Organosilicon polyurethane acrylate resin as well as preparation method and application thereof

Abstract

The invention discloses organic silicon polyurethane acrylate resin and a preparation method and application thereof.The organic silicon polyurethane acrylate resin is prepared through the steps that hydroxypropyl double-terminated polyether polydimethylsiloxane serves as a soft segment, isophorone diisocyanate serves as a hard segment, tert-butylaminoethyl methacrylate serves as an end-capping reagent, an initiator serves as an initiator, and a solvent serves as a solvent; the reaction is carried out under the action of a catalyst to obtain an organic silicon polyurethane acrylate monomer; the prepared monomer can be directly used as a prepolymer, the prepared organic silicon polyurethane acrylic prepolymer has better light transmission and higher double bond content, the organic silicon polyurethane acrylic prepolymer, 3, 3 '-dimethyl-4, 4'-diaminodicyclohexylmethane and a photoinitiator TPO are mixed according to a specific proportion and then are subjected to photocuring, and the light transmittance of the organic silicon polyurethane acrylic prepolymer is greatly improved. The obtained elastomer has good mechanical properties and high printing precision, and the organosilicon polyurethane acrylate resin has the potential of replacing traditional polyurethane acrylate materials.

Description

Technical Field

[0001] This invention belongs to the field of photopolymerization 3D printing technology, and relates to an organosilicon polyurethane acrylate resin, its preparation method and application. Background Technology

[0002] Photopolymerization 3D printing is an emerging manufacturing technology that can process materials into precisely controlled three-dimensional structures. Elastomers prepared by reduction photopolymerization (3D printing) have attracted great attention in fields such as flexible electronics, wearable devices, and soft robotics due to their efficient molding capabilities and excellent flexibility.

[0003] Currently, the raw materials used for preparing elastomers by photopolymerization 3D printing technology are mostly polyurethane acrylate resins with CO chains as the main component. Compared with traditional polyurethane acrylate elastomers, silicone elastomers have many unique and significant properties due to the alternating Si-O bonds on the main chain and the organic groups on the side chains (such as excellent low-temperature and high-temperature resistance, high transparency, good aging resistance, electrical insulation, low surface energy and biocompatibility).

[0004] Silicone elastomers are generally prepared through platinum-catalyzed hydrosilylation, condensation reactions, or peroxide-initiated free radical reactions. These thermosetting methods typically require rigid molds to manufacture the final product. However, 3D printing technology can easily produce silicone elastomers with complex structures. Researchers have attempted to prepare silicone elastomers using inkjet, direct writing, extrusion, and embedded 3D printing technologies. However, these printing methods all suffer from limited printing resolution. Furthermore, such traditional manufacturing techniques are costly, time-consuming, and unable to produce complex structures. Current synthesis and preparation of silicone photocurable 3D printing resins primarily rely on thiol click reactions, but these reactions are accompanied by high costs and complex synthesis processes. Therefore, there is an urgent need to develop simple and low-cost methods for synthesizing silicone polyurethane acrylates. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a UV-curable silicone polyurethane acrylate resin, its preparation, and its application. The silicone polyurethane acrylate resin uses hydroxypropyl-terminated polyether polydimethylsiloxane as the soft segment, isophorone diisocyanate as the hard segment, and tert-butylaminoethyl methacrylate as the end-capping agent. The process is carried out under the action of a catalyst to obtain a silicone polyurethane acrylate prepolymer (Si-BPU). Then, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and photoinitiator TPO are added to the prepolymer, followed by UV curing to obtain the printed product. This invention adjusts the performance of the printed product by controlling the hydroxyl content in the hydroxypropyl-terminated polyether polydimethylsiloxane and the ratio of hydroxypropyl-terminated polyether polydimethylsiloxane to the hard segment. The printed product of this invention maintains high precision even after thermal post-treatment and significantly improves its mechanical properties. Therefore, it can replace traditional polyurethane acrylate resins and possesses the unique properties of silicone elastomers to meet the needs of different application scenarios.

[0006] The first aspect of this invention provides a method for preparing an organosilicon polyurethane acrylate resin, comprising the following steps: (1) Add isophorone diisocyanate and catalyst to hydroxypropyl double-terminated polyether polydimethylsiloxane and heat the reaction. (2) Tert-butylaminoethyl methacrylate is added to the reaction system in step (1) for end capping, and the reaction is continued at a constant temperature to obtain the organosilicon polyurethane acrylate resin.

[0007] According to an embodiment of the present invention, the hydroxypropyl dual-terminated polyether polydimethylsiloxane has a number-average molecular weight of 2000 and a chemical formula of:

[0008] According to an embodiment of the present invention, the hydroxyl content in the hydroxypropyl double-terminated polyether polydimethylsiloxane is 1-2%, for example 1.7%.

[0009] According to an embodiment of the present invention, the molar ratio of the hydroxypropyl dual-terminated polyether polydimethylsiloxane, isophorone diisocyanate and tert-butylaminoethyl methacrylate is 1:(0.1-5):(0.1-5), preferably 1:(0.5-3):(0.5-3), for example 1:0.1:0.1, 1:0.1:5, 1:0.1:5, 1:2:2, 1:1:1 or 1:3:3, 1:0.5:3, 1:0.5:5 or 1:5:5.

[0010] According to an embodiment of the present invention, the amount of the catalyst is 0.01 to 0.1 wt% of hydroxypropyl dual-terminated polyether polydimethylsiloxane, for example, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.08 wt%, or 0.1 wt%.

[0011] According to an embodiment of the present invention, the catalyst is one of dibutyltin dilaurate and organobismuth.

[0012] According to an embodiment of the present invention, in step (1), isophorone diisocyanate and catalyst are premixed to obtain a mixture, which is then added dropwise to hydroxypropyl double-terminated polyether polydimethylsiloxane.

[0013] According to an embodiment of the present invention, the hydroxypropyl dual-terminated polyether polydimethylsiloxane needs to be dehydrated under reduced pressure before being added to the reaction system. For example, the dehydration temperature is 60~120℃, such as 60℃, 80℃, 100℃ or 120℃; the dehydration time is 0.5~4h, such as 0.5h, 1h, 2h, 3h or 4h.

[0014] According to an embodiment of the present invention, the isothermal temperature of the heating reaction is 40~60℃, for example 40℃, 50℃ or 60℃; the isothermal time of the heating reaction is 1~4h, for example 1h, 2h, 3h or 4h.

[0015] According to an embodiment of the present invention, in step (2), the reaction time is 1 to 4 hours, for example, 1 hour, 2 hours, 3 hours or 4 hours.

[0016] According to an embodiment of the present invention, the preparation method further includes cooling to room temperature after the reaction is completed, and then discharging the material.

[0017] A second aspect of the present invention provides an organosilicon polyurethane acrylate resin prepared according to the above preparation method.

[0018] A third aspect of the present invention provides the application of organosilicon polyurethane acrylate resin in 3D printing.

[0019] The present invention also provides an organosilicon polyurethane acrylate elastomer, which is prepared by UV curing and heat post-treatment of the above-mentioned organosilicon polyurethane acrylate resin.

[0020] This invention also provides a method for preparing the above-mentioned organosilicon polyurethane acrylate elastomer, the method comprising the following steps: (1) Add 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and a photoinitiator to the above-mentioned organosilicon polyurethane acrylate resin; (2) Cured under UV light and subjected to heat post-treatment to obtain silicone polyurethane acrylate elastomer.

[0021] According to an embodiment of the present invention, the mass ratio of the organosilicon polyurethane acrylate resin to 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane is 40:(1-10), preferably 40:(1-5), for example 40:3.

[0022] According to an embodiment of the present invention, the photoinitiator is 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO).

[0023] According to an embodiment of the present invention, the amount of photoinitiator is 0.1-5% of the mass of the organosilicon polyurethane acrylate resin, preferably 0.5-2%, for example 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 3%, 4% or 5%.

[0024] According to an embodiment of the present invention, step (1) further includes stirring the mixture and vacuum degassing. For example, the vacuum degassing time is 1 to 10 minutes, such as 5 minutes.

[0025] According to an embodiment of the present invention, the temperature of the heat treatment is 80~120℃, for example 100℃, and the time of the heat treatment is 1~12h, for example 8h.

[0026] The beneficial effects of this invention are: This invention uses hydroxypropyl-terminated polyether polydimethylsiloxane as the soft segment, isophorone diisocyanate as the hard segment, and tert-butylaminoethyl methacrylate as the end-capping agent, under the action of a catalyst to obtain an organosilicon polyurethane acrylate prepolymer. By controlling the proportion of hydroxyl groups in the hydroxypropyl-terminated polyether polydimethylsiloxane, this invention prepares an organosilicon polyurethane acrylate prepolymer with good light transmittance (82.77% transmittance at 450nm) and a high double bond content. This invention further utilizes photocuring of the organosilicon polyurethane acrylate prepolymer, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and photoinitiator TPO to obtain an elastomer with good mechanical properties and high printing precision. The organosilicon polyurethane acrylate resin synthesized in this invention has the potential to replace traditional polyurethane acrylate materials. Attached Figure Description

[0027] Figure 1 In the figures (a), (b), and (c), respectively, are the infrared curves of hydroxypropyl double-terminated polyether polydimethylsiloxane, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-2, and UV-curable silicone polyurethane acrylate resin in Example 1.

[0028] Figure 2This is a comparison of the mechanical properties of the photocurable silicone-modified polyurethane acrylic elastomer in Example 1 before and after heat treatment.

[0029] Figure 3 The transmittance of the UV-cured silicone polyurethane acrylate elastomer in Example 1 was measured using a UV spectrophotometer. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0031] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0032] Example 1: Preparation of silicone polyurethane acrylate resin Si-BPU-2 (R=N-NCO / N-OH) and UV-cured silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicon Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 44.8g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel under stirring at 40℃. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 44.8g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel under stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-2.

[0033] Under light-protected conditions, 20g of Si-BPU-2 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain a UV-cured silicone-modified polyurethane acrylate elastomer.

[0034] Figure 1In Figures (a), (b), and (c), the infrared spectra of hydroxypropyl dual-terminated polyether polydimethylsiloxane, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-2, and UV-curable silicone polyurethane acrylate resin, respectively, are shown. As can be seen from the figures, this invention successfully prepared a silicone polyurethane acrylate prepolymer using hydroxypropyl dual-terminated polyether polydimethylsiloxane as the soft segment, isophorone diisocyanate as the hard segment, and tert-butylaminoethyl methacrylate as the end-capping agent under the action of a catalyst. Furthermore, a silicone polyurethane acrylate resin was successfully prepared by mixing the silicone polyurethane acrylate prepolymer, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and the photoinitiator TPO followed by photocuring.

[0035] Figure 2 This is a comparison of the mechanical properties of the photocurable silicone-modified polyurethane acrylic elastomer in Example 1 before and after heat treatment (1KN tensile test using a universal testing machine). As can be seen from the figure, the elastomer prepared in this example possesses superior mechanical properties, with a tensile strength of 8.76 MPa and an elongation at break of 405%.

[0036] Figure 3 The transmittance of the UV-cured silicone polyurethane acrylate elastomer in Example 1 was measured using a UV spectrophotometer. As can be seen from the figure, the elastomer prepared in this example has high transmittance, with a transmittance of 82.77% at 450 nm.

[0037] Example 2: Preparation of silicone polyurethane acrylate resin Si-BPU-1.4 (R=N-NCO / N-OH) and UV-cured silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicon Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 31.2g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel at 40℃ with stirring. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 31.2g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel with stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-1.4.

[0038] Under light-protected conditions, 20g of Si-BPU-1.4 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain the photocurable silicone-modified polyurethane acrylate elastomer.

[0039] Example 3: Preparation of silicone polyurethane acrylate resin Si-BPU-1.6 (R=N-NCO / N-OH) and UV-cured silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicon Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 35.6g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel at 40℃ with stirring. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 35.6g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel with stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-1.6.

[0040] Under light-protected conditions, 20g of Si-BPU-1.6 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain the photocurable silicone-modified polyurethane acrylate elastomer.

[0041] Example 4: Preparation of silicone polyurethane acrylate resin Si-BPU-1.8 (R=N-NCO / N-OH) and UV-cured silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicone Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 40g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel at 40℃ with stirring. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 40g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel with stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-1.8.

[0042] Under light-protected conditions, 20g of Si-BPU-1.8 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain the photocurable silicone-modified polyurethane acrylate elastomer.

[0043] Example 5: Preparation of silicone polyurethane acrylate resin Si-BPU-2.2 (R=N-NCO / N-OH) and UV-cured silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicon Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 49.2g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel under stirring at 40℃. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 49.2g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel under stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-2.2.

[0044] Under light-protected conditions, 20g of Si-BPU-2.2 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain the photocurable silicone-modified polyurethane acrylate elastomer.

[0045] Example 6: Preparation of UV-curable silicone polyurethane acrylate resin Si-BPU-2.4 (R=N-NCO / N-OH) and UV-curable silicone polyurethane acrylate elastomer 200g of hydroxypropyl dual-terminated polyether polydimethylsiloxane (number average molecular weight 2000, purchased from Anhui Aiyota Silicon Oil Co., Ltd.) was dehydrated under reduced pressure in a vacuum oven at 100℃ for 2h. Then, 53.6g of isophorone diisocyanate and a premix of dibutyltin dilaurate (0.02% of hydroxypropyl dual-terminated polyether polydimethylsiloxane) were added dropwise to the system through a constant-pressure dropping funnel at 40℃ with stirring. After the addition was complete, the temperature was raised to 50℃ and maintained for 3h. Then, while maintaining 50℃, 53.6g of tert-butylaminoethyl methacrylate was added dropwise to the system through a constant-pressure dropping funnel with stirring. After reacting for 3h, the mixture was cooled to room temperature and discharged to obtain the target product, UV-curable silicone polyurethane acrylate prepolymer Si-BPU-2.4.

[0046] Under light-protected conditions, 20g of Si-BPU-2.4 was mixed with 1.5% of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and 1% of photoinitiator TPO, and the mixture was vacuum stirred and degassed for 5 minutes. The resulting silicone polyurethane acrylate 3D printing resin was poured into a silicone mold and cured under 80% UV light for 10 seconds. The sample was then removed and heat-treated in an oven at 100℃ for 12 hours to obtain the photocurable silicone-modified polyurethane acrylate elastomer.

[0047] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an organosilicon polyurethane acrylate resin, characterized in that, Includes the following steps: (1) Add isophorone diisocyanate and catalyst to hydroxypropyl double-terminated polyether polydimethylsiloxane and heat the reaction. (2) Tert-butylaminoethyl methacrylate is added to the reaction system in step (1) for end capping, and the reaction is continued at a constant temperature to obtain the organosilicon polyurethane acrylate resin.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the hydroxypropyl dual-terminated polyether polydimethylsiloxane, isophorone diisocyanate and tert-butylaminoethyl methacrylate is 1:(0.1-5):(0.1-5), preferably 1:(0.5-3):(0.5-3).

3. The preparation method according to claim 1 or 2, characterized in that, The amount of the catalyst used is 0.01~0.1 wt% of hydroxypropyl double-terminated polyether polydimethylsiloxane; And / or, the catalyst is one of dibutyltin dilaurate and organobismuth, etc.

4. The preparation method according to any one of claims 1-3, characterized in that, The isothermal temperature of the heating reaction is 40~60℃, and the isothermal time of the heating reaction is 1~4h; And / or, in step (2), the reaction time is 1 to 4 hours.

5. An organosilicon polyurethane acrylate resin prepared by the preparation method according to any one of claims 1-4.

6. The application of the silicone polyurethane acrylate resin of claim 5 in 3D printing.

7. An organosilicon polyurethane acrylate elastomer, characterized in that, It is prepared by UV curing and thermal post-treatment of the organosilicon polyurethane acrylate resin as described in claim 5.

8. The method for preparing the organosilicon polyurethane acrylate elastomer according to claim 7, characterized in that, The method includes the following steps: (1) Add 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane and a photoinitiator to the organosilicon polyurethane acrylate resin according to claim 5; (2) Cured under UV light and subjected to heat post-treatment to obtain silicone polyurethane acrylate elastomer.

9. The preparation method according to claim 8, characterized in that, The mass ratio of the organosilicon polyurethane acrylate resin to 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane is 40:(1-10), preferably 40:(1-5). And / or, the photoinitiator TPO is 2,4,6-trimethylbenzoyldiphenylphosphine oxide; And / or, the photoinitiator accounts for 0.1-5% of the mass of the organosilicon polyurethane acrylate resin, preferably 0.5-2%.

10. The preparation method according to claim 8, characterized in that, The temperature of the heat treatment is 80~120℃, and the time of the heat treatment is 1~12h.

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