CA1267492A - Hydrophilic copolymer suitable above all for contact lenses and medical purposes and a method of its preparation - Google Patents
Hydrophilic copolymer suitable above all for contact lenses and medical purposes and a method of its preparationInfo
- Publication number
- CA1267492A CA1267492A CA000514998A CA514998A CA1267492A CA 1267492 A CA1267492 A CA 1267492A CA 000514998 A CA000514998 A CA 000514998A CA 514998 A CA514998 A CA 514998A CA 1267492 A CA1267492 A CA 1267492A
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- Prior art keywords
- mixture
- glycol dimethacrylate
- water
- con
- hema
- Prior art date
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Classifications
-
- 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
- C08F220/20—Esters of polyhydric alcohols or phenols, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate
-
- 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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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Eyeglasses (AREA)
- Materials For Medical Uses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
The invention relates to a hydrophilic copolymer particularly suitable for contact lenses and other medical applications, which copolymer is prepared by copolymeriza-tion of 10 to 90 wt.%, preferably 40 to 80 wt.%, of a monomer of the general formule I
(I)
The invention relates to a hydrophilic copolymer particularly suitable for contact lenses and other medical applications, which copolymer is prepared by copolymeriza-tion of 10 to 90 wt.%, preferably 40 to 80 wt.%, of a monomer of the general formule I
(I)
Description
~26~ 2 Hydrophilic copolymer particular suitable for contact lenses and other medical purposes and method for preparing the same.
The present invention relates to a hydrophilic copolymer particularly suitable for contact lenses and medical applications, and to a method for preparing this hydrophilic copolymer.
Strongly swelling elastomers are known, which are particularly suitable for various medical purposes, for the manufacture of contact lenses and for other applications.
These known elastomers, however, are insuitable for certain applications because of their insufficient mechanical properties. Therefore, weakly crosslinked copolymers of strongly hydrophilic N-vinylpyrrolidone with hydrophobic alkyl methacrylate were developed (see British Patent no.
1,514,810), which exhibit, in addition to high swelling, more convenient mechanical properties. Howeever, these particular copolymers contain an undesirable extractable portion. Moreover, their hydrophobic comonomer, in particular methyl methacrylate, is highly volatile. For this reason, these copolymers cannot be used for monomer casting in open molds, such as, for example, for the production of foils and contact lenses by the method of centrifugal casting. Even the crosslinked triethylene glycol methacrylate, which is known from US Patent no.
3,220,960 and also highly swells, has not sufficient mechanical properties and therefore cannot be used for some applications such as, for example, the manufacture of contact lenses for long-termed wearing. The endeavour is to develop for use in manufacturing lenses, a hydrophilic copolymer which would be highly swelling and would keep suitable mechanical properties, such as tensile strength, elongation and elasticity modulus.
The present invention proposes a hydrophylic copo--- 1 -- , . ' ' .
:~Z~7~
lymer particularly suitable for the manufacture of contact lenses and for other medical purposes, which overcomes all of the above mentioned problems.
The hydrophylic copolymer according to the invention is prepared by copolymerization of 10 - 90 wt.%, preferably 40 - 80 wt.~, of a monomer of the general formula I
CH = C - COO - (CH2CH2O)n CH2 2 (I) where n is 1 or 2, with 90 - 10 wt.~ of 2-hydroxyethyl methacrylate and with 0.01 to 2 wt.% of at least one crosslinking agent having at least two olefinic double bonds, such as, for example, multifunctional esters or amides of acrylic or methacrylic acid, in the presence of at least one radical initiator.
The copolymerization is preferably carried out in the presence of a polar solvent, advantageously in the presence of glycerol, glycols and their derivatives, water, dimethyl-formamide, dimethylsulfoxide, dimethylacetamide, diacetine, isopropanol, or their mixture, with the weight ratio of the solvent to the monomer mixture ranging from 1 : 99 to 50 : 50.
The radical initiator can be selected from the group consisting of azo compounds, peroxides, peroxocarbonates, peroxosulfates, photoinitiators based on benzoin ethers and their derivatives, and initiation redox systems. Advantageously, use will be ~ade of peroxosulate - disulfite, peroxosulfate - alkylamines, and benzoyl peroxide - alkylamines, in a concentration 0.01 - 3 wt.%.
If the copolymerization is carried out in the absence of polar solvent or a mixture of polar solvents a bulk copolymer is obtained. Such a bulk copolymer is particularly useful for applications which require :~26~;~4~?2 mechanical working. But this copolymerization in bulk may be used also for the direct production of some articles.
In the presence of one or more polar solvents, the resulting copolymer contains a suitably chosen amount of solvent and is suitable for casting, e.g. for the centrifugal casting of contact lenses. The sol~ent, which would interfere in the mechanical working mentioned hereinabove, here positively affects the swelling pressures occuring during swelling of the final product.
Copolymers of 2-hydroxyethyl methacrylate with diethylene glycol monomethacrylate and of 2-hydroxyethyl methacrylate with triethylene glycol monomethacrylate are particularly preferred. These copolymers can be prepared in the presence of diethylene glycol dimethacrylate or trimethylene glycol dimethacrylate and ethylene glycol dimethacrylate, or in the presence of only one crosslinking component, which may be an arbitrary diester of methacrylic or acrylic acid with the corresponding alkyl glycol if the starting monomers are completely free of their corresponding diesters originating from their synthesis. Alternatively, the copolymerization can be carried out in the presence of methylene-bis-acrylamide, ethylene-bis-methacrylamide, hexamethylene-bis-methacrylamide, and the like, as crosslinking agents, or in the presence of their combinations, always in such a way that at least three components are entering the polymerization, two of which are monomers and the third one is a crosslinking agent, whereas one of two monoesters is always 2-hydroxyethyl methacrylate and the other monoester is either diethylene glycol monomethacrylate or triethylene glycol monomethacrylate. If
The present invention relates to a hydrophilic copolymer particularly suitable for contact lenses and medical applications, and to a method for preparing this hydrophilic copolymer.
Strongly swelling elastomers are known, which are particularly suitable for various medical purposes, for the manufacture of contact lenses and for other applications.
These known elastomers, however, are insuitable for certain applications because of their insufficient mechanical properties. Therefore, weakly crosslinked copolymers of strongly hydrophilic N-vinylpyrrolidone with hydrophobic alkyl methacrylate were developed (see British Patent no.
1,514,810), which exhibit, in addition to high swelling, more convenient mechanical properties. Howeever, these particular copolymers contain an undesirable extractable portion. Moreover, their hydrophobic comonomer, in particular methyl methacrylate, is highly volatile. For this reason, these copolymers cannot be used for monomer casting in open molds, such as, for example, for the production of foils and contact lenses by the method of centrifugal casting. Even the crosslinked triethylene glycol methacrylate, which is known from US Patent no.
3,220,960 and also highly swells, has not sufficient mechanical properties and therefore cannot be used for some applications such as, for example, the manufacture of contact lenses for long-termed wearing. The endeavour is to develop for use in manufacturing lenses, a hydrophilic copolymer which would be highly swelling and would keep suitable mechanical properties, such as tensile strength, elongation and elasticity modulus.
The present invention proposes a hydrophylic copo--- 1 -- , . ' ' .
:~Z~7~
lymer particularly suitable for the manufacture of contact lenses and for other medical purposes, which overcomes all of the above mentioned problems.
The hydrophylic copolymer according to the invention is prepared by copolymerization of 10 - 90 wt.%, preferably 40 - 80 wt.~, of a monomer of the general formula I
CH = C - COO - (CH2CH2O)n CH2 2 (I) where n is 1 or 2, with 90 - 10 wt.~ of 2-hydroxyethyl methacrylate and with 0.01 to 2 wt.% of at least one crosslinking agent having at least two olefinic double bonds, such as, for example, multifunctional esters or amides of acrylic or methacrylic acid, in the presence of at least one radical initiator.
The copolymerization is preferably carried out in the presence of a polar solvent, advantageously in the presence of glycerol, glycols and their derivatives, water, dimethyl-formamide, dimethylsulfoxide, dimethylacetamide, diacetine, isopropanol, or their mixture, with the weight ratio of the solvent to the monomer mixture ranging from 1 : 99 to 50 : 50.
The radical initiator can be selected from the group consisting of azo compounds, peroxides, peroxocarbonates, peroxosulfates, photoinitiators based on benzoin ethers and their derivatives, and initiation redox systems. Advantageously, use will be ~ade of peroxosulate - disulfite, peroxosulfate - alkylamines, and benzoyl peroxide - alkylamines, in a concentration 0.01 - 3 wt.%.
If the copolymerization is carried out in the absence of polar solvent or a mixture of polar solvents a bulk copolymer is obtained. Such a bulk copolymer is particularly useful for applications which require :~26~;~4~?2 mechanical working. But this copolymerization in bulk may be used also for the direct production of some articles.
In the presence of one or more polar solvents, the resulting copolymer contains a suitably chosen amount of solvent and is suitable for casting, e.g. for the centrifugal casting of contact lenses. The sol~ent, which would interfere in the mechanical working mentioned hereinabove, here positively affects the swelling pressures occuring during swelling of the final product.
Copolymers of 2-hydroxyethyl methacrylate with diethylene glycol monomethacrylate and of 2-hydroxyethyl methacrylate with triethylene glycol monomethacrylate are particularly preferred. These copolymers can be prepared in the presence of diethylene glycol dimethacrylate or trimethylene glycol dimethacrylate and ethylene glycol dimethacrylate, or in the presence of only one crosslinking component, which may be an arbitrary diester of methacrylic or acrylic acid with the corresponding alkyl glycol if the starting monomers are completely free of their corresponding diesters originating from their synthesis. Alternatively, the copolymerization can be carried out in the presence of methylene-bis-acrylamide, ethylene-bis-methacrylamide, hexamethylene-bis-methacrylamide, and the like, as crosslinking agents, or in the presence of their combinations, always in such a way that at least three components are entering the polymerization, two of which are monomers and the third one is a crosslinking agent, whereas one of two monoesters is always 2-hydroxyethyl methacrylate and the other monoester is either diethylene glycol monomethacrylate or triethylene glycol monomethacrylate. If
2-hydroxyethyl methacrylate is prepared from oxirane and methacrylic acid, it may contain up to 0.190 wt.~ of methacrylic acid, which amount is sufficient for the further processing to contact lenses.
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~a26~;J4~
The resulting hydrophilic terpolymer or tetra-polymer have such high mechanical properties that it can be used for the preparation of contact lenses or for medical purposes only at the above given ratio of said monoesters, provided that the admissible concentration of diesters or triesters of acrylic or methacrylic acid or of diamides of acrylic or methacrylic acid is maintained. At an increas-ing ratio of diethylene glycol monomethacrylate (DEGMA) or triethylene glycol monomethacrylate (TEGMA) to 2-hydroxy-ethyl methacrylate (H~MA) and a constant content ofdiesters or their mixture, the content of water in the final threedimensional hydrogel continuously increases and, for this ratio of components according to the invention, hydro-gels with suitable mechanical properties and an equilibrium water content 55 - 76% are obtained.
It is also possible and suitable for the produc-tion of high-swelling contact lenses, to extract with water the solvent or any water-soluble low-molecular-weight por-tion present in the crosslinked copolymer prepared in the presence of the above mentioned polar solvent, and then to dry it to a constant weight. The formed xerogel is excel-lent for mechanical working. The drying is advantageously carried out in saturated steam at a temperature above the glass-transition temperature Tg of the prepared copolymer.
The advantage of this procedure, in comparison with the method of preparation o~ contact lenses from various types o~ xerogels used until now, is not only that it makes it possible the perfect washing-ofE of low-molecular-weight comoponents as was mentioned above, but also that more ordered structure is obtained, with respect to the inner stress of cross links during polymerization.
This ordered structure is maintained during drying and the network resulting after the repeated swelling of a contact lens made from the xerogel prepared in this way is without ~ii';J4~Z
internal stress as a consequence of the ordered structure of cross links, which is visualized in a polarized light. This method of preparation also provides a high conversion of polymerizing components, as compared to the preparation of 5 xerogel materials by polymerization without solvent.
Another advantage of this method is that it in-creases the glass-transition temperature Tg six degrees centrigrade per each percent part of washed-out monomeric and low-molecular-weight portion, which favourably affects 10 the turning and polishing to the final shape of the contact lens.
The advantage oE drying water-swollen precast elements for turned contact lenses in saturated steam is that such a drying removes the polymerization solvent, i.e.
15 water, from the three-dimensional structure under the con- Z
dition of perfect mobility of polymer chains and their side segments (i.e. above the Tg of copolymer~, thus achieving rapid withdrawal of solvent without damage to the tree-dimensional structure while retaining the ratio of outer 20 dimensions and angles of the dried precast element with respect to the swollen one at the given initial composition of polymerization mixture.
The copolymers according to the invention have surprisingly higher values of strength than the homopoly-25 mers prepared from the above mentioned monomers DEGMA and TEGMA, at a low elasticity modulus. In contrast to all known higher-hydrophilic polymers used for the manufacturing of contact lenses, especially from vinylpyrrolidone, the co-polymers according to the invention are practically without 30 water soluble extracts. The copolymers according to the invention do not contain in their structure hydrophilic zones nor ionogenic groups and therefore substantially lower deposits of eye proteins may be expected in comparison to the known copolymers. The copolymers according to the . .
~2~ 4~2 invention also achieve a sufficiently high equilibrium content of water in the final product, so that they may be used for the production of contact lenses for permanent (long-term) wearing.
The invention is further illustrated in the following, non-limitative examples.
Example 1 A mixture of 70 wt.% of 2-hydroxyethyl metha-crylate (further HEMA) with 30 wt.~ of diethylene glycol monomethacrylate (further DEGMA) containing 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% dicthylene glycol dimethacrylate as a crosslinking agent, was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes by action of UV radiation. The resulting material contained after swelling 49.6 wt.% of water, had a modulus of elas-ticity in shear G = 1.03 kg.cm 2 and c~efficients of linear expansion Kv = 1.09 for swelling i H2O and Kf = 1.08 for swelling in physiologic saline. The coefficient of linear expansion is defined as a ratio of the diametter of a test piece in the swollen state to its dlameter after polymeri-zation.
Example 2 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-30 taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.~ of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total mass of monomers for 15 minutes by action of UV
. .
~ .
~6~
radiation. The resulting material contained, after swelling, 53.6 wt.% of water and had a modulus of elasticity in shear G = 0.85 kg.cm 2 and coefficients of linear expan-sion Kv = 1.12 and Kf = 1.12.
Example 3 A mixture of 50 wt. HEMA and 50 wt.~ DEGMA con-taining 0.45 wt.~ of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV radia-tion. The resulting material contained, after swelling, 59.5 wt.% of water, had an elongation of 120%, a strength 1.50 kg.cm , G = 0.73 kg.cm 2, Kv = 1.15, and Kf = 1.15.
Example 4 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 63.1 wt.% of water and had G = 0.63 kg.cm , Kv = 1.21 and Kf = 1.20.
_xample 5 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate, was mixed in ':
.
. . .
.
: . , .
~i74~2 the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 25 minutes under UV radiation. The resulting material contained after swel-ling 68 wt.% of water at G = 0.57 kg.cm 2, Kv = 1.2~ and Kf = 1.23.
Example 6 A mixture of 70 wt.% HEMA and 30 wt.% DEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimethacrylate and 0.3 wt.~ of triethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV radia-tion. The resulting material contained, after swelling, 50.1 wt.% of water at G = 1.19 kg.cm ~ Kv = 1.14 and Kf = 1.14.
Example 7 A mixture of 60 wt.% HEMA and 40 wt.~ DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.~ with 30 wt.~ of glycexol. This mixture was polymerized with 0.5 wt~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 54.2 wt.% of water at G = 0.97 kg.cm 2, Kv = 1.17 and Kf = 1.17.
Example 8 ,~ .
A mixture o~ 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.~ of diethylene glycol dimethacrylate and :~;Z6~ 2 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with O.S wt.% of benzoin ethyl ether for 15 minutes under UV xadiation. The resulting material contained, after swelling, 63.1 wt.% of water at G = 0.75 kg.cm , Kv = 1.25 and Kf = 1.25.
Example 9 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes under UV radiation. The resulting material contained, after swelling, 67.4 wt.% of water at G = 0.67 kg.cm2, Kv = 1.29, Kf = 1.28.
Example 10 A mixture of 70 wt.% HEMA and 30 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.96 with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes under UV radiation. The resulting material contain-ed, after swelling, 49.6 wt.% of water at G = 1.39 kg.cm 2;
elongation 110%, strength 2.2 kg.cm ~ Kv ~ 1.18 and Kf =
1.17.
Example 11 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 _ g _ , .
~2~i~7~
wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 53.6 wt.% of water at G = 1.22 kg.cm ; Kv = 1.22, Kf = 1.21.
Example 12 A mixture of 50 wt.~ HEMA and 50 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.~ with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 58.9 wt,% of water at G = 1.08 kg.cm ; Kv =
1.23, Kf = 1.21.
Example 13 A mixture of 40 wt.~ ~EMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.~ of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.~ with 20 wt.~ of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-30 ling, 60.1 wt.~ of water at G = 0.94 kg.cm ; Kv = 1-27, Kf = 1.26.
':
.
:
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Example _ A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total arnount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 63.7 wt.% of water at G = 0.82 kg.cm ; Kv = 1.31, Kf = 1.30.
Example 15 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling,50.7 wt.% of water at G = 1.43 kg.cm ; Kv = 1.23, Kf =
1.21.
Example 16 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 53.6 wt.% of water at G = 1.21 kg.cm ; strength 1.80 kg.cm , elongation 80%; Kv = 1.26 and Kf = 1.24.
~ .
Example 17 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 5 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wr.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-10ling, 58.3 wt.% of water at G = 1.08 kg.cm ; KV = 1.31 and Kf = 1.28.
Example 18 15A mixture of 30 wt.~ HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 63.1 wt.% of water at G = 0.94 kg.cm 2; Kv = 1.37 and Kf = 1.33.
Example 19 A mixture oE 60 wt.~ ~EMA and 40 wt.% DEGMA con-taining 0.~ wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 50 wt.% of water at G = 0.85 kg.cm 2, strength 2.15 . ' .
' -- ', ~ ' .
.
' ~6~;J4~2 kg.cm 2, strength 2.15 kg.cm 2, elongation 220%, Kv = Kf =
1.10.
Example 20 A mixture of 60 wt.% HEMA and 40 wt.% DE&MA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of ~enzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contains, after swelling, 54 wt.% of water at G = 0.75 kg.cm 2, strength 2.10 kg.cm 2 and elongation 230%; Kv = Kf = 1.14.
Example 21 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.6 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 49 wt.% of water at G = 1.1 kg.cm , elongation 150% and stren~th 2.40 kg.cm 2.
Example 22 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol.
This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes ' : ' ' :~ .
, ' ~ ' :~;26, g~92 under W radiation. The resulting material contained, after swelling, 55 wt.% of water at G - 1.10 kg.cm 2, strength 2.60 kg.cm 2 and elongation 160%.
Example 23 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of cliethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. The mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contains, after swelling, 62 wt.~ of water at G = 0.70 kg.cm 2, strength 1.6 kg.cm 2 and elongation 135%.
Exanple 24 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and0.15 wt.% ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. This mixture was pol~merized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomerr for 15 minutes by UV
radiation. The resulting material contained, after swelling, 62 wt.% of water at G = 0.74 kg.cm ~, strength 1.85 kg.cm and elongation 150%.
Example 25 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. This mixture .
.. . . .
, ~26~74~2 was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV
radiation. The resulting material contained, after swel-ling, 64 wt.~ of water at G = 0.82 kg.cm 2, strength 2.60 kg.cm and elongation 205%.
Example 26 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 55 wt.% of water at G = 0.70 kg.cm 2, Example 27 A mixture of 60 wt.~ HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.1 wt.~ of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54 wt.% of water at G = 1.01 kg.cm 2, Example 28 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol.
This mixture was polymerized with 0.1 wt.% of diisopropyl : `
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peroxocarbonate related to the total amount of monomers at 60C for 16 hours. The resulting material contained, after swelling, 58.9 wt.% of water at G = 0.62 kg.cm 2.
Example 29 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol.
This mixture was polymerized with 0.1 wt.% diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 58.9 wt.% of water at G = 1.05 kg.cm Example 30 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers at 60C for 16 hours. The resulting material contained, after swelling, 65.7 wt.% of water at G = 0.50 kg.cm 2.
Example 31 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glyceral. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after ' ' ~6~;'4L~2 swelling, 64.3 wt.% of water at G = 0.75 kg.cm 2.
Example 32 A mixture of 60 wt.~ HEMA and 40 wt.~ DEGMA con-taining 0.15 wt.~ of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol.
This mixture was polymerized with 0.20 wt.% of a~obisiso-butyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54.7 wt.% of water at G = 0.75 kg.cm Example 33 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and O.lS
wt.% diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.~ of glycerol. This mixture was polymerized with 0.2 wt.% ammonium peroxosulfate for hour at 78C. The resulting material contained, after swel-ling, 54.9 wt.~ of water at G = 0.75 kg.cm 2.
Example 34 A mixture of 60 wt.~ HEMA and 40 wt.% DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.~ of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for lS minutes by W irradiation. The resulting material contained, after swelling, 55 wt.% of water at G = 0.70 kg.cm 2.
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Example 35 A mixture of 20 wt.% HEMA and 80 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and S 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.~ glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by Uv radiation. The resulting material contained, after swelling, 70 wt~% of water at G = 0.38 kg.cm , elongation 160% and strength 1.03 kg.cm 2.
Example 36 A mixture of 10 wt.% HEMA and 90 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.~ with 15 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% benzoin ethyl ether for 15 minutes by W radiation. The resulting material contained, after swelling, 74 wt.% of water at G = 0.4 kg.cm 2, elonga-tion 160% and strength 1.00 k~.cm 2.
Example 37 A mixture of 60 wt.~ of 2-hydroxyethyl methacrylate (further HEMA) and 40 wt.~ of diethylene glycol monomethacrylate (further DEGMA) containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 52.2 wt.~ of water at an elasticity modulus in shear G = 3.25 kg.cm 2 and was suitable for turned contact lenses.
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Example 38 A mixture oE 50 wt.~ HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% ethylene glycol dimethacrylate was poly-merized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total a~ount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 52.2% of water at G = 2.90 kg.cm 2 and was suitable for turned contact lenses.
Example 39 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.20 wt.~ of ethylene glycol dimethacrylate and 0.15 wt.% diethylene glycol dimethacrylate was polymerized with 0.1 wt.~ of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 kg.cm 2.
Example 40 A mixture of 30 wt.~ HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and0.15 wt.% ethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 60 wt.% of water at G = 2.32 kg.cm 2.
Example 41 A mixture o 20 wt.% HEMA and 80 wt.% DEGMA con-. ~ .
-~;~6~
taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 63.7 wt.% of water at G = 1.~3 kg.cm Example 42 A mixture of 10 wt.% HEMA and 90 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 15 66.6 wt.% of water at G = 1.13 kg.cm 2.
Example 43 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate waspolymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54.7 wt.~ of water at G = 2.90 kg.cm 2.
Example 44 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA con-taining 0.6 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 53 wt.% of water at G = 3.05 kg.cm , .. .
- '. ' ` ' ~ :
~ J4 Example 45 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con~
taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 cm 2, Example 46 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimethacrylate and 0.3 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% ofammonium peroxosulfate related to the total amount of monomers for 1 hour at 78C. The resulting material contained, after swelling, 56 wt.% of water at G = 2.72 kg.cm Example 47 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-25 taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by UV
radiation. The resulting material conttained, after swelling, 56.3 wt.% of water at G = 2.i2 kg.cm 2.
Example 48 A mixture of 40 wt.% ~EMA and 60 wt.% DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and , ~
, ~ 216 ~
O.lS wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by UV radiation. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 kg.cm 2.
Example 49 A mixture of 90 wt.% of 2-hydroxyethyl methacrylate (HEMA) and 10 wt.% of triethylene glycol 10 methacrylate (further TEGMA) containiny 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.~ of triethylene glycol dimethacrylate as a crosslinking agent was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by W radiation. The resulting 15 material contains, after swelling, 48 wt.% of water.
Example 50 A mixture of 80 wt.% HEMA and 20 wt.% TEGMA con-20 taining 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.% triethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomer5 for 15 minutes by W radiation.
25 The resulting material contained, after swelling, 53 wt.% of water at an elasticity modulus in shear G = 1.33 kg.cm 2, Example 51 A mixture of 50 wt.% HEMA and 50 wt.~ TEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% triethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related : . .
- : .
~llZ6';)~2 to the total amount of monomers for lS minutes by UV
radiation. The resulting material contained, after swelling, 67 wt.% of water at an elasticity modulus in shear G = 0.50 kg.cm Example 52 A mixture of 15 wt.% HEMA and 85 wt.~ TEGMA con-taining 0.3 wt.% of ethylene ~lycol dimethacrylate and 0.6 wt.% of triethylene glycol methacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 77 wt.~ of water.
Example 53 A mixture of 40 wt.% HEMA and 60 wt.% TEGMA con-taining 0.3 wt.~ of ethylene glycol dimethacrylate and 0.6wt.% of triethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with O.S wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV
radiation. The resulting material contained 76 wt.% of water after swelling at G = 0.45 kg.cm 2.
Example 54 A mixture of 50 wt.% HEMA and 50 wt.% TEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.~ with 40 wt.% of glycerol.
This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes . .
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under UV radiation. The resulting material contained, after swelling, 69 wt.~ of water.
Example 55 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA containing 0.3 wt.% of ethylene-bis-acrylamide and 0.2 wt.% diethylene glycol dimethacrylate was mixed in the amount 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV radiation. The resulting material contained, after swelling, 67.5 wt.% of water at G
= 0.56 kg.cm ~ Kv = 1.24 and Kf = 1.225.
Example 56 A mixture of 60 wt.% DEGMA and 40 wt.% HEMA con-taining 0.4 wt.% of hexamethylene-bis-acrylamide and 0.35 wt.% of methylene-bis-acrylamide was mixed in the amount of wt.% with 25 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the whole mixture at 60C ~or 15 minutes. The resulting material contained, after swelling, 63 wt.% of water at G = 0.75 kg.cm 2, Kv = 1.25 and Kf = 1.25.
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The resulting hydrophilic terpolymer or tetra-polymer have such high mechanical properties that it can be used for the preparation of contact lenses or for medical purposes only at the above given ratio of said monoesters, provided that the admissible concentration of diesters or triesters of acrylic or methacrylic acid or of diamides of acrylic or methacrylic acid is maintained. At an increas-ing ratio of diethylene glycol monomethacrylate (DEGMA) or triethylene glycol monomethacrylate (TEGMA) to 2-hydroxy-ethyl methacrylate (H~MA) and a constant content ofdiesters or their mixture, the content of water in the final threedimensional hydrogel continuously increases and, for this ratio of components according to the invention, hydro-gels with suitable mechanical properties and an equilibrium water content 55 - 76% are obtained.
It is also possible and suitable for the produc-tion of high-swelling contact lenses, to extract with water the solvent or any water-soluble low-molecular-weight por-tion present in the crosslinked copolymer prepared in the presence of the above mentioned polar solvent, and then to dry it to a constant weight. The formed xerogel is excel-lent for mechanical working. The drying is advantageously carried out in saturated steam at a temperature above the glass-transition temperature Tg of the prepared copolymer.
The advantage of this procedure, in comparison with the method of preparation o~ contact lenses from various types o~ xerogels used until now, is not only that it makes it possible the perfect washing-ofE of low-molecular-weight comoponents as was mentioned above, but also that more ordered structure is obtained, with respect to the inner stress of cross links during polymerization.
This ordered structure is maintained during drying and the network resulting after the repeated swelling of a contact lens made from the xerogel prepared in this way is without ~ii';J4~Z
internal stress as a consequence of the ordered structure of cross links, which is visualized in a polarized light. This method of preparation also provides a high conversion of polymerizing components, as compared to the preparation of 5 xerogel materials by polymerization without solvent.
Another advantage of this method is that it in-creases the glass-transition temperature Tg six degrees centrigrade per each percent part of washed-out monomeric and low-molecular-weight portion, which favourably affects 10 the turning and polishing to the final shape of the contact lens.
The advantage oE drying water-swollen precast elements for turned contact lenses in saturated steam is that such a drying removes the polymerization solvent, i.e.
15 water, from the three-dimensional structure under the con- Z
dition of perfect mobility of polymer chains and their side segments (i.e. above the Tg of copolymer~, thus achieving rapid withdrawal of solvent without damage to the tree-dimensional structure while retaining the ratio of outer 20 dimensions and angles of the dried precast element with respect to the swollen one at the given initial composition of polymerization mixture.
The copolymers according to the invention have surprisingly higher values of strength than the homopoly-25 mers prepared from the above mentioned monomers DEGMA and TEGMA, at a low elasticity modulus. In contrast to all known higher-hydrophilic polymers used for the manufacturing of contact lenses, especially from vinylpyrrolidone, the co-polymers according to the invention are practically without 30 water soluble extracts. The copolymers according to the invention do not contain in their structure hydrophilic zones nor ionogenic groups and therefore substantially lower deposits of eye proteins may be expected in comparison to the known copolymers. The copolymers according to the . .
~2~ 4~2 invention also achieve a sufficiently high equilibrium content of water in the final product, so that they may be used for the production of contact lenses for permanent (long-term) wearing.
The invention is further illustrated in the following, non-limitative examples.
Example 1 A mixture of 70 wt.% of 2-hydroxyethyl metha-crylate (further HEMA) with 30 wt.~ of diethylene glycol monomethacrylate (further DEGMA) containing 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% dicthylene glycol dimethacrylate as a crosslinking agent, was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes by action of UV radiation. The resulting material contained after swelling 49.6 wt.% of water, had a modulus of elas-ticity in shear G = 1.03 kg.cm 2 and c~efficients of linear expansion Kv = 1.09 for swelling i H2O and Kf = 1.08 for swelling in physiologic saline. The coefficient of linear expansion is defined as a ratio of the diametter of a test piece in the swollen state to its dlameter after polymeri-zation.
Example 2 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-30 taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.~ of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total mass of monomers for 15 minutes by action of UV
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radiation. The resulting material contained, after swelling, 53.6 wt.% of water and had a modulus of elasticity in shear G = 0.85 kg.cm 2 and coefficients of linear expan-sion Kv = 1.12 and Kf = 1.12.
Example 3 A mixture of 50 wt. HEMA and 50 wt.~ DEGMA con-taining 0.45 wt.~ of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV radia-tion. The resulting material contained, after swelling, 59.5 wt.% of water, had an elongation of 120%, a strength 1.50 kg.cm , G = 0.73 kg.cm 2, Kv = 1.15, and Kf = 1.15.
Example 4 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.2 wt.% of diethylene glycol dimethacrylate and 0.7 wt.% of triethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 63.1 wt.% of water and had G = 0.63 kg.cm , Kv = 1.21 and Kf = 1.20.
_xample 5 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate, was mixed in ':
.
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~i74~2 the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total mass of monomers for 25 minutes under UV radiation. The resulting material contained after swel-ling 68 wt.% of water at G = 0.57 kg.cm 2, Kv = 1.2~ and Kf = 1.23.
Example 6 A mixture of 70 wt.% HEMA and 30 wt.% DEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimethacrylate and 0.3 wt.~ of triethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total mass of monomers for 15 minutes under UV radia-tion. The resulting material contained, after swelling, 50.1 wt.% of water at G = 1.19 kg.cm ~ Kv = 1.14 and Kf = 1.14.
Example 7 A mixture of 60 wt.% HEMA and 40 wt.~ DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.~ with 30 wt.~ of glycexol. This mixture was polymerized with 0.5 wt~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 54.2 wt.% of water at G = 0.97 kg.cm 2, Kv = 1.17 and Kf = 1.17.
Example 8 ,~ .
A mixture o~ 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.~ of diethylene glycol dimethacrylate and :~;Z6~ 2 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with O.S wt.% of benzoin ethyl ether for 15 minutes under UV xadiation. The resulting material contained, after swelling, 63.1 wt.% of water at G = 0.75 kg.cm , Kv = 1.25 and Kf = 1.25.
Example 9 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes under UV radiation. The resulting material contained, after swelling, 67.4 wt.% of water at G = 0.67 kg.cm2, Kv = 1.29, Kf = 1.28.
Example 10 A mixture of 70 wt.% HEMA and 30 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.96 with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes under UV radiation. The resulting material contain-ed, after swelling, 49.6 wt.% of water at G = 1.39 kg.cm 2;
elongation 110%, strength 2.2 kg.cm ~ Kv ~ 1.18 and Kf =
1.17.
Example 11 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 _ g _ , .
~2~i~7~
wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 53.6 wt.% of water at G = 1.22 kg.cm ; Kv = 1.22, Kf = 1.21.
Example 12 A mixture of 50 wt.~ HEMA and 50 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.~ with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 58.9 wt,% of water at G = 1.08 kg.cm ; Kv =
1.23, Kf = 1.21.
Example 13 A mixture of 40 wt.~ ~EMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.~ of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.~ with 20 wt.~ of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-30 ling, 60.1 wt.~ of water at G = 0.94 kg.cm ; Kv = 1-27, Kf = 1.26.
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Example _ A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total arnount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 63.7 wt.% of water at G = 0.82 kg.cm ; Kv = 1.31, Kf = 1.30.
Example 15 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.45 wt.% of ethylene glycol dimethacrylate and 0.2 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling,50.7 wt.% of water at G = 1.43 kg.cm ; Kv = 1.23, Kf =
1.21.
Example 16 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV radiation. The resulting material contained, after swel-ling, 53.6 wt.% of water at G = 1.21 kg.cm ; strength 1.80 kg.cm , elongation 80%; Kv = 1.26 and Kf = 1.24.
~ .
Example 17 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 5 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wr.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-10ling, 58.3 wt.% of water at G = 1.08 kg.cm ; KV = 1.31 and Kf = 1.28.
Example 18 15A mixture of 30 wt.~ HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 90 wt.% with 10 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 63.1 wt.% of water at G = 0.94 kg.cm 2; Kv = 1.37 and Kf = 1.33.
Example 19 A mixture oE 60 wt.~ ~EMA and 40 wt.% DEGMA con-taining 0.~ wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swel-ling, 50 wt.% of water at G = 0.85 kg.cm 2, strength 2.15 . ' .
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.
' ~6~;J4~2 kg.cm 2, strength 2.15 kg.cm 2, elongation 220%, Kv = Kf =
1.10.
Example 20 A mixture of 60 wt.% HEMA and 40 wt.% DE&MA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of ~enzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contains, after swelling, 54 wt.% of water at G = 0.75 kg.cm 2, strength 2.10 kg.cm 2 and elongation 230%; Kv = Kf = 1.14.
Example 21 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.6 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 49 wt.% of water at G = 1.1 kg.cm , elongation 150% and stren~th 2.40 kg.cm 2.
Example 22 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol.
This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes ' : ' ' :~ .
, ' ~ ' :~;26, g~92 under W radiation. The resulting material contained, after swelling, 55 wt.% of water at G - 1.10 kg.cm 2, strength 2.60 kg.cm 2 and elongation 160%.
Example 23 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of cliethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. The mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contains, after swelling, 62 wt.~ of water at G = 0.70 kg.cm 2, strength 1.6 kg.cm 2 and elongation 135%.
Exanple 24 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and0.15 wt.% ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. This mixture was pol~merized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomerr for 15 minutes by UV
radiation. The resulting material contained, after swelling, 62 wt.% of water at G = 0.74 kg.cm ~, strength 1.85 kg.cm and elongation 150%.
Example 25 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.% with 15 wt.% of glycerol. This mixture .
.. . . .
, ~26~74~2 was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV
radiation. The resulting material contained, after swel-ling, 64 wt.~ of water at G = 0.82 kg.cm 2, strength 2.60 kg.cm and elongation 205%.
Example 26 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 55 wt.% of water at G = 0.70 kg.cm 2, Example 27 A mixture of 60 wt.~ HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.1 wt.~ of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54 wt.% of water at G = 1.01 kg.cm 2, Example 28 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol.
This mixture was polymerized with 0.1 wt.% of diisopropyl : `
.
-:
. .
, ::lL2~
peroxocarbonate related to the total amount of monomers at 60C for 16 hours. The resulting material contained, after swelling, 58.9 wt.% of water at G = 0.62 kg.cm 2.
Example 29 A mixture of 50 wt.% HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol.
This mixture was polymerized with 0.1 wt.% diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 58.9 wt.% of water at G = 1.05 kg.cm Example 30 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers at 60C for 16 hours. The resulting material contained, after swelling, 65.7 wt.% of water at G = 0.50 kg.cm 2.
Example 31 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glyceral. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after ' ' ~6~;'4L~2 swelling, 64.3 wt.% of water at G = 0.75 kg.cm 2.
Example 32 A mixture of 60 wt.~ HEMA and 40 wt.~ DEGMA con-taining 0.15 wt.~ of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.% of glycerol.
This mixture was polymerized with 0.20 wt.% of a~obisiso-butyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54.7 wt.% of water at G = 0.75 kg.cm Example 33 A mixture of 60 wt.% HEMA and 40 wt.% DEGMA con-taining 0.20 wt.% of ethylene glycol dimethacrylate and O.lS
wt.% diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.~ of glycerol. This mixture was polymerized with 0.2 wt.% ammonium peroxosulfate for hour at 78C. The resulting material contained, after swel-ling, 54.9 wt.~ of water at G = 0.75 kg.cm 2.
Example 34 A mixture of 60 wt.~ HEMA and 40 wt.% DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was mixed in the amount of 60 wt.% with 40 wt.~ of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for lS minutes by W irradiation. The resulting material contained, after swelling, 55 wt.% of water at G = 0.70 kg.cm 2.
,: , , ' . :
~6~;J4~Z
Example 35 A mixture of 20 wt.% HEMA and 80 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and S 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.~ glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by Uv radiation. The resulting material contained, after swelling, 70 wt~% of water at G = 0.38 kg.cm , elongation 160% and strength 1.03 kg.cm 2.
Example 36 A mixture of 10 wt.% HEMA and 90 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and 0.15 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 85 wt.~ with 15 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% benzoin ethyl ether for 15 minutes by W radiation. The resulting material contained, after swelling, 74 wt.% of water at G = 0.4 kg.cm 2, elonga-tion 160% and strength 1.00 k~.cm 2.
Example 37 A mixture of 60 wt.~ of 2-hydroxyethyl methacrylate (further HEMA) and 40 wt.~ of diethylene glycol monomethacrylate (further DEGMA) containing 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.~ of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 52.2 wt.~ of water at an elasticity modulus in shear G = 3.25 kg.cm 2 and was suitable for turned contact lenses.
. . . . .
~ . .
: ' ,: ' ' ' ' , ',', . ~ ~ ' . ' ':
-'~
~2~74~;~
Example 38 A mixture oE 50 wt.~ HEMA and 50 wt.% DEGMA con-taining 0.15 wt.% ethylene glycol dimethacrylate was poly-merized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total a~ount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 52.2% of water at G = 2.90 kg.cm 2 and was suitable for turned contact lenses.
Example 39 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.20 wt.~ of ethylene glycol dimethacrylate and 0.15 wt.% diethylene glycol dimethacrylate was polymerized with 0.1 wt.~ of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 kg.cm 2.
Example 40 A mixture of 30 wt.~ HEMA and 70 wt.% DEGMA con-taining 0.6 wt.% of diethylene glycol dimethacrylate and0.15 wt.% ethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 60 wt.% of water at G = 2.32 kg.cm 2.
Example 41 A mixture o 20 wt.% HEMA and 80 wt.% DEGMA con-. ~ .
-~;~6~
taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 63.7 wt.% of water at G = 1.~3 kg.cm Example 42 A mixture of 10 wt.% HEMA and 90 wt.% DEGMA con-taining 0.15 wt.% of ethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 15 66.6 wt.% of water at G = 1.13 kg.cm 2.
Example 43 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate waspolymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 54.7 wt.~ of water at G = 2.90 kg.cm 2.
Example 44 A mixture of 40 wt.% HEMA and 60 wt.~ DEGMA con-taining 0.6 wt.% of ethylene glycol dimethacrylate was polymerized with 0.2 wt.% of azobisisobutyronitrile related to the total amount of monomers for 16 hours at 60C. The resulting material contained, after swelling, 53 wt.% of water at G = 3.05 kg.cm , .. .
- '. ' ` ' ~ :
~ J4 Example 45 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con~
taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the total amount of monomers for 16 hours at 60 C. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 cm 2, Example 46 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate, 0.20 wt.% of diethylene glycol dimethacrylate and 0.3 wt.% of triethylene glycol dimethacrylate was polymerized with 0.2 wt.% ofammonium peroxosulfate related to the total amount of monomers for 1 hour at 78C. The resulting material contained, after swelling, 56 wt.% of water at G = 2.72 kg.cm Example 47 A mixture of 40 wt.% HEMA and 60 wt.% DEGMA con-25 taining 0.20 wt.% of ethylene glycol dimethacrylate and 0.15 wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by UV
radiation. The resulting material conttained, after swelling, 56.3 wt.% of water at G = 2.i2 kg.cm 2.
Example 48 A mixture of 40 wt.% ~EMA and 60 wt.% DEGMA
containing 0.20 wt.% of ethylene glycol dimethacrylate and , ~
, ~ 216 ~
O.lS wt.% of diethylene glycol dimethacrylate was polymerized with 0.5 wt.% of benzoin ethyl ether for 15 minutes by UV radiation. The resulting material contained, after swelling, 56.2 wt.% of water at G = 2.70 kg.cm 2.
Example 49 A mixture of 90 wt.% of 2-hydroxyethyl methacrylate (HEMA) and 10 wt.% of triethylene glycol 10 methacrylate (further TEGMA) containiny 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.~ of triethylene glycol dimethacrylate as a crosslinking agent was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by W radiation. The resulting 15 material contains, after swelling, 48 wt.% of water.
Example 50 A mixture of 80 wt.% HEMA and 20 wt.% TEGMA con-20 taining 0.4 wt.% of ethylene glycol dimethacrylate and 0.20 wt.% triethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomer5 for 15 minutes by W radiation.
25 The resulting material contained, after swelling, 53 wt.% of water at an elasticity modulus in shear G = 1.33 kg.cm 2, Example 51 A mixture of 50 wt.% HEMA and 50 wt.~ TEGMA con-taining 0.3 wt.% of ethylene glycol dimethacrylate and 0.6 wt.% triethylene glycol dimethacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related : . .
- : .
~llZ6';)~2 to the total amount of monomers for lS minutes by UV
radiation. The resulting material contained, after swelling, 67 wt.% of water at an elasticity modulus in shear G = 0.50 kg.cm Example 52 A mixture of 15 wt.% HEMA and 85 wt.~ TEGMA con-taining 0.3 wt.% of ethylene ~lycol dimethacrylate and 0.6 wt.% of triethylene glycol methacrylate was mixed in the amount of 80 wt.% with 20 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes under UV
radiation. The resulting material contained, after swelling, 77 wt.~ of water.
Example 53 A mixture of 40 wt.% HEMA and 60 wt.% TEGMA con-taining 0.3 wt.~ of ethylene glycol dimethacrylate and 0.6wt.% of triethylene glycol dimethacrylate was mixed in the amount of 70 wt.% with 30 wt.% of glycerol. This mixture was polymerized with O.S wt.% of benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV
radiation. The resulting material contained 76 wt.% of water after swelling at G = 0.45 kg.cm 2.
Example 54 A mixture of 50 wt.% HEMA and 50 wt.% TEGMA con-taining 0.5 wt.% of ethylene glycol dimethacrylate was mixed in the amount of 60 wt.~ with 40 wt.% of glycerol.
This mixture was polymerized with 0.5 wt.~ of benzoin ethyl ether related to the total amount of monomers for 15 minutes . .
,' , ~ ~ : ':
lZ~
under UV radiation. The resulting material contained, after swelling, 69 wt.~ of water.
Example 55 A mixture of 30 wt.% HEMA and 70 wt.% DEGMA containing 0.3 wt.% of ethylene-bis-acrylamide and 0.2 wt.% diethylene glycol dimethacrylate was mixed in the amount 60 wt.% with 40 wt.% of glycerol. This mixture was polymerized with 0.5 wt.% benzoin ethyl ether related to the total amount of monomers for 15 minutes by UV radiation. The resulting material contained, after swelling, 67.5 wt.% of water at G
= 0.56 kg.cm ~ Kv = 1.24 and Kf = 1.225.
Example 56 A mixture of 60 wt.% DEGMA and 40 wt.% HEMA con-taining 0.4 wt.% of hexamethylene-bis-acrylamide and 0.35 wt.% of methylene-bis-acrylamide was mixed in the amount of wt.% with 25 wt.% of glycerol. This mixture was polymerized with 0.1 wt.% of diisopropyl peroxocarbonate related to the whole mixture at 60C ~or 15 minutes. The resulting material contained, after swelling, 63 wt.% of water at G = 0.75 kg.cm 2, Kv = 1.25 and Kf = 1.25.
', :
Claims (11)
1. A hydrophilic copolymer particularly suitable for contact lenses and other medical applications, said copolymer being prepared by copolymerization of 10 - 90 wt.%, of a monomer of the general formula I
(I) where n is 1 or 2, with 90 - 10 wt.% of 2-hydroxyethyl methacrylate and 0.01 to 2 wt.% of at least one crosslinking agent having at least two olefinic double bonds, in the presence of at least one radical initiator.
(I) where n is 1 or 2, with 90 - 10 wt.% of 2-hydroxyethyl methacrylate and 0.01 to 2 wt.% of at least one crosslinking agent having at least two olefinic double bonds, in the presence of at least one radical initiator.
2. A hydrophilic copolymer according to claim 1, comprising 40 - 80 wt.% of the monomer of formula I.
3. The hydrophilic copolymer according to claim 1, wherein the copolymerization is carried out in the presence of at least one polar solvent, and wherein the weight ratio of solvent to the monomer mixture is ranging from 1:99 to 50:50.
4. The hydrophilic copolymer according to claim 1, 2 or 3, wherein the copolymerization is carried out in the presence of glycerol, glycols and their derivatives, water, dimethylformamide, dimethylsulfoxide, dimethylacetamide, diacetine, isopropanol or their mixtures.
5. The hydrophilic copolymer according to claim 1, 2 or 3, wherein the crosslinking agent is selected from the group consisting of multifunctional esters and amides of acrylic and methacrylic acid.
6. The hydrophilic copolymer according to claim 1, 2 or 3, wherein the 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.
7. The hydrophilic copolymer according to claim 1, 2 or 3, wherein the radical initiator is selected from the group consisting of peroxosulfate - disulfite, peroxosulfate - alkylamines and benzoyl peroxide - alkylamines, in a con-centration of 0.01 - 3 wt.%.
8. A method for preparing a hydrophilic copolymer according to claim 1, wherein 90 to 10 wt.% of 2-hydroxyethyl methacrylate is copolymerized with 10 - 90 wt.%
of a monomer of the general formula I as defined in claim in the presence of 0.01 - 2 wt.% of at least one multifunctional ester or amide of acrylic or methacrylic acid, having at least two olefinic double bonds, in the presence of at least one radical initiator.
of a monomer of the general formula I as defined in claim in the presence of 0.01 - 2 wt.% of at least one multifunctional ester or amide of acrylic or methacrylic acid, having at least two olefinic double bonds, in the presence of at least one radical initiator.
9. The method according to claim 8, wherein the copolymerization is carried out in the presence of a polar solvent or a mixture of polar solvents, the weight ratio of the solvent to the monomer mixture being from 1:99 to 50:50.
10. The method according to claim 9, wherein the solvent and water-soluble low-molecular-weight portions, if any, present in the crosslinked copolymer are extracted with water and the copolymer is subsequently dried to a constant weight.
11. The method according to claim 10, wherein drying is performed in the presence of saturated steam at a temperature above the glass-transition temperature Tg of the prepared copolymer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CSPV5585-85 | 1985-07-31 | ||
| CS855585A CS252224B1 (en) | 1985-07-31 | 1985-07-31 | Hydrophilic copolymer suitable eapecially for contact lenses and medicinal utilization and method of its producion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1267492A true CA1267492A (en) | 1990-04-03 |
Family
ID=5401021
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000514998A Expired - Fee Related CA1267492A (en) | 1985-07-31 | 1986-07-30 | Hydrophilic copolymer suitable above all for contact lenses and medical purposes and a method of its preparation |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS6254709A (en) |
| CA (1) | CA1267492A (en) |
| CS (1) | CS252224B1 (en) |
| DE (1) | DE3625869C2 (en) |
| FR (1) | FR2585710B1 (en) |
| GB (1) | GB2178435B (en) |
| IT (1) | IT1213463B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CS256437B1 (en) * | 1985-09-04 | 1988-04-15 | Otto Wichterle | Hydrophilic copolymer especially for contact lenses and medicinal application and method of its production |
| CS257979B1 (en) * | 1986-06-24 | 1988-07-15 | Otto Wichterle | Hydrophilic copolymer and method of its production |
| US4871785A (en) * | 1986-08-13 | 1989-10-03 | Michael Froix | Clouding-resistant contact lens compositions |
| US5256751A (en) * | 1993-02-08 | 1993-10-26 | Vistakon, Inc. | Ophthalmic lens polymer incorporating acyclic monomer |
| WO1996003666A1 (en) * | 1994-07-26 | 1996-02-08 | Bausch & Lomb Incorporated | Method of polymerizing methacrylate-based compositions |
| AU2015201371A1 (en) * | 2014-03-31 | 2015-10-15 | Johnson & Johnson Vision Care, Inc. | Silicone acrylamide copolymer |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB814009A (en) * | 1956-04-24 | 1959-05-27 | Otto Wichterle | Three-dimensional hydrophilic high polymeric articles |
| US3220960A (en) * | 1960-12-21 | 1965-11-30 | Wichterle Otto | Cross-linked hydrophilic polymers and articles made therefrom |
| DE1495381B2 (en) * | 1963-09-07 | 1971-06-24 | Czeskoslovenska akademie ved , Prag | METHOD FOR MANUFACTURING CONTACT LENSES OR CONTACT LENS BLOCKS FROM SWELLABLE HYDROGELS |
| DE2020329C3 (en) * | 1969-05-13 | 1974-07-25 | Ceskoslovenska Akademie Ved, Prag | Process for the production of sparsely cross-linked, crystal-clear, swellable, non-dimensionally stable hydrogels |
| US3839304A (en) * | 1973-02-12 | 1974-10-01 | American Optical Corp | Soft contact lens and method of production thereof |
| DE2364856C3 (en) * | 1973-12-28 | 1980-10-02 | Teroson Gmbh, 6900 Heidelberg | Moisture-curing, solvent-free sealing compound based on organopolysiloxanes and silicone oil |
| US4038264A (en) * | 1974-01-07 | 1977-07-26 | National Patent Development Corporation | Hema copolymers having high oxygen permeability |
| JPS543738B2 (en) * | 1974-05-27 | 1979-02-26 |
-
1985
- 1985-07-31 CS CS855585A patent/CS252224B1/en not_active IP Right Cessation
-
1986
- 1986-07-16 GB GB8617318A patent/GB2178435B/en not_active Expired
- 1986-07-25 IT IT8621262A patent/IT1213463B/en active
- 1986-07-30 FR FR868611033A patent/FR2585710B1/en not_active Expired - Fee Related
- 1986-07-30 CA CA000514998A patent/CA1267492A/en not_active Expired - Fee Related
- 1986-07-31 DE DE3625869A patent/DE3625869C2/en not_active Expired - Fee Related
- 1986-07-31 JP JP61178976A patent/JPS6254709A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| GB8617318D0 (en) | 1986-08-20 |
| FR2585710A1 (en) | 1987-02-06 |
| IT1213463B (en) | 1989-12-20 |
| IT8621262A0 (en) | 1986-07-25 |
| JPS6254709A (en) | 1987-03-10 |
| CS558585A1 (en) | 1987-01-15 |
| CS252224B1 (en) | 1987-08-13 |
| DE3625869A1 (en) | 1987-02-05 |
| GB2178435A (en) | 1987-02-11 |
| FR2585710B1 (en) | 1990-08-03 |
| GB2178435B (en) | 1989-12-13 |
| DE3625869C2 (en) | 1994-08-04 |
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