JPS6330818A - Material for soft contact lens - Google Patents

Abstract

PURPOSE:To obtain a material for a transparent soft content lens having excellent permeability by controlling the coefficient of water adsorption of a copolymer comprising a specific monomer and a hydrophilic monomer as a main component to <=10%. CONSTITUTION:The titled material is the material for the soft contact lens having <=10% coefficient of water-absorption composed of the copolymer which comprises 60-90pts.wt. the monomer shown by the formula and 5-40pts.wt. the hydrophilic monomer as the main component. The method of manufacturing the copolymer comprises the method of polymerizing in a forming die, the method of a spin-cast polymerization, and the method of forming after the polymerization. Among them, as the material of the contact lens is soft, the method of polymerizing in the forming die and the method of the spin-cast polymerization are preferably adopted. As said contact lens material has the good transparent, and the excellent oxygen permeability and the large strength, said material is most preferable to use for the titled lens.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel soft contact lens material, and more particularly to a transparent soft contact lens material with excellent gas permeability.

[Prior art]

In recent years, as the use of polymeric materials in the medical industry has progressed, interest in materials with special functions has increased. Among these, various materials have been studied for purposes such as gas permeability and antifouling properties in addition to compatibility with living organisms.

In order to obtain such materials, it is well known that hydrogels are used to provide a certain degree of flexibility from the viewpoint of biocompatibility, and the water content in the hydrogels is increased to increase gas permeability. It is being For this purpose, for example, N-vinylpyrrolidone or acrylamide can be used, but such hydrogels with high water content have low mechanical strength and have the problem that proteins and lipids can enter the material and deteriorate its properties. was there.

In order to improve the defects in mechanical strength, materials using alkyl methacrylate are known, for example as described in JP-A-54-147846, and in particular, contact lenses containing butyl methacrylate and butyl acrylate as main components are known. has been put into practical use. Although this material has the advantage of relatively high mechanical strength due to its low water content, its oxygen permeability is not very high and is therefore not satisfactory.

On the other hand, silicone rubber materials are also used as medical materials, but it has been reported that this material is extremely 18-aqueous and causes serious problems when used as a contact lens material. It was also a material that had a big problem with regard to lipid contamination.

In addition, various contact lens materials using fluorinated monomers have been studied.

For example, Japanese Patent Application Laid-Open No. 54-29660 discloses a contact lens material using fluoroalkyl methacrylate, but this material did not have a very high oxygen permeability and was not satisfactory.

Furthermore, in Japanese Patent Application Laid-Open No. 58-127914, a contact lens material was obtained using a monomer having a perfluoropolyether group, and a relatively high oxygen permeability coefficient was obtained.

However, the monomers disclosed in the above specification all have high molecular weights and contain many ether groups, making it difficult to purify them by distillation, recrystallization, etc. As such, purification was extremely complicated and time-consuming.

[Purpose of the invention]

An object of the present invention is to provide a transparent soft contact lens material with good gas permeability.

[Structure of the invention]

That is, the present invention provides a copolymer with a water content of 10% or less, which is composed of a copolymer mainly composed of 60 to 90 parts by weight of a monomer represented by the formula (■): (I) FF and 5 to 40 parts by weight of a wood-philic monomer. The present invention relates to materials for soft contact lenses.

The monomer of formula (I) (hereinafter referred to as component A) is the main monomer of the present invention, and has a large fluorine content (58,
7%) Also, since it contains two trifluoromethyl groups, it is possible to obtain a polymer with excellent oxygen permeability, and since the fluorine atom is directly bonded to the vinyl group, it has even better oxygen permeability. A polymer is obtained.

Furthermore, since it has an ether group in addition to an ester group, it has good compatibility with other monomers, and its chain is relatively short considering that it produces a polymer with a high oxygen permeability coefficient, so it can be easily purified by distillation. Can be done.

Hydrophilic monomer (hereinafter referred to as “B”) which is another essential component of the present invention
"component") is a monomer that imparts hydrophilicity to the copolymer as well as elongation and resilience. In other words, the homopolymer of component A has relatively poor elongation and resilience, and is a material that gives a "stiff" feel when made into contact lenses.In addition to improving this, it is also given hydrophilicity to make contact lenses. Component B is sometimes used to improve the water wettability of the surface.

Examples of component B include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxybutyl (meth)acrylate;
~ (Meth)acrylates with ether bonds such as methoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, diethylene glycol mono (meth)acrylate, N-vinyl-2-
Lactams such as pyrrolidone, ■-methyl-3-methylene-2-pyrrolidone, N-vinyl-2-hyheridone, N,
Acrylamides such as N-dimethylacrylamide,
Examples include (meth)acrylic acid 5, glycerol (meth)acrylate, 2-methylglycerol (meth)acrylate, and one or more of these can be used. Further, it is more preferable to use a monomer having an ether group from the viewpoint of oxygen permeability and resilience, and from the viewpoint of elongation and resilience, esters of acrylic acid are preferred.

Regarding the usage ratio of each component, if the amount of component A used is too small, there will be a problem that high oxygen permeability cannot be obtained.
If there are too many components, there is a problem that the copolymer will lack elongation and resilience. In addition, if the amount of daily ingredients used is too large, the moisture content of the material will increase, resulting in a problem such as a decrease in oxygen permeability.
There is some material deterioration due to boiling, which is a characteristic of the ingredients.

Therefore, the amount of each component to be blended is approximately 60 to 95 parts by weight of component A, and approximately 5 to 40 parts by weight of component A per 100 parts by weight of the total amount of components A and B. Particularly, component B is preferably used in an amount of about 5 to about 20 parts by weight.

Furthermore, in view of the aforementioned material deterioration due to boiling, the moisture content must be kept at 10% or less.

In the present invention, in addition to the A component and the B component, various components such as a hydrophobic upper crosslinking monomer and a dye can be copolymerized or added.

Examples of hydrophobic monomers are methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, isopropyl (meth)acrylate, tert-butyl (meth)acrylate. Acrylate, 2-
(Meth)acrylates such as ethylhexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, styrene, tert-butylstyrene, etc. One or more of these can be used. Among them,
It exhibits excellent properties as a soft material, and has 4 to 1 carbon atoms.
Ester of alkanol and methacrylic acid of No. 8 and alkyl acrylate are preferably used.

In addition, in order to increase the strength and flexibility of the copolymer without reducing its oxygen permeability, the hydrophobic monomer should be used in an amount of 20 parts by weight or less based on 100 parts by weight of the total amount of copolymer monomers excluding the crosslinking agent. is preferred.

In addition, for the purpose of improving the shape stability and organic solvent resistance of contact lenses, monomers having two or more polymerizable groups,
That is, it is preferable to include a crosslinking agent. Specific examples of crosslinking agents include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, allyl(meth)acrylate, divinylbenzene, hexamethylene bis(meth)acrylate, Examples include hydrophilic crosslinking agents and hydrophobic crosslinking agents such as glycerin di(meth)acrylate, and one or more types of these can be used. Further, as a crosslinking agent, for example, polyethylene glycol di(meth)acrylate is preferably used because it further improves resilience and flexibility.

However, if the amount of crosslinking agent used is too large, the material becomes brittle, so the amount of crosslinking agent used is approximately 5 parts by weight or less per 100 parts by weight of the total amount of component A, component B, and hydrophobic top layer. It is preferable to do so.

When these monomers are polymerized to obtain the desired copolymer, a known polymerization method, preferably a bulk polymerization method, is used, and a method of polymerization using ultraviolet rays, heat, etc. is preferred. Furthermore, a polymerization initiator can also be used, and suitable examples of such polymerization initiators include azobis compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile, and peroxides such as benzoyl peroxide. . And in that case, the polymerization generally takes place at about 0°C.
It is preferable to start the polymerization at such a temperature and then raise the temperature stepwise or continuously to complete the polymerization, in which case the final temperature is about 90°C.
It is preferable to set it as 0 degreeC - 150 degreeC.

In producing the copolymer used in the present invention, commonly known methods such as polymerization in a mold, spin cast polymerization, and molding after polymerization can be used. Among these, since the contact lens material of the present invention is soft, a method of polymerizing in a mold or a method of spin-cast polymerization is preferable.

The present invention will be explained in more detail with reference to examples below, but the present invention is not limited only to the examples.

〔Example〕

(Example 1) 7.5 g of component A and N-vinyl- 2-pyrrolidone 0.5 g, methoxytetraethylene glycol acrylate 2 g 1 allyl methacrylate 0.04 g, azobisdimethylvaleronitrile 0
．． 04 g of the mixture were polymerized in a hot air circulating dryer for 4 hours at 50°C, 2 hours at 70°C, 2 hours at 90°C and 2 hours at 110°C.

The resulting film was punched out using a punch of 15 mm in diameter, and its physical properties were measured as shown in Table 1.

(Examples 2 to 10) The formulations and physical properties of samples that were operated in the same manner as in Example 1 except that the monomer formulations were different were as shown in Table 1.

(Examples 11 to 15) The same procedure as in Example 1 was carried out except that the monomer composition was different,
Furthermore, the punching strength and elongation rate were measured. The results are shown in Table 1.

The measurement methods and units for each physical property in Table 1 are as follows.

Kei Kuramoto・Measurement temperature: 20℃ ・Unit: % ・Calculation formula Equilibrium water-containing film weight = W1 Dry film weight = W2 When the following equation is taken, Jj111 loss・Measurement temperature: 35℃ ・Measuring instrument Kaken type film oxygen permeability (manufactured by Rika Seiki Kogyo Co., Ltd.).

Puncture load/Measurement temperature: Room temperature/Unit: 2g -Measurement method: Using an Instron-type compression tester, a pressure needle with a diameter of 1/16 inch is applied to the center of the film in a water-containing state, and the load at break is measured. did.

Elongation rate/Measurement temperature: Room temperature/Unit: % - Same as measuring device thrust wave load (measured at the same time). Calculate the amount of elongation as a percentage before breaking.

(Comparative Example) A soft contact lens (trade name: "Sofina" Rifky Contact Lens Institute type) containing butyl methacrylate and butyl acrylate as main components was measured in the same manner as in the example. Appearance: transparent, water content: 70. 28, oxygen permeability coefficient: 30°0 (thickness: 0.2011), punching strength: 232, elongation: 37, strength index: 20.

It can be seen that the contact lens material of the present invention exhibits extremely high oxygen permeability.

〔Effect of the invention〕

The contact lens material of the present invention has good transparency, excellent oxygen permeability, and high strength, so it can be suitably used as a contact lens material.

Claims (1)

[Claims] Formula (I): A copolymer whose main components are 60 to 90 parts by weight of a monomer represented by formula (I) ▲ ▲ Numerical formula, chemical formula, table, etc. ▼ and 5 to 40 parts by weight of a hydrophilic monomer. A soft contact lens material with a water content of 10% or less, which is made of a combination of materials.