JPH0643465B2 - Oxygen permeable contact lens material - Google Patents

Description

TECHNICAL FIELD The present invention relates to an oxygen-permeable contact lens material useful as a material for contact lenses, for example.

[Background of the Invention]

For example, contact lenses are roughly classified into hard contact lenses containing polymethacrylic acid ester as a main component and soft contact lenses containing polyhydroxyethyl methacrylate as a main component.

The hard contact lens has advantages such as easy processing methods such as cutting and polishing, good dimensional stability, mechanical strength, transparency, etc., easy cleaning and good storage stability. Although it is widely used, the hard contact lens has a high contrast and thus causes irritation to the cornea and gives a foreign body sensation. More recently, the necessity of supplying oxygen to the cornea has been discussed, and the hard contact lens has come to be considered to have a drawback of low oxygen permeability from such a viewpoint. On the other hand, the soft contact lens swells with water to become a hydrogel, which is flexible and has a good wearing feeling and good oxygen permeability, but is poor in dimensional stability and mechanical strength. Boiled sterilization is obligatory because it is susceptible to infection, and handling is complicated.

[Conventional technology]

For the purpose of solving the above problems of contact lenses, non-hydrous oxygen-permeable contact lenses have been developed. As a material of the above-mentioned non-hydrous oxygen permeable contact lens, there has been conventionally provided a silicon-containing synthetic resin (Japanese Patent Publication No. 52-33502, Japanese Patent Publication No. 54-118455).
JP-A-55-102613 and JP-A-58-7418) and fluorine-containing synthetic resins (JP-A-56-118408, JP-A-57-51705 and JP-A-58-127914).

[Problems to be solved by the invention]

However, among the silicon-containing synthetic resins, soft ones are water-repellent and are poorly compatible with tears and adsorb to the cornea, so there is a great risk of causing damage. Poor stain resistance. On the other hand, the fluorine-containing synthetic resin has stain resistance, but is insufficient in oxygen permeability and has a brittle property, so that it is inferior in processability.

[Means for solving problems]

The present invention provides a general formula as a means for solving the above conventional problems. (In the formula, R ₁ is CH ₃ or H, n is an integer of 5 to 10, and m is 1
It is an integer of 0-20. ) Polymerizing a fluorine-containing acrylic acid ester or methacrylic acid ester represented by, a hydrophilic vinyl compound copolymerizable with the acrylic acid ester or methacrylic acid ester, and a comonomer mainly containing a polyvalent vinyl compound The present invention provides an oxygen-permeable contact lens material composed of the copolymer thus obtained.

The present invention is described in detail below.

The fluorine-containing acrylic acid ester or methacrylic acid ester used in the present invention has the general formula Wherein R ₁ is CH ₃ or H, and CnFm is n.
Is a linear or branched perfluoroalkyl group in which m is an integer of 5 to 10 and m is an integer of 10 to 20. Specific examples of the methacrylic acid ester are as follows.

The hydrophilic vinyl compound copolymerizable with the acrylic acid ester or the methacrylic acid ester is a vinyl compound having a hydrophilic group such as a carboxyl group, a hydroxyl group, an amino group or an acid amide group, and examples thereof include acrylic acid, methacrylic acid and maleic acid. , Carboxylic acid-containing vinyl compounds such as itaconic acid, crotonic acid, citraconic acid, β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, β-hydroxyethyl methacrylate,
Hydroxyl group-containing vinyl compounds such as β-hydroxypropyl methacrylate and allyl alcohol, amino group-containing vinyl compounds such as dimethylaminoethyl acrylate, dimethylaminopropyl acrylate, dimethylaminoethyl methacrylate and dimethylaminopropyl methacrylate, and acid amide groups of acrylamide and methacrylamide. Examples include vinyl compounds.

The polyvalent vinyl compound used in the present invention is a compound containing two or more vinyl groups in one molecule, and examples thereof include divinylbenzene, diallyl phthalate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate. Acrylate, neopentyl glycol diacrylate, glycerin triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Examples include propylene glycol dimethacrylate, neopentyl glycol dimethacrylate, and glycerin trimethacrylate.

In addition to the above monomers, other monomers copolymerizable with the above monomers, if desired to control hardness, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, cyclohexyl acrylate. Acrylic acid ester such as 2-ethylhexyl acrylate, methacrylic acid ester such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, cyclohexyl methacrylate and 2-ethylhexyl methacrylate, and other vinyl acetate, styrene, vinyltoluene, ethyl Vinyl ether such as vinyl ether, n-butyl vinyl ether, iso-butyl vinyl ether, acrylonitrile, methacrylonitrile and the like may be used. Furthermore, in order to improve oxygen permeability and workability, general formula (Where X and Y are C ₁ -C ₅ alkyl groups, phenyl groups, or Z groups, and Z is a general formula Is a group represented by.

A is an alkyl group or a phenyl group, R ₂ of C ₁ -C ₅ is CH ₃ or H, K is an integer of from 1 to 5, l is an integer of 1 to 3. ) The polysiloxanyl alkyl ester represented by Examples of the polysiloxanyl alkyl ester include pentamethyldisiloxanylmethyl methacrylate, heptamethyltrisiloxanylethyl acrylate, tris (trimethylsiloxy) -γ-methacryloxypropylsilane, phenyltetramethyldisiloxanylethyl. Acrylate, phenyltetraethyldisiloxanylethylmethacrylate, triphenyldimethyldisiloxanylmethylacrylate, isobutylhexamethyltrisiloxanylmethylmethacrylate, methyldi (trimethylsiloxy) -methacryloxymethylsilane, pentamethyldi (trimethylsiloxy) -acryloxy Methylsilane, t-butyltetramethyldisiloxanylethyl acrylate, n-pentylhexamethyltrisiloxanylmethylmeth Acrylate, birds -is
Examples include o-propyl tetramethyl trisiloxanyl ethyl acrylate and n-propyl octamethyl tetrasiloxanyl propyl methacrylate.

The above-mentioned fluorine-containing acrylic acid ester or methacrylic acid ester may be used alone or in combination of two or more,
Desirably, it should be contained in the copolymer in the range of 8 to 60% by weight. What is important is that the copolymer containing 8% by weight or less of the acrylic ester or methacrylic acid ester is inferior in oxygen permeability and stain resistance, and the copolymer containing 60% by weight or more becomes hard and brittle and has poor workability. Get inferior.

The above hydrophilic vinyl compounds may be used alone or in combination of two or more, and should preferably be contained in the copolymer in an amount of 3 to 10% by weight. What is more, the copolymer containing the hydrophilic vinyl compound in an amount of 3% by weight or less has poor wettability and is poorly compatible with tears, and the copolymer containing 10% by weight or more has a large water swelling property and absorbs water. It becomes inferior in shape stability at the time. Particularly desirable among the hydrophilic vinyl compounds are carboxyl group-containing vinyl compounds.

The above-mentioned polyvalent vinyl compounds may be used alone or in combination of two or more, and should preferably be contained in the copolymer in the range of 1 to 10% by weight. What is important is that the copolymer containing a polyvalent vinyl compound in an amount of 1% by weight or less does not have sufficient processability, shape stability upon absorption of water, heat resistance and chemical resistance,
The copolymer containing 0% by weight or more becomes inferior in transparency due to the poor compatibility of the fluorine-containing acrylic acid ester or methacrylic acid ester with the polyvalent vinyl compound, and the oxygen permeability becomes insufficient. .

Desirable as the other monomer copolymerizable with the above-mentioned monomer to be added in addition to the above-mentioned monomer is an acrylic acid ester or a methacrylic acid ester, and the above-mentioned acrylic acid ester or a methacrylic acid ester is one kind or two or more kinds. The acrylic or methacrylic acid ester may be used in the copolymer, preferably in an amount of 80% by weight or less to impart optical stability, dimensional stability and toughness to the copolymer. . Further, the polysiloxanyl alkyl ester is preferably contained in the copolymer in an amount of 80% by weight or less to improve the brittle property of the copolymer containing a fluorine-containing acrylic acid ester or methacrylic acid ester to improve processability. And improve oxygen permeability. On the other hand, the polysiloxanyl alkyl ester is too soft to give a polymer having poor processability, but when it is copolymerized with the above-mentioned fluorine-containing acrylic acid ester or methacrylic acid ester, it becomes hard and the processability is improved and the stain resistance is also improved. improves. Further, the fluorine-containing acrylic acid ester or methacrylic acid ester of the present invention does not impair the oxygen permeability of the polysiloxanylalkyl ester at all even when it is copolymerized with the polysiloxanylalkyl ester.

The copolymer of the present invention contains a radical initiator such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, azobisisobutyronitrile or azobisisovaleronitrile in the above-mentioned monomer mixture (comonomer).
It is produced by adding about 0.05 to 0.5% by weight and polymerizing by heating.

The bulk polymerization is carried out in a predetermined container or mold, and the copolymer is obtained in a desired shape such as a plate shape, a cylinder shape or a disk shape. In the case of processing a contact lens, it is general to further perform mechanical processing such as cutting and polishing, but it is also possible to directly perform casting polymerization in the shape of a contact lens.

The bulk polymerization is generally carried out by heat polymerization using a radical initiator as described above, but it may be carried out by irradiation with ultraviolet rays, X-rays or the like in the presence or absence of the radical initiator.

In addition to the bulk polymerization, the copolymer of the present invention is used in an organic solvent such as methanol, ethanol, iso-propanol, n-butanol, toluene, xylol, ethyl acetate, n-butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cellosolve acetate. Solution polymerization, or emulsion polymerization in which a nonionic surfactant, an anionic surfactant, or a cationic surfactant is dispersed in water for polymerization, and the like may be applied.

[Action]

The fluorine-containing acrylic acid ester or methacrylic acid ester in the copolymer of the present invention gives the copolymer good oxygen permeability and stain resistance. In addition, the hydrophilic vinyl compound imparts appropriate wettability to the copolymer and improves compatibility with tears.
Furthermore, the polyvalent vinyl compound improves the mechanical workability of the copolymer, such as cutting and polishing, by giving the copolymer a crosslinked structure, and further improving the shape stability when absorbing water, heat resistance, and chemical resistance. Let When the copolymer contains a polysiloxanyl alkyl ester, the copolymer is provided with appropriate flexibility to improve the processability and further improve the oxygen permeability. The poor stain resistance of the ester polymer is improved by the fluorine-containing acrylic ester or methacrylic ester.

[Effect of device]

Therefore, the oxygen-permeable contact lens material of the present invention has a large oxygen permeability, good processability and stain resistance, and also has good shape stability, heat resistance, and stain resistance, and is suitable as a contact lens material. When used, it has good hardness, transparency, and wettability and fits well with tears without damaging the cornea.

Example 1 The following compounds are used as the fluorine-containing methacrylic acid ester or acrylic acid ester (hereinafter referred to as monomer A).

Acrylic acid is used as the hydrophilic vinyl compound (hereinafter referred to as monomer B).

Diethylene glycol diacrylate is used as the polyvalent vinyl compound (hereinafter referred to as monomer C).

2-Ethylhexyl methacrylate is used as a monomer other than the above (hereinafter referred to as monomer D).

150 parts by weight of monomer A (hereinafter simply referred to as "part"), monomer B
12.5 parts, 6 parts of monomer C, and 100 parts of monomer D were mixed with 0.5 part of benzoyl peroxide and mixed with nitrogen gas, then sealed in a polymerization tube and oiled. Polymerization was carried out in a bath at 70 ° C. for 10 hours and 80 ° C. for 2 hours to obtain a copolymer 1.

Example 2 The following compound is used as the monomer A.

Itaconic acid is used as the monomer B.

Triethylene glycol dimethacrylate is used as the monomer C.

Methyl methacrylate is used as the monomer D ₁ .

Tris (trimethylsiloxy) -γ-as the monomer D ₂
Methacryloxypropyl silane is used.

Monomer A10 parts, B7 parts monomer, added C3 parts monomer, monomer D ₁ 30 parts of a 0.4 parts of cumene hydroperoxide in comonomer consisting of monomer D ₂ 50 parts After mixing and sealing in a polymerization tube in the same manner as in Example 1, copolymerization 2 was performed in an oil bath at 75 ° C. for 10 hours and 80 ° C. for 2 hours.

Example 3 The following compound is used as the monomer A.

Crotonic acid is used as the monomer B.

Glycerine trimethacrylate is used as the monomer C.

N-Butyl methacrylate is used as the monomer D.

Same as Example 1 by adding 0.2 parts of azobisisobutyronitrile to a comonomer consisting of 56 parts of monomer A, 5 parts of monomer B, 2 parts of monomer C and 37 parts of monomer D To obtain copolymer 3.

Example 4 A copolymer 4 is obtained in the same manner as in Example 1 except that methyl acrylate is used as the monomer D in Example 1.

Example 5 A copolymer 5 is obtained in the same manner as in Example 2 except that pentamethyldisiloxanylmethyl methacrylate is used as the monomer D ₂ of Example 2.

Comparative Example 1 Comparative polymer 1 is obtained by polymerizing n-butyl methacrylate in the same manner as in Example 1.

Comparative Example 2 Tris (trimethylsiloxy) -γ-methacryloxypropylsilane 60 parts, methyl methacrylate 30 parts,
Cumene hydroperoxide was added to a comonomer consisting of 7 parts of itaconic acid and 3 parts of ethylene glycol dimethacrylate.
Comparative Polymer 2 is obtained by adding and mixing 4 parts and polymerizing in the same manner as in Example 2.

Test the copolymer 1-5, taken out a test piece from the comparative polymer 2 oxygen permeability _{(cc (STP) · cm /} cm 2 · sec · cmHg),
The pencil hardness, cutting / polishing property, and water content / swelling property in physiological saline were measured. The oxygen permeability coefficient was measured with a Seikaken type film oxygen permeability meter (manufactured by Rika Seiki Co., Ltd.), and the pencil hardness was measured according to the JIS test method. The results are shown in Table 1.

As shown in Table 1, Comparative Polymer 1, which is a hard contact lens material, has poor oxygen permeability, insufficient hardness, and poor workability. Further, comparing Example 2 with Comparative Polymer 2, Comparative Polymer 2 containing no fluorine-containing acrylic ester or methacrylic acid ester is inferior in processability, but Example 2 is excellent in processability and has high oxygen permeability. .

Claims (2)

[Claims] 1. A general formula (In the formula, R ₁ is CH ₃ or H, n is an integer of 5 to 10, and m is an integer of 10 to 20.) 8 to 60% by weight of a fluorine-containing acrylic acid ester or methacrylic acid ester, Mainly composed of 3 to 10% by weight of a vinyl compound having a hydrophilic group copolymerizable with an acrylic ester or a methacrylic ester, and 1 to 10% by weight of a polyvalent vinyl compound containing two or more vinyl groups in one molecule. An oxygen-permeable contact lens material comprising a copolymer obtained by polymerizing a comonomer. 2. The comonomer has the general formula (In the formula, X and Y are C ₁ -C ₅ alkyl groups, phenyl groups, or Z groups, where Z is a general formula. Is a group represented by. A is a C ₁ -C ₅ alkyl group or phenyl group, and R ₂ is C
H ₃ or H, k is an integer of 1 to 5, and l is an integer of 1 to 3. The oxygen permeable contact lens material according to claim 1, wherein the polysiloxanyl alkyl ester represented by the formula (1) is mixed in an amount of 80% by weight or less.