Anti-ultraviolet thermoplastic elastomer

Abstract

The invention relates to the technical field of thermoplastic elastomers, and discloses an uvioresistant thermoplastic elastomer, which is composed of the following raw materials by mass: 30-40% of a styrene-butadiene-styrene block copolymer (SBS); 20%-30% of a hydrogenated styrene-butadiene-styrene block copolymer (SEBS); 15%-25% of polypropylene (PP); 5%-10% of nano titanium dioxide (TiO2); 12%-4% of an ultraviolet light absorber UV-53; 0.5%-1.5% of an antioxidant 1010; and 10%-20% of plasticizer naphthenic oil. The nano titanium dioxide is subjected to surface modification, so that the dispersity of the nano titanium dioxide in the thermoplastic elastomer is improved, and the nano titanium dioxide can play an anti-ultraviolet role more uniformly. Meanwhile, a raw material formula and a preparation process are optimized, so that the mechanical property and the chemical resistance of the thermoplastic elastomer are enhanced on the basis of improving the ultraviolet resistance. And better interface bonding is formed between the nano titanium dioxide subjected to surface modification and other raw materials.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoplastic elastomers, and particularly relates to an anti-ultraviolet thermoplastic elastomer and a preparation method thereof. The thermoplastic elastomer is mainly applied to fields such as automotive interior parts and bathroom products. Background Art

[0002] In the automotive and bathroom industries, thermoplastic elastomers have been widely used due to their excellent elasticity, chemical resistance, easy processability and other characteristics. Automotive interior parts such as instrument panels and seat armrests, and bathroom products such as faucet handles and shower head gaskets all require thermoplastic elastomers to have good comprehensive performance. However, during the use of these products, they will be exposed to sunlight for a long time, and the ultraviolet radiation will cause the thermoplastic elastomer to age, resulting in problems such as discoloration, embrittlement, and decline in mechanical properties, seriously affecting the service life and appearance quality of the products.

[0003] At present, there are already some patented technologies for anti-ultraviolet of thermoplastic elastomers. For example, Patent No. 202411540752.7 discloses a preparation method of an anti-ultraviolet TPE thermoplastic elastomer material. This patent improves the anti-ultraviolet performance of the thermoplastic elastomer by adding traditional ultraviolet absorbers. However, this method has an obvious deficiency: the added traditional ultraviolet absorbers have poor dispersibility in the thermoplastic elastomer and are prone to agglomeration, resulting in unstable anti-ultraviolet effects. Moreover, during the high-temperature processing, the ultraviolet absorbers are prone to decomposition, further reducing their anti-ultraviolet performance.

[0004] With the continuous improvement of the requirements for product quality and service life in the automotive and bathroom industries, it has become particularly necessary to solve the problem of the decline in the performance of thermoplastic elastomers under ultraviolet radiation. Summary of the Invention

[0005] The purpose of the present invention is to provide an anti-ultraviolet thermoplastic elastomer to solve the above problems.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] An anti-ultraviolet thermoplastic elastomer is composed of the following raw materials in mass percentages:

[0008] Styrene-butadiene-styrene block copolymer (SBS) 30%-40%;

[0009] Hydrogenated styrene-butadiene-styrene block copolymer (SEBS) 20%-30%;

[0010] Polypropylene (PP) 15%-25%;

[0011] 5%-10% of nano-titanium dioxide (TiO2);

[0012] 2%-4% of ultraviolet absorber UV-531;

[0013] 0.5%-1.5% of antioxidant 1010;

[0014] 10%-20% of plasticizer naphthenic oil.

[0015] Preferably, the styrene-butadiene-styrene block copolymer (SBS) is of linear structure with a styrene content of 30 wt%, purchased from [Dongguan Shenghao Plastic Raw Materials Co., Ltd.]; the hydrogenated styrene-butadiene-styrene block copolymer (SEBS) has a hydrogenation degree greater than 95%, purchased from [Shanghai Baishu International Trade Co., Ltd.]; the melt flow rate of the polypropylene (PP) is 2-5 g / 10 min (230 °C, 2.16 kg), purchased from [Sinopec Maoming Petrochemical Company].

[0016] Preferably, the nano-titanium dioxide (TiO2) has a particle size of 5-10 nm, is anatase type, purchased from [Sichuan Juchun Materials Technology Co., Ltd.], and has been surface-modified. The surface modification method is as follows: Add nano-titanium dioxide to a 5% ethanol solution of silane coupling agent KH-570, ultrasonically disperse for 30 min, then stir and react at 80 °C for 2 h, and obtain surface-modified nano-titanium dioxide after filtration, washing, and drying.

[0017] Preferably, the purity of the ultraviolet absorber UV-531 is greater than 99%, purchased from [Changzhou Shanfeng Chemical Co., Ltd.]; the purity of the antioxidant 1010 is greater than 98%, purchased from [Lian An Long Bo Hua Pharmaceutical Chemistry Co., Ltd.]; the flash point of the plasticizer naphthenic oil is greater than 180 °C, purchased from [China National Offshore Oil Corporation Asphalt Co., Ltd.].

[0018] A preparation method of an anti-ultraviolet thermoplastic elastomer, comprising the following steps:

[0019] S1: Weigh each raw material according to the mass percentages described in Claim 1;

[0020] S2: Add the surface-modified nano-titanium dioxide, ultraviolet absorber UV-531, and antioxidant 1010 to the plasticizer naphthenic oil, and stir and mix in a high-speed mixer at a rotation speed of 1000-1500 r / min for 30-40 min to obtain an additive premix.

[0021] S3: Add styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS) and polypropylene (PP) into the hopper of a twin-screw extruder, and at the same time add the additive premix into the twin-screw extruder through a side feeding device; the temperature of the twin-screw extruder is set as follows: zone 1 is 160 - 170 °C, zone 2 is 170 - 180 °C, zone 3 is 180 - 190 °C, zone 4 is 190 - 200 °C, the screw speed is 300 - 400 r / min, and melt blend and extrude into pellets in the twin-screw extruder to obtain an anti-ultraviolet thermoplastic elastomer.

[0022] Preferably, when the high-speed mixer is stirring and mixing, the rotation speed is 1200 r / min and the stirring time is 35 min.

[0023] Preferably, the temperature of the twin-screw extruder is set as follows: zone 1 is 165 °C, zone 2 is 175 °C, zone 3 is 185 °C, zone 4 is 195 °C, and the screw speed is 350 r / min.

[0024] Preferably, the application of the anti-ultraviolet thermoplastic elastomer in the preparation of automotive interior parts or bathroom products.

[0025] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0026] 1. The innovation of the present invention lies in the surface modification of nano-titanium dioxide to improve its dispersibility in the thermoplastic elastomer, enabling it to play an anti-ultraviolet role more uniformly. At the same time, the raw material formula and preparation process are optimized, so that on the basis of the improved anti-ultraviolet performance of the thermoplastic elastomer, the mechanical properties and chemical resistance are also enhanced. The surface-modified nano-titanium dioxide forms a better interfacial bond with other raw materials, enhancing the internal structural stability of the thermoplastic elastomer, thereby improving the mechanical properties; while the optimized formula system improves the tolerance of the thermoplastic elastomer to chemical substances, solving the problem of performance degradation caused by possible contact with chemical substances during the use of automotive and bathroom products. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0028] Embodiment 1

[0029] Preparation of surface-modified nano-titanium dioxide: The nano-titanium dioxide was added to a 5% by mass silane coupling agent KH-570 ethanol solution, ultrasonically dispersed for 30 min, and then stirred and reacted at 80 °C for 2 h. After filtration, washing, and drying, it was reserved for use.

[0030] Weigh the raw materials according to the following mass percentages:

[0031] Raw materials Mass percentage Styrene-butadiene-styrene block copolymer (SBS) 35％ Hydrogenated styrene-butadiene-styrene block copolymer (SEBS) 25％ Polypropylene (PP) 20％ <![CDATA[Surface-modified nano-titanium dioxide (TiO2)]]> 8％ UV absorber UV-531 3％ Antioxidant 1010 1％ Plasticizer naphthenic oil 18％

[0032] The surface-modified nano-titanium dioxide, ultraviolet absorber UV-531, and antioxidant 1010 were added to the plasticizer naphthenic oil and stirred and mixed at a speed of 1200 r / min in a high-speed mixer for 35 min to obtain an additive premix.

[0033] The styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), and polypropylene (PP) were added to the hopper of a twin-screw extruder. At the same time, the additive premix was added to the twin-screw extruder through a side feeding device. The temperature of the twin-screw extruder was set as follows: zone 1 at 165 °C, zone 2 at 175 °C, zone 3 at 185 °C, zone 4 at 195 °C, the screw speed was 350 r / min, and melt blending and extrusion granulation were carried out to obtain a thermoplastic elastomer sample 1.

[0034] Example 2

[0035] Prepare the surface-modified nano-titanium dioxide in the same way as in Example 1.

[0036] Adjust the mass percentages of the raw materials as follows:

[0037] Raw materials Mass percentage Styrene-butadiene-styrene block copolymer (SBS) 30％ Hydrogenated styrene-butadiene-styrene block copolymer (SEBS) 30％ Polypropylene (PP) 15％ <![CDATA[Surface-modified nano-titanium dioxide (TiO2)]]> 10％ UV absorber UV-531 4％ Antioxidant 1010 1.5％ Plasticizer naphthenic oil 9.5％

[0038] Perform the same steps 3 and 4 as in Example 1 to obtain a thermoplastic elastomer sample 2.

[0039] Example 3

[0040] Prepare the surface-modified nano-titanium dioxide in the same way as in Example 1.

[0041] Adjust the mass percentages of the raw materials as follows:

[0042]

[0043]

[0044] Perform the same steps 3 and 4 as in Example 1 to obtain a thermoplastic elastomer sample 3.

[0045] Comparative Example 1

[0046] The nano-titanium dioxide was not surface-modified, and the unmodified nano-titanium dioxide was directly used.

[0047] Operate according to the raw material mass percentages and preparation steps of Example 1 to obtain the thermoplastic elastomer sample 4.

[0048] Comparative Example 2

[0049] Without adding the ultraviolet absorber UV-531, with other raw materials and preparation steps the same as in Example 1, obtain the thermoplastic elastomer sample 5.

[0050] Performance testing

[0051] Ultraviolet resistance performance testing: Use an ultraviolet aging test chamber to test each sample, simulate the ultraviolet irradiation environment, with the irradiation intensity of 550 W / m 2 , and the irradiation time of 1000 h. Use a color difference meter to measure the color change (ΔE) of the sample before and after the test. The smaller the color change, the better the ultraviolet resistance performance.

[0052] Mechanical property testing: Use a universal material testing machine to test the tensile strength and elongation at break of the sample according to the standard of GB / T 1040.2-2006.

[0053] Chemical resistance testing: Immerse the sample in a 10% hydrochloric acid solution for 72 h, take it out and observe whether there are phenomena such as swelling, color change, cracking, etc. on the surface of the sample, and test the tensile strength retention rate of the sample before and after immersion.

[0054] The performance test results are shown in the following table:

[0055]

[0056]

[0057] It can be seen from the test results that the color changes of Examples 1-3 are significantly smaller than those of Comparative Example 1 and Comparative Example 2, indicating that the surface-modified nano-titanium dioxide and the method of adding an ultraviolet absorber of the present invention effectively improve the ultraviolet resistance performance of the thermoplastic elastomer. In Comparative Example 1, the unmodified nano-titanium dioxide has poor dispersibility, resulting in poor ultraviolet resistance effect; in Comparative Example 2, no ultraviolet absorber is added, and the ultraviolet resistance performance drops significantly.

[0058] In terms of mechanical properties, the tensile strength and elongation at break of Examples 1-3 are better than those of Comparative Example 1 and Comparative Example 2, which shows that the surface-modified nano-titanium dioxide enhances the internal structural stability of the thermoplastic elastomer and improves the mechanical properties.

[0059] In the chemical resistance test, the tensile strength retention rates of Examples 1-3 after immersion in hydrochloric acid are relatively high, while those of Comparative Example 1 and Comparative Example 2 are relatively low, proving that the optimized formulation system of the present invention improves the chemical resistance of the thermoplastic elastomer.

[0060] In summary, through surface modification of nano-titanium dioxide, optimization of the raw material formula and preparation process, the present invention successfully prepares a thermoplastic elastomer with excellent ultraviolet resistance, mechanical properties and chemical resistance, effectively solving the problems existing in the prior art and having prominent substantive features and remarkable progress.

[0061] The above description of the embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermoplastic elastomer resistant to ultraviolet rays, characterized in that, Composed of raw materials with the following mass percentages:

2. The thermoplastic elastomer with ultraviolet resistance according to claim 1, characterized in that The styrene-butadiene-styrene block copolymer (SBS) has a linear structure, with a styrene content of 30 wt%, and is purchased from [Dongguan Shenghao Plastic Raw Materials Co., Ltd.]; the hydrogenated styrene-butadiene-styrene block copolymer (SEBS) has a hydrogenation degree greater than 95%, and is purchased from [Shanghai Baishu International Trade Co., Ltd.]; the polypropylene (PP) has a melt flow rate of 2 - 5 g / 10 min (230 °C, 2.16 kg), and is purchased from [Sinopec Maoming Petrochemical Company].

3. A thermoplastic elastomer with anti-ultraviolet properties according to claim 1, characterized in that, The nano-titanium dioxide (TiO₂) has a particle size of 5 - 10 nm, is anatase type, and is purchased from [Sichuan Juchun Material Technology Co., Ltd.], and has been surface-modified. The surface modification method is as follows: Add nano-titanium dioxide to a 5% ethanol solution of silane coupling agent KH-570, ultrasonically disperse for 30 min, then stir and react at 80 °C for 2 h, filter, wash, and dry to obtain surface-modified nano-titanium dioxide.

4. An anti-ultraviolet thermoplastic elastomer according to claim 1, characterized in that, The ultraviolet absorber UV-531 has a purity greater than 99%, and is purchased from [Changzhou Shanfeng Chemical Co., Ltd.]; the antioxidant 1010 has a purity greater than 98%, and is purchased from [Li An Long Bo Hua Pharmaceutical Chemistry Co., Ltd.]; the plasticizer naphthenic oil has a flash point greater than 180 °C, and is purchased from [Zhonghai Asphalt Co., Ltd.].

5. The preparation method of a thermoplastic elastomer with ultraviolet resistance according to any one of claims 1-4, characterized in that, Including the following steps: S1: Weigh each raw material according to the mass percentages described in Claim 1. S2: Add the surface-modified nano-titanium dioxide, ultraviolet absorber UV-531, and antioxidant 1010 to the plasticizer naphthenic oil, and stir and mix in a high-speed mixer at a rotation speed of 1000 - 1500 r / min for 30 - 40 min to obtain an additive premix. S3: Add the styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), and polypropylene (PP) to the hopper of a twin-screw extruder, and at the same time add the additive premix to the twin-screw extruder through a side feeding device; the temperature of the twin-screw extruder is set as follows: zone 1: 160 - 170 °C, zone 2: 170 - 180 °C, zone 3: 180 - 190 °C, zone 4: 190 - 200 °C, the screw rotation speed is 300 - 400 r / min, and melt blend and extrude pellets in the twin-screw extruder to obtain an anti-ultraviolet thermoplastic elastomer.

6. The preparation method of a thermoplastic elastomer with ultraviolet resistance according to claim 5, characterized in that, When the high-speed mixer stirs and mixes, the rotation speed is 1200 r / min, and the stirring time is 35 min.

7. The preparation method of an anti-ultraviolet thermoplastic elastomer according to claim 5, characterized in that, The temperature of the twin-screw extruder is set as follows: zone 1: 165 °C, zone 2: 175 °C, zone 3: 185 °C, zone 4: 195 °C, and the screw rotation speed is 350 r / min.

8. The application of the anti-ultraviolet thermoplastic elastomer according to any one of Claims 1 - 4 in the preparation of automotive interior parts or bathroom products.

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