JPH053343B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION Prior to the present invention, various platinum catalysts have been utilized for "hydrosilylation" of adding silicon hydrides to vinyl-substituted silicon materials. See, for example, Karstedt U.S. Pat.
No. 3775452 describes Pt with vinyl silicon siloxane ligands as active hydrosilylation catalysts.
(0) The use of complexes is indicated. Other platinum complexes, such as those with platinum halides, are shown in Ashby, US Pat. No. 3,159,601 and Lamoreaux, US Pat. No. 3,220,972.

Other hydrosilylation catalysts are shown in Fish, US Pat. No. 3,576,027.
Fissi produces platinum () catalysts by reacting chloroplatinic () acid crystals with organic silanes or siloxanes to produce stable and reactive platinum hydrosilylation catalysts.

Although the above-mentioned patents indicate that various platinum complexes are effective hydrosilylation catalysts, there is a continuing need for new platinum complexes that provide improved hydrosilylation rates.

The present invention provides that colloidal platinum complexes in the form of reaction products of silicon hydrides or siloxane hydrides with platinum(0) complexes or solutions of platinum() complexes in organic solvents provide excellent hydrosilylation rates. It's based on what you discover. In particular, it has been found that optimum catalytic activity is obtained if the reaction mixture is allowed to react for a sufficient period of time to form a colloid with a red to reddish-brown or black color.

SUMMARY OF THE INVENTION According to the present invention, (A) a reaction product of () a silicon hydride or a siloxane hydride, and () a platinum(0) or () complex, and (B) 2 to 1 part of (A). A colloidal hydrosilylation catalyst is provided which consists of ~20 parts by weight of an aprotic solvent and is used in (A) from 6 to 50 moles of ≡SiH per mole of Pt in ().

Platinum Pt that can be used in embodiments of the present invention
(0) and Pt() complexes include phosphine, halide, C _(1-8) alkyl group, C _(6-14) aryl group,
At least one ligand selected from the group consisting of C _(1-8) aliphatic unsaturated organic groups, nitriles and carbon monoxide is provided. Some of these platinum complexes are illustrated below.

(C ₈ H ₁₂ ) ₂ Pt, (where C ₈ H ₁₂ = 1,5-cyclooctadiene) (C ₈ H ₁₂ )PtCl ₂ , [(C ₂ H ₄ )PtCl ₂ ] ₂ , PtCl ₂ ( _{Hydrogenations that can be used in the practice of the present invention _} Some silicon or hydrogenated siloxanes are listed below.

(C ₂ H ₅ O) ₃ SiH, (C ₂ H ₅ ) ₃ SiH, [(CH ₃ ) ₃ SiO] ₂ Si(H)CH ₃ , Cl ₂ CH ₃ )SiH, and (CH ₃ ) ₂ C ₆ H ₅ SiH In the practice of the present invention, a platinum colloidal catalyst (hereinafter referred to as a colloidal catalyst) is first mixed with methylene chloride, tetrahydrofuran, benzene, xylene,
platinum(0) complex or platinum() in aprotic organic solvents such as toluene and diethyl ether.
Manufactured by dissolving the complex. Platinum complex solution with approximately 1-10 weight percent platinum at -10 °C
Mix with silicon hydride or siloxane hydride at a temperature of ~40°C. Generally, there is an induction period of 1 minute to 2 hours, after which reaction occurs between the platinum complex and the silicon hydride or siloxane hydride, as indicated by the liberation of hydrogen gas. Furthermore, a colored reaction product is formed, which is initially yellow and eventually becomes red, reddish-brown or dark red. The resulting colloid has platinum particles with an average diameter of 30-700 angstroms.

Further, the colloidal catalyst of the present invention has the formula (In the formula, R is a C _(1-14) monovalent hydrocarbon group or a substituted C _(1-14) monovalent hydrocarbon group, and R ¹ is a C _(1-10) olefinic unsaturated aliphatic group. group, a is an integer of 0 to 3 and preferably has an average value of 0.5 to 2, b is 0.005
2.0 and the sum of a and b is 0.8 to 3). The resulting mixture is stable at room temperature over long storage periods and has between 5 and 200 ppm platinum.

The olefinically unsaturated organopolysiloxanes include liquid organopolysiloxanes, which are preferably free of silane hydrogen and contain olefinic unsaturation due to double bonds between two adjacent aliphatic carbon atoms. . The group represented by R includes methyl,
Alkyl such as ethyl, propyl, isopropyl, butyl, octyl, dodecyl etc., cycloalkyl such as cyclopentyl, cyclohexyl, cycloheptyl etc., aryl such as phenyl, naphthyl, tolyl, xylyl etc., benzyl, phenylethyl, phenylpyropur etc. aralkyl, chloromethyl, trifluoromethyl,
There are halogenated derivatives of the above-mentioned groups such as chloropyropur, chlorophenyl, dibromophenyl, tetrachlorophenyl, difluorophenyl, etc., cyanoalkyls such as beta-cyanoethyl, gamma-cyanopropyl, beta-cyanopropyl, etc. Preferably R is methyl. moreover,
R may also be a mixture of the aforementioned groups.

Groups represented by R ¹ include alkenyls such as vinyl, allyl, methallyl, butenyl, pentyl, and the like. Preferably R ¹ is vinyl or allyl, most preferably R ¹ is vinyl.

The above-mentioned olefinically unsaturated organopolysiloxanes are well known in the art, as disclosed, inter alia, in US Pat. No. 3,344,111 (Chalk) and US Pat. Similarly, its manufacturing method and/or
Or the source is well known.

Examples of materials included within the scope of olefinically unsaturated organopolysiloxanes include vinylpentamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,1,3-trivinyltrimethyldisiloxane, 1,1 , 3,3-tetravinyldimethyldisiloxane, and high molecular weight polymers having 100,000 or more silicon atoms per molecule. The range of olefinically unsaturated organopolysiloxanes also includes methylvinylsiloxane (( _CH2 =CH)( _CH3 )SiO) or methylallylsiloxane (( _CH2 =CH- _CH2 )( _CH3 )SiO). Also included are cyclic materials containing silicon-bonded vinyl or allyl groups, such as cyclic trimers, tetramers or pentamers.

Among these cyclic substances, tetramethyltetraallylcyclotetrasiloxane and tetramethyltetravinylcyclotetrasiloxane are preferred.

A preferred class of vinylorganopolysiloxanes used in the practice of this invention are those set forth by Modic in US Pat. No. 3,436,366. These compositions are expressed by formula (1) (In the formula, R ² and R ³ are 1 containing no aliphatic unsaturation.
is a valent hydrocarbon group, at least 50 mole percent of the ^R groups are methyl, and n is about 50000 at 25°C.
~750000 centistokes, preferably around 50000
Liquid vinyl unstopped polysiloxane 100 with a viscosity of ~180,000 centistokes)
parts by weight, and (2) (R ⁴ ) ₃ an organopolysiloxane copolymer consisting of _0.5 units of SiO and ₂ units of SiO (in the formula R ⁴
is a group selected from the group consisting of a vinyl group and a monovalent hydrocarbon group not containing aliphatic unsaturation, and (R ⁴ ) ₃
The ratio of SiO _0.5 units to SiO ₂ units is about 0.5:1 to 1:1 and consists of 20 to 50 parts by weight (with about 2.5 to 10 mole percent of silicon atoms containing silicon-bonded vinyl groups).

In the liquid vinyl unterminated organopolysiloxane component, the monovalent hydrocarbon groups represented by R ² and R ³ are alkyl groups such as methyl, ethyl, propyl, butyl, and octyl, aryl groups such as phenyl, tolyl, and xylyl, and cyclohexyl. , cycloalkyl groups such as cycloheptyl, and aralkyl groups such as benzyl and phenylethyl. Preferably, all groups represented by R ² and R ³ are selected from the group consisting of methyl and phenyl groups, most preferably R ² and
R ³ is methyl. In the organopolysiloxane copolymer component, R ⁴ is a monovalent hydrocarbon group containing no vinyl and/or aliphatic unsaturation ^;
At least the aforementioned proportion of the radicals are vinyl. The non-vinyl R ⁴ group is selected from the R ² and R ³ groups and is preferably methyl.

The organohydrogenpolysiloxane contained in the silicon hydride mentioned above preferably includes a wide range of liquid organopolysiloxanes having silane hydrogen and no olefinic unsaturation. These organohydrogen polysiloxanes are also well known in the art, as shown in US Pat. No. 3,344,111 (chalk) and No. 3,436,366.

In addition to silicon hydride or siloxane hydride,
1,3-dimethyldisiloxane, 1,1,3,3
-Tetramethyldisiloxane, per molecule
There are high molecular weight polymers with 100,000 or more silicon atoms. Formula, ( _{CH 3} SiHO)
Also included are cyclic materials, such as cyclic polymers of methylhydrogensiloxane having the following:

Hydrogenated siloxane is also a hydrogenated siloxane unit
HSiO _1.5 , methylhydrogen siloxane unit CH ₃ (H)
It may contain siloxane units such as SiO, dimethylhydrogen siloxane units and dihydrogen siloxane units (H ₂ SiO). These copolymers contain from 0.5 to 99.5 mole percent of siloxane units having at least one hydrogen containing a mixture of silicon-bonded hydrogen and R groups (R) _a SiO units chemically bonded
99.5 mole percent.

The following examples are given by way of illustration and are not intended to limit the invention. All parts are by weight.

Example 1 0.1 ml of a xylene solution of a platinum vinyl siloxane catalyst (Karl Schutet) containing 5% by weight of platinum 50 microliters of hetriethoxysilane were added. The resulting mixture has a 10 molar excess of silane. An exothermic reaction occurred within 15 minutes at 25°C. The resulting clear solution was initially orange and turned black. Based on the manufacturing method, a colloidal platinum catalyst was obtained having about 3% by weight platinum and an average particle size of about 40 angstroms. The solution was stored in a -20°C freezer.

6 g of dimethylvinylsiloxy unterminated methylvinylsiloxane with an average of 1.65 wt% silicon-bonded vinyl groups and a viscosity of 500 centipoise at 25°C, silicon hydride containing 0.8 wt% hydrogen and a viscosity of 50 centipoise 0.67 g of siloxane and 10 ppm of platinum hydrosilylation catalyst were mixed. The hydrosilylation catalyst used was either the above-mentioned platinum vinyl siloxane (Karl Schutet) or the platinum colloidal catalyst (Colloid) of the present invention.The results are shown below, and the gelation time is the average of three measurements at 25°C. It is based on

Karl Schutets Colloid Gel Time (min) 21.1 8.5 These results demonstrate that the colloidal catalyst of the present invention is superior to conventional platinum(0) catalysts.

Example 2 A mixture of 6 g of a vinylsiloxane oil terminated with dimethylvinylsiloxy units having a viscosity of 400 centipoise at 25°C and 100 ppm of the colloidal platinum catalyst of Example 1 was stored at 25°C for 3 months. Gel time was determined by adding 1 part of silicon hydride crosslinker to 9 parts of platinum-containing vinyl silicone oil. No loss in activity was observed compared to the results shown in Example 1.

A mixture was prepared by mixing 10 ppm platinum of the above colloidal catalyst and several 6 g samples of the vinyl silicone oil of Example 1. These mixtures were stored at 60°C for 35 days. When a silicon hydride crosslinker is added to this platinum-containing vinyl silicone oil,
The resulting mixture was found to gel in 1.2 minutes. The same procedure was repeated except that 10 ppm of Karl Shuttetz catalyst was used. A gelation time of 2.1 minutes was observed.

These results demonstrate that the colloidal platinum catalysts of the present invention form stable mixtures with vinyl silicone oils that exhibit superior gelation times compared to conventional platinum catalysts after significant storage periods at ambient temperatures. It shows that it can be used.

Example 3 The colloidal platinum catalyst of Example 1 with a platinum content of 10 ppm was combined with 100 parts of vinyl-containing polydimethylsiloxane rubber reinforced with 35 parts of silica filler treated with hexamethyldisilazane and containing an average of 0.9% by weight of hydrogen25
A thermoset mixture was prepared by blending with 10 parts of a methylhydrogen siloxane fluid having a viscosity of 20 centipoise at °C. The ingredients were stirred together, placed in a mold and subjected to 10 tons of pressure for 45 minutes at 126°C. A cured silicone rubber was obtained with a hardness (Shore A) of 34, an elongation (percentage) of 536, and a tensile strength (PSi) of 753. These properties are significantly greater than that of the corresponding silicone rubber produced following a similar procedure using the prior art Karlshuttet catalyst in Example 1 and having an elongation (percentage) of 504 and a tensile strength (PSi) of 637. It is excellent.

Example 4 Cyclooctadiene platinum dichloride complex 0.06
g methylene chloride solution 2 ml hetriethoxysilane
Added 0.2ml. The resulting mixture turned yellow in 1 hour, then red in 2 hours. Hydrogen was continuously evolved during these 2 hours. Based on the manufacturing process, a colloidal platinum catalyst solution containing approximately 1% by weight platinum and an average particle size of 30 angstroms was obtained.

6 g of a polydimethylsiloxane solution terminated with dimethylvinylsiloxy units and having an average of 3 mol% chemically bonded vinylsiloxy units and a viscosity of 400 centipoise and an average of 0.8% by weight of silicon-bonded hydrogen at 25°C. 10 ppm of platinum catalyst was added to a mixture of 0.67 g of methylhydrogensiloxane having a viscosity of 50 centipoise and consisting essentially of chemically bonded methylhydrogensiloxy and dimethylsiloxy units. The following results were obtained at 25°C, and in the table, "colloid" refers to the platinum catalyst of the present invention, CODPt
_Cl2 is a conventional cyclooctadiene platinum dichloride catalyst.

Colloidal CODPt Cl ₂ Gelation Time (min) 29.5 121 The above results show that the colloidal catalyst of the present invention is superior to the conventional cyclooctadiene platinum dichloride catalyst. Furthermore, it has been found that if the platinum colloidal catalyst of the present invention is not placed at -20 DEG C., a decrease in catalytic activity occurs after about 5 days at room temperature.

Example 5 The activity of the colloidal catalyst prepared according to Example 1 and the platinum catalyst shown in Example 1 of U.S. Pat. No. 3,576,027 to Fisch was compared. Several crystals of chloroplatinic acid (0.0298
g, 39% Pt, H ₂ PtCl ₆ .XH ₂ O) was added to the reaction vessel, and 1.1 g of methyldichlorosilane was poured onto the crystals in the vessel. The reaction took place under a nitrogen atmosphere, resulting in the evolution of gas. The mixture turned pale yellow after about 3 hours at room temperature. After 5 hours, gas evolution stopped.

10 ppm of platinum catalyst was added to a hydrosilylation mixture of 1 part triethoxysilane and 1 part trimethylvinylsilane. The “colloidal” catalyst of Example 1 was 5
100% conversion of the hydrosilylation mixture was achieved within minutes. The Fitzsch catalyst had a conversion rate of less than 5% even after about 8 hours, while the use of the chloroplatinic acid isopropanol catalyst had almost quantitative conversion after about 8 hours.

After the initial production, the Fissu catalyst was allowed to stand at 25°C for 2 days for further evaluation. This turned into a deep red color. After about 90 minutes, 80% conversion of the hydrosilylation mixture was observed.

The reason why the activity of the fish catalyst is reduced compared to the colloidal catalyst of the present invention is that the fish catalyst is derived from a platinum () complex such as chloroplatinic acid, rather than platinum (0) or a platinum () complex. it is conceivable that. This is Pt(0) or Pt()
We show that colloids formed from the complexes can provide increased hydrosilylation activity compared to conventional platinum catalysts.

Although the examples described above relate to only a few of the numerous variations that can be used in the practice of the present invention, the present invention utilizes a wide range of platinum(0) and platinum() catalysts, as well as colloidal platinum catalysts such as Of course, there is a wide variety of silicon hydrides or siloxane hydrides used to form the hydrides.

Claims (1)

[Claims] 1 (A) () Silicon hydride or siloxane hydride and () Platinum Pt(0) or Pt() complex (However, ≡SiH6 in () for 1 mole of platinum in ()) and (B) a colloidal hydrosilylation catalyst consisting of 2 to 20 parts by weight of an aprotic solvent per part of (A). 2. The colloidal catalyst according to claim 1, which is obtained by reacting a platinum(0) complex with silicon hydride or siloxane hydride. 3. The colloidal catalyst according to claim 1, which is obtained by reacting silicon hydride or siloxane hydride with a platinum complex. 4. The colloidal catalyst according to claim 1, which is obtained by the reaction of silicon hydride or siloxane hydride with a platinum(0) complex having a vinylsiloxane ligand. 5 formula (In the formula, R is selected from a C _(1-14) monovalent hydrocarbon group and a substituted C _(1-14) monovalent hydrocarbon group, and R ¹ is
C _(1-10) olefinic unsaturated aliphatic group, a is 0-
3 and b has an average value of 0.005 to 2.0). Colloidal catalyst. 6 The olefinic unsaturated organopolysiloxane is vinylsiloxane, Pt(0) or Pt()
The complex is selected from the group consisting of phosphine, halide, C _(1-8) alkyl group, C _(6-14) aryl group, C _(1-8) aliphatically unsaturated organic group, cyanide and carbon monoxide. 6. A colloidal catalyst according to claim 5, having at least one ligand. 7. Colloidal catalyst according to claim 1, used for carrying out the reaction between silicon hydride and vinylsiloxane. 8 Pt(0) or Pt() complexes are phosphine, halides, C _(1-8) alkyl groups, C _(6-14) aryl groups, C _(1-8) aliphatic unsaturated organic groups, cyanides and At least one selected from the group consisting of carbon monoxide
8. A colloidal catalyst according to claim 7, having two ligands. 9. The colloidal catalyst according to claim 7, wherein the silicon hydride is ethoxysilane.