THERMOSET POLYMER POWDER

Abstract

The invention relates to a thermoset polymer powder having a particle size D90 of 60 μm or less, determined by laser diffraction, wherein the polymer is obtainable by polymerization of compounds having one or more ethylenically unsaturated polymerizable groups, and wherein the compounds having one or more ethylenically unsaturated polymerizable groups include at least one compound having at least two ethylenically unsaturated polymerizable groups.

Claims

1. A thermoset polymer powder having a particle size D90 of 60 μm or less determined by laser diffraction, wherein the polymer is obtained by a process comprising polymerization of compounds having one or more ethylenically unsaturated polymerizable groups, and wherein the compounds having one or more ethylenically unsaturated polymerizable groups include at least one compound having at least two ethylenically unsaturated polymerizable groups.

2. The thermoset polymer powder according to claim 1, wherein the at least one compound having at least two ethylenically unsaturated polymerizable groups comprises a compound having three ethylenically unsaturated polymerizable groups.

3. The thermoset polymer powder according to claim 1, wherein the at least one compound having at least two ethylenically unsaturated polymerizable groups has an ethylenically unsaturated polymerizable group equivalent weight in the range of 85 g/equivalent to 180 g/equivalent.

4. The thermoset polymer powder according to claim 1, wherein at least 60 weight-% of the polymer consists of polymerized compounds having at least two ethylenically unsaturated polymerizable groups and having an ethylenically unsaturated polymerizable group equivalent weight in the range of 85 g/equivalent to 180 g/equivalent.

5. The thermoset polymer powder according to claim 1, wherein particles of the polymer powder have break edges.

6. The thermoset polymer powder according to claim 1, wherein a surface of particles of the polymer powder is at least partly covered with a surfactant.

7. A thermoset polymer powder having a particle size D90 of 60 μm or less determined by laser diffraction, the thermoset polymer powder being obtained by a process comprising: introducing a feed material into an inlet of a reactor, the reactor comprising the inlet, an outlet, and a reaction zone, the feed material comprising compounds having one or more ethylenically unsaturated polymerizable groups, and wherein the compounds having one or more ethylenically unsaturated polymerizable groups include at least one compound having at least two ethylenically unsaturated polymerizable groups, exerting shear force on the feed material in the reaction zone of the reactor and causing the ethylenically unsaturated polymerizable groups to polymerize to form a thermoset polymer, and crushing the thermoset polymer to form thermoset polymer particles and moving the thermoset polymer particles through the outlet of the reactor.

8. A process of preparing a thermoset polymer powder the process comprising: introducing a feed material into an inlet of a reactor, the reactor comprising the inlet, an outlet, and a reaction zone, the feed material comprising compounds having one or more ethylenically unsaturated polymerizable groups, and wherein the compounds having one or more ethylenically unsaturated polymerizable groups include at least one compound having at least two ethylenically unsaturated polymerizable groups, exerting shear force on the feed material in the reaction zone of the reactor and causing the ethylenically unsaturated polymerizable groups to polymerize to form a thermoset polymer, and crushing the thermoset polymer to form thermoset polymer particles and moving the thermoset polymer particles through the outlet of the reactor.

9. The process according to claim 8, wherein the reactor comprises an extruder.

10. The process according to claim 8, wherein the feed material comprises a combined content of water and volatile organic solvent between 0.0 and 5.0% by weight, calculated on the weight of the feed material introduced in the reactor.

11. The process according to claim 8, further comprising milling the thermoset polymer particles to a desired particle size.

12. The process according to claim 11, wherein the milling comprises jet-milling.

13. The process according to claim 8, further comprising fractioning the thermoset polymer particles to a desired particle size range.

14. The process according to claim 8, wherein energy is introduced during one or more of exerting of shear force on the feed material and crushing the thermoset polymer.

15. The process according to claim 14, wherein the energy is introduced in the form of one or more of thermal energy, mechanical energy, and actinic radiation.

16. The process according to claim 8, further comprising introducing a radical generating initiator into the reaction zone.

17. The process according to claim 8, further comprising cooling the thermoset polymer particles after the thermoset polymer particles leave the outlet of the reactor.

18. (canceled)

19. (canceled)

20. The polymer powder according to claim 1, wherein the polymer powder has a particle size D90 of 50 μm or less.

21. A coating composition comprising the thermoset polymer powder according to claim 1 and water.

22. A coating composition comprising the thermoset polymer powder according to claim 1 and a solvent.

23. A polymer composition comprising an organic polymer and the thermoset polymer powder according to claim 1.

24. A material comprising cellulose and the thermoset polymer powder according to claim 1.

25. A process of modifying a composition, the process comprising adding to the composition the thermoset polymer powder according to claim 1.

26. The process of claim 25, the thermoset polymer powder acting in the composition as one or more of a filler, a modifier of tactile surface properties, a matting agent, an opacifying agent, and an improver of mechanical properties.

27. The process according to claim 25, wherein the composition comprises a coating composition, an organic polymer, or a cellulose based material.

Description

EXAMPLES

Preparation Examples 1 to 5

[0063] A 250 g mixture, containing one or more monomers with one or more initiators according to Table 1 was provided at ambient temperature. In the Tables, the abbreviation pbw stands for “parts by weight”.

TABLE-US-00001 TABLE 1 compositional information of used monomer(s) and initiator combinations for examples 1 to 5 Example Monomer(s) pbw Initiator(s) pbw Catalyst pbw 1.1 Tripropylene Glycol 98.90 Tert-butyl peroxy- 1.10 Diacrylate 2-ethylhexanoate 2.1 2,2- 99.80 2,2′-Azodi (2- 0.20 Bis[(acryloyloxy)methyl]butyl methylbutyronitrile) acrylate 3.1 2,2- 75.00/24.80 2,2′-Azodi (2- 0.20 Bis[(acryloyloxy)methyl]butyl methylbutyronitrile) acrylate/Tripropylene Glycol Diacrylate 4.1 1,4 Butanediol- 98.90 Tert-butyl peroxy- 1.10 dimethacrylate 2-ethylhexanoate 5.1 Unsaturated Polyester based 57.84/31.15/9.89 Tert-Butyl peroxy- 0.92/0.18 Copper 0.02 on orthophthalic acid and 2-ethylhexanoate/ Siccative standard glycols/Styrene/ Di-tert-butyl 8% Cu MMA peroxide

[0064] Each reactive mixture according to

[0065] Table 1 was pumped into a laboratory twin-screw extruder (model Prism TSE 16 PC, barrel bore diameter (D) 16 mm, screw diameter 15.5 mm, ratio of barrel length L/D 14/1). The speed of the extruder as well as other parameters and settings are shown in Table 2.

TABLE-US-00002 TABLE 2 Settings of the used reaction extruder during the formation of materials according to examples 1 to 5 Rotational speed Temperature Through- Example [rpm] [° C.] put [g/min] 1.2 100 150 4.3 2.2 200 120 10.0 3.2 200 130-160 10.0 4.2 100 150 4.0 5.2 50 130 12.0

[0066] After 1 to 10 minutes of extrusion the output collection at the extruder outlet started. The collection of the extrusion outlet ended as soon as the dosing of liquid mixture to the extruder was finished. By this process it was ensured that the extrusion process ran in stationary condition and the resulting output had a constant quality.

[0067] All five output materials were white to off-white free flowing powders. Particle size measurements based on the principle of laser diffraction using a Sympatec Helos apparatus according to ISO 13220-1 are summarized in Table 3.

TABLE-US-00003 TABLE 3 particle size distribution of examples 1 to 5 as received after extrusion process Example D10 [μm] D50 [μm] D90 [μm] Color 1.3 20.85 85.40 214.69 White to off white 2.3 20.86 157.13 318.17 White to off white 3.3 White to off white 4.3 18.79 164.54 318.43 White to off white 5.3 23.90 120.62 White to off white

[0068] To make the five materials more suitable for the application area in coatings each of them were milled in a jet-mill, Type AFG of Hosokawa Alpine AG.

[0069] After jet-mill processing the particle size distribution was substantially smaller, as measured by laser diffraction using the Sympatec Helos. An overview of the particle size distribution after jet-milling is provided in Table 4.

TABLE-US-00004 TABLE 4 particle size distribution of examples 1 to 5 after jet milling Example D10 [μm] D50 [μm] D90 [μm] Color 1.4 2.56 10.74 20.50 White to off white 2.4 1.53 9.03 16.97 White to off white 3.4 1.35 7.91 16.18 White to off white 4.4 1.66 10.17 18.00 White to off white 5.4 6.84 15.55 White to off white

[0070] In the next step the materials from examples 1 to 5 were transferred to an application test.

[0071] 400 g of the coating test system were prepared by mixing the components according to Table 5 with a Dissolver mixing aggregate for 10 min at 4 m/s speed.

TABLE-US-00005 TABLE 5 Coating composition Component pbw Setaqua 6756.sup.1 91.60 RHEOBYK-H 0.10 7625 VF.sup.2 Butyl Diglycol 1.60 Butyl Glycol 1.60 Water 3.40 RHEOBYK-T 1.00 1000 VF.sup.2 BYK-093.sup.2 0.50 BYK-349.sup.2 0.20 .sup.1available from Allnex Germany GmbH .sup.2available from BYK Chemie GmbH

[0072] In 50 g of the coating system according to Table 5 we added 2.5 g of powder from the examples 1 to 5 according to Table 4 and mixed with a Dissolver mixing aggregate at 4 m/s for 5 minutes.

[0073] After 1 day at room temperature the liquid coating systems according to examples 1 to 5 plus a comparative coating composition without any powder according to this invention were applied in a wet layer thickness of 100 μm onto black plexi-glass panels for gloss measurement, and on glass panels for transmission measurement.

[0074] After 1 day of drying at ambient conditions the gloss was measured with BYK-Gardner Gloss measurement device micro-TRI-gloss μ.

[0075] The coatings on glass panels were measured with BYK-Gardner haze-gard i to get information about light transmission T. The light transmission T is indicated in % of the quantity of light transmitted through the coating.

[0076] All measurements were done in comparison to a control sample. The results are summarized in Table 6.

TABLE-US-00006 TABLE 6 gloss and transmission measurement results from coating systems comprising powders according to examples 1 to 5 in comparison to control sample Example Gloss (20°) Gloss (65°) Gloss (80°) T (%) Control 81 86 97 94 1.5 3 17 21 93 2.5 2 14 17 92 3.5 2 13 17 91 4.5 2 12 14 92 5.5 2 14 26

[0077] The results in Table 6 indicate that the polymer powder of the invention significantly reduces the gloss of the tested coating composition. The gloss reduction is observed at various measurement angles. The polymer powder only causes a very small decrease of the light transmission. Therefore, the polymer powder is highly suitable as matting agent.