POLYURETHANES WITH GOOD PERMEABILITY TO ELECTROMAGNETIC RADIATION

Abstract

The invention provides articles made of thermoplastic polyurethane based on polycarbonate diol which are a constituent of a device that receives or transmits electromagnetic radiation, are a cover for a device, or are used in proximity to such a device. The invention further provides for the use of thermoplastic polyurethane based on polycarbonate diol for these articles.

Claims

1-14. (canceled)

15. An article, made of a thermoplastic polyurethane, and which is a constituent of a device or a cover for the device or which is used in proximity to the device, wherein the device receives or transmits electromagnetic radiation and the thermoplastic polyurethane is produced from at least one diisocyanate and at least one isocyanate-reactive substance having a number-average molecular weight of more than 0.50010.sup.3 g/mol, wherein the at least one isocyanate-reactive substance comprises at least one polycarbonate having at least two hydroxyl groups, and wherein the frequency of the electromagnetic radiation is between 10.sup.4 Hz and 10.sup.13 Hz.

16. The article of claim 15, wherein the at least one polycarbonate is an aliphatic polycarbonate.

17. The article of claim 15, wherein the at least one polycarbonate is based on diols selected from the group consisting of butanediol, pentanediol and hexanediol.

18. The article of claim 15, wherein the at least one diisocyanate is selected from the group consisting of 4,4-, 2,4- and 2,2-dicyclohexylmethane diisocyanate (H12 MDI), 1,6-hexamethylene diisocyanate (HDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and/or -2,6-cyclohexane diisocyanate, 2,2-, 2,4- and/or 4,4-diphenylmethane diisocyanate (MDI), and 2,4- and/or 2,6-tolylene diisocyanate (TDI).

19. The article of claim 15, wherein the at least one diisocyanate is selected from the group consisting of 1,6-hexamethylene diisocyanate (HDI) and 2,2-, 2,4- and/or 4,4-diphenylmethane diisocyanate (MDI).

20. The article of claim 15, wherein the production of the thermoplastic polyurethane further employs an aliphatic, araliphatic, aromatic or cycloaliphatic compound having isocyanate-reactive groups and a molecular weight between 0.05 g/mol and 0.499 g/mol as a chain extender.

21. The article of claim 20, wherein the production of the thermoplastic polyurethane employs an organic metal compound as a catalyst.

22. The article of claim 15, wherein the article is a frame or a protective cover for the device.

23. The article of claim 15, wherein the thermoplastic polyurethane comprises an inorganic fibrous filler.

24. The article of claim 23, wherein the inorganic fibrous filler is a coated glass fiber.

25. A process of producing the article of claim 15, the process comprising obtaining the thermoplastic polyurethane.

26. A process of producing an article which is a constituent of a device or a cover for the device or which is used in proximity to the device, the process comprising obtaining a thermoplastic polyurethane, wherein the device receives or transmits electromagnetic radiation and the thermoplastic polyurethane is produced from at least one diisocyanate and at least one isocyanate-reactive substance having a number-average molecular weight of more than 0.50010.sup.3 g/mol, wherein the at least one isocyanate-reactive substance comprises at least one polycarbonate having at least two hydroxyl groups, and wherein the frequency of the electromagnetic radiation is between 10.sup.4 Hz and 10.sup.13 Hz.

Description

EXAMPLES

1. Example 1Production of the Polymers in Manual Casting Process

[0154] The polyols were initially charged in a container at 80 C. and mixed by vigorous stirring with the components according to the following TPU formulations in a batch size of 2 kg. The reaction mixture was heated to above 110 C. and was then poured out onto a heated, Teflon-coated table. The obtained casting was heat treated at 80 C. for 15 hours, subsequently comminuted and injection molded to afford injection molded sheets of 2 mm in thickness. The injection molding temperatures were varied in the range of 180 C.-220 C. depending on the respective melt viscosity.

2. Example 2Materials Used for the Comparative Examples

[0155] TPU 1: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on polytetrahydrofuran (PTHF) having a molecular weight (Mn) of 1000 dalton, butane-1,4-diol, MDI. [0156] TPU 2: TPU of Shore hardness 90A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on polytetrahydrofuran (PTHF) having a molecular weight (Mn) of 1000 dalton, butane-1,4-diol, MDI. [0157] TPU 3: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on polytetrahydrofuran (PTHF) having a molecular weight (Mn) of 1000 dalton, 1,2-ethylene glycol, HDI. [0158] TPU 4: TPU of Shore hardness 90A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on an adipic ester having a molecular weight (Mn) of 800 dalton, butane-1,4-diol, MDI. [0159] TPU 5: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on an adipic ester having a molecular weight (Mn) of 1000 dalton, butane-1,4-diol, MDI. [0160] TPU 6: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on an adipic ester having a molecular weight (Mn) of 2400 dalton, butane-1,4-diol, MDI. [0161] TPU 7: TPU of Shore hardness 95A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on an adipic ester having a molecular weight (Mn) of 2400 dalton, butane-1,4-diol, MDI. [0162] TPU 8: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on an adipic ester having a molecular weight (Mn) of 2000 dalton, butane-1,4-diol, HDI. [0163] TPU 9: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on Ultradur B4500, an adipic ester having a molecular weight (Mn) of 2000 dalton, butane-1,4-diol, HDI. Produced by the process described in EP0141918861. [0164] TPU 10: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on Capromer PD 1-20 (polycaprolactone) having a molecular weight (Mn) of 2000 dalton, butane-1,4-diol, MDI. [0165] TPU 11: TPU of Shore hardness 85A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on Capromer PD 1-20 (polycaprolactone) having a molecular weight (Mn) of 2000 dalton, butane-1,4-diol, H12MDI.

3. Example 3Inventive Examples

[0166] TPU 12: TPU of Shore hardness 95A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on Ultradur B4500, a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, HDI. Produced by the process described in EP0141918861. [0167] TPU 13: TPU of Shore hardness 80A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, HDI. [0168] TPU 14: TPU of Shore hardness 80A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Bayer (Desmophen 2200), butane-1,4-diol, MDI. [0169] TPU 15: TPU of Shore hardness 80A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, MDI. [0170] TPU 16: TPU of Shore hardness 90A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, MDI. [0171] TPU 17: TPU of Shore hardness 55D from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, MDI. [0172] TPU 18: TPU of Shore hardness 62D from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, MDI. [0173] TPU 19: TPU of Shore hardness 90A from BASF Polyurethanes GmbH, Elastogranstrasse 60, 49448 Lemfrde, based on a polycarbonate diol from Ube (Eternacoll PH-200D), butane-1,4-diol, H12MDI.

4. Example 4

[0174] The pellets of the abovementioned materials were melted and films of about 2 mm in thickness were produced to determine the dielectric loss factor. A low dielectric loss factor indicates a low attenuation of the incident signal strength.

[0175] After conditioning of 14 days under standard climatic conditions (23 C., 50% atmospheric humidity) 2 samples were in each case measured according to IEC 60250 under standard climatic conditions (23 C., 50% atmospheric humidity). The sample thickness was 2.0 mm.

[0176] The average values of the measurements are shown in the tables which follow.

TABLE-US-00001 TABLE 1 comparative examples Dielectric Dielectric Sample Frequency/ constant/ loss factor description [MHz] (r) (tan ) TPU 1 500 3.7 0.098 TPU 2 500 3.7 0.092 TPU 3 500 4.2 0.148 TPU 4 500 3.7 0.072 TPU 5 500 3.9 0.089 TPU 6 500 4.2 0.115 TPU 7 500 3.7 0.076 TPU 8 500 4.3 0.146 TPU 9 500 3.9 0.102 TPU 10 500 3.7 0.086 TPU 11 500 3.4 0.069

TABLE-US-00002 TABLE 2 inventive examples Dielectric Dielectric Sample Frequency constant loss factor description [MHz] (.sub.r) (tan ) TPU 12 400 2.9 0.017 TPU 13 400 2.8 0.036 TPU 14 400 2.9 0.023 TPU 15 400 2.9 0.022 TPU 16 400 2.9 0.018 TPU 16 500 2.9 0.015 TPU 17 400 2.9 0.016 TPU 18 400 2.9 0.015 TPU 19 400 2.8 0.019 [0177] It is apparent that the dielectric loss factor is markedly lower for the polyurethanes based on polycarbonate than for the types lacking polycarbonate diol.

CITED LITERATURE

[0178] Kunststoffhandbuch, volume 7, Polyurethane, Carl Hanser Verlag, 3rd edition 1993, chapter 5 [0179] Kunststoffhandbuch, volume 7, Polyurethane, Carl Hanser Verlag, 3rd edition 1993, chapter 6 [0180] Polyurethane Handbook, Hanser, Munich, 1993, chapter 3.2 and chapter 3.4 and chapter 6.1 [0181] Kunststoffhandbuch, volume 7, Polyurethane, Carl Hanser Verlag, 3rd edition 1993 chapter 3.1 [0182] Glass Fibers, Frederick T. Wallenberger, James C. Watson, and Hong Li, PPG Industries, Inc.; ASM Handbook, Vol. 21: Composites [0183] Plastics Additives Handbook, 5th edition, H. Zweifel, ed., Hanser, Munich, 2001, pp. 98-136 [0184] EP 0989146 A1 [0185] EP 1460094 A1 [0186] PCT/EP2005/010124 [0187] EP 1529792 A1