Supercritical thermoplastic foam elastomer material and preparation method and application thereof

Abstract

Disclosed are a supercritical thermoplastic foam elastomer material and a preparation method and application thereof, belonging to the technical field of foam materials. The supercritical thermoplastic foam elastomer material comprises a thermoplastic elastomer, talc powder, a chain extender and an auxiliary material. According to the invention, a TPU raw material is injection-molded into a shape corresponding to a midsole, and can be directly molded after foaming without being cut. In addition, because the TPU raw material is integrally formed by injection molding, the particles of the popcorn material will not be adhered, and the defect of adhesion between the particles can be ameliorated.

Claims

1. A supercritical thermoplastic foam elastomer material, comprising the following components in parts by weight: 80-120 parts of a thermoplastic elastomer, 3-7 parts of talcum powder, 8-12 parts of a chain extender and 2-6 parts of an auxiliary agent.

2. The supercritical thermoplastic foam elastomer material according to claim 1, wherein the thermoplastic elastomer is aromatic polyether TPU, aliphatic polyester TPU, aliphatic polyether TPU or aromatic polyester TPU.

3. The supercritical thermoplastic foam elastomer material according to claim 1, wherein the chain extender is 1,4-butanediol, ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol or glycerol.

4. The supercritical thermoplastic foam elastomer material according to claim 1, wherein the auxiliary agent is stearic acid or industrial oil.

5. A preparation method of the supercritical thermoplastic foam elastomer material according to claim 1, comprising the following steps: step 1, weighing raw materials accord to a formula ratio, blending a thermoplastic elastomer, talcum powder, a chain extender and an auxiliary agent by using a double-screw extrusion device, and modifying the thermoplastic elastomer at a temperature higher than a melting point of the material; step 2, carrying out an injection molding or extrusion process on the product obtained in step 1 at a temperature higher than a glass softening point and lower than the melting point to obtain a special-shaped thermoplastic elastomer piece or sheet; step 3, reheating the special-shaped piece or sheet obtained in step 2 to a temperature higher than the glass softening point of the material, baking the special-shaped piece or sheet for 2-8 h at a temperature lower than a glass transition temperature of the material, and carrying out normalizing treatment; step 4, in an autoclave, introducing N.sub.2 and water vapor in an autoclave body to permeate the special-shaped TPU piece or sheet placed in the autoclave body, forming a polymer/gas homogeneous system after a certain time, breaking an equilibrium state of the polymer/gas homogeneous system in the material by using a heating/depressurization method, forming a bubble nuclei in the material and growing and shaping the bubble nuclei; and step 5, carrying out compression molding on the TPU small foam material obtained in step 4.

6. The preparation method of the supercritical thermoplastic foam elastomer material according to claim 5, wherein a temperature inside the reactor in step 4 is greater than a boiling point of water.

7. The preparation method of the supercritical thermoplastic foam elastomer material according to claim 5, wherein a volume ratio of N.sub.2 to water vapor in step 4 is (3-7):1.

8. The preparation method of the supercritical thermoplastic foam elastomer material according to claim 5, wherein the pressure in step 4 is greater than 45 Mpa.

9. The preparation method of the supercritical thermoplastic foam elastomer material according to claim 5, wherein the time in step 4 is 4-8 h.

10. An application of the supercritical thermoplastic foam elastomer material prepared by the preparation method of the supercritical thermoplastic foam elastomer material according to claim 5 in a shoe sole.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024] In order to make the objects, technical solutions and advantages of the invention more comprehensible, the present invention will be further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

[0025] The example of the present invention provides a preparation method of a supercritical thermoplastic foam elastomer, comprising the following steps: [0026] step 1, weighing 100 parts of aromatic polyether 5039, 5 parts of talcum powder, 10 parts of 1,4-butanediol and 4 parts of stearic acid accord to the above formula, blending the raw materials by using a double-screw extrusion device, and modifying the polyether 5039 at a temperature higher than a melting point of the material; [0027] step 2, carrying out an injection molding or extrusion process on the product obtained in step 1 at a temperature higher than a glass softening point (120? C.) and lower than the melting point (180? C.) to obtain a special-shaped thermoplastic elastomer piece or sheet; [0028] step 3, reheating the special-shaped piece or sheet obtained in step 2 to a temperature higher than the glass softening point (120? C.) of the material, baking the special-shaped piece or sheet for 4 h at a temperature lower than a glass transition temperature of the material, and carrying out normalizing treatment; and pretreating the special-shaped TPU piece or sheet to eliminate the stress of the special-shaped TPU piece or sheet; [0029] step 4: in an autoclave, introducing N.sub.2 and water vapor into an autoclave body to permeate the special-shaped TPU piece or sheet placed in the autoclave body, wherein a volume ratio of N.sub.2 to water vapor is 5:1, the time is 6 h, the pressure is greater than 45 Mpa, and the temperature is 120? C.; forming a polymer/gas homogeneous system, breaking an equilibrium state of the polymer/gas homogeneous system in the material by using a heating/depressurization method, forming a bubble nuclei in the material and growing and shaping the bubble nuclei; and [0030] step 5, carrying out compression molding on the TPU small foam material obtained in step 4.

Example 2

[0031] The example of the present invention provides a preparation method of a supercritical thermoplastic foam elastomer, comprising the following steps: [0032] step 1, weighing 80 parts of aliphatic polyester A902, 3 parts of talcum powder, 8 parts of diethylene glycol and 3 parts of industrial oil accord to the above formula, blending the raw materials by using a double-screw extrusion device, and modifying the aliphatic polyester, wherein the temperature is required to be higher than the melting point (180? C.) of the material; [0033] step 2, carrying out the injection molding or extrusion process on the product obtained in step 1 at a temperature higher than a glass softening point (120? C.) and lower than the melting point (180? C.) to obtain a special-shaped thermoplastic elastomer piece or sheet; [0034] step 3, reheating the special-shaped piece or sheet obtained in step 2 to a temperature higher than the glass softening point of the material, baking the special-shaped piece or sheet for 4 h at a temperature lower than a glass transition temperature of the material, and carrying out normalizing treatment; and pretreating the special-shaped TPU piece or sheet to eliminate the stress of the special-shaped TPU piece or sheet; [0035] step 4: in an autoclave, introducing N.sub.2 and water vapor into an autoclave body to permeate the special-shaped TPU piece or sheet placed in the autoclave body, wherein a volume ratio of N.sub.2 to water vapor is 3:1, the time is 4 h, the pressure is greater than 45 Mpa, and the temperature is 120? C.; forming a polymer/gas homogeneous system, breaking the equilibrium state of the polymer/gas homogeneous system in the material by using a heating/depressurization method, forming a bubble nuclei in the material and growing and shaping the bubble nuclei; and [0036] step 5, carrying out compression molding on the TPU small foam material obtained in step 4.

Example 3

[0037] The example of the present invention provides a preparation method of a supercritical thermoplastic foam elastomer, comprising the following steps: [0038] step 1, weighing 120 parts of aliphatic polyether H190A, 7 parts of talcum powder, 12 parts of neopentyl glycol and 6 parts of stearic acid accord to the above formula, blending the raw materials by using a double-screw extrusion device, and modifying the aliphatic polyether, wherein the temperature is required to be higher than the melting point (125? C.) of the material; [0039] step 2, carrying out the injection molding or extrusion process on the product obtained in step 1 at a temperature higher than a glass softening point (125? C.) and lower than the melting point (185? C.) to obtain a special-shaped thermoplastic elastomer piece or sheet; [0040] step 3, reheating the special-shaped piece or sheet obtained in step 2 to a temperature higher than the glass softening point of the material, baking the special-shaped piece or sheet for 4 h at a temperature lower than a glass transition temperature of the material, and carrying out normalizing treatment; and pretreating the special-shaped TPU piece or sheet to eliminate the stress of the special-shaped TPU piece or sheet; [0041] step 4: in an autoclave, introducing N.sub.2 and water vapor into an autoclave body to permeate the special-shaped TPU piece or sheet placed in the autoclave body, wherein a volume ratio of N.sub.2 to water vapor is 7:1, the time is 8 h, the pressure is greater than 45 Mpa, and the temperature is 120? C.; forming a polymer/gas homogeneous system, breaking the equilibrium state of the polymer/gas homogeneous system in the material by using a heating/depressurization method, forming a bubble nuclei in the material and growing and shaping the bubble nuclei; and [0042] step 5, carrying out compression molding on the TPU small foam material obtained in step 4.

Comparative Example 1

[0043] (1) 100 parts of aromatic polyether 5039 were weighed and placed in an autoclave, and a supercritical fluid was permeated into the aromatic polyether 5039 particle raw material at a pressure greater than 45 Mpa and a temperature of 120? C. to form a polymer/gas homogeneous system. [0044] (2) The equilibrium state of the polymer/gas homogeneous phase system in the material was broken by using a temperature rise and pressure reduction method, and a bubble nuclei was formed in the material and grown and shaped to obtain a TPU foam material. [0045] (3) A TPU popcorn material is formed after the pressurization and heating pretreatment.

Comparative Example 2

[0046] (1) 100 parts of aromatic polyether 5039 were weighed and placed in an autoclave, and a supercritical fluid was permeated into the aromatic polyether 5039 sheet at a pressure greater than 45 Mpa and a temperature of 120? C. to form a polymer/gas homogeneous system. [0047] (2) The equilibrium state of the polymer/gas homogeneous phase system in the material was broken by using a temperature rise and pressure reduction method, and a bubble nuclei was formed in the material and grown and shaped to obtain a TPU foam sheet. [0048] (3) The TPU foam sheet was cut into a required midsole size and polished, and then subjected to compression molding on a CMP machine.

Experimental Example

[0049] In order to better illustrate the characteristics of the supercritical foamed thermoplastic elastomer material of the present invention, the properties of the materials of Examples 1 to 3 and Comparative Examples 1 to 2 were determined, and the results are shown in Table 1.

TABLE-US-00001 TABLE 1 Properties of supercritical thermoplastic foam elastomer materials of Examples 1 to 3 and Comparative Examples 1 to 2 Specific Compression Tensile Experimental gravity Rebound Hardness ratio strength example (g/cm.sup.3) (%) (C) (%) (kgf/cm.sup.2) Example 1 0.101 70 40 20 14 Example 2 0.092 75 42 17 15 Example 3 0.086 77 38 19 15 Comparative 0.122 65 42 35 10 Example 1 Comparative 0.141 68 45 30 11 Example 2

[0050] It can be seen from Table 1 that the product of the present invention has good mechanical strength and comfort.

[0051] The above description is only preferred embodiments of the present invention, and is not intended to limit the present invention. Any modification, equivalent substitution or improvement within the spirit and principle of the present invention shall be included in the scope of the invention.