Polysiloxane composition and contact lens

The invention relates to a filler-free contact lens from a homo- or copolymer prepared from polysiloxane having terminal active groups as a monomer.

The Polysiloxanpolymerisat is by polymerizing a or more poly (diorganosiloxane) produced monomers, in the <i>α</i>- and <i>ω</i>-Endstellung Via divalent hydrocarbon groups to activated polymerizable unsaturated Groups are attached. Optionally, the polymerization polymerizable in the presence of one or more free radically Comonomers are performed. polymerization leads to a three-dimensionally crosslinked polymer or copolymer.

The use of siloxane polymers for the preparation of optical lenses offers several advantages which on the good transport capacity for oxygen and the relative softness of Polysiloxanes are due. Tear resistance and tensile strength polysiloxane elastomers, however, are generally poor, so that fillers are used to improve their strength. In U.S. Patents 39 96 187, 39 96 189, 33 41 490 and 32 28 741 are contact lenses made from poly (organosiloxanes), the contain fillers described. Tear resistance and tensile strength the contact lenses made from the polymers according to the invention are the other hand, such that no fillers are required.

As mentioned are known from US Patents 39 96 187 and 39 96 189 known contact lenses from solidified polysiloxanes. The lenses contain various polysiloxanes having refractive indices equal that of the silica filler, so that and from aryl Alkyl-siloxanes, an optically clear, silica as a filler can be formed containing silicone elastomer. The material contains 5 to 20% silica. The silica is, as mentioned, used for solidification. The polymer according to the invention however, contains no fillers, since it even without this adequate Rigidity.

From US-PS 33 41 490 are contact lenses from mixtures of Siloxane copolymer that for solidifying silica fillers contain known.

From US-PS 32 28 741 are contact lenses made of silicone rubber, Known especially hydrocarbyl Polysiloxangummi. The material contains fillers such as pure silica, to regulate flexibility, pliability and elasticity of the lenses.

From US-PS 38 08 178 (equivalent to DE-AS 23 63 627), is a Polymer material known that a Polymethacrylatgrundkette with relatively short Poly (organosiloxane) containing ester side chains. Networking is not available, because the said monomers are monofunctional, ie each monomer has only one functional group. Column 5 this US-PS 38 08 178 is carried out so that, to a cross-linking added to achieve, other monomers with more than one functionality would have to be. In contrast, according to the invention, a scored networking because each siloxane monomer is difunctional, ie, two functional groups, preferably two methacrylate groups, contains resulting crosslinking. Moreover, by the contact lenses made from the polymers of US-PS 38 08 178 insufficient oxygen is transported, while the Contact lenses from the polymers according to the invention as much oxygen transport, as required by the human cornea.

From US-PS 35 18 324 a vulcanization is for preparing known from silicone rubber, whereas the present invention Contact lenses produced by polymerizing special monomers are concerns.

From US-PS 38 78 263, a configuration is known, the the following formula can have:&lt;!-- <img id="6/1" wi="000" he="000" img-content="cf" /> --&gt;wherein R may be monovalent hydrocarbons;R '<hor nb="59">can be a monovalent hydrocarbon;</hor><i>c</i><hor nb="59">may be zero, in which case, however, at least a Z 'must be OR' ''.</hor>

Z is a substantial amount, because it of the networking Chains used. The monomers used according to the invention are in this US-PS 38 78 263 is not called.

In US-PS 27 70 633, the 1,3-bis (4-methacryloxybutyl) is - tetramethyl-disiloxane, one of the preferred according to the invention Monomers described, namely, at column 1, line 63, provided that R Is vinyl. However, from this US-PS 27 70 633, only the monomer known, while the present invention not only the monomer, but in particular relates to the polymer and polymerization of the monomer according to this US patent would result in a product that the desired function of a lubricant could not exercise.

From US-PS 29 06 735 a reaction between a Alkylsiloxane and acrylic or methacrylic acid, which for a Disiloxane containing terminal acrylate leads, known. The polymers according to the invention of this US patent application No. 29 06 735 not known.

From US-PS 29 22 807 are Disiloxanes, acryloxy or Methacryloxy groups via a divalent alkylene radical having from 2 to 4 carbon atoms contain bonded to the silicon, known.

The invention is disclosed in any of these references, and in particular, the preferred reactions according to the Invention, namely the reaction of 1,3-bis (4-methacryloxybutyl) - tetramethyl disiloxane with preferably octamethylcyclotetrasiloxane to form the preferred monomer therein not described. According to the invention this is preferred Monomer then polymerized to the preferred cross-linked polymer. In particular, however, the contact lenses according to the Invention of these polymers in any of these references described.

The US-PS 37 63 081, for example, column 4, lines 55 to 46, states that the polymerization of unsaturated is siloxane somewhat difficult, since a double bond such a Monomer is generally not very active. Therefore need both high temperatures as well as a peroxide catalysis or a platinum catalysis be used to perform such a reaction to the end. The monomers used according to the invention have activated unsaturated groups via a divalent hydrocarbon group attached to the siloxane, while from this US-PS 37 63 081 monomers known no such activated unsaturated groups bonded to the siloxane.

The US-PS 28 65 885 describes a vinyl group, which, however, As seen from column 1, lines 25 to 30, it appears not "active" in Purposes of the present patent application is, because the double bond is attached to either sulfur or oxygen. According to the invention would be in the same position, for example, a carbonyl&lt;!-- <img id="8/1" wi="000" he="000" img-content="cf" /> --&gt;whereby the double bond is activated. Because of these different reactivities, it is difficult according to the aforementioned US-PS 28 65 885 to obtain a copolymerization, while the active double bond according to the invention easily copolymerized. According to the invention, the vinyl group "activated" so that a Radical polymerization is promoted. The in column 1, Lines 25 to 30, the mentioned US-PS 28 65 885 mentioned formula must not have any free radical polymerization due to lack of resonance, but rather because of the polarity of the substituents a ionic polymerization received. The preparation of compounds according to the invention should therefore, if possible, extremely to be difficult. In addition, according to this US patent are 28 65 885 compounds produced due to the presence of the Silicon / nitrogen bond hydrolytically unstable in the formula.

According to the invention, however, a hydrolytically unstable compound are not used. Further, the products may a such hydrolysis, in particular the amines, to the human Eye be harmful. Also shows column 3 US-PS 28 65 885 an amine linkage to the double bond, while in the compounds according to the invention at this point always an alkyl stands. The monomers used according to the invention are therefore Also from this US-PS 28 65 885 unknown.

According to US-PS 27 93 223, Example 5 in column 3, lines 30 to 41, a phenyl group is bonded to the siloxane. Therefore the material must be very hard and dull. Such material is not suitable for contact lenses, as these be transparent have to. Moreover, would of the polymers from the monomers this US patent are prepared, because produced contact lenses the presence of the phenyl group to the siloxane insufficient transport oxygen, while from the polymers according to the Invention contact lenses manufactured transport as much oxygen, as required by the human cornea.

The invention is accordingly based on the object, provide contact lenses based on siloxane polymer, the good mechanical properties without an additive is required of fillers, and good transparency, have high oxygen permeability.

The problem is solved according to claim. 1

By "active" or "activated" in connection with a "Terminal group" is an unsaturated group a Substituent which is a radical polymerization Be understood favors. This active or activated unsaturated groups polymerize to form the Novel polymers. Preferably allow this Groups, a polymerization under mild conditions, such Ambient temperatures.

The statement "a poly (diorganosiloxane), the end positions in the through a divalent hydrocarbon group a polymerizable activated unsaturated group bound is "is to be understood that the poly (organosiloxane) to divalent Hydrocarbon groups, such as methylene or propylene, etc., is bound and that at each end of this compound activated unsaturated group such as methacryloxy, etc. attached is. Then, when the monomers polymerized (ie, crosslinked) are, the activated unsaturated groups are polymerized form (free radical) and the monomers three-dimensional polymers, the material selected from the Contact lenses are prepared form.

The monomers used according to the invention are due to the Presence of activated unsaturated groups easily form three-dimensionally crosslinked polymers derived from the transport Allow oxygen and opti cally are clear and firm and to Request can be made as soft or hard polymers, polymerizable.

By "monomer" So are polysiloxanes having terminal polymerizable activated unsaturated groups to understand. The extension of the siloxane content of the monomer is referred to as Siloxanringeinsatz. The chain length of the central polysiloxane of monomers can be up to 800 or above.

The term "polymerization" is meant polymerization of the double bonds of the polymerizable unsaturated groups at the ends the polysiloxanes to form a three-dimensionally crosslinked Polymer leads, be understood.

The hardness (or softness) of the contact lenses of the present invention Polymer can be obtained by lowering or increasing the molecular weight of monomeric poly (organosiloxane) with the terminal activated unsaturated groups or by Varying the amount of comonomer can be varied. with increasing Ratio of organosiloxane to Endgruppeneinheiten increases the softness of the material, and vice versa increases the rigidity and hardness of the material, if this Ratio decreases. The preferred contact lens may by resulting from the US-PS 34 08 429 known rotational molding (spin casting) getting produced.

The invention also relates to polymers of a poly (organosiloxane), the in the <i>α</i>.<i>ω</i>-positions Through a divalent hydrocarbon group bound to an activated unsaturated group is provided with one or more monomers, the low molecular weight Esters of acrylic or methacrylic acid, styryl, allyl or vinyl compounds could be. These copolymers are three-dimensionally crosslinked, clear and firm and can be used for the production of Contact lenses are used.

The copolymers according to the invention preferably contain 10 to 90 parts by weight of one or more of the above-described monomeric Organosiloxanes and 90 to 10 parts by weight of the polymerizable comonomers. The preferred copolymers formed from these Contact lenses are unfilled, fortune oxygen transporting, flexible, hydrolytically stable, biologically inert, transparent, elastic and soft.

The three-dimensionally cross-linked polymer according to the invention can easily by conventional methods of radical polymerization getting produced. The Organosiloxanmonomeren can together alone or in the presence of comonomers with about 0.05 to about 2 wt .-% of a radical chain initiator, are heated to a temperature of about 30 to about 100 ° C, to initiate the polymerization and complete. The polymerizable monomers, ie the poly (organosiloxane), can be with or without comonomers, preferably at room temperature in the presence of suitable activators such as benzoin, acetophenone, Benzophenone and the like., For a sufficient time to a three-dimensionally to form cross-linked polymer, with UV light are irradiated.

The polymerization can be carried out directly in contact lens mold or it may plates, rods or sheets are prepared from which then a desired molded article is produced. Preferably the polymerization takes place while the material in the the mentioned US Patent No. 34 subjected to rotational molding described 08,429 becomes.

The transport capacity for Oxygen of polysiloxane is considerably better than that the polymers conventionally used for contact lenses, such as polymethyl methacrylate (PMMA) or polyhydroxyethylmethacrylate (PHEMA). The oxygen transport capacity of the materials according to the Invention, by changing the amount proportion of siloxane be varied. In a high percentage of siloxane units can the product better to carry oxygen than for a lower percentage.

According to one embodiment of the invention, optical Contact lenses from three-dimensionally cross-linked polymers of Poly (organosiloxanes) which in <i>α</i>- and <i>ω</i>Position through a divalent Hydrocarbon group to a polymerizable activated unsaturated group bound manufactured. The used Poly (organosiloxanes), ie the monomers have the formula:&lt;!-- <img id="13/1" wi="000" he="000" img-content="mf" /> --&gt;in which A is an activated unsaturated group, R is a divalent Hydrocarbon radical having 1 to 22 carbon atoms, R₁, R₂, R₃ and R₄ are the same or different and is a monovalent Hydrocarbon radical or a halogen-substituted monovalent hydrocarbon radical having 1 to 12 carbon atoms mean and <i>m</i> is zero or more.

Suitably <i>m</i> in the range of 50 to about 200. The Section <i>m</i> but can also be greater, preferably 50 to 800, his or <i>m</i> may have a value of about 800th If the production a harder contact lens is desired, has <i>m</i> expedient a value below 50th

When the term "soft" in relation to the contact lenses is used according to the invention, this means that <i>m</i> in the above formula between about 50 and about 800 lies. When the term "hard" in connection is used with the contact lenses according to the invention, so this means that <i>m</i> in the above formula after polymerization is smaller than the 50th

Preferably A is&lt;!-- <img id="14/1" wi="000" he="000" img-content="mf" /> --&gt;&lt;!-- <img id="14/2" wi="000" he="000" img-content="mf" /> --&gt;&lt;!-- <img id="14/3" wi="000" he="000" img-content="mf" /> --&gt;&lt;!-- <img id="14/4" wi="000" he="000" img-content="mf" /> --&gt;&lt;!-- <img id="14/5" wi="000" he="000" img-content="mf" /> --&gt;&lt;!-- <img id="15/1" wi="000" he="000" img-content="mf" /> --&gt;N-vinyl-2-pyrrolidinone<i>x</i>yl, wherein <i>x</i> 3, 4 or 5.&lt;!-- <img id="15/2" wi="000" he="000" img-content="mf" /> --&gt;

Preferably A is acryloxy or methacryloxy. However, Other groups that an activated unsaturation are included, as are known to the skilled person may be used. Particularly preferred are methacryloxy and acrylamido.

R may preferably be an alkylene group such as methylene, Propylene, butylene, pentamethylene, hexamethylene, octamethylene, Dodecylmethylen, Hexadecylmethylen or Octadecylmethylen, or an arylene radical such as phenylene, biphenylene, and a corresponding be alkylene or arylene. Particularly R is an alkylene radical having 1, 3 or 4 carbon atoms, and in particular an alkylene group having 3 or 4 carbon atoms, For example, butylene.

R₁, R₂ and R₄ are preferably alkyl groups having 1 to 12 carbon atoms, for example, methyl, ethyl, propyl, butyl, Octyl, dodecyl, etc .; Cycloalkyl, for example, Cyclopentyl, cyclohexyl, cycloheptyl, etc .; mononuclear or more membered aryl radicals such as phenyl, naphthyl etc .; Aralkyl, such as benzyl, phenylethyl, Phenylpropyl, phenylbutyl, etc .; Alkaryl, for example, Tolyl, xylyl, ethylphenyl, etc .; haloaryl as chlorophenyl, tetrachlorophenyl, difluorophenyl, etc .; halogen-substituted low molecular weight alkyl radicals having up to about 4 alkyl carbon atoms, such as fluoromethyl and fluoropropyl. Preferably are R₁, R₂, R₃ and R₄ are methyl radicals and / or phenyl radicals, and in particular methyl radicals.

The monomers used according to the invention, that the polysiloxanes having terminal activated unsaturated groups, can be prepared by reacting the substituted disiloxane, For example, 1,3-bis (4-methacryloxybutyl) -tetramethyl- disiloxane, with a suitable amount of a cyclic Diorganosiloxane, for example hexamethylcyclotrisiloxane, Octaphenylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, 1,2,3-trimethyl-1,2,3-triphenylcyclotrisiloxane, 1,2,3,4-tetramethyl-1,2,3,4-tetraphenylcyclotetrasiloxan and the like., In Presence of an acidic or basic catalyst to the Equilibration converts. The softness, physical properties such as tensile strength, modulus, and percent elongation, are decisive for the amount of cyclic Diorganosiloxane that used along with the disiloxane becomes. by increasing the amount of cyclic siloxane<i>m</i> elevated.

The production of disiloxanes generally, according although not specifically for of the invention for the preparation of polysiloxanes with the activated unsaturated terminal groups used Disiloxanes, for example, Kojima et al. in "Preparation of polysiloxane Having terminal carboxyl or hydroxyl groups, J. Poly. Sci., Part A-1, Volume 4, pages 2325-27 (1966) "or in US-PS 38 78 263 described.

The following reaction equations illustrate the preparation the most preferred materials according to the invention. 1,3-bis (hydroxyalkyl) tetramethyl disiloxane dimethacrylates be prepared according to the following reaction equations:

(1) esterification with acryloyl or methacryloyl chloride or anhydride, for example with methacryloyl:&lt;!-- <img id="17/1" wi="000" he="000" img-content="cf" /> --&gt;

(2) A further preferred process for the preparation of 1,3-bis (hydroxyalkyl) tetramethyl disiloxane is dimethacrylates transesterification with methyl methacrylate: &lt;!-- <img id="18/1" wi="000" he="000" img-content="cf" /> --&gt;<i>n</i><hor nb="59">preferably = 1, 3 or 4</hor><i>n</i><hor nb="59">in particular = 3 or 4</hor>

The number of siloxane groups between the two terminal Methacrylate can then by a ring-opening and Einsetzungs- increased reaction with X moles octamethylcyclotetrasiloxane be from 2 to 2 + 4X according to the following equation: &lt;!-- <img id="19/1" wi="000" he="000" img-content="cf" /> --&gt;<i>n</i><hor nb="59">preferably = 1, 3 or 4</hor><i>n</i><hor nb="59">in particular = 3 or 4</hor><i>m</i><hor nb="59">preferably 50 or 800</hor>

The poly (organosiloxanes) with in <i>α</i>- and <i>ω</i>Position on a divalent hydrocarbon group bound activated unsaturated Groups, ie the monomers used according to the invention, are generally clear, colorless liquids whose viscosity from the value of <i>m</i> depends. These monomers can by easily conventional methods such as UV polymerization, or using , Cured free radical initiators plus heat to castings will. Examples of useful free radical initiators are Bis (isopropyl) peroxydicarbonate, azobisisobutyronitrile, acetyl peroxide, Lauroyl peroxide, decanoyl peroxide, benzoyl peroxide, t-butyl peroxypivalate and the same.

The properties of the polymers according to the invention further to control, can be a mixture of monomers having a low value of <i>m</i> and monomers having a high value of <i>m</i> polymerize. If <i>m</i> a low value, that is below 50, has, the obtained Contact lenses, ie the polymers, relatively hard, oxygen-transporting, hydrolytically stable, biologically inert, and transparent and do not need fillers to improve the mechanical Characteristics. The monomers have a relatively low molecular weight, and its viscosity is therefore sufficiently low, ie example, is about 0.03 cm / s, so that the lenses easily can be made by rotational molding. If<i>m</i> a relatively high value, ie, about 50, has to be relatively soft, oxygen transporting, flexible, hydrolytically stable, biologically inert transparent, elastic contact lenses, ie, polymers obtained, the no fillers for improving the mechanical properties need. The monomers preferably have such a low Molecular weight that the viscosity is sufficiently low for the is rotational molding, for example, about 175 cm / s or including measured in Gardner viscosity tubes is. Preferably is <i>m</i> 50 to 800.

According to a further embodiment of the invention Polymers from monomers, poly (organosiloxanes), the terminally through a divalent hydrocarbon group to an activated unsaturated group are bonded and comonomers contain an activated vinyl group produced.

The comonomer can be any polymerizable monomer which slightly out radical may be subjected, and is preferably a monomer containing a vinyl group activated contains. The addition of comonomers, certain desirable characteristics can be improved. For example, of copolymers of the poly (siloxanes) and tetrahydrofurfuryl produced buttons handles easier to contact lenses be as buttons, ie, polymers of monomeric polysiloxanes are made alone. The wettability of contact lenses, ie, polymers which are prepared from the polysiloxanes can be considerably increased by the monomers, according to the Invention with N-vinylpyrrolidone copolymerized.

Examples of useful comonomers are:

The derivatives of methacrylic acid, acrylic acid, itaconic acid and crotonic:

Methyl, ethyl, propyl, isopropyl, n-butyl, hexyl, Heptyl, aryl, allyl, cyclohexyl, 2-hydroxyethyl, 2- or 3- Hydroxypropyl, butoxyethyl methacrylate; Propyl, isopropyl, Butyl, hexyl, 2-ethylhexyl, heptyl, aryl acrylate; propyl, Isopropyl, butyl, hexyl, 2-ethylhexyl, heptyl, Arylitaconat; and propyl, isopropyl, butyl, hexyl, 2-ethylhexyl, Heptyl, aryl-crotonate.

Mono- or di-esters of the above acids with polyethers of general formula:

HO (C_<i>n</i>H₂_<i>n</i>O)_<i>O</i>H

in the <i>n</i> a number from 1 to about 12, preferably 2 or 3, and <i>O</i> is a number from 2 to about 6, preferably 2 or 3, may be prepared be used.

Other comonomers can be:

Styryls, such as styrene, divinylbenzene, vinylethylbenzene, vinyltoluene etc.

Also allyl monomers such as Diallyldiglykoldicarbonat, allyl cyanide, Allyl chloride, diallyl phthalate, allyl bromide, diallyl fumarate and diallyl carbonate can be used.

Furthermore, nitrogen-containing monomers, such as N-vinyl pyrrolidone, 3-Oxybutylacrylamid etc. be used.

The lower the value of <i>m</i> according to the formula of the monomers the invention is to so compatible they are with the aforementioned Comonomers.

The advantages of contact lenses, ie, the polymers according to the Invention, which are obtained from the above monomers, are numerous. For example, there are (1) the benefits of using of terminal activated vinyl groups to cure the Siloxane material (a) in the high reactivity, the rapid curing allowed at room temperature, as long as suitable initiators be used, with room temperatures being preferred. This is desirable since the preferred preparation of the lenses by Rotomolding done; (B) that to achieve a good mechanical Strength not as with most silicone resins Fillers are required, requires the use thereof, that possibly undesirable materials be added need to correct the refractive index. (2) In addition, assets produced from the polymer according to the invention Contact Lenses to carry oxygen. The human Cornea requires, as of Hill and Fatt, American Journal of Optometry and Archives of American Acedemy of Optometry, Vol 47, page 50, 1970, executed an oxygen transport through the contact lens of about 2 × 10^-6 cc / (Sec cm² atm). If<i>m</i> at least is about 43, is the Siloxane chain long enough to an oxygen transport, is greater than corresponds to the requirements of the cornea, to ensure. In special cases<i>m</i> However, to down amounted to 0th Due to the excellent properties of the contact lenses, ie, the polymers according to the invention, can <i>m</i> be so great that a sufficient amount of oxygen is transported while at the same time the elasticity, obtained tensile strength, flexibility and softness stay.

By "oxygen carrying capacity" or "oxygen transport" is to be understood that the material sufficient oxygen passes through itself to the required for the human cornea Volume supply of oxygen. This amount, as mentioned, about 2 × 10^-6 cm³ / (sec cm² atm). The Oxygen transport capacity was to a related Example test procedures described 9 determined. (3) The lenses are hydrolytically stable, ie when an aqueous solution, for example, eye or during their disinfection, ie water plus heat, are exposed, they alter their chemical composition not, that is, they are not subject to hydrolysis, through which they their shape, thereby changing their optical properties would. (4) The preferred contact lenses according to the invention are also elastic, which means that after deformation of the lenses they quickly assume its original shape again. (5) The lenses preferably by rotational molding, for example by the in the US-PS 34 08 429 method described, hergstellt. monomers have too high a viscosity, are not suitable for the Rotational molding. The higher the molecular weight of the monomers, the greater is generally the chain length, ie, the value of <i>m</i>and Accordingly, the better are the properties of the preferred contact lenses, from these monomers getting produced. The larger the chain length and the higher the molecular weight is, the higher the viscosity of the monomers. but the monomers must have a viscosity such that they are suitable for rotational molding. The monomers used have molecular weights that are so high that they the lend, yet low polymer all the desired properties enough that they are suitable for rotational molding, if they are still present in the monomeric form. The preferred average molecular weight of the monomers is between about 4000 and 60 000. (6) The most preferred contact lenses according to the invention are soft contact lenses, is under "soft" to understand that the lenses a Shore Hardness of about 60 or less, preferably 25 to 35 according to have the A scale. (7) The preferred contact lenses according to the invention are flexible; the term "flexible" to understand is that it is folded or bent himself can be without breaking.

The most preferred contact lens of the invention is unfilled from an oxygen-transporting, flexible, hydrolytically stable, biologically inert, transparent, soft polymer of a poly (organosiloxane), the terminal- through a divalent hydrocarbon group to a polymerizable activated unsaturated group bound is of the formula:&lt;!-- <img id="25/1" wi="000" he="000" img-content="cf" /> --&gt;wherein A is methacryloxy or acryloxy, R is an alkylene radical has 3 or 4 carbon atoms and <i>m</i> a value of about 50 to 800 has.

The tensile modulus of elasticity is the most preferred Contact lenses according to the invention at about 400 g / mm² or including. Both the Shore hardness and modulus make the lenses comfortable to wear on the eye of the wearer.

A further advantage of the preferred soft contact lenses according to of the invention is that these lenses made large enough may be to cover the entire cornea of ​​the eye, which the makes wearing more comfortable. Hard contact lenses, such as lenses PMMA must, because of their low oxygen transport assets be made smaller. The larger the lenses, the easier it is to adjust its optical center is. The larger the Lens is, the easier it is also that of optical axis adjust, the particular for the manufacture of SPIE-savers lenses with Eye problems, such as astigmatism, is required. Another Advantage of the preferred soft lenses according to the invention is that they are not just as soft as HEMA lenses, but also and in particular are oxygen permeable, ie to transport more oxygen assets. HEMA lenses are not to the extent that the requirements of the human cornea correspond, oxygen permeable conveyor capable of transporting oxygen.

The following examples illustrate the invention. information parts and percentages are by weight and viscosities were measured at 25 ° C, unless otherwise specified.

example 1

557 g of 1,3-bis (hydroxybutyl) tetramethyl disiloxane, 634 g dry pyridine and 2 liters of hexane are introduced into a 5-liter reaction flask introduced with a mechanical stirrer and drying tube. The mixture is cooled to 0 ° C, after which dropwise 836 g of methacryloyl be added. The mixture is overnight constantly stirred. The mixture is successively aqueous strength with 10% Solutions of HCl and NH₃ extracted to remove excess reactants and to remove pyridine. The thus obtained Solution of the product in hexane is dried with anhydrous MgSO₄ and filtered, and the solvent is removed under reduced Print separated. This gives about 459 g (yield 55%) of 1,3-bis (4-methacroxybutyl) tetramethyl disiloxane. The structure is by infrared spectra, proton magnetic resonance spectra and elemental analysis confirmed. The infrared spectrum shows no intense Hydroxyl band 3100-3600 cm^-1But strong Methacrylatabsorptionen at 1640 and 1720 cm^-1, The proton magnetic resonance spectra confirmed the assigned structure:&lt;!-- <img id="27/1" wi="000" he="000" img-content="cf" /> --&gt;

<imgref idrefs="27/2" />1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane

&lt;!--

<img id="27/2" wi="000" he="000" img-content="tb" />

--&gt;

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, colorless, good-smelling liquid.

example 2

The liquid product of Example 1 is mixed with 0.2% benzoin methyl ether placed between glass plates and at room temperature with irradiating UV light. This gives a colorless, optically clear, hard, highly crosslinked film. The three-dimensionally cross-linked polymer has the following formula:&lt;!-- <img id="28/1" wi="000" he="000" img-content="cf" /> --&gt;

example 3

489.75 g of octamethylcyclotetrasiloxane and 10.25 g of 1,3-bis (4- methacryloxybutyl) tetramethyl disiloxane are added to a reaction vessel introduced with a mechanical stirrer. Approximately 25 g fuller's earth and 1.35 ml of concentrated H₂SO₄ are mixed together and continuous stirring in the vessel is introduced while dry N₂ is passed through the reaction mixture. The feed is heated to 60 ° C and stirred for two days, after which the viscous liquid neutralized with Na₂CO₃, diluted with hexanes and filtered becomes. The solution of hexanes and monomer is washed with water, dried with anhydrous MgSO₄, and the solvent is under reduced pressure separated. Low molecular weight unreacted cyclic siloxanes are removed by passing the monomer is in a Rotary evaporator at 1.33 x 10^-4 bar (0.2 mm Hg) to 110 ° C. The product obtained is an odorless, colorless, clear liquid measured with a viscosity of 8.5 cm² / s in Gardner viscosity tubes. The monomer containing about 260 recurring&lt;!-- <img id="29/1" wi="000" he="000" img-content="cf" /> --&gt;During the evaporation of the product collected liquid shows no Methacrylatabsorptionen not in the IR spectrum, and could be cured.

The IR spectrum of the monomer shows a slight Methacrylatabsorption and wide Siloxanabsorptionen 1000-1100 cm^-1 what on linear poly (dimethylsiloxane) having the following formula indicating:&lt;!-- <img id="29/2" wi="000" he="000" img-content="cf" /> --&gt;

example 4

be from the liquid product of Example 3, between glass plates Films cast by the monomer 0.2% bis (isobutyl) peroxydicarbonate adding and ½ hour at 40 ° C, ½ hour at 60 ° C and ¼ hour heated to 80 ° C. The glass plates are of one another, separated. The films are then kept at 80 ° C for 15 minutes. You get colorless, optically clear, odorless, elastic and resistant films from a three-dimensional crosslinked polymer specified below Formula. On an Instron tester ASTM D 1708, without conditioning, are using standard "dog bone" - Samples cut from 0.2 mm thick films were determined the following physical properties. The speed is 0.63 cm / min. This test is in all the examples where tensile strength, modulus, and Break are determined, applied.&lt;!-- <img id="30/1" wi="000" he="000" img-content="cf" /> --&gt;tensile strenght<hor nb="75">150 g / mm²</hor>tensile modulus<hor nb="75"> 72 g / mm²</hor>strain<hor nb="75">177%</hor>

example 5

The liquid product of Example 3, together with 0.2% Di (sec-butyl) peroxydicarbonate in an Kontaktlinsenrotationsgußform introduced and by rotomolding in polymerization polymerized to form a lens, such as described in US-PS 34 08 429th The lens is optically clear, elastic and firm.

example 6

Approximately 97.3 g of octamethylcyclotetrasiloxane, 2.7 g of 1,3-bis (4- methacryloxybutyl) tetramethyl disiloxane and 0.6 ml of trifluoromethylsulfonic acid are introduced into a pressure bottle, and the bottle is sealed and shaken for 24 hours. The viscous obtained monomer liquid is neutralized with sodium carbonate and diluted with hexanes. The monomer / hexane solution is washed with water, dried with anhydrous MgSO₄, and the solvent is removed under reduced pressure. Volatile materials are at 1.33 x 10^-4 bar (0.2 mm Hg) and 110 ° C in a distilling apparatus separated wiped from the monomer. The Hochdruckgelpermeationschromatographie the product shows that low molecular weight volatile material completely separated substantially becomes. The product is a clear, colorless, odorless Liquid having a viscosity of 4.4 cm² / s measured, in Gardner viscosity tubes. The polymer of the following Formula contains about 200 repeating&lt;!-- <img id="31/1" wi="000" he="000" img-content="cf" /> --&gt;The IR spectra are identical to those of Example 4. Fig. &lt;!-- <img id="32/1" wi="000" he="000" img-content="cf" /> --&gt;

example 7

are from the viscous liquid product of Example 6 after the procedure of Example 4 Films prepared. The Movies tested according to ASTM D1708 with the following results:

tensile strenght<hor nb="75">159 g / mm²</hor>tensile modulus<hor nb="75">104 g / mm²</hor>strain<hor nb="75">151%</hor>

The IR spectra were similar to those in Example 3. FIG.

example 8

The viscous liquid product of Example 6 is 2.0% Benzoinbutyläther mixed. About 30 .mu.l of the mixture under a N₂-atmosphere is introduced into a contact lens mold rotation. After 20 minutes of irradiation with UV light to obtain a hardened Contact lens. The lens formed is optically clear, elastic and firmly.

example 9

10 parts of allyl methacrylate monomer and 0.4 parts t-butyl peroctoate to be 90 parts of the liquid obtained in Example 3 Product added. The reaction mixture in a casting cell is introduced, which is then introduced ½ hour in an oven at 80 ° C becomes. The temperature is then raised to 100 ° C and 1 hour maintained at this value. An optically clear film is the cell harvested and maintained at 80 ° C for 15 minutes.

The above procedure is repeated using the product of Example 3 with various other monomers is converted, as given in Table I. The percentages given in this table Amounts refer to the comonomer used. In this Table are also the properties of the copolymers specified.

As Table I shows, it is an advantage of the present invention, to increase tensile strength and elongation and simultaneously a sufficient Oxygen transport capability to obtain. A problem that is results in the use of conventional silicone polymers, is the fact that these polymers are not very firm, and poor possess tensile strength and tensile strength. One of the problems that results with the use of PHEMA (Comparative) is that the contact lenses made from this material, no oxygen transport capability, as required for the human cornea is own. As mentioned, this is oxygen transport capability about 2 x 10^-6 cm³ / (sec cm² atm). Table I illustrates the Effect of the use of the comonomers according to the invention to the Strength of the polymer, ie the use of these monomers obtain an improvement in the tensile strength.

The module is preferably less than 300, when a soft contact lens to be obtained. That is, the contact lens is generally the softer, the lower the modulus.

The strain is preferably as high as possible.

Also, the oxygen transport capability is useful so high as possible and in particular higher than for the human cornea required.

Tensile strength, modulus and elongation were, as mentioned, with an Instron tester ASTM D 1708 using standard "Dog Bone" samples, the cut from 0.2 mm thick films were determined. There was no conditioning, and berug the speed 0.63 cm / min.

The oxygen transport capacity was determined as follows: Measured is the oxygen permeability of a material while it is wetted with water. This is an attempt, the conditions To reproduce in the human eye when it is a Contact lens is fitted, are present. Two stuffed with Wassser of 32 ° C Chambers by means of a flow path through which the to tested material is brought together. nitrogen purged water is pumped into both chambers until the Oxygen concentration is very low (about 0.04 ppm). Than it will be aerated water (oxygen concentration about 8 ppm) in the lower chamber introduced. In the upper chamber is a Sauerstoffmeßelektrode, the diffusion of oxygen from the lower chamber through the membrane to be tested in the upper Chamber measures introduced. In this way, the oxygen-carrying capacity of the through-flow between the two chambers covering material measured.

<imgref idrefs="35/1" />Table I

&lt;!--

<img id="35/1" wi="000" he="000" img-content="tb" />

--&gt;

example 10

58.3 g of 1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane, 41.7 g of octamethylcyclotetrasiloxane, 1 ml of concentrated H₂SO₄ and 2 g fuller's earth are placed in a pressure bottle. After 2 days equilibration, the mixture with Na₂CO₃ neutralized, filtered, diluted with hexanes, washed with water and dried, and the solvent is removed under reduced Print separated. The monomeric product of the below Formula was a colorless, odorless liquid of low Viscosity, determined in Gardner viscosity tubes.

10 g of monomeric product with 0.1 wt .-% benzoin and 0.1 wt .-% of azobis (isobutyronitrile) were mixed. The Solution of initiator and monomer is introduced into button molds and 20 minutes under irradiation with UV light in a nitrogen atmosphere and then cured for 30 minutes in air at 80 ° C. The Buttons are optically clear, colorless, hard and tough. These buttons Contact lenses are rotated. The above monomer has the following Formula:&lt;!-- <img id="36/1" wi="000" he="000" img-content="cf" /> --&gt;

example 11

7 g of the product obtained according to Example 10 and 3 g of monomer N-vinyl pyrrolidone with 0.1 wt .-% benzoin and 0.1 wt .-% mixed azobis (isobutyronitrile). The solution of initiator, monomer comonomer and is cured as described in Example 10th

The Copolymerknöpfe obtained are optically clear, colorless, hard and tough. These buttons can be easier than from which Example 10 Contact lenses rotate.

example 12

30% tetrahydrofurfuryl (TFM) are with 70% of Monomer of Example 10 in copolymerized form. The resulting Buttons are optically clear, colorless, hard and tough. These TFM- Copolymerknöpfen be rotated contact lenses.

example 13

99.3 g Octamethylcylcotetrasiloxan, 0.7 g of 1,3-bis (4-methacryloxybutyl) - tetramethyl disiloxane and 0.3 ml of trifluoromethylsulfonic acid are introduced into a pressure bottle. The bottle is sealed and 5 days shaken. The liquid monomer obtained is neutralized with sodium carbonate, diluted with hexanes and filtered. The monomer / hexane solution is washed with water and MgSO₄ dried, and the solvent is removed under reduced Print separated. Volatile materials are at 1.33 x 10^-4 bear (0.2 mm Hg) and 110 ° C is separated from the prepolymer. The Hochdruckgelpermeationschromatographie the product shows that all low molecular weight volatile material is separated. The product is a clear, colorless, odorless liquid of very high viscosity recurring with about 800&lt;!-- <img id="37/1" wi="000" he="000" img-content="cf" /> --&gt;The above monomer has the following formula:&lt;!-- <img id="37/2" wi="000" he="000" img-content="cf" /> --&gt;

example 14

are from the viscous liquid product of Example 13 by methods identical to that of Example 4 produced films. The Films are tested, the following values ​​are determined. The three-dimensionally cross-linked polymer has the following formula:&lt;!-- <img id="38/1" wi="000" he="000" img-content="cf" /> --&gt;tensile strenght<hor nb="75">34 g / mm²</hor>tensile modulus<hor nb="75">38 g / mm²</hor>strain<hor nb="75">208%</hor>

example 15

Following the procedure of Gilbert and Kantor (J. Poly. Sci., 40, S. 35-38, (1959), Transient Catalyst for the polymerization of organosiloxane) Tetramethylammoniumsilanolat is prepared. 13 g Octaphenylcyclotetrasiloxane, 92.4 g of octamethylcyclotetrasiloxane and 2.7 g of 1,3-bis (4-methacryloxybutyl) tetramethyl disiloxane are in a 500 ml four-necked round bottom flask with drying tube, N₂ inlet and mechanical stirrer introduced. The mixture is heated to 120 ° C, ½ ml of the basic catalyst is added. The temperature is increased within the next 15 minutes to 130 ° C kept at this value and 10 minutes, after which the mixture is cooled to room temperature. The viscous liquid product is diluted with hexanes with acidified water (1% HCl) and twice washed with water alone and dried over MgSO₄, and the solvent is removed under reduced pressure. The product is a siloxane monomer selected from 5 mol% phenyl-substituted silicone and 95 mol% of methyl-substituted silicone. An infrared spectrum the monomeric product shows sharp weak absorptions at 700, 1430, 1590 and 3050 cm^-1 and a shoulder on the broad Si-O-Si-absorption at 1125 cm^-1, This absorption is characteristic of phenyl and Silikonphenyl groups. The product is colorless, transparent, odorless, viscous. The viscosity 17 cm / s, measured in Gardner viscosity tubes. It is to be elastic according to the procedure of Example 4, transparent Films cast.