JP2014122134A - Surface-treated calcium carbonate and rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide surface-treated calcium carbonate which, when blended into rubber, can remarkably improve vibration characteristics thereof, and to provide a rubber composition comprising the same.SOLUTION: Provided is surface-treated calcium carbonate, wherein the surface of calcium carbonate having an average primary particle diameter of 0.01 to 10.0 μm is treated with a quarternary ammonium salt compound and resin acids, wherein a surface treatment amount of the quarternary ammonium salt compound is 0.05 to 1 mass part relative to 100 mass parts of calcium carbonate. A rubber composition contains 5 to 200 mass parts of the surface-treated calcium carbonate blended into 100 mass parts of rubber.

Description

  The present invention relates to surface-treated calcium carbonate and a rubber composition containing the same.

  Conventionally, silica, carbon black, calcium carbonate, and the like have been added to rubber as a rubber reinforcing agent.

  In Patent Document 1, the surface of calcium carbonate is treated with quaternary ammonium salt and surface-treated calcium carbonate surface-treated with fatty acids in rubber so that it has excellent scorch stability, processability, etc., and high hardness. It is disclosed that a rubber composition having high impact resilience can be obtained.

JP 2012-41524 A

  By blending the surface-treated calcium carbonate disclosed in Patent Document 1 with rubber, it is possible to improve the vibration-proof characteristics of the blended rubber. As a method for further enhancing the vibration isolation characteristics, it is conceivable to increase the particle diameter of calcium carbonate. However, when the particle size of calcium carbonate is increased, problems such as deterioration of the mechanical properties of the resulting rubber may occur.

  An object of the present invention is to provide a novel surface-treated calcium carbonate and a rubber composition containing the same, which can drastically improve the vibration damping characteristics of the rubber by blending with the rubber.

  In the surface-treated calcium carbonate of the present invention, the surface of calcium carbonate having an average primary particle diameter of 0.01 to 10.0 μm is surface-treated with a quaternary ammonium salt compound and a resin acid. The amount of treatment is 0.05 to 1 part by mass with respect to 100 parts by mass of calcium carbonate.

  The average primary particle diameter of calcium carbonate in the present invention is preferably in the range of 0.01 to 10.0 μm, more preferably in the range of 0.02 to 1.0 μm, and still more preferably 0.05 to The range is 0.5 μm. When the average primary particle diameter is too large, there are cases where a sufficient reinforcing effect cannot be obtained when blended with rubber. On the other hand, if the average primary particle size is too small, dry agglomeration may occur, dispersibility in rubber may be reduced, and the reinforcing effect may be impaired.

  The average primary particle diameter of calcium carbonate can be measured with, for example, a scanning electron microscope.

  The treatment amount of the quaternary ammonium salt compound in the surface-treated calcium carbonate of the present invention is 0.05 to 1 part by mass, preferably 0.1 to 0.8 part by mass with respect to 100 parts by mass of calcium carbonate. More preferably, it is 0.1 to 0.5 parts by mass. If the treatment amount of the quaternary ammonium salt compound is too small, there may be a case where sufficient anti-vibration characteristics cannot be obtained. If the treatment amount of the quaternary ammonium salt compound is too large, the scorch time is shortened and the storage stability is improved. May decrease.

  The treatment amount of the resin acids in the surface-treated calcium carbonate of the present invention is preferably 0.1 to 8 parts by mass, more preferably 1 to 5 parts by mass, and further preferably 100 parts by mass of calcium carbonate. 2 to 5 parts by mass. If the treatment amount of the resin acid is too small, the calcium carbonate particles may dry and agglomerate and the dispersibility may be reduced. If the treatment amount of the resin acid is too large, the rubber becomes soft and the reinforcing property may be lowered. is there.

  The treatment amount of the quaternary ammonium salt compound and the treatment amount of the organic acid can be appropriately adjusted depending on the primary particle diameter of calcium carbonate to be treated.

  The rubber composition of the present invention is characterized by blending 5 to 200 parts by mass of the surface-treated calcium carbonate of the present invention with respect to 100 parts by mass of rubber.

  The surface-treated calcium carbonate of the present invention can drastically improve the vibration-proof property of rubber by being blended with rubber.

  The rubber composition of the present invention contains the surface-treated calcium carbonate of the present invention, and is excellent in vibration proofing properties.

  Hereinafter, the surface-treated calcium carbonate and rubber composition of the present invention will be described in more detail.

<Calcium carbonate>
The calcium carbonate used as the raw material used for the surface-treated calcium carbonate of the present invention is not particularly limited, and for example, conventionally known calcium carbonate can be used. Such materials include synthetic (precipitating) calcium carbonate, heavy calcium carbonate, and the like.

  Synthetic (precipitating) calcium carbonate can be obtained by a known method such as lime milk-carbon dioxide reaction method, calcium chloride-soda ash reaction method, lime milk-soda ash reaction method. An example of the lime milk-carbon dioxide reaction method is as follows. Raw limestone is mixed with coke or petroleum fuel (heavy oil, light oil), natural gas, LPG, etc. to obtain quick lime, which is hydrated and hydroxylated. Calcium carbonate can be produced by bubbling and reacting carbon dioxide gas generated during co-firing with calcium slurry. Desired fine particles can be obtained by setting the conditions for the carbon dioxide reaction.

  Heavy calcium carbonate raw material is a publicly known raw calcium carbonate that is produced by using a roller mill, a high-speed rotary mill (impact shear mill), a container drive medium mill (ball mill), a medium stirring mill, a planetary ball mill, a jet mill, etc. It can be prepared by grinding by a dry or wet method.

<Quaternary ammonium salt compound>
Examples of the quaternary ammonium salt compound in the present invention include tetraalkyl quaternary ammonium salts. As these compounds, conventional compounds can be used regardless of trimethyl type, dialkyl type, benzyl type or the like. For example, tetramethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, octyltrimethylammonium chloride, octyltrimethylammonium bromide, decyltrimethylammonium chloride, decyltrimethylammonium bromide, n-dodecyltrimethylammonium chloride, n-dodecyl Trimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, behenyltrimethylammonium chloride, cocoalkyltrimethylammonium Chloride, beef tallow alkyl trimethyl ammonium chloride, didecyl dimethyl ammonium chloride, dioleyl dimethyl ammonium chloride, dioctadecyl dimethyl ammonium chloride, dicoco alkyl dimethyl ammonium chloride, di-cured tallow alkyl dimethyl ammonium chloride, coco alkyl dimethyl benzyl ammonium chloride, tetradecyl Dimethylbenzylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium chloride, benzyltributylammonium chloride, trimethylphenylammonium chloride, coconut alkylbis (2-hydroxyethyl) methylammonium chloride, polyoxyethylene coconut alkyl ammonium Chloride, oleylbis (2-hydroxyethyl) methylammonium chloride, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, di-cured tallow alkyldimethylammonium acetate, 1,8-diaza-bicyclo (5,4,0) undecene-7 -Methylammonium methosulfate, cetylpyridium sulfate, N, N-diacyloxyester-N-hydroxyethyl-N-methylammonium methylsulfate, trimethylbenzylammonium benzoate, 1-methyl-1-hydroxyethyl-2-tallow Examples thereof include alkyl imidazolium chloride. In addition, trioctyl ammonium chloride, trioctyl ammonium bromide, tridecyl ammonium chloride, tridecyl ammonium bromide, tridodecyl ammonium chloride, tridodecyl ammonium bromide, trihexadecyl ammonium chloride, trihexadecyl ammonium bromide, trioctadecyl ammonium chloride , Trioctadecyl ammonium bromide, coconut amine acetate, stearylamine acetate, tetradecylamine acetate, octadecylamine acetate, coconut alkylamine acetate, hardened beef tallow alkyl acetate, tallow alkyl acetate, tallow diamine dioleate, Amine salts such as coconut diamine diadipate can also be used.

<Resin acids>
The surface-treated calcium carbonate of the present invention is surface-treated with the quaternary ammonium salt compound and surface-treated with resin acids.

  Examples of the resin acid used in the present invention include abietic acid, lepopimaric acid, neoabietic acid, pultrinic acid, dehydroapitic acid, dihydroabietic acid, tetraabietic acid, dextropimaric acid, isodextropimaric acid, and the like. Examples thereof include a polymer, a polymer thereof, a disproportionated rosin, a hydrogenated rosin, a polymerized rosin, a salt thereof (alkali metal salt, alkaline earth metal salt) or ester.

<Other surface treatment agents>
In addition to these resin acids, existing surface treatment agents such as fatty acids, lignins, silicic acids, and silane coupling agents can be used in combination.

  Examples of the fatty acids include saturated and unsaturated fatty acids having 6 to 24 carbon atoms, salts or esters thereof, and the like.

  Examples of the saturated or unsaturated fatty acid having 6 to 24 carbon atoms include stearic acid, palmitic acid, lauric acid, behenic acid, oleic acid, erucic acid, linoleic acid, and the like. In particular, stearic acid, palmitic acid, lauric acid, and oleic acid are preferably used. You may use these in mixture of 2 or more types.

  Examples of the fatty acid salt include alkali metal salts and alkaline earth metal salts.

  Examples of fatty acid esters include esters of saturated or unsaturated fatty acids having 6 to 24 carbon atoms with lower alcohols having 6 to 18 carbon atoms.

  Examples of lignins include lignin sulfonic acid, modified lignin sulfonic acid, partially desulfonated lignin sulfonic acid salts (alkali metal salts, alkaline earth metal salts), and mixed salts containing one or more of these. May be processed.

  Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ -Methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β Aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyl Trimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, bis- (3- [triethoxysilyl] -propyl) -tetrasulfane (TESPT), bis- (3- [triethoxysilyl ] -Propyl) -disulphane.

<Surface treatment>
In the present invention, the surface of calcium carbonate is surface-treated with the quaternary ammonium salt compound and the resin acids. The order of surface treatment is not particularly limited, and after treating the resin acids, the quaternary ammonium salt compound may be treated, or after treating the quaternary ammonium salt compound, the resin acids may be treated. Good. Moreover, you may process a quaternary ammonium salt compound and resin acids simultaneously.

  However, when synthetic (precipitating) calcium carbonate having a small average primary particle size is used as calcium carbonate, calcium carbonate tends to aggregate. Therefore, after treating the resin acids, the quaternary ammonium salt compound can be treated. preferable. Examples of the method for treating resin acids include the following methods.

  The resin acid is saponified while heating in an aqueous alkali metal solution such as an aqueous NaOH solution or an aqueous KOH solution to form a solution of a metal salt such as an Na salt or K salt. Next, an aqueous suspension of calcium carbonate is heated to 30 to 50 ° C. in advance, and an alkali metal aqueous solution of resin acid is added to the suspension and mixed by stirring. Surface treatment with resin acid.

  Moreover, it can also process using resin acids, without saponifying as mentioned above. For example, calcium carbonate can be treated with a resin acid by stirring it while heating it to a temperature equal to or higher than the melting point of the resin acid, adding the resin acid thereto, stirring the mixture, and mixing.

  The method for surface-treating the quaternary ammonium salt compound is not particularly limited, and various surface treatment methods can be used.

  In the case of treating a quaternary ammonium salt compound with calcium carbonate treated with resin acids, it can be treated by the following method.

  When the calcium carbonate treated with resin acid is a dry powder, for example, while stirring this calcium carbonate powder in a mixer, a quaternary ammonium salt compound is dropped or sprayed using a spray or the like. Thus, the surface treatment of the quaternary ammonium salt compound can be performed on the surface of calcium carbonate. In this case, you may heat-dry after surface treatment as needed.

  When calcium carbonate treated with resin acids is obtained in the form of a suspension, a quaternary ammonium salt compound is added to the suspension to adsorb the quaternary ammonium salt compound on the surface of calcium carbonate. Surface treatment is possible. Surface treatment calcium carbonate is obtained by drying after the treatment.

  When calcium carbonate treated with resin acids or calcium carbonate treated with a quaternary ammonium salt compound is a suspension, a wet grinder such as a stirrer, bead mill, sand mill, etc. is used for uniform treatment. You may process using.

  The specific surface treatment method has been described above, but the surface treatment method for the surface-treated calcium carbonate of the present invention is not limited to the above-described one.

<Rubber composition>
Examples of the natural rubber and synthetic rubber used in the present invention include the following.

  Natural rubber is a rubbery polymer obtained from natural plants, and the shape, color tone, etc. are not particularly limited as long as it has a cis-1,4-polyisoprene structure in terms of chemical structure.

  Synthetic rubbers include, for example, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, butyl rubber, halogenated butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, fluorine rubber, chlorosulfonated polyethylene, epichloro Examples include hydrin rubber and polysulfide rubber. Moreover, the latex mainly composed of the rubber can be used. Furthermore, thermoplastic elastomers such as polystyrene-based thermoplastic elastomers, polypropylene-based thermoplastic elastomers, polydiene-based thermoplastic elastomers, chlorine-based thermoplastic elastomers, and engineering plastic-based elastomers can also be used.

  The rubber composition of the present invention can be produced by blending the surface-treated calcium carbonate of the present invention with natural rubber or synthetic rubber.

  In addition to the rubber component and the compounding component, the rubber composition of the present invention includes various usual rubber compounding agents, for example, other fillers such as carbon black, silica, clay and other calcium carbonate, silane coupling Additives, vulcanization accelerators, activators, oil, zinc white, stearic acid, softeners, anti-aging agents, retarders and other additives, vulcanizing agents such as sulfur and vulcanization accelerators, etc. The blending amount can also be used as long as the effects of the present invention are not impaired.

  Examples of the vulcanization accelerator include diazoles such as di-2-benzothiazolyl disulfide (DM) and 2-mercaptobenzothiazole (M), N-cyclohexyl-2-benzothiazolylsulfenamide (CZ), N -Tert-butyl-2-benzothiazolylsulfenamide (NS), sulfenamides such as N, N-dicyclohexyl-2-benzothiazolesulfenamide (DZ), tetramethylthiuram monosulfide (TS), tetra Thiurams such as methylthiuram disulfide (TT), guanidines such as phenylguanidine (D), thiocarbamic acids such as zinc dimethylthiocarbamate (PZ), xanthates such as zinc isopropylxanthate (ZIX) Examples include vulcanization accelerators.

  As a method of blending surface-treated calcium carbonate with natural rubber or synthetic rubber, surface-treated calcium carbonate is blended while kneading the rubber with a closed kneader such as a Banbury mixer, pressure kneader, intermix, or open roll. The method of doing is mentioned.

  The rubber composition containing the surface-treated calcium carbonate of the present invention has a low dynamic magnification. Therefore, the rubber composition of the present invention is an anti-vibration rubber that requires a low dynamic magnification, such as an engine mount, liquid seal engine mount, body mount, cap mount, member mount, muffler mount, cab mount, diff mount, strut mount, Strut bar cushion, stabilizer bush, suspension bush, tension rod bush, lower ring bush, arm bush, sliding bush, damper pulley, torsional damper, chain damper, handle damper, center bearing support, steering rubber coupling, bump strapper, FF engine Roll stopper, muffler hanger, bumper rubber, bumper guard, helper rubber, spring seat, shock absorber, air Anti-vibration rubber for automobiles such as clutch rubber and radiator supporter, anti-vibration rubber for railway vehicles, anti-vibration rubber for industrial machinery, seismic isolation rubber for construction, seismic isolation rubber support, seismic isolation rubber, computer Damping dampers for general hard disks, damping dampers for general household electrical appliances such as washing machines, damping walls for buildings in the field of construction and housing, damping and damping devices such as damping (damping) dampers and seismic isolation devices It can be used suitably for the use etc. In addition, tire tread, sidewall, shoulder, inner liner, bead filler, carcass, belt, hose, sealing material, oil seal, float, soft ball, tennis ball, rubber plate, rubber tile boots, shoe sole, string protection It can be suitably used as a material, sports shoe, sponge product, rubber sealant, and the like.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to the following examples.

(Synthesis Example A)
Abietic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the resin acid for surface treatment of calcium carbonate. This resin acid was added to an aqueous sodium hydroxide solution, and heated and stirred at 90 ° C. to prepare an aqueous sodium solution of the resin acid.

  A slurry of synthetic calcium carbonate (solid content concentration 8% by weight) having an average primary particle size of 0.05 μm when observed with a scanning electron microscope was heated to 40 ° C. with good stirring. Into this slurry, 3 parts by weight of the above-mentioned sodium resinate aqueous solution as a resin acid and 100 parts by weight of calcium carbonate, an aqueous solution of quaternary ammonium salt (hexadecyltrimethylammonium chloride, manufactured by Wako Pure Chemical Industries, Ltd.), calcium carbonate 100 It added so that it might become 0.1 mass part of quaternary ammonium salt with respect to a mass part. After adding a sodium resinate aqueous solution to the calcium carbonate slurry, a quaternary ammonium salt aqueous solution was added. After addition, the mixture was stirred, dehydrated with a filter press, and dried at 80 ° C. using a box dryer. The obtained dried product was pulverized using a micron mill pulverizer to obtain surface-treated calcium carbonate.

(Synthesis Example B)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example A except that the amount of the quaternary ammonium salt was 0.3 parts by mass with respect to 100 parts by mass of calcium carbonate.

(Synthesis Example C)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example A except that the amount of the quaternary ammonium salt was 0.5 parts by mass with respect to 100 parts by mass of calcium carbonate.

(Synthesis Example D)
The surface is the same as in Synthesis Example B except that synthetic calcium carbonate having an average primary particle size of 0.08 μm is used and the amount of resin acid is 2.5 parts by mass with respect to 100 parts by mass of calcium carbonate A treated calcium carbonate was obtained.

(Synthesis Example E)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example D, except that synthetic calcium carbonate having an average primary particle size of 0.15 μm was used.

(Synthesis Example F)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example E except that the amount of the resin acid was 1 part by mass with respect to 100 parts by mass of calcium carbonate.

(Synthesis Example G)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example E except that the amount of the resin acid was 5 parts by mass with respect to 100 parts by mass of calcium carbonate.

(Synthesis Example H)
Instead of sodium resinate, a mixed fatty acid of oleic acid, stearic acid and palmitic acid (all manufactured by Wako Pure Chemical Industries, Ltd.) was added to a sodium hydroxide aqueous solution and heated and stirred at 90 ° C. Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example B except that sodium salt was used.

(Synthesis Example I)
A surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example H except that the surface treatment was not performed with a quaternary ammonium salt.

(Synthesis Example J)
A surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example B except that the surface treatment was not performed with a quaternary ammonium salt.

(Synthesis Example K)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example B except that the amount of the quaternary ammonium salt was 2 parts by mass with respect to 100 parts by mass of calcium carbonate.

(Synthesis Example L)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example D, except that the sodium salt of the mixed fatty acid used in Synthesis Example H was used instead of sodium resinate.

(Synthesis Example M)
A surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example D except that the surface treatment was not performed with a quaternary ammonium salt.

(Synthesis Example N)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example L, except that synthetic calcium carbonate having an average primary particle size of 0.15 μm was used.

(Synthesis Example O)
Surface-treated calcium carbonate was obtained in the same manner as in Synthesis Example M, except that synthetic calcium carbonate having an average primary particle size of 0.15 μm was used.

[Preparation of Calcium Carbonate Rubber Composition (Examples 1-7, Comparative Examples 1-8)]
100 parts by mass of the surface-treated calcium carbonate obtained in Synthesis Examples A to O above are blended with 100 parts by mass of natural rubber (trade name “SMR-L”), and further 5 parts by mass of zinc white with respect to 100 parts by mass of natural rubber. , 1 part by weight of stearic acid, 1.5 parts by weight of vulcanization accelerator CBS (N-cyclohexyl-2-benzothiazolylsulfenamide), and 2 parts by weight of sulfur are added and kneaded with two rolls. A vulcanized rubber was obtained.

[Preparation of rubber composition containing carbon black]
(Comparative Example 9)
An unvulcanized rubber was obtained in the same manner as in Example 1 except that FT grade carbon black (FT black, trade name “Asahi Thermal”) was used instead of the surface-treated calcium carbonate.

[Test of rubber composition]
Using the unvulcanized rubber press vulcanized sheets obtained in Examples 1 to 7 and Comparative Examples 1 to 9, Mooney viscosity, Mooney scorch time, and dynamic magnification were measured as follows.

<Mooney viscosity>
According to the method prescribed | regulated to JIS (Japanese Industrial Standard) K6300-1, it measured using the Mooney viscometer by Shimadzu Corporation. The test temperature was 100 ° C., the measurement was started 1 minute after preheating, and the viscosity after 4 minutes was measured.

<Mooney coach time>
According to the method prescribed | regulated to JIS (Japanese Industrial Standard) K6300-1, it measured using the Mooney viscometer by Shimadzu Corporation. The test temperature was 125 ° C., the measurement was started 1 minute after the preheating, and the time until the torque was increased by 5 points was measured.

<Dynamic magnification>
The dynamic magnification was determined from the dynamic spring constant (Kd) and static spring constant (Ks), and the ratio (Kd / Ks).

  The dynamic spring constant (Kd) was measured by using a dynamic viscoelasticity measuring apparatus (UPI Rheogel-4000) under the following conditions to measure E ′ (storage elastic modulus), which was defined as the dynamic spring constant (Kd). .

Temperature: 25 ° C
Dynamic strain: 20 μm
Initial strain: 2mm
Frequency: 100Hz
Test piece: 5w × 2t × 30l (distance between chucks 20mm)
The static spring constant (Ks) was determined from the following equation by measuring 25% low elongation stress.

Static spring constant Ks = 3 × Gs (Gs: static elastic modulus (MPa))
Gs = 1.639 × σ25 (σ25: 25% low elongation stress (MPa))
A measurement result is shown to Tables 1-3 with the process composition of surface treatment calcium carbonate.

  As is apparent from the results shown in Tables 1, 2 and 3, the rubber compositions of Examples 1 to 7 in which calcium carbonate was blended with quaternary ammonium salt compound and surface-treated calcium carbonate surface-treated with resin acid. Indicates a low dynamic magnification. Therefore, it can be seen that the rubber compositions of Examples 1 to 7 are excellent in vibration-proof properties.

  Example 2 using surface-treated calcium carbonate surface-treated with a combination of quaternary ammonium salt compound and resin acid, and surface-treated calcium carbonate surface-treated with a combination of quaternary ammonium salt compound and fatty acid were used. Comparing with Comparative Example 1, it can be seen that the dynamic magnification of Example 2 is 0.1 or more lower than that of Comparative Example 1, and the vibration isolation characteristics are dramatically improved.

  Similarly, from a comparison between Example 4 and Comparative Example 5 and a comparison between Example 5 and Comparative Example 7, by using a resin acid as a surface treatment agent to be treated in combination with a quaternary ammonium salt compound, As compared with the case of using a fatty acid, the vibration isolation characteristics can be dramatically improved. Thus, according to the present invention, an effect that cannot be predicted from the disclosure of Patent Document 1 can be obtained.

Claims (3)

  The surface of calcium carbonate having an average primary particle size of 0.01 to 10.0 μm is surface-treated with a quaternary ammonium salt compound and resin acids, and the surface treatment amount of the quaternary ammonium salt compound is 100 parts by mass of calcium carbonate. The surface-treated calcium carbonate, which is 0.05 to 1 part by mass.   The surface-treated calcium carbonate according to claim 1, wherein the surface treatment amount of the resin acid is 0.1 to 8 parts by mass with respect to 100 parts by mass of calcium carbonate.   5 to 200 parts by mass of the surface-treated calcium carbonate according to claim 1 or 2 with respect to 100 parts by mass of rubber.