JPS61205901A - High moisture content contact lens - Google Patents

Abstract

PURPOSE:To obtain the titled lens having a high moisture content, a coloress and a transparence and a good mechanical strength. CONSTITUTION:The titled lens is a copolymer contg. 60-95wt% N vinyl pyrolidone, 5-40wt% a kind of a prescribed hydrophobic monomer, 0-20wt% unsatd. carboxylic acid having an ethylenic unsatd. binding and 0.02-0.3wt% at least one of a crosslinking agent shown by formulas I and II. The moisture content is >=60wt%. The hydrophobic monomer comprises a phenyl(meth) acrylate, a benzyl(meth)acrylate, a phenoxy ethyl(meth)acrylate and a cyclohexyl (meth)acrylate. The hydrophobic monomers as mentioned above are useful to control the moisture content and to increase the tensile strength. The cross linking agents shown by formulas I and II are the essential components for controlling the moisture content and increasing the tensile strength. By constitut ing as mentioned above, the title lens having the high moisture content, the excellent transparence and the mechanical strength is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel high water content contact lens, and more particularly to a high water content contact lens that has a high water content and a large mechanical strength, and is colorless and transparent.

Conventionally, homopolymers or copolymers of acrylic derivatives having OHM have been mainly used as soft contact lens materials. These materials have the property of absorbing water and swelling, have good transparency, and have excellent machinability, so they are suitable for producing soft contact lenses that are comfortable to wear.

Furthermore, in recent years, the water content of lens materials has been reduced to -li! ! As a result, high water content soft contact lenses have emerged that are intended for long-term continuous wear. This high water content soft contact lens is made from a material whose main component is N-vinylpyrrolidone, so it can absorb a large amount of water, so it supplies enough oxygen, which is physiologically necessary for the cornea, through the lens and maintains the metabolic function of the cornea. This contributes to physiological safety for the eyes.

However, when the water content of this material increases, its strength rapidly decreases, resulting in problems with durability, such as damage to the lens or scratches on the lens surface. In addition, the water retention properties of the material itself are low, so the lenses dry out easily.
Another drawback is that the shape is unstable.

As a result of intensive research aimed at improving the drawbacks of such high water content soft contact lenses, the present inventors found that by copolymerizing N-vinylpyrrolidone, a hydrophobic heptamer monounsaturated carboxylic acid, and a specific crosslinking agent in a certain proportion. They discovered that high moisture content and high strength can be achieved at the same time, and completed the present invention.

An object of the present invention is to provide a contact lens that has both a high water content of 60% or more and high tensile strength.

Another object of the present invention is to provide a high water content contact lens that has high oxygen permeability and can be worn continuously for a long period of time.

Another object of the present invention is to provide a colorless and transparent high water content contact lens.

The present invention comprises 60 to 95% of N-vinylpyrrolidone, 5 to 4 hydrophobic heptamers of at least species selected from Group A.
0% by weight, 0-20% by weight of an unsaturated carboxylic acid having one ethylenically unsaturated bond, and 0.02-3.0% by weight of at least one crosslinking agent selected from Group B. A component of the invention is a high water content contact lens made of a polymer and having a water content of 60% or more.

(Group A) Phenyl acrylates, benzyl acrylates, nonyl methacrylates, benzyl methacrylates, phenoxyethyl acrylate, phenoxyethyl methacrylate cyclohexyl acrylate, cyclohexyl methacrylate-1 to (B group) X In group XA Examples of phenyl acrylates include phenyl acrylate, 0-methylphenylacrylate, m-methylphenylacrylate, p-methylphenylacrylate, 0-methoxyphenylacrylate, m-methoxyphenylacrylate, p-me]xyphenylacrylate, 0- Examples of benzyl acrylates include ethoxyphenylacrylate, m-1 toxyphenylacrylate, p-1 toxyphenylacrylate, biphenylacrylate, 0-benzylphenyl acrylate, m-benzylphenyl acrylate, p-benzylphenyl acrylate, etc. 0-Methylbenzyl acrylate, m-methylbenzyl acrylate, p-methylbenzyl acrylate, 0-methoxyphenylacrylate, m-methoxybenzyl acrylate, p-methoxybenzyl acrylate-1, 〇-ethoxybenzyl acrylate, m-ethoxybenzyl Acrylate, p-ethoxybenzyl acrylate, o-n
-Butylbenzyl acrylate, m-n-butylbenzyl acrylate-1~, p-n-butylbenzyl acrylate, 0-phenoxybenzyl acrylate, m-phenoxybenzyl acrylate, p-phenoxybenzyl acrylate, m-phenylbenzyl acrylate, O −
Phenyl methacrylates such as phenylbenzyl acrylate, p-phenylbenzyl acrylate, etc.
Phenyl methacrylate, 0-methylphenyl methacrylate, m-methylphenyl methacrylate, p-methylphenyl methacrylate, 0-methoxyphenyl methacrylate, m-methoxyphenyl methacrylate, p
-methoxyphenyl methacrylate-1, biphenyl methacrylate, O-benzylphenyl methacrylate, m
-benzylphenyl methacrylate, p-pensylphenyl methacrylate, etc., benzyl methacrylate-1~, benzyl methacrylate, 0-methylbenzyl methacrylate, m-methylbenzyl methacrylate,
p-Methylbenzyl methacrylate-1, O-mel-xybenzyl methacrylate, m-methoxybenzyl methacrylate, p-mel-xybenzyl methacrylate, 0
-Ethoxybenzyl methacrylate, m-ethoxybenzyl methacrylate, p-ethoxybenzyl methacrylate, o-n-butylbenzyl methacrylate, m-n
-butylbenzyl methacrylate-1-1p-n-butylbenzyl methacrylate, O-phenoxybenzyl methacrylate, m-phenoxybenzyl methacrylate-1~,
Examples include p-phenoxybenzyl methacrylate, 0-phenylbenzyl methacrylate, m-phenylbenzyl methacrylate, and p-phenylbenzyl methacrylate.

The hydrophobic property of AnY is effective for controlling the water content and imparting tensile strength, but among them, benzyl methacrylates have a great effect on imparting tensile strength.

Group B crosslinking agents are essential for controlling moisture content and imparting tensile strength, but long chain crosslinking agents have a particularly strong effect on imparting tensile strength.

Even if commonly used short chain crosslinking agents such as ethylene glycol dimethacrylate and allyl methacrylate are used, the tensile strength of high water content polymers cannot be significantly improved. Furthermore, if an extremely long chain crosslinking agent such as polyester glycol dimethacrylate (for example, 30 moles of ethylene oxide is added) is used, the strength of the high water content polymer cannot be improved. This is undesirable because the polishability decreases.

Furthermore, in order to make the present invention more effective, it is desirable to use an unsaturated carboxylic acid having one ethylenically unsaturated bond. By using the unsaturated carboxylic acid in combination, it becomes easier to obtain a contact lens with a higher water content. Unsaturated carboxylic acids that can be used in the present invention include:
Acrylic acid, methacrylic acid, itaconic acid, crotonic acid,
Examples include pyruvic acid, fumaric acid, and maleic acid.

The amount of the crosslinking agent added varies depending on the type of crosslinking agent used, but is selected from a range of 0.02 to 30% by width. If the amount used is outside this range, the tensile strength will be extremely low and it cannot be used practically. By using an appropriate amount of the crosslinking agent of the present invention, the tensile strength can be improved more smoothly than when no crosslinking agent is used.

The high water content contact lens of the present invention includes 60 to 95% by weight of N-vinylpyrrolidone, 5 to 40% by weight of at least one hydrophobic heptamine selected from Group A, and a crosslinking agent of 002 and 002% by weight selected from Group B. ~30 For Shigekawa, pour a liquid mixture of 0-20 TfX quasi-% unsaturated carboxylic acid that eliminates one ethylenically unsaturated bond and 0.01-05% polymerization initiator 6% by weight into the specified mold. After sealing, the rod is heated for a certain period of time in a constant temperature bath, and the resulting rod is cut and processed at a certain period of time.
It can be obtained by polishing to obtain a lens, which is then saturated and swollen in physiological saline.

Note that it is also possible to adopt a method of directly forming the contact 1 to lens shape by casting polymerization, a method of performing spin xest while irradiating ultraviolet rays, etc.

Examples of the polymerization initiator used in the present invention include azo-based initiators such as azobisisobutyronitrile and azobisvaleronitrile;
Peroxide-based initiators such as 1 to 1 can be mentioned.

The contact lenses of the present invention obtained as described above have the following excellent properties.

(1) N-vinylpyrrolidone, a hydrophilic material,
Because it has a high water content, it can pass through the cornea as much oxygen as necessary for physiological purposes.

(Despite being a high water content contact lens, it has a tensile strength that is unmatched by similar conventional contact lenses.

(3) The contact lens of the present invention is colorless and transparent, without the pale yellow coloring unlike conventionally commercially available polyN-vinylpyrrolidone soft contact lenses, and has high visible light transmittance.

(4) There is little variation in the lens shape in the expanded state. Conventionally used poly-N-vinylpyrrolidone-based high water content contact lenses do not have a strong water retention capacity of the material itself, so when used in a dry atmosphere, the water in the lens evaporates and the water content changes. As a result, defects such as the lens shape deviating from the set shape occurred.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, all component parts are expressed as heavy + H parts.

Example 1 90 parts of N-vinylpyrrolidone, 10 parts of benzyl methacrylate, 0 parts of tetraethylene glycol dimethacrylate
．． A mixed solution consisting of 50 parts of Azogo Subare and 0.05 parts of Toryl was poured into a mold, the mold was sealed 1.j and then heated. Heating is from 30℃ to 115℃ in a constant temperature bath.
R for 4 hours? It was warm. After the polymerization was completed, the copolymer was cooled until it was knitted, and then the copolymer was taken out from the mold.

The copolymer was a colorless and transparent hard material.

This is then cut and polished into a contact lens shape using normal processing techniques to produce a contact lens. 1. :.

Next, it was immersed in 0.9% physiological saline to make it sufficiently swollen. The lens goes into the swollen soft contact lens 1.
It was colorless and transparent as in the dry state.

The water content of this lens is 78%, and the oxygen permeability coefficient is 53×1
0” ml -cm/cm2- sec -mmmm1
l 30℃), tensile strength when hydrated is 200g/mm2
Met.

Examples 2 to 13 Saturated swollen contact lenses were produced in the same manner as in Example 1. The measurement results are shown in Table 1. The contact lenses obtained in all Examples were colorless and transparent, showed higher oxygen permeability than Comparative Examples, and had a high tensile strength never seen before as a high water content contact lens.

Such high strength was first achieved by combining N-vinylpyrrolidone with a specific hydrophobic hexamer having a benzene ring or cyclohexyl ring and a specific long-chain crosslinking agent. This is an effect unique to the invention. (Left below) (Table 1) (Nanatsumar abbreviation) NVP N-vinylpyrrolidone PHM△ Phenyl methacrylate-1 to PEMA
Phenoxyethyl methacrylate MM△ Methyl methacrylate MBMA ρ-Methoxybenzyl methacrylate B
PMA D-benzylphenyl methacrylate Bz
MA Benzyl methacrylate CHM△ Cyclohexyl methacrylate-1-8 Tetra-1-ethylene glycol dimethacrylate (a=4) 81-lipropylene glycol dimethacrylate (b=
3> C polyethylene glycol dimethacrylate (a = 9) D polypropylene glycol diacrylate (c = 9) E polyethylene glycol dimethacrylate
(a = 14) F ethylene glycol dimethacrylate-1~G
Allyl methacrylate 1-1 Vinyl methacrylate MAA Methacrylic acid A△ Acrylic acid IA Iteric acid (Note 1) Wl is the weight at saturated water content W2 is the weight when the lens is dehydrated and dried 1j1 (Note 2) Oxygen permeability coefficient was measured at 30° C. using a Seika Sen-type film oxygen permeability meter (manufactured by Rika Seiki Kogyo). Unit Lt 1
0-”ml-crn/cm2-sec
-mm11g.

(I Lord 3)

Claims (1)

[Claims] 1 60-95% by weight of N-vinylpyrrolidone, 5-40% by weight of at least one hydrophobic monomer selected from Group A, 0- unsaturated carboxylic acid having one ethylenically unsaturated bond A high water content contact lens having a water content of 60% or more, comprising a copolymer containing 20% by weight and 0.02-0.3% by weight of at least one crosslinking agent selected from Group B. (Group A) Phenyl acrylates, benzyl acrylates, phenyl methacrylates, benzyl methacrylates, phenoxyethyl acrylate, phenoxyethyl methacrylate cyclohexyl acrylate, cyclohexyl methacrylate (Group B) ▲Mathematical formulas, chemical formulas, tables, etc.▼(X is H or CH
_3, a is an integer from 3 to 23) ▲Mathematical formulas, chemical formulas, tables, etc.▼(X is H or CH
_3, b is an integer from 2 to 14) ▲Mathematical formulas, chemical formulas, tables, etc.▼(X is H or CH
_3, c is an integer from 3 to 14)