PROCESS FOR PREPARING A DISPERSION OF INORGANIC OXIDE PARTICLES IN POLYESTER POLYOL

Abstract

A process for preparing a dispersion of inorganic oxide particles in polyester polyol by mechanically mixing of the inorganic oxide particles at a temperature of more than 160° C. with a polyester polyol having an acid number in the range of from 0.05 to 1.5.

Claims

1-17. (canceled)

18. A process for preparing a dispersion of inorganic oxide particles in polyester polyol, the process comprising mechanically mixing inorganic oxide particles at a temperature of more than 160° C. with a polyester polyol having an acid number in a range of from 0.05 to 1.5, wherein the inorganic oxide particles are added to the polyester polyol, after preparing the polyester polyol.

19. The process of claim 18, wherein the temperature is at least 165° C.

20. The process of claim 18, wherein the inorganic oxide particles have a surface comprising hydroxyl groups.

21. The process of claim 18, wherein the inorganic oxide is selected from oxidic silicon particles.

22. The process of claim 21, wherein the inorganic oxide is selected from silicates.

23. The process of claim 18, wherein the polyester polyol has an acid number in a range of from 0.1 to 1.0.

24. The process of claim 18, wherein the polyester polyol has a hydroxyl number in a range of from 10 to 150.

25. The process of claim 18, wherein the inorganic oxide particles have a number average particle size d.sub.50 of lower than 50 μm.

26. The process of claim 18, wherein the polyester polyol has a molecular weight (M.sub.n) of from 500 to 30000 g/mol.

27. A dispersion of inorganic oxide particles in polyester polyol, obtainable by mechanically mixing oxidic silicon particles having a number average particle size d.sub.50 being an arithmetic or number mean diameter (d) in a range of from 0.5 to 24 μm at a temperature of more than 160° C. with a polyester polyol having an acid number in a range of from 0.05 to 1.5, wherein the oxidic silicon particles are added to the polyester polyol, after preparing the polyester polyol.

28. A polyester polyol dispersion comprising a polyester polyol having an acid number in a range of from 0.05 to 1.5 reacted with oxidic silicon particles having a number average particle size d.sub.50 being an arithmetic or number mean diameter (d) in a range of from 0.5 to 24 μm at a temperature of more than 160° C. with a polyester polyol having an acid number in a range of from 0.05 to 1.5, wherein the oxidic silicon particles are added to the polyester polyol, after preparing the polyester polyol.

29. A process for preparing a polyurethane, the process comprising obtaining the dispersion of claim 27.

30. A process for preparing a polyurethane, the process comprising: mixing the dispersion of claim 27 with a polyisocyanate and optionally one or more selected from the group consisting of further compounds having hydrogen atoms which are reactive towards isocyanates, chain extenders and/or crosslinkers, catalysts, blowing agents and further additives, to obtain a mixture; and reacting the mixture to form the polyurethane.

31. The process of claim 30, wherein the polyurethane is a polyurethane foam and the mixture comprises a blowing agent.

32. The process of claim 30, wherein the polyurethane is a compact polyurethane material.

33. A polyurethane, obtainable by the process of claim 30.

Description

EXPERIMENTAL PART

[0071] Acid-values were determined following DIN 53402 in its actual (2018) version.

[0072] OH-values were determined following DIN 53240 from 2012.

[0073] Particle distribution analysis has been carried out by laser diffraction using a Mastersizer® 2000 (Malvern Instruments Ltd). The distributions are given as volume distribution.

[0074] Viscosity values were determined following DIN EN ISO 3219 from 1994 (temperature and shear rate are indicated for each value).

EXAMPLES

Example 1: 20 wt % Alumina Silicate in Polyesterol 1

[0075] 100 g sodium aluminium silicate (Sipernat® 820 A of Evonik) is added to 400 g of polyesterol with primary hydroxyl end groups based on adipic acid, monoethylene glycol and diethylene glycol with a molecular weight of 2000 g/mol, OH-value of 56 mg.sub.KOH/g.sub.polymer a viscosity of 500 mPas at 75° C. and an acid-value of 0.8 mg.sub.KOH/g.sub.polymer (Lupraphen® of BASF SE). The reaction mixture is heated up to 180° C. under vigorous stirring (400 rpm) and further stirred for 1 h. The product is released at 120° C. It was not possible to detect the viscosity at 25° C. Therefore, the viscosity was measured at 75° C. to be 2090 mPas. The OH-value was determined to be 37 mg.sub.KOH/g.sub.polymer. The particle size distribution was determined to be D[50]=11.1 μm. The product is waxy. Therefore, the stability of the dispersion was tested by heating the product to 90° C. for 3 days. No sedimentation was detected during the heating period, hence, the dispersion was classified as phase-stable.

Example 2: 20 wt % Alumina Silicate in Polyesterol 2

[0076] 100 g hydrous pulverized sodium aluminium silicate (Sipernat® 820 A of Evonik) is added to 400 g of polyesterol with primary hydroxyl end groups based on adipic acid, monoethylene glycol and 1,4-butanediol with a molecular weight of 1400 g/mol, OH-value of 80 mg.sub.KOH/g.sub.polymer, a viscosity of 300 mPas at 75° C. and an acid-value of 0.4 mg.sub.KOH/g.sub.polymer (Lupraphen® of BASF SE). The reaction mixture is heated up to 180° C. under vigorous stirring (400 rpm) and further stirred for 1 h. The product is released at 120° C. The product was characterized by a viscosity of 1340 mPas at 75° C. (shearing rate 1/100 s.sup.−1) and a OH-value of 50 mg.sub.KOH/g.sub.polymer. The particle size distribution of the particles was determined to be D[50]=10.2 μm. The product is waxy. Therefore, the stability of the dispersion was tested by heating the product to 90° C. for 3 days. No sedimentation was detected during the heating period, hence, the dispersion was classified as phase-stable.

Comparative Examples

[0077] Comparative Example 3: 20 wt % Alumina Silicate in Polyesterol 1 GM1485-73

[0078] 100 g alumina silicate (Sipernat® 820 A of Evonik) is added to 400 g of polyesterol with primary hydroxyl end groups based on adipic acid, monoethylene glycol and diethylene glycol with a molecular weight of 2000 g/mol, OH-value of 56 mg.sub.KOH/g.sub.polymer, acid-value of 0.8 mg.sub.KOH/g.sub.polymer and a viscosity of 500 mPas at 75° C. (Lupraphen® of BASF SE). The reaction mixture is heated up to 150° C. under vigorous stirring (400 rpm) and further stirred for 1 h. The product is released at 120° C. The product was characterized by a viscosity of 2990 mPas at 75° C. (shearing rate 1/100 s.sup.−1) and a OH-value of 38 mg.sub.KOH/g.sub.polymer. A dispersion containing 90% of particles smaller than 20.1 μm was yielded (D[50]=7.1 μm). The product is waxy. Therefore, the stability of the dispersion was tested by heating the product to 90° C. for 3 days. Sediments were detected during the heating period, hence, the dispersion was classified as not phase-stable.

Comparative Example 4: 20 wt % Alumina Silicate in Polyesterol 2 GM1485-74

[0079] 100 g alumina silicate (Sipernat® 820 A of Evonik) is added to 400 g of polyesterol with primary hydroxyl end groups based on adipic acid, monoethylene glycol and 1,4-butanediol with a molecular weight of 1400 g/mol, OH-value of 80 mg.sub.KOH/g.sub.polymer, acid-value of 0.4 mg.sub.KOH/g.sub.polymer and a viscosity of 300 mPas at 75° C. (Lupraphen® of BASF SE). The reaction mixture is heated up to 150° C. under vigorous stirring (400 rpm) and further stirred for 1 h. The product is released at 120° C. The product was characterized by a viscosity of 1750 mPas at 75° C. (shearing rate 1/100 s.sup.−1) and a OH-value of 52 mg.sub.KOH/g.sub.polymer. A dispersion containing 90% of particles smaller than 20.6 μm was yielded (D[50]=7.0 μm). The product is waxy. Therefore, the stability of the dispersion was tested by heating the product to 90° C. for 3 days. Sediments were detected during the heating period, hence, the dispersion was classified as not phase-stable.