JPH0625831B2 - contact lens - Google Patents

Description

TECHNICAL FIELD The present invention relates to a contact lens having high oxygen permeability and capable of being continuously worn for a long period of time.

[Outline of Invention]

INDUSTRIAL APPLICABILITY The present invention dramatically improves the oxygen permeability of the lens and enables long-term continuous wear by using a comonomer copolymer containing fumarate as a main component in the contact lens.

[Conventional technology]

Contact lenses currently in general use are roughly classified into hard contact lenses and soft contact lenses. With regard to hard contact lenses, recently, lenses containing methyl methacrylate as a main component have been replaced by Japanese Patent Publication No.
2-35332, JP-B-56-39450, JP-B-56
A copolymer or an acrylate or methacrylate having a siloxane bond in the side chain as disclosed in -40324 and the like (hereinafter, both acrylate and methacrylate are collectively referred to as (meth) acrylate) and alkyl (meth) acrylate. Contact lenses with improved oxygen permeability have become mainstream. Soft contact lenses are hydrated and non-hydrated.
The former is, for example, 2-hydroxyethyl methacrylate or N
-A hydrophilic monomer such as vinylpyrrolidone is copolymerized with methyl methacrylate or the like, and the latter is, for example, a copolymer of butyl methacrylate and butyl acrylate.

[Problems and Objectives to be Solved by the Invention]

Each of the contact lenses has both advantages and disadvantages. That is, hard contact lenses containing polymethyl methacrylate as a main component have many advantages such as excellent vision correction effect, good durability, easy handling, and good machinability. Because of poor passage, the cornea is likely to cause physiological damage when worn for a long time. Also has a siloxane bond in the side chain (meta)
The contact lens mainly composed of acrylate and alkyl (meth) acrylate has an oxygen permeability coefficient (hereinafter referred to as Dk value) of 5 × 10 ^-11 〜 compared with PMMA of 0.5 × 10 ^-11 cm ³ · cm / cm ² sec · mmHg. Although improved to 40 × 10 ^-11 , it is still insufficient in terms of long-term wear.

Regarding hydrous soft contact lenses, the Dk value of contact lenses containing 2-hydroxyethyl methacrylate as a main component is 10 × 10 ⁻¹¹ or less, which is insufficient for long-term wear. Further, the Dk value of the contact lens containing N-vinylpyrrolidone as a main component is as high as 40 × 50 × 10 ^-11 , but the mechanical strength is weak, so the lens must be thickened, and the effective oxygen transmission amount is reduced. . Generally, hydrous soft contact lenses are prone to deposition of proteins, lipids and minerals, and bacterial growth, and daily maintenance such as boiling disinfection is difficult, and the mechanical strength when hydrous is low. Also need attention.

On the other hand, non-hydrous soft contact lenses have a Dk value of about 10
It is 30 × 10 ^-11 , and although the oxygen permeability is improved, it is still insufficient in terms of long-term continuous wear.

In general, soft contact lenses have the drawback of lacking the effect of correcting vision as compared with hard contact lenses.

That is, an object of the present invention is to provide a contact lens which can be worn continuously for a long period of time, has oxygen permeability, and is free from deposition of proteins, lipids and inorganic substances.

[Means for solving problems]

That is, the present invention is a contact lens comprising a comonomer copolymer containing the following components A and B as essential components.

A. One or more fumaric acid esters represented by the general formula [I] (R and R ′ are each independently an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, a cyclohexyl group,
Represents an alkylcyclohexyl group, a phenyl group or a benzyl group) B. One or more polyfunctional monomers selected from polyfunctional acrylates, methacrylates or allyl compounds The compound of component A used in the present invention is a diester of fumaric acid, and is an example of R and R'in the general formula [I]. Are each independently a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neo-pentyl group, 4- Examples thereof include methylpentyl group, 2-ethylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, phenyl group and benzyl group.

The polymer composed of fumaric acid ester used in the present invention is a unique rod-shaped polymer and exhibits high oxygen permeability.
This is an effect of the substituents R and R ', and the longer the side chain and the higher the bulk, the higher the oxygen permeability.
Particularly, a tertiary alkyl group such as di-t-butyl ester shows extremely high oxygen permeability.

The fumaric acid ester in the present invention can be homopolymerized, but it is necessary to copolymerize it with a small amount of a crosslinking component in consideration of the mechanical strength, machinability and thermal stability of the polymer. . The crosslinking component is a polyfunctional polymerizable monomer, and the polyfunctional acrylate, methacrylate or allyl compound of the component B is used. Specific examples include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, allyl (meth) acrylate, diallyl phthalate, diallyl isophthalate. , Diallyl terephthalate, diethylene glycol bisallyl carbonate, triallyl isocyanurate and the like.

Further, in the present invention, the fumaric acid ester and the polyfunctional acrylate, methacrylate or allyl compound having a crosslinkability are characteristically used, but the processability, flexibility and lens For the purpose of improving the feeling of wearing and the like, copolymerization in a system to which other general vinyl monomers are added is also possible. Vinyl monomers in this case include styrene, P-methylstyrene, vinyl acetate, vinyl propionate, ethyl vinyl ether, butyl vinyl ether, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, (meth). ) Acrylic amide, etc. can be raised.

In order to copolymerize the above monomer system, various commonly used radical polymerization initiators are used,
It is determined in consideration of the polymerization behavior of the monomer. Copolymerization of this monomer system to form a contact lens can be carried out by a commonly used method. Copolymerization of a comonomer containing a polymerization initiator in an appropriate container such as a tester to obtain a round bar or block, cutting,
A lens suitable for the prescription may be processed by mechanical processing such as polishing. Further, it is also possible to directly mold a contact lens by injecting a comonomer containing a polymerization initiator into a space formed by two molds and performing mold polymerization. When polymerizing a large volume, distortion is likely to occur inside, so it is rational to use water as the heat medium in order to control the reaction and obtain a uniform material.

It is also possible to polymerize by adding a coloring material such as a dye or an additive such as an ultraviolet absorbing agent to the above monomer system.

Further, it is effective to increase the hydrophilicity of the lens surface and improve the feeling of wearing by chemically treating the finished lens surface with acid or alkali, or by subjecting it to low temperature plasma treatment.

[Action]

The polymer containing fumarate as a main component is a polymer having low polarizability since the repeating unit is alkoxycarbonylmethylene, and is expected to exhibit high oxygen permeability due to the bulky substituent. In addition, since the surface energy of the material is small and it is hydrophobic, it can prevent the deposition of proteins, lipids and inorganic substances on the surface, and it also prevents the permeation of water into the lens, so that the proteins, lipids and It is considered that the penetration of the inorganic material into the lens can be prevented, and the growth of mold and bacteria inside the material can be prevented.

〔Example〕

Hereinafter, the present invention will be described in detail based on Examples.
The present invention is not limited to these ranges.

Example 1 98 parts by weight of di-t-butyl fumarate and 2 parts by weight of diethylene glycol dimethacrylate were mixed well at 60 ° C., 1 part by weight of azobisisobutyronitrile (AIBN) was added, and the mixture was stirred to make uniform. This mixed solution was poured into a glass test tube, the inside was replaced with nitrogen, and then the tube was sealed. This test tube is immersed in a warm water bath whose temperature is controlled by a program controller, and the temperature is 65 ° C for 6 hours, 67 ° C for 3 hours, and 70 ° C.
Polymerization for 3 hours, 75 ° C. for 3 hours, 80 ° C. for 3 hours, 85 ° C. for 2 hours, and 90 ° C. for 2 hours to carry out polymerization. A round bar of the obtained copolymer was cut, cut and polished to obtain a contact lens.

MODEL manufactured by Xertex Corporation for measurement of oxygen transmission coefficient
2110 (Multi-range Analyzer for Dissolved Oxyge
n) was used to measure a test piece having a diameter of 12.7 mm and a thickness of 0.2 mm in a 0.9% physiological saline solution at 35 ° C. As a result, the oxygen permeability coefficient was 10.2 × 10 ^-11 [cm ³
(STP) · cm / cm ² · sec · mmHg].

The bending strength was measured according to ASTM D790, and the result was 15.2 [kg / mm ² ].

The stain adhesion was determined by immersing a flat plate-shaped test piece having a diameter of 12.7 mm and a thickness of 0.2 mm in a 0.2% egg white lysozyme aqueous solution at 37 ° C. for 24 hours, and measuring the absorbance of light at 280 nm.
The amount of adhesion was determined. As a result, the adhesion of egg white lysozyme
It was not recognized.

Example-2 94 parts by weight of di-t-butyl fumarate, 5 parts by weight of vinyl acetate, and 1 part by weight of diethylene glycol dimethacrylate were mixed well at 60 ° C., and 1 part by weight of AIBN was added and stirred to homogenize. The polymerization method, contact lens molding method, and test method were the same as in Example-1.

Oxygen permeability coefficient is 5.3 × 10 ^-10 [cm ³ (STP) ・ cm / cm ²・ se
c · mmHg] and bending strength was 7.8 [kg / mm ² ]. No adhesion of egg white lysozyme was observed.

〔effect〕

As described above, the present invention is a contact lens composed of a comonomer copolymer containing fumarate as a main component and having high oxygen permeability. In addition, its value is superior to the (meth) acrylate-based lens having a siloxane bond that is currently used as a highly oxygen permeable lens, and it can supply sufficient oxygen to the cornea, so that it can be worn continuously for a long period of time. Is. Furthermore, the contact lens of the present invention is non-hydrous, does not cause bacterial growth, and is less likely to deposit protein, lipid, or inorganic matter, so maintenance is easy, and from this aspect, continuous wear is also possible. It is a great contribution.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruhiro Ikebe 32-16 Higashiarai, Yatabe-cho, Tsukuba-gun, Ibaraki Open 101 101 (72) Inventor Takayuki Otsu 13444-1-3, Midorigaoka, Nara City, Nara Prefecture

Claims (1)

[Claims] 1. A contact lens comprising a comonomer copolymer containing components A and B as essential components. A. One or more fumaric acid esters represented by the general formula [I] (R and R ′ are each independently an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms, a cyclohexyl group,
Represents an alkylcyclohexyl group, a phenyl group or a benzyl group. ) B. One or more polyfunctional monomers selected from polyfunctional acrylates, methacrylates or allyl compounds.