JPH0120407B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel contact lens, and particularly to a hard contact lens which is made mainly of polytriorganovinylsilane, has a high oxygen permeability, and is easy to handle. (Prior art) Generally, the conditions necessary for contact lenses are that they do not interfere with the metabolic function of the cornea;
It has excellent vision correction ability and good transparency, does not damage the cornea, is not easily stained by ingredients in tear fluid, has an optimal lens design and moves well on the cornea, and is made of a material that does not stick to the cornea. It is easy to handle, and is difficult to damage. However, currently commercially available contact lenses, hard contact lenses that are smaller than the corneal diameter and made of a harder material, and soft contact lenses that are larger than the corneal diameter and made of a softer material, both satisfy all of these requirements. It's not a thing. In other words, as a hard contact lens, for example, polymethyl methacrylate (hereinafter referred to as
PMMA is known as a material, but since PMMA has extremely low oxygen permeability (0.005×10 ^-9 cm ³ (STP) cm/cm ³ .sec.cmHg),
This prevents the cornea, which is an avascular tissue, from breathing air, limiting the amount of time it can be worn. To compensate for this drawback, conventional methods have been used to make the base curve of contact lenses as large as possible to make them easier to move on the cornea and promote the exchange of oxygen-containing lachrymal fluid. Moreover, since the lenses move easily, they tend to fall off due to strong blinking, and the lenses hit the upper and lower eyelids, causing other problems such as poor wearing comfort. Therefore, it has been proposed to improve the oxygen permeability of PMMA by copolymerizing it with various silicone compounds (see JP-A-50-87184 and JP-A-54-55455).
However, this lens does not have enough oxygen permeability to supply all the oxygen necessary to the cornea through the lens, and the problem remains unresolved. On the other hand, this contact lens is poly-
2-Hydroxyethyl methacrylate (hereinafter
Water-containing, gel-type contact lenses made from PHEMA (PHEMA) and soft contact lenses made from a non-hydrous elastic material made from silicone rubber are also known. However, since this PHEMA lens is made of soft material, its vision correction ability is inferior to that of PMMA lenses.
Silicone rubber lenses have the disadvantage that they are easily damaged, and because they are a hydrogel, there are problems with staining with tear fluid and drug uptake in cleaning solutions, and the oxygen permeability is not always as high as the cornea requires. Although it has a high oxygen permeability, it is difficult to process precisely because it is an elastic body, and it has the disadvantage that components in tear fluid accumulate inside the lens. (Structure of the Invention) The present invention relates to a contact lens that solves such disadvantages, and is based on the formula [Here, R ¹ , R ² , and R ³ are monovalent hydrocarbon groups having 1 to 6 carbon atoms (except when R ¹ , R 2 , and R ³ are all methyl groups at the same time), and n is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n is a monovalent hydrocarbon group having 1 to 6 carbon atoms (except when R 1 , R ² , and R 3 are all methyl groups), It is characterized by being formed by molding a polymer or copolymer whose main material is polytriorganovinylsilane or a mixture or copolymer of polytriorganovinylsilane and polytrimethylvinylsilane represented by [positive number]. be. To explain this, the present inventors have studied various contact lenses that can solve the above-mentioned disadvantages, and have developed the formula (m is a positive number of 2000 or more) Molded from a polymer based on polytrimethylvinylsilane with a molecular weight of 200,000 or more, it has high mechanical strength, excellent workability, and long-lasting properties. We have discovered that it is possible to obtain contact lenses that can be worn for hours (Tokugan Sho).
59-81526), as a result of further research on this, it was found that this polytrimethylvinylsilane can be converted into polytriorganovinylsilane represented by the above formula (1), and this polytriorganovinylsilane can be expressed as the above formula (2). The present invention was completed by confirming that as the number of carbon atoms in the R group increases compared to polytrimethylvinylsilane represented by the formula, the thermal softening temperature decreases while maintaining oxygen permeability, making thermoforming easier. The polymer used as a material for forming the contact lens of the present invention is mainly composed of polytriorganovinylsilane represented by the above formula (1), and R ¹ in this formula (1), R ² and R ³ are preferably a methyl group, ethyl group, propyl group, butyl group, or phenyl group. This polytriorganovinylsilane has the formula corresponding to this polymer. By adding n-butyllithium as a catalyst to the polytriorganovinylsilane shown in
It is obtained by anionic polymerization at a temperature around 70°C under an inert gas atmosphere for 20 to 50 hours.
If the molecular weight is low, the molded product will have weak mechanical strength and it will be difficult to perform precise machining for contact lenses. It is better to take it as a fact. The high molecular weight polytriorganovinylsilane thus obtained can be thermoformed, and the molded product has excellent transparency and processability, and is useful as a contact lens with high mechanical strength. In addition, the oxygen permeability of this molded product is 4.5 for the molded product made from polytrimethylvinylsilane shown in formula (2) above.
×10 ^-9 cm ³ (STP) cm/cm ² seconds cmHg, whereas in the above formula (1) where R ¹ , R ² and R ³ are dimethyl/ethyl groups, it is 2.5 × 10 ^{- 9} cm ³ (STP)・cm/
cm ²・sec・cmHg, and R ¹ , R ² , and R ³ are dimethyl-
The n-propyl group is 1.8×10 ^-9 cm ³ (STP).
cm/ ^cm2・sec・cmHg, providing contact lenses with high oxygen permeability. In order to manufacture contact lenses from this polytriorganovinylsilane polymer, this polymer is
The polymer can be heated to a temperature in the range of 180 to 340°C and molded into a plate, block, cylinder, or other desired shape, or the polymer can be dissolved in a suitable solvent and cast into a mold to create the desired shape. After being formed into a desired shape, machining such as cutting and polishing may be performed as necessary. The contact lens thus obtained may be used as it is, but it may also be treated with low-temperature plasma to make its surface more hydrophilic. Hydrophilic monomers such as ethyl methacrylate may be polymerized and laminated to make them hydrophilic. In addition, although the above mentioned the use of polytriorganovinylsilane alone, this polytriorganovinylsilane is used in the above formula (1).
It may be a mixture of different R ¹ , R ² , and R ³ groups, and this gives the advantage that the thermal softening temperature can be adjusted by combining various R groups.
It may also be used in combination with polytrimethylvinylsilane. For this combination, polytriorganovinylsilane may be used as a mixture with polytrimethylvinylsilane, but it may also be used as a copolymer of both, and in this case, the blending ratio of both is polytrimethylvinylsilane to polytriorganovinylsilane. The amount of vinyl silane is 1:0.01~
The ratio may be in the range of 0.01:1, and this allows adjustment of the thermal softening point as well as the oxygen permeability. This polytriorganovinylsilane is a copolymer with styrene or methyl methacrylate,
As a copolymer with other organosiloxanes,
Furthermore, it may be used as a mixture with polymethyl methacrylate, which also allows adjustment of the thermal softening point and oxygen permeability. Next, examples of the present invention will be given. Example 1 Formula Add 0.1ml of n-butyllithium hexane solution with a concentration of 15% to 50g of dimethylethylvinylsilane shown in
and heated at 60℃ under anhydrous conditions in a nitrogen gas atmosphere.
After anionic polymerization for 24 hours, the resulting polymer was dissolved in 500 ml of cyclohexane, precipitated in excess methanol, purified, and dried to obtain 43 g of polydimethylethylvinylsilane. When measured using a permeation chromatograph using a column A-80M manufactured by Showa Denko, it was 350,000 in terms of polystyrene. Next, this polymer was dissolved in toluene to make a 20% by weight toluene solution, which was poured into a mold while being filtered. When the toluene was evaporated, a colorless and transparent film was obtained. This film was then machined. A disk with a diameter of 18 mm and a thickness of 0.2 mm,
When its oxygen permeability coefficient was measured using an electrode method in distilled water at 25°C, it was 3.2 × 10 ^-9 cm ³
(STP)・cm/ ^cm2・sec・cmHg, which also has a visible light transmittance of 98% at wavelengths of 380 mm to 780 mm.
The refractive index was 1.50 and had good visual acuity correction ability. Therefore, this film has a base cup of 7.80 mm, a thickness of 0.15 mm at the center of the lens, and a size of
When cut to 8.8 mm and polished, this product had good cutting and polishing properties, and the molded product thus obtained became useful as a contact lens. The polymer obtained above was thermoformed at 250°C to form a button-shaped block, then cut,
After polishing, a contact lens with excellent oxygen permeability and good vision correction ability was obtained. Example 2 Formula Using 50g of dimethyl(n-propyl)vinylsilane shown in Example 1, polydimethyl(n-propyl)vinylsilane having a molecular weight of 180,000 was prepared by the same treatment as in Example 1. When we measured the physical properties of a 0.2 mm thick film made from
10 ^-9 cm ³ (STP) cm/cm ² seconds cmHg, visible light transmittance of 99% or more, and refractive index of 1.51.
Next, this polymer was thermoformed at 230°C to make a button-shaped block, which was then cut and polished, resulting in a contact lens with excellent oxygen permeability and visible light permeability. Example 3 Formula Using 50 g of dimethylphenylvinylsilane represented by the formula, 47 g of polydimethylphenylvinylsilane having a molecular weight of 760,000 was obtained by processing in the same manner as in Example 1. Next, this polymer was treated in the same manner as in Example 1 to make a film with a thickness of 0.2 mm, and the physical properties of this film were measured, and the oxygen permeability coefficient was 0.9 ×
It exhibited physical properties of 10 ^-9 cm ³ (STP) cm/cm ² seconds cmHg, visible light transmittance of 98% or more, and refractive index of 1.58. Next, this polymer was thermoformed at 200°C to create a button-shaped block, which was then cut and polished, resulting in a contact lens with excellent oxygen permeability and visible light permeability. Example 4 25g of dimethylethylvinylsilane used in Example 1 and formula 25 g of trimethylvinylsilane represented by: were mixed and treated in the same manner as in Example 1 to produce 44 g of a copolymer of dimethylethylvinylsilane and trimethylvinylsilane having a molecular weight of 280,000. This copolymer can be thermoformed at 265℃,
The 0.2 mm thick film obtained from this has an oxygen permeability coefficient of 4.3 × 10 ^-9 cm ³ (STP) cm/cm ² seconds cm
Hg showed physical properties of visible light transmittance of over 98% and refractive index of 1.49, and contact lenses made from it showed excellent oxygen permeability and visible light transmittance. Example 5 500 ml of dehydrated and purified cyclohexane and 0.1 ml of n-butyllithium hexane solution with a concentration of 15% were added to 50 g of dimethylethylvinylsilane, and anionic polymerization was carried out at 60° C. for 24 hours under anhydrous conditions in a nitrogen gas atmosphere to form a polymer. 20g of dimethylsiloxane trimer was added dropwise to the polymer over 30 minutes, then heated to 60°C.
500 ml of anhydrous tetrahydrofuran was added to this reaction solution, and the reaction was further carried out under reflux for 4 hours, and then poured into excess methanol to precipitate, purified, and dried. Dimethylethylvinylsilane- 59 g of a dimethylsiloxane block copolymer was obtained. The molecular weight of this copolymer is 780,000, and a 0.2 mm thick film made from this polymer has an oxygen permeability coefficient of 8.5 x 10 ^-9 cm ³ (STP) cm/cm ² seconds cm
With Hg, we were able to create a contact lens with good machinability and polishability, and good vision correction ability. Examples 6-8 Two types of various triorganovinylsilanes shown in Table 1 were mixed at the compounding ratio (wt%) shown in Table 1, and this was treated in the same manner as in Example 1 to form a copolymer. When we investigated the thermoforming temperature of this copolymer and measured the oxygen permeability coefficient of a 0.2 mm thick film made from this copolymer, we obtained the results listed in Table 1. Contact lenses obtained by cutting and polishing button-shaped blocks obtained by thermoforming this copolymer at the relevant temperature exhibited excellent oxygen permeability and visible light transmittance.

[Table] Example 9 500 ml of dehydrated and purified benzene and 0.1 ml of n-butyllithium hexane solution with a concentration of 15% were added to 50 g of dimethylethylvinylsilane, and anionic polymerization was carried out at 60°C for 24 hours in an anhydrous state under a nitrogen gas atmosphere. Styrene monomer is added to the purified polymer.
A mixture of 10 g diluted with 30 ml of benzene was added dropwise over 30 minutes, reacted at 60°C for 2 hours, poured into excess methanol to precipitate, purified and dried, resulting in dimethylethylvinylsilane-styrene. 56 g of block copolymer was obtained. The molecular weight distribution of this copolymer is monodisperse, the molecular weight is 490,000, and the thickness of the polymer is 0.2 mm.
The film has an oxygen permeability coefficient of 2.0×10 ^-9 cm ³
(STP)・cm/cm ²・sec・cmHg The contact lens had good machinability and polishability, and had good vision correction ability.

Claims (1)

[Claims] 1 formula [Here, R ¹ , R ² , and R ³ are monovalent hydrocarbon groups having 1 to 6 carbon atoms (except when R ¹ , R 2 , and R ³ are all methyl groups at the same time), and n is a monovalent hydrocarbon group having 1 to 6 carbon atoms, and n is a monovalent hydrocarbon group having 1 to 6 carbon atoms (except when R 1 , R ² , and R 3 are all methyl groups), A contact lens formed by molding a polymer or copolymer whose main material is a polytriorganovinylsilane represented by a positive number] or a mixture or copolymer of this polytriorganovinylsilane and polytrimethylvinylsilane. . 2. The contact lens according to claim 1, wherein the polytriorganovinylsilane and polytrimethylvinylsilane have a molecular weight of 100,000 or more. 3 The mixture or copolymer is polytriorganovinylsilane and polytrimethylvinylsilane 1:
A contact lens according to claim 1, which is a weight ratio formulation of 0.01 to 0.01:1. 4 R ¹ , R ² , and R ³ are selected from methyl, ethyl, propyl, and phenyl groups (excluding those in which R ¹ , R ² , and R ³ are all methyl groups) A contact lens according to claim 1.