Silicon-containing chain acrylic liquid crystal photosensitive resin and preparation method thereof

Abstract

This invention provides a silicon-chain acrylic liquid crystal photosensitive resin and its preparation method. A compound containing mesocrystalline units with -OH terminals, EHC, and catalyst 1 are mixed and reacted to obtain solution A. NaOH is added dropwise to solution A to remove the water generated in the reaction. After continuing the reaction, the product is filtered, and excess EHC is removed from the filtrate to obtain solution B. Solution B is mixed with methanol / acetone, and the resulting crystals are washed, filtered, and dried to obtain liquid crystal epoxy resin C. C is mixed with an inhibitor and reacted, then acrylic acid and catalyst 2 are added dropwise to react and obtain acrylic liquid crystal photosensitive resin D. D is mixed with 1,1',3,3'-dimethyldisiloxane, and a solvent, catalyst 3, and inhibitor are added to carry out a hydrosilylation reaction to obtain silicon-chain acrylic liquid crystal photosensitive resin E. The silicon-chain acrylic liquid crystal photosensitive resin provided by this invention can be widely used in artificial muscles, actuators, shape memory, smart devices, and some highly elastic advanced composite materials.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet curable materials technology, and in particular to a silicon-chain acrylic liquid crystal photosensitive resin and its preparation method. Background Technology

[0002] In recent years, with countries worldwide placing increasing emphasis on energy conservation, emission reduction, environmental friendliness, continuous improvement of production efficiency, and higher performance requirements, ultraviolet (UV) curing technology has seen widespread application and significant development. UV curing technology refers to the process by which liquid oligomer systems (including monomers) undergo cross-linking polymerization to form solid products under the irradiation of UV or visible light of appropriate wavelengths and intensities. Currently, the most commonly used photosensitive resins are acrylic and epoxy resins, but they suffer from poor curing shrinkage and high brittleness. Therefore, developing a high-performance photosensitive resin is of profound significance.

[0003] Liquid crystal polymers are polymers that can exist as a liquid crystal phase under certain conditions. Compared with polymeric compounds, they possess the unique molecular orientation and positional order of liquid crystal phases; compared with small-molecule liquid crystal compounds, they also have high relative molecular mass and the characteristics of polymeric compounds. The organic combination of high relative molecular mass and liquid crystal phase endows liquid crystal polymers with distinct personalities and characteristics. Acrylic liquid crystal photosensitive resins combine the advantages of both, possessing good photocuring processability, good photoelectric properties, and their liquid crystal phase transition temperature can be designed and adjusted by changing the side chain molecular structure. More importantly, their liquid crystal units readily undergo large-scale reversible molecular orientation under light or magnetic fields, thus endowing them with special photoelectric properties, making them highly promising for applications in information storage and gas chromatography analysis.

[0004] The main chain of organosilicon materials is composed of Si-O-Si segments, while the side chains are connected to other organic groups through silicon atoms. Introducing silicon-containing segments into polymers can increase their flexibility, low-temperature resistance, and wear resistance.

[0005] Therefore, by copolymerizing organosilicon materials with acrylic liquid crystal photosensitive resin, organosilicon, which contains Si-O bonds with long bond lengths and high bond energies, and Si-C bonds with extremely high thermal stability, can be used as a toughening modifier for acrylic liquid crystal photosensitive resin, thereby achieving the goal of simultaneously improving the toughness, mechanical properties, and thermal properties of the modified resin. Summary of the Invention

[0006] In view of the limitations and shortcomings of existing technologies, the present invention aims to provide a high-performance, simple-to-synthesize silicon-chain acrylic liquid crystal photosensitive resin and its preparation method. The silicon-chain acrylic liquid crystal photosensitive resin provided by the present invention retains the advantages of both the ordered liquid crystal structure and network crosslinking inherent in acrylic liquid crystal photosensitive resins. Simultaneously, the silicon-oxygen chains possess unique inherent conformational flexibility, enhancing the resin's toughness. The introduction of silicon chains allows acrylic liquid crystal polymers with low crosslinking density to interconvert between isotropic and anisotropic liquid crystal phases, simultaneously possessing both the anisotropy of liquid crystals and the entropic elasticity of polymer networks.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a silicon-chain acrylic liquid crystal photosensitive resin includes the following steps:

[0009] (1) Mix 10 parts of a compound containing mesocrystalline units and with -OH at the ends, 50 to 500 parts of epichlorohydrin (EHC) and 0.1 to 1.0 parts of catalyst 1 according to a molar ratio, introduce N2 for protection, and then react at 40 to 100°C for 5 to 24 hours to obtain solution A;

[0010] (2) Add 20-50 parts of NaOH solution (concentration 30%-60%) slowly to solution A using a molar meter. Remove the water generated by the reaction by vacuum pump under reduced pressure. After continuing the reaction for 0.1-4 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC from the filtrate to obtain solution B.

[0011] (3) Mix solution B with methanol / acetone solution (volume ratio 1.0:0.1 to 1.0:10), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 60 to 100°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0012] (4) Take 10 parts of liquid crystal epoxy resin C and 0.1 to 1.0 parts of polymerization inhibitor by molar, add them to a flask, and set the reaction temperature to 90 to 150°C; after the epoxy resin C has completely melted, slowly add 20 to 25 parts of acrylic acid and add 0.01 to 0.1 parts of catalyst 2; react for 0.5 to 5.0 hours, and after cooling, a light yellow viscous resin is obtained, namely acrylic liquid crystal photosensitive resin D;

[0013] (5) According to a molar ratio, 20 parts of acrylic liquid crystal photosensitive resin D and 0.1-1.0 parts of polymerization inhibitor are mixed, and then an organic solvent and 0.01-0.1 parts of catalyst 3 are added; the reaction temperature is set to 30-80℃, and after the acrylic liquid crystal photosensitive resin D is completely dissolved, 5-10 parts of 1,1',3,3'-dimethyldisiloxane are added dropwise and reacted for 2-5 hours to obtain a silicon chain acrylic liquid crystal photosensitive resin E, the structural formula of which is:

[0014]

[0015] Preferably, the compound containing a mesocrystalline unit and having an -OH terminal is one or a combination of 4-hydroxyphenyl 4-hydroxybenzoate, 4,4′-biphenyl, 3,3',5,5'-tetramethylbiphenyl, 4-((4-hydroxyphenoxy)carbonyl)phenyl 4-hydroxybenzoate, 2,3-bis(4-hydroxyphenyl)acrylonitrile, and 4,4'-propylene bisphenol.

[0016] Preferably, the catalyst 1 in step (1) is one or a combination of tetramethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride.

[0017] Preferably, the polymerization inhibitor mentioned in step (4) is one or a combination of hydroquinone, benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone.

[0018] Preferably, the catalyst 2 in step (4) is one or a combination of N,N-diethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine, and N,N'-diethylpiperazine.

[0019] Preferably, the polymerization inhibitor in step (5) is one or a combination of hydroquinone, benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone; the organic solvent is one or a combination of acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate, or acetonitrile; and the catalyst 3 is one or a combination of platinum chloric acid and Karstedt catalyst.

[0020] Compared with existing technologies, the beneficial effects of this invention are: the synthesis process of the silicon-chain acrylic liquid crystal photosensitive resin provided by this invention is simple, and it has good soft elasticity, making it suitable for large-scale production and application. The molecular structure of the silicon-chain liquid crystal acrylic liquid crystal photosensitive resin not only contains a large number of rigid mesocrystalline units, but also generates anisotropic mesocrystalline domains in situ during molding, which can play a self-reinforcing role during curing. Simultaneously, the grafted organosilicon segments expand the crosslinking density of the molecular network, resulting in excellent heat resistance, low dimensional shrinkage, and the anisotropy of liquid crystals and entropic elasticity of polymer networks. It has broad application potential in cutting-edge industries such as soft robotics, bionics, actuators, shape memory, and intelligent devices. Attached Figure Description

[0021] Figure 1 This refers to the reaction involved in the preparation method of the silicon-chain acrylic liquid crystal photosensitive resin of the present invention.

[0022] Figure 2 These are the Fourier Transform Infrared (FTIR) spectra of the acrylic liquid crystal photosensitive resin and the silicon-chain acrylic liquid crystal photosensitive resin in Example 1; wherein, D is the acrylic liquid crystal photosensitive resin and E is the silicon-chain acrylic liquid crystal photosensitive resin.

[0023] Figure 3 The nuclear magnetic resonance (NMR) spectrum of the silicon-chain acrylic liquid crystal photosensitive resin in Example 1 is shown in the figure. 1 H-NMR). Detailed Implementation

[0024] Example 1

[0025] (1) 23.0g of 4-hydroxyphenyl 4-hydroxybenzoate, 230ml of epichlorohydrin (EHC) and 0.5g of tetramethylammonium chloride were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 60℃ for 12 hours to obtain solution A.

[0026] (2) Then slowly add NaOH solution (0.25 mol, concentration 45%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 0.5 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0027] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:1.0), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 60°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0028] (4) Take 19.3g (0.05mol) of liquid crystal epoxy resin C and 0.15g of hydroquinone, add them to a flask, and set the reaction temperature to 110℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.9g (0.11mol) of acrylic acid and 0.06g of N,N-diethylaniline. After reacting for 2.5 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0029] (5) Take 25.2g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.01g chloroplatinic acid and 50ml acetone, add them to a flask, set the reaction temperature to 60℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 3.35g (0.025mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 3 hours to obtain acrylic liquid crystal photosensitive resin E containing silicon chains.

[0030] See appendix Figure 2 This is the Fourier Transform Infrared (FTIR) spectrum of the silicon-chain acrylic liquid crystal photosensitive resin (E) prepared in Example 1 of this invention. E is at 10¹⁰.⁵⁰ cm⁻¹. -1 An absorption peak for the Si-O bond antisymmetric stretching vibration appeared at 817.68 cm⁻¹. -1 The absorption peak at this point is the absorption peak of the symmetric stretching vibration of the Si-O bond. This indicates that the silicon-chain acrylic liquid crystal photosensitive resin was successfully synthesized.

[0031] See appendix Figure 3 It is the 1H NMR spectrum of the silicon-chain acrylic liquid crystal photosensitive resin prepared in Example 1 of this invention. 1 (H-NMR). The four hydrogen proton peaks of the mesocrystalline benzene ring correspond to four characteristic peaks in the range of 8.3–6.7 ppm, indicating that the structure of the mesocrystalline unit was not destroyed. The characteristic hydrogen proton peaks on the side chain are located in the range of 3.7–4.4 ppm, the characteristic hydrogen proton peaks of the carbon-carbon double bond are located at 6.5 and 5.7 ppm, and the hydrogen proton peaks at both ends of the silicon chain are located in the range of 1.1–2.0 ppm.

[0032] The prepared silicon-chain acrylic liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 69HD, and a notched impact strength of 4.93 KJ / m². 2 .

[0033] Example 2

[0034] (1) 0.1 mol of 4,4′-biphenyl, 360 ml of epichlorohydrin (EHC) and 0.003 mol of tetrabutylammonium bromide were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 50 °C for 18 hours to obtain solution A.

[0035] (2) Then slowly add NaOH solution (0.30 mol, concentration 40%) to solution A. Remove the water generated by the reaction by vacuum pump under reduced pressure. After the reaction continues for 2.5 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0036] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:3.0), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 80°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0037] (4) Take 14.9g (0.05mol) of liquid crystal epoxy resin C and 0.25g of benzoquinone, add them to a flask, and set the reaction temperature to 140℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.9g (0.11mol) of acrylic acid and 0.08g of N,N-dimethyl-p-toluidine. After reacting for 4.0 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0038] (5) Take 20.8g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml dichloroethane, add them to a flask, set the reaction temperature to 70℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 4 hours to obtain silicon chain acrylic liquid crystal photosensitive resin E.

[0039] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 74HD, and an impact strength of 4.76 KJ / m². 2 .

[0040] Example 3

[0041] (1) 0.1 mol of 3,3',5,5'-tetramethylbiphenyl, 120 ml of epichlorohydrin (EHC) and 0.006 mol of tetrabutylammonium chloride were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 80 °C for 6 hours to obtain solution A.

[0042] (2) Then slowly add NaOH solution (0.20 mol, concentration 60%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 4.0 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0043] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:0.5), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 100°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0044] (4) Take 17.5g (0.05mol) of liquid crystal epoxy resin C and 0.30g of methyl hydroquinone, add them to a flask, and set the reaction temperature to 120℃. After the liquid crystal epoxy resin C is completely melted, slowly add 8.6g (0.12mol) of acrylic acid and 0.04g of N,N-dimethylcyclohexylamine. After reacting for 5.0 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0045] (5) Take 23.4g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml dichloroethane, add them to a flask, set the reaction temperature to 70℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 4 hours to obtain silicon chain acrylic liquid crystal photosensitive resin E.

[0046] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 68 HD, and an impact strength of 5.12 KJ / m². 2 .

[0047] Example 4

[0048] (1) 0.1 mol of 4-((4-hydroxyphenoxy)carbonyl)phenyl 4-hydroxybenzoate, 1050 ml of epichlorohydrin (EHC) and 0.01 mol of tetraethylammonium bromide were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 100 °C for 24 hours to obtain solution A.

[0049] (2) Then slowly add NaOH solution (0.40 mol, concentration 50%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 0.5 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0050] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:5.0), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 80°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0051] (4) Take 23.1g (0.05mol) of liquid crystal epoxy resin C and 0.25g of 2-tert-butylhydroquinone, add them to a flask, and set the reaction temperature to 150℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.2g (0.10mol) of acrylic acid and 0.10g of N,N-diethylaniline. After reacting for 1.0 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0052] (5) Take 29g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml acetone, add them to a flask, set the reaction temperature to 50℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 2 hours to obtain acrylic liquid crystal photosensitive resin E containing silicon chains.

[0053] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 72 HD, and an impact strength of 4.99 KJ / m². 2 .

[0054] Example 5

[0055] (1) 0.1 mol of 2,3-bis(4-hydroxyphenyl)acrylonitrile, 950 ml of epichlorohydrin (EHC) and 0.001 mol of tetrabutylammonium hydrogen sulfate were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 40 °C for 10 hours to obtain solution A.

[0056] (2) Then slowly add NaOH solution (0.30 mol, concentration 60%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 3.0 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0057] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:10), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 90°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0058] (4) Take 17.5g (0.05mol) of liquid crystal epoxy resin C and 0.10g of 2,5-di-tert-butylhydroquinone, add them to a flask, and set the reaction temperature to 100℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.9g (0.11mol) of acrylic acid and 0.02g of N,N-dimethylbenzylamine. After reacting for 3.5 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0059] (5) Take 23.4g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml dichloroethane, add them to a flask, set the reaction temperature to 80℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 4 hours to obtain acrylic liquid crystal photosensitive resin E containing silicon chains.

[0060] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 70 HD, and an impact strength of 4.82 KJ / m². 2 .

[0061] Example 6

[0062] (1) 0.1 mol of 2,3-bis(4-hydroxyphenyl)acrylonitrile, 950 ml of epichlorohydrin (EHC) and 0.001 mol of tetrabutylammonium hydrogen sulfate were mixed as raw materials, N2 was introduced for protection, and then the mixture was reacted at 40 °C for 10 hours to obtain solution A.

[0063] (2) Then slowly add NaOH solution (0.30 mol, concentration 60%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 3.0 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0064] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:10), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 90°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0065] (4) Take 17.5g (0.05mol) of liquid crystal epoxy resin C and 0.10g of 2,5-di-tert-butylhydroquinone, add them to a flask, and set the reaction temperature to 100℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.9g (0.11mol) of acrylic acid and 0.02g of N,N-dimethylbenzylamine. After reacting for 3.5 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0066] (5) Take 24.3g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml dichloroethane, add them to a flask, set the reaction temperature to 65℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 3 hours to obtain silicon chain acrylic liquid crystal photosensitive resin E.

[0067] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 74HD, and an impact strength of 4.56 KJ / m². 2 .

[0068] Example 7

[0069] (1) Mix 0.1 mol of 4,4'-propenebisphenol, 120 ml of epichlorohydrin (EHC) and 0.002 mol of benzyltriethylammonium chloride as raw materials, introduce N2 for protection, and then react at 60 °C for 12 hours to obtain solution A.

[0070] (2) Then slowly add NaOH solution (0.20 mol, concentration 45%) to solution A. Remove the water generated by the reaction by vacuum pump. After the reaction continues for 1.0 hours, pour the product into a separatory funnel, filter to remove NaCl, and use a rotary evaporator to remove excess EHC to obtain solution B.

[0071] (3) Mix solution B with methanol / acetone solution (volume ratio of 1.0:3.5), place in a refrigerator to cool and crystallize, wash the obtained crystals with methanol and filter, dry the product in an oven at 80°C, and obtain a milky white solid, which is liquid crystal epoxy resin C.

[0072] (4) Take 16.9g (0.05mol) of liquid crystal epoxy resin C and 0.15g of hydroquinone, add them to a flask, and set the reaction temperature to 110℃. After the liquid crystal epoxy resin C is completely melted, slowly add 7.9g (0.11mol) of acrylic acid and 0.06g of N,N'-diethylpiperazine. After reacting for 0.5 hours, discharge the material and cool it to obtain a light yellow viscous resin, namely acrylic liquid crystal photosensitive resin D.

[0073] (5) Take 22.8g (0.05mol) acrylic liquid crystal photosensitive resin D, 0.15g hydroquinone, 0.05g of prepared Karstedt catalyst and 50ml dichloroethane, add them to a flask, set the reaction temperature to 70℃, and after acrylic liquid crystal photosensitive resin D is completely dissolved, add 2.68g (0.02mol) 1,1',3,3'-dimethyldisiloxane dropwise and react for 4 hours to obtain acrylic liquid crystal photosensitive resin E containing silicon chains.

[0074] The prepared silicon-containing liquid crystal photosensitive resin was uniformly coated onto a glass slide, and then subjected to 365nm ultraviolet light (100mW / cm²). 2 The resin was treated with UV curing under irradiation. The prepared resin was poured into a mold, and after complete UV curing, the product had a smooth surface, a Shore hardness of 68 HD, and an impact strength of 4.47 KJ / m². 2 .

Claims

1. A method for preparing a silicon-containing chain acrylate liquid crystal photosensitive resin, characterized by Includes the following steps: (1) Mix 10 parts of a compound containing mesocrystalline units and with -OH at the ends, 50 to 500 parts of epichlorohydrin and 0.1 to 1.0 parts of catalyst 1 according to molar ratio, introduce N2 for protection, and then react at 40 to 100°C for 5 to 24 hours to obtain solution A; (2) Add 20-50 parts of NaOH solution to solution A slowly using a molar meter. Remove the water generated by the reaction by vacuum pump under reduced pressure. Continue the reaction for 0.1-4 hours, then pour the product into a separatory funnel and filter to remove NaCl. Use a rotary evaporator to remove excess epichlorohydrin from the filtrate to obtain solution B. (3) Mix solution B with methanol / acetone solution, place in a refrigerator to cool and crystallize, wash the crystals with methanol and filter, dry the product to obtain liquid crystal epoxy resin C. (4) Take 10 parts of liquid crystal epoxy resin C and 0.1 to 1.0 parts of polymerization inhibitor by molar, add them to a flask, and set the reaction temperature to 90 to 150°C; after the epoxy resin C has completely melted, slowly add 20 to 25 parts of acrylic acid and add 0.01 to 0.1 parts of catalyst 2; react for 0.5 to 5.0 hours, and after cooling, obtain acrylic liquid crystal photosensitive resin D; (5) Mix 20 parts of acrylic liquid crystal photosensitive resin D and 0.1 to 1.0 parts of polymerization inhibitor by molar, then add organic solvent and 0.01 to 0.1 parts of catalyst 3; set the reaction temperature to 30 to 80°C, and after the acrylic liquid crystal photosensitive resin D is completely dissolved, add 5 to 10 parts of 1,1',3,3'-dimethyldisiloxane dropwise and react for 2 to 5 hours to obtain a silicon chain acrylic liquid crystal photosensitive resin.

2. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The compound containing a mesocrystalline unit and having a -OH terminal as described in step (1) is one or a combination of 4-hydroxyphenyl 4-hydroxybenzoate, 4,4′-biphenyl, 3,3',5,5'-tetramethylbiphenyl, 4-((4-hydroxyphenoxy)carbonyl)phenyl 4-hydroxybenzoate, 2,3-bis(4-hydroxyphenyl)acrylonitrile and 4,4'-propylene bisphenol.

3. The method for preparing a liquid crystal photosensitive resin containing a silicon chain according to claim 1, characterized by: The catalyst 1 mentioned in step (1) is one or a combination of tetramethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride.

4. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The concentration of the NaOH solution mentioned in step (2) is 30% to 60%.

5. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The volume ratio of the methanol / acetone solution in step (3) is 1.0:0.1 to 1.0:

10.

6. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The polymerization inhibitor mentioned in step (4) is one or a combination of hydroquinone, benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone.

7. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The catalyst 2 mentioned in step (4) is one or a combination of N,N-diethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine, and N,N'-diethylpiperazine.

8. The method for preparing a silicon-chain acrylic liquid crystal photosensitive resin according to claim 1, characterized in that: The polymerization inhibitor mentioned in step (5) is one or a combination of hydroquinone, benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone; the organic solvent is one or a combination of acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate, and acetonitrile; and the catalyst 3 is one or a combination of platinum chloric acid and Karstedt catalyst.

9. The silicon-chain acrylic liquid crystal photosensitive resin obtained by the preparation method according to any one of claims 1 to 8.

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