JPH04180013A - Production of contact lens - Google Patents

Abstract

PURPOSE:To eliminate the nonuniformity of a monomer soln. at the time of graft polymn. and to allow a uniform surface graft treatment by executing the graft polymn. treatment onto the surface of a contact lens base material while applying oscillation thereto. CONSTITUTION:The contact lens base material which is a copolymer of alkyl methacrylate and siloxanyl methacrylate (expressed by constitutional formula I) and consists of the copolymer consisting of about 60wt.% methyl methacrylate, about 35wt.% trissilyl propyl methacrylate and about 5wt.% 2-hydroxyethyl methacrylate is installed in a discharge device and is subjected to a glow discharge treatment. After the lens base material is exposed into the air, the material is put into a test tube and the monomer soln. essentially consisting of acrylamide is added into the test tube in the amt. at which the lens base material is sufficiently immersed therein. The test tube is then connected to a vacuum system and the inside of the tube is deaerated to execute vacuum sealing of the tube. The test tube is inserted into a reciprocating shaking machine and the graft polymn. treatment on the surface of the lens base material is executed while the oscillation is applied to the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a manufacturing method for obtaining a hard contact lens that permanently maintains surface wettability and is comfortable to wear.

[Prior Art] In order to reduce the feeling of a foreign body when wearing a contact lens and improve the feeling of wearing it, it is important to improve the compatibility between the cornea and the lens surface. A specific method is to improve the wettability of the lens surface by graft polymerizing acrylamide, which is a hydrophilic child, onto the surface of the contact lens. By the way, to briefly explain the treatment process of surface graft polymerization, first, a contact lens base material that has been subjected to an electric discharge treatment or the like is immersed in a solution of 100% water. Next, after removing dissolved oxygen, this is heated and subjected to polymerization treatment. Conventionally, during this polymerization, the polymerization container was kept stationary.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, the concentration distribution in the Senzummer solution becomes non-uniform during the polymerization process, which causes the grafting state on the surface of the contact lens base material to become non-uniform. In some cases, the surface was cloudy.

Therefore, in order to solve these conventional problems, the present invention aims to eliminate the non-uniformity of the monomer solution during graft polymerization and manufacture a contact lens that enables homogeneous surface grafting treatment. The purpose is to provide a method.

[Means for Solving the Problems] In order to solve the above problems, the method for manufacturing a contact lens of the present invention comprises at least alkyl methacrylate, siloxanyl methacrylate (wherein X and Y are C + −
It is selected from the group consisting of C6 alkyl groups and groups, Z is a group having the structural formula % Formula %], and A represents a C1 to C5 alkyl group.

k, 1. m and n represent Ol or a positive integer. 6) Concerning a contact lens base material made from a polymer of an ester compound of methacrylic acid, which is a copolymer with A method for producing a contact lens comprising the steps of: immersing in a solution containing acrylamide as a main component; and (C) graft polymerizing acrylamide onto the surface of the base material.
It is characterized by performing the polymerization treatment during the process while applying shaking.

In addition, the following are listed as typical ester compounds of methacrylic acid.

Pentamethyldisiloxanyl methyl methacrylate Tris(trimethylsiloxy)-γ-methacryloxypropylsilane CH3 CH3-3i-CH3 CH3-5i-CH3 CH3 Isobutylhexamethyltrisiloxanyl methyl methacrylate The details of the present invention are described below with reference to Examples. shows.

[Example 1] Crosslinking agent N,N'-methylenebisacrylamide 2
．． Dissolve 5g of acrylamide and 10g of acrylamide in distilled water.
0 ml, and an aqueous solution of 1,000 ml was prepared.

Graft polymerization was carried out as follows. Methyl methacquarate 60wt%, Tris (trimethylsiloxy)
A contact lens base material made of a copolymer of 35 wt% silylpropyl methacrylate and 5 wt% 2-hydroxyethyl methacrylate was prepared. Discharge device (between electrodes 6
Centimeters, voltage between electrodes 270 volts, frequency 60
The lens base material was placed in a 0.04 Torr argon atmosphere and subjected to glow discharge treatment for 5 seconds. After the discharge-treated lens base material was exposed to the air, it was placed in a test tube, and the monomer aqueous solution was added in an amount sufficient to submerge the lens base material. This was connected to a vacuum system, the inside of the tube was degassed, and the tube was then vacuum sealed. In this state, the test tube was inserted into a reciprocating machine (E'P-1, manufactured by Taiyo Service Center Co., Ltd.) and subjected to graft polymerization treatment on the substrate surface for 60 minutes at a constant temperature of 80°C while shaking. went. After completion of polymerization, the presence or absence of cloudiness on the treated surface was evaluated using an optical microscope. The swinging conditions (oscillation period, amplitude) of the reciprocating machine were set as shown in Table 1, and six samples (samples 1 to 6) were studied.

On the other hand, for comparison, we also investigated the surface graft polymerization treatment without shaking as before (Comparative Examples 1 to 6).
).

As is clear from Table 1, all of the samples in which the graft polymerization was shaken (Samples 1 to 6) had good surface conditions, with no clouding or the like. On the other hand, as a result of observation under an optical microscope, those that were not subjected to shaking during polymerization (Comparative Examples 1 to 6) were found to have cloudy parts over part or the entire surface.

From the above results, it has become clear that the uniformity of the concentration of the Senzummer solution can be ensured by applying agitation during graft polymerization, and that this is very effective in improving the surface grafting state.

Table 1 O: Good surface condition (no cloudiness)
Dissolve 5g of acrylamide and 10g of acrylamide in distilled water.
0 ml, and a monomer aqueous solution was prepared.

Graft polymerization was carried out as follows. Methyl methacrylate 60wt%, Tris (trimethylsiloxy)
A contact lens base material made of a copolymer of 35 wt% silylpropyl methacrylate and 5 wt% 2-hydroxyethyl methacrylate was prepared. Interelectrode distance 3.5 cm, interelectrode voltage 15 kilovolts, frequency 60
This lens base material was placed in a space created by a 1.5 mm thick spacer between the electrodes of a Hertz corona discharge treatment device, and discharge treatment was performed. In addition, 4 on each side, 4 on both sides.
Discharge treatment was performed for 0 seconds each. Next, this discharge-treated lens base material was placed in a test tube, and the monomer aqueous solution was added in an amount sufficient to soak the lens base material. This was connected to a vacuum system, the inside of the tube was degassed, and the tube was then vacuum sealed. In this state, the test tube was inserted into a reciprocating machine (EP-1, manufactured by Taiyo Service Center Co., Ltd.), and graft polymerization was performed on the substrate surface for 60 minutes at a constant temperature of 80°C while shaking. . The presence or absence of cloudiness on the treated surface was evaluated using an optical microscope. In addition, the swinging conditions of the reciprocating shaker (oscillation period, amplitude)
were set as shown in Table 2, and six samples (samples 1 to 6) were examined.

On the other hand, for comparison, we also investigated the surface graft polymerization treatment without shaking as usual (Comparative Examples 1 to 6).
).

As is clear from Table 2, all of the samples subjected to shaking during graft polymerization (Samples 1 to 6) had good surface conditions, with no clouding or the like. On the other hand, as a result of observation under an optical microscope, those that were not subjected to shaking during polymerization (Comparative Examples 1 to 6) were found to have cloudy parts over part or the entire surface.

From the above results, it has become clear that the uniformity of the concentration of the Senzummer solution can be ensured by applying agitation during graft polymerization, and that this is very effective in improving the surface grafting state.

Table 2 O Good surface condition (no clouding) Similar results were obtained for surface treatments of polyvinyl chloride, polyvinylidene chloride, acetate, polyester, polyvinyl alcohol, polystyrene, polycarbonate, and various other polymeric materials. Furthermore, the above-mentioned materials 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 uniformity of the concentration of the Senzummer solution is ensured by applying shaking during graft polymerization, which is effective in improving the surface grafting state. It turned out to be very effective.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] At least alkyl methacrylate, siloxanyl methacrylate (▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, X and Y are C_1 to C_5 alkyl groups and Z
is selected from the group consisting of groups, Z is a group having the structural formula ▲ Numerical formula, chemical formula, table, etc. ▼, and A represents an alkyl group of C_1 to C_5. k, l, m, and n represent 0 or a positive integer. (a)
A process of discharging the surface under normal pressure or reduced pressure,
(b) immersing the base material in a monomer solution containing acrylamide as a main component; and (c) graft polymerizing acrylamide onto the surface of the base material. A method for manufacturing a contact lens, characterized in that the polymerization process inside the contact lens is performed while shaking the lens.