Method for autocatalytic synthesis of UV light-cured trapezoidal polysiloxane resin, UV light-cured trapezoidal polysiloxane multi-acrylic resin and application of UV light-cured trapezoidal polysiloxane multi-acrylic resin
By synthesizing UV-curable trapezoidal tertiary amine polysiloxane resin through autocatalysis, the problem of catalyst removal difficulty was solved, achieving efficient and environmentally friendly synthesis of trapezoidal polysiloxane resin and improving coating hardness and molecular weight control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUOKE GUANGHUA FINE CHEM INCUBATOR (NANXIONG) CO LTD
- Filing Date
- 2026-02-26
- Publication Date
- 2026-05-12
AI Technical Summary
In the existing synthesis process of ladder-shaped polysiloxane resin, the difficulty in removing the catalyst leads to low yield and the generation of wastewater and waste materials, which is not conducive to environmental protection and cost saving.
A self-catalytic method was adopted, in which an aminosilane coupling agent containing tertiary amine groups was mixed with other silane coupling agents, and after hydrolysis and condensation, an end-capping agent was added to prepare a UV-curable ladder-shaped tertiary amine polysiloxane resin. After the reaction, the tertiary amine groups became part of the polymer, and there was no need to remove the catalyst.
It simplifies the synthesis process, avoids catalyst removal steps, reduces waste generation, improves yield and coating hardness, concentrates molecular weight distribution, and extends resin shelf life.
Smart Images
Figure CN122011395A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of advanced photocurable organosilicon materials, specifically relating to a method for autocatalytic synthesis of UV-curable trapezoidal polysiloxane resin, UV-curable trapezoidal polyacrylic acid resin and its applications. Background Technology
[0002] Advanced photocurable silicone materials combine the advantages of high-molecular polymers and environmental friendliness. Unlike other materials that require complex curing methods such as thermal curing or moisture curing, they can rapidly cross-link and cure under ultraviolet light, offering high efficiency and environmental friendliness. For this reason, advanced silicone materials have always been a research hotspot in various research directions. Among them, polysiloxane resins are one of the main research directions for advanced photocurable silicone materials. Polysiloxane resins are multi-component polymers with a Si-O-Si framework. Due to their thermal stability, hydrophobicity, chemical inertness, and processability, they are widely used in coatings, construction, textiles, and other fields. They are currently the most researched photocurable silicone materials. Among polysiloxane resins, ladder-shaped polysiloxanes, due to their double-chain Si-O-Si structure, have higher thermal stability and mechanical properties than ordinary polysiloxane resins. The double-chain structure means that more functional groups can be linked to the main chain, allowing for better selection of different silane coupling agents to impart different properties to the resin according to actual needs. However, the synthesis of ladder-shaped polysiloxane resins usually requires the addition of a catalyst, such as hydrochloric acid or potassium carbonate, to provide acidic or alkaline conditions for catalysis. This leads to the problem of catalyst removal after the reaction. Liu Guojun et al. used anhydrous potassium carbonate as a catalyst to synthesize an epoxycyclohexyl ladder-shaped polysiloxane, but the subsequent removal of anhydrous potassium carbonate required multiple water washings and filtrations, resulting in significant product loss and low yield. Furthermore, multiple filtrations generate a large amount of wastewater and waste materials, which is detrimental to environmental protection and cost savings. Yoshiro Kaneko et al. in Japan used hydrochloric acid as a catalyst to synthesize an amino ladder-shaped polysiloxane resin, but subsequent freeze-drying was required to remove the catalyst. Therefore, how to efficiently synthesize ladder-shaped polysiloxanes while separating the product from the catalyst remains a challenge. Summary of the Invention
[0003] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for the self-catalytic synthesis of UV-curable trapezoidal polysiloxane resin.
[0004] Another object of the present invention is to provide a UV-curable trapezoidal tertiary amine polysiloxane resin.
[0005] Another object of the present invention is to provide a method for preparing a UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin.
[0006] Another object of the present invention is to provide a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin.
[0007] Another object of the present invention is to provide an application of a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin.
[0008] The objective of this invention is achieved through the following technical solution:
[0009] A method for autocatalytic synthesis of UV-curable ladder-shaped tertiary amine polysiloxane resin includes the following steps:
[0010] An aminosilane coupling agent containing a tertiary amine group, a phenylsilane coupling agent, an acryloyloxysilane coupling agent, and an organic solvent are mixed evenly, then water is added, and after reacting for a period of time, an end-capping agent is added. After the reaction is completed, the solvent in the product is removed to obtain a UV-curable ladder-shaped tertiary amine polysiloxane resin.
[0011] Preferably, the aminosilane coupling agent containing a tertiary amine group is at least one of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, and (N,N-dimethyl-3-aminopropyl)triethoxysilane.
[0012] The phenylsilane coupling agent is at least one of phenyltrimethoxysilane and phenyltriethoxysilane;
[0013] The acryloyloxysilane coupling agent is at least one of 3-(isobutenoyloxy)propyltrimethoxysilane, 3-(methacryloyloxy)propyltriethoxysilane, and 3-acryloyloxypropyltrimethoxysilane.
[0014] The organic solvent is at least one of dichloromethane and tetrahydrofuran;
[0015] The capping agent is at least one of trimethylethoxysilane and methoxytrimethylsilane.
[0016] Preferably, the molar ratio of the aminosilane coupling agent containing tertiary amine groups, the phenylsilane coupling agent, the acryloyloxysilane coupling agent, and the end-capping agent is 0.5~1:1:1:0.5~1;
[0017] Preferably, the molar ratio of the aminosilane coupling agent containing tertiary amine groups, the phenylsilane coupling agent, and the acryloyloxysilane coupling agent is 1:1:1.
[0018] The molar ratio of the phenylsilane coupling agent to water is 1:5~9;
[0019] The ratio of solvent to silane coupling agent is 15~50 g: 0.1~0.5 mol;
[0020] The silane coupling agents include aminosilane coupling agents containing tertiary amine groups, phenylsilane coupling agents, and acryloyloxysilane coupling agents.
[0021] The reaction temperature is 30 ~ 40 ℃, and the reaction time is 48 ~ 96 h;
[0022] The capping agent is added at 1 / 3 to 1 / 2 of the reaction time, specifically after 24 to 48 hours of reaction.
[0023] A UV-curable ladder-shaped tertiary amine polysiloxane resin is prepared by the method described above.
[0024] A method for preparing UV-curable ladder-shaped tertiary amine polyacrylic acid resin using the above-mentioned UV-curable ladder-shaped polysiloxane resin is characterized by comprising the following steps:
[0025] UV-curable trapezoidal tertiary amine polysiloxane resin is mixed with polyacrylate to obtain UV-curable trapezoidal tertiary amine polysiloxane polyacrylate resin.
[0026] Preferably, the polyacrylate is at least one of trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and pentaerythritol triacrylate;
[0027] The mass ratio of the polyacrylate to the UV-curable ladder-shaped tertiary amine polysiloxane resin is 0.5~2:0.5~4;
[0028] A UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin is prepared by the above method.
[0029] The above-mentioned UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin is used in the preparation of coatings, coating materials, film-forming compositions or protective coatings.
[0030] Preferably, the coating, coating material, film-forming composition, or protective coating comprises the following components: a ladder-shaped tertiary amine polysiloxane polyacrylic resin, a photoinitiator, and an organic solvent;
[0031] The amount of photoinitiator used is 7%-10wt% of the mass of the ladder-shaped tertiary amine polysiloxane polyacrylic acid resin.
[0032] Preferably, the initiator is a hydrogen-abstracting photoinitiator;
[0033] The organic solvent is at least one of butyl acetate, propyl acetate, and ethyl acetate;
[0034] The mass ratio of the organic solvent to the photoinitiator is 2~3:0.7~1.
[0035] The mechanism of this invention is as follows:
[0036]
[0037] Equation (1)
[0038] This invention first involves mixing a tertiary amine silane coupling agent with other silane coupling agents, followed by hydrolysis and condensation to obtain a preliminary ladder-shaped polysiloxane (as shown in formula (1) structure (I)). Then, a capping agent is added to prevent further condensation of the product, resulting in a ladder-shaped tertiary amine polysiloxane resin (as shown in formula (1) structure (II)). This resin is then mixed with polyacrylate. After adding a photoinitiator, the tertiary amine groups form free radicals under the action of the photoinitiator, attacking the double bonds and initiating free radical polymerization, thereby curing the resin into a film (as shown in formula (1) process (①) and process (②)). After the free radical polymerization begins, the double bonds of the ladder-shaped tertiary amine polysiloxane resin randomly combine and crosslink with the double bonds of the polyacrylate resin, forming a dense three-dimensional network structure, thereby increasing the hardness of the photocurable coating.
[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0040] (1) The synthesis method is simple. One of the raw materials, the tertiary amino silane coupling agent, can provide an alkaline environment for the reaction system. No catalyst is needed. After the reaction is completed, the tertiary amino silane coupling agent will become part of the polymer. No catalyst removal, separation, filtration and other operations are required.
[0041] (2) No wastewater or waste is generated. Only the solvent needs to be removed by rotary evaporation of the product, and the solvent can be recycled and reused.
[0042] (3) Polyacrylates have more double bonds and a high degree of cross-linking, which ensures their mechanical properties.
[0043] (4) Compared with the traditional synthesis method using K2CO3 as a catalyst, the present invention optimizes the addition time of the end capping agent during the synthesis process, which not only achieves controllable adjustment of the target molecular weight of polysiloxane resin, but also significantly reduces the molecular weight polydispersity of the polymer.
[0044] (5) Polyacrylate resins are very easy to solidify and can only be stored for 3 weeks to 2 months. However, this resin can store the ladder-shaped tertiary amine polysiloxane resin and polyacrylate separately and then mix them when used. The sample has high stability and can extend the storage time, without solidifying for 5 months.
[0045] (6) The prepared ladder-shaped tertiary amine polysiloxane resin itself has tertiary amine groups, so there is no need to add tertiary amine substances to initiate photocuring free radical polymerization, which is very suitable for hydrogen abstraction photoinitiators.
[0046] (7) The coating prepared by the present invention has a hardness of 5H~7H, which is at the same excellent level as the coating hardness of polymers synthesized by the traditional K2CO3 catalytic system. Attached Figure Description
[0047] Figure 1 The FTIR spectra of cage-like POSS-type polysiloxane, Comparative Example 2 (Sample 2), Example 1 (Sample 1), and Example 2 (Sample 3) are represented by numbers 1 to 4.
[0048] Figure 2 TG curves for cage-like POSS-type polysiloxane, Comparative Example 2 (Sample 2), Example 1 (Sample 1), and Example 2 (Sample 3).
[0049] Figure 3 The image shows the XRD pattern of cage-like POSS-type polysiloxane.
[0050] Figure 4 The XRD patterns are for Comparative Example 2 (Sample 2), Example 1 (Sample 1), and Example 2 (Sample 3), corresponding to numbers 1 to 3.
[0051] Figure 5 Sample 3 of Example 2 29 Si NMR spectrum.
[0052] Figure 6 This is the GPC plot of Comparative Example 2, Sample 2.
[0053] Figure 7 This is the GPC diagram of sample 1 in Example 1.
[0054] Figure 8 This is the GPC diagram of sample 3 in Example 2. Detailed Implementation
[0055] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used that do not specify the manufacturer are all commercially available products. Unless otherwise specified, all reagents used in the embodiments can be purchased from the market.
[0056] The pencil hardness test method is as follows: Use a pencil hardness tester according to GB / T 6739-2022 to test the coating's pencil hardness. The load is 1000±50g, and the pencil tip is at a 45° angle to the coating surface. Slide the bottom of the pencil hardness tester across the coating at a uniform speed of 1 cm / s for a distance of 2-3 cm. If no defects appear, repeat the test with a pencil of higher hardness until a defect of at least 6 mm appears. If defects have appeared, reduce the pencil hardness and repeat the test until no more defects appear. The pencil hardness of the coating is expressed as the hardness of the hardest pencil that did not cause defects in the paint film.
[0057] Example 1
[0058] (1) In a dry fume hood, 30 g of dichloromethane solvent, 0.1 mol (20.73 g) of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, 0.1 mol (19.83 g) of phenyltrimethoxysilane, and 0.1 mol (24.84 g) of 3-(isobutenoyloxy)propyltrimethoxysilane were added to a 250 mL three-necked flask equipped with reflux, stirring, and temperature control. After mixing thoroughly, 0.6 mol (10.8 g) of deionized water was added, and the mixture was stirred and heated to 35 °C for 24 h. Then, 0.05 mol (5.21 g) of methoxytrimethylsilane end-capping agent was added to a four-necked flask for 24 h. After the reaction was completed, the solvent was removed by rotary evaporation at 40–55 °C to obtain a ladder-shaped tertiary amine polysiloxane resin (sample 1). FTIR, TG, XRD, and GPC tests were performed on sample 1. FTIR spectrum of sample 1 (attached). Figure 1 3, LLPa without K2CO3 (48h): at 1000 – 1150 cm -1 The structure belongs to the Si-O-Si chemical bond. Due to its unique trapezoidal structure, this point splits into two sharp peaks. Highly symmetrical cage-like POSS-type polysiloxanes exhibit this characteristic at 1000–1150 cm⁻¹. -1 The split at this point, forming a sharp peak, confirms that sample 1 has a trapezoidal structure. Due to the short reaction time, it reaches 3500 cm⁻¹. -1 Unreacted Si-OH peaks were observed. TG spectrum of sample 1 (attached). Figure 2 The trapezoidal POSS type exhibits only one cooling plateau between 300 and 400℃, while the cage-like type has two cooling plateaus at 100–200℃ and 300–400℃, further confirming that sample 1 is trapezoidal. The XRD pattern of sample 1 is attached. Figure 4Two broad peaks, one large and one small, exist at 20 ppm and 5 ppm, respectively, corresponding to the distance between the two Si-O-Si segments of the trapezoidal polysiloxane and the distance between the trapezoidal polysiloxane monomers. This is compared with the spectrum of cage-like POSS-type polysiloxanes (see attached). Figure 3 There are obvious differences.
[0059] (2) The ladder-shaped tertiary amine polysiloxane resin obtained in step (1) is mixed with trimethylolpropane triacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. 1 g of the UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin is taken, and 0.1 g of the photoinitiator 4-acryloyloxybenzophenone is dissolved in 0.3 g of butyl acetate. After the three are mixed evenly, they are coated on tinplate with a thickness of 30-40 µm. The coating is placed in an oven at 60 °C. After the solvent evaporates, UV curing is performed using a UV curing machine with a wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin coating. The coating is tested for pencil hardness. The thickness is 27.2-33.5 µm, and the hardness is 5H-6H.
[0060] Example 2
[0061] The preparation was repeated according to step (1), with the total reaction time increased from 48 h to 96 h, and the capping agent was added after 48 h of reaction. After the reaction, the product was rotary evaporated at 40–55 °C to remove the solvent, yielding ladder-shaped tertiary amine polysiloxane resin (sample 3). Sample 3 was subjected to FTIR, TG, XRD, GPC, and other analytical methods. 29 Si NMR test. FTIR spectrum of sample 3 (attached) Figure 1 4, LLPa without K2CO3 96h): at 1000 – 1150 cm -1 The structure belongs to the Si-O-Si chemical bond. Due to its unique trapezoidal structure, this point splits into two sharp peaks. Highly symmetrical cage-like POSS-type polysiloxanes exhibit this characteristic at 1000–1150 cm⁻¹. -1 The split at this point, forming a sharp peak, confirms that sample 3 has a trapezoidal structure. Due to the extended reaction time, it reaches a peak at 3500 cm⁻¹. -1 No unreacted Si-OH peaks were observed. (TG spectrum of sample 3 is attached.) Figure 2 The trapezoidal POSS type exhibits only one cooling plateau between 300 and 400℃, while the cage-like type has two cooling plateaus at 100-200℃ and 300-400℃, further confirming that sample 3 is trapezoidal. The XRD pattern of sample 3 is attached. Figure 4Two broad peaks, one large and one small, exist at 20 ppm and 5 ppm, respectively, corresponding to the distance between the two Si-O-Si segments of the trapezoidal polysiloxane and the distance between the trapezoidal polysiloxane monomers. This is compared with the spectrum of cage-like POSS-type polysiloxanes (see attached). Figure 3 There is a significant difference. Sample 3 29 Si NMR spectrum (with appendix) Figure 5 The presence of a high-intensity T3 peak at -68 ppm indicates that the peak is a Si peak in (SiO)3SiR connected to three silicon-oxygen bonds, proving that all three alkoxy groups of the silane coupling agent are condensed, thus synthesizing a ladder-shaped polysiloxane.
[0062] The obtained ladder-shaped tertiary amine polysiloxane resin was mixed with trimethylolpropane triacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. 1 g of the UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin was taken, and 0.1 g of the photoinitiator 4-acryloyloxybenzophenone was dissolved in 0.3 g of butyl acetate. After the three were mixed evenly, the mixture was coated onto tinplate to a thickness of 30–40 µm. The coating was placed in an oven at 60 °C, and after the solvent evaporated, it was cured using a UV curing machine with a wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin coating. The coating was tested for pencil hardness. The thickness was 27.4–33.2 µm, and the hardness was 6H–7H.
[0063] Comparative Example 1
[0064] Take 1 g of trapezoidal tertiary amine polysiloxane resin (sample 1), without mixing it with trimethylolpropane triacrylate. Dissolve 0.1 g of photoinitiator 4-acryloyloxybenzophenone in 0.3 g of butyl acetate. Mix the three components thoroughly and coat them onto tinplate to a thickness of 30–40 µm. Place the coating in a 60 °C oven and allow the solvent to evaporate. Then, use a UV curing machine with a UV wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-cured trapezoidal tertiary amine polysiloxane resin coating. Perform a pencil hardness test on the coating. The thickness is 28.2–32.0 µm, and the hardness is 3H–4H.
[0065] Comparative Example 2
[0066] Following step (1), the reaction was repeated. During the raw material addition stage, 1000 ppm of anhydrous potassium carbonate was added to the reaction system as a catalyst. After the reaction, the mixture was washed with deionized water until the pH was neutral. The lower layer was separated, and a small amount of residual water was removed using anhydrous magnesium sulfate. The mixture was then filtered, and the filtrate was evaporated at 40–55 °C to remove the solvent, yielding the ladder-shaped tertiary amine polysiloxane resin synthesized with the added catalyst (sample 2). FTIR, TG, XRD, and GPC tests were performed on sample 2. FTIR spectrum of sample 2 (attached) Figure 1 2): at 1000 – 1150 cm -1 The structure belongs to the Si-O-Si chemical bond. Due to its unique trapezoidal structure, it splits into two sharp peaks at this point. This is consistent with the highly symmetrical cage-like POSS-type polysiloxane (see appendix). Figure 1 1) in 1000 – 1150 cm -1 The split at 3500 cm⁻¹ results in a sharp peak, confirming that sample 2 has a trapezoidal structure. Unlike sample 1, the addition of K₂CO₃ catalyst accelerated the reaction, resulting in a peak at 3500 cm⁻¹. -1 No unreacted Si-OH peaks were observed. (TG spectrum of sample 2 is attached.) Figure 2 The trapezoidal POSS-type sample 2 exhibits only one cooling plateau between 300 and 400 °C, while the cage-like POSS-type sample has two cooling plateaus at 100–200 °C and 300–400 °C, further confirming that sample 2 is trapezoidal. The XRD pattern of sample 2 is attached. Figure 4 Two broad peaks, one large and one small, exist at 20 ppm and 5 ppm, respectively, corresponding to the distance between the two Si-O-Si segments of the trapezoidal polysiloxane and the distance between the trapezoidal polysiloxane monomers. This is compared with the spectrum of cage-like POSS-type polysiloxanes (see attached). Figure 3 There are obvious differences.
[0067] The resulting ladder-shaped tertiary amine polysiloxane resin, synthesized with the added catalyst, was physically mixed with trimethylolpropane triacrylate at room temperature in a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. 1 g of the UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin was taken, and 0.1 g of the photoinitiator 4-acryloyloxybenzophenone was dissolved in 0.3 g of butyl acetate. After the mixture was thoroughly mixed, it was coated onto tinplate to a thickness of 30–40 µm. The coating was then placed in an oven at 60 °C. After the solvent evaporated, UV curing was performed using a UV curing machine with a wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s, resulting in a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin coating. The coating was tested for pencil hardness. The thickness was 27.8–31.2 µm, and the hardness was 6H–7H.
[0068] Example 3
[0069] (1) In a dry fume hood, 30 g of dichloromethane solvent, 0.1 mol (23.54 g) of (N,N-diethyl-3-aminopropyl)trimethoxysilane, 0.1 mol (24.03 g) of phenyltriethoxysilane, and 0.1 mol (29.04 g) of 3-(methacryloyloxy)propyltriethoxysilane were added to a 250 mL three-necked flask equipped with reflux, stirring, and temperature control. After mixing thoroughly, 0.6 mol (10.8 g) of deionized water was added, and the mixture was stirred and heated to 35 °C for 24 h. Then, 0.05 mol (5.92 g) of methoxytriethylsilane end-capping agent was added to a four-necked flask for 24 h. After the reaction was completed, the solvent was removed by rotary evaporation at 40–55 °C to obtain a ladder-shaped tertiary amine polysiloxane resin.
[0070] (2) The ladder-shaped tertiary amine polysiloxane resin obtained in step (1) is mixed with pentaerythritol tetraacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of the UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin, dissolve 0.1 g of the photoinitiator 4-methacryloyloxybenzophenone in 0.3 g of butyl acetate, mix the three evenly, and coat it on tinplate with a thickness of 30-40 µm. Place it in an oven at 60 ℃, and after the solvent evaporates, use a UV curing machine for UV curing. The UV wavelength is 365 nm, the power is 2 kW, and the irradiation time is 40 s to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin coating. The coating is tested for pencil hardness. The thickness is 29.2-31.5 µm, and the hardness is 5H-6H.
[0071] Example 4
[0072] The product was prepared again according to step (1) in Example 3, with the total reaction time increased from 48 h to 96 h, and the capping agent was added after 48 h of reaction. After the reaction, the product was removed by rotary evaporation at 40-55 °C to obtain a ladder-shaped tertiary amine polysiloxane resin. The obtained ladder-shaped tertiary amine polysiloxane resin was mixed with pentaerythritol tetraacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin, dissolve 0.1 g of photoinitiator 4-methacryloyloxybenzophenone in 0.3 g of butyl acetate, mix the three ingredients thoroughly, and coat the mixture onto tinplate to a thickness of 30–40 µm. Place the coating in a 60 °C oven and allow the solvent to evaporate. Then, use a UV curing machine with a UV wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin coating. Perform a pencil hardness test on the coating. The thickness is 30.8–31.9 µm, and the hardness is 6H–7H.
[0073] Comparative Example 3
[0074] Take only 1 g of the ladder-shaped tertiary amine polysiloxane resin obtained in step (1) of Example 3, without mixing it with pentaerythritol tetraacrylate. Dissolve 0.1 g of the photoinitiator 4-methacryloyloxybenzophenone in 0.3 g of butyl acetate. Mix the three ingredients evenly and coat them onto tinplate with a thickness of 30-40 µm. Place the coating in an oven at 60 °C and allow the solvent to evaporate. Then, use a UV curing machine to cure the coating. The UV wavelength is 365 nm, the power is 2 kW, and the irradiation time is 40 s. The resulting UV-cured ladder-shaped tertiary amine polysiloxane resin coating is then obtained. The coating is tested for pencil hardness. The thickness is 28.6-33.1 µm, and the hardness is 3H-4H.
[0075] Comparative Example 4
[0076] The reaction was prepared again according to step (1) in Example 3. During the raw material feeding stage, 1000 ppm of anhydrous potassium carbonate was added to the reaction system as a catalyst. After the reaction, the mixture was washed with deionized water until the pH was neutral. The lower layer solution was separated, and a small amount of residual water was removed with anhydrous magnesium sulfate. The mixture was then filtered, and the filtrate was evaporated at 40-55 °C to remove the solvent, thus obtaining the ladder-shaped tertiary amine polysiloxane resin synthesized with the added catalyst. The obtained ladder-shaped tertiary amine polysiloxane resin synthesized with the added catalyst was mixed with pentaerythritol tetraacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin, dissolve 0.1 g of photoinitiator 4-methacryloyloxybenzophenone in 0.3 g of butyl acetate, mix the three ingredients thoroughly, and coat the mixture onto tinplate to a thickness of 30–40 µm. Place the coating in a 60 °C oven and allow the solvent to evaporate. Then, use a UV curing machine with a UV wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin coating. Perform a pencil hardness test on the coating. The thickness is 30.6–32.5 µm, and the hardness is 6H–7H.
[0077] Example 5
[0078] (1) In a dry fume hood, 30 g of dichloromethane solvent, 0.1 mol (24.93 g) of (N,N-dimethyl-3-aminopropyl)triethoxysilane, 0.1 mol (24.03 g) of phenyltriethoxysilane, and 0.1 mol (23.42 g) of 3-acryloyloxypropyltrimethoxysilane were added to a 250 mL three-necked flask equipped with reflux, stirring, and temperature control. After mixing thoroughly, 0.6 mol (10.8 g) of deionized water was added, and the mixture was stirred and heated to 35 °C for 24 h. Then, 0.05 mol (5.92 g) of methoxytriethylsilane end-capping agent was added to a four-necked flask for 24 h. After the reaction was completed, the solvent was removed by rotary evaporation at 40–55 °C to obtain a ladder-shaped tertiary amine polysiloxane resin.
[0079] (2) The ladder-shaped tertiary amine polysiloxane resin obtained in step (1) is mixed with pentaerythritol triacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of the UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin, dissolve 0.1 g of the photoinitiator 4-hydroxyvinyloxybenzophenone methacrylate in 0.3 g of butyl acetate, mix the three evenly, and coat it on tinplate with a thickness of 30-40 µm. Place it in an oven at 60 ℃, and after the solvent evaporates, use a UV curing machine for UV curing. The UV wavelength used is 365 nm, the power is 2 kW, and the irradiation time is 40 s to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin coating. The coating is tested for pencil hardness. The thickness is 29.6-31.1 µm, and the hardness is 4H-6H.
[0080] Example 6
[0081] The product was prepared again according to step (1) in Example 5, with the total reaction time increased from 48 h to 96 h, and the capping agent was added after 48 h of reaction. After the reaction, the product was removed by rotary evaporation at 40-55 °C to obtain a ladder-shaped tertiary amine polysiloxane resin. The obtained ladder-shaped tertiary amine polysiloxane resin was mixed with pentaerythritol triacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin, dissolve 0.1 g of photoinitiator 4-hydroxyvinyloxybenzophenone methacrylate in 0.3 g of butyl acetate, mix the three ingredients thoroughly, and coat the mixture onto tinplate to a thickness of 30–40 µm. Place the coating in a 60 °C oven and allow the solvent to evaporate. Then, use a UV curing machine with a UV wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin coating. Perform a pencil hardness test on the coating. The thickness is 29.8–30.9 µm, and the hardness is 6H–7H.
[0082] Comparative Example 5
[0083] Take only 1 g of the trapezoidal tertiary amine polysiloxane resin obtained in step (1) of Example 5, without mixing it with pentaerythritol triacrylate. Dissolve 0.1 g of the photoinitiator 4-hydroxyvinyloxybenzophenone methacrylate in 0.3 g of butyl acetate. Mix the three ingredients evenly and coat them onto tinplate with a thickness of 30-40 µm. Place the coating in an oven at 60 °C and allow the solvent to evaporate. Then, use a UV curing machine to cure the coating. The UV wavelength is 365 nm, the power is 2 kW, and the irradiation time is 40 s. The resulting UV-cured trapezoidal tertiary amine polysiloxane resin coating is then obtained. The coating is tested for pencil hardness. The thickness is 27.6-33.3 µm, and the hardness is 3H-4H.
[0084] Comparative Example 6
[0085] Following step (1) in Example 5, during the raw material feeding stage, 1000 ppm of anhydrous potassium carbonate was added to the reaction system as a catalyst. After the reaction, the mixture was washed with deionized water until the pH was neutral. The lower layer solution was separated, and a small amount of residual water was removed using anhydrous magnesium sulfate. The mixture was then filtered, and the filtrate was evaporated at 40–55 °C to remove the solvent, yielding the ladder-shaped tertiary amine polysiloxane resin synthesized with the added catalyst. The obtained ladder-shaped tertiary amine polysiloxane resin synthesized with the added catalyst was mixed with pentaerythritol triacrylate at a mass ratio of 1:1 to obtain a UV-curable ladder-shaped tertiary amine polysiloxane polyacrylate resin. Take 1 g of UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin, dissolve 0.1 g of photoinitiator 4-hydroxyvinyloxybenzophenone methacrylate in 0.3 g of butyl acetate, mix the three ingredients thoroughly, and coat the mixture onto tinplate to a thickness of 30–40 µm. Place the coating in a 60 °C oven and allow the solvent to evaporate. Then, use a UV curing machine with a UV wavelength of 365 nm, a power of 2 kW, and an irradiation time of 40 s to obtain a UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin coating. Perform a pencil hardness test on the coating. The thickness is 31.7–32.4 µm, and the hardness is 6H–7H.
[0086] Table 1 shows the molecular weight results for Comparative Example 2 (LLPA), Example 1 (LLPA 48h), and Example 2 (LLPA 96h).
[0087] Table 1
[0088]
[0089] Table 2
[0090]
[0091] Table 3
[0092]
[0093] This invention utilizes a tertiary amine silane coupling agent to provide an alkaline environment for the autocatalytic synthesis of ladder-shaped polysiloxane resins. After the reaction, the tertiary amine silane coupling agent is grafted into the polymer chain, becoming part of the product, thus avoiding the cumbersome steps and product loss associated with subsequent removal using catalysts such as K₂CO₃. As shown in Example 2, after extending the reaction time to 96 h, the hardness of the resulting coating reached the level of Comparative Example 2 (with K₂CO₃ catalyst) (6-7 H). Furthermore, the molecular weight distribution of the ladder-shaped polysiloxanes obtained by this invention is more concentrated (Tables 2 and 3). When the reaction time is 48 h and 96 h, their polydispersity is 1.921 and 1.589, respectively, which is significantly lower than the polydispersity of 10.021 for the ladder-shaped tertiary amine polysiloxanes with K₂CO₃ catalyst (Table 1). This indicates that this method offers superior control over molecular weight compared to traditional methods that add catalysts.
[0094] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A method for autocatalytic synthesis of UV-curable ladder-shaped tertiary amine polysiloxane resin, characterized in that, Includes the following steps: An aminosilane coupling agent containing a tertiary amine group, a phenylsilane coupling agent, an acryloyloxysilane coupling agent, and an organic solvent are mixed evenly, then water is added, and after reacting for a period of time, an end-capping agent is added. After the reaction is completed, the solvent in the product is removed to obtain a UV-curable ladder-shaped tertiary amine polysiloxane resin.
2. The method for autocatalytic synthesis of UV-curable ladder-shaped tertiary amine polysiloxane resin according to claim 1, characterized in that, The aminosilane coupling agent containing a tertiary amine group is at least one of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, and (N,N-dimethyl-3-aminopropyl)triethoxysilane. The phenylsilane coupling agent is at least one of phenyltrimethoxysilane and phenyltriethoxysilane; The acryloyloxysilane coupling agent is at least one of 3-(isobutenoyloxy)propyltrimethoxysilane, 3-(methacryloyloxy)propyltriethoxysilane, and 3-acryloyloxypropyltrimethoxysilane. The organic solvent is at least one of dichloromethane and tetrahydrofuran; The capping agent is at least one of trimethylethoxysilane and methoxytrimethylsilane.
3. The method for autocatalytic synthesis of UV-curable ladder-shaped tertiary amine polysiloxane resin according to claim 1, characterized in that, The molar ratio of the aminosilane coupling agent containing tertiary amine groups, the phenylsilane coupling agent, the acryloyloxysilane coupling agent, and the capping agent is 0.5~1:1:1:0.5~1; The molar ratio of the phenylsilane coupling agent to water is 1:5~9; The ratio of solvent to silane coupling agent is 15~50 g: 0.1~0.5 mol; The reaction temperature is 30~40 ℃, and the reaction time is 48~96 h; The capping agent is added at 1 / 3 to 1 / 2 of the reaction time.
4. A UV-curable ladder-shaped tertiary amine polysiloxane resin, characterized in that, It is prepared by the method described in any one of claims 1 to 3.
5. A method for preparing UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin using the UV-curable ladder-shaped polysiloxane resin according to claim 4, characterized in that, Includes the following steps: UV-curable trapezoidal tertiary amine polysiloxane resin is mixed with polyacrylate to obtain UV-curable trapezoidal tertiary amine polysiloxane polyacrylate resin.
6. The method for preparing UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin according to claim 5, characterized in that, The polyacrylate is at least one of trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and pentaerythritol triacrylate; The mass ratio of the polyacrylate to the UV-cured trapezoidal tertiary amine polysiloxane resin is 0.5~2:0.5~4.
7. A UV-curable ladder-shaped tertiary amine polysiloxane polyacrylic acid resin, characterized in that, Prepared by the method described in claim 5 or 6.
8. The use of the UV-curable trapezoidal tertiary amine polysiloxane polyacrylic acid resin according to claim 7 in the preparation of coatings, coating materials, film-forming compositions or protective coatings.
9. The application according to claim 8, characterized in that, The coating, coating material, film-forming composition or protective coating comprises the following components: ladder-shaped tertiary amine polysiloxane polyacrylic resin, photoinitiator and organic solvent; The amount of photoinitiator used is 7%-10wt% of the mass of the ladder-shaped tertiary amine polysiloxane polyacrylic acid resin.
10. The application according to claim 9, characterized in that, The initiator is a hydrogen-abstracting photoinitiator; The organic solvent is at least one of butyl acetate, propyl acetate, and ethyl acetate; The mass ratio of the organic solvent to the photoinitiator is 2~3:0.7~1.