DE19643827A1 - Rubber mixtures for e.g. tyres - Google Patents

Abstract

Rubber mixtures (M) containing a rubber, at least one filler, optional rubber processing aids and a crosslinking agent also contain at least one phosphorous ester prepared by reacting a haloalkyl silane of formula R<1>R<2>R<3>Si-X<1>-Hal (I), halogen phosphate of formula Y = P(O-X<2>-Hal)3 (II) and optional polyhalogen compounds of formula X<3>-(Hal)n (III) with a polysulphide of formula Me2Sx (IV) in a molar ratio of 0.05-1:0.03-0.5:0-0.9:1; (where R<1>-R<3> = 1-18C alkyl or 1-18C alkoxy, optionally containing N, O or S atoms in the chain, or 6-12C aryl(oxy), 7-18C arylalkyl or 7-18C arylalkoxy; X<1> = optionally unsaturated 1-2C alkyl; X<2> = 1-36C (cyclo)alkyl (optionally unsaturated and/or substituted with 6-12C aryl, 1-18C alkoxy or OH and/or containing O, S, N atoms or 6-12C aryl groups in the chain); X<3> = 1-36C (cyclo)alkyl (optionally unsaturated and/or substituted with 6-12C aryl, 1-18C alkoxy or OH and/or containing O, S, N atoms or 6-12C aryl groups in the chain) or 6-12C (hetero)aryl; Y = O or S; Me = ammonium or metal; n = 1-4; and x = 1-8), with the provision that at least one of R<1>-R<3> is an alkoxy or (alkyl)aryloxy. (M) contains 0.-15 (0.5-10) pts.wt. phosphorous ester and 10-200 (20-100) pts.wt. filler per 100 pts.wt. rubber.

Description

The present invention relates to new phosphorus-containing rubber mixtures and the use of these rubber mixtures for the production of rubber vulcanizates. The rubber mixtures according to the invention are suitable for the production of moldings, in particular for the production of tires, which have low rolling resistance as well as increased dynamic and thermal Have resilience.

Vulcanizates with improved hysteresis behavior are known, they have however, some undesirable properties. So in EP-A 253 365 Hysteresis improvers based on certain nitroamines described. Because of the However, there is a risk of re-nitrosation for rubber auxiliaries which are free of nitro and nitroso groups. Similar concerns also exist with the nitrosoanilines of US Pat. No. 4,690,965. EP-A 366 952 also includes Rubber vulcanizates are known to have reduced hysteresis losses that certain Contain diphenyl sulfides. The disadvantage is that these additives in natural rubber are ineffective and also break it down (see also US Pat. No. 2,470,948). In DE-A 2 141 159, 2 141 160 and 2 255 577 are certain Organosilanes described, which also improve the rolling resistance of Automotive tires can be used. The aim of the present invention was however, in addition to the reduced rolling resistance, the thermal resilience in the manufacture and use of the tires as well as the dynamic fatigue resistance improvement. This is achieved with the phosphorus esters of the present invention reached.

EP-A 670 347 describes rubber mixtures which contain special oligomeric sweat fel / silicon-containing reinforcing additives. These connections under differ structurally from the compounds of the present invention because they do not contain any phosphorus ester groups and therefore require fewer Have dispersing effect for silica fillers, which z. B. in a higher Expresses hardness and lower tensile strength of the rubber vulcanizates.

It has now been found that using the phosphoric esters according to the invention containing rubber mixtures vulcanizates with improved abrasion behavior, low dynamic damping as well as improved thermal and dynamic  Resilience can be maintained, so that this gives the possibility Rubber articles in a shorter time at a higher temperature without loss of quality manufacture or rubber parts at higher temperatures for longer Time to use.

The present invention therefore relates to rubber mixtures tend a rubber, at least one filler, optionally further chew Chuk auxiliaries and crosslinkers, and at least one phosphorus ester is obtained from the reaction of a haloalkylsilane (I), a halogen phosphate (II) and optionally further polyhalogen compounds (III) with a Polysulfide (IV)

R ¹ R ² R ³ Si-X ¹ -Hal, (I)

Y = P (OX ² -Hal) ₃ , (II)

X ³ - (Hal) _n , (III)

Me ₂ S _x , (IV)

wherein R ¹ , R ² and R ^{3 are the} same or different and represent C ₁ -C ₁₈ alkyl or C ₁ -C ₁₈ alkoxy groups, which may optionally be interrupted by nitrogen, oxygen or sulfur atoms, or C ₆ - C ₁₂ aryl or aryloxy, C ₇ -C ₁₅ alkylaryl or alkylaryloxy groups, with the proviso that at least one of the radicals R ¹ to R ^{3 is} an alkoxy, aryloxy or alkylaryloxy group;
X ^{1 represents} a divalent linear, branched or cyclic, optionally unsaturated, C ₁ -C ₁₂ -alkyl radical,
X ^{2 represents} an optionally substituted with C ₆ -C ₁₂ aryl, C ₁ -C ₁₈ alkoxy or hydroxyl groups, linear, branched or cyclic, optionally unsaturated, divalent C ₁ -C ₃₆ alkyl radical, which optionally can be interrupted by oxygen, sulfur or nitrogen atoms or aromatic C ₆ -C ₁₂ groups,
X ³ for a di-, tri- or tetravalent linear, branched or cyclic, optionally unsaturated and divalent C ₁ -C ₃₆ group optionally substituted with C ₆ -C ₁₂ aryl, C ₁ -C ₁₈ alkoxy or hydroxyl groups Alkyl radical, which can optionally be interrupted by oxygen, sulfur or nitrogen atoms or aromatic C ₆ -C ₁₂ groups, and represents C ₆ -C ₁₂ aryl groups or heteroaryl groups,
Y represents an oxygen or sulfur atom,
Me represents ammonium or a metal atom,
n stands for an integer from 1 to 4 and
x means an integer from 1 to 8,
wherein the molar ratio of the components (I): (II): (III): (IV) depends on the number of halogen atoms bonded and 0.05-1.0 mol (I): 0.03-0.5 mol (II): 0-0.9 mol (III): 1 mol (IV), preferably 0.3-1.0 mol (I): 0.1-0.35 mol (II): 0-0.7 mol (III); 1 mol (IV) is the phosphoric ester in amounts of 0.1-15, preferably 0.5-10 parts by weight and the fillers in amounts of 10-200, preferably 20-100 parts by weight, based in each case 100 parts by weight of rubber can be used.

Particularly preferred phosphorus esters that are used in the mixture according to the invention are, for. B. prepared from haloalkylsilanes of formula (I), wherein X ^{1 represents} divalent methylene, propylene, butylene, pentylene or hexylene radicals and R ¹ , R ² , R ³ methoxy, ethoxy, propoxy or butoxy radicals mean and Hal is chlorine, and from haloalkylphosphates of the formula (II) in which X ^{2 is} divalent methylene, ethylene, propylene, butylene, hexylene, cyclohexylene, octylene, decylene, dodecylene, 2.2'- Oxidiethylen-, methylene-bis- (2,2'-oxi ethylene) -, ethylene- (bis- (2,2'-oxyethylene)) radicals, Y represents oxygen and Hal represents chlorine, and from polyhalogen compounds of the formula (III), in which X ³ for methylene, ethylene, propylene, butylene, hexylene, cyclohexylene, octylene, decylene, dodecylene, 2,2'-oxidiethylene, methylene bis (2,2'-oxyethylene) -, ethylene - (bis- (2.2'-oxiethylene) -, - (CH ₂ CH ₂ -O-) _3-10 -CH ₂ CH ₂ -, 2.2'-thiodiethylene, N-methyl-N'.N '' - diethylene -, or alpha, alpha'-p-xylidene radicals or higher-valent radicals such as 1,2,3-propylidene radical t, Hal stands for chlorine and in which n means integers from 1-4.

The metal polysulfides used are preferably those of the formula Me ₂ S _x , in which Me represents lithium, sodium or potassium, and x is an integer from 2 to 6.

The phosphoric esters to be used are low-viscosity to high-viscosity oils and have molecular weights between 500 and 10,000.

The phosphoric esters according to the invention are produced by reaction of haloalkylsilyl ethers (I), haloalkyl phosphates (II) and optionally further polyhalogen compounds (III) with metal polysulfides in the presence of alcoholic solvents at temperatures from 0 ° C to 150 ° C, preferably 30 up to 120 ° C, optionally under pressure of 1 to 20 bar.

The following are preferably used as alcoholic solvents: methanol, ethanol, n-propanol, i-propanol, i-butanol, amyl alcohol, hexyl alcohol, n-octanol, i- Octanol, ethylene glycol, 1,2- and 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol and mixtures of these alcohols with aromatic, aliphatic and / or cycloaliphatic hydrocarbons, such as toluene, xylene, cyclohexane, hexane, Octane, or open-chain and / or cyclic ethers, such as diethyl ether, dibutyl ether, Tetrahydrofuran, 1,3-dioxolane.

Particularly preferred phosphorus esters are mixtures of linear or branched oligomers or polymers, produced by reacting a metal polysulfide with one or more haloalkylsilanes, haloalkylphosphates and optionally further polyhaloalkanes, the following products being preferred as haloalkylsilanes (III):
1-chloromethyltrimethoxysilane, 1-chloromethyltriethoxysilane, 1-chloromethyltributoxysilane, 1-chloromethyl-triethoxiethoxisilane, 1-chloromethyl-methyl-dimethoxisilane, 1-chloromethyl-diethoxisilane, 1-chloromethyl-methyl-dilutoxysilane, 1-chloromethyl-methyl-dibutoxane-1 dimethyl-ethoxisilane, 1-chloromethyl-dimethyl-butoxysilane, 3-chloropropyltrimethoxisilane, 3-chloropropyltriethoxisilane, 3-chloropropyltri propoxisilane, 3-chloropropyltributoxisilane, 3-chloropropylpentoxisilane, 3-chloropropyliloxyliloxane, 3-chloropropyliloxyliloxane - silane, 3-chloropropyl-triethoxyethoxi) -silane, 3-chloropropyl-triphenoxisilane, 3-chloropropyl-methyldimethoxysilane, 3-chloropropyl-methyl-diethoxisilane, 3-chloropropyl methyl-dibutoxisilane, 3-chloropropyl-dimethyl-3-methoxysilane Chlorpropyl-dime thyl-ethoxisilane and 3-chloropropyl-diethyl-phenoxisilane.

Preferred haloalkyl phosphates (II) are 2-chloroethyl diethyl phosphate, 2- Chloroethyl dioctyl phosphate, 2-chloroethyl diphenyl phosphate, bis (2-chloroethyl) ethyl phosphate, bis (2-chloropropyl) ethyl phosphate, bis (2-chloroethyl) octyl phosphate, Bis (2-chloroethyl) phenyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloro propyl) phosphate, tris (3-chloropropyl) phosphate and the corresponding thio phosphates.

Preferred polyhalogen compounds (in) are alkyl monohalides, such as methyl chloride, ethyl chloride, propyl chloride, butyl chloride, hexyl chloride, octyl chloride, dodecyl chloride, octadecyl chloride, benzyl chloride, chloroethanol, chloropropanol, and alkylene dihalides, in which X ^{3 is} methylene, ethylene, propylene, 2- Hydroxypropylene, butylene, hexylene, cyclohexylene, octylene, decylene, dodecylene, 2,2'-oxidiethylene, methylene bis (2,2'-oxiethylene) -, - (CH ₂ CH ₂ -O ) _1-10 - CH ₂ CH ₂ -, 2,2'-thiodiethylene, N-methyl-N ', N''- diethylene or α, α-p-xylidene radicals. Higher-value polyhalogen compounds such as 1,2.3-trichloropropane and 1.3.5-trichlorotriazine, the amount of which should, however, be kept so small that the end products are not insoluble in organic solvents by crosslinking, can be used. The polyhalogen compounds (III) can be used individually or in a mixture.

Particularly preferred phosphorus esters are e.g. B .:

The addition of the phosphoric esters and the addition of the fillers to the Rubbers are preferably made at melt temperatures of 100-200 ° C, they can but also later at lower temperatures (40-100 ° C) z. B. together with other additional rubber auxiliaries.

The phosphoric esters to be used can be used both in pure form and pulled the mixing process on an inert organic or inorganic carrier be added. Preferred carrier materials are silicas, natural ones or synthetic silicates, aluminum oxide or carbon black. Applying on solid Carrier materials can be mixed by simple mixing, if necessary in the Heat to react the silyl groups with the filler surface with elimination of alcohols, as well as by application from an aqueous dispersion or Solution in organic solvent.  

Suitable fillers for the rubber vulcanizates according to the invention are:

• - carbon black; the carbon blacks to be used here are produced by the soot, furnace or gas black process and have BET surface areas of 20-200 m ² / g, such as. B. SAF, ISAF, IISAF, HAF, FEF or GPF carbon blacks.
• - highly disperse silicas, manufactured e.g. B. by precipitation of solutions of silicates or flame hydrolysis of silicon halides with speci fischen surfaces of 5-1000, preferably 20-400 m ² / g (BET surface) and with primary particle sizes of 10-400 nm. The silicas can optionally also as Mixed oxides with other metal oxides, such as Al, Mg, Ca, Ba, Zn, Zr, Ti oxides are present.
• - Synthetic silicates, such as aluminum silicate, alkaline earth silicates, such as magnesium silicate or calcium silicate, with BET surfaces of 20-400 m ² / g and primary particle diameters of 10-400 nm.
• - Natural silicates, such as kaolin and other naturally occurring pebbles acids.
• - Glass fibers and glass fiber products (mats, strands) or micro glass balls.

Carbon blacks with BET surface areas of 20-400 m ² / g and highly disperse silicas are preferred, produced by precipitation of solutions of silicates with BET surface areas of 20-400 m ² / g, in amounts of 5-150 parts by weight, based on 100 parts by weight of rubber, used together with the phosphorus esters.

The fillers mentioned can be used alone or in a mixture. In In a particularly preferred embodiment of the method, 10 to 150 parts by weight Parts of light fillers, optionally together with 0-100 parts by weight of carbon black, and 0.3 to 10 parts by weight of phosphoric ester, each based on 100 parts by weight Rubber, as well as other rubber auxiliaries in the usual quantities for the manufacture used the vulcanizates.

In addition to natural rubber, synthetic rubbers can also be used as rubbers will. Preferred synthetic rubbers are for example from I. Franta,  Elastomers and Rubber Compounding Materials, Elsevier, New York 1989, or also in Ullmann's Encyclopedia of Industrial, Vol. A 23, VCH Publishing company, Weinheim 1993. They include a.

BR - polybutadiene
ABR - butadiene / acrylic acid C _1-4 alkyl ester copolymers
IR - polyisoprene
SBR - styrene / butadiene copolymers with styrene contents of 1 to 60, preferably 2 to 50% by weight
XSBR - styrene / butadiene copolymers and graft polymers with other unsaturated polar monomers, such as. B. acrylic acid, methacrylic acid, acrylonitrile, hydroxyethyl acrylate, hydroxyethyl methacrylate, with styrene contents of 2-50 wt .-% and levels of copolymerized polar monomers of 1-30 wt .-%
IIR - isobutylene / isoprene copolymers
NBR - butadiene / acrylonitrile copolymers with acrylonitrile contents of 5 to 60, preferably 10 to 50% by weight
HNBR - partially hydrogenated NBR rubbers in which up to 98.5% of the double bonds are hydrogenated
EPDM - ethylene / propylene / diene copolymers

as well as mixtures of these rubbers.

For the manufacture of motor vehicle tires, natural rubber, emulsion SBR and solution SBR rubber with a glass transition temperature above - 50 ° C, optionally with silyl ethers or other functional groups can be modified, such as. B. described in EP-A 447 066, polybutadiene rubber with high cis-1.4 content, which with catalysts based on Ni, Co, Ti or Nd is produced, as well as polybutadiene rubber with a vinyl content of 0-75% and their mixtures of interest.

The rubber vulcanizates according to the invention can further rubber auxiliary pro Products contain, such as reaction accelerators, anti-aging agents, heat stabilizers sensors, light stabilizers, antiozonants, processing aids, soft makers, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retarders, metal oxides and activators such as triethanolamine, Polyethylene glycol, hexanetriol, which are known to the rubber industry.  

The rubber auxiliaries are in usual amounts, which can be found in, among others judge the intended use. Usual amounts are e.g. B. Quantities from 0.1-50 parts by weight based on 100 parts by weight of rubber.

The phosphoric esters can serve alone as crosslinkers. As another known ver sulfur or peroxides can be used. The invention Rubber compounds can also contain vulcanization accelerators Examples of suitable vulcanization accelerators are mercaptobenzthia zoles, -sulfenamides, guanidines, thiurams, dithiocarbamates, thioureas and Thiocarbonates. The crosslinking accelerators and sulfur or peroxides will be in amounts of 0.1-10% by weight, preferably 0.1 to 5% by weight, based on the Total amount of rubber used.

The vulcanization can take place at temperatures of 100-200 ° C, preferably 130 to 180 ° C, optionally under pressure of 10-200 bar.

The rubber can be mixed with the filler and the phosphorus esters in conventional mixing units, such as rollers, internal mixers and mixing extruders, be performed.

The rubber vulcanizates according to the invention are suitable for the production of Shaped bodies, e.g. B. for the production of cable jackets, hoses, blowing belts, conveyor belts, roller coverings, tires, shoe soles, sealing rings and Damping elements, especially tires.  

Examples example 1

70.2 g (0.9 mol) of anhydrous N-S was mixed with 86.4 g (2.7 mol) of sulfur Solvent mixture of 315 ml ethanol, 315 ml xylene and 11.3 g dipropy Lenglycol heated to 70 ° C for 30 minutes. Then only 216.4 g (0.9 mol) of 3- Chlorpropyltriethoxisilan and then 98.3 g (0.3 mol) of tris- (2-chloriso propyl) phosphate (Levagard PP, Bayer AG). After stirring for 10 hours was filtered and the solution evaporated in vacuo. 380 g of one were obtained yellow oil with a viscosity of 600 mPas (25 ° C).

Example 2

70.2 g (0.9 mol) of anhydrous N-S was mixed with 86.4 g (2.7 mol) of sulfur Solvent mixture of 315 ml ethanol, 315 ml xylene and 11.3 g dipro pylene glycol heated to 70 ° C for 30 minutes. Then you only put 216.4 g (0.9 mol) 3-chloropropyltriethoxysilane and then 85.7 g (0.3 mol) of tris (2-chloroethyl) phosphate added. After stirring for 10 hours, the mixture was filtered and the solution in Evaporated vacuum. This gave 329 g of a yellow oil with a viscosity of 40 mPas (25 ° C).

Elemental analysis

Example 3

93.6 g (1.2 mol) of anhydrous Na ₂ S was mixed with 115.2 g (3.6 mol) of sulfur in a solvent mixture of 400 ml of ethanol, 400 ml of xylene and 12.1 g of dipropylene glycol at 70 ° C. for 30 minutes heated. Then only 144.5 g (0.6 mol) of 3-chloropropyltriethoxysilane were added, followed by 103.8 g (0.6 mol) of bis (2-chloroethyl) formal and finally 65.5 g (0.05 2 mol) of tris (2-chloroisopropyl) phosphate (Levagard PP, Bayer AG) was added. After stirring for 10 hours, the mixture was filtered and the solution was evaporated in vacuo. 387 g of a yellow oil with a viscosity of 1.0 Pas (25 ° C.) were obtained.

Elemental analysis

Example 4

130 g (1.666 mol) of anhydrous N-S was combined with 160 g (5 mol) of sulfur in one Solvent mixture of 400 ml ethanol, 400 ml xylene and 21 g dipropylene Glycol heated to 70 ° C for 30 minutes. Then only 240.4 g (1 mol) of 3- Chloropropyltriethoxysilane and then 115.3 g (0.666 mol) of bis (2-chloroethyl) formal and finally 95.1 g (0.333 mol) of tris (2-chloroethyl) phosphate. After stirring for 10 hours, the mixture was filtered and the solution in vacuo evaporated. 522 g of a yellow oil with a viscosity of 1.25 Pas (25 ° C).

Example 5 Production of rubber vulcanizates

The rubber mixtures were produced in a rubber kneader (type Werner & Pfleiderer GK 1.5) at 130 ° C within 5 minutes. accelerator and sulfur was finally mixed in on a roller at 50 ° C. The Finished rubber compounds were then vulcanized at 160 ° C. The Heating times are shown in the table.  

Claims (3)

1.Rubber mixtures containing a rubber, at least one filler, optionally further rubber auxiliaries and crosslinking agents, and at least one phosphorus ester which is obtained from the reaction of a haloalkylsilane (I), a halogenophosphate (II) and optionally further polyhalogen compounds (III) with a polysulfide ( IV) R ¹ R ² R ³ Si-X ¹ -Hal, (I) Y = P (OX ² -Hal) ₃ , (II) X ³ - (Hal) _n , (III) Me ₂ S _x , (IV )wherein
R ¹ , R ² and R ^{3 are the} same or different and represent C ₁ -C ₁₈ alkyl or C ₁ - C ₁₈ alkoxy groups, which may be interrupted by nitrogen, oxygen or sulfur atoms, or C ₆ - C ₁₂ aryl or aryloxy, C ₇ -C ₁₈ alkylaryl or alkylaryloxy groups, with the proviso that at least one of the radicals R ¹ to R ^{3 is} an alkoxy, aryloxy or alkylaryloxy group;
X ^{1 represents} a divalent linear, branched or cyclic, optionally unsaturated, C ₁ -C ₂ -alkyl radical,
X ^{2 represents} a linear, branched or cyclic, optionally unsaturated, divalent C ₁ -C ₃₆ alkyl radical which is optionally substituted by C ₆ -C ₁₂ aryl, C ₁ -C ₁₈ alkoxy or hydroxyl groups and which is optionally substituted by Oxygen, sulfur or nitrogen atoms or aromatic C ₆ -C ₁₂ groups can be interrupted,
X ³ for a di-, tri- or tetravalent linear, branched or cyclic, optionally unsaturated and divalent C ₁ -C ₃₆ - optionally substituted with C ₆ -C ₁₂ aryl, C ₁ -C ₁₈ alkoxy or hydroxyl groups alkyl radical, optionally interrupted by oxygen, sulfur or nitrogen atoms or aromatic C ₆ - C ₁₂ groups may be interrupted, as well as for C ₆ -C ₁₂ aryl groups or heteroaryl group,
Y represents an oxygen or sulfur atom,
Me represents ammonium or a metal atom,
n stands for an integer from 1 to 4 and
x means an integer from 1 to 8,
wherein the molar ratio of the components (I): (II): (III): (IV) depends on the number of halogen atoms bonded and 0.05-1.0 mol (I): 0.03-0.5 mol (II): 0-0.9 mol (III): 1.0 mol (IV), the phosphoric ester in amounts of 0.1-15, preferably 0.5-10 parts by weight, and the fillers in amounts from 10-200, preferably 20-100 parts by weight, based in each case on 100 parts by weight of rubber, are used. 2. Use of the rubber mixtures according to claim 1 for the production of rubber vulcanizates. 3. Use of the rubber mixtures according to claim 1 for the production of tires.