EP1642840A1 - Cork having a reduced release of trichloranisol and methods of manufacture - Google Patents

Abstract

Bottle cork (I) comprises a surface, which is coated with an elastomer comprising uncomplexed alpha -, beta or gamma cyclodextrin or its derivative. Independent claims are also included for the preparations of (I).

Description

The invention relates to a bottle cap with a reduced Trichloranisolfreisetzung and a process for its preparation.

The cork taste of wine is a consequence of the mold-produced, halogen-containing, low molecular weight aromatics, most notably the musty smelling extremely odorous 2,4,6-trichloroanisole. In EP 0 210 261 A, bottle corks are impregnated with a two-component silicone rubber in a vacuum process. The advantage of this method is to provide inferior quality corks with improved sealing properties, as well as to reduce the extraction of aromatic cork ingredients affecting the taste of the beverage, such as trichloroanisole, and thereby enhance the cork. In EP 1 135 301 B1, bottle corks are provided on the side facing the drinks with a slice of silicone elastomer which is intended to prevent the migration of trichloroanisole from the bottle cork into the beverage. The disadvantage of these bottle corks is that the silicone elastomer absorbs low molecular weight aromatic compounds well and thus can not act as a barrier for such substances. On the contrary, the effect of the processes described in the literature is based on the fact that for the aromatic compounds a chemical equilibrium is established between the phases silicone elastomer and liquid, in which a part of the aromatic compound is permanently absorbed in the silicone.

From DE 10 147 626 A1 a process for the impregnation of bottle corks is known in which the bottle corks with elastomeric silicone rubber compositions crosslinkable to the organopolysiloxanes with 1.0 to 2.0 wt .-% Si-bonded hydrogen have, be impregnated. Even with these bottle corks, the above-mentioned disadvantage persists.

It was the object to provide a cork-containing bottle cork having a reduced Trichloranisolfreisetzung.

This object is achieved in that a surface of the bottle cork is provided with a coating of an elastomer, characterized in that the elastomer contains uncomplexed α-, β- or γ-cyclodextrin or uncomplexed α-, β- or γ-cyclodextrin derivative.

Cork-containing bottle corks are preferably cork stoppers for closing beverage bottles, such as wine bottles.

The α-, β- or γ-cyclodextrin or an α-, β- or γ-cyclodextrin derivative may be all previously known cyclodextrin (derivatives), it may also be a mixture of said substances.

Preferably, it is α-, β- or γ-cyclodextrin or a cyclodextrin derivative selected from the group of alkylated, hydroxyalkylated, acylated and sulfoalkyl ether substituted α-, β- or γ-cyclodextrins.

Preference is given to the non-derivatized α-, β- or γ-cyclodextrins, in particular the γ-cyclodextrin.

In the following, the term cyclodextrin (CD) also includes cyclodextrin derivatives.

The elastomer preferably contains 0.01 to 40% by weight of CD, preferably 10 to 25% by weight. The wt .-% indication refers to the total weight of the elastomer.

Due to the content of uncomplexed CD in the elastomer, a significantly larger proportion of trichloroanisole is absorbed than is known from the prior art.

In principle, any elastomer containing uncomplexed CD is suitable as a coating for a cork. A CD-containing elastomer is obtainable by incorporating CD in the elastomer. This can happen before, during or after the production of the elastomer, depending on the type of elastomer. The incorporation of the CD is preferably carried out in a manner known for the incorporation of a filler in the elastomer.

1. (1) Organopolysiloxane, die Reste mit aliphatischen Kohlenstoff-Kohlenstoff-Mehrfachbindungen aufweisen,
2. (2) Organopolysiloxane mit Si-gebundenen Wasserstoffatomen,
3. (3) die Anlagerung von Si-gebundenem Wasserstoff an aliphatische Mehrfachbindungen fördernde Katalysatoren und gegebenenfalls
4. (4) die Anlagerung von Si-gebundenem Wasserstoff an aliphatische Mehrfachbindungen verzögernde Mittel, sogenannte Inhibitoren,
   oder
5. (5) Organopolysiloxane, die Reste mit aliphatischen Kohlenstoff-Kohlenstoff-Mehrfachbindungen aufweisen, und
6. (6) die radikalische Vernetzung von aliphatische Mehr- und Einfachbindungen fördernden Peroxiden,
   oder
7. (7) Organopolysiloxane, die Reste mit Hydroxylgruppen aufweisen,
8. (8) als Vernetzer Siloxane mit Si-gebundenen, hydrolysierbaren Gruppen und
9. (9) die Hydrolyse dieser Gruppen unter Ausbildung von Si-O-Si Brücken fördernde Katalysatoren.

The elastomer into which the CD is incorporated is preferably available from a crosslinkable silicone rubber composition containing

1. (1) organopolysiloxanes having radicals having aliphatic carbon-carbon multiple bonds,
2. (2) organopolysiloxanes having Si-bonded hydrogen atoms,
3. (3) the addition of Si-bonded hydrogen to aliphatic multiple bonds promoting catalysts and optionally
4. (4) the addition of Si-bonded hydrogen to aliphatic multiple bonds delaying agents, so-called inhibitors,
   or
5. (5) Organopolysiloxanes having radicals with aliphatic carbon-carbon multiple bonds, and
6. (6) the free-radical crosslinking of aliphatic poly- and single-bond promoters peroxides,
   or
7. (7) organopolysiloxanes having radicals with hydroxyl groups,
8. (8) as crosslinkers siloxanes with Si-bonded, hydrolyzable groups and
9. (9) the hydrolysis of these groups to form Si-O-Si bridge promoting catalysts.

The organopolysiloxanes used according to the invention are commercially available products or can be prepared by processes customary in silicon chemistry.

wobei R gleich oder verschieden ist, einen einwertigen, gegebenenfalls substituierten Kohlenwasserstoffrest mit 1 bis 18 Kohlenstoffatom(en) je Rest und
R¹ gleich oder verschieden ist, einen einwertigen Kohlenwasserstoffrest mit terminaler, aliphatischer Kohlenstoff-Kohlenstoff-Mehrfachbindung mit 2 bis 8 Kohlenstoffatomen je Rest bedeutet,
a 0, 1, 2 oder 3,
b 0, 1 oder 2
und die Summe a+b<3 ist,
mit der Maßgabe, daß die Organopolysiloxane der Formel (I) pro Molekül mindestens 2 Reste R¹ enthalten, verwendet.As organopolysiloxanes (1) are preferably linear or branched organopolysiloxanes of units of the general formula $${\mathrm{R}}_{\mathrm{a}}{{\mathrm{R}}^1}_{\mathrm{b}}\mathrm{S}\mathrm{i}{\mathrm{O}}_{\frac{4-\mathrm{a}-\mathrm{b}}{2}}$$

wherein R is the same or different, a monovalent, optionally substituted hydrocarbon radical having 1 to 18 carbon atoms per radical and
R ^{1 is the} same or different, is a monovalent hydrocarbon radical having a terminal, aliphatic carbon-carbon multiple bond having 2 to 8 carbon atoms per radical,
a 0, 1, 2 or 3,
b 0, 1 or 2
and the sum a + b <3,
with the proviso that the organopolysiloxanes of the formula (I) contain at least 2 radicals R ¹ per molecule.

R is preferably a hydrocarbon radical free of aliphatic carbon-carbon multiple bonds. Examples of radicals R are alkyl radicals, such as the methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, , neo-pentyl, tert-pentyl, hexyl, such as the n-hexyl radical, heptyl radicals, such as the n-heptyl radical, octyl radicals, such as the n-octyl radical and iso-octyl radicals, such as the 2,2,4-trimethylpentyl radical, nonyl radicals, such as the n-nonyl radical, decyl radicals, such as n- Decyl, dodecyl, such as the n-dodecyl, and octadecyl, such as the n-octadecyl; Cycloalkyl radicals such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; Aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radicals; Alkaryl radicals, such as o-, m-, p-tolyl radicals, xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical, the α- and the β-phenylethyl radical.

Examples of substituted radicals R are haloalkyl radicals, such as the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2 ', 2', 2'-hexafluoroisopropyl radical, the heptafluoroisopropyl radical and haloaryl radicals, such as the o-, m- and p-chlorophenyl

The radical R is preferably a monovalent hydrocarbon radical having 1 to 6 carbon atoms, the methyl radical being particularly preferred.

Examples of radicals R ¹ are alkenyl radicals, such as the vinyl, 5-hexenyl, cyclohexenyl, 1-propenyl, allyl, 3-butenyl and 4-pentenyl radicals, and alkynyl radicals, such as ethynyl, propargyl and 1 -Propinylrest.

The radical R ¹ is preferably alkenyl radicals, with the vinyl radical being particularly preferred.

One type of organopolysiloxane (1) or various types of organopolysiloxanes (1) can be used.

wobei R und R¹ die oben dafür angegebene Bedeutung haben
g 0, 1, 2 oder 3, bevorzugt 1, bedeutet,
m 0 oder eine ganze Zahl von 1 bis 5000 ist und
n eine ganze Zahl von 70 bis 10 000 ist,
mit der Maßgabe, daß die Organopolysiloxane der Formel (II) pro Molekül mindestens 2 Reste R¹ enthalten.Preferred organopolysiloxanes (1) are those of the general formula $${{\mathrm{R}}^1}_{\mathrm{G}}{\mathrm{R}}_{3-\mathrm{G}}\mathrm{SiO}{\left({\mathrm{SiR}}_2\mathrm{O}\right)}_{\mathrm{n}}{\left(\mathrm{SiR}{\mathrm{R}}^1\mathrm{O}\right)}_{\mathrm{m}}{\mathrm{SiR}}_{3-\mathrm{G}}{{\mathrm{R}}^1}_{\mathrm{G}}$$

where R and R ^{1 have} the meaning given above
g is 0, 1, 2 or 3, preferably 1,
m is 0 or an integer from 1 to 5000 and
n is an integer from 70 to 10,000,
with the proviso that the organopolysiloxanes of the formula (II) contain at least 2 radicals R ¹ per molecule.

In the context of this invention formula (II) should be understood to mean that n units - (SiR ₂ O) - and m units - (SiRR ₁ O) - can be distributed in any desired manner, for example as a block or randomly, in the organopolysiloxane molecule.

The organopolysiloxanes (1) have an average viscosity of preferably 100 to 100,000,000 mPa.s at 25 ° C.

wobei
R die oben dafür angegebene Bedeutung hat,
e 0, 1, 2 oder 3,
f 0, 1 oder 2
und die Summe von e+f<3 ist,
mit der Maßgabe, daß die Organopolysiloxane der Formel (III) 1,0 bis 2,0 Gew.-% Si-gebundenen Wasserstoff aufweisen, verwendet.The crosslinkers used are organopolysiloxanes (2) in the addition crosslinking of the silicone rubber compositions according to the invention.
Organopolysiloxanes (2) are preferably linear, cyclic or branched organopolysiloxanes of units of the general formula $${\mathrm{R}}_{\mathrm{e}}{\mathrm{H}}_{\mathrm{f}}\mathrm{S}\mathrm{i}{\mathrm{O}}_{\frac{4-\mathrm{e}-\mathrm{f}}{2}}$$

in which
R has the meaning given above,
e 0, 1, 2 or 3,
f 0, 1 or 2
and the sum of e + f <3,
with the proviso that the organopolysiloxanes of the formula (III) have 1.0 to 2.0 wt .-% Si-bonded hydrogen used.

Preferred organopolysiloxanes (2) are those of the general formula

H _h R _3-h SiO (SiR ₂ O) _o (SiR ₂ -x H _x O) _p SiR _{3 -h} H _h (IV)

where R has the meaning given above,
h is 0, 1 or 2, preferably 0,
o is 0 or an integer from 1 to 1,000, preferably 0,
p is an integer from 1 to 1,000, preferably 40 to 70 and
x is 1 or 2, preferably 1,
with the proviso that the organopolysiloxanes of the formula (IV) have 1.0 to 2.0 wt .-%, preferably 1.5 to 1.7 wt .-%, Si-bonded hydrogen used.

In the context of this invention, formula (IV) should be understood as meaning that o units - (SiR ₂ O) - and p units (SiR ₂ -x H _x O) - be distributed in any desired manner, for example as a block or randomly, in the organopolysiloxane molecule can.
Examples of organopolysiloxanes (2) are, in particular, copolymers of dimethylhydrogensiloxane, methylhydrogensiloxane, dimethylsiloxane and trimethylsiloxane units, copolymers of trimethylsiloxane, dimethylhydrogensiloxane and methylhydrogensiloxane units, copolymers of trimethylsiloxane, dimethylsiloxane and methylhydrogensiloxane units, copolymers of methylhydrogensiloxane and trimethylsiloxane units, Copolymers of methylhydrogensiloxane, diphenylsiloxane and trimethylsiloxane units, copolymers of methylhydrogensiloxane, dimethylhydrogensiloxane and diphenylsiloxane units, copolymers of methylhydrogensiloxane, phenylmethylsiloxane, trimethylsiloxane and / or dimethylhydrogensiloxane units, copolymers of methylhydrogensiloxane, dimethylsiloxane, diphenylsiloxane, trimethylsiloxane and / or dimethylhydrogensiloxane units and copolymers of dimethylhydrogensiloxane, trimethylsiloxane, phenylhydro gensiloxan, dimethylsiloxane and / or phenylmethylsiloxane units.

One type of organopolysiloxane (2) or various types of organopolysiloxanes (2) can be used.

The organopolysiloxanes (2) have an average viscosity of preferably 10 to 100,000 mPa.s at 25 ° C, preferably 10 to 500 mPa.s at 25 ° C, particularly preferably 10 to 30 mPa.s at 25 ° C.

In addition to the organopolysiloxanes (2) rich in Si-bonded hydrogen, the compositions according to the invention can also be organopolysiloxanes (2 ') of the general formula

H _v R _3-v SiO (SiR ₂ O) _s (SiRHO) _t SiR ₃ -v H _v (IV ')

where R has the meaning given above,
v 0, 1 or 2,
s 0 or an integer from 1 to 1,000
t is 0 or an integer from 1 to 1,000,
with the proviso that the organopolysiloxanes of the formula (IV ') contain at least 2 Si-bonded hydrogen atoms per molecule but contain less than 1.0% by weight of Si-bonded hydrogen.

With v = 1 and t = 0 in formula (IV ') are, for example, α, ω-dihydrogenorganopolysiloxanes, which act as chain extenders.

The organopolysiloxanes (2 ') have an average viscosity of preferably 10 to 100,000 mPa.s at 25 ° C, preferably 10 to 500 mPa.s at 25 ° C.

Organopolysiloxane (2) is preferably used in the silicone rubber compositions according to the invention in amounts of from 0.01 to 20% by weight, based on the total weight of the organopolysiloxanes (1).

Organopolysiloxane (2 ') is preferably used in the silicone rubber compositions of the invention in amounts of from 0 to 100% by weight, based on the total weight of the organopolysiloxanes (1) used.

As the addition of Si-bonded hydrogen to aliphatic multiple bond promoting catalysts (3), the same catalysts can be used in the silicone rubber compositions according to the invention, which could also be used to promote the addition of Si-bonded hydrogen to aliphatic multiple bond. The catalysts are preferably a metal from the group of platinum metals or a compound or a complex from the group of platinum metals. Examples of such catalysts are metallic and finely divided platinum, which may be supported on supports such as silica, alumina or activated carbon, compounds or complexes of platinum such as platinum halides, eg PtCl ₄ , H ₂ PtCl ₆ .6H ₂ O, Na ₂ PtCl ₄ * 4H ₂ O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alcoholate complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H ₂ PtCl ₆ * 6H ₂ O and cyclohexanone, platinum-vinyl-siloxane complexes such as platinum-1,3-divinyl-1,1,3,3-tetra-methyl-disiloxane complexes with or without detectable inorganic halogenated content, bis (gamma-picoline) platinum dichloride, trimethylenedipyridine platinum dichloride, dicyclopentadiene platinum dichloride, dimethyl sulfoxydethylenepatin (II) di chloride, cyclooctadiene platinum dichloride, norbornadiene platinum dichloride, gamma-picoline platinum dichloride, cyclopentadiene platinum dichloride, and reaction products of platinum tetrachloride with Olefin and primary amine or secondary amine or primary and secondary amine, such as the reaction product of dissolved in 1-octene platinum tetrachloride with sec-butylamine or ammonium-platinum complexes.

The catalyst (3) is preferably used in the silicone rubber compositions of the invention in amounts of from 0.001 to 0.1% by weight, calculated in each case as elemental platinum and based on the total weight of the organopolysiloxanes (1) and (2).

As inhibitors (4), it is also possible with the silicone rubber compositions according to the invention to use all inhibitors which hitherto could also be used for the same purpose.

Examples of inhibitors (4) are 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, benzotriazole, dialkylformamides, alkylthioureas, methyl ethyl ketoxime, organic or organosilicon compounds having a boiling point of at least 25 ° C. at 1012 mbar (abs.) and at least one aliphatic triple bond such as 1-ethynylcyclohexan-1-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyne-3-ol, 2,5-dimethyl-3-hexyne-2 , 5-diol and 3,5-dimethyl-1-hexyn-3-ol, 3,7-dimethyl-oct-1-yn-6-en-3-ol, a mixture of diallyl maleate and vinyl acetate, maleic acid monoesters, and inhibitors as the compound of formula HC = CC (CH ₃ ) (OH) -CH ₂ -CH ₂ -CH = C (CH ₃ ) ₂ , commercially available under the trade name "dehydrolinalool" from BASF.

The inhibitor (4) is used in amounts of preferably 0.001 to 10 wt .-%, based on the total weight of the organopolysiloxanes (1) and (2).

For the organopolysiloxanes (5), their preferred and particularly preferred embodiments and examples, the corresponding statements on the organopolysiloxanes (1) apply.

The peroxides (6) used are organic peroxides which serve as a source of free radicals. Examples of organic peroxides include acyl peroxides such as dibenzoyl peroxide, bis (4-chlorobenzoyl) peroxide, bis (2,4-dichlorobenzoyl) peroxide and bis (4-methylbenzoyl) peroxide; Alkyl peroxides and aryl peroxides such as di-tert-butyl peroxide, 2,5-bis (tert-butylperoxy) -2,5-dimethylhexane, dicumyl peroxide and 1,3-bis (tert-butylperoxy-isopropyl) -benzene; Perketals such as 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane; Peresters such as diacetyl peroxydicarbonate, tert-butyl perbenzoate, tert-butyl peroxy-isopropyl carbonate, tert-butyl peroxy isononanoate, dicyclohexyl peroxydicarbonate and 2,5-dimethylhexane-2,5-diperbenzoate.

It may be a kind of organic peroxide, it may also be a mixture of at least two different types of organic peroxide used.

Preferably, peroxides are used in amounts of 0.01 to 5.0 wt .-%, preferably 0.2 to 1.2 wt .-%, each based on the total weight of the diorganopolysiloxanes used, in the compositions of the invention.

As organopolysiloxanes (7) are preferably those of the general formula

XR ₂ SiO (R ₂ SiO) _n SiR ₂ X (V)

where R is identical or different, monovalent, optionally substituted hydrocarbon radicals having 1 to 18 carbon atoms per radical,
X is a hydroxyl group and
n is an integer of at least 10,
used.

The hydroxyl groups X in the above formula (V) may, if desired, be completely or partially replaced by other condensable groups such as alkoxy groups having from 1 to 4 carbon atoms per group.

Within or along the siloxane chain of the organopolysiloxanes of formula (V) given above, which is usually not represented by such formulas, other siloxane units may be present in addition to the diorganosiloxane units R ₂ SiO . Examples of such other, mostly only as impurity present siloxane units are those of the formulas RSiO _3/2 , R ₃ SiO _1/2 and SiO _4/2 , wherein R has the meaning given above.

One kind of organopolysiloxane or more kinds of organopolysiloxanes can be used.

The organopolysiloxanes have a viscosity of preferably 50 to 80,000 mPa.s at 25 ° C, preferably 1000 to 20,000 mPa.s at 25 ° C.

As crosslinkers (8) are preferably used moisture-sensitive silanes of the general formula

R _x SiZ _4-x

and / or their partial hydrolysates, which preferably have 2 to 10 silicon atoms,
where R has the meaning given above,
x is 0 or 1 and
Z is the same or different hydrolyzable radical selected from the group acyloxy, optionally substituted hydrocarbonoxy, amino, oxime, amide, aminoxy and enoxy radical.

wobei R² einen einwertigen Kohlenwasserstoffrest mit 1 bis 12 Kohlenstoffatomen,
R³ einen einwertigen Kohlenwasserstoffrest mit 1 bis 4 Kohlenstoffatomen,
R⁴ Wasserstoff oder gleiche oder verschiedene, einwertige Kohlenwasserstoffreste mit 1 bis 12 Kohlenstoffatomen und
A gleiche oder verschiedene Reste der Formel

         R⁵ ₂C=   oder   R⁶C=

bedeuten, wobei R⁵ gleiche oder verschiedene, einwertige Kohlenwasserstoffreste mit 1 bis 5 Kohlenstoffatomen je Rest und R⁶ einen zweiwertigen Kohlenwasserstoffrest mit 5 bis 6 Kohlenstoffatomen je Rest bedeuten,
verwendet.Preferably, the radicals mentioned for Z are

where R ^{2 is} a monovalent hydrocarbon radical having 1 to 12 carbon atoms,
R ^{3 is} a monovalent hydrocarbon radical having 1 to 4 carbon atoms,
R ^{4 is} hydrogen or identical or different, monovalent hydrocarbon radicals having 1 to 12 carbon atoms and
A is the same or different radicals of the formula

R ⁵ ₂ C = or R ⁶ C =

where R ^{5 is} identical or different, monovalent hydrocarbon radicals having 1 to 5 carbon atoms per radical and R ^{6 is} a bivalent hydrocarbon radical having 5 to 6 carbon atoms per radical,
used.

Examples of acyloxy groups are acetoxy and formyloxy groups and 2-ethylhexanoxy groups.

Examples of hydrocarbonoxy groups are methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy groups.

Examples of substituted hydrocarbonoxy groups are alkoxy-substituted hydrocarbonoxy groups such as methoxyethyleneoxy, ethoxyethyleneoxy and methoxyisopropyleneoxy groups.

Examples of amino groups are n-butylamino, sec-butylamino and cyclohexylamino groups.

Examples of oxime groups are methyl ethyl ketoxime groups, methyl isobutyl ketoxime groups, methyl n-amyl ketoxime groups and dimethylketoxime groups.

Examples of amide groups are n-methylbenzamido groups and n-methylacetamido groups.

An example of an aminoxy group is the hydroxylamine group.

An example of an enoxy group is the isoprenoxy group.

For crosslinking of condensation-crosslinking 2-component compositions, the hardener component is mixed in immediately before use. This hardener component is preferably a tetraalkoxysilane, preferably tetraethyl or tetrapropylsilicate.

The catalyst (9) used are the condensation catalysts known to the person skilled in the art.

Examples of condensation catalysts are butyl titanates and organic tin compounds, such as di-n-butyltin diacetate, di-n-butyltin dilaurate and reaction products of at least two oxygen-bonded to silicon, optionally substituted by an alkoxy group, monovalent hydrocarbon radicals as hydrolyzable groups silane or its oligomer with diorganotin diacylate, in which reaction products all valences of the tin atoms are selected by oxygen atoms of the moiety

≡ SiOSn≡

or are saturated by SnC-bonded, monovalent organic radicals. The preparation of such reaction products is described in detail in US Pat. No. 4,460,761 (issued Jul. 17, 1984, A. Schiller et al., Wacker-Chemie GmbH).

The silicone rubber compositions may contain other ingredients such as fillers (10) such as reinforcing and non-reinforcing fillers and resinous organopolysiloxanes such as MQ resins (11).

Examples of reinforcing fillers (11a), ie fillers with a BET surface area of at least 50 m ² / g, are fumed silica, precipitated silica or silicon-aluminum mixed oxides having a BET surface area of more than 50 m ² / g. The fillers mentioned may be rendered hydrophobic, for example by treatment with organosilanes, silanes or siloxanes or by etherification of hydroxyl groups to alkoxy groups. Preference is given to pyrogenic silicas having a BET surface area of at least 100 m ² / g.

The silicone rubber compositions contain reinforcing fillers (11a) in amounts of preferably 0 to 20% by weight.

Examples of non-reinforcing fillers (11b), ie fillers with a BET surface area of less than 50 m ² / g, are powders of quartz, cristobalite, diatomaceous earth, calcium silicate, zirconium silicate, montmorillonites such as bentonites, zeolites including molecular sieves such as sodium aluminosilicate , Metal oxides such as iron oxide, zinc oxide, titanium dioxide and aluminum oxide or their mixed oxides, metal hydroxides such as aluminum hydroxide, metal carbonates such as calcium carbonate, magnesium carbonate and zinc carbonate, metal sulfates such as barium sulfate, gypsum, silicon nitride, silicon carbide, boron nitride, glass, carbon and plastic powder and glass and plastic hollow spheres.

The silicone rubber compositions contain non-reinforcing fillers in amounts of preferably 0 to 50 wt .-%.

It may be one type of filler, but it may also be a mixture of at least two fillers.

The resinous organopolysiloxanes preferably contain monofunctional (M) and tri- (T) and / or tetrafunctional (Q) units, optionally also difunctional (D) units. Preference is given to the so-called MQ resins (11), which consist of monofunctional and tetrafunctional units.
The monofunctional units may contain as functional groups unsaturated hydrocarbon radicals, such as alkenyl groups or Si-bonded hydrogen.
Preference is given to MQ resins (11) from units of the formulas

R ⁵ R ₂ SiO _1/2 and SiO _4/2

wherein R ^{5 is} a radical R, a hydrogen atom or a radical R ¹ and R and R ^{1 have} the meaning given above, and the Units of the formula R ⁵ R ₂ SiO _{1/2 may be the} same or different.

The ratio of M units of the formula R ⁵ R ₂ SiO _1/2 to Q units of the formula SiO _4/2 is preferably 4: 1 to 1: 2.

Examples of MQ resins (12a) with unsaturated M units are those of units of the formulas
SiO _4/2 and R ¹ R ₂ SiO _1/2 and optionally R ₃ SiO _1/2 ,
ie MQ resins with exclusively unsaturated M units
or MQ resins with saturated and unsaturated M units
wherein R and R ^{1 have} the meaning given above and the ratio of M units R ¹ R ₂ SiO _½ and optionally R ₃ SiO _½ to Q units SiO _{4/2 is} preferably 4: 1 to 1: 2 and the ratio of saturated M units R ₃ SiO _½ to unsaturated M units R ¹ R ₂ SiO _½ preferably 10: 1 to 0: 1.

The MQ resins (12a) are preferably used in amounts of from 0 to 100% by weight, based on the total weight of the organopolysiloxanes (1).

Further examples of M-resins containing Si-bonded hydrogen M-12 (12b) are those of units of the formulas
SiO _4/2 and HR ₂ SiO _1/2 and optionally R ₃ SiO _1/2 ,
ie MQ resins containing only M units with Si-bonded hydrogen,
or MQ resins containing M units with and without Si-bonded hydrogen,
which in addition-crosslinking two component mixtures are preferably contained in component (B),
where R has the meaning given above and the ratio of M units HR ₂ SiO _½ and optionally R ₃ SiO _½ to Q units SiO _{4/2 is} preferably 4: 1 to 1: 2, and the ratio of M units R ₃ SiO _1/2 to M units HR ₂ SiO _{1/2 is} preferably 10: 1 to 0: 1.

The MQ resins (12b) are preferably used in amounts of from 0 to 20% by weight, based on the total weight of the organopolysiloxanes (1).

Organopolysiloxane (2) is contained in the crosslinkable silicone rubber composition in an amount such that the molar ratio of SiH groups in organopolysiloxane (2) to Si-bonded radical R ¹ having aliphatic carbon-carbon multiple bond in organopolysiloxane (1) and MQ resin (12a) (ratio SiH _{siloxane (2)} / C = C _total ) is preferably 0.01 to 10.0, preferably 0.1 to 2.0.

The total amount of all SiH groups in the silicone rubber compositions according to the invention is such that the molar ratio of SiH groups in organopolysiloxane (2), (2 ') and MQ resin (12b) to Si-bonded radical R ¹ with aliphatic carbon-carbon Multiple bond in organopolysiloxane (1) and MQ resin (12a) (SiH _total ratio / C = C _total ) is preferably 1.0 to 10.0, preferably 1.7 to 5.0.

The abovementioned mixtures can be present as one or else as two components. CD and the other constituents (10) and (11) may be contained in component (A) and / or (B) in the case of two components. Preferably, the cyclodextrins or cyclodextrin derivatives are added to the silicone mixture immediately prior to processing.

The invention further relates to methods for producing the bottle corks according to the invention.

A method is characterized in that a bottle cork in a flowable, addition-crosslinking silicone rubber composition, for example prepared from the components CD, (1), (2), (3), (4), (10) and (11) is dipped, and then the excess silicone rubber composition is removed from the bottle cap and the silicone rubber composition is crosslinked.

Another method is characterized in that a highly viscous, addition-curing silicone, e.g. prepared from components (1), (2), (3), (4), (5) and (10) or from components (1), (5), (6) and (10) by press vulcanization of the silicone is formed into a round shaped article and the molded article by means of a silicone adhesive, preferably a known to the expert as acetic acid crosslinking RTV-1 silicone, is adhered to the end face of a bottle cap.

Another method is characterized in that a pasty, addition-crosslinking silicone, e.g. prepared from the components (1), (2), (3), (4), (10) and (11) by means of press vulcanization of the silicone to a round molded article by injection molding and this molded article by means of a silicone adhesive, preferably a person skilled in the art as RTV-1 known as acetic acid-known silicone, is glued to the front of a bottle cork.

Another method is characterized in that a condensation-curing, two-component silicone, e.g. prepared from the components: (1), (7), (8), (9), and (10) is applied to the beverage facing side of a bottle cork and then curing and adhering of the silicone takes place directly on the bottle cork at room temperature.

A further method is characterized in that a condensation-crosslinking silicone, for example composed of a component, prepared from the components (1), (7), (8), (9), and (10) on the side facing the beverage Bottle cork is applied and cured at room temperature. The silicone adheres directly to the bottle cork.

Another method is characterized in that a cork rotating in a closed drum is sprayed with a silicone and thereby wetted on its surface and the silicone is then cured at room temperature.

Another method is characterized in that a highly viscous, addition-curing silicone, e.g. prepared from the components (1), (2), (3), (4), (5) and (10) or from the components (1), (5), (6) and (10) is mixed with cork pieces and molding the mass into a plug-shaped article by press-vulcanization of the silicone.

As bottle corks, commercially available bottle corks are preferably used with a weight of preferably 2.5 to 4.0 g.

The following examples serve to further illustrate the invention.

Examples 1 to 4:

The ingredients given in Tables 1 to 4 are mixed and in each case one component A and B is prepared.

The respectively obtained components A and B are then mixed in a ratio of 1: 1. Table 1: Component A Parts by weight Component B Parts by weight Vi-Polymer 20,000 535 Vi-Polymer 20,000 300 Vi-polymer 1,000 535 Vi-polymer 1,000 300 HDK 30 H 1000 500 Pt catalyst 4.2 H-siloxane 2 inhibitor 0.6 Cavamax W7 110 Cavamax W7 110 Component A Parts by weight Component B Parts by weight Vi-polymer 1,000 500 Vi-polymer 1,000 520 HDK 30 QM-H resin 10 Pt catalyst 2.1 H-siloxane 0.5 inhibitor 0.4 Cavamax W7 220 Cavamax W7 220 Component A Parts by weight Component B Parts by weight Vi-Polymer 7,000 400 Vi-Polymer 7,000 500 QM-Vi resin 100 metal oxides 2 Pt catalyst 6.4 H-siloxane 4 inhibitor 1.0 Cavamax W6 10 Cavamax W6 10 Component A Parts by weight Component B Parts by weight Vi-Polymer 20,000 210 Vi-Polymer 20,000 195 Vi-polymer 1,000 725 Vi-polymer 1,000 610 QM-Vi resin 140 QM-Vi resin 120 metal oxides 20 Crosslinker 525 162 Pt catalyst 2.0 H-siloxane 10 inhibitor 0.3 Cavamax W8 220 Cavamax W8 220

The two components are mixed. The cork stoppers are then immersed in this mixture and vacuum applied. The silicone penetrates into the cavities of the cork. After 5 to 20 minutes, the vacuum is broken and pressure is applied to the container to achieve as complete a wetting as possible. After releasing the overpressure, excess silicone is removed from the surface of the corks and the silicone cured on the cork. The curing takes place at a temperature between 20 and 200 ° C, preferably between 40 and 80 ° C.

Example 5:

The ingredients listed in Table 5 are mixed into one component. Table 5: component Parts by weight V polymer 1200 A 700 HDK 100 Crosslinker 525 50 Pt catalyst 0.1 inhibitor 0.2 Cavamax W8 200

Example 6:

The ingredients listed in Table 6 are mixed and one component A and B are prepared in each case.

The resulting components A and B are then mixed in the ratio 1: 1. Table 6: Component A Parts by weight Component B Parts by weight Vi-Polymer 20,000 400 Vi-Polymer 20,000 400 HDK 50 HDK 50 Pt catalyst 0.4 Crosslinker 525 1.5 inhibitor 0.4 Cavasol W8 40 Cavasol W8 40

Example 7:

The ingredients listed in Table 7 are mixed into one component. Table 7: component Parts by weight V polymer 1200 A 700 HDK 150 metal oxides 150 peroxide 10 Cavamax W8 100

The mixture of example 5 or 7 or the combined mixture of the two components from example 6 is processed into shaped parts in a typical injection molding or compression molding process for these substances. These moldings are connected to the Korkstopfen in an appropriate manner. This can be done by gluing with a silicone adhesive or by mechanical fixing or a combination of both.

Also, the mixture of Example 5 or 7 or the combined mixture of the two components of Example 6 can be mixed with pieces of cork and this compound by the vulcanization of the silicone part in a typical for these substances injection molding or compression molding process to stopper.

Example 8:

The ingredients shown in Table 8 are mixed and one component A and B are prepared respectively.

The resulting components A and B are then mixed in a ratio of 10: 1. The ingredients listed in Table 8 are mixed into one component. Table 8: Component A Parts by weight Component B Parts by weight OH polymer 20,000 400 Vi-Polymer 20,000 400 HDK 20 Sn catalyst 2.4 metal oxides 100 Alkoxy crosslinker 20 water 0.4 Cavamax W8 100 Cavamax W8 100

Example 9:

The ingredients listed in Table 9 are mixed into one component. Table 9: component Parts by weight OH polymer 20,000 500 HDK 50 metal oxides 50 ES 15 10 Ti (BuO) ₄ 0.4 Cavasol W6 80

The combined mixture of the two components of Example 8 or the mixture of Example 9 is added to the wine later brushed front side of the cork so that the cork can have little or no direct contact with the wine. To provide a sufficient amount of silicone to receive the TCA, a recess is preferably placed in the face of the cork prior to application of the silicone. The vulcanizate preferably forms a mechanical anchoring in the plug.
Also, silicones of the above mixtures of Examples 8 and 9 can be applied one after the other and thus combined with one another.

• Vi-Polymer 1.000:
  Organopolysiloxan der Formel: ViMe₂SiO(Me₂SiO)_n ¹SiMe₂Vi n¹=200 mit einer Viskosität von 1 000 mPa·s bei 25°C
• Vi-Polymer 7.000:
  Organopolysiloxan der Formel: ViMe₂SiO (Me₂SiO)_n ²SiMe₂Vi n²=450 mit einer Viskosität von 7 000 mPa·s bei 25°C
• Vi-Polymer 20.000:
  Organopolysiloxan der Formel: ViMe₂SiO(Me₂SiO)_n ³SiMe₂Vi n³=600 mit einer Viskosität von 20 000 mPa·s bei 25°C
• H-Siloxan:
  Organopolysiloxan der Formel: Me₃SiO(MeHSiO)_n ⁴SiMe₃ n⁴=50 mit einer Viskosität von 1 000 mPa·s bei 25°C und
  1,6 Gew.-% Si-gebundenem Wasserstoff.
• H 1000:
  Organopolysiloxan der Formel: HMe₂SiO(Me₂SiO)_n ⁵SiMe₂H n=200 mit einer Viskosität von 1 000 mPa·s bei 25°C und
  0,013 Gew.-% Si-gebundenem Wasserstoff.
• Vernetzer 525:
  Organopolysiloxan der Formel:
  Me₃SiO (MeHSiO)_n ⁶(Me₂SiO)_n7SiMe₃ n⁶+n⁷=200, n⁶:n⁷=1:2
  mit einer Viskosität von 400 mPa·s bei 25°C und
  0,5 Gew.-% Si-gebundenem Wasserstoff.
• V Polymer 1200 A:
  Organopolysiloxan der Formel: ViMe₂SiO(Me₂SiO)_n ⁸(ViMeSiO)_mSiMe₂Vi n⁸+m=5000, n⁸:m=1000:1
  mit einer Viskosität von 10 000 000 mPa·s bei 25°C
• OH-Polymer 20.000:
  Organopolysiloxan der Formel: (OH)Me₂SiO(Me₂SiO)_n ⁹SiMe₂(OH) n⁹=600
  mit einer Viskosität von 20 000 mPa·s bei 25°C
• QM-Vi Harz:
  Harz aus Einheiten der Formel
  SiO_4/2 (Q), Me₃SiO_1/2 (M) und ViMe₂SiO_1/2 (M_v),
  mit einem Verhältnis von Q : M : M_v = 1 : 0,1 : 0,6
• QM-H Harz:
  Harz aus Einheiten der Formel
  SiO_4/2 (Q), HMe₂SiO_1/2 (M_H),
  mit einem Verhältnis von Q : M_H = 1 : 2
• Peroxid:
  Dicumylperoxid
• Alkoxy Vernetzer:
  1,2-Bis-(Triethoxysilyl)-ethan
• ES 15:
  Methyltriacetoxysilan
• Sn Katalysator:
  Dibuthylzinndiacetat
• Cavamax W6:
  Cyclohexaamylose (α-CD, käuflich erhältlich unter dem Handelsnamen Cavamax® W6 bei der Firma Wacker-Chemie GmbH).
• Cavamax W7:
  Cycloheptaamylose (β-CD käuflich erhältlich unter dem Handelsnamen Cavamax® W7 bei der Firma Wacker-Chemie GmbH).
• Cavamax W8:
  Cyclooctaamylose (γ-CD, käuflich erhältlich unter dem Handelsnamen Cavamax® W8 bei der Firma Wacker-Chemie GmbH).
• Cavasol W6:
  2-(Hydroxypropyl)-cyclohexaamylose (käuflich erhältlich unter dem Handelsnamen Cavasol® W6 bei der Firma Wacker-Chemie GmbH).
• Cavasol W8:
  2-(Hydroxypropyl)-cyclooctaamylose (käuflich erhältlich unter dem Handelsnamen Cavasol® W8 bei der Firma Wacker-Chemie GmbH).
• HDK:
  Pyrogen hergestellte Kieselsäure mit einer BET-Oberfläche von 125 m²/g (käuflich erhältlich unter dem Handelsnamen WACKER HDK® S13 bei der Firma Wacker-Chemie GmbH).
• Metalloxide:
  Mischung aus verschiedenen Metalloxiden enthaltend Titandioxid und Eisenoxiden käuflich erhältlich unter den Handelsnamen Kronos® 2056 bei der Firma Kronos Titan,
  SICOTAN® Gelb K 1011 bei der Firma BASF AG und
  BAYFERROX® 610 bei der Firma Bayer AG.
  Das Mischungsverhältnis dieser drei Stoffe beträgt 10:10:1. Das Mischungsverhältnis wurde so gewählt, um einen dem Naturkorken möglichst ähnlichen Farbton zu erreichen.
• Inhibitor: Ethinylcyclohexanol

The constituents given in Table 1 to 9 are the following compounds, where Me = methyl radical and Vi = vinyl radical:

• Vi-Polymer 1.000:
  Organopolysiloxane of the formula: ViMe ₂ SiO (Me ₂ SiO) _n ¹ SiMe ₂ Vi n ¹ = 200 with a viscosity of 1000 mPa · s at 25 ° C.
• Vi-Polymer 7,000:
  Organopolysiloxane of the formula: ViMe ₂ SiO (Me ₂ SiO) _n ² SiMe ₂ Vi n ² = 450 with a viscosity of 7 000 mPa · s at 25 ° C.
• Vi-Polymer 20,000:
  Organopolysiloxane of the formula: ViMe ₂ SiO (Me ₂ SiO) _n ³ SiMe ₂ Vi n ³ = 600 with a viscosity of 20,000 mPa · s at 25 ° C.
• H-siloxane:
  Organopolysiloxane of the formula: Me ₃ SiO (MeHSiO) _n ⁴ SiMe ₃ n ⁴ = 50 with a viscosity of 1000 mPa · s at 25 ° C and
  1.6% by weight Si-bonded hydrogen.
• H 1000:
  Organopolysiloxane of the formula: HMe ₂ SiO (Me ₂ SiO) _n ⁵ SiMe ₂ H n = 200 with a viscosity of 1000 mPa · s at 25 ° C and
  0.013 wt.% Si-bonded hydrogen.
• Crosslinker 525:
  Organopolysiloxane of the formula:
  Me ₃ SiO (MeHSiO) _n ⁶ (Me ₂ SiO) _n 7SiMe ₃ n ⁶ + n ⁷ = 200, n ⁶ : n ⁷ = 1: 2
  with a viscosity of 400 mPa · s at 25 ° C and
  0.5% by weight of Si-bonded hydrogen.
• V Polymer 1200 A:
  Organopolysiloxane of the formula: ViMe ₂ SiO (Me ₂ SiO) _n ⁸ (ViMeSiO) _m SiMe ₂ Vi n ⁸ + m = 5000, n ⁸ : m = 1000: 1
  with a viscosity of 10 000 000 mPa · s at 25 ° C
• OH polymer 20,000:
  Organopolysiloxane of the formula: (OH) Me ₂ SiO (Me ₂ SiO) _n ⁹ SiMe ₂ (OH) n ⁹ = 600
  with a viscosity of 20,000 mPa · s at 25 ° C
• QM-Vi resin:
  Resin of units of the formula
  SiO _4/2 (Q), Me ₃ SiO _1/2 (M) and ViMe ₂ SiO _1/2 (M _v ),
  with a ratio of Q: M: M _v = 1: 0.1: 0.6
• QM-H resin:
  Resin of units of the formula
  SiO _4/2 (Q), HMe ₂ SiO _1/2 (M _H ),
  with a ratio of Q: M _H = 1: 2
• Peroxide:
  dicumylperoxide
• Alkoxy crosslinker:
  1,2-bis- (triethoxysilyl) ethane
• ES 15:
  methyltriacetoxysilane
• Sn catalyst:
  Dibuthylzinndiacetat
• Cavamax W6:
  Cyclohexaamylose (α-CD, commercially available under the trade name Cavamax® W6 from Wacker-Chemie GmbH).
• Cavamax W7:
  Cycloheptaamylose (β-CD commercially available under the trade name Cavamax® W7 from Wacker-Chemie GmbH).
• Cavamax W8:
  Cyclooctaamylose (γ-CD, commercially available under the trade name Cavamax® W8 from Wacker-Chemie GmbH).
• Cavasol W6:
  2- (hydroxypropyl) -cyclohexaamylose (commercially available under the trade name Cavasol® W6 from Wacker-Chemie GmbH).
• Cavasol W8:
  2- (hydroxypropyl) cyclooctaamylose (commercially available under the trade name Cavasol® W8 from Wacker-Chemie GmbH).
• HDK:
  Pyrogenic silica with a BET surface area of 125 m ² / g (commercially available under the trade name WACKER HDK® S13 from Wacker-Chemie GmbH).
• Metal oxides:
  Mixture of various metal oxides containing titanium dioxide and iron oxides commercially available under the trade names Kronos® 2056 from Kronos Titan,
  SICOTAN® Yellow K 1011 at BASF AG and
  BAYFERROX® 610 at Bayer AG.
  The mixing ratio of these three substances is 10: 10: 1. The mixing ratio was chosen so as to achieve a natural color cork as closely as possible hue.
• Inhibitor: ethynylcyclohexanol

Pt catalyst:

Solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex in dimethylpolysiloxane having a platinum content of this solution of 1% by weight

Example 10:

Comparison of the effectiveness of trichloroanisole absorption of an elastomer and a CD containing elastomer.

The ratio silicone: wine is approximately 1: 1000 in a 0.71 bottle of wine with a 0.5 to 1.0 g silicone coated cork. Therefore, 0.1 g of silicone vulcanizates according to Ex. 1 to 4 in 100 ml of 12% ethanol, which had an initial concentration of TCA of 0.2 ppm, and the proportion of TCA remaining in the ethanol solution were determined at different times.

Table 10 shows by way of example the results for one of the silicone vulcanizates in which, in addition, the CD content was varied as indicated. Table 10: No. Cyclodextrin in the vulcanizate in% Percentage of TCA remaining in solution 1d 3d 7d 14d 21d 28d 1 23% 50% 40% 20% 15% 5% 5% 2 10% 75% 30% 20% 20% 15% 15% 3 2% 70% 35% 30% 35% 35% 30% 4 0% 75% 70% 60% 60% 60% 60%

A CD-free silicone vulcanizate (prior art) absorbs about 40% of the original TCA dissolved in the ethanol within 1 week. This 40:60 distribution: (TCA in Silicon) :( TCA in 12% ethanol solution) is largely independent of the type of silicone chosen. Only by adding a cyclodextrin according to the invention is a significant shift in the equilibrium towards the silicone vulcanizate achieved.

Claims (15)

Cork-containing bottle cork having a surface provided with a coating of an elastomer, characterized in that the elastomer contains uncomplexed α-, β- or γ-cyclodextrin or uncomplexed α-, β- or γ-cyclodextrin derivative. Bottle cork according to claim 1, characterized in that the elastomer contains 0.01 to 40 wt .-% CD, preferably 10 to 25 wt .-%. Bottle cork according to claim 1 or 2, characterized in that the elastomer contains uncomplexed α-, β- or γ-cyclodextrin. Bottle cork according to claim 3, characterized in that the elastomer contains uncomplexed γ-cyclodextrin. Bottle cork according to one of claims 1 to 4, characterized in that the elastomer is obtainable from a crosslinkable silicone rubber composition containing (1) organopolysiloxanes (1) having radicals having aliphatic carbon-carbon multiple bonds, (2) organopolysiloxanes having Si-bonded hydrogen atoms, (3) the addition of Si-bonded hydrogen to aliphatic multiple bonds promoting catalysts and optionally (4) the addition of Si-bonded hydrogen to aliphatic multiple bonds delaying agents, so-called inhibitors,
or (5) Organopolysiloxanes (1) having radicals with aliphatic carbon-carbon multiple bonds, and (6) the radical crosslinking of aliphatic multiple and single bonds promoting peroxides,
or (7) organopolysiloxanes having radicals with hydroxyl groups, (8) as crosslinkers siloxanes with Si-bonded, hydrolyzable groups and (9) the hydrolysis of these groups to form Si-O-Si bridge promoting catalysts. Bottle cork according to claim 5, characterized in that the elastomer is obtainable from a crosslinkable silicone rubber composition containing as organopolysiloxanes (1) or (5) those of the general formula

R ¹ _g R _3-g SiO (SiR ₂ O) _n (SiRR ¹ O) _m SiR _3-g R ¹ _g (II)

wherein R is the same or different, a monovalent, optionally halogenated hydrocarbon radical having 1 to 18 carbon atom (s) per radical, and
R ^{1 is the} same or different, is a monovalent hydrocarbon radical having a terminal, aliphatic carbon-carbon multiple bond having 2 to 8 carbon atoms per radical,
g is 0, 1, 2 or 3,
m is 0 or an integer from 1 to 5000 and
n is an integer from 70 to 10,000,
with the proviso that the organopolysiloxanes of the formula (II) contain at least 2 radicals R ¹ per molecule. Bottle cork according to claim 5 or 6, characterized in that the elastomer is obtainable from a crosslinkable silicone rubber composition containing as organopolysiloxanes (2) those of the general formula

H _h R _3-h SiO (SiR ₂ O) _o (SiR ₂ -x H _x O) _p SiR _{3 -h} H _h (IV)

where R has the meaning given in claim 6,
h 0, 1 or 2,
o is 0 or an integer from 1 to 1,000,
p is an integer from 1 to 1,000 and
x is 1 or 2. Bottle cork according to claim 5 or 6, characterized in that the elastomer is obtainable from a crosslinkable silicone rubber composition containing as organopolysiloxanes (7) those of the general formula

XR ₂ SiO (R ₂ SiO) _n SiR ₂ X (V)

where R is identical or different, monovalent, optionally substituted hydrocarbon radicals having 1 to 18 carbon atoms per radical,
X is a hydroxyl group and
n is an integer of at least 10. Bottle cork according to claim 5, 6 or 8, characterized in that the elastomer is obtainable from a crosslinkable silicone rubber composition containing as crosslinking agent (8) moisture-sensitive silanes of the general formula

R _x SiZ _4-x

and / or their partial hydrolysates, which preferably have 2 to 10 silicon atoms,
where R has the meaning given above,
x is 0 or 1 and
Z is the same or different hydrolyzable radical selected from the group acyloxy, optionally substituted hydrocarbonoxy, amino, oxime, amide, aminoxy and enoxy radical. Method for producing a bottle cork according to one of claims 1 to 9, characterized in that a bottle cork is dipped in a flowable, addition-crosslinking silicone rubber composition, and then the excess silicone rubber composition is removed from the bottle cap and the silicone rubber composition is crosslinked. A process for producing a bottle cork according to any one of claims 1 to 9, characterized in that a highly viscous, addition-crosslinking silicone, by means of press vulcanization of the silicone is formed into a round shaped article and the molded article is adhered by means of an adhesive to the front side of a bottle cork. A process for producing a bottle cork according to any one of claims 1 to 9, characterized in that a pasty, addition-curing silicone is molded by press vulcanization of the silicone to a round molded article by injection molding and this molded article is glued by means of an adhesive to the front side of a bottle cork A process for producing a bottle cork according to any one of claims 1 to 9, characterized in that a condensation-crosslinking, composed of two components silicone, is applied to the beverage facing side of a bottle cork, and then curing and adherence of the silicone directly to the bottle cork at room temperature he follows. A process for producing a bottle cork according to any one of claims 1 to 9, characterized in that a condensation-crosslinking, composed of a component silicone is applied to the beverage facing side of the bottle cork and then curing and adhering of the silicone takes place directly on the bottle cork at room temperature. Method for producing a bottle cork according to one of claims 1 to 9, characterized in that a cork rotating in a closed drum is sprayed with a silicone and thereby wetted on its surface, and the silicone is then cured at room temperature.