High-toughness low-shrinkage photosensitive resin for photocuring 3D printing and preparation method and application thereof

Abstract

The invention provides a high-toughness low-shrinkage photosensitive resin for photocuring 3D printing and a preparation method and application thereof. The high-toughness low-shrinkage photosensitive resin for photocuring 3D printing is prepared from the following raw material components: urethane acrylate, a reactive diluent, an additive and a photoinitiator. The proportion of each raw material component is as follows in parts by mass: 10-35 parts of polyurethane acrylate; 50 to 80 parts of a reactive diluent; 5-30 parts of an additive; and 1-5 parts of a photoinitiator. The photosensitive resin is a photosensitive resin system which is high in toughness, low in shrinkage and easy to decompose, so that the defects of deformation, warping, layering, cracks and the like caused in the printing and degreasing processes are eliminated, and a defect-free ceramic product is obtained.

Description

Technical Field

[0001] This invention belongs to the field of photopolymer 3D printing ceramic technology, specifically relating to a high-toughness, low-shrinkage photosensitive resin for photopolymer 3D printing, its preparation method, and its uses. Background Technology

[0002] Currently, most photosensitive resins used in stereolithography for preparing ceramic materials are acrylic resins. Because acrylic resins shrink during curing, they easily generate interlayer stress during layer-by-layer printing, leading to defects such as deformation, warping, and delamination of the green body. Subsequently, during debinding, the resin's unidirectional decomposition behavior and limited diffusion of decomposition products generate thermal stress within the green body, resulting in defects such as cracks, ultimately significantly affecting the material's performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, its preparation method, and its applications, which can effectively solve the above-mentioned problems.

[0004] The technical solution adopted in the present invention is as follows:

[0005] The first objective of this invention is to provide a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, comprising the following raw material components: polyurethane acrylate, reactive diluent, additives, and photoinitiator.

[0006] Preferably, the proportions of each raw material component are as follows: by mass parts, 10-35 parts of polyurethane acrylate; 50-80 parts of reactive diluent; 5-30 parts of additives; and 1-5 parts of photoinitiator.

[0007] Preferably, the polyurethane acrylate is selected from either aliphatic polyurethane acrylate or aromatic polyurethane acrylate.

[0008] Preferably, the reactive diluent is selected from one or a mixture of several acrylate and vinyl reactive diluents;

[0009] The acrylates include isobornyl acrylate (IOBA), octadecyl acrylate (ODA), hydroxyethyl acrylate (HEA), 2-phenoxyethyl acrylate (PHEA), neopentyl glycol diacrylate (NPG2PODA), methyl methacrylate (MMA), 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), dipropylene glycol diacrylate (DPGDA), polyethylene glycol diacrylates (PEG200DA, PEG400DA, or PEG600DA), trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate (PETA), and ethoxylated trimethylolpropane triacrylate (ETPTA).

[0010] Preferably, the additive is a polymeric auxiliary agent that has plasticizing and toughening effects and low-temperature decomposition behavior;

[0011] The polymeric additives include polyvinyl alcohol, polyethylene glycol, aliphatic diesters, phthalates, polyphenolic esters, benzoates, polyol esters, chlorinated hydrocarbons, epoxy compounds, citrates, and polyesters; wherein, phthalates include phthalates and terephthalates.

[0012] Preferably, the photoinitiator is one or a mixture of several of 819, 184, 369, and TPO.

[0013] Preferably, the high-toughness, low-shrinkage photosensitive resin used for photopolymerization 3D printing has an elongation at break >90% and a shrinkage rate <4%.

[0014] The second objective of this invention is to provide a method for preparing a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, comprising the following steps:

[0015] Step 1: Weigh the polyurethane acrylate, reactive diluent and photoinitiator according to the formula, and mechanically stir them at room temperature at a stirring rate of 300-500 r / min for 30-60 minutes to ensure that the components are mixed evenly.

[0016] Step 2: Add the additive in the mass ratio to the well-mixed mixture from Step 1, and mechanically stir at room temperature at a stirring rate of 300-500 r / min for 30-60 minutes to finally obtain a photosensitive resin with high toughness and low shrinkage properties.

[0017] The third objective of this invention is to provide a use of a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing is used for photopolymerization 3D printing, especially for stereolithography, digital light processing, or continuous liquid interface printing.

[0018] The fourth objective of this invention is to provide a use of a high-toughness, low-shrinkage photosensitive resin for photocurable 3D printing. The high-toughness, low-shrinkage photosensitive resin for photocurable 3D printing is used for photocurable 3D printing ceramic materials, wherein the ceramic materials include alumina, zirconium oxide, silicon carbide, silicon nitride, and ceramic precursors.

[0019] The present invention provides a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, its preparation method, and its uses, which have the following advantages:

[0020] This invention relates to a high-toughness, low-shrinkage, and easily decomposed photosensitive resin system, thereby eliminating defects such as deformation, warping, delamination, and cracks caused during printing and degreasing processes, and obtaining defect-free ceramic products. Attached Figure Description

[0021] Figure 1 A flowchart illustrating the preparation method of the high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing provided by the present invention.

[0022] Figure 2 This is a product drawing of the silicon carbide structural component prepared according to the present invention. Detailed Implementation

[0023] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0024] The main objective of this invention is to provide a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, its preparation method, and its applications. The photosensitive resin provided by this invention not only possesses high tensile strength and low polymerization shrinkage, but also exhibits gradient decomposition thermal decomposition behavior. This invention provides a high-toughness, low-shrinkage, and easily decomposable photosensitive resin system, thereby eliminating defects such as deformation, warping, delamination, and cracks caused during printing and debinding processes, resulting in defect-free ceramic products.

[0025] The present invention has the following advantages:

[0026] 1. The reactive diluent and polyurethane acrylate used in this invention are blended and copolymerized under ultraviolet light to obtain a three-dimensional network structure through free radical polymerization. The large number of hydrogen bonds in the polyurethane acrylate form a large number of physical crosslinking points, which greatly improves the flexibility of the photosensitive resin after polymerization. The prepared photosensitive resin has excellent tensile properties and the shrinkage rate is reduced to about 3%.

[0027] 2. The additives used in this invention change the thermal decomposition behavior of the photosensitive resin system. Their low-temperature decomposition leaves pores inside the green body, providing a diffusion path for the subsequent decomposition products of the photosensitive resin, and reducing the decomposition rate of the photosensitive resin system. This effectively improves the thermal stress generated by decomposition, thereby inhibiting the formation of cracks.

[0028] 3. The photosensitive resin provided by this invention has the characteristics of abundant raw materials, simple and controllable process, and low cost, which is conducive to industrial production.

[0029] 4. The photosensitive resin provided by this invention is applied to the photopolymerization 3D printing of ceramics, resulting in ceramic products without any defects.

[0030] Example 1

[0031] A method for preparing a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, the specific steps of which are as follows:

[0032] In a 500ml black plastic bottle, add 20g of propylene oxide neopentyl glycol diacrylate, 20g of methyl methacrylate, 20g of ethoxylated trimethylolpropane triacrylate, 25g of aliphatic polyurethane acrylate, and 1g of photoinitiator 819. Mechanically stir at room temperature at a stirring rate of 400r / min for 30-60 minutes to ensure that all components are mixed evenly.

[0033] Add 15g of polymer additive to the above uniformly mixed mixture, and mechanically stir at room temperature at a stirring rate of 400r / min for 30-60 minutes to finally obtain a photosensitive resin with high toughness and low shrinkage properties.

[0034] Examples 2-5

[0035] The preparation steps of a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing are as follows:

[0036] The same preparation process as in Example 1 was used, except that the types and amounts of reactive diluent, polyurethane acrylate, and additives were changed, as shown in the table below:

[0037]

[0038] Comparative Example 1

[0039] Add 1g of photoinitiator 819 to 100g of reactive diluent 2-phenoxyethyl acrylate (PHEA), and stir mechanically at 400r / min for 30-60 minutes to obtain the desired photosensitive resin.

[0040] The performance testing method is as follows:

[0041] 1. Tensile strength and elongation at break were tested in accordance with GB / T 1040.3-2006, with a test temperature of 25℃ and a tensile rate of 2mm / min.

[0042] 2. Shrinkage test: The density ρ1 of the liquid resin was tested using a specific gravity bottle, and the density ρ2 after polymerization was measured using a density balance. The photocuring shrinkage rate of the polymer components was obtained according to ISO 3521:1997.

[0043] S=(ρ2-ρ1) / ρ2×100%

[0044] Three samples were taken from each group, and the average value of the results was taken.

[0045] The test results are shown in Table 2.

[0046] Table 2. Performance test results of photosensitive resins in Comparative Examples 1 and Examples 1-5:

[0047]

[0048]

[0049] As shown in Table 2, the high-toughness, low-shrinkage photosensitive resins provided in Examples 1-5 of this invention have an elongation at break of >90% and a shrinkage rate of <4%, which are significantly better than the photosensitive resin system of Comparative Example 1.

[0050] The photosensitive resin from Example 3 was used for the preparation and printing of ceramic materials (e.g., silicon carbide and alumina). The photopolymerization printing conditions were as follows: a DLP-3D printer was used, with a preferred wavelength of 405 nm and an exposure intensity of 26.67 mW / cm². 2 With an exposure time of 15 seconds and a printing layer thickness of 50 μm, a 3D printed blank without defects such as deformation, warping, or cracks was obtained.

[0051] The obtained green blank is placed in a high-temperature furnace, and after high-temperature degreasing and sintering, a ceramic structural part without any defects is obtained.

[0052] As can be seen from the above embodiments, the photosensitive resin provided by the embodiments of the present invention has excellent properties such as high toughness, low shrinkage, and easy decomposition. Furthermore, when the photosensitive resin provided by the embodiments of the present invention is applied to photopolymerization 3D printing of silicon carbide and alumina, ceramic blanks without defects such as deformation, warping, or cracks can be obtained. After debinding and pre-sintering, no defects are generated, and the samples remain intact. The product image of the silicon carbide structural parts prepared by the present invention is shown below. Figure 2 As shown.

[0053] The degreasing and pre-sintering process is as follows: The prototype part is placed in a tube furnace for degreasing, and heated to 450-900℃ at a heating rate of 0.1℃ / min-1℃ / min under an inert atmosphere, and held at that temperature for 3-5 hours, then cooled to room temperature with the furnace. Subsequently, the degreased sample is placed in a tube furnace for sintering, and heated to 1200℃-1300℃ at a heating rate of 1℃ / min-5℃ / min under an inert atmosphere, and held at that temperature for 4-12 hours, then cooled to room temperature with the furnace, ultimately obtaining a high-precision metal structural part.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, characterized in that, It includes the following raw material components: polyurethane acrylate, reactive diluent, additives and photoinitiator.

2. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The proportions of each raw material component are as follows: by mass parts, 10-35 parts of polyurethane acrylate; 50-80 parts of reactive diluent; 5-30 parts of additives; and 1-5 parts of photoinitiator.

3. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The polyurethane acrylate is selected from either aliphatic polyurethane acrylate or aromatic polyurethane acrylate.

4. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The reactive diluent is selected from one or a mixture of several acrylate and vinyl reactive diluents; The acrylates include isobornyl acrylate (IOBA), octadecyl acrylate (ODA), hydroxyethyl acrylate (HEA), 2-phenoxyethyl acrylate (PHEA), neopentyl glycol diacrylate (NPG2PODA), methyl methacrylate (MMA), 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), dipropylene glycol diacrylate (DPGDA), polyethylene glycol diacrylates (PEG200DA, PEG400DA, or PEG600DA), trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate (PETA), and ethoxylated trimethylolpropane triacrylate (ETPTA).

5. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The additive is a polymeric auxiliary agent that has plasticizing and toughening effects and low-temperature decomposition behavior. The polymeric additives include polyvinyl alcohol, polyethylene glycol, aliphatic diesters, phthalates, polyphenolic esters, benzoates, polyol esters, chlorinated hydrocarbons, epoxy compounds, citrates, and polyesters; wherein, phthalates include phthalates and terephthalates.

6. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The photoinitiator is one or a mixture of several of 819, 184, 369, and TPO.

7. The high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing according to claim 1, characterized in that, The high-toughness, low-shrinkage photosensitive resin used for photopolymerization 3D printing has an elongation at break of >90% and a shrinkage rate of <4%.

8. A method for preparing a high-toughness, low-shrinkage photosensitive resin for photopolymerization 3D printing, characterized in that, Includes the following steps: Step 1: Weigh the polyurethane acrylate, reactive diluent and photoinitiator according to the formula, and mechanically stir them at room temperature at a stirring rate of 300-500 r / min for 30-60 minutes to ensure that the components are mixed evenly. Step 2: Add the additive in the mass ratio to the well-mixed mixture from Step 1, and mechanically stir at room temperature at a stirring rate of 300-500 r / min for 30-60 minutes to finally obtain a photosensitive resin with high toughness and low shrinkage properties.

9. The use of the high-toughness, low-shrinkage photosensitive resin according to any one of claims 1-7 for photopolymerization 3D printing, characterized in that, The high-toughness, low-shrinkage photosensitive resin described herein is used for photopolymer 3D printing, especially for stereolithography, digital light processing, or continuous liquid interface printing applications.

10. The use of the high-toughness, low-shrinkage photosensitive resin according to any one of claims 1-7 for photopolymerization 3D printing, characterized in that, The high-toughness, low-shrinkage photosensitive resin for photocurable 3D printing is used for photocurable 3D printing ceramic materials, wherein the ceramic materials include alumina, zirconium oxide, silicon carbide, silicon nitride, and ceramic precursors.

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