JPH03220519A - Production of contact lens - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to contact lenses, and particularly to hard contact lenses that have excellent wettability and wear comfort.

[Prior Art] As a means of reducing the foreign body sensation when wearing contact lenses and improving the so-called wearing comfort, hydrophilic monomers are graft-polymerized on the different surfaces of contact lenses to improve wettability, thereby bonding the cornea and lens. There is a way to improve the conformability of the surface. In performing surface grafting, the surface is first subjected to electrical discharge treatment to generate radicals on the surface. At this time,
In order to make the grafting on the lens surface uniform and free from individual variations, it is necessary to optimize the discharge treatment time and control the density and amount of generated radicals. Conventionally, it was thought that the longer the discharge time, the more radicals would be introduced to the lens surface, resulting in a larger amount of grafting and better surface wettability.

[Problems to be solved by the invention] However, with the above-mentioned conventional technology, if the discharge time is not long, not only will the cost be high, but the generated radicals will start to lose their activity, the amount of grafting will become small, and the surface wettability will be poor. Become. However, if the discharge time is short, a sufficient amount of radicals cannot be introduced, so the amount of grafting becomes small and the discharge effect becomes nil. Therefore, the invention is to solve such lsJM point, and the purpose is to find an optimal discharge time that is sufficient to introduce a large amount of radicals, and that does not cause the generated radicals to lose their activity. It is an object of the present invention to provide a contact lens manufacturing method that ensures graft polymerization by setting the following conditions.

[Means for Solving the Problems] In order to solve the above problems, the method for manufacturing a contact lens of the present invention includes (1) at least ゛alkyl methacrylate and siloxanyl methacrylate (wherein X and Y are O2 to C2); A polymer of an ester compound of methacrylic acid, which is a copolymer with an alkyl group (Z represents an alkyl group in the structural formula; m and n represent 0 or a positive integer) In contact lens base materials made from
In the method for manufacturing a contact lens, the method includes a step of subjecting the surface to a discharge treatment under normal pressure or reduced pressure, and (2) a step of graft polymerizing N,N-dimethylacrylamide to the lens surface. time from 2 seconds to 1
It is characterized by being turned off by setting it to 0 minutes.

Typical ester compounds of methacrylic acid include the following.

1, Hebutamethyltrisiloxanylethyl acrylate 2, Tris(trimethylsiloxy)-γ-methacryloxypropylsilane 3゜Phenyltetramethyldisiloxanylethyl acrylate 4, Peshita/) + Ruzik E xanylmethyl methacrylate 5, Hentamethyldi(trimethylsiloxy)-methacryloxymethylsilane [Action: Radicals are generated on the surface of the laminated body by treating the laminated body of the contact lens. When this layered product is exposed to an oxygen atmosphere, peroxides such as 10-0-H are produced. Furthermore, when this is immersed in a hydrophilic monomer solution and the temperature is raised, the peroxide decomposes and becomes an initiator, starting polymerization and grafting the hydrophilic monomer.

The density and amount of generated radicals depend on the discharge time. Radicals are not generated when the discharge time is less than 0 to 2 seconds. If the reaction time is less than 2 to 5 seconds, the density and amount of radicals produced are minute, and if graft polymerization is proceeded in this state, the graft monomer assumes a five-dimensional crosslinked structure due to the lack of radicals, forming a water-insoluble polymer. The surface wettability at this time is very poor. In addition, when the discharge lasts for 5 minutes or more, the radicals on the surface are in a saturated state, so the amount of grafting changes little with respect to the discharge time.
There is no need to lengthen the discharge time unnecessarily.

Hereinafter, the details of the present invention will be shown by examples.

[Example] (Example 1) Methyl methacrylate 60 wt%, tris(trimethylsiloxy)silylpropyl methacrylate) 35 wt%,
A contact lens base material made of a copolymer containing 5 wt % of 2-hydroxyethyl methacrylate was prepared. Place the lens base material in a discharge device (6 cm between electrodes, 270 volts between electrodes, 60 Hz frequency) and
Glow discharge treatment was performed in an argon atmosphere of 0.04 Torr. After the discharge-treated lens base material was exposed to the air, the lens base material was placed in a test tube, a 10 wt % N,N-dimethylacrylamide aqueous solution was added thereto, the tube was replaced with nitrogen gas, and the tube was sealed under reduced pressure. Place the test tube in a constant temperature bath at 60°C for 15 hours.
N,N-dimethylacrylamide was graft-polymerized onto the surface of the lens base material. After polymerization, the lens was immersed in hot pure water at 70°C, and the by-product homopolymer was removed by stirring the pure water overnight. A total of 14 samples were prepared by changing the glow discharge time and producing a total of 14 samples (Table 1). Ninhydrin color reaction was also used to detect N and N on the lens.
-,) Methylacrylamide was quantified and the amount of grafting was determined.

These results are the first on the table Raise it.

Table *N [11~9:5ec N[110~14: Tomo] As is clear from Table 1, samples 2 to 13, that is, those with discharge time of 2 seconds to 10 minutes, have N and N' after surface treatment. −
The grafting amount of dimethylacrylamide is 3μ9 cm-
It can be seen that it is attached as 2 or more.

When the discharge time is limited to 5 seconds to 5 minutes (Samples 3 to 12),
A particle size of 10μ7m-2 or more was obtained. The contact angles obtained were also improved, with the contact angles of samples 6 to 9 being improved from 91° before treatment to 17°. Moreover, the obtained values were uniform, with no variation from individual to individual.

(Example 2) Methyl methacrylate 60 wt%, tris(trimethylsiloxy)silylpropyl methacrylate 35 wt%,
A contact lens base material made of a copolymer of 5 wt% 2-hydroxyethyl methacrylate was prepared. This lens base material was placed in a space created by a 1.5 x 17 m thick spacer between the electrodes of a corona discharge treatment device with an inter-electrode distance of 35 cm, an inter-electrode voltage of 15 kilovolts, and a frequency of 60 Hz, and the discharge treatment was carried out. I did it. Note that both sides were treated, one side at a time. Next, this discharge-treated lens base material was placed in a test tube, and 10 wt% N was added thereto.

After adding an aqueous N-dimethylacrylamide solution and purging with nitrogen gas, the tube was sealed under reduced pressure. Place the test tube in a thermostat at 60°C.
N,N-dimethylacrylamide was graft-polymerized onto the surface of the lens base material.

After polymerization, the lens was immersed in hot pure water at 70°C, and the by-product homopolymer was removed by stirring the pure water overnight. A total of 14 samples were prepared by performing the same operation while changing the corona discharge time (Table 2). In addition, N,N-dimethylacrylamide on the lens was quantified using ninhydrin color reaction to determine the amount of grafting. These results are listed in Table 2. It is obvious that if the distance between the electrodes, the voltage, etc. are changed, the appropriate ejection time will also change. However, considering that the amount of grafting depends on the amount of radicals generated by discharge, the discharge time should be 2 seconds or more even if the conditions are slightly different.
It can be said that it is appropriate to set the time to 10 minutes, preferably 5 seconds to 5 minutes.

Table *N (L1 to 9: 5ee NlLlo to 14: Order) As is clear from Table 2 above, samples 2 to 13, that is, those with a discharge time of 2 seconds to 10 minutes, have N, N after surface treatment.
-) Grafting amount of methylacrylamide is 9μ2o-2
It's bigger than that. Discharge time: 5 seconds to 5 minutes (Samples 3. to 12)
), l 5 p f/an-2 or higher was obtained. The contact angle of the resulting lens base material was also improved,
The contact angle of samples 6-9 was improved from 91° before treatment to 16°. Moreover, the values obtained were uniform with no variation among individuals.

Although the embodiments of the present invention have been described above using Si-based PMMA contact lenses, the present invention is not limited thereto, and is not limited to polyethylene film, polypropylene, polyvinyl chloride, polyvinylidene chloride, acetate, polyester, polyvinyl alcohol, polystyrene. , polycarbonate, and other plastic films.Furthermore, the above-mentioned resins can be used for various packaging materials, agricultural water retention materials, and medical applications such as artificial organs. It can also be applied to commercial products.

[Effects of the Invention] As described above, according to the present invention, the discharge time is 2 seconds to 1
By setting the time to 0 minutes, preferably 5 seconds to 5 minutes, it became possible to permanently enhance the effect of subsequent surface modification. As a result, there are no defects or variations in the surface modification state, and the effects brought about are enormous, such as mass processing and significant cost reductions.

Claims (1)

[Claims] (1) At least alkyl methacrylate and siloxanyl methacrylate ▲ Numerical formulas, chemical formulas, tables, etc. , chemical formula, table, etc. It is a group with ▼, and A
represents an alkyl group of C_1 to C_5. Also, m and n are 0
Or indicates a positive integer. ) In contact lens base materials made from polymers of ester compounds of methacrylic acid, which are copolymers with
A process of discharging the surface under normal pressure or reduced pressure,
A contact lens manufacturing method comprising a step of graft polymerizing N,N dimethylacrylamide onto the lens surface, wherein the discharge time of the discharge treatment step is 2 seconds to 10 seconds.
A method for manufacturing contact lenses, characterized in that the manufacturing method is performed by setting the contact lenses for 1 minute.