DK156853B - FILL-FREE, HYDROLYTIC STABLE, BIOLOGICAL INERT, TRANSPARENT CONTACT LENS AND PROCEDURE FOR PREPARING THE SAME - Google Patents

Description

DK 156853 B

The present invention relates to a filler-free, hydrolytically stable, biologically inert, transparent contact lens which is capable of transporting oxygen in an amount sufficient to meet the requirements of the human cornea and is made of a material based on polysiloxanes. which contact lens is characterized in that the material consists of a three-dimensional network polymer made by polymerization of a poly (organosiloxane) monomer which is α, ω-linked through divalent hydrocarbon groups to activated polymerizable unsaturated groups, which monomer has the general formula: R1 f R3> 1 R1 iii

A - R - Si - - O - Si - O - Si - R - A

I, I4 l2

R ^ R L R

Wherein A represents an activated, unsaturated group, R represents a divalent hydrocarbon radical having from 1 to 22 hydrocarbons, R, R, R and R, which are the same or different, each represents a monovalent hydrocarbon radical or a halogen-substituted monovalent hydrocarbon radical, each having from 1 to 12 carbon atoms, and m is an integer from 0 to ca. 800, the polymerization being optionally carried out in the presence of one or more comonomers selected from 1 aversion esters of acrylic and methacrylic acid, styrene compounds and N-vinylpyrrolidone.

The invention further relates to a method for producing a filler-free, flexible, hydrolytically stable, biologically inert, transparent, elastic, blpd contact lens capable of carrying oxygen, in which an initiator selected from radical initiators and UV initiators is used to initiate polymerization, which process is characterized in that a poly (organosiloxane) monomer of the general formula as set forth in claim 1, wherein m is about 50 to approx. 800, and one or more monomers selected from 1 avere of esters of acrylic and methacrylic acid, styrene compounds and N-vinylpyrrolidone, the polysiloxane monomers are mixed with the comonomers, the material is placed in a centrifugal mold contact contact lens, tower while centrifugal, forming a filler-free, flexible, hydrolytically stable, biologically inert, transparent, elastic, soft contact lens capable of carrying oxygen.

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The use of ~ afsiloxane polymers for the production of optical contact lenses is convenient. The convenience is due to the great ability to transport oxygen and the relative softness of the polysiloxanes in general. However, the tear strength and tensile strength of polysiloxane elastomers are generally poor, and consequently filler is used to increase elastomer strength. U.S. Patent Nos. 3,996,187, 3,996,189, 3,341,490, and 3,228,741 disclose contact lenses made from poly (organosiloxanes) containing filler. The contact lenses of the invention have sufficient tear strength and tensile strength that no filler is required.

In the aforementioned United States Patent Nos. 3,996,187 and 3,996,189 bMkrivës'contacts made from reinforced polysiloxanes. The lenses contain various refractive index polysiloxanes, similar to that of the silica filler, so that an optically clear silica-filled silicone elastomer can be formed from aryl and alkyl siloxanes.

The material contains from 5 to 20% silica. The silica is used as mentioned for the sake of strength. The present invention does not use any filler for reasons of strength since the present material has sufficient strength without filler.

U.S. Patent No. 3,341,490 discloses contact lenses made from mixtures of siloxane copolymers containing reinforcing silica filler. As mentioned, the contact lenses of the present invention contain no filler.

U.S. Patent No. 3,228,741 discloses contact lenses which are 25-made from silicone rubber, especially carbon dioxide-substituted poly-siloxane rubber. The silicone material contains filler, such as pure silicon dioxide, to control the flexibility, flexibility and elasticity of the lenses. The present contact lenses require no filler.

U.S. Patent No. 3,808,178 discloses a polymeric material containing a polymethacrylate chain of relatively short poly (organosiloxane, xane) ester side chains on the chain polymer. No crosslinking is involved as the monomers described in the patent are monofunctional, ie. has only one functional group on each monomer. To achieve cross-linking, according to column 5 of the patent, various 35 monomers having more than one functionality must be added to obtain cross-linking.

In the present invention, crosslinking is achieved since each siloxane monomer is difunctional, i.e. each monomer contains two functional groups, preferably two methacrylate groups, which result

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3 cross-linking. In addition, contact lenses made from the polymers disclosed in U.S. Patent No. 3,808,178 would not carry enough oxygen, whereas the contact lenses of the invention would carry a sufficient amount of oxygen to meet the needs of the human horn.

U.S. Patent No. 3,518,324 relates to vulcanization for the production of silicone rubber, while the present invention relates to contact lenses made by polymerizing specific monomers.

U.S. Patent No. 3,878,263 discloses a configuration which may be in î î A f ...

.. v v. vΊ

R 5 may be monovalent hydrocarbons, R 'may be a monovalent hydrocarbon, 20 c may be zero, but when c is zero, Z may be OR "".

Z is an important component since it is used for crosslinking of the chains. Therefore, the monomers used in the contact lens of the present invention cannot be derived from the aforementioned patent.

U.S. Patent No. 2,770,633 discloses 1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane, one of the preferred monomers used in the contact lens polymer of the present invention. This is shown in column 1, line 63 of the United States patent, when R is vinyl. However, US Patent No. 2,770,633 describes only the monomer, and not a polymer made therefrom or even a contact lens made from the polymer. In fact, it would not be worthwhile in connection with Patent No. 2,770,633 for the monomer to be polymerized as it would not perform its function as a binder.

U.S. Patent No. 2,906,735 discloses a reaction between an alkylsiloxane and acrylic acid or a methacrylic acid resulting in a disiloxane terminated with acrylate groups. U.S. Patent No. 2,906,735 does not disclose the polymers used in the contact lens of the present invention.

U.S. Patent No. 2,922,807 discloses disiloxanes with acryloxy-4

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or methacryloxy groups bonded to the silicone through divalent alkyl radicals having 2-4 carbon atoms.

None of the above patents prejudices the present invention and even less the preferred reactions of the present invention, which is that 1,3-bis (4-methacryloxybutyl) tetramethyldisiloxane is reacted with preferably octamethylcyclo-tetraziloxane to form the preferred monomer. This preferred monomer is then polymerized to the preferred one. crosslinked polymer. In addition, none of the prior art discloses the new contact lenses of the present invention made from the present polymers.

U.S. Patent No. 3,763,081 describes in the relevant part polymerization of an unsaturated siloxane which is somewhat difficult to polymerize since a double bond of this type of monomer is generally not particularly active. Both high temperature and a peroxide catalyst or platinum catalyst must be used to complete this type of reaction. See, e.g. column 4, lines 55-46 of the patent. Specifically, in connection with the present reaction, the monomer materials have activated, unsaturated groups bonded to the siloxane through divalent hydrocarbon groups, while there are no activated unsaturated groups attached to the siloxane according to the above patent.

U.S. Patent No. 2,865,885 discloses in the relevant part a non-activated vinyl group as shown in column 1, lines 25-30 of the patent. The reason why the double bond in the patent is not "active" within the meaning of the present application is that the double bond is bound either to sulfur or to oxygen. In the present invention, this same position would have a {} carbonyl group. This would make the double bond active as (-C-) 30 defined by the present invention. Since the reactivity ratios in patent specification 2,865,885 are so different, i.e. that the double bond of said patent is inactive, as defined in the present invention, it would be very difficult to obtain an acceptable copolymerization reaction using the formulas of said patent in comparison with the active double bond of the present invention. invention which is readily copolymerized. In the context of the present invention, the vinyl group is "activated" to facilitate radical polymerization. The formula in column 1, 5

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Units 25-30 of Patent No. 2,865,885 are not suitable for radical polymerization due to lack of resonance, but rather are suitable for ion polymerization due to the polar nature of the substituents. Therefore, it would be extremely difficult, if at all possible, to form the compounds from this patent, so as to be included in the contact lens of the present invention. The compounds formed in accordance with the above patent are not hydrolytically stable due to the presence of the silicone-nitrogen bond in the formula. The present invention cannot use a compound which is not hydrolytically stable. In addition, the products of the hydrolysis in the disclosed patent could be detrimental to human eyes, especially the amines. Also in column 3 of Patent No. 2,865,885, the bond is an amine bond to the double bond, and in the present invention this bond is always an alkyl bond. Therefore, Patent No. 2,865,885 does not disclose the present monomers.

Of the relevant ones! US Patent No. 2,793,223, Example 5 of column 3, Union 30-41, discloses that a phenyl group is attached to the siloxane. Therefore, this material will be very hard and opaque. It will be unsuitable for contact lenses which should be transparent. In addition, contact lenses made of polymers made from the monomers described in Patent No. 2,793,223 would not adequately transport oxygen due to the presence of phenyl groups on the siloxane as shown in Example 5 of said patent, whereas contact lenses prepared from the existing polymers will carry oxygen sufficiently to meet the requirements of the human cornea.

When the term "activated" is used herein in connection with the term "unsaturated group", it is meant an unsaturated group which is activated by having a substituent which facilitates radical polymerization. These activated unsaturated groups are polymerized to form the polymers for the contact lens of the present invention. The activated groups used herein are preferably suitable for polymerization under mild conditions, such as ambient temperature.

By the term "a poly (diorganosiloxane) end-linked through 35 divalent hydrocarbon groups to a polymerized activated unsaturated group", it is meant that the poly (organosiloxane) compound described herein has been attached to a compound having a divalent hydrocarbon group such as methylene or propylene, etc., and that there at each end of 6

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this compound is attached to an activated, unsaturated group, such as methacryloxy, etc., and this is then the most preferred monomer. When the monomers are polymerized (i.e., crosslinked), the activated, unsaturated groups (radical polymerization) are polymerized and the monomers form three-dimensional polymers which constitute the material from which the contact lenses are made.

As a result of the presence of activated, unsaturated groups, the monomers used in accordance with the present invention are readily polymerized to form three-dimensional polymer networks which allow the transport of oxygen and are optically clear, strong and can be rendered blood or Harde.

When the term monomer is used herein, polyisoxanes, which are terminated with polymerizable unsaturated groups, are also included. The method for extending the monomer's silox fraction is herein referred to as siloxane ring entry. The chain length of the polysiloxane central unit of monomers can be as high as 800 or more.

When the term polymerization is used herein, it is meant to polymerize the double bonds in the polysiloxanes which are terminated with polymerizable unsaturated groups, resulting in a cross-linked three-dimensional polymer network.

The relative hardness (or softness) of the contact lenses of the present invention may be varied by decreasing or increasing the molecular weight of the monomeric poly (organosiloxanes) terminated by the activated unsaturated groups or by varying the percentage of the co-monomer. When the ratio of organosiloxane units to final units is depleted, the softness of the material is depleted. Conversely, when the ratio is reduced, the rigidity and hardness of the material increase.

The network polymer of the contact lens of the invention may comprise 10 to 90% by weight of the described (organosiloxane) monomers and 90 to 10% by weight of the copolymerizable monomers. The preferred contact lenses formed by these copolymers are filler-free, flexible, hydrolytically stable, biologically inert, transparent, elastic and soft, as well as having the ability to transport oxygen.

The three-dimensional network polymer is readily prepared by conventional radical polymerization technique. The monomers of organosiloxane alone or in the presence of comonomers can be combined with ca.

0.05 to approx. 2% by weight of a radical initiator is heated to a temperature of approx. 30 ° C to approx. 100 ° C to initiate and complete the polymerization.

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The polymerizable monomers, i.e. The poly (organosiloxanes), with or without comonomers, may preferably be subjected to UV light irradiation at room temperature in the presence of appropriate activators such as benzoin, acetophenone, benzophenone and the like for a period sufficient to form a three-dimensional polymer network.

The polymerization can be expressed directly in contact lens forms, or discs, rods or sheets can be molded, which can later be machined into a fine shape. Preferably, the polymerization is expressed while the material is centrifugal molded, as described in U.S. Patent No. 3,408,429.

It is well known that the ability of polysiloxanes to transport oxygen in comparison with conversion contact lens polymers, such as polymethylmethacrylate (PMMA) or polyhydroxyethylmethacrylate (PHEMA) is substantially greater. The ability to transport oxygen to the contact lenses of the invention can be varied by changing the percentage content of siloxane units. Eg. For example, a high percentage content of siloxane units results in a product which has a higher ability to transport oxygen, while a 1% percentage content of polysiloxane units results in a material with less ability to carry oxygen.

The poly (organosiloxanes), i.e. the monomers used are those having the formula: 1 {3S 1 R R R1 i i i

A-R-Sl - O-Si - O-Si-R-A

25 I2 I4 I2

R R RZ

µm wherein A represents an activated unsaturated group, R represents a divalent hydrocarbon radical having from 1 to 22 hydrocarbons, R, R, R and R, which are the same or different, each representing a monovalent hydrocarbon radical or a halogen-substituted monovalent hydrocarbon radical, each having from 1 to 12 carbon atoms, and m is an integer from 0 to ca. 800th

35 m can advantageously vary in the range 50 to approx. 200. However, the area of m can be larger, such as preferably 50 to 800. If a hard contact lens is desired, the area should be less than 25.

When the term "blood" is used herein to describe contact lenses- 8

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In accordance with the present invention, it is believed that in the above formula after polymerization, m is greater than 25, preferably from ca.

50 to approx. 800. When "hard" is used herein to describe the contact lenses of the present invention, it is believed that m in the above formula after polymerization is less than 25.

A is preferably one of the following: 2-cyanoacryloxy 0 CH9 = C - tt - 0 - 2 in

C s N

acrylonitrile CH2 = ç -

15 C s N

acrylami do 0

II

CH2 = CH - C - NH - 20 acryloxy-in CH2 = CH - C - 0 -25 methacryloxy 0 11 CH0 = C - C - O - 2 in ch3 styryl CH = CH? Φ 35 and N - vinyl - 2 - pyrrolidinone - x - yl, 9

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wherein x may be 3, 4 or 5 4 4 xh 2 - ch 2 CH 2 = CH - - [- \ - CH 9

Il 2 0 3

More preferably, A represents acryloxy or methacryloxy. However, André 10 groups containing activated unsaturation can be used with ease, as such groups are well known to those skilled in the art. Most preferably, A represents methacryloxy or acrylamido. R can conveniently be an alkylene radical. Therefore, R is preferably methylene, propylene, butylene, pentamethylene, hexamethylene, octamethylene, dodecylmethylene, hexadecylmethylene and octadecylmethylene; arylene radicals such as phenylene, biphenylene and corresponding alkylene and arylene radicals. More preferably, R represents an alkylene radical of about 1, 3 or 4 carbon atoms. Most preferably, R represents an alkylene group having from about 3 to 4 12 3 4 carbon atoms, e.g. butylene. R, R, R and R preferably represent alkyl radicals having from 1 to 12 carbon atoms, for example methyl, ethyl, propyl, butyl, octyl, dodecyl and the like; cycloalkyl radicals, e.g. cyclopenethyl, cyclohexyl, cycloheptyl and the like; mononuclear and binuclear aryl radicals, e.g. phenyl, naphthyl and the like; aralkyl radicals, e.g. benzyl, phenethyl, phenylpropyl, phenylbutyl and the like; alkyryl radicals, e.g. tolyl, xylyl, ethylphenyl and the like; halogenaryl radicals, such as chlorophenyl, tetrachlorophenyl, difluorophenyl and the like; halogen substituted lower alkyl radicals with up to approx. four alkyl carbon atoms, such as fluoromethyl and fluoropropyl. More preferably, R 2, R 4, R 2 represent methyl radicals and phenyl radicals, and R, R, R 3 and R 4 most preferably represent methyl radicals.

Those with activated unsaturated groups terminated polysiloxanes, ie.

the monomers used in the present invention can be prepared by appropriately substituted disiloxane, e.g. 1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane is equilibrated with an appropriate amount of a cyclic diorganosiloxane, e.g. hexamethylcyclotrisiloxane; tetraphenylcyclotetrasiloxane and the like, present

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10 room of an acid or base catalyst. The degree of flexibility, physical properties such as tensile strength, tensile modulus and percent elongation determine the amount of cyclic diorganosiloxane which is equilibrated with the disiloxane. By increasing the amount of cyclic siloxane, one increases m.

The reaction between a cyclic diorganosiloxane and disiloxanes, although not specifically described for disiloxanes used in the present invention to provide the activated unsaturated groups as end groups for polysiloxanes, is a conventional reaction and is .g. described by Kojima et al., "Preparation of Polysiloxanes Having Terminal Carboxyl or Hydroxyl Groups", J. Poly. Sci., Part A-1, Vol. 4, pp. 2325-27 (1966) or Martin's U.S. Patent No. 3,878,263, incorporated herein by reference.

The following reactions illustrate the most preferred materials of the present invention. 1,3-Bis (hydroxyalkyl) tetramethyl disiloxane dimethacrylates are prepared by the following reactions: (1) Esterification with acryloyl or methacryloyl chloride or anhydride; eg. which follows with methacryloyl chloride CH, CH, 20 I 3 1 3

HO - (CH24-n Si - 0 - Si - {CH

ch3 ch3 25 + n is preferably 1, 3 or 4 n is most preferred = 3 or 4 CH, 0 ...

I 3 II

2 CH 2 = C - C - Cl CH, O ^ CH, CH, 0 CH, 35 | 3 I 3 I 3 II I 3

C - C - O 4CH2-fn Si - 0 - Si - * CH24-n O - C - C

ch 2 ch 3 ch 3 ch 2 40 n is preferably 1, 3 or 4 n is most preferred 3 or 4 (2) Another particularly preferred method of preparing 1,3-bis (hydroxyalkyl) tetramethyl disiloxane dimethacrylates is by transesterification with methyl methacrylate: 11

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ch, o CH, CH, I 31 I 3 I 3

2 CH2 = C - C - O - CH3 + HO 4CH2 -> n Si - O - Si - (CH

5 I CH3 CH3 CH, O CH, CH, O CH, 10 I 3 11 I 3 | 3 II I 3 CH 2 = C - C - 0 4CH 2 - f Si - O - Si - f CH 2 - f 2 O - C - C = CH 2 ch 3 ch 3

Then the number of siloxane groups between the two methacrylate end groups can be pegged from 2 to 2 + 4X by a ring-opening reaction with 20 X moles of octamethylcyclotetrasiloxane in the following manner: CH, 0 CH, CH, 0 CH, 1 3 II l 3 I 3 H 1 3 CH 2 = C - C - O - (CH 2 - f Si - O - Si - (CH 2 O - C - C = CH 2) I in ch 3 ch 3 n is preferably 1, 3 or 4 n is most preferred = 3 or 4 + CH, CH, i3 i3 CH, - Si - 0 - Si - CH, 3 II 3

X mol O O

I I

CH, - Si - 0 - Si - CH, 40 3 | I 3 ch3 ch3 Ψ 45 CH, 0 CH, / δζ \ CH, O CH, I 3 II I 3 (I 3 λ I 3 11 I 3

C - C - O -fCH, -k Si - O f— Si-O 4 Si 4CH, -l · O - C - C

n 2 n i Γ i 71 2 "" CH, CH, \ CH, y CH, CH,

50 L 0 v now J L

\

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12 n is preferably = m is preferably = 1, 3 or 4 50 to 800 n is most preferred = (cross-linking / polymerization) 5 3 or 4 ψ (three-dimensional network) 1 r \ 0 CH, CH, CH, 0

10 I II | 3 I 3 I 3 II

CH, - C - C - 0 - {CH, -} - Si - 0— Si - 0 — Si - {CH, -} · 0 - C - C - CH, 3 l 2 n III 2 "I 3 1 CH , CH, CH, i} 3 V 3 3 \ 15 CH2 CH2 0 CH, fCH,] CH, 0

Il I 3 l 3 I 3 II

CH3 - C - C - O - f CH2 - f Si - O-- Si - O - Si - f CH2 O - C - C - CH3 CH, CH, CH, 3, 3 JL 3 ^ m CH, CH , 25 I 2 I 2 CH, CH, I 2 I 2 -0-CC-CH, CH, -C-C-0 ~

Il \ 3 3 ï II

30 0 | j0 n is preferably = 1, 3 or 4; n is most preferred = 3 or 4; m is preferably = 50 to 800 Poly (the organosiloxanes) which are α, ω-terminally linked through divalent hydrocarbon groups to an activated, unsaturated group, i.e. The monomers in question are generally clear, colorless liquids whose viscosity depends on the value of m. These monomers can be easily cured into molded forms by conventional methods such as UV polymerization or by the use of radical initiators plus heat. Illustrative radical initiators which may be used are bis (isopropyl) peroxydicarbonate, azo-bisisobutyronitrile, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, benzoyl peroxide, tert-butyl peroxypivalate and the like. In order to further regulate the properties of the polymers in the contact lenses of the present invention, a mixture of monomers comprising low value monomers and high value monomers having a hpj value 13 can be polymerized.

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of m. When m has a low value, ie. below 25, the resulting contact lenses are relatively rigid, hydrolytically stable, biologically inert, transparent, and have the ability to transport oxygen, and they do not require any filler to improve the mechanical properties. The monomers have a relatively low molecular weight and, as a result, the viscosity is sufficiently low for the lenses to be readily prepared by centrifugal molding, e.g. ca. 3 cSt. When m has a relatively high value, ie over 25, the resulting contact lenses become relatively soft, flexible, hydrolytically stable, biologically inert, transparent, resilient and capable of transporting oxygen, and they do not require any filler to improve mechanical properties. The monomers should preferably have a sufficiently low molecular weight such that the viscosity is sufficiently low for the monomers to be centrifugal cast, e.g. ca. 175 St or less, painted in Gardner viscosity rpr. m is preferably approx. The poly (organosiloxanes) may be copolymerized with one or more co-monomers selected from lower esters of acrylic and methacrylic acid, styrene compound and N-vinylpyrrolidone.

The comonomer may be any polymerizable monomer of the above kind which is readily polymerized by radical polymerization, and is preferably a monomer containing an activated vinyl group.

By adding comonomers one can improve particularly valuable properties. For example, buttons made from copolymers of the subject polysiloxane monomers and tetrahydrofurfuryl methacrylate 1 can be peeled off for contact lenses than buttons made of poly (organosiloxane) monomers alone. The wettability of contact lenses made from the polysiloxanes can be substantially increased by copolymerizing the available monomers with n-vinylpyrrolidone.

Illustrative comonomers which may be conveniently used in accordance with the present invention are: 30 Esters of methacrylic acid and acrylic acid, such as: methyl, ethyl, propyl, isopropyl, n-butyl, hexyl, heptyl, aryl, allyl, cyclohexyl, 2-hydroxyethyl, 2- or 3-hydroxypropyl, butoxyethyl methacrylates; and propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, heptyl, aryl acrylates.

Mono- or di-esters of the above-mentioned acids can be used with polyethers of the formula given below:

H0 (CnH2n0) q H

14

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where n is a number from 1 to approx. 12, preferably 2 or 3, and q is a ta! from 2 to approx. 6, preferably 2 to 3.

Other comonomers may include: styrene compounds, such as styrene, divinylbenzene, vinylethylbenzene, vinyl toluene, etc.

Nitrogen-containing monomers such as N-vinylpyrrolidone can also be used.

The lower the value of m in the formula for the present monomers, the more compatible are the monomers with the above comonomers. The advantages of using the contact lenses according to the present invention, which are made from the monomers described herein, are numerous. Eg. are (1) the advantages of using activated vinyl end groups to cure the siloxane material, with (a) the cure activity system providing rapid cure at room temperature if appropriate initiators are used. Room temperature is preferred. This is desirable as the preferred casting method is centrifugal casting. (B)

No filler is required to obtain physical strength, which is otherwise common with most silicone resins. This is valuable as the use of filler requires other possibly undesirable materials to be added to the composition to correct the refractive index. (2) In addition, the contact lenses made from the polymers are capable of carrying oxygen. The human cornea requires fi? 7 approx. 2 x 10 cm / (s.cm. Atm) oxygen through the contact lenses, as reported by Hill and Fatt, "American Journal of Optometry and Archives of the American Academy of Optometry," Vol. 47, p. 50, 1970. When m is at least approx. 4, the siloxane chain of the present composition is sufficiently long to exceed the corneal oxygen transport requirements. However, in specific situations, m may be as low as 0. Depending on the unique properties of the contact lenses, m may be sufficiently large to provide sufficient ability to carry oxygen while retaining their valuable properties in terms of elasticity, tear strength, flexibility. , fun and softness.

When the term "ability to transport oxygen" or "oxygen transport" is used in the context of the present invention, it is believed that the material itself enables sufficient oxygen transfer to meet the oxygen requirements required for the human cornea.

-6 3

As mentioned, the oxygen requirements of the human cornea are approx. 2 x 10 cm / 2 (s.cm .atm.). The ability to transport oxygen is determined by a particular method of operation described in connection with Example 9. (3) These 15

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Lenses are hydrolytically stable, which means that when the contact lenses are placed in an aqueous solution, e.g. in pjet, or during the disinfection step, ie. water plus water, the lenses will not change chemical composition, ie. hydrolyzes, which would cause the lenses 5 to change shape, which in turn would result in an undesired change of optics. (4) The more preferred contact lenses according to the present invention are additionally elastic. When the term "elastic" is used here, it is believed that the lenses, after being deformed, will quickly return to their original shape. (5) The lenses are preferably made by centrifugal casting. eg. by the method described in U.S. Pat. No. 3,408,429. Monomers having too high viscosity cannot be centrifugal. However, in general, the higher the molecular weight of the monomers, the greater the chain length, ie. the greater is the value for m, and as a result, the more valuable are the properties of the preferred contact lenses of the invention made by these monomers. The longer the chain length and the higher the molecular weight, the higher the viscosity of the monomers. However, if centrifugal casting is to be used, the viscosity of the monomers must be such that this material can be centrifugal cast. The monomers of the present invention may have molecular weights which are sufficiently high to give all of the desirable properties as they are polymerized, but sufficiently low to allow the compositions to be centrifuged while still in monomeric form. The preferred weight average value of the molecular weight is from ca. 4000 to 60,000 25 for the monomers used in the invention. (6) The most preferred contact lenses of the present invention should be images. By using the term "blood" in this specification, it is meant in the preferred embodiment that the lenses should have a Shore hardness of approx.

60 or less on the A scale. (7) The preferred contact lenses of the present invention should be flexible. When the term "flexible" is used herein, it is meant that the contact lenses are capable of being bent or bent backward relative to themselves without breaking.

The poly (organosiloxane) monomer used to prepare the polymer from which the contact lens according to the invention is manufactured has in the most preferred embodiment the following formula: 16

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R1 f R3 Ί R1

I I I

A - R - Si - 0 - Si - 0 - Si - R - A

Wherein A is selected from methacryloxy and acryloxy, R represents an alkylene radical having from about 1 3 to approx. 4 carbon atoms and m is from ca. 50 to 10,800.

The most preferred contact lenses according to the invention are as mentioned

-S

filler-free and have an oxygen transport value of at least approx. 2 x 10 "

ISLAND ISLAND

and are hydrolytically stable, biologically inert, transparent and resilient and have a bloodiness of preferably 60 to 15 or less on Shore Hardness Scale A. The most preferred Shore Hardness should be 25 to 35 on the A scale.

To further illustrate the physical properties of the most preferred contact lenses according to the present invention, the tensile elastic modulus should be approx. 400 g / mm.mm or less. Both the Shore-20 hardness and the module are related to the comfort the lenses provide when worn on the human eye.

Another advantage of the preferred soft contact lenses of the present invention is that the lenses can be made so large as to cover the entire cornea of the eye, resulting in greater comfort. Hard contact lenses, such as PMMA lenses, must be made smaller because of their poor oxygen transport ability. Furthermore, the larger the lenses, the easier it is to locate the optical center of the lenses. The larger the lens, the easier it is to maintain the optical axis required in the manufacture of special lenses for people with 30 special eye problems, e.g. for people with astigmatism. Another advantage of the preferred soft lenses of the present invention is that these lenses have a softness similar to that of HEMA lenses, but in addition, and what is the most important, greater oxygen permeability, i.e. that they are capable of carrying more oxygen. HEMA lenses are not oxygen permeable or capable of carrying oxygen to the extent necessary to meet the requirements of the human cornea.

The following examples serve as illumination, but not 17

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limit of the present invention. All parts and percentages therein are by weight, and all viscosities are ground at 25 ° C unless otherwise specified.

EXAMPLE 1,557 g of 1,3-bis (4-hydroxybutyl) tetramethyl disiloxane, 634 g of pyridine and 2 liters of hexane were added to a 5-liter reaction flask with mechanical stirrer and drying. The mixture was cooled to 0 ° C and 836 g of methacryloyl chloride was then added dropwise. The mixture was stirred continuously overnight. The reaction solution was extracted sequentially with 10% aqueous solutions of HCl and NHg to remove excess reagent and pyridine hydrochloride. The resulting solution of the product in hexane was quenched with anhydrous MgSO 4, filtered and the solvent removed under reduced pressure. Approximately approx. 459 g of 15 (55% yield) of 1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane.

The structure was confirmed by infrared spectra, proton magnetic resonance spectra and elemental analysis. IR spectra did not show any intense hydroxyl band between 3100 and 3600 cm cm "but exhibited strong methacrylate absorptions at 1640 and 1720 cm" *. PMR spectra were consistent with the proposed structure: O <j®3

“H2 iN X + 2 -Si - O

\ / ° I 7> = C CH 'H1 ^ CH3 _ | 2,3,3-bis (4-methacryloxybutyl) tetramethyldiloxane.

35 18

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Proton ppm Inteorated area Hultiplicity H1 7.05 1 singlet 6.50 1 singlet H3 3.00 3 singlet 5 H4 5.15 2 triplet H3 2.7 4 multiplet H6 1.65 2 triplet H7 1.20 6 singlet 10 Elemental analysis gave 13.6% Si (calculated 13.5%), 58.1% C (calculated 57.9%) and 9.4% H (calculated 9.2%). The product was a clear, goodbye, smelly liquid.

Example 2 15 The liquid product of Example 1 was placed between glass disks with 0.2% benzoin methyl ether and irradiated with UV light at room temperature. A color pulp, optically clear, hard, highly crosslinked film is obtained. The following is a presentation of the crosslinked polymer.

20 2 (three-dimensional network) in CH2 CK2 n CH. CH.

O j 3 | 3 O

CH3-C-C-O-CH2-fCH2 -) - 2CH2-Si-O-Si-CH2-fCH24-2CH2-O-C-C-CH3 | ch3 ch3 | CH2 ch2

O CH. CH. ISLAND

Il I 3 | 3 || CH3-C-C-0-CH 2 FCH 2 F2CH2-Si-0-Si-CH 2 (CH 2 -) - 2CH2-0-C-C-CH3

35 * I

ch3 ch3 ch2 ch2 ÇH2 CH2 ^ ° -C-Ç-CH3 ch.-c-c-o—

Ji î 3 | Il

O i j O

40 19

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Example 3 489.75 g of octamethylcyclotetrasiloxane and 10.25 g, 3-bis (4-methacryloxybutyltetramethyldisiloxane were added to a reaction stirrer. About 25 g of Fuller soil and 1.35 ml of conc. H2 SO4 were mixed. and added to the vessel under continuous stirring while drying N 2 bubbled through the reaction mixture. The batch was heated to 60 ° C and stirred for 2 days, whereupon the viscous liquid was neutralized with Na 2 CO 3, diluted with hexanes and filtered with hexane / monomer solution. The water was quenched with MgSO 4 (anhydrous) and the solvent was removed under reduced pressure Low molecular weight unreacted cyclic siloxanes were removed by heating the monomer to 110 ° C at 0.2 mm Hg in a rotary evaporator. odorless, color pulp, clear liquid with 8.5 St viscosity in Gardner viscosity tube The monomer comprised about 260 repetitive Me2SiO units Liquid collected during evaporation of the product showed no methacrylate absorption in IR spectra and could not be cured.

IR spectra of the monomer showed poor methacrylate absorption and wide siloxane absorptions between 1000 and 1100 cm 2, suggesting linear poly (dimethylsiloxanes) having the following formula: 20 (v

ÇH-3 O CH, CH, CH, O CHQ

I 3 H | 3 I 3 I 3 II f 3

C ~ C-O-CH ~ -fCH, -KCH, -Si - O-Si-O-Si-CHO-fCHO

II 2 2 2 2 I I I 2 2 2 2 (| ch2 CH3 CH3 CH3 CH2 \ / 25 _ 260

Example 4

Films of the liquid product of Example 4 were cast between glass disks by adding 0.2% bis (isobutyl) peroxydicarbonate to the monomer and heating for 0.5 hours at 40 ° C, 0.5 hours at 60 ° C and 15 minutes. at 80 ° C 30 The glass disks were separated. The films were then kept at 80 ° C for 15 min.

Colorless, optically clear, odorless, elastic and strong films are obtained, as shown by the three-dimensional network polymers below. The following physical properties were measured with an "Instron" test apparatus ASTM D1708, no conditioning, using standard "meat bone" test pieces cut from 0.2 mm thick film. The speed was 0.635 cm / min. was used for all examples where tensile strength, tensile modulus and elongation were painted.

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20 (three-dimensional network) 5 î i

CK / \ CH

* CH, / CH, \ CH, i * '8 I 3/1 I 3 çl

CHo-C-C-O-CHo * £ CH A CH -Si-0-S ± -0-Si-CH ~ {CH _} - CH-0-C-C-CH

3 | 2 2 2 2 j I | I j i 2 2 2 «3 10 j ch3 rà§H3

I I

CH CH.

2 2

CH, / chA CH

1K o | 3 I 3 \ I 3 O

CH3-C-C-O-CH24CH2 ^ 2CH2-Si-O ^ Si-d-Si-CH24CH2 ^ 2CH2-O-C-C-CH3

CH. \ CH J CH

3 \ ^ 260 3

CH, CH

2 ° | 2 | 2 fH2®8 - ° -g-j-CH3 CH3-h-0 "25 2

Tensile breaking limit 150 g / mm.mm 2

Tensile module 72 g / mm.mnr 30 Extension 177%

Example 5 The liquid product of Example 3 was placed together with 0.2% di (sec-butyl) peroxydicarbonate in a suitable contact lens centrifugal mold and centrifugal molded under a polymerization conditions for a contact lens as described in U.S. Patent No. 3,408,429. The lens was optically clear, elastic and strong.

21

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Example 6

Ca. 97.3 g of octamethylcyclotetrasiloxane, 2.7 g of 3-bis (4-methacryloxybutyl) tetramethyl disiloxane and 0.6 ml of trifluoromethylsulfonic acid were added to a pressure flask, sealed and shaken for 24 hours. The obtained viscous monomer liquid was neutralized with sodium carbonate and diluted with hexanes. The monomer-hexane solution was washed with water, quenched with anhydrous MgSO4 and the solvent removed under reduced pressure. The volatiles were removed from the monomer at 0.2 mm Hg and 110 ° C using a screened film distillation apparatus (wiped film 10 still). Shark pressure gel permeation chromatography of the product showed essentially complete removal of low molecular weight volatiles.

The product was a colorless, clear, odorless liquid with a 4.4 St viscosity measured in Gardner viscosity rpr. The polymer set forth below comprises ca. 200 repeated f ^ SiO units.

The 15 1 IR spectra were similar to those recorded in Example 3.

(three-dimensional network) 20 µl fo ÎH3 / îHA ÎH3 qF2 CH-cXo-CH 4CHA2CH -Si-0-Si-0-Si.-CH24CH242CH2-0-Î-C-CH3 3 j 2 2 * \ \\ '\ 25 \ CH3 VH340oH3 f I CH0 CH 2

fs ifS \ f 3 O

CH-C1-O-CH 4CHA2CH -Si-O-Si-d-Si-OH ^ CH i ^ -O-i-C-CHj

30 3 2 2 H UL

3 \% oo 5 CH0 CH I 2

I 2 CH

CH j 2 I CH -Ç-C-0 * ~ 35 ^ 0-g-C-CH3 3 | § 22

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Example 7

Using methods similar to those used in Example 4, the films of the viscous liquid product of Example 6. The films were surveyed, ASTM D1708, thereby obtaining the following results: 2 Tensile breaking limit 159 g / mm.mm 2

Tensile module 104 g / mm.mm

Extension 151%

Example 8 The viscous liquid product prepared in Example 6 was mixed with 2.0% benzoin butyl ether. Ca. 30 µΐ of the mixture was placed in a rotary contact lens mold under Ng atmosphere. After 20 minutes of irradiation with UV light, a cured contact lens was obtained. The lens formed was optically clear, elastic and strong.

15

Example 9

To 90 parts of the liquid product obtained in Example 3 were added 10 parts of allyl methacrylate monomer and 0.4 parts of t-butyl peroctoate. The reaction mixture was placed in a molding cell which was later placed in an oven at 80 ° C for half an hour. Then the temperature was raised to 100 ° C and kept at 100 ° C for 1 hour. An optically clear film was taken from the cell and kept at 80 ° C for 15 minutes.

The above described was repeated by reacting the product of Example 3 with several other monomers as shown in Table 25 I. The percentages shown in Table I are the percent of comonomer used. The properties of the comonomers are listed in Table I.

As illustrated in Table I, it is an object of the present invention to point out the tensile strength and elongation while maintaining sufficient oxygen transport capacity. One problem with the silicon polymers known in the art is that these polymers are not particularly strong and have poor tear strength and poor tensile strength. One of the problems with PHEMA (control) is that contact lenses made from this material do not have the necessary oxygen transport properties to meet all the requirements of the human cornea. As mentioned, the oxygen requirement of the human cornea is approx. 2 x 10 cm / (s.cm.atm.). Table I illustrates the effect of the present comonomers on the strength of the polymers used in the contact lens of the invention. The tensile strength is improved by using the present mono-23

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mers. As far as the module is concerned, it is most preferred that the module be below 300, so that a contact lens is obtained. Therefore, it is usually the case that the lower the module, the smoother the contact lens is.

With respect to the extension, it is generally preferred that the extension be as high as possible.

With regard to oxygen transport, it is desirable that this value is highest possible. This value should be greater than the oxygen value required by the human cornea.

The tensile strength, modulus and elongation tests are, as mentioned, made with an "Instron" test apparatus ASTM D1708, using standard "meat bone test pieces cut from 0.2 mm thick film.

No conditioning is done and the speed is 0.635 cm / min.

The oxygen transport value was determined by the following technique.

This sample measures the oxygen permeability of a material while it is moistened with water. This is a prerequisite to reproduce the same conditions that prevail in the human eye when provided with a contact lens.

Two chambers filled with water at 32 ° C are connected by a common passage over which the material to be examined is placed. Nitrogen gas purged water is pumped into both chambers until the oxygen concentration is very low (about 0.04 ppm). Air-containing water (oxygen concentration about 8 ppm) is then fed into the lower chamber. In the upper chamber is arranged an oxygen sensitive electrode which measures the oxygen diffusion from the lower chamber through the membrane to be examined and to the upper chamber. This measures the oxygen transport value of the material covering the passage between the two chambers.

30 35 24

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TABLE I

Breakage- Approximate Limit Module Extend- * apparently 2 2 (g / mm.m} (g / mm.mm) else (%) 02 transport value 5 _ PHEMA 40 40 150 4 x 10 "7 AHyi _7 10 methacrylate 10% 71 143 65 62 x 10 •

Butoxyethyl methacrylate 10% 26 42 100 50 x 10 "15 Butoxyethyl methacrylate 30% 31 38 136

Cyclohexyl 7 methacrylate 10% 70 75 131 56 x 10

Ethyl methacrylate 10% 67 80 136 54 x 10 7

Methyl methacrylate 10% 100 90 145

Ethyl hexyl 7 acrylate 10% 50 73 110 54 x 10 10 Ethyl hexyl acrylate 30% 41 69 105 n-bu acrylate 10% 49 79 110 35 n-bu acrylate 30% 30 79 58 50 x 10 "7 bu acrylate 10% 51 78 116 58 x 10" 7 bu acrylate 30% 37 80 82 40 3 * Apparent And Transport Value = cm (02) 2 pp.cm.

45

Example 10 58.3 g of 1,3-bis (4-methacryloxybutyl) tetramethyldisiloxane, 41.7 g of octamethylcyclotetrasiloxane, 1 ml of conc. H2 SO4 and 2 g of Fuller soil are placed in a pressure flask. After two days equilibrium, the mixture was neutralized with Na 2 CO 3, filtered, diluted with hexanes, washed with water and dried, and the solvent removed under reduced pressure.

25

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The monomer product, illustrated below, was a low viscosity, odorless liquid that was measured in Gardner viscosity tubes.

10 g of monomer product was mixed with 0.1 wt% benzoin methyl ether and 0.1 wt% azobis (isobutyronitrile). The initiator monomer solution was poured into button molds and cured for 20 minutes. under UV light in nitrogen gas atmosphere and then for 30 min. at 80 ° C in air. The buttons were optically clear, color feather, hard and cool. Contact lenses were removed from these buttons. The following is the formula for the above monomer: 10 ÇHo / K \ ch? 8 I 3 I 3 l 3 8 CH -Ç-C-O-CH {CHa ·}. CH 2 -Sî-oUsi-O- Si-CH ΧΟΗ.λ CH 0-C “C-CHo 3 || 2 2 2 2 | T | 1 \ 2222 | 3 CH CH3 Vçh ^ c ^ ch2 15

Example 11 7 g of the monomer product prepared in Example 10 and 3 g of N-vinylpyrrolidone were mixed with 0.1% by weight benzoin methyl ether and 0.1% by weight azobis (isobutyronitrile). The initiator-monomer-comonomer solution was cured as described in Example 10. The copolymer buttons obtained were optically clear, colorless, hard and tough. The rotation of the contact lens buttons was significantly easier than the rotation of the buttons in Example 10.

Example 12 30% tetrahydrofurfuryl methacrylate (TFM) was copolymerized with 70% monomer of Example 10 in appropriate forms. The buttons obtained were optically clear, colorful, tough and cool. The TFM copolymer buttons were machined by turning to contact lenses.

30

Example 13 99.3 g of octamethylcyclotetrasiloxane, 0.7 g of 1,3-bis (4-methacryloxybutyl) tetramethyldisiloxane and 0.3 ml of trifluoromethylsulfonic acid were placed in a pressure flask. The bottle was sealed and shaken for 5 days. The obtained monomer liquid was neutralized with sodium carbonate and diluted with hexanes and filtered. The monomer / hexane solution was washed with water, dried over MgSO 4 and the solvent removed under reduced pressure. Volatiles were removed from the prepolymer at a pressure of 0.2 26

DK 156853 B

mm Hg and 110 ° C. High pressure gel permeation chromatography of the product showed that all low molecular weight volatiles were removed. The product was a color peel, clear, odorless liquid with very high viscosity and with approx.

800 repeated Me ^ SiO units. The following is a formula for the above-mentioned momons: CH, fcH \ CH, o I 3 I 3 \ I 3 9 CH -C-î-O-CH2- (CH2 ^ 2CH2-Si-ci-Si-C -So-CH24CH2 ^ 2CH2-0-bC-CH3

| H, Ah UhJ in CH

10 2 3 \ Jéoo 3 2

Example 14

Films were prepared from the viscous liquid product of Example 13 using procedures similar to those used in Example 4. The films were examined to obtain the following results. The following is a presentation of the crosslinked polymer.

in (three-dimensional network)}

I I

CH2 CH2 CH3 / ch \ CH3 CH2-Ç -? - 0-CH24CH2 ^ 2CH2- | i-oi-k-0-Si-CH24CH2 ^ 2CH2-0 -? - Ç-CH3 \ CH \ CH, / CH \ I î 25 CH2 CH2 ch_ / ch \ CH,

0! 3 I 3 \ I 3 O

CH2-C-C-O-CH24CH2 ^ 2CH2-Si-O-Si-.d-Si-CH24CH2 ^ 2CH2-O-C-C-CH3 CH, \ CH, / CH, 30 5 \ 7800 5 CH CH, | 2 | 2 CH, CH, I I 2 a ^ O - ^ - C-CH3 CH ^ -C - ^ - O ^ 35 ^ 2

Tensile breaking limit 34 g / mm.mm

Tensile module 38 g / mm.mm

Elongation 208% 2

Claims (15)

A filler-free, hydrolytically stable, biologically inert, transparent contact lens capable of carrying oxygen in an amount sufficient to meet the requirements of the human cornea, and made of a material based on polysiloxanes, FEATURED BY MATERIALS A COMPOSITION OF A THREE-DIMENSIONAL NETWORK POLYMER MADE BY POLYMERIZATION OF A POLY (ORGANOSILOXAN) MONOMER THAT IS α, ω-BONDED BY DIVENTAL HYDROCAR HYDROGEN GROUPS FOR ACTIVATED POLYMERIZABLE UNSATURED GROUPS, WHICH MONOMER HAS THE GENERAL FORMULA: R1 f bA R1 35 lll ao A - B - Si - O - Si - O - Si - E - A ^ 2 ^ 4 ^ 2 R ^ R4 J RZ v 'Itl DK 156853 B wherein A represents an activated, unsaturated group R represents a divalent 12 3 4 hydrocarbon radical having from 1 to 22 carbon atoms, R, R, R and R, which are the same or different, each representing a monovalent hydrocarbon radical or a halogen-substituted monovalent hydrocarbon radical, each having from 1 to 12 carbon atoms, and me is an integer from 0 to approx. 800, the polymerization being optionally carried out in the presence of one or more comonomers selected from 1 aversion esters of acrylic and methacrylic acid, styrene compounds and N-vinylpyrrolidone. 2. Contact lens according to claim 1, characterized in that A is selected from 2-cyanoacryloxy, acrylonitryl, acrylamido, acryloxy, methacryloxy, styryl, N-vinyl-2-pyrrolidinon-3-yl, N-vinyl-2-pyrrolidinone-4 -yl and N-vinyl-2-pyrrolidirion-5-yl, and R represents an alkylene radical and R 1, 2 3 4 R, R and R represent an alkyl radical having from 1 to 10 carbon atoms. 15 3. Contact lens according to claim 2, characterized in that m is a number from 0 to approx. 200th 4. Contact lens according to claim 3, characterized in that m is a number from 0 20 to approx. 50th 5. Contact lens according to claim 4, characterized in that m is a number from 0 to approx. 25th 6. Contact lens according to claim 1, characterized in that the comonomer is selected from styrene and N-vinylpyrrolidone. 7. Contact lens according to claim 1, characterized in that the comonomer is selected from allyl methacrylate, butoxyethyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, methyl methacrylate, ethyl hexyl acrylate, n-butyl acrylate and butyl acrylate. 8. Contact lens according to claim 1, 2, 6 or 7, characterized in that m is a number from approx. 25 to approx. 800. 35 9. Contact lens according to claim 8, characterized in that it is manufactured by centrifugal molding. DK 156853 B 10. Contact lens according to claim 8, characterized in that m is a ta! from approx. 50 to approx. 800th 11. Contact lens according to claim 10, characterized in that the alkylene radical 5 has from ca. 1 to approx. 4 carbon atoms. 12. Contact lens according to claim 11, characterized in that the alkylene radical has from approx. 3 to approx. 4 carbon atoms. 13. Contact lens according to claim 12, characterized in that R1, R2, R3 and R4 are selected from a methyl radical and a phenyl radical. 14. Contact lens according to claim 13, characterized in that R1, R2, R3 and R4 denote methylated radii. 15 A process for producing a filler-free, flexible, hydrolytically stable, biologically inert, transparent, resilient, soft contact lens capable of carrying oxygen, using an initiator selected from radical initiators and UV initiators to initiate polymerization, Characterized in that a poly (organosiloxane) monomer of the general formula set out in claim 1, wherein m is approx. 50 to approx. 800, and one or more monomers selected from 1 avere of esters of acrylic and methacrylic acid, styrene compounds and N-vinylpyrrolidone, the polysiloxane monomers are mixed with the comonomers, the material is placed in a centrifugal cast contact lens form, while centrifugal-stubby, forming a filler-free, flexible, hydrolytically stable, biologically inert, transparent, elastic, soft contact lens capable of carrying oxygen. 30 Copenhagen, 35