Reinforced PAEK composition containing recycled carbon fiber

Abstract

A method for recycling PEKK-based carbon fiber reinforced polymer composites is provided. Chips obtained by grinding the carbon fiber reinforced PEKK composite are melt-mixed with virgin poly(aryl ether ketone) polymer to provide a carbon fiber reinforced poly(aryl ether ketone) composition. Molded articles having good mechanical properties can be manufactured from the carbon fiber reinforced poly(aryl ether ketone) composition.

Description

[Technical Field]

[0001] This application claims priority under U.S. Provisional Patent Application No. 63 / 042035, filed on 22 June 2020, and European Patent Application Publication No. 20186867.6, filed on 21 July 2020, the entire contents of each of these applications being incorporated herein by reference for all purposes.

[0002] The present invention relates to a method for producing a composition containing carbon fibers and a polyaryl ether ketone polymer. [Background technology]

[0003] Carbon fiber reinforced polymer (CFRP), or fiber-reinforced composite materials, which use carbon fibers as the primary structural component and thermosetting or thermoplastic polymers as the matrix component, are lightweight and strong materials used in the manufacture of a wide range of products. Their demand has been steadily increasing in recent years, for example, to replace many metal parts in aircraft to reduce weight while maintaining high performance. This has resulted in a large amount of manufacturing residue and used products. Unlike metals, the waste generated during the manufacture of carbon fiber composites, along with used products, has limited reuse options. Scrap generated during the manufacture of conventional metal parts is easily recycled, minimizing waste. With carbon fiber composites, reuse options for scraps and trim waste are currently limited, and they are primarily disposed of by landfill or incineration.

[0004] These methods not only provide solutions for identifying sustainable disposal methods and preventing waste accumulation, but also have led to increased environmental awareness to address the continuing rise in demand for virgin carbon fiber.

[0005] Therefore, it is necessary to identify useful methods for recycling and reusing waste carbon fiber composite materials, thereby avoiding the waste disposal problems that may arise if they are not recycled.

[0006] An increasing number of users are beginning to recognize the potential of carbon fiber composite materials whose polymer matrix consists of engineered thermoplastic polymers such as poly(aryl ether ketone) (PAEK) and polyphenylene sulfide (PPS). Thermoplastic polymers offer manufacturers faster processing times, increased toughness, and a near-infinite shelf life.

[0007] In particular, the inventors investigated the possibility of reusing carbon fiber reinforced composite materials containing thermoplastic matrices, especially matrices containing poly(aryl ether ketone) polymers.

[0008] Mechanical recycling is one of the available recycling methods for fiber-reinforced composite materials. Generally, mechanical recycling is a technique used to reduce the size of scrap composite materials for reuse.

[0009] Mechanical recycling of poly(etheretherketone)-based carbon fiber composite materials (hereinafter referred to as CF / PEEK) has been disclosed previously.

[0010] Li H., Englund K.; “Recycling of carbon fiber-reinforced thermoplastic composite wastes from the aerospace industry”; J. Compos. Mater., 51, 1265-1273 (2017) and Ramakrishna S., Tan WK, Teoh SH, et al.; “Recycling of carbon fiber / PEEK composites”; Key. Eng. Mater., 137, 1-8 (1997) both disclose a method for reducing the size of CF / PEEK composite parts using mechanical means (hammer mill and / or shredder and rotary blade granulator), then compressing and molding them into test specimens for mechanical testing. Both studies showed that the mechanical properties of parts obtained using recycled CF / PEEK composites were reduced compared to the original composite material.

[0011] Schinner G, Brandt J, and Richter H.; “Recycling carbonfiber-reinforced thermoplastic composites”, J.Thermoplast.Compos.Mater.;9,239-245(1996) discloses a method for recycling CF / PEEK composites in which crushed CF / PEEK composite material is used to reinforce virgin PEEK injection molded material. According to this paper, injection molded pieces obtained using recycled CF / PEEK material had properties comparable to those of equivalent virgin injection molded carbon fiber-reinforced PEEK material.

[0012] This study found that recycling poly(etherketone)-based carbon fiber composite materials (hereinafter referred to as "CF / PEKK") yields a poly(aryletherketone) composition containing recycled composite materials with excellent mechanical properties. Remarkably, it was discovered that using recycled CF / PEKK composite materials yields a carbon fiber-reinforced poly(aryletherketone) composition with superior mechanical properties compared to conventional poly(aryletherketone) compositions containing recycled CF / PEEK composite materials. [Modes for carrying out the invention]

[0013] Therefore, the first object of the present invention is a method for producing a carbon fiber-reinforced poly(aryl ether ketone) composition by using chips obtained from a CF / PEKK composite material as a carbon fiber source.

[0014] In this specification, the term CF / PEKK composite material is used to refer to carbon fiber composite materials based on poly(etherketoneketone), PEKK.

[0015] Therefore, the object of the present invention is a method for producing a carbon fiber-reinforced poly(aryl ether ketone) composition, and the method is - To prepare chips made of CF / PEKK composite material, and - Melt-mix the chip with at least one poly(aryl ether ketone) polymer (hereinafter referred to as "PAEK polymer") which is different from the PEKK polymer in the CF / PEKK composite material, and at least one optional polymer (hereinafter referred to as "polymer (OP)") which is different from both the PAEK polymer and the PEKK polymer in the CF / PEKK composite material. Includes.

[0016] The expression "carbon fiber reinforced poly(aryl ether ketone) composition" (hereinafter "reinforced PAEK composition") is used to refer to a composition containing one or more polymers selected from the group of poly(aryl ether ketone) polymers and carbon fibers. The carbon fibers in the poly(aryl ether ketone) composition are discontinuous chopped carbon fibers.

[0017] For the purposes of the present invention, the term "poly(aryl ether ketone)" is used interchangeably with the term "PAEK" and is intended to refer to any polymer having repeating units in which more than 50 mol% of the repeating units contain Ar-C(=O)-Ar' groups (where Ar and Ar' are the same as or different from each other and are aromatic groups), and the mol% is based on the total number of moles of repeating units in the polymer. The repeating units are usually selected from the group consisting of the following formulas (J-A) to (J-O):

Chemical formula

Chemical formula

Chemical formula

[0018] In the repeating units (J-A) to (J-O), each phenylene moiety can independently have a 1,2-, 1,4-, or 1,3-bond to other moieties different from R' in the repeating unit. Preferably, the phenylene moiety has a 1,3- or 1,4-bond.

[0019] Preferably, the phenylene moiety has no substituents other than those that allow bonding in the polymer backbone. That is, j’ is preferably zero in each instance.

[0020] The poly(aryl ether ketone) suitable for the method of the present invention preferably has an intrinsic viscosity (IV) in the range of about 0.5 to about 1.8 dL / g when measured in concentrated sulfuric acid (minimum 96%) at a concentration of 0.1% at 25 °C according to ASTM D2857-95. The poly(aryl ether ketone) preferably has a melt viscosity of about 0.05 to 0.65 kPa·s (measured at a shear rate of 1000 s -1 at 400 °C).

[0021] Any poly(aryl ether ketone) polymer different from the PEKK polymer in the CF / PEKK composite material can be used in the method.

[0022] Notable examples of suitable poly(aryl ether ketones) are, for example, poly(ether ketone) (PEK), poly(ether ether ketone) (PEEK), poly(ether ether ketone ketone) (PEEKK), and poly(ether ketone ether ketone ketone) (PEKEKK) polymers.

[0023] In an advantageous embodiment, the poly(aryl ether ketone) polymer is a homopolymer of poly(ether ether ketone), PEEK, i.e., j’ = 0 and all phenylene moieties have 1,4-linkages in the repeating unit (J-A).

[0024] Any PEEK polymer suitable for the production of the carbon fiber filler molding composition can be used. The PEEK polymer preferably has a melt viscosity of about 0.05 to 0.50 kPa·s (measured at 400 °C, 1000 s -1 ).

[0025] Alternatively, poly(aryl ether ketone) polymers can be selected from PEEK-PEoEK copolymers, i.e., polymers of repeating units (JA) where j'=0 and the phenylene moiety independently has 1,2- and 1,4-bonds. PEoEK polymers typically contain repeating units of the following formulas (A') and (B'): [ka]

[0026] Typically, the PEoEK polymer is selected from the polymers defined above, where the ratio of the total number of moles of repeating units (A') to the total number of moles of repeating units (B') is in the range of 95 / 5 to 70 / 30, preferably 90 / 10 to 72 / 28, more preferably 85 / 15 to 74 / 26, for example, molar ratios of about 95 / 5, about 90 / 10, about 85 / 15, about 80 / 20, about 75 / 25, or about 70 / 30.

[0027] Poly(aryl ether ketone) polymers can also be selected from PEEK-PEDEK copolymers, which are polymers containing repeating units (JA) and (JD) (where j'=0 and all phenylene moieties have 1,4-bonds). PEEK-PEDEK copolymers typically contain repeating units of the following formulas (A') and (C'): [ka]

[0028] The repeating units (C') and (A') are present in the PEDEK-PEEK copolymer in a (C') / (A') molar ratio in the range of 55 / 45 to 80 / 20, preferably 60 / 40 to 80 / 20, and more preferably 60 / 40 to 75 / 25.

[0029] In one embodiment of the present invention, a CF / PEKK composite material chip is melt-mixed with one or more PAEK polymers.

[0030] In another embodiment of the present invention, the CF / PEKK composite material chip is melt-mixed with one or more PAEK polymers and one or more other polymers OP.

[0031] Typically, one or more PAEK polymers are present in greater quantities than one or more other polymer OPs. The total weight of PAEK polymers is usually at least 50% by weight of the total weight of PAEK polymers and polymer OPs.

[0032] Polymer OP can be selected from any polymer suitable for melt mixing with poly(aryl ether ketone) polymers.

[0033] In one embodiment of the above, polymer OP is selected from the group of poly(aryl ether sulfone) polymers and is hereafter referred to as "PAES polymer". For the purposes of this disclosure, the terms "poly(aryl ether sulfone)" or "PAES polymer" mean that at least 50 mol% of the repeating units are the repeating units (R) of formula (K). PAES This refers to any polymer that is ), and mol% is based on the total number of moles of repeating units in the polymer: [ka] (In the formula, R is independently selected at each position from the group consisting of halogens, alkyls, alkenyls, alkynyls, aryls, ethers, thioethers, carboxylic acids, esters, amides, imides, alkali or alkaline earth metal sulfonates, alkyl sulfonates, alkali or alkaline earth metal phosphonates, alkyl phosphonates, amines, and quaternary ammonium compounds. For each R, h is independently zero or an integer in the range of 1 to 4. T is a bond, a sulfone group [-S(=O)] 2- ], and base-C(R j )(R k )-(Here, R j and R kis selected from the group consisting of (which are equal to or different from each other and are selected from hydrogen, halogen, alkyl, alkenyl, alkynyl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium).

[0034] T is preferably a bond, a sulfone group or the group -C(R j )(R k )-(wherein R j and R k are preferably methyl groups).

[0035] Notable examples of suitable poly(aryl ether sulfone) are, for example, polysulfone (PSU), polyphenyl sulfone (PPSU), or polyether sulfone (PES) polymers.

[0036] The term polysulfone (PSU) means any polymer containing at least 50 mol% of the repeating unit of formula (L), and mol% is based on the total number of moles in the polymer:

Chemical formula

[0037] The term polyphenyl sulfone (PPSU) means any polymer containing at least 50 mol% of the repeating unit of formula (M), and mol% is based on the total number of moles of the repeating units in the polymer:

Chemical formula

[0038] The term polyether sulfone (PES) means any polymer containing at least 50 mol% of the repeating unit of formula (O), and mol% is based on the total number of moles of the repeating units in the polymer:

Chemical formula

[0039] In one aspect of the present invention, a chip of CF / PEKK composite material is melt-mixed with a composition comprising one or more PAEK polymers, polyphenylsulfone (PPSU), and polyethersulfone (PES).

[0040] The composition preferably comprises PEEK, polyphenylsulfone (PPSU), and polyethersulfone (PES). The composition may contain 50-60% by weight of PEEK, 30-40% by weight of polyethersulfone (PES), and 5-10% by weight of polyphenylsulfone (PPSU), where the weight percentages are based on the total weight of the composition.

[0041] To avoid any ambiguity, the terms "poly(etherketoneketone)" or "PEKK" are intended to represent any polymer containing at least 50 mol% repeating units (JB), where j'=0, and where each phenylene moiety may independently have 1,2-, 1,4-, or 1,3-bonds, preferably the phenylene moiety having 1,3- or 1,4-bonds.

[0042] PEKK polymers can be characterized by the ratio of 1,3-phenylene bonds to 1,4-phenylene bonds in the polymer. In particular, the ratio of repeating units of the following equations (M') and (P') can differ: [ka]

[0043] Typically, the PEKK polymer in the CF / PEKK composite material is selected from the PEKK polymers defined above, and the ratio of the total number of moles of repeating units (P') to the total number of moles of repeating units (M') ("(P') / (M') ratio" or "T / I ratio") is in the range of 55 / 45 to 75 / 25, preferably 60 / 40 to 80 / 20, and more preferably 62 / 38 to 75 / 25.

[0044] When poly(aryl ether ketone) is a PEKK polymer, it is typically characterized by a different T / I ratio relative to the PEKK polymer in the CF / PEKK composite material.

[0045] In the first step of the method, a chip made of CF / PEKK composite material is prepared.

[0046] CF / PEKK composite chips are typically obtained by grinding articles made of CF / PEKK composite material.

[0047] Therefore, the method of the present invention includes the following steps: - The process of preparing articles made of CF / PEKK composite material; - A step of crushing the aforementioned article to obtain chips of CF / PEKK composite material; and - A step of melt-mixing the chip with at least one poly(aryl ether ketone) polymer different from PEKK in the CF / PEKK composite material.

[0048] Articles made from CF / PEKK composite materials may, to name a few, be waste from the composite material manufacturing process, or prepreg unitap manufacturing residues such as scraps or trim waste, or products that do not meet the thickness specifications, or used products.

[0049] In one embodiment of the method of the present invention, the article consists of edge trim or scrap waste generated during the manufacture of CF / PEKK composite material.

[0050] In one preferred embodiment of the above-described model, the CF / PEKK composite material comprises a unidirectional continuous fiber-reinforced tape produced by a melt-impregnation process. The melt-impregnation process typically involves drawing a plurality of continuous filaments through a molten precursor composition containing a polymer. The precursor composition may additionally contain certain components such as plasticizers and processing aids that facilitate impregnation. Melt-impregnation processes include direct melt and aromatic polymer composite ("APC") processes, as described in European Patent No. 102158.

[0051] Advantageously, the CF / PEKK composite material is obtained by melt impregnation in the presence of diphenyl sulfone as a plasticizer. The residual amount of diphenyl sulfone in the CF / PEKK composite material is 0.01% to 1.00% by weight relative to the total weight of the CF / PEKK composite material. The amount of diphenyl sulfone may be 0.03% to 0.90% by weight, more preferably 0.04 to 0.85% by weight, and more preferably 0.04 to 0.80% by weight.

[0052] While not bound by theory, the presence of diphenyl sulfone in the CF / PEKK chip is thought to improve the bonding of carbon fibers with the poly(aryl ether ketone) polymer in the composition.

[0053] In another embodiment, the composite material includes a unidirectional continuous fiber-reinforced tape manufactured by a slurry process. An exemplary slurry process can be found, for example, in U.S. Patent No. 4,792,481.

[0054] CF / PEKK composite materials typically contain 20–80% by weight of carbon fibers, more typically 40–80% by weight. CF / PEKK composite materials typically contain 80–20% by weight of PEKK polymer, more typically 60–20% by weight of the composite material.

[0055] The process of crushing a CF / PEKK composite article into chips, i.e., shredding or cutting, is typically carried out using mechanical means. Any mechanical means known in the art can be used, such as blades, e.g., die-cutting blades or roller blades, die-cutting grids, shredders, or any other suitable means. A laser may be used to crush the CF / PEKK article into chips.

[0056] The length of the chips into which the CF / PEKK composite material articles are cut is preferably in the range of 3 to 50 mm, and more particularly in the range of 5 to 20 mm. The length of the chips should also be selected to match the feeding capacity of the machine used to mix the CF / PEKK composite material chips with at least one poly(aryletherketone) polymer.

[0057] When chips of CF / PEKK composite material are melt-mixed with at least one poly(aryl ether ketone) polymer, the individual chips disintegrate into individual fibers, which are then mixed into the polymer molten material. The properties of the reinforced PAEK composition thus obtained correspond to the properties of the chopped strand reinforced polymer.

[0058] Any known melt-mixing process suitable for preparing thermoplastic molded compositions can be used in the production of reinforced PAEK compositions. Such processes are typically carried out by heating a thermoplastic polymer above its melting temperature, thereby forming a molten thermoplastic polymer.

[0059] The preparation process for the reinforced PAEK composition can be carried out in a melt mixing apparatus. Any melt mixing apparatus known to those skilled in the art for preparing polymer compositions by melt mixing can be used. Suitable melt mixing apparatuses include, for example, kneaders, Banbury mixers, single-screw extruders, twin-screw extruders, and injection molding machines.

[0060] By adding the chips to the polymer molten material, the molten material and the chips are mixed more uniformly, resulting in a more uniform distribution of individual fibers within the polymer molten material.

[0061] When melt mixing is performed using an extruder, a multi-screw extruder, such as a twin-screw extruder, can be used. Twin-screw extruders offer particularly superior mixing efficiency compared to single-screw extruders, and therefore, using a twin-screw extruder can be advantageous in some cases.

[0062] The proportion of chips in the CF / PEKK composite material, melt-mixed with at least one poly(aryl ether ketone) and at least one other optionally selected polymer OP, is such that the amount of carbon fiber in the final reinforced PAEK composition is 5 to 60% by weight of the total weight of the composition. Typically, the proportion of chips is such that the amount of carbon fiber in the reinforced PAEK composition is 5 to 60% by weight, more preferably 5 to 50%, more preferably 10 to 50%, and more preferably 10 to 45% by weight of the total weight of the composition.

[0063] The reinforced PAEK composition obtained by the method of the present invention is preferably in the form of a pellet material. However, in addition to the pellet material, the reinforced PAEK composition may also be in the form of a sheet or an extruded product. When the reinforced PAEK composition is in the form of pellets, these pellets are produced by a conventional method of cutting a polymer molten material into pellets by a pelletizing knife through a pelletizing die.

[0064] One possible way to do this is to first produce a polymer extrusion, cool it, and then cut it into pellets. Alternatively, and conventionally, the polymer passed through a pelletizing die is directly cut. This cutting can be done in air, in which case the cut pellets preferably fall into a coolant and solidify. Water is an example of a suitable coolant. Alternatively, underwater pelletizing is also possible. In this case, the polymer molten material is extruded through a pelletizing die into a coolant and directly cut into pellets. In either case, the pellets are transported with the coolant, and then the coolant is removed and they are dried.

[0065] The length of carbon fibers in a reinforced PAEK composition depends, firstly, on the shearing of the fibers in the melt mixer, and secondly, on the dimensions of the pellet material cut from the polymer molten mass. The maximum fiber length corresponds to the maximum longitudinal spread of the individual pellet. If longer fibers are desired, it is necessary to produce larger pellets, in addition to cutting them into tips with longer edge lengths. The pellets are preferably cylindrical, and their maximum spread is typically the height of the cylinder. However, it is also possible to choose a larger diameter and a lower height instead. However, since the fibers are aligned by the feeding of the polymer molten mass in a configuration substantially parallel to the axial direction with respect to the axis of the hole in the pelletizing die, it is typically the axial spread of the pellet that determines the maximum achievable fiber length.

[0066] Typically, the carbon fibers in the reinforced PAEK composition have an average length ranging from 0.05 to 10 mm, 0.05 to 6 mm, and even 0.1 to 5 mm, more typically 0.1 to 3 mm.

[0067] Reinforced PAEK compositions can be further processed into articles using any suitable melting process technique, including but not limited to extrusion, injection molding, and compression molding.

[0068] According to exemplary embodiments, a reinforced PAEK composition obtained by the method of the present invention, in which chips of CF / PEKK composite material are melt-mixed with only one or more PAEK polymers, can be characterized by at least one of the following properties: - Tensile strength of 255 GPa or greater, measured on an ASTM Type I dogbone specimen (length 16.5 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D638 (test speed: 0.5 cm / min); - Bending strength of 370 MPa or higher, measured on a bar (length 12.7 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D790 (test speed: 0.13 cm / min, span 5.1 cm).

[0069] According to further exemplary embodiments, a reinforced PAEK composition obtained by the method of the present invention, in which a chip of CF / PEKK composite material is melt-mixed with a composition comprising PEEK, polyphenylsulfone (PPSU), and polyethersulfone (PES), can be characterized by at least one of the following properties: - Tensile strength of 160 GPa or greater, measured on an ASTM Type I dogbone specimen (length 16.5 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D638 (test speed: 0.5 cm / min); - Bending strength of 235 MPa or higher, measured on a bar (length 12.7 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D790 (test speed: 0.13 cm / min, span 5.1 cm).

[0070] Thus, the present invention makes it possible to manufacture articles made of reinforced PAEK material by using waste CF / PEKK composite material as a raw material. The reinforced PAEK composition is characterized by excellent mechanical properties suitable for the manufacture of high value-added products.

[0071] Reinforced PAEK compositions can be used in industry for the manufacture of various finished products. Therefore, a further object of the present invention is an article made from or containing a reinforced PAEK composition. Articles that can be manufactured from a reinforced PAEK composition require particularly high levels of strength, stiffness, and toughness.

[0072] Advantageously, the article may be an injection-molded article or an extruded article.

[0073] Non-limiting examples of articles include valve seats / seals, pump wear rings, gears and sliding vanes or medical device fixtures, turbines and / or turbine housings for electrical appliances.

[0074] If any disclosure of a patent, patent application, or publication incorporated herein by reference conflicts with the description herein to such an extent that it could obscure the terminology, the description herein shall prevail.

[0075] The present invention will be described in more detail here in relation to the following embodiments, but the purpose is merely illustrative and not to limit the scope of the invention. [Examples]

[0076] material CF / PEKK: APC (PEKK) carbon prepreg commercially available from Cytec Engineered Materials / Cytec Industries Inc., Woodland Park, NJ; contains 64-67% by weight of carbon fiber HexTow® AS4D and 33-36% by weight of PEKK resin (T / I ratio = 72:28; Tg = 155°C, Tm = 335°C).

[0077] CF / PEEK: APC-2(PEEK) commercially available from Cytec Engineered Materials / Cytec Industries Inc., Woodland Park, NJ; contains the following.

[0078] KT880: KetaSpire (registered trademark) KT-880P PEEK (commercially available from Solvay Specialty Polymers USA, LLC), specific melt viscosity in the range of 0.12-0.18 kPa·s (at a temperature of 400°C and 1000 s) -1 It has a shear rate (measured by a capillary rheometer).

[0079] KT890: KetaSpire (registered trademark) KT-890P PEEK (commercially available from Solvay Specialty Polymers USA, LLC), specific melt viscosity in the range of 0.07-0.11 kPa·s (at a temperature of 400°C and 1000 s) -1 It has a shear rate (measured by a capillary rheometer).

[0080] PPSU:RADEL® 5900 PPSU [MFR (365℃ / 5kg) is in the range of 26-36g / 10min] is a polyphenylsulfone (PPSU) homopolymer from Solvay Specialty Polymers USA, LLC.

[0081] PES: Veradel® A-702 NT PES [MFR (380℃ / 2.16kg) is in the range of 65-85g / 10min] is a polyethersulfone (PESU) homopolymer from Solvay Specialty Polymers USA, LLC.

[0082] Shredded CF: Sigrafil(registered trademark) C30 S006 APS from SGL Carbon Fibers, Ltd.

[0083] PEPQ: Aromatic organic phosphonite fusion heat stabilizer available from Hostanox® PEP-Q® and Clariant.

[0084] Zinc oxide: Aktiv® grade, available from Lanxess Corp.

[0085] Basic Procedure Tapes made of CF / PEKK or CF / PEEK material were shredded into chips 5-7 mm long and 3-7 mm wide using a shredder.

[0086] The chips were melt-mixed using a ZSK-26 Coperion twin-screw extruder (12 barrel sections, 26 mm diameter, L / D ratio 48) with virgin PEEK resin (KT880 or KT890), or a composition containing PEEK (KT890), PPSU, and PES, and then injection-molded into test rods for further testing.

[0087] Comparative test specimens were prepared by kneading the same virgin PEEK resin, or a composition of PEEK, PPSU, and PES, with standard shredded carbon fibers to obtain a composition containing the same weight percent of carbon fibers, and then injection molding this composition onto an ASTM test rod.

[0088] Tensile properties were measured using an ASTM Type I dogbone specimen (length 16.5 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D638 (test speed: 0.5 cm / min).

[0089] The bending properties were measured using a bar (length 12.7 cm, width 1.3 cm, thickness 0.32 cm) according to ASTM D790 (test speed: 0.13 cm / min, span 5.1 cm).

[0090] Izod impact resistance (with notch) and Izod impact resistance (without notch) were determined using injection-molded plaques (10.16 cm × 10.16 cm, 0.32 cm thick) according to ASTM test methods D256 and D4812, respectively. The test results are reported in Table 1.

[0091] The data in Table 1 shows that the reinforced PAEK compositions obtained using CF / PEKK composite material chips as a carbon fiber source (Examples 1, 2, and 3) have better mechanical properties compared to the reinforced PAEK compositions obtained from virgin PAEK and virgin carbon fibers (Comparative Examples 1, 3, and 4).

[0092] Unexpectedly, the data also shows that the tensile and flexural strengths of the reinforced PAEK composition obtained using CF / PEKK composite chips (Example 1) were higher than those of the PAEK composition obtained using CF / PEEK composite chips (Comparative Example 2).

[0093] Good mechanical properties can be obtained even when the reinforced PAEK composition contains polymers other than PAEK polymer, particularly PES and PPSU polymers. The reinforced composition of Example 5 exhibits not only higher tensile and flexural strength, but also higher impact strength, compared to the composition of Comparative Example 5, which was prepared using virgin carbon fiber.

[0094] [Table 1]

Claims

1. A method for producing a carbon fiber-reinforced poly(aryl ether ketone) composition, - Prepare a chip of CF / PEKK composite material containing 20 to 80% by weight of PEKK polymer relative to the weight of the CF / PEKK composite material, and - Melt-mix at least one poly(aryl ether ketone) polymer different from the PEKK polymer in the CF / PEKK composite material with the chip. A method that includes this.

2. The method according to claim 1, wherein the CF / PEKK composite material contains 0.01% to 1.00% by weight of diphenylsulfone based on the total weight of the CF / PEKK composite material.

3. The method according to claim 1 or 2, wherein the weight of the chips of the CF / PEKK composite material melt-mixed with at least one poly(aryl ether ketone) is such that the amount of carbon fibers in the carbon fiber-reinforced poly(aryl ether ketone) composition is 5 to 60% by weight of the total weight of the composition.

4. The method according to any one of claims 1 to 3, wherein the melt mixing is performed in an extruder.

5. The method according to any one of claims 1 to 4, wherein mechanical means are used to crush an article made of CF / PEKK composite material into chips.

6. The method according to any one of claims 1 to 5, wherein the at least one poly(aryl ether ketone) is poly(ether ether ketone).

7. The aforementioned poly(etheretherketone) has a melt viscosity of 0.05 to 0.50 kPa·s (at 400°C, 1000 s). －１ The method according to claim 6, having (measured by

8. The method according to any one of claims 1 to 7, wherein the chip of the CF / PEKK composite material is melt-mixed with at least one poly(aryl ether ketone) and at least one polymer different from the at least one poly(aryl ether ketone) polymer and the PEKK polymer in the CF / PEKK composite material.

9. The method according to claim 8, wherein the at least one polymer in the CF / PEKK composite material that is different from the poly(aryl ether ketone) polymer and the PEKK polymer is selected from the group of poly(aryl ether sulfone) polymers.

10. The method according to any one of claims 1 to 9, further comprising the step of forming the carbon fiber-reinforced poly(aryl ether ketone) composition into an article.

11. The method according to any one of claims 1 to 10, wherein the carbon fiber-reinforced poly(aryl ether ketone) composition is in the form of pellets.

12. A method for producing a carbon fiber-reinforced poly(aryl ether ketone) composition, - To prepare an article made of a CF / PEKK composite material containing 20 to 80% by weight of PEKK polymer relative to the weight of the composite material, wherein the CF / PEKK composite material includes a unidirectional continuous fiber reinforced tape manufactured by a melt impregnation process or a slurry process. - A step of crushing the aforementioned article to obtain chips of CF / PEKK composite material, and - Melt-mix at least one poly(aryl ether ketone) polymer different from PEKK in the CF / PEKK composite material with the chip. A method that includes this.

13. A method for producing a carbon fiber-reinforced poly(aryl ether ketone) composition, - To prepare chips made of CF / PEKK composite material, and - Melt-mix at least one poly(aryl ether ketone) polymer different from PEKK in the CF / PEKK composite material with the chip. Includes, A method comprising a CF / PEKK composite material containing 0.01% to 1.00% by weight of diphenylsulfone relative to the total weight of the CF / PEKK composite material.

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