JP2003286369A - Rubber-silica composite powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber-silica composite powder showing excellent productivity, capable of shortening kneading time to obtain a rubber such as a silica- containing SBR or the like and capable of giving excellent tensile strength and abrasion resistance due to good dispersion of the silica in the rubber. <P>SOLUTION: The rubber-silica composite powder is a composite particle obtained by spraying a mixture of a rubber latex using an anionic emulsifier, silica and a cationic activator and drying it and preferably has an average particle diameter of 50 to 500 μm measured by a vibrating screen method. The obtained rubber-silica composite powder may be kneaded as it is to give a rubber composition or it is kneaded with an unfilled rubber to produce a rubber composition having a silica content adjusted at a predetermined content. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to a rubber-silica composite.
For powder, specifically, obtain rubber such as silica-containing SBR.
When mixing, the kneading time can be reduced and the dispersion of silica in rubber
Rubber with good tensile strength and abrasion resistance
It is intended to provide a silica composite powder. [0002] 2. Description of the Related Art Conventionally, silica is used for reinforcing filling of various rubbers.
Widely used as an agent. Distribution of the above silica to rubber
In general, Banbury mixer, open roll,
Using a mechanical kneading device such as a kneader, the silica powder is
The so-called dry method of kneading and filling inside is widely performed
I have. In recent years, silica has been reported to have low fuel consumption and high grip properties.
Passenger cars that replace carbon black to balance
As a filler for tires for automobiles. But
Silica is hydrophilic and has strong self-aggregation properties.
Compared to carbon black, which is hydrophobic
It is easy to pack well into hydrophobic rubber.
Absent. Therefore, kneading in multiple stages is necessary, and productivity
Not only decreases, but the dispersibility of the silica is poor, resulting in
Properties such as tensile strength and abrasion resistance of rubber composition are sufficiently improved
It has the disadvantage that it is not performed. In order to solve the above-mentioned problems, Japanese Patent Laid-Open No.
No. 1090 discloses mixing water glass and rubber latex.
And then coagulate the rubber using an acid, and filter the coagulated product.
Filling with silica by washing, drying and drying
A method for obtaining the composition is disclosed. However, the particle size of the coagulated product is small.
Therefore, it takes time for filtration, and the silica moisture content is large.
The drying time must be extended, and the productivity is low.
There is a problem. Furthermore, the form after drying is a lump
Therefore, a pulverizing step is also required. [0006] Japanese Patent Application Laid-Open No. 2001-213971 discloses
Report, Japanese Patent Application Laid-Open No. 2001-253975,
Mix the aqueous suspension of xus and silica and use acid or salt
By coagulating the rubber, filtering and drying the coagulated product.
A method for obtaining a silica composition filled with silica has been proposed.
ing. However, in the above-mentioned rubber composition manufacturing process,
However, the filtration and drying steps take a long time,
There is a problem that is low. On the other hand, US Pat.
Mixing latex and silica and spray drying
A method for efficiently obtaining a rubber-silica composite powder is disclosed.
ing. However, the rubber obtained by this method-
Rubber composition obtained using silica composite powder
Rubber material with insufficient dispersibility, such as tensile strength and wear resistance
There was room for improvement in sex. [0008] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is as follows.
Is suitable for obtaining rubber such as silica-containing SBR which has excellent productivity.
The kneading time can be shortened, and the silica
Rubber set with good dispersion and excellent tensile strength and wear resistance
To provide a rubber-silica composite powder capable of obtaining a product
It is to be. [0009] Means for Solving the Problems The present inventors have set forth the above-mentioned section.
I have been working hard to solve the problem. As a result,
Rubber latex using a nonionic emulsifier, silica and
By mixing the cationic active agent, the cationic active
The rubber and silica in the rubber latex are separated by the action of the surfactant.
A uniform coagulate is formed and such agglomerates are dispersed microscopically
To obtain a mixed liquid in a dry state.
As a result, composite particles in which silica is uniformly dispersed in rubber are obtained.
And the composite particles thus obtained
Rubber-silica composite powder comprising the cationic activator
Rubber-silicone obtained by spray-drying the mixture containing no
Rubber set obtained by using this compared to Rica composite powder
The ability to significantly improve the rubber properties of the product
And completed the present invention. That is, the present invention uses an anionic emulsifier.
Rubber latex (hereinafter simply referred to as rubber latex)
), Spray drying a mixture of silica and cationic activator
Rubber characterized by comprising composite particles obtained by
Silica composite powder (hereinafter also simply referred to as composite powder)
You. [0011] DESCRIPTION OF THE PREFERRED EMBODIMENTS Rubber-silica composite of the present invention
Powder is a rubber latex using an anionic emulsifier,
Spray dried mixture of silica and cationic activator
Consisting of composite particles. Hereinafter, the present invention will be described in detail. In the present invention, the rubber latex is an anio
Uses rubber latex obtained by using a rubber-based emulsifier
Is done. Specifically, it is stabilized with an anionic emulsifier.
Using natural rubber latex or anionic emulsifier
Rubber latex produced by emulsion polymerization
It is. The anionic emulsifier includes stearyl
Fatty acid soaps such as sodium phosphate and sodium rosinate
Is typical. The rubber component in the rubber latex is specifically
For example, natural rubber (NR) latex, isop
Ren rubber (IR) latex, butadiene rubber (BR)
Latex, styrene butadiene rubber (SBR) latex
Box, chloroprene rubber latex, butyl rubber latex
Butter, nitrile butadiene rubber latex, etc.
When used for tire applications, SBR
Preferably, latex is used. In the present invention, as rubber latex
Is preferably a rubber latex produced by emulsion polymerization.
No. Further, as a rubber latex, amino groups,
Modified rubber latex with a functional group such as epoxy group introduced
Can be used. Further, process oil is added to the rubber latex.
Oil-extended rubber latex mixed with
You. Rubber latex used in the present invention
In, the content of the rubber component is not particularly limited, silica and
Suitable for spray drying depending on the mixing amount with the cationic activator, etc.
What is necessary is just to adjust suitably so that it may become an appropriate solid content concentration. Normal
The rubber component content is in the range of 10 to 30% by weight.
It is suitable. The silica used in the present invention is a known silica.
Is used without particular limitation. For example, dry silicon
Mosquito, wet silica, sol-gel method silica, colloidal silica
And mosquitoes. Generally, the above-mentioned fumed silica is made of silicon tetrachloride.
It can be obtained by burning in an oxyhydrogen flame,
Lica is obtained by neutralizing sodium silicate with mineral acids.
Precipitated silica (precipitated silica) or gel
Silica (gel method silica) is typical. In addition, sol
-Gel-processed silica is
Silicon alkoxides such as xysilane
Obtained by hydrolysis in aqueous organic solvents
be able to. Of the above-mentioned silicas, in the present invention,
Uses wet-process silica with excellent productivity, especially precipitated silica
Preferably. The minerals used to neutralize sodium silicate
Using aluminum sulfate as part or all of the acid
Precipitation method rich in metal salts obtained by neutralization reaction
Silica can also be used. The above silica is used as a filler for rubber.
Considering that, the specific surface area is 50-500m²/ G, absorption
Oil volume is 100-400cm³/ 100g is preferred
Used appropriately. In the present invention, specific surface area and absorption
The amount of oil is a value measured by the method described in Examples described later.
It is. The silica used in the present invention is a rubber latex.
Or wet with a cationic surfactant before mixing.
Method, dry method, etc., using a known silane
It may be treated with a coupling agent. In addition,
Tex, when adjusting the mixture with the cationic activator,
Can be treated by adding the silane coupling agent
It is. The cationic activator used in the present invention comprises:
Compounds that become active cations when dissolved in water
Objects are used without any restrictions. For example, 1st to 4th grade ammo
Compounds having a nickel base are typical. Also, the above
Chloride ion is an anion in which the active ion forms a salt.
And bromine ions are common. [0027] As the cationic activator, in one molecule
Lauryl group, dodecyl group, cetyl group, stearyl group,
Having an alkyl group such as an oleyl group as a hydrophobic group;
Cationic Field Having Grade Ammonium Salt as Hydrophilic Group
Surfactant, containing the hydrophilic group in the main chain of the polymer, or
A cationic polymer having a structure in which the hydrophilic group is branched
Which is preferred. Specific examples of the cationic surfactant include:
Alkyl ammonium salt, alkyl methyl ammonium
Salt, alkyl dimethyl ammonium salt, alkyl trim
Thilammonium salt, alkyl dimethyl ethyl ammonium
Salt, dialkyldimethylammonium salt, alkyl
Dimethylbenzylammonium salt, alkylpyridinium
Salt, triethanolamine and difatty acid
Quaternary salt, N-hydroxyethyl-N-methyl-propa
Diamine fatty acid monoester monoamide salts, etc.
I can do it. Of these, alkyl dimethyl ammonium
Alkyl tertiary ammonium salts such as
Thilammonium salt, dialkyldimethylammonium
And quaternary alkyl ammonium salts such as salts.
You. As the cationic polymer, for example,
For example, those obtained by polymerizing the above-mentioned monomer having a hydrophilic group are listed.
Tertiary and quaternary ammonium salts as hydrophilic groups
Preferably obtained by polymerizing the monomer
Is done. Further, a monomer having a primary to tertiary amine group
Polymerized materials may be used. That is, these are converted into acidic aqueous solutions.
By dissolving, the amine group becomes an ammonium base
Act as a cationic polymer. In addition,
Copolymerized with other monomers as long as the effect of
May be done. Specific examples of the cationic polymer include:
Polyethyleneimine, polyvinylamine, polyvinylpyrene
Lysine, polyamine sulfone, polyallylamine, poly
Diallylmethylamine, polyamidoamine, polyamino
Alkyl acrylate, polyaminoalkyl methacryl
Rate, polyaminoalkylacrylamide, polyepo
Xyamine, polyamide polyamine, polyester poly
Amine, dicyandiamide / formalin condensate, polya
High content such as condensates of alkylene polyamine and dicyandiamide
And their ammonium salts,
Methyl ammonium chloride, polyvinylpyridinium
Muchloride, polymethacrylic acid methyl chloride
And quaternary ammonium salts such as ido. Of these, polyvinylamine, polya
Lilamine, polydiallylmethylamine, polyepoxy
Amines and their ammonium salts, polydiallyldimethyl
Luammonium chloride, polyvinylpyridinium chloride
Loride is preferred. In addition, the above-mentioned cationic polymer
The average molecular weight should be 3,000 to 1,000,000.
Is preferred. In the present invention, the mixture is a rubber latex
By mixing silica, silica and cationic activator.
Can be obtained. The adjustment method is particularly limited,
However, if a typical adjustment method is shown as an example,
Method. (1) After mixing rubber latex and silica, cationic
Those who mix the activator as it is / or as an aqueous solution
Or rubber latex in aqueous solution of cationic activator
A method of mixing a mixed solution of silica and silica. (2) After mixing silica and a cationic activator in water,
Mixing rubber latex with rubber latex
Water mixed with silica and cationic activator in water
How to mix the solution. (3) rubber latex, silica and cationic activator
How to mix at the same time. As described above, in the present invention, the rubber rubber
Tex is stabilized by an anionic emulsifier
When a cationic surfactant is mixed, a part of rubber or
All coagulate with the silica. Therefore, in the present invention, the above (1),
When the method (2) coagulates the rubber, a uniform rubber
Preferred because a silica composite is more easily obtained,
The method (2) is to selectively coagulate rubber on the silica surface
Most preferred. In the present invention, the rubber latex
The coagulation ratio is not particularly limited, but the rubber
So that 60% by weight or more of the rubber component in
It is preferable to adjust the addition amount of the cationic activator,
Coagulate 70% by weight or more, and further, 80% by weight or more
It is best to adjust the amount of cationic activator
preferable. Specifically, the amount of the cationic activator used
Is based on 100 parts by weight of rubber component in rubber latex
0.1 to 20 parts by weight, preferably 0.5 to 20 parts by weight
Parts by weight, more preferably 1.0 to 20 parts by weight.
Preferably. The solidification ratio is determined in advance before adjusting the mixture.
From the rubber latex concentration, the total rubber in the sample mixture
Calculate the weight, and then mix the mixture with a quantitative filter paper.
Filter and pass through the filter paper to remove the rubber latet present in the filtrate.
Measure the rubber weight of the box, the ratio to the total rubber weight
Can be obtained as Rubber-silica composite obtained in the present invention
Powder simply spray-drys conventional rubber latex and silica
Tensile strength and wear resistance compared to those obtained by
Can be mixed before spray drying as described above.
It is important that the rubber is co-coagulated with silica in the liquid mixture.
It is thought that it is a factor. In the present invention, when the above mixing is performed,
The mixing method is not particularly limited.
Using a general dispersing device such as a disperser or a homogenizer
And a method of mixing. The silica used in the present invention can be used as it is.
May be used as an aqueous suspension.
It is preferably used as a suspension. That is, with an aqueous suspension
By doing so, dispersion of silica in rubber latex is easy.
It not only makes it easier, but also makes it possible to adjust the average particle size of silica.
It will be easier. The silica concentration in the aqueous suspension is usually 1
Those having a concentration of about 30% by weight are preferably used. In the preparation of the above aqueous suspension of silica,
When using wet silica, the produced silica is subjected to a drying step.
Slurry or wet cake without passing through
It is preferred to prepare the aqueous suspension using
That is, by not passing through the drying step, drying shrinkage during drying
Avoid the disadvantage of poor dispersion due to self-coagulation
Can be. In the present invention, rubber latex, silicone latex
Temperature and pH when mixing with cationic surfactants
Not limited to For example, the temperature is 10 ° C to 80 ° C.
Generally, the above pH depends on the properties of the cationic activator.
What is necessary is just to select suitably while considering it. In preparing the mixture of the present invention,
To adjust the solid ratio, use an acid such as sulfuric acid or salt in combination
It can also be added. In addition, about pH after mixing
Also, adjust the pH to 7 or less by adding an acid such as sulfuric acid.
Can be. In the present invention, the rubber latex
The amount of the mosquito is not particularly limited,
It may be appropriately determined according to the intended use. For example, rubber
100 parts by weight of the rubber component in the tex, silica 5
0 to 500 parts by weight, preferably 100 to 400 parts by weight,
Most preferably, it is 150 to 300 parts by weight. Average particle size of silica used in the present invention
Although the diameter is not particularly limited, the obtained silica-filled rubber
Taking into account physical properties such as strength and hardness,
Is preferably adjusted to the range described above. That is, the average particle size
To 0.1 μm or more, silica self-aggregation
Can prevent poor dispersion due to the
The degree becomes good. On the other hand, the average particle size should be 50 μm or less.
The dispersion of silica in the resulting silica-filled rubber
Is good and a silica-filled rubber with high strength is obtained.
be able to. The average particle diameter of the silica is
It is a value measured using a laser diffraction / scattering method. In particular, the obtained rubber-silica composite powder is
When used for tire applications, the average particle size of the silica is
The thickness is preferably 1 μm to 30 μm. The average particle diameter of the silica is as follows:
Dry grinding using a micromill, jet mill, etc.
Method, homogenizer in aqueous suspension, colloid mill, high
Wet pulverization using a pressure homogenizer etc.
Can be adjusted. What is the timing for adjusting the average particle diameter of silica?
But not limited, rubber latex or cationic
It may be adjusted before mixing with the activator,
Or after mixing with a cationic surfactant
good. There are no restrictions on the conditions for using each disperser.
And adjust appropriately so as to obtain the desired average particle size.
Just do it. In the present invention, the effects of the present invention are further
For example, filling with carbon black
Additives such as antioxidants, antioxidants, activators and plasticizers
You may. In the present invention, the above silica and rubber latex are used.
Mixtures of water and cationic surfactants are spray dried
Spray-dried using a machine, from the composite particles according to the present invention
Rubber-silica composite powder can be obtained. The above-mentioned mixture is filtered before spray drying.
Excess, washing, wet cake and dispersing the wet cake in water
May be used. The spray drying method includes a nozzle type, a
Disk type etc. can be mentioned, but nozzle type spray drying
In the case of a dryer, by controlling the spray nozzle diameter
Suitable for controlling the particle size
It is. Further, the particles of the rubber-silica composite powder of the present invention
The diameter is adjusted according to the solid concentration of the mixture to be spray-dried.
Can also be adjusted. Rubber-silicone having desired particle size
To obtain mosquito composite powder, for example, the solid
So that the concentration is 80 g / l to 250 g / l.
Adjustment by diluting or concentrating the mixture
Can be. The spray drying conditions depend on the spray dryer used.
Size, type, concentration of solids in the mixture, viscosity, flow rate, etc.
The drying temperature should be from 50 ° C.
250 ° C is appropriate, and within this drying temperature,
Set other drying conditions to obtain a dry powder.
Is desirable. For example, a hot air temperature of 150 ° C.
250 ° C and outlet hot air temperature will be 50 ° C to 150 ° C
Thus, the supply amount of the mixed solution may be adjusted. Further, a dry atmosphere in which the mixture is sprayed is used.
Heating air; inert gas such as nitrogen and carbon dioxide
Various types of air flows are generally used. But the resulting go
Risk of rubber deterioration and dust explosion
Considering that, when the amount of rubber is large, air can be avoided.
Preferably, the oxygen concentration is 8% by volume or less by an inert gas,
Preferably, lower the oxygen concentration so as to be 5% by volume or less.
It is preferable to use a gas atmosphere. Most preferably,
This is an embodiment performed in an inert gas atmosphere. Further, unreacted steam is added to the dry gas.
The combustion method
Or dry carbon gas after treatment by activated carbon adsorption method
It can be used in circulation. The rubber-silica composite powder of the present invention is
When the composite particles are observed with an electron microscope, the cationic activity
Compared to the surface of conventional composite particles containing no agent.
Prominent irregularities probably due to co-coagulation of silica and silica
The feature is that it can be seen. The composite particles obtained by the above method
The particle size of the rubber-silica composite powder of the present invention is particularly limited.
No, but the average particle size by the shaking method is 50 to 5
A spherical shape of 00 μm is preferred. Further, in order to improve the handleability,
The rubber-silica composite powder is extruded into a granulator,
Can be molded into granules using a
Wear. Rubber-silica obtained by the method of the present invention
The composite powder is directly converted into a rubber composition by a kneading operation.
Or knead with unfilled rubber to obtain the desired silica concentration.
The rubber composition may be adjusted to a certain degree. [0063] EXAMPLES In order to explain the present invention more specifically, the following will be described.
Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.
It is not limited to these examples. The implementation
Various physical properties in Examples and Comparative Examples were determined by the following methods.
It was measured. (1) Average particle size A) Silica Light scattering diffraction type particle size distribution analyzer (Coulter,
The volume-based median diameter is measured using a H.L.
This value was adopted as the average particle size. B) Silica-rubber composite powder 500 using a shaker (manufactured by Tanaka Chemical Machine Co., Ltd.)
300, 212, 150, 106, 53, 45, 25μ
Set the m-mesh sieve (JIS Z8801) and
Add 20 g of material and shake for 7 minutes, then sample on each sieve
Measure the weight, and the residual rate on the sieve
Particle size D to be 50%₅₀I asked. (2) Specific surface area According to JIS K6220, BET one point method
Was. (3) Oil absorption It was determined according to JIS K6220. (4) Silica content Thermal analyzer TG / DTA (TG / D manufactured by Seiko Denshi Kogyo)
After thermal decomposition of the dried sample in air using TA320)
The residue rate of the and the weight loss rate up to 150 ° C were measured, and
It was calculated using the equation. The measurement conditions were as follows: heating rate 2 in air
0 ° C / min, at ultimate temperature of 600 ° C, when held at 600 ° C
In 20 minutes. Silica content (%) = residual combustion ratio / [10
0- (weight loss rate up to 150 ° C.)] (5) 300% modulus, tensile strength, elongation It was measured by the tensile stress test method of JIS K6301. (6) Wear reduction Using an Akron abrasion tester, after 1000 preliminary rubs
It was determined from the weight and the weight loss after 1000 rubs. The silica used in the present invention is as follows:
It was synthesized by the method. (Silica synthesis method) 1m with temperature controller³Reaction vessel
Sodium silicate solution (SiO₂Concentration: 10 g / L,
Molar ratio: SiO₂/ Na₂O = 3.43) 230 L
And heated to 85 ° C. Then, 22 w / v% sulfuric acid 7
3L and sodium silicate aqueous solution (SiO₂Concentration: 90 g /
L, molar ratio: SiO₂/ Na₂O = 3.43) 440 L
At the same time over 120 minutes. After aging for 10 minutes, 2
16 L of 2% w / v sulfuric acid was charged over 15 minutes. Above
The reaction temperature is maintained at 85 ° C and the reaction solution is constantly stirred.
While the pH of the reaction solution is 3.3
Got a rally. This is filtered, washed with water, and wet with silica cake.
did. The specific surface area of the obtained silica was 195 m²
/ G, and the oil absorption was 210 ml / 100 g. Embodiment 1 Without drying the silica wet cake synthesized by the above method
Mix pure water so that the silica solids concentration becomes 13%.
And a poly (diallylmethyl) having a weight average molecular weight of 20,000.
100% by weight of silica solid content
3 parts by weight with respect to the mixture, and 10 minutes using a homogenizer.
The mixture was stirred and crushed for a while to obtain an aqueous suspension of silica. Got
The average particle size of the silica in the aqueous suspension was 17 μm.
Was. Next, silica is added to 100 parts by weight of rubber.
Add SB to the aqueous suspension of silica so that it becomes 200 parts by weight.
Add R latex (solid content: 20%) with stirring
Was. In the rubber latex in the obtained mixed solution
The rubber had a solidification ratio of 100% (polydiallylme
Tilammonium chloride compounding amount is rubber 100 weight
6 parts by weight per part). The obtained mixed solution was put in a spray drying device.
Liquid mixture so that the mouth temperature is 220 ° C and the outlet temperature is 120 ° C
Dry with heated nitrogen gas while adjusting the supply amount of
Thus, a rubber-silica composite powder (A) was obtained. The obtained rubber
-Silica content of silica composite powder (A), average particle diameter
(D₅₀) Are shown in Table 1. The rubber-silica composite powder (A) is shown in Table 2.
SBR, silane coupling agent
(KBE-846, manufactured by Shin-Etsu Chemical Co., Ltd.), Paraffinwa
And stearic acid, add the Banbury mixer
ー (Toyo Seiki Labo Plast Mill Model 100C Miki
Kneading at 150 ° C for 3 minutes using Certype B-250)
Thus, a rubber composition (A) was obtained. This rubber composition (A)
Zinc flower, anti-aging agent so that the compounding amount shown in Table 2
(Nocrack 6C, Ouchi Shinko Chemical Co., Ltd.), accelerated vulcanization
(Noxeller CZ, Ouchi Shinko Chemical Co., Ltd.) and sulfuric acid
Add yellow and use a Banbury mixer at 70 ° C for 1 minute
Kneading was performed to obtain a rubber composition (B). This rubber composition
(B) is press vulcanized at 160 ° C for 15 minutes to produce a test piece.
And each physical property was measured. Table 3 shows the results. Embodiment 2 In Example 1, the polydiallylmethylammonium
Polydia having a weight average molecular weight of 40,000 instead of chloride
Except for using dimethyldimethyl chloride
The same operation as in Example 1 was performed to obtain a rubber-silica composite powder.
(B) was obtained. The rubber mixture in the mixture before spray drying was
The solidification ratio of the rubber in the tex was 100% (poly
The amount of diallyl dimethyl ammonium chloride
6 parts by weight for 100 parts by weight of the rubber). The rubber-silica composite powder (B)
Lica content, average particle size (D₅₀) Are shown in Table 1.
Silica-filled rubber (B) was prepared by adding various additives as in Example 1.
Are mixed, kneaded and vulcanized to prepare test specimens, and each physical property is measured.
Specified. Table 3 shows the results. Embodiment 3 In Example 1, the polydiallylmethylammonium
Cetyltrimethylammonium broth instead of chloride
The same operation as in Example 1 was performed except for using the
A silica-silica composite powder (C) was obtained. The rubber mixture in the mixed liquid before spray drying was
The coagulation ratio of the rubber in the tex was 80% (cetyl
The amount of trimethylammonium bromide is rubber 10
6 parts by weight with respect to 0 parts by weight). The rubber-silica composite powder (C)
Lica content, average particle size (D₅₀) Are shown in Table 1.
Various rubber-silica composite powders (C) were prepared in the same manner as in Example 1.
Add additives, knead and vulcanize to make test specimens,
The properties were measured. Table 3 shows the results. Embodiment 4 In Example 1, 100 parts by weight of rubber was mixed with silica 3
00 parts by weight of SBR in the aqueous suspension of silica.
Latex (solid content: 20%) was added with stirring
Except for the above, the same operation as in Example 1 was performed to obtain a rubber-silica composite.
Powder (D) was obtained. The rubber mixture in the mixture before spray drying was
The solidification ratio of the rubber in the tex was 100% (poly
The amount of diallyl methyl ammonium chloride is rubber
9 parts by weight for 100 parts by weight). The rubber-silica composite powder (D)
Lica content, average particle size (D₅₀) Are shown in Table 1.
The rubber-silica composite powder (D) had the compounding amount shown in Table 2.
In this manner, various additives are blended and mixed in the same manner as in Example 1.
A test piece was prepared by kneading and vulcanizing, and each physical property was measured. result
Are shown in Table 3. Comparative Example 1 The silica wet cake used in Example 1 was dried, and the silica powder was dried.
(A). The obtained silica powder (A) had the distribution shown in Table 2.
SBR, silane coupling agent (K
BE-846, manufactured by Shin-Etsu Chemical Co., Ltd.), paraffin wax
And stearic acid in a Banbury mixer
(Toyo Seiki Labo Plastomill Model 100C Mixer
-Type B-250) and kneaded at 150 ° C for 3 minutes,
A rubber composition (A) was obtained. The compounding amount shown in Table 2 in this rubber composition (A)
Zinc flower, anti-aging agent (Nocrack 6C,
Ouchi Shinko Chemical Co., Ltd.), vulcanization accelerator (Noxeller C
Z, Ouchi Shinko Chemical Co., Ltd.) and sulfur
Knead at 70 ° C for 1 minute using a Barry mixer.
The product (B) was obtained. This rubber composition (B) is heated at 160 ° C.
Prepare test specimens by press vulcanization for 15 minutes and measure each physical property
did. Table 4 shows the results. Comparative Example 2 Silica concentration using the silica wet cake used in Example 1
Is mixed with pure water so that the concentration becomes 13%.
And stirred for 10 minutes to obtain an aqueous suspension of silica.
Was. The average particle size of silica in the obtained aqueous suspension is 17
μm. Next, silica is added to 100 parts by weight of rubber.
Add SB to the aqueous suspension of silica so that it becomes 200 parts by weight.
Add R rubber latex (solid content: 20%) while stirring
Added. No rubber in rubber latex in mixed solution
Had not solidified. The obtained mixture was used in the same manner as in Example 1.
To obtain a rubber-silica composite powder (E). The rubber-silica composite powder (E) was
Lica content, average particle size (D₅₀) Are shown in Table 1. The rubber-silica composite powder (E) has
Various additives are blended, kneaded and vulcanized in the same manner as in 1.
Was prepared, and each physical property was measured. Table 4 shows the results. [0093] [Table 1] [Table 2] [Table 3][Table 4] The rubber-silica composite powder of the present invention has
Rubber latex, silica,
Composite granules obtained by spray-drying a mixture of thionic activators
Of rubber latex and silica
Conventional rubber-silica composite powder obtained by spray drying the liquid
Rubber with superior tensile strength and abrasion resistance compared to powder
A composition can be provided. Therefore, conventionally, the use of silica has a high resistance.
For tires, etc., where lack of wear and tensile strength were
It is effective in use. Also obtained by spray drying
Mass production is easy and its practical
The value is extremely high.

Claims (1)

Claims: 1. A rubber comprising a composite particle obtained by spray-drying a mixture of a rubber latex using an anionic emulsifier, silica and a cationic activator.
Silica composite powder.