RU2334770C1 - Polymer composition for soft contact lenses of prolonged wearing and method of production thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: inventions refer to medical materials and can be used for polymer materials for soft contact lenses (SCL) of prolonged wearing. Engineering problem is development of polymer composition in the form of interpenetrating grids for SCL of prolonged wearing, possessing oxygen barrier property, hydrophilic properties, mechanical strength and optical transparency in both hydrated and dehydrated state, as well as development of simplified, efficient production method not requiring large quantity of highly toxic organic solvents. Offered are polymer composition representing bi-phase silicone-hydrogel material in the form of sequential interpenetrating grids consisting of cross-linked polysiloxane that is reaction product of vinyl-containing and hydro-containing oligosiloxane, and hydrophilic polymer that is cross-linked polyvinyl alcohol, and production method thereof including synthesis of cross-linked polysiloxane; polysiloxane saturation with monomeric mixture containing vinylacetate, cross-linking monomer and radical polymerisation initiator; copolymerisation of vinylacetate and cross-linking monomer, alcoholysis of cross-linked polyvinylacetate and production of silicone-hydrogel polysiloxane - polyvinyl alcohol.

EFFECT: production of polymer composition in the form of interpenetrating grids for SCL of prolonged wearing, possessing oxygen barrier property, hydrophilic properties, mechanical strength and optical transparency, and development of simplified, efficient production method not requiring large quantity of highly toxic organic solvents.

6 cl, 1 tbl, 9 ex

Description

The group of inventions relates to the field of medicine, in particular ophthalmology, and can be used to obtain polymer materials for soft contact lenses (MKL) extended wear.

Soft contact lenses of prolonged wear include such MKL that the patient can use continuously, that is, without taking off at night, for a long time (up to 30 days).

The materials used for the manufacture of MKL of this type have a number of special requirements. The specificity of the requirements is that, along with optical transparency, hydrophilic properties (water and ion permeability, wettability with tear fluid) and mechanical strength, they must have high oxygen permeability to prevent corneal hypoxia during night sleep. For adequate corneal oxygen supply, MKL eyes of extended wear should have oxygen permeability with a 0.1 mm lens thickness of at least 125 barrers [D.V. Harvitt, J.A. Bonnano. Optometry and Vision Science. 1998 .-- N12. - p. 189].

It is known that siloxane-containing polymers possess very high oxygen permeability [Encyclopedia of Polymers. T.1. Ed. "Soviet Encyclopedia". M .: 1972. P.589]. The main disadvantage of such materials is their hydrophobicity. Therefore, MKL made from such materials, due to the limited mobility on the cornea of the eye and the appearance on the surface of deposits of proteins and lipids contained in the lacrimal fluid, create discomfort for the patient with prolonged wear.

Numerous methods are known for hydrophilizing the surface of polysiloxanes and contact lenses based on them with chemical [US 5364918, 1994.11.15; US 5525691, 1996.06.11; US 5219965, 1993.06.15 ;. US 5135297.1992.08.04] or physical (plasma treatment) [US 4055378, 1977.10.25; US 4122942; 1978.10.31; US 4214014, 1980.06.22] by methods. These methods improve the wettability of polysiloxane, but due to the low water content they cannot provide sufficient water and ion permeability of the material.

To increase the water content of siloxane-containing polymers, hydrophilic monomer units are introduced into their composition. It is known to obtain copolymers for MCLs containing units of methacrylic derivatives of siloxanes, units of hydrophilic monomers, such as 2-hydroxyethyl methacrylate, dimethyl acrylamide, N-vinylpyrrolidone and a small number of units of crosslinking (co) monomers (divinylbenzene, ethylene glycol dimethacrylate [US 4139 et al. 13]. MKL from copolymers is obtained according to the traditional technology of mechanical processing of polymer blanks. Depending on the content of hydrophilic monomer units in the MKL copolymer, they are capable of containing from 16-44 wt.% Water, that is, they have quite satisfactory hydrophilic properties. However, the oxygen permeability of MKL with a thickness of 0.11-0.15 mm does not exceed 21 barrers, which does not allow their use in continuous continuous wear.

Currently, the most promising polymeric materials for extended-wear MKL are silicone hydrogels - materials with a microheterogeneous structure, including a polysiloxane phase, which provides high oxygen permeability, and a hydrophilic polymer phase, which gives the MKL hydrophilic properties. Known methods for producing such materials and the manufacture of them MKL [US 5070215, 1991.12.03; US 6367929, 2002.04.09; US 5352714, 1994.10.04; US 5260000, 1993.11.09; Y.-C.Lai, P.L. Valint Jr. Control of properties in silicone hydrogels by using a pair of hydrophylic monomers. // J. Appl. Polym. Sci. 1998 .-- V.61. - No. 12. p.2051-2058; US 5321108, 1994.06.14]. Most methods for producing silicone hydrogels are based on the synthesis of crosslinked block grafted copolymers. The method of obtaining includes several stages. First get the macromer, which is a polysiloxane with terminal polymerization-capable functional groups, having, for example, the structure [US 5070215, 1991.12.03]

where x = 25.

Known polysiloxanes with polymerization functional groups of a different type [US 6367929, 2002.04.09]

where X = —O— or —NH—, R = —H or —CH ₃ .

The number of siloxane units (X) also varies within a very wide range (from 10 to 500) [US 6367929, 2002.04.09].

In the second stage of the process, a polymerization mixture is prepared, which includes, as a rule, the following components:

- siloxane macromer, monofunctional siloxane monomer, such as methacryloxypropyltris (trimethylsiloxy) silane, pentamethyldisiloxane ethyl acetate and others [US Pat. 5352714, 1994.10.04], a hydrophilic monomer (2-hydroxyethyl methacrylate, acrylamide, methacrylamide, N, N-dimethyl acrylamide, N-vinyl pyrrolidone, etc.) [US 5260000, 1993.11.09] or a mixture of hydrophilic monomers [Y.-C.Lai , PLValint Jr. Control of properties in silicone hydrogels by using a pair of hydrophylic monomers. // J. Appl. Polym. Sci. 1998 .-- V.61. - No. 12. - p.2051-2058];

- polymerization initiator, providing the formation of free radicals under the influence of light or heat;

- a diluent (solvent) for combining the polymerizable components.

The specified reaction mixture is placed in a closed, two-part form and polymerization is carried out. After completion of the polymerization, the form is opened and the resulting material is subjected to extraction, usually with ethanol or propanol, to remove unreacted substances. Then the material is washed with water. The material obtained by this technology [US 5321108, 1994.06.14] has a high oxygen permeability of 52-186 barrels. The water content in the material depending on the composition is in the range of 17-52 wt.%.

A disadvantage of materials of this type is the poor wettability of their surface, which forces one more step to be included in the technological process - chemical [WO 0134312, 2001.05.17] or plasma-chemical [US 6348507, 2002.02.19]. Thus, the complex technology and the use of expensive reagents in the synthesis of macromers and during polymerization determine the high cost of these silicone-hydrogel MKL.

Known silicone hydrogel and a method for its preparation according to a significantly simpler technology, carried out using the principle of simultaneous interpenetrating networks [DE 2518904, 1975.11.13]. In this case, a polysiloxane network is formed by the interaction of vinyl- and hydride-containing siloxane oligomers in the presence of a catalyst (hydrochloric acid platinum), and a hydrophilic polymer network is obtained by polymerization of hydrophilic monomers, such as 2-hydroxyethyl methacrylate or N-vinylpyrrolidone in the presence of crosslinking (e.g., ethylene monolate) and initiators of radical polymerization. To combine the components, solvents (e.g., chloroform) are added to the composition. Both processes are carried out simultaneously, which leads to the appearance of simultaneous interpenetrating grids. Thus obtained material is distinguished by transparency and elasticity. The oxygen permeability of the specified prototype material is at a high level (150-200 barrels), since the composition contains a large amount of polysiloxane component (80-95 wt.%). The disadvantage of silicone hydrogel materials obtained by this method are low hydrophilic properties. The water content in the material is in the range of 3-12 wt.%. Such a low water content cannot provide comfortable long-term wearing of MKL. The low water content in the MCL is due to the difficulty of incorporating the required amount of hydrophilic component into the material.

The closest in technical essence to the claimed invention are silicone-hydrogel polymer composition and method for its preparation [RF 2269552, C08L 83/07, C08L 39/06, G02C 7/04, 2006.10.02], selected as prototypes.

Prototype material - a polymer composition for extended-wear MCL is a biphasic silicone hydrogel in the form of successive interpenetrating networks consisting of crosslinked polysiloxane and a hydrophilic polymer, while crosslinked polysiloxane is the product of the interaction of a vinyl-containing component, including a mixture of oligosiloxane

where R = -CH ₃ or -CH ₂ CH ₂ CF ₃ , n = 44-46, m = 4-6, p = 0-2,

and polysiloxane

with a molecular weight of 400,000-900,000 with a molar ratio q / r of from 99.9 / 0.1 to 99.5 / 0.5, and a hydride component, which is an oligomer

where s = 10-100,

and the hydrophilic polymer is a crosslinked (co) polymer of N-vinyl pyrrolidone, 2-hydroxyethyl methacrylate, acrylamide and dimethyl acrylamide.

The method of obtaining this polymer composition is based on the synthesis of sequential interpenetrating networks and includes the steps of:

1) obtaining a polysiloxane network by the interaction of vinyl-containing and hydride-containing siloxane components;

2) saturation of the crosslinked polysiloxane with a solution of hydrophilic monomers and crosslinking monomers in an aromatic or aliphatic chlorinated hydrocarbon;

3) polymerization of monomers under the influence of UV radiation in the presence of a photoinitiator.

The prototype material is characterized by a high level of properties: oxygen permeability of 125-150 barrels, water content of 17-30%, contact angle of wetting of 45-54 °, light transmission coefficient of 82-92%, tensile strength of 0.8-1.2 MPa. The method of obtaining the prototype material is characterized by simple technology and does not require the use of surface treatment of the material to give it good wettability, special synthesis of organosilicon macromers and the use of expensive components.

The disadvantage of the prototype material - silicone hydrogel synthesized according to the described technology, is that it is optically transparent only in the hydrated state. With the loss of moisture, its transparency decreases, and with complete dehydration, it becomes completely opaque. The decrease in optical transparency with a decrease in the water content in the material with a decrease in the relative humidity of the air or with a deterioration in the release of tear fluid makes it difficult to use MKL made of such silicone hydrogel.

The optical transparency of this biphasic silicone hydrogel in the hydrated state is due to the fact that polysiloxane and the hydrophilic polymer at equilibrium saturation with water have the same refractive indices. With moisture loss, the refractive index of the hydrophilic polymer increases and the transparency of the silicone hydrogel deteriorates. This is because the structural elements of the biphasic material have a size comparable to the wavelength of visible radiation, which leads to intense light scattering.

The disadvantage of the method of obtaining the material of the prototype is the use in the synthesis of very toxic solvents such as toluene or chloroform. Another disadvantage is associated with the technology of obtaining a hydrophilic polymer network and the final product, which is an interpenetrating network. Crosslinked polysiloxane is placed in a reaction mixture containing a solvent, hydrophilic monomers, a crosslinking agent and a photoinitiator, and kept in this mixture until equilibrium swelling, and then the reaction mixture is photopolymerized. As a result of photopolymerization, a second network is formed, which is embedded in cross-linked polysiloxane, which leads to the combination of two polymer phases forming interpenetrating networks. After photopolymerization is completed, the resulting polymer composition is a polymer body embedded in a hydrophilic polymer gel. The polymer composition is extracted from the gel with its additional swelling in an aromatic or chlorinated hydrocarbon or in aliphatic alcohol. Thus, there is an unproductive expenditure of hydrophilic monomers and solvents.

The aim of the invention is the creation of a polymer composition in the form of interpenetrating nets for MKL extended wear, with oxygen permeability, hydrophilic properties, mechanical strength and optical transparency in both hydrated and dehydrated state, and simplified, economical, free from the use of a large number of highly toxic organic solvents way to get it.

This goal is achieved due to the fact that the polymer composition for extended-wear MKL is a biphasic silicone-hydrogel material in the form of successive interpenetrating polymer networks, including crosslinked polysiloxane, which is the product of the interaction of vinyl-containing oligosiloxane

where n = 44-46, m = 4-6, p = 0-2,

and a hydride oligosiloxane representing an oligomer

where s = 10-100, R = -CH ₃ or -CH ₂ CH ₂ CF ₃ ,

and a crosslinked hydrophilic polymer, characterized in that the crosslinked hydrophilic polymer is a crosslinked polyvinyl alcohol containing units of a crosslinking monomer selected from the group of diallyl phthalate, triallyl cyanurate or triallyl isocyanurate, in an amount of 0.5-5.0 wt.%, and the weight ratio is crosslinked ranges from 76.0: 24.0 to 94.0: 6.0.

A method of obtaining the inventive polymer composition for MKL extended wear, comprising the synthesis of sequential interpenetrating networks, including operations:

obtaining cross-linked polysiloxane by the interaction of vinyl-containing and hydride-containing oligosiloxanes in a closed polymer form, consisting of two parts, at 15-50 ° C for 2-48 hours in the presence of a solvent and using a catalyst taken in an amount of 0.91-5.45% by weight of oligosiloxanes and representing a complex of platinum hydrochloric acid with vinyl-containing oligosiloxane when the content of platinum in the complex is in the amount of (2-10) · 10 ^-5 g-at / cm ³ ;

saturation of the crosslinked polysiloxane with components that form the crosslinked hydrophilic polymer after the polymer form is opened and the solvent is removed by evaporation at room temperature by swelling the polysiloxane in a reaction mixture previously blown with an inert gas containing, in addition to monomers, a radical polymerization initiator;

copolymerization of monomers forming a crosslinked hydrophilic polymer;

characterized in that when receiving a cross-linked polysiloxane, aliphatic hydrocarbons of the composition C ₅ H ₁₂ -C ₈ H ₁₈ in an amount of 30-100% by weight of oligosiloxanes are used as a solvent, and the formation of a cross-linked hydrophilic polymer and the formation of interpenetrating polymer networks are carried out in two stages: 1 ) copolymerization of vinyl acetate and a crosslinking monomer in the absence of a solvent; 2) alcoholysis of crosslinked polyvinyl acetate and the formation of crosslinked polyvinyl alcohol.

The essence of the invention lies in the fact that the proposed polymer composition includes a crosslinked polysiloxane and a crosslinked polyvinyl alcohol at wt. the ratio of 76:24 to 94: 6, while the cross-linked polysiloxane is the product of the interaction of vinyl-containing and hydride-containing components at wt. a ratio of 97.08: 2.92 to 90.90: 9.10, and the crosslinked polyvinyl alcohol contains units of a crosslinking monomer in an amount of 0.5-5.0 wt.%. As the crosslinking monomer, diallyl phthalate, triallyl cyanurate or triallyl isocyanurate are used. During the first stage of the production of interpenetrating nets — the synthesis of cross-linked polysiloxane, aliphatic hydrocarbons are used as solvent, the toxicity of which is much lower in comparison with the toxicity of the solvents used in the prototype method [RF 2269552, 2006.10.02]. In addition, small amounts of solvent are used in the synthesis, since unlike the prototype, high molecular weight polysiloxane is not introduced into the vinyl-containing oligosiloxane, which makes it possible to obtain a low-viscosity solution that can easily be poured into the polymeric forms forming the cross-linked polysiloxane in the form of thin films or contact lenses.

Thus, a cross-linked polysiloxane is obtained in the form of a film with a thickness of 50-250 μm or in the form of a contact lens. After completion of the reaction, the form is opened and the solvent is removed by evaporation at room temperature.

The crosslinked polysiloxane thus obtained, in the form of a film or lens, is again placed in a polymeric form into which the required amount of the reaction mixture of the following composition is loaded (parts by weight):

- vinyl acetate - 95.0-99.5;

- crosslinking monomer - 0.5-5.0;

- initiator of radical polymerization - 0.5-5.0.

The amount of the reaction mixture is chosen so as to obtain a weight ratio of crosslinked polysiloxane / monomers ranging from 88:12 to 55:45. At the indicated ratios, the cross-linked polysiloxane after holding for 1.5-2 hours absorbs the entire amount of the monomer mixture. The copolymerization of vinyl acetate is carried out in the presence of 0.5-1.5% by weight of monomers of dinitrile azoisobutyric acid or benzoyl peroxide at 50-70 ° C for 2-3 hours or at room temperature under the influence of UV radiation with an energy exposure of 400-700 J / cm ² the presence of 0.5-5.0 wt.% photoinitiator for 10-20 minutes The photoinitiator is selected from the group of compounds: benzoin methyl or isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone. Photopolymerization is carried out in a form made of UV-permeable material. As such, for example, a copolymer of tetrafluoroethylene and hexafluoropropylene is used. The copolymerization is carried out until the complete conversion of the monomers. Thus, the copolymerization product is an interpenetrating network of polysiloxane - polyvinyl acetate and does not contain macrophase crosslinked polyvinyl acetate.

The resulting product is removed from the polymer form, placed in aliphatic alcohol containing an alcoholysis catalyst in an amount of 0.5-3.0% by weight of alcohol, and the alcoholysis reaction is carried out at 30-50 ° C. for 1.0-5.0 hours. Methanol and ethanol are used as the aliphatic alcohol. or isopropanol, and the catalyst for alcoholysis is alkali metal hydroxides. After completion of the alcoholysis reaction, the resulting product is washed many times with water. The result is a polymer composition, which is a silicone-hydrogel polysiloxane - polyvinyl alcohol. Under these conditions, the complete conversion of polyvinyl acetate to polyvinyl alcohol occurs. This is indicated by the absence in the IR spectrum of the polymer composition of a band in the region of 1740 cm ^-1 responsible for the absorption by acetate groups. The synthesized product is optically transparent in both hydrated and dried state, which indicates the fine structure of the obtained biphasic material, the structural elements of which are smaller than the wavelength of visible radiation.

The invention is illustrated by the following examples.

Example 1

Synthesis of crosslinked polysiloxane. Prepare a reaction mixture having the following composition (wt. Parts):

vinyl oligosiloxane with parameters: p = 0, n = 44, m = 4, R = -CH ₃ 90.9 hydride-containing oligosiloxane (R = -CH ₃ , s = 10) 9.1 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 2 · 10 ^-5 g-at / cm ³ 2.27 hexane 100.0

The reaction mixture is poured into polymer molds made from a copolymer of tetrafluoroethylene and hexafluoropropylene (F4-MB) and assembled in two parts. The molds are closed and cured for 24 hours at room temperature. After curing, the forms are opened, hexane is evaporated at room temperature and crosslinked polysiloxane samples are obtained in the form of films with a thickness of 250 μm. Films are cut into fragments of size 30 × 50 mm.

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 98.5 diallyl phthalate (DAP) 1.5 2,2-dimethoxy-2-phenylacetophenone (DMF) 2.5

The polymer form is collected from the F4-MB copolymer, polysiloxane is placed in it in the form of a film 30 × 50 × 0.25 mm in size, weighing 0.36 g, and 0.20 g of the monomer mixture previously purged with nitrogen is poured into it. The form is closed and the polysiloxane is saturated with monomers at room temperature for 2 hours. During this time, the polysiloxane completely absorbs the entire loaded amount of the monomer mixture.

The copolymerization is carried out under the influence of UV radiation using a DRK-120 mercury lamp at an energy exposure of 700 J / cm ² for 10 minutes.

Alcoholysis of crosslinked polyvinyl acetate. After copolymerization, a cross-linked polysiloxane-crosslinked polyvinyl acetate material is placed in a 3% solution of sodium hydroxide in methanol and heated at 30 ° C for 2 hours. Then, the sample is removed from the methanol solution of alkali and placed in a vessel with distilled water to remove methanol, alkali and low molecular weight products of alcoholysis, periodically updating the wash water. Washing is continued for 15 hours. After washing, the samples are placed in an isotonic sodium chloride solution. The resulting product is a silicone hydrogel polysiloxane - polyvinyl alcohol.

To assess the completeness of alcoholysis, the samples are dried and IR spectra are obtained on a Shimadzu Fourier spectrometer (model FTIR-8300).

The absence of an absorption band in the region of 1740 cm ⁻¹ indicates the complete conversion of polyvinyl acetate to polyvinyl alcohol.

The properties of the obtained polymer composition are shown in the table.

Example 2

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 90.9 hydride-containing oligosiloxane (R = -CH ₃ , s = 25) 9.1 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 1 · 10 ^-4 g-at / cm ³ 5.45 heptane 30.0

The synthesis is carried out at 50 ° C for 2 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 95.0 DAF 5.0 benzoin isobutyl ether 5.0

A polysiloxane film weighing 0.42 g is placed in the mold and 0.14 g of the monomer mixture is added. Saturation is carried out at room temperature for 2 hours.

The copolymerization is carried out under the influence of UV radiation at an energy exposure of 400 J / cm ² for 20 minutes

The alcoholysis of crosslinked polyvinyl acetate is carried out with a 0.5% ethanol solution of potassium hydroxide at 50 ° C for 1 h.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 . The properties of the obtained polymer composition are shown in the table.

Example 3

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 93.75 hydride-containing oligosiloxane (R = -CH ₃ , s = 25) 6.25 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 4 · 10 ^-5 g-at / cm ³ 3.25 hexane 50.0

The synthesis is carried out at room temperature for 24 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 99.5 triallyl isocyanurate 0.5 DMF 0.5

A film of polysiloxane weighing 0.36 g is placed in the mold and 0.24 g of the monomer mixture is added. Saturation is carried out at room temperature for 1.5 hours.

The copolymerization is carried out under the influence of UV radiation at an energy exposure of 700 J / cm ² for 20 minutes

Alcoholysis of crosslinked polyvinyl acetate is carried out with a 1% methanol solution of sodium hydroxide at 30 ° C for 1 h.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 .

The properties of the obtained polymer composition are shown in the table.

Example 4

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 94.75 hydride oligosiloxane (R = CF ₃ CH ₂ CH ₂ -, s = 25) 5.25 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 2 · 10 ^-5 g-at / cm ³ 3.25 hexane 100.0

The synthesis is carried out at 20 ° C for 48 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 98.5 DAF 1.5 DMF 2.5

A polysiloxane film weighing 0.41 g is placed in the mold and 0.35 g of the monomer mixture is added. Saturation is carried out at room temperature for 2 hours.

The copolymerization is carried out under the influence of UV radiation at an energy exposure of 500 J / cm ² for 20 minutes

Alcoholysis of crosslinked polyvinyl acetate is carried out with a 1% methanol solution of sodium hydroxide at 35 ° C for 2 hours.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 .

The properties of the obtained polymer composition are shown in the table.

Example 5

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 96.15 hydride-containing oligosiloxane (R = -CH ₃ , s = 25) 3.85 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 4 · 10 ^-5 g-at / cm ³ 3.25 hexane 100.0

The synthesis is carried out at 15 ° C for 24 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 98.5 DAF 1.5 DMF 2.5

A 0.45 g polysiloxane film is placed in the mold and 0.37 g of the monomer mixture is added. Saturation is carried out at room temperature for 2 hours.

The copolymerization is carried out under the influence of UV radiation at an energy exposure of 500 J / cm ² for 20 minutes

Alcoholysis of crosslinked polyvinyl acetate is carried out with a 1% methanol solution of sodium hydroxide at 35 ° C for 2 hours.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 .

The properties of the obtained polymer composition are shown in the table.

Example 6

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 90.9 hydride-containing oligosiloxane (R = -CH ₃ , s = 25) 9.1 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 4 · 10 ^-5 g-at / cm ³ 3.25 hexane 50.0

The synthesis is carried out at 20 ° C for 24 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 98.5 DAF 1.5 benzoyl peroxide 1.5

A 0.44 g polysiloxane film is placed in the mold and 0.06 g of the monomer mixture is added. Saturation is carried out at room temperature for 2 hours.

The copolymerization is carried out at 70 ° C for 2 hours

Alcoholysis of crosslinked polyvinyl acetate is carried out with a 1% methanol solution of sodium hydroxide at 35 ° C for 2 hours.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 .

The properties of the obtained polymer composition are shown in the table.

Example 7

Obtaining a polymer composition is carried out as in example 1, but with the following differences.

The synthesis of cross-linked polysiloxane is carried out according to the recipe:

vinyl oligosiloxane with parameters: p = 1, n = 46, m = 4, R = CF ₃ CH ₂ CH ₂ - 90.9 hydride-containing oligosiloxane (R = -CH ₃ , s = 25) 9.1 the catalyst is a complex of platinum hydrochloric acid with vinyl oligosiloxane (p = 1, n = 44, m = 4, R = -CH ₃ ) with a platinum content of 4 · 10 ^-5 g-at / cm ³ 3.25 hexane 50.0

The synthesis is carried out at 20 ° C for 24 hours

Saturation of crosslinked polysiloxane with a monomer mixture. Prepare a monomer mixture of the following composition:

vinyl acetate 98.5 DAF 1.5 dinitrile azoisobutyric acid 0.5

A 0.46 g polysiloxane film is placed in the mold and 0.29 g of the monomer mixture is added. Saturation is carried out at room temperature for 2 hours.

The copolymerization is carried out at 50 ° C for 3 hours

The alcoholysis of crosslinked polyvinyl acetate is carried out with a 1% methanol solution of sodium hydroxide at 35 ° C for 2 hours.

The infrared spectrum of the dried product recorded the absence of absorption in the region of 1740 cm ^-1 .

The properties of the obtained polymer composition are shown in the table.

Example 8

The preparation of the polymer composition is carried out as in Example 7, but the stages of the synthesis of cross-linked polysiloxane and copolymerization of vinyl acetate and DAP are carried out in a polymer form consisting of two parts (matrix and punch) and having a lens configuration (matrix diameter and radius 13.5 and 7.9 mm, respectively). As a result, a lens is formed with the following parameters in a hydrated state: diameter - 14.5 mm, outer radius - 8.5 mm

Example 9

The study of the properties of the inventive silicone-hydrogel polymer composition.

After washing, the inventive silicone-hydrogel polymer composition is placed in an isotonic sodium chloride solution and tested in a hydrated state.

During the test, the following characteristics are determined:

- chemical composition (polysiloxane / polyvinyl alcohol ratio);

- water content in the material;

- wetting angle;

- oxygen permeability;

- light transmittance in hydrated and dry state;

- mechanical properties.

These characteristics are determined using the following methods.

Chemical composition

The mass ratio of polysiloxane / crosslinked polyvinyl alcohol is determined by the change in mass of polysiloxane after the procedure for producing interpenetrating nets. To do this, first measure the mass of polysiloxane, and then the mass of the final material (m) after copolymerization, alcoholysis and drying of the sample.

The content in the material of crosslinked polyvinyl alcohol (C _p ) and polysiloxane (C _c ) is calculated by the formulas

C _c = 100-C _p (wt.%),

where m _c is the mass of polysiloxane;

m is the mass of the final material after drying.

The water content in the films aged in an isotonic sodium chloride solution for 24 hours is determined as follows:

wet MKL or film is weighed, then they are dried in a vacuum oven at room temperature to constant weight. Having determined the mass of dry MKL or film, their moisture content (C _w ) is determined by the formula

where w ₁ is the mass of dry MKL or film;

w ₂ - the mass of wet MKL or film.

The light transmission coefficient is measured on a universal objective FOU UHL 42 photometer. The methodology adopted for measurements on small samples is used [Universal objective FOU photometer. // Technical description for use. / Zagorsk Optical and Mechanical Plant. 1989, p.31].

The study of mechanical properties is carried out using a universal installation for mechanical testing UTS 10 (Germany). The stretching speed is 10 mm / min. Tests are carried out at a temperature of 23 ± 1 ° C.

The contact angle (C _A ) of the surface of the MCL is determined in an isotonic solution of sodium chloride by the bubble method [Aivazov B.V. Workshop on the chemistry of surface phenomena and adsorption. - M .: Publishing house "Higher School", 1973. - S.24-26].

Oxygen permeability is calculated from the data on the content of water in the polymer composition using the well-known water oxygen content for silicone hydrogels [Tighe B.J. Soft lens materials. // In: Contact lens practice. Ed. N.Efron. Oxford Butterworth Heinemann. 2002. P.81].

The results of studies of the properties of the inventive polymer composition obtained in accordance with examples 1-7 are presented in the table.

From the data presented in the table it can be seen that, due to the biphasic nature of the proposed material, it combines high oxygen permeability of 110-170 barrels and hydrophilic properties (water content at the level of 17-30 wt.%). The wettability of the composition, characterized by the value of the contact angle, is 45-55 °. High mechanical properties of the claimed silicone-hydrogel composition in a hydrated state — tensile strength at a level of 0.6-1.2 MPa and elongation at break at a level of 90-110% —use it to be used for the manufacture of MKL with a thickness of less than 0, 1 mm. The polymer composition is characterized by high optical transparency in both hydrated and dry state.

The claimed inventions satisfy the “novelty” criterion, since for the first time a polymer composition is proposed as a material for MKL extended wear, which is a biphasic silicone-hydrogel material in the form of successive interpenetrating nets, in which polyvinyl alcohol is used as the hydrogel component, and a method for its preparation.

The claimed invention satisfies the criterion of "inventive step", since there is no information in known and accessible sources of information from which it would be obvious that the method of successive interpenetrating nets could be implemented to obtain a silicone hydrogel combining high oxygen permeability, water content, wettability, and optical transparency as in hydrated and dehydrated.

Compliance with the criterion of "suitability for industrial use" is proved by the results of the above laboratory studies, from which it is clear that silicone hydrogel is a promising material for MKL extended wear, and its production method is simple and economical, does not require the use of highly toxic substances and expensive methods of surface treatment of the material , based on the use of relatively inexpensive and commercially available in the Russian Federation raw materials. The proposed polymer composition for physico-chemical properties is at the level of materials produced by foreign companies.

The results of the study of the properties of the inventive silicone-hydrogel polymer composition The investigated parameter The properties of the inventive silicone hydrogel polymer composition obtained according to example one 2 3 four 5 6 7 Mas. silicone / polyvinyl alcohol ratio 80/20 84/16 77/23 76/24 76/24 94/6 77/23 The water content, wt.% 19 eighteen 21 25 27 17 twenty Wetting angle, degrees fifty 55 fifty 45 45 55 fifty Light transmittance at a sample thickness of 250 μm,% Hydrated 92 90 93 94 94 90 91 In dry condition 92 90 92 93 94 90 90 Oxygen permeability, barrer 150 160 135 110 one hundred 170 140 Tensile Strength, MPa 1.3 1.3 1.2 1.0 1.01 1.5 1.2 Elongation at break,% 95 90 85 110 one hundred 80 90

Claims (6)

1. The polymer composition for soft contact lenses extended wear, which is a biphasic silicone-hydrogel material in the form of sequential interpenetrating polymer networks, including cross-linked polysiloxane, which is the product of the interaction of vinyl-containing oligosiloxane

where n = 44-46, m = 4-6, p = 0-2, and hydride oligosiloxane

where s = 10-100, R = -CH ₃ or -CH ₂ CH ₂ CF ₃ , at a mass ratio of oligomers from 97.08: 2.92 to 90.90: 9.10 and a crosslinked hydrophilic polymer, characterized in that the crosslinked hydrophilic polymer is a crosslinked polyvinyl alcohol containing units of a crosslinking monomer selected from the diallyl phthalate, triallyl cyanurate or triallyl groups in an amount of 0.5-5.0 wt.%, and the mass ratio of crosslinked polysiloxane / crosslinked polyvinyl alcohol is in the range from 76.0: 24.0 to 94.0: 6.0. 2. A method of obtaining a polymer composition for soft contact lenses extended wear according to claim 1, comprising a synthesis of sequential interpenetrating networks, including the operation: obtaining cross-linked polysiloxane by the interaction of vinyl-containing and hydride-containing oligosiloxanes in a closed two-part polymer form at 15-50 ° C for 2-48 hours in the presence of a solvent and using a catalyst taken in an amount of 0.91-5.45% of the mass of oligosiloxanes and representing a complex of platinum hydrochloric acid with vinyl-containing oligosiloxane when the content of platinum in the complex is in the amount of (2-10) · 10 ^-5 g-at / cm ³ ; saturation of the crosslinked polysiloxane with components that form the crosslinked hydrophilic polymer after the polymer form is opened and the solvent is removed by evaporation at room temperature by swelling the crosslinked polysiloxane in a reaction mixture previously blown with an inert gas containing, in addition to monomers, a radical polymerization initiator; copolymerization of monomers forming a crosslinked hydrophilic polymer, characterized in that when receiving a cross-linked polysiloxane, aliphatic hydrocarbons of the composition C ₅ H ₁₂ -C ₈ H ₁₈ are used as a solvent, and the formation of a cross-linked hydrophilic polymer and the formation of interpenetrating polymer networks are carried out in two stages: 1) copolymerization of vinyl acetate and a crosslinking monomer in the absence of a solvent; 2) alcoholysis of crosslinked polyvinyl acetate and the formation of crosslinked polyvinyl alcohol. 3. The method according to claim 2, characterized in that the saturation of the crosslinked polysiloxane with a monomer mixture containing vinyl acetate, a crosslinking monomer and a radical polymerization initiator, and the subsequent copolymerization of vinyl acetate and a crosslinking monomer is carried out in a closed two-part polymer form, with a weight ratio of crosslinked polysiloxane / monomers from 88:12 to 55:45. 4. The method according to PP.2 and 3, characterized in that the copolymerization of vinyl acetate and a crosslinking monomer is carried out in the presence of dinitrile azoisobutyric acid or benzoyl peroxide, taken in an amount of 0.5-1.5% by weight of monomers, at 50-70 ° C . 5. The method according to PP.2 and 3, characterized in that the copolymerization of vinyl acetate and a crosslinking monomer is carried out under the influence of UV radiation at an energy exposure of 400-700 J / cm ² in the presence of a photoinitiator selected from the group of 2,2-dimethoxy-2- phenylacetophenone, methyl or isobutyl ether of benzoin, taken in an amount of 0.5-5.0% by weight of the monomers, in a closed polymer form made of a UV-permeable polymer. 6. The method according to PP.2 and 3, characterized in that the alcoholysis of the polymer composition containing crosslinked polyvinyl acetate is carried out in an aliphatic alcohol selected from the group of methanol, ethanol, isopropanol, using an alkali metal hydroxide of 0.5-3% by weight as a catalyst aliphatic alcohol, at 30-50 ° C for 1-5 hours