A high impact photochromic base resin formulation and method of making same

Abstract

The application discloses a kind of high impact light-induced discoloration substrate resin formula and its preparation method, it is related to optical resin material technical field, by weight fraction, including the following components: methyl methacrylate 59-65 parts, styrene 29-34.5 parts, carboxyl-containing vinyl monomer 5-10 parts, spiro chromic powder 0.03-0.05 parts, allyl beta-cyclodextrin 1-3 parts, anti-fatigue monomer 2-5 parts, self-repairing monomer 0.1-0.3 parts, N-(4-cyano-3-trifluoromethyl phenyl) methacrylamide 1-3 parts, acrylate-terminated hyperbranched organosilicon modified polyurethane 3-5 parts, cellulose nanocrystal 0.5-1 part, initiator 0.8-1.2 parts.The resin has good impact resistance, good aging resistance, significant photochromic effect, and excellent fatigue resistance.

Description

Technical Field

[0001] This invention relates to the field of optical resin materials technology, and in particular to a high-impact photochromic substrate resin formulation and its preparation method. Background Technology

[0002] Photochromic resin lenses are increasingly used in daily life and professional fields. They can automatically adjust the lens's light transmittance according to changes in ambient light intensity, providing wearers with a comfortable visual experience while reducing the harmful effects of ultraviolet rays on the eyes. The photochromic substrate resin, as the core material of photochromic lenses, directly determines the lens's performance and safety. In recent years, with increased participation in outdoor activities and greater emphasis on eye protection, the market demand for photochromic lenses has continued to grow, placing higher demands on their performance, with impact resistance and color-changing speed becoming key indicators.

[0003] Existing photochromic substrate resins suffer from various technical defects due to unreasonable formulation design, including insufficient aging resistance, unsatisfactory photochromic effects, and the need for further improvement in impact resistance and fatigue resistance. To address these issues, Chinese patent application CN110627971A discloses a novel anti-aging and impact-resistant photochromic lens and its preparation method. The substrate, by weight, comprises 25-30 parts styrene, 25-30 parts trimethylolpropane triacrylate, 50-60 parts bisphenol A diacrylate ethoxylate, 10-20 parts spiropyran photochromic powder, 2-3 parts initiator, and 1-2 parts plasticizer. By adding spiropyran photochromic powder and active polymerizable monomers to the substrate, the lens acquires certain anti-aging, impact-resistant, and photochromic properties. However, its impact resistance and fatigue resistance still need further improvement, and the balance between photochromic speed and impact resistance has not yet been effectively resolved.

[0004] It is evident that developing a high-impact photochromic substrate resin formulation and its preparation method that exhibits good impact resistance, excellent aging resistance, significant photochromic effect, and superior fatigue resistance meets market demands and possesses high market value and application prospects. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-impact photochromic substrate resin formulation and its preparation method that has good impact resistance, excellent aging resistance, significant photochromic effect, and excellent fatigue resistance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high-impact photochromic substrate resin formulation, comprising the following components by weight: 59-65 parts of methyl methacrylate, 29-34.5 parts of styrene, 5-10 parts of carboxyl-containing vinyl monomer, 0.03-0.05 parts of spiropyran color-changing powder, 1-3 parts of allyl β-cyclodextrin, 2-5 parts of anti-fatigue monomer, 0.1-0.3 parts of self-healing monomer, 1-3 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 3-5 parts of acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.5-1 parts of cellulose nanocrystals, and 0.8-1.2 parts of initiator.

[0007] Preferably, the carboxyl-containing vinyl monomer is at least one of acrylic acid and methacrylic acid.

[0008] Preferably, the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)].

[0009] Preferably, the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.

[0010] Preferably, the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 400-600.

[0011] Preferably, the self-healing monomer is bis(2-methylpropene)ethoxydisulfide.

[0012] Preferably, there are no special requirements for the source of the acrylate-terminated hyperbranched silicone-modified polyurethane. In one embodiment of the present invention, the acrylate-terminated hyperbranched silicone-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B.

[0013] Preferably, the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm, and are provided by Beijing Naxun Technology Co., Ltd.

[0014] Preferably, the initiator is azobisisoheptanenitrile.

[0015] Another objective of this invention is to provide a method for preparing the high-impact photochromic substrate resin, comprising the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 20-30 minutes, removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, degassing under vacuum, injecting into a mold, and performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain the high-impact photochromic substrate resin.

[0016] Preferably, the ultrasonic treatment has a power of 200-300W and a temperature of 50-60℃.

[0017] Preferably, the gradient curing process specifically involves: first, maintaining the temperature at 38-42℃ for 5.5-6.5 hours; then, raising the temperature to 108-112℃ at a heating rate of 3-5℃ / min and maintaining the temperature for 2 hours.

[0018] Preferably, the ultraviolet light irradiation time is 8-10 minutes; the ultraviolet light wavelength is 365 nm, and the intensity is 5 mW / cm². 2 .

[0019] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0020] (1) The high impact-resistant photochromic substrate resin formulation and its preparation method disclosed in this invention have low equipment dependence, simple process flow, easy control of production conditions, strong operability, low energy consumption, and are suitable for large-scale production, and have high promotion and application value.

[0021] (2) The high-impact photochromic substrate resin formulation disclosed in this invention comprises, by weight, the following components: 59-65 parts methyl methacrylate, 29-34.5 parts styrene, 5-10 parts carboxyl-containing vinyl monomer, 0.03-0.05 parts spiropyran color-changing powder, 1-3 parts allyl β-cyclodextrin, 2-5 parts anti-fatigue monomer, 0.1-0.3 parts self-healing monomer, 1-3 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 3-5 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.5-1 parts cellulose nanocrystals, and 0.8-1.2 parts initiator. Through the synergistic effect of the components, the resulting high-impact photochromic substrate resin exhibits good impact resistance, excellent aging resistance, significant photochromic effect, and superior fatigue resistance.

[0022] (3) The high-impact photochromic substrate resin formulation disclosed in this invention contains an acrylate-terminated hyperbranched silicone-modified polyurethane with a unique three-dimensional network structure and flexible silicone segments. The hyperbranched structure can form a three-dimensional support skeleton inside the resin to disperse external impact forces; the flexible silicone segments give the material good toughness, and the segments can deform and absorb energy when impacted. At the same time, cellulose nanocrystals have high strength and high modulus characteristics. After being uniformly dispersed in the resin matrix, they act like "nano-reinforcing ribs," tightly bonding with the matrix, enhancing interfacial forces, and effectively preventing crack propagation. The synergistic effect of the two with the matrix formed by the polymerization of monomers such as methyl methacrylate and styrene significantly improves the impact resistance of the substrate resin. Spiropyran color-changing powder is the core component of photochromism, and the introduction of allyl β-cyclodextrin provides it with a stable inclusion environment. The cavity of allyl β-cyclodextrin forms a host-guest inclusion complex with spiropyran molecules, which not only stabilizes the ring-opening and ring-closing intermediates of spiropyran, lowers the activation energy of the ring-opening reaction, and accelerates the color change response, but also effectively inhibits the aggregation and degradation of spiropyran under long-term light exposure. The hydrogen bonds formed between the carboxyl-containing vinyl monomer and the spiropyran ring-opening further stabilize its structure and reduce the probability of photodegradation. Through these multiple effects, the substrate resin achieves excellent photochromic properties with a short color change response time and rapid fading recovery, and remains stable during long-term use.

[0023] (4) The high-impact photochromic substrate resin formulation disclosed in this invention uses flexible segments of fatigue-resistant monomers to form sliding molecular chains within the material. When the material is subjected to cyclic stress, the relative sliding of the chains can effectively dissipate fatigue energy and inhibit the initiation and propagation of microcracks. The special functional groups such as the cyano and trifluoromethyl groups in N-(4-cyano-3-trifluoromethylphenyl)methacrylamide can enhance the intermolecular interaction forces and further improve the material's resistance to fatigue damage. The synergistic effect of both allows the substrate resin to maintain good performance even after undergoing frequent photochromic cycles and external stress during long-term use. The addition of self-healing monomers endows the substrate resin with self-healing properties. When the dynamic covalent bonds in the self-healing monomers break, they can undergo a reversible break-recombination reaction under heat or light conditions, automatically repairing the break points. This self-healing process does not require external intervention and can proceed slowly under ambient light conditions during daily use, effectively extending the service life of the substrate resin.

[0024] (5) The high-impact photochromic substrate resin formulation disclosed in this invention does not involve a simple superposition of components, but rather a synergistic effect through chemical bonding, intermolecular forces, and other means. For example, the strong interfacial interaction between cellulose nanocrystals and the matrix helps the hyperbranched organosilicon-modified polyurethane to better exert its impact resistance; the inclusion effect of allyl β-cyclodextrin on spiropyran provides a stable microenvironment for the self-healing components, promoting the self-healing reaction. This synergistic effect enables the substrate resin to achieve comprehensive improvements in impact resistance, photochromic properties, fatigue resistance, and self-healing properties, while maintaining good optical transparency and chemical stability, thus possessing extremely high practical value and market competitiveness. Detailed Implementation

[0025] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0026] Example 1

[0027] A high-impact photochromic substrate resin formulation, by weight, comprises the following components: 59 parts methyl methacrylate, 29 parts styrene, 5 parts carboxyl-containing vinyl monomer, 0.03 parts spiropyran color-changing powder, 1 part allyl β-cyclodextrin, 2 parts anti-fatigue monomer, 0.1 parts self-healing monomer, 1 part N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 3 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.5 parts cellulose nanocrystals, and 0.8 parts initiator.

[0028] The carboxyl-containing vinyl monomer is acrylic acid; the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)]; the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 400; the self-healing monomer is bis(2-methylpropene)ethoxydisulfide; the acrylate-terminated hyperbranched organosilicon-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B; the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm and are provided by Beijing Naxun Technology Co., Ltd.; the initiator is azobisisoheptanenitrile.

[0029] A method for preparing the high-impact photochromic substrate resin includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 20 min, and removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, vacuum degassing, and injecting into a mold; performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain the high-impact photochromic substrate resin; the ultrasonic treatment power is 200W, and the temperature is 50℃; the gradient curing treatment specifically includes: first, holding at 38℃ for 5.5 h; then raising the temperature to 108℃ at a heating rate of 3℃ / min and holding for 2 h; the ultraviolet light irradiation time is 8 min; the ultraviolet light wavelength is 365nm, and the intensity is 5mW / cm². 2 .

[0030] Example 2

[0031] A high-impact photochromic substrate resin formulation, by weight, comprises the following components: 61 parts methyl methacrylate, 31 parts styrene, 6 parts carboxyl-containing vinyl monomer, 0.035 parts spiropyran color-changing powder, 1.5 parts allyl β-cyclodextrin, 3 parts anti-fatigue monomer, 0.15 parts self-healing monomer, 1.5 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 3.5 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.6 parts cellulose nanocrystals, and 0.9 parts initiator.

[0032] The carboxyl-containing vinyl monomer is methacrylic acid; the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)]; the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 450; the self-healing monomer is bis(2-methylpropene)ethoxydisulfide; the acrylate-terminated hyperbranched organosilicon-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B; the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm and are provided by Beijing Naxun Technology Co., Ltd.; the initiator is azobisisoheptanenitrile.

[0033] A method for preparing the high-impact photochromic substrate resin includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 23 min, and removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, degassing under vacuum, and injecting into a mold; performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain the high-impact photochromic substrate resin; the ultrasonic treatment power is 230W, and the temperature is 53℃; the gradient curing treatment specifically includes: first, holding at 39℃ for 5.8 h; then raising the temperature to 109℃ at a heating rate of 3.5℃ / min and holding for 2 h; the ultraviolet light irradiation time is 8.5 min; the ultraviolet light wavelength is 365nm, and the intensity is 5mW / cm². 2 .

[0034] Example 3

[0035] A high-impact photochromic substrate resin formulation, by weight, comprises the following components: 63 parts methyl methacrylate, 32.5 parts styrene, 7 parts carboxyl-containing vinyl monomer, 0.04 parts spiropyran color-changing powder, 2 parts allyl β-cyclodextrin, 3.5 parts anti-fatigue monomer, 0.2 parts self-healing monomer, 2 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 4 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.8 parts cellulose nanocrystals, and 1 part initiator.

[0036] The carboxyl-containing vinyl monomer is acrylic acid; the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)]; the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 500; the self-healing monomer is bis(2-methylpropene)ethoxydisulfide; the acrylate-terminated hyperbranched organosilicon-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B; the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm and are provided by Beijing Naxun Technology Co., Ltd.; the initiator is azobisisoheptanenitrile.

[0037] A method for preparing a high-impact photochromic substrate resin includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 25 min, and removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, vacuum degassing, and injecting into a mold; performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain a high-impact photochromic substrate resin; the ultrasonic treatment power is 250W, and the temperature is 55℃; the gradient curing treatment specifically includes: first, holding at 40℃ for 6 h; then raising the temperature to 110℃ at a heating rate of 4℃ / min and holding for 2 h; the ultraviolet light irradiation time is 9 min; the ultraviolet light wavelength is 365nm, and the intensity is 5mW / cm². 2 .

[0038] Example 4

[0039] A high-impact photochromic substrate resin formulation, by weight, comprises the following components: 64 parts methyl methacrylate, 34 parts styrene, 9 parts carboxyl-containing vinyl monomer, 0.045 parts spiropyran color-changing powder, 2.5 parts allyl β-cyclodextrin, 4.5 parts anti-fatigue monomer, 0.25 parts self-healing monomer, 2.5 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 4.5 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.9 parts cellulose nanocrystals, and 1.1 parts initiator.

[0040] The carboxyl-containing vinyl monomer is a mixture of acrylic acid and methacrylic acid in a mass ratio of 1:3; the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)]; the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 550; the self-healing monomer is bis(2-methylpropene)ethoxydisulfide; the acrylate-terminated hyperbranched organosilicon-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B; the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm and are provided by Beijing Naxun Technology Co., Ltd.; the initiator is azobisisoheptanenitrile.

[0041] A method for preparing the high-impact photochromic substrate resin includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 28 min, and removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, degassing under vacuum, and injecting into a mold; performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain the high-impact photochromic substrate resin; the ultrasonic treatment power is 290W, and the temperature is 58℃; the gradient curing treatment specifically includes: first, holding at 41℃ for 6.3 h; then raising the temperature to 111℃ at a heating rate of 4.5℃ / min and holding at that temperature for 2 h; the ultraviolet light irradiation time is 9.5 min; the ultraviolet light wavelength is 365nm, and the intensity is 5mW / cm². 2 .

[0042] Example 5

[0043] A high-impact photochromic substrate resin formulation, by weight, comprises the following components: 65 parts methyl methacrylate, 34.5 parts styrene, 10 parts carboxyl-containing vinyl monomer, 0.05 parts spiropyran color-changing powder, 3 parts allyl β-cyclodextrin, 5 parts anti-fatigue monomer, 0.3 parts self-healing monomer, 3 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 5 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 1 part cellulose nanocrystals, and 1.2 parts initiator.

[0044] The carboxyl-containing vinyl monomer is methacrylic acid; the spiropyran color-changing powder is spiro[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)]; the allyl β-cyclodextrin is provided by Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.; the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 600; the self-healing monomer is bis(2-methylpropene)ethoxydisulfide; the acrylate-terminated hyperbranched organosilicon-modified polyurethane is prepared according to the method of Example 1 of Chinese Invention Patent No. CN111393608B; the cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm and are provided by Beijing Naxun Technology Co., Ltd.; the initiator is azobisisoheptanenitrile.

[0045] A method for preparing the high-impact photochromic substrate resin includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonically treating for 30 min, and removing the ethanol by rotary evaporation to obtain an inclusion complex; mixing the inclusion complex and other components evenly, vacuum degassing, and injecting into a mold; performing gradient curing treatment using a gradient curing process; after the gradient curing treatment is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain the high-impact photochromic substrate resin; the ultrasonic treatment power is 300W, and the temperature is 60℃; the gradient curing treatment specifically includes: first, holding at 42℃ for 6.5 h; then raising the temperature to 112℃ at a heating rate of 5℃ / min and holding for 2 h; the ultraviolet light irradiation time is 10 min; the ultraviolet light wavelength is 365nm, and the intensity is 5mW / cm². 2 .

[0046] Comparative Example 1

[0047] A high-impact photochromic substrate resin formulation and its preparation method are basically the same as those in Example 1, except that allyl β-cyclodextrin and anti-fatigue monomers are not added.

[0048] Comparative Example 2

[0049] A high-impact photochromic substrate resin formulation and its preparation method are basically the same as those in Example 1, except that acrylate-terminated hyperbranched organosilicon-modified polyurethane and cellulose nanocrystals are not added.

[0050] To further illustrate the beneficial technical effects of the high-impact photochromic substrate resin formulations and their preparation methods involved in the various embodiments of the present invention, relevant performance tests were conducted on the high-impact photochromic substrate resins involved in Examples 1-5 and Comparative Examples 1-2; the test methods are as follows:

[0051] (1) Photochromic properties: The test was conducted using a UV-Vis spectrophotometer. The test principle involved placing a 365nm UV light source in the sample chamber of the UV-Vis spectrophotometer, with the light source 10cm away from the substrate resin and an irradiance of 22.2w / m². 2 The UV-Vis spectrophotometer measures the transmittance at 450 nm. At the start of the test, the UV lamp in the sample chamber is turned on after one second, and the color change rate of the sample under this UV irradiation is recorded; after 60 seconds, the UV lamp in the sample chamber is turned off, and the transmittance of the sample at 450 nm is measured again, and the fading rate of the sample is recorded.

[0052] (2) Impact resistance: The test was conducted according to QB / T2506-2017. The testing equipment was an impact resistance tester, and the test sample was a photochromic substrate resin lens prepared according to the method of this invention. During the test, a steel ball with a diameter of 16 mm and a mass of 16 g was dropped vertically along a tubular column with an inner diameter of 25 mm, an outer diameter of 32 mm, and a length of 1.27 m. The landing point was the center point of the lens. The lens breakage was recorded. Each sample was tested 100 times, and the number of times it did not break was counted and the breakage rate was calculated.

[0053] (3) Aging resistance: The yellow index was tested after being exposed to 340nm ultraviolet light at 70℃ for 20 hours in a Q-LAB aging chamber.

[0054] As can be seen from Table 1, the high-impact photochromic substrate resin formulation and preparation method disclosed in this invention produce high-impact photochromic substrate resin with better photochromic properties, superior impact resistance and aging resistance. The combined use of allyl β-cyclodextrin, anti-fatigue monomer, acrylate-terminated hyperbranched organosilicon-modified polyurethane and cellulose nanocrystals is beneficial to improving the above properties.

[0055] Table 1. Test results of high-impact photochromic substrate resin properties

[0056] project Color change time (s) Fading time (s) Breakage rate (%) Aging resistance Example 1 8 12 1 ＜3% Example 2 6 11 1 ＜2% Example 3 5 11 0 ＜1% Example 4 3 9 0 ＜1% Example 5 3 8 0 ＜1% Comparative Example 1 15 20 6 ＞12% Comparative Example 2 18 25 12 ＞9%

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-impact photochromic substrate resin, characterized in that, The product comprises, by weight, the following components: 59-65 parts methyl methacrylate, 29-34.5 parts styrene, 5-10 parts carboxyl-containing vinyl monomer, 0.03-0.05 parts spiropyran color-changing powder, 1-3 parts allyl β-cyclodextrin, 2-5 parts anti-fatigue monomer, 0.1-0.3 parts self-healing monomer, 1-3 parts N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 3-5 parts acrylate-terminated hyperbranched organosilicon-modified polyurethane, 0.5-1 parts cellulose nanocrystals, and 0.8-1.2 parts initiator; wherein the anti-fatigue monomer is polyethylene glycol dimethacrylate with an average molecular weight of 400-600; and the self-healing monomer is bis(2-methylpropene)ethoxydisulfide.

2. The high-impact photochromic substrate resin according to claim 1, characterized in that, The carboxyl-containing vinyl monomer is at least one of acrylic acid and methacrylic acid.

3. The high-impact photochromic substrate resin according to claim 1, characterized in that, The spiropyran color-changing powder is spirop[1,3,3-trimethylindole-(6'-nitrobenzodihydropyran)].

4. The high-impact photochromic substrate resin according to claim 1, characterized in that, The cellulose nanocrystals have a length of 100-500 nm and a diameter of 20-100 nm.

5. The high-impact photochromic substrate resin according to claim 1, characterized in that, The initiator is azobisisoheptanenitrile.

6. A method for preparing a high-impact photochromic substrate resin according to any one of claims 1-5, characterized in that, The process includes the following steps: adding spiropyran color-changing powder and allyl β-cyclodextrin to ethanol, ultrasonicating for 20-30 minutes, removing the ethanol by rotary evaporation to obtain the inclusion complex; mixing the inclusion complex and other components evenly, degassing under vacuum, and injecting it into a mold; performing gradient curing using a gradient curing process; after the gradient curing process is completed, allowing the mold to cool naturally to room temperature, demolding and removing the substrate resin; then placing the substrate resin in an ultraviolet light irradiation device for ultraviolet light irradiation to obtain a high-impact photochromic substrate resin.

7. The method for preparing the high-impact photochromic substrate resin according to claim 6, characterized in that, The ultrasonic treatment has a power of 200-300W and a temperature of 50-60℃.

8. The method for preparing the high-impact photochromic substrate resin according to claim 6, characterized in that, The gradient curing process specifically involves: first, maintaining a temperature of 38-42℃ for 5.5-6.5 hours; then, increasing the temperature to 108-112℃ at a rate of 3-5℃ / min and maintaining this temperature for 2 hours; the ultraviolet light irradiation time is 8-10 minutes; the ultraviolet light wavelength is 365nm and the intensity is 5mW / cm². 2 .