Photocuring 3D printing ink and application thereof

Abstract

The invention belongs to the field of ink, and particularly discloses photocuring 3D printing ink and application thereof. The 3D printing ink comprises a polymer A and a polymer B, the polymer A is a four-arm polymer containing a norbornene terminal group; the polymer B is a four-arm polymer containing double bonds in a terminal group; the four-arm polymer takes tetrahydric alcohol as a core, a support arm of the four-arm polymer contains a chain segment unit a and a chain segment unit b, and the chain segment unit a is a polylactone chain segment. According to the photocuring 3D printing ink, the polymer A and the polymer B are introduced, on one hand, the polymer B serves as a reaction type diluent to reduce the viscosity of the polymer A, dependence on a traditional small molecule diluent can be remarkably reduced, and the potential toxicity of the printing ink is greatly reduced; on the other hand, the polymer B can participate in the photo-crosslinking reaction of the ink, the crosslinking density is improved, a more compact network structure is formed in the printing process, and the fidelity rate and the mechanical property of a printed sample can be improved.

Description

Technical Field

[0001] The invention belongs to the field of ink, and in particular relates to a photocurable 3D printing ink and an application thereof. Background Art

[0002] Digital light processing (DLP) is a 3D printing technology based on the principle of photocuring. The two-dimensional cross-section of the model is projected onto the photosensitive resin through a projector, so that the resin is cured layer by layer to finally form a three-dimensional structure. The photosensitive resin that can be used for photocuring printing is the "heart" of photocuring printing. It is mainly composed of three parts: the first is the monomer, oligomer or mixture containing photocurable functional groups, which are the basis of resin curing; the second is the diluent, which is used to adjust the viscosity of the resin to make it smoother; the third is the initiator, which decomposes under light and releases free radicals or ions to accelerate the polymerization process. The ideal photosensitive resin needs to meet the requirements of physical properties, chemical properties, and mechanical properties at the same time. Specifically, it should have the following characteristics: (1) Fast curing ability: During the printing process, the light source has a limited exposure time to the resin. Therefore, the resin must be able to cure quickly, which is the key to ensuring printing efficiency; (2) Appropriate viscosity range (η<10Pa·s): If the viscosity of the resin is too high, it will slow down its flow rate, prolong the manufacturing time, and may hinder the printing of the next layer. However, too low a viscosity means that the molecular weight of the resin is not high, which may affect the quality of the finished product after curing. For resins with high viscosity, the viscosity can be adjusted appropriately by adding diluents; (3) High transparency. The resin needs to have good transparency to ensure that light can penetrate and cure each layer; (4) Appropriate curing depth. Too high a curing depth may reduce the fidelity of the printed structure; and too shallow a curing depth cannot ensure a strong adhesion between each layer after curing, which may eventually lead to the failure of printing the entire structure. In summary, these characteristics of photosensitive resins jointly determine the success and quality of photocuring 3D printing.

[0003] The photosensitive resin used in traditional digital light processing (DLP) printing mainly realizes the light curing process through the chain polymerization reaction of acrylate resin, and its resin formula widely uses acrylate small molecules as inactive diluents. However, there is a potential problem with the use of such inactive diluents: it may cause a higher shrinkage rate in the printed product, and this side effect will directly affect the accuracy and overall performance of the product. Summary of the invention

[0004] In order to overcome at least one technical problem existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a 3D printing ink.

[0005] A second object of the present invention is to provide a 3D printing product.

[0006] A third object of the present invention is to provide application of the above 3D printing ink in the field of photocuring.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a 3D printing ink, comprising a polymer A and a polymer B; the polymer A is a four-arm polymer containing a norbornene end group; the polymer B is a four-arm polymer containing a double bond in the end group; the four-arm polymer is based on a tetraol as a core, and the four-arm polymer contains a segment unit a and a segment unit b on the arm, and the segment unit a is a polylactone segment; the structural formula of the segment unit b is:

[0009] The 3D printing ink of the present invention uses a polymer A with double bonds as the main component of the ink, and uses a polymer B with a similar chemical structure and double bonds as a reactive diluent, and mixes it in an appropriate amount to construct a composite ink system. This design allows the reactive diluent polymer B to participate in the photocrosslinking reaction triggered by ultraviolet light while reducing the viscosity of the ink, forming a denser network structure, thereby effectively avoiding the adverse effects of small molecule acrylate diluents on the crosslinking rate of the ink. In addition, the 3D printing ink of the present invention can reduce the shrinkage rate of the printed product while increasing the crosslinking density, thereby improving the printing performance and biocompatibility of the printed product.

[0010] In some embodiments of the present invention, the 3D printing ink further contains a diluent.

[0011] In some embodiments of the present invention, the mass ratio of the polymer A to the diluent is (60-70):10.

[0012] In some embodiments of the present invention, the mass ratio of the polymer A to the polymer B is (2-3.5):1.

[0013] In some embodiments of the present invention, the weight average molecular weight of the polymer A is 5000-6000.

[0014] In some embodiments of the present invention, the weight average molecular weight of the polymer B is 2500-3500.

[0015] In some embodiments of the present invention, the four-arm polymer comprises the following preparation raw materials: tetraol, lactone and compound α; the structural formula of compound α is: The molar ratio of the tetraol, the lactone and the compound α is (8-12):(7-11):1.

[0016] In some embodiments of the present invention, the tetrahydric alcohol is selected from at least one of pentaerythritol and butanethritol.

[0017] In some embodiments of the present invention, the lactone is selected from at least one of caprolactone, valerolactone and enantholactone.

[0018] In some embodiments of the present invention, the polymer B is selected from at least one of a four-arm polymer containing an acrylate end group, a four-arm polymer containing a crotonate end group, and a four-arm polymer containing a pentenoate end group.

[0019] In some embodiments of the present invention, the polylactone segment is selected from at least one of a polycaprolactone segment, a polyvalerolactone segment, and a polyheptanolactone segment.

[0020] In some embodiments of the present invention, the 3D printing ink further contains an auxiliary agent; the auxiliary agent is selected from at least one of a photoinitiator, a photocrosslinker, and a light absorber.

[0021] In some embodiments of the present invention, based on the total mass percentage of polymer A, polymer B and ethyl lactate being 100%, the total mass percentage of the auxiliary agent is 8-12%.

[0022] In some embodiments of the present invention, based on the total mass percentage of polymer A, polymer B and ethyl lactate as 100%, the auxiliary agent includes the following components in mass percentage: 3.5-4.5% photoinitiator, 4.5-6.5% photocrosslinker, and 0.01-0.1% light absorber.

[0023] In some embodiments of the present invention, the photoinitiator includes at least one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) and bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide (BAPO). In some embodiments of the present invention, the photoinitiator includes diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide and bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide in a mass ratio of (2 to 10): 1.

[0024] In some embodiments of the present invention, the photocrosslinker comprises dithiothreitol.

[0025] In some embodiments of the invention, the light absorber comprises Sudan I.

[0026] In some embodiments of the present invention, the method for preparing the 3D printing ink comprises the following steps: mixing the components to obtain a 3D printing ink. In some embodiments of the present invention, the method for preparing the 3D printing ink comprises the following steps: mixing the diluent, polymer A, and polymer B, and then mixing with an auxiliary agent to obtain a 3D printing ink.

[0027] A second aspect of the present invention provides a 3D printed product, which is obtained by 3D printing using the 3D printing ink described in the first aspect of the present invention.

[0028] The third aspect of the present invention provides the application of the 3D printing ink described in the first aspect of the present invention in the field of photocuring.

[0029] The beneficial effects of the present invention are as follows: the photocurable 3D printing ink of the present invention introduces polymer A and polymer B. On the one hand, polymer B acts as a reactive diluent to reduce the viscosity of polymer A, which can significantly reduce the dependence on traditional small molecule diluents, thereby greatly reducing the potential toxicity of the printing ink; on the other hand, polymer B participates in the photocrosslinking reaction, increases the crosslinking density, and forms a denser network structure during printing, which is beneficial to improving the fidelity and mechanical properties of the printed sample. In addition, the photocurable 3D printing ink of the present invention has a lower viscosity, a higher fidelity and modulus, a lower swelling rate in DCM, excellent fidelity, excellent biocompatibility and good printability, and can be widely promoted and applied in 3D printing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 4a(PCT-CA) and 4a(PCT-DA) in the embodiments of the present invention 1 H-NMR spectrum.

[0031] Figure 2 It is the GPC elution curve diagram of 4a(PCT-CA) and 4a(PCT-DA) in the examples of the present invention.

[0032] Figure 3 IR spectra of DTT, 4a(PCT-CA), 4a(PCT-DA) and samples obtained after ink photocuring in Example 1.

[0033] Figure 4 Graph showing the change in viscosity of the ink in Examples 1 to 3 as a function of shear frequency.

[0034] Figure 5 The figure shows the design model and the actual printing picture of the ink in Example 1 during printing.

[0035] Figure 6 Graph showing the change in storage modulus and loss modulus of the inks in Examples 1 to 3 over time.

[0036] Figure 7 This is a cytotoxicity diagram of the 3D printed object of the ink in Example 1.

[0037] Figure 8This is a biological activity diagram of the 3D printed object of the ink in Example 1. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0039] The synthesis method and characterization method of the norbornene end-group-modified four-arm P (CL-co-TOSUO) and the acrylate end-group-modified four-arm P (CL-co-TOSUO) used in the examples of the present invention are as follows:

[0040] A) Synthesis of Monomer TOSUO

[0041] m-CPBA was dissolved in anhydrous dichloromethane and stirred for 30 minutes. Then, an anhydrous dichloromethane solution containing 1,4-cyclohexanedione monoethylene glycol acetal was slowly added and reacted at 40°C for 16 hours. Among them, the molar ratio of m-CPBA to 1,4-cyclohexanedione monoethylene glycol acetal was 10:1. The product was washed with sodium bisulfate solution (5% w / w), then recrystallized in anhydrous ether, and the obtained product was placed in a vacuum oven and dried to constant weight to obtain TOSUO. The synthetic route of TOSUO is as follows:

[0042]

[0043] B) Synthesis of four-arm P(CL-co-TOSUO) copolymers

[0044] 4aPCT was synthesized by bulk melt polymerization. 5 g TOSUO and 30 mL CL, 35 g initiator PE (i.e., pentaerythritol), and 10 μL catalyst Sn(Oct)2 (the molar ratio of Sn(Oct)2 to compound A was 1:1000) were added to an ampoule with a small amount of anhydrous toluene for polymerization. The polymerization reaction was carried out at 130 °C for 24 hours. The product was purified by dissolving in dichloromethane (DCM) and precipitating in anhydrous ethanol to remove unreacted monomers. The specific synthetic route of 4aPCT is as follows:

[0045]

[0046] C) Synthesis of Norbornene-Terminated Four-Arm P(CL-co-TOSUO)

[0047] Dissolve carbonic anhydride in anhydrous dichloromethane and stir for 30 minutes. Then slowly add an anhydrous dichloromethane solution containing 4aPCT, pyridine, and DMAP. The molar ratio of carbonic anhydride, pyridine, DMAP, and hydroxyl groups in 4aPCT is equal to 100:100:10:1. Wash the product with sodium bicarbonate solution (5% w / w), then precipitate in anhydrous ethanol, and the obtained product is placed in a vacuum oven and dried to constant weight to obtain 4a(PCT-CA). The specific synthetic route of 4a(PCT-CA) is as follows:

[0048]

[0049] D) Synthesis of four-arm P(CL-co-TOSUO) modified with acrylate end groups

[0050] Acryloyl chloride was dissolved in anhydrous dichloromethane and stirred for 30 minutes. Then, an anhydrous dichloromethane solution containing 4aPCT and K2CO3 powder was slowly added. The molar ratio of hydroxyl groups in acryloyl chloride, K2CO3, and 4aPCT was 10:10:1. After the reaction, the mixture was filtered and centrifuged to remove the solids, and then the filtrate was dropped into ether, and the precipitate was rotary evaporated to obtain the product 4a (PCT-DA); the specific synthesis route of 4a (PCT-DA) is as follows:

[0051]

[0052] 4aPCT, 4a(PCT-CA) and 4a(PCT-DA) were tested respectively. 1 H-NMR spectrum, as shown in Figure 1 shown. Figure 1 The H spectrum showed the characteristic absorption peak of norbornene double bond (6.19-6.37 ppm) in the four-arm (4a(PCT-CA)) copolymer; the characteristic absorption peak of acrylate end group (5.7-6.5 ppm) in the four-arm (4a(PCT-DA)) copolymer, indicating that 4a(PCT-CA) and 4a(PCT-DA) were successfully synthesized in the present invention.

[0053] The GPC elution curves of 4a(PCT-CA) and 4a(PCT-DA) were tested respectively, as shown in FIG. Figure 2 As shown. Figure 2 The measured molecular weights and molecular weight distribution indices of 4a(PCT-CA) and 4a(PCT-DA) are shown in Table 1 below.

[0054] Table 1 Molecular weight and molecular weight distribution index of 4a(PCT-CA) and 4a(PCT-DA)

[0055] Test samples <![CDATA[M n / 10 3 ]]> <![CDATA[M w / 10 3 ]]> PDI 4a(PCT-DA) 2.6 3.0 1.16 4a(PCT-CA) 5.0 5.6 1.12

[0056] Example 1

[0057] This example provides a photocurable 3D printing ink, which includes the following raw materials: a non-reactive diluent (i.e., ethyl lactate), a reactive diluent (i.e., four-arm P (CL-co-TOSUO) modified with acryloyl chloride, denoted as 4a (PCT-DA)), an ink main body (i.e., four-arm P (CL-co-TOSUO) modified with norbornene, denoted as 4a (PCT-CA)), a photocrosslinker (i.e., DL-dithiothreitol, DTT), a photoinitiator (i.e., bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, B APO), a photoinitiator (i.e., diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, TPO), and a light absorber Sudan I; wherein, the mass ratio of the non-reactive diluent, the reactive diluent, and the ink main body is 10:20:70; the total mass of the non-reactive diluent, the reactive diluent, and the ink main body is denoted as M, the mass of the photoinitiator BAPO is 0.5% of M, the mass of the photocrosslinker DTT is 6% of M, the mass of the photoinitiator TPO is 3.5% of M, and the mass of the light absorber Sudan I is 0.05% of M.

[0058] The photocurable 3D printing ink in this example is prepared by a preparation method comprising the following steps, specifically:

[0059] The non-reactive diluent, the reactive diluent and the main body of the ink were stirred and mixed at a mass ratio of 10:20:70 at 25°C, and then the corresponding amounts of photocrosslinking agents DTT, TPO, BAPO and Sudan I were added, and then stirred at a stirring speed of 500-800 r / min for 12 hours to obtain the light-curing 3D printing ink in this example.

[0060] Example 2

[0061] This example provides a photocurable 3D printing ink, which includes the following preparation raw materials: ethyl lactate, 4a(PCT-DA), 4a(PCT-CA), crosslinker DTT, photoinitiator TPO, photoinitiator BAPO, and light absorber Sudan I; wherein the mass ratio of ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) is 10:25:65; the total mass of ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) is denoted as M, the mass of photoinitiator BAPO is 0.5% of M, the mass of photocrosslinker DTT is 5.5% of M, the mass of photoinitiator TPO is 3.5% of M, and the mass of light absorber Sudan I is 0.05% of M.

[0062] The photocurable 3D printing ink in this example is prepared by a preparation method comprising the following steps, specifically:

[0063] Ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) were stirred and mixed at a mass ratio of 10:25:65 at 25°C, and then corresponding amounts of crosslinker DTT, photoinitiator TPO, photoinitiator BAPO and light absorber Sudan I were added, and stirred at a stirring speed of 500-800 r / min for 12 hours to obtain the light-curing 3D printing ink in this example.

[0064] Example 3

[0065] This example provides a photocurable 3D printing ink, which includes the following preparation raw materials: ethyl lactate, 4a(PCT-DA), 4a(PCT-CA), crosslinker DTT, photoinitiator TPO, photoinitiator BAPO, and light absorber Sudan I; wherein the mass ratio of ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) is 10:30:60; the total mass of ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) is denoted as M, the mass of photoinitiator BAPO is 0.5% of M, the mass of photocrosslinker DTT is 5.2% of M, the mass of photoinitiator TPO is 3% of M, and the mass of light absorber Sudan I is 0.05% of M.

[0066] The photocurable 3D printing ink in this example is prepared by a preparation method comprising the following steps, specifically:

[0067] Ethyl lactate, 4a(PCT-DA) and 4a(PCT-CA) were stirred and mixed at a mass ratio of 10:30:60 at 25°C, and then corresponding amounts of crosslinker DTT, photoinitiator TPO, photoinitiator BAPO and light absorber Sudan I were added, and stirred at a stirring speed of 500-800 r / min for 12 hours to obtain the light-curable 3D printing ink in this example.

[0068] Performance Test:

[0069] The Fourier transform infrared spectra (FTIR) of DTT, 4a (PCT-CA), 4a (PCT-DA), and the sample (i.e., cross-linked-PCT) obtained after irradiation with 405 nm ultraviolet light of the photocurable 3D printing ink prepared in Example 1 were tested respectively. The specific test results are as follows: Figure 3 As shown. Figure 3 It can be seen that before cross-linking, 4a (PCT-CA) was at 1652 cm -1 There is a C=C stretching vibration peak of the norbornene group at 1635 cm -1 There is a C=C stretching vibration peak of the acrylated vinyl group at 2552 cm -1After ultraviolet irradiation, the double bonds and thiol groups are consumed, and the signals of the above two peaks disappear, indicating that the reaction of norbornene and thiol groups is complete, and the disappearance of the acrylated vinyl peak indicates that the carbon-carbon double bonds are consumed to form a polymer network.

[0070] The photocurable 3D printing inks prepared in Examples 1 to 3 were subjected to rheological tests, that is, the viscosity of the inks was tested at different shear frequencies to evaluate the viscosity of the inks and the photocuring speed. The specific test results are as follows: Figure 4 Then, the inks in Examples 1 to 3 were subjected to photocuring printing, and the 3D model to be printed was converted into an STL file and sliced, with each layer having a thickness of 60 μm. The light intensity of each layer during the printing process was 35 mW / cm 2 , the illumination time is 10s, the illumination time of the first layer is 20s, and the illumination wavelength is 405nm. After printing, the obtained 3D structure is centrifuged at 3000rpm for 3min to remove the residual resin, and then irradiated with ultraviolet light for 30min to obtain a 3D printed sample. Taking the rectangular model as an example, its design size is 20cm in length and 4cm in width. The design model and the printed object are as follows Figure 5 As shown. The actual area of ​​the printed sample is measured, recorded as S1, and the design area of ​​the design model is recorded as S0, then the fidelity of the sample is S1 / S0×100%. Then the sample is subjected to DMA test to test its Young's modulus and elongation at break. The printed sample is weighed and recorded as W o , placed in dichloromethane (DCM) for 2 days, the sample was taken out and the surface solvent was quickly absorbed and weighed, recorded as W s Then the sample was dried under vacuum and weighed, recorded as W d , then the gel fraction is W d / W o × 100%, the swelling ratio in DCM is (W s -W d ) / W d .

[0071] Then the storage modulus and loss modulus of the inks in Examples 1 to 3 were tested over time. During the test, the inks were irradiated with 405 nm ultraviolet light. The results measured according to the above test method were as follows: Figure 6 As shown, the performance data of the ink measured according to the above test method are specifically shown in Table 2 below.

[0072] Table 2 Performance test results of inks in Examples 1 to 3

[0073]

[0074]

[0075] Depend on Figure 4 As shown in Table 2, the viscosity of the photocurable 3D printing inks of Examples 1 to 3 all meet the requirements of DLP printing resins, that is, the viscosity is lower than 10 Pa·s at room temperature, indicating that the mixture of ethyl lactate and 4a(PCT-DA) as a diluent can well reduce the viscosity of 4a(PCT-CA), and at different shear rates, their viscosities remain stable without significant fluctuations. Figure 5 It can be seen that the actual size of the sample printed by the ink in Example 1 is about 18 cm in length and 4 cm in width, and the fidelity of the sample is about 90%. The fidelity of the samples printed by the ink in Examples 2 to 3 is also more than 86%, indicating that the ink in the present invention has good printability and high fidelity. Figure 6 It can be seen that the photocurable 3D printing inks of Examples 1 to 3 can quickly reach a gel state within 30 seconds, showing good curing performance. It is worth noting that although the inks in Examples 1 to 3 are almost the same in viscosity, after UV curing, the ink of Example 1 shows a higher Young's modulus value than that of Examples 2 to 3, and its "self-dilution" effect is optimized. Compared with Examples 2 to 3, the sample printed by the ink prepared in Example 1 has a higher crosslinking density, the largest gel fraction, reaching 90.5%, and a higher Young's modulus, which confirms that the ink prepared in the embodiment of the present invention exhibits excellent printability and high fidelity.

[0076] The 3D printed sample prepared in Example 1 (i.e., the cross-linked-PCT in the figure) was subjected to a biosafety assessment, specifically using the CCK-8 cell proliferation-toxicity detection kit and the live / dead cell staining analysis method. The specific operation is as follows: cut a 1.0×1.0×0.4 cm square sample and place it in a 24-well plate, place it in a clean bench for ultraviolet light for 3 hours, and wash it 3 times with 75% alcohol and sterile PBS, each for 15 minutes. Under sterile conditions, add complete culture medium DMEM (extraction medium) to the well plate containing the sample, and then place the well plate in a 37°C, 5% CO2 incubator for incubation for 24 hours. After the incubation is completed, the material is taken out, the extract is filtered and sterilized with a 220μm sterile filter head, and then 890μL of the extract is taken, 100μL of serum, 10μL of double antibody are added, and an extract medium of 1% double antibody and 10% serum is prepared. 5×10 3L929 mouse fibroblasts were planted on 96-well plates at a density of cell / well, and 100 μL of extract was added respectively. Fresh culture medium was used as a control, and a well plate without cells and only PBS was added was used as the background. Culture was carried out at 37°C and 5% CO2 for 1d and 3d, and the liquid was changed every 2d. At the test time point, the corresponding plate was taken out, 10 μL of CCK-8 reagent was added to each well, and after incubation for 2h at 37°C and 5% CO2, the OD value was detected with an enzyme marker (wavelength of 450nm), and the test was repeated three times to draw the OD mean-culture time curve. And under sterile conditions, according to the instructions of the kit, the viability of each group of materials on L929 cells was detected using a live and dead cell detection kit. Live cells and dead cells were stained with green (AM) and red fluorescence (PI), respectively, and imaged with an inverted fluorescence microscope. The specific test results are as follows. Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 It can be seen that the ink in Example 1 shows a cell survival rate close to 100%, indicating that the ink in the present invention does not bring toxicity during the double cross-linking process, and the obtained PCT-based elastomer has good cell compatibility and biodegradability, showing excellent bio-friendly properties.

[0077] In summary, the photocurable 3D printing ink of the present invention introduces three components, ethyl lactate, 4a (PCT-CA) and 4a (PCT-DA). The mixture of ethyl lactate and 4a (PCT-DA) as diluents can well reduce the viscosity of 4a (PCT-CA), achieve the effect of "self-dilution", and significantly reduce the dependence on traditional small molecule diluents, thereby greatly reducing the potential toxicity of the printing ink. In addition, 4a (PCT-CA) and 4a (PCT-DA) form a denser network structure during printing, which is conducive to improving the fidelity and mechanical properties of the printed sample. In addition, the photocurable 3D printing ink of the present invention has a lower viscosity, a higher fidelity and modulus, a lower swelling rate in DCM, excellent fidelity, excellent biocompatibility and good printability, and can be widely promoted and applied in 3D printing technology.

[0078] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A 3D printing ink, characterized in that: The invention comprises polymer A and polymer B; polymer A is a four-arm polymer containing norbornene end groups; polymer B is a four-arm polymer containing double bonds in the end groups; the four-arm polymer is based on tetraol as the core, and the arms of the four-arm polymer contain segment units a and segment units b, wherein the segment unit a is a polylactone segment; the structural formula of the segment unit b is:

2. The 3D printing ink according to claim 1, characterized in that: The 3D printing ink also contains a diluent.

3. The 3D printing ink according to claim 2, characterized in that: The mass ratio of the polymer A to the diluent is (60-70):

10.

4. The 3D printing ink according to claim 1, characterized in that: The mass ratio of the polymer A to the polymer B is (2-3.5):1; and / or, the weight average molecular weight of the polymer A is 5000 to 6000; And / or, the weight average molecular weight of the polymer B is 2500-3500.

5. The 3D printing ink according to claim 1, characterized in that: The four-arm polymer comprises the following preparation raw materials: tetraol, lactone and compound A; the structural formula of compound A is: The molar ratio of the tetraol, the lactone and the compound A is (8-12):(7-11):

1.

6. The 3D printing ink according to claim 1, characterized in that: The polymer B is selected from at least one of a four-arm polymer containing an acrylate end group, a four-arm polymer containing a crotonate end group, and a four-arm polymer containing a pentenoate end group; And / or, the polylactone segment is selected from at least one of a polycaprolactone segment, a polyvalerolactone segment, and a polyheptanolactone segment.

7. The 3D printing ink according to claim 1, characterized in that: The 3D printing ink also contains an auxiliary agent; the auxiliary agent is selected from at least one of a photoinitiator, a photocrosslinker, and a light absorber.

8. The 3D printing ink according to claim 7, characterized in that: Taking the total mass percentage of polymer A, polymer B and ethyl lactate as 100%, the total mass percentage of the auxiliary agent is 8-12%.

9. A 3D printed product, characterized in that: The 3D printed product is obtained by 3D printing using the 3D printing ink described in any one of claims 1 to 8.

10. Use of the 3D printing ink according to any one of claims 1 to 8 in the field of photocuring.

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