Bio-based polyester / aramid fiber composite paper-based material and preparation method thereof

Abstract

The invention discloses a bio-based polyester / aramid fiber composite paper-based material and a preparation method thereof, relates to the technical field of paper-based materials, and solves the problems that an existing aramid paper-based material product is poor in appearance, mechanical property and insulating property. The aramid fiber composite material comprises the following components in parts by weight: 40-70 parts of aramid chopped fiber, 20-50 parts of aramid fibrid and 10-40 parts of poly (ethylene 2, 5-furandicarboxylate) (PEF) fiber. The length of the aramid chopped fibers is 5-7 mm, and the length of the PEF fibers is 3-6 mm. The composite paper-based material is quantified to be 25-250 g / m < 2 >, and the thickness is 0.04-0.25 mm. Uniformly mixing the aramid chopped fiber pulp, the PEF fiber pulp and the aramid fibrid pulp, and carrying out wet papermaking forming, squeezing and drying to obtain raw paper; and carrying out hot pressing treatment through multiple groups of temperature increasing type preheating rollers, hot pressing rollers and multiple groups of temperature decreasing type heat preservation rollers. The method can be used in the fields of aerospace, rail transit, new energy, national defense and military industry and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of paper-based materials, and in particular to a bio-based polyester / aramid fiber composite paper-based material and a preparation method thereof, and in particular to a polyethylene 2,5-furandicarboxylate (PEF) / aramid fiber composite paper-based material and a preparation method thereof. Background Art

[0002] Aramid paper is a high-performance paper-based material made from aramid fiber through dispersion, wet forming, high-temperature hot pressing and other technologies. This material has a stable chemical structure, excellent mechanical properties, and many outstanding properties such as light weight, high strength, high temperature resistance, flame retardancy, insulation, corrosion resistance, and radiation resistance. Therefore, it is widely used in key fields such as aerospace, rail transportation, new energy, electric power, electronic communications, and national defense. With the rapid development of these fields, the market demand for aramid paper is also growing continuously.

[0003] However, the current localization process of aramid paper faces many challenges. Compared with imported aramid paper, domestic aramid paper has gaps in mechanical properties, gas barrier properties and electrical insulation properties. In order to improve the performance of aramid paper, the industry often composites aramid fiber with petroleum-based polyethylene terephthalate fiber (PET) to obtain aramid composite paper-based materials with better performance.

[0004] In terms of related patent technologies, invention patent CN202410030717.4 discloses a multi-layer composite aramid paper. The aramid paper is provided with a core layer, one side of the core layer is connected to the surface layer by gluing, and a first adhesive layer and a second adhesive layer are provided between the core layer and the bottom layer. This invention adds carbon fiber to the core layer to enhance the strength and rigidity of the paper; the aramid paper of mixed polyester fiber is compositely bonded on both sides of the core layer to improve the light resistance and anti-aging performance, thereby improving the overall performance of the aramid paper and making it more effective.

[0005] Invention patent CN201610601710.9 discloses a method for preparing polyester meta-aramid composite paper. The method first pre-treats PET chopped fibers, then uses a deflaking machine for the first deflaking, then adds meta-aramid pulp fibers for the second deflaking, injects the obtained suspension into a paper former for dehydration and molding, and then obtains polyester fiber aramid composite paper base paper through pressing and drying, and finally hot presses the base paper to obtain polyester aramid composite paper. The preparation method uses the low softening temperature of polyester fiber as a bonding fiber, which effectively improves the strength of meta-aramid paper.

[0006] Invention patent CN200810134636.X discloses an aramid fiber honeycomb core base paper and its preparation method, which uses aramid 1414 fiber, meta-aramid fiber precipitation and polyester fiber to produce aramid honeycomb core base paper. The fiber paper has the advantages of light weight, softness, high specific modulus, high temperature resistance, fatigue resistance, chemical corrosion resistance, low thermal expansion coefficient, moderate permeability, etc. In the production of honeycomb core, it has good effects on resin impregnation and honeycomb node bonding, and the manufactured honeycomb has particularly high plane shear strength and plane compression strength.

[0007] Invention patent CN200410037774.8 discloses a carbon fiber aramid fiber synthetic paper and wet papermaking technology. The synthetic fiber paper uses carbon fiber and aramid fiber as structural fibers, supplemented by polyester or polyphenylene sulfide fiber as bonding fiber. Due to the addition of carbon fiber, it has outstanding performance in heat transfer and electrical conductivity; polyester or polyphenylene sulfide fiber as a binder gives the synthetic fiber paper higher mechanical properties.

[0008] The above patents all adopt the method of mixing aramid fiber and polyester fiber, using modern wet papermaking technology to make paper and hot press molding to make aramid composite paper-based materials. This method can not only give full play to the high strength characteristics of aramid fiber, use the lower softening temperature of polyester fiber as bonding fiber to improve the mechanical strength of aramid composite paper, but also reduce the use of meta-aramid fiber, reduce costs, and improve cost performance. Compared with traditional pure aramid paper-based materials, polyester aramid composite paper has excellent mechanical properties. After being made into honeycomb structure materials, it is widely used in rail transportation and aerospace fields.

[0009] However, in the actual production process, there are some problems when aramid fiber is mixed with petroleum-based polyester fiber (PET) in wet papermaking:

[0010] First, the glass transition temperature of PET polyester fiber is relatively low, only 79°C, which makes it difficult to control the temperature of the drying cylinder during the drying process. If the drying cylinder temperature is too low, the moisture content of the aramid composite base paper is high, the base paper strength is poor, and the papermaking scrap rate is high; if the drying cylinder temperature is too high, the polyester fiber will show a viscous flow property and easily adhere to the drying cylinder, resulting in the polyester aramid composite paper being rough on the cylinder surface and smooth on the back cylinder surface, with a large difference between the two sides, and poor product uniformity and appearance.

[0011] Secondly, PET polyester fiber has poor gas barrier properties, high air permeability, high paper porosity and loose structure, resulting in poor insulation performance, limiting its application in the fields of electrical insulation and lightweighting.

[0012] Third, the thermal properties of PET polyester fiber and aramid fiber are quite different. When subjected to high-temperature hot pressing treatment, due to the large difference in thermal shrinkage rate, uneven wrinkles will occur, affecting the appearance of the product.

[0013] In view of the problems existing in the current pure aramid paper-based materials and PET polyester / aramid composite paper-based materials, how to develop an aramid composite paper-based material with better thermal processing performance, good gas barrier performance, excellent mechanical properties and electrical insulation properties, good appearance and lower overall cost has become an important issue that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0014] In order to solve the above problems existing in the existing aramid paper-based materials, the present invention proposes a bio-based polyester / aramid fiber composite paper-based material and a preparation method thereof.

[0015] The technical solution of the present invention is as follows:

[0016] A bio-based polyester / aramid fiber composite paper-based material, comprising the following components in parts by weight:

[0017] 40-70 parts of aramid short-cut fibers, 20-50 parts of aramid fibrids, and 10-40 parts of polyethylene 2,5-furandicarboxylate fibers;

[0018] Wherein, the length of the aramid chopped fibers is 5 to 7 mm, and the length of the polyethylene 2,5-furandicarboxylate fibers is 3 to 6 mm;

[0019] The basis weight of the bio-based polyester / aramid fiber composite paper-based material is 25 to 250 g / m 2 , thickness is 0.04~0.25mm.

[0020] Preferably, the aramid fibrids are meta-aramid fibrids.

[0021] Preferably, the aramid chopped fibers are meta-aramid chopped fibers or para-aramid chopped fibers.

[0022] The present invention also provides a method for preparing the above-mentioned bio-based polyester / aramid fiber composite paper-based material, comprising the following steps:

[0023] (1) adding aramid chopped fibers into a hydraulic pulper and crushing the fibers to obtain a uniformly dispersed aramid chopped fiber slurry;

[0024] Adding polyethylene 2,5-furandicarboxylate fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry;

[0025] The aramid fibrids are crushed, refined and debonded to obtain aramid fibrid slurry;

[0026] (2) mixing and stirring the aramid short fiber slurry, the PEF fiber slurry and the aramid fibrillation slurry uniformly, and then wet-forming, pressing and drying to obtain a polyester aramid fiber composite paper base paper;

[0027] (3) The composite paper base paper obtained in step (2) is sequentially passed through a plurality of groups of temperature-increasing preheating rollers, hot pressing rollers, and a plurality of groups of temperature-decreasing heat preservation rollers for hot pressing treatment to obtain a polyester-aramid fiber composite paper base material.

[0028] Preferably, the chopped aramid fibers and polyethylene 2,5-furandicarboxylate fibers have a crushing concentration of 0.1% to 0.5%.

[0029] Preferably, the aramid fibrid has a fragmentation concentration of 1.5% to 3.0%, a pulping concentration of 1.0% to 2.0%, and a debonding concentration of 0.3% to 1.0%.

[0030] Preferably, the beating degree of the aramid fibrid slurry is 60-90° SR.

[0031] Preferably, the wet papermaking process adopts any one of a rotary wire paper machine, a fourdrinier wire paper machine and an inclined wire paper machine.

[0032] Preferably, in step (3), the number of the temperature-increasing preheating rollers is 5 to 10 groups, and the temperature difference between adjacent preheating rollers is controlled to be 5 to 20°C; the number of the temperature-decreasing insulation rollers is 5 to 10 groups, and the temperature difference between adjacent insulation rollers is 5 to 20°C.

[0033] Preferably, the hot pressing treatment temperature in step (3) is 200-280° C., the speed is 5-30 m / min, and the pressure is 3-15 MPa.

[0034] Compared with the prior art, the specific beneficial effects of the present invention are:

[0035] 1. The polyester aramid fiber composite paper-based material prepared by the present invention uses polyethylene 2,5-furandicarboxylate (PEF) as a raw material. The glass transition temperature of PEF is greater than 90°C, and it has excellent thermal processing performance, high tensile strength and tensile modulus, and excellent mechanical properties. PEF has excellent gas barrier properties and moisture resistance, with an oxygen permeability of only 1 / 11 of that of PET, a carbon dioxide permeability of 1 / 19 of that of PET, and a water vapor permeability of 1 / 2.8 of that of PET.

[0036] Therefore, compared with traditional pure aramid paper-based materials, PEF is easier to melt-bond in the system, and has both matrix reinforcement and bonding effects, so that the paper-based material provided by the present invention has better mechanical properties and electrical insulation properties, reduces the use of meta-aramid fibers, reduces costs, and has a high cost-effectiveness.

[0037] Compared with traditional petroleum-based polyester-aramid composite paper-based materials, polyethylene 2,5-furandicarboxylate (PEF) has a high glass transition temperature, high mechanical strength, and good gas barrier properties, which makes it have better thermal processing properties, mechanical properties, insulation properties and moisture resistance.

[0038] 2. The present invention uses multiple groups of temperature-increasing preheating rollers for preheating before hot pressing, and multiple groups of temperature-decreasing insulation rollers for insulation after hot pressing. Through temperature design, the polyethylene 2,5-furandicarboxylate (PEF) / aramid fiber composite paper base paper is evenly heated / cooled when entering and leaving the hot pressing process, thereby avoiding wrinkles and deformation caused by sudden temperature changes, thereby ensuring the appearance quality of the product.

[0039] 3. The polyethylene 2,5-furandicarboxylate (PEF) fiber used in the present invention is 100% bio-based fiber with abundant raw material sources. It can be obtained from fructose, galactose, etc. as starting materials. It is also a recyclable polymer, so it can be recycled and reused after the end of its service life, reducing the generation of waste and the impact on the environment, which meets the requirements of sustainable development. DETAILED DESCRIPTION

[0040] In order to make the technical solution of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. It should be noted that the following embodiments are only used to better understand the technical solution of the present invention and should not be understood as limiting the present invention.

[0041] Example 1.

[0042] In this embodiment, a bio-based polyester / aramid fiber composite paper-based material is prepared by the following steps:

[0043] (1) adding 7 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing them to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.3%;

[0044] (2) adding 5 mm polyethylene 2,5-furandicarboxylate (PEF) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry with a crushing concentration of 0.3%;

[0045] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 2.0%, then refined by a double-disc refiner at a refining concentration of 1.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.5%. The obtained aramid fibrid slurry had a beating degree of 82°SR;

[0046] (4) The slurry obtained in step (1), step (2) and step (3) was mixed and stirred uniformly in the ratio of meta-aramid chopped fiber: PEF fiber: meta-aramid fibrid = 50:30:20, and then the mixed slurry was formed by flow conveying on a rotary paper machine, pressed and dried to obtain a 40 g / m 2 Bio-based polyester / aramid fiber composite paper base paper;

[0047] The composite paper base paper obtained in step (4) is passed through 8 groups of preheating rollers in sequence, and the temperature is increased from 100°C to 240°C in sequence, and the temperature difference between adjacent preheating rollers is 20°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 260°C, a pressure of 10 MPa, and a speed of 25 m / min; the paper sample after hot pressing treatment is then passed through 8 groups of insulation rollers in sequence, and the temperature is decreased from 240°C to 100°C in sequence, and the temperature of adjacent insulation rollers is 20°C; after preheating, hot pressing and insulation treatment, a bio-based polyester / aramid fiber composite paper base material is obtained, with a thickness of 0.05 mm.

[0048] Example 2.

[0049] In this example, a bio-based polyester / aramid fiber composite paper-based material was prepared by the following steps:

[0050] (1) adding 6 mm para-aramid chopped fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed para-aramid chopped fiber slurry, wherein the crushing concentration is 0.25%;

[0051] (2) adding 3 mm polyethylene 2,5-furandicarboxylate (PEF) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry with a crushing concentration of 0.3%;

[0052] (3) The meta-aramid fibrid is firstly crushed by a hydraulic pulper at a crushing concentration of 1.5%, then refined by a conical refiner at a refining concentration of 1.2%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 1.0%. The obtained aramid fibrid has a beating degree of 70°SR;

[0053] (4) The slurry obtained in step (1), step (2) and step (3) was mixed and stirred uniformly in the ratio of para-aramid short-cut fiber: PEF fiber: meta-aramid fibril = 50:20:30, and then the mixed slurry was formed by an inclined wire paper machine, pressed and dried to obtain a 40 g / m 2 Bio-based polyester / aramid fiber composite paper base paper;

[0054] The composite paper base paper obtained in step (4) is passed through 9 groups of preheating rollers in sequence, and the temperature is increased from 120°C to 240°C in sequence, and the temperature difference between adjacent preheating rollers is 15°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 260°C, a pressure of 10 MPa, and a speed of 25 m / min; the paper sample after hot pressing treatment is then passed through 9 groups of insulation rollers in sequence, and the temperature is decreased from 240°C to 120°C in sequence, and the temperature of adjacent insulation rollers is 15°C; after preheating, hot pressing and insulation treatment, a bio-based polyester / aramid fiber composite paper base material is obtained, with a thickness of 0.05 mm.

[0055] Example 3.

[0056] In this example, a bio-based polyester / aramid fiber composite paper-based material was prepared by the following steps:

[0057] (1) adding 5 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.3%;

[0058] (2) adding 6 mm polyethylene 2,5-furandicarboxylate (PEF) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry, the crushing concentration of which is 0.3%;

[0059] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 3.0%, then refined by a conical refiner at a refining concentration of 2.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.8%. The obtained aramid fibrid had a beating degree of 64°SR;

[0060] (4) The slurry prepared in step (1), step (2) and step (3) is mixed and stirred uniformly in the ratio of meta-aramid chopped fiber: PEF fiber: meta-aramid fibril = 40:20:40, and then the mixed slurry is formed by flow conveying on a fourdrinier paper machine, pressed and dried to obtain a 40 g / m 2 Bio-based polyester / aramid fiber composite paper base paper;

[0061] The composite paper base paper obtained in step (4) is passed through 10 groups of preheating rollers in sequence, and the temperature is increased from 130°C to 220°C in sequence, and the temperature difference between adjacent preheating rollers is 10°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 240°C, a pressure of 12 MPa, and a speed of 20 m / min; the paper sample after hot pressing treatment is then passed through 10 groups of insulation rollers in sequence, and the temperature is decreased from 220°C to 130°C in sequence, and the temperature of adjacent insulation rollers is 10°C; after preheating, hot pressing and insulation treatment, a bio-based polyester / aramid fiber composite paper base material is obtained, with a thickness of 0.05 mm.

[0062] Example 4.

[0063] In this embodiment, a bio-based polyester / aramid fiber composite material is prepared by the following steps:

[0064] (1) adding 7 mm meta-aramid chopped fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.1%;

[0065] (2) adding 6 mm polyethylene 2,5-furandicarboxylate (PEF) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry, the crushing concentration of which is 0.1%;

[0066] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 1.5%, then refined by a double-disc refiner at a refining concentration of 1.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.3%. The obtained aramid fibrid slurry had a beating degree of 87°SR;

[0067] (4) The slurry prepared in step (1), step (2) and step (3) was mixed and stirred uniformly in the ratio of meta-aramid chopped fiber: PEF fiber: meta-aramid fibrid = 40:40:20, and then the mixed slurry was formed by flow conveying on a rotary paper machine, pressed and dried to obtain a 25 g / m 2 Bio-based polyester / aramid fiber composite paper base paper;

[0068] The composite paper base paper obtained in step (4) is passed through 5 groups of preheating rollers in sequence, and the temperature is increased from 100°C to 180°C in sequence, and the temperature difference between adjacent preheating rollers is 20°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 200°C, a pressure of 5 MPa, and a speed of 20 m / min; the paper sample after hot pressing treatment is then passed through 5 groups of insulation rollers in sequence, and the temperature is decreased from 180°C to 100°C in sequence, and the temperature of adjacent insulation rollers is 20°C; after preheating, hot pressing and insulation treatment, a bio-based polyester / aramid fiber composite paper base material is obtained, with a thickness of 0.04 mm.

[0069] Example 5.

[0070] In this embodiment, a bio-based polyester / aramid fiber composite paper-based material is prepared by the following steps:

[0071] (1) adding 6 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.4%;

[0072] (2) adding 6 mm polyethylene 2,5-furandicarboxylate (PEF) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry at a crushing concentration of 0.5%;

[0073] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 3.0%, then refined by a conical refiner at a refining concentration of 2.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.8%. The obtained aramid fibrid had a beating degree of 64°SR;

[0074] (4) The slurry prepared in step (1), step (2) and step (3) was mixed and stirred uniformly in the ratio of meta-aramid chopped fiber: PEF fiber: meta-aramid fibril = 50:30:20, and then the mixed slurry was formed by flow conveying on a fourdrinier paper machine, pressed and dried to obtain a 250 g / m 2 Bio-based polyester / aramid fiber composite paper base paper;

[0075] The composite paper base paper obtained in step (4) is passed through 10 groups of preheating rollers in sequence, and the temperature is increased from 180°C to 270°C in sequence, and the temperature difference between adjacent preheating rollers is 10°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 280°C, a pressure of 15 MPa, and a speed of 5 m / min; the paper sample after hot pressing treatment is then passed through 10 groups of insulation rollers in sequence, and the temperature is decreased from 270°C to 180°C in sequence, and the temperature of adjacent insulation rollers is 10°C; after preheating, hot pressing and insulation treatment, a bio-based polyester / aramid fiber composite paper base material is obtained, with a thickness of 0.25 mm.

[0076] Comparative Example 1.

[0077] The meta-aramid paper-based material was prepared by the following steps:

[0078] (1) adding 7 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing them to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.3%;

[0079] (2) The meta-aramid fibrid is firstly crushed by a hydraulic pulper at a crushing concentration of 1.5%, then refined by a conical refiner at a refining concentration of 1.2%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 1.0%. The obtained aramid fibrid has a beating degree of 70°SR;

[0080] (3) The slurry prepared in step (1) and step (2) was mixed and stirred evenly in a ratio of 50:50, and then the mixed slurry was formed by an inclined wire paper machine, pressed, and dried to obtain a paper with a basis weight of 40 g / m 2 Pure meta-aramid base paper;

[0081] The pure meta-aramid base paper obtained in step (3) is hot pressed at a temperature of 300° C., a pressure of 10 MPa, and a speed of 25 m / min to obtain a pure meta-aramid paper-based material with a thickness of 0.05 mm.

[0082] Comparative Example 2.

[0083] The para-aramid paper-based material was prepared by the following steps:

[0084] (1) adding 6 mm para-aramid chopped fibers into a hydraulic pulper, and crushing them to obtain a uniformly dispersed para-aramid chopped fiber slurry, wherein the crushing concentration is 0.25%;

[0085] (2) The meta-aramid fibrid is firstly crushed by a hydraulic pulper at a crushing concentration of 1.5%, then refined by a conical refiner at a refining concentration of 1.2%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 1.0%. The obtained aramid fibrid has a beating degree of 70°SR;

[0086] (3) The slurry prepared in step (1) and step (2) was mixed and stirred evenly in a ratio of 50:50, and then the mixed slurry was formed by an inclined wire paper machine, pressed, and dried to obtain a paper with a basis weight of 40 g / m 2 Para-aramid base paper;

[0087] The pure meta-aramid base paper obtained in step (3) is hot pressed at a temperature of 300° C., a pressure of 10 MPa, and a speed of 25 m / min to obtain a para-aramid paper-based material with a thickness of 0.05 mm.

[0088] Comparative Example 3.

[0089] In this embodiment, a polyethylene terephthalate (PET) / aramid fiber composite paper-based material is prepared by the following steps, including the following steps:

[0090] (1) adding 7 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing them to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.3%;

[0091] (2) adding 5 mm polyethylene terephthalate (PET) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PET fiber slurry, the crushing concentration of which is 0.3%;

[0092] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 2.0%, then refined by a double-disc refiner at a refining concentration of 1.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.5%. The obtained aramid fibrid had a beating degree of 82°SR;

[0093] (4) The slurries prepared in step (1), step (2) and step (3) were mixed and stirred in the ratio of 50:30:20 for the meta-aramid chopped fibers:PET fibers:meta-aramid fibrids, and then the mixed slurry was formed by a rotary paper machine, pressed and dried to obtain a 40 g / m 2 Polyethylene terephthalate (PET) / aramid fiber composite paper base paper;

[0094] (5) The composite paper base obtained in step (4) is directly hot-pressed at a temperature of 260° C., a pressure of 10 MPa, and a speed of 25 m / min to obtain a polyethylene terephthalate (PET) / aramid fiber composite paper base material with a thickness of 0.05 mm.

[0095] The paper-based material described in Comparative Example 3 has not been subjected to temperature-increasing preheating and temperature-decreasing insulation treatment.

[0096] Comparative Example 4.

[0097] In this embodiment, a polyethylene terephthalate (PET) / aramid fiber composite paper-based material is prepared by the following steps:

[0098] (1) adding 7 mm meta-aramid chopped fibers into a hydraulic pulper, and crushing them to obtain a uniformly dispersed meta-aramid chopped fiber slurry, wherein the crushing concentration is 0.3%;

[0099] (2) adding 5 mm polyethylene terephthalate (PET) fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PET fiber slurry, the crushing concentration of which is 0.3%;

[0100] (3) The meta-aramid fibrid was firstly crushed by a hydraulic pulper at a crushing concentration of 2.0%, then refined by a double-disc refiner at a refining concentration of 1.0%, and then deflaked by a high-frequency deflaker at a deflaking concentration of 0.5%. The obtained aramid fibrid had a beating degree of 82°SR;

[0101] (4) The slurries prepared in step (1), step (2) and step (3) were mixed and stirred in the ratio of 50:30:20 for the meta-aramid chopped fibers:PET fibers:meta-aramid fibrids, and then the mixed slurry was formed by a rotary paper machine, pressed and dried to obtain a 40 g / m 2 Polyethylene terephthalate (PET) / aramid fiber composite paper base paper;

[0102] (5) The composite paper base obtained in step (4) is passed through 8 groups of preheating rollers in sequence, and the temperature is increased from 100°C to 240°C in sequence, and the temperature difference between adjacent preheating rollers is 20°C; the preheated composite base paper is hot pressed under the conditions of a hot pressing temperature of 260°C, a pressure of 10 MPa, and a speed of 25 m / min; the paper sample after hot pressing is then passed through 8 groups of insulation rollers in sequence, and the temperature is decreased from 240°C to 100°C in sequence, and the temperature of adjacent insulation rollers is 20°C; after preheating, hot pressing and insulation treatment, a polyethylene terephthalate (PET) / aramid fiber composite paper base material with a thickness of 0.05 mm is obtained.

[0103] The paper-based material described in Comparative Example 4 was subjected to temperature-increasing preheating and temperature-decreasing insulation treatment.

[0104] Effect example.

[0105] The properties of the paper-based materials prepared in Examples 1-5 and Comparative Examples 1-4 and the imported aramid paper samples were tested, and the test items and test methods are as follows:

[0106] (1) Thickness is measured in accordance with GB / T 451.3-2002 “Determination of thickness of paper and paperboard”.

[0107] (2) The quantitative test shall be carried out in accordance with GB / T 451.2-2023 “Paper and paperboard - Part 2: Determination of quantitative properties”.

[0108] (3) The tensile strength is tested in accordance with GB / T 20629.2-2013 “Non-cellulose paper for electrical use Part 2: Test methods”.

[0109] (4) The electrical strength shall be tested in accordance with GB / T 1408.1-2016 "Electrical strength test methods of insulating materials Part 1: Tests at power frequency".

[0110] (5) The air permeability was tested according to the Schober method in GB / T 458-2008 “Determination of air permeability of paper and paperboard”.

[0111] (6) Water immersion voltage retention rate: After immersion in water for 24 hours, the breakdown voltage is tested in accordance with GB / T 1408.1-2016 "Electrical strength test methods for insulating materials Part 1: Tests at power frequency" and the retention rate is calculated.

[0112] The test results are shown in the following table:

[0113]

[0114]

[0115] It can be seen from the performance data in the table that the bio-based polyester / aramid fiber composite paper-based material prepared by the present invention, namely polyethylene 2,5-furandicarboxylate (PEF) / aramid fiber composite paper-based material, has more excellent mechanical properties, electrical insulation properties, gas barrier properties and moisture resistance properties compared to pure aramid paper-based materials, polyethylene terephthalate (PET) / aramid fiber composite paper-based materials and imported aramid paper. Combined with the characteristics of bio-based PEF materials such as wide sources of raw materials, low cost, environmental protection and easy recycling, it is expected to gradually replace petroleum-based PET modified aramid paper-based materials and pure aramid paper-based materials, and achieve large-scale application in the fields of electrical insulation and lightweight.

[0116] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A bio-based polyester / aramid fiber composite paper-based material, characterized in that: Contains the following components by mass: 40-70 parts of aramid short-cut fibers, 20-50 parts of aramid fibrids, and 10-40 parts of polyethylene 2,5-furandicarboxylate fibers; Wherein, the length of the aramid chopped fibers is 5 to 7 mm, and the length of the polyethylene 2,5-furandicarboxylate fibers is 3 to 6 mm; The basis weight of the bio-based polyester / aramid fiber composite paper-based material is 25 to 250 g / m 2 , thickness is 0.04~0.25mm.

2. The bio-based polyester / aramid fiber composite paper-based material according to claim 1, characterized in that: The aramid fibrid is meta-aramid fibrid.

3. The bio-based polyester / aramid fiber composite paper-based material according to claim 1, characterized in that: The aramid short fibers are meta-aramid short fibers or para-aramid short fibers.

4. A method for preparing a bio-based polyester / aramid fiber composite paper-based material according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) adding aramid chopped fibers into a hydraulic pulper and crushing the fibers to obtain a uniformly dispersed aramid chopped fiber slurry; Adding polyethylene 2,5-furandicarboxylate fibers into a hydraulic pulper and crushing them to obtain a uniformly dispersed PEF fiber slurry; The aramid fibrids are crushed, refined and debonded to obtain aramid fibrid slurry; (2) mixing and stirring the aramid short fiber slurry, the PEF fiber slurry and the aramid fibrillation slurry uniformly, and then wet-forming, pressing and drying to obtain a polyester aramid fiber composite paper base paper; (3) The composite paper base paper obtained in step (2) is sequentially passed through a plurality of groups of temperature-increasing preheating rollers, hot pressing rollers, and a plurality of groups of temperature-decreasing heat preservation rollers for hot pressing treatment to obtain a polyester-aramid fiber composite paper base material.

5. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: The chopped aramid fibers and polyethylene 2,5-furandicarboxylate fibers have a crushing concentration of 0.1% to 0.5%.

6. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: The aramid fibrid has a disintegration concentration of 1.5% to 3.0%, a pulping concentration of 1.0% to 2.0%, and a debonding concentration of 0.3% to 1.0%.

7. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: The beating degree of the aramid fibrid slurry is 60-90°SR.

8. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: The wet papermaking process adopts any one of a rotary mesh paper machine, a fourdrinier mesh paper machine and an inclined mesh paper machine.

9. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: In step (3), the number of the temperature-increasing preheating rollers is 5 to 10 groups, and the temperature difference between adjacent preheating rollers is controlled to be 5 to 20°C; the number of the temperature-decreasing insulation rollers is 5 to 10 groups, and the temperature difference between adjacent insulation rollers is 5 to 20°C.

10. The method for preparing the bio-based polyester / aramid fiber composite paper-based material according to claim 4, characterized in that: The hot pressing treatment temperature in step (3) is 200-280° C., the speed is 5-30 m / min, and the pressure is 3-15 MPa.

Images