DE102010001071A1 - Tetraaminodisiloxanes and polyamides prepared therewith - Google Patents

Abstract

Tetraaminodisiloxane of the following formula (I) with R1, R2, identical or different, selected from the group of linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals, and R3, R4, R5, R6, identically or differently selected from the group Group H, linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals, halogens and pseudohalogens and polyimides prepared therewith.

Description

State of the art

In the field of high-performance polymers, polyimides are known as special polymers for various applications which require very good temperature stability. They also have good mechanical properties and are chemically resistant and resistant to oxidation. In general, polyimides having high thermal resistance are prepared in two stages from an aromatic diamine and an aromatic dianhydride as a powder. In the first stage, the addition of the diamines with tetracarboxylic dianhydrides leads to polyamide-polycarboxylic acids which are soluble in dipolar aprotic solvents and in a second step cyclize with intramolecular dehydrogenation to give mostly insoluble polyimides.

The thermoplastic processability of the polyimides depends strongly on two parameters: the structure of the polymer chains and the molecular weight. Some polyimides, especially homopolymeric polyimides, have very high thermal stability and good mechanical properties. However, these polyimides have the disadvantage that they can not be processed as thermoplastics, because for polyimides with high molecular symmetry, the melting temperature is above its decomposition temperature. For this reason, thermoplastically processable materials are produced as copolymers. The copolymer-based polyimides allow thermoplastic processing, but strict adherence to the stoichiometry of the educts for a suitable property profile of the polymers is indispensable. Therefore, the reaction conditions must be strictly controlled to reproducibly obtain the composition and properties of the material.

From a certain molecular weight, it is no longer possible, even in the case of the copolymers, to process these polyimides from the melt. For this reason, it is attempted to control and limit the molecular weight by using monofunctional end groups. Although this method is well established and considered simple, the use of monofunctional end groups has a detrimental effect on the mechanical properties of the polymers. The monofunctional end groups can lead to a broader molecular weight distribution and to the presence of oligomers in the material, which can have a negative impact on the mechanical properties of the material and thus limit the use of the polyimides as materials.

Disclosure of the invention

mit R₁, R₂ gleich oder verschieden, ausgewählt aus der Gruppe der linearen, verzweigten oder cyclischen Alkylreste, Alkenylreste, Alkinylreste, Arylreste, Heteroarylreste,
und R₃, R₄, R₅, R₆ gleich oder verschieden, ausgewählt aus der Gruppe H, der linearen, verzweigten oder cyclischen Alkylreste, Alkenylreste, Alkinylreste, Arylreste, Heteroarylreste, Halogene und Pseudohalogene.Item of the present invention is a tetraaminodisiloxane of the following formula (I)

with R ₁ , R _2, identical or different, selected from the group of the linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals,
and R ₃ , R ₄ , R ₅ , R _6, identically or differently, are selected from the group consisting of H, linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals, halogens and pseudohalogens.

At the heart of the invention are novel tetraaminodisiloxanes for the production of novel thermoplastic polyimide-based plastics with high thermal resistance, which can be processed by means of extrusion or injection molding. In this context, the selection and provision of the new starting materials makes it possible to influence the property profile of the thermoplastics, in particular with regard to the mechanical and thermal properties. The resulting thermoplastic polyimide-based plastics can have a melting temperature in the range of 300 ° C-400 ° C as well have a decomposition temperature above 400 ° C. Furthermore, these materials are resistant to solvents and oxidation.

The new tetraaminodisiloxanes and the polyimides obtainable from them fulfill the abovementioned property profile well. Furthermore, the tetraaminodisiloxanes have the advantage that they can synthesize the polyimides as homopolymers with correspondingly preferred tetracarboxylic dianhydrides. Thus, the use of monofunctional end groups for thermoplastic processability of the polyimides is not needed. Deterioration of the mechanical properties due to remaining monofunctional monomers or oligomers occurring thereby is effectively prevented.

By incorporating disiloxane units of the tetraaminodisiloxanes according to the invention, polyimides are prepared for the first time as so-called conductor polymers. In these two linear molecular chains are connected at defined distances by Si-O-Si "rungs". Due to their structure, they are particularly resistant: If a chain strand breaks, the chain is still held together by the second strand. In particular, with regard to a high thermal stability can be stated in ladder polymers that takes place only at very high temperatures degradation of the molecular chains. This has the background that it is normal for z. B. due to heat to chain scission occurs, which leads quickly to a significant deterioration of the mechanical properties. In the case of a ladder polymer, however, both connected chain strands must be split at one and the same point before chain scission occurs and, consequently, a molecular weight degradation which leads to the deterioration of the mechanical properties.

With respect to the radicals R ₃ , R ₄ , R ₅ , R ₆ , it is equally within the scope of the present invention that each radical R ₃ , R ₄ , R ₅ , and R _{6 is} also selected from more than one substituent of the corresponding phenyl ring the said group represents.

In a preferred embodiment of the invention, the radicals R ₁ and R _{2 may be} selected from the group of the linear or branched C ₁ -C 20 -alkyl radicals, the C ₁ -C 20 -aryl radicals and the C ₁ -C 20 -heteroaryl radicals.

In a further preferred embodiment of the invention, the amino groups may each be arranged in the para or meta position to the disiloxane group. As a result, particularly readily available starting chemicals can be used for the preparation of the tetraaminodisiloxanes according to the invention, which can bring about a significant cost advantage for the resulting polyimides. In addition, the para- and / or meta-aminophenyl groups mentioned have just been found to be such sturcture units which can meet the objective of a high melting point but below the decomposition temperature and at the same time ensure good mechanical properties of the resulting polymers.

Preferably, R ₁ and R _{2 can be} selected from the group of the phenyl and naphthyl radicals and the amino groups can be arranged in the para and / or meta position to the disiloxane group. In particular, tetraaminodislioxanes of the general formulas (II) or (III) are preferably used for the preparation of polyimides with outstanding properties because of their structure:

• a) mindestens einem erfindungsgemäßen Tetraaminodisiloxan und
• b) mindestens einer organischen Tetracarbonsäure oder eines Tetracarbonsäurederivats.

Another feature of the present invention is a polyimide prepared by reacting

• a) at least one tetraaminodisiloxane according to the invention and
• b) at least one organic tetracarboxylic acid or a tetracarboxylic acid derivative.

In a preferred embodiment of the present invention, the tetracarboxylic acid component b) can be selected from the group benzene-1,2,4,5-tetracarboxylic acid-1,2: 4,5-dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride and 4,4'-oxybis (phthalic anhydride).

Further preferably, the Tetraaminosisiloxankomponente a) be selected from the group of para- and / or meta-Tretraaminophenyl disiloxanes having the radicals R ₁ , R ₂ , the same or different, selected from the group of linear or branched alkyl radicals, the aryl radicals and heteroaryl. Particularly preferably, the radicals R ₁ and R _{2 are} phenyl radicals.

A polyimide according to the invention may preferably be used for producing an injection-molded part, as a component in the engine compartment of a motor vehicle, as a bearing component or as an insulation material in the printing or electronics industry. Due to their good combination of mechanical and thermal properties, the polymers produced according to the invention can be used in particular as building materials for the manufacture of highly stressed thermal components in the engine compartment of motor vehicles such as seals or piston rings, and as a replacement for the commercial polymer "Vespel" from DuPont. which is used as a sintered material for bearings.

Examples

1 Preparation of tetraaminodisiloxanes according to the formula (I): 1.1 Reaction of bromoaniline with tert-butyl dicarbonate (Boc ₂ O)

20 g (0.116 mol) of bromoaniline were dispersed in 234 ml of water. The di-tert-butyl dicarbonate (Boc ₂ O, 25.65 g, 0.116 mol) was melted at 80 ° C and added dropwise to the dispersion at RT. The reaction mixture was then stirred at RT for 24 h. The suspension was subjected to filtration. The powder was washed three times with water and dried at 80 ° C.

1.1.A tert -Butyl N- (4-bromophenyl) carbamate (white powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 1:37 (s, 9H, -CH _3); 7.23 (d, 2H, phenyl); 7.29 (d, 2H, phenyl); 8.43 (s, 1H, -NH-) ¹³ C (500 MHz, THF-d8): δ (ppm) = 28 (-CH ₃ ); 79 (-C-); 115 (phenyl C-Br); 121 (phenyl CH); 132 (phenyl CH); 140 (phenyl C-NH-); 154 (-C = O) IR: v (cm ^-1 ) = 3367 (s, -NH); 2979 (s, -CH ₃ ); 1696 (s, -C = O); 1068 (s, -Br)

1.1B tert -Butyl N- (3-bromophenyl) carbamate (brown powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 1.5 (s, 9H, -CH _3); 7.09 (t, 2H, phenyl); 7.31 (d, 1H, phenyl); 7.81 (s, 1H, phenyl); 8.6 (s, 1H, -NH-). ¹³ C (500 MHz, THF-d8): δ (ppm) = 26 (-CH ₃ ); 78 (-C-); 114 (phenyl CH); 119 (C-Br); 120 (phenyl CH); 123 (phenyl CH); 128 (phenyl CH), 139 (phenyl C-NH-); 150.9 (-C = O). IR: v (cm ^-1 ) = 3309 (s, -NH-); 2975 (s, -CH ₃ ); 1609 (s, -C = O); 1068 (s, phenyl C-Br).

1.2 Lithiation of tert-butyl N- (4-bromophenyl) carbamate and tert-butyl N- (3-bromophenyl) carbamate with butyllithium

All steps were carried out in an inert gas atmosphere (argon, 99.999%). The solvents (tetrahydrofuran, hexane) were dried before use in an argon atmosphere using a Na / K alloy. 23.5 mL of a 2.5 M butyllithium solution in hexane were diluted in 150 mL of hexane. This solution was slowly added to a solution of 15 g (0.045 mol) of tert-butyl N- (4-bromophenyl) carbamate or tert-butyl N- (3-bromophenyl) carbamate cooled to -80 ° C. in 350 ml of tetrahydrofuran dropwise. The reaction solution was stirred for 5 h at -80 ° C and then subjected without further processing of a reaction with the chloro-substituted siloxanes (see 1.3).

1.3: Reaction of tert-butyl N- (4-lithiophenyl) carbamate or of tert-butyl N- (3-lithiophenyl) carbamate with chlorine-substituted disilanes

To the -80 ° C solution obtained by lithiation of the tert-butyl N- (4-bromophenyl) carbamate or tert-butyl N- (3-bromophenyl) carbamate (see 1.2) a solution was obtained Of 4.86 g of trichlorophenylsilane in 50 mL of hexane is slowly added dropwise. The solution was then stirred at -80 ° C for 5 h. Then the solvent was removed in vacuo (10 ^-2 mbar).

Chlorophenyl bis (4- (tert-butylcarbamate-N-yl) phenyl) silane (white powder):

• NMR: ¹ H (500 MHz, THF-d ^8): δ (ppm) = 1:36 (s, 18H, -CH _3); 6.93 (d, 3H, phenyl CH); 7.29 (te, 6H, phenyl CH); 7.8 (d, 4H, phenyl CH); 8.59 (s, 2H, -NH-). ¹³ C (500 MHz, THF-d ⁸ ): δ (ppm) = 28 (-CH ₃ ); 83 (-C-); 120 (phenyl CH); 128 (phenyl CH); 132 (phenyl CH); 136 (phenyl C-Si); 140 (phenyl C-NH-); 156 (-C = O). ²⁹ Si (500 MHz, THF-d8): δ (ppm) = -25. IR: v (cm ^-1 ) = 3417 (s, -NH-); 2977 (s, -CH ₃ ); 1698 (s, C = O); 1430 (s, Si-C phenyl); 1120 (w, Si-C phenyl); 700 (s, Si-C phenyl).

Chlorophenyl bis (3- (tert-butylcarbamate-N-yl) phenyl) silane (white powder):

• Δ (ppm) = 1:36 (s, 18H, -CH 3); NMR: ¹ H (500 MHz, THF-d ⁸⁾ 6.96 (te, 2H, phenyl CH); 7.25, (te, 5H, phenyl CH); 7.48 (d, 2H, phenyl CH); 7.73 (d, 2H, phenyl CH); 7.84 (d, 2H, phenyl CH); 8.66 (s, 2H, -NH-) ¹³ C (500 MHz, THF-d ⁸ ): δ (ppm) = 28 (-CH3); 82 (-C-); 122 (phenyl C-Si); 124 (phenyl CH); 128 (phenyl CH); 130 (phenyl CH); 133 (phenyl CH); 135 (phenyl CH); 141 (phenyl C-NH-); 155 (-C = O) ²⁹ Si (500 MHz, THF-d ⁸ ): δ (ppm) = -25 IR: v (cm ^-1 ) = 3331 (s, -NH-); 2975 (s, -CH3); 1732 (s, C = O); 1428 (m, Si-Cphenyl); 1153 (w, Si-C phenyl); 694 (s, Si-C phenyl).

1.4: Hydrolysis of chlorophenyl bis (4- (tert-butylcarbamate-N-yl) phenyl) silane and of chlorophenyl bis (3-tert-butylcarbamate-N-yl) phenyl) silane

Chlorophenyl bis (4- (tert-butylcarbamate-N-yl) phenyl) silane or chlorophenyl bis (3- (tert-butylcarbamate-N-yl) phenyl) silane was reacted with water at RT. Hydrolysis produces silanols which are converted into disiloxanes in a condensation step. Subsequently, the powder was washed three times with water and dried at 80 ° C.

1,1,3,3-tetra (4- (tert-butylcarbamate-N-yl) phenyl) -1,3-diphenyldisiloxane (pink powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 1:42 (s, 36H, -CH _3); 6.82 (d, 14H, phenyl CH); 6.96 (d, 12H, phenyl CH); 8.26 (s, 4H, -NH-). ¹³ C (500 MHz, THF-d8): δ (ppm) = 26 (-CH ₃ ); 77.5 (-C-); 112 (phenyl CH); 118 (phenyl CH); 126 (phenyl CH); 130 (phenyl CH); 132 (phenyl C-Si); 138 (phenyl C-NH-); 151.5 (-C = O). ²⁹ Si (500 MHz, THF-d8): δ (ppm) = -80. IR: v (cm ^-1 ) = 3367 (s, -NH-); 2982 (s, -CH ₃ ); 1696 (s, C = O); 1430 (s, Si-C phenyl); 1120 (m, Si-Cphenyl); 1050 (s, Si-C); 700 (s, Si-C phenyl).

1,1,3,3-Tetra (3- (tert-butylcarbamate-N-yl) phenyl) -1,3-diphenyldisiloxane (pink powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 1:43 (s, 36H, -CH _3); 6.58 (te, 14H, phenyl CH); 6.84 (d, 4H, phenyl CH); 7.31 (s, 8H, phenyl CH); 8.17 (s, 4H, -NH-). ¹³ C (500 MHz, THF-d8): δ (ppm) = 26 (-CH ₃ ); 78 (-C-); 114 (phenyl CH); 120 (phenyl CH); 123 (phenyl CH); 125 (phenyl CH); 128 (phenyl CH); 132 (phenyl C-Si); 140 (phenyl C-NH-); 51 (-C = O). ²⁹ Si (500 MHz, THF-d8): δ (ppm) = -80. IR: v (cm ^-1 ) = 3421 (s, -NH-); 2973 (s, -CH ₃ ); 1691 (s, C = O); 1430 (s, Si-C phenyl); 1125 (m, Si-Cphenyl); 1056 (s, -Si-O); 697 (s, Si-C phenyl).

1.5 Removal of the tert-butyl carbamate by reaction with trifluoroacetic acid in toluene at RT

The tert-butylcarbamate-protected disiloxanes obtained in 1.3 and 1.4 were deprotected in a reaction with trifluoroacetic acid. To a solution of 1.41 × 10 ^-2 mol protected disiloxane (14.93 g) in 45 mL toluene was added dropwise 0.07 mol (12 mL) trifluoroacetic acid. The reaction solution was stirred for 3 h at RT and then the solvent was removed in vacuo (10 ^-2 mbar). The product was then treated with water and the suspension brought to a neutral pH (pH = 7) by means of a 0.5 M NaOH solution. Subsequently, the suspension was subjected to filtration. The powder was then washed three times with water and dried at RT.

1,1,3,3-tetra (4-aminophenyl) -1,3-diphenyldisiloxane (pink powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 6.7 (d, 8H, -NH _2); 7.16 (d, 14H, phenyl CH); 7.72 (s, 12H, phenyl CH). ¹³ C (500 MHz, THF-d8): δ (ppm) = 109 (phenyl CH); 116 (phenyl CH); 128 (phenyl CH); 132 (phenyl CH); 134 (phenyl C-Si); 147 (phenyl C-NH ₂ ). ²⁹ Si (500 MHz, THF-d8): δ (ppm) = -80. IR: v (cm ^-1 ) = 3600 (m, -NH ₂ ); 3385 (s, -NH ₂ ); 1430 (s, Si-C phenyl); 1130 (s, Si-C phenyl); 1068 (see Si-O); 700 (s, Si-C phenyl).

1,1,3,3-Tetra (3-aminophenyl) -1,3-diphenyldisiloxane (pink powder):

• NMR: ¹ H (500 MHz, THF-d8): δ (ppm) = 6.42 (d, 8H, -NH 2); 6.57 (d, 8H, phenyl CH); 6.70 (s, 8H, phenyl CH); 6.79 (t, 10H, phenyl CH). ¹³ C (500 MHz, THF-d8): δ (ppm) = 114 (phenyl CH); 118 (phenyl CH); 120 (phenyl CH); 123 (phenyl C-Si); 127 (phenyl CH); 130 (phenyl CH); 134 (phenyl CH); 149 (phenyl C-NH2). ²⁹ Si (500 MHz, THF-d8): δ (ppm) = -80. IR: v (cm ^-1 ) = 3399 (m, -NH ₂ ); 3071 (s, -NH ₂ ); 1432 (s, Si-Cphenyl); 1135 (s, Si-C phenyl); 1068 (see Si-O); 691 (s, Si-C phenyl).

2 Preparation of Disiloxane-Containing Polyimides According to the Invention 2.1 Reaction of the Tetraaminodisiloxanes with Tetracarboxylic Dianhydrides

To a solution of 4.09 × 10 ^-3 mol (2.69 g) tetra (aminophenyl) -substituted diphenyldisiloxane in 14 mL dimethylacetamide was added 8.18 × 10 ^-3 mol of tetracarboxylic dianhydride (1.78 g benzene-1,2,4,5-tetracarboxylic acid-1, 2: 4,5-dianhydride or 2.62 g, 3 ', 4,4'-benzophenone tetracarboxylic dianhydride or 2.52 g 4, 4'-oxybis (phthalic anhydride)). The reaction solution was stirred for 24 h at RT and used without further workup and characterization in the next reaction stage. 2.2 Thermal treatment of polyamic acids from 2.1 for the preparation of polyimides according to the invention

IR: v (cm^–1)= 1774 (m, Imid); 1721 (s, -C=O); 1435 (m, Si-C Phenyl); 1113 (s, Si-C Phenyl); 1070 (m, Si-O); 703 (m, Si-C Phenyl).
Zersetzungstemperatur (°C) = 443 (mittels TGA unter Ar-Atmosphäre bestimmt)

IR: v (cm^–1) = 1777 (m, Imid); 1720 (s, -C=O); 1430 (m, Si-C Phenyl); 1108 (s, Si-C Phenyl); 1068 (m, Si-O); 706 (m, Si-C Phenyl).
Zersetzungstemperatur (°C) = 380 (mittels TGA unter Ar-Atmosphäre bestimmt).

IR: v (cm^–1) 1781 (m, Imid); 1720 (s, -C=O); 1491 (m, Si-C Phenyl); 1120 (m, Si-C Phenyl); 1012 (m, Si-O); 710 (s, Si-C Phenyl).
Schmelztemperatur (°C) = 401
Zersetzungstemperatur (°C) = 450 (mittels TGA unter Ar-Atmosphäre bestimmt).
450 (mittels TGA unter künstlicher Luft-Atmosphäre bestimmt)

IR: v (cm^–1) = 1779 (m, Imid); 1723 (s, -C=O); 1428 (m, Si-C Phenyl); 1130 (s, Si-C Phenyl); 1077 (s, Si-O); 697 (m, Si-C Phenyl).
Schmelztemperatur (°C) = 200
Zersetzungstemperatur (°C) = 350 (mittels TGA unter Ar-Atmosphäre bestimmt).

IR: v (cm^–1) = 1777 (m, Imid); 1723 (s, -C=O); 1430 (m, Si-C Phenyl); 1237 (m, C-O-C); 1130 (s, Si-C Phenyl); 1068 (s, Si-O); 697 (m, Si-C Phenyl).
Schmelztemperatur (°C) = 235
Zersetzungstemperatur (°C) = 352 (mittels TGA unter Ar-Atmosphäre bestimmt).

IR: v (cm^–1) 1779 (m, Imid); 1718 (s, -C=O); 1428 (m, Si-C Phenyl); 1237 (m, C-O-C); 1133 (s, Si-C Phenyl); 1032 (m, Si-O); 697 (m, Si-C Phenyl).
Schmelztemperatur (°C) = 200
Zersetzungstemperatur (°C) = 347 (mittels TGA unter Ar-Atmosphäre bestimmt).The polyamic acid solution obtained under point 2.1 was heated at 150.degree. C. for 12 hours. Depending on the polyamic acid used, the polyimide precipitates out of solution or remains in the solution. When the polyimide precipitates out of solution, the resulting suspension was filtered, the solid product washed with water and then dried at 80 ° C. If the product remains in the solution, it was precipitated by the addition of water and then subjected to work-up as described above.

IR: v (cm ^-1 ) = 1774 (m, imide); 1721 (s, -C = O); 1435 (m, Si-Cphenyl); 1113 (s, Si-C phenyl); 1070 (m, Si-O); 703 (m, Si-C phenyl).
Decomposition temperature (° C) = 443 (determined by TGA under Ar atmosphere)

IR: v (cm ^-1 ) = 1777 (m, imide); 1720 (s, -C = O); 1430 (m, Si-Cphenyl); 1108 (s, Si-Cphenyl); 1068 (m, Si-O); 706 (m, Si-C phenyl).
Decomposition temperature (° C) = 380 (determined by TGA under Ar atmosphere).

IR: v (cm ^-1 ) 1781 (m, imide); 1720 (s, -C = O); 1491 (m, Si-Cphenyl); 1120 (m, Si-Cphenyl); 1012 (m, Si-O); 710 (s, Si-C phenyl).
Melting temperature (° C) = 401
Decomposition temperature (° C) = 450 (determined by TGA under Ar atmosphere).
450 (determined by TGA under artificial air atmosphere)

IR: v (cm ^-1 ) = 1779 (m, imide); 1723 (s, -C = O); 1428 (m, Si-Cphenyl); 1130 (s, Si-C phenyl); 1077 (s, Si-O); 697 (m, Si-C phenyl).
Melting temperature (° C) = 200
Decomposition temperature (° C) = 350 (determined by TGA under Ar atmosphere).

IR: v (cm ^-1 ) = 1777 (m, imide); 1723 (s, -C = O); 1430 (m, Si-Cphenyl); 1237 (m, COC); 1130 (s, Si-C phenyl); 1068 (s, Si-O); 697 (m, Si-C phenyl).
Melting temperature (° C) = 235
Decomposition temperature (° C) = 352 (determined by TGA under Ar atmosphere).

IR: v (cm ^-1 ) 1779 (m, imide); 1718 (s, -C = O); 1428 (m, Si-Cphenyl); 1237 (m, COC); 1133 (s, Si-C phenyl); 1032 (m, Si-O); 697 (m, Si-C phenyl).
Melting temperature (° C) = 200
Decomposition temperature (° C) = 347 (determined by TGA under Ar atmosphere).

Claims (9)

Tetraaminodisiloxane of the following formula (I)

with R ₁ , R ₂ , identical or different, selected from the group of the linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals, and R ₃ , R ₄ , R ₅ , R _6, identical or different, selected from among Group H, the linear, branched or cyclic alkyl radicals, alkenyl radicals, alkynyl radicals, aryl radicals, heteroaryl radicals, halogens and pseudohalogens. Tetraaminodisiloxane according to claim 1, characterized in that the radicals R ₁ and R _{2 are} selected from the group of linear or branched C 1 -C 20 -alkyl radicals, the C 1 -C 20 -aryl radicals and the C 1 -C 20 -heteroaryl radicals. Tetraaminodisiloxane according to claim 1 or 2, characterized in that the amino groups are each arranged in para or meta position to the disiloxane group. Tetraaminodisiloxane according to one of the preceding claims, characterized in that R ₁ and R _{2 are} selected from the group of phenyl and naphthyl radicals and the amino groups are arranged in the para and / or meta position to the disiloxane group. Polyimide prepared by reaction of a) at least one tetraaminodisiloxane according to any one of claims 1 to 4 and b) at least one organic tetracarboxylic acid or a tetracarboxylic acid derivative. Polyimide according to claim 5, characterized in that the tetracarboxylic acid component b) is selected from the group benzene-1,2,4,5-tetracarboxylic acid 1,2: 4,5-dianhydride, 3,3 ', 4,4'- Benzophenonetetracarboxylic dianhydride and 4,4'-oxybis (phthalic anhydride). Polyimide according to one of claims 5 or 6, characterized in that the Tetraaminosisiloxankomponente a) is selected from the group of para- and / or meta-Tretraaminophenyl disiloxanes having the radicals R ₁ , R ₂ same or different selected from the group of the linear or branched alkyl radicals, the aryl radicals and the heteroaryl radicals. Polyimide according to one of claims 5 to 7, characterized in that R ₁ and R _{2 are} phenyl radicals. Use of a polyimide according to one of claims 5 to 8 for producing an injection molded part, as a component in the engine compartment of a motor vehicle, as a bearing component or as an insulating material in the printing or electronics industry.