Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1995-06-22
1997-07-29
Merriam, Andrew E. C.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
523200, 523205, 523220, 523223, 524534, 524801, 524823, 525252, 526200, 526207, C08F22006, C08F26502
Patent
active
056522924
DESCRIPTION:
DESCRIPTION
EXAMPLES 1-29
An aqueous monomer mixture is formed by adding to 172.8 grams of water: 116 grams of acrylic acid; 110 grams of a 50 percent aqueous solution of sodium hydroxide; 0.23 grams methylenebisacrylamide; 4.6 grams of a 10 percent aqueous solution of VERSENEX 80 chelating agent (a pentasodium salt of diethylenetriamine pentacetic acid for scavenging metal compounds) supplied by The Dow Chemical Company; and, as a first portion of a partially continuous organic phase soluble crosslinker, the amount of trimethylolpropane triacrylate (TMPTA) indicated in Table I as "first crosslinker".
A continuous medium organic phase is formulated at low speed in a Waring blender/mixer, including 400 grams of ISOPAR.TM. M, a hydrocarbon supplied by Exxon Chemicla Co; and a suspending agent that is a mixture of 0.3 grams of AEROSIL.TM. R-972 (a hydrophobic silica supplied by Degussa, Inc; and 0.48 grams of a copolymer of 1 percent by weight acrylic acid and 99 percent by weight laurylmethacrytate.
To 200 g of the aqueous monomer solution, 0.5 mL of a 6.1 percent aqueous solution of sodium persulfate is added. The organic phase is mixed for 10 seconds at low speed in the Waring blender. The speed of the blender is increased to 800 rpm and the 200 g of the aqueous solution is added and stirred for 30 seconds. The resulting suspension is transferred to a reactor, where it is purged for 30 minutes with nitrogen. To the purged mixture, 1 mL of an 8.9 percent aqueous solution of t-butyl hydroperoxide is added. The suspension is purged an additional 10 minutes.
The polyacrylate polymerization is initiated by bubbling sulfur dioxide diluted in nitrogen into the reaction mixture. The agitation rate in the reactor is as indicated in Table I.
When the mixture temperature reaches 50.degree. C., (unless otherwise indicated in Table I), the indicated amount of trimethylolpropane triacrylate as a "second crosslinker" is added. The reaction proceeds exothermically and is maintained at a temperature of 65.degree. C. for one hour.
The ISOPAR hydrocarbon organic phase is then removed by filtration and the polymer product dried. The dry polymer is slurried in a mixture of 0.03 grams of VORANOL.TM. 2070 polyol, available from The Dow Chemical Company (Midland, Mich.), in methanol to provide 1 weight percent polyol based on the weight of the polymer material. The methanol is removed by vacuum stripping at 80.degree. C.
The aqueous absorbent polymer material of the invention which comprises clusters of a plurality of individual particles of absorbent polymer, is analyzed for particle size distribution, vortex rate, 5 minute 0.3 psi AUL and 60 minute 0.3 psi AUL. These data appear in Table 1 below.
TABLE I __________________________________________________________________________
Amount of
second Centrifuge
Amount of first
crosslinker
Agitation
Vortex rate
AUL (g/g)
Capacity
Example
crosslinker (g)
(g).sup.1
rate (rpm)
(sec) 5 min
60 min
(g/g)
__________________________________________________________________________
1 0.345 0.55 400 41 16.9
20.0
19.1
2 0.345 0.55 600 2.6 23.0
24.2
22.9
3 0.345 0.55 800 15.7 22.6
23.6
20.4
4 0.345 0.55 800 5.0 24.3
25.1
22.6
5 0.46 0.55 400 3.9 25.1
26.0
24.0
6 0.46 0.55 600 6.0 24.8
25.4
23.2
7 0.46 0.55 600 15.4 20.7
22.6
19.3
8 0.46 0.55 600 3.1 24.9
25.8
24.3
9 0.46 0.55 600 2.9 24.8
26.4
24.3
10 0.46 0.55 (40.degree. C.)
600 2.3 23.7
24.6
22.5
11 0.46 0.55 (45.degree. C.)
600 5.3 23.1
24.4
22.4
12 0.46 0.55 (45.degree. C.)
600 5.4 23.3
24.7
22.8
13 0.46 0.55 (54.5.degree. C.)
600 2.3 23.7
24.6
22.5
14 0.46 0.55 (54.5.degree. C.)
600 5.5 23.1
24.5
22.2
15 0.46 0.55 (54.5.degree. C.)
600 8.6 25.1
25.6
24.2
16 0.46 0.55 (54.5.degree. C.)
600 2.8 15.0
15.3
13.8
17 0.46 0.55 (54.5.degree. C.)
600 8.9 25.1
26.9
24.8
18 0.46 0.55 (54.5.degree. C.)
600 10.3 23.7
24.0
21.9
19 0.46 0.55 (54.5.degree. C.)
600 9.4 24.8
26.5
23.3
20 0.46 0 600 9.8 21.0
22.6
20.8
21 0.46 0.55 800 5.3 25.5
26.2
24.0
22 0.46 0.55 800 4.5 24.2
2
REFERENCES:
patent: 4134815 (1979-01-01), Jackson et al.
patent: 4446261 (1984-05-01), Yamasaki et al.
patent: 4666975 (1987-05-01), Yamasaki et al.
patent: 4683274 (1987-07-01), Nakamura et al.
patent: 4708997 (1987-11-01), Stanley et al.
patent: 4833222 (1989-05-01), Siddall et al.
patent: 5374684 (1994-12-01), Tai
Merriam Andrew E. C.
The Dow Chemical Company
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