High thermal deflection temperature ductile photopolymerizable materials and additive manufacturing methods
By using a photopolymer composition containing oligomers, monomers, and photoinitiators, and employing additive manufacturing and dual-curing methods, the problem of manufacturing complex parts with high thermal flexural temperature and high elongation at break in the prior art has been solved, and high-performance dual-curing parts have been prepared.
Patent Information
- Application Number
- CN202510512495.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-26
- Filing Date
- 2025-04-23
- Publication Date
- 2025-10-28
AI Technical Summary
Existing additive manufacturing technologies struggle to produce complex parts with high thermal flexural temperature and high elongation at break without using molds or machining.
A photopolymer composition comprising oligomers, monomers and photoinitiators is used to prepare dual-cured parts through additive manufacturing and a dual curing process (UV curing and thermal curing). The oligomers have a glass transition temperature above 100°C, and the monomers and photoinitiators are in a specific ratio range to ensure that the final product has a thermal flexural temperature between 100°C and 250°C and an elongation at break of 5% to 20%.
This technology enables the fabrication of parts with high thermal flexural temperature and high elongation at break in additive manufacturing, meeting the mechanical performance requirements of complex parts.
Smart Images
Figure CN120842501A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to photopolymer materials, and in particular, to dual-cured components produced from photopolymerizable material compositions. Background Technology
[0002] The statements in this section are provided only as background information in connection with this disclosure and may not constitute prior art.
[0003] Additive manufacturing (AM) (also known as “3D printing”) is a manufacturing technology used to produce parts by sequentially depositing and curing materials, enabling step-by-step assembly of parts. Additive manufacturing has been widely used in various fields, including the automotive industry, to manufacture complex objects without the need for molds or machining. Reduction photopolymerization curing (VPP) methods (such as stereolithography (SLA) and digital light processing (DLP)) are AM processes in which a liquid photopolymer in a tank is selectively cured by a light source. During the curing process, the photopolymer polymerizes via a free radical reaction when exposed to light of a specific wavelength, particularly ultraviolet (UV) radiation. Once the radiation is removed, the curing of the resin stops. Depending on the application, a second curing process can be used to adjust the properties of the AM parts. Post-curing techniques include additional UV curing and thermal curing.
[0004] This disclosure resolves these problems related to AM. Summary of the Invention
[0005] This section provides a general overview of this disclosure and is not a full disclosure of its entire scope or all its features.
[0006] According to one form of this disclosure, a photopolymer composition comprises: an oligomer having a glass transition temperature above about 100°C; a monomer, wherein the oligomer is soluble in the monomer; and a photoinitiator. After double curing, the composition has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
[0007] In variations of this form, which may be implemented alone or in any combination: the oligomer is at least one of the following: UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, polyimide, or UV-curable polyester; the molecular weight of the oligomer is between about 1000 g / mol and 10000 g / mol; the composition has a thermal flexural temperature between about 130°C and 250°C; the monomer is hydrophobic; the monomer comprises monofunctional, difunctional, or multifunctional UV-curable functional groups; the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, and (meth)acrylates; the oligomer is in the range of about 20% by weight to 80% by weight; the monomer is in the range of about 20% by weight to 80% by weight; and the photoinitiator is in the range of about 0.5% by weight to 5% by weight.
[0008] According to a second aspect of this disclosure, a method for manufacturing a dual-cured polymer component includes: additively manufacturing a green component from a liquid photopolymerizable material; and performing dual post-curing of the green component by UV curing and thermosetting to form the dual-cured component. The liquid photopolymerizable material has a composition comprising: an oligomer with a glass transition temperature above about 100°C, a monomer, and a photoinitiator. The thermosetting step is performed in a nitrogen environment at a temperature above the glass transition temperature of the oligomer. The dual-cured component has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
[0009] In variations of this form, which may be implemented alone or in any combination: the oligomer is at least one of the following: UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, polyimide, or UV-curable polyester; the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, and (meth)acrylates; and the oligomer is in the range of about 20% by weight to 80% by weight, and the monomer is in the range of about 20% by weight to 80% by weight.
[0010] According to a third aspect of this disclosure, a dual-cured component is manufactured by additive manufacturing from a liquid photopolymerizable material. The photopolymerizable material comprises: an oligomer having a glass transition temperature above about 100°C; a monomer in which the oligomer is soluble; and a photoinitiator. After dual curing, the composition has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
[0011] In variations of this form, which may be implemented alone or in any combination: the oligomer is at least one of the following: UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, polyimide, or UV-curable polyester; the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, and (meth)acrylates; the monomer comprises a monofunctional, bifunctional, or multifunctional UV-curable functional group; the oligomer is in the range of about 20% by weight to 80% by weight of the composition; and the monomer is in the range of about 20% by weight to 80% by weight.
[0012] Further applicable areas will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description
[0013] To better understand this disclosure, various forms of the disclosure will now be described by way of example with reference to the accompanying drawings, in which:
[0014] Figure 1 A method for manufacturing dual-cured polymer parts by additive manufacturing, according to one aspect of this disclosure, is shown;
[0015] Figure 2 A schematic diagram of a UV curing process according to one aspect of this disclosure is shown;
[0016] Figure 3 This is a set of graphs showing the HDT and ductility data of a comparative curing method according to one aspect of this disclosure;
[0017] Figures 4 to 15 It is a graph showing the tensile data of a photopolymer material having a composition according to the teachings of this disclosure.
[0018] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation
[0019] The following description is merely exemplary in nature and is not intended to limit this disclosure, its application, or its uses. It should be understood that throughout the accompanying drawings, corresponding reference numerals indicate the same or corresponding parts and features.
[0020] Figure 1 A process for manufacturing dual-cured polymer parts via additive manufacturing is illustrated. First, a green part is manufactured from a liquid polymerizable material using an additive manufacturing process. The additive manufacturing process is a reduction photopolymerization curing process, such as stereolithography or digital photoprocessing. As discussed in more detail below, the photopolymerizable material includes oligomers, monomers, and photoinitiators.
[0021] During the AM process, photopolymerizable materials are cured in layers by ultraviolet (UV) light to build components. Figure 2 The structural changes are shown when the polymer is cured. UV light decomposes the photoinitiator. The resulting free radicals initiate crosslinking polymerization and produce solid green parts.
[0022] Next, the green part is subjected to dual post-curing via both UV curing and thermal curing to produce a dual-cured part. In one embodiment, the green part is UV cured for 2 hours. The thermal curing step is performed in a nitrogen environment at a temperature above the glass transition temperature of the oligomer. Specifically, thermal curing is performed at a temperature above 100°C. In one embodiment, thermal curing includes heating the UV-cured part to a temperature of 220°C for 16 hours. After thermal curing, the polymer crosslinking is completed, and the physical and mechanical properties of the part are formed.
[0023] For the purposes of this disclosure, components that have been UV-cured and heat-cured are referred to herein as 'double-cured'. The double-cured components have a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%. The properties are discussed in more detail below.
[0024] Returning to the composition of the photopolymerizable material, as described above, the material comprises oligomers, monomers, and a photoinitiator. In one form, the oligomer content is in the range of about 20% by weight to about 80% by weight of the photopolymerizable material composition; the monomer content is in the range of about 20% by weight to about 80% by weight; and the photoinitiator content is in the range of about 0.5% by weight to about 5% by weight, up to a maximum weight percentage of 100%.
[0025] The oligomer plays a crucial role in determining the properties of the final product. The oligomer must be soluble in the monomer and UV-curable. Due to the requirements of the additive manufacturing process, the photopolymerizable material must be liquid at room temperature when the oligomer is dissolved in the monomer. Additionally, the oligomer has a glass transition temperature above about 100°C. In one form, the oligomer has an elongation at break above about 5% in the case of self-polymerization. In another form, the molecular weight of the oligomer is between about 1000 g / mol and 10000 g / mol. The oligomer includes one or more of UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, UV-curable polyimide, and UV-curable polyester. However, other oligomer materials may be utilized if they possess the described properties.
[0026] Monomers provide functional groups for the polymerization process and a medium for dissolving oligomers. If a mixture of monomers is used, the oligomers can be dissolved in at least one monomer, while the other monomers provide additional properties. The monomers have low volatility, high ductility, and high hardness (HDT), and include one or more monofunctional, difunctional, or polyfunctional UV-curable functional groups. More specifically, the monomers include one or more of styrene, styrene derivatives, acrylates, and methacrylates. In one form, the monomer is hydrophobic, resulting in a water-stable composition.
[0027] This includes photoinitiators to initiate the curing process of oligomers and monomers upon exposure to UV radiation. UV light breaks down the photoinitiator into free radicals that initiate the crosslinking process. In one form, the photoinitiator is ethyl (2,4,6-trimethylbenzoyl)phenylphosphine oxide or phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.
[0028] In one form, the photopolymerizable composition also includes additives added to modify its properties. These additives may be graphene, cellulose, carbon black, or carbon nanotubes.
[0029] Table 1 below includes examples of compositions according to this disclosure, which have been cured and tested under different conditions to determine the resulting HDT and elongation at break. Each of the examples includes a UV-curable solid PPE as an oligomer, and styrene, acrylate (CD595), and methacrylate (AOMA) as monomers. TM It also includes 1% photoinitiator. The example was UV cured for 2 hours.
[0030]
[0031] Table 1
[0032] Figure 3 The graphs show the test results for Examples 1 and 3, and Examples 4 and 5. Examples 3 and 5 were cured in a nitrogen environment and exhibited increased elongation at break compared to Examples 1 and 4, which were cured in air, demonstrating the effect of thermosetting in a nitrogen environment relative to air. Figures 4 to 7 The graphs show the tensile test results for Example 1 and Examples 3 through 5.
[0033] Comparing Example 3 and Example 2 shows that the dual-cured part of Example 3 has an increased HDT compared to Example 2, which only undergoes UV curing.
[0034] Examples 3 and 5 through 13 are double-cured samples of compositions according to this disclosure. Each example has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
[0035] Samples of Examples 1 to 9 were produced by solution casting to test the compositions and curing methods. Figures 8 to 11 These are graphs showing the tensile test results for Examples 6 to 9.
[0036] Figures 12 to 15 This is a graph showing the tensile test results for Examples 10 to 13. The samples for Examples 10 to 13 were produced by 3D printing on a Digital Light Processing (DLP) printer. It can be seen that HDT and ductility are not negatively affected by the 3D printing process.
[0037] Unless otherwise expressly indicated herein, all numerical values indicating mechanical / thermal properties, percentage of composition, dimensions and / or tolerances or other characteristics should be understood as being modified by the words “about” or “approximately” when describing the scope of this disclosure. Such modification is desired for various reasons, including: industrial practice; material, manufacturing and assembly tolerances; and testing capabilities.
[0038] As used herein, the phrases A, B, and C at least one should be interpreted as using the non-exclusive logic "or" to represent logic (A or B or C), and should not be interpreted as meaning "at least one of A, at least one of B, and at least one of C".
[0039] The description in this disclosure is merely exemplary in nature, and therefore, variations without departing from the spirit and scope of this disclosure are intended to be made within its scope. Such variations should not be considered as departing from the spirit and scope of this disclosure.
[0040] According to the present invention, a dual-cured component manufactured by additive manufacturing from a liquid photopolymerizable material is provided, the photopolymerizable material comprising: an oligomer having a glass transition temperature above about 100°C; a monomer, wherein the oligomer is soluble in the monomer; and a photoinitiator, wherein the dual-cured component has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
[0041] According to the embodiments, the oligomer is at least one of UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, UV-curable polyimide, or UV-curable polyester.
[0042] According to an embodiment, the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, acrylates and (meth)acrylates.
[0043] According to an embodiment, the monomer includes monofunctional, difunctional, or multifunctional UV-curable functional groups.
[0044] According to an embodiment, the oligomer is in the range of about 20% by weight to 80% by weight.
[0045] According to an embodiment, the monomer is in the range of about 20% by weight to 80% by weight.
Claims
1. A photopolymer composition comprising: Oligomers having a glass transition temperature above about 100°C; Monomers, wherein the oligomers are soluble in the monomers; as well as Photoinitiator, After double curing, the composition has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
2. The photopolymer composition of claim 1, wherein the oligomer is at least one of UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, UV-curable polyimide, or UV-curable polyester.
3. The photopolymer composition of claim 1, wherein the molecular weight of the oligomer is between about 1000 g / mol and 10000 g / mol.
4. The photopolymer composition of claim 1, wherein the composition has a thermal flexural temperature between about 130°C and 250°C.
5. The photopolymer composition of claim 1, wherein the monomer is hydrophobic.
6. The photopolymer composition of claim 1, wherein the monomer comprises a monofunctional, difunctional, or multifunctional UV-curable functional group.
7. The photopolymer composition of claim 1, wherein the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, acrylates and (meth)acrylates.
8. The photopolymer composition of claim 1, wherein the oligomer is in the range of about 20% to 80% by weight.
9. The photopolymer composition of claim 1, wherein the monomer is in the range of about 20% by weight to 80% by weight.
10. The photopolymer composition of claim 1, wherein the photoinitiator is in the range of about 0.5% by weight to 5% by weight.
11. A method for manufacturing a dual-curing polymer component, the method comprising: Additive manufacturing of green parts from a liquid photopolymerizable material, the liquid photopolymerizable material having a composition comprising: an oligomer with a glass transition temperature higher than about 100°C, a monomer, and a photoinitiator; and The green component is subjected to dual post-curing via UV curing and thermal curing to form the dual-cured component. The thermal curing is performed in a nitrogen environment at a temperature higher than the glass transition temperature of the oligomer. The dual-cured component has a thermal flexural temperature between about 100°C and 250°C and an elongation at break between about 5% and 20%.
12. The method of claim 11, wherein the oligomer is at least one of UV-curable polyphenylene ether (PPE), UV-curable polycarbonate, UV-curable bismaleimide, UV-curable polyamide, UV-curable polyimide, or UV-curable polyester.
13. The method of claim 11, wherein the monomer comprises one or more materials selected from the group consisting of styrene, styrene derivatives, acrylates and (meth)acrylates.
14. The method of claim 11, wherein the oligomer is in the range of about 20% by weight to 80% by weight, and the monomer is in the range of about 20% by weight to 80% by weight.