Composite material for 3D printing and preparation method and application thereof

Abstract

The invention 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 materials of the composite material for 3D printing comprise the following components: an isocyanate-terminated prepolymer, nano aluminum oxide modified by an amino silane coupling agent and an end-capping reagent, the mass percentage content of the amino silane coupling agent modified nano aluminum oxide is 3-10% by taking the mass percentage content of the isocyanate group terminated prepolymer as 100%. The preparation method comprises the following steps: reacting an isocyanate-terminated prepolymer, an amino silane coupling agent modified nano aluminum oxide solution and a catalyst to obtain an intermediate product; and adding an end-capping reagent into the mixture, and carrying out an end-capping reaction to obtain the composite material for 3D printing. According to the preparation method, the nano aluminum oxide is grafted into the isocyanate-terminated prepolymer, so that the composite material which is excellent in performance and is used for 3D printing is prepared.

Description

Technical Field

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

[0002] 3D printing technology, also known as additive manufacturing technology, is actually an emerging technology in the field of rapid prototyping. It is a technology based on digital model files, using powdered metal or plastic and other bondable materials to construct objects by printing layer by layer. The basic principle is layered manufacturing, which is a technology that adds materials layer by layer to generate three-dimensional entities. At present, 3D printing technology is mainly used in product prototypes, mold manufacturing, art creation, jewelry making and other fields, replacing these traditional fine processing processes. In addition, 3D printing technology has gradually been applied to medicine, bioengineering, architecture, clothing, aviation, batteries, optical sensors and other fields, opening up a broad space for innovation.

[0003] With the rapid development of electronic technology, 3D printing technology has gradually been applied to the fields of temporary protection of batteries and white surface protection of optical sensors. This requires 3D printing materials to have higher hardness, higher light transmittance, lower haze and better wear resistance. However, the 3D printing materials provided by existing technologies have poor hardness, light transmittance and wear resistance.

[0004] Therefore, how to provide a 3D printing material with higher hardness, higher light transmittance, lower haze and better wear resistance has become a technical problem that needs to be solved urgently. Summary of the invention

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

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a composite material for 3D printing, wherein the raw materials for preparing the composite material for 3D printing include the following components:

[0008] Isocyanate-terminated prepolymer, aminosilane coupling agent-modified nano-alumina and a capping agent;

[0009] Taking the mass percentage of the isocyanate-terminated prepolymer as 100%, the mass percentage of the aminosilane coupling agent-modified nano-aluminum oxide is 3-10%;

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

[0011] The present invention designs the raw materials for preparing the composite material for 3D printing, and further uses an isocyanate-terminated prepolymer and an aminosilane coupling agent-modified nano-alumina to graft the nano-alumina into the isocyanate-terminated prepolymer, so that the 3D printing material prepared by the 3D printing composite material provided by the present invention has good stability, and effectively avoids the occurrence of sedimentation and nozzle clogging of the 3D printing material under long-term continuous 3D printing. The present invention introduces unsaturated bonds in the composite material for 3D printing by using a capping agent, so that it can be used for 3D printing.

[0012] The present invention designs the raw materials for preparing the composite material for 3D printing, and prepares the composite material for 3D printing with high hardness, high light transmittance, low haze and good wear resistance through the coordination of various components.

[0013] Furthermore, the present invention controls the amount of aminosilane coupling agent-modified nano-alumina in the composite material for 3D printing within a specific range, thereby preparing a composite material for 3D printing with excellent comprehensive performance. If the amount of aminosilane coupling agent-modified nano-alumina is too small, the hardness and wear resistance of the prepared composite material for 3D printing are poor; if the amount of aminosilane coupling agent-modified nano-alumina is too large, the hardness of the prepared composite material for 3D printing is too high, and the material may crack during the subsequent 3D printing process.

[0014] The composite material for 3D printing provided by the present invention can be used to prepare 3D printing materials, and can be used for temporary protection of electronic components, surface protection of optical sensors, etc. 3D printing allows it to have more customized applications.

[0015] Taking the mass percentage of the isocyanate-terminated prepolymer as 100%, the mass percentage of the aminosilane coupling agent-modified nano-alumina is 3-10%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] As a preferred technical solution of the present invention, the raw materials for preparing the isocyanate-terminated prepolymer include polyol and 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 may 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 of polytetramethylene ether glycol (including but not limited to: PTMEG650), polytrimethylene ether glycol (including but not limited to: PO3G1000), polycaprolactone diol (including but not limited to: PCL1000), polyhexanediol adipate or polycarbonate diol, or a combination of at least two thereof.

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

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

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

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

[0025] The diisocyanate and the polyol are mixed and reacted to obtain an isocyanate-terminated prepolymer;

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

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

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

[0029] Preferably, the reaction further includes a post-treatment step, and the post-treatment method includes cooling to 35-45°C, for example, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C or 45°C, etc.

[0030] As a preferred technical solution of the present invention, the raw materials for preparing the aminosilane coupling agent-modified nano-alumina include nano-alumina and an aminosilane coupling agent.

[0031] Preferably, the mass ratio of the nano-alumina to the aminosilane 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-aluminum oxide is ≤150 nm, for example, it may be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or 150 nm.

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

[0034] The present invention prepares a 3D printing composite material with excellent comprehensive performance by controlling the D50 particle size of nano-alumina within a specific range.

[0035] Preferably, the aminosilane coupling agent is selected from any one of γ-aminopropyltriethoxysilane (KH550), N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (KH572), 3-aminopropyltrimethoxysilane (APS), N-(β-aminoethyl)-γ-aminopropyltriethoxysilane (KH791), γ-aminopropylmethyldiethoxysilane or γ-aminopropylmethyldimethoxysilane, or a combination of at least two thereof.

[0036] Preferably, the aminosilane coupling agent is selected from a combination of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane.

[0037] Preferably, the mass ratio of γ-aminopropyltriethoxysilane to γ-aminopropylmethyldiethoxysilane 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 invention, by selecting a combination of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane as an aminosilane coupling agent for modifying nano-alumina, and controlling the mass ratio of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane within a specific range, the comprehensive performance of the composite material used for 3D printing is further improved.

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

[0040] (1) After the nano-alumina and solvent A are uniformly mixed, the mixture is filtered, allowed to stand, and then subjected to plasma treatment;

[0041] (2) Mixing the plasma-treated nano-alumina, an aminosilane coupling agent, and a solvent B to carry out a modification reaction to obtain the aminosilane coupling agent-modified nano-alumina.

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

[0043] Preferably, the mass ratio of the nano-alumina to 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 to 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 plasma treatment method comprises using a plasma treatment machine for treatment.

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

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

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

[0049] Preferably, the plasma treatment time 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.

[0050] Preferably, the temperature of the modification reaction is 100-130°C (for example, it can be 100°C, 105°C, 110°C, 115°C, 120°C, 125°C or 130°C, 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 includes a post-treatment step, and the post-treatment method includes: filtering, washing, and drying.

[0052] As a preferred technical solution of the present invention, the raw materials for preparing the composite material for 3D printing also include a catalyst;

[0053] Preferably, 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, and more preferably dibutyltin dilaurate and / or stannous octoate.

[0054] Preferably, based on the mass percentage of the isocyanate-terminated prepolymer as 100%, the mass percentage of the catalyst is 0.03-0.3%, for example, it 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 invention provides a method for preparing a composite material for 3D printing as described in the first aspect, the preparation method comprising the following steps:

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

[0057] The isocyanate-terminated prepolymer, the aminosilane coupling agent-modified nano-alumina solution, and the catalyst are mixed and reacted to obtain an intermediate product;

[0058] (S2) mixing the intermediate product and the capping agent, performing a capping reaction, and obtaining the composite material for 3D printing.

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

[0060] It should be noted that the present invention 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 reaction temperature in step (S1) is 50-80°C (for example, it 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, it 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 blocking agent in step (S2) to the isocyanate group in the intermediate product is 1:(1-1.05), for example, it 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°C (for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, etc.), and the time is 3-8h (for example, it can be 3h, 4h, 5h, 6h, 7h or 8h, etc.).

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

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

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

[0067] In the present invention, the solvent C is removed by vacuum rotary evaporation, and the mass percentage of the solvent C in the composite material for 3D printing is controlled to be ≤0.5%, thereby avoiding 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 invention provides a 3D printing material, wherein the 3D printing material comprises the following components in parts by weight:

[0069] 30-70 parts of the composite material as described in the first aspect;

[0070] 30-70 parts of photocurable monomer;

[0071] 1-3 parts of photoinitiator.

[0072] The composite material provided by the present invention is used to prepare 3D printing materials. The prepared 3D printing materials have good stability, and effectively avoid the occurrence of sedimentation and nozzle clogging of the 3D printing materials under long-term continuous 3D printing conditions.

[0073] In the present invention, the weight proportion of the composite material described in the first aspect in the 3D printing material may be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts, etc.

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

[0075] The weight proportion 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 invention, the photocurable monomer includes acrylic monomer and / or acrylate monomer.

[0077] It should be noted that the present invention does not have any special restrictions on the specific selection of acrylic acid monomers and acrylic acid ester monomers, and acrylic acid monomers and acrylic acid ester monomers commonly used in the art are applicable. The acrylic acid monomers exemplarily include but are not limited to: acrylic acid, methacrylic acid, etc.; the acrylic acid ester monomers exemplarily include but are not limited to: glycidyl methacrylate, 3-ethyl-3-epoxypropyl methyl acrylate, trimethylolpropane formal acrylate, tetrahydrofuran acrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, tripropylene glycol diacrylate, 1,6-ethylene glycol diacrylate, tricyclodecane dimethanol diacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, triallyl isocyanurate, etc.

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

[0079] It should be noted that the present invention does not have any special restrictions on the specific selection of free radical photoinitiators and cationic photoinitiators, and the free radical photoinitiators and cationic photoinitiators commonly used in the art are 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 phosphonic 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 invention has the following beneficial effects:

[0081] (1) The present invention designs the raw materials for preparing the composite material for 3D printing, and grafts nano-alumina into the isocyanate-terminated prepolymer to prepare a composite material for 3D printing with excellent performance.

[0082] (2) The present invention can further control the D50 particle size of nano-alumina within a specific range, select a combination of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane as an aminosilane coupling agent for modifying nano-alumina, and control the mass ratio of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane within a specific range, thereby further improving the comprehensive performance of the composite material used for 3D printing. DETAILED DESCRIPTION

[0083] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

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

[0085] Table 1

[0086]

[0087] Preparation Example A

[0088] This preparation example provides an isocyanate-terminated prepolymer 1 and a preparation method thereof. The preparation method of the isocyanate-terminated prepolymer 1 is as follows:

[0089] After drying polytetramethylene ether glycol at 50° C. for 10 h, isophorone diisocyanate and polytetramethylene ether glycol are mixed, the temperature is controlled at 70° C., the mixture is reacted for 4 h, and then the mixture is cooled to 40° C. to obtain an isocyanate-terminated prepolymer 1;

[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] This preparation example provides an isocyanate-terminated prepolymer 2 and a preparation method thereof. The preparation method of the isocyanate-terminated prepolymer 2 is as follows:

[0093] After drying polytrimethylene ether glycol at 60° C. for 8 h, hexamethylene diisocyanate and polytrimethylene ether glycol were mixed, the temperature was controlled at 75° C., the reaction was carried out for 4 h, and then the temperature was cooled to 40° C. to obtain an isocyanate-terminated prepolymer 2;

[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] This preparation example provides an isocyanate-terminated prepolymer 3 and a preparation method thereof. The preparation method of the isocyanate-terminated prepolymer 3 is as follows:

[0097] After the polycaprolactone diol was dried at 50°C for 11 hours, di-m-xylylene diisocyanate and the polycaprolactone diol were mixed, the temperature was controlled at 80°C, the reaction was carried out for 4 hours, and then the temperature was cooled to 40°C to obtain an isocyanate-terminated prepolymer 3;

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

[0099] Preparation Example 1

[0100] This preparation example provides a nano-alumina 1 modified by an aminosilane coupling agent and a preparation method thereof. The preparation method of the nano-alumina 1 modified by an aminosilane coupling agent is as follows:

[0101] (1) After mixing nano-alumina 2 (10 g) and xylene (90 g) evenly, the mixture was filtered, allowed to stand, and then subjected to plasma treatment using a plasma treatment machine. The plasma treatment power was set to 80 W, nitrogen was passed, the flow rate was 300 mL / min, and the time was 120 seconds;

[0102] (2) Then, the plasma-treated nano-alumina 2, γ-aminopropyltriethoxysilane (5 g), γ-aminopropylmethyldiethoxysilane (5 g), and xylene (3 g) are mixed, and after a modification reaction at 110° C. for 8 hours, the mixture is filtered, washed, and dried to obtain the aminosilane coupling agent-modified nano-alumina 2.

[0103] Preparation Example 2

[0104] This preparation example provides a nano-alumina 2 modified by an aminosilane coupling agent and a preparation method thereof. The preparation method of the nano-alumina 2 modified by an aminosilane coupling agent is as follows:

[0105] (1) After mixing nano-alumina 2 (10 g) and xylene (90 g) evenly, the mixture was filtered, allowed to stand, and subjected to plasma treatment using a plasma treatment machine. The plasma treatment power was set to 70 W, nitrogen was passed, the flow rate was 500 mL / min, and the time was 80 seconds;

[0106] (2) Then, the plasma-treated nano-alumina 2, γ-aminopropyltriethoxysilane (4 g), γ-aminopropylmethyldiethoxysilane (4.5 g), and xylene (3 g) are mixed, and after a modification reaction at 110° C. for 8 h, the mixture is filtered, washed, and dried to obtain the aminosilane coupling agent-modified nano-alumina 2.

[0107] Preparation Example 3

[0108] This preparation example provides a nano-alumina 3 modified by an aminosilane coupling agent and a preparation method thereof. The preparation method of the nano-alumina 3 modified by an aminosilane coupling agent is as follows:

[0109] (1) After mixing nano-alumina 2 (10 g) and propylene glycol methyl ether acetate (90 g) uniformly, the mixture was filtered, allowed to stand, and subjected to plasma treatment using a plasma treatment machine, with the plasma treatment power set to 100 W, nitrogen gas flow rate set to 400 mL / min, and the time set to 150 seconds;

[0110] (2) Then, the plasma-treated nano-alumina 2, γ-aminopropyltriethoxysilane (6.5 g), γ-aminopropylmethyldiethoxysilane (6.5 g), and propylene glycol methyl ether acetate (3 g) are mixed, and after a modification reaction at 110° C. for 8 h, the mixture is filtered, washed, and dried to obtain the aminosilane coupling agent-modified nano-alumina 3.

[0111] Preparation Example 4-7

[0112] Preparation Example 4-7 provides a kind of aminosilane coupling agent modified nano-alumina 4-7 and its preparation method in turn, which is different from Preparation Example 1 only in that:

[0113] Preparation Example 4: Replace the nano-alumina 2 with the nano-alumina 3 of the same mass, and finally prepare the aminosilane coupling agent-modified nano-alumina 4;

[0114] Preparation Example 5: Replace the nano-alumina 2 with the nano-alumina 1 of the same mass, and finally prepare the aminosilane coupling agent-modified nano-alumina 5;

[0115] Preparation Example 6: Replace the nano-alumina 2 with the nano-alumina 4 of the same mass, and finally prepare the aminosilane coupling agent-modified nano-alumina 6;

[0116] Preparation Example 7: Replace the nano-alumina 2 with the nano-alumina 5 of the same mass, and finally prepare the aminosilane coupling agent-modified nano-alumina 7;

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

[0118] Preparation Example 8-11

[0119] Preparation Example 8-11 provides a kind of aminosilane coupling agent modified nano-alumina 8-11 and its preparation method, which is different from Preparation Example 1 only in that:

[0120] Preparation Example 8: The mass of γ-aminopropyltriethoxysilane is 6.6 g, and the mass of γ-aminopropylmethyldiethoxysilane is 3.4 g, and finally, aminosilane coupling agent-modified nano-alumina 8 is prepared;

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

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

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

[0124] The other conditions were the same as those in Preparation Example 1.

[0125] Preparation Examples 12-15

[0126] Preparation Examples 12-15 provide one type of aminosilane coupling agent-modified nano-alumina 12-15 and a preparation method thereof, which differs from Preparation Example 1 only in that:

[0127] Preparation Example 12: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) were replaced with γ-aminopropyltriethoxysilane (5 g) and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (5 g), and finally the aminosilane coupling agent-modified nano-alumina 12 was prepared;

[0128] Preparation Example 13: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) were replaced with γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldimethoxysilane (5 g), and finally aminosilane coupling agent-modified nano-alumina 13 was prepared;

[0129] Preparation Example 14: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) were replaced with γ-aminopropyltriethoxysilane (10 g), and finally aminosilane coupling agent-modified nano-alumina 14 was prepared;

[0130] Preparation Example 15: γ-aminopropyltriethoxysilane (5 g) and γ-aminopropylmethyldiethoxysilane (5 g) were replaced with γ-aminopropylmethyldiethoxysilane (10 g), and finally aminosilane coupling agent-modified nano-alumina 15 was prepared;

[0131] The other conditions were the same as those in Preparation Example 1.

[0132] Example 1

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

[0134] (S1) mixing the aminosilane coupling agent-modified nano-alumina 1 (7 g) and xylene (100 g) to obtain an aminosilane coupling agent-modified nano-alumina solution;

[0135] The isocyanate-terminated prepolymer 1 (100 g), the aminosilane coupling agent-modified nano-alumina solution, and dibutyltin dilaurate (0.1 g) were mixed and reacted at 70° C. for 6 h to obtain an intermediate product;

[0136] (S2) mixing the intermediate product and hydroxyethyl acrylate, performing a capping reaction at 70° C. for 6 hours, and then performing a reduced pressure rotary evaporation at 70° C. to obtain a composite material for 3D printing having a xylene content of ≤0.5% by weight;

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

[0138] Example 2

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

[0140] (S1) mixing the aminosilane coupling agent-modified nano-alumina 1 (5 g) and xylene (80 g) to obtain an aminosilane coupling agent-modified nano-alumina solution;

[0141] The isocyanate-terminated prepolymer 2 (100 g), the aminosilane coupling agent-modified nano-alumina solution, and dibutyltin dilaurate (0.3 g) were mixed and reacted at 70° C. for 5 h to obtain an intermediate product;

[0142] (S2) mixing the intermediate product and hydroxypropyl acrylate, performing a capping reaction at 70° C. for 7 h, and then performing a reduced pressure rotary evaporation at 75° C. to obtain a composite material for 3D printing having a xylene content of ≤0.5% by mass;

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

[0144] Example 3

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

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

[0147] The isocyanate-terminated prepolymer 3 (100 g), the aminosilane coupling agent-modified nano-alumina solution, and dibutyltin dilaurate (0.2 g) were mixed and reacted at 60° C. for 8 h to obtain an intermediate product;

[0148] (S2) mixing the intermediate product and hydroxyethyl acrylate, performing an end-capping reaction at 50° C. for 8 hours, and then performing a reduced pressure rotary evaporation at 70° C. to obtain a composite material for 3D printing having a xylene content of ≤0.5% by mass;

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

[0150] Embodiment 4-15

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

[0152] In Example 4-15, the aminosilane coupling agent-modified nano-alumina 1 provided in Preparation Example 1 used in Example 1 is replaced with the aminosilane coupling agent-modified nano-alumina 4-15 provided in Preparation Example 4-15 in sequence;

[0153] Other conditions are the same as in Example 1.

[0154] Examples 16-17, 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 differ from Example 1 only in that:

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

[0157] Example 17: In step (S1), the mass of the nano-alumina 1 modified with the aminosilane coupling agent is 10 g;

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

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

[0160] Other conditions are the same as in Example 1.

[0161] Comparative Example 3

[0162] This comparative example provides a composite material for 3D printing and a preparation method thereof. The preparation method of the composite material for 3D printing is as follows:

[0163] (S2) mixing the isocyanate-terminated prepolymer 1 (100 g) and hydroxyethyl acrylate, and performing a blocking reaction at 60° C. for 3 h to obtain an intermediate product;

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

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

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

[0167] Comparative Example 4

[0168] This comparative example provides a 3D printing material, which is purchased from Hangzhou Leyi with a brand name of LY8002.

[0169] The composite materials for 3D printing provided in the above Examples 1-17 and Comparative Examples 1-3 (50 parts by weight) were respectively mixed with glycidyl methacrylate (50 parts by weight) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (2 parts by weight) to obtain a 3D printing material;

[0170] Use SLA-3D printer to print membrane materials with the dimensions of 0.1m×0.1m×60μm, and conduct the following performance tests:

[0171] (1) Hardness: GB / T 6739-2022 Paints and varnishes - Determination of film hardness by pencil method. A 500g load is used to test the pencil hardness. During the test, a transparent glass plate is placed at the bottom, and then the film to be tested is laid flat on the glass plate to test its pencil hardness.

[0172] (2) Haze: Use a Biagra TH-110 haze meter and scan the readings directly after calibrating the blank.

[0173] (3) Transmittance: Use a Biagra TH-110 haze meter and scan and read directly after calibrating the blank.

[0174] (4) Abrasion resistance: Referring to ASTM F2357-04, the test was conducted using an RCA paper tape machine with a load of 175 g and a speed of 10 turns / min. The results after 100 turns were as follows: scratches from level 0 to level 4 were ranked in order of severity, with level 0 indicating no scratches and level 4 indicating severe damage.

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

[0176] Table 2

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

[0178] It can be seen from the above performance data that the present invention designs the raw materials for preparing the composite material for 3D printing, and through the coordination of each component, further grafts nano-alumina into the isocyanate-terminated prepolymer to prepare a composite material for 3D printing with excellent performance, the hardness of which is 2H or 3H, the haze is ≤4.4%, specifically 1.1-4.4%, the transmittance is ≥84%, specifically 84-89%, and the wear resistance is level 0 or level 1.

[0179] It can be seen from Examples 1-15 that the present invention can further control the D50 particle size of nano-alumina within a specific range, and select a combination of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane as an aminosilane coupling agent for modifying nano-alumina, and control the mass ratio of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane within a specific range, thereby further improving the comprehensive performance of the composite material for 3D printing, and the hardness is 2H or 3H, the haze is ≤3.0%, specifically 1.1-3.0%, the transmittance is ≥84%, specifically 84-89%, and the wear resistance is level 0 or level 1.

[0180] It can be seen from Example 1, Examples 16-17, and Comparative Examples 1-2 that the present invention prepares a composite material for 3D printing with excellent comprehensive performance by controlling the amount of nano-alumina modified by an aminosilane coupling agent in the composite material for 3D printing within a specific range.

[0181] It can be seen from Comparative Examples 3-4 that the present invention prepares a composite material for 3D printing with excellent performance by grafting nano-alumina into an isocyanate-terminated prepolymer.

[0182] From the above content, it can be seen that the present invention designs the raw materials for preparing the composite material for 3D printing, through the coordination of various components, and further by grafting nano-alumina into the isocyanate-terminated prepolymer, to prepare a composite material for 3D printing with excellent performance.

[0183] The applicant declares that the present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A composite material for 3D printing, characterized in that: The raw materials for preparing the composite material for 3D printing include the following components: Isocyanate-terminated prepolymer, aminosilane coupling agent-modified nano-alumina and a capping agent; Taking the mass percentage of the isocyanate-terminated prepolymer as 100%, the mass percentage of the aminosilane coupling agent-modified nano-aluminum oxide is 3-10%; The end-capping agent is selected from any one of hydroxyethyl acrylate, hydroxypropyl acrylate or hydroxyethyl methacrylate, or a combination of at least two thereof.

2. The composite material for 3D printing according to claim 1, characterized in that: The raw materials for preparing the isocyanate-terminated prepolymer include polyol and diisocyanate; Preferably, the molar ratio of the hydroxyl group in the polyol to the isocyanate group in the diisocyanate is ≤0.5; Preferably, the polyol is selected from any one or a combination of at least two of polytetramethylene ether glycol, polytrimethylene ether glycol, polycaprolactone diol, polyhexanediol adipate or polycarbonate diol; Preferably, the diisocyanate is selected from any one or a combination of at least two of isophorone diisocyanate, hexamethylene diisocyanate, tetramethylxylylene diisocyanate, metaxylylene diisocyanate, dicyclohexylmethane diisocyanate or pentamethylene pentamethylene diisocyanate.

3. The composite material for 3D printing according to claim 2, characterized in that: The isocyanate-terminated prepolymer is prepared by the following method, which comprises the following steps: The diisocyanate and the polyol are mixed and reacted to obtain an isocyanate-terminated prepolymer; Preferably, the reaction temperature is ≤80°C and the reaction time is 3-5h.

4. The composite material for 3D printing according to claim 1, characterized in that: The raw materials for preparing the aminosilane coupling agent-modified nano-alumina include nano-alumina and aminosilane coupling agent; Preferably, the mass ratio of the nano-alumina to the aminosilane coupling agent is 1:(0.8-1.2); Preferably, the D50 particle size of the nano-alumina is ≤150nm; Preferably, the aminosilane coupling agent is selected from any one of γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane or γ-aminopropylmethyldimethoxysilane, or a combination of at least two thereof.

5. The composite material for 3D printing according to claim 4, characterized in that: The aminosilane coupling agent is selected from the combination of γ-aminopropyltriethoxysilane and γ-aminopropylmethyldiethoxysilane; Preferably, the mass ratio of the γ-aminopropyltriethoxysilane to the γ-aminopropylmethyldiethoxysilane is 1:(0.5-1.5).

6. The composite material for 3D printing according to claim 4, characterized in that: The aminosilane coupling agent-modified nano-alumina is prepared by the following method, which comprises the following steps: (1) After the nano-alumina and solvent A are uniformly mixed, the mixture is filtered, allowed to stand, and then subjected to plasma treatment; (2) mixing the plasma-treated nano-alumina, an aminosilane coupling agent, and a solvent B to carry out a modification reaction to obtain the aminosilane coupling agent-modified nano-alumina; Preferably, the solvent A and the solvent B are 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; Preferably, the modification reaction is carried out at a temperature of 100-130° C. and for a time of 8-15 h.

7. The composite material for 3D printing according to claim 1, characterized in that: The raw materials for preparing the composite material for 3D printing also include a catalyst; Preferably, the catalyst comprises any one or a combination of at least two of an organic tin catalyst, an organic bismuth catalyst or an organic amine catalyst; Preferably, based on 100% by mass of the isocyanate-terminated prepolymer, the mass percentage of the catalyst is 0.03-0.3%.

8. A method for preparing a composite material for 3D printing according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (S1) mixing the aminosilane coupling agent-modified nano-alumina with solvent C to obtain an aminosilane coupling agent-modified nano-alumina solution; The isocyanate-terminated prepolymer, the aminosilane coupling agent-modified nano-alumina solution, and the catalyst are mixed and reacted to obtain an intermediate product; (S2) mixing the intermediate product and the capping agent, performing a capping reaction, and obtaining the composite material for 3D printing.

9. The preparation method according to claim 8, characterized in that: The solvent C is selected from any one of xylene, propylene glycol methyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate or DBE, or a combination of at least two thereof; Preferably, the reaction temperature in step (S1) is 50-80°C, and the reaction time is 1-10h; Preferably, the molar ratio of the hydroxyl group in the blocking agent in step (S2) to the isocyanate group in the intermediate product is 1:(1-1.05); Preferably, the temperature of the end-capping reaction in step (S2) is 50-80°C and the time is 3-8h.

10. A 3D printing material, characterized in that: The 3D printing material includes the following components in parts by weight: 30-70 parts of the composite material according to any one of claims 1 to 6; 30-70 parts of photocurable monomer; 1-3 parts of photoinitiator.

Images