JPH03217816A - 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 [Field of Industrial 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, it is possible to improve the wettability by graft polymerizing hydrophilic monomers on the contact lens surface, thereby creating a bond between the cornea and the lens surface. There are ways to improve familiarity. During polymerization, a temperature is required that provides energy to break the 10101 bonds of the peroxide introduced onto the lens surface through discharge treatment. Conventionally, when setting the polymerization temperature, it has been thought that it is sufficient to supply a temperature sufficient to decompose the peroxide, which is the starting species.

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, if the polymerization temperature is too high, not only will the cost increase, but the lens material will be deformed and altered, making it unsuitable for surface modification. Furthermore, if the polymerization temperature is low, the monomers may form a three-dimensional crosslinked structure, forming a graft polymer that is insoluble in water. This cross-linked kraft volima has the disadvantage that it forms protrusions that corrode the lens surface, significantly reducing wettability. The present invention is intended to solve these problems, and its purpose is to supply the minimum temperature necessary for the peroxide introduced to the lens surface to decompose, while also preventing the lens material from deforming. A contact lens manufacturing method that ensures graft polymerization by setting an optimal polymerization temperature that is high enough to suppress three-dimensional crosslinking of monomers and suppress the temperature to prevent deterioration. Our goal is to provide the following.

[1,000 Steps to Solve the Problems In order to solve the above problems, the method for manufacturing a contact lens of the present invention comprises (1) at least an alkyl methacrylate and a siloxanyl methacrylate (wherein X and Y are C
Z represents an alkyl group of the structural formula Δ. m. n represents 0 or 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,
(2) A contact lens manufacturing method comprising the step of graft polymerizing acrylamide onto the lens surface,
It is characterized in that the polymerization temperature in step (2) is set at 60°C to 90°C, preferably around 80°C.

Typical ester compounds of methacrylic acid include the following.

Pentamethylmethac I Route CH
3 CH3 0 CH311111 CH3-Si-0-Si-CH2-0-C-C=CH2
CH3 CH3 Tris(trimethylsiloxy)-r-methacryloxybutyrsilane CH. CHa-Si-CH3 CH. 0 0CH3I
I IllCH3-S
i-0-Si-CH. CH2CH2-0-C-C=CH
．． Akebono CH. O CHz-Si-CHi CHI Isobutylhexamethyltrisiloxanyl methyl methacrylate 1 route Ill CH3 CH. CH. [Use 1] Radicals are generated on the surface of the contact lens molded product by processing it. When this compact is exposed to an oxygen atmosphere, peroxides such as 10-0-H are produced. Furthermore, when this is immersed in a hydrophilic monomer filtrate and the temperature is raised, the peroxide decomposes and becomes an initiating species, starting polymerization and grafting the hydrophilic monomer.

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

[Example 1] Methyl methacrylate 60 wt%, tris(trimethylsiloxy)silylbuvir methacrylate 35 wt%, 2
- A contact lens base material made of a copolymer of 5 wt % of hydroxyethyl methacrylate was prepared. Discharge device (
The lens base material was placed with a distance of 6 cm between the electrodes, an inter-electrode voltage of 270 volts, and a frequency of 60 Hz), 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 % acrylamide aqueous solution was added thereto, the tube was replaced with nitrogen gas, and the tube was sealed under reduced pressure. 6 test tubes
The lens was placed in a thermostatic bath at 0°C for 20 minutes to graft-polymerize acrylamide 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 13 samples were prepared by performing the same operation while changing the polymerization temperature (Table 1). In addition, the contact angle of the lens surface with water was measured using a droplet method. These results are listed in Table 1.

Lens base material modification (Example 21 60 wt% methyl methacrylate, 35 wt% tris(tonomethylsiloxy)silylbrobyl methacrylate, 2
A contact lens base material made of a copolymer of 5 wt% -hydroxyethyl methacrylate was prepared. This lens base material was placed in a space created by a 14.5 mm thick spacer between the electrodes of a corona discharge treatment device with an interelectrode distance of 3.5 cm, an interelectrode voltage of 15 kilovolts, and a frequency of 60 Hz, and the discharge treatment was performed. Ta. I treated both sides, one side at a time. Next, this discharge-treated lens base material was placed in a test tube, a 10 wt % acrylamide aqueous solution was added thereto, the tube was replaced with nitrogen gas, and the tube was sealed under reduced pressure. The test tube was placed in a constant temperature bath at 60° C. for 20 minutes to graft-polymerize acrylamide 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 13 samples were prepared by performing the same operation while changing the polymerization temperature (Table 2). In addition, the contact angle of the lens surface with water was measured using a droplet method. These results are listed in Table 2.

Table 2 Polymerization time 20 minutes - Lens base material deformation As is clear from Tables 1 and 2, samples 1 and 2, that is, polymerization temperatures of 45°C or lower, did not undergo peroxide decomposition. The contact angle did not decrease. Samples 3 and 4
, that is, for polymerization temperatures of 50°C and 55°C, 3
The contact angle was high due to the formation of a dimensional cross-linked graft polymer. At temperatures above 60°C (samples 5 to 11), the contact angle decreases significantly, especially at temperatures above 80°C (samples 9 to 11).
The minimum value was taken for . However, when the polymerization temperature exceeds 90° C., the lens material is deformed, making it unsuitable for surface modification.

As shown in Examples 1 and 2 above, it can be said that it is appropriate to set the polymerization temperature at 60°C to 90°C, preferably around 80°C.

Although the embodiments of the present invention have been described 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,
Similar results were obtained for various other types of plastic films treated with Table 100. Furthermore, the above-mentioned resins can be applied to various packaging materials, agricultural water retaining materials, and medical products such as artificial organs.

[Effects of the Invention] As described above, according to the present invention, the polymerization temperature is set at 60°C to
By setting the temperature to 90°C, preferably around 80°C, 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 are great, such as mass processing and significant cost reductions.

that's all

Claims (1)

[Claims] (1) At least alkyl methacrylate and siloxanyl methacrylate (▲Mathematical formula, chemical formula, table, etc.▼ (In the formula, X and Y are selected from the group consisting of C_1 to C_5 alkyl groups and Z group, and Z is the structural formula▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A is a group with C_1 to C_5 alkyl groups. m and n are 0 or positive integers.)) In contact lens base materials made from polymers of ester compounds,
A process of discharging the surface under normal pressure or reduced pressure,
(2) A contact lens manufacturing method comprising the step of graft polymerizing acrylamide onto the lens surface,
A method for manufacturing a contact lens, characterized in that the polymerization temperature in step (2) is set at 60°C to 90°C, preferably around 80°C.