POLYETHERESTERS AND THEIR USE IN RIGID POLYURETHANE FOAMS

Abstract

A polyol component b) comprising: 20 to 40 wt % of polyetherester polyols B) having a functionality of 3.8 to 4.8, an OH number of 380 to 440 mg KOH/g and a fatty acid and/or fatty acid ester content of 8 to 17 wt %, based on the weight of polyetherester polyols B); 20 to 40 wt % of polyether polyols C) having a functionality of 3.7 to 4 and an OH number of 300 to 420 mg KOH/g; 20 to 40 wt % of one or more polyether polyols D) having a functionality of 4.5 to 6.5 and an OH number of 400 to 520 mg KOH/g; 0.5 to 5.5 wt % of catalysts E), 0.1 to 5 wt % of further auxiliaries and/or added-substance materials F), 0.5 to 5 wt % of water G);
and also rigid polyurethane foams obtained therewith and use thereof for insulation and refrigeration applications.

Claims

1. A polyol component b) comprising: 25 to 35 wt % of one or more polyetherester polyols B) having a functionality of 3.8 to 4.8, an OH number of 380 to 440 mg KOH/g and a fatty acid and/or fatty acid ester content of 8 to 17 wt %, based on a total weight of the polyetherester polyols B); 25 to 35 wt % of one or more polyether polyols C) having a functionality of 3.7 to 4 and an OH number of 300 to 420 mg KOH/g; 25 to 35 wt % of one or more polyether polyols D) having a functionality of 4.5 to 6.5 and an OH number of 400 to 520 mg KOH/g; 1.0 to 5 wt % of one or more catalysts E); 0.1 to 5 wt % of auxiliaries and/or added-substance materials F); and 0.5 to 5 wt % of water G), wherein a sum total of components B), C), D), E), F) and G) is 100 wt %.

2. The polyol component according to claim 1, wherein: said polyetherester polyol B) has a mean functionality of 4.0 to 4.7, an OH number of 390 to 430 and a fatty acid and/or fatty acid ester content of 10 to 16 wt % based on the total weight of the polyetherester polyols B); said polyether polyol C) has a mean functionality of 3.9 to 4.1 and an OH number of 350 to 410 mg KOH/g; and said polyether polyol D) has a mean functionality of 4.8 to 6.2 and an OH number of 400 to 480 mg KOH/g.

3. The polyol component according to claim 1, wherein: said polyetherester polyol B) has a mean functionality of 4.0 to 4.7, an OH number of 410 to 430 and a fatty acid and/or fatty acid ester content of 11 to 15 wt % based on the total weight of the polyetherester polyols B).

4. The polyol component according to claim 1, wherein: said polyether polyol C) is an alkoxylated tolylenediamine and said polyether polyol D) is an alkoxylated sucrose-glycerol mixture.

5. The polyol component according to claim 1, wherein: said polyetherester polyol B) comprises the reaction product of a sucrose-glycerol starter mixture with biodiesel or oleic acid methyl ester and one or more alkylene oxides having 2 to 4 carbon atoms.

6. (canceled)

7. The polyol component according to claim 1, comprising: 27 to 32 wt % of the polyetherester polyols B), 27 to 32 wt % of the polyether polyols C), 27 to 32 wt % of the polyether polyols D), 1 to 3 wt % of the catalysts E), 1 to 3 wt % of the auxiliary and/or added-substance materials F), and 1.5 to 3 wt % of water G), wherein the sum total of components B) to G) is 100 wt %.

8. A process for preparing rigid polyurethane foams, comprising: reacting I) organic or modified organic di- or polyisocyanates A) or mixtures thereof, with II) the polyol component according to claim 1 after addition thereto of a blowing agent H).

9. A rigid polyurethane foam obtained by the process according to claim 8.

10. A rigid polyurethane foam comprising the polyol component according to claim 1.

11. The rigid polyurethane foam according to claim 9, wherein the rigid polyurethane foam is comprised in an insulation or refrigeration composition.

Description

EXAMPLES

[0121] Methods of Measurement:

[0122] Measurement of Hydroxyl Number: Hydroxyl numbers were determined according to DIN 53240 (1971-12).

[0123] Viscosity Determination:

[0124] Unless otherwise stated, polyol viscosity was determined at 25 C. in accordance with DIN EN ISO 3219 (1994) using a Rheotec RC 20 rotary viscometer and the CC 25 Din spindle (spindle diameter: 12.5 mm, measuring cylinder inside diameter: 13.56 mm) at a shear rate of 50 1/s.

[0125] Determination of Pentane Solubility:

[0126] To evaluate its pentane solubility, polyol component b) is mixed (Vollrath stirrer, 1500 rpm, 2 min stirring time) with the amount which was reported in the examples for physical blowing agent H), and the mixture is poured into a screw-top jar which is then closed. Following complete escapage of gas bubbles, sample clarity is initially assessed at room temperature. If the sample is clear, it is subsequently cooled down in a water bath in increments of 1 C. and assessed for clarity 30 min after reaching the temperature setting.

[0127] Determination of Demolding Behavior:

[0128] Demolding behavior was determined by measuring the postexpansion of foam bodies produced using a 70040090 mm box mold at a mold temperature of 452 C. as a function of demolding time and the degree of overpacking (OP), which corresponds to the ratio of overall apparent density/minimum fill density. Postexpansion was determined by measuring the foam cuboids after 24 h.

[0129] Minimum Fill Density for a Component Part/Free Rise Density:

[0130] Minimum fill density is determined by importing just sufficient polyurethane reaction mixture into a mold measuring 200020050 mm at a mold temperature of 452 C. to just fill the mold. Free rise density is determined by allowing the foaming polyurethane reaction mixture to expand in a plastic bag at room temperature. The density is determined on a cube removed from the center of the foam-filled plastic bag.

[0131] Determination of Flowability:

[0132] The flowability is reported in terms of the flow factor=(minimum fill density/free rise density).

[0133] Thermal Conductivity:

[0134] Thermal conductivity was determined using a Taurus TCA300 DTX at a midpoint temperature of 10 C. To prepare the test specimens, the polyurethane reaction mixture was imported into a 200020050 mm mold with 15% overpacking and demolded 5 min later. After aging for 24 hours under standard conditions, several foam cuboids (at positions 10, 900 and 1700 mm on the lower end of the Brett molding) measuring 20020050 mm are cut out of the center. The top and bottom sides were then removed to obtain test specimens measuring 20020030 mm.

[0135] Compressive Strength:

[0136] Compressive strength was determined according to DIN ISO 844 EN DE (2014-11).

EXAMPLES

[0137] Starting Materials:

[0138] Biodiesel as per the EN 14214 (2010) standard

[0139] Preparation of Polyether Polyol C

[0140] A 600 l pressure reactor equipped with stirrer, jacket heating and cooling, metering devices for solid and liquid substances and alkylene oxides and also devices for nitrogen inertization and a vacuum system was heated up to 80 C. and repeatedly inertized. 120.2 kg of vicinal tolylenediamine were introduced into the reactor and the stirrer was switched on. Then, the reactor was inertized once more and the temperature was raised to 130 C. and 160.06 kg of propylene oxide were metered in. Following a reaction of 2 h, the temperature was lowered to 100 C. and 4.29 kg of dimethylethanolamine were added. The intermediate product was reacted with a further 233.97 kg of propylene oxide. The postreaction ran for 2 hours at 100 C. to obtain 508.6 kg of product having the following parameters:

TABLE-US-00001 OH number 399 mg KOH/g Viscosity (at 25 C.) 17016 mPas

[0141] Preparation of Polyether Polyol D3

[0142] A reactor as described above for polyether polyol C) was charged with 21.20 kg of glycerol, 136.49 kg of sucrose and 1.03 kg of an aqueous imidazole solution (50 weight percent in water). The stirrer was started and the reactor was repeatedly inertized and heated to 120 C. Then, 361.1 kg of propylene oxide were metered into the reactor. The postreaction of 2 hours proceeded at 120 C. The propylene oxide still present was stripped off in a stream of nitrogen. The product (498.3 kg) had the following parameters:

TABLE-US-00002 OH number 432 mg KOH/g Viscosity (at 25 C.) 26871 mPas.

[0143] Preparation of Polyetherester Polyol B1

[0144] 53.60 kg of glycerol, 0.47 kg of an aqueous imidazole solution (50 weight percent), 90.53 kg of sucrose and 70.24 kg of biodiesel were charged at 25 C. to a reactor as described above for polyether polyol C). The reactor was subsequently inertized with nitrogen three times. The tank was heated to 130 C. and 305.41 kg of propylene oxide were metered in. Following a reaction time of 3 h, the reactor was evacuated to a full vacuum at 100 C. for 60 minutes and then cooled down to 25 C. to obtain 502.4 kg of product.

TABLE-US-00003 OH number 415 mg KOH/g Viscosity (at 25 C.) 3215 mPas

[0145] Acid number: 0.01 mg KOH/g

[0146] The following components were converted into polyols similarly to the above methods of synthesis (all particulars in wt %):

[0147] Polyol B1: polyetheresterol based on sucrose 17.4%, glycerol 10.3%, propylene oxide (PO) 58.7% and biodiesel 13.5%, OH number 415 mg KOH/g;

[0148] Polyol B2 (not in accordance with the present invention): polyetheresterol based on sucrose 12.04%, glycerol 12.7%, propylene oxide (PO) 41.2% and methyl oleate 25.6%, OH number 489 mg KOH/g;

[0149] Polyol C: polyetherol based on vic-TDA and PO, OH number 399 mg KOH/g;

[0150] Polyol X1 (not in accordance with the present invention): polyetherol based on vic-TDA, ethylene oxide (EO) and PO, OH number 160 mg KOH/g.

[0151] Polyol X2 (not in accordance with the present invention): polyetherol based on glycerol and PO, OH number 160 mg KOH/g.

[0152] Polyol X3 (not in accordance with the present invention): polyetherol based on sucrose, OH number 340 mg KOH/g analogous to Multranol 9171 from Covestro (used as polyol Z in EP 2 029 711 A1).

[0153] Polyol X4: polyetherol based on vic-TDA, analogous to Multranol 8120 from Covestro (used as polyol Yin EP 2 029 711 A1).

[0154] Polyol D1: polyetherol based on sucrose, glycerol and PO, OH number 450 mg KOH/g, functionality: 5.0.

[0155] Polyol D2: polyetherol based on sucrose, glycerol and PO, OH number 411 mg KOH/g, functionality: 6.0.

[0156] Polyol D3: polyetherol based on sucrose, glycerol and PO, OH number 432 mg KOH/g, functionality: 6.0.

[0157] Stabilizer F): silicone-containing foam stabilizer, Tegostab B8474 and/or Tegostab B8491 from Evonik

[0158] Catalyst mixture E) consisting of:

[0159] catalyst E1): dimethylcyclohexylamine

[0160] catalyst E2): pentamethyldiethylenetriamine

[0161] catalyst E3): tris(dimethylaminopropyl)hexahydro-1,3,5-triazine

[0162] catalyst E4): dimethylbenzylamine

[0163] The aforementioned catalyst mixture E) was used in Examples 1 to 3 and in Comparative Examples 1, 2, 4 and 5 (see table 1). The catalyst mixture of Comparative Example 3 (as per WO 2013/127647, table 2, Example 3) only contains the catalysts E1), E2) and E3).

[0164] Isocyanate: polymer MDI having an NCO content of 31.5 wt % (Lupranat M20)

[0165] The aforementioned raw materials were used to prepare a polyol component (all particulars in wt %) which was mixed with a physical blowing agent before foaming. A PU 30/80 IQ high pressure Puromat (Elastogran GmbH) operating at an output rate of 250 g/s was used to mix the polyol component, which had been admixed with the physical blowing agent, with the requisite amount of the reported isocyanate to obtain an isocyanate index (unless otherwise stated) of 117. The reaction mixture was injected into molds temperature regulated to 40 C. and measuring 2000 mm200 mm50 mm and/or 400 mm700 mm90 mm and allowed to foam up therein. Overpacking was 14.5%, i.e., 14.5% more reaction mixture than needed to completely foam out the mold was used.

[0166] Table 1 shows the measured results for the particular composition of the polyol component (PC) b) (particulars in wt %) and the foams resulting therefrom. The amount of physical blowing agent (cyclopentane) is reported in the parts by weight added to 100 parts by weight of the polyol component.

TABLE-US-00004 TABLE 1 Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 1 Ex. 2* Ex. 3* Ex. 4* Ex. 5* polyol B1 31.5 31.5 31.5 28.6 0 31.5 46.0 polyol B2 0 0 0 0 0 60 0 0 polyol D1 31.0 0 0 29.0 56.0 0 0 0 polyol C 30.0 30.0 30.0 30.0 23.0 30 30.0 0 polyol X1 0 0 0 5.0 0 0 0 0 polyol D2 0 31.0 0 0 0 0 0 0 polyol D3 0 0 31.0 0 0 0 0 0 polyol X2 0 0 0 0 13.5 0 0 0 polyol X3 0 0 0 0 0 0 31.0 28 polyol X4 0 0 0 0 0 0 0 18.5 stabilizer 2.8 2.8 2.8 2.8 2.8 2.75 2.8 2.8 H.sub.2O 2.6 2.6 2.6 2.6 2.6 2.55 2.6 2.6 catalyst mixture 2.1 2.1 2.1 2.0 2.1 E1) 0.44 2.1 2.1 E2) 0.71 E3) 0.35 Sum total 100 100 100 100 100 100 100 Cyclopentan 95 (CP 95) 13.5 13.5 13.5 13.5 13.5 13 13.5 13.5 NCO index 117 117 117 117 117 118 117 117 fiber time [s] 41 42 40 42 41 37 40 41 free rise density [g/L] 22.6 22.5 22.7 22.2 22.0 23.4 21.8 22.7 PC stability with CP 95 at RT clear clear clear clear clear clear clear clear PC stability with CP 95 at 6 C. clear clear clear clear clear clear clear clear postexpansion [%] 14.5% over-packing [%] 3 min 4.0 3.6 2.8 4.2 4.0 3.11 3.6 4.3 4 min 2.3 2.0 1.5 2.5 2.6 1.78 2.1 2.8 compressive strength [N/mm.sup.2] 0.157 0.155 0.157 0.143 0.148 0.144 0.149 0.143 at 31 g/L density *= Comparative Example 2 corresponds to EP-A 1 138 709. *= Comparative Example 3 corresponds to WO 2013/127647 A1. *= Comparative Examples 4 and 5 correspond to EP 2 039 711 A1.

[0167] Comparative Example 1 (Comp. Ex. 1) shows a polyol component formulation which is not in accordance with the present invention in comprising polyols B1, C and D1, which are used in accordance with the present invention, and additionally a polyether alcohol X1 having a functionality of 4 and a hydroxyl number of 160 mg KOH/g. The rigid PU foams obtained are inferior to those obtained in Example 1 in demolding and also, by 9%, in compressive strength.

[0168] Comparative Example 2 shows a customary refrigerator formulation comprising a polyether alcohol X2 having a functionality of 4 and a hydroxyl number of 160 mg KOH/g as per EP 1 138 709 A1. Comparing the rigid PU foams obtained, it is clear that the products as per Example 1 have a 6% improved compressive strength and also improved demolding at 4 min.

[0169] Comparative Example 3 used a formulation of a polyol component as per Example 3 of WO 2013/127647 A1, comprising a polyetheresterol B2, which was not in accordance with the present invention, and a polyetherol C. The compressive strength of the rigid PU foam obtained is 6-8% worse than that of the product from Examples 1 to 3.

[0170] The formulations of the polyol components in Examples 2 and 3 utilized respectively polyetherols D2 and D3, based on sucrose-glycerol and having a higher functionality. The rigid PU foams obtained are notable for better demolding in particular.

[0171] Comparative Example 4 used a formulation of a polyol component, comprising beside polyols B) and C), which are used in accordance with the present invention, polyol X3analogous to polyol Z (Multranol 9171) as per EP-A 2 039 711which is not used in accordance with the present invention. The compressive strength of the rigid PU foam obtained is 4 to 5% worse than that of the product from Examples 1 to 3. The rigid PU foams obtained are also inferior to those obtained in Examples 2 and 3 in demolding.

[0172] Comparative Example 5 shows a formulation of a polyol component comprising polyol B1) which is used in accordance with the present invention, and polyols X3 and X4 which are analogous to polyols Z (Multranol 9171) and Y (Multranol 8120) as per EP-A 2 039 711 (cp. Example 7). The rigid PU foams obtained are inferior to those obtained in Examples 1 to 3 in demolding and also, by 8 to 9%, in compressive strength.