The present application claims priority under 35 U.S.C. § 119 to German application 10 2005 038 791.8, filed on Aug. 17, 2005, the contents of which is incorporated by reference in its entirety.
The present invention is directed to organosilicon compounds, their preparation and their use.
The synthesis of
U.S. Pat. No. 4,048,206 discloses the synthesis of a compound of the general formula X′-Z′-Si(OR′)3N, where X′may be R″C(O)M′, M′ may be S, R″ may be alkyl, Z′ may be a bivalent hydrocarbon and R′ may be —CH2—CH2— or —CH(CH3)—CH2—. These compounds can be used, inter alia, as an additive for synthetic polymers.
In addition, the synthesis of
Compounds of the formula R′—S—(CH2)n′Si(O—CH(CH3)CH2)3−-m′(O—CH2—CH2)m′N are known from J. Gen. Chem. USSR (EN), 49, 1979, 529-536.
The synthesis of compounds of the formulae
Furthermore, the synthesis of (R′O)2P(S)SCH2Si(OCH2CH2)3N and (R′O)2P(S)S(CH2)3Si(OCH2CH2)3N is known from Bull. Acad. Sci. USSR Div. Chem. Sci. (EN), 36, 8, 1987, 1745-1747 (Voronkov et al.).
One disadvantage of the known compounds concerns their processing behaviour in rubber mixtures, especially at high mixture viscosities.
It is an object of the invention to provide organosilicon compounds which cannot release volatile alcohols during the binding to the filler, at the same time have a high reactivity to filler and polymer and result in improved processability, for example a low viscosity of the mixture, good extrusion behaviour, good flowability, an appropriate Mooney scorch time or an improved incubation time, and/or improved dynamic properties in rubber mixtures. The invention relates to organosilicon compounds of the general formula (I),
Q—[S—G—Si(—O—CX1X2—CX1X3—)3N] (I)
in which Q is
R can preferably be methyl, ethyl, propyl, butyl or cyclohexyl, C7H15, C9H19, C11H23, C13H27, C15H31, phenyl, p-tolyl, o-tolyl or m-tolyl group. The substituted hydrocarbon groups R may be substituted by halogen, —COOR or HS—.
G can preferably be —CH2—, —CH2CH2—, —CH2CH2CH2—, —CH2CH2CH2CH2—, —CH(CH3)—, —CH2CH(CH3)—, —CH(CH3)CH2—, —C(CH3)2—, —CH(C2CH5)—, —CH2CH2CH(CH3)—, —CH(CH3)—CH2CH2—, —CH2CH(CH3)CH2—, —CH2—C6H4—CH2——CH2—C6H4—CH2—CH2— or —CH2—CH2-C6H4—CH2—CH2—.
Z can preferably be —CH2—, —CH2CH2—, —CH2CH2CH2—, —CH2CH2CHCH2—, —CH2CH2CH2CH2CH2—, —CH2CH2CH2CH2CH2CH2—, —CH(CH3)—, —CH2CH(CH3)—, —CH(CH3)CH2—, —C(CH3)2—, —CH(C2H5)—, —CH2CH2CH(CH3)—, —CH(CH3)—CH2CH2—, —CH2CH(CH3)CH2—, —C4H8—, —C6H12—, —C8H16—, —C10H20—, —C12H24—, —C6H4—, —CH2—C6H4—CH2—, —CH2—C6H4—CH2—CH2—, —CH2CH2—C6H4—CH2—CH2—, —NH—(CH2)2—NH—, —NH—(CH2)3—NH—, —NH—(CH2)4—NH—, —NH—(CH2)5—NH—, —NH—(CH2)6—NH—, —NH—(CH2)7—NH—, —NH—(CH2)8—NH—, —NH—(CH2)9—NH—, —NH—(CH2)10—NH—, —NH—(CH2)11—NH—, —NH—(CH2)12—NH—,
The following substituted aryl groups and aralkyl groups are particularly preferred for X8 and X9:
Organosilicon compounds of the general formula (I) may be mixtures of organosilicon compounds of the general formulae (I). Organosilicon compounds of the general formula (I) may be hydrolysis products of the organosilicon compounds of the general formula (I).
Organosilicon compounds of the general formula (I) where Q is X8—C(═O)— may be:
Organosilicon compounds of the general formula (I) may be:
Organosilicon compounds of the general formula (I) where Q is (X8)2N—C(═O)— and M′═S or O may be:
Organosilicon compounds of the general formula (I) where Q is Y—C(═M′)—Z—C(C═M′)— and M′═S or O may be:
Organosilicon compounds of the general formula (I) may furthermore be:
The invention furthermore relates to a process for the preparation of the organosilicon compounds according to the invention, which is characterized in that at least one organosilicon compound of the general formula (II)
X10[S—G—Si(—O—CX1X2—CX1X3—)3N] (II)
in which G, X1, X2 and X3 have the above mentioned meanings and X10 is H, alkali metal, for example Li, Na or K, alkaline earth metal or ammonium cation, for example alkylammonium cation, dialkylammonium cation, trialkylammonium cation or tetraalkylammonium cation, is reacted with at least one organic or inorganic acid anhydride, one organic or inorganic acid halide or organic or inorganic ester selected from the group consisting of
Carboxylic acid chlorides, dicarboxylic acid chlorides, dicarboxylic acid dichlorides, halogen-containing phosphorus compounds, particularly preferably P(═O)Cl3 or P(═S)Cl3, or halogen-containing organosilicon compounds of the form X4X5X4SiCl, X4X5X4SiBr, X4X5SiCl2, X4X5SiBr2, X4SiCl3 or XXSiBr3, particularly preferably Me3SiCl, C3H7—SiCl3, C4H9—SiCl3, C8H17—SiCl3 or C16H33—SiCl3, can preferably be used as organic or inorganic acid chlorides.
The reaction can be effected in the presence of an auxiliary base in a suitable solvent.
For example, amines, preferably dialkyl-substituted amines, particularly preferably trialkyl-substituted amines, can be used as an auxiliary base.
Solvents used may be aprotic solvents. Alkanes, preferably pentane, cyclohexane or heptane, aromatics or substituted aromatics, preferably benzene, toluene, xylene or mesitylene, can be used as aprotic solvents.
Examples of organosilicon compounds of the formula (II) may be:
The organosilicon compounds of the general formula (II) can be prepared by reacting compounds of the general formula (III),
N((CX1X3—CX1X3—O)3Si—G—Su—G—Si(O—CX1X2—CX1X3)3N (III)
in which u is ≦2, with alkali metals, alkaline earth metals or hydride compounds thereof, with the aim of forming compounds of the general formula alkali metal-S—G—Si(O—CX1X2—CX1X3)3N or N(CX1X3—CX1X3—O)3Si—G—S-alkaline earth metal-S—G—Si(O—CX1X2—CX1X3)3N.
The invention furthermore relates to a process for the preparation of the organosilicon compounds according to the invention, which is characterized in that a compound of the general formula (IV),
Q(—SH) (IV)
in which Q has the above mentioned meaning, is subjected to an addition reaction with an organosilicon compound containing at least one double bond (═) and of the general formula (V)
CX1X2═CX2—G1—Si(O—CX1X2X—CX1X3)3N (V)
in which X1, X2 and X3 have the abovementioned meanings and —CX1X2—CHX2—G1 or HCX1X2—CX2(−)—G1 is G.
The addition reaction can be initiated by free radicals or catalysed. The addition reaction can be accelerated and/or controlled by UV light.
Preferred compounds of the general formula (IV) Q(—SH) may be thiocarboxylic acids of the general formula X8—C(═O)—SH. Preferred thiocarboxylic acids may be compounds X8—C(═O)—SH where X8 is (C3-C24)-alkyl, particularly preferably (C7-C24)-alkyl, very particularly preferably (C11-C17)-alkyl, aralkyl, preferably tolyl or aryl, preferably phenyl.
Preferred organosilicon compounds of the general formula (V) may be CH2═CH—CH2—Si(O—CX1X2—CX1X3)3N, CH2═CH—CH2—CH2—Si(O—CX1X2—CX1X3)3N, CH(CH3)═CH—CH2—Si(O—CX1X2 —CX1X3 )3N or CH2═CH—Si(O—CX1X2—CX1X3)3N, very particularly preferably CH2═CH—CH2—Si(O—CH2—CH2)3N, CH2═CH—CH2—CH2—Si(O—CH2—CH2)3N, CH(CH3)═CH—CH2—Si(O—CH2—CH2)3N or CH2═CH—Si(O—CH2—CH2)3N.
The invention furthermore relates to a process for the preparation of the organosilicon compounds according to the invention, which is characterized in that a compound of the general formula (VI)
Q(—S—X10) (VI)
in which Q and X10 have the above mentioned meanings, is reacted with a compound of the general formula (VII),
halogen-G—Si(O—CX1X2—CX1X3)3N (VII)
in which G, X1, X2 and X3 have the above mentioned meanings.
Preferred halogen may be Cl, Br and I.
Preferably, compounds of the general formula (VI) may be Q—(S-alkali metal) and compounds of the general formula (VII) may be Cl—G—Si(O—CH2—CH2)3N. Very particularly preferably, compounds of the general formula (VI) X8—C(O)—S-alkali metal or R—C(S)—S-alkali metal can be reacted with compounds of the general formula (VII) Cl—CH2—Si(O—CH2—CH2)3N,
The invention furthermore relates to a process for the preparation of the organosilicon compounds according to the invention, which is characterized in that at least one silane of the general formulae VIII-XI,
Q—[S—G—Si(alkoxy)3] (VIII)
(alkoxy)3Si—G—S—C(═O)—Z—C(═O)—S—G—Si(alkoxy)3 (IX)
(alkoxy)3Si—G—S—C(═S)—Z—C(═S)—S—G—Si(alkoxy)3 (X)
(alkoxy)3Si—G—S—C(═NR)—Z—C(═NR)—S—G—Si(alkoxy)3 (XI)
in which G, Q, and z have the above mentioned meanings and alkoxy, independently of one another, are (C1-C24)-alkoxy, preferably methoxy, ethoxy or propoxy, is reacted with compounds of the general formula XII,
(HO—CX1X2—CX1X3—)3N (XII)
in which X1, X2, and X3 have the abovementioned meanings, with elimination of (alkoxy)-H, and (alkoxy)-H is separated from the reaction mixture. The reaction can be effected with or without catalysis. The (alkoxy)-H can be separated continuously or batchwise from the reaction mixture.
Examples of compounds of the general formula XII include: triethanolamine, triisopropanolamine and [HO—CH(phenyl)CH2]3N.
A low water content of the compounds of the formula XII which are used may have an advantageous effect on the composition and the product properties of the compounds according to the invention. Preferably, the compounds of the formula XII can have a water content of less than 1% by weight, particularly preferably of less than 0.5% by weight, very particularly preferably of less than 0.3% by weight, exceptionally preferably of less than 0.2% by weight.
The reaction can be carried out in typical organic solvents having a boiling point of less than 200° C., preferably less than 160° C, particularly preferably less than 130° C., very particularly preferably less than 100° C.
A reaction in the absence of organic solvents may be preferred.
One of the starting compounds may be present as a melt, suspension or solution.
One or more of the reaction products may be present as a melt, suspension or solution.
The reaction in the absence of organic solvents may be preferred owing to the higher yields achieved compared with the reactions in solvents.
The reaction in the absence of organic solvents may be preferred owing to the higher purity achieved for the products obtained compared with the reactions in solvents.
The reaction in the absence of organic solvents may be preferred owing to the absence of traces of solvent in the products obtained.
The reaction in the absence of organic solvents may be preferred owing to the minimization of volatile organic compounds (VOC) in the products obtained.
The reaction in the absence of organic solvents may be preferred owing to the omission of a drying step in the process, for removing traces of solvent, compared with the reaction in organic solvents.
In the process according to the invention, metal-free or metal-containing catalysts can be used as a catalyst. Metal compounds of the 3rd-7th group, of the 13th-14th group and/or of the lanthanide group may be used as metal-containing catalysts.
Transition metal compounds may be used as metal-containing catalysts.
The metal-containing catalysts may be metal compounds, such as, for example, metal chlorides, metal oxides, metal oxychlorides, metal sulphides, metal sulphochlorides, metal alcoholates, metal thiolates, metal oxyalcoholates, metal amides, metal imides or transition metal compounds having multiple bound ligands.
For example metal compounds used may be halides, amides or alcoholates of the 3rd main group (M3+=B,Al,Ga,In,Tl: M3+(OMe)3, M3+(OEt)3, M3+(OC3H7)3, M3+(OC4H9)3),
The metal and transition metal compounds may have a free coordination site on the metal.
Metal or transition metal compounds which are formed by addition of water to hydrolysable metal or transition metal compounds can also be used as catalysts.
For example, titanium alkoxides can be used as metal-containing catalysts.
In a particular embodiment titanates, such as, for example, tetra-n-butyl orthotitanate, tetraethyl orthotitanate, tetra-n-propyl orthotitanate or tetraisopropyl orthotitanate, can be used as catalysts.
Organic acids can be used as metal-free catalysts.
For example, trifluoroacetic acid, trifluoromethanesulphonic acid, p-toluenesulphonic acid, trialkylammonium compounds R3NH+X− or bases, such as, for example, trialkylamines NR3 can be used as organic acids.
The process according to the invention can be carried out at atmospheric pressure or reduced pressure, preferably between 1 and 600 mbar, particularly preferably between 5 and 400 mbar, very particularly preferably between 5 and 200 mbar.
The process according to the invention can be carried out in the temperature range between 50° C. and 200° C., preferably between 70° C. and 180° C., particularly preferably between 90° C. and 150° C.
Substances which promote the transport of water through the product by formation of azeotropic mixtures can be added to the reaction mixture before or during the reaction. The corresponding substances may be cyclic or straight-chain aliphatics, aromatics, mixed aromatic-aliphatic compounds, ethers, alcohols or acids. For example, hexane, cyclohexane, benzene, toluene, ethanol, propanol, isopropanol, butanol, ethylene glycol, tetrahydrofuran, dioxane, formic acid, acetic acid, ethyl acetate or dimethylformamide may be used.
The reaction can be carried out continuously or batchwise.
In the process according to the invention, additives can be added to the reaction mixture before, during or after the reaction. The additives can preferably be added before the reaction. The additives may reduce electrophilic or nucleophilic cleavage of the Q—S bond in formula I.
For avoiding condensation reactions, it may be advantageous to carry out the reaction in an anhydrous environment, ideally in an inert gas atmosphere.
The organosilicon compounds according to the invention can be used as adhesion promoters between inorganic materials (for example glass fibres, metals, oxidic fillers, silicas) and organic polymers (for example thermosetting plastics, thermoplastics, elastomers) or as crosslinking agents and surface-modifying agents. The organosilicon compounds according to the invention can be used as coupling reagents in filled rubber mixtures, for example tyre treads.
The invention furthermore relates to rubber mixtures which are characterized in that they contain rubber, filler, such as, for example, precipitated silica, optionally further rubber auxiliaries, and at least one of the organosilicon compounds according to the invention and of the general formula (I).
The organosilicon compounds according to the invention and of the general formula (I) can be used in amounts of from 0.1 to 50% by weight, preferably from 0.1 to 25% by weight, particularly preferably from 1 to 20% by weight, based on the amount of the rubber used.
The addition of the organosilicon compounds according to the invention and of the general formula (I) and the addition of the fillers can be effected at material temperatures of from 100 to 200° C. However, they can also be effected at lower temperatures of from 40 to 100° C., for example together with further rubber auxiliaries.
The organosilicon compounds according to the invention can be added to the mixing process both in pure form and after application to an inert organic or inorganic support, and after a preliminary reaction with an organic or inorganic support. Preferred support materials may be precipitated or pyrogenic silicas, waxes, thermoplastics, natural or synthetic silicates, natural or synthetic oxides, preferably alumina, or carbon blacks. Furthermore, the organosilicon compounds according to the invention can also be added to the mixing process after preliminary reaction with the filler to be used.
The organosilicon compounds according to the invention can be added to the mixing process after being physically mixed with an organic substance or with a mixture of organic substances. The organic substance or the mixture of organic substances may contain polymers or oligomers. The polymers or oligomers may be heteroatom-containing polymers or oligomers, for example ethylene-vinyl alcohol, ethylene-vinyl acetate, polyvinyl acetate and/or polyvinyl alcohols. Polymers or oligomers may be saturated or unsaturated elastomers, preferably emulsion SBR and/or solution SBR. The melting point of the mixture of organosilicon compounds according to the invention and organic substance or a mixture of organic substances may be between 50 and 200° C., preferably between 70 and 180° C., particularly preferably between 70 and 150° C., very particularly preferably between 70 and 130° C., exceptionally preferably between 90 and 110° C. The organic substance or the mixture of organic substances may contain at least one olefinic wax and/or long-chain carboxylic acids.
Fillers which may be used for the rubber mixtures according to the invention are the following fillers:
Amorphous silicas, prepared by precipitation of solutions of silicates (precipitated silicas), having BET surface areas of from 20 to 400 m2/g in amounts of from 5 to 150 parts by weight, based in each case on 100 parts of rubber, can preferably be used.
Said fillers can be used alone or as a mixture. In a particularly preferred embodiment of the process, from 10 to 150 parts by weight of light fillers, optionally together with from 0 to 100 parts by weight of carbon black, and from 1 to 20 parts by weight of a compound of the organosilicon compounds according to the invention, based in each case on 100 parts by weight of rubber, can be used for the preparation of the mixtures.
In addition to natural rubber, synthetic rubbers are also suitable for the preparation of the rubber mixtures according to the invention. Preferred synthetic rubbers are described, for example, in W. Hofmann, Kautschuktechnologie [Rubber technology], Genter Verlag, Stuttgart 1980. They comprise, inter alia,
The rubber vulcanizates according to the invention may contain further rubber auxiliaries, such as reaction accelerators, antiageing agents, heat stabilizers, light stabilizers, antiozonants, processing auxiliaries, plasticizers, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retardants, metal oxides and activators, such as diphenylguanidine, triethanolamine, polyethylene glycol, alkoxy-terminated polyethylene glycol alkyl-O—(CH2—CH2—O)yI—H where yI=2-25, preferably yI=2-15, particularly preferably yI=3-10, very particularly preferably yI=3-6, or hexanetriol, which are known to the rubber industry.
The vulcanization of the rubber mixtures according to the invention can be carried out without addition of nitrogen-containing activators, such as, for example, guanidines and amines. In a preferred embodiment, the rubber vulcanizate may be free of guanidine derivatives.
The rubber auxiliaries can be used in known amounts which depend, inter alia, on the intended use. Customary amounts may be, for example, amounts of from 0.1 to 50% by weight, based on rubber. Sulphur or sulphur-donating substances may be used as crosslinking agents. Over and above this, the rubber mixtures according to the invention may contain vulcanization accelerators. Examples of suitable vulcanization accelerators may be mercaptobenzothiazoles, sulphenamides, guanidines, thiurams, dithiocarbamates, thioureas and thiocarbonates. The vulcanization accelerators and sulphur can be used in amounts of from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, based on rubber.
The vulcanization of the rubber mixtures according to the invention can be effected at temperatures of from 100 to 200° C., preferably from 130 to 180° C., optionally under pressure of from 10 to 200 bar. The mixing of the rubbers with the filler, optionally rubber auxiliaries and the organosilicon compound according to the invention can be carried out in known mixing units, such as roll mills, internal mixers and mixing extruders.
The rubber mixtures according to the invention can be used for the production of mouldings, for example for the production of pneumatic tyres, tyre treads, cable sheaths, hoses, drive belts, conveyor belts, roll coverings, tyres, shoe soles, sealing rings and damping elements.
The organosilicon compounds according to the invention have the advantage that no readily volatile alcohol, usually methanol or ethanol, is liberated during the hydrolysis of the Si—O—R bonds and at the same time the reactivity with the inorganic filler and the organic polymer is still high. The processing properties of the raw mixtures and the dynamic properties of the vulcanizates give a very good, balanced set of values overall.
The HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N used is synthesized from HS—CH2—CH2—CH2—Si(O—CH2—CH3)3 with triethanolamine in the presence of Ti(OBu)4 at temperatures of 110-130° C. under reduced pressure and in a reaction time of 180-360 min by transesterification in the absence of a solvent.
The HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N contains between 1 and 6% by weight of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, depending on the quality of the HS—CH2—CH2—CH2—Si(O—CH2—CH3)3 used.
Cl—CH2—CH2—CH2—Si(O—CH2—CH3)3 is present as a secondary constituent in the HS—CH2—CH2—CH2—Si(O—CH2—CH3)3 used and is converted into Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N under the reaction conditions.
Preparation of CH3—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
38.5 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 10 min at 0° C. 29.4 g of acetyl chloride are added dropwise to the mixture at a temperature between −5° C. and 0° C. After stirring for 60 min at between 0° and room temperature, the suspension formed is heated to 80° C. for 3 h. Thereafter, the suspension is filtered, the filtercake is washed with toluene, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 114 g of viscous product are obtained. According to NMR analyses, the product contains 87 mol % of CH3—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 9 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 3 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Preparation of C7H15—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
40.6 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 10 min at 0° C. 65.3 g of octanoyl chloride are added dropwise to the mixture at a temperature between −5° C. and 0° C. After stirring for 60 min at between 0° and room temperature, the suspension obtained is filtered, the filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 141.6 g of viscous product are obtained. According to NMR analyses, the product contains 93 mol % of C7H15—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 5 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 2 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Preparation of C11H23—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
38.5 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 10 min at 0° C. 83.2 g of dodecanoyl chloride are added dropwise to the mixture at a temperature between −5° C. and 0° C. After stirring for 15 h at between 0° and room temperature, the suspension obtained is filtered, the filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 162.4 g of viscous product are obtained. According to NMR analyses, the product contains >86 mol % of C11H23—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 9 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 3 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Preparation of C15H31—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
38.5 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 15 min at 0° C. 104.5 g of palmitoyl chloride are added dropwise to the mixture at a temperature between −10° C. and 0° C. After stirring for 18 h at room temperature the suspension obtained is filtered, the filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 186.3 g of viscous product are obtained. According to NMR analyses, the product contains 88 mol % of C15H31—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 8 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 3 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Preparation of N(CH2CH2—O)3Si(CH2)3S—C(O)—C4H8—C(O)—S(CH2)3Si(O—CH2CH2)3N
40.5 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 15 min at 0° C. 53.5 g of adipoyl dichloride are added dropwise to the mixture at a temperature between −10° C. and 0° C. After stirring for 2 h at room temperature, the suspension formed is heated to 70° C. for 2 h. The suspension obtained is filtered, the filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 98.4 g of viscous product are obtained. According to NMR analyses, the product contains 93 mol % of N(CH2CH2—O)3Si(CH2)3S—C(O)—C4H8—C(O)—S(CH2)3Si(O—CH2CH2)3N, 2 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 4 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Preparation of N(CH2CH2—O)3Si(CH2)3S—C(O)—C10H20—C(O)—S(CH2)3Si(O—CH2CH2)3N
38.5 g of triethylamine are added at 0° C. to a solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene. The mixture is stirred for 15 min at 0° C. 50.8 g of dodecanedioyl chloride are added dropwise to the mixture at a temperature between −10° C. and 0° C. After stirring for 2 h at room temperature, the suspension formed is heated to 70° C. for 3 h. The suspension obtained is cooled and filtered, the filtercake is washed with toluene, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 132.4 g of viscous product are obtained. According to NMR analyses, the product contains 91 mol % of N(CH2CH2—O)3Si(CH2)3S—C(O)—C11H20—C(O)—S(CH2)3Si(O—CH2CH2)3N, 2 mol % of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 4 mol % of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, based on the silicon-containing constituents.
Rubber Investigations
The formulation used for the rubber mixtures is stated in Table 1 below. There, the unit phr denotes parts by weight based on 100 parts of the raw rubber used. The organosilicon compounds according to the invention are used in equimolar amounts, i.e. in an amount of substance identical to the amount of the silane of Comparative Example 1. The following coupling agents are investigated:
The general process for the preparation of rubber mixtures and the vulcanizates thereof is described in the book: “Rubber Technology Handbook”, W. Hofmann, Hanser Verlag 1994.
The polymer VSL 5025-1 is a solution-polymerized SBR copolymer from Bayer AG, having a styrene content of 25% by weight and a butadiene content of 75% by weight. The copolymer contains 37.5 phr of oil and has a Mooney viscosity (ML 1+4/100° C.) of 50.
The polymer Buna CB 24 is a cis-1,4-polybutadiene (neodymium grade) from Bayer AG, having a cis-1,4 content of at least 96% and a Mooney viscosity of 44±5.
Ultrasil 7000 GR is a readily dispersible silica from Degussa AG and has a BET surface area of 170 m2/g.
Naftolen ZD from Chemetall is used as an aromatic oil, Vulkanox 4020 is PPD from Bayer AG and Protektor G3108 is an antiozonant wax from Paramelt B.V. Vulkacit CZ (CBS) is a commercial product from Bayer AG. Perkacit TBzTD (tetrabenzylthiuram tetrasulphide) is a product from Flexsys N.V.
The rubber mixtures are prepared in an internal mixer according to the mixing method in Table 2.
The methods for rubber testing are listed in Table 3.
Table 4 shows the results of the rubber test. The mixtures are vulcanized to t99% of the rheometer test but for not longer than 30 min at 165° C.
The results of Table 4 show that the viscosity of the mixture can be reduced by lengthening the blocking group from acetyl through octanoyl to palmityl. Comparison of the mixture 2 with the mixture 3 shows that the viscosity too is reduced by the modification of the silane. Thus, the silanes according to the invention are distinguished by better processability compared with the prior art.
On consideration of the vulcanizate results, it is evident that both the ball rebound and the heat build-up of the mixtures 3, 4 and 5 comprising the silanes according to the invention are substantially improved compared with the mixtures 1 and 2.
Thus, it is found that advantages both in the processability and in the dynamic behaviour can be produced exclusively by the combination of the modification of the silica-active coupling group and simultaneous blocking of the sulphur group.
Both the higher ball rebound and the lower heat build-up indicate that tyre treads comprising the silanes according to the invention lead to a lower rolling resistance and hence fuel consumption. In addition, the dynamic heat build-up is lower, which increases the longevity of the tyre. By means of the organosilicon compounds according to the invention, the processability of the rubber mixture and at the same time the dynamic behaviour can therefore be improved.
In addition, the organosilicon compounds according to the invention are distinguished in that no volatile alcohol is liberated during the mixing.
Preparation of C4H9—NH—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
70 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 44.5 g of O═C═N—C4H9 (from Sigma-Aldrich) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 24 h. Stirring is then effected for 5 h at 60° C. The solution obtained is freed from volatile constituents on a rotary evaporator at 80° C. in vacuo. 100 g of a viscous dark, orange oil are obtained.
Preparation of C8H17—NH—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
40 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 25 g of O═C═N—C8H17 (from Sigma-Aldrich) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 24 h. Stirring is then effected for 5 h at 60° C. The solution obtained is freed from volatile constituents on a rotary evaporator at 80° C. in vacuo. 65 g of a viscous yellow oil are obtained.
Preparation of C6H5—NH—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
75 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 55 g of O═C═N—C6H5 (from VWR) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 48 h. A colourless precipitate forms. The suspension obtained is filtered and the filtercake is washed with 500 ml of pentane. The filtercake is then dried at 80-90° C. in vacuo. 110 g of a colourless solid are obtained.
Preparation of C4H9—NH—C(S)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
70 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 50 g of S═C═N—C4H9 (from KMF-Laborchemie) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 48 h. Stirring is then effected for 5 h at 60° C. The solution obtained is freed from volatile constituents on a rotary evaporator at 80° C. in vacuo. 102 g of a viscous orange-brown oil are obtained.
Preparation of C8H17—NH—C(S)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
30 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 25 g of S═C═N—C8H17 (from KMF-Laborchemie) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 24 h. Stirring is then effected for 5 h at 60° C. The solution obtained is freed from volatile constituents on a rotary evaporator at 80° C. in vacuo. 55 g of a viscous yellow-orange oil are obtained.
Preparation of C6H5—NH—C(S)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
75 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N and 50 g of S═C═N—C6H5 (from VWR) are combined in 100 g of toluene (Seccosolv) under inert gas at 25° C. in a flask and are stirred for 48 h. A wax-coloured precipitate, which does not dissolve even in an additional 235 g of toluene, forms. Stirring is then effected for 5 h at 60° C. The suspension obtained is filtered and the filtercake is washed with 700 ml of pentane. The filtercake is then dried at 80-90° C. in vacuo. 100 g of a colourless solid are obtained.
Preparation of Me3Si—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
44.5 g of triethylamine are added at 1° C. to a cooled solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene (Seccosolv). The mixture is stirred for 10 min at 3-6° C. 47.8 g of trimethylsilyl chloride are added dropwise to the mixture at a temperature between 1° C. and 10° C. After stirring for 60 min, the suspension formed is heated to 70° C. for 5 h, then cooled and then filtered. The filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 129 g of orange viscous product are obtained.
Preparation of C16H33—Si—[S—CH2—CH2—CH2—Si(O—CH2—CH2)3N]3
44.5 g of triethylamine are added at 0° C. to a cooled solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH2—CH2)3N in 1000 ml of toluene (Seccosolv). The mixture is stirred for 10 min at 2-4° C. 46.8 g of C16H33—SiCl3 are added dropwise to the mixture at a temperature between 2° C. and 10° C. After stirring for 60 min, the suspension formed is heated to 70° C. for 5 h, then cooled and then filtered. The filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 130 g of orange viscous product are obtained.
Preparation of C6H5—(C═O)—S—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N
36 g of triethylamine are added at 2° C. to a cooled solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N in 1000 ml of toluene (Seccosolv). The mixture is stirred for 10 min at 2-4° C. 49.2 g of benzoyl chloride are added dropwise to the mixture at a temperature between 2° C. and 10° C. After stirring for 60 min, the suspension formed is heated to 65° C. for 5 h, then cooled and then filtered. The filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 138 g of orange viscous product are obtained.
Preparation of C7H15—(C═O)—S—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N
35.4 g of triethylamine are added at 3° C. to a cooled solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N in 1000 ml of toluene (Seccosolv). The mixture is stirred for 10 min at 2-4° C. 56.9 g of octanoyl chloride are added dropwise to the mixture at a temperature between 20° C. and 100° C. After stirring for 60 min, the suspension formed is heated to 65-700° C. for 5 h, then cooled and then filtered. The filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 150 g of orange viscous product are obtained.
Preparation of C11H23—(C═O)—S—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N
35.4 g of triethylamine are added at 3° C. to a cooled solution of 100 g of HS—CH2—CH2—CH2—Si(O—CH(CH3)—CH2)3N in 1000 ml of toluene (Seccosolv). The mixture is stirred for 10 min at 2-4° C. 76.6 g of dodecanoyl chloride are added dropwise to the mixture at a temperature between 2° C. and 10° C. After stirring for 60 min, the suspension formed is heated to 68-72° C. for 5 h, then cooled and then filtered. The filtercake is washed, the filtrates obtained are combined and the solvent is removed on a rotary evaporator. 163 g of orange viscous product are obtained.
Rubber Investigations
The formulation used for the rubber mixtures is stated in Table 5 below. There, the unit phr denotes parts by weight based on 100 parts of the raw rubber used. The organosilicon compounds according to the invention are used in equimolar amounts, i.e. in an amount of substance identical to the amount of the silane of Comparative Example 1.
The rubber mixtures are prepared in an internal mixer according to the mixing method in Table 6. Table 3 lists the methods for rubber testing.
The results of the rubber investigations are summarized in Table 7.
As is evident from the results, mixtures 7 to 9 comprising the organosilicon compounds according to the invention have a lower viscosity and hence better processing properties. At the same time, they also have a smaller heat build-up and permanent set and hence advantageous dynamic properties.
Preparation of C7H15—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
100 g of S-[3-(triethoxysilyl)propyl] octanethioate [CAS No. 220727-26-4], 41 g of triethanolamine (from BASF AG) and 1 g of NaOH are combined under inert gas at 25° C. in an appartus and are heated to 130° C. Thereafter, stirring is effected for 3 h at 130° C. and 50-200 mbar and the ethanol liberated is distilled off. 125 g of product are obtained.
Preparation of C6H5—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
91 g of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 50 g of thiobenzoic acid and 250 g of dry DMF are combined under inert gas at 25° C. in a flask. 36.5 g of triethylamine are added dropwise to the mixture, and the solution obtained is stirred for 120 min at room temperature and then for 240 min at 140° C. Cooling is effected and 300 ml of dry toluene are added. The precipitate is separated off by filtration and washed with toluene, and the filtrate is as far as possible freed from the solvent on a rotary evaporator. 142 g of a viscous, dark red product are obtained.
Preparation of C6H5—C(O)—S—CH2—CH2—CH2—Si(O—CH2—CH2)3N
91 g of Cl—CH2—CH2—CH2—Si(O—CH2—CH2)3N, 50 g of thiobenzoic acid and 300 g of dry toluene are combined under inert gas at 25° C. in a flask. 36.5 g of triethylamine are added dropwise to the mixture, and the solution obtained is stirred for 120 min at room temperature and then for 240 min at 108° C. The suspension is cooled, the precipitate is separated off by filtration and washed with toluene, and the filtrate is freed from the solvent on a rotary evaporator. 127 g of a viscous, dark red product are obtained.
All references cited herein are fully incorporated by reference. Having now fully described the invention, it will be understood by those of skill in the art that the invention may be practiced within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof.
Number | Date | Country | Kind |
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10 2005 038 791.8 | Aug 2005 | DE | national |