JP2588955B2 - Soft contact lens - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a contact lens. More specifically, the present invention relates to a soft contact lens having excellent optical properties, gas permeability and mechanical properties.

[Prior Art] Contact lenses are roughly classified into hard contact lenses which usually contain substantially no water and soft contact lenses which are softened by containing water or soft without containing water.

Soft contact lenses have been used for a long time because they have a good feeling of wearing on the eyes.However, soft contact lenses with high water content have excellent permeability to gases such as oxygen because they are excellent in water content. The oxygen required for the cornea can be sufficiently supplied to the cornea from the outside air through the moisture impregnated in the lens, so that it is physiologically highly safe for the eye and is frequently used in recent years as a contact lens suitable for continuous wearing. ing. As such a highly water-containing soft contact lens, those mainly comprising polyvinylpyrrolidone are generally used.However, such contact lenses have a high water content, so that the mechanical properties at the time of water swelling are significantly reduced, Therefore, there is a drawback that it is easily broken and has poor durability.

As a contact lens material that has solved such disadvantages,
A polymer obtained by polymerizing a polyester having at least one polymerizable group in a molecule and N-vinyl lactam, has excellent durability, as well as excellent optical properties, gas permeability and mechanical properties. A hydrogel substrate has been proposed (JP-A-60-199012).

However, while such hydrogel substrates are certainly excellent in optical properties and gas permeability, contact lenses made of such hydrogel substrates do not have sufficient elongation, especially when a load is applied. There is a drawback in that it may be broken when it is slightly scratched or when it is pressed with a fingernail or the like during washing or the like.

[Problems to be Solved by the Invention] Therefore, in view of the above-mentioned prior art, the present inventors have not only excellent optical properties and gas permeability, but also excellent elongation when a load is applied. As a result of intensive research on contact lenses as much as possible, a soft contact lens satisfying all of these physical properties was found for the first time, and the present invention was completed.

[Means for Solving the Problems] That is, the present invention provides a polyester having at least one vinyl polymer group in a molecule having a number average molecular weight of 10,000 to 70,000, an N-vinyl lactam and a general formula (I): R ₁ COOCH = A vinyl monomer represented by CH ₂ (I) (wherein R ₁ represents a linear or branched alkyl group or halogenated alkyl group having 1 to 20 carbon atoms, a phenyl group or a benzyl group) The present invention relates to a soft contact lens comprising a copolymer of a contained monomer mixture.

[Action and Examples] As described above, the soft contact lens of the present invention comprises a polyester having at least one vinyl polymer group in a molecule having a number average molecular weight of 10,000 to 70,000, an N-vinyl lactam and a compound of the general formula (I): R ₁ COOCH ＝ CH ₂ (I) (wherein, R ₁ represents a linear, branched or cyclic alkyl or halogenated alkyl group having 1 to 20 carbon atoms, a phenyl group or a benzyl group) It is composed of a copolymer of a monomer mixture containing a monomer.

The soft contact lens of the present invention is made of a copolymer of the above-described monomer mixture, and in the monomer mixture, a polyester having a polymerizable group in the molecule and having excellent reinforcing ability is used. An excellent reinforcing effect can be expected as compared with the case of reinforcement, and since it has a polymer group in the polyester molecule, it can polymerize well with N-vinyl lactam and the vinyl monomer represented by the general formula (I). The copolymer obtained has an appropriate degree of elongation and, because N-vinyllactam is used, imparts water content.

As the polyester having at least one vinyl polymer group in the molecule having a number average molecular weight of 10,000 to 70,000 used in the present invention, in order to increase the rubber hardness of the obtained copolymer and to increase the strength instead of the high water content. Particularly, a grafted polyester is preferable. As such a grafted polyester, a grafted polyester of an epoxy compound and a cyclic acid anhydride shown below is preferable from the viewpoint that it has an alternating copolymerizability, so that the molecular structure and the like can be easily controlled.

The amounts of the epoxy compound and the cyclic acid anhydride are preferably approximately equimolar from the viewpoint of controlling the molecular structure by utilizing the alternating copolymerizability.

Examples of the epoxy compound include compounds selected from the group consisting of the following first to third groups. In addition, the suitable use amount is shown together with each epoxy compound.

[First group] A cyclohexene oxide represented by A styrene oxide represented by the general formula (II): Wherein R ² is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and the alkyl group may be halogen-substituted. Formula (III): (In the formula, R ³ is a group selected from the group consisting of a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms (the alkyl group may be halogen-substituted) and a phenyl group. Or two or more epoxy compounds selected from the group consisting of epoxy compounds represented by the following:

Specific examples of the compound represented by the general formula (II) or (III) include, for example, ethylene oxide, propylene oxide, 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2 -Epoxyheptane, 1,2-epoxyoctane, methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether and the like.

The amount of the epoxy compound to be used is preferably 30 to 98 mol% based on all epoxy compounds used for the reaction. When the amount is more than 98 mol%, it becomes difficult to introduce a polymer group into all polyester molecules, and when the amount is less than 30 mol%, the polymer group becomes too large and the obtained hydrogel is brittle. It tends to be.

[Second Group] General Formula (IV): (Wherein, R ⁴ is a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a formula: CH ₂ CHCH (OC ₂ H _{4 n} (where n is an integer of 2 to 50)) A group represented by CH ₂ CHCH (OC ₃ H _{6 m} (where m is an integer of 2 to 50); Formula: CH ₂ CHOCHOC _l H _21- (where 1 is an integer of 1 to 50) And an epoxy compound represented by the general formula (V): (Where k is an integer of 0 to 50) one or more epoxy compounds selected from the group consisting of epoxy compounds represented by the following formula:

Representative examples of the compound represented by the general formula (IV) include, for example, allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, vinyl poly (oxyethylene) glycidyl ether, vinyl poly (oxypropylene) glycidyl ether, and the like.

Representative examples of the compound represented by formula (V) include, for example, 3,4-epoxy-1-butene, 4,5-epoxy-1
-Pentene, 5,6-epoxy-1-hexene, 6,7-epoxy-1-heptene, 7,8-epoxy-1-octene,
Examples thereof include 8,9-epoxy-1-nonene and 9,10-epoxy-1-decene.

The amount of the epoxy compound to be used is preferably 2 to 50 mol% based on all epoxy compounds used for the reaction. When the amount is more than 50 mol%, the amount of the polymerized group to be introduced increases, and when the crosslinkable monomer is used excessively, the water content of the obtained copolymer decreases as in the case where too much crosslinkable monomer is used. If the rubber hardness tends to decrease, and if it is less than 2 mol%, it becomes impossible to introduce a polymerizable group into all the polyester molecules, and the obtained hydrogel tends to be cloudy.

[Group 3] General formula (VI): (Wherein R ⁵ is a linear, branched or cyclic alkyl group having 7 to 20 carbon atoms, and the alkyl group may be halogen-substituted);
I): (Wherein, R ⁶ is a group having 7 to 7 carbon atoms which may be halogen-substituted)
20 linear, branched or cyclic alkyl groups, phenyl groups, general formula: R ⁷ OC ₂ H _{4 a} (wherein, R ⁷ is a linear, branched or A group represented by a cyclic alkyl group (the alkyl group may be halogen-substituted) and a phenyl group, a represents an integer of 5 to 50) and a general formula: R ⁸ OC ₃ H _{6 b} (wherein, R ⁸ has 1 to 20 carbon atoms)
Selected from the group consisting of epoxy compounds represented by a linear, branched or cyclic alkyl group (the alkyl group may be halogen-substituted) or a phenyl group, and b represents an integer of 5 to 50. One or more epoxy compounds.

Representative examples of the epoxy compound represented by the general formula (VI) include, for example, 1,2-epoxynonane, 1,2-epoxyundecane, 1,2-epoxytridecane, 1,2-epoxypentadecane, 1,2 -Epoxyheptadecane, 1,2-
Epoxy octadecane and the like.

Representative examples of the epoxy compound represented by the general formula (VII) include, for example, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, and pentadecyl glycidyl. Long-chain alkyl glycidyl ethers such as ether, hexadecyl glycidyl ether, heptadecyl glycidyl ether, octadecyl glycidyl ether, nonadecyl glycidyl ether, methyl poly (oxyethylene) glycidyl ether, propyl poly (oxyethylene) glycidyl ether, pentyl poly (oxyethylene) Glycidyl ether, 2-ethylhexyl poly (oxyethylene) glycidyl ether, decyl poly ( Kishiechiren) glycidyl ether, Dodeshirupori (oxyethylene) glycidyl ether, tetradecyl poly (oxyethylene) alkyl poly (oxyethylene glycidyl ether)
Glycidyl ether and alkylpoly (oxypropylene) glycidyl ether, phenylpoly (oxyethylene) glycidylether, phenylpoly (oxypropylene) glycidylether and the like corresponding to these alkylpoly (oxyethylene) glycidylethers are exemplified.

The amount of the epoxy compound used is preferably 30 mol% or less based on all the epoxy compounds used for the reaction. If the amount used is more than 30 mol%, the molecular weight of the polyester, which is considered to be higher, is lowered, and the high molecular weight becomes difficult. As a result, the N-vinyllactam polymer cannot be sufficiently reinforced.

In order to synthesize the polyester used in the present invention, it is necessary to introduce at least one vinyl polymer group into the produced polyester molecule. For this purpose, the use of the second group of epoxy compounds is essential. If a vinyl polymer group is not introduced into the polyester molecule, phase separation occurs with poly (N-vinylpyrrolidone), and the obtained hydrogel becomes cloudy. The number of vinyl polymer groups in one molecule is preferably 20 or less, more preferably 2 to 10, because the hydrogel which is considered to be more than 20 becomes hard and brittle.

Further in the case of using C ₂ H ₄ O _n groups of containing epoxy compound such as (n represents an integer of 10 or more) in the third group, as much as possible a reduction in the water content of the obtained copolymer Suppression and elongation can be improved. In particular, the use of the third group of long-chain alkyl group-containing epoxy compounds has a remarkable effect in improving elongation.

As the cyclic acid anhydride used for the synthesis of the grafted polyester, for example, phthalic anhydride such as phthalic anhydride and tetrahydrophthalic anhydride or a derivative thereof is preferable. However, itaconic anhydride, citraconic anhydride, succinic anhydride, or maleic anhydride is not preferable from the viewpoint of obtaining a colorless and transparent hydrogel because the resulting polyester is colored.

The reaction between the epoxy compound and the cyclic acid anhydride is carried out in the presence or absence of a catalyst in a solvent or without a solvent at a reaction temperature of about 60 to 120 ° C., preferably about 70 to 90 ° C. for about 3 to several tens of hours, preferably Perform for 20-70 hours.

As a catalyst used for such a reaction, for example, Wherein R ⁹ , R ¹⁰ and R ¹¹ are the same or different and are an alkyl group having 1 to 6 carbon atoms, a benzyl group or pyridine, and the like. Basic salts of benzoic acid, lithium bromide, Al (alkoxy) ₃ , quaternary ammonium salts, quaternary phosphonium salts and the like can be mentioned. Specific examples of the basic catalyst include, for example, dimethylbenzylamine and dimethylaminopyridine, and specific examples of the quaternary ammonium salt include
For example, trimethylbenzyl ammonium chloride,
Examples of triethylbenzylammonium chloride, tetrabutylammonium bromide and the like, and specific examples of the quaternary phosphonium salt include, for example, tetra-n-butylphosphonium bromide.

The use amount of such a catalyst is preferably about 0.1 to 5 mol% based on all the cyclic anhydrides to be subjected to the reaction. If the used amount is larger than the above range, the molecular weight of the obtained polyester tends to be small. If the used amount is smaller than the above range, the reaction does not proceed efficiently and the yield of the obtained polyester is reduced.

The solvent used when the reaction is carried out in a solvent may be any solvent capable of dissolving the epoxy compound and the cyclic acid anhydride to be subjected to the reaction, such as toluene, benzene, anisole, xylene, and 1,2-dichloroethane. preferable. However, alcohols such as methanol and ethanol cannot be used because they are involved in the reaction.

In the above reaction, a polymerization inhibitor usually used, for example, hydroquinone may be used as necessary.

The polyester thus synthesized is colorless and transparent in a solution state dissolved in a solvent, is excellent in transparency, and is a white powder in a dry state. The number average molecular weight is determined by gel permeation chromatography (hereinafter referred to as GPC) (Trir
otarIII type GPC analyzer (manufactured by JASCO Corporation), detector: Shodex RI SE-31 (manufactured by Showa Denko KK), column: Sho
dex PAK GPCKF-804 (Showa Denko KK), flow rate:
When measured with 1.0 ml / min, column temperature: 40 ° C., solvent: tetrahydrofuran), it is in the range of 10,000 to 70,000. If the number average molecular weight is greater than 70,000, the viscosity of the monomer mixture increases, the operability during polymerization decreases, and 10,000
If it is smaller, the mechanical strength tends to decrease. The preferred molecular weight range is 30,000 to 60,000.

The amount of the polyester is preferably 5 to 35 parts, more preferably 10 to 35 parts, per 100 parts (parts by weight, hereinafter the same) of all monomers to be subjected to polymerization. When the amount of the polyester is less than 5 parts, the reinforcing effect is reduced. When the amount is more than 35 parts, the viscosity becomes high when mixed and dissolved in another monomer, and the operability tends to be poor.

Examples of the N-vinyllactam used in the present invention include N-vinylpyrrolidone, N-vinylpiperidone,
Examples thereof include N-vinylcaprolactam and the like, and those in which these lactam rings are substituted with one or more lower alkyl groups having 1 to 4 carbon atoms, but the present invention is limited to only these N-vinyllactams. is not. These N-vinyl lactams may be used alone or in combination of two or more.

The compounding amount of the N-vinyl lactam is preferably from 40 to 90 parts, more preferably from 50 to 80 parts, based on 100 parts of all monomers to be subjected to polymerization. When the compounding amount of such N-vinyl lactam is less than 40 parts, the water content tends to decrease and the gas permeability tends to decrease, and if it exceeds 90 parts, the hydrogel obtained becomes weak in strength. Tend.

General formula (I) used in the present invention: R ₁ COOCH ＝ CH ₂ (I) (wherein, R ₁ is a linear, branched or cyclic alkyl group or halogenated alkyl group having 1 to 20 carbon atoms, The vinyl monomer represented by phenyl group or benzyl group) is a component for imparting a desired elongation to the obtained contact lens. Specific examples of such vinyl monomers include, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate , Vinyl palmitate, vinyl stearate, vinyl monochloroacetate, vinyl benzoate, vinyl phenyl acetate and the like.

The amount of the vinyl monomer is preferably 2 to 30 parts, more preferably 5 to 20 parts, based on 100 parts of the total monomers to be subjected to the polymerization. If the compounding amount is less than 2 parts, the elongation of the obtained contact lens decreases, and if it exceeds 30 parts, machining is performed when the obtained copolymer is machined to obtain a contact lens. Properties tend to decrease.

Among the above vinyl monomers, in order to increase the elongation of the obtained contact lens, the general formula (I)
In, linear R ₁ is 7 to 20 carbon atoms, in the vinyl monomer (hereinafter, referred to as vinyl monomer A) is a branched or cyclic alkyl group or halogenated alkyl group of the general formula (I), R ₁ is It is preferable to use a vinyl monomer (hereinafter, referred to as vinyl monomer B) which is a linear or branched alkyl group having 1 to 3 carbon atoms or a branched alkyl halide group.

Specific examples of the vinyl monomer A include, for example, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, etc. Among these, vinyl laurate is a polymerizable polymer. It is preferable because it is particularly excellent in physical properties such as ease of handling and elongation applied to the polymer.

Specific examples of the vinyl monomer B include, for example, vinyl acetate, vinyl propionate, vinyl butyrate and the like. Among these, vinyl acetate is preferred because it is particularly excellent in copolymerizability, water content, transparency and the like.

When the vinyl monomer A and the vinyl monomer B are used in combination, the compounding ratio (vinyl monomer A / vinyl monomer B: weight ratio) is 1/3 to 1/1, preferably 1 / 2.5 to 1 / 1.5.
It is preferred that If the compounding ratio is larger than 1/1, the transparency of the contact lens is reduced, and 1 /
When it is smaller than 3, the processability when processing the obtained polymer into a contact lens tends to be inferior.

The vinyl monomer A and the vinyl monomer B
When vinyl monomer A and vinyl monomer B are contained in all the vinyl monomers to be copolymerized,
It is preferably adjusted so as to contain 5050% (weight%, the same applies hereinafter), especially 10 to 30%.

The copolymer used for the contact lens of the present invention,
After mixing and dissolving each monomer, it is obtained by adding a polymerization initiator and performing heat polymerization. When mixing the monomers, a solvent that does not inhibit polymerization, such as dimethylsulfoxide and dimethylformamide, is added to the polyester so that the cutting workability of the obtained copolymer is not impaired in order to uniformly dissolve the polyester. You may.

Examples of the polymerization initiator include 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) and azobisisobutyronitrile. , Peroxides such as benzoyl peroxide, t-butyl hydroperoxide and cumene hydroperoxide, and redox initiators. Of these, 2,2'-azobis ( 2,4-dimethylvaleronitrile) is particularly preferred. The amount of such a polymerization initiator is preferably from 0.001 to 2 parts, more preferably from 0.01 to 0.5 part, based on 100 parts of the total monomers used for the polymerization.

The polymerization method is not particularly limited, but is preferably performed by a temperature raising method, and is generally room temperature to 120 ° C.
It is preferable to complete the polymerization at a temperature in the range of 25 ° C., preferably 25 to 80 ° C., for several hours to several tens of hours at each temperature.

In the present invention, a molded article having a contact lens shape may be produced by subjecting the polymer obtained as described above to a cutting process, or in a mold having a shape corresponding to a predetermined contact lens. The monomer mixture may be cast and polymerized to form a contact lens molded article.

Next, the soft contact lens of the present invention will be described in more detail based on Reference Examples and Examples, but the present invention is not limited to only these examples.

Reference Example 1 [Synthesis of a polyester having a vinyl polymer group] In a four-necked round-bottomed flask in which nitrogen was substituted, 592.48 g (4.00 mol) of phthalic anhydride and cyclohexene oxide were added.
380.78 g (3.88 mol), 13.70 g allyl glycidyl ether
(0.12 mol), 400 ml of toluene as a solvent and tetra-n-butylphosphonium bromide as a polymerization initiator 2.
71 g (0.008 mol) was added and polymerized at 80 ° C. for 7 days to obtain a highly viscous liquid polymer.

Dissolve the obtained polymer in about 10 l of methylene chloride,
Then, this was gradually added into about 100 l of methanol to obtain a precipitate. After filtration, the precipitate was washed twice with about 10 l of methanol, and the obtained solid was dried under reduced pressure at 50 ° C to obtain 930 g of a white solid polyester. When the molecular weight of the polyester thus obtained was measured by GPC, the number average molecular weight (▲ ▼) was 45,000 and the weight average molecular weight (▲
▼) is 52000, dispersion coefficient (▲ ▼ / ▲ ▼) is 1.1
It was 6.

The measurement of molecular weight by GPC was performed using Trirotar III type G.
PC analyzer (manufactured by JASCO Corporation) (Detector: Shodex RI
The measurement was performed using SE-31, column: Shodex PAK GPCKF-804 (manufactured by Showa Denko KK), solvent: tetrahydrofuran, at a column temperature of 40 ° C. and a flow rate of 1.0 ml / min.
Table 1 shows the results.

Reference Examples 2 to 6 A mixed solution prepared using the compositions and component amounts shown in Table 1 was subjected to a polymerization reaction in the same manner as in Reference Example 1 under the conditions shown in Table 1. The molecular weight of the obtained polyester was measured in the same manner as in Reference Example 1. Table 1 shows the results.

Examples 1-42 and Comparative Examples 1-4 Polyester, N-vinyllactam, a vinyl monomer and a polymerization initiator shown in Table 2 were mixed at a ratio shown in Table 2 to obtain a polymerization mixture made of polypropylene having an inner diameter of 21 mm. Place in a test tube, 16 hours at 40 ° C, 8 hours at 50 ° C, then 50 hours
The temperature was raised continuously to 昇 90 ° C. over 16 hours to carry out polymerization.
The obtained polymer was taken out from a polypropylene test tube, cured at 120 ° C. for 2 hours, and then the obtained bar was cut into a lens shape, and the lens was immersed in a physiological saline solution. In addition, a soft contact lens with good strength and suppleness was obtained.

In measuring the physical properties of the obtained soft contact lens, a film-like test piece processed to be about 0.2 mm thick and about 20 mm in diameter when wet from each obtained bar was prepared. Using this, the following physical properties were measured. Table 2 shows the results.

(Appearance) The appearance of the film was visually observed in an equilibrium water-containing state.

(Water content) The water content (%) was measured according to the following equation.

(Linear swelling ratio) The linear swelling ratio (%) was measured according to the following equation.

(Punching load) Using an Instron type compression tester, apply a 1/16 inch diameter pressing needle to the center of a water-containing film (thickness: about 0.2 mm), and load the film when it breaks (g). Was measured.

(Elongation) The elongation (%) at break of the film when the punching load (g) was measured was measured.

(Strength Index) The strength index was calculated by the following equation.

(Oxygen Permeability Coefficient) Approximately 0.2 mm thick test specimen (equivalent to cutting thickness) in physiological saline at 35 ° C using a Kakenhi type film oxygen permeability meter manufactured by Rika Seiki Kogyo Co., Ltd. : 0.14 mm).

[Effects of the Invention] The soft contact lens of the present invention has a high water content, so that it has excellent oxygen permeability, can be worn on the eye for a long time, and has higher transparency and transparency than conventional water-containing soft contact lenses. Since it is excellent in mechanical strength, especially in elongation, it is hard to break and has excellent safety for eyes.

Claims (5)

(57) [Claims] 1. A polyester having a number average molecular weight of 10,000 to 70,000 and having at least one vinyl polymer group in a molecule, N-
Vinyl lactam and general formula (I): R ₁ COOCH ＝ CH ₂ (I) (wherein, R ₁ is a linear, branched or cyclic alkyl or halogenated alkyl group having 1 to 20 carbon atoms, a phenyl group) Or a benzyl group), a soft contact lens comprising a copolymer of a monomer mixture containing a vinyl monomer represented by the following formula: 2. The soft contact lens according to claim 1, wherein the polyester is a reaction product of an epoxy compound and a cyclic acid anhydride. 3. The soft contact lens according to claim 1, wherein the N-vinyl lactam is N-vinyl-2-pyrrolidone. 4. The method according to claim 1, wherein the monomer mixture has the general formula (I)
A vinyl monomer in which R ₁ is a linear, branched or cyclic alkyl group or halogenated alkyl group having 7 to 20 carbon atoms;
Soft contact lens according to claim 1, wherein R ₁ is one containing a vinyl monomer is a linear or branched alkyl group or halogenated alkyl group having 1 to 3 carbon atoms. 5. In the general formula (I), R ₁ has 7 to 20 carbon atoms.
Linear, vinyl monomer and R ₁ is a branched or cyclic alkyl group or halogenated alkyl group having 1 to 3 carbon atoms
Of a vinyl monomer that is a linear or branched alkyl group or a halogenated alkyl group in a weight ratio of 1:
The soft contact lens according to claim 4, wherein the ratio is 1 to 1: 3.