Modified tpu material with low polarity stain bleeding and preparation method thereof

Abstract

The application relates to the field of TPU materials, and discloses a modified TPU material with low precipitation and resistance to polarity dirt and a preparation method thereof. The modified TPU material with low precipitation and resistance to polarity dirt is prepared from the following raw materials in percentage by weight: TPU 40-60%, SEBS 8-18%, plasticizer 10-15%, compatibilizer 8-15%, anti-dirt agent 8-15%, polarity adjusting agent 5-10% and antioxidant 0.1-0.5%; the anti-dirt agent is composed of acrylic modified silicone and ultrahigh molecular polyethylene with a molecular weight of 5-7 million; the preparation method is as follows: SEBS, the plasticizer and the polarity adjusting agent are mixed and left to stand; the compatibilizer and the anti-dirt agent are added, and melt extrusion and granulation are carried out; TPU and the antioxidant are added, mixed, melt extruded, cooled and granulated. The prepared modified TPU material has good mechanical properties, resistance to polarity dirt and low precipitation, and is suitable for 3C electronic products such as soft coating layers of data line outer sheaths, mouse keyboards and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of TPU materials, more particularly, it relates to a modified TPU material with low polarity stain resistance and low outgassing and a preparation method thereof. BACKGROUND

[0002] TPU material is a kind of thermoplastic elastomer material, which has excellent wear resistance, elasticity, flexibility, low temperature resistance and oil resistance, good environmental protection, and is easy to process and shape, and is widely used in 3C electronic products, such as data line outer cover, soft coating layer of mouse and keyboard, etc. The oil resistance of TPU material mainly shows the stain resistance to some substances containing non-polar components, such as olive oil, peanut oil, skin cream, water-based pen, etc., which is not easy to remain after contact. However, for some substances containing polar components, such as lipstick, oily pen, mustard, ketchup, etc., it is very easy to color after contact, and it is difficult to clean, which affects the appearance.

[0003] In the prior art, in order to improve the oil resistance of TPU material, some lubricating aids are added, such as polyethylene wax, silicone powder, pentaerythritol stearate, stearic acid, stearic acid amide, calcium stearate, etc., so that the surface of TPU material is treated to be more smooth, so that the surface of TPU material is more resistant to stains.

[0004] However, it is found in actual application that the non-polar stain resistance of these lubricating aids is not obvious, and the stains containing polar components are still easy to penetrate to the surface of TPU material, so that the product is contaminated and cannot be cleaned; and these lubricating aids are easy to appear sticky after being used for a period of time, which is more easy to stain, and hand sticking problem occurs, further reducing the stain resistance and use comfort of the product. SUMMARY

[0005] In order to solve the problems of low non-polar stain resistance of existing TPU material and easy to stick on the surface after long-term use, the present application provides a modified TPU material with low non-polar stain resistance and low outgassing and a preparation method thereof.

[0006] In the first aspect, the present application provides a modified TPU material with low non-polar stain resistance and low outgassing, which adopts the following technical scheme:

[0007] A modified TPU material with low non-polar stain resistance and low outgassing is prepared from the following raw materials by weight percentage: TPU 40-60%

[0008] SEBS 8-18%

[0009] Plasticizer 10-15%

[0010] Compatibility agent 8-15%

[0011] Anti-fouling agent 8-15%

[0012] Polarity adjuster 5-10%

[0013] Antioxidant 0.1-0.5%;

[0014] The antifouling agent is composed of acrylic-modified silicone and ultra-high molecular weight polyethylene; the ultra-high molecular weight polyethylene has a molecular weight of 5-7 million.

[0015] By adopting the above technical solution, a modified TPU material with good flexibility, resistance to polar dirt and low exudation performance is prepared. It is suitable for 3C electronic products, such as the outer sheath of data cables, soft overlays for mice and keyboards, etc. It is not easy to become sticky after long-term use, has good smoothness, and is not easily damaged.

[0016] TPU (Thermoplastic Polyurethane) is a block linear polymer composed of soft and hard segments. The soft segments are typically polyester or polyether, providing elasticity and flexibility. The hard segments, composed of diisocyanates and chain extenders, provide strength and heat resistance. Polar groups such as ester groups, ether bonds, and isocyanate groups create strong intermolecular forces in TPU, such as hydrogen bonds and van der Waals forces, giving it polar properties. Based on the principle of "like dissolves like," some alcohols or esters containing polar groups have strong permeability and adhesion to TPU surfaces, resulting in poor resistance to polar contamination. Contact with these substances makes TPU easily contaminated, leading to surface staining and difficulty in cleaning.

[0017] Therefore, this application modifies TPU materials by compounding SEBS, plasticizers, compatibilizers, antifouling agents, polarity modifiers, and antioxidants. The compounding of SEBS and polarity modifiers reduces the polarity of the modified TPU material while improving its strength and processing performance, giving it excellent flexibility and resistance to polar staining. The compatibilizer improves the compatibility and dispersion uniformity of the components in the system, resulting in a uniformly dispersed and dense structure, further enhancing the flexibility and resistance to polar oil stains of the modified TPU material and reducing the problem of precipitation during use. The antifouling agent consists of acrylic-modified silicone and ultra-high molecular weight polyethylene with a molecular weight of 5-7 million. Silicone reduces frictional resistance and improves wear resistance through the flexibility and lubrication properties of silicone resin. Simultaneously, the compatibility of the acrylic structure with ultra-high molecular weight polyethylene (UHMWPE) allows for mutual compatibility and interwoven dispersion, exhibiting a good synergistic effect. This further forms a dense, interwoven dispersion system, reducing the surface polarity of the modified TPU material and improving its self-lubricating and slip properties. It also enhances the compatibility of the components in the system, further synergizing with SEBS, compatibilizers, and polarity modifiers to further improve the flexibility, resistance to polar fouling, and low exudation performance of the modified TPU material. Plasticizers improve the processing stability and flowability of the components in the system, allowing for thorough oil filling and mixing. Antioxidants improve the aging resistance of the modified TPU material, reducing the problem of yellowing upon heating and extending its service life. The modified TPU material obtained in this application solves the problem of poor resistance to polar fouling in TPU materials by traditional lubricants and effectively improves the surface stickiness of TPU materials during long-term use.

[0018] Preferably, the antifouling agent is composed of acrylic-modified silicone and ultra-high molecular weight polyethylene in a weight ratio of 1:(0.8-1.5).

[0019] By adopting the above technical solutions and optimizing the proportion of antifouling agents, the dispersion and density of acrylic modified silicone and ultra-high molecular weight polyethylene in the system are further improved, so that the modified TPU material has good anti-polar dirt resistance as well as good low exudation performance and flexibility.

[0020] Preferably, the styrene content of the SEBS is 31-34 wt%.

[0021] By adopting the above technical solutions, SEBS with a higher styrene content can impart excellent toughness and wear resistance to modified TPU materials while reducing the polarity of the materials, further improving compatibility and processing performance with the system, and enhancing the stability and resistance to polar oil stains of modified TPU materials.

[0022] Preferably, the compatibilizer is composed of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer in a weight ratio of 1:(1-2).

[0023] By employing the above technical solution, maleic anhydride-grafted SEBS, due to the active maleic anhydride groups on its molecular chain, can interact with other molecular chain segments, improving the system's compatibility. The PU-hydrogenated styrene block copolymer comprises polyurethane and hydrogenated styrene segments. The polyurethane segment provides good elasticity, while the hydrogenated styrene segment provides rigidity, non-polar properties, and stability. The synergistic effect of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer allows for better dispersion and bonding of the components in the modified TPU material, reducing phase separation and forming a more stable, dense structure. This improves the stability and compatibility of the modified TPU material, reduces surface polarity, and thus improves resistance to polar fouling and enhances low-exudation properties. Simultaneously, it also improves the flexibility of the modified TPU material.

[0024] Preferably, the polarity modifier is atactic polypropylene, and the molecular weight of atactic polypropylene is 80,000-150,000.

[0025] By adopting the above technical solution, atactic polypropylene can be used as a polarity modifier to effectively reduce the polarity of the material and enhance its resistance to polar fouling. Optimizing the molecular weight to 80,000-150,000 allows atactic polypropylene to have better dispersibility and compatibility in the system, further improving the performance stability of the modified TPU material and giving it good resistance to polar fouling and low exudation characteristics.

[0026] Preferably, the plasticizer is one or a combination of white oil 150N, white oil 500N, and paraffin oil 2280.

[0027] By adopting the above technical solution, selecting one or a combination of white oil 150N, white oil 500N, and paraffin oil 2280 as plasticizers can reduce the polarity of modified TPU materials, improve the fluidity of materials, and help materials to be better molded and uniformly dispersed during processing. At the same time, these plasticizers, when combined with other raw materials, can enhance the resistance to polar contamination and low exudation performance of modified TPU materials.

[0028] Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 168.

[0029] By adopting the above technical solution, antioxidant 1010 and / or antioxidant 168 can be applied to the modified TPU material system, which can effectively improve the yellowing of modified TPU material when heated and improve the stability and appearance quality of modified TPU material during use.

[0030] Secondly, this application provides a method for preparing a modified TPU material with low precipitation and resistance to polar contamination, using the following technical solution:

[0031] A method for preparing a modified TPU material with low precipitation and resistance to polar contamination includes the following steps:

[0032] S1. Mix SEBS, plasticizer and polarity modifier by heating and stirring, then let stand to obtain mixture I;

[0033] S2. Add the compatibilizer and antifouling agent to mixture I and mix and stir to obtain mixture II;

[0034] S3. Melt extrusion of mixture II, cooling, pelletizing, and obtaining modified material;

[0035] S4. Mix and stir the modified material, TPU and antioxidant, melt extrude, cool, and pelletize to obtain a modified TPU material with low polar pollution resistance and low precipitation.

[0036] By adopting the above technical solution, SEBS, plasticizer, and polarity modifier are first heated and stirred, then allowed to stand to allow SEBS and polarity modifier to be fully oil-filled, softened, and evenly dispersed, resulting in mixture I. Then, compatibilizer and antifouling agent are added and mixed to further contact and fully disperse the components, resulting in a uniformly dispersed mixture II. Mixture II is then melt-extruded, cooled, and granulated to obtain a modified material with a uniform system. This modified material is then mixed with TPU and antioxidants, melt-melted, cooled, and granulated to obtain the modified TPU material. This preparation process, through the segmented addition and mixing, followed by melt molding with TPU and antioxidants, ensures that the modified TPU material forms a uniformly dispersed and densely structured system, improving the flexibility, resistance to polar oil stains, and low exudation performance of the obtained modified TPU material.

[0037] Preferably, the stirring temperature in steps S1 and S2 is 40-60℃, the stirring time is 5-10 min, and the settling time in step S1 is 18-24 h.

[0038] By adopting the above technical solution, the optimized stirring temperature and time help SEBS, plasticizer, polarity modifier, compatibilizer, and antifouling agent to be fully oiled and dispersed. The standing time in step S1 is set to 18-24 hours, which allows the components to further penetrate and disperse with each other, which is beneficial for the subsequent preparation of modified TPU materials with more stable performance.

[0039] Preferably, the melting temperature in step S3 is 210-230°C.

[0040] By adopting the above technical solution, the melting temperature in step S3 is controlled within the range of 210-230℃, which enables mixture II to melt fully, ensures uniform dispersion of each raw material, helps to form a stable homogeneous material, improves the quality and performance of the modified TPU material, and enhances its resistance to polar contamination and low precipitation effect.

[0041] Preferably, the melting temperature in step S4 is 185-200°C.

[0042] By adopting the above technical solution, setting the melting temperature in step S4 to 185-200℃ helps to fully melt and mix the modified material, TPU and antioxidant, ensuring that the components of the material are evenly distributed, thereby improving the performance stability of the modified TPU material; avoiding material decomposition or performance degradation due to excessively high temperature, and preventing the generation of volatile substances that cause low precipitation problems.

[0043] In summary, this application has the following beneficial effects:

[0044] 1. The modified TPU material with low polarity and low precipitation of this application is composed of TPU, SEBS, plasticizer, compatibilizer, antifouling agent, polarity modifier and antioxidant. The antifouling agent is composed of acrylic modified silicone and ultra-high molecular weight polyethylene with a molecular weight of 5-7 million. The modified TPU material with good flexibility, anti-polarity and low precipitation performance is prepared and is suitable for 3C electronic products, such as the outer sheath of data cables, soft rubber layer of mice and keyboards, etc. It is not easy to become sticky after long-term use, has good slip properties and is not easy to break.

[0045] 2. Using maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer in a better weight ratio as compatibilizers, and compounding random polypropylene with a molecular weight of 80,000-150,000 as a polarity modifier and SEBS with a styrene content of 31-34 wt%, the dispersion uniformity of each component in the modified TPU material is further improved, forming a more stable and dense structure, improving the stability and compatibility of the modified TPU material, improving the polarity of the system, and thus improving the resistance to polar fouling and the low exudation properties. At the same time, it can also improve the flexibility of the modified TPU material.

[0046] 3. The preparation process of this application involves the staged addition and mixing of SEBS, plasticizer, compatibilizer, antifouling agent and polarity modifier. First, the modified material is melted to form a modified material. Then, the modified material is melt-molded with TPU and antioxidant to obtain modified TPU material. This process can fully ensure that the modified TPU material forms a uniformly dispersed and dense system, thereby improving the flexibility, resistance to polar oil stains and low exudation performance of the obtained modified TPU material. Detailed Implementation

[0047] The present application will be further described in detail below with reference to the embodiments.

[0048] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used:

[0049] 1. TPU: Huntsman TPU 85AE;

[0050] 2. SEBS: Formosa Plastics 6151, styrene content 31-34wt%;

[0051] 3. Random polypropylene: Formosa Plastics 5090T, molecular weight 80,000-150,000;

[0052] 4. Maleic anhydride grafted SEBS: Kerté 1901;

[0053] 5. PU-hydrogenated styrene block copolymer: Kuraray TU-S5265;

[0054] 6. Acrylic-modified silicone: Shin-Etsu R170S;

[0055] 7. Ultra-high molecular weight polyethylene: Korean YOCHIC UHMWPE U050, molecular weight 5 million; Korean YOCHIC UHMWPE U070, molecular weight 7 million;

[0056] 8. Maleic anhydride grafted TPU: Shenghao Plastics, TPU-G-MAH;

[0057] 9. Styrene grafted with maleic anhydride: Clayville, 2000-P.

[0058] Example

[0059] Example 1

[0060] Example 1 discloses a modified TPU material with low polar fouling resistance and low precipitation, which is prepared by the following steps:

[0061] S1. Mix 1.8 kg SEBS, 1 kg white oil 150N as plasticizer and 0.57 kg atactic polypropylene as polarity modifier, stir for 10 min at 40℃, and then let stand at room temperature for 24 h to obtain mixture I.

[0062] S2. Add 1.1 kg of compatibilizer (composed of maleic anhydride grafted SEBS and styrene grafted maleic anhydride in a weight ratio of 1:2) and 1.5 kg of antifouling agent (composed of acrylic modified silicone and ultra-high molecular weight polyethylene in a weight ratio of 1:0.4, the ultra-high molecular weight polyethylene is model U050 and the molecular weight is 5 million) to mixture I and mix. Stir at 40℃ for 10 min to obtain mixture II.

[0063] S3. Mixture II is melt-extruded using a twin-screw extruder. The melt temperature is set as follows: Zone 1 210℃, Zone 2 215℃, Zone 3 225℃, Zone 4 230℃, Zone 5 220℃, Zone 6 210℃. The screw speed is 200 r / min. The mixture is cooled with water and pelletized to obtain the modified material.

[0064] S4. Mix the modified material, 4 kg TPU and 0.03 kg antioxidant 168, stir at 40℃ for 10 min, then add to a twin-screw extruder for melt extrusion. Set the melt temperature as follows: Zone 1 185℃, Zone 2 190℃, Zone 3 195℃, Zone 4 200℃, Zone 5 190℃, Zone 6 185℃, screw speed 300 r / min, water cooling, pelletizing, to obtain a modified TPU material with low polar contamination resistance and low precipitation.

[0065] Example 2-3

[0066] The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation parameters, as detailed in Table 1 below.

[0067] Table 1. Raw material usage and preparation parameters for Examples 1-3

[0068]

[0069]

[0070]

[0071] Example 4

[0072] The difference between Example 4 and Example 1 is that the weight ratio of acrylic-modified silicone to ultra-high molecular weight polyethylene is 1:0.8, while the rest is the same as in Example 1.

[0073] Example 5

[0074] The difference between Example 5 and Example 1 is that the weight ratio of acrylic-modified silicone and ultra-high molecular weight polyethylene is 1:1.5, while the rest is the same as in Example 1.

[0075] Example 6

[0076] The difference between Example 6 and Example 4 is that the compatibilizer is composed of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer in a weight ratio of 1:2, while the rest is the same as in Example 4.

[0077] Example 7

[0078] The difference between Example 7 and Example 6 is that the compatibilizer is composed of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer in a weight ratio of 1:1, while the rest is the same as in Example 4.

[0079] Example 8

[0080] The difference between Example 8 and Example 1 lies in the preparation method. In Example 8, 4 kg TPU, 1.8 kg SEBS, and 1 kg white oil 150N are used as plasticizers, 0.57 kg atactic polypropylene is used as a polarity modifier, 1.1 kg compatibilizer (composed of maleic anhydride-grafted SEBS and maleic anhydride-grafted TPU in a weight ratio of 1:2), and 1.5 kg antifouling agent (composed of acrylic acid-modified silicone and ultra-high molecular weight polyethylene in a weight ratio of 1:0.4). Polyethylene (model U050, molecular weight 5 million) and 0.03 kg of antioxidant 168 were mixed and stirred at 40℃ for 10 min. Then, the mixture was added to a twin-screw extruder for melt extrusion. The melt temperatures were set as follows: Zone 1 185℃, Zone 2 190℃, Zone 3 195℃, Zone 4 200℃, Zone 5 190℃, Zone 6 185℃. The screw speed was 300 r / min. The mixture was water-cooled and pelletized to obtain a modified TPU material with low polar contamination and low precipitation.

[0081] Comparative Example

[0082] Comparative Example 1

[0083] The difference between Comparative Example 1 and Example 1 is that the acrylic modified silicone was replaced with silicone masterbatch, which was Dow Corning MB50-001. Otherwise, it was the same as Example 1.

[0084] Comparative Example 2

[0085] The difference between Comparative Example 2 and Example 1 is that the acrylic modified silicone was replaced with silicone powder, which was CS-001 silicone powder from Foshan Jiuruixing Materials. Otherwise, it was the same as Example 1.

[0086] Comparative Example 3

[0087] The difference between Comparative Example 3 and Example 1 is that the acrylic modified silicone was replaced with polyethylene wax, which was SCGC Chemical (Thailand) LPO400F. Otherwise, it was the same as Example 1.

[0088] Comparative Example 4

[0089] The difference between Comparative Example 4 and Example 1 is that the same mass of ultra-high molecular weight polyethylene was replaced with high molecular weight polyethylene with a molecular weight of 500,000, while the rest was the same as Example 1.

[0090] Comparative Example 5

[0091] The difference between Comparative Example 5 and Example 1 is that the acrylic-modified silicone was replaced with ultra-high molecular weight polyethylene, while the rest is the same as Example 1.

[0092] Comparative Example 6

[0093] The difference between Comparative Example 6 and Example 1 is that random polypropylene was replaced with SEBS, while the rest is the same as Example 1.

[0094] Performance testing

[0095] The following performance tests were conducted on the modified TPU materials with low polar dirt release obtained in Examples 1-8 and Comparative Examples 1-6: The modified TPU materials were melted (melting temperature was 200°C) and injection molded to prepare test samples of the required size.

[0096] 1. Tear strength test

[0097] Using the test method in ASTM-D624, and with a type C specimen, the tear strength (unit: kN / m) of the modified TPU material was tested, and the test results were recorded.

[0098] 2. Resistance to polar contamination test:

[0099] Using a contact angle tester, drop deionized water onto the surface of the test sample, measure the contact angle (unit: °), and record the test results.

[0100] 3. Smoothness test

[0101] According to the test method in ASTM D1894, the coefficient of dynamic friction of the test sample was tested and the test results were recorded.

[0102] 4. Precipitate test:

[0103] The test samples were placed in a constant temperature and humidity environment of 85℃ and 85% for 168 hours. The exudate levels on the surface of the test samples after the test were as follows: Grade A, no exudate; Grade B, slight exudate; Grade C, obvious exudate. The test results were recorded.

[0104] The following are the performance test data of the modified TPU materials with low polar fouling and low precipitation prepared in Examples 1-8 and Comparative Examples 1-6, as detailed in Table 2 below.

[0105] Table 2 Performance data of Examples 1-8 and Comparative Examples 1-6

[0106]

[0107] Based on Examples 1-3, Examples 4-5, and Comparative Examples 1-5, and in conjunction with Table 2, it can be concluded that using the acrylic-modified silicone and ultra-high molecular weight polyethylene (UHMWPE) with a molecular weight of 5-7 million as antifouling agents can significantly improve the flexibility, resistance to polar staining, smoothness, and low exudation of the prepared modified TPU material. Compared to Example 1, Examples 4-5 further optimized the amounts of acrylic-modified silicone and UHMWPE, resulting in improved tear strength, increased contact angle, and reduced dynamic friction coefficient in the prepared modified TPU material. In Comparative Examples 1-3, the type of acrylic-modified silicone was replaced, resulting in modified TPU materials with reduced tear strength of 5.3 kN / m, 6.9 kN / m, and 9.7 kN / m, respectively; reduced contact angle of 10.3°, 11.6°, and 12.1°, respectively; and increased dynamic friction coefficient of 0.232, 0.297, and 0.323, respectively. Furthermore, the exudate grade decreased from Grade A to Grade C after weathering tests. In Comparative Example 4, polyethylene with a molecular weight of 500,000 was used instead of ultra-high molecular weight polyethylene, resulting in modified TPU materials with reduced tear strength of 3.6 kN / m, reduced contact angle of 4.6°, and reduced dynamic friction coefficient of 0.12. Additionally, the exudate grade decreased from Grade A to Grade B after weathering tests. In Comparative Example 5, only ultra-high molecular weight polyethylene was added as an antifouling agent, resulting in a 7.5 kN / m reduction in tear strength, a 17° reduction in contact angle, a 0.426 reduction in dynamic friction coefficient, and a decrease in the exudate grade from Grade A to Grade C after weather resistance testing.

[0108] Combining Examples 4 and 6-7 with Table 2, it can be concluded that further optimization of the compatibilizer composition improves the flexibility, resistance to polar staining, smoothness, and low exudation of the modified TPU material. Examples 6-7 used a better weight ratio of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer as a compatibilizer, resulting in improved tear strength, increased contact angle, and reduced dynamic friction coefficient.

[0109] Based on Examples 1 and 8 and Table 2, it can be concluded that the modified TPU material prepared using the stepwise mixing and melting method of this application has better performance, possibly because the preparation method improves the dispersion uniformity and compatibility of the system.

[0110] Based on Example 1 and Comparative Example 6, and in conjunction with Table 2, it can be concluded that using the SEBS and atactic polypropylene of this application for compounding can effectively improve the flexibility, resistance to polar staining, smoothness, and low exudation of the prepared modified TPU material.

[0111] 5. Polarity dirt and contamination test

[0112] Heinz tomato sauce was prepared at 0.1 g / cm³. 2The coating amount was applied to the surface of the test sample, and the sample was placed at room temperature for 12 hours, and then placed in an environment with a temperature of 55°C and a humidity of 85% for 24 hours. After the test, the sample was wiped clean with anhydrous ethanol, and the color difference (ΔE) of the test sample before and after contamination was detected using a colorimeter. The detection results were detected and recorded.

[0113] The following are the polar fouling test data of the modified TPU materials with low polar fouling precipitation prepared in Examples 1-8 and Comparative Examples 1-6, as detailed in Table 3 below.

[0114] Table 3. Polar dirt contamination data for Examples 1-8 and Comparative Examples 1-6

[0115]

[0116]

[0117] Based on Examples 1-5 and Comparative Examples 1-5 and Table 3, it can be concluded that using the acrylic-modified silicone and ultra-high molecular weight polyethylene with a molecular weight of 5-7 million as anti-fouling agents can significantly improve the anti-polar dirt resistance of the prepared modified TPU material, and the color difference on the surface of the modified TPU material contaminated with tomato sauce is significantly reduced.

[0118] Based on Examples 4 and 6-7 and Table 3, it can be concluded that further optimization of the compatibilizer composition can further improve the anti-polar staining performance of the prepared modified TPU material, and reduce the color difference on the surface of the modified TPU material contaminated with tomato sauce.

[0119] In summary, the modified TPU material of this application exhibits excellent resistance to polar dirt.

[0120] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A modified TPU material with low polar fouling resistance and low precipitation, characterized in that, It is made from the following raw materials by weight percentage: TPU 40-60% SEBS 8-18% Plasticizer 10-15% Compatibilizer 8-15% Anti-fouling agent 8-15% Polarity adjuster 5-10% Antioxidant 0.1-0.5%; The antifouling agent is composed of acrylic-modified silicone and ultra-high molecular weight polyethylene in a weight ratio of 1:(0.8-1.5), wherein the ultra-high molecular weight polyethylene has a molecular weight of 5-7 million. The compatibilizer is composed of maleic anhydride-grafted SEBS and PU-hydrogenated styrene block copolymer in a weight ratio of 1:(1-2); The polarity modifier is atactic polypropylene, which has a molecular weight of 80,000-150,000.

2. The modified TPU material with low precipitation and resistance to polar contamination according to claim 1, characterized in that, The styrene content of the SEBS is 31-34 wt%.

3. The modified TPU material with low polar contamination resistance and low exudation according to claim 1, characterized in that, The plasticizer is one or a combination of white oil 150N, white oil 500N and paraffin oil 2280, and the antioxidant is antioxidant 1010 and / or antioxidant 168.

4. A method for preparing a modified TPU material with low precipitation and resistance to polar contamination as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix SEBS, plasticizer and polarity modifier by heating and stirring, then let stand to obtain mixture I; S2. Add the compatibilizer and antifouling agent to mixture I and mix and stir to obtain mixture II; S3. Melt extrusion of mixture II, cooling, pelletizing, and obtaining modified material; S4. Mix and stir the modified material, TPU and antioxidant, melt extrude, cool, and pelletize to obtain a modified TPU material with low polar pollution resistance and low precipitation.

5. The method for preparing a modified TPU material with low precipitation and resistance to polar contamination according to claim 4, characterized in that, The stirring temperature in steps S1 and S2 is 40-60℃, the stirring time is 5-10 min, and the settling time in step S1 is 18-24 h.

6. The method for preparing a modified TPU material with low precipitation and resistance to polar contamination according to claim 4, characterized in that, The melting temperature in step S3 is 210-230℃.

7. The method for preparing a modified TPU material with low precipitation and resistance to polar contamination according to claim 4, characterized in that, The melting temperature in step S4 is 185-200℃.

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