TPU particle, TPU film and preparation method and application thereof

Abstract

The invention discloses TPU particles, a TPU film and a preparation method and application of the TPU particles and the TPU film. The TPU particle provided by the invention comprises the following raw material components in parts by weight: 40-90 parts of polyether polyol; 60 to 100 parts of diisocyanate; 3-20 parts of a flame retardant; 2-10 parts of silicon dioxide; and 3-20 parts of a light stabilizer. The TPU film disclosed by the invention has excellent physical properties, realizes excellent wear resistance, flame retardance and yellowing resistance at the same time, is good in transparency, can meet the requirements of various application scenes, and is particularly suitable for floor films. The preparation method is simple, convenient and easy for large-scale production.

Description

Technical Field

[0001] This invention relates to TPU particles, TPU films, their preparation methods, and applications. Background Technology

[0002] Floor membranes, widely used in construction, home furnishings, and industry, primarily serve protective, moisture-proof, and decorative functions. Current technologies, particularly traditional floor membranes made from polymers such as PP, PVC, and PE, generally suffer from the following drawbacks: First, these products rely heavily on the inherent hardness of the substrate or simple coatings, making them susceptible to scratches and wear under frequent friction and loads, leading to a rapid loss of gloss and texture and a limited lifespan. Second, the aforementioned polymers themselves have poor flame-retardant properties, requiring the addition of large amounts of halogenated flame retardants. This often results in brittle materials, reduced processability, and potential environmental hazards, making it difficult to balance safety, mechanical properties, and environmental requirements. Third, the materials are prone to photo-oxidative aging under ultraviolet radiation and humid environments, leading to noticeable yellowing and color deterioration, severely impacting the durability and aesthetics of the decorative effect.

[0003] Current technologies for improving floor membranes mostly focus on enhancing a single performance characteristic, such as simply increasing hardness or adding certain additives. These measures often have mutual constraints: improving wear resistance may make the material too hard and lose its flexibility; improving flame retardancy and anti-yellowing properties may affect the processing technology and increase costs.

[0004] For example, Chinese patent CN120464071A discloses a method for preparing PP flooring film. PP flooring film has certain advantages in price, sufficient hardness, simple preparation process, and readily available raw materials. However, PP has average wear resistance and durability, slightly inferior feel, and a shorter service life. Chinese patent CN109354804A discloses a method for preparing PVC flooring film, which prepares a PVC flooring film with flame retardant and wear-resistant effects by mixing particles and additives, but its mechanical properties are poor.

[0005] Therefore, existing floor membrane technologies cannot simultaneously achieve properties such as wear resistance, flame retardancy, anti-yellowing, and mechanical properties. Developing floor membranes with excellent comprehensive performance remains an urgent technical problem to be solved. Summary of the Invention

[0006] The technical problem this invention aims to solve is to overcome the shortcomings of existing floor membranes in achieving a balance between wear resistance, flame retardancy, yellowing resistance, and mechanical properties. This invention provides TPU particles, a TPU film, its preparation method, and its applications. The TPU film possesses excellent physical properties, achieving superior wear resistance, flame retardancy, and yellowing resistance simultaneously, and also exhibits good transparency, meeting the needs of various application scenarios, particularly suitable for floor membranes. The preparation method of this invention is simple and easily scalable for mass production.

[0007] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0008] The present invention provides a TPU particle, which, by weight, comprises the following raw material components: 40-90 parts of polyether polyol, 60-100 parts of diisocyanate, 3-20 parts of flame retardant, 2-10 parts of silica, and 3-20 parts of light stabilizer.

[0009] In this invention, TPU refers to thermoplastic elastomer polyurethane.

[0010] In this invention, the polyether polyol can be 60-75 parts by weight, for example, 60 parts, 65 parts, 70 parts or 75 parts.

[0011] In this invention, the diisocyanate can be in the form of 80-100 parts by weight, for example, 80 parts, 85 parts, 90 parts, 95 parts or 100 parts.

[0012] In this invention, the flame retardant can be 3-15 parts by weight, for example, 3 parts, 5 parts, 7 parts, 9 parts or 15 parts.

[0013] In this invention, the silicon dioxide can be in the form of 4-8 parts by weight, for example, 4 parts, 6 parts or 8 parts.

[0014] In this invention, the light stabilizer can be 3-15 parts by weight, for example, 3 parts, 5 parts, 7 parts, 10 parts or 15 parts.

[0015] In this invention, the silicon dioxide generally refers to solid silicon dioxide material, such as powdered silicon dioxide, nano-silicon dioxide, or fumed silicon dioxide.

[0016] In this invention, the flame retardant may be a halogen-free flame retardant, preferably a phosphonate flame retardant, such as NP-PU07 or JY401.

[0017] The halogen-free flame retardant generally refers to conventional halogen-free flame retardants in the art.

[0018] In this invention, the light stabilizer is preferably one or more of UV-5411 ultraviolet absorber, UV-770 light stabilizer, and UV-3529 light stabilizer.

[0019] When the light stabilizer is a combination of UV-5411 ultraviolet absorber, UV-770 light stabilizer and UV-3529 light stabilizer, the mass ratio of UV-5411 ultraviolet absorber, UV-770 light stabilizer and UV-3529 light stabilizer can be 1:2:3.

[0020] In this invention, the raw material components of the TPU particles may also include a chain extender. The chain extender may be a small molecule compound conventionally used in the art to extend polymer chains in polyurethane synthesis reactions, preferably 1,4-butanediol.

[0021] The chain extender can be 20-50 parts by weight, preferably 30-45 parts, for example 30 parts, 35 parts, 40 parts or 45 parts.

[0022] Preferably, the raw material components of the TPU particles may further include one or more of antioxidants, lubricants, plasticizers, and dispersants.

[0023] The antioxidant is preferably antioxidant 1010.

[0024] The antioxidant may be present in 1-5 parts by weight, for example, 2 or 3 parts.

[0025] The lubricant improves the flowability and processing stability of TPU by reducing friction between the melt and the mold, thus making the TPU film forming more stable.

[0026] The lubricant is preferably zinc stearate and / or zinc stearate.

[0027] The lubricant may be 3-10 parts by weight, preferably 5-10 parts, for example 7 parts, 8 parts or 10 parts.

[0028] The plasticizer is preferably dioctyl phthalate.

[0029] The plasticizer may be 3-10 parts by weight, preferably 6-10 parts, for example 7 parts, 8 parts or 9 parts.

[0030] The dispersant is preferably stearic acid amine.

[0031] The dispersant may be 2-8 parts by weight, preferably 3-5 parts, for example 3 parts, 4 parts or 5 parts.

[0032] The present invention also provides a method for preparing TPU particles, which includes the following steps: mixing the raw material components of the above-mentioned TPU particles, granulating them, and obtaining TPU particles.

[0033] In this invention, the mixing temperature can be 170-210℃, for example 190℃.

[0034] In this invention, the mixing time can be 3-5 minutes, for example, 3 minutes.

[0035] In this invention, a cooling step may be included before pelleting, wherein cooling water is used for cooling; the temperature reached by cooling may be 5°C.

[0036] In this invention, the step of drying may be included after pelleting; the drying temperature may be 90-100℃, for example 100℃; the drying time may be 3-4h, for example 4h.

[0037] In this invention, the preparation method of the TPU particles can be carried out in a granulator according to conventional methods in the art. The granulator is preferably a twin-screw granulator.

[0038] The present invention also provides a TPU film, which is made from TPU particles as described above.

[0039] In this invention, the thickness of the TPU film can be 0.2-0.6 mm, for example 0.5 mm.

[0040] The present invention also provides a method for preparing a TPU film, which includes the following steps: melting and blending the aforementioned TPU particles, casting, and obtaining a TPU film.

[0041] In this invention, the temperature of the melt blending can be 170-210℃.

[0042] In this invention, the melt blending time can be 3-5 minutes, for example, 5 minutes.

[0043] In this invention, the TPU film can be prepared in a casting machine; the casting machine is preferably a single-screw casting machine.

[0044] The present invention also provides a composite flooring membrane, which includes a TPU film and a base film as described above.

[0045] In this invention, the base film can be an organic film commonly used in the art for preparing floor films, such as a PU film.

[0046] In this invention, the thickness ratio of the TPU film to the base film can be 1:(1-2), for example 1:1.6.

[0047] In this invention, the thickness of the PU film can be 0.3-1.2 mm, for example 0.8 mm.

[0048] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0049] The reagents and raw materials used in this invention are all commercially available.

[0050] The positive and progressive effects of this invention are as follows:

[0051] (1) The TPU film prepared using the TPU particles obtained by the present invention has excellent physical properties and achieves flame retardant and yellowing resistance. Through the iteration of multiple excellent properties, it meets the needs of various application scenarios and is particularly suitable for floor film.

[0052] (2) The TPU film of the present invention can simultaneously possess good wear resistance, flame retardancy and yellowing resistance, contains less flame retardant masterbatch, and can achieve a film flame retardancy rating of B2, and has good transparency.

[0053] (3) The preparation method of the present invention is simple and easy to scale up.

[0054] (4) The floor film prepared using the TPU film obtained by the present invention has flame retardant, wear resistant, anti-yellowing, anti-aging and corrosion resistant effects due to the protection of the TPU film layer. In actual use, it can improve the service life of the floor film and has good application prospects. Detailed Implementation

[0055] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0056] The types and manufacturers of the raw materials and materials used in the following embodiments and comparative examples are shown in Table 1 below:

[0057] Table 1. Types and sources of raw materials and ingredients used in each embodiment and comparative example.

[0058]

[0059] In the following examples and comparative examples, TPU particles and TPU films were prepared according to the raw material composition formulations in Table 2. The flame retardant used in Example 9 was JY401, while the flame retardant used in the other examples and comparative examples (excluding Example 9) was NP-PU07. The specific preparation methods are as follows:

[0060] 1. Preparation method of TPU particles:

[0061] The raw material components were thoroughly mixed at 190℃ using a twin-screw granulator for 3 minutes. After cooling to 5℃ with cooling water, the mixture was granulated. The resulting granules were then thoroughly dried in an oven at 100℃ for 4 hours to obtain TPU granules.

[0062] 2. Preparation method of TPU film:

[0063] The obtained TPU granules are added to a single-screw casting machine for melt blending (temperature range of 170-210℃, time of 5min), and then co-extruded and cast through a die to obtain a TPU film.

[0064] Table 2 Raw material composition formula

[0065]

[0066] Effect Example

[0067] Test subjects: TPU films prepared in each embodiment and comparative example.

[0068] Test method:

[0069] 1. The tear strength of the TPU film in Examples 1-10 and Comparative Examples 1-4, and the PVC film in Comparative Example 5 were tested. The specific test methods are as follows:

[0070] Cut right-angled specimens from the TPU and PVC films described above, with a length of approximately 114 mm, a width of approximately 12.7 mm, and a thickness of 0.5 mm. Using a standard universal tensile testing machine, fix the cut right-angled specimens in a tear fixture, ensuring that the right-angled cut is centered in the fixture and that the long side of the specimen is parallel to the direction of the tensile force. Start the tensile testing machine and apply a tensile force to the right-angled specimens at a specified speed (500 mm / min). The tensile testing machine records the force changes of the right-angled specimens in real time and generates a force-displacement curve. The test conditions are 23±2℃ and 50%±5% relative humidity.

[0071] The maximum force during the tearing process of a right-angled specimen is calculated using the following formula and denoted as the tear strength (unit: kN / m).

[0072] F=F / t

[0073] Where F is the maximum force during the tearing process of the specimen (unit: kN), and t is the thickness of the right-angled specimen (unit: m).

[0074] 2. The flame retardant properties of the TPU films in each embodiment and comparative example were tested according to the standard test method for testing the flame retardant properties of materials in GB8624-2012 "Classification of Burning Performance of Building Materials and Products". The test conditions were 23±2℃ and 50%±5% relative humidity.

[0075] 3. The tensile strength of the TPU film in Examples 1-10 and Comparative Examples 1-4, and the PVC film in Comparative Example 5 were tested. The specific test methods are as follows:

[0076] Five dumbbell-shaped samples were cut from the TPU and PVC films, each measuring 115 mm × 6 mm and 0.5 mm thick. A universal tensile testing machine equipped with a high-precision load sensor and a large deformation extensometer was used. The samples were fixed with clamps to ensure that the dumbbell-shaped samples did not slip during the test. The universal tensile testing machine was started and a tensile force was applied to the samples at a specified speed (500 mm / min). The test conditions were 23±2℃ and 50%±5% relative humidity.

[0077] Calculate the maximum tensile stress (tensile strength) during the tensile process of the dumbbell-shaped specimen.

[0078] σ = F / (b×d)

[0079] Where σ is the tensile strength (unit: MPa), F is the maximum tensile force (unit: N), b is the width of the specimen (unit: mm), and d is the thickness of the specimen (unit: mm).

[0080] 4. The abrasion resistance of the TPU film in Examples 1-10 and Comparative Examples 1-4, and the PVC film in Comparative Example 5 were tested. The specific test methods are as follows:

[0081] Samples were 100mm × 100mm in size and 0.5mm thick, with a minimum of 5 samples. A Taber abrasion tester equipped with leather wheels was used, and 45μm abrasive particles were sprinkled on the sample surface. The mass of each sample was accurately weighed to ±0.1mg. One sample was placed on the abrasion tester and abraded at 5000 revolutions per minute. The test was paused and the sample mass was re-weighed after every 1000 revolutions. If the first sample was worn through within 5000 revolutions, it was discarded, and the remaining samples were tested. The test conditions were 23±2℃ and 50%±5% relative humidity. Volume loss was calculated using the following formula. The abrasion resistance rating standards are shown in Table 3.

[0082] Fv=Fm / ρ

[0083] Where Fv is the volume loss, Fm is the mass loss, and ρ is the density of the wear-resistant layer.

[0084] Table 3 Wear Resistance Grade

[0085]

[0086] 5. The yellowing resistance levels of the TPU films in Examples 1-10 and Comparative Examples 1-4, and the PVC film in Comparative Example 5 were tested. The specific test methods are as follows:

[0087] A rectangular sample measuring 60×200mm×0.5mm (length×width×thickness) was cut, with a thickness of 0.5mm. After being placed in a UV aging chamber for 168 hours, the color difference was compared with the original sample. The test conditions were 23±2℃ and 50%±5% relative humidity. The standards for yellowing grades are shown in Table 4.

[0088] Table 4 Yellowing Levels

[0089]

[0090] Table 5 Experimental data for each embodiment and comparative example

[0091]

[0092] The test results are shown in Table 5, where the flame retardant ratings are B1 > B2 > B3. By comparing the prepared TPU film with the purchased PVC film, it can be analyzed that the TPU film has significant advantages in tensile strength and tear strength; the addition of silica improves the abrasion resistance of the TPU film, while the abrasion resistance of PVC is lower than that of the TPU film. In some preferred embodiments, the prepared TPU film can achieve a B1 level flame retardant effect. In some preferred embodiments, the UV-resistant additive can effectively improve the yellowing resistance of the TPU film, making the overall TPU film less prone to yellowing and exhibiting high transparency.

[0093] The TPU film obtained above is laminated with a PU base film by applying adhesive to obtain a composite floor film. The resulting TPU film has good tensile and tear strength, as well as good wear resistance, flame retardancy, and yellowing resistance. The overall floor film, protected by the TPU layer, can play a role in wear resistance, flame retardancy, yellowing resistance, aging resistance, and corrosion resistance. In actual use, it can improve the service life of the floor film and has good application prospects.

[0094] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A TPU particle, characterized in that, By weight, it comprises the following raw material components: 40-90 parts of polyether polyol; 60-100 parts of diisocyanate; 3-20 parts flame retardant; 2-10 parts of silicon dioxide; 3-20 parts of light stabilizer.

2. The TPU particles as described in claim 1, characterized in that, It satisfies one or more of the following conditions (1)-(5): (1) The polyether polyol is 60-75 parts by weight; (2) The diisocyanate is in the form of 80-100 parts by weight; (3) The flame retardant is 3-15 parts by weight; (4) The silicon dioxide is present in parts by weight of 4-8 parts; and, (5) The light stabilizer is 3-15 parts by weight.

3. The TPU particles as described in claim 1, characterized in that, It satisfies one or more of the following conditions (1)-(10): (1) The polyether polyol is in the following weight parts: 60 parts, 65 parts, 70 parts or 75 parts; (2) The diisocyanate is in the following weight parts: 80 parts, 85 parts, 90 parts, 95 parts or 100 parts; (3) The flame retardant is present in parts by weight of 3, 5, 7, 9 or 15. (4) The silicon dioxide is in the form of 4 parts, 6 parts or 8 parts by weight; (5) The light stabilizer is present in parts by weight of 3, 5, 7, 10 or 15 parts; (6) The silica is powdered silica, nano silica or fumed silica; (7) The flame retardant is a halogen-free flame retardant; (8) The light stabilizer is one or more of UV-5411 ultraviolet absorber, UV-770 light stabilizer and UV-3529 stabilizer; (9) The raw material components of the TPU particles also include chain extenders; and, (10) The raw material components of the TPU particles also include one or more of antioxidants, lubricants, plasticizers and dispersants.

4. The TPU particles as described in claim 3, characterized in that, It satisfies one or more of the following conditions (1)-(12): (1) The flame retardant is a phosphonate flame retardant; (2) The light stabilizer is a combination of UV-5411 ultraviolet absorber, UV-770 light stabilizer and UV-3529 light stabilizer, and the mass ratio of UV-5411 ultraviolet absorber, UV-770 light stabilizer and UV-3529 light stabilizer is 1:2:3; (3) The chain extender is 1,4-butanediol; (4) The chain extender is 20-50 parts by weight; (5) The antioxidant is antioxidant 1010; (6) The antioxidant is present in parts by weight of 1-5 parts; (7) The lubricant is zinc stearate or zinc stearate; (8) The lubricant is 3-10 parts by weight; (9) The plasticizer is dioctyl phthalate; (10) The plasticizer is 3-10 parts by weight; (11) The dispersant is stearic acid amine; and, (12) The dispersant has a weight of 2-8 parts.

5. A method for preparing TPU particles, characterized in that, It includes the following steps: mixing the raw material components of TPU particles as described in any one of claims 1-4, pelletizing them, and obtaining TPU particles.

6. The method for preparing TPU particles as described in claim 5, characterized in that, It satisfies one or more of the following conditions (1)-(4): (1) The mixing temperature is 170-210℃; (2) The mixing time is 3-5 minutes; (3) The pelletizing process further includes a cooling step, wherein cooling is performed using cooling water, and the cooling temperature reaches 5°C; and, (4) The pelleting process includes a drying step, wherein the drying temperature is 90-100℃ and the drying time is 3-4h.

7. A TPU film, characterized in that, It is made from TPU particles as described in any one of claims 1-4.

8. A method for preparing a TPU film, characterized in that, It includes the following steps: melt-blending TPU particles as described in any one of claims 1-4, casting, and obtaining a TPU film.

9. A composite floor membrane, characterized in that, It includes a base film and the TPU film as described in claim 7.

10. The composite floor membrane as described in claim 9, characterized in that, It meets the following conditions (1) and / or (2): (1) The base film is a PU film, and the thickness of the PU film is 0.3-1.2 mm; (2) The thickness ratio of the TPU film to the base film is 1:(1-2).

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