US2017210831A1PendingUtilityA1
Water-absorbent resin and method of producing water-absorbent resin
Est. expiryJul 11, 2034(~8 yrs left)· nominal 20-yr term from priority
A61F 13/49C08J 2205/022C08F 8/14C08J 3/245A61F 13/15C08F 2/32A61F 13/53C08K 5/23A61L 15/60C08K 5/14B01J 20/267A61L 15/24
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Claims
Abstract
Provided is a water-absorbent resin that increases the diffusivity of a to-be-absorbed liquid and that makes it possible to effectively decrease the amount of re-wet. The water-absorbent resin is obtained by polymerizing a water-soluble ethylenicallyally unsaturated monomer under the presence of an internal-crosslinking agent, has the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption of 20 ml/g or more, and exhibits the degree of swelling under a load at 30 minutes of 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes from the start of water absorption is designated as the degree of swelling under a load of 100%.
Claims
exact text as granted — not AI-modified1 . A method of producing a water-absorbent resin by performing reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent in a hydrocarbon dispersion medium, the method comprising the steps of:
performing polymerization step in the presence of an azo based compound and a peroxide, and performing post-crosslinking step of a hydrous gel-like material obtained from the polymerization using a post-crosslinking agent.
2 ). The method of producing a water-absorbent resin according to claim 1 , wherein the azo based compound is at least one selected from the group consisting of 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis{2-[1-(2-hydroxyethyl)-2-imidazoline-2-yl]propane}dihydrochloride and 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropione amidine]tetrahydrate.
3 . The method of producing a water-absorbent resin according to claim 1 , wherein the peroxide is at least one selected from the group consisting of potassium persulfate, ammonium persulfate, sodium persulfate and hydrogen peroxide.
4 . The method of producing a water-absorbent resin according to claim 1 , wherein the internal-crosslinking agent is at least one selected from the group consisting of (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether and (poly)glycerin diglycidyl ether.
5 . A water-absorbent resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer in the presence of an internal-crosslinking agent, and performing post-crosslinking with a post-crosslinking agent, wherein
a water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is 20 ml/g or more, and the degree of swelling under a load at 30 minutes is 70% or less when the water-absorption capacity of physiological saline under a load of 4.14 kPa at 120 minutes passed from the start of water absorption is taken as a degree of swelling under a load of 100%, and the degree of swelling under a load at a certain time passed is calculated by the following formula:
Degree
of
swelling
under
a
load
at
a
certain
time
passed
(
%
)
=
Water
absorption
capacity
for
physiological
saline
under
a
load
of
4.14
kPa
at
a
certain
time
passed
(
ml
/
g
)
Water
absorption
capacity
for
physiological
saline
under
a
load
of
4.14
kPa
at
120
minutes
passed
(
ml
/
g
)
×
100
[
Formula
1
]
6 . An absorbent article using an absorbent material comprising the water-absorbent resin according to claim 5 .
7 . The method of producing a water-absorbent resin according to claim 2 , wherein the peroxide is at least one selected from the group consisting of potassium persulfate, ammonium persulfate, sodium persulfate and hydrogen peroxide.
8 . The method of producing a water-absorbent resin according to claim 2 , wherein the internal-crosslinking agent is at least one selected from the group consisting of (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether and (poly)glycerin diglycidyl ether.
9 . The method of producing a water-absorbent resin according to claim 3 , wherein the internal-crosslinking agent is at least one selected from the group consisting of (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether and (poly)glycerin diglycidyl ether.
10 . The method of producing a water-absorbent resin according to claim 7 , wherein the internal-crosslinking agent is at least one selected from the group consisting of (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether and (poly)glycerin diglycidyl ether.Join the waitlist — get patent alerts
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