DE2307085A1 - PLATINUM COMPLEX UNSATATULATED SILOXANES AND PLATINUM ORGANOPOLYSILOXANES - Google Patents

Description

Platinum complexes of unsaturated siloxanes and those containing platinum

Organopolysiloxanes

The present invention relates to platinum-siloxane complexes of unsaturated siloxanes which are used as catalysts for hydrosilation are useful and it also relates to curable organopolysiloxane compositions, containing such catalysts. The present invention also relates to methods for making such materials.

Up to now, * various hydrosilization processes were known to the addition of an organosilicon material containing a silicon-bonded hydrogen atom to an aliphatic effecting unsaturated material containing either an olefinic or an acetylenic bond,

309334/1051

being an adduct with a new silicon-carbon bond formed. The response is in the equation below shown for an olefinic double bond:

+ C = C - > = Si-C-CH

Many of the known hydrosilation processes include application a platinum catalyst in the form of a halogenated platinum compound or of finely divided platinum metal. So will U.S. Patent 2,823,218, for example, uses chloroplatinic acid as a platinum catalyst. According to the other method of the US patent 2,970,150 uses platinum metal on a finely divided carrier such as activated carbon. Further procedures are in U.S. Patents 3,159,601, 3,159,662 and 3,220,972.

Although the platinum catalyzed hydrosilation processes described above produce useful results, the amounts of platinum metal in parts by weight per million parts by weight of the hydrosilation mixture required to produce useful results are often such that these processes become economically unattractive. In many cases, for example, significant amounts of the platinum metal become catalytically inactive after recovery. The loss of a patient can be made more difficult by the fact that it is sometimes extraordinarily large. _S are quantities of platinum catalyst required to achieve desired speeds to obtain for the hydrosilation. However, in some special cases it has been found that the rate of hydrosilation is reduced when the known platinum catalysts are used above normal catalyst weight proportions.

Therefore, prior to the present invention, the platinum-Hydraulic _o led silierungaverfahren often the loss of undesirably large amounts of platinum metal. In addition, the limited hardening speed _{s limited the}

30S834 / 10S1,

Catalysts could be obtained, often the expansion of the Hydrosilation as a curing process for organopolysiloxane compositions.

The present invention is based on the discovery that considerably improved hydrosilation is possible by using the certain platinum-siloxane complexes defined below are used. These platinum-siloxane complexes have available inorganic Halogen in an amount less than 0.1 gram atom of halogen per gram atom of platinum, and they are preferably essential free of halogen and have a value of up to about 1. The known platinum halides, which were previously used as hydrosilation catalysts have available inorganic halide up to an average ratio of gram atoms Halogen per gram atom of platinum, which has a value of at least about 2.

In order to prepare the platinum-siloxane complexes of the present invention, it has been found to have (A) a platinum halide and (B) a Complex-forming material in the form of an unsaturated organosilicon material to use which is selected from

(a) unsaturated silanes of the formula

(b) unsaturated siloxanes of the formula

^{(2) R} c ^R d ^SiO (4-cd)

wherein R has no aliphatically unsaturated bonds and is selected from monovalent hydrocarbon radicals and R 'is selected from monovalent aliphatically unsaturated hydrocarbon radicals, X is a hydrolyzable radical, a is an integer from 0 up to and including 2, b is an integer from 1 to 4 inclusive, the sum of a and b has one Value from 1 to 4 inclusive, c has a word from O to a

309-834 / 1051

finally 2, d has a value from 0.0002 up to and including 3 and the sum of c and d has a value from 1 to 3 inclusive.

Although platinum metal as a catalyst for "SiH-olefin addition reactions can be used, it was found that .that it is advantageous to complex the platinum with another compound in order to make a more effective catalyst to obtain. Only halogenated platinum complexes are available for purchase. Therefore, in order to make the various platinum complexes, it is necessary to use platinum in a form which is sufficiently reactive. It is therefore necessary to use the commercially available halogenated platinum complexes, in which the platinum has the necessary reactivity to produce the other platinum complexes therefrom, which are considered more reactive were determined.

In U.S. Patents 3,419,593 and 3,474,123 are methods described for the production of a platinum complex, according to which a halogenated platinum complex with an unsaturated silane or Siloxane is implemented. The advantages of the complex obtained are pointed out in US Pat. No. 3,419,593, which is more effective or more reactive than the one made of platinum on activated carbon or chloroplatinic acid appears to be the existing catalyst. While that statement may be true, the one after this one is However, the catalyst obtained in the patent specification still has deficiencies in its reactivity.

In the present invention it was surprisingly found that the presence of halogen in a platinum catalyst made from a halogenated platinum complex and an unsaturated silane or siloxane, the The effectiveness of the catalyst is seriously compromised and that it is desirable to have most, if not all, of the halogen 'remove the complex. It should be noted that halogen will necessarily be present in the complex as one

309834/1051

of the reactants that are used to prepare the complex according to the both of the aforementioned US patents or na ± i of the present invention, the commercially available halogenated one Is platinum complex. The finding, however, that to use a platinum complex catalyst of the highest efficiency and reactivity to obtain most, if not all of the halogen from the platinum-unsaturated siloxane catalyst of the present invention must be removed, however, is based on the present invention. This therefore creates a new and unexpected one Platinum complex catalyst, the more effective and reactive is known as the platinum complex catalysts described in U.S. Patents 3,419,593 and 3,474,123.

The present invention provides a platinum complex catalyst which is low in halogen, if any, and which is extremely effective and reactive and is the most effective catalyst useful for SiH olefin addition reactions. Until the invention, the effect of halogen on a platinum catalyst had not been recognized. Due to the fact that chloroplatinic acid was more reactive than elemental platinum, it was concluded that halogen had no effect or an improving effect on the reactivity of the platinum metal. It has been found in the present invention that the actual catalyst is the platinum ion and that the presence of halogen ions seriously affects the effectiveness of the platinum ion. The two aforementioned US patents also contain the assumption that halogen has no effect or promotes the catalytic activity of the platinum ion. Therefore, up to now, attempts have been made to 'platinum com-'. To produce ρlex catalysts that had high halogen contents. Before the invention it was not recognized that a platinum complex catalyst should contain as little halogen as possible.

The platinum-siloxane complexes of the present invention can be prepared as follows:

309834/1051

(1), By bringing an unsaturated organosilicon material defined by the formulas (1) and (2) into contact with a Platinum halide for the preparation of a mixture containing a certain concentration of available inorganic halogen,

(2) Treating the mixture obtained in (1) to make the available remove inorganic halogen and

(3) Isolation of a platinum-siloxane complex from the according to (2) obtained mixture, the available inorganic halogen of has less than 0.1 gram atom of halogen per gram atom of platinum and which is preferably substantially free of halogen.

To the extent that the term "available inorganic halogen "is used, it is intended to mean a halogen produced by a modification of the ASTM determination method D-I821-63 for inorganic chloride can be displayed. The procedure used for this is essential the same as described except that instead of -acetone used in the above determination method as a solvent is used, a mixture of glacial acetic acid and acetone is used here. The method used to determine the Gram atoms of platinum in the platinum-siloxane complexes was atomic absorption spectroscopy, such as the method of R. Dockyer and G.E. Harnes in the journal "Analyst", Volume 84, p (1959).

Preferably the platinum-siloxane complexes consist of the present Invention essentially of chemically bonded platinum and organosiloxane of the formula

!; ⁽³⁾ ' ^R e ^Rt f ^R V ⁱ⁰ (4-efg)

'2

! wherein the organosiloxane substantially with each other ^chemically: the combined siloxy units is selected from

309834/1051

"- 7 ■ ·

(d) Mixtures of (c) and R ^ut -.SiO./.^._. χ,

where'R and R ^{1 have} the abovementioned meaning, R "is selected from the radicals for R 'which are chemically bonded to platinum and R"' is selected from the radicals R ¹ and R ", e has a value of O up to and including 2, f has a value from O up to and including 2 and g has a value from 0.0002 up to and including 3 and the sum of e, f and g has a value from 1 up to and including 3 _S h is an integer from 1 up to and including 3 and j is an integer from 0 to 3 · ■ inclusive

The platinum-siloxane complexes of platinum and Organosxloxanes of formula (3) can be prepared according to the present invention as described above by a platinum halide and either an unsaturated silane of the formula (1) or an unsaturated siloxane of the formula

(4) R _k R

used, the at least one structural unit of the formula

R ¹ R

= Si 0 Si =

contains, where the unsaturated valences of the above structural unit ^{can be saturated by R, R 1} and oxygen radicals, where R and R ^! have the preceding meaning, k has a value from 0 to 2 inclusive, m has a value from 0.0002 to 3 inclusive and the sum of k and m has a value from 1 to 3 inclusive. ■ · ·

The radicals encompassed by R can be, for example, the following: alkyl radicals, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, etc .; Cycloalkyl groups such as cyclohexyl, cycloheptyl, etc .;

309834/1051

• - 8 - ■

Aryl radicals such as phenyl, tolyI ₅ xylyl, etc .; Aralkyl radicals such as _: benzyl, phenylethyl, phenylpropyl, etc .; The radicals which can stand for R 'are, for example, the following: aliphatically unsaturated radicals _s such as ethynyl, 1-propynyl, etc., 5 vinyl, allyl and cycloalkenyl radicals, such as cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, etc. For R "can all of the aforementioned radicals stand for R 'which form complexes with platinum; radicals for R "' can be all of the ^{radicals mentioned for R 1} and R". In the above formulas in which R _{3 is} R ', R "and R"' more as a radical, all of these radicals can be the same or two or more of the aforementioned radicals.

It is desirable that neither R nor R ¹ contain chemically bonded halogen, since the presence of such hydrocarbon-bonded halogen in the platinum complex adversely affects the catalytic action of the complex. Accordingly, those silanes and siloxanes of the formulas (1) and (2) which do not contain chemically bonded halogen are preferably used to form the platinum catalyst of the present invention ) and (2) are used which have halogen-containing hydrocarbon radicals ^ then most of the halogen can be removed by a method which is described in more detail below _{9 to} obtain a platinum catalyst which, in accordance with the present description, has a low halogen content.

Unsaturated silanes which are included in the formula (1) are, for example, tetravinylsilane, triallylmethylsilane, divinyldimethylsilane, Trivinylphenylsilane, divinylmethylphenylsilane, divinylmethylethoxysilane, Divinyl methylacetoxysilane, etc..

From the formula (2), for example, the unsaturated siloxanes are Disiloxanes of the formula

(5). lyt ^^

309834 / 10S1

comprises, wherein R, R ¹ , a and h have the abovementioned meaning ■■ and the sum of a and h per silicon atom is the same. 3 is. ^Examples: games of compounds of disiloxanes of the formula (5): sym-divinyltetramethyldisiloxane, 1,1-divinyltetramethyldisiloxane, hexavinyldisiloxane, 1,1,3-Trivinyltri'methyldisiloxan, sym-tetravinyldimethyldisiloxane, etc.

The formula (2) for the unsaturated siloxanes also includes cyclopolysiloxanes including chemically combined units the formula

R ¹ O R ' X Y O Si Si -Si t I. I. Y Y Y

wherein R ^{1 has} the above meaning, Y is selected from R and R ¹ , χ is an integer from 1 to 9 inclusive, ζ is an integer from O to 17 inclusive and the sum of χ and ζ is 2 to 17 inclusive Examples of such compounds are: 1,3> 5-Ti * ivinyl-1,3,5-trimethylcyclotrisiloxane, 1 * 3s 5 » 7-tetraally1-1,3,5 » 7-tetraphenylcyclotetrasiloxane, 1,3-divinyloctamethylcyclopentasiloxane, etc. .

The platinum halides which can be used in the context of the present invention are, for example, H ₀ PtCl ₄ - * H ₀ O and their Me-.

³ 2 ο η 2

tall salts, such as NaHPtCl, - · H ₀ O, KHPtCl, - * H ₀ O, NaJPtCl ^ * H ₀ O,

on2 ο η 2 d ο η d

PtCl ₂₁ -H ₂ O and platinum halides, such as PtCl ₂ , H ₂ PtCl ₂ ^ _n H ₀ O, NaHPtCl ₁ ^ _n H ₂ O, KHPtCl ^ '^ O, K ₃ PtBr ^., Can also be used.

Platinum halide complexes with aliphatic hydrocarbons, as described in US Pat. Nos. 3,159,601 and 3,159,662, for example the compounds F (CH ₂ = CH ₂ ) 'PtCl (PtClp * C, Hg) ₂ etc. used

309834/1051

- IQ -

are described in US Pat. No. 3,220,972, like ζ.Β- the reaction product of chloroplatinic acid hexahydrate and octyl alcohol etc. '

In addition to the platinum-siloxane complexes described above, the invention also relates to curable organopolysiloxane compositions Settlements of at least 0.01 part and preferably 1 to 200 Parts of platinum per million parts of the 'organopolysiloxane, da's (C) an organopolysiloxane of the formula

(6) RiV

and (D) the platinum-siloxane complex as described above is and preferably such a platinum-siloxane complex, which consists essentially of chemically bonded Platinum and an organosiloxane of the formula

RR 'R "SiO ,,. Ν
η ρ q (4-npq)

consists, this organosiloxane falling within the scope of formula (3) and essentially from 2 to 500 chemically with one another combined units that are selected from

(e) R '" _h Si0 ₍₄ " _h) ,

2
and

(f) mixtures of (e) and R " ¹ .SiO ^ .ν,

wherein R, R ¹ , R ", c, e, f, g, h and j have the above meaning, R ^{1V is} selected from the radicals for R and cyanoalkyl radicals, η has a value from 0 to 2 inclusive, ρ has a value from 0 up to and including 2, q has a value from 0.004 up to and including 2, the sum of n _s ρ and q is 1 up to and including 3, and t has a value from 0.001 up to and including 1.

The significant difference between the platinum-siloxane according to the invention

309834/1051

Complexes with respect to the known platinum halides are that less detectable inorganic halogen is present in the platinum-siloxane complex according to the invention. Suggest the Versuchs.ergebnisse that the platinum is chemically bonded to the unsaturated siloxane of at least three ^Ä SiR' units per gram atom of platinum, where R 'has the meaning given above. In any case, in contrast to the known platinum halides, the platinum-siloxane complexes according to the invention can be completely free of available inorganic or displayable inorganic halogen. In those cases in which available inorganic halogen is determined in the platinum-siloxane complexes according to the invention, the amount of this available inorganic halogen should not exceed 0.1 gram atom of halogen per gram atom of platinum and preferably the complex according to the invention is essentially free of halogen. Otherwise the activity of the platinum-siloxane complex obtained would be adversely affected. The platinum-siloxane complexes according to the invention are stable for a long time, for example for 6 months or more at temperatures between -50 and +50 C. In some cases it is advantageous to protect the platinum-siloxane complexes from atmospheric moisture.

The platinum-containing organopolysiloxane compositions that contain a Organopolysiloxane polymer of formula (6) and the platinum-siloxane complex of the present invention can be made using a variety of silicon hydrides by hardening in transferred to the solid state. Silicon hydrides which can be used for this purpose are, for example, organocyclopolysiloxanes, which contain at least two contain chemically linked RHSiO units and organopolysiloxane polymers, re, which are chemically linked together

(R) Si (H) O units, where R ' a q

have mentioned meaning and q is 1 or 2.

The organopolysiloxane polymers of the formula (6) can chemically have related units of the following formulas:

309834/1051

where R and j have the aforementioned meaning and s is an ^x integer from 1 to 3 inclusive. The organopolysiloxanes of formula (6) include liquids, rubbery compounds and resins, depending on the ratio of the R radicals ^lv .to the Siliciumatomen..Die platinum-containing organopolysiloxane compositions of the present invention which are curable by reaction with the above-mentioned silicon hydrides can be used for a wide variety of applications. They can be used to encapsulate electronic components, where the organopolysiloxane of the formula (6) can be an organopolysiloxane liquid with dior.gano.alkenylsiloxy end groups.

such as dimethylvinylsiloxy units, units, / wherein the liquid has a viscosity of at least 500 centipoise at 25 ° C. Organopolysiloxane rubbers can also be used having a viscosity of at least 100,000 gentipoise at 25 ° C, which are chemically linked together Having methylvinylsiloxy units, etc., for production elastomeric compositions, etc. serve. The platinum haMge The organopolysiloxane of the present invention may also contain 10 to 300 parts of filler per 100 parts of the organopolysiloxane contain. Useful fillers are silica such as fumed silica or non-reinforcing fillers such as Soot etc.

The platinum-siloxane complexes of the present invention can be prepared by blending the unsaturated organosilicon material with the platinum halide. The mixture obtained is then used to remove the available inorganic Treated with halogen. The platinum-siloxane complex is then isolated from the mixture and treated further to remove unwanted materials, how to remove raw materials and by-products.

Experiments have shown that useful results can be obtained if one is involved in the preparation of the platinum-siloxane complex having sufficient unsaturated organosilicon material

309834/1051

Regarding the platinum halide used to be at least 3 moles

atom
of ^s SiR 'units per gram / platinum. In the cases

in which an unsaturated siloxane is used with the structural unit R ¹ R ^1. , e.g. a disiloxane, then should be

= Si O Si =

ranging.of the unsaturated siloxane used to at least 3 moles of the structural unit per 2 gram atoms. Platinum ' to have. Experiments have further shown that the ratio of the unsaturated organosilicon material to the platinum halide however, it can be varied within wide limits. However, for economic reasons it has been found to be advantageous. to use an excess of unsaturated organosilicon material to avoid loss of platinum.

After the platinum halide and the unsaturated organosilicon material are mixed together, various methods can be used to prepare the platinum-siloxane complex, depending on the nature of the platinum halide and unsaturated organosilicon material used. For example, you can work at temperatures between -50 and +200 C, the preferred temperature range being between 0 and 100 ^° C. ·

When the platinum halide is in the form of a platinum-olefin complex is used, an instantaneous reaction can occur without the application of external heat. In some cases it can even external cooling may be required.

After the addition is complete, various methods can be used to remove the available inorganic halogen. To facilitate this removal, it has been found advantageous to have sufficient water in the mixture is present which, in terms of the number of moles, is at least equal should be the product of the number of gram atoms of platinum times its valence. However, tests have shown that in all Cases, if the water is not expressly excluded,

309834/1051

more than the minimum required amount of water in general is present in the mixture due to atmospheric moisture and the chemical with the reactants associated water or the water present in the solvents used to produce the platinum-siloxane complex.

A Method of Removing the Available Inorganic Halogen ' from the reaction mixture is a strip process in which the application of heat and reduced pressure, such as 10 mm or more, can be combined with the addition of the base. if however, if this procedure is to be used, it should be combined If a complex is to be obtained, the O bis are used with the base addition method explained below 2000 ppm halogen per part of platinum, with one such Platinum complex corresponds to the improvement according to the invention.

Another effective method of removing the available inorganic halogen is through the use of a base, which serves to neutralize the halogen acid that may be present in the mixture. Usable bases are e.g. alkali carbonates, such as sodium carbonate, potassium carbonate, sodium bicarbonate etc., Alkaline earth carbonates and bicarbonates, alkali hydroxides such as sodium hydroxide, potassium hydroxide, etc. The use of the base in a slight excess over the amount required to neutralize all of the available inorganic halogen Forming the corresponding salts leads to useful results. It can be less than a stoichiometric amount can be used, but at least an amount sufficient to remove so much of the available inorganic halogen allows the average ratio of gram atoms of halogen per gram atom of platinum in the above specified range according to the present invention falls.

The addition of a base is the basic procedure for removing halogen from the platinum complex and even if you use it alone used, it results in a platinum complex with less than

309834/1051

0.1 gram atom of halogen per gram atom of platinum and preferably to an essentially halogen-free complex. Other methods may be used in combination with the method of adding base like the heating and stripping mentioned above. Furthermore, absorbent substances can be added to the complex, such as molecular sieves to remove those formed after the addition of the base To absorb salts.

Another method that can be used in addition to the base addition to effect the removal of the available inorganic halogen, when using platinum halides that are insoluble in organic solvents, such as KpPtCl _2. , The use of certain catalysts, such as SnClp 'HpO. After the platinum-siloxane complex has been formed in an aqueous medium using this catalyst, the platinum-siloxane complex can be isolated by using a non-polar organic solvent, with the excess inorganic halogen remaining in the aqueous medium.

The use of an organic solvent has been found to be useful to prevent contact between the platinum halide and to facilitate the unsaturated organosilicon material in the initial admixture. In some cases, a Mixture of the organic solvent and water can be used, while in other cases the unsaturated organosilicon material itself can serve as a solvent. The type of solvent may vary depending on the type of solvent platinum halide used as well as the nature of the one used unsaturated organosilicon material. In general, however, hydrocarbon solvents can be used, such as aromatic hydrocarbons, alcohols, e.g. ethyl alcohol, as well as other low molecular weight aliphatic alcohols, ethers etc.

As a result of the treatment with the base to remove the inorganic halogen from the platinum-siloxane complex

309834/1051

230708S

various impurities such as salts, molecular sieves, etc. remain in the platinum-siloxane complex.-A suitable method removing unwanted materials is to remove the solvent from the reaction mixture by stripping and extracting the platinum-siloxane complex with a suitable solvent such as a non-polar hydrocarbon solvent and then filtering. In those cases where the unreacted organosilicon material is sufficient is volatile, this is often removed with the stripping. . .

It has been found that in most cases _Ä in which a platinum-siloxane complex is formed, new Infraröt absorption bands at 7 * 5 appear to 7.6 and 8.3 ^ microns. If unsaturated organosilane is used, the siloxane can be formed by hydrolysis of hydrolyzable radicals or by cleavage of R 'radicals from silicon if b in formula (1) is 2 or more. The aforementioned structural unit should preferably be present in the same molecule. In some cases, useful results have also been obtained with an unsaturated siloxane reactant in which only the end groups were unsaturated. - '

If a large excess of the unsaturated organosilicon material was used to produce the platinum-siloxane complex, which cannot be easily removed by stripping, then you can use the mixture of · platinum-siloxane complex and unsaturated Siloxane as inventive ρlatin-containing organopolysiloxane isolate. Curable organopolysiloxane compositions can also be made by mixing the platinum-siloxane complex with organopolysiloxanes of the formula (6). If the organopolysiloxane is rubbery, mixing of the Ingredients are made on the roller, it is a resin, then by using a solvent. Are organopolysiloxane and platinum-siloxane complex liquids, then bare can Mixing is sufficient. .

3D9834 / 1051

230708S

The invention is explained in more detail below with the aid of examples explained, in which all specified parts are parts by weight,

309834 / 10S1

- 18 example, 1

27.8 parts of 1,3-divinyltetramethyldisiloxane were added to 19.5 parts of OpH ^) ₂ . The mixture then became slow

pp ^ ₂

heated for one hour on .3O ⁰ C and held an additional hour at a temperature of 25 to 30 carbon with the aid of an ice bath. During this time, ethylene developed continuously, leaving a yellow-red liquid and an orange-colored plague body. Analysis of the product indicated that it contained a ratio of about 2 gram atoms: chlorine per gram atom of platinum.

Benzene was added to the obtained mixture and stirred for two hours. Thereafter, about 48 parts of ethyl alcohol, which contained about 4 1/2 % water, were added. An exothermic reaction occurred _; and the reaction mixture was cooled to maintain a temperature of 25-30 ° C. It became a yellow-red solution; obtained after the addition is complete. Finally, 12.5 parts of sodium bicarbonate were added to the mixture, a vigorous evolution of gas being observed. The addition of the sodium bicarbonate was slow to keep up with the rate of gas evolution. too massive. After stirring the mixture for one hour at room temperature, it was filtered. The solids were washed with a mixture of ethanol and benzene. The filtrate was freed from the volatile constituents by stripping in vacuo and a 95% yield of a yellow-red oil, based on the starting materials, was obtained. Analysis of the product by IR indicated that it was a 1,3-divinyltetramethyldisiloxane complex with a shift in the absorption band of the = CH bond of 10.5 microns and 10.7 microns. The analysis of the platinum - \ and inorganic chlorine showed a ratio of less than 0.1 chlorine atom per atom of platinum.

Example 2

Der.Platinsiloxankomplex of Example 1 was poises to an organopolysiloxane mixture having a viscosity of about 4000 centi- at 25 ⁰ C of polydimethylsiloxane added, the ^": 3 & 9834M0S1

2307088

Had dimethylvinylsiloxy end groups and contained a copolymer composed of chemically linked together
SiO ₂ units, (CH,) SiO _{0 5} units and (CH ₂ = CH) CH ^ SiO units, a platinum-containing organopolysiloxane composition being obtained which contains 2 parts of platinum per 1 million parts of the mixture; contained. Another platinum-containing organopolysiloxane compound; Settlement was made according to the present invention using the same process, adding 10 parts of platinum per:

Contained 1 million parts of the organopolysiloxane. i

Using the same procedure, additional mixtures were made; made with known platinum halides to obtain mixtures containing both 2 and 10 parts of platinum per million parts of the organopolysiloxane. ^;

To 100 parts of each of the above-described ρlatin-containing organopolysiloxane mixtures, 10 parts of a copolymer were added which is composed of chemically interconnected SiOp units. and H (CH,) _o Sx0 units. Table j below shows the results that were obtained with the various platinum-containing organopolysiloxane mixtures, either of which:

Platin-SiIoxane complex according to the present invention contained j

(see Karstedt) or the well-known platinum halides. The i table shows the time in minutes that is required; to convert the mixture into a non-pourable one, namely j for the various platinum-containing organopolysiloxane compounds. |

Karstedt
1,5-hexadiene platinum dichloride

(CH = CH ₂ -PtCl ₂ ) ₂

TABEL ppm Pt. rid. CVl 10 Time (min) 210 16 1770 205 2840 568 1440 228 2880

309834 / 1Q51

This table shows that using the inventive Platinum-siloxane catalyst considerably

• improved curing times for the curable organopolysiloxane mixtures are obtained. The above values further demonstrate the considerable advantages associated with using the platinum ■. containing organopolysiloxane compositions of the present invention are connected, which can be cured at considerably greater speeds with the same amount of platinum, compared with the known platinum-containing organopolysiloxane additives; compositions ·. These advantages are made particularly clear by "a comparison of the times which are required until the non-flowable state is reached, and which is approximately the same when using 2 parts of the catalyst according to the invention as that using 10 parts of 1.5 -; hexadiene platinum dichloride catalyst. |

Example 3

Sufficient sodium bicarbonate is added to a mixture of 25 parts of Na ₂ PtCl ^ 4H ₂ O, 50 parts of 1,3-tetramethyldisiloxane and 125 parts of ethyl alcohol that a mixture is obtained which has an available inorganic chlorine content of less than 0, 1 chlorine atom per platinum atom is. In addition, a mixture of the type mentioned above is produced which does not contain sodium bicarbonate.

The above mixtures were heated to a temperature between 70 and 75 ° C for 5 minutes. The pest substances were made with ethyl

this
alcohol washed and combined with the appropriate filtrates.

The analysis for available inorganic halogen using the modified ASTM determination method D-1821-63 for inorganic Chloride found mixture 1 heated with sodium bicarbonate to have an average ratio of 0.05 gram atoms Chlorine per gram atom of platinum. The untreated mixture had an average ratio of 2.2 gram atoms Chlorine per gram atom of platinum.

309834/1051

According to Example 2, platinum-containing organopolysiloxane · Mixtures made using the aforementioned Mixtures 1 and 2, each containing 10 parts of platinum per million

Contained parts of the mixture. The times required to reach the no longer flowable state of the mixture are in in the following table, the ratio Cl / Pt indicating the gram atoms of chlorine per gram atom of platinum.

Cl / Pt time (min)

0.05 135

2.2 315

Example 4

25 parts of sodium bicarbonate were made into a mixture of 25 parts Sodium chloroplatinite, 50 parts of 1,3-divinyltetramethyldisiloxane and 125 parts of ethyl alcohol are added. The mixture obtained was heated to a temperature between 70 and 75 ° C. for 15 minutes. Then one filtered and washed the plague with ethyl alcohol, which one combined with the piltrat. By stripping in a vacuum the volatile constituents were removed from the filtrate. The residue was dissolved in 25 parts of benzene, filtered and removed the volatile constituents again by stripping in vacuo. 35.6 parts of a red-brown transparent were obtained Oil.

The oil crystallized at -13 ° C. The IR spectrum showed the presence of a divinyltetramethyldisiloxane with a shift in the absorption of the = CH bond from 10.5 microns to 10.7 microns. There was also an absorption at 7.5 to 7.6 microns and 8.34 microns. Elemental analysis for platinum, carbon, hydrogen and silicon and the IR spectrum showed that the complex was three

OH ₃
OSi had CH = CH ₂ units chemically linked to each gram atom

CH ₃ -

309834/1051

- 22 platinum were connected. ^r

0.7 parts of the above crystalline platinum-siloxane complex were placed in a vacuum of 10 "Hg ~ The complex decomposed at 130 C. to yield 0.4 parts of the organosiloxanes of the 90 wt -.. 1.3% -Divinyltetramethyldisiloxane as could be determined by IR spectrum.

From the above results it can be seen that the obtained according to the invention Platinum-siloxane complex has a ratio of 3 moles of the structural unit

CH = CH ₂ CH = CH ₂
CH, Si-0 -SiCH, to 2 gram atoms of platinum, both

CH ₃ CH ₃ .

were chemically linked to one another via = SiC_H, bonds.

Example 5

Two parts! ^, S ^ -Tetramethyl-l ^ jS ^ -tetravinylcyclotetrasiloxane were added to a mixture of 2 parts of sodium chloroplatinite, 8 parts of ethyl alcohol and 2 parts of sodium bicarbonate. The mixture obtained was heated for 10 minutes to a temperature between 70 and 75 ^° C. The mixture was then flushed with nitrogen to remove volatile constituents and then 20 parts of benzene were added. A mixture of a yellow liquid and a plague was obtained . The mixture was filtered. Analysis for platinum and available inorganic chlorine showed a ratio of less than 0.1 gram atom of chlorine per gram atom of platinum. The IR spectrum showed absorption bands at 7.5 to 7.6 and 8.34 microns.

Example 6

20 parts of sodium bicarbonate were added to a mixture of 10 parts of H ₂ PtClg'6H ₂ O, 20 parts of 1,3-divinyltetramethyldisiloxane and 50 parts of ethyl alcohol. The mixture was stirred at reflux for 30 minutes and then left for 15 hours

309834/1051

stand still for a long time. The mixture was then filtered and removed the volatiles' by vacuum stripping. 17 parts of a liquid product were obtained. This was in Dissolved benzene and filtered. The product was a platinum-siloxane complex, which was essentially free of available inorganic chlorine as determined by analysis for inorganic chloride.

The above platinum-siloxane complex in benzene was converted into the polydi- ' methylsiloxane of Example 2 with dimethylvinylsiloxy end groups incorporated to form a platinum-containing organopolysiloxane with 10 To give parts of platinum per million parts of the mixture. After less than a minute, the mixture was no longer flowable. Similar mixtures containing known platinum (II) chlorides instead of the catalyst according to the invention remained for; several hours liquid.

Example 7

2 parts of sodium bicarbonate were added to a mixture of 2 parts of Na ₂ PtClj ₄ ^ H ₂ O, 2 parts of dimethyldivinylsilane and 8 parts of ethyl alcohol. An exothermic reaction took place with stirring and gas evolved. The mixture was then gently warmed for a minute and allowed to stand still for 10 minutes. The volatiles were removed from the mixture using a stream of nitrogen. Thereafter, 20 parts of benzene was added to the mixture and filtered. The filtrate was stripped from the organic solvent using nitrogen. A liquid was obtained which; was mixed with a solvent mixture of equal parts by weight of benzene and ethyl alcohol. Analysis of the mixture for available inorganic chlorine and platinum indicated a ratio of less than 0.1 gram atom of chlorine per gram atom of platinum. The infrared spectrum showed the presence of siloxane and it was identical to the infrared spectrum of the platinum-siloxane complex prepared according to Example 4.

309834/1051

- 2k -

The above procedure was repeated except that 6 parts of diphenyldivinylsilane were used in place of the dimethyldivinylsilane were used. Analysis of the product thus obtained showed a ratio of less than 0.1 gram atom of chlorine per Gram atom of platinum. The infrared spectrum of the product showed the Presence of disiloxane and absorption bands attributable to the bonding of phenyl radicals to silicon.

The platinum-siloxane complexes described above, which exhibited tetramethyldisiloxane and tetraphenyldisiloxane absorptions, were used as hydrosilation catalysts in a process similar to that described in Example 2. Thereby posed; it is found that the non-flowable state was reached in considerably less time than using ^;

at least

Platinum halides were possible, which had a ratio of'2 gram atoms Contained chlorine per gram atom of platinum.

Example 8

An organopolysiloxane polymer was prepared by the process described in US Pat. No. 3,105,061 by rapidly adding one mole of 1,3-diacetoxy-1,3-divinyl-1,3- & imethyldisiloxane to one mole of the sym-tetramethyldisiloxane. · -1 , 3-aiol added. ^: The mixture was allowed to stand under atmospheric conditions for 24 hours and then subjected to stripping. The preparation process resulted in a polymer having about 500 chemically linked siloxy units, including units of the formula

OTT / " ¹ TJ Λ * TJ Π U

I'll -, - ^ ** TP ^ ^ O "X

-Si - 0 - Si - 0 Si 0 Si

Cn-? CH, CH, ^ H,

Two parts of sodium bicarbonate were added to a mixture of ¹ J parts of the above organopolysiloxane, 2 parts of Na ₂ PtCl ₁ ^ H ₂ O and 8 parts of ethyl alcohol and 8 parts of benzene. They left the

309834/1051

2307088

Mix standing under atmospheric conditions for a week. Then it was subjected to vacuum stripping, mixed with benzene and filtered. A platinum-siloxane complex with an average ratio of less than 0.1 gram atom was obtained Chlorine per gram atom of platinum.

example $

A platinum-siloxane complex of Example 1 was made with a polyorganosiloxane mixed with a viscosity of about 5 million centipoises at 25 ° C, the polyorganosiloxane being composed was composed of chemically interconnected dirnethylsiloxy, methylcyanoethylsiloxy, methylvinylsiloxy units and as Has end groups dimethylvinylsiloxy units. The polymer contained about 0.2 mol / l methylvinylsiloxy units by weight to the entirety of the chemically linked siloxy units. The amount of the platinum-siloxane complex that is applied was sufficient to give an organopolysiloxane composition containing about 1 part of platinum per million parts of the composition contained. With 100 parts of this ρlatin-containing organopolysiloxane composition 0.15 part of tetramethylcyclotetrasiloxane was mixed. The obtained composition was then quickly transferred to a mold and heated in a press to about 150 C- (300 F) for 10 minutes. A cured elastomer was obtained with valuable properties.

Example 10

In a 3 liter flask was 268 g of sodium bicarbonate and

761 g of (CH, (CH ₀ = CH) Si O. The air in the flask

ι! ³ J2
was displaced by nitrogen and a solution of 190 g of H ₂ PtClg. 6H ₂ O in 38I g of ethyl alcohol was added at room temperature with thorough stirring of the contents of the bottle. The mixture was then heated ^{to 65 °} C. for 25 minutes while maintaining the protective nitrogen atmosphere. The temperature was then reduced to 40 ° C. and the volatile constituents were removed by stripping in vacuo

309834/1051

Temperature 40 to 45 C upright and stopped stripping at a temperature of 45 ° C and a pressure of 5 mmHg. After that there was 38I g of xylene were added to the residue and the slurry was filtered off Mix to remove the excess salts. The filtrate was a straw colored solution and a platinum complex that was 0.0027 Had gram atoms of total chlorine content per gram atom of platinum.

Example 11

A slurry of 45 g NaHCO ₃ and 740 g CH ₃ (CH ₂ = CH) SiO was made in a 3 liter flask. A solution of 37 g of H ₂ PtClg · 6Η _? 0 in 178 g of ethyl alcohol. The mixture was heated to 75 ° C. for one hour. The volatile constituents were then removed by stripping under vacuum. The residual paste obtained was extracted with 178 g of xylene and the salts were removed by filtration. The filtrate was a platinum complex with a total chloride content of 0.0094 gram atoms per gram atom of platinum.

Although the aforementioned examples were necessarily limited to only a few of the very numerous compounds falling within the scope of the present invention, it should be pointed out that the present invention is directed to a much more comprehensive group of platinum-siloxane complexes, which essentially consist of chemically bonded platinum and organosiloxanes of the formula 3 can exist, for example RR ¹ JEt "SiOSiR"R'-R, where R, R ¹ , R ", h, f and e have the meaning given above, the sum of h, f and e 'per silicon atom is equal to 3 and wherein the complexes have a content of available inorganic halogen such that the average ratio of the gram atoms of halogen per gram atom of platinum is less than 1. In addition, the present invention is also directed to a much broader group of platinum-containing organopolysiloxane compositions which contain the aforementioned platinum-siloxane complexes. and organopolysiloxanes of the form l 6 include.

309834/1051

The present invention is further directed to a process for the preparation of the above-described elatin-siloxane complexes, which are prepared by reacting unsaturated organosilicon material of formulas 1 and 2 with a platinum halide can, wherein the product obtained is to be treated according to the present invention.

309834/1051

Claims (9)

- 28 claims. ·. 1. Organopolysiloxane compositions containing platinum with at least 0.01 parts of platinum per 1 million parts of organopolysiloxane, characterized that they - (C) Organopolysiloxanes of the formula and . (D) comprise a platinum-siloxane complex consisting essentially of chemically bonded platinum and a Organosiloxane of the formula ^R n ^R 'p ^R " _q ^Si0 (4- _n -p- _q ) 2 ' consists, which essentially consists of 2 to 500 chemically with each other connected units that are selected from (a) R " _h SiO ^ _ _h) and (b) Mixtures of (a) and R '' '. SiO, j,. *, wherein the complex contains less than 0.1 gram atom of halogen per gram atom of platinum and R is free of aliphatically unsaturated Is bonds and is selected from monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, R 'is selected from monovalent aliphatically unsaturated ones Hydrocarbon radicals and halogenated monovalent aliphatically unsaturated hydrocarbon radicals, R "is a vinyl residue that is chemically bonded to platinum, 3 0 9834/1051 to cause the new IR absorption bands at 7.5 to 7> 6 and 8.3 ¹ J microns in the IR spectrum of the platinum-siloxane complex, R ^flt is selected from the radicals for R and R ', R is ^1V selected from the radicals for R and cyanoalkyl radicals, c has a value from 0 up to and including 2, t has a value from 0.001 up to and including 1, the sum of c and t is equal to 1 up to and including 3 » h is an integer from 1 to including 3, j is an integer from 0 up to and including 3, η has a value from 0 up to and including 2, ρ has a value from 0 up to and including 2 and q has a value from 0.004 up to and including 2 and the sum of η, ρ and q is equal to 1 up to and including 3 2. Composition according to claim 1, characterized in that the platinum-siloxane complex essentially from chemically with 1,3-divinyltetramethyldisiloxane and 1,3-divinyltetraphenyldisiloxane linked platinum. 3. Composition according to claim 1, characterized that the platinum-siloxane complex is that with methylvinylcyclotetrasiloxane. 4. Composition according to claim 1, characterized in that g e that it contains 1 to 200 parts of platinum per 1 million parts of the composition. 5. Composition according to claim 1, characterized in that the platinum siloxane in the essentially made of chemically linked platinum and the organosiloxane of the formula R _e R ' _f R " _h SiOSiR" _h R' _f R _e consists, where R is free of aliphatically unsaturated bonds and selected from monovalent hydrocarbon 309834/1051 residues and halogenated monovalent hydrocarbon residues, R 'is selected from monovalent aliphatically unsaturated hydrocarbon radicals and halogen-containing monovalent ones aliphatically unsaturated hydrocarbon radicals, R "is a vinyl residue that is chemically bonded to platinum, to a displacement of 10.5 to 10.7 microns in the outside the out-of-plane C-H bond of the 2Si-CH = CHp group in the IR spectrum of the platinum-siloxane complex to cause e has a value from 0 up to and including 2, f has a value from 0 up to and including 2, h is a integer from 1 to 3 inclusive and the sum of e, f and h per silicon atom is 3 6. Composition according to claim 1, characterized that the platinum-siloxane complex consists essentially of 1,3-divinyltetramethyldisiloxane complexed platinum. 7. Composition according to claim 1, characterized that it also contains a filler. 8. Composition according to claim 1, characterized that the aliphatically unsaturated siloxane has at least one structural unit of the following Contains formula R "R"
= Si - 0 - Si = where R "is a vinyl radical chemically bonded to platinum. 9. Organopolysiloxane compositions containing platinum with at least 0.01 part of platinum per million parts of organopolysiloxane, characterized', that they (C) Organopolysiloxanes of the formula 30 9 8 34/10 51 ^R c ^V t ^SiO (4-ct)
2 (D) a platinum-siloxane complex comprising essentially made of chemically linked platinum and an organosiloxane the formula ^R n ^R 'p ^R "c ^S1O Unp- _q ) consisting essentially of 2 to 500 chemically linked units selected from (a) R " _h SiO _{(1 |} _ _h) and (b) Mixtures of (a) and R '·'. SiO ^. ν, wherein the platinum complex is essentially halogen-free and R is free of aliphatically unsaturated bonds and selected from monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, R 'is selected from monovalent aliphatically unsaturated hydrocarbon radicals and halogenated monovalent aliphatically unsaturated hydrocarbon radicals, R "is a vinyl radical which chemically associated with the platinum to cause new IR absorption bands at 7.5 to 7.6 and 8.3 * 1 microns in the IR spectrum of the platinum-siloxane complex, R " ¹ is selected from the radicals for R and R ', R is selected from the radicals for R and cyanoalkyl radicals, c has a value from 0 up to and including 2, t has a value from 0.001 up to and including 1, the sum of c and t is equal to 1 up to and including 3 _} h is a integer from 1 up to and including 3> j is an integer from 0 up to and including 3, η has a value from 0 up to and including 2, ρ has a value from 0 up to and including 2, 309834/1051 • ■ - 32 - q has a value from 0.004 to exnschlxesslxch 2 and the The sum of η, ρ and q is equal to 1 up to and including 3 309834 /. 1051