Preparation and application of single-component photocuring 3D printing elastic resin with elasticity and tensile strength

Abstract

The invention discloses preparation and application of a single-component photocuring 3D printing elastic resin with elasticity and tensile strength, and the single-component photocuring 3D printing elastic resin comprises the following components by mass: 95-99% of a silicon-containing prepolymer; and 1-5% of a photoinitiator. The invention relates to the technical field of 3D printing elastic resin, and the single-component photocuring 3D printing elastic resin with excellent elasticity and tensile strength is a silicon-containing photocuring prepolymer synthesized by taking hydroxyl-terminated methylsiloxane as dihydric alcohol, and has the characteristics of low viscosity, high fluidity and high flexibility.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to the preparation and application of a single-component light-cured 3D printing elastic resin with elasticity and tensile strength. Background Art

[0002] 3D printing (3DP), also known as additive manufacturing technology, is a technology that manufactures physical parts by accumulating materials layer by layer based on three-dimensional CAD data. The historical development of 3D printing technology is a process of continuous progress and expansion. From early rapid prototyping technology to today's widespread application, 3D printing technology has been used in design and manufacturing fields such as jewelry design, footwear design and manufacturing, industrial design, architectural design, engineering design and construction, automotive design and manufacturing, as well as medical fields such as aerospace and dentistry. Among them, photosensitive resin is the main material for 3D printing. Photosensitive resin is UV resin, which is composed of polymer monomers and prepolymers. It is added with light (ultraviolet) initiator or photosensitizer. It immediately causes polymerization reaction under ultraviolet light of a certain wavelength and completes curing. Photosensitive resin is generally liquid and is used to make high-strength, high-temperature resistant, waterproof and other materials. Photosensitive resin 3D printing is commonly used in domestic mainstream SLA rapid prototyping equipment, most imported or domestic DLP desktop machines, etc.

[0003] How to provide a 3D printing elastic resin with high elasticity and sufficient tensile strength is a technical problem that the present invention urgently needs to solve. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a single-component light-cured 3D printing elastic resin with elasticity and tensile strength. The single-component light-cured 3D printing elastic resin comprises, by mass percentage: a silicon-containing prepolymer, 95-99%; a photoinitiator, 1-5%; the chemical structure of the silicon-containing prepolymer is as follows:

[0005]

[0006] Preferably, the chemical structure of R1 is as follows:

[0007]

[0008] Preferably, the chemical structure of R2 is as follows:

[0009]

[0010] Preferably, said R3=-CH3 or H.

[0011] Preferably, x≥1, y≥1, z≥1, and n=20-60.

[0012] The present invention also provides a method for preparing the single-component light-cured 3D printing elastic resin having elasticity and tensile strength, comprising the following steps:

[0013] S1. The hydroxy-terminated siloxane and isophorone diisocyanate are mixed in a molar ratio of 1:2 to 1:1.2;

[0014] S2. reacting at 60-90 degrees Celsius for 2-8 hours under the action of a catalyst;

[0015] S3. Add 5% to 15% molar amount of residual isocyanate groups of trimethylolpropane allyl ether and continue the reaction at 50-70 degrees Celsius for 12-24 hours;

[0016] S4. Add the same number of moles of hydroxyethyl methacrylate / hydroxyethyl acrylate and 0.2 to 0.5% of the total mass of the reactants as the remaining isocyanate groups;

[0017] S5. reacting at 50-70 degrees Celsius until the isocyanate group completely disappears in the infrared spectrum to obtain a silicon-containing prepolymer;

[0018] S6. Add the photoinitiator and stir evenly to obtain a single-component light-cured 3D printing elastic resin with elasticity and tensile strength.

[0019] The present invention also provides application of the single-component light-cured 3D printing elastic resin with elasticity and tensile strength in 3D printing.

[0020] The present invention also provides a 3D printing elastic resin, including a single-component light-cured 3D printing elastic resin with elasticity and tensile strength.

[0021] Preferably, the method comprises a necessary amount of 3D printing elastic resin and a carrier or auxiliary material acceptable in 3D printing.

[0022] Beneficial Effects

[0023] The present invention provides a single-component light-cured 3D printing elastic resin with elasticity and tensile strength. It has the following beneficial effects:

[0024] Low viscosity, high flexibility: The silicon-containing photocurable prepolymer synthesized with terminal hydroxymethylsiloxane as diol can have the characteristics of low viscosity, high fluidity and high flexibility;

[0025] Tensile strength and rebound: By controlling the proportion of each component, the tensile strength, elongation at break, elastic modulus and rebound resilience of the printed part can be adjusted within a certain range, so that the printed part has better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The synthetic route of the present invention is shown in FIG. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1:

[0029] 1 mol of terminal hydroxyl siloxane (n=20) was mixed with 2 mol of isophorone diisocyanate, and then 2 drops of dibutyltin dilaurate were added as a catalyst. The mixture was reacted at 80 degrees Celsius for 4 hours, and then 0.3 mol of trimethylolpropane allyl ether was added. The mixture was reacted at 50 degrees Celsius for 18 hours. Finally, 1.4 mol of hydroxyethyl methacrylate and 0.2% of the total mass of hydroquinone were added. The mixture was reacted at 50 degrees Celsius for 36 hours. The absorption peak of the isocyanate group at 2230° completely disappeared by infrared detection, confirming that the reaction was terminated, and a silicon-containing prepolymer was obtained. After 98 parts of the synthesized silicon-containing prepolymer and 2 parts of the photoinitiator were stirred evenly, a 3D printing photosensitive resin was obtained. The printed part had a tensile strength of 25MPa, an elongation at break of 105%, an elastic modulus of 34MP, and a resilience of 27%.

[0030] Embodiment 2:

[0031] 1 mol of terminal hydroxyl siloxane (n=35) was mixed with 1.6 mol of isophorone diisocyanate, and then 2 drops of dibutyltin dilaurate were added as a catalyst. The mixture was reacted at 80 degrees Celsius for 6 hours, and then 0.12 mol of trimethylolpropane allyl ether was added. The mixture was reacted at 60 degrees Celsius for 14 hours. Finally, 0.96 mol of hydroxyethyl methacrylate and 0.3% of the total mass of hydroquinone were added. The mixture was reacted at 60 degrees Celsius for 48 hours. The absorption peak of the isocyanate group at 2230° completely disappeared by infrared detection, confirming that the reaction was terminated, and a silicon-containing prepolymer was obtained. After 96 parts of the synthesized silicon-containing prepolymer and 4 parts of the photoinitiator were stirred evenly, a 3D printing photosensitive resin was obtained. The printed part had a tensile strength of 18MPa, an elongation at break of 264%, an elastic modulus of 16MP, and a resilience of 41%.

[0032] Embodiment 3:

[0033] 1 mol of terminal hydroxyl siloxane (n=55) was mixed with 1.4 mol of isophorone diisocyanate, and 4 drops of dibutyltin dilaurate were added as a catalyst. The mixture was reacted at 80 degrees Celsius for 8 hours, and then 0.08 mol of trimethylolpropane allyl ether was added. The mixture was reacted at 70 degrees Celsius for 24 hours. Finally, 0.64 mol of hydroxyethyl methacrylate and 0.5% of the total mass of hydroquinone were added. The mixture was reacted at 70 degrees Celsius for 72 hours. The absorption peak of the isocyanate group at 2230° completely disappeared by infrared detection, confirming that the reaction was terminated, and a silicon-containing prepolymer was obtained. After 97 parts of the synthesized silicon-containing prepolymer and 3 parts of the photoinitiator were stirred evenly, a 3D printing photosensitive resin was obtained. The printed part had a tensile strength of 15 MPa, an elongation at break of 314%, an elastic modulus of 9 MP, and a resilience of 63%.

[0034] In the specific implementation process, it is worth mentioning that in order to improve the strength of the elastomer, the introduction of a polymerizable allyl structure at the side end of the silicon-containing prepolymer can increase the crosslinking density of the polymer, thereby increasing the tensile strength of the final elastomer.

[0035] Synthesis principle: Single-component photocurable 3D printing elastic resin requires the resin to have low viscosity, high molecular weight and high molecular chain flexibility. Since the Si-O bond in the polymethylsiloxane structure has a long bond length and the polymethylsiloxane molecules have a small interaction force, polymethylsiloxane still has a small viscosity and a high fluidity at a large molecular weight. Therefore, the silicon-containing photocurable prepolymer synthesized with terminal hydroxymethylsiloxane as a diol can have the characteristics of low viscosity, high fluidity and high flexibility. In addition, in order to improve the strength of the elastomer, the introduction of a polymerizable allyl structure at the side end of the silicon-containing prepolymer can increase the crosslinking density of the polymer, thereby increasing the tensile strength of the final elastomer.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A single-component light-cured 3D printing elastic resin with elasticity and tensile strength, characterized by: The single-component light-cured 3D printing elastic resin comprises, by mass percentage: Silicone prepolymer, 95-99%; Photoinitiator, 1-5%; The chemical structural formula of the silicon-containing prepolymer is as follows:

2. The single-component light-cured 3D printing elastic resin with elasticity and tensile strength according to claim 1, characterized in that: The chemical structural formula of R1 is as follows:

3. The single-component light-cured 3D printing elastic resin with elasticity and tensile strength according to claim 2, characterized in that: The chemical structural formula of R2 is as follows:

4. The single-component light-cured 3D printing elastic resin with elasticity and tensile strength according to claim 3, characterized in that: Said R3=-CH3 or H.

5. The single-component light-cured 3D printing elastic resin with elasticity and tensile strength according to claim 4, characterized in that: Said x≥1, y≥1, z≥1, n=20-60.

6. The method for preparing a single-component light-cured 3D printing elastic resin having elasticity and tensile strength according to claim 5, characterized in that: The following steps are involved: S1. The hydroxy-terminated siloxane and isophorone diisocyanate are mixed in a molar ratio of 1:2 to 1:1.2; S2. reacting at 60-90 degrees Celsius for 2-8 hours under the action of a catalyst; S3. Add 5% to 15% molar amount of residual isocyanate groups of trimethylolpropane allyl ether and continue the reaction at 50-70 degrees Celsius for 12-24 hours; S4. Add the same number of moles of hydroxyethyl methacrylate / hydroxyethyl acrylate and 0.2 to 0.5% of the total mass of the reactants as the remaining isocyanate groups; S5. reacting at 50-70 degrees Celsius until the isocyanate group completely disappears in the infrared spectrum to obtain a silicon-containing prepolymer; S6. Add the photoinitiator and stir evenly to obtain a single-component light-cured 3D printing elastic resin with elasticity and tensile strength.

7. Use of the single-component light-cured 3D printing elastic resin with elasticity and tensile strength as claimed in claim 5 in 3D printing.

8. A 3D printing elastic resin, characterized in that: The single-component light-cured 3D printing elastic resin having elasticity and tensile strength as claimed in claim 5.

9. A 3D printing elastic resin according to claim 8, characterized in that: The invention comprises a necessary amount of the 3D printing elastic resin as claimed in claim 8 and a carrier or auxiliary material acceptable in 3D printing.

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