Method for crystallizing highly functional polymers through post-processing and crystalline polymers produced thereby

Abstract

The present invention relates to a method for crystallizing a high-performance polymer through a post-process and a crystalline polymer produced by the method. More specifically, the present invention relates to a method for producing a crystalline polyaryletherketone (PAEK) by heat-treating polyaryletherketone (PAEK) provided in pellet or powder form at a temperature between the glass transition temperature (Tg) and the melting point (Tm).

Description

[Technical field]

[0001] The present invention relates to a method for crystallizing a highly functional polymer through a post-process and a crystalline polymer produced by the method. More specifically, the present invention is characterized in that crystalline polyaryletherketone (PAEK) is produced by heat-treating polyaryletherketone (PAEK) provided in the form of pellets or powder at a temperature between the glass transition temperature (Tg) and the melting point (Tm). [Background technology]

[0002] Polyaryletherketone (PAEK) is a general term for a group of industrial resins that are already well known, and types include polyetherketone, polyetheretherketone, polyetherketoneketone, and copolymers in which polyetherketone and polyetherketoneketone are partially mixed.

[0003] Polyaryletherketone (PAEK) is an ultra-high performance plastic that has high heat resistance and excellent mechanical strength and is widely used in the fields of automobiles, aerospace, energy, and electrical and electronics.

[0004] Among the various polyaryletherketone (PAEK) polymers, polyetherketoneketone (PEKK), represented by the following chemical formula, is widely used as an engineering plastic due to its high heat resistance and excellent strength. Engineering plastics are used in fields such as automobiles, aircraft, electrical and electronic equipment, and machinery, and the range of applications is gradually expanding. [ka]

[0005] As the application range of engineering plastics expands, the environment in which they are used becomes more and more severe, and there is a need for polyetherketoneketone (PEEK) compounds that exhibit improved physical properties. However, polyetherketoneketone (PEEK) tends to be amorphous or have low crystallinity due to the influence of isophthaloyl moiety. Therefore, there are problems with the product color being inconsistent and thermal properties being deteriorated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-224274 A Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present inventors have been researching to solve such problems, and have discovered that when the polyaryletherketone (PAEK)-based polymer is subjected to a post-processing heat treatment at a temperature between the glass transition temperature (Tg) and the melting point (Tm), the crystallinity of the polyaryletherketone (PAEK) can be increased, thereby completing the present invention.

[0008] In this regard, JP2014-224274A discloses a method for producing a polyether ether ketone resin.

[0009] The present invention has been devised to solve the problems of the prior art, and has an object to provide a method for crystallizing polyaryletherketone (PAEK) in the form of pellets or powder, which is amorphous or has a crystallinity of 5% or less.

[0010] Another object of the present invention is to provide a crystalline polyaryletherketone (PAEK) produced through a crystallization method. [Means for solving the problem]

[0011] As a technical means for achieving the above technical object, one aspect of the present invention provides a method for crystallizing polyaryletherketone (PAEK), comprising the steps of: preparing polyaryletherketone (PAEK) in the form of pellets or powder, which is amorphous or has a crystallinity of 5% or less; and heat-treating the prepared polyaryletherketone (PAEK) in an inert gas atmosphere at a temperature between the glass transition temperature (Tg) and the melting point (Tm). Effect of the Invention

[0012] The method for crystallizing polyaryletherketone (PAEK) according to the present invention as described above can have an effect of increasing the crystallinity of polyaryletherketone (PAEK) through a simple method of heat-treating polyaryletherketone (PAEK) in pellet or powder form at a temperature between the glass transition temperature (Tg) and the melting point (Tm) in an inert gas atmosphere.

[0013] In addition, the crystallinity of the polyaryletherketone (PAEK) produced can be controlled by adjusting the temperature, time, and flow rate of the inert gas supplied during the heat treatment.

[0014] In addition, by continuously stirring or vibrating the polyaryletherketone (PAEK) during the heat treatment process, the polyaryletherketone (PAEK) in pellet or powder form can be prevented from caking.

[0015] Finally, by carrying out the heat treatment in an inert gas atmosphere, it is possible to prevent the polyaryletherketone (PAEK) from being oxidized and discolored. [Brief description of the drawings]

[0016] [Figure 1] 1 is a flow chart that illustrates a schematic diagram of a method for crystallizing polyaryletherketone (PAEK) according to one embodiment of the present invention. [Diagram 2] 1 is a photograph showing the caking phenomenon of polyetherketoneketone (PEKK) pellets according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The polyaryletherketone (PAEK) may be a polymer selected from the group consisting of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketoneketone (PEEKK), polyetherketoneetherketoneketone (PEKEKK), polyetheretheretherketone (PEEEK), polyetherdiphenyletherketone (PEDEK), and combinations thereof.

[0018] The polyaryletherketone (PAEK) may have a T:I isomer ratio of 50:50 to 90:10.

[0019] The polyaryletherketone (PAEK) may have a T:I isomer ratio of 60:40 to 85:15.

[0020] The polyaryletherketone (PAEK) may have a T:I isomer ratio of 70:30.

[0021] The polyaryletherketone (PAEK) in pellet or powder form can have a diameter of 1 mm to 10 mm and a length of 1 mm to 10 mm.

[0022] The amorphous or 5% or less crystallinity polyaryletherketone (PAEK) may have a diameter of 2 mm to 4 mm and a length of 3 mm to 5 mm.

[0023] The amorphous polyaryletherketone (PAEK) or polyaryletherketone (PAEK) having a crystallinity of 5% or less can be produced by heat treatment at a temperature of 160°C to 300°C.

[0024] The heat treatment of the polyaryletherketone (PAEK) can be carried out at a temperature of 150°C to 340°C.

[0025] The heat treatment of the polyaryl ether ketone (PAEK) can be carried out at a temperature of 160°C to 280°C.

[0026] The heat treatment of the polyaryl ether ketone (PAEK) can be carried out at a temperature of 160°C to 250°C.

[0027] The heat treatment of the polyaryletherketone (PAEK) can be carried out for 10 minutes or more.

[0028] The heat treatment of the polyaryletherketone (PAEK) can be carried out for 10 to 60 minutes.

[0029] The heat treatment of the polyaryletherketone (PAEK) can be carried out while stirring the polyaryletherketone (PAEK) in pellet or powder form.

[0030] The heat treatment of the polyaryletherketone (PAEK) can be carried out using a spiral elevator that vibrates the polyaryletherketone (PAEK) in pellet or powder form.

[0031] The inert gas may be continuously supplied to the polyaryletherketone (PAEK), and the supply flow rate of the inert gas may be 10 mL / min or more.

[0032] The supply flow rate of the inert gas may be 20 mL / min to 80 mL / min.

[0033] The color difference (Δ) of the prepared polyaryletherketone (PAEK) and the heat-treated polyaryletherketone (PAEK) may be less than 1.8.

[0034] Another aspect of the present invention provides a crystalline polyaryletherketone (PAEK) prepared by the crystallization method.

[0035] The crystallinity of the produced crystalline polyaryletherketone (PAEK) may be 20% or more.

[0036] The crystallinity of the produced crystalline polyaryletherketone (PAEK) may be 30% to 35%.

[0037] In addition, another aspect of the present invention provides an article manufactured by a technique selected from laser sintering, fused deposition modeling, molding, injection molding, extrusion, thermoforming, rotational molding, compression molding, compounding, or impregnation using the crystalline polyaryletherketone (PAEK) manufactured through the crystallization method.

[0038] The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather as defined by the claims set forth below.

[0039] In addition, the terms used in the present invention are only used to describe certain embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In the entire specification of the present invention, 'including' a certain element means that it can further include other elements, not excluding other elements, unless otherwise specified to the contrary.

[0040] A first aspect of the present application provides a method for crystallizing polyaryletherketone (PAEK), comprising the steps of: preparing polyaryletherketone (PAEK) in the form of an amorphous material or in the form of a pellet or powder having a crystallinity of 5% or less; and heat-treating the prepared polyaryletherketone (PAEK) in an inert gas atmosphere at a temperature between the glass transition temperature (Tg) and the melting point (Tm).

[0041] Hereinafter, the method for crystallizing polyaryletherketone (PAEK) according to the first aspect of the present application will be described in detail step by step with reference to Fig. 1. At this time, Fig. 1 is a flow chart showing the method for crystallizing polyaryletherketone (PAEK).

[0042] First, in one embodiment of the present application, the method for crystallizing polyaryletherketone (PAEK) may include the step of preparing polyaryletherketone (PAEK) in the form of an amorphous material or a pellet or powder having a crystallinity of 5% or less; (S100).

[0043] In one embodiment of the present application, the polyaryletherketone (PAEK) may be a polymer selected from the group consisting of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketoneketone (PEEKK), polyetherketoneetherketoneketone (PEKEKK), polyetheretheretherketone (PEEEK), polyetherdiphenyletherketone (PEDEK), and combinations thereof, and is preferably polyetherketoneketone (PEKK). At this time, the polyetherketoneketone (PEKK) is a polymer produced by chain polymerization of a terephthaloyl form represented by the following Chemical Formula 1 and an isophthaloyl form represented by the following Chemical Formula 2, and the characteristics can be determined by the ratio thereof. The terephthaloyl moiety is linear and has a hardness, whereas the isophthaloyl moiety imparts structural diversity through its curved structure, and the isophthaloyl moiety can affect the flexibility, fluidity, and crystallization properties of the polymer chain. In particular, the isophthaloyl moiety increases flexibility or fluidity, but shows a low crystallization rate, so that the polymerized polyetherketoneketone (PEKK) can be amorphous or show a low degree of crystallinity. In this case, if the polyetherketoneketone (PEKK) has a degree of crystallinity, the degree of crystallinity can be 5% or less. [ka] [ka]

[0044] In one embodiment of the present application, the amorphous polyaryletherketone (PAEK) having a crystallinity of 5% or less may be provided in the form of pellets or powder. At this time, the amorphous polyaryletherketone (PAEK) having a crystallinity of 5% or less may be prepared by heat treatment at a temperature of 160°C to 300°C, preferably at a temperature of 160°C to 250°C. Meanwhile, the amorphous polyaryletherketone (PAEK) having a crystallinity of 5% or less may be provided in the form of pellets, and in this case, the pellets may be prepared by extrusion processing in the above temperature range.

[0045] In one embodiment of the present application, the amorphous or 5% or less crystallinity polyaryletherketone (PAEK) may have a T:I isomer ratio of 50:50 to 90:10, preferably 60:40 to 85:15, and according to one embodiment of the present application, 70:30. In this case, the T:I isomer ratio may mean the ratio of isomers represented by Formulas 1 and 2. That is, the amorphous or 5% or less crystallinity polyaryletherketone (PAEK) may include two different isomer forms of ketone-ketone as repeating units. That is, the content of the repeating unit represented by Formula 1 may be equal to or greater than the content of the repeating unit represented by Formula 2, and the higher the content of the repeating unit represented by Formula 1, the higher the crystallinity of the polyaryletherketone (PAEK) containing the repeating unit.

[0046] In one embodiment of the present application, the amorphous or 5% or less crystallinity polyaryletherketone (PAEK) may have a diameter of 1 mm to 10 mm and a length of 1 mm to 10 mm, preferably a diameter of 2 mm to 4 mm and a length of 3 mm to 5 mm. The diameter and length ranges may be provided as suitable sizes for products actually sold.

[0047] Next, in one embodiment of the present application, the method for crystallizing the polyaryletherketone (PAEK) may include a step of heat-treating the prepared polyaryletherketone (PAEK) in an inert gas atmosphere at a temperature between the glass transition temperature (Tg) and the melting point (Tm); (S200).

[0048] In one embodiment of the present application, the heat treatment of the polyaryletherketone (PAEK) may be performed at a temperature of 150°C to 340°C, preferably at a temperature of 160°C to 280°C, and more preferably at a temperature of 160°C to 250°C. That is, the lower limit of the above temperature range may be the glass transition temperature (Tg) of the polyaryletherketone (PAEK), and the upper limit may be the melting point (Tm). In this regard, the glass transition temperature (Tg) and the melting point (Tm) may vary depending on the ratio of T:I isomers contained in the polyaryletherketone (PAEK), and the heat treatment temperature range may be a temperature range that can include the T:I isomer ratio of the amorphous or polyaryletherketone (PAEK) having a crystallinity of 5% or less, which is 50:50 to 90:10. That is, the crystallinity of the polyaryletherketone (PAEK) can be increased by heat-treating the amorphous or 5% or less crystallinity polyaryletherketone (PAEK) in the above temperature range. Meanwhile, when the polyaryletherketone (PAEK) is heated to above the glass transition temperature (Tg), a caking phenomenon of pellets or powder may occur due to an exothermic reaction while crystallizing, and the caking phenomenon occurs less when the heat treatment is performed at a temperature of 160°C to 250°C, preferably 160°C to 200°C. On the other hand, when the heat treatment temperature is increased, the caking phenomenon may occur relatively more, but the crystallinity of the polyaryletherketone (PAEK) can be further increased. FIG. 2 shows a photo of the caking phenomenon of the polyetherketoneketone (PEKK) pellet according to one embodiment of the present invention.

[0049] In one embodiment of the present application, the heat treatment of the polyaryletherketone (PAEK) may be performed for 10 minutes or more, and preferably for 10 to 60 minutes, in which case, the longer the heat treatment time, the more the crystallinity of the polyaryletherketone (PAEK) can be increased.

[0050] In one embodiment of the present application, the heat source for the heat treatment is not particularly limited, but preferably hot air or infrared rays (IR) can be used. At this time, the heat treatment can be performed in a sealed reactor by supplying hot air into the reactor or irradiating infrared rays (IR). More specifically, the reactor may have a certain space therein, and polyaryletherketone (PAEK) in the form of an amorphous material or a pellet or powder having a crystallinity of 5% or less is inserted into the space. Meanwhile, when hot air is used as a heat source, a hot air supply hopper for supplying hot air into the reactor may be separately provided, and the hot air supply hopper may be connected to the reactor through a pipe to supply hot air into the reactor. At this time, the hot air may be supplied through the lower end of the reactor. In addition, a vibration device may be separately installed inside the reactor. In addition, when infrared rays (IR) are used as a heat source, an infrared emitter can be installed in the reactor, and the heat treatment can be performed by the infrared rays emitted from the infrared emitter. In addition, an agitator equipped with an impeller for stirring can be installed inside the reactor, and a stirring motor is connected to one side for the operation of the agitator. In addition, the reactor can be installed so that it can rotate by itself, and in this case, it is installed in a cylindrical shape and can be rotated around its central axis after being placed horizontally. That is, in order to prevent caking, the reactor can use a spiral elevator capable of supplying vibrations or an agitator installed inside. At this time, when the spiral elevator is used, the transfer and crystallization of polyaryletherketone (PAEK) are performed simultaneously.

[0051] In one embodiment of the present application, the heat treatment of the polyaryletherketone (PAEK) can be performed while stirring the polyaryletherketone (PAEK) in pellet or powder form. This is a process that is performed to prevent the caking of the pellet or powder that may occur due to an exothermic reaction during crystallization when the polyaryletherketone (PAEK) is heat-treated at a temperature above the glass transition temperature (Tg) as described above.

[0052] In one embodiment of the present application, the heat treatment can be performed by placing the polyaryletherketone (PAEK) in pellet or powder form in a sealed reactor as described above. In this case, the agitation can be performed by using a general agitator or by rotating the reactor. That is, when the agitator is used, the impeller can continuously apply physical impact to the polyaryletherketone (PAEK) in pellet or powder form, thereby preventing caking, and when the reactor is rotated, the polyaryletherketone (PAEK) in pellet or powder form also continuously rotates with the reactor, thereby preventing caking. At this time, the agitator and the rotation of the reactor can be used simultaneously.

[0053] In one embodiment of the present application, the inert gas may be continuously supplied to the polyaryletherketone (PAEK). By continuously supplying the inert gas during the heat treatment process, the polyaryletherketone (PAEK) may be prevented from being oxidized, and thus the polyaryletherketone (PAEK) may be prevented from being discolored. In this case, the inert gas may be a commonly known inert gas, such as nitrogen (N2), argon (Ar), or helium (He).

[0054] In one embodiment of the present application, the heat treatment may be performed by placing the polyaryletherketone (PAEK) in pellet or powder form in a sealed reactor, in which the inert gas is continuously supplied into the reactor, at a flow rate of 10 mL / min or more, preferably 20 mL / min to 80 mL / min.

[0055] In one embodiment of the present application, the color difference (△) of the prepared polyaryletherketone (PAEK) and the heat-treated polyaryletherketone (PAEK) may be less than 1.8, preferably 0.7 or less, more preferably 0.5 or less, and most preferably 0.1. The color difference of the prepared polyaryletherketone (PAEK) and the heat-treated polyaryletherketone (PAEK) is related to the flow rate of the inert gas continuously supplied, and the color difference value decreases as the flow rate of the inert gas supplied increases. In other words, a small color difference means that the proportion of the polyaryletherketone (PAEK) that is oxidized during heat treatment is small, and this can mean that the degree of discoloration is small.

[0056] A second aspect of the present application provides a crystalline polyaryletherketone (PAEK) produced by the crystallization method of the first aspect of the present application.

[0057] A third aspect of the present application provides an article manufactured using the crystalline polyaryletherketone (PAEK) manufactured through the crystallization method of the first aspect of the present application by a technique selected from laser sintering, fused deposition modeling, molding, injection molding, extrusion, thermoforming, rotational molding, compression molding, compounding, or impregnation.

[0058] Detailed descriptions of parts that overlap with the first aspect of the present application have been omitted, but the contents described with respect to the first aspect of the present application can be equally applied to the second and third aspects even if the descriptions are omitted.

[0059] The crystalline polyaryletherketone (PAEK) according to the second aspect of the present application and the article according to the third aspect of the present application are described in detail below.

[0060] In one embodiment of the present application, the crystalline polyaryletherketone (PAEK) may have an increased crystallinity compared to amorphous polyaryletherketone (PAEK) having a crystallinity of 5% or less prepared before the crystallization method is performed. In other words, by obtaining a crystalline polyaryletherketone (PAEK) having a high crystallinity, the thermal properties of the polyaryletherketone (PAEK) may be improved.

[0061] In one embodiment of the present application, the crystallinity of the prepared crystalline polyaryletherketone (PAEK) may be 20% or more, preferably 28% to 35%, and most preferably 30% to 35%. In this case, the crystallinity of the prepared crystalline polyaryletherketone (PAEK) may be related to the temperature and time of the heat treatment according to the first aspect of the present application. Specifically, the crystallinity can increase as the temperature and time of the heat treatment increase. A detailed description of this has been provided in the first aspect of the present application, and therefore, a detailed description will be omitted in the following second aspect of the present application.

[0062] In one embodiment of the present application, the produced crystalline polyaryletherketone (PAEK) can be obtained in pellet or powder form, from which articles can be manufactured using techniques selected from laser sintering, fused deposition modeling, molding, injection molding, extrusion, thermoforming, rotational molding, compression molding, compounding, or impregnation.

[0063] In one embodiment of the present application, wet impregnation for producing pre-impregnated composite strips, also called tapes, can be carried out by depositing, for example, an aqueous dispersion of polyaryletherketone (PAEK) pellets (powder) and phosphate salts on carbon or glass fibers. More specifically, said dispersion can, for example, comprise polyetherketoneketone (PEKK) pellets (powder) and phosphate salts and surfactants in an aqueous solution. The fibers covered with the aqueous dispersion then pass through an oven that evaporates the water, after which they pass through a die at high temperature (usually above 370° C.) to allow the stabilized polyetherketoneketone (PEKK) polymer to melt and coat the fibers precisely. After cooling, a tape or pre-impregnated strip is obtained, which can then be used by assembling and / or superimposing to remelt it and form a composite article.

[0064] In one embodiment of the present application, the main advantage of the phosphate salts is that they do not release volatile organic compounds, but simply lose water in the form of steam, even when heated to very high temperatures (e.g., above 350° C.), and therefore do not pose any environmental and / or health hazards and do not create porosity that may interfere with the coating of fibers or cause defects in the final manufactured article, subsequently leading to a deterioration of mechanical properties.

[0065] Although the present invention has been described in detail above with reference to the drawings and preferred embodiments, the scope of the technical idea of ​​the present invention is not limited to these drawings and embodiments. Therefore, various modifications or equivalent embodiments may exist within the scope of the technical idea of ​​the present invention. Therefore, the scope of the technical idea of ​​the present invention should be interpreted according to the claims, and any technical idea equivalent to or within the equivalent scope should be interpreted as belonging to the scope of the present invention.

[0066] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein. EXAMPLES

[0067] Example 1. Preparation of crystalline polyetherketoneketone (PEKK) 1. Production of amorphous polyetherketoneketone (PEKK) Polyetherketoneketone (PEKK) granules having a T:I isomer ratio of 70:30 were extruded in an extruder at a temperature of 160°C to 300°C, preferably 160°C to 250°C, and the extrudate was cut to obtain amorphous polyetherketoneketone (PEKK) in pellet form. The diameter of the obtained polyetherketoneketone (PEKK) pellets was 2mm to 4mm and the length was 3mm to 5mm. The obtained polyetherketoneketone (PEKK) pellets were in an amorphous state and showed a crystallinity of 0% to 5%.

[0068] 2. Production of crystalline polyetherketoneketone (PEKK) The polyetherketoneketone (PEKK) pellets obtained in 1 were inserted into a reactor equipped with an internal stirrer, and heat-treated while continuously purging with nitrogen to obtain crystalline polyetherketoneketone (PEKK). The heat treatment temperature was 160°C, and the heat treatment was performed for 30 minutes. The flow rate of the nitrogen purge was 80 mL / min. The heat treatment temperature was measured using a DSC2500 model manufactured by TA Instruments.

[0069] Example 2. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 190°C.

[0070] Example 3. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 220°C.

[0071] Example 4. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 250°C.

[0072] Example 5. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 280°C.

[0073] Example 6. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 220° C. and the heat treatment time was changed to 10 minutes.

[0074] Example 7. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 250° C. and the heat treatment time was changed to 10 minutes.

[0075] Example 8. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 250° C. and the nitrogen purge flow rate was changed to 20 mL / min.

[0076] Example 9. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 250° C. and the nitrogen purge flow rate was changed to 50 mL / min.

[0077] Comparative Example 1. Preparation of crystalline polyetherketoneketone (PEKK) Crystalline polyetherketoneketone (PEKK) was obtained in the same manner as in Example 1, except that the heat treatment temperature was changed to 250° C. and nitrogen purging was not performed.

[0078] Experimental Example 1. Measurement of crystallinity of polyetherketoneketone (PEKK) depending on heat treatment temperature In order to compare the crystallinity of polyetherketoneketone (PEKK) depending on the heat treatment temperature, the crystallinity of the polyetherketoneketone (PEKK) obtained in Examples 1 to 5 was measured and is shown in Table 1 below. [Table 1]

[0079] As shown in Table 1, it was confirmed that the crystallinity of the resulting polyetherketoneketone (PEKK) increases as the heat treatment temperature increases. However, it was confirmed that the caking phenomenon gradually increases at temperatures above the glass transition temperature (Tg) and becomes severe above 200°C.

[0080] Experimental Example 2. Measurement of crystallinity of polyetherketoneketone (PEKK) depending on heat treatment time In order to compare the crystallinity of polyetherketoneketone (PEKK) depending on the heat treatment time, the crystallinity of the polyetherketoneketone (PEKK) obtained in Examples 3, 4, 6 and 7 was measured and is shown in Table 2 below. [Table 2]

[0081] As shown in Table 2, it was confirmed that the crystallinity of the resulting polyetherketoneketone (PEKK) increased slightly as the heat treatment time increased. However, it was confirmed that the heat treatment temperature has a greater effect on the crystallinity of the polyetherketoneketone (PEKK) than the heat treatment time.

[0082] Experimental Example 3. Color difference measurement of polyetherketoneketone (PEKK) with nitrogen purge flow rate In order to compare the color difference of polyetherketoneketone (PEKK) depending on the purge flow rate of nitrogen, which is an inert gas, during heat treatment, the color differences of polyetherketoneketone (PEKK) according to Comparative Example 1 and Examples 4, 8, and 9 were compared and shown in the following Table 3. At this time, a Nippon Denshoku NE4000 color difference meter was used to measure the color difference, and the color difference of polyetherketoneketone (PEKK) before and after heat treatment was measured. [Table 3]

[0083] As shown in Table 3, in the comparative example where no nitrogen purging was performed, the color difference value was 1.8, which was a level that could be distinguished by appearance. On the other hand, as the flow rate of purged nitrogen increased, the color difference value decreased, and it was confirmed that in Example 4 where nitrogen was supplied at 80 mL / min, the color difference value was 0.1. Therefore, it was confirmed that the supply of inert gas during heat treatment is essential for the performance and quality of the obtained product. [Industrial Applicability]

[0084] The method for crystallizing polyaryletherketone (PAEK) according to the present invention as described above can have an effect of increasing the crystallinity of polyaryletherketone (PAEK) through a simple method of heat-treating polyaryletherketone (PAEK) in pellet or powder form at a temperature between the glass transition temperature (Tg) and the melting point (Tm) in an inert gas atmosphere.

[0085] In addition, the crystallinity of the polyaryletherketone (PAEK) produced can be controlled by adjusting the temperature, time, and flow rate of the inert gas supplied during the heat treatment.

[0086] In addition, by continuously stirring or vibrating the PAEK during the heat treatment, the PAEK in pellet or powder form can be prevented from caking.

[0087] Finally, by carrying out the heat treatment in an inert gas atmosphere, it is possible to prevent the polyaryletherketone (PAEK) from being oxidized and discolored.

Claims

1. Providing a polyaryletherketone (PAEK) in pellet or powder form that is amorphous or has a crystallinity of 5% or less; and heat-treating the prepared polyaryletherketone (PAEK) at a temperature between a glass transition temperature (Tg) and a melting point (Tm) in an inert gas atmosphere; Including, the inert gas is continuously fed to the polyaryletherketone (PAEK); The supply flow rate of the inert gas is 20 mL / min to 80 mL / min, The heat-treated polyaryletherketone (PAEK) has a color difference (△) of 0.7 or less and a crystallinity of 30% to 35%.

2. 2. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the polyaryletherketone (PAEK) is a polymer selected from the group consisting of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketoneketone (PEEKK), polyetherketoneetherketoneketone (PEKEKK), polyetheretheretherketone (PEEEK), polyetherdiphenyletherketone (PEDEK), and combinations thereof.

3. 2. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the polyaryletherketone (PAEK) has a T:I isomer ratio of 50:50 to 90:

10.

4. 2. The method of claim 1, wherein the polyaryletherketone (PAEK) has a T:I isomer ratio of 70:

30.

5. The polyaryletherketone (PAEK) in pellet or powder form is 2. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, having a diameter of 1 mm to 10 mm and a length of 1 mm to 10 mm.

6. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the amorphous or polyaryletherketone (PAEK) having a crystallinity of 5% or less is produced by heat treatment at a temperature of 160°C to 300°C.

7. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out at a temperature of 150°C to 340°C.

8. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out at a temperature of 160°C to 280°C.

9. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out at a temperature of 160°C to 250°C.

10. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out for 10 minutes or more.

11. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out for 10 minutes to 60 minutes.

12. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out by stirring the polyaryletherketone (PAEK) in pellet or powder form.

13. The method for crystallizing polyaryletherketone (PAEK) according to claim 1, wherein the heat treatment of the polyaryletherketone (PAEK) is carried out using a spiral elevator that vibrates the polyaryletherketone (PAEK) in pellet or powder form.

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