Modified supporting layer TPU air bag and preparation method thereof

Abstract

The invention relates to a modified supporting layer TPU (thermoplastic polyurethane) air bag and a preparation method thereof, belongs to the technical field of high polymer material preparation, and provides the modified supporting layer TPU air bag aiming at the problem that the hardness and the strength of an existing mattress supporting layer air bag cannot be both considered, the modified supporting layer TPU air bag is prepared from the following raw materials in mass ratio: thermoplastic polyurethane elastomer (TPU) and master batch in a mass ratio of 100: (4-12), wherein the master batch comprises the following raw materials: thermoplastic polyurethane elastomer (TPU), a reinforcing agent, a nucleating agent, an antioxidant and a release agent in a mass ratio of 100: (5-30): (3-7): (4-9): (2-5), and the reinforcing agent is an amino hyperbranched polymer. In the processing process of thermoplastic polyurethane elastomer (TPU), ester groups are easily attacked by water molecules and hydrolyzed to generate carboxylic acid, and amino-terminated hyperbranched polymer reacts with carboxylic acid to generate micro-crosslinking, so that the strength of the TPU air bag can meet the use requirement, and the hardness of the TPU air bag is relatively proper.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer material preparation, and particularly relates to a modified support layer TPU airbag and a preparation method thereof. Background Art

[0002] Traditional mattresses usually use steel springs to increase the sense of support. Its disadvantage is that the elasticity cannot be adjusted and it cannot meet the usage requirements of different people. To increase the comfort experience and meet various usage requirements as much as possible, TPU airbags are used instead of traditional steel springs. By adjusting the air pressure inside the airbag, different elasticities can be achieved, so as to adapt to the usage requirements of different people.

[0003] The airbag of the mattress support layer should have a certain support strength to effectively support the human body and ensure the normal physiological curve of the body during sleep. At the same time, it cannot be too hard, otherwise it will affect the comfort of sleep, cause excessive compression of various parts of the body, and cause discomfort. If an airbag is made of low-hardness TPU, although it can meet the requirement of softness, its pressure resistance is not enough, which may cause the airbag to deform or even be damaged prematurely, thus greatly shortening the service life of the mattress and at the same time unable to ensure a long-term stable support effect. In order to balance hardness and strength, it is necessary to modify the existing TPU material. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a modified support layer TPU airbag and a preparation method thereof. The present invention preferably uses an amino-terminated hyperbranched polymer as an enhancer to modify and enhance TPU, and prepares a TPU that can balance hardness and strength.

[0005] To solve the above technical problems, the present invention provides a modified support layer TPU airbag, and its raw materials are in a mass ratio including: the mass ratio of thermoplastic polyurethane elastomer to masterbatch is 100:(4 - 12); wherein the raw materials of the masterbatch are in a mass ratio including: thermoplastic polyurethane elastomer, enhancer, nucleating agent, antioxidant, and release agent are 100:(5 - 30):(3 - 7):(4 - 9):(2 - 5) and are prepared into pellets through mixing and reaction. The enhancer is an amino-terminated hyperbranched polymer.

[0006] The nucleating agent can significantly accelerate the crystallization rate, increase the crystallinity, and promote the refinement of the grain size; the antioxidant can effectively terminate the free radical chain reaction in the polymer material, prevent the initiation and growth of the chain caused by macromolecular free radicals generated by heat, light, etc., thereby slowing down the degradation process of the polymer material. It can improve the stability of the modified TPU airbag and extend its service life; the release agent facilitates the detachment of the modified TPU airbag from the mold and reduces the demolding difficulty.

[0007] The thermoplastic polyurethane elastomer is used as a carrier in the masterbatch, and additives are added and dispersed evenly to prepare the masterbatch. Then, this masterbatch is added to the thermoplastic polyurethane elastomer, so that the compatibility between the additive and the thermoplastic polyurethane elastomer is good, and thus the prepared airbag has uniform performance and few defects.

[0008] The components used in the masterbatch include thermoplastic polyurethane elastomer, which is the same as the main component of the modified support layer TPU airbag, facilitating the uniform dispersion of other components in the masterbatch and avoiding local aggregation.

[0009] During the TPU processing, the ester group is easily attacked by water molecules and hydrolyzed to produce carboxylic acid. The reinforcing agent in the masterbatch is an amino-terminated hyperbranched polymer, which has amino groups at the ends of the hyperbranched polymer. These amino groups at the ends of the hyperbranched polymer react with the carboxylic acid generated during the TPU processing to produce micro-crosslinking, thereby ensuring that the strength of the TPU airbag meets the usage requirements and its hardness is appropriate to balance hardness and strength.

[0010] Furthermore, the thermoplastic polyurethane elastomer is polyester TPU. Polyester TPU has high tear strength and toughness and can withstand large external forces without being easily broken.

[0011] Furthermore, to improve the strength and produce micro-crosslinking by reacting with the carboxylic acid generated by hydrolysis during the TPU processing, the added reinforcing agent is amino-terminated hyperbranched polyamide.

[0012] Furthermore, to improve the strength, a nucleating agent is added, and the nucleating agent is Milliken nucleating agent Hyperform PN-68L. This nucleating agent can significantly increase the crystallization rate and shorten the crystallization period, thereby improving the matrix strength.

[0013] Furthermore, to facilitate demolding during injection, a demolding agent is added, and the demolding agent is ethylene oxide wax.

[0014] Furthermore, to improve the yellowing resistance of the material, an antioxidant is added, and the antioxidant is antioxidant 168.

[0015] A preparation method for a modified support layer TPU airbag includes the following steps:

[0016] (1) Prepare the masterbatch: According to the above ratio, mix the thermoplastic polyurethane elastomer, amino-terminated hyperbranched polymer, nucleating agent, antioxidant, and demolding agent, and then make the masterbatch by granulation;

[0017] (2) Mix the masterbatch and TPU according to the above mass ratio;

[0018] (3) Prepare the modified support layer TPU airbag by injection of the mixture in an injection molding machine.

[0019] Further, the granulation temperature is 170 - 190 °C.

[0020] Further, the mixing temperature is normal temperature.

[0021] Further, the injection temperature is 180 - 200 °C.

[0022] Beneficial effects: This application is a modified support layer TPU airbag and its preparation method. By reacting an amino - terminated hyperbranched polymer with carboxylic acid generated during the TPU processing to produce micro - crosslinking, and further regulating the crystal structure through a nucleating agent, it can ensure that the strength of the TPU airbag meets the use requirements and its hardness is appropriate. Description of the Drawings

[0023] Figure 1 It is a front - view structure schematic diagram during testing;

[0024] Figure 2 It is a diagonal - view structure schematic diagram during testing.

[0025] Specific Embodiment Modes

[0026] To make the technical solutions and advantages of the present invention clearer and more distinct, the following examples are given to further elaborate on the present invention in detail.

[0027] Example 1

[0028] Polyester TPU, amino - terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN - 68L, antioxidant 168, and ethylene oxide wax were mixed at normal temperature according to a mass ratio of 100:40:5:6:4; then granulated at 180 °C using a parallel twin - screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch were mixed at normal temperature according to a ratio of 100:10 to make a mixture; the mixture was injected into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0029] Example 2

[0030] Polyester TPU, amino - terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN - 68L, antioxidant 168, and ethylene oxide wax were mixed at normal temperature according to a mass ratio of 100:30:5:6:4; then granulated at 180 °C using a parallel twin - screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch were mixed at normal temperature according to a ratio of 100:10 to make a mixture; the mixture was injected into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0031] Example 3

[0032] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax are mixed at room temperature in a mass ratio of 100:20:5:6:4; then granulated at 180 °C using a parallel twin-screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch are mixed at room temperature in a ratio of 100:10 to form a mixture; the mixture is injection-molded into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0033] Example 4

[0034] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax are mixed at room temperature in a mass ratio of 100:10:5:6:4; then granulated at 180 °C using a parallel twin-screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch are mixed at room temperature in a ratio of 100:10 to form a mixture; the mixed raw materials are injection-molded into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0035] Example 5

[0036] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax are mixed at room temperature in a mass ratio of 100:20:2:6:4; then granulated at 180 °C using a parallel twin-screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch are mixed at room temperature in a ratio of 100:10 to form a mixture; the mixed raw materials are injection-molded into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0037] Example 6

[0038] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax are mixed at room temperature in a mass ratio of 100:20:5:6:4; then granulated at 170 °C using a parallel twin-screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch are mixed at room temperature in a ratio of 100:6 to form a mixture; the mixed raw materials are injection-molded into a modified support layer TPU airbag at 190 °C using an injection molding machine.

[0039] Example 7

[0040] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax were mixed at room temperature in a mass ratio of 100:20:3:6:4; then granulated at 180 °C using a parallel twin-screw extruder to prepare masterbatch; polyester TPU and the obtained masterbatch were mixed at room temperature in a mass ratio of 100:10 to form a mixture; the mixed raw materials were injection-molded into a modified support layer TPU airbag at 190 °C using an injection molding machine.

[0041] The experimental conditions and test results are all recorded in Table 1.

[0042] Example 8

[0043] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax were mixed at room temperature in a mass ratio of 100:5:7:4:5; then granulated at 180 °C using a parallel twin-screw extruder, and polyester TPU and the obtained masterbatch were mixed at room temperature in a mass ratio of 100:4; the mixed raw materials were injection-molded into a modified support layer TPU airbag at 180 °C using an injection molding machine.

[0044] Example 9

[0045] Polyester TPU, amino-terminated hyperbranched polyamide, Milliken nucleating agent Hyperform PN-68L, antioxidant 168, and ethylene oxide wax were mixed at room temperature in a mass ratio of 100:30:5:9:2; then granulated at 190 °C using a parallel twin-screw extruder, and polyester TPU and the obtained masterbatch were mixed at room temperature in a mass ratio of 100:12; the mixed raw materials were injection-molded into a modified support layer TPU airbag at 200 °C using an injection molding machine.

[0046] Comparative Example

[0047] Unmodified TPU was injection-molded into a mattress support layer airbag at 180 °C using an injection molding machine.

[0048] The airbags of the examples and the comparative example were Figure 1 tested for pressure resistance and hardness using the indicated device, and the experimental conditions and test results are all recorded in Table 1. As Figure 1 and Figure 2 shown.

[0049] Table 1

[0050] Examples and Comparative Examples Proof Pressure Value (KPa) Hardness (A) Example 1 90 80 Example 2 88 77 Example 3 83 76 Example 4 75 75 Example 5 81 76 Example 6 76 75 Example 7 81 75 Example 8 70 74 Example 9 89 77 Comparative Example 66 74

[0051] As can be seen from the data in Table 1, in the examples, amino hyperbranched polymers were added, and the pressure resistance of the airbag increased while the hardness changed little. From Examples 1-4, it can be seen that within a certain range, as the addition amount of the terminal amino hyperbranched polymer increases, the pressure resistance of the airbag improves. However, when the addition amount is too large, the increase in pressure resistance is not obvious and the hardness increases. This indicates that during the TPU processing, the ester group is easily attacked by water molecules, hydrolyzed to produce carboxylic acid, and the carboxylic acid reacts with the amino group to produce micro-crosslinking, increasing the strength of TPU with little impact on hardness and improving the pressure resistance of the prepared airbag. Comparing Examples 3 and 5, as the nucleating agent Hyperform PN-68L increases, the pressure resistance of the prepared airbag also increases to a certain extent. Examples 6, 8, and 9 are boundary values, and it can be seen from these examples that even under boundary conditions, relatively excellent performance indicators can be achieved.

[0052] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the drawings and the above specific implementation manner. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A modified support layer TPU airbag, characterized in that, Its raw materials by mass ratio include: The mass ratio of thermoplastic polyurethane elastomer to masterbatch is 100:(4 - 12); Among them, the raw materials of the masterbatch by mass ratio include: thermoplastic polyurethane elastomer, reinforcing agent, nucleating agent, antioxidant, release agent in a ratio of 100:(5 - 30):(3 - 7):(4 - 9):(2 - 5), and the reinforcing agent is an amino - terminated hyperbranched polymer.

2. The modified support layer TPU airbag according to claim 1, wherein The thermoplastic polyurethane elastomer is polyester TPU.

3. The modified support layer TPU airbag according to claim 1 or 2, characterized in that, The reinforcing agent is amino - terminated hyperbranched polyamide.

4. The modified support layer TPU airbag according to claim 1 or 2, characterized in that The nucleating agent is Milliken nucleating agent Hyperform PN - 68L.

5. The modified support layer TPU airbag according to claim 1 or 2, characterized in that, The release agent is ethylene oxide wax.

6. The modified support layer TPU airbag according to claim 1 or 2, characterized in that, The antioxidant is antioxidant 168.

7. A preparation method of a modified support layer TPU airbag, characterized in that, It includes the following steps: (1) Prepare the masterbatch: Add the reinforcing agent, nucleating agent, antioxidant, and release agent to the thermoplastic polyurethane elastomer, and make the masterbatch by granulation; among them, the mass ratio of each substance is thermoplastic polyurethane elastomer, reinforcing agent, nucleating agent, antioxidant, release agent 100:(5 - 30):(3 - 7):(4 - 9):(2 - 5); (2) Mix the thermoplastic polyurethane elastomer and the masterbatch in a mass ratio of 100:(4 - 12) to make a mixture; (3) Use the mixture to inject and prepare a modified support layer TPU airbag.

8. The preparation method of the modified support layer TPU airbag according to claim 7, characterized in that, The granulation temperature is 170 - 190 °C.

9. The preparation method of the modified support layer TPU airbag according to claim 7, characterized in that, The mixing temperature is room temperature.

10. The preparation method of the modified support layer TPU airbag according to claim 7, characterized in that, The injection temperature is 180 - 200 °C.

Images