DE1595741A1 - Process for the preparation of organosilicon polymers - Google Patents

Description

Process for the preparation of organosilicon polymers.

The present invention relates to a method of manufacture of organosilicon polymers by causing the intercondensation of silanol groups containing organosilicon compounds with silylamines.

According to the prior art, organopolysiloxane polymers that are suitable for the production of organopolysiloxane elastomers, generally by Aguilibration of mixtures made from materials with low molecular weight, for example cyclic organopolysiloxanes such as octamethylcyclotetrasiloxane and organosiloxanes having terminal triorganosiloxy units, for example Trimethylsiloxy units.

Even if the equilibration process is reasonably satisfactory Organopolysiloxane rubbers lead, but it has a number of disadvantages. For example the equilibration requires the use of higher temperatures, for example up to 175 ° C, with a further disadvantage that needs to be heated over long periods of time. Furthermore, it is state of the art characterized by the disadvantage that those produced by equilibration processes Rubber freed from the volatile constituents by evaporation prior to their use Need to become. These volatile fractions can be up to about 14 percent by weight, based on the rubber. Another disadvantage of the prior art is that the equilibration does not lead to the formation of highly viscous organosilicon polymers leads, which chemich combined diorganosilicon hydrocarbon radicals and diorganosiloxy radicals exhibit. Furthermore, the organosilicon polymers prepared by equilibration must be freed from the equilibration catalyst to reduce the stability of the Exclude polymers.

In contrast, the present invention provides a method for increasing the molecular weight of organosilicon compounds containing silanol groups created, which consists in having a difunctional silylamine with a Organosilicon material containing silanol groups is mixed and the two components lets react with one another, the difunctional silylamine having the formula YSi (R ") 2Z has, in which Y is a monovalent amine residue, which has a silicon-nitrogen bond is bonded to the silicon and which corresponds to the formula -NRR 'or of a heterocyclic m. in is derived, R is alkyl or cycloalkyl, R 'is hydrogen or an R radical and R ″ a monovalent hydrocarbon radical or a halogenated one means monovalent hydrocarbon radical. Z means that Same like Y and (OSiR '' '2) n (OSiR''2) Y - residues, R' '' means the same as R "or a Gyanoalkylrest, n is an integer from 5 to 1,500 inclusive; the Mixing and effecting the reaction will be at a temperature on the order of magnitude carried out from 00 to 2000C until the reaction product has a viscosity of at least 500,000 centipoise at 25 ° C; containing the silanol groups Organosilicon material consists of one of the components (a), (b) and (c), which represent the following: (a) is a mixture of essentially monofunctional Silylanin R "33iY and a silanol-end-blocked diorganopolysiloxane, which is essentially consists of chemically combined diorganosiloxy units of the formula R '' '2SiO (b) is a mixture of essentially the silanol end-blocked described under letter (a) Diorganopolysiloxane and an organopolysiloxane containing silanol groups, the consisting essentially of said chemically combined diorganosiloxy units exists, and as end groups those of the formulas R``3SiO0.5 or R '' '3SiO0.5 have.

(c) is a mixture consisting essentially of the silanol end-blocked $ Organosilicon material consists of said chemically combined diorganosiloxy units according to (a) R '' '2SiGSiR' '' 2O - units and containing such silanol groups Organosilicon bodies are composed, which essentially from the said chemically combined tiorganosiioxy units, R '' '2SiGSiR' '' 2O units and a terminal unit according to (b) exist. (A) is used in combination with (b) used in an amount sufficient to ensure that that at least 1 mole of Y residues of (a) is present per mole of silanol residues of (b); the said organosilicon polymer has a ratio of the sum of R ″ and R "'radicals per silicon atom from about 1.95 to 2.001; the symbol G here denotes an alkylene or arylene radical.

The symbols R and R 'in the above formulas mean hydrogen or Alkyl radicals such as methyl, ethyl, propyl, butyl, pentyl, hexyl, Heptyl and octyl groups, also cycloalkyl radicals such as the Oycloheptyl- and cyclohexyl group. The symbol R '' means aryl radicals and halogenated aryl radicals, riie, for example, the phenyl, chlorophenyl, xylyl and tolyl groups, as well as aralkyl radicals such as the phenylethyl and benzyl groups, aliphatic, haloaliphatic and cycloaliphatic Groups such as alkyl and alkenyl groups, cycloalkyl and haloalkyl groups, including the methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl groups, as well as Cyclohexyl-bluoropropyl and pluorobutyl residues. The symbol R111 means all R "residues also cyanoalkyl radicals, such as the cyanoethyl, cyanopropyl and cyanobutyl groups.

The symbol G means arylene radicals such as the phenylene, tolylene and naphthylene groups, also alkylene radicals such as the methylene, ethylene and trimethylene groups. hen in one of the aforementioned formulas the symbols R, R ', R "and R'" ', as well as G more than occur once, they can each have the same remainder or two or mean more radicals different from one another.

A method of making some of the foregoing Silylamines, which are used in accordance with the present invention is in U.S. Patent 2,429,883 described. These include, for example, monofunctional silylamines, such as dimethylaminotrimethylsilane, Dimethylaminodimethyl- (gamma-chloropropyl) -silane, diethylaminodimethylphenylsilane, t-butylaminotrimethylsilane, ethylaminodimethylcyclohexylsilane, cyclohexylaminodimethylvinylsilane, Diethylamino-tri-n-butyl-silane, dimethylphenylmorpholinosilane, trimethylpiperidinosilane; difunctional silylamine such as bis- (dimethylamino) -dimethylsilane, bis- (methylamino) -dimethylsilane, bis- (isopropylamino) -dimethylsilane, bis- (ethylamino) -dimethylsilane, bis- (sec-butylamino) -dimethylsilane, bis- (Dimethylamino) -Methylvinylsilane, bis- (Dimethylamino) -Methylphenylsilane, bis- (Di-ethylamino) -Methylvinylsilane, bis- (isopropylamino) -diphenylsilane, bis- (pyrrolidino) -methylphenylsilane and dimethyldipiperidinosilane.

The organosilicon compounds containing silanol groups include polymers of the formula in which R "'and G are as defined above, a is 0 or 1 and x is an integer from 1 to 5 inclusive; if a = O, x = 1 and y is equal to n defined above and preferably equal to 100 to 1,000 inclusive; if a and x are both equal to 1, y can be an integer from 2 to 100 inclusive.

The organosilicon compounds of the formula (3) containing silanol groups also include silanol-end-blocked diorganopolysiloxanes. These materials can be produced by hydrolysis processes known per se, for example by hydrolysis of a diorganodihalosilane of the formula R "'2SiX2 in which the symbol R1" has the meaning given above and X means a halogen atom. Another production method is equilibration of cyclic polydiorganosiloxanes of the formula in which b is an integer from 1 to 8 inclusive. The drganopolysiloxane compounds formed can be returned to polydiorganosiloxanes with terminal silanol groups and lower molecular weight in order to ensure easier removal of the equilibration catalyst from the end product, the need for evaporation being eliminated. Controlled amounts of water can be added to achieve the desired ignition viscosity.

The diorganopolysiloxanes with terminal silanol groups, the produced by the regeneration of organopolysiloxanes with a higher molecular weight preferably have viscosities from 200 to 50,000 centipoise at 25 ° C.

Process for the production of organosilicon polymers with silanol groups, which are encompassed by formula (3) and chemically combined silicon-hydrocarbon freæte are also well known in the art.

These polymers can have viscosities that differ from liquid ones extend to the waxy area, whatever of the Mole percent depends on silicon hydrocarbon siloxy units. Preferably have polymers with silanol groups containing silicon hydrocarbon siloxy units, 5 up to 25 mole percent silicon-hydrocarbon-siloxy units and 95 to 5 moles Percent diorganosiloxy units.

To the silanol end-blocked liorganopolysiloxanes of the formula (3) include polymers consisting essentially of dimethylsiloxy units and copolymers from dimethylsiloxy units with one or more diphenylsiloxy units, methylphenylsiloxy units, Me thylcyanoäthylsiloxy-units and Methyltrifluorpropylsiloxy-units exist. Smaller amounts of rhodium siloxy and methylsiloxy units can also be added be.

In certain cases, organopolysiloxanes containing silanol groups can be used of the formula (4) R '' '(R' '' 2SiO) mII in combination with the silanol groups Organosilicon materials according to formula (3) are used, namely in; tight, which cause organopolysiloxane rubbers to be created in which the The ratio of the sum of the R and R '' 'radicals is 1.95 to 2.001, where R and R '' 'have the meaning given above and m is an integer of at least 3 means up to and including 1,000.

The organosilicon compounds containing silanol groups of the formula (4) By equilibrating a mixture of 0.01 to 20 ol percent R '' '3SiO0.5 units and 80 mole percent to 99.9 mole percent of R "" 2SiO units are produced. The organopolysiloxane of the formula (4) containing silanol groups can also be 0.02 to 8 percent by weight of hydroxyl residues, that are bonded to silicon, contain, based on the total weight of the organopolysiloxane containing silanol groups. Furthermore, these materials can have viscosities up to 50,000 centipoise at 25 ° C.

The organopolysiloxane polymers or rubbers according to the present Invention can be made, consist essentially of chemically combined units of the formula (2).

These rubbers can have viscosities from 500,000 entipoise to 650 Possess millions of centipoise at 25 ° C. Some of these organopolysiloxane rubbers can be used in the same or similar ways as those in U.S. Patents 2,448,756, 2,448,556, and 2,521,528. The rubbers produced according to the invention can also be used per 100 parts of rubber be ground with 30 to 300 parts of filler. Such fillers are for example reinforcing fillers, such as fumed silica (= silicon dioxide obtained from the gas phase) as well as extending fillers such as titanium dioxide etc. Perner can also be known per se Peroxide catalysts are incorporated.

The organopolysiloxane rubbers according to the present invention can also be characterized in that they are terminal Units of the formula R '' '(5) Z SiO 0.5 R contain, in which formula R', 'die has the meaning given above and Z is R "or R" ".

The organopolysiloxane produced according to the present invention - rubbers, which essentially consist of chemically combined dimethylsiloxy units, can have molecular weights up to 1 million. Such rubbers according to the invention contain less than 1.0 percent by weight of volatile ingredients, based on on the weight of the rubber.

For example, some of the rubbers which are produced according to the present invention have the following mean formulas where w is an integer from 1 to 10 inclusive and s, g and z are from about 5 to about 50; the terminal units shown can be obtained by the reaction of terminal silanol groups with R "3SiY.

The method of the present invention can be carried out by that one has a difunctional silylamine with an organosilicon material containing silanol groups at one temperature mixed together between 0 and 2000C. Temperatures between 20 and 1700 ° C. are preferably maintained.

The order of addition of the various reactants is not of critical importance. For example, if you have a monofunctional silylamine together with a difunctional silylamine in combination with a dilanol end group containing diorganopolysiloxane, it is preferable to use 0.01 to 1 part of monofunctional silylamine per 1 part of difunctional silylamine. However, Bs can be as little as 0.001 part of monofunctional Silylamine can be used per 1 part of difunctional silylamine. In most In cases it is preferable to end the monofunctional silylamine first to add blocked diorganolpolysiloxane and only then the difunctional Silylamine. In some cases, the addition of the silylamine can be in the form of a mixture of monofunctional and difunctional 3ilylamine. In certain cases in which monofunctional silylamines are used, which dimethylamino radicals contain, which are bonded to silicon, the monofunctional silylamine to a mixture of difunctional silylamine and J) iorganopolysiloxane with a terminal Silanol grouping can be added as long as the viscosity of the mixture remains below 50,000 centipoise at 25 ° C.

Preferably, the process of the invention is below practical Anhydrous conditions performed to avoid any undesirable hydrolysis of Y residues Turn off the silylamine before intercondensation with the silanol groups containing organosilicon material has taken place. In those cases where practical Anhydrous conditions can be very rapid Encore an excess of silylamine make further intercondensation difficult. In contrast the presence of moisture causes further intercondensation as a result of the Creation of further silanol groups through the hydrolysis of terminal Y residues ... Es it was found that the intercondensation is slowed down significantly if one an organic solvent is used. However, to make stirring easier, you can lower levels of inert organic solvent, such as less than 10 Weight percent, based on the reaction mixture, are entered after the Intercondensation has already progressed quite strongly, by what addition the viscosity of the intercondensation product is reduced. liter can for example Benzene, xylene, toluene and the like find use.

If you use the silylamine in amounts that are not enough to at least one test per silanol residue of the organosilicon material containing silanol groups to make available, in general, unreacted silanol groups were not allowed Liquid organosilicon material after completion of intercondensation. in excess of silylamine beyond the amount necessary to cause the intercondensation of the Silanols with silyl radicals is needed, for example amounts of silylamine that Provide more than 1 to 5 Y radicals per silanol radical, can be inexpensive Lead to results.

The reactions of the present invention are generally most conveniently performed under atmospheric pressure conditions. However, it can can also be worked with negative pressure.

The isolation of the desired rubber can easily be thereby causes that the mixture should first assume a maximum viscosity value leaves and then any unreacted material or by-products at reduced Pressure removed.

The following 3 examples serve to further explain the subject matter of the invention, all parts are parts by weight.

Example 1: 0.38 parts of silylamine were added to 20 parts of silanol end-blocked Polydimethylsiloxane has a viscosity of about 205 centipoise at 2500 during After the addition, the mixture was stirred and kept at a temperature of about 60.degree. The silylamine consisted of a mixture of about 9 parts of bis (dimethylamino) dimethylsilane per part of dimethylaminotrimethylsilane. After 4 hours a rubber was obtained which has an intrinsic viscosity of 2 dl / g in toluene at 250C.

This rubber had a viscosity of about 450 million centipoise at 250C.

A test strip of this rubber was taken at a pressure of 15 mm Heated to 150C for 45 seconds. Relative to its original weight lost this rubber test strip has less than 0.8 weight percent volatiles at this sharp test.

Example 2: 0.002 parts of isopropylaminotrimethylsilane were added 20 parts of polydimethylsiloxane with a terminal silanol group and a viscosity of about 3500 centipoise at 250C.

After stirring the mixture for about 1 hour, it became 0.26 Parts of bis (isopropylamino) dimethylsilane added.

The mixture was then left at normal for 2 hours temperature stand and then heated to 75 ° C for 4 hours. A polydimethylsiloxane was obtained having a viscosity of about 120 million centipoise at 250C. When performing of the test described at the end of Example 1 showed that the loss of volatile constituents was less than one percent.

Example 3: A mixture of 300 parts of silanol-end-blocked polydimethylsiloxane with a viscosity of about 3,600 centipoise at 250C and 5.5 parts of silylamine was heated to 600C. The silylamine consisted of a mixture of about 15 percent by weight DimetM laminotrimethylsilanefi 28 weight percent bis (dimethylamino) dimethylsilane and 57 weight percent bis (dimethylamino) methylvinylsilane. After about 4 hours a rubber was obtained which had a viscosity of about 630 million centipoise owns at 2500. Its intrinsic viscosity in toluene is 2.2 dl / g. Based on its production method consists of this rubber from polydimethylsiloxane blocks, linked by repeating lilethylvinylsiloxy units are, with the binding of the polydimethylsiloxane blocks' 2rimethylsiloxy-3 units arranged are. In the test according to Example 1, this rubber lost less than 0.75 percent by weight of volatile components.

100 parts of the rubber prepared as just described with 30 parts of fumed silica (= silicon dioxide obtained from the gas phase) and 2 parts Grind dicumyl peroxide. The resulting composition was then 10 minutes on 1600C heated. A test strip made from the product cured in this way has an average tensile strength of 70.35 kg / cm2 and an elongation at break of 375%.

Example 4: In about 7 hours, 0.33 parts of silylamine blocked in small proportions to a mixture of 8 parts silanols on methyltrifluoropropylpolysiloxane endblocked with a viscosity of about 10,000 centipoise at 25 ° C and 12 parts silanol: n Polydimethylsiloxane having a viscosity of about 700 centipoise at 25 ° C was added. During this addition the mixture was stirred and kept at a temperature of about 600C held. About 99 percent by weight of the silylamine was bis (dimethylamino) dimethylsiland and one percent by weight of dimethylaminotrimethylsilane. received a cloudy product, which was heated to 1250C with stirring and a stream of dry nitrogen. The resulting product is then extracted with toluene, and in 75 one yield obtained a non-sticky rubber.

Based on its production method, this is rubber from repeating methyltrifluoropropylsiloxane and solydimethylsiloxane blocks put together and end-blocked with trimethylsiloxy units.

The rubber just described was made in a proportion of 30 parts Filler per 100 parts of rubber with fumed siliza (= obtained on the gas phase Silicon dioxide).

The resulting mixture was then mixed with about 2 parts of benzoyl peroxide hardened. A test strip of the resulting milled mixture was left for 30 minutes Press hardened at a temperature of 160 ° C. The hardened or crosslinked in this way Product has valuable elastomeric and insulating properties.

Example 5: There was 0.002 part of morpholinotrimethylsilane to 10 parts Silanol end blocked polydimethylsiloxane having a viscosity of about 3,500 centipoise added at 250C. The resulting mixture was stirred for about 1 hour 65 ° C heated.

Then 0.270 parts of bis (pyrrolidino) methylphenylsilane was added and heated to 6500 for a few hours while stirring. This gave one High molecular weight rubber.

This rubber was made with fumed silica (= extracted from the gas phase Silica) in an amount of about 300 parts filler per 100 parts rubber grind. Subsequently, the resulting. Mix about 2 parts of benzoyl peroxide ground in. A test strip made from the resulting mill mix was used for 30 minutes Press hardened at 1600C. It turned out that the hardened product had valuable insulating and has elastomeric properties.

Example 6: At a temperature of 80 ° C., 2.5 parts of bis (dimethylamino) dimethylsilane were added 100 parts of silanol end-blocked; n; ; ethylsiloxane added, the al1s a blend of 90 weight percent silanol endblocked polydimethylsiloxane and 10 percent by weight of silanol group-containing methylsiloxane, which of 0.058 mole percent of chemically combined trimethylsiloxy units and 99.942 Mol percent is composed of dimethylsiloxy units, with about 3.5 silanol radicals each per chemically combined trimethylsiloxy units are bonded to silicon. To A polydimethylsiloxane rubber with terminal ends is obtained for about 1.5 hours Trimethylsiloxy units and a viscosity of about 380 million centipoise at 250C. imine mixture of 100 parts of the aforementioned rubber and 30 parts of fumed silica were mixed with 2 parts of benzoyl peroxide.

A test strip made from this composition was used for 30 minutes at 160.degree press hardened. The resulting product has valuable elastomeric and insulating properties.

Example 7: A mixture of 50 parts of silanol-end blocked polydimethylsiloxane having a viscosity of about 3,500 centipoise at 250C and 0.008 part diethylaminotrimethylsilane was stirred at 1000C for about 1 hour. Then 0.8 parts of bis (diethylamino) dimethylsilane was added added. After stirring the mixture for a further hour at 1000C, became a rubber with a viscosity of about 200 million centipoise at 250C obtain.

Example 8: a sense mixture of 0.175 parts of bis (dimethylamino) dimethylsilane and 0.03 part of dimethylaminotrimethylsilane was endblocked to 20 parts of oilanol Polydimethylsiloxane with a viscosity of 15,000 at 250C was added. The resulting Mixture was continuously stirred for 6 hours at a temperature of 00G. ; 1an received a polydimethylsiloxane rubber with a viscosity of 10 million Centipoise at 25 ° C.

Example 9: There were 0.25 parts of bis (isopropylamino) dimethylsilane and 0.04 part of dimethylaminotrimethylsilane to 20 parts of a silanol end-blocked Added copolymers, which are composed of chemically combined dimethylsiloxy-3units and diphenylsiloxy units and has a viscosity of 5,000 centipoise owns at 2500. The addition was carried out at a temperature of 600C carried out, the mixture being stirred. After about 5 hours, a rubber with a Obtained viscosity of about 4 million centipoise at 250C. Based on the production method is the rubber from chemically combined dimethylsiloxy units, Diphenylsiloxy units and one-stop trimethylsiloxy units composed.

Example 10: Within a period of 6 hours were in small Portions 219 parts of tetramethylsilphenylene-1,3-diol to a mixture of 360 parts Octamethylcyclotetrasiloxane, as well as enough potassium hydroxide to get one concentration Ensure of 50 parts of catalyst per 1 million parts of mixture is added. During the addition, the temperature of the mixture was kept at 160 ° d. The raw one The product was freed from the catalyst using phosphoric acid. It consists of silanol end-blocked Polymer made up of chemically combined tetramethylsilphenylenesiloxy units and dimethylsiloxy units and has a viscosity of 1,500 Oentipoise at 250C. a mixture of 100 parts of the above-mentioned silanol end-blocked Polymers, 2 parts bis (isopropylamino) methylvinylsilane and 0.3 part dimethylaminotrimethylsilane was heated to 160 ° C for 2 hours. A rubber having a viscosity was obtained of over 500,000 centipoise at 250. Based on the method of manufacture the rubber consists of about 25 mol percent chemically combined tetramethylsilphenylenesiloxy units, approximately 75 mole percent dimethylsiloxy units and terminal trimethylsiloxy units.

The present invention thus creates a new, chemically unique and surprisingly advanced method of manufacture from Organosilicon rubbers with high molecular weight and very low proportions of volatile ingredients. These rubbers can have the same uses like the rubbers obtained by conventional equilibration processes which require the use of equilibration catalysts - The rubbers produced according to the invention do not require any exemption from volatile ingredients, as these are practically absent or almost entirely absent. A further advance of the present invention is that high molecular weight Block copolymers of silicon-hydrocarbon-siloxane, polydiorganosiloxane and Organosilicon polymers, the repeating chemically combined siloxy units with functional pegs such as olefinically unsaturated hydrocarbon radicals, the are bonded to silicon, have, can be produced.

/ Claim:

Claims (1)

Method for increasing the molecular weight of silanol groups containing organosilicon compounds, characterized in that one is a difunctional Silylamine with an organosilicon compound containing the silanol group mixes with each other and allows to react, the difunctional silylamine being the Pormel YSi (R ″) 2Z corresponds, Y a monovalent amine radical which has a silicon-nitrogen bond is bonded to silicon, either -NRR 'or a heterocyclic A-yne radical, R is an alkyl or cycloalkyl radical, R 'is hydrogen or the same as R, R "is monovalent hydrocarbon radical or a halogenated monovalent hydrocarbon radical, Z equals Y, or (OSiR '' '' '2) n (OSiR "2) Y radicals, R' '' the same as R" or one Cuyanoalkyl radical and n is an integer from 5 to 1,500, and that mixing and reacting at a temperature ranging from 0 ° C to 2000C for so long will until the resulting product has a viscosity of at least 500,000 entipoise at 25 ° C, the uranosilicon compound containing silanol groups The best can be from (a) a mixture of the essentially monofunctional 3ilylamine R "3SiY and Silahol-end blocked diorganopolysiloxane, which essentially consists of chemically combined diorganosiloxy units of the formula R '' '2SiO, (b) a mixture consisting essentially of said silanol end-blocked diorganopolysiloxane according to (a) and a silanol - @ patent claim - @ groups contain @ en Graganopolysiloxane consists essentially of said chemically combined Diorganosiloxy units and terminal units of the formulas R "3SiO0.5 and R '' '3SiO0,5 @ usam @ is substituted, (c) a mixture which essentially consists of silanol-endolocked Organosilicon material consists essentially of said chemis @ a kompinicrten Diorganosiloxy units according to (a) and R '' '2SiGSiR' '' 2 @ units and silanol groups containing organosilicon material is composed practically of said chemical complexed diorganosiloxy units, R '' '2SiGSiR' '' 2O units and a terminal unit according to (b), where (a) in combination with (@) is used in such an amount that is sufficient to contain at least 1 mole of Y radicals (a) to provide pro i @ ol silanol residues of (b) and the said organosilicon polymers a ratio of the sum of R "and R" 'radicals per silicon atom of about 1.95 to 2.001 have 1nd G denotes an alkylene or wrylene radical.