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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/011—Crosslinking or vulcanising agents, e.g. accelerators
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
  • C08K5/37—Thiols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/548—Silicon-containing compounds containing sulfur
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L21/00—Compositions of unspecified rubbers
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
  • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure

Definitions

• the present invention relates to silica-containing rubber mixtures containing ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols, rubber vulcanizates prepared therefrom and their use.
• Silica-containing rubber compounds are important starting materials, for example for the production of tires with reduced rolling resistance. These perform less deformation work during unwinding and therefore lower fuel consumption. There is a great interest in further reducing this resistance due to the obligation to label tire rolling resistance decided in various countries, but this must not be done at the expense of wet-slip behavior, since the latter is safety-relevant.
• the initially prepared rubber mixture with the additives has a low flow viscosity (Mooney viscosity ML l + 4/100 ° C), so that it can be easily processed.
• further additives have been proposed, such as fatty acid esters, fatty acid salts or mineral oils.
• the said additives have the disadvantage that they increase the flowability, but at the same time reduce the stress values at greater elongation (eg 100% to 300%) or the hardness of the vulcanizates, so that the reinforcing effect of the filler suffers loss. Too low a hardness or stiffness of the vulcanizate but results in unsatisfactory handling of the tire, especially in curves.
• EP 1 134 253 describes polyether additives for silicic acid-containing rubber vulcanizates which do not show the above-mentioned disadvantage of reducing the voltage value. However, the skilled person requires high amounts (in the examples 4 phr or 8 phr are used). The teaching of EP 1 134 253 is directed to achieving an improved processing behavior, wherein the embodiments also have a low mixing viscosity and "
• EP 0 489 313 describes glycole-containing additives having good mechanical properties and improved hysteresis behavior. In comparison with the bis - [- 3- (triethoxysilyl) propyl] tetrasulfide according to DE-OS 2,255,577, however, the examples show no improvement in rolling resistance (tan ⁇ at 60 ° C). The wet skid behavior (tan d at low temperature) is practically unaffected. In addition, EP 0 489 313 contains no indication that the additives containing glycol functions improve the abrasion compared to the prior art.
• EP 1 000 968 uses a bis [3- (triethoxysilyl) -propyl] -tetrasulfide in combination with a special anti-reversion agent in SBR.
• the wet skid behavior (tan ⁇ at 0 ° C) and the rolling resistance (tan ⁇ at 60 ° C) are not compared to the prior art and the abrasion only slightly improved. The latter is still unfavorably high.
• EP 0 791 622 B1 describes a rubber composition with at least one diene-based elastomer, silica and carbon black as filler and tetrathiodipropanol polysulfide alone or together with bis (3-trialkoxysilylalkyl) polysulfide.
• the amount of tetrathiodipropanol polysulfide is larger than the amount of bis (3-trialkoxysilylalkyl) polysulfide, which is economically unfavorable.
• the addition of tetrathiodipropanol polysulfide appears to worsen the wet skid behavior. In addition, this mixture show very low tensile strength and high abrasion.
• the object of the present invention is to find additives and thus to provide new rubber mixtures which, while still having good flowability, can be converted into vulcanizates of increased hardness or stiffness which, when used in tires, improve rolling resistance, abrasion and wet skidding behavior.
• the invention therefore rubber mixtures, each containing at least one rubber, a sulfur-containing alkoxysilane, a silica-based filler, and a ro-mercapto-C2-C6-carboxylic acid ester of a polyhydric C 2 -C 6 alcohol, wherein at least 33%, preferably at least 50% and more preferably at least 66%, and most preferably at least 75%, but at least 2 of the hydroxyl groups of the C2-C6 polyhydric alcohol are esterified with ro-mercapto-C2-C6-carboxylic acid (s).
• the C2-C6 polyhydric alcohol has at most one hydroxy group per C atom.
• the polyhydric alcohol is ethylene glycol, diethylene glycol, triethylene glycol, trimethylolpropane, neopentyl glycol, glycerol or pentaerythritol, more preferably ethylene glycol, trimethylolpropane or pentaerythritol, and most preferably trimethylolpropane or pentaerythritol.
• ro-mercapto-C 2 -C 6 -carboxylic acid there may be used carboxylic acids which between the thiol and carboxyl group are a linear or branched, preferably a linear, C 1 -C 5 -alkanediyl unit, preferably a C 1 -C 3 -alkanediyl unit and very particularly preferably one C2 alkanediyl unit exhibit. It is also possible to esterify different ro-mercapto-C 2 -C 6 -carboxylic acids with the polyhydric alcohol. Particularly preferred embodiments of the present ro-mercapto-C 2 -C 6 -carboxylic acid esters of polyhydric alcohols are compounds of the formulas (I), (II) or (III)
• n 1, 2 or 3, preferably 1 or 2, more preferably 2.
• rubber mixtures which comprise one or more compounds of the formula (II) and / or (III), particularly preferably rubber mixtures which comprise at least one compound of the formula (III) and most preferably rubber mixtures which are trimethylolpropane tri-3-mercaptopropionate (CAS No .: 33007-83-9) and / or pentaerythritol tetra-3-mercaptopropionate (CAS No .: 7575-23-7).
• the rubber mixtures of the invention may be the ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols, also wholly or partly in the form of their salts, e.g. Lithium, sodium, potassium, calcium, strontium, barium and / or zinc salts, preferably in the form of zinc salts.
• their salts e.g. Lithium, sodium, potassium, calcium, strontium, barium and / or zinc salts, preferably in the form of zinc salts.
• the thiol functions of the ⁇ -mercapto-carboxylic acid esters of polyhydric alcohols may also be partly oxidized intra- or intermolecularly to disulfide groups, and in the case of intermolecular disulfide formation with analogous compounds and / or other thiols, oligomeric or polymeric structures may also be present.
• ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols in the claims therefore, such compounds are also included.
• ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols can also be used partially or completely absorbed on inert, organic or inorganic carriers.
• Preferred support materials are silicic acid, natural and synthetic silicates, alumina and / or Russian.
• the total content of the ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols in the rubber mixtures according to the invention is preferably 0.1 to 15 phr, particularly preferably 0.3 to 7 phr, very particularly preferably 0.5 to 3 phr and most preferably 0.7 to 1, 5 phr.
• the unit phr stands for parts by weight based on 100 parts by weight of rubber used in the rubber mixture.
• natural rubber and synthetic rubbers can be used.
• Preferred synthetic rubbers are, for example
• SBR styrene / butadiene copolymers having styrene contents of 1-60, preferably 20-50
• NBR - butadiene / acrylonitrile copolymers having acrylonitrile contents of 5-60, preferably
• EPDM - ethylene / propylene / diene copolymers and mixtures of two or more of these rubbers.
• the rubber mixtures according to the invention preferably contain at least one SBR rubber and at least one BR rubber, particularly preferably in the weight ratio SBR: BR of from 60:40 to 90:10.
• the rubber mixtures according to the invention also contain at least one NR rubber. More preferably, they have at least one SBR rubber, at least one BR rubber and at least one NR rubber, most preferably the weight ratio of SBR rubber to BR rubber to NR rubber 60 to 85: 10 to 35: 5 to 20.
• Sulfur-containing alkoxysilanes for the rubber mixtures according to the invention include, for example, bis (triethoxysilylpropyl) tetrasulfane (eg Si 69 from Evonik) and bis (triethoxysilylpropyl) disulfane (eg Si 75 from Evonik), 3- (triethoxysilyl) -1-propanethiol, polyether-functionalized mercapto silanes such as Evonik's Si 363, thioester-functionalized alkoxysilanes such as NXT or NXT Z from Momentive (formerly GE). It is also possible to use mixtures of the sulfur-containing alkoxysilanes.
• Liquid sulfur-containing alkoxysilanes can be applied to a support for better meterability and / or dispersibility (dry liquid).
• the active substance content is between 30 and 70 parts by weight, preferably 40 and 60 parts by weight per 100 parts by weight of dry liquid.
• the proportion of sulfur-containing alkoxysilanes in the rubber mixtures according to the invention is preferably 2 to 20 phr, particularly preferably 3 to 11 phr and very particularly preferably 5 to 8 phr, in each case calculated as 100% active ingredient.
• the amount of sulfur-containing alkoxysilane is greater than or equal to the total amount of ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols. More preferably, the weight ratio of sulfur-containing alkoxysilane to the total amount of ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols is from 1.5: 1 to 20: 1, more preferably from 3: 1 to 15: 1, and most preferably from 5: 1 to 10: 1.
• the rubber mixture according to the invention also contains one or more silicic acid-based fillers. Preferably, the following substances are used:
• Silica in particular precipitated silica or fumed silica, prepared, for example, by precipitation of solutions of silicates or flame hydrolysis of silicon halides with specific surface areas of 5-1000, preferably 20-400, m 2 / g (BET surface area) and with primary particle sizes of 10-400 nm.
• the silicas may also be present as mixed oxides with other metal oxides such as Al, Mg, Ca, Ba, Zn, Zr, Ti oxides.
• synthetic silicates such as aluminum silicate, alkaline earth silicates, such as magnesium or calcium silicate, with BET surface areas of 20-400 m 2 / g and primary particle size of 10-400 nm, natural silicates, such as kaolin and other naturally occurring silicas,
• Glass fibers also in forms of mats and strands
• the total content of fillers is preferably 10 to 200 phr, more preferably 50 to 160 phr and most preferably 60 to 120 phr.
• a particularly preferred embodiment is the combination of silica, carbon black and ⁇ -Mercaptocarbonklareestem of polyhydric alcohols.
• the rubber mixtures according to the invention also contain one or more crosslinkers.
• Sulfur-based or peroxidic crosslinkers are particularly suitable for this purpose.
• the peroxidic crosslinking agents used are preferably bis (2,4-dichlorobenzyl) peroxide, dibenzoyl peroxide, bis (4-chlorobenzoyl) peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcylohexane, tert-butyl perbenzoate, 2,2-bis (t-butylperoxy) butane, 4,4-di-tert-butyl peroxynonylvalerate, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert-butylcumyl peroxide, 1, 3-bis (t-butylperoxyisopropyl) benzene, di-tert-butyl peroxide and 2,5-dimethyl-2,5-di (tert-butylperoxy) -3-hexine.
• crosslinking yield can be increased.
• additives include triallyl isocyanurate, triallyl cyanurate, trimethylolpropane tri (meth) acrylate, triallyl trimellitate, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate Trimethylolpropane tri (meth) acrylate, zinc diacrylate, zinc dimethacrylate, 1, 2-polybutadiene or N, N'-m-phenylenedimaleimide suitable.
• sulfur can be used in elemental soluble or insoluble form or in the form of sulfur donors.
• Suitable sulfur donors are, for example, dimorpholyl disulfide (DTDM), 2-morpholinodithiobenzothiazole (MB SS), caprolactam disulfide, dipentamethylene thiuram tetrasulfide (DPTT) and tetramethylthiuram disulfide (TMTD).
• the crosslinking of the rubber mixtures according to the invention can be carried out with sulfur or sulfur donors alone, or together with vulcanization accelerators, for which e.g. Dithiocarbamate, thiurams, thiazoles, sulfenamides, xanthates, bi- or polycyclic amines, guanidine derivatives, dithiophosphates, caprolactams and thiourea derivatives are suitable. Furthermore, zinc diamine diisocyanate, hexamethylenetetramine, l, 3-bis (citraconimidomethyl) benzene and cyclic disulfanes are also suitable.
• the rubber mixtures according to the invention preferably contain sulfur-based crosslinkers and vulcanization accelerators.
• Sulfur, magnesium oxide and / or zinc oxide are particularly preferably used as crosslinking agents to which the known vulcanization accelerators, such as mercaptobenzothiazoles, thiazolesulfenamides, thiurams, thiocarbamates, guanidines, xanthates and thiophosphates are added.
• the known vulcanization accelerators such as mercaptobenzothiazoles, thiazolesulfenamides, thiurams, thiocarbamates, guanidines, xanthates and thiophosphates are added.
• the crosslinking agents and vulcanization accelerators are preferably used in amounts of from 0.1 to 10 phr, more preferably from 0.1 to 5 phr.
• the rubber mixtures according to the invention may comprise further rubber auxiliaries, such as reaction accelerators, anti-aging agents, heat stabilizers, light stabilizers, antioxidants, especially antiozonants, flame retardants, processing aids, impact modifiers, plasticizers, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retarders, metal oxides and activators , especially
• Triethanolamine polyethylene glycol, hexanetriol and anti-reversion agents.
• anti-aging agents are preferably alkylated phenols, styrenated phenol, hindered phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butyl butyl-4-ethylphenol, sterically hindered phenols containing ester groups, thioether-containing sterically hindered phenols, 2,2'-methylenebis (4-methyl-6-tert-butylphenol) (BPH) and sterically hindered thiobisphenols.
• BHT 2,6-di-tert-butylphenol
• BHT 2,6-di-tert-butyl-p-cresol
• BPH 2,2'-methylenebis (4-methyl-6-tert-butylphenol)
• thiobisphenols 2,2'-methylenebis (4-methyl-6-tert-butylphenol)
• aminic anti-aging agents e.g. B. mixtures of diaryl-p-phenylenediamines (DTPD), octylated
• Diphenylamine ODPA
• PAN phenyl-a-naphthylamine
• PBN phenyl-.beta.-naphthylamine
• phenylenediamine e.g. N-1, 3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N-1, 4-dimethylpentyl-N'-phenyl-p-, N-1,3-dimethyl-N'-phenyl-p-phenylenediamine.
• phenylenediamine (7PPD) N, N'-bis (l, 4-dimethylpentyl) -p-phenylenediamine (77PD).
• phosphites such as tris (nonylphenyl) phosphite, polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 2-mercaptobenzimidazole (MBI), methyl-2-mercaptobenzimidazole (MMBI), zinc methylmercaptobenzimidazole (ZMMBI) , which are usually used in combination with the above phenolic antioxidants.
• TMQ, MBI and MMBI are mainly used for NBR rubbers which are vulcanized peroxide.
• Ozone resistance may be reduced by antioxidants such as N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N, 4-dimethylpentyl-N'-phenyl-p-phenylenediamine (7PPD), ⁇ , ⁇ '- Bis- (1,4-dimethylpentyl) -p-phenylenediamine (77PD), enol ethers or cyclic acetals.
• Processing aids are said to act between the rubber particles and counteract frictional forces in mixing, plasticizing and deforming.
• the rubber mixtures according to the invention may contain all lubricants customary for the processing of plastics, such as, for example, hydrocarbons, such as oils, paraffins and PE waxes, fatty alcohols having 6 to 20 C atoms, Ketones, carboxylic acids such as fatty acids and montan acids, oxidized PE wax, metal salts of carboxylic acids, carboxylic acid amides and carboxylic acid esters, for example with the alcohols ethanol, fatty alcohols, glycerol, ethanediol, pentaerythritol and long-chain carboxylic acids as the acid component.
• plastics such as, for example, hydrocarbons, such as oils, paraffins and PE waxes, fatty alcohols having 6 to 20 C atoms, Ketones, carboxylic acids such as fatty acids and montan acids, oxidized PE wax, metal salts of carboxylic acids, carboxylic acid amides and carboxylic acid esters, for example with the alcohols
• the rubber composition of the present invention may also contain flame retardants.
• flame retardants for example, antimony trioxide, phosphoric acid esters, chloroparaffin, aluminum hydroxide, boron compounds, zinc compounds, molybdenum trioxide, ferrocene, calcium carbonate or magnesium carbonate are used for this purpose.
• other plastics Prior to crosslinking the rubber vulcanizate also other plastics can be added, which act, for example, as polymeric processing aids or impact modifiers.
• plastics are preferably selected from the group consisting of the homo- and copolymers based on ethylene, propylene, butadiene, styrene, vinyl acetate, vinyl chloride, glycidyl acrylate, glycidyl methacrylate, acrylates and methacrylates with alcohol components of branched or unbranched C 1 to C 4 alcohols, wherein Polyacrylates with identical or different alcohol radicals from the group of C 4 to Cg alcohols, in particular butanol, hexanol, octanol and 2-ethylhexanol, polymethyl methacrylate, methyl methacrylate-butyl acrylate copolymers, methyl methacrylate-butyl methacrylate copolymers, ethylene-vinyl acetate copolymers, chlorinated polyethylene, ethylene-propylene copolymers, ethylene-propylene-diene copolymers are particularly preferred.
• the rubber mixture according to the invention contains 0, 1 to 15 phr of the anti-reversion agent l, 6-bis (N, N-dibenzylthiocarbamoyldithio) hexane (CAS No .: 151900-44-6), whereby a further reduction of tan ⁇ ( 60 ° C), ie the rolling resistance is enabled.
• the rubber mixture according to the invention is typically characterized in that a vulcanizate heated therefrom at 170 ° C./t95 has a loss factor tan ⁇ at 60 ° C. of ⁇ 0.12.
• the rubber mixture according to the invention is preferably characterized in that a vulcanizate heated therefrom at 170 ° C./t95 has a loss factor tan ⁇ at 60 ° C. of ⁇ 0.12 and at the same time a hardness Shore A at 23 ° C. of> 64, in particular> 65 having.
• a vulcanization time of less than 2000 seconds and an abrasion of ⁇ 60, particularly preferably ⁇ 55, can also be achieved by the rubber mixtures according to the invention.
• Another object of the present invention is a process for the preparation of rubber mixtures, by mixing at least one rubber with at least one silicic acid-based filler, a sulfur-containing alkoxysilane and at least one ⁇ -Mercaptocarboxylic acid ester of a polyhydric alcohol.
• the abovementioned additional fillers, crosslinkers, vulcanization accelerators and rubber auxiliaries preferably in the amounts indicated above, can be added.
• the addition of the ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols is preferably carried out in the first part of the mixing process and the addition of one or more crosslinkers, in particular sulfur, and optionally vulcanization accelerators in a subsequent mixing stage.
• the temperature of the rubber composition is preferably 100 to 200 ° C, more preferably 120 ° C to 170 ° C.
• the shear rates in the mixture are 1 to 1000 sec -1 , preferably 1 to 100 sec -1 .
• the rubber mixture is cooled after the first mixing stage and the crosslinker and optionally crosslinking accelerator and / or additives are used to increase the crosslinking yield is added, in a subsequent mixing stage at ⁇ 140 ° C., preferably ⁇ 100 ° C.
• the addition of the ⁇ -mercaptocarboxylic acid esters of polyhydric alcohols in a subsequent mixing stage and at lower temperatures such as 40 to 100 ° C is also possible, for example together with sulfur and linking accelerator.
• the blends of the rubber with the filler and the ⁇ -mercaptocarboxylic acid ester of polyhydric alcohols can be carried out in conventional mixing equipment, such as rollers, internal mixers and mixing extruders.
• the optional addition of 1,6-bis (N, N-dibenzylthiocarbamoyldithio) hexane preferably takes place in the first stage of the multistage mixing process.
• Another object of the present invention is a process for vulcanization of the rubber mixtures of the invention, which is preferably carried out at melt temperatures of 100 to 200 ° C, more preferably at 130 to 180 ° C. In a preferred embodiment, the vulcanization takes place at a pressure of 10 to 200 bar.
• the present invention also encompasses rubber vulcanizates obtainable by vulcanization of the rubber mixtures according to the invention. These vulcanizates, especially when used in tires, have the advantages of low rolling resistance coupled with good wet skid resistance and low wear.
• the rubber vulcanizates according to the invention are suitable for the production of moldings having improved properties, for example for the production of cable sheaths, hoses, drive belts, conveyor belts, roller coverings, tires, shoe soles, sealing rings and damping elements.
• the rubber vulcanizate according to the invention can also be used for the production of foams. For this purpose, they are added to their chemical or physical blowing agent.
• Suitable chemically acting blowing agents are all substances known for this purpose, such as, for example, azodicarbonamide, p-toluenesulfonylhydrazide, 4,4'-oxybis (benzenesulfohydrazide), p-toluenesulfonyl semicarbazide, 5-phenyltetrazole, N, N'-dinitroso-pentamethylene - tetramine, zinc carbonate or sodium bicarbonate and mixtures containing these substances.
• carbon dioxide or halogenated hydrocarbons are suitable as physically active blowing agents.
• Another object of the present invention is the use of ro-mercapto-C2-C6-carboxylic acid ester of a polyhydric C 2 -C 6 -alcohol in which at least 33%, preferably at least 50% and more preferably at least 66% and most preferably at least 75% >
• at least 2 of the hydroxy groups of the C2-C6 polyhydric alcohol are esterified with ro-mercapto-C2-C6-carboxylic acid (s)
• the polyhydric alcohol is preferably ethylene glycol, diethylene glycol, triethylene glycol, trimethylolpropane, neopentyl glycol, glycerol or Pentaerythritol, more preferably ethylene glycol, trimethylolpropane or pentaerythritol, and most preferably trimethylolpropane or pentaerythritol, wherein the ro-mercapto-C 2 -C 6 -carboxylic acid este
• the viscosity can be determined directly from the force that rubbers (and rubber compounds) oppose to their processing.
• Mooney shear disk viscometer a fluted disk is enclosed with sample substance at the top and bottom and moved in a heated chamber at about two revolutions per minute. The required force is measured as torque and corresponds to the respective viscosity.
• the sample is usually preheated to 100 ° C for one minute; The measurement takes another 4 minutes, keeping the temperature constant.
• the viscosity is given together with the respective test conditions, for example ML (1 + 4) 100 ° C. (Mooney viscosity, large rotor, preheating time and test time in minutes, test temperature).
• Scorching behavior (scorching time t 5):
• the scorch behavior of a mixture can also be measured.
• the chosen temperature was 130 ° C.
• the rotor will run until the torque value passes to a minimum of 5 Mooney units relative to
• a scorching time of more than 300 seconds is usually advantageous, which, taking account of processing safety and expenditure of time, should be less than 1000 seconds and in special cases less than 500 seconds.
• the cure progression on the MDR (moving rheometer) and its analytical data are measured on a Monsanto rheometer MDR 2000 according to ASTM D5289-95.
• As a vulcanization time the time is determined at which 95% of the rubber is crosslinked.
• the chosen temperature was 170 ° C.
• the tensile test serves directly to determine the load limits of an elastomer and is carried out according to DIN 53504.
• Dynamic test methods are used to characterize the deformation behavior of elastomers under periodically changed loads. An externally applied strain alters the conformation of the polymer chain.
• the loss factor tan ⁇ is determined indirectly via the ratio between loss modulus G "and storage modulus G. The loss factor tan ⁇ (0 ° C.) gives a first indication of the wet skid behavior and should be as high as possible (good wet grip), whereas tan ⁇ contributes 60 to 70 ° C associated with the rolling resistance and should be as low as possible.
• the abrasion gives an indication of the wear and thus on the life of a product.
• the abrasion was determined according to DIN 53516. For economic and ecological reasons, a low value is desirable.
• the water and glycol di (3-mercaptopropionate) were charged. Then, the NaOH solution was added dropwise under nitrogen transfer at a temperature of 0- 5 ° C in about 30min and stirred for a further 30 min.
• the ZnSO pLsg. added dropwise and stirred for 30 min.
• the Zn salt was filtered with suction through a D4 frit and washed with 500 ml portions of water to a conductivity of ⁇ 0.3 milli-Siemens.
• the product was dried at 35 ° C in a vacuum drying oven.
• Apparatus 1000ml four-necked flask with thermometer, dropping funnel with pressure compensation,
• Reflux cooler with gas discharge approach bubble counter
• the water and pentaerythritol-tetra (3-mercaptopropionate) were placed in the nitrogen-purged apparatus. Then the ZnSO pLsg. added dropwise under nitrogen transfer at a temperature of 0-5 ° C in about 60min and stirred for 30min.
• the mixing piece was picked up by a downstream mill and formed into a plate and stored for 24 hours at room temperature.
• the processing temperatures were below 60 ° C.
• the rubber mixtures were then vulcanized at 170 ° C.
• the properties of the rubber preparations prepared and their vulcanizates are given in Table 2.
• the tested vulcanizates show in comparison to the reference a very good wet skid behavior (tan ⁇ at 0 ° C> 0.45) and excellent rolling resistance (tan ⁇ at 60 ° C ⁇ 0.12) in combination with extremely favorable abrasion values ( ⁇ 60 mm 3 ).
• the vulcanizates of the rubber formulations 4-6 containing zinc salts of the ro-mercapto-C 2 -C 6 -carboxylic acid esters of polyhydric C 2 -C 6 -alcohols gave similar results to the rubber formulations 1 - 3.

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• Mechanical Engineering (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 2012
  • 2012-07-09 EP EP12175550.8A patent/EP2684912A1/de not_active Withdrawn
• 2013
  • 2013-07-09 RU RU2015103991A patent/RU2641128C2/ru not_active IP Right Cessation
  • 2013-07-09 EP EP13735019.5A patent/EP2870195B1/de not_active Not-in-force
  • 2013-07-09 US US14/411,666 patent/US9493639B2/en not_active Expired - Fee Related
  • 2013-07-09 WO PCT/EP2013/064493 patent/WO2014009373A1/de not_active Ceased
  • 2013-07-09 JP JP2015520958A patent/JP6192720B2/ja not_active Expired - Fee Related
  • 2013-07-09 KR KR1020157000195A patent/KR20150036002A/ko not_active Withdrawn
  • 2013-07-09 BR BR112015000589A patent/BR112015000589A2/pt not_active Application Discontinuation
  • 2013-07-09 CN CN201380036174.7A patent/CN104428357B/zh not_active Expired - Fee Related
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