Method for producing polyurethane rigid foams and polyisocyanurate rigid foams

Abstract

The present invention relates to polyester polyols obtainable or obtained by esterification of 10 to 70 mol % of at least one compound from the group consisting of terephthalic acid (TPA), dimethyl terephthalate (DMT), polyethylene terephthalate (PET), phthalic anhydride (PA), phthalic acid and isophthalic acid, 0.1 to 30 mol % of one or more fatty acids and/or fatty acid derivatives, 10 to 70 mol % of one or more aliphatic or cycloaliphatic diols having 2 to 18 carbon atoms or alkoxylates thereof, 5 to 70 mol % of a polyether polyol prepared by alkoxylating an aromatic starter molecule having a functionality of not less than 2, and of 0 to 70 mol % of a tri- or polyol other than the polyether polyol, all based on the total amount of the components used, wherein the amounts used of the components add up to 100 mol %. The present invention further relates to a process for producing rigid polyurethane or polyisocyanurate foams which comprises reacting an isocyanate component with a polyol component (PK) comprising a polyester polyol of the present invention and further components, to the polyol component as such and also to the rigid polyurethane or polyisocyanurate foams obtainable or obtained by a process of the present invention. The present invention also relates to the method of using a polyester polyol (P1) of the present invention in the manufacture of rigid polyurethane foams or rigid polyisocyanurate foams.

Claims

1. A polyester polyol (P1) obtained by esterification of components (i) to (v): (i) 10 to 70 mol % of at least one compound from the group consisting of terephthalic acid (TPA), dimethyl terephthalate (DMT), polyethylene terephthalate (PET), phthalic anhydride (PA), phthalic acid and isophthalic acid, (ii) 0.1 to 30 mol % of one or more fatty acids and/or fatty acid derivatives, (iii) 10 to 70 mol % of one or more aliphatic or cycloaliphatic diols having 2 to 18 carbon atoms or alkoxylates thereof, (iv) 5 to 70 mol % of a polyether polyol prepared by alkoxylating an aromatic starter molecule having a functionality of not less than 2, (v) 0 to 70 mol % of a tri- or polyol other than component (iv), all based on a total amount of components (i) to (v), wherein the amounts used of components (i) to (v) add up to 100 mol %.

2. The polyester polyol (P1) according to claim 1, wherein said components (i) to (v) are used in the following amounts: component (i) in an amount from 25 to 40 mol %, component (ii) in an amount from 8 to 14 mol %, component (iii) in an amount from 25 to 55 mol %, component (iv) in an amount from 12 to 18 mol %, and component (v) in an amount from 0 to 18 mol %, all based on the total amount of components (i) to (v), wherein the amounts used of components (i) to (v) add up to 100 mol %.

3. The polyester polyol (P1) according to claim 1, wherein said component (i) is selected from the group consisting of terephthalic acid and dimethyl terephthalate (DMT).

4. The polyester polyol (P1) according to claim 1, wherein said component (ii) is selected from the group consisting of oleic acid, soya oil, rapeseed oil and tallow.

5. The polyester polyol (P1) according to claim 1, wherein said component (iii) is selected from the group consisting of diethylene glycol (DEG) and monoethylene glycol (MEG).

6. The polyester polyol (P1) according to claim 1, wherein said component (iv) is obtained by ethoxylating an aromatic polyol having a functionality of greater than 2.

7. The polyester polyol (P1) according to claim 1, wherein said component (iv) is obtained by ethoxylating a composition consisting of tolylenediamine isomers and comprising not less than 90 wt % of tolylenediamine isomers having a vicinal position for the two amino groups.

8. The polyester polyol (P1) according to claim 1, wherein said polyester polyol (P1) has a number average molecular weight in the range from 450 g/mol to 800 g/mol.

9. A process for producing rigid polyurethane foams or rigid polyisocyanurate foams, the process comprising: reacting A) a component (A) comprising at least one compound selected from the group consisting of organic diisocyanates, modified organic diisocyanates, organic polyisocyanates and modified organic polyisocyanates, with B) a polyol component (PK), comprising: (b1.1) at least one polyester polyol (P1) according to claim 1, (b2) at least one flame retardant, (b3) at least one blowing agent, and (b4) at least one catalyst.

10. The process according to claim 9, wherein said polyol component (PK) further comprises one or more of the following compounds: (b1.2) at least one polyester polyol (P2) other than said polyester polyol (P1), (b1.3) at least one compound selected from the group consisting of polyether polyols (P3), compounds having two or more isocyanate-reactive groups, chain-extending agents and crosslinking agents, (b5) further auxiliaries and/or admixture agents.

11. The process according to claim 10, wherein a mass ratio of a sum total of polyester polyols (P1) and (P2) to a sum total used of polyether polyols (P3) is not less than 0.1.

12. The process according to claim 10, wherein said polyol component (PK) comprises no further polyester polyol (P2) in addition to said polyester polyol (P1).

13. The process according to claim 10, wherein the polyether polyol component of (b1.3) comprises polyethylene glycol only and no further polyether polyols are used.

14. The process according to claim 9, wherein the flame retardant component (b2) comprises tris(2-chloropropyl) phosphate (TCPP) only and no further flame retardants are used.

15. The process according to claim 9, wherein the blowing agent (b3) comprises chemical and physical blowing agents, wherein the chemical blowing agent is selected from the group consisting of water, formic acid-water mixtures and formic acid and the physical blowing agent consists of one or more pentane isomers.

16. A polyol component (PK), comprising: (b1.1) 50 to 90 wt % of polyester polyol (P1) according to claims 1, (b1.2) 0 to 20 wt % of at least one polyester polyol (P2), (b1.3) 2 to 9 wt % of at least one polyether polyol (P3), (b2) 5 to 30 wt % of at least one flame retardant, (b3) 1 to 30 wt % of at least one blowing agent, (b4) 0.5 to 10 wt % of at least one catalyst, and (b5) 0.5 to 20 wt % of further auxiliary and admixture agents, all based on a total weight of polyol component (PK), wherein the weight percentages add up to 100 wt %, and wherein a mass ratio of a sum total of polyester polyols (P1) and (P2) to a sum total used of polyether polyols (P3) is not less than 2.

Description

EXAMPLES

(1) 1. The following polyols and catalyst mixtures were used:

(2) 1.1 Polyesterol 1 (comparative sample):

(3) Esterification product of terephthalic acid (32 5 mol %), oleic acid (9.0 mol %), diethylene glycol (26.0 mol %) and a polyether (32.5 mol %) based on glycerol and ethylene oxide having an OH functionality of 3 and a hydroxyl number of 705 mg KOH/g. The polyesterol has a hydroxyl functionality of 2.9 and a hydroxyl number of 250 mg KOH/g.

(4) 1.2 Polyesterol 2 (in Accordance with the Present Invention):

(5) Esterification product of terephthalic acid (30.3 mol %), oleic acid (10.6 mol %), diethylene glycol (40.9 mol %) and a polyether (18.2 mol %) based nn tolylenediamine (TDA) comprising 98 wt % of isomers having a vicinal position of the two amino groups relative to each other and ethylene oxide having an OH functionality of 4 and a hydroxyl number of 452 mg KOH/g. The polyesterol has a hydroxyl functionality of 2.9 and a hydroxyl number of 241 mg KOH/g.

(6) 1.3 Polyether Polyol 1:

(7) Polyetherol formed from ethoxylated ethylene glycol and having a hydroxyl functionality of 2 and a hydroxyl number of 190 mg KOH/g.

(8) 1.4 Catalyst Mixture 1:

(9) 47 wt % of potassium acetate, 50.15 wt % of monoethylene glycol and 2.85 wt % of water.

(10) 1.5 Catalyst Mixture 2:

(11) 70 wt % of bis(2-dimethylaminoethyl) ether and 30 wt % of dipropylene glycol.

(12) 2. Comparative Example 1

(13) A polyol component was prepared from 80.0 parts by weight of polyesterol 1, 8.0 parts by weight of polyether polyol 1, 10.0 parts by weight of tris-2-ehloroisopropyl phosphate (TCPP) and 2.0 parts by weight of a silicone-containing foam stabilizer (Tegostab B 8443 from Goldschmidt) by mixing.

(14) The polyol component was phase stable at 20 C. It was reacted with 200 parts by weight of a polymer MDI having an NCO content of 31.5 wt % (Lupranat M50 from BASF SE) in the presence of 8 parts by weight of n-pentane (8.0 parts by weight), 2 parts by weight of catalyst mixture 1, by varying catalyst mixture 2 and water such that the fiber time was 421 seconds and the resulting foam had a density of 39.01 kg/m.sup.3.

(15) 3. Example 1

(16) A polyol component was prepared from 80.0 parts by weight of polyesterol 2, 8.0 parts by weight of polyether polyol 1, 10.0 parts by weight of tris-2-chloroisopropyl phosphate (TCPP) and 2.0 parts by weight of a silicone-containing foam stabilizer (Tegostab B 8443 from Goldschmidt) by mixing.

(17) The polyol component was phase stable at 20 C. It was reacted with 200 parts by weight of a polymer MDI having an NCO content of 31.5 wt % (Lupranat M50 from BASF SE) in the presence of 8 parts by weight of n-pentane (8.0 parts by weight), 2 parts by weight of catalyst mixture 1, by varying catalyst mixture 2 and water such that the fiber time was 421 seconds and the resulting beaker foam had a density of 39.01 kg/m.sup.3.

(18) 4. Measurement of Average and Peak Rates of Heat Release by Cone Calorimetry

(19) The test specimens used for cone calorimetry were cut out of the slab foams at identical places. The reaction mixture used to produce the slab foams led in beaker foams to the abovementioned fiber times of 421 seconds and the beaker foam densities of 39.01 kd/m.sup.3 and was reacted in identical amounts [5 g] in a slab mold 25 cm in length, 15 cm in width and 21 cm in height.

(20) Cone calorimetry was used to determine heat release and mass loss similarly to ISO 5660-1 Part 1. For this, the test specimens were tested in horizontal alignment using a radiation intensity of 50 kW/m.sup.2. The results are summarized in table 1.

(21) TABLE-US-00001 TABLE 1 Comparative Example 1 Example 1 polyester polyol 1 parts by wt 80 polyester polyol 2 parts by wt 80 tris-2-chlorisopropyl parts by wt 10 10 phosphate polyether polyol 1 parts by wt 8 8 Tegostab B 8443 parts by wt 2 2 Lupranat M50 parts by wt 200 200 catalyst mixture 1 parts by wt 2 2 catalyst mixture 2 parts by wt 2 1.8 water parts by wt 2 1.8 n-pentane parts by wt 8 8 beaker density kg/m.sup.3 38.9 38.8 fiber time s 42 41 ignition s 3 3 average heat 60 s after kW/m.sup.2 75.2 67.9 release ignition 180 s after kW/m.sup.2 59.5 46.8 ignition 300 s after kW/m.sup.2 47.7 39.1 ignition 360 s after kW/m.sup.2 44.2 35.6 ignition PRHR after MJ/m.sup.2 74.6 71.7 ignition

(22) Both foams ignite 3 seconds after the start of the test. Surprisingly, the foam of Example 1 consistently has a significantly lower average rate of heat release than the foam of

(23) Comparative Example 1 after each of 1, 3, 5 and 6 minutes.

(24) Similarly, the peak rate of heat release [PRHR] in Example 1 is lower than in Comparative Example 1.

(25) Not only the lower average rates of heat releas but also the lower PRHR demonstrate that the foam of Example 1 is distinctly superior to the foam of Comparative Example 1 in the event of a fire.