MEDICAL DEVICE

Abstract

A medical device including a silicone hydrogel which is less likely to harden due to drying, and which is less likely to cause stimulation at a site in contact with a human body, is disclosed. The medical device includes a silicone hydrogel satisfying the following conditions: (1) the water content in hydrous state is within the range of 10% by mass to 70% by mass; (2) the content of silicon atoms with respect to the total mass in dry state is within the range of 8% by mass to 30% by mass; and (3) the tensile elastic modulus in dry state is within the range of 0.1 MPa to 3.5 MPa.

Claims

1. A medical device comprising a silicone hydrogel satisfying the following conditions: (1) a water content in hydrous state which is within the range of 10% by mass to 70% by mass; (2) a content of silicon atoms with respect to the total mass in dry state which is within the range of 8% by mass to 30% by mass; and (3) a tensile elastic modulus in dry state which is within the range of 0.1 MPa to 3.5 MPa.

2. The medical device according to claim 1, wherein the tensile elastic modulus is within the range of 0.1 MPa to 1.5 MPa.

3. The medical device according to claim 1, comprising a silicone hydrogel having a dry elastic modulus ratio of 0.1 to 10, wherein the dry elastic modulus ratio is represented by the following Equation 1:
dry elastic modulus ratio=the tensile elastic modulus in dry state/tensile elastic modulus in hydrous state. (1)

4. The medical device according to claim 1, wherein the silicone hydrogel has a zero-stress period of 0.1 second to 2 seconds in hydrous state, wherein the zero-stress period means a length of time during tensile stress measurement in which an operation of drawing a test piece having a width of 5 mm and a thickness within the range of 0.05 mm to 0.2 mm held at an inter-supporting-point distance of 5 mm, using a load cell with a maximum load of 2 kg at a rate of 100 mm/minute, until the inter-supporting-point distance becomes 10 mm, and then reducing the inter-supporting-point distance to 5 mm at the same rate, is repeated three times while obtaining measured values at 20-millisecond intervals, the length of time being a length of time from the time point when the stress becomes zero during the second reduction of the inter-supporting-point distance to 5 mm to the time point when the stress becomes non-zero after starting the third drawing, wherein zero stress means a state with a measured value within the range of 0.05 gf to 0.05 gf.

5. The medical device according to claim 1, wherein the silicone hydrogel has a tensile elongation at break within the range of 200% to 1000% in hydrous state.

6. The medical device according to claim 3, wherein the silicone hydrogel has a tensile elastic modulus within the range of 0.1 MPa to 1.5 MPa in hydrous state.

7. The medical device according to claim 1, wherein the silicone hydrogel comprises a repeat unit (A) derived from a monomer represented by General Formula (I): ##STR00013## wherein, in General Formula (I), R.sup.a represents hydrogen or a methyl group; R.sup.b represents a hydrogen atom, a sulfonic group, a phosphate group, or an organic group having from 1 to 15 carbon atoms; and n represents an integer within the range of 1 to 40.

8. The medical device according to claim 7, comprising the repeat unit (A) derived from a monomer represented by General Formula (I) in an amount within the range of 5% by mass to 50% by mass with respect to the total mass of the silicone hydrogel in dry state.

9. The medical device according to claim 1, wherein the silicone hydrogel contains a repeat unit (B) derived from a monofunctional linear silicone monomer.

10. The medical device according to claim 9, comprising the repeat unit (B) derived from a monofunctional linear silicone monomer in an amount within the range of 20% by mass to 70% by mass with respect to the total mass of the silicone hydrogel in dry state.

11. The medical device according to claim 1, wherein the silicone hydrogel contains a repeat unit (C) derived from a monomer containing an amide structure.

12. The medical device according to claim 11, comprising the repeat unit (C) derived from a monomer containing an amide structure, in an amount within the range of 5% by mass to 50% by mass with respect to the total mass of the silicone hydrogel in dry state.

13. The medical device according to claim 11, wherein the repeat unit (C) derived from a monomer containing an amide structure has a glass transition temperature of not more than 20 C. in a state of a homopolymer.

14. The medical device according to claim 1, which is any one selected from the group consisting of ophthalmic lenses, endoscopes, catheters, infusion tubes, gas transfer tubes, stents, sheaths, cuffs, tube connectors, access ports, drainage bags, blood circuits, wound dressings, and drug carriers.

15. The medical device according to claim 1, which is a contact lens.

16. The medical device according to claim 1, wherein the silicone hydrogel is a polymer comprising: a repeat unit (A) derived from a monomer represented by General Formula (I): ##STR00014## wherein, in General Formula (I), R.sup.a represents hydrogen or a methyl group; R.sup.b represents a hydrogen atom, a sulfonic group, a phosphate group, or an organic group having from 1 to 15 carbon atoms; and n represents an integer within the range of 1 to 40; a repeat unit (B) derived from a monomer represented by General Formula (a): ##STR00015## wherein, in General Formula (a), R.sup.1 represents a hydrogen atom or a methyl group; R.sup.2 represents a divalent C.sub.1-C.sub.20 organic group; R.sup.3 to R.sup.6 each independently represent a C.sub.1-C.sub.20 alkyl group which is optionally substituted, or a C.sub.6-C.sub.20 aryl group which is optionally substituted; R.sup.7 represents a C.sub.1-C.sub.20 alkyl group which is optionally substituted, or a C.sub.6-C.sub.20 aryl group which is optionally substituted; and k represents an integer of 1 to 200 which optionally has a distribution; and a repeat unit (C) derived from a monomer represented by General Formula (II-1): ##STR00016## or General Formula (II-2): ##STR00017## wherein, in General Formula (II-1) and General Formula (II-2), R.sup.8 and R.sup.11 each independently represent a hydrogen atom or a methyl group; R.sup.9 and R.sup.10, and R.sup.12 and R.sup.13 represent a hydrogen atom(s), and/or a C.sub.1-C.sub.20 alkyl group(s) which is/are either branched or linear, which optionally contain(s) a cyclic structure, and which is/are optionally substituted; and R.sup.12 and R.sup.13 optionally bind to each other to form a ring.

17. The medical device according to claim 16, comprising: the repeat unit (A) in an amount within the range of 5% by mass to 50% by mass with respect to the total mass of the silicone hydrogel in dry state; the repeat unit (B) in an amount within the range of 20% by mass to 70% by mass with respect to the total mass of the silicone hydrogel in dry state; and the repeat unit (C) in an amount within the range of 5% by mass to 50% by mass with respect to the total mass of the silicone hydrogel in dry state; with the proviso that the total of the repeat units (A), (B), and (C) does not exceed 100% by mass with respect to the total mass of the silicone hydrogel in dry state.

18. The medical device according to claim 17, wherein the total of the repeat units (A), (B), and (C) exceeds 50% by mass with respect to the total mass of the silicone hydrogel in dry state.

Description

EXAMPLES

[0181] The present invention will now be concretely described by way of Examples. Before description of each example, measurement methods and evaluation methods for various properties are described.

(1) Diameter

[0182] A contact lens sample was immersed in a predetermined volume of borate buffer in a petri dish, and a magnified projection image (at a magnification of 10) was obtained using an all-purpose projector V-10A manufactured by Nikon Corporation, followed by measuring the diameter using a ruler. The measured value was divided by 10, and the resulting value was recorded as the lens diameter.

(2) Transparency

[0183] A sample in a wet state with borate buffer was subjected to visual observation of transparency, and rated on a 5-point scale according to the following standard. 5: Not cloudy; transparent. 4: Slightly cloudy. 3: Rather cloudy; semi-transparent. 2: Cloudy; not transparent at all. 1: Completely white.

(3) Wettability

[0184] A contact lens sample was immersed in borate buffer in a beaker at room temperature (25 C.) for not less than 24 hours. The beaker containing the test piece and borate buffer was subjected to treatment with an ultrasonic washer (for 1 minute). The test piece was taken out of the borate buffer and held in air such that the diameter direction was vertically oriented. The surface condition was visually observed to measure the surface liquid film retention time.

(4) Water Content

[0185] For a contact lens sample, the mass in hydrous state (W1) and the mass in dry state (W2) were measured, and the water content was calculated according to the following equation.

Water content (%)=(W1W2)/W1100

(5) Tensile Elongation at Break and Tensile Elastic Modulus in Hydrous State From a contact lens sample in hydrous state, a dumbbell-shaped sample having a width of 5 mm in the narrowest portion was cut out, and the sample prepared was subjected to measurement of the thickness using an ABC Digimatic Indicator (ID-C112, manufactured by Mitutoyo Corporation), and then to measurement of the tensile elastic modulus and the elongation at break using Tensilon (RTM-100, manufactured by Toyo Baldwin Co., Ltd.; crosshead speed, 100 mm/minute).

(6) Zero-Stress Period

[0186] From near the center of a contact lens sample in hydrous state, a strip-shaped sample having a width of 5 mm and a length of 1.5 cm was cut out, and the sample prepared was subjected to measurement using a rheometer CR-500DX manufactured by Sun Scientific Co., Ltd. An operation in which [0187] a sample having a width of 5 mm and a thickness within the range of 0.05 mm to 0.2 mm held at an inter-supporting-point distance of 5 mm (State A) was drawn using a load cell with a maximum load of 2 kg at a rate of 100 mm/minute until the inter-supporting-point distance became 10 mm, and then [0188] the inter-supporting-point distance was reduced to 5 mm at the same rate, was repeated three times while obtaining measured values at 20-millisecond intervals, and the length of time [0189] from the time point when the stress became zero during the second reduction of the inter-supporting-point distance to 5 mm [0190] to the time point when the stress became non-zero after starting the third drawing was measured.
In State A, the test piece was held such that loosening of the test piece was prevented as much as possible, and such that the stress became zero.

[0191] The range within which the stress was regarded as zero was set to a range of the measured value of -0.05 gf to 0.05 gf.

(7) Lubrication

[0192] A contact lens sample was immersed in phosphate buffer in a vial at room temperature, and subjected to steam sterilization. The sample was then taken out of the phosphate buffer, and rubbed with a human finger five times to perform sensory evaluation on the following 5-point rating scale. [0193] 5: Excellent lubrication [0194] 4: Lubrication at a level almost intermediate between 5 and 3 [0195] 3: Moderate level of lubrication [0196] 2: Slight lubrication (at a level almost intermediate between 3 and 1) [0197] 1: No lubrication

(8) Dynamic Contact Angle

[0198] After steam sterilization, a contact lens in hydrous state was taken out of a package solution, and a strip-shaped sample having a width of 5 mm was cut out. After measuring the thickness of the outer edge portion of the lens, the lens was immersed in borate buffer, followed by performing ultrasonic washing for 20 seconds. The sample prepared was subjected to measurement of the dynamic contact angle against borate buffer using a dynamic contact angle meter WET-6000 manufactured by Rhesca Co., Ltd., wherein an operation of advancing (movement of immersing the sample in borate buffer) and receding (movement of completely taking out the sample immersed in the borate buffer) was repeated twice, and wherein the second dynamic contact angle was subjected to comparison (immersion speed, 7 mm/minute).

(9) Tensile Elastic Modulus in Dry State

[0199] From a contact lens sample in hydrous state, a dumbbell-shaped sample having a width of 5 mm in the narrowest portion was cut out, and the sample was dried in a vacuum dryer at 40 C. for not less than 16 hours to provide a sample in dry state, followed by measuring the width of the narrowest portion using a vernier caliper. Further, the thickness was measured using an ABC Digimatic Indicator (ID-C112, manufactured by Mitutoyo Corporation), and then the tensile elastic modulus was measured using Tensilon (RTM-100, manufactured by Toyo Baldwin Co., Ltd.; crosshead speed, 100 mm/minute).

(10) Oxygen Permeability

[0200] Three sheet-shaped silicone hydrogels with different thicknesses (0.26 mm, 0.52 mm, or 0.77 mm in thickness) having the composition of Example 2 were prepared by performing polymerization between glass plates. The sheet-shaped samples were processed to have a diameter of about 15 mm, and immersed in physiological saline for not less than 1 hour. Using a film oxygen permeability meter K-316 (manufactured by Tsukuba Rika Seiki Co., Ltd.), each processed sample was mounted on a jig, and placed in physiological saline bubbled with nitrogen gas. With application of a constant voltage, equilibration was allowed until the current value became stable. After the current value became stable, the bubbling gas was changed from nitrogen gas to oxygen gas. In this process, the electric current generated by electrode reaction of oxygen that permeated through the sample was recorded. The measurement was carried out at a temperature within the range of 35.0 C.0.5 C. From the resulting value, the oxygen permeability coefficient was calculated with reference to an ISO standard (ISO18369-4:2006) and a document (Efron N et al., Optom. Vis. Sci. 2007; 84(4) 328-337), to provide an index of oxygen permeability.

(11) Lipid Adhesion Resistance

[0201] A stirring bar (36 mm) was placed in a 500-mL beaker, and 1.5 g of methyl palmitate and 500 g of pure water were placed in the beaker. The temperature of a water bath was set to 37 C., and the above beaker was placed at the center of the water bath, followed by stirring with a magnetic stirrer for 1 hour. The rotation speed was set to 600 rpm. Each sample, with a spherical crown shape (diameter of the edge portion, about 14 mm; thickness, about 0.1 mm), was placed in a basket, and then fed into the above beaker, followed by stirring in this state. One hour later, the stirring was stopped, and the sample in the basket was washed by scrubbing using tap water at 40 C. and a household liquid detergent (Mama Lemon (registered trademark), manufactured by Lion Corporation). The washed sample was placed in a 12-well plastic dish containing distilled water, and left to stand in a refrigerator overnight. Cloudiness of the sample was visually observed, and the amount of methyl palmitate adhering to the sample was judged according to the following standard. [0202] 5: Not cloudy; transparent [0203] 4: Slight presence of cloudy portions [0204] 3: Considerable presence of cloudy portions [0205] 2: Mostly cloudy [0206] 1: Entirely cloudy

[0207] Abbreviations of the monomers and the like used in the Examples are as follows. [0208] MEA: 2-Methoxyethyl acrylate [0209] bm200: Blenmer (registered trademark) PME-200, manufactured by NOF Corporation (methoxypolyethylene glycol monomethacrylate; repeat number of polyethylene glycol portion, about 4) [0210] bm400: Blenmer (registered trademark) PME-400, manufactured by NOF Corporation (methoxypolyethylene glycol monomethacrylate; repeat number of polyethylene glycol portion, about 9) [0211] TRIS: 3-[Tris(trimethylsiloxy)silyl]propyl methacrylate, manufactured by Tokyo Chemical Industry Co., Ltd. [0212] mPDMS: Monofunctional linear silicone monomer represented by the following Formula (s1) (average molecular weight, 1000; MCR-M11, manufactured by Gelest, Inc.)

##STR00012## [0213] DMAA: N,N-Dimethylacrylamide, manufactured by Tokyo Chemical Industry Co., Ltd. 164AS: Bifunctional silicone monomer X-22-164AS, manufactured by Shin-Etsu Chemical Co., Ltd. (,-di-(3-methacryloxy-propyl)-polydimethylsiloxane); functional group equivalent, 450 [0214] 164A: Bifunctional silicone monomer X-22-164A, manufactured by Shin-Etsu Chemical Co., Ltd. (,-di-(3-methacryloxy-propyl)-polydimethylsiloxane); functional group equivalent, 860 [0215] 164B: Bifunctional silicone monomer X-22-164B, manufactured by Shin-Etsu Chemical Co., Ltd. (,-di-(3-methacryloxy-propyl)-polydimethylsiloxane); functional group equivalent, 1600 [0216] 164C: Bifunctional silicone monomer X-22-164C, manufactured by Shin-Etsu Chemical Co., Ltd. (,-di-(3-methacryloxy-propyl)-polydimethylsiloxane); functional group equivalent, 2400 [0217] 3G: Triethylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd. [0218] NVP: N-Vinylpyrrolidone, manufactured by Tokyo Chemical Industry Co., Ltd. [0219] FM0711: Monofunctional linear silicone monomer Silaplane (registered trademark), manufactured by JNC Corporation (polydimethylsiloxane monomethacrylate); average molecular weight, 1000 [0220] FM7721: Bifunctional silicone monomer Silaplane (registered trademark), manufactured by JNC Corporation (,-di-(3-methacryloxy-propyl)-polydimethylsiloxane); average molecular weight, 5000 [0221] NB: Ultraviolet absorber 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole, manufactured by Tokyo Chemical Industry Co., Ltd. [0222] RB: Coloring agent Reactive Blue 246, manufactured by Arran Chemical Co., Ltd. (1,4-bis[4-(2-methacryloxyethyl)phenylamino]anthraquinone) [0223] IC: Photoinitiator Irgacure (registered trademark) 819, manufactured by Ciba Specialty Chemicals (phenylbis(2,4,6-trimethylbenzoyl)-phosphine oxide). [0224] TAA: tent-Amyl alcohol, manufactured by Tokyo Chemical Industry Co., Ltd. [0225] RO water: Pure water obtained by filtration through a reverse osmosis membrane

Example 1

[0226] A mixture was prepared by sufficiently mixing 22% by mass MEA, 43% by mass mPDMS, 25% by mass DMAA, 10% by mass 164B, 0.5% by mass NB, 0.02% by mass RB, 0.2% by mass IC, and 40% by mass TAA together, and the mixture was filtered through a membrane filter (0.45 m) to remove insoluble components, to obtain a monomer composition. Here, the total of MEA, mPDMS, DMA, and 164B, which form a silicone hydrogel after polymerization, is regarded as 100% by mass in the calculation. The monomer composition was injected into a contact lens mold made of a transparent resin (base curve side, polypropylene; front curve side, cyclic polyolefin), and irradiated with light (1.01 mW/cm.sup.2, 20 minutes) using a fluorescent lamp (Toshiba, FL-6D, daylight color, 6 W, four tubes) under a nitrogen atmosphere to allow polymerization. After the polymerization, the composition, together with the mold, was immersed in a solution of isopropyl alcohol:water=1:1, and warmed at 60 C. for 1 hour, followed by detaching a molded article having a contact lens shape from the mold. The resulting molded article was immersed in a solution of isopropyl alcohol:water=3:7 (volume ratio before mixing) at room temperature for 30 minutes, and then immersed in clean RO water. The article was then left to stand and stored overnight.

[0227] The molded article was taken out of the RO water, and then immersed in 1% by mass aqueous polyacrylic acid solution (weight average molecular weight, 250 kD) at room temperature for 10 minutes, followed by sufficient washing with RO water. Thereafter, the molded article was immersed in borate buffer, and then subjected to steam sterilization to prepare a contact lens sample. The resulting contact lens sample was subjected to various kinds of measurement. The results are summarized in Table 2.

Examples 2 to 6

[0228] Lenses were prepared in the same manner as in Example 1 except that the monomer mixing ratio was changed as shown in Table 1, and subjected to evaluation. The measurement results are summarized in Table 2.

[0229] Table 2 shows the results of measurement of various physical properties required for contact lenses. All of Examples 1 to 6 showed results sufficient for use as contact lenses.

Comparative Example 1

[0230] With reference to Patent Document 1, a monomer composition composed of 74.1% by mass MEA, 24.7% by mass TRIS, 1% by mass 3G, 0.2% by mass IC, and 45% by mass TAA was polymerized. However, the resulting product was just a white, strongly curled, and very sticky polymer mass, which was not suitable for use as a contact lens.

TABLE-US-00001 TABLE 1 Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Monomer MEA 74.1 22 22 22 22 composition bm200 22 [% by mass] bm400 22 TRIS 24.7 mPDMS 43 43 53 48 43 FM0711 43 DMAA 25 25 15 20 25 NVP 25 164A 4 164B 10 10 6 10 164C 10 FM7721 10 3G 1 NB 0.5 0.5 0.5 0.5 0.5 0.5 RB 0.02 0.02 0.02 0.02 0.02 0.02 IC 0.2 0.2 0.2 0.2 0.2 0.2 0.2 TAA 45 40 40 40 40 40 40 Silicon atom content 6.6 16.6 16.7 19.7 18.1 17.1 16.6 in dry state [%]

TABLE-US-00002 TABLE 2 Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 In hydrous Diameter N/A.sup. 14.6 14.8 14.3 14.7 14.8 14.7 state (mm) Transparency 1 4 4 4 5 4 4 Wettability 0 60<.sup. 60<.sup. 60<.sup. 48.6 60<.sup. 60<.sup. (seconds) Water 26.9 31.7 35.0 30.1 35.9 33.3 32.1 content (%) Tensile N/A.sup. 464 537 217 291 509 369 elongation (%) Elastic N/A.sup. 0.57 0.43 0.53 0.61 0.48 0.45 modulus (MPa) Zero-stress N/A.sup. <1.sup. <1.sup. <1.sup. <1.sup. <1.sup. <1.sup. period (seconds) Lubrication N/A.sup. 5 5 5 5 5 5 Dynamic N/A.sup. 33.2 34.7 34.1 33.3 34.3 34.8 contact angle, advancing () Dynamic N/A.sup. 32.0 32.0 31.8 27.6 32.1 31.2 contact angle, receding ()

Examples 8 to 13

[0231] The components described in Table 3 were mixed well, and the resulting mixture was filtered through a membrane filter (0.45 m) to remove insoluble components, to obtain a monomer composition. The monomer composition was injected into a contact lens mold made of a resin (polypropylene). Under air atmosphere, irradiation was performed using an LED light with a center wavelength of 405 nm at 0.8 mW/cm.sup.2 for 1 hour from above and below the monomer composition, to allow polymerization. After the polymerization, the composition, together with the mold, was immersed in a solution of isopropyl alcohol:water=7:3 (volume ratio before mixing), and warmed at 70 C. for 1 hour, followed by detaching a molded article having a contact lens shape from the mold. The resulting molded article was immersed in a solution of isopropyl alcohol:water=7:3 (volume ratio before mixing) at 70 C. for 3 hours, and then immersed in clean RO water. The article was then left to stand and stored overnight. The molded article was taken out of the RO water, and then immersed in 1% by mass aqueous polyacrylic acid solution (weight average molecular weight, 250 kD) at room temperature for 10 minutes, followed by sufficient washing with RO water. Thereafter, the molded article was immersed in borate buffer, and then subjected to steam sterilization to prepare a contact lens. The resulting contact lens was subjected to various kinds of measurement. The results are summarized in Table 4.

TABLE-US-00003 TABLE 3 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Monomer MEA 22 22 22 22 22 22 22 composition mPDMS 40 43 23 [% by mass] FM0711 40 40 40 40 DMAA 25 25 25 25 25 25 45 164AS 10 8 6 4 10 164A 10 10 NB 0.5 0.5 0.5 0.5 0.5 0.5 0.1 RB 0.02 0.02 0.02 0.02 0.02 0.02 0.1 IC 0.5 0.5 0.5 0.5 0.5 0.2 0.2 TAA 40 40 40 40 40 40 40 Silicon atom content 15.8 15.5 15.3 15.0 15.5 16.4 10.3 in dry state [%]

Example 14

[0232] Contact lenses were prepared in the same manner as in Examples 8 to 13 except that polymerization was carried out by irradiation using a fluorescent lamp (Toshiba, FL-6D, daylight color, 6 W, four tubes) (1.01 mW/cm.sup.2, 20 minutes). Results of various kinds of measurement are shown in Table 4.

Example 7, Examples 15 to 21, and Comparative Examples 2 to 4 (Comparison with Commercially Available Products)

[0233] The following three kinds of commercially available products, and the lenses of Example 1 and Examples 8 to 14, were compared for the physical properties shown in Table 4 (wherein the oxygen permeability values for Dailies Total 1 (registered trademark) and MyDay (registered trademark) in Table 4 were calculated from values available from the manufacturers).

[0234] Oasys: ACUVUE (registered trademark), manufactured by Johnson & Johnson Total one: Dailies Total 1 (registered trademark), manufactured by Alcon MyDay: MyDay (registered trademark), manufactured by CooperVision

[0235] Here, the results of evaluation of physical properties using the lens of Example 1 are shown as Example 7; the results of evaluation of physical properties using the lenses of Examples 8 to 14 are shown as Examples 15 to 21; and the results for Oasys, Total one, and MyDay are shown as Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively, in Table 4.

TABLE-US-00004 TABLE 4 In hydrous state In dry state Tensile Tensile Oxygen Tensile Dry Water elongation Elastic permeability Elastic elastic Wettability content at break Modulus coefficient Modulus modulus Transparency (seconds) (%) (%) (MPa) (*) (MPa) ratio Comparative Oasys 3 12.8 36.2 367 0.8 83 15 18.8 Example 2 Comparative Total one 4 60<.sup. 30.5 255 0.7 105 9.1 12.8 Example 3 Comparative MyDay 4 60<.sup. 55.0 388 0.5 60 16 29.6 Example 4 Example 7 Lens of 4 60<.sup. 31.7 464 0.6 80 1.3 2.2 Example 1 Example 15 Lens of 4 60<.sup. 34.6 1.1 1.8 1.5 Example 8 Example 16 Lens of 4 60<.sup. 32.7 0.9 1.7 1.9 Example 9 Example 17 Lens of 4 60<.sup. 30.8 0.9 1.7 1.9 Example 10 Example 18 Lens of 4 60<.sup. 33.0 0.6 1.7 3.0 Example 11 Example 19 Lens of 4 60<.sup. 32.4 0.8 1.5 1.8 Example 12 Example 20 Lens of 4 60<.sup. 33.6 0.8 0.8 1.0 Example 13 Example 21 Lens of 4 60<.sup. 40.3 0.6 2.4 4.2 Example 14

[0236] Regarding the tensile elastic modulus in dry state, the commercially available products showed values of not less than 9 MPa, indicating very high hardness. In contrast, the lenses of Example 1 and Examples 8 to 14 of the present invention showed values of as low as about 0.8 to 2.4 MPa even in dry state, indicating softness of these lenses equivalent to that in hydrous state.

[0237] From these results, it can be said that the silicone hydrogel lens used in the present invention has an appropriate tensile elastic modulus in hydrous state, and excellent oxygen permeability, transparency, and shape recovery performance, that these physical properties are satisfied in a well-balanced manner, and that the lens has a sufficiently low tensile elastic modulus in either hydrous state or dry state, so that the lens allows suppression of stimulation of the eyeball due to dryness.

[0238] The meanings of the symbols used in the tables are as follows. [0239] : N/A means that measurement was impossible. [0240] : 60< means an excellent wettability of not less than 60 seconds. [0241] : <1 means an excellent shape recovery performance of 0.1 second to 1 second. [0242] The unit of the oxygen permeability coefficient (*) is as follows: 10.sup.11: (cm.sup.2/second) mL O.sub.2/(mL.Math.hPa).

Example 22

[0243] Instead of the contact lens mold made of a transparent resin used in Example 1, two transparent glass plates having a size of 10 cm10 cm with a thickness of 3 mm and a spacer with a thickness of 200 m sandwiched therebetween were used.

[0244] The spacer was prepared by stacking two sheets each of which was prepared by cutting out the central portion (a square of 6 cm6 cm) of Parafilm (registered trademark; LMS Co., Ltd.) having a size of 10 cm10 cm100-m thickness. A film-shaped molded article was obtained by the same procedure as in Example 1 except that the monomer composition was filled into the gap formed with the glass plates and the spacer instead of the contact lens mold made of a transparent resin. An area of 3 cm3 cm near the center of the resulting film-shaped molded article was cut out. The resulting piece was applied to the skin. As a result, it was flexible and gave a good feeling of touch. The good feeling of touch continued even in dry state since hardening of the article did not occur. It was thus thought that the article can be suitably used as a wound dressing.

Example 23

[0245] With reference to JP 6-510687 A, a corneal inlay having a diameter of 2 mm, central thickness of 20 m, peripheral thickness of 20 m, base radius of curvature of 7.6 mm, and optical power of +2.5 D was prepared. The corneal inlay was obtained by the same procedure as in Example 1 except that a corneal inlay mold made of a transparent resin was used instead of the contact lens mold made of a transparent resin. It was thought that the resulting product can be suitably used as a corneal inlay.

INDUSTRIAL APPLICABILITY

[0246] Examples of uses of the present invention include ophthalmic lenses, endoscopes, catheters, infusion tubes, gas transfer tubes, stents, sheaths, cuffs, tube connectors, access ports, drainage bags, blood circuits, wound dressings, and drug carriers. In particular, contact lenses, intraocular lenses, artificial corneas, corneal inlays, and corneal onlays are preferred. Contact lenses are most preferred.