A REACTION MIXTURE FOR MANUFACTURING AN INORGANIC-FILLER BASED CLOSED-CELL RIGID POLYURETHANE OR POLYISOCYANURATE CONTAINING FOAM

Abstract

The present invention relates to a reaction mixture for manufacturing an inorganic-filler based closed-cell rigid polyurethane or polyisocyanurate (PU or PIR) containing foam having a calorific value below 6 MJ/kg, preferably below 4.5 MJ/kg, more preferably below 3 MJ/kg, measured according to EN ISO 1716, the reaction mixture comprising: At least one polyisocyanate-containing compound; At least one isocyanate-reactive compound; An inorganic filler composition; At least one physical blowing agent;

characterised in that said inorganic filler composition has bulk density higher than 2 g/cm.sup.3, preferably higher than 2.1 g/cm.sup.3, more preferably higher than 2.2 g/cm.sup.3, even more preferably higher than 2.4 g/cm.sup.3.

Claims

1. A reaction mixture for manufacturing an inorganic-filler based closed-cell rigid polyurethane or polyisocyanurate containing foam having a calorific value below 6 MJ/kg, measured according to EN ISO 1716, the reaction mixture comprising: At least one polyisocyanate-containing compound; At least one isocyanate-reactive compound; An inorganic filler composition; At least one physical blowing agent; Optionally, a surfactant, a chemical blowing agent, a catalyst, a chain extender, a crosslinker, an antioxidant, a fire retardant and/or mixtures thereof; characterised in that said inorganic filler composition has bulk density higher than 2 g/cm.sup.3.

2. The reaction mixture according to claim 1, wherein said inorganic filler composition is present in an amount of at least 70 wt relative to the total weight of said reaction mixture, without taking into account the weight of said at least one physical blowing agent.

3. The reaction mixture according to claim 1, wherein said inorganic filler composition comprises a first inorganic filler selected from the group comprising bismuth oxide, zirconium (IV) oxide, iron (III) oxide, barium sulfate, barium carbonate, titanium (IV) oxide, aluminium oxide, magnesium oxide and combinations thereof.

4. The reaction mixture according to claim 1, wherein said inorganic filler composition has a thermal conductivity lower than 25 W/m.K.

5. The reaction mixture according to claim 1, wherein said first inorganic filler has a particle size distribution with a d90 value comprised in the range 10-2000 μm.

6. The reaction mixture according to claim 1, wherein said inorganic filler composition further comprises a second inorganic filler having bulk density lower than 2 g/cm.sup.3.

7. The reaction mixture according to claim 1, wherein said second inorganic filler is selected from the group comprising barium sulfate, aluminium silicate, magnesium silicate, calcium fluoride, Iron (III) sulfate, calcium sulfate, calcium carbonate, magnesium sulfate, silicon oxide, sodium carbonate, aluminium hydroxide, magnesium hydroxide, sodium chloride, calcium chloride, perlite and combinations thereof.

8. The reaction mixture according to claim 1, wherein said at least one physical blowing agent is selected from the list comprising isobutene, dimethyl ether, methylene chloride, acetone, chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), hydro(chloro)fluoroolefins (HFOs/HCFOs), dialkyl ethers, cycloalkylene ethers, ketones, fluorinated ethers, perfluorinated hydrocarbons, hydrocarbons and mixtures thereof.

9. The reaction mixture according to claim 1, wherein said at least one polyisocyanate-containing compound is selected from the group comprising toluene diisocyanate, methylene diphenyl diisocyanate, polyisocyanate composition comprising methylene diphenyl diisocyanate and mixtures thereof.

10. The reaction mixture according to claim 1, wherein said at least one isocyanate-reactive compound is a polyol having average hydroxyl number of from 50 to 1000 and hydroxyl functionality of from 2 to 8.

11. The reaction mixture according to claim 1, comprising a CO.sub.2 scavenger.

12. An inorganic-filler based closed-cell rigid polyurethane or polyisocyanurate containing foam having a calorific value below 6 MJ/kg, measured according to EN ISO 1716.

13. The foam according to claim 12, having a value below 35 mW/m.K at 10° C., measured according to ISO 8301.

14. The foam according to claim 12, having a density lower than 400 kg/m.sup.3, measured according to ISO 845.

15. The foam according to claim 12, wherein the percentage of closed cells is higher than 50% measured according to ISO 4590.

16. The foam according to claim 12, obtained by mixing the components of the reaction mixture according to claim 12.

17. Article An article comprising a foam according to claim 12.

18. The article according to claim 17, wherein the article is one or more of a composite panel, insulation board, external thermal insulation composite system (ETICS), pipe, garage door, appliance, spray-foam insulation.

Description

EXAMPLES

Methods

[0127] Density: foam density was measured on samples by dividing the mass by the volume and expressing it in kg/m.sup.3, as described in ISO 845.
Closed cell content (CCC): foam closed cell content was measured using an AccuPyc 1330 Pycnometer from Micromeritics according to ASTM D6226-15.
Calorific value: foam calorific value was measured with a bomb calorimeter according to EN ISO 1716. The foams were grinded into a fine powder and ˜0.7 g was used in combination with ˜0.3 g of paraffin as combustion aid.
Thermal insulation value: Foam lambda value was measured at 10° C. in a TA LaserComp Fox200 device according to ISO 8301.

Example 1

[0128] Production of a rigid polyisocyanurate insulation foam panel according to the invention filled with 80 wt. % of barium sulfate.
The following chemicals with the respective parts by weight were used for the polyisocyanurate foam panel production: Suprasec 5025 (polymeric MDI from Huntsman, NCOv 31%, 21 pbw), Daltolac R251 (polyether polyol from Huntsman, OHv 250, 6.22 pbw), Ethylene Glycol (OHv 1808, 0.34 pbw), Tegostab B8490 (silicone surfactant from Evonik, OHv 125, 0.175 pbw), water (OHv 6230, 0.082 pbw), Catalyst LB (48.2 wt. % potassium acetate from Huntsman, OHv 1097, 0.511 pbw), barite sand 100/500 (d90 value in the range 250-360 μm, inorganic filler from Sachtleben Bergbau with bulk density of about 2.2 g/cm.sup.3, 112 pbw, specific volume of about 0.45 L/kg), and isopentane (blowing agent, 5.38 pbw). Isocyanate index was 266.
The surfactant, the polyol, water, the chain extender and the catalyst were first mixed together to prepare a polyol blend. Suprasec 5025 and the barite sand were premixed separately with a Heidolph mixer for 60 seconds at around 500-1000 rpm to form a slurry. The polyol blend and the isopentane blowing agent were then added to the barite/Suprasec 5025 slurry and the entire composition was then mixed under high shear at about 3000 rpm for 20 seconds. Part of the blowing agent evaporated during this last step and was therefore not fully available for expanding the foam. The resulting foaming composition was then poured inside a 20×20×1 cm.sup.3 aluminum mold (pre-heated at 100° C. and with the top and bottom internal surfaces covered with paper facers) and allowed to cure for 30 minutes before demolding.
The foam panel had the following properties: core density of 250 kg/m.sup.3, closed-cell content of 75%, Lambda at 10° C. (measured after 24 h) of 28.7 mW/m.K and calorific value of 5 MJ/kg (core foam).

Example 2

[0129] Production of a rigid polyurethane insulation foam panel according to the invention filled with 85 wt. % of barium sulfate.
The following chemicals with the respective parts by weight were used for the polyurethane foam panel production: Suprasec 5025 (polymeric MDI from Huntsman, NCOv 31%, 21.72 pbw), Daltolac R411 (polyether polyol from Huntsman, OHv 420, 17.64 pbw), Tegostab B8444 (silicone surfactant from Evonik, 0.44 pbw), water (OHv 6230, 0.1 pbw), DMCHA(N,N-dimethylcyclohexylamine from Huntsman, 0.2 pbw), precipitated barium sulfate (d90 value <50 micrometers, inorganic filler from Acros Organics, bulk density of about 1.5 g/cm.sup.3, 40 pbw, specific volume of about 0.67 L/kg), Barite sand 500/2000 (d90 value in the range 1-2 mm, inorganic filler from Sachtleben Bergbau, bulk density of about 2.4 g/cm.sup.3, 186.6 pbw, specific volume of about 0.42 L/kg), and Solstice LBA (blowing agent from Honeywell, 24 pbw). Bulk density barium sulfate/barite mixture of about 3 g/cm.sup.3 (specific volume of about 0.33 L/kg, d90 value in the range 0.5-2 mm). Isocyanate index was 112.
The surfactant, the polyol and water were first mixed together to prepare a polyol blend. Suprasec 5025, the polyol blend, barite powder and barite sand were then mixed into a slurry with a Heidolph mixer for 30 seconds around 500-1000 rpm. The Solstice LBA blowing agent and the DMCHA catalyst were added to the Suprasec 5025/polyol blend/barite slurry and the entire composition was then mixed under high shear at about 3000 rpm for 20 seconds. Part of the blowing agent evaporated during this last step and was therefore not fully available for expanding the foam. The resulting foaming composition was then poured inside a 20×20×3 cm.sup.3 aluminum mold (pre-heated at 40° C. and with the top and bottom internal surfaces covered with aluminum facers) and allowed to cure for 30 minutes before demolding.
The foam panel had the following properties: core density of 200 kg/m.sup.3, closed-cell content of 83%, Lambda at 10° C. (measured after 24 h) of 24.6 mW/m.K and calorific value of 3.3 MJ/kg (core foam).

Example 3

[0130] Production of a rigid polyisocyanurate insulation foam panel according to the invention filled with 90 wt. % of barium sulfate.
The following chemicals with the respective parts by weight were used for the polyisocyanurate foam panel production: Suprasec 5025 (polymeric MDI from Huntsman, NCOv 31%, 10.5 pbw), Daltolac R251 (polyether polyol from Huntsman, OHv 250, 3.11 pbw), Ethylene Glycol (OHv 1808, 0.17 pbw), Tegostab B8490 (silicone surfactant from Evonik, OHv 125, 0.088 pbw), water (OHv 6230, 0.041 pbw), Catalyst LB (48.2 wt. % potassium acetate, from Huntsman, OHv 1097, 0.39 pbw), barite sand 500/2000 (d90 value in the range 1-2 mm, inorganic filler from Sachtleben Bergbau, bulk density of about 2.4 g/cm.sup.3, 126 pbw, specific volume of about 0.42 L/kg), and Solstice LBA (blowing agent from Honeywell, 10.3 pbw). Isocyanate index was 266.
The surfactant, the polyol, water, the chain extender and the catalyst were first mixed together to prepare a polyol blend. Suprasec 5025 and the barite sand were premixed separately with a Heidolph mixer for 60 seconds around 500-1000 rpm into a slurry. The polyol blend and the Solstice LBA blowing agent were then added to the barite/Suprasec 5025 slurry and the entire composition was then mixed under high shear at about 3000 rpm for 20 seconds. Part of the blowing agent evaporated during this last step and was therefore not fully available for expanding the foam. The resulting foaming composition was then poured inside a 20×20×1 cm.sup.3 aluminum mold (pre-heated at 100° C. and with the top and bottom internal surfaces covered with paper facers) and allowed to cure for 30 minutes before demolding.
The foam panel had the following properties: core density of 325 kg/m.sup.3, closed-cell content of 70%, Lambda value at 10° C. (measured after 2 h) of 27.0 mW/m.K and calorific value of 2.3 MJ/kg (core foam).

Example 4

[0131] Production of a rigid polyurethane insulation foam panel according to the invention filled with 87 wt. % of barium sulfate.
The following chemicals with the respective parts by weight were used for the polyurethane foam panel production: Suprasec 5025 (polymeric MDI from Huntsman, NCOv 31%, 32.58 pbw), Daltolac R411 (polyether polyol from Huntsman, OHv 420, 26.46 pbw), Tegostab B8444 (silicone surfactant from Evonik, 0.66 pbw), water (OHv 6230, 0.15 pbw), DMCHA(N,N-dimethylcyclohexylamine from Huntsman, 0.53 pbw), precipitated barium sulfate (d90 value <50 micrometers, inorganic filler from Acros Organics, bulk density of about 1.5 g/cm.sup.3, 60 pbw, specific volume of about 0.67 L/kg), Barite sand 500/2000 (d90 value in the range 1-2 mm, inorganic filler from Sachtleben Bergbau, bulk density of about 2.4 g/cm.sup.3, 342 pbw, specific volume of about 0.42 L/kg), and Solstice LBA (blowing agent from Honeywell, 50 pbw). Bulk density barium sulfate/barite mixture of about 3 g/cm.sup.3 (specific volume of about 0.33 L/kg, d90 value in the range 0.5-2 mm). Isocyanate index was 112.
The surfactant, the polyol and water were first mixed together to prepare a polyol blend. Suprasec 5025, the polyol blend, barite powder and barite sand were then mixed into a slurry with a Heidolph mixer for 30 seconds around 500-1000 rpm. The Solstice LBA blowing agent and the DMCHA catalyst were added to the Suprasec 5025/polyol blend/barite slurry and the entire composition was then mixed under high shear at about 3000 rpm for 15 seconds. Part of the blowing agent evaporated during this last step and was therefore not fully available for expanding the foam. The resulting foaming composition was then poured inside a 20×20×5 cm.sup.3 open top aluminum mold (pre-heated at 50° C. and with the internal surfaces covered with aluminum facers) and allowed to cure for 30 minutes before demolding.
The foam panel had the following properties: core density of 150 kg/m.sup.3, closed-cell content of 80%, lambda value at 10° C. (measured after 24 h) of 25.8 mW/m.K and calorific value of 2.9 MJ/kg (core foam).

Example 5

[0132] Production of a rigid closed cell polyurethane insulation foam according to the invention filled with 83 wt. % of Bismuth Oxide (Bi.sub.2O.sub.3).
The following chemicals with the respective parts by weight were used for the polyurethane foam cup production: Suprasec 5025 (polymeric MDI from Huntsman, NCOv 31%, 8.15 pbw), Daltolac R411 (polyether polyol from Huntsman, OHv 420, 6.61 pbw), Tegostab B8444 (silicone surfactant from Evonik, 0.16 pbw), water (OHv 6230, 0.036 pbw), Jeffcat DMCHA (N,N-dimethylcyclohexylamine catalyst from Huntsman, 0.175 pbw), Bismuth Oxide Bi.sub.2O.sub.3 fine powder (d90 value <50 micrometers, inorganic filler from Jinwang Europe, bulk density of about 4 g/cm.sup.3, 74.8 pbw, specific volume of about 0.25 L/kg), and Solstice LBA (blowing agent from Honeywell, 5.2 pbw). Isocyanate index was 112.5.
The surfactant, the polyol, the water and the catalyst were first mixed together to prepare a polyol blend. The required mass of polyol blend was weighed in a paper cup (450 mL). The bismuth oxide powder was then added on top followed by the isocyanate and finally the Solstice LBA blowing agent. The entire content of the cup was mixed thoroughly for 10 seconds at 4000 rpm with a Heidolph mixer. The free-rise foam obtained was left to cure at room temperature for 24 hours before further analysis.
The free-rise cup foam had the following properties: core density of 230 kg/m.sup.3 and calorific value of 4.19 MJ/kg.

COMPARATIVE EXAMPLE

[0133] Attempted production of a rigid polyisocyanurate insulation foam panel filled with 90 wt. % of silica quartz sand.
Example 3 is repeated, except that barite sand is replaced by silica quartz sand (d90 value <0.5 mm, inorganic filler from Aldrich, bulk density of about 1.5 g/cm.sup.3, 126 pbw, specific volume of about 0.67 L/kg). Mixing of the various formulation components is extremely difficult due to the high volume of silica sand resulting in inhomogeneous filler distribution within the foam, poor expansion and partially collapsed and coarse cellular structure. No further characterization can be performed.

[0134] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0135] As used herein, the singular forms “a”, “an”, and “the” include both singular and plural referents unless the context clearly dictates otherwise. By way of example, “an isocyanate group” means one isocyanate group or more than one isocyanate group.

[0136] The terms “comprising”, “comprises” and “comprised of” as used herein are synonymous with “including”, “includes” or “containing”, “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms “comprising”, “comprises” and “comprised of” as used herein comprise the terms “consisting of”, “consists” and “consists of”. This means that, preferably, the aforementioned terms, such as “comprising”, “comprises”, “comprised of”, “containing”, “contains”, “contained of”, can be replaced by “consisting”, “consisting of”, “consists”.

[0137] Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.

[0138] As used herein, the terms “% by weight”, “wt %”, “weight percentage”, or “percentage by weight” are used interchangeably.

[0139] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 30 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0140] When the article “a” precedes a wording, such as “a chemical blowing agent”, it also covers more than one of the given wording. The article “a” in this context can therefore by replaced by “at least one” expression.

[0141] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.

[0142] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0143] Throughout this application, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. Although the preferred embodiments of the invention have been disclosed for illustrative purpose, those skilled in the art will appreciate that various modifications, additions or substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.