JPS58172618A - Contact lens - Google Patents

Abstract

PURPOSE:To obtain a contact lens with low water content and high oxygen permeability by adding alkyl methacrylate and a cross-linking agent to one or both of specified 2 kinds of methacrylates as hydrophilic monomers and polymerizing the monomer mixture to prepare a copolymer. CONSTITUTION:Alkyl methacrylate and a cross-linking agent are added to diethylene glycol monomethyl ether methacrylate and/or triethylene glycol monomethyl ether methacrylate as hydrophilic monomers so as to adjust the amount of the hydrophilic monomers to 50-90wt% of the total amount of the monomer mixture. The monomer mixture is polymerized to prepare a copolymer with <=15wt% water content. A contact lens is made of the copolymer. The cross- linking agent is a monomer having >=2 polymerizable functional groups such as allyl methacrylate or ethylene glycol dimethacrylate. The structure of the copolymer is porous, and when the copolymer is in a bulky state due to steric hindrance, it has higher oxygen permeability.

Description

[Detailed description of the invention] The present invention relates to a novel contact lens.

In particular, the present invention relates to a low water content, high oxygen permeability contact lens made of a copolymer having a low water content of 15% by weight or less and exhibiting extremely high oxygen permeability.

Conventionally, contact lenses have been broadly classified into non-hydrophobic types and hydrous types.

Typical non-water-containing contact lenses are made with polymethyl methacrylate as the main ingredient, but since this has poor oxygen permeability, the cornea (the black part of the eye) tends to become oxygen-deficient.

If the condition continues, the normal metabolism of the cornea will be inhibited, causing injury and death.

In order to improve the oxygen permeability of contact lenses, contact lenses containing silicone rubber materials as a main component have been provided.

Although it does have good oxygen permeability, it is highly hydrophobic and has poor water wettability, so lipids and proteins adhere to the lens surface, making the lens cloudy and cloudy, making it optically unstable. It has the disadvantage of being easy.

Water-containing contact lenses are mainly made of 2-hydroxyethyl methacrylate and have a water content of about 30 to 40% by weight, but this is insufficient to supply the necessary amount of oxygen to the cornea, and from that point of view, 4M -High water content contact lenses have been proposed that use high water content materials such as vinylpyrrolidone to increase the water content. Although these highly water-containing lenses are made of a transparent material, the standard shape of the lens tends to change when the lens is worn on the eye, resulting in unstable visual acuity.

In addition, due to the high moisture content, the durability of the material is compromised and it suffers from breakage.

The present invention has a water content as low as 15% or less, which eliminates the disadvantages of paper, and even at such a low water content, it has high oxygen permeability, that is, an oxygen permeability coefficient of 1.
5 X 10-” CC@an/cfR2・sec
The purpose of the present invention is to provide a low water content, oxygen permeable contact lens that exhibits , mmHg or more.

The contact lens of the present invention uses diethylene glycol monomethyl ether methacrylate and/or triethylene glycol monomethyl ether methacrylate as hydrophilic monomers, and uses 50 to 1...1°90tt% of the total weight of the monomer mixture. This contact lens is made of a copolymer obtained by polymerizing a monomer mixture containing an alkyl methacrylate and a crosslinking agent, and has a water content of 15 or less.

Hydrophilic monomers such as diethylene glycol monomethyl ether methacrylate and triethylene glycol monomethyl ether methacrylate mentioned above have a property that the softening point of their homopolymers is below room temperature. Compared to monomers, it is possible to produce contact lenses from copolymers using these hydrophilic monomers, which are flexible and have good shape recovery.

i9. Alkyl methacrylate gives the resulting copolymer a porous structure and a reinforcing effect, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Linear ones such as amyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and branched ones such as isobutyl methacrylate, inamyl methacrylate, inlauryl methacrylate, intridecyl methacrylate, 2-ethylhexyl methacrylate, tert-butyl methacrylate. etc. can be mentioned.

As a crosslinking agent, a monomer having two or more polymerizable functional groups, such as allyl methacrylate, ethylene glycol dimethacrylate, 5 ethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Examples include triethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, trimethylpro, and trimethacrylate.

Art) Ethylene glycol monomethyl ether methacrylate is extracted with a water content of about 60% by weight and 11% as a tower body, and triethylene glycol monomethyl ether methacrylate is extracted with a water content of about 9%. ．． Since it is a highly water-containing material having a water content of about 0 weight, in the present invention, it is preferable to use the following compounding lance.

That is, in the case of diethylene glycol monomethyl ether methacrylate, about 5 to 29% by weight of 1 alkyl methacrylate and about 1% by weight of crosslinking agent based on about 70 to 90% by weight of diethylene glycol monomethyl ether methacrylate.
Select each in the range of 2 to 10 weight, and)
In the case of IJ ethylene glycol monomethyl ether methacrylate, the triethylene glycol monomethyl ether methacrylate is about 50 to 701 children, while the alkyl methacrylate is about 20 to 49 weight-1, and the crosslinking agent is about α2 to
Each is selected within a range of about 12 weights.

The contact lens of the present invention is flexible and has good shape recovery properties, but if too much C alkyl methacrylate is used as a monomer component, it becomes stiff and has poor flexibility. Also, if too little alkyl methacrylate is used, it becomes reinforced. It's not 1st in terms of effectiveness.

If the copolymer structure is porous and bulky due to steric hindrance, it will have higher oxygen permeability. Preferably, those having branched and long chains, such as 2-ethylhexyl methacrylate,
Among linear alkyl methacrylates, those having particularly long chains, such as lauryl methacrylate, are preferred. Of course, linear and relatively short chain ones such as methyl methacrylate can also be used in combination with the branched or long chain alkyl methacrylates.
It is T-noh.

If the crosslinking agent is used in an unnecessarily large amount, it will adversely affect the porous structure, which is undesirable. If the lid is too small, the shape stability of the contact lens will be weakened.

Since the copolymer in the present invention is an elastic body, the molding method (
It is appropriate to manufacture by molding using a molding method.

The mold is made into a concave or convex mold having a lens shape on the inner surface by cutting and polishing or injection using a mold.

A hydrophilic monomer that can be used in the concave mold using a conventional molding method using this mold.

a mixture of an alkyl methacrylate, a crosslinking agent, and a commonly used polymerization initiator, such as benzoyl peroxide,
Mixture of monomers such as azobisisobutyronitrile, azobisdimethylvaleronitrile, etc. *Approx. α per 100 parts by weight
After pouring about 0.5 to 1 part by weight, a convex mold is placed on top of the concave mold, heated with clamps, and cooled after death. Thereafter, the concave and convex molds are separated to produce a copolymer.

When the copolymer of the present invention is manufactured using a molding method, the inner surface of the mold can be shaped accurately because the material shrinks little during the copolymerization reaction when the mixture is injected into the mold. It is transferred to the copolymer and can be molded into a standard contact lens shape.

The contact lens of the present invention is formed by hydrating the copolymer produced as described above by means such as immersion in an aqueous solution to form a soft contact lens.

A contact lens made of the copolymer of the present invention has the following excellent properties.

(1) Oxygen permeability coefficient is 1.5 X j O-” CC-
t-II#/cw2# sea-mnHg or higher,
It has a #R main permeation ability equivalent to a high water content contact lens with a water content of about 50% by weight or more.

(2) Because it has a low water content with a water content of 15% by weight or less,
The shape stability of the lens is good, resulting in stable vision and
Because the material is hydrophilic, it is difficult for eye oil and proteins to adhere to the lens surface.

(3) It has excellent durability and shows no extreme deterioration in strength when swollen with water, as in highly water-containing contact lenses.

(4) The lens is colorless and transparent and has good transparency for visible light.

The present invention will be explained in more detail with reference to Examples below.

Example Polypropylene was used as a mold for molding Luns, and a concave mold and a convex mold having a predetermined shape on the inner surface were formed by machining such as cutting and polishing.

A mixed solution of 80 parts by weight of diethylene glycol monomethyl ether methacrylate, 10 parts by weight of lauryl methacrylate, and 10 parts by weight of allyl methacrylate and a polymerization initiator azobisdimethylvaleronitrile were added to 100 parts by weight of the monomer mixture in the concave mold for the mold. The convex mold was placed on top of the concave mold, and the concave and convex molds were held together with clamps, being careful not to trap any air vesicles.

Place this in a hot air circulation dryer and dry at 60℃ for 5 hours.
Then at 70°C for 4 hours, then at 80°C for 5 hours, then at 90°C.
The mixture was heated stepwise by holding at 100° C. for 6 hours and then at 100° C. for 6 hours. After cooling to room temperature, the clamp was removed.

A mold consisting of a concave shape and a convex shape was immersed in distilled water and boiled to separate the concave shape and convex shape. After continued boiling for 111 hours, the inner part was formed into nine contact lenses by copolymerization.

A cough contact lens was immersed in 0.9% physiological saline to sufficiently moisten it to produce a contact lens.

The swollen soft contact lens was colorless and transparent, had good shape stability, had sufficient restoring power, and had good water wettability on the lens surface.

The soft contact lenses produced were of standard Habasecarp 900■, power-500D1 size 15.0m+, and thickness 0.1m.

When the physical properties of the soft contact lens were measured, the oxygen permeability coefficient was 18 x 110-1 OCC-I/L-In.
2.θec, mmHg (measured at 20°C using Seikaken-type film oxygen permeability meter, Riki Kozuki Kogyo ■) Moisture content is 41
It showed 11% (moisture content = X100: W is measured at 20° C. under heavy weight when swollen with water, W is measured under heavy weight during dehydration and drying).

To check the durability of contact lenses, use a cleaning solution for contact lenses (trade name: MeniClean, To:::,).

Using a cleaning sponge (made by Western contact lenses)
The product name: Silicone Buff (manufactured by Toyo Contact Lenses) was rubbed with fingers 7,200 times (approximately 2 years worth of daily cleaning).

After scrubbing, the lens was irradiated with light and magnified with a projector, and visually checked for changes in appearance, turbidity, coloration, and shape changes, and no abnormalities were found.

From the above results, it was confirmed that the lens according to this example had satisfactory physical properties and durability.

Example 2 80 parts by weight of diethylene glycol 7-methyl ether methacrylate, 1011 parts by weight of lauryl methacrylate,
A contact lens was formed in the same manner as in Example 1 from 10 parts by weight of ethylene glycol dimethacrylate and 1 part by weight of azobisdimethylvaleronitrile α.

Oxygen permeability coefficient 1.7 x 1O-10cc-yn/cm
2. e@aammHg moisture content 5.4% by weight, no abnormality in durability test.

Example 3 60 parts by weight of triethylene glycol monomethyl ether methacrylate, 5 parts by weight of 2-ethylhexyl methacrylate
A contact lens was formed in the same manner as in Example 1 from 0 parts by weight of allyl methacrylate, 10 parts by weight of allyl methacrylate, and 0.1 parts by weight of azobisdimethylvaleronitrile.

Oxygen permeability coefficient 2.6 x 10-"ec" (@/ff1
2m5ec*mmHg Moisture content 2.5% by weight, durability test No abnormalities.

Example 4 70 parts by weight of triethylene glycol monomethyl ether methacrylate, 2-ethylhexyl methacrylate 2
0 parts by weight of allyl methacrylate, 1.0 parts by weight of azobisdimethylvaleronitrile, and 0.1 parts by weight of azobisdimethylvaleronitrile using VCL in the same manner as in Example 1 from @5 to form a contact lens.

Oxygen permeability coefficient 2.4 x 10-' Occ, cm/
cm2-sec ・mmHg Moisture content 18% by weight, no abnormalities in durability test.

Example 5 60 parts by weight of triethylene glycol monomethyl ether methacrylate, 3 parts by weight of 2-ethylhexyl methacrylate
A contact lens was formed in the same manner as in Example 1 from 0% by weight, 10 parts by weight of trimethylolpropane trimethacrylate, and 0.1 parts by weight of agebisdimethylvaleronitrile.

Oxygen permeability coefficient 1.7 x 10-” cc, crn
/lx2 m sea *mmHg Water content 2.0 Weight-1 Durability test No abnormalities.

Example 6 85 parts by weight of diethylene glycol 7 methyl ether methacrylate, 14 parts by weight of 2-ethylhexyl methacrylate
A contact lens was formed in the same manner as in Example 1 from 1 part by weight, 1 part by weight of ethylene glycol dimethacrylate, and 0.1 part by weight of agebisdimethylvaleronitrile.

Oxygen permeability coefficient 2. OX 10-” cc, 6R/z2-
sea-mmHg moisture content 15.0% by weight, no abnormality in durability test.

Example 7 Triethylene glycol monomethyl ether methacrylate, 2-ethylhexyl methacrylate 2
A contact lens was formed in the same manner as in Example 1 from 9 parts by weight of allyl methacrylate, 1 part by weight of azobisdimethylvaleronitrile α.

Oxygen permeability coefficient 2.5 x 10-” cc-cm/an
2 ・sec ・mmHg Moisture content 1000% by weight, durability test No abnormality.

All of the lenses formed in Examples 2 to 7 were colorless and transparent, had good shape stability, and had optical restoring power, and the water wettability of the lens surface was also good. As for physical property values, all oxygen permeability coefficients are 1.5, as shown in the measurement results.
X10-CC-α/am2-ace-mmHg or more, and all water contents are 15 times IIS or less. Furthermore, durability was confirmed by rubbing the lenses with fingers in the same manner as in Example 1, and no abnormalities were observed in any of the lenses, demonstrating the superiority of the contact lenses of the present invention. .

Patent applicant: Toyo Contact Lens Co., Ltd. Representative Patent Attorney Yu Kano 109-

Claims (1)

[Claims] Diethylene glycol monomethyl ether methacrylate and triethylene glycol monomethyl ether methacrylate, either alone or both, are used as hydrophilic monomers, and 50 to 90% by weight of the total amount of the monomer mixture is used, and a 7-mer mixture is prepared by adding methacrylate in alcohol and a crosslinking agent. 9.Contact lenses made of a copolymer with a water content of 15% or less.