Hollow particle made of thermoplastic elastomers and porous moulded bodies

Abstract

Hollow beads having a skin of thermoplastic elastomer and a gas-filled cell are useful in the manufacture of shaped porous articles by thermally bonding or adhering the hollow beads together.

Claims

1. A method of manufacturing shaped porous articles, comprising employing hollow beads comprising a skin of thermoplastic elastomer and a gas-filled cell, wherein the skin of the hollow beads has a wall thickness in the range from 0.02 to 2 mm.

2. The method according to claim 1, wherein the hollow beads have a bulk density in the range from 30 to 500 kg/m.sup.3.

3. The method according to claim 1, wherein the hollow beads have a mean bead diameter in the range from 2.5 to 25 mm.

4. The method according to claim 1, wherein the gas-filled cell has a volume in the range from 1 to 10,000 mm.sup.3.

5. The method according to claim 1, wherein the thermoplastic elastomer is selected from the group consisting of thermoplastic polyurethanes (TPUs), thermoplastic polyesters (TPEs), thermoplastic polyether block amides (PEBAs) and thermoplastic styrene-butadiene block copolymers (TPSs).

6. The method according to claim 1, wherein the cell comprises oxygen, nitrogen, argon, carbon dioxide or mixtures thereof.

7. The method according to claim 1, comprising thermally bonding or adhering the hollow beads together.

8. The method according to claim 7, wherein the hollow beads are fused together using hot air, steam, electrical energy or high-energy radiation.

9. A shaped porous article obtained by the method according to claim 7.

10. The shaped porous article according to claim 9, having a density in the range from 50 to 500 kg/m.sup.3.

11. The shaped porous article according to claim 9, wherein the hollow beads are embedded in a matrix formed of a polyurethane adhesive.

12. The shaped porous article according to claim 9, wherein the hollow beads are embedded in a matrix formed of a polyurethane foam.

13. A method, comprising employing the shaped porous articles according to claim 9 as cushioning elements in shoes, sports equipment, automobiles or machines.

Description

EXAMPLES

(1) The examples and comparative tests utilized the following components as defined in Table 1:

(2) TABLE-US-00001 TABLE 1 Code Composition E-TPU1 (Infinergy ® 32-100 U10) expanded, overwhelmingly closed-cell foam beads based on thermoplastic polyurethane, obtained by expanding pelletized, blowing agent-containing TPU1 under pressure and high temperature, bulk densities 110 g/l. E-TPU2 (Infinergy ® 32-150 U10) expanded, overwhelmingly closed-cell foam beads based on thermoplastic polyurethane, obtained by expanding pelletized, blowing agent-containing TPU1 under pressure and high temperature, bulk densities 150 g/l. TPU1 thermoplastic polyether polyurethane having a Shore hardness of 80A based on PTHF1000, 1,4-butanediol, 4,4′-MDI TPU2 thermoplastic polyether polyurethane having a Shore hardness of 85A based on PTHF1000, 1,4-butanediol, 4,4′-MDI K1 Elastopave 6550/101 from BASF Polyurethanes GmbH, compact, 2-component polyurethane adhesive system. HP1 TPU1 tetrahedra having an edge length of 12 mm and a bulk density of 160 g/l HP2 TPU1 cylinders having a length of 15 mm, a diameter of 5.4 mm and a bulk density of 320 g/l HP3 TPU2 tetrahedra having an edge length of 12 mm and a bulk density of 150 g/l
Apparatus:

(3) Brabender laboratory extruder to produce the TPU hoses

(4) Hot-wire laboratory sealing apparatus for sealing off the shaped TPU articles out of the TPU hoses and films/sheets

(5) Methods of Measurement:

(6) To determine bulk density, a 200 ml vessel was filled with beads and weighed. An accuracy of ±5 g/l may be presumed.

(7) The densities of the shaped porous articles were determined to DIN EN ISO 1183-1, A.

(8) The compression load deflection of the shaped porous articles was measured in accordance with DIN EN ISO 3386 at 10%, 25%, 50% and 75% compression.

(9) The compression set of the shaped porous articles was measured to ASTM D395 after conditioning (6 h/50° C./50%).

(10) The rebound resilience of the shaped porous articles was determined to DIN 53512.

(11) Elongation at break and tensile strength were determined to DIN 53504.

(12) Preparation of Hollow TPU Beads HP1 to HP3

(13) Setup of Brabender single-screw laboratory extruder with hose die, takeoff belt and water bath. Extruder type: Brabender Extrusiograph E 19/25 D (19 mm screw diameter)

(14) Three-zone screw, no sieves

(15) Screw speed=25 rpm

(16) Temperature Profile for TPU1 and TPU2:

(17) zone 1: 180° C., zone 2: 190° C., zone 3: 200° C., zone 4: 190° C., hose head: 190° C. (TPU1) or 200° C. (TPU2)

(18) Drying of TPU pellet in circulating air oven at 110° C. for 3 h.

(19) The laboratory extruder was used to convert TPU1 and TPU2 into transparent hoses having an outside diameter of 5.4 mm and a wall thickness of 1.0 mm and also transparent hoses having an outside diameter of 5.0 mm and a wall thickness of 0.2 mm.

(20) The thin-walled hoses obtained were processed using a Qigg laboratory sealer into tetrahedra having an edge length of 12 mm, while the thick-walled hoses were processed with a Kapp handsealer into cylinders having an average length of 15 mm.

(21) Preparation of Shaped Porous Articles

(22) In each case, 100 parts by weight of the hollow beads HP1 to HP3 and/or of the comparative products E-TPU1 and E-TPU2 were mixed as reported in Table 1 with an additional 20 or, respectively, 30 parts by weight of the 2-component PU adhesive K1 and processed into cube-shaped porous articles having an edge length of 44 mm. To this end, the hollow beads HP1 to HP3 and/or the comparative products E-TPU1 and E-TPU 2 were introduced into a PE container, the corresponding amount of components 1 and 2 of adhesive 1 were weighed in, intensively mixed, applied to the hollow beads, intensively mixed therewith and the mixture poured into a foldable mold having an internal edge length of 44 mm.

(23) After the adhesive had cured, the shaped article was demolded and its density determined by the procedure described above.

(24) TABLE-US-00002 TABLE 1 Measured results on shaped porous articles formed from adhered hollow beads of Examples 1 to 3 and Comparative Tests 1 and 2 V1 V2 B1 B2 B3 beads E-TPU1 E-TPU2 HP1 HP2 HP3 add of PU adhesive K1 30 20 20 20 20 [parts by weight] bulk density of hollow 80 150 160 320 150 beads at 23° C. [kg/m.sup.3] 10% compression load 29.8 56.8 69.7 156.7 60.8 deflection [kPa] 25% compression load 57.7 110.1 128.5 381 109.4 deflection [kPa] 50% compression load 135.6 254.7 286.2 1043.4 246.3 deflection [kPa] 75% compression load 485.8 1051.2 1574.9 9299 1381.2 deflection [kPa] density of shaped article 130.9 192.4 265.6 467.2 232.6 [kg/m.sup.3] compression set [%] 50 32.1 19.6 25.8 19.1 rebound resilience [%] 65 67 59 56 64

(25) The shaped articles of Examples B1 to B3, which are in accordance with the present invention, display a significantly higher compression load deflection and lower compression set versus the Comparative Tests V1 and V2.