DE10227590A1 - Crosslinkable organopolysiloxane plasticizers condensation crosslink to form bleeding-free (sic) elastomers useful in coating joints, facades, windows, and in the sanitary and technical industries - Google Patents

Abstract

Crosslinkable organopolysiloxane compositions obtained by condensation, containing diorganopolysiloxanes as plasticizers, are new. Crosslinkable organopolysiloxanes (M) obtained by condensation, contain diorganopolysiloxanes (W) as plasticizers of formula (I). R3Si-(O-SiR1>2)n-SiR3 (I) R and R1>monovalent 1-8C hydrocarbon optionally substituted with F, Cl, Br, 1-4C alkoxyalkyl or cyano groups; and n : a value such that the viscosity of the organopolysiloxanes (W) is 5-25 mm2>/s at 25 [deg]C.

Description

The invention relates to bleeding-free by condensation Elastomer crosslinkable organopolysiloxane masses which Plasticizers contain low molecular weight diorganopolysiloxane.

Can be crosslinked to form elastomers Organopolysiloxane compositions have long been used to seal Joints in facade and window construction, in sanitary and in technical-industrial area used. The usage such masses are then restricted if the Organopolysiloxane elastomers in contact with absorbent Materials stand.

Because the organopolysiloxane elastomers generally contain ingredients included that are not in the high molecular weight elastomer network are involved, they can be in contact with absorbent Emigrate materials. This emigration leads to Soiling of the contact materials in the edge area, recognizable through the formation of dark margins.

Examples of absorbent materials are in particular Natural stones such as marble, granite, quartzite and sandstone, however also wood materials that are untreated or with open cells Coating materials are pretreated. Eligible hike Components in organopolysiloxane elastomers are especially Plasticizers such as triorganosiloxy groups as terminal Unit-containing organopolysiloxanes or plasticizers Hydrocarbon base, as described in DE-AS-23 64 856, DE-AS-28 02 170, DE-AS-29 08 036, DE-OS-33 23 911, DE-OS-33 29 877,  DE-PS-33 42 026, EP-A-218875, EP-A-801101, DE-A-196 20 100, EP-A-842974 and EP-A-885921.

The hydrocarbon-based plasticizers are larger Volatility compared to the plasticizers Organopolysiloxane based on, d. H. they steam out of the Elastomers. In addition, they are often not very UV stable, which leads to can cause yellowing of the vulcanizates.

To seal organopolysiloxane elastomers between joints Absorbent building materials must be able to use them without Plasticizers are made. This results in Mixtures which are viscous in the unvulcanized state and can be processed poorly, and in vulcanized Condition have a hard elastic property profile, d. H. the Vulcanizates have a high tension value when stretched. This is in many applications as a joint sealant undesirable, because the expansion on the joint flanks occurring high forces a premature replacement of the Elastomers, d. H. Loss of adhesion can cause. Moreover can building materials with low inherent strength such as plaster or Tear out aerated concrete in the joint flank area and thus destroy it become.

There has therefore been a long-standing task of bleeding-free Low tension organopolysiloxane elastomers To produce stretch.

If it is organopolysiloxane elastomers, their Tendency to self-pollution, d. H. to absorb dirt from the environment of the elastomer on the surface of the Elastomers, should be reduced, this task solved that various additives are added to the elastomers.  

Additives of this type are organopolysiloxane resins, drying agents Oils, d. H. Reaction products from unsaturated fatty acids and Alcohols such as B. wood oil, fluorocarbons and fluorinated organopolysiloxanes or UV-curing oligomers with Acrylic groups such as polyester acrylates, epoxy acrylates or Urethane acrylates. Additives of this type are, for example described in DE-PS-20 59 109, DE-AS-20 59 112, US-A-4395443, EP-A-92044, US-A-4460740, DE-OS-34 23 770, EP-A-131446, EP-A-135293, US-A-4495340, US-A-4496696, US-A-4500584, US-A-4695603, EP-A-562878, US-A-5254657, EP-A-587295, US-A-5326816, EP-A-626426, EP-A-799860, US-A-5840805 and US-A-6265516.

In addition, special crosslinkable organopolysiloxanes with functional groups such as carboxyl, sulfonate, polyglycol, Amino, epoxy or imidazolyl used. This last mentioned special organopolysiloxanes or copolymers with organic residues, as described, for example, in EP-A-81119, EP-A-210442 and US-A-5093389 also used for the production of plasticizer-free elastomers that not only little dirt from the Ambient atmosphere accumulate on the surface, but also are bleeding-free. Due to the absence of plasticizers however, they have the disadvantage that they are hard elastic. In addition, their production is complex and expensive.

WO 00/47680 describes hydroxy-terminated isocyanate-free Urethane prepolymers described by the reaction of polyol be made with an isocyanate. These can be as Plasticizers in cross-linking to elastomers Organopolysiloxane compositions are used. The elastomers are ausblutungsfrei. The use of urethane prepolymers in However, organopolysiloxane compositions reduce them Weatherability. They also tend to yellowing.  

The invention relates to organopolysiloxane compositions (M) which can be crosslinked by condensation and which, as plasticizers, contain diorganopolysiloxane (W) of the general formula (I)

R ₃ Si- (O-SiR ¹ ₂ ) _n -SiR ₃ (I)

included in the
R and R ^{1 are} monovalent C ₁ -C ₈ hydrocarbon radicals which are optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ alkoxyalkyl or cyano groups and
n means values which correspond to a viscosity of the organopolysiloxane (W) of 5 to 25 mm ² / s at 25 ° C.

The organopolysiloxane compositions (M) which can be crosslinked by condensation cross-link to bleeding-free elastomers with low Tension value when stretched as a plasticizer Diorganopolysiloxane (W) included.

The molecular weight is preferably Diorganopolysiloxanes (W) maximum 1100. Preferably n means Values from 6 to 15, especially 8 to 12.

The viscosity of the diorganopolysiloxanes (W) is preferably 5 to 15 mm ² / s, particularly preferably 8 to 12 mm ² / s.

Diorganopolysiloxanes (W) with a viscosity below 5 mm ² / s are too volatile and disadvantageously increase the shrinkage of the organopolysiloxane elastomers produced therefrom. Diorganopolysiloxanes (W) with a viscosity of over 25 mm ² / s migrate from the organopolysiloxane elastomers produced with them into porous contact materials and contaminate them with the formation of unsightly, dark-colored edge strips.

Examples of hydrocarbon radicals R and R ¹ are linear and cyclic saturated and unsaturated alkyl radicals such as the methyl radical, aryl radicals such as the phenyl radical, alkaryl radicals such as tolyl radicals and aralkyl radicals such as the benzyl radical.

Preferred radicals R and R ¹ are unsubstituted hydrocarbon radicals having 1 to 6 carbon atoms, the methyl radical being particularly preferred. R and R ¹ are preferably the same radicals.

Organopolysiloxane masses (M) can be in one or more Components are available. Two- and one-component are preferred Masses, especially crosslinkable at room temperature Organopolysiloxane compositions (RTV compositions). Preferably, the crosslinkable organopolysiloxane compositions (M) with atmospheric moisture networkable (RTV-1 masses).

Preferred are RTV-1 organopolysiloxane compositions (M), which can be obtained by mixing diorganopolysiloxane (W), α, ω-dihydroxypolydiorganosiloxane (A), crosslinker (B) and Filler (C).

Linear α, ω-dihydroxypolydiorganosiloxanes of the general formula (II) are preferably used as α, ω-dihydroxypolydiorganosiloxanes (A)

HO- [R ² ₂ SiO] _m -H (II)

used where
R ² denotes monovalent C ₁ -C ₈ hydrocarbon radicals which are optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ alkoxyalkyl or cyano groups and
m means values which correspond to a viscosity of the HO-terminated organopolysiloxane (A) of 0.05 to 1000 Pa.s at 25 ° C.

Examples of hydrocarbon radicals R ² are linear and cyclic saturated and unsaturated alkyl radicals such as the methyl radical, aryl radicals such as the phenyl radical, alkaryl radicals such as tolyl radicals and aralkyl radicals such as the benzyl radical.

Preferred radicals R ² are unsubstituted hydrocarbon radicals having 1 to 6 carbon atoms, the methyl radical being particularly preferred.

R, R ¹ and R ² are preferably the same.

The organopolysiloxanes (A) preferably have one Viscosity from 100 to 700,000 mPa.s, in particular from 20,000 to 350,000 mPa.s, each measured at 23 ° C.

Preferably at least 40, especially at least 50% by weight and preferably at most 90, in particular at most 80% by weight of organopolysiloxane (A), based on the total Organopolysiloxane mass (M) used.

Crosslinkers (B) used are preferably silanes which have groups which can be condensed with the hydroxyl groups of the α, ω-dihydroxypolydiorganosiloxane, and oligomeric condensation products of these silanes. Silanes and / or their condensation products of the general formula (III) are used in particular as crosslinking agents (B)

R ³ _n SiX _(4-n) (III),

in the
R ³ are monovalent, optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ -alkoxyalkyl, amino-C ₁ -C ₆ alkyl, amino-C ₁ -C ₆ - alkyleneamino or cyano-substituted C ₁ -C ₁₀ - hydrocarbon residues,
X is hydrogen, fluorine, chlorine or bromine atoms, C ₁ -C ₄ alkoxy, C ₁ -C ₄ acyloxy, amino, C ₁ -C ₆ alkylamino, C ₁ -C ₄ dialkylamino , -C ₁ -C ₆ alkylamido, - (NC ₁ -C ₄ alkyl) -C ₁ -C ₆ - alkylamido or Si-ON = bonded C ₃ -C ₆ ketoximo groups and
n means the values 0, 1 or 2.

Preferably at least 0.5, especially at least 2% by weight and preferably at most 15, in particular at most 10 wt .-% crosslinker (B), based on the total Organopolysiloxane mass (M) used.

Examples of fillers (C) are non-reinforcing fillers, i.e. fillers with a BET surface area of up to 50 m ² / g, such as chalk covered with carboxylic acid, quartz, diatomaceous earth, calcium silicate, zirconium silicate, zeolites, metal oxides such as aluminum, titanium, iron - or zinc oxides or their mixed oxides, barium sulfate, calcium carbonate, gypsum, silicon nitride, silicon carbide, boron nitride, glass and plastic powders, such as polyacrylonitrile powder; reinforcing fillers, ie fillers with a BET surface area of more than 50 m ² / g, such as silica, for example pyrogenically prepared silica or precipitated silica, carbon black such as furnace black and acetylene black and silicon-aluminum mixed oxides having a large BET surface area; fibrous fillers such as asbestos and plastic fibers.

The fillers (C) mentioned can be hydrophobized, for example by treatment with organosilanes or -siloxanes or with stearic acid or by etherification of Hydroxyl groups to alkoxy groups. It can be a kind of Filler, it can also be a mixture of at least two Fillers are used.

The organopolysiloxane composition (M) preferably contains at least 2, in particular at least 5% by weight and preferably at most 50, in particular at most 15% by weight of filler (C).

The organopolysiloxane composition (M) preferably contains one or several catalysts (D). It is preferably the Catalysts (D) around tin catalysts. The tin catalysts are preferably organic tin compounds, such as di-n- butyltin diacetate, di-n-butyltin dilaurate and Reaction products of at least two per molecule Oxygen bound to silicon, optionally by a Monovalent hydrocarbon radicals substituted by alkoxy groups as hydrolyzable groups containing silane or its Oligomer with diorganotin diacylate, being in these Reaction products through all valences of the tin atoms Oxygen atoms of the grouping ∼SiOSn∼ or ∼COSn∼ or through SnC-bound, monovalent organic residues are saturated.

The organopolysiloxane composition (M) preferably contains at least 0.01, in particular at least 0.1% by weight and preferably at most 3, in particular at most 1% by weight of tin catalyst.  

The organopolysiloxane composition (M) preferably contains one or several adhesion promoters (E). Preferred adhesion promoters (E) are amino functional organosilicon compounds.

Examples of amino-functional organosilicon compounds (E) are amino-functional silanes and amino-functional organosiloxanes. Examples of amino functional residues of Organosilicon compounds (E) are aminomethyl, 1-aminoethyl, 3-aminopropyl-, N- (2-aminoethyl) -3-aminopropyl-, Aminoethylaminoethylaminopropyl and Cyclohexylaminopropylrest.

The addition of other ingredients, such as Catalysts, pigments and fungicides are possible.

The term polysiloxanes is intended in the context of the present Invention include dimeric, oligomeric and polymeric siloxanes.

Examples

In the following examples, all information is from Parts and percentages by weight unless otherwise is specified.

Unless otherwise stated, the following are Examples at a pressure of the surrounding atmosphere, i.e. at about 1000 hPa, and room temperature, i.e. at 20 ° C, or at a temperature that changes when the reactants are combined at room temperature without additional heating and cooling hires, performed.

Stating that a paste is stable means that it is when tested according to ISO (International Standard) 7390 from one Rail with profile U 20 (clear width: 20 mm, depth: 10 mm) exits no more than 2 mm.  

The mechanical values, i.e. H. Stress value at elongation, Tensile strength and elongation at break, according to ISO 8339 Contact material made of aluminum and pre-storage A, d. H. storage of the test specimens for 28 days at 23 ° C and 50% relative humidity.

The Shore A hardness of the elastomers is also reduced four weeks pre-storage of the test specimens at 23 ° C and 50% relative humidity determined according to ISO 868.

The contamination of porous substrates is measured according to ASTM (American Society for Testing and Materials) C 1248. Altaquarzit without primer is used as substrate. After 21 days of vulcanization at 23 ° C and 50% relative humidity, the test specimens are compressed by 25%, then for a total of 28 days

• - 23 ° C and 50% relative humidity
• - 70 ° C in the heating cabinet and
• - in the UV test chamber as described in ASTM C 1248

stored.

The determination of the Plasticizer output hike.

example 1 a) Preparation of the agent to improve liability

In one with a reflux condenser, thermometer and stirrer equipped three-necked flask are 200 parts in one terminal units each have a Si-bonded hydroxyl group having dimethylpolysiloxane with a viscosity of  80 mPa.s at 23 ° C and 83 parts of N- (2-aminoethyl) -3- aminopropyltrimethoxysilane with 1.7 parts 5 percent methanolic potassium hydroxide solution mixed. The mixture thus obtained is heated to 140 ° C. for 3 hours with stirring. Then the The contents of the flask cooled to 50 ° C and with a part 10 percent aqueous hydrochloric acid mixed, the reflux condenser replaced by a descending cooler with still and the pressure in this device to 100 hPa (abs.) decreased. Finally, the three-necked flask becomes distilled to 180 ° C at 50 hPa (abs.) Boiling fractions.

The residue is a Si-bonded methoxy group Organopolysiloxane from dimethylsiloxane and N- (2-aminoethyl) -3- aminopropylsiloxaneinheiten.

b) Manufacture of the consolidation catalyst

A mixture of 4 parts of tetra-n-propoxysilane and 1 part of di-n-butyltin diacetate is heated to 120 ° C. for 6 hours with stirring. At the same time, the resulting n-propyl acetate is distilled off continuously. Thereafter, the valence vibration of the carbonyl group of di-n-butyltin diacetate, which is around 1600 cm ^-1 , has disappeared according to the infrared spectrum.

c) In a planetary mixer kneader with vacuum equipment, 45 parts of a dimethylpolysiloxane with a Si-bonded hydroxyl group in the terminal units, each with a viscosity of 75000 mPa.s at 23 ° C and 25 parts of a dimethylpolysiloxane with a viscosity of 10, end-blocked with trimethylsiloxy groups, with exclusion of water mm ² / s at 23 ° C and 1.0 part of polyethylene polypropylene glycol with a molecular weight of approx. 3400 and an ethylene oxide content of approx. 45%.

First, 5.0 parts of a mixture are made into this mixture 88% methyltris (2-butanone) oximosilane and 12% tetrakis (butanone-2) -oximosilane and then 1.0 part of the under a) organopolysiloxane described in more detail with over carbon Silicon-bonded amino groups stirred in and in vacuo 5 Minutes homogenized.

The mixture obtained in this way is mixed with 20 parts of calcium carbonate, the surface of which is coated with stearic acid (“coated chalk”) and has a BET specific surface area of approximately 1 m ² / g, 6.5 parts of pyrogenically produced hydrophilic silicon dioxide in the gas phase a BET surface area of 150 m ² / g and 0.1 part of the reaction product, the preparation of which is described under b).

d) The procedure described under c) is repeated with the modification that instead of 25 parts of a dimethylpolysiloxane endblocked with trimethylsiloxy groups with a viscosity of 10 mm ² / s at 23 ° C, one with a viscosity of 100 mm ² / s at 23 ° C is used.

e) The procedure described under c) is repeated with the modification that instead of 45 parts of a dimethylpolysiloxane having a Si-bonded hydroxyl group in the terminal units and having a viscosity of 75000 mPa.s at 23 ° C., 70 parts are used and on the addition of 25 parts of a dimethylpolysiloxane endblocked with trimethylsiloxy groups and having a viscosity of 10 mm ² / s at 23 ° C. is dispensed with.

The obtained according to Examples 1c) to 1d) by Evacuation of entrapped air, to the exclusion of water-storable, when water is entered at room temperature  RTV molding compounds crosslinking to form elastomers are homogeneous and stable. They are filled into tubes. While the mixtures of Examples 1c) and 1d) are supple and soft can be squeezed out easily, is the mixture of Example 1e) viscous and difficult to process.

The results of testing plasticizer emigration after ASTM C 1248 and the mechanical values according to ISO 8339 are in Table 1 reproduced.

Table 1

Example 2

In a planetary mixer with vacuum equipment, 60 parts of a dimethylpolysiloxane with a Si-bonded hydroxyl group in the terminal units and a viscosity of 75000 mPa.s at 23 ° C with 24.4 parts of a dimethylpolysiloxane with a viscosity of 10 which is endblocked with trimethylsiloxy groups are excluded with water mm ² / s at 23 ° C and 0.8 parts of a mixture of alkoxylated phosphoric acid esters of the formulas

(HO) PO [(OCH ₂ CH ₂ ) _3-4 -O- (CH ₂ ) _11-14 -CH ₃ ] ₂

and

(HO) ₂ PO [(OCH ₂ CH ₂ ) _3-4 -O- (CH ₂ ) _11-14 -CH ₃ ]

mixed.

Immediately afterwards add a mixture of 2.0 parts vinyl trimethoxysilane and 1.5 parts of methyl trimethoxysilane to and homogenized in vacuum for 5 minutes.

Then you set while maintaining the masses for RTV-1 usual mixing technology in the order given.

• - 1.8 parts of amino functional siloxane: equilibration product from 3-aminopropyl-triethoxysilane and a condensate / hydrolyzate from methyl-trimethoxysilane with an amine number of 2.2,
• 0.2 parts of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane,
• - 9.0 parts of pyrogenic, hydrophilic silica with a BET surface area of 150 m ² / g and
• - 0.30 parts of the one described in Example 1 under b) Reaction product.

a) The procedure described under a) is repeated with the modification that instead of 24.4 parts of a dimethylpolysiloxane endblocked with trimethylsiloxy groups with a viscosity of 10 mm ² / s at 23 ° C., one with a viscosity of 100 mm ² / s 23 ° C is used.

b) The procedure described under a) is repeated with the modification that instead of 60 parts of a dimethylpolysiloxane each having an Si-bonded hydroxyl group in the terminal units and having a viscosity of 75000 mPa.s at 23 ° C., 84.4 parts are used and the addition of 24.4 parts of a dimethylpolysiloxane endblocked with trimethylsiloxy groups and having a viscosity of 10 mm ² / s at 23 ° C. is dispensed with.

The obtained in Examples 2a) to 2c) by Evacuation of entrapped air, to the exclusion of water-storable, when water is entered at room temperature RTV molding compounds crosslinking to form elastomers are homogeneous and stable. They are filled into tubes. While mixtures of Examples 2a) and 2b) are supple and soft  can be squeezed out, the mixture of Example 2c) is viscous and is difficult to process.

The results of testing plasticizer emigration after ASTM C 1248 and the mechanical values according to ISO 8339 are in Table 2 reproduced.

Table 2

Example 3

a) 100 parts of a dimethylpolysiloxane each having a vinyl group in the terminal units and having a viscosity of 20,000 mPa.s at 23 ° C. are mixed in a well kneader with 19 parts of hexamethyldisilazane and 7 parts of water and stirred for 15 minutes at room temperature. 63 parts of pyrogenic silicon dioxide produced with a specific surface area of 300 m ² / g according to BET are added. The mixture thus obtained is kneaded first at room temperature for one hour and then at 100 ° C. for 2 hours. Then, by sucking off gaseous content from the kneader in this kneader, the pressure is reduced to 80 hPa (abs.), The remaining kneader contents are heated to 140 ° C. and kneaded at this temperature for 2 hours. After cooling to room temperature and aeration, 100 parts of the mixture thus obtained are diluted with 30 parts of the dimethylpolisiloxane each having a vinyl group in the terminal units and having a viscosity of 20,000 mPa.s at 23 ° C.

b) 62.3 parts of the mixture are mixed in a planetary mixer, their preparation in this example described above under b) was, first with 23.3 parts of tetra-i-butoxysilane, then with 8.7 parts of N- (2-aminoethyl) -3-aminopropyl-tri-n-butoxysilane and 4.0 parts of N- (2-aminoethyl) -3-aminopropyltriethoxysilane and last 1.7 parts of the reaction product, its production was described in Example 1 above under b) Room temperature and under the pressure of the surrounding atmosphere mixed. By lowering the pressure in the kneader finally gaseous constituents of the mass that bubbles in form the mass, removed.

It becomes a homogeneous, supple soft, stable and get crystal clear paste. It is filled into a tube.

c) Use of the paste, its production in this example described above under b) in at room temperature Crosslinking organopolysiloxane elastomers Two-component systems.

I. 750 parts of a dimethylpolysiloxane each having an Si-bonded hydroxyl group in the terminal units and having a viscosity of 300000 mPa.s at 23 ° C. in the terminal units with 620 parts of a dimethylpolysiloxane endblocked by trimethylsiloxy groups and having a viscosity of 10 mm ² / s mixed at 23 ° C. 25 parts of polyethylene propylene glycol with a molecular weight of approx. 3400 and an ethylene oxide content of approx. 45% are added and the mixture is briefly degassed with stirring. This is followed by the addition of 870 parts of calcium carbonate, the surface of which is coated with stearic acid (“coated chalk”) with a BET specific surface area of 20 m ² / g and of 250 parts of calcium carbonate, the surface of which is also coated with stearic acid, but a specific one BET surface area of about 1 m ² / g. The mixture thus obtained is then homogenized in vacuo.

II. The procedure described under I. is repeated with the modification that instead of 620 parts of a dimethylpolysiloxane end-blocked by trimethylsiloxy groups with a viscosity of 10 mm ² / s at 23 ° C., one with a viscosity of 100 mm ² / s at 23 ° C is used.

III. The procedure described under I. is repeated with the modification that instead of 750 parts of a dimethylpolysiloxane with a Si-bonded hydroxyl group in the terminal units and having a viscosity of 300000 mPa.s at 23 ° C, 1370 parts are used and the addition 620 parts of a dimethylpolysiloxane endblocked by trimethylsiloxy groups and having a viscosity of 10 mm ² / s at 23 ° C. are dispensed with.

The so obtained, in this example under I. and II. basic dimensions described above are homogeneous, supple, soft and stable. In contrast, it is in this Example under III. basic mass described above also homogeneous and stable, but putty and can be bad workmanship.

Each 100 parts of the I.-III. Base materials are described with 10 parts of the paste, the Preparation in this example described above under b) was mixed and vacuumed by gaseous  Ingredients exempt.

Three mixtures are obtained, which in case of use the basic masses I. and II. supple soft, in the case of Use of the basic mass III. putty and difficult to form, can be squeezed out and processed. The mixtures crosslink Room temperature to elastomers whose properties in the Table 3 are compiled.

Table 3

It can be seen from Tables 1 to 3 that the use of the dimethylpolysiloxanes with terminal trimethylsiloxy groups according to the invention, the viscosity of which is below 25 mm ² / s at 23 ° C., as a plasticizer in organopolysiloxane compositions which crosslink at room temperature to give compositions which are supple and soft are easy to process. The organopolysiloxane elastomers obtained from these compositions by crosslinking have a low stress value when stretched and do not bleed in contact with absorbent substrates such as natural stone, ie their use, for. B. in joints between natural stone leads to no edge zone pollution.

Claims (9)

1. Organopolysiloxane compositions (M) which can be crosslinked by condensation and which, as plasticizers, contain diorganopolysiloxane (W) of the general formula (I)
R ₃ Si- (O-SiR ¹ ₂ ) _n -SiR ₃ (I)
included in the
R and R ^{1 are} monovalent C ₁ -C ₈ hydrocarbon radicals which are optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ alkoxyalkyl or cyano groups and
n means values which correspond to a viscosity of the organopolysiloxane (W) of 5 to 25 mm ² / s at 25 ° C. 2. organopolysiloxane compositions (M) according to claim 1, in which the radicals R and R ^{1 are} unsubstituted hydrocarbon radicals having 1 to 6 carbon atoms. 3. Organopolysiloxahmassen (M) according to claim 1 or 2, which RTV-1 organopolysiloxane compositions (M) are available by mixing diorganopolysiloxane (W), α, ω- Dihydroxypolydiorganosiloxane (A), crosslinker (B) and Filler (C). 4. organopolysiloxane compositions (M) according to claim 3, in which as α, ω-dihydroxypolydiorganosiloxane (A) linear α, ω-dihydroxypolydiorganosiloxanes of the general formula (II)
HO- [R ² ₂ SiO] _m -H (II)
are used in which
R ² denotes monovalent C ₁ -C ₈ hydrocarbon radicals which are optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ alkoxyalkyl or cyano groups and
m means values which correspond to a viscosity of the HO-terminated organopolysiloxane (A) of 0.05 to 1000 Pa.s at 25 ° C. 5. organopolysiloxane compositions (M) according to claim 3 or 4, which 40 to 90 wt .-% organopolysiloxane (A), based on the entire organopolysiloxane mass (M) can be used. 6. organopolysiloxane compositions (M) according to claim 3 to 5, in which the crosslinking agent (B) is selected from silanes of the general formula (III)
R ³ _n SiX _(4-n) (III),
in the
R ³ are monovalent, optionally substituted by fluorine, chlorine, bromine, C ₁ -C ₄ -alkoxyalkyl, amino-C ₁ -C ₆ alkyl, amino-C ₁ -C ₆ - alkyleneamino or cyano-substituted C ₁ -C ₁₀ - hydrocarbon residues,
X is hydrogen, fluorine, chlorine or bromine atoms, C ₁ -C ₄ alkoxy, C ₁ -C ₄ acyloxy, amino, C ₁ -C ₄ alkylamino, C ₁ -C ₄ dialkylamino , -C ₁ -C ₆ alkylamido, - (NC ₁ -C ₄ alkyl) -C ₁ -C ₆ - alkylamido or Si-ON = bonded C ₃ -C ₆ ketoximo groups and
n denotes the values 0, 1 or 2,
and condensation products of these silanes. 7. organopolysiloxane compositions (M) according to claim 3 to 6, which 0.5 to 15 wt .-% crosslinker (B), based on the entire organopolysiloxane mass (M) can be used. 8. organopolysiloxane compositions (M) according to claim 3 to 7, which the filler (C) is selected from carboxylic acid coated chalk, quartz, diatomaceous earth, Calcium silicate, zirconium silicate, zeolites, metal oxides, Barium sulfate, calcium carbonate, gypsum and silica. 9. organopolysiloxane compositions (M) according to claim 3 to 8, which 2 to 40 wt .-% filler (C) based on the total Organopolysiloxane mass (M) can be used.