Preparation process of ultraviolet-proof contact lenses

Abstract

The invention provides a preparation technology of ultraviolet-proof contact lenses, and relates to the technical field of contact lenses, and the preparation technology comprises the following steps: step S0, carrying out a pre-detection process; the preparation method comprises the following steps: S1, weighing raw materials according to the raw material ratio of the ultraviolet-proof contact S2, stirring the base material raw material of the ultraviolet-proof contact lens and the ultraviolet absorbent weighed in the step S1 to prepare a mixture 1; s3, adding the initiator and the cross-linking agent weighed in the step S1 into the mixture 1, and stirring to obtain a mixture 2; s4, adding the mixture 2 into a curing mold, and carrying out curing molding; the pre-detection process is carried out before the step S1 is executed, the quality, purity and the like of the raw materials can be checked in advance (each batch of raw materials are executed once), the product quality is controlled from the source, unqualified products caused by raw material problems are reduced, and the production yield is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of contact lenses, in particular to a preparation process of an ultraviolet-proof contact lens. BACKGROUND

[0002] In the modern eye health protection system, ultraviolet-proof contact lenses have become an important product category in the field of eye protection due to their dual advantages of "no wearing burden" and "all-scene protection". The core design logic is to introduce ultraviolet absorbers into the lens substrate to build a physical barrier layer for 280-400nm ultraviolet rays (including UVC, UVB which significantly damages the cornea and lens, and UVA which accelerates the aging of the fundus), which not only avoids the obstruction of the field of view of traditional frame sunglasses and the inconvenience of wearing in sports scenes, but also fills the functional gap of ordinary contact lenses "only correcting vision, no ultraviolet protection", and is widely used in outdoor work, sports fitness, daily commuting and other scenes.

[0003] In the prior art, the preparation of ultraviolet-proof contact lenses relies on the experience setting of the same raw materials. However, due to the differences between different batches of raw materials, it is easy to cause the product quality to not meet the requirements when the process is controlled according to fixed experience parameters. SUMMARY

[0004] The present application provides a preparation process of an ultraviolet-proof contact lens to solve the technical problems raised in the background art.

[0005] To solve the above technical problems, the present application discloses a preparation process of an ultraviolet-proof contact lens, comprising: Step S0: performing a pre-detection process; Step S1: weighing raw materials according to the raw material ratio of the ultraviolet-proof contact lens; Step S2: stirring the base material raw materials and ultraviolet absorbers weighed in step S1 to obtain a mixture 1; Step S3: adding the initiator and crosslinking agent weighed in step S1 to the mixture 1 and stirring to obtain a mixture 2; Step S4: adding the mixture 2 to a curing mold for curing and forming.

[0006] Preferably, the pre-detection process comprises: Step S01: weighing and stirring the base material raw materials and ultraviolet absorbers of the standby batch to obtain a pre-stirring mixture 1; Sampling several samples from different positions of the pre-stirring mixture 1 and performing absorbance detection on the samples to obtain the dispersion coefficient of variation of the mixture 1; Step S02: Take the pre-stirred mixture 1, add initiator, crosslinking agent for pre-stirring, get pre-stirred mixture 2, take pre-stirred mixture 2, dissolve in solvent, carry out absorbance detection under the characteristic wavelength of initiator, get the actual absorbance of mixture 2, determine the initiator activity retention coefficient based on the actual absorbance of mixture 2; Step S03: Detect the key parameters of the crosslinking agent to be used, and determine the crosslinking agent activity coefficient; Step S04: When any one of the mixture 1 dispersion variation coefficient, initiator activity retention coefficient, crosslinking agent activity coefficient is not in the corresponding preset target coefficient range, alarm.

[0007] Preferably, the step S02 further comprises: detecting the temperature of mixture 2, determining the mixing reaction heat based on the temperature of mixture 2, and determining the initiator and crosslinking agent synergistic reaction coefficient based on the mixing reaction heat; In step S04, when the initiator and crosslinking agent synergistic reaction coefficient is not in the corresponding preset target coefficient range, also pre-alarm.

[0008] Preferably, it further comprises: Step S05: The process of step S4 is divided into a temperature rising section, an isothermal 1 section, an isothermal 2 section, an isothermal 3 section, and the reference final temperature of the temperature rising section, the reference temperature of the isothermal 1 section, the reference temperature of the isothermal 2 section, and the reference temperature of the isothermal 3 section are determined; Step S06: Obtain the temperature-reference decomposition rate fitting curve of the initiator to be used, and correct the temperature-reference decomposition rate fitting curve of the initiator to be used based on the initiator activity retention coefficient; Step S07: Obtain the temperature-reference crosslinking rate fitting curve of the crosslinking agent to be used, and correct the temperature-reference crosslinking rate fitting curve of the crosslinking agent to be used based on the crosslinking agent activity coefficient; Step S08: Determine the target final temperature of the temperature rising section, the target temperature of the isothermal 1 section, the target temperature of the isothermal 2 section, and the target temperature of the isothermal 3 section based on the temperature-reference decomposition rate fitting curve of the initiator to be used and the temperature-reference crosslinking rate fitting curve of the crosslinking agent to be used.

[0009] Preferably, the base material of the anti-ultraviolet contact lens is a monomer mixed solution of HEMA; The weight percentage of the raw material of the anti-ultraviolet contact lens is: The main base material of the contact lens is a monomer mixed solution of HEMA: 90-98.8%; ultraviolet absorber: 0.2-2.5 %; initiator: 0.3-1.0%; crosslinking agent: 0.7-0.9%.

[0010] Preferably, the initiator is azobisdimethyl isobutyronitrile, and the crosslinking agent is ethylene glycol dimethacrylate.

[0011] Preferably, the batch execution step S2 is preceded by a batch execution step S2 stirring parameter determination process, which comprises: Step S201: Obtain the initial stirring parameters of the base material and the ultraviolet absorber of the batch of anti-ultraviolet contact lenses to be executed; Step S202: The base material and the ultraviolet absorber of the batch of anti-ultraviolet contact lenses to be executed are pre-mixed for the second sampling, and the actual stirring speed is controlled to be the initial stirring speed in the second sampling pre-mixing; During the second sampling pre-mixing process, a main flow mixing area is demarcated in the stirring container to detect the viscosity multiple times, a detection time-detection viscosity fitting curve is constructed, and the detection time-detection viscosity fitting curve is divided into multiple second segments, and the difference between the maximum slope and the minimum slope of each second segment is less than the preset slope difference; During the second sampling pre-mixing process, the vibration speed monitored by the vibration sensor on the stirring shaft is obtained multiple times, the actual first ratio of the vibration speed of each second segment to the average slope of the second segment is obtained, and the vibration state coefficient is determined based on the actual first ratio; Step S203: Obtain the detection time-reference viscosity fitting curve and divide it into multiple first segments; Based on the slope of each second segment and the slope of the previous second segment, the switching matching coefficient of each second segment is determined, and the viscosity change state coefficient is determined based on the comparison of the slopes of the second segment and the first segment with the same number; Step S204: Correct the initial stirring speed based on the second segment viscosity change state coefficient, the second segment switching matching coefficient, and the vibration state coefficient to obtain the required stirring speed; Preferably, when the base material and the ultraviolet absorber of the batch of anti-ultraviolet contact lenses to be executed are batch stirred, the stirring is carried out at the required stirring speed and the initial stirring time; The second sampling pre-mixing stirring time is k times the initial stirring time.

[0012] Preferably, the initial stirring parameter acquisition process of the base material and the ultraviolet absorber of the batch of anti-ultraviolet contact lenses to be executed comprises: Step S2011: Detect the refractive index of the base material of the batch of anti-ultraviolet contact lenses to be executed and the refractive index of the ultraviolet absorber to be executed, and determine the refractive index difference coefficient and the refractive index state coefficient; Step S2012: Detect the viscosity of the base material of the batch of anti-ultraviolet contact lenses to be executed and the viscosity of the ultraviolet absorber to be executed, and determine the viscosity difference coefficient and the viscosity state coefficient; Step S2013: first sampling pre-mixing is performed on the base material of the anti-ultraviolet contact lens to be executed and the ultraviolet absorber, the refractive index after mixing is determined, the refractive index-rotation speed coefficient is determined based on the refractive index difference coefficient and the refractive index state coefficient; Step S2014: the initial stirring parameters are determined based on the refractive index-rotation speed coefficient and the viscosity-rotation speed coefficient.

[0013] The technical scheme of the present application is described in further detail below by means of the accompanying drawings and examples.

[0014] Compared with the prior art, the present application has the following beneficial effects: The pre-detection process is performed before the execution of step S1, which can check the quality and purity of the raw materials in advance (once for each batch of raw materials), control the product quality from the source, reduce the unqualified products caused by the raw material problems, and improve the yield of the production.

[0015] The present application adds a proper amount of ultraviolet absorber (2-[3-(2H-benzotriazole-2-methyl)-4-hydroxyphenyl] ethyl methacrylate) in the contact lens material system, so that the prepared contact lens has high ultraviolet resistance.

[0016] The prepared contact lens has high ultraviolet resistance and has no negative effect on the optical performance of the lens.

[0017] The method for improving the ultraviolet resistance of the contact lens has simple preparation process and low production cost.

[0018] Different stirring speeds and times are used in step S2 and step S3. In step S2, the lower speed (200-300 r / min) is stirred for 2-4 hours, which can make the base material and the ultraviolet absorber fully mixed, and at the same time reduce the introduction of air bubbles. In step S3, the speed is appropriately increased (300-400 r / min) and stirred for 1-2 hours, which can make the initiator and the crosslinking agent quickly and uniformly mixed with the mixture 1, provide a uniform material system for subsequent solidification molding, and is beneficial to ensure the consistency of the quality of the final product.

[0019] Azobisdimethyl isobutyronitrile is used as the initiator, and dimethyl glycol methacrylate is used as the crosslinking agent. In the solidification molding process, the initiator decomposes to generate free radicals, initiates the crosslinking reaction, and the crosslinking agent forms a stable crosslinking structure between the molecular chains, so that the prepared contact lens has good mechanical properties, chemical stability and shape stability, and the service life is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application. In the drawings: Figure 1 The flow chart of the present application is shown. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present application will be described herein below with reference to the drawings, in which it is to be understood that the preferred embodiments described herein are illustrative of the present application and are not intended to limit the present application.

[0022] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and does not mean to particularly indicate the order or sequence, nor to limit the present application, which is merely to distinguish the components or operations described by the same technical terms, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features of various embodiments can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the present application.

[0023] The present application provides the following embodiments: Embodiment 1, the present application provides a preparation process of an anti-ultraviolet contact lens, as shown in the following formula (I): Figure 1 The preparation process comprises the following steps: Step S1: according to the raw material ratio of the anti-ultraviolet contact lens, the raw materials are weighed; Step S2: the base material raw materials and the ultraviolet absorber of the anti-ultraviolet contact lens weighed in step S1 are stirred to obtain mixture 1; the stirring time in step S2 is 2-4 hours, and the stirring speed is 200-300 r / min; Step S3: the initiator and the crosslinking agent weighed in step S1 are added into the mixture 1, and stirred to obtain mixture 2; the stirring time in step S3 is 1-2 hours, and the stirring speed is 300-400 r / min; Step S4: the mixture 2 is added into a curing mold for curing and forming; A pre-detection process is performed before step S1.

[0024] Preferably, the base material raw materials of the anti-ultraviolet contact lens are monomer mixed solution of HEMA; The weight percentage of the raw materials of the anti-ultraviolet contact lens is as follows: The main base material of the contact lens is monomer mixed solution of HEMA: 90-98.8%; the ultraviolet absorber: 0.2-2.5 %; the initiator: 0.3-1.0%; the crosslinking agent: 0.7-0.9%.

[0025] Preferably, the initiator is azobisisobutyronitrile, and the crosslinking agent is ethylene glycol dimethacrylate.

[0026] The ultraviolet absorber is 2-[3-(2H-benzotriazol-2-methyl)-4-hydroxyphenyl] ethyl methacrylate (commercial name: UV090).

[0027] The technical scheme has the following beneficial effects: The pre-detection process before step S1 can check the quality and purity of the raw materials in advance (once for each batch of raw materials), control the product quality from the source, reduce the unqualified products caused by the raw material problems, and improve the yield of the production.

[0028] The addition of a proper amount of ultraviolet absorber (2-[3-(2H-benzotriazol-2-methyl)-4-hydroxyphenyl] ethyl methacrylate) in the contact lens material system makes the prepared contact lens have high ultraviolet resistance.

[0029] The prepared contact lens has high ultraviolet resistance and has no negative effect on the optical performance of the lens.

[0030] The method for improving the ultraviolet resistance of the contact lens has simple preparation process and low production cost.

[0031] Steps S2 and S3 adopt different stirring speeds and times. In step S2, the lower speed (200-300 r / min) is stirred for 2-4 hours, so that the base material and the ultraviolet absorber can be fully mixed, and the introduction of air bubbles is reduced. In step S3, the speed is appropriately increased (300-400 r / min) and stirred for 1-2 hours, so that the initiator, the crosslinking agent and the mixture 1 can be quickly and uniformly mixed, providing a uniform material system for subsequent solidification molding, which is beneficial to ensure the consistency of the quality of the final product.

[0032] Azobisisobutyronitrile is used as the initiator, and ethylene glycol dimethacrylate is used as the crosslinking agent. In the solidification molding process, the initiator decomposes to generate free radicals, initiates the crosslinking reaction, and the crosslinking agent forms a stable crosslinking structure between the molecular chains, so that the prepared contact lens has good mechanical properties, chemical stability and shape stability, and the service life is prolonged.

[0033] In example 2, on the basis of example 1, the pre-detection process includes: The pre-detection process includes: Step S01: Take the base material of the batch of anti-UV contact lenses and the batch of UV absorbers to be used, and stir to obtain a pre-stirring mixture 1; Take samples at different positions of the pre-stirring mixture 1, and perform light absorption detection on the samples to obtain the dispersion variation coefficient of the mixture 1; the principle is to use the light absorption characteristics of the UV absorber, and through the difference in light absorption at different positions, to reflect the dispersion uniformity of the UV absorber in the base material.

[0034] Step S02: Take the pre-stirring mixture 1, add an initiator and a crosslinking agent for pre-stirring to obtain a pre-stirring mixture 2, take the pre-stirring mixture 2, add a solvent for dissolution, and perform light absorption detection at the characteristic wavelength of the initiator to obtain the actual light absorption of the mixture 2, and determine the initiator activity retention coefficient based on the actual light absorption of the mixture 2; the characteristic wavelength refers to the wavelength at which the initiator has a specific light absorption capacity. Different initiators have different molecular structures (such as functional groups and conjugated systems), and will have significant absorption of light within a certain wavelength range, and this wavelength that can cause the initiator to have a significant light absorption phenomenon is the characteristic wavelength of the initiator.

[0035] Step S03: Detect the key parameters of the batch of crosslinking agents to be used to determine the crosslinking agent activity coefficient; Step S04: When any one of the dispersion variation coefficient of the mixture 1, the initiator activity retention coefficient, and the crosslinking agent activity coefficient is not within the corresponding preset target coefficient range, an alarm is given.

[0036] Preferably, the step S02 further comprises: detecting the temperature of the mixture 2, determining the mixing reaction heat based on the temperature of the mixture 2, and determining the initiator and crosslinking agent synergistic reaction coefficient based on the mixing reaction heat; Specifically, the individual reaction heats of the initiator and the crosslinking agent in the same system are tested respectively, the sum of the individual reaction heats is calculated, the actual total reaction heat after mixing of the initiator and the crosslinking agent is determined, and the initiator and crosslinking agent synergistic reaction coefficient = actual total reaction heat ÷ sum of individual reaction heats; the above reaction heat is calculated based on the absolute value of the temperature difference before and after the reaction and the basic thermodynamic formula; The same system: consistent material basis (consistent type, ratio and mass, all using the batch to be used), consistent reaction environment; In step S04, when the initiator and crosslinking agent synergistic reaction coefficient is not within the corresponding preset target coefficient range, a warning is also given.

[0037] The initiator activity retention coefficient = actual light absorption of mixture 2 ÷ reference light absorption of initiator; The dispersion variation coefficient of the mixture 1 = standard deviation of light absorption of all samples ÷ average value of light absorption of all samples; it reflects the dispersion uniformity of the UV absorber in the base material. The smaller the variation coefficient, the smaller the difference in light absorption at different positions, and the more uniform the dispersion of the UV absorber.

[0038] Crosslinker Activity Coefficient = (Concentration of Active Functional Groups in the Batch of Crosslinker to be Used ÷ Reference Concentration of Active Functional Groups in Crosslinker) × Purity of the Batch of Crosslinker to be Used × Stability Coefficient of the Batch of Crosslinker to be Used; The purity of the batch of crosslinker to be used refers to the proportion of effective crosslinking components (i.e., active substances capable of participating in crosslinking reactions) in the total substances in the batch of crosslinker to be used, which is usually determined by chemical analysis methods (such as high-performance liquid chromatography, gas chromatography, etc.).

[0039] The stability coefficient of the batch of crosslinker to be used is a parameter that measures the active retention capability of the batch of crosslinker to be used during storage, transportation, or pretreatment. It is usually determined by accelerated aging experiments, long-term stability tests, etc. (for example, after being placed at a specific temperature and humidity for a certain period of time, the retention rate of active functional groups in the crosslinker is detected, and the stability coefficient is calculated accordingly (i.e., stability coefficient = concentration of active functional groups after aging ÷ initial concentration of active functional groups).

[0040] The reference concentration of active functional groups in the crosslinker refers to the concentration benchmark value of active functional groups (such as double bonds capable of participating in crosslinking reactions) in the same type of qualified crosslinker (such as ethylene glycol dimethacrylate) under "standard conditions" (usually the ideal state at the time of factory delivery, without the influence of storage / transportation). It is used for comparison with the actual functional group concentration of the "batch of crosslinker to be used" to determine whether the number of active sites meets the standard.

[0041] Step S04 also calculates a matching coefficient, and an alarm is given when the matching coefficient is not within the corresponding target range; The matching coefficient = weight one × (reference maximum allowed dispersion variation coefficient of mixture 1 ÷ dispersion variation coefficient of mixture 1) + weight two × (initiator activity retention coefficient ÷ reference initiator activity retention coefficient) + weight three × (crosslinker activity coefficient ÷ reference crosslinker activity coefficient) + weight four × (1 - (absolute difference between the initiator and crosslinker synergistic reaction coefficient and the reference initiator and crosslinker synergistic reaction coefficient ÷ reference initiator and crosslinker synergistic reaction coefficient)). The sum of weight one to weight four is 1, and each weight is greater than 0 and less than 1. The more important the corresponding parameter (the degree of quality impact can be determined based on test determination of corresponding parameter change) is, the greater the value is; The reference absorbance of the initiator refers to the absorbance of pure initiator (or initiator standard sample with known accurate content) at its characteristic wavelength under the same detection conditions (such as the same solvent, concentration, optical path, detection instrument, and operation process, etc.) as the actual absorbance of mixture 2. It serves as a benchmark value for comparison with the actual absorbance of mixture 2, thereby calculating the initiator activity retention coefficient, which reflects the retention degree of active ingredients of the initiator after pretreatment such as pre-mixing (i.e., the ability of the effective components of the initiator to maintain absorbance in the system). Reference crosslinking agent activity coefficient is the benchmark value of the same type of qualified crosslinking agent under "standard process conditions" (such as specific storage, detection process) through "active functional group concentration x purity x stability coefficient" calculation. It is used to compare with the actual activity coefficient of "to-be-used batch crosslinking agent" to judge whether the comprehensive reaction activity meets the production requirements.

[0042] Reference initiator activity retention coefficient: is the benchmark value of the same type of qualified initiator under "standard storage, premixing process" (usually close to 1, representing that the activity is basically not lost). It is used to compare with the actual activity retention coefficient of "to-be-used batch initiator" to judge whether the initiator is insufficient due to deterioration or failure.

[0043] Reference synergistic reaction coefficient of initiator and crosslinking agent: is the benchmark value of the synergistic reaction heat (or temperature change) of the same batch of qualified initiator and crosslinking agent under "standard mixing process". It is used to compare with the actual synergistic reaction coefficient of "to-be-used batch initiator + crosslinking agent" to judge whether there is abnormal synergy between the two (such as excessive heat release leading to local overheating, or insufficient heat release leading to incomplete crosslinking).

[0044] The beneficial effects of the above technical solutions are: Through "mixture 1 dispersion variation coefficient" detection, the problem of uneven dispersion of ultraviolet absorber in the substrate (such as local ultraviolet blocking rate exceeding or being insufficient) is quantified. For example, the standard of variation coefficient ≤0.05 can ensure that the ultraviolet absorption capacity deviation of different areas of the lens is ≤5%, avoiding local damage to the eyes caused by ultraviolet rays after wearing, while the core index of the final product transmittance ≥92% is stable and meets the standard.

[0045] Initiator activity retention coefficient control ensures that the free radical concentration of crosslinking reaction power is moderate, avoiding incomplete crosslinking (lens easy to break) caused by insufficient initiator activity or excessive crosslinking (lens too hard, wearing uncomfortable) caused by excessive activity.

[0046] The standard of crosslinking agent activity coefficient (combined with functional group concentration, purity, and stability coefficient) can effectively avoid the safety risks of insufficient mechanical strength of the lens (such as easy to tear) and excessive solubles (such as residual monomers causing eye allergy) caused by crosslinking agent deterioration or excessive impurities.

[0047] Synergistic reaction coefficient can quickly identify "excessive reaction" (local overheating leading to internal bubbles of the lens) or "insufficient reaction" (low crosslinking degree leading to lens easy to deform) of the initiator and crosslinking agent through simple temperature difference ratio calculation, and intercept batches that may appear optical distortion (such as blurred vision) in advance.

[0048] Avoiding invalid production consumption If a batch is intercepted in advance due to "excessive dispersion coefficient of variation" (such as agglomeration of ultraviolet absorbent), the energy consumption (such as power consumption of curing furnace, operation cost of sterile workshop) and raw material loss (substrate, initiator, etc.) of subsequent processes such as curing, molding and sterilization can be saved, and the waste cost caused by unqualified products can be reduced.

[0049] Reducing quality traceability cost Each parameter (such as accelerated aging data of stability coefficient and temperature record of synergistic reaction) is a quantifiable and archivable digital index. If quality problems occur later, the historical data can be quickly traced back to "raw material batch" or "premix process", avoiding the consumption of manpower and time for full-process investigation.

[0050] Embodiment 3, based on embodiment 2, further comprises: Step S05: The process of step S4 is divided into a temperature rising section, an isothermal 1 section, an isothermal 2 section, and an isothermal 3 section, and the reference final temperature of the temperature rising section, the reference temperature of the isothermal 1 section, the reference temperature of the isothermal 2 section, and the reference temperature of the isothermal 3 section are determined; Step S06: Obtain the temperature-reference decomposition rate fitting curve of the to-be-used batch initiator, and correct the temperature-reference decomposition rate fitting curve of the to-be-used batch initiator based on the initiator activity retention coefficient; At the same temperature, the corrected decomposition rate = reference decomposition rate × initiator activity retention coefficient × initiator and crosslinking agent synergistic reaction coefficient; Step S07: Obtain the temperature-reference crosslinking rate fitting curve of the to-be-used batch crosslinking agent, and correct the temperature-reference crosslinking rate fitting curve of the to-be-used batch crosslinking agent based on the crosslinking agent activity coefficient; At the same temperature, the corrected crosslinking rate = reference crosslinking rate × crosslinking agent activity coefficient × initiator and crosslinking agent synergistic reaction coefficient; Step S08: Determine the target final temperature of the temperature rising section, the target temperature of the isothermal 1 section, the target temperature of the isothermal 2 section, and the target temperature of the isothermal 3 section based on the temperature-reference decomposition rate fitting curve of the to-be-used batch initiator and the temperature-reference crosslinking rate fitting curve of the to-be-used batch crosslinking agent.

[0051] The target final temperature of the temperature rising section = the reference final temperature of the temperature rising section ; The target temperature of the isothermal 1 section = the reference temperature of the isothermal 1 section ; The target temperature of the isothermal 2 section = the reference temperature of the isothermal 2 section ; The target temperature of the isothermal 3 section = the reference temperature of the isothermal 2 section ; The target temperature corresponds to a temperature / optimal temperature that meets the requirements of the reaction effect; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; respectively, are the corrected decomposition rates in the temperature-correction decomposition rate fitting curve of the temperature of the standby batch of initiator at the reference final temperature of the temperature-raising section, and the corrected crosslinking rates in the temperature-correction crosslinking rate fitting curve of the temperature of the standby batch of crosslinking agent at the reference final temperature of the temperature-raising section; The temperature correction index is obtained by combining experiments and data analysis; the value range of the above-mentioned temperature correction index is 0.5-1.5; The temperature of the contact lens curing process needs to be controlled in stages (temperature rise → multi-stage constant temperature), and different stages correspond to different rates of initiator decomposition and crosslinking reaction. The "reference temperature" is a benchmark value determined based on the curing process data (such as the temperature range in a large number of experiments where the initiator decomposes fully and the crosslinking is uniform) of historical qualified batches (same type of raw materials as the to-be-used batch and qualified raw materials). It provides an initial reference for the adjustment of the subsequent "target temperature". For example, its curing temperature program is: 100°C, 30 minutes; 90°C, 60 minutes; 80°C, 60 minutes; the temperature rise rate is 5-8°C / min.

[0052] The temperature-reference decomposition rate fitting curve of the to-be-used batch initiator and the temperature-reference crosslinking rate fitting curve of the to-be-used batch crosslinking agent are determined by experiments on the same kind of qualified raw materials; The beneficial effects of the above technical solutions are: The activity of initiators and crosslinking agents of different batches will have certain differences. In the scheme, the initiator activity retention coefficient and the crosslinking agent activity coefficient are introduced to correct the temperature-reference decomposition rate fitting curve of the initiator and the temperature-reference crosslinking rate fitting curve of the crosslinking agent, so as to obtain the rate fitting curve that fits the actual activity of the to-be-used batch initiator and crosslinking agent. In this way, even if there is activity fluctuation between the to-be-used batch raw materials and the historical reference raw materials, the corrected rate curve can accurately reflect the decomposition and crosslinking rates at different temperatures, providing accurate basis for determining the target temperature of each stage, thereby ensuring that the process can well adapt to different batches of raw materials and avoiding reaction out of control or unstable product quality due to differences in raw material activity.

[0053] The curing process of contact lenses involves two key steps: decomposition of initiators to produce active species and crosslinking reaction of crosslinking agents with active species. Only when the rates of initiation reaction and crosslinking reaction are well matched in each stage, can excellent products be obtained. The scheme controls the temperature in the temperature rise stage, the isothermal 1 stage, the isothermal 2 stage, and the isothermal 3 stage, and the target temperature of each stage is calculated based on the synergistic relationship between the corrected decomposition rate of the initiator and the corrected crosslinking rate of the crosslinking agent. For example, in the temperature rise stage, by adjusting the target final temperature, the ratio of the decomposition rate of the initiator and the crosslinking rate of the crosslinking agent is adjusted to meet the process requirements, laying a good foundation for the subsequent reaction; in each isothermal stage, the temperature is further precisely controlled to continuously maintain the synergistic relationship between the initiation and crosslinking reaction rates, ensuring sufficient initiation and uniform crosslinking, ultimately improving the optical performance of the contact lenses, making them have better light transmission, and optimizing the mechanical properties, so that the contact lenses have appropriate flexibility and sufficient strength, and have better comfort and durability when worn.

[0054] The reference temperature is determined based on curing process data of historical qualified batches, which is verified by a large number of experiments, can ensure that the initiator is fully decomposed and cross-linked uniformly, and is the basis for process stability. On this basis, combined with the corrected rate curve of the raw materials of the batch to be used and the temperature correction index, the target temperature of each stage is determined, which not only inherits the advantages of mature process, but also can be dynamically adjusted according to the actual situation of the raw materials of the batch to be used. This way makes the process stable and reliable, and has a certain flexibility, which can reduce the product quality fluctuations caused by improper temperature control in large-scale production, improve the repeatability of the production process, and help enterprises to produce high-quality contact lenses stably and continuously.

[0055] In any one of embodiments 1-3, on the basis of any one of embodiments 1-3, batch execution of the step S2 is performed before batch execution of the step S2, and the batch execution of the step S2 includes: Step S201: Obtain the initial stirring parameters of the base material and the ultraviolet absorber of the ultraviolet-proof contact lenses of the batch to be executed; detect the base material and the ultraviolet absorber of the batch to be executed to determine the initial stirring parameters (existing technologies can be used, such as retrieving the stirring parameters records of the same type (similar base material and ultraviolet absorber types and proportions) of ultraviolet-proof contact lenses produced by the enterprise in the past, selecting the stirring parameters of the batches with good mixing effect and producing qualified products as the initial stirring parameters of the current batch to be executed), which can be determined based on existing technologies and the next embodiment; Step S202: The base material and the ultraviolet absorber of the batch to be executed are pre-mixed for the second sampling, and the actual stirring speed is controlled to be the initial stirring speed in the second sampling pre-mixing; the stirring time of the second sampling pre-mixing is k times the initial stirring time; k is 0.1-0.3; the number of the first segments in k times the initial stirring time is greater than or equal to 3; In the second sampling pre-mixing process, the main flow mixing area is demarcated in the stirring container to detect the viscosity by sampling multiple times, a detection time-detection viscosity fitting curve is constructed, and the detection time-detection viscosity fitting curve is divided into multiple second segments, the difference between the maximum slope and the minimum slope of each second segment is less than a preset slope difference; In the second sampling pre-mixing process, the vibration speed monitored by the vibration sensor on the stirring shaft is obtained multiple times, the actual first ratio of the vibration speed of each second segment to the average slope of the second segment is obtained, and the vibration state coefficient is determined based on the actual first ratio; the multiple second segments are: agglomerated particle crushing segment, micro-particle preliminary dispersion segment, and system viscosity adaptation segment; the multiple first segments are: agglomerated particle crushing segment, micro-particle preliminary dispersion segment, and system viscosity adaptation segment; Vibration state coefficient = average value of actual first ratio ÷ reference value of first ratio; Step S203: Obtain the detection time-reference viscosity fitting curve and divide it into multiple first segments; Determine the switching matching coefficient of each second segment based on the slope of each second segment and its previous second segment, and determine the viscosity change state coefficient based on the slope comparison of the second segment with the same number and the first segment; The switching matching coefficient of the i-th second segment = (the average slope of the i-th second segment ÷ the average slope of the i-1-th second segment) ÷ (the average slope of the i-th first segment ÷ the average slope of the i-1-th first segment); The viscosity change state coefficient of the i-th second segment = the average slope of the i-th second segment ÷ the average slope of the i-th first segment; Step S204: Correct the initial stirring speed based on the second segment viscosity change state coefficient, the switching matching coefficient of the second segment, and the vibration state coefficient to obtain the required stirring speed; when the base material and the ultraviolet absorber batch of the anti-ultraviolet contact lenses to be executed are stirred, the stirring is performed at the required stirring speed and the initial stirring time.

[0056] The required stirring speed = ; The average value of all second segment viscosity change state coefficients; H is the average value of all second segment switching matching coefficients; D is the vibration state coefficient; The first speed correction index (value 0.3-1.5), the second speed correction index (value 0.2-1.0), and the third speed correction index (value 0.1-0.8) are respectively.

[0057] In the preparation process of the anti-ultraviolet contact lenses, the reference viscosity fitting curve refers to the fitting curve of the "detection time-reference viscosity fitting curve" recorded under the condition that the same base material and ultraviolet absorber as the batch to be executed are mixed uniformly (and the stirring efficiency is qualified), and the product quality is qualified (such as uniform dispersion of the ultraviolet absorber, and the lens anti-ultraviolet performance meets the standard). The reference value of the first ratio is determined based on the first segment; These indexes are determined by experiments. Select the same base material and ultraviolet absorber as the batch to be executed, set multiple different index combinations, and perform anti-ultraviolet contact lens stirring preparation experiments. Detect the quality indexes of the ultraviolet absorber dispersion uniformity and the lens anti-ultraviolet performance of each experimental product, as well as the viscosity change, segment switching matching, and vibration state during the stirring process. From them, select the index combination that can make the product quality optimal and the process most stable.

[0058] The beneficial effects of the above technical solutions are: By small batch premixing (second sampling premixing), combined with monitoring and analysis of multiple parameters such as viscosity change state coefficient, switching matching coefficient, vibration state coefficient, etc., the initial stirring speed is accurately corrected. This makes the ultraviolet absorber more uniformly dispersed in the base material, avoiding the situation of local high or low concentration, thereby ensuring the stability of the ultraviolet protection performance of the ultraviolet protection contact lenses, such as significantly reducing the difference in ultraviolet blocking rate of each area of the lens, and improving the consistency of product quality.

[0059] The reference viscosity fitting curve is based on the same raw materials and the qualified state of mixing, providing a "qualified standard" reference for the stirring process of the batch to be executed. By comparing the coefficients of the actual segmented (second segment) and the reference segment (first segment), the deviation from the "qualified state" during the stirring process of the batch to be executed can be found and adjusted in time, so that the stirring process can better adapt to the subtle differences of different batches of raw materials, enhance the stability of the process, and reduce the risk of mixing failure caused by fluctuations in raw materials or changes in equipment state.

[0060] Before mass production, the appropriate stirring speed can be determined through small-scale premixing experiments and parameter correction, without the need for a large number of full-scale trial production to adjust parameters, saving time and raw material costs. At the same time, stable and adaptive stirring process reduces subsequent rework, repair and other processes caused by uneven mixing, improves production efficiency, and ensures the smooth progress of production plans.

[0061] The premixing time is short, and the parameter monitoring, analysis and correction can be completed in a short time, quickly obtaining the required stirring speed, saving a lot of time for subsequent mass production and speeding up the production process.

[0062] In embodiment 5, based on embodiment 4, the process of obtaining the initial stirring parameters of the base material of the ultraviolet protection contact lenses and the ultraviolet absorber of the batch to be executed includes: Step S2011: detecting the refractive index of the base material of the ultraviolet protection contact lenses of the batch to be executed , the refractive index of the ultraviolet absorber of the batch to be executed , and determining the refractive index difference coefficient and the refractive index state coefficient; Refractive index state coefficient ; Refractive index difference coefficient ; is the corresponding reference value; Step S2012: detecting the viscosity of the base material of the ultraviolet protection contact lenses of the batch to be executed , the viscosity of the ultraviolet absorber of the batch to be executed , and determining the viscosity difference coefficient and the viscosity state coefficient; Refractive index state coefficient ; refractive index difference coefficient ; is the corresponding reference value; Step S2013: First sampling pre-mixing of the base material and the ultraviolet absorber of the anti-UV contact lenses to be executed in batches is performed, and the refractive index after mixing is uniform is determined , the refractive index-rotation speed coefficient is determined based on the refractive index difference coefficient and the refractive index state coefficient; refractive index-rotation speed coefficient = f (refractive index difference coefficient, refractive index state coefficient) ; is the reference value of the above-mentioned “detection time-reference viscosity fitting curve”; is the corresponding reference value (which can be determined according to the above-mentioned “detection time-reference viscosity fitting curve”); The viscosity-rotation speed coefficient is determined based on the viscosity difference coefficient and the viscosity state coefficient; viscosity-rotation speed coefficient = f (viscosity difference coefficient, viscosity state coefficient) ; is the reference value of the above-mentioned “detection time-reference viscosity fitting curve”; Step S2014: Determine the initial stirring parameter based on the refractive index-rotation speed coefficient and the viscosity-rotation speed coefficient.

[0063] Step S2014: Determine the initial stirring parameter based on the mapping database, which is to first construct a mapping database containing the correlation between “refractive index-rotation speed coefficient range, viscosity-rotation speed coefficient range” and “corresponding stirring parameter” (the mapping relationship can be determined based on the correlation formula between the stirring parameter of the qualified stirring mixing and the refractive index-rotation speed coefficient and the viscosity-rotation speed coefficient; or based on the qualified data in the experiment or historical data), when the two coefficients of the batch to be executed are obtained, the closest coefficient combination is matched in the database, and the corresponding stirring speed that can make the mixing uniform is extracted as the initial stirring parameter.

[0064] The beneficial effects of the above technical solution are: By detecting the refractive index and viscosity of the base material and the ultraviolet absorber, calculating the refractive index difference coefficient, the refractive index state coefficient, the viscosity difference coefficient, and the viscosity state coefficient, the physical property difference between the raw materials can be accurately quantified. Combined with the first sampling pre-mixing experiment, the refractive index-rotation speed coefficient and the viscosity-rotation speed coefficient that are more suitable for the actual mixing process are obtained. Based on the mapping database containing qualified data, the initial stirring parameter is matched, which can make the determined stirring speed more accurately adapt to the mixing characteristics of the raw materials to be executed, reduce the problem of uneven mixing caused by improper parameters, and make the ultraviolet absorber more uniformly dispersed in the base material.

[0065] The calculation of the refractive index and viscosity correlation coefficient covers the physical properties of different raw materials, whether it is a new batch of raw materials or raw materials with slight differences. These coefficients can be used to derive suitable stirring parameters. The mapping database stores the "coefficient-stirring parameter" correlation relationship under multiple qualified conditions, which can adapt to the stirring needs of different raw material combinations, improve the adaptability of the process to raw material batch differences and equipment fluctuations, and ensure the stability of the stirring process in batch production.

[0066] There is no need to conduct large-scale and multiple full-scale trial production to explore the stirring parameters. Only through small-batch first sampling premixing experiments, combined with previous physical property testing and coefficient calculation, and then using the mapping database to quickly match the initial stirring parameters, the time for process development and production preparation can be greatly shortened, the efficiency of production plan promotion can be improved, and the raw material loss caused by repeated trial and error can be reduced.

[0067] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A process for the preparation of an ultraviolet light protective contact lens, characterized in that: The preparation process comprises the following steps: Step S0: performing a pre-detection process; Step S1: weighing raw materials according to a formula of the anti-ultraviolet contact lenses; Step S2: stirring the base material and the ultraviolet absorber to obtain a mixture 1; Step S3: adding the initiator and the crosslinking agent to the mixture 1 and stirring to obtain a mixture 2; Step S4: pouring the mixture 2 into a curing mold and curing.

2. The preparation process of the anti-ultraviolet contact lenses according to claim 1, wherein the pre-detection process comprises the following steps: Step S01: stirring the base material and the ultraviolet absorber to obtain a pre-stirring mixture 1; Step S02: obtaining a plurality of samples by sampling the pre-stirring mixture 1 at different positions and performing light absorption detection on the samples to obtain a dispersion variation coefficient of the mixture 1; Step S03: detecting a key parameter of the crosslinking agent to determine a crosslinking agent activity coefficient; Step S04: performing an alarm when any one of the dispersion variation coefficient of the mixture 1, the initiator activity retention coefficient, and the crosslinking agent activity coefficient is not within a preset target coefficient range. The step S02 further comprises the following steps: detecting a temperature of the mixture 2, determining a mixing reaction heat based on the temperature of the mixture 2, and determining a synergistic reaction coefficient of the initiator and the crosslinking agent based on the mixing reaction heat; In the step S04, an alarm is also performed when the synergistic reaction coefficient of the initiator and the crosslinking agent is not within the preset target coefficient range.

3. The process for the preparation of anti-UV contact lenses according to claim 2, characterized in that: The preparation process further comprises the following steps: Step S05: dividing the process of the step S4 into a temperature rising section, an isothermal 1 section, an isothermal 2 section, and an isothermal 3 section, and determining a reference final temperature of the temperature rising section, a reference temperature of the isothermal 1 section, a reference temperature of the isothermal 2 section, and a reference temperature of the isothermal 3 section; 4. The process for the preparation of anti-UV contact lenses according to claim 2, characterized in that: Step S06: obtaining a temperature-reference decomposition rate fitting curve of the initiator and correcting the temperature-reference decomposition rate fitting curve of the initiator based on the initiator activity retention coefficient to obtain a temperature-corrected decomposition rate fitting curve of the initiator; Step S07: obtaining a temperature-reference crosslinking rate fitting curve of the crosslinking agent and correcting the temperature-reference crosslinking rate fitting curve of the crosslinking agent based on the crosslinking agent activity coefficient to obtain a temperature-corrected crosslinking rate fitting curve of the crosslinking agent; Step S08: determining a target final temperature of the temperature rising section, a target temperature of the isothermal 1 section, a target temperature of the isothermal 2 section, and a target temperature of the isothermal 3 section based on the temperature-corrected decomposition rate fitting curve of the initiator and the temperature-corrected crosslinking rate fitting curve of the crosslinking agent. The base material of the anti-ultraviolet contact lenses is a monomer mixture of HEMA; The weight percentage of the raw materials of the anti-ultraviolet contact lenses is as follows:

5. The process for the preparation of anti-UV contact lenses according to claim 1, characterized in that: The main base material of the contact lenses is a monomer mixture of HEMA: 90-98.8%; The ultraviolet absorber: 0.2-2.5%; The initiator: 0.3-1.0%; ​ ​ Crosslinking agent: 0.7-0.9%.

6. The preparation process of the ultraviolet-proof contact lens according to claim 1, characterized in that: The initiator is azobisisobutyronitrile, and the crosslinking agent is ethylene glycol dimethacrylate.

7. The process for making an ultraviolet light blocking contact lens according to claim 1, wherein: Before batch execution of the step S2, a stirring parameter determination process for batch execution of the step S2 is performed, and the stirring parameter determination process for batch execution of the step S2 comprises: Step S201: obtaining initial stirring parameters of the base material and the ultraviolet absorber of the ultraviolet-proof contact lens to be executed in batches; Step S202: the base material and the ultraviolet absorber of the ultraviolet-proof contact lens to be executed in batches are subjected to second sampling pre-mixing, and the actual stirring speed in the second sampling pre-mixing is controlled to be the initial stirring speed; During the second sampling pre-mixing process, the main flow mixing area is demarcated in the stirring container to perform multiple sampling detection of the viscosity, a detection time-detection viscosity fitting curve is constructed, and the detection time-detection viscosity fitting curve is divided into multiple second segments, and the difference between the maximum slope and the minimum slope of each second segment is less than a preset slope difference; During the second sampling pre-mixing process, the vibration speed monitored by the vibration sensor on the stirring shaft is obtained multiple times, the actual first ratio of the vibration speed of each second segment to the average slope of the second segment is obtained, and the vibration state coefficient is determined based on the actual first ratio; Step S203: obtaining a detection time-reference viscosity fitting curve and dividing it into multiple first segments; The switching matching coefficient of each second segment is determined based on the slope of each second segment and the slope of the previous second segment, and the viscosity change state coefficient is determined based on the slope comparison between the second segment with the same number and the first segment; Step S204: correcting the initial stirring speed based on the second segment viscosity change state coefficient, the second segment switching matching coefficient, and the vibration state coefficient to obtain a required stirring speed.

8. The preparation process of the ultraviolet-proof contact lens according to claim 7, characterized in that: When the base material and the ultraviolet absorber of the ultraviolet-proof contact lens to be executed in batches are stirred in batches, the stirring is performed at the required stirring speed and the initial stirring time; The second sampling pre-mixing stirring time is k times the initial stirring time.

9. The process for the preparation of an anti-UV contact lens according to claim 1 or 7, characterized in that: The process for obtaining the initial stirring parameters of the base material and the ultraviolet absorber of the ultraviolet-proof contact lens to be executed in batches comprises: Step S2011: detecting the refractive index of the base material of the ultraviolet-proof contact lens to be executed in batches, the refractive index of the ultraviolet absorber to be executed in batches, and determining the refractive index difference coefficient and the refractive index state coefficient; Step S2012: detecting the viscosity of the base material of the ultraviolet-proof contact lens to be executed in batches, the viscosity of the ultraviolet absorber to be executed in batches, and determining the viscosity difference coefficient and the viscosity state coefficient; Step S2013: First sampling pre-mixing of the base material of the anti-UV contact lenses to be executed in batches and the UV absorber, and determining the refractive index after mixing Determine the refractive index-rotation speed coefficient based on the refractive index difference coefficient and the refractive index state coefficient; Step S2014: determining the initial stirring parameters based on the refractive index-speed coefficient and the viscosity-speed coefficient.

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