WO2019130800A1 - Method for producing rubber wet master batch and method for producing rubber composition for tires - Google Patents

Method for producing rubber wet master batch and method for producing rubber composition for tires Download PDF

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Publication number
WO2019130800A1
WO2019130800A1 PCT/JP2018/040477 JP2018040477W WO2019130800A1 WO 2019130800 A1 WO2019130800 A1 WO 2019130800A1 JP 2018040477 W JP2018040477 W JP 2018040477W WO 2019130800 A1 WO2019130800 A1 WO 2019130800A1
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WIPO (PCT)
Prior art keywords
rubber
carbon black
latex solution
rubber latex
producing
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PCT/JP2018/040477
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French (fr)
Japanese (ja)
Inventor
惇 田中
野村 健治
Original Assignee
Toyo Tire株式会社
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Filing date
Publication date
Priority claimed from JP2017247660A external-priority patent/JP7067917B2/en
Priority claimed from JP2017247640A external-priority patent/JP7066398B2/en
Priority claimed from JP2017247655A external-priority patent/JP2019112543A/en
Application filed by Toyo Tire株式会社 filed Critical Toyo Tire株式会社
Publication of WO2019130800A1 publication Critical patent/WO2019130800A1/en

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60CVEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C1/00Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00Processes of treating or compounding macromolecular substances
    • C08J3/20Compounding polymers with additives, e.g. colouring
    • C08J3/22Compounding polymers with additives, e.g. colouring using masterbatch techniques
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00Use of inorganic substances as compounding ingredients
    • C08K3/02Elements
    • C08K3/04Carbon
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08LCOMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L7/00Compositions of natural rubber
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08LCOMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Definitions

  • the present invention relates to a method for producing a rubber wet masterbatch obtained using at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials.
  • the present invention also relates to a method of producing a rubber composition for a tire.
  • a rubber wet masterbatch When a rubber wet masterbatch is used, it has excellent carbon black dispersibility and rubber physical properties such as processability and reinforcement, as compared with a rubber dry masterbatch obtained by mixing carbon black and rubber in a solid phase.
  • the rubber composition which is excellent in is obtained.
  • rolling resistance can be reduced, and a rubber product (vulcanized rubber) such as a pneumatic tire having excellent fatigue resistance can be manufactured.
  • the abrasion resistance and low heat buildup can be achieved by adjusting the pH in the preparation step of the above-mentioned carbon black-containing slurry solution or the above-mentioned preparation step of the carbon black-containing rubber coagulated material to a predetermined range. It is known that rubber products (vulcanized rubber) having improved rubber properties such as are obtained (Patent Documents 1 to 4).
  • rubber products such as pneumatic tires obtained from a rubber composition containing a rubber wet masterbatch have the above-mentioned reduction in rolling resistance, fatigue resistance, low heat buildup, wear resistance, and resistance What is excellent in tear resistance such as cracking is required (Patent Documents 5 and 6).
  • vulcanized rubber obtained from a rubber composition containing a rubber wet masterbatch as in the above-mentioned patent documents has room for improvement in the abrasion resistance and tear resistance.
  • a vulcanized rubber obtained from a rubber composition containing a rubber wet masterbatch as in the above-mentioned patent documents is particularly used for pre-papping (member for covering a cord in a carcass ply of a pneumatic tire or a belt ply). It turned out that there is room for improvement in low heat build-up and fatigue resistance.
  • the first object of the present invention is made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a method for producing a rubber wet masterbatch having good dispersibility (homogeneity) of carbon black.
  • the second object of the present invention is made in view of the above situation, and provides a method for producing a rubber composition for a tire from which a vulcanized rubber having excellent abrasion resistance and tear resistance can be obtained. It is to be.
  • the third object of the present invention is made in view of the above-mentioned circumstances, and it is a method for producing a rubber composition for pretipping which can obtain a vulcanized rubber having excellent low heat buildup and fatigue resistance. It is to provide.
  • the present invention is a method for producing a rubber wet masterbatch obtained using at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials, wherein the carbon black, the dispersion solvent, and the rubber latex solution are mixed to obtain carbon.
  • the mechanical stability of the rubber latex solution measured according to ASTM D 1076-59 is 300 seconds or more, and in the step (II), the pH of the carbon black-containing latex solution before coagulation is 6.
  • Rubber wet master bag characterized in that it is 0 to 8.5 Method of manufacture, related to.
  • the present invention further includes a step (IV) of dry mixing using the rubber wet masterbatch obtained by the method of producing a rubber wet masterbatch, and a method of producing a rubber composition for a tire. About.
  • the rubber measured according to ASTM D 1076-59 in the step (I) for producing the carbon black-containing rubber latex solution described above The mechanical stability of the latex solution is 300 seconds or more, and in the step (II) of producing the carbon black-containing rubber coagulated product as described above, the pH of the carbon black-containing latex solution before coagulation is 6.0 to It is 8.5.
  • the mechanical stability is an index showing colloidal stability, and in the case of the small mechanical stability, rubber latex particles are aggregated by a small stimulus.
  • the carbon black-containing rubber latex solution obtained by using the rubber latex solution having high mechanical stability has high stability of latex particles, the reactivity between the rubber latex particles and carbon black is low. It is estimated that the dispersibility of carbon black in the medium is insufficient.
  • a carbon black-containing rubber latex solution is coagulated, coagulation due to shearing or heat during mixing occurs more dominantly than coagulation due to reaction between latex particles and carbon black, and the obtained rubber wet masterbatch The dispersibility (homogeneity) of carbon black will become inadequate.
  • the pH of the carbon black-containing rubber latex solution is adjusted to a range of 6.0 to 8.5 before coagulation with a coagulant.
  • the reactivity between the rubber latex particles and the carbon black can be kept optimum, and the dispersibility of the carbon black can be improved.
  • rapid solidification can be prevented in the subsequent solidification step, it is presumed that carbon black is uniformly incorporated into the coagulated body of the rubber latex particles while maintaining its dispersibility. As a result, it is considered that a rubber wet masterbatch having good carbon black dispersibility (homogeneity) can be obtained.
  • the rubber composition containing such a rubber wet masterbatch is presumed to have good dispersibility (homogeneity) of carbon black in the rubber composition, so that the resulting vulcanized rubber has excellent abrasion resistance and resistance. It is excellent in tearability or low heat buildup and fatigue resistance.
  • the method for producing a rubber wet masterbatch of the present invention uses at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials.
  • conductive carbon blacks such as acetylene black and ketjen black
  • carbon black used by usual rubber industry such as SAF, ISAF, HAF, FEF, GPF, for example.
  • the carbon black may be granulated carbon black or non-granulated carbon black which is granulated in consideration of its handling property in ordinary rubber industry.
  • the carbon black may be used alone or in combination of two or more.
  • the carbon black from the viewpoint of improving the wear resistance of the vulcanized rubber, the nitrogen adsorption specific surface area, is preferably 50 m 2 / g or more, more preferably 60 m 2 / g or more, 70m 2 / more preferably g or more, and is preferably at 200 meters 2 / g or less, more preferably 190 m 2 / g or less, and more preferably not more than 180 m 2 / g.
  • the carbon black preferably has a nitrogen adsorption specific surface area of 20 m 2 / g or more, more preferably 25 m 2 / g or more, from the viewpoint of improving the low heat buildup of the vulcanized rubber, and more preferably 30 m. still more preferably 2 / g or more, and is preferably from 100 m 2 / g, more preferably 95 m 2 / g or less, and more preferably not more than 90m 2 / g.
  • the content of the carbon black is preferably 20 to 100 parts by weight, preferably 30 to 90 parts by weight, with respect to 100 parts by weight of the rubber component contained in the rubber composition, from the viewpoint of improving the reinforcing property of the vulcanized rubber. It is more preferably part, and still more preferably 40 to 80 parts by weight.
  • the content of the carbon black is preferably 10 to 100 parts by weight with respect to 100 parts by weight of the rubber component contained in the rubber wet master batch, from the viewpoint of improving the reinforcing property of the vulcanized rubber.
  • the amount is more preferably 90 parts by weight, further preferably 20 to 80 parts by weight.
  • Water is particularly preferably used as the dispersion solvent, but it may be, for example, water containing an organic solvent.
  • the dispersion solvents may be used alone or in combination of two or more.
  • the rubber latex solution a natural rubber latex solution and a synthetic rubber latex solution can be used.
  • the natural rubber latex solution is a natural product produced by the metabolism of plants, and a natural rubber / water system in which the dispersion solvent is water is particularly preferable.
  • the number average molecular weight of the natural rubber contained in the natural rubber latex is preferably 2,000,000 or more, and more preferably 2,500,000 or more.
  • As the natural rubber latex solution concentrated latex, fresh latex called field latex, etc. can be used without distinction.
  • Examples of the synthetic rubber latex solution include those prepared by emulsion polymerization of styrene-butadiene rubber, butadiene rubber, nitrile rubber and chloroprene rubber.
  • the rubber latex solution may be used alone or in combination of two or more.
  • the rubber latex solution has a mechanical stability (also referred to as mechanical stability) of 300 seconds or more, which is measured according to ASTM D 1076-59.
  • the mechanical stability is preferably 300 seconds or more, more preferably 400 seconds or more, from the viewpoint of improving the storage stability and the viewpoint of improving the homogeneity of carbon black in the rubber wet masterbatch. .
  • the mechanical stability is determined according to ASTM D 1076-59 by the time until a coagulated substance is found in the latex when the rotating plate is agitated at a predetermined rotation speed.
  • the mechanical stability is exemplified by, for example, 3600 seconds or less and 2400 seconds or less as the upper limit value.
  • the above-mentioned mechanical stability includes basic compounds such as ammonia, sodium hydroxide and potassium hydroxide; aromatic carboxylic acid salts such as sodium salicylate; long-chain fatty acid salts such as ammonium laurate; formic acid, acetic acid, propionic acid and the like Adjustment agents such as short-chain fatty acids; and the like can be adjusted to the above range by adding them to the raw material rubber latex solution. Among these, it is preferable to use ammonia. When these modifiers are used, the concentration of the rubber latex solution is not limited, but from the viewpoint of stabilization of the rubber latex solution, it is preferable to use the rubber latex solution after 12 hours or more after preparation.
  • the production method comprises the step (I) of mixing the carbon black, the dispersion solvent, and the rubber latex solution to produce a carbon black-containing rubber latex solution, and coagulating the obtained carbon black-containing rubber latex solution And the step (II) of producing a carbon black-containing rubber coagulated product.
  • the mechanical stability of the rubber latex solution measured according to ASTM D 1076-59 is 300 seconds or more, and in the step (II), the carbon black-containing before coagulation is contained.
  • the pH of the latex solution is 6.0 to 8.5.
  • step (I) of the present invention the carbon black, the dispersion solvent, and the rubber latex solution are mixed to produce a carbon black-containing rubber latex solution.
  • the step (I) comprises dispersing the carbon black in the dispersion solvent to produce a carbon black-containing slurry solution (hereinafter also referred to as a slurry solution) (I-a1) and It is preferable to include the step (I-b1) of producing a carbon black-containing rubber latex solution by mixing the obtained carbon black-containing slurry solution with the rubber latex solution.
  • the carbon black to which the rubber latex particles are attached by adding at least a part of the rubber latex solution when the carbon black is dispersed in the dispersion solvent in the step (I).
  • Step (I-a1) Examples of the method of mixing the carbon black and the dispersion solvent in the step (I-a1) include general methods such as high shear mixer, high shear mixer, homo mixer, homo mixer, ball mill, bead mill, high pressure homogenizer, ultrasonic homogenizer, colloid mill, etc. Of dispersing carbon black using a conventional dispersing machine.
  • the "high shear mixer” is a mixer including a rotor and a stator, and the rotor rotates in a state where a precise clearance is provided between the rotor capable of high speed rotation and the fixed stator.
  • a commercial item can be used for such a high shear mixer, For example, the "high shear mixer” by SILVERSON can be mentioned.
  • Step (I-a2) At the time of dispersing the carbon black in the dispersion solvent, at least a part of the rubber latex solution is added to produce a carbon black-containing slurry solution to which the rubber latex particles adhere.
  • the rubber latex solution may be mixed with a dispersion solvent in advance, and then carbon black may be added and dispersed.
  • carbon black may be added to the dispersion solvent, and then the carbon black may be dispersed in the dispersion solvent while adding the rubber latex solution at a predetermined addition rate, or carbon black may be added to the dispersion solvent. Then, the carbon black may be dispersed in the dispersing solvent while adding a constant amount of rubber latex solution in several divided portions.
  • the addition amount of the rubber latex solution in the step (I-a2) is 0.075 to the total amount of the rubber latex solution to be used (the total amount added in the step (I-a2) and the step (I-b2)). 12% by weight is exemplified.
  • the amount of rubber solid content of the rubber latex solution to be added is preferably 0.25 to 15% by weight ratio to carbon black, and is 0.5 to 6%. Is preferred.
  • the concentration of the rubber solids in the rubber latex solution to be added is preferably 0.2 to 5% by weight, and more preferably 0.5 to 1.5% by weight. In these cases, it is possible to produce a rubber wet masterbatch in which the degree of dispersion of carbon black is increased while the rubber latex particles are reliably attached to carbon black.
  • Step (I-b1) of the present invention the slurry solution and the rubber latex solution are mixed to produce a carbon black-containing rubber latex solution.
  • the method of mixing the slurry solution and the rubber latex solution in the liquid phase is not particularly limited, and the slurry solution and the rubber latex solution may be mixed, for example, with a high shear mixer, high shear mixer, homo mixer, homo mixer, ball mill, bead mill, Examples of the mixing method include a common disperser such as a high pressure homogenizer, an ultrasonic homogenizer, and a colloid mill, and a mixer using a mixer whose blades rotate in a cylindrical container. If necessary, the entire mixing system such as a dispersing machine may be heated during mixing.
  • the rubber latex solution preferably has a concentration of rubber solids of preferably 10 to 60% by weight, and more preferably 20 to 30% by weight, in consideration of dehydration time and labor in step (III) described later. It is more preferable that
  • Step (I-b2) In the step (I-b2), the carbon black-containing slurry solution to which the rubber latex particles are attached and the remaining rubber latex solution are mixed to produce a carbon black-containing rubber latex solution to which the rubber latex particles are attached.
  • the method of mixing the carbon black-containing slurry solution to which the rubber latex particles adhere and the remaining rubber latex solution in the liquid phase is the same as the method of mixing the slurry solution and the rubber latex solution in the liquid phase described above. The method is mentioned.
  • the remaining rubber latex solution preferably has a higher rubber solids concentration than the rubber latex solution added in step (I-a2), considering the dehydration time and labor in step (III) described later, Specifically, the concentration of rubber solids is preferably 10 to 60% by weight, and more preferably 20 to 30% by weight.
  • a surfactant may be added to improve the dispersibility of carbon black.
  • surfactants known in the rubber industry can be used.
  • nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, etc. Can be mentioned.
  • an alcohol such as ethanol may be used instead of the surfactant or in addition to the surfactant.
  • the surfactant is used, there is a concern that the final rubber physical properties of the vulcanized rubber may be reduced. Therefore, the blending amount of the surfactant is 100 parts by weight of the rubber solid content of the rubber latex solution. The amount is preferably 2 parts by weight or less, more preferably 1 part by weight or less, and it is preferable that the surfactant is not used substantially.
  • step (II) of the present invention the carbon black-containing rubber latex solution obtained above is coagulated to produce a carbon black-containing rubber coagulated product.
  • the pH of the carbon black-containing latex solution before coagulation is 6.0 to 8.5.
  • the pH of the carbon black-containing latex solution before coagulation is preferably 6.5 or more from the viewpoint of improving the ease of control of the size of the rubber wet masterbatch after coagulation, and in the rubber wet masterbatch From the viewpoint of improving the homogeneity of carbon black, 8.0 or less is preferable and 7.4 or less is more preferable.
  • the carbon black-containing rubber latex solution in the step (I) may be prepared appropriately.
  • Methods of heating, methods of vacuum degassing, methods of adding an acid such as formic acid, sulfuric acid, boric acid, citric acid, lactic acid and the like, and the like can be mentioned.
  • Examples of the method of coagulation include a method of incorporating a coagulant in the carbon black-containing rubber latex solution.
  • a coagulant an acid such as formic acid or sulfuric acid, a salt such as sodium chloride or the like that is usually used for coagulating a rubber latex solution can be used.
  • Step (III)> In the method for producing a rubber wet masterbatch of the present invention, it is preferable to provide a step (III) of dehydrating and drying the carbon black-containing rubber coagulated material obtained above.
  • various dehydration and drying apparatuses such as a single screw extruder, a twin screw extruder, a screw press, an oven, a conveyor type dryer, a vacuum dryer, an air dryer, can be used, for example .
  • a solid-liquid separation step using centrifugation or a vibrating screen may be provided before the step (III), for the purpose of appropriately reducing the amount of water contained in the carbon black-containing rubber coagulated material.
  • a washing process such as a water washing method may be provided.
  • the rubber wet masterbatch of the present invention is suitable for use in a rubber composition for tires because the carbon black contained therein has good dispersibility (homogeneity).
  • the method for producing a rubber composition for a tire according to the present invention includes the step (IV) of dry mixing using the rubber wet masterbatch obtained above.
  • various compounding agents can be further used.
  • examples of usable compounding agents include rubber, carbon black, sulfur-based vulcanizing agent, vulcanization accelerator, anti-aging agent, silica, silane coupling agent, zinc oxide, methylene acceptor and methylene donor, stearic acid
  • examples of such additives include vulcanization accelerators, vulcanization retarders, organic peroxides, softeners such as waxes and oils, and processing aids and the like, which are commonly used in the rubber industry.
  • the rubber is used separately from the rubber component derived from the rubber wet masterbatch.
  • the rubber include synthetic dienes such as natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR) and nitrile rubber (NBR). Rubber is mentioned.
  • the rubber may be used alone or in combination of two or more.
  • the weight ratio of the rubber component of the rubber latex solution in the wet master batch to the rubber (rubber component of the rubber latex solution / rubber) is the resistance of the vulcanized rubber From the viewpoint of improving physical properties such as abrasion, it is preferably 60/40 or more, more preferably 65/35 or more, and from the viewpoint of improving physical properties such as the abrasion resistance of vulcanized rubber, It is preferably 90/10 or less, more preferably 80/20 or less.
  • the weight ratio of the rubber component of the rubber latex solution in the wet master batch to the rubber (rubber component of the rubber latex solution / rubber) is fatigue resistance. Or more, preferably 40/60 or more, more preferably 45/55 or more, and 80/20 or less from the viewpoint of improving physical properties such as fatigue resistance. Is preferable and 60/40 or less is more preferable.
  • the sulfur as the sulfur-based vulcanizing agent may be any conventional sulfur for rubber, and for example, powder sulfur, precipitated sulfur, insoluble sulfur, highly dispersible sulfur and the like can be used.
  • the sulfur-based vulcanizing agent may be used alone or in combination of two or more.
  • the content of sulfur is preferably 0.3 to 6.5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition. If the content of sulfur is less than 0.3 parts by weight, the crosslink density of the vulcanized rubber will be insufficient to lower the rubber strength, etc. If it exceeds 6.5 parts by weight, both the heat resistance and the durability will be particularly good. Getting worse.
  • the sulfur content is 1.0 to 5.5 with respect to 100 parts by weight of the rubber component in the rubber composition. It is more preferable that it is a weight part.
  • any conventional vulcanization accelerator for rubber may be used, and a sulfenamide-based vulcanization accelerator, a thiuram-based vulcanization accelerator, a thiazole-based vulcanization accelerator, a thiourea-based vulcanization accelerator And guanidine-based vulcanization accelerators and dithiocarbamate-based vulcanization accelerators.
  • the vulcanization accelerators may be used alone or in combination of two or more.
  • the content of the vulcanization accelerator is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition.
  • the anti-aging agent may be any conventional anti-aging agent for rubber, such as aromatic amine based anti-aging agent, amine-ketone based anti-aging agent, monophenol based anti-aging agent, bisphenol based anti-aging agent, polyphenol based Antiaging agents, dithiocarbamate antiaging agents, thiourea antiaging agents, etc. may be mentioned.
  • the antioxidant may be used alone or in combination of two or more.
  • the content of the anti-aging agent is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition.
  • the method of blending (adding) the rubber wet masterbatch and the various compounding agents is, for example, using a kneader used in a usual rubber industry such as a Banbury mixer, a kneader, or a roll.
  • a knead used in a usual rubber industry such as a Banbury mixer, a kneader, or a roll.
  • mixing is mentioned.
  • the method of kneading is not particularly limited, for example, a method of adding and kneading components other than a vulcanizing component such as a sulfur-based vulcanizing agent and a vulcanization accelerator in any order, and a method of simultaneously adding and kneading Also, a method of simultaneously adding and kneading all the components may be mentioned.
  • the number of times of kneading may be one or more. Although the time for kneading varies depending on the size of the kneader used, etc., it may usually be about 2 to 5 minutes.
  • the discharge temperature of the kneader is preferably 120 to 170 ° C., and more preferably 120 to 150 ° C.
  • the discharge temperature of the kneader is preferably 80 to 110 ° C., more preferably 80 to 100 ° C., when the above-mentioned vulcanization system component is contained.
  • the rubber composition for a tire according to the present invention comprises each part of a pneumatic tire. In particular, it is suitable for tire treads. Moreover, according to the method for producing a rubber composition for a tire of the present invention, a vulcanized rubber having excellent low heat buildup and fatigue resistance can be obtained. Therefore, the rubber composition for a tire of the present invention is a pneumatic tire although it can be used at each site, it is particularly suitable for pre-papping.
  • Example 1 Preparation of rubber latex solution> Ammonia was added to the natural rubber latex concentrated latex solution at normal temperature so that the following mechanical stability was 1000 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight. [Measurement of mechanical stability of rubber latex solution] The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density
  • the rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above is added in an amount of 100 parts by weight of solid content (rubber) Were mixed using a SANYO household mixer SM-L 56 (mixer conditions: 11300 rpm, 1 minute) to produce a carbon black-containing rubber latex solution (step (I-b1)) ).
  • the carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
  • Examples 2 to 11 and Comparative Examples 1 to 3 In ⁇ Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to a value shown in Table 1, and ⁇ Step (I) of Example 1: Production of carbon black-containing rubber latex solution In ⁇ >, the carbon black to be used was changed to the type and blending amount shown in Table 1, and in ⁇ Step (II) of Example 1: Production of carbon black-containing rubber coagulant>, carbon black-containing before solidification. Rubber wet masterbatches of Examples 2 to 11 and Comparative Examples 1 to 3 were produced in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 1. In addition, the compounding quantity in Table 1 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
  • Example 12 In ⁇ Step (I): Preparation of Carbon Black-Containing Rubber Latex Solution> of Example 1, a part of the rubber latex solution was added (step (I-a2)), and the remaining rubber latex solution was added. A rubber wet masterbatch was produced in the same manner as in Example 1 except for (Step (I-b2)). In the step (I-a2), 0.5% by weight of the rubber latex solution is used based on the total amount of the rubber latex solution to be used (the total amount added in the step (I-a2) and the step (I-b2)). Added.
  • the difference between the carbon black content of the median sample and the carbon black content of the sample farthest from the median is less than 1 part by weight
  • The carbon black content of the median sample and the median
  • the difference between the carbon black content of the farthest sample and the carbon black content of the farthest sample is 1 part by weight or more and less than 2 parts by weight. But 2 parts by weight or more
  • Example 1 Preparation of rubber latex solution> Ammonia was added to the natural rubber latex-concentrated latex solution at room temperature so that the following mechanical stability was 600 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight. [Measurement of mechanical stability of rubber latex solution] The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density
  • the remaining carbon latex-containing slurry solution to which the rubber latex particles produced in the step (I-a2) have been adhered is treated with the remaining rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above.
  • the carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
  • Examples 2 to 10 and Comparative Examples 1 to 5 In ⁇ Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to the value shown in Table 2, and ⁇ Step (I) of Example 1: Production of carbon black-containing rubber latex solution In ⁇ >, the carbon black to be used was changed to the type and blending amount shown in Table 2, and in ⁇ Step (II) of Example 1: Production of carbon black-containing rubber coagulated substance>, carbon black-containing before solidification.
  • the rubber compositions and unvulcanized rubber compositions of Examples 2 to 10 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 2. Manufactured. In addition, the compounding quantity in Table 2 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
  • a vulcanized rubber was produced by vulcanizing the unvulcanized rubber compositions obtained in the above Examples and Comparative Examples under the conditions of 150 ° C. and 30 minutes. The following evaluation was performed about the obtained vulcanized rubber. The evaluation results are shown in Table 2.
  • Example 1 Preparation of rubber latex solution> Ammonia was added to the natural rubber latex-concentrated latex solution at room temperature so that the following mechanical stability was 600 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight. [Measurement of mechanical stability of rubber latex solution] The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density
  • the remaining carbon latex-containing slurry solution to which the rubber latex particles produced in the step (I-a2) have been adhered is treated with the remaining rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above.
  • the carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
  • Examples 2 to 10 and Comparative Examples 1 to 5 In ⁇ Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to a value shown in Table 3. Further, ⁇ Step (I) of Example 1: Production of carbon black-containing rubber latex solution In ⁇ >, the carbon black to be used was changed to the kind and compounding amount shown in Table 3, and in ⁇ Step (II) of Example 1: Production of carbon black-containing rubber coagulated material>, carbon black-containing before solidification.
  • the rubber compositions and unvulcanized rubber compositions of Examples 2 to 10 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 3. Manufactured.
  • the compounding quantity in Table 3 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
  • a vulcanized rubber was produced by vulcanizing the unvulcanized rubber compositions obtained in the above Examples and Comparative Examples under the conditions of 150 ° C. and 30 minutes. The following evaluation was performed about the obtained vulcanized rubber. The evaluation results are shown in Table 3.

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Abstract

A method for producing a rubber wet master batch which is obtained using at least a carbon black, a dispersion solvent and a rubber latex solution as starting materials. This method for producing a rubber wet master batch comprises: a step (I) for producing a carbon black-containing rubber latex solution by mixing the carbon black, the dispersion solvent and the rubber latex solution; and a step (II) for producing a carbon black-containing rubber coagulum by coagulating the thus-obtained carbon black-containing rubber latex solution. In the step (I), the mechanical stability of the rubber latex solution as determined in accordance with ASTM D1076-59 is 300 seconds or more; and in the step (II), the pH of the carbon black-containing latex solution before coagulation is from 6.0 to 8.5. The present invention is able to provide a method for producing a rubber wet master batch which has good dispersibility (homogeneity) of carbon black.

Description

ゴムウエットマスターバッチの製造方法、およびタイヤ用ゴム組成物の製造方法Method of producing rubber wet masterbatch, and method of producing rubber composition for tire
 本発明は、少なくともカーボンブラック、分散溶媒、およびゴムラテックス溶液を原料として得られるゴムウエットマスターバッチの製造方法に関する。また、本発明は、タイヤ用ゴム組成物の製造方法に関する。 The present invention relates to a method for producing a rubber wet masterbatch obtained using at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials. The present invention also relates to a method of producing a rubber composition for a tire.
 従来から、ゴム業界においては、カーボンブラックを含有するゴム組成物を製造する際の加工性やカーボンブラックの分散性を向上させるために、ゴムウエットマスターバッチを用いることが知られている。これは、カーボンブラックと分散溶媒とを予め一定の割合で混合し、機械的な力でカーボンブラックを分散溶媒中に分散させたカーボンブラック含有スラリー溶液と、ゴムラテックス溶液を液相で混合し、その後、酸などの凝固剤を加えて凝固させたもの(カーボンブラック含有ゴム凝固物)を回収して乾燥するものである。 Conventionally, in the rubber industry, it is known to use a rubber wet masterbatch in order to improve the processability at the time of producing a rubber composition containing carbon black and the dispersibility of carbon black. In this method, a carbon black-containing slurry solution in which carbon black and a dispersion solvent are mixed in advance at a constant ratio, and carbon black is dispersed in the dispersion solvent by mechanical force, and a rubber latex solution are mixed in a liquid phase, Thereafter, a coagulant such as an acid is added and solidified (carbon black-containing rubber coagulated material) is recovered and dried.
 ゴムウエットマスターバッチを用いる場合、カーボンブラックとゴムとを固相で混合して得られるゴムドライマスターバッチを用いる場合に比べて、カーボンブラックの分散性に優れ、加工性や補強性などのゴム物性に優れるゴム組成物が得られる。このようなゴム組成物を原料とすることで、例えば、転がり抵抗が低減され、耐疲労性に優れた空気入りタイヤなどのゴム製品(加硫ゴム)を製造することができる。 When a rubber wet masterbatch is used, it has excellent carbon black dispersibility and rubber physical properties such as processability and reinforcement, as compared with a rubber dry masterbatch obtained by mixing carbon black and rubber in a solid phase. The rubber composition which is excellent in is obtained. By using such a rubber composition as a raw material, for example, rolling resistance can be reduced, and a rubber product (vulcanized rubber) such as a pneumatic tire having excellent fatigue resistance can be manufactured.
 ゴムウエットマスターバッチの製造方法において、上記のカーボンブラック含有スラリー溶液の調製工程、あるいは上記のカーボンブラック含有ゴム凝固物の調製工程におけるpHを所定範囲に調整することで、耐摩耗性、低発熱性等のゴム特性が向上したゴム製品(加硫ゴム)が得られることが知られている(特許文献1~4)。 In the method for producing a rubber wet masterbatch, the abrasion resistance and low heat buildup can be achieved by adjusting the pH in the preparation step of the above-mentioned carbon black-containing slurry solution or the above-mentioned preparation step of the carbon black-containing rubber coagulated material to a predetermined range. It is known that rubber products (vulcanized rubber) having improved rubber properties such as are obtained (Patent Documents 1 to 4).
 また、ゴムウエットマスターバッチを含むゴム組成物から得られる空気入りタイヤなどのゴム製品(加硫ゴム)は、上記の転がり抵抗の低減、耐疲労性、低発熱性、耐摩耗性のほか、耐亀裂性などの耐引裂性に優れたものが要求されている(特許文献5、6)。 Moreover, rubber products (vulcanized rubber) such as pneumatic tires obtained from a rubber composition containing a rubber wet masterbatch have the above-mentioned reduction in rolling resistance, fatigue resistance, low heat buildup, wear resistance, and resistance What is excellent in tear resistance such as cracking is required (Patent Documents 5 and 6).
特開2006-328135号公報JP, 2006-328135, A 特開2007-197549号公報JP 2007-197549 特開2015-48416号公報JP, 2015-48416, A 特開2017-39881号公報JP, 2017-39881, A WO2010/123072号公報WO 2010/123072 特開2017-88747号公報JP 2017-88747 A
 上記の特許文献3および4に記載があるように、加硫ゴムの低発熱性、耐疲労性等のゴム特性を向上させるためには、ゴムウエットマスターバッチに含まれるカーボンブラックの分散性をさらに高めることが有効であると考えられる。しかし、上記の特許文献のようなゴムウエットマスターバッチから得られた加硫ゴムは、ゴムウエットマスターバッチに含まれるカーボンブラックの分散性(均質性)に改善の余地があることが判明した。 As described in Patent Documents 3 and 4 above, in order to improve rubber properties such as low heat buildup and fatigue resistance of vulcanized rubber, the dispersibility of carbon black contained in the rubber wet master batch is further increased. It is thought that raising is effective. However, it has been found that the vulcanized rubber obtained from the rubber wet masterbatch as in the above-mentioned patent documents has room for improvement in the dispersibility (homogeneity) of carbon black contained in the rubber wet masterbatch.
 また、上記の特許文献のようなゴムウエットマスターバッチを含むゴム組成物から得られた加硫ゴムは、耐摩耗性および耐引裂性に改善の余地があることが判明した。 It has also been found that vulcanized rubber obtained from a rubber composition containing a rubber wet masterbatch as in the above-mentioned patent documents has room for improvement in the abrasion resistance and tear resistance.
 また、上記の特許文献のようなゴムウエットマスターバッチを含むゴム組成物から得られた加硫ゴムは、とくに、プライトッピング(空気入りタイヤのカーカスプライやベルトプライにおけるコードを被覆する部材)に用いるための、低発熱性および耐疲労性に改善の余地があることが判明した。 Further, a vulcanized rubber obtained from a rubber composition containing a rubber wet masterbatch as in the above-mentioned patent documents is particularly used for pre-papping (member for covering a cord in a carcass ply of a pneumatic tire or a belt ply). It turned out that there is room for improvement in low heat build-up and fatigue resistance.
 本発明の第1の目的は、上記の実情に鑑みてなされたものであり、カーボンブラックの分散性(均質性)が良好なゴムウエットマスターバッチの製造方法を提供することである。 The first object of the present invention is made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a method for producing a rubber wet masterbatch having good dispersibility (homogeneity) of carbon black.
 また、本発明の第2の目的は、上記の実情に鑑みてなされたものであり、優れた耐摩耗性および耐引裂性を有する加硫ゴムが得られるタイヤ用ゴム組成物の製造方法を提供することである。 The second object of the present invention is made in view of the above situation, and provides a method for producing a rubber composition for a tire from which a vulcanized rubber having excellent abrasion resistance and tear resistance can be obtained. It is to be.
 また、本発明の第3の目的は、上記の実情に鑑みてなされたものであり、優れた低発熱性および耐疲労性を有する加硫ゴムが得られるプライトッピング用ゴム組成物の製造方法を提供することである。 Further, the third object of the present invention is made in view of the above-mentioned circumstances, and it is a method for producing a rubber composition for pretipping which can obtain a vulcanized rubber having excellent low heat buildup and fatigue resistance. It is to provide.
 本発明は、少なくともカーボンブラック、分散溶媒、およびゴムラテックス溶液を原料として得られるゴムウエットマスターバッチの製造方法であって、前記カーボンブラック、前記分散溶媒、および前記ゴムラテックス溶液を混合して、カーボンブラック含有ゴムラテックス溶液を製造する工程(I)と、得られたカーボンブラック含有ゴムラテックス溶液を凝固して、カーボンブラック含有ゴム凝固物を製造する工程(II)を含み、前記工程(I)において、ASTM D1076-59に準じて測定した、前記ゴムラテックス溶液の機械的安定性が、300秒以上であり、前記工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~8.5であることを特徴とするゴムウエットマスターバッチの製造方法、に関する。 The present invention is a method for producing a rubber wet masterbatch obtained using at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials, wherein the carbon black, the dispersion solvent, and the rubber latex solution are mixed to obtain carbon. Comprising a step (I) of producing a black-containing rubber latex solution and a step (II) of coagulating the obtained carbon black-containing rubber latex solution to produce a carbon black-containing rubber coagulated product, in the step (I) 5. The mechanical stability of the rubber latex solution measured according to ASTM D 1076-59 is 300 seconds or more, and in the step (II), the pH of the carbon black-containing latex solution before coagulation is 6. Rubber wet master bag characterized in that it is 0 to 8.5 Method of manufacture, related to.
 また、本発明は、さらに、前記ゴムウエットマスターバッチの製造方法で得られたゴムウエットマスターバッチを用いて、乾式混合する工程(IV)を含むことを特徴とするタイヤ用ゴム組成物の製造方法、に関する。 The present invention further includes a step (IV) of dry mixing using the rubber wet masterbatch obtained by the method of producing a rubber wet masterbatch, and a method of producing a rubber composition for a tire. About.
 本発明のゴムウエットマスターバッチの製造方法、およびタイヤ用ゴム組成物の製造方法における効果の作用メカニズムの詳細は不明な部分があるが、以下のように推定される。ただし、本発明は、この作用メカニズムに限定して解釈されなくてもよい。 The details of the effect mechanism in the method for producing the rubber wet masterbatch of the present invention and the method for producing the rubber composition for a tire are unclear, but are presumed as follows. However, the present invention may not be interpreted as being limited to this mechanism of action.
 本発明のゴムウエットマスターバッチの製造方法、およびタイヤ用ゴム組成物の製造方法では、上記のカーボンブラック含有ゴムラテックス溶液を製造する工程(I)において、ASTM D1076-59に準じて測定した前記ゴムラテックス溶液の機械的安定性が、300秒以上であり、かつ上記のカーボンブラック含有ゴム凝固物を製造する工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~8.5である。当該機械的安定性は、コロイド的安定性を示す指標であり、当該機械的安定性が小さいものは、小さな刺激でゴムラテックス粒子が凝集してしまう。このような機械的安定性が小さいゴムラテックス溶液を用いたカーボンブラック含有ゴムラテックス溶液を凝固した場合、ラテックス溶液中でカーボンブラックが均一に分散する前にラテックス粒子とカーボンブラックとの反応により凝固が起こってしまい、得られるゴムウエットマスターバッチ中のカーボンブラックの分散性(均質性)が不十分となってしまう。したがって、ゴムラテックス溶液の貯蔵安定性を高める観点、あるいは、ゴムラテックス溶液と、カーボンブラックおよび分散溶媒を含むカーボンブラック含有スラリー溶液とを安定的に混合する観点からは、当該機械的安定性が大きいゴムラテックス溶液が有利と考えられる。 In the method for producing a rubber wet masterbatch of the present invention and the method for producing a rubber composition for a tire, the rubber measured according to ASTM D 1076-59 in the step (I) for producing the carbon black-containing rubber latex solution described above The mechanical stability of the latex solution is 300 seconds or more, and in the step (II) of producing the carbon black-containing rubber coagulated product as described above, the pH of the carbon black-containing latex solution before coagulation is 6.0 to It is 8.5. The mechanical stability is an index showing colloidal stability, and in the case of the small mechanical stability, rubber latex particles are aggregated by a small stimulus. When coagulating a carbon black-containing rubber latex solution using a rubber latex solution having such small mechanical stability, coagulation occurs by the reaction between the latex particles and the carbon black before the carbon black is uniformly dispersed in the latex solution. As a result, the dispersibility (homogeneity) of the carbon black in the obtained rubber wet masterbatch becomes insufficient. Therefore, from the viewpoint of enhancing the storage stability of the rubber latex solution, or from the viewpoint of stably mixing the rubber latex solution and the carbon black-containing slurry solution containing carbon black and the dispersion solvent, the mechanical stability is high. A rubber latex solution is considered advantageous.
 しかし、当該機械的安定性が大きいゴムラテックス溶液を用いて得られたカーボンブラック含有ゴムラテックス溶液は、ラテックス粒子の安定性が高いため、ゴムラテックス粒子とカーボンブラックとの反応性が低く、当該溶液中のカーボンブラックの分散性が不十分となるものと推定される。このようなカーボンブラック含有ゴムラテックス溶液を凝固した場合、混合時のせん断や熱よる凝固がラテックス粒子とカーボンブラックとの反応による凝固よりも支配的に起こってしまい、得られるゴムウエットマスターバッチ中のカーボンブラックの分散性(均質性)が不十分となってしまう。 However, since the carbon black-containing rubber latex solution obtained by using the rubber latex solution having high mechanical stability has high stability of latex particles, the reactivity between the rubber latex particles and carbon black is low. It is estimated that the dispersibility of carbon black in the medium is insufficient. When such a carbon black-containing rubber latex solution is coagulated, coagulation due to shearing or heat during mixing occurs more dominantly than coagulation due to reaction between latex particles and carbon black, and the obtained rubber wet masterbatch The dispersibility (homogeneity) of carbon black will become inadequate.
 一方、上記のような機械的安定性が大きいゴムラテックス溶液を用いた場合においても、凝固剤による凝固前に、カーボンブラック含有ゴムラテックス溶液のpHを6.0~8.5の範囲に調整することにより、ゴムラテックス粒子とカーボンブラックとの反応性を最適に保つことができ、カーボンブラックの分散性を向上させることが可能である。さらに、その後の凝固工程において、急激な凝固を防止できるため、カーボンブラックがその分散性を維持しながら、ゴムラテックス粒子の凝固体に均質に取り込まれるものと推定される。その結果、カーボンブラックの分散性(均質性)が良好なゴムウエットマスターバッチが得られると考えられる。 On the other hand, even when using a rubber latex solution having high mechanical stability as described above, the pH of the carbon black-containing rubber latex solution is adjusted to a range of 6.0 to 8.5 before coagulation with a coagulant. Thus, the reactivity between the rubber latex particles and the carbon black can be kept optimum, and the dispersibility of the carbon black can be improved. Furthermore, since rapid solidification can be prevented in the subsequent solidification step, it is presumed that carbon black is uniformly incorporated into the coagulated body of the rubber latex particles while maintaining its dispersibility. As a result, it is considered that a rubber wet masterbatch having good carbon black dispersibility (homogeneity) can be obtained.
 このようなゴムウエットマスターバッチを含むゴム組成物は、当該ゴム組成物中のカーボンブラックの分散性(均質性)が良好になると推定されるため、得られる加硫ゴムは、耐摩耗性および耐引裂性、あるいは低発熱性および耐疲労性に優れる。 The rubber composition containing such a rubber wet masterbatch is presumed to have good dispersibility (homogeneity) of carbon black in the rubber composition, so that the resulting vulcanized rubber has excellent abrasion resistance and resistance. It is excellent in tearability or low heat buildup and fatigue resistance.
 本発明のゴムウエットマスターバッチの製造方法は、少なくともカーボンブラック、分散溶媒、およびゴムラテックス溶液を原料として使用する。 The method for producing a rubber wet masterbatch of the present invention uses at least carbon black, a dispersion solvent, and a rubber latex solution as raw materials.
 前記カーボンブラックとしては、例えば、SAF、ISAF、HAF、FEF、GPFなど、通常のゴム工業で使用されるカーボンブラックの他、アセチレンブラックやケッチェンブラックなどの導電性カーボンブラックを使用することができる。前記カーボンブラックは、通常のゴム工業において、そのハンドリング性を考慮して造粒された、造粒カーボンブラックであってもよく、未造粒カーボンブラックであってもよい。前記カーボンブラックは、単独で用いてもよく2種類以上を併用してもよい。 As said carbon black, conductive carbon blacks, such as acetylene black and ketjen black, can be used besides carbon black used by usual rubber industry, such as SAF, ISAF, HAF, FEF, GPF, for example. . The carbon black may be granulated carbon black or non-granulated carbon black which is granulated in consideration of its handling property in ordinary rubber industry. The carbon black may be used alone or in combination of two or more.
 前記カーボンブラックは、加硫ゴムの耐摩耗性を向上させる観点から、窒素吸着比表面積が、50m/g以上であることが好ましく、60m/g以上であることがより好ましく、70m/g以上であることがさらに好ましく、そして、200m/g以下であることが好ましく、190m/g以下であることがより好ましく、180m/g以下であることがさらに好ましい。また、前記カーボンブラックは、加硫ゴムの低発熱性を向上させる観点から、窒素吸着比表面積が、20m/g以上であることが好ましく、25m/g以上であることがより好ましく、30m/g以上であることがさらに好ましく、そして、100m/g以下であることが好ましく、95m/g以下であることがより好ましく、90m/g以下であることがさらに好ましい。 The carbon black, from the viewpoint of improving the wear resistance of the vulcanized rubber, the nitrogen adsorption specific surface area, is preferably 50 m 2 / g or more, more preferably 60 m 2 / g or more, 70m 2 / more preferably g or more, and is preferably at 200 meters 2 / g or less, more preferably 190 m 2 / g or less, and more preferably not more than 180 m 2 / g. The carbon black preferably has a nitrogen adsorption specific surface area of 20 m 2 / g or more, more preferably 25 m 2 / g or more, from the viewpoint of improving the low heat buildup of the vulcanized rubber, and more preferably 30 m. still more preferably 2 / g or more, and is preferably from 100 m 2 / g, more preferably 95 m 2 / g or less, and more preferably not more than 90m 2 / g.
 前記カーボンブラックの含有量は、加硫ゴムの補強性を向上させる観点から、ゴム組成物に含まれるゴム成分100重量部に対して、20~100重量部であることが好ましく、30~90重量部であることがより好ましく、40~80重量部であることがさらに好ましい。また、前記カーボンブラックの含有量は、加硫ゴムの補強性を向上させる観点から、ゴムウエットマスターバッチに含まれるゴム成分100重量部に対して、10~100重量部であることが好ましく、15~90重量部であることがより好ましく、20~80重量部であることがさらに好ましい。 The content of the carbon black is preferably 20 to 100 parts by weight, preferably 30 to 90 parts by weight, with respect to 100 parts by weight of the rubber component contained in the rubber composition, from the viewpoint of improving the reinforcing property of the vulcanized rubber. It is more preferably part, and still more preferably 40 to 80 parts by weight. The content of the carbon black is preferably 10 to 100 parts by weight with respect to 100 parts by weight of the rubber component contained in the rubber wet master batch, from the viewpoint of improving the reinforcing property of the vulcanized rubber. The amount is more preferably 90 parts by weight, further preferably 20 to 80 parts by weight.
 前記分散溶媒としては、特に水を使用することが好ましいが、例えば、有機溶媒を含有する水であってもよい。前記分散溶媒は、単独で用いてもよく2種類以上を併用してもよい。 Water is particularly preferably used as the dispersion solvent, but it may be, for example, water containing an organic solvent. The dispersion solvents may be used alone or in combination of two or more.
 前記ゴムラテックス溶液としては、天然ゴムラテックス溶液および合成ゴムラテックス溶液を使用することができる。 As the rubber latex solution, a natural rubber latex solution and a synthetic rubber latex solution can be used.
 前記天然ゴムラテックス溶液は、植物の代謝作用による天然の生産物であり、特に分散溶媒が水である、天然ゴム/水系のものが好ましい。前記天然ゴムラテックス中に含まれる天然ゴムの数平均分子量は、200万以上であることが好ましく、250万以上であることがより好ましい。前記天然ゴムラテックス溶液としては、濃縮ラテックス、フィールドラテックスといわれる新鮮ラテックスなど区別なく使用できる。前記合成ゴムラテックス溶液としては、例えば、スチレン-ブタジエンゴム、ブタジエンゴム、ニトリルゴム、クロロプレンゴムを乳化重合により製造したものが挙げられる。前記ゴムラテックス溶液は、単独で用いてもよく2種類以上を併用してもよい。 The natural rubber latex solution is a natural product produced by the metabolism of plants, and a natural rubber / water system in which the dispersion solvent is water is particularly preferable. The number average molecular weight of the natural rubber contained in the natural rubber latex is preferably 2,000,000 or more, and more preferably 2,500,000 or more. As the natural rubber latex solution, concentrated latex, fresh latex called field latex, etc. can be used without distinction. Examples of the synthetic rubber latex solution include those prepared by emulsion polymerization of styrene-butadiene rubber, butadiene rubber, nitrile rubber and chloroprene rubber. The rubber latex solution may be used alone or in combination of two or more.
 前記ゴムラテックス溶液は、ASTM D1076-59に準じて測定した、機械的安定性(機械的安定度ともいう)が、300秒以上である。前記機械的安定性は、貯蔵安定性を向上させる観点およびゴムウエットマスターバッチ中のカーボンブラックの均質性を向上させる観点から、300秒以上であることが好ましく、400秒以上であることがより好ましい。前記機械的安定性は、ASTM D1076-59に準じ、回転板を所定の回転数で撹拌させたときにラテックス中に凝固物が発見されるまでの時間により求められる。なお、前記機械的安定性は、上限値として、例えば、3600秒以下、2400秒以下が例示される。 The rubber latex solution has a mechanical stability (also referred to as mechanical stability) of 300 seconds or more, which is measured according to ASTM D 1076-59. The mechanical stability is preferably 300 seconds or more, more preferably 400 seconds or more, from the viewpoint of improving the storage stability and the viewpoint of improving the homogeneity of carbon black in the rubber wet masterbatch. . The mechanical stability is determined according to ASTM D 1076-59 by the time until a coagulated substance is found in the latex when the rotating plate is agitated at a predetermined rotation speed. The mechanical stability is exemplified by, for example, 3600 seconds or less and 2400 seconds or less as the upper limit value.
 前記機械的安定性は、アンモニア、水酸化ナトリウム、水酸化カリウムなどの塩基性化合物;サリチル酸ナトリウムなどの芳香族カルボン酸塩;ラウリン酸アンモニウムなどの長鎖脂肪酸塩;ギ酸、酢酸、プロピオン酸などの短鎖脂肪酸;などの調整剤を、原料のゴムラテックス溶液に添加することにより上記の範囲に調整することができる。これらの中でも、アンモニアを使用することが好ましい。これら調整剤を使用する場合、前記ゴムラテックス溶液の濃度に制限はないが、ゴムラテックス溶液の安定化の観点から、ゴムラテックス溶液は調製後12時間以上たってから使用するのが好ましい。 The above-mentioned mechanical stability includes basic compounds such as ammonia, sodium hydroxide and potassium hydroxide; aromatic carboxylic acid salts such as sodium salicylate; long-chain fatty acid salts such as ammonium laurate; formic acid, acetic acid, propionic acid and the like Adjustment agents such as short-chain fatty acids; and the like can be adjusted to the above range by adding them to the raw material rubber latex solution. Among these, it is preferable to use ammonia. When these modifiers are used, the concentration of the rubber latex solution is not limited, but from the viewpoint of stabilization of the rubber latex solution, it is preferable to use the rubber latex solution after 12 hours or more after preparation.
 以下に、本発明のゴムウエットマスターバッチの製造方法について具体的に説明する。かかる製造方法は、前記カーボンブラック、前記分散溶媒、および前記ゴムラテックス溶液を混合して、カーボンブラック含有ゴムラテックス溶液を製造する工程(I)と、得られたカーボンブラック含有ゴムラテックス溶液を凝固して、カーボンブラック含有ゴム凝固物を製造する工程(II)を含む。また、前記工程(I)において、ASTM D1076-59に準じて測定した、前記ゴムラテックス溶液の機械的安定性が、300秒以上であり、前記工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~8.5である。 Below, the manufacturing method of the rubber | gum wet masterbatch of this invention is demonstrated concretely. The production method comprises the step (I) of mixing the carbon black, the dispersion solvent, and the rubber latex solution to produce a carbon black-containing rubber latex solution, and coagulating the obtained carbon black-containing rubber latex solution And the step (II) of producing a carbon black-containing rubber coagulated product. In the step (I), the mechanical stability of the rubber latex solution measured according to ASTM D 1076-59 is 300 seconds or more, and in the step (II), the carbon black-containing before coagulation is contained. The pH of the latex solution is 6.0 to 8.5.
<工程(I)>
 本発明の工程(I)では、前記カーボンブラック、前記分散溶媒、および前記ゴムラテックス溶液を混合して、カーボンブラック含有ゴムラテックス溶液を製造する。特に、本発明においては、前記工程(I)が、前記カーボンブラックを前記分散溶媒中に分散させて、カーボンブラック含有スラリー溶液(以下、スラリー溶液ともいう)を製造する工程(I-a1)と、得られたカーボンブラック含有スラリー溶液と、前記ゴムラテックス溶液とを混合して、カーボンブラック含有ゴムラテックス溶液を製造する工程(I-b1)を含むことが好ましい。また、本発明においては、前記工程(I)が、前記カーボンブラックを前記分散溶媒中に分散させる際に、前記ゴムラテックス溶液の少なくとも一部を添加することにより、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造する工程(I-a2)と、得られたゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液と、残りの前記ゴムラテックス溶液とを混合して、ゴムラテックス粒子が付着したカーボンブラック含有ゴムラテックス溶液を製造する工程(I-b2)を含むこともできる。
<Step (I)>
In step (I) of the present invention, the carbon black, the dispersion solvent, and the rubber latex solution are mixed to produce a carbon black-containing rubber latex solution. In particular, in the present invention, the step (I) comprises dispersing the carbon black in the dispersion solvent to produce a carbon black-containing slurry solution (hereinafter also referred to as a slurry solution) (I-a1) and It is preferable to include the step (I-b1) of producing a carbon black-containing rubber latex solution by mixing the obtained carbon black-containing slurry solution with the rubber latex solution. In the present invention, the carbon black to which the rubber latex particles are attached by adding at least a part of the rubber latex solution when the carbon black is dispersed in the dispersion solvent in the step (I). A step (I-a2) of producing a containing slurry solution, a carbon black containing slurry solution to which the obtained rubber latex particles are attached, and the remaining rubber latex solution are mixed to obtain carbon black to which rubber latex particles are attached. It is also possible to include the step (I-b2) of producing the rubber latex solution containing it.
<工程(I-a1)>
 前記工程(I-a1)において、カーボンブラックおよび分散溶媒を混合する方法としては、例えば、高せん断ミキサー、ハイシアーミキサー、ホモミキサー、ボールミル、ビーズミル、高圧ホモジナイザー、超音波ホモジナイザー、コロイドミルなどの一般的な分散機を使用してカーボンブラックを分散させる方法が挙げられる。
<Step (I-a1)>
Examples of the method of mixing the carbon black and the dispersion solvent in the step (I-a1) include general methods such as high shear mixer, high shear mixer, homo mixer, homo mixer, ball mill, bead mill, high pressure homogenizer, ultrasonic homogenizer, colloid mill, etc. Of dispersing carbon black using a conventional dispersing machine.
 前記「高せん断ミキサー」とは、ローターとステーターとを備えるミキサーであって、高速回転が可能なローターと、固定されたステーターと、の間に精密なクリアランスを設けた状態でローターが回転することにより、高せん断作用が働くミキサーを意味する。このような高せん断作用を生み出すためには、ローターとステーターとのクリアランスを0.8mm以下とし、ローターの周速を5m/s以上とすることが好ましい。このような高せん断ミキサーは、市販品を使用することができ、例えば、SILVERSON社製「ハイシアーミキサー」が挙げられる。 The "high shear mixer" is a mixer including a rotor and a stator, and the rotor rotates in a state where a precise clearance is provided between the rotor capable of high speed rotation and the fixed stator. Means a mixer with high shear action. In order to produce such high shear action, it is preferable to set the clearance between the rotor and the stator to 0.8 mm or less and to set the circumferential speed of the rotor to 5 m / s or more. A commercial item can be used for such a high shear mixer, For example, the "high shear mixer" by SILVERSON can be mentioned.
<工程(I-a2)>
 前記工程(I-a2)では、カーボンブラックを分散溶媒中に分散させる際に、ゴムラテックス溶液の少なくとも一部を添加することにより、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造する。ゴムラテックス溶液は、あらかじめ分散溶媒と混合した後、カーボンブラックを添加し、分散させても良い。また、分散溶媒中にカーボンブラックを添加し、次いで所定の添加速度で、ゴムラテックス溶液を添加しつつ、分散溶媒中でカーボンブラックを分散させても良く、あるいは分散溶媒中にカーボンブラックを添加し、次いで何回かに分けて一定量のゴムラテックス溶液を添加しつつ、分散溶媒中でカーボンブラックを分散させても良い。ゴムラテックス溶液が存在する状態で、分散溶媒中にカーボンブラックを分散させることにより、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造することができる。工程(I-a2)におけるゴムラテックス溶液の添加量としては、使用するゴムラテックス溶液の全量(工程(I-a2)および工程(I-b2)で添加する全量)に対して、0.075~12重量%が例示される。
<Step (I-a2)>
In the step (I-a2), at the time of dispersing the carbon black in the dispersion solvent, at least a part of the rubber latex solution is added to produce a carbon black-containing slurry solution to which the rubber latex particles adhere. The rubber latex solution may be mixed with a dispersion solvent in advance, and then carbon black may be added and dispersed. Alternatively, carbon black may be added to the dispersion solvent, and then the carbon black may be dispersed in the dispersion solvent while adding the rubber latex solution at a predetermined addition rate, or carbon black may be added to the dispersion solvent. Then, the carbon black may be dispersed in the dispersing solvent while adding a constant amount of rubber latex solution in several divided portions. By dispersing carbon black in the dispersion solvent in the presence of the rubber latex solution, it is possible to produce a carbon black-containing slurry solution to which rubber latex particles adhere. The addition amount of the rubber latex solution in the step (I-a2) is 0.075 to the total amount of the rubber latex solution to be used (the total amount added in the step (I-a2) and the step (I-b2)). 12% by weight is exemplified.
 前記工程(I-a2)では、添加するゴムラテックス溶液のゴム固形分の量が、カーボンブラックとの重量比で0.25~15%であることが好ましく、0.5~6%であることが好ましい。また、添加するゴムラテックス溶液中のゴム固形分の濃度が、0.2~5重量%であることが好ましく、0.5~1.5重量%であることがより好ましい。これらの場合、ゴムラテックス粒子をカーボンブラックに確実に付着させつつ、カーボンブラックの分散度合いを高めたゴムウエットマスターバッチを製造することができる。 In the step (I-a2), the amount of rubber solid content of the rubber latex solution to be added is preferably 0.25 to 15% by weight ratio to carbon black, and is 0.5 to 6%. Is preferred. In addition, the concentration of the rubber solids in the rubber latex solution to be added is preferably 0.2 to 5% by weight, and more preferably 0.5 to 1.5% by weight. In these cases, it is possible to produce a rubber wet masterbatch in which the degree of dispersion of carbon black is increased while the rubber latex particles are reliably attached to carbon black.
 前記工程(I-a2)において、ゴムラテックス溶液存在下でカーボンブラックおよび分散溶媒を混合する方法としては、上述したカーボンブラックおよび分散溶媒を混合する方法と同様の方法が挙げられる。 As the method of mixing the carbon black and the dispersion solvent in the presence of the rubber latex solution in the step (I-a2), the same method as the method of mixing the carbon black and the dispersion solvent described above can be mentioned.
<工程(I-b1)>
 本発明の工程(I-b1)では、前記スラリー溶液と、ゴムラテックス溶液とを混合して、カーボンブラック含有ゴムラテックス溶液を製造する。スラリー溶液と、ゴムラテックス溶液とを液相で混合する方法は特に限定されるものではなく、スラリー溶液およびゴムラテックス溶液とを、例えば、高せん断ミキサー、ハイシアーミキサー、ホモミキサー、ボールミル、ビーズミル、高圧ホモジナイザー、超音波ホモジナイザー、コロイドミルなどの一般的な分散機や円筒状容器内でブレードが回転する混合機を使用して混合する方法が挙げられる。必要に応じて、混合の際に分散機などの混合系全体を加温してもよい。
<Step (I-b1)>
In the step (I-b1) of the present invention, the slurry solution and the rubber latex solution are mixed to produce a carbon black-containing rubber latex solution. The method of mixing the slurry solution and the rubber latex solution in the liquid phase is not particularly limited, and the slurry solution and the rubber latex solution may be mixed, for example, with a high shear mixer, high shear mixer, homo mixer, homo mixer, ball mill, bead mill, Examples of the mixing method include a common disperser such as a high pressure homogenizer, an ultrasonic homogenizer, and a colloid mill, and a mixer using a mixer whose blades rotate in a cylindrical container. If necessary, the entire mixing system such as a dispersing machine may be heated during mixing.
 前記ゴムラテックス溶液は、後述する工程(III)での脱水時間・労力を考慮した場合、具体的には、ゴム固形分の濃度が10~60重量%であることが好ましく、20~30重量%であることがより好ましい。 The rubber latex solution preferably has a concentration of rubber solids of preferably 10 to 60% by weight, and more preferably 20 to 30% by weight, in consideration of dehydration time and labor in step (III) described later. It is more preferable that
<工程(I-b2)>
 前記工程(I-b2)では、前記ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液と、残りのゴムラテックス溶液とを混合して、ゴムラテックス粒子が付着したカーボンブラック含有ゴムラテックス溶液を製造する。前記ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液と、残りのゴムラテックス溶液とを液相で混合する方法は、上述した、スラリー溶液と、ゴムラテックス溶液とを液相で混合する方法と同様の方法が挙げられる。
<Step (I-b2)>
In the step (I-b2), the carbon black-containing slurry solution to which the rubber latex particles are attached and the remaining rubber latex solution are mixed to produce a carbon black-containing rubber latex solution to which the rubber latex particles are attached. The method of mixing the carbon black-containing slurry solution to which the rubber latex particles adhere and the remaining rubber latex solution in the liquid phase is the same as the method of mixing the slurry solution and the rubber latex solution in the liquid phase described above. The method is mentioned.
 前記残りのゴムラテックス溶液は、後述する工程(III)での脱水時間・労力を考慮した場合、工程(I-a2)で添加したゴムラテックス溶液よりもゴム固形分の濃度が高いことが好ましく、具体的には、ゴム固形分の濃度が10~60重量%であることが好ましく、20~30重量%であることがより好ましい。 The remaining rubber latex solution preferably has a higher rubber solids concentration than the rubber latex solution added in step (I-a2), considering the dehydration time and labor in step (III) described later, Specifically, the concentration of rubber solids is preferably 10 to 60% by weight, and more preferably 20 to 30% by weight.
 なお、前記工程(I)では、カーボンブラックの分散性向上のために界面活性剤を添加しても良い。前記界面活性剤としては、ゴム業界において公知の界面活性剤を使用することができ、例えば、非イオン性界面活性剤、アニオン系界面活性剤、カチオン系界面活性剤、両イオン系界面活性剤などが挙げられる。また、前記界面活性剤に代えて、あるいは前記界面活性剤に加えて、エタノールなどのアルコールを使用しても良い。ただし、前記界面活性剤を使用した場合、最終的な加硫ゴムのゴム物性が低下することが懸念されるため、前記界面活性剤の配合量は、前記ゴムラテックス溶液のゴム固形分量100重量部に対して、2重量部以下であることが好ましく、1重量部以下であることがより好ましく、実質的に前記界面活性剤を使用しないことが好ましい。 In the step (I), a surfactant may be added to improve the dispersibility of carbon black. As the surfactant, surfactants known in the rubber industry can be used. For example, nonionic surfactants, anionic surfactants, cationic surfactants, zwitterionic surfactants, etc. Can be mentioned. Also, instead of the surfactant or in addition to the surfactant, an alcohol such as ethanol may be used. However, when the surfactant is used, there is a concern that the final rubber physical properties of the vulcanized rubber may be reduced. Therefore, the blending amount of the surfactant is 100 parts by weight of the rubber solid content of the rubber latex solution. The amount is preferably 2 parts by weight or less, more preferably 1 part by weight or less, and it is preferable that the surfactant is not used substantially.
<工程(II)>
 本発明の工程(II)では、上記で得られたカーボンブラック含有ゴムラテックス溶液を凝固して、カーボンブラック含有ゴム凝固物を製造する。また、本発明においては、前記工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~8.5である。前記凝固前の前記カーボンブラック含有ラテックス溶液のpHは、凝固後のゴムウエットマスターバッチの大きさの制御の容易さを向上させる観点から、6.5以上が好ましく、そして、ゴムウエットマスターバッチ中のカーボンブラックの均質性を向上させる観点から、8.0以下が好ましく、7.4以下がより好ましい。
<Step (II)>
In step (II) of the present invention, the carbon black-containing rubber latex solution obtained above is coagulated to produce a carbon black-containing rubber coagulated product. In the present invention, in the step (II), the pH of the carbon black-containing latex solution before coagulation is 6.0 to 8.5. The pH of the carbon black-containing latex solution before coagulation is preferably 6.5 or more from the viewpoint of improving the ease of control of the size of the rubber wet masterbatch after coagulation, and in the rubber wet masterbatch From the viewpoint of improving the homogeneity of carbon black, 8.0 or less is preferable and 7.4 or less is more preferable.
 前記凝固前のカーボンブラック含有ラテックス溶液において、当該溶液のpHを6.0~8.5に調整する方法としては、前記工程(I)における前記カーボンブラック含有ゴムラテックス溶液を製造する際に、適宜、加熱する方法、減圧脱気する方法、ギ酸、硫酸、ホウ酸、クエン酸、乳酸などの酸を添加する方法、などが挙げられる。 As a method of adjusting the pH of the carbon black-containing latex solution before coagulation to 6.0 to 8.5, the carbon black-containing rubber latex solution in the step (I) may be prepared appropriately. Methods of heating, methods of vacuum degassing, methods of adding an acid such as formic acid, sulfuric acid, boric acid, citric acid, lactic acid and the like, and the like can be mentioned.
 前記凝固の方法としては、前記カーボンブラック含有ゴムラテックス溶液中に、凝固剤を含有させる方法が挙げられる。前記凝固剤としては、ゴムラテックス溶液の凝固用として通常使用される、ギ酸、硫酸などの酸;塩化ナトリウムなどの塩;などを使用することができる。 Examples of the method of coagulation include a method of incorporating a coagulant in the carbon black-containing rubber latex solution. As the coagulant, an acid such as formic acid or sulfuric acid, a salt such as sodium chloride or the like that is usually used for coagulating a rubber latex solution can be used.
<工程(III)>
 本発明のゴムウエットマスターバッチの製造方法においては、上記で得られたカーボンブラック含有ゴム凝固物を脱水・乾燥する工程(III)を設けることが好ましい。前記脱水・乾燥の方法としては、例えば、単軸押出機、二軸押出機、スクリュープレス、オーブン、コンベヤー式乾燥機、真空乾燥機、エアードライヤーなどの各種脱水・乾燥装置を使用することができる。なお、工程(III)の前に、必要に応じて、カーボンブラック含有ゴム凝固物が含む水分量を適度に低減する目的として、例えば、遠心分離や振動スクリーンを使用した固液分離工程を設けてもよく、あるいは、洗浄を目的として、水洗法などの洗浄工程などを設けてもよい。
<Step (III)>
In the method for producing a rubber wet masterbatch of the present invention, it is preferable to provide a step (III) of dehydrating and drying the carbon black-containing rubber coagulated material obtained above. As a method of the said dehydration and drying, various dehydration and drying apparatuses, such as a single screw extruder, a twin screw extruder, a screw press, an oven, a conveyor type dryer, a vacuum dryer, an air dryer, can be used, for example . Before the step (III), for the purpose of appropriately reducing the amount of water contained in the carbon black-containing rubber coagulated material, for example, a solid-liquid separation step using centrifugation or a vibrating screen may be provided. Alternatively, for the purpose of cleaning, a washing process such as a water washing method may be provided.
 本発明のゴムウエットマスターバッチは、含有するカーボンブラックが良好な分散性(均質性)を有するため、タイヤ用ゴム組成物の使用に適している。 The rubber wet masterbatch of the present invention is suitable for use in a rubber composition for tires because the carbon black contained therein has good dispersibility (homogeneity).
<工程(IV)>
 本発明のタイヤ用ゴム組成物の製造方法は、上記で得られたゴムウエットマスターバッチを用いて、乾式混合する工程(IV)を含む。
<Step (IV)>
The method for producing a rubber composition for a tire according to the present invention includes the step (IV) of dry mixing using the rubber wet masterbatch obtained above.
 前記工程(IV)では、さらに、各種配合剤を用いることができる。使用可能な配合剤としては、例えば、ゴム、カーボンブラック、硫黄系加硫剤、加硫促進剤、老化防止剤、シリカ、シランカップリング剤、酸化亜鉛、メチレン受容体およびメチレン供与体、ステアリン酸、加硫促進助剤、加硫遅延剤、有機過酸化物、ワックスやオイルなどの軟化剤、加工助剤などの通常ゴム工業で使用される配合剤が挙げられる。 In the step (IV), various compounding agents can be further used. Examples of usable compounding agents include rubber, carbon black, sulfur-based vulcanizing agent, vulcanization accelerator, anti-aging agent, silica, silane coupling agent, zinc oxide, methylene acceptor and methylene donor, stearic acid Examples of such additives include vulcanization accelerators, vulcanization retarders, organic peroxides, softeners such as waxes and oils, and processing aids and the like, which are commonly used in the rubber industry.
 前記ゴムは、前記ゴムウエットマスターバッチ由来のゴム成分とは別に使用されるものである。前記ゴムとしては、例えば、天然ゴム(NR)や、イソプレンゴム(IR)、スチレン-ブタジエンゴム(SBR)、ブタジエンゴム(BR)、クロロプレンゴム(CR)、ニトリルゴム(NBR)などの合成ジエン系ゴムが挙げられる。ゴムは、単独で用いてもよく2種類以上を併用してもよい。 The rubber is used separately from the rubber component derived from the rubber wet masterbatch. Examples of the rubber include synthetic dienes such as natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR) and nitrile rubber (NBR). Rubber is mentioned. The rubber may be used alone or in combination of two or more.
 前記ゴムは、加硫ゴムに耐引裂性、あるいは耐疲労性を付与する観点から、合成ジエン系ゴムを用いることが好ましく、合成ジエン系ゴムとしては、SBR、BRを用いることが好ましい。 From the viewpoint of imparting tear resistance or fatigue resistance to the vulcanized rubber, it is preferable to use a synthetic diene rubber, and as the synthetic diene rubber, it is preferable to use SBR or BR.
 前記工程(IV)において、前記ゴムを使用する場合、前記ウエットマスターバッチ中のゴムラテックス溶液のゴム成分と、前記ゴムの重量比(ゴムラテックス溶液のゴム成分/ゴム)は、加硫ゴムの耐摩耗性等の物性を向上させる観点から、60/40以上であることが好ましく、65/35以上であることがより好ましく、そして、加硫ゴムの耐摩耗性等の物性を向上させる観点から、90/10以下であることが好ましく、80/20以下であることがより好ましい。また、前記工程(IV)において、前記ゴムを使用する場合、前記ウエットマスターバッチ中のゴムラテックス溶液のゴム成分と、前記ゴムの重量比(ゴムラテックス溶液のゴム成分/ゴム)は、耐疲労性等の物性を向上させる観点から、40/60以上であることが好ましく、45/55以上であることがより好ましく、そして、耐疲労性等の物性を向上させる観点から、80/20以下であることが好ましく、60/40以下であることがより好ましい。 In the step (IV), when using the rubber, the weight ratio of the rubber component of the rubber latex solution in the wet master batch to the rubber (rubber component of the rubber latex solution / rubber) is the resistance of the vulcanized rubber From the viewpoint of improving physical properties such as abrasion, it is preferably 60/40 or more, more preferably 65/35 or more, and from the viewpoint of improving physical properties such as the abrasion resistance of vulcanized rubber, It is preferably 90/10 or less, more preferably 80/20 or less. In the step (IV), when the rubber is used, the weight ratio of the rubber component of the rubber latex solution in the wet master batch to the rubber (rubber component of the rubber latex solution / rubber) is fatigue resistance. Or more, preferably 40/60 or more, more preferably 45/55 or more, and 80/20 or less from the viewpoint of improving physical properties such as fatigue resistance. Is preferable and 60/40 or less is more preferable.
 前記硫黄系加硫剤としての硫黄は、通常のゴム用硫黄であればよく、例えば、粉末硫黄、沈降硫黄、不溶性硫黄、高分散性硫黄などを用いることができる。硫黄系加硫剤は、単独で用いてもよく2種類以上を併用してもよい。 The sulfur as the sulfur-based vulcanizing agent may be any conventional sulfur for rubber, and for example, powder sulfur, precipitated sulfur, insoluble sulfur, highly dispersible sulfur and the like can be used. The sulfur-based vulcanizing agent may be used alone or in combination of two or more.
 前記硫黄の含有量は、ゴム組成物中のゴム成分100重量部に対して0.3~6.5重量部であることが好ましい。硫黄の含有量が0.3重量部未満であると、加硫ゴムの架橋密度が不足してゴム強度などが低下し、6.5重量部を超えると、特に耐熱性および耐久性の両方が悪化する。加硫ゴムのゴム強度を良好に確保し、耐熱性と耐久性をより向上するためには、硫黄の含有量がゴム組成物中のゴム成分100重量部に対して1.0~5.5重量部であることがより好ましい。 The content of sulfur is preferably 0.3 to 6.5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition. If the content of sulfur is less than 0.3 parts by weight, the crosslink density of the vulcanized rubber will be insufficient to lower the rubber strength, etc. If it exceeds 6.5 parts by weight, both the heat resistance and the durability will be particularly good. Getting worse. In order to ensure the rubber strength of the vulcanized rubber favorably and to further improve the heat resistance and durability, the sulfur content is 1.0 to 5.5 with respect to 100 parts by weight of the rubber component in the rubber composition. It is more preferable that it is a weight part.
 前記加硫促進剤としては、通常のゴム用加硫促進剤であればよく、スルフェンアミド系加硫促進剤、チウラム系加硫促進剤、チアゾール系加硫促進剤、チオウレア系加硫促進剤、グアニジン系加硫促進剤、ジチオカルバミン酸塩系加硫促進剤などが挙げられる。加硫促進剤は、単独で用いてもよく2種類以上を併用してもよい。 As the vulcanization accelerator, any conventional vulcanization accelerator for rubber may be used, and a sulfenamide-based vulcanization accelerator, a thiuram-based vulcanization accelerator, a thiazole-based vulcanization accelerator, a thiourea-based vulcanization accelerator And guanidine-based vulcanization accelerators and dithiocarbamate-based vulcanization accelerators. The vulcanization accelerators may be used alone or in combination of two or more.
 前記加硫促進剤の含有量は、ゴム組成物中のゴム成分100重量部に対して1~5重量部であることが好ましい。 The content of the vulcanization accelerator is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition.
 前記老化防止剤としては、通常のゴム用老化防止剤であればよく、芳香族アミン系老化防止剤、アミン-ケトン系老化防止剤、モノフェノール系老化防止剤、ビスフェノール系老化防止剤、ポリフェノール系老化防止剤、ジチオカルバミン酸塩系老化防止剤、チオウレア系老化防止剤などが挙げられる。老化防止剤は、単独で用いてもよく2種類以上を併用してもよい。 The anti-aging agent may be any conventional anti-aging agent for rubber, such as aromatic amine based anti-aging agent, amine-ketone based anti-aging agent, monophenol based anti-aging agent, bisphenol based anti-aging agent, polyphenol based Antiaging agents, dithiocarbamate antiaging agents, thiourea antiaging agents, etc. may be mentioned. The antioxidant may be used alone or in combination of two or more.
 前記老化防止剤の含有量は、ゴム組成物中のゴム成分100重量部に対して1~5重量部であることが好ましい。 The content of the anti-aging agent is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition.
 前記工程(IV)において、前記ゴムウエットマスターバッチ、および前記各種配合剤の配合(添加)の方法は、例えば、バンバリーミキサー、ニーダー、ロールなどの通常のゴム工業において使用される混練機を用いて混練する方法が挙げられる。 In the step (IV), the method of blending (adding) the rubber wet masterbatch and the various compounding agents is, for example, using a kneader used in a usual rubber industry such as a Banbury mixer, a kneader, or a roll. The method of knead | mixing is mentioned.
 前記混練する方法は特に限定されないが、例えば、硫黄系加硫剤および加硫促進剤などの加硫系成分以外の成分を、任意の順序で添加し混練する方法、同時に添加して混練する方法、また、全成分を同時に添加して混練する方法などが挙げられる。また、混練する回数は、1回または複数回であってもよい。混練する時間は、使用する混練機の大きさなどによって異なるが、通常、2~5分程度とすればよい。また、混練機の排出温度は、120~170℃とすることが好ましく、120~150℃とすることがより好ましい。なお、混練機の排出温度は、前記加硫系成分を含む場合、80~110℃とすることが好ましく、80~100℃とすることがより好ましい。 Although the method of kneading is not particularly limited, for example, a method of adding and kneading components other than a vulcanizing component such as a sulfur-based vulcanizing agent and a vulcanization accelerator in any order, and a method of simultaneously adding and kneading Also, a method of simultaneously adding and kneading all the components may be mentioned. The number of times of kneading may be one or more. Although the time for kneading varies depending on the size of the kneader used, etc., it may usually be about 2 to 5 minutes. The discharge temperature of the kneader is preferably 120 to 170 ° C., and more preferably 120 to 150 ° C. The discharge temperature of the kneader is preferably 80 to 110 ° C., more preferably 80 to 100 ° C., when the above-mentioned vulcanization system component is contained.
 本発明のタイヤ用ゴム組成物の製造方法によれば、優れた耐摩耗性および耐引裂性を有する加硫ゴムが得られるため、本発明のタイヤ用ゴム組成物は、空気入りタイヤの各部位に使用できるが、とくに、タイヤトレッド用に適している。また、本発明のタイヤ用ゴム組成物の製造方法によれば、優れた低発熱性および耐疲労性を有する加硫ゴムが得られるため、本発明のタイヤ用ゴム組成物は、空気入りタイヤの各部位に使用できるが、とくに、プライトッピング用に適している。 According to the method for producing a rubber composition for a tire according to the present invention, a vulcanized rubber having excellent abrasion resistance and tear resistance can be obtained. Therefore, the rubber composition for a tire according to the present invention comprises each part of a pneumatic tire. In particular, it is suitable for tire treads. Moreover, according to the method for producing a rubber composition for a tire of the present invention, a vulcanized rubber having excellent low heat buildup and fatigue resistance can be obtained. Therefore, the rubber composition for a tire of the present invention is a pneumatic tire Although it can be used at each site, it is particularly suitable for pre-papping.
 以下に実施例をあげて本発明を説明するが、本発明はこれら実施例によりなんら限定されるものではない。 EXAMPLES The present invention will be described by way of examples, but the present invention is not limited by these examples.
 以下、第1の目的にかかる実施形態について説明する。 Hereinafter, an embodiment according to the first object will be described.
 (表1における使用原料)
a)カーボンブラック:
 カーボンブラック「N134」(窒素吸着比表面積143m/g)、(東海カーボン社製)
 カーボンブラック「N234」(窒素吸着比表面積126m/g)、(東海カーボン社製)
 カーボンブラック「N339」(窒素吸着比表面積93m/g)、(東海カーボン社製)
 カーボンブラック「N550」(窒素吸着比表面積42m/g)、(東海カーボン社製)
 カーボンブラック「N774」(窒素吸着比表面積27m/g)、(東海カーボン社製)
b)分散溶媒:水
c)ゴムラテックス溶液:
 天然ゴム濃縮ラテックス溶液(Dry Rubber Contentが60重量%)、(レヂテックス社製)
d)凝固剤:ギ酸(一級85%、10%溶液に希釈して、pH1.2に調整したもの)、(ナカライテスク社製)
(Raw materials used in Table 1)
a) Carbon black:
Carbon black "N134" (nitrogen adsorption specific surface area 143 m 2 / g), (Tokai Carbon Co., Ltd.)
Carbon black "N234" (nitrogen adsorption specific surface area 126 m 2 / g), (Tokai Carbon Co., Ltd.)
Carbon black "N339" (nitrogen adsorption specific surface area 93 m 2 / g), (Tokai Carbon Co., Ltd.)
Carbon black "N550" (nitrogen adsorption specific surface area 42 m 2 / g), (Tokai Carbon Co., Ltd.)
Carbon black "N774" (nitrogen adsorption specific surface area 27 m 2 / g), (Tokai Carbon Co., Ltd.)
b) dispersion solvent: water c) rubber latex solution:
Natural rubber concentrated latex solution (60% by weight of Dry Rubber Content), (made by Redex)
d) Coagulant: Formic acid (diluted to a primary grade 85%, 10% solution and adjusted to pH 1.2), (Nacalai Tesque)
<実施例1>
<ゴムラテックス溶液の調整>
 天然ゴムラテックス濃縮ラテックス溶液に、以下の機械安定性が1000秒となるように、常温下でアンモニアを加えた。次いで常温で水を加えて、ゴム成分が25重量%のゴムラテックス溶液を調製した。
[ゴムラテックス溶液の機械安定性の測定]
 ゴムラテックス溶液の機械安定性の測定は、ASTM D1076-59に準じ、14000rpmにて回転板を回転させてラテックス中に目視にて明らかな凝固物が発見されるまでの時間(秒)を計測した。なお、当該測定におけるゴムラテックス溶液中のゴム固形分の濃度は60重量%である。
Example 1
<Preparation of rubber latex solution>
Ammonia was added to the natural rubber latex concentrated latex solution at normal temperature so that the following mechanical stability was 1000 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight.
[Measurement of mechanical stability of rubber latex solution]
The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density | concentration of rubber | gum solid content in the rubber latex solution in the said measurement is 60 weight%.
<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>
 水に、カーボンブラック「N234」を50重量部添加し、これにPRIMIX社製ロボミックスを使用してカーボンブラックを分散させることにより(該ロボミックスの条件:9000rpm、30分)、固形分5重量%のカーボンブラック含有スラリー溶液を製造した(工程(I-a1))。次に、工程(I-a1)で製造したカーボンブラックスラリー溶液に、上記で得られた所定の機械安定性を有するゴムラテックス溶液(25重量%)を、固形分(ゴム)量が100重量部となるように添加し、次いでSANYO社製家庭用ミキサーSM-L56型を使用して混合し(ミキサー条件:11300rpm、1分)、カーボンブラック含有ゴムラテックス溶液を製造した(工程(I-b1))。
<Step (I): Production of Carbon Black-Containing Rubber Latex Solution>
50 parts by weight of carbon black "N234" is added to water, and carbon black is dispersed therein using Robomix made by PRIMIX (the conditions of the Robomix: 9000 rpm, 30 minutes), solid content 5 weight % Carbon black-containing slurry solution was produced (step (I-a1)). Next, to the carbon black slurry solution produced in step (I-a1), the rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above is added in an amount of 100 parts by weight of solid content (rubber) Were mixed using a SANYO household mixer SM-L 56 (mixer conditions: 11300 rpm, 1 minute) to produce a carbon black-containing rubber latex solution (step (I-b1)) ).
<工程(II):カーボンブラック含有ゴム凝固物の製造>
 上記の工程(I)で製造したカーボンブラック含有ゴムラテックス溶液に、ギ酸(10%)を溶液全体がpH7.2となるまで添加し、SANYO社製家庭用ミキサーSM-L56型を使用してさらに混合を行った(ミキサー条件:11300rpm、25分)。次いで、凝固剤として、ギ酸(10%溶液)を溶液全体がpH4となるまで添加し、さらにSANYO社製家庭用ミキサーSM-L56型を使用することで(ミキサー条件:11300rpm、2分)、カーボンブラック含有ゴム凝固物を製造した(工程(II))。なお、pHは、JIS Z8802準拠し、東亜ディーケーケー(株)製、「ポータブルpH計HM-30P」を用いて、評価した。
<Step (II): Production of carbon black-containing rubber coagulated material>
Formic acid (10%) is added to the carbon black-containing rubber latex solution produced in the above step (I) until the whole solution reaches a pH of 7.2, and it is further added using SANYO's household mixer SM-L56. Mixing was performed (mixer conditions: 11300 rpm, 25 minutes). Then, formic acid (10% solution) is added as a coagulant until the whole solution reaches pH 4, and furthermore, by using SANYO's household mixer SM-L56 type (mixer conditions: 11300 rpm, 2 minutes), carbon A black-containing rubber coagulum was produced (step (II)). The pH was evaluated according to JIS Z8802 using "Portable pH meter HM-30P" manufactured by Toa DKK Co., Ltd.
<工程(III):ゴムウエットマスターバッチの製造>
 上記の工程(II)で製造したカーボンブラック含有ゴム凝固物を、スクイザー式1軸押出脱水機(スエヒロEPM社製V-02型)で水分率が1.5%以下になるまで脱水および乾燥することにより、ゴムウエットマスターバッチを製造した(工程(III))。
<Step (III): Production of Rubber Wet Masterbatch>
The carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
<実施例2~11および比較例1~3>
 実施例1の<ゴムラテックス溶液の調製>において、ゴムラテックスの機械安定性を表1に示す値に変更したこと、また、実施例1の<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>において、使用するカーボンブラックを表1に示す種類および配合量に変更したこと、また、実施例1の<工程(II):カーボンブラック含有ゴム凝固物の製造>において、凝固前のカーボンブラック含有ゴムラテックス溶液のpHを表1に示す値に変更したこと以外は、実施例1と同様の方法により、実施例2~11および比較例1~3のゴムウエットマスターバッチを製造した。なお、表1中の配合量は、ゴムウエットマスターバッチに含まれるゴム成分の全量を100重量部としたときの重量部(phr)で示す。
Examples 2 to 11 and Comparative Examples 1 to 3
In <Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to a value shown in Table 1, and <Step (I) of Example 1: Production of carbon black-containing rubber latex solution In <>, the carbon black to be used was changed to the type and blending amount shown in Table 1, and in <Step (II) of Example 1: Production of carbon black-containing rubber coagulant>, carbon black-containing before solidification. Rubber wet masterbatches of Examples 2 to 11 and Comparative Examples 1 to 3 were produced in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 1. In addition, the compounding quantity in Table 1 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
<実施例12>
 実施例1の<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>において、ゴムラテックス溶液の一部を加えたこと(工程(I-a2))、また、残りのゴムラテックス溶液を加えたこと(工程(I-b2))以外は、実施例1と同様の方法により、ゴムウエットマスターバッチを製造した。なお、工程(I-a2)において、使用するゴムラテックス溶液の全量(工程(I-a2)および工程(I-b2)で添加する全量)に対して、0.5重量%のゴムラテックス溶液を添加した。
Example 12
In <Step (I): Preparation of Carbon Black-Containing Rubber Latex Solution> of Example 1, a part of the rubber latex solution was added (step (I-a2)), and the remaining rubber latex solution was added. A rubber wet masterbatch was produced in the same manner as in Example 1 except for (Step (I-b2)). In the step (I-a2), 0.5% by weight of the rubber latex solution is used based on the total amount of the rubber latex solution to be used (the total amount added in the step (I-a2) and the step (I-b2)). Added.
 上記の実施例及び比較例で得られた、カーボンブラック含有ゴム凝固物およびゴムウエットマスターバッチについて以下の評価を行った。評価結果を表1に示す。 The following evaluations were performed on the carbon black-containing rubber coagulated material and the rubber wet masterbatch obtained in the above-described Examples and Comparative Examples. The evaluation results are shown in Table 1.
<カーボンブラック含有ゴム凝固物の大きさの評価>
 上記の工程(II)で製造したカーボンブラック含有ゴム凝固物を、無作為に20個サンプリングし、各サンプルの最大幅を測定して、それらの平均値を算出し、以下の基準にて評価した。下記評価が◎の場合、工程(III)でのハンドリング性に優れることを示す。
 ◎:平均値が5mm以上50mm未満
 〇:平均値が50mm以上100mm未満
 ×:平均値が5mm未満、あるいは100mm以上
<Evaluation of size of carbon black-containing rubber coagulated material>
The carbon black-containing rubber coagulated material produced in the above step (II) was randomly sampled 20 pieces, the maximum width of each sample was measured, the average value thereof was calculated, and the following criteria were evaluated. . When the following evaluation is ◎, it shows that it is excellent in the handling property in process (III).
:: Average value is 5 mm or more and less than 50 mm ○: Average value is 50 mm or more and less than 100 mm ×: Average value is less than 5 mm, or 100 mm or more
<カーボンブラックの分散性(均質性)の評価>
 カーボンブラックの分散性(均質性)の評価は、上記の工程(III)で製造したゴムウエットマスターバッチを、無作為に3個サンプリングし、各サンプルを熱重量・示差熱分析装置(TG/DTA)を用い、窒素雰囲気下で、常温から650℃に昇温させたのち、650℃(一定)で15分、空気雰囲気下650℃(一定)で15分加熱し、窒素雰囲気下と空気雰囲気下との重量の減少量(重量損失率)から、ゴムウエットマスターバッチ中のカーボンブラックの割合(含有量)を算出し、以下の基準にて評価した。
 〇:中央値のサンプルのカーボンブラック含有量と、中央値から最も離れたサンプルのカーボンブラック含有量との差が、1重量部未満
 △:中央値のサンプルのカーボンブラック含有量と、中央値から最も離れたサンプルのカーボンブラック含有量との差が、1重量部以上2重量部未満
 ×:中央値のサンプルのカーボンブラック含有量と、中央値から最も離れたサンプルのカーボンブラック含有量との差が、2重量部以上
<Evaluation of dispersibility (homogeneity) of carbon black>
For evaluation of the dispersibility (homogeneity) of carbon black, three samples of the rubber wet masterbatch produced in the above step (III) were sampled at random, and each sample was subjected to thermogravimetric / differential thermal analysis (TG / DTA) ), And after raising the temperature from normal temperature to 650 ° C under nitrogen atmosphere, heat for 15 minutes at 650 ° C (constant), 15 minutes under air atmosphere at 650 ° C (constant), under nitrogen atmosphere and air atmosphere The proportion (content) of carbon black in the rubber wet masterbatch was calculated from the amount of weight loss (weight loss rate) and was evaluated according to the following criteria.
:: The difference between the carbon black content of the median sample and the carbon black content of the sample farthest from the median is less than 1 part by weight Δ: The carbon black content of the median sample and the median The difference between the carbon black content of the farthest sample and the carbon black content of the farthest sample is 1 part by weight or more and less than 2 parts by weight. But 2 parts by weight or more
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
 以下、第2の目的にかかる実施形態について説明する。 Hereinafter, an embodiment according to the second object will be described.
 (表2における使用原料)
a)カーボンブラック:
 カーボンブラック「N234(シースト7HM)」、(東海カーボン社製)
 カーボンブラック「N110(シースト9)」、(東海カーボン社製)
 カーボンブラック「N339(シーストKH)」、(東海カーボン社製)
b)分散溶媒:水
c)ゴムラテックス溶液:
 天然ゴム濃縮ラテックス溶液(Dry Rubber Contentが60重量%)、(レヂテックス社製)
d)凝固剤:ギ酸(一級85%、10%溶液に希釈して、pH1.2に調整したもの)、(ナカライテスク社製)
e)ジエン系ゴム:「BR150B」(宇部興産製)
f)酸化亜鉛:「3号亜鉛華」(三井金属鉱業社製)
g)ステアリン酸:「ビーズステアリン酸」(日油社製)
h)ワックス:「OZOACE0355」(日本精蝋社製)
i)老化防止剤(A):N-フェニル-N’-(1,3-ジメチルブチル)-p-フェニレンジアミン、「6PPD」(モンサント社製)
j)老化防止剤(B):2,2,4-トリメチル-1,2-ジヒドロキノリン重合体、「RD」、(大内新興化学社製)
k)硫黄:「5%油入微粉末硫黄」(鶴見化学工業社製)
l)加硫促進剤(A):N-シクロヘキシル-2-ベンゾチアゾールスルフェンアミド、「サンセラーCM」、(三新化学工業社製)
m)加硫促進剤(B):1,3-ジフェニルグアニジン、「ノクセラーD」、(大内新興化学社製)
(Raw materials used in Table 2)
a) Carbon black:
Carbon black "N234 (Seat 7HM)" (made by Tokai Carbon Co., Ltd.)
Carbon black "N110 (Seat 9)" (made by Tokai Carbon Co., Ltd.)
Carbon black "N339 (Seat KH)" (made by Tokai Carbon Co., Ltd.)
b) dispersion solvent: water c) rubber latex solution:
Natural rubber concentrated latex solution (60% by weight of Dry Rubber Content), (made by Redex)
d) Coagulant: Formic acid (diluted to a primary grade 85%, 10% solution and adjusted to pH 1.2), (Nacalai Tesque)
e) Diene rubber: "BR150B" (made by Ube Industries, Ltd.)
f) Zinc oxide: "No. 3 zinc flower" (manufactured by Mitsui Mining & Smelting Co., Ltd.)
g) Stearic acid: "Beads stearic acid" (manufactured by NOF Corporation)
h) Wax: "OZOACE 0355" (manufactured by Nippon Seiwa Co., Ltd.)
i) Anti-aging agent (A): N-phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine, "6PPD" (manufactured by Monsanto)
j) Anti-aging agent (B): 2,2,4-trimethyl-1,2-dihydroquinoline polymer, "RD", (made by Ouchi New Chemical Co., Ltd.)
k) Sulfur: "5% oil-filled fine powder sulfur" (made by Tsurumi Chemical Industry Co., Ltd.)
l) Vulcanization accelerator (A): N-cyclohexyl-2-benzothiazole sulfenamide, "Sunseller CM", (manufactured by Sanshin Chemical Industry Co., Ltd.)
m) Vulcanization accelerator (B): 1,3-diphenylguanidine, "Noxceler D", (made by Ouchi New Chemical Co., Ltd.)
<実施例1>
<ゴムラテックス溶液の調整>
 天然ゴムラテックス濃縮ラテックス溶液に、以下の機械安定性が600秒となるように、常温下でアンモニアを加えた。次いで常温で水を加えて、ゴム成分が25重量%のゴムラテックス溶液を調製した。
[ゴムラテックス溶液の機械安定性の測定]
 ゴムラテックス溶液の機械安定性の測定は、ASTM D1076-59に準じ、14000rpmにて回転板を回転させてラテックス中に目視にて明らかな凝固物が発見されるまでの時間(秒)を計測した。なお、当該測定におけるゴムラテックス溶液中のゴム固形分の濃度は60重量%である。
Example 1
<Preparation of rubber latex solution>
Ammonia was added to the natural rubber latex-concentrated latex solution at room temperature so that the following mechanical stability was 600 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight.
[Measurement of mechanical stability of rubber latex solution]
The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density | concentration of rubber | gum solid content in the rubber latex solution in the said measurement is 60 weight%.
<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>
 上記で得られた所定の機械安定性を有するゴムラテックス溶液に水を加え、濃度0.5重量%ゴム希薄ラテックス水溶液を調製した。得られたゴム希薄ラテックス水溶液に、カーボンブラック「N234」を50重量部(ラテックス溶液の固形分量(ゴム量)が、カーボンブラックとの重量比で1重量部)添加し、これにPRIMIX社製ロボミックスを使用してカーボンブラックを分散させることにより(該ロボミックスの条件:9000rpm、30分)、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造した(工程(I-a2))。次に、工程(I-a2)で製造したゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液に、残りの上記で得られた所定の機械安定性を有するゴムラテックス溶液(25重量%)を、工程(I-a2)で使用したゴム希薄ラテックス水溶液と合わせて、固形分(ゴム)量が100重量部となるように添加し、次いでSANYO社製家庭用ミキサーSM-L56型を使用して混合し(ミキサー条件11300rpm、30分)、ゴムラテックス粒子が付着したカーボンブラック含有ゴムラテックス溶液を製造した(工程(I-b2))。
<Step (I): Production of Carbon Black-Containing Rubber Latex Solution>
Water was added to the rubber latex solution having the predetermined mechanical stability obtained above to prepare a 0.5 wt% rubber dilute latex aqueous solution. To the obtained rubber dilute latex aqueous solution, 50 parts by weight of carbon black "N234" (the solid content (rubber amount) of the latex solution is 1 part by weight relative to carbon black) is added, and to this ROMIBO manufactured by PRIMIX The carbon black-containing slurry solution to which rubber latex particles were attached was produced by dispersing carbon black using the mix (conditions of the robot mix: 9000 rpm, 30 minutes) (step (I-a2)). Next, the remaining carbon latex-containing slurry solution to which the rubber latex particles produced in the step (I-a2) have been adhered is treated with the remaining rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above. Add together with the rubber dilute latex aqueous solution used in (I-a2) so that the solid content (rubber) amount is 100 parts by weight, and then mix using a SANYO household mixer SM-L56. (Mixer conditions 11300 rpm, 30 minutes) A carbon black-containing rubber latex solution to which rubber latex particles were attached was produced (step (I-b2)).
<工程(II):カーボンブラック含有ゴム凝固物の製造>
 上記の工程(I)で製造したカーボンブラック含有ゴムラテックス溶液に、ギ酸(10%)を溶液全体がpH7.2となるまで添加し、SANYO社製家庭用ミキサーSM-L56型を使用してさらに混合を行った(ミキサー条件:11300rpm、25分)。次いで、凝固剤として、ギ酸(10%溶液)を溶液全体がpH4となるまで添加し、さらにSANYO社製家庭用ミキサーSM-L56型を使用することで(ミキサー条件:11300rpm、2分)、カーボンブラック含有ゴム凝固物を製造した(工程(II))。なお、pHは、JIS Z8802準拠し、東亜ディーケーケー(株)製、「ポータブルpH計HM-30P」を用いて、評価した。
<Step (II): Production of carbon black-containing rubber coagulated material>
Formic acid (10%) is added to the carbon black-containing rubber latex solution produced in the above step (I) until the whole solution reaches a pH of 7.2, and it is further added using SANYO's household mixer SM-L56. Mixing was performed (mixer conditions: 11300 rpm, 25 minutes). Then, formic acid (10% solution) is added as a coagulant until the whole solution reaches pH 4, and furthermore, by using SANYO's household mixer SM-L56 type (mixer conditions: 11300 rpm, 2 minutes), carbon A black-containing rubber coagulum was produced (step (II)). The pH was evaluated according to JIS Z8802 using "Portable pH meter HM-30P" manufactured by Toa DKK Co., Ltd.
<工程(III):ゴムウエットマスターバッチの製造>
 上記の工程(II)で製造したカーボンブラック含有ゴム凝固物を、スクイザー式1軸押出脱水機(スエヒロEPM社製V-02型)で水分率が1.5%以下になるまで脱水および乾燥することにより、ゴムウエットマスターバッチを製造した(工程(III))。
<Step (III): Production of Rubber Wet Masterbatch>
The carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
<工程(IV):ゴム組成物および未加硫ゴム組成物の製造>
 上記で得られたゴムウエットマスターバッチと、表2に記載の各原料(硫黄と加硫促進剤を除く成分)を、バンバリーミキサーを用いて乾式混合(混練時間:3分、排出温度:150℃)することにより、ゴム組成物を製造した。次いで、得られたゴム組成物に、表2に記載の硫黄、加硫促進剤(A)および加硫促進剤(B)を加え、バンバリーミキサーを用いて乾式混合(混練時間:1分、排出温度:90℃)することにより、未加硫ゴム組成物を製造した。なお、表2中の配合比率は、ゴム組成物に含まれるゴム成分の全量を100重量部としたときの重量部(phr)で示す。
<Step (IV): Production of Rubber Composition and Unvulcanized Rubber Composition>
Dry mixing (mixing time: 3 minutes, discharge temperature: 150 ° C.) of the rubber wet master batch obtained above and each raw material listed in Table 2 (components other than sulfur and vulcanization accelerator) using a Banbury mixer The rubber composition was manufactured by carrying out. Next, the sulfur, vulcanization accelerator (A) and vulcanization accelerator (B) listed in Table 2 are added to the obtained rubber composition, and dry mixing (kneading time: 1 minute, discharge using a Banbury mixer) The unvulcanized rubber composition was manufactured by carrying out temperature: 90 degreeC. In addition, the compounding ratio in Table 2 is shown by the weight part (phr) when the whole quantity of the rubber component contained in a rubber composition is 100 weight part.
<実施例2~10および比較例1~5>
 実施例1の<ゴムラテックス溶液の調製>において、ゴムラテックスの機械安定性を表2に示す値に変更したこと、また、実施例1の<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>において、使用するカーボンブラックを表2に示す種類および配合量に変更したこと、また、実施例1の<工程(II):カーボンブラック含有ゴム凝固物の製造>において、凝固前のカーボンブラック含有ゴムラテックス溶液のpHを表2に示す値に変更したこと以外は、実施例1と同様の方法により、実施例2~10および比較例1~5のゴム組成物および未加硫ゴム組成物を製造した。なお、表2中の配合量は、ゴムウエットマスターバッチに含まれるゴム成分の全量を100重量部としたときの重量部(phr)で示す。
Examples 2 to 10 and Comparative Examples 1 to 5
In <Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to the value shown in Table 2, and <Step (I) of Example 1: Production of carbon black-containing rubber latex solution In <>, the carbon black to be used was changed to the type and blending amount shown in Table 2, and in <Step (II) of Example 1: Production of carbon black-containing rubber coagulated substance>, carbon black-containing before solidification. The rubber compositions and unvulcanized rubber compositions of Examples 2 to 10 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 2. Manufactured. In addition, the compounding quantity in Table 2 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
 上記の実施例及び比較例で得られた未加硫ゴム組成物を、150℃、30分間の条件で加硫することにより、加硫ゴムを製造した。得られた加硫ゴムについて以下の評価を行った。評価結果を表2に示す。 A vulcanized rubber was produced by vulcanizing the unvulcanized rubber compositions obtained in the above Examples and Comparative Examples under the conditions of 150 ° C. and 30 minutes. The following evaluation was performed about the obtained vulcanized rubber. The evaluation results are shown in Table 2.
<耐摩耗性の評価>
 耐摩耗性の評価は、得られた加硫ゴムの試験片において、JIS K6264に準拠して、岩本製作所(株)製のランボーン摩耗試験機を用いて、荷重40N、スリップ率30%、温度23℃、落砂量20g/分で摩耗減量を測定し、実施例1~6、9、および10、ならびに比較例2~3は比較例1の値を100とした指数、実施例7は比較例4の値を100とした指数、実施例8は比較例5の値を100とした指数で表示した。指数が小さいほど、摩耗減量が少なく、耐摩耗性に優れることを示す。
<Evaluation of wear resistance>
The evaluation of the abrasion resistance was carried out on a test piece of the obtained vulcanized rubber according to JIS K6264 using a Rambone abrasion tester manufactured by Iwamoto Seisakusho Co., Ltd., load 40 N, slip ratio 30%, temperature 23 The abrasion loss was measured at 20 ° C and the amount of sand fall at 20 g / min, and Examples 1 to 6, 9, and 10, and Comparative Examples 2 to 3 are indexes with the value of Comparative Example 1 being 100, and Example 7 is a Comparative Example The value of 4 was set to 100, and the value of Example 8 was set to 100 as the value of Comparative Example 5. The smaller the index, the smaller the loss on wear and the better the wear resistance.
<耐引裂性の評価>
 耐引裂性の評価は、JIS K6252規定のクレセント形で、上記で得られた加硫ゴムを打ち抜き、くぼみの中央に0.50±0.08mmの切れ込みを入れたサンプルを得た。島津製作所の引張り試験機によって500mm/minの引張り速度で引裂強度を測定し、実施例1~6、9、および10、ならびに比較例2~3は比較例1の値を100とした指数、実施例7は比較例4の値を100とした指数、実施例8は比較例5の値を100とした指数で表示した。指数が大きいほど、耐引裂性に優れることを示す。
<Evaluation of tear resistance>
In the evaluation of tear resistance, the vulcanized rubber obtained above was punched out in a crescent form defined in JIS K6252 to obtain a sample in which a cut of 0.50 ± 0.08 mm was inserted in the center of the recess. The tear strength was measured at a tensile speed of 500 mm / min with a Shimadzu tensile tester, and Examples 1 to 6, 9, and 10, and Comparative Examples 2 to 3 are indices with the value of Comparative Example 1 being 100, Implementation Example 7 was expressed as an index with the value of Comparative Example 4 being 100, and Example 8 was expressed as an index with the value of Comparative Example 5 being 100. The larger the index, the better the tear resistance.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 以下、第3の目的にかかる実施形態について説明する。 Hereinafter, an embodiment according to the third object will be described.
 (表3における使用原料)
a)カーボンブラック:
 カーボンブラック「N339(シーストKH)」、(東海カーボン社製)
 カーボンブラック「N550(シーストSO)」、(東海カーボン社製)
 カーボンブラック「N774(シーストS)」、(東海カーボン社製)
b)分散溶媒:水
c)ゴムラテックス溶液:
 天然ゴム濃縮ラテックス溶液(Dry Rubber Contentが60重量%)、(レヂテックス社製)
d)凝固剤:ギ酸(一級85%、10%溶液に希釈して、pH1.2に調整したもの)、(ナカライテスク社製)
e)ジエン系ゴム:「BR150B」(宇部興産製)
f)酸化亜鉛:「3号亜鉛華」(三井金属鉱業社製)
g)ステアリン酸:「ビーズステアリン酸」(日油社製)
h)ワックス:「OZOACE0355」(日本精蝋社製)
i)老化防止剤(A):N-フェニル-N’-(1,3-ジメチルブチル)-p-フェニレンジアミン、「6PPD」(モンサント社製)
j)老化防止剤(B):2,2,4-トリメチル-1,2-ジヒドロキノリン重合体、「RD」、(大内新興化学社製)
k)硫黄:「5%油入微粉末硫黄」(鶴見化学工業社製)
l)加硫促進剤(A):N-シクロヘキシル-2-ベンゾチアゾールスルフェンアミド、「サンセラーCM」、(三新化学工業社製)
m)加硫促進剤(B):1,3-ジフェニルグアニジン、「ノクセラーD」、(大内新興化学社製)
(Raw materials used in Table 3)
a) Carbon black:
Carbon black "N339 (Seat KH)" (made by Tokai Carbon Co., Ltd.)
Carbon black "N550 (Seat SO)" (made by Tokai Carbon Co., Ltd.)
Carbon black "N 774 (Seat S)" (made by Tokai Carbon Co., Ltd.)
b) dispersion solvent: water c) rubber latex solution:
Natural rubber concentrated latex solution (60% by weight of Dry Rubber Content), (made by Redex)
d) Coagulant: Formic acid (diluted to a primary grade 85%, 10% solution and adjusted to pH 1.2), (Nacalai Tesque)
e) Diene rubber: "BR150B" (made by Ube Industries, Ltd.)
f) Zinc oxide: "No. 3 zinc flower" (manufactured by Mitsui Mining & Smelting Co., Ltd.)
g) Stearic acid: "Beads stearic acid" (manufactured by NOF Corporation)
h) Wax: "OZOACE 0355" (manufactured by Nippon Seiwa Co., Ltd.)
i) Anti-aging agent (A): N-phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine, "6PPD" (manufactured by Monsanto)
j) Anti-aging agent (B): 2,2,4-trimethyl-1,2-dihydroquinoline polymer, "RD", (made by Ouchi New Chemical Co., Ltd.)
k) Sulfur: "5% oil-filled fine powder sulfur" (made by Tsurumi Chemical Industry Co., Ltd.)
l) Vulcanization accelerator (A): N-cyclohexyl-2-benzothiazole sulfenamide, "Sunseller CM", (manufactured by Sanshin Chemical Industry Co., Ltd.)
m) Vulcanization accelerator (B): 1,3-diphenylguanidine, "Noxceler D", (made by Ouchi New Chemical Co., Ltd.)
<実施例1>
<ゴムラテックス溶液の調整>
 天然ゴムラテックス濃縮ラテックス溶液に、以下の機械安定性が600秒となるように、常温下でアンモニアを加えた。次いで常温で水を加えて、ゴム成分が25重量%のゴムラテックス溶液を調製した。
[ゴムラテックス溶液の機械安定性の測定]
 ゴムラテックス溶液の機械安定性の測定は、ASTM D1076-59に準じ、14000rpmにて回転板を回転させてラテックス中に目視にて明らかな凝固物が発見されるまでの時間(秒)を計測した。なお、当該測定におけるゴムラテックス溶液中のゴム固形分の濃度は60重量%である。
Example 1
<Preparation of rubber latex solution>
Ammonia was added to the natural rubber latex-concentrated latex solution at room temperature so that the following mechanical stability was 600 seconds. Subsequently, water was added at normal temperature to prepare a rubber latex solution having a rubber component of 25% by weight.
[Measurement of mechanical stability of rubber latex solution]
The mechanical stability of the rubber latex solution was measured by rotating the rotating plate at 14000 rpm according to ASTM D 1076-59, and measuring the time (seconds) until visually apparent coagulated material was found in the latex. . In addition, the density | concentration of rubber | gum solid content in the rubber latex solution in the said measurement is 60 weight%.
<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>
 上記で得られた所定の機械安定性を有するゴムラテックス溶液に水を加え、濃度0.5重量%ゴム希薄ラテックス水溶液を調製した。得られたゴム希薄ラテックス水溶液に、カーボンブラック「N339」を50重量部(ラテックス溶液の固形分量(ゴム量)が、カーボンブラックとの重量比で1重量部)添加し、これにPRIMIX社製ロボミックスを使用してカーボンブラックを分散させることにより(該ロボミックスの条件:9000rpm、30分)、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造した(工程(I-a2))。次に、工程(I-a2)で製造したゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液に、残りの上記で得られた所定の機械安定性を有するゴムラテックス溶液(25重量%)を、工程(I-a2)で使用したゴム希薄ラテックス水溶液と合わせて、固形分(ゴム)量が100重量部となるように添加し、次いでSANYO社製家庭用ミキサーSM-L56型を使用して混合し(ミキサー条件11300rpm、30分)、ゴムラテックス粒子が付着したカーボンブラック含有ゴムラテックス溶液を製造した(工程(I-b2))。
<Step (I): Production of Carbon Black-Containing Rubber Latex Solution>
Water was added to the rubber latex solution having the predetermined mechanical stability obtained above to prepare a 0.5 wt% rubber dilute latex aqueous solution. To the obtained rubber dilute latex aqueous solution, 50 parts by weight of carbon black "N339" (the solid content (rubber amount) of the latex solution is 1 part by weight relative to carbon black) is added, and to this ROMIBO manufactured by PRIMIX The carbon black-containing slurry solution to which rubber latex particles were attached was produced by dispersing carbon black using the mix (conditions of the robot mix: 9000 rpm, 30 minutes) (step (I-a2)). Next, the remaining carbon latex-containing slurry solution to which the rubber latex particles produced in the step (I-a2) have been adhered is treated with the remaining rubber latex solution (25% by weight) having the predetermined mechanical stability obtained above. Add together with the rubber dilute latex aqueous solution used in (I-a2) so that the solid content (rubber) amount is 100 parts by weight, and then mix using a SANYO household mixer SM-L56. (Mixer conditions 11300 rpm, 30 minutes) A carbon black-containing rubber latex solution to which rubber latex particles were attached was produced (step (I-b2)).
<工程(II):カーボンブラック含有ゴム凝固物の製造>
 上記の工程(I)で製造したカーボンブラック含有ゴムラテックス溶液に、ギ酸(10%)を溶液全体がpH7.2となるまで添加し、SANYO社製家庭用ミキサーSM-L56型を使用してさらに混合を行った(ミキサー条件:11300rpm、25分)。次いで、凝固剤として、ギ酸(10%溶液)を溶液全体がpH4となるまで添加し、さらにSANYO社製家庭用ミキサーSM-L56型を使用することで(ミキサー条件:11300rpm、2分)、カーボンブラック含有ゴム凝固物を製造した(工程(II))。なお、pHは、JIS Z8802準拠し、東亜ディーケーケー(株)製、「ポータブルpH計HM-30P」を用いて、評価した。
<Step (II): Production of carbon black-containing rubber coagulated material>
Formic acid (10%) is added to the carbon black-containing rubber latex solution produced in the above step (I) until the whole solution reaches a pH of 7.2, and it is further added using SANYO's household mixer SM-L56. Mixing was performed (mixer conditions: 11300 rpm, 25 minutes). Then, formic acid (10% solution) is added as a coagulant until the whole solution reaches pH 4, and furthermore, by using SANYO's household mixer SM-L56 type (mixer conditions: 11300 rpm, 2 minutes), carbon A black-containing rubber coagulum was produced (step (II)). The pH was evaluated according to JIS Z8802 using "Portable pH meter HM-30P" manufactured by Toa DKK Co., Ltd.
<工程(III):ゴムウエットマスターバッチの製造>
 上記の工程(II)で製造したカーボンブラック含有ゴム凝固物を、スクイザー式1軸押出脱水機(スエヒロEPM社製V-02型)で水分率が1.5%以下になるまで脱水および乾燥することにより、ゴムウエットマスターバッチを製造した(工程(III))。
<Step (III): Production of Rubber Wet Masterbatch>
The carbon black-containing rubber coagulated material produced in the above step (II) is dewatered and dried with a squeezer type single-screw extrusion dehydrator (V-02 type made by Suehiro EPM) until the water content becomes 1.5% or less Thus, a rubber wet masterbatch was produced (step (III)).
<工程(IV):ゴム組成物および未加硫ゴム組成物の製造>
 上記で得られたゴムウエットマスターバッチと、表3に記載の各原料(硫黄と加硫促進剤を除く成分)を、バンバリーミキサーを用いて乾式混合(混練時間:3分、排出温度:150℃)することにより、ゴム組成物を製造した。次いで、得られたゴム組成物に、表3に記載の硫黄、加硫促進剤(A)および加硫促進剤(B)を加え、バンバリーミキサーを用いて乾式混合(混練時間:1分、排出温度:90℃)することにより、未加硫ゴム組成物を製造した。なお、表3中の配合比率は、ゴム組成物に含まれるゴム成分の全量を100重量部としたときの重量部(phr)で示す。
<Step (IV): Production of Rubber Composition and Unvulcanized Rubber Composition>
Dry mixing (mixing time: 3 minutes, discharge temperature: 150 ° C.) of the rubber wet masterbatch obtained above and each raw material listed in Table 3 (components other than sulfur and vulcanization accelerator) using a Banbury mixer The rubber composition was manufactured by carrying out. Next, the sulfur, vulcanization accelerator (A) and vulcanization accelerator (B) listed in Table 3 are added to the obtained rubber composition, and dry mixing (kneading time: 1 minute, discharge using a Banbury mixer) The unvulcanized rubber composition was manufactured by carrying out temperature: 90 degreeC. In addition, the compounding ratio in Table 3 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber composition is 100 weight part.
<実施例2~10および比較例1~5>
 実施例1の<ゴムラテックス溶液の調製>において、ゴムラテックスの機械安定性を表3に示す値に変更したこと、また、実施例1の<工程(I):カーボンブラック含有ゴムラテックス溶液の製造>において、使用するカーボンブラックを表3に示す種類および配合量に変更したこと、また、実施例1の<工程(II):カーボンブラック含有ゴム凝固物の製造>において、凝固前のカーボンブラック含有ゴムラテックス溶液のpHを表3に示す値に変更したこと以外は、実施例1と同様の方法により、実施例2~10および比較例1~5のゴム組成物および未加硫ゴム組成物を製造した。なお、表3中の配合量は、ゴムウエットマスターバッチに含まれるゴム成分の全量を100重量部としたときの重量部(phr)で示す。
Examples 2 to 10 and Comparative Examples 1 to 5
In <Preparation of rubber latex solution> of Example 1, the mechanical stability of the rubber latex was changed to a value shown in Table 3. Further, <Step (I) of Example 1: Production of carbon black-containing rubber latex solution In <>, the carbon black to be used was changed to the kind and compounding amount shown in Table 3, and in <Step (II) of Example 1: Production of carbon black-containing rubber coagulated material>, carbon black-containing before solidification. The rubber compositions and unvulcanized rubber compositions of Examples 2 to 10 and Comparative Examples 1 to 5 were prepared in the same manner as in Example 1 except that the pH of the rubber latex solution was changed to the values shown in Table 3. Manufactured. In addition, the compounding quantity in Table 3 shows a weight part (phr) when the whole quantity of the rubber component contained in a rubber wet masterbatch is 100 weight part.
 上記の実施例及び比較例で得られた未加硫ゴム組成物を、150℃、30分間の条件で加硫することにより、加硫ゴムを製造した。得られた加硫ゴムについて以下の評価を行った。評価結果を表3に示す。 A vulcanized rubber was produced by vulcanizing the unvulcanized rubber compositions obtained in the above Examples and Comparative Examples under the conditions of 150 ° C. and 30 minutes. The following evaluation was performed about the obtained vulcanized rubber. The evaluation results are shown in Table 3.
<発熱性の評価>
 発熱性の評価は、JIS K6265に準じて、UBM社製レオスペクトロメーターE4000を用い、静歪み10%、動的歪±2%、周波数50Hz、温度80℃の条件下で、損失係数tanδを測定し、実施例1~6、9および10、ならびに比較例2~3は比較例1の値を100とした指数、実施例7は比較例4の値を100とした指数、実施例8は比較例5の値を100とした指数で表示した。指数が小さいほど、発熱し難く、低発熱性に優れることを示す。
<Evaluation of heat buildup>
For evaluation of heat buildup, the loss coefficient tan δ is measured under the conditions of static strain 10%, dynamic strain ± 2%, frequency 50 Hz and temperature 80 ° C. using a rheometer E4000 manufactured by UBM in accordance with JIS K6265. Examples 1 to 6, 9 and 10, and Comparative Examples 2 to 3 are indices based on the value of Comparative Example 1 being 100, Example 7 is the index based on the value for Comparative Example 4 being 100, Example 8 is a comparison The values in Example 5 were expressed as an index of 100. The smaller the index is, the less the heat is generated and the lower the heat buildup is.
<耐疲労性の評価>
 耐疲労性の評価は、JIS K6260に準じて、デマチャ屈曲試験機を用い、亀裂が発生するまでの回数を測定し、実施例1~6、9および10、ならびに比較例2~3は比較例1の値を100とした指数、実施例7は比較例4の値を100とした指数、実施例8は比較例5の値を100とした指数で表示した。指数が大きいほど、耐疲労性に優れることを意味する。
<Evaluation of fatigue resistance>
The evaluation of the fatigue resistance was carried out according to JIS K6260, using a demacia bending tester to measure the number of times until the occurrence of a crack, and Examples 1-6, 9 and 10, and Comparative Examples 2-3 are comparative examples. In the example, the value of Comparative Example 4 is 100. The value of Comparative Example 5 is 100. The value of Comparative Example 4 is 100. The larger the index, the better the fatigue resistance.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003

Claims (9)

  1.  少なくともカーボンブラック、分散溶媒、およびゴムラテックス溶液を原料として得られるゴムウエットマスターバッチの製造方法であって、
     前記カーボンブラック、前記分散溶媒、および前記ゴムラテックス溶液を混合して、カーボンブラック含有ゴムラテックス溶液を製造する工程(I)と、
     得られたカーボンブラック含有ゴムラテックス溶液を凝固して、カーボンブラック含有ゴム凝固物を製造する工程(II)を含み、
     前記工程(I)において、ASTM D1076-59に準じて測定した、前記ゴムラテックス溶液の機械的安定性が、300秒以上であり、
     前記工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~8.5であることを特徴とするゴムウエットマスターバッチの製造方法。
    A method for producing a rubber wet masterbatch obtained using at least carbon black, a dispersion solvent, and a rubber latex solution as a raw material,
    A step (I) of mixing the carbon black, the dispersion solvent, and the rubber latex solution to produce a carbon black-containing rubber latex solution;
    Including the step (II) of coagulating the obtained carbon black-containing rubber latex solution to produce a carbon black-containing rubber coagulated product,
    In the step (I), the mechanical stability of the rubber latex solution measured according to ASTM D 1076-59 is 300 seconds or more.
    In the step (II), the pH of the carbon black-containing latex solution before coagulation is 6.0 to 8.5, and the method for producing a rubber wet masterbatch.
  2.  前記工程(II)において、凝固前の前記カーボンブラック含有ラテックス溶液のpHが、6.0~7.4であることを特徴とする請求項1記載のゴムウエットマスターバッチの製造方法。 The method for producing a rubber wet masterbatch according to claim 1, wherein in the step (II), the pH of the carbon black-containing latex solution before coagulation is 6.0 to 7.4.
  3.  前記工程(I)が、前記カーボンブラックを前記分散溶媒中に分散させて、カーボンブラック含有スラリー溶液を製造する工程(I-a1)と、
     得られたカーボンブラック含有スラリー溶液と、前記ゴムラテックス溶液とを混合して、カーボンブラック含有ゴムラテックス溶液を製造する工程(I-b1)を含むことを特徴とする請求項1または2記載のゴムウエットマスターバッチの製造方法。
    A step (I-a1) of producing a carbon black-containing slurry solution by dispersing the carbon black in the dispersion solvent in the step (I);
    The rubber according to claim 1 or 2, comprising the step (I-b1) of producing a carbon black-containing rubber latex solution by mixing the obtained carbon black-containing slurry solution with the rubber latex solution. Method of producing wet masterbatch.
  4.  前記工程(I)が、前記カーボンブラックを前記分散溶媒中に分散させる際に、前記ゴムラテックス溶液の少なくとも一部を添加することにより、ゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液を製造する工程(I-a2)と、
     得られたゴムラテックス粒子が付着したカーボンブラック含有スラリー溶液と、残りの前記ゴムラテックス溶液とを混合して、ゴムラテックス粒子が付着したカーボンブラック含有ゴムラテックス溶液を製造する工程(I-b2)を含むことを特徴とする請求項1または2記載のゴムウエットマスターバッチの製造方法。
    A step of producing a carbon black-containing slurry solution to which rubber latex particles adhere by adding at least a part of the rubber latex solution when the carbon black is dispersed in the dispersion solvent in the step (I) (I-a2),
    A step (I-b2) of producing a carbon black-containing rubber latex solution with rubber latex particles adhered by mixing the obtained carbon black-containing slurry solution with the rubber latex particles attached and the remaining rubber latex solution A method for producing a rubber wet masterbatch according to claim 1 or 2, characterized in that it comprises.
  5.  さらに、得られたカーボンブラック含有ゴム凝固物を脱水・乾燥する工程(III)を含むことを特徴とする請求項1~4のいずれかに記載のゴムウエットマスターバッチの製造方法。 The method for producing a rubber wet masterbatch according to any one of claims 1 to 4, further comprising a step (III) of dewatering and drying the obtained carbon black-containing rubber coagulated material.
  6.  さらに、前記1~5のいずれかに記載のゴムウエットマスターバッチの製造方法で得られたゴムウエットマスターバッチを用いて、乾式混合する工程(IV)を含むことを特徴とするタイヤ用ゴム組成物の製造方法。 Furthermore, a rubber composition for a tire comprising a step (IV) of dry mixing using the rubber wet masterbatch obtained by the method for producing a rubber wet masterbatch according to any one of 1 to 5 above. Manufacturing method.
  7.  前記工程(IV)において、前記ゴムウエットマスターバッチとゴムを用いて、乾式混合する工程を含み、
     前記ゴムラテックス溶液が、天然ゴムラテックス溶液であり、
     前記ゴムが、合成ジエン系ゴムであることを特徴とする請求項6記載のタイヤ用ゴム組成物の製造方法。
    In the step (IV), the step of dry mixing using the rubber wet masterbatch and the rubber is included,
    The rubber latex solution is a natural rubber latex solution,
    The method for producing a rubber composition for a tire according to claim 6, wherein the rubber is a synthetic diene rubber.
  8.  タイヤトレッド用であることを特徴とする請求項6または7記載のタイヤ用ゴム組成物の製造方法。 The method for producing a rubber composition for a tire according to claim 6 or 7, which is for a tire tread.
  9.  プライトッピング用であることを特徴とする請求項6または7記載のタイヤ用ゴム組成物の製造方法。 The method for producing a rubber composition for a tire according to claim 6 or 7, which is for pre-papping.
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JP2012184354A (en) * 2011-03-07 2012-09-27 Toyo Tire & Rubber Co Ltd Unvulcanized rubber composition, manufacturing method thereof, and pneumatic tire
JP2015048416A (en) * 2013-09-02 2015-03-16 東洋ゴム工業株式会社 Rubber wet master batch, manufacturing method thereof, rubber composition, and pneumatic tire
JP2017039881A (en) * 2015-08-21 2017-02-23 東洋ゴム工業株式会社 Manufacturing method for rubber wet master batch, manufacturing method of rubber composition and manufacturing method of tire

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JP2015048416A (en) * 2013-09-02 2015-03-16 東洋ゴム工業株式会社 Rubber wet master batch, manufacturing method thereof, rubber composition, and pneumatic tire
JP2017039881A (en) * 2015-08-21 2017-02-23 東洋ゴム工業株式会社 Manufacturing method for rubber wet master batch, manufacturing method of rubber composition and manufacturing method of tire

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