3D printing composite material and preparation method thereof

Abstract

The invention discloses a 3D printing composite material and a preparation method thereof. The 3D printing composite material is prepared from 79-90 parts by weight of ultra-high molecular weight polyethylene, 5-15 parts by weight of modified illite, 5-15 parts by weight of modified microcrystalline muscovite, 0.5-1.5 parts by weight of an intercalation aid, 0.5-1.5 parts by weight of a processing aid and 0.5 parts by weight of an antioxidant. The 3D printing composite material has relatively high rigidity, heat resistance and surface lubricity, and is relatively low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a 3D printing composite material and a preparation method thereof. Background Art

[0002] 3D printing (3DP), which is also known as additive manufacturing, is a kind of rapid prototyping technology. It is a technology that constructs objects by layer-by-layer printing based on digital model files, using powdery metals or plastics and other bondable materials. Although high-end industrial printing can achieve printing of plastics, certain metals or ceramics, the materials that cannot be printed are relatively expensive and scarce. In addition, the printers have not yet reached a mature level and cannot support a variety of materials that are encountered in daily life. At present, certain progress has been made in 3D printing materials, but unless these progress reach maturity and effectiveness, the materials will still be a major obstacle to 3D printing. Summary of the Invention

[0003] In view of this, it is necessary for the present invention to provide a 3D printing composite material, which has high rigidity, heat resistance and surface lubricity, and low cost.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect of the present invention, there is provided a 3D printing composite material, which is prepared from 79 - 90 parts by weight of ultra-high molecular weight polyethylene, 5 - 15 parts by weight of modified illite, 5 - 15 parts by weight of modified microcrystalline muscovite, 0.5 - 1.5 parts by weight of an intercalation aid, 0.5 - 1.5 parts by weight of a processing aid, and 0.5 parts by weight of an antioxidant.

[0006] Illite is a common clay mineral, often formed by the weathering of muscovite and potassium feldspar, and is produced in argillaceous rocks or formed by the alteration of other minerals. It is often an intermediate transitional mineral for the formation of other clay minerals. And microcrystalline muscovite powder is a new type of inorganic functional filler with high muscovite content, good whiteness, large activity, and easy dyeing and modification.

[0007] In the present invention, these two inorganic fillers with different structures are surface-modified and then used in combination, which improves the compatibility between the filler and the polymer substrate. Due to the use of inorganic fillers with different structures in compounding, the mechanical properties of the composite material in different directions are kept consistent, ensuring the overall strength of the 3D printing composite material. The obtained composite material has high rigidity and surface lubricity, and low cost.

[0008] Further, the melt index of the ultra-high molecular weight polyethylene (UHMWPE) is ≤ 0.2 g / 10 min under the test conditions of 190 °C and 21.6 kg.

[0009] In a further embodiment, the modified illite is obtained by soaking illite powder in hydrazine hydrate at 8 - 15 times the mass, followed by ultrasonic treatment and then mechanical grinding for 30 - 60 minutes. In this application, hydrazine hydrate is used as a good intercalating agent to assist mechanical grinding in well exfoliating illite, thus achieving a better dispersion effect.

[0010] In a further embodiment, the modified microcrystalline muscovite is obtained by modification with aluminate coupling agent. The specific method is as follows: 100 parts of microcrystalline muscovite are stirred evenly in 500 - 1500 parts of ethyl acetate, then 0.5 - 2.5 parts of aluminate coupling agent are added, and the mixture is heated to 80 - 90 °C and refluxed with stirring for 1 - 2 hours, followed by filtration and drying. For various inorganic powders activated and modified by aluminate coupling agent, due to chemical or physicochemical reactions occurring on their surfaces to form an organic molecular layer, their hydrophilicity changes to organophilicity. Practice has proved that when inorganic powders surface - modified by aluminate coupling agent are used in composite products, the inorganic - affinity end and the organic - affinity end of the coupling agent can respectively react chemically or form an entangled structure with the surface of the inorganic filler and the organic resin, enhancing the interfacial compatibility between the inorganic powder and the organic resin. Therefore, in this application, aluminate coupling agent is used to modify microcrystalline muscovite, which can not only improve the processing performance of plastic products filled with microcrystalline muscovite, but also significantly improve the physical and mechanical properties of the products, reducing the water absorption rate and oil absorption amount of the products and making the filler dispersion more uniform.

[0011] In a further embodiment, the intercalation aid is one or a mixture of two or more of cationic surfactants and pyridinium salt surfactants.

[0012] In a further embodiment, the cationic surfactant is alkyl ammonium salt or quaternary ammonium salt.

[0013] In a further embodiment, the pyridinium salt surfactant is cetylpyridinium bromide.

[0014] In a further embodiment, the processing aid is a lubricant.

[0015] In a further embodiment, the lubricant is selected from one or a mixture of two or more of EBS, erucamide, oleamide, zinc stearate, magnesium stearate, and calcium stearate.

[0016] In a further embodiment, the antioxidant is selected from at least one of pentaerythritol tetra[β-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate] (antioxidant 1010), octadecyl 3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate (antioxidant 1076), tris(2,4 - di - tert - butylphenyl) phosphite (antioxidant 168), and distearyl thiodipropionate (antioxidant DSTDP).

[0017] The second aspect of the present invention provides a method for preparing a 3D printing composite material as described in the first aspect of the present invention, comprising the following steps:

[0018] Mix 70-90 parts by weight of ultra-high molecular weight polyethylene, 5-15 parts of modified illite, 5-15 parts of modified microcrystalline muscovite, 0.5-1.5 parts of intercalation aid, 0.5-1.5 parts of processing aid, and 0.5 parts of antioxidant thoroughly to obtain a uniform mixture;

[0019] Add the mixture into a twin-screw wire extruder and process to obtain a 3D printing composite material.

[0020] In a further embodiment, the temperatures of each zone of the twin-screw wire extruder are successively: 185-195°C, 190-200°C, 190-200°C, 190-200°C, 190-200°C, 190-200°C, 200-210°C, 200-210°C, 210-220°C, 220-230°C.

[0021] Advantages of the present invention:

[0022] The 3D printing composite material provided by the present invention has high rigidity. By using two inorganic fillers with different structures and combining the surface modification process of the fillers, the compatibility between the fillers and the polymer matrix is improved, and the mechanical properties of the material in different directions are enhanced. The prepared composite material has high rigidity and surface lubricity.

[0023] Specifically, the present invention disperses the composite filler in the polymer matrix in a melt intercalation manner, greatly enhancing the strength and heat resistance of the composite material. The properties of the obtained composite material are comparable to those of 3D printing materials, and the cost is significantly lower than that of existing 3D printing materials.

[0024] The present invention adopts the mixture of two different types of inorganic fillers with lamellar structures. The filling mixture with different aspect ratios can make up for the structural defects and isotropy brought by a single filler, making the mechanical properties of the composite material consistent in different directions and ensuring the overall strength of the 3D printing products prepared using this composite material. Specific embodiments

[0025] The embodiments of the present invention are described in detail below. The following described embodiments are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein are identical with the meanings generally understood by those skilled in the art belonging to the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. In addition, unless otherwise specified, the method without specific recording conditions or steps is a conventional method, and the reagents and materials adopted can be obtained from commercial sources. The "parts", "number of parts" etc. all refer to parts by weight.

[0027] The raw material information used in the following examples and comparative examples is as follows:

[0028] Ultra-high molecular weight polyethylene, grade 4152, purchased from Celanese;

[0029] Illite powder was purchased from Lingshou County Antai Mining Co., Ltd.;

[0030] Microcrystalline muscovite, 3000 mesh, purchased from Lianyungang Rongbai New Materials Co., Ltd.;

[0031] Aluminate coupling agent, DL-411-A, was purchased from Nanjing Pinning Coupling Agent Co., Ltd.;

[0032] The intercalation aid is a mixture of hexadecyltrimethylammonium bromide (purchased from Shandong Guohua Chemical) and hexadecylpyridinium bromide (purchased from Aladdin) in a mass ratio of 3:2;

[0033] The processing aid is a mixture of erucamide (purchased from Shanghai Huayi Additive Co., Ltd.) and zinc stearate (purchased from Qingdao Sino New Materials Co., Ltd.) in a mass ratio of 1:4;

[0034] The antioxidant was a mixture of 1010, 168 and DSTDP in a mass ratio of 2:2:1, all of which were purchased from BASF.

[0035] The modified illite is obtained by soaking illite powder in hydrazine hydrate with a mass of 10 times the amount in an ultrasonic manner and then mechanically grinding the illite powder for 30-60 minutes.

[0036] The modified microcrystalline mica is obtained by modifying microcrystalline muscovite with an aluminate coupling agent DL-411-A. The specific steps are as follows: 100 microcrystalline muscovite is uniformly stirred in 1000 parts of ethyl acetate, 1.5 parts of aluminate coupling agent DL-411-A is added, and the mixture is heated to 85°C, refluxed and stirred for 1.5 hours, filtered and dried to obtain the modified microcrystalline mica.

[0037] Example 1

[0038] According to the weight ratio, 70 parts of ultra-high molecular weight polyethylene, 15 parts of modified illite, 15 parts of modified microcrystalline muscovite, 1.5 parts of intercalation aid, 1.5 parts of processing aid and 0.5 parts of antioxidant were added into a high-speed mixer and mixed for 15 minutes to obtain a uniform mixture;

[0039] Then the mixture is added into a twin-screw wire extruder, and after extrusion, cooling and winding, a 3D printing composite material wire is obtained; among them, the extrusion temperatures of each extrusion zone in the twin-screw wire extruder are 195°C, 200°C, 200°C, 200°C, 200°C, 200°C, 210°C, 210°C, 220°C, 230°C respectively.

[0040] Example 2

[0041] According to the weight ratio, 80 parts of ultra-high molecular weight polyethylene, 10 parts of modified illite, 10 parts of modified microcrystalline muscovite, 1.0 part of intercalation aid, 1.0 part of processing aid and 0.5 part of antioxidant are added into a high-speed mixer and mixed for 10 min to obtain a uniform mixture;

[0042] Then the mixture is added into a twin-screw wire extruder, and after extrusion, cooling and winding, a 3D printing composite material wire is obtained; among them, the extrusion temperatures of each extrusion zone in the twin-screw wire extruder are 190°C, 195°C, 195°C, 195°C, 195°C, 195°C, 205°C, 205°C, 215°C, 225°C respectively.

[0043] Example 3

[0044] According to the weight ratio, 90 parts of ultra-high molecular weight polyethylene, 5 parts of modified illite, 5 parts of modified microcrystalline muscovite, 0.5 part of intercalation aid, 0.5 part of processing aid and 0.5 part of antioxidant are added into a high-speed mixer and mixed for 5 min to obtain a uniform mixture;

[0045] Then the mixture is added into a twin-screw wire extruder, and after extrusion, cooling and winding, a 3D printing composite material wire is obtained; among them, the extrusion temperatures of each extrusion zone in the twin-screw wire extruder are 185°C, 190°C, 190°C, 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, 220°C respectively.

[0046] Performance Test 1

[0047] The 3D printing composite material wires prepared in Examples 1-3 are made into test specimens by 3D printing for relevant performance tests, among which:

[0048] Tensile strength test: 1A type molded specimen, tensile speed 50 mm / min;

[0049] The 90° tensile test is obtained by cutting an injection molded plate in the direction perpendicular to the flow direction;

[0050] Flexural modulus: sample size 100 mm × 10 mm × 4 mm, test speed: 2 mm / min;

[0051] Izod notched impact strength: A-type molded notch, sample size 100 mm × 10 mm × 4 mm.

[0052] The test results are shown in Table 1.

[0053] Table 1 Test results of the properties of 3D printing composite material wires in Examples 1-3

[0054] Test item / Unit Test standard Example 1 Example 2 Example 3 Tensile strength / Mpa ISO 527 33.2 28.7 26.4 Tensile strength (90°) / Mpa ISO 527 32.6 28.2 25.8 Flexural modulus / Mpa ISO 178 1675 1338 1097 Izod notched impact strength / KJ / ㎡ ISO 180 108.1 110.5 113.4 <![CDATA[Density / g / cm 3 > ISO 1183 1.152 1.081 1.017

[0055] Comparative Example 1

[0056] This comparative example adopts the same implementation method as Example 3, with the only difference being that "5 parts of modified illite and 5 parts of modified microcrystalline muscovite" are replaced by "10 parts of modified illite". The specific steps are as follows:

[0057] According to the weight ratio, 90 parts of ultra-high molecular weight polyethylene, 10 parts of modified illite, 0.5 part of intercalation aid, 0.5 part of processing aid, and 0.5 part of antioxidant are added to a high-speed mixer and mixed for 5 min to obtain a uniform mixture;

[0058] Then the mixture is added to a twin-screw wire extruder, and 3D printing composite material wire is obtained through extrusion, cooling, and winding; among them, the extrusion temperatures of each extrusion zone in the twin-screw wire extruder are 185 °C, 190 °C, 190 °C, 190 °C, 190 °C, 190 °C, 200 °C, 200 °C, 210 °C, and 220 °C respectively.

[0059] Comparative Example 2

[0060] This comparative example adopts the same implementation method as Example 3, with the only difference being that "5 parts of modified illite and 5 parts of modified microcrystalline muscovite" are replaced by "10 parts of modified microcrystalline muscovite". The specific steps are as follows:

[0061] According to the weight ratio, 90 parts of ultra-high molecular weight polyethylene, 10 parts of modified microcrystalline muscovite, 0.5 part of intercalation aid, 0.5 part of processing aid, and 0.5 part of antioxidant are added to a high-speed mixer and mixed for 5 min to obtain a uniform mixture;

[0062] Then the mixture is added to a twin-screw wire extruder, and 3D printing composite material wire is obtained through extrusion, cooling, and winding; among them, the extrusion temperatures of each extrusion zone in the twin-screw wire extruder are 185 °C, 190 °C, 190 °C, 190 °C, 190 °C, 190 °C, 200 °C, 200 °C, 210 °C, and 220 °C respectively.

[0063] Comparative Example 3

[0064] This comparative example uses the same implementation method as Example 3, with the only difference being that no intercalation aid is added. The specific steps are as follows:

[0065] According to the weight ratio, 90 parts of ultra-high molecular weight polyethylene, 5 parts of modified illite, 5 parts of modified microcrystalline muscovite, 0.5 part of processing aid, and 0.5 part of antioxidant were added to a high-speed mixer and mixed for 5 minutes to obtain a uniform mixture;

[0066] Then the mixture was added to a twin-screw wire extruder, and a 3D printing composite material wire was obtained through extrusion, cooling, and winding; among them, the extrusion temperatures in each extrusion zone of the twin-screw wire extruder were 185°C, 190°C, 190°C, 190°C, 190°C, 190°C, 200°C, 200°C, 210°C, and 220°C respectively.

[0067] Performance Test 2

[0068] The 3D printing composite material wires prepared in Comparative Examples 1-3 were tested for performance using the same method as in Performance Test 1, and the results are shown in Table 2.

[0069] Table 2 Performance test results of the 3D printing composite material wires in Example 3 and Comparative Examples 1-3

[0070] Test item / Unit Test standard Example 3 Comparative example 1 Comparative example 2 Comparative example 3 Tensile strength / Mpa ISO 527 26.4 26.4 28.4 17.6 Tensile strength (90°) / Mpa ISO 527 25.8 20.6 19.2 18.1 Flexural modulus / Mpa ISO 178 1097 1027 1015 974 Izod notched impact strength / KJ / ㎡ ISO 180 113.4 97.4 109.8 62.5 Density / g / cm3 ISO 1183 1.017 1.018 1.020 1.018

[0071] It can be seen from the data in Table 1 and Table 2 that the composite filling method adopted in the present invention can effectively improve the rigidity of the material, and the strength of the material's mechanical properties is consistent in all directions. The addition of the intercalating agent makes the dispersion of the filler more uniform and can prevent the occurrence of stress concentration phenomena inside the material.

[0072] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0073] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A 3D printing composite material, characterized in that, It is prepared by weight parts from 79 - 90 parts of ultra-high molecular weight polyethylene, 5 - 15 parts of modified illite, 5 - 15 parts of modified microcrystalline muscovite, 0.5 - 1.5 parts of intercalation aid, 0.5 - 1.5 parts of processing aid and 0.5 part of antioxidant.

2. The 3D printing composite material according to claim 1, wherein The melt index of the ultra-high molecular weight polyethylene under the test conditions of 190 °C and 21.6 kg is ≤ 0.2 g / 10 min.

3. The 3D printing composite material according to claim 1, wherein, The modified illite is obtained by soaking the illite powder in hydrazine hydrate with 8 - 15 times the mass, ultrasonic treatment, and then mechanical grinding for 30 - 60 min. Preferably, the modified illite is obtained by soaking the illite powder in hydrazine hydrate with 10 times the mass, ultrasonic treatment, and then mechanical grinding for 30 - 60 min.

4. The 3D printing composite material according to claim 1, wherein, The modified microcrystalline muscovite is obtained after being modified by aluminate coupling agent. Preferably, the specific modification method of the modified microcrystalline muscovite is: uniformly stirring 100 parts of microcrystalline muscovite in 500 - 1500 parts of ethyl acetate, adding 0.5 - 2.5 parts of aluminate coupling agent, heating to 80 - 90 °C and refluxing and stirring for 1 - 2 h, then filtering and drying to obtain it.

5. The 3D printing composite material according to claim 1, wherein The intercalation aid is one or a mixture of two or more of cationic surfactants and pyridinium salt surfactants. Preferably, the cationic surfactant is alkyl ammonium salt or quaternary ammonium salt. Preferably, the pyridinium salt surfactant is cetylpyridinium bromide.

6. The 3D printing composite material according to claim 1, wherein, The processing aid is a lubricant.

7. The 3D printing composite material according to claim 6, wherein The lubricant is selected from one or a mixture of two or more of EBS, erucamide, oleamide, zinc stearate, magnesium stearate, and calcium stearate.

8. The 3D printing composite material according to claim 1, wherein The antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, antioxidant 168, and antioxidant DSTDP.

9. A method for preparing a 3D printing composite material according to any one of claims 1-8, characterized in that, It includes the following steps: Mix 70 - 90 parts of ultra-high molecular weight polyethylene, 5 - 15 parts of modified illite, 5 - 15 parts of modified microcrystalline muscovite, 0.5 - 1.5 parts of intercalation aid, 0.5 - 1.5 parts of processing aid and 0.5 part of antioxidant in proportion by weight to obtain a uniform mixture. Add the mixture into a twin-screw wire extruder to process and obtain a 3D printing composite material.

10. The preparation method according to claim 9, characterized in that, The temperatures of each zone of the twin-screw wire extruder are in sequence: 185 - 195 °C, 190 - 200 °C, 190 - 200 °C, 190 - 200 °C, 190 - 200 °C, 190 - 200 °C, 200 - 210 °C, 200 - 210 °C, 210 - 220 °C, 220 - 230 °C.