DE3809614A1 - Process for producing ceramic material - Google Patents

Abstract

The invention relates to a process for producing ceramic material based on silicon carbide and/or silicon nitride, characterised in that a) a silicon polymer containing SiH bonds, selected from the group consisting of organopolysilanes, organopolycarbosilanes or polysilazanes, in the presence of a hydrosilylation catalyst is brought into contact with an aliphatic compound which contains at least one multiple bond and b) the reaction product from a) is pyrolysed in an inert atmosphere, in vacuo, in ammonia or hydrogen-containing atmosphere at temperatures in the range from 700 to 1500@C.

Description

The invention relates to a method for producing Ceramic material based on silicon carbide and / or silicon nitride.

EP-A2 02 06 449 describes a process for the production of Ceramic material based on silicon carbide and silicon nitride known, with the polysilazanes before pyrolysis with Water vapor or oxygen-enriched water vapor to be treated at those used in pyrolysis To make temperatures infusible. Unfortunately this method leads to the incorporation of oxygen which the pyrolysis results in a high proportion of SiO₂. This worsens the high temperature properties of the obtained Ceramic material considerably.

The object of the invention is to avoid the disadvantages the prior art, a method for producing Ceramic material based on silicon carbide and / or silicon nitride to provide the manufacturing of Molded articles, in particular fibers and protective coatings, enables.  

The invention relates to a method for manufacturing of ceramic material based on silicon carbide and / or Silicon nitride, which is characterized in that

• a) a silicon polymer containing SiH bonds, selected from the group of organopolysilanes, organopolycarbosilanes or polysilazanes, in the presence of a hydrosilylation catalyst with an aliphatic compound, which contains at least one multiple bond, in Is brought in contact and
• b) the reaction product according to a) in an inert atmosphere, in a vacuum, containing ammonia or hydrogen Atmosphere at temperatures in the range of 700 to 1500 ° C is pyrolyzed.

The treatment according to a) removes the SiH bonds Silicon polymers infusible in those for the Pyrolysis according to b) applied temperatures. This is the Pyrolysis of moldings such as fibers or protective coatings only possible. A melting or melting during the Pyrolysis would destroy the shape.

Hydrosilylation catalysts are in the sense of the invention Catalysts that add Si-bonded hydrogen promote aliphatic multiple bonds. Such Catalysts are known per se and, for example, in J.L. Speier, Adv. Organomet. Chem. 17, 407-448 (1979) or W. Noll, Chemistry and Technology of Silicones, pages 53, 54 Academic Press Inc., Orlando described what followed in this Connection is expressly referred to.

Catalysts preferably used are compounds of Platinum and rhodium such as bis (ethylenediamine) platinum (II) chloride, Platinum (II) 2,4-pentanedionate, bis (triphenylphosphine) platinum (II) chloride,  Tetrakis (triphenylphosphine) platinum, dihydrogenhexachloroplatinate (IV), Tri-n-butylphosphine platinum (II) chloride dimer, Chlorine (2,2 ′, 2 ′ ′ - terpyridine) platinum (II) chloride dihydrate, cis-dichlorobis (acetonitrile) platinum (II), cis-dichloro (2,2′-bipyridine) platinum (II), dichlorobis (benzonitrile) platinum (II), Dichloro (1,5-cyclooctadiene) platinum (II), 2-hydroxyethanethiolate (2,2 ′, 2 ′ ′ - terpyridine) platinum (II) nitrate, Oxygen bis (triphenylphosphine) platinum (II), platinum (II) hexafluoroacetylacetonate, Tris (dimethylphenylphosphine) norbornadiene rhodium (I) hexafluorophosphate, Bis (1,2-diphenylphosphine) ethannorbornadienrhodium (I) hexafluorophosph-hat, Chlorobis (ethylene) rhodium (I) dimer, chlorocarbonylbis (triphenylphosphine) rhodium (I), Chloro (1,5-cyclooctadiene) rhodium (I) dimer, Chlorodicarbonylrhodium (I) dimer, chlorotris (triphenylphosphine (rhodium (I), Dicarbonylacetylacetonate rhodium (I), Hexarhodiumhexadecacarbonyl, hydridocarbonyltris (triphenylphosphine) rhodium (I), Rhodium (II) acetate dimer, rhodium (III) acetylacetonate.

Preferably 0.01 to 1% by weight of catalyst are obtained silicon polymer containing SiH bonds used, used.

The silicon polymers containing SiH bonds are selected from the group of organopolysilanes, organopolycarbosilanes and polysilazanes.

Mixtures and copolymers of 2 or 3 components of polymers selected from the group of organopolysilanes, organopolycarbosilanes and polysilazanes be used.

Containing SiH bonds used according to the invention Organopolysilanes are preferably made up of units of Formulas  

built up, with
R 'are each independently hydrogen, halogen, alkyl, cycloalkyl, alkenyl or aryl and
R '' are halogen, alkyl, cycloalkyl, alkenyl or aryl radical, and y are in the range from 0 to 20 and z are in the range from 1 to 10,000.

Preferred examples of alkyl radicals are methyl, Ethyl, n-propyl, iso-propyl, n-butyl, sec.-butyl, tert-butyl, n-pentyl and n-hexyl, for alkenyl the vinyl and allyl radical, for cycloalkyl radicals the cyclopentyl and cyclohexyl radical and for aryl radicals the phenyl and Tolyl group.

Containing SiH bonds used according to the invention Organopolycarbosilanes are preferably made up of units of formula

built up, with
R 'each independently represents hydrogen, halogen, alkyl, cycloalkyl, alkenyl or aryl and x is in the range from 1 to 20, y in the range from 1 to 20 and z in the range from 1 to 10,000.

Preferred examples of alkyl radicals are the methyl, Ethyl, n-propyl, iso-propyl, n-butyl, sec.-butyl, tert-butyl, n-pentyl and n-hexyl, for alkenyl the vinyl and allyl radical, for cycloalkyl radicals the cyclopentyl and cyclohexyl radical and for aryl radicals the phenyl and Tolyl group.

Polysilazanes containing SiH bonds used according to the invention are preferably made up of units of the formulas

built up, with
R 'each independently represents hydrogen, halogen, alkyl, cycloalkyl, alkenyl, aryl, amino, alkylamino, dialkylamino, arylamino or diarylamino radical and x in the range from 1 to 20, y in the range from 1 to 20 and z are in the range from 1 to 10,000.

Preferred examples of alkyl radicals are the methyl, Ethyl, n-propyl, iso-propyl, n-butyl, sec.-butyl, tert-butyl, n-pentyl and n-hexyl, for alkenyl the vinyl and allyl radical, for cycloalkyl radicals the cyclopentyl and cyclohexyl radical and for aryl radicals the phenyl and Tolyl group.

The production of these silicon polymers containing SiH bonds is known per se.  

Thus, the production of those to be used according to the invention Organopolysilanes, for example from C. L. Schilling Jr., Brit. Polym. J. 18, 355 (1986), by dehalogenation of Chlorosilane mixtures containing methyldichlorosilane Alkali metals, from US-A 31 46 249 by reaction of methyldichlorosilane with potassium or sodium, from US-A 43 10 482 Disproportionation of chlorine-containing organodisilane mixtures and reaction of the chloropolysilane obtained with Lithium aluminum hydride and by C. Aitken, J.F. Harrod, J. Organomet. Chem. 279, C11-C13 (1985) by polymerization of phenylsilane in the presence of titanocene compounds described.

The production of organopolycarbosilanes to be used according to the invention is used, for example, by EPA 21 844 Conversion of polysilanes by pressure and temperature, of EP-A 1 23 162 by reacting methyldichlorosilane and silane mixtures containing chloromethylalkylchlorosilanes with alkali metals and from US-A 46 31 179 by polymerization of 1,3-disilacyclobutane in the presence of platinum catalysts described.

The production of polysilazanes to be used according to the invention is described, for example, by D. Seyferth, G. Wiseman, Polym. Prepr. (Am. Chem. Soc. Div. Polym. Chem.) 25, 10-12 (1984) by reacting methyldichlorosilane or dichlorosilane with ammonia, from EP-A 1 46 802 by reacting trichlorosilane with hexamethyldisilazane and from EP-A 2 08 630 Implementation of chlorosilane mixtures containing methyldichlorosilane with ammonia and subsequent catalytic polymerization with strong acids, especially trifluoromethanesulfonic acid, described.

Another method of making polysilazanes are alkylchlorodisilanes, which are preferably in a mixture  with alkylchlorosilanes, arylchlorosilanes or chlorosilanes be used with ammonia, primary amines, secondary Amines, diamines, hydrazines and alkyl or aryl hydrazines or mixtures of the above nitrogen compounds and optionally in the presence of catalysts such as Tetraalkylammonium, phosphonium halides, high-boiling tertiary amines or phosphines, e.g. B. tridecylamine, tribenzylamine, Polymerized triphenylphosphine.

Aliphatic compounds used according to the invention which contain at least one multiple bond are preferred Alkanedienes, alkynes or with unsaturated, aliphatic Disilazanes substituted by hydrocarbons.

Examples of aliphatic compounds that have at least one Containing multiple bonds are compounds of the general Formulas

R-C≡C-R,

where R is hydrogen, methyl or phenyl,

R¹-C≡C- (CR¹₂) _x -C≡C-R¹,

where R¹ is hydrogen or methyl and x is in the range from 0 to 14,

R²₂C = CR²- (CR²₂) _x -CR² = CR²₂,

where R² is hydrogen or methyl and x is in the range from 0 to 14, or

R⁴HC = CH-SiR³₂-NH-SiR³₂-CH = CHR⁴,

where R³ is methyl, n-propyl, n-butyl, iso-propyl, iso-butyl or phenyl radical and R⁴ hydrogen or methyl radical mean.

Acetylene, diacetylene, dimethylacetylene, Diphenylacetylene, Butadiene, Isoprene, Allen, Methyl Acetylene, 2,3-dimethylbutadiene (1,3), 2,3-dimethylbutadiine, 1,4-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 1,6-heptadiin, 1,7-octadiene, 1,7-octadiin and Divinylbenzene used. In particular, acetylene, 2,3-dimethylbutadiene (1,3)  and divinyltetramethyldisilazane used.

In a preferred embodiment of the invention The procedure is such that the one containing SiH bonds Silicon polymer before shaping according to known Processes such as spinning into fibers or application to substrates is mixed with the hydrosilylation catalyst and this mixture with an aliphatic compound which contains at least one multiple bond becomes. A largely homogeneous mixing of the silicon polymer to achieve with the hydrosilylation catalyst one preferably dissolves both components in an organic one Solvent and removes the solvent, after both components are completely detached. Examples for solvents are aromatics such as toluene, chlorinated Hydrocarbons such as chloroform, methylene chloride and Carbon tetrachloride, or ethers such as tetrahydrofuran. The However, hydrosilylation catalyst can also be melted Polymer are stirred.

Preferably the aliphatic compounds, at least contain a multiple bond, in the gaseous phase used or via inert carrier gases such as nitrogen, argon or carbon dioxide, with an overpressure applied can be used to increase concentration. The exposure to the gaseous phases is so long carried out until the reaction products according to a) in the case of of the pyrolysis according to b) applied temperatures infusible are, the initial temperature of the gaseous compounds must not be higher than the melting point of the Silicon polymers containing SiH bonds. This poses however, no problems for the specialist since he or knows melting points or determine them in a simple manner can. Preferably the initial temperature is gaseous phases at least 10 to 20 ° C below the  Melting point of the silicon polymer. The duration of the application as well as the amount of aliphatic compounds that contain at least one multiple bond, is according to the a) Depending on the substrates used, but for the expert easily ascertainable through simple routine tests.

The reaction product according to a) is in an inert atmosphere, in a vacuum, in an atmosphere containing ammonia or hydrogen at temperatures in the range of 700 to 1500 ° C, preferably 800 to 1300 ° C, to silicon carbide and / or silicon nitride pyrolyzed.

In particular nitrogen and argon are used as inert gases.

The following examples were, unless otherwise stated, at a pressure of 0.10 MPa (abs.) and a temperature of 20 ° C.

example 1 Production of a polysilazane containing SiH bonds

In a 2-liter three-necked flask with reflux condenser and gas inlet tube, 200 g of fissile disilane, consisting of a mixture of trimethyltrichlorodisilane and dimethyltetrachlorodisilane of the approximate composition (CH₂) _2.6 Si₂Cl _3.4 , were obtained from the high-boiling fraction of the Rochow synthesis of dimethyldichlorosilane (W. Noll, Chemistry and Technology of Silicones, Academic Press Inc., Orlando 1968, pages 26 to 27) dissolved in 1500 ml of toluene under argon. Subsequently, gaseous methylamine was introduced at 20 ° C. until no more gas was absorbed. The mixture was then heated to reflux for 15 minutes. After cooling, the methylamine hydrochloride was filtered off and washed with 100 ml of toluene, which contained methylamine in solution. The filtrate was freed from toluene by distillation. As soon as the bottom residue had reached a temperature of 200 ° C, a water jet vacuum was applied until no more volatile compounds passed over. 118.1 g of the desired aminodisilane were obtained. 94.4 g of this aminodisilane were mixed in an argon atmosphere in a quartz flask with 2 wt .-% n-Bu₄NBr and heated to reflux. Low-boiling product portions were drawn off via a lateral condensate drain until a bottom temperature of 440 ° C. was reached. 37.2 g of a polysilazane melting at 165 ° C. were obtained.

Elemental analysis:

Si = 36.3%
C = 33.6%
H = 8.4%
N = 18.2%
O = 3.6%
Cl = 0.02%

Gel chromatogram:

There was a bimodal molecular weight distribution with Maximas at 2000 g / mol and 4000 g / mol.

Example 2

50 g of the polymer obtained according to Example 1 were dissolved in 150 ml of toluene. 1 ml of a solution of 1 g of π- acetylacetonylnorbornenylplatinacetylacetonate in 100 ml of toluene was added and the solvent was evaporated off again. The platinum-containing polymer was melted, degassed in vacuo and filled into an electrically heated spinning head made of V4A steel. After the polymer had melted at 170 ° C., it was pressed by pressing 8 bar argon through a nozzle with a diameter of 0.3 mm and fed to a winding device, by means of which it was wound up at a speed of 120 m / s. The polysilazane fiber obtained was then cut from the bobbin and placed in an aluminum boat which was placed in a glass tube of 40 mm in diameter and 600 mm in length which was thermostatted at 110 ° C. After briefly flushing with argon, acetylene was passed through at a rate of 20 l / h and the glass tube was heated from 110 ° C. to 170 ° C. within 20 minutes. The boat with the fibers was removed at 170 ° C. and heated in a tube furnace in a stream of argon at a rate of 100 ° C. to 1050 ° C. The fibers obtained showed a tensile strength of 51 to 88 kg / mm² with a diameter of 28 microns.

Example 3

According to Example 1, a mixture of 300 g of cleavable disilane of the composition Me _2.6 Si₂Cl _3.4 and 100 g of trichlorosilane was dissolved in 3 l of toluene and reacted with methylamine. After removing the amine hydrochloride precipitate and distilling off the solvent at 100 ° C. in vacuo, 277 g of a golden, cloudy, oily product were obtained. 100 g of the aminodisilane mixture obtained were mixed with 2% by weight of methyltridecylammonium chloride and, as described under 1, heated to a temperature of 430 ° C. in the course of 5 hours. With the elimination of methylamine, propene and hydrogen and the formation of methylhydrogensilanes, 75 g of a glass-like brittle polymer were obtained. The polymer had a melting point of 160 ° C and was soluble in toluene, tetrahydrofuran, chloroform, methylene chloride and carbon tetrachloride.

Elemental analysis:

N = 23.2%
Cl = 0.04%
Si = 34.8%

Gel chromatography:

Maximum at 20,000 g / mol and shoulder at 2000 g / mol.

Example 4

50 g of the polymer obtained according to Example 3 were dissolved in 150 ml of toluene. 1 ml of a solution of 1 g of π -cyclooctadienylplatinum dichloride in 100 ml of toluene was added and the solvent was evaporated off again. The polymer was spun into fibers as described in Example 2 at a temperature of 160 ° C. The fiber was then cut from the spool, placed in an alumina boat and placed in a thermostatted glass tube 40 mm in diameter and 600 mm in length. In it, the fiber was heated to 110 ° C, at the same time passing an argon flow of 20 l / h, which was previously passed through a wash bottle with isoprene and saturated at 20 ° C with this gas. At intervals of half an hour, the temperature in the tube was increased in 10 ° C steps up to 160 ° C. The crosslinked fiber was then pyrolyzed in a stream of argon as described in Example 2 without tension. With a fiber diameter of 30 µm tensile strengths of 36-42 kp / mm² were measured.

Example 5

A solution of 244 g of trichlorosilane in 3 l of toluene was mixed with Methylamine reacted until gas was no longer absorbed. After the heat of reaction had subsided, the mixture was still Heated at reflux for 15 min. Then allowed to cool,  filtered the precipitated methylamine hydrochloride Argon atmosphere and evaporated the clear filtrate in a water jet vacuum at 100 ° C on a rotary evaporator. You got 156 g of a colorless, slightly cloudy oil. 87.5 g of Aminodisilane obtained according to Example 1 were with 12.5 g of the methylaminohydrosilane prepared according to the above. After adding 2 g of tetraoctylammonium bromide the reaction mixture in a 250 ml flask using a Patio heater heated to 460 ° C. Here, 27.3 g distilled volatile products and 59.1 g of one was obtained 170 ° C melting solid.

Elemental analysis:

N = 18.3%

Gel chromatogram:

There is a trimodal distribution with Maximas at 2000, 4000 and 20,000 g / mol.

Example 6

50 g of the polymer obtained according to the example were in 150 ml Toluene dissolved and with 1 ml of a 1% solution of added catalyst described in Example 2. To After concentration, a spinnable resin was obtained, which like already described, was spun. Fiber networking was carried out as described in Example 4, with the crosslinking agent 2,3-dimethylbutadiene-1,3 was used. The wash bottle was at a temperature of 50 ° C brought, the exposure time at the respective temperature was identical to that of Example 4.

After pyrolysis, black SiC fibers were obtained. At a With a diameter of 40 µm, the tensile strength was 35-45 kp / mm². Pyrolysis in a pure hydrogen atmosphere gave gold-colored ceramic fibers with significantly reduced carbon content and still good tensile strength.

Example 7

52 g of the aminodisilane prepared according to Example 1 were mixed with 2 wt .-% trioctylamine and in a 100 ml  autoclave filled. The mixture was inside heated from 1 h to 415 ° C. Then you heated inside from 5 h to a maximum of 530 ° C, a pressure of 120 bar was reached. Then you cooled down and relaxed. The solid content of the autoclave was extracted with toluene. The solution was filtered and concentrated. At a Temperatures of 260 ° C became volatile in a high vacuum away. 44.5 g of one was obtained as residue melting at 135 ° C, soluble in toluene and tetrahydrofuran Resin.

Elemental analysis:

C = 31.0%
H = 7.6%
N = 17.7%
Si = 38.0%
O = 5.7%
Cl = 0.5%

Gel chromatogram:

Almost monomodal distribution with maximum at 1500 g / mol. Light shoulder at 500 g / mol.

Example 8

The introduction of the norbornene-acetylacetonate-platinum complex into the polymer according to Example 7 was carried out according to Example 2. The polymer was spun at 135 ° C and opened a 6 cm diameter steel spool spooled in a thin layer. This coil was placed in a chamber furnace for 24 hours in an acetylene atmosphere from 1 to 2 bar pressure at one temperature exposed from 70-80 ° C. Then the acetylene removed by evacuation and by an argon atmosphere replaced. The furnace was heated at a rate of 100 ° C / h heated to 1000 ° C and then cooled immediately. The Bobbin was removed and the fibers were cut down. The tensile strength values were in the range of 28-92 kp / mm² with a fiber diameter of 28 µm.  

Example 9

150 g of a mixture of trimethyltrichlorodisilane and dimethyltetrachlorodisilane and 50 g of trichlorosilane were in 1.5 l of toluene dissolved. The mixture was introduced with vigorous stirring Mixture of methylamine and ammonia in a volume ratio of 5: 1 a. After saturation was reached, the mixture was refluxed for 15 minutes cooked. After cooling, the mixture was concentrated at 100 ° C. 88 g of a golden yellow resin were obtained as residue, which in toluene, tetrahydrofuran, carbon tetrachloride, Chloroform and methylene chloride was soluble and one Melting point of 105 ° C had.

Elemental analysis:

C = 24.4%
N = 26.3%
Cl = 0.5%
H = 5.4%
Si = 42.5%

Gel chromatogram:

Trimodal distribution; weak maximum at 350 g / mol, broad, strong maximum at 2000 g / mol, narrower, strong maximum at 5000 g / mol.

Example 10

50 g of the polymer prepared according to Example 9 were in 150 ml of toluene dissolved. For this, 1 ml of a 1% strength was added Solution of platinum acetylacetonate and constricted. At a The temperature of 110 ° C was the polymer according to the previous attempts spun. A bundle of fibers was crosslinked according to Example 4 by an argon flow, which with Divinyltetramethyldisilazane was saturated passed over has been. The initial temperature of the fiber was 70 ° C, the temperature of the silazane evaporator at 60 ° C. In half an hour Time intervals the temperature was around 10 ° C raised, both that of the pipe in which the  Fibers, as well as those of the evaporator, the Evaporator temperature 10 ° C below that of the fibers. After reaching a maximum fiber temperature of 120 ° C these were pyrolyzed in a stream of argon at 1050 ° C. The measured Tensile strengths were in the range of 25-62 kp / mm² with a fiber thickness of 42 µm.

Example 11

According to Example 1 of EP-A 00 21 844 was by reacting Dimethyldichlorosilane with sodium dispersion in toluene an insoluble and infusible dimethylpolysilane. According to Example 4 of the EP-A mentioned, 30 g of Polysilane in a 100 ml, electrically heated Autoclave converted into a polycarbosilane at 460 ° C. After an 8-hour test period, the mixture was cooled, relaxed and the residue extracted with hexane. After evaporating the Solvents were volatiles at 200 ° C on High vacuum removed. 14.2 g of a soluble, were 90 to 95 ° C melting solid isolated.

Elemental analysis:

C = 40.9%
H = 11.1%
Si = 48.2%

Gel chromatogram:

Monomodal distribution with a maximum at 900g / mol.

Example 12

All of the polycarbosilane prepared in Example 11 was dissolved in 50 ml of toluene. There were 0.5 ml of a 1% Solution of bis (acetonitrile) platinum dichloride in toluene added and concentrated the solution. The polymer obtained was melted at 100 ° C in the spinning head and as already described spun. The fibers thus produced were cut from the spool and in a porcelain bowl  put a 3 l, thermostatic steel pot, which was purged with argon. In addition, one was given small bowl with 1 ml of isoprene in the container and heated after sealing at a rate of 10 ° C / h to 80 ° C. After 16 hours the fibers were removed and pyrolyzed. The SiC fibers obtained had a diameter of 55 µm and had a tensile strength of 30-35 kp / mm² on.

Claims (9)

1. A method for producing ceramic material based on silicon carbide and / or silicon nitride, characterized in that

• a) a silicon polymer containing SiH bonds, selected from the group of organopolysilanes, organopolycarbosilanes or polysilazanes, is brought into contact with an aliphatic compound which contains at least one multiple bond in the presence of a hydrosilylation catalyst and
• b) the reaction product according to a) is pyrolyzed in an inert atmosphere, in a vacuum, in an atmosphere containing ammonia or hydrogen at temperatures in the range from 700 to 1500 ° C.

2. The method according to claim 1, characterized in that 0.01 to 1% by weight of catalyst, based on the Silicon polymer containing SiH bonds used will. 3. The method according to claim 1 or 2, characterized in that organopolysilanes, constructed from details of the formula in which
R 'are each independently hydrogen, halogen, alkyl, cycloalkyl, alkenyl or aryl and
R '' are halogen, alkyl, cycloalkyl, alkenyl or aryl radical, where y is in the range from 0 to 20 and z is in the range from 1 to 10,000, are used. 4. The method according to claim 1 or 2, characterized in that organopolycarbosilanes, constructed from details of the formula in which
R 'each independently represents hydrogen, halogen, alkyl, cycloalkyl, alkenyl or aryl and
x in the range from 1 to 20, y in the range from 1 to 20 and
x are in the range from 1 to 10,000 can be used. 5. The method according to claim 1 or 2, characterized in that polysilazanes, constructed from details of the formulas in which
R 'each independently represents hydrogen, halogen, alkyl, cycloalkyl, alkenyl, aryl, amino, alkylamino, dialkylamino, arylamino or diarylamino radical and
x in the range from 1 to 20, y in the range from 1 to 20 and
z range from 1 to 10,000 can be used. 6. The method according to one or more of claims 1 to 5, characterized in that as aliphatic compounds, that contain at least one multiple bond, Alkanedienes, alkynes or with unsaturated, aliphatic Disilazanes substituted by hydrocarbons are used will. 7. The method according to one or more of claims 1 to 6, characterized in that alkynes of the formulas RC≡CR, where R is hydrogen, methyl or phenyl, orR¹-C≡C- (CR¹₂) _x -C≡C- R¹, where R¹ is hydrogen or methyl and x is in the range from 0 to 14, can be used. 8. The method according to one or more of claims 1 to 6, characterized in that alkane dienes of the formula R²₂C = CR²- (CR²₂) _x -CR² = CR²₂, where R² is hydrogen or methyl and x is in the range from 0 to 14, be used. 9. The method according to one or more of claims 1 to 6, characterized in that disilazanes of the formula R⁴HC = CH-SiR³₂-NH-SiR³₂-CH = CHR⁴, where R³ is methyl, n-propyl, n-butyl, iso-propyl, iso-butyl or phenyl radical and R⁴ hydrogen or methyl radical mean be used.