TW201311794A - Silica-containing rubber mixtures with sulphur-containing additives - Google Patents

Abstract

The present invention relates to silica-containing rubber mixture produced from at least one rubber, from a sulphur-containing alkoxysilane, from a crosslinking agent, from a filler, and optionally from further rubber auxiliaries, where the said mixture comprises from 0.1 to 15 parts by weight, based on 100 parts by weight of rubber used, of a silicon-free polysulphide additive of the formula (I) A-S-(S)x-S-Y-S-(S)x-S-A (I) where x is 0, 1 or 2, Y is an optionally substituted or heteroatom-containing aliphatic, cycloaliphatic or aromatic group and A is a moiety where R1 to R2 are identical or different and are hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or a group -CH2-OR5, -CH2-CH2-OR5, -NHR5, -COR5, -COOR5, -CH2COOR5, where R5 = hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or C1-C6-acyl, or A is a moiety in which R1 and R2 are identical or different and are hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or a group -CH2-OR5, -CH2-CH2-OR5, -NHR5, -COR5, -COOR5, -CH2COOR5, where R5 = hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or C1-C6-acyl, or A is a moiety in which R1 to R2 are identical or different and hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or a group -CH2-OR5, -CH2-CH2-OR5, -NHR5, -COR5, -COOR5, -CH2COOR5, where R5 = hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or C1-C6-acyl, and R6 is hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or a group -CH2-OR5, -CH2-CH2-OR5, -NHR5, -COR5, -COOR5, -CH2COOR5, where R5 = hydrogen, C1-C6-alkyl, C5-C6-cycloalkyl, C6-C10-aryl or C1-C6-acyl and y is 0, 1 or 2.

Description

Vermiculite-containing rubber mixture with sulfur-containing additives (2)

The present invention relates to a vermiculite-containing rubber mixture comprising sulfur-containing additives and to the use of such mixtures and to vulcanized rubber produced therefrom.

A variety of suggested solutions have been devised for producing tires with reduced rolling resistance. Certain polysulfide decanes have been described as reinforcing additives for vulcanized rubber containing vermiculite, as described in DE-A 2 255 577 and 4 435 311, EP-A1 0 0 670 347 and also US-A-4 709 065. However, the disadvantage of using the polysulfide decane described in these documents as a reinforcing additive for vulcanized rubber containing vermiculite requires a relatively large amount of expensive polysulfide decane to achieve acceptable processability and hardness. Not satisfactory.

Additional additional materials, such as fatty acid esters, fatty acid salts, or mineral oils have been proposed for improving the processability of the vermiculite-containing rubber mixture. The additional materials mentioned have the disadvantage of increasing the flowability of the vulcanized rubber while reducing the modulus at relatively high elongations (for example from 100% to 300%), or also hardness, And thus the reinforcing effect of the filler is impaired. The insufficient hardness or stiffness of the vulcanized rubber results in unsatisfactory tire running performance, especially when bent.

Increasing the amount added to the reinforcing filler increases the vulcanized rubber The hardness of the glue, but the higher viscosity of the mixture is detrimental to workability and it is suitable for the reduction in the amount of plasticizing oil.

EP 1 134 253 describes polyether additives for vermiculite-containing vulcanizates which do not exhibit the above-mentioned disadvantages of reduced modulus. However, those skilled in the art require the use of a product based on 8% by weight of the rubber in order to increase its Shore A hardness value by 3 units. A low modulus at 300% elongation is disadvantageous.

EP 0 489 313 describes additives which have good mechanical properties and have improved hysteresis properties. However, these examples reveal only slight or no increase in Shore A hardness compared to the conventional technique of bis[3-(triethoxyindolyl)propyl]tetrasulfide in Offenlegungsschrift 2 255 577, Germany. And thus there is no improvement in the mutual reaction between the polymer and the filler.

Furthermore EP 1 000 968 uses in the SBR a bis[3-(triethoxyindolyl)propyl]tetrasulfide in combination with a special reversion stabilizer, wherein the 300 modulus values are very low and therefore It is not suitable.

EP 0 791 622 B1 describes a rubber composition comprising at least one diene-based elastomer, consisting of vermiculite and carbon black, and a vermiculite coupling agent selected from the group consisting of

(i) a tetrathiodipropanol polysulfide mixture or

(ii) tetrathiodipropanol polysulfide and bis(3-trialkoxydecylalkyl)

A combination of polysulfides. In particular, the tetrathiodipropanol polysulfide The amount is significantly greater than the amount of bis(3-trialkoxydecylalkyl) polysulfide, and this is not economically advantageous because the tetrathiodipropanol polysulfide is relatively expensive. Furthermore, the mixture exhibits very low tensile strength values. It can be inferred that the mixture is too soft (as evidenced by the measured Shore A hardness), as reflected in the relatively poor running performance of the tire and also on the shortened life.

One of the objects of the present invention is to provide a rubber compound comprising a special combination of additional materials which does not impair the flowability of the rubber mixture and which provides a vulcanized rubber having good properties produced therefrom, particularly in the case of tires. In terms of rolling resistance, abrasion, and wet grip, while at the same time significantly increasing the hardness and rigidity of the vulcanized rubber, there is a possibility of improving the running performance of the tire.

Surprisingly, it has now been found that in combination with sulfur-containing alkoxydecane, certain sulfur-containing additives do not adversely affect the flowability of the rubber mixture and produce good kinetic properties with significantly increased hardness/ Stiffness and especially the vulcanized rubber with less wear.

This synergistic effect is believed to result from an improved interaction between the polymer and the filler.

The invention therefore provides from at least one rubber, from a sulfur-containing alkoxysilane, from a crosslinking agent, from a filler, and optionally from another rubber adjuvant, and from at least one of the following formula (I) Rubber mixture AS-(S) _x -SYS-(S) _x -SA (I) produced from flawless sulfur-containing additives

Wherein x is 0, 1, or 2, and Y is an optionally substituted or heteroatom-containing aliphatic, cycloaliphatic, or aromatic group, and the moiety below A Wherein R ¹ to R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, or a moiety below A Wherein R ¹ and R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C _{a 6} -cycloalkyl group, a C ₆ -C ₁₀ -aryl group or a C ₁ -C ₆ -fluorenyl group, or a moiety below the A system

Wherein R ¹ and R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, and R ⁶ is hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C _6- C ₁₀ -aryl or group -CH ₂ -OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen , C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, and y is 0, 1, or 2.

Particularly preferred is one of the following Y group:

Where a = from 2 to 12

Which from a=2 to 12

Where b = from 1 to 4

Where b = from 1 to 4.

Very particularly preferred is Y-(CH ₂ ) ₆ -.

An innocent sulfur-containing additive, a polysulfide additive, a non-sulfur polysulfide additive, and a non-sulfur polysulfide additive of formula (I), and all of the compounds listed therein Chemical formula, used as a synonym.

It is preferred to use at least one compound of the formulae (II) and (III) as a polysulfide additive.

It is preferred to use at least one compound of the formulae (IV), (IVa), (V), (Va), (VI) and (VIa) as a polysulfide additive.

(IVa)

It is preferred to use at least one compound of the formula (VII) as a polysulfide additive.

It is preferred to use at least one compound of the formula (VIII) as a polysulfide additive.

Wherein R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are each independently hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or a group -CH ₂ -OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -CH ₂ -COOR ⁵ , -CH ₂ -CH ₂ -COOR ⁵ , and R ⁸ and R ⁹ , and R ¹⁰ and R ¹¹ and The respective nitrogen atoms may together form a ring and R ⁵ is as defined above, and at least one of the R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ moieties includes one or more oxygen atoms.

It is preferred to use at least one compound of the formula (IX) as a polysulfide additive.

It is preferred to use at least one compound of the formula (X) as a polysulfide additive.

It is preferred to use at least one compound of the formula (XI) as a polysulfide additive.

The examples list other preferred polysulfide additives.

The vermiculite-containing rubber mixture package according to the present invention preferably comprises at least one SBR rubber and at least one BR rubber.

Preferably, the SBR:BR weight ratio of the at least one SBR rubber and the at least one BR rubber is from 60:40 to 90:10.

It preferably also includes at least one NR rubber.

It preferably comprises a ratio of at least one SBR rubber and at least one BR rubber and at least one NR rubber of at least 60 and up to 85 percent by weight of SBR based on rubber, and at least 10 and up to 35 percent by weight of BR based on rubber And NR based on at least 5 and up to 20 percent by weight of the rubber.

Synthetic rubbers are also suitable for use with natural rubber for the production of rubber mixtures according to the invention and vulcanized rubbers according to the invention. A preferred synthetic rubber is exemplified in W. Hofmann, Kautschuktechnologie [Rubber technology], Genter-Verlag, Stuttgart 1980 is described.

These include, inter alia: BR-polybutadiene, ABR-butadiene/C ₁ -C ₄ -alkyl acrylate copolymer

CR polychloroprene

IR-polyisoprene

SBR-styrene/butadiene copolymer, wherein the styrene content is from 1% to 60% by weight, preferably from 20% to 50% by weight.

IIR-isobutylene/isoprene copolymer

NBR-butadiene/acrylonitrile copolymer, wherein the acrylonitrile content is from 5% to 60% by weight, preferably from 10% to 50% by weight

HNBR - partially hydrogenated or fully hydrogenated NBR rubber

EPDM-ethylene/propylene/diene copolymer and mixtures of such rubbers.

The vermiculite-containing rubber mixture preferably further comprises from 0.3 to 7 parts by weight, based on 100 parts by weight of the rubber used, of one or more non-sulfur polysulfide additives of any formula having the formula (I) or derived therefrom , as listed in the scope of the patent application (hereinafter referred to as innocent polysulfide additive).

The amount of the sulfur-containing alkoxysilane is preferably greater than or equal to the amount of the non-sulfur polysulfide additive.

The sulfur-containing alkoxysilane is preferably used in a weight ratio of from 1.5:1 to 20:1, particularly from 5:1 to 15:1, relative to the non-twist polysulfide additive.

The rubber mixture according to the present invention preferably comprises from 0.5 to 5 parts by weight of the non-twisted polysulfide additive based on 100 parts by weight of the rubber used.

The invention further provides a vulcanizate which can be produced from a rubber mixture according to the invention.

The invention further provides a method for producing a filled vulcanized rubber, characterized in that at least one rubber is mixed with

Ii) from 10% to 150% by weight, preferably from 30% to 120% by weight of the filler of the rubber (i), and

Iii) an antimony-free polysulfide additive based on 0.1% to 15% by weight, preferably from 0.3% to 7% by weight of the rubber (i)

Wherein the composition has a temperature of at least 120 ° C and a shear rate of from 1 to 1000 seconds (exp. -1), preferably from 1 to 100 seconds (exp. -1), and then the mixture is added Additional vulcanization chemicals are then conventionally vulcanized.

The ruthenium-free polysulfide additive according to the present invention is preferably added to the first part of the mixing process when the temperature of the composition is from 100 ° C to 200 ° C and the shear rate is as mentioned above, but It can also be added later at a lower temperature (from 40 ° C to 100 ° C), for example with sulfur and a promoter.

The innocuous polysulfide additives may be added to the mixing process in pure form or otherwise adsorbed on an inert, inorganic or organic carrier. Preferred support materials are vermiculite, natural or synthetic silicates, aluminas and/or carbon blacks.

For the purposes of the present invention, the vermiculite-containing fillers which can be used in the rubber mixtures and vulcanized rubbers according to the invention include the following fillers:

- Fine-grained vermiculite, for example by precipitation from a solution of a phthalate or by flame hydrolysis of cesium halide, having a mass of from 5 to 1000 m ² /g, preferably from 20 to 400 m ² /g Specific surface area (BET surface area) and has a primary particle size of from 10 to 400 nm. Optionally, the vermiculite may also be in the form of a mixed oxide with other metal oxides such as oxides of Al, Mg, Ca, Ba, Zn, Zr, Ti.

- Synthetic silicates such as aluminum citrate, alkaline earth metal silicates such as magnesium citrate or calcium citrate, having a BET specific surface area from 20 to 400 m ² /g and a primary from 10 to 400 nm Particle size

- Natural citrates such as kaolin and other naturally occurring vermiculite,

- Glass fibres as well as glass fibre products (felts, strands) or glass microbeads.

Other fillers that can be used are carbon black. The carbon black used herein is exemplified by a lamp black method, a furnace black method or a gas black method, and has a BET surface area of from 20 to 200 m ² /g, such as SAF, ISAF, IISAF, HAF, FEF or GPF. Carbon black.

These innocuous polysulfide additives are preferably used in an amount of from 0.3% to 7% based on the rubber in the rubber mixtures according to the invention.

A particularly preferred variant consists of a combination of vermiculite, carbon black, and an antimony-free polysulfide additive. The ratio of vermiculite to carbon black in this combination can vary within any desired limits. For the purpose of tire technology, it is preferred that the ratio of vermiculite: carbon black is from 20:1 to 1.5:1.

The sulfur-containing decane which can be used in the vulcanized rubber according to the present invention is preferably bis(triethoxysilylpropyl)tetrasulfane and the corresponding disulfane and 3- Triethoxymercapto-1-propanethiol or decane, such as Si 363 from Evonik, Germany, or decane NXT or NXT from Momentive (formerly US GE), where the alkoxy moiety is methoxy or The ethoxy group, wherein the amount used is 2 to 20 parts by weight, preferably 3 to 11 parts by weight, calculated in each case as a 100% strength active component and based on 100 parts by weight of rubber. However, it is also possible to use a mixture made of the sulfur-containing decane. The liquid sulfur-containing decane has been adsorbed on a carrier in order to improve the convenience of metering and/or the convenience of dispersion (dry liquid). The content of the active ingredient is from 30 to 70 parts by weight, preferably from 40 to 60 parts by weight, per 100 parts by weight of the dry liquid.

The vulcanized rubber according to the present invention may contain other rubber auxiliaries such as reaction accelerators, antioxidants, heat stabilizers, light stabilizers, antiozonants, processing aids, plasticizers, tackifiers, foaming agents, dyes, Pigments, waxes, bulking agents, organic acids, retarders, metal oxides, There are also activators such as triethanolamine, polyethylene glycol, hexanetriol, which are known in the rubber industry.

The amounts used for the rubber auxiliaries are conventional and depend, inter alia, on the intended purpose of the vulcanizates. The conventional amount based on rubber is from 0.1% to 30% by weight.

The following are used as crosslinking agents: peroxides, sulfur, magnesium oxide, zinc oxide, and known vulcanization accelerators may also be added thereto, for example, mercaptobenzothiazole, sulfenamide, Thiurams, thiourethanes, guanidines, xanthates, and phosphorothioates. Preferred is sulfur.

The crosslinking agent and the vulcanization accelerator are used in an amount of from about 0.1% to 10% by weight, based on the rubber, preferably from 0.1% to 5% by weight.

As mentioned above, it is advantageous to add an antioxidant to the rubber mixture in order to counteract the effects of heat and oxygen. Suitable phenolic antioxidants are alkylated phenols, styrenated phenols, sterically hindered phenols such as 2,6-di-tributyl phenol, 2,6-di-tri-butyl P-cresol (BHT), 2,6-ditri-butyl-4-ethylphenol, sterically hindered phenols containing ester groups, sterically hindered phenols containing thioethers, 2,2'- Methylene bis(4-methyl-6-tertiary butyl phenol) (BPH) and sterically hindered thiobisphenols.

If the fading of the rubber is not important, an aminic antioxidant such as diaryl p-phenylenediamine (DTPD), octylated diphenylamine (ODPA), phenyl-α-naphthalene is also used. Mixtures of amines (PAN), phenyl-β-naphthylamine (PBN), preferably those based on phenylenediamine. Examples of phenylenediamines are N -isopropyl- N' -phenyl-p-phenylenediamine, N- 1,3-dimethylbutyl- N' -phenyl-p-phenylenediamine (6PPD), N -1,4-dimethylpentyl- N' -phenyl-p-phenylenediamine (7PPD), N,N' -bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD) .

Among other antioxidants are 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). Phosphites are generally used in combination with phenolic antioxidants. TMQ, MBI, and MMBI are primarily used for NBR types that are cured by peroxidation.

The ability to withstand ozone can be improved by the use of antioxidants known to those skilled in the art, such as N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N- 1,4-Dimethylpentyl-N'-phenyl-p-phenylenediamine (7PPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), Enol ether or cyclic acetal.

The processing aid is intended to act between the rubber particles and is intended to counteract the friction during the mixing, plasticizing and molding processes. The processing aids which may be present in the rubber mixture according to the invention are any lubricants conventionally used for plastic processing, such as hydrocarbons, such as oils, paraffins and PE waxes, fatty alcohols having 6 to 20 carbon atoms. Ketones, carboxylic acids, such as fatty acids and octadecanoic acid, oxidized PE waxes, metal salts of carboxylic acids, carboxamide, and carboxylic acids with, for example, the following alcohols and long-chain carboxylic acids as acidic components Acid esters: ethanol, fatty alcohol, glycerin, ethylene glycol, neopentyl alcohol.

The rubber mixture can be crosslinked not only by the sulfur promoter system but also by peroxide.

Examples of crosslinking agents which can be used are peroxygenated crosslinking agents such as bis(2,4-dichlorobenzyl) peroxide, dibenzoyl peroxide, bis(4-chlorobenzhydryl). Peroxide, 1,1-bis(tertiary butylperoxy)-3,3,5-trimethylcyclohexane, butyl perbenzoate, 2,2-bis (tertiary butyl) Peroxy)butene, 4,4-di-tertiary butylperoxypivalate, dicumyl peroxide, 2,5-dimethyl-2,5-di (third Butylperoxy)hexane, tertiary butyl cumyl peroxide, 1,3-bis(tri-butylperoxyisopropyl)benzene, di-tertiary butyl peroxide, and 2, 5-Dimethyl-2,5-di(tri-butylperoxy)hex-3-yne.

It may also be advantageous (along with the peroxidic crosslinking reagent) to use additional additives which may be used to increase the crosslinking yield: a suitable example here is triallyl isocyanurate, trimerization Triallyl cyanate, trimethylolpropane tri(meth)acrylate, triallyl 1,2,4-benzenetricarboxylate, ethylene dimethacrylate, butylene dimethacrylate, Trimethylolpropane trimethacrylate, zinc diacrylate, zinc dimethacrylate, 1,2-polybutadiene or N,N-meta-phenyl-maleimide.

Another crosslinker that can be used is a sulfur or sulfur donor in an elemental soluble or insoluble form.

Examples of sulfur donors that can be used are dimorphine disulfide (DTDM), 2-fosfolino-dithiobenzothiazole (MBSS), two Thiocaprolactam, bis(pentathiomethylammonium thiol) (DPTT), and tetramethylammonium thiocarbazide (TMTD).

For the sulfur-vulcanization of the rubber mixture according to the invention, it is also possible to use additional additives which can be used to increase the crosslinking yield. However, in principle, it is also possible to use sulfur or a sulfur donor for crosslinking separately.

Examples of suitable additives that can be used to increase the crosslinking yield include: dithiocarbamate, amine thiomethionine, thiazole, sulfoximine, xanthate, di- or polycyclic amine, Anthracene derivatives, dithiophosphates, caprolactam, and thiourea derivatives.

Examples of likewise suitable additives are: zinc diammonium diisocyanate, hexamethylenetetramine, 1,3-bis(nitricidinium methyl)benzene and cyclodisulfane.

Preferred is the sulfur promoter system in the rubber mixture according to the invention.

In order to reduce flammability and to reduce the generation of smoke during combustion, the rubber mixture composition according to the present invention may further comprise a flame retardant. Examples of flame retardants used are: antimony trioxide, phosphate, chloroparaffin, aluminum hydroxide, boron compounds, zinc compounds, molybdenum trioxide, ferrocene, calcium carbonate or magnesium carbonate.

The vulcanizate may also include additional synthetic polymers, for example as a polymeric processing aid or impact modifier. The synthetic polymer is selected from the group consisting of ethylene, propylene, butadiene, styrene, vinyl acetate, vinyl chloride, glycidyl acrylate, glycidyl methacrylate, and The alcohol component is branched or unbranched A homopolymer or copolymer of an acrylate of a C1-C10-alcohol and a methacrylate. Mention may in particular be made of polyacrylates having the same or different alcohol moieties from the group of C4-C8-alcohols, in particular butanol, hexanol, octanol, and 2-ethylhexanol, polymethyl Methyl methacrylate, methyl methacrylate-butyl acrylate copolymer, methyl methacrylate-butyl methacrylate copolymer, ethylene-vinyl acetate copolymer, chlorinated polyethylene, ethylene propylene copolymer, ethylene Propylene diene copolymer.

The vulcanized rubber according to the present invention can be used to produce a foam. For this purpose, a chemical or physical blowing agent is added. Chemical blowing agents which can be used are any of the substances used for this purpose, for example, azomethicin, p-toluenesulfonyl hydrazine, 4,4'-oxybis(phenylsulfonylhydrazine) , p-toluenesulfonylamine urea, 5-phenyltetrazole, N,N'-dinitropentamethylenetetramine, zinc carbonate, sodium hydrogencarbonate, and mixtures comprising the same. Examples of suitable physical blowing agents are carbon dioxide or halogenated hydrocarbons.

The vulcanization process can take place at a temperature of from 100 ° C to 200 ° C, preferably from 130 ° C to 180 ° C, optionally from 10 to 200 bar.

The rubber and filler and blending with the sulfur-containing additive of formula (I) can be carried out in/on a conventional mixing assembly, such as a roll, a closed mixer, and a mixing extruder.

The vulcanized rubber according to the invention is also suitable for the production of mouldings having improved properties, for example for the production of cable jackets, hoses, drive belts, conveyor belts, press rolls, tyres, soles, sealing rings and damping elements.

An important factor in rubber processing is that the rubber mixture originally prepared with the additive has a low flow viscosity (Muni viscosity, ML1 + 4/100 ° C), which makes it easy to process. In many applications, it is intended that the subsequent vulcanization process for the rubber mixture (e.g., at 170 ° C, t95) is carried out as quickly as possible by exposure to heat in order to limit the cost of time and energy.

The coking time (e.g., t5) is intended to be relatively long, depending on its molding process.

The loss factor tan Δ of the vulcanized rubber produced by heating the stone-containing rubber mixture according to the present invention at 170 ° C / t 95 is preferably < 0.2 at 60 ° C, and its Shore A hardness is simultaneously at 23 ° C. >67, and particularly preferably, the loss factor tan Δ is <0.17 at 60 ° C, and the Shore A hardness is >70 at 23 ° C at the same time. The vulcanized rubber has a 300 modulus of >12 MPa, preferably >15 MPa.

Preferably, the loss factor tan Δ of the vulcanized rubber produced from the vermiculite-containing rubber mixture by heating at 170 ° C / t 95 is < 0.17 at 60 ° C, and preferably its coking time is more than 1000 seconds at the same time.

Preferably, the loss factor tan Δ of the vulcanized rubber produced from the vermiculite-containing rubber mixture by heating at 170 ° C / t 95 is less than 0.17 at 60 ° C, and preferably the total vulcanization time is less than 2000 seconds at the same time. .

It is preferred that the vulcanized rubber produced from the vermiculite-containing rubber mixture by heating at 170 ° C / t95 has a coking time of more than 1000 seconds, and preferably has a total vulcanization time of less than 2000 seconds.

The Mn 1+4 viscosity of the vermiculite-containing rubber mixture at 100 ° C is preferably less than 150, preferably less than 100, particularly preferably less than 95.

Another invention is a vermiculite-containing rubber mixture according to the invention for the production of vulcanized rubber and rubber moldings of any type, in particular for the production of tires and tire components.

The automotive industry has sought a cost-effective way to achieve CO ₂ emissions targets of no more than 130 g/km, at least from the EU has been concerned about the limits of carbon dioxide emissions from automobiles. Tires with low rolling resistance are of substantial importance here. They reduce fuel consumption by requiring lower energy for deformation during free spin.

In order to achieve a reduction in rolling resistance at the expense of other important features, the requirements associated with wet grip and rolling noise have also been refined. The first sign of wet skid performance and rolling resistance is given by the loss factor tan Δ. It should be as high as possible (good wet skid resistance) at 0 ° C and as low as possible (low rolling resistance) from 60 ° C to 70 ° C. The hardness of the vulcanized rubber gives the first sign of its stiffness.

Example Example 1

Apparatus: 2000 ml four-necked flask with thermometer, pressure-balanced dropping funnel, reflux condenser with gas discharge attachment (bubble counter), and tubing, agitator

Initial 79.3 g = 0.2 mol Duralink HTS from Flexsys (98.48%)

Addition: 480 ml of demineralized water

33.6 g = 0.4 mol of sodium bicarbonate

32.5 g = 0.4 mol of about 37% formaldehyde solution

960 ml of toluene

Feed: 31.6 g = 0.4 mol of 2-mercaptoethanol (Aldrich, 99%)

Duralink HTS and water were used as the initial charge in the nitrogen flushing unit. The stirrer was opened and then sodium bicarbonate was added first followed by formaldehyde and toluene.

At a reaction temperature of from 20 ° C to 25 ° C, 2-mercaptoethanol was then added dropwise over about 30 minutes, which was filled with nitrogen.

Once the addition has ended, stirring is continued at 20 ° C to 25 ° C overnight. The mixture was transferred to a 2 l separatory funnel. The phases can be separated after the addition of 8.8 g of sodium chloride. The aqueous phase was then extracted twice with 300 ml of toluene. The combined organic phases were each extracted three times with 300 ml of demineralized water, dried over sodium sulfate and separated by filtration.

The product was extracted by freezing at -6 ° C, and separated by D4 frit, and dried at 25 ° C in a vacuum oven.

Yield: 30.2 g (50%) of the ideal chemical formula

Example 2

Batch: 0.25 mol

Apparatus: 2000 ml four-necked flask with thermometer, pressure-balanced dropping funnel, reflux condenser with gas discharge attachment (bubble counter), and tubing, 250 rpm agitator, pH meter

Initial charge: 99.1 g = 0.25 mol Duralink HTS from Flexsys (98.48%)

600 ml of demineralized water

42 g = 0.5 mol of about 37% formaldehyde solution

42 g = 0.5 mol of sodium bicarbonate

50 ml of toluene

Feed: 54.4 g = 0.5 mol thioglycerol (99.4%, Bruno Bock)

Duralink HTS and water were used as the initial charge in the nitrogen flushing unit. The stirrer was turned on and then sodium bicarbonate was added first, followed by formaldehyde and then toluene.

At a reaction temperature of from 20 ° C to 25 ° C, thioglycerol was then added dropwise over about 30 minutes, which was filled with nitrogen. Once the addition has ended, an additional 200 ml of demineralized water is added to make the mixture easier to stir. Stirring was then continued at 20 ° C to 25 ° C for 22 h and the solids were separated by suction filtration through a D4 frit. The product was washed six times with 500 ml of demineralized water (conductivity <0.3 millisiemens). The product was then dried in a vacuum drying oven at 25 ° C to a constant weight.

Yield: 80.4 g (90.6%) of the ideal chemical formula

Example 3

Apparatus: 2000 ml four-necked flask with thermometer, pressure-balanced dropping funnel, reflux condenser with gas discharge attachment (bubble counter), and tubing, 250 rpm agitator, Dulcometer

Initial charge: 88.6 g=0.22 mol Duralink HTS from Flexsys

600 ml of demineralized water

42 g = 0.5 mol of about 37% formaldehyde solution

42 g = 0.5 mol of sodium bicarbonate

Feed: 53.61 g = 0.5 mol of 3-mercaptopropionic acid (Aldrich, 99%)

Additive: 15% NaOH

37% HCl

Duralink HTS and water were used as the initial charge in the nitrogen flushing unit. The stirrer was opened and sodium bicarbonate was added first followed by formaldehyde.

At a reaction temperature of from 20 ° C to 25 ° C, 3-mercaptopropionic acid was then added dropwise over about 1 hour, which was filled with nitrogen. During the course of the reaction, the pH was maintained at pH 8 (± 0.2) with a 15% NaOH using a Dulcometer.

Once the addition had ended, the pH was adjusted to pH 2 with 37% hydrochloric acid at 22 (±1) °C with cooling under nitrogen.

The reaction suspension was then subjected to suction filtration by means of a D4 frit. The product was washed six times with 300 ml of demineralized water (conductivity <0.3 millisiemens). The product was dried to a constant weight at 25 ° C in a vacuum drying oven.

Yield: 50.8 g (64.4%) of the ideal chemical formula

Example 4

Device: 2000 ml four-necked flask with thermometer, pressure-balanced dropping funnel, reflux condenser with gas discharge accessory (bubble counter), and tubing, agitator, inlet manifold

Initial charge: 99.1 g = 0.25 mol Duralink HTS from Flexsys (98.48%)

600 ml of demineralized water

41.1 g=0.5 mol of about 36.5% formaldehyde solution

42 g = 0.5 mol of sodium bicarbonate

Feed: 78.7 g = 0.5 mol of 2-mercaptobenzoic acid (98%), dissolved in 500 ml of water at pH 8 by adding NaOH under nitrogen

Additive: 37% HCl

Duralink HTS and water were used as the initial charge in the nitrogen flushing unit. The stirrer was opened and sodium bicarbonate was added first followed by formaldehyde.

A solution of sodium 2-mercaptobenzoate was added dropwise at a reaction temperature of from 20 ° C to 25 ° C over about 1 hour, which was filled with nitrogen. Once the addition had ended, stirring was continued for 22 h and its pH was adjusted to pH 2 by hydrolysis with 37% hydrochloric acid from 20 ° C to 25 ° C under nitrogen.

Stirring was continued for another hour and the solid was separated by suction filtration through a D4 frit. The product was each washed with 300 ml of demineralized water (conductivity <0.3 millisiemens). The product was then dried in a vacuum drying oven at 25 ° C to a constant weight.

Yield: 113.3 g (99.7%) of the ideal chemical polysulfide mixture

Example 5:

Apparatus: 2000 ml four-necked flask with thermometer, pressure-balanced dropping funnel, reflux condenser with gas discharge attachment (bubble counter), and tubing, agitator, pH meter

Initial charge: 79.6 g = 0.2 mol Duralink HTS from Flexsys (98.14%)

272 ml of demineralized water

32.9 g = 0.4 mol of about 36.5% formaldehyde solution

33.6 g = 0.4 mol of sodium bicarbonate

40 ml of toluene

Feed: 791.7 g = 0.4 mol Na salt of morpholine dithiocarboxylic acid ( 11.7% )

Duralink HTS and water were used as the initial charge in the nitrogen flushing unit. The stirrer was opened and sodium bicarbonate was added first, followed by formaldehyde and then toluene.

The Na salt (aqueous solution) of morpholine dithiocarboxylic acid was added dropwise at a reaction temperature of from 20 ° C to 25 ° C in about 30 minutes, which was filled with nitrogen. Once the addition had ended, stirring was continued for 22 h at 20 ° C to 25 ° C and the solids were separated by suction filtration with D4 frit. The product was then washed four times with 300 ml of demineralized water (conductivity <0.3 millisiemens). The product was then dried in a vacuum drying oven at 35 ° C to a constant weight.

Yield: 35.9 g (38%) of the ideal chemical formula

result:

The following examples are provided to further illustrate the invention and are not intended to limit the invention.

The rubber formulations listed below in Table 1 were selected for these tests. All numerical data are based on "parts per hundred rubber" (phr) unless otherwise stated.

The following rubber mixture was produced in a 1.5 L closed mixer (70 rpm) at an initial temperature of 80 ° C for a mixing time of 5 minutes. Finally, sulfur and a promoter were mixed onto a roll (temperature: 50 ° C).

Surprisingly, as shown by the results in Table 2, the hardness (Shore A) measured in all of these examples was higher compared to the reference. Mechanical properties, such as tensile strength, elongation at break, and 300 modulus, remain almost unchanged here. All of the tested vulcanized rubbers exhibited good wet grip and comparable good rolling when compared to the reference (tan Δ > 0.35 at 0 ° C and tan △ < 0.2 at 60 ° C) Resistance, as well as the same very favorable wear value (<100 mm ³ ).

Testing of rubber mixtures and vulcanized rubber: Mui viscosity measurement:

The viscosity can be directly determined by the resistance exerted by the rubber (and rubber mixture) when processing them. In a Munni shear disc viscometer, the sample material is surrounded by a grooved disk up and down, and the disk is about The rate of 2 revolutions per minute is rotated in a heatable chamber. The force required for this purpose is measured in the form of torque and corresponds to the corresponding viscosity. The test piece was generally preheated to 100 ° C in one minute; the measurement took another 4 minutes while keeping the temperature constant.

The viscosity is given together with the corresponding test conditions, examples being ML (1+4) 100 ° C (Muni viscosity, large rotor, preheating time in minutes and test time, test temperature).

The viscosity of the rubber mixture indicated in Table 1 was measured by a Munney shear disc viscometer.

Coking performance (t5 coking time)

The same test as described above can also be used to measure the "coking" performance of the mixture. The temperature selected in this patent is 130 °C. After the rotor has been operated until the torque value has passed a minimum value, it rises to 5 Munier units (t5) relative to the minimum value. The larger the value (the unit here is seconds), the slower the coking (here the high coking value).

Rheometer (Vulcameter) full cure time of 170 ° C / t95:

The progress of vulcanization in MDR (moving die rheometer) and its analytical data were measured on an MDR 2000 Monsanto rheometer according to ASTM D5289-95. Table 2 summarizes the results of this experiment.

The time at which 95% of the rubber has been crosslinked is measured as the total cure time. The temperature chosen was 170 °C.

Hardness measurement:

In order to determine the hardness of the rubber mixture according to the present invention, a ground sheet made of a rubber composition having a thickness of 6 mm was produced according to the formulation of Table 1. A plurality of test specimens having a diameter of 35 mm were cut from the ground sheets, and the Shore A hardness was measured for these by a digital hardness tester (Zwick GmbH & Co. KG, Ulm).

Stretching test:

This tensile test is used to directly determine the load limit of the elastomer. The longitudinal elongation at break is divided by the initial length to give the elongation at break. Also measured to achieve a certain degree of elongation, mainly 50%, 100%, 200% and 300%, the required force, and expressed as modulus (given tensile strength of 300% elongation, or 300 modulus ).

Table 2 lists the results of this test.

Dynamic damping:

Dynamic testing methods are used to characterize the deformation properties of elastomers under cyclically varying loads. External stress changes the configuration of the polymer chain.

This measurement indirectly determines the loss factor tan Δ by the ratio between the loss modulus G" and the storage modulus G'.

Claims (31)

A vermiculite-containing rubber mixture produced from at least one rubber, from a sulfur-containing alkoxysilane, from a crosslinking agent, from a filler, and optionally from another rubber adjuvant, characterized in that The mixture comprises from 0.1 to 15 parts by weight of the non-sulfur polysulfide additive of formula (I) AS-(S) _x -SYS-(S) _x -SA (I) based on 100 parts by weight of the rubber used. X is 0, 1, or 2, Y is an optionally substituted or heteroatom-containing aliphatic, cycloaliphatic, or aromatic group, and the A moiety Wherein R ¹ to R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, or A moiety Wherein R ¹ and R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, or A moiety Wherein R ¹ and R ² are the same or different and are hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or the group -CH ₂ - OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, and R ⁶ is hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C _6- C ₁₀ -aryl or group -CH ₂ -OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -NHR ⁵ , -COR ⁵ , -COOR ⁵ , -CH ₂ COOR ⁵ , wherein R ⁵ = hydrogen , C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or C ₁ -C ₆ -fluorenyl, and y is 0, 1, or 2. A rubber mixture containing vermiculite according to item 1 of the patent application, which is characterized by one of the following groups of Y: Where a = from 2 to 12, Where a = from 2 to 12, Where b = from 1 to 4, Wherein b = from 1 to 4, and preferably Y-system-(CH ₂ ) ₆ -. A vermiculite-containing rubber mixture according to claims 1 and 2, characterized in that at least one compound of the formula (II) is used as the polysulfide additive A vermiculite-containing rubber mixture according to claims 1 and 2, characterized in that at least one compound of the formula (III) is used as the polysulfide additive A vermiculite-containing rubber mixture according to claims 1 and 2, characterized in that at least one compound having the formula (IV), (IVa), (V), (Va), (VI), or (VIa) Used as the polysulfide component A vermiculite-containing rubber mixture according to claims 1 and 2, characterized in that at least one compound of the formula (VII) is used as the polysulfide additive A rubber mixture containing vermiculite according to claims 1 and 2, characterized in that at least one compound of the formula (VIII) is used as the polysulfide additive, Wherein R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are, independently of each other, hydrogen, C ₁ -C ₆ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl or a group - CH ₂ -OR ⁵ , -CH ₂ -CH ₂ -OR ⁵ , -CH ₂ -COOR ⁵ , -CH ₂ -CH ₂ -COOR ⁵ , and R ⁸ and R ⁹ , and R ¹⁰ and R ¹¹ respectively Optionally, a ring is formed together with the respective nitrogen atoms, and R ⁵ is as defined above, and at least one of the portions R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ includes one or more oxygen atoms. A vermiculite-containing rubber mixture according to claim 7, characterized in that at least one compound of the formula (IX) is used as the polysulfide additive A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that at least one compound of the formula (X) is used as the polysulfide additive A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that at least one compound of the formula (XI) is used as a polysulfide additive A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the sulfur-containing alkoxydecane is present in an amount greater than or equal to the amount of the antimony-free polysulfide additive. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that it comprises at least one SBR rubber and at least one BR rubber. A vermiculite-containing rubber mixture according to claim 12, characterized in that it comprises at least one SBR rubber and at least one BR rubber having a SBR:BR weight ratio of from 60:40 to 90:10. A vermiculite-containing rubber mixture according to claim 13 which is characterized in that it further comprises at least one NR rubber. A vermiculite-containing rubber mixture according to claim 14 which is characterized in that it comprises at least one SBR rubber and at least one BR rubber and at least one NR rubber in a ratio of at least 60 and up to 85 percent by weight based on the rubber SBR, and BR based on rubber at least 10 and up to 35 percent by weight, and at least 5 and up to 20 percent NR by weight of rubber. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that it comprises from 1 to 15 parts by weight of one or more sulfur-containing alkoxydecanes based on 100 parts by weight of the rubber used. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that it comprises from 0.3 to 7 parts by weight, based on 100 parts by weight of the rubber used, of one or more of the antimony-free polysulfide additives. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the sulfur-containing alkoxydecane is used in a weight ratio of from 1.5:1 to 20 relative to the antimony-free polysulfide additive. : 1, preferably from 5:1 to 15:1. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the mixture comprises from 0.5 to 5 parts by weight of a non-twisted polysulfide additive based on 100 parts by weight of the rubber used. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that it comprises one or more inorganic and/or organic fillers, wherein the filler is used in an amount based on 100 parts by weight of the rubber system used. From 50 to 200 parts by weight, preferably from 60 to 120 parts by weight. A vermiculite-containing rubber mixture according to claim 20, characterized in that the filler is selected from the group consisting of oxidic and silicatic fillers, and carbon black or a mixture thereof. group. The vermiculite-containing rubber mixture of claim 21, wherein the at least one filler is selected from the group consisting of precipitated vermiculite and/or citrate, and the vermiculite and/or citrate has The specific surface area is from 20 to 400 m ² /g, and preferably has a specific surface area of from 100 to 200 m ² /g. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the loss factor tan Δ of the vulcanized rubber produced by heating at 170 ° C / t 95 is < 0.2 at 60 ° C, and The A hardness is simultaneously >67 at 23 ° C and its 300 modulus value is >12 MPa, preferably >15 MPa. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the loss factor tan Δ of the vulcanized rubber produced by heating at 170 ° C / t 95 is < 0.17 at 60 ° C, and A hardness is >70 at 23 °C. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the loss factor tan Δ of the vulcanized rubber produced by heating at 170 ° C / t 95 is less than 0.17 at 60 ° C, and its coking The time is more than 1000 seconds at the same time. The vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the loss factor tan Δ of the vulcanized rubber produced by heating at 170 ° C / t 95 is less than 0.17 at 60 ° C, and Its full cure time is less than 2000 seconds at the same time. A vermiculite-containing rubber mixture according to any one of the preceding claims, characterized in that the vulcanization rubber produced therefrom by heating at 170 ° C / t 95 has a coking time of more than 1000 seconds, and the total vulcanization time is simultaneously less than 2000 seconds. A vermiculite-containing rubber mixture according to claims 1 to 10, characterized in that the ML 1+4 viscosity of the mixture at 100 ° C is less than 150, preferably less than 100, particularly preferably less than 95. Use of a vermiculite-containing rubber mixture according to any of the preceding claims, for the production of vulcanized rubber and rubber moldings of any type, in particular for the production of tires and tire components. A vulcanized rubber and rubber molding, in particular a tire and a tire component, of any type, which is based on a vermiculite-containing rubber mixture according to any one of the preceding claims. a polysulfide additive having the following chemical formula,