Metallic polymer composite for 3D printing and method for preparing the same

Abstract

The application discloses a kind of metal polymer composite for 3D printing and preparation method thereof, the composite is prepared by compounding semi-solid metal alloy modified by coupling agent with polymer material.The preparation method is: modified semi-solid metal alloy, polymer material, functional additive are mixed, and are processed into shape to be prepared;Or modified semi-solid metal alloy, polymer material, functional additive are mixed, material for 3D printing, and are solidified into shape again.The composite of the application is used at temperature of 20-230 DEG C, viscosity is 1-10 5 Pa·S, resistivity is 10 ‑6 ~10 6 Ω·cm;Preparation method is simple, raw material cost is low, non-toxic, post-processing is simple, so that material is applied to 3D printing when extruding evenly, speed is controllable, warpage is low, and the prepared conductive polymer material is easy to store, small in density, stable in conductive effect, compared with traditional conductive printing material, and conductive performance is obviously improved.

Description

Technical Field

[0001] This invention relates to a 3D printing material and its preparation method, and more particularly to a metal polymer composite material for 3D printing and its preparation method. Background Technology

[0002] 3D printing technology has been widely applied in fields such as jewelry, footwear, industrial design, architecture, medicine, and aerospace. 3D printing utilizes powdered, bondable materials such as metals or plastics to construct objects layer by layer. Traditional printing materials are categorized into three types: non-metallic materials, metallic materials, and biomaterials. Among these, non-metallic polymers, such as polylactic acid, nylon, acrylonitrile-butadiene-styrene plastics, and rubber, and metallic materials, such as iron-based alloys, titanium and titanium-based alloys, nickel-based alloys, cobalt-chromium alloys, aluminum alloys, copper alloys, and precious metals, are the most mature printing consumables in the field of 3D printing.

[0003] However, metal materials suffer from drawbacks such as high density, high cost, high melting temperature, and complex printing processes, which limit the development of 3D printing technology for metal materials. In contrast, polymer materials are diverse and possess excellent properties, meeting the performance requirements of various technologies and equipment. They exhibit many superior characteristics, such as heat resistance, wear resistance, high plasticity, good processability, and strong weather resistance. Compared to metal materials, polymer materials have superior corrosion resistance. Under specific conditions, their rapid curing, thermoplasticity at relatively low temperatures, good thermal flowability, and rapid cooling bonding are also significant advantages. However, pure polymer materials lack electrical conductivity, failing to meet the conductive sensing requirements of fields such as medical, electronic, and mechanical applications.

[0004] Considering the above issues, research on conductive metal polymer composite materials that can be used for 3D printing is of great significance. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a metal-polymer composite material for 3D printing that combines high conductivity, low processing temperature, and suitable flowability.

[0006] A second objective of this invention is to provide a method for preparing the aforementioned metal-polymer composite material for 3D printing.

[0007] Technical solution: The metal-polymer composite material that can be used for 3D printing described in this invention is prepared by combining a semi-solid metal alloy modified with a coupling agent with a polymer material.

[0008] The composite material also includes functional additives, and the volume fractions of each component are as follows: modified semi-solid metal alloy 10%–65%; polymer material 25%–89%; and functional additives 0%–10%.

[0009] The semi-solid metal alloy is made of two or more elements selected from gold, silver, copper, zinc, mercury, platinum, cadmium, aluminum, iron, nickel, gallium, indium, tin, zinc, bismuth, lead, chromium, cesium, titanium, vanadium, lanthanides, actinides, scandium, iridium, tungsten, and yttrium.

[0010] The coupling agent is prepared by modifying a semi-solid metal alloy using one or more of the following: silane coupling agent, titanate coupling agent, aluminate coupling agent, and bimetallic coupling agent. The coupling agent molecule simultaneously possesses reactive groups capable of binding with inorganic materials and reactive groups capable of binding with organic materials. In this invention, it is used as a surface modifier to improve the dispersibility and adhesion between the semi-solid metal alloy and the polymer material, ensuring that the warpage of the 3D printed product meets the requirements.

[0011] The specific preparation process of the modified semi-solid metal alloy is as follows: a coupling agent, alcohol, and water are mixed and hydrolyzed to obtain a hydrolysate. The semi-solid metal alloy is then placed in the hydrolysate, stirred, washed, and dried to obtain the modified semi-solid metal alloy. Acetic acid is added to the hydrolysate to help adjust the pH value of the hydrolysate and provide a more favorable environment for the surface modification reaction. The pH of the hydrolysis is 4 to 6, preferably 5.

[0012] Wherein, the alcohol is one of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, tert-butanol, and ethylene glycol; the volume ratio of the coupling agent: alcohol: water is 1-10:3-50:40-96; the semi-solid metal alloy accounts for a mass fraction of greater than 0 and less than 200% of the coupling agent hydrolysate; the hydrolysis time is 1-48 hours, preferably 4 hours; the hydrolysis method is one or more of ultrasonic, magnetic stirring, and mechanical stirring; the drying time is 0.1-4 hours, preferably 1 hour.

[0013] The silane coupling agent is one or more of aminosilane, epoxysilane, vinylsilane, sulfur-containing silane, acylsilane, octylsilane, alkylsilane, piperazine silane, and other silanes.

[0014] The titanate coupling agent is one or more of the following: isopropyl tristearate titanate, isopropyl dioleoyloxy (dioctyl phosphate oxy) titanate, isopropyl trioleoyloxy titanate, isopropyl tris(dioctyl pyrophosphate oxy) titanate, bis(dioctyl pyrophosphate ester) ethylene titanate, diisopropyloxy diacetylacetone titanate, and phosphate bistitanate coupling agent.

[0015] The polymeric materials mentioned include polyimide, polyethylene terephthalate, polylactic acid, polyurethane, polyethylene, polytetrafluoroethylene, nylon, polyphenylene ether ketone, polyphenylene sulfide, polychlorotrifluoroethylene, ethylene-propylene copolymer, polyethylene terephthalate, polybutylene terephthalate, ethylene-tetrafluoroethylene copolymer, polyvinyl alcohol, polypropylene, polystyrene, polyvinyl chloride, styrene-isoprene copolymer, hydrogenated styrene-isoprene copolymer, phenolic resin, photosensitive resin, urea-formaldehyde resin, melamine resin, epoxy resin, silicone resin, unsaturated polyester resin, alkyd resin, polybutadiene resin, vinyl resin, furan resin, organosilicon resin, cellulose resin, aldehyde-ketone resin, fluorocarbon resin, and polymethyl methacrylate. The following are included in the following categories: polyetheretherketone resin, polyoxymethylene, polycarbonate, polybutene, polyvinylidene fluoride, polyacrylonitrile, polyvinylidene chloride, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, chlorinated polypropylene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer, styrene-butadiene rubber, chloroprene rubber, cis-butadiene rubber, butyl rubber, isoprene rubber, ethylene-propylene rubber, EPDM rubber, natural rubber, nitrile rubber, chlorinated polyethylene, butyl pyridine rubber, chloroether rubber, chlorosulfonated polyethylene, polysulfide rubber, polyacrylate rubber, polyurethane rubber, fluororubber, polydimethylsiloxane, styrene-ethylene-butene-styrene block copolymer, and Ecoflex rubber.

[0016] The functional additives are one or more of the following plastic and rubber additives: toughening agents, plasticizers, antistatic agents, defoamers, antioxidants, heat stabilizers, thixotropic agents, bactericides and fungicides, colorants, flame retardants, lubricants, etc.

[0017] The toughening agent is an unsaturated polyester resin, such as 302 polyester, 304 polyester, 305 polyester, etc.; rubbers, such as polysulfide rubber, nitrile rubber, hydroxyl-terminated liquid nitrile rubber, thiol-terminated nitrile rubber, chloroprene rubber, polyurethane rubber, etc.; polyamide resin, one of which is a low-molecular-weight polymer of dimer or trimerized vegetable oil, unsaturated fatty acids or aromatic acids, alkyl polyamines; another is modified nylon such as hydroxymethyl nylon; acetal resin, such as polyvinyl alcohol formaldehyde, polyvinyl alcohol acetal, polyvinyl alcohol hexanal, polyvinyl alcohol butyral, polyvinyl alcohol furfural, etc.; polysulfone resin; polyurethane resin, etc., or one or more of these combined.

[0018] The plasticizer is at least one of the following plastic plasticizers: dioctyl phthalate, dibutyl phthalate (DBP), dioctyl sebacate (DOS), dioctyl adipate (DOA), tricresyl phosphate (TCP), chlorinated paraffin, epoxidized soybean oil (ESO), propylene glycol sebacate (PPS), propylene glycol adipate (PPA), diethylene glycol dibenzoate (DEDB), dipropylene glycol dibenzoate (DPDB), alkyl sulfonate phenyl ester (T-50); or at least one of the following rubber plasticizers: processing oil, heavy oil, coal tar, paraffin wax, petrolatum, asphalt, petroleum resin, coal tar, coumarone resin, coal tar pitch, rosin, pine tar, terpene resin, ointment, phthalate, phosphate ester, aliphatic diester, nitrile rubber, liquid polybutadiene, or liquid polyisobutylene.

[0019] The antistatic agent is one or more of the following: trihydroxyethylmethyl quaternary ammonium methyl sulfate, octadecyl dimethyl quaternary ammonium nitrate, stearyl trimethyl quaternary ammonium hydrochloride, sodium p-nonylphenoxypropyl sulfonate, dodecyl dimethyl quaternary acetone, and alkyl dicarboxymethyl ammonium acetone.

[0020] Furthermore, the defoamer is one or more of the following: high carbon alcohol fatty acid ester complex, polyoxyethylene polyoxypropylene pentaerythritol ether, emulsified silicone oil, polyoxyethylene polyoxypropylene amine ether, polydimethylsiloxane, polyoxypropylene glycerol ether, and polyoxypropylene polyoxyethylene glycerol ether.

[0021] The antioxidant is one or more of the following: 2,6-di-tert-butyl-p-cresol (BHT or antioxidant 264), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (antioxidant CA), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (antioxidant 330), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (MEB), tris(nonylphenyl) phosphite (TNP), and pentaerythritol dioctadecanyl phosphite (DPD).

[0022] The heat stabilizer is one or more of the following: antimony thiols, epoxides, phosphites, semi-solid alcohols, β-diketones, solid Ga / Zn composite stabilizers, tribasic lead sulfate, dibasic lead phosphite, dibasic lead stearate, dibasic lead phthalate, tribasic lead maleate, stearic acid, lauric acid, palmitic acid, oleic acid, metal salts, thiols, fatty acid salts, maleates, and lanthanide rare earth metals.

[0023] The thixotropic agent is one or more of the following: LBCB-1 thixotropic lubricant, fumed silica, precipitated silica, organobentonite, asbestos, kaolin, attapulgite, emulsion vinyl chloride compound, metal soap, hydrogenated castor oil, polyvinyl alcohol, polyacrylate, etc.

[0024] The bactericide and antifungal agent is one or more of pentachlorophenol, sodium salt, 2-(4-thiazolyl)benzene, imidazole, thiocarbamate, etc.

[0025] The colorant is at least one of carbon black, gold powder, silver powder, titanium dioxide, zinc barium white, chrome yellow, cadmium red, azo compounds, phthalocyanine compounds, dioxazine compounds, or fluorescent compounds.

[0026] The flame retardant is one or more of the following: red phosphorus, phosphate and ammonium polyphosphate, aluminum hydroxide and magnesium hydroxide flame retardants, antimony trioxide, colloidal antimony pentoxide and sodium antimony, zinc borate, and dihydroxyl metal oxides (LDHs).

[0027] The lubricant is one or more of the following: tristearate, higher fatty alcohols, semi-solid alcohols, polyethylene glycol, stearic acid, stearic acid soap, n-butyl stearate, glyceryl monostearate, stearamide, ethylene bisoleamide, ethylene bisstearamide, paraffin wax, polypropylene glycol, and oleamide.

[0028] The above-mentioned method for preparing metal-polymer composite materials that can be used for 3D printing involves mixing a modified semi-solid metal alloy and polymer material as the main material with functional additives as auxiliaries, and then processing and molding the mixture to obtain the final product.

[0029] Alternatively, modified semi-solid metal alloys and polymer materials, which serve as the main materials, can be mixed with functional additives as auxiliaries for use in 3D printing, and then solidified into a mold.

[0030] The mixing method is one or more of the following: chemical cross-linking, mechanical stirring, electromagnetic stirring, grinding, ultrasonic dispersion, and heating melting.

[0031] The processing and molding methods include one or more of the following: extrusion, blow molding, pressing, injection molding, calendering, blow molding, stretching film, static casting, embedding casting, centrifugal casting, casting casting, slush molding, rotational molding, cold pressing sintering, coating, spinning, and foaming.

[0032] The curing and molding method is one or more of the following: room temperature natural curing, water bath heating curing, ultraviolet light curing, infrared light curing, and hot air circulation curing.

[0033] Working Principle: This invention introduces two-phase and multi-phase semi-solid metal alloys as conductive fillers into polymer materials. Through low-melting-point alloy-polymer composites, preparation and printing are achieved at room temperature. The semi-solid metal alloys form solid, liquid, and solid-liquid two-phase metals within a relatively low temperature range, capable of phase transitions. These phase transitions can be precisely controlled by adjusting temperature or atomic ratios according to the lever rules in the phase diagram. Simultaneously, the viscosity of the semi-solid metal is significantly affected by temperature. By changing the temperature and composition, its viscosity can be adapted to many different types of polymer materials. The resulting composite can also be controlled by varying the amount of metal filler and adjusting the solid-liquid ratio of the metal, thereby controlling the material preparation temperature and the viscosity of the composite material. This allows for flexible printing under various environments and conditions, and convenient storage. The solid-liquid ratio of the metal in the composite has a crucial impact on the composite viscosity and conductive network pathways. During alloy modification, this invention significantly improves the compatibility with organic materials, helping to solve the problem of difficult mixing of metals and polymers and improving mixing efficiency. Simultaneously, the addition of different additives to the polymer material improves the polymer's processing performance, optimizes processing conditions, and enhances the overall quality of the printed product.

[0034] This invention involves adding one or more conductive fillers to a polymer material and obtaining a novel 3D printing composite material that meets conductivity requirements through a specific processing method. The metal-polymer composite material of this invention simultaneously possesses high conductivity, low processing temperature, and suitable flowability, enabling the material to achieve 3D printability at lower temperatures and demonstrating promising practical applications.

[0035] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) By modifying semi-solid metal alloys, the problem of incompatibility between polymer and metal phases is solved. Then, by applying the viscosity matching principle, alloys and polymer materials with similar viscosity are found to prepare uniform composite conductive fiber materials, and the conductivity can be achieved from 10 -6 Up to 10 6 S / cm variation. (2) The composite material is easy to store, has low density, stable conductivity and thermoplasticity, and can be repeatedly extruded. Compared with traditional conductive printing materials, its conductivity is significantly improved. (3) The preparation method is simple and easy to implement, low cost, non-toxic and easy to process. (4) The material can be used in traditional extrusion or injection molding to make conductive rolls, wires and sheets, and can also be used in emerging research fields such as 3D printing, smart wearables, and circuit design. Attached Figure Description

[0036] Figure 1 This is a printed image of the finished product from Embodiment 2 of the present invention;

[0037] Figure 2 The image shows the 3D printing material and the finished 3D printed product prepared in Example 13 of this invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] Example 1

[0040] A method for preparing a metal-polymer composite material that can be used for 3D printing includes the following steps:

[0041] (1) Metals Ga and Sn are weighed in a certain mass according to an atomic ratio of 4:6, and heated to 235℃ to melt and mix them into Ga. 0.4 Sn 0.6 The alloy was continuously stirred during the cooling process to room temperature to obtain metal powder.

[0042] (2) For Ga 0.4 Sn 0.6 The alloy was modified at room temperature using KH-310 as the modifier. KH-310, methanol, and water were mixed at a volume ratio of 5:20:75 and then magnetically stirred at 600 rpm for 4 hours at room temperature. Ga was then added. 0.4 Sn 0.6 The alloy was stirred for another 30 minutes, and the mass ratio of the metal alloy to the hydrolysate was 95%. Finally, the supernatant was poured off and placed in an oven at 100°C for 1 hour to obtain the modified Ga0.4Sn0.6 alloy.

[0043] (3) Polydimethylsiloxane (PDMS) and its curing agent were selected as the polymer material, and BYK-410 additive was added. The mixture was mechanically stirred at high speed for 1500 rpm for 12 min to obtain the mixture substrate.

[0044] (4) The modified Ga0.4Sn0.6 alloy and the mixture substrate are ground and fully dispersed, and then introduced into a 3D printing machine for fused deposition modeling rapid prototyping 3D printing at room temperature. After printing, the molten metal is heated and cured.

[0045] Example 2

[0046] The basic steps are the same as in Example 1, and the specific parameters are shown in Table 1.

[0047] like Figure 1 As shown, the composite material prepared in this embodiment produces a pattern with high conductivity and clear image by printing first and then heating to cure.

[0048] Example 3

[0049] The basic steps are the same as in Example 1, and the specific parameters are shown in Table 1.

[0050] Example 4

[0051] The basic steps are the same as in Example 1, and the specific parameters are shown in Table 1.

[0052] Table 1

[0053]

[0054] For Examples 1-4, the basic steps are the same. At 30°C, the solid fraction of the metal is 60.2%, and at the processing temperature, it is in a solid-liquid coexistence state, with corresponding warpages of 0.2%, 0.4%, 0.4%, and 0.5%, and corresponding resistivities of 10⁻⁶. 6 Ω·cm, 10 -3 Ω·cm, 10 -4 Ω·cm, 10 -5 Ω·cm.

[0055] Example 5

[0056] According to the proportions in Example 3 of Table 1, the modifier KH-310, methanol, and water in Example 3 were mixed at a volume ratio of 1:3:96. The resistivity after printing was 10 Ω·cm.

[0057] Example 6

[0058] According to the proportions in Example 3 of Table 1, the modifier KH-310, methanol, and water in Example 3 were mixed at a volume ratio of 10:50:40. The resistivity after printing was 10 Ω·cm. -4 Ω·cm.

[0059] Example 7

[0060] A method for preparing a metal-polymer composite material that can be used for 3D printing includes the following steps:

[0061] (1) Metallic In and metallic Bi were weighed in an atomic ratio of 11:9, heated to 272℃ and melted to form an In0.Bi0.6 alloy, coated on release paper, peeled off after cooling, ground and passed through a 100-mesh sieve;

[0062] (2) The In0.55Bi0.45 alloy was modified at room temperature using KH-330 as the modifier. KH-330, ethylene glycol, and water were mixed at a volume ratio of 5:20:75 and magnetically stirred at 600 rpm for 4 hours at room temperature. Then, In0.4Bi0.6 alloy was added and stirring continued for 30 minutes. The mass ratio of the metal alloy to the hydrolysate was 150%. Finally, the supernatant was poured off and the mixture was placed in an oven at 100℃ for 1 hour to obtain the modified In0.55Bi0.45 alloy.

[0063] (3) The polymer material is selected from thermoplastic polyurethane elastomer rubber (TPU), and polyamide wax is added. The mixture is heated and stirred to obtain the base material.

[0064] (4) Place the mixture of alloy and composite matrix into a twin-screw extruder, mix and granulate it through the twin-screw extruder, the extrusion temperature is 95℃ and the screw speed is 150 rpm, to obtain conductive 3D printing material, seal and package it for later use;

[0065] (5) The 3D printing material is printed by fused deposition modeling 3D printing method to obtain the finished product.

[0066] Example 8

[0067] The basic steps are the same as in Example 7, and the specific parameters are shown in Table 2.

[0068] Example 9

[0069] The basic steps are the same as in Example 7, and the specific parameters are shown in Table 2.

[0070] Example 10

[0071] The basic steps are the same as in Example 7, and the specific parameters are shown in Table 2.

[0072] Table 2

[0073]

[0074] For Examples 7-10, the basic steps are the same. At 95°C, the solid fraction of the metal is 64%. At the processing temperature, the warpage after printing is 0.5%, 0.6%, 0.6%, and 0.75%, respectively, with corresponding resistivities of 10⁻⁶. -1 Ω·cm, 10 -2 Ω·cm, 10 -2 Ω·cm, 10 -4 Ω·cm.

[0075] Example 11

[0076] A method for preparing a metal-polymer composite material that can be used for 3D printing includes the following steps:

[0077] (1) Metals Ga and Sn are weighed in an atomic ratio of 1:9, heated at 235°C, and melted together to form a Ga0.1Sn0.9 alloy. After cooling, the alloy is ground through a 150-mesh sieve.

[0078] (2) Ga0.1Sn0.9 alloy powder with a particle size of less than or equal to 0.1 mm was modified in KH-310 modifying reagent. At this time, the solid phase of Ga0.1Sn0.9 alloy was 32.5%. KH-310, methanol and water were mixed in a volume ratio of 5:75:20. The pH of the solution was adjusted to 5 by acetic acid. Then, the mixture was magnetically stirred at 600 rpm for 4 h. After that, Ga0.1Sn0.9 alloy was added and stirring was continued for 30 min. Finally, the supernatant was poured off and placed in an oven at 100℃ for 0.1 h to obtain the modified Ga0.1Sn0.9 alloy.

[0079] (3) The Ga0.1Sn0.9 alloy, polylactic acid powder and fumed silica powder were heated and melted at 180℃. At this time, the viscosity of the alloy was 112 Pa·S and the viscosity of the polymer was 102 Pa·S.

[0080] (4) Place the mixture in a twin-screw extruder and granulate it through the twin-screw extruder. The extrusion temperature is 180 degrees Celsius and the screw speed is 200 rpm to obtain conductive 3D printing material. Seal and package it for later use.

[0081] (5) The 3D printing material is printed by fused deposition modeling 3D printing method to obtain the finished product.

[0082] Example 12

[0083] The basic steps are the same as in Example 11, and the specific parameters are shown in Table 3.

[0084] Example 13

[0085] The basic steps are the same as in Example 11, and the specific parameters are shown in Table 3.

[0086] Figure 2 The finished product prepared by extrusion in this embodiment is from... Figure 2 As can be seen from a, b, and c, the printed 3D shape is controllable, has clear boundaries, and has high conductivity.

[0087] Example 14

[0088] The basic steps are the same as in Example 11, and the specific parameters are shown in Table 3.

[0089] Table 3

[0090]

[0091] For Examples 11-14, the solid fraction of the metal at 180°C was 32.5%, and it was in a solid-liquid coexistence state at the processing temperature, with corresponding resistivities of 10⁻⁶. -3 Ω·cm, 10 -4Ω·cm, 10 -5 Ω·cm, 10 -6 Ω·cm.

[0092] Example 15

[0093] A method for preparing a metal-polymer composite material that can be used for 3D printing includes the following steps:

[0094] (1) Metallic Ga and metallic In were weighed in an atomic ratio of 3:7 and heated at 160℃ with N2 to melt and mix them into Ga. 0.3 In 0.7 The alloy was continuously stirred during the cooling process to room temperature to obtain metal powder.

[0095] (2) For Ga 0.3 In 0.7 The alloy was modified at room temperature using KH-310 as the modifier. KH-310, methanol, and water were mixed at a volume ratio of 5:20:75 and then magnetically stirred at 600 rpm for 4 hours at room temperature. Ga was then added. 0.3 In 0.7 The alloy was stirred for another 30 minutes, with the metal alloy comprising 95% of the hydrolysate by mass. Finally, the supernatant was poured off, and the mixture was placed in an oven at 100°C for 1 hour to obtain the modified Ga. 0.3 In 0.7 alloy;

[0096] (3) PCL was selected as the polymer material, and the modified Ga was then applied. 0.3 In 0.7 The alloy, PCL powder, and polyamide wax are heated to 70°C and then melted and mixed.

[0097] (4) Place the mixture in a twin-screw extruder and granulate it through the twin-screw extruder. The extrusion temperature is 70℃ and the screw speed is 150 rpm to obtain conductive 3D printing material. Seal and package it for later use.

[0098] (5) The 3D printing material is printed by fused deposition modeling 3D printing method to obtain the finished product.

[0099] Example 16

[0100] The basic steps are the same as in Example 15, and the specific parameters are shown in Table 4.

[0101] Example 17

[0102] The basic steps are the same as in Example 15, and the specific parameters are shown in Table 4.

[0103] Table 4

[0104]

[0105] For Examples 15-17, the basic steps are the same. At 70°C, the solid fraction of the metal is 36.4%, and at the processing temperature, it is in a solid-liquid coexistence state, with corresponding resistivities of 10⁻⁶. -2 Ω·cm, 10 -2 Ω·cm, 10 -4 Ω·cm.

[0106] Comparative Example 1

[0107] Following the formulation ratio in Example 3 of Table 1, the modifier in Example 3 was removed. During printing, the semi-solid metal alloy and polymer substrate separated into phases after a period of time, resulting in uneven printing. Simultaneously, 3D printing nozzle clogging occurred, and metal aggregated and settled at the bottom.

[0108] Comparative Example 2

[0109] Following the proportions in Example 9 of Table 2, the modifier in Example 9 was removed. During melt mixing, the semi-solid metal alloy and polymer substrate were not mixed uniformly, and the presence of metal particles was clearly visible. The printed product had poor conductivity and could not conduct electricity continuously. Additionally, 3D printing nozzle clogging and instances where only polymer material was ejected also occurred.

[0110] Comparative Example 3

[0111] According to the proportions in Example 13 in Table 3, the modifier in Example 13 was removed. During melt mixing, the semi-solid metal alloy and the polymer substrate can be mixed, but during 3D printing, the metal alloy and polymer material separate. Only polylactic acid material is intermittently extruded at the 3D printing nozzle, and patterns cannot be printed, nor can it conduct electricity.

[0112] Comparative Example 4

[0113] According to the proportions in Example 16 in Table 4, the modifier in Example 16 was removed. During melt mixing, the semi-solid metal alloy and the polymer substrate can mix, but during 3D printing, the metal alloy agglomerates in the printed pattern, distributed in one area, resulting in uneven mixing and discontinuous conductivity.

[0114] Comparative Example 5

[0115] The basic steps are the same as in Example 3, as shown in Table 5.

[0116] Table 5

[0117]

[0118] At 30°C, the solid fraction of the metal is 35.3%, and it exists in a solid-liquid coexistence state at the processing temperature. During the preparation process, the metal alloy overflows, resulting in metal waste and an excessively high metal volume fraction.

[0119] Comparative Example 6

[0120] The basic steps are the same as in Example 13, as shown in Table 6.

[0121] Table 6

[0122]

[0123] At 180℃, the solid fraction of the metal is 32.5%. At the processing temperature, it is in a solid-liquid coexistence state. During the preparation process, the metal alloy overflows, and the metal accounts for too high a volume fraction, resulting in metal waste.

[0124] Comparative Example 7

[0125] The basic steps are the same as in Example 13, as shown in Table 7.

[0126] Table 7

[0127]

[0128] At 180℃, metallic Ga is a pure liquid, not a solid-liquid coexistence state, and its viscosity differs greatly from that of polymer PLA, making it impossible to melt and mix.

[0129] Comparative Example 8

[0130] The basic steps are the same as in Example 13, as shown in Table 8.

[0131] Table 8

[0132]

[0133] At 180℃, 0.1mm diameter Cu particles are solid and can be printed, but they are not conductive. The cross-section clearly shows that the particles are simply encapsulated in PLA and are not mixed.

Claims

1. A method for preparing a metal-polymer composite material for 3D printing, characterized in that, Includes the following steps: (1) Metals Ga and Sn are weighed in an atomic ratio of 4:6 and heated to 235℃ to melt and mix into Ga. 0.4 Sn 0.6 The alloy was continuously stirred during the cooling process to room temperature to obtain metal powder. (2) For Ga 0.4 Sn 0.6 The alloy was modified at room temperature using KH-310 as the modifier. (3) Polydimethylsiloxane (PDMS) and its curing agent were selected as the polymer material, and BYK-410 additive was added. The mixture was mechanically stirred at high speed for 1500 rpm for 12 min to obtain the mixture base. (4) Modify Ga 0.4 Sn 0.6 The alloy and the mixed substrate are ground and fully dispersed, then introduced into a 3D printing machine for fused deposition modeling rapid 3D printing at room temperature. After printing, the shaped material is heated and cured. The volume fractions of the components in the composite material used for 3D printing are as follows: modified semi-solid metal alloy 10% ~ 65%; polymer material 25% ~ 89%; BYK-410 0 ~ 10%.

2. A method for preparing a metal-polymer composite material for 3D printing, characterized in that, Includes the following steps: (1) Metallic In and metallic Bi were weighed in an atomic ratio of 11:9 and heated to 272℃ to melt and mix into In. 0.55 0.Bi 0.45 The alloy is coated onto release paper, cooled, peeled off, ground, and then passed through a 100-mesh sieve. (2) For In 0.55 Bi 0.45 The alloy was modified at room temperature using KH-330 as the modifier. (3) The polymer material is selected from thermoplastic polyurethane elastomer rubber TPU, and then polyamide wax is added. The mixture is heated and stirred to obtain the base material. (4) Place the mixture of alloy and composite matrix into a twin-screw extruder, mix and granulate it through the twin-screw extruder, the extrusion temperature is 95℃ and the screw speed is 150 rpm, to obtain conductive 3D printing material, seal and package it for later use; (5) The 3D printing material is printed using the fused deposition modeling (FDM) rapid prototyping 3D printing method to obtain the finished product; The volume fractions of the components in the composite material used for 3D printing are as follows: modified semi-solid metal alloy 10% ~ 65%; polymer material 25% ~ 89%; polyamide wax 0 ~ 10%.

3. A method for preparing a metal-polymer composite material for 3D printing, characterized in that, Includes the following steps: (1) Metals Ga and Sn are weighed in an atomic ratio of 1:9, heated at 235℃, and melted together to form Ga. 0.1 Sn 0.9 The alloy, after cooling, is ground through a 150-mesh sieve; (2) Ga particles with a diameter of less than or equal to 0.1 mm 0.1 Sn 0.9 The alloy powder was modified in KH-310 modifying agent; (3) Ga 0.1 Sn 0.9 The alloy, polylactic acid powder, and fumed silica powder were heated and melted together at 180°C. At this time, the viscosity of the alloy was 112 Pa·S and the viscosity of the polymer was 102 Pa·S. (4) Place the mixture in a twin-screw extruder and granulate it through the twin-screw extruder. The extrusion temperature is 180 degrees Celsius and the screw speed is 200 rpm to obtain conductive 3D printing material. Seal and package it for later use. (5) The 3D printing material is printed using the fused deposition modeling (FDM) rapid prototyping 3D printing method to obtain the finished product; The volume fractions of the components in the composite material used for 3D printing are as follows: modified semi-solid metal alloy 10% ~ 65%; polymer material 25% ~ 89%; fumed silica 0 ~ 10%.

4. A method for preparing a metal-polymer composite material for 3D printing, characterized in that, Includes the following steps: (1) Metallic Ga and metallic In were weighed in an atomic ratio of 3:7 and heated to 160°C with N2 to melt and mix them into Ga. 0.3 In 0.7 The alloy was continuously stirred during the cooling process to room temperature to obtain metal powder. (2) For Ga 0.3 In 0.7 The alloy was modified at room temperature using KH-310 as the modifier. (3) The polymer material selected is PCL. The modified Ga0.3In0.7 alloy, PCL powder and polyamide wax are heated and melted at 70°C. (4) Place the mixture in a twin-screw extruder and granulate it through the twin-screw extruder. The extrusion temperature is 70℃ and the screw speed is 150 rpm to obtain conductive 3D printing material. Seal and package it for later use. (5) The 3D printing material is printed using the fused deposition modeling (FDM) rapid prototyping 3D printing method to obtain the finished product; The volume fractions of the components in the composite material used for 3D printing are as follows: modified semi-solid metal alloy 10% ~ 65%; polymer material 25% ~ 89%; polyamide wax 0 ~ 10%.

5. The method for preparing the metal-polymer composite material for 3D printing according to any one of claims 1-4, characterized in that, The specific preparation process of the modified semi-solid metal alloy is as follows: the coupling agent, alcohol and water are mixed and hydrolyzed to obtain a hydrolysate. Then, the semi-solid metal alloy is placed in the hydrolysate, stirred, washed and dried to obtain the modified semi-solid metal alloy.

6. The method for preparing the metal-polymer composite material for 3D printing according to claim 5, characterized in that, Acetic acid is added to the hydrolysate.

7. The method for preparing the metal-polymer composite material for 3D printing according to claim 5, characterized in that, The semi-solid metal alloy accounts for a mass fraction of more than 0 and less than 200% of the hydrolysate.

8. A metal polymer composite material for 3D printing obtained by the method according to any one of claims 1-4.

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