Light non-slip TPU (thermoplastic polyurethane) foaming leather for racket handle and preparation method thereof

Abstract

The invention relates to the technical field of TPU, in particular to light non-slip TPU foaming leather for a racket handle and a preparation method of the light non-slip TPU foaming leather. The light non-slip TPU foaming leather for the racket handle comprises release paper and a TPU foaming film arranged on the upper end face of the release paper. The light anti-slip TPU foaming leather for the racket handle has the advantages of being good in softness, excellent in abrasion resistance and dry and wet aging performance, good in tensile property, still good in static friction coefficient after absorbing water, capable of well absorbing sweat generated by hands of athletes and still good in anti-slip effect after absorbing water. The preparation method of the light anti-slip TPU foaming leather for the racket handle is simple in process, easy to control in operation and beneficial to industrial mass production, and the prepared TPU foaming leather for the racket handle with the light anti-slip function is stable in quality and excellent in comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the technical field of TPU, and particularly relates to a lightweight anti-slip TPU foam leather for a racket handle and a preparation method thereof. Background Art

[0002] A sweatband is a layer of wrapping cloth on the handgrip of a badminton racket or a tennis racket, and has functions of anti-slip, sweat absorption, and improving the holding feel. The sweatband is generally composed of glue or towel glue made of TPU foam leather material. After the existing TPU sweatband absorbs human sweat, it will cause the hand to slip or even the athlete to drop the racket. There are mainly two categories of methods to increase the anti-slip performance of the existing TPU sweatband: one is to change the shape or winding method of the sweatband, and increase the friction force through mechanical improvements such as changing the contact area with the handgrip. The improvement methods are diverse, but it is easy to cause a decrease in the holding comfort; the other is to use an anti-slip coating on the surface of the PU sweatband. The commonly used one is to print ink patterns. The ink consumption is small and it can be repeatedly sprayed, so it has become an important direction for increasing the anti-slip performance of the sweatband. However, since the traditional ink particles are relatively large, it will cause the pores in the structure of the PU sweatband to be blocked, and the anti-slip function is prone to decline. Therefore, it is necessary to develop a lightweight anti-slip TPU foam leather for a racket handle. Summary of the Invention

[0003] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a lightweight anti-slip TPU foam leather for a racket handle. The lightweight anti-slip TPU foam leather for a racket handle has better softness, excellent wear resistance and dry and wet aging performance, and also takes into account the characteristics of strong tensile performance. Moreover, it still has a good static friction coefficient after absorbing water, that is, the TPU foam film still has good friction performance after absorbing water, can well absorb the sweat on the hand of the athlete due to exercise, and still has a good anti-slip effect after absorbing water, providing a good holding feeling and control force for the user.

[0004] The preparation method of the lightweight anti-slip TPU foam leather for a racket handle of the present invention has a simple process, easy to control operation, is conducive to large-scale industrial production, and the obtained lightweight anti-slip TPU foam leather for a racket handle has stable quality, better softness, excellent wear resistance and dry and wet aging performance, and also takes into account the characteristics of strong tensile performance. Moreover, it still has a good static friction coefficient after absorbing water, and the comprehensive performance is superior.

[0005] The purpose of the present invention is achieved by the following technical solutions: A lightweight anti-slip TPU foam leather for a racket handle includes a release paper and a TPU foam film provided on the upper surface of the release paper.

[0006] In the above technical solution, the thickness of the TPU foam film is 0.2 - 0.5 mm, and the density of the TPU foam film is 0.28 - 0.3 g / cm 3 .

[0007] In the above technical solution, the TPU foamed film comprises raw materials in the following parts by weight: 80 - 120 parts of TPU particles, 22 - 32 parts of SEBS rubber, 18 - 28 parts of polyolefin elastomer, 15 - 23 parts of silica-modified polyvinyl alcohol, 12 - 18 parts of polyurethane acrylate, 1 - 3 parts of foaming agent, 1 - 2 parts of vulcanizing agent, and 1 - 2 parts of antioxidant.

[0008] In the above technical solution, the preparation method of each part of the silica-modified polyvinyl alcohol comprises the following steps:

[0009] (S1) Dissolve PVA powder in deionized water, and magnetically stir in a water bath at 96 - 97 °C for 3 - 4 h until the PVA powder is completely dissolved, to obtain a PVA aqueous solution with a mass fraction of 9 - 11%;

[0010] (S2) Add silica sol and silica powder to the PVA aqueous solution, stir for 50 - 70 min, then place it in a drying oven at 40 - 50 °C until constant weight, and finally grind it into powder to obtain silica-modified polyvinyl alcohol.

[0011] In the above technical solution, the weight ratio of the PVA aqueous solution, silica sol, and silica powder is 100:6 - 8:5 - 7.

[0012] In the above technical solution, the preparation method of the silica sol comprises the following steps: Prepare tetraethyl orthosilicate, deionized water, and absolute ethanol according to a molar ratio of 1:3.8 - 4.2:3.8 - 4.2, then adjust the pH value to 1 - 2 with concentrated hydrochloric acid, and stir at 30 - 40 °C at 280 - 320 r / min for 25 - 40 min to obtain silica sol.

[0013] In the above technical solution, the preparation method of the silica powder comprises the following steps: Put the silica sol obtained above into an oven at 80 - 100 °C for 35 - 50 h to obtain silica gel powder, and sinter it at 500 - 700 °C in a muffle furnace with a heating rate of 8 - 12 °C / min for 2 - 4 h to obtain calcined silica powder.

[0014] In the above technical solution, the antioxidant is 2-mercaptobenzimidazole. The vulcanizing agent is dicumyl peroxide. The foaming agent is bicarbonate.

[0015] In the above technical solution, the preparation method of the lightweight anti-slip TPU foamed leather for the racket handle comprises the following steps:

[0016] (1) By weight, pour TPU particles, SEBS rubber, polyolefin elastomer, silica-modified polyvinyl alcohol, polyurethane acrylate and antioxidant into a container, mix and stir evenly, and then place it in a vacuum oven at 95 - 105 °C for 20 - 40 min to obtain mixture A;

[0017] (2) At room temperature, add a foaming agent and a vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0018] (3) Feed mixture B into the hopper of a casting machine. After heating at 175 - 210 °C by the casting machine, a TPU molten mixture is obtained. Then, it is pushed by a rotating screw and extruded from the die head of the casting machine, and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. After pressing and cooling the TPU foamed film by a pressure roller, a lightweight anti-slip TPU foamed leather for a racket handle is obtained.

[0019] The preparation method of the lightweight anti-slip TPU foamed leather for a racket handle in the present invention has a simple process, easy operation control, is conducive to large-scale industrial production, the obtained TPU foamed leather has stable quality, has better softness, excellent wear resistance and dry and wet aging resistance, and also has the characteristics of good tensile strength, and still has a good static friction coefficient after absorbing water, with superior comprehensive performance.

[0020] The beneficial effects of the present invention are as follows: The lightweight anti-slip TPU foamed leather for a racket handle in the present invention has better softness, excellent wear resistance and dry and wet aging resistance, and also has the characteristics of good tensile strength, and still has a good static friction coefficient after absorbing water, that is, the TPU foam still has good friction performance after absorbing water, can well absorb the sweat on the hand of the athlete due to exercise, and still has a good anti-slip effect after absorbing water, providing the user with a good racket holding feeling and control force.

[0021] At the same time, the preparation method of the lightweight anti-slip TPU foamed leather for a racket handle has a simple process, easy operation control, is conducive to large-scale industrial production, the obtained lightweight anti-slip TPU foamed leather for a racket handle has stable quality, has better softness, excellent wear resistance and dry and wet aging resistance, and also has the characteristics of good tensile strength, and still has a good static friction coefficient after absorbing water, with superior comprehensive performance. Detailed Embodiments

[0022] For the convenience of understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments does not limit the present invention.

[0023] Embodiment 1

[0024] In this embodiment, the lightweight anti-slip TPU foamed leather for a racket handle includes a release paper and a TPU foamed film provided on the upper end surface of the release paper.

[0025] Further, the thickness of the TPU foamed film is 0.2 - 0.5 mm, and the density of the TPU foamed film is 0.28 - 0.3 g / cm 3 . Preferably, the thickness of the TPU foamed film is 0.4 mm, and the density of the TPU foamed film is 0.3 g / cm 3 .

[0026] Further, the TPU foamed film comprises the following raw materials in parts by weight: 80 parts of TPU particles, 22 parts of SEBS rubber, 18 parts of polyolefin elastomer, 15 parts of silica-modified polyvinyl alcohol, 12 parts of polyurethane acrylate, 1 part of foaming agent, 1 part of vulcanizing agent, and 1 part of antioxidant.

[0027] In this embodiment, the antioxidant is 2-mercaptobenzimidazole. The vulcanizing agent is dicumyl peroxide. The foaming agent is bicarbonate.

[0028] In this embodiment, the TPU particles are TPU of model A88H4622 from Huntsman Corporation. The polyurethane acrylate is polyurethane acrylate PU610. The polyolefin elastomer is POE8180 from Dow Chemical Company, USA.

[0029] Further, the preparation method of each part of the silica-modified polyvinyl alcohol comprises the following steps:

[0030] (S1) Dissolve PVA powder in deionized water, and magnetically stir in a 96°C water bath for 3.5 h until the PVA powder is completely dissolved to obtain a 10% by mass PVA aqueous solution;

[0031] (S2) Add silica sol and silica powder to the PVA aqueous solution, stir for 60 min, then place in a 45°C drying oven until constant weight, and finally grind into powder to obtain silica-modified polyvinyl alcohol.

[0032] In this embodiment, the PVA powder is PVA1799 powder.

[0033] The preparation method of the lightweight anti-slip TPU foamed leather for the racket handle comprises the following steps:

[0034] (1) According to the parts by weight, pour TPU particles, SEBS rubber, polyolefin elastomer, silica-modified polyvinyl alcohol, polyurethane acrylate, and antioxidant into a container, mix and stir evenly, and then place in a vacuum oven at 100°C for 30 min to obtain mixture A;

[0035] (2) At room temperature, add the foaming agent and the vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0036] (3) Feed mixture B into the hopper of the casting machine. After heating at 200°C by the casting machine, a TPU molten mixture is obtained. Then, it is extruded from the die head of the casting machine by the rotation of the screw and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. After rolling and cooling the TPU foamed film by a pressure roller, a lightweight anti-slip TPU foamed leather for a racket handle is obtained.

[0037] Example 2

[0038] In this example, the TPU foamed film comprises the following raw materials in parts by weight: 100 parts of TPU particles, 27 parts of SEBS rubber, 23 parts of polyolefin elastomer, 19 parts of silica-modified polyvinyl alcohol, 15 parts of polyurethane acrylate, 2 parts of foaming agent, 1.5 parts of vulcanizing agent and 1.5 parts of antioxidant.

[0039] Furthermore, a method for preparing the lightweight anti-slip TPU foamed leather for a racket handle comprises the following steps:

[0040] (1) According to the parts by weight, pour the TPU particles, SEBS rubber, polyolefin elastomer, silica-modified polyvinyl alcohol, polyurethane acrylate and antioxidant into a container, mix and stir evenly, and then place it in a vacuum oven at 100°C for 30 min to obtain mixture A;

[0041] (2) At room temperature, add the foaming agent and vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0042] (3) Feed mixture B into the hopper of the casting machine. After heating at 200°C by the casting machine, a TPU molten mixture is obtained. Then, it is extruded from the die head of the casting machine by the rotation of the screw and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. After rolling and cooling the TPU foamed film by a pressure roller, a lightweight anti-slip TPU foamed leather for a racket handle is obtained.

[0043] The remaining content of this example is the same as that of Example 1.

[0044] Example 3

[0045] In this example, the TPU foamed film comprises the following raw materials in parts by weight: 120 parts of TPU particles, 32 parts of SEBS rubber, 28 parts of polyolefin elastomer, 23 parts of silica-modified polyvinyl alcohol, 18 parts of polyurethane acrylate, 3 parts of foaming agent, 2 parts of vulcanizing agent and 2 parts of antioxidant.

[0046] Furthermore, a method for preparing the lightweight anti-slip TPU foamed leather for a racket handle comprises the following steps:

[0047] (1) By weight parts, pour TPU particles, SEBS rubber, polyolefin elastomer, silica-modified polyvinyl alcohol, polyurethane acrylate and antioxidant into a container, mix and stir evenly, and then place it in a vacuum oven at 100 °C for 30 min to obtain mixture A;

[0048] (2) At room temperature, add a foaming agent and a vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0049] (3) Feed mixture B into the hopper of a casting machine. After heating at 200 °C by the casting machine, a TPU molten mixture is obtained. Then, it is pushed by a rotating screw and extruded from the die head of the casting machine, and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. After pressing and cooling the TPU foamed film by a pressure roller, a lightweight anti-slip TPU foamed leather for a racket handle is obtained.

[0050] The remaining content of this example is the same as that of Example 1.

[0051] Comparative Example 1

[0052] The difference between this comparative example and Example 2 is that an equal amount of TPU particles is used to replace SEBS rubber, and an equal amount of TPU particles is used to replace polyolefin elastomer.

[0053] That is, in this comparative example, the TPU foamed film comprises the following raw materials in weight parts: 150 parts of TPU particles, 19 parts of silica-modified polyvinyl alcohol, 15 parts of polyurethane acrylate, 2 parts of foaming agent, 1.5 parts of vulcanizing agent and 1.5 parts of antioxidant.

[0054] Furthermore, a method for preparing a lightweight anti-slip TPU foamed leather for a racket handle comprises the following steps:

[0055] (1) By weight parts, pour TPU particles, silica-modified polyvinyl alcohol, polyurethane acrylate and antioxidant into a container, mix and stir evenly, and then place it in a vacuum oven at 100 °C for 30 min to obtain mixture A;

[0056] (2) At room temperature, add a foaming agent and a vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0057] (3) Feed mixture B into the hopper of a casting machine. After heating at 200 °C by the casting machine, a TPU molten mixture is obtained. Then, it is pushed by a rotating screw and extruded from the die head of the casting machine, and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. After pressing and cooling the TPU foamed film by a pressure roller, a lightweight anti-slip TPU foamed leather for a racket handle is obtained.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 3 is that an equal amount of polyvinyl alcohol is used to replace silica for modifying polyvinyl alcohol. That is, in this comparative example, the TPU foamed film comprises the following raw materials in parts by weight: 120 parts of TPU particles, 32 parts of SEBS rubber, 28 parts of polyolefin elastomer, 23 parts of polyvinyl alcohol, 18 parts of polyurethane acrylate, 3 parts of foaming agent, 2 parts of vulcanizing agent, and 2 parts of antioxidant.

[0060] Furthermore, a preparation method of a lightweight anti-slip TPU foamed leather for a racket handle comprises the following steps:

[0061] (1) According to the parts by weight, pour TPU particles, SEBS rubber, polyolefin elastomer, polyvinyl alcohol, polyurethane acrylate and antioxidant into a container, mix and stir evenly, and then place them in a vacuum oven at 100 °C for 30 min to obtain mixture A;

[0062] (2) At room temperature, add the foaming agent and vulcanizing agent to mixture A and stir evenly to obtain mixture B;

[0063] (3) Feed mixture B into the hopper of a casting machine. After heating at 200 °C by the casting machine, a TPU molten mixture is obtained. Then, it is pushed by a rotating screw and extruded from the die head of the casting machine, and cast onto the upper end of the release paper, so that a TPU foamed film is attached to the release paper. The TPU foamed film is rolled and cooled by a pressure roller to obtain the lightweight anti-slip TPU foamed leather for a racket handle.

[0064] Performance detection test

[0065] Perform performance tests on the lightweight anti-slip TPU foamed leather for racket handles prepared in Examples 1-3 and Comparative Examples 1-2. Test the Shore hardness, wear resistance, static friction coefficient after water absorption, dry and wet aging performance, and tensile strength of the lightweight anti-slip TPU foamed leather for racket handles. The test data are shown in Table 1 below:

[0066] Table 1

[0067]

[0068]

[0069] Among them, for hardness testing: select a Shore A hardness tester to test the hardness according to the national standard GB / T 531-2009.

[0070] Wear resistance: Test according to the provisions of "ISO4649 Determination of the wear resistance of vulcanized rubber or thermoplastic rubber".

[0071] Static friction coefficient test: The TPU foam films prepared in Examples 1-3 and Comparative Examples 1-2 were respectively cut into specimens of the same size. The static friction coefficients of the TPU foam films before and after water absorption were tested using a Qmesys friction coefficient tester (QM110CF). After making the stainless steel contact one side of the TPU foam film according to ASTM D1894, the static friction coefficient when sliding open was measured. Among them, for the water absorption treatment of the TPU foam film: at room temperature, the prepared TPU foam film was completely immersed in 500 mL of deionized water for 4 h, then placed in a wire basket for filtration until no water droplets dripped, and then the water on the surface of the TPU foam film was wiped off with absorbent paper to obtain the water-absorbed TPU foam film.

[0072] Wet and dry aging performance test: (1) The TPU foam films prepared in Examples 1-3 and Comparative Examples 1-2 were respectively cut into specimens of the same size, and their initial masses were recorded. (2) The specimens were placed in a damp heat test chamber with the temperature set at 60 °C and the humidity at 85% RH. (3) Under the set wet and dry cycling conditions, continuous damp heat exposure was carried out, and each cycle included 12 hours of damp heat exposure and 12 hours of drying. (4) The specimens were taken out for mass measurement every time after a cycle, and the wet and dry cycling was continuously carried out until the mass of the specimens decreased by 10%.

[0073] Tensile strength test: After cutting the TPU foam film prepared in the example or comparative example into test pieces according to the ASTM D638 Type V standard, a universal testing machine (model 4206-001) of INSTRON company was used to test at a tensile speed of 100 mm / min, and then the tensile strength (kgf / mm 2 = 9.8 Mpa) was measured through the software installed in the equipment.

[0074] The above embodiments are the preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious substitution without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A lightweight non-slip TPU foam leather for a racket handle, characterized by: It comprises a release paper and a TPU foam film arranged on the upper end surface of the release paper.

2. The lightweight non-slip TPU foam leather for a racket handle according to claim 1, characterized in that: The thickness of the TPU foam film is 0.2-0.5 mm.

3. The lightweight non-slip TPU foam leather for a racket handle according to claim 1, characterized in that: The density of the TPU foam film is 0.28-0.3 g / cm 3 .

4. The lightweight non-slip TPU foam leather for a racket handle according to claim 1, characterized in that: The TPU foam film comprises the following raw materials in parts by weight: 80-120 parts of TPU particles, 22-32 parts of SEBS rubber, 18-28 parts of polyolefin elastomer, 15-23 parts of silicon dioxide modified polyvinyl alcohol, 12-18 parts of polyurethane acrylate, 1-3 parts of foaming agent, 1-2 parts of vulcanizing agent and 1-2 parts of antioxidant.

5. The lightweight non-slip TPU foam leather for a racket handle according to claim 4, characterized in that: The preparation method of each portion of the silicon dioxide modified polyvinyl alcohol comprises the following steps: (S1) dissolving PVA powder in deionized water and magnetically stirring in a water bath at 96-97° C. for 3-4 hours until the PVA powder is completely dissolved, to obtain a PVA aqueous solution with a mass fraction of 9-11%; (S2) adding silica sol and silica powder to the PVA aqueous solution, stirring for 50-70 minutes, placing in a 40-50° C. drying oven until constant weight is reached, and finally grinding into powder to obtain silica-modified polyvinyl alcohol.

6. The lightweight non-slip TPU foam leather for a racket handle according to claim 5, characterized in that: The weight ratio of the PVA aqueous solution, silica sol and silica powder is 100:6-8:5-7.

7. The lightweight non-slip TPU foam leather for a racket handle according to claim 4, characterized in that: The antioxidant is 2-mercaptobenzimidazole.

8. The lightweight non-slip TPU foam leather for a racket handle according to claim 4, characterized in that: The vulcanizing agent is dicumyl peroxide.

9. The lightweight non-slip TPU foam leather for a racket handle according to claim 4, characterized in that: The foaming agent is bicarbonate.

10. A method for preparing the lightweight non-slip TPU foam leather for a racket handle according to any one of claims 1 to 9, characterized in that: The steps include: (1) Pour TPU particles, SEBS rubber, polyolefin elastomer, silica-modified polyvinyl alcohol, polyurethane acrylate and antioxidant into a container according to weight parts, mix and stir evenly, and then place in a vacuum oven at 95-105° C. for 20-40 minutes to obtain a mixture A; (2) at room temperature, adding a blowing agent and a vulcanizing agent to the mixture A and stirring evenly to obtain a mixture B; (3) The mixture B is fed into the hopper of a casting machine, and is heated at 175-210° C. by the casting machine to obtain a TPU molten mixture, which is then pushed by a rotating screw, extruded from the die head of the casting machine, and cast onto the upper end of the release paper, so that a TPU foam film is attached to the release paper. The TPU foam film is pressed and cooled by a pressure roller to obtain a lightweight non-slip TPU foam leather for a racket handle.

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