JPH11109296A - Ocular lens and its material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an melt moldable ocular lens material capable of yielding an ocular lens having excellent transparency and mechanical strength and good flexibility by using a block copolymer having an arom. vinyl compd. based polymer block and a conjugated diene based polymer block subjected to hydrogenation. SOLUTION: This ocular lens material consists of the block copolymer having at least one piece of the arom. vinyl compd. based polymer block and at least one piece of the conjugated diene based polymer block subjected to hydrogenation of at least one. The arom. vinyl compd. based copolymer block which consists of styrene as the essential component of its structural unit is preferable in increasing the mechanical strength of the ocular lens yielded by the block copolymer. The conjugated diene based polymer block which consists of the hydrogenated polymer of 1,3-butadiene or/and isoprene as the essential component of its structural unit is preferable in increasing the transparency and mechanical strength of the ocular lens yielded by the block copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic lens material which can be melt-molded and which provides an ophthalmic lens having excellent transparency and mechanical strength and good flexibility, and an ophthalmic lens comprising the same. . The ophthalmic lens material of the present invention,
It is useful as a material for soft contact lenses, especially non-hydrous soft contact lenses.

[0002]

2. Description of the Related Art Various soft and hard materials have been proposed as materials for contact lenses and intraocular lenses. As a material for a contact lens or a material for an intraocular lens, a soft material is preferable in terms of biocompatibility and wearing feeling. The soft material includes a water-containing material that is softened by absorbing water and swells, and a non-water-containing material made of an elastomer. Water-containing materials have the disadvantage of poor mechanical strength, and bacteria and molds easily propagate in materials containing water, so disinfection is indispensable when used as contact lenses. . On the other hand, non-water-containing materials have attracted attention as ideal materials because they do not require disinfection and have the above advantages as soft materials.

[0003] Silicon rubber and acrylic rubber are known as materials for non-water-containing contact lenses. Although silicone rubber has the advantage of very high oxygen permeability, its material surface exhibits extremely strong water repellency, and when used as a material for contact lenses, it easily adheres to the cornea and can cause serious eye damage. It has been reported. On the other hand, as an acrylic rubber-based non-water-containing material, Japanese Unexamined Patent Publication No.
No. 7,825, JP-A-1-183623, etc., a copolymer containing butyl acrylate as a main component has been reported. However, contact lenses made of such a material are liable to become cloudy due to adhesion of dirt such as lipids. There is still a point to be improved, for example, the target strength is not satisfactory. Further, a method for producing a contact lens from the above-mentioned materials is to cut a hard copolymer of a monomer mixture containing butylacrylic acid as a main component into a contact lens shape, polish it, and then soften it by an esterification reaction. Yes,
The operation is complicated. Furthermore, since the dimensions change before and after the esterification reaction in the operation, it is difficult to manufacture a contact lens having a desired standard with good accuracy, and the productivity is low.

[0004]

As a method for producing a hydrous contact lens, for example, Japanese Patent Application Laid-Open No. 5-313104 is disclosed.
As described in Japanese Unexamined Patent Application Publication No. 2000-163, a method by melt molding such as injection molding with high productivity is known, but a method by melt molding is not known as a method for producing a non-hydrous soft contact lens. Although thermoplastic elastomers can be melt-molded, many of them are inferior in transparency and give molded products that are not flexible enough.
It was never used as an ophthalmic lens material.

[0005] It is an object of the present invention to provide an ophthalmic lens material which is excellent in transparency and mechanical strength, and which gives an ophthalmic lens having good flexibility. Another object of the present invention is to provide an ophthalmic lens made of the above-mentioned ophthalmic lens material, particularly a soft contact lens, particularly a non-hydrous soft contact lens.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, at least
A block copolymer having one aromatic vinyl compound-based polymer block and at least one hydrogenated conjugated diene-based polymer block is excellent in transparency and mechanical strength, and has good flexibility It has been found that an ophthalmic lens is provided and can be melt-molded, and is excellent as an ophthalmic lens material.

That is, the present invention is an ophthalmic lens material comprising a block copolymer having at least one aromatic vinyl compound-based polymer block and at least one hydrogenated conjugated diene-based polymer block. . Further, the present invention is an ophthalmic lens comprising the above ophthalmic lens material.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The conjugated diene-based polymer block in the block copolymer as the ophthalmic lens material of the present invention comprises 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-
A polymer block having one or more conjugated diene compounds such as butadiene and 1,3-pentadiene as the main structural unit, and part or all of the unsaturated bond portion becomes a saturated bond by hydrogenation. Is what it is.
Among them, those in which the conjugated diene-based polymer block has a hydrogenated polymer of 1,3-butadiene or / and / or isoprene as a main component of the structural unit, the transparency of the ophthalmic lens provided by the block copolymer is given. It is preferably used from the viewpoint of mechanical strength. The content of double bonds in the conjugated diene-based polymer block is preferably 60 mol% or less, and more preferably 0 to 30 mol%, from the viewpoint of the transparency of the ophthalmic lens provided by the block copolymer. More preferred.

The aromatic vinyl compound-based polymer block in the above block copolymer is mainly composed of structural units derived from an aromatic vinyl compound, and may optionally contain a small amount of structural units derived from another unsaturated monomer. Have. As the aromatic vinyl compound constituting the aromatic vinyl compound-based polymer block, styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,
1,3-dimethylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene,
2-ethyl-4-benzylstyrene, 4- (phenylbutyl)
Styrene and the like can be mentioned. As the aromatic vinyl compound-based polymer block, those containing styrene as a main component of the structural unit are preferable because the block copolymer gives the ophthalmic lens excellent mechanical strength.

The weight ratio of the aromatic vinyl compound-based polymer block to the conjugated diene-based polymer block in the above block copolymer is preferably in the range of 10:90 to 50:50, and more preferably in the range of 10:90 to 30:70. The range is more preferred.
Weight ratio of aromatic vinyl compound polymer block is 10%
If the amount is less, the strength of the ophthalmic lens provided by the block copolymer will be low, and if it exceeds 50%, the flexibility of the ophthalmic lens will be poor. The number average molecular weight of the block copolymer is preferably 30,000 to 500,000. When the number average molecular weight is smaller than the above range,
When the mechanical strength of the ophthalmic lens provided by the block copolymer becomes insufficient, and when it exceeds the above range, the moldability becomes insufficient.

The molecular structure of the above block copolymer in the present invention may be any of linear, branched, radial or any combination thereof, but is not limited to one aromatic vinyl compound-based polymer block. (A) and one conjugated diene polymer block (B) are linked linearly (A-
B) A diblock copolymer, and a triblock copolymer in which three polymer blocks are linearly bonded in the order of (ABA) are easy to manufacture, easy to obtain, and have mechanical properties. It is preferable from the point of view.

The above block copolymer can be produced by a known method. For example, it can be produced by preparing a block copolymer by an anionic polymerization method and then hydrogenating it.

The surface of the ophthalmic lens material of the present invention can be made hydrophilic by grafting a hydrophilic monomer to the surface as necessary. Examples of such hydrophilic monomers include (meth) acrylamides such as acrylamide and N, N-dimethylacrylamide; (meth) acrylic acid, hydroxyethyl ester of (meth) acrylic acid,
Hydroxyalkyl (meth) acrylates such as hydroxypropyl ester; N-vinyllactams such as N-vinylpyrrolidone, N-vinylpiperidone and N-vinylcaprolactam; polyalkylene glycol (meth) acrylates such as polyethylene glycol mono (meth) acrylate; -(Meth) acryloyloxyethylphosphocholine and the like.

The ophthalmic lens of the present invention can be obtained by melt-molding the ophthalmic lens material comprising the above block copolymer. The molding method is not particularly limited, but an injection molding method or a compression molding method is preferably used. In molding, the above block copolymer may be molded as it is, but if necessary, a heat stabilizer, an antioxidant, a light stabilizer, a coloring agent, an antistatic agent, a lubricant, a release agent, etc. Agents may be added.

[0015]

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, the tensile strength was measured by the following method.

[Tensile strength] A tensile test was performed using an autograph (model IM-100) manufactured by Shimadzu Corporation. Both ends of the test piece were fixed to grips of a tester, and the test piece was pulled in distilled water at 25 ° C. at a rate of 50 mm / min until the test piece broke, and the stress at break was defined as tensile strength.

Example 1 A hydrogenated product of a triblock copolymer consisting of a styrene polymer block / isoprene polymer block / styrene polymer block containing styrene at a ratio of 30% by weight (Septon 2 manufactured by Kuraray Co., Ltd.)
002) was heated and melted, and formed into a contact lens by injection molding. By this method, a large number of contact lenses of the same standard could be manufactured in a short time. The contact lens thus obtained is excellent in transparency, has good resilience, such as immediately returning to the original state even when the lens is folded and released, and has good flexibility as a soft contact lens. Had. The results of the tensile strength test of the obtained contact lens are shown in Table 1, and the contact lens had excellent mechanical strength.

Example 2 A hydrogenated product of a triblock copolymer consisting of a styrene polymer block / isoprene polymer block / styrene polymer block containing styrene at a ratio of 13% by weight (Septon 2 manufactured by Kuraray Co., Ltd.)
063), a contact lens was prepared in the same manner as in Example 1. The contact lens obtained in this way is excellent in transparency, has good resilience, such as restoring to the original state immediately after folding the lens and releasing it, and has good flexibility as a soft contact lens I was The results of the tensile strength test of the obtained contact lens are shown in Table 1, and the contact lens had excellent mechanical strength.

Example 3 A hydrogenated product of a triblock copolymer consisting of a styrene polymer block / isoprene polymer block / styrene polymer block containing styrene at a ratio of 20% by weight (Hibler VS manufactured by Kuraray Co., Ltd.) About -3), the same operation as in Example 1 was performed to prepare a contact lens. The contact lens obtained in this way is excellent in transparency, has good resilience, such as restoring to the original state immediately after folding the lens and releasing it, and has good flexibility as a soft contact lens I was The results of the tensile strength test of the obtained contact lens are shown in Table 1, and the contact lens had excellent mechanical strength.

[Comparative Example 1] An acrylic rubber-based non-hydrated soft contact lens was prepared as described in JP-A-1-183623.
Prepared according to the method described in JP-A No. The obtained contact lens is excellent in transparency, has good resilience, such as being immediately restored to its original state even when the lens is folded and released, and has good flexibility as a soft contact lens. Was. However, since dimensions change before and after the esterification reaction, it has been difficult to prepare a contact lens having a desired specification. Table 1 shows the results of the tensile strength test of the obtained contact lenses.

[0021]

[Table 1]

As is clear from the above, the non-hydrous soft contact lens obtained from the ophthalmic lens material of the present invention has excellent transparency and mechanical strength, and has appropriate flexibility. . Such excellent properties are achieved by the block copolymer having at least one aromatic vinyl compound-based polymer block and at least one hydrogenated conjugated diene-based polymer block which is the ophthalmic lens material of the present invention. It is derived from.

[0023]

According to the present invention, there is provided a melt-moldable ophthalmic lens material which provides an ophthalmic lens having excellent transparency and mechanical strength and having good flexibility. By using such a material, an ophthalmic lens having excellent performance can be easily manufactured by means of extremely high productivity such as melt molding.

Claims (4)

[Claims] 1. An ophthalmic lens material comprising a block copolymer having at least one aromatic vinyl compound-based polymer block and at least one hydrogenated conjugated diene-based polymer block. 2. An ophthalmic lens comprising the ophthalmic lens material according to claim 1. 3. A soft contact lens.
The ophthalmic lens as described. 4. The ophthalmic lens according to claim 2, which is a non-hydrous soft contact lens.