JPH10221651A - Contact lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact which has a high oxygen permeability coefft., is light in weight suitable for lacrimal fluid exchange and has a good feel of use. SOLUTION: This contact lens is formed by using 20 to 70 pts.wt. radical polymerizable silicon based monofunctional monomer contg. 10 to 30% silicon atoms and having one (meth)acrylic group as a functional group in the molecule as a first component, 1 to 10 pts.wt. di(meth)acrylate having an urethane bond as a second component, 10 to 70 pts.wt. alkylene styrene and 1 to 40wt.% monomer copolymerizable with these monomers as a third component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a contact lens. More specifically, the oxygen permeability coefficient is high,
The present invention relates to a contact lens which is suitable for tear exchange and is lightweight and has a good wearing feeling.

[0002]

2. Description of the Related Art Contact lenses currently on the market are roughly classified into two types, soft contact lenses and hard contact lenses, based on their properties.

[0003] In a soft contact lens, a hydrophilic polymer mainly composed of 2-hydroxyethyl methacrylate, which is a hydrophilic monomer, or a soft hydrophobic polymer such as silicone rubber is used.

[0004] Hard materials such as polymethyl methacrylate are used for hard contact lenses.

[0005] Of these, hard contact lenses are widely used because they are easier to handle than soft contact lenses and have excellent visual acuity correcting effects. However, a hard contact lens using polymethyl methacrylate or the like is inferior to a soft contact lens in wearing feeling, and has a small burden on the cornea due to a small amount of oxygen permeation.

Therefore, as a hard contact lens with further improved wearing feeling, an oxygen-permeable hard contact lens containing (meth) acrylate having a siloxane bond as a main component or a fluorine-containing (meth) acrylate is used as a hard contact lens. Many lenses with improved contamination have been developed.

[0007] Although the above-mentioned hard contact lenses do improve the feeling of wearing, the tear exchange ability, which is one of the major factors for improving the feeling of wearing, has hardly been studied. It is desirable that the cornea be constantly immersed in fresh tears by exchanging tears, and that the material be easily supplied with atmospheric oxygen.

According to Japanese Patent Application Laid-Open No. 57-209915, an oxygen-permeable molded article characterized by containing a bifunctional siloxane monomer as a main component has been proposed. Although this molded article has a certain degree of oxygen permeability, it has a drawback that bridging progresses and the brittleness cannot be obtained because the siloxane monomer as a main component is bifunctional, so that sufficient strength cannot be obtained. It is desired to develop a contact lens material having high strength.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a contact having a high oxygen permeability coefficient and high mechanical strength, a light weight suitable for tear exchange, a good wearing feeling, and a surface modification of a lens suitable for wearing. A lens is provided.

It is of the utmost importance that the supply of oxygen from the atmosphere to the cornea should not be impaired in the wearing of contact lenses, and in recent years, materials for highly oxygen-permeable contact lenses have been actively developed. I have.

However, it is difficult to supply sufficient oxygen to the cornea simply by improving the oxygen permeability of the material itself. In order to provide sufficient oxygen to the cornea, a contact lens material that facilitates the supply of tears containing fresh oxygen is required. The contact lens on the cornea is pulled up by the upper eyelid together with the blink, and at that time, tears penetrate under the contact lens, and the contact lens is sucked to the cornea again as the eyelid opens and falls downward. At this time, excess tears under the contact lens are discharged outside. The blinks cause the contact lens to act like a pump to let tears in and out, supplying fresh oxygen.

The present invention provides a contact lens material having a low specific gravity, which facilitates the above-described pump action more easily, and provides a contact lens which can always supply fresh tears and oxygen.

[0013]

SUMMARY OF THE INVENTION The present invention provides a radically polymerizable silicon-based monofunctional monomer having a silicon atom content of 10 to 30% as a first component and one (meth) acryl group as a functional group in a molecule. 20 to 70 parts by weight of a monomer, 1 to 10 parts by weight of a di (meth) acrylate having a urethane bond as a second component, 10 to 70 parts by weight of an alkylstyrene as a third component, and copolymerizable with these monomers From 1 to 40 parts by weight of a suitable monomer.

The contact lens of the present invention has a high oxygen permeability coefficient, is lightweight and suitable for tear exchange, and has a good wearing feeling.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a material suitable for tear exchange because of its high oxygen permeability coefficient and light weight. In the present invention, a radically polymerizable silicon-based monomer having a high silicon atom content as an essential material is used as a material having a high oxygen permeability coefficient.

In general, it is known that a resin made of a monomer having a high silicon atom content has a high oxygen permeability.
In the present invention, the oxygen permeability coefficient is 40 or more, more preferably 6 or more.
Desirably, it is 0 or more. Therefore, in the present invention, (meth) is used as a functional group having a silicon atom content of 10 to 30%.
A radically polymerizable silicon-based monomer having one acryl group in a molecule is used.

The silicon monomer as the first component used in the present invention is monofunctional. As a specific example of the silicon monomer used in the present invention, pentamethyldisiloxanylmethyl (meth ) Acrylate, pentamethyldisiloxanylpropyl (meth) acrylate, tris (trimethylsiloxy) silylpropyl (meth) acrylate, methylbis (trimethylsiloxy) silylpropyl (meth) acrylate, isobutylhexamethyltrisiloxanylmethyl (meth) Acrylate, trimethylsilylmethyl (meth) acrylate, trimethylsilylpropyl (meth) acrylate, tris (trimethylsiloxy) silylpropylglycerol (meth) acrylate, methylbis (trimethylsiloxy) silylpropylglycerol (meth) Acrylate and the like.

The larger the amount of the silicon-based monomer used, the larger the oxygen permeability coefficient. However, since the hardness and heat resistance sufficient to withstand cutting and working and the specific gravity are unlikely to be low, in the present invention, 20 to 70 parts by weight, preferably 30 to 6
Used at 0 parts by weight. If the amount is less than 20 parts by weight, it is difficult to obtain a material having a large oxygen permeability coefficient. On the other hand, if it exceeds 70 parts by weight, sufficient strength cannot be obtained, and a material having a low specific gravity suitable for tear exchange, which is an effect of the present invention, cannot be obtained.

Next, a di (meth) acrylate having a urethane bond is an essential component as a second component of the present invention in order to improve the oxygen permeability coefficient and mechanical strength. As the di (meth) acrylate having a urethane bond, a radically polymerizable silicon-containing di (meth) acrylate having a urethane bond is preferable. For example, the following general formula (1)
Are shown. General formula (I):

[0020]

Embedded image (Wherein, R ¹ and R ² each represent a hydrogen atom or a methyl group, m, n and x each represent an integer of 1 to 10, and R ³ represents a general formula (II), (III) or (IV), respectively)

[0021]

Embedded image A siloxane skeleton represented by R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
R ⁸ and R ⁹ represent an alkylene or ether group having 2 to 40 carbon atoms, and p, q and r represent an integer of 1 to 40. ) And a radical-polymerizable silicon-containing di (meth) acrylate having a urethane bond.

As the amount of the radical-polymerizable silicon-containing di (meth) acrylate having a urethane bond increases, the flexibility and mechanical strength increase and the oxygen permeability coefficient improves. It is hard to be specific gravity,
In addition, in the present invention, it is used in an amount of 1 to 10 parts by weight because the compatibility is deteriorated.

Next, a third component represented by the general formula (V):

[0024]

Embedded image (The alkyl group of the formula R is C _{n: n} = 1~6) alkylstyrene represented by is used as an essential component.

The present invention is characterized in that an alkylstyrene represented by the general formula (V) is used. By using this, a contact lens having a low specific gravity and a high refractive index suitable for tear exchange can be obtained. Obtainable. The specific gravity is desirably 0.90 to 1.05. Alkylstyrene is preferable because the homopolymer itself has some oxygen permeability. Examples of the alkyl styrene used in the present invention include methyl styrene, ethyl styrene, propyl styrene, isopropyl styrene, normal butyl styrene, tertiary butyl styrene, pentyl styrene, hexyl styrene, and the like. It is 10 to 70 parts by weight, preferably about 30 to 100 parts by weight.
60 parts by weight.

Further, although C _n of R in the general formula (V) is larger weight, the resin after polymerization as increases becomes brittle, it is desirable to adjust the number of n if needed.

In the present invention, as a fourth component, a hydroxyl group-containing alkyl (meth) is used to impart hydrophilicity to the obtained contact lens, and to additionally enable hydrophilic treatment by coupling reaction with silanol. Acrylates can be used as the polymerization component. Specific examples of the hydroxy-containing alkyl (meth) acrylate used in the present invention include hydroxyethyl (meth) acrylate,
Examples include hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, and dipropylene glycol mono (meth) acrylate. . When the amount of these hydroxyl group-containing alkyl (meth) acrylates is extremely small, sufficient hydrophilicity or a hydroxyl group required for a coupling reaction with silanol cannot be obtained. It cannot be a material with a low specific gravity suitable for tear exchange, which is an effect. Therefore, the amount of the hydroxyl group-containing alkyl (meth) acrylate is preferably 1 to 10 parts by weight, more preferably about 3 parts by weight, per 100 parts by weight of the copolymer component.
８8 parts by weight.

Further, other copolymer components other than those described above include:
Examples thereof include an alkyl (meth) acrylate and a fluoroalkyl (meth) acrylate, and it is desirable to select the type according to the properties required for a target contact lens. In particular, in order to prepare a low specific gravity contact lens suitable for tear exchange, the alkyl (meth) acrylate and the fluoroalkyl (meth) acrylate are desirably about 0 to 10 parts by weight.

In order to improve the processability, the strength of the material, etc., as a crosslinking agent, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate
Acrylate, tetraethylene glycol di (meth) acrylate, ethyl glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) Various methacryls such as acrylate and dipentaerythritol hexa (meth) acrylate, acryl, divinylbenzene, trivinylbenzene and the like can be used. However, in order not to impair the oxygen permeability of the material and the light weight, which is an effect of the present invention, it is preferable to use 10 parts by weight or less.

Further, it can be used in an amount of 10 parts by weight or less for the purpose of imparting a certain degree of hardness and flexibility, improving the transparency of the resin, and improving the fixation of a dye for a color lens. Examples of these monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, and hexyl (meth) acrylate.
Acrylate, cyclohexyl (meth) acrylate,
Linear, branched or cyclic alkyl acrylates such as heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and the like. It is desirable to select according to.

The copolymerization in the present invention can be carried out by ordinary radical polymerization. As a radical polymerization initiator, for example, 2,2'-azobisisobutyronitrile, 1,1
1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4
-Dimethylvaleronitrile), azo compounds represented by dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis (2,4,4-trimethylpentane), bezoyl peroxide, lauroyl peroxide, stearoyl peroxide Oxide, bis (4-tert-butylcyclohexyl) peroxydicarbonate, α, α-bis (tert-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-
A peroxide represented by 2,5-bis (tert-butylperoxy) hexane can be used.

The polymerization can be carried out by injecting a monomer containing a polymerization initiator into a mold which has been prepared in the form of a contact lens in advance, or by carrying out the polymerization in a tubular mold. A method of cutting and polishing contact lenses is also possible. In addition, heat polymerization is generally used for polymerization, but a polymerization method using ultraviolet light or γ-ray irradiation is also within the scope of the present invention.

Further, it is possible to dye the contact lens obtained by the present invention with a dye later, and to perform ultraviolet irradiation, ozone irradiation, oxygen plasma irradiation or the like to impart wettability to the surface. Furthermore, it is also within the scope of the present invention to bond various hydrophilic groups to the surface.

Next, embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

(Examples 1 to 3)

[0036]

Embedded image 4-ethylstyrene (4-Et-St), tris (trimethylsiloxy) -γ-methacryloyloxypropylsilane (SiMA) represented by the formula:

[0037]

Embedded image Silicon-containing urethane acrylate (U
A), ethylene glycol dimethacrylate (ED),
And 2-hydroxyethyl methacrylate (HEMA)
Was adjusted as shown in Table 1.

After sufficiently stirring the above components so as to be uniform, the mixture is poured into a polypropylene test tube having an inner diameter of 15 mm and a depth of 300 mm.
Is heated in 30 minutes, kept at 50 ° C. for 15 hours, and then heated to 75 ° C.
The temperature was raised over 8 hours until the polymerization. After completion of the polymerization, the mixture was transferred to a drier and dried at 90 ° C. overnight, and then released from a polypropylene test tube.
After immersion for an hour, it was dried overnight in a vacuum dryer at 117 ° C. to obtain a rod-shaped polymer. The obtained polymer was cut into a predetermined thickness and further polished to obtain a sample for evaluating physical properties.

The specific gravity, Vickers hardness (Hv), oxygen permeability coefficient (Dk), Vickert softening point and strength were evaluated. Table 2 shows the evaluation results. The evaluation method is as follows.

Evaluation method Specific gravity: Measured at 36 ° C. using an automatic specific gravity measuring device SGM-6 manufactured by METTLER TOLEDO.

Vickers hardness (Hv) The polished sample was measured using a micro hardness meter MVK-EIII manufactured by Akashi Seisakusho.

Oxygen permeability coefficient (Dk) (10 ⁻¹¹ cm ³ )
cm / sec · cm ² · mmHg) The polished sample was measured at 36 ° C. using OX-TRAN 100A manufactured by MOCON.

The polished sample was measured using a heat resistant deformation tester manufactured by Ueshima Seisakusho.

Strength The obtained polymer was cut and polished to obtain a contact lens, which was inverted. At that time, a lens that did not break was evaluated as ○, and a broken lens was evaluated as ×, and the strength was evaluated.

[0045]

[0046]

(Examples 4 to 6) In Examples 1 to 3,
It adjusted so that it might become a composition as shown in Table 3 using 4-tert-butyl styrene (4-tBu-St) without using 4-ethylstyrene, and carried out similarly to Examples 1-3. Was obtained, cut to a predetermined thickness, and further polished to prepare a sample for evaluating physical properties. This physical property evaluation sample was evaluated in the same manner as in Examples 1 to 3. Table 4 shows the evaluation results.
Shown in

[0048]

[0049]

From the physical properties shown in Tables 2 and 4, Examples 1 to 6 are excellent in having a low specific gravity suitable for tear exchange, a high oxygen permeability coefficient and a high mechanical strength, and a strength that can withstand cutting and processing. It turns out to be something.

In particular, the contact lens materials of Examples 4 to 6 have a low specific gravity suitable for tear exchange, and the larger the carbon number of R in the general formula (V), the lighter the weight. It is understood that it is preferable as a contact lens material suitable for the above. However, if the size is too large, the resin becomes brittle, so that the carbon number is preferably about 4.

(Comparative Examples 1-4) In Examples 1-6,
Without using silicon-containing urethane acrylate (UA),
Furthermore, monofunctional tris (trimethylsiloxy) -γ
-The composition shown in Table 5 is obtained by using bifunctional 1,3-bis (4-methacryloxybutyl) tetradimethylsiloxane (Bis-SiMA) without using methacrooxypropylsilane (SiMA). And a copolymer was obtained in the same manner as in Examples 1 to 6, cut to a predetermined thickness, and further polished to prepare a sample for evaluating physical properties. This physical property evaluation sample was evaluated in the same manner as in Examples 1 to 6. Table 6 shows the evaluation results.

[0053]

[0054]

As shown in Table 6, even if the crosslinking effect is improved by using a bifunctional silicon-based monomer without using a silicon-containing urethane acrylate (UA), the lens is broken when the lens is inverted, and the urethane is removed. Sufficient strength was not obtained compared to when acrylate was compounded. Further, the oxygen permeability coefficient is 30 or less, which is unsuitable as a contact lens material that does not burden the cornea.

(Examples 7 to 9) The test pieces prepared in Examples 4 to 6 were processed into contact lenses, and subjected to a hydrophilic treatment by a silanol treatment. The pH is adjusted to 4.5 to 5 with acetic acid.
A polyethylene oxide group-containing silane compound (Shin-Etsu Chemical X-12-
641) was added with stirring so that the final concentration was 2%. After holding for 5 minutes to produce silanol, the contact lens was immersed in the solution for 2 minutes. Two minutes later, the contact lens was taken out of the solution, washed lightly with ethanol, and cured at 80 ° C. for 30 minutes to obtain a hydrophilically treated contact lens. The contact angle of the obtained contact lens was evaluated. Table 7 shows the evaluation results. The evaluation method is as follows.

Contact angle CONTACT-ANGLE METE manufactured by Kyowa Interface Chemistry
Using R, the contact angle of the polished sample was measured by a liquid method.

[0058]

As shown in Table 7, the contact angle is reduced by the silanol treatment, and the contact lens can be treated with good wettability.

[0060]

The contact lens of the present invention is light in weight suitable for tear exchange. In addition, since a monomer containing an aromatic is used, the refractive index is high, and since urethane acrylate is used, oxygen permeability and mechanical strength are high. Further, since a hydrophilic treatment for enhancing a feeling of wearing can be easily performed, it is suitable as a hard contact lens.

Claims (4)

[Claims] 1. A method according to claim 1, wherein the first component has a silicon atom content of 1
20 to 70 parts by weight of a radical polymerizable silicon-based monofunctional monomer having one (meth) acryl group in the molecule as a functional group at 0 to 30%, and di (meth) acrylate having a urethane bond as a second component A contact lens obtained by copolymerizing 1 to 10 parts by weight, 10 to 70 parts by weight of an alkylstyrene as a third component, and 1 to 40 parts by weight of a monomer copolymerizable with these monomers. 2. The specific gravity at 36 ° C. is 0.90 to 1.0.
5. The contact lens according to claim 1, wherein the oxygen permeability coefficient is 5 or more. 3. The contact lens according to claim 1, wherein the di (meth) acrylate having a urethane bond has a silicon atom. 4. The contact lens according to claim 1, wherein 1 to 10 parts by weight or less of an alkyl (meth) acrylate having a hydroxyl group is copolymerized as a fourth component.