A polypropylene composite material, its preparation method and application

Abstract

This invention discloses a polypropylene composite material, its preparation method, and its application. The raw materials for preparing the polypropylene composite material include a polymer component, which includes polypropylene and a functionalized phenyl-grafted thiophene polymer material. The functionalized phenyl-grafted thiophene polymer material includes a functionalized phenyl-grafted thiophene polymer, and the structural formula of the functionalized phenyl-grafted thiophene polymer is shown in Formula (I): Formula (I). By adding a functionalized phenyl-grafted thiophene polymer material to polypropylene, this invention can significantly improve the high-temperature resistance of the BOPP capacitor film prepared from the polypropylene composite material, and thus significantly improve the high-temperature resistance of the thin-film capacitor prepared from the BOPP capacitor film.

Description

Technical Field

[0001] This invention belongs to the field of polypropylene composite material technology, and particularly relates to a polypropylene composite material, its preparation method and application. Background Technology

[0002] Film capacitors are essential basic electronic components, widely used in electronics, home appliances, communications, power, and other industries. Polypropylene composites, especially biaxially oriented polypropylene (BOPP) films, have become key dielectric materials for metallized film capacitors in power electronics and new energy vehicles due to their low dielectric loss factor and high dielectric strength. However, existing biaxially oriented polypropylene films have poor high-temperature resistance; the long-term operating temperature of conventional BOPP capacitor films typically does not exceed 105℃. The problems of electrical performance degradation, accelerated thermal aging, and shortened lifespan under sustained high temperatures (such as 125℃ and above) or high-temperature, high-field-strength coupling stress are becoming increasingly prominent, becoming a key technical bottleneck restricting the performance and reliability of high-end power electronic equipment.

[0003] In existing technologies, the heat resistance of polypropylene films, and consequently the heat resistance of polypropylene film capacitors, is often improved by adding cyclic olefin copolymers or inorganic particles. However, while cyclic olefin copolymers have good compatibility with polypropylene and do not degrade the dielectric properties of the film, their effect on temperature resistance is limited in small amounts, and large amounts significantly reduce the film-forming properties. As for adding inorganic ions, on the one hand, the high polarity of inorganic particles leads to poor dispersibility in low-polarity polypropylene, affecting the mechanical properties of the film; on the other hand, the significant difference in dielectric constant between inorganic particles and polypropylene greatly increases the dielectric loss of the film, severely impacting its dielectric properties. Therefore, neither existing methods of adding cyclic olefin copolymers or inorganic particles can significantly improve the high-temperature resistance of film capacitors.

[0004] Therefore, how to significantly improve the high-temperature resistance of film capacitors is an urgent problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of the prior art, a polypropylene composite material is provided. By adding functionalized phenyl-grafted thiophene polymer material to polypropylene, the high-temperature resistance of BOPP capacitor film prepared from the polypropylene composite material can be significantly improved, thereby significantly improving the high-temperature resistance of film capacitors prepared from BOPP capacitor film.

[0006] The purpose of this invention is to provide a polypropylene composite material, the raw materials of which include a polymer component, wherein the polymer component includes polypropylene and a functionalized phenyl-grafted thiophene polymer material, wherein the functionalized phenyl-grafted thiophene polymer material includes a functionalized phenyl-grafted thiophene polymer, and the structural formula of the functionalized phenyl-grafted thiophene polymer is shown in formula (I):

[0007] Equation (Ⅰ);

[0008] Wherein, R is cyano or formyl; the number average molecular weight is 11~18.5 kDa, and the molecular weight distribution index (PDI) is 2.0~3.0.

[0009] In some embodiments of the present invention, the amount of the functionalized phenyl-grafted thiophene polymer material is 0.1 to 3% of the polymer component by mass percentage.

[0010] In some embodiments of the present invention, the amount of the functionalized phenyl-grafted thiophene polymer material is 0.5 to 3% of the polymer component by mass percentage.

[0011] In some embodiments of the present invention, the grafting rate of functionalized phenyl groups in the functionalized phenyl-grafted thiophene polymer material is 1.0~12 mol%. It should be understood that the grafting rate of functionalized phenyl groups refers to the percentage of functionalized phenyl groups in the functionalized phenyl-grafted thiophene polymer material. The percentage of repeating structural units relative to the total amount of repeating structural units in a functionalized phenyl-grafted thiophene polymer material.

[0012] In some embodiments of the present invention, the grafting rate of the functionalized phenyl group in the functionalized phenyl-grafted thiophene polymer material is 1.4 to 1.7 mol.

[0013] In some embodiments of the present invention, the raw materials for preparing the functionalized phenyl-grafted thiophene polymer material include poly-3-hexylthiophene and substituted bromobenzene. , where R is a cyano or formyl group.

[0014] In some embodiments of the present invention, the preparation method of the functionalized phenyl-grafted thiophene polymer material includes the following steps: under the presence of a catalyst and an auxiliary agent, the poly-3-hexylthiophene reacts with the substituted bromobenzene. The reaction yields the functionalized phenyl-grafted thiophene polymer material.

[0015] In some embodiments of the present invention, the catalyst is selected from palladium chloride.

[0016] In some embodiments of the present invention, the adjuvant includes an organophosphorus ligand, an inorganic base, an organic acid, and a first solvent.

[0017] In some embodiments of the present invention, the organophosphorus ligand comprises triphenylphosphine.

[0018] In some embodiments of the present invention, the inorganic base includes potassium carbonate.

[0019] In some embodiments of the present invention, the organic acid includes tervastatin.

[0020] In some embodiments of the present invention, the first solvent includes toluene.

[0021] In some embodiments of the present invention, the molar ratio of poly(3-hexylthiophene) to substituted bromobenzene is 1:0.05~0.15.

[0022] In some embodiments of the present invention, the molar ratio of the poly(3-hexylthiophene) to the catalyst is 1:0.0005~0.002.

[0023] In some embodiments of the present invention, the molar ratio of the poly(3-hexylthiophene) to the organophosphorus ligand is 1:0.001~0.003.

[0024] In some embodiments of the present invention, the molar ratio of the poly(3-hexylthiophene) to the inorganic base is 1:0.1~0.3.

[0025] In some embodiments of the present invention, the molar ratio of the poly(3-hexylthiophene) to the organic acid is 1:0.01~0.05.

[0026] In some embodiments of the present invention, the reaction temperature is 80~120°C and the time is 18~30 hours.

[0027] In some embodiments of the present invention, the amount of polypropylene used is 97% to 99.9% of the polymer component, preferably 97% to 99.5%, by mass percentage.

[0028] In some embodiments of the present invention, the polypropylene is partially crystalline polypropylene, preferably, the crystallinity of the polypropylene is 30-80%, more preferably 50-80%.

[0029] In some embodiments of the present invention, the melt index of the polypropylene at 230°C / 2.16kg is 1~5 g / 10min, preferably 2~4 g / 10min.

[0030] In some embodiments of the present invention, the raw materials for preparation also include other additives.

[0031] In some embodiments of the present invention, the other additives are selected from at least one of plasticizers, light stabilizers, colorants, preservatives, antioxidants, antistatic agents, flame retardants, and reinforcing agents.

[0032] In some embodiments of the present invention, the amount of the other additives is 0 to 5% of the composite material by mass percentage.

[0033] In some embodiments of the present invention, the crystallinity of the polypropylene composite material is ≥45%;

[0034] In some embodiments of the present invention, the ash content of the polypropylene composite material is ≤20ppm.

[0035] Another object of the present invention is to provide a method for preparing the polypropylene composite material, which includes the following steps:

[0036] S1. The functionalized phenyl-grafted thiophene polymer material is mixed with a portion of polypropylene and heated to dissolve in an organic solvent. Then, a poor solvent is added to precipitate the precipitate. The precipitate is extruded and granulated to obtain thiophene polymer material masterbatch.

[0037] S2. The thiophene polymer masterbatch is blended with the remaining polypropylene and optionally the other additives, and then melt-extruded to obtain the polypropylene composite material.

[0038] In some embodiments of the present invention, the mass ratio of the functionalized phenyl-grafted thiophene polymer material in S1 to the polypropylene in the portion is 1:5 to 15.

[0039] In some embodiments of the present invention, the organic solvent in S1 is selected from toluene.

[0040] In some embodiments of the present invention, the heating temperature in S1 is 100~180°C.

[0041] In some embodiments of the present invention, the undesirable solvent mentioned in S2 is selected from at least one of methanol and ethanol.

[0042] In some embodiments of the present invention, the temperature of the melt extrusion in S2 is 220-260°C.

[0043] Another objective of this invention is to provide the application of the above-mentioned polypropylene composite material or the polypropylene composite material prepared by the above-mentioned preparation method in the preparation of BOPP capacitor film.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This invention improves the high-temperature resistance of film capacitors by adding a functionalized phenyl-grafted thiophene polymer material to polypropylene. This functionalized phenyl-grafted thiophene polymer material has good compatibility with polypropylene and can improve the high-temperature resistance of polypropylene composite materials. Attached Figure Description

[0046] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings:

[0047] Figure 1 The 1H NMR spectrum of the functionalized phenyl-grafted thiophene polymer material prepared in Example 1.

[0048] Figure 2 The 1H NMR spectrum of the functionalized phenyl-grafted thiophene polymer material prepared in Example 2. Detailed Implementation

[0049] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0050] All raw materials used in this invention are commercially available.

[0051] In the specific embodiments of the present invention, the commercially available polypropylene used is PPH-FC03, and the commercially available COC used is Topas 6013.

[0052] The structure of the commercially available poly-3-hexylthiophene used in the specific embodiments of the present invention is as follows:

[0053] .

[0054] Preparation Example 1

[0055] This preparation example provides a functionalized phenyl-grafted thiophene polymer material, the preparation method of which includes the following steps:

[0056] Under a nitrogen atmosphere, commercially available poly(3-hexylthiophene b) (1.0 mmol), 4-bromobenzonitrile (0.1 mmol), potassium carbonate (0.2 mmol), palladium chloride (0.001 mmol), triphenylphosphine (0.002 mmol), tervaponic acid (0.03 mmol), and toluene (10 mL) were reacted at 100 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, the polymer was precipitated with methanol, and the polymer was washed several times with ultrapure water and n-hexane. After drying, functionalized phenyl-grafted thiophene polymer material was obtained. The yield was 80%; the number-average molecular weight (Mn) was 17.7 kDa, and the PDI was 2.6; the benzonitrile grafted segments accounted for 1.4% of the molar percentage of the functionalized phenyl-grafted thiophene polymer material, i.e., the grafting rate was 1.4 mol%; the functionalized phenyl-grafted thiophene polymer material comprised a benzonitrile-grafted thiophene polymer and poly-3-hexylthiophene without unreacted grafting reaction, and the structure of the benzonitrile-grafted thiophene polymer is shown below:

[0057] .

[0058] Preparation Example 2

[0059] This preparation example provides a functionalized phenyl-grafted thiophene polymer material, the preparation method of which includes the following steps:

[0060] Under a nitrogen atmosphere, commercially available poly(3-hexylthiophene b) (1.0 mmol), 4-bromobenzaldehyde (0.1 mmol), potassium carbonate (0.2 mmol), palladium chloride (0.001 mmol), triphenylphosphine (0.002 mmol), tervaponic acid (0.03 mmol), and toluene (10 mL) were reacted at 100 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, the polymer was precipitated with methanol, and the polymer was washed several times with ultrapure water and n-hexane. After drying, functionalized phenyl-grafted thiophene polymer material was obtained. The yield was 88%; the number-average molecular weight (Mn) was 18.1 kDa, and the PDI was 2.6; the benzaldehyde-grafted segments accounted for 1.7% of the molar percentage of the functionalized phenyl-grafted thiophene polymer material, i.e., the grafting rate was 1.7 mol%; the functionalized phenyl-grafted thiophene polymer material comprised a benzaldehyde-grafted thiophene polymer and poly-3-hexylthiophene without unreacted grafting reaction, and the structure of the benzaldehyde-grafted thiophene polymer is shown below:

[0061] .

[0062] Preparation Example 3

[0063] This preparation example provides a functionalized phenyl-grafted thiophene polymer material, the preparation method of which includes the following steps:

[0064] Under a nitrogen atmosphere, commercially available poly(3-hexylthiophene a) (1.0 mmol), 4-bromobenzonitrile (0.08 mmol), potassium carbonate (0.1 mmol), palladium chloride (0.0015 mmol), triphenylphosphine (0.0025 mmol), tervaponic acid (0.02 mmol), and toluene (10 mL) were reacted at 100 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, the polymer was precipitated with methanol, and the polymer was washed several times with ultrapure water and n-hexane. After drying, functionalized phenyl-grafted thiophene polymer material was obtained. The yield was 83%; the number-average molecular weight (Mn) was 11.0 kDa, and the PDI was 2.0; the benzonitrile grafted segments accounted for 1.0% of the molar percentage of the functionalized phenyl-grafted thiophene polymer material, i.e., the grafting rate was 1.0 mol%; the functionalized phenyl-grafted thiophene polymer material comprised a benzonitrile-grafted thiophene polymer and poly-3-hexylthiophene without unreacted grafting reaction, and the structure of the benzonitrile-grafted thiophene polymer is shown below:

[0065] .

[0066] Preparation Example 4

[0067] This preparation example provides a functionalized phenyl-grafted thiophene polymer material, the preparation method of which includes the following steps:

[0068] Under a nitrogen atmosphere, commercially available poly(3-hexylthiophene) C (1.0 mmol), 4-bromobenzaldehyde (0.9 mmol), potassium carbonate (0.2 mmol), palladium chloride (0.002 mmol), triphenylphosphine (0.001 mmol), tervaponic acid (0.05 mmol), and toluene (10 mL) were reacted at 100 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, the polymer was precipitated with methanol, and the polymer was washed several times with ultrapure water and n-hexane. After drying, functionalized phenyl-grafted thiophene polymer material was obtained. The yield was 86%; the number-average molecular weight (Mn) was 17.5 kDa, and the PDI was 2.8; the benzaldehyde-grafted segments accounted for 12% of the molar percentage of the functionalized phenyl-grafted thiophene polymer material, i.e., the grafting rate was 12 mol%; the functionalized phenyl-grafted thiophene polymer material contained benzaldehyde-grafted thiophene polymer and poly-3-hexylthiophene without unreacted grafting reaction, and the structure of the benzaldehyde-grafted thiophene polymer is shown below:

[0069] .

[0070] Example 1

[0071] This embodiment provides a polypropylene composite material, which is prepared by the following steps, based on parts by mass:

[0072] S1. Mix 0.5 parts by mass of the functionalized phenyl-grafted thiophene polymer material prepared in Preparation Example 1 with 5 parts by mass of polypropylene powder, heat to 120~160℃ and dissolve in toluene, then add 25L of ethanol, precipitate, and extrude the precipitate into granules to obtain thiophene polymer material masterbatch.

[0073] S2. The above-mentioned thiophene polymer material masterbatch is blended with 94.5 parts by weight of polypropylene powder, added to an extrusion device, and the temperature of the feeding section of the extrusion device is controlled at 235~245℃, the temperature of the melting section is 250~265℃, and the temperature of the homogenization section is 250~260℃. The composite material is then extruded.

[0074] Example 2

[0075] This embodiment provides a polypropylene composite material, which differs from Example 1 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 2". Everything else remains the same as in Example 1.

[0076] Example 3

[0077] This embodiment provides a polypropylene composite material, which differs from Example 1 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 3". Everything else remains the same as in Example 1.

[0078] Example 4

[0079] This embodiment provides a polypropylene composite material, which differs from Example 1 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 4". Everything else remains the same as in Example 1.

[0080] Example 5

[0081] This embodiment provides a polypropylene composite material, which is prepared by the following steps, based on parts by mass:

[0082] S1. Mix 3 parts by mass of the functionalized phenyl-grafted thiophene polymer material prepared in Preparation Example 1 with 30 parts by mass of polypropylene powder, heat to 120~160℃ and dissolve in toluene, then add 150L of ethanol, precipitate, and extrude the precipitate into granules to obtain thiophene polymer material masterbatch.

[0083] S2. The above-mentioned thiophene polymer material masterbatch is blended with 67 parts by mass of polypropylene powder, added to an extrusion device, and the temperature of the feeding section of the extrusion device is controlled at 235~245℃, the temperature of the melting section is 250~265℃, and the temperature of the homogenization section is 250~260℃, and the composite material is extruded.

[0084] Example 6

[0085] This embodiment provides a polypropylene composite material, which differs from Example 5 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 2". Everything else remains the same as Example 5.

[0086] Example 7

[0087] This embodiment provides a polypropylene composite material, which differs from Example 5 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 3". Everything else remains the same as Example 5.

[0088] Example 8

[0089] This embodiment provides a polypropylene composite material, which differs from Example 5 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "the functionalized phenyl-grafted thiophene polymer material prepared in Example 4". Everything else remains the same as Example 5.

[0090] Comparative Example 1

[0091] This comparative example provides a polypropylene composite material, which differs from Example 1 only in that "the functionalized phenyl-grafted thiophene polymer material prepared in Example 1" in S1 is replaced with "COC (topas 6013)". Everything else remains the same as in Example 1.

[0092] Application Example 1

[0093] This application example provides a BOPP capacitor film, the preparation method of which includes the following steps:

[0094] The polypropylene composite material obtained in Example 1 was added to a twin-screw extruder with an aspect ratio of 40:1 to process it into a uniform melt. The melt was then extruded and cast through a die to prepare a thin film. The die temperature was 230°C. The thin film was then subjected to biaxial stretching: longitudinal stretching: preheating at 143°C, stretching at 138°C, and setting at 143°C; transverse stretching: preheating at 165°C, stretching at 159°C, and setting at 167°C. After corona treatment with a strength of 43 mN / m, the film was wound up to obtain a BOPP capacitor film with a thickness of 5.5 μm.

[0095] Application Examples 2-8 and Comparative Application Example 1

[0096] This application example and the comparative application example provide a BOPP capacitor film, which differs from Application Example 1 only in that "the polypropylene composite material obtained in Example 1" is replaced with the polypropylene composite materials obtained in Examples 2-8 and Comparative Example 1, respectively. Everything else is the same as Application Example 1.

[0097] The BOPP capacitor films obtained from Application Examples 1 to 8 and Comparative Application Example 1 were respectively subjected to coating, winding, static pressing, heat setting, gold sputtering, and encapsulation to obtain film capacitors TFC1 to TFC9 in sequence; the following performance tests were performed on film capacitors TFC1 to TFC9, and the results are shown in Table 1.

[0098] Capacitance change rate test: The initial capacitance value was tested by connecting the two electrodes of film capacitors TFC1~TFC9 to a power supply respectively. Then, film capacitors TFC1~TFC9 were placed in a 125°C constant temperature oven with an applied DC voltage of 1100V. The capacitance value was measured after different hours of operation in the oven, and the final capacitance value was measured after 1000 hours. Three sets of experiments were conducted, and the average value was used to calculate the capacitance change rate. A capacitance change exceeding -5.0% indicates that the capacitor has failed.

[0099] Table 1: Test results of capacitance change rate of film capacitors TFC1~TFC9

[0100]

[0101] As shown in Table 1, the capacitor films prepared from the polypropylene composite materials obtained in Examples 1-8 of this invention, and the resulting thin-film capacitors TFC1-TFC8, exhibit excellent high-temperature resistance.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.

Claims

1. A polypropylene composite, characterized in that, The raw materials for preparation include polymer components, which include polypropylene and functionalized phenyl-grafted thiophene polymer materials. The functionalized phenyl-grafted thiophene polymer materials include functionalized phenyl-grafted thiophene polymers, and the structural formula of the functionalized phenyl-grafted thiophene polymer is shown in formula (Ⅰ). Formula (I); Wherein, R is cyano or formyl; the number-average molecular weight is 11~18.5 kDa, and the molecular weight distribution index (PDI) is 2.0~3.0; The amount of the functionalized phenyl-grafted thiophene polymer material, by mass percentage, is 0.1% to 3% of the polymer component; The amount of polypropylene used, by mass percentage, is 97% to 99.5% of the polymer component; The grafting rate of the functionalized phenyl-grafted thiophene polymer material is 1.0~12 mol.

2. The polypropylene composite of claim 1, wherein, The amount of the functionalized phenyl-grafted thiophene polymer material is 0.5 to 3% of the polymer component by mass percentage.

3. The polypropylene composite of claim 1, wherein the polypropylene is a homopolymer of propylene. The grafting rate of the functionalized phenyl-grafted thiophene polymer material is 1.4~1.7 mol.

4. The polypropylene composite material as described in claim 1, characterized in that, The raw materials used in the preparation also include other additives.

5. The polypropylene composite material as described in claim 4, characterized in that, The other additives are selected from at least one of plasticizers, light stabilizers, colorants, preservatives, antioxidants, antistatic agents, flame retardants, and reinforcing agents.

6. The method for preparing the polypropylene composite material according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. The functionalized phenyl-grafted thiophene polymer material is mixed with a portion of polypropylene and heated to dissolve in an organic solvent. Then, a poor solvent is added to precipitate the precipitate. The precipitate is extruded and granulated to obtain thiophene polymer material masterbatch. S2. The thiophene polymer masterbatch is blended with the remaining polypropylene and optional other additives, and then melt-extruded to obtain the polypropylene composite material.

7. The application of the polypropylene composite material according to any one of claims 1 to 5 or the polypropylene composite material prepared by the preparation method according to claim 6 in the preparation of BOPP capacitor film.

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