Polyol component and use thereof for producing rigid polyurethane foams

Abstract

A polyol component P) contains at least three different polyether polyols A) to C). A method produces rigid polyurethane foams using the polyol component P), and the rigid polyurethane foams produced therefrom are useful.

Claims

1-20. (canceled)

21: A polyol component P) comprising: a) 35 to 70 wt %, based on a total amount of components A) to G1) of the polyol component P), of one or more polyether polyols A) having an OH number in the range from 300 to 520 mg KOH/g, and a functionality in the range from 4.6 to 6.5, selected from the group consisting of reaction products of monosaccharides, oligosaccharides, polysaccharides, polyhydric alcohols, alkoxylation products of the aforesaid compounds, or mixtures thereof with alkylene oxides; b) one or more polyether polyols B) with an OH number in the range from 320 to 500 mg KOH/g, selected from the group consisting of reaction products of aromatic diamines with alkylene oxides; c) one or more polyether polyols C) having an OH number in the range from 15 to 75 mg KOH/g, selected from the group consisting of reaction products of monosaccharides, oligosaccharides, polysaccharides, polyhydric alcohols, water or mixtures thereof with alkylene oxides; d) optionally, one or more polyols D) which are different from the one or more polyether polyols A), B) and C); e) optionally, one or more catalysts E); f) optionally, one or more further components F) selected from the group consisting of auxiliaries and adjuvants; and g) optionally, one or more blowing agents selected from the group consisting of chemical blowing agents G1) and physical blowing agents G2).

22: The polyol component P) according to claim 21, wherein the one or more polyether polyols B) has a functionality in the range from 3.0 to 4.0.

23: The polyol component P) according to claim 21, wherein the one or more polyether polyols B) is selected from the group consisting of reaction products of 2,3-, 3,4-, 2,4-, 2,5-, 2,6-tolylenediamine or mixtures thereof with C.sub.2-C.sub.4 alkylene oxides.

24: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) has a functionality in the range from 2.3 to 5.5.

25: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) has a functionality in the range from 2.5 to 4.5.

26: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) has a functionality in the range from 2.3 to 5.5, and wherein the one or more polyether polyols B) has an OH number in the range from 380 to 450 mg KOH/g.

27: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) has a functionality in the range from 2.3 to 5.5 and is selected from the group consisting of reaction products of monosaccharides, oligosaccharides, polysaccharides, polyhydric alcohols, water or mixtures thereof with ethylene oxide and propylene oxide.

28: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) is selected from the group consisting of reaction products of monosaccharides, oligosaccharides, polysaccharides, polyhydric alcohols or mixtures thereof with ethylene oxide and propylene oxide.

29: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) is selected from the group consisting of reaction products of glycerol, trimethylolpropane, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, pentaerythritol, sorbitol, sucrose, water or mixtures thereof with C.sub.2-C.sub.4 alkylene oxides.

30: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) comprises 5 to 35 wt % of ethylene oxide units, based on a total weight of the one or more polyether polyols C).

31: The polyol component P) according to claim 21, wherein the one or more polyether polyols C) has the following structure: ##STR00002## wherein S is selected from the group consisting of monosaccharides, oligosaccharides, polysaccharides, water, and polyhydric alcohols, n is 2 to 10, and B in each case, independently of one another at each occurrence, is a chain composed of ethylene oxide and propylene oxide units, wherein the ethylene oxide and the propylene oxide units form pure ethylene oxide blocks, pure propylene oxide blocks and/or mixed blocks of ethylene oxide and propylene oxide, and wherein a terminal block comprises 10 to 100 wt % of ethylene oxide units, based on the total weight of the terminal block.

32: The polyol component P) according to claim 21, wherein a concentration of the one or more polyether polyols C) is at least 2 wt %, based on the total amount of components A) to G1) of the polyol component P).

33: The polyol component P) according to claim 21, comprising: a) 35 to 70 wt % of the one or more polyether polyols A); b) 5 to 50 wt % of the one or more polyether polyols B); c) 2 to 30 wt % of the one or more polyether polyols C); d) 0 to 40 wt % of the one or more polyols D); e) optionally, the one or more catalysts E); f) optionally, the one or more further components F) selected from the group consisting of auxiliaries and adjuvants; and g) optionally, the one or more blowing agents selected from the group consisting of chemical blowing agents G1) and physical blowing agents G2); wherein the concentration figures in wt % for components A) to D) are based on the total amount of components A) to G1) of the polyol component P).

34: The polyol component P) according to claim 21, wherein the polyol component P) comprises at least one further polyol D) selected from the group consisting of polyether polyols D1) having an OH number in the range from 100 to 240 mg KOH/g, wherein the polyether polyols D1) are selected from the group consisting of reaction products of amines, polyhydric alcohols or mixtures thereof with alkylene oxides.

35: The polyol component P) according to claim 21, wherein the polyol component P) comprises at least one further polyol D1) selected from the group consisting of polyether polyols having an OH number in the range from 100 to 240 mg KOH/g, and wherein the at least one further polyol D1) is selected from the group consisting of reaction products of amines, polyhydric alcohols or mixtures thereof with alkylene oxides, wherein a total concentration of the one or more polyether polyols C) and the at least one further polyol D1) is at least 5 wt %, based on the total amount of components A) to G1) of the polyol component P).

36: A method for producing a rigid polyurethane foam, the method comprising: reacting I) di- or polyisocyanates PI) or a mixture thereof, with II) the polyol component P) according to claim 21.

37: A rigid polyurethane foam obtainable by the method according to claim 36.

38: A method, comprising: reacting the polyol component P) according to claim 21, to produce a rigid polyurethane foam.

39: A method, comprising: producing a rigid polyurethane foam according to the method of claim 36 for an insulating or cooling application.

Description

EXAMPLES

[0164] I. Methods of Measurement:

[0165] Measurement of Hydroxyl Number:

[0166] The hydroxyl numbers are determined in accordance with DIN 53240 (1971-12).

[0167] Viscosity Determination:

[0168] The viscosity of the polyols is determined, unless otherwise indicated, at 25° C. in accordance with DIN EN ISO 3219 (1994), using a Haake Viscotester 550 or a Brookfield CAP2000 with plate/cone measuring geometry (PK100) using the cone PK 1 1° (diameter: 28 mm; cone angle: 1°) at a shear rate of 40 1/s.

[0169] Determination of Demolding Behavior:

[0170] The demolding behavior is determined by measuring the post-expansion of foam bodies produced using a 700×400×90 mm box mold at a mold temperature of 45±2° C. depending on the demolding time and the degree of overpacking (OP, corresponding to the ratio of overall apparent density/minimum fill density, and describing the percentage extra amount of starting materials actually required in order just to fill the mold with a rigid PU foam. The experimental examples described herein were carried out with an OP of 17.5%.). The post-expansion is determined by measuring the height of the foam cuboids after 24 h.

[0171] Start Time:

[0172] Time from the commencement of the mixing of the reaction mixture until the start of foam expansion.

[0173] Setting Time (Gel Time/Fiber Time)

[0174] The time from the commencement of the mixing of the reaction mixture up to the time until which fibers can be drawn in contact with the foam (using a wooden rod, for example). This point therefore represents the transition from the liquid to the solid state.

[0175] Minimum Fill Density for a Component Part/Free Rise Density:

[0176] Minimum fill density is determined by introducing an amount of polyurethane reaction mixture into a mold measuring 2000×200×50 mm at a mold temperature of 45±2° C. to just fill the mold with the foam without being in contact with the end of the mold. The length of the flow path is measured, and the minimum fill density is calculated according to MFD=(m*L/(V*s)), where m=mass, L=length of mold, s=flow path, and V=volume of mold. The free rise density is determined by foaming the polyurethane reaction mixture into a plastic bag at room temperature. The density is determined on a cube taken from the center of the foam-filled plastic bag.

[0177] Determination of Flowability:

[0178] The flowability is reported in terms of the flow factor=(minimum fill density/free rise density).

[0179] Adhesion:

[0180] A test body is taken from the specimen body. This test body corresponds to the first 50 cm, as considered starting from the sprue, of the lance molding, with an overpacking of 14.5%. Using a stencil, the aluminum foil on the top face is cut in to a width of 56 mm and a length of 200 mm, and a lug of approximately 50 mm is lifted from the foam. This lug is clamped into the sample holder of the universal testing machine. When the test time is reached, measurement is commenced. The measured force for peeling the aluminum foil from the foam is output in newtons (N). Adhesion values intended for comparison with other foam formulations must be measured under identical foaming and testing conditions. To test the limit of the adhesion of the covering foil on the foam, the mold temperature is lowered in steps of 5° C., specimens are foamed, and the adhesion is measured on these specimens. The adhesion limit is reached when the cover layer detaches from the foam already when the specimen is being demolded.

[0181] Thermal Conductivity:

[0182] The thermal conductivity is determined using a Taurus TCA300 DTX instrument at a midpoint temperature of 10° C. To produce the test specimens, the polyurethane reaction mixture is introduced into a mold measuring 2000×200×50 mm (15% overpacking) and demolded after 5 minutes. Following storage under standard conditions for 24 hours, a number of foam cuboids (at positions 10, 900 and 1700 mm, based on the start of the lance) with dimensions of 200×200×50 mm are cut out of the center. The top and bottom sides are then removed, to give test specimens with dimensions of 200×200×30 mm.

[0183] II. Preparation of the Polyols:

[0184] Polyether Polyol A1) and A2):

[0185] A pressure reactor 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 filled with glycerol, sucrose, solid imidazole and, for polyol A1), with a polyether polyol based on sucrose, glycerol and propylene oxide (with OH number of 490 mg KOH/g, functionality: 4.3). The reactor was then repeatedly inertized (with stirring) and the temperature was raised to 120° C. The mixture was reacted with propylene oxide at 120° C. The 2-hour after-reaction took place at 120° C. The sample was subsequently stripped off in a stream of nitrogen.

[0186] Example for Computing the Functionality from the Polyether Polyol A1)

[0187] 12.3 kg of glycerol, 90.70 kg of sucrose, 0.34 kg of solid imidazole and 29.00 kg of the polyether polyol based on sucrose, glycerol and propylene oxide (molecular weight 488 g/mol, functionality 4.3) were reacted with 256.3 kg of propylene oxide to give 372 kg of product with the following parameters:

[0188] OH number: 429 mg KOH/g

[0189] Viscosity (25° C.): 34 600 mPas

[0190] Computation of starter functionality:

[0191] Glycerol (functionality 3): 12 300 g/92.09 g/mol=132.4 mol

[0192] Sucrose (functionality 8): 90 700 g/342.3 g/mol=246.97 mol

[0193] Imidazole (functionality 1): 340 g/68.08 g/mol=5.0 mol

[0194] Polyether polyol (functionality 4.3): 29 000 g/488 g/mol=59.4 mol

[0195] Starter functionality: (132.4 mol*3+246.97 mol*8+5.0 mol*1+59.4 mol*4.3)/(132.4 mol+246.97 mol+5.0 mol+59.40 mol)=6.0

[0196] Composition (Percent by Mass):

TABLE-US-00001 Sucrose 23.3% Glycerol  3.2% Polyether polyol  7.5% Propylene oxide 66.0%

[0197] Polyether Polyol B1):

[0198] A pressure reactor 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 to 80° C. and repeatedly inertized. The reactor was charged with vic-toluenediamine and the stirrer was put into operation. The reactor was then inertized again and the temperature was raised to 130° C., and propylene oxide was metered. After a 2-hour reaction period, the temperature was lowered to 100° C. and dimethylethanolamine was added. The intermediate was reacted with further propylene oxide. The after-reaction ran for 2 hours at 130° C. The sample was subsequently stripped off in a stream of nitrogen.

[0199] Polyether Polyols C1) and C2):

[0200] Polyetherol C1

[0201] A pressure reactor 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 filled with 11.59 kg of glycerol and 1 kg of aqueous KOH (48% by mass). The reactor was then repeatedly inertized (with stirring), the temperature was raised to 120° C., and reduced pressure was applied (15 mbar) for 1 hour. Then 106.70 kg of propylene oxide were metered. In the next step, a mixture of 234.81 kg of propylene oxide and 46.76 kg of ethylene oxide was metered in. The after-reaction of 2 hours took place at 120° C. The sample was subsequently stripped off in a stream of nitrogen and worked up with Magnesol. This gave a product having the following parameters:

[0202] OH number: 56 mg KOH/g

[0203] Viscosity (25° C.): 480 mPas

[0204] Polyetherol C2

[0205] A pressure reactor 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 filled with 9.19 kg of glycerol and 1 kg of aqueous KOH (48% by mass). The reactor was then repeatedly inertized (with stirring), the temperature was raised to 120° C., and reduced pressure was applied (15 mbar) for 1 hour. Then 337.31 kg of propylene oxide were metered. In the next step, 53.15 kg of ethylene oxide were metered in. The after-reaction of 2 hours took place at 120° C. The sample was subsequently stripped off in a stream of nitrogen and worked up with Magnesol. This gave a product having the following parameters:

[0206] OH number: 35 mg KOH/g

[0207] Viscosity (25° C.): 850 mPas

[0208] Polyether Polyol D1):

[0209] A pressure reactor 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 to 80° C. and repeatedly inertized. Vicinal toluenediamine was added and the reactor was repeatedly inertized. The temperature was raised to 130° C. and the mixture at this temperature was admixed with a mixture of ethylene oxide and propylene oxide (EO:PO=1:15). After a 2-hour reaction period, a 50% aqueous KOH solution (percent by mass) was added. This was followed by a reduced pressure phase of 1 hour, after which, at 130° C., a mixture of ethylene oxide and propylene oxide (EO:PO=1:15) was metered in. After a 3-hour reaction period, the sample was stripped off in a stream of nitrogen.

[0210] III. Ingredients

[0211] Polyols A) to D) were prepared as described above. [0212] Polyol A1): polyether polyol based on sucrose, glycerol and propylene oxide (PO) with OH number of 427 mg KOH/g; functionality: 6.0 [0213] Polyol A2): polyether polyol based on sucrose, glycerol and PO with OH number of 450 mg KOH/g; functionality: 5.0 [0214] Polyol 1): polyether polyol based on vic-TDA and PO with OH number of 399 mg KOH/g; functionality: 4.0 [0215] Polyol C1): polyether polyol based on glycerol, propylene oxide and ethylene oxide (EO), the alkylene oxide chains being composed of a PO and a terminal mixed PO/EO block, where the EO fraction in the polyether polyol is 11.7 wt %, based on the polyether polyol, and the EO fraction in the terminal PO/EO block is 16.6 wt %, based on the terminal block; OH number: 56 mg KOH/g; functionality: 3.0 [0216] Polyol C2): polyether polyol based on glycerol, propylene oxide and ethylene oxide, where the alkylene oxide chains are composed of a PO and an EO block, where the EO fraction in the polyether polyol is 13.3 wt %, based on the polyether polyol, and the EO fraction in the terminal EO block is 100 wt %, based on the terminal block; OH number: 35 mg KOH/g; functionality: 3.0 [0217] Polyol D1): polyether polyol based on vic-TDA, propylene oxide and ethylene oxide with OH number of 160 mg KOH/g; functionality: 4.0

[0218] Catalyst mixture E) consisting of:

[0219] Catalyst E1): dimethylcyclohexylamine

[0220] Catalyst E2): pentamethyldiethylenetriamine or bis(2-dimethylaminoethyl) ether

[0221] Catalyst E3): tris(dimethylaminopropyl)hexahydro-1,3,5-triazine

[0222] Catalyst E4): dimethylbenzylamine

[0223] Stabilizer F):

[0224] Silicone-containing foam stabilizer, Tegostab® B8474 and/or Tegostab® B8491 from Evonik

[0225] Physical Blowing Agent G2)

[0226] Cyclopentane 95 (CP 95): cyclopentane with 95% purity

[0227] Furthermore, each polyol component was additionally admixed with 13.5 wt % of cyclopentane 95, based on the total weight of the polyol components A) to G1).

[0228] Isocyanate:

[0229] Polymeric MDI with an NCO content of 31.5 wt % (Lupranat® M20)

[0230] IV. Rigid PU Foams

[0231] The aforesaid ingredients were used to produce polyol components P) to which a physical blowing agent was added prior to foaming. A PU 30/80 IQ high-pressure Puromaten® (Elastogran GmbH) with an output rate of 250 g/s was used to mix the polyol components P), which had been admixed with the physical blowing agent, with the requisite amount of the specified isocyanate in each case, so as to obtain the desired isocyanate index.

[0232] The reaction mixture was injected into molds temperature-regulated to 40° C. with dimensions of 2000 mm×200 mm×50 mm or 400 mm×700 mm×90 mm, and allowed to foam up in the molds. Overpacking was 17.5%, i.e., 17.5% more reaction mixture was used than was needed to fully foam out the mold.

[0233] Table 1 shows the polyol components P used and the results of measurement for the rigid PU foams produced therefrom. From the results it is evident that rigid PU foams produced with polyol components P) of the invention exhibit an improved combination of advantageous properties in respect of demoldability (apparent in the tables from lower figures for post-expansion), heat insulation and, in particular, improved adhesion.

TABLE-US-00002 TABLE 1 Exam- Com- Exam- Com- Exam- Com- ple para- ple para- ple para- 1 tive 1 2 tive 2 3 tive 3 Polyol component P Polyol A1 50.2 50.7 — — 41.2 45.2 Polyol A2 — — 47.8 47.8 — — Polyol B1 30.0 30.0 35.0 35.0 41.2 45.2 Polyol C1 10 — — — 8.0 — Polyol C2 — — 3.00 — — — Polyol D1 — 9.3 5.00 8.0 — — Propylene carbonate 2.0 2.0 1.0 1.0 2.0 2.0 Catalyst mixture E 2.5 2.5 3.0 3.0 2.1 2.1 Stabilizer F 3.0 3.0 3.0 3.0 3.0 3.0 Water 2.3 2.5 2.2 2.2 2.5 2.5 Total 100 100 100 100 100 100 Cyclopentane 95 13.5 13.5 13.5 13.5 13.5 13.5 Isocyanate I Isocyanate 100 100 100 100 100 100 NCO index 120 120 120 120 120 120 Machine data Start time [s] 4 4 5 6 5 4 Setting time [s] 41 39 45 42 40 38 Free rise density [g/L] 22.6 22.2 22.9 23.1 22.5 22.0 Minimum fill density 30.3 30.0 31.9 30.8 30.3 30.8 [g/L] Thermal conductivity 20.0 19.8 19.8 19.9 19.5 19.7 [mW/mK] Adhesion (45° C. mold 8.5 5.0 7.0 6.3 4.5 3.0 temperature) [N] Adhesion (40° C. mold 8.0 4.1 6.7 5.1 2.8 1.1 temperature) [N] Post-expansion (determined by a 90 mm box mold with overpacking of 17.5%) 3 min 3.7 3.9 3.1 3.4 2.7 2.7 4 min 2.0 2.3 1.8 2.0 1.5 1.6 5 min n.d. n.d. 0.7 0.9 0.6 0.5