0.30. That is, even more preferably 1 to 30 molars. The best is 0.03 to 0.15. That is, best is 3 to 15 molars. In addition, when the structural units other than structural units (a), (b) and (c) are included, the lower limit of the preferred content is 0.2 mol%, more preferably 0.4 mol%, and even more preferably 0.6 mol%. Furthermore, the upper limit is 35 mol%, more preferably 30 mol%, and even more preferably 25 mol.

[0058] When the structure consists only of structural units (a), (b) and (c), the mole fraction of structural unit (b) is calculated by the following formula (3). (b) / [(a)+(b)+(c)] (3) Here, (a), (b) and (c) are synonyms with equation (2). The modified vinyl aromatic copolymer of the present invention contains 0.5 to 99.0 mol% of structural units (b) derived from monovinyl aromatic compounds. The molar percentage is 0.005 to 0.99. A preferred lower limit is 0.006. A more preferred lower limit is 0.007. A more preferred upper limit is 0.90, more preferably 0.85. Most preferably 0.015 to 0.65. That is, even more preferably 1 to 85 mol%, most preferably 1.5 to 65 mol%. In addition, when structural units other than structural units (a), (b) and (c) are included, the preferred molar fraction of structural unit (b) is also within the range described above.

[0059] When the structure consists only of structural units (a), (b) and (c), the molar fraction of structural unit (c) is calculated by the following formula (4). (c) / [(a)+(b)+(c)] (4) Here, (a), (b) and (c) are synonyms with equation (2). The modified vinyl aromatic copolymer of the present invention contains 0.5 to 99.0 mol% of structural units (c) derived from a conjugated diene compound. The molar percentage is 0.005 to 0.99. A preferred lower limit is 0.05. A more preferred lower limit is 0.010. A more preferred lower limit is 0.10. Furthermore, a preferred upper limit is 0.90, more preferably 0.85. Even more preferably, 0.20 to 0.85. That is, even more preferably 20 to 85 mol%, most preferably 20 to 80 mol%. In addition, when structural units other than structural units (a), (b) and (c) are included, the preferred molar fraction of structural unit (c) is also within the above range.

[0060] The modified vinyl aromatic copolymer of the present invention preferably contains 1 to 30 mol% of structural units derived from compounds having functional groups. The lower limit is more preferably 3 mol%, and even more preferably 5 mol%. The upper limit is more preferably 30 mol%, and even more preferably 20 mol%.

[0061] In addition to the structural units described above, the modified vinyl aromatic copolymers of the present invention may also contain other structural units. Details of these other structural units can be understood from the description of the manufacturing method. The modified vinyl aromatic copolymer of the present invention has a molecular weight (Mn) of 500 to 30,000, calculated using gel permeation chromatography based on the equivalent molecular weight of standard polystyrene. A lower limit is preferred to be 600, more preferably 700, even more preferably 800, and particularly preferably 900. On the other hand, an upper limit is preferred to be 25,000, more preferably 20,000, even more preferably 15,000, and particularly preferably 10,000. If Mn is less than 500, the amount of functional groups contained in the copolymer decreases, thus tending to reduce reactivity with the active ends of the conjugated diene copolymer. If Mn exceeds 30,000, in addition to the tendency to form gels, there is a tendency to decrease processability and tensile elongation at break. The molecular weight distribution is 30.0 or less, preferably 25.0 or less. A lower limit is more preferably 1.3, and even more preferably 1.6. Furthermore, the preferred upper limit is 20.0, even better is 15.0, and the best is 10.0. If Mw / Mn exceeds 30.0, in addition to the tendency for the processing characteristics of the copolymerized rubber to deteriorate, there is also a tendency for gelation to occur.

[0062] The modified vinyl aromatic copolymer of the present invention is soluble in solvents selected from toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform, but advantageously soluble in any of the aforementioned solvents. Since the modified vinyl aromatic copolymer of the present invention is multifunctional, in order to ensure that at least 95 mol% of the structural unit (a) derived from divinylbenzene is a crosslinked structural unit (a1) represented by the preceding formula (1), and simultaneously soluble in the solvent, the active species and the vinyl group of divinylbenzene must be within a specific ratio range. It is then preferable that at least 50 g is dissolved in 100 g of solvent. More preferably, at least 80 g is dissolved.

[0063] The modified vinyl aromatic copolymer of the present invention, having at least one reactive functional group selected from the group consisting of amino, alkoxysilyl, and hydroxyl groups, can be molded and cured independently, and can also be used for functional group modification and the synthesis of high molecular weight multi-branched components with other polymerizable resins. In particular, the modified vinyl aromatic copolymer of the present invention, when used to obtain conjugated diene compounds alone and / or conjugated diene copolymers (rubbers) formed by copolymerizing conjugated diene compounds with other monomers, can be used for functional group modification and the synthesis of high molecular weight multi-branched components.

[0064] By copolymerizing the multifunctional vinyl aromatic copolymer (A) of the present invention, which is used as a raw material, with 1) a conjugated diene compound (B), or 2) a conjugated diene compound (B) and an aromatic vinyl compound (C), a modified conjugated diene copolymer of the present invention having a branched polymeric modifying group (A) based on a modified vinyl aromatic copolymer can be obtained. Without using the aromatic vinyl compound (C), modified diene rubbers such as butadiene rubber or isoprene rubber can be obtained; by using the aromatic vinyl compound (C), modified conjugated diene copolymers such as modified SBR can be obtained. Since these modified conjugated diene copolymers exhibit rubber properties, they are also called modified copolymer rubbers.

[0065] The polymerization steps for obtaining the modified conjugated diene copolymer of the present invention consist of a polymerization step and an end-modification step. The polymerization step uses an alkali metal compound or an alkaline earth metal compound as a polymerization initiator to polymerize the conjugated diene compound (B), or to copolymerize the conjugated diene compound (B) and an aromatic vinyl compound (C) to obtain a conjugated diene copolymer with active ends. The end-modification step introduces a branched polymeric modifier (A) based on the aforementioned modified vinyl aromatic copolymer.

[0066] Examples of conjugated diene compounds (B) include: 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred. These compounds can be used alone or in combination of two or more.

[0067] As an aromatic vinyl compound (C), the following may be used alone or in combination of two or more: styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, vinylxylene, 4-cyclohexylstyrene, 2,4,6-trimethylstyrene, tributoxydimethylsilylstyrene and isopropoxydimethylsilylstyrene, etc., with styrene being particularly preferred.

[0068] When 1,3-butadiene is used as the conjugated diene compound (B) and styrene is used as the aromatic vinyl compound, styrene-butadiene rubber (SBR) is obtained. When styrene is not used as the aromatic vinyl compound and 1,3-butadiene is used as the conjugated diene compound (B), butadiene rubber (BR) is obtained. When isoprene is used as the conjugated diene compound (B) and there is no aromatic vinyl compound (C) as a structural unit, it becomes isoprene rubber (IR). Among these, styrene-butadiene rubber (SBR) exhibits excellent and particularly superior wear resistance, heat resistance, and aging resistance.

[0069] In the method for manufacturing the modified conjugated diene copolymer of the present invention, the polymerization step and the end-modification step can be carried out in the same manner as the polymerization step and the end-modification step of the modified vinyl aromatic copolymer described above. The polymerization initiator used in the polymerization step and the functionalized compound used in the end-modification step can both be the polymerization initiator and the functionalized compound described above.

[0070] In this polymerization, the polymerization or copolymerization of the conjugated diene compound (B) is preferably carried out by solution polymerization in an inert solvent. There are no particular limitations on the polymerization solvent; hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons can be used. Specific examples include: aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, and decahydronaphthalene; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbon solvents consisting of mixtures thereof. Preferably, an organometallic compound is used beforehand to treat the aforementioned conjugated diene compounds and polymerization solvents separately, or to treat a mixture thereof. This allows for the treatment of heavy olefins and acetylenes contained in the conjugated diene compounds or polymerization solvents. The result is a polymer with a high concentration of active terminals, achieving a high modification rate.

[0071] The polymerization temperature for copolymerizing the conjugated diene compound (B) or the conjugated diene compound (B) with the aromatic vinyl compound (C) is not particularly limited, as long as it is the temperature at which living anionic polymerization takes place. From a production point of view, it is preferably above 0°C. From the viewpoint of sufficiently ensuring the reaction amount of the modified vinyl aromatic copolymer of the present invention having silane functional groups (c) represented by the preceding formula (2) and / or formula (3) relative to the active end after polymerization, it is preferably below 120°C. More preferably, it is 50 to 100°C. There are no particular limitations on the polymerization method when copolymerizing conjugated diene compound (B) or conjugated diene compound (B) with aromatic vinyl compound (C). It can be carried out in batch polymerization (also known as "batch polymerization"), continuous polymerization, etc. In continuous polymerization, one or more reactors connected together can be used. The reactor can be a tank type or a tubular type with an agitator. In batch polymerization, the resulting polymer generally has a narrow molecular weight distribution, easily exceeding 1.0 and less than 1.8 in terms of Mw / Mn. In continuous polymerization, the molecular weight distribution is generally wider, easily exceeding 1.8 and less than 3 in terms of Mw / Mn.

[0072] In the method for manufacturing the modified conjugated diene copolymer of the present invention, after the polymerization step and the end-modification step, the main chain of the obtained modified conjugated diene copolymer can be further modified by a main chain modification step. The main chain modification step involves silylation of the vinyl group of the main chain of the modified conjugated diene polymer with the aforementioned modified ends, and a silicone compound having at least one functional group selected from the group consisting of amino, alkoxysilyl, and hydroxyl groups, or a silicone compound forming at least one functional group selected from the group consisting of amino, alkoxysilyl, or hydroxyl groups, to modify the main chain. This step is the same as when using a polymerization initiator, as when using the aforementioned multifunctional initiator. The hydrosiliconization reaction can be carried out in an organic solvent solution or directly in the polymer state (solvent-free state) in a mixer. Specifically, by reacting a silicone compound such as a hydrosilane compound having the aforementioned functional groups in the presence of a catalyst, the vinyl groups of the main chain of a conjugated diene copolymer can be modified. Preferably, after the polymerization step in solution polymerization, a polymer solution with modified polymer ends is further used directly as described above.

[0073] There is no particular limitation on the silicon compounds that incorporate functional groups, but hydrosilane compounds are a good example. Specifically, any hydrosilane compound having at least one functional group selected from the group consisting of amino, alkoxy, silyl, or hydroxyl groups is acceptable. Preferably, a hydrosilane compound with the general formula HSiR”3-nXn (R” is not particularly limited, representing a hydrocarbon group with 1 to 20 carbon atoms, X represents a hydrocarbon or organosilicon compound group having at least one functional group selected from the group consisting of amino, alkoxy, hydroxyl, or amino, alkoxy, silyl, or hydroxyl groups, and n is 1 to 3) is an example. More preferably, n is 1, and even more preferably, R” represents a hydrocarbon with 1 to 3 carbon atoms. When the hydrosilane compound has this configuration, the yield of the hydrosilane reaction is high. Furthermore, as for silicon compounds with introduced functional groups, they can also be silicon compounds that, after hydrosilaneization, form at least one functional group selected from the group consisting of amino groups (monosubstituted amino groups, disubstituted amino groups), alkoxysilyl groups, or hydroxyl groups through hydrolysis or the like. There are no particular limitations on such silicon compounds, but examples include: hydrosilane compounds having a functional group that, through hydrolysis or the like, forms at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups, or hydroxyl groups. More specifically, examples include: hydrosilane compounds having protected monosubstituted amino groups, protected disubstituted amino groups, protected hydroxyl groups, etc. The term "protected hydroxyl group" here can be exemplified by, for example, a hydroxyl group formed by replacing the hydrogen atom of a trimethylsilyl group.

[0074] There are no particular limitations on silicone compounds containing alkoxy groups. Examples include: dimethyl monomethoxysilane, dimethyl monoethoxysilane, dimethyl monopropoxysilane, dimethyl monobutoxysilane, methyl dimethoxysilane, methyl diethoxysilane, methyl dipropoxysilane, ethyl diethoxysilane, trimethoxysilane, and triethoxysilane, which are organosiloxane compounds with H-Si groups and alkoxysilane groups in their molecules. There are no particular limitations on silicon compounds having disubstituted amino groups, but specific examples include: dimethylaminodimethylsilane, diethylaminodimethylsilane, diethylaminodiethylsilane, 3-diethylaminopropyldimethylsilane, 4-dimethylaminobutyldimethylsilane, and 6-diethylaminohexyldimethylsilane. There are no particular limitations on silicon compounds with protected monosubstituted amino groups, but specific examples include: N-methyl-N-trimethylsilylaminodimethylsilane and N-ethyl-N-trimethylsilylaminodiethylsilane.

[0075] There are no particular limitations on silicon compounds with protected disubstituted amino groups, but examples include: N,N-bistrimethylsilylaminodimethylsilane and N,N-bistrimethylsilylaminodiethylsilane.

[0076] There are no particular limitations on silicone compounds with protected hydroxyl groups, but some examples include: dimethyltrimethylsilaneoxysilane, diethyltrimethylsilaneoxysilane, and dibutyltrimethylsilaneoxysilane.

[0077] There are no particular limitations on the types of silicon compounds that form hydroxyl groups through hydrolysis. Examples include: alkoxysilane compounds such as dimethyl monomethoxysilane, dimethyl monoethoxysilane, methyl dimethoxysilane, trimethoxysilane, and triethoxysilane; and silicon compounds with epoxy groups such as dimethylepoxypropylsilane and diethylepoxypropylsilane.

[0078] When modifying the vinyl groups of the main chain of a butadiene-based polymer with terminal modifications, the amount of hydrosilane compound reacted can be arbitrary depending on the purpose, but it is preferably 1 to 10 mol relative to 1 mol of the butadiene-based polymer main chain. By modifying 1 to 10 mol relative to 1 mol of the main chain, as described later, when a resin composition is obtained by mixing the modified butadiene-based polymer with silica, good affinity can be obtained, resulting in a product with excellent processability. More preferably, it is 2 to 5 mol relative to 1 mol of the main chain.

[0079] When carrying out the hydrosiliconization reaction, a pre-existing catalyst can be used. There are no particular limitations on the catalyst; for example, platinum or platinum-containing catalysts are primarily used. Homogeneous platinum catalysts are preferred, such as chloroplatinic acid solution (i.e., Speier catalyst), Pt2 (divinyltetramethyldisiloxane)3 solution (i.e., Karstedt catalyst), and dichloro(η4-cyclo-1,5-diene)Pt(II). The amount of platinum catalyst used in the reaction is preferably 0.01 to 10 mmol / mol per unit of hydrosilane compound, more preferably 0.1 to 1 mmol / mol.

[0080] Furthermore, examples of catalysts used in the hydrosiliconization reaction include metallocene compounds containing any one of Ti, Zr, Hf, Ni, Co, Ru, and Rh, with a particular preference for reactants of titanocene compounds with organolithium or organoaluminum compounds.

[0081] The hydrosiliconization reaction is preferably carried out in the range of 20 to 150°C, and more preferably in the range of 50 to 120°C. Within this range, the reaction can be carried out for an appropriate reaction time, with fewer side reactions such as gelation, making it practical. Alternatively, when the polymerization solution is used directly, and the hydrosiliconization reaction is carried out immediately after the end-modification reaction, it can be carried out at the same temperature as the polymerization temperature. In the solution state, the reaction time is preferably in the range of 10 minutes to 5 hours, and more preferably in the range of 30 minutes to 2 hours.

[0082] Considering processability and physical properties, the weight-average molecular weight (converted to polystyrene) of the modified conjugated diene copolymer of the present invention is preferably between 100,000 and 2,000,000, more preferably between 150,000 and 1,000,000. The weight-average molecular weight can be determined by measuring the chromatogram using a GPC column with polystyrene gel as the packing material, and by using a calibration curve with standard polystyrene. In the differential molecular weight distribution curve obtained by gel permeation chromatography (GPC), when the total area is set to 100%, the area of ​​the region with a number average molecular weight (Mn) that is more than three times (3 Mp or more) the peak value on the lowest molecular weight side can be more than 10%. More preferably, it is more than 20% of the area. Most preferably, it is 25% to 80% of the area.

[0083] The modified conjugated diene copolymer of the present invention may contain 0.001 to 6% by weight of structural units (A1) derived from modified vinyl aromatic copolymers, 29 to 99.999% by weight of structural units (B1) derived from conjugated diene compounds, and 0 to 70% by weight of structural units (C1) derived from aromatic vinyl compounds. The structural unit (A1) derived from the modified vinyl aromatic copolymer (A) is preferably 0.001 to 5% by weight, more preferably 0.005 to 5% by weight, even more preferably 0.01 to 5% by weight, and most preferably 0.001 to 1% by weight. The structural unit (B1) derived from the conjugated diene compound (B) is 29 to 99.999% by weight, preferably 80 to 99.999% by weight, more preferably 90 to 99.995% by weight, and even more preferably 95 to 99.99% by weight. When using aromatic vinyl compound (C), the structural unit (A1) is in the same range as described above, and the structural unit (B1) is 30 to 97.999% by weight, preferably 45 to 94.995% by weight, and even more preferably 55 to 89.99% by weight. The structural unit (C1) derived from aromatic vinyl compound (C) is 2 to 50% by weight, preferably 5 to 45% by weight, and even more preferably 10 to 40% by weight.

[0084] The microstructure (cis, trans, and vinyl bond content) of the modified conjugated diene copolymer can be arbitrarily changed by using polar compounds, etc., but in the state before the end is modified, the content of vinyl bonds (1,2-bonds) in the conjugated diene units is preferably 10 to 80 mol%. When the modified conjugated diene copolymer of the present invention is used as a resin composition described later and further crosslinked for use as an automobile tire, in order to achieve a high balance between rolling resistance performance and wear resistance, it is preferably 20 to 75 mol%, more preferably 25 to 75 mol%, and even more preferably 25 to 70 mol%. Most preferably 25 to 45 mol%. In this case, the mass ratio of cis bonds to trans bonds in the conjugated diene bonded units is preferably cis bond / trans bond = 1 / 1.1 to 1.5.

[0085] In the polymer solution of the modified conjugated diene copolymer obtained by the above polymerization method, a reaction stopper may be added as needed. Examples of reaction stoppers include alcohols such as methanol, ethanol, and propanol; organic acids such as stearic acid, lauric acid, and octanoic acid; and water.

[0086] After the polymerization reaction of the modified conjugated diene copolymer, the metals contained in the polymer can be deashed as needed. For deashing methods, one can use, for example, contacting the polymer solution with oxidants such as water, organic acids, inorganic acids, or hydrogen peroxide to extract the metals, followed by separation of the aqueous layer.

[0087] The modified conjugated diene polymer obtained above, when obtained as a solution, can be solvent-removed and dried using conventional methods after adding antioxidants and additives as needed. This allows it to be used as a raw material for the resin composition described later. Specifically, this includes methods such as steam vaporization and dehydration drying, direct dehydration using a drum dryer, flash evaporation, and vent extruder.

[0088] There are no particular limitations regarding antioxidants; those already known can be used. Examples of antioxidants include phenolic stabilizers, phosphorus stabilizers, and sulfur stabilizers. Specifically, preferred antioxidants include, for example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenol) propionate, and 2-methyl-4,6-bis[(octylthio)methyl]phenol.

[0089] To remove or neutralize ionic substances as needed, alcohols such as water, methanol, ethanol, and isopropanol can be added, or carboxylic acids such as stearic acid, oleic acid, myristic acid, lauric acid, decanoic acid, citric acid, and malic acid, inorganic acid aqueous solutions, and carbon dioxide gas can also be added.

[0090] The resin composition of the present invention contains 100 parts by mass of a raw material rubber comprising 20 or more parts by mass of a modified conjugated diene polymer and 5 to 200 parts by mass of a filler.

[0091] The modified conjugated diene polymer content in 100 parts by weight of raw rubber is 20 parts by weight or more, preferably 40 parts by weight or more, more preferably 50 parts by weight or more, and even more preferably 60 parts by weight or more. If it is 20 parts by weight or more, the filler, which is the target of this invention, exhibits excellent dispersibility. When the resin composition of this embodiment is used as a vulcanizing composition, it exhibits excellent tensile properties, viscoelastic properties, and other properties. When used as a tire material, the tire can achieve excellent fuel consumption performance, grip performance, abrasion resistance, and rigidity. Furthermore, the content of the modified conjugated diene polymer is preferably 90 parts by weight or less, more preferably 80 parts by weight or less. By reducing it to 90 parts by weight or less, the Munich viscosity of the unvulcanized resin composition of this invention decreases, and processability is improved.

[0092] There are no particular limitations on raw material rubbers other than modified conjugated diene polymers. Examples include: conjugated diene polymers or their hydrides, random copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrides, block copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrides, other conjugated diene copolymers or their hydrides, non-diene polymers, natural rubber, etc.

[0093] There are no particular limitations on specific examples of conjugated diene polymers or their hydrides, such as butadiene rubber or its hydrides, isoprene rubber or its hydrides, etc.

[0094] There are no particular limitations on specific examples of random copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenates, such as styrene-butadiene copolymer rubber or its hydrogenates.

[0095] There are no particular limitations on specific examples of block copolymers of conjugated diene compounds and vinyl aromatic compounds or their hydrogenates, and examples include styrene-based elastomers such as styrene-butadiene block copolymers or their hydrogenates, and styrene-isoprene block copolymers or their hydrogenates.

[0096] There are no particular limitations on other specific examples of conjugated diene copolymers or their hydrogenated derivatives, such as acrylonitrile-butadiene rubber or its hydrogenated derivatives.

[0097] For non-diene polymers, there are no particular limitations. Examples include: olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, and ethylene-octene rubber; butyl rubber; brominated butyl rubber; acrylic rubber; fluororubber; polysiloxane rubber; chlorinated polyethylene rubber; epichlorohydrin rubber; α,β-unsaturated nitrile-acrylate-conjugated diene copolymer rubber; urethane rubber; and polysulfide rubber.

[0098] In this invention, when the modified conjugated diene polymer is modified styrene-butadiene rubber, polybutadiene is preferably used as another rubber. Furthermore, when the modified butadiene polymer is modified polybutadiene, natural rubber or polyisoprene rubber is preferably used as another rubber.

[0099] From the viewpoint of balancing performance and processing characteristics, the weight-average molecular weight of the aforementioned rubbery polymers is preferably between 2,000 and 2,000,000, and more preferably between 5,000 and 1,500,000. Alternatively, low molecular weight so-called liquid rubbers may also be used. These rubbery polymers may be used alone or in combination of two or more. The weight-average molecular weight mentioned herein is the weight-average molecular weight (Mw) converted from polystyrene measured by gel permeation chromatography (GPC).

[0100] Regarding the amount of filler relative to the raw rubber, if a large amount of filler is used, the hardness and modulus will increase. Adjustments should be made according to the application to achieve the desired physical properties. Within this range, the filler dispersion is good and the processability is satisfactory. For tire applications, 5 to 150 parts by weight of filler is preferred, and for footwear applications, 30 to 200 parts by weight is preferred. Within the scope of this embodiment, a wide range of applications, from soft to hard, can be accommodated.

[0101] The resin composition of the present invention comprises, relative to 100 parts by weight of raw rubber, at least 0.5 to 200 parts by weight of at least one reinforcing filler selected from the group consisting of silica-based inorganic fillers, metal oxides, metal hydroxides and carbon black.

[0102] Regarding the silica-based inorganic filler contained in the resin composition, it is preferable to use solid particles whose main component is SiO2 or silicate. Here, the so-called main component refers to the component that accounts for more than 50% by mass in the whole, more preferably more than 70% by mass, and even more preferably more than 90% by mass.

[0103] Specific examples of silica-based inorganic fillers include: silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, glass fiber, and other inorganic fibrous materials. A single silica-based inorganic filler can be used, or two or more can be used in combination. Furthermore, surface-hydrophobic silica-based inorganic fillers, or mixtures of silica-based inorganic fillers and inorganic fillers other than silica-based fillers, can also be used. Among these, silica and glass fiber are preferred, and silica is even more preferred.

[0104] Regarding silica, dry silica, wet silica, and synthetic silicate silica can be used, but from the viewpoint of having both improved destructive properties and wet slip resistance performance, wet silica is preferred. In the case of silica, silica with a BET specific surface area of ​​50 to 500 m² / g is used. By incorporating this silica, excellent low fuel consumption, wear resistance, wet skid resistance, and handling stability can be obtained. Furthermore, even when using silica with a high specific surface area, i.e., silica with a fine particle size, it can be well dispersed. Regarding the silica with a fine particle size, it can contain cetyltrimethylammonium bromide (CTAB) with a specific surface area of ​​180 m² / g or more, or BET specific surface area of ​​185 m² / g or more. The average primary particle size is, for example, 25 nm or less. By incorporating such silica with a fine particle size, excellent low fuel consumption, abrasion resistance, wet skid resistance, and handling stability can be obtained in the resin composition of this embodiment.

[0105] There are no particular limitations on the aggregate size of silica particles, which can be 30 nm or larger. This aggregate size provides good dispersibility, excellent reinforcement, low fuel consumption, wear resistance, wet skid resistance, and handling stability. The aggregate size, also known as the aggregate diameter or the maximum frequency Stokes equivalent diameter, is the particle size when an aggregate of silica composed of multiple primary particles is considered as a single particle. The aggregate size can be measured, for example, using a disc-type centrifugal sedimentation particle size distribution measuring device such as the BI-XDC (manufactured by Brookhaven Instruments Corporation). Specifically, it can be measured using the method described in Japanese Patent Application Publication No. 2011-132307. There is no particular limitation on the average primary particle size of silicon dioxide, but it is preferably below 25 nm.

[0106] In the resin composition of the present invention, the amount of silica with the aforementioned microparticle size is not particularly limited, but is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more, relative to 100 parts by mass of rubber component. If it is 5 parts by mass or more, the effect of incorporating the aforementioned microparticle silica can be sufficiently obtained. The amount of silica with this microparticle size is 200 parts by mass or less, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less. If it is 200 parts by mass or less, substantially good processability can be obtained.

[0107] The resin composition of the present invention is preferably the above-mentioned resin composition further comprising 5 to 100 parts by weight of silicon dioxide or carbon black with a BET specific surface area of ​​less than 185 m2 / g as a reinforcing filler.

[0108] In the resin composition of the present invention, it is preferable to further use silica with a BET nitrogen adsorption specific surface area (N2SA) of less than 185 m2 / g as a reinforcing filler, more preferably less than 150 m2 / g, and even more preferably 50 m2 / g or more. Within this range, a good balance between reinforcing and dispersing properties is achieved. Furthermore, suitable particle sizes can be used depending on the application.

[0109] Regarding carbon black, according to ASTM's classification of carbon black for rubber, there are N110, N220, N330, N339, N550, and N660, which can be selected according to the application. By blending carbon black, reinforcement can be improved, and when used in tire tread applications, dry grip performance can be enhanced. The carbon black with a nitrogen adsorption specific surface area (N2SA) using the BET method is preferably less than 185 m² / g, preferably above 30 m² / g, and more preferably in the range of 50 to 130 m² / g. Within this range, a good balance between reinforcement and dispersibility is achieved. For tire tread applications, N220, N330, and N339 are even more preferred.

[0110] Furthermore, in addition to the aforementioned silicon dioxide, other reinforcing fillers may be used in the resin composition of the present invention. There are no particular limitations on these other reinforcing fillers; preferably, the metal oxide used as the reinforcing filler is a solid particle with the chemical formula MxOy (where M represents a metal atom, and x and y represent integers from 1 to 6) as its main component. Here, "main component" refers to a component that accounts for 50% or more by mass of the total, preferably 70% or more by mass, and more preferably 90% or more by mass. In the case of metal oxides, for example, aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, etc. can be used. Examples of metal hydroxides used as reinforcing fillers include aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide. The aforementioned metal oxides or metal hydroxides used as other reinforcing fillers may be used alone or in combination of two or more. Furthermore, mixtures with other inorganic fillers may also be used.

[0111] In the resin composition of the present invention, silane coupling agents may also be used. There are no particular limitations on the silane coupling agent, and examples include compounds having both a silicon dioxide affinity portion and a polymer affinity portion in their molecules, such as sulfide compounds, mercapto compounds, vinyl compounds, amino compounds, epoxypropoxy compounds, nitro compounds, chlorine compounds, etc. Examples of sulfide compounds include: bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, and 3-trimethoxysilylpropyl-N. N-Dimethylthioamine methyltetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthioamine methyltetrasulfide, 2-trimethoxysilylethyl-N,N-dimethylthioamine methyltetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-octylthio-1-propyltriethoxysilane, etc. Examples of mercapto compounds include: 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane. Examples of vinyl compounds include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of amino compounds include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. Examples of epoxypropoxy compounds include: γ-epoxypropoxypropyltriethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropylmethyldiethoxysilane, and γ-epoxypropoxypropylmethyldimethoxysilane. Examples of nitro compounds include 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane. Examples of chlorine compounds include 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, and 2-chloroethyltriethoxysilane. Other compounds include, for example, octyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and hexadecyltrimethoxysilane.

[0112] These silane coupling agents can be used alone or in combination with two or more. Among these silane coupling agents, from the viewpoint of maximizing the reinforcing effect, sulfur-containing silane coupling agents such as sulfide compounds and mercapto compounds are preferred, and bis(3-triethoxysilylpropyl) disulfide, bis(3-triethoxysilylpropyl) tetrasulfide, and 3-mercaptopropyltrimethoxysilane are even more preferred. The amount of silane coupling agent incorporated relative to 100 parts by weight of silica is 1 to 20 parts by weight, preferably 2 to 15 parts by weight. If the silane coupling agent is incorporated within this range, the dispersibility of silica is further improved, the processability is enhanced, and the abrasion resistance is increased, thereby improving the properties of the vulcanized rubber.

[0113] In the resin composition of the present invention, the hardness and modulus can be adjusted by using a plasticizer. There are no particular limitations on the type of plasticizer; for example, the same oil as the aforementioned stretching oil can be used. In addition, various natural oils, synthetic oils, low molecular weight polymers, etc., can be used. Furthermore, conventional processing aids can be used.

[0114] The resin composition of the present invention can also be used as a resin composition that undergoes further crosslinking treatment by adding vulcanizing agents (crosslinking agents), admixtures, etc. There are no particular limitations on such crosslinking agents; for example, sulfur-based vulcanizing agents, organic peroxides, etc., can be used. There are no particular restrictions on sulfur-based vulcanizing agents; for example, sulfur, etc., can be used. For organic peroxides, such as porphyrin disulfides, examples include: benzoyl peroxide, diisopropylphenyl peroxide, di-tert-butyl peroxide, tert-butylisopropylphenyl peroxide, cumene hydroperoxide, etc. There is no particular limitation on the amount of vulcanizing agent used, but it is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, relative to 100 parts by weight of the conjugated diene copolymer. As for the vulcanization method, conventional methods can be used, and the vulcanization temperature is preferably, for example, 120°C to 200°C, more preferably 140°C to 180°C. Vulcanization accelerators or vulcanization aids may also be added as needed. There are no particular restrictions on vulcanization accelerators, and at least one of the following can be used: sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine or aldehyde-amine, imidazoline, or xanthate vulcanization accelerators.

[0115] Furthermore, vulcanizing accelerators can be added as needed. There are no particular restrictions on vulcanizing accelerators, but zinc oxide, stearic acid, etc. can be used, for example. Anti-aging agents can also be used further.

[0116] The resin composition of the present invention can be manufactured by mixing the above-mentioned components. The method of mixing the modified conjugated diene copolymer with at least one reinforcing filler selected from the group consisting of silica-based inorganic fillers, metal oxides, metal hydroxides, and carbon black, and a silane coupling agent as desired, is not particularly limited. Examples include melt mixing methods using general mixers such as open rollers, Bamboo mixers, kneaders, single-screw extruders, twin-screw extruders, and multi-screw extruders, as well as methods that dissolve and mix the components and then remove the solvent by heating. Among these, melt mixing methods performed by rollers, Bamboo mixers, kneaders, and extruders are preferred from the viewpoint of productivity and excellent mixing properties. Furthermore, methods that mix the rubber components with various admixtures in one step or methods that involve multiple mixing steps can also be used.

[0117] In this invention, the degree of polymer concentration on the surface of the filler can be expressed by the bound rubber production capacity of the modified conjugated diene polymer at 25°C. From the viewpoint of improving abrasion resistance and breaking strength, the bound rubber production capacity in the resin composition after the above-mentioned mixing is preferably 15% by mass or more, and more preferably 20% by mass or more.

[0118] Resin components can also be used as vulcanizing components that are vulcanized by vulcanizing agents. Vulcanizing agents can include, for example, free radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur, and sulfur compounds. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, and high-molecular-weight polysulfides.

[0119] During vulcanization, vulcanization accelerators may be used as needed. Commonly known vulcanization accelerators include, for example, sulfenamide-based, guanidine-based, thiuram-based, aldehyde-amine-based, aldehyde-amine-based, thiazole-based, thiourea-based, and dithiocarbamate-based vulcanization accelerators. Vulcanization aids may include zinc oxide and stearic acid.

[0120] In order to improve processability, a rubber softener may be incorporated into the resin composition of the present invention. The rubber softener is preferably a mineral oil, a liquid, or a low-molecular-weight synthetic softener.

[0121] Mineral oil-based rubber softeners, also known as processing oils or extender oils, used to soften, compatibilize, and improve the processability of rubber, are mixtures of aromatic rings, cycloalkane rings, and paraffin chains. Paraffin chains comprising more than 50% of the total carbon atoms are called paraffinic, cycloalkane chains comprising 30 to 45% of the carbon atoms are called cycloalkane, and aromatic chains comprising more than 30% of the carbon atoms are called aromatic. In this embodiment, the rubber softener is preferably cycloalkane-based and / or paraffinic.

[0122] There is no particular limitation on the amount of rubber softener incorporated, but it is preferably 10 to 80 parts by weight, and more preferably 20 to 50 parts by weight, relative to 100 parts by weight of the conjugated diene copolymer.

[0123] In the resin composition of this invention, other softeners or fillers besides those mentioned above may be used without compromising the purpose of this embodiment. Furthermore, various additives such as heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants may be used. Specifically, examples of fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. For softeners that can be added to adjust the hardness and flowability of a product as needed, examples include: flowable paraffin wax, castor oil, and linseed oil. For heat stabilizers, antistatic agents, weather stabilizers, anti-aging agents, colorants, and lubricants, conventional materials can be used.

[0124] The resin crosslinked compound of the present invention can be obtained by crosslinking resin components. For example, a tire can be formed by extrusion according to the shape of the tire (e.g., tread shape), heated and pressurized in a vulcanizing machine to produce a tread, and the tire as a target can be manufactured by assembling the tread with other parts.

[0125] The resin composition of the present invention, when used as a resin crosslinker, exhibits excellent mechanical strength and abrasion resistance. Therefore, as described above, it can be appropriately applied to structural components such as the tread of tires (low fuel consumption tires, large tires, high performance tires) or the sidewall components of tires. Furthermore, in addition to structural components, it can also be appropriately used in rubber belts, rubber hoses, footwear materials, etc. [Example]

[0126] The present invention will be described in more detail below with reference to the embodiments, but the present invention is not limited to these embodiments. In addition, unless otherwise specified, all parts in the examples are parts by weight, and the evaluation of each property is carried out by the following methods.

[0127] 1) Molecular weight and molecular weight distribution, as well as the area (%) of multi-branched components and the area (%) of components above 3 Mp. Molecular weight and molecular weight distribution measurements were performed using GPC (Tosoh, HLC-8220GPC) as the analytical column. The column consisted of two Tosoh TSKgel Multipore HXL-M columns, one TSKgel G1000 HXL column, and one TSKguardcolumn MP(XL) guard column. The solvent was tetrahydrofuran (THF), the flow rate was 1.0 ml / min, the column temperature was 38 °C, and the calibration curve obtained from monodisperse polystyrene was used. Furthermore, the area (%) of multi-branched components, as shown in Figure 1, represents the area of ​​the molecular weight range of uncoupled, unbranched diene copolymers with a peak molecular weight Mp of 2 times (2Mp) or more. Moreover, the area (%) of 3Mp or more represents the area of ​​the molecular weight range of uncoupled, unbranched diene copolymers with a peak molecular weight Mp of 3 times (3Mp) or more.

[0128] 2) Structure of modified vinyl aromatic copolymers The determination was made using a JNM-LA600 nuclear magnetic resonance spectrometer manufactured by JEOL Ltd., employing 13C-NMR and 1H-NMR analyses. Chloroform-d1 was used as the solvent, and the resonance line of tetramethylsilane was used as an internal standard. 3) Solvent solubility (cyclohexane) Dissolve 5.0 g of the modified vinyl aromatic copolymer in 95.0 g of cyclohexane, filter through a glass filter, wash the glass filter with 30 g of cyclohexane, and vacuum dry the glass filter at 60 °C. Then calculate the weight of the polymer portion on the filter. A dry weight of less than 0.025 g of polymer portion is considered ○, more than 0.025 g but less than 0.25 g is considered △, and more than 0.25 g is considered ×.

[0129] 4) Munich viscosity According to JIS K6300-1, the result is obtained using an L-shaped rotor, preheating for 1 minute, rotor running time of 4 minutes, and temperature of 100℃. 5) Gel portion To prepare a sample by dissolving 0.5 g of copolymer rubber in 100 mL of toluene, add 1.0 g of a 0.2 wt% Sudan III toluene solution and let stand for 1 hour. Filter the sample solution through a 0.2 μm PTFE membrane filter and vacuum dry the membrane filter at 40 °C. Visually observe the gel portions stained with Sudan III on the dried membrane filter; 0 gel portions are considered ○, 1 to 5 are considered △, and more than 6 are considered ×.

[0130] 6) Thermogravimetric Measurement (TGA) According to JIS K7120, the weight reduction at 350°C (TGA350) is calculated.

[0131] 7) Haze A sample prepared by dissolving 0.5g of copolymer rubber in 100g of toluene was placed in a quartz colorimetric cell. The haze value was measured using an integrating sphere transmittance measuring device (manufactured by Nippon Denshoku Co., Ltd., SZ-Σ90) with toluene as the reference sample.

[0132] 8) Vinyl bond content of conjugated diene copolymers (SBR) The sample was prepared as a carbon disulfide solution, and the infrared spectrum was measured in the range of 600 to 1000 cm⁻¹ using a solution bath. Based on the absorbance at a predetermined wavenumber, the percentage of vinyl bonds in the conjugated diene copolymer (SBR) was calculated using the formula from the Hampton method (styrene-butadiene copolymer). The apparatus used was a Spectrum 100 manufactured by PerkinElmer.

[0133] 9) Rubber content 0.4 g of the mixed uncured rubber was cut into 2 mm squares and placed in a sample tube along with 50 mL of toluene. The sample was left to stand at room temperature for 48 hours. Extraction was then performed using a glass filter, and both the toluene solution and the rubber fraction were dried. The weight of the rubber fraction remaining on the filter was calculated as the amount of bound rubber. The dried toluene solution was further dissolved in chloroform, and the proportion of polybutadiene was calculated using proton NMR. This value was then used to calculate the amount of bound rubber from the actual blending fraction. The amount of bound rubber in Comparative Example 3 was set to 100 and expressed as an index.

[0134] 10) Tensile strength The 300% modulus was measured using the tensile test method according to JIS K6251, and the measured value of the crosslinked rubber obtained in Comparative Example 3 was set to 100 and indexed. The larger the index value, the better the tensile strength.

[0135] 11) Wear resistance Using the method described in JIS K6264 with a Lamborn-type abrasion tester, the abrasion amount with a slip ratio of 25% was measured. The measured value of the crosslinked rubber obtained in Comparative Example 3 was set to 100 and indexed. The measurement temperature was room temperature. The higher the index value, the better the abrasion resistance.

[0136] The raw materials used in the examples, or their abbreviations, are described below. DVB-630; a mixture of divinylbenzene and ethylvinylbenzene; divinylbenzene content 63.0 wt%, manufactured by Nippon Steel Chemical Materials. BHT;2,6-Di-tert-butyl-p-cresol BTESPA; Bis(3-trimethoxysilylpropyl)methylamine

[0137] Example 1 Synthesis of modified vinyl aromatic copolymer (A-1) After adding 120 ml (93.5 g) of ethylcyclohexane, 0.77 ml (4.0 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane, and 12.5 ml of a hexane solution containing 1.28 g (20.0 mmol) of n-butyllithium (based on purity) at 50 °C, 2.12 g of pre-removed impurity DVB-630 (a mixture of the following structural formulas) (10.0 mmol of divinylbenzene (a mixture of intermediate and para components) and 6.26 mmol of ethylvinylbenzene (a mixture of intermediate and para components)) was added. 12.89 g (123.7 mmol) of styrene (structural formula below) The mixture was used to begin the first stage of polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 72°C. After the polymerization reaction was completed, a small sample of the polymerization solution was taken and analyzed by gas chromatography (GC). The results showed that no unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis showed that at the end of the first stage of polymerization, the copolymer had a Mn of 1730, a Mw of 3390, and a Mw / Mn ratio of 1.96. 4.09 g (20.0 mmol) of isoprene (structural formula below) was added to the reactor as an additional monomer. The second stage of polymerization was initiated. After the second stage of polymerization was completed, a small sample of the polymerization solution was taken for GC analysis. No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Further GPC analysis showed that at the end of the second stage of polymerization, the copolymer's Mn was 2150, Mw was 4340, and Mw / Mn was 2.02. Comparing the GPC dissolution curves of the sample at the end of the first stage of polymerization with those at the end of the second stage, the results showed that the GPC dissolution curves maintained approximately the same molecular weight distribution due to the addition of the fourth monomer, isoprene, and shifted towards the higher molecular weight side, confirming that the terminal active species were essentially completely converted into carboanions derived from isoprene. Therefore, 7.27 g (20.0 mmol) of 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP) was added as a modifier, and the modification reaction was carried out for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was completed, 4.72 g (40.0 mmol) of succinic acid was added, and the mixture was stirred and then filtered. Here, TESPTADSP, as shown in formula (2), is a modifier that simultaneously possesses alkoxysilyl and amine groups. The resulting polymerization solution was concentrated by devaporization and then dissolved in ethylcyclohexane, but no gel or microgel formation was observed. Next, to remove unreacted TESPTADSP, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer, causing it to separate into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by devaporization and then dissolved in ethylcyclohexane. The result was a yield of 25.05 g (95.0 wt%) of the modified vinyl aromatic copolymer A-1 on a solids basis. The analytical results of the modified vinyl aromatic copolymer A-1 are shown in Table 1.

[0138] The modified vinyl aromatic copolymer A-1 obtained has a Mn of 2650, a Mw of 5560, and a Mw / Mn ratio of 2.10. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer A-1 contained 4.55 mol% (4.94 wt%) of structural units derived from divinylbenzene, 2.84 mol% (3.09 wt%) of structural units derived from ethylvinylbenzene, 56.25 mol% (48.88 wt%) of structural units derived from styrene, 27.27 mol% (15.50 wt%) of structural units derived from isoprene, and 9.09 mol% (27.59 wt%) of structural units derived from 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP). This confirmed that 2.01 modifiers were introduced into each molecule of the modified vinyl aromatic copolymer. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 4.36 mol% (4.74 wt%), the degree of crosslinking (a1 / a) is 0.96. Furthermore, since the modified vinyl aromatic copolymer (A-1) contains 0.18 mol% (0.20 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.002. Also, approximately 100 mol% of the structural units derived from TESPTADSP are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 0.72 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (A-1) in 100 g of toluene was placed in a quartz cuvette. Using toluene as a reference sample, the haze (turbidity) was measured using an integrating sphere transmittance meter; the haze value was 0.02.

[0139] Synthesis of Comparative Example 1: Modified Vinyl Aromatic Copolymer (B-1) 4.37 mol (630.2 mL) of divinylbenzene (a mixture of 1,4-divinylbenzene and 1,3-divinylbenzene, the same applies to the following examples), 3.34 mol (457.5 mL) of ethylvinylbenzene (a mixture of 1-ethyl-4-vinylbenzene and 1-ethyl-3-vinylbenzene, the same applies to the following examples), 6.90 mol (749.9 mL) of anisole, and 345 mL of toluene were added to a 3.0 L reactor. 103.5 mmol (13.0 mL) of a boron trifluoride diethyl ether complex was added at 50 °C, and the reaction was allowed to proceed for 5 hours. After stopping the polymerization reaction with an aqueous sodium bicarbonate solution, the oil layer was washed three times with pure water, and the polymer was recovered by devastating the reaction under reduced pressure at 60 °C. The obtained polymer was weighed, confirming that 945.3 g of copolymer B-1 was obtained.

[0140] The resulting copolymer B-1 has an Mn of 624, a Mw of 2360, and an Mw / Mn ratio of 3.79, classifying it as a random copolymer. 13C-NMR and 1H-NMR analyses revealed resonance lines at the terminal groups of the benzene ring derived from anisole bonded to the main chain of copolymer B-1. The amount of anisole-derived structural units in the soluble polyfunctional vinyl aromatic polymer, calculated from the elemental analysis results and the number-average molecular weight converted from standard polystyrene, is 1.6 (units / molecule). It also contains 61.3 mol% of divinylbenzene-derived structural units and a total of 38.7 mol% of ethylvinylbenzene-derived structural units (excluding terminal structural units). The vinyl content in copolymer B-1 is 34.8 mol% (excluding terminal structural units). Furthermore, TMA measurements of the hardened material did not reveal a clear Tg, and the softening temperature was above 300°C. TGA measurements showed a weight reduction of 3.70 wt% at 350°C, and the heat resistance to discoloration was 0%. Copolymer B-1 is soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, but gel formation has not been confirmed.

[0141] Comparative Example 2: Synthesis of polysiloxane-modified crosslinked polymer particles (C-1) 45 parts of divinylbenzene (56% purity, the remaining 38% being ethylvinylbenzene and the remaining 6% being impurities, hereinafter referred to as divinylbenzene), 55 parts of styrene, 3 parts of sodium dodecylbenzenesulfonate, 0.5 parts of polyvinyl alcohol, 1000 parts of deionized water, and 0.7 parts of α,α'-azoisobutyronitrile were placed in a reaction vessel and homogenized at 15,000 rpm for 60 minutes using a homogenizer. Nitrogen gas was then introduced and the mixture was heated to 80°C, and stirred continuously for 3 hours to perform suspension polymerization, yielding polymer particles (C-0). Next, while maintaining the reaction vessel temperature at 25°C, the pH was adjusted to 8.0, and 30 parts of methyltriethoxysilane (MTES) were added, followed by vigorous stirring for approximately 30 minutes. Afterward, the reaction vessel was heated to 70°C and allowed to react for 3 hours to terminate the condensation reaction, producing cross-linked polymer particles C-1. No coagulation was observed in this dispersion. The average particle size of the obtained cross-linked polymer particles a was measured to be 1.9 μm. After centrifuging and washing the aqueous slurry of the obtained cross-linked polymer particles, elemental analysis was performed by ESCA, and the presence of Si element was observed.

[0142] Example 2 Synthesis of modified vinyl aromatic copolymer (D-1) 120 ml (93.5 g) of ethylcyclohexane and 0.77 ml (4.0 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were added. At 10 °C, 12.5 ml of a hexane solution containing 1.28 g (20.0 mmol) of n-butyllithium (based on purity) was added. Then, a mixture of 2.12 g of pre-removed DVB-630 (containing 10.0 mmol of divinylbenzene (a mixture of intermediate and para compounds) and 6.26 mmol of ethylvinylbenzene (a mixture of intermediate and para compounds), 1.01 g (9.7 mmol) of styrene, and 7.77 g (114.0 mmol) of isoprene was added to initiate polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 28 °C. After the polymerization reaction was complete, a small sample of the polymerization solution was analyzed by gas chromatography (GC). No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis revealed that at the end of the first polymerization stage, the copolymer's Mn was 1540, Mw was 3570, and Mw / Mn was 2.32. 7.27 g (20.0 mmol) of 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP) was added as a modifier, and the reaction was allowed to proceed for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was complete, 4.72 g (40.0 mmol) of succinic acid was added, and the mixture was stirred and then filtered. The resulting polymerization solution was concentrated by deevaporation and then dissolved in ethylcyclohexane, but no gel or microgel formation was observed. Next, to remove unreacted TESPTADSP, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer, causing it to separate into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by deevaporation and then dissolved in ethylcyclohexane. The result was a yield of 16.70 g (yield: 94.6 wt%) of the modified vinyl aromatic copolymer D-1 on a solids basis. The analytical results of the modified vinyl aromatic copolymer D-1 are shown in Table 1.

[0143] The modified vinyl aromatic copolymer D-1 obtained has a Mn of 1960, a Mw of 5150, and a Mw / Mn ratio of 2.63. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer D-1 contained 6.31 mol% (7.37 wt%) of structural units derived from divinylbenzene, 3.94 mol% (4.61 wt%) of structural units derived from ethylvinylbenzene, 6.14 mol% (5.75 wt%) of structural units derived from styrene, 71.88 mol% (43.98 wt%) of structural units derived from isoprene, and 11.72 mol% (38.29 wt%) of structural units derived from 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP). Each molecule of the modified vinyl aromatic copolymer incorporated 2.06 modifiers. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 5.99 mol% (7.00 wt%), the degree of crosslinking (a1 / a) is 0.95. Furthermore, since the modified vinyl aromatic copolymer (D-1) contains 0.32 mol% (0.37 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.004. Also, 92.9 mol% of the structural units derived from TESPTADSP are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 1.16 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (D-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as a reference sample; the haze value was 0.03. The analytical results of the copolymers of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.

[0144] [Table 1]

[0145] Example 3: Synthesis of Modified Vinyl Aromatic Copolymer (E-1) The first stage of polymerization was initiated by adding 120 ml (93.5 g) of ethylcyclohexane and 0.77 ml (4.0 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane at 50 °C. Then, 12.5 ml of a hexane solution containing 1.28 g (20.0 mmol) of n-butyllithium (based on purity) was added. Following this, a mixture of 2.12 g of pre-removed DVB-630 (containing 10.0 mmol of divinylbenzene (a mixture of intermediate and para compounds) and 6.26 mmol of ethylvinylbenzene (a mixture of intermediate and para compounds)) and 2.89 g (123.7 mmol) of styrene was added. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 68 °C. After the polymerization reaction was complete, a small sample of the polymerization solution was analyzed by gas chromatography (GC). No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis revealed that at the end of the first polymerization stage, the copolymer's Mn was 1650, Mw was 3330, and Mw / Mn was 2.02. 4.09 g (20.0 mmol) of isoprene was added to the reactor as an additional monomer to initiate the second polymerization stage. After the second polymerization stage, a small sample of the polymerization solution was taken for GC analysis. No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. GPC analysis again revealed that at the end of the second polymerization stage, the copolymer's Mn was 1980, Mw was 4200, and Mw / Mn was 2.12. Comparing the GPC dissolution curves of the sample at the end of the first and second polymerization stages showed that the GPC dissolution curves maintained almost the same molecular weight distribution due to the addition of the fourth monomer, isoprene, and shifted towards the higher molecular weight side, confirming that the terminal active species were essentially converted entirely into carboanions derived from isoprene. Therefore, 5.57 g (20.0 mmol) of 3-epoxypropoxypropyltriethoxysilane (GPTES) as shown in formula (3) was added as a modifier. The polymerization reaction was carried out for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was completed, 4.72 g (40.0 mmol) of succinic acid was added, and the mixture was stirred and then filtered. Here, GPTES is a modifier that generates hydroxyl groups by reacting with carbocations with alkoxysilyl groups and epoxypropyl groups as active species simultaneously. The resulting polymerization solution was concentrated by deevaporation and then dissolved in ethylcyclohexane. No gel or microgel formation was observed. Next, to remove unreacted TESPTADSP, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer, causing it to separate into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by deevaporation and then dissolved in ethylcyclohexane. The result was a yield of 23.06 g (93.5 wt%) of the modified vinyl aromatic copolymer E-1 on a solids basis. The analytical results of the modified vinyl aromatic copolymer E-1 are shown in Table 2.

[0146] The modified vinyl aromatic copolymer E-1 had a Mn of 2750, a Mw of 7480, and a Mw / Mn ratio of 2.72. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer E-1 contained 4.56 mol% (5.28 wt%) of structural units derived from divinylbenzene, 2.83 mol% (3.30 wt%) of structural units derived from ethylvinylbenzene, 56.23 mol% (52.26 wt%) of structural units derived from styrene, 27.26 mol% (16.57 wt%) of structural units derived from isoprene, and 9.10 mol% (22.58 wt%) of structural units derived from 3-epoxypropoxypropyltriethoxysilane (GPTES). Each molecule of the modified vinyl aromatic copolymer incorporated 2.23 modifiers. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 4.41 mol% (5.12 wt%), the degree of crosslinking (a1 / a) is 0.97. Furthermore, the modified vinyl aromatic copolymer (E-1) contains 0.14 mol% (0.16 wt%) of divinylbenzene-derived structural units with residual vinyl groups; therefore, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.002. Also, approximately 100 mol% of the structural units derived from GPTES are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 1.03 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (E-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as the reference sample; the haze value was 0.04.

[0147] Synthesis Example 1: Synthesis of a Multifunctional Vinyl Aromatic Copolymer (F-1) 270.03 g of DVB-810 (1.680 mol of divinylbenzene and 0.394 mol of ethylvinylbenzene (a mixture of intermediate and para components)) and 660.49 g (4.226 mol) of diisobutylene (the mixture described below) were added. 210 mmol (24.15 mL) of propyl acetate and 546.15 g (5.927 mmol) of toluene were added to a 3.0 L reactor. 42.0 mmol of boron trifluoride diethyl ether complex (5.28 mL) was added at 70 °C, and the reaction was allowed to proceed for 5.0 hours. After stopping the polymerization reaction with an aqueous sodium bicarbonate solution, the oil layer was washed three times with pure water. The mixture was then subjected to reduced pressure at 60 °C to remove volatilization, dissolved in toluene, and the polymer was reprecipitated with methanol. The precipitate was then filtered and dried to recover the copolymer, yielding 281.1 g of the polyfunctional vinyl aromatic copolymer F-1.

[0148] The resulting multifunctional vinyl aromatic copolymer (F-1) had a Mn of 1040, a Mw of 3310, and a Mw / Mn ratio of 3.19. 13C-NMR and 1H-NMR analyses confirmed that the multifunctional vinyl aromatic copolymer (F-1) contained 45.2 mol% (48.4 wt%) of structural units derived from divinylbenzene, 7.7 mol% (8.3 wt%) of structural units derived from ethylvinylbenzene, and 47.0 mol% (43.3 wt%) of structural units derived from diisobutylene. Since the crosslinking structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) was 19.4 mol% (20.8 wt%), the degree of crosslinking (a1 / a) was 0.43. Furthermore, since the polyfunctional vinyl aromatic copolymer (F-1) contains 25.8 moles (27.6 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mole fraction of vinyl-containing structural units (a2) relative to the sum of structural units derived from divinylbenzene, structural units derived from ethylvinylbenzene, and structural units derived from diisobutylene is 0.276. Furthermore, the TMA measurement results of the hardened material showed a Tg of 188℃ and a softening temperature above 280℃. Thermogravimetric analysis (TGA) showed a weight loss of 1.51 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of a multifunctional vinyl aromatic copolymer (F-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as a reference sample; the haze value was 0.04.

[0149] Example 4 Synthesis of modified vinyl aromatic copolymer (G-1) The reactor was filled with 160 ml (124.6 g) of ethylcyclohexane and 0.61 ml (4.0 mmol) of N,N,N',N'-tetramethylethylenediamine. At 50°C, 12.5 ml of a hexane solution containing 1.28 g (20.0 mmol) of n-butyllithium (purity) was added. Then, a solution containing 4.66 g of the pre-dried polyfunctional vinyl aromatic copolymer (F-1) synthesized in Synthetic Example 1 dissolved in 40 ml (31.2 g) of ethylcyclohexane was added to begin the first stage of polyfunctional initiator synthesis. After the initial reaction, a solution containing 16.36 g (80.0 mmol) of isoprene (as a monomer) dissolved in 40 ml (31.2 g) of ethylcyclohexane was added to the reactor to begin the second stage of polymerization. After the second stage of polymerization, a small sample of the polymerization solution was taken for GC analysis. No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis revealed that at the end of the second polymerization stage, the copolymer's Mn was 2830, Mw was 8450, and Mw / Mn was 2.99. Comparing the GPC dissolution curves of the sample at the end of the first stage of reaction with those at the end of the second stage of polymerization, the results showed that the GPC dissolution curves maintained almost the same molecular weight distribution due to the addition of the fourth monomer, isoprene, and shifted to the high molecular weight side, confirming that the terminal active species were essentially converted entirely into carboanions derived from isoprene. Therefore, a solution prepared by dissolving 7.27 g (20.0 mmol) of 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP) in 40 ml (31.2 g) of ethylcyclohexane was added as a modifier, and the mixture was subjected to a modification reaction for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was completed, 4.72 g (40.0 mmol) of succinic acid was added, and the mixture was stirred and then filtered. The resulting polymerization solution was concentrated by deevaporation and then dissolved in ethylcyclohexane. No gel or microgel formation was observed. Next, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer to remove unreacted TESPTADSP, causing separation into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by deevaporation and then dissolved in ethylcyclohexane. The result was a yield of 16.34 g (94.0 wt%) of the modified vinyl aromatic copolymer G-1 on a solids basis. The analytical results of the modified vinyl aromatic copolymer G-1 are shown in Table 2.

[0150] The resulting modified vinyl aromatic copolymer G-1 has a Mn of 3350, a Mw of 12200, and a Mw / Mn ratio of 3.64. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer G-1 contained 12.76 mol% (13.70 wt%) of structural units derived from divinylbenzene, 2.18 mol% (2.34 wt%) of structural units derived from ethylvinylbenzene, 13.26 mol% (12.27 wt%) of structural units derived from diisobutylene, 58.93 mol% (33.10 wt%) of structural units derived from isoprene, and 12.87 mol% (38.59 wt%) of structural units derived from 1-(3-triethoxysilylpropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilylcyclopentane (TESPTADSP). Each molecule of the modified vinyl aromatic copolymer incorporated 3.86 modifiers. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 12.38% (13.29 wt%), the degree of crosslinking (a1 / a) is 0.97. Furthermore, since the modified vinyl aromatic copolymer (G-1) contains 0.38 mol% (0.41 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.025. Also, approximately 100 mol% of the structural units derived from TESPTADSP are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 1.47 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (G-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as a reference sample; the haze value was 0.03.

[0151] Example 5 Synthesis of modified vinyl aromatic copolymer (H-1) The polymerization process was initiated by adding 120 ml (93.5 g) of ethylcyclohexane and 0.77 ml (4.0 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane at 50 °C. Then, 12.5 ml of a hexane solution containing 1.28 g (20.0 mmol) of n-butyllithium (based on purity) was added. Following this, a mixture of 2.24 g of pre-removed DVB-630 (containing 10.6 mmol of divinylbenzene (a mixture of intermediate and para compounds) and 6.63 mmol of ethylvinylbenzene (a mixture of intermediate and para compounds)) and 12.79 g (122.8 mmol) of styrene was added to begin the first stage of polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 73 °C. After the polymerization reaction was complete, a small sample of the polymerization solution was analyzed by gas chromatography (GC). No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis revealed that at the end of the first polymerization stage, the copolymer's Mn was 2080, Mw was 4390, and Mw / Mn was 2.11. 9.54 g (140.0 mmol) of isoprene was added to the reactor as an additional monomer to initiate the second polymerization stage. After the second polymerization stage, a small sample of the polymerization solution was taken for GC analysis. No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. GPC analysis again revealed that at the end of the second polymerization stage, the copolymer's Mn was 2910, Mw was 6630, and Mw / Mn was 2.28. Comparing the GPC dissolution curves of the sample at the end of the first and second polymerization stages showed that the GPC dissolution curves maintained almost the same molecular weight distribution due to the addition of isoprene as an additional monomer, and shifted towards the higher molecular weight side, confirming that the terminal active species were essentially converted entirely into carboanions derived from isoprene. Therefore, 5.65 g (20.0 mmol) of 3-epoxypropoxypropyltriethoxysilane (GPTES) was added as a modifier, and the modification reaction was carried out for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was completed, 4.72 g (40.0 mmol) of succinic acid was added, stirred, and then filtered. The resulting polymerization solution was concentrated by deevaporation and then dissolved in ethylcyclohexane. No gel or microgel formation was observed. Next, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer to remove unreacted GPTES, causing separation into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by deevaporation and then dissolved in ethylcyclohexane. The result was a yield of 29.00 g (yield: 96.0 wt%) of the modified vinyl aromatic copolymer H-1, based on solids. The analytical results of the modified vinyl aromatic copolymer H-1 are shown in Table 2.

[0152] The modified vinyl aromatic copolymer H-1 had a Mn of 3470, a Mw of 9260, and a Mw / Mn ratio of 2.67. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer H-1 contained 3.53 mol% (4.68 wt%) of structural units derived from divinylbenzene, 2.21 mol% (2.93 wt%) of structural units derived from ethylvinylbenzene, 40.88 mol% (43.35 wt%) of structural units derived from styrene, 46.62 mol% (32.33 wt%) of structural units derived from isoprene, and 6.76 mol% (16.71 wt%) of structural units derived from 3-epoxypropoxypropyltriethoxysilane (GPTES). Each molecule of the modified vinyl aromatic copolymer incorporated 2.33 modifiers. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 3.39 mol% (4.49 wt%), the degree of crosslinking (a1 / a) is 0.96. Furthermore, since the modified vinyl aromatic copolymer (H-1) contains 0.14 mol% (0.19 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.0015. Also, approximately 100 mol% of the structural units derived from GPTES are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 1.17 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (H-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as a reference sample; the haze value was 0.04.

[0153] [Table 2]

[0154] Example 6 Synthesis of modified vinyl aromatic copolymer (I-1) 120 ml (93.5 g) of ethylcyclohexane and 0.77 ml (4.0 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were added, and 12.5 ml of a hexane solution containing 2.14 g (20.0 mmol) of lithium diisopropylamine (LDIPA) as shown in formula (4) was added at 50 °C as a polymerization initiator. Then, a mixture of 2.24 g of pre-removed impurity DVB-630 (10.6 mmol of divinylbenzene (a mixture of intermediate and para compounds) and 6.63 mmol of ethylvinylbenzene (a mixture of intermediate and para compounds)) and 12.79 g (122.8 mmol) of styrene was added to initiate the first stage of polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 77°C. After the polymerization reaction was completed, a small sample of the polymerization solution was taken and analyzed by gas chromatography (GC). No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Furthermore, GPC analysis showed that at the end of the first stage of polymerization, the copolymer had a Mn of 2010, a Mw of 3780, and a Mw / Mn ratio of 1.98. Then, 9.54 g (140.0 mmol) of isoprene was added to the reactor as an additional monomer to initiate the second stage of polymerization. After the second stage of polymerization, a small sample of the polymerization solution was taken for GC analysis. No unreacted monomers were observed, confirming that the polymerization conversion was almost 100%. Further GPC analysis showed that at the end of the second stage of polymerization, the copolymer's Mn was 3020, Mw was 6730, and Mw / Mn was 2.23. Comparing the GPC dissolution curves of the sample at the end of the first and second stage polymerizations, the results showed that the GPC dissolution curves maintained almost the same molecular weight distribution due to the addition of the fourth monomer, isoprene, and shifted to the high molecular weight side, confirming that the terminal active species were essentially converted entirely into carboanions derived from isoprene. Therefore, 5.65 g (20.0 mmol) of 3-epoxypropoxypropyltriethoxysilane (GPTES) was added as a modifier, and the modification reaction was carried out for 2 hours to obtain a polymer solution containing the modified vinyl aromatic copolymer. After the polymerization reaction was completed, 4.72 g (40.0 mmol) of succinic acid was added, stirred, and then filtered. The resulting polymerization solution was concentrated by deevaporation and then dissolved in ethylcyclohexane. No gel or microgel formation was observed. Next, to remove unreacted GPTES, methanol was added to the ethylcyclohexane solution of the modified vinyl aromatic copolymer, causing it to separate into two layers. After removing the methanol-soluble components, the ethylcyclohexane solution containing the modified vinyl aromatic copolymer was concentrated by deevaporation and then dissolved in ethylcyclohexane. The result was a yield of 30.35 g (yield: 94.2 wt%) of the modified vinyl aromatic copolymer I-1, based on solids. The analytical results of the modified vinyl aromatic copolymer I-1 are shown in Table 3.

[0155] The modified vinyl aromatic copolymer I-1 had a Mn of 3630, a Mw of 10090, and a Mw / Mn ratio of 2.78. GC, 13C-NMR, and 1H-NMR analyses confirmed that the modified vinyl aromatic copolymer I-1 contained 3.31 mol% (4.38 wt%) of structural units derived from divinylbenzene, 2.07 mol% (2.74 wt%) of structural units derived from ethylvinylbenzene, 40.59 mol% (38.33 wt%) of structural units derived from styrene, 43.71 mol% (30.28 wt%) of structural units derived from isoprene, and 6.33 mol% (15.65 wt%) of structural units derived from 3-epoxypropoxypropyltriethoxysilane (GPTES). Each molecule of the modified vinyl aromatic copolymer incorporated 2.33 modifiers. Since the crosslinked structural unit (a1) derived from the divinyl aromatic compound represented by formula (1) is 3.21 mol% (4.25 wt%), the degree of crosslinking (a1 / a) is 0.97. Furthermore, since the modified vinyl aromatic copolymer (I-1) contains 0.10 mol% (0.13 wt%) of divinylbenzene-derived structural units with residual vinyl groups, the mol fraction of the vinyl-containing structural unit (a2) relative to the sum of structural units (a) and (b) is 0.0011. Also, approximately 100 mol% of the structural units derived from GPTES are bonded to structural units derived from isoprene. Thermogravimetric analysis (TGA) showed a weight loss of 1.21 wt% at 350°C (TGA350). A sample prepared by dissolving 0.5 g of the modified vinyl aromatic copolymer (I-1) in 100 g of toluene was placed in a quartz cuvette. The haze (turbidity) was measured using an integrating sphere transmittance meter with toluene as the reference sample; the haze value was 0.05.

[0156] [Table 3]

[0157] Example 7 Synthesis of modified conjugated diene copolymer (A-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were added. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (based on purity) was added, followed by 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 78°C. After polymerization, 15 g of a cyclohexane solution containing 0.527 g of the modified vinyl aromatic copolymer (A-1) obtained in Example 1 was added as an SBR modifier to modify the resulting styrene-butadiene rubber (SBR). The modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer (modified SBR) A-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer A-2 are shown in Table 4.

[0158] Comparative Example 3: Synthesis of Modified Conjugated Diene Copolymer (B-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 79°C. After polymerization, 15 g of a cyclohexane solution containing 0.379 g of the modified vinyl aromatic copolymer (B-1) obtained in Comparative Example 1 was added as an SBR modifier to carry out a modification reaction. The modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer B-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) B-2 are shown in Table 4.

[0159] Comparative Example 4: Synthesis of Modified Conjugated Diene Copolymer (C-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (purity based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 79°C. After polymerization, 15 g of a cyclohexane solution containing 0.466 g of the modified vinyl aromatic copolymer (C-1) obtained in Comparative Example 2 was added as an SBR modifier to carry out a modification reaction. The modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer C-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) C-2 are shown in Table 4.

[0160] Example 8 Synthesis of modified conjugated diene copolymer (D-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (purity based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 81°C. After polymerization, 15 g of a cyclohexane solution containing 0.363 g of the modified vinyl aromatic copolymer (D-1) obtained in Example 2 was added as an SBR modifier to modify the resulting styrene-butadiene rubber (SBR), and a modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer D-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) D-2 are shown in Table 4.

[0161] Example 9 Synthesis of modified conjugated diene copolymer (E-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (purity based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 81°C. After polymerization, 15 g of a cyclohexane solution containing 0.493 g of the modified vinyl aromatic copolymer (E-1) obtained in Example 3 was added as an SBR modifier to modify the resulting styrene-butadiene rubber (SBR), and a modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer E-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) E-2 are shown in Table 5.

[0162] Example 10 Synthesis of modified conjugated diene copolymer (G-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (purity based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 81°C. After polymerization, 15 g of a cyclohexane solution containing 0.348 g of the modified vinyl aromatic copolymer (G-1) obtained in Example 4 was added as an SBR modifier to modify the resulting styrene-butadiene rubber (SBR), and a modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer G-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) G-2 are shown in Table 5.

[0163] Example 11 Synthesis of modified conjugated diene copolymer (H-2) In a nitrogen-substituted autoclave reactor, 580 g of cyclohexane and 5 g of a cyclohexane solution containing 30.7 mg (0.16 mmol) of 2,2-bis(2-tetrahydrofuranyl)propane were charged. At 50°C, 15 g of a cyclohexane solution containing 51.2 mg (0.80 mmol) of n-butyllithium (purity based on purity) was added, followed by the addition of 34.29 g of pre-removed styrene and 80.00 g of 1,3-butadiene, initiating polymerization. The temperature of the reaction solution rose due to the heat of polymerization, reaching a maximum of 81°C. After polymerization, 15 g of a cyclohexane solution containing 0.596 g of the modified vinyl aromatic copolymer (H-1) obtained in Example 5 was added as an SBR modifier to modify the resulting styrene-butadiene rubber (SBR), and a modification reaction was carried out at 60°C for 30 minutes to obtain a polymer solution. Further addition of 0.40 mmol of bis(3-trimethoxysilylpropyl)methylamine and allowing it to undergo a modification reaction for 30 minutes yielded a polymer solution containing the modified conjugated diene copolymer. After adding 0.045 g of 2,6-di-tert-4-hydroxytoluene as an antioxidant to the obtained polymerization solution, the solvent was removed by steam stripping, and the modified conjugated diene copolymer H-2 was obtained by vacuum drying. The analytical results of the modified conjugated diene copolymer (modified SBR) H-2 are shown in Table 5.

[0164] [Table 4]

[0165] [Table 5]

[0166] Example 12 The modified conjugated diene copolymer (modified SBR) A-2 obtained in Example 7, processing oil, carbon black, zinc oxide, stearic acid and anti-aging agent were mixed at 155°C and 60 rpm for 4 minutes using a Labo Plastomill. Sulfur and a vulcanization accelerator were added to the obtained mixture, and vulcanization was carried out using a Labo Plastomill at 70°C and 60 rpm for 1 minute to obtain crosslinked rubber A-3. The blending ratios of each additive are shown in Table 6, and the physical properties of the resulting cross-linked rubber are shown in Table 7.

[0167] [Table 6]

[0168] In addition, the following additives were used. Silicon dioxide: Manufactured by Evonik Degussa, ULTRASIL 7000 Carbon Black: Niteron #200IS (New Daily Chemicals Carbon Products) Zinc oxide: Sakai Chemical produces two types of zinc oxide. Stearic acid: manufactured by FUJIFILM Wako Pure Chemical Anti-aging agent: NOCRAC 6C manufactured by Dainei New Chemical Industry Sulfur: Tsurumi Chemical Industry produces powdered sulfur in two JIS grades. Vulcanization accelerator A: Nocceler CZ-G manufactured by Daichi Shinshin Chemical Industry Co., Ltd. Vulcanization accelerator B: Nocceler DP manufactured by Ouchi Shinshin Chemical Industry Co., Ltd.

[0169] Examples 13 and 14, Comparative Examples 5 and 6 Except for using the modified conjugated diene copolymers (modified SBR) B-2, C-2, D-2 and G-2 synthesized in Examples 8, 10 or Comparative Examples 3 and 4 to replace the modified conjugated diene copolymer (modified SBR) A-2, crosslinked rubbers B-3, C-3, D-3 and G-3 were obtained in the same manner as in Example 12. The physical properties of the resulting cross-linked rubber are shown in Table 7.

[0170] [Table 7]

[0171] According to Table 7, it can be seen that the crosslinked rubber using the modified conjugated diene copolymer (modified SBR) of the example has a better binding rubber index than the comparative example, thus improving the dispersibility of inorganic fillers and loss during travel. It has excellent tensile strength and abrasion resistance and helps to make it a material with both strength and abrasion resistance. [Industry availability]

[0172] The modified vinyl aromatic copolymers of the present invention are particularly useful as modifiers for conjugated diene copolymers (SBR, etc.). The cross-linked rubber fillers formed by cross-linking fillers in the obtained modified conjugated diene copolymers (modified SBR, etc.) exhibit excellent dispersibility, mechanical strength, and abrasion resistance, and therefore can be used as elastomer materials such as tires (treads), shock-absorbing rubbers, rubber hoses, rubber rollers, and footwear materials. The modified vinyl aromatic copolymers of this invention can be used in the electrical / electronics industry, aerospace industry, and construction industry as dielectric materials, insulating materials, heat-resistant materials, structural materials, adhesives, fillers, coatings, coating agents, sealants, printing inks, dispersants, etc., suitable for low-dielectric substrates. The curable resin composition can also be processed into films, sheets, and prepregs for use in plastic optical parts, touch panels, flat panel displays, thin-film liquid crystal elements, and further applied to various optical components, primarily optical waveguides and optical lenses. It can also be used as a modifier to improve the heat resistance, dielectric properties, adhesion / sealing properties, and optical properties of thermoplastic or curable resin compositions.

Claims

1. A modified vinyl aromatic copolymer comprising structural units (a) derived from a divinyl aromatic compound, structural units (b) derived from a monovinyl aromatic compound, and structural units (c) derived from a conjugated diene compound, wherein, 95 mol% or more of the structural unit (a) is a cross-linked structural unit (a1) represented by the following formula (1): (1) Here, R1 represents an aromatic hydrocarbon group with 6 to 30 carbon atoms; The modified vinyl aromatic copolymer is modified by at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups and hydroxyl groups, with an average number of functional groups of 2.0 to 5.0 per molecule, and the aforementioned functional groups are modified by being bonded to structural unit (c) derived from a conjugated diene compound, with a number average molecular weight Mn of 500 to 30,000.

2. The modified vinyl aromatic copolymer as claimed in claim 1, comprising 0.5 mol% to 45.0 mol% of structural units derived from divinyl aromatic compounds (a), 0.5 mol% to 99.0 mol% of structural units derived from monovinyl aromatic compounds (b), and 0.5 mol% to 99.0 mol% of structural units derived from conjugated diene compounds (c).

3. The modified vinyl aromatic copolymer as described in claim 1, wherein, The molecular weight distribution (Mw / Mn), expressed as the ratio of weight average molecular weight Mw to number average molecular weight Mn, is less than 10.

0.

4. The modified vinyl aromatic copolymer as described in claim 1, wherein, The average number of functional groups in each molecule ranges from 2 to 20.

5. The modified vinyl aromatic copolymer as described in claim 1, wherein, Monovinyl aromatic compounds are selected from one or more monomers in the group consisting of styrene, vinylnaphthalene, vinylbiphenyl, m-methylstyrene, p-methylstyrene, o-, p-dimethylstyrene, m-ethylvinylbenzene, indene, and p-ethylvinylbenzene.

6. A method for manufacturing a modified vinyl aromatic copolymer, comprising the method described in any one of claims 1 to 5, the method comprising: a polymerization step, using an alkali metal compound or an alkaline earth metal compound as an anionic polymerization initiator to copolymerize a divinyl aromatic compound, a monovinyl aromatic compound, and a conjugated diene compound to obtain a vinyl aromatic copolymer having a branched structure and active ends; and an end modification step, reacting a compound having at least one functional group selected from the group consisting of amino groups, alkoxysilyl groups, and hydroxyl groups, or such precursor compounds, with the active ends of the aforementioned vinyl aromatic copolymer to form functional groups.

7. A modified conjugated diene copolymer obtained by reacting a modified vinyl aromatic copolymer as described in any one of claims 1 to 5 with a polymer of a conjugated diene compound or a copolymer of a conjugated diene compound with an aromatic vinyl compound.

8. The modified conjugated diene copolymer as claimed in claim 7, comprising 0.001 to 6% by weight of structural units (A1) derived from the modified vinyl aromatic copolymer, 29 to 99.999% by weight of structural units (B1) derived from the conjugated diene compound, and 0 to 70% by weight of structural units (C1) derived from the aromatic vinyl compound.

9. The modified conjugated diene copolymer as described in claim 7, wherein, In the differential molecular weight distribution curve obtained by gel permeation chromatography (GPC), when the total area is set to 100%, the area of ​​the region with a number average molecular weight (Mn) that is more than three times the peak value of the lowest molecular weight side is more than 10%.

10. A resin composition comprising, relative to 100 parts by weight of the modified conjugated diene copolymer as described in claim 7, 0.5 to 200 parts by weight of at least one reinforcing filler selected from the group consisting of silica-based inorganic fillers, metal oxides, metal hydroxides and carbon black.

11. The resin composition as described in claim 10, further comprising a crosslinking agent.

12. A resin crosslinker formed by crosslinking a resin composition as described in claim 11.

13. A structural member comprising a resin crosslinker as described in claim 12.

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