SU825548A1 - Method of preparing hydrogel polymeric material - Google Patents

Description

(54) METHOD FOR PRODUCING HYDROGEL POLYMER

MATERIAL

The invention relates to the production of a hydrogel poly / er material used, for example, for the manufacture of soft contact lenses. Methods are known for the preparation of hydrogel polymeric materials of various compositions used for the manufacture of soft contact lenses. Synthesis of such polymers by known methods consists in the radial copolymerization of hydrophilic monomers of acrylamide and monomethacrylic esters of glycols, monomethacrylic esters of glycols and dimethacrylic ethers of polyethylene glycol. The materials obtained in this way are transparent and have sufficient strength of 1 and -2. However, these methods are characterized by insufficient permeability: they absorb up to 38% of water. The closest in technical essence to the present invention is a method for preparing a hydrogel. polymeric material by reacting polyvinylpyrrolidone with hydroxyalkyl methacrylates in the presence of radical polymerization initiators and a crosslinking agent. By a known method, the material is obtained from a suspension of polyvinylpyrrolidone molecular weight of 37,000, taken in an amount of 20-45%, in glycols monomethacrylic ether (ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol.), Taken in an amount of 80-55% and containing 1 % methacrylic acid and 0.2% dimethacrylate corresponding to dich glycols. The polymerization is carried out at a two-stage temperature mode - 40-60 s for 4-24 hours and 90-120 C for 0.5-2 hours. The resulting billet is further processed for the purpose of hardening the material - processing with ultraviolet rays or radiation for up to 95 minutes and consumption in hydrogen peroxide up to 4 hours. The material according to the invention has a water absorption of 4080% (preferably 50-55%) and a refractive index of 1.49 in the dry state and 1.39-1.40 in the hydrated state}. . However, it should be noted that a polymer block obtained from a dispersion of reagents will necessarily have properties that are not uniform in volume: separate microblocks are formed. This is a well-known fact. The heterogeneity of the Plimaer block causes a deterioration of its properties, such as light transmission. since, with a heterogeneous structure, more favorable conditions of light scattering are created: strength — for it is always possible to concentrate internal stresses on existing microblocks in a block of material. The indicated properties are important for thin (0.1–0.5 mm) lenses manufactured by mechanical means. The purpose of the invention is to improve the mechanical and optical properties of the material while maintaining high water absorption, i.e., increasing the strength, elasticity, light transmission and refractive index while maintaining high water absorption. 15 The goal is achieved by the way in which the hydrogel polymer material is produced reacting polyvinylpyrrolidone with hydroxyalkyl methacrylates in the presence of 20 radical polymerization initiators and a crosslinking agent, polyvinylpyrrolidone uses molecular weight 10,000 wt.% in the amount of 10–40 wt.%, hydroxyalkyl methacrylate of 40–85 wt.%, and polyethylene glycol dimethacrylate of molecular weight 1500 or oligourethanedimethacrylate of molecular weight 456 in the amount of 5–20 wt.% used as crosslinking agent. 30 Oligourethanedimethacrylate It has the formula rncnc-o-cn-cc-cc-w-w 1 1 II a 2 „o. .0 where R and p 2. Polyethylene glycol dimethacrylate has the formula 40 CH - C-C-O-CHI, CHs O. The process of obtaining the material consists in carrying out radical polymerization in the presence of 0.5 wt.% Of initiators at 50-55 0 for 4-7 h, jO 78 ° C for 1-3 h and - 1 h. At the same time, a material having good optical and physicomechanical properties is formed. Example 1. 75 wt.% Hydroxygethyl methacrylate, purified by extraction from an aqueous solution with hexane, followed by salting out NaCI and distillation in vacuum, is mixed with 20 wt.% Preheated polyvinylpyrrolidone molecular weight 16,000 to 60% and 5 wt.% Polyethylene glycol dimethacrylate, molecular weight 1500. K the mixture was added 0.3 wt.% the reaction mass of benzoyl peroxide. and 0.2% dinitryl isoisobutyric acid (DAK), 65 Cm, but in this case, were used in slurry 1, and R inn was mixed in the cold until half dissolved. components. The raster is dearuated in a vacuum and the reaction vessel filled with polyethylene or fluoroplastic, F-I, is poured. Hold the vessel tightly closed, hold the reaction mass, and place it in a sallow thermostat at. At this temperature, the reaction is carried out in the course of 4 hours. Then the temperature is raised to and held for 3 hours. Over the course of the heating time, the reaction vessel is slowly cooled, the resulting billet is drained and its furnace is placed on the tall substrate. At 110 ° C pull out 1 hour. The block slowly cools down with a thermostat. The final product has the following properties: Strength at stretching, kgf / cm 555 Elongation at break,% 15 Film translucency in a dry state,% 92 Translucency, films in a swollen state,%. -96 The refractive index in the dry state is 1.52 in swelling; it is 1.425 Water absorption,% 75 Example 2. A gotot composition as in Example 1 of 10 polynylpyrrolidone molecular weight 000, 85% hydroxyethyl methacrylate 5% polyethylene glycol dimethacrylate. The action is carried out according to the mode: 55 s - 7 h 78 ° C - 1 h 110 ° C - 1 h The resulting material has the property: Strength at stretching in the dry state, kg (/ cm 520 Elongation at break,% 12 Film translucency in the dry state % 93 in the swollen state,% 97. The refractive index in the dry state 1.51 in the swollen state 1.415. Water absorption,% 64 Example 3. The material of example 1 is obtained from a composition holding 10% polyvinylpyrrolidone medical mass 16000, 70% hydro-ethyl methacrylate and 20% polyethylene dimethacrylate. The material has the properties: Strength and a tensile kp / cm 650 Elongation at break%. 20 translucent film

in the dry state,% 93 in the swollen state,% 97 The refractive index

in the dry state 1.525 in the swollen state 1.43 Water absorption,% 61 Ex. 4. The composition is prepared from 30% polyvinylpyrrolidone molecular weight 16,000, 60% hydroxyethyl methacrylate and 10% polyethylene glycol dimethacrylate. Synthesis of lead mode g

 - 5 hours

78 ° C - 2 h

110 C - 1 h

The resulting material has the following properties:

Strength at stretching in a dry state, kgtsm 490 Elongation at break,%. 12 Translucency film

in the dry state,% 91 in the swollen state,% 96 The refractive index

dry state 1.53 in the swollen STATE 1.43 Water absorption,% 84 Example 5, The material is the same as Example 1 obtained from a composition containing 40% polyvinylpyrrolidone of an unary mass of 12500, 40% hydroxyethylmethacrylate and 20% oligourethane methacrylate.

The material has the following properties: Ultimate tensile strength in dry condition, kp / cm 461 Elongation at break,% 11 Film translucency

in a dry state,% 91 in a swollen state,% 95 Water absorption,% 77 Refractive index,

in the dry state 1.53 in the swollen state 1.43

Example 6. Example 1 is repeated. Instead of 75% hydroxyethylmethacilate, 75% of hydroxypropylmethacilate is taken.

At the same time, material with properties was obtained

Strength at a stretch in a dry state, kgf / cm

505

Elongation at break,% 17 Film transparency

in dry condition,% 92

in the swollen state,% 96. The refractive index

dry1,52

in swollen condition1,42

Water absorption,% 71

. The data provided in the examples is confirmed by an act of comparative testing of synthesized materials.

15 in the dry state, the polymers obtained according to examples 1-6 are characterized by a high specific toughness for this case — 2.8-6.5 kgf x X cm / cm.

In the swollen state, the synthesized polymers are characterized by high elasticity and sufficient strength. As can be seen from the above examples. Hydrogel polymer materials,

5 obtained by the proposed method are characterized by noticeable strength (Gf 460-650 kg / cm), elasticity (elongation is 11-20%) and specific impact viscosity (2.8-6.6 kgf-cm / cm., In dry states). This greatly facilitates the process of making soft contact lenses; allows to reduce the number of defects in the manufacture; improves the quality of thin lenses (0.10, 5 mm) manufactured using the method of

chivan.

A higher refractive index of the material obtained by the proposed method, in comparison with the material obtained by the known

This method makes it possible to manufacture lenses of lesser thickness, which, for known reasons, should increase the permeability of the lenses, and therefore improve the tolerability of the lenses on the eyes.

In the swollen state of the material, the indicators obtained by the proposed method are characterized by good strength, high elasticity, translucency (96-97%). They absorb 61-84% moisture. These characteristics determine the high quality of soft contact lenses based on the proposed material.

Physical and mechanical properties of the hydrolytic material

1. PVP-10% (11000) 64 MEG - 85% TGM - 5% 2.PVP - 20% (16000) MEG - 75% TGM - 13-5% 3.PVP - 10% (16000) MEG -, 70 % TGM - 20% 4.PVP - 30% (16000) MEG - 60% TGM - 10% 5.PVP - 40% (12500), MEG - 40% Oligourendanimet. -20% 6.PVP - 20% (16000) 71 92 96 PGM - 75% TGM - 5% 7.PVP - 20% (37000) 51-53 90 95 MEG - 80% DMEG - 0.2% 8.PVP - 35% (37000) 55-59 88 93 MEG - 65% DMEG - 0.2%

9. PVP - 20%

(16000) 47

MEG - 80%

93. 97 1.51 1.415 520 12 92 96 93 97 91 96 91 96

Known material

Without crosslinking agent

92 89 1.50 1.8585 6.6 1.52 1.435555515 1.5525 1.43 650 20 1.53 1.43 490 / .12 1.53 1.43 461 11 1.52 1.42. 505 17 1,490 1,39 410 9 1,492 1.40 350 6

Claims (3)

1. Patent Czechoslovakia No. 133433, cl. 39 a 11/00, published 1968. 2. US Patent 3,505,942, 0 cl. 98-115, published. 1970. 3. US patent 3822196, cl. 204-159.16, published. 1974 (prototype).