Macromer for use in polymer polyol dispersions, and method for producing such a macromer

Abstract

The present invention is concerned with a new macromer for use in polymer polyol dispersions, and also with a process for preparing a new macromer of this kind.

Claims

1. A process for preparing a polymer polyol dispersion, comprising reacting at least one macromer with at least one polyether polyol and also styrene and acrylonitrile, using 0.5% to 10% of the macromer, and wherein the macromer is prepared by a process comprising catalytically reacting a hexafunctional polyol P comprising a polyether polyol PM with 1,1-dimethyl-meta-isopropenylbenzyl isocyanate (TMI), using 1.5 to 1.8 mol of the TMI, based on the macromer, and a catalyst K comprising dibutyltin dilaureate (DBTL), wherein the polyol P has been prepared by reacting sorbitol with at least one alkylene oxide with catalysis by a base.

2. The process for preparing a polymer polyol dispersion according to claim 1, wherein the at least one alkylene oxide comprises ethylene oxide (EO), and wherein an EO content of the macromer is between 1% and 25%.

3. The process for preparing a polymer polyol dispersion according to claim 1, wherein more than 1.5 to less than 1.8 mol of the TMI are used, based on the macromer.

4. The process for preparing a polymer polyol dispersion according to claim 1, wherein the polyol P has been prepared by reacting sorbitol with a mixture of ethylene oxide and propylene oxide with catalysis by the base, the fraction of ethylene oxide in the macromer being 1-25 wt %, based on the total mass of the macromer.

5. The process for preparing a polymer polyol dispersion according to claim 1, wherein the polyol P has been prepared by reacting sorbitol with at least one alkylene oxide with catalysis by the base, the basic catalyst being selected from the group consisting of potassium hydroxide and cesium hydroxide.

6. The process for preparing a polymer polyol dispersion according to claim 1, wherein the polyol P has a molecular weight Mw of 5000 to 25 000 g/mol, the molecular weight Mw being determined arithmetically from the OH number, determined according to DIN 53240.

7. The process for preparing a polymer polyol dispersion according to claim 1, wherein the catalyzed reaction with the TMI takes place at a temperature of 60 to 150° C., and a pressure of 0.5 to 2 bar.

8. The process for preparing a polymer polyol dispersion according to claim 1, wherein the macromer has a molecular weight Mw of 5000 to 25 000 g/mol, the molecular weight Mw being determined arithmetically from the OH number, determined according to DIN 53240.

9. A polymer polyol dispersion obtained by the process of claim 1.

10. A process for producing a polyurethane, comprising reacting a polymer polyol dispersion obtained in claim 1 with at least one di- or polyisocyanate and optionally a blowing agent.

11. The process for preparing a polymer polyol dispersion according to claim 1, further comprising filtering the dispersion.

12. The process for preparing a polymer polyol dispersion according to claim 11, wherein the filtering comprises filtering at a filtration rate of 60.9 to 68.9 g per 100 s.

Description

EXAMPLES

(1) A number of examples are indicated below in order to illustrate the invention. These examples are not intended in any way to limit the scope of the invention, but are instead to be understood merely as being illustrative.

(2) The polyetherol 1 is a trifunctional polyetherol based on glycerol as starter with a hydroxyl number of 56 mg KOH/g, determined according to DIN 53240, and prepared by KOH catalysis. The polyetherol 2 used is a hexafunctional polyetherol based on sorbitol as starter with a hydroxyl number of 20.9 mg KOH/g, determined according to DIN 53240, and prepared by CsOH catalysis.

(3) Calculation of the alpha,alpha-dimethyl-meta-isopropenylbenzyl isocyanate (TMI) feed amount The calculation of the amount of TMI used is calculated as follows. Starting from the hydroxyl number of the polyetherol 2 used and from the functionality, the average molar mass is calculated. In this case, the functionality of the polyetherol 2 used is 6 and the hydroxyl number is 20.9 mg of KOH/g. The molar mass is calculated using the following formula, in which z is the functionality of the polyetherol:

(4) $\mathrm{Mn}=1000\mathrm{mg}\text{/}g.Math.\frac{z\mathrm{.56}\mathrm{.106}g\text{/}\mathrm{mol}}{\mathrm{OHN}\left[\mathrm{mg}\text{/}g\right]}$

(5) This gives a calculated molar mass of 16 107 g/mol. This molar mass is used as the basis for calculating the amount of TMI added. The use, for example, of 1 equivalent of the TMI per molecule of polyetherol in the macromer would mean the reaction, for example, of 1 mol of polyetherol with 1 mol of TMI.

(6) General synthesis protocol for macromer preparation, taking macromer number 2 as an example

(7) 500 g of polyetherol 2 were heated to 80° C. in a stirred glass reactor and dried at 8 mbar for 60 minutes. The glass reactor was subsequently inertized, 0.03 g of dibutyltin dilaureate (DBTL) was added, and stirring was continued for 30 minutes. Subsequently, over 30 minutes and at 80° C., 5 g of alpha,alpha-dimethyl-meta-isopropenylbenzyl isocyanate (TMI) were added, corresponding to 0.8 equivalent of TMI per molecule of polyetherol 2. After the end of the addition, stirring at this temperature was continued for 180 minutes. After the stirring time, 0.03 g of 85% phosphoric acid and 4 ml of ethanol were added, and stirring was continued for 30 minutes. This was followed by evacuation at 85° C. and 20 mbar for 60 minutes.

(8) TABLE-US-00001 TABLE 1 Macromers prepared Equivalents of TMI per molecule of polyetherol 2 in the Added amount of Macromer number macromer TMI in g 1 0.5 3.1 2 0.8 5.0 3 1.1 6.9 4 1.3 8.1 5 1.5 9.4 6 1.8 11.2 7 2 12.8 8 2.5 15.6
General Experimental Protocol for the Preparation of Polymer Polyols

(9) 517.2 g of polyetherol 1 were initially charged to a stirred glass reactor, together with 3.06 g of the previously prepared macromer, and this initial charge was heated to 125° C. under an inert gas atmosphere. Subsequently, over 150 minutes, via the first feed stream, 558.79 g of styrene, 279.32 g of acrylonitrile, 8.79 g of dodecanethiol, and 34.61 g of the previously prepared macromer were added and, via a second, 3.92 g of Wako V601 (dimethyl 2,2′-azobis(2-methylpropionate)) in solution in 517.2 g of polyetherol 1 were added. After a reaction time of 15 minutes, the product was freed from residual monomers by application of a vacuum of 15 mbar. The OH number of the products is in the range of 31-33 mg KOH/g KOH.

(10) TABLE-US-00002 TABLE 2 Polymer polyols prepared Macromer Polymer polyol number number Viscosity in mPas 1 1 4586 2 2 4580 3 3 4611 4 4 4543 5 5 4523 6 6 4654 7 7 5008 8 8 gelling
Filtration Results

(11) To investigate the filterability, the above-prepared dispersions were filtered through a 30 μm gap edge filter under a constant superatmospheric pressure of 1 bar at 28° C., and the amount of the filtered material was monitored over time. The higher filtration rate, the more suitable the product is for processing.

(12) TABLE-US-00003 TABLE 3 Filtration results of the polymer polyols is prepared Equivalents of TMI per molecule of Filtration rate Polymer polyol polyetherol in the Measured fil- calculated for number macromer tration rate 100 s 1 0.5  7.8 g in 600 s 1.3 g 2 0.8  77.0 g in 600 s 12.8 g 3 1.1 184.1 g in 600 s 30.7 g 4 1.3 180.4 g in 415 s 43.5 g 5 1.5 188.8 g in 310 s 60.9 g 6 1.8 189.5 g in 275 s 68.9 g 7 2   38 g in 600 s 6.3 g 8 2.5 filtration not filtration not possible possible
Figure 1: Filtration Rates

(13) From this plot it is apparent that in the range between 1.3 and 1.8 TMI per molecule and in particular in the range between 1.5 and 1.8 TMI per molecule, surprisingly, a particularly high filtration rate is possible, and, consequently, the macromers used to achieve this are particularly suitable for the synthesis of graft polyols.