CA2122347A1 - Tire and belt compositions - Google Patents
Tire and belt compositionsInfo
- Publication number
- CA2122347A1 CA2122347A1 CA002122347A CA2122347A CA2122347A1 CA 2122347 A1 CA2122347 A1 CA 2122347A1 CA 002122347 A CA002122347 A CA 002122347A CA 2122347 A CA2122347 A CA 2122347A CA 2122347 A1 CA2122347 A1 CA 2122347A1
- Authority
- CA
- Canada
- Prior art keywords
- phr
- rubber
- mixture
- weight percent
- tire
- 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
Classifications
-
- 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
-
- 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
-
- 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
- B60C1/0025—Compositions of the sidewalls
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L7/00—Compositions of natural rubber
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L9/06—Copolymers with styrene
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The present invention relates to a tire wherein at least one of the tread, steel-cord skim stock, sidewall and carcass portions contains a rubber composition formed by curing a blend of a.
natural rubber, polyisoprene or a mixture thereof, b. butadiene rubber, styrene-butadiene rubber or a mixture thereof, c. carbon black, d. activator, e. zinc oxide, f. sulfur or a sulfur donor, and g.
curing accelerator, characterized in that said rubber composition has a heat buildup of 20-35 ·C. These tires exhibit one or more improvements in a wide variety of properties. The present invention relates also to a belt which contains such a rubber composition, characterized in that said rubber composition has a heat buildup of 10-25 ·C. These belts exhibit also one or more improvements in a variety of properties.
natural rubber, polyisoprene or a mixture thereof, b. butadiene rubber, styrene-butadiene rubber or a mixture thereof, c. carbon black, d. activator, e. zinc oxide, f. sulfur or a sulfur donor, and g.
curing accelerator, characterized in that said rubber composition has a heat buildup of 20-35 ·C. These tires exhibit one or more improvements in a wide variety of properties. The present invention relates also to a belt which contains such a rubber composition, characterized in that said rubber composition has a heat buildup of 10-25 ·C. These belts exhibit also one or more improvements in a variety of properties.
Description
WO 93/09178 PCI'/EP92/01030 . . 1 21223~7 Tire and Belt Compositions The present invention relates to tires and belts which have improved properties as compared to standard tire and belt compositions. The inventors have found that tire and belt compositions having a reduced heat buildup exhibit improved properties9 especially when subjected to environments which lead to ageing of the rubber compositions.
The importance of heat buildup is recognized in the article, "Carbon Black in NR/BR Blends for Truck Tires,'l Rubber Chemistr~ and Technology, Vol. 58, pp. 350-36B (1985), wherein it is stated that treadwear, heat buildup, resistance to cutting and chipping and fuel economy are important to heavy duty truck tire performance.
Accordingly, there is a need in the art for tire and belt products which exhibit a low heat buildup. since such products exhibit a better performance as well as having, in many`cases, a longer service life.
Many attempts have been made to produce products with a low heat buildup. ~or example~ European Patent application 0 314 271 discloses the use of an improved processing aid to improve handling, durability and rolling resistance of tires, as well as reducing heat buildup.
European Patent application 0 451 603 relates to the use of an anionic polymerization initiator for curing elastomers to improve their hysteresis. ~mproved hysteresis leads to tires having a lower rolling resistance. One aspect of hysteresis is heat buildup.
PCT patent application WO 91/05821 discloses a tire sidewall composition comprising a particular polymer which leads to sidewalls having a desirable reduced internal heat buildup and improved adhesion to adjacent rubber carcass and tread portions of the tire.
~3UBSTITUTE StlEET
WO 93/09178 PCI`/EP92/01030 21223~7 Finally, the publication, "Natural Rubber Compounds for Truck Tires,"
NR Technology, Vol. 16, Part 1 (1985) suggests the use of additional stearic acid activator in order to reduce the heat generation, among other properties, in truck tires.
However, all of these solutions fall short of the goal of providing tires and belts with longer service life, better ageing characteristics, lower rolling resistance and better fuel economy.
The present inventors have surprisingly found that tire and belt compositions having a particular heat buildup exhibit several improved properties, particularly when the tires and belts are subjected to service conditions.
More specifically, the present invention relates, in one aspect to a tire wherein at least one of the tread, steel-cord skim stock, sidewall and carcass portions contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator, . . .
characterized in that said rubber composition has a heat buildup of 20-35C. These tires exhibit one or more improvements in a wide variety of properties such as abrasion resistance, rolling resistance, ageing resistance, adhesion to steel, cutting and chipping resistance and service life.
SUBSTITUTE SHEET
212~347 In a second aspect, the present invention relates to a belt which contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber~ styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 10-25C. These belts exhibit one or more improv~ments in a variety of properties including tear strength, tensile strength, service life and ageing resistance.
The low heat buildup rubber compositions of the present invention can be used in tire treads for truck tires and off-the-road tires, in particular, for sidewalls, for tire carcasses and for steel-cord skim stocks. In belts, the rubber compositions of the present invention are particularly useful for conveyor belts and V-belts which are subjected to high loading and abrasion in service.
2g A typical truck tire tread composition in accordance with the present invention comprises the cured product of a blend containing:
50-100 we-ight percent of natural rubber~ polyisoprene or a mixture 30 thereof, 0 50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 45-65 phr, based on the total rubber content, of carbon black, 1.0-3.0 phr of activator, ~3UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 2122~47 1.0~10.0 phr of zinc oxide, 1.0-5.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator.
Of course, these truck tire treads may contain other conventional additives such as 0-20 phr silica, 2-10 phr tackifier, 5-50 phr of processing oil, 1-5 phr waxes, 1-5 phr antioxidant and 1-5 phr antiozonants.
Important properties for truck tire treads include abrasion resistance, rolling resistance, resistance. to cracking, thermal and oxidative stability and durability.
A typical steel-cord skim stock composition in accordance with the present invention is the cured product of a blend comprising:
85-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-15 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 45-65 phr, based on the total rubber content, of carbon black having an average particle size of 10-30 nm, 0.5-2.0 phr of activator, 1.0-10.0 phr of zinc oxide, 4.0-8.0 phr of sulfur or a sulfur donor, and 0.5-1.5 phr of curing accelerator.
These steel-cord skim stocks may also contain 0-20 phr silica, 0-2.0 phr of a cobalt salt and 1-3 phr of antidegradants. Adhesion to steel is an important property for this portion of the tire.
A typical carcass portion of a tire in accordance with the present invention is the cured product of a blend comprising:
~3UBSTITUTE SHEET
WO 93/09178 P~/EP9~/01030 21223~
50-80 weight percent of natural rubber, polyisopr~ne or a mixture thereof, 20-50 weight percent of butadiene rubber~ styrene-butadiene rubber or a mixture thereof, 20-50 phr, based on the total rubber content, of carbon black having an average particle size of 45 70 nm, 1.0-3.0 phr of activator, 1.0-10.0 phr of zinc oxide, 2.0-5.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator.
These carcass portions may a~so contain 1-3 phr antioxidant and 2-8 phr processing oil, if desired. Important properties fcr the carcass portion are the thermal resistance and the rebound resilience.
A typical sidewall portion of a tire in accordance with the present invention is the cured product of a blend comprising:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 40-60 phr, based on the total rubber content, of carbon btack having an average particle size of 20-70 nm, 1.0-4.0 phr of activator, 2.0-6.0 phr of zinc oxide, 1.0-3.0 phr of sulfur or a sulfur donor, and 0.5-1.5 phr of curing accelerator.
These sidewall portions may also contain from 5-10 phr of whitening.
Important properties for the sidewall portion are fatigue resistance, ozone resistance, cutting and chipping resistance and reversion resistance.
~UBSTITUTE SHEET
2~223~
A typical off-the-road tire tread in accordance with the present invention is the cured product of a blend which comprises:
80-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-20 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-50 phr, based on the total rubber content, of carbon black having an average particle size of 10-30 nm, 1.0-3.0 phr of activator, 1.0-10.0 phr of zinc oxide, 10-25 phr of silica having a surface area of 100-200 m2/g, 1.0-2.0 phr of sulfur or a sulfur donor, and 1.0-2.0 phr of curing accelerator.
Off-the-road tîre treads may also include 5-50 phr of processing oil, 0-5 phr of resin, 0-2 phr wax, 1-4 phr antio~onants and 0.5-2.0 phr antioxidants. Important properties for off-the-road tire treads are tread wear, cutting and chipping resistance and hysteresis.
A typical conveyor belt in accordance with the present invention is the cured product of a blend comprising:
95-100 weight percent of natural rubber~ polyisoprene or a mixture thereof, 0-5 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 30-50 phr, based on the total rubber content, of carbon black having an average particle size of 20-40 nm., 0.5-4.0 phr of activator, 1.0-lO.O phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator.
SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 ~`` 2122347 Other additives such as 1-4 phr antiozonants, may be employed.
Important properties for conveyor belts are fatigue resistance, abrasion resistance and tear strength.
A typical V-belt in accordance with the present invention is the cured product of a blend comprising:
SO-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 30-65 phr, based on the total rubber content, of carbon black having an average particle size of 20-100 nm, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator.
Other additives such as 1-4 phr antiozonants, may be employed.
Important properties for V-belts are fatigue resistance and service life.
Examples of sulfur which may be used in the present invention include various types of sulfur such as powdered sulfur, precipitated sulfur and insoluble sulfur. Also, sulfur donors may be used in place of, or -~ in addition to sulfur in order to provide the required level of sulfur during the vulcanization process. Examples of such sulfur donors include, but are not limited to, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipen-tamethylene thiuram hexasulfide, dipentamethylene thiuram tetrasulfide, dithiodimorpholine, caprolactam disulfide and mixtures thereof.
WO 93/09178 PCI`~EP92/01030 212~347 8 In this text, references to sulfur shall include sulfur donors and mixtures of sulfur and sulfur donors. Further, references to the quantity of sulfur employed in the vulcanization, when applied to sulfur donors, refer to a quantity of sulfur donor which is required to provide the equivalent amount of sulfur that is specified.
In most circumstances it is also desirable to have a vulcanization accelerator in the rubber compound. Conventional, known vulcanization accelerators may be employed. The preferred vulcanization accelera-tors include mercaptobenzothiazole, 2,2'-mercaptobenzothiazole disulfide, sulfenamide accelerators including N-cyclohexyl-2-benzothiazole sulfenamide, N-tertiary-butyl-2-benzothiazole sulfenamide, N,N'-dicyclohexyl-2-benzothiazole sulfenamide, and 2-(morpholinothio)benzothiazole; thiophosphoric acid derivative accelerators, thiurams, dithiocarbamates, diphenyl guanidine, diortho-tolyl guanidine, dithiocarbamylsulfenamides, xanthates, triazine acce-lerators and mixtures thereof.
Other rubber additives may also be employed in their usual amounts.
For example, reinforcing agents such as carbon black9 silica, clay, whiting and other mineral fillers, as well as mixtures of fillers, may be included in the rubber composition. Other additives such as process oils, tackifiers, waxes, antioxidants, antiozonants, pigments, resins, plasticizers, process aids, factice, compounding agents and activators such as stearic acid and oleic acid, and zinc oxide may be included in the listed amounts. For a more complete listing of rubber additives which may be used in combination with the present invention see, W. Hofmann, ~Rubber Technology Handbook", Chapter 4, Rubber Chemicals and Additives, pp. 217-353, Hanser Publishers, Munich 1989.
Further, scorch retarders such as phthalic anhydride, pyromellitic anhydride, benzene hexacarboxylic trianhydride, 4-methylphthalic anhydride, trimellitic anhydride, ~-chlorophthalic anhydride, N-- SUBSTITUTE SHEET
WO 93/09178 P~/EP92/01030 cyclohexyl-thic~halimides salicylic acid, benzoic acid, maleic anhydride and N-nitrosodiphenylamine may also be included in the rubber composition in conventional, known amounts. Finally, in speci-fic applications it may also be desirable to include steel-cord adhe-sion promoters such as cobalt salts and dithiosulfates in conven-tional, known quantities.
The process of curing the blends of the present invention is preferably carried out at a temperature of 110-220C over a period of up to 24 hours. More preferably, the process is carried out at a temperature of 120-190C over a period of up to 8 hours. All of the additives mentioned above with respect to the rubber composition may also be present during the vulcanization process.
In a more preferred embodiment of the vulcanization process, the vulcanization is carried out at a temperature of 120-190~C over a period of up to 8 hours and in the presence of at least one vulca-nization accelerator. The best heat buildup in accordance with the present invention is found when vulcanization is carried out at a temperature above 160C and~or for a period exceeding tgo.
The tire and belt products of the present invention have reduced heat buildup. With respect to the tire products, they exhibit a heat buildup of 20-35C whereas the belt products exhibit a heat buildup of from 10-35C.
Heat buildup, for the purposes of the present specification, was measured using ASTM 623 A at a starting temperature of 100C. The actual heat buildup is the temperature rise from 100C to the temperature at which equilibrium was reached. Equilibrium temperature is when the temperature stabilizes and does not rise any further.
Note that for some prior art products, the temperature never stabilizes.
~UBSTITUTE SHEET
WO 93/0917~ PCI'/EP92/01030 2 1 2 ~ ~ 4 7 One way to produce products in accordance with the present invention is to carry out the curing of the blend in the presence of 0.1-5.0 parts by weight of a coagent represented by the general formula A:
Q1-D-(Q2)n (A);
wherein D, optionally containing one or more heteroatoms or groups selected from nitrogen, oxygen, silicon, phosphorus, boron, sulphone and sulphoxy, is a monomeric or oligomeric divalent, trivalent or tetravalent group, n is an integer selected from 1, 2 or 3, Q1 and Q2 are independently selected from the formulas I and II:
C~ C-C-H
/ l -N R2 (I) C~ C-R3 20 and;
B R
Il /
C----------------C=C
\
-N R2 (II) 1l _ _ l-R3 B~ H
wherein R1, R2 and R3 are independently selected from hydrogen, C1-C1g alkyl groups, C3-C1g cycloalkyl groups, C6-C1g aryl groups, C7-C30 aralkyl groups and C7-C30 alkaryl groups and R2 and R3 may combine to form a ring when R1 is hydrogen; B and B~ are independently selected from the following hetero atoms: oxygen and sulfur.
~UBSTITUTE SHEET
WO 93/09178 PCl`/EP92/01030 These imides are, in general, known compounds and may be prepared by the methods disclosed in, "The synthesis of Biscitraconimides and Polybiscitraconimides~" Galanti, A.V. and Scola, D.A., Journ. of Poly.
- Sci.: Polymer Chemistry Edition, Vol. 19, pp. 451-475, (1981), and "The Synthesis of Bisitaconamic Acids, Isomeric Bisimide Monomers9"
Galanti, A.V. et al., Journ. Poly. Sci.: Polymer Chemistry Edition, Vol. 20, pp. 233-239 (1982) and Hartford, S.L., Subramanian, S. and Parker, J.A., Journ. Poly. Sci.: Polymer Chemistry Edition, Vol. 16, p. 137, 1982, the disclosures of which are hereby incorporated by reference. Particularly useful imide compounds are disclosed in PCT
patent application PCT/EP 91/02048.
The invention is further illustrated by the following examples which are not to be construed as limiting the invention in any way. The scope of the invention is to be determined from the claims appended hereto.
EXPE~IMENTAL METHODS USED IN THE EXAMPLES
Compounding, Vulcanization and Characterization of Compounds In the following examples, rubber compounding, vulcanization and testing was carried out according to standard methods except as otherwise stated:
Base compounds were mixed in a Farrel Bridge BR 1.6 liter Banbury type internal mixer (preheating at 50C, rotor speed 77 rpm, mixing time 6 min with ~ull cooling).
~ulcanization ingredients and coagents were addded to the compounds on a Schwabenthan Polymix 150L two-roll mill (friction 1:1.22, temperature 70C, 3 min).
SUBSTITUTE SHEET
WO 93/09178 PCr/EP92tO1030 212~347 .
Optimum cure time (tgo) is the time- to 90% of delta torque above minimum, reversion time (tr2) is the time to 2% of delta torque below maximum torque. Final torque (Tf) is the torque measured after the overcure time.
Sheets and test specimens were vulcanized by compression molding in a Fontyne TP-400 press.
Tensile measurements were carried out using a Zwick 1445 tensile tester (ISO-2 dumbbells, tensile properties according to ASTM D
412-87, tear strength according to ASTM D 624-86).
Hardness was determined according to DIN 53505, and ISO 48 (IRHD).
Rebound resilience was measured at room temperature (RT) according to ASTM D 1054-87.
Compression set was determined after 24 h at 70C or 72 h at 23C
according to ASTM D 395-89.
Heat build-up temperature rise and compression set after dynamic loading were determined using a Goodrich Flexometer (load 1 MPa, stroke 0.445 cm, frequency 30 Hz, start temperature 100C, running time 30 min; ASTM D 623-78). Blow out time was determined according to ASTM D 623-78 ~load 2 MPa, stroke 0.645 cm, frequency 30 Hz, start temperature 100C).
Abrasion was determined using a Zwick abrasion tester as volume loss per 40 m path traYelled (DIN 53516~.
Ageing of test specimens was carried out in a ventilated air oven at 70C or 100C for periods up to 14 days (ISO 188) SU BS~rITUlnE S HEE~r WO 93J09178 P~/EP92/01030 Examples 1 3 and Comparative Example A
- Examples 1-3 and Comparative Example A are formulations for truck tire treads. The components of each formulation are given in Table 1 and the physical and mechanical properties for different curing conditions are given in Tables 2a-2d. The heat buildup and permanent set are given for di~ferent curing conditions in Tables 3a-3b.
TABLE 1: Compound composition Ingredient _ _ _ 1 2 3 BR Buna C3 10 20 20 20 20 Carbon Black N-375 55 -55 55 55 Stearic Acid 2 2 2 2 ZnO RS 4 4 4 4 Ar.Oil Dutrex 729HP 8 8 8 8 Permanax 6PPD (R) 2 2 2 2 Perkacit CBS c 1.2 1.2 1.2 1.2 Sulphur 1.2 1.2 1.2 1.2 Coagent BCI-MX* _ _ 0.75 1 1.25 * BCI-MX = N,N'-m-xylene-bis-citraconic imide TABLE 2a: Physical and mechanical properties of the vulcanizates cured at 150C for tgo Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 69 69 68 69 Tensile strength MPa 25.6 26.2 23~9 26.1 Elongation ~ 533 535 502 545 Modulus 50% MPa 1.4 1.3 1.3 1.3 Modulus 100~ MPa 2.6 2.4 2.4 2.3 Modulus 300~ MPa 13.1 12.9 12.5 12.5 Rebound res~lience ~ 32 33 32 32 Abrasion mm3 87 100 __ _ _ SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 21?.23~7 TABLE 2b: Physical and mechanical properties of the vulcanizates cured at 150C for 60 min Test A 1 2 3 Density g/cm3 1 .12 1.12 1.12 1.12 Hardness IRHD 65 69 68 68 Tensile strength MPa 23.7 23. 7 22.5 23.6 Elongation % 534 536 498 506 Modulus 50% MPa 1.3 1.4 1.4 1.4 Modulus 100~ MPa 2. 2 2.3 2.4 2.3 Modulus 300% MPa 11.4 11.8 12.0 12.3 Rebound resilience %_ _ 30 32 31 32 TABLE 2c: Physical and mechanical properties of the vulcanizates cured at 170~C for tgo Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 68 66 67 67 Tensile strength MPa 25. 3 25.6 24.5 24.5 Elongation ~ 541 557 548 532 Modulus 50% MPa 1.3 1.3 1.2 1.2 Modulus 100% MPa 2.3 2.1 2.2 2.1 Modulus 300% MPa 12.4 11.6 11.8 11.7 Rebound resilience % 32 33 31 32 TABLE 2d: Physical and mechanical properties of the vulcanizates cured at 170C for 30 min Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 62 66 66 67 Tensile strength MPa 18.4 21.2 20.4 22.3 Elongation % 511 510 482 502 Modulus 50% MPa 1.1 1.2 1.2 1.3 Modulus 100% MPa 1. 7 2.0 2.1 2.2 Modulus 300% MPa 8.9 10.7 10.9 11.5 Rebound resilience % 29 30 31 31 SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 212~3~7 TABLE 3a: Heat build up and Permanent set of the vulcanizates cured at 170C for 30 min ITest I A 1 1 1 2 1 3 Heat build up C 51 34 33 34 Permanen~ set % 18.0 10.2 9.5 7.9 _ TABLE 3b: Hsat build up and Permanent set of the vulcanizates cured at 150C for 2 x tgo Test A 1 2 Heat build up C 48 34 32 34 Permanent set _ % 17.8 13.0 11.0 13.4 Example 4 and Comparative Example B
Example 4 and Comparative Example B are also formulations for truck tire treads. The components of each formulation are given in Table 4 and the physical and mechanical properties for different curing ccnditions are given in Tables 5a-5b. The heat buildup and permanent set are given for different curing conditions in Tables 6a-6b.
TABLE 4: Compound composition _ Recipes Ingredients ~ B 4 NR SMR 20 80.00 80.00 BR Buna CB 10 20.00 20.00 Carbon Black N-375 55.00 55.00 Stearic Acid 2 . 00 2 . 00 Zinc Oxide RS 4.00 4.00 Ar.Oil Dutrex 729HP 8.00 8.00 Permanax 6PPD 2.00 2.00 Perkacit CBS c 1.20 1.20 Sulphur 1.20 1.20 BCI-MX _ _ ___ _ 1.00 ~3UBSTITUTE SHEET
WO 93/09178 PCl'/EP92/01030 TABLE 5a: Mechanical properties of the vulcanization cured at 150C
for tgo times . _ Recipes Properties _ _ 4 Modulus, MPa 50~ 1.16 1.20 (1.06) (1.20) 100% (1 97) 2 08 300% 11 .52 11 .40 (9.37) (10.87) Tensile strength, 26.60 27.23 MPa (22 .20) (22 .87) Elongation,% 565 580 Tear strength, 94.5 100 kN/m (8~) (84) Rebound resilience, % (32) (32) Hardness, Shore A (54) (58) * Values in the parentheses designate the properties of the vulcantizates cured at 150C for 60 min.
SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 212~47 TABLE 5b: Mechanical properties of the vulcanization cured at 170C
for tgo times Recipes Properties B 4 Modulus, MPa 50% 1.11 1.09 (0-93) (1.16) 100~ 1.79 1.7~
(1-~7) (1.90) 300% 9.73 10.06 (6.95) (10.19) Tensile strength, 24.50 25.63 MPa (16.49) t22.56) Elongation,~ 576 579 (522) (540) Tear strength, 110 105 kN/m (49) (69) Rebound resilience, % 57 58 ~ ss, Shore A (53) ¦ ~
* values in the parentheses designate the relevant properties of the vulcanizates cured at 170C for 30 min.
~UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 2122~47 Table 6a: Heat build up and permanent set properties (at 100C) of the vulcanizates cured at 150C for tgo*2 and 60 minutes Stro~e 4.45 mm, Load: 11 kg, Freqùency: 30Hz Start Temp.: 100C, Duration: 25 minutes UNAGED
Sample HBU,C Permanent Set,%
4 34 14.06 (27) (8.20) AGED, 7d/70C
B 55 18.08 (65) (25.39) 4 25 9.52 (27) (6.61) AGED, 14d/70C
B 56 20.47 (100) (Blown out) _ (227) (86 88) *values in the parentheses designate the properties of the . vulcanizates cured at 150C for 60 minutes ~UBSTITUTE SHEET
21223~7 Table 6b: Heat build up and permanent set properties (at 100C) of the vulcanizates cured at 170C for tgo*2 and 30 minutes Stroke: 4.45 mm, Load- 11 kg, Frequency: 30Hz Start Temp.: 100C, Duration: 25 minutes UNAGED
Sample HBU,C Permanent Set,%
~ 47 ~1.54 (52) (18.05) 4 34 1~.75 (~8) (7.43) AGED, 7d/70C
B 46 19.78 (83) (30.27) 4 27 11.02 (29~ (7-31) AGED,_14d/70C
B (112) (Blown out) 4 26 8.58 (30) (6.93) . _ *values in the parentheses designate the properties of the vulcanizates cured at 170C for 30 minutes Examples 5-7 and Comparative Examples C-D
Examples 5-7 and Comparative Examp~es C-D are formulations for off-the-road tire treads. The components of each formulation are given in Table 7 and the physical and mechanical properties for different curing conditions are given in Tables 8a-8d. The heat buildup and permanent set are given for different curing conditions in Tables 9-10.
SUBSTITUTE SHEET
WO 93/09178 PC~JEP92/01030 21223~
TABLE 7: Compound composition Ingredients _ _ C 5 6 7 D
Carbon Black N-220 40 40 40 40 40 Perkasil KS 404 Gr 20 20 20 20 20 Zinc Oxide RS 5 5 5 5 5 Steari c Acid 2 2 2 2 2 Ar.Oil Dutrex 729HP 3 3 3 3 3 Resin Cumar. 3 3 3 3 3 Si-69 3 3 3 3 3 Permanax TQ 1.5 1.5 1.5 1.5 1.5 Permanax 6PPD 2.5 2.5 2.5 2.5 2.5 Wax Sunolite 240 1 1 1 1 Perkacit CBS c 1.41 1.41 1.41 1.41 1.41 Sulfur 1.43 1.43 1.43 1.43 1.43 BCI-MP* 1.0 _ _ BCI-MX 1.0 BCI-ES2** 1.0 Duralink HTS __ 1.0 * BCI-MP = N,N'-m-phenylene-bis-citraconic imide ** BCI-ES2 = bis(2-citraconimidoethyl)disulfide TABLE 8a: Physical and mechanical properties of vulcanizates cured at 150C for tgo Test ~ 5 6 7 D
Density g/cm3 1.16 1.16 1.16 j 1.16 1.16 Hardness IRHD 70 74 70 68 67 Tensile strength MPa 23.7 23.1 23.8 23.5 22.5 Elongation % 507 494 522 495 503 Modulus 50% MPa 1.3 1.4 1.3 1.4 1.3 Modulus 100% MPa 2.6 2.7 2.5 2.6 2.3 Modulus 300% MPa 12.8 12.9 12.2 12.9 11.5 Rebound resilience % 29 28 29 30 31 Tear Strength kN/m 128 108 100 114 92 Compr.set 3 days 23C % 14 15 16 15 16 Compr.set 1 day 70C % 32 29 31 28 33 ~UBSTITUTE SHEET
212~3~ 7 TABLE 8b: Physical and mechanical properties of vulcanizates cured at 150C for 60 min Test _ 5 6 7 D .
Density ~ lcm3 1.16 1.161.16 1.16 1.16 Hardness IRHD 70 74 72 73 69 Tensile strength MPa 20.9 24.1 23.5 25.0 19.7 Elongation % 458 441 457 475 436 Modulus 50% MPa 1.4 1.7 1.6 1.7 1.3 Modulus 100% MPa 2.8 3.6 3.2 3.5 2.6 Modulus 300~ MPa 13.2 16.6 15.4 15.7 12.6 Rebound resilience % 26 29 30 28 28 Tear Strength kN/m 51.2 84.8 ~80.1 71.9 52.6 Compr.set 3 days 23C % 16 15 15 13 15 Compr.set 1 day 70C % l_ 24 23 22 22 24 TABLE 8c: Physical and mechanical properties of the vulcanizates cured at 170C for tgo Test C 5 6 7 D
Density g/cm' 1.16 1.161.16 1.16 1.16 Hardness IRHD 67 73 67 73 67 Tensile strength MPa 21.9 22.3 20.2 21.2 20.6 Fl ongation % 522 476 508 462 502 Modulus 50~ MPa 1.2 1.5 1.2 1.5 1.2 Modulus 100% MPa 2.2 2.7 2.1 2.6 2.1 Modulus 300~ MPa 11.0 12.5 10~2 12.5 10.4 Rebound resilience % 29 27 28 27 28 Tear Strength kN/m 96 65 - 76 67 82 , Compr.set 3 days 23C % 16 16 18 17 18 Compr.set 1 day 70C % 36 26 37 ~ 25 38 .
~UBSTITUTE SHEET
WO 93/09178 P~/EP92/01030 21~2347 TABLE 8d: Physical and mechanical properties of the vulcanizates cured at 170C for 30 min Test - C r 5 7 D
Density -- 97 cm3 i.16 1.16 1.16 1.161.16 Hardness IRHD 69 75 74 74 69 Tensile strength MPa 17.2 21.0 21.6 22.3 17.5 Elongation % 433 415 446 416 451 Modulus 50% MPa 1.3 1.6 1.5 1.7 103 Modulus 100% MPa 2.3 3.0 2.9 3.4 2.2 Modulus 300% MPa 10.8 14.4 13.4 15.6 10.6 Rebound resilience % 29 27 27 27 26 Tear Strength kN/m 75 75 60 59 27 Compr.set 3 days 23C % 20 15 17 16 19 Compr.set 1 day ?oC % 27 22 24 22 _ 27 TABLE 9: Dynamic properties of the vulcanizates oured at 150C for tgo*2 Compounds Control BCI-MP BCI-MX BCI-ES2 Dura.HTS
(C) (5) (6) (7) (D) PPHR -- 1.0 1.0 1.0 1.0 GOODRICH FLEXOMETER
Stroke: 4.45mm, Temp.: 100C, Frequency: 30 Hz, Duration: 25 min Heat Build-up,C 48 24 28 24 48 (46) (24) (~3) (25) (46) Set,% 23.1 7.2 11.7 8.9 22.5 t15.2) t5.2) (5.0) (6.3~ (17.6) Stroke- 6.45mm,_Temp.: 100C~ Frequency: 30Hz Blow out times 3.5 7.2 4.5 7.0 4.2 minutes (3~ (9.3) (8.0)~ (6.0) (4.0) Values in the parentheses are those for the vulcanizates at 150C for 60 minutes 3~
~3UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 212~3 17 TABLE 10: Dynamic properties of the vulcanizates cured at 170C for tgo*2 Compounds Control BCI-MP BCI-MX BCI-ES2 Dura.HTS
(C) (5) (6) (7) (D) PPHR -- 1,0 1.0 1.0 1.0 ~OODRICH FLEXOMETER
Stroke: 4.45mm, Temp.:_100C, Frequency: 30 Hz, Duration: 25 min Heat Build-up,C 49 24 34 24 49 (47) (24) (25) (27) (46) 10Set,% 27.9 2.9 17.0 5.5 29.6 (15.7) (4.8) ~5.8~ (6.0) (16.5) Stroke: 6.45 mm, Temp.: 100C, Frequency-. 30Hz B ow out times 4.0 10.0 4.5 10.0 3.5 minutes (4.0) (11.0) (8.0) (9.0)_ (3.75) Values in the parentheses designate the values obtained for the vulcanizates cured at 170C for 30 minutes Example 8 and Comparative Examples E-F
Example 8 and Comparative Examples E-F are formulations for conveyor belts. The components of each formulation are given in Table 11 and the physical and mechanical properties for different curing conditions are given in Tables 12a-12b. The heat buildup and permanent set are given for different curing conditions in Table 13.
TABLE 11: Compound composition Ingredient E F
Black N-330 45 45 45 Dutrex 729 H 4 4 4 ZnO RS 5 5 5 Stearic Acid 2 2 2 Sulfur 2.5 2,5 2.5 Perkacit CBS - 0.5 0.5 0.5 BCI-MX _ 1.0 HVA-2 _ _ __ 1.0 SUBSTITUTE SHEET
TABLE 12a: Mechanical properties (vulcanization 150C, tgo) Test E 8 F
S Hardness ~ I~HD 69 71 71 Tensile strength MPa 26.4 25.8 25.6 Elongation % ?75 465 470 Modulus 50% MPa 1.6 1.6 1.5 Modulus 100% MPa 3.4 3.1 3.2 Modulus 300% MPa 15.4 14.5 14.8 Rebound resilience % 38 37 37 Tear strength kN/m 73 91 81 Abrasion mm3 124 128 136 Compr.set 72h/23C % 9 10 10 Density g/cc 1.12 1.12 1.12 Compr.set 24h/70C % 23 24 23 Heat build up C 25 17 25 Permanent set % 8.6 5.8 _7.4 TABLE 12b: Mechanical properties (vulcanization 170C, 30 min) Test E 8 F
Hardness IRHD 59 68 64 Tensile strength MPa 14.1 19.8 17.0 Elongation % 415 415 445 Modulus 50% MPa 1.1 1.5 1.2 Modulus 100% MPa 1.9 2.8 2.2 Modulus 300% MPa 8.8 13.0 10.1 Rebound resilience % 32 35 33 Tear strength kN/m 20 29 21 . Abrasion mm3 ~ _ __ __ Compr.set 72h/23C % 20 11 19 Density g/cc 1.12 1.12 1.12 Compr.set 24h/70C % 30 19 27 Heat build up C 46 20 ~3 Permanent set % _16.4 3.2 9.3 . .
SUBSTITUTE SHEET
WO 93/09178 21 2 2 3 4 7 PCl'/EP92/01030 TABLE 13: Ageing properties (vulcanization 150C, tgo) Test E 8 F
Ageing medium air air air Ageing temperature C 100 100 100 Ageing time day(s) 3 3 3 Hardness IRHD 73 76 74 Change in Hardn. IRHD + 4 + 5 + 3 Tensile strength MPa 13.7 16.2 14.9 Change in T.S. % -48 -37 -42 Elongation % 230 225 230 Change in Elong. % -52 -52 -51 Modulus 50% MPa 2.3 2.5 2.4 Change in M50% % +44 +56 +50 Modulus 100% MPa 5.0 5.5 5.3 Change in M100~ % +47 +77 +66 ~3UBSTITlJTE SHEET
The importance of heat buildup is recognized in the article, "Carbon Black in NR/BR Blends for Truck Tires,'l Rubber Chemistr~ and Technology, Vol. 58, pp. 350-36B (1985), wherein it is stated that treadwear, heat buildup, resistance to cutting and chipping and fuel economy are important to heavy duty truck tire performance.
Accordingly, there is a need in the art for tire and belt products which exhibit a low heat buildup. since such products exhibit a better performance as well as having, in many`cases, a longer service life.
Many attempts have been made to produce products with a low heat buildup. ~or example~ European Patent application 0 314 271 discloses the use of an improved processing aid to improve handling, durability and rolling resistance of tires, as well as reducing heat buildup.
European Patent application 0 451 603 relates to the use of an anionic polymerization initiator for curing elastomers to improve their hysteresis. ~mproved hysteresis leads to tires having a lower rolling resistance. One aspect of hysteresis is heat buildup.
PCT patent application WO 91/05821 discloses a tire sidewall composition comprising a particular polymer which leads to sidewalls having a desirable reduced internal heat buildup and improved adhesion to adjacent rubber carcass and tread portions of the tire.
~3UBSTITUTE StlEET
WO 93/09178 PCI`/EP92/01030 21223~7 Finally, the publication, "Natural Rubber Compounds for Truck Tires,"
NR Technology, Vol. 16, Part 1 (1985) suggests the use of additional stearic acid activator in order to reduce the heat generation, among other properties, in truck tires.
However, all of these solutions fall short of the goal of providing tires and belts with longer service life, better ageing characteristics, lower rolling resistance and better fuel economy.
The present inventors have surprisingly found that tire and belt compositions having a particular heat buildup exhibit several improved properties, particularly when the tires and belts are subjected to service conditions.
More specifically, the present invention relates, in one aspect to a tire wherein at least one of the tread, steel-cord skim stock, sidewall and carcass portions contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator, . . .
characterized in that said rubber composition has a heat buildup of 20-35C. These tires exhibit one or more improvements in a wide variety of properties such as abrasion resistance, rolling resistance, ageing resistance, adhesion to steel, cutting and chipping resistance and service life.
SUBSTITUTE SHEET
212~347 In a second aspect, the present invention relates to a belt which contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber~ styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 10-25C. These belts exhibit one or more improv~ments in a variety of properties including tear strength, tensile strength, service life and ageing resistance.
The low heat buildup rubber compositions of the present invention can be used in tire treads for truck tires and off-the-road tires, in particular, for sidewalls, for tire carcasses and for steel-cord skim stocks. In belts, the rubber compositions of the present invention are particularly useful for conveyor belts and V-belts which are subjected to high loading and abrasion in service.
2g A typical truck tire tread composition in accordance with the present invention comprises the cured product of a blend containing:
50-100 we-ight percent of natural rubber~ polyisoprene or a mixture 30 thereof, 0 50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 45-65 phr, based on the total rubber content, of carbon black, 1.0-3.0 phr of activator, ~3UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 2122~47 1.0~10.0 phr of zinc oxide, 1.0-5.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator.
Of course, these truck tire treads may contain other conventional additives such as 0-20 phr silica, 2-10 phr tackifier, 5-50 phr of processing oil, 1-5 phr waxes, 1-5 phr antioxidant and 1-5 phr antiozonants.
Important properties for truck tire treads include abrasion resistance, rolling resistance, resistance. to cracking, thermal and oxidative stability and durability.
A typical steel-cord skim stock composition in accordance with the present invention is the cured product of a blend comprising:
85-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-15 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 45-65 phr, based on the total rubber content, of carbon black having an average particle size of 10-30 nm, 0.5-2.0 phr of activator, 1.0-10.0 phr of zinc oxide, 4.0-8.0 phr of sulfur or a sulfur donor, and 0.5-1.5 phr of curing accelerator.
These steel-cord skim stocks may also contain 0-20 phr silica, 0-2.0 phr of a cobalt salt and 1-3 phr of antidegradants. Adhesion to steel is an important property for this portion of the tire.
A typical carcass portion of a tire in accordance with the present invention is the cured product of a blend comprising:
~3UBSTITUTE SHEET
WO 93/09178 P~/EP9~/01030 21223~
50-80 weight percent of natural rubber, polyisopr~ne or a mixture thereof, 20-50 weight percent of butadiene rubber~ styrene-butadiene rubber or a mixture thereof, 20-50 phr, based on the total rubber content, of carbon black having an average particle size of 45 70 nm, 1.0-3.0 phr of activator, 1.0-10.0 phr of zinc oxide, 2.0-5.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator.
These carcass portions may a~so contain 1-3 phr antioxidant and 2-8 phr processing oil, if desired. Important properties fcr the carcass portion are the thermal resistance and the rebound resilience.
A typical sidewall portion of a tire in accordance with the present invention is the cured product of a blend comprising:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 40-60 phr, based on the total rubber content, of carbon btack having an average particle size of 20-70 nm, 1.0-4.0 phr of activator, 2.0-6.0 phr of zinc oxide, 1.0-3.0 phr of sulfur or a sulfur donor, and 0.5-1.5 phr of curing accelerator.
These sidewall portions may also contain from 5-10 phr of whitening.
Important properties for the sidewall portion are fatigue resistance, ozone resistance, cutting and chipping resistance and reversion resistance.
~UBSTITUTE SHEET
2~223~
A typical off-the-road tire tread in accordance with the present invention is the cured product of a blend which comprises:
80-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-20 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-50 phr, based on the total rubber content, of carbon black having an average particle size of 10-30 nm, 1.0-3.0 phr of activator, 1.0-10.0 phr of zinc oxide, 10-25 phr of silica having a surface area of 100-200 m2/g, 1.0-2.0 phr of sulfur or a sulfur donor, and 1.0-2.0 phr of curing accelerator.
Off-the-road tîre treads may also include 5-50 phr of processing oil, 0-5 phr of resin, 0-2 phr wax, 1-4 phr antio~onants and 0.5-2.0 phr antioxidants. Important properties for off-the-road tire treads are tread wear, cutting and chipping resistance and hysteresis.
A typical conveyor belt in accordance with the present invention is the cured product of a blend comprising:
95-100 weight percent of natural rubber~ polyisoprene or a mixture thereof, 0-5 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 30-50 phr, based on the total rubber content, of carbon black having an average particle size of 20-40 nm., 0.5-4.0 phr of activator, 1.0-lO.O phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator.
SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 ~`` 2122347 Other additives such as 1-4 phr antiozonants, may be employed.
Important properties for conveyor belts are fatigue resistance, abrasion resistance and tear strength.
A typical V-belt in accordance with the present invention is the cured product of a blend comprising:
SO-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 30-65 phr, based on the total rubber content, of carbon black having an average particle size of 20-100 nm, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator.
Other additives such as 1-4 phr antiozonants, may be employed.
Important properties for V-belts are fatigue resistance and service life.
Examples of sulfur which may be used in the present invention include various types of sulfur such as powdered sulfur, precipitated sulfur and insoluble sulfur. Also, sulfur donors may be used in place of, or -~ in addition to sulfur in order to provide the required level of sulfur during the vulcanization process. Examples of such sulfur donors include, but are not limited to, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipen-tamethylene thiuram hexasulfide, dipentamethylene thiuram tetrasulfide, dithiodimorpholine, caprolactam disulfide and mixtures thereof.
WO 93/09178 PCI`~EP92/01030 212~347 8 In this text, references to sulfur shall include sulfur donors and mixtures of sulfur and sulfur donors. Further, references to the quantity of sulfur employed in the vulcanization, when applied to sulfur donors, refer to a quantity of sulfur donor which is required to provide the equivalent amount of sulfur that is specified.
In most circumstances it is also desirable to have a vulcanization accelerator in the rubber compound. Conventional, known vulcanization accelerators may be employed. The preferred vulcanization accelera-tors include mercaptobenzothiazole, 2,2'-mercaptobenzothiazole disulfide, sulfenamide accelerators including N-cyclohexyl-2-benzothiazole sulfenamide, N-tertiary-butyl-2-benzothiazole sulfenamide, N,N'-dicyclohexyl-2-benzothiazole sulfenamide, and 2-(morpholinothio)benzothiazole; thiophosphoric acid derivative accelerators, thiurams, dithiocarbamates, diphenyl guanidine, diortho-tolyl guanidine, dithiocarbamylsulfenamides, xanthates, triazine acce-lerators and mixtures thereof.
Other rubber additives may also be employed in their usual amounts.
For example, reinforcing agents such as carbon black9 silica, clay, whiting and other mineral fillers, as well as mixtures of fillers, may be included in the rubber composition. Other additives such as process oils, tackifiers, waxes, antioxidants, antiozonants, pigments, resins, plasticizers, process aids, factice, compounding agents and activators such as stearic acid and oleic acid, and zinc oxide may be included in the listed amounts. For a more complete listing of rubber additives which may be used in combination with the present invention see, W. Hofmann, ~Rubber Technology Handbook", Chapter 4, Rubber Chemicals and Additives, pp. 217-353, Hanser Publishers, Munich 1989.
Further, scorch retarders such as phthalic anhydride, pyromellitic anhydride, benzene hexacarboxylic trianhydride, 4-methylphthalic anhydride, trimellitic anhydride, ~-chlorophthalic anhydride, N-- SUBSTITUTE SHEET
WO 93/09178 P~/EP92/01030 cyclohexyl-thic~halimides salicylic acid, benzoic acid, maleic anhydride and N-nitrosodiphenylamine may also be included in the rubber composition in conventional, known amounts. Finally, in speci-fic applications it may also be desirable to include steel-cord adhe-sion promoters such as cobalt salts and dithiosulfates in conven-tional, known quantities.
The process of curing the blends of the present invention is preferably carried out at a temperature of 110-220C over a period of up to 24 hours. More preferably, the process is carried out at a temperature of 120-190C over a period of up to 8 hours. All of the additives mentioned above with respect to the rubber composition may also be present during the vulcanization process.
In a more preferred embodiment of the vulcanization process, the vulcanization is carried out at a temperature of 120-190~C over a period of up to 8 hours and in the presence of at least one vulca-nization accelerator. The best heat buildup in accordance with the present invention is found when vulcanization is carried out at a temperature above 160C and~or for a period exceeding tgo.
The tire and belt products of the present invention have reduced heat buildup. With respect to the tire products, they exhibit a heat buildup of 20-35C whereas the belt products exhibit a heat buildup of from 10-35C.
Heat buildup, for the purposes of the present specification, was measured using ASTM 623 A at a starting temperature of 100C. The actual heat buildup is the temperature rise from 100C to the temperature at which equilibrium was reached. Equilibrium temperature is when the temperature stabilizes and does not rise any further.
Note that for some prior art products, the temperature never stabilizes.
~UBSTITUTE SHEET
WO 93/0917~ PCI'/EP92/01030 2 1 2 ~ ~ 4 7 One way to produce products in accordance with the present invention is to carry out the curing of the blend in the presence of 0.1-5.0 parts by weight of a coagent represented by the general formula A:
Q1-D-(Q2)n (A);
wherein D, optionally containing one or more heteroatoms or groups selected from nitrogen, oxygen, silicon, phosphorus, boron, sulphone and sulphoxy, is a monomeric or oligomeric divalent, trivalent or tetravalent group, n is an integer selected from 1, 2 or 3, Q1 and Q2 are independently selected from the formulas I and II:
C~ C-C-H
/ l -N R2 (I) C~ C-R3 20 and;
B R
Il /
C----------------C=C
\
-N R2 (II) 1l _ _ l-R3 B~ H
wherein R1, R2 and R3 are independently selected from hydrogen, C1-C1g alkyl groups, C3-C1g cycloalkyl groups, C6-C1g aryl groups, C7-C30 aralkyl groups and C7-C30 alkaryl groups and R2 and R3 may combine to form a ring when R1 is hydrogen; B and B~ are independently selected from the following hetero atoms: oxygen and sulfur.
~UBSTITUTE SHEET
WO 93/09178 PCl`/EP92/01030 These imides are, in general, known compounds and may be prepared by the methods disclosed in, "The synthesis of Biscitraconimides and Polybiscitraconimides~" Galanti, A.V. and Scola, D.A., Journ. of Poly.
- Sci.: Polymer Chemistry Edition, Vol. 19, pp. 451-475, (1981), and "The Synthesis of Bisitaconamic Acids, Isomeric Bisimide Monomers9"
Galanti, A.V. et al., Journ. Poly. Sci.: Polymer Chemistry Edition, Vol. 20, pp. 233-239 (1982) and Hartford, S.L., Subramanian, S. and Parker, J.A., Journ. Poly. Sci.: Polymer Chemistry Edition, Vol. 16, p. 137, 1982, the disclosures of which are hereby incorporated by reference. Particularly useful imide compounds are disclosed in PCT
patent application PCT/EP 91/02048.
The invention is further illustrated by the following examples which are not to be construed as limiting the invention in any way. The scope of the invention is to be determined from the claims appended hereto.
EXPE~IMENTAL METHODS USED IN THE EXAMPLES
Compounding, Vulcanization and Characterization of Compounds In the following examples, rubber compounding, vulcanization and testing was carried out according to standard methods except as otherwise stated:
Base compounds were mixed in a Farrel Bridge BR 1.6 liter Banbury type internal mixer (preheating at 50C, rotor speed 77 rpm, mixing time 6 min with ~ull cooling).
~ulcanization ingredients and coagents were addded to the compounds on a Schwabenthan Polymix 150L two-roll mill (friction 1:1.22, temperature 70C, 3 min).
SUBSTITUTE SHEET
WO 93/09178 PCr/EP92tO1030 212~347 .
Optimum cure time (tgo) is the time- to 90% of delta torque above minimum, reversion time (tr2) is the time to 2% of delta torque below maximum torque. Final torque (Tf) is the torque measured after the overcure time.
Sheets and test specimens were vulcanized by compression molding in a Fontyne TP-400 press.
Tensile measurements were carried out using a Zwick 1445 tensile tester (ISO-2 dumbbells, tensile properties according to ASTM D
412-87, tear strength according to ASTM D 624-86).
Hardness was determined according to DIN 53505, and ISO 48 (IRHD).
Rebound resilience was measured at room temperature (RT) according to ASTM D 1054-87.
Compression set was determined after 24 h at 70C or 72 h at 23C
according to ASTM D 395-89.
Heat build-up temperature rise and compression set after dynamic loading were determined using a Goodrich Flexometer (load 1 MPa, stroke 0.445 cm, frequency 30 Hz, start temperature 100C, running time 30 min; ASTM D 623-78). Blow out time was determined according to ASTM D 623-78 ~load 2 MPa, stroke 0.645 cm, frequency 30 Hz, start temperature 100C).
Abrasion was determined using a Zwick abrasion tester as volume loss per 40 m path traYelled (DIN 53516~.
Ageing of test specimens was carried out in a ventilated air oven at 70C or 100C for periods up to 14 days (ISO 188) SU BS~rITUlnE S HEE~r WO 93J09178 P~/EP92/01030 Examples 1 3 and Comparative Example A
- Examples 1-3 and Comparative Example A are formulations for truck tire treads. The components of each formulation are given in Table 1 and the physical and mechanical properties for different curing conditions are given in Tables 2a-2d. The heat buildup and permanent set are given for di~ferent curing conditions in Tables 3a-3b.
TABLE 1: Compound composition Ingredient _ _ _ 1 2 3 BR Buna C3 10 20 20 20 20 Carbon Black N-375 55 -55 55 55 Stearic Acid 2 2 2 2 ZnO RS 4 4 4 4 Ar.Oil Dutrex 729HP 8 8 8 8 Permanax 6PPD (R) 2 2 2 2 Perkacit CBS c 1.2 1.2 1.2 1.2 Sulphur 1.2 1.2 1.2 1.2 Coagent BCI-MX* _ _ 0.75 1 1.25 * BCI-MX = N,N'-m-xylene-bis-citraconic imide TABLE 2a: Physical and mechanical properties of the vulcanizates cured at 150C for tgo Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 69 69 68 69 Tensile strength MPa 25.6 26.2 23~9 26.1 Elongation ~ 533 535 502 545 Modulus 50% MPa 1.4 1.3 1.3 1.3 Modulus 100~ MPa 2.6 2.4 2.4 2.3 Modulus 300~ MPa 13.1 12.9 12.5 12.5 Rebound res~lience ~ 32 33 32 32 Abrasion mm3 87 100 __ _ _ SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 21?.23~7 TABLE 2b: Physical and mechanical properties of the vulcanizates cured at 150C for 60 min Test A 1 2 3 Density g/cm3 1 .12 1.12 1.12 1.12 Hardness IRHD 65 69 68 68 Tensile strength MPa 23.7 23. 7 22.5 23.6 Elongation % 534 536 498 506 Modulus 50% MPa 1.3 1.4 1.4 1.4 Modulus 100~ MPa 2. 2 2.3 2.4 2.3 Modulus 300% MPa 11.4 11.8 12.0 12.3 Rebound resilience %_ _ 30 32 31 32 TABLE 2c: Physical and mechanical properties of the vulcanizates cured at 170~C for tgo Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 68 66 67 67 Tensile strength MPa 25. 3 25.6 24.5 24.5 Elongation ~ 541 557 548 532 Modulus 50% MPa 1.3 1.3 1.2 1.2 Modulus 100% MPa 2.3 2.1 2.2 2.1 Modulus 300% MPa 12.4 11.6 11.8 11.7 Rebound resilience % 32 33 31 32 TABLE 2d: Physical and mechanical properties of the vulcanizates cured at 170C for 30 min Test A 1 2 3 Density g/cm3 1.12 1.12 1.12 1.12 Hardness IRHD 62 66 66 67 Tensile strength MPa 18.4 21.2 20.4 22.3 Elongation % 511 510 482 502 Modulus 50% MPa 1.1 1.2 1.2 1.3 Modulus 100% MPa 1. 7 2.0 2.1 2.2 Modulus 300% MPa 8.9 10.7 10.9 11.5 Rebound resilience % 29 30 31 31 SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 212~3~7 TABLE 3a: Heat build up and Permanent set of the vulcanizates cured at 170C for 30 min ITest I A 1 1 1 2 1 3 Heat build up C 51 34 33 34 Permanen~ set % 18.0 10.2 9.5 7.9 _ TABLE 3b: Hsat build up and Permanent set of the vulcanizates cured at 150C for 2 x tgo Test A 1 2 Heat build up C 48 34 32 34 Permanent set _ % 17.8 13.0 11.0 13.4 Example 4 and Comparative Example B
Example 4 and Comparative Example B are also formulations for truck tire treads. The components of each formulation are given in Table 4 and the physical and mechanical properties for different curing ccnditions are given in Tables 5a-5b. The heat buildup and permanent set are given for different curing conditions in Tables 6a-6b.
TABLE 4: Compound composition _ Recipes Ingredients ~ B 4 NR SMR 20 80.00 80.00 BR Buna CB 10 20.00 20.00 Carbon Black N-375 55.00 55.00 Stearic Acid 2 . 00 2 . 00 Zinc Oxide RS 4.00 4.00 Ar.Oil Dutrex 729HP 8.00 8.00 Permanax 6PPD 2.00 2.00 Perkacit CBS c 1.20 1.20 Sulphur 1.20 1.20 BCI-MX _ _ ___ _ 1.00 ~3UBSTITUTE SHEET
WO 93/09178 PCl'/EP92/01030 TABLE 5a: Mechanical properties of the vulcanization cured at 150C
for tgo times . _ Recipes Properties _ _ 4 Modulus, MPa 50~ 1.16 1.20 (1.06) (1.20) 100% (1 97) 2 08 300% 11 .52 11 .40 (9.37) (10.87) Tensile strength, 26.60 27.23 MPa (22 .20) (22 .87) Elongation,% 565 580 Tear strength, 94.5 100 kN/m (8~) (84) Rebound resilience, % (32) (32) Hardness, Shore A (54) (58) * Values in the parentheses designate the properties of the vulcantizates cured at 150C for 60 min.
SUBSTITUTE SHEET
WO 93/09178 PCI`/EP92/01030 212~47 TABLE 5b: Mechanical properties of the vulcanization cured at 170C
for tgo times Recipes Properties B 4 Modulus, MPa 50% 1.11 1.09 (0-93) (1.16) 100~ 1.79 1.7~
(1-~7) (1.90) 300% 9.73 10.06 (6.95) (10.19) Tensile strength, 24.50 25.63 MPa (16.49) t22.56) Elongation,~ 576 579 (522) (540) Tear strength, 110 105 kN/m (49) (69) Rebound resilience, % 57 58 ~ ss, Shore A (53) ¦ ~
* values in the parentheses designate the relevant properties of the vulcanizates cured at 170C for 30 min.
~UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 2122~47 Table 6a: Heat build up and permanent set properties (at 100C) of the vulcanizates cured at 150C for tgo*2 and 60 minutes Stro~e 4.45 mm, Load: 11 kg, Freqùency: 30Hz Start Temp.: 100C, Duration: 25 minutes UNAGED
Sample HBU,C Permanent Set,%
4 34 14.06 (27) (8.20) AGED, 7d/70C
B 55 18.08 (65) (25.39) 4 25 9.52 (27) (6.61) AGED, 14d/70C
B 56 20.47 (100) (Blown out) _ (227) (86 88) *values in the parentheses designate the properties of the . vulcanizates cured at 150C for 60 minutes ~UBSTITUTE SHEET
21223~7 Table 6b: Heat build up and permanent set properties (at 100C) of the vulcanizates cured at 170C for tgo*2 and 30 minutes Stroke: 4.45 mm, Load- 11 kg, Frequency: 30Hz Start Temp.: 100C, Duration: 25 minutes UNAGED
Sample HBU,C Permanent Set,%
~ 47 ~1.54 (52) (18.05) 4 34 1~.75 (~8) (7.43) AGED, 7d/70C
B 46 19.78 (83) (30.27) 4 27 11.02 (29~ (7-31) AGED,_14d/70C
B (112) (Blown out) 4 26 8.58 (30) (6.93) . _ *values in the parentheses designate the properties of the vulcanizates cured at 170C for 30 minutes Examples 5-7 and Comparative Examples C-D
Examples 5-7 and Comparative Examp~es C-D are formulations for off-the-road tire treads. The components of each formulation are given in Table 7 and the physical and mechanical properties for different curing conditions are given in Tables 8a-8d. The heat buildup and permanent set are given for different curing conditions in Tables 9-10.
SUBSTITUTE SHEET
WO 93/09178 PC~JEP92/01030 21223~
TABLE 7: Compound composition Ingredients _ _ C 5 6 7 D
Carbon Black N-220 40 40 40 40 40 Perkasil KS 404 Gr 20 20 20 20 20 Zinc Oxide RS 5 5 5 5 5 Steari c Acid 2 2 2 2 2 Ar.Oil Dutrex 729HP 3 3 3 3 3 Resin Cumar. 3 3 3 3 3 Si-69 3 3 3 3 3 Permanax TQ 1.5 1.5 1.5 1.5 1.5 Permanax 6PPD 2.5 2.5 2.5 2.5 2.5 Wax Sunolite 240 1 1 1 1 Perkacit CBS c 1.41 1.41 1.41 1.41 1.41 Sulfur 1.43 1.43 1.43 1.43 1.43 BCI-MP* 1.0 _ _ BCI-MX 1.0 BCI-ES2** 1.0 Duralink HTS __ 1.0 * BCI-MP = N,N'-m-phenylene-bis-citraconic imide ** BCI-ES2 = bis(2-citraconimidoethyl)disulfide TABLE 8a: Physical and mechanical properties of vulcanizates cured at 150C for tgo Test ~ 5 6 7 D
Density g/cm3 1.16 1.16 1.16 j 1.16 1.16 Hardness IRHD 70 74 70 68 67 Tensile strength MPa 23.7 23.1 23.8 23.5 22.5 Elongation % 507 494 522 495 503 Modulus 50% MPa 1.3 1.4 1.3 1.4 1.3 Modulus 100% MPa 2.6 2.7 2.5 2.6 2.3 Modulus 300% MPa 12.8 12.9 12.2 12.9 11.5 Rebound resilience % 29 28 29 30 31 Tear Strength kN/m 128 108 100 114 92 Compr.set 3 days 23C % 14 15 16 15 16 Compr.set 1 day 70C % 32 29 31 28 33 ~UBSTITUTE SHEET
212~3~ 7 TABLE 8b: Physical and mechanical properties of vulcanizates cured at 150C for 60 min Test _ 5 6 7 D .
Density ~ lcm3 1.16 1.161.16 1.16 1.16 Hardness IRHD 70 74 72 73 69 Tensile strength MPa 20.9 24.1 23.5 25.0 19.7 Elongation % 458 441 457 475 436 Modulus 50% MPa 1.4 1.7 1.6 1.7 1.3 Modulus 100% MPa 2.8 3.6 3.2 3.5 2.6 Modulus 300~ MPa 13.2 16.6 15.4 15.7 12.6 Rebound resilience % 26 29 30 28 28 Tear Strength kN/m 51.2 84.8 ~80.1 71.9 52.6 Compr.set 3 days 23C % 16 15 15 13 15 Compr.set 1 day 70C % l_ 24 23 22 22 24 TABLE 8c: Physical and mechanical properties of the vulcanizates cured at 170C for tgo Test C 5 6 7 D
Density g/cm' 1.16 1.161.16 1.16 1.16 Hardness IRHD 67 73 67 73 67 Tensile strength MPa 21.9 22.3 20.2 21.2 20.6 Fl ongation % 522 476 508 462 502 Modulus 50~ MPa 1.2 1.5 1.2 1.5 1.2 Modulus 100% MPa 2.2 2.7 2.1 2.6 2.1 Modulus 300~ MPa 11.0 12.5 10~2 12.5 10.4 Rebound resilience % 29 27 28 27 28 Tear Strength kN/m 96 65 - 76 67 82 , Compr.set 3 days 23C % 16 16 18 17 18 Compr.set 1 day 70C % 36 26 37 ~ 25 38 .
~UBSTITUTE SHEET
WO 93/09178 P~/EP92/01030 21~2347 TABLE 8d: Physical and mechanical properties of the vulcanizates cured at 170C for 30 min Test - C r 5 7 D
Density -- 97 cm3 i.16 1.16 1.16 1.161.16 Hardness IRHD 69 75 74 74 69 Tensile strength MPa 17.2 21.0 21.6 22.3 17.5 Elongation % 433 415 446 416 451 Modulus 50% MPa 1.3 1.6 1.5 1.7 103 Modulus 100% MPa 2.3 3.0 2.9 3.4 2.2 Modulus 300% MPa 10.8 14.4 13.4 15.6 10.6 Rebound resilience % 29 27 27 27 26 Tear Strength kN/m 75 75 60 59 27 Compr.set 3 days 23C % 20 15 17 16 19 Compr.set 1 day ?oC % 27 22 24 22 _ 27 TABLE 9: Dynamic properties of the vulcanizates oured at 150C for tgo*2 Compounds Control BCI-MP BCI-MX BCI-ES2 Dura.HTS
(C) (5) (6) (7) (D) PPHR -- 1.0 1.0 1.0 1.0 GOODRICH FLEXOMETER
Stroke: 4.45mm, Temp.: 100C, Frequency: 30 Hz, Duration: 25 min Heat Build-up,C 48 24 28 24 48 (46) (24) (~3) (25) (46) Set,% 23.1 7.2 11.7 8.9 22.5 t15.2) t5.2) (5.0) (6.3~ (17.6) Stroke- 6.45mm,_Temp.: 100C~ Frequency: 30Hz Blow out times 3.5 7.2 4.5 7.0 4.2 minutes (3~ (9.3) (8.0)~ (6.0) (4.0) Values in the parentheses are those for the vulcanizates at 150C for 60 minutes 3~
~3UBSTITUTE SHEET
WO 93/09178 PCI'/EP92/01030 212~3 17 TABLE 10: Dynamic properties of the vulcanizates cured at 170C for tgo*2 Compounds Control BCI-MP BCI-MX BCI-ES2 Dura.HTS
(C) (5) (6) (7) (D) PPHR -- 1,0 1.0 1.0 1.0 ~OODRICH FLEXOMETER
Stroke: 4.45mm, Temp.:_100C, Frequency: 30 Hz, Duration: 25 min Heat Build-up,C 49 24 34 24 49 (47) (24) (25) (27) (46) 10Set,% 27.9 2.9 17.0 5.5 29.6 (15.7) (4.8) ~5.8~ (6.0) (16.5) Stroke: 6.45 mm, Temp.: 100C, Frequency-. 30Hz B ow out times 4.0 10.0 4.5 10.0 3.5 minutes (4.0) (11.0) (8.0) (9.0)_ (3.75) Values in the parentheses designate the values obtained for the vulcanizates cured at 170C for 30 minutes Example 8 and Comparative Examples E-F
Example 8 and Comparative Examples E-F are formulations for conveyor belts. The components of each formulation are given in Table 11 and the physical and mechanical properties for different curing conditions are given in Tables 12a-12b. The heat buildup and permanent set are given for different curing conditions in Table 13.
TABLE 11: Compound composition Ingredient E F
Black N-330 45 45 45 Dutrex 729 H 4 4 4 ZnO RS 5 5 5 Stearic Acid 2 2 2 Sulfur 2.5 2,5 2.5 Perkacit CBS - 0.5 0.5 0.5 BCI-MX _ 1.0 HVA-2 _ _ __ 1.0 SUBSTITUTE SHEET
TABLE 12a: Mechanical properties (vulcanization 150C, tgo) Test E 8 F
S Hardness ~ I~HD 69 71 71 Tensile strength MPa 26.4 25.8 25.6 Elongation % ?75 465 470 Modulus 50% MPa 1.6 1.6 1.5 Modulus 100% MPa 3.4 3.1 3.2 Modulus 300% MPa 15.4 14.5 14.8 Rebound resilience % 38 37 37 Tear strength kN/m 73 91 81 Abrasion mm3 124 128 136 Compr.set 72h/23C % 9 10 10 Density g/cc 1.12 1.12 1.12 Compr.set 24h/70C % 23 24 23 Heat build up C 25 17 25 Permanent set % 8.6 5.8 _7.4 TABLE 12b: Mechanical properties (vulcanization 170C, 30 min) Test E 8 F
Hardness IRHD 59 68 64 Tensile strength MPa 14.1 19.8 17.0 Elongation % 415 415 445 Modulus 50% MPa 1.1 1.5 1.2 Modulus 100% MPa 1.9 2.8 2.2 Modulus 300% MPa 8.8 13.0 10.1 Rebound resilience % 32 35 33 Tear strength kN/m 20 29 21 . Abrasion mm3 ~ _ __ __ Compr.set 72h/23C % 20 11 19 Density g/cc 1.12 1.12 1.12 Compr.set 24h/70C % 30 19 27 Heat build up C 46 20 ~3 Permanent set % _16.4 3.2 9.3 . .
SUBSTITUTE SHEET
WO 93/09178 21 2 2 3 4 7 PCl'/EP92/01030 TABLE 13: Ageing properties (vulcanization 150C, tgo) Test E 8 F
Ageing medium air air air Ageing temperature C 100 100 100 Ageing time day(s) 3 3 3 Hardness IRHD 73 76 74 Change in Hardn. IRHD + 4 + 5 + 3 Tensile strength MPa 13.7 16.2 14.9 Change in T.S. % -48 -37 -42 Elongation % 230 225 230 Change in Elong. % -52 -52 -51 Modulus 50% MPa 2.3 2.5 2.4 Change in M50% % +44 +56 +50 Modulus 100% MPa 5.0 5.5 5.3 Change in M100~ % +47 +77 +66 ~3UBSTITlJTE SHEET
Claims (12)
1. A tire wherein at least one of the tread, steel-cord skim stock, sidewall and carcass portions contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 20-35°C.
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.5-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 20-35°C.
2. A tire wherein said tread portion contains a blend in accordance with claim 1 which contains 45-65 phr of carbon black.
3. A tire as claimed in any one of claims 1-2 wherein said steel-cord skim stock portion contains a blend in accordance with claim 1 containing 85-100 weight percent of natural rubber, polyisoprene or a mixture thereof and 0-15 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, and wherein said carbon black has an average particle size 10-30 nm.
4. A tire as claimed in any one of claims 1-3, wherein said carcass portion contains a blend in accordance with claim 1 containing 50-80 weight percent of natural rubber, polyisoprene, or a mixture thereof, 20-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, and 20-50 phr of carbon black having an average particle size of 45-70 nm.
5. A tire as claimed in any one of claims 1-4, wherein said sidewall portion contains a blend in accordance with claim 1 containing 40-60 phr of carbon black having an average particle size of 20-70 nm.
6. A tire as claimed in any one of claims l and 3-5 wherein said tread portion contains a blend in accordance with claim containing 80-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-20 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-50 phr carbon black having an average particle size of 10-30 nm., and 10-25 phr of silica having a surface area of 100-200 m2/g.
7. A tire as claimed in any one of claims 1-6 wherein said blend is cured at a temperature above 160°C to form said rubber composition.
8. A tire as claims in any one of claims 1-7 wherein said blend is cured for a time period of greater than t90.
9. A tire as claimed in any one of claims 7-8 wherein the heat buildup of said rubber composition is 20-30°C.
10. A belt which contains a rubber composition formed by curing a blend of at least:
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 10-25°C.
50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof, 20-65 phr, based on the total rubber content, of carbon black, 0.5-4.0 phr of activator, 1.0-10.0 phr of zinc oxide, 1.0-10.0 phr of sulfur or a sulfur donor, and 0.1-5.0 phr of curing accelerator, characterized in that said rubber composition has a heat buildup of 10-25°C.
11. A conveyor belt as claimed in claim 10 wherein said blend comprises 95-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-5 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof and 30-50 phr of carbon black having an average particle size of 20-40 nm.
12. A V-belt as claimed in claim 10 wherein said blend comprises 50-100 weight percent of natural rubber, polyisoprene or a mixture thereof, 0-50 weight percent of butadiene rubber, styrene-butadiene rubber or a mixture thereof and 30-65 phr of carbon black having an average particle size of 20-100 nm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP1991/002048 WO1992007904A1 (en) | 1990-10-29 | 1991-10-29 | Anti-reversion coagents for rubber vulcanization |
| EPPCT/EP91/02048 | 1991-10-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2122347A1 true CA2122347A1 (en) | 1993-05-13 |
Family
ID=8165618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002122347A Abandoned CA2122347A1 (en) | 1991-10-29 | 1992-05-07 | Tire and belt compositions |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0610197A1 (en) |
| JP (1) | JPH07500616A (en) |
| BR (1) | BR9206688A (en) |
| CA (1) | CA2122347A1 (en) |
| CZ (1) | CZ104794A3 (en) |
| FI (1) | FI941968A0 (en) |
| SK (1) | SK49694A3 (en) |
| WO (1) | WO1993009178A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9663640B2 (en) | 2013-12-19 | 2017-05-30 | Soucy Techno Inc. | Rubber compositions and uses thereof |
| US9840611B2 (en) | 2013-10-18 | 2017-12-12 | Soucy Techno Inc. | Rubber compositions and uses thereof |
| US9879131B2 (en) | 2012-08-31 | 2018-01-30 | Soucy Techno Inc. | Rubber compositions and uses thereof |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5503940A (en) * | 1994-10-24 | 1996-04-02 | The Goodyear Tire & Rubber Company | Elastomeric laminates containing a solventless elastomeric adhesive composition |
| US6186202B1 (en) | 1996-02-20 | 2001-02-13 | The Goodyear Tire & Rubber Company | Silica reinforced solventless elastomeric adhesive compositions |
| US6079468A (en) * | 1996-08-09 | 2000-06-27 | The Goodyear Tire & Rubber Company | Rubber article containing a bismaleimide and a bis benzothiazolydithio end capped compound |
| US5728757A (en) * | 1996-08-09 | 1998-03-17 | The Goodyear Tire & Rubber Company | Zinc salts of citraconamic acid and rubber compounds containing such salts |
| US5696188A (en) * | 1996-08-09 | 1997-12-09 | The Goodyear Tire & Rubber Company | Rubber compounds containing aryl bis citraconamic acids |
| JP4678909B2 (en) * | 2000-02-01 | 2011-04-27 | 住友ゴム工業株式会社 | Run flat tire |
| JP2001288298A (en) * | 2000-02-04 | 2001-10-16 | Bridgestone Corp | Rubber composition and pneumatic tire using the same |
| KR20030095080A (en) * | 2002-06-11 | 2003-12-18 | 금호타이어 주식회사 | Rubber composition for tire improved anti-fatigue property |
| KR20030095079A (en) * | 2002-06-11 | 2003-12-18 | 금호타이어 주식회사 | Rubber composition for tire improved anti-fatigue property |
| US20060111498A1 (en) * | 2004-11-23 | 2006-05-25 | The Goodyear Tire & Rubber Company | Rubber compound with hydrotalcite having increased blow-out resistance |
| JP2007169431A (en) | 2005-12-21 | 2007-07-05 | Sumitomo Rubber Ind Ltd | Rubber composition for side wall |
| US20070144644A1 (en) * | 2005-12-22 | 2007-06-28 | David John Zanzig | Pneumatic tire |
| WO2011158586A1 (en) * | 2010-06-15 | 2011-12-22 | バンドー化学株式会社 | Transmission belt |
| CN102911412A (en) * | 2012-11-01 | 2013-02-06 | 中国化工橡胶桂林有限公司 | All-steel radial tire sidewall rubber |
| JP6897144B2 (en) * | 2017-02-22 | 2021-06-30 | 横浜ゴム株式会社 | Rubber composition for conveyor belts, conveyor belts and belt conveyors |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4071496A (en) * | 1976-04-30 | 1978-01-31 | Phillips Petroleum Company | Carbon black for low-hysteresis rubber compositions |
| JPS5986641A (en) * | 1982-11-10 | 1984-05-18 | Tokai Carbon Co Ltd | Rubber composition |
-
1992
- 1992-05-07 SK SK496-94A patent/SK49694A3/en unknown
- 1992-05-07 CZ CZ941047A patent/CZ104794A3/en unknown
- 1992-05-07 EP EP92909444A patent/EP0610197A1/en not_active Withdrawn
- 1992-05-07 WO PCT/EP1992/001030 patent/WO1993009178A1/en not_active Application Discontinuation
- 1992-05-07 BR BR9206688A patent/BR9206688A/en not_active Application Discontinuation
- 1992-05-07 JP JP4508553A patent/JPH07500616A/en active Pending
- 1992-05-07 CA CA002122347A patent/CA2122347A1/en not_active Abandoned
-
1994
- 1994-04-28 FI FI941968A patent/FI941968A0/en unknown
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9879131B2 (en) | 2012-08-31 | 2018-01-30 | Soucy Techno Inc. | Rubber compositions and uses thereof |
| US9840611B2 (en) | 2013-10-18 | 2017-12-12 | Soucy Techno Inc. | Rubber compositions and uses thereof |
| US9663640B2 (en) | 2013-12-19 | 2017-05-30 | Soucy Techno Inc. | Rubber compositions and uses thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0610197A1 (en) | 1994-08-17 |
| WO1993009178A1 (en) | 1993-05-13 |
| FI941968A (en) | 1994-04-28 |
| JPH07500616A (en) | 1995-01-19 |
| BR9206688A (en) | 1995-10-24 |
| CZ104794A3 (en) | 1994-11-16 |
| SK49694A3 (en) | 1994-11-09 |
| FI941968A0 (en) | 1994-04-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |