Photo-curable silicon-based ceramic precursor as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photocuring materials, silicon-based ceramic precursors and silicon-based ceramics, and particularly relates to a photocurable silicon-based ceramic precursor as well as a preparation method and application thereof. The photo-curable silicon-based ceramic precursor provided by the invention can be used as silicon-based ceramic precursor resin, the ceramization yield of a cured product is high, and the photo-curable silicon-based ceramic precursor shows huge application prospects in the fields of preparation of resin films / coatings, organic and inorganic hybrid material films / coatings, ceramic films / coatings, ceramic fibers, ceramic-based composite materials, preparation of ceramic parts through 3D printing and the like.

Description

[0001] This application is a divisional application of the application with the application number 2022104127326, the application date of April 19, 2022, and the invention title of "A Photocurable Silicon-Based Ceramic Precursor and Its Preparation Method and Application".

[0002] The present invention belongs to the technical fields of photocurable materials, silicon-based ceramic precursors and silicon-based ceramics, and specifically relates to a photocurable silicon-based ceramic precursor and its preparation method and application. Background Art

[0003] Photosensitive silicon-based ceramic precursors show great application prospects in the fields of preparing ceramic coatings, ceramic matrix composites, stereolithography, ceramic microelectromechanical systems, etc. Among them, using stereolithography technology, that is, photocuring 3D printing technology, to prepare complex-structure ceramic parts is a ceramic part preparation technology with great development potential. Compared with photocurable ceramic slurries, the photocurable silicon-based ceramic precursor polymers used for 3D printing have several advantages. Firstly, the silicon-based ceramic precursor can be in a liquid phase, without agglomeration and light scattering effects. Secondly, the ceramic composition can be regulated through the structure and composition of the precursor, and it is easy to print more precise ceramic parts with less impurities.

[0004] Currently, there is a serious lack of commercial products of various photocurable silicon-based ceramic precursors. The only commercially available photocurable polysiloxane with the brand name TEGO RC 711 from Evonik Industries in Germany has a ceramic yield of only 7.4 wt% (1000 °C, N2) after photocuring. In current research, the common method for preparing photocurable polysiloxanes is to obtain photocurable polysiloxanes by hydrolyzing and condensing silane coupling agents containing photosensitive groups (such as KH-570). The content of photosensitive groups and the viscosity of the products obtained by this method are not easy to control, and the ceramic yield is relatively low. The highest reported value is only 51.2 wt%. For polycarbosilane, polysilazane, polysilaboronitride and other silicon-based ceramic precursors, there is less research on photocuring and no commercial products. Therefore, the development of photocurable silicon-based ceramic precursors has important application and commercial value.

[0005] In the field of silicon-based ceramic precursor products, there are currently several commercial products in China. For example, the polysiloxane-based ceramic precursor, polysilazane-based ceramic precursor, polycarbosilane-based ceramic precursor, or polyborosilazane-based ceramic precursor of our unit. For example, polysiloxane-based ceramic precursor (such as grade KH-PSO-1), liquid polycarbosilane (such as grade KH-VHPCS-1, KH-AHPCS-1); polysilazane (such as grade KH-PSN1, KH-PSN2); polyborosilazane (such as grade KH-PSNB), etc. The above-mentioned liquid polycarbosilane, polysilazane, and polyborosilazane are all products applicable to thermal curing in the prior art and have been applied in high-tech fields such as aerospace. However, the above products are designed and synthesized for the molecular structure required by the thermal curing process, and their photocuring characteristics cannot meet typical application requirements. Summary of the Invention

[0006] To overcome the deficiencies in the prior art, the present invention provides a silicon-based ceramic precursor that can be photocured at room temperature, its preparation method, and its application, with a novel structure.

[0007] The present invention provides the following technical solutions:

[0008] A photocurable silicon-based ceramic precursor having a chain segment structure as shown in Formula M or N:

[0009]

[0010] Wherein, R and R' are the same or different and are independently selected from H, unsubstituted, or the following groups optionally substituted by one, two, or more Ra: C 1-20 alkyl or C 1-20 alkoxy; Ra is selected from hydroxyl, halogen, amino, or C 1-20 alkyl;

[0011] Y is the same or different and is independently selected from unsubstituted, or the following groups optionally substituted by one, two, or more Rb: C 2-10 alkenyl or C 2-10 alkynyl;

[0012] Rb is selected from hydroxyl, halogen, amino, or C 1-20 alkyl;

[0013] X is the same or different and is independently selected from a photosensitive reaction group Rg, and the photosensitive reaction group Rg is a group that undergoes a polymerization reaction under the conditions of light irradiation and the presence of a photoinitiator;

[0014] The photosensitive reaction group Rg is a carbonyl group, carboxyl group, peroxide group, and group containing an unsaturated bond, and the photosensitive reaction group is preferably an acrylate group, vinyl ether group, or epoxy group;

[0015] x = 0.01 to 0.9, y = 0.00 to 0.9, z = 0.00 to 0.9, x + y + z = 0.01 to 0.9.

[0016] Preferably, x is 0.05 to 0.50, y is 0 to 0.5, z is 0 to 0.5; x + y + z = 0.1 to 0.8.

[0017] For example, x is 0.1, 0.2, 0.4; y is 0, 0.1, 0.5; z is 0, 0.1, 0.3.

[0018] It should be clear that although the segments of the photocurable silicon-based ceramic precursor of the present invention are as shown in M or N, it does not mean that the segments represented by x, y, z and (1 - x - y - z) in its structure are arranged in this order. Due to factors such as chemical steric hindrance and the activity of reaction sites, X and Y can be substituted at any position on the main chain.

[0019] According to an embodiment of the present invention, the R is H, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxy-substituted C 1-4 alkyl or halo C 1-4 alkyl, preferably H or C 1-4 alkyl.

[0020] According to an embodiment of the present invention, the R' is H, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxy-substituted C 1-4 alkyl or halo C 1-4 alkyl, preferably H or C 1-4 alkyl.

[0021] According to an embodiment of the present invention, the weight-average molecular weight M w of the photocurable silicon-based ceramic precursor is 600 - 100000, and the number-average molecular weight M n is 300 - 50000. For example, the weight-average molecular weight M w of the photocurable silicon-based ceramic precursor is 1000 - 40000, and the number-average molecular weight M n is 500 - 10000.

[0022] According to an embodiment of the present invention, the Y is CH2=CH-, CH2=CHCH2-, CH2=C(CH3)-, CH3CH=CH-, HC≡C-, HC≡C-CH2- or cyclopropyl-(CH2)2CH-, preferably CH2=CH- or CH2=CHCH2-.

[0023] According to an embodiment of the present invention, the acrylate group is selected from -A-OOC-C(R1)=CH2, wherein A is selected from absent or -O(CH2) a -, when A is absent, O in -OOC- of -OOC-C(R1)=CH2 is connected to Si, and when present, O in -O(CH2) a - is connected to Si, a is an integer from 1 to 6 (for example, an integer from 2 to 4), and R1 is selected from H, C 1-6 alkyl; more specifically, the acrylate group is selected from -OOC-CH=CH2, -OOC-C(CH3)=CH2, -O(CH2)2OOC-CH=CH2, -O(CH2)3OOC-CH=CH2, -O(CH2)2OOC-C(CH3)=CH2, -O(CH2)3OOC-C(CH3)=CH2, etc.

[0024] According to an embodiment of the present invention, the vinyl ether group is selected from the group shown in formula (2):

[0025] -O-(CH2) m1 -O-(CH2) m2 -C(R2)=CH(R3) Formula (2)

[0026] wherein, m1 is an integer from 1 to 6 (for example, an integer from 1 to 4), m2 is an integer from 0 to 6 (for example, 0 or 1), R2 is selected from H, methyl or ethyl, and R3 is selected from H or C 1-6 alkyl.

[0027] More specifically, the vinyl ether group is selected from -OCH2-O-CH=CH2, -O(CH2)2-O-CH=CH2, -OCH2-O-CH=CH-CH3, -OCH2-O-CH=CH-C2H5, -OCH2-O-CH=CH-C3H7, -O(CH2)3-O-CH=CH2, -O(CH2)4-O-CH=CH2, -O(CH2)5-O-CH=CH2, -O(CH2)6-O-CH=CH2, -OCH2-O-CH2-CH=CH2, -O(CH2)2-O-CH2-CH=CH2, -O(CH2)3-O-CH2-CH=CH2, -O(CH2)4-O-CH2-CH=CH2, -O(CH2)5-O-CH2-CH=CH2, -O(CH2)6-O-CH2-CH=CH2, etc.

[0028] According to an embodiment of the present invention, the epoxy group is selected from -O(CH2) n1 -R4, wherein, n1 is an integer from 1 to 6, and R4 is selected from substituted or unsubstituted C 2-12Epoxyalkyl group, substituted or unsubstituted epoxy C 3-12 Cycloalkyl group, when substituted, the substituent is C 1-6 Alkyl group (e.g., C 1-3 Alkyl group). For example, R4 is selected from substituted or unsubstituted C 2-5 Epoxyalkyl group, substituted or unsubstituted epoxy C 3-8 Cycloalkyl group, the substituent is 1-6 Alkyl group (e.g., C 1-3 Alkyl group). Again, for example, R4 is selected from substituted or unsubstituted epoxyethyl group, substituted or unsubstituted epoxypropyl group, substituted or unsubstituted epoxybutyl group, substituted or unsubstituted epoxycyclobutyl group, substituted or unsubstituted epoxycyclopentyl group, substituted or unsubstituted epoxycyclohexyl group, and the substituent is C 1-3 Alkyl group. Exemplarily, R4 is selected from ● indicates the connection site.

[0029] According to an exemplary embodiment of the present invention, the photocurable silicon-based ceramic precursor has a structure shown in any one of the following formulas M1 to M7 and N1 to N6:

[0030]

[0031]

[0032]

[0033]

[0034] According to an embodiment of the present invention, the photocurable silicon-based ceramic precursor has a TGA ceramic yield of 40 - 90% at 1000 °C, for example, 45 - 85%.

[0035] According to an embodiment of the present invention, the TGA ceramic yield of the photocurable silicon-based ceramic precursor after crosslinking and curing under the action of a catalyst is 50 - 85.0%.

[0036] According to an embodiment of the present invention, when the photocurable silicon-based ceramic precursor is sealed and stored at room temperature (0 - 40 °C) for 1 - 3 months, its viscosity change is less than 10%.

[0037] The present invention also provides a preparation method of the above-mentioned photocurable silicon-based ceramic precursor, including the following steps: using a silicon-based ceramic precursor resin containing a silicon-hydrogen bond and a hydroxyl-containing photosensitive monomer Rg-H as raw materials, and carrying out a catalytic reaction in the presence of a dehydrogenation coupling catalyst;

[0038] In Rg-H, Rg has the definition described above.

[0039] According to an embodiment of the present invention, the silicon-based ceramic precursor resin containing a silicon-hydrogen bond is selected from polysiloxanes (such as KH-PSO-1, KH-PSO-2, KH-PSO-3 or KH-PSO-4), liquid polycarbosilanes (such as grades KH-VHPCS-1, KH-AHPCS-1, KH-AHPCS-2, KH-VHPCS-2, KH-HPCS-1); polysilazanes (such as grades KH-PSN1, KH-PSN2); polyborosilazanes (such as grade KH-PSNB), etc.

[0040] Preferably, the liquid silicon-based ceramic precursor resin containing a silicon-hydrogen bond is polysiloxane (KH-PSO-1), polycarbosilane (KH-VHPCS-1, KH-AHPCS-1, KH-AHPCS-2, KH-VHPCS-2).

[0041] According to an embodiment of the present invention, the photosensitive monomer Rg-H containing -OH is an acrylate monomer containing -OH, a vinyl ether monomer containing -OH or an epoxy monomer containing -OH.

[0042] According to an embodiment of the present invention, the structural formula of the acrylate monomer containing -OH is H-A-OOC-C(R1)=CH2, where A and R1 have the definitions as described above;

[0043] Preferably, the acrylate monomer containing -OH is selected from HOOC-CH=CH2, HOOC-C(CH3)=CH2, HO(CH2)2OOC-CH=CH2, HO(CH2)3OOC-CH=CH, HO(CH2)2OOC-C(CH3)=CH2 or HO(CH2)3OOC-C(CH3)=CH2.

[0044] According to an embodiment of the present invention, the structural formula of the vinyl ether monomer containing -OH is HO(CH2) m1 -O-(CH2) m2 -C(R2)=CH(R3), where m1, m2, R2 and R3 have the definitions as described above;

[0045] Preferably, the -OH-containing vinyl ether monomer is HOCH2-O-CH=CH2, HO(CH2)2-O-CH=CH2, HO(CH2)3-O-CH=CH2, HO(CH2)4-O-CH=CH2, HO(CH2)5-O-CH=CH2, HO(CH2)6-O-CH=CH2, HOCH2-O-CH2-CH=CH2, HO(CH2)2-O-CH2-CH=CH2, HO(CH2)3-O-CH2-CH=CH2, HO(CH2)4-O-CH2-CH=CH2, HO(CH2)5-O-CH2-CH=CH2 or HO(CH2)6-O-CH2-CH=CH2.

[0046] According to an embodiment of the present invention, the structural formula of the -OH-containing epoxy monomer is H-O(CH2) n1 -R4, where n1 and R4 have the definitions as described above.

[0047] Preferably, the -OH-containing epoxy monomer is selected from the following structures:

[0048]

[0049] According to an embodiment of the present invention, the solvent is selected from benzene-containing solvents, ether solvents, low-boiling alkane solvents, etc.

[0050] For example, the benzene-containing solvent is one, two or more of toluene, xylene, mesitylene, etc.; preferably, it is toluene.

[0051] For example, the ether solvent is one, two or more of diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, methyl tert-butyl ether, methyl tert-amyl ether, cyclopentyl methyl ether; preferably, it is one, two or more of tetrahydrofuran, 2-methyltetrahydrofuran, methyl tert-butyl ether, methyl tert-amyl ether.

[0052] For example, the low-boiling alkane solvent is one, two or more of pentane, cyclopentane, hexane and petroleum ether (30 - 120 °C); preferably, it is a mixture of hexane and petroleum ether (60 - 90 °C).

[0053] According to an embodiment of the present invention, the dehydrogenative coupling catalyst is selected from transition metal catalysts, alkali metal catalysts, metal-free organic catalysts, etc.

[0054] For example, the transition metal catalyst is selected from Group 4 metallocene complex catalysts, Cp2MR2 (M = Ti, Zr, Hf; R = alkyl, Ph, H; Cp = η 5-cyclopentadienyl or its alkyl-substituted derivatives), or Cp2MX2 / n-BuLi (M = Ti, Zr, Hf; X = Cl, OAr), Ti IV , Mn II , Re IV , Fe II , Ru II , Rh II , Ir II , Ni II , Cu II , Au I , Pt II and Zn II and other homogeneous metal complexes with multiple valence states; lanthanide metallocenes; one, two or more of palladium chloride and nickel chloride; preferably, one, two or three of Cp2Ti(CH3)2, palladium chloride and nickel chloride.

[0055] For example, the alkali metal catalyst is one, two or more of fluoride salt KF, strong bases NaOH, KOH, alkali metal salts [MN(SiMe3)2] (M = Li, Na, K), sodium tris(sec-butyl)borohydride, potassium tris(sec-butyl)borohydride, lithium tris(sec-butyl)borohydride; preferably, one, two or more of NaOH, [NaN(SiMe3)2], sodium tris(sec-butyl)borohydride.

[0056] For example, the metal-free organic catalyst is one, two or more of tris(pentafluorophenyl)borane, N-heterocyclic carbenes (NHCs), N,N-diethylhydroxylamine, tetrabutylammonium fluoride; preferably, at least one of N,N-diethylhydroxylamine and tris(pentafluorophenyl)borane.

[0057] According to an embodiment of the present invention, the molar ratio of Si-H in the silicon-based ceramic precursor resin containing a silicon-hydrogen bond to -OH in the photosensitive monomer containing -OH is 1:(0.01 - 1), preferably 1:(0.1 - 1).

[0058] According to an embodiment of the present invention, the molar ratio of the dehydrogenative coupling catalyst to the photosensitive monomer containing -OH is 1:(1 - 1000000), preferably 1:(0.1 - 1000).

[0059] According to an embodiment of the present invention, the volume ratio of the silicon-based ceramic precursor resin containing a silicon-hydrogen bond to the solvent is 1:1 - 1:100.

[0060] According to an embodiment of the present invention, the temperature of the reaction is 15°C - 90°C, preferably, the temperature of the reaction is 35°C - 70°C; the reaction time is 3h - 36h, preferably, the reaction time is 6h - 24h.

[0061] According to an embodiment of the present invention, the above preparation method may further include post-treatment: removing the dehydrogenative coupling catalyst, distilling the obtained photocurable silicon-based ceramic precursor to obtain a final product.

[0062] Preferably, a method for preparing a photocurable silicon-based ceramic precursor, specifically:

[0063] (1) Under stirring, a dehydrogenative coupling catalyst is added to a silicon-based ceramic precursor resin containing a silicon-hydrogen bond and a photosensitive monomer containing a hydroxyl group, and the catalytic reaction is carried out under suitable solvent and temperature conditions.

[0064] (2) An absorbent for the dehydrogenative coupling catalyst is added to remove the catalyst, and through post-treatments such as filtration, centrifugation, or phase separation by adding water and low-boiling alkanes and distillation, a purified final product, the photocurable silicon-based ceramic precursor, is obtained.

[0065] The present invention also provides an application of the above photocurable silicon-based ceramic precursor, which is used as a photocurable resin material or a photocurable ceramic precursor composition, etc.

[0066] The present invention also provides a photocurable resin material, and the raw materials of the photocurable resin material include the above photocurable silicon-based ceramic precursor, a photoinitiator, and a stabilizer.

[0067] According to an embodiment of the present invention, by mass percentage, the raw materials of the photocurable resin material include 95-99.9% of the above photocurable silicon-based ceramic precursor, 0.1-5% of the photoinitiator, and 0-1% of the stabilizer.

[0068] Preferably, by mass percentage, the raw materials of the photocurable material include 98-99.5% of the above photocurable silicon-based ceramic precursor, 0.5-2% of the photoinitiator, and 0-0.2% of the stabilizer.

[0069] According to an embodiment of the present invention, the photoinitiator is a radical photoinitiator and / or a cationic photoinitiator.

[0070] Preferably, a carbosilane photosensitive monomer containing an acrylate group uses a radical photoinitiator, a carbosilane photosensitive monomer containing an epoxy group uses a cationic photoinitiator, and a carbosilane photosensitive monomer containing a vinyl ether group uses a cationic photoinitiator and / or a radical photoinitiator.

[0071] According to an embodiment of the present invention, the cationic photoinitiator includes iodonium salts and sulfonium salts, such as at least one of diaryliodonium hexafluorophosphate, diaryliodonium hexafluoroarsenate, diaryliodonium hexafluoroantimonate, triarylsulfonium hexafluorophosphate, triarylsulfonium hexafluoroarsenate, or triarylsulfonium hexafluoroantimonate, etc. Preferably, it is triarylsulfonium hexafluoroantimonate.

[0072] According to an embodiment of the present invention, the free radical photoinitiator includes a free radical initiator that can initiate the polymerization of all unsaturated monomers containing carbon-carbon double bonds. For example, it is selected from phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, benzophenone, benzoin dimethyl ether, benzophenone chloride, 4-benzoyl-4'-2-2-hydroxy-2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylbenzophenone or 2,4-diethylthioxanthone, etc., or a mixture of two or more of them. Preferably, it is benzoin dimethyl ether or 1-hydroxycyclohexylbenzophenone.

[0073] According to an embodiment of the present invention, the stabilizer can be a free radical inhibitor, such as 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, dibutylhydroxytoluene (BHT) or 2,2,6,6-tetramethylpiperidine oxide (TEMPO), etc.; the stabilizer can also include an ultraviolet absorber, such as hexamethylphosphoramide (HMPA), 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone or 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, etc.

[0074] The present invention also provides a photocuring method for the above photocurable resin material, including the following steps:

[0075] Add a photoinitiator to the above photocurable silicon-based ceramic precursor and cure it under light irradiation.

[0076] According to an embodiment of the present invention, ultraviolet light irradiation is used, and the wavelength of the ultraviolet light is 254-405 nm; the irradiation time is 1-60 min.

[0077] The present invention also provides a photocurable ceramic precursor composition, which includes: the above photocurable silicon-based ceramic precursor, a photoinitiator, an optionally present organic oligomer, an optionally present stabilizer, and an optionally present inorganic filler.

[0078] The present invention also provides a preparation method for the above photocurable ceramic precursor composition, the method includes: adding a photoinitiator to the above photocurable silicon-based ceramic precursor, optionally adding or not adding an organic oligomer, optionally adding or not adding a stabilizer, optionally adding or not adding an inorganic filler, and curing it under light irradiation to prepare a photocurable ceramic precursor composition;

[0079] According to an embodiment of the present invention, the organic oligomer refers to a photosensitive resin with a relatively low molecular weight, having groups that can undergo photocuring reactions, such as various unsaturated double bonds or epoxy groups. For example, it is selected from one, two, or more of various acrylic resins, epoxy resins, and vinyl ether resins.

[0080] According to an embodiment of the present invention, the inorganic filler includes but is not limited to typical oxide or non-oxide ceramic materials, such as silica, alumina, zirconia, mullite, silicon carbide, zirconium carbide, boron nitride, silicon nitride, zirconium boride, zirconium silicide, titanium oxide, etc.

[0081] According to an embodiment of the present invention, the preparation method of the above-mentioned photocurable ceramic precursor material composition specifically includes: adding a photoinitiator, an organic oligomer, a stabilizer, and optionally an inorganic filler to the above-mentioned photocurable silicon-based ceramic precursor, and curing under light irradiation to prepare a photocurable ceramic precursor composition.

[0082] According to an embodiment of the present invention, the light irradiation is ultraviolet light irradiation, the wavelength of the ultraviolet light is 172 - 470 nm, for example, 254 - 405 nm; the light irradiation time is 1 - 60 min.

[0083] According to an embodiment of the present invention, the preparation method of the above-mentioned photocurable ceramic precursor composition specifically includes:

[0084] (S1) Using an α-hydroxyalkyl phenyl ketone radical photoinitiator such as 2-hydroxy-2-methyl-1-phenylpropanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, or 1-hydroxycyclohexyl phenyl ketone as the initiator for the acrylate group-containing photocurable silicon-based ceramic precursor; or using diaryliodonium salts or triarylsulfonium salts as the initiator for the epoxy group- and vinyl ether group-containing photocurable silicon-based ceramic precursor;

[0085] (S2) Using ultraviolet light irradiation to initiate a photopolymerization reaction to prepare a photocurable ceramic precursor composition.

[0086] Among them, the curing degree of the photocurable ceramic precursor can be characterized by methods such as infrared, photocurable rheology, DSC, etc.

[0087] This precursor system has the characteristic of being transformed into a silicon-based non-oxide ceramic with a relatively high yield at high temperatures, and the viscosity of this precursor is relatively low (less than 500 cp), which is suitable for 3D printing.

[0088] The present invention also provides the application of the above photocurable ceramic precursor composition, which is used for preparing resin films / coatings, organic-inorganic hybrid material films / coatings, ceramic films / coatings, ceramic articles, ceramic fibers, ceramic matrix composites, 3D printed ceramic products or ceramic microelectromechanical systems, etc., and is preferably used for preparing 3D printed ceramic products.

[0089] The present invention also provides a method for preparing the above ceramic article, and the method includes:

[0090] Heating and pyrolyzing the above photocurable ceramic precursor composition to prepare a ceramic article.

[0091] According to an embodiment of the present invention, the pyrolysis temperature is 800-1600 °C; the heating time is 0.5-10 h.

[0092] According to an embodiment of the present invention, the pyrolysis is carried out in air or an inert atmosphere, for example, in an argon or nitrogen atmosphere.

[0093] According to an embodiment of the present invention, before pyrolyzing the photocurable ceramic precursor composition, the photocured ceramic precursor composition can also be heat-treated at 100-300 °C to increase its curing degree or mechanical strength.

[0094] According to an embodiment of the present invention, before pyrolyzing the photocurable ceramic precursor composition, the photocurable ceramic precursor composition can also be coated and then photocured to prepare a resin film or coating. The resin film or coating can be further pyrolyzed to prepare an organic-inorganic hybrid material or a ceramic material, wherein the pyrolysis temperature of 500-700 °C is for the organic-inorganic hybrid material, and the pyrolysis temperature of 800-1600 °C is for the ceramic material.

[0095] The present invention also provides a method for preparing the above 3D printed ceramic product, and the method includes:

[0096] K1: Creating a three-dimensional model of a ceramic part;

[0097] K2: Placing the above photocurable ceramic precursor composition in a 3D printer, setting the parameters of the laser, starting the 3D printer, and starting 3D printing to prepare a 3D printed ceramic primary product;

[0098] K3: Pyrolyzing the 3D printed ceramic primary product to prepare a 3D printed ceramic product.

[0099] In step K1, the method of creating a three-dimensional model of a ceramic part is a common method in the prior art, such as computer-aided design (CAD).

[0100] In step K2, it also includes post-treating the 3D printed ceramic primary product. For example, the surface of the 3D printed ceramic product is cleaned with a solvent to remove the unreacted photocurable ceramic precursor. Among them, the solvent is one of isopropyl alcohol, ethanol, n-hexane, acetone, etc.

[0101] In step K3, it may also include post-curing treatment of the 3D printed ceramic product. The specific steps of the post-curing treatment are as follows: After curing the 3D printed ceramic product in an ultraviolet light curing box for 0.5 - 3 h, it is further pyrolyzed at 800 - 1300 °C to prepare the 3D printed ceramic product.

[0102] In step K3, pyrolysis is carried out in an inert atmosphere, and the pyrolysis time is 1 - 5 h.

[0103] Preferably, during pyrolysis, the heating or cooling rate is 0.5 - 2 °C / min, preferably 1 °C / min.

[0104] In step K2, the wavelength of the laser is 254 - 405 nm, for example, 405 nm; the laser power is 100 - 400 mW, for example, 250 mW.

[0105] In step K3, the wavelength of the ultraviolet light curing box is 254 - 405 nm, for example, 405 nm.

[0106] Beneficial effects

[0107] First, the preparation method of the photocurable silicon-based ceramic precursor provided by the present invention has the advantages of easily available raw materials, mild reaction conditions, and high yield;

[0108] Second, the preparation method of the photocurable silicon-based ceramic precursor provided by the present invention has the advantages of rich product types, strong structural designability, controllable reaction and product viscosity, and can achieve low viscosity and good fluidity;

[0109] Third, the photocurable silicon-based ceramic precursor provided by the present invention can be used as a silicon-based ceramic precursor resin, and the ceramicization yield of the cured product is high.

[0110] Fourth, the photocurable silicon-based ceramic precursor and its composition provided by the present invention show great application prospects in the fields of preparing resin films / coatings, organic-inorganic hybrid material films / coatings, ceramic films / coatings, ceramic fibers, ceramic matrix composites, and 3D printing to prepare ceramic parts, etc.

[0111] Terms and definitions

[0112] For the numerical ranges recited in the description and claims of the present application, when the numerical range is defined as "integer", it should be understood that the two endpoints of the range and each integer within the range are recited. For example, "integers from 1 to 5" should be understood to recite each of the integers 1, 2, 3, 4, and 5.

[0113] The term "C 1-20 alkyl" should be understood to denote a straight-chain or branched-chain saturated monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably C 1-10 alkyl. "C 1-10 alkyl" should be understood to preferably denote a straight-chain or branched-chain saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. The alkyl groups are, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, etc. or their isomers. In particular, the group has 1, 2, 3, 4, 5, 6 carbon atoms ("C 1-6 alkyl"), such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, and more particularly, the group has 1, 2, or 3 carbon atoms ("C 1-3 alkyl"), such as methyl, ethyl, n-propyl, or isopropyl.

[0114] The term "C 1-20 alkoxy" denotes -O-C 1-20 alkyl, where C 1-20 alkyl has the above definition.

[0115] The term "C 2-10 alkenyl" should be understood to denote a straight-chain or branched-chain monovalent hydrocarbon group that contains one or more double bonds and has 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms, particularly 2 or 3 carbon atoms ("C 2-3"Alkenyl"), it should be understood that in the case where the alkenyl contains more than one double bond, the double bonds may be separated or conjugated with each other. The alkenyl is, for example, vinyl, allyl, (E)-2-methylvinyl, (Z)-2-methylvinyl, (E)-but-2-enyl, (Z)-but-2-enyl, (E)-but-1-enyl, (Z)-but-1-enyl, pent-4-enyl, (E)-pent-3-enyl, (Z)-pent-3-enyl, (E)-pent-2-enyl, (Z)-pent-2-enyl, (E)-pent-1-enyl, (Z)-pent-1-enyl, hex-5-enyl, (E)-hex-4-enyl, (Z)-hex-4-enyl, (E)-hex-3-enyl, (Z)-hex-3-enyl, (E)-hex-2-enyl, (Z)-hex-2-enyl, (E)-hex-1-enyl, (Z)-hex-1-enyl, isopropenyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl, 2-methylprop-1-enyl, (E)-1-methylprop-1-enyl, (Z)-1-methylprop-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E)-2-methylbut-2-enyl, (Z)-2-methylbut-2-enyl, (E)-1-methylbut-2-enyl, (Z)-1-methylbut-2-enyl, (E)-3-methylbut-1-enyl, (Z)-3-methylbut-1-enyl, (E)-2-methylbut-1-enyl, (Z)-2-methylbut-1-enyl, (E)-1-methylbut-1-enyl, (Z)-1-methylbut-1-enyl, 1,1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, 1-propylvinyl, 1-isopropylvinyl.

[0116] The term "C 2-10"Alkynyl" shall be understood to mean a straight-chain or branched monovalent hydrocarbon group that contains one or more triple bonds and has 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, particularly 2 or 3 carbon atoms ("C2-C3-alkynyl"). The alkynyl group is, for example, ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 1-methylprop-2-ynyl, 2-methylbut-3-ynyl, 1-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, 3-methylpent-4-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, 2-methylpent-3-ynyl, 1-methylpent-3-ynyl, 4-methylpent-2-ynyl, 1-methylpent-2-ynyl, 4-methylpent-1-ynyl, 3-methylpent-1-ynyl, 2-ethylbut-3-ynyl, 1-ethylbut-3-ynyl, 1-ethylbut-2-ynyl, 1-propylprop-2-ynyl, 1-isopropylprop-2-ynyl, 2,2-dimethylbut-3-ynyl, 1,1-dimethylbut-3-ynyl, 1,1-dimethylbut-2-ynyl or 3,3-dimethylbut-1-ynyl. In particular, the alkynyl group is ethynyl, prop-1-ynyl or prop-2-ynyl.

[0117] The term "C 2-12 "Epoxyalkyl" shall be understood to mean a cycloalkane that contains 1 O atom and has 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms, particularly 2-4 carbon atoms, and the cycloalkane shall be saturated. The "C 2-12 "Epoxyalkyl" is, for example, ethylene oxide, propylene oxide, butylene oxide, pentylene oxide.

[0118] The term "epoxy C 3-12 "Cycloalkyl" shall be understood to mean a fused ring formed by ethylene oxide and a cyclic alkane having 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms, and the 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms are not shared carbon atoms. Further, the cyclic alkane shall be saturated. The "epoxy C 3-12 "Cycloalkyl" is, for example,

[0119] BRIEF DESCRIPTION OF THE DRAWINGS

[0120] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention.

[0121] Figure 11H-NMR spectra of the photocurable polysiloxane ceramic precursor obtained in Example 1 1 (The deuterated reagent is deuterated chloroform).

[0122] Figure 2 1H-NMR spectra of the photocurable polysiloxane ceramic precursor obtained in Example 2 1 (The deuterated reagent is deuterated chloroform).

[0123] Figure 3 Photocuring rheological characterization diagram of the photocurable polysiloxane ceramic precursor obtained in Example 2

[0124] Figure 4 Infrared spectra of the photocurable polysiloxane ceramic precursor obtained in Example 2 before and after photocuring

[0125] Figure 5 Thermogravimetric diagrams of the photocured ceramic precursor of the photocurable polysiloxane ceramic precursor obtained in Example 2 and the raw material KH-PSO-1 (the line represented by PSO)

[0126] Figure 6 Schematic diagrams of the 3D printed ceramic parts obtained in Example 2 before and after pyrolysis

[0127] Figure 7 1H-NMR spectra of the photocurable polysiloxane ceramic precursor obtained in Example 3 1 (The deuterated reagent is deuterated chloroform).

[0128] Figure 8 1H-NMR spectra of the photocurable polycarbosilane ceramic precursor obtained in Example 6 1 (The deuterated reagent is deuterated chloroform).

[0129] Figure 9 1H-NMR spectra of the photocurable polycarbosilane ceramic precursor obtained in Example 7 1 (The deuterated reagent is deuterated chloroform).

[0130] Figure 10 1H-NMR spectra of the photocurable polycarbosilane ceramic precursor obtained in Example 8 1 (The deuterated reagent is deuterated chloroform). Detailed implementation manners

[0131] The technical solutions 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 only illustrative of and explanatory of the present invention, and should not be construed as limiting the protection scope 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.

[0132] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0133] Example 1

[0134] A method for synthesizing and preparing a photocurable silicon-based ceramic precursor:

[0135] A 150 mL three-necked round-bottom flask was dried, and a spherical condenser, thermometer, constant-pressure dropping funnel and gas guiding device were connected. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH-PSO-1 containing silicon-hydrogen bonds (3.56 g) were added. Under magnetic stirring, the system was evacuated for 30 min, and then evacuated and filled with nitrogen three times. Under a nitrogen atmosphere, 80 mL of dry toluene solvent, hydroxyethyl acrylate (0.464 g), a hydroxy-containing photosensitive monomer, were successively added to the reaction flask, and then a mixed solution of catalyst N,N-diethylhydroxylamine (0.036 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60-65 °C for 18 h, and the heating was stopped.

[0136] Under stirring, an absorbent acidic ion exchange resin (10 g) of catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain a photocurable polysiloxane ceramic precursor final product, which was a colorless transparent liquid with a yield of 95%. This product corresponds to the structure in formula M, where R is -CH3, R' is -CH3, x = 0.1, y = 0.5, z = 0 (confirmed by NMR spectrum), X is -O(CH2)2OOC-CH=CH2, Y is -CH=CH2, and the specific structure is shown in formula M1. It can be known from GPC test that its molecular weight Mw = 22953 and Mn = 3022.

[0137]

[0138] This product was sealed and stored at room temperature for 3 months. The viscosity was measured by a viscometer and hardly changed, about 178 cP. Using 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone, it was cured under ultraviolet light at a wavelength of 365 nm (room temperature), and the irradiation time was 5 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of this cured product at 1000 °C was 78%.

[0139] Figure 1 For the reaction product M1 of Example 1 1 1H-NMR spectrum. Figure 1Among them, the peak at a chemical shift of 0 - 0.25 ppm can be attributed to the Si-CH3 structure in the product, and the peaks at chemical shifts of 3.92, 4.22, 6.14, 6.16, 6.39, and 6.43 ppm can be attributed to the photosensitive group -O(CH2)2OOC-CH=CH2. The resonance peak at a chemical shift of 4.71 ppm can be attributed to the Si-H group in the KH-PSO-1 structure, and the resonance peak at a chemical shift of 5.7 - 6.1 ppm can be attributed to the Si-CH=CH2 group in the KH-PSO-1 structure. Compared with the raw material KH-PSO-1, the Si-H peak decreases, and the peak of the newly formed photosensitive group -O(CH2)2OOC-CH=CH2 appears, indicating that the photosensitive group has been successfully introduced and a photocurable polysiloxane ceramic precursor has been obtained.

[0140] Example 2

[0141] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel, and a gas guiding device. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH-PSO-1 containing silicon-hydrogen bond (3.56 g) were added. Under magnetic stirring and nitrogen atmosphere, 80 mL of dry toluene solvent and hydroxyethyl acrylate (0.928 g), a hydroxy-containing photosensitive monomer, were successively added to the reaction flask. Then, a mixed solution of the catalyst N,N-diethylhydroxylamine (0.036 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 24 h, and then the heating was stopped.

[0142] Under stirring, an absorbent acidic ion exchange resin (10 g) of the catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain a photocurable polysiloxane ceramic precursor final product, which was a colorless transparent liquid with a yield of 93%. This product corresponds to the structure in formula M, where R is -CH3, R’ is -CH3, x = 0.2, y = 0.5, z = 0 (confirmed by NMR spectrum), X is -O(CH2)2OOC-CH=CH2, and Y is -CH=CH2. The specific structure is shown in formula M2. It can be known from GPC test that its molecular weight Mw = 26539 and Mn = 3478.

[0143]

[0144] This product was sealed and stored at room temperature for 3 months. The viscosity was measured by a viscometer and hardly changed, about 306 cP. Using 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone, it was cured under ultraviolet light with a wavelength of 365 nm (room temperature), and the irradiation time was 5 min, and the curing was complete. Under nitrogen atmosphere, the ceramic yield of this cured product was 73% at 1000 °C in TGA.

[0145] Figure 2 1H-NMR spectrum of the reaction product M2 in Example 2. The peaks at chemical shifts of 0 - 0.25 ppm can be attributed to the Si-CH3 structure, the peaks at chemical shifts of 3.92, 4.22, 6.14, 6.16, 6.39 and 6.43 ppm can be attributed to the photosensitive group -O(CH2)2OOC-CH=CH2, the resonance peak at chemical shift of 4.71 ppm can be attributed to the Si-H group in the KH-PSO-1 structure, and the resonance peaks at chemical shifts of 5.7 - 6.1 ppm can be attributed to the Si-CH=CH2 group in the PSO structure. Compared with the raw material KH-PSO-1, the Si-H peak decreases, and new peaks of the photosensitive group -O(CH2)2OOC-CH=CH2 appear, indicating that the photosensitive group has been successfully introduced and a photocurable polysiloxane ceramic precursor has been obtained. 1 1H-NMR spectrum of the reaction product M2 in Example 2. The peaks at chemical shifts of 0 - 0.25 ppm can be attributed to the Si-CH3 structure, the peaks at chemical shifts of 3.92, 4.22, 6.14, 6.16, 6.39 and 6.43 ppm can be attributed to the photosensitive group -O(CH2)2OOC-CH=CH2, the resonance peak at chemical shift of 4.71 ppm can be attributed to the Si-H group in the KH-PSO-1 structure, and the resonance peaks at chemical shifts of 5.7 - 6.1 ppm can be attributed to the Si-CH=CH2 group in the PSO structure. Compared with the raw material KH-PSO-1, the Si-H peak decreases, and new peaks of the photosensitive group -O(CH2)2OOC-CH=CH2 appear, indicating that the photosensitive group has been successfully introduced and a photocurable polysiloxane ceramic precursor has been obtained.

[0146] Figure 3 Photocuring rheological curve of the reaction product M2 in Example 2. It can be seen from it that the storage modulus and the loss modulus intersect at 6 s of light irradiation, indicating that the photocuring material changes from liquid to solid and gels at this time. After 20 s of light irradiation, the storage modulus and the loss modulus tend to balance, indicating that the photocuring material has been completely cured.

[0147] Figure 4 Infrared spectra of the reaction product M2 in Example 2 before and after photocuring (the solid line is the characterization result before curing, and the dashed line is the characterization result after curing). The vinyl peak (1635 cm -1 ) in the photosensitive group -O(CH2)2OOC-CH=CH2 decreases significantly after photocuring, indicating that the photosensitive group participates in the photocuring reaction.

[0148] Figure 5 Thermogravimetric curves (TG) of the reaction product M2 in Example 2 after photocuring and the raw material KH-PSO-1. It can be seen from the TG curves that the ceramic yield of the product after photocuring is 73% in a nitrogen atmosphere at 1000 °C, while the ceramic yield of the product after thermal curing of the raw material KH-PSO-1 is 83% in a nitrogen atmosphere at 1000 °C.

[0149] Figure 6 Structural images of the ceramic precursor parts prepared from the reaction product M2 in Example 2 by 3D printing before and after pyrolysis (1000 °C). It can be seen from the figure that the shape of the pyrolysis product remains intact, there are no obvious cracks, and the shrinkage is uniform in all directions.

[0150] Example 3

[0151] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH-PSO-1 (3.56 g) containing silicon-hydrogen bonds were added. Under magnetic stirring and nitrogen protection atmosphere, dry toluene solvent (80 mL), hydroxy-containing photosensitive monomer 2-hydroxyethyl acrylate (1.856 g) were successively added to the reaction flask. Then, a mixed solution of catalyst N,N-diethylhydroxylamine (0.072 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 24 h, and then the heating was stopped.

[0152] Under stirring, an absorbent acidic ion exchange resin (20 g) of catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain a photocurable polysiloxane ceramic precursor final product, which was a colorless transparent liquid with a yield of 90%. This product corresponded to the structure in formula M, where R was -CH3, R’ was -CH3, x = 0.4, y = 0.5, z = 0 (confirmed by NMR spectrum), X was -O(CH2)2OOC-CH=CH2, Y was -CH=CH2, and the specific structure was shown in formula M3. It was known from GPC test that its molecular weight Mw = 31256 and Mn = 4127.

[0153]

[0154] This product was sealed and stored at room temperature for 3 months. The viscosity was found to have almost no change by GPC test, about 465 cP. Using 1 wt% photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, it was cured under ultraviolet light with a wavelength of 405 nm at room temperature for 5 min, and the curing was complete. Under nitrogen atmosphere, the ceramic yield of this cured product was 57% at 1000 °C by TGA.

[0155] Figure 7 For the 1 1H-NMR spectrum of the reaction product M3 in Example 3, it was found that compared with the raw material KH-PSO-1, the Si-H peak decreased, and a new peak of the photosensitive group -O(CH2)2OOC-CH=CH2 appeared, indicating that the photosensitive group was successfully introduced and a photocurable polysiloxane ceramic precursor was obtained.

[0156] Example 4

[0157] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH-PSO-1 containing silicon-hydrogen bonds (3.56 g) were added. Under magnetic stirring and nitrogen atmosphere, dry toluene solvent (80 mL), a hydroxyl-containing photosensitive monomer 4-hydroxybutyl vinyl ether (1.392 g) were successively added to the reaction flask. Then, a mixed solution of catalyst N,N-diethylhydroxylamine (0.054 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60-65 °C for 24 h, and the heating was stopped.

[0158] Under stirring, an absorbent acidic ion exchange resin (15 g) of catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain a photocurable polysiloxane ceramic precursor final product, which was a colorless transparent liquid with a yield of 92%. This product corresponded to the structure in formula M, where R was -CH3, R' was -CH3, x = 0.2, y = 0.5, z = 0 (confirmed by NMR spectrum), X was -O(CH2)4-O-CH=CH2, Y was -CH=CH2, and the specific structure was as shown in formula M4. It was known from GPC test that its molecular weight Mw = 27317 and Mn = 3615.

[0159]

[0160] This product was stored sealed at room temperature for 3 months. The viscosity was almost unchanged by viscometer test, about 366 cP. 5 wt% photoinitiator triarylsulfonium hexafluorantimonate was added and cured under ultraviolet light at a wavelength of 365 nm (room temperature) for 10 min, and the curing was complete. Under nitrogen atmosphere, the ceramic yield of this cured product was 65% at 1000 °C by TGA.

[0161] Example 5

[0162] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH-PSO-1 containing silicon-hydrogen bonds (3.56 g) were added. Under magnetic stirring and nitrogen atmosphere, toluene solvent (80 mL), a hydroxyl-containing photosensitive monomer 1-hydroxymethyl-3-cyclohexene oxide (1.026 g) were successively added to the reaction flask. Then, a mixed solution of catalyst N,N-diethylhydroxylamine (0.072 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60-65 °C for 24 h, and the heating was stopped.

[0163] Under stirring, an absorbent acidic ion exchange resin (20 g) of catalyst N,N - diethylhydroxylamine was added to the above - mentioned system, and stirring was continued for more than 6 h at room temperature to remove the catalyst N,N - diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polysiloxane ceramic precursor, which was a colorless transparent liquid with a yield of 80%. This product corresponded to the structure in formula M, where R was - CH3, R’ was - CH3, x = 0.2, y = 0.5, z = 0 (confirmed by NMR spectrum), and X was Y was - CH=CH2, and the specific structure was as shown in formula M5. As determined by GPC, its molecular weight Mw = 27673 and Mn = 3748.

[0164]

[0165] This product was sealed and stored at room temperature for 3 months. The viscosity was measured by a viscometer and hardly changed, about 178 cP. 5 wt% photoinitiator triarylsulfonium hexafluoroantimonate was added, and it was cured under ultraviolet light at a wavelength of 365 nm for 15 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of this cured product was 57% at 1000℃ by TGA.

[0166] Example 6

[0167] A 150 mL three - necked round - bottom flask was dried and connected with a spherical condenser, a thermometer, a constant - pressure dropping funnel and a gas - guiding device. A magnetic stirrer and a liquid polycarbosilane ceramic precursor resin KH - AHPCS - 1 (1.10 g) containing silicon - hydrogen bonds were added. Under magnetic stirring and a nitrogen - protecting atmosphere, dry toluene solvent (80 mL), hydroxy - containing photosensitive monomer 2 - hydroxyethyl acrylate (0.46 g) were successively added to the reaction flask, and then a mixed solution of catalyst N,N - diethylhydroxylamine (0.045 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65℃ for 18 h, and then the heating was stopped.

[0168] Under stirring, an absorbent acidic ion exchange resin (10 g) of catalyst N,N - diethylhydroxylamine was added to the above - mentioned system, and stirring was continued for more than 6 h at room temperature to remove the catalyst N,N - diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polysiloxane ceramic precursor. It was a colorless transparent liquid with a yield of 95%. This product corresponded to the structure in formula N, where R was - H, R’ was - H, x = 0.2, y = 0.1, z = 0 (confirmed by NMR spectrum), X was - O(CH2)2OOC - CH=CH2, Y was - CH2 - CH=CH2, and the specific structure was as shown in formula N1. As determined by GPC, its molecular weight Mw = 6845 and Mn = 966.

[0169]

[0170] The viscosity of the product at room temperature is 236 cP. 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone is added, and it is cured under ultraviolet light with a wavelength of 365 nm at room temperature for 5 minutes, and the curing is complete. Under a nitrogen atmosphere, the TGA ceramic yield of the cured product at 1000 °C is 74%.

[0171] Figure 8 For the reaction product N1 of Example 6 1 1H-NMR spectrum. As can be seen from the figure, the intensity of the Si-H3 peak of the product is significantly reduced compared to the raw material KH-AHPCS-1, and a new resonance absorption peak of the photosensitive group -O(CH2)2OOC-CH=CH2 is generated, indicating that the photosensitive group has been successfully introduced and a photocurable polycarbosilane ceramic precursor has been obtained.

[0172] Example 7

[0173] A 150 mL three-necked round-bottom flask was dried, connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device, a magnetic stirrer was added, and the liquid polycarbosilane ceramic precursor resin KH-VHPCS-1 (2.05 g) containing silicon-hydrogen bonds was added. Under magnetic stirring, it was evacuated for 30 minutes, and then evacuated and replaced with nitrogen three times. Under a nitrogen atmosphere, dry toluene solvent (80 mL), hydroxy-containing photosensitive monomer 2-hydroxyethyl acrylate (0.92 g) were successively added to the reaction flask, and then a mixed solution of catalyst N,N-diethylhydroxylamine (0.045 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 18 h, and the heating was stopped.

[0174] Under stirring, the absorbent acidic ion exchange resin (10 g) of catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polycarbosilane ceramic precursor. It is a colorless transparent liquid with a yield of 95%. The product corresponds to the structure in formula N, where R is -H, R' is H, x = 0.2, y = 0.1, z = 0 (confirmed by NMR spectrum), X is -O(CH2)2OOC-CH=CH2, Y is -CH=CH2, and the specific structure is shown in formula N2. It can be known from GPC test that its molecular weight Mw = 6445 and Mn = 783.

[0175]

[0176] The product was stored sealed at room temperature for 1 month. After testing with a viscometer, its viscosity hardly changed and was approximately 459 cP. 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone was added, and it was cured under ultraviolet light at a wavelength of 365 nm (room temperature) for 5 min, and the curing was complete. Under a nitrogen atmosphere, the TGA ceramic yield of the cured product at 1000 °C was 78%.

[0177] Figure 9 For the reaction product N2 of Example 7 1 1H-NMR spectrum. From Figure 9 It can be found that the absorption peak intensity attributed to Si-H3 of the product relative to the raw material KH-VHPCS-1 decreased significantly, and a new absorption peak attributed to the photosensitive group -O(CH2)2OOC-CH=CH2 appeared, indicating that the photosensitive group was successfully introduced and a photocurable polycarbosilane ceramic precursor was obtained.

[0178] Example 8

[0179] A 150 mL three-necked round-bottom flask was dried, connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stirrer and sodium hydroxide (0.16 g) were added, and it was heated under vacuum at 50 °C for 30 min for drying, and then nitrogen was replaced. Under magnetic stirring, anhydrous tetrahydrofuran solvent (80 mL) was successively added to the reaction flask, and then a mixed solution of the liquid polycarbosilane ceramic precursor resin KH-AHPCS-2 (2.05 g) containing silicon-hydrogen bond and anhydrous tetrahydrofuran (20 mL) was added to the reaction flask. After stirring evenly, at 60 - 65 °C, hydroxyethyl acrylate (1.38 g), a hydroxy-containing photosensitive monomer, was added dropwise, and the reaction was carried out for 18 h, and then the heating was stopped.

[0180] Under stirring, 50 mL of n-hexane was added to the reaction flask. The above system was added to an aqueous hydrochloric acid solution (100 ml, 0.03 g / ml), and was thoroughly mixed in a separatory funnel, allowed to stand for liquid separation, and the upper organic phase was subjected to the above acid washing operation twice. After drying over anhydrous magnesium sulfate, filtering and rotary evaporation to remove the solvent and other steps, the final product of the photocurable polycarbosilane ceramic precursor was obtained as a colorless transparent liquid with a yield of 95%. This product corresponds to the structure in formula N, where R is -H, R' is -H, x = 0.3, y = 0.1, z = 0 (confirmed by NMR spectrum), X is -O(CH2)2OOC-CH=CH2, Y is -CH=CH2, and the specific structure is shown in formula N3. It can be known from GPC test that its molecular weight Mw = 6727 and Mn = 754.

[0181]

[0182] The product was stored sealed at room temperature for 1 month. After testing with a viscometer, its viscosity hardly changed, being approximately 270 cP. 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone was added and it was cured under ultraviolet light at a wavelength of 365 nm for 5 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of the cured product at 1000 °C by TGA was 78%.

[0183] Figure 10 For the reaction product N3 of Example 8 1 The 1H-NMR spectrum shows that, compared with the raw material KH-AHPCS-2, the Si-H3 group significantly decreases, and a new photosensitive group -O(CH2)2OOC-CH=CH2 is newly formed, indicating that the photosensitive group has been successfully introduced and a photocurable polycarbosilane ceramic precursor has been obtained.

[0184] Example 9

[0185] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stirrer and a liquid polycarbosilane ceramic precursor resin KH-HPCS-1 (1.76 g) containing silicon-hydrogen bonds were added. Under magnetic stirring, it was evacuated for 30 min, and then evacuated and replaced with nitrogen three times. Under a nitrogen atmosphere, dry toluene solvent (80 mL) and hydroxy-containing photosensitive monomer 2-hydroxyethyl acrylate (0.92 g) were successively added to the reaction flask. Then, a mixed solution of catalyst N,N-diethylhydroxylamine (0.045 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 18 h, and the heating was stopped.

[0186] Under stirring, an absorbent acidic ion exchange resin (10 g) of catalyst N,N-diethylhydroxylamine was added to the above system, and stirring was continued at room temperature for more than 6 h to remove the catalyst N,N-diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polycarbosilane ceramic precursor. It was a colorless transparent liquid with a yield of 95%. This product corresponded to the structure in Formula N, where R was -H, x = 0.2, y = 0, z = 0 (confirmed by NMR spectrum), and X was -O(CH2)2OOC-CH=CH. The specific structure was as shown in Formula N4. It was known from GPC testing that its molecular weight Mw = 5456 and Mn = 856.

[0187]

[0188] The viscosity of this product at room temperature was 223 cP. 1 wt% photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone was added and it was cured under ultraviolet light at a wavelength of 365 nm (room temperature) for 5 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of the cured product at 1000 °C by TGA was 79%.

[0189] Example 10

[0190] A 150 mL three-necked round-bottom flask was dried and connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stir bar and sodium hydroxide (0.16 g) were added. Under the heating condition of 50 °C, the vacuum was pumped for 30 min, and then the vacuum was pumped and nitrogen was replaced three times. Under magnetic stirring and nitrogen atmosphere, the reaction flask was successively added with ultra-dry tetrahydrofuran solvent (80 mL), and then a mixed solution of a silicon-hydrogen bond-containing liquid polycarbosilane ceramic precursor resin KH-VHPCS-1 (2.05 g) and ultra-dry tetrahydrofuran (20 mL) was added to the reaction flask. After stirring evenly, at 60-65 °C, 4-hydroxybutyl vinyl ether (0.92 g), a hydroxyl-containing photosensitive monomer, was added dropwise, and the reaction was carried out for 18 h, and then the heating was stopped.

[0191] Under stirring, 50 mL of n-hexane was added to the reaction flask. The above system was added to an aqueous hydrochloric acid solution (100 mL, 0.03 g / mL), and was thoroughly mixed in a separatory funnel, allowed to stand for layer separation, and the upper organic phase was subjected to the above pickling operation twice. After drying over anhydrous magnesium sulfate, filtering and rotary evaporation to remove the solvent and other steps, a photocurable polycarbosilane ceramic precursor final product was obtained, which was a colorless transparent liquid with a yield of 95%. This product corresponded to the structure in formula N, where R was -H, R' was -H, x = 0.2, y = 0.1, z = 0 (confirmed by NMR spectrum), X was -O(CH2)4-O-CH=CH2, Y was -CH=CH2, and the specific structure was as shown in formula N5. It was known from GPC test that its molecular weight Mw = 6872 and Mn = 869.

[0192]

[0193] The viscosity of this product at room temperature was 340 cP. 5 wt% photoinitiator triarylsulfonium hexafluoroantimonate was added, and it was cured under ultraviolet light with a wavelength of 365 nm (room temperature), and the irradiation time was 5 min, and the curing was complete. Under nitrogen atmosphere, the ceramic yield of this cured product at 1000 °C was 78%.

[0194] Example 11

[0195] A 150 mL three-necked round-bottom flask was dried, connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stir bar and sodium hydroxide (0.16 g) were added. It was heated under vacuum at 50 °C for 30 min, and then evacuated and replaced with nitrogen three times. Under magnetic stirring and nitrogen atmosphere, dry tetrahydrofuran solvent (80 mL) was successively added to the reaction flask, and then a mixed solution of the silicon-hydrogen bond-containing liquid polycarbosilane ceramic precursor resin KH-VHPCS-1 (2.05 g) and dry tetrahydrofuran (20 mL) was added to the reaction flask. After stirring evenly, at 60 - 65 °C, the hydroxy group-containing photosensitive monomer 1-hydroxymethyl-3-cyclohexene oxide (1.02 g) was added dropwise, and the reaction was carried out for 18 h, then the heating was stopped.

[0196] Under stirring, 50 mL of n-hexane was added to the reaction flask. The above system was added to an aqueous hydrochloric acid solution (100 mL, 0.03 g / mL), and was thoroughly mixed in a separatory funnel, allowed to stand for layer separation. The upper organic phase was subjected to the above acid washing operation twice. After drying over anhydrous magnesium sulfate, filtering, and rotary evaporation to remove the solvent and other steps, the finally obtained photocurable polycarbosilane ceramic precursor product was a colorless transparent liquid with a yield of 95%. This product corresponded to the structure in Formula N, where R was -H, R’ was -H, x = 0.2, y = 0.1, z = 0 (confirmed by NMR spectrum), and X was Y was -CH=CH2, and the specific structure was as shown in Formula N6. It was known from GPC test that its molecular weight Mw = 6851 and Mn = 827.

[0197]

[0198] The viscosity of this product at room temperature was 628 cP. 5 wt% photoinitiator triarylsulfonium hexafluoroantimonate was added, and it was cured under ultraviolet light at a wavelength of 365 nm (room temperature), with a light irradiation time of 5 min, and the curing was complete. Under nitrogen atmosphere, the ceramic yield of this cured product was 78% at 1000 °C by TGA.

[0199] Example 12

[0200] A 150 mL three-necked round-bottom flask was dried, connected with a spherical condenser, a thermometer, a constant-pressure dropping funnel and a gas guiding device. A magnetic stir bar and the silicon-hydrogen bond-containing liquid polysiloxane ceramic precursor resin KH-PSO-4 (3.56 g) were added. Under magnetic stirring, it was evacuated for 30 min, and then evacuated and filled with nitrogen three times. Under nitrogen atmosphere, dry toluene solvent (80 mL), the hydroxy group-containing photosensitive monomer 2-hydroxyethyl acrylate (0.464 g) were successively added to the reaction flask, and then a mixed solution of the catalyst N,N-diethylhydroxylamine (0.036 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 18 h, then the heating was stopped.

[0201] Under stirring, an absorbent acidic ion exchange resin (10 g) of catalyst N,N - diethylhydroxylamine was added to the above - mentioned system, and stirring was continued for more than 6 h at room temperature to remove the catalyst N,N - diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polysiloxane ceramic precursor, which was a colorless transparent liquid with a yield of 95%. This product corresponded to the structure in formula M, where R was -CH3, R’ was -CH3, x = 0.1, y = 0.45, z = 0.1 (confirmed by NMR spectrum), X was -O(CH2)2OOC-CH=CH2, Y was -CH=CH2, and the specific structure was as shown in formula M6. As determined by GPC, its molecular weight Mw = 21673 and Mn = 2988.

[0202]

[0203] This product was sealed and stored at room temperature for 3 months. After testing with a viscometer, the viscosity hardly changed, being approximately 345 cP. Using 1 wt% photoinitiator 2,4,6 - trimethylbenzoyl - ethoxy - phenylphosphine oxide, it was cured under ultraviolet light with a wavelength of 405 nm at room temperature for 5 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of this cured product was 73% at 1000 °C by TGA.

[0204] Example 13

[0205] A 150 mL three - necked round - bottom flask was dried and connected with a spherical condenser, a thermometer, a constant - pressure dropping funnel and a gas - guiding device. A magnetic stirrer and a liquid polysiloxane ceramic precursor resin KH - PSO - 3 (3.56 g) containing silicon - hydrogen bonds were added. Under magnetic stirring, it was evacuated for 30 min, and then evacuated and filled with nitrogen three times. Under a nitrogen atmosphere, 80 mL of dry toluene solvent, hydroxy - containing photosensitive monomer 2 - hydroxyethyl acrylate (0.464 g) were successively added to the reaction flask, and then a mixed solution of catalyst N,N - diethylhydroxylamine (0.036 g) and toluene (20 mL) was added to the reaction flask. After stirring evenly, the reaction was carried out at 60 - 65 °C for 18 h, and then the heating was stopped.

[0206] Under stirring, an absorbent acidic ion exchange resin (10 g) of catalyst N,N - diethylhydroxylamine was added to the above - mentioned system, and stirring was continued for more than 6 h at room temperature to remove the catalyst N,N - diethylhydroxylamine. After filtration, the solvent was removed by rotary evaporation to obtain the final product of the photocurable polysiloxane ceramic precursor, which was a colorless transparent liquid with a yield of 94%. This product corresponded to the structure in formula M, where R was - CH3, R’ was - CH3, x = 0.1, y = 0.35, z = 0.3 (confirmed by NMR spectrum), X was - O(CH2)2OOC - CH = CH2, Y was - CH = CH2, and the specific structure was as shown in formula M7. As determined by GPC, its molecular weight Mw = 22491 and Mn = 3519.

[0207]

[0208] This product was sealed and stored at room temperature for 3 months. After testing with a viscometer, the viscosity hardly changed, approximately 399 cP. Using 1 wt% photoinitiator 2,4,6 - trimethylbenzoyl - ethoxy - phenylphosphine oxide, it was cured under ultraviolet light irradiation at a wavelength of 405 nm (room temperature) for 5 min, and the curing was complete. Under a nitrogen atmosphere, the ceramic yield of this cured product was 71% at 1000 °C by TGA.

[0209] Example 14

[0210] A preparation method of a photocurable ceramic precursor system:

[0211] 40 g of the product M2 obtained in Example 2, 0.2 g of photoinitiator 2 - hydroxy - 2 - methyl - 1 - phenylpropanone, 0.2 g of photoinitiator phenylbis(2,4,6 - trimethylbenzoyl)phosphine oxide, and 0.12 g of ultraviolet absorber hexamethylphosphoramide (HMPA) were added to a 150 - mL single - necked flask. After magnetic stirring for 2 h to mix evenly, a photocurable 3D - printable photocurable ceramic precursor system was prepared and poured into a brown reagent bottle for storage in the dark for standby.

[0212] A preparation method of a 3D - printed ceramic part:

[0213] 3D printing was carried out using the research - type ceramic material 3D printing system CeraMatrix (self - developed by the Space Center). The wavelength of the ultraviolet laser was 405 nm, the laser power was 250 mw, the layer thickness was set to 100 microns, a three - dimensional model was created by computer - aided design (CAD) and saved as an STL file; after 3D printing, a preliminary product of the 3D - printed ceramic part was prepared.

[0214] The initial product of the 3D printed ceramic part was cleaned with isopropanol to remove the uncured photosensitive polysiloxane ceramic precursor on the surface. Then, the initial product of the 3D printed ceramic part was post-cured in a UV curing oven (CL-1000L) for 30 minutes and weighed 1.418 g. In order to convert the honeycomb structure part into ceramic, under the protection of flowing argon in a tube furnace (Hefei Kejing, OTF-1200X-S), it was heated to 1000 °C at a rate of 1 °C / min and held for 2 hours to obtain the 3D printed ceramic part product. The weight of the ceramic part after pyrolysis was 1.04 g, and the ceramic yield was 1.04 / 1.418 * 100% = 73%. Schematic diagrams of the honeycomb structure part before and after pyrolysis are as Figure 6 shown, and it can be seen from Figure 6 that the structure of the precursor part after printing is complete and has high resolution. The ceramic part after pyrolysis shrinks uniformly without obvious cracks and defects.

[0215] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a photocurable silicon-based ceramic precursor, the photocurable silicon-based ceramic precursor having a segment structure as shown in formula N, characterized in that, It includes the following steps: Wherein, R and R’ are the same or different and are each independently selected from H, unsubstituted, or the following groups optionally substituted by one, two or more Ra: C 1-6 alkyl or C 1-6 alkoxy; Ra is selected from hydroxy, halogen, amino or C 1-6 alkyl; Y is the same or different and is independently selected from the following groups which are unsubstituted or optionally substituted by one, two or more Rb: C 2-6 alkenyl or C 2-6 alkynyl; Rb is selected from hydroxy, halogen, amino or C 1-6 alkyl; X are the same or different and are independently selected from photosensitive reactive groups Rg, and the photosensitive reactive group Rg is a group that undergoes a polymerization reaction under the conditions of light irradiation and the presence of a photoinitiator; The photosensitive reactive group Rg is an acrylate group, a vinyl ether group or an epoxy group; The acrylate group is selected from -A-OOC-C(R1)=CH2, where A is selected from absent or -O(CH2) a -, when A is absent, the O in -OOC- of -OOC-C(R1)=CH2 is connected to Si, and when present, -O(CH2) a - the O in is connected to Si, a is an integer from 1 to 6, and R1 is selected from H, C 1-6 alkyl; The vinyl ether group is selected from the groups shown in formula (2): -O-(CH2) m1 -O-(CH2) m2 -C(R2)=CH(R3) Formula (2) wherein, m1 is an integer from 1 to 6, m2 is an integer from 0 to 6, R2 is selected from H, methyl or ethyl, and R3 is selected from H or C 1-6 alkyl; The epoxy group is selected from -O(CH2) n1 -R4, where n1 is an integer from 1 to 6, and R4 is selected from substituted or unsubstituted C 2-12 epoxyalkyl group, substituted or unsubstituted epoxy C 3-12 cycloalkyl group, and when substituted, the substituent is C 1-6 alkyl group; x = 0.01 - 0.9, y = 0.1 - 0.9, z = 0.1 - 0.9, x + y + z = 0.01 - 0.9; It includes the following steps: using a silicon-based ceramic precursor resin containing a silicon-hydrogen bond and a photosensitive monomer Rg-H containing a hydroxyl group as raw materials, and carrying out a catalytic reaction in the presence of a dehydrogenative coupling catalyst; Rg in Rg-H has the definition described in claim 1; The silicon-based ceramic precursor resin containing a silicon-hydrogen bond is selected from liquid polycarbosilane; The dehydrogenative coupling catalyst is selected from transition metal catalysts, alkali metal catalysts, and metal-free organic catalysts.

2. The preparation method according to claim 1, characterized in that, The reaction is carried out in a solvent, and the solvent includes benzene-containing solvents, ether solvents, and low-boiling alkane solvents; The low-boiling alkane solvent is one, two or more of pentane, cyclopentane, hexane and petroleum ether.

3. The preparation method according to claim 1 or 2, characterized in that, The transition metal catalyst is selected from Group 4 metallocene complex catalysts, Cp2MR2 (M = Ti, Zr, Hf; R = alkyl, Ph, H; Cp = η 5 -cyclopentadienyl or its alkyl-substituted derivative) or Cp2MX2 / n-BuLi (M = Ti, Zr, Hf; X = Cl, OAr), Ti IV , Mn II , Re IV , Fe II , Ru II , Rh II , Ir II , Ni II , Cu II , Au I , Pt II and Zn II homogeneous metal complexes; lanthanide metallocenes; one, two or more of palladium chloride and nickel chloride; The alkali metal catalyst is one, two or more of fluoride salt KF, strong bases NaOH, KOH, alkali metal salts [MN(SiMe3)2] (M = Li, Na, K), sodium tris(sec-butyl)borohydride, potassium tris(sec-butyl)borohydride, lithium tris(sec-butyl)borohydride; The metal-free organic catalyst is one, two or more of tris(pentafluorophenyl)borane, N-heterocyclic carbenes (NHCs), N,N-diethylhydroxylamine, tetrabutylammonium fluoride; 4. The preparation method according to claim 3, characterized in that, The transition metal catalyst is selected from one, two or three of Cp2Ti(CH3)2, palladium chloride, nickel chloride; The alkali metal catalyst is one, two or more of NaOH, [NaN(SiMe3)2], sodium tris(sec-butyl)borohydride; The metal-free organic catalyst is at least one of N,N-diethylhydroxylamine and tris(pentafluorophenyl)borane.

5. The preparation method according to any one of claims 1-4, characterized in that, The molar ratio of Si-H in the silicon-based ceramic precursor resin containing a silicon-hydrogen bond to -OH in the photosensitive monomer containing -OH is 1:(0.01 - 1).

6. The preparation method according to any one of claims 1-5, characterized in that, The preparation method further includes post-treatment: removing the dehydrogenative coupling catalyst, and distilling the obtained photocurable silicon-based ceramic precursor to obtain the final product.

7. The preparation method according to any one of claims 1-6, characterized in that, The reaction temperature is 35°C - 70°C; the reaction time is 6h - 24h.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The method is: (1) Under stirring, add a dehydrogenative coupling catalyst to the silicon-based ceramic precursor resin containing a silicon-hydrogen bond and the photosensitive monomer containing a hydroxyl group, and carry out the catalytic reaction under suitable solvent and temperature conditions; (2) Add an absorbent for the dehydrogenative coupling catalyst, remove the catalyst, and carry out post-treatment such as filtration, centrifugation or phase separation by adding water and a low-boiling alkane and distillation to obtain a purified final product, the photocurable silicon-based ceramic precursor.

9. The preparation method according to any one of claims 1-8, characterized in that, R is H, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxy-substituted C 1-4 alkyl or halo C 1-4 alkyl; wherein R’ is H, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 hydroxy-substituted C 1-4 alkyl or halogenated C 1-4 alkyl; Y is CH2=CH-, CH2=CHCH2-, CH2=C(CH3)-, CH3CH=CH-, HC≡C-, HC≡C-CH2- or cyclopropyl-(CH2)2CH-. Preferably, x is 0.05 - 0.50, y is 0.1 - 0.5, z is 0.1 - 0.5; x + y + z = 0.1 - 0.

8.

10. The preparation method according to any one of claims 1-9, characterized in that, The acrylate group is selected from -OOC-CH=CH2, -OOC-C(CH3)=CH2, -O(CH2)2OOC-CH=CH2, -O(CH2)3OOC-CH=CH2, -O(CH2)2OOC-C(CH3)=CH2, -O(CH2)3OOC-C(CH3)=CH2; The vinyl ether group is selected from -OCH2-O-CH=CH2, -O(CH2)2-O-CH=CH2, -OCH2-O-CH=CH-CH3, -OCH2-O-CH=CH-C2H5, -OCH2-O-CH=CH-C3H7, -O(CH2)3-O-CH=CH2, -O(CH2)4-O-CH=CH2, -O(CH2)5-O-CH=CH2, -O(CH2)6-O-CH=CH2, -OCH2-O-CH2-CH=CH2, -O(CH2)2-O-CH2-CH=CH2, -O(CH2)3-O-CH2-CH=CH2, -O(CH2)4-O-CH2-CH=CH2, -O(CH2)5-O-CH2-CH=CH2, -O(CH2)6-O-CH2-CH=CH2; R4 is selected from ● indicates the connection site; Preferably, the photocurable silicon-based ceramic precursor has a structure shown by any one of the following formulas N1 to N6:

Images