THERMOPLASTIC POLYURETHANE FOAM AND IMPACT RESISTANT COMPOSITE LAMINATE COMPRISING THE SAME

Abstract

Provided are a thermoplastic polyurethane foam and an impact resistant composite laminate. The thermoplastic polyurethane comprises a structural unit represented by Formula (I):

##STR00001## wherein each R independently is an alkylene group having 2 to 8 carbon atoms or —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2— or —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2—; n is a number from 2 to 13; and the structural unit has a Mn ranging from 700 g/mole to 2500 g/mole. The impact resistant composite laminate comprises a base layer and a first impact resistant layer formed by the thermoplastic polyurethane foam, and the first impact resistant layer overlaps the base layer.

Claims

1. A thermoplastic polyurethane foam, prepared by a foaming process from a raw material comprising a thermoplastic polyurethane; wherein the thermoplastic polyurethane comprises a structural unit represented by Formula (I): ##STR00007## in Formula (I), each R independently is an alkylene group having 2 to 8 carbon atoms, —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2— or —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2—; n is a number from 2 to 13; and the structural unit represented by Formula (I) has a number-average molecular weight ranging from 700 grams per mole (g/mole) to 2500 g/mole.

2. The thermoplastic polyurethane foam according to claim 1, wherein the thermoplastic polyurethane comprises a structural unit represented by Formula (II): ##STR00008## in Formula (II), each R.sub.1 independently is an alkylene group having 2 to 8 carbon atoms or —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2— or —CH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2—; R.sub.2 is ##STR00009## and n is a number from 2 to 13.

3. The thermoplastic polyurethane foam according to claim 1, wherein the thermoplastic polyurethane comprises a thermoplastic polyurethane of CAS No. 2484808-99-1, a thermoplastic polyurethane of CAS No. 2626937-63-9, a thermoplastic polyurethane produced by a diol with a structural unit represented by Formula (I), polyethylene glycol, butanediol and methylene diphenyl diisocyanate, a thermoplastic polyurethane produced by a diol with a structural unit represented by Formula (I), polytetramethylene ether glycol, butanediol and methylene diphenyl diisocyanate or any combinations thereof.

4. The thermoplastic polyurethane foam according to claim 1, wherein the foaming process is a physical foaming process.

5. The thermoplastic polyurethane foam according to claim 4, wherein the physical foaming process is a supercritical foaming molding.

6. The thermoplastic polyurethane foam according to claim 5, wherein the supercritical foaming molding comprises: a foaming process including a step of supercritical fluid impregnation of pellets followed by a foaming step and then a thermoforming step, a foaming process including a step of supercritical fluid impregnation of a molded article followed by a foaming step, a foaming process including a foam injection press step with a supercritical fluid, a foaming process including a thermoforming step of foam beads obtained by pelletizing extrusion with a supercritical fluid or a foaming process including a supercritical fluid extrusion molding step.

7. The thermoplastic polyurethane foam according to claim 1, wherein the thermoplastic polyurethane foam has a thickness ranging from 1.5 millimeters to 30 millimeters.

8. The thermoplastic polyurethane foam according to claim 7, wherein the thermoplastic polyurethane foam has the thickness ranging from 4 millimeters to 15 millimeters.

9. The thermoplastic polyurethane foam according to claim 7, wherein the thermoplastic polyurethane foam achieves Level 1 of European Standard EN1621-1: 2012.

10. The thermoplastic polyurethane foam according to claim 1, wherein the thermoplastic polyurethane foam has a density ranging from 0.15 g/cm.sup.3 to 1.10 g/cm.sup.3.

11. An impact resistant composite laminate comprising a base layer and a first impact resistant layer overlapping the base layer; wherein the first impact resistant layer is formed by the thermoplastic polyurethane foam according to claim 1.

12. The impact resistant composite laminate according to claim 11, wherein the base layer comprises a rigid plastic layer, a foam elastomer, a woven fabric, a knit fabric, a nonwoven fabric, a leather, a fiberglass layer or any combinations thereof.

13. The impact resistant composite laminate according to claim 11, wherein the impact resistant composite laminate further comprises a surface layer, and the first impact resistant layer is disposed between the surface layer and the base layer; wherein the surface layer comprises a rigid plastic layer, a foam elastomer, a woven fabric, a knit fabric, a nonwoven fabric, a leather, a fiberglass layer or any combinations thereof.

14. The impact resistant composite laminate according to claim 11, wherein the impact resistant composite laminate further comprises a second impact resistant layer, and the base layer is disposed between the first impact resistant layer and the second impact resistant layer; wherein the second impact resistant layer is formed by the thermoplastic polyurethane foam according to claim 1.

15. The impact resistant composite laminate according to claim 13, wherein the impact resistant composite laminate further comprises a second impact resistant layer, and the base layer is disposed between the first impact resistant layer and the second impact resistant layer; wherein the second impact resistant layer is formed by the thermoplastic polyurethane foam according to claim 1.

16. The impact resistant composite laminate according to claim 11, wherein the impact resistant composite laminate is used for applications of handles, personal protective equipment, machinery safety equipment or medical protective equipment.

17. The impact resistant composite laminate according to claim 11, wherein the impact resistant composite laminate achieves Level 1 of European Standard EN1621-1: 2012.

18. The impact resistant composite laminate according to claim 17, wherein the first impact resistant layer has a thickness ranging from 4 millimeters to 15 millimeters.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0090] FIG. 1 is a schematic side sectional view of the TPU foam in accordance with the present disclosure.

[0091] FIG. 2 is a scanning electron microscope (SEM) image of the TPU foam of the Preparation Example 1A.

[0092] FIG. 3 is a SEM image of the TPU foam of the Preparation Example 4.

[0093] FIG. 4 is a schematic side sectional view of one embodiment of an impact resistant composite laminate in accordance with the present disclosure.

[0094] FIG. 5 is a schematic side sectional view of another embodiment of an impact resistant composite laminate in accordance with the present disclosure.

[0095] FIG. 6 is a schematic side sectional view of still another embodiment of an impact resistant composite laminate in accordance with the present disclosure.

[0096] FIG. 7 is a schematic diagram of the Application Example 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0097] Hereinafter, one skilled in the arts can easily realize the advantages and effects of the present disclosure from the following examples and comparative examples. Therefore, it should be understood that the descriptions proposed herein are just preferable examples for the purpose of illustrations only, not intended to limit the scope of the disclosure. Various modifications and variations could be made in order to practice or apply the present disclosure without departing from the spirit and scope of the disclosure.

[0098] Thermoplastic Polyurethane

[0099] The TPUs comprising the structural unit represented by Formula (I) used to form the TPU foam of each Example could be prepared by adapting the synthetic method recorded in TWI697512B or other conventional synthetic methods. The information of chemical formula, CAS No. and the Tg of each of the TPUs comprising the structural unit represented by Formula (I) were listed in Table 1.

TABLE-US-00001 TABLE 1 TPU No. TPU-1 TPU-2 TPU-3 TPU-4 CAS No. 2484808-99-1 Weight 68.1 wt % 64.9 wt % 64.9 wt % 69.9 wt % percentage of the structural unit represented by Formula (I) Value of n in 7.74 3.57 5.40 5.40 Formula (I) Tg (° C.) 28.04 27.87 31.19 28 TPU No. TPU-5 TPU-6 TPU-7 TPU-11 CAS No. 2484808-99-1 — Weight 70 wt % 70 wt % 65.2 wt % 56.7 wt % percentage of the structural unit represented by Formula (I) Value of n in 5.92 7.09 7.74 8.06 Formula (I) Tg (° C.) 24.88 25.54 31.02 −7.04 TPU No. TPU-8 TPU-9 TPU-10 TPU-12 CAS No. 2626937-63-9 — Weight 65.2 wt % 70 wt % 67.2 wt % 58.6 wt % percentage of the structural unit represented by Formula (I) Value of n in 7.68 4.74 7.67 6.44 Formula (I) Tg (° C.) 18.28 18.03 19.25 13.27

[0100] TPU-11 was obtained by a condensation polymerization which used diethylene glycol-phthalic anhydride-based polyester polyol (Mn of 2011 and acid value of 1.0), PEG (PEG1000 purchased from EnHou Polymer Chemical Ind. Co., Ltd.; Mn of 955), 1,4-butanediol and MDI as raw materials. Its chemical formula was (C.sub.15H.sub.10N.sub.2O.sub.2.Math.C.sub.8H.sub.4O.sub.3.Math.C.sub.4H.sub.10O.sub.3.Math.C.sub.4H.sub.10O.sub.2.Math.C.sub.2H.sub.4O.sub.2).sub.X.

[0101] TPU-12 was obtained by a condensation polymerization which used 1,6-hexanediol-phthalic anhydride-based polyester polyol (Mn of 1811 and acid value of 0.77), PEG (PEG1000 purchased from EnHou Polymer Chemical Ind. Co., Ltd.; Mn of 955), 1,4-butanediol and MDI as raw materials. Its chemical formula was (C.sub.15H.sub.10N.sub.2O.sub.2.Math.C.sub.8H.sub.4O.sub.3.Math.C.sub.6H.sub.14O.sub.2.Math.C.sub.4H.sub.10O.sub.2.Math.C.sub.2H.sub.4O.sub.2).sub.X.

[0102] The TPU comprising the structural unit represented by Formula (I) used to form the TPU foam may choose other TPU as long as it comprises the structural unit represented by Formula (I).

[0103] Preparation of Thermoplastic Polyurethane Foam

[0104] In order to demonstrate the TPU foam obtained from the TPU comprising a structural unit represented by Formula (I) can provide a good impact resistance, TPU foams obtained from each Preparation Example of the present disclosure were respectively made from the aforementioned TPU-1 to TPU-12 only, without adding any plasticizer and impact modifier.

[0105] Preparation Method I: A Foaming Process Including a Step of SCF Impregnation of Pellets Followed by a Foaming Step and then a Thermoforming Step

[0106] TPU-1 pellets were put into an autoclave (0.3 liter stainless steel high-pressure reaction tank), and then the SCF (CO.sub.2) was introduced into the autoclave in which the pressure was set at 100 kgf/cm.sup.2 and the temperature was at 150° C. After TPU-1 pellets were impregnated for 30 min, the pressure was released and the temperature was decreased, and TPU-1 foam beads were obtained.

[0107] Preparation Example 1A (PE 1A): 15 g of TPU-1 foam beads was taken to undergo a thermoforming step by electric heating for 30 seconds (sec), and then cooled to the temperature lower than 70° C.; finally the TPU foam was obtained in a form of hot-plassed plaque. The relevant parameters of thermoforming as follows: upper mold of 140° C.; lower mold of 150° C.; hot-pressed under the pressure of 15 kgf/cm.sup.2.

[0108] PE 1A had a thickness of 8.75 mm and a density of 0.16 g/cm.sup.3. In addition, PE 1A was measured according to ASTM D2632 Standard Method at 23±2° C. to obtain its rebound resilience of 12%.

[0109] Preparation Example 1B (PE 1B): 18 g of TPU-1 foam beads which had been preheated in an oven was taken to undergo a thermoforming step by electric heating for 30 sec, and then cooled to the temperature lower than 80° C.; finally the TPU foam was obtained in a form of a hot-pressed plaque. The relevant parameters of thermoforming are as follows: upper mold of 140° C.; lower mold of 150° C.; hot-pressed under the pressure of 15 kgf/cm.sup.2.

[0110] PE 1B had a thickness of 8.6 mm and a density of 0.18 g/cm.sup.3.

[0111] Preparation Example 2A (PE 2A): 50 g of TPU-1 foam beads was taken into a mold to undergo a thermoforming step by heating with stream under the pressure of 5 kgf/cm.sup.2, and then the TPU foam was obtained in a form of a molded plaque with a thickness of 26.75 mm.

[0112] According to ASTM D395 Standard Method, PE 2A was compressed to 25% of its original height to measure its compression set. The compression set measured under 50° C. for a maintained period of 6 hours was 41.16%; the compression set measured under 25° C. for a maintained period of 24 hours was 13.4%.

[0113] In addition, PE 2A was measured according to ASTM D2632 Standard Method at 23±2° C. to obtain its rebound resilience of 11%.

[0114] Preparation Example 2B (PE 2B): 45 g of TPU-1 foam beads was taken into a mold to undergo a thermoforming step by heating with stream under the pressure of 5 kgf/cm.sup.2, and then the TPU foam was obtained in a form of a molded plaque with a thickness of 20 mm and a density of 0.36 g/cm.sup.3.

[0115] In addition, PE 2B was measured according to ASTM D2632 Standard Method at 23±2° C. to obtain its rebound resilience of 7%.

[0116] Preparation Method II: A Foaming Process Including a Step of SCF Impregnation of a Molded Article Followed by a Foaming Step

[0117] The TPU was subjected to a thermoforming process to obtain a sample of the molded article in a thickness of 2 mm. Or the TPU was subjected to an injection molding process to obtain a sample of the molded article in a thickness of 5 mm. The aforementioned sample was put into an autoclave (100 liters stainless steel high-pressure reaction tank), and then the SCF (CO.sub.2) was introduced into the autoclave in which the pressure was set at 150 kgf/cm.sup.2 in usual and the temperature was set at the range from 75° C. to 120° C. After an impregnation for 60 min to 240 min, the pressure was released and the temperature was cooled to room temperature, and samples of TPU foam were obtained. All of the samples of the TPU were placed at room temperature for at least one week prior to testing.

[0118] Preparation Example 3 (PE 3) to Preparation Example 10 (PE 10), Preparation Example 14 (PE 14) to Preparation Example 17 (PE 17) and Preparation Example 26 (PE 26) to Preparation Example 29 (PE 29) were obtained by the Preparation Method II and the relevant parameters were listed in Table 2; wherein the thickness and the density of each sample were measured just before the impact resistance performance test.

TABLE-US-00002 TABLE 2 Thickness Thickness Preparation of molded Impregnation of foam Example TPU article Temp. duration sample Density No. No. (mm) (° C.) (min) (mm) (g/cm.sup.3) PE 3 TPU-1 5 115 240 6.5 0.42 PE 4 TPU-1 5 115 240 8.6 0.25 PE 5 TPU-1 5 115 240 7.51 0.30 PE 6 TPU-2 2 85 120 2.65 0.97 PE 7 TPU-3 2 85 120 2.52 0.67 PE 8 TPU-4 2 85 120 2.05 1.06 PE 9 TPU-9 2 120 120 4.15 0.22 PE 10 TPU-5 2 120 120 3.97 0.19 PE 14 TPU-1 5 115 240 5.28 0.42 PE 15 TPU-3 2 75 120 2.06 1.06 PE 16 TPU-5 2 120 120 3.66 0.30 PE 17 TPU-6 2 120 120 3.18 0.35 PE 26 TPU-8 2 120 60 2.40 0.66 PE 27 TPU-10 2 100 90 3.84 0.69 PE 28 TPU-11 2 100 90 2.30 0.67 PE 29 TPU-12 2 120 60 2.25 0.91

[0119] Preparation Method III: A Foaming Process Including a Foam IP Step with an SCF

[0120] Specifically, the relevant parameters for the foam IP step with an SCF could be referred to as follows: when the supercritical injection molding machine of FCS Group was used, the temperature was set in the range from 165° C. to 180° C.; for example, the feeding temperature was 180° C.; the screw temperature was set at multiple stages such as 180° C., 180° C., 175° C. and 170° C.; the nozzle temperature was 165° C. In addition, the stock was set at 13 bar, with a rotation speed of 32 revolutions per minute (rpm) and at the position of 75 mm. The injection amount of liquid nitrogen SCF was 1.125 g, and the molding cycle time was about 4 min. Finally, the resulting TPU foam board with the hard skin layers had a thickness of 22 mm. The resulting TPU foam board could be sliced to form a TPU foam sheet without the hard skin layers (in the middle of the TPU foam board) and/or at least two TPU foam sheets which had a skin layer on one side of the TPU foam board as Preparation Examples.

[0121] All of Preparation Example 11 to Preparation Example 13 and Preparation Example 18 to Preparation Example 25 were obtained by carrying out Preparation Method III with TPU-7 as raw material and using the supercritical injection molding machine of FCS Group; further, they were respectively a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. All of Preparation Example 11 to Preparation Example 13 and Preparation Example 18 to Preparation Example 25 had a density of 0.28 g/cm.sup.3, and their thickness was measured just before the impact resistance performance test.

[0122] Preparation Example 30 was obtained by carrying out Preparation Method III with TPU-7 as raw material and using the supercritical injection molding machine of FCS Group; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 30 had a thickness of 6.5 mm and a density of 0.28 g/cm.sup.3.

[0123] Preparation Example 31 was obtained by carrying out Preparation Method III with TPU-7 as raw material and using the supercritical injection molding machine of FCS Group; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 31 had a thickness of 6.5 mm and a density of 0.39 g/cm.sup.3.

[0124] Or, when the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd. was used, the temperature was set in the range from 190° C. to 193° C. and the pressure was set at 8 bar; moreover, the SCF was liquid nitrogen. The obtained TPU foam board (with the hard skin) may have a thickness ranging from 20 mm to 22 mm. When the set density of TPU foam board was about 0.2 g/cm.sup.3, the molding cycle time was about 600 sec; and when the set density of TPU foam board was about 0.4 g/cm.sup.3, the molding cycle time was about 1440 sec.

[0125] Preparation Example 32 was obtained by carrying out Preparation Method III with TPU-7 as raw material and using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd.; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 32 had a thickness of 6.6 mm and a density of 0.28 g/cm.sup.3. In addition, Preparation Example 32 had a Shore hardness of 55A at 21° C. according to ASTM D2242 Standard Method. Preparation Example 32 had a rebound resilience of 20% at 23±2° C. according to ASTM D2632 Standard Method.

[0126] Preparation Example 33 was obtained by carrying out Preparation Method III with TPU-7 as raw material and using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd.; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 33 had a thickness of 6.7 mm and a density of 0.39 g/cm.sup.3. In addition, Preparation Example 33 had a Shore hardness of 68A at 21° C. according to ASTM D2242 Standard Method. Preparation Example 33 had a rebound resilience of 20% at 23±2° C. according to ASTM D2632 Standard Method.

[0127] Preparation Example 34 was obtained by carrying out Preparation Method III with TPU-10 as raw material and using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd.; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 34 had a thickness of 8.2 mm and a density of 0.39 g/cm.sup.3. In addition, Preparation Example 34 had a Shore hardness of 44A at 21° C. according to ASTM D2242 Standard Method. Preparation Example 34 had a rebound resilience of 7% at 23±2° C. according to ASTM D2632 Standard Method.

[0128] Preparation Example 35 was obtained by carrying out Preparation Method III with TPU-10 as raw material and using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd.; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 35 had a thickness of 5.6 mm and a density of 0.39 g/cm.sup.3. In addition, Preparation Example 35 had a Shore hardness of 44A at 21° C. according to ASTM D2242 Standard Method. Preparation Example 35 had a rebound resilience of 7% at 23±2° C. according to ASTM D2632 Standard Method.

[0129] Preparation Example 36 was obtained by carrying out Preparation Method III with TPU-10 as raw material and using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd.; further, it was also a TPU foam sheet without the hard skin by slicing the obtained TPU foam board. Preparation Example 36 had a thickness of 6.97 mm and a density of 0.28 g/cm.sup.3. In addition, Preparation Example 36 had a Shore hardness of 25A at 21° C. according to ASTM D2242 Standard Method. Preparation Example 36 had a rebound resilience of 7% at 23±2° C. according to ASTM D2632 Standard Method.

[0130] In addition, TPU-10 was subjected to Preparation Method III by using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd., so as to obtain a TPU foam board with a density of 0.28 g/cm.sup.3. Followed by a slicing process, Preparation Example 37, which was a TPU foam sheet without a hard skin layer, Preparation Example 38, which was a TPU foam sheet with the lower skin layer, and Preparation Example 39, which was a TPU foam sheet with the upper skin layer were obtained. Preparation Examples 37 to 39 respectively had a thickness of 6.8 mm, 6.9 mm and 7.4 mm in order.

[0131] Similarly, TPU-10 was subjected to Preparation Method III by using the supercritical injection molding machine (NexCell KS310-S2) of King Steet Machinery Co., Ltd., so as to obtain a TPU foam board with a density of 0.28 g/cm.sup.3. Followed by a slicing process, Preparation Example 40, which was a TPU foam sheet without a hard skin layer, Preparation Example 41, which was a TPU foam sheet with the lower skin layer, and Preparation Example 42, which was a TPU foam sheet with the upper skin layer were obtained. Preparation Examples 40 to 42 respectively had a thickness of 6.3 mm, 7.0 mm and 7.84 mm in order.

[0132] As shown in FIG. 1, the impact resistant layer 11A was directly formed by the aforementioned TPU foam, so as to facilitate to carry out an analysis for impact resistance performance.

[0133] The materials used as the impact resistant layers of each Comparative Example were described as follows.

[0134] 1. F-C1: a commercial impact resistant material I with a thickness of 7.1 mm, which was taken from D3O (Product No.: DS5115 HYPER KNEE/SHIN); wherein D3O was a composite material which contained PBDMS dispersed throughout the solid foamed PU elastomer matrix.

[0135] 2. F-C2: a commercial impact resistant material II with a thickness of 10.5 mm, which was taken from D3O (Product No.: ICON GUARD D3O BACK MD 2706-0163).

[0136] 3. F-C3: an EVA foam with a thickness of 8 mm, which was taken from a commercial volleyball knee pad.

[0137] 4. F-C4: a hot-pressed plaque whose material comprises the structural unit of PTMEG; with a thickness of 10.6 mm and a density of 0.34 g/cm.sup.3; wherein F-C4 was taken from the midsole of commercial Boost shoes.

[0138] 5. F-C5: a shapeable fiberglass layer taken from a commercial baseball elbow pad without fabrics; wherein the fiberglass layer was composed of a moisture-curable resin and glass fibers; with a thickness of 5.2 mm and a density of 0.9 g/cm.sup.3.

[0139] 6. F-C6: a commercial volleyball knee pad which was composed of an EVA foam covered by fabrics and had a total thickness of 13.2 mm.

[0140] 7. F-C7: the EVA foam of F-C6 with a thickness of 8.41 mm and a density of 0.1 g/cm.sup.3.

[0141] 8. F-C8: a commercial volleyball knee pad which was composed by a mixture of PU foam and EVA foam; wherein the mixture was covered by fabrics (the ratio of PU foam and EVA foam was indicated as 3:7); F-C8 had a total thickness of 10.35 mm.

[0142] 9. F-C9: another commercial volleyball knee pad which was composed of an EVA foam covered by fabrics and had a total thickness of 23.4 mm.

[0143] 10. F-C10: an ETPV foam elastomer with a thickness of 7.1 mm, a Shore hardness of 35 C and a density of 0.21 g/cm.sup.3; wherein the ETPV foam elastomer was formed by hot press foaming an ETPV resin of E342-35 purchased from Sunko Ink Co., Ltd.; E342-35 was a polymer elastomer material in which vulcanized EPDM microparticles were dispersed in a continuous combination phase of ethylene copolymer and polyolefin block copolymer.

[0144] 11. F-C11: a commercial EVA foam with a thickness of 3.75 mm.

[0145] 12. F-C12: a commercial styrofoam board with a thickness of 3.29 mm and a density of 0.0754 g/cm.sup.3.

[0146] 13. F-C13: a thermoformed sheet formed by steam expansion of foamed microballs taken from BASF SE and a thermoforming step; wherein the foamed microballs were identified as TPU foam beads with PTMEG structural units; F-C13 with a thickness of 11.3 mm and a density of 0.30 g/cm.sup.3.

[0147] Analysis 1: Observation of the Morphology of the TPU Foam

[0148] The morphology of Preparation Examples was respectively observed by SEM. The TPU foams of Preparation Example 1A and Preparation Example 4 were taken for example.

[0149] With reference to FIG. 2, FIG. 2 was a photograph from SEM (×100) of the TPU foam of Preparation Example 1A. As shown in FIG. 2, the cells of the TPU foam of Preparation Example 1A were mainly closed voids in a shape of polyhedron; wherein the cells had a size ranging from 1 μm to 100 μm and the major range of size thereof ranged from 20 μm to 80 μm.

[0150] With reference to FIG. 3, which was a photograph from SEM (×100) of the TPU foam of Preparation Example 4. As shown in FIG. 3, the cells of the TPU foam of Preparation Example 4 were mainly closed voids in a shape of polyhedron wherein the cells had a size ranging from 1 μm to 150 μm and the major range of size thereof ranged from 10 μm to 50 μm.

[0151] Analysis 2: Impact Resistance Performance Test for TPU Foam

[0152] In Tables 3 to 5, Table 6-1 and Table 6-2, the impact resistant layers of Examples formed by the aforementioned Preparation Examples and Comparative Examples were respectively analyzed by a shock tester (DP-1200 of KING DESIGN INDUSTRIAL) under a specific test condition, and the resulting “penetrating impact (F.sub.t)”, “reduced impact (F.sub.s)”, a reduced impact ratio and the impact resistance per unit thickness of test samples for the impact resistant layers were listed in Tables 3 to 5, Table 6-1 and Table 6-2.

[0153] The test conditions used in this test were respectively Test Conditions A to C listed as follows:

[0154] 1. Test Condition A: a standard weight of 5.0 kg hammer was dropped freely at a height of 1.0 m to hit against test samples vertically, so the potential energy provided by the hammer was about 50 J;

[0155] 2. Test Condition B: a standard weight of 5.0 kg hammer was dropped freely at a height of 0.5 m to hit against test samples vertically, so the potential energy provided by the hammer was about 25 J;

[0156] 3. Test Condition C: a standard weight of 5.0 kg hammer was dropped freely at a height of 0.25 m to hit against test samples vertically, so the potential energy provided by the hammer was about 12.5 J.

[0157] The “Blank” test refers to an impact force measured by a free drop of the hammer under a specific test condition to directly hit the platform of the shock tester without any test samples thereon; the impact force measured by Blank test could be also called the “original impact (F.sub.0)”.

[0158] The “penetrating impact (F.sub.t)” refers to an impact force penetrating through the test sample, measured by a free drop of the hammer under a specific test condition to hit a test sample on the platform of the shock tester.

[0159] The “reduced impact (F.sub.s)” refers to the impact force that the test sample dissipates when withstanding an external force under the specific test condition. F.sub.s is the difference obtained from F.sub.0 minus F.sub.t. (F.sub.s=F.sub.0−F.sub.t)

[0160] The “reduced impact ratio” is a ratio of the “reduced impact (F.sub.s)” to the “original impact (F.sub.0)”; that is, “reduced impact ratio”=F.sub.s/F.sub.0.

[0161] The “impact resistance per unit thickness” is a ratio of the “reduced impact ratio” to the thickness of the impact resistant layer; that is, “impact resistance per unit thickness”=(F.sub.s/F.sub.0)/thickness.

[0162] Impact resistant layers of Example 1 (F-E1) to Example 3 (F-E3) and Example 14 (F-E14) to Example 18 (F-E18) and impact resistant layers of Comparative Example 1 (F-C1) to Comparative Example 3 (F-C3) were all tested for impact resistance under Test Condition A at room temperature (25° C.±2° C.), and the results were listed in Table 3. F-C3 was broken in appearance after the impact resistance performance under Test Condition A.

TABLE-US-00003 TABLE 3 Impact resistance Thick- Time per unit ness domain F.sub.t F.sub.s thickness PE No. (mm) (mS) (kN) (kN) F.sub.s/F.sub.0 (%/mm) Blank — — 0.7 96.35 — — — F-E1 PE 1A 8.75 2.93 27.81 68.54 71.13% 8.13 F-E2 PE 1B 8.60 5.21 20.69 75.66 78.53% 9.13 F-E3 PE 3 6.50 2.02 35.05 61.3 63.62% 9.79 F-E14 PE 27 3.84 1.69 50.67 45.68 47.41% 12.35  F-E15 PE 32 6.60 2.10 34.00 62.35 64.71% 9.80 F-E16 PE 37 6.80 2.33 32.96 63.39 65.79% 9.68 F-E17 PE 38 6.90 2.33 34.49 61.86 64.20% 9.30 F-E18 PE 39 7.40 3.06 26.76 69.59 72.23% 9.76 F-C1 — 7.1 2.54 42.11 54.24 56.29% 7.93 F-C2 — 10.5 4.25 20.06 76.29 79.18% 7.54 F-C3 — 8 0.76 93.31 3.04  3.16% 0.39

[0163] Impact resistant layers of Example 4 (F-E4) to Example 8 (F-E8) and Example 19 (F-E19) to Example 25 (F-E25) and impact resistant layers of Comparative Example 4 (F-C4) to Comparative Example 12 (F-C12) were all tested for impact resistance under Test Condition B at room temperature (25° C.±2° C.), and the results were listed in Table 4.

TABLE-US-00004 TABLE 4 Impact resistance Thick- Time per unit ness domain F.sub.t F.sub.s thickness PE No. (mm) (mS) (kN) (kN) F.sub.s/F.sub.0 (%/mm) Blank — — 0.67 60.99 — — — F-E4 PE 4 8.60 5.98 9.27 51.72 84.80% 9.86 F-E5 PE 7 2.52 1.48 37.15 23.84 39.09% 15.51 F-E6 PE 27 3.84 1.85 26.69 34.30 56.24% 14.65 F-E7 PE 10 3.97 2.96 27.93 33.06 54.21% 13.65 F-E8 PE 11 6.60 3.07 16.94 44.05 72.22% 10.94 F-E19 PE 28 2.30 1.26 38.62 22.37 36.68% 15.95 F-E20 PE 29 2.25 1.75 31.64 29.35 48.12% 21.39 F-E21 PE 30 6.50 2.92 16.93 44.06 72.24% 11.11 F-E22 PE 35 5.60 1.98 23.28 37.71 61.83% 11.04 F-E23 PE 40 6.30 2.34 20.32 40.67 66.68% 10.58 F-E24 PE 41 7.00 3.15 14.56 46.43 76.13% 10.88 F-E25 PE 42 7.84 4.01 13.94 47.05 77.14% 9.84 F-C4 — 10.60 3.41 30.90 30.09 49.34% 4.65 F-C5 — 5.2 2.14 30.31 30.68 50.30% 9.67 F-C6 — 13.2 3.28 33.48 27.51 45.11% 3.42 F-C7 — 8.41 0.92 57.85 3.14 5.15% 0.61 F-C8 — 10.35 4.20 23.18 37.81 61.99% 5.99 F-C9 — 23.4 2.01 33.46 27.53 45.14% 1.93 F-C10 — 7.1 0.98 49.04 11.95 19.59% 2.76 F-C11 — 3.75 0.78 54.40 6.59 10.81% 2.88 F-C12 — 3.29 0.77 58.97 2.02 3.31% 1.01

[0164] Impact resistant layers of Example 9 (F-E9) to Example 13 (F-E13) and Example 26 (F-E26) to Example 32 (F-E32) and an impact resistant layer of Comparative Example 13 (F-C4) were all tested for impact resistance under Test Condition C at room temperature (25° C.±2° C.), and the results were listed in Table 5.

TABLE-US-00005 TABLE 5 Impact resistance Thick- Time per unit ness domain F.sub.t F.sub.s thickness PE No. (mm) (mS) (kN) (kN) F.sub.s/F.sub.0 (%/mm) Blank — — 0.68 37.24 — — — F-E9 PE 14 5.28 2.78 11.68 25.56 68.64% 13.00 F-E10 PE 15 2.06 1.54 26.32 10.92 29.32% 14.23 F-E11 PE 16 3.66 4.76 11.32 25.92 69.60% 19.02 F-E12 PE 17 3.18 4.37 12.22 25.02 67.19% 21.13 F-E13 PE 9 4.15 5.84 9.27 27.97 75.11% 18.10 F-E26 PE 27 3.84 1.93 17.16 20.08 53.92% 14.04 F-E27 PE 28 2.30 2.36 13.6 23.64 63.48% 27.60 F-E28 PE 29 2.25 1.98 15.41 21.83 58.62% 26.05 F-E29 PE 30 6.50 3.04 10.44 26.80 71.97% 11.07 F-E30 PE 31 6.50 2.38 16.02 21.22 56.98% 8.77 F-E31 PE 35 5.60 2.16 15.57 21.67 58.19% 10.39 F-E32 PE 36 6.97 2.91 10.34 26.90 72.23% 10.36 F-C13 — 11.3  6.28 11.73 25.51 68.50% 6.06

[0165] The impact resistant layers of Example 1-2 (F-E1-2), Example 1-3 (F-E1-3) and F-E1 were all prepared by the TPU foam of PE 1A. The difference among them was the test temperature under Test Condition A, and the results were listed in Table 6-1.

TABLE-US-00006 TABLE 6-1 Impact resistance Thick- Time per unit Test ness domain F.sub.t F.sub.s thickness Temp. (mm) (mS) (kN) (kN) F.sub.s/F.sub.0 (%/mm) Blank 25° C. — 0.7 96.35 — — — F-E1 25° C. 8.75 2.93 27.81 68.54 71.13% 8.13 F-E1-2 50° C. 8.75 3.48 25.65 70.70 73.38% 8.39 F-E1-3 60° C. 8.75 2.57 35.5 60.85 63.16% 7.22

[0166] Similarly, the impact resistant layers of Example 7-2 (F-E7-2) and F-E7 were all prepared by the TPU foam of PE 10. The difference between them was the test temperature under Test Condition B (i.e. F-E7-2 was test at 5° C.), and the results were listed in Table 6-2.

[0167] Further, the impact resistant layers of Example 4-2 (F-E4-2) and F-E4 were all prepared by adapting the TPU foam obtained from TPU-1 through Preparation Method II. However, F-E4 and F-E4-2 had a slight difference in thickness and they were tested at different temperatures for the impact resistance performance test under Test Condition B, and the results were listed in Table 6-2.

[0168] Similarly, the impact resistant layers of Example 8-2 (F-E8-2), Example 8-3 (F-E8-3) and F-E8 were all prepared by adapting the TPU foam obtained from TPU-7 through Preparation Method III. However, F-E8, F-E8-2 and F-E8-3 had a slight difference in thickness and they were tested at different temperatures for the impact resistance performance test under Test Condition B, and the results were listed in Table 6-2.

TABLE-US-00007 TABLE 6-2 Impact resistance Thick- per unit ness Test F.sub.t F.sub.s thickness PE No. (mm) Temp. (kN) (kN) F.sub.s/F.sub.0 (%/mm) Blank — — 25° C. 60.99 — — — F-E4 PE 4 8.60 25° C. 9.27 51.72 84.80% 9.86 F-E4-2 PE 5 7.51 50° C. 11.17 49.82 81.69% 10.88 F-E7 PE 10 3.97 25° C. 27.93 33.06 54.21% 13.65 F-E7-2 PE 10 3.97 50° C. 18.84 42.15 69.11% 17.41 F-E8 PE 11 6.6 25° C. 16.94 44.05 72.22% 10.94 F-E8-2 PE 12 6.67 70° C. 21.61 39.38 64.57% 9.68 F-E8-3 PE 13 6.9 90° C. 43.05 17.94 29.41% 4.26

[0169] Analysis 3: Impact Resistance and Resilience Test of Foam Beads

[0170] Foam beads in PE 1A and foamed microballs of BASF in F-C13 were respectively put in the same cotton mesh bags to analyze the impact resistance performance. At the same time, the aforementioned cotton mesh bags containing foam beads/microballs were observed whether they would rebound after being hit by an external force.

[0171] Wherein, a total thickness of the bag body of each cotton mesh bag was 0.5 mm (that is, the thickness of the single bag wall was 0.25 mm); and the total thickness of each cotton mesh bag filled with foam beams/microballs was 10.0 mm, so it meant the thickness formed by the foam beads/microballs contained in the aforementioned cotton mesh bag was 9.5 mm.

[0172] In Table 7-1, the foam beads in PE 1A and the foamed microballs in F-C13 were respectively tested for impact resistance under Test Condition A at room temperature (25° C.±2° C.), and the results were listed in Table 7-1.

[0173] In Table 7-2, the foam beads in PE 1A and the foamed microballs in F-C13 were respectively tested for impact resistance under Test Condition B at room temperature (25° C.±2° C.), and the results were listed in Table 7-2.

TABLE-US-00008 TABLE 7-1 F.sub.s (kN) (reduced by Time foam beads/ domain foamed (mS) F.sub.t (kN) microballs) F.sub.s/F.sub.0 Rebound Blank 0.70 96.35 — — — Cotton 0.70 96.87 (F.sub.0) — — — mesh bag Foam beads 1.56 59.55 37.32 38.53% No in PE 1A Foamed 0.81 92.62  4.25  4.39% Yes microballs in F-C13

TABLE-US-00009 TABLE 7-2 F.sub.s (kN) (reduced by Time foam beads/ domain foamed (mS) F.sub.t (kN) microballs) F.sub.s/F.sub.0 Rebound Blank 0.67 60.99 — — — Cotton 0.74 60.31 (F.sub.0) — — — mesh bag Foam beads 4.62 15.29 42.02 69.67% No in PE 1A Foamed 1.11 50.31 10.00 16.58% Yes microballs in F-C13

[0174] Discussion on Impact Resistance of the TPU Foams as Impact Resistant Layers

[0175] From the results in Tables 3 to 5, the F-E1 to F-E3 and F-E14 to F-E18 under the Test Condition A, the F-E4 to F-E8 and F-E19 to F-E25 under the Test Condition B and the F-E9 and F-E13 and F-E26 to F-E32 under the Test Condition C, the impact resistant layers which were composed of the TPU foam of the present disclosure indeed reduced at least 20% of the external impact. It demonstrates that the TPU foam, which is prepared by a foaming process from the TPU comprising the structural unit represented by the Formula (I) can provide a good impact resistance performance to cushion external force effectively.

[0176] In comparison with available impact-resistant products on the market, D3O (i.e. the commercial impact resistant material used by F-C1 and F-C2) is an excellent impact-resistant product. However, from a comparison between F-E2 and F-C2 in Table 3 and a comparison of F-E3, F-E15, F-E16, F-E17 and F-C1 in Table 3, it can be seen that the impact reduced by the TPU foam of the present disclosure with a thinner thickness could be similar to or even more than the impact reduced by D3O. Moreover, F-E1 to F-E3 and F-E14 to F-E18 respectively had a better impact resistance per unit thickness than that of F-C1 and F-C2. That is, the TPU foam has more excellent impact resistance.

[0177] Similarly, from a comparison of F-E4 to F-E8, F-E19 to F-E25 and F-C4 to F-C12 in Table 4 and a comparison of F-E9 to F-E13, F-E26 to F-E32 and F-C13, the TPU foam of the present disclosure also had a better impact resistance per unit thickness. Besides, although the impact resistance of F-C5 was good, it was composed of a composite material containing moisture-curable PUR and glass fibers, which was not a thermoplastic environmentally friendly material. The composite material of F-C5 could neither be reformed after being cured, nor be recycled; therefore, F-C5 could not meet the requirement of circular economy.

[0178] Moreover, from the experiment results in Table 6-1 and Table 6-2, the impact resistant layers with the same or similar thickness could reduce a considerable degree of the external impact no matter in a low temperature environment (close to 0° C., such as 5° C.) or a high temperature environment (e.g. 90° C.). It proves that the TPU foam prepared by a foaming process using the TPU comprising the structural unit represented by the Formula (I) indeed has an impact resistance not restricted by the Tg of the TPU. Further, from the experiment results in Table 6-1 and Table 6-2, it shows that the impact resistance per unit thickness provided by the TPU foams in an environment at a temperature ranging from larger than 0° C. to smaller than 90° C. can exhibit an equivalent performance, which represents same impact resistance.

[0179] In addition, from the experiment results in Table 7-1 and Table 7-2, even though both of foam beads in PE 1A and foamed microballs in F-C13 were TPU foam beads, the TPU foam beads formed by the TPU comprising the structural unit represented by the Formula (I) had a significantly higher impact resistance. Further, the foam beads in PE 1A would not rebound after being hit by an external impact while the foamed microballs of BASF in F-C13 would rebound. It can be seen that their different responses were caused by their different chemical structures as well as their different performances in absorbing stress.

[0180] Impact Resistant Composite Laminate

[0181] Please refer to the impact resistant composite laminate 10 in FIG. 4, one embodiment of the impact resistant composite laminate of the present disclosure which may have a double-layer structure. Specifically, the impact resistant composite laminate 10 has a base layer 12 and a first impact resistant layer 11 disposed on the base layer 12.

[0182] Please refer to the impact resistant composite laminate 10′ in FIG. 5, another embodiment of the impact resistant composite laminate of the present disclosure which may have a three-layer structure. Specifically, the impact resistant composite laminate 10′ has abase layer 12, a first impact resistant layer 11 disposed on the base layer 12, and a surface layer 13 disposed on the first impact resistant layer 11. That is, the first impact resistant layer 11 is sandwiched between the surface layer 13 and the base layer 12.

[0183] Referring to the impact resistant composite laminate 10″ in FIG. 6, another embodiment of the impact resistant composite laminate of the present disclosure may have a three-layer structure. Specifically, the impact resistant composite laminate 10″ sequentially has a first impact resistant layer 11, a base layer 12, and a second impact resistant layer 14. That is, the base layer 12 is sandwiched between the first impact resistant layer 11 and the second impact resistant layer 14.

[0184] The impact resistant composite laminates with a double-layer structure were exemplified below: those impact resistant composite laminates comprised the first impact resistant layer overlapping the base layer in each group of Examples and Comparative Examples.

[0185] The base layers in each group of Examples and Comparative Examples chose one layer from the layer of Reference Example 1 (M-R1) to the layer of Reference Example 8 (M-R8), and the relevant information thereof is as follows.

[0186] 1. M-R1, M-R8: a PET woven fabric with a thickness of 2.5 mm.

[0187] 2. M-R2: a leather with a thickness of 0.86 mm.

[0188] 3. M-R3: a PC rigid plastic layer with a thickness of 1.93 mm and a Shore hardness of 80D; the PC rigid plastic layer was formed by the PC resin (Makrolon 2405, purchased from Bayer AG) through an injection molding process.

[0189] 4. M-R4: a PE rigid plastic layer with a thickness of 1.96 mm and a Shore hardness of 60D; the PE rigid plastic layer was formed by the PE resin (HDPE 7501, purchased from Formosa Plastics Co., Ltd.) through a thermoforming process.

[0190] 5. M-R5, M-R7: a low density polyethylene (LDPE) foam layer with a thickness of 5.25 mm and a Shore hardness of 35 C.

[0191] 6. M-R6: a commercial PET woven cloth with a thickness of 5.7 mm.

[0192] The first impact resistant layers of the impact resistant composite laminates of Examples were as described in Table 8.

TABLE-US-00010 TABLE 8 Example No. of PE No. of the impact resistant first impact composite laminate resistant layer M-E1 PE 4 M-E2 PE 18 M-E3 PE 12 M-E4 PE 4 M-E5 PE 19 M-E6 PE 4 M-E7 PE 20 M-E8 PE 4 M-E9 PE 21 M-E10 PE 22 M-E11 PE 23 M-E12 PE 3 M-E13 PE 24 M-E14 PE 10 M-E15 PE 9 M-E16 PE 25

[0193] The relevant information of the impact resistant layers of Comparative Examples were as follows.

[0194] 1. M-C1, M-C2: the commercial impact resistant material I with a thickness of 7.1 mm, which was taken from D3O (as the same as F-C1).

[0195] 2. M-C3: formed by stacking three layers of commercial styrofoam boards; each layer with a thickness of about 3.2 mm and a density of 0.05 g/cm.sup.3.

[0196] 3. M-C4, M-C6: a shapeable fiberglass layer taken from a commercial baseball elbow pad; wherein the fiberglass layer was composed of a moisture-curable resin and glass fibers; the shapeable fiberglass layer with a thickness of 5.2 mm and a density of 0.9 g/cm.sup.3.

[0197] 4. M-C5: the EVA foam with a thickness of 8 mm, which was taken from a commercial volleyball knee pad (as the same as F-C3).

[0198] 5. M-C7: a PU foam taken from a commercial volleyball knee pad; wherein M-C7 had a thickness of 18 mm.

[0199] 6. M-C8: the EVA foam taken from a commercial knee pad; wherein M-C8 had a thickness of 8.41 mm (as the same as F-C7).

[0200] Analysis 4: Impact Resistance Performance Test for Impact Resistant Composite Laminates

[0201] In Tables 9 to 11, all of the layers of Reference Examples, the impact resistant composite laminates of Examples and Comparative Examples were respectively analyzed by the shock tester which was used in Analysis 2 under the specific test condition, and the resulting “penetrating impact (F.sub.t)”, “reduced impact of the impact resistant layer (F.sub.s′)”, “reduced impact ratio of the impact resistant layer” and the impact resistance per unit thickness of the impact resistant layer were listed in Tables 9 to 11. Besides, in the test for impact resistance, the hammer contacted the outer surface of the base layer (i.e. the surface opposite to the surface contacting the impact resistant layer) after falling.

[0202] The “Blank” test refers to an impact force measured by a free drop of the hammer under a specific test condition to directly hit the platform of the shock tester without any test samples thereon; the impact force measured by Blank test could also be called the “original impact (F.sub.0)”.

[0203] The “penetrating impact (F.sub.t)” refers to a measured impact force, which is a free drop of the hammer under a specific test condition to hit a test sample on the platform of the shock tester.

[0204] The “reference impact (F.sub.0′)” refers to an impact force penetrating through a test sample, which only is the base layer of the impact resistant composite laminate of Examples, measured by a free drop of the hammer under a specific test condition to hit the test sample on the platform of the shock tester.

[0205] The “reduced impact of the impact resistant layer (F.sub.s′)” refers to the impact force that the first impact resistant layer of the test sample dissipates when withstanding an external force under the specific test condition. F.sub.s′ is the difference obtained from subtracting “penetrating impact (F.sub.t)” from “reference impact (F.sub.0′)”. (F.sub.s′=F.sub.0′−F.sub.t)

[0206] The “reduced impact ratio of the impact resistant layer” is a ratio of the “reduced impact of the first impact resistant layer (F.sub.s′)” to the “reference impact (F.sub.0′)”; that is, “reduced impact ratio of the impact resistant layer”=F.sub.s′/F.sub.0′.

[0207] The “impact resistance per unit thickness of the impact resistant layer” was a ratio of the “reduced impact ratio of the impact resistant layer” to the thickness of the first impact resistant layer; that is, “impact resistance per unit thickness of the impact resistant layer”=(F.sub.s′/F.sub.0′)/thickness.

[0208] The layers of M-R1 to M-R6 and the impact resistant composite laminates of M-E1 to M-E12 and M-C1 to M-C5 were all tested for impact resistance under Test Condition A at room temperature (25° C.±2° C.), and the results were listed in Table 9. Moreover, the impact resistant layer of M-C5 was slightly deformed after the impact resistance performance under Test Condition A.

TABLE-US-00011 TABLE 9 Thickness (mm) First (F.sub.s′/F.sub.0′)/ impact Time thick- Base resistant domain F.sub.t F.sub.s′ ness layer layer (mS) (kN) (kN) F.sub.s′/F.sub.0′ (%/mm) Blank — — 0.7 96.35 — — — M-R1 2.5 — 0.71 98.46 — — — M-E1 2.5 8.60 5.47 20.84 77.62 78.83% 9.17 M-E2 2.5 7.81 2.65 33.02 65.44 66.46% 8.51 M-E3 2.5 6.67 2.28 36.55 61.91 62.88% 9.43 M-C1 2.5 7.1  2.78 37.26 61.20 62.16% 8.75 M-R2 0.86 — 0.75 86.92 — — — M-E4 0.86 8.60 5.47 20.84 66.08 76.02% 8.84 M-E5 0.86 8.15 2.31 36.25 50.67 58.29% 7.15 M-C2 0.86 7.1  2.68 37.61 49.31 56.73% 7.99 M-R3 1.93 — 0.71 100.3 — — — M-E6 1.93 8.60 5.72 18.01 82.29 82.04% 9.54 M-E7 1.93 7.95 4.10 31.28 59.01 58.83% 7.40 M-C3 1.93 9.60 0.86 90.29 10.01  9.98% 1.04 M-R4 1.96 — 0.76 90.78 — — — M-E8 1.96 8.60 6.01 16.73 74.05 81.57% 9.48 M-E9 1.96 7.96 2.42 35.61 55.17 60.77% 7.63 M-R5 5.25 — 0.8 82.86 — — — M-E10 5.25 5.65 2.48 41.27 41.59 50.19% 8.88 M-E11 5.25 6.35 3.87 35.04 47.82 57.71% 9.09 M-C4 5.25 5.20 1.70 58.79 24.07 29.05% 5.59 M-R6 5.7 — 0.9 86.2 — — — M-E12 5.7 6.50 3.36 32.25 53.95 62.59% 9.63 M-C5 5.7 8.00 1.19 73.18 13.02 15.10% 1.89

[0209] The layer of M-R7 and the impact resistant composite laminates of M-E13 and M-C6 were all tested for impact resistance under Test Condition B at room temperature (25° C.±2° C.), and the results were listed in Table 10.

TABLE-US-00012 TABLE 10 Thickness (mm) First (F.sub.s′/F.sub.0′)/ impact Time thick- Base resistant domain F.sub.t F.sub.s′ ness layer layer (mS) (kN) (kN) F.sub.s′/F.sub.0′ (%/mm) Blank — — 0.67 60.99 — — — M-R7 5.25 — 0.99 53.57 — — — M-E13 5.25 5.59 5.12 14.48 39.09 72.97% 13.05 M-C6 5.25 5.2  2.53 30.39 23.18 43.27%  8.32

[0210] The layer of M-R8 and the impact resistant composite laminates of M-E14 to M-E16 and M-C7 to M-C8 were all tested for impact resistance under Test Condition C at room temperature (25° C.±2° C.), and the results were listed in Table 11.

TABLE-US-00013 TABLE 11 Thickness (mm) First (F.sub.s′/F.sub.0′)/ impact Time thick- Base resistant domain F.sub.t F.sub.s′ ness layer layer (mS) (kN) (kN) F.sub.s′/F.sub.0′ (%/mm) Blank — — 0.68 37.24 — — — M-R8 2.5 — 1.48 29.3 — — — M-E14 2.5 3.97 6.36 6.92 22.38 76.38% 19.24 M-E15 2.5 4.36 7.65 5.86 23.44 80.00% 18.35 M-E16 2.5 6.70 5.12 8.46 20.84 71.13% 10.62 M-C7 2.5 18 4.06 14.47 14.83 50.61% 2.81 M-C8 2.5 8.41 6.92 10.84 18.46 63.00% 7.49

[0211] From the results in Tables 9 to 11, all of the impact resistant composite laminates indeed reduced at least 20% of the external impact. It demonstrates that the impact resistant composite laminate of the present disclosure is able to provide a good impact resistance.

[0212] In Table 9, F.sub.t of the layer of M-R1 and F.sub.t of the layer of M-R3 were even higher than F.sub.0. The reason may be that the layers of M-R1 and M-R3 had almost no impact resistance; therefore, when they withstood a strong impact under Test Condition A, they would produce a reaction force rather than dissipate a part of the impact.

[0213] Moreover, from a comparison of the “impact resistance per unit thickness of the impact resistant layer” of the impact resistant composite laminates of M-E1 to M-E3 and M-C1 in Table 9, the first impact resistant layers prepared by the TPU foam of the present disclosure exhibited a comparable impact resistance per unit thickness to the commercial impact resistant material “D3O”, and even M-E1 to M-E3 respectively had a better “impact resistance per unit thickness of the impact resistant layer” than that of D3O.

[0214] Similarly, from a comparison of the “impact resistance per unit thickness of the impact resistant layer” of the impact resistant composite laminates of M-E4 to M-E5 and M-C2 in Table 9, the first impact resistant layers prepared by the TPU foam of the present disclosure exhibited a comparable impact resistance per unit thickness to the commercial impact resistant material “D3O”, and even M-E4 had a better “impact resistance per unit thickness of the impact resistant layer” than that of D3O.

[0215] Further, D3O is a composite material, which contains PBDMS evenly distributed in the solid foamed PU elastomer matrix, but D3O is not a thermoplastic environmentally friendly material; in addition, D3O cannot change its shape once it is cured, and it cannot be recycled to satisfy the requirement of circular economy. On the other hand, the TPU foam of the present disclosure can be recycled and reused, thereby meeting the requirement of circular economy.

[0216] In addition, from a comparison between M-E10 and M-C4 in Table 9 and a comparison between M-E13 and M-C6 in Table 10, in the cases of the impact resistant layer having the same or similar thickness, the first impact resistant layers formed by the TPU foam of the present disclosure had a better impact resistance per unit thickness than that of the shapeable fiberglass layer (i.e. the fiberglass layer was composed of a moisture-curable resin and glass fibers).

[0217] In addition, from a comparison between M-E12 and M-C5 in Table 9 and a comparison between M-E14 to M-E16 and M-C8 in Table 11, the first impact resistant layers formed by the TPU foam of the present disclosure obviously had an excellent impact resistance per unit thickness than that of the EVA foam.

[0218] In summary, in view of the aforementioned results of Analyses 1 to 4, the TPU foam obtained by a foaming process from the TPU comprising the structural unit represented by Formula (I) of the present disclosure can provide a good impact resistance when the TPU foam is used as an impact resistant layer; moreover, the impact resistant composite laminate comprising the aforesaid impact resistant layer can even have a better impact resistance per unit thickness, which are proven as the unexpected results.

Application Example 1

[0219] With reference to FIG. 7, a personal protective equipment 1 of Application Example 1 is a wrist bracer. The personal protective equipment 1 may be obtained by the following step. First, the impact resistant layer 11A of F-E4 is pressed and cut to a desired size; next, the cut impact resistant layer 11A is put into a long bag body 20, and a set of connecting elements 30 such as a pair of hook-and-loop fasteners are installed at opposite ends of the bag body 20.

[0220] When the personal protective equipment 1 is put on the user's wrist, the bag body 20 containing the impact resistant layer 11A will be wound around the user's wrist, and hook and loop of the set of connecting elements 30 should be adjusted to an appropriate position for fastening. If the user wants to remove the personal protective equipment 1, the user just needs to separate the set of connecting elements 30.

[0221] The TPU foam of the present disclosure can be easily shaped at a temperature equal to or slightly higher than human body temperature, so the personal protective equipment 1 comprising the impact resistant layer 11A not only fits the corresponding body part covered by the personal protective equipment 1, but also can be repeatedly re-shaped at an elevated temperature. Accordingly, the personal protective equipment 1 has a high practicality.

[0222] In other application examples, the impact resistant layer 11A may be subjected to a hole-punching step prior to putting into the bag body, so the impact resistant layer 11A may have penetrating holes, so as to improve its air permeability.

[0223] In other application examples, the impact resistant layer 11A in the personal protective equipment 1 of Application Example 1 may be replaced to an impact resistant composite laminate comprising a TPU foam of the present disclosure, such as the impact resistant composite laminate 10 shown in FIG. 4, the impact resistant composite laminate shown 10′ in FIG. 5, and the impact resistant composite laminate 10″ shown in FIG. 6.

[0224] Even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and features of the disclosure, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.