Siloxi-Polytetrahydrofuran.

0001Polytetrahydrofurans (poly-THF) or polyoxibutylene glycols are compounds of the general formula II<chemistry id="chem0001" num="0001"><img file="EP0509271A2_D0001.tif" /></chemistry>Poly-THF is usually produced by the cationic polymerization of tetrahydrofuran (THF), whereby Bronsted or Lewis acids can be used as catalysts. The production of poly-THF is described for example in DE-A 28 01 792, EP-A 241 890 and EP-A 126 471. The degree of polymerization n of the poly-THF indicates the number of oxibutane-1,4-diyl units from the monomeric THF per poly-THF molecule and can have a value of 3 - corresponding to an average molecular weight MG of 234 daltons - up to about 70 - corresponding to an average molecular weight MG of about 5000 daltons. Higher degrees of polymerization are possible, but such poly-THF species are of less technical importance. In the case of THF polymerization, poly-THF molecules of different chain lengths, that is to say different degrees of polymerization, are generally formed, which is why the poly-THF formed during the polymerization is not a uniform compound, but a statistical mixture of poly-THF that is more or less wide, depending on its type of preparation Represents individuals of different molecular weights. The experimentally determined molecular weight of the poly-THF is thus a statistical quantity and is referred to here and hereinafter as "average molecular weight (MG)" or as "average molecular weight". The average molecular weight MG of the poly-THF can be determined by various methods, for example by means of osmometry, gel permeation chromatography or by determining the hydroxyl end groups.

0002Poly-THF is used as a diol building block for the production of high-quality polyurethanes and as such has a decisive influence on the properties of the polymers produced from it. The properties of these polymers based on the use of poly-THF as a diol building block, such as high impact strength, high mechanical level without tempering, are determined not only by the amount of poly-THF used for polymer production, but also to a large extent by the type of the poly-THF used. For example, the elastic properties of elongation at break and impact strength of a polyurethane produced using poly-THF with an average molecular weight of 2000 daltons differ significantly from those of a polyurethane which was produced under otherwise identical conditions with the addition of poly-THF with an average molecular weight of 1000 daltons . Of particular economic interest are, for. B. the following types of Poly-THF: Poly-THF 250 (MG: approx. 250 Dalton, n (degree of polymerization): approx. 3); Poly-THF 650 (MW: approx. 650 daltons, n: approx. 9); Poly-THF 1000 (MW: approx. 1000 daltons, n: approx. 14); Poly-THF 2000 (MW: about 2000 daltons, n: about 27); Poly-THF 2900 (MG: approx. 2900 Dalton, n: approx. 40) and Poly-THF 4500 (MG: approx. 4500 Dalton, n: approx. 62).

0003Polytetrahydrofurans with higher average molecular weights generally have a significantly higher viscosity and their softening point is generally at significantly higher temperatures than is the case with polytetrahydrofurans with a relatively low average molecular weight. For example, the temperature at the softening point of Poly-THF 250 is -14 ° C, whereas this is already at 26 ° C for Poly-THF 1000 and the viscosity of Poly-THF 250 is 158 mPa 's (at 20 C), meanwhile the viscosity of Poly-THF 1000 is almost twice as high even at a temperature of 30 ° C with 440 mPa 's. In view of these facts, it becomes clear that higher molecular weight poly-tetrahydrofurans are more difficult and more difficult to handle, to dose and to process than lower molecular weight representatives of these polymers.

0004However, since polyurethanes, which contain long-chain, high-molecular poly-THF as a diol building block, are distinguished by a particularly favorable low-temperature behavior, there is a need for chemically modified poly-tetrahydrofurans which not only function as conventional poly-tetrahydrofurans as a diol building block and soft segment in polyurethanes and can fill, but are also characterized by better processing properties. Furthermore, it would be extremely desirable if, as a result of the use of such poly-THF derivatives, the processability of the polymers produced from them could also be improved.

0005The present invention was therefore based on the object of finding poly-THF derivatives which, on the one hand, can take over and fill out the function of conventional polytetrahydrofurans as a diol building block in polyurethanes, but on the other hand should differ from conventional polytetrahydrofurans in that they can be processed more easily and, moreover, also polymer product made therefrom should impart improved properties, such as easier processability. Furthermore, a process for the production of such poly-THF derivatives had to be made available.

0006Accordingly, the new siloxi polytetrahydrofurans of the formula I<chemistry id="chem0002" num="0002"><img file="EP0509271A2_D0002.tif" /></chemistry>in which the residues R¹ and R² are the same or different and for a C₁- to C₁₀Alkyl group, a C₂- to C₁₀Alkenyl group, a C₁- to C₁₀Haloalkyl group, a C₁- C₁ o-aminoalkyl group, a C₁- to C₁₀-Hydroxyalkyl group, a C₆- to C₁₀Aryl group, a C₇- to C₁₂Aralkyl group and / or a C₁- to C₁₀Alkoxy group, the index n is an integer from 2 to 150 and the index m is an integer from 1 to 500.

0007Furthermore, a process for the preparation of siloxi-polytetrahydrofurans of the formula I<chemistry id="chem0003" num="0003"><img file="EP0509271A2_D0003.tif" /></chemistry>in which the residues R¹ and R² and the indices n and m have the meaning given above, which is characterized in that polytetrahydrofuran of the general formula II<chemistry id="chem0004" num="0004"><img file="EP0509271A2_D0004.tif" /></chemistry>with a silicon compound of the general formula III<chemistry id="chem0005" num="0005"><img file="EP0509271A2_D0005.tif" /></chemistry>in which the groups X and Y are identical or different and represent a hydrogen atom, a halogen atom, a C₁- to C₄Alkoxy group and / or a C₂- to C₈-Dialkylamino group, in the presence or absence of an acidic or basic catalyst and thereby using a molar ratio of polytetrahydrofuran II: silicon compound III of 1: 1 to 2: 1.

0008In addition, new polyurethanes were constructed from diisocyanates, diols and optionally diamines, containing groups of the formula Ia as a diol component<chemistry id="chem0006" num="0006"><img file="EP0509271A2_D0006.tif" /></chemistry>in which the residues R¹ and R² and the indices n and m have the meaning given above.

0009The siloxi-polytetrahydrofurans according to the invention are therefore molecules composed of at least four poly-THF units which are connected to one another via at least one siloxi bridge. However, the siloxi-polytetrahydrofurans according to the invention can also be composed of up to 501 poly-THF units and up to 500 siloxi units, namely when the index m has the number 500. However, siloxi-polytetrahydrofurans are preferably produced and used in which the index m has an integer value from 1 to 20.

0010The index n of the polytetrahydrofuran units, which is also referred to as the degree of polymerization, can have an integer value from 2 to 150. Among the compounds according to the invention, preference is given to those in which n has an integer value from 3 to 70. Since the polytetrahydrofurans of certain average molecular weights used to prepare the compounds according to the invention generally consist of a statistical mixture of individual poly-THF macromolecules of different molecular weights, that is to say are polydisperse systems, that the index n of the individual poly-THF units in the compounds according to the invention varies according to the starting material used and that the siloxi-polytetrahydrofurans produced from such polydisperse starting materials are also polydisperse systems.

0011The leftovers R¹ and R² the siloxi groupings can be the same or different and for a C₁- to C₁₀Alkyl group, preferably a methyl group, a C₂- to C₁₀-Alkenyl group, preferably a vinyl or allyl group, a Ci to C₁₀-, preferably a Ci to C.₄Haloalkyl group, a Ci to C₁₀-, preferably a Ci to C.₄-Aminoalkyl group, a Ci to Cio, preferably a Ci to C₄-Hydroxyalkyl group a C₆- to C_ioAryl group, preferably a phenyl group, a C₇- to C₁₂Aralkyl group, preferably a benzyl group and / or a Ci to C₁₀-, preferably a Ci to C.₄-Alkoxy group. Siloxi-polytetrahydrofurans in which the residues R¹ and R² Functional groups, such as hydroxyl groups, amino groups and halogen atoms, can advantageously be used to produce highly crosslinked or functionalized polyurethanes.

0012According to the invention, the siloxi-polytetrahydrofurans can be reacted with polytetrahydrofurans of the general formula 11<chemistry id="chem0007" num="0007"><img file="EP0509271A2_D0007.tif" /></chemistry>with a silicon compound of the general formula III<chemistry id="chem0008" num="0008"><img file="EP0509271A2_D0008.tif" /></chemistry>getting produced.

0013In the silylene compounds of the formula III, the groups X and Y can be the same or different, they are expediently the same and, for a hydrogen atom which is generally anionic in character and therefore could also be referred to as a hydrido group, a halogen atom, preferably a fluorine , Chlorine or bromine atom, a C₁- to C₄Alkoxy group, preferably for the methoxy group and / or a C.₂- to C₈Dialkylamino group, preferably for the dimethylamino group. Cycloaliphatic secondary amino groups with 2 to 5 carbon atoms in the ring, which may optionally also contain an oxygen atom in the ring, for example the aziridino, pyrrolidino, piperidino or morpholino group, can also represent X and / or Y as dialkylamino groups. The leftovers R¹ and R² these silylene compounds have the meaning already mentioned. Such silylene compounds are commercially available or can be prepared by known processes, for example by Comprehensive Organometallic Chemistry, Vol. 2, pp. 306-322, Pergamon Press, New York 1982.

0014The reaction between the polytetrahydrofurans II and the silylene compounds III can be carried out in the presence or absence of catalysts, and if catalysts are used, depending on the nature of the silylene compounds used, acidic, basic or transition metal catalysts are used.

0015Halogenated silylene compounds Illa, for example dimethyldichlorosilane<chemistry id="chem0009" num="0009"><img file="EP0509271A2_D0009.tif" /></chemistry>used as the starting material, the reaction is preferably carried out in the presence of an auxiliary base, the task of which is to intercept the hydrogen halide formed in the course of the polycondensation. Accordingly, practically all types of bases, mineral bases and organic bases can be used, but organic bases are preferred in general, and amines, in particular tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, benzyldimethylamine, benzyldibutylamine, dibutylbenzylamine, etc., are preferred in general used in the method according to the invention. However, basic, organic ion exchangers which preferably carry tertiary amino groups as basic centers can also advantageously be used for this purpose. The type of polymer matrix on which the organic ion exchanger is based is generally not critical to the success of the process.

0016If organic and inorganic auxiliary bases are used, they are usually used in amounts of 2 to 4, preferably 2 to 2.5, mol per mole of the dihalosilane compound Illa in question. Are basic organic or inorganic ion exchangers, such as Hostarex @ 1327 (Hoechst), Amberlite @ LA2 (Rohm &amp; Haas) or Lewatit @ M500 (Bayer) are used, these are added to the reaction mixture in amounts of 2 to 4, preferably 2 to 2.5, equivalents / mol of the dihalo compound Illa .

0017Of course, the reaction of poly-THF with dihalosilanes can also be carried out in the absence of an auxiliary base. It has proven advantageous here to strip the hydrogen halide formed from the organic reaction medium, for example by passing an inert gas, such as nitrogen, through the reaction mixture.

0018The preparation of the compounds according to the invention, starting from bis (dialkylamino) dialkylsilanes IIIc<chemistry id="chem0010" num="0010"><img file="EP0509271A2_D0010.tif" /></chemistry>in which the residues R⁵ to R⁸ are the same or different and for a C₁- to C₄-Alkylgruppe or in which the aliphatic radicals R⁵ and R⁶ and / or R⁷ and R⁸ together with the nitrogen atom can form a 3- to 6-membered ring, for example an aziridine, pyrrolidine, morpholine or piperidine ring, and poly-THF is preferably carried out in the absence of a catalyst. In this procedure, the compounds according to the invention can be produced particularly advantageously if the dialkylamine released during the reaction is a relatively volatile compound which can be removed from the reaction mixture by distillation, as a result of which the balance of the reaction is shifted to the side of the compounds according to the invention. However, bis (dialkylamino) dialkylsilanes can also be used advantageously in the presence of an acidic catalyst, for example an aliphatic or aromatic C.₁- to C₂o-carbon or sulfonic acid, an acidic, organic ion exchanger, for example one whose polymer matrix carries carboxyl or sulfonic acid groups, an acidic inorganic compound, for example a zeolite, a bleaching earth, a montmorillonite or acidic aluminum phosphate or in the presence of mineral acids, such as Hydrochloric, sulfuric or phosphoric acid can be reacted with poly-THF to form the poly-THF derivatives according to the invention.

0019Just like bis (dialkylamino) dialkylsilanes, bis (dialkoxy) dialkylsilanes Illb<chemistry id="chem0011" num="0011"><img file="EP0509271A2_D0011.tif" /></chemistry> can be reacted with poly-THF in the presence or absence of an acidic catalyst, practically the same facts apply as set out in the previous section, with the exception that when these starting compounds are used, it is preferred to work in the presence of an acidic catalyst. If the preparation of the compounds according to the invention from the starting compounds of the type Illb or IIIc is carried out in the presence of an acidic catalyst, this is generally added in amounts of 0.001 to 5, preferably in amounts of 0.01 to 1, equivalents / mol of silicon compound Reaction mixture.

0020Dialkyldihydrosilane Illd<chemistry id="chem0012" num="0012"><img file="EP0509271A2_D0012.tif" /></chemistry>are preferably reacted with poly-THF in the presence of a transition metal catalyst, preferably a transition metal catalyst from the 8th subgroup of the periodic table, particularly preferably a transition metal catalyst from the group of platinum metals, these transition metal catalysts generally in the form of their complex compounds, for example in the form of their halogen -, Phosphine or phosphite complexes can be used. Examples of such complexes are hexachloroplatinic acid (H.₂PtC1₆) or the tris (triphenylphosphino) rhodium chloride ((Ph₃P)₃RhCI) called.

0021These catalysts are usually used in amounts of 10-⁸ until 10^-1, preferably from 10-⁷ until 10-² mol per mol of the silylene compounds in question Illd.

0022The poly-THF II is reacted in a molar ratio of poly-THF II: silicon compound III of 1: 1 to 2: 1. The chain length of the poly-THF derivative formed can be controlled by adjusting this molar ratio. For example, when a poly-THF / dichlorodimethylsilane ratio of 2: 1 is set, a compound I is obtained which contains two poly-THF units linked via a siloxi bridge, whereas a polymer is formed at a molar ratio of 7: 6 there is an average of more than 4 poly-THF units linked via a siloxi bridge.

0023The reaction of the silylene compounds III with poly-THF can be carried out in the presence or in the absence of solvents which are inert under the reaction conditions, such as diethyl ether, methyl tert-butyl ether (MTBE), tetrahydrofuran, dioxane, dimethylformamide, toluene, dichloromethane or chloroform . The presence of solvents can be particularly advantageous if the reaction mixture is to be filtered after the reaction has ended, for example in order to separate heterogeneous catalysts or to separate salts which have precipitated out during the reaction.

0024The process for the preparation of the poly-THF derivatives according to the invention can be carried out batchwise in conventional reactors, such as stirred tanks, or continuously, for example with the aid of stirred tank cascades or in tubular reactors. If heterogeneous catalysts, such as solid ion exchange resins or montmorillonites, are used, their arrangement in a fixed bed reactor is preferred, and this can be operated in the bottom or trickle mode. As a rule, a reaction temperature of 0 to 200 ° C., preferably 10 to 170 ° C. and particularly preferably 20 to 150 ° C. is used in the process according to the invention. The reaction is expediently carried out at atmospheric pressure or under the autogenous pressure of the reaction system; the use of higher pressures is also possible.

0025The poly-THF derivatives according to the invention are liquid at room temperature and are distinguished by a relatively low, kinematic viscosity even at high average molecular weights. For example, the kinematic viscosity of a siloxi-poly-THF based on poly-THF 250 with an average molecular weight of 1240 daltons at 20 ° C. is 971.4 mPa 's (measured using an Ubbelohde viscometer), whereas poly-THF 1000 at this temperature is present as a solid and generally has to be melted before use. However, this leads to an increased outlay on equipment in the production of polyurethane moldings, in particular when using the technique of reaction injection molding (RIM); (Lit .: Christopher W. Macosko: RIM-Fundamentals of Reaction Injection Molding, Hanser Publishers, New York, 1989). In contrast to conventional polytetrahydrofurans, the poly-THF derivatives according to the invention are easier to handle, especially in such applications.

0026The present invention further relates to polyurethanes which contain the poly-THF derivatives according to the invention as a diol component.

0027Polyurethanes are understood to mean polyadducts which result from the reaction of multifunctional isocyanates, for example di- or triisocyanates, with polyhydric alcohols. Practically all aliphatic, alicyclic and aromatic di-, tri- and polyisocyanates, such as 1,6-diisocyanatohexane, isophorone diisocyanate, trimeric isophorone diisocyanate and / or trimeric hexane, can be used as isocyanate building blocks for the production of the polyurethanes according to the invention. diisocyanate, diisocyanatotoluene, diisocyanatonaphthalene, 4,4'-diisocyanatodiphenylmethane and its positional isomers, urethanized 4,4'-diisocyanatodiphenylmethane, Polyphenyl-polymethylene polyisocyanates, isocyanate group-containing adducts of toluene diisocyanate and trimethylolpropane and / or toluene diisocyanate trimer can be used.

0028In addition to the poly-THF derivatives according to the invention, all of the diols, triols and / or polyols normally used for the production of polyurethanes can be used as alcohol building blocks for the production of the polyurethanes according to the invention. Examples of such polyhydric alcohols are low molecular weight polyols such as ethylene glycol, glycerol, 1,2-propylene glycol, trimethylolpropane, pentaerythritol, sugar alcohols, sugar and / or starch, polyether polyols such as polyoxyethylene, polyoxypropylene, polyoxyethylene polyoxypropylene mixing and / or Block polymers, polytetrahydrofurans, halogenated polyether polyols, polyester polyols, for example those based on terephthalic acid, phthalic acid, Isophthalic acid, hexahydrophthalic acid, succinic acid and / or adipic acid base with, for example, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentylglycol, thiodiglycol, hydroxypivalic acid, hydroxypivalic acid neopentylglycol ester, glycerol, or trimethylol propane and Alcohol component and polycarbonate polyols, which are obtainable, for example, by transesterifying dialkyl or diaryl carbonates with diols and triols. Of course, the analogous thiols can also be used instead of the diols.

0029Diamines whose use in the manufacture of polyurethanes leads to so-called hybrid systems in which polyurethane units are connected to one another via urea bridges can serve as further building blocks for the production of the polyurethanes according to the invention. Examples of such diamines are diethyltoluenediamine, 4,4'-diamino-3,3'-dichlorodiphenylmethane, isobutyl 3,5-diamino-4-chlorobenzoate, methyl methylene-bis-anthranilate, ethylenediamine, 1-amino-3 -aminomethyl-3,5,5-trimethylcyclohexane (isophoronediamine), hexamethylenediamine and / or hydrazine.

0030Furthermore, practically all types of foam stabilizers, hydrolysis stabilizers, oxidation stabilizers, UV stabilizers and additives, such as blowing agents, flame retardants, dyes, fillers and reinforcing agents, in particular glass fibers, can be admixed in the production of the polyurethanes according to the invention.

0031The polyurethanes according to the invention can be produced using the catalysts or catalyst systems usually used for the production of polyurethanes. Both Lewis bases and Lewis acids or mixtures of these catalysts can be used for this. Examples of suitable Lewis bases are diazabicyclooctane, dimethylbenzylamine, bis-dimethylaminomethyl ether, tetramethylguanidine and bis-dimethylaminomethylphenol. Lewis acids which can advantageously be used are, for example, tin diethylhexoate, dibutyltin dilaurate, dibutyltin bisdodecyl mercaptide and lead phenylethyldithiocarbaminate.

0032The polyurethanes according to the invention can be produced by the conventional methods of polyurethane production, for example by mixing the reactive components together. This can be done, for example, using the RIM method using high-pressure or low-pressure mixing.

0033The polyurethanes according to the invention can contain the poly-THF derivatives according to the invention in proportions of 5 to 80, preferably 5 to 20 and particularly preferably 5 to 10% by weight, based on the polyol component contained therein.

0034The polyurethanes according to the invention have the same advantages over conventional polyurethanes in that they have the same and equivalent properties, since existing polyurethane moldings can be removed much more easily from the metal molds of the injection molding machines, which is why the use of additional release agents, such as silicone oils or waxes, is completely dispensed with or at least restricted in their use can be. This leads to a considerable simplification of the process for the production of molded polyurethane bodies, since an additional work step, namely the repeated coating of the injection molds with release agent, can be saved. Furthermore, when using the polymers according to the invention, the addition of internal release agents, ie of additives which are added to improve the separability of the polyurethane moldings from the injection mold of the polyurethane reaction mass. This is equivalent to an improvement in the product properties of the polyurethane molded articles, since such additives generally diffuse over time from the polyurethane molded article on its surface, which is generally undesirable.

0035Examples:<ul id="ul0001" list-style="none"><li>The average molecular weight MG was determined osmometrically in the poly-THF derivatives according to the invention.</li></ul>

0036The OH number of the poly-THF derivatives according to the invention was determined by the acetylation of these compounds with the pyridine / acetic anhydride / diazabicyclooctane system and the subsequent titration of the excess acetic anhydride used by means of an aqueous alkali metal hydroxide solution. The dimension of the OH number is mg KOH / g substance.

0037The silicon content of the poly-THF derivatives according to the invention was determined by atomic emission spectrometry after their wet ashing with concentrated sulfuric acid and the sodium carbonate / borax digestion of the silicas formed.

0038All reactions for the preparation of the siloxi-polytetrahydrofurans were carried out in an inert gas atmosphere.

Example 1:

0039Preparation of bis-poly-THF-dimethylsiloxane from poly-THF 250 and dimethyldichlorosilane.

004058.0 g of poly-THF 250 (0.25 mol) in 150 ml of MTBE and 27.8 g (0.275 mol) of triethylamine were placed in a 500 ml stirred flask.

004116.13 g (0.125 mol) of dimethyldichlorosilane in 100 ml of MTBE were added dropwise to this solution over the course of 1.5 h, with constant stirring and at an internal temperature of 25 to 28 ° C. After the addition had ended, the mixture was stirred at 50 ° C. for a further 2 h and the reaction solution was filtered to remove precipitated triethylammonium salts. After the solvent was distilled off, the desired product was obtained in the form of a light oil.

0042Analyzes:<ul id="ul0002" list-style="none"><li>Si content: 5.9% by weight</li><li>OH number: 252</li><li>MG: 444</li><li>CI content: &lt;0.5% by weight</li></ul>

Example 2:

0043Preparation of bis-poly-THF-dimethylsiloxane from poly-THF 1000 and dimethyldichlorosilane

0044250.0 g of poly-THF 1000 (0.25 mol) were reacted analogously to Example 1. THF served as solvent.

0045Analyzes:<ul id="ul0003" list-style="none"><li>Si content: 1.2% by weight</li><li>OH number: 56</li><li>MG: 2000</li><li>CI content: &lt;0.5% by weight</li></ul>

Example 3:

0046Preparation of bis-poly-THF-methylvinylsilane from poly-THF 250 and methylvinyldichlorosilane

0047The procedure was as in Example 1 and instead of the dimethylchlorosilane, 17.63 g (0.125 mol) of methylvinyldichlorosilane were reacted.

0048Analyzes:<ul id="ul0004" list-style="none"><li>Si content: 4.7% by weight</li><li>OH number: 175</li><li>MG: 640</li><li>CI content: &lt;0.5% by weight</li></ul>

0049¹Nuclear Magnetic Resonance Spectrum (NMR) (CDCl₃): <ul id="ul0005" list-style="none"><li>δ 6.0 (m, vinyl-H); 3.7 (t, Si-O-CH₂); 3.65 (m, HO-CH₂); 3.4 (m, polyether); 2.8 (s, OH); 1.6 (m, polyether); 0.2 (s, CH₃Si)</li></ul>

Example 4:

0050Preparation of bis-poly-THF-methylphenylsilane from poly-THF 250 and methylphenyldichlorosilane

0051The procedure was as in Example 1 and 23.9 g (0.125 mol) of methylphenyldichlorosilane were used.

0052Analyzes:<ul id="ul0006" list-style="none"><li>Si content: 4.2% by weight</li><li>OH number: 162</li><li>MG: 690</li><li>CI content: &lt;0.5% by weight</li></ul>

Example 5:

0053Preparation of polysiloxi-polytetrahydrofuran from poly-THF 250 and dimethyldichlorosilane (molar ratio 4: 3)

005458.0 g (0.25 mol) of poly-THF 250 in 250 ml of MTBE and 27.8 g (0.275 mol) of triethylamine were placed in the apparatus of Example 1. At an internal temperature of 25 to 28 ° C., 24.5 g (0.19 mol) of dimethyldichlorosilane were added dropwise over the course of 1.5 hours and then stirring was continued at 50 ° C. for 2 hours. The solvent was distilled off and the product obtained as a light oil.

0055Analyzes:<ul id="ul0007" list-style="none"><li>Si content: 6.5% by weight</li><li>OH number: 173</li><li>MG: 650</li><li>CI content: &lt;0.5% by weight</li></ul>

Example 6:

0056Preparation of polysiloxi-poly-tetrahydrofuran from poly-THF 250 and dimethyldichlorosilane (molar ratio 7: 6)

00574.5 kg of poly-THF 250 (19.332 mol), 3.7 kg (36.535 mol) of triethylamine and 15 l of MTBE were placed in a 50 l enamel stirred kettle. 2.14 kg (16.589 mol) of dimethyldichlorosilane dissolved in 2 l of MTBE were added to the reaction mixture over the course of 3 hours with stirring at an internal temperature of from 18 to 28 ° C. Another 3 l of MTBE were added and the reaction mixture was stirred at 50 ° C. for a further 2 h. The precipitated ammonium salts were filtered off on a suction filter and the solvent was distilled off from the filtrate. 5.4 kg of a yellow oil were obtained.

0058Analyzes:<ul id="ul0008" list-style="none"><li>Si content: 7.4% by weight</li><li>OH number: 106</li><li>MG: 1240</li><li>CI content: 0.5% by weight</li><li>¹H-NMR (CDCl₃):</li><li>δ (ppm): 3.7 (m, Si-O-CH₂); 3.65 (m, HO-CH₂); 3.4 (m, polyether); 2.6 (s, OH); 1.6 (m, polyether); 0.2 (-</li></ul>

0059(CH₃)₂Sl)

Example 7:

0060Polysiloxi-polytetrahydrofuran with a molecular weight of 5300

0061500 g (0.5 mol) of poly-THF 1000, 500 ml of MTBE and 95.4 g (0.943 mol) of triethylamine were placed in a 2 l stirrer. 55.3 g of dimethyldichlorosilane (0.429 mol) were added dropwise to this mixture over a period of 5 h and at a temperature of 25 to 30 ° C., and a further 700 ml of MTBE were then added. When the addition was complete, the mixture was stirred for a further 3 h and the ammonium salts which had precipitated out were filtered off. The solvent was distilled off from the filtrates. 533.8 g (100% yield) of a colorless oil were obtained, which was still liquid even after four weeks of storage at room temperature.

0062Analyzes:<ul id="ul0009" list-style="none"><li>Si content: 2.1% by weight</li><li>OH number: 25</li><li>MG: 5300</li></ul>

Example 8:

0063Production of polysiloxi-polytetrahydrofuran from poly-THF 650 and dimethyl-bis- (dimethylamino) silane

006465.0 g of poly-THF 650 (0.1 mol), 9.7 g of dimethyl-bis- (dimethylamino) silane (0.067 mol) and 50 ml of chlorobenzene were mixed together in a 250 ml stirrer and heated under reflux for 5 h . Dimethylamine escaped. When the reaction had ended, the chlorobenzene solvent was distilled off, leaving 68.3 g (100% yield) of a slightly yellowish oil.

0065Analyzes:<ul id="ul0010" list-style="none"><li>Si content: 2.7% by weight</li><li>OH number: 54</li><li>MG: 2000</li></ul>

Example 9:

0066Production of polysiloxi-polytetrahydrofuran from poly-THF 650 and dimethyldihydrosilane

006765.0 g of poly-THF 650 (0.1 mol), 4.0 g (0.067 mol) of dimethyldihydrosilane, 100 ml of THF and 10 mg of H were placed in a 250 ml stirring apparatus₂PtCl₆ • 6H20 (hexachloroplatinic acid) mixed in 0.5 ml butanol and heated to 50 ° C. Hydrogen evolution occurred under these conditions. When the evolution of hydrogen had ended, the reaction was stopped and the solvent was distilled off. 68.0 g (100% yield) of a light oil were obtained.

0068Analyzes:<ul id="ul0011" list-style="none"><li>Si content: 2.6% by weight</li><li>OH number: 58</li><li>MG: 1950</li></ul>

Example 10:

0069Production of polysiloxi-polytetrahydrofuran from polytetrahydrofuran 1000 and dimethyl-bis-methoxysilane

0070500 g (0.5 mol) of poly-THF 1000, 500 ml of toluene, 5.0 g of pivalic acid and 51.5 g (0.429 mol) of dimethyl-bis-methoxysilane were heated under reflux in a 2 l stirring apparatus for 5 h and then the solvent toluene and the newly formed methanol are distilled off. The residue was redissolved in 500 ml of toluene and extracted with 500 ml of aqueous 10% by weight sodium hydrogen carbonate solution to remove the remaining carboxylic acid. The organic phase was freed from water and the solvent was distilled off. 510.9 g (97.5% yield) of a colorless oil were obtained, which was still liquid even after storage for twelve weeks at room temperature.

0071Analyzes:<ul id="ul0012" list-style="none"><li>Si content: 2.2% by weight</li><li>OH number: 23</li><li>MG: 5000</li></ul>

Example 11:

0072Production of a polyurethane according to the invention

0073To produce polyurethanes according to the invention, components A and B were mixed with one another in a mixing ratio (w / w) of 100 (A): 39.7 (B) and pressed into injection molds immediately after they had been mixed.

0074Component A had the composition:<ul id="ul0013" list-style="none"><li>49.7% by weight of Lupranol @ 2042 (block-copolymeric polyether triol with a hydroxyl number of 2.7 on the basis of trimethylolpropane, 1,2-propylene oxide and ethylene oxide)</li><li>14.41% by weight of diethyltoluenediamine (mixture of isomers)</li><li>7.21% by weight of dimethylsiloxi-polytetrahydrofuran based on poly-THF 250; MG 1070 Dalton</li><li>0.72% by weight 30% by weight solution of diazabicyclooctane in propylene glycol</li><li>0.14% by weight dibutyltin dilaurate</li><li>27.9% by weight of ground glass fibers</li></ul>

0075Component B was an isocyanate prepolymer, which had been prepared by the reaction of diphenylmethane diisocyanate with a mixture of polypropylene oxide diol (average molecular weight: 450 daltons) and dipropylene glycol and which had a free isocyanate group content of 23% by weight.

0076The polyurethane test panels produced in this way had the format A4.

0077For comparison, test plates were produced according to a comparison recipe which contained 7.21% by weight of poly-THF 1000 instead of the siloxi-polytetrahydrofuran according to the invention with an otherwise identical composition.

0078Result of the mechanical tests:<ul id="ul0014" list-style="none"><li>During the mechanical test, no differences between the polyurethane panels produced according to the invention and the comparison panels regarding the following properties could be determined: tear resistance, tear propagation resistance, elongation at break, flexural modulus of elasticity.</li></ul>

0079The polyurethane plates according to the invention were, however, much easier to remove from the injection molds than the comparison plates, which is why the use of an additional release agent in the plates according to the invention could be dispensed with.