CA1293577C - Hydrophilic copolymer suitable for contact lenses and medical application and a method for producing thereof - Google Patents
Hydrophilic copolymer suitable for contact lenses and medical application and a method for producing thereofInfo
- Publication number
- CA1293577C CA1293577C CA000517427A CA517427A CA1293577C CA 1293577 C CA1293577 C CA 1293577C CA 000517427 A CA000517427 A CA 000517427A CA 517427 A CA517427 A CA 517427A CA 1293577 C CA1293577 C CA 1293577C
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- Prior art keywords
- diethylene glycol
- methacrylate
- water
- hydrophilic copolymer
- mixture
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-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/041—Lenses
- G02B1/043—Contact lenses
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
- C08F220/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
- C08F220/282—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety and containing two or more oxygen atoms
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- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Materials For Medical Uses (AREA)
- Eyeglasses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
A hydrophilic copolymer suitable for the manufacture of contact lenses and other medical applications. This copolymer is prepared by copolymeriza-tion of 70 - 99.5 wt.% of diethylene glycol monomethacrylate with 0.5 to 30 wt.% of vinyl monomers selected from the group consisting of esters and amides of methacrylic acid and acrylic acid, in the presence of at least one radical initiator and of 0.01 - 2 wt.% of a crosslinking agent con-taining at least two olefinic double bonds in its molecule.
A hydrophilic copolymer suitable for the manufacture of contact lenses and other medical applications. This copolymer is prepared by copolymeriza-tion of 70 - 99.5 wt.% of diethylene glycol monomethacrylate with 0.5 to 30 wt.% of vinyl monomers selected from the group consisting of esters and amides of methacrylic acid and acrylic acid, in the presence of at least one radical initiator and of 0.01 - 2 wt.% of a crosslinking agent con-taining at least two olefinic double bonds in its molecule.
Description
3S~7 The present invention relates to a hydrophilic copolymer suitable for the manufacture of contact lenses and for other medical applications, and to a method o~ preparing it.
5Water-swelling elastomers having various equilib-rium content of water are already known and used for the production of soft hydrophilic contact lenses and also for various medical purposes. Poly(2-hydroxyethyl methacrylate) (hereinafter referred to as poly-HEMA) have proved to be 10particularly suitable for applications where good mechanical properties are required and a water content about 40 wt.~ is sufficient. However, some applications need highly swelling materials (e.g. contact lenses for permanent wearing), often even with a lower shear modulus but a sufficient elongation.
15The known hydrophilic polymers with a high swelling capacity usually have mechanical properties unsuitable to such extent, so that they cannot be used for this purpose. Therefore, lightly crosslinked copolymers of highly hydrophilic N-vinylpyrrolidone with hydrophobic alkyl 20methacrylate have been developed (see ~ritish Pat. no.
1,514,810), which have more suitable mechanical properties in addition to a high swelling capacity, but contain an un-~; desirable extractable portion. A homologue of 2-hydroxy-ethyl methacrylate, diethylene glycol methacrylate (herein-25after referred to as DEGMA; 2,2'-oxydiethanol monometh-acrylate) gives polymers strongly swelling due to its ether oxygen atom in the ester chain. However, these polymers do not exhibit suitable mechanical properties even in a crosslinked state and cannot be used for some applications.
30The present invention proposes a new kind of hydrophilic copolymer which overcomes the above mentioned disadvantages.
More particularly, the invention proposes a new hydrophilic copolymer suitable particularly for contact lX~3~ii X7 lenses but also for other medical applications, which has a water con-tent of at least 48% and is prepared, according to the invention, by copolymerization of 70 to 99.5 wt.% of diethylene glycol methacrylate (DEGMA; 2,2'-oxydiethanol monomethacrylate), with 0.5 to 30 wt.~ of at least one non-hydrophilic vinyl monomer selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, dodecyl me-thacrylate and ethoxyethyl methacrylate, in the presence of 0.01 to 2% wt of a crosslinking agent having at least two olefinic double bonds in its molecule, and of at least one radical initiator.
The radical initiator can be selected from the group comprising azo compounds, peroxides, peroxocarbonates, peroxosulEates, photoinitiators based on benzoin ethers and their derivatives, and initiation redox systems, advantageously peroxosulfate - disulfite, peroxosultate -alkalamines, benzoyl peroxide - alkylamines, and uses in the concentration 0.01 to 3 wt.%.
The copolymerization is preferably carried out in the presence of at least one polar solvent, which can advantageously be glycerol, glycols and their derivatives, water, dimethylformamide, dimethylsulfoxide, dimethyl-acetamide, diacetine, isopropylalcohol, or their mixtures.
In accordance with the invention, the copolymeri-zation of diethylene glycol methacrylate with a selectedester or amide of methacrylic acid or acrylic acid i8 carried out in the presence of a crosslinkin~ agent which can be selected amongst diethylene glycol dimethacrylate, -triethylene glycol dimethacrylate and ethylene glycol dimethacrylate or an arbitrary diester of .methacrylic acid or acrylic acid with a corresponding alkylene glycol, methylene-bis-acrylamide, ethylene-bis-methacrylamide, hexa-. -- 2 , ,~
., 3~77 methylene-bis-methacrylamide, and others. In any case at least three (3) components have to enter the polymeriza-tion, two of which are monoesters, the third one being the crosslinking agent of course, one of these monoesters is diethylene glycol monomethacrylate.
Diethylene glycol monomethacrylate contains diethylene glycol dimethacrylate from its synthesis. This diester contained in the starting monomer may act as cross-linking component, or becomes a part of a mixture of crosslinking agents. Alternatively, it may be removed or decxeased to a minimum in diethylene glycol methacrylate, if another crosslinking system is used.
At the above specified content of monoesters and within the aforesaid concentration of a diester or diesters of acrylic acid or methacrylic acid, or amide or amides of acrylic acid or methacrylic acid, the resulting hydrophilic terpolymer of higher copolymer attains such mechanical properties that it can be used for the preparation of con-tact lenses or for other medical purposes. The content of 20 water in the obtained final three-dimensional hydrogel con-tinuously increases with the increasing content of the DEGMA
component in the mixture.
In accordance with the invention hydrogels with suitable mechanical properties at the equilibrium water content as high as 50 to 70 wt.% are obtained.
The copolymers according to the invention have much better mechanical properties than the homopolymer of DEGMA. They have properties often comparable with the mechanical properties of HEMA polymers and they are really suitable for the above mentioned applications.
The copolymers according to the invention are virtually free of water-soluble extractables and do not contain ionogenic groups in their structure. Therefore, one can expect lower deposits of eye proteins with contact ~3~ 7 lenses made from these copolymers, as compared to what may be obtained with copolymers containing, e.g., methacrylic acid or its salts. Thus, the copolymers according to the invention secure a sufficiently high equilibrium content of water in the resulting gel at the retained optical and mechanical properties, so that they may be used for the production of contact lenses for permanent wearing.
The invention will be illustrated in greater detail in the following, non restrictive examples.
A mixture of 90 wt.% of diethylene glycol methacrylate (further DEGMA) and 10 wt.% of butyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of mono-mers for 16 hours at 60C. The resulting material contained after swelling 59 wt.% of water and had G = 0.100 MPa, elon-gation 112% and strength 0.185 MPa.
A mixture of 95% of DEGMA and 5 wt.% of butyl methacrylate containing 0.5 wt.% of diethylene glycol di-methacrylate was polymerized with 0.2 wt.% azobisisobutyro-nitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 68 wt.% of water at G = 0.1 MPa, elongation 129% and strength 0.215 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of butyl 1~93577 methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70% with 30 wt.%
of 2-hydroxyethyl methacrylate (further HEMA). This mixture was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 54 wt.~ of water at G = 0.139 MPa, elongation 165%, strength 0.320 MPa, and Kv = 1.35 (Kv is the coefficient of linear expansion during the swelling in H2O).
A mixture of 95 wt.% DEGMA and 5 wt.% of butyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.~ of ethylene glycol dimeth-acrylate was mixed in the amount of 60 wt.~ with 40 wt.%
HEMA. This mixture was polymerized with 0.2 wt.% of azobi-sisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 49 wt.% of water at G = 0.365 MPa, strength 0.235 MPa, and Kv = 1.31.
A mixture of 95% DEGMA and 5 wt.% of butyl methacrylate containing 0.6 wt.% of diethylene glycol di-methacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 50 wt.% with 50 wt.% HEMA. This mixture was polymerized with 0.2 wt.% of azobisisobutyro-nitrile related to the total amount of mono-mers for 16 hours at 60C. The resulting material contained after swel-ling 48 wt.% of water at G = 0.548 MPa and Kv = 1.38.
~93S~
A mixture of 95 wt.~ DEGMA and S wt.% of 2-ethoxy-ethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained after swel-ling 69 wt.% of water at G = 0.077 MPa and Kv = 1.S6.
.
A mixture of 90 wt.% DEGMA and 10 wt.% of 2-ethoxyethyl methacrylate containing 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total amount of monomers for 16hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.087 MPa, elongation 146% and strength 0.194 MPa.
A mixture of 80 wt.% DEGMA and 20 wt.% of 2-ethoxyethyl methacrylate containing 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.% of triethylene glycol ; dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 60 wt.% of water at G = 0.178 and Kv = 1.41.
; 30 A mixture of 70 wt.% DEGMA and 30 wt.% of 2-ethoxyethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight o~ mono-mers for 16 hours at 60C. The resulting material contained after swelling ~9 wt.~ of water at G = 0.181 MPa and Kv =
1.28.
EXAMPLE lO
A mixture of 97 wt.% DEGMA and 3 wt.~ of N-tert-butylacrylamide containing 0.6 wt.% of diethylene glycol ~ dimethacrylate and 0.15 wt.% of ethylene glycol dimeth-;~ acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 62 wt.% of water at G = 0.170 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of N-tert-butylacrylamide containing 0.5 wt.% of diethylene glycoldimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 68 wt.% of water at G = 0.108 PMa.
A mixture of 95 wt.~ DEGMA and 5 wt.% of dodecyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.4 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.118 MPa and Kv = l.Sl.
~35~
A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.110 MPa and Kv = 1.51.
, A mixture of 90 wt.% of DEGMA and 10 wt.% of dodecyl methacrylate containing 0.6 wto% of diethylene glycol dimethacrylate and 0.15 wt.% ethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 62 wt.% of water at G = 0.120 MPa and Kv = 1.43.
A mlxture of 80 wt.% DEGMA and 20 wt.% of dodecyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-~; butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 55 wt.% of water at G = 0.125 MPa.
;~ ' ~`
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimeth-.
~3S77 acrylate and 0.3 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 66 wt.% of water at G = 0.117 MPa and Kv = 1,51.
A mixture of 90 wt.% DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of mnomers for 16 hours at 60C. The resulting material contained after swel-ling 55 wt.% of water at G = 0.395 MPa and Kv = 1.36.
!
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.1~ wt.% of diethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyro-nitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 67 wt.~ of water at G = 0.110 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.6 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 63 wt.% of water at G = 0.132 MPa.
: _ g _ ~93S77 A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl meth-acrylate containing 0.15 wt.% of ethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 6 wt.~ of water at G = 0.095 MPa.
; 10 EXAMPLE 21 - A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl methacrylate containing 0.6 wt.% of ethylene glycol dimeth-acrylate and 0.6 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.~ of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 65 wt.% of water at G = 0.117 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.% of tert-butyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 55.3 wt.~ of water at G = O . 390 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.% of diethylene glycol ~; dimethacrylate was polymerized with 0.2 wt.~ of ammonium peroxosulfate related to the total amount of monomers for 1 -~2~3577 hour at 78C. The resulting material contained after swelling 55.1 wt.~ of water at G = 0.390 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.6 wt.% of diethylene glycol dimeth~crylate and 0.15 wt.% of ethylane glycol dimeth-acrylate was polymerized with 0.5 wt.% benzoin ethyl ether related to the total weight of monomers for 15 min under UV
radiation. The resulting material contained after swelling 55 wt.% of water at G = 0.395 MPa.
A mixture of 90 wt.% DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.5 wt.~ of benzoin methyl ether related to the total weight of monomers for 15 min under UV radiation. The resulting material contained ; after swelling 55.6 wt.% of water at G = 0.385 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.~ of 2-ethoxy-ethyl methacrylate containing 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimeth-acrylate was polymerized with 0.1 wt.% of diisopropyl per-oxocarbonate related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 69.1 wt.% of water at G = 0.077 MPa.
- ~LZ~3~77 A mixture of 95 wt.% of DEGMA and 5 wt.% of 2-ethoxyethyl methacrylate containing 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of ammonium peroxosulfate related to the total weight of monomers for 1 hour at 78C. The resulting material contained after swel-ling 68.8 wt.% of water at G = O . 079 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of 2-ethoxyethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total weight of monomers for 15 min under UV radiation. The resulting material con-tained after swelling 69 wt.% of water at G = 0.077 MPa.
A mixture of 95 wt.~ DEGMA and 5 wt.% of 2-ethoxy-ethyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacry-late was polymerized with 0.5 wt.% of benzoin methyl ether related to the total weight of monomers for 15 min under UV
radiation. The resulting material contained after swelling 69 wt.% of water at G = 0.078 MPa.
5Water-swelling elastomers having various equilib-rium content of water are already known and used for the production of soft hydrophilic contact lenses and also for various medical purposes. Poly(2-hydroxyethyl methacrylate) (hereinafter referred to as poly-HEMA) have proved to be 10particularly suitable for applications where good mechanical properties are required and a water content about 40 wt.~ is sufficient. However, some applications need highly swelling materials (e.g. contact lenses for permanent wearing), often even with a lower shear modulus but a sufficient elongation.
15The known hydrophilic polymers with a high swelling capacity usually have mechanical properties unsuitable to such extent, so that they cannot be used for this purpose. Therefore, lightly crosslinked copolymers of highly hydrophilic N-vinylpyrrolidone with hydrophobic alkyl 20methacrylate have been developed (see ~ritish Pat. no.
1,514,810), which have more suitable mechanical properties in addition to a high swelling capacity, but contain an un-~; desirable extractable portion. A homologue of 2-hydroxy-ethyl methacrylate, diethylene glycol methacrylate (herein-25after referred to as DEGMA; 2,2'-oxydiethanol monometh-acrylate) gives polymers strongly swelling due to its ether oxygen atom in the ester chain. However, these polymers do not exhibit suitable mechanical properties even in a crosslinked state and cannot be used for some applications.
30The present invention proposes a new kind of hydrophilic copolymer which overcomes the above mentioned disadvantages.
More particularly, the invention proposes a new hydrophilic copolymer suitable particularly for contact lX~3~ii X7 lenses but also for other medical applications, which has a water con-tent of at least 48% and is prepared, according to the invention, by copolymerization of 70 to 99.5 wt.% of diethylene glycol methacrylate (DEGMA; 2,2'-oxydiethanol monomethacrylate), with 0.5 to 30 wt.~ of at least one non-hydrophilic vinyl monomer selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, dodecyl me-thacrylate and ethoxyethyl methacrylate, in the presence of 0.01 to 2% wt of a crosslinking agent having at least two olefinic double bonds in its molecule, and of at least one radical initiator.
The radical initiator can be selected from the group comprising azo compounds, peroxides, peroxocarbonates, peroxosulEates, photoinitiators based on benzoin ethers and their derivatives, and initiation redox systems, advantageously peroxosulfate - disulfite, peroxosultate -alkalamines, benzoyl peroxide - alkylamines, and uses in the concentration 0.01 to 3 wt.%.
The copolymerization is preferably carried out in the presence of at least one polar solvent, which can advantageously be glycerol, glycols and their derivatives, water, dimethylformamide, dimethylsulfoxide, dimethyl-acetamide, diacetine, isopropylalcohol, or their mixtures.
In accordance with the invention, the copolymeri-zation of diethylene glycol methacrylate with a selectedester or amide of methacrylic acid or acrylic acid i8 carried out in the presence of a crosslinkin~ agent which can be selected amongst diethylene glycol dimethacrylate, -triethylene glycol dimethacrylate and ethylene glycol dimethacrylate or an arbitrary diester of .methacrylic acid or acrylic acid with a corresponding alkylene glycol, methylene-bis-acrylamide, ethylene-bis-methacrylamide, hexa-. -- 2 , ,~
., 3~77 methylene-bis-methacrylamide, and others. In any case at least three (3) components have to enter the polymeriza-tion, two of which are monoesters, the third one being the crosslinking agent of course, one of these monoesters is diethylene glycol monomethacrylate.
Diethylene glycol monomethacrylate contains diethylene glycol dimethacrylate from its synthesis. This diester contained in the starting monomer may act as cross-linking component, or becomes a part of a mixture of crosslinking agents. Alternatively, it may be removed or decxeased to a minimum in diethylene glycol methacrylate, if another crosslinking system is used.
At the above specified content of monoesters and within the aforesaid concentration of a diester or diesters of acrylic acid or methacrylic acid, or amide or amides of acrylic acid or methacrylic acid, the resulting hydrophilic terpolymer of higher copolymer attains such mechanical properties that it can be used for the preparation of con-tact lenses or for other medical purposes. The content of 20 water in the obtained final three-dimensional hydrogel con-tinuously increases with the increasing content of the DEGMA
component in the mixture.
In accordance with the invention hydrogels with suitable mechanical properties at the equilibrium water content as high as 50 to 70 wt.% are obtained.
The copolymers according to the invention have much better mechanical properties than the homopolymer of DEGMA. They have properties often comparable with the mechanical properties of HEMA polymers and they are really suitable for the above mentioned applications.
The copolymers according to the invention are virtually free of water-soluble extractables and do not contain ionogenic groups in their structure. Therefore, one can expect lower deposits of eye proteins with contact ~3~ 7 lenses made from these copolymers, as compared to what may be obtained with copolymers containing, e.g., methacrylic acid or its salts. Thus, the copolymers according to the invention secure a sufficiently high equilibrium content of water in the resulting gel at the retained optical and mechanical properties, so that they may be used for the production of contact lenses for permanent wearing.
The invention will be illustrated in greater detail in the following, non restrictive examples.
A mixture of 90 wt.% of diethylene glycol methacrylate (further DEGMA) and 10 wt.% of butyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of mono-mers for 16 hours at 60C. The resulting material contained after swelling 59 wt.% of water and had G = 0.100 MPa, elon-gation 112% and strength 0.185 MPa.
A mixture of 95% of DEGMA and 5 wt.% of butyl methacrylate containing 0.5 wt.% of diethylene glycol di-methacrylate was polymerized with 0.2 wt.% azobisisobutyro-nitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 68 wt.% of water at G = 0.1 MPa, elongation 129% and strength 0.215 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of butyl 1~93577 methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70% with 30 wt.%
of 2-hydroxyethyl methacrylate (further HEMA). This mixture was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 54 wt.~ of water at G = 0.139 MPa, elongation 165%, strength 0.320 MPa, and Kv = 1.35 (Kv is the coefficient of linear expansion during the swelling in H2O).
A mixture of 95 wt.% DEGMA and 5 wt.% of butyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.~ of ethylene glycol dimeth-acrylate was mixed in the amount of 60 wt.~ with 40 wt.%
HEMA. This mixture was polymerized with 0.2 wt.% of azobi-sisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 49 wt.% of water at G = 0.365 MPa, strength 0.235 MPa, and Kv = 1.31.
A mixture of 95% DEGMA and 5 wt.% of butyl methacrylate containing 0.6 wt.% of diethylene glycol di-methacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 50 wt.% with 50 wt.% HEMA. This mixture was polymerized with 0.2 wt.% of azobisisobutyro-nitrile related to the total amount of mono-mers for 16 hours at 60C. The resulting material contained after swel-ling 48 wt.% of water at G = 0.548 MPa and Kv = 1.38.
~93S~
A mixture of 95 wt.~ DEGMA and S wt.% of 2-ethoxy-ethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained after swel-ling 69 wt.% of water at G = 0.077 MPa and Kv = 1.S6.
.
A mixture of 90 wt.% DEGMA and 10 wt.% of 2-ethoxyethyl methacrylate containing 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total amount of monomers for 16hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.087 MPa, elongation 146% and strength 0.194 MPa.
A mixture of 80 wt.% DEGMA and 20 wt.% of 2-ethoxyethyl methacrylate containing 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.% of triethylene glycol ; dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 60 wt.% of water at G = 0.178 and Kv = 1.41.
; 30 A mixture of 70 wt.% DEGMA and 30 wt.% of 2-ethoxyethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight o~ mono-mers for 16 hours at 60C. The resulting material contained after swelling ~9 wt.~ of water at G = 0.181 MPa and Kv =
1.28.
EXAMPLE lO
A mixture of 97 wt.% DEGMA and 3 wt.~ of N-tert-butylacrylamide containing 0.6 wt.% of diethylene glycol ~ dimethacrylate and 0.15 wt.% of ethylene glycol dimeth-;~ acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 62 wt.% of water at G = 0.170 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of N-tert-butylacrylamide containing 0.5 wt.% of diethylene glycoldimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 68 wt.% of water at G = 0.108 PMa.
A mixture of 95 wt.~ DEGMA and 5 wt.% of dodecyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.4 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.118 MPa and Kv = l.Sl.
~35~
A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 67 wt.% of water at G = 0.110 MPa and Kv = 1.51.
, A mixture of 90 wt.% of DEGMA and 10 wt.% of dodecyl methacrylate containing 0.6 wto% of diethylene glycol dimethacrylate and 0.15 wt.% ethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 62 wt.% of water at G = 0.120 MPa and Kv = 1.43.
A mlxture of 80 wt.% DEGMA and 20 wt.% of dodecyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-~; butyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 55 wt.% of water at G = 0.125 MPa.
;~ ' ~`
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimeth-.
~3S77 acrylate and 0.3 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 66 wt.% of water at G = 0.117 MPa and Kv = 1,51.
A mixture of 90 wt.% DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of mnomers for 16 hours at 60C. The resulting material contained after swel-ling 55 wt.% of water at G = 0.395 MPa and Kv = 1.36.
!
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.1~ wt.% of diethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyro-nitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 67 wt.~ of water at G = 0.110 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of tert-butyl methacrylate containing 0.6 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisiso-butyronitrile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 63 wt.% of water at G = 0.132 MPa.
: _ g _ ~93S77 A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl meth-acrylate containing 0.15 wt.% of ethylene glycol dimeth-acrylate was polymerized with 0.2 wt.% of azobisisobutyroni-trile related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 6 wt.~ of water at G = 0.095 MPa.
; 10 EXAMPLE 21 - A mixture of 95 wt.% DEGMA and 5 wt.% of dodecyl methacrylate containing 0.6 wt.% of ethylene glycol dimeth-acrylate and 0.6 wt.% of diethylene glycol dimethacrylate was polymerized with 0.2 wt.~ of azobisisobutyronitrile related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swelling 65 wt.% of water at G = 0.117 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.% of tert-butyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total weight of monomers for 16 hours at 60 C. The resulting material contained after swelling 55.3 wt.~ of water at G = O . 390 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.% of diethylene glycol ~; dimethacrylate was polymerized with 0.2 wt.~ of ammonium peroxosulfate related to the total amount of monomers for 1 -~2~3577 hour at 78C. The resulting material contained after swelling 55.1 wt.~ of water at G = 0.390 MPa.
A mixture of 90 wt.~ DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.6 wt.% of diethylene glycol dimeth~crylate and 0.15 wt.% of ethylane glycol dimeth-acrylate was polymerized with 0.5 wt.% benzoin ethyl ether related to the total weight of monomers for 15 min under UV
radiation. The resulting material contained after swelling 55 wt.% of water at G = 0.395 MPa.
A mixture of 90 wt.% DEGMA and 10 wt.~ of tert-butyl methacrylate containing 0.5 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.5 wt.~ of benzoin methyl ether related to the total weight of monomers for 15 min under UV radiation. The resulting material contained ; after swelling 55.6 wt.% of water at G = 0.385 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.~ of 2-ethoxy-ethyl methacrylate containing 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimeth-acrylate was polymerized with 0.1 wt.% of diisopropyl per-oxocarbonate related to the total weight of monomers for 16 hours at 60C. The resulting material contained after swel-ling 69.1 wt.% of water at G = 0.077 MPa.
- ~LZ~3~77 A mixture of 95 wt.% of DEGMA and 5 wt.% of 2-ethoxyethyl methacrylate containing 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% of ammonium peroxosulfate related to the total weight of monomers for 1 hour at 78C. The resulting material contained after swel-ling 68.8 wt.% of water at G = O . 079 MPa.
A mixture of 95 wt.% DEGMA and 5 wt.% of 2-ethoxyethyl methacrylate containing 0.5 wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total weight of monomers for 15 min under UV radiation. The resulting material con-tained after swelling 69 wt.% of water at G = 0.077 MPa.
A mixture of 95 wt.~ DEGMA and 5 wt.% of 2-ethoxy-ethyl methacrylate containing 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacry-late was polymerized with 0.5 wt.% of benzoin methyl ether related to the total weight of monomers for 15 min under UV
radiation. The resulting material contained after swelling 69 wt.% of water at G = 0.078 MPa.
Claims (7)
1. A hydrophilic copolymer having a water content of at least 48% suitable for the manufacture of contact lenses and other medical applications, said copolymer being prepared by copolymerization of 70 to 99.5 wt.% of diethylene glycol monomethacrylate with 0.5 to 30 wt.% of at least one non-hydrophilic vinyl monomer selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, dodecyl methacrylate and ethoxyethyl methacrylate, said copolymerization being carried out in the presence of 0.01 to 2 wt.% of a crosslinking agent having at least two olefinic double bonds in its molecule, and of at least one radical initiator.
2. The hydrophilic copolymer according to claim 1, wherein said crosslinking agent is selected from the group consisting of multifunctional esters and amides of acrylic acid and methacrylic acid.
3. The hydrophilic copolymer according to claim 1 or 2, wherein said at least one radical initiator is selected from the group consisting of azo compounds, peroxides, peroxocarbonates, peroxosulfates, photoinitiators based on benzoin ethers and their derivatives, and initiation redox systems.
4. The hydrophilic copolymer according to claim 1, 2 or 3, wherein said copolymerization is carried out in the presence of at least one polar solvent.
5. The hydrophilic copolymer according to claim 1 or 2, wherein said copolymerization. is carried out in the presence of at least one polar solvent selected from the group consisting of glycerol, glycols and their derivatives, water, dimethylformamide, dimethylsulfoxide, dimethylacetamide, diacetine, isopropylalcohol and their mixtures.
6. A method for the production of the hydrophilic copolymer according to claim 1, comprising the step of copolymerizing at least 70 wt.% of diethylene glycol monomethacrylate with no more than 30 wt.% of at least one non-hydrophilic vinyl monomer selected from the group comprising methyl methacrylate, tert-butyl methacrylate, dodecyl methacrylate and ethoxyethyl methacrylate, in the presence of 0.01 to 2 wt.% of a crosslinking agent having at least two olefinic double bonds, and of at least one radical initiator.
7. The method according to claim 7, wherein the copolymerization is carried out in the presence of a polar solvent or a mixture of polar solvents.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CS856341A CS256437B1 (en) | 1985-09-04 | 1985-09-04 | Hydrophilic copolymer especially for contact lenses and medicinal application and method of its production |
| CSPV6341-85 | 1985-09-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1293577C true CA1293577C (en) | 1991-12-24 |
Family
ID=5410226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000517427A Expired - Fee Related CA1293577C (en) | 1985-09-04 | 1986-09-03 | Hydrophilic copolymer suitable for contact lenses and medical application and a method for producing thereof |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS62116616A (en) |
| CA (1) | CA1293577C (en) |
| CS (1) | CS256437B1 (en) |
| DE (1) | DE3630187A1 (en) |
| FR (1) | FR2586690B1 (en) |
| GB (1) | GB2181440B (en) |
| IT (1) | IT1197469B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU711609B2 (en) * | 1994-08-05 | 1999-10-14 | West Pharmaceutical Services Cornwall Limited | Container for moisture-sensitive material |
| EP0937648A3 (en) * | 1994-08-05 | 2001-01-17 | West Pharmaceutical Services Cornwall Limited | Container for moisture-sensitive material |
| DE10035119A1 (en) | 2000-07-19 | 2002-01-31 | Basf Ag | Partially branched polymers |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB814009A (en) * | 1956-04-24 | 1959-05-27 | Otto Wichterle | Three-dimensional hydrophilic high polymeric articles |
| DE1495381B2 (en) * | 1963-09-07 | 1971-06-24 | Czeskoslovenska akademie ved , Prag | METHOD FOR MANUFACTURING CONTACT LENSES OR CONTACT LENS BLOCKS FROM SWELLABLE HYDROGELS |
| CS150484B1 (en) * | 1969-03-04 | 1973-09-04 | ||
| CS158458B1 (en) * | 1972-05-02 | 1974-11-25 | ||
| GB1424587A (en) * | 1973-02-27 | 1976-02-11 | Union Optics Corp | Copolymers and hydrogels of unsaturated esters |
| JPS543738B2 (en) * | 1974-05-27 | 1979-02-26 | ||
| JPS52102748A (en) * | 1976-02-25 | 1977-08-29 | Hoya Lens Co Ltd | Method of manufacturing soft contact lens |
| US4123407A (en) * | 1976-11-26 | 1978-10-31 | American Optical Corporation | Hydrophilic contact lens |
| EP0100381B1 (en) * | 1982-07-30 | 1986-09-17 | Hoya Corporation | Soft contact lens |
| CS252224B1 (en) * | 1985-07-31 | 1987-08-13 | Otto Wichterle | Hydrophilic copolymer suitable eapecially for contact lenses and medicinal utilization and method of its producion |
-
1985
- 1985-09-04 CS CS856341A patent/CS256437B1/en unknown
-
1986
- 1986-09-03 IT IT8621585A patent/IT1197469B/en active
- 1986-09-03 GB GB8621275A patent/GB2181440B/en not_active Expired - Fee Related
- 1986-09-03 CA CA000517427A patent/CA1293577C/en not_active Expired - Fee Related
- 1986-09-03 FR FR868612372A patent/FR2586690B1/en not_active Expired - Fee Related
- 1986-09-04 DE DE19863630187 patent/DE3630187A1/en not_active Withdrawn
- 1986-09-04 JP JP61206927A patent/JPS62116616A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| GB2181440A (en) | 1987-04-23 |
| JPS62116616A (en) | 1987-05-28 |
| IT1197469B (en) | 1988-11-30 |
| CS634185A1 (en) | 1987-09-17 |
| FR2586690B1 (en) | 1991-11-29 |
| DE3630187A1 (en) | 1987-03-05 |
| FR2586690A1 (en) | 1987-03-06 |
| GB2181440B (en) | 1990-04-25 |
| IT8621585A0 (en) | 1986-09-03 |
| CS256437B1 (en) | 1988-04-15 |
| GB8621275D0 (en) | 1986-10-08 |
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