Organofunctional siloxane mixtures

ES 2 338 007 T3

DESCRIPTION

Organofunctional siloxane mixtures.

The present invention relates to silane mixtures comprising novel organofunctional siloxanes.

The present invention further relates to a process for preparing such mixtures and to their use.

1-Organomethylchlorosilanes and 1-organomethylalkoxysilanes have been known for a long time. The 1-aminomethylsilanes, for example, can be obtained by reacting a chloromethylsilane with ammonia or an organic amine. Thus, one possible reaction is that of a chloromethylalkoxysilane with ammonia or ethylenediamine to give (after removal of the salt load produced) a 1-aminomethylalkoxysilane or N- (2-aminoethyl) -1-aminomethylalkoxysilane, respectively.

Additionally, organosiloxanes or mixtures thereof are obtained, for example, by directed hydrolysis or condensation of organofunctional chlorosilanes or alkoxysilanes, eg EP 1 031 593 A2, EP 0 927 735 A1, Vdovin, VM et al., "Addition of alkoxysilane- hydrides a unsaturated nitriles and hydrogenation of the omega-cyano-alkylalkoxysilanes obtained ”, Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science, no. 11, 1961, pages 1872-1876. A particular problem associated with the preparation of polyfunctional siloxane oligomers is the distinctly different hydrolysis or condensation characteristics of the individual organoalkoxysilanes and organochlorosilanes.

EP 0 960 921 A2, EP 0 716 128 A2, EP 0 716 127 A2, and EP 0 675 128 A1 describe aqueous solutions of organosilanes and organosiloxanes with 3-aminopropyl functionality and OH functionality. In these organosilane systems, hydrolysis is virtually complete.

EP 0 518 057 A1 and DE 196 24 032 A1 describe mixtures of vinyl-functional and alkyl-functional cyclic and open-chain siloxane oligomers which also carry alkoxy groups. Such mixtures are used, for example, to make mineral surfaces and water-repellent powders, as crosslinking agents for thermoplastic polyolefins, and as adhesion promoters in adhesives and sealants.

Furthermore, DE 198 34 990 describes mixtures of cyclic and open-chain siloxane oligomers containing 3-acryloyloxypropyl and 3-methacryloyloxypropyl groups.

Siloxane oligomers of this class can be used for surface treatment or modification of mineral or powdery substances, such as titanium dioxide, talc, clay, silicas, quartz, kaolin, aluminum hydroxide, magnesium hydroxide, bentonite, montmorillonite, mica ( Muscovite mica), calcium carbonate (chalk, dolomite), for example, eg EP 0 101 787 A1. Such siloxane oligomers are also used as adhesion promoters, for example, in kaolin-filled rubber compounds, in adhesives and sealants, in inks and paints, and in the construction industry.

It was an object of the present invention to provide additional mixtures comprising organofunctional siloxanes.

This object is achieved according to the invention as specified in the claims.

Surprisingly, it has been found that a mixture of straight chain, branched and cyclic siloxanes of the general formula can be obtained ^Rx^Yes(4-x) / 2 ^(I) where, in formula I, x is 1, 2 or 3, the substituents R are (i) organofunctional groups selected from -CH2-SH, -CH2-S- (CO) -R ',

<img file="ES2338007T3_D0001.tif" />

OH OR CH,

CH₂-OCC = CH₂, —CH₂-OCC = CHj. —CHj-NH— (CO) -NH₂

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-CH₂- (OC₂H₄)_to-OH with a = 1 to 10, -CH₂- (OC₂H₄)_b-OR 'with b = 1 to 40, preferably with b = 1 to 20, - (CH₂) -NH₂, - &lt;CH₂) -NHR ', - (CH₂) -NR '₂, - (CH2) -NH (CH2) 2-NH2, - (CH2) -N [(CH2b-N ^ hy - (CH₂) -NH (CH₂)₂-NH (CH₂)₂-NH₂, in which R 'is a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, (ii) hydroxyl, methoxy, ethoxy, 2-methoxyethoxy, isopropoxy, n-propoxy, isobutoxy and / or n- groups butoxy, and (iii) where appropriate, alkyl, alkenyl, isoalkyl, cycloalkyl or fluoroalkyl groups having 1 to 18 carbon atoms or aryl groups having 6 to 12 carbon atoms, except that no more than one group organofunctional (i) is bound by silicon atom, the ratio of the molar ratio of residue (ii) to silicon is 1 to 2, preferably 1.2 to 1.6, and the degree of oligomerization for the compounds of general formula I is in the range of 2 to 50, preferably from 2 to 30, using as component A at least one organofunctional trialkoxysilane in position 1 or an organofunctional methylalkoxysilane in position 1 and, where appropriate, as component B at least one alkyl-, alkenyl-, isoalkyl-, cycloalkyl- or fluoroalkyl-trialkoxysilane having 1 to 18 carbon atoms and / or phenyltrialkoxysilane and / or alkyl-, alkenyl-, isoalkyl-, cycloalkyl- or fluoroalkyl-methyldialkoxysilane having 1 to 18 carbon atoms and / or phenylmethyldialkoxysilane and, where appropriate, as component C a tetraalkoxysilane, subjecting components A, where appropriate B, and, where appropriate, C, in succession or in mixture to targeted hydrolysis and / or condensation using 0.5 to 1.8 moles of water, preferably 0.8 to 1.2 moles, per mole of Si and using 0.1 to 10 times, preferably 0.5 to 5 times, the amount by weight of methanol and / or ethanol and / or at least one alcohol corresponding to the alkoxy groups of (ii), based on the alkoxysilanes used, at a temperature of 10 to 120 ° C, preferably 25 to 90 ° C, more preferably 35 to 80 ° C, and subsequently treating the product mixture by distillation at atmospheric pressure or at reduced pressure and at a temperature in the liquid phase of up to 120 ° C. During the treatment of the crude product, it is possible if appropriate to add an organic or inorganic acid in order to stabilize the system. The treatment is conveniently accompanied by the removal of the free alcohol product and any residues of the monomeric starting materials that have not undergone hydrolysis. Accordingly, it is possible to provide a mixture of 1-position organofunctional siloxanes which, compared to comparable prior art systems, has an even lower content of organic constituent, in particular a low point, high volatility alcohol of hydrolysis. of inflammation, which is therefore particularly advantageous in relation to the problem of VOCs. It is surprising, and therefore in a particularly advantageous way, that in this case as well as the hydrolysis and / or condensation can be conducted in a targeted manner without any additives foreign to the system, such as a hydrolysis and / or condensation catalyst.

The siloxane mixtures of the invention obtained in this way are generally homogeneous, transparent to slightly opalescent, colorless to slightly yellow, storage stable and low viscosity liquids that preferably have a flash point&gt; 100 ° C in order to increase product safety.

By the method of preparation set forth above, it is advantageously possible to produce the siloxane mixtures of the invention which preferably possess a statistical distribution of different functional units, that is, polyfunctional units [-Si (R) (R) O-] in the meaning of claim 1.

The present systems are further distinguished from comparable systems by more efficient wetting of the surfaces.

It is also advantageous that the boiling point of the mixtures of the invention is generally situated at a temperature&gt; 200 ° C.

The systems of the invention can advantageously be applied both in concentrated form and in the form of an alcoholic or aqueous formulation or of a formulation comprising water and alcohol.

The present invention accordingly provides a mixture comprising straight chain, branched and / or cyclic siloxanes of general formula I ^Rx^Yes(4-x) / 2 ^(I) where x is 1, 2 or 3,

ES 2 338 007 T3 the R substituents are (i) organofunctional groups selected from -CH₂-SH, -CH₂-S- (CO) -R ',

<img file="ES2338007T3_D0002.tif" />

-CH₂- (OC₂H4) a-OH with a = 1 to 10, -CHrCO-QHOb-OR 'with b = 1 to 40, - (CH₂) -NH₂, - &lt;CH₂) -NHR ', - (CH₂) -NR '₂, - (CH2) -NH (CH2) 2-NH2, - (CH₂) -N [(CH2) 2-NH2] 2 and - (CH2) -NH (CH2) 2-NH (CH2) 2-NH2, in which R 'is a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, (ii) hydroxyl, methoxy, ethoxy, 2-methoxyethoxy, isopropoxy, n-propoxy, isobutoxy and / or n-butoxy groups, and (iii) where appropriate, alkyl, alkenyl, isoalkyl, cycloalkyl or fluoroalkyl having 1 to 18 carbon atoms or aryl groups having 6 to 12 carbon atoms, With the exception that no more than one organofunctional group (i) is attached per silicon atom, the ratio of the molar ratio of remainder (ii) to silicon is 1 to 2, and the degree of oligomerization for compounds of the General formula I is in the range of 2 to 50.

The present siloxane mixtures preferably have an alkoxy group content of greater than 0.001% by weight and less than 60% by weight, more preferably 0.1 to 50% by weight, and particularly preferably 0.5 to 40% by weight, based on the weight of the siloxanes present.

In an inventive mixture, the R substituents preferably consist of (i) groups 1-aminomethyl, N (2-aminoethyl) -1-aminomethyl, N, N-di (2-aminoethyl) -1-aminomethyl, N- [ N '- (2-aminoethyl) -2-amino-ethyl] -1-aminomethyl, N-methyl-1-aminomethyl, N- (n-butyl) -1-aminomethyl, N-cyclohexyl-1-aminomethyl, ureidomethyl or N-phenyl-1-aminomethyl, and (ii) methoxy, ethoxy, 2-methoxyethoxy, propoxy and / or butoxy groups, and (iii) where appropriate, methyl, vinyl, ethyl, propyl, isobutyl, octyl groups, hexadecyl or phenyl.

Below are possible examples of some preferred cyclic open chain siloxane oligomer systems: 1-aminomethyl / tridecafluorotetrahydro-1,1,2,2-tetrahydrooctyl- / hydroxy-, methoxy- or ethoxysiloxane, the groups being alkoxy preferably methoxy or ethoxy groups, although ethoxy and methoxy groups may also be present next to each other, as well as hydroxyl groups.

The invention further provides a process for preparing an inventive mixture of cyclic and open chain siloxane oligomers by directed hydrolysis and co-condensation using as component A at least one trialkoxysilane with organomethyl functionality at position 1 or a methyldialkoxysilane with organomethyl functionality at position 1 and , if desired, as component B at least one alkyl-, alkenyl-, isoalkyl-, cycloalkyl- and / or fluoroalkyl-trialkoxysilane having 1 to 18 carbon atoms and / or phenyltrialkoxysilane and / or alkyl-, alkenyl-, isoalkyl-, cycloalkyl- and / or fluoroalkyl-methyldialkoxysilane having 1 to 18 carbon atoms and / or phenylmethyldialkoxysilane, and, where appropriate, as component C, a tetraalkoxysilane, with components A, where appropriate B, and, where appropriate C, subjecting in succession or as a mixture, to directed hydrolysis and condensation using 0.5 to 1.8 moles of water per mole of Si and 0.1 to 10 times the amount by weight of at least one alcohol corresponding to the alkoxy groups of (ii), based on the alkoxysilanes used, at a temperature of 10 to 95 ° C, and subsequently removing from the product mixture the alcohol introduced and the alcohol released in the course of the reaction, by distillation at atmospheric pressure or at reduced pressure and at a temperature of the liquid phase of up to 120 ° C.

Non-exclusive examples of the starting compounds, or combinations thereof, to prepare the inventive mixtures include the following:

- For component A:

1-aminomethyltrialkoxylanes, N-aminoethyl-1-aminomethyltrialkoxysilanes, N-aminoethyl-N-aminoethyl-1-aminomethyltrialkoxysilanes, N-methyl-1-aminomethyltrialkoxysilanes, Nn-butyl-1-aminomethyltrialkoxysilanes, N-cyclohexyl- 1trialkoxysilanes, N-aminomethyltrialkoxysilanes Phenyl-1-aminomethyltrialkoxysilanes, 1 -aminomethylmethyldi-alkoxy4

ES 2 338 007 T3 silanes, N-aminoethyl-1-aminomethylmethylmethyldialkoxysilanes, N-aminoethyl-N-aminoethyl-1-aminomethylmethyldialkoxysilanes, N-methyl-1-aminomethylmethyldialkoxysilanes, Nn-butyl-1-aminomethylmethyldialkoxysilanosilanes, N-aminoethyl-1-aminomethyldialkoxysilanesomethyl-1-aminomethylmethyldialkoxysilanosilanes, , N-phenyl-1-aminomethylmethyldialkoxysilanes, 1-glycidyloxymethyltrialkoxysilane, 1-methacryloyloxymethyltrialkoxysilane, and N-ureidomethyl-trialkoxysilane.

- For component B:

methyltrialkoxysilanes, ethyltrialkoxysilanes, n-propyltrialkoxysilanes, isobutyltrialkoxysilanes, n-octyltrialkoxysilanes, isobutyltrialkoxysilanes, n-octyltrialkoxysilanes, isooctyltrialkoxysilanes, hexadecyltrialkoxysilanes, phenyltrialkoxysilanes and vinyltrialkoxysilanes.

- For component C:

tetraalkoxysilanes, with methoxy, ethoxy, and propoxy being preferred for the alkoxy groups mentioned above.

The process of the invention is generally carried out as follows:

Usually, first, Component A, Component B if used, and Component C if used are introduced into the reaction vessel. A solvent and / or diluent, methanol or ethanol for example, can be added to the alkoxysilane mixture. It is also convenient to add the amount of water calculated for the reaction, conveniently with thorough mixing, for example with stirring. Before or after the addition of water, it is possible to heat the reaction mixture and, after the reaction, treat the resulting product mixture by distillation as indicated. The distillation treatment of the product mixture is preferably conducted at a temperature in the range of 50 to 120 ° C at atmospheric pressure and / or at reduced pressure. In this case it is possible if desired to add an acid from the group including hydrochloric acid, sulfuric acid, formic acid, acetic acid, and citric acid, to name only a few.

In the process of the invention, components A, B, and C are preferably used in an A: B: C molar ratio of 1: 0: 0 to 1: 10: 0, preferably 1: 0: 0 to 1: 4: 0, or 1: 0: 0 to 1: 0: 10, preferably 1: 0: 0 to 1: 0: 4, or 1: 0: 0 to 1:10:10, preferably 1 : 0: 0 to 1: 4: 4.

In the process of the invention, it is further preferred to use alkoxysilanes having methoxy or ethoxy groups corresponding to the alcohol used as solvent and / or diluent. As a solvent and / or diluent it is also suitable to use methanol or ethanol or a mixture of methanol and ethanol. It is also possible, however, to use other alcohols or alcohol mixtures.

In the process of the invention, the hydrolysis and condensation of the alkoxysilanes used is preferably conducted at atmospheric pressure at a temperature of 10 to 95 ° C, more preferably 60 to 80 ° C. The reaction is normally conducted at atmospheric pressure. Alternatively, the reaction can be conducted under reduced pressure or superatmospheric pressure. The reaction mixture is allowed to react adequately for 2 to 8 hours before starting the distillation work-up of the product mixture.

Following the distillation treatment, the product of the invention preferably contains less than 5% by weight of components A, B, and C, and in particular less than 5% by weight, preferably less than 1% by weight, of alcohols free.

The inventive blends of straight chain, branched, and cyclic siloxanes can be advantageously applied to the following illustrative but not limiting uses:

Accordingly, the invention provides the use of an inventive mixture of straight chain, branched and cyclic siloxanes as a composition for surface modification of powdery substances, for silanization of finely divided inorganic fillers and pigments, and for treatment of mineral surfaces. , organic, and metallic, such as concrete, aluminum, steel, and plastics (including PVC and PMMA, to name just two), for example. An inventive mixture of cyclic and straight chain siloxane oligomers can be advantageously used for hydrophobicization of surfaces, for example.

The present invention further provides the use of an inventive mixture of cyclic and straight chain siloxane oligomers as adhesion promoters in charged thermoplastic compounds, eg, HFFR (Halogen-Free Flame Retardant) compounds, for the purpose of obtaining strength. improved mechanics and improved electrical insulation properties.

The present invention further provides the use of an inventive blend of straight chain, branched and cyclic siloxanes as adhesion promoters in adhesives and sealants, including foam sealants, for the purpose of achieving improved service properties, especially characteristics of controlled curing, improved mechanical strength, and improved resistance to moisture.

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The invention further provides the use of an inventive blend of straight chain, branched and cyclic siloxanes for modification and crosslinking of organic resins, as binders in inks and paints having improved service properties, and for coating glass fibers, to the purpose of improved adhesion of these glass fibers in plastics reinforced with them, and for the purpose of obtaining improved mechanical strength.

Particularly advantageous properties of the siloxane mixtures of the invention with respect to the monomeric organoalkoxysilanes used as standard include increased boiling point, increased inflation point, reduced vapor pressure, reduced amount of hydrolysis alcohol released during application. (VOC), and, in particular, the chemical "multifunctionality", which allows a particularly targeted application.