Dual-curable trapezoidal polysilsesquioxane as well as preparation method and application thereof

Abstract

The invention discloses dual-curing trapezoidal polysilsesquioxane as well as a preparation method and application thereof, and belongs to the technical field of coating materials. The trapezoidal polysilsesquioxane retains an inorganic Si-O-Si rigid main chain, provides excellent mechanical properties for the trapezoidal polysilsesquioxane, enriches the types of organic side group functional groups, and brings good adhesive force for the trapezoidal polysilsesquioxane. More optional curing modes are provided for the UV photocuring trapezoidal polysilsesquioxane coating, and the requirements of different environments and application scenes can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of coating materials, and particularly relates to a doubly curable ladder-type polyhedral oligomeric silsesquioxane and a preparation method and application thereof. Background Art

[0002] Polyhedral oligomeric silsesquioxane (RSiO 1.5 ) n is a kind of special organosilicon compound, including types such as random polyhedral oligomeric silsesquioxane, cage-type polyhedral oligomeric silsesquioxane, and ladder-type polyhedral oligomeric silsesquioxane. Among them, the ladder-type polyhedral oligomeric silsesquioxane is composed of an inorganic and rigid main chain with Si-O-Si and functional groups with special organic photoactivity. It has a double-chain polymer network structure. Compared with other types in the polyhedral oligomeric silsesquioxane family, it has stronger stability and better solubility. In addition, compared with other organic polymers, the ladder-type polyhedral oligomeric silsesquioxane has excellent heat resistance and mechanical properties, which also benefits from its unique structure.

[0003] UV curing is an important way to quickly, greenly and efficiently crosslink the photoactive functional groups inside the coating. Common UV curing methods include free radical photo-curing, cationic photo-curing, cationic-free radical double curing, etc. Generally, the functional groups in organic polymers are complex. During photo-curing, it will cause uneven curing and large shrinkage stress after curing, resulting in limitations in resins and coatings.

[0004] Currently, the research mainly focuses on traditional bifunctional ladder-type polyhedral oligomeric silsesquioxane. So far, there has been no report on a doubly curable ladder-type polyhedral oligomeric silsesquioxane containing two different photoactive functional groups, its preparation method and product application. Summary of the Invention

[0005] The purpose of the present invention is to provide a doubly curable ladder-type polyhedral oligomeric silsesquioxane and a preparation method and application thereof. The preparation process of this method is simple and the conditions are mild.

[0006] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions to achieve it.

[0007] A kind of ladder-type polyhedral oligomeric silsesquioxane, the structural general formula is as follows:

[0008]

[0009] Among them,

[0010] n≥6;

[0011] R 1 -R n are independently selected from alkyl acryloxy groups, epoxy groups or alkyl groups; at the same time, R 1 -R nAt least one of them is methacryloxymethyl 、 Methacryloyloxyethyl 、 Methacryloyloxypropyl 、 Ethacryloxymethyl 、 Ethacryloyloxyethyl 、 Ethacryloyloxypropyl; meanwhile R 1 -R n At least one of them is epoxycyclohexylmethyl, epoxycyclohexylethyl, epoxycyclohexylpropyl, glycidyloxyethyl, glycidyloxypropyl; meanwhile R 1 -R n At least one of them is phenyl, methyl, ethyl, propyl, cyclohexylethyl; T 3 Is trimethyl or triethyl.

[0012] Preferably, R 1 -R n Are independently selected from methacryloxymethyl 、 Methacryloyloxyethyl 、 Methacryloyloxypropyl 、 Ethacryloxymethyl 、 Ethacryloyloxyethyl 、 Ethacryloyloxypropyl 、 Epoxycyclohexylmethyl, epoxycyclohexylethyl, epoxycyclohexylpropyl, glycidyloxyethyl, glycidyloxypropyl 、 Phenyl, methyl, ethyl, propyl, cyclohexylethyl.

[0013] Preferably, at least one of R 1 -R n Is methacryloyloxypropyl, and at least one of R 1 -R n Is epoxycyclohexylethyl, and at least one of R 1 -R n Is phenyl.

[0014] The preparation method of a kind of ladder-type polyhedral oligomeric silsesquioxane described above comprises the following steps:

[0015] After stirring and mixing water, catalyst and organic solvent evenly, add alkyl silane coupling agent, alkyl acryloyloxy silane coupling agent, epoxy group silane coupling agent under nitrogen atmosphere and at 20 - 60 °C, stir for 1 - 3 hours to ensure that the alkoxy groups of the silane coupling agent are completely hydrolyzed into silanol groups, then add trialkyl methoxysilane end-capping agent and continue to stir for 72 - 96 h, the purpose is to make the silanol groups completely condensed and completely consume the active sites of the unstable silanol groups at the ends, so as to obtain ladder-type polyhedral oligomeric silsesquioxane.

[0016] The above reaction process is as follows:

[0017]

[0018] Preferably, the alkylacryloxysilane coupling agent is a silane coupling agent containing three methoxy groups and one photoactive alkylacryloxy group, including at least one of methacryloxymethyltrimethoxysilane, methacryloxyethyltrimethoxysilane, methacryloxypropyltrimethoxysilane, ethylacryloxymethyltrimethoxysilane, ethylacryloxyethyltrimethoxysilane, and ethylacryloxypropyltrimethoxysilane;

[0019] Preferably, the epoxy group-containing silane coupling agent is a silane coupling agent containing three methoxy groups and one photoactive epoxy group, including at least one of epoxycyclohexylmethyltrimethoxysilane, epoxycyclohexylethyltrimethoxysilane, epoxycyclohexylpropyltrimethoxysilane, glycidoxyethyltrimethoxysilane, and glycidoxypropyltrimethoxysilane;

[0020] The alkylsilane coupling agent is a silane coupling agent containing three methoxy groups and one inert group, including any one of phenyltrimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, and cyclohexylethyltrimethoxysilane;

[0021] Preferably, the catalyst is an alkali metal salt, and the alkali metal salt is a carbonate, bicarbonate, or hydroxide. More preferably, potassium carbonate, potassium hydroxide, etc. are selected; the amount of water in the alkali solution is 3-9 times the total molar amount of methoxy groups added during the reaction, and the amount of the alkali metal salt is 1-2.5‰ of the total molar amount of methoxy groups added during the reaction;

[0022] Preferably, the organic solvent is an organic solvent that facilitates the mutual penetration of the oil-water interface, including one of benzene, toluene, tetrahydrofuran, dioxane, N-N'-dimethylformamide, dichloromethane, and 1,2-dichloroethane. The amount of the organic solvent added is such that the mass fraction of the catalyst is 1-3 wt%.

[0023] Preferably, the capping agent is trimethylmethoxysilane or triethylmethoxysilane.

[0024] Preferably, the molar ratio of the alkylsilane coupling agent, alkylacryloxysilane coupling agent, and epoxy group-containing silane coupling agent is 1:1:1-2.

[0025] Preferably, the molar ratio of the capping agent to the alkylsilane coupling agent is 2-3:1.

[0026] Preferably, after the reaction is completed, post-treatment including the following steps is also carried out:

[0027] (1) After the reaction, the temperature is raised to 30 - 40 °C, and low-boiling compounds are distilled off under reduced pressure, then cooled to room temperature;

[0028] (2) Add another low-boiling organic solvent for dissolution, and the amount of the organic solvent does not exceed 100 wt% of the total amount of the silane coupling agent; the silane coupling agent includes alkyl silane coupling agent, alkyl acryloyloxy silane coupling agent, and epoxy silane coupling agent;

[0029] (3) Wash with saturated brine until neutral, then dry over anhydrous MgSO 4 Dry, then centrifuge, filter by suction, and dry to obtain ladder-shaped polyhedral oligomeric silsesquioxane;

[0030] The another low-boiling organic solvent is dichloromethane or 1,2-dichloroethane;

[0031] The amount of the saturated brine added each time is 50 - 100% of the total volume of all the remaining materials.

[0032] Preferably, the desiccant used is anhydrous MgSO 4 Dry overnight (>8 hours) or place in a vacuum environment at 30 - 40 °C for drying >24 h.

[0033] The application of the above-mentioned ladder-shaped polyhedral oligomeric silsesquioxane in the preparation of a doubly curable ladder-shaped polyhedral oligomeric silsesquioxane coating.

[0034] Preferably, the above application includes the following steps:

[0035] First, mix the ladder-shaped polyhedral oligomeric silsesquioxane and the photoinitiator evenly, then coat on the surface of the substrate, and then place it under ultraviolet light for curing, that is, self-crosslinking to form a high-strength coating;

[0036] The photoinitiator is a cationic photoinitiator and / or a free radical photoinitiator.

[0037] Preferably, the cationic photoinitiator can be selected from triarylsulfonium salts, diaryliodonium salts, and in the present invention, triarylsulfonium hexafluoroantimonate is the best; the free radical photoinitiator can be selected from cleavage-type or H-abstraction-type photoinitiators, and in the present invention, it is preferred to use 2-isopropylthioxanthone and a composite photoinitiator together, such as 2-isopropylthioxanthone (ITX) and ethyl p-dimethylaminobenzoate (EDAB).

[0038] Preferably, the ultraviolet light irradiation is carried out under a 365 nm UV lamp.

[0039] Preferably, the ultraviolet light irradiation time is preferably 40 - 300 s.

[0040] Preferably, during free radical photocuring, the UV irradiation time of the coating is 60 - 100 s; during cationic photocuring, the UV irradiation time of the coating is 200 - 300 s; and during dual curing, the irradiation time is 200 - 240 s.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] (1) The present invention breaks the traditional method of acidic catalytic hydrolysis and then polymerization, adopts a basic catalyst, and can prepare ladder-shaped polyhedral oligomeric silsesquioxane under room temperature and mild reaction conditions.

[0043] (2) The ladder-shaped polyhedral oligomeric silsesquioxane of the present invention retains the inorganic Si - O - Si rigid main chain, providing it with excellent mechanical properties. At the same time, the variety of organic side group functional groups is enriched, bringing good adhesion to it.

[0044] (3) The present invention provides more selectable curing methods for the UV photocurable ladder-shaped polyhedral oligomeric silsesquioxane coating, which can meet the needs of different environments and application scenarios. Description of the Drawings

[0045] Figure 1 It is the FT-IR spectrogram of the ladder-shaped polyhedral oligomeric silsesquioxane obtained in Example 1.

[0046] Figure 2 It is the wide-angle X-ray diffraction pattern of the coating after cationic photocuring of the ladder-shaped polyhedral oligomeric silsesquioxane obtained in Example 1.

[0047] Figure 3 It is the ladder-shaped polyhedral oligomeric silsesquioxane obtained in Example 1 29 Si NMR spectrum. Detailed Embodiments

[0048] The present invention provides a preparation method of a dual-curable ladder-shaped polyhedral oligomeric silsesquioxane, which includes the following steps: (1) After adding water, a catalyst, and a solvent and stirring and mixing them evenly, add a trialkoxysilane coupling agent RSiY 3 Under a nitrogen atmosphere and at 20 - 60 °C, stir for 1 - 3 hours to ensure that the alkoxy groups of the silane coupling agent are completely hydrolyzed into silanol groups, and then add a capping agent T 3 SiY and continue stirring for 72 - 96 h. The purpose is to completely condense the silanol groups and completely consume the active sites of the unstable silanol groups at the ends, obtaining a capped ladder-shaped polyhedral oligomeric silsesquioxane mixture. Subsequently, the solvent is distilled out at 25 - 60 °C (this temperature depends on the specific type of solvent) through a vacuum distillation device, obtaining a viscous ladder-shaped polyhedral oligomeric silsesquioxane mixture.

[0049] The structure of the ladder-shaped polyhedral oligomeric silsesquioxane is as follows:

[0050]

[0051] Among them, n≥6, R 1 -R n are each independently selected from reactive functional groups (including methacryloxymethyl 、 methacryloxyethyl 、 methacryloxypropyl 、 ethylacryloxymethyl 、 ethylacryloxyethyl 、 ethylacryloxypropyl 、 epoxycyclohexylmethyl, epoxycyclohexylethyl, epoxycyclohexylpropyl, glycidyloxyethyl, glycidyloxypropyl, etc.) and inert functional groups (including phenyl, methyl, ethyl, propyl, cyclohexylethyl, etc.). Additionally, the end-capping functional group T 3 (including trimethyl, triethyl, etc.).

[0052] In the above method, the catalyst is selected from alkali metal salts (carbonates / bicarbonates). Preferably, potassium carbonate, sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, etc. are selected. More preferably, one of potassium carbonate and sodium carbonate is selected.

[0053] For the end-capping agent, preferably, trimethylmethoxysilane or triethylmethoxysilane is selected. Among them, trimethylmethoxysilane is more preferred.

[0054] (2) Dissolve the ladder-shaped polyhedral oligomeric silsesquioxane mixture in another low-boiling solvent with a density greater than that of water, wash the ladder-shaped polyhedral oligomeric silsesquioxane mixture with water, and dry it to obtain the ladder-shaped polyhedral oligomeric silsesquioxane.

[0055] Preferably, the silane coupling agent is selected from trimethoxysilane or triethoxysilane.

[0056] Preferably, the reactive functional group is selected from methacryloxymethyl 、 methacryloxyethyl 、 methacryloxypropyl 、 ethylacryloxymethyl 、 ethylacryloxyethyl 、 ethylacryloxypropyl 、 at least one of epoxycyclohexylmethyl, epoxycyclohexylethyl, epoxycyclohexylpropyl, glycidyloxyethyl, and glycidyloxypropyl. More preferably, one or two of methacryloxypropyl and epoxycyclohexylethyl are selected.

[0057] Preferably, the inert functional group is selected from at least one of methyl, ethyl, phenyl, and cyclohexylethyl. More preferably, one of phenyl and methyl is selected.

[0058] Preferably, the amount of water in the aqueous solution of the alkali metal salt catalyst is 3-9 times the total molar amount of methoxy groups added during the reaction, and the amount of the metal salt is 1-2.5‰ of the total molar amount of methoxy groups added during the reaction.

[0059] Preferably, the organic solvent added can be selected from one of benzene, toluene, tetrahydrofuran, dioxane, N-N'-dimethylformamide, 1,2-dichloromethane, and dichloroethane, and more preferably, one of tetrahydrofuran and dioxane. The mass of the added organic solvent is such that the mass fraction of the alkali metal catalyst is 1-3 wt%.

[0060] In the present invention, the stirring speed of the mixture of water, alkali metal, and organic solvent is preferably 100-200 rpm, more preferably 140-180 rpm, and the stirring speed during the subsequent continuous reaction time is the same as above.

[0061] In the present invention, the monomer feeding molar ratio of the three functional groups is input according to the functional group ratio required for the target product, and more preferably 1:1:1.

[0062] (3) Mix the prepared ladder-shaped polyhedral oligomeric silsesquioxane with a photoinitiator, and uniformly coat the above mixture on one side of the substrate using a coater, and place it under a 365 nm UV lamp for irradiation to obtain a ladder-shaped polyhedral oligomeric silsesquioxane coating.

[0063] Preferably, the cationic photoinitiator can be selected from triarylsulfonium salts and diaryliodonium salts, and in the present invention, triarylsulfonium hexafluoroantimonate is the most optimal; the radical photoinitiator can be selected from cleavage-type or hydrogen-abstraction-type photoinitiators, and in the present invention, it is preferred to use 2-isopropylthioxanthone and the coinitiators Irgacure369, Irgacure907, and EDAB together; in addition, during radical photocuring, the UV irradiation time of the coating can be completed in 60-100 s, and during cationic photocuring, 200-300 s is the best. When using the dual-curing method, the irradiation time can be completely cured in 150-240 s.

[0064] The following describes the technical solutions in the present invention clearly and completely in conjunction with the embodiments in the present invention. The described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0065] Example 1

[0066] Add H 2 O 10.79 g, K 2 CO 30.1965 g, 29.66 g of tetrahydrofuran, stirred at 25°C until the mixture was uniform, and then a mixture containing 19.82 g of phenyltrimethoxysilane, 24.88 g of methacryloxypropyltrimethoxysilane, and 24.64 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added dropwise to N 2 The flask was placed in an atmosphere at 25°C and subjected to hydrolysis and polycondensation at 170 rpm for 1 hour to complete the reaction of the silyl methoxy groups in the monomer.

[0067] 20.84 g of trimethylmethoxysilane was injected through a syringe to cap the unstable Si-OH at the end of the ladder-like polymer long chain in the reaction system, and the above reaction conditions were maintained and stirred for 95 hours.

[0068] After the reaction is completed, the temperature of the transparent liquid polysiloxane obtained by the reaction is raised to 30° C., and the solvent tetrahydrofuran is removed by reduced pressure distillation with the vacuum degree gradually increased to -0.095 MPa through a vacuum distillation apparatus equipped with a T-tube, a condenser, a tail pipe, a safety bottle, a cold trap, and a circulating water vacuum pump, and the vacuum degree is gradually increased to -0.095 MPa to obtain a viscous trapezoidal polysilsesquioxane, which is stored in a separatory funnel containing 39.91 g (about 30 ml) of dichloromethane, and extracted 5 times with saturated brine, each time adding about 100 ml of saturated brine, extracting the alkali salt to neutrality, separating the liquids, taking the lower oil layer and placing it on 9.7 g of anhydrous magnesium sulfate to dry, and drying overnight until the anhydrous magnesium sulfate no longer releases heat and agglomerates to ensure that the trapezoidal polysilsesquioxane remains anhydrous.

[0069] The dried trapezoidal polysilsesquioxane was placed in a 100 ml flask and subjected to reduced pressure distillation at 30°C (the apparatus and vacuum degree are the same as above) to remove most of the solvent dichloromethane, and then placed in a vacuum drying oven at 40°C for two days to ensure that the solvent evaporated completely, and finally a dual-curable trapezoidal polysilsesquioxane was obtained.

[0070] The horizontal and vertical bonds of Si-O-Si in the dual-curable ladder polysilsesquioxane are respectively Figure 1 1035cm in FT-IR spectrum -1 and 1120cm -1 ; The X-ray wide-angle diffraction (2-60°) image of trapezoidal polysilsesquioxane after cationic light curing is shown in Figure 2 , where the molecular inorganic Si-O-Si skeleton chain-to-chain distance is attributed to 2θ = 26.00°, and the average thickness of the inorganic Si-O-Si skeleton is attributed to 2θ = 22.84°; the dual-curable ladder polysilsesquioxane 29 SiNMR spectrum Figure 3 , where the single peak at -109 ppm represents the fully condensed T 3In summary, it represents the formation of a ladder structure and the existence of a fully condensed ladder structure.

[0071] 3.2746g of dual-curable trapezoidal polysilsesquioxane was added to 0.0833g of triarylsulfonium hexafluoroantimonate and stirred to make it evenly mixed, and then the mixture was coated on PET and polished tinplate using a four-sided preparation device. The coating thickness was 60μm, and then it was placed under a 365nm UV lamp for 240s to ensure complete curing. After curing, the pencil hardness was measured to be 5H (PET) and 6H (tinplate), and the coating adhesion was level 3 (PET) and level 4 (tinplate). The test met the international standards ISO15184:1998 and ISO2420:1998.

[0072] Table 1

[0073]

[0074] Example 2

[0075] In a 250 ml three-necked flask, add H 2 O 10.86g, K 2 CO 3 0.1957 g, 29.66 g of tetrahydrofuran, stirred at 25°C until the mixture was uniform, and then a mixture containing 19.86 g of phenyltrimethoxysilane, 24.87 g of methacryloxypropyltrimethoxysilane, and 24.63 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added dropwise to N 2 The flask was placed in an atmosphere at 26° C. and subjected to hydrolysis and polycondensation for 1 h at a rotation speed of 170 rpm to complete the reaction of the silyl methoxy groups in the monomer.

[0076] 18.88 g of trimethylmethoxysilane was injected into the reaction system via a syringe to cap the unstable Si-OH at the end of the ladder-like polymer long chain, and the above reaction conditions were maintained and stirred for 95 hours.

[0077] After the reaction is completed, the temperature of the transparent liquid polysiloxane obtained by the reaction is raised to 30° C., and passed through a vacuum distillation apparatus equipped with a T-tube, a condenser, a tail pipe, a safety bottle, a cold trap, and a circulating water vacuum pump, and the vacuum degree is gradually increased to -0.095 MPa to remove the solvent tetrahydrofuran by vacuum distillation to obtain a viscous trapezoidal polysilsesquioxane, which is then stored in a separatory funnel containing 20.01 g (about 16 ml) of 1,2-dichloroethane, and extracted with saturated brine 5 times, each time adding about 100 ml of saturated brine, after extraction to neutrality, the liquid is separated, the lower oil layer is taken and placed on 10.03 g of anhydrous magnesium sulfate to dry for 8 hours, until the anhydrous magnesium sulfate no longer releases heat and agglomerates, to ensure that the trapezoidal polysilsesquioxane remains anhydrous and dry.

[0078] Put the dry ladder-shaped polysilsesquioxane into a 100 ml flask and carry out vacuum distillation at 55 °C (the device and vacuum degree are the same as above) to remove most of the solvent 1,2-dichloroethane. Then put it into a vacuum drying oven at 55 °C for two days to ensure that the solvent evaporates completely, and finally obtain the ladder-shaped polysilsesquioxane that can be doubly cured.

[0079] Take a small amount of the doubly curable ladder-shaped polysilsesquioxane and add it to a small amount of free radical photoinitiator (the preparation is shown in Table 2 below), stir to make it evenly mixed, and then use a four-sided coater to coat the mixture on PET and the polished tinplate. The film thickness is 60 μm, and then irradiate it under a 365 nm UV lamp for 120 s to ensure complete curing. After curing, the pencil hardness is measured as 2H (PET) and 3H (tinplate), and the coating adhesion is grade three. The test complies with the international standards ISO15184:1998 and ISO2420:1998.

[0080] Table 2

[0081]

[0082] Example 3

[0083] Add 10.80 g of H 2 O, 0.1954 g of K 2 CO 3 , and 29.68 g of tetrahydrofuran into a 250 ml three-necked flask. After stirring evenly at 30 °C, dropwise add a mixture containing 19.85 g of phenyltrimethoxysilane, 24.87 g of methacryloxypropyltrimethoxysilane, and 24.73 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane into the flask under N 2 atmosphere and place it in an environment at 25 °C and continuously carry out hydrolysis and polycondensation at a rotation speed of 170 rpm for 1 h to make the silicon methoxy groups in the monomers react completely.

[0084] Inject 20.83 g of trimethylmethoxysilane into the reaction system through a syringe to cap the unstable Si-OH at the end of the ladder-shaped polymer chain, and continuously maintain the above reaction conditions and stir the reaction for 95 h.

[0085] After the reaction, the resulting transparent liquid polysiloxane was heated to 30 °C, and then subjected to vacuum distillation using a distillation apparatus equipped with a T-tube, a condenser, an adapter, a safety bottle, a cold trap, and a circulating water vacuum pump. The vacuum was gradually increased to -0.095 Mpa to remove the solvent tetrahydrofuran, resulting in a viscous ladder-type polyhedral oligomeric silsesquioxane. The product was stored in a separatory funnel containing 20.33 g (about 16 ml) of 1,2-dichloroethane. It was extracted 5 times with saturated brine, approximately 100 ml of saturated brine was added each time. After extraction until neutral, the layers were separated, and the lower oil layer was placed on 10.00 g of anhydrous magnesium sulfate and dried for 10 hours until the anhydrous magnesium sulfate no longer released heat or formed lumps, ensuring that the ladder-type polyhedral oligomeric silsesquioxane remained anhydrous and dry.

[0086] The dried ladder-type polyhedral oligomeric silsesquioxane was placed in a 100 ml flask and subjected to vacuum distillation at 55 °C (using the same apparatus and vacuum as above) to remove most of the solvent 1,2-dichloroethane. Then it was placed in a vacuum drying oven at 55 °C for two days to ensure complete evaporation of the solvent, finally obtaining a doubly curable ladder-type polyhedral oligomeric silsesquioxane.

[0087] 3.0583 g of the doubly curable ladder-type polyhedral oligomeric silsesquioxane was added to a mixture containing 0.0314 g of EDAB, 0.0313 g of ITX, and 0.0989 g of triarylsulfonium hexafluoroantimonate, and stirred to mix evenly. Subsequently, the mixture was coated on PET and polished tinplate using a four-sided coater. The coating thickness was 60 μm, and then it was irradiated under a 365 nm UV lamp for 300 s to ensure complete curing. After curing, the pencil hardness was measured to be 4H (PET) and 5H (tinplate), and the coating adhesion was grade 0. The test met the international standards ISO15184:1998 and ISO2420:1998.

[0088] Table 3

[0089]

[0090] Example 4

[0091] In a 250 ml three-necked flask, 10.84 g of H 2 O, 0.1957 g of K 2 CO 3 , and 29.88 g of tetrahydrofuran were added. After stirring evenly at 25 °C, a mixture containing 19.83 g of phenyltrimethoxysilane, 24.85 g of methacryloxypropyltrimethoxysilane, and 24.77 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added dropwise to the flask under N 2 atmosphere. The flask was placed in an environment at 25 °C and continuously hydrolyzed and polycondensed at a rotation speed of 170 rpm for 1 h to ensure complete reaction of the silicon methoxy groups in the monomers.

[0092] 20.80 g of trimethylmethoxysilane was injected into the reaction system via a syringe to cap the unstable Si-OH at the end of the ladder-like polymer long chain, and the above reaction conditions were maintained and stirred for 95 hours.

[0093] After the reaction is completed, the temperature of the transparent liquid polysiloxane obtained by the reaction is raised to 30° C., and passed through a vacuum distillation apparatus equipped with a T-tube, a condenser, a tail pipe, a safety bottle, a cold trap, and a circulating water vacuum pump, and the vacuum degree is gradually increased to -0.095 MPa to remove the solvent tetrahydrofuran by vacuum distillation to obtain a viscous trapezoidal polysilsesquioxane, which is then stored in a separatory funnel containing 39.88 g (about 30 ml) of dichloromethane, and extracted with saturated brine 4 times, each time adding about 100 ml of saturated brine, after extraction to neutrality, the liquid is separated, the lower oil layer is taken and placed on 9.5 g of anhydrous magnesium sulfate for drying for 8 hours, until the anhydrous magnesium sulfate no longer releases heat and agglomerates, to ensure that the trapezoidal polysilsesquioxane remains anhydrous and dry.

[0094] The dried trapezoidal polysilsesquioxane was placed in a 100 ml flask and subjected to reduced pressure distillation at 25° C. (the apparatus and vacuum degree are the same as above) to remove most of the solvent dichloromethane, and then placed in a vacuum drying oven at 30° C. for two days to ensure complete evaporation of the solvent, thereby finally obtaining a dual-curable trapezoidal polysilsesquioxane.

[0095] 3.0482g of dual-curable trapezoidal polysilsesquioxane was added to a mixture containing 0.0286g EDAB, 0.0278g ITX and 0.0960g triarylsulfonium hexafluoroantimonate and stirred to make it uniformly mixed, and then the mixture was coated on PET and polished tinplate using a four-sided preparation device. The coating thickness was 60μm, and then it was placed under a 365nm UV lamp for 180s to ensure complete curing. After curing, the pencil hardness was measured to be 5H (PET), 6H (tinplate), and the coating adhesion was level 0. The test met the international standards ISO15184:1998 and ISO2420:1998.

[0096] Table 4

[0097]

[0098] 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 other changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A ladder-shaped polysilsesquioxane, characterized in that: The general structure is as follows: Among them, n≥6; R1-R n Each of the following is independently selected from an alkyl acryloyloxy group, an epoxy group or an alkyl group; At the same time R1-R n At least one of them is a methacryloyloxymethyl 、 Methacryloyloxyethyl 、 Methacryloyloxypropyl 、 Ethyl acryloyloxymethyl 、 Ethyl acryloyloxyethyl 、 Ethyl acryloyloxypropyl; at the same time R1-R n At least one of them is epoxycyclohexylmethyl, epoxycyclohexylethyl, epoxycyclohexylpropyl, glycidyloxyethyl, glycidyloxypropyl; and R1-R n At least one of them is phenyl, methyl, ethyl, propyl, or cyclohexylethyl; T3 is trimethyl or triethyl.

2. A ladder-shaped polysilsesquioxane according to claim 1, characterized in that: R1-R n At least one of them is a methacryloyloxypropyl group, R1-R n At least one of them is epoxycyclohexylethyl, R1-R n At least one of them is phenyl.

3. A method for preparing a ladder-shaped polysilsesquioxane according to claim 1 or 2, characterized in that: The following steps are involved: After stirring and mixing water, catalyst and organic solvent evenly, add alkyl silane coupling agent, alkyl acryloxy silane coupling agent and epoxy silane coupling agent under nitrogen atmosphere and 20-60°C, stir for 1-3 hours to ensure that the alkoxy group of the silane coupling agent is completely hydrolyzed into silanol group, then add trialkyl methoxy silane end-capping agent and continue stirring for 72-96 hours, in order to completely condense the silanol group and completely consume the unstable silanol active sites at the end to obtain ladder-shaped polysilsesquioxane.

4. The preparation method according to claim 3, characterized in that: The catalyst is an alkali metal salt, and the alkali metal salt is a carbonate, a bicarbonate or a hydroxide; the amount of the alkali metal salt is 1-2.5‰ of the total molar amount of the methoxy group added during the reaction; The organic solvent is an organic solvent that is conducive to the mutual penetration of the oil-water interface, including one of benzene, toluene, tetrahydrofuran, dioxane, N-N'-dimethylformamide, dichloromethane, and 1,2-dichloroethane, and the amount of the organic solvent added is such that the mass fraction of the catalyst is 1-3wt%; The alkyl acryloxy silane coupling agent is a silane coupling agent containing three methoxy groups and one photoactive alkyl acryloxy group, including any one of methacryloxymethyl trimethoxy silane, methacryloxyethyl trimethoxy silane, methacryloxypropyl trimethoxy silane, ethyl acryloxymethyl trimethoxy silane, ethyl acryloxyethyl trimethoxy silane, and ethyl acryloxypropyl trimethoxy silane; The epoxysilane coupling agent is a silane coupling agent containing three methoxy groups and one photoactive epoxy group, including any one of epoxycyclohexylmethyltrimethoxysilane, epoxycyclohexylethyltrimethoxysilane, epoxycyclohexylpropyltrimethoxysilane, glycidyloxyethyltrimethoxysilane, and glycidyloxypropyltrimethoxysilane; The alkylsilane coupling agent is a silane coupling agent containing three methoxy groups and one inert group, including any one of phenyltrimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane and cyclohexylethyltrimethoxysilane; The end-capping agent is trimethylmethoxysilane or triethylmethoxysilane; The molar ratio of the alkyl silane coupling agent, the alkyl acryloxy silane coupling agent and the epoxy silane coupling agent is 1:1:1-2; The molar ratio of the end-capping agent to the alkylsilane coupling agent is 2-3:

1.

5. The preparation method according to claim 3, characterized in that: After the reaction is completed, a post-treatment comprising the following steps is also performed: (1) After the reaction, the temperature is raised to 30-40°C, low boiling point compounds are evaporated under reduced pressure, and the mixture is cooled to room temperature; (2) adding another low-boiling point organic solvent to dissolve, wherein the amount of the organic solvent does not exceed 100 wt% of the total amount of the silane coupling agent; the silane coupling agent includes an alkyl silane coupling agent, an alkyl acryloxy silane coupling agent, and an epoxy silane coupling agent; (3) washing with saturated brine until neutral, then drying, centrifuging, filtering, and drying to obtain a ladder-shaped polysilsesquioxane; The other low-boiling organic solvent is dichloromethane or 1,2-dichloroethane; The amount of the saturated salt water added each time is 50-100% of the total volume of all remaining materials.

6. Use of the ladder-shaped polysilsesquioxane according to claim 1 or 2 in preparing a dual-curable ladder-shaped polysilsesquioxane coating.

7. Use of a trapezoidal polysilsesquioxane according to claim 6 in preparing a dual-curable trapezoidal polysilsesquioxane coating, characterized in that: The following steps are involved: Firstly, the ladder-shaped polysilsesquioxane is mixed with a photoinitiator and then coated on the surface of a substrate, and then cured under ultraviolet light, i.e., self-crosslinked to form a high-strength coating; The photoinitiator is a cationic photoinitiator and / or a free radical photoinitiator.

8. Use of a trapezoidal polysilsesquioxane according to claim 7 in preparing a dual-curable trapezoidal polysilsesquioxane coating, characterized in that: The cationic photoinitiator is a triarylsulfonium salt or a diaryliodonium salt; the free radical photoinitiator is a cleavage type or H abstraction type photoinitiator.

9. Use of a trapezoidal polysilsesquioxane according to claim 8 in preparing a dual-curable trapezoidal polysilsesquioxane coating, characterized in that: The cationic photoinitiator is triarylsulfonium hexafluoroantimonate; the free radical photoinitiator is one or more of 2-isopropylthioxanthone and ethyl p-dimethylaminobenzoate.

10. Use of a trapezoidal polysilsesquioxane according to claim 7 in preparing a dual-curable trapezoidal polysilsesquioxane coating, characterized in that: The UV irradiation time of the coating is 60-100s in free radical light curing, 200-300s in cationic light curing, and 150-240s in dual curing.

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