Component composed at least to some extent of a layer structure and process for production thereof

Abstract

The invention relates to a component having at least to some extent a layer structure, wherein the layer structure includes an elastomer layer with a density greater than 800 g/L, and a thermoset layer including at least 50% by weight of a first polyurethane. The invention further relates to a process for the production of a component of this type, the process including (i) provision of a female mold into which the individual layers of the layer structure are introduced, or of a male mold to which the individual layers of the layer structure are applied; (ii) production of the elastomer layer via spraying; (iii) production of the thermoset layer via spraying; and (iv) demolding of the resultant component. Step (ii) can be carried out before step (iii) or step (iii) can be carried out before step (ii).

Claims

1. A process for the production of a component comprising a layer structure, wherein the layer structure comprises the following layers: (a) an elastomer layer with density greater than 800 g/L, and (b) a thermoset layer comprising at least 50% by weight of a first polyurethane, wherein the elastomer layer has a Shore hardness according to DIN ISO 7619-1:2010 of less than 95 Shore A, wherein the process comprises the following steps: (i) provision of one of a female mold into which the individual layers of the layer structure are introduced, or of a male mold to which the individual layers of the layer structure are applied, (ii) production of the elastomer layer via spraying, (iii) production of the thermoset layer via spraying, and (iv) demolding of the resultant component, wherein step (ii) can be carried out before step (iii) or step (iii) can be carried out before step (ii).

2. The process according to claim 1, wherein the thermoset layer is one of (a) foamed wherein the density thereof is less than 600 g/L, or (b) compact wherein the density thereof is greater than 800 g/L.

3. The process according to claim 2, wherein the thermoset layer comprises a first sublayer and at least one second sublayer, wherein the first sublayer comprises the first polyurethane, wherein the first polyurethane has been foamed, and wherein the at least one second sublayer comprises a third polyurethane, wherein the density of the third polyurethane is higher than the density of the first polyurethane.

4. The process according to claim 1, wherein the layer structure further comprises an insulating layer, wherein the insulating layer is composed of a rigid foam which comprises at least 80% by weight of at least one of a polyisocyanurate and a second polyurethane.

5. The process according to claim 1, wherein the elastomer layer has an elongation at break according to DIN EN ISO 527:2012 of at least 150%.

6. The process according to claim 4, wherein the layer structure further comprises at least one layer of coating material.

7. The process according to claim 1, wherein the elastomer layer is composed of a material selected from the group consisting of homopolyurethane, homopolyurea, and copolymers comprising polyurethane and polyurea.

8. The process according to claim 6, wherein the layer structure is in the following sequence: layer of coating material, elastomer layer, thermoset layer, insulating layer.

9. The process according to claim 3, wherein the layer structure has at least one of (a) a second sublayer on a side of the first sublayer that faces toward the elastomer layer, and (b) a second sublayer on a side of the first sublayer that faces away from the elastomer layer.

10. The process according to claim 9, wherein the thickness of the first sublayer is in the range from 1 to 30 mm, and the thickness of each second sublayer is in the range from 1 to 10 mm.

11. The process according to claim 1, wherein the elastomer layer comprises up to 100% by weight of polyurea.

12. The process according to claim 1, wherein the thickness of the elastomer layer is in the range from 0.2 to 4 mm and the thickness of the thermoset layer is in the range from 2 to 40 mm.

13. The process according to claim 1, wherein at least one of the layers comprises reinforcing fibers or fillers.

14. The process according to claim 1, where the component is selected from the group consisting of a separator for use in mining, a cooling device for an electrical device, a housing for an electrical device, part of a vehicle, part of sports equipment, and part of a sanitary device.

15. The process according to claim 1, wherein in a first step a layer of coating material is applied to the female mold or male mold.

16. The process according to claim 1, wherein a layer of coating material is applied to the component before the demolding process or after the demolding process.

17. The process according to claim 1, wherein the component is heated before or after the demolding process.

18. The process according to claim 1, wherein an insulating layer is also applied via spraying or casting.

Description

EXAMPLES

(1) For the examples one layer structure respectively was produced by sequential spraying of a layer of coating material, an elastomer layer and a thermoset layer. In some examples no layer of coating material or elastomer layer was used, for comparison purposes. As the final step, the layer structure was placed in a mold and coated with a rigid foam in the closed mold. Square specimens with a side length of 4 cm were cut from the component produced this way.

(2) In a ball drop test the impact resistance of the specimen was determined. The diameter of the spherically shaped tip of the drop weight was 20 mm. The specimens were exposed to 30 joule in the ball drop test. The impact on the specimen took place on the side away from the rigid foam.

(3) For the layer structure in the individual examples the following material was used:

(4) Layer of Coating Material:

(5) A commercially available high-strength, solvent-free, two-component gel coating on a polyurethane/polyurea-copolymer basis with a hardness of more than 70 Shore D.

(6) Elastomer A:

(7) A spray polyurethane/polyurea-copolymer with 10% by weight of surface-coated calcium carbonate with a mean particle size d50 of 3 μm and d98 of 15 μm and with a hardness of 95 Shore A and 46 Shore D, determined according to DIN ISO 7619-1:2010, respectively, a density of 1100 kg/m.sup.3 determined according to DIN EN ISO 1183-1:2013, a tensile strength of 14 MPa, an elongation at break according to DIN EN ISO 527:2012 of 100% and a tear resistance according to DIN ISO 34-1:2004 of 53 N/mm.

(8) Elastomer B:

(9) A spray polyurethane/polyurea-copolymer with 10% by weight of surface-coated calcium carbonate with a mean particle size d50 of 3 μm and d98 of 15 μm and with a hardness of 77 Shore A, determined according to DIN ISO 7619-1:2010, a density of 1060 kg/m.sup.3 determined according to DIN EN ISO 1183-1:2013, a tensile strength von 8 MPa, an elongation at break according to DIN EN ISO 527:2012 of 460% and a tear resistance according to DIN ISO 34-1:2004 of 20 N/mm.

(10) Thermoset A:

(11) A spray polyurethane/polyurea-copolymer with 20% by weight of chalk and with a hardness of 63 Shore D determined according to DIN ISO 7619-1:2010, a bulk density of 600 kg/m.sup.3 determined according to DIN EN ISO 845:2009, a 3 point flexural modulus of elasticity of 870 MPa, a flexural strength of 21 MPa, a deflection of 7 mm, determined according to DIN EN ISO 178:2010 and DIN EN ISO 178 A1:2013, respectively, and a glass transition temperature of more than 70° C.

(12) Thermoset B:

(13) A spray polyurethane with 15% by weight of chopped glass fiber with a fiber length of 8 mm and with a bulk density of 850 kg/m.sup.3 determined according to DIN EN ISO 845:2009, a tensile strength of 32 MPa, an elongation at break of 2% according to DIN EN ISO 527:2012 and a glass transition temperature of more than 70° C.

(14) The rigid foam used was Elastocool® 2030/13/OT by BASF Polyurethanes GmbH.

(15) Table 1 shows the results of the ball drop test for various layer structures.

(16) TABLE-US-00001 TABLE 1 Results of the ball drop test Layer structure (mm) Layer thickness Result ball No. Layer in mm drop test Example 1 Elastomer A 2.35 Not passed Thermoset A 4.60 Rigid foam 40.00 Example 2 Layer of coating material 0.15 Not passed Elastomer A 1.60 Thermoset A 7.20 Rigid foam 40.00 Example 3 Thermoset A 6.30 Not passed Rigid foam 40.00 Example 4 Layer of coating material 0.20 Not passed Elastomer A 2.4 Thermoset B 4.60 Rigid foam 40.00 Example 5 Thermoset B 6.30 Not passed Rigid foam 40.00 Example 6 Layer of coating material 0.20 Not passed Thermoset B 6.30 Rigid foam 40.00 Example 7 Elastomer B 2.35 Passed Thermoset A 3.90 Rigid foam 43.40 Example 8 Layer of coating material 0.20 Passed Elastomer B 2.30 Thermoset A 4.00 Rigid foam 40.00 Example 9 Layer of coating material 0.20 Passed Elastomer B 2.3 Thermoset B 4.00 Rigid foam 40.00 Example 10 Elastomer B 2.3 Passed Thermoset B 4.00 Rigid foam 40.00

(17) The ball drop test was deemed to have been passed if after an impact of 30 joule no or only slight marks of the drop weight could be seen, if there were no tears in the elastomer and in the thermoset tears with a length of less than 2 cm occurred, the tears in the thermoset not affecting more than one layer.

(18) The ball drop test was deemed to not have been passed if one of the following criteria was fulfilled: the layer structure comprising thermoset layer, elastomer layer if applicable, and layer of coating material displayed tears in all layers, in addition to the tears the rigid foam was deformed irreversibly, tears occurred in the layer of coating material and the mark of the drop weight can be discerned visually, a tear with a length of more than 2 cm occurred in the thermoset, the elastomer displays distinct tears with a length of more than 1 cm, the layer structure comprising thermoset layer, elastomer layer, if applicable, and layer of coating material, if applicable, does not show tears, but the rigid foam was so deformed irreversibly that this leads to an visible mark in the component or to an irreversible separation of the layers from the rigid foam below.

(19) The examples clearly show that leaving off the layer of coating material does not seem to affect the results of the impact stress, but that an elastomer layer is indispensable. Furthermore, the physical properties of the elastomer layers have an effect of the results of the impact stress.