JPH09230104A - Lens for eye and its hydrophilic treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact lens having an extrahydrophilic surface. SOLUTION: The surface of a contact lens is coated with a silicone layer containing a semiconductor photocatalyst. When the photocatalyst is excited with light, org. groups bonded to silicon atoms in the silicone molecules are replaced by hydroxyl groups to make the surface of the contact lens extrahydrophilic. Since the extrahydrophilic surface has qood wettability with tear, the fitting feeling of the contact lens is improved. The extrahydrophilicity of the surface is maintained as long as it is irradiated with light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic lens such as a contact lens or an intraocular lens, and more particularly to a technique for making the surface of the ophthalmic lens hydrophilic.

[0002]

2. Description of the Related Art Hard contact lenses made of oxygen-permeable materials such as siloxanyl methacrylate and fluoromethacrylate, and non-hydrous soft contact lenses made of silicone rubber containing polydimethylsiloxane as a main component Since it has high water repellency and repels tear fluid, it has a drawback that the wearing feeling is poor and the eyesight becomes unstable due to cloudiness.

[0003]

Therefore, various techniques for making the surface of the contact lens hydrophilic have been proposed. As a hydrophilic treatment method of the prior art, discharge treatment, acid or base treatment, treatment with a wetting solution, plasma polymerization, etc. are known, but the hydrophilicity is not sufficient or the durability of the surface treatment layer is low. It is not sufficient and hydrophilicity is lost early.

It is an object of the present invention to provide an ophthalmic lens with a highly hydrophilized surface. Another object of the present invention is to provide an ophthalmic lens having a hydrophilic surface with excellent durability. Another object of the present invention is to provide a method for hydrophilizing an ophthalmic lens which has excellent durability and can realize a highly hydrophilized surface.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have discovered that when a photocatalyst is blended with silicone and the photocatalyst is photoexcited, the surface of the silicone is highly hydrophilized.

The invention is based on such a discovery, and according to the invention, the surface of an ophthalmic lens is coated with a transparent layer containing a semiconductor photocatalyst. Preferably, the photocatalyst-containing layer is formed of silicone in which photocatalyst particles are uniformly dispersed. As the photocatalyst, it is preferable to use titania, preferably rutile type titania. The photocatalyst-containing layer is obtained by applying a coating composition containing particles of a semiconductor photocatalyst and a coating film-forming element made of uncured or partially cured silicone or a precursor of a silicone to the surface of an ophthalmic lens to form a coating film. It can be formed by curing the forming element. When the photocatalyst is photoexcited, a silicone derivative in which an organic group bonded to a silicon atom of a silicone molecule is at least partially substituted with a hydroxyl group is formed on the surface of the photocatalyst-containing layer, and the surface of the photocatalyst-containing layer has a water wetting angle ( The contact angle is about 10 ° or less, preferably about 5 ° or less, and more preferably about 0 °.

As described above, the surface of the ophthalmic lens is made superhydrophilic, so that the tear fluid is well absorbed and the feeling of wearing is improved. Further, since lipids and proteins do not easily adhere to the superhydrophilized surface, the lens does not fog and cleaning is easy. Since the photocatalyst is photoexcited by sunlight or indoor illumination light that enters the eye while the lens is worn, the superhydrophilicity of the surface is maintained forever. Silicone is gas permeable and therefore suitable for coating oxygen permeable contact lenses. Since silicone is also excellent in weather resistance, it can withstand boiling disinfection and dryness.
The above features and advantages of the present invention, as well as other features and advantages, will be apparent from the description of the embodiments below.

[0008]

The present invention applies to contact lenses and intraocular lenses. The surface of the ophthalmic lens is covered with a transparent layer containing a semiconductor photocatalyst.

The most preferable photocatalyst is titania (TiO ₂ ). Titania is harmless and chemically stable. Further, titania has a high band gap energy, and thus requires ultraviolet light for photoexcitation and does not absorb visible light in the process of photoexcitation, so that coloring by a complementary color component does not occur. It also absorbs UV rays that are harmful to the eyes. Both anatase titania and rutile titania can be used. The advantage of the anatase type titania is that a sol in which very fine particles are dispersed can be easily obtained on the market, and a very thin surface layer can be easily formed. However, rutile-type titania has a lower conduction band level and a weaker photooxidation effect, and thus has an advantage of less influence on the cornea. Other photocatalysts which can be used include metal oxides such as _{ZnO, SnO 2, SrTiO 3,} WO 3, Bi 2 O 3, Fe 2 O 3.

The thickness of the photocatalyst-containing layer is preferably 0.2 μm or less, more preferably 0.1 μm or less. 0.2
When the film thickness is not more than μm, color development due to light interference can be prevented. Further, the thinner the photocatalyst containing layer, the more the transparency of the photocatalyst containing layer can be secured. The superhydrophilization phenomenon of the silicone surface by the photocatalyst can be realized by a photocatalytic action weaker than the photooxidation action by the photocatalyst. Therefore, in order to prevent the effect of the photocatalyst on the cornea, it is preferable to weaken the photooxidation action of the photocatalyst. For this purpose, the thickness of the photocatalyst containing layer is preferably 0.1 μm or less. Alternatively, the photooxidation activity of the photocatalyst is suppressed by adding one or more of alkali metal, alkaline earth metal, alumina, silica, zirconia, antimony oxide, amorphous titania, and hydrous titania to the photocatalyst containing layer. be able to.

The photocatalyst-containing layer can be formed by using a coating composition obtained by dispersing photocatalyst particles in a film-forming element made of uncured or partially cured silicone or a precursor of silicone. it can.

As the film forming element, methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane; ethyltrichlorosilane, ethyltribromosilane, Ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltrit-butoxysilane; n-propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane,
n-propyltriethoxysilane, n-propyltriisopropoxysilane, n-propyltri-t-butoxysilane; n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n
-Hexyltriethoxysilane, n-hexyltriisopropoxysilane, n-hexyltrit-butoxysilane; n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n -Decyltriisopropoxysilane, n-decyltri-t-butoxysilane; n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane; phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltrisilane -Butoxysilane; tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane; dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane; diphenyldisilane Chlorosilane, diphenyldibromosilane, diphenyldimethoxysilane,
Diphenyldiethoxysilane; phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane; trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane, tri-t -Butoxyhydrosilane; vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane,
Vinyltri-t-butoxysilane; trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltrit-butoxysilane; γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxy Silane, γ-glycidoxypropyltri-t-butoxysilane; γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryl Riloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltri-t-butoxysilane; γ-aminopropylmethyldimethoxysilane, γ- Aminopropylmethyldiethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltri-t-butoxysilane; γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane , Γ-mercaptopropyltrimethoxysilane, γ-
Mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane; β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β-
(3,4-Epoxycyclohexyl) ethyltriethoxysilane; and their partial hydrolysates; and mixtures thereof can be used. In order to secure sufficient flexibility of the ophthalmic lens, it is preferable to use a two-dimensional crosslinked siloxane and a three-dimensional crosslinked siloxane.

This coating composition is applied to the surface of an ophthalmic lens by spray coating, dip coating, spin coating, etc., and after curing the film-forming element, the photocatalyst is photoexcited to bond to the silicon atom of the silicone molecule. The formed organic groups are replaced with hydroxyl groups by the action of the photocatalyst, and the surface of the photocatalyst-containing layer is made superhydrophilic.

Photoexcitation of the photocatalyst can be performed by various light sources. In the case of a photocatalyst having an excitation wavelength in the ultraviolet region such as titania, a germicidal lamp, a black light blue fluorescent lamp, a mercury lamp, a metal halide lamp, a xenon lamp, and other ultraviolet light sources can be used. You may use sunlight. Once the surface of the photocatalyst containing layer is highly hydrophilized, the superhydrophilicity of the surface continues in the dark and at night. When wearing the lens, the photocatalyst is photo-excited by the sunlight entering the eye,
The superhydrophilicity of the surface of the photocatalyst containing layer is maintained forever. The weak ultraviolet rays contained in fluorescent lamps and incandescent lamps are sufficient to maintain superhydrophilicity.

[0015]

EXAMPLES Example 1 A 10 cm square aluminum substrate was used as a base material.
In order to smooth the surface of the substrate, it was previously coated with a silicone layer. For this reason, liquid A (silica sol) and liquid B (trimethoxymethylsilane) of the coating composition "GLASCA" of Japan Synthetic Rubber should be adjusted so that the weight ratio of silica to trimethoxymethylsilane is 3: 1. After mixing, the mixed solution was applied to an aluminum substrate and cured at a temperature of 150 ° C. to obtain an aluminum substrate (# 1 sample) coated with a silicone base coat having a film thickness of 3 μm. Next, anatase-type titania sol (NISSAN CHEMICAL, TA-15, average crystallite diameter 12 nm)
And the above-mentioned "Glasca" solution A were mixed and diluted with ethanol, and then the "Glasca" solution B was added to prepare a titania-containing coating composition. The composition of the coating composition was 3 parts by weight of silica, 1 part by weight of trimethoxymethylsilane, and 4 parts by weight of titania. This paint composition #
It was applied on the surface of one sample and cured at a temperature of 150 ° C. to form a top coat in which anatase-type titania particles were dispersed in a silicone coating film, and a # 2 sample was obtained. Next, the # 2 sample was irradiated with ultraviolet rays at a illuminance of 0.5 mW / cm ² for 5 consecutive days using a 20 W black light blue (BLB) fluorescent lamp (Sankyo Denki, FL20BLB) to obtain a # 3 sample. The contact angle of the surface of this sample with water is measured by a contact angle measuring device (ERMA, type GI-100
0, the detection limit at the low angle side was 3 °), and the contact angle reading was less than 3 °. The contact angle of the # 2 sample before ultraviolet irradiation was measured and was found to be 70 °. When the contact angle of the # 1 sample was measured, it was 90 °. Furthermore, # 1
When the contact angle was measured by irradiating the sample with ultraviolet rays for 5 days under the same conditions as the sample # 2, the contact angle was 85 °. From the above, it has been discovered that, despite the fact that silicone is inherently hydrophobic, when a photocatalyst is contained and the photocatalyst is excited by ultraviolet irradiation, it is highly hydrophilized.

# 2 sample was 22.8 mW / cm ² using a mercury lamp.
The sample was irradiated with ultraviolet light for 2 hours at the ultraviolet illuminance described above to obtain a # 4 sample. Raman spectroscopy was performed on the # 2 sample before irradiation and the # 4 sample after irradiation. For comparison, the # 1 sample was irradiated with ultraviolet light under the same conditions, and the sample before and after the irradiation was subjected to Raman spectroscopic analysis. The Raman spectrum is shown in the graph of FIG. Since the Raman spectra before and after irradiation of the # 1 sample were the same,
This is indicated by curve # 1 in the graph of FIG. Referring to the graph of FIG. 1, in the Raman spectrum of the # 2 sample, the wave number
At the position of 2910 cm ^-1 , a large peak of symmetric stretching of the CH bond of the sp ³ hybrid orbital is observed, and at the position of wave number 2970 cm ^-1 , the sp ³
A large peak of CH bond antisymmetric stretching of the hybrid orbital is observed. Therefore, it is concluded that the CH bond exists in the # 2 sample. In the spectrum of the # 4 sample, the wave number 29
Not observed peaks on any of the positions of the position and 2970cm ^-1 of 10 cm ^-1. Instead, a wide O--H bond symmetrical expansion and contraction having a peak at a wave number of 3200 cm ^-1 is observed. Therefore, it is concluded that the C—H bond does not exist in the # 4 sample, and the O—H bond exists instead. On the other hand, in the Raman spectrum of the # 1 sample, before and after the irradiation, the position of the wave number 2910 cm ^{-1 was at} the position of the sp ³ hybrid orbital C
A large peak of -H bond symmetrical expansion and contraction was observed, and 2970 cm ^-1
A large peak of C—H bond antisymmetric stretching of sp ³ hybrid orbital is observed at the position of. Therefore, it is confirmed that a CH bond exists in the # 1 sample. From the above, it is considered that when ultraviolet rays are irradiated on silicone containing a photocatalyst, a silicone derivative in which an organic group bonded to a silicon atom of a silicone molecule is substituted with a hydroxyl group by photocatalysis is formed on the surface. .

Example 2 Anatase type titania sol (TA-15) was mixed with the above-mentioned "Glasca" solution B (trimethoxymethylsilane) so that the weight ratio of titania and trimethoxymethylsilane was 1: 1. The mixed solution is applied to a polymethylmethacrylate (PMMA) plate and cured at a temperature of 110 ° C to a film thickness of 0.1.
A sample coated with a 1 μm titania-containing silicone layer was obtained. Using a BLB fluorescent lamp (FL20BLB) for this sample,
Irradiate with UV light at an illuminance of W / cm ² for 1 week, and measure the contact angle of water on the surface of this sample with a contact angle measuring instrument (Kyowa Interface Science Co., Ltd., Model CA-X150, low angle side detection limit 1 °) When measured, the contact angle reading was 0 °. For comparison, when the PMMA plate without the titania-containing silicone coating was irradiated with ultraviolet rays under the same conditions and the contact angle with water was measured, the contact angle was 70.
Was ゜.

[0018]

EFFECTS OF THE INVENTION According to the present invention, the surface of the contact lens is made superhydrophilic, so that the tear fluid is well absorbed and the wearing feeling of the contact lens is remarkably improved. Lipids and proteins do not easily adhere to the superhydrophilized surface, so that the lens can be easily washed without clouding. Since the photocatalyst is photoexcited as long as it is exposed to light, the superhydrophilicity of the surface of the contact lens is maintained semipermanently.

[Brief description of drawings]

FIG. 1 shows a Raman spectrum of Example 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location // B29K 83:00 (72) Inventor Makoto Senkuni 2-chome, Nakajima, Kitakyushu, Fukuoka Prefecture No. 1 in Totoki Co., Ltd. (72) Inventor Toshiya Watanabe 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture (72) In Tokoki Co., Ltd. (72) Atsushi Kitamura Kokurakita-ku, Kitakyushu, Fukuoka Nakajima 2-1-1 No. 1 Totoki Equipment Co., Ltd.

Claims (6)

[Claims] 1. A surface of an ophthalmic lens is coated with a transparent layer containing a semiconductor photocatalyst, and the surface of the layer is hydrophilic at about 10 ° or less in terms of contact angle with water in response to photoexcitation of the photocatalyst. An ophthalmic lens characterized in that 2. The layer is formed of silicone in which photocatalyst particles are uniformly dispersed, and the surface of the layer is a silicone in which an organic group bonded to a silicon atom of a silicone molecule is at least partially substituted with a hydroxyl group. An ophthalmic lens according to claim 1 formed of a derivative. 3. The ophthalmic lens according to claim 2, wherein the photocatalyst is made of rutile titania. 4. The ophthalmic lens according to claim 1, wherein the thickness of the layer is about 0.2 μm or less. 5. A coating composition comprising particles of a semiconductor photocatalyst and a film-forming element comprising uncured or partially cured silicone or a precursor of a silicone is applied to the surface of an ophthalmic lens, By curing the coating film forming element, a layer in which photocatalyst particles are uniformly dispersed in silicone is formed, and by photoexciting the photocatalyst, an organic group bonded to a silicon atom of a silicone molecule on the surface of the layer is photocatalysted. By at least partially substituting the hydroxyl group by the action of,
A method for hydrophilizing an ophthalmic lens, which comprises hydrophilizing the surface of the layer to a contact angle with water of about 10 ° or less. 6. The hydrophilization treatment of an ophthalmic lens according to claim 5, wherein the photocatalyst is photoexcited until the surface of the layer is converted to a contact angle with water of about 5 ° or less. Method.