EP1572799A1 - Method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized rubber compound as obtained with the method - Google Patents
Method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized rubber compound as obtained with the methodInfo
- Publication number
- EP1572799A1 EP1572799A1 EP03789645A EP03789645A EP1572799A1 EP 1572799 A1 EP1572799 A1 EP 1572799A1 EP 03789645 A EP03789645 A EP 03789645A EP 03789645 A EP03789645 A EP 03789645A EP 1572799 A1 EP1572799 A1 EP 1572799A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- support material
- rubber
- rubber compound
- compound
- zinc
- 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.)
- Withdrawn
Links
- 150000001875 compounds Chemical class 0.000 title claims abstract description 42
- 229920001971 elastomer Polymers 0.000 title claims abstract description 33
- 239000005060 rubber Substances 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000004636 vulcanized rubber Substances 0.000 title claims abstract description 6
- 238000004073 vulcanization Methods 0.000 claims abstract description 29
- 239000000463 material Substances 0.000 claims abstract description 25
- 239000012190 activator Substances 0.000 claims abstract description 19
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 14
- 239000011593 sulfur Substances 0.000 claims abstract description 14
- 238000005342 ion exchange Methods 0.000 claims abstract description 12
- 150000002500 ions Chemical class 0.000 claims abstract description 5
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 4
- 238000010438 heat treatment Methods 0.000 claims abstract description 4
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 4
- 229910021645 metal ion Inorganic materials 0.000 claims abstract description 4
- 229910052793 cadmium Inorganic materials 0.000 claims abstract description 3
- 239000004927 clay Substances 0.000 claims description 16
- 239000002253 acid Substances 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 claims description 6
- 229910000278 bentonite Inorganic materials 0.000 claims description 5
- 239000000440 bentonite Substances 0.000 claims description 5
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 claims description 5
- 229910052901 montmorillonite Inorganic materials 0.000 claims description 5
- 229910052625 palygorskite Inorganic materials 0.000 claims description 5
- 229910052902 vermiculite Inorganic materials 0.000 claims description 3
- 239000010455 vermiculite Substances 0.000 claims description 3
- 235000019354 vermiculite Nutrition 0.000 claims description 3
- 229910001510 metal chloride Inorganic materials 0.000 claims description 2
- 239000011701 zinc Substances 0.000 description 22
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 21
- 229910052725 zinc Inorganic materials 0.000 description 21
- 239000000243 solution Substances 0.000 description 15
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 14
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 10
- 239000002002 slurry Substances 0.000 description 7
- 239000011787 zinc oxide Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 229920000126 latex Polymers 0.000 description 6
- 239000004816 latex Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 239000011592 zinc chloride Substances 0.000 description 5
- 235000005074 zinc chloride Nutrition 0.000 description 5
- 239000004594 Masterbatch (MB) Substances 0.000 description 4
- -1 endellite Inorganic materials 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 3
- 235000021355 Stearic acid Nutrition 0.000 description 3
- HPTYUNKZVDYXLP-UHFFFAOYSA-N aluminum;trihydroxy(trihydroxysilyloxy)silane;hydrate Chemical compound O.[Al].[Al].O[Si](O)(O)O[Si](O)(O)O HPTYUNKZVDYXLP-UHFFFAOYSA-N 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 229910052621 halloysite Inorganic materials 0.000 description 3
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 3
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 3
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 3
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 239000008117 stearic acid Substances 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 2
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 2
- 229910052615 phyllosilicate Inorganic materials 0.000 description 2
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 description 2
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 244000043261 Hevea brasiliensis Species 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 239000006057 Non-nutritive feed additive Substances 0.000 description 1
- 239000004113 Sepiolite Substances 0.000 description 1
- ZOIORXHNWRGPMV-UHFFFAOYSA-N acetic acid;zinc Chemical compound [Zn].CC(O)=O.CC(O)=O ZOIORXHNWRGPMV-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910001583 allophane Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 239000010692 aromatic oil Substances 0.000 description 1
- 229960000892 attapulgite Drugs 0.000 description 1
- 229910001594 brammallite Inorganic materials 0.000 description 1
- VNSBYDPZHCQWNB-UHFFFAOYSA-N calcium;aluminum;dioxido(oxo)silane;sodium;hydrate Chemical compound O.[Na].[Al].[Ca+2].[O-][Si]([O-])=O VNSBYDPZHCQWNB-UHFFFAOYSA-N 0.000 description 1
- 150000004657 carbamic acid derivatives Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- PXKHGMGELZGJQE-ILBGXUMGSA-N chloramphenicol palmitate Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@@H](NC(=O)C(Cl)Cl)[C@H](O)C1=CC=C([N+]([O-])=O)C=C1 PXKHGMGELZGJQE-ILBGXUMGSA-N 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 229910001649 dickite Inorganic materials 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- FBPXRCLDUZKJLC-UHFFFAOYSA-N dioxosilane;oxomagnesium Chemical compound [Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FBPXRCLDUZKJLC-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000002357 guanidines Chemical class 0.000 description 1
- 230000009931 harmful effect Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 229910000271 hectorite Inorganic materials 0.000 description 1
- KWLMIXQRALPRBC-UHFFFAOYSA-L hectorite Chemical compound [Li+].[OH-].[OH-].[Na+].[Mg+2].O1[Si]2([O-])O[Si]1([O-])O[Si]([O-])(O1)O[Si]1([O-])O2 KWLMIXQRALPRBC-UHFFFAOYSA-L 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 229910052900 illite Inorganic materials 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229910052622 kaolinite Inorganic materials 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- IUJLOAKJZQBENM-UHFFFAOYSA-N n-(1,3-benzothiazol-2-ylsulfanyl)-2-methylpropan-2-amine Chemical compound C1=CC=C2SC(SNC(C)(C)C)=NC2=C1 IUJLOAKJZQBENM-UHFFFAOYSA-N 0.000 description 1
- 229920003052 natural elastomer Polymers 0.000 description 1
- 229920001194 natural rubber Polymers 0.000 description 1
- VGIBGUSAECPPNB-UHFFFAOYSA-L nonaaluminum;magnesium;tripotassium;1,3-dioxido-2,4,5-trioxa-1,3-disilabicyclo[1.1.1]pentane;iron(2+);oxygen(2-);fluoride;hydroxide Chemical compound [OH-].[O-2].[O-2].[O-2].[O-2].[O-2].[F-].[Mg+2].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[K+].[K+].[K+].[Fe+2].O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2 VGIBGUSAECPPNB-UHFFFAOYSA-L 0.000 description 1
- 229910000273 nontronite Inorganic materials 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920001195 polyisoprene Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000010734 process oil Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000275 saponite Inorganic materials 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052624 sepiolite Inorganic materials 0.000 description 1
- 235000019355 sepiolite Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- QAZLUNIWYYOJPC-UHFFFAOYSA-M sulfenamide Chemical compound [Cl-].COC1=C(C)C=[N+]2C3=NC4=CC=C(OC)C=C4N3SCC2=C1C QAZLUNIWYYOJPC-UHFFFAOYSA-M 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 150000003557 thiazoles Chemical class 0.000 description 1
- 239000012991 xanthate Substances 0.000 description 1
- 239000004246 zinc acetate Substances 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
- C08K9/00—Use of pretreated ingredients
- C08K9/02—Ingredients treated with inorganic substances
-
- 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
- C08K9/00—Use of pretreated ingredients
- C08K9/12—Adsorbed ingredients, e.g. ingredients on carriers
Definitions
- the invention relates to a method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized compound as obtained with the method according to the invention.
- Rubber compounds normally need to be vulcanized with sulfur or a sulfur-containing compound to ensure that they have the proper physical properties that are needed for the various applications.
- the vulcanization is usually carried out at elevated temperature and in the presence of a vulcanization accelerator because the vulcanization as such proceeds slowly.
- the vulcanization is normally carried out in the presence of a vulcanization catalyst or activator.
- zinc oxide is used as activator, often in combination with stearic acid in compounds containing sulfur.
- zinc oxide is used in the preparation of rubber compounds that are used in tires. In tire treads, zinc has the drawback that through wear of the car tires, tire grindings end up in the surface water.
- the invention relates to a method for vulcanizing a rubber compound, wherein the rubber compound, under heating, in the presence of sulfur or a sulfur-containing compound, and a vulcanization accelerator, is contacted with an activator comprising a support material loaded with Ba, Pd, Cd, Ca, Mg and/or Zn ions provided on the support material through an ion exchange process with a metal ion-containing solution.
- an activator comprising a support material loaded with Ba, Pd, Cd, Ca, Mg and/or Zn ions provided on the support material through an ion exchange process with a metal ion-containing solution.
- the support material is loaded with zinc ions.
- the rubber compounds that can be used according to the invention are generally known and can be selected from the group of polymers such as natural rubber, styrene butadiene rubber, polyisoprene rubber, nitrile butadiene rubber and ethylene propylene diene rubber.
- the support material of the activator is a clay, though not limited to the groups mentioned.
- Suitable clays can be selected from the group of the halloysite, illite, kaolinite, bentonite, phyllosilicate, and/or paly gorskite -like clays.
- Halloysite -like clays can be suitably selected from the group of allophane, endellite, halloysite, indianite, metahalloysite and schrotterrite.
- Suitable illite-like clays can be selected from the group of brammallite, bravaisite, glimmerton, hydromica and sercicite.
- Suitable ⁇ kaolinite-like clays can be selected from the group of anauxite or ionite, collyrite, dickite, ferrikaolinite, nacrite, neokaolin, metakaolin, metanacrite and severite.
- Suitable montmorillonite-like clays can be selected from the group of beidellite, bentonite, chloropal, erinite, ferrimontmorillonite, hectorite, metabentonite, montmorillonite, nontronite, otaylite and saponite.
- a suitable phyllosilicate-like clay is vermiculite.
- Paly gorskite -like clays can be suitably chosen from the group of attapulgite, calciopaly gorskite, lassalite, palygorskite, paramontmorillonite, parasepiolite and sepiolite.
- Such support materials can be suitably used in the method according to the invention because they contain (relatively) large amounts of exchangeable ions (Ca, Mg, Na).
- a clay is used from the group of bentonite and phyllosilicate.
- Particularly suitable supports herein are bentonite, montmorillonite and vermiculite.
- the metal loading of the activator is generally 0.1-30 wt.%, calculated on the support material. In a suitable embodiment, the metal loading is 1-15 wt.%, calculated on support material. Preferably, the metal loading is 3-7wt.%, and more preferably 4-6 wt.%, calculated on support material. In a suitable embodiment, the amount of activator is 0.1-20 wt.%, calculated on the rubber compound. Preferably, the amount of activator is 1-7 wt.%, calculated on the rubber compound, and more preferably the amount of activator is 2.5-5 wt.%, calculated on the rubber compound.
- the proposed activator allows the zinc content to be reduced by a factor of 20 if the activator is loaded with zinc, or allows the zinc to be actually replaced with other metals.
- the activator that is used according to the invention can be suitably prepared by subjecting the support material to an ion exchange process with a metal ion-containing solution.
- a zinc ion-containing solution is used.
- Suitable zinc ion-containing solutions can be selected from the group of zinc chloride, zinc nitrate and zinc acetate.
- use is made of a metal chloride solution and more preferably of a zinc chloride solution.
- the ion exchange process is carried out at a temperature of 15-30° C for 10-24 hours at a pH of 6-8.
- the ion exchange process is carried out at a temperature of 20-25° C for 12-18 hours, and at a pH of 6.5-7.5.
- the support material can be contacted under movement, for instance with shaking, with a metal ion- containing solution, preferably zinc chloride solution (for instance a 1M zinc chloride solution) for 2-8 hours.
- a metal ion- containing solution preferably zinc chloride solution (for instance a 1M zinc chloride solution) for 2-8 hours.
- the slurry obtained can be suitably dialyzed with, for instance, demineralized water until it is essentially anion- free.
- the thus obtained slurry can then be dried for 8-16 hours at a temperature of 65-70°C.
- the thus obtained support material can, if desired, be ground and screened, whereby a particle size of less than 38 microns can be obtained.
- the support material is treated with an acid before being subjected to the ion exchange process.
- Suitable acids can be selected from the group of hydrogen chloride and hydrogen sulfide acid. More preferably, as an acid, hydrogen chloride is used, for instance a solution of 20% hydrogen chloride.
- the treatment with acid is suitably carried out at a temperature of 15-30°C for 2-8 hours, and at a pH of 1-4.
- the treatment with acid is carried out at a temperature of 20-25°C for 3-5 hours, and at a pH of 1-2.
- the obtained slurry can be neutralized with an alkaline solution, for instance a NaOH solution, until it has acquired a pH of 6.5-7.
- the neutralized slurry can be suitably dialyzed, with, for instance, demineralized water, until the compound is substantially free of anions.
- the slurry can be dried, for 8-16 hours at a temperature of 65-70°C, after which the obtained support material can be ground and screened, whereby a particle size of less than 38 microns can be obtained.
- sulfur is used as vulcanizing agent.
- the amount of sulfur can be 0.5-3 wt.%, calculated on the rubber compound.
- the amount of sulfur is 1-2 wt.%, calculated on the rubber compound.
- a vulcanization accelerator is selected from the group of sulfenamides.
- the vulcanization accelerator can be present in an amount of 1-5 wt.%, calculated on the rubber compound. Preferably, the vulcanization accelerator is present in an amount of 2-4 wt.%, calculated on the rubber compound. It will be clear to the skilled person that the choice of the vulcanization accelerator will depend on the conditions under which the vulcanization process will be carried out.
- the vulcanization can be suitably carried out between 20-210°C, while for compression molding generally a temperature of 140-180°C is selected and for injection molding a temperature of 170-210°C.
- Continuous vulcanization can be carried out in a salt bath or hot air tunnels, with and without UHF with temperatures of 140°C to ca. 500°C.
- the invention further relates to rubber articles manufactured with a vulcanized rubber compound as obtained with the method according to the invention.
- Such rubber articles can be products such as tires for transport purposes such as car tires, airplane tires and tires for motorcycles, conveyor belts, (heating) hoses, driving belts, roller covering, electrical insulations, etc.
- the rubber articles can be sealing profiles for automobiles, radiator hoses, roof foil and membranes.
- the invention furthermore relates to a tire for transport purposes, and more preferably a car tire, that is manufactured from the vulcanized rubber compound as obtained with the method according to the invention.
- customary additives may be added to the rubber compound, such as black, plasticizers, clay, silica, pigments, antioxidants, antiozonants, delaying agents, and processing aids such as, for instance, fatty acids and process oils.
- a master batch was prepared, consisting of 100 parts of s-SBR Buna VSL 2525-0 (a solution SBR having a high content of polymer (98%); 50 parts N 375 (carbon black); and 5 parts of Enerflex 75 (aromatic oil).
- a vulcanization system was added to the master batch.
- the vulcanization system consisted of 2.5 parts of zinc clay; 2 parts of stearic acid; 1.75 parts of sulfur; and 1.50 parts of N-tert.butyl-benzothiazyl sulfenamide (accelerator), the parts being calculated on 100 parts of polymer (see also Table 1).
- the zinc clay was prepared by subjecting the acid-treated support material to an ion exchange process.
- the ion exchange was carried out with 12.5 grams of treated support material and 125 ml of a 1M zinc chloride solution, with shaking, at a temperature of 20°C, for 16 hours.
- the obtained slurry was dialyzed with demineralized water until it was essentially anion-free. The thus obtained slurry was then dried for 12 hours at a temperature of 70°C.
- the zinc clay was ground and screened, whereby a particle size of 63 microns at a maximum was obtained.
- the zinc clay comprised 4.5 wt.% of zinc, calculated on .Montmorillonite.
- the obtained mixture of the master batch and the vulcanization system was vulcanized for 30 minutes at a temperature of 160°C and a pressure of ca. 10 Bar.
- the obtained vulcanisate was then stored for 16 hours at 23°C, after which mechanical and physical properties of the vulcanisate were determined (see Table 2).
- Example 2 A vulcanization process as described in Example 1 was carried out, except that in the vulcanization system, instead of 2.5 parts of zinc clay, 5 parts of zinc oxide were used as zinc activator.
- the composition of the obtained compound of the master batch and the vulcanization system is shown in
- Tables 1 and 2 clearly show that surprisingly good and comparable mechanical and physical product properties can be obtained using the vulcanization process according to the invention, while the zinc concentration used has been reduced by as much as a factor of 20 (from 2.42% to 0.12%).
- Two aqueous dispersions were prepared in a small 0.25 liter-ball mill with ceramic balls of a diameter of 8 mm. The grinding time in the ball mill was 24 hours.
- the compositions of the prepared dispersions are shown in Table 3.
- the latex compounds were prepared according to the formulations in Table 4. The latex compounds were subsequently stored for five days at room temperature. Of the two qualities, small molded plates were manufactured in metal frames on a glass plate. The drying time was 24 hours. The plates were subsequently dried further for 1 hour at 70 °C. Of each rubber quality, two plates were vulcanized at 100°C for 1 hour. Of these plates, physicomechanical properties were determined, listed in Table 5.
- the measured physicomechanical properties demonstrate that there are no great differences between the latex qualities examined.
- the values for the tensile strengths are high, the moduli are comparable.
- the permanent deformation after storage at 70°C of the compound with zinc clay is of equal ) value as the compound with zinc oxide. This is an indication that the compound with zinc clay has reached a good degree of vulcanization after 1 hour of vulcanization at 100°C.
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- Chemical & Material Sciences (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 invention relates to a method for vulcanizing a rubber compound, wherein the rubber compound, under heating, in the presence of sulfur or a sulfur-containing compound, and a vulcanization accelerator, is contacted with an activator comprising a support material loaded with Ba, Pd, Cd, Ca, Mg and/or Zn ions provided on the support material through an ion exchange process with a metal ion-containing solution. The invention also relates to rubber articles manufactured from a vulcanized rubber compound as obtained with the method according to the invention.
Description
Title: Method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized rubber compound as obtained with the method
The invention relates to a method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized compound as obtained with the method according to the invention.
Rubber compounds normally need to be vulcanized with sulfur or a sulfur-containing compound to ensure that they have the proper physical properties that are needed for the various applications. The vulcanization is usually carried out at elevated temperature and in the presence of a vulcanization accelerator because the vulcanization as such proceeds slowly. To further improve the physical properties of the rubber vulcanisates to be obtained, the vulcanization is normally carried out in the presence of a vulcanization catalyst or activator. Typically, zinc oxide is used as activator, often in combination with stearic acid in compounds containing sulfur. As a most important application, zinc oxide is used in the preparation of rubber compounds that are used in tires. In tire treads, zinc has the drawback that through wear of the car tires, tire grindings end up in the surface water. Given the fact that zinc is a heavy metal unfortunately having a harmful effect on microorganisms, it will be clear that a reduction of the zinc concentration in tires for transport purposes, for instance car tires, would be very favorable to the environment. Surprisingly, it has now been found that rubber compounds can be vulcanized utilizing a specific activator that contains no zinc or substantially less zinc, which is highly favorable to the environment.
Accordingly, the invention relates to a method for vulcanizing a rubber compound, wherein the rubber compound, under heating, in the presence of sulfur or a sulfur-containing compound, and a vulcanization accelerator, is contacted with an activator comprising a support material
loaded with Ba, Pd, Cd, Ca, Mg and/or Zn ions provided on the support material through an ion exchange process with a metal ion-containing solution. Preferably, the support material is loaded with zinc ions.
The rubber compounds that can be used according to the invention are generally known and can be selected from the group of polymers such as natural rubber, styrene butadiene rubber, polyisoprene rubber, nitrile butadiene rubber and ethylene propylene diene rubber.
Preferably, the support material of the activator is a clay, though not limited to the groups mentioned. Suitable clays can be selected from the group of the halloysite, illite, kaolinite, bentonite, phyllosilicate, and/or paly gorskite -like clays. Halloysite -like clays can be suitably selected from the group of allophane, endellite, halloysite, indianite, metahalloysite and schrotterrite. Suitable illite-like clays can be selected from the group of brammallite, bravaisite, glimmerton, hydromica and sercicite. Suitable ■ kaolinite-like clays can be selected from the group of anauxite or ionite, collyrite, dickite, ferrikaolinite, nacrite, neokaolin, metakaolin, metanacrite and severite. Suitable montmorillonite-like clays can be selected from the group of beidellite, bentonite, chloropal, erinite, ferrimontmorillonite, hectorite, metabentonite, montmorillonite, nontronite, otaylite and saponite. A suitable phyllosilicate-like clay is vermiculite. Paly gorskite -like clays can be suitably chosen from the group of attapulgite, calciopaly gorskite, lassalite, palygorskite, paramontmorillonite, parasepiolite and sepiolite.
Such support materials can be suitably used in the method according to the invention because they contain (relatively) large amounts of exchangeable ions (Ca, Mg, Na).
Preferably, according to the invention, a clay is used from the group of bentonite and phyllosilicate. Particularly suitable supports herein are bentonite, montmorillonite and vermiculite.
These support materials are further described in U.S. Patent 3,902,886.
The metal loading of the activator is generally 0.1-30 wt.%, calculated on the support material. In a suitable embodiment, the metal loading is 1-15 wt.%, calculated on support material. Preferably, the metal loading is 3-7wt.%, and more preferably 4-6 wt.%, calculated on support material. In a suitable embodiment, the amount of activator is 0.1-20 wt.%, calculated on the rubber compound. Preferably, the amount of activator is 1-7 wt.%, calculated on the rubber compound, and more preferably the amount of activator is 2.5-5 wt.%, calculated on the rubber compound.
With respect to the conventional zinc oxide activator, the proposed activator allows the zinc content to be reduced by a factor of 20 if the activator is loaded with zinc, or allows the zinc to be actually replaced with other metals. The activator that is used according to the invention can be suitably prepared by subjecting the support material to an ion exchange process with a metal ion-containing solution. Preferably, a zinc ion- containing solution is used. Suitable zinc ion-containing solutions can be selected from the group of zinc chloride, zinc nitrate and zinc acetate. Preferably, in the ion exchange process, use is made of a metal chloride solution and more preferably of a zinc chloride solution.
In a suitable embodiment of the invention, the ion exchange process is carried out at a temperature of 15-30° C for 10-24 hours at a pH of 6-8. Preferably, the ion exchange process is carried out at a temperature of 20-25° C for 12-18 hours, and at a pH of 6.5-7.5. The support material can be contacted under movement, for instance with shaking, with a metal ion- containing solution, preferably zinc chloride solution (for instance a 1M zinc chloride solution) for 2-8 hours. Next, the slurry obtained can be suitably dialyzed with, for instance, demineralized water until it is essentially anion- free. The thus obtained slurry can then be dried for 8-16 hours at a temperature of 65-70°C. Next, the thus obtained support material can, if desired, be ground and screened, whereby a particle size of less than 38 microns can be obtained.
Preferably, the support material is treated with an acid before being subjected to the ion exchange process. Suitable acids can be selected from the group of hydrogen chloride and hydrogen sulfide acid. More preferably, as an acid, hydrogen chloride is used, for instance a solution of 20% hydrogen chloride.
The treatment with acid is suitably carried out at a temperature of 15-30°C for 2-8 hours, and at a pH of 1-4. Preferably, the treatment with acid is carried out at a temperature of 20-25°C for 3-5 hours, and at a pH of 1-2. Next, the obtained slurry can be neutralized with an alkaline solution, for instance a NaOH solution, until it has acquired a pH of 6.5-7. Next, the neutralized slurry can be suitably dialyzed, with, for instance, demineralized water, until the compound is substantially free of anions. Then, the slurry can be dried, for 8-16 hours at a temperature of 65-70°C, after which the obtained support material can be ground and screened, whereby a particle size of less than 38 microns can be obtained.
In the method according to the invention, preferably sulfur is used as vulcanizing agent. The amount of sulfur can be 0.5-3 wt.%, calculated on the rubber compound. Preferably, the amount of sulfur is 1-2 wt.%, calculated on the rubber compound. In the method according to the invention, use can be made of generally known vulcanization accelerators. Suitable vulcanization accelerators can be selected from the group of xanthates, carbamates, thiazoles, sulfenamides, thiurams, and guanidines, as described in Dutch patent specification 185670. Preferably, a vulcanization accelerator is selected from the group of sulfenamides.
The vulcanization accelerator can be present in an amount of 1-5 wt.%, calculated on the rubber compound. Preferably, the vulcanization accelerator is present in an amount of 2-4 wt.%, calculated on the rubber compound.
It will be clear to the skilled person that the choice of the vulcanization accelerator will depend on the conditions under which the vulcanization process will be carried out.
Depending on the type of accelerator and vulcanization temperature, the vulcanization can be suitably carried out between 20-210°C, while for compression molding generally a temperature of 140-180°C is selected and for injection molding a temperature of 170-210°C. Continuous vulcanization can be carried out in a salt bath or hot air tunnels, with and without UHF with temperatures of 140°C to ca. 500°C. The invention further relates to rubber articles manufactured with a vulcanized rubber compound as obtained with the method according to the invention. Such rubber articles can be products such as tires for transport purposes such as car tires, airplane tires and tires for motorcycles, conveyor belts, (heating) hoses, driving belts, roller covering, electrical insulations, etc. In addition, the rubber articles can be sealing profiles for automobiles, radiator hoses, roof foil and membranes. Preferably, the invention furthermore relates to a tire for transport purposes, and more preferably a car tire, that is manufactured from the vulcanized rubber compound as obtained with the method according to the invention. Further, customary additives may be added to the rubber compound, such as black, plasticizers, clay, silica, pigments, antioxidants, antiozonants, delaying agents, and processing aids such as, for instance, fatty acids and process oils.
Example 1
A master batch was prepared, consisting of 100 parts of s-SBR Buna VSL 2525-0 (a solution SBR having a high content of polymer (98%); 50 parts N 375 (carbon black); and 5 parts of Enerflex 75 (aromatic oil). Using a laboratory roll, a vulcanization system was added to the master batch. The vulcanization system consisted of 2.5 parts of zinc clay; 2 parts of stearic
acid; 1.75 parts of sulfur; and 1.50 parts of N-tert.butyl-benzothiazyl sulfenamide (accelerator), the parts being calculated on 100 parts of polymer (see also Table 1). Twenty-five grams of Montmorillonite were refluxed for 4 hours with an excess of HC1 (20%), and neutralized with a solution of 25% sodium hydroxide solution to pH 7. Next, the zinc clay was prepared by subjecting the acid-treated support material to an ion exchange process. The ion exchange was carried out with 12.5 grams of treated support material and 125 ml of a 1M zinc chloride solution, with shaking, at a temperature of 20°C, for 16 hours. Next, the obtained slurry was dialyzed with demineralized water until it was essentially anion-free. The thus obtained slurry was then dried for 12 hours at a temperature of 70°C. Next, the thus obtained zinc clay was ground and screened, whereby a particle size of 63 microns at a maximum was obtained. The zinc clay comprised 4.5 wt.% of zinc, calculated on .Montmorillonite. The obtained mixture of the master batch and the vulcanization system was vulcanized for 30 minutes at a temperature of 160°C and a pressure of ca. 10 Bar. The obtained vulcanisate was then stored for 16 hours at 23°C, after which mechanical and physical properties of the vulcanisate were determined (see Table 2).
Example 2
A vulcanization process as described in Example 1 was carried out, except that in the vulcanization system, instead of 2.5 parts of zinc clay, 5 parts of zinc oxide were used as zinc activator. The composition of the obtained compound of the master batch and the vulcanization system is shown in
Table 1. The mechanical and physical properties of the obtained vulcanisate are shown in Table 2.
Tables 1 and 2 clearly show that surprisingly good and comparable mechanical and physical product properties can be obtained using the
vulcanization process according to the invention, while the zinc concentration used has been reduced by as much as a factor of 20 (from 2.42% to 0.12%).
Table 1
Compound Example 2 Example 1 composition (parts) (parts) s-SBR VSL 2525 100 100
Carbon Black N375 50 50
Enerflex 75
Sulfur 1.75 1.75
TBBS * 1.5 1.5
Stearic acid
Zinc clay (activator) 2.5
ZnO (activator)
Zn-conc. (wt. %) 2.42 0.12
Table 2
Examples 3 and 4 (latex variants)
Two aqueous dispersions were prepared in a small 0.25 liter-ball mill with ceramic balls of a diameter of 8 mm. The grinding time in the ball mill was 24 hours. The compositions of the prepared dispersions are shown in Table 3. The latex compounds were prepared according to the formulations in Table 4. The latex compounds were subsequently stored for five days at room temperature. Of the two qualities, small molded plates were manufactured in metal frames on a glass plate. The drying time was 24 hours. The plates were subsequently dried further for 1 hour at 70 °C. Of each rubber quality, two plates were vulcanized at 100°C for 1 hour. Of these plates, physicomechanical properties were determined, listed in Table 5.
Table 3: Dispersions of zinc oxide and Zinc clay
Table 4: Latex compounds
Table 5: Physicomechanical properties of vulcanized latex plates
The measured physicomechanical properties demonstrate that there are no great differences between the latex qualities examined. The values for the tensile strengths are high, the moduli are comparable. The permanent deformation after storage at 70°C of the compound with zinc clay is of equal ) value as the compound with zinc oxide. This is an indication that the compound with zinc clay has reached a good degree of vulcanization after 1 hour of vulcanization at 100°C.
Claims
1. A method for vulcanizing a rubber compound, wherein the rubber compound, under heating, in the presence of sulfur or a sulfur -containing compound, and a vulcanization accelerator, is contacted with an activator comprising a support material loaded with Ba, Pd, Cd, Ca, Mg and/or Zn ions provided on the support material through an ion exchange process with a metal ion-containing solution.
2. A method according to claim 1, wherein the support material of the activator is a clay.
3. A method according to claim 1 or 2, wherein the support material is loaded with Zn ions.
4. A method according to 2 or 3, wherein the clay is selected from the group of the halloysite-, illite-, kaolinite-, montmorillonite-, bentonite-, phyllosilicate- and/or paly gorskite -like clays.
5. A method according to claim 4, wherein the clay is selected from the group of montmorillonite, vermiculite and/or bentonite.
6. A method according to any one of claims 1-5, wherein the metal content is 0.1-30 wt.%, calculated on the, support material.
7. A method according to claim 6, wherein the metal content is 1-15 wt.%, calculated on the support material.
8. A method according to any one of claims 1-7, wherein the support material is treated with an acid before being subjected to the ion exchange process.
9. A metho according to any one of claims 1-8, wherein the ion exchange process is carried out with a metal chloride solution.
10. A method according to any one of claims 1-9, wherein the vulcanization accelerator is selected from the group of sulfenamides.
11. A method according to any one of claims 1-10, wherein the vulcanization is carried out at a temperature of 20-210°C.
12. A rubber article manufactured from a vulcanized rubber compound as obtained with the method according to any one of claims 1-11.
13. A rubber article according to claim 12, which article is a tire for transportation purposes.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL1022146A NL1022146C2 (en) | 2002-12-11 | 2002-12-11 | Method for vulcanizing a rubber mixture, and rubber articles made from a vulcanized rubber mixture as obtained with the method. |
| NL1022146 | 2002-12-11 | ||
| PCT/NL2003/000880 WO2004052981A1 (en) | 2002-12-11 | 2003-12-11 | Method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized rubber compound as obtained with the method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1572799A1 true EP1572799A1 (en) | 2005-09-14 |
Family
ID=32501539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP03789645A Withdrawn EP1572799A1 (en) | 2002-12-11 | 2003-12-11 | Method for vulcanizing a rubber compound, and rubber articles manufactured from a vulcanized rubber compound as obtained with the method |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1572799A1 (en) |
| AU (1) | AU2003294184A1 (en) |
| NL (1) | NL1022146C2 (en) |
| WO (1) | WO2004052981A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2005201962B2 (en) * | 2005-05-10 | 2008-05-01 | Xuegang Chen | Process for producing micron-size, modified palygorskite as a Ziegler-Natta catalyst for production of polyethylene |
| US8288467B2 (en) | 2008-12-08 | 2012-10-16 | Nike, Inc. | Zinc ionomer rubber activator |
| FR2945815B1 (en) * | 2009-05-20 | 2011-07-01 | Michelin Soc Tech | RUBBER COMPOSITION COMPRISING AN ORGANOSILANE COUPLING AGENT |
| US8475584B1 (en) | 2009-10-12 | 2013-07-02 | Raymond Lee Nip | Zinc clays, zinc organoclays, methods for making the same, and compositions containing the same |
| ITMI20110974A1 (en) | 2011-05-30 | 2012-12-01 | Pirelli | HIGH-PERFORMANCE TIRE FOR VEHICLE WHEELS |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1299419B (en) * | 1961-01-11 | 1969-07-17 | Veith Pirelli Ag | Process for the production of vulcanizates from rubber mixtures containing silica |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2399947A (en) * | 1944-02-17 | 1946-05-07 | Vanderbilt Co R T | Compounding and vulcanization of synthetic rubber |
| JPS547279B2 (en) * | 1973-04-23 | 1979-04-05 | ||
| US4331706A (en) * | 1977-12-12 | 1982-05-25 | The Sherwin-Williams Company | Composite zinc oxide coating on an inert pigment core product and process |
-
2002
- 2002-12-11 NL NL1022146A patent/NL1022146C2/en not_active IP Right Cessation
-
2003
- 2003-12-11 EP EP03789645A patent/EP1572799A1/en not_active Withdrawn
- 2003-12-11 WO PCT/NL2003/000880 patent/WO2004052981A1/en not_active Ceased
- 2003-12-11 AU AU2003294184A patent/AU2003294184A1/en not_active Abandoned
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1299419B (en) * | 1961-01-11 | 1969-07-17 | Veith Pirelli Ag | Process for the production of vulcanizates from rubber mixtures containing silica |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2003294184A1 (en) | 2004-06-30 |
| WO2004052981A1 (en) | 2004-06-24 |
| NL1022146C2 (en) | 2004-06-15 |
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