Wholly aromatic ether ketone resin powder and production method thereof, and porous molded body and production method thereof

Abstract

To provide: wholly aromatic ether ketone resin powder capable of molding a porous molded body having high strength; and the porous molded body.SOLUTION: Provided are: wholly aromatic ether ketone resin powder of which the median diameter (D50) is 5-100 μm and the difference between the melting point Tm1 and the crystallization temperature Tc (Tm1-Tc) measured by a differential scan calorimeter is 55°C or more; and a porous molded body formed by molding the wholly aromatic ether ketone resin powder of which the porosity is 20-60%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a wholly aromatic ether ketone resin powder and a method for producing the same, and a porous molded body and a method for producing the same. [Background technology]

[0002] Porous molded bodies made by molding resin powder are formed by heat-treating and solidifying the resin powder in a porous state, leaving voids at the interfaces where the powder particles overlap. Such porous molded bodies are used in a variety of applications, including filters, sound-absorbing materials, impregnation materials, coating materials, medical-related parts, information-related parts, and electronics parts. However, there are few examples of porous engineering plastics, and the only materials on the market are polytetrafluoroethylene (PTFE), polyetherketoneketone (PEKK), polyetheretherketone (PEEK), etc. While porous PEKK and PEEK bodies are commercially available, they have a narrow molding window (the moldable resin temperature range) and are difficult to mold. Therefore, while two-dimensional plate-like objects can be molded, molding three-dimensional porous bodies has been difficult.

[0003] Meanwhile, Patent Document 1 discloses a method for producing polyaryletherketone (PAEK) powder. However, this polyaryletherketone (PAEK) powder is used in a method for producing a layered three-dimensional object, and is not used to produce a porous polyaryletherketone (PAEK) body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-523364 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned conventional problems, and an object of the present invention is to provide a wholly aromatic ether ketone resin powder capable of molding a porous molded body having high strength and a method for producing the same, as well as a porous molded body having high strength and a method for producing the same. [Means for solving the problem]

[0006] One aspect of the present invention that solves the above problem is as follows. (1) A wholly aromatic ether ketone resin powder having a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter of 55°C or more.

[0007] (2) The wholly aromatic ether ketone resin powder according to (1) above, which has a melting point Tm1 measured by a differential scanning calorimeter of 345°C or higher and a peak width of the melting point Tm1 of 15°C or less.

[0008] (3) The wholly aromatic ether ketone resin powder according to (1) or (2) above, which is composed of one or more wholly aromatic ether ketone resins selected from the group consisting of polyether ketone, polyether ether ketone, and polyether ketone ether ketone ketone.

[0009] (4) A porous molded body obtained by molding the wholly aromatic ether ketone resin powder according to any one of (1) to (3) above, and having a porosity of 20 to 60%.

[0010] (5) A method for producing the wholly aromatic ether ketone resin powder according to (1) or (2), comprising the steps of: A method for producing wholly aromatic ether ketone resin powder, comprising the step of heat-treating a powder material containing fine particles of wholly aromatic ether ketone resin having a median diameter (D50) of 5 to 100 μm and a melting point Tm1 of 330 to 390°C as measured by a differential scanning calorimeter, at a temperature of (melting point Tm1 - 5°C) or higher (melting point Tm1 + 20°C) or lower for 6 to 48 hours.

[0011] (6) A method for producing the porous molded body according to (4), A method for producing a porous molded body, comprising the step of press-molding a material containing a wholly aromatic ether ketone resin powder having a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter of 55°C or more at a temperature of 350 to 390°C and a pressure of 0.1 to 30 MPa. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a wholly aromatic ether ketone resin powder capable of forming a porous molded body having high strength and a method for producing the same, as well as a porous molded body having high strength and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Fully aromatic ether ketone resin powder> The wholly aromatic ether ketone resin powder of this embodiment (hereinafter also simply referred to as "resin powder") is characterized in that it has a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured with a differential scanning calorimeter of 55°C or more.

[0014] The resin powder of this embodiment has a median diameter (D50) of 5 to 100 μm, and the difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter is 55° C. or more, so that a porous molded body having high strength can be molded by a predetermined heat treatment. Therefore, the resin powder of this embodiment is suitable for a porous molded body, i.e., as a material for obtaining a porous molded body. Here, the resin powder of this embodiment is composed of powder particles.

[0015] The median diameter (D50) of the resin powder of this embodiment is 5 to 100 μm. If the median diameter (D50) is less than 5 μm, the particle size is too small, making it difficult to form a spatially continuous phase, and the resin powder is therefore unsuitable as a porous body. If the median diameter (D50) is more than 100 μm, the particle size is too large and the resin powder will not become a porous body. The median diameter (D50) is preferably 10 to 95 μm, more preferably 15 to 90 μm, and even more preferably 20 to 85 μm. The median diameter (D50) refers to the particle size (D50) at 50% cumulative volume in the particle size distribution of the resin powder determined by laser diffraction scattering.

[0016] The resin powder of this embodiment has a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter of 55°C or more. If (Tm1-Tc) is less than 55°C, a porous molded body cannot be formed. The (Tm1-Tc) is preferably 55 to 110°C, more preferably 60 to 105°C, and even more preferably 65 to 100°C.

[0017] The resin powder of this embodiment preferably has a melting point Tm1 of 345°C or higher as measured by a differential scanning calorimeter. When the melting point Tm1 is 345°C or higher, a porous molded body can be favorably molded. The melting point Tm1 is preferably 345 to 405°C, more preferably 345 to 400°C, and even more preferably 345 to 390°C.

[0018] The resin powder of this embodiment preferably has a peak width of 15°C or less at the melting point Tm1 measured by a differential scanning calorimeter. When the peak width is 15°C or less, a porous molded body can be successfully molded. The peak width is preferably 5 to 15°C, more preferably 8 to 15°C, and even more preferably 10 to 15°C. The peak width of the melting point Tm1 is the difference between the start temperature (onset temperature) and end temperature (offset temperature) of the melting peak observed during the first run when heated from room temperature at a temperature increase rate of 10°C / min according to a method based on JIS K-7121 (1999). Here, the onset temperature is the intersection point between the baseline on the melting start side of the melting peak curve and the tangent at the inflection point of the curve. The offset temperature is the intersection point between the baseline on the melting end side of the melting peak curve and the tangent at the inflection point of the curve.

[0019] The wholly aromatic ether ketone resin constituting the resin powder of this embodiment may be one or more selected from the group consisting of polyether ketone (PEK), polyether ether ketone (PEEK), and polyether ketone ether ketone ketone (PEKEKK). Of these, polyether ether ketone resins are preferably polyether ether ketone (PEEK).

[0020] <Method for producing wholly aromatic ether ketone resin powder> The wholly aromatic ether ketone resin powder described above can be produced by the wholly aromatic ether ketone resin powder production method of this embodiment. That is, the wholly aromatic ether ketone resin powder production method of this embodiment is characterized by including a step of heat-treating a powder material containing fine particles of wholly aromatic ether ketone resin having a median diameter (D50) of 5 to 100 μm and a melting point Tm1 of 330 to 390°C as measured by a differential scanning calorimeter at a temperature of (melting point Tm1 - 5°C) or more and (melting point Tm1 + 20°C) or less for 6 to 48 hours.

[0021] In the method for producing resin powder of this embodiment, first, fine particles of a wholly aromatic ether ketone resin having a median diameter (D50) of 5 to 100 μm and a melting point Tm1 of 330 to 390° C. measured by a differential scanning calorimeter are prepared.

[0022] (Fine particles of fully aromatic ether ketone resin) The fine particles of wholly aromatic ether ketone resin used in the production method of this embodiment are, in other words, the raw material for the resin powder of this embodiment. The fine particles of wholly aromatic ether ketone resin have a median diameter (D50) of 5 to 100 μm and a melting point Tm1 of 330 to 390°C as measured by a differential scanning calorimeter. In this specification, the term "fine particles" refers to particles having a median diameter (D50) of about 0.1 to 1000 μm. The "median diameter (D50)" is as defined above.

[0023] In this embodiment, the median diameter (D50) of the fine particles of the wholly aromatic ether ketone resin is 5 to 100 μm. If the median diameter (D50) is less than 5 μm or exceeds 100 μm, it becomes difficult to produce the resin powder described above. The median diameter (D50) is preferably 10 to 95 μm, more preferably 15 to 90 μm, and even more preferably 20 to 85 μm.

[0024] In this embodiment, the melting point Tm1 of the wholly aromatic ether ketone resin fine particles measured with a differential scanning calorimeter is 330 to 390°C. If the melting point Tm1 is less than 330°C, the particles will undergo plastic deformation during molding, preventing the formation of a porous body, while if it exceeds 390°C, the particles will not bond together, preventing the formation of a porous body. The melting point Tm1 is preferably 330 to 385°C, more preferably 330 to 380°C, and even more preferably 330 to 375°C. The melting point Tm1 is as described above.

[0025] As the fine particles of the wholly aromatic ether ketone resin, the above-mentioned commercially available wholly aromatic ether ketone resin can be used as it is, or the wholly aromatic ether ketone resin can be formed into pellets, fibers, films, etc. and then pulverized by dry pulverization, wet pulverization, or freeze pulverization using a jet mill, bead mill, hammer mill, ball mill, cutter mill, stone mill, or the like. Alternatively, a wholly aromatic ether ketone resin can be used, which is obtained by a method of dissolving a wholly aromatic ether ketone resin in a solvent and then spray-drying it, a poor solvent precipitation method in which an emulsion is formed in a solvent and then brought into contact with a poor solvent, a submerged drying method in which an emulsion is formed in a solvent and then the organic solvent is dried and removed, etc. A method can also be used in which a wholly aromatic ether ketone resin and a thermoplastic resin are mixed, and then the thermoplastic resin is dissolved and removed with a solvent to obtain fine particles of the wholly aromatic ether ketone resin having the above median diameter (D50).

[0026] The preferred range of the median diameter (D50) of the wholly aromatic ether ketone resin fine particles is the same as the median diameter (D50) of the wholly aromatic ether ketone resin powder described above, because the median diameter (D50) does not change when the wholly aromatic ether ketone resin fine particles are subjected to a heat treatment as described below.

[0027] (powder material) In the manufacturing method of this embodiment, various fibrous, granular, and plate-like inorganic and organic fillers are added to the fine particles of the wholly aromatic ether ketone resin as required to obtain a powder material.

[0028] Examples of fibrous fillers include inorganic fibrous materials such as glass fiber, milled glass fiber, carbon fiber, asbestos fiber, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, silicate fibers such as wollastonite, magnesium sulfate fiber, aluminum borate fiber, and metal fibers such as stainless steel, aluminum, titanium, copper, and brass. A particularly representative fibrous filler is glass fiber. High-melting-point organic fibrous materials such as polyamide, fluororesin, polyester resin, and acrylic resin can also be used. Examples of powdery and granular fillers include carbon black, graphite, silica, quartz powder, glass beads, glass balloons, glass powder, silicates such as calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, and wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, as well as ferrite, silicon carbide, silicon nitride, boron nitride, and various metal powders. Examples of the plate-like filler include mica, glass flakes, talc, and various metal foils. These inorganic and organic fillers can be used alone or in combination of two or more.

[0029] The content of the filler can be 5 to 200 parts by mass relative to 100 parts by mass of the wholly aromatic ether ketone resin. The wholly aromatic ether ketone resin may further contain additives such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, pigments, and crystal nucleating agents.

[0030] In the manufacturing method of this embodiment, the powder material containing the above-mentioned fine particles of wholly aromatic ether ketone resin is heat-treated at a temperature of (melting point Tm1-5°C) or more (melting point Tm1+20°C) or less for 6 to 48 hours.

[0031] In this embodiment, the powder material is heat-treated at a temperature between (melting point Tm1 - 5°C) and (melting point Tm1 + 20°C). If the temperature is below (melting point Tm1 - 5°C), the surface modification of the particles will proceed too slowly to form a porous body, and if the temperature exceeds (melting point Tm1 + 20°C), the particles will fuse together at the time of surface treatment. The heat treatment temperature is preferably between (melting point Tm1 - 5°C) and (melting point Tm1 + 20°C), and more preferably between (melting point Tm1 - 0°C) and (melting point Tm1 + 15°C). The heat treatment time is 6 to 48 hours, but if the time is less than 6 hours, the surface treatment will be insufficient, causing plastic deformation and failing to form a porous body, while if the time exceeds 48 hours, the surface treatment will be excessive, preventing bonding between particles and failing to form a porous body. The heat treatment time is preferably 10 to 36 hours, more preferably 12 to 24 hours.

[0032] <Porous molded body> The porous molded body of this embodiment is formed by molding the wholly aromatic ether ketone resin powder of this embodiment described above, and is characterized by having a porosity of 20 to 60%.

[0033] The porous molded body of this embodiment is obtained by molding the wholly aromatic ether ketone resin powder of this embodiment described above, and therefore has good moldability and high strength.

[0034] The porous molded body of this embodiment has a porosity of 20 to 60%, preferably 25 to 55%. Since the porosity is 20 to 60%, high strength can be maintained. Specifically, the body is excellent in bending strength, bending modulus, and bending strain. The porosity can be adjusted by setting the temperature and pressure in the press molding process within predetermined ranges.

[0035] The porosity can be calculated, for example, from the amount of various fluids such as water and mercury filled under pressure. Alternatively, it can be calculated more simply from the relationship between the apparent specific gravity and the true specific gravity measured using a hydrometer, using the following formula (I): Porosity (%) = (1 - (apparent specific gravity) / (true specific gravity)) × 100 (I)

[0036] The porous molded body of this embodiment is a heat-resistant porous molded body having high strength, and therefore can be preferably used in various applications such as filters, sound-absorbing materials, impregnation materials, coating materials, medical-related parts, information-related parts, and electronics parts.

[0037] The strength of the porous molded body obtained by molding the resin powder of this embodiment is preferably such that no breakage is observed when a load of 80 N is applied using a Barcol hardness tester with a glass plate 40 mm in diameter and 3 mm thick placed on the porous molded body.

[0038] <Method of manufacturing porous molded body> The method for producing a porous molded body of this embodiment includes a step of press-molding a material containing a wholly aromatic ether ketone resin powder having a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter of 55° C. or more at a temperature of 350 to 390° C. and a pressure of 0.1 to 30 MPa. In other words, the production method of this embodiment involves press-molding a material containing the resin powder of this embodiment at a predetermined temperature and a predetermined pressure to obtain a porous molded body.

[0039] In the method for producing a porous molded body of this embodiment, a wholly aromatic ether ketone resin powder is mixed with a filler and other additives as necessary to obtain a material containing the wholly aromatic ether ketone resin powder to be subjected to press molding.

[0040] (press molding) Press molding involves press-molding a material containing wholly aromatic ether ketone resin powder at a temperature of 350 to 390°C, preferably 350 to 370°C, more preferably 350 to 360°C, and at a pressure of 0.1 to 30 MPa, preferably 0.1 to 20 MPa. By press molding, the wholly aromatic ether ketone resin powder is partially fused while maintaining voids at the interfaces where the powder particles overlap, forming a porous molded body. If the temperature and pressure are outside the above ranges, the adhesion between the powder particles in the wholly aromatic ether ketone resin powder is poor, and the porous molded body is prone to breakage.

[0041] The wholly aromatic ether ketone resin powder may be used alone or in a mixture of two or more types. It is preferable to use a blend of two or more wholly aromatic ether ketone resin powders, as this facilitates control of the semi-molten state described below and improves the strength of the porous molded body. To produce the porous molded body, a material consisting solely of the wholly aromatic ether ketone resin powder may be used, or a mixed material in which the wholly aromatic ether ketone resin powder is mixed with a filler or other additives may be used. The fillers and additives that can be blended with the wholly aromatic ether ketone resin powder may be the same as those that can be blended with the wholly aromatic ether ketone resin powder. When used as a mixed material, the amount of the wholly aromatic ether ketone resin powder used is preferably 10% by mass or more, more preferably 20% by mass or more, of the total material. The amount of the filler and additives used may be 90% by mass or less, or even 80% by mass or less, of the total material. Conventional mixing methods can be used, such as a shaking mixing method, a mixing method involving pulverization using a ball mill or the like, or a mixing method using a stirring blade such as a Henschel mixer.

[0042] In this embodiment, a material containing a predetermined wholly aromatic ether ketone resin powder is used as described above. By performing press molding within the above temperature and pressure ranges, the wholly aromatic ether ketone resin can be press molded in a semi-molten state. Press molding in a semi-molten state can increase the strength of the porous molded body. Furthermore, when press molding in a semi-molten state, the porosity and strength of the porous molded body can be adjusted by adjusting the press pressure. As a result, it is possible to control the properties of the porous molded body, such as its strength, dielectric properties, air permeability, and permeability. For example, a porous molded body press molded in a semi-molten state can have a porosity of 40% to 55% and a relative dielectric constant of less than 2. In contrast, when press molding in an unmolten state using only press pressure, a high press pressure is required to obtain a porous molded body with the desired strength. In this case, the porosity is excessively reduced, resulting in deterioration of the properties.

[0043] The press molding method is not particularly limited, and conventionally known methods can be used. Examples of press molding methods include filling a jig with a material and pressure molding it at a temperature of 350 to 390°C, preferably 350 to 370°C or less, more preferably 350 to 360°C, and at a pressure of 0.1 to 30 MPa, preferably 0.1 to 20 MPa. The melting point Tm1 is the melting point Tm1 of the wholly aromatic ether ketone resin powder. A porous molded body can then be obtained by allowing it to cool. The porous molded body thus obtained has high strength because it is formed using a powder material containing the wholly aromatic ether ketone resin powder.

[0044] (Other processes) As a further separate step, a sintering step may be included in which the porous molded body obtained in the press molding step is further heated and sintered in an oven, etc., in order to further increase the adhesion between the wholly aromatic ether ketone resin fine particles. The sintering step can be a step in which the porous molded body obtained in the press molding step is heated and sintered at a temperature of, for example, 270°C to 305°C, preferably 275°C to 300°C, for 1 hour to 20 hours, preferably 1 hour to 20 hours. [Example]

[0045] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to the following examples.

[0046] [Fully aromatic ether ketone resin] The fine particles of wholly aromatic ether ketone resin (PAEK) used in the examples and comparative examples are as follows. PEEK1: Polyetheretherketone (Polypla-Evonik Co., Ltd., VESTAKEEP (registered trademark), 2000FP) PEEK2: Polyetheretherketone (Polypla-Evonik Co., Ltd., VESTAKEEP (registered trademark), 4000FP)

[0047] [Examples 1 to 12 and Comparative Examples 1 to 14] In each Example and Comparative Example, the melting point Tm1, melt volume rate, and median diameter (D50) of the wholly aromatic ether ketone resin fine particles (PEEK1 or PEEK2) shown in Tables 1 and 2 were measured by the methods described below. The measurement results are shown in Tables 1 and 2. Fine particles of wholly aromatic ether ketone resin were heat-treated using a heat treatment device (Super Temp Oven, STPH-102, high-temperature incubator, manufactured by Espec Corporation) under the heat treatment conditions (temperature and time) shown in Tables 1 and 2 to obtain wholly aromatic ether ketone resin powder. In Examples 5, 6, 11, and 12, the heat treatment was carried out in two stages to shorten the treatment time. That is, the melting point of the wholly aromatic ether ketone resin was increased by the heat treatment in the first stage, and the total heat treatment time could be shortened by performing the heat treatment at a higher temperature in the second stage. The peak width of the melting point Tm1 of the heat-treated wholly aromatic ether ketone resin powder was measured by the method described below. The results are shown in Tables 1 and 2.

[0048] 2.4 g of the obtained wholly aromatic ether ketone resin powder was filled into a mold for a bending test piece of 80 × 10 × 4 mm, and a porous molded body was produced using a hot press molding machine ("Mini Test Press-10" manufactured by Toyo Seiki Seisakusho, Ltd.) under the temperature and pressure conditions shown in Tables 1 and 2. After hot pressing, the porous molded body was allowed to cool at room temperature for 12 hours. The porosity and strength of this porous molded body were evaluated by the methods described below. The results are shown in Tables 1 and 2.

[0049] [measurement] (Melting point Tm1 and crystallization temperature Tc) According to a method based on JIS K-7121 (1999), a differential scanning calorimeter (Hitachi High-Tech Science, DSC7000X) was used to measure the melting point Tm1, the peak top temperature of the melting peak observed when heated from room temperature at a heating rate of 20 ° C. / min (1st RUN), and then the sample was held at a temperature of (melting point Tm1 + 40) ° C. for 2 minutes, and then cooled to room temperature at a heating rate of 20 ° C. / min. The onset temperature of the exothermic peak observed when the sample was cooled was measured as the crystallization temperature Tc. The onset temperature is the intersection of the baseline on the solidification start side of the exothermic peak curve and the tangent at the inflection point of the curve.

[0050] (Melt Volume Rate (MVR)) The melt volume rate (MVR) was measured using a melt indexer (manufactured by Toyo Seiki Seisakusho, Ltd.) at a cylinder temperature of 380°C in accordance with Method B of JIS K7210-1:2014 (ISO 1133-1:2011).

[0051] (Median diameter (D50)) The median diameter (D50) was measured using a laser diffraction / scattering particle size distribution analyzer (LA-960, manufactured by Horiba, Ltd.) The median diameter (D50) is the particle size (D50) at a volume cumulative of 50%.

[0052] (Peak width of melting point Tm1) According to a method based on JIS K-7121 (1999), a differential scanning calorimeter (Hitachi High-Tech Science Corporation, DSC7000X) was used to measure the melting peak width of the melting point Tm1, which was measured by heating from room temperature at a temperature increase rate of 20°C / min (1st RUN). The difference between the start temperature (onset temperature) and end temperature (offset temperature) of the melting peak was measured. The onset temperature was the intersection of the baseline on the melting start side of the melting peak curve with the tangent at the inflection point of the curve. The offset temperature was the intersection of the baseline on the melting end side of the melting peak curve with the tangent at the inflection point of the curve.

[0053] [evaluation] The porosity and strength of the porous molded bodies obtained in Examples 1 to 12 were evaluated by the following methods. The results are shown in Table 1. Note that for all of Comparative Examples 1 to 14, porous molded bodies with good moldability were not obtained, and therefore the following evaluations could not be performed. Therefore, in Table 2, they are marked as "evaluation not possible."

[0054] (porosity) The porosity was calculated from the apparent specific gravity and true specific gravity using the following formula (I). The apparent specific gravity was measured using a hydrometer (Mirage Electronic Hydrometer SD-120L). The true specific gravity was measured using the same hydrometer on a non-porous molded body produced by injection molding. Porosity = (1 - (apparent specific gravity) / (true specific gravity)) x 100 (I)

[0055] (strength) The resulting porous molded body was used to measure the bending strength, bending modulus, and bending strain in accordance with ISO 178 (JIS K7171) under the following test conditions. [Test conditions] Testing machine: Shimadzu Corporation, Autograph AGS-X 5kN Indenter radius: 5mm Fulcrum radius: 5mm Distance between fulcrums: 64mmm Test speed: 2mm / min Temperature: 23℃

[0056] (Moldability) The appearance of the resulting porous molded body was visually observed and evaluated according to the following evaluation criteria. Rating 1: After molding, the shape is not formed before demolding. Rating 2: After molding, the molded product cracks when released from the mold. Evaluation 3: After molding, the molded product retains its shape when released from the mold, but is easily broken by hand. Evaluation 4: After molding, the molded product retains its shape when released from the mold. Of these, only evaluation 4, which means that it can be used as a molded product, was judged to have good moldability.

[0057] [Table 1]

[0058] [Table 2]

[0059] From Tables 1 and 2, it can be seen that porous molded bodies having high strength could be produced from all of the wholly aromatic ether ketone resin powders of Examples 1 to 12. In particular, when (Tm1 - Tc) was 65°C or higher, the flexural modulus was excellent. In contrast, in Comparative Examples 1 to 14, the moldability was poor and even sufficient molding was not possible, so evaluation was not possible.

Claims

1. A wholly aromatic ether ketone resin powder having a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between a melting point Tm1 and a crystallization temperature Tc measured by a differential scanning calorimeter of 55° C. or more.

2. 2. The wholly aromatic ether ketone resin powder according to claim 1, which has a melting point Tm1 measured by a differential scanning calorimeter of 345°C or higher and a peak width of the melting point Tm1 of 15°C or lower.

3. 3. The wholly aromatic ether ketone resin powder according to claim 1, which is composed of one or more wholly aromatic ether ketone resins selected from the group consisting of polyether ketone, polyether ether ketone, and polyether ketone ether ketone ketone.

4. A porous molded body obtained by molding the wholly aromatic ether ketone resin powder according to claim 1 or 2, having a porosity of 20 to 60%.

5. A method for producing the wholly aromatic ether ketone resin powder according to claim 1 or 2, comprising: A method for producing a wholly aromatic ether ketone resin powder, comprising the step of heat-treating a powder material containing fine particles of a wholly aromatic ether ketone resin having a median diameter (D50) of 5 to 100 μm and a melting point (Tm1) of 330 to 390°C as measured by a differential scanning calorimeter, at a temperature of (melting point (Tm1) - 5°C) or more and (melting point (Tm1) + 20°C) or less for 6 to 48 hours.

6. A method for producing the porous molded body according to claim 4, A method for producing a porous molded body includes a step of press-molding a material containing a wholly aromatic ether ketone resin powder having a median diameter (D50) of 5 to 100 μm and a difference (Tm1-Tc) between the melting point Tm1 and the crystallization temperature Tc measured by a differential scanning calorimeter of 55°C or more at a temperature of 350 to 390°C and a pressure of 0.1 to 30 MPa.

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