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US-12624148-B2 - Thermoplastic polyurethane foam and impact resistant composite laminate comprising the same

US12624148B2US 12624148 B2US12624148 B2US 12624148B2US-12624148-B2

Abstract

Provided are a thermoplastic polyurethane foam and an impact resistant composite laminate. The thermoplastic polyurethane comprises a structural unit represented by Formula (I): wherein each R independently is an alkylene group having 2 to 8 carbon atoms or —CH 2 CH 2 OCH 2 CH 2 — or —CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 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.

Inventors

  • Chiu-Peng Tsou
  • Zhen-Wei Chen
  • Ting-Ti HUANG
  • Sheng-Mao Tseng

Assignees

  • SUNKO INK CO., LTD.

Dates

Publication Date
20260512
Application Date
20220705
Priority Date
20220112

Claims (18)

  1. 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): in Formula (I), each R independently is an alkylene group having 2 to 8 carbon atoms, —CH 2 CH 2 OCH 2 CH 2 — or —CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 —; n is a number from 3.57 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. 2 . The thermoplastic polyurethane foam according to claim 1 , wherein the thermoplastic polyurethane comprises a structural unit represented by Formula (II): in Formula (II), each R 1 independently is an alkylene group having 2 to 8 carbon atoms or —CH 2 CH 2 OCH 2 CH 2 — or —CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 —; R 2 is and n is a number from 3.57 to 13.
  3. 3 . The thermoplastic polyurethane foam according to claim 2 , wherein the thermoplastic polyurethane comprises a first thermoplastic polyurethane with the structural unit represented by Formula (II) in which R 1 is —CH 2 CH 2 OCH 2 CH 2 — and R 2 is a second thermoplastic polyurethane with the structural unit represented by Formula (II) in which R 1 is —(CH 2 ) 6 — and R 2 is a third thermoplastic polyurethane produced by a diol with a structural unit represented by Formula (I), polyethylene glycol, butanediol and methylene diphenyl diisocyanate, a fourth 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. 4 . The thermoplastic polyurethane foam according to claim 1 , wherein the foaming process is a physical foaming process.
  5. 5 . The thermoplastic polyurethane foam according to claim 4 , wherein the physical foaming process is a supercritical foaming molding.
  6. 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. 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. 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. 9 . The thermoplastic polyurethane foam according to claim 7 , wherein the thermoplastic polyurethane foam achieves Level 1 of European Standard EN1621-1:2012.
  10. 10 . The thermoplastic polyurethane foam according to claim 1 , wherein the thermoplastic polyurethane foam has a density ranging from 0.15 g/cm 3 to 1.10 g/cm 3 .
  11. 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. 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. 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. 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. 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. 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. 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. 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

CROSS-REFERENCE TO RELATED APPLICATION Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of the priority to Taiwan Patent Application No. 111101309, filed on Jan. 12, 2022. The content of the prior application is incorporated herein by its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a thermoplastic polyurethane (TPU) foam, and more particular to a TPU foam used as an impact resistant layer. The present disclosure also relates to an impact resistant composite laminate comprising the same. 2. Description of the Prior Arts Generally speaking, grips of hand tools, walking sticks, clubs, guns, bicycles, motorcycles and multiple sport goods are made of hard materials such as metals, rigid plastics and woods. Accordingly, vibrations are directly transmitted to the users' hands when the grips are in use, and therefore the users will be uncomfortable after holding these grips for a long time. In addition, while standing, walking and exercising, people's feet not only support the weight of the body but also withstand the reaction force from the ground where the feet tread. Some muscles, tendons and bones continuously withstand a force from the weight of the body because of sitting, lying down or maintaining a posture for a prolonged period of time. A person may fall over during an activity, causing the body to hit against the ground and get injured. An athlete's body may be injured because of a high impact hit during exercise such as catching a ball, hitting a ball, bumping or falling over. Further, fragile goods or precision instruments may be damaged by vibrations or collision. In order to solve the problems, industries, such as footwear, sports protection, instrument protection and medical protection, hope to develop protective products which can effectively dissipate vibrations, resist impact and satisfy the need of lightweight. For example, U.S. Pat. No. 5,456,658A provides a custom-fitting body part protector. The body part protector has a protective layer composed of a glass fiber impregnated with a moisture-curable resin. The body part protector is sealed in an outer moisture-proof protective pouch until the protective layer of the body part protector covers the body part to be protected. The initially flexible protective layer may quickly harden upon curing to form a rigid pad structure in the presence of sufficient moisture. Since the protective layer covers a body part to be protected from the beginning, the pad formed by the cured protective layer maintains the molded structure which fits the body part. However, the moisture-curable resin cannot be reshaped anymore once fully cured. U.S. Pat. No. 7,381,460B2 provides an energy absorbing composite, which relates to the famous impact protection material, D3O. The energy absorbing composite contains a solid foamed synthetic elastomeric polyurethane (PU) matrix, and polyborodimethylsiloxane (PBDMS) is added as a dilatant and is dispersed throughout the matrix during the manufacture of the matrix. The resulting energy absorbing composite is resiliently compressible. In recent years, people pay a great attention to sustainable development; therefore, the circular economy focusing on “resource recycling and reuse” is booming, and the footwear and sports equipment industries actively participate in this trend. If environmental-friendly thermoplastic elastomer materials such as thermoplastic polyester resins and TPU are used to replace environmentally unfriendly materials, such as PUs and thermosetting silicones, it is conducive to recycle the impact protection materials from the waste, and the model of green consumption behavior can be constructed. JP2017-197736A provides a polyester resin composition for vibration-damping material. The composition includes a thermoplastic polyester resin (A) constituted of a dicarboxylic acid component and a diol component, a plasticizer (B) of a diphenyl compound represented by a specified structure, and an inorganic filler (C). TW 202022030A filed by Basf SE provides foam beads formed by a composition comprising: a TPU including a structural unit derived from polytetramethylene ether glycol (PTMEG), a styrene polymer and a specific toughness modifier. The molded article made from the aforesaid foam beads has a resilience of higher than 55%; however, this disclosure does not teach the impact resistance thereof. One person skilled in the art would recognize that the impact resistance of the foam cannot be directly inferred from the resilience of the foam. In addition, TW200704662A provides a flexible PU foam, produced by a process which comprises reacting a polyol mixture with a polyisocyanate compound in the presence of a urethane-forming catalyst, a blowing agent and a foam stabilizer; wherein the polyol mixture comprises a polyether-based polyol and a monool. The flexible PU foam is a cross-linked thermosetting plastic; without using a plasticizer, the re