Polysiloxane dispersions, process for their preparation and use thereof.

The invention relates to a polysiloxane, a process for their preparation and their use as a precursor for the production of silicone-modified thermoplastic, thermosetting or elastomeric plastics.

Combination products of polyorganosiloxanes with organic carbon compounds, such as polyols, polyethers and polyesters, are already known. This is, however, generally to copolymers in which polysiloxane with the organic carbon polymer linked hauptvalenzmäßig. Such products are 317ff in the monograph "Chemistry and Technology of Silicones" by W. Noll, Weinheim / Bergstrasse 1968, pages. described. Further, from DE-A-25 12 632, copolymers of diols and polyols with polyorganosiloxanes known. This gives polysiloxanols proposed for modifying urethane or epoxy resins. It has been shown that in this type of modification homogeneously polysiloxanes that are molecularly dispersed in the polymer, which often adversely affects the mechanical strength and chemical resistance of the resulting plastics.

Further, combinations of polyorganosiloxanes with polyethers or polyesters are known, the disperse systems form in which the polyorganosiloxane component forming the outer phase and the organic carbon component of the disperse phase. Thus, from EP-A-0058340 organic multi-component dispersions which consist of polyorganosiloxane-polyether-polyester graft copolymer as a disperse phase and polyorganosiloxanes as the outer phase. It is accordingly modified polyorganosiloxanes and not to polyorganosiloxane-modified polyether or polyester.

In EP-A-0304946 an additive material from finely divided silicone rubber will be described with a particle diameter of 1 mm or less by dispersing a curable silicone rubber composition comprising a specific silane or its partial hydrolysis products, in free form or chemically bound to the silicone rubber, in water will be produced. The silane has a terminally unsaturated alkenyl radical, optionally having a functional group such as epoxy, amino, acryloxy, methacryloxy group or mercapto group. This additional material should be added to improve the physical properties of organic resins and synthetic rubbers.

Finally, from DE-A-36 34 084 with elastomeric polyorganosiloxanes suspensions as dispersed phase and reactive resins which can be processed to form thermosets, known as the outer phase, for example, are suitable as precursors for the preparation of thermosetting molding materials, insulating materials and laminates.

The invention has for its object to provide suitable silicon-containing precursors that are highly compatible with various types of plastics, ensure good processability and open multiform applications, so that with their help very different silicone-modified plastics, both thermoplastic and thermoset and elastomer plastics can be prepared having improved physical and chemical properties. Here are desirable properties of silicones such as thermal stability, are retained in the resulting plastics, while undesirable properties of silicones such as low mechanical strength, in the plastics silokonmodifizierten possible not to be present. Simultaneously, the characteristic physical and chemical properties of the plastics are not to be modified as little as possible or be adversely affected.

This object is achieved by a polysiloxane, which is characterized by a content of<ul><li>(A) 25 to 99.9 parts by weight -% of an external phase at temperatures of from 20 to 100 ° C liquid monomeric or polymeric polyols, linear or branched polyglycol ethers, polyesters based on polyols and aliphatic, cycloaliphatic or aromatic dicarboxylic acids, aliphatic polylactones and / or polycarbonates,</li><li>(B) 0.1 to 75 wt .-% of a disperse phase of one or more three-dimensionally cross-linkable polyorganosiloxanes wherein the crosslinked polyorganosiloxane particles have an average diameter from 0.02 to 50 microns, and</li><li>(C) 0 to 20 weight -% of per se known adjuvants, in particular, solvents, plasticizers, Vernetzungsmitteln, catalysts, stabilizers, dispersants, curing agents, Reaktionsvermittlern and / or means for influencing the viscosity of the external phase.</li></ul>

It was surprisingly found that the proposed inventions, specifically composite polysiloxane is very versatile as a precursor, because it has excellent compatibility with many types of plastics and this gives the advantageous properties of silicones, without application of the these plastics are inherent desirable physical and chemical properties are significantly impaired. Thus, with the inventive polysiloxane silikonmodifizierte thermoplastische, thermoset or elastomeric plastics for practice valuable Eigenschaftskombinationen and with very good processability prepared as set forth in detail below is.

The monomeric polyols can be used for the purpose according to the invention a variety of known compounds. Because of the ready availability and advantages, in particular the excellent compatibility and good processability of the resulting products, are used for the external phase of the dispersion according to the invention polyols are linear and branched aliphatic glycols preferably used, wherein the external phase of the polysiloxane dispersion particularly preferably Ethylenglykol, 1.2 - or 1,3-propanediol, 1,2- or 1,4-butanediol, 1,6-hexanediol, 2,2,4-trimethylpentanediol-1,3 and / or neopentyl glycol having.

Furthermore, as aliphatic polyols, preferably glycerol, trimethylol propane, and sugar alcohols, particularly erythritol, xylitol, mannitol and / or sorbitol, are used. Further, the external phase may be used as preferred polyols, one or more alicyclic polyols, in particular 1,4-cyclohexane dimethanol, and / or sucrose.

Suitable polymeric polyols for the outer phase is preferably those having an average molecular weight from 200 to 20,000 in question, wherein the polymeric polyol such on the basis of (meth) is preferably Acrylsäurealkylenglykolestern. The outer phase of the dispersion according to the invention may further comprise preferably polymeric polyols which are obtained by hydrolysis or partial hydrolysis of vinyl ester containing polymers.

Suitable polyethers for the external phase, especially the cyclic by ring-opening polymerization ether in the presence of polyols, such as the above-mentioned polyols, available linear or branched polyglycol ether in consideration of which, because of their relatively easy availability, polyethylene glycol, polypropylene glycol and / or polytetramethylene glycol or their copolymers are preferred.

Suitable polyesters are for the external phase of the dispersion of the invention those based on polyols and aliphatic, cycloaliphatic or aromatic dicarboxylic acids, and indeed all the specific liquid at temperatures of 20 to 100 ° C saturated polyester, preferably succinate, glutarate, adipic phthalic acid, isophthalic acid, terephthalic acid and / or esters of the corresponding hydrogenation products, with the alcohol component of monomeric or polymeric polyols, for example those of the aforementioned kind.

Further inventively usable polyesters are aliphatic polylactones, preferably ε-polycaprolactone, and / or polycarbonates, for example with phosgene by polycondensation of diols. A are used with an average molecular weight from 500 to 100,000, preferably for the external phase of the bisphenol Polykohlensäureester.

Instead of the above-mentioned polyols, polyethers and saturated polyester mixtures of the abovementioned substance classes for the external phase of the polysiloxane dispersion according to the invention can be used for the purpose according to the invention. The use of such mixtures may be, for example, with regard to a reduction in the glass temperature or melting point of the resulting products is advantageous.

For the purpose of influencing the viscosity of the external phase, in particular the viscosity reduction or liquefaction, the present invention for the external phase provided polyols, polyethers and saturated polyesters or mixtures thereof suitable excipients, in particular solvents, plasticizers, diluents may optionally etc. yet. are added.

The disperse phase of the polysiloxane dispersion according to the invention is formed of one or more three-dimensionally cross-linkable polyorganosiloxanes wherein the particles dispersed in the outer phase polyorganosiloxane particles after the crosslinking an average diameter in the range of 0.02 to 50 microns, preferably from 0.05 to 10 microns , particularly preferably from 0.07 to 5 microns and most preferably from 0.07 to 1 .mu.m. These polyorganosiloxane particles have on their surface reactive groups through which they can call, chemically bonded to the components of the external phase, namely the monomeric or polymeric polyols, polyglycol and / or polyesters.

Among the variety of different three-dimensionally crosslinkable polyorganosiloxanes such are preferably used which are derived from siloxane units of the general formula - (R₂SiO) - (1) derived, in which both monovalent residues R, which may be identical or different, linear or branched alkyl groups having 1 to 18 carbon atoms, cycloaliphatic groups with 4 to 8 C-atoms, linear or branched alkenyl groups having 2 to 4 C-atoms , phenyl or alkylphenyl groups having 1 to 12 carbon atoms in the aliphatic radical, said hydrocarbon radicals may also be substituted by halogens or hydroxyl, carboxyl, carboxylic anhydride, amino, epoxy, alkoxy or alkenyloxy, polyether or polyolefin group and represent hydrogen, said Grupden are connected directly or via an oxygen or nitrogen atom with a silicon atom of the polysiloxane chain.

Examples of such radicals R are methyl, ethyl, isopropyl, isobutyl, dodecyl and octadecyl groups, cyclopentyl, cyclohexyl and cyclooctyl groups, vinyl, allyl, isopropenyl, and 3-butenyl groups, ethylphenyl, dodecyl, further groups with hydrocarbon radicals, some of which are substituted, for example by halogens, in particular fluorine or chlorine, such as the chloropropyl or the 1,1,1-trifluoropropyl. At least a part of R can also consist of polymeric groups, especially polyethers such as polyethylene, polypropylene, polybutylene or polyhexamethylene glycol or polytetrahydrofuran, and copolymers of these ethers, and also polyolefins such as polybutadiene, polyisoprene, polybutene, polyisobutene u. come like. in question. Finally, a part of the radicals R can also be hydrogen. It is also possible to use mixtures of the aforementioned Polyorganoslloxane.

Further, it is also readily possible, according to the invention to use those polyorganosiloxanes in which different radicals R are present in the polymer molecule. These different groups may be randomly distributed along the siloxane backbone. In a preferred embodiment, the polyorganosiloxane is a block copolymer used in the invention, are arranged in which monovalent residues R 'and R along the siloxane chain in blocks which derive from polymer units of the general formula - (R'₂SiO)_x- (R₂SiO)_y- (2) derive, where the radicals R 'and R having the same meaning as R, are different from each other, while the radicals R' and R amongst themselves may be the same or different, and x and y equal 1 or are integral multiples thereof are ,

Because of the easy availability and good effect such polyorganosiloxanes are preferred in which at least represent 50% of the radicals R, R 'and R are methyl and / or phenyl groups.

The invention further relates to a process for the preparation of Polysiloxandispersionen according to claims 1 to 19, which is characterized in that<ul><li>(A) an emulsion of 0.1 to 75 wt .-% of one or more three-dimensionally cross-linkable, liquid polyorganosiloxanes as disperse phase in 25 to 99.9 weight .-% of an external phase from liquid at temperatures of 20 to 100 ° C monomers or polymeric polyols, linear or branched polyglycol ethers, polyesters based on polyols and aliphatic, cycloaliphatic or aromatic dicarboxylic acids, aliphatic polylactones and / or polycarbonates with 0 to 20 wt .-% of per se known auxiliary substances, in particular solvents, softeners, cross-linking agents , catalysts, stabilizers, dispersants, curing agents, reaction mediators and / or agents is made to influence the viscosity of the external phase in which the polyorganosiloxane droplets are present with a mean diameter in the range of 0.02 to 50 microns, and </li><li>(B) is carried out a cross-linking in the polyorganosiloxane in a conventional manner to form solid particles.</li></ul>

Preferably, in the process stage (a) 2 to 50 wt .-% of one or more three-dimensionally cross-linkable liquid polyorganosiloxanes.

The average molecular weight of the usable in the process of the invention liquid cross-linkable polyorganosiloxanes can vary within wide limits and is generally in the range from 800 to 500 000. The lower limit is determined by the molecular weight decreases, the crosslink density of the polyorganosiloxane is larger and thereby the elasticity decreases , This effect, however, can be mitigated by adding bifunctional crosslinking agents in certain limits. The upper limit is given by the increasing viscosity with increasing molecular weight of the polyorganosiloxanes, which complicates the desired fine distribution of the liquid in the outer phase. Therefore, in step (a) are preferably used such cross-linkable polyorganosiloxanes or polyorganosiloxane having an average molecular weight from 1000 to 100,000, particularly preferably 1,200 to 30,000.

In the inventive dispersion, the particle size of the crosslinked polyorganosiloxanes may vary depending on the objectives pursued by the modification of properties over a wide range. Since with increasing average particle size, the effectiveness of the polyorganosiloxane modification is dwindling, is of economic reasons, a mean particle diameter of no more than 50 microns expedient. Andererseits both the processability and the Langzeitstabilität the inventive dispersions with particle size abnehmender unfavorable, so that it is not as sinnvoll proven, has the average particle diameter of less than 0.02 microns adjust. Accordingly, the crosslinkable liquid polyorganosiloxanes in the outer phase are dispersed by the inventive process that the formed polysiloxane particles have an average diameter ranging from 0.02 to 50 .mu.m, preferably in the range of 0.05 to 10 .mu.m, more preferred range of 0.07 to 5 microns and more particularly preferably in the range of 0.07 to 1 micron.

The particle size is not critical usually and can include, for example the preferred or particularly preferred range completely or only partially. In many cases it may be useful to set certain properties to choose a more or less narrow particle size distribution. To achieve special effects also a bi- or tri-modal distribution may be applied.

The concentration of the cross-linkable polyorganosiloxanes in the dispersion of the invention depends largely on the type of the intended effect, and with the modification of the particle size of the polyorganosiloxanes. Thus, possibly already relatively low amounts of the crosslinkable polysiloxanes down to 0.1 wt -% in the dispersions of the invention be sufficient, while the upper limit by the stability of the dispersion and the maximum Raumerfüllung the external phase is added and, depending on the density , at most 75 wt .-% is.

The inventive method can be carried out in various embodiments. A preferred embodiment is that the liquid cross-linkable polyorganosiloxanes are initially dispersed in a first liquid medium which is mixable with the actual outer phase and that subsequently the resulting dispersion is added to the actual outer phase and blended with it, wherein the cross-linking the polyorganosiloxanes before, during or after the mixing with the actual outer phase in a suitable manner and, if appropriate, the first dispersion medium after completion of the mixing is completely or partially removed.

First dispersing come here only those liquids in question, whose presence in the final product desired or zumindest not disturbing is, such as relatively low-boiling solvents, plasticizers or Relativverdünner, but preferably water.

In another, likewise preferred embodiment of the method according to the invention the cross-linkable liquid polyorganosiloxanes are initially dispersed in a first liquid medium which is immiscible with the actual outer phase, whereupon the resulting dispersion mixed with the actual outer phase and then the first dispersion medium in a suitable way is completely or partially removed, and the crosslinking before the polyorganosiloxanes is performed during or after the mixing with the actual outer phase or separating the first medium.

First dispersing come in this embodiment of the process such liquids in question, which can be removed after mixing with the invention to be modified polyols, polyethers and polyesters and mixtures thereof, without adversely affecting the desired properties of the image appropriately again, for example by distillation. low boiling point solvent and preferably water are suitable for this purpose.

The distribution of the liquid polyorganosiloxanes in the outer phase may be effected with well-known for the preparation of emulsions per se measures and auxiliaries, for example in that, if appropriate, presents one of the two phases, together with a suitable stabilizer and the other phase supplies. The emulsification is carried out with the aid of mechanical units which exert a sufficiently high shear to be dispersed in the medium, such as stirrers, mixers, kneaders, dissolvers, high-pressure or ultrasonic homogenizers, etc.. It is also possible to first prepare a crude preemulsion of the polyorganosiloxanes, which is then subsequently, in a homogenizer or Feinemulgierschritt with, for example one of the above-mentioned units to an emulsion with the desired Tröpfchengrößenverteilung weiterverarbeitet is.

If the substance to be emulsified polyorganosiloxanes having no self-emulsifying properties, it is necessary, certain dispersive agent to. A self-emulsification does not occur usually when the organo the polyorganosiloxanes methyl, ethyl, vinyl or phenyl groups. On the other hand can be expected of a self-emulsification, if at least a part of the polyorganosiloxanes used in the invention are the organo longer chain polyether, polyester or aliphatic hydrocarbon radicals.

The stabilizers which are known for the production of silicone emulsions to be anionic, cationic or non-ionic emulsifiers and surfactants can be used. Your choice depends naturally on the external phase in which the polyorganosiloxanes are emulsified sol len and can be made by an expert after a few preliminary experiments. In order to obtain particularly stable emulsions, combinations of various stabilizers may be used.

As already mentioned above, exerts the average particle size or the particle size of the polyorganosiloxane particles of a significant influence on the effectiveness of the polyorganosiloxane modifier and processability and long-term stability of the dispersions of the invention. It is therefore important that particle size and particle size distribution can be controlled in the dispersions of the invention in the desired and necessary way. This can be done in a known manner for example by selection and concentration of the stabilizers. To the desired feinteiligen emulsions to obtain, will be particularly effective emulsifiers at higher concentrations, for example in an amount of 20 to 100 weight -%, based on the amount of the polyorganosiloxane used. A further possibility for controlling the particle size or the particle size distribution is that when the emulsifying aufgewendete mechanical energy varies, as is well known, the average particle size decreases with increasing emulsifying energy. therefore advantageous for the purposes of the invention particle sizes and particle size of the polyorganosiloxane particles can be adjusted by targeted variation of the emulsification conditions and / or the selection and concentration of the stabilizers. If one wishes for specific effects a di-, tri- or multi-modal particle size distribution have, so it can be adjusted, for example by mixing different unimodal distributed emulsions or suspensions.

The temperature at which the Emul held government is not critical and will depend generally on the viscosity of the polyols used, polyether and polyester or mixtures thereof. If possible, we will also carry out the emulsification operation for reasons of energy conservation at room temperature or a little, but it may also be that at high viscosities of the outer phase used emulsification at higher temperatures, eg up to 150 ° C, must be carried out.

After the emulsification durchgeführt been is done in Verfahrensstufe (b) of the inventive method, the cross-linking in the polyorganosiloxane droplets in a conventional manner to form solid particles.

In what way or the mechanism by which the liquid polyorganosiloxanes are cross-linked, is not critical as long as it is ensured that the fine distribution of the polysiloxane is not significantly disturbed by the crosslinking reaction and that held no or only insignificant crosslinking reactions in the outer phase. Under this condition, the expert has a large number of different networking opportunities polyorganosiloxanes available, such as are to be found in the already cited monograph "Chemistry and Technology of Silicones".

In a preferred embodiment of the inventive method, the liquid cross-linkable polyorganosiloxanes are initially admixed with crosslinking agents and / or catalysts and then emulsified in the outer phase, wherein the conditions are chosen so that the transition of the polysiloxane particles from the liquid to the solid state until performed after the end of Emulgiervorganges.

In another, likewise preferred embodiment of the method according to the invention suitable crosslinking agents and / or catalysts may be added only after formation of the organopolysiloxane emulsion, by which the cross-linking of the liquid polyorganosiloxane particles is effected.

The crosslinking of the polysiloxane droplets into solid particles can be carried out in particular by per se known addition and condensation process. Are those used as cross-linkable liquid polyorganosiloxanes which crosslink after the addition mechanism, then are used as crosslinkers generally polyorganohydrogensiloxanes containing a sufficient number of Si-H bonds, such as polymethylhydrogensiloxane, and as catalysts noble metals of the VIII. Subgroup of the Periodic Table of the elements and their compounds added. Addition crosslinking usually takes place at elevated temperatures, eg between 60 and 140 ° C, in the presence of a noble metal catalyst.

If such used as cross-linkable liquid polyorganosiloxanes which crosslink after the condensation mechanism, so can be used with hydrolyzable SiO or SiN bonds as crosslinking as silanes. Such crosslinkers are eg Methyltriacetoxysilane, methyltrimethoxysilane, tetraethoxysilane, methyl-tris (butanonoximino) silane, methyl tris (cyclohexylamino) silane, etc.. However, compounds containing as Crosslinkers hydrolyzable groups of other elements, such as tetrabutyl titanate, or Si-H bond-containing polyorganohydrogensiloxanes be used. As catalysts, if necessary, the known polyorganosiloxanes for condensation of heavy metal compounds, for example tin (II) octoate or dibutyltin dilaurate, may be used.

The date on which the cross-linking of the liquid polyorganosiloxane droplets stattfindet, is not critical and can be controlled so that the cross-linking to the desired time arrives, beispielsweise immediately after the emulsification or even a long time after that, as a few months later. This also applies to the above-mentioned preferred embodiments of the method according to the invention.

As already mentioned, the cross-linking of the liquid cross-linkable polyorganosiloxanes usually by the addition of crosslinking agents and / or catalysts is effected. If the crosslinking agents and / or catalysts added before emulsification, the selection of which must of course be such that the crosslinking reaction does not take place even under the conditions prevailing during the emulsification conditions, which would possibly hinder the emulsion process, but essentially only after the emulsification, ie, at a later, predetermined time, takes place.

The crosslinking time, ie the time within the network the polysiloxane particles virtually completely, can be adjusted by the person skilled in the known measures. Thus, the crosslinking time at condensation crosslinks eg through the selection and concentration of the catalyst, in addition crosslinks eg by adding a temporary acting inhibitor, for example, a short-chain alkynol be set. By appropriate selection of the crosslinking agent and / or catalyst, the cure time can be very large at room temperature, up to a few days or weeks, for example. In such cases it is possible, already some time before the emulsification with the crosslinking agents and / or catalysts to mix the liquid cross-linkable polyorganosiloxanes. The crosslinking is triggered at the desired time by an increase in temperature during or after emulsification.

The Polysiloxandispersionen invention are very well suited for the production of silicone-modified polyurethanes, Polyharn materials, saturated polyesters and polycarbonates. They give these polymers have excellent physical and chemical properties, in particular a significantly improved thermal stability, a very low Glastemperatur (down to -100 ° C), a high Abriebfestigkeit, a very good Witterungsbeständigkeit, very low surface tension and good electrical properties. In addition, the damping properties of the modified polymers are substantially improved. Accordingly, the invention can be used as precursors Polysiloxandispersionen advantageous for the production of silicone-modified thermoplastic, thermosetting or elastomeric plastics based on polyurethanes, polyureas, saturated polyesters and polycarbonates using, for example, molded articles, films, coatings, potting compounds, etc.. The processing characteristics of the polymers obtained are significantly improved in many cases.

The invention is further illustrated by the following examples, without its scope is to be characterized in any way. All parts and percentages given are by weight unless otherwise indicated.

example 1

100 parts of a commercially available polypropylene glycol having a molecular weight of about 2000 were mixed at room temperature with 5 parts of a stabilizer in a known manner by hydrosilylation of 70% of a trimethylsilyl-terminated co-Äquilibrates from cyclic dimethyl and methyl hydrogen siloxanes and 30% of an allyl alcohol prepared as the starting molecule polypropylene glycol was obtained.

To this mixture with stirring at a speed of 500 min⁻¹ within 1hr. 20 parts of a mixture of 80% of a hydroxyl-terminated polydimethylsiloxane having a viscosity of 2000 mPa.s and 20% of a trimethylsilyl-terminated polymethylphenylsiloxane having a viscosity of 800 mPa.s allowed to run. It formed a white emulsion of polyorganosiloxanes in Polyethers with 1 part of methyl tris (butanonoximino) silane and 0.01 parts of dibutyl tin dilaurate and the total mixture was stirred again for 5 min.. The examination in a light microscope showed that the resulting dispersion containing crosslinked polyorganosiloxane particles having a diameter of 0.5 to 3 microns.

example 2

100 parts of ethanol were mixed with 10 parts of a stabilizer, which was composed in the same way as in Example 1 except that a polyethylene glycol was used instead of polypropylene glycol. To the resultant, heated to 50 ° C mixture was added with a viscosity of 5000 mPa.s with stirring 60 parts of a dimethylvinyl-terminated polydimethylsiloxane. Subsequently, the mixture was treated for 5 min. Using an Ultra-Turrax homogenizer. The white emulsion was mixed with 1 part of polymethyl having a viscosity of 60 mPa.s and 0.6 parts of a 1% solution of hexachloroplatinic acid in ethanol and an additional 5 min. Stirring. After about 2 hrs. The polydimethylsiloxane particles were crosslinked. The resulting suspension was then mixed with 1000 parts of 1,2-propylene glycol.

example 3

A mixture of 50 parts of neopentyl glycol, 25 parts of trimethylolpropane and 25 parts of a Polytetramethylengly kolethers (molecular weight 1000) was mixed with 25 parts of the stabilizer from Example 1 and heated with stirring to 70 ° C. Then, 50 parts of a mixture were from 90% hydroxyl endcapped polydimethylsiloxane having a viscosity of 4000 mPa.s and 10% γ-aminopropyltriethoxysilane added to the previous mixture and the total mixture is treated with a Ultra-Turrax homogenizer for 5 min.. The emulsion thus obtained was mixed with 1 part of tetraethoxysilane and the mixture stirred 1 hr. Long. 10 parts of the resulting suspension were mixed with 60 parts of polypropylene glycol (molecular weight 2000) and 20 parts of 4,4'-diphenylmethane diisocyanate, whereupon an exothermic reaction took place and the mixture cured to form a polyurethane elastomer.

A fracture surface of the elastomers obtained was examined after gold coating, the scanning electron microscope and a particle size distribution of the crosslinked polydimethylsiloxane particles observed, which was 0.07 to 0.5 microns. The surface of the polyurethane elastomer was considerably smoother than that of a similar polyurethane without addition of crosslinked polydimethylsiloxane.

example 4

100 parts of demineralized water were mixed with 10 parts of a Alkylpolyethylenglykolethers with 12 EO groups and a C₁₂ - mixed to C₁₈ alkyl group in the molecule. To this mixture, with stirring, 60 parts of a mixture of 96% hydroxyl endcapped polydimethylsiloxane having a viscosity of 2000 mPa.s, 3.9% methyltriethoxysilane and 0.1% dibutyltin dilaurate added over a period of 20 min.. The resulting mixture was treated for 5 min. With an Ultra-Turrax homogenizer and the emulsion thus obtained is maintained at a temperature of 70 ° C for 2 h. Long.

10 parts of this suspension were mixed with 100 parts of a polyester of adipic acid and ethylene glycol having an average molecular weight of 2000 and an OH number of 55 at a temperature of 80 ° C and the water removed by vacuum distillation. In the resulting suspension of polydimethylsiloxane particles in the polyester, the particle size was determined by light microscopy with a particle size in the range of 0.5 to 1 micron.

example 5

a) 100 parts of a commercial polypropylene glycol, which had been prepared with trimethylolpropane as the starting molecule and an OH equivalent weight of 140 had been mixed with 50 parts of a stabilizer, which corresponded to the set forth in Example 1 with the difference that instead of polypropylene glycol, a mixture of 60 parts of polypropylene glycol and 40 parts of polyethylene glycol were used. To this mixture was then heated with stirring from 150 parts of a mixture 96% of a hydroxyl-terminated polydimethylsiloxane having a viscosity of 2000 mPa.s and 4% methyltriethoxysilane added to and treated with an Ultra-Turrax homogenizer. To the obtained emulsion, 0.2 parts of dibutyltin dilaurate were added, whereupon it formed by crosslinking of the polysiloxane, a dispersion of polyorganosiloxane elastomers in the polypropylene glycol.

b) mixing the dispersion obtained under a) with varying amounts of a polypropylene glycol (molecular weight 2000), and the respective stoichiometric amount of diphenylmethane diisocyanate (MDI) according to the invention modified polyurethane (PU) elastomers were prepared with different contents of polysiloxane and measured the properties listed below , For comparison dieselben measurements also to a pure polyorganosiloxane elastomers (ie 100% polysiloxane) having the same composition had as described in Example 5 a) specified, as well as a pure PU elastomers (ie polysiloxane content 0%), the place of the polysiloxane elastomers, a polypropylene glycol (molecular weight 4000) was performed.

b₁) Measurement of tensile strength with a tensile tester according to DIN 53504th

The results are shown in Table 1 and show that a significant improvement in the tensile strength of the non-modified polyurethane can be achieved by the modification according to the invention, although the strength of the pure polysiloxane elastomers is much worse. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="4" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Sample no.</entry><entry namest="col2" nameend="col2" align="center">Polysiloxane content (%)</entry><entry namest="col3" nameend="col3" align="center">Tensile strength (MPa)</entry><entry namest="col4" nameend="col4" align="center">Elongation at break (%)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">1</entry><entry namest="col2" nameend="col2" align="right">0</entry><entry namest="col3" nameend="col3" align="char" char=",">2.4</entry><entry namest="col4" nameend="col4" align="right">290</entry></row><row><entry namest="col1" nameend="col1" align="right">2</entry><entry namest="col2" nameend="col2" align="right">14</entry><entry namest="col3" nameend="col3" align="char" char=",">3.7</entry><entry namest="col4" nameend="col4" align="right">330</entry></row><row><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="right">27</entry><entry namest="col3" nameend="col3" align="char" char=",">5.2</entry><entry namest="col4" nameend="col4" align="right">370</entry></row><row><entry namest="col1" nameend="col1" align="right">4</entry><entry namest="col2" nameend="col2" align="right">38</entry><entry namest="col3" nameend="col3" align="char" char=",">8.7</entry><entry namest="col4" nameend="col4" align="right">370</entry></row><row><entry namest="col1" nameend="col1" align="right">5</entry><entry namest="col2" nameend="col2" align="right">100</entry><entry namest="col3" nameend="col3" align="char" char=",">0.5</entry><entry namest="col4" nameend="col4" align="right">230</entry></row></tbody></tgroup></table></tables>

b₂) determining the mechanical damping by measuring the stress to uniaxial tensile deformation.

A simple but meaningful method for determining the mechanical damping of an elastomer is to determine the stress at constant deformation. The measurements were performed on the same samples 1-5 (see Example 5, b₁)) is carried out in such a manner that after applying a uniaxial tensile deformation of 100% occurred voltage drop 30 sec was determined.. The measurement results are summarized in Table 2 and show a substantial increase in the stress (expressed in% of the value immediately after deformation) against the two unmodified elastomer (Samples 1 and 5).<tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="3" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Sample no.</entry><entry namest="col2" nameend="col2" align="center">Polysiloxane content (%)</entry><entry namest="col3" nameend="col3" align="center">Stress relaxation (%) bez. on initial</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">1</entry><entry namest="col2" nameend="col2" align="right">0</entry><entry namest="col3" nameend="col3" align="right">5</entry></row><row><entry namest="col1" nameend="col1" align="right">2</entry><entry namest="col2" nameend="col2" align="right">14</entry><entry namest="col3" nameend="col3" align="right">11</entry></row><row><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="right">27</entry><entry namest="col3" nameend="col3" align="right">18</entry></row><row><entry namest="col1" nameend="col1" align="right">4</entry><entry namest="col2" nameend="col2" align="right">38</entry><entry namest="col3" nameend="col3" align="right">25</entry></row><row><entry namest="col1" nameend="col1" align="right">5</entry><entry namest="col2" nameend="col2" align="right">100</entry><entry namest="col3" nameend="col3" align="right">5</entry></row></tbody></tgroup></table></tables>

b₃) improving the thermal resistance by polyorganosiloxane modification.

To demonstrate the improvement of the thermal resistance of the modified polymers prepared by means of Polyorganosiloxandispersionen invention, the samples Nos 1 and 4, a total of three weeks were stored at 150 ° C.. After certain times, was used as measure for the thermal degradation of the Reißdehnung measured.

The results are summarized in Table 3 and show that the entered through the temperature load drop in elongation at break and thus of the elastomeric character of the specimens in which the silicone-modified polyurethane is significantly lower than the non-modified polyurethane. <tables id="tabl0003" num="0003"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Annealing time (hours)</entry><entry namest="col2" nameend="col3" align="center">Drop in elongation at break in% of the initial value</entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Sample 1 (0% silicone)</entry><entry namest="col3" nameend="col3" align="center">Sample 4 (38% silicone)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">24</entry><entry namest="col2" nameend="col2" align="right">72</entry><entry namest="col3" nameend="col3" align="right">76</entry></row><row><entry namest="col1" nameend="col1" align="right">86</entry><entry namest="col2" nameend="col2" align="right">60</entry><entry namest="col3" nameend="col3" align="right">66</entry></row><row><entry namest="col1" nameend="col1" align="right">170</entry><entry namest="col2" nameend="col2" align="right">31</entry><entry namest="col3" nameend="col3" align="right">42</entry></row><row><entry namest="col1" nameend="col1" align="right">360</entry><entry namest="col2" nameend="col2" align="right">17</entry><entry namest="col3" nameend="col3" align="right">25</entry></row><row><entry namest="col1" nameend="col1" align="right">500</entry><entry namest="col2" nameend="col2" align="right">14</entry><entry namest="col3" nameend="col3" align="right">20</entry></row></tbody></tgroup></table></tables>

example 6

Were measured by mixing a polysiloxane-modified polypropylene glycol dispersion as in Example 5 a) having the same composition, each with stoichiometric amounts produced of isophorone diisocyanate sample body into which at different measurement frequencies, dielectric constant (DK), the loss angle (tan δ) and resistivities were. The results of these measurements are summarized in Table 4 and show the substantial improvement, ie reduction of the dielectric constant and the loss angle or an increase of the resistivity as a result of the modification according to the invention with polysiloxanes.<tables id="tabl0004" num="0004"><table frame="all"><title>Table 4</title><tgroup cols="5" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="31.50mm" /><colspec colnum="2" colname="col2" colwidth="31.50mm" /><colspec colnum="3" colname="col3" colwidth="31.50mm" /><colspec colnum="4" colname="col4" colwidth="31.50mm" /><colspec colnum="5" colname="col5" colwidth="31.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col5" align="center">- Measuring frequency 10 kHz -</entry></row><row><entry namest="col1" nameend="col1" align="center">Sample no.</entry><entry namest="col2" nameend="col2" align="center">Polysiloxane content (%)</entry><entry namest="col3" nameend="col3" align="center">DK</entry><entry namest="col4" nameend="col4" align="center">tan δ</entry><entry namest="col5" nameend="col5" align="center">Spec. Resistors. x 10⁶ (.OMEGA..cm)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">6</entry><entry namest="col2" nameend="col2" align="right">0</entry><entry namest="col3" nameend="col3" align="char" char=",">4.7</entry><entry namest="col4" nameend="col4" align="char" char=",">0,122</entry><entry namest="col5" nameend="col5" align="right">316</entry></row><row><entry namest="col1" nameend="col1" align="right">7</entry><entry namest="col2" nameend="col2" align="right">15</entry><entry namest="col3" nameend="col3" align="char" char=",">4.8</entry><entry namest="col4" nameend="col4" align="char" char=",">0.118</entry><entry namest="col5" nameend="col5" align="right">313</entry></row><row><entry namest="col1" nameend="col1" align="right">8th</entry><entry namest="col2" nameend="col2" align="right">29</entry><entry namest="col3" nameend="col3" align="char" char=",">4.1</entry><entry namest="col4" nameend="col4" align="char" char=",">0,082</entry><entry namest="col5" nameend="col5" align="right">535</entry></row><row><entry namest="col1" nameend="col1" align="right">9</entry><entry namest="col2" nameend="col2" align="right">40</entry><entry namest="col3" nameend="col3" align="char" char=",">3.7</entry><entry namest="col4" nameend="col4" align="char" char=",">0.062</entry><entry namest="col5" nameend="col5" align="right">790</entry></row></tbody></tgroup></table></tables>

The same measurements were also at higher frequencies durchgeführt, namely up to 10 MHz. The results shown in Table 4 were confirmed without exception.

example 7

100 parts of polytetramethylene glycol (molecular weight 1000), 50 parts of OH-terminated polydimethylsiloxane with 10 000 mPa.s, 3 parts aminopropylmethyldiethoxysilane 2 parts of tetraethoxysilane and 12 parts of the stabilizer from Example 1 were mixed together at room temperature and treated with an Ultra-Turrax homogenizer. After 2 days of standing to give a dispersion of crosslinked polyorganosiloxane particles into the polytetramethylene glycol.

Using this inventive polyorganosiloxane dispersion polyurethane specimens were prepared as follows: 6 parts of the polyorganosiloxane dispersion, 3 parts diphenyl methane diisocyanate, 91 parts of a commercial polytetramethylene glycol prepolymer having an NCO content of 7.9%, and 8 parts of 1,4-butanediol were at a temperature of 60 ° C mixed, about 3 min stirred, then heated to 100 ° C heated in a 110 ° C mold vorgeheizte poured at 110 ° C for 16 hour cured. This gave a highly viscous elastomer having a content of about 3% silicone elastomer and having a Shore A hardness of 85th

For comparison purposes, a polyurethane specimen without the inventive dispersion and without diphenylmethane diisocyanate was prepared in the same manner.

The test specimens prepared using the dispersion of the invention had a much smoother "hand", ie a lower coefficient of friction. This was (the company Daimler Benz measurement based on the delivery specification no. 5306) confirmed by measuring the coefficient of friction, which was for the unmodified specimens 0.39 and for an inventively modified specimen 0.30.

Further, the abrasion of the test specimen was measured according to DIN 53516th The measurement resulted in the unmodified specimens abrasion of 320 mg and at the inventively modified specimen abrasion of only 170 mg. The specimen prepared using the Polyorganosiloxandispersion invention had therefore a better by almost 50% abrasion resistance than the unmodified sample.

Further, tear strength and elongation at break measurements were performed on both test specimens, which led to identical values ​​within the measurement accuracy.

These results show that the surface properties of the modified polymers according to the invention compared to unmodified polymers are significantly improved.