Hydrogel

Abstract

The invention relates to hydrogels containing water and polyethylene glycol-dimethacrylates in a polymerized form. The polymethacrylate blocks are so short that they form no proper phase. The invention further relates to methods for producing said hydrogels. The inventive hydrogels are provided with reduced haze and are used as materials for contact lenses, electrophoresis gels, membrane materials, and sound-absorbing materials.

1 - 10 . (canceled) 
     
     
         11 . A hydrogel, comprising:
 in polymerized form   A) 80-100 parts by weight of polyethylene glycol dimethacrylate of the formula (1)
   CH 2 ═CCH 3 COO—(—CH 2 —CH 2 —O—) n —COCCH 3 —CH 2    n= 7-500,  (1)
 
   B) 20-0 parts by weight of a vinyl compound B copolymerizable with (1), and   C) 100-10 000 parts by weight of water,   wherein said hydrogel comprises sulfur and a molar polyethylene glycol dimethacrylate/sulfur atoms ratio is <0.5n; and   wherein said hydrogel exhibits a haze of <10%, a light transmittance of >90% and a yellow value of <200.   
     
     
         12 . The hydrogel of  claim 11 , which has a weight water/polyethylene glycol dimethacrylate ratio in the range 1/1 to 0.5n/1. 
     
     
         13 . A contact lens material, comprising:
 the hydrogel of  claim 11 .   
     
     
         14 . An electrophoresis gel, comprising:
 the hydrogel of  claim 11 .   
     
     
         15 . A membrane material, comprising:
 the hydrogel of  claim 11 .   
     
     
         16 . A sound-deadening compound, comprising:
 the hydrogel of  claim 11 .   
     
     
         17 . A process for preparing a hydrogel of  claim 11 , said process comprising:
 polymerizing a mixture of   (A) 80-100 parts by weight of polyethylene glycol dimethacrylate of the formula (1)
   CH 2 ═CCH 3 COO—(—CH 2 —CH 2 —O—) n —COCCH 3 ═CH 2    n= 7-500,  (1)
 
   (B) 20-0 parts by weight of vinyl compounds B copolymerizable with the compound of (1), and   (C) 100-10 000 parts by weight of water in the presence of a free-radical initiator,   the polymerization being carried out at least 15° C. below a cloud point of a 10% strength solution of the polyethylene glycol dimethacrylates of formula (1) in water.   
     
     
         18 . The process of  claim 17 , wherein the molar polyethylene glycol dimethacrylate/initiator ratio is <200/1. 
     
     
         19 . The process of  claim 17 , wherein the polymerization is carried out in the presence of a mercaptan, and
 wherein the molar polyethylene glycol dimethacrylate/mercaptan ratio is <0.5n.   
     
     
         20 . The process of  claim 19 , wherein said mercaptan is a water-soluble, hydroxyl-containing mercaptan. 
     
     
         21 . A hydrogel, comprising:
 in polymerized form   A) 80-100 parts by weight of polyethylene glycol dimethacrylate of the formula (1)
   CH 2 ═CCH 3 COO—(—CH 2 —CH 2 —O—) n —COCCH 3 ═CH 2    n= 7-500,  (1)
 
   B) 20-0 parts by weight of vinyl compounds B copolymerizable with (1), and   C) 100-10 000 parts by weight of water,   wherein said hydrogel has a haze <30%, and   wherein said hydrogel contains sulfur and the molar polyethylene glycol dimethacrylate/sulfur atoms ratio is <0.5n.   
     
     
         22 . A process for preparing a hydrogel, said process comprising:
 polymerizing a mixture of   (A) 80-100 parts by weight of polyethylene glycol dimethacrylate of the formula (1)
   CH 2 ═CCH 3 COO—(—CH 2 —CH 2 —O—) n —COCCH 3 ═CH 2    n= 7-500,  (1)
 
   (B) 20-0 parts by weight of vinyl compounds B copolymerizable with the compound of (1), and   (C) 100-10 000 parts by weight of water   in the presence of an initiator,   the polymerization being carried out at least 15° C. below a cloud point of a 10% strength solution of the polyethylene glycol dimethacrylates of formula (I) in water,   wherein the polymerization is carried out in the presence of a mercaptan, and   wherein the molar polyethylene glycol dimethacrylate/mercaptan ratio is <0.5n,   wherein said hydrogel is the hydrogel of  claim 11 .   
     
     
         23 . The hydrogel of  claim 11 , wherein compound B is present and is an amide of methacrylic acid, an ester of methacrylic acid having 1-18 carbon atoms or mixtures thereof. 
     
     
         24 . The hydrogel of  claim 11 , wherein compound B is present and is methyl methacrylate or glycerol monomethacrylate. 
     
     
         25 . The hydrogel of  claim 11 , wherein compound B is present and is a methacrylic ester CH 2 ═CCH 3 CO—O—(—CH 2 —CH 2 —O—) n —H, wherein n=7-500 and corresponds to the n of the polyethylene glycol dimethacrylate. 
     
     
         26 . The hydrogel of  claim 11 , wherein compound B is present and is a glycidyl methacrylate. 
     
     
         27 . The hydrogel of  claim 21 , wherein compound B is present and is an amide of methacrylic acid, an ester of methacrylic acid having 1-18 carbon atoms or mixtures thereof. 
     
     
         28 . The hydrogel of  claim 21 , wherein compound B is present and is methyl methacrylate or glycerol monomethacrylate. 
     
     
         29 . The hydrogel of  claim 21 , wherein compound B is present and is a methacrylic ester CH 2 ═CCH 3 CO—O—(—CH 2 —CH 2 —O—) n —H, wherein n=7-500 and corresponds to the n of the polyethylene glycol dimethacrylate. 
     
     
         30 . The hydrogel of  claim 21 , wherein compound B is present and is a glycidyl methacrylate.