JP2002182166A - Plastic molding and contact lens consisting of it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic molding for a contact lens or the like excellent in transparency, wettability, oxygen permeability and mechanical characteristic. SOLUTION: This plastic molding has a surface where a difference between an advance contact angle and a sweepback contact angle is within 40 deg. in a dynamic contact angle to water, and a difference between the advance contact angle and the sweepback contact angle is within 20 deg. in the dynamic contact angle to a boric acid buffer solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic molded article having excellent hydrophilicity (water wettability) and stainability (lipid stain, protein stain) by controlling the surface. And intraocular lenses.

[0002]

2. Description of the Related Art In recent years, plastic molded articles have been proposed for various uses. Among them, various plastic molded articles containing silicon or fluorine have been proposed for contact lenses because of their good oxygen permeability. However, plastic molded articles containing silicon and fluorine have insufficient water wettability, and improvement in water wettability is desired. In particular, various methods have been proposed for the purpose of modifying the surface of a contact lens to improve the lens characteristics and the feeling of wearing the lens. For example, U.S. Pat. No. 4,214,014 discloses a method of imparting water wettability to a contact lens by performing a plasma treatment in an oxygen atmosphere. Further, Japanese Patent Application Laid-Open No. 8-227001 discloses a method of imparting water wettability to a water-containing contact lens by performing a plasma treatment in an oxygen gas and / or carbon dioxide gas atmosphere. However, such a prior art certainly has a problem that the material of the plastic molded article is deteriorated by oxygen gas, although the water wettability is improved. Further, there is a serious problem that the water wettability changes with time and becomes hydrophobic when used for washing or long-term use. Further, in the case of a highly water-containing plastic molded product, there is a problem that the evaluation of water wettability depends on visual observation and is qualitative and cannot be quantitatively evaluated.

[0003]

SUMMARY OF THE INVENTION The present inventors have made intensive studies to solve the above-mentioned drawbacks, controlling the advancing contact angle and the receding contact angle of the surface while maintaining the original physical properties of the plastic, and changing over time. The present inventors have found out that the surface of a plastic molded article without any specific control is specifically controlled, and have reached the present invention. An object of the present invention is to provide a plastic molded product having high water content, high transparency and high oxygen permeability, good water wettability, and excellent mechanical properties, especially a surface suitable for contact lenses. An object is to provide the relationship between the wettability and the dynamic contact angle.

[0004]

The present invention has the following arrangement to achieve the above object. "(1) The difference between the advancing contact angle and the receding contact angle in the dynamic contact angle with water is within 40 ° and the difference between the advancing contact angle and the receding contact angle in the dynamic contact angle with the borate buffer is 20.
A plastic molded article having a surface within ゜, (2) a plastic molded article according to claim 1 containing silicon and / or fluorine atoms, and (3) a plastic molded article having a water content of 15% or more. Product, and (4) a contact lens comprising the plastic molded product according to any one of claims 1 to 3 ".

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The plastic molded articles of the present invention include homopolymers of various monomers described below, copolymers of these monomers and other monomers, and polymers containing silicon in the main chain and / or side chains. A molded article mainly composed of a polymer (for example, a polymer containing an organic silane group such as a siloxane bond or a trimethylsilyl group) or a polymer containing a carbon or fluorine bond. Specific examples of monomers for obtaining such a polymer include tris (trimethylsiloxy) silylpropyl (meth) acrylate, polydimethylsiloxane having double bonds at both ends, silicone-containing (meth) acrylate and fluorine-containing (meth) acrylate. Is mentioned. Examples of the plastic molded article of the present invention include homopolymers using these monomers, and copolymers of these monomers and other monomers. Monomers that can be copolymerized include monofunctional monomers such as (meth) acrylic monomers, aromatic vinyl monomers, and heterocyclic vinyl monomers, or bifunctional, trifunctional, tetrafunctional (meth) acrylates, aromatic divinyl monomers, Examples include polyfunctional monomers such as aromatic diaryl monomers. Specific examples of the monofunctional monomer include alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate, carboxylic acids such as (meth) acrylic acid, and cycloalkyl (meta) such as cyclohexyl (meth) acrylate. ) Acrylates, halogenated alkyl (meth) acrylates such as trifluoroethyl (meth) acrylate, hexafluoroisopropyl (meth) acrylate, 2
Hydroxyalkyl (meth) acrylates having a hydroxyl group, such as -hydroxyethyl (meth) acrylate and 2,3-dihydroxypropyl (meth) acrylate;
Diacrylamides such as N, N-dimethylacrylamide and N, N-diethylacrylamide; alkyl (meth) acrylates having a siloxanyl group such as tris (trimethylsiloxy) silylpropyl (meth) acrylate; and aromatics such as styrene and vinylpyridine. And heterocyclic vinyl monomers such as N-vinylpyrrolidone. Specific examples of the bifunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, bisphenol A di (meth) acrylate, ethylene oxide-added dibisphenol A (meth) acrylate and its urethane modified product, propylene glycol ( Meta)
Acrylate, glycerol di (meth) acrylate,
Neopentyl glycol (meth) acrylate and the like. Specific examples of the trifunctional monomer include trimethylolpropane tri (meth) acrylate and ethylene oxide-added trimethylolpropane tri (meth) acrylate. Specific examples of the tetrafunctional monomer include tetramethylolmethanetetra (meth) acrylate. Specific examples of the aromatic divinyl monomer include divinylbenzene and the like, and specific examples of the aromatic diaryl monomer include diaryl phthalate. Specific examples of other polyfunctional monomers include bismaleimide and allyl (meth) acrylate. Depending on the copolymerization ratio of these monomers, the plastic molded article used in the present invention may be a hydrogel containing water, a rubbery polymer containing no water, or a hard polymer containing no or low water content. There may be.

[0006] The plastic molded article of the present invention may be transparent or opaque.
Alternatively, a plastic molded article containing a fluorine atom is preferably applied to an optical material or the like because of its excellent oxygen permeability. In this case, a plastic article having transparency is preferably used. In the polymer constituting the plastic molded article of the present invention, the content of the polymer containing silicon and / or fluorine atoms is preferably 5% by weight or more, more preferably from the viewpoint of the balance between oxygen permeability and mechanical properties. 30% by weight or more. In addition, a well-known method can be used as a polymerization method. Further, the plastic molded article of the present invention may contain an ultraviolet absorber, a dye, a colorant, and the like. When obtaining the plastic molded article of the present invention, it is preferable to add a thermal polymerization initiator represented by a peroxide or an azo compound, or a photopolymerization initiator in order to facilitate polymerization. In the case of performing the thermal polymerization, a material having an optimum decomposition characteristic for a desired reaction temperature is selected and used.
Generally, a peroxide initiator and an azo initiator having a 10-hour half-life temperature of 40 to 120 ° C. are suitable. Examples of the photopolymerization initiator include carbonyl compounds, peroxides, azo compounds, sulfur compounds, halogen compounds and metal salts. These polymerization initiators are used alone or as a mixture, and are used in an amount up to about 1% by weight. When obtaining the plastic molded article of the present invention, a polymerization solvent can be used. As the solvent, various organic and inorganic solvents can be used and are not particularly limited. For example, water, methanol, ethanol, propanol, 2-
Various alcohol solvents such as propanol, butanol, tert-butanol, benzene, toluene, various aromatic hydrocarbon solvents such as xylene, hexane, heptane,
Various aliphatic hydrocarbon solvents such as octane, decane, petroleum ether, kerosene, ligroin and paraffin; various ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethyl acetate, butyl acetate, methyl benzoate, dioctyl phthalate Various ester solvents, diethyl ether, tetrahydrofuran, dioxane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether, various glycol ether solvents such as polyethylene glycol dialkyl ether, and the like, These can be used alone or as a mixture.

[0007] The plastic molded article of the present invention is, for example,
It can be manufactured by the following method.

That is, the polymer is once formed into a round bar or a plate shape and processed into a desired shape by cutting or the like, or a known method such as mold polymerization or spin cast polymerization can be used. . Further, when forming into a fiber, a film, or the like, the polymer can be melted or dissolved with a solvent, and then spun and extruded.

As an example, a case where the plastic molded article of the present invention is obtained by a mold polymerization method will be described below. The monomer mixture of the monomer composition and the polymerization initiator is filled into two voids having a predetermined shape. And
Photopolymerization or thermal polymerization is performed to form a mold. The mold is made of resin, glass, ceramics, metal, or the like. In the case of photopolymerization, an optically transparent material is used, and usually, resin or glass is used.
When manufacturing plastic molded parts,
A void is formed by the two opposing molds,
The void is filled with the monomer mixture, but depending on the shape of the mold and the properties of the monomer mixture, a gasket having a purpose of giving a certain thickness to the plastic molded article and preventing liquid leakage of the filled monomer mixture is also used. good. The mold in which the voids are filled with the monomer mixture is subsequently irradiated with an actinic ray such as ultraviolet light, or is heated in an oven or a liquid tank to be polymerized. There may be a method of using both polymerization methods in which thermal polymerization is performed after photopolymerization, or conversely, photopolymerization is performed after thermal polymerization. In the case of photopolymerization, for example, light containing a large amount of ultraviolet light using a mercury lamp or insect lamp as a light source is generally irradiated for a short time, and usually within one hour. In the case of performing thermal polymerization, the condition of gradually increasing the temperature from around room temperature to raising the temperature to 60 to 200 ° C. over several hours to several tens of hours maintains the optical uniformity and quality of the plastic molded product. It is suitable for improving the reproducibility.

The borate buffer of the present invention is a package filling solution for contact lenses, which is 9.26 g of boric acid, 1.00 g of sodium borate, 8.48 g of sodium chloride and 0.10 g of a preservative disodium ethylenediaminetetraacetate.
Is dissolved in 1000 g of purified water at a concentration of about 1.8%.

The dynamic contact angle of the present invention is an evaluation of the surface tension and the contact angle based on the principle of the Wilhelmy method.
In this method, a plate-like or rod-like test piece is immersed in a liquid, and the surface tension or contact angle of the liquid is determined by actually measuring the resultant force of the surface tension and buoyancy generated at that time.
The relationship between the surface tension γ of the liquid and the contact angle θ and the actually measured force F is as shown in FIG. 1. In the equilibrium state, F = γcosθL−AρD F = mG F = mG + γcosθ1 F = mG + γcosθ1−f .

Here, m: mass G: gravitational acceleration f: buoyancy L: contact length For correction term of buoyancy; A: cross-sectional area of plate or cylinder ρ: density of liquid D: immersion depth If the force F is actually measured by changing only D, F becomes a linear function of D, and its intercept,
(ΓCOSθl) is required. In this way, from this value, the value of the contact angle is calculated if the surface tension of the sample is known, or conversely, if the contact angle is known, the value of the surface tension is calculated. When measuring up to a certain immersion depth D,
The force F changing with time is measured continuously, and the relations of FD obtained in this way are arranged as shown in FIG. 3, where the test piece is immersed in the liquid sample. The intercept Fad is read from the relation of F → D, and the intercept Fre is similarly read from the relation of D → F at the time of retreat. If the surface tension γ of the liquid sample at this time is known, “forward contact” is obtained from the following equation. The angle “θad” and the “receding contact angle” θre are determined.

Advancing contact angle: cosθad = Fad / γL receding contact angle: cosθre = Fre / γL where the surface tension γ of water is 72.75 [dyne / cm], and the surface tension of borate buffer is 72.00 [ dyne / cm].

The difference between the advancing contact angle and the receding contact angle of the dynamic contact angle to water or borate buffer of the present invention is called hysteresis of wetting. This hysteresis of wetting occurs because the adsorption of the liquid is different between forward and backward. In particular, when a plastic molded body is used for a contact lens, the smaller the hysteresis of this wetting due to the influence of the upper and lower eyes, the better. Furthermore, if the hysteresis of the wetting is large, the feeling of dryness and dirt is likely to be exerted during mounting. If the liquid is water at the dynamic contact angle, the difference is 6
At 0 ° or more, a phenomenon in which the water layer adhering to the plastic surface is clearly repelled upon retreat is observed, and the water wettability is poor. At 50 ° or more, a phenomenon in which the water layer is slightly repelled is observed, and the water wettability is slightly poor. is there. The difference is over 40 ゜ and 5
If it is less than 0 °, the holding power of the water layer attached to the surface is insufficient. When the difference is within 40 °, a thick water layer adhered to the plastic surface is observed, and a surface having good water wettability is obtained. In the case of a borate buffer solution, when the difference is 60 ° or more, a phenomenon that the water layer adhering to the plastic surface is clearly repelled when retreating is observed, and the water wettability is poor. A repelling phenomenon was observed, and the water wettability was somewhat poor. When the difference is more than 20 ° and less than 40 °, the holding power of the water layer attached to the surface is insufficient.
When the difference is within 20 °, a thick water layer adhered to the plastic surface is observed, and a surface having good water wettability is obtained.

According to the present invention, a surface is formed in which the difference between the advancing contact angle and the receding contact angle with water is within 40 ° and the dynamic contact angle with the borate buffer is within 20 ° with the difference between the advancing contact angle and the receding contact angle. Known means such as a physical treatment such as a plasma treatment or a corona discharge treatment, a chemical surface treatment such as an acid or a base, a graft onto a plastic molded article, a modification of a polymer, and a polymer complex can be applied as the means for causing this. In the case of a hydrogel plastic molded product, a chemical surface treatment such as a high molecular weight acid or base having a molecular weight of 1,000 or more is preferable. In particular, it is effective to ionize only the surface of the plastic molded article and increase the water content of the surface layer to reduce the hysteresis of the wetting, and depending on the conditions, it becomes possible to make it within 10 °, 5 ° or even 0 °. However, the means used in the present invention is not limited to the method described above.

The plastic molded article of the present invention has a water content of 1
It is preferably at least 5%. By setting the water content to 15% or more, the movement of the lens in the eye becomes smooth, and continuous wearing can be made easier.

Preferred embodiments of the plastic molded article of the present invention include lenses, fibers, films and the like. Particularly, from the viewpoint of good optical properties, high oxygen permeability, good water wettability and mechanical properties. It is suitably used for optical articles such as contact lenses, intraocular lenses, and plastic lenses.

[0018]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Each measurement and evaluation was carried out by the following methods. 1. Water content After the plastic molded article was hydrated, the water content (%) of the polymer was measured by the following formula.

Water content (%) = (W-WO) / W * 100 (W is the weight (g) of the plastic molded article after the hydration treatment, and WO is the weight of the plastic molded article in a dry state. (G)). 2. Dynamic Contact Angle Using a plastic molded product having a size of 5 mm × 10 mm × 0.1 mm, a dynamic contact angle between water and borate buffer (pH 7.1 to 7.3) was measured. Immersion speed is 0.1mm / sec
c, the immersion depth was 7 mm. 3. Water wettability The plastic molded product is treated with water or borate buffer (pH 7.1).
To 7.3), and then lifted up, the surface appearance was visually observed, and evaluated according to the following criteria.

A: The surface of the plastic molded product is uniformly wet.

：: More than half of the surface area of the plastic molded product is uniformly wet.

Δ: Wetting of more than half of the area of the surface of the plastic molded product is non-uniform.

X: The surface of the plastic molded product was hardly wet. 4. Mechanical Properties As a sample, a plastic molded product having a size of 15 mm × 10 mm × 0.1 mm was used, and the elastic modulus was measured using Tensilon RTM-100 manufactured by Toyo Baldwin Co., Ltd. Pull at a speed of 100 mm / min,
The distance between the grips was 5 mm. Example 1 Tris (trimethylsiloxy) silylpropyl methacrylate 55 parts by weight, N, N-dimethylacrylamide 4
5 parts by weight, triethylene glycol dimethacrylate 1
Parts by weight and 10 parts by weight of diethylene glycol dimethyl ether are uniformly mixed, and "Darocur 1" is used as a polymerization initiator.
After adding 0.2 parts by weight of 173 "(manufactured by CIBA),
The monomer mixture was degassed under an argon atmosphere. It was injected between plastic molds in a glove box under a nitrogen atmosphere and sealed. Polymerization was performed by irradiating light (illuminance: 1 mW / cm ² , 30 minutes) using a trap lamp. Then, the mold was immersed in diethylene glycol dimethyl ether at 40 ° C./30 minutes, and further 60 ° C./60 minutes.
After immersing for a minute, the mold was released to obtain a plastic molded article to be treated. Thereafter, diethylene glycol dimethyl ether was replaced with isopropyl alcohol, and the remaining monomer was extracted at 60 ° C. for 16 hours. Thereafter, the plastic molded article to be treated is washed twice with isopropyl alcohol, and then isopropyl alcohol / purified water = 50/5.
0 (parts by weight) for 30 minutes, then immersed in isopropyl alcohol / purified water = 25/75 (parts by weight) for 30 minutes, further immersed in purified water for 16 hours, and removed isopropyl alcohol from the plastic molded product. It was completely removed to obtain a plastic molded article to be treated. The above-mentioned plastic molded article to be treated was treated at 40 ° C. /
It was immersed for 8 hours. Thereafter, the plastic molded product is sufficiently washed with purified water, and then the borate buffer (p.
H7.1 to 7.3), and the vial was sealed.
Place the vial in an autoclave,
The mixture was boiled for minutes. After cooling, the plastic molded product was removed from the vial, and the borate buffer (pH 7.1 to 7.1) was used.
7.3). The water content of this plastic molded product was 38%, the advancing contact angle in borate buffer solution was 45 °, the receding contact angle was 41 °, and the difference was 4 °. The water wettability was also excellent. The forward contact angle in water was 56 °, the receding contact angle was 35 °, and the difference was 21 °. The water wettability was also excellent. Further, the mechanical properties were an elastic modulus of 98 psi and an elongation at break of 489%. Example 2 In Example 1, 15 parts by weight of a polydimethylsiloxane macromer (MW: 1,900) having polymerizable groups at both terminals, 45 parts by weight of tris (trimethylsiloxy) silylpropyl methacrylate, N, N-dimethylacrylamide 40 Change to parts by weight, light irradiation time is 12 minutes,
1.2 wt% polyacrylic acid (average molecular weight 250,00
0) The same operation was performed except that the film was immersed in an aqueous solution (pH 3.1) at 23 ° C. for 4 hours. The water content of this molded plastic product was 28%, the advancing contact angle in the borate buffer solution was 32 °, the receding contact angle was 27 °, and the difference was 5 °.
The water wettability was also excellent. The forward contact angle in water is 54
At ゜, the receding contact angle was 22 °, and the difference was 32 °. The water wettability was also excellent. Further, the mechanical properties were an elastic modulus of 154 psi and an elongation at break of 227%. Example 3 Tris (trimethylsiloxy) silylpropyl methacrylate 30.5 parts by weight, compound (M1) 30.5 parts by weight, N, N-dimethylacrylamide 39 parts by weight, triethylene glycol dimethacrylate 1 part by weight, polyethylene glycol monomethyl Ether (MW: 350)
10 parts by weight were uniformly mixed, and 0.2 part by weight of "Darocur 1173" (manufactured by CIBA) was added as a polymerization initiator, and then the monomer mixture was degassed under an argon atmosphere. It was injected between plastic molds in a glove box under a nitrogen atmosphere and sealed. The polymerization was performed by irradiating light (illuminance: 1 mW / cm ² , 12 minutes) using a trap lamp. Thereafter, each mold was immersed in isopropyl alcohol, immersed at 40 ° C./30 minutes, and further immersed at 60 ° C./120 minutes, and released to obtain a plastic molded article to be treated.
Thereafter, the remaining monomer was extracted at 60 ° C. for 16 hours. Thereafter, the plastic molded article to be treated is washed twice with isopropyl alcohol, and then immersed in isopropyl alcohol / purified water = 50/50 (parts by weight) for 30 minutes, and then isopropyl alcohol / purified water = 25/75.
(Weight part) for 30 minutes and further immersed in purified water for 16 hours, and completely removed isopropyl alcohol from the plastic molded product to obtain a plastic molded product to be treated. 1.2 wt% of the plastic molded article to be treated
It was immersed in an aqueous solution of polyacrylic acid (average molecular weight: 250,000) (pH 3.1) at 23 ° C. for 4 hours. afterwards,
After sufficiently washing the molded plastic product with purified water, the plastic molded product was immersed in a borate buffer (pH 7.1 to 7.3) in the vial, and the vial was sealed. The vial was placed in an autoclave and subjected to boiling at 120 ° C. for 30 minutes.
After cooling, the plastic molded product was taken out of the vial and immersed in a borate buffer (pH 7.1 to 7.3). The water content of this plastic molded product was 32%, the advancing contact angle in the borate buffer solution was 26 °, the receding contact angle was 19 °, and the difference was 7 °. The water wettability was also excellent. The forward contact angle in water was 51 °, the receding contact angle was 20 °, and the difference was 31 °. The water wettability was also excellent. Further, the mechanical properties were an elastic modulus of 77 psi and an elongation at break of 392%.

[0025]

Embedded image

Example 4 25 parts by weight of the compound of (M1) of Example 3, 50 parts by weight of tris (trimethylsiloxy) silylpropyl acrylate, 25 parts by weight of N-vinylformamide, acrylic acid 1
Parts by weight, 0.2 parts by weight of vinyl acrylate, 1 part by weight of triethylene glycol dimethacrylate, and 20 parts by weight of diethylene glycol dimethyl ether are uniformly mixed, and 0.2 parts by weight of "Darocur 1173" (manufactured by CIBA) as a polymerization initiator. Was added, the monomer mixture was degassed under an argon atmosphere. It was injected between plastic molds in a glove box under a nitrogen atmosphere and sealed. Light irradiation using an insect lamp (illuminance 1 mW / cm ² , 1
(2 minutes) to carry out polymerization. Thereafter, release was performed using tweezers to obtain a plastic molded article to be processed. Thereafter, the remaining monomer was extracted with isopropyl alcohol at 60 ° C. for 16 hours. Then, after the plastic article to be processed is washed twice with isopropyl alcohol,
First, immersed in isopropyl alcohol / purified water = 50/50 (parts by weight) for 30 minutes, then immersed in isopropyl alcohol / purified water = 25/75 (parts by weight) for 30 minutes, and immersed in purified water for 16 hours. Then, isopropyl alcohol was completely removed from the plastic molded product to obtain a plastic molded product to be treated. The plastic article to be treated was immersed in a 0.25 N NaOH aqueous solution at 23 ° C. for 24 hours. Then, after sufficiently washing the plastic molded product with purified water, the borate buffer solution (pH
7.1 to 7.3), and the vial was sealed. Place the vial in an autoclave,
The mixture was boiled for minutes. After cooling, the plastic molded product was removed from the vial, and the borate buffer (pH 7.1 to 7.1) was used.
7.3). The water content of this plastic molded product was 34%, the advancing contact angle in borate buffer solution was 45 ° and the receding contact angle was 44 °, and the difference was 1 °. The water wettability was also excellent. The forward contact angle in water was 68 °, the receding contact angle was 44 °, and the difference was 24 °. The water wettability was also excellent. Further, the mechanical properties were an elastic modulus of 68 psi and an elongation at break of 390%. Comparative Example 1 The procedure of Example 1 was repeated except that the polyacrylic acid aqueous solution treatment was not performed. The water content of this plastic molded product was 36%, the advancing contact angle in the borate buffer solution was 78 ° and the receding contact angle was 42 °, and the difference was 36 °. The water wettability was also poor. The forward contact angle in water was 84 °, the receding contact angle was 33 °, and the difference was 51 °. The water wettability was also poor. Further, the mechanical properties were an elastic modulus of 144 psi and an elongation at break of 646%. Comparative Example 2 The procedure of Example 2 was repeated except that the polyacrylic acid aqueous solution treatment was not performed. The water content of this plastic molded product was 26%, the advancing contact angle in the borate buffer solution was 74 °, the receding contact angle was 27 °, and the difference was 47 °. The water wettability was also poor. The forward contact angle in water was 86 °, the receding contact angle was 21 °, and the difference was 65 °. The water wettability was also poor. Further, the mechanical properties were an elastic modulus of 211 psi and an elongation at break of 250%. Comparative Example 3 The procedure of Example 3 was repeated except that the polyacrylic acid aqueous solution treatment was not performed. The water content of this plastic molded product was 30%, the advancing contact angle in the borate buffer solution was 77 °, the receding contact angle was 34 °, and the difference was 43 °. The water wettability was also poor. The forward contact angle in water was 85 °, the receding contact angle was 30 °, and the difference was 55 °. The water wettability was also poor. Further, the mechanical properties were an elastic modulus of 86 psi and an elongation at break of 227%. Comparative Example 4 In Example 4, it carried out similarly except not performing a 0.25N-NaOH aqueous solution process. The water content of this plastic molded product was 30%, the advancing contact angle in the borate buffer solution was 80 °, the receding contact angle was 45 °, and the difference was 35 °. The water wettability was also poor. The forward contact angle in water is 89 ° and the receding contact angle is 40 °, and the difference is 49 °.
Was ゜. The water wettability was also poor. Further, the mechanical properties were an elastic modulus of 100 psi and an elongation at break of 450%.

[0027]

According to the present invention, it is possible to obtain a plastic molded article having excellent hydrophilicity with no change over time on the surface thereof while maintaining various properties of the plastic molded article.

In particular, when the plastic molded article is an optical article such as a contact lens, an intraocular lens, or a plastic lens, the above-described excellent performance is exhibited, and an excellent product is obtained.

[Brief description of the drawings]

Fig. 1 Principle of surface tension measurement by Wilhelmy method (Part 1)

FIG. 2 Principle of surface tension measurement by Wilhelmy method (part 2)

FIG. 3 Principle of measuring surface tension by Wilhelmy method (part 3)

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Claims (4)

[Claims] The difference between the advancing contact angle and the receding contact angle in the dynamic contact angle with water is within 40 °, and the difference between the advancing contact angle and the receding contact angle in the dynamic contact angle with the borate buffer is within 20 °. Plastic molded article having a surface. 2. The plastic molded article according to claim 1, which contains silicon and / or fluorine atoms. 3. The method according to claim 1, wherein the water content is 15% or more.
A plastic molded product as described. 4. A contact lens comprising the plastic molded product according to claim 1.