JP3013435B2 - Method of manufacturing contact lenses - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a manufacturing method for maintaining a surface wettability permanently and obtaining a hard contact lens having an excellent wearing feeling.

[Related Art] In order to reduce the feeling of foreign matter when wearing a contact lens and to improve the wearing feeling, it is important to improve the familiarity 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 monomer, on the surface of the contact lens. By the way, the treatment process of the surface graft polymerization will be briefly described. First, a contact lens substrate subjected to a discharge treatment or the like is immersed in a monomer solution. Next, after the dissolved oxygen is removed, heating and the like are performed to perform a polymerization treatment. Conventionally, at the time of this polymerization, the polymerization vessel was treated in a stationary state.

[Problems to be Solved by the Invention] However, in the above-described conventional technology, the concentration distribution in the monomer solution becomes non-uniform during the polymerization treatment, and the graft treatment state on the surface of the contact lens substrate becomes uniform due to this. In some cases, and white turbidity occurred on a part of the surface.

Therefore, the present invention solves the conventional problems described above, and aims to eliminate the non-uniformity of the monomer solution at the time of graft polymerization and to manufacture a contact lens that enables a uniform surface graft treatment. It is to provide a method.

[Means for Solving the Problems] In order to solve the above problems, the method for producing a contact lens according to the present invention comprises at least an alkyl methacrylate,
Siloxanyl methacrylate ( Wherein X and Y are selected from the group consisting of C ₁ -C ₅ alkyl groups and groups; A group having, A is an alkyl group of C ₁ -C _5. k, l,
m and n each represent 0 or a positive integer. A) a contact lens substrate made from a polymer of an ester compound of methacrylic acid, which is a copolymer of (a) with (a) a step of subjecting the surface to discharge treatment under normal pressure or reduced pressure; In the method for producing a contact lens, comprising: a step of immersing in a monomer solution containing acrylamide as a main component; and (c) a step of graft-polymerizing acrylamide on the surface of the base material, the polymerization treatment in the step (c) is oscillated. Is performed while giving the

The following are typical examples of methacrylic acid ester compounds.

Pentamethyldisiloxanylmethyl methacrylate Tris (trimethylsiloxy) -γ-methacryloxypropylsilane Isobutyl hexamethyltrisiloxanyl methyl methacrylate Hereinafter, the present invention will be described in detail with reference to examples.

[Example 1] N, N'-methylenebisacrylamide 2.5 as a crosslinking agent
g, 10 g of acrylamide dissolved in distilled water to make 100 ml,
An aqueous monomer solution was prepared.

The graft polymerization was performed as follows. A contact lens substrate made of a copolymer of methyl methacrylate 60 wt%, tris (trimethylsiloxy) silylpropyl methacrylate 35 wt%, and 2-hydroxyethyl methacrylate 5 wt% was prepared. The lens substrate was placed in a discharge device (6 cm between electrodes, voltage between electrodes 270 volts, frequency 60 Hz), and placed in a 0.04 torr argon atmosphere.
Glow discharge treatment was performed for seconds. After exposing the discharge-treated lens substrate to the air, it was placed in a test tube, and the aqueous monomer solution was added in an amount sufficient to soak the lens substrate. This was connected to a vacuum system, the inside of the tube was evacuated, and the tube was vacuum sealed as it was. In this state, insert the test tube into a reciprocating shaker (EP-1, manufactured by Taiyo Service Center Co., Ltd.)
Graft polymerization treatment was performed on the substrate surface at a constant temperature of 80 ° C for 60 minutes. After the completion of the polymerization, the presence or absence of cloudiness on the treated surface was evaluated with an optical microscope. In addition, the swing conditions (swing cycle, amplitude) of the reciprocating shaker were set as shown in Table 1, and six samples (samples 1 to 5) were prepared.
6) was examined.

On the other hand, for comparison, a case where a surface graft polymerization treatment was performed without giving a swing as before was also examined (Comparative Examples 1 to 5).
6).

As is evident from Table 1, all of the samples which were shaken during the graft polymerization (Samples 1 to 6) had good surface conditions and no cloudiness. On the other hand, those which were not shaken during polymerization (Comparative Examples 1 to 6) were observed under an optical microscope, and as a result, it was found that some or all of the surface had cloudiness.

From the above results, it was clarified that by imparting fluctuation during the graft polymerization, the uniformity of the concentration of the monomer solution was secured, and this was very effective in improving the surface graft state.

[Example 2] N, N'-methylenebisacrylamide 2.5 as a crosslinking agent
g, 10 g of acrylamide dissolved in distilled water to make 100 ml,
An aqueous monomer solution was prepared.

The graft polymerization was performed as follows. A contact lens substrate made of a copolymer of methyl methacrylate 60 wt%, tris (trimethylsiloxy) silylpropyl methacrylate 35 wt%, and 2-hydroxyethyl methacrylate 5 wt% was prepared. This lens substrate was placed in a space made of 1.5 mm thick spacers between the electrodes of a corona discharge treatment device having a distance between the electrodes of 3.5 cm, a voltage of the electrodes of 15 kV, and a frequency of 60 Hz, and discharge treatment was performed. In addition, discharge treatment was performed on each side and each side for 40 seconds. Next, the lens substrate subjected to the discharge treatment was placed in a test tube, and the aqueous monomer solution was added in such an amount that the lens substrate was sufficiently immersed. This was connected to a vacuum system, the inside of the tube was evacuated, and the tube was vacuum sealed as it was. In this state, the test tube was inserted into a reciprocating shaker (EP-1, manufactured by Taiyo Service Center Co., Ltd.) and subjected to a graft polymerization treatment on the substrate surface at a constant temperature of 80 ° C. for 60 minutes while being shaken. After the completion of the polymerization, the presence or absence of cloudiness on the treated surface was evaluated with an optical microscope. The swing conditions (swing cycle, amplitude) of the reciprocating shaker were set as shown in Table 2, and 6
The samples (Samples 1 to 6) were examined.

On the other hand, for comparison, a case where a surface graft polymerization treatment was performed without giving a swing as before was also examined (Comparative Examples 1 to 5).
6).

As is evident from Table 2, all the samples which were shaken during the graft polymerization (Samples 1 to 6) had good surface conditions and no cloudiness. On the other hand, those which were not shaken during polymerization (Comparative Examples 1 to 6) were observed under an optical microscope, and as a result, it was found that some or all of the surface had cloudiness.

From the above results, it was clarified that by imparting fluctuation during the graft polymerization, the uniformity of the concentration of the monomer solution was secured, and this was very effective in improving the surface graft state.

Examples of the present invention have been described using a Si-based PMMA contact lens, but without being limited thereto, polyethylene film, polypropylene, polyvinyl chloride, polyvinylidene chloride, acetate, polyester, polyvinyl alcohol, polystyrene, polycarbonate, Similar results were obtained for surface treatment of various other polymer materials. Furthermore, various packaging materials using the materials listed above,
It is also applicable to agricultural water retention materials or 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 monomer solution is ensured by imparting a swing at the time of graft polymerization. It became clear that the effect was great.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI C08J 7/16 C08J 7/16 (58) Field surveyed (Int.Cl. ⁷ , DB name) G02C 1/00-13/00 C08J 7 / 04-7/06

Claims (1)

(57) [Claims] (1) at least an alkyl methacrylate and a siloxanyl methacrylate ( Wherein X and Y are selected from the group consisting of C ₁ -C ₅ alkyl groups and Z groups; A group having, A is an alkyl group of C ₁ -C _5. k, l,
m and n each represent 0 or a positive integer. A) a contact lens substrate made from a polymer of an ester compound of methacrylic acid, which is a copolymer of (a) with (a) a step of subjecting the surface to discharge treatment under normal pressure or reduced pressure; In the method for producing a contact lens, comprising: a step of immersing in a monomer solution containing acrylamide as a main component; and (c) a step of graft-polymerizing acrylamide on the surface of the base material, the polymerization treatment in the step (c) is oscillated. A method for producing a contact lens, wherein the method is carried out while applying a force.