Composition Suitable for Preparing Polyurethane- or Polyisocyanurate Rigid Foams

Abstract

A process for producing polyurethane foam by reacting at least one polyol component with at least one isocyanate component in the presence of at least one blowing agent and of one or more catalysts that catalyze the isocyanate-polyol and/or isocyanate-water reactions and/or the isocyanate trimerization, wherein the reaction is conducted in the presence of selected polyether-siloxane copolymers, is described.

Claims

1. A process for producing polyurethane foam by reacting at least one polyol component with an isocyanate component in the presence of a blowing agent and of one or more catalysts that catalyze the isocyanate-polyol and/or isocyanate-water reactions and/or the isocyanate trimerization, wherein the reaction is conducted in the presence of polyether-siloxane copolymer of the formula (I)
M.sub.aD.sub.bD.sub.c (I) with ##STR00003## R.sup.1=independently identical or different hydrocarbyl radicals having 1 to 16 carbon atoms or H, R.sup.2=independently R.sup.1 or R.sup.3, R.sup.3polyether radicals of the general formula (II),
R.sup.4O[C.sub.2H.sub.4O].sub.d[C.sub.3H.sub.6O].sub.eR.sup.5 (II), R.sup.4=identical or different divalent hydrocarbyl radicals which have 1 to 16 carbon atoms and may be interrupted by oxygen atoms,
CH.sub.2.sub.f R.sup.5=independently identical or different hydrocarbyl radicals which have 1 to 16 carbon atoms and may optionally be interrupted by urethane functions, C(O)NH, carbonyl functions or C(O)O, or H, preferably methyl, C(O)Me or H, with a=2, a+b+c=10 to 200, b/c=7 to 60, d and e=numerical mean values which arise from the following provisos: with the provisos that the molar mass (numerical average M.sub.n) of the individual polyether radicals R.sup.3=600 to 2000 g/mol, that at least one R.sup.3 radical present has a molar mass formed to an extent of 27% to 60% by mass, from [C.sub.3H.sub.6O] units, that the percentage siloxane content in the polyether-siloxane copolymer is 35% to 60% by mass, by mass.

2. The process according to claim 1, wherein R.sup.2=R.sup.3.

3. The process according to claim 1, wherein the polyurethane foam is a rigid polyurethane foam.

4. The process according to claim 1, wherein the polyether siloxanes of the formula I are used in a total proportion by mass of 0.1 to 10 parts based on 100 parts by mass of polyol component.

5. The process according to claim 1, wherein at least 90 parts by weight of the polyols present, based on 100 parts by weight of polyol component, have an OH number greater than 100.

6. The process according to claim 1, wherein hydrocarbons having 3, 4 or 5 carbon atoms, such as, cyclo-, iso- and/or n-pentane, hydrofluorocarbons, hydrochlorofluorocarbons, hydrohaloolefins.

7. The polyurethane foam, especially rigid polyurethane foam, obtainable by a process according to claim 1.

8. The polyurethane foam according to claim 7, wherein the closed cell content is 80%, preferably the closed cell content being determined according to DIN ISO 4590.

9. A thermal insulation for cooling technology comprising the polyurethane foam according to claim 7 wherein the thermal insulation is used in cooling technology selected from the group consisting of refrigerators, freezers, an insulation panel, sandwich element, pipe insulation, vessel, tank walls for cryogenic storage at temperatures <50 C., for insulation of vessel and/or tank walls for cold storage at temperatures of 50 C. to 20 C., as a constituent of cryogenic insulation systems, liquefied gas tanks or conduits, tanks or conduits for automotive gas (LPG), liquid ethylene (LEG) or liquefied natural gas (LNG).

10. The thermal insulation according to claim 9 in the form of sprayable foam, which is applied directly to the surface to be insulated and/or filled and/or introduced into appropriate cavities.

11. A method of lowering the thermal conductivity of polyurethane foams, especially rigid polyurethane foams, in the temperature range of 200 C. to 10 C., by using polyether-siloxane copolymer of the formula (I) in the production of the polyurethane foam, in an amount of 0.1 to 10 parts, based on 100 of parts isocyanate-reactive polyol component, where the addition can be effected before and/or during the production of the polyurethane foam.

12. A rigid polyurethane foam made by the process of claim 1 wherein the rigid polyurethance foam has improved insulation performance within the temperature range of 200 C. to 10 C.

13. The process according to claim 1 wherein R.sup.1=methyl, R.sup.4=a radical of the general formula (III)
CH.sub.2.sub.f(III), with f=1 to 8, a+b+c=20 to 50, b/c=15 to 50, d and e=numerical mean values which arise from the following provisos: with the provisos that the molar mass (numerical average M.sub.n) of the individual polyether radicals R.sup.3=800 to 1700 g/mol, that at least one R.sup.3 radical present has a molar mass formed to an extent of 35% to 45% by mass from [C.sub.3H.sub.6O] units, that the percentage siloxane content in the polyether-siloxane copolymer is 45% to 50% by mass.

14. The process according to claim 1, wherein the polyether siloxanes of the formula I are used in a total proportion by mass of 1 to 3 parts, based on 100 parts by mass of polyol component.

15. The process according to claim 1, wherein at least 90 parts by weight of the polyols present, based on 100 parts by weight of polyol component, have an OH number greater than 200.

16. The process according to claim 1, wherein at least 90 parts by weight of the polyols present, based on 100 parts by weight of polyol component, have an OH number greater than 150.

17. The process according to claim 1, further comprising a blowing agent selected from the group consisting of n-pentane, hydrofluorocarbons, hydrochlorofluorocarbons, and hydrohaloolefins.

18. The process according to claim 1, further comprising a blowing agent selected from the group consisting of trans-l-chloro-3,3,3-trifluoropropene and cis-1,1,1,4,4,4-hexafluoro-2-butene.

19. The process according to claim 1, further comprising a blowing agent selected from the group consisting of methyl formate, acetone, dimethoxymethane, dichloromethane and 1,2-dichloroethane.

20. The polyurethane foam according to claim 7, wherein the closed cell content is 90% the closed cell content being determined according to DIN ISO 4590.

Description

EXAMPLES

[0055] Rigid polyurethane foams have been produced in order to examine the use of various inventive and noninventive foam stabilizers in the process claimed. For this purpose, the formulation according to Table 1 was used.

TABLE-US-00001 TABLE 1 No. Component Function Parts used 1 Stepanpol PS 2352 Polyol 100.0 2 Tris(2-chloroisopropyl) phosphate (TCPP) Flame 15.0 retardant 3 KOSMOS 75 Metal 3.5 catalyst 4 KOSMOS 33 Metal 1.0 catalyst 5 Tegoamin PMDETA Amine 0.2 catalyst 6 Water Blowing 0.3 agent 7 n- iso- n-/iso- Solstice Blowing 20.0 20.0 20.0 36.2 pentane pentane pentane 1233zd agent (50:50%) (E) 8 Stabilizer 1-8 Foam 2.0 stabilizer 9 Lupranate M70L Isocyanate 180.0

[0056] The foaming operations were conducted with a KraussMaffei RIM-Star MiniDos high-pressure foaming machine with a MK12/18ULP-2KVV-G-80-I mixing head, and a KraussMaffei Microdos additive dosage system. Components 1-7 were in the polyol reservoir vessel; the foam stabilizer 8 was dosed directly into the polyol stream in the mixing head with the Microdos dosage system. The use temperature of the polyol blend was 30 C., that of the isocyanate component 9 was 25 C., and isocyanate/polyol blend ratio was 1.268. The liquid foam mixture was injected into a metal mold having internal dimensions of 50 cm.Math.50 cm.Math.5 cm that had been heated to 40 C. and left therein until the foam had set. Two specimens having dimensions of 20 cm.Math.20 cm.Math.0.5 cm were cut out of the foam molding thus obtained and used for the measurements of the thermal conductivities. The values used are each averages from these two measurements. The thermal conductivities of the specimens were measured in a LaserComp Heat Flow Meter instrument.

[0057] The stabilizers used for the examples are listed in Table 2.

TABLE-US-00002 TABLE 2 % by wt. of % by wt. of Inventive? R.sup.2 a + b + c b/c M.sub.n of R.sup.3 PO in R.sup.3 R.sup.5 siloxane Stabilizer 1 yes R.sup.3 50 15 1000 40 H 42 Stabilizer 2 yes CH.sub.3 30 10 1000 40 CH.sub.3 46 Stabilizer 3 yes CH.sub.3 30 15 1000 40 H 56 Stabilizer 4 yes CH.sub.3 30 10 700 40 H 55 Stabilizer 5 yes R.sup.3 30 30 700 40 H 52 Stabilizer 6 no CH.sub.3 50 5 700 40 H 39 (comparative) Stabilizer 7 no CH.sub.3 50 10 700 20 H 55 (comparative) Stabilizer 8 no CH.sub.3 30 10 700 0 H 55 (comparative)

Example 1

[0058] The formulation from Table 1 was foamed as specified therein with 20 parts n-pentane as blowing agent. The foam stabilizers used were stabilizers 2, 3 and 5 (inventive), and stabilizers 6 and 7 were used as noninventive comparative examples. The measurements for temperature-dependent thermal conductivities shown in table 3 (all thermal conductivity figures in mW/m.Math.K) were obtained.

TABLE-US-00003 TABLE 3 (all thermal conductivity figures in mW/m .Math. K) Temperature ( C.) 5 0 5 10 15 20 25 30 35 40 Stabilizer 2 (inv.) 24.28 22.87 21.69 21.72 21.81 22.12 22.34 22.71 22.88 23.19 Stabilizer 3 (inv.) 24.02 22.74 21.65 21.63 21.76 21.93 22.21 22.53 22.70 22.96 Stabilizer 5 (inv.) 23.67 22.69 21.53 21.57 21.73 22.10 22.28 22.51 22.71 23.09 Stabilizer 6 (comp.) 24.41 23.51 22.41 21.79 21.91 22.20 22.42 22.67 22.81 23.21 Stabilizer 7 (comp.) 24.39 23.53 22.51 21.85 21.87 22.24 22.47 22.59 22.75 23.14

[0059] It can be inferred from the table that the foams produced with the inventive foam stabilizers 2, 3 and 5 have lower thermal conductivity with decreasing measurement temperature than the foams comprising the noninventive stabilizers 6 and 7. The minimum of the thermal conductivity plot has moved to lower temperatures and a better insulation performance at comparable temperature is obtained.

Example 2

[0060] The formulation from Table 1 was foamed as specified therein with 20 parts isopentane as blowing agent. The foam stabilizers used were candidates 1 and 4 (inventive) and candidate 8 as a noninventive comparative example. The measurements for temperature-dependent thermal conductivities shown in table 4 (all thermal conductivity figures in mW/m.Math.K) were obtained.

TABLE-US-00004 TABLE 4 (all thermal conductivity figures in mW/m .Math. K) Temperature ( C.) 5 0 5 10 15 20 25 30 35 40 Stabilizer 1 (inv.) 24.1 22.57 21.53 21.54 21.67 22.02 22.13 22.51 22.75 22.88 Stabilizer 4 (inv.) 23.85 22.44 21.41 21.50 21.59 21.84 22.18 22.43 22.61 22.81 Stabilizer 8 (comp.) 24.33 23.48 22.21 21.67 21.83 22.11 22.24 22.53 22.74 22.95

[0061] It can be inferred from the table that the foams produced with the inventive foam stabilizers 1 and 4 have lower thermal conductivity with decreasing measurement temperature than the foams comprising the noninventive stabilizer 8. The minimum of the thermal conductivity plot has moved to lower temperatures and a better insulation performance at comparable temperature is obtained.

Example 3

[0062] The formulation from Table 1 was foamed as specified therein with 20 parts of a mixture of 50% n-pentane and 50% isopentane as blowing agent. The foam stabilizers used were candidates 2, 3 and 5 (inventive), and candidates 6 and 7 were used as noninventive comparative examples. The measurements for temperature-dependent thermal conductivities shown in table 5 (all thermal conductivity figures in mW/m.Math.K) were obtained.

TABLE-US-00005 TABLE 5 (all thermal conductivity figures in mW/m .Math. K) Temperature ( C.) 5 0 5 10 15 20 25 30 35 40 Stabilizer 2 (inv.) 23.89 22.69 21.52 21.55 21.69 22.00 22.19 22.62 22.71 23.05 Stabilizer 3 (inv.) 23.94 22.7 21.55 21.51 21.62 21.85 22.21 22.52 22.65 22.81 Stabilizer 5 (inv.) 23.57 22.61 21.49 21.45 21.58 22.01 22.28 22.51 22.55 23.04 Stabilizer 6 (comp.) 24.35 23.21 22.52 21.69 21.77 22.01 22.32 22.56 22.81 23.02 Stabilizer 7 (comp.) 24.28 23.5 22.59 21.81 21.81 21.97 22.37 22.52 22.63 23.08

[0063] It can be inferred from the table that the foams produced with the inventive foam stabilizers 2, 3 and 5 have lower thermal conductivity with decreasing measurement temperature than the foams comprising the noninventive stabilizers 6 and 7. The minimum of the thermal conductivity plot has moved to lower temperatures and a better insulation performance at comparable temperature is obtained.

Example 4

[0064] The formulation from Table 1 was foamed as specified therein with 36.2 parts Solstice 1233zd (E) from Honeywell as blowing agent. The foam stabilizers used were candidates 1, 2 and 4 (inventive), and candidates 6 and 7 were used as noninventive comparative examples. The measurements for temperature-dependent thermal conductivities shown in table 6 (all thermal conductivity figures in mW/m.Math.K) were obtained.

TABLE-US-00006 TABLE 6 (all thermal conductivity figures in mW/m .Math. K) Temperature ( C.) 5 0 5 10 15 20 25 30 35 40 Stabilizer 1 (inv.) 18.78 17.59 17.5 17.82 18.33 18.83 19.21 19.47 19.8 20.08 Stabilizer 2 (inv.) 18.95 17.5 17.52 18.03 18.42 18.74 19.01 19.37 19.66 19.95 Stabilizer 4 (inv.) 19.11 17.47 17.61 17.92 18.35 18.78 18.98 19.53 19.76 19.99 Stabilizer 6 (comp.) 19.62 18.29 17.88 17.96 18.4 18.7 19.1 19.45 19.69 19.89 Stabilizer 7 (comp.) 19.76 18.17 17.83 17.87 18.31 18.69 18.85 19.55 19.86 20.13

[0065] It can be inferred from the table that the foams produced with the inventive foam stabilizers 1, 2 and 4 have lower thermal conductivity with decreasing measurement temperature than the foams comprising the noninventive stabilizers 6 and 7. The minimum of the thermal conductivity plot has moved to lower temperatures and a better insulation performance at comparable temperature is obtained.