A water-washable 3D printing resin and a preparation method and application thereof

Abstract

The present application relates to a kind of washable 3D printing resin and its preparation method and application, the raw material of 3D printing resin of the present application includes: silicone resin prepolymer, polyol, isocyanate, catalyst, hydrophilic chain extender, small molecule chain extender, polymerization inhibitor, photoinitiator, 1,3-propylene glycol dimethacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, polydiquintetrabutyl glycol five acrylate.The 3D printing resin of the present application has good dispersing property, excellent hydrophilicity and mechanical property, short curing time, good solvent resistance, high temperature resistance, green environmental protection, easy to clean, and can be used in medical, aviation, artificial intelligence, building materials and other fields.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing technology, specifically relating to a washable 3D printing resin, its preparation method, and its application. Background Technology

[0002] In recent years, 3D printing curing consumables have been increasingly widely used in various fields. Among them, photocurable resin is a crucial consumable in 3D printing photocuring rapid prototyping technology. It includes oligomers, reactive diluents, photoinitiators, and additives. Selecting the appropriate oligomer is a critical step that determines the resin's viscosity, curing shrinkage rate, and mechanical properties after curing. Generally, for free radical photocurable resins, the oligomers selected are resins with carbon-carbon unsaturated double bonds. However, currently prepared resins often have insufficient or excessive crosslinking density, leading to insufficient mechanical properties after curing or defects such as high internal stress, brittleness, poor impact resistance, and poor heat resistance due to crosslinking. Therefore, it is difficult to meet the application requirements of 3D printing curing technology. For example, Chinese patent CN114874435A discloses a washable photocurable 3D printing resin and its preparation method. This patented technology improves the mechanical properties of the 3D printing resin to a certain extent, increasing its strength and toughness. However, the resin has a long curing time and low curing efficiency, resulting in low precision. Furthermore, the resin still suffers from being difficult to clean. Chinese patent CN113045715A discloses a washable, high-temperature resistant, and conductive 3D printing photocurable material and its printing process. This 3D printing photocurable material incorporates metallic fillers, nano-silica, and other substances. Although this cured material possesses excellent conductivity, and in a… While improving mechanical properties and impact resistance to a certain extent, the material has a low curing rate, and the addition of metallic fillers, nano-silica, and other substances makes it difficult to disperse the mixture evenly, leading to easy precipitation after long-term use. Therefore, it is necessary to add dispersants and anti-settling agents, which increases costs and industrialization difficulty. Chinese patent CN107284251A discloses a waterborne UV polyurethane acrylate dispersion with self-initiating function and its preparation method. The dispersion has high curing efficiency and can be deeply cured, with high hardness and good solvent resistance. However, the dispersion has poor impact resistance and high brittleness after curing, making it difficult to maintain stability for a long time.

[0003] In conclusion, current 3D printing curing materials still have a long way to go in terms of application. Therefore, developing a 3D printing curing material with good mechanical properties, high impact resistance, high stability, short curing time, good water washability, and easy cleaning will enable 3D printed products to achieve high precision and efficiency, and can be widely used in various fields. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a washable 3D printing resin, its preparation method, and its application. The washable 3D printing resin of this invention has a short curing time, significantly improving printing efficiency, accuracy, and quality. It also has good mechanical properties and stability, good water washability, is easy to clean, has a wide range of applications, and has good application prospects.

[0005] In a first aspect, the present invention provides a washable 3D printing resin, wherein the resin raw materials include: organosilicon resin prepolymer, polyol, isocyanate, catalyst, hydrophilic chain extender, small molecule chain extender, polymerization inhibitor, photoinitiator, 1,3-propanediol dimethacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, and polydipentaerythritol pentaacrylate.

[0006] Furthermore, the organosilicon resin prepolymer is prepared from vinyltrimethoxysilane, styrene ethyltrimethoxysilane, and phenylethynyltrimethylsilane.

[0007] Further, the resin comprises the following raw materials in parts by weight: 0.01-5 parts of silicone resin prepolymer, 1-20 parts of polyol, 5-10 parts of isocyanate, 0.01-2 parts of catalyst, 2-5 parts of hydrophilic chain extender, 2-5 parts of small molecule chain extender, 0.01-0.2 parts of polymerization inhibitor, 1-10 parts of photoinitiator, 5-15 parts of 1,3-propanediol dimethacrylate, 5-15 parts of neopentyl glycol diacrylate, 5-20 parts of pentaerythritol triacrylate, and 5-20 parts of polydipentaerythritol pentaacrylate.

[0008] Furthermore, the polypolyol is composed of polyoxypropylene ether diol and polyoxypropylene diol in a mass ratio of 1:(0.1-2).

[0009] Furthermore, the molecular weight of the polyoxypropylene ether diol is 400-4000D;

[0010] Furthermore, the polyoxypropylene glycol has a molecular weight of 600-1500 and a hydroxyl value of 83-208 mgKOH / g.

[0011] Further, the hydrophilic chain extender is one or a combination of 2,2-dimethylolpropionic acid, dimethylolbutyric acid, dimethylolpropionic acid, trimethylolpropane, 4-hydroxyethyloxyethyl-1-hydroxyethylphenyl diether, and 1,4-bis(2-hydroxyethoxy)benzene; the small molecule chain extender is selected from one or a combination of neopentyl glycol, ethylene glycol, 1,4-butanediol, and glycerol.

[0012] Further, the isocyanate is selected from one of dicyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate, diphenylmethane 4,4'-diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, 2,2,4-trimethylhexane diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and toluene diisocyanate;

[0013] Furthermore, the catalyst is selected from one of dibutyltin dilaurate and stannous octoate;

[0014] Furthermore, the polymerization inhibitor is selected from one or a combination of p-methoxyphenol, hydroquinone, p-hydroxyanisole, p-benzoquinone, methylhydroquinone, 2,6-di-tert-butyl-p-cresol, and resorcinol;

[0015] Furthermore, the photoinitiator is selected from one of 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)butanone, and 2-hydroxy-2-methyl-1-phenylpropanone.

[0016] Secondly, the present invention provides a method for preparing the organosilicon resin prepolymer as follows: vinyltrimethoxysilane, styreneethyltrimethoxysilane and phenylethynyltrimethylsilane are dissolved in an acidic catalyst solution, heated to carry out the reaction, cooled after the reaction is completed, separated into liquids, and the organic phase is washed to neutral. Then anhydrous magnesium sulfate is added to the organic phase for drying, filtered, and the filtrate is concentrated to obtain the organosilicon resin prepolymer.

[0017] Furthermore, the concentration of the acidic catalyst solution is 1 to 1.2% of the total mass of vinyltrimethoxysilane, styreneethyltrimethoxysilane, and phenylethynyltrimethylsilane.

[0018] Thirdly, the present invention also provides a method for preparing a washable 3D printing resin, specifically including the following steps:

[0019] S1. Add the polyol, isocyanate and catalyst to a reactor equipped with a condenser and heat to 60-90°C to react.

[0020] S2. Continue to add hydrophilic chain extender, small molecule chain extender and polymerization inhibitor to the reactor, and carry out the reaction at 60-80℃.

[0021] S3. Add organosilicon resin prepolymer, 1,3-propanediol dimethacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, polydipentaerythritol pentaacrylate, and photoinitiator to step S2 and react at 60-70°C to obtain a washable 3D printing resin.

[0022] Fourthly, the present invention also provides a washable 3D printing resin application, which includes, but is not limited to, fields such as medical, aerospace, artificial intelligence, and building materials.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The washable 3D printing resin of the present invention uses a newly synthesized organosilicon resin prepolymer. The addition of the prepolymer significantly increases the mechanical properties of the 3D printing resin, reduces the curing time of the 3D printing resin, and improves the cleanliness and stability of the 3D printed surface.

[0025] (2) The washable 3D printing resin of the present invention uses composite polyols and multiple acrylate components, which have good compatibility and high compatibility with organosilicon resin prepolymers. Without adding additives, it significantly improves the mechanical properties and impact resistance of 3D printing resin, improves the brittleness of traditional 3D printing resin, and maintains high hardness, making it widely applicable.

[0026] (3) The water-washable 3D printing resin of the present invention has a curing time of up to 4 to 8 seconds, which is fast and improves printing efficiency. The curing shrinkage rate during the printing process is as low as 1.7 to 2.3%, and the stability is high.

[0027] (4) The water-washable 3D printing resin of the present invention has a water contact angle of 92° to 138°, which has a large hydrophobic property, significantly improves the water washing performance, and can reduce the accumulation of pollutants such as dust and oil during use, and significantly reduce the degree of surface contamination. Detailed Implementation

[0028] Unless otherwise specified, the experimental methods described in the following embodiments of the present invention are generally performed under conventional conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the embodiments are commercially available products.

[0029] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0030] The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps is not limited to the steps or modules listed, but may optionally include steps not listed, or may optionally include other steps inherent to such process, method, product, or device.

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0032] The following embodiments further describe the present invention, but these embodiments are not intended to limit the scope of protection of the present invention.

[0033] Example 1: Preparation of Organosilicon Resin Prepolymer

[0034] The specific preparation steps of the organosilicon resin prepolymer in this embodiment are as follows:

[0035] At room temperature, 22.5 g of vinyltrimethoxysilane, 7.6 g of styrene ethyltrimethoxysilane, and 5.5 g of phenylethynyltrimethylsilane were slowly added dropwise to 42 mL of sulfuric acid solution (1 wt%). After the addition was complete, the temperature was raised to 55 °C and reacted for 1 h, then raised to 80 °C and reacted for 3 h. After the reaction was completed, the temperature was lowered to room temperature, allowed to stand, and separated. The organic phase was washed with water until neutral. Then, anhydrous magnesium sulfate was added to the organic phase for drying, and the solution was filtered. The filtrate was concentrated to obtain the organosilicon resin prepolymer.

[0036] In subsequent embodiments of the present invention, the silicone resin prepolymers used in the washable 3D printing resins are all silicone resin prepolymers prepared in this embodiment.

[0037] Example 2: Preparation of a washable 3D printing resin

[0038] The specific preparation steps of the washable 3D printing resin prepared in this embodiment are as follows:

[0039] S1. Add 20g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:0.5 (mass ratio)), 10g of hexamethylene diisocyanate and 0.5g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0040] S2. Add 2.2g of 2,2-dimethylolpropionic acid, 5g of ethylene glycol, and 0.2g of p-methoxyphenol to the reaction vessel, and keep the temperature at 70℃ for 4 hours.

[0041] S3. Add 0.01g of silicone resin prepolymer, 5g of 1,3-propanediol dimethacrylate, 15g of neopentyl glycol diacrylate, 15g of pentaerythritol triacrylate, 5g of polydipentaerythritol pentaacrylate, and 8g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain a washable 3D printing resin.

[0042] Example 3: Preparation of a washable 3D printing resin

[0043] The specific preparation steps of the washable 3D printing resin prepared in this embodiment are as follows:

[0044] S1. Add 12g of polypolyol (polypropylene ether glycol 2000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:0.1 (mass ratio)), 8g of hexamethylene diisocyanate and 1g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0045] S2. Continue to add 4g of 2,2-dimethylolpropionic acid, 2.5g of ethylene glycol, and 0.1g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ for 4 hours.

[0046] S3. Add 0.5g of silicone resin prepolymer, 12g of 1,3-propanediol dimethacrylate, 15g of neopentyl glycol diacrylate, 6g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 6g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain a washable 3D printing resin.

[0047] Example 4: Preparation of a washable 3D printing resin

[0048] The specific preparation steps of the washable 3D printing resin prepared in this embodiment are as follows:

[0049] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0050] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0051] S3. Add 1g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain a washable 3D printing resin.

[0052] Example 5: Preparation of a washable 3D printing resin

[0053] The specific preparation steps of the washable 3D printing resin prepared in this embodiment are as follows:

[0054] S1. Add 8g of polypolyol (polypropylene ether glycol 400D: polypropylene glycol 1500 (hydroxyl value 83mgKOH / g) = 1:2 (mass ratio)), 5g of hexamethylene diisocyanate and 0.01g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0055] S2. Continue to add 5g of 2,2-dimethylolpropionic acid, 4.5g of ethylene glycol, and 0.01g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours.

[0056] S3. Add 5g of silicone resin prepolymer, 15g of 1,3-propanediol dimethacrylate, 10g of neopentyl glycol diacrylate, 20g of pentaerythritol triacrylate, 10g of polydipentaerythritol pentaacrylate, and 3g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain a washable 3D printing resin.

[0057] Experimental Example 1: Performance Testing of Washable 3D Printing Resin

[0058] The four groups of 3D printing resins prepared in Examples 2-5 were cured in a DLP printer at 405nm to obtain four groups of standard test samples. The performance of the four groups of samples was tested, and the test indicators are as follows:

[0059] (1) Curing time: The time was recorded while the printer was used for exposure. The time required for curing was recorded when the resin began to cure. The curing time of the resin material was measured 5 times and the average value was taken.

[0060] (2) Mechanical properties: The test was conducted in accordance with GB / T 1040.3-2006 (dumbbell sample: L=115mm, r=20mm, b2=20, h=mm; tensile speed was 50mm / min). The test temperature was room temperature. The same sample was tested 5 times in different batches and the average value was taken.

[0061] (3) Impact strength: The test was conducted in accordance with GB / T 1043.1-2008 (sample size is 80mm×10mm×4mm). The test temperature was room temperature. The same sample was tested 5 times in different batches and the average value was taken.

[0062] (4) Contact angle: The water contact angle was measured using an OCA20 contact angle meter;

[0063] (5) Hardness: The hardness of the cured sample was tested using a Shore D hardness tester in accordance with GB / T531-1999. The test temperature was room temperature. The same sample was tested 5 times in different batches and the average value was taken.

[0064] (6) Curing shrinkage rate: The density ρ1 before printing and curing was determined at room temperature using the specific gravity bottle method. Specifically, a 25mL specific gravity bottle was cleaned and dried, weighed three times on a balance and the average value was taken. Then, distilled water was added to the specific gravity bottle, and the bottle was weighed three times again and the average value was taken. The distilled water was poured off and the bottle was dried. The prepared resin was added, and the bottle was weighed three times and the average value was taken. The formula for calculating ρ1 is shown in (1):

[0065]

[0066] In the formula, ρ0 is the density of distilled water (g / cm³). 3 m0 is the mass of the specific gravity bottle (g), m1 is the mass of the specific gravity bottle and distilled water (g), and m2 is the total mass of the specific gravity bottle and resin (g).

[0067] The resin system was then placed in a printer to print a 50mm×50mm×4mm model. The density ρ2 of the cured resin system was tested, and the curing shrinkage rate S was calculated using equation (2). v :

[0068]

[0069] In the formula, ρ1 is the density before curing (g / cm³). 3 ), ρ2 is the density after curing (g / cm³) 3 ).

[0070] According to the above test methods, the performance test results of the washable 3D printing resins in Examples 2 to 5 are shown in Table 1.

[0071] Table 1:

[0072]

[0073]

[0074] As shown in Table 1, the four groups of washable 3D printing resins prepared in this invention exhibit excellent mechanical properties, with tensile strength, elongation at break, and impact strength ranging from 20.52 to 28.65 MPa, 5.84 to 7.21%, and 7.28 to 11.05 KJ / m, respectively. 2 The curing time can reach 4-8 seconds, which is fast and improves printing efficiency. It has high hardness, reaching 88-92 HD. The curing shrinkage rate during printing is as low as 1.7-2.3%, indicating that the water-washable 3D printing resin of the present invention has high stability. In addition, the water contact angle is 92°-138°, which has great hydrophobicity and improves water washing performance. It can also reduce the accumulation of pollutants such as dust and oil during use, and significantly reduce the degree of surface contamination. Among them, Example 5 has the highest hydrophobicity. In summary, Example 4 has the best overall performance of the present invention.

[0075] Comparative Example 1: Preparation of 3D Printing Resin

[0076] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0077] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0078] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0079] S3. Add 1g of single-hydroxyl-terminated polydimethylsiloxane (Si-OH) (preparation method refers to Example 1 of CN109251301A), 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3h to obtain 3D printing resin.

[0080] Comparative Example 2: Preparation of 3D Printing Resin

[0081] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0082] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0083] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0084] S3. Add 6g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0085] Comparative Example 3: Preparation of 3D Printing Resin

[0086] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0087] S1. Add 18g of polypolyol (polycarbonate diol (PCDL-2000): polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0088] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0089] S3. Add 1g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0090] Comparative Example 4: Preparation of 3D Printing Resin

[0091] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0092] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:3 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0093] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0094] S3. Add 1g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0095] Comparative Example 5: Preparation of 3D Printing Resin

[0096] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0097] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:3 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0098] S2. Continue to add 6g of 2,2-dimethylolpropionic acid and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0099] S3. Add 1g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0100] Example 6 Preparation of 3D Printing Resin

[0101] The specific preparation steps of the 3D printing resin prepared in this comparative example are as follows:

[0102] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:3 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0103] S2. Continue to add 6g of ethylene glycol and 0.05g of p-methoxyphenol to the reactor, and keep the temperature at 70℃ for 4 hours.

[0104] S3. Add 1g of silicone resin prepolymer, 8g of 1,3-propanediol dimethacrylate, 5g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0105] Comparative Example 7: Preparation of 3D Printing Resin

[0106] The specific preparation steps of the washable 3D printing resin prepared in this comparative example are as follows:

[0107] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0108] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0109] S3. Add 1g of silicone resin prepolymer, 15g of 1,3-propanediol dimethacrylate, 18g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0110] Comparative Example 8: Preparation of 3D Printing Resin

[0111] The specific preparation steps of the washable 3D printing resin prepared in this comparative example are as follows:

[0112] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0113] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0114] S3. Add 1g of silicone resin prepolymer, 16g of 1,3-propanediol dimethacrylate, 15g of neopentyl glycol diacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0115] Comparative Example 9: Preparation of 3D Printing Resin

[0116] The specific preparation steps of the washable 3D printing resin prepared in this comparative example are as follows:

[0117] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0118] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0119] S3. Add 1g of silicone resin prepolymer, 13g of neopentyl glycol diacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0120] Comparative Example 10: Preparation of 3D Printing Resin

[0121] The specific preparation steps of the washable 3D printing resin prepared in this comparative example are as follows:

[0122] S1. Add 18g of polypolyol (polypropylene ether glycol 1000D: polypropylene glycol 1000 (hydroxyl value 102mgKOH / g) = 1:1.2 (mass ratio)), 6g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate to a reactor equipped with a condenser, and heat to 80℃ for 3h.

[0123] S2. Continue to add 2.8g of 2,2-dimethylolpropionic acid, 3.2g of ethylene glycol, and 0.05g of p-methoxyphenol to the reaction vessel, and control the temperature at 70℃ to react for 4 hours;

[0124] S3. Add 1g of silicone resin prepolymer, 13g of 1,3-propanediol dimethacrylate, 18g of pentaerythritol triacrylate, 20g of polydipentaerythritol pentaacrylate, and 5g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide to step S2 and react at 65°C for 3 hours to obtain 3D printing resin.

[0125] Experimental Example 2: Performance Testing of 3D Printing Resin

[0126] The 10 sets of 3D printing resins prepared in Comparative Examples 1 to 10 were cured in a DLP printer at 405nm to print 10 sets of test samples. The performance of the 10 sets of samples was tested. The test methods and indicators were the same as those in Experiment Example 1. The test results are shown in Table 2.

[0127] Table 2:

[0128]

[0129] As shown in Table 2, the washable 3D printing resin of this invention exhibits significantly better performance than the 3D printing resins prepared in Comparative Examples 1-10. Combining the data in Tables 1 and 2, it is found that the silicone resin prepolymer has a significant impact on the mechanical properties of the washable 3D printing resin. Among them, the silicone resin prepolymer synthesized in this invention significantly improves the mechanical properties of the washable 3D printing resin compared to single-hydroxyl-terminated polydimethylsiloxane (Si-OH). Furthermore, the silicone resin prepolymer synthesized in this invention has a significant effect when added within a reasonable range, without affecting the mixing performance of the mixture and thus the final resin performance. In addition, the silicone resin prepolymer synthesized in this invention effectively increases the washability of the resin, increases the contact angle, and improves hydrophobicity, thereby reducing the accumulation of dust and other pollutants in the air during the use of printed materials, and making cleaning convenient and easy.

[0130] In addition, the effects of the polyols, hydrophilic chain extenders, small molecule chain extenders, and acrylic resins of the present invention on the properties of the washable 3D printing resin are mainly mechanical properties. Among them, the effects of polyols and acrylic resins on the washable 3D printing resin of the present invention include changes in the number of double bonds in the structure, as well as the compatibility with the resin, especially the synergistic effect with the silicone resin prepolymer. In addition, the hydrophilic chain extenders and small molecule chain extenders have a certain influence on the hydrophilicity and mechanical properties of the washable 3D printing resin.

[0131] It should be noted that the specific features, structures, materials or characteristics described in this specification can be combined in any way. For the sake of brevity, not all possible combinations of the various technical features in the above embodiments have been described. Without contradiction, those skilled in the art can combine and integrate the different embodiments and features described in this specification.

[0132] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A water-washable 3D printing resin, characterized in that, The 3D printing resin comprises raw materials in the following weight parts: 0.01-5 parts of silicone resin prepolymer, 1-20 parts of polyol, 5-10 parts of isocyanate, 0.01-2 parts of catalyst, 2-5 parts of hydrophilic chain extender, 2-5 parts of small molecule chain extender, 0.01-0.2 parts of polymerization inhibitor, 1-10 parts of photoinitiator, 5-15 parts of 1,3-propanediol dimethacrylate, 5-15 parts of neopentyl glycol diacrylate, 5-20 parts of pentaerythritol triacrylate, and 5-20 parts of polydipentaerythritol pentaacrylate. The polyol is composed of polypropylene oxide ether diol and polypropylene oxide diol in a mass ratio of 1:(0.1-2); the polypropylene oxide ether diol has a molecular weight of 400 D; and the polypropylene oxide diol has a molecular weight of 1500 and a hydroxyl value of 83 mgKOH / g. The silicone resin prepolymer is prepared from vinyltrimethoxysilane, styrene ethyltrimethoxysilane and phenylacetylenyltrimethylsilane.

2. The washable 3D printing resin according to claim 1, characterized in that, The hydrophilic chain extender is one or a combination of 2,2-dimethylol propionic acid, dimethylol butyric acid, trimethylolpropane, 4-hydroxyethyl oxyethyl-1-hydroxyethyl phenyl ether and 1,4-bis(2-hydroxyethoxy)benzene; and the small molecule chain extender is one or a combination of neopentyl glycol, ethylene glycol, 1,4-butanediol and glycerol.

3. The washable 3D printing resin according to claim 1, characterized in that, the isocyanate is selected from one of dicyclohexane diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, 2,2,4-trimethylhexane diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, toluene diisocyanate; the catalyst is selected from one of dibutyl tin dilaurate, stannous octoate; the polymerization inhibitor is selected from one or a combination of p-methoxyphenol, hydroquinone, p-benzoquinone, methylhydroquinone, 2,6-di-tert-butyl-p-cresol, resorcinol; the photoinitiator is selected from one of 2-methyl-l-[4-(methylthio)phenyl]-2-(4-morpholinyl)-l-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-l-(4 methylphenyl)butanone, and 2-hydroxy-2-methyl-l-phenylpropan-l-one.

4. The washable 3D printing resin of claim 1, wherein, The preparation method of the silicone resin prepolymer comprises the following steps: dissolving vinyltrimethoxysilane, styrene ethyltrimethoxysilane and phenylacetylenyltrimethylsilane in an acidic catalyst solution, heating for reaction, cooling after completion of the reaction, separating the organic phase, washing the organic phase to neutral, drying the moisture in the organic phase, filtering, and concentrating the filtrate to obtain the silicone resin prepolymer.

5. A method of preparing the washable 3D printing resin according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1, adding polyol, isocyanate and catalyst into a reaction kettle with a condenser, and heating to 60-90℃ for reaction; S2, continuously adding hydrophilic chain extender, small molecule chain extender and polymerization inhibitor into the reaction kettle, and controlling the temperature at 60-80℃ for reaction; S3, adding silicone resin prepolymer, 1,3-propanediol dimethacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, polydipentaerythritol pentaacrylate and photoinitiator into step S2 at 60-70℃ for reaction to obtain the water-washable 3D printing resin.

6. Application of the water-washable 3D printing resin according to any one of claims 1-4 in the fields of medical treatment, aviation, artificial intelligence and building materials.

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