Superabsorbent polymer having a capacity increase

Abstract

The present invention relates to a particulate superabsorbent polymer comprising a monomer and an internal crosslinker agent wherein the particulate superabsorbent polymer has a Centrifuge Retention Capacity Increase of 2 g/g or more as set forth herein in the Centrifuge Retention Capacity Increase Test. The present invention further relates to a superabsorbent polymer comprising an internal crosslinker agent comprising a silane compound comprising at least one vinyl group or one allyl group attached to a silicon atom, and at least one Si—O bond. The present invention further relates to an absorbent article that includes such particulate superabsorbent polymers.

1 - 56 . (canceled) 
     
     
         57 . A superabsorbent polymer comprising a polymerized monomer selected from an ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid anhydride, salts or derivatives thereof, and an internal crosslinker agent comprising a silane compound comprising at least one vinyl group or allyl group and at least one Si—O bond, wherein the vinyl group or allyl group is directly attached to a silicon atom, wherein the superabsorbent polymer composition is a particulate superabsorbent composition and having a Vortex time of from about 20 to about 180 sec. 
     
     
         58 . The particulate superabsorbent polymer of  claim 57 , wherein the particulate superabsorbent polymer has a Centrifuge Retention Capacity of from about 25 g/g to about 55 g/g as set forth herein in the Centrifuge Retention Capacity Test and having a Vortex time of from about 20 to about 60 sec. 
     
     
         59 . The particulate superabsorbent polymer of  claim 57 , wherein the particulate superabsorbent polymer has a Absorbency Under Load at 0.9 psi of about 15 g/g to about 25 g/g as set forth herein in the Absorbency Under Load at 0.9 psi Test. 
     
     
         60 . The particulate superabsorbent polymer of  claim 57  having a Gel Bed Permeability of from about 10×10 −8  cm 2  to about 300×10 −8  cm 2  as set forth herein in the Gel Bed Permeability Test. 
     
     
         61 . The particulate superabsorbent polymer of  claim 57 , wherein said silane compound is selected from one of the following 
       
         
           
           
               
               
           
         
         wherein 
         R 1  represents C 2  to C 3  alkenyl, 
         R 2  represents H, C 1  to C 4  alkyl, C 2  to C 5  alkenyl, C 6  to C 8  aryl, C 2  to C 5  carbonyl, 
         R 3  represents H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         R 4  and R 5  independently represent H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         m represents an integer of from 1 to 2, 
         n represents an integer of from 2 to 3, 
         l represents an integer of from 0 to 1, 
         m+n+1=4, 
         x represents an integer larger than 1, and 
         y represents an integer of 0 or larger than 0. 
       
     
     
         62 . The particulate superabsorbent polymer according to  claim 61 , wherein said silane compound is selected from vinyltriisopropenoxy silane, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinyl silane, and polysiloxane comprising at least two vinyl groups. 
     
     
         63 . A particulate superabsorbent polymer composition comprising a superabsorbent polymer comprising:
 a) at least one monomer selected from an ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid anhydride, salts or derivatives thereof based on the superabsorbent polymer;   b) from about 0.001% by weight to about 5% by weight of a first internal crosslinking agent and second internal crosslinking agent, based on the monomer of a) wherein the first internal crosslinking agent comprises a silane compound comprising at least one vinyl group or allyl group and at least one Si—O bond wherein the vinyl group or allyl group is directly attached to a silicon atom; and   c) a salt forming cation wherein the superabsorbent polymer has a degree of neutralization of greater than about 25%;   
       wherein elements a), b) and c) are polymerized into a crosslinked hydrogel, which is then prepared into superabsorbent polymer particles; and the particulate superabsorbent polymer composition further comprises a surface coating comprising ethylene carbonate, aluminum sulfate and maleated polypropylene, wherein said particulate superabsorbent polymer composition has a Centrifuge Retention Capacity of from 25 g/g to about 55 g/g as set forth herein in the Centrifuge Retention Capacity Test and having a Vortex time of from about 20 to about 180 sec. 
     
     
         64 . The particulate superabsorbent polymer composition of  claim 63 , wherein said silane compound is selected from one of the following 
       
         
           
           
               
               
           
         
         wherein 
         R 1  represents C 2  to C 3  alkenyl, 
         R 2  represents H, C 1  to C 4  alkyl, C 2  to C 5  alkenyl, C 6  to C 8  aryl, C 2  to C 5  carbonyl, 
         R 3  represents H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         R 4  and R 5  independently represent H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         m represents an integer of from 1 to 2, 
         n represents an integer of from 2 to 3, 
         l represents an integer of from 0 to 1, 
         m+n+1=4, 
         x represents an integer larger than 1, and 
         y represents an integer of 0 or larger than 0. 
       
     
     
         65 . The particulate superabsorbent polymer composition according to  claim 64 , wherein said silane compound is selected from vinyltriisopropenoxy silane, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinyl silane, and polysiloxane comprising at least two vinyl groups. 
     
     
         66 . The particulate superabsorbent polymer composition of  claim 63 , having a Gel Bed Permeability of from about 50×10 −8  cm 2  to about 300×10 −8  cm 2  as set forth herein in the Gel Bed Permeability Test. 
     
     
         67 . A particulate superabsorbent polymer comprising a polymerized monomer selected from an ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid anhydride, salts or derivatives thereof, and an internal crosslinker agent comprising a silane compound comprising at least one or allyl group and at least one Si—O bond, wherein the vinyl group or allyl group is directly attached to a silicon atom, wherein the superabsorbent polymer composition is a particulate superabsorbent composition and the particulate superabsorbent polymer surface treated with an inorganic salt. 
     
     
         68 . The particulate superabsorbent polymer of  claim 67 , wherein the particulate superabsorbent polymer has a Centrifuge Retention Capacity of from about 25 g/g to about 55 g/g as set forth herein in the Centrifuge Retention Capacity Test and having a Vortex time of from about 20 to about 60 sec. 
     
     
         69 . The particulate superabsorbent polymer of  claim 67 , wherein the particulate superabsorbent polymer has a Absorbency Under Load at 0.9 psi of about 15 g/g to about 25 g/g as set forth herein in the Absorbency Under Load at 0.9 psi Test. 
     
     
         70 . The particulate superabsorbent polymer of  claim 67  having a Gel Bed Permeability of from about 10×10 −8  cm 2  to about 300×10 −8  cm 2  as set forth herein in the Gel Bed Permeability Test. 
     
     
         71 . The particulate superabsorbent polymer of  claim 67 , wherein said silane compound is selected from one of the following 
       
         
           
           
               
               
           
         
         wherein 
         R 1  represents C 2  to C 3  alkenyl, 
         R 2  represents H, C 1  to C 4  alkyl, C 2  to C 5  alkenyl, C 6  to C 8  aryl, C 2  to C 5  carbonyl, 
         R 3  represents H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         R 4  and R 5  independently represent H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         m represents an integer of from 1 to 2, 
         n represents an integer of from 2 to 3, 
         l represents an integer of from 0 to 1, 
         m+n+1=4, 
         x represents an integer larger than 1, and 
         y represents an integer of 0 or larger than 0. 
       
     
     
         72 . The particulate superabsorbent polymer according to  claim 71  wherein said silane compound is selected from vinyltriisopropenoxy silane, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinyl silane, and polysiloxane comprising at least two vinyl groups. 
     
     
         73 . A particulate superabsorbent polymer composition comprising a superabsorbent polymer comprising:
 a) at least one monomer selected from an ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic acid anhydride, salts or derivatives thereof based on the superabsorbent polymer;   b) from about 0.001% by weight to about 5% by weight of a first internal crosslinking agent and second internal crosslinking agent, based on the monomer of a) wherein the first internal crosslinking agent comprises a silane compound comprising at least one vinyl group or allyl group and at least one Si—O bond wherein the vinyl group or allyl group is directly attached to a silicon atom; and   c) a salt forming cation wherein the superabsorbent polymer has a degree of neutralization of greater than about 25%;   
       wherein elements a), b) and c) are polymerized into a crosslinked hydrogel, which is then prepared into superabsorbent polymer particles; and the particulate superabsorbent polymer composition further comprises a surface coating comprising ethylene carbonate, aluminum sulfate and maleated polypropylene, wherein said particulate superabsorbent polymer composition has a Centrifuge Retention Capacity of from 25 g/g to about 55 g/g as set forth herein in the Centrifuge Retention Capacity Test and having a Vortex time of from about 20 to about 180 sec. 
     
     
         74 . The particulate superabsorbent polymer composition of  claim 63 , wherein said silane compound is selected from one of the following 
       
         
           
           
               
               
           
         
         wherein 
         R 1  represents C 2  to C 3  alkenyl, 
         R 2  represents H, C 1  to C 4  alkyl, C 2  to C 5  alkenyl, C 6  to C 8  aryl, C 2  to C 5  carbonyl, 
         R 3  represents H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         R 4  and R 5  independently represent H, C 1  to C 4  alkyl, C 6  to C 8  aryl, 
         m represents an integer of from 1 to 2, 
         n represents an integer of from 2 to 3, 
         l represents an integer of from 0 to 1, 
         m+n+1=4, 
         x represents an integer larger than 1, and 
         y represents an integer of 0 or larger than 0. 
       
     
     
         75 . The particulate superabsorbent polymer composition according to  claim 64 , wherein said silane compound is selected from vinyltriisopropenoxy silane, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, diethoxymethylvinyl silane, and polysiloxane comprising at least two vinyl groups. 
     
     
         76 . The particulate superabsorbent polymer composition of  claim 63  having a Gel Bed Permeability of from about 50×10 −8  cm 2  to about 300×10 −8  cm 2  as set forth herein in the Gel Bed Permeability Test and having a Vortex time of from about 20 to about 180 sec.