JP2006096907A - Reinforcing particle, polymer composition, method for producing the same and vulcanizable rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer composition having excellent mechanical strength, low heat buildup properties and abrasion resistance, to provide a reinforcing particle suitable for affording the polymer composition, to provide a method for producing the same and to provide a vulcanizable rubber composition comprising the polymer composition. <P>SOLUTION: The reinforcing particle is obtained by coating a reinforcing particle having silanol groups on the surface with a functional group-containing siloxane compound represented by general formula (I) (wherein, R<SP>1</SP>to R<SP>4</SP>denote each a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom of the periodic table or a 1-20C hydrocarbon group which may have a halogen atom or the polar functional group; at least one of R<SP>1</SP>to R<SP>4</SP>denotes a halogen atom or the polar functional group or a 1-20C hydrocarbon group having the polar functional group; R<SP>2</SP>and R<SP>3</SP>may each be the same or different; and n denotes an integer of 1-20,000). The polymer composition comprises the reinforcing particle. The vulcanizable rubber composition is obtained by compounding the polymer composition with a vulcanizing agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to reinforcing particles having a specific structure, a polymer composition containing the same, a production method thereof, and a vulcanizable rubber composition. More specifically, the reinforcing particles formed by coating with a compound having a specific structure, and the polymer composition containing the reinforcing particles having excellent dispersibility of the reinforcing particles and excellent mechanical properties and wear resistance. The present invention relates to a product, a production method thereof, and a vulcanizable rubber composition containing the polymer composition and a vulcanizing agent.

In recent years, with the emphasis on resource saving and environmental measures, the demand for lower fuel consumption of automobiles has become stricter, and automobile tires can contribute to lower fuel consumption by reducing rolling resistance. It has been demanded.
For this reason, it replaces with conventional carbon black as a reinforcing agent, and it is performed. When silica is added to the tire rubber composition, the low heat build-up property is improved and rolling resistance is reduced, and the wet performance of the tire is improved. However, since silica has a lower affinity for rubber molecules than carbon black, it has a problem of poor dispersibility in rubber and is inferior in the effect of improving fracture resistance and abrasion resistance (reinforcing property). there were. Therefore, in order to obtain a reinforcing property equivalent to that of carbon black, a silane coupling agent is generally used in combination when silica is compounded in the rubber composition.
However, the silane coupling agent alone is not sufficient in the dispersibility and reinforcement of silica.

  For this reason, in order to improve this, methods for modifying the surface of silica with various hydrophobic compounds have been studied. As such a compound, there is a sulfur-containing silane coupling agent such as a silyl group-containing sulfide compound, but a large amount of use is necessary and it is not economical.

  Patent Document 1 includes a rubber composition containing a diene rubber and silica and a silicone oil having a polar group at a side chain or a terminal, and is excellent in rebound resilience, tensile properties, wear properties, and processing properties. Has been reported to be obtained. However, performance such as low fuel consumption is still insufficient.

  Patent Document 2 discloses a functionalized polyorganosiloxane compound containing at least one functional siloxy group unit capable of binding to at least one elastomer and silica as a reinforcing filler to a hydroxyl site on the surface of silica particles, and polyorganosiloxane. A rubber composition for a tire casing containing a functionalized organosilane having a functional group capable of binding to a compound and / or silica particles and a functional group capable of binding to a polymer has improved hysteresis characteristics and scorch stability. Then, it is reported. However, in order to obtain a desired effect, it is necessary to synthesize a functionalized organosilane that requires a cumbersome process.

In Patent Document 3, silica is surface-treated by dipping or coating with a polysiloxane having an alkoxysilyl group or an acyloxysilyl group, preferably in a solvent such as acetone, methanol, ethanol, etc. in the presence of a titanium catalyst, and then dried. A rubber composition comprising the polysiloxane surface-treated metal oxide thus obtained is disclosed, and this rubber composition is reported to have improved modulus and abrasion resistance.
However, since the silica surface-treated with these silicone oils and siloxanes does not have a reactive site with rubber, there is a report that the effect is not sufficient from the viewpoint of reinforcement (Patent Document 4).

  Patent Document 4 discloses a rubber reactive polysiloxane obtained by hydrolyzing and condensing a linear or branched polysiloxane with a functional group capable of reacting with a diene rubber and a metal oxide such as silica. , Preferably a rubber-reactive polysiloxane surface-treated metal oxide, which is surface-treated by a dry method using a titanium catalyst, a diene rubber, the rubber-reactive polysiloxane surface-treated metal oxide, and a sulfur-containing silane coupling. A rubber composition comprising an agent is disclosed. According to the description of the publication, this rubber composition is said to have high breaking strength and breaking elongation. However, this rubber composition does not have sufficient performance in terms of wear resistance and low fuel consumption.

  Recently, rubber latex is added to and mixed with an aqueous suspension containing silica, polysiloxane and a nonionic surfactant, then the rubber is coagulated with acid and dried to form rubber powder or rubber granules. A manufacturing method has been proposed (Patent Document 5). According to this method, a certain improvement is seen in workability, fuel efficiency and wear, but it is not sufficient.

  Thus, when silica is compounded as reinforcing particles, extensive research has been conducted to obtain a rubber composition that exhibits excellent workability, mechanical strength, and high wear resistance, and is also excellent in fuel efficiency. Despite this, it cannot be said that there is still a product that meets these requirements.

  As described above, various compounding agents are added to improve various properties without impairing the original properties of the polymer as the base material. In these cases, the dispersibility of the compounding agent is good. In addition, it is required that the good properties inherent to the base polymer are maintained even in the base polymer / compounding agent composite.

International Publication No. 96/29364 Pamphlet Japanese Patent Laid-Open No. 9-194638 Japanese Patent Laid-Open No. 10-25364 JP 2004-67818 A JP 2003-160668 A

  Therefore, an object of the present invention is to provide a polymer composition excellent in dispersibility of reinforcing particles and inherent in the base polymer, particularly in mechanical strength and wear resistance, and a method for producing the same. It is in. Another object of the present invention is to provide reinforcing particles suitable for obtaining the polymer composition and a method for producing the same. Still another object of the present invention is to provide a vulcanizable rubber composition having excellent mechanical strength and wear resistance.

  As a result of intensive studies in order to solve the above problems, the present inventor has found that a polymer containing reinforcing particles such as silica and a polymer coated with a specific functional group-containing siloxane compound in a specific solvent. As a result of finding out that the combined composition is excellent in each of the above-mentioned properties and further diligently researching based on this finding, the present invention has been completed.

Thus, according to the present invention, 100 parts by weight of reinforcing particles having silanol groups on the surface are represented by the following general formula (I) in an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2. The functional group-containing siloxane compound-coated reinforcing particles obtained by coating with 0.3 to 200 parts by weight of the functional group-containing siloxane compound are provided.

In the general formula (I), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or the polar functional group And a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group, or the carbon number having the polar functional group 1 to 20 hydrocarbon groups. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000.
The functional group-containing siloxane compound reinforcing particles of the present invention are those in which at least one of R ² and R ³ has at least one polyoxyalkylene group in the functional group-containing siloxane compound represented by the general formula (I). Preferably there is.
In the present invention, the functional group-containing siloxane compound-coated reinforcing particles may have a form of a solution of an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 .

According to the present invention, 100 parts by weight of reinforcing particles having a silanol group on the surface are added to the functional group represented by the general formula (I) in an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2. There is provided a method for producing functional group-containing siloxane compound-coated reinforcing particles, which is mixed with 0.3 to 200 parts by weight of a group-containing siloxane compound.

In the general formula (I), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or the polar functional group And a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group, or the carbon number having the polar functional group 1 to 20 hydrocarbon groups. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000.

The present invention also provides a polymer composition comprising 100 parts by weight of a base polymer and 5 to 200 parts by weight of the functional group-containing siloxane compound-coated reinforcing particles.
In the polymer composition of the present invention, the base polymer preferably contains a structure represented by the general formula (II) in the molecule.

In the general formula (II), R ⁵ and R ⁶ may each have a hydrogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a functional group having the above polarity. It is a good hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ⁵ and R ⁶ has at least one polar functional group. A plurality of R ⁵ and R ⁶ may be the same or different. m is an integer of 2 to 20,000.
The base polymer can also be a rubbery polymer.

According to this invention, the manufacturing method of the polymer composition which mix | blends the said functional group containing siloxane compound covering reinforcing particle with a base polymer is provided.
In the method for producing a polymer composition of the present invention, functional group-containing siloxane compound-coated reinforcing particles having the form of a solution of an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 , and a base polymer Is preferably mixed with an organic solvent having a solubility parameter of 10.0 to 18.8 MPa ^1/2 .

Furthermore, according to the present invention, there is provided a vulcanizable rubber composition comprising the polymer composition using a rubber-like polymer as a base polymer and a vulcanizing agent.
The vulcanizable rubber composition of the present invention is suitable for tires.

  According to the present invention, a polymer composition excellent in dispersibility of reinforcing particles and inherent in the base polymer, particularly in mechanical strength and wear resistance, and reinforcing particles used therefor can be easily obtained. Can get to.

The functional group-containing siloxane compound-coated reinforcing particles of the present invention are formed by coating reinforcing particles with a specific functional group-containing siloxane compound.
The reinforcing particles that can be used in the present invention are those used for imparting reinforcing properties to the polymer particles, and are not particularly limited as long as they have a silanol group on the surface. Mention may be made of siliceous particles.
Examples of the siliceous particles include dry silica, wet silica, synthetic silicate silica such as aluminum silicate and calcium silicate, and the like. Among these, wet-process silica containing hydrous silicic acid as a main component is particularly preferable.
Other specific examples of the reinforcing particles include those having a silanol group on the surface obtained by a method such as reacting the surface of carbon black, talc, calcium carbonate, aluminum hydroxide or the like with a silane compound. it can.
These reinforcing particles can be used alone or in combination of two or more.

Although there is no restriction | limiting in particular in the specific surface area of a siliceous particle, The nitrogen adsorption specific surface area by BET method is 50-800 m < ² > / g. Nitrogen adsorption specific surface area is preferably 80~250m ² / g, more preferably 100 to 200 m ² / g. When the specific surface area is within this range, a polymer composition having particularly excellent workability, low heat build-up, and abrasion resistance can be obtained. The pH of the siliceous particles is not particularly limited, but acidic siliceous particles are preferable, those having a pH of 3 to 6.9 are preferable, and those having a pH of 5 to 6.7 are more preferable.

  In the present invention, the functional group-containing siloxane compound for coating reinforcing particles having silanol groups on the surface is represented by the general formula (I).

In the general formula (I), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or the polar functional group And a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group, or the carbon number having the polar functional group 1 to 20 hydrocarbon groups. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000. The lower limit of n is preferably 3, more preferably 50, and the upper limit is preferably 1,000, more preferably 500.

The number of functional groups in the functional group-containing siloxane compound represented by the general formula (I) (hereinafter sometimes simply referred to as “siloxane compound (I)”) is preferably 3 or more, more preferably 1 molecule. Is 5 or more, more preferably 10 or more. The higher the functional group density, the better the reaction efficiency with the reinforcing particles.
In the siloxane compound (I), the distribution state of the functional group is not particularly limited, and may be randomly distributed or concentrated in a block shape, and the distribution is inclined along the main chain of the siloxane compound. You may do it.

The polar functional group having a group 15 or group 16 atom in the periodic table preferably has an oxygen atom or a nitrogen atom, and more preferably has an oxygen atom.
Specific examples of the polar functional group having a nitrogen atom include an amino group.
Specific examples of the polar functional group having an oxygen atom include those represented by general formula (III): —R ⁷ —O—R ⁸ .
In the general formula (III), R ⁷ is a single bond or a divalent organic group. Examples of the divalent organic group include an alkylene group, a cycloalkylene group, an oxyalkylene group, a polyoxyalkylene group, an arylene group, an ether group, a carbonyl group, and a divalent group formed by a bond thereof (an oxycarbonyl group, Carbonyloxy group and the like).
R ⁸ is a hydrogen atom or a hydrocarbon group. In the hydrocarbon group, part of the carbon atoms may be substituted with a group 15 or group 16 atom such as oxygen, nitrogen, sulfur or the like. These hydrocarbon groups may be a chain, a ring, or a chain partially having a ring. Specific examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an epoxy group, a glycidyl group, and a furyl group. In these hydrocarbon groups, the hydrogen atom may be substituted with a substituent such as halogen.
Specific examples of such polar groups include a hydroxyl group, an alkoxyl group, an aryloxy group, an acyloxy group, an alkoxyalkyl group, a hydroxypolyoxyalkylene group, an alkoxypolyoxyalkylene group, a glycidyloxy group, a carboxyl group, an alkoxycarbonyl group, An aryloxycarbonyl group etc. can be mentioned.

Further, R ⁷ and R ⁸ may be bonded to each other to form a ring containing an oxygen atom. Examples of the polar functional group in which R ⁷ and R ⁸ are bonded to each other to form a ring containing an oxygen atom include an epoxy group and a glycidyl group.

In the siloxane compound (I), it is preferable that at least one of R ² and R ³ has at least one of an epoxy group, a glycidyl group, and a polyoxyalkylene group among these polar functional groups. Among them, it is preferable to have at least one polyoxyalkylene group. Of the polyoxyalkylene groups, hydroxypolyoxyalkylene groups (polyoxyalkylene groups having a hydroxyl group at the terminal) and alkoxy polyoxyalkylene groups (polyoxyalkylene groups having an alkoxyl group at the terminal) are particularly preferred.
The number of oxyalkylene groups in the polyoxyalkylene group is usually 2-20.

  The polar functional group having an atom of Group 15 or Group 16 of the periodic table may be directly bonded to the silicon atom of the skeleton of the siloxane compound (I), and at least one divalent organic group ( An alkylene group, a cycloalkylene group, an arylene group, an amino group, a thioether group, a silylene group, or the like).

  The siloxane compound (I) is a functional group such as a reaction between a polysiloxane having a silanol group at its terminal and an alkoxysilane, a reaction between a Si-H group-containing polysiloxane and an alkoxysilane, an epoxy group, an amino group, a mercapto group, or a carboxyl group. It can be synthesized by a known method such as a reaction between a polysiloxane having a group at a side chain or a terminal and various silane coupling agents.

  The weight average molecular weight of the siloxane compound (I) is preferably 10,000 to 3,000,000, more preferably 50,000 to 1,000,000. When the weight average molecular weight is within this range, the siloxane compound (I) is not lost outside the system during the treatment such as coating of reinforcing particles and blending with the base polymer. Further, when the weight average molecular weight is within this range, it is sufficiently dissolved in the solvent, so that there are advantages such as that it does not take time to coat the reinforcing particles and the coverage of the reinforcing particles can be increased.

The functional group-containing siloxane compound-coated reinforcing particles of the present invention have a general formula of 100 parts by weight of reinforcing particles having silanol groups on the surface in an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2. It can be obtained by mixing with 0.3 to 200 parts by weight of the functional group-containing siloxane compound represented by (I).

In the general formula (I), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or the polar functional group And a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group, or the carbon number having the polar functional group 1 to 20 hydrocarbon groups. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000.

The mixing of the reinforcing particles having a silanol group on the surface and the polar functional group-containing siloxane compound is carried out by bringing both into contact in an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 . The solubility parameter (hereinafter sometimes referred to as “SP value”) is preferably in the range of 16.8 to 19.0 MPa ^1/2 , more preferably 18.0 to 18.8 MPa ^1/2 .
In addition, the solubility parameter of an organic solvent can be calculated | required by the method described in the polymer handbook (POLYMER HANDBOOK, JOHN WILEY & SONS company publication).
The amount of the siloxane compound (I) used to coat the reinforcing particles is usually 0.3 to 200 parts by weight, preferably 0.5 to 50 parts by weight, further based on 100 parts by weight of the reinforcing particles. Preferably it is the range of 1-10 weight part.

Examples of the solvent having an SP value in the above range include benzene (SP value = 18.8 MPa ^1/2, hereinafter, the SP value unit may be omitted), toluene (18.2). Aromatic hydrocarbon solvents such as xylene (18.0) and ethylbenzene (18.0); tetrahydrofuran (18.6); cyclohexane (16.8), cyclopentane (17.8), etc. Examples thereof include cycloaliphatic hydrocarbon solvents; ketone solvents such as methyl ethyl ketone (19.0) and diethyl ketone (18.0);
Of these, aromatic hydrocarbon solvents and cycloaliphatic hydrocarbon solvents are preferred, among which toluene, xylene and cyclohexane are preferred, and toluene and xylene are most preferred.
The organic solvent is not particularly limited as long as it has an SP value in the above range, and may be a single solvent or a mixed solvent composed of two or more solvents.

An organic solvent having an SP value outside the above range can be mixed with an organic solvent having an SP value within the above range. In this case, the solvent having the SP value in the above range preferably accounts for 50% by weight or more of the mixed solvent, more preferably 70% by weight or more, and particularly preferably 80% by weight or more.
Examples of the organic solvent having an SP value outside the above range include chain hydrocarbons such as n-pentane (SP value 14.3 MPa ^1/2 ) and n-hexane (14.9) having an SP value lower than the above range. Examples thereof include solvents, alcohol solvents such as n-butanol (23.3) and ethanol (26.0) having an SP value higher than the above range, acetone (20.3), and the like.
If an alcohol solvent having a high SP value is used, the base polymer may be precipitated when the solution of the functional group-containing siloxane compound-coated reinforcing particles is mixed with the base polymer solution. Less is preferable. In addition, when a chain hydrocarbon solvent having a low SP value is used, the stability of the solution (dispersion) of the siloxane compound (I) and reinforcing particles may be lowered. .

The mixing method of the reinforcing particles and the siloxane compound (I) is not particularly limited as long as they are brought into contact with each other in an organic solvent having an SP value of 16.0 to 20.0 MPa ^1/2. It is preferable to dissolve compound (I) in an organic solvent to obtain a uniform solution, and gradually add reinforcing particles to this while stirring.
The concentration of the organic solvent solution of the siloxane compound (I) is not particularly limited, but is usually 0.1 to 20% by weight, preferably 0.2 to 15% by weight, more preferably 0.5 to 10% by weight. . When the concentration is within this range, the viscosity of the resulting solution is easily handled, the coverage of the reinforcing particles is in an appropriate range, and the resulting functional group-containing siloxane compound-coated reinforcing particles are used as the base polymer. Dispersion is good when blended into.

Although the temperature at the time of mixing is not specifically limited, Usually, it is 5 to 200 degreeC, Preferably it is 20 to 150 degreeC, More preferably, it is 30 to 130 degreeC. When the temperature at the time of mixing is within this range, uniform dispersion is easy, and there is no fear of decomposition or deterioration of the siloxane compound (I). Further, when the boiling point is close to the solvent, a problem in terms of operation and safety arises. Therefore, it is preferable to set appropriately considering the boiling point of the solvent.
The stirring speed is usually 10 to 10,000 revolutions / minute, preferably 50 to 5,000 revolutions / minute, and more preferably 100 to 1,000 revolutions / minute. If the speed is excessively low, the reaction efficiency is poor, and the reinforcing particles settle, so the efficiency is poor. The shape of the stirring blade is not particularly limited, and a flat plate, a helical, a double helical and the like can be appropriately combined. Further, it may be mixed at high speed using a homogenizer or the like while applying shear.
The atmosphere during mixing is not particularly limited, but it is preferably performed in an inert atmosphere for safety. The pressure in the system at the time of mixing is not particularly limited. The mixing time is usually about 5 minutes to 3 hours, although it depends on the stirring speed and the like.

In this way, a transparent solution of functional group-containing siloxane compound-coated reinforcing particles can be obtained.
The reinforcing particles coated with the siloxane compound (I) can be separated from the solvent by a suitable method such as evaporation to dryness or centrifugation, and obtained as solid particles. May be. In consideration of the uniformity of mixing with the base polymer, it is preferably in the form of a solution of an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 .

The polymer composition of the present invention comprises 100 parts by weight of a base polymer and 5 to 200 parts by weight, preferably 10 to 150 parts by weight of the functional group-containing siloxane compound-coated reinforcing particles of the present invention.
The type of the base polymer that can be used in the present invention may be appropriately selected according to the use or purpose of use of the polymer composition, and may be a resin or a rubbery polymer.
Examples of resins include aromatic vinyl polymers such as polystyrene; acrylic resins such as polymethyl methacrylate; alicyclic olefin polymers such as dicyclopentadiene polymers; acrylonitrile polymers; olefin resins such as polyethylene and polypropylene; Examples of the vinyl halide polymer include resins such as these hydrogenated polymers.
Examples of the rubbery polymer include diene rubbers such as polybutadiene rubber and styrene-butadiene copolymer rubber; rubbers other than diene rubbers such as butyl rubber, halogenated butyl rubber, and epichlorohydrin rubber.
The base polymer may be solid, solution, emulsion or suspension, but is preferably miscible with functional group-containing siloxane compound coated reinforcing particles obtained by solution polymerization. In view of the above, it is preferably in the form of a solution.

The molecular weight of the base polymer is usually 200,000 to 3,000,000, preferably 350,000 to 2,000,000, more preferably 500,000 to 1,500,000. If the molecular weight is excessively low, the wear characteristics of the polymer composition may be insufficient, and if the molecular weight is excessively high, the viscosity of the polymer composition may be increased and the processability may be deteriorated.
The base polymer is preferably introduced with a group selected from an epoxy group and a glycidyloxyalkyl group, and in addition, a hydroxypolyoxyalkylene group and / or an alkoxypolyoxyalkylene group is further introduced. preferable. When the base polymer contains a group selected from an epoxy group and a glycidyloxyalkyl group and other functional groups, the ratio of the number of moles of the group selected from the epoxy group and the glycidyloxyalkyl group to the total number of moles of the functional group is Higher is preferable. This ratio is preferably 99 to 1 mol%, more preferably 95 to 50 mol%, particularly preferably 90 to 60 mol%.

  Moreover, it is preferable that a base polymer contains the structure represented by general formula (II) in a molecule | numerator.

In the general formula (II), R ⁵ and R ⁶ may each have a hydrogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a functional group having the above polarity. It is a good hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ⁵ and R ⁶ has at least one polar functional group. A plurality of R ⁵ and R ⁶ may be the same or different. m is an integer of 2 to 20,000. The lower limit of m is preferably 3, more preferably 50, and the upper limit is preferably 1,000, more preferably 500.
Examples of the polar functional group having a group 15 or group 16 atom in the periodic table can be the same as the functional group that the siloxane compound (I) can contain. Among these, an epoxy group, a glycidyloxy group, a hydroxypolyoxyalkylene group (polyoxyalkylene group having a hydroxyl group at the terminal) and an alkoxypolyoxyalkylene group (polyoxyalkylene group having an alkoxyl group at the terminal) are preferable.

  The base polymer having a structure represented by the general formula (II) in the molecule is represented by the general formula (IV) or the general formula (V), for example, a polymer having an active terminal obtained by anionic polymerization. It can be obtained by reacting a siloxane compound. The amount of the siloxane compound represented by the following general formula (IV) or general formula (V) is usually 0.01 to 10 mol, preferably 0.1 to 5 mol, more preferably per mol of polymerization active terminal. Is 0.3 to 1.5 mol.

In the general formula (IV), R ⁵ , R ⁶ and m are the same as in the general formula (II). R ⁹ and R ¹⁰ are each a group selected from an alkoxyl group, an epoxy group, a carbonyl group, and an organic group that may have these groups.

In the general formula (V), R ⁵ , R ⁶ and m are the same as in the general formula (II). R ¹¹ is a group selected from an alkoxyl group, an epoxy group, a carbonyl group, and an organic group that may have these groups. R ¹² is a hydrocarbon group having 1 to 20 carbon atoms, an alkoxyl group, or a halogen atom, and when a plurality of R ¹² are present, they may be different from each other. k is an integer of 1 to 4.
The functional group in the siloxane compound represented by the general formula (IV) or the general formula (V) reacts with the polymerization active terminal of the polymer, and the structure represented by the general formula (II) is introduced into the polymer. Is done. At this time, the amount of the functional group in the siloxane compound represented by the general formula (IV) or the general formula (V) is 0.01 to 10 mol on an average per mol of the active terminal of the base polymer, preferably It is preferable to be 0.1 to 5 mol, more preferably 0.3 to 1.5 mol. When the amount of the functional group is within this range, properties such as wear resistance of the resulting polymer composition are improved.

The polymer composition of the present invention can be obtained by blending functional group-containing siloxane compound-coated reinforcing particles with a base polymer.
The method of blending is not particularly limited, and a method of mixing both in a solid state or a method of adding one of them as a solution and adding the other to the solution may be adopted. The group-containing siloxane compound-coated reinforcing particles are preferable because they can be uniformly dispersed in the base polymer.

In the present invention, as a solvent to obtain a base polymer solution, SP value organic solvent is preferably a 10.0～18.8MPa ^1/2, organic solvents 14.0～18.6MPa ^1/2 More preferably, an organic solvent of 14.9 to 18.2 MPa ^1/2 is still more preferable. When an organic solvent having an SP value within this range is used, the solubility of the base polymer becomes appropriate, and the miscibility with the functional group-containing siloxane compound-coated reinforcing particle solution is good.

Examples of the organic solvent having such SP value include benzene (SP value = 18.8 MPa ^1/2 ), toluene (18.2), xylene (18.0), ethylbenzene (18.0), and the like. Aromatic hydrocarbon solvents: cyclic or chain ether solvents such as tetrahydrofuran (18.6), dimethyl ether (18.0), diethyl ether (15.1); n-butane (13.9), n -Pentane (14.3), n-hexane (14.9), n-heptane (15.1), n-octane (15.6), n-decane (13.5), etc. Chain aliphatic hydrocarbon solvents: cycloaliphatic hydrocarbon solvents such as cyclohexane (16.8), methylcyclohexane (16.0), ethylcyclohexane (16.3), cyclopentane (17.8) ; Me Ethyl ketone (19.0), a ketone solvent such as diethyl ketone (18.0); and the like.
Of these, aromatic hydrocarbon solvents, cyclic or chain ether solvents, aliphatic hydrocarbon solvents and cyclic aliphatic hydrocarbon solvents are preferred, more preferably aromatic hydrocarbon solvents, chain aliphatic hydrocarbon solvents, cyclic Aliphatic hydrocarbon solvents are more preferred.
The organic solvent may be a single solvent or a mixed solvent composed of two or more solvents.

Moreover, unless the effect of the present invention is impaired, an organic solvent having an SP value exceeding 18.8 MPa ^1/2 or a solvent other than the organic solvent can be used in combination. When such a mixed solvent is used, the solvent having an SP value in the range of 10.0 to 18.8 MPa ^1/2 preferably accounts for 50% by weight or more of the mixed solvent, and occupies 70% by weight or more. Is more preferable, and it is still more preferable to occupy 80% by weight or more.
Solvents having an SP value exceeding 18.8 MPa ^1/2 include water (SP value = 47.9 MPa ^1/2 ); formamide (39.3), N, N-dimethylformamide (24.8), and methanol. (29.7), ethanol (26.0), isopropyl alcohol (23.5), pyridine (21.9), carbon disulfide (20.5), acetone (20.3), Examples include chloroform (19.0) and methylene chloride (19.8).

  The concentration of the base polymer in the base polymer solution is usually 1 to 50% by weight, preferably 5 to 40% by weight, and more preferably 10 to 30% by weight. When the concentration is within this range, the miscibility with the functional group-containing siloxane compound-coated reinforcing particles is good, the energy required to recover the polymer composition after mixing is in an appropriate range, and the recovery efficiency is also good. Further, the viscosity of the base polymer solution becomes an appropriate level, and the miscibility is also good.

The base polymer solution may be a solution obtained by dissolving the base polymer in an organic solvent, or the base polymer solution obtained by the solution polymerization method may be used as it is, but the solution obtained by solution polymerization may be used. Is preferable because the base polymer is uniformly dissolved. Furthermore, it is preferable to use a base polymer solution in an active state before stopping the reaction as the solution polymerization solution because the physical properties of the resulting polymer composition are improved.
When the solid base polymer is dissolved in the organic solvent, the base polymer is processed into pellets in advance or the size is reduced to 5 cm or less with a pulverizer or the like, and then gradually added to the organic solvent. It is preferable that the dissolution tank is added with stirring at 10 revolutions per minute, preferably 50 revolutions per minute, more preferably 100 revolutions per minute. When the stirring speed is within this range, the base polymer is dissolved well and the solid content does not settle. After dissolving the base polymer, the uniformity may be further improved by using a homogenizer or the like, if necessary.

By mixing the base polymer solution and the functional group-containing siloxane compound-coated reinforcing particle solution, the base polymer and the functional group-containing siloxane compound-coated reinforcing particle having the form of an organic solvent solution are contained. Can be obtained.
At this time, the solubility parameter of the organic solvent of the base polymer solution is 10.0 to 18.8 MPa ^1/2 , and the solubility parameter of the organic solvent of the functional group-containing siloxane compound-coated reinforcing particle solution is 16.0 to 20 0.0 MPa ^1/2 is preferable because it can be uniformly mixed without causing precipitation of the polymer.
The method of mixing the base polymer solution and the solution of the functional group-containing siloxane compound-coated reinforcing particles is not particularly limited, but the functional group-containing siloxane compound-coated reinforcing particles having a higher specific gravity than the base polymer solution. Adopting a method of adding a solution is preferable because it allows more uniform mixing.
The concentration of the mixed solution is usually 1 to 80% by weight, preferably 5 to 50% by weight, and more preferably 10 to 35% by weight, because the mixture can be uniformly mixed in a shorter time.
Stirring conditions and the like during mixing are not particularly limited. Usually, the mixing is performed with stirring at 10 to 10,000 revolutions per minute, preferably 50 to 5,000 revolutions per minute. Moreover, the kind of stirrer etc. are not specifically limited.
Although the addition method at the time of mixing is not specifically limited, In order to achieve uniform mixing, it is preferable to gradually add a solution of functional group-containing siloxane compound-coated reinforcing particles. The time required for the addition is about 5 minutes to 1 hour depending on the amount of the base polymer solution to be mixed and the solution of the functional group-containing siloxane compound-coated reinforcing particles.
Mixing temperature is 0-200 degreeC normally, Preferably it is 20-150 degreeC, More preferably, it is 30-120 degreeC. When mixed in this temperature range, the viscosity of both solutions is close to an appropriate level, and uniform mixing is easy.

A polymer composition in a solid state can be obtained by subjecting a solution of a polymer composition containing the base polymer and functional group-containing siloxane compound-coated reinforcing particles to a solvent removal treatment.
Solvent removal methods include, for example, a method of coagulating by mixing with a poor solvent or adding a coagulant such as an electrolyte to separate the polymer composition from the solvent as a crumb, and the polymer composition solution in hot water. A conventionally known method such as a steam stripping method for injecting and distilling the solvent together with water vapor to precipitate the polymer composition in the form of crumb, or removal of the solvent by vacuum distillation can be employed.
Next, the polymer composition from which the solvent has been separated is purified as necessary. For example, crumbs produced by coagulation or steam stripping are washed with water to remove emulsifiers, electrolytes, and the like. The purpose of this is to remove the emulsifier and the like used for polymerization and coagulation, if they remain in the product polymer as an acid or the like, since this may cause deterioration of the properties of the polymer composition. Next, it is preferable to dry the polymer composition. A conventionally known method can be employed as the drying method. For example, after dewatering by squeezing water with a squeezer or the like, a method using a band ventilation drying device, a vent type extrusion drying device, an expansion type extrusion drying device, or the like is used.

A composition suitable for various uses can be obtained by adding various compounding agents to the polymer composition of the present invention.
Addition of these compounding agents may be performed when the polymer composition is in a solution state, or may be performed after the polymer composition is made solid.

In the present invention, when a rubbery polymer is used as the base polymer of the polymer composition, from now on, in addition to tires, hoses, window frames, belts, shoe soles, anti-vibration rubbers, automobile parts, sponges, mats, etc. A vulcanizable rubber composition suitable as a raw material for rubber products and a composition for modifying the impact resistance of a styrene resin can be obtained.
The vulcanizable rubber composition of the present invention comprises the polymer composition of the present invention containing a rubbery polymer as a base polymer and a vulcanizing agent as essential components.

Examples of the rubbery polymer used in the vulcanizable rubber composition include diene rubbers and rubbers other than diene rubbers.
Diene rubber includes natural rubber, polyisoprene rubber, emulsion polymerization styrene-butadiene copolymer rubber, solution polymerization styrene-butadiene copolymer rubber, polybutadiene rubber, styrene-isoprene copolymer rubber, butadiene-isoprene copolymer. Rubber, solution polymerized styrene-butadiene-isoprene copolymer rubber, emulsion polymerized styrene-butadiene-isoprene copolymer rubber, emulsion polymerized styrene-acrylonitrile-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, high vinyl styrene -Butadiene copolymer-Low vinyl / styrene-butadiene copolymer block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and the like, and can be appropriately selected according to required characteristics. Among these, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, and styrene-isoprene-butadiene copolymer rubber are particularly preferable.
These rubbers can be used alone or in combination of two or more.

In order to obtain a vulcanizable rubber composition suitable for tire use, it is preferable to use a diene rubber as the rubbery polymer. The microstructure of the diene rubber is such that the content ratio of the conjugated diene unit to the aromatic vinyl compound unit (conjugated diene unit: aromatic vinyl compound unit) is 100: 0 to 50:50, and the bonded aromatic When the vinyl compound amount is S and the vinyl bond amount in the conjugated diene unit is V, it is usually 200> 2S + V> 0.1, preferably 170> 2S + V> 55, more preferably 150> 2S + V> 100. When this value is within the above range, it is possible to obtain a rubber composition for tires which is excellent in strength characteristics and wear characteristics and excellent in wet braking performance.
The arrangement pattern of each monomer unit in the diene rubber is not particularly limited, and may be random, block structure, or taper structure. However, the proportion of aromatic vinyl compound units having 8 or more chains should be smaller. It is usually 10% or less, preferably 5% or less, more preferably 1% or less, based on the amount of all-bonded aromatic vinyl compound. Moreover, it is preferable that the conjugated diene unit is contained in at least one terminal of the polymer chain in a block form.

  There are no particular limitations on the vulcanizing agent, for example, sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur; sulfur halides such as sulfur monochloride and sulfur dichloride; dicumyl peroxide, disulfide Organic peroxides such as t-butyl peroxide; quinone dioximes such as p-quinone dioxime and p, p'-dibenzoylquinone dioxime; triethylenetetramine, hexamethylenediamine carbamate, 4,4'-methylenebis Organic polyamine compounds such as -o-chloroaniline; alkylphenol resins having a methylol group; and the like. Among these, sulfur is preferable, and powder sulfur is particularly preferable. These vulcanizing agents are used alone or in combination of two or more.

  The blending ratio of the vulcanizing agent is usually 0.1 to 15 parts by weight, preferably 0.3 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the rubber component. is there. When the blending ratio of the vulcanizing agent is within this range, it is possible to obtain a composition that is excellent in tensile strength and wear resistance and particularly excellent in characteristics such as heat resistance and residual strain.

  In blending these vulcanizing agents, it is preferable to use a vulcanization accelerator and a vulcanization activator in combination. Examples of the vulcanization accelerator include sulfenamide vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide and Nt-butyl-2-benzothiazole sulfenamide; diphenylguanidine, diol Guanidine vulcanization accelerators such as tolylguanidine and orthotolylbiguanidine; thiourea vulcanization accelerators such as thiocarboanilide, diortolylthiourea, ethylenethiourea, diethylthiourea and trimethylthiourea; 2-mercaptobenzothiazole, dibenzothia Thiazole vulcanization accelerators such as dil disulfide and 2-mercaptobenzothiazole zinc salt; thiuram vulcanization accelerators such as tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide and tetraethyl thiuram disulfide; Dithiocarbamate vulcanization accelerators such as sodium rudithiocarbamate, sodium di-n-butyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate; isopropylxanthate sodium, isopropylxanthogen Examples thereof include xanthate-based vulcanization accelerators such as zinc acid and zinc butylxanthate;

These vulcanization accelerators are used alone or in combination of two or more, and those containing at least a sulfenamide vulcanization accelerator are particularly preferred. Among those containing a sulfenamide-based vulcanization accelerator, those having a sulfenamide-based vulcanization accelerator ratio of 30% by weight or more based on the total vulcanization accelerator are preferable.
The blending ratio of the vulcanization accelerator is usually 0.1 to 15 parts by weight, preferably 0.3 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the rubber component. It is.

  Although there is no restriction | limiting in particular as a vulcanization activator, For example, higher fatty acids, such as a stearic acid, zinc oxide, etc. can be used. As zinc oxide, for example, it is preferable to use one having a high surface activity particle size of 5 μm or less, and specific examples thereof include active zinc white having a particle size of 0.05 to 0.2 μm or 0.3 to 1 μm, for example. The zinc white can be mentioned. In addition, zinc oxide surface-treated with an amine-based dispersant or wetting agent can be used.

  These vulcanization activators can be used alone or in combination of two or more. The mixing ratio of the vulcanization activator is appropriately selected depending on the type of the vulcanization activator. When a higher fatty acid is used, it is usually added in an amount of 0.05 to 15 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight per 100 parts by weight of the rubber component. When zinc oxide is used, it is generally added in an amount of 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the rubber component. When the blending ratio of the vulcanization activator is within this range, the properties such as processability, tensile strength, and wear resistance of the composition are highly balanced, which is preferable.

  The vulcanizable rubber composition of the present invention includes a rubber-like polymer and functional group-containing siloxane compound-coated reinforcing particles contained in the polymer composition, a polymer other than the rubber-like polymer; silica, hydrophobic Reactive agents other than functional group-containing siloxane compound-coated reinforcing particles such as SAF, ISAF, HAF, FEF, acetylene black, carbon black, carbon black such as fullerene, and the like can be blended as necessary. .

The vulcanizable rubber composition of the present invention can be blended with various additives usually used in this field.
Such additives include fillers such as calcium carbonate, talc, titanium oxide, magnesium oxide, zinc oxide, aluminum hydroxide, and ground silica; bis- [3- (triethoxysilyl) propyl] tetrasulfide, bis- (Triethoxysilylpropyl) monosulfide, bis- (triethoxysilylpropyl) disulfide, bis- (2-triethoxysilylpropyl) tetrasulfide, bis- (2-triethoxysilylpropyl) pentasulfide, bis- (2- Silane coupling agents such as triethoxysilylpropyl) hexasulfide and 3-octathio-1-propylethoxysilane; naphthenic, paraffinic or aromatic process oils; plasticizers such as dioctylphthalate; mineral process oils; rapeseed oil , Tung oil, toe And the like can be given; petroleum synthetic oils; terpene resins, petroleum resins; animal oils of beef tallow; oil, linseed oil, plant oil palm oil and the like anti-aging agents. The amount of these compounding agents may be in a range usually used.
The vulcanizable rubber composition of the present invention can be obtained by blending each component according to a conventional method.
In blending, each component may be added to the functional group-containing siloxane compound-coated reinforcing particles of the present invention, and may be added to the rubber-like polymer and the functional group-containing siloxane compound-coated reinforcing particles. May be added at any time.
The vulcanizable rubber composition of the present invention is particularly suitable for use as a tire tread of a fuel-efficient tire because it is excellent in low heat build-up, but other tire treads such as all-season tires, high-performance tires, studless tires, It can be suitably used for various tire applications such as side walls, under treads, carcass, and bead portions.

Hereinafter, the present invention will be described more specifically with reference to reference examples, examples and comparative examples. In addition, the part and% in each example are mass references | standards unless there is particular notice.
Each characteristic was evaluated by the following method.
In the present embodiment, the SP value may be described by omitting the unit (MPa ^1/2 ).

[Polymer molecular weight]
Calculated as polystyrene equivalent molecular weight by high performance liquid chromatography. Specifically, using HLC8220 manufactured by Tosoh Corporation, using two GMH-HR-H columns and using tetrahydrofuran (THF), measurement is performed at a rate of 40 ° C. and 1 ml / min. The molecular weight calibration is performed with 12 points of standard polystyrene (500 to 3 million) manufactured by Polymer Laboratories.
[Polymer microstructure]
Measured by NMR.

[Amount of reinforcing particles in polymer composition]
Measurement is performed using a thermogravimetric analyzer (TGA) according to JIS K6226-1. A sample (polymer composition containing reinforcing particles of mass F0) is maintained at 550 ° C. for 15 minutes, and the amount (F) of reinforcing particles remaining after all organic components are decomposed and volatilized is measured. The ratio of the reinforcing particles incorporated into the polymer composition (incorporation ratio) (%) is:
Uptake ratio (%) = 100 × F / F0.

[Tensile strength] and [Elongation]:
The sample after vulcanization at 160 ° C. for 30 minutes is measured using dumbbell-shaped No. 3 according to JIS K6251: 1993. The units of measurement for tensile strength and elongation are MPa and%, respectively.

[Low heat generation]
For a sample after vulcanization at 160 ° C. for 30 minutes, tan δ is measured at 60 ° C. under a dynamic strain of 0.5% and a frequency of 20 Hz using a viscoelasticity measuring device (RDA-II manufactured by Rheometrics). This measured value is converted into an index with the reference sample as 100. It shows that it is excellent in low exothermic property, so that the numerical value of an index | exponent is small.

[Abrasion resistance]
The sample after vulcanization at 160 ° C. for 30 minutes is carried out with a pico abrasion tester according to JIS K6242: 1993. The unit of measurement is cc. The reciprocal of the measured value is indicated by an index with the reference sample as 100. The higher the index value, the better the wear resistance.

[Reference Example 1]
(Production of siloxane structure-containing base polymer (P1))
Using an autoclave with a stirrer, styrene and butadiene were copolymerized with an alkyllithium catalyst in a mixed solvent (ratio 10/90) of n-hexane (SP value 14.9) / cyclohexane (SP value 16.8). It was. Without stopping the reaction, an amount of the siloxane compound of the following formula (VI) was added in such an amount that the epoxy group of the siloxane compound was 1 equivalent with respect to the polymerization active terminal. As a result, the solid content of the siloxane structure-containing base polymer (P1) in which the styrene-butadiene copolymer portion has a bound styrene content of 21%, a butadiene unit portion has a vinyl bond content of 63%, and a weight average molecular weight of 700,000. A 20% min solution was obtained.

  In the formula (VI), the number of each monomer unit is a number average value, and the arrangement of the monomer units is random.

[Reference Example 2]
(Production of silyl group-containing base polymer (P2))
Styrene-butadiene in the same manner as in Reference Example 1 except that tetramethoxysilane (TMOS) was used in such an amount that the methoxy group was 0.8 equivalent to the polymerization active terminal instead of the siloxane compound of the formula (VI). A solution of a silyl group-containing base polymer (P2) having a bound styrene content of the copolymer part of 21%, a vinyl bond content ratio of the butadiene unit part of 63%, and a weight average molecular weight of 700,000 was obtained.

[Example 1]
(Example 1A): Production of functional group-containing siloxane compound-coated silica particles A solution of 5 parts of functional group-containing siloxane compound (a) / 100 parts of xylene (SP value 18.0) shown in Table 1 was subjected to dehydration and A homogeneous solution was obtained by dissolving in 1,000 parts of purified cyclohexane. While stirring the solution at 100 rpm with a stirrer at 70 ° C., 75 parts of wet silica (manufactured by Rhodia, nitrogen adsorption specific surface area (BET) 165 m ^{2 /} g, hydrous silicic acid pH 6.5, commercial product) No. Z1165MP) was gradually added over 10 minutes, and mixing was further continued for 10 minutes to obtain a solution (A1) of functional group-containing siloxane compound-coated silica particles (see Table 2).

  The functional group-containing siloxane compounds (a) to (d) and the siloxane compound (e) not containing a functional group used in each example and comparative example are represented by the general formula (VII). In the compound represented by the general formula (VII), the arrangement of each monomer unit is random. Specific structures of these siloxane compounds are as shown in Table 1.

  In Table 1, POA represents a polyoxyethylene chain having an average degree of condensation of 2.5. GOP represents a 3-glycidoxypropyl group.

Example 1B: Production of Polymer Composition Using Functional Group-Containing Siloxane Compound-Coated Silica Particles In cyclohexane solution (A1) containing 80 parts of functional group-containing siloxane compound-coated silica particles obtained in Example 1A, 70 Under stirring at 100 ° C. per minute at 100 ° C., 100 parts of an n-hexane / cyclohexane solution of the siloxane structure-containing base polymer (P1) obtained in Reference Example 1 was gradually added over 10 minutes. After completion of the addition, stirring was continued for another 10 minutes to homogenize the mixed solution to obtain a polymer composition solution (BS1).
After adding 0.1 part of 2-methyl-4,6-bis [(octylthio) methyl] phenol as an anti-aging agent to the obtained polymer composition solution (BS1), the solvent is removed by a steam stripping method. Thus, a solid polymer composition (B1) was obtained. The resulting polymer composition was soft rubbery.
There was no white turbidity of the coagulated water (referred to as an aqueous phase after separating the crumb after steam stripping), and the polymer composition (B1) was analyzed with a thermogravimetric analyzer (TGA). Met. This indicates that the total amount of silica used was incorporated into the polymer composition (uptake ratio = 100%) (see Table 2).

(Example 1C): Physical property evaluation of polymer composition The same operation as Example 1A and Example 1B was performed, and the polymer composition solution (BS1) containing 180 parts of polymer compositions was obtained. To this, 20 parts of aroma-based process oil, 10 parts of carbon black adsorbate of silane coupling agent (mixing ratio 50/50, manufactured by Degussa, trade name X50S), 5 parts of additional blended silica, 5 parts of zinc white, stearic acid 3 Part and anti-aging agent 6C (N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine) 2 parts and wax-type anti-aging agent (Ouchi Shinsei Chemical Co., Ltd., Sannok) 1 part Add, homogenize using a Banbury mixer at 150 ° C. under conditions of 70 revolutions per minute, desolvate by steam stripping, dehydrate with a water squeezer until the water content is about 10%, then 150 After extrusion with a single screw extruder at 60 ° C., it was dried with hot air for 60 minutes to obtain 226 parts of a rubber composition.
To the obtained rubber composition, using a roll at 50 ° C., 1.8 parts of sulfur, 1.1 parts of vulcanization accelerator DPG (1,3-diphenylguanidine) and CBS (N-cyclohexyl-2- A vulcanizable rubber composition (C1) was obtained by blending 1.8 parts of benzothiazolylsulfenamide).
The physical properties of the obtained vulcanizable rubber composition (C) were evaluated. The results are shown in Table 3. In Table 3, the low heat build-up and wear resistance of the vulcanizable rubber composition are shown as an index with the numerical value of Comparative Example 2C being 100.

[Example 2]
(Example 2A)
A solution (A2) of functional group-containing siloxane compound-coated silica particles was obtained in the same manner as in Example 1A except that the amount of the functional group-containing siloxane compound (a) was changed to 3 parts (see Table 2).
(Example 2B)
A polymer composition solution (BS2) is obtained in the same manner as in Example 1B except that the solution (A2) is used instead of the solution (A1) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer is obtained therefrom. A composition (B2) was obtained. The obtained polymer composition (B2) was soft rubbery.
Moreover, when the polymer composition (B2) was analyzed by TGA without white turbidity of coagulated water, the amount of silica contained was 75 parts. This indicates that the total amount of silica used was incorporated into the polymer composition (uptake ratio = 100%) (see Table 2).

[Example 3]
(Example 3A)
A solution (A3) of functional group-containing siloxane compound-coated silica particles was obtained in the same manner as in Example 1A except that the amount of the functional group-containing siloxane compound (a) was changed to 1.5 parts (see Table 2). .
(Example 3B)
A polymer composition solution (BS3) is obtained in the same manner as in Example 1B except that the solution (A3) is used in place of the solution (A1) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer is obtained therefrom. A composition (B3) was obtained. The obtained polymer composition (B3) was soft rubbery.
Moreover, there was almost no cloudiness of coagulated water, and when the polymer composition (B3) was analyzed by TGA, the amount of silica contained was 74.6 parts. This indicates that 99.5% of the silica used was incorporated into the polymer composition (uptake ratio = 99.5%) (see Table 2).
(Example 3C)
Using the polymer composition solution (BS3), following the formulation shown in Table 3 (in addition, the weight of silica in the total formulation = the weight of the silica particles in the functional group-containing siloxane compound-coated silica particles and the weight of the additional blended silica) In the same manner as Example 1C, a vulcanizable rubber composition (C3) was obtained. The physical properties of the vulcanizable rubber composition (C3) were evaluated. The results are shown in Table 3.

[Example 4]
(Example 4A)
A solution (A4) of functional group-containing siloxane compound-coated silica particles was prepared in the same manner as in Example 1A, except that 5 parts of the functional group-containing siloxane compound (a) was changed to 2.5 parts of the functional group-containing siloxane compound (b). Obtained (see Table 2).
(Example 4B)
A polymer composition solution (BS4) is obtained in the same manner as in Example 1B except that the solution (A4) is used in place of the solution (A1) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer is obtained therefrom. A composition (B4) was obtained. The obtained polymer composition (B4) was soft rubbery.
Moreover, when the polymer composition (B4) was analyzed by TGA without white turbidity of coagulated water, the content of silica was 75 parts. This indicates that the total amount of silica used was incorporated into the polymer composition (uptake ratio = 100%) (see Table 2).

[Example 5]
(Example 5A)
A solution (A5) of functional group-containing siloxane compound-coated silica particles was prepared in the same manner as in Example 1A except that 5 parts of the functional group-containing siloxane compound (a) was changed to 2.5 parts of the functional group-containing siloxane compound (c). Obtained (see Table 2).
(Example 5B)
A polymer composition solution (BS5) is obtained in the same manner as in Example 1B except that the solution (A5) is used in place of the solution (A1) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer is obtained therefrom. A composition (B5) was obtained. The obtained polymer composition (B5) was soft rubbery.
Moreover, there was no cloudiness of coagulation water, and when the polymer composition (B5) was analyzed by TGA, the amount of silica contained was 75 parts. This indicates that the total amount of silica used was incorporated into the polymer composition (uptake ratio = 100%) (see Table 2).

[Example 6]
(Example 6A)
A solution (A6) of functional group-containing siloxane compound-coated silica particles was prepared in the same manner as in Example 1A, except that 5 parts of the functional group-containing siloxane compound (a) was changed to 2.5 parts of the functional group-containing siloxane compound (d). Obtained (see Table 2).
(Example 6B)
The solution (A6) is used instead of the solution (A1) of the functional group-containing siloxane compound-coated silica particles, and the silyl group-containing base polymer (P2) is used instead of the siloxane structure-containing base polymer (P1). Obtained a polymer composition solution (BS6) in the same manner as in Example 1B, and further obtained a solid polymer composition (B6). The obtained polymer composition (B6) was soft rubbery.
Moreover, there was no cloudiness of coagulation water, and when the polymer composition (B6) was analyzed by TGA, the amount of silica contained was 75 parts. This indicates that the total amount of silica used was incorporated into the polymer composition (uptake ratio = 100%) (see Table 2).

[Example 7]
(Example 7A)
A solution (A7) of functional group-containing siloxane compound-coated silica particles was obtained in the same manner as in Example 6A, except that the stirrer speed was 50 rpm (see Table 2).
(Example 7B)
A polymer composition solution (BS7) is obtained in the same manner as in Example 6B except that the solution (A7) is used instead of the solution (A6) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer is obtained therefrom. A composition (B7) was obtained. The resulting polymer composition (B7) was soft rubbery.
Moreover, when the polymer composition (B7) was analyzed by TGA without white turbidity of coagulated water, the content of silica was 74.4 parts. This indicates that 99.2% of the silica used was incorporated into the polymer composition (uptake ratio = 99.2%) (see Table 2).

[Example 8]
(Example 8A)
A solution (A8) of functional group-containing siloxane compound-coated silica particles was obtained in the same manner as in Example 7A except that the temperature during stirring was 30 ° C. (see Table 2).
(Example 8B)
A polymer composition solution (BS8) was obtained in the same manner as in Example 7B except that the solution (A8) was used instead of the solution (A7) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer was obtained therefrom. A composition (B8) was obtained. The obtained polymer composition (B8) was soft rubbery.
Moreover, there was almost no cloudiness of coagulated water, and when the polymer composition (B8) was analyzed by TGA, the amount of silica contained was 74.1 parts. This indicates that 98.8% of the silica used was incorporated into the polymer composition (uptake ratio = 98.8%) (see Table 2).
(Example 8C)
Using the polymer composition solution (BS8), the composition shown in Table 2 was followed (in addition, the weight of silica in the entire composition = the weight of silica particles in the functional group-containing siloxane compound-coated silica particles and the weight of additional compounded silica) Was added in such a manner that the total amount of was 80 parts.) Was obtained in the same manner as in Example 1C to obtain a vulcanizable rubber composition (C8). The physical properties of the vulcanizable rubber composition (C8) were evaluated. The results are shown in Table 3.

[Comparative Example 1]
(Comparative Example 1A)
A solution (Ac1) of siloxane compound-coated silica particles containing no functional group is obtained in the same manner as in Example 6A, except that the functional group-containing siloxane compound (d) is changed to a siloxane compound (e) containing no functional group. (See Table 2).
(Comparative Example 1B)
A polymer composition solution (BSc1) was obtained in the same manner as in Example 6B except that the solution (Ac1) of siloxane compound-coated silica particles not containing a functional group was used instead of the solution (A6) of functional group-containing siloxane compound-coated silica particles. From this, a solid polymer composition (Bc1) was obtained. The obtained polymer composition (Bc1) was soft rubbery.
Further, white turbidity of coagulated water was observed, and when the polymer composition (Bc1) was analyzed by TGA, the amount of silica contained was 71.3 parts. This indicates that 95.0% of the silica used was incorporated into the polymer composition (uptake ratio = 95.0%) (see Table 2).
(Comparative Example 1C)
In addition to using the polymer composition solution (BSc1), the formulation shown in Table 2 was followed (in addition, the silica weight in the total formulation = the weight of the silica particles in the siloxane compound-coated silica particles containing no functional groups and the additional formulation) In the same manner as in Example 1C, a vulcanizable rubber composition (Cc1) was obtained by adding silica so that the total weight of silica = 80 parts. The physical properties of the vulcanizable rubber composition (Cc1) were evaluated. The results are shown in Table 3.

[Comparative Example 4]
(Comparative Example 2A)
A solution (Ac2) of tetramethoxysilane-treated silica particles was obtained in the same manner as in Example 6A except that the functional group-containing siloxane compound (d) was changed to tetramethoxysilane (TMOS) (see Table 2).
(Comparative Example 2B)
A polymer composition solution (BSc2) was obtained in the same manner as in Example 6B except that the solution (Ac2) was used instead of the solution (A6) of the functional group-containing siloxane compound-coated silica particles, and a solid polymer was obtained therefrom. A composition (Bc2) was obtained. The obtained polymer composition (Bc2) was soft rubbery.
Moreover, there was almost no cloudiness of coagulated water, and when the polymer composition (Bc2) was analyzed by TGA, the amount of silica contained was 74.5 parts. This indicates that 99.3% of the silica used was incorporated into the polymer composition (uptake ratio = 99.3%) (see Table 2).
(Comparative Example 2C)
Using the polymer composition solution (BSc2), following the formulation shown in Table 2 (in addition, silica weight in all formulations = total weight of silica particles in tetramethoxysilane-treated silica particles and additional compounded silica weight) In the same manner as in Example 1C, a vulcanizable rubber composition (Cc2) was obtained. The physical properties of the vulcanizable rubber composition (Cc2) were evaluated. The results are shown in Table 3.

[Comparative Example 3]
(Comparative Example 3A)
A silica particle solution (Ac3) was obtained in the same manner as in Example 6A except that the functional group-containing siloxane compound (d) was changed to an aroma-based process oil (FLEX M manufactured by Fuji Kosan Co., Ltd.) (see Table 2). ).
(Comparative Example 3B)
A polymer composition solution (BSc3) was obtained in the same manner as in Example 6B except that the silica particle solution (Ac3) was used instead of the functional group-containing siloxane compound-coated silica particle solution (A6). A polymer composition (Bc3) was obtained. The resulting polymer composition (Bc3) was soft rubbery.
Moreover, the white turbidity of coagulated water was remarkable, and when the polymer composition (Bc3) was analyzed by TGA, the amount of silica contained was 70.1 parts. This indicates that only 93.5% of the silica used was incorporated into the polymer composition (uptake ratio = 93.5%) (see Table 2).
(Comparative Example 3C)
Using the polymer composition solution (BSc3) and following the formulation shown in Table 2 (in addition, the silica weight in the total formulation = the weight of the silica particles remaining in the polymer composition solution (BSc3) and the additional blended silica) Was added in the same manner as in Example 1C to obtain a vulcanizable rubber composition (Cc3). The physical properties of the vulcanizable rubber composition (Cc3) were evaluated. The results are shown in Table 3.

From the results shown in Tables 2 and 3, when silica particles obtained by coating with a siloxane compound having no polar functional group were used (Comparative Example 1), one silica particle was obtained before obtaining a polymer composition. The vulcanizable rubber composition obtained from this polymer composition was washed out compared to the case where a siloxane compound having a polar functional group was used (Examples 1, 3 and 8). It can be seen that the strength, low heat build-up and wear resistance are greatly inferior.
Even when silica particles treated with tetramethoxysilane are used, the resulting vulcanizable rubber composition is greatly inferior in tensile strength, low heat build-up and wear resistance compared to Examples 1, 3 and 8. I understand.
In addition, when the surface treatment of silica was performed with an aroma-based process oil instead of a siloxane compound (Comparative Example 3), the amount of silica particles lost until obtaining the polymer composition was as large as 6.5% of the amount used, It can be seen that the vulcanizable rubber composition obtained from this polymer composition is low in strength and elongation, inferior in low exothermic property, and inferior in wear resistance.

  In contrast, a vulcanizable rubber composition obtained from a polymer composition containing a rubber-like polymer obtained using the functional group-containing siloxane compound-coated silica particles of the present invention has a tensile strength, elongation and low heat generation. It turns out that it is excellent in both the property and abrasion resistance.

  Thus, according to the present invention, a polymer composition having excellent dispersibility of reinforcing particles can be obtained. Moreover, according to the present invention, reinforcing particles suitable for obtaining this polymer composition can be obtained. Furthermore, according to the present invention, a vulcanizable rubber composition excellent in mechanical strength, silica dispersibility and abrasion resistance can be obtained.

Claims (11)

In an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 in an amount of 100 parts by weight of reinforcing particles having a silanol group on the surface, the general formula (I):

[In General Formula (I), each of R ^{1 to} R ⁴ represents a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or a functional group having the above polarity. A hydrocarbon group having 1 to 20 carbon atoms which may have a group, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group or the polar functional group It is a hydrocarbon group of number 1-20. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000. ] The functional group-containing siloxane compound-coated reinforcing particles coated with 0.3 to 200 parts by weight of the functional group-containing siloxane compound represented by the formula: The functional group-containing siloxane compound coating according to claim 1, wherein at least one of R ² and R ³ has at least one polyoxyalkylene group in the functional group-containing siloxane compound represented by the general formula (I). Reinforcing particles. The functional group-containing siloxane compound-coated reinforcing particles according to claim 1 or 2, having a form of a solution of an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 . In an organic solvent having a solubility parameter of 16.0 to 20.0 MPa ^1/2 in an amount of 100 parts by weight of reinforcing particles having a silanol group on the surface, the general formula (I):

[In General Formula (I), each of R ^{1 to} R ⁴ represents a hydrogen atom, a halogen atom, a polar functional group having a group 15 or 16 atom in the periodic table, or a halogen atom or a functional group having the above polarity. A hydrocarbon group having 1 to 20 carbon atoms which may have a group, and at least one of R ^{1 to} R ⁴ is a halogen atom or the polar functional group or the polar functional group It is a hydrocarbon group of number 1-20. A plurality of R ² and R ^{3 which} are present respectively may be the same or different. n is an integer of 2 to 20,000. The functional group-containing siloxane compound-coated reinforcing particles are mixed with 0.3 to 200 parts by weight of a functional group-containing siloxane compound represented by the formula:   A polymer composition comprising 100 parts by weight of a base polymer and 5 to 200 parts by weight of the functional group-containing siloxane compound-coated reinforcing particles according to claim 1 or 2. The base polymer has the general formula (II):

[In General Formula (II), R ⁵ and R ⁶ each have a hydrogen atom, a polar functional group having an atom of Group 15 or 16 of the periodic table, or a functional group having the above polarity. Or a hydrocarbon group having 1 to 20 carbon atoms, and at least one of R ⁵ and R ⁶ has at least one polar functional group. A plurality of R ⁵ and R ⁶ may be the same or different. m is an integer of 2 to 20,000. ] The polymer composition of Claim 5 which contains the structure represented by this in a molecule | numerator.   The polymer composition according to claim 5 or 6, wherein the base polymer is a rubber-like polymer.   The manufacturing method of the polymer composition of Claim 5 which mix | blends the functional group containing siloxane compound covering reinforcing particle of Claim 1 or 2 with a base polymer. A functional group-containing siloxane compound-coated reinforcing particle having the form of an organic solvent solution according to claim 3 and a base polymer are dissolved in an organic solvent having a solubility parameter of 10.0 to 18.8 MPa ^1/2. The method for producing a polymer composition according to claim 5, comprising mixing the solution.   A vulcanizable rubber composition comprising the polymer composition according to claim 7 and a vulcanizing agent.   The vulcanizable rubber composition according to claim 10, which is used for tires.