JPS5828718A - Soft contact lens - Google Patents

Abstract

PURPOSE:To obtain a soft contact lens with a high water content and high strength by using a copolymer composed chiefly of dimenthylacrylamide, N-vinylpyrrolidone and alkyl methacrylate and prepared in the presence of specified cross-linking agents as a lens material. CONSTITUTION:A soft contact lens is formed with a copolymer consisting essentially of dimethylacrylamide, N-vinylpyrrolidone and alkyl methacrylate as a lens material. The copolymer is prepared by copolymn. in the presence of >=2 kinds of cross-linking agents such as methacriloyloxyethyl acrylate and allyl acrylate, or vinyl acrylate and allyl methacrylate. The preferred blending ratio between a mixture of dimethylacrylamide with N-vinylpyrrolidone and alkyl methacrylate is about 80:20- about 95:5 by weight, and the preferred total amount of the used cross-linking agents is about 0.1-2.0wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a soft contact lens made of a copolymer containing dimethylacrylamide, N-vinylpyrrolidone, and alkyl methacrylate as main components, in which methacryloyl is used as a crosslinking agent during copolymerization of the components. A soft contact lens characterized by using two or more selected from the group consisting of oxyethyl acrylate and allyl acrylate or vinyl acrylate and allyl methacrylate, the purpose of which is to have a high water content and at the same time The purpose of the present invention is to provide a highly water-containing soft contact lens that is colorless and transparent and has great strength.

Traditionally, OH was the main material for soft contact lenses.
Homopolymers or copolymers of acrylic derivatives containing groups have been used.

These materials have the property of absorbing all water and swelling, have good transparency, and are excellent in machinability, so they can be said to be suitable for obtaining soft contact lenses that are comfortable to wear.

Furthermore, in recent years, by increasing the water content of lens materials,
Highly water-containing soft contact lenses for the purpose of long-term wear have appeared.

This highly water-containing soft contact lens is made of a material whose main component is N-vinylpyrrolidone and absorbs a lot of water, so it supplies a sufficient amount of oxygen necessary for the corneal physiology through the lens 7F, allowing the corneal metabolic function. This contributes to physiological safety for the eyes.

However, when the material swells, its strength decreases significantly;
This causes problems with durability, such as damage to the lens or scratches on the lens surface.

The high water content material containing N-vinylpyrrolidone as a main component has low strength, and the higher the water content, the further the material strength decreases.

Therefore, the strength of the material is improved by copolymerizing various hydrophobic monomers as reinforcing agents, but in an attempt to obtain stronger materials, increasing the amount of reinforcing agents used leads to a decrease in water content. The lens material becomes cloudy, making it undesirable as a contact lens.

Therefore, even when a sufficient amount of reinforcing agent is copolymerized,
In order to maintain high water content, dimethylacrylamide, which has a higher water absorption capacity than N-vinylpyrrolidone, is
It is conceivable to use it in addition to vinylpyrrolidone, but in this case too, in the usual copolymerization format, the transparency of the copolymer tends to decrease, making it impossible to obtain a material that is satisfactory as a material for contact lenses. This is thought to be due to poor copolymerizability due to the fact that the hydrophobic monomer used as a reinforcing material has a different polymerizable group from that of a hydrophilic monomer such as dimethyl acrylamide.Therefore, in order to improve the copolymerizability, Attention was focused on utilizing a crosslinking agent that should contain all the monomers used, such as hydrophilic monomers such as dimethylacrylamide and N-vinylpyrrolidone, and alkyl methacrylate used as a reinforcing agent.

As a result, dimethylacrylamide, N-vinylpyrrolidone and alkyl methacrylate were used as main components, and the crosslinking agent was selected from the group consisting of methacryloyloxyethyl acrylate and allyl acrylate or vinyl acrylate and allyl methacrylate. When using a mixture of two or more types, we succeeded in obtaining a colorless and transparent highly water-containing material.

In this invention, the ratio of dimethylacrylamide and N-vinylpyrrolidone used is about 75:25 to 75:25 by weight.
approximately 20:80 dimethylacrylamide and N
- The ratio of the mixture with vinylpyrrolidone and the alkyl methacrylate is about 80:20 to about 95:
5, and the total amount of crosslinking agent used is about 0.1 to 2.0
It is desirable that the weight be in the range of 1tt4.

5 - As the alkyl methacrylate used in this invention, for example, methyl methacrylate 1. Examples include ethyl methacrylate, butyl methacrylate, n-amyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, decyl methacrylate, undecyl methacrylate, lauryl methacrylate, stearyl methacrylate, ethylhexyl methacrylate, etc., and one or more of these are selectively used. shall be.

The crosslinking agent has two different polymerizable groups as shown below in order to link all the monomers used, including dimethylacrylamide, hydrophilic monomers such as N-vinylpyrrolidone, and hydrophobic monomers such as alkyl methacrylate. .

Methacryloyloxyethyl acrylate Allyl acrylate Vinyl acrylate 0H2 = OHOOOH = OII2 1 Allyl methacrylate 1 Among the crosslinking agents, methacryloyloxyethyl acrylate is a new compound, and is produced by reacting 2-hydroxyethyl acrylate with methacrylic acid chloride to form 14I
It will be done.

That is, (1) 2-hydroxyethyl acrylate 5B in the flask? , triethylamine, and acetone.

(2) Attach a dropping funnel containing methacrylic acid chloride +' 54 f k and drop methacrylic acid chloride while stirring and cooling.

(3) Filter the reaction mixture and wash the organic layer of P solution with water.

(4) After opening itt for a certain period of time, distillation was performed to obtain methacryloyloxyethyl acrylate.

This compound is a slightly viscous colorless and transparent liquid with a boiling point of 56
°C (under 0,15 mmHg), refractive index 1.4534 n
, o, elemental analysis values are actually measured values 058.5Li6, H6,
7%, 035.0%, theoretical value 05a7%, H6,5
%, 034.8%.

Next, allyl acrylate and vinyl acrylate exhibit similar properties in their respective allyl groups and vinyl groups, and thus exhibit similar reactions with the acryloyl groups of both, and can be used as substitutes.

Furthermore, other known crosslinking agents may be used in combination with these crosslinking agents, such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, trimethylolpropane trimethacrylate. One or more of these may be used.

The soft contact lens of this invention is manufactured as follows.

Using dimethylacrylamide, N-vinylpyrrolidone and alkyl methacrylate, and other known hydrophilic polymers and reinforcing components as necessary, the crosslinking agent is selected from the group consisting of methacryloyloxyethyl acrylate and allyl acrylate or vinyl acrylate and allyl methacrylate. A mixture of two or more of these and, if necessary, other known crosslinking agents, in the presence of one or more polymerization initiators, such as benzoyl peroxide, azobisisobutyronitrile, azobisdimethylvaleronitrile, etc. The resulting copolymer is subjected to conventional machining processes such as cutting and polishing, and immersion in an aqueous solution to obtain a soft contact lens.

The copolymer used in this invention has the following excellent properties when processed into soft contact lenses.

(1) A highly water-containing material, dimethylacrylamide, is used and has a high water content that allows permeation of a sufficient amount of oxygen necessary for corneal physiology. Moisture content approximately 50-85% by weight, oxygen permeability coefficient 1.5-5.0X10-'°"・
-Tn2. BeQ,. . 1.6 (2) The use of a specific crosslinking agent prevents clouding during polymerization or swelling of the material, so the lens is colorless and transparent and has good visible light transmittance.

Visible light transmittance of 90 cm or more.

(3) Due to the use of a reinforcing agent, there is no extreme decrease in external strength in the swollen state, and the lens has excellent fire resistance despite being a highly water-containing lens.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 20 parts by weight of dimethylacrylamide, 67.2 parts by weight of N-vinylpyrrolidone, 12 parts by weight of lauryl methacrylate, 0.4 parts by weight of allyl acrylate, and 0.4 parts by weight of methacryloyloxyethyl acrylate were thoroughly mixed. After that, 0.07 parts by weight of azobisisobutyronitrile and 0.06 parts by weight of azobisdimer 10-tilvaleronitrile were added to 100 parts by weight of the monomer mixture for polymerization to make it easier to mold the mixture into contact lenses. The mixture was injected into a mold formed into a desired shape such as a rod or plate. The mold was sealed and heated.

The mixture was held at 80°C for 1 hour, then at 90°C for 1 hour, then at 100°C for 1 hour, and then at 110°C for 1 hour, during which time the polymerization reaction was sufficiently carried out.

After the reaction was completed, the copolymer was cooled to room temperature and then released from the mold.

The copolymer was colorless, transparent, and hard.

This was cut into the shape of a contact lens using normal processing techniques, cut, and polished (1') to produce a contact lens.

Next, the contact lenses were immersed in 9% physiological saline to sufficiently swell them.

The swollen soft contact lens was colorless and transparent, similar to the non-swollen state.

The physical property values and durability test results of the lens are shown below.

The lens specifications used for testing the physical properties of the lens were: base curve 9.00 mm, power -3.00 D, size 13.5 bleached, thickness 0, 1
m (However, only the visible light transmittance uses a film with a thickness of 1.0 mm.) The conventional soft contact lenses shown for comparison are as follows:
Meniconft A (composed of a copolymer mainly containing 2-hydroxyethyl methacrylate gold) manufactured by Toyo Contact Lenses Co., Ltd. was used.

Measured value Note 1 Moisture content ('rfJ:'-1stφ) - AnyLx
1 o.

W is the weight of the lens when it swells with water 11w is the weight of the lens when it is dehydrated and dried Note 2 Oxygen permeability coefficient (cc, ~20 days θc, m　g)
Convenient film oxygen permeability meter (Rika Seiki Kogyo Co., Ltd.)
Note 3: Visible light transmittance (%) measured with visible light (680-70
Measurement method 4: Transmittance at 0nm) is measured using luminous intensity TL (manufactured by Takashi Seisakusho).Refractive index (nD) is measured using Elma's new Atsube refractometer.
(manufactured by Elma Optical Co., Ltd.) Note 5 Linear swelling coefficient = Ts L is the diameter of the lens when it is swollen with water, including the diameter of the lens when it is dehydrated and dried Test results regarding lens durability Boiling resistance 0.9% physiological Immerse the lens in saline solution and boil continuously for 24 hours.
No abnormalities were observed at 0 hours (approximately 2 years of boiling disinfection treatment every day).

Using a washing and abrasion-resistant contact lens cleaning solution (product name: Menicuri 13-1, manufactured by Toyo Contact Lenses Co., Ltd.), use your hands and fingers on a cleaning sponge (product name: Silicone Puff, manufactured by Toyo Contact Lenses Co., Ltd.). No abnormalities were observed after 7,200 scrubbings (about 2 years worth of daily washing). Users must boil the lenses every day to disinfect them, so we test their durability during actual use and check for any abnormalities by shining light on the lenses after the test and magnifying them with a projector. The samples were visually observed and checked for changes in appearance, turbidity, coloration, and shape changes.

From the above results, it was confirmed that the soft contact lens had sufficiently satisfactory physical properties and durability.

Comparative Example 1 This comparative example concerns the stability and durability of copolymerization using the crosslinking agent used in Example 1.

In comparison with Example 1, the same amount of crosslinking agent was used in place of allyl methacrylate, and the polymerization reaction was carried out under the same conditions as in Example 1. After the completion of the reaction, the copolymerized product was released from the mold and processed into a plate with a thickness of 1.5 m for a white cloudiness test, and a plate with a thickness of 1.5 m for a durability test. Contact lenses were created using the same lens standards as

A copolymer prepared with the component amounts of Example 1 was similarly machined.

As a result, the copolymer of Comparative Example 1 had no difference in durability compared to Example 1, but it developed cloudiness and was an unsuitable material for contact lens materials.

Comparative Example 1 Example 1 When swollen with water 廿 - Durability test 2 No abnormality No abnormality Note 1 In the cloudiness test, the degree of white turbidity is observed with the naked eye, and the degree of white turbidity is observed in descending order of -, earth, +, 廿, 11) And so.

- is colorless and transparent, and citrus is opaque.

Note 2 The durability test was the same as the test conducted in Example 1.

Example 2 66 parts by weight of dimethylacrylamide, 54 parts by weight of N-vinylpyrrolidone, 9 parts by weight of stearyl methacrylate,
0.5 parts by weight of allyl methacrylate and 0.5 parts by weight of methacryloyloxyethyl acrylate were mixed, and as a polymerization initiator, 0.07 parts by weight of azobisisobutyronitrile and azobismethyl were added to 100 parts by weight of the monomer mixture for polymerization. A soft contact lens was prepared in the same manner as in Example 1 except that 0.03 parts by weight of valeronitrile was added. The physical properties of the lens were a water content of 70.9% by weight and a linear swelling coefficient of 1.55.

Example 3 Hydrophilic monomer dimethylacrylamide 30 parts by weight N
-Vinylpyrrolidone 54 〃2-
Hydroxyethyl methacrylate 5N Reinforcing agent lauryl methacrylate 10 Crosslinking agent allyl methacrylate 0.4
Methacryloyloxyethyl acrylate 0.6
Azobisisobutyronitrile 0
．． 054 7/Azobisdimethylvaleronitrile
0.023 A soft contact lens was prepared from the copolymer obtained in the same manner as in Example 1.

Lens physical properties Water content 71.1% by weight, linear swelling coefficient 1.54 Example 4 Hydrophilic monomer dimethylacrylamide 34 parts by weight N
-Vinylpyrrolid/ 51 〃Reinforcing agent meth υ lauryl tesylate 14 〃Crosslinking agent allyl methacrylate) Q, 5 1/
Allyl acrylate 0.5 polymerization initiator azobisisobutyronitrile 0.07 parts I-
1mer azobisdimethylvaleronitrile 0.031fi (
Soft contact lenses were made from the tripod-obtained copolymer.

Lens physical properties water content 6F 3.5% by weight, linear swelling coefficient 1.53 Example
5 Hydrophilic monomer dimethyl acrylamide 201 N-vinylpyrrolidone 64 2-hydroxyethyl methacrylate 5 Reinforcing agent lauryl decrylate 10 Crosslinking agent allyl methacrylate 0.4 Weight part allyl acrylate 0.6 Polymerization initiator Azobis Isobutyronitrile 0.054
#Azobisdimethylvaleronitrile 0.0
#23 A soft contact lens was prepared from the obtained copolymer.

18- Lens physical properties Water content: 69.8% by weight, Linear swelling coefficient: 1.52 Example 6 Hydrophilic monomer dimethylacrylamide 2z15 Heavy duty part N
-Vinylpyrrolidone 63.65 tt
Reinforcing agent lauryl methacrylate) 4.5 1/
Stearyl methacrylate) 4.5 1/Crosslinking agent allyl acrylate 0.6 methacryloyloxyethyl acrylate) 0.2 #Polymerization initiator azobisisobutyronitrile o, o y Part by weight Azobisdimethylvaleronitrile 0 .05
A soft contact lens was prepared from the obtained copolymer.

Lens physical properties Water content 77.0% by weight, linear swelling coefficient 1.67 Example 7 Hydrophilic monomer dimethylacrylamide 26.25 ft4
fiN-vinylpyrrolidone 61.25
/1 Reinforcing agent lauryl methacrylate 9 Vinyl acetate 6 Crosslinking agent allyl acrylate 0.3 Methacryloyloxyethyl acrylate 0.2
〃Polymerization initiator azobisisobutyronitrile 0.07K
Wμ Azobisdimethylvaleronitrile 0.0
Soft contact lenses were made from the 3# obtained copolymer.

Lens physical properties Water content 77.4% by weight, linear swelling coefficient 1.70 Example 8 Hydrophilic monomer dimethylacrylamide 20 parts by weight N-
Vinyl 2-day Ridone 60 〃2-Hydroxyethyl methacrylate) 10 M Mountain reinforcing agent lauryl methacrylate 9 〃Crosslinking agent Vinyl acrylate) 0.6 /
/methacryloyloxyethyl acrylate 0.3
u ethylene glycol dimethacrylate 0,1
〃Polymerization initiator azobisisobutyronitrile 0.07 double pupil azobisdimethylvaleroni) IJ 0.03 /
/A soft contact lens was created from the obtained copolymer.

Lens physical properties Water content 6a5% by weight, linear swelling coefficient 1.50Example 9 Hydrophilic monomer dimethylacrylamide 60 RouxN-vinylpyrrolidone 27.2nReinforcing agent Meclauryl methacrylate 12 Rt part 2
1- Crosslinking agent allyl methacrylate 0.2 parts by weight Allyl acrylate 0.2 methacryloyloxyethyl acrylate o, 4 Polymerization initiator azobisin butyronitrile 0.07 parts by weight azobisdimethylvaleronitrile 0.0
3 1/A soft contact lens was prepared from the obtained copolymer.

Lens physical properties water content 73.8% by weight, linear swelling coefficient 1.60 Example 1
0 Hydrophilic monomer dimethylacrylamide 50 tMN-vinylpyrrolidone 3o 2-hydroxyethyl methacrylate 10 I reinforcing agent lauryl methacrylate 9 Weight part crosslinking agent allyl methacrylate 0.3 Weight part 22- Vinyl acrylate 0.1 Heavy weight allyl acrylate) 0, 2/
/methacryloyloxyethyl acrylate 0.3
11 Ethylene glycol dimethacrylate 0.1# Polymerization initiator Azobisisobutyronitrile 0.07 Heavy electric part Azobisdimethylvaleronitrile 0.0
3 # A soft contact lens was prepared from the obtained copolymer.

Lens physical properties water content 72.6% by weight, linear swelling coefficient 1.56 Example 1
1 Hydrophilic monomer dimethyl acrylamide 30 Heavy moiety N-
Vinylpyrrolidone 55 〃2-Hydroxyethyl methacrylate 5 〃Reinforcing agent n-amyl methacrylate 9 Weight 15 Crosslinking agent Allyl methacrylate 0.3 Junku b Allyl acrylate) 0.5ijJ
Leg methacryloyloxyethyl acrylate) 0.2
/1 Polymerization initiator azobisin butyronitrile [1,07
tt part Azobisdimethylisovaleronitrile 0.
03 //Soft contact lenses were made from the obtained copolymer.

Lens physical properties Water content 76.3% by weight, linear swelling coefficient 1.65 Example 2~
No. 11 soft contact lenses were subjected to a boiling resistance test and a washing abrasion resistance test in the same manner as in Example 1, but no abnormalities were observed in either case.

Similarly, the results of the cloudiness test also showed -.

Patent Applicant: Toyo Contact Lens Co., Ltd. Patent Attorney Kano Written amendment (spontaneous) October 22, 1980 Commissioner of the Japan Patent Office 1 Indication of the case 1981 Patent Application No. 126840 Mei 2 Name: Soft contact lenses 3 Relationship with the case of the person making the amendment Patent applicant address: 5 Higashiwajima-cho, Nishi-ku, Nagoya, Aichi Prefecture Name: Toyo Contact Lens Co., Ltd. Representative 1) Kyo Naka - 4 Agent 5, subject of the amendment Detailed Explanation Column 6, Contents of Correction (2) Page 11, Line 6 “, then 1 hour at 60°C” was changed to [
The residue was kept at 60℃ for 1 hour in a company-style circulation dryer.'' (Second correction.

that's all

Claims (4)

[Claims] (1) :) A soft contact lens made of a copolymer mainly composed of methylacrylamide, N-vinylpyrrolidone, and alkyl methacrylate, in which methacryloyloxyethyl acrylate and allyl acrylate are used as crosslinking agents during copolymerization of the components. Or a soft contact lens characterized by using two or more types selected from the group consisting of vinyl acrylate and allyl methacrylate. (2) The ratio of dimethylacrylamide to N-vinylpyrrolidone used is about 75:25 to about 20:8 by weight.
0. The soft contact lens according to claim 1, wherein the soft contact lens is 0. (3) ') The ratio of the mixture of methylacrylamide and N-vinylpyrrolidone to the alkyl methacrylate is about 80:20 to about 95:5 by weight, according to claim 1 or 2. soft contact lenses. (4) The soft contact lens according to claim 1, 2, or 3, wherein the total amount of crosslinking agent used is about 0.1 to 2.0% by weight.