JPH04316013A - Manufacture of contact lens - Google Patents

Abstract

PURPOSE:To enhance the wear resistance of graft chains and to hold high wettability of the surface of the contact lens for a long period by adding a specified cross-linking agent to a polymerization system composed of an aqueous hydrophilic monomer solution. CONSTITUTION:The polymer to be used as the starting material to fabricate the contact lens is the polymer or (meth)acrylate, such as siloxyalkyl (meth) acrylate represented by formula I in which R is H or methyl, and each of X and Y is 1-6C alkyl, cycloalkyl, phenyl, etc. The cross-linking agent, such as N,N'-bismethyleneacrylamide or 2-hydroxyethyl (meth)acrylate, is added to a monomer solution in the manufacturing process.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to contact lenses, and more particularly to hard contact lenses that have excellent wettability and wear comfort.

0002

2. Description of the Related 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 graft-polymerize a hydrophilic monomer onto the contact lens surface to improve the wettability of the lens surface. Conventionally, graft polymerization has been carried out by bringing only a hydrophilic monomer into contact with a contact lens base material.

0003

[Problems to be Solved by the Invention] However, with the above-mentioned conventional technology, the adhesion strength between the graft polymer and the lens base material is low, and when rubbed with a finger, the graft polymer peels off and the wettability returns to the pre-grafting wettability. It had the disadvantage that it caused problems. Therefore, the present invention is intended to solve this problem, and its purpose is to provide a method for manufacturing contact lenses with high wear resistance that improves the adhesion strength between the lens base material and the graft polymer. be.

0004

[Means for Solving the Problems] In order to solve the above problems, the method for manufacturing a contact lens of the present invention provides a siloxy-substituted ester of acrylic acid or methacrylic acid (

[0005]

[Chemical formula 11]

), fluoroalkyl-substituted acrylic acid or methacrylic acid having not more than 20 fluorine atoms represented by the following general formula (

[0007]

[Chemical formula 12]

), polyfluoroalkylsiloxy-substituted esters of acrylic acid or methacrylic acid represented by the following general formula (

[0009]

[Chemical formula 13]

), acrylic (methacrylic)oxyalkylsilanol (

[0011]

[Chemical formula 14]

), polyacrylic represented by the following general formula (
methacrylic)oxyalkylpolysiloxane (

001
3]

[Chemical formula 15]

), fluorine-containing siloxanyl methacrylate (

[0015]

[Chemical formula 16]

), a fluorine-containing acrylic acid or methacrylic acid ester monomer (

00
17]

[Chemical formula 17]

), a fluorine-containing acrylic acid or methacrylic acid ester monomer represented by the following general formula:

001
9]

[Chemical formula 18]

), a fluorine-containing diacrylate or dimethacrylate monomer (

002
1]

[Chemical formula 19]

) and fluorine-containing cyclic olefins (

[0023]

[C20]

Regarding a contact lens base material made from a polymer of an ester compound of acrylic acid or methacrylic acid, which is a copolymer containing at least one of the above, (a) its surface is subjected to normal pressure or reduced pressure; The present invention is characterized in that a crosslinking agent is added to the aqueous monomer solution in step (b) of the method for producing contact lenses, which comprises the step of performing a discharge treatment below and (b) the step of graft polymerizing a hydrophilic monomer onto the lens surface.

The following are representative compounds represented by the above general formula.

Fluorobutylhexamethyltrisiloxanyl methacrylate

[0027]

[C21]

Trifluoroethyl methacrylate

00
29]

[Chemical formula 22]

Trifluoropropyltetramethyldisiloxanyl methyl methacrylate

[0031]

[C23]

[0032] The details of the present invention will be explained below with reference to Examples.

[0033]

【Example】

(Example 1) 2.5 g of N,N'-methylenebisacrylamide as a crosslinking agent and 10 g of acrylamide were dissolved in water to make 100 ml to prepare an aqueous monomer solution.

Graft polymerization was carried out as follows. 48 wt% γ-methacryloxypropyl-tris(trimethylsiloxy)silane, 19 wt% 2,2,2-trifluoroethyl methacrylate, 1,3-bis(γ-
(methacryloxypropyl)-1,1,3,3-tetrakis(trimethylsiloxy)disiloxane 8wt%, bis(trimethylsiloxy)-γ-methacryloxypropylsilanol 7wt%, methacrylic acid 10wt%, methyl methacrylate 1wt%, ethylene glycol Dimethacrylate 7wt%, 2,2'-azobis(2,4
-isobutyronitrile) (as a polymerization initiator) 0
．． A contact lens base material made of a 25 wt % copolymer was prepared. The lens base material was placed in a discharge device (electrode spacing 6 cm, interelectrode voltage 270 volts, frequency 60 Hz), and glow discharge treatment was performed for 5 seconds in an argon atmosphere of 0.04 Torr. After exposing the discharge-treated lens base material to the air, it was placed in a test tube, a crosslinking agent-added acrylamide monomer aqueous solution was added, 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 80°C for 60 minutes, and acrylamide was graft-polymerized on the surface of the lens base material (sample N
o. 1-6). In addition, for comparison with the conventional method, a sample was prepared using a 10 wt % acrylamide monomer aqueous solution to which no crosslinking agent was added. (Comparative Examples 1 to 6) The polymerization conditions at this time were exactly the same as those for the samples with the addition of a crosslinking agent. In addition, the treated lenses were rubbed 1,000 times with the palm of the hand sprinkled with detergent to perform an abrasion resistance test. Graft polymer peeling was evaluated by examining the change in contact angle between the lens surface before and after rubbing. The contact angle was measured by the dripping method, and water was used as the solvent. These results are listed in Table 1.

[0035]

[Table 1]

(Example 2) 48 wt% γ-methacryloxypropyl-tris(trimethylsiloxy)silane,
1,1-dihydroperfluorobutyl methacrylate 1
9 wt%, 1,3-bis(γ-methacryloxypropyl)-1,1,3,3-tetrakis(trimethylsiloxy)disiloxane 7 wt%, bis(trimethylsiloxy)-γ-methacryloxypropylsilanol 8 wt%
, 11 wt% methacrylic acid, 7 wt% ethylene glycol dimethacrylate, 2,2'-azobis(2,4-
isobutylnitrile) (as a polymerization initiator) 0
．． A contact lens base material made of a 25 wt % copolymer was prepared. This lens base material was placed in a space created by a 1.5 mm thick spacer between the electrodes of a corona discharge treatment device with an inter-electrode distance of 3.5 cm, an inter-electrode voltage of 15 kilovolts, and a frequency of 60 Hz, and the discharge treatment was performed. I did it. Incidentally, discharge treatment was applied to one side and both sides for 40 seconds each. Next, put this discharge-treated lens base material into a test tube.
A crosslinking agent-added acrylamide monomer aqueous solution similar to that used in Example 1 and a salt (ferrous ammonium sulfate) added thereto as a redox catalyst were injected therein. After replacing each tube with nitrogen gas, the tube was sealed under reduced pressure. 8 test tubes
The lenses were placed in a constant temperature bath at 0° C. for 60 minutes to graft-polymerize acrylamide onto the surface of the lens base material (Samples Nos. 1 to 6). In addition, for comparison with the conventional method, 10 wt% without crosslinking agent was added.
A sample was prepared using an aqueous acrylamide solution. (Comparative Examples 1 to 6) The polymerization conditions at this time were exactly the same as those for the samples in which a crosslinking agent was added. In addition, the treated lenses were rubbed 1,000 times with the palm of the hand sprinkled with detergent to perform an abrasion resistance test. Graft polymer peeling was evaluated by examining the change in contact angle between the lens surface before and after rubbing. The contact angle was measured by the dripping method, and water was used as the solvent. These results are listed in Table 2.

[0037]

[Table 2]

As is clear from Tables 1 and 2, the increase in contact angle after rubbing was significantly suppressed by adding the crosslinking agent, and the water wettability of the lens surface was maintained. That is, by crosslinking the acrylamide polymer with N,N'-methylenebisacrylamide, the adhesion strength between the lens base material and the graft polymer was increased, and the abrasion resistance of the graft lens surface was able to be improved.

Although the embodiments of the present invention have been explained using fluoroalkyl-containing contact lenses, similar results can be obtained with hard contact lenses of other compositions and soft contact lenses such as silicone rubber. ing.

Furthermore, similar results were obtained for surface treatments of polyethylene film, polypropylene, polyvinyl chloride, polyvinylidene chloride, acetate, polyester, polyvinyl alcohol, polystyrene, polycarbonate, and various other polymeric materials.

In addition, the above-mentioned resins can be applied to various packaging materials, agricultural water retaining materials, and medical products such as artificial organs.

In the examples of the present invention, acrylamide was used as a hydrophilic monomer, and N,N'-
The explanation was given using methylene bisacrylamide as an example, but
Other hydrophilic monomers including, but not limited to, 2-hydroxyethyl methacrylate, polyvinyl alcohol,
It was confirmed that similar results could be obtained using N-vinylpyrrolidone, polyethylene oxide, dimethylacrylamide, and the like. Furthermore, acrylates such as glycerin diacrylate and trimethylolpropane triacrylate, and methacrylates such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate may be used as crosslinking agents. Similar results were obtained.

[0043]

[Effects of the Invention] As described above, according to the invention, a graft polymer is produced by adding a crosslinking agent such as N,N'-methylenebisacrylamide to a polymerization system consisting of an aqueous solution of a hydrophilic monomer such as acrylamide. has a crosslinked structure, which increases the adhesion strength to the lens base material and dramatically improves abrasion resistance. This has the effect that the water wettability of the contact lens can be maintained for a long period of time. Therefore, the present invention can be said to be a very effective method for producing contact lenses that are comfortable to wear.

Claims (1)

[Claims] 1. A siloxy-substituted ester of acrylic acid or methacrylic acid having the general formula: [Image Omitted] Fluoroalkyl-substituted acids ([Chemical formula 2]), polyfluoroalkylsiloxy-substituted esters of acrylic acid or methacrylic acid represented by the following general formula ([Chemical formula 3]), acrylic acids represented by the following general formula ([Chemical formula 3]) methacrylic)oxyalkylsilanol ( [Chemical formula 4] ), polyacrylic (methacrylic) represented by the following general formula
Oxyalkyl polysiloxane (Chemical formula 5), fluorine-containing siloxanyl methacrylate (Chemical formula 6) represented by the following general formula, fluorine-containing acrylic acid or methacrylic acid ester monomer represented by the following general formula ( [Chemical 7] ), a fluorine-containing acrylic acid or methacrylic acid ester monomer represented by the following general formula [Chemical 8] ), a fluorine-containing diacrylate or dimethacrylate monomer ( [ The raw material is a polymer of an ester compound of acrylic acid or methacrylic acid, which is a copolymer containing at least one of the following: In a contact lens manufacturing method comprising (a) discharging the surface of the contact lens base material under normal pressure or reduced pressure; and (b) graft polymerizing a hydrophilic monomer onto the lens surface. ) A method for producing a contact lens, characterized in that a crosslinking agent is added to the monomer aqueous solution during the process.