Special LCP (Liquid Crystal Polymer) compound for 3D (Three-Dimensional) printing and preparation method thereof

Abstract

The invention belongs to the technical field of 3D printing, and discloses a special LCP (Liquid Crystal Polymer) compound for 3D printing and a preparation method thereof, and the special LCP compound for 3D printing is prepared by melting and extruding an oligomer with the molecular weight of 5000-20000 and LCP; the mass ratio of the oligomer to the LCP is (5-40): (50-95), and the LCP compound special for 3D printing has the advantages that the oligomer with high flowability in a molten state is mixed with the LCP in the molten state, so that on one hand, the bottom sticking effect of the LCP in the 3D printing process is improved, and the theoretical size of a 3D printing substance is increased; on the other hand, by adding the low polymer, the interlayer acting force of the LCP is improved, and the structural strength of the product is further improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of 3D printing, in particular to a LCP compound special for 3D printing and a preparation method thereof. BACKGROUND

[0002] With the continuous development of 3D printing technology, the performance requirements of printing consumables are also increasing. In many industrial fields such as aerospace, automobile manufacturing, electronic equipment, etc., 3D printing consumables capable of resisting high temperature environment are needed. Traditional 3D printing consumables have deficiencies in high temperature resistance and cannot meet the needs of these fields.

[0003] Liquid crystal polymer (LCP) has excellent electrical insulation performance, chemical corrosion resistance and heat resistance, and is one of the ideal materials for preparing high-temperature-resistant 3D printing consumables. However, pure LCP has some problems in the 3D printing process, such as poor adhesion to the substrate and weak interlayer force affecting the stability of the printed structure. Therefore, it is of great practical significance to develop a high-performance high-temperature-resistant particulate 3D printing consumable.

[0004] The problem to be solved by the present application is to provide a LCP compound special for 3D printing with good interlayer force. SUMMARY

[0005] The purpose of the present application is to provide a LCP compound special for 3D printing with good interlayer force. The LCP compound special for 3D printing is prepared by mixing an oligomer with high fluidity in a molten state with LCP in a molten state. On the one hand, it improves the adhesion to the substrate during the 3D printing process, increases the theoretical size of the 3D printed product, and prevents the decline of the stability of the product during the printing process due to poor adhesion to the substrate. On the other hand, by adding the oligomer, the interlayer force of the LCP is improved, further improving the structural strength of the product itself.

[0006] To achieve the above-mentioned purpose, the present application discloses a LCP compound special for 3D printing, which is prepared by mixing an oligomer with a molecular weight of 5000-20000 and LCP in a molten state and extruding.

[0007] The mass ratio of the oligomer to LCP is 5-40:50-95.

[0008] Preferably, the oligomer is selected from at least one of polyether ether ketone, polyether ketone ketone, polyphenylene sulfide, polyimide, polysulfone and polyarylate.

[0009] Preferably, the oligomer is a mixture of polyether ether ketone, polyarylate and polyimide, and the mass ratio of polyether ether ketone, polyarylate and polyimide is 5-7:3-5:1-3.

[0010] Preferably, a resin compatibilizer is further added, and the mass ratio of the oligomer, the resin compatibilizer and the LCP is 5-40:0.1-10:50-95;

[0011] The resin compatibilizer comprises a polymer main chain and active groups connected to the polymer main chain;

[0012] The polymer main chain is selected from any one of polyamide, polyimide and polylactic acid;

[0013] The active groups are selected from any one of hydroxyl, amino, epoxy and maleic anhydride.

[0014] Preferably, a fiber reinforcing material is further added in the LCP compound special for 3D printing, and the fiber reinforcing material is selected from at least one of carbon fiber, glass fiber, metal fiber and polymer fiber.

[0015] Preferably, the mass ratio of the fiber reinforcing material and the LCP is 10-30:70-90.

[0016] In addition, the application further discloses a preparation method for preparing the LCP compound special for 3D printing, melting the LCP and mixing the LCP with the oligomer, and then extruding the LCP compound special for 3D printing by using an extruder.

[0017] Preferably, the method comprises the following steps:

[0018] Step 1: melting the LCP and mixing the LCP with the resin compatibilizer and the oligomer to obtain a mixture;

[0019] Step 2: extruding and granulating the mixture by using a double-screw extruder to obtain the LCP compound special for 3D printing;

[0020] In step 2, the temperature of the double-screw extruder is 280-320℃, and the screw rotation speed is 250-300 r / min.

[0021] Preferably, step 1 is specifically melting the LCP and mixing the LCP with the resin compatibilizer, the oligomer and the fiber reinforcing material to obtain the mixture.

[0022] The application has the following beneficial effects:

[0023] The application provides a 3D printing special LCP compound with good interlayer action force, which is obtained by mixing LCP in a molten state with an oligomer with high fluidity and extruding, on the one hand, the oligomer with high fluidity can improve the bottom sticking effect of LCP in the 3D printing process, increase the theoretical size of the 3D printing material, prevent the decline of product stability in the printing process due to poor bottom sticking effect, on the other hand, by adding the oligomer, the interlayer action force of LCP is improved, and the structural strength of the product itself is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FDM 3D printing consumables effect diagram prepared from the 3D printing special LCP compound;

[0025] Figure 2 Pentagonal pen barrel model printed by the 3D printing special LCP compound;

[0026] Figure 3 Sample effect diagram printed by the 3D printing special LCP compound. DETAILED DESCRIPTION

[0027] The application will be clearly and completely described below in combination with the embodiments of the application, and in the description of the application, it should be noted that the specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not marked with the manufacturer are all conventional products that can be purchased on the market.

[0028] Before the display of the embodiments, the following necessary explanations are given to the preparation and acquisition ways of the raw materials involved in the embodiments:

[0029] LCP: purchased from Japan Boli Plastic Group, molecular weight is 80000±1000;

[0030] Polyether ether ketone: molecular weight is 3000-17000;

[0031] Polyether ketone ketone: molecular weight is 5000-15000;

[0032] Polyphenylene sulfide: molecular weight is 3500-6000;

[0033] Polysulfone: molecular weight is 5300-18000;

[0034] Polyarylate: molecular weight is 7300-17000;

[0035] Polyimide: molecular weight is 5800-19000, all supplied by Shenzhen Kangxun New Material Technology Co., Ltd.;

[0036] Maleic anhydride grafted polylactic acid (PLA-g-MAH): purchased from Dongguan Nabichuan Plastic Co., Ltd.

[0037] Example 1

[0038] Step 1: 60 g of LCP was weighed and heated to 300±10℃ to melt, then 32 g of polyether ether ketone (molecular weight 9000±500) was added and mixed to obtain a mixture;

[0039] Step 2: The mixture prepared in step 1 was added to a twin-screw extruder for extrusion granulation, and the temperature of the extruder was set to 280℃ and the screw speed was 250 r / min, to obtain a high-temperature-resistant granular 3D printing consumable.

[0040] Example 2

[0041] Step 1: 50 g of LCP was weighed and heated to 300±10℃ to melt, then 40 g of polyether ether ketone (molecular weight 5000±500) was added and mixed to obtain a mixture;

[0042] Step 2: The mixture prepared in step 1 was added to a twin-screw extruder for extrusion granulation, and the temperature of the extruder was set to 320℃ and the screw speed was 300 r / min, to obtain a high-temperature-resistant granular 3D printing consumable.

[0043] Example 3

[0044] Step 1: 95 g of LCP was weighed and heated to 300±10℃ to melt, then 5 g of polyether ether ketone (molecular weight 16000±800) was added and mixed to obtain a mixture;

[0045] Step 2: The mixture prepared in step 1 was added to a twin-screw extruder for extrusion granulation, and the temperature of the extruder was set to 300℃ and the screw speed was 280 r / min, to obtain a high-temperature-resistant granular 3D printing consumable.

[0046] Example 4

[0047] The same as example 1, the difference is that step 1 is specifically: 60 g of LCP is weighed and heated to 300±10℃ to melt, then 21.3 g of polyarylate (molecular weight 9000±500) and 10.7 g of polyimide (molecular weight 9000±500) are added and mixed to obtain a mixture.

[0048] Example 5

[0049] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 16 g of polyether ether ketone (molecular weight of 9000 ± 500), 10.7 g of polyarylate (molecular weight of 9000 ± 500), and 5.3 g of polyimide (molecular weight of 9000 ± 500) were added and mixed to obtain a mixture.

[0050] Example 6

[0051] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 20.4 g of polyether ether ketone (molecular weight of 9000 ± 500), 8.7 g of polyarylate (molecular weight of 9000 ± 500), and 2.9 g of polyimide (molecular weight of 9000 ± 500) were added and mixed to obtain a mixture.

[0052] Example 7

[0053] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 12.3 g of polyether ether ketone (molecular weight of 9000 ± 500), 12.3 g of polyarylate (molecular weight of 9000 ± 500), and 7.4 g of polyimide (molecular weight of 9000 ± 500) were added and mixed to obtain a mixture.

[0054] Example 8

[0055] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 22 g of polyether ether ketone (molecular weight of 9000 ± 500), 10 g of glass fiber were added and mixed to obtain a mixture.

[0056] Example 9

[0057] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 22 g of polyether ether ketone (molecular weight of 9000 ± 500), 10 g of PLA-g-MAH compatibilizer were added and mixed to obtain a mixture.

[0058] Example 10

[0059] The same as Example 1, except that in Step 1, 60 g of LCP was weighed and heated to melt at 300 ± 10°C, then 12 g of polyether ether ketone (molecular weight of 9000 ± 500), 10 g of glass fiber, 10 g of PLA-g-MAH compatibilizer were added and mixed to obtain a mixture.

[0060] Comparative Example 1

[0061] 92 g of LCP was weighed and extruded by a twin-screw extruder, the temperature of the extruder was set to 280℃, and the screw rotation speed was 250 r / min, to obtain the LCP composition.

[0062] Comparative Example 2

[0063] The same as Example 1, except that the polyether ether ketone in Example 1 was replaced by polyether ether ketone with a molecular weight of 3000±300.

[0064] Comparative Example 3

[0065] The same as Example 1, except that the polyether ether ketone in Example 1 was replaced by polyether ether ketone with a molecular weight of 30000±1000.

[0066] Performance test:

[0067] The above LCP composite special for 3D printing was melt-extruded by a single-screw extruder to prepare FDM wire. The prepared FDM wire is as shown in Figure 1 ;

[0068] The prepared FDM wire was used to prepare a pentagonal pen barrel model by a high-temperature 3D printer, the nozzle printing temperature was 300±10℃, the bottom plate temperature was 100±5℃, and the line speed was 300±5 mm / s; the printed pentagonal pen barrel model is as shown in Figure 2 ; and the bottom bonding condition was observed.

[0069] The prepared pentagonal pen barrel was pressed out of the tensile sample by a mechanical spline mold, and the interlayer force was tested by a universal tensile tester, and the test results are shown in Table 1:

[0070] Table 1: Performance test results

[0071]

[0072]

[0073] Result analysis:

[0074] 1. It can be seen from Examples 1-3 that when the addition amount of each raw material in the LCP composite and the molecular weight of the oligomer are adjusted slightly, Examples 1-3 all have good bottom sticking effect and relatively excellent interlayer force, and the heat distortion temperature is also lower than that of pure LCP due to the influence of the oligomer;

[0075] Further, when the mixture of various oligomers is used in Examples 4-7, Examples 4-6 have better interlayer adhesion than Example 1 in addition to maintaining good bottom plate adhesion. As can be seen from the above table, when the oligomer is a mixture of polyarylate and polyimide, the interlayer adhesion of Example 4 is improved compared to Example 1, but the improvement is relatively small. When the oligomer is a mixture of polyether ketone ketone, polyarylate and polyimide, the interlayer adhesion of the printed product is further improved and is much higher than that of either Example 1 or Example 4. It is speculated that the main reason is that the various oligomers cooperatively improve the flowability of the LCP resin, and the oligomers all have strong polarity, so the bottom plate adhesion is further enhanced and the interlayer adhesion is also enhanced. Further observation of the interlayer adhesion of Examples 5-7 shows that when the mass ratio of polyether ketone ketone, polyarylate and polyimide is about 6:4:2, the interlayer adhesion of Example 5 is more advantageous.

[0076] 2. As can be seen from Examples 1 and 8-9, after adding glass fibers to the LCP composite, it not only has good bottom plate adhesion, but also has good interlayer adhesion. It is speculated that the reason for this phenomenon is that the strength of the resin matrix is less than the strength of the fibers. After adding the fiber reinforcing material, the total amount of fibers in the composite increases, and the fibers are the main load-bearing part of the LCP composite. When the material is subjected to external load, the resin will transfer the load to the fibers through the interface due to the good bonding surface between the fibers and the resin matrix. When the fiber content gradually increases, the load that can be borne increases and the interlayer adhesion improves.

[0077] Further observation of Example 9 shows that when the LCP composite is added with a resin compatibilizer, the interlayer adhesion of Example 9 is further improved compared to Example 1. The reason may be that the polar macromolecular main body in the resin compatibilizer is compatible with the polar polymer in the LCP, and the polar groups can react or bond with the active groups of the polar polymer in the blend, so it can play a good compatibilization role; further improve the compatibility between the resin and the LCP fibers, thereby improving the bonding force between the two and further improving the interlayer adhesion.

[0078] Observation of Example 10 shows that when the LCP composite is added with both a resin compatibilizer and a fiber reinforcing material, the interlayer adhesion of the LCP composite is further improved. The reason for this phenomenon may be that on the one hand the resin compatibilizer improves the compatibility between the resin and the fibers, so the resin can more efficiently and completely transfer the load to the fibers, and as the fiber content increases, the LCP composite as a whole can also bear more load, thereby further improving the interlayer adhesion of the product as a whole.

[0079] 4. As shown in Example 1 and Comparative Examples 1-3, when the resin material is omitted in Comparative Example 1, the interlayer force in Comparative Example 1 is significantly reduced. It is speculated that this phenomenon may be caused by the rigidity of the pure LCP molecular chain and the high glass transition temperature. During the layer-by-layer printing process, the melt rapidly cools down and enters the glassy state, resulting in a decrease in melt bonding.

[0080] Further observation of Comparative Examples 2-3 shows that when the molecular weight of the oligomer is too low, the interlayer force of the LCP composite is significantly reduced, and some edge warping occurs. It is speculated that this phenomenon may be caused by the higher melt strength of oligomers with higher molecular weight, while oligomers with too low molecular weight have shorter molecular chains and weaker adhesion, resulting in lower interlayer force and substrate adhesion.

[0081] When the molecular weight of the oligomer is too high, the interlayer force of the LCP composite is improved, but it shows obvious edge warping. It is speculated that the reason for this phenomenon may be that the oligomer with too high molecular weight has reduced fluidity, affecting the flatness of the interface, and cannot adhere to the substrate well, or reducing the interlayer force.

[0082] Furthermore, the sample printed using the high temperature resistant particle 3D printing consumables of Example 1 is as follows Figure 3 shown.

[0083] The embodiments presented herein are merely embodiments selected from a combination of all possible embodiments. The appended claims should not be limited by the embodiments describing the present invention. Some numerical ranges used in the claims include subranges therein, and variations in these ranges should also be covered by the appended claims.

Claims

1. A LCP compound for 3D printing, characterized in that: The LCP compound dedicated to 3D printing is prepared by mixing and extruding an oligomer with a molecular weight of 5,000 to 20,000 and molten LCP; The mass ratio of the oligomer to the LCP is 5-40:50-95.

2. The LCP compound for 3D printing according to claim 1, characterized in that The oligomer is selected from at least one of polyetheretherketone, polyetherketoneketone, polyphenylene sulfide, polyimide, polysulfone, and polyarylate.

3. The LCP compound for 3D printing according to claim 2, characterized in that: The oligomer is a mixture of polyetheretherketone, polyarylate and polyimide, and the mass ratio of polyetheretherketone, polyarylate and polyimide is 5-7:3-5:1-3.

4. The LCP compound for 3D printing according to claim 1, characterized in that A resin compatibilizer is also added, and the mass ratio of the oligomer, the resin compatibilizer and the LCP is 5-40:0.1-10:50-95; The resin compatibilizer includes a polymer main chain and an active group connected to the polymer main chain; The polymer main chain is selected from any one of polyamide, polyimide, and polylactic acid; The active group is selected from any one of hydroxyl, amino, epoxy and maleic anhydride.

5. The LCP compound for 3D printing according to claim 1, characterized in that: The LCP composite specifically for 3D printing is further added with a fiber reinforcement material, wherein the fiber reinforcement material is selected from at least one of carbon fiber, glass fiber, metal fiber, and polymer fiber.

6. The LCP compound for 3D printing according to claim 1, characterized in that: The mass ratio of the fiber reinforcement material to the LCP is 10-30:70-90.

7. A method for preparing the LCP composite for 3D printing according to any one of claims 1 to 6, characterized in that: The LCP is melted and mixed with the oligomer, and then extruded using an extruder to obtain an LCP compound specifically for 3D printing.

8. The method for preparing the LCP compound for 3D printing according to claim 7, characterized in that: The specific steps include: Step 1: Melting the LCP and mixing it with the resin compatibilizer and oligomer to obtain a mixture; Step 2: The mixture is extruded into granules through a twin-screw extruder to obtain an LCP compound for 3D printing; In step 2, the temperature of the twin-screw extruder is 280-320° C., and the screw speed is 250-300 r / min.

9. The method for preparing the LCP compound for 3D printing according to claim 7, characterized in that: The step 1 specifically comprises: melting the LCP and mixing it with a resin compatibilizer, an oligomer and a fiber reinforcement to obtain a mixture.

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