JPH0685030B2 - Contact lens material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel contact lens material. More specifically, it relates to a contact lens material having high oxygen permeability.

[Prior Art and Its Problems] Conventionally, glass materials have been mainly used as contact lens materials, but today, polymethyl, which has better machinability and elasticity than glass materials and is lightweight, is used. A contact lens material made of methacrylate is used.

However, since the contact lens material made of polymethylmethacrylate has a low oxygen permeability, there is a problem that when the obtained contact lens is worn for a long time, the corneal tissue is impaired in metabolism.

Therefore, in recent years, research on contact lens materials with excellent oxygen permeability that can replace polymethylmethacrylate,
Developments have been made, for example, those mainly composed of silicone rubber such as polydimethylsiloxane, and those obtained by introducing a vinyl polymerization group into (poly) organosiloxane and then polymerizing it with other vinyl monomer.

Although a contact lens material mainly composed of silicone rubber such as polydimethylsiloxane has excellent oxygen permeability, it exhibits water repellency and is therefore usually used after being subjected to a discharge treatment or the like.

However, even if the hydrophilic treatment as described above is applied, the hydrophilicity decreases during use and the material is flexible, so that the phenomenon of adsorption to the eye is observed, which causes corneal damage. There is a problem.

Introducing a vinyl polymerizable group into (poly) organosiloxane,
Oxygen permeability of those polymerized with other vinyl monomers is mainly due to the organosiloxane moiety, so the oxygen permeability is lower than that of silicone rubber, but the oxygen permeability of the acrylic resin with high hardness and transparency is It is possible to improve the absorption of oxygen in the cornea when worn as a contact lens, and prevent deterioration of corneal function due to lack of oxygen.

However, in order to give a sufficient oxygen permeability to a contact lens by copolymerizing a (poly) organosiloxane having a vinyl polymer group introduced thereinto with an acrylic monomer,
The monomer must be added in large amounts. As a result, the obtained copolymer has the problems that the machinability during contact lens production is poor and the toughness of the lens is also poor. On the other hand, in order to maintain the hardness that can withstand machining during lens manufacturing, it is not possible to add a large amount of (poly) organosiloxane with a vinyl polymer group introduced. A contact lens material having sufficient oxygen permeability to achieve this cannot be obtained.

[Problems to be Solved by the Invention] Therefore, the present inventors have solved the above-mentioned problems of the prior art, provided the desired hardness and hardness as a hard contact lens, and improved the brittleness of the material. As a result of intensive research to develop a hard contact lens made of, which has higher oxygen permeability than the conventional oxygen permeable hard contact lens, ditertiary butyl fumarate and bis (silicon) The present inventors have completed the present invention by finding the fact that a contact lens material having excellent oxygen permeability and having appropriate mechanical strength can be obtained when a copolymer containing a contained alkyl) fumarate as an essential monomer component is used. Came to do.

[Means for Solving Problems] That is, the present invention provides formula (I): Ditertiary butyl fumarate represented by and general formula (II): (In the formula, m and n are 1 or 3; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are methyl groups or And a fumaric acid diester represented by the formula (1).

Examples Formula (I) used in the present invention: Ditertiary butyl fumarate (hereinafter referred to as Dt
BF) is a monomer that is extremely easily homopolymerized among fumarate compounds, and its homopolymer exhibits some oxygen permeability, but is extremely hard and brittle.

On the other hand, the general formula (II): (In the formula, m and n are 1 or 3; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are methyl groups or Fumarate diester (hereinafter referred to as DSiA)
F) does not substantially homopolymerize, but is a component for easily copolymerizing with DtBF to obtain a contact lens material having excellent oxygen permeability, transparency, and appropriate mechanical strength.

Examples of the DSiAF include bis (3- (trimethylsilyl) propyl) fumarate, bis (3- (pentamethyldisiloxanyl) propyl) fumarate, bis (3-
(1,3,3,3-tetramethyl-1- (trimethylsilyl)
(Oxy) disiloxanyl) propyl) fumarate, bis (3- (3,3,3-trimethyl-1,1-bis ((trimethylsilyl) oxy) disiloxanyl) propyl) fumarate, (3- (trimethylsilyl) propyl) (3- ( Pentamethyldisiloxanyl) propyl) fumarate, bis ((pentamethyldisiloxanyl) methyl) fumarate, etc., and one or more of these may be used in an amount of 5 to 100 parts by mol of the total amount of the monomer. It is used after being adjusted to 50 parts by mol, preferably 20 to 50 parts by mol. If the amount used is less than 5 parts by mole, the oxygen permeability will decrease.
Further, when it exceeds 50 parts by mole, DSiAF does not substantially homopolymerize, and as a result of remaining as a monomer, the degree of polymerization and the rate of polymerization decrease. From the viewpoint of polymerization rate, the general formula (II)
A DSiAF in which both m and n are 3 is preferably used.

It is also possible to copolymerize by adding a fumaric acid diester other than the above, and for example, bis (trifluoroethyl) fumarate is preferably used, but the amount used is 0 to 100 parts by mol of the total amount of the monomers. It is preferably 45 parts by mole, especially 0 to 30 parts by mole. When the amount used exceeds 45 parts by mole, the transparency of the produced polymer is lost and the monomer does not substantially homopolymerize, and as a result of remaining as a monomer, the degree of polymerization and the rate of polymerization decrease.

In the copolymer according to the present invention, in addition to the fumaric acid diester as described above, various monomers can be further used as a copolymerization component to modify the properties of the copolymer for various purposes. .

A crosslinkable monomer is effective for the purpose of stabilizing the specifications and shape of the contact lens such as size and power (frequency) and improving chemical resistance. Specific examples of the crosslinkable monomer include diallyl fumarate, allyl methacrylate, allyl acrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, divinylbenzene, and the like. It is preferable to use one or more selected from these.
Also, the amount used is the total monomer mixture to be copolymerized.
It is preferably in the range of about 0 to 20 parts by mol with respect to 100 parts by mol.

In order to impart hydrophilicity to the obtained copolymer and obtain a hard contact lens having good wettability with water, it is preferable to use a hydrophilic monomer. Examples of the hydrophilic monomer include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, N-vinylpyrrolidone and 3-
Methyl-1-buten-3-ol and the like can be mentioned, and it is preferable to use one or more selected from these. Further, the amount used is preferably in the range of about 0 to 20 parts by mole based on 100 parts by mole of the total monomer mixture used for the copolymerization. If a large amount of these hydrophilic monomers is used in an amount exceeding the above range, the oxygen permeability will decrease, which is not preferable.

Instead of or in addition to the use of the hydrophilic monomer, for example, the obtained hard contact lens is subjected to discharge treatment such as corona discharge or plasma discharge, or the hydrophilic monomer is graft-polymerized after the discharge treatment, or hydrochloric acid or By treating with a strong acid such as nitric acid, it is possible to impart effective hydrophilicity to the surface.

Further, in the present invention, a monomerized dye such as Seikagen-0-Real Black (manufactured by Dainichiseika Co., Ltd.) or 2-hydroxy-5-acryloxyphenyl-2-hydroxybenzo may be used, if necessary. Monomerized UV absorbers such as triazoles can also be used. These are preferably used in an amount of 5% by weight or less in order to maintain high oxygen permeability with respect to the total amount of monomers.

Examples of the method of copolymerizing the monomer mixture include a method of heating the monomer mixture by a conventional radical polymerization method in a temperature range of 50 to 110 ° C. to perform the copolymerization. Examples of the polymerization initiator that can be used include benzoyl peroxide, azobisisobutyronitrile, azobisdimethylvaleronitrile and the like, and one or more of them are selected and used. In addition, the amount used is preferably 0.01 to 1.0 part by mol based on 100 parts by mol of the total amount of the monomers.

The molding method using the monomer mixture as a contact lens can be carried out by a usual method. For example, the copolymerization reaction of the above-mentioned monomer mixture is carried out in a mold corresponding to the shape of the contact lens to directly form the shape of the contact lens, and if necessary, this is mechanically, for example, finished by cutting or polishing. can do.
In addition, after performing copolymerization in a suitable mold or container to form a block-shaped, plate-shaped or round bar-shaped material, it is molded into a contact lens having a desired shape by an ordinary mechanical processing method such as cutting or polishing. Good.

Alternatively, the polymer obtained by the above method may be dissolved in an appropriate solvent, and the obtained solution may be poured into a mold to remove the solvent for molding, or the molded product may be machined. It is also possible, and in this case, the oxygen permeability coefficient is slightly improved as compared with the molding method which does not use a solvent.

The contact lens thus obtained has more excellent oxygen permeability than the conventional oxygen permeable hard contact lens, and has appropriate mechanical strength.

Next, the contact lens material of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 55 mol part of ditertiary butyl fumarate, bis (3-
(3,3,3-Trimethyl-1,1-bis ((trimethylsilyl) oxy) disiloxanyl) propyl) fumarate 45
A mol part and 0.1 mol part of benzoyl peroxide as a polymerization initiator were placed in a glass test tube, and the pressure was reduced (10 ⁻³ mmHg) and sealed, and polymerization was carried out at 70 ° C. for 24 hours. Then, the container was opened, the polymer was taken out, and further heated at 100 ° C. for 3 hours. The colorless and transparent copolymer thus obtained was machined by cutting and polishing to obtain a hard contact lens.

The oxygen permeability coefficient was measured on a test piece having a diameter of 15 mm and a thickness of 0.2 mm in a 0.9% physiological saline solution at 35 ° C. using a Seikaken film oxygen permeability meter.

As a result, the oxygen permeability coefficient was 117.0 × 10 ^-10 [(cm ³ (ST
P) · cm) / (cm ² · sec · cmHg)].

Example 2 Ditertiary butyl fumarate and bis (3- (3,3,3
-Trimethyl-1,1-bis ((trimethylsilyl) oxy) disiloxanyl) propyl) fumarate was used in the same manner as in Example 1 except that the compounding ratio with 80 parts: 20 parts by mole was changed. I got a hard contact lens. As a result, the oxygen permeability coefficient was 69.2 × 10 ^-10 [(cm ³
(STP) · cm) / (cm ² · sec · cmHg)].

Examples 3-12 Ditertiary butyl fumarate, bis (3- (3,3,3
-Trimethyl-1,1-bis ((trimethylsilyl) oxy) disiloxanyl) propyl) fumarate, bis (3
-Trimethylsilyl) propyl) fumarate, bis (2,
Hard contact lenses were prepared in the same manner as in Example 1 except that 2,2-trifluoroethyl) fumarate was adjusted to have the composition shown in Table 1, and the oxygen permeability coefficient was measured.

The results are also shown in Table 1.

EFFECTS OF THE INVENTION The contact lens material of the present invention contains ditertiary butyl fumarate exhibiting oxygen permeability and fumaric acid diester exhibiting excellent oxygen permeability as well as transparency and appropriate mechanical strength as essential components. Therefore, there is an effect that it is possible to obtain a contact lens exhibiting excellent oxygen permeability and having appropriate mechanical strength.

Claims (1)

[Claims] 1. Formula (I): Ditertiary butyl fumarate represented by and general formula (II): (In the formula, m and n are 1 or 3; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are methyl groups or And a fumaric acid diester represented by the formula (1).