JP2016175980A - Manufacturing method of rubber wet master batch, rubber composition and member for tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance vulcanized rubber properties of a rubber composition obtained from the rubber wet master batch by inhibiting cutting a molecular chain of a rubber polymer by heat generated by a shear force while enhancing dispersion degree of a filler with adding shear force to a filler-containing rubber coagulum.SOLUTION: There is used a manufacturing method of a rubber master batch obtained by using a filler, a dispersion solvent and a rubber latex solution as raw materials and having a solidification process, a dehydration process of adding shear force till moisture content of the coagulum becomes 10% or less and dehydrating to manufacture the rubber master batch, a cooling process of cooling the rubber wet master batch and a drying process of drying the cooled rubber wet master batch.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a rubber wet masterbatch, a rubber composition, and a tire member.
Further, the present invention particularly relates to a method for producing a rubber wet masterbatch obtained using a filler, a dispersion solvent containing water, and a rubber latex solution as raw materials, and a rubber composition and a tire using the obtained masterbatch. It relates to members.

In the production of a tire rubber composition, it is known that the properties of the tire rubber composition can be improved by improving the degree of dispersion of the filler in the rubber composition.
In addition, as a method of highly dispersing the filler in the tire rubber composition, a rubber wet masterbatch is first manufactured from the rubber polymer and the filler, and a tire rubber composition is manufactured using the manufactured rubber wet masterbatch as a raw material. How to do is known.
The rubber wet masterbatch is produced by mixing a slurry solution in which a filler such as carbon black is dispersed in a dispersion solvent and a latex solution containing a rubber polymer, and removing the dispersion solvent from the mixed solution.

In the production of a rubber wet masterbatch, when a rubber polymer and a filler are dispersed in a dispersion solvent to form a slurry solution, the filler is highly dispersed in the rubber polymer. Also, the filler is highly dispersed in the rubber wet masterbatch produced after removing the dispersion solvent.
Therefore, when a tire rubber composition is produced from a rubber wet masterbatch, a tire rubber composition having an excellent filler dispersibility compared to kneading a filler in a solid phase with a rubber polymer is produced. Can do. As a result, a tire excellent in characteristics such as rolling resistance, fatigue resistance, and wear resistance can be produced from a rubber composition for tires produced using a rubber wet masterbatch as a raw material.

Regarding a method for producing a rubber wet master batch, a slurry solution containing a filler and a dispersion solvent and a rubber latex solution are mixed and coagulated to produce a filler-containing rubber coagulum, and a first uniaxial extrusion. Dehydration process in which a rubber wet masterbatch is produced by heating and dehydrating the filler-containing rubber coagulum using a machine, and plasticizing while heating the rubber wet masterbatch using a second single screw extruder Thus, there is known a method for producing a rubber wet masterbatch having at least a dry plasticization step for producing a rubber wet masterbatch having a further reduced water content (Patent Document 1).
However, in the method for producing a rubber wet masterbatch described in the same document, the masterbatch after dehydration by the extruder becomes a high temperature due to heat generated by applying mechanical energy. For this reason, the molecular chain of the rubber polymer is broken, and there is a problem that the vulcanized rubber characteristics of the finally obtained rubber composition are deteriorated.

JP 2013-147574 A

  The present invention intends to solve the above-described problems of the prior art. That is, the present invention further increases the dispersibility of the filler by applying a shearing force to the filler-containing rubber coagulated product, while preventing heat generated by the shearing force from breaking the molecular chain of the rubber polymer. It aims at improving the vulcanized rubber characteristic of manufacture of a wet masterbatch, and the rubber composition obtained from it.

  As a result of earnest research, the inventors of the present invention are a method for producing a rubber wet masterbatch obtained using a filler, a dispersion solvent containing water, and a rubber latex solution as raw materials, and the filler is dispersed in the dispersion solvent. A coagulation step for producing a filler-containing rubber coagulum by coagulating a mixed solution obtained by mixing the slurry solution and the rubber latex solution, and the water content of the filler-containing rubber coagulum is 10% by mass or less. A dehydration step of producing a rubber wet masterbatch by dehydrating by applying a shearing force until it becomes, a cooling step of cooling the rubber wet masterbatch with a refrigerant, and drying the rubber wet masterbatch cooled in the cooling step It has been found that the above problem can be solved by using a method for producing a rubber wet masterbatch having a drying step.

That is, the present invention relates to the following (1) to (7).
(1) A method for producing a rubber wet masterbatch obtained using a filler, a dispersion solvent containing water, and a rubber latex solution as raw materials,
A coagulation step for producing a filler-containing rubber coagulum by coagulating a mixed solution obtained by mixing a slurry solution in which a filler is dispersed in a dispersion solvent and a rubber latex solution;
A dehydration step of producing a rubber wet masterbatch by dehydrating the filler-containing rubber coagulum by applying a shearing force until the water content is 10% by mass or less;
A cooling step of cooling the rubber wet masterbatch with a refrigerant;
as well as,
The manufacturing method of the rubber wet masterbatch which has a drying process which dries the rubber wet masterbatch cooled in the said cooling process.
(2) The manufacturing method of the rubber wet masterbatch as described in said (1) whose filler contains carbon black.
(3) The manufacturing method of the rubber wet masterbatch as described in said (1) or (2) with which a filler contains a silica.
(4) The manufacturing method of the rubber wet masterbatch as described in any one of said (1)-(3) whose refrigerant is water.
(5) The manufacturing method of the rubber wet masterbatch as described in any one of said (1)-(4) whose temperature of a drying process is 70 degrees C or less and whose humidity is 90% or less.
(6) A rubber composition using a rubber wet masterbatch obtained by the production method according to any one of (1) to (5) as a raw material.
(7) A tire member produced using the rubber composition according to (6).

According to the present invention, while further increasing the dispersity of the filler in the rubber wet masterbatch by the shearing force, the heat generated by the shearing force is efficiently removed, and the molecular chain of the rubber polymer by the heat generated in the masterbatch A rubber wet masterbatch can be obtained in which the cutting is prevented.
By removing the heat generated by the shearing force from the rubber wet masterbatch after the dehydration step in the cooling step of the present invention, a shearing force larger than that of the conventional manufacturing method can be applied. As a result, in the present invention, the degree of dispersion of the filler in the rubber wet masterbatch can be increased as compared with the conventional production method.
By using the rubber wet masterbatch produced by the method for producing a rubber wet masterbatch of the present invention as a raw material, a tire member having excellent heat generation and wear resistance can be produced.
Further, in the drying process of the present invention, the rubber wet masterbatch can be stored in a stable state for a long period of time without causing an increase in moisture content by drying at a temperature and humidity defined by the present invention. .

Hereinafter, embodiments of the present invention will be described in detail.
<Rubber wet master batch manufacturing method>
The rubber wet master batch production method of the present invention produces a filler-containing rubber coagulum by coagulating a mixed solution obtained by mixing a slurry solution in which a filler is dispersed in a dispersion solvent and a rubber latex solution. A solidification step, a dehydration step of producing a rubber wet masterbatch by dehydrating the filler-containing rubber coagulated product obtained in the coagulation step by applying a shearing force until the water content is 10% by mass or less, and the dehydration step. A cooling step of cooling the obtained rubber wet masterbatch with a refrigerant, and a drying step of drying the rubber wet masterbatch cooled in the cooling step.

<Coagulation process>
In the coagulation step in the method for producing a rubber wet masterbatch of the present invention, a slurry solution in which a filler is dispersed in a dispersion solvent and the rubber latex solution are mixed in a liquid phase, and the mixed solution is coagulated to contain a filler. A rubber coagulum is produced.

〔filler〕
In the method for producing a rubber wet masterbatch of the present invention, a slurry solution in which a filler is dispersed in a dispersion solvent is prepared.
The filler used for preparing the slurry solution is not particularly limited as long as the effect is not lost by the action of the dispersion solvent. As the filler, reinforcing fillers such as carbon black and silica are preferably used.
Further, it is desirable that the filler is appropriately selected in consideration of the fact that the microstructure can be changed by the shearing force applied in the dehydration step in the present invention.

  As a step prior to manufacturing a filler-containing rubber coagulum, a slurry solution in which a filler such as carbon black and silica is dispersed in a dispersion solvent is prepared, and this is mixed with a rubber latex solution to prepare a mixed solution. To do.

Preparation of slurry solution (dispersion solvent)
The dispersion solvent in the present invention is preferably water from the viewpoint of ease of handling. In the dispersion solvent, for the purpose of stably dispersing carbon black, silica, etc. in the slurry solution as required, surfactants and resins such as polyacrylates and styrene-acrylic acid copolymer salts are used. Vinyl naphthalene-acrylic acid copolymer salt, styrene-maleic acid copolymer salt, vinyl naphthalene-maleic acid copolymer salt, β-naphthalene sulfonic acid formalin condensate sodium salt, polyphosphate, etc. Anionic polymers, nonionic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyethylene glycol, proteins such as gelatin, albumin and casein, water-soluble natural rubbers such as gum arabic and tragacanth, and saponins Glucosides, methylcellulose, carboxymethylcellulose, hydroxymethy And cellulose derivatives such as cellulose, lignin sulfonate, a natural polymer may be added, such as shellac.
When the surface of the filler is acidic or acidified, a basic aqueous solution can be used in order to increase the dispersibility of the filler in the slurry solution. Preferred examples of the base used in the basic aqueous solution include sodium hydroxide and ammonia.

  In the present invention, a rotor / stator type high shear mixer, high pressure homogenizer, ultrasonic homogenizer, colloid mill, or the like is used for the production of an aqueous dispersion slurry solution of a filler such as carbon black and silica. For example, the slurry solution can be prepared by putting a predetermined amount of filler and water in a colloid mill and stirring at high speed for a certain time.

〔Carbon black〕
As carbon black used in the step of producing the slurry solution in the present invention, color carbon black can be used. Furthermore, as the carbon black, various grades of carbon black such as SAF, HAF, ISAF, FEF, and GPF can be used alone or in combination.

The carbon black in the present invention may have an acidic functional group introduced on the surface as necessary.
The method for introducing the acidic functional group is not particularly limited, and examples thereof include liquid phase oxidation treatment and gas phase oxidation treatment. This is because the gas phase ozone treatment is less expensive than the liquid phase oxidation treatment and can efficiently introduce carboxyl groups. Vapor phase ozone treatment refers to oxidation by bringing ozone gas into contact with dry carbon black. The gas phase ozone-treated carbon black is, for example, SBX45 manufactured by Asahi Carbon Co., Ltd.

  The oxidation treatment of carbon black in the present invention is preferably performed by a treatment in which dried carbon black is exposed to an ozone atmosphere of 0.1% by volume to 16% by volume. The treatment temperature in the oxidation treatment of carbon black under an ozone atmosphere is from room temperature to 100 ° C., and the treatment time is from 10 seconds to 300 seconds. Since this carbon black oxidation treatment is a method in which dry carbon black is directly oxidized with ozone gas, post-treatment (washing and drying) is not essential, and it is efficient, simple, and cost-effective.

〔silica〕
Silica may be added to the rubber wet masterbatch of the present invention. There is no restriction | limiting in particular as a manufacturing method of the silica used for this invention, A conventionally well-known thing can be used widely. Examples thereof include anhydrous silicic acid by a dry method, hydrous silicic acid by a wet method, and synthetic silicate. Examples thereof include silica modified with a silane coupling agent.

〔Silane coupling agent〕
When silica is blended in the method for producing a rubber wet masterbatch of the present invention, it can be used from the viewpoint of enhancing the dispersion of silica in the rubber wet masterbatch with a silane coupling agent.
By passing through the silane coupling agent, the effect of enhancing the interaction between silica and the rubber polymer and improving the degree of dispersion of silica can be expected.

Preparation of Mixed Solution In the method for producing a rubber wet masterbatch of the present invention, after the slurry solution is prepared, a mixed solution of the slurry solution and a rubber latex solution containing a rubber component is prepared.

Examples of the rubber latex solution used in the preparation of the mixed solution include natural rubber latex and / or synthetic rubber latex, or an organic solvent solution of synthetic rubber by solution polymerization. Among these, natural rubber latex and / or synthetic rubber latex are preferable from the viewpoint of the performance and ease of production of the obtained rubber wet masterbatch.
As the natural rubber latex, any of field latex, ammonia-treated latex, centrifugal concentrated latex, deproteinized latex treated with an enzyme, and a combination of the above-mentioned ones can be used.
As the synthetic rubber latex, for example, latex such as styrene-butadiene polymer rubber, synthetic polyisopyrene rubber, polybutadiene rubber, nitrile rubber, and polychloroprene rubber can be used.
The rubber polymer of the rubber latex may be a modified polymer, or may be used by blending a modified polymer with an unmodified polymer.
The rubber polymer of rubber latex may be used alone or in a blend of two or more.
The rubber polymer of the rubber latex may be terminal-modified for the purpose of improving the degree of dispersion of fillers such as silica and carbon black.

  As a mixing method of the slurry solution and the rubber latex solution, for example, the slurry solution is put in a homomixer and the rubber latex solution is dropped while stirring, or conversely, the rubber latex solution is stirred and the slurry is added thereto. There is a method of dropping the solution. It is also possible to use a method in which a slurry stream having a constant flow rate and a latex stream are mixed under vigorous hydraulic stirring conditions. Furthermore, a method of mixing the slurry flow and the latex flow using a static mixer, a high shear mixer, or the like can also be used.

  In the present invention, the rubber wet masterbatch after the above-mentioned mixing is coagulated using an acid such as formic acid or sulfuric acid or a salt coagulant such as sodium chloride as usual. In some cases, coagulation may be performed by adding a slurry solution and a rubber latex solution without adding a coagulant.

<Dehydration process>
In the dehydration step of the present invention, the rubber-containing master batch is produced by dehydrating the filler-containing rubber coagulated product obtained in the coagulation step by applying a shearing force until the water content becomes 10% by mass or less.
By performing dehydration while applying a shearing force, the dispersibility of fillers such as carbon black and silica in the rubber wet masterbatch can be improved.
The dehydration is performed while applying a shearing force until the water content of the filler-containing rubber coagulum becomes 10% by mass or less. The dehydration is more preferably performed while applying a shearing force to the filler-containing rubber coagulum until the water content becomes 5% or less, and more preferably 3% or less.
By dehydration performed while applying a shearing force, a rubber composition excellent in processability, reinforcement, and rubber properties can be produced using the obtained rubber wet master batch as a raw material. Dehydration in the method for producing the rubber wet masterbatch of the present invention can be performed using a general kneader.
The dehydration in the method for producing the rubber wet masterbatch of the present invention is preferably performed using a continuous kneader from the viewpoint of industrial productivity. Furthermore, it is more preferable to use a multi-screw kneading extruder that rotates in the same direction or in different directions, and it is particularly preferable to use a twin-screw kneading extruder.
In the dehydration step, a vacuum dryer may be used in combination so as not to apply excessive heat to the rubber wet masterbatch without departing from the object of the present invention of applying shear force to the filler-containing rubber coagulum.

<Cooling process>
Due to the shearing force applied in the dehydration step, the rubber wet masterbatch obtained in the dehydration step is usually at a high temperature.
In the cooling step in the present invention, the rubber wet masterbatch that has been obtained in the dehydration step is cooled.
In the cooling step of the present invention, the rubber wet masterbatch is cooled with a refrigerant.
The refrigerant is not particularly limited as long as it can cool the rubber wet masterbatch at a high temperature with a suitable temperature change. However, the method of cooling with a refrigerant does not include the method of leaving the rubber wet masterbatch and allowing it to cool.
The refrigerant is not limited to a liquid but may be a gas, or a gas may be blown at an appropriate temperature and flow rate. The refrigerant may be a solid, or the solid may be contacted at an appropriate temperature for a certain time. The refrigerant is preferably water from the viewpoint of ease of handling.
The method of cooling with a refrigerant is preferably a method of immersing a rubber wet masterbatch in a refrigerant bath. From the viewpoint of stabilization of quality, it is preferable that the refrigerant in the bath is maintained at a temperature within a certain range. Moreover, it is preferable that the time which immerses a rubber wet masterbatch in a refrigerant | coolant bath is the time of a fixed range.
The temperature and time are appropriately selected according to the components of the rubber wet masterbatch to be cooled, the size and shape of the lump of the rubber wet masterbatch, and the like.

<Drying process>
In the drying step of the present invention, the rubber wet masterbatch cooled with the refrigerant is dried at a constant temperature and humidity.
The temperature for drying the rubber wet masterbatch is 45 ° C to 70 ° C, preferably 55 ° C to 65 ° C.
The humidity for drying the rubber wet masterbatch is 40% to 90%, preferably 50% to 70%.
The combination of the temperature and humidity for drying the rubber wet masterbatch is preferably a temperature of 55 ° C. to 65 ° C. and a humidity of 50% to 70%.
The rubber wet masterbatch that has been dried at a constant temperature and humidity in the drying step does not cause an increase in moisture content and can be stored in a stable state for a long period of time.

(Rubber composition)
Production of Rubber Composition A rubber composition produced using the rubber wet masterbatch of the present invention as a raw material is obtained by blending a rubber wet masterbatch using carbon black obtained by the above-described method of the present invention.
In the production of the rubber composition, a rubber wet masterbatch that has been stored under the conditions of the drying step in the present invention is directly used.
The rubber composition of the present invention includes reinforcing fillers and compounding agents commonly used in the rubber industry, such as vulcanizing agents, vulcanization accelerators, anti-aging agents, softening agents, stearic acid, and process oils. , Zinc white, scorch inhibitor and the like can be appropriately selected and blended within a range not impairing the object of the present invention. As these compounding agents, commercially available products can be suitably used.
Moreover, in this rubber composition, it is preferable that the rubber component in the rubber wet masterbatch is 30% by mass or more with respect to the entire rubber component. Examples of other rubber components used in addition to the rubber wet masterbatch include ordinary natural rubber and diene synthetic rubber. Examples of the diene synthetic rubber include styrene-butadiene copolymer (SBR), Examples include polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, and mixtures thereof.
Examples of the vulcanizing agent include sulfur, and the amount used is preferably 0.1 parts by mass or more and 10.0 parts by mass or less as a sulfur content with respect to 100 parts by mass of the rubber component. It is more preferable that the amount is not less than 5.0 parts by mass.

The vulcanization accelerator that can be used in the present invention is not particularly limited, and examples thereof include M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), and CZ (N-cyclohexyl-2-benzothiazyl). Sulfenamide), NS (Nt-butyl-2-benzothiazylsulfenamide) and other thiazole-based guanidine-based vulcanization accelerators such as DPG (diphenylguanidine), and the like. The amount used is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.2 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the rubber component.
The anti-aging agent that can be used in the present invention is not particularly limited, and examples thereof include amine-based, phenol-based, organic phosphite-based, and thioether-based anti-aging agents. The amount used is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the rubber component.

  The rubber composition of the present invention can be used not only for tire applications but also for applications such as anti-vibration rubber, belts, hoses and other industrial products. In particular, it is suitably used as tire rubber, and can be applied to all tire members such as tread rubber, side rubber, ply coating rubber, bead filler rubber, and belt coating rubber.

EXAMPLES The present invention will be described below with reference to examples, but the scope of the present invention is not limited by these examples.
In the present invention, various measurements were performed by the following methods.

(Dispersion evaluation method)
The degree of dispersion is obtained by indexing the reciprocal of the magnitude of the Payne effect obtained by viscoelasticity measurement using Comparative Example 1 as 100 using an unvulcanized viscoelastic device “RPA2000 (manufactured by ALPHA TECHNOLOGIES)”.
It shows that the dispersibility of carbon black in a rubber wet masterbatch is so high that a numerical value is large.

(Method for evaluating exothermicity)
The tire material exothermic property was calculated by the following formula (1) by obtaining tan δ using a spectrometer (dynamic strain amplitude 1%, frequency 52 Hz, measurement temperature 25 ° C.) manufactured by TOYOSEIKI Co., Ltd.
Exothermic index = (tan δ of test specimen) / (tan δ of test specimen of Comparative Example 1) (1)
The lower the numerical value, the better the exothermicity.

(Abrasion resistance evaluation method)
The tire material wear resistance was evaluated by the Lambourne test.
The Lambourn abrasion resistance index, which is an abrasion resistance test, is shown as an index with a slip ratio of 60% and Comparative Example 10 as 100. The higher the value, the better the wear resistance.

[Examples 1-6 and Comparative Examples 1-2]
A 50% aqueous basic aqueous solution was prepared so that sodium hydroxide was 0.1% by mass relative to the total amount of slurry. Oxidized carbon black was added and finely dispersed with a high shear mixer (“800LS” manufactured by Silverson) to prepare a slurry solution having a carbon black concentration of 10 mass%.
The slurry solution and the rubber latex solution were mixed and stirred to prepare a mixed solution. As the rubber latex, a natural rubber latex containing ammonia diluted to 25% by mass was used.
Thereafter, formic acid was added to the mixed solution, and the mixed solution was solidified by stirring to obtain a filler-containing rubber coagulated product. The filler-containing rubber coagulum was dehydrated by applying a shearing force to produce a rubber wet masterbatch.

表１中の＊１〜＊２は下記のとおりである。
＊１ ゴムラテックス中天然ゴム成分 ２５質量％に希釈したアンモニアを含む天然ゴムラテックスにおける、天然ゴム成分。
＊２ カーボンブラック カーボンブラック（旭カーボン株式会社製、「ＳＢＸ４５」）を酸化処理して、表面平均酸性官能基量を０．６（μｅｑ／ｍ²）としたもの。
酸性官能基量を定量する手段としては、例えば、Ｂｏｅｈｍらが提案する方法が挙げられる。
＜Ｂｏｅｈｍらの方法＞
カーボンブラック１０ｇと０．０１ｍｏｌ／ＬのＣ₂Ｈ₅ＯＮａ水溶液５０ｇをフラスコ中で２時間攪拌後、２２時間室温で静置する。静置後、さらに３０分間攪拌してから濾過し、濾液を回収する。回収した濾液２５ｍＬを０．０１ｍｏｌ／ＬのＨＣｌ水溶液で中和滴定し、ｐＨが４．０に到達するまでに要するＨＣｌ水溶液量（ｍＬ）を測定する。該ＨＣｌ水溶液量と下記式（２）から表面平均酸性官能基量（ミリ当量／ｋｇ）を算出する。
酸性官能基量＝（２５−ＨＣｌ水溶液量）×２・・・（２）
表面平均酸性官能基量は、上記方法にて測定した酸性官能基量を窒素吸着比表面積で除した値であり、単位面積当たりの当量（μｅｑ／ｍ²）で示される。 Table 1 shows the number of blended parts by weight in the mixed solution.

* 1 to * 2 in Table 1 are as follows.
* 1 Natural rubber component in rubber latex Natural rubber component in natural rubber latex containing ammonia diluted to 25% by mass.
* 2 Carbon black Carbon black ("SBX45" manufactured by Asahi Carbon Co., Ltd.) was oxidized to have a surface average acidic functional group amount of 0.6 (µeq / m ² ).
As a means for quantifying the amount of the acidic functional group, for example, a method proposed by Boehm et al.
<Method of Boehm et al.>
10 g of carbon black and 50 g of a 0.01 mol / L C ₂ H ₅ ONa aqueous solution are stirred in a flask for 2 hours and then allowed to stand at room temperature for 22 hours. After standing, the mixture is further stirred for 30 minutes and then filtered to collect the filtrate. 25 mL of the collected filtrate is neutralized and titrated with a 0.01 mol / L HCl aqueous solution, and the amount of HCl aqueous solution (mL) required until the pH reaches 4.0 is measured. The surface average acidic functional group amount (milli equivalent / kg) is calculated from the amount of the HCl aqueous solution and the following formula (2).
Acidic functional group amount = (25-HCl aqueous solution amount) × 2 (2)
The surface average acidic functional group amount is a value obtained by dividing the acidic functional group amount measured by the above method by the nitrogen adsorption specific surface area, and is represented by an equivalent per unit area (μeq / m ² ).

The rubber wet master batches of Examples 1 to 6 and Comparative Examples 1 to 2 were manufactured according to the respective water removal drying methods, cooling methods, and drying conditions shown in Table 2.
Using the rubber wet master batches obtained in the above Examples and Comparative Examples as raw materials, kneading other than vulcanized chemicals was performed by adding stearic acid, zinc white and anti-aging agent, and then sulfur and vulcanized An accelerator was added and vulcanized chemicals were kneaded to obtain a vulcanized rubber composition.
About the vulcanized rubber composition manufactured using the wet masterbatch of each Example and a comparative example as a raw material, the exothermic measurement and the abrasion resistance were measured with the said measuring method. The values are shown in Table 2.

＊３ 実施例５及び実施例６の発熱性及び耐摩耗性については、乾燥が不十分のため、未評価。
冷却方法において、水冷は、水を冷媒とするもの、空冷は、ゴムウェットマスターバッチを静置して放冷する方法によるもの、風冷は、風を吹き当てることによるものである。

* 3 The heat buildup and wear resistance of Examples 5 and 6 were not evaluated due to insufficient drying.
In the cooling method, water cooling uses water as a refrigerant, air cooling uses a method in which a rubber wet masterbatch is left standing to cool, and air cooling uses a wind blow.

上記表３中の＊４〜＊５は下記のとおりである。
＊４ 老化防止剤 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、大内新興化学工業株式会社製「ノクラック６Ｃ」）
＊５ 加硫促進剤 大内新興化学工業株式会社製「ノクセラーＣＺ−Ｇ」

* 4 to * 5 in Table 3 are as follows.
* 4 Anti-aging agent N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine, “NOCRACK 6C” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
* 5 Vulcanization accelerator "Noxeller CZ-G" manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

The water removal method is a water removal method in the dehydration step. Extrusion indicates that moisture has been removed by an extruder, and hot air indicates that moisture has been removed by applying hot air.
The cooling method is a cooling method in the cooling step. Water cooling means that the rubber wet masterbatch is cooled by immersing it in a water bath, air cooling means that the rubber wet masterbatch is cooled by applying air, and air cooling means that the rubber wet masterbatch is allowed to cool in a room temperature atmosphere. Indicates.
The molecular weight of each example after the temperature of the rubber wet masterbatch became constant at the temperature of the drying step and the weight average molecular weight of the rubber wet masterbatch of the comparative example was set to 100 in Comparative Example 1 and the other examples. For the comparative example, the ratio of each value to that of comparative example 1 is multiplied by 100 and indicated as an index.

The moisture content is 100 for Comparative Example 1 with respect to the moisture content measured for the rubber wet masterbatch of each Example and Comparative Example, and 100 for each other Example and Comparative Example. It is shown as an index as a value multiplied by.
Exothermic property and abrasion resistance are values measured and evaluated by the above methods for the rubber wet masterbatches of the examples and comparative examples.

  As is apparent from Table 2 above, the rubber compositions of Examples 1 to 4 that fall within the scope of the present invention are more exothermic and wear resistant than the rubber compositions of Comparative Examples 1 and 2 that fall outside the scope of the present invention. Sexual value is high.

  By the rubber wet masterbatch production method of the present invention, a rubber wet masterbatch that is a raw material for a rubber composition having low heat buildup and wear resistance can be obtained. The present invention relates to a rubber wet masterbatch used as a raw material for various rubber compositions for tires for passenger cars, small trucks, light passenger cars, light trucks and large vehicles (trucks, buses, construction vehicles, etc.). It is suitably used as a production method.

Claims (7)

A method of manufacturing a rubber wet masterbatch obtained using a filler, a dispersion solvent containing water, and a rubber latex solution as raw materials,
A coagulation step for producing a filler-containing rubber coagulum by coagulating a mixed solution obtained by mixing a slurry solution in which a filler is dispersed in a dispersion solvent and a rubber latex solution;
A dehydration step of producing a rubber wet masterbatch by dehydrating the filler-containing rubber coagulum by applying a shearing force until the water content is 10% or less;
A cooling step of cooling the rubber wet masterbatch with a refrigerant;
as well as,
The manufacturing method of the rubber wet masterbatch which has a drying process which dries the rubber wet masterbatch cooled in the said cooling process.   The manufacturing method of the rubber wet masterbatch of Claim 1 with which a filler contains carbon black.   The manufacturing method of the rubber wet masterbatch of Claim 1 or 2 with which a filler contains a silica.   The manufacturing method of the rubber wet masterbatch of any one of Claims 1-3 whose refrigerant | coolant is water.   The method for producing a rubber wet masterbatch according to any one of claims 1 to 4, wherein the temperature in the drying step is 70 ° C or lower and the humidity is 90% or lower.   The rubber composition which uses the rubber wet masterbatch obtained by the manufacturing method of any one of Claims 1-5 as a raw material.   A tire member manufactured using the rubber composition according to claim 6.