Modified PEEK composition as well as preparation method and application thereof

Abstract

The invention discloses a modified PEEK (polyether-ether-ketone) composition as well as a preparation method and application thereof. The composition comprises PEEK resin, a nucleating agent and an additive. The content of the polyether-ether-ketone (PEEK) resin is 30.0-99.0 wt%, the content of the nucleating agent is 0.01-10.0 wt%, and the nucleating agent is an inorganic nucleating agent and / or an organic metal phosphate nucleating agent; according to the composition, the linear expansion coefficient of the composition can be remarkably reduced, the thermal deformation temperature is increased, and the forming efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, specifically to a modified PEEK composition, its preparation method, and its application. Background Technology

[0002] PEEK (polyetheretherketone) is a novel semi-crystalline, thermoplastic aromatic polymer material. It is the most important and widely used thermoplastic engineering plastic among polyaryletherketone (PAEK) varieties. Its crystal structure belongs to the orthorhombic crystal system, with a melting point as high as 340℃. It maintains high mechanical properties for extended periods even at 200℃, and also possesses excellent chemical stability, high-temperature thermal stability, and biocompatibility. Modified PEEK compositions further expand its application areas. Currently, PEEK and modified PEEK compositions are widely used in aerospace, electronics, automotive, energy, and medical fields.

[0003] PEEK is a semi-crystalline polymer, and its final properties (especially dimensional stability, heat resistance, and molding efficiency) largely depend on its crystallinity and crystallization behavior. Generally, higher crystallinity results in smaller grain sizes, better mechanical properties, and higher tensile strength. During processing and use, PEEK and its composite materials have high glass transition temperatures and melting points, and relatively slow crystallization rates. This necessitates longer holding pressure and cooling times during molding (especially injection molding and compression molding) to ensure sufficient crystallization, or post-processing to ensure adequate crystallization of the finished product to meet dimensional and application requirements.

[0004] However, in rapid prototyping or complex products, excessively rapid cooling rates can lead to low or uneven crystallinity, resulting in insufficient crystallinity and affecting product performance. Furthermore, insufficient or uneven crystallinity can cause significant shrinkage or dimensional changes during post-processing (such as annealing) or high-temperature use, impacting precision and reliability. Moreover, PEEK with low crystallinity has a lower heat distortion temperature (HDT) and upper limit for long-term service temperature, and longer cooling / crystallization times also make it difficult to improve the molding efficiency of PEEK materials.

[0005] The commonly used method is to improve the situation by increasing the mold temperature or extending the cooling time, but this directly sacrifices production efficiency and increases energy consumption. Summary of the Invention

[0006] The present invention aims to solve the technical problems in the background art and provide a modified PEEK composition that can significantly reduce the linear expansion coefficient of the composition, increase the heat distortion temperature, and improve the molding efficiency.

[0007] Specifically, it includes polyetheretherketone (PEEK) resin, nucleating agent, and additives.

[0008] The components, calculated on a 100wt% basis, contain 30.0-99.0wt% polyetheretherketone (PEEK) resin.

[0009] The nucleating agent content is 0.01-10.0 wt%, preferably 0.05-5.0 wt%, and more preferably 0.1-2.0 wt%.

[0010] The nucleating agent is an inorganic nucleating agent and / or an organometallic phosphate nucleating agent; more preferably, it is a mixture of an inorganic nucleating agent and an organometallic phosphate nucleating agent. The inorganic nucleating agent is selected from any one or a combination of talc powder and nano-calcium carbonate; the organometallic phosphate nucleating agent is selected from any one or a combination of sodium benzoate and sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate.

[0011] The additive comprises one or more of the following additives:

[0012] Reinforcing agents: glass fiber, carbon fiber, mineral fiber, aramid fiber, and other reinforcing materials;

[0013] Lubricants: polytetrafluoroethylene, silicone, graphite;

[0014] Stabilizers: antioxidants, heat stabilizers, ultraviolet absorbers;

[0015] Coloring agent: pigment or dye.

[0016] The total weight of the nucleating agent as a percentage of the total weight of the modified PEEK composition is 0.01–10.0 wt%.

[0017] Another aspect of the present invention provides a method for preparing a modified PEEK composition, comprising:

[0018] S1. Weigh the PEEK resin powder or granules, nucleating agent and additives according to the proportion.

[0019] S2. Perform premixing to ensure initial uniform dispersion;

[0020] S3. The premixed material is fed into an extruder for melt blending, extrusion, and granulation.

[0021] S4. The extruded melt is cooled in a water bath and pelletized to obtain the modified PEEK composition particles.

[0022] The present invention also provides the application of the above-described modified PEEK composition in electronic and electrical connectors, automotive engine parts, pump and valve parts, and medical device parts.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) The nucleating agent effectively increases the number of crystal nuclei, enabling PEEK to achieve a higher final crystallinity in the same or even shorter cooling time (which can be calculated by measuring the melting enthalpy ΔHm of crystallization using DSC). High crystallinity directly leads to higher strength, modulus, hardness, and solvent resistance.

[0025] (2) The nucleating agent significantly reduces the supercooling required for crystallization and significantly shortens the crystallization half-life (which can be determined by DSC during isothermal crystallization).

[0026] (3) Due to the accelerated crystallization speed, the holding pressure and cooling time can be significantly shortened during injection molding, compression molding and other molding processes (for example, by 30%-60% or even more), thereby significantly shortening the overall molding cycle, improving equipment utilization and capacity, and reducing production costs.

[0027] (4) Higher crystallinity and more perfect crystal morphology (smaller spherulite size, more uniform crystals) means that the volume shrinkage (mainly crystallization shrinkage) of the product from the molding temperature to room temperature is completed more fully in the mold, significantly reducing post-shrinkage after demolding.

[0028] (5) High crystallinity means a lower proportion of amorphous regions. At temperatures above Tg, the dimensional changes (thermal expansion and creep) caused by the movement of molecular chains in amorphous regions are significantly suppressed, and the products have better dimensional retention under high temperature conditions.

[0029] (6) High crystallinity significantly improves the material’s resistance to deformation under load. Its heat distortion temperature (HDT@1.82MPa or 0.45MPa) can approach or even exceed the Tg of PEEK (~143℃), reaching a level far higher than that of pure amorphous polymers (e.g., increased to above 250°C or even higher).

[0030] (7) Smaller spherulite size (nucleating agents usually lead to spherulite refinement) may help improve the surface gloss of the product and reduce surface defects.

[0031] (8) With proper selection of nucleating agent type and dosage, the above-mentioned properties can be significantly improved while maintaining the good core mechanical properties of PEEK such as toughness and impact strength. Minimal modifications are required to existing PEEK processing equipment (extruders, injection molding machines) and processes, making industrial production and application easy. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0033] In the following embodiments, the preliminary preparations are as follows:

[0034] The raw material is polyetheretherketone resin, abbreviated as PEEK (the raw material is G series-330G PEEK pure resin granules from Jilin Zhongyan Polymer Materials Co., Ltd.).

[0035] The test methods described in these embodiments all adopt ISO standards.

[0036] Example 1

[0037] The following components were premixed to ensure uniform initial dispersion: 97.5 wt% PEEK, 1.5 wt% sodium benzoate, 0.3 wt% butylated hydroxytoluene (2,6-di-tert-butyl-p-cresol) antioxidant, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine antioxidant, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide. The premixed material was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0038] Example 2

[0039] The following ingredients were premixed: 98.8 wt% PEEK, 0.2 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0040] Example 3

[0041] The following ingredients were premixed: 97.2 wt% PEEK, 1.3 wt% sodium benzoate, 0.5 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0042]

[0043] The performance comparison of the pure PEEK material system is as follows: Within the pure PEEK system, the crystallization peak temperature increases by 20℃, the crystallinity increases by 13%, and the linear expansion coefficient decreases from 120ppm / K to 80ppm / K, thereby improving the dimensional stability of the material parts, reducing the influence of temperature changes on the material, and improving the dimensional stability of the product; the crystallization peak temperature increases by 20℃, the crystallinity increases by 13%, and the heat distortion temperature increases from 156℃ to 172℃, thereby improving the heat resistance of the pure PEEK material; the crystallization peak temperature increases by 20℃, and the half-crystallization time decreases from 73.3 seconds to 38 seconds, which is beneficial to improving the molding efficiency of the pure PEEK material.

[0044] Example 4

[0045] The following ingredients were premixed to ensure uniform initial dispersion: 67 wt% PEEK, 30 wt% glass fiber, 2 wt% sodium benzoate, 0.3 wt% butylated hydroxytoluene (2,6-di-tert-butyl-p-cresol) antioxidant, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine antioxidant, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide. The premixed material was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0046] Example 5

[0047] The following components were premixed: 67.4 wt% PEEK, 30 wt% glass fiber, 1.6 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0048] Example 6

[0049] The following ingredients were premixed to ensure uniform initial dispersion: 67 wt% PEEK, 30 wt% glass fiber, 0.5 wt% sodium benzoate, 1.5 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide. The premix was then fed into an extruder for melt blending and granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0050]

[0051] The performance comparison between PEEK material and the 30% glass fiber reinforced system is as follows. In the glass fiber reinforced PEEK composite system, the added nucleating agent dosage is higher, resulting in a 24°C increase in crystallization peak temperature, an 11% increase in crystallinity, and a decrease in the linear expansion coefficient from 22ppm / K to 15ppm / K. This improves the dimensional stability of the material parts, reduces the impact of temperature changes, and enhances the dimensional stability of the product. The 24°C increase in crystallization peak temperature and 11% increase in crystallinity also raise the heat distortion temperature from 333°C to 342°C, thereby improving the heat resistance of the glass fiber reinforced PEEK composite. The 24°C increase in crystallization peak temperature and the decrease in half-crystallization time from 65 seconds to 28 seconds are beneficial for improving the molding efficiency of the glass fiber reinforced PEEK composite.

[0052] Example 7

[0053] The following ingredients were premixed to ensure uniform initial dispersion: 89 wt% PEEK, 10 wt% carbon fiber, 2 wt% sodium benzoate, 0.3 wt% antioxidant butylated hydroxytoluene 2,6-di-tert-butyl-p-cresol, 0.4 wt% antioxidant N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide. The premixed material was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0054] Example 8

[0055] The following components were premixed: 87 wt% PEEK, 10 wt% carbon fiber, 1.5 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0056] Example 9

[0057] The following ingredients were premixed to ensure uniform initial dispersion: 85 wt% PEEK, 10 wt% carbon fiber, 2 wt% sodium benzoate, 2 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide. The premix was then fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0058]

[0059] The performance comparison between PEEK material and the 10% carbon fiber reinforced system is as follows. In the carbon fiber reinforced PEEK composite system, the added nucleating agent dosage is higher, resulting in a 10°C increase in crystallization peak temperature, an 11% increase in crystallinity, and a decrease in the linear expansion coefficient from 82ppm / K to 30ppm / K. This improves the dimensional stability of the material parts, reduces the impact of temperature changes, and enhances the dimensional stability of the product. The 10°C increase in crystallization peak temperature and 11% increase in crystallinity also improve the heat distortion temperature from 245°C to 261°C, thereby improving the heat resistance of the glass fiber reinforced PEEK composite. The 10°C increase in crystallization peak temperature also reduces the half-crystallization time from 68 seconds to 27 seconds, which is beneficial for improving the molding efficiency of the glass fiber reinforced PEEK composite.

[0060] Example 10

[0061] 77 wt% PEEK, 20 wt% polytetrafluoroethylene, 2 wt% sodium benzoate, 0.3 wt% butylated hydroxytoluene (2,6-di-tert-butyl-p-cresol) antioxidant, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine antioxidant, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide were premixed to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0062] Example 11

[0063] The following components were premixed: 77.4 wt% PEEK, 20 wt% polytetrafluoroethylene, 1.6 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide to ensure initial uniform dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0064] Example 12

[0065] 77 wt% PEEK, 20 wt% polytetrafluoroethylene, 0.5 wt% sodium benzoate, 1.5 wt% sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, 0.3 wt% butylhydroxytoluene-2,6-di-tert-butyl-p-cresol, 0.4 wt% N,N'-bis-(β-naphthyl)-p-diamine, 0.2 wt% calcium stearate, and 0.1 wt% vinyl bis-stearamide were premixed to ensure uniform initial dispersion. The premix was fed into an extruder for melt blending and extrusion granulation. The extruded melt was cooled in a water bath and pelletized to obtain the modified PEEK composition granules.

[0066]

[0067] The performance comparison of PEEK wear-resistant composite materials is as follows. In the PEEK abrasion-resistant composite material system, the addition of a larger amount of nucleating agent results in a 16°C increase in crystallization peak temperature, a 10% increase in crystallinity, and a decrease in the linear expansion coefficient from 122ppm / K to 65ppm / K. This improves the dimensional stability of the material parts, reduces the impact of temperature changes on the material, and enhances the dimensional stability of the product. The 16°C increase in crystallization peak temperature and 10% increase in crystallinity also improve the heat distortion temperature from 149°C to 185°C, thereby improving the heat resistance of glass fiber reinforced PEEK composite materials. The 16°C increase in crystallization peak temperature also reduces the half-crystallization time from 186 seconds to 40 seconds, which is beneficial for improving the molding efficiency of glass fiber reinforced PEEK composite materials.

[0068] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A modified PEEK composition, characterized in that, The components of the composition, calculated on a 100wt% basis, are: polyetheretherketone resin content of 30.0-99.0wt%, nucleating agent content of 0.01-10.0wt%, and the balance being additives; the nucleating agent is an inorganic nucleating agent and / or an organometallic phosphate nucleating agent.

2. The modified PEEK composition according to claim 1, characterized in that, The inorganic nucleating agent is selected from any one or a combination of talc powder and nano-calcium carbonate.

3. The modified PEEK composition according to claim 1, characterized in that, The organometallic phosphate nucleating agent is selected from any one or combination of sodium benzoate and sodium 2,2'-methylene bis(4,6-di-tert-butylphenyl) phosphate.

4. The modified PEEK composition according to claim 1, characterized in that, The additives are selected from any one or a combination of reinforcing agents, lubricants, stabilizers, and colorants.

5. The modified PEEK composition according to claim 4, characterized in that, The reinforcing agent is selected from any one of glass fiber, carbon fiber, mineral fiber, and aramid fiber; the lubricant is selected from any one of polytetrafluoroethylene, silicone, and graphite; the stabilizer is selected from any one of antioxidants, heat stabilizers, and ultraviolet absorbers; and the colorant is selected from any one of pigments and dyes.

6. A method for preparing a modified PEEK composition according to any one of claims 1-5, characterized in that, The preparation method includes: S1. Weigh the PEEK resin powder or granules, nucleating agent and additives according to the proportion. S2. Perform premixing to ensure initial uniform dispersion; S3. The premixed material is fed into an extruder for melt blending, extrusion, and granulation. S4. The extruded melt is cooled in a water bath and pelletized to obtain the modified PEEK composition particles.

7. The application of a modified PEEK composition according to any one of claims 1-6 in electronic and electrical connectors, automotive engine parts, pump and valve parts, and medical device parts.

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