JPH06123861A - Hydrous contact lens - Google Patents

Abstract

PURPOSE:To provide a soft contact lens ensuring good wearing feeling and having a high water content and high strength. CONSTITUTION:This hydrous contact lens consists of 2-50 pts.wt. diacrylic (methacrylic) ester represented by formula I or II, 20-90 pts.wt. vinylpyrrolidone or 2-hydroxyethyl methacrylate and 8-50 pts.wt. monomer copolymerizable with them and has >=50% water content and high bending strength. In the formulae I, II, X is H or CH3 and (n) is an integer of 6-25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrous contact lens. More specifically, the water content is 5
The present invention relates to a hydrous contact lens having a high bending strength of 0% or more.

[0002]

2. Description of the Related Art It is needless to say that a contact lens is mainly intended to correct visual acuity, but since it is inserted into the inside of the eye, comfort is particularly required. From this point of view, it is generally said that the soft contact lens has a better wearing feeling to the human eye than the hard contact lens. The reason for this is that, in general, soft contact lenses are worn in a water-containing state, so that they do not give a strange feeling to the eyeball. In fact, it is said that a soft contact lens having a high water content has a better wearing feeling.
However, a soft contact lens having a high water content generally has low strength and is immersed in water for a long time, or conversely, dried, or when the lens is handled,
It was easy to cause cracks and deformation, and various problems were always caused by the low strength. From this point of view, the appearance of a soft contact lens having a high water content and high strength is desired.

[0003]

A problem to be solved is to obtain a soft contact lens which has a high water content with a good feeling of wearing and a high strength.

[0004]

In the present invention, as a solution to this problem, a water-soluble vinylpyrrolidone-based monomer is used as a main raw material and has a radical copolymerizability therewith and is a water-soluble long-chain cross-linking agent. A soft contact lens having a high water content and a high strength by forming a water-containing crosslinked product of a difunctional (meth) acrylate represented by the following structural formula 1 or structural formula 2 which is an agent. Is what you are trying to get.

The present invention will be described in detail below. As a raw material for soft contact lenses, conventionally, water-soluble 2-hydroxyethyl methacrylate, vinylpyrrolidone, acrylamide and the like have been obtained by copolymerization with a crosslinking agent. However, the cross-linking agent used here has few hydrophilic materials, and if the cross-linking agent is used in a large amount in order to increase the strength of the lens, the water content lowers at present. Some materials such as diacrylamide, which are extremely hydrophilic, are also known, but they are questioned for safety as contact lenses. As described above, at present, there is a contradiction between increasing the water content of the contact lens and the amount of the crosslinking agent used for increasing the strength. This is due to the fact that no hydrophilic long-chain cross-linking agent has been found.

The present invention provides the following chemical formula 3 (structural formula 1) or
By using a diacrylic (methacrylic) ester represented by the following chemical formula 4 (Structural Formula 2) as a cross-linking agent, this problem is solved, and a soft contact having a high water content with a good wearing feeling and a high strength. I got a lens.

[0007]

[Chemical 3]

[Chemical 4]

The monomer represented by Structural Formula 1 or Structural Formula 2 has two acrylic (methacryl) groups which are radically polymerizable functional groups, and can be three-dimensionally crosslinked. Furthermore, since it has a large number of extremely hydrophilic ethylene oxide units or propylene oxide units, it is possible to use the monomer itself as an extremely hydrophilic material.

The greatest feature of the present invention is that the diacrylic (methacrylic) ester represented by Structural Formula 1 or Structural Formula 2 is used as a cross-linking agent.
Alternatively, the value of n in Structural Formula 2 is extremely important. That is, the hydrophilicity of the diacryl (methacrylic) ester represented by Structural Formula 1 or Structural Formula 2 greatly changes depending on the value of n. In the present invention, the value of n in Structural Formula 1 or Structural Formula 2 is usually an integer in the range of 6 to 25, although it depends on the desired water content. If the value of n is less than 6, it is difficult to make a material having a water content of 50% or more specified by the present invention and having strength. Conversely, 2
When it exceeds 5, the hydrophilicity increases, but the cross-linking effect decreases, and the strength, especially the bending strength when containing water, becomes weak. From this point of view, in the present invention, the value of n in Structural Formula 1 or Structural Formula 2 is generally preferably an integer in the range of 6 to 25.

Next, the contact lens according to the present invention includes vinylpyrrolidone or 2 in addition to the diacrylic (methacryl) ester represented by Structural Formula 1 or Structural Formula 2.
-Hydroxyethyl methacrylate is used as the main component. These compounds are useful monomers having excellent hydrophilicity and radical polymerizability.

In the present invention, the diacryl (methacryl) ester and vinylpyrrolidone of Structural Formula 1 or Structural Formula 2 or 2-hydroxyethyl methacrylate are 2 to 50 parts by weight of diacryl (methacryl) ester, and vinylpyrrolidone, 20-90 parts by weight of 2-hydroxyethyl methacrylate is used as the main composition of contact lenses. Diacrylic (methacrylic)
If the amount of the ester is less than 2 parts by weight, the crosslinking effect is weak and a strong lens cannot be obtained. If it is used in excess of 50 parts by weight, crosslinking will proceed too much, and the lens will become brittle, and
The water content also does not increase. If the amount of vinylpyrrolidone or 2-hydroxyethyl methacrylate is less than 20 parts by weight, it has no hydrophilicity and the water content does not increase. If it exceeds 90 parts by weight, the water content increases,
Crosslinking does not become large, and a strong lens cannot be obtained. From this, in the present invention, the diacryl (methacryl) ester and the vinylpyrrolidone of Structural Formula 1 or Structural Formula 2 or 2-hydroxyethyl methacrylate are the diacryl (methacryl) ester 2 to 50.
A good range is 20 parts by weight and 20 to 90 parts by weight of vinylpyrrolidone and 2-hydroxyethyl methacrylate.

Next, in the present invention, in addition to these diacryl (methacryl) ester and vinylpyrrolidone of the structural formula 1 or structural formula 2, or 2-hydroxyethyl methacrylate, the gist of the present invention is not impaired. Then, the monomer copolymerizable with these can be used in the range of 8 to 50 parts by weight. The purpose is to add various characteristics to the contact lens and the manufacturing method thereof. For example, the water content is moderate, the bending strength is adjusted, the polymerization rate is adjusted, the workability such as grinding and polishing of contact lenses is improved, the curve design is facilitated, the refractive index Is to adjust the.

Specific examples of the monomers used for these purposes are methyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate,
2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, phenyl acrylate, phenoxyethyl acrylate, ethylene glycol diacrylate (methacrylate), propylene glycol diacrylate (methacrylate), 1,4-butanediol diacrylate (methacrylate), 1,6-hexane Diol diacrylate (methacrylate), neopentyl glycol diacrylate (methacrylate), 1, 9-
Nonanediol diacrylate (methacrylate),
1,10-decanediol diacrylate (methacrylate), diethylene glycol diacrylate (methacrylate), triethylene glycol diacrylate (methacrylate), tetraethylene glycol diacrylate (methacrylate), bisphenol A diacrylate (methacrylate), 2,2 bis ( 4-acryloxyethoxyphenyl) propane, 2,2 bis (4-
Acryloxydiethoxyphenyl) propane, 2,2bis (4-acryloxytriethoxyphenyl) propane, 2,2bis (4-acryloxytetraethoxyphenyl) propane, 2,2bis (4-methacryloxyethoxyphenyl) Propane, 2,2bis (4-methacryloxydiethoxyphenyl) propane, 2,2bis (4-
Examples thereof include various monofunctional and polyfunctional acrylates (methacrylates) such as methacryloxytriethoxyphenyl) propane, glycerin triacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate. Furthermore, monomers having a vinyl group such as styrene, α-methylstyrene, chlorostyrene and divinylbenzene can be effectively used. These are just examples and the present invention is not limited thereto.

Next, the diacryl (methacrylic) ester represented by the structural formula 1 or 2 and vinylpyrrolidone or 2-hydroxyethyl methacrylate and the monomer copolymerizable therewith are mixed and copolymerized. . At this time, a polymerization initiator is used, but in the present invention,
There is no particular limitation, and a usual radical polymerization initiator can be used. The monomer mixture, to which an appropriate amount of radical polymerization initiator is added, is poured into a polymerization mold made of metal, glass, plastic or the like having a designed curvature and heat-cured to give a copolymer resin or , The lens is obtained. The heat curing temperature is 30 to 10 in the present invention.
Although about 0 ° C. is adopted, it may be changed depending on the purpose. Further, in the present invention, it is needless to say that various additives such as an ultraviolet absorber can be added to the monomer according to the purpose, and it is more effective. The copolymer resin obtained in the present invention can be used as a contact lens by being hydrated as it is. However, in many cases, after this, a conventional means is used for the contact lens intended for the copolymer resin. Then, the soft contact lens can be obtained by performing grinding and polishing. Hereinafter, the present invention will be described with reference to examples.

Example (1) 15 parts by weight of dimethacrylic ester represented by the following chemical formula 5 (structural formula 3) N-vinylpyrrolidone 60 parts by weight Methyl methacrylate 20 parts by weight 2-hydroxyethyl methacrylate 5 parts by weight are mixed well. , A monomer solution. To this, 0.7 part by weight of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was placed in a glass tube and heated under nitrogen at 42 ° C. for 5 hours.
Polymerization was performed at 60 ° C. for 15 hours and at 85 ° C. for 2 hours to obtain a colorless and transparent copolymer. This copolymer was ground and polished to prepare a test piece (about 12 mmφ × 0.8 mm). Moisture content A test piece is put in a vacuum drier and placed under reduced pressure at 25 ° C. for 24 hours, and the dry weight after that is determined and defined as Dw. Next, the dried test piece was immersed in physiological saline at 80 ° C. for 24 hours to be swollen, and then cooled, and the physiological saline was kept constant at 37 ° C., and the weight after reaching parallel swelling was determined, Let this be Ww. Bending test The above sample, which has reached parallel swelling, is bent 180 degrees and folded in two. Next, fold it in the opposite direction in the same way and make a two-fold fold. This operation counts as one bend. This operation is repeated. Judgment No change occurs after 30 times ◎ 20 times or more partially cracked ○ 10 times or more cracked △ Less than 10 times cracked × Result of Example (1) Moisture content 50.4% Bent Test ◎

[0016]

[Chemical 5]

Comparative Example (1) Instead of the dimethacrylic ester represented by the structural formula 3 in Example (1), 15 parts by weight of the dimethacrylic ester represented by the following chemical formula 6 (structural formula 4) was used. Is
Polymerization was carried out under exactly the same conditions as in Example (1).
The same test piece was prepared and the water content and bending test were performed. Results of Comparative Example (1) Moisture content 41.2% Bending test △

[0018]

[Chemical 6]

Example (2) 10 parts by weight of a diacrylic ester represented by the following chemical formula 7 (structural formula 5) N-vinylpyrrolidone 65 parts by weight Methyl methacrylate 20 parts by weight 2-hydroxyethyl methacrylate 5 parts by weight are mixed well. , A monomer solution. To this, 0.7 part by weight of azobisisobutyronitrile was added as a polymerization initiator, and the mixture was placed in a glass tube and heated under nitrogen at 42 ° C. for 5 hours.
Polymerization was performed at 60 ° C. for 15 hours and at 85 ° C. for 2 hours to obtain a colorless and transparent copolymer. The same test piece as in Example (1) was prepared, and the water content and bending test were performed. Results of Example (2) Moisture content 60.8% Bending test ◎

[0020]

[Chemical 7]

Example (3) 3 parts by weight of the diacrylic ester represented by the above structural formula 5 N-vinylpyrrolidone 68 parts by weight Methyl methacrylate 20 parts by weight 2-hydroxyethyl methacrylate 5 parts by weight Stearyl methacrylate 4 parts by weight Polymerization was performed under exactly the same conditions as in Example (1) to prepare the same test piece as in Example (1), and the water content and bending test were performed. Results of Example (3) Moisture content 72.7% Bending test ◎

Example (4) Dimethacrylic ester represented by the following chemical formula 8 (Structure 6) 5 parts by weight N-vinylpyrrolidone 65 parts by weight Methyl methacrylate 20 parts by weight 2-hydroxyethyl methacrylate 5 parts by weight 2-ethylhexyl methacrylate 5 Polymerization was performed under exactly the same conditions as in Example (1) except for parts by weight, and the same test piece as in Example (1) was prepared, and the water content and bending test were performed. Results of Example (4) Moisture content 62.7% Bending test ◎

[0023]

[Chemical 8]

Claims (1)

[Claims] 1. The following chemical formula 1 (structural formula 1) or the following chemical formula 2
2 to 50 parts by weight of a diacrylic (methacrylic) ester represented by (Structural Formula 2), 20 to 90 parts by weight of vinylpyrrolidone and 2-hydroxyethyl methacrylate, and 8 to 50 parts by weight of a monomer copolymerizable therewith. A hydrous contact lens with a water content of 50% or more and high bending strength. [Chemical 1] [Chemical 2]