Low-dielectric and high-hydrophobicity fluorine-containing polyester polyurethane and preparation method thereof
By introducing a trimer of fluorinated polyester diol and hexamethylene diisocyanate into polyester polyurethane, a fluorinated polyester polyurethane with low dielectric constant and high hydrophobicity is formed, which solves the problems of high dielectric constant and poor hydrophobicity of polyester polyurethane and is suitable for 5G electronic packaging materials.
Patent Information
- Application Number
- CN202510949949.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-11-14
AI Technical Summary
Existing polyester-based polyurethane materials have high dielectric constants, poor hydrophobicity, and weak waterproof and stain-resistant capabilities, which cannot meet the requirements of 5G electronic packaging materials.
A fluorinated polyester polyurethane with low dielectric and high hydrophobicity is formed by introducing fluorine into the polyester polyol through copolymerization modification using a trimer of fluorinated polyester diol and hexamethylene diisocyanate.
It reduces the dielectric constant of the material, improves hydrophobicity and waterproof and stain-resistant properties, and is suitable for 5G electronic packaging materials.
Smart Images
Figure CN120944071A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a fluorinated polyester polyurethane and its preparation method, belonging to the field of polyurethane synthesis technology. Background Technology
[0002] With the rapid development and popularization of fifth-generation mobile communication technology (5G), electronic devices and equipment are constantly developing towards higher frequency, higher speed, higher integration and miniaturization. This puts forward higher requirements for the dielectric performance of 5G electronic packaging materials, and the development of a suitable low dielectric material has become a research focus.
[0003] Polyurethane materials generally refer to a class of polymer materials with a large number of urethane groups on their molecular backbone. Since the development of polyurethane materials in the 1930s, they have received widespread attention due to their excellent properties and ease of processing. The presence of numerous polar groups in the structure of polyurethane materials, such as urethane groups and ester groups, gives them good mechanical properties, wear resistance, and thermal properties. Furthermore, polyurethane materials are easy to process and inexpensive, and have been applied in various fields such as wires and cables, and electronic devices. The raw materials for preparing polyurethane materials mainly include polyols, polyisocyanates, and chain extenders. [1] Polyurethane materials are mainly composed of two parts: rigid segments (hard segments) and flexible segments (soft segments). Rigid segments are primarily obtained by reacting isocyanates with small-molecule alcohols or amines, while flexible segments are mainly composed of polyols. The main raw material for flexible segments is usually polyester diols or polyether diols. Based on the type of polyol, polyurethane can be classified into polyester polyurethane and polyether polyurethane. Polyether polyurethane uses polyether polyols whose main chain consists of alkane groups linked by ether bonds, exhibiting good flexibility. Commonly used polyether polyols include polyethylene glycol ethers. In contrast, polyester polyurethane uses polyester polyols synthesized from diols and diacids, resulting in hydroxyl-terminated polyester oligomers with ester groups. Due to the presence of polar ester groups, polyester polyurethane possesses better low-temperature physical properties and superior mechanical properties. However, polyester polyurethane materials have poor hydrolysis resistance and weak waterproofing and stain resistance, leading to significant waste and losses. Furthermore, the large number of polar groups in polyester polyurethane materials results in a high dielectric constant, hindering its large-scale application in the 5G field.
[0004] F element itself has extremely high electronegativity and low atomic radius, which makes it easy to form CF bonds with high bond energy in polymer materials. The low polarizability of CF bonds increases the free volume and reduces hygroscopicity, thereby reducing the dielectric constant. In organic fluorine-containing materials, F atoms migrate to the surface of the material, giving it lower molecular cohesion and surface free energy. Therefore, introducing fluorine into materials can improve properties such as water resistance, oil resistance, and stain resistance.
[0005] Therefore, there is an urgent need for a low-dielectric, highly hydrophobic fluorinated polyester polyurethane and its preparation method to solve the above-mentioned technical problems. Summary of the Invention
[0006] To address the problems of high dielectric constant, poor hydrophobicity, and weak waterproof and stain-resistant properties of existing polyester-type polyurethane materials, this invention proposes a low dielectric, highly hydrophobic fluorinated polyester-type polyurethane and its preparation method.
[0007] The technical solution adopted by the present invention to solve the above problems is as follows: The low dielectric and high hydrophobic fluorinated polyester polyurethane of the present invention comprises a fluorinated polyester diol, a trimer of hexamethylene diisocyanate, a non-fluorinated polyester diol and a catalyst.
[0008] Furthermore, the fluorine-free polyester diol is a phthalic anhydride-based polyester polyol, obtained by melt polymerization of phthalic anhydride with ethylene glycol, butanediol and other diols.
[0009] Furthermore, the fluorinated polyester diol is a hydroxyl-terminated fluorinated polyester oligomer, which is obtained by melt polymerization of a fluorinated diol and phthalic anhydride as raw materials.
[0010] The preparation method of the low dielectric and highly hydrophobic fluorinated polyester polyurethane of the present invention includes the following steps:
[0011] Step 1: Add the fluorinated diol and phthalic anhydride to a four-necked flask, purge the system with high-purity nitrogen to remove air, and rapidly heat the mixture to 120-140°C in a nitrogen atmosphere until the raw materials melt.
[0012] Step 2: After the phthalic anhydride has completely melted, heat the mixture to 150-165℃ and react for 3 hours, increasing the stirring rate in the last 30 minutes.
[0013] Step 3: Add catalyst, then continue heating to 170-180℃ and react for 30 minutes. Then add desiccant and dehydrating agent and continue reacting for 3 hours.
[0014] Step 4: Use a vacuum water pump to create a vacuum. The vacuum level will increase over time. After 15 hours of vacuuming, discharge the product. Dissolve the product in a solvent and then filter it.
[0015] Step 5: Add alkaline solution until the filtrate is neutral, then wash and separate the liquid three times with distilled water.
[0016] Step 6: Vacuum drying yields the pure product, fluorinated polyester diol;
[0017] Step 7: Mix the fluorinated polyester diol and the non-fluorinated polyester diol evenly;
[0018] Step 8: Add solvent to reduce viscosity, then add hexamethylene diisocyanate trimer as curing agent and stir continuously until fully mixed. Then add catalyst and continue stirring.
[0019] Step 9: After stirring, pour the mixture into a polytetrafluoroethylene mold and vacuum degas it in an oven at 55-65℃. Then, place it in an oven at 65℃ to continue curing for 10 days.
[0020] Furthermore, the fluorinated diol in step 1 has a molecular weight of 800 g / mol and the following molecular structure:
[0021]
[0022] Both m and n are positive integers;
[0023] The molar ratio of fluorinated diol to phthalic anhydride is 1:1.
[0024] Furthermore, in step 3, the catalyst is concentrated sulfuric acid with a concentration of 98%, and the amount of concentrated sulfuric acid catalyst used is 6% of the molar amount of phthalic anhydride.
[0025] The desiccant is anhydrous magnesium sulfate, which is dried in an oven at 200°C. The mass of the anhydrous magnesium sulfate added is 15% of the total mass of the raw materials.
[0026] The dehydrating agent is xylene, and the mass of xylene added is 25% of the total mass of the raw materials.
[0027] Furthermore, in step 4, the solvent is one or more of ethyl acetate and ethanol.
[0028] Furthermore, in step 5, the alkaline solution is one or more of a saturated potassium bicarbonate solution and a saturated sodium bicarbonate solution.
[0029] Furthermore, in step 7, the mass ratio of fluorinated polyester diol to non-fluorinated polyester diol includes 1:0, 1:1, 3:1, 1:3, and 0:1.
[0030] Furthermore, in step 8, the amount of trimer of the curing agent hexamethylene diisocyanate added is 25.85% of the total mass of the diol;
[0031] The catalyst is dibutyltin dilaurate, and the added mass is % of the total mass.
[0032] The solvent is ethyl acetate, and the added mass is 50% of the total mass of the diol.
[0033] The beneficial effects of this invention are as follows: The fluorinated diol used in this invention has a large molecular weight and low activity. Fluorine is introduced into the internal structure of the polyester polyol through copolymerization modification, thereby fluorinating the polyester polyurethane. This modification method requires less fluorine reagent and produces a product with excellent and stable performance. During the curing process of the fluorinated polyester polyol to form fluorinated polyester polyurethane, the fluorinated segments migrate to the sample surface, reducing the surface free energy of the material and thus achieving a better hydrophobic effect. At the same time, the induced polarizability of the introduced CF bond is relatively small, and the polarization intensity generated under the action of an external electric field is relatively low. Furthermore, the presence of fluorine reduces the hygroscopicity of the sample, increases the free volume, and thus reduces the dielectric constant of the material. Attached Figure Description
[0034] Figure 1 This is a schematic diagram of the infrared curve of the fluorinated polyester diol synthesized in Example 1;
[0035] Figure 2 This is a schematic diagram of the molecular weight distribution curves of fluorinated polyester diols and non-fluorinated polyester diols.
[0036] Figure 3 These are schematic diagrams of the dielectric properties of Examples 1 to 4 and Comparative Example 1;
[0037] Figure 4 These are schematic diagrams of the water contact angles in Examples 1 to 4 and Comparative Example 1. Example
[0038] Example 1
[0039] A method for preparing a fluorinated polyester-type polyurethane includes the following steps:
[0040] Step 1: First, the fluorinated diol was dehydrated in a vacuum oven at 100℃. Then, 7.41g of phthalic anhydride and 40g of the fluorinated diol were added to a four-necked flask and stirred. The temperature was rapidly raised to 120℃ under a nitrogen atmosphere, and stirring was continued at this temperature to gradually dissolve the phthalic anhydride powder. After the phthalic anhydride was completely dissolved, the temperature was raised to 150℃ and reacted for 3 hours. In the last 30 minutes, the stirring rate was increased, and 0.294g of concentrated sulfuric acid was added. The temperature was then raised to 170℃ and reacted for 30 minutes. 7.05g of anhydrous magnesium sulfate and 11.75g of xylene were added and the reaction continued for 3 hours. Vacuum was applied using a vacuum pump, and the vacuum degree was continuously increased over time. After 15 hours of vacuuming, the product was discharged. The product was dissolved in ethyl acetate and filtered. Then, a saturated aqueous solution of sodium bicarbonate was added until the filtrate was neutral. The product was then washed with distilled water and separated three times. Finally, it was vacuum dried to obtain the pure product, fluorinated polyester diol.
[0041] Step 2: Take 6g of the fluorinated polyester diol obtained in Step 1 and dry it in an oven at 120℃ for 6 hours. Then, add it to a flask with 3g of ethyl acetate and stir. Then, add 1.551g of 3HDI and 24μg of dibutyltin dilaurate and continue stirring until uniform. Place it in an oven at 65℃ and remove the solvent ethyl acetate and air bubbles by vacuuming. Then, pour it into a polytetrafluoroethylene mold and cure it at a constant temperature of 65℃ for 10 days.
[0042] Example 2
[0043] A method for preparing a fluorinated polyester-type polyurethane includes the following steps:
[0044] Step 1: First, the fluorinated diol was dehydrated in a vacuum oven at 100℃. Then, 5.55g of phthalic anhydride and 30g of the fluorinated diol were added to a four-necked flask and stirred. The temperature was rapidly raised to 125℃ under a nitrogen atmosphere, and stirring was continued at this temperature to gradually dissolve the phthalic anhydride powder. After the phthalic anhydride was completely dissolved, the temperature was raised to 160℃ and reacted for 3 hours. In the last 30 minutes, the stirring rate was increased, and 0.221g of concentrated sulfuric acid was added. The temperature was then raised to 175℃ and reacted for 30 minutes. Then, 5.29g of anhydrous magnesium sulfate and 8.81g of xylene were added and the reaction was continued for 3 hours. Vacuum was applied using a vacuum pump, and the vacuum degree was continuously increased over time. After 15 hours of vacuuming, the product was discharged. The product was dissolved in ethyl acetate and filtered. Then, a saturated aqueous solution of sodium bicarbonate was added until the filtrate was neutral. The product was then washed with distilled water and separated three times. Finally, it was vacuum dried to obtain the pure product, fluorinated polyester diol.
[0045] Step 2: Take 4.5g of the fluorinated polyester diol obtained in Step 1 and dry it in an oven at 120℃ for 6 hours. Then, add it to a flask with 3g of ethyl acetate and 1.5g of phthalic anhydride-based polyester diol and stir. Then, add 1.551g of 3HDI and 24μg of dibutyltin dilaurate and continue stirring until uniform. Place it in an oven at 60℃ and remove the solvent ethyl acetate and air bubbles by vacuuming. Then, pour it into a polytetrafluoroethylene mold and cure it in an oven at 65℃ for 10 days.
[0046] Example 3
[0047] A method for preparing a fluorinated polyester-type polyurethane includes the following steps:
[0048] Step 1: First, the fluorinated diol was dehydrated in a vacuum oven at 100℃. Then, 3.70g of phthalic anhydride and 20g of the fluorinated diol were added to a four-necked flask and stirred. The temperature was rapidly raised to 130℃ under a nitrogen atmosphere, and stirring was continued at this temperature to gradually dissolve the phthalic anhydride powder. After the phthalic anhydride was completely dissolved, the temperature was raised to 155℃ and reacted for 3 hours. In the last 30 minutes, the stirring rate was increased, and 0.147g of concentrated sulfuric acid was added. The temperature was then raised to 175℃ and reacted for 30 minutes. Then, 3.53g of anhydrous magnesium sulfate and 5.88g of xylene were added and the reaction was continued for 3 hours. Vacuum was applied using a vacuum pump, and the vacuum degree was continuously increased over time. After 15 hours of vacuuming, the product was discharged. The product was dissolved in ethyl acetate and filtered. Then, a saturated aqueous solution of sodium bicarbonate was added until the filtrate was neutral. The product was then washed with distilled water and separated three times. Finally, it was vacuum dried to obtain the pure product, fluorinated polyester diol.
[0049] Step 2: Take 3g of the fluorinated polyester diol obtained in Step 1 and dry it in an oven at 120℃ for 6 hours. Then, add it to a four-necked flask with 3g of ethyl acetate and 3g of phthalic anhydride-based polyester diol and stir. Then, add 1.551g of 3HDI and 24μg of dibutyltin dilaurate and continue stirring until uniform. Place it in an oven at 55℃ and remove the solvent ethyl acetate and air bubbles by vacuuming. Then, pour it into a polytetrafluoroethylene mold and cure it at a constant temperature of 65℃ for 10 days.
[0050] Example 4
[0051] A method for preparing a fluorinated polyester-type polyurethane includes the following steps:
[0052] Step 1: First, the fluorinated diol was dehydrated in a vacuum oven at 100℃. Then, 1.85g of phthalic anhydride and 10g of the fluorinated diol were added to a four-necked flask and stirred. The temperature was rapidly raised to 140℃ under a nitrogen atmosphere, and stirring was continued at this temperature to gradually dissolve the phthalic anhydride powder. After the phthalic anhydride was completely dissolved, the temperature was raised to 165℃ and reacted for 3 hours. In the last 30 minutes, the stirring rate was increased, and 0.074g of concentrated sulfuric acid was added. The temperature was then raised to 180℃ and reacted for 30 minutes. Then, 1.76g of anhydrous magnesium sulfate and 2.94g of xylene were added and the reaction was continued for 3 hours. Vacuum was applied using a vacuum pump, and the vacuum degree was continuously increased over time. After 15 hours of vacuuming, the product was discharged. The product was dissolved in ethyl acetate and filtered. Then, a saturated aqueous solution of sodium bicarbonate was added until the filtrate was neutral. The product was then washed with distilled water and separated three times. Finally, it was vacuum dried to obtain the pure product, fluorinated polyester diol.
[0053] Step 2: Take 1.5g of the fluorinated polyester diol obtained in Step 1 and dry it in an oven at 120℃ for 6 hours. Then, add it to a flask with 3g of ethyl acetate and 4.5g of phthalic anhydride-based polyester diol and stir. Then, add 1.551g of 3HDI and 24μg of dibutyltin dilaurate and continue stirring until uniform. Place it in an oven at 65℃ and remove the solvent ethyl acetate and air bubbles by vacuuming. Then, pour it into a polytetrafluoroethylene mold and cure it in an oven at 60℃ for 10 days.
[0054] Comparative Example 1
[0055] A method for preparing a fluorine-free polyester polyurethane includes the following steps: 6g of phthalic anhydride-based polyester diol and 3g of ethyl acetate are added to a flask and stirred. Then, 1.551g of 3HDI and 24μg of dibutyltin dilaurate are added and stirred until homogeneous. The flask is then placed in a 65℃ oven and vacuumed to remove the solvent ethyl acetate and air bubbles. Finally, the mixture is poured into a polytetrafluoroethylene mold and cured at a constant temperature of 65℃ for 10 days.
[0056] The monomer addition amounts for preparing polyester-type polyurethanes in Examples 1-4 and Comparative Example 1 are shown in the table below.
[0057]
[0058]
[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.
Claims
1. A low-dielectric, highly hydrophobic fluorinated polyester polyurethane, characterized in that, It includes fluorinated polyester diols, trimers of hexamethylene diisocyanate, non-fluorinated polyester diols, and catalysts.
2. The low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 1, characterized in that, The fluorine-free polyester diol is a phthalic anhydride-based polyester polyol, obtained by melt polymerization of phthalic anhydride with ethylene glycol, butanediol and other diols.
3. The low dielectric and highly hydrophobic fluorinated polyester polyurethane according to claim 1, characterized in that, Fluorinated polyester diols are hydroxyl-terminated fluorinated polyester oligomers obtained by melt polymerization of fluorinated diols and phthalic anhydride as raw materials.
4. A method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane, characterized in that, The specific steps include: Step 1: Add the fluorinated diol and phthalic anhydride to a four-necked flask, purge the system with high-purity nitrogen to remove air, and rapidly heat the mixture to 120-140°C in a nitrogen atmosphere until the raw materials melt. Step 2: After the phthalic anhydride has completely melted, heat the mixture to 150-165℃ and react for 3 hours, increasing the stirring rate in the last 30 minutes. Step 3: Add catalyst, then continue heating to 170-180℃ and react for 30 minutes. Then add desiccant and dehydrating agent and continue reacting for 3 hours. Step 4: Use a vacuum water pump to create a vacuum. The vacuum level will increase over time. After 15 hours of vacuuming, discharge the product. Dissolve the product in a solvent and then filter it. Step 5: Add alkaline solution until the filtrate is neutral, then wash and separate the liquid three times with distilled water. Step 6: Vacuum drying yields the pure product, fluorinated polyester diol; Step 7: Mix the fluorinated polyester diol and the non-fluorinated polyester diol evenly; Step 8: Add solvent to reduce viscosity, then add hexamethylene diisocyanate trimer as curing agent and stir continuously until fully mixed. Then add catalyst and continue stirring. Step 9: After stirring, pour the mixture into a polytetrafluoroethylene mold and vacuum degas it in an oven at 55-65℃. Then, place it in an oven at 65℃ to continue curing for 10 days.
5. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, The fluorinated diol in step 1 has a molecular weight of 800 g / mol and the following molecular structure: Both m and n are positive integers; The molar ratio of fluorinated diol to phthalic anhydride is 1:
1.
6. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, In step 3, the catalyst is concentrated sulfuric acid with a concentration of 98%, and the amount of concentrated sulfuric acid catalyst used is 6% of the molar amount of phthalic anhydride. The desiccant is anhydrous magnesium sulfate, which is dried in an oven at 200°C. The mass of the anhydrous magnesium sulfate added is 15% of the total mass of the raw materials. The dehydrating agent is xylene, and the mass of xylene added is 25% of the total mass of the raw materials.
7. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, In step 4, the solvent is one or more of ethyl acetate and ethanol.
8. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, In step 5, the alkaline solution is one or more of a saturated potassium bicarbonate solution and a saturated sodium bicarbonate solution.
9. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, In step 7, the mass ratio of fluorinated polyester diol to non-fluorinated polyester diol includes 1:0, 1:1, 3:1, 1:3, and 0:
1.
10. The method for preparing a low-dielectric, highly hydrophobic fluorinated polyester polyurethane according to claim 4, characterized in that, In step 8, the amount of trimer of the curing agent hexamethylene diisocyanate added is 25.85% of the total mass of the diol; The catalyst is dibutyltin dilaurate, and the added mass is % of the total mass. The solvent is ethyl acetate, and the added mass is 50% of the total mass of the diol.