JP5432133B2 - Monomer composition for silicon hydrogel for soft contact lens and soft contact lens produced by the monomer composition - Google Patents

Description

The present invention relates to a soft contact lens made of silicon hydrogel, and more specifically, 2-hydroxyethyl methacrylate and N, N -bis which is a silicon monomer. The present invention relates to a silicon hydrogel composition for a soft contact lens containing (trimethylsilyl) acrylamide ( N, N- Bis (trimethylsilyl) acrylamide) and a soft contact lens produced by the composition.

  Generally, contact lenses are broadly classified into hard lenses based on methyl methacrylate (MMA) and soft lenses based on 2-hydroxyethyl methacrylate (HEMA). However, the use of soft lenses having relatively excellent general lens characteristics such as oxygen permeability and moisture content is spreading. This is because, unlike MMA, HEMA has a hydroxy group that is a typical hydrophilic molecular structure in the monomer and has a high water content (see Non-Patent Document 1).

  On the other hand, hydrogel means a cross-linked polymer containing a large amount of water in an equilibrium state, but is a substance having many biomedical applications such as a medical polymer for contact lenses (see Patent Document 1). ).

At present, most hydrogels used in lenses are produced by radical-type thermal polymerization reaction after using 2-hydroxyethyl methacrylate (HEMA) as a monomer and mixing with a small amount of a crosslinking agent. A lens made of such a material is hydrophilic with a moisture content of about 40% due to the characteristics of the material, and since it is soft, there is little sense of foreign matter when worn attached to the cornea, and there is less pressure on the cornea. It is. However, the mechanical strength is weak and oxygen permeability is limited to about 10 Dk [10 ⁻¹¹ cm ² / sec) (mlO ₂ mmHg)]. There are problems such as protein adhesion (see Non-Patent Document 2 and Patent Document 2).

As is well known, since the wearing feeling of a lens is closely related to the moisture content, various developments for increasing the moisture content have been attempted, and some of them have been commonly used. In particular, using a water-soluble monomer such as N-vinyl-2-pyrrolidone (NVP), N, N-dimethylacrylamide (N, N), etc., water content 80%, an oxygen permeability constant of about ^{40Dk [10 -11 cm 2 / sec} ) (mlO 2 mmHg)] and, improved highly hydrous products have been developed. However, soft lenses with high water content have a strong feeling of dryness, weak materials, inferior optical calibration ability, and there are disadvantages in the process of inserting and removing lenses, and they are mainly used only as disposable lenses. It is not suitable for long-term use (see Non-Patent Document 3).

  On the other hand, methacrylic polymers containing siloxane or fluorine used for the production of RGP contact lenses (Rigid Gas Permeable Contact Lenses) are hard materials and have excellent wear feeling, particularly high oxygen permeability, and affect the cornea. There are few side effects like corneal edema compared with the conventional polymethylmethacrylate (PMMA). However, since siloxane or fluorine-based polymer is a typical hydrophobic polymer, there is a disadvantage that it does not get wet when applied to a contact lens. In addition, since the RGP contact lens is hard and has an inherent shape, various side effects and complications may occur due to corneal distortion and tear circulation disturbance. In addition, the RGP contact lens has the disadvantages that it is low in strength, difficult to manufacture, high in cost, and easily gets dirty and scratched when worn.

  Therefore, in order to solve the problems of contact lenses that are widely used at present, development of a soft lens (silicon hydrogel soft lens) made of a hydrogel containing a silicon system and having excellent oxygen permeability has begun. Commercialized for the first time in 1998, this silicon hydrogel soft lens rapidly increased in market share, reaching about $ 150 million in 2003 (see Non-Patent Document 4).

  Silicon hydrogel is produced by copolymerization of a hydrophilic monomer such as HEMA and a silicon-containing monomer. A general silicon monomer has extremely high hydrophobicity, and when copolymerized with a hydrophilic monomer such as HEMA, it is difficult to maintain sharpness due to a phase separation phenomenon. Therefore, in order to overcome this, a compatibilizing agent for improving the compatibility of hydrophilicity and hydrophobicity must be developed and used. As a compatibilizer, PBVC (poly [dimethylsiloxy] di [silylbutanol] bis [vinyl carbamate), silicon macromer is used, but it requires a high development cost, a large molecular weight, a high viscosity, and is inconvenient at the time of lens production. There is a problem.

  In general, silicone resin is restricted to use in hydrophobic and hydrogel lenses to reduce the water content, and the surface of the lens is hydrophobic, so the surface is treated with oxygen plasma through post-processing. If it does not become hydrophilic, a problem occurs in lens wearability, and there is a problem that the protein is adsorbed on the lens surface.

  Silicon hydrogel also has a low elastic modulus due to its material properties, so the restoring force of the contact lens form is low. Due to the increase in hydrophobicity of the lens surface due to the silicon content, the epithelial tissue of the cornea and the lens are compatible with each other. And the lens adheres to the cornea.

US Patent No. 4300820 US Pat. No. 6,096,138

Refojo et al. , J .; Appl. Poly. Sci. 9: 2425 (1965) Wilson et al. , Encyclo. of Chem. Tech. 7: 192 (1976) Refojo et al. , Cont. & Intracular Lens Med. J. et al. , 1:36 (1975) Optician 2005

  The present invention is to solve the above-mentioned problems, and in order to hydrophilize a hydrophobic silicon-based monomer, the oxygen permeability of the lens is increased by polymerizing with a hydrophilic monomer. The purpose is to improve.

  Another object of the present invention is to provide N-vinyl-2-pyrrolidone (N-Vinyl-2-pyrrolidone (NVP> 99%: aldrich)) or N, N-dimethylacrylamide (N, N-Dimethylacrylamide (DMA). : Aldrich)) and adding water appropriately, it can be made excellent in light transmission without using a compatibilizer, and there is a problem in wearing without performing a separate surface treatment. It is an object of the present invention to provide a silicone hydrogel composition for a soft contact lens that does not occur and a soft contact lens manufactured by the composition.

Above and / or other aspects of the present invention, a silicon N represented by 2-hydroxyethyl methacrylate (2-Hydroxyethyl methacrylate) and the following formula (1), N - bis (trimethylsilyl) acrylamide (silicone N, N It is achieved by providing a silicone hydrogel composition for a soft contact lens comprising a bis (trimethylsilyl) acrylamide) monomer.

According to another aspect of the present invention, the content of N, N -bis (trimethylsilyl) acrylamide in the composition is 10% by weight or less.

  According to another aspect of the present invention, the composition includes ethylene glycol dimethacrylate.

According to another aspect of the present invention, the content of N, N -bis (trimethylsilyl) acrylamide in the composition is 10% by weight or less, and the content of ethylene glycol dimethacrylate is 0.5% by weight or less. is there.

  According to another aspect of the present invention, the composition contains divinyl benzene.

According to another aspect of the present invention, the content of N, N -bis (trimethylsilyl) acrylamide in the composition is 10% by weight or less, and the content of divinylbenzene is 0.4% by weight or less.

Further, according to another aspect of the present invention, the composition contains N-vinyl-2-pyrrolidone and N, N-dimethylacrylamide (N, N-dimethylacrylamide). Including.

According to another aspect of the present invention, the content of N, N -bis (trimethylsilyl) acrylamide in the composition is 5% by weight or less, and the content of ethylene glycol dimethacrylate is 0.4 to 0.7. The content of N-vinyl-2-pyrrolidone is 45% by weight or less.

  According to another aspect of the present invention, the composition contains N-vinyl-2-pyrrolidone.

According to another aspect of the present invention, the content of N, N -bis (trimethylsilyl) acrylamide in the composition is 5% by weight or less, and the content of divinylbenzene is 0.3 to 0.5% by weight. The content of N-vinyl-2-pyrrolidone is 35% by weight or less.

  According to another aspect of the present invention, the composition includes N, N-dimethylacrylamide (N, N-dimethylacrylamide).

According to another aspect of the present invention, in the above composition, the content of N, N -bis (trimethylsilyl) acrylamide is 5% by weight or less, and the content of ethylene glycol dimethacrylate is 0.4% by weight or less. The content of N, N-dimethylacrylamide is 40% by weight or less.

  According to another aspect of the present invention, the composition includes N, N-dimethylacrylamide (N, N-dimethylacrylamide).

According to another aspect of the present invention, in the above composition, the content of N, N -bis (trimethylsilyl) acrylamide is 5% by weight or less, and the content of divinylbenzene is 0.4% by weight or less, The content of N, N-dimethylacrylamide is 30% by weight or more.

  Also, the foregoing and / or other aspects of the invention are achieved by providing a soft contact lens made from the above composition.

  As described above, according to the silicone hydrogel composition for a soft contact lens of the present invention and the soft contact lens manufactured by the composition, it is used to calibrate myopia, hyperopia, astigmatism, etc. by directly contacting the eyeball. A hydrophilic contact lens capable of correcting the visual acuity, which has a high water content of 40 to 70%, a high oxygen permeability (50 to 100 Dk), and a good elasticity of 200 to 400% (Elongation) And has excellent light transmission and provides comfort for wearers who wear contact lenses for a long time, minimizing eye health, foreign body feeling, dryness, corneal pressure, etc., corneal edema and other The incidence of disease can be reduced.

  The silicon hydrogel soft contact lens according to the present invention has both the merit of an oxygen permeable hard lens (RGP lens) excellent in oxygen permeability and the soft lens of a soft wearing feeling. It can be worn continuously for 2 weeks to 1 month, and the inconvenience of the conventional lens that must be worn and detached every day can be solved.

  Additional aspects and advantages of the general inventive concept are, in part, as set forth below, and in part are apparent from the description below, or the general invention. It is possible to grasp if the concept of is implemented.

The present invention is mainly composed of 2-hydroxyethyl methacrylate (2-hydroxyethyl methacrylate (BISOMER HEMA ULTRA: Cognis)), which is a hydrophilic monomer as a main raw material, and N, a silicon-based monomer for improving oxygen permeability . N -bis (trimethylsilyl) acrylamide ( N, N- Bis (trimethylsilyl) acrylamide), N-vinyl-2-pyrrolidone (NVP> 99%: Aldrich) for enhancing hydrophilicity )) Or N, N-dimethylacrylamide (N, N-Dimethylacrylamide (DMA: Aldrich))) a water-soluble monomer and a small amount of a crosslinking agent, ethylene glycol dimethacrylate (E styrene glycol dimethylacrylate (EGDMA> 98%: Aldrich)) or divinylbenzene (Dvinyl benzen (DVB> 80%: Aldrich))) monomer, and a radical initiator 2,5-dimethyl- It is a copolymer produced by a thermal polymerization reaction of 2,5-di (2-ethylhexanoylperoxy) hexane (2,5-dimethyl-2,5-di (2-ethylhexanoyl peroxy) hexane). Is a very long molecular structure in which small units called monomers are repeatedly linked, and is a chemically linked form (three-dimensional structure) of these monomers.

  Since the contact lens has a moisture content of 40 to 70% and is very hydrophilic, no special surface treatment was performed and no compatibilizer was used. Contact lenses can be worn for two weeks because the material is not weak despite the high water content.

The oxygen permeability is as high as 50 to 100 Dk [10 ⁻¹¹ cm ² / sec) (mlO ₂ mmHg)], has no side effects through many clinical tests, is easy on the eyes, and does not cause problems even when worn for a long time.

  The physical properties of the fragile material possessed by the silicon hydrogel contact lens are improved, and the numerical values are as follows.

Elasticity (Elongation) 200-400%, Young's modulus (Young Modulus) 50-65 g / mm ² , Tensile strength 80-110 g / mm ² , Toughness (Toughness) 120-145 g / mm ² , contact lens It has very good physical properties.

  Hereinafter, the present invention will be described in more detail through examples. These examples are for explaining the invention more specifically, and it is normal knowledge in the technical field to which the present invention belongs that the scope of the present invention is not limited by these examples due to the gist of the present invention. Is evident in those having.

Example 1
Polymerization of N, N -bis (trimethylsilyl) acrylamide and 2-hydroxyethyl methacrylate

The amount of N, N -bis (trimethylsilyl) acrylamide was increased from 10 g to 90 g in units of 10 g, and the amount of 2-hydroxyethyl methacrylate was decreased from 90 g to 10 g in units of 10 g while mixing the solution. Manufactured. 0.1 g to 1 g of 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (2,5-dimethyl-2,5-di (2-ethylhexylyloxy) hexane) as an initiator is dissolved. And polymerized at 110 ° C. for 30 minutes.

As a result, when 0.2 g (0.2 wt%) or more of initiator was used, polymerization was performed regardless of the amount, but it was not involved in transparency (compatibility). It is cured with 10 g (10 wt%) or more of N, N -bis (trimethylsilyl) acrylamide, but has poor compatibility and becomes an opaque milk color. As the amount of N, N -bis (trimethylsilyl) acrylamide used increases, the curability decreases and the polymer becomes softer.

In the main polymerization, it is preferable to use 0.2 g (0.2 wt%) of an initiator. Since N, N -bis (trimethylsilyl) acrylamide has a high degree of crosslinking, curing occurs even without a crosslinking agent. It was found that the compatibility (transparency) was good when hydroxyethyl methacrylate and N, N -bis (trimethylsilyl) acrylamide monomer were 10 g (10 wt%) or less.

(Example 2)
Polymerization of N, N -bis (trimethylsilyl) acrylamide with N-vinyl-2-pyrrolidone

A mixed solution was prepared while increasing the amount of N, N -bis (trimethylsilyl) acrylamide from 10 g to 90 g in units of 10 g and decreasing the amount of N-vinyl-2-pyrrolidone from 90 g to 10 g in units of 10 g. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane was dissolved in an amount of 0.1 g to 1 g and polymerized at 110 ° C. for 30 minutes.

As a result, regardless of the amount of initiator used, it is not cured, and as the content of N, N -bis (trimethylsilyl) acrylamide increases, the curability is inferior. It became sticky.

In this polymerization, N, N -bis (trimethylsilyl) acrylamide and the water-soluble monomer N-vinyl-2-pyrrolidone are not cured and cannot be applied to a lens and cured. It was found that a cross-linking agent was necessary for this purpose.

(Example 3)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate

While increasing the amount of N, N -bis (trimethylsilyl) acrylamide from 10 g to 90 g in units of 5 g and decreasing the amount of 2-hydroxyethyl methacrylate from 90 g to 10 g in units of 5 g, 0.1 g to 1 g of crosslinking A mixed solution of the ethylene glycol dimethacrylate was prepared. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 g) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, an increase in the amount of ethylene glycol dimethacrylate improves transparency (compatibility) and curability, but weakens the elastic force and causes ethylene glycol dimethacrylate of 0.5 g (0.5 wt%) or less. Thus, a polymer enough to be applied to the lens was produced. It is cured with 20% by weight or less of N, N -bis (trimethylsilyl) acrylamide and becomes transparent. However, at 10% by weight to 20% by weight or less, the degree of water absorption after hydration was not good. The hydration state was good at 10 wt% or less. When it is 20 wt% or more, it is cured transparently, but after hydration, it becomes opaque and becomes fragile.

  In the main polymerization, use of the ethylene glycol dimethacrylate as a crosslinking agent increases the degree of crosslinking to improve transparency (compatibility), and increases the curability of the polymer to increase the strength. It has been found that the use of less than 0.5 wt% ethylene glycol dimethacrylate is suitable for lens applications.

When polymerizing 10 wt% or less of N, N -bis (trimethylsilyl) acrylamide, 90 wt% or more of 2-hydroxyethyl methacrylate and 0.5 wt% or less of ethylene glycol dimethacrylate as a crosslinking agent, a compatible and transparent curing It was found that the polymer was found to be in a good state of hydration and could be applied to a lens having some elasticity.

Example 4
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate and divinylbenzene

While increasing the amount of N, N -bis (trimethylsilyl) acrylamide from 10 g to 90 g in 5 g units and decreasing the amount of 2-hydroxyethyl methacrylate from 90 g to 5 g in 5 g units, 0.1 g to 1 g of crosslinking. A mixed solution of the agent divinylbenzene was prepared. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 g) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, an increase in the amount of divinylbenzene used improves the transparency (compatibility) and curability, but weakens the elastic force and is applied to the lens with 0.4 g (0.4 wt%) or less of divinylbenzene. As much polymer as possible was made. It is cured with 20 wt% or less of N, N -bis (trimethylsilyl) acrylamide and becomes transparent. However, when it is 10 wt% to 20 wt% or less, the degree of water absorption is not good after hydration. In 10 wt% or less, the hydration state was good. If it is 20 wt% or more, it is cured transparently, but after hydration, it becomes opaque and becomes fragile.

  In the main polymerization, use of the crosslinking agent divinylbenzene increases the degree of crosslinking to improve transparency (compatibility), and increases the curability of the polymer to increase the strength. It has been found that the use of less than 0.4 wt% divinylbenzene is suitable for lens applications.

Transparency and water absorption at the time of polymerization of 10% by weight or less of N, N -bis (trimethylsilyl) acrylamide, 90% by weight or more of 2-hydroxyethyl methacrylate and 0.4% by weight or less of divinylbenzene as a crosslinking agent Thus, it was found that an elastic polymer can be produced.

  Compared to Example 3, it can be seen that the use of divinylbenzene is better due to the compatibility (transparency) of ethylene glycol dimethacrylate.

(Example 5)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone and ethylene glycol dimethacrylate

  In Example 3, the water content of the polymer was adjusted to improve hydrophilicity, and the water-soluble monomer N-vinyl-2-pyrrolidone was added to confirm the degree of polymerization between substances. did.

N, N -bis (trimethylsilyl) acrylamide was increased from 5 wt% to 50 wt% in 5 wt% units, the amount of 2-hydroxyethyl methacrylate was decreased from 90 wt% to 10 wt% in 5 wt% units, and N-vinyl- While increasing 2-pyrrolidone in units of 5 wt% to 5 wt%, a 0.1 wt% to 1 wt% crosslinker ethylene glycol dimethacrylate mixed solution was prepared. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, 5 wt% to 10 wt% N, N -bis (trimethylsilyl) acrylamide, 50 wt% or less 2-hydroxyethyl methacrylate, 40 wt% or more N-vinyl-2- 1 wt% of the ethylene glycol dimethacrylate crosslinking agent. Transparently cured by polymerization of pyrrolidone. However, the polymer was brittle and after hydration, it was not elastic and fragile. In the case of 0.4 wt-0.9 wt% cross-linking agent, 5 wt% or less N, N -bis (trimethylsilyl) acrylamide, 5 wt% -90 wt% 2-hydroxyethyl methacrylate, 5 wt% -40 wt% N-vinyl. Transparently cured by polymerization of -2-pyrrolidone. In particular, the polymer using 0.4 wt% to 0.7 wt% of the crosslinking agent had good water absorption and elasticity after hydration.

  Increasing the amount of N-vinyl-2-pyrrolidone used increased the water content and improved the compatibility between the substances, improving the transparency. N-vinyl-2-pyrrolidone having a content of 45 wt% or less has good compatibility and was cured to produce a transparent polymer, and the moisture content was 38% to 55%. With 45 wt% or more of N-vinyl-2-pyrrolidone, a polymer having a high water content of 55 wt% or more was obtained.

In this polymerization, it was found that the use of 5% or less of N, N -bis (trimethylsilyl) acrylamide is a polymer having good transparency, elasticity and water absorption, and is suitable for lens application.

  Use of the cross-linking agent ethylene glycol dimethacrylate increases the degree of cross-linking, improves transparency (compatibility), increases the curability of the polymer, increases the strength, and weakens the elastic force of the lens after hydration. It was. The use of 0.4 wt% to 0.7 wt% ethylene glycol dimethacrylate has been found to be suitable for lens applications.

  Increasing the amount of N-vinyl-2-pyrrolidone improves the compatibility between substances and improves transparency, but increases the water content and weakens the elasticity and tensile strength of the polymer. It was. The use of N-vinyl-2-pyrrolidone of 45 wt% or less is a polymer having a moisture content of 38% to 55%, and has good elasticity and good wettability, so that it may be suitable for lens applications. all right.

[0067]
(Example 6)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone and divinylbenzene
In Example 4, the water content of the polymer was adjusted to improve hydrophilicity, and water-soluble monomer N-vinyl-2-pyrrolidone was added in order to confirm the degree of polymerization between substances. For comparison with ethylene glycol dimethacrylate, the crosslinking agent of Example 5, this is done using divinylbenzene.

  In Example 4, the water content of the polymer was adjusted to improve hydrophilicity, and water-soluble monomer N-vinyl-2-pyrrolidone was added in order to confirm the degree of polymerization between substances. For comparison with ethylene glycol dimethacrylate, the crosslinking agent of Example 5, this is done using divinylbenzene.

N, N -bis (trimethylsilyl) acrylamide was increased from 5 wt% to 50 wt% in units of 5 wt%, and the amount of 2-hydroxyethyl methacrylate was decreased from 90 wt% to units of 5 wt% to obtain N-vinyl-2-pyrrolidone A mixed solution of 0.1 wt% to 1 wt% of a cross-linking agent divinylbenzene was manufactured. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, with 1 wt% of divinylbenzene as a crosslinking agent, 5 wt% to 10 wt% of N, N -bis (trimethylsilyl) acrylamide, 50 wt% to 90 wt% or less of 2-hydroxyethyl methacrylate, 10 wt% or more of N-vinyl-2 -Cured transparently by polymerization of pyrrolidone. However, the polymer was brittle and after hydration, it was not elastic and fragile. When the cross-linking agent is 0.4 wt% to 0.9 wt%, 5 wt% or less N, N -bis (trimethylsilyl) acrylamide, 5 wt% to 90 wt% or less 2-hydroxyethyl methacrylate, 5 wt% to 40 wt% or less N-vinyl. Transparently cured by polymerization of -2-pyrrolidone. In particular, the polymer using 0.4 wt% to 0.7 wt% of the crosslinking agent had good water absorption and elasticity after hydration.

  Increasing the amount of N-vinyl-2-pyrrolidone used increased the water content and improved the compatibility between the substances, improving the transparency. N-vinyl-2-pyrrolidone having a content of 35 wt% or less has good compatibility, and was cured to produce a transparent polymer, and the moisture content was 38% to 55%. With N-vinyl-2-pyrrolidone of 35 wt% or more, a polymer having a high water content of 55 wt% or more was obtained.

In this polymerization, it was found that the use of 5% or less of N, N -bis (trimethylsilyl) acrylamide is a polymer having good transparency, elasticity and water absorption, and is suitable for lens application.

  The use of divinylbenzene as a cross-linking agent further improves the transparency (compatibility) with a higher degree of cross-linking than the ethylene glycol dimethacrylate of Example 5, increases the curability of the polymer to increase the strength, and after hydration, The elastic force of the lens was weakened, and the size could be made smaller than the use of ethylene glycol dimethacrylate. It has been found that the use of 0.3 wt% to 0.5 wt% of divinylbenzene is suitable for lens application because of its good transparency and good elasticity.

  Increasing the amount of N-vinyl-2-pyrrolidone improves the compatibility between substances and improves transparency, but increases the water content and weakens the elasticity and tensile strength of the polymer. It was. The use of N-vinyl-2-pyrrolidone of 35 wt% or less is a polymer having a moisture content of 38% to 55%, and has good elasticity and elasticity, so that it is suitable for lens applications. is there.

(Example 7)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide and ethylene glycol dimethacrylate

  In Example 3, the water content of the polymer was adjusted to improve hydrophilicity, and in order to confirm the degree of polymerization between substances, another water-soluble monomer N, N-dimethylacrylamide was added.

Through the results obtained in Example 5, 5 wt% or less of N, N -bis (trimethylsilyl) acrylamide and 2-hydroxyethyl methacrylate are reduced in units of 90 wt% to 5 wt%, and N, N-dimethylacrylamide is reduced from 5 wt%. An ethylene glycol dimethacrylate mixed solution of 0.4 wt% crosslinker was produced while increasing in increments of 5 wt%. An initiator, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, 5 wt% of N, N -bis (trimethylsilyl) acrylamide and 40 wt% or more of N, N-dimethylacrylamide have good compatibility and can be cured to form a transparent polymer with a moisture content of 55% or more. And the expansion rate was very large. Increasing the amount of N, N-dimethylacrylamide used increased the water content and increased the expansion rate, and increased the compatibility between the substances to improve the transparency.

In this polymerization, it was found that the use of 5% or less of N, N -bis (trimethylsilyl) acrylamide is a polymer having good transparency, elasticity and water absorption, and is suitable for lens application.

  An increase in the amount of N, N-dimethylacrylamide used improves the compatibility between the substances and improves the transparency. However, an increase in the water content leads to a very large expansion coefficient, which leads to the elasticity and pulling of the polymer. The tension strength was weakened. It was found that a polymer using 40 wt% or more and 70 wt% or less of N, N-dimethylacrylamide can be applied to a lens because it has good transparency, water absorption and elasticity.

(Example 8)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide and divinylbenzene

  In Example 4, the water content of the polymer was adjusted to improve hydrophilicity, and this was carried out to confirm compatibility of the polymerization between substances and to compare the crosslinking agent of Example 7 with ethylene glycol dimethacrylate.

Through the results obtained in Example 5, 5 wt% or less of N, N -bis (trimethylsilyl) acrylamide and 2-hydroxyethyl methacrylate are reduced in units of 90 wt% to 5 wt%, and N, N-dimethylacrylamide is reduced from 5 wt%. While increasing in increments of 5 wt%, a mixed solution of 0.4 wt% crosslinker divinylbenzene was prepared. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

As a result, 5 wt% of N, N -bis (trimethylsilyl) acrylamide and 30 wt% or more of N, N-dimethylacrylamide have good compatibility, and can be cured to form a transparent polymer with a moisture content of 55% or more. And the expansion rate was very large. Increasing the amount of N, N-dimethylacrylamide used increased the water content and increased the expansion rate, and increased the compatibility between the substances to improve the transparency.

In this polymerization, it was found that the use of 5% or less of N, N -bis (trimethylsilyl) acrylamide is a polymer having good transparency, elasticity and water absorption, and is suitable for lens application.

  An increase in the amount of N, N-dimethylacrylamide used improves the compatibility between the substances and improves the transparency. However, an increase in the water content leads to a very large expansion coefficient, which leads to the elasticity and pulling of the polymer. The tension strength was weakened. It was found that it is a polymer using N, N-dimethylacrylamide of 30 wt% or more and 70 wt% or less, and it can be applied to a lens because of its transparency, water absorption, and elasticity.

  Compared to Example 7, the use of divinylbenzene over the crosslinking agent ethylene glycol dimethacrylate further improves the compatibility (transparency), but is somewhat inferior in elasticity and may reduce the diameter. all right.

Example 9
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide, N-vinyl-2-pyrrolidone and ethylene glycol dimethacrylate

  In Example 4, the water content of the polymer was adjusted to improve hydrophilicity, and the compatibility of the water-soluble monomers N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone between the monomeric substances. Went for confirmation.

Through the results obtained in Example 7, the amount of N, N -bis (trimethylsilyl) acrylamide of 5 wt% or less, 60 wt% of 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone was 40 wt%. A mixed solution of 0.4 wt% of the crosslinker ethylene glycol dimethacrylate was prepared while appropriately changing the amount of each other within a percentage. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

  As a result, despite the changes of N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone, a transparent polymer having good compatibility was produced in the cured state, but the polymer was milk while absorbing water. Changed in color.

  In this polymerization, regardless of the change of N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone, a transparent polymer having good compatibility can be produced in the cured state, but milk is hydrated while being hydrated. Since it changes to a color, it cannot be used by applying to a lens. In order to apply to a lens, either N, N-dimethylacrylamide or N-vinyl-2-pyrrolidone should be selected and used. I found out.

(Example 10)
Polymerization of N, N -bis (trimethylsilyl) acrylamide, 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone, N, N-dimethylacrylamide and divinylbenzene

  In Example 5, the moisture content of the polymer was adjusted, and the compatibility of the polymerization between the substances N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone was confirmed and compared with Example 9.

Through the results obtained in Example 8, the amount of 5 wt% or less of N, N -bis (trimethylsilyl) acrylamide, 60 wt% of 2-hydroxyethyl methacrylate, N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone was 40 wt%. A mixed solution of 0.4 wt% of the crosslinker divinylbenzene was produced while appropriately changing the amount of each other within the range of%. Initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane (0.2 wt%) was dissolved and polymerized at 110 ° C. for 30 minutes.

  As a result, despite the changes of N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone, a transparent polymer having good compatibility was produced in the cured state, but the polymer was milk while absorbing water. Changed in color.

  In this polymerization, it was found that the same result was obtained even when compared with Example 9. Regardless of changes in N, N-dimethylacrylamide and N-vinyl-2-pyrrolidone, it is possible to produce a transparent polymer that is compatible and transparent in the cured state, but it changes to milk color while being hydrated. It was found that it cannot be used by applying to lenses, and in order to apply to lenses, either N, N-dimethylacrylamide or N-vinyl-2-pyrrolidone should be selected and used. .

  It can be seen that the same results are obtained when compared with Example 9.

(Examples 11 to 16 and Comparative Example 1)
Based on the results of the above examples, in Examples 11-16, 2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, and divinylbenzene (or ethylene glycol dimethacrylate) were combined with N-vinyl-2- Pyrrolidone or N, N-dimethylacrylamide was added to produce a contact lens. As a comparative example, 2-hydroxyethyl methacrylate as a comparative example and divinylbenzene as a cross-linking agent were mixed with an initiator of 2,5-dimethyl-2,5-di Contact lenses were produced using (2-ethylhexanoylperoxy) hexane, and physical properties such as moisture content, elastic modulus, tensile strength and oxygen permeability were compared.

  The oxygen permeability is an oxygen flow rate that permeates a unit area of a material of a contact lens having a unit thickness under a condition by a unit pressure change, and its measurement method is as follows.

A. Dry the specimen and tool to be measured to the maximum.
B. After attaching the lens to the lower tool and fixing it with an O-ring, cover the upper tool and fix it with four screws so that there is no gas leakage.
C. Generate bubbles in the indicator with about 10% soapy water.
D. The gas pressure sensor is operated by connecting the gas cylinder and each part line.
E. Purge each part with the gas to be measured for about 2 hours.
F. Enter the time when the bubble in the indicator started to move and the environmental factors at that time, determine the time interval, check it, and keep it as a record.
G. Calculate using the formula.

    The above calculation formula is as follows.

  Here, P, V, and T refer to the state of the environment in which the experiment is performed, P ′ and T ′ refer to the STP state, and V ′ is a value converted to match the STP state.

  Here, l represents the average thickness of the specimen, and Pressure is substituted with a value represented by a pressure sensor. Permeability (DK) is obtained by substituting the value of equation (1) into equation (2).

  The moisture content is usually based on the dry weight basis (Dry-weight-basis) representing the weight ratio of moisture to the dry weight of the sample, but the wet weight representing the moisture content ratio as a percentage of the total weight including moisture. Standards (Wet-weight-basis) are also often used. However, many definitions related to moisture content such as 'relative moisture content at saturated moisture content' and 'equilibrium moisture content due to relative humidity of surrounding air' have come up. Recently, the ratio of the moisture volume to the total volume of the sample The volumetric water content expressed as a percentage is also used in part.

  In the case of contact lenses, the moisture content is measured using a wet weight standard.

  The measurement method is as follows.

A. Fully hydrate the lens (about 24 hours or more)
B. After removing the moisture of the sample (lens) by lightly pushing it with deer skin, the weight is measured (M ₁ ).
C. The sample is dried in the oven for a minimum of 20 minutes (when there is no further change in weight).
D. Measure the weight of the dried sample (M ₂ )
E. A minimum of 10 lenses are measured in the same manner from A to D, and the average value is taken as the moisture content.

  The calculation formula is as follows.

(Example 11: Production 1 of contact lens)
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N-vinyl-2-pyrrolidone and divinylbenzene (or ethylene glycol dimethacrylate)

64.3 wt% 2-hydroxyethyl methacrylate, 30 wt% N-vinyl-2-pyrrolidone, 5 wt% N, N -bis (trimethylsilyl) acrylamide and 0.5 wt% divinylbenzene as the cross-linking agent An initiator, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 0.2 wt% was dissolved in a mixed solution (or 0.6 wt% ethylene glycol dimethacrylate). Thereafter, it was poured into a mold made of polypropylene (Casting Mold method) and polymerized at 110 ° C. for 30 minutes to be cured. Subsequently, the lens was separated from the mold, and the compatibility state (transparency) was confirmed. As a result, it was produced transparently and hydrated to measure the water content and the state of the lens.

(Example 12: Production of contact lens 2)
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N-vinyl-2-pyrrolidone and divinylbenzene (or ethylene glycol dimethacrylate)

83.5 wt% 2-hydroxyethyl methacrylate, 15 wt% N-vinyl-2-pyrrolidone, 1 wt% N, N -bis (trimethylsilyl) acrylamide and 0.3 wt% divinylbenzene as the cross-linking agent (Or 0.4 wt% ethylene glycol dimethacrylate) using the initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane 0.2 wt% The same physical properties as in Example 11 were evaluated.

(Example 13: Production of contact lens 3)
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N-vinyl-2-pyrrolidone and divinylbenzene (or ethylene glycol dimethacrylate)

71.4 wt% 2-hydroxyethyl methacrylate, 25 wt% N-vinyl-2-pyrrolidone, 3 wt% N, N -bis (trimethylsilyl) acrylamide and 0.4 wt% divinylbenzene as the cross-linking agent (Or 0.5 wt% ethylene glycol dimethacrylate) using the initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane 0.2 wt% In the same manner as in Example 11, physical properties were evaluated.

(Example 14: Production of contact lens 4)
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N-vinyl-2-pyrrolidone and divinylbenzene (or ethylene glycol dimethacrylate)

64.3 wt% 2-hydroxyethyl methacrylate, 30 wt% N-vinyl-2-pyrrolidone, 5 wt% N, N -bis (trimethylsilyl) acrylamide and 0.5 wt% divinylbenzene as the cross-linking agent (Or 0.6 wt% ethylene glycol dimethacrylate) using the initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane 0.2 wt% In the same manner as in Example 11, physical properties were evaluated.

(Example 15: Production 5 of contact lens)
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N-vinyl-2-pyrrolidone and divinylbenzene (or ethylene glycol dimethacrylate)

65.4 wt% 2-hydroxyethyl methacrylate, 30 wt% N-vinyl-2-pyrrolidone, 4 wt% N, N -bis (trimethylsilyl) acrylamide and 0.4 wt% divinylbenzene as the cross-linking agent (Or 0.5 wt% ethylene glycol dimethacrylate) using the initiator 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane 0.2 wt% In the same manner as in Example 11, physical properties were evaluated.

Example 16 Production of Contact Lens 6
2-hydroxyethyl methacrylate, N, N -bis (trimethylsilyl) acrylamide, N, N-dimethylacrylamide and divinylbenzene (or ethylene glycol dimethacrylate)

66.4 wt% 2-hydroxyethyl methacrylate, 30 wt% N, N-dimethylacrylamide, 0.3 wt% N, N -bis (trimethylsilyl) acrylamide and 0.4 wt% divinyl as the crosslinker An initiator, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 0.2 wt% was used in a mixed solution of benzene (or 0.5 wt% ethylene glycol dimethacrylate). In the same manner as in Example 11, physical properties were evaluated.

(Comparative Example 1: Production of contact lens)
Conventionally, a mixed solution of 9 g of 2-hydroxyethyl methacrylate and 1 g of divinylbenzene as a cross-linking agent is mixed with 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane as an initiator. After 0.02 g was dissolved, it was poured into a mold made of polypropylene (Casting Mold method), polymerized at 110 ° C. for 30 minutes, and cured. Subsequently, the lens was separated from the mold and the moisture content was measured. As a result, the moisture content was 38% and the oxygen permeability was 10 to 20 Dk [10 ⁻¹¹ (cm ² / sec) mlO ₂ mmHg].

  The physical properties of contact lenses manufactured with the contents of Examples and Comparative Examples as described above are as follows.

As can be seen from Table 2 above, the examples of the present invention are hydrophilic, the moisture content is 40 to 70%, and the oxygen permeability is 50 to 90 Dk [10 ⁻¹¹ (cm ² / sec) mlO ₂ mmHg]. It is very high, and when compared with the comparative example, it can be seen that the water content and oxygen permeability are significantly higher.

Claims (7)

A soft contact lens containing 2-hydroxyethyl methacrylate and N, N-bis (trimethylsilyl) acrylamide (N, N-Bis (trimethylsilyl) acrylamide) represented by the following chemical formula (1) Monomer composition for silicone hydrogels.

Wherein one of the monomer composition, N, the content of N- bis (trimethylsilyl) acrylamide is 10 wt% or less, the monomer composition for soft contact lenses for silicone hydrogel of claim 1. The monomer composition comprises ethylene glycol dimethacrylate (Ethylene glycol dimethacrylate), a monomer composition for a soft contact lens silicone hydrogel of claim 1. The monomer composition comprises divinyl benzene (Divinyl benzen), the monomer composition for soft contact lenses for silicone hydrogel of claim 1. 4. The monomer composition according to claim 3, wherein the monomer composition includes one of N-vinyl-2-pyrrolidone and N, N-dimethylacrylamide (N, N-dimethylacrylamide). 5. Monomer composition for silicon hydrogel for soft contact lenses. 5. The monomer composition according to claim 4, wherein the monomer composition includes one of N-vinyl-2-pyrrolidone and N, N-dimethylacrylamide. 6. Monomer composition for silicon hydrogel for soft contact lenses. The soft contact lens manufactured with the said monomer composition of any one of Claims 1-6.