CA2241619A1 - Kaolin clay in silica tread compounds - Google Patents
Kaolin clay in silica tread compounds Download PDFInfo
- Publication number
- CA2241619A1 CA2241619A1 CA002241619A CA2241619A CA2241619A1 CA 2241619 A1 CA2241619 A1 CA 2241619A1 CA 002241619 A CA002241619 A CA 002241619A CA 2241619 A CA2241619 A CA 2241619A CA 2241619 A1 CA2241619 A1 CA 2241619A1
- Authority
- CA
- Canada
- Prior art keywords
- parts
- silica
- kaolin clay
- tread
- sbr
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims abstract description 106
- 239000000377 silicon dioxide Substances 0.000 title claims abstract description 53
- 239000004927 clay Substances 0.000 title claims abstract description 31
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 239000005995 Aluminium silicate Substances 0.000 title claims abstract description 24
- 235000012211 aluminium silicate Nutrition 0.000 title claims abstract description 24
- 150000001875 compounds Chemical class 0.000 title claims abstract description 17
- 239000000203 mixture Substances 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 18
- 229920001971 elastomer Polymers 0.000 claims abstract description 15
- 239000006229 carbon black Substances 0.000 claims abstract description 11
- 239000006087 Silane Coupling Agent Substances 0.000 claims abstract description 8
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 12
- 239000005060 rubber Substances 0.000 claims description 12
- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 10
- 239000007822 coupling agent Substances 0.000 claims description 9
- 244000043261 Hevea brasiliensis Species 0.000 claims description 8
- 229920003052 natural elastomer Polymers 0.000 claims description 8
- 229920001194 natural rubber Polymers 0.000 claims description 8
- 239000005062 Polybutadiene Substances 0.000 claims description 5
- 229920002857 polybutadiene Polymers 0.000 claims description 5
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 claims description 3
- 229920002554 vinyl polymer Polymers 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 abstract description 4
- 239000000806 elastomer Substances 0.000 abstract description 3
- 238000013329 compounding Methods 0.000 abstract description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 7
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 4
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 238000005096 rolling process Methods 0.000 description 4
- 229910000077 silane Inorganic materials 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 235000021355 Stearic acid Nutrition 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 2
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 2
- 239000008117 stearic acid Substances 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- 229920005601 base polymer Polymers 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000010058 rubber compounding Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- VTHOKNTVYKTUPI-UHFFFAOYSA-N triethoxy-[3-(3-triethoxysilylpropyltetrasulfanyl)propyl]silane Chemical compound CCO[Si](OCC)(OCC)CCCSSSSCCC[Si](OCC)(OCC)OCC VTHOKNTVYKTUPI-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/36—Silica
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
- B60C1/0016—Compositions of the tread
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/346—Clay
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/54—Silicon-containing compounds
- C08K5/5406—Silicon-containing compounds containing elements other than oxygen or nitrogen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S152/00—Resilient tires and wheels
- Y10S152/905—Tread composition
Abstract
The invention relates to a method for decreasing dynamic modulus without decreasing hardness in silica tread compounds in tires made in accordance with this method. The tread composition comprises an elastomer including a performance-enhancing package comprising silica, carbon black and a silica replacement. The replacement replaces up to about 40 percent by weight of the silica and yet maintains one or more selected performance properties as if the performance enhancement package were pure carbon black and silica. The replacement is kaolin clay present in conjunction with a silane coupling agent. In the method of the present invention kaolin clay is used as a replacement for about 5 to about 20 parts, by weight, of silica in the compounding of silica tread compounds.
Description
K~OLIN CLAY IN SILICA TREAD COMPOUNDS
TECHNICAL FIEL~
The invention relates to a method for decreasing dynamic modulus without decreasing hardness so as to improve ride quality while maintaining wet and dry handling characteristics, in silica tread compounds and tires generally for passenger vehicles made in accordance with this method. The present 5invention also relates to the composition made by this method. This result is achieved by using a kaolin clay as a partial replacement for silica in a performance-enhancing system added to the silica tread compounds.
BACKGROUND ART
10The object of the present invention is to provide a tread rubber composition having a base tread rubber combined with a system or package of performance-enhancing agents comprising silica, coupling agent, carbon black, and kaolin clay.
A wide variety of factors are taken into consideration in the art 15and science of formulating tire tread compositions. For example, the tires areformulated to achieve specific wet and dry handling characteristics, provide traction under snowy conditions, resist abrasion, and provide a quiet, comfort-able ride while achieving suitable tire wear. Performance-enhancing agents are added to the base elastomer to help achieve the desired characteristics.
20Sometimes combinations of such agents can act synergistically and can functionunexpectedly in collaboration.
It has been customary in the past to incorporate silica in tire tread compositions as a filler and also to enhance the performance characteristics of the tire, such as low rolling resistance, while improving adherence to wet and 25snow-covered ground, improving wear and aging properties while reducing noise.While numerous patents relate to the state of the art with respect to the base polymer for tire treads, U.S. Patent No. 5,227,425, to }~auline, relates more specifically to all-season, high-performance tires utilizing a specific type of silica to improve performance characteristics of the tires.
U.S. Patent No. 4,522,970, to Scriver et al., is an example of a patent relating to sulfur cured, rubber tread compositions formulated to meet certain defined performance characteristics.
The present invention relates to a method of achieving unexpected stress/strain characteristics in tread compositions so as to reduce the low strain modulus of a tire tread without reducing the hardness or high strain modulus to the same degree. This contrasts with the customary relationship between these characteristics. More specifically, the compositions maintain wet and dry handling, abrasion resistance, and snow traction of a silica tread compound while improving ride comfort and impact damping.
The present invention is particularly suitable for tire treads intended for passenger cars, all-terrain vehicles, pick-up trucks, and motorcycles.
The above objects are met by the partial replacement of silica with a kaolin clay in conjunction with a silane coupling agent as a performance-enhancing system in an elastorneric tread composition.
In the method of the present invention low strain modulus is reduced without reducing the hardness or high strain modulus to the same - degree in silica tread compounds by replacing from about 20 to about 40~o of the total silica with an equal amount of kaolin clay to result in a performance-enhancing package of about 5 to 20 parts by weight of clay, about 20-50 parts by weight of a high structure, high surface area silica which preferably includes a silane coupling agent, and about 0-60 parts of highly structured, tread-grade carbon black, all per 100 parts of base elastomeric composition.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, this performance-enhancing system can be used with various tread compositions. Such tread compositions are primarily based upon a mixture of natural rubber, styrene butadiene rubber, and butadiene rubber and/or blends thereof.
The kaolin clay of the present invention is also known as hydrated aluminum silicate and can be air-floated or water-washed (having a median particle size of from about 0.2 microns). The kaolin clay is substituted on a 1:1 weight basis for from about 20 to about 40 percent of the silica. More broadly, the kaolin clay may be provided in a weight ratio of from 0.1:1 to 1:1 parts by weight, and preferably 0.2:1 to 0.4:1 part by weight, of clay to silica.
The kaolin clay is enhanced by the presence of a silane coupling agent which is for example Bis(3-triethoxysilylpropyl)-tetrasulfane (such as sold under the name Si69~' from Degussa). The coupling agent may be reacted in situ with the clay (as well as the silica), although alternatively clay pretreated with the coupling agent may be used. The coupling agent is provided for the clay at the same ratio that it is provide for the silica, i.e., from about 6 to 12 weight percent of the silica.
Silica is also used in the high-performance package and it includes high-structure, high surface area silica, i.e., having a nitrogen surface area of from about 190 to about 220 m2/g, for a total of not more than about 50 parts;
i.e. from about 20 to about 50 parts; preferably not more than about 45 parts;
i.e. from about 25 to about 45 parts; and most preferably not more than about 40 parts; i.e. from about 30 to about 40 parts of silica; all parts based on 100parts of base rubber.
Carbon black is also used: preferably high structured, tread-grade carbon black at from 0-60; preferably 15-45; and most preferably 35 to 40 parts,all parts based on 100 parts of base rubber.
In accordance with the present invention specific mixing sequences follow in which the first step rubber and silica are mixed with the carbon blackand the clay at a temperature of from about 300~F to about 390~F and preferably about 320~F to about 380~F, i.e., a relatively high temperature. In asecond stage, coupling agent is added and the temperature is held between about 260~F and about 300~F for mixing and to react the coupling agent with the silica and the kaolin clay, which temperature is held below the cross-linking initiation temperature. In an optional third stage, the compound is re-melted at a temperature of from about 220~F to about 260~F to improve the processing.
In the final stage, curatives are introduced and mixing continues at a tempera-ture of about 180~F to about 220~F. The mixing occurs in an internal mixer such as a Banbury6' or Intermix~.
EXAMPLES
In accordance with this invention, two rubber tread compositions were compounded having the formulas listed in Table I. Specifically, the rubber and silica were mixed at the percentages listed in the control and with kaolin clay in the parts listed under Formula A at a temperature of about 340~F. In a second stage, the silane coupling agent was added and the temperature was held at about 290~ to react the coupling agent respectively with the silica or the kaolin clay. The oil and carbon black were added in the first stage. In the final stage, state-of-the-art sulphur cure system was used at a typical ratio at a temperature of about 190~F. The parts are listed in the Table so that the pertinent ingredients are based on 100 parts of rubber as is known to those skilled in the art of rubber compounding. The additional components above 100 are components which are not rubber, such as extenders, fillers, and the like.
In a second example, a different tread composition was formulated in accordance with Table II corresponding to the process described for Example 1. Once again, kaolin clay was added to Sample B and omitted from the control. The amount of the silane added in both systems was the same relative to the amount of silica; however, since there was less silica in the samples, the cumulative amount of silane was lower. It is believed that this lower amount is still effective since the clay has smaller surface area than the amount of silica which it replaces, i.e. enough residual silane coupling agent is present to alsocouple the kaolin clay in the system.
After compounding, appropriate test specimens were formed of the compositions and physical properties were tested for Examples 1 and 2. With respect to the test, the low strain modulus was considered herein to be 0 to 25 percent deflection, while the high strain modulus is 100 percent or greater deflection. The results of these tests are set forth in Tables III and IV. Test equipment and methods are listed in Table V. The test results for the controls were normalized to 100 and the test data normalized to show improvement as a higher number relative to the control. The Tables indicate improvement in dynamic modulus, tangent delta, 5 percent modulus, while maintaining a relatively similar, or better 300 percent modulus and Shore-A Durometer hardness. An unexpected rolling loss improvement was demonstrated which results in a projected fuel economy for the tire vehicle system. Moreover, therewas some improvement in snow and ice traction demonstrated at the dynamic modulus at -20~C for Example 1.
TABLE I
Solution SBR *90.75 *90.-75 High Styrene High-Cis BR 25.0 25.0 N110 Carbon Black 41 41 Silica 40 30 Kaolin Clay --- 10 Silane 8 6 Oil 25.5 25.5 Zinc Oxide 1.7 1.7 Stearic Acid Wax 1.5 1.5 Antiozonant 0.95 0.95 * The SBR ingredient is a total weight including 15.75 weight parts of extended oil, so that the amount of SBR was 75 parts.
TABLE II
FORMULA 2 CONTROL EX~MPLE
Solution SBR * 27.5 * 27.5 Medium Styrene Solution SBR 45 55 High Vinyl Natural Rubber 35 25 Carbon Black 35 35 Silica 35 25 Kaolin Clay --- 10 Silane 7 5 Oil 7.5 7.5 Zinc Oxide 3 3 Stearic Acid Wax 1.5 1.5 Antiozonant 0.95 0.95 * The SBR ingredient is a total weight including 7.5 parts of extended oil so that the amount of this SBR
was 20 parts.
TABLE III
ZR277 Data - Norm~1i7e~1 Physical Property Control Test Predictor Dynamic Modulus @25~C 100 139 Ride comfort Tangent Delta @ 50~C 100 109 Rolling loss 5% Modulus 100 120 Ride comfort 300% Modulus 100 101 Handling Shore "A" Durometer 100 96 Handling Hardness Dynamic Modulus at -20~ 100 115 Snow/Ice Traction TABLE IV
ZR827 Data - Normalized Physical Property Control Test Predictor Dynamic Modulus (~?25~C 100 130 Ride comfort Tangent Delta @ 50~C 100 118 Rolling loss 5% Modulus 100 115 Ride comfort 300~o Modulus 100 94 Handling Shore "A" Durometer 100 96 Handling Hardness Dynamic Modulus at 100 116 Snow/Ice Traction -20~C
TABLE V
Test Equipment & Methods DYNAMIC MODULUS @ 25~C
TANGENT DELTA @ 50~C
. Measured on MTS Elastomer Test System Model 830 . 5% Deflection @ 10 Hz 5% MODULUS
. Measured on Instron Model 4465 300% MODULUS
. Measured on Instron Model 4400 DUROMETER
. In accordance with ASTM D2240-95 DYNAMIC MODULUS (~? -20~C
. Rheometrics Dynamic Analyzer Model RDA II
. 0.1~o Strain @ 10 Hz While in accordance with the patent statutes the best mode and preferred embodiment has been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
TECHNICAL FIEL~
The invention relates to a method for decreasing dynamic modulus without decreasing hardness so as to improve ride quality while maintaining wet and dry handling characteristics, in silica tread compounds and tires generally for passenger vehicles made in accordance with this method. The present 5invention also relates to the composition made by this method. This result is achieved by using a kaolin clay as a partial replacement for silica in a performance-enhancing system added to the silica tread compounds.
BACKGROUND ART
10The object of the present invention is to provide a tread rubber composition having a base tread rubber combined with a system or package of performance-enhancing agents comprising silica, coupling agent, carbon black, and kaolin clay.
A wide variety of factors are taken into consideration in the art 15and science of formulating tire tread compositions. For example, the tires areformulated to achieve specific wet and dry handling characteristics, provide traction under snowy conditions, resist abrasion, and provide a quiet, comfort-able ride while achieving suitable tire wear. Performance-enhancing agents are added to the base elastomer to help achieve the desired characteristics.
20Sometimes combinations of such agents can act synergistically and can functionunexpectedly in collaboration.
It has been customary in the past to incorporate silica in tire tread compositions as a filler and also to enhance the performance characteristics of the tire, such as low rolling resistance, while improving adherence to wet and 25snow-covered ground, improving wear and aging properties while reducing noise.While numerous patents relate to the state of the art with respect to the base polymer for tire treads, U.S. Patent No. 5,227,425, to }~auline, relates more specifically to all-season, high-performance tires utilizing a specific type of silica to improve performance characteristics of the tires.
U.S. Patent No. 4,522,970, to Scriver et al., is an example of a patent relating to sulfur cured, rubber tread compositions formulated to meet certain defined performance characteristics.
The present invention relates to a method of achieving unexpected stress/strain characteristics in tread compositions so as to reduce the low strain modulus of a tire tread without reducing the hardness or high strain modulus to the same degree. This contrasts with the customary relationship between these characteristics. More specifically, the compositions maintain wet and dry handling, abrasion resistance, and snow traction of a silica tread compound while improving ride comfort and impact damping.
The present invention is particularly suitable for tire treads intended for passenger cars, all-terrain vehicles, pick-up trucks, and motorcycles.
The above objects are met by the partial replacement of silica with a kaolin clay in conjunction with a silane coupling agent as a performance-enhancing system in an elastorneric tread composition.
In the method of the present invention low strain modulus is reduced without reducing the hardness or high strain modulus to the same - degree in silica tread compounds by replacing from about 20 to about 40~o of the total silica with an equal amount of kaolin clay to result in a performance-enhancing package of about 5 to 20 parts by weight of clay, about 20-50 parts by weight of a high structure, high surface area silica which preferably includes a silane coupling agent, and about 0-60 parts of highly structured, tread-grade carbon black, all per 100 parts of base elastomeric composition.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, this performance-enhancing system can be used with various tread compositions. Such tread compositions are primarily based upon a mixture of natural rubber, styrene butadiene rubber, and butadiene rubber and/or blends thereof.
The kaolin clay of the present invention is also known as hydrated aluminum silicate and can be air-floated or water-washed (having a median particle size of from about 0.2 microns). The kaolin clay is substituted on a 1:1 weight basis for from about 20 to about 40 percent of the silica. More broadly, the kaolin clay may be provided in a weight ratio of from 0.1:1 to 1:1 parts by weight, and preferably 0.2:1 to 0.4:1 part by weight, of clay to silica.
The kaolin clay is enhanced by the presence of a silane coupling agent which is for example Bis(3-triethoxysilylpropyl)-tetrasulfane (such as sold under the name Si69~' from Degussa). The coupling agent may be reacted in situ with the clay (as well as the silica), although alternatively clay pretreated with the coupling agent may be used. The coupling agent is provided for the clay at the same ratio that it is provide for the silica, i.e., from about 6 to 12 weight percent of the silica.
Silica is also used in the high-performance package and it includes high-structure, high surface area silica, i.e., having a nitrogen surface area of from about 190 to about 220 m2/g, for a total of not more than about 50 parts;
i.e. from about 20 to about 50 parts; preferably not more than about 45 parts;
i.e. from about 25 to about 45 parts; and most preferably not more than about 40 parts; i.e. from about 30 to about 40 parts of silica; all parts based on 100parts of base rubber.
Carbon black is also used: preferably high structured, tread-grade carbon black at from 0-60; preferably 15-45; and most preferably 35 to 40 parts,all parts based on 100 parts of base rubber.
In accordance with the present invention specific mixing sequences follow in which the first step rubber and silica are mixed with the carbon blackand the clay at a temperature of from about 300~F to about 390~F and preferably about 320~F to about 380~F, i.e., a relatively high temperature. In asecond stage, coupling agent is added and the temperature is held between about 260~F and about 300~F for mixing and to react the coupling agent with the silica and the kaolin clay, which temperature is held below the cross-linking initiation temperature. In an optional third stage, the compound is re-melted at a temperature of from about 220~F to about 260~F to improve the processing.
In the final stage, curatives are introduced and mixing continues at a tempera-ture of about 180~F to about 220~F. The mixing occurs in an internal mixer such as a Banbury6' or Intermix~.
EXAMPLES
In accordance with this invention, two rubber tread compositions were compounded having the formulas listed in Table I. Specifically, the rubber and silica were mixed at the percentages listed in the control and with kaolin clay in the parts listed under Formula A at a temperature of about 340~F. In a second stage, the silane coupling agent was added and the temperature was held at about 290~ to react the coupling agent respectively with the silica or the kaolin clay. The oil and carbon black were added in the first stage. In the final stage, state-of-the-art sulphur cure system was used at a typical ratio at a temperature of about 190~F. The parts are listed in the Table so that the pertinent ingredients are based on 100 parts of rubber as is known to those skilled in the art of rubber compounding. The additional components above 100 are components which are not rubber, such as extenders, fillers, and the like.
In a second example, a different tread composition was formulated in accordance with Table II corresponding to the process described for Example 1. Once again, kaolin clay was added to Sample B and omitted from the control. The amount of the silane added in both systems was the same relative to the amount of silica; however, since there was less silica in the samples, the cumulative amount of silane was lower. It is believed that this lower amount is still effective since the clay has smaller surface area than the amount of silica which it replaces, i.e. enough residual silane coupling agent is present to alsocouple the kaolin clay in the system.
After compounding, appropriate test specimens were formed of the compositions and physical properties were tested for Examples 1 and 2. With respect to the test, the low strain modulus was considered herein to be 0 to 25 percent deflection, while the high strain modulus is 100 percent or greater deflection. The results of these tests are set forth in Tables III and IV. Test equipment and methods are listed in Table V. The test results for the controls were normalized to 100 and the test data normalized to show improvement as a higher number relative to the control. The Tables indicate improvement in dynamic modulus, tangent delta, 5 percent modulus, while maintaining a relatively similar, or better 300 percent modulus and Shore-A Durometer hardness. An unexpected rolling loss improvement was demonstrated which results in a projected fuel economy for the tire vehicle system. Moreover, therewas some improvement in snow and ice traction demonstrated at the dynamic modulus at -20~C for Example 1.
TABLE I
Solution SBR *90.75 *90.-75 High Styrene High-Cis BR 25.0 25.0 N110 Carbon Black 41 41 Silica 40 30 Kaolin Clay --- 10 Silane 8 6 Oil 25.5 25.5 Zinc Oxide 1.7 1.7 Stearic Acid Wax 1.5 1.5 Antiozonant 0.95 0.95 * The SBR ingredient is a total weight including 15.75 weight parts of extended oil, so that the amount of SBR was 75 parts.
TABLE II
FORMULA 2 CONTROL EX~MPLE
Solution SBR * 27.5 * 27.5 Medium Styrene Solution SBR 45 55 High Vinyl Natural Rubber 35 25 Carbon Black 35 35 Silica 35 25 Kaolin Clay --- 10 Silane 7 5 Oil 7.5 7.5 Zinc Oxide 3 3 Stearic Acid Wax 1.5 1.5 Antiozonant 0.95 0.95 * The SBR ingredient is a total weight including 7.5 parts of extended oil so that the amount of this SBR
was 20 parts.
TABLE III
ZR277 Data - Norm~1i7e~1 Physical Property Control Test Predictor Dynamic Modulus @25~C 100 139 Ride comfort Tangent Delta @ 50~C 100 109 Rolling loss 5% Modulus 100 120 Ride comfort 300% Modulus 100 101 Handling Shore "A" Durometer 100 96 Handling Hardness Dynamic Modulus at -20~ 100 115 Snow/Ice Traction TABLE IV
ZR827 Data - Normalized Physical Property Control Test Predictor Dynamic Modulus (~?25~C 100 130 Ride comfort Tangent Delta @ 50~C 100 118 Rolling loss 5% Modulus 100 115 Ride comfort 300~o Modulus 100 94 Handling Shore "A" Durometer 100 96 Handling Hardness Dynamic Modulus at 100 116 Snow/Ice Traction -20~C
TABLE V
Test Equipment & Methods DYNAMIC MODULUS @ 25~C
TANGENT DELTA @ 50~C
. Measured on MTS Elastomer Test System Model 830 . 5% Deflection @ 10 Hz 5% MODULUS
. Measured on Instron Model 4465 300% MODULUS
. Measured on Instron Model 4400 DUROMETER
. In accordance with ASTM D2240-95 DYNAMIC MODULUS (~? -20~C
. Rheometrics Dynamic Analyzer Model RDA II
. 0.1~o Strain @ 10 Hz While in accordance with the patent statutes the best mode and preferred embodiment has been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
Claims (14)
1. A method for reducing low strain modulus without reducing hardness and high strain modulus to the same extent of a silica tread compound comprising the steps of preparing a base tread composition and adding a performance-enhancing system comprising 0 to about 60 parts of high-structured, tread-grade carbon black, about 20 to 50 parts of high-structure, high surface area silica, and about 5 to about 20 parts of kaolin clay and silane coupling agent, the coupling agent being from about 6 to about 12 weight percent of the kaolin clay and silica, all parts being based on 100 parts of base tread composition.
2. The method of Claim 1, wherein the kaolin clay is present at a weight ratio of from about 0.1 to about 1 part per part of silica.
3. The method of Claim 2, wherein the kaolin clay is present at a weight ratio of from about 0.2 to about 0.5 part per part of silica.
4. The method of Claim 1, wherein said base tread composition comprises a blend of one or more of polybutadiene, SBR, and natural rubber.
5. The method of Claim 4, comprising from 0 to about 50 parts of polybutadiene, about 5 to about 100 parts SBR, and 0 to about 40 parts of natural rubber.
6. The method of Claim 5, comprising from about 10 to about 50 parts of high cis-butadiene and from about 50 to about 90 parts of high styrene SBR.
7. The method of Claim 1, comprising about 10 to about 50 parts of medium styrene SBR, from about 15 to about 60 parts of high vinyl SBR, and from about 5 to about 40 parts of natural rubber.
8. A silica tread compound comprising a base rubber composition and a performance-enhancing system comprising 0 to about 60 parts of high-structured, tread-grade, carbon black, about 20 to about 50 parts of high-structure, low-particle-size silica, and about 5 to about 20 parts of kaolin clay and silane coupling agent, the coupling agent being from about 6 to about 12 weight percent of the kaolin clay and silica, all parts being based on 100 partsof base rubber composition.
9. A silica tread compound according to Claim 8, wherein the kaolin clay is present at a weight ratio of from about 0.1 to about 1 part per part of silica.
10. A silica tread compound according to Claim 9, wherein the kaolin clay is present at a weight ratio of from about 0.2 to about 0.5 part perpart of silica.
11. A silica tread compound according to Claim 8, wherein said base tread composition comprises a blend of one or more of polybutadiene, SBR, and natural rubber.
12. A silica tread compound according to Claim 11, comprising from 0 to about 50 parts of polybutadiene, about 5 to about 100 parts SBR, and 0 to about 40 parts of natural rubber.
13. A silica tread compound according to Claim 11, comprising from about 10 to about 50 parts of high cis-butadiene and from about 50 to about 90 parts of high styrene SBR.
14. A silica tread compound according to Claim 11, comprising about 10 to about 50 parts of medium styrene SBR, from about 15 to about 60 parts of high vinyl SBR, and from about 5 to about 40 parts of natural rubber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/912,964 | 1997-07-30 | ||
| US08/912,964 US6080809A (en) | 1997-07-30 | 1997-07-30 | Kaolin clay in silica tread compounds technical field |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2241619A1 true CA2241619A1 (en) | 1999-01-30 |
Family
ID=25432770
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002241619A Abandoned CA2241619A1 (en) | 1997-07-30 | 1998-06-26 | Kaolin clay in silica tread compounds |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US6080809A (en) |
| EP (1) | EP0894819A1 (en) |
| JP (1) | JPH11228747A (en) |
| CA (1) | CA2241619A1 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6384117B1 (en) | 1997-07-11 | 2002-05-07 | Bridgestone Corporation | Processability of silica-filled rubber stocks |
| US6221943B1 (en) | 1997-07-11 | 2001-04-24 | Bridgestone Corporation | Processability of silica-filled rubber stocks |
| US6525118B2 (en) | 1997-07-11 | 2003-02-25 | Bridgestone Corporation | Processability of silica-filled rubber stocks with reduced hysteresis |
| WO1999006197A1 (en) * | 1997-08-01 | 1999-02-11 | Sedepro | Continuous rubber kneader |
| DE10014664A1 (en) * | 2000-03-24 | 2001-09-27 | Sued Chemie Ag | Rubber mixture crosslinkable with sulfur useful for manufacture of automobile tires and vibration dampers, contains an acid activated silicate layer and reduces the roll resistance and thus the petrol consumption of automobile tires |
| JP5236138B2 (en) * | 2000-07-28 | 2013-07-17 | 住友ゴム工業株式会社 | Rubber composition for tire tread and pneumatic tire using the same |
| DE60116716T2 (en) * | 2000-07-28 | 2006-08-10 | Sumitomo Rubber Industries Ltd., Kobe | Katschuk composition for tire treads and tires with tread therefrom |
| US6608145B1 (en) | 2000-10-13 | 2003-08-19 | Bridgestone Corporation | Silica-reinforced rubber compounded with an organosilane tetrasulfide silica coupling agent at high mixing temperature |
| US6433065B1 (en) | 2000-10-13 | 2002-08-13 | Bridgestone Corporation | Silica-reinforced rubber compounded with mercaptosilanes and alkyl alkoxysilanes |
| KR100426955B1 (en) * | 2001-06-22 | 2004-04-13 | 금호타이어 주식회사 | Tread rubber composition for tire |
| WO2003008491A1 (en) * | 2001-07-18 | 2003-01-30 | Imerys Minerals Limited | Clay mineral products and their use in rubber compositions |
| RU2323230C2 (en) | 2002-07-09 | 2008-04-27 | Моментив Перформанс Матириалз Инк. | Silica-rubber mixes with improved strength properties |
| GB0328236D0 (en) * | 2003-12-05 | 2004-01-07 | Dow Corning | Method of making kaolin containing silicone rubber compositions |
| JP2007534833A (en) * | 2004-04-27 | 2007-11-29 | 株式会社ブリヂストン | Method for producing tire composition having improved silica reinforcement performance |
| CN101755003B (en) * | 2007-07-20 | 2013-03-06 | 横滨橡胶株式会社 | Rubber composition |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4522970A (en) * | 1984-06-25 | 1985-06-11 | The Goodyear Tire & Rubber Company | Tire with tread rubber containing medium vinyl polybutadiene with clay and carbon black |
| JP2865577B2 (en) * | 1993-11-26 | 1999-03-08 | 住友ゴム工業株式会社 | Tread rubber composition |
| EP0697432B1 (en) * | 1994-08-19 | 2003-10-15 | Bridgestone Corporation | Rubber composition for tire treads |
| US5580919A (en) * | 1995-03-14 | 1996-12-03 | The Goodyear Tire & Rubber Company | Silica reinforced rubber composition and use in tires |
| US5672639A (en) * | 1996-03-12 | 1997-09-30 | The Goodyear Tire & Rubber Company | Starch composite reinforced rubber composition and tire with at least one component thereof |
-
1997
- 1997-07-30 US US08/912,964 patent/US6080809A/en not_active Expired - Lifetime
-
1998
- 1998-06-26 CA CA002241619A patent/CA2241619A1/en not_active Abandoned
- 1998-07-09 EP EP98112729A patent/EP0894819A1/en not_active Withdrawn
- 1998-07-24 JP JP10225250A patent/JPH11228747A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11228747A (en) | 1999-08-24 |
| EP0894819A1 (en) | 1999-02-03 |
| US6080809A (en) | 2000-06-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |