A photocurable resin, its preparation method and application on medical electronic products

Abstract

The present invention belongs to the technical field of modified application of photocurable resin, and particularly relates to a photocurable resin and a preparation method thereof and application in medical electronic products. The photocurable resin comprises, by weight, 30-50 parts of polyether polyurethane acrylate, 25-50 parts of acryloyl morpholine, 10-30 parts of trimethylolpropane triacrylate, 5-20 parts of ethoxylated trimethylolpropane triacrylate, 2.5-3 parts of free radical photoinitiator, 0.01-0.1 parts of fluorescent brightener, and 0.5-5 parts of nylon powder. Due to the presence of the brightener, the resin system remains clear and transparent during the entire light curing process, which is conducive to the resin system absorbing light more fully and polymerizing more fully, and the number of residual organic small molecules is extremely small, which greatly reduces the toxicity, and after being used in conjunction with nylon powder, it can be more conducive to the dimensional stability of the cured product.

Description

Technical Field

[0001] The invention belongs to the technical field of modified application of light-curing resins, and in particular relates to a light-curing resin and a preparation method thereof, and application of the light-curing resin to medical electronic products. Background Art

[0002] Photocuring of resin is a relatively new process for preparing artificial polymers. Free radical polymerization is the most commonly used curing method for photocurable resins. Its principle is to decompose the photoinitiator dispersed in the resin under light conditions to produce free radicals, which then initiate the polymerization of monomers to form polymers. Photocurable resins have the advantages of low energy consumption and low cost, and are currently widely used in coatings, inks, adhesives, electronic products and other fields.

[0003] With the rapid development of modern industry, the performance requirements for photocurable products are getting higher and higher. For example, the dimensional stability of the cured product. During the curing process, the resin will inevitably shrink to a certain extent. How to minimize the dimensional shrinkage during the curing process has always been a focus of attention. At the same time, since the photocuring system needs to rely on external light conditions to achieve its internal curing reaction, the curing often cannot reach a fully sufficient degree, leaving a large amount of organic small molecules such as polymerized monomers in the product. These organic small molecules will gradually migrate out of the product and release over time, which will be toxic to the human body, which further limits the application of photocurable resin products. Summary of the invention

[0004] To solve the above technical problems, the present invention provides a photocurable resin, which includes, by weight, 30 to 50 parts of polyether polyurethane acrylate, 25 to 50 parts of acryloyl morpholine, 10 to 30 parts of trimethylolpropane triacrylate, 5 to 20 parts of ethoxylated trimethylolpropane triacrylate, 2.5 to 3 parts of free radical photoinitiator, 0.01 to 0.1 parts of fluorescent whitening agent, and 0.5 to 5 parts of nylon powder.

[0005] Preferably, the composition comprises, by weight, 40 parts of polyether polyurethane acrylate, 30 parts of acryloyl morpholine, 20 parts of trimethylolpropane triacrylate, 15 parts of ethoxylated trimethylolpropane triacrylate, 3.5 parts of free radical photoinitiator, 0.02 parts of fluorescent brightener and 1 part of nylon powder.

[0006] Preferably, the preparation method of polyether polyurethane acrylate is as follows: after mixing polyether diol, diisocyanate and dibutyltin dilaurate, heating and stirring the mixture for a period of time, adding acrylate monomer with hydroxyl group and continuing heating and stirring the mixture for a period of time.

[0007] Preferably, the mass proportion of the free radical photoinitiator does not exceed 5% of the photocurable resin.

[0008] Preferably, the free radical photoinitiator includes one or a mixture of two of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide and hydroxycyclohexyl phenyl ketone.

[0009] Preferably, the fluorescent brightening agent is 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene.

[0010] The present invention also provides a method for preparing the above-mentioned photocurable resin:

[0011] (1) Mix acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, free radical photoinitiator, and fluorescent brightening agent and stir well to obtain mixture 1;

[0012] (2) Heat the polyether polyurethane acrylate to a flowing state, then add it to the mixture 1 obtained in step (1) and stir well to obtain mixture 2;

[0013] (3) Add nylon powder to the mixture 2 obtained in step (2) and stir well.

[0014] The present invention also provides an application of the above-mentioned photocurable resin in medical electronic products.

[0015] Preferably, the photocurable resin is used as a circuit board sealant to coat and seal the circuit board inside the end of the endoscope lens.

[0016] The beneficial effects of the present invention are as follows: The photocurable resin system contains a brightening agent component, which improves the color chroma of the cured product. And the applicant further notes that: during the entire light curing process of the resin system, due to the presence of the brightening agent, after being irradiated with light, the brightening agent generates blue-violet light in the resin system based on its own fluorescence effect, thereby neutralizing the resin component itself and the yellow color that gradually deepens as the curing degree of the resin component increases. During the entire light curing process, the resin system remains relatively clearer and more transparent, which is conducive to the resin system absorbing light more fully, so that the curing polymerization reaction inside the resin is more sufficient and thorough, and the number of organic small molecules remaining in the cured product is extremely small, thus greatly reducing the toxic effect of the cured product on the human body. As a result, the photocurable resin product can be used for medical electronic instrument components that enter the human body, such as endoscopes. The endoscope extends into the human body through its head end for detection. If the end of the endoscope lens releases toxic organic small molecules, the small molecules remaining in the human body will cause damage to various organs in the body. By using the photocurable resin of the present solution as a circuit board sealant to coat and seal the circuit board inside the end of the endoscope lens, there is no need to worry that after the end of the endoscope lens enters the human body, the sealant on its circuit board will release harmful organic small molecules in the human body.

[0017] At the same time, the use of nylon powder as filler in this scheme is not only beneficial to the wear resistance of the resin after curing, but also when the resin light absorption, curing degree and more sufficient degree are faced with the addition of a brightener in this scheme, the nylon powder has a more obvious inhibitory and reducing effect on the photocuring shrinkage of the resin, which is more beneficial to the dimensional stability of the cured product.

[0018] In addition, the present invention also utilizes the multifunctionality of trimethylolpropane triacrylate and ethoxylated trimethylolpropane triacrylate to improve the crosslinking degree of the resin curing and the density of the cured product, thereby better suppressing the toxic effects caused by the migration of small organic molecules in the product; and the flexible chain segments containing ethoxy groups in its molecular structure can improve the impact resistance of the resin. The selection of polyether polyurethane acrylate as the main resin is beneficial to the wear resistance of the product, and the polyether polyurethane acrylate has no irritating groups or the content of irritating groups is very low, that is, the toxicity is low. The active diluent acryloyl morpholine participates in the curing polymerization reaction, which greatly reduces the residual small molecules in the product after curing, thereby reducing toxicity, and can accelerate the curing process. A photoinitiator with high light absorption and low residue is used to reduce the residual amount of the photoinitiator and the amount that can migrate out after the resin is cured, thereby further reducing toxicity. DETAILED DESCRIPTION

[0019] The polyether polyurethane acrylate in the following embodiments and comparative embodiments is as follows: 60 parts by weight of propylene glycol polyether PPG-200 after vacuum dehydration treatment, 170 parts by weight of hexamethylene diisocyanate, and 0.5 parts by weight of dibutyltin dilaurate are added together into a sealed reaction kettle, heated to 70°C under mixed stirring, kept warm and stirred for 2.5 hours, 130 parts by weight of hydroxyethyl methacrylate is added thereto, the temperature is raised to 70°C, the mixture is kept sealed and stirred for 3 hours, and then the mixture is discharged after being cooled in the furnace.

[0020] Example 1

[0021] A photocurable resin, calculated by weight, comprises 40 parts of polyether polyurethane acrylate, 30 parts of N-acryloylmorpholine, 20 parts of trimethylolpropane triacrylate, 15 parts of ethoxylated trimethylolpropane triacrylate, 2 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone, 0.03 parts of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, and 1 part of nylon powder.

[0022] During the preparation of the above-mentioned photocurable resin, the above-mentioned weight parts are respectively as follows:

[0023] (1) N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexylphenyl ketone, and 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene are mixed and stirred thoroughly to prepare a mixture 1;

[0024] (2) heating polyether polyurethane acrylate at 65° C. to a fully fluid state, adding the polyether polyurethane acrylate to the mixture 1 obtained in step (1) and stirring the mixture to obtain a mixture 2;

[0025] (3) Add nylon powder to the mixture 2 obtained in step (2) and stir thoroughly.

[0026] Example 2

[0027] A photocurable resin, calculated by weight, comprises 45 parts of polyether polyurethane acrylate, 40 parts of N-acryloylmorpholine, 15 parts of trimethylolpropane triacrylate, 20 parts of ethoxylated trimethylolpropane triacrylate, 1 part of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexyl phenyl ketone, 0.04 parts of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, and 2 parts of nylon powder.

[0028] During the preparation of the above-mentioned photocurable resin, the above-mentioned weight parts are respectively as follows:

[0029] (1) N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexylphenyl ketone, and 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene are mixed and stirred thoroughly to prepare a mixture 1;

[0030] (2) heating polyether polyurethane acrylate at 70° C. to a fully fluid state, adding the polyether polyurethane acrylate to the mixture 1 obtained in step (1) and stirring the mixture to obtain a mixture 2;

[0031] (3) Add nylon powder to the mixture 2 obtained in step (2) and stir thoroughly.

[0032] Example 3

[0033] A photocurable resin, calculated by weight, comprises 40 parts of polyether polyurethane acrylate, 50 parts of N-acryloylmorpholine, 10 parts of trimethylolpropane triacrylate, 20 parts of ethoxylated trimethylolpropane triacrylate, 1.5 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone, 0.05 parts of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, and 1.5 parts of nylon powder.

[0034] In the preparation process of the above-mentioned photocurable resin, according to the above weight parts respectively,

[0035] (1) Mix N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexyl phenyl ketone, and 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene and stir well to obtain Mixture 1;

[0036] (2) Heat the polyether polyurethane acrylate to a fully flowing state at 65°C, then add it to Mixture 1 obtained in step (1) and stir well to obtain Mixture 2;

[0037] (3) Add nylon powder to Mixture 2 obtained in step (2) and stir well.

[0038] Comparative Example 1

[0039] No whitening agent was added to the photocurable resin system, and the other components and operations were the same as in Example 1:

[0040] A photocurable resin, calculated by weight parts, includes 40 parts of polyether polyurethane acrylate, 30 parts of N-acryloylmorpholine, 20 parts of trimethylolpropane triacrylate, 15 parts of ethoxylated trimethylolpropane triacrylate, 2 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone, and 1 part of nylon powder,

[0041] In the preparation process of the above-mentioned photocurable resin, according to the above weight parts respectively,

[0042] (1) Mix N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexyl phenyl ketone and stir well to obtain Mixture 1;

[0043] (2) Heat the polyether polyurethane acrylate to a fully flowing state at 65°C, then add it to Mixture 1 obtained in step (1) and stir well to obtain Mixture 2;

[0044] (3) Add nylon powder to Mixture 2 obtained in step (2) and stir well.

[0045] For the photocurable resin systems prepared in the above examples and comparative examples, after uniformly coating (thickness 0.5 mm) on the smooth horizontal surface of a stainless steel substrate at room temperature (25°C, the same below), through a wavelength of 365 nm and a power of 10 mW / cm 2The coating obtained by light curing is irradiated vertically downward with ultraviolet light for 60 minutes (fully cured). The coating obtained by light curing is carefully peeled off from the stainless steel substrate and cut into several square flakes with a size of 1 cm × 1 cm. After the flaky coating is immersed in physiological saline at 37 °C for 5 hours (single flaky coating is immersed in 5 mL of physiological saline), after the flaky coating is taken out of the physiological saline, the cytotoxicity of the physiological saline is detected with reference to the standard of GB / T 16886.5-2017. The detection operation is as follows:

[0046] L929 cells are cultured in MEM culture medium containing 10% (mass concentration) fetal bovine serum and antibiotics (penicillin 100 IU / mL, streptomycin 100 μg / mL), and are cultured in an incubator with an air atmosphere of 5% (volume fraction) at 37 °C and CO 2 After culturing for a period of time, it is used as a culture medium. The L929 cells in this culture medium are digested with 0.25% (mass concentration) trypsin (containing EDTA) (to further disperse the L929 cells) to obtain a single cell suspension. After the single cell suspension is centrifuged at 1000 rpm for 5 min, the cells are redispersed at a cell density of 1×10 5 cells / mL in the same MEM culture medium as above to obtain a cell dispersion liquid.

[0047] The cell dispersion liquid obtained above is inoculated into a 96-well culture plate, 100 μL per well. The 96-well culture plate is placed in an incubator with an air atmosphere of 5% (volume fraction) at 37 °C and CO 2 After culturing for 24 h until the cells grow into a monolayer, the culture solution in each well of the 96-well culture plate is aspirated. Then, the physiological saline impregnated with the flaky coating of the photocurable resin in Example 1, the physiological saline impregnated with the flaky coating of the photocurable resin in Example 2, the physiological saline impregnated with the flaky coating of the photocurable resin in Example 3, the physiological saline impregnated with the flaky coating of the photocurable resin in Comparative Example 1, and blank physiological saline (the above physiological saline without any impregnation) are respectively added to different wells of the 96-well culture plate, and the addition amount per well is 100 μL. Six wells are made for each kind of physiological saline. Then, the 96-well culture plate is placed in an incubator with an air atmosphere of 5% (volume fraction) at 37 °C and CO 2 After culturing for 24 h, the 96-well culture plate is taken out and first observed for cell morphology. The results are shown in Table 1;

[0048] After observation and recording, the physiological saline in each well of the 96-well culture plate is aspirated. Then, 50 μL of MTT (1 mg / mL) is added to each well of the 96-well culture plate and cultured for 2 h. Then, the supernatant is aspirated. Then, 100 μL of isopropanol is added to each well to dissolve the crystals. The absorbance is measured on an enzyme-linked immunosorbent assay (ELISA) reader with 570 nm as the main absorption wavelength and 650 nm as the reference wavelength. The results are shown in Table 2.

[0049] Table 1: Cell morphology results

[0050]

[0051]

[0052] Table 2: Cell activity results (assuming that the cell viability corresponding to the absorbance measured after intervention with blank saline is 100%)

[0053]

[0054] (According to the requirements, the cell viability in the saline solution immersed in the sample is ≥ 70% of the cell viability in the blank saline solution, and the sample material can be considered non-cytotoxic)

[0055] In summary, it can be seen that after the common photocurable resin component in Comparative Example 1 is fully cured by light, it is not suitable for medical electronic devices that enter the human body due to its high cytotoxicity;

[0056] In contrast, in the embodiments of the present scheme, since fluorescent brighteners are involved in the entire light-curing process, the brighteners exposed to light produce blue-violet light in the resin system, thereby neutralizing the resin component itself and the yellow color of the resin component that gradually deepens with the deepening of the curing degree. During the entire light-curing process, the resin system remains relatively clearer and more transparent, allowing the resin system to more fully absorb light, thereby making the curing polymerization reaction inside the resin more complete and thorough, and the number of organic small molecules remaining after the curing reaction is extremely small. Therefore, when it is used as a sealant for the circuit board in the end of the endoscope lens, the toxic effects on cells in the human body are effectively avoided.

[0057] Blank control example

[0058] No brightener or nylon powder was added to the photocurable resin system, and the remaining components and operations were the same as those in Example 1:

[0059] A photocurable resin, calculated by weight, comprises 40 parts of polyether polyurethane acrylate, 30 parts of N-acryloylmorpholine, 20 parts of trimethylolpropane triacrylate, 15 parts of ethoxylated trimethylolpropane triacrylate, 2 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, and 1.5 parts of 1-hydroxycyclohexyl phenyl ketone.

[0060] During the preparation of the above-mentioned photocurable resin, the above-mentioned weight parts are respectively as follows:

[0061] (1) N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexylphenyl ketone are mixed and stirred thoroughly to obtain a mixture 1;

[0062] (2) After heating polyether polyurethane acrylate at 65° C. to a fully fluid state, add it to the mixture 1 obtained in step (1) and stir thoroughly.

[0063] Comparative Example 1

[0064] No brightener was added to the photocurable resin system, and the remaining components and operations were the same as those in Example 1:

[0065] That is the solution of Comparative Example 1.

[0066] Comparative Example 2

[0067] No nylon powder was added to the photocurable resin system, and the remaining components and operations were the same as those in Example 1:

[0068] A photocurable resin, calculated by weight, includes 40 parts of polyether polyurethane acrylate, 30 parts of N-acryloylmorpholine, 20 parts of trimethylolpropane triacrylate, 15 parts of ethoxylated trimethylolpropane triacrylate, 2 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone, and 0.03 parts of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene.

[0069] During the preparation of the above-mentioned photocurable resin, the above-mentioned weight parts are respectively as follows:

[0070] (1) N-acryloylmorpholine, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexylphenyl ketone, and 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene are mixed and stirred thoroughly to prepare a mixture 1;

[0071] (2) After heating polyether polyurethane acrylate at 65° C. to a sufficiently fluid state, add it to the mixture 1 obtained in step (1) and stir thoroughly to obtain a mixture 2.

[0072] According to GB / T 24148.9-2014, the total volume shrinkage of the photocurable resin system prepared in the above embodiments and control examples was measured (the light curing conditions were: the wavelength was 365nm and the power was 10mW / cm at room temperature). 2 The test results are shown in the following table:

[0073]

[0074] In the above table, the curing by light was carried out without the promotion of the optical brightener in both Comparative Example 1 and the blank control example. After adding nylon powder for modification in Comparative Example 1 compared with the blank control example, the curing shrinkage rate was improved to a certain extent.

[0075] In Comparative Example 2, the curing was carried out under the promotion of the optical brightener for light absorption. Therefore, compared with the blank control example, the curing degree of Comparative Example 2 was more sufficient, and the volume shrinkage after curing was naturally more obvious. From this speculation, since the curing in both Comparative Example 1 and Example 1 occurred under the modification with nylon powder, and Example 1 added more optical brightener than Comparative Example 1, Example 1 should absorb light more sufficiently and the shrinkage after curing should be more obvious; however, the final curing volume shrinkage rate of Example 1 was lower than that of Comparative Example 1, and this effect was not easily expected. It can be seen that the inhibition of the shrinkage rate in Example 1 was significantly higher than that in Comparative Example 1.

Claims

1. A photocurable resin, characterized in that: The photocurable resin comprises, by weight, 30 to 50 parts of polyether polyurethane acrylate, 25 to 50 parts of acryloyl morpholine, 10 to 30 parts of trimethylolpropane triacrylate, 5 to 20 parts of ethoxylated trimethylolpropane triacrylate, 2.5 to 3 parts of free radical photoinitiator, 0.01 to 0.1 parts of fluorescent brightener, and 0.5 to 5 parts of nylon powder, wherein the fluorescent brightener is 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, and the photocurable resin is prepared by the following method: (1) mixing the acryloyl morpholine, the trimethylolpropane triacrylate, the ethoxylated trimethylolpropane triacrylate, the free radical photoinitiator, and the fluorescent brightener, and stirring them thoroughly to obtain a mixture 1; (2) heating the polyether polyurethane acrylate to a fluid state, adding the polyether polyurethane acrylate to the mixture 1 obtained in step (1) and stirring the mixture thoroughly to obtain a mixture 2; (3) Add the nylon powder to the mixture 2 obtained in step (2) and stir thoroughly.

2. The photocurable resin according to claim 1, wherein: The preparation method of the polyether polyurethane acrylate is as follows: after mixing polyether diol, diisocyanate and dibutyltin dilaurate, heating and stirring the mixture for a period of time, adding acrylate monomers with hydroxyl groups thereto and continuing heating and stirring the mixture for a period of time.

3. The photocurable resin according to claim 1, wherein: The mass proportion of the free radical photoinitiator does not exceed 5% of the photocurable resin.

4. The photocurable resin according to claim 1, wherein: The free radical photoinitiator is one of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide and 1-hydroxycyclohexyl phenone or a mixture of the two.

5. Use of the photocurable resin according to any one of claims 1 to 4 in medical electronic products.

6. The use according to claim 5, characterized in that: The photocurable resin is used to coat and seal a circuit board in the end of an endoscope head.

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