Aerogel-containing polyurethane composite material

Abstract

The present invention relates to a composite material comprising nanoporous particles and at least one binder constructed from at least one isocyanate and at least one polymer P selected from the group consisting of polyvinylamine, poly(meth)acrylic acid, poly(meth)acrylic ester, polyvinyl alcohol, polyvinylthiol and mixtures thereof, wherein said at least one binder is used in an amount of 0.1 to 20 wt %, based on the amount of nanoporous particles, a composition for producing a composite material of this type, a process for producing a composite material of this type, shaped articles comprising said composite material and the use of said composite material for thermal and/or acoustical insulation.

Claims

1. A composite material comprising nanoporous aerogel particles or pyrogenous silica particles, and at least one binder prepared by reacting at least one water-emulsifiable prepolymer and at least one water-soluble, or water-dispersible polymer selected from the group consisting of a polyvinylamine having a molecular weight of 10,000 to 1,000,000 g/mol, a polyvinyl alcohol having a molecular weight of 10,000 to 500,000 g/mol, a polyvinylthiol having a molecular weight of 10,000 to 500,000 g/mol, and any mixture thereof, wherein the reaction results in crosslinking of the at least one water-emulsifiable prepolymer with the at least one water-soluble or water-dispersible polymer, wherein the at least one binder is present in an amount of 0.1 wt % to 20 wt %, relative to an amount of the nanoporous aerogel particles or the pyrogenous silica particles, and the at least one water-emulsifiable prepolymer is prepared from an isocyanate compound and at least one compound that includes Zerewitinow-reactive groups selected from the group consisting of a polyol, a sulfonic acid, and mixtures thereof.

2. The composite material according to claim 1 wherein the nanoporous aerogel particles or the pyrogenous silica particles are granular.

3. The composite material according to claim 1 wherein the at least one compound comprising Zerewitinow-reactive groups is a polyethylene glycol having a molecular weight of 200 to 6000 g/mol, an alkylpolyethylene glycol having a molecular weight of 200 to 2000 g/mol, or any mixture thereof.

4. The composite material according to claim 1 wherein the nanoporous aerogel particles or the pyrogenous silica particles includes a hydrophobic coating.

5. The composite material according to claim 1 wherein the at least one water-soluble, or water-dispersible polymer comprises the mixture of the polyvinylamine, the polyvinyl alcohol, and a polyacrylic acid having a molecular weight of 1000 to 400,000 g/mol, and a filler selected from the group consisting of sheet-silicates, clay minerals, metal oxides, silica gel, and glass spheres.

6. A process for producing a composite material according to claim 1, comprising: reacting at least one water-emulsifiable prepolymer, and at least one water-soluble or water-dispersible polymer selected from the group consisting of a polyvinylamine having a molecular weight of 10,000 to 1,000,000 g/mol, a polyvinyl alcohol having a molecular weight of 10,000 to 500,000 g/mol, a polyvinylthiol having a molecular weight of 10,000 to 500,000 g/mol, and any mixture thereof, wherein the reaction results in crosslinking of the at least one water-emulsifiable prepolymer with the at least one water-soluble or water-dispersible polymer to provide a composition; mixing the composition with nanoporous aerogel particles or pyrogenous silica particles to form a mixture that is a) subjected to a shaping operation and optional curing, or b) pelletized, and subjected to shaping and optionally curing.

7. A shaped article comprising a composite material according to claim 1 and at least one additional foam material.

8. The shaped article according to claim 7 wherein the at least one additional foam material is laminated to the composite material, or mixed with the composite material.

9. The shaped article according to claim 8 wherein the at least one additional foam material comprises polyurethane, polystyrene, or a mixture thereof.

10. The shaped article according to claim 7 further comprising at least one outer layer that is laminated to the composite material.

11. A thermal or acoustical insulation comprising the composite material according to claim 1.

12. A composite material comprising: nanoporous aerogel particles or pyrogenous silica particles; and a binder prepared from reacting a mixture of a polyvinylamine having a molecular weight of 10,000 to 500,000 g/mol, a polyvinyl alcohol having a molecular weight of 10,000 to 100,000 g/mol, and a water-emulsifiable prepolymer prepared from an isocyanate compound and a compound that includes Zerewitinow-reactive groups selected from the group consisting of a polyol, a sulfonic acid, and a mixture thereof, wherein the reaction of said polyvinylamine, polyvinyl alcohol and water-emulsifiable prepolymer results in crosslinking of the water-emulsifiable prepolymer with polyvinylamine and polyvinyl alcohol, wherein the binder is present in an amount of 0.1 wt % to 20 wt %, relative to an amount of the nanoporous aerogel particles or the pyrogenous silica particles.

13. The composite material according to claim 12 in the form of a plate.

14. The composite material according to claim 12 wherein the compound that includes Zerewitinow-reactive groups is an isocyanate-reactive sulfonic acid.

15. The composite material according to claim 12 wherein the prepolymer prepared from an isocyanate compound and a compound comprising Zerewitinow-reactive groups is a polyethylene glycol having a molecular weight of 200 to 6000 g/mol, an alkylpolyethylene glycol having a molecular weight of 200 to 2000 g/mol, or any mixture thereof.

16. The composite material according to claim 15 wherein the binder further comprises a polyacrylic acid having a molecular weight of 1000 to 400,000 g/mol, the composite material further comprises a filler selected from the group consisting of sheet-silicates, clay minerals, metal oxides, silica gel, and glass spheres, and the composite material has a flexural strength/stress at 10% compression of from 50 kPa to 130 kPa.

17. The composite material according to claim 12, wherein the composite material has a thermal conductivity of 12 to 22 mW/m.Math.K.

18. The composite material according to claim 12 wherein the binder further comprises a polyacrylic acid having a molecular weight of 1000 to 400,000 g/mol.

19. The composite material according to claim 18 further comprising a filler selected from the group consisting of sheet-silicates, clay minerals, metal oxides, silica gel, and glass spheres, and the composite material has a flexural strength/stress at 10% compression of from 50 kPa to 130 kPa.

20. The composite material according to claim 12, wherein the nanoporous aerogel particles are is present and the composite material has a thermal conductivity of 12 to 22 mW/m.Math.K.

21. The composite material according to claim 12, wherein the pyrogenous silica particles are present and the composite material has a thermal conductivity of 12 to 22 mW/m.Math.K.

22. A composite material comprising: nanoporous aerogel particles or pyrogenous silica particles, at least one binder prepared by reacting at least one water-emulsifiable prepolymer, and at least one water-soluble, or water-dispersible polymer prepared from a polyvinylamine having a molecular weight of 10,000 to 1,000,000 g/mol, a polyvinyl alcohol having a molecular weight of 10,000 to 500,000 g/mol, and a polyacrylic acid having a molecular weight of 1000 to 400,000 g/mol, wherein the reaction of the water-emulsifiable prepolymer with the at least one water-soluble or water-dispersible polymer results in crosslinking of the water-emulsifiable prepolymer with the at least one water-soluble or water-dispersible polymer, and a filler selected from the group consisting of sheet-silicates, clay minerals, metal oxides, silica gel, and glass spheres, wherein the at least one binder is present in an amount of 0.1 wt % to 20 wt %, relative to an amount of the nanoporous aerogel particles or the pyrogenous silica particles and the at least one water-emulsifiable prepolymer is prepared from an isocyanate compound and at least one compound that includes Zerewitinow-reactive groups selected from a polyol, a sulfonic acid, or a mixture thereof.

Description

EXAMPLES

(1) The following components were used in the examples and comparative tests: Polymer 1: Lupamin 9095 linear polyvinylamine from BASF SE, Ludwigshafen, Germany, average molecular weight 340 000 g/mol, 20 wt % solution in water Polymer 2: polyacrylic acid from Sigma-Aldrich Chemie GmbH, Steinheim, Germany, average molecular weight Mw=100 000 g/mol, 35 wt % solution in water Polymer 3: polyvinyl alcohol from Sigma-Aldrich Chemie GmbH, Steinheim, Germany, average molecular weight Mw=31 000 to 50 000 g/mol, 87 to 89% hydrolyzed, a solid material Prepolymer 1: isocyanate obtained from the reaction of Basonat HA 300 (Allophanate-modified polyisocyanate based on isocyanurated hexamethylene diisocyanate, solvent-free, NCO content 19 to 20%) with 2 wt % of Pluriol A500E (methylated polyethylene glycol, average molecular weight 500 g/mol), both BASF SE, Ludwigshafen, Germany, a liquid material Prepolymer 2: Basonat F 200 WD water-emulsifiable isocyanate based on hexamethylene diisocyanate, solvent-free, from BASF SE, Ludwigshafen, Germany, a liquid material SiO.sub.2 aerogel: Cabot Nanogel TLD 302, SiO.sub.2, (trimethylsilyl)oxy-modified Filler 1: Aerosil 200 hydrophilic pyrogenous silica having a specific surface area of 200 m.sup.2/g, from Evonik Industries AG, Essen, Germany, a solid material Filler 2: C14 barite flour, 82 wt % of BaSO.sub.4, 11 wt % of CaF.sub.2, 6 wt % of SiO.sub.2, from Sachtleben GmbH, Duisburg, Germany, a solid material Hollow glass spheres: 3M Glass Bubbles S32, hollow sphere diameter 90%<70 m, typical density 320 g/L, from 3M, St. Paul, USA, a solid material

Example 1

(2) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 5.8 g of polymer 1 (reckoned as solid material). This mixture was admixed with an emulsion of 2.9 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(3) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(4) Plate thickness: 2.2 cm

(5) Density: 120 g/L

(6) Binder content: 7.9 wt %

(7) Thermal conductivity: 16.7 mW/m*K at 10 C.

(8) Compressive strength/stress: 85 kPa

(9) Flexural strength/stress

(10) at 10% compression: 30 kPa

(11) E modulus: 1030 kPa

Example 2

(12) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 5.8 g of polymer 1 (reckoned as solid material). This mixture was admixed with an emulsion of 2.9 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(13) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(14) Plate thickness: 2.3 cm

(15) Density: 111 g/L

(16) Binder content: 8.2 wt %

(17) Thermal conductivity: 16.1 mW/m*K at 10 C.

(18) Compressive strength/stress: 41 kPa

(19) Flexural strength/stress

(20) at 10% compression: 20 kPa

(21) E modulus: 470 kPa

Example 3

(22) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 5.8 g of polymer 3 (reckoned as solid material). This mixture was admixed with an emulsion of 2.9 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(23) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(24) Plate thickness: 2.2 cm

(25) Density: 116 g/L

(26) Binder content: 8.2 wt %

(27) Thermal conductivity: 16.1 mW/m*K at 10 C.

(28) Compressive strength/stress: 53 kPa

(29) Flexural strength/stress

(30) at 10% compression: 40 kPa

(31) E modulus: 690 kPa

Example 4

(32) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 4.3 g of polymer 3 (reckoned as solid material). This mixture was admixed with an emulsion of 2.1 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(33) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(34) Plate thickness: 2.5 cm

(35) Density: 100 g/L

(36) Binder content: 6.1 wt %

(37) Thermal conductivity: 16.9 mW/m*K bei 10 C.

(38) Compressive strength/stress: 27 kPa

(39) Flexural strength/stress

(40) at 10% compression: 20 kPa

(41) E modulus: 330 kPa

Example 5

(42) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 7.5 g of polymer 3 (reckoned as solid material). This mixture was admixed with an emulsion of 3.6 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(43) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(44) Plate thickness: 2.4 cm

(45) Density: 110 g/L

(46) Binder content: 10.1 wt %

(47) Thermal conductivity: 16.1 mW/m*K bei 10 C.

(48) Compressive strength/stress: 45 kPa

(49) Flexural strength/stress

(50) at 10% compression: 40 kPa

(51) E modulus: 480 kPa

Example 6

(52) 100 g of SiO.sub.2 aerogel were mixed with 100 g of an aqueous solution comprising 9.1 g of polymer 3 (reckoned as solid material). This mixture was admixed with an emulsion of 4.6 g of prepolymer 1 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(53) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(54) Plate thickness: 2.5 cm

(55) Density: 107 g/L

(56) Binder content: 12.4 wt %

(57) Thermal conductivity: 17.1 mW/m*K bei 10 C.

(58) Compressive strength/stress: 22 kPa

(59) Flexural strength/stress

(60) at 10% compression: 30 kPa

(61) E modulus: 180 kPa

(62) The inventive examples are able to show that specifically the binder content of the present invention gives particularly advantageous properties, for example thermal conductivity and mechanical parameters.

Example 7

(63) 100 g of SiO.sub.2 aerogel were mixed with 73.5 g of an aqueous solution comprising 4.35 g of polymer 1 (reckoned as solid material). This mixture was admixed with 26.5 g of an aqueous solution comprising 1.45 g of polymer 3 (reckoned as solid material). To this mixture was added an emulsion of 2.9 g of prepolymer 2 in 5 g of water, obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(64) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(65) Plate thickness: 2.1 cm

(66) Density: 129 g/L

(67) Binder content: 11.4 wt %

(68) Thermal conductivity: 16.7 mW/m*K bei 10 C.

(69) Compressive strength/stress: 76 kPa

(70) Flexural strength/stress

(71) at 10% compression: 50 kPa

(72) E modulus: 940 kPa

Example 8

(73) 73.5 g of an aqueous solution comprising 4.35 g of polymer 1 (reckoned as solid material) were mixed with 26.5 g of an aqueous solution comprising 1.45 g of polymer 3 (reckoned as solid material). 25 g of hollow glass spheres were stirred into this solution. 100 g of SiO.sub.2 aerogel were stirred up with the mixture described above, followed by the addition of an emulsion of 2.9 g of prepolymer 2 in 5 g of water obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(74) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(75) Plate thickness: 2.2 cm

(76) Density: 148 g/L

(77) Binder content: 7.9 wt %

(78) Thermal conductivity: 19.0 mW/m*K bei 10 C.

(79) Compressive strength/stress: 139 kPa

(80) Flexural strength/stress

(81) at 10% compression: 130 kPa

(82) E modulus: 2090 kPa

Example 9

(83) 73.5 g of an aqueous solution comprising 4.35 g of polymer 1 (reckoned as solid material) were mixed with 26.5 g of an aqueous solution comprising 1.45 g of polymer 3 (reckoned as solid material). 2.9 g of filler 1 were stirred into this solution. 100 g of SiO.sub.2 aerogel were stirred up with the mixture described above, followed by the addition of an emulsion of 2.9 g of prepolymer 2 in 5 g of water obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(84) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(85) Plate thickness: 2.2 cm

(86) Density: 126 g/L

(87) Binder content: 10.7 wt %

(88) Thermal conductivity: 16.6 mW/m*K bei 10 C.

(89) Compressive strength/stress: 53 kPa

(90) Flexural strength/stress

(91) at 10% compression: 50 kPa

(92) E modulus: 700 kPa

Example 10

(93) 73.5 g of an aqueous solution comprising 4.35 g of polymer 1 (reckoned as solid material) were mixed with 26.5 g of an aqueous solution comprising 1.45 g of polymer 3 (reckoned as solid material). 25 g of filler 2 were stirred into this solution. 100 g of SiO.sub.2 aerogel were mixed with 25 g of filler 2 and stirred up with the mixture described above, followed by the addition of an emulsion of 2.9 g of prepolymer 2 in 5 g of water obtained by vigorous shaking in a closed plastics container, followed by further thorough commixing. The mass was placed in a PE-film-lined metallic mold measuring 20.4 cm20.4 cm4 cm, and squeezed down to a thickness of about 2 cm with a screw device.

(94) The entire device was stored at 60 C. for 1 h, and the composite plate obtained was demolded and dried in an oven at 60 C. to constant weight. The following values were measured on the plate after it had cooled down:

(95) Plate thickness: 2.1 cm

(96) Density: 184 g/L

(97) Binder content: 6.5 wt %

(98) Thermal conductivity: 19.1 mW/m*K bei 10 C.

(99) Compressive strength/stress: 84 kPa

(100) Flexural strength/stress

(101) at 10% compression: 80 kPa

(102) E modulus: 900 kPa

(103) Small amounts of filler have a positive effect on the processability of the polymer solutions, since their viscosity increases, thus making it possible to achieve better disbursement on and between the aerogel particles. The final properties of the composite plate remain virtually unchanged.

(104) Higher proportions of hollow glass spheres have a similar improving effect on the processability and also the mechanical end properties of the composite plates.

(105) Example 8 shows the use of a filler of relatively low density, while Example 10 utilizes a filler of relatively high density. In both cases, the overall flammability of the composite material can be reduced by using the additional inorganic material. The effects on the physical properties point essentially in the same direction, but do vary in their absolute magnitude, which is attributable to density, volume and surface area of the particular fillers and also their influence on the adhesive bonding of the composite material.