Isocyanate trimerization catalyst for making polyisocyanurate comprising foams

Abstract

A trimerization catalyst composition suitable for making a polyisocyanurate comprising (insulation) foam, said composition comprising at least a trimerization catalyst compound selected from one or more organic salts from alkoxides wherein said organic salt is selected from alkali metal, earth alkali metal, a transition metal such as Ti and/or quaternary ammonium organic salts.

Claims

1. A process for making polyisocyanurate-polyurethane rigid foam (PIR-PUR), having a free rise density between 25 kg/m.sup.3 up to 100 kg/m.sup.3, a compression hardness at 10% strain between 80 and 300 kPa (measured in three dimensions according to ISO844), and a thermal conductivity in the range of 20 mW/mK up to 30 mW/mK, said process comprising combining and mixing at an isocyanate index of at least 180 or higher: a) a polyisocyanate composition comprising one or more polyisocyanate compounds; b) an isocyanate reactive compound selected from a monool, a polyol and a mixture thereof; c) a trimerization catalyst selected from potassium ethoxide, sodium ethoxide, potassium methoxide, sodium methoxide, potassium tert-butoxide, titanium isopropoxide, and a mixture thereof; d) optionally one or more surfactants, one or more flame retardants, water, one or more antioxidants, one or more auxiliary blowing agents, one or more urethane catalysts, one or more auxiliary trimerisation catalysts, or combinations thereof; and wherein the rigid foam exhibits a smooth rise profile during curing, wherein the trimerization catalyst is present in an amount such that the number of trimerization catalyst equivalents over the number of isocyanate equivalents ranges in an amount from 0.001 to 0.4, and wherein, when present, the one or more auxiliary blowing agents is not a hydrofluorocarbon or a hydrochlorofluorocarbon compound.

2. The process according to claim 1, wherein the trimerization catalyst is present in a solvent.

3. The process according to claim 1, wherein the trimerization catalyst and the isocyanate reactive compound are present in the solvent.

4. The process according to claim 1, wherein polyol is selected from a polyester polyol, a polyether polyol, and a combination thereof wherein the polyester polyol and polyether polyol have an average molecular weight of 32-6000 and an average nominal functionality of 1-8.

5. The process according to claim 1, wherein the number of trimerization catalyst equivalents over the number of isocyanate equivalents ranges from 0.01 to 0.24.

6. The process according to claim 1, wherein the polyisocyanate compounds are selected from a toluene diisocyanate, a methylene diphenyl diisocyanate and a mixture thereof.

7. The process according to claim 1, wherein the monools and polyols have an average nominal hydroxy functionality of 1-8 and an average molecular weight of 32-8000.

8. The process according to claim 1, wherein the monool is selected from methanol, ethanol, propanol, butanol, phenol, cyclohexanol, and a hydrocarbon monool having an average molecular weight of 200-5000, and the polyol is selected from ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylol propane, sorbitol, sucrose, glycerol, ethanediol, propanediol, butanediol, pentanediol, hexanediol, an aromatic polyol having a molecular weight of up to 8000, an aliphatic polyol having a molecular weight of up to 8000, a polyester polyol having an average molecular weight of 200-8000, a polyether polyester polyol having an average molecular weight of 200-8000, and a polyether polyol having an average molecular weight of 200-8000.

9. The process according to claim 1, wherein the auxiliary blowing agent is selected from isobutene, dimethyl ether, water, methylene chloride, acetone, chlorofluorocarbons (CFCs), hydrocarbons and a mixture thereof and wherein the auxiliary blowing agent is present in an amount of 1 to 80 parts by weight (pbw), calculated per hundred weight parts of the one or more isocyanate reactive compounds (including the weight contribution of a catalyst system diluent).

10. A polyisocyanurate-polyurethane comprising rigid foam material obtainable by the process according to claim 1.

11. The polyisocyanurate-polyurethane comprising rigid foam material according to claim 10, having a free rise density (measured according to ISO 845) in the range of between 25 kg/m.sup.3 up to 60 kg/m.sup.3, a thermal conductivity in the range 20 up to 30 mW/mK, and having a closed cell content higher than 75% calculated on the total amount of closed and open cells being present in the rigid foam material.

Description

FIGURES

(1) FIG. 1 illustrates the PIR/PUR ratio in the core for a polyisocyanurate comprising insulation foam fabricated according to the present invention and for a polyisocyanurate comprising insulation foam not fabricated according to the invention (comparative) using an isocyanate index of 265 and 300.

(2) FIG. 2 illustrates the PIR/PUR ratio in the skin for a polyisocyanurate comprising insulation foam fabricated according to the present invention and for a polyisocyanurate comprising insulation foam not fabricated according to the invention (comparative) using an isocyanate index of 265 and 300.

(3) FIG. 3 illustrates the increase in PIR conversion in the core and the skin for a polyisocyanurate comprising insulation foam fabricated using an isocyanate index of respectively 265 (example 1) and 300 (example 2) according the according to the present invention compared to a polyisocyanurate comprising insulation foam not according to the invention fabricated using an isocyanate index of 265 and 300 (wherein the comparative foam is taken as 100%).

EXAMPLES

(4) Chemicals Used:

(5) Suprasec® 2085 polyisocyanate ex Huntsman, in the examples indicated as S2085

(6) Flame retardant Tris chloroisopropyl phosphate (TCPP)

(7) Tegostab® B8484 ex Evonik, polyether modified polysiloxane-copolymer

(8) Catalyst Dabco® K15 ex Air Products, Potassium octoate in Diethylene glycol

(9) Catalyst Cat LB ex Huntsman Potassium Acetate/Ethyleneglycol/water

(10) Sodium Ethoxide ex Sigma Aldrich, 21% pure in ethanol

(11) Daltolac® R251 ex Huntsman PO polyol, glycerol initiated OHv=250 mg KOH/g

(12) Water

(13) N-Pentane ex Emplura

(14) Catalyst PMDETA ex Huntsman, Pentaethyldiethylenetriamine

(15) Suprasec®, Daltolac® and Daltocel® are trademarks of the Huntsman Corporation or an Affiliate thereof and have been registered in one or more but not all countries.

Example 1: Fabrication of a Polyisocyanurate Comprising Insulation Foam Using Isocyanate Index 265

(16) Two polyisocyanurate comprising insulation foams were fabricated using an isocyanate index of 265. The foam according the according to the present invention was prepared using Na-ethoxide as a trimerization catalyst (example 1). For the comparative foam 1, Cat LB and Dabco® K15 was used as a trimerisation catalyst.

(17) Table 1 summarizes the amounts of ingredients used in pbw (part by weight) to fabricate example 1 according to the present invention using Na-ethoxide as a trimerization catalyst and to fabricate comparative foam 2 using Cat LB and Dabco® K15 as a trimerisation catalyst, both at an isocyanate index of 265.

(18) TABLE-US-00001 TABLE 1 Comparative 1 Invention (example 1) pbw pbw S2085 190 198 Daltolac ® R251 100 100 TCCP 15 15.4 Tegostab ® B 8484 2 2.06 PMDETA 0.25 0.27 Cat LB 0.40 — Dabco ® K15 2.20 — Sodium ethoxide (21%) — 2.03 Water 0.50 0.51 n-pentane 19 19.6 ISO index 265 265 Free Rise Density (kg/m.sup.3) 58 56 End of rise (s) 127 132 Cream Time (s) 14 13

(19) FIG. 1 illustrates the PIR/PUR ratio in the core for example 1 and for the comparative example fabricated using an isocyanate index of 265. The increase in PIR conversion for example 1 compared to the comparative example 1 is significant.

(20) FIG. 2 illustrates the PIR/PUR ratio in the skin of the foam for example 1 and for the comparative example fabricated using an isocyanate index of 265. The increase in PIR conversion for example 1 in the skin compared to the comparative example 1 is significant and surprising.

(21) FIG. 3 illustrates the increase in PIR conversion in the core and the skin for a polyisocyanurate comprising insulation foam fabricated using an isocyanate index of respectively 265 (example 1a) according the according to the present invention compared to a polyisocyanurate comprising insulation foam not according to the invention fabricated using an isocyanate index of 265 and 300 (wherein the comparative foam is taken as 100%).

Example 2 Fabrication of a Polyisocyanurate Comprising Insulation Foam Using Isocyanate Index 300

(22) Two polyisocyanurate comprising insulation foams were fabricated using an isocyanate index of 300. The foam according the according to the present invention was prepared using Na-ethoxide as a trimerization catalyst (example 2). For the comparative foam 2, Cat LB and Dabco® K15 was used as a trimerisation catalyst.

(23) Table 2 summarizes the amounts of ingredients used in pbw (part by weight) to fabricate the example 2 according to the present invention using Na-ethoxide as a trimerization catalyst and to fabricate the comparative foam 2 using Cat LB and Dabco® K15 as a trimerisation catalyst, both at an isocyanate index of 300.

(24) TABLE-US-00002 TABLE 2 Comparative 2 Invention (example 2) pbw pbw S2085 218 228 Daltolac ® R251 100 100 TCCP 16.4 16.9 Tegostab ® B 8484 2.2 2.3 PMDETA 0.3 0.3 Cat LB 0.4 — Dabco ® K15 2.4 — Sodium ethoxide (21%) — 2.2 Water 0.5 0.6 n-pentane 21 21.6 ISO index 300 300 Free Rise Density (kg/m.sup.3) 56 61 End of rise (s) 133 115 Cream Time (s) 17 12

(25) FIG. 1 illustrates the PIR/PUR ratio in the core for example 2 and for the comparative example fabricated using an isocyanate index of 300. The increase in PIR conversion for example 2 compared to the comparative example 2 is significant.

(26) FIG. 2 illustrates the PIR/PUR ratio in the skin of the foam for example 1 and for the comparative example fabricated using an isocyanate index of 300. The increase in PIR conversion for example 2 in the skin compared to the comparative example 2 is still significant and surprising.

(27) FIG. 3 illustrates the increase in PIR conversion in the core and the skin for a polyisocyanurate comprising insulation foam fabricated using an isocyanate index of respectively 300 (example 1) according the according to the present invention compared to a polyisocyanurate comprising insulation foam not according to the invention fabricated using an isocyanate index of 300 (wherein the comparative foam is taken as 100%).