LEADING EDGE PROTECTION COMPOSITION AND USES THEREO

Abstract

A polyurethane elastomer composition includes a polycarbonate diol and an aliphatic isocyanate, and lacking any solvent. The composition is used for leading edge protection (LEP), preferably of wind turbine rotor blades.

Claims

1. A composition for a polyurethane elastomer comprising: a first component comprising more than 80% by weight of a polycarbonate diol in respect of the total weight of the first component and below 20% by weight of pigments or fillers, in respect of the total weight of the first component; and a second component comprising an aliphatic isocyanate, wherein the composition is solvent free.

2. The composition according to claim 1, wherein the composition comprises no is pigment free.

3. The composition according to claim 1, wherein the polycarbonate diol is selected from 1,5-pentanediol or 1,6-hexanediol or mixtures thereof.

4. The composition according to claim 1, wherein the aliphatic isocyanate comprises at least one HDI-based isocyanate.

5. The composition according to claim 1, wherein the polycarbonate diol has a molecular weight of between 1,000 and 3,000 g/mol; and/or wherein the aliphatic isocyanate has a molecular weight of between 500 and 2,000 g/mol.

6. The composition according to claim 1, wherein the composition comprises between 20 and 60% by weight, of aliphatic isocyanate in respect of the total weight of the composition; and/or wherein the weight ratio of polycarbonate diol:aliphatic isocyanate in the composition is between 3:1 and 1:1.

7. The composition according to claim 1, further comprising one or more catalyst(s); one or more antifoaming agent(s); one or more deaerating agent(s); one or more pigment dispersant(s); one or more adherence improving agent(s); and/or one or more thixotropic agent(s).

8. A leading edge protection (LEP) comprising the composition according to claim 1, in the form of a single layer with a thickness between 100 and 1,000 microns.

9. The LEP according to claim 1, wherein the LEP exhibits a peeling of between 12 and 18 Mein when tested in accordance to UNE-EN-28510-1 at 90°; and/or wherein the LEP exhibits a pull off of more than 5 MPa in accordance to UNE-ISO-4624; and/or wherein the LEP exhibits a UV ageing below 3 Colour DE when tested in accordance to ASTM D4587-05 for 1000 hours, QUV-B 313 nm and radiation of 0.49±0; 02 W/m.sup.2 (310 nm); and/or wherein the LEP exhibits a water uptake of less than 1% by weight in 10 days at a temperature between 18 and 23° C. or less than 2.5% by weight in 1 day at 90° C.; and/or wherein the LEP exhibits a flexibility of between 20 and 100% elongation at 23° C. and between 5 and 20% elongation at −20° C. when tested in accordance to ASTM D522; and/or wherein the LEP exhibits a roughness of Ra between 1 and 5 and a Rz between 10 and 20; when tested in accordance to ISO 4287-99; and/or wherein the LEP exhibits a gloss of more than of 60 GU and less than 5 GU with a geometry of 60°, in accordance to ISO 2813:2014; and/or wherein the LEP exhibits an abrasion of less than 0.05 Wear for 1000 g with an abrasive wheel CS-1000 during 1000 cycles conditions, in accordance to ASTM D4060; and/or wherein the LEP exhibits a hardness between 30 and 80 Shore A in accordance to ISO 868; and/or wherein the composition exhibits a traction of E equal to between 2 and 40 MPa, an elongation at break equal to between 50 and 150% and a Tensile Stress break equal to between 0.001 and 40 MPa, in accordance to ISO 527-2.

10. A method for preparing the composition according to claim 1 or a leading edge protection comprising the composition, the method comprising the following steps: a. mixing the first component and the second component according to claim 1 in a weight ratio between 3:1 and 1:1; b. coating a surface with a single layer of the mix of step (a); and c. curing the coating of step (b) at a temperature between 15° C. and 50° C. between 180 and 30 minutes.

11. A kit comprising at least two containers, wherein the first container comprises a component comprising more than 80% by weight of a polycarbonate diol and below 20% by weight of pigments or fillers, and wherein the second container comprises an aliphatic isocyanate, wherein both containers are solvent free.

12. The kit according to claim 11, wherein the density of the content of the first container is between 1.1 and 1.5 g/cm.sup.3; and/or wherein the density of the content of the second container is between 1.1 and 1.5 g/cm.sup.3.

13. A method of using the composition according to claim 1, or a leading edge protection LEP) comprising the composition, or a kit comprising at least two containers, wherein the first container comprises a component comprising more than 80% by weight of a polycarbonate diol and below 20% by weight of pigments or fillers, and wherein the second container comprises an aliphatic isocyanate, wherein both containers are solvent free, comprising employing the composition, LEP or kit for leading edge protection.

14. The method according to claim 13, comprising employing the composition, LEP or kit for leading edge protection of wind turbine rotor blades.

15. The composition according to claim 1, further comprising one or more catalyst(s), between 0.01 and 0.30% by weight; one or more antifoaming agent(s), between 0.30 and 1.20% by weight; one or more deaerating agent(s), between 0.10 and 0.60% by weight; one or more pigment dispersant(s), below 0.50% by weight; one or more adherence improving agent(s), between 0.10 and 0.60% by weight; and/or one or more thixotropic agent(s), between 0.50 and 4.00% by weight, in respect of the weight of the first component of the composition.

Description

BRIEF DESCRIPTION OF FIGURES

[0043] FIG. 1. Dynamic Mechanical Analysis (DMA) for composition No. 3, at a frequency of 10 Hz.

[0044] FIG. 2. DMA for composition No. 3, at a frequency of 100 Hz.

[0045] FIG. 3. DMA for composition No. 5, at a frequency of 10 Hz.

[0046] FIG. 4. DMA for composition No. 5, at a frequency of 100 Hz.

EXAMPLES

[0047] The following examples illustrate the present invention, especially the advantages of the composition of the invention in respect of LEP.

Example 1: Compositions No. 1 to No. 5

[0048] Compositions of the invention were obtained by the process previously described. Compositions No. 1 and No. 2 do not include fillers or pigments, composition No. 3 was obtained from a component A comprising 96% wt. of polycarbonate diol in respect to the total weight of component A and compositions No. 4 and No. 5 were obtained from a component A comprising 88% wt. and 66% respectively of polycarbonate diol in respect to the total weight of component A.

TABLE-US-00001 TABLE 1 Compositions No. 1 to No. 5. Component No. 1 No. 2 No. 3 No. 4 No. 5 First Polyol ETERNACOL 100 Component PH 50 (500 (g/mol) ETERNACOL 100 36 28 16 PH 100 (1000 g/mol) ETERNACOL 60 60 40 PH 200 (2000 g/mol) ANTIFOAMING TEGO AIREX 1 1 1 AGENT 944 DEAERATING TEGO WET 0.50 0.50 0.50 AGENT 250 PIGMENT DISPERBYK 0.50 0.50 DISPERSANT 108 ADHERENCE DYNASILAN 0.50 0.50 0.50 IMPROVING 1146 AGENT THIXOTROPIC BYK 3 3 3 AGENT 7410 ET CATALYST FOMREZ 0.02 0.02 0.02 SUL 4 PIGMENT PIGMENT 8 40 TEMACOLOR Total First 100 100 100 100 100 Component Second ISOCYANATE DESMODUR 50 Component N3300 DESMODUR 50 100 100 100 100 N3800 MIX RATIO (weight) 1:1 2:1 2:1 2:1 SOLID CONTENT 100% 100% 100% 100% 100% VOC (g/l) 0 0 0 0 0 DENSITY COMPONENT A (g/cm.sup.3) 1.1-1.2 1.1-1.3 1.1-1.4 1.1-1.5 1.1-1.5 DENSITY COMPONENT B (g/cm.sup.3) 1.1-1.2 1.1-1.3 1.1-1.4 1.1-1.5 1.1-1.5 GEL TIME (minutes) 5-9 5-9 5-9 5-9 5-9

Example 2: Curing

[0049] Compositions No. 1 to 5 were applied in a single layer layer with a thickness between 100 and 1,000 microns and said coatings were cured at a temperature between 15° C. and 50° C. during between 30 and 180 minutes and at 5% RH.

Example 3: Characterization of Composition No. 4

[0050] Composition No. 4 was characterized by several tests.

TABLE-US-00002 TABLE 2 Results of the characterization of composition No. 4. Test Standard Result Comments Peeling test UNE-EN-28510-1 >16 N/cm 90° Pull off test UNE-ISO-4624 >5 MPa UV ageing test ASTM D4587-05 <3 1000 hours, QUV-B 313 nm and radiation of 0.49 ± 0.02 W/m.sup.2 (310 nm) Water uptake test <1% (18-23° C.) 10 days at a <2.5% (90° C.) temperature between 18 and 23° C. or less than 2.5% by weight in 1 day at 90° C. Flexibility test ASTM D522 23° C.: e >22%- 23° C. and −20° C. 20° C.: e >8% Roughness test ISO 4287-99 Ra: 1.24 (Sanded) Rz: 13.66 (Sanded) Gloss test ISO 2813: 2014 62 Non Sanded Geometry 60° 1.5 Sanded Abrasion test ASTM D4060 −0.02 1000 g with abrasive wheels CS-1000 during 1000 cycles Hardness test ISO 868 70 Shore A

Example 4: Rain Erosion Test

[0051] A rain erosion test was carried out according to DNVGL-RP-0171, a standard commonly used in the wind industry. The test in an acceleration from where the erosion of a protection is measured, by means of an accelerated erosion three samples of each composition to test were introduced in a chamber and were subjected to impacts of raindrops at the rate of 701/hour at a speed of 147 m/s.

TABLE-US-00003 TABLE 3 Results of the rain erosion test under DNVGL-RP-0171. COMPOSITION Minutes No. 1 300 No. 2 600 No. 3 960 No. 4 960 No. 5 120

Example 5: Measure of the Resistance

[0052] The resistance of compositions No. 3 and No. 5 was measured by a Dynamic Mechanical Analysis (DMA) according to standard ASTM D5418:2015 including a temperature sweep and oscillatory test mode where the sample undergoes a bending oscillating strain during a temperature ramp is applied. The conditions were as follows: [0053] Temperature sweep from −80° C. to 100° C. at 3° C./min. [0054] Frequency: 10 Hz and 100 Hz. [0055] Strain amplitude: 20 microns, selected within the linear viscosity region (LVR) determined in previous tests with similar materials. [0056] Test specimen: 60 mm×10 mm×3 mm. [0057] At least 2 measurement per sample.

[0058] The results were shown in FIGS. 1 to 4 and in the following tables.

TABLE-US-00004 TABLE 4 Data for the DMA for composition No. 3, at a frequency of 10 Hz. T 50° C. T 10° C. Storage Loss Storage Loss Modulus Modulus Modulus Modulus Tg onset Tg Loss Tg peak Test (MPa) (MPa) (MPa) (MPa) ° C. ° C. ° C. 1 1479 61.00 5.26 1.71 −22.12 −19.86 −10.71 2 1398 57.41 5.77 1.57 −22.45 −20.26 −10.85 Average 1439 59 6 2 −22 −20 −11

TABLE-US-00005 TABLE 5 Data for the DMA for composition No. 3, at a frequency of 100 Hz. T 50° C. T 10° C. Storage Loss Storage Loss Modulus Modulus Modulus Modulus Tg onset Tg Loss Tg peak Test (MPa) (MPa) (MPa) (MPa) ° C. ° C. ° C. 1 1620 74.79 11.08 8.05 −19.74 −16.46 −5.16 2 1568 75.59 — 8.71 −20.02 −16.36 −5.03 Average 1594 75 — 8 −22-20 −16 −5

TABLE-US-00006 TABLE 6 Data for the DMA for composition No. 5, at a frequency of 10 Hz. T 50° C. T 10° C. Storage Loss Storage Loss Modulus Modulus Modulus Modulus Tg onset Tg Loss Tg peak Test (MPa) (MPa) (MPa) (MPa) ° C. ° C. ° C. 1 1948 72.50 8.51 2.71 −22.12 −19.86 −10.71 2 1652 68.53 7.01 2.27 −22.45 −20.26 −10.85 Average 1800 70 8 2 −22 −20 −11

TABLE-US-00007 TABLE 7 Data for the DMA for composition No. 5, at a frequency of 100 Hz. T 50° C. T 10° C. Storage Loss Storage Loss Modulus Modulus Modulus Modulus Tg onset Tg Loss Tg peak Test (MPa) (MPa) (MPa) (MPa) ° C. ° C. ° C. 1 1970 95.27 11.16 7.65 −19.86 −16.68 −5.23 2 1888 94.04 12.63 8.68 −20.21 −16.99 −4.80 Average 1929 95 12 8 −20 −17 −5

[0059] In this test of DMA the behaviour of the material obtained from compositions 3 and 5 of the invention at frequencies of 10 and 100 Hertz was evaluated. This test simulates the behaviour of the protection of the leading edge against rain impact. It can be seen the lower values of the constants that govern the viscoelastic behaviour of the material in the storage modulus (Storage Modulus) and modulus of losses (Loss modulus) as shown in tables 4 to 7. These lower values make the material behave in a more elastic way and show a better elastic behaviour.

Example 6: LEP Application with Adhesion Promoter in Plant Conditions

[0060] The systematic procedure for the right application of the LEP adhesion promoter in plant conditions where the blade is placed in horizontal position is the following:

[0061] Surface preparation: sand the previous layer applied to remove the gloss and ensure a good adhesion. Clean the surface with a solvent compatible with the surface, for example isopropyl acetate. Delimit the zone to be protected with tape: Primer zone, transition zone and LEP zone.

[0062] Adhesion primer application: clean the surface with a solvent compatible with the surface, for example isopropyl acetate. Apply the primer on the delimited zone with a mixing gun and spread it with a roller. Check the wet film thickness with a standard gauge each meter. The recommended thickness is between 75 to 125 microns. Remove the tapes delimiting the primer zone.

[0063] LEP application: wait until the application window starts depending on the environmental conditions. Apply LEP using an appropriate mixing gun and spread it with a filling knife. Check the wet film thickness with a standard gauge each meter. The recommended thickness is between 550 to 650 microns. Remove the tapes delimiting the transition zone. Use a small filling knife to make a transition between the LEP and the tape delimiting the LEP zone. Remove the tape delimiting the LEP zone.

Example 7: Application with Adhesion Promoter in Conditions with Access by Rope or Platform In Situ

[0064] The systematic procedure for the right application of the LEP adhesion promoter in conditions with access by rope or platform is the following:

[0065] Surface preparation: sand all the eroded zone (or previous layer if it has been applied) to remove the gloss and ensure a good adhesion. In the longitudinal direction of the leading edge, sand 50 mm of the old LEP leaving a smooth transition between the old LEP and the repaired zone (transition zone). Soak a paper with a solvent compatible with the surface, for example isopropyl acetate and clean the surface. Delimit the zone to be protected with tape: Primer zone, first LEP layer zone and second LEP layer zone.

[0066] Adhesion primer application: clean the surface with a solvent compatible with the surface, for example isopropyl acetate. Apply the primer on the delimited zone with a mixing gun and spread it with a roller. Check the wet film thickness with a standard gauge each meter. The recommended thickness is between 75 to 125 microns. Remove the tapes delimiting the primer zone.

[0067] LEP application. First layer: wait until the application window starts depending on the environmental conditions. Apply LEP using an appropriate mixing gun and spread it with a roller. Leave the transition zone without LEP. Check the wet film thickness with a standard gauge each meter. The recommended thickness is between 300 to 350 microns. Level the surface with a brush with longitudinal movements. Remove the tapes delimiting the first LEP layer zone.

[0068] LEP application. Second layer: wait until the application window starts depending on the environmental conditions. Apply LEP using an appropriate mixing gun and spread it with a roller. Do not leave the transition zone without LEP. Check the wet film thickness with a standard gauge each meter. The recommended thickness is between 300 to 350 microns. Level the surface with a brush with longitudinal movements. Remove the tapes delimiting the second LEP layer zone. Level the step between the old and new LEP with a brush.