High light transmittance high weather resistance thermoplastic polyurethane elastomer

Abstract

The application provides a high-transmittance high-weather-resistance thermoplastic polyurethane elastomer, which comprises a reaction product of aliphatic polyisocyanate, polymer polyol and chain extender, wherein the polymer polyol comprises polycarbonate polyol PCDL; the aliphatic polyisocyanate comprises dicyclohexylmethane H12MDI and other types of aliphatic polyisocyanate; and the chain extender comprises small-molecule dihydric alcohol, which comprises a mixture of cyclic small-molecule dihydric alcohol and acyclic small-molecule dihydric alcohol. The high-transmittance high-weather-resistance thermoplastic polyurethane elastomer has good mechanical properties and good yellowing resistance, and the transparency is obviously higher than that of conventional thermoplastic polyurethane. When the thermoplastic polyurethane elastomer is applied to safety glass interlayer material, the adhesion of the thermoplastic polyurethane elastomer to glass is excellent, and no obvious yellowing and degradation phenomenon occurs during long-term outdoor use.

Description

Technical Field

[0001] This invention relates to a thermoplastic polyurethane elastomer, specifically to a thermoplastic polyurethane elastomer with high light transmittance and high weather resistance, and its applications. Background Technology

[0002] Thermoplastic polyurethane (TPU) elastomer is a promising new type of organic polymer synthetic material. Its unique block linear molecular structure and structural designability endow TPU with excellent tensile properties, resilience, aging resistance and weather resistance. Therefore, TPU can be widely used in many fields such as footwear and clothing, medical and health care, electronic devices, wires and cables and automotive parts.

[0003] In the construction and transportation sectors, especially in special applications such as automobiles, airplanes, high-speed trains, warships, and windows and doors in high-rise buildings where safety requirements are high, the impact resistance and safety of safety glass are crucial. Laminated glass, due to its superior impact resistance and high safety profile (less likely to cause injury even if broken), has been successfully applied in high-speed train windshields, Tesla sunroofs, command tower windows on military vessels, and armored vehicle windows. Laminated glass is a flat or curved composite glass product made by hot-pressing two or more sheets of flat glass together with a transparent resin sheet. The resin interlayer prevents the glass from shattering into radial cracks upon impact, thus preventing injury. The impact resistance of the product is therefore significantly higher than that of ordinary glass. Furthermore, by using different glass sheets and interlayer materials, properties such as light resistance, heat resistance, moisture resistance, and cold resistance can be achieved. The quality of laminated glass depends mainly on the strength, transparency, weather resistance, moisture resistance, and glass bonding strength of the resin interlayer. Aliphatic TPU is an ideal material for laminated glass interlayers due to its excellent yellowing resistance, moisture resistance, high strength, and excellent glass bonding performance. Summary of the Invention

[0004] Technical problem: The purpose of this invention is to provide a high light transmittance and high weather resistance thermoplastic polyurethane elastomer, and to use this thermoplastic polyurethane elastomer for modification and processing in the field of glass interlayer materials.

[0005] Technical solution: The present invention provides a high light transmittance and high weather resistance thermoplastic polyurethane elastomer, comprising a reaction product obtained from aliphatic polyisocyanate, polymer polyol, and chain extender, wherein the polymer polyol includes polycarbonate polyol PCDL.

[0006] The polymer polyols include polycarbonate polyol PCDL and other types of polymer polyols; the mass ratio of polycarbonate polyol PCDL to other types of polymer polyols is 1:0.1 to 1:0.8.

[0007] Other types of polymeric polyols include polyether polyols, which include at least one of polytetramethylene ether polyol PTMEG, polypropylene oxide polyol PPG, polyethylene oxide polyol PEG, and polyethylene oxide-propylene polyol P (EG-PG). Preferably, the polyether polyol is polytetramethylene ether polyol PTMEG.

[0008] The polycarbonate polyol PCDL has a number-average molecular weight of 1000–4000 g / mol, and the polyether polyol has a number-average molecular weight of 1000–2500 g / mol.

[0009] The aliphatic polyisocyanates include dicyclohexylmethane (H12MDI) and other types of aliphatic polyisocyanates, wherein the other types of aliphatic polyisocyanates include at least one of dicyclohexylmethane diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), and preferably, the other types of aliphatic polyisocyanates include isophorone diisocyanate (IPDI).

[0010] The mass ratio of the dicyclohexylmethane H12MDI to other types of aliphatic polyisocyanates is 1:0.02 to 1:0.7.

[0011] The chain extender includes small molecule diols, which include a mixture of cyclic and acyclic small molecule diols.

[0012] The acyclic small molecule diols include one or more of ethylene glycol (EG), propylene glycol (PG), butanediol (BDO), pentanediol (PD), neopentanediol (NPG), and hexanediol (HG); the acyclic small molecule diols account for 50-90% of the total mass of the chain extender, preferably 65-85%; the cyclic small molecule diols include one or more of 1,2-cyclobutanediethanol, 1,3-cyclobutanediethanol, and 1,4-cyclohexanediethanol.

[0013] The high light transmittance and high weather resistance thermoplastic polyurethane elastomer is obtained by reacting the following raw materials in parts by weight:

[0014] 30-45 parts by weight of aliphatic polyisocyanates;

[0015] 35-65 parts by weight of polymeric polyol;

[0016] Chain extender 5-15 parts by weight;

[0017] The isocyanate index is 0.95:1 to 1.05:1; the isocyanate index is the molar ratio of NCO groups in the polyisocyanate to NCO-reactive groups in the polymer polyol, chain extender and end capping agent.

[0018] The high-transmittance, high-weather-resistant thermoplastic polyurethane elastomer further contains at least one of an antioxidant and an ultraviolet absorber; the antioxidant includes one or more of antioxidant 168, antioxidant 1010, antioxidant 1024, antioxidant 264, and antioxidant 245, and the amount of the antioxidant added is 0-5 wt%, calculated based on the total mass of the thermoplastic polyurethane elastomer; the ultraviolet absorber includes one or more of R-455, UV-329, UV-531, UV-326, and UV-328, and the amount of the ultraviolet absorber added is 0-5 wt%, calculated based on the total mass of the thermoplastic polyurethane elastomer.

[0019] Beneficial effects: The high light transmittance and high weather resistance thermoplastic polyurethane elastomer of the present invention not only has excellent mechanical properties and good resistance to yellowing, but also has a significantly higher transparency than conventional thermoplastic polyurethane. When applied to safety glass laminated materials, this thermoplastic polyurethane material has excellent adhesion to glass, and no obvious yellowing or deterioration occurs even after long-term outdoor use. Detailed Implementation

[0020] This invention provides a high light transmittance and high weather resistance thermoplastic polyurethane elastomer, which is then modified and processed for use in the field of glass interlayer materials.

[0021] The high light transmittance and high weather resistance thermoplastic polyurethane elastomer provided by the present invention comprises a reaction product obtained from aliphatic polyisocyanate, polymer polyol, and chain extender, wherein the polymer polyol includes polycarbonate polyol PCDL.

[0022] Furthermore, the polymer polyols include polycarbonate polyols (PCDL) and other types of polymer polyols;

[0023] The other types of polymeric polyols include polyether polyols, which include at least one of polytetramethylene ether polyol PTMEG, polypropylene oxide polyol PPG, polyethylene oxide polyol PEG, and polyethylene oxide-propylene polyol P (EG-PG). Further, the polyether polyol is preferably polytetramethylene ether polyol PTMEG.

[0024] The mass ratio of the PCDL to other types of polymeric polyols is 1:0.1 to 1:0.8;

[0025] Furthermore, the mass ratio of the PCDL to other types of polymeric polyols is 1:0.2 to 1:0.6;

[0026] The PCDL has a number-average molecular weight of 1000–3000 g / mol, and the polyether polyol has a number-average molecular weight of 1000–2500 g / mol.

[0027] In some embodiments of the invention, the polymeric polyol comprises PCDL and PTMEG in a mass ratio of 1:0.2 to 1:0.6;

[0028] The aliphatic polyisocyanates include dicyclohexylmethane (H12MDI) and other types of aliphatic polyisocyanates, wherein the other types of aliphatic polyisocyanates include at least one of dicyclohexylmethane diisocyanate (IPDI) and hexamethylene diisocyanate (HDI).

[0029] Preferably, the other types of aliphatic polyisocyanates include dicyclohexylmethane diisocyanate (IPDI).

[0030] Preferably, the mass ratio of H12MDI to other types of aliphatic polyisocyanates is 1:0.03 to 1:0.7;

[0031] In some embodiments of the invention, the aliphatic polyisocyanate comprises H12MDI and IPDI in a mass ratio of 1:0.03 to 1:0.7;

[0032] The chain extender includes small molecule diols, further, the small molecule diols contain cyclic structures, and further, includes a mixture of acyclic small molecule diols and cyclic small molecule diols.

[0033] The acyclic small molecule diols include one or more of ethylene glycol (EG), propylene glycol (PG), butanediol (BDO), pentanediol (PD), neopentanediol (NPG), and hexanediol (HG).

[0034] The cyclic small molecule diols include one or more of 1,2-cyclobutanediethanol, 1,3-cyclobutanediethanol, and 1,4-cyclohexanediethanol.

[0035] The acyclic small molecule diol accounts for 50-90% of the total mass of the chain extender, preferably 65-85%;

[0036] Furthermore, the aforementioned high light transmittance and high weather resistance thermoplastic polyurethane elastomer is obtained by reacting the following raw materials in parts by weight:

[0037] 30-45 parts by weight of aliphatic polyisocyanates;

[0038] 40-65 parts by weight of polymeric polyol;

[0039] 7-15 parts by weight of chain extender;

[0040] Furthermore, the isocyanate index of the high light transmittance and high weather resistance thermoplastic polyurethane elastomer is 0.97:1 to 1.03:1;

[0041] The isocyanate index is the molar ratio of NCO groups in the polyisocyanate to NCO-reactive groups in the polymer polyol, chain extender, and capping agent.

[0042] The high light transmittance and high weather resistance thermoplastic polyurethane elastomer also contains at least one of antioxidants and ultraviolet light absorbers;

[0043] The antioxidants include one or more of antioxidant 168, antioxidant 1010, antioxidant 1024, antioxidant 264, and antioxidant 245; the amount of antioxidant added is 0-5 wt%, calculated based on the total mass of the thermoplastic polyurethane elastomer.

[0044] The ultraviolet light absorber includes one or more of R-455, UV-329, UV-531, UV-326, and UV-328; the amount of the ultraviolet light absorber added is 0 to 5 wt%, calculated based on the total mass of the thermoplastic polyurethane elastomer.

[0045] The high-transmittance, high-weather-resistant thermoplastic polyurethane elastomer is prepared by mixing and reacting aliphatic polyisocyanate, polymeric polyol, and chain extender.

[0046] The reaction equipment is not particularly limited, as long as it can ensure that the raw materials of each component can be fully mixed or reacted. For example, it can be selected from one or more of the following: screw extruder, internal mixer, stirred tank, and casting machine.

[0047] Furthermore, the high light transmittance and high weather resistance thermoplastic polyurethane elastomer is prepared in the presence of a protective gas that does not participate in the reaction, such as nitrogen or helium.

[0048] Furthermore, catalysts commonly used in the art can be added during the mixed reaction process to accelerate the reaction rate; including one or more of organotin catalysts, organotitanium catalysts, and organobismuth catalysts.

[0049] In some embodiments of the present invention, the high light transmittance and high weather resistance thermoplastic polyurethane elastomer is prepared using a twin-screw extruder, the steps of which include:

[0050] The insulation temperature for aliphatic polyisocyanates is 40–80℃, the insulation temperature for polymeric polyols is 90–130℃, and the insulation temperature for chain extenders is 40–80℃, to ensure that the raw materials are in a liquid state.

[0051] The above-mentioned heat-insulated polyisocyanate, polymer polyol, and chain extender are added to the front section of a twin-screw extruder through a mixing system for mixing and reaction. The screw temperature is controlled at 140-180℃. The resulting polymer melt is obtained by underwater pelletizing and drying.

[0052] Preferably, the catalyst is selectively added to the front section of the twin-screw extruder and mixed with the raw materials, while the antioxidant, ultraviolet absorber, and lubricant are selectively added to the rear section of the twin-screw extruder and mixed with the molten thermoplastic polyurethane elastomer. Alternatively, the prepared thermoplastic polyurethane elastomer particles and other materials can be melted and mixed again in the mixer.

[0053] Preferably, other additives in the art may be further added to the high light transmittance and high weather resistance thermoplastic polyurethane elastomer as needed to improve the performance of the thermoplastic polyurethane elastomer.

[0054] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0055] The high-transmittance, high-weather-resistant thermoplastic polyurethane elastomers of the examples and comparative examples are obtained by reacting the raw materials in the parts by weight shown in Table 1 below:

[0056] Table 1:

[0057]

[0058]

[0059] The above embodiments and comparative examples all use a twin-screw extruder to prepare the high light transmittance and high weather resistance thermoplastic polyurethane elastomer, and the steps include:

[0060] According to the weight proportions in Table 1, the above-mentioned heat-insulated polyisocyanate, polymer polyol, and chain extender are added to the front section of a twin-screw extruder through a mixing system for mixing and reaction. The screw temperature is controlled at 140-180℃. The resulting polymer melt is obtained by underwater pelletizing and drying.

[0061] 0.2 parts by weight of stannous octoate catalyst were added to the front section of the twin-screw and mixed with the raw materials. The antioxidants, ultraviolet absorbers, light stabilizers and other additives listed in Table 2 were added to the rear section of the twin-screw and mixed with the molten thermoplastic polyurethane elastomer. The mixture was then dried by underwater pelletizing.

[0062] Table 2:

[0063]

[0064] The thermoplastic polyurethane elastomers prepared in the examples and comparative examples were subjected to the following performance tests:

[0065] Hardness: ASTM D2240;

[0066] Tensile strength: ASTM D412;

[0067] Haze: ASTM D1003;

[0068] Glass bonding grade: Vacuum bond the TPU film between two 200mm×200mm pieces of glass at 125℃, then freeze at -20℃ for 2 hours. Use a 0.5kg hammer to gently tap 50% of the glass on an inclined surface until the glass shatters. Then tap the other side and check the percentage of the area of ​​the film that is exposed on both sides. A glass bonding grade of 10 indicates that no film is exposed, and 0 indicates that it is completely peeled off. The smaller the number, the lower the bonding grade.

[0069] Yellowing resistance: dE was tested after 100 hours of xenon lamp aging.

[0070] The performance data results are shown in Table 3 below:

[0071] Table 3:

[0072]

Claims

1. A thermoplastic polyurethane elastomer with high light transmittance and high weather resistance, characterized in that, The reactants include aliphatic polyisocyanates, polymeric polyols, and chain extenders, wherein the polymeric polyols include polycarbonate polyols (PCDL). The polymer polyol is composed of polycarbonate polyol PCDL and other types of polymer polyols; the mass ratio of polycarbonate polyol PCDL to other types of polymer polyols is 1:0.1 to 1:0.8; the other types of polymer polyols are polyether polyols. The aliphatic polyisocyanates include dicyclohexylmethane (H12MDI) and other types of aliphatic polyisocyanates, wherein the other types of aliphatic polyisocyanates are isophorone diisocyanate (IPDI). The chain extender includes small molecule diols, which include a mixture of cyclic and acyclic small molecule diols, and the cyclic small molecule diols include 1,4-cyclohexanediol. Aliphatic polyisocyanates include H12MDI and IPDI in a mass ratio of 1:0.03 to 1:0.7; The high-transmittance, high-weather-resistant thermoplastic polyurethane elastomer also contains an ultraviolet light absorber, including R-455.

2. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 1, characterized in that, The polyether polyols include at least one of polytetramethylene ether polyol PTMEG, polypropylene oxide polyol PPG, polyethylene oxide polyol PEG, and polyethylene oxide-propylene polyol P (EG-PG).

3. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 1, characterized in that, The polyether polyols mentioned include polytetramethylene ether polyol PTMEG.

4. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 2, characterized in that, The polycarbonate polyol PCDL has a number-average molecular weight of 1000~4000 g / mol, and the polyether polyol has a number-average molecular weight of 1000~2500 g / mol.

5. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 1, characterized in that, The acyclic small molecule diols include one or more of ethylene glycol (EG), propylene glycol (PG), butanediol (BDO), pentanediol (PD), neopentanediol (NPG), and hexanediol (HG); the acyclic small molecule diols account for 50-90% of the total mass of the chain extender, and the cyclic small molecule diols also include one or more of 1,2-cyclobutanediethanol and 1,3-cyclobutanediethanol.

6. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 5, characterized in that, The acyclic small molecule diol accounts for 65-85% of the total mass of the chain extender.

7. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 1, characterized in that, The high light transmittance and high weather resistance thermoplastic polyurethane elastomer is obtained by reacting the following raw materials in parts by weight: 30-45 parts by weight of aliphatic polyisocyanates; 35-65 parts by weight of polymeric polyol; Chain extender 5-15 parts by weight; The isocyanate index is 0.95:1 to 1.05:1; the isocyanate index is the molar ratio of NCO groups in the polyisocyanate to NCO-reactive groups in the polymer polyol, chain extender and end capping agent.

8. The high light transmittance and high weather resistance thermoplastic polyurethane elastomer according to claim 1, characterized in that, The high-transmittance, high-weather-resistant thermoplastic polyurethane elastomer further contains antioxidants; the antioxidants include one or more of antioxidants 168, 1010, 1024, 264, and 245, and the amount of the antioxidant added is 0-5 wt% and not zero, calculated based on the total mass of the thermoplastic polyurethane elastomer; the amount of the ultraviolet absorber added is 0-5 wt% and not zero, calculated based on the total mass of the thermoplastic polyurethane elastomer.

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