Composite material for 3D printing and method for its preparation and use

Abstract

The application provides a composite material for 3D printing and a preparation method and application thereof, and belongs to the technical field of 3D printing materials. The preparation raw material of the composite material for 3D printing comprises the following components: isocyanate group terminated prepolymer, amino silane coupling agent modified nano alumina and capping agent; the mass percentage content of the amino silane coupling agent modified nano alumina is 3-10% based on 100% of the mass percentage content of the isocyanate group terminated prepolymer. The preparation method comprises the following steps: reacting the isocyanate group terminated prepolymer, the amino silane coupling agent modified nano alumina solution and the catalyst to obtain an intermediate product; then adding the capping agent to the intermediate product to perform capping reaction, and the composite material for 3D printing is obtained. The application grafts the nano alumina into the isocyanate group terminated prepolymer, and the composite material for 3D printing with excellent performance is prepared.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of 3D printing materials, and particularly relates to a composite material for 3D printing and a preparation method and application thereof. BACKGROUND

[0002] 3D printing technology, also known as additive manufacturing technology, is actually a new technology in the field of rapid prototyping. It is a technology that uses powder-like metal or plastic and other materials that can be bonded to construct objects through layer-by-layer printing based on digital model files. The basic principle is layer manufacturing, which generates a three-dimensional entity by layer-by-layer material addition. At present, 3D printing technology is mainly applied to product prototyping, mold manufacturing, and artistic creation, jewelry making, etc., replacing these traditional fine processing technologies. In addition, 3D printing technology is gradually applied to the fields of medicine, biological engineering, architecture, clothing, aviation, batteries, optical sensors, etc., and has opened up a broad space for innovation.

[0003] With the rapid development of electronic technology, 3D printing technology is gradually applied to the fields of temporary protection of batteries and white surface protection of optical sensors, which requires 3D printing materials to have high hardness, high light transmittance, low haze and good wear resistance. However, the 3D printing materials provided by the prior art have poor hardness, light transmittance and wear resistance.

[0004] Therefore, how to provide a 3D printing material with high hardness, high light transmittance, low haze and good wear resistance has become a technical problem to be solved at present. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a composite material for 3D printing and a preparation method and application thereof. The present application designs the raw materials for preparing the composite material for 3D printing, and further uses isocyanate-terminated prepolymer and amino silane coupling agent modified nano-alumina to graft nano-alumina into isocyanate-terminated prepolymer, thereby preparing a composite material for 3D printing with excellent performance.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a composite material for 3D printing, and the raw materials for preparing the composite material for 3D printing comprise the following components:

[0008] isocyanate-terminated prepolymer, amino silane coupling agent modified nano-alumina and end-capping agent;

[0009] The mass percentage content of the amino silane coupling agent modified nano-alumina is 3-10% based on 100% of the mass percentage content of the isocyanate group terminated prepolymer.

[0010] The end-capping agent is selected from any one or a combination of at least two of hydroxyethyl acrylate, hydroxypropyl acrylate or hydroxyethyl methacrylate.

[0011] The present application designs the raw materials for the preparation of the composite material for 3D printing, and further uses the isocyanate group terminated prepolymer and the amino silane coupling agent modified nano-alumina to graft the nano-alumina into the isocyanate group terminated prepolymer, so that the 3D printing material prepared from the composite material for 3D printing provided by the present application has good stability, and effectively avoids the occurrence of the settlement of the 3D printing material and the plugging of the nozzle in the case of long-term continuous 3D printing. The present application introduces the unsaturated bond into the composite material for 3D printing by using the end-capping agent, so that it can be used for 3D printing.

[0012] The present application designs the raw materials for the preparation of the composite material for 3D printing, and further uses the isocyanate group terminated prepolymer and the amino silane coupling agent modified nano-alumina to graft the nano-alumina into the isocyanate group terminated prepolymer, so that the 3D printing material prepared from the composite material for 3D printing provided by the present application has good stability, and effectively avoids the occurrence of the settlement of the 3D printing material and the plugging of the nozzle in the case of long-term continuous 3D printing. The present application introduces the unsaturated bond into the composite material for 3D printing by using the end-capping agent, so that it can be used for 3D printing.

[0013] Further, the present application controls the amount of the amino silane coupling agent modified nano-alumina in the composite material for 3D printing within a specific range, and prepares the composite material for 3D printing with excellent comprehensive performance. If the amount of the amino silane coupling agent modified nano-alumina is too small, the hardness and wear resistance of the composite material for 3D printing prepared are poor. If the amount of the amino silane coupling agent modified nano-alumina is too large, the hardness of the composite material for 3D printing prepared is too high, and the material may crack in the subsequent 3D printing process.

[0014] The composite material for 3D printing provided by the present application can be used to prepare 3D printing material, temporarily protect electronic components, and protect the surface of optical sensors, etc. 3D printing makes it have more customized applications.

[0015] The mass percentage content of the amino silane coupling agent modified nano-alumina is 3-10% based on 100% of the mass percentage content of the isocyanate group terminated prepolymer, for example, it can be 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, etc.

[0016] The following is a preferred technical solution of the present application, but is not a limitation on the technical solution provided by the present application. Through the following preferred technical solution, the purpose and beneficial effects of the present application can be better achieved and realized.

[0017] As a preferred technical solution of the present application, the raw material for preparing the isocyanate-terminated prepolymer comprises a polyol and a diisocyanate.

[0018] Preferably, the molar ratio of the hydroxyl group in the polyol to the isocyanate group in the diisocyanate is ≤0.5, for example, it can be 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5, etc.

[0019] Preferably, the molar ratio of the hydroxyl group in the polyol to the isocyanate group in the diisocyanate is (0.3-0.5):1, for example, it can be 0.3:1, 0.32:1, 0.34:1, 0.36:1, 0.38:1, 0.4:1, 0.42:1, 0.44:1, 0.46:1, 0.48:1, or 0.5:1, etc.

[0020] Preferably, the polyol is selected from any one or a combination of at least two of polytetramethylene ether glycol (including but not limited to: PTMEG650), polytrimethylene ether glycol (including but not limited to: PO3G1000), polycaprolactone glycol (including but not limited to: PCL1000), polyhexanediol adipate, or polycarbonate diol.

[0021] Preferably, the weight average molecular weight of the diol is 500-1000, for example, it can be 500, 610, 650, 680, 730, 820, 880, 930, 900, or 1000, etc.

[0022] In the present application, the weight average molecular weight of the diol is tested by using Agilent 1260I machine GPC detector and Agilent polystyrene reagent as a standard sample method.

[0023] Preferably, the diisocyanate is selected from any one or a combination of at least two of isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tetramethylxylylene diisocyanate (TMXDI), m-xylylene diisocyanate (XDI), dicyclohexylmethane diisocyanate (HMDI), or pentamethylene diisocyanate (PDI).

[0024] As a preferred technical solution of the present application, the isocyanate-terminated prepolymer is prepared by the following method, which comprises the following steps:

[0025] Mixing the diisocyanate and the polyol, and reacting to obtain the isocyanate-terminated prepolymer;

[0026] Preferably, the temperature of the reaction is ≤ 80℃ (for example, it can be 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃, or 80℃, etc.), and the reaction time is 3-5h (for example, it can be 3h, 3.5h, 4h, 4.5h, or 5h, etc.).

[0027] Preferably, the method further comprises a pretreatment step before the reaction, and the pretreatment method comprises drying the polyol.

[0028] Preferably, the temperature of the dried polyol is 40-60℃ (for example, it can be 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, or 60℃, etc.), and the time is 8-12h (for example, it can be 8h, 9h, 10h, 11h, or 12h, etc.).

[0029] Preferably, the method further comprises a post-treatment step after the reaction, and the post-treatment method comprises cooling to 35-45℃, for example, it can be 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃, or 45℃, etc.

[0030] As a preferred technical solution of the present application, the preparation raw material of the amino silane coupling agent modified nano alumina comprises nano alumina and an amino silane coupling agent.

[0031] Preferably, the mass ratio of the nano alumina and the amino silane coupling agent is 1:(0.8-1.2), for example, it can be 1:0.8, 1:0.81, 1:0.84, 1:0.86, 1:0.88, 1:0.9, 1:0.93, 1:0.96, 1:0.98, 1:1, 1:1.02, 1:1.05, 1:1.08, 1:1.1, 1:1.13, 1:1.15, 1:1.18, or 1:1.2, etc.

[0032] Preferably, the D50 particle size of the nano alumina is ≤ 150nm, for example, it can be 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, or 150nm, etc.

[0033] Preferably, the D50 particle size of the nano alumina is 30-150nm (for example, it can be 50nm, 52nm, 64nm, 66nm, 78nm, 80nm, 82nm, 94nm, 96nm, 98nm, or 100nm, etc.), and further preferably 50-150nm.

[0034] The present application controls the D50 particle size of nano-alumina in a specific range, and the prepared 3D printed composite material has excellent comprehensive performance.

[0035] Preferably, the amino silane coupling agent is selected from any one or a combination of at least two of gamma-aminopropyl triethoxysilane (KH550), N-(beta-aminoethyl)-gamma-aminopropyl trimethoxysilane (KH572), 3-aminopropyl trimethoxysilane (APS), N-(beta-aminoethyl)-gamma-aminopropyl triethoxysilane (KH791), gamma-aminopropyl methyldiethoxysilane, or gamma-aminopropyl methyldimethoxysilane.

[0036] Preferably, the amino silane coupling agent is selected from a combination of gamma-aminopropyl triethoxysilane and gamma-aminopropyl methyldiethoxysilane.

[0037] Preferably, the mass ratio of the gamma-aminopropyl triethoxysilane and the gamma-aminopropyl methyldiethoxysilane is 1:(0.5-1.5), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, or 1:1.5, etc.

[0038] In the present application, by selecting a combination of gamma-aminopropyl triethoxysilane and gamma-aminopropyl methyldiethoxysilane as the amino silane coupling agent for modifying nano-alumina, and controlling the mass ratio of the gamma-aminopropyl triethoxysilane and the gamma-aminopropyl methyldiethoxysilane within a specific range, the comprehensive performance of the composite material for 3D printing is further improved.

[0039] As a preferred technical solution of the present application, the nano-alumina modified by the amino silane coupling agent is prepared by the following method, which comprises the following steps:

[0040] (1) After uniformly mixing the nano-alumina and the solvent A, filtering, standing, and performing plasma treatment;

[0041] (2) Mixing the nano-alumina after plasma treatment, the amino silane coupling agent, and the solvent B, and performing modification reaction to obtain the nano-alumina modified by the amino silane coupling agent.

[0042] Preferably, the solvent A and the solvent B are each independently selected from any one or a combination of at least two of xylene, propylene glycol methyl ether acetate, or dipropylene glycol butyl ether acetate.

[0043] Preferably, the mass ratio of the nano-alumina and the solvent A is 1:(8-10), for example, it can be 1:8, 1:8.2, 1:8.4, 1:8.6, 1:8.8, 1:9, 1:9.2, 1:9.4, 1:9.6, 1:9.8 or 1:10, etc.

[0044] Preferably, the mass ratio of the nano-alumina and the solvent B is 1:(0.2-0.3), for example, it can be 1:0.2, 1:0.21, 1:0.22, 1:0.23, 1:0.24, 1:0.25, 1:0.26, 1:0.27, 1:0.28, 1:0.29 or 1:0.3, etc.

[0045] Preferably, the method of the plasma treatment comprises using a plasma treatment machine for the treatment.

[0046] Preferably, the power in the plasma treatment is 30-200W, for example, it can be 30W, 40W, 60W, 80W, 100W, 120W, 140W, 160W, 180W or 200W, etc.

[0047] Preferably, the plasma treatment is carried out in a protective atmosphere, and the protective gas comprises at least one of air, nitrogen or argon.

[0048] Preferably, the flow rate of the protective gas in the plasma treatment process is 0-500mL / min, for example, it can be 0mL / min, 50mL / min, 100mL / min, 150mL / min, 200mL / min, 250mL / min, 300mL / min, 350mL / min, 400mL / min, 450mL / min or 500mL / min, etc.

[0049] Preferably, the time of the plasma treatment is 30-200 seconds, for example, it can be 30 seconds, 50 seconds, 80 seconds, 100 seconds, 120 seconds, 150 seconds, 170 seconds or 200 seconds, etc.

[0050] Preferably, the temperature of the modification reaction is 100-130℃ (for example, it can be 100℃, 105℃, 110℃, 115℃, 120℃, 125℃ or 130℃, etc.), and the time is 8-15h (for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h, etc.).

[0051] Preferably, the modification reaction further comprises a post-treatment step, and the method of the post-treatment comprises filtration, washing and drying.

[0052] As a preferred technical solution of the present application, the raw material for preparing the composite material for 3D printing further comprises a catalyst.

[0053] Preferably, the catalyst comprises any one or a combination of at least two of an organotin catalyst, an organobismuth catalyst or an organoamine catalyst, further preferably dibutyltin dilaurate and / or stannous octoate.

[0054] Preferably, the mass percentage content of the catalyst is 0.03-0.3% based on 100% of the mass percentage content of the isocyanate group-terminated prepolymer, for example, can be 0.03%, 0.05%, 0.1%, 0.15%, 0.18%, 0.2%, 0.25% or 0.3%, etc.

[0055] In a second aspect, the present application provides a preparation method of the composite material for 3D printing according to the first aspect, the preparation method comprising the following steps:

[0056] (S1) mixing the amino silane coupling agent modified nano-alumina and the solvent C to obtain an amino silane coupling agent modified nano-alumina solution;

[0057] mixing the isocyanate group-terminated prepolymer, the amino silane coupling agent modified nano-alumina solution and the catalyst, and reacting to obtain an intermediate product;

[0058] (S2) mixing the intermediate product and the end-capping agent to perform an end-capping reaction to obtain the composite material for 3D printing.

[0059] As a preferred technical solution of the present application, the solvent C is selected from any one or a combination of at least two of xylene, propylene glycol methyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate or DBE (a mixture of dibasic acid esters).

[0060] It should be noted that the present application does not have any special restrictions on the amount of solvent C, and the commonly used amount range in the art is applicable.

[0061] Preferably, the temperature of the reaction in step (S1) is 50-80°C (for example, can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, etc.), and the reaction time is 1-10h (for example, can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, etc.).

[0062] Preferably, the molar ratio of the hydroxyl group in the end-capping agent to the isocyanate group in the intermediate product in step (S2) is 1:(1-1.05), for example, can be 1:1, 1:1.01, 1:1.02, 1:1.03, 1:1.04 or 1:1.05, etc.

[0063] Preferably, the temperature of the end-capping reaction in step (S2) is 50-80℃ (for example, it can be 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃, etc.), and the time is 3-8h (for example, it can be 3h, 4h, 5h, 6h, 7h or 8h, etc.).

[0064] Preferably, after the end-capping reaction, a post-treatment step is further included, and the method of the post-treatment includes reduced-pressure rotary evaporation.

[0065] Preferably, the temperature of the reduced-pressure rotary evaporation is 70-75℃, for example, it can be 70℃, 71℃, 72℃, 73℃, 74℃ or 75℃, etc.

[0066] Preferably, after the reduced-pressure rotary evaporation, the mass percentage of the solvent C in the composite material for 3D printing is ≤0.5% (for example, it can be 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, etc.) based on 100% of the mass percentage of the composite material for 3D printing.

[0067] In the present application, the solvent C is removed by reduced-pressure rotary evaporation, and the mass percentage of the solvent C in the composite material for 3D printing is controlled to be ≤0.5%, so as to avoid the problem of structural collapse of the 3D printed part due to excessive content of the solvent C in the subsequent 3D printing process.

[0068] In a third aspect, the present application provides a 3D printing material, which comprises the following components in parts by weight:

[0069] The composite material according to the first aspect 30-70 parts;

[0070] The photocurable monomer 30-70 parts;

[0071] The photoinitiator 1-3 parts.

[0072] The composite material provided by the present application is used to prepare a 3D printing material, and the prepared 3D printing material has good stability, which effectively avoids the occurrence of the problems of sedimentation and clogging of the nozzle of the 3D printing material in the case of long-term continuous 3D printing.

[0073] In the present application, the weight parts of the composite material according to the first aspect in the 3D printing material can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts, etc.

[0074] The weight parts of the photocurable monomer in the 3D printing material can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts, etc.

[0075] The weight fraction of the photoinitiator in the 3D printing material can be 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, or 3 parts, etc.

[0076] As a preferred technical solution of the present application, the photocurable monomer comprises an acrylic monomer and / or an acrylate monomer.

[0077] It should be noted that the present application does not have any special restrictions on the specific selection of the acrylic monomer and the acrylate monomer, and the commonly used acrylic monomers and acrylate monomers in the art are all applicable. The acrylic monomer exemplarily includes but is not limited to acrylic acid, methacrylic acid, etc.; the acrylate monomer exemplarily includes but is not limited to glycidyl methacrylate, 3-ethyl-3-epoxypropyl methacrylate, trimethylolpropane formal acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, dipentaerythritol diacrylate, 1,6-ethanediol diacrylate, tricyclodecane dimethanol diacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, triallyl isocyanurate, etc.

[0078] As a preferred technical solution of the present application, the photoinitiator comprises a free radical photoinitiator and / or a cationic photoinitiator.

[0079] It should be noted that the present application does not have any special restrictions on the specific selection of the free radical photoinitiator and the cationic photoinitiator, and the commonly used free radical photoinitiators and cationic photoinitiators in the art are all applicable. The free radical photoinitiator exemplarily includes but is not limited to 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide, 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester, etc.; the acrylate monomer exemplarily includes but is not limited to ferrocenium salt, triaryl sulfonium salt, etc.

[0080] Compared with the prior art, the present application has the following beneficial effects:

[0081] (1) The present application designs the raw materials for preparing the composite material for 3D printing, grafts nano-alumina into the pre-polymer terminated by isocyanate groups, and prepares the composite material for 3D printing with excellent performance.

[0082] (2) The present application can further control the D50 particle size of nano-alumina within a specific range, and selects the combination of γ-aminopropyl triethoxysilane and γ-aminopropyl methyl diethoxysilane as the amino silane coupling agent for modifying the nano-alumina, and controls the mass ratio of γ-aminopropyl triethoxysilane and γ-aminopropyl methyl diethoxysilane within a specific range, thereby further improving the comprehensive performance of the composite material for 3D printing. DETAILED DESCRIPTION

[0083] For the purpose of understanding the present application, the present application is illustrated with the following examples. It should be apparent to those skilled in the art that the examples are merely illustrative of the present application and should not be viewed as limiting the present application.

[0084] The sources of some components in the examples and comparative examples are shown in Table 1 below:

[0085] Table 1

[0086]

[0087] Preparation Example A

[0088] The present preparation example provides an isocyanate-terminated prepolymer 1 and a method for preparing the isocyanate-terminated prepolymer 1, the method for preparing the isocyanate-terminated prepolymer 1 being as follows:

[0089] After drying the polytetramethylene ether glycol at 50℃ for 10h, mixing isophorone diisocyanate and the polytetramethylene ether glycol, controlling the temperature at 70℃, and reacting for 4h, then cooling to 40℃, an isocyanate-terminated prepolymer 1 is obtained.

[0090] The molar ratio of the hydroxyl group in the polytetramethylene ether glycol to the isocyanate group in the isophorone diisocyanate is 0.4:1.

[0091] Preparation Example B

[0092] The present preparation example provides an isocyanate-terminated prepolymer 2 and a method for preparing the isocyanate-terminated prepolymer 2, the method for preparing the isocyanate-terminated prepolymer 2 being as follows:

[0093] After drying the polytrimethylene ether glycol at 60℃ for 8h, mixing hexamethylene diisocyanate and the polytrimethylene ether glycol, controlling the temperature at 75℃, and reacting for 4h, then cooling to 40℃, an isocyanate-terminated prepolymer 2 is obtained.

[0094] The molar ratio of the hydroxyl group in the polytrimethylene ether glycol to the isocyanate group in the hexamethylene diisocyanate is 0.5:1.

[0095] Preparation Example C

[0096] The present preparation example provides an isocyanate-terminated prepolymer 3 and a method for preparing the isocyanate-terminated prepolymer 3, the method for preparing the isocyanate-terminated prepolymer 3 being as follows:

[0097] After drying polycaprolactone diol at 50℃ for 11h, mixing di-m-xylylene isocyanate and polycaprolactone diol, controlling the temperature at 80℃, and reacting for 4h, then cooling to 40℃, an isocyanate group terminated prepolymer 3 is obtained;

[0098] The molar ratio of the hydroxyl group in the polycaprolactone diol and the isocyanate group in the m-xylylene isocyanate is 0.3:1.

[0099] Preparation Example 1

[0100] The present preparation example provides a kind of amino silane coupling agent modified nano alumina 1 and its preparation method, the preparation method of the amino silane coupling agent modified nano alumina 1 as follows:

[0101] (1) after mixing nano alumina 2 (10g) and dimethylbenzene (90g) uniformly, filtering, standing, using plasma processing machine to carry out plasma treatment, the power of plasma treatment is set to 80W, nitrogen is passed, and the flow is 300mL / min, time 120 seconds;

[0102] (2) then mixing the nano alumina 2 after plasma treatment, γ-aminopropyl triethoxysilane (5g), γ-aminopropyl methyl diethoxysilane (5g), dimethylbenzene (3g), after modification reaction 8h at 110℃, filtering, washing, drying, to obtain the amino silane coupling agent modified nano alumina 2.

[0103] Preparation Example 2

[0104] The present preparation example provides a kind of amino silane coupling agent modified nano alumina 2 and its preparation method, the preparation method of the amino silane coupling agent modified nano alumina 2 as follows:

[0105] (1) after mixing nano alumina 2 (10g) and dimethylbenzene (90g) uniformly, filtering, standing, using plasma processing machine to carry out plasma treatment, the power of plasma treatment is set to 70W, nitrogen is passed, and the flow is 500mL / min, time 80 seconds;

[0106] (2) then mixing the nano alumina 2 after plasma treatment, γ-aminopropyl triethoxysilane (4g), γ-aminopropyl methyl diethoxysilane (4.5g), dimethylbenzene (3g), after modification reaction 8h at 110℃, filtering, washing, drying, to obtain the amino silane coupling agent modified nano alumina 2.

[0107] Preparation Example 3

[0108] The present preparation example provides a kind of amino silane coupling agent modified nano alumina 3 and its preparation method, the preparation method of the amino silane coupling agent modified nano alumina 3 as follows:

[0109] (1) The nano-alumina 2 (10 g) and propylene glycol methyl ether acetate (90 g) were mixed uniformly, filtered, and left to stand, and then plasma treatment was performed using a plasma treatment machine, with a power of 100 W, nitrogen flow of 400 mL / min, and a time of 150 seconds;

[0110] (2) Then the nano-alumina 2 after plasma treatment, γ-aminopropyl triethoxysilane (6.5 g), γ-aminopropyl methyl diethoxysilane (6.5 g), and propylene glycol methyl ether acetate (3 g) were mixed, and after modification reaction at 110°C for 8 h, filtration, washing, and drying were performed to obtain the amino silane coupling agent modified nano-alumina 3.

[0111] Preparation Examples 4-7

[0112] Preparation Examples 4-7 provide in turn an amino silane coupling agent modified nano-alumina 4-7 and a preparation method thereof, which are different from Preparation Example 1 only in that:

[0113] Preparation Example 4: The nano-alumina 2 was replaced with an equal amount of nano-alumina 3, and finally the amino silane coupling agent modified nano-alumina 4 was prepared;

[0114] Preparation Example 5: The nano-alumina 2 was replaced with an equal amount of nano-alumina 1, and finally the amino silane coupling agent modified nano-alumina 5 was prepared;

[0115] Preparation Example 6: The nano-alumina 2 was replaced with an equal amount of nano-alumina 4, and finally the amino silane coupling agent modified nano-alumina 6 was prepared;

[0116] Preparation Example 7: The nano-alumina 2 was replaced with an equal amount of nano-alumina 5, and finally the amino silane coupling agent modified nano-alumina 7 was prepared;

[0117] The other conditions were the same as those in Preparation Example 1.

[0118] Preparation Examples 8-11

[0119] Preparation Examples 8-11 provide in turn an amino silane coupling agent modified nano-alumina 8-11 and a preparation method thereof, which are different from Preparation Example 1 only in that:

[0120] Preparation Example 8: The mass of γ-aminopropyl triethoxysilane was 6.6 g, and the mass of γ-aminopropyl methyl diethoxysilane was 3.4 g, and finally the amino silane coupling agent modified nano-alumina 8 was prepared;

[0121] Preparation Example 9: The mass of γ-aminopropyltriethoxysilane is 4 g, the mass of γ-aminopropylmethyldiethoxysilane is 6 g, and finally the amino silane coupling agent modified nano alumina 9 is prepared;

[0122] Preparation Example 10: The mass of γ-aminopropyltriethoxysilane is 7.5 g, the mass of γ-aminopropylmethyldiethoxysilane is 2.5 g, and finally the amino silane coupling agent modified nano alumina 10 is prepared;

[0123] Preparation Example 11: The mass of γ-aminopropyltriethoxysilane is 3.5 g, the mass of γ-aminopropylmethyldiethoxysilane is 7.5 g, and finally the amino silane coupling agent modified nano alumina 11 is prepared;

[0124] Other conditions are the same as those in Preparation Example 1.

[0125] Preparation Examples 12-15

[0126] Preparation Examples 12-15 provide one kind of amino silane coupling agent modified nano alumina 12-15 and a preparation method thereof, which are different from Preparation Example 1 only in that:

[0127] Preparation Example 12: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) are replaced by γ-aminopropyltriethoxysilane (5 g) and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (5 g), and finally the amino silane coupling agent modified nano alumina 12 is prepared;

[0128] Preparation Example 13: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) are replaced by γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldimethoxysilane (5 g), and finally the amino silane coupling agent modified nano alumina 13 is prepared;

[0129] Preparation Example 14: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) are replaced by γ-aminopropyltriethoxysilane (10 g), and finally the amino silane coupling agent modified nano alumina 14 is prepared;

[0130] Preparation Example 15: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) are replaced by γ-aminopropylmethyldiethoxysilane (10 g), and finally the amino silane coupling agent modified nano alumina 15 is prepared;

[0131] Other conditions are the same as those in Preparation Example 1.

[0132] Example 1

[0133] The embodiment provides a composite material for 3D printing and a preparation method thereof, and the preparation method of the composite material for 3D printing is as follows:

[0134] (S1) mixing amino silane coupling agent modified nano alumina 1 (7g) and dimethylbenzene (100g) to obtain an amino silane coupling agent modified nano alumina solution;

[0135] Mixing isocyanate group terminated prepolymer 1 (100g), the amino silane coupling agent modified nano alumina solution and dibutyltin dilaurate (0.1g), and reacting at 70 DEG C for 6h to obtain an intermediate product;

[0136] (S2) mixing the intermediate product and hydroxyethyl acrylate, and performing a capping reaction at 70 DEG C for 6h, and then performing rotary evaporation under reduced pressure at 70 DEG C to obtain the composite material for 3D printing with a mass percentage content of dimethylbenzene of less than or equal to 0.5%;

[0137] The molar ratio of the hydroxyl group in the hydroxyethyl acrylate to the isocyanate group in the intermediate product is 1:1.02.

[0138] Embodiment 2

[0139] The embodiment provides a composite material for 3D printing and a preparation method thereof, and the preparation method of the composite material for 3D printing is as follows:

[0140] (S1) mixing amino silane coupling agent modified nano alumina 1 (5g) and dimethylbenzene (80g) to obtain an amino silane coupling agent modified nano alumina solution;

[0141] Mixing isocyanate group terminated prepolymer 2 (100g), the amino silane coupling agent modified nano alumina solution and dibutyltin dilaurate (0.3g), and reacting at 70 DEG C for 5h to obtain an intermediate product;

[0142] (S2) mixing the intermediate product and hydroxypropyl acrylate, and performing a capping reaction at 70 DEG C for 7h, and then performing rotary evaporation under reduced pressure at 75 DEG C to obtain the composite material for 3D printing with a mass percentage content of dimethylbenzene of less than or equal to 0.5%;

[0143] The molar ratio of the hydroxyl group in the hydroxypropyl acrylate to the isocyanate group in the intermediate product is 1:1.

[0144] Embodiment 3

[0145] The embodiment provides a composite material for 3D printing and a preparation method thereof, and the preparation method of the composite material for 3D printing is as follows:

[0146] (S1) mixing the amino silane coupling agent modified nano-alumina 1 (8 g) and xylene (90 g) to obtain an amino silane coupling agent modified nano-alumina solution;

[0147] mixing the isocyanate-terminated prepolymer 3 (100 g), the amino silane coupling agent modified nano-alumina solution, dibutyltin dilaurate (0.2 g) and reacting at 60 °C for 8 h to obtain an intermediate product;

[0148] (S2) mixing the intermediate product and hydroxyethyl acrylate, carrying out a capping reaction at 50 °C for 8 h, and then rotary evaporation under reduced pressure at 70 °C to obtain a composite material for 3D printing with a mass percentage content of xylene ≤0.5%;

[0149] wherein the molar ratio of the hydroxyl group in the hydroxyethyl acrylate to the isocyanate group in the intermediate product is 1:1.05.

[0150] Examples 4-15

[0151] Examples 4-15 respectively provide a composite material for 3D printing and a preparation method thereof, which are only different from Example 1 in that:

[0152] In Examples 4-15, the amino silane coupling agent modified nano-alumina 1 provided by Preparation Example 1 used in Example 1 is replaced by the amino silane coupling agent modified nano-alumina 4-15 provided by Preparation Examples 4-15 in turn;

[0153] The other conditions are the same as those in Example 1.

[0154] Examples 16-17 and Comparative Examples 1-2

[0155] Examples 16-17 and Comparative Examples 1-2 respectively provide a composite material for 3D printing and a preparation method thereof, which are only different from Example 1 in that:

[0156] Example 16: the mass of the amino silane coupling agent modified nano-alumina 1 in step (S1) is 3 g;

[0157] Example 17: the mass of the amino silane coupling agent modified nano-alumina 1 in step (S1) is 10 g;

[0158] Comparative Example 1: the mass of the amino silane coupling agent modified nano-alumina 1 in step (S1) is 1.5 g;

[0159] Comparative Example 2: the mass of the amino silane coupling agent modified nano-alumina 1 in step (S1) is 15 g;

[0160] The other conditions are the same as those in Example 1.

[0161] Comparative Example 3

[0162] The present comparative example provides a composite material for 3D printing and a preparation method thereof, the preparation method of the composite material for 3D printing being as follows:

[0163] (S2) mixing isocyanate group terminated prepolymer 1 (100 g) and hydroxyethyl acrylate, after end-capping reaction at 60°C for 3 h, an intermediate product is obtained;

[0164] The molar ratio of the hydroxyl group in the hydroxyethyl acrylate to the isocyanate group in the intermediate product is 1:1.02.

[0165] (S2) mixing nano-alumina 2 (7 g) and dimethylbenzene (80 g) to obtain a nano-alumina solution;

[0166] After the intermediate product and the nano-alumina solution are uniformly mixed, rotary evaporation under reduced pressure at 70°C is performed to obtain a composite material for 3D printing with a mass percentage content of dimethylbenzene ≤0.5%.

[0167] Comparative Example 4

[0168] The present comparative example provides a 3D printing material, which is purchased from Hangzhou Leiyi, with a trade name of LY8002.

[0169] Mixing the composite material for 3D printing (50 parts by weight) provided by the above-mentioned examples 1-17 and comparative examples 1-3 and glycidyl methacrylate (50 parts by weight), 2,4,6-trimethylbenzoyl diphenyl phosphine oxide (2 parts by weight) respectively to obtain a 3D printing material;

[0170] Using an SLA-3D printer, a film material with a length-width-height size of 0.1 m x 0.1 m x 60 μm is printed, and the following performance tests are performed:

[0171] (1) Hardness: GB / T 6739-2022 Paints and Varnishes, Determination of Film Hardness by Pencil Method, pencil hardness is tested with a 500 g load; when testing, a transparent glass plate is placed at the bottom, and then the film material to be tested is laid flat on the glass plate, and the pencil hardness is tested.

[0172] (2) Haze: using a scale TH-110 haze meter, after calibrating the blank, the reading is directly scanned.

[0173] (3) Light transmittance: using a scale TH-110 haze meter, after calibrating the blank, the reading is directly scanned.

[0174] (4) Wear resistance: referring to ASTM F2357-04, using an RCA paper tape machine, a 175 g load, 10 circles / min, testing the effect after 100 circles, the scratch from 0 level to 4 level is in turn serious, and 0 level is no scratch and 4 level is serious damage.

[0175] The performance test results are shown in Table 2 below:

[0176] Table 2

[0177] Hardness Haze / % Transmittance / % Abrasion resistance Example 1 3H 1.7 89 0 grade Example 2 3H 2.0 89 0 grade Example 3 3H 1.1 89 0 grade Example 4 3H 2.1 88 0 grade Example 5 2H 2.6 87 0 grade Example 6 2H 2.3 88 0 grade Example 7 2H 3.6 87 0 grade Example 8 2H 2.8 87 1 grade Example 9 2H 3.0 87 1 grade Example 10 2H 3.4 87 1 grade Example 11 2H 3.6 87 1 grade Example 12 2H 4.2 86 1 grade Example 13 2H 4.0 86 1 grade Example 14 2H 4.3 85 1 grade Example 15 2H 4.4 85 1 grade Example 16 2H 3.0 85 1 grade Example 17 3H 2.8 84 1 grade Comparative Example 1 1H 4.2 82 2 grade Comparative Example 2 4H 4.4 82 2 grade Comparative Example 3 1H 5.9 78 2 grade Comparative Example 4 1H 4.9 86 0 grade

[0178] From the above performance data, it can be seen that the composite material for 3D printing prepared by designing the raw materials for the composite material for 3D printing, through the cooperation of various components, and further by grafting nano-aluminum oxide into the isocyanate group terminated prepolymer, has excellent performance, the hardness is 2H or 3H, the haze is ≤4.4%, specifically 1.1-4.4%, the light transmittance is ≥84%, specifically 84-89%, and the wear resistance is 0 level or 1 level.

[0179] From Examples 1-15, it can be seen that the composite material for 3D printing prepared by further controlling the D50 particle size of nano-aluminum oxide within a specific range, and selecting the combination of γ-aminopropyl triethoxysilane and γ-aminopropyl methyldiethoxysilane as the amino silane coupling agent for modifying nano-aluminum oxide, and controlling the mass ratio of γ-aminopropyl triethoxysilane and γ-aminopropyl methyldiethoxysilane within a specific range, further improves the comprehensive performance of the composite material for 3D printing, the hardness is 2H or 3H, the haze is ≤3.0%, specifically 1.1-3.0%, the light transmittance is ≥84%, specifically 84-89%, and the wear resistance is 0 level or 1 level.

[0180] From Examples 1, Examples 16-17, and Comparative Examples 1-2, it can be seen that the composite material for 3D printing prepared by controlling the amount of nano-aluminum oxide modified by the amino silane coupling agent within a specific range has excellent comprehensive performance.

[0181] From Comparative Examples 3-4, it can be seen that the composite material for 3D printing prepared by grafting nano-aluminum oxide into the isocyanate group terminated prepolymer has excellent performance.

[0182] From the above content, it can be seen that the composite material for 3D printing prepared by designing the raw materials for the composite material for 3D printing, through the cooperation of various components, and further by grafting nano-aluminum oxide into the isocyanate group terminated prepolymer, has excellent performance.

[0183] Applicant states that the detailed process flow of the present application is illustrated by the above-mentioned examples, but the present application is not limited to the above-mentioned detailed process flow, i.e. it does not mean that the present application must rely on the above-mentioned detailed process flow to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A composite material for 3D printing, characterized in that, The preparation raw material of the composite material for 3D printing comprises the following components: an isocyanate group terminated prepolymer, amino silane coupling agent modified nano alumina and a capping agent; The preparation raw material of the amino silane coupling agent modified nano alumina comprises nano alumina and an amino silane coupling agent; The mass ratio of the nano alumina and the amino silane coupling agent is 1: (0.8-1.2) ; The D50 particle size of the nano alumina is ≤150 nm; The mass percentage of the amino silane coupling agent modified nano alumina is 3-10% based on 100% of the mass percentage of the isocyanate group terminated prepolymer; The capping agent is selected from any one or a combination of at least two of hydroxyethyl acrylate, hydroxypropyl acrylate or hydroxyethyl methacrylate.

2. The composite material for 3D printing according to claim 1, characterized in that, The preparation raw material of the isocyanate group terminated prepolymer comprises a polyol and a diisocyanate.

3. The composite material for 3D printing according to claim 2, characterized in that, The molar ratio of the hydroxyl group in the polyol and the isocyanate group in the diisocyanate is ≤0.

5.

4. The composite material for 3D printing according to claim 2, wherein, The polyol is selected from any one or a combination of at least two of polytetramethylene ether glycol, polytrimethylene ether glycol, polycaprolactone glycol, polyhexanediol adipate or polycarbonate diol.

5. The composite material for 3D printing according to claim 2, wherein, The diisocyanate is selected from any one or a combination of at least two of isophorone diisocyanate, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, m-xylylene diisocyanate, dicyclohexylmethane diisocyanate or pentamethylene pentadiisocyanate.

6. The composite material for 3D printing according to claim 2, wherein, The isocyanate group terminated prepolymer is prepared by the following method, which comprises the following steps: mixing the diisocyanate and the polyol, and reacting to obtain the isocyanate group terminated prepolymer.

7. The composite material for 3D printing according to claim 6, characterized in that, The temperature of the reaction is ≤80℃, and the reaction time is 3-5 h.

8. The composite material for 3D printing according to claim 1, wherein, The amino silane coupling agent is selected from any one or a combination of at least two of γ-aminopropyl triethoxysilane, N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl triethoxysilane, γ-aminopropyl methyl diethoxysilane or γ-aminopropyl methyl dimethoxysilane.

9. The composite material for 3D printing according to claim 8, characterized in that, The amino silane coupling agent is selected from a combination of γ-aminopropyl triethoxysilane and γ-aminopropyl methyl diethoxysilane.

10. The composite material for 3D printing according to claim 9, characterized in that, The mass ratio of the γ-aminopropyl triethoxysilane and the γ-aminopropyl methyl diethoxysilane is 1: (0.5-1.5).

11. The composite material for 3D printing according to claim 1, wherein, The amino silane coupling agent modified nano alumina is prepared by the following method, which comprises the following steps: (1) uniformly mixing the nano alumina and a solvent A, filtering, standing and performing plasma treatment; (2) mixing the plasma treated nano alumina, the amino silane coupling agent and a solvent B, and performing a modification reaction to obtain the amino silane coupling agent modified nano alumina.

12. The composite material for 3D printing according to claim 11, characterized in that, The solvent A and the solvent B are each independently selected from any one or a combination of at least two of xylene, propylene glycol methyl ether acetate or dipropylene glycol butyl ether acetate.

13. The composite material for 3D printing according to claim 11, wherein, The temperature of the modification reaction is 100-130℃, and the time is 8-15 h.

14. The composite material for 3D printing according to claim 1, wherein, The raw material for preparing the composite material for 3D printing further comprises a catalyst.

15. The composite material for 3D printing according to claim 14, characterized in that, The catalyst comprises any one of an organic tin catalyst, an organic bismuth catalyst or an organic amine catalyst, or a combination of at least two thereof.

16. The composite material for 3D printing according to claim 14, wherein, The mass percentage of the catalyst is 0.03-0.3% based on 100% of the mass percentage of the isocyanate-terminated prepolymer.

17. A method of producing a composite material for 3D printing according to any one of claims 1-16, characterized in that, The preparation method comprises the following steps: (S1) mixing the amino silane coupling agent modified nano alumina and a solvent C to obtain an amino silane coupling agent modified nano alumina solution; mixing the isocyanate-terminated prepolymer, the amino silane coupling agent modified nano alumina solution and the catalyst, and reacting to obtain an intermediate product; (S2) mixing the intermediate product and a capping agent, and performing a capping reaction to obtain the composite material for 3D printing.

18. The method of claim 17, wherein, The solvent C is selected from any one of xylene, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate or DBE, or a combination of at least two thereof.

19. The method of claim 17, wherein, The temperature of the reaction in step (S1) is 50-80°C, and the reaction time is 1-10 h.

20. The method of claim 17, wherein, The molar ratio of the hydroxyl group in the capping agent to the isocyanate group in the intermediate product in step (S2) is 1:(1-1.05).

21. The method of claim 17, wherein, The temperature of the capping reaction in step (S2) is 50-80°C, and the time is 3-8 h.

22. A 3D printing material, characterized in that The 3D printing material comprises the following components in parts by weight: The composite material according to any one of claims 1-16, 30-70 parts; The photocurable monomer, 30-70 parts; The photoinitiator, 1-3 parts.

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