Composition comprising aramid for soft contact lens and method for manufacturing soft contact lens using same

Abstract

The present invention relates to a composition comprising an aramid for a soft contact lens and a method for manufacturing a soft contact lens using same and, more specifically, to a composition for a soft contact lens and a method for manufacturing a soft contact lens using same, the composition comprising a colorless and transparent aramid polymer, a hydrophilic monomer, a curing agent, and an initiator. The composition comprising an aramid for a soft contact lens according to the present invention provides a soft lens that, compared with existing contact lenses, has less irritation and enables extended wear time due to an excellent water content and high oxygen permeability and is easily handled due to excellent mechanical strength.

Description

Composition for soft contact lenses containing aramid and method for manufacturing soft contact lenses using the same

[0001] The present invention relates to a composition for a soft contact lens comprising an aramid based on acrylamide having excellent moisture content and high oxygen permeability, and a method for manufacturing a soft contact lens using the same, and more particularly, to a composition for a soft contact lens comprising an acrylamide-based hydrophilic monomer and a colorless transparent aramid polymer, and a method for manufacturing a soft contact lens using the same.

[0002] Contact lenses are worn directly on the eye to correct vision and provide cosmetic effects. Depending on the material, they can be broadly divided into hard lenses and soft lenses.

[0003] Hard lenses are divided into RGP (Rigid Gas Permeable) lenses, made of PMMA (polymethylmethacrylate) and silicone compounds. While their rigidity reduces comfort, their hydrophobic nature and amorphous structure provide excellent optical and mechanical durability.

[0004] On the other hand, soft lenses are made of hydrophilic amorphous hydrogel material, have a high water content and a low contact angle with water, so they are much softer, more flexible, and more comfortable to wear than hard lenses.

[0005] However, since they are always worn or stored in a swollen state, they can tear more easily than hard lenses. Therefore, cross-linking agents are essential when manufacturing soft lenses to enhance the mechanical strength of the hydrogel.

[0006] Soft lenses using hydrogels as their raw material were initially developed using polymers based on acrylamide or acrylate monomers. However, acrylate polymers based on HEMA (hydroxyethyl methacrylate) are currently primarily used. This is because, despite the higher hydrophilicity of acrylamide hydrogels compared to HEMA-based hydrogels, their mechanical strength when swollen is lower than that of HEMA-based hydrogels, limiting the manufacture and use of soft lenses.

[0007] Therefore, if the mechanical strength of acrylamide-based hydrogels can be improved while maintaining their high water content, it will be possible to manufacture soft lenses with superior oxygen permeability and wearability compared to acrylate-based hydrogels.

[0008] The present invention aims to provide a soft lens having superior moisture content and oxygen permeability compared to existing soft lenses, thereby reducing foreign body sensation and enabling extended wearing time, while also having superior mechanical strength and being easy to handle.

[0009] The present invention provides a composition for a soft contact lens comprising a colorless transparent aramid polymer, a hydrophilic monomer, a curing agent, and an initiator.

[0010] The hydrophilic monomer includes an acrylamide-based compound, and the acrylamide-based compound is not limited thereto, but may include at least one compound selected from the group consisting of acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, 2-hydroxyethyl methacrylamide, 2-hydroxypropyl methacrylamide, N-vinyl methacrylamide, N-methylmethacrylamide, N,N-dimethylmethacrylamide, N-propylacrylamide, N-butylacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, etc., and preferably may include N,N-dimethylacrylamide.

[0011] The above acrylamide-based compound has superior hydrophilicity and hygroscopicity compared to the acrylate-based compound used in the manufacture of conventional soft contact lenses, so the polymer manufactured from the acrylamide-based compound has a significantly superior water content when hydrated compared to the polymer manufactured from the acrylate-based compound, but has weak internal cohesion and thus does not have the mechanical strength to maintain the shape of the lens.

[0012] A composition for a soft contact lens according to the present invention comprises a colorless and transparent aramid polymer, wherein the aramid polymer reinforces the mechanical strength of a hydrogel containing an acrylamide-based monomer as a main component, thereby allowing the shape of the soft contact lens to be stably maintained even when hydrated.

[0013] The above colorless transparent aramid polymer may have an elastic modulus of less than 6.6 GPa, and if the elastic modulus exceeds the above range, the hydrodynamic chain mobility (volume change) between the aramid polymer and the acrylamide polymer is greatly different upon hydration, so that an extremely high interfacial stress occurs between the two materials at the molecular level, and thus the soft contact lens cannot maintain its original lens shape upon hydration. The above colorless transparent aramid polymer preferably has an elastic modulus of less than 5.5 GPa, more preferably less than 4.55 GPa, and even more preferably 4.0 to 2.0 GPa.

[0014] The colorless transparent aramid polymer is not limited, but may include at least one diamine compound selected from 2,2'-bis(trifluoromethyl)benzidine, 4-aminophenyl sulfone, 3-aminophenyl sulfone, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] sulfone, bis[4-(3-aminophenoxy)phenyl] sulfone, and isophthaloyl chloride, terephthaloyl chloride, 4,4'-biphenyldicarbonyl chloride, naphthalene-1,4-dicarbonyl dichloride, 4,4'-oxydibenzoyl chloride, It may include a condensation reaction product of one or more dibasic acids selected from 4,4'-sulfonyldibenzoyl chloride, and preferably, it may be prepared by reacting one or more aromatic diamines selected from aromatic diamine compounds having a fluorinated alkyl group or an aromatic diamine compound having a sulfone group with a meta-structured dibasic acid, and more preferably, one or more aromatic diamines selected from 2,2'-bis(trifluoromethyl)benzidine, p-aminophenyl sulfone or m-aminophenyl sulfone, and isophthaloyl chloride may be used as the aromatic dibasic acid.

[0015] The composition for a soft contact lens according to the present invention may be composed of a weight ratio of a curing agent to a colorless transparent aramid polymer of 1 or more, and when the weight ratio of a crosslinking agent to the aramid polymer is less than 1, the lens deforms after hydration and loses its original shape.

[0016] The crosslinking agent is not limited, but may include a bifunctional acrylamide compound, and may include one or more compounds selected from N,N'-ethylenebisacrylamide, N,N'-methylenebismethacrylamide, poly(ethylene glycol) diacrylamide, and N,N'-(1,2-dihydroxyethylene)bisacrylamide, and preferably, N,N'-methylenebisacrylamide may be used.

[0017] The present invention provides a method for manufacturing a soft contact lens, comprising the steps of providing a composition for a soft contact lens comprising a colorless transparent aramid polymer, a hydrophilic monomer, a curing agent, and an initiator, injecting the composition for a soft contact lens into a mold, and heating the mold to thermally polymerize the hydrophilic monomer.

[0018] The composition for a soft contact lens including an aramid according to the present invention and the method for manufacturing a soft contact lens using the same provide a soft contact lens having a high moisture content and oxygen permeability while also having excellent mechanical strength compared to existing acrylate-based soft lenses, thereby exhibiting the effects of less foreign body sensation when wearing the soft contact lens, enabling continuous wearing, and being easy to handle during use.

[0019] Figures 1 (a) and (b) schematically show the molecular structure of a HEMA-based hydrogel before and after hydration, (c) and (d) schematically show the molecular structure of a DMA-based hydrogel before and after hydration, (e) and (f) show photographs of a HEMA-based lens, and (g) and (h) show photographs of a DMA-based lens before and after hydration. (The lens contains 1 wt% of ethylene glycol dimethacrylate as a crosslinking agent.)

[0020] Figure 2 shows a synthetic route of an aramid polymer according to the present invention and a photograph of the synthesized aramid polymer.

[0021] FIG. 3 shows photographs of (a) TFMB-IPC, (b) pAPS-IPC, and (c) mAPS-IPC films formed using an aramid polymer manufactured according to the present invention, and shows the states when the films are (d) folded and (e) twisted.

[0022] Figure 4 schematically illustrates the manufacturing process of a soft contact lens according to the present invention.

[0023] Figure 5 schematically illustrates a measuring device for measuring the mechanical properties of a soft contact lens according to the present invention.

[0024] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular includes the plural unless specifically stated otherwise. The term "comprises" as used herein does not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0025] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those skilled in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0026]

[0027] In the present invention, a soft contact lens was manufactured using a hydrogel containing an acrylamide-based monomer as a main component.

[0028] HEMA, the most commonly used polymer for the manufacture of conventional soft contact lenses, is an acrylate monomer with a hydrophilic hydroxyl group. It can be readily produced into a hydrogel through radical addition polymerization. Lenses made primarily from HEMA maintain sufficient mechanical strength for soft contact lenses due to the strong intermolecular hydrogen bonding, which maintains internal cohesion even when wet. (See Figures 1(a) and (b))

[0029] On the other hand, lenses manufactured using acrylamide-based monomers, such as dialkyl acrylamide, as their main raw material have weakened internal cohesion between molecules when wet, making them easily stretched or torn to the point where they cannot withstand their own weight. (See Figures 1(c) and (d))

[0030] This significant difference in mechanical strength between the two materials in a wet state can be explained by the non-covalent interactions between the polymer chains (PP) or between the polymer and water (PW). As illustrated in Fig. 1, in HEMA-based lenses, both PP and PW interactions are equivalent to hydrogen bonding, so that the lenses can retain water appropriately and maintain adequate internal cohesion even in a wet state. (See Fig. 1(b)) On the other hand, in dialkylacrylamide-based lenses, PW is hydrogen bonding and PP is dipole-dipole interaction, so the PW interaction is expected to be overwhelming in a wet state. (See Fig. 1(d)) Therefore, acrylamide-based lenses can retain water, but their internal cohesion is extremely reduced.

[0031] For example, a HEMA-based lens increased in size by about 1.15 times its original size after hydration and maintained its shape well (see Fig. 1(f)), but a dimethylacrylamide (DMA)-based lens increased in size by more than 1.6 times due to hydration and became so soft that it could not support its own weight and was easily crushed (see Fig. 1(h)).

[0032] However, since acrylamide-based lenses have a significantly higher water content than HEMA-based lenses, if mechanical strength is reinforced, a soft contact lens can be obtained that provides a much higher number of uses and a longer period of use along with a comfortable fit.

[0033] In the present invention, an aromatic polyamide, i.e., an aramid polymer, was used to reinforce the mechanical strength of a hydrogel containing an acrylamide-based monomer as a main component.

[0034] The above aramid polymer has thermal and chemical durability and high mechanical strength, and can have colorless and transparent characteristics, making it suitable for the manufacture of lenses. In addition, since both the aramid polymer and the acrylamide monomer are basically amide compounds, they can be expected to mix well with each other due to their high chemical affinity.

[0035]

[0036] Hereinafter, the synthesis of colorless and transparent aramid polymers, the manufacturing process of acrylamide-based soft contact lenses using the polymers, and the physical properties of the manufactured soft contact lenses will be described in detail through examples of the present invention so that those skilled in the art can easily practice the invention. However, the present invention may be implemented in various different forms and is not limited to the examples described herein.

[0037]

[0038] 1. Synthesis and characterization of colorless transparent aramid polymers

[0039] As illustrated in Fig. 2, a colorless and transparent aramid polymer was prepared using an aromatic diamine and an aromatic dibasic acid. 2,2'-bis(trifluoromethyl)benzidine (TFMB) having a fluoroalkyl group (-CF3) and p-aminophenyl sulfone (pAPS) and m-aminophenyl sulfone (mAPS) having a sulfone group were used as the aromatic diamine, and isophthaloyl chloride (IPC) was used as the aromatic dibasic acid.

[0040] In one embodiment, aromatic diamine (10 mmol) was added to a 250 mL three-necked flask equipped with a magnetic bar and filled with nitrogen gas, and dissolved in 25 mL of N,N-dimethylacetamide (DMAc). The flask was immersed in an ice bath and cooled to 0 °C, and then IPC (10 mmol) dissolved in a small amount of DMAc (5 mL) was added. The mixture was stirred at 0 °C for 1 h and at room temperature for 4 h. Finally, the resulting solution was precipitated in a methanol / water (1:1) mixture and filtered to obtain the product. Soxhlet extraction was performed using the same mixture to remove residual HCl. Three aramid polymers (TFMB-IPC, pAPS-IPC, and mAPS-IPC) were prepared using the above method.

[0041] The physical, thermal, mechanical, and optical properties of the above aramid polymers are shown in Table 1.

[0042]

[0043] a Measured in 20 wt% DMAc solvent

[0044] b Measured using a film approximately 60 μm thick

[0045]

[0046] The above aramid polymers were dissolved in N,N-dimethylacetamide (DMAc). In a 20 wt% DMAc solution, TFMB-IPC exhibited a significantly higher viscosity than the other polymers, pAPS-IPC and mAPS-IPC, suggesting that TFMB-IPC has a high molecular weight as well as high chain rigidity. mAPS-IPC exhibited a lower viscosity than the other two polymers due to the high flexibility of its polymer chain. However, all three solutions had sufficient viscosity to obtain films tens of micrometers thick by casting, and in fact, relatively thick films with a thickness of approximately 60 μm could be produced by casting onto a conventional glass substrate and then convection drying. Both films, TFMB-IPC and pAPS-IPC, had smooth surfaces and excellent appearances, and did not tear or break when pulled or bent (see Figs. 3(d) and (e)).

[0047] All three aramid polymers exhibited a tensile modulus of 2.7 GPa or higher and a tensile strength of 32 MPa or higher.

[0048] TFMB-IPC had a relatively high value compared to the other two polymers, which is thought to be due to the steric hindrance of the bulky -CF3 group in TFMB, which suppresses the rotational freedom of the polymer chain and increases the rigidity. On the other hand, pAPS-IPC and mAPS-IPC, which have a structure in which a sulfone group is sandwiched between two phenyl groups, have a structure in which two C sp2 -S sp3Since it has a single bond, it is relatively free to rotate, which increases the thermodynamic fluidity of the chain, and it is judged to have a lower value than TFMB-IPC. When pAPS-IPC and mAPS-IPC are compared, pAPS-IPC shows a higher elastic modulus than mAPS-IPC. This is thought to be because para-polymers form a more rigid chain structure than meta-polymers, as is well known from the comparison of Kevlar and Nomex. Although the elastic modulus of the above aramid polymers is lower than that of aramids used as conventional engineering plastics, it is comparable to that of colorless transparent polyimide films reported to date.

[0049] The TFMB-IPC film (see Fig. 3(a)) had a high transmittance of 86.2% at 420 nm and the lowest yellowness of 1.9.

[0050] The films of pAPS-IPC (see Fig. 3(b)) and mAPS-IPC (see Fig. 3(c)) were also colorless and transparent, and their light transmittances were quite high at 82.6 and 82.2% at 420 nm, respectively, and their yellowness indices were relatively low at 2.5 and 3.9, respectively. Although the optical performance of the aramid polymer containing the sulfone group is not as excellent as that of TFMB-IPC, it is judged to exhibit sufficient performance for use in contact lenses.

[0051]

[0052] 2. Manufacturing and Evaluation of Soft Contact Lenses Containing Aramid Polymers

[0053] Since the aramid polymers manufactured above are readily soluble in DMAc, DMA, which has a similar chemical structure to DMAc, was selected as a hydrophilic substrate for lens manufacturing. As expected, the aramid polymers were readily dissolved in DMA, one of the acrylamide monomers, at room temperature without heating, with simple stirring, up to 10 wt%, and the resulting liquid solution was colorless, transparent, and had a viscosity that made it easy to handle.

[0054] Although DMA homopolymer has a very high water content, lenses manufactured from it are prone to deformation and, in particular, tear easily when hydrated (see Fig. 1(h)). Therefore, contact lenses cannot be manufactured using DMA alone.

[0055] Accordingly, the present invention attempted to solve this problem by using a colorless, transparent aramid polymer manufactured as described above as a reinforcing agent. Furthermore, considering its affinity with DMA and the aramid polymer, N,N'-methylenebisacrylamide (MBA), which is an acrylamide compound identical to DMA but containing a difunctional group, was used as a crosslinking agent.

[0056]

[0057] 1) Manufacturing of contact lenses

[0058] DMA as an acrylamide monomer, MBA as a crosslinking agent, and the aramid polymer described above as a reinforcing agent were mixed in the weight ratios shown in Table 2, stirred for about 12 hours to completely dissolve, then 0.3 wt% of AIBN was added and stirred for another 30 minutes to prepare a contact lens composition containing the aramid polymer. 120 μL of the composition was placed into a lens mold using a micropipette, reacted in a convection oven at 90 °C for 2 hours, and then immersed in hot methanol to remove the remaining unreacted monomer and initiator, and then removed from the mold to prepare a lens (see Fig. 4).

[0059] Since MBA did not dissolve in DMA at more than 7 wt%, the content of MBA was adjusted within the range of 1 to 7 wt%.

[0060]

[0061] 2) Evaluation of physical properties of contact lenses

[0062] <Measuring shape changes during sign language>

[0063] The change in diameter of the manufactured lenses upon hydration was measured, and whether the shape of the lenses was maintained upon hydration and whether phase separation occurred between the aramid polymer and the lens after manufacturing and upon hydration were evaluated, which are shown in Table 2.

[0064] When the shape of the lens is maintained during hydration, it is indicated by ○, when the shape of the lens is maintained but slight bending deformation occurs, it is indicated by △, and when the shape of the lens is not maintained, it is indicated by ×.

[0065] <Measurement of mechanical properties>

[0066] In order to evaluate the mechanical properties of the lenses under conditions identical to actual use, the tensile strength, elastic modulus, and elongation at break of the lenses hydrated with phosphate-buffered saline (PBS) were measured using a UTM (Universal Test Machine, SHIMADZU, AGS-X 20N). The tensile properties were measured at a speed of 10 mm / min with a thickness of 0.145 mm, a width of 10 mm, and a gauge length of 10 mm, as shown in Fig. 5. The average value was obtained after five experiments for each sample.

[0067] <Measurement of moisture content>

[0068] The manufactured contact lenses were immersed in a PBS solution for 48 hours, after which surface moisture was removed. The weight of the hydrated lenses was measured, and the moisture content was determined using Equation (1) below. Each sample was tested three times, and the average value was obtained.

[0069] Moisture content (%) = 100 × (hydrated lens weight - dry lens weight) / (hydrated lens weight) (1)

[0070] <Refractive index measurement>

[0071] The refractive index of the lens was measured using an Abbe refractometer (1T(1212), Atago, Japan) according to ISO 18369-4.

[0072] <Transmittance and yellowness measurement>

[0073] The transmittance and yellowness of the lenses were measured from ultraviolet-visible (UV-Vis) spectra obtained using a JASCO V-650 spectrophotometer (JASCO, Japan).

[0074] <Oxygen permeability measurement>

[0075] Oxygen permeability was measured using a polarographic method based on ISO 18369-4 using lenses hydrated in PBS solution for 24 hours. The thickness of the center of the lens was measured using a low-pressure dial gauge (VL-50-B, Mitutoyo, Japan), and the current value was measured using an oxygen permeability analyzer (201T, Createch Rehder, USA) in a constant temperature and humidity chamber (WL1000S, Withlab, Korea) at 35°C and 98% humidity. Oxygen permeability (Dk) was calculated using the following equation (2) (where t is the thickness of the lens), and the unit of Dk is am.

[0076] (2)

[0077] The above measurements are also shown in Table 2.

[0078] All manufactured lenses were colorless and transparent, and no phase separation occurred in the dry or hydrated state.

[0079]

[0080] <Changes in form during sign language>

[0081] Looking at the cases of Examples 1 to 32 in which TFMB-IPC or pAPS-IPC was used as the aramid polymer, when the weight ratio of the crosslinker to the aramid polymer was about 1 or more, it was confirmed that the volume of the lens increased by 1.3 to 1.7 times after immersing in PBS, while the original appearance and shape were well maintained. (See Examples 2 to 4, 8, 18 to 20, 23, and 24.) However, when the weight ratio of the crosslinker to the aramid polymer was less than 1, the lens deformed after hydration and lost its original shape. (See Examples 1, 5 to 7, 9 to 17, 21, 22, and 25 to 32.)

[0082] These changes are believed to be due to the significant difference in hydrodynamic chain mobility (volume change) between the aramid polymer and the DMA matrix upon hydration, which results in extremely high interfacial stresses between the two materials at the molecular level.

[0083] Therefore, when a crosslinking agent is added in a certain amount or more, it is believed that more crosslinking points are created within the DMA matrix, and thus the chain mobility of the DMA matrix is ​​suppressed, reducing the interfacial stress between aramid polymers during hydration, thereby stably maintaining the shape of the lens.

[0084] This can be confirmed through the following facts:

[0085]

[0086] [Table 2] (continued)

[0087]

[0088] The present inventors prepared an aramid polymer (TFMB-TPC70-IPC30) using an aromatic diamine, terephthaloyl chloride (TPC), and IPC in a 7:3 dibasic acid mixture, and prepared contact lenses using the same composition as in the examples described above. When the lenses thus prepared were immersed in a PBS solution, the shape of the lenses deformed within a few minutes and the original lens shape could not be maintained. In other words, TFMB-TPC70-IPC30 is expected to have a considerable rigid chain due to its abundant para-linked structure, which induces large interfacial stress within the DMA matrix during hydration, resulting in large deformation of the lenses during hydration.

[0089] The fact that the elastic modulus and tensile strength of TFMB-TPC70-IPC30 are 6.6 GPa and 109 MPa, respectively, which are higher than the elastic modulus and tensile strength of TFMB-IPC used in Examples 1 to 16, which are 3.6 GPa and 98.6 MPa, respectively, can serve as the basis for the above-described judgment.

[0090] That is, when an aramid polymer is included, it can be seen that an appropriate elastic modulus is required for the aramid polymer to act as a reinforcing agent for the lens in a hydrated state while at the same time stably maintaining the shape of the lens.

[0091] This interpretation can also be applied to examples 33 to 48, where mAPS-IPC, which has the lowest elastic modulus and tensile strength among aramid polymers, was used.

[0092] When mAPS-IPC is used, it exhibits more morphological stability upon hydration than when TFMB-IPC and pAPS-IPC are used (see Examples 33 to 36, 38 to 40, 44), including cases where the weight ratio of crosslinker to aramid polymer is less than about 1 (0.4 for Example 33, 0.6 for Example 38, and 0.9 for Example 44).

[0093] That is, since mAPS-IPC has a relatively lower elastic modulus and tensile strength than TFMB-IPC and pAPS-IPC, it is judged that it induces a relatively lower interfacial stress within the DMA matrix than TFMB-IPC and pAPS-IPC even when hydrated, and thus maintains the shape stability of the lens even when the content of the crosslinking agent is relatively low.

[0094] In the present invention, when MBA exceeds 7 wt%, it does not dissolve in DMA, so, except in the case of mAPS-IPC, when the content of the aramid polymer exceeds 7 wt%, it is not possible to obtain a lens whose shape is stably maintained after hydration.

[0095] Mechanical properties

[0096] Examining the tensile properties of the manufactured lenses, regardless of the type of aramid polymer, as the aramid polymer content increased and as the cross-linking agent content increased, the elastic modulus and tensile strength increased. For the same aramid polymer content, TFMB-IPC exhibited higher elastic modulus and tensile strength than pAPS-IPC and mAPS-IPC, which is believed to be due to the physical properties of TFMB-IPC, as shown in Table 1.

[0097] Among the manufactured lenses, when comparing the lenses that maintained their shape after hydration with the existing HEMA-based lenses (elastic modulus of 1.24 MPa, tensile strength of 0.41 MPa), the acrylamide-based lenses including the aramid polymer manufactured according to the present invention exhibited significantly higher elastic modulus (Example 8: 8.13 MPa, Example 24: 5.75 MPa, Example 44: 1.37 MPa) and tensile strength (Example 8: 1.62 MPa, Example 24: 0.92 MPa, Example 44: 0.81 MPa). Moreover, the elastic modulus of the present lenses was up to 8 times higher than that of commercial soft contact lenses.

[0098] However, the elongation at break was less than 100%, which was slightly lower than that of conventional HEMA-based soft contact lenses (approximately 124%).

[0099] <Transmittance and yellowness>

[0100] The manufactured lenses exhibited high transmittance of more than 81% and low yellowness of less than 6.5 at a wavelength of 420 nm, and the transmittance decreased and the yellowness increased as the aramid polymer content increased.

[0101] When comparing the lenses with the highest tensile strength by aramid polymer among the lenses that maintained their shape after hydration, when TFMB-IPC was used, the transmittance was 93.5% and the yellowness was the lowest at 1.63 (see Example 8), when pAPS-IPC was used, the transmittance was 93.5% and the yellowness was 1.83 (see Example 24), and when mAPS-IPC was used, the transmittance was 88.6% and the yellowness was 4.72 (see Example 44).

[0102] Refractive index

[0103] In soft contact lenses, a high refractive index, along with high transmittance, is an important performance indicator. Since the lenses manufactured according to the present invention are a blend of two materials—an aramid polymer and DMA—the refractive index can be affected by the blend ratio and microphase separation of the two materials.

[0104] The refractive index tends to increase as the content of the aramid polymer and the curing agent increases, and when compared among the lenses that maintained their shape after hydration by aramid polymer, it was 1.400 when TFMB-IPC was used (see Example 8), 1.392 when pAPS-IPC was used (see Example 24), and 1.390 when mAPS-IPC was used (see Example 44). This value was slightly lower than the value of the conventional HEMA-based lens (1.438). However, considering that the acrylamide-based lens according to the present invention contains much more water than the HEMA-based lens as described below and that water has a lower refractive index (1.33), the refractive index still shows a high value despite the high water content, and it is believed that this high refractive index is due to the directionality and hydrophobicity of the aramid polymer.

[0105] <Moisture content>

[0106] As the content of aramid polymer or cross-linking agent increased, the moisture content decreased slightly. However, the moisture content of all manufactured lenses was very high, exceeding 63%, as evidenced by the rapid increase in lens size after hydration. This high moisture content is due to the lenses being manufactured based on the highly hygroscopic acrylamide monomer.

[0107] When comparing the shape retention rates of lenses that retained their shape after hydration by aramid polymer, the rates were 78.2% when TFMB-IPC was used (see Example 8), 78.9% when pAPS-IPC was used (see Example 24), and 83.0% when mAPS-IPC was used (see Example 44). This is approximately 1.5 times the moisture content of conventional HEMA-based lenses (49.6%), confirming that the moisture content was significantly improved.

[0108] This improvement in water content is attributed to the inherently high hygroscopicity of the acrylamide-based matrix (DMA matrix), even when containing hydrophobic aramid polymers. This is further evidenced by the fact that water dropped onto the lens surface for contact angle measurement is immediately absorbed by the lens, making contact angle measurement difficult.

[0109] Oxygen permeability

[0110] The acrylamide-based lens according to the present invention had significantly higher oxygen permeability than the HEMA-based lens. When comparing the lenses that maintained their shape after hydration by aramid polymer, the maximum oxygen permeability was 27.2 Dk when TFMB-IPC was used (see Example 2), 28.4 Dk when pAPS-IPC was used (see Example 18), and 38.8 Dk when mAPS-IPC was used (see Example 33). This is approximately 2.4 to 3.4 times higher than the oxygen permeability (11.4 Dk) of a conventional HEMA-based lens. Since water present in a hydrogel contact lens serves to supply oxygen to the lens, the higher the water content of the lens, the higher the oxygen permeability. Therefore, the high oxygen permeability of the lens according to the present invention is believed to be due to the increase in the amount of dissolved oxygen due to the relatively high hygroscopicity of the DMA matrix.

[0111]

[0112] The above examples disclose using DMA as a hydrophilic acrylamide monomer, but the hydrophilic acrylamide monomer may be one or more compounds selected from the group consisting of acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, 2-hydroxyethyl methacrylamide, 2-hydroxypropyl methacrylamide, N-vinyl methacrylamide, N-methylmethacrylamide, N,N-dimethylmethacrylamide, N-propylacrylamide, N-butylacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, etc., but is not limited thereto.

[0113] In the above examples, only the case where 2,2'-bis(trifluoromethyl)benzidine, p-aminophenyl sulfone or m-aminophenyl sulfone is used as an aromatic diamine for the aramid polymer and isophthaloyl chloride is used as an aromatic dibasic acid is described. However, the aramid polymer is not limited to a colorless and transparent aramid polymer, and one or more compounds selected from an aromatic diamine monomer having a fluorinated alkyl group or an aromatic diamine monomer having a sulfone group may be used.

[0114] In addition, as aromatic diamines, one or more compounds selected from among 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] sulfone, bis[4-(3-aminophenoxy)phenyl] sulfone, and as aromatic dichlorides, one or more compounds selected from among terephthaloyl chloride (TPC), 4,4'-biphenyldicarbonyl chloride, naphthalene-1,4-dicarbonyl dichloride, 4,4'-oxydibenzoyl chloride, 4,4'-sulfonyldibenzoyl chloride, etc. can be used.

[0115] In addition, in the above example, the case where N,N'-methylenebisacrylamide is used as a crosslinking agent is described, but various bifunctional acrylamide compounds can be used as the crosslinking agent, and one or more compounds selected from N,N'-ethylenebisacrylamide, N,N'-methylenebismethacrylamide, poly(ethylene glycol) diacrylamide, N,N'-(1,2-dihydroxyethylene)bisacrylamide, etc. can be used, but are not limited thereto.

[0116] In addition, in the above example, the case where AIBN, an azo compound, was used as a thermal polymerization initiator was described, but one or more compounds selected from organic peroxides, hydroperoxides, etc., such as BPO, may be used as the thermal polymerization initiator, but is not limited thereto.

[0117]

[0118] A composition for a soft contact lens comprising an aramid according to the present invention and a method for manufacturing a soft contact lens using the same provide a soft contact lens having a higher moisture content and oxygen permeability than existing HEMA-based lenses.

[0119] The present invention relates to a composition for a soft contact lens containing an aramid and a method for manufacturing a soft contact lens using the same, and provides a soft contact lens having a high moisture content and oxygen permeability while also having excellent mechanical strength compared to existing acrylate-based soft lenses, and exhibits the effects of having less foreign body sensation when wearing the soft contact lens, allowing continuous wearing, and being easy to handle during use, and therefore has industrial applicability.

Claims

1. A composition for soft contact lenses comprising a colorless transparent aramid polymer, a hydrophilic monomer, a curing agent and an initiator.

2. A composition for a soft contact lens according to claim 1, characterized in that the colorless transparent aramid polymer has an elastic modulus of less than 6.6 GPa.

3. In claim 1, The above colorless transparent aramid polymer is at least one diamine compound selected from 2,2'-bis(trifluoromethyl)benzidine, 4-aminophenyl sulfone, 3-aminophenyl sulfone, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] sulfone, bis[4-(3-aminophenoxy)phenyl] sulfone, and isophthaloyl chloride, terephthaloyl chloride, 4,4'-biphenyldicarbonyl chloride, naphthalene-1,4-dicarbonyl dichloride, 4,4'-oxydibenzoyl chloride, 4,4'-sulfonyldibenzoyl A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that it comprises a condensation reaction product of one or more hydrochloric acid salts selected from chloride.

4. A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that in claim 3, the diamine compound comprises at least one compound selected from 2,2'-bis(trifluoromethyl)benzidine, p-aminophenyl sulfone, or m-aminophenyl sulfone, and the dicarboxylic acid salt comprises isophthaloyl chloride.

5. A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that the hydrophilic monomer of claim 1 is an acrylamide-based compound.

6. A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that in claim 5, the acrylamide-based compound comprises at least one compound selected from the group consisting of acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, 2-hydroxyethyl methacrylamide, 2-hydroxypropyl methacrylamide, N-vinyl methacrylamide, N-methylmethacrylamide, N,N-dimethylmethacrylamide, N-propylacrylamide, N-butylacrylamide, N,N-dimethylaminopropyl acrylamide, and N,N-dimethylaminopropyl methacrylamide.

7. A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that the crosslinking agent according to claim 1 comprises a bifunctional acrylamide-based compound.

8. A composition for a soft contact lens comprising a colorless transparent aramid polymer, characterized in that the bifunctional acrylamide compound of claim 7 comprises at least one compound selected from N,N'-ethylenebisacrylamide, N,N'-methylenebismethacrylamide, poly(ethylene glycol) diacrylamide, and N,N'-(1,2-dihydroxyethylene)bisacrylamide.

9. A composition for a soft contact lens comprising a colorless transparent aramid polymer according to claim 1, characterized in that the weight ratio of the curing agent to the colorless transparent aramid polymer is 1 or more.

10. A step of providing a composition for a soft contact lens comprising a colorless transparent aramid polymer according to any one of claims 1 to 9, A step of injecting the above soft contact lens composition into a mold, A method for manufacturing a soft contact lens, comprising the step of heating the mold to thermally polymerize the hydrophilic monomer.

11. A soft contact lens manufactured by the manufacturing method according to claim 10.

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