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Patent 1340500 Summary

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(12) Patent: (11) CA 1340500
(21) Application Number: 1340500
(54) English Title: WATER ABSORBENT POLYMER AND METHOD OF PRODUCTION THEREOF
(54) French Title: POLYMERE ABSORBANT L'EAU ET METHODE DE PRODUCTION
Status: Expired and beyond the Period of Reversal
Bibliographic Data
(51) International Patent Classification (IPC):
  • C08F 220/06 (2006.01)
  • B01J 20/26 (2006.01)
  • C08F 2/32 (2006.01)
  • C08F 8/00 (2006.01)
(72) Inventors :
  • KANBAYASHI, TAIJI (Japan)
  • KATO, CHUZO (Japan)
(73) Owners :
  • OOSAKA YUUKI KAGAKU KOGYO KABUSHIKI KAISHA
(71) Applicants :
  • OOSAKA YUUKI KAGAKU KOGYO KABUSHIKI KAISHA (Japan)
(74) Agent: MARKS & CLERK
(74) Associate agent:
(45) Issued: 1999-04-13
(22) Filed Date: 1985-09-04
Availability of licence: N/A
Dedicated to the Public: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
94308/1988 (Japan) 1988-04-16

Abstracts

English Abstract


Water absorbent polymer capable of keeping absorbed
water therein in the form of independent grains and having
the property of slipping between particles is produced by:
a) dissolving acrylic copolymer as dispersing agent in a
liquid aliphatic hydrocarbon; b) partially neutralizing an
acrylic acid monomer in aqueous solution with an alkali to
form an aqueous solution of partially neutralized acrylic
acid; c) dispersing the aqueous solution of partially
neutralized acrylic acid of b) in the solution of acrylic
copolymer of a) to polymerize by w/o suspension
polymerization; and d) subjecting the resultant polymer of c)
to crosslinking reaction in the presence of crosslinking
agents and in the presence or absence of an inorganic
compound to dry.


Claims

Note: Claims are shown in the official language in which they were submitted.


The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:
1. A water-absorbent polymer in particulate form
capable of absorbing water by clathration, characterised in
that the water-absorbent polymer is an acrylic polymer
based on partially-neutralised acrylic acid, incorporating
a polymeric dispersing agent comprising an acrylic
copolymer linked to the water-absorbent polymer by a
cross-linking reaction in the preparation of said polymer using
an amount of cross-linking agent which is from 0.05 to 2
weight percent relative to the amount of the partially-neutralized
acrylic acid, that the acrylic copolymer has an
alkyl acrylate or methacrylate monomer having an alkyl
group of eight carbon atoms or more as a main component,
and that the surfaces of the polymer particles are modified
so that the polymer particles retain their independent
particulate form and are able to move past each other even
after absorption of water by the polymeric dispersing
agent.
2. A particulate water-absorbent polymer according
to claim 1, wherein the acrylic polymer is obtained by
water-in-oil suspension polymerisation in the presence of
the acrylic copolymer polymeric dispersing agent.
-27-

3. Particles of a water-absorbent polymer according
to claim 1 or 2, containing absorbed water in an amount
less than half their water absorbency but retaining their
particulate form and able to move past one another without
sticking.
4. Particles as claimed in claim 3, having a
particle size from 0.03 to 3.0 mm.
5. A method for the production of a water-absorbent
particulate polymer capable of absorbing water by
clathration, which method comprises:
(1) dissolving an acrylic copolymer as dispersing agent in
a liquid aliphatic hydrocarbon, said acrylic copolymer
being formed from the following components:
(a) an alkyl acrylate or methacrylate monomer having
an alkyl group of eight carbon atoms or more, in an
amount of 40 to 95 weight percent,
(b) one or more hydrophilic monomers selected from
acrylic acid and derivatives, methacrylic acid and
derivatives, acrylamide and derivatives and
methacrylamide and derivatives, all containing a
carboxyl, amino, quaternary ammonium or hydroxyl
group, in an amount of 5 to 40 weight percent, and
(c) unsaturated monomer copolymerisable with the
-28-

components (a) and (b) in an amount of 0 to 40 weight
percent;
(2) partially neutralizing an acrylic acid monomer in
aqueous solution with an alkali to form an aqueous solution
of partially-neutralized acrylic acid;
(3) dispersing the aqueous solution of partially-neutralized
acrylic acid obtained in (2) in the solution of
acrylic copolymer obtained in (1), and polymerizing the
acrylic acid by water-in-oil suspension polymerization;
(4) subjecting the particulate polymer obtained in (3) to a
cross-linking reaction with a cross-linking agent in the
presence or absence of an inorganic compound; and
(5) drying the polymer particles, whereby the polymer
particles retain their independent particulate form and are
able to move past each other even after absorption of
water.
6. A method for the production of water-absorbent
polymer beads which retain a bead-like shape after
absorption of water, which method comprises:
(1) dissolving a copolymer as a dispersing agent in an
aliphatic hydrocarbon to form a solution, the copolymer
comprising the following:
(a) an alkyl acrylate or methacrylate monomer having
an alkyl group of eight or more carbon atoms, in the
amount of 45 to 70 weight percent,
-29-

(b) one or more kinds of monomers selected from the
group consisting of acrylic acid, methacrylic acid,
itaconic acid, dimethylaminoethyl acrylate,
dimethylaminoethyl methacrylate, diethylaminoethyl
acrylate, diethylaminoethyl methacrylate,
acryloyloxyethyltrimethylammonium chloride,
methacryoyloxyethyltrimethylammonium chloride, 2-hydroxyethyl
acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl
acrylate, 2-hydroxypropyl methacrylate, acrylamide,
dimethylacrylamide, dimethylaminopropyl-acrylamide,
dimethylaminopropylmethacrylamide,
acrylamidepropyltrimethylammonium chloride, and
methacrylamidepropyltrimethylammonium chloride, in the
amount of 5 to 25 weight percent, and
(c) unsaturated monomers having affinity with an
aliphatic hydrocarbon solvent selected from the group
consisting of alkyl methacrylates wherein the alkyl
group contains less than 5 carbon atoms and vinyl
acetate, being capable of copolymerizing with the
above-mentioned (a) and (b) so as to raise the glass
transition temperature of said copolymer, in the
amount of 20 to 40 weight percent;
(2) dispersing a solution of an acrylic acid and an alkali
metal salt of an acrylic acid obtained by partially
neutralizing an acrylic acid, in said solution of said
copolymer in said aliphatic hydrocarbon, and then
-30-

polymerizing the resultant mixture by water/oil suspension
polymerization so as to subject said resultant mixture to a
self-crosslinking reaction;
(3) subjecting said resultant polymer of (2) to a
crosslinking reaction in the presence or absence of an
inorganic compound by means of crosslinking agent; and
(4) drying to form beads.
7. A method for the production of a water-absorbent
polymer according to claim 5 or 6, wherein the
cross-linking agent is ethylene glycol diglycidyl ether.
8. A method for the production of a water-absorbent
polymer according to claim 5, 6 or 7, wherein the amount of
cross-linking agent is from 0.05 to 2 weight percent,
relative to the amount of the partially-neutralized acrylic
acid.
9. A method according to any one of claims 5 to 8,
in which the acrylic copolymer is formed from 45 to 70
weight percent of (a), 5 to 25 weight percent of (b) and 20
to 40 weight percent of (c).
-31-

10. A method according to any one of claims 5 to 9,
in which the polymerisation of the partially-neutralized
acrylic acid is initiated by a self-cross-linking
initiator used in an amount of 0.1 to 2.0 weight percent,
based on the partially-neutralized acrylic acid.
11. A method according to any one of claims 5 to 10,
in which the cross-linking is carried out in the presence
of an inorganic compound selected from white carbon, talc,
hydrotalcite and pulverised silica.
12. A particulate water-absorbent polymer produced by
the method according to any one of claims 5 to 11.
13. Particles of a water-absorbent polymer according
to claim 12, containing absorbed water in an amount less
than half their water absorbency but retaining their
particulate form and able to move past one another without
sticking.
14. Particles as claimed in claim 13, having a
particle size from 0.03 to 3.0 mm.
-32-

Description

Note: Descriptions are shown in the official language in which they were submitted.


1~115~3
This is a divisional application of copending
application S96,790, filed April 14, 1989.
This invention relates to a method for the production of
fine grain ice or dry clathrate water for manufacture of
concrete/mortar, a method for the production of
concrete/mortar by using fine grain ice or dry clathrate
water and concrete/mortar products manufactured by the
method. Fine grain ice and dry clathrate water for
manufacturing concrete/mortar produced by this invention are
used when concrete/mortar is manufactured by the use of a
small amount of water.
Thus, concrete/mortar can now be easily manufactured by
making use of fine grain ice or dry clathrate water at a
place where it is difficult to supply water.
In the case where concrete/mortar is manufactured by a
conventional method, much more water is used than the amount
of water necessary for hydration of cement in order to
uniformly mix and temper the cement and water and to keep
good flowability as well. However, there is a disadvantage
in this method in that the strength and durability of the
concrete/mortar after solidification are lower than the
concrete/mortar produced by use of the amount of water close
to the theoretical hydration quantity.
For this reason, the technique to mix cement or cement
_ _ . . ... . . . .....

1340~00
and aggregate with fine grain ice instead of water has been
studied. The features are as follows.
1) Since a powder mixture can be prepared with the
cement, mixing can be performed at a low water/cement ratio.
2) Slump loss in proportion to the passage of time is
small after mixing.
3) The temperature of mass concrete can be easily
controlled.
In the case where this concrete mixing technique is
actually applied, however, it is necessary to manufacture
fine grain ice and this method presents a problem. In the
conventional method, fine grain ice is obtained by crushing
an ice block. In the case where fine grain ice is obtained
by crushing an ice block, the defects are as follows.
1 ) In the case where a large amount of fine grain ice
is needed, a big plant equipped with special devices such as
an ice crusher and a slicer is necessary.
2) Fine grain ice must be kept at low temperature until
it is used and an ice storage unit is necessary to do so.
Therefore, the control of the manufacturing process is
troublesome and the cost is high.
The present inventors have conducted studies
in order to avoid these conventional defects and have
.

, 13~0.iOo
perfected a method to accomplish this as follows. That is,
when fine grain ice or dry clathrate water are used for a
cement mixture, concrete/mortar can be easily manufactured by
using a small amount of water without the above-mentioned ice
storage unit. According to the present invention, fine grain
ice is made by impregnating water into a water absorbent
polymer, capable of keeping separate fine grains by freezing
the water in the polymer structure. And, dry clathrate water
is made in such a manner that water is impregnated into the
water absorbent polymer.
The method for the production of fine grain ice or dry
clathrate water for manufacturing of concrete/mortar in the
present invention has the following characteristics.
1) Fine grain ice or dry clathrate water particles
having stable particle size can be easily manufactured.
2) It is unnecessary to keep fine grain ice at low tem-
perature until it is used and it can be used as is or by
freezing just before mixture.
3) It is unnecessary to manufacture it at a specified
place and manufacture can be easily performed at an optional
place in the available time.
4) The method can be easily applied to an existing
ready-mixed concrete plant.
S) Water can be transported as fine particles to a
place where it is impossible to supply water.
.,

1340~03
The method for the production of concrete/mortar in the
present invention has the following characteristics.
1) Low water cement ratio of high strength
concrete/mortar can be easily manufactured.
2) Continuous production is easy to achieve by
extrusion molding and roller molding. And, products can be
easily encreased in length.
3) Since water absorbent polymer is mixed in with the
cement, a remarkable effect is observed in the prevention of
surface dew condensation and efflorescence.
In one specific aspect, the parent application
provides, a method for the production of concrete/mortar,
which consists essentially of:
lS a) mixing water with polymer particles capable of
retaining their particulate shape when substantial quantities
of water are absorbed therein, said particles being produced
by a process which comprises:
i) forming an acrylic copolymer dispersing agent
having an alkyl acrylate or methacrylate monomer
having an alkyl group of eight or more carbon
atoms as main component;
ii) dissolving said acrylic copolymer of i) in a
liquid aliphatic hydrocarbon,
iii) partially neutralizing an acrylic acid monomer
in aqueous solution with an alkali to form an
, .. ....

13~ p:~ oo
aqueous solution of partially neutralized
acrylic acid,
iv) adding the aqueous alkali solution of partially
neutralized acrylic acid of iii) to a solution
of acrylic copolymer of ii) and polymerizing the
resultant mixture by water/oil suspension
polymerization, and
v) subjecting the resultant polymer of iv) to a
cross-linking reaction in the presence of a
cross-linking agent and in the presence or
absence of a particulate inorganic compound;
b) mixing cement or cement and aggregate with said
product of step a) and
c) expelling the water absorbed in said polymer
particles in the mixture of b) to the outside
thereof by a molding method so as to cause hydration
of said cement.
Preferably the molding method comprises pressing or
extrusion.
Suitably the polymer particles containing water from
step a) are frozen prior to step b) and melted when desired
to cause hydration of the cement.

134 D .~ 00
The present invention discloses and claims in one aspect
water absorbent polymer being polymerized and formed by using
an acrylic copolymer as a dispersing agent, said acrylic
copolymer comprising an alkyl acrylate or methacrylate
monomer having an alkyl group of eight or more carbon atoms
as a main component, said water absorbent polymer being
capable of keeping absorbed water therein in the form of
independent grains and having the property of each grain
slipping by each other.
In a further aspect there is provided a method for the
production of a water absorbent polymer which comprises:
a) dissolving an acrylic copolymer as a dispersing agent in a
liquid aliphatic hydrocarbon; b) partially neutralizing an
acrylic acid monomer in an aqueous solution with an alkali to
form an aqueous solution of partially neutralized acrylic
acid; c) dispersing the aqueous solution of partially
neutralized acrylic acid of b) in the solution of acrylic
copolymer of a) to polymerize by w/o suspension
polymerization; and d) subjecting the resultant polymer of c)
to a crosslinking reaction in the presence of a crosslinking
agent and in the presence or absence of an inorganic
compound, and to drying.
In preferred embodiments of this further aspect there
are provided:
- 5a -

13~00
The above method wherein the acrylic copolymer is alkyl
acrylate or methacrylate monomer having an alkyl group of
eight or more carbon atoms as a main component.
The above method wherein the acrylic copolymer is a
S copolymer in which the following are components: a) an alkyl
acrylate or methacrylate monomer having an alkyl group of
eight or more carbon atoms, in the amount of 40 to 95 weight
percent: b) a monomer selected from acrylic acid derivatives,
methacrylic acid derivatives, acrylic amide derivatives,
methacrylic amide derivatives having hydrophilicity and a
mixture thereof, in the amount of S to 40 weight percent; and
c) unsaturated monomers capable of copolymerizing said (a)
and (b), in the amount of 0 to 40 weight percent.
The above method wherein the crosslinking agent is
ethylene glycol diglycidyl ether.
The above method wherein the amount of the crosslinking
agent is O.OS to 2 weight percent relative to the amount of
the partially neutralized acrylic acid.
- Sb -
.. . . .. ..

1340 -00
The invention will be described in more detail by
reference to the accompanying drawings, in which:
Fig.l is a table which depicts the glass transition
point of certain monomers; and
Fig.2 is a table which depicts the result of an
evaluation of the water absorbent polymers in the Examples 1
through 6 and the Comparison Examples 1 through 3.
The water absorbent polymer for use in the present
invention is obtained by dissolving acrylic copolymer in an
aliphatic hydrocarbon to form a solution, and dispersing
acrylic acid and an alkali metal salt aqueous solution
thereof in said solution. Polymerization is performed by a
water/oil (W/0) type suspension polymerization method and
crosslinking is then performed in the presence or absence of
an inorganic compound by means of a crosslinking agent
followed by drying.
An acrylic copolymer to be used as a dispersing agent
when the water absorbent polymer for use in the present
invention is manufactured, is a copolymer in which the
following are the components.
(a) Alkyl acrylate or alkyl methacrylate monomers in
which the number of carbons in the alkyl groups is 8 or more
are present at 40-95 weight percent.
, . . . .

1340501~
(b) One or more kinds of monomers selected from acrylic
acid derivatives, methacrylic acid derivatives, acrylic amide
derivatives and methacrylic amide derivatives containing a
carboxyl group, an amino group, a quarternary ammonium group
or a hydroxyl group are present at 5-40 weight percent.
(c) Unsaturated monomers capable of copolymerizing with
the above-mentioned (a), (b) are present at 0-40 weight
percent.
Any alkyl acrylates or alkyl methacrylates are suitable
for component (a) if the number of carbons of the alkyl
groups is at least 8. Monomers which are commercially
available are 2-ethylhexyl acrylate, 2-ethylhexyl
methacrylate, lauryl acrylate, lauryl methacrylate, tridecyl
acrylate, tridecyl methacrylate, a mixture of lauryl acrylate
and tridecyl acrylate, stearyl acrylate, stearyl methacrylate
and the like.
In selecting component (a20 transition point is, the harder it is for beads blocking to
'~/~
occur when the dispersing agent is synthesized in an Q~d type
suspension polymerization. Therefore, a higher glass
transition point is convenient. The glass transition point
of each monomer is shown in Fig.l.~5
For instance, 2-ethylhexyl methacrylate, lauryl acry-
,

,.~ 13~50i)
late, a mixture of lauryl acrylate and tridecyl acrylate,tridecyl acrylate, stearyl acrylate, stearyl methacrylate and
the like are available for use herein.
The acrylic acid derivatives, methacrylic acid deriva-
tives, acrylic amide derivatives or methacrylic amide
derivatives containing a carboxyl group, an amino group, a
quarternary ammonium group or a hydroxyl group of the
component (b) include acrylic acid, methacrylic acid,
itaconic acid, dimethylaminoethyl acrylate,
dimethylaminoethyl methacrylate, diethylaminoethyl acrylate,
diethylaminoethyl methacrylate,
acryloyloxyethyltrimethylammonium chloride,
methacryloyloxyethyltrimethylammonium chloride, 2-
hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-
hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
acrylamide, dimethylacrylamide,
dimethylaminopropylacrylamide,
dimethylaminopropylmethacrylamide,
2~ acrylamidepropyltrimethylammonium chloride,
methacrylamidepropyltrimethylammonium chrolide and the like.
Monomers for use as component (c) are alkyl
methacrylates in which the glass transition point is high,
having affinity for aliphatic hydrocarbon solvents and the
.. . . .... .. . . .. . ..

'- 1340~00
monomers in which the numbers of carbons of the alkyl group
is less than 5 and vinyl acetate are examples. For instance,
methyl methacrylate, ethyl methacrylate, isopropyl
methacrylate, n-butyl methacrylate, isobutyl methacrylate and
vinyl acetate are suitable and methyl methacrylate, ethyl
methacrylate and isobutyl methacrylate are preferred.
The ratio of the components (a), (b) and (c) largely
influences the dispersion solubility to aliphatic hydrocarbon
solvents, colloid dispersibility of polymerization and the
properties of the water absorbent polymer, for instance,
water absorbency, particle independence when water is
absorbed, particle strength and particle size.
In general, component (a) is present at 40-95 weight
percent, component (b) is present at 5-40 weight percent and
component (cj is present at 0-40 weight percent as suitable
values. It is preferred that component (a) is present at 45-
70 weight percent, component (b) is present at 5-25 weight
percent and component (c) is present at 20-40 weight percent.
In the case where component (a) is less than 40 weight
percent, the dispersion solubility to solvent is lowered. In
the case where component (a) is more than 95 weight percent,
the colloid dispersibility becomes relatively worse when
component (b) is less than 5 weight percent. In both cases,
it is difficult to continue W/0 type suspension
., ~ .

~0501~
polymerization. The component (a) has a tendency such that
the higher the percentage by weight, i.e. in the range
between 40 and 95 weight percent, the better the dispersion
solubility to solvent, particle independence of water
absorbent polymer when water is absorbed and particle
strength become. In the case where component (b) is less
than 5 weight percent, the colloid dispersibility gets worse
as described before. In the case where the component (b) is
more than 40 weight percent, the dispersion solubility to
solvent is lowered. In both cases, it is difficult to
continue W/0 type suspension polymerization.
The component (b) has a tendency such that the higher
the percentage by weight, i.e. in the range between 5 and 40
weight percent, the better the colloid dispersibility of
polymerization is and the more the water absorbing rate of
water absorbent polymer accelerates. on the contrary, in
this case, the particle independence when water is absorbed
and the particle strength are lowered and the particle size
becomes fine. In the case where component (c) is more than
40 weight percent, the ratio of component (a) is relatively
lowered and the dispersibility to solvent becomes worse. The
higher the percentage by weight is in the range between o and
40 weight percent, the higher is the particle strength of the
water absorbent polymer.
.. . . ... .. . ... . .

--- 13'105~1)
An acrylic copolymer which is used as a dispersing agent
in the present invention is synthesized by means of an O/W
type suspension polymerization method. If solution
polymerization is used, there are a few cases where solvent
remains or the function as dispersing agent is inferior due
to low molecular weight of the resultant polymer.
An example of O/W type suspension polymerization method
is as follows. Partially saponified polyvinyl alcohol is
heated and dissolved in ion exchange purified water. After
the atmosphere is replaced with N2, the solution in which an
azo type or peroxide type initiator is dissolved is added
dropwise and is dispersed in the monomer components (a), (b),
(c) and the polymerization is finished by continuation of
heating. After cooling, solid matter is filtered and washed
and bead-like acrylic copolymer, that is, dispersing agent,
is obtained by drying under reduced pressure.
The dispersing agent obtained by the above-described
method is dispersed and dissolved in the aliphatic
hydrocarbon solvent of the W/O type suspension
polymerization. The dispersing agent is used in the 0.1 to
10 weight percent range with respect to acrylic acid and its
alkali metallic salt monomer and the preferred range is 0.5
to 5 weight percent. When the quantity of dispersing agent

1340~00
is less than 0.1 weight percent, the colloid dispersibility
of polymerization is labilized. When it is more than 10
weight percent, the fineness of the particle size becomes a
negative economic factor.
Acrylic acid and its alkali metal salt aqueous solutions
for use in the present invention are adjusted in such a
manner that the acrylic acid monomer is partially neutralized
by means of an aqueous solution such as sodium hydroxide and
potassium hydroxide. It is preferred in consideration of
water absorbency power and safety that the degree of
neutralization is 60 to 85~. The concentration of monomer in
aqueous solution is 35 to 75 weight percent and the preferred
concentration is 40 to 70 weight percent.
In the present invention, there is no difficulty that
unsaturated monomer capable of copolymerizing with acrylic
acid and its acrylic acid alkali metal salt monomer is
copolymerized with acrylic acid and its acrylic acid alkali
metal salt monomer during the manufacture of the water
absorbent polymer.
In the case where acrylic acid is polymerized with its
alkali metal salt aqueous solution by W/0 type suspension
polymerization method in the present invention, the initiator

1340500
is of the self-crosslinking type in which a cross-linking
agent monomer is not used. Therefore, the preferred
initiator is a water soluble persulfate such as potassium
persulfate and ammonium persulfate, and hydrogen peroxide.
The quantity of initiator is 0.1 to 2.0 weight percent to
monomer and the preferred quantity is 0.2 to 1.0 weight
percent.
The aliphatic hydrocarbon solvent for the W/0 type
suspension polymerization in the present invention is an
aliphatic hydrocarbon such as n-pentane, n-hexane, n-heptane
and n-octane, or an alicyclic hydrocarbon such as
cyclohexane, methylcyclohexane and decalin. The preferred
ones are n-hexane, n-heptane and cyclohexane.
When the water absorbent polymer is manufactured for the
present invention, the other important factor is that the
crosslinking reaction is performed by means of the cross-
linking agent in the presence or in the absence of an
inorganic compound after the W/0 type suspension
polymerization.
It is permissible that the cross-linking agent for use
in the present invention is a compound having two or more
functional groups capable of reacting with the carboxyl group

- - - - - - -
134 0 $0~
(or carboxylate group). Such a cross-linking agent may be a
polyglycidyl ether such as ethylene glycol diglycidyl ether,
polyethylene glycol diglycidyl ether and glycerin triglycidyl
ether, a haloepoxy compound such as epichlorohydrin and ~-
methyl chlorohydrin, a polyaldehyde such as glutaraldehydeand glyoxal and the like. The preferred one is ethylene
glycol glycidyl ether.
The amount of added cross-linking agent depends on the
type of cross-linking agent and the type of dispersing agent.
The range is usually 0.05 to 2 weight percent relative to the
acrylic acid and its alkali metal salt monomer. When the
quantity of the above-described cross-linking agent is less
than 0.05 weight percent, the particle independence when
lS water is absorbed and the particle strength are
unsatisfactory. When it is more than 2 weight percent, the
cross-linking density is too high. Therefore, the water
absorbency is too low.
With the cross-linking reaction, the particle inde-
pendence, when water is absorbed, increases by the addition
of an inorganic compound. The inorganic compound is, for
instance, white carbon, talc, hydrotalcite, pulverized silica
(commercially available under the trademark "Aerosil" made by
NIPPON AEROSIL KABUSHIKI KAISHA). Further, no difficulty
14

340~01~
arises if a surface active agent is added. Well known
nonionic surface active agents and the like are used.
The method of performing the cross-linking reaction is
to add the crosslinking agent during azeotropic distillation,
heating and drying under reduced pressure, as is well known,
and the addition during azeotropic distillation is easy.
The water absorbent polymer for use in the present in-
vention is different from commercially produced polymers and
shows particle independence when water is absorbed. The more
the component (a) acrylic copolymer dispersing agent employed
and the more cross-linking agent employed, the greater the
effects observed. It can, therefore, be presumed that slip-
page of water absorbed polymer affects the above-described
particle independence. The component (a) dispersing agent
upgrades the water repellency of the water absorbed polymer
as does upgrading the cross-linking rate of the polymer,
while the cross-linking agent increases the water absorbing
rate and decreases surface tacking. By these effects, the
water absorbed bead-like polymer slip by each other, become
porous and appear to effect particle independence and
flowability, since little water as binder is present.
Fine grain ice for production of concrete/mortar in the
... .. . . . . .

13 1050~
present invention is obtained in such a manner that the
above-mentioned water absorbent polymer absorbs the necessary
quantity of water to freeze so as to keep independent fine
grains. It is easily manufactured. Water can be absorbed up
to the water absorbency of the polymer (100 to 200 times of
the water absorbent polymer weight of ion exchange purified
water). And, dry clathrate water for production of
concrete/mortar is obtained only in such a manner that the
above-mentioned water absorbent polymer absorbs the necessary
quantity of water. It is desirable that the amount of water
to be absorbed is less than half of the water absorbency
capacity of the polymer in order to keep independent fine
grains.
The particle size of the fine grain ice or dry clathrate
water can be freely varied in the 0.03 to 3.0 mm range by
changing the particle size of the water absorbent polymer and
the amount of water to be absorbed, and can be selected in
accordance with the working conditions when the cement is
mixed.
Concrete/mortar is manufactured in such a manner that
fine grain ice or dry clathrate water of the present inven-
tion is mixed with the cement or cement and aggregate in
powder condition and after is expelled to the outer portion
by means of a pressure molding or extrusion molding method so
16
.. ...

13 ~i O?~OO
as to cause hydration of the surrounding cement.
The production method of the present invention will be
further explained according to the following examples.
However, the present invention is not restricted by these ex-
amples.
Water absorbency, particle size and particle indepen-
dence when water is absorbed were obtained by the following
methods as shown below.
The value of water absorbency of ion exchange purified
water was obtained in such a manner that dry polymer, 0.5 g,
was dispersed in ion exchange purified water, 1 L, and the
swelling polymer weight (W) was obtained by filtering, by
means of an 80-mesh wire gauze after standing for twenty-four
hours, was measured and this value was divided by the
original dry polymer weight (Wo). That is, it was decided
that the water absorbency of the ion exchange purified water
(g/g) was W/Wo.
The value of water absorbency of 0.9% salt water was
obtained in such a manner that dry polymer, 0.2 g, was dis-
persed in 0.9% salt water, 60 g. The swelling polymer weight
(W) obtained by filtering, by means of a 100-mesh wire gauze
after standing for twenty minutes, was measured and this
17

1340503
value was divided by the original dry polymer (Wo). That is,
it was decided that the water absorbency of 0.9% salt water
(g/g) was W/Wo.
The particle size of the water absorbent polymer (in dry
condition) was measured by means of an automatic grading dis-
tribution measuring apparatus CAPA-300 made by HORIBA
SEISAKUSHO KABUSHIKI KAISHA by using the decanter method. It
was decided that the median on a basis of the area was the
particle size.
It was decided that the particle size of the water
absorbed polymer was the average obtained on the basis of
photographing with an optical microscope after ion exchange
purified water, 50 cc, was added to dry polymer, 1.0 g, and
the polymer absorbed all of the water. The particle
independence when water was absorbed was judged by the
following standard.
o: Each particle is independent and has flowability.
~: Each particle is partially dependent and inferior in
flowability.
x: Each particle shows gelation dependence perfectly
and has no flowability.
The composition examples of the dispersing agent
18

1340~0~
' (acrylic copolymer) will be given hereinafter.
Composition Example 1
Ion exchange purified water, 150 g, was fed into a 500
ml separating flask equipped with an agitator, a reflux
condenser, a dropping funnel, a thermometer and a nitrogen
gas introduction tube. Partially saponified polyvinyl
alcohol (GH-23 made by NIHON GOHSEI KAGAKU KABUSHIKI KAISHA),
0.2 g, was added as a dispersing agent and the atmosphere was
replaced with N2 after heating and dissolution of the
materials.
Azobisdimethylvaleronitrile, 1.0 g, was added to a
mixture of lauryl acrylate and tridecyl acrylate (LTA made
by OHSAKA YUKI KAGAKU KABUSHIKI KAISHA) 32.5 g, hydroxy ethyl
methacrylate, 10.0 g, and methyl methacrylate, 17.5 g, in a
conical flask in advance to dissolve. This mixture was added
to the above-mentioned separating flask and reacted for one
hour under nitrogen bubbling. The reaction was maintained
for 5 hours at 65~C, after which the reaction was finished.
The solid matter produced was filtered after cooling, washed
and dried under reduced pressure. A bead-like dispersing
agent (1) was obtained.
* Trade mark
19
, . . . . ~ ~

i340.~01~
, . . .
Composition Example 2
A bead-like dispersing agent (2) was obtained by
operating in the same way as in Example 1, except that a
mixture of lauryl acrylate and tridecyl acrylate, 25.0 g,
methacrylic acid, 5.0 g, dimethylaminoethyl methacrylate,
5.0 g, and methyl methacrylate, 17.5 g, was used.
Composition Example 3
A bead-like dispersing agent (3) was obtained by
operating in the same way as in Example 1, except that
stearyl methacrylate, 30 g, dimethylaminopropyl
methacrylamide, lO.0 g, and methyl methacrylate, lO.0 g, was
used.
The examples of water absorbent polymer will be given
hereinafter.
Example 1
N-hexane, 360.7 g, and the dispersing agent (1), 4.32 g,
were fed in to a 1 L separating flask equipped with an
agitator, a reflux condenser, a dropping funnel, a
thermometer and a nitrogen gas introduction tube. The
temperature was raised to 50~C to disperse and dissolve the
materials and the atmosphere was replaced with N2.

13~0501~
Acrylic acid, 72.0 g, was partially neutralized by means
of sodium hydroxide, 32.2 g, dissolved in ion exchange
purified water, 103.6 g, in a conical flask in advance and
potassium persulfate, 0.24 g, was dissolved therein at room
S temperature. This monomer aqueous solution was added to the
above-described separating flask under nitrogen bubbling at
an agitation speed of 300 rpm for an hour. After reflux for
two hours, 30% aqueous hydrogen peroxide, 0.1 g, was added
thereto and polymerization was completed by continuing reflux
for an hour. Thereafter, ethylene glycol diglycidyl ether,
0.73 g, was added thereto, azeotropic distillation was
performed and drying under reduced pressure after filtration
was effected and a white bead-like polymer was obtained.
There was little attachment of the polymer particles in the
separating flask.
The obtained dry polymer showed a water absorbency to
ion exchange purified water of 125 (g/g), the water absorb-
ency to 0.9% salt water was 33 (g/g), the particle size in
dry condition was 120 ~m and the particle size when water was
absorbed was 480 ~m. The particle independence when
water was absorbed was maintained.
Examples 2 and 3
A white bead-like polymer was obtained by operating in
the same way as in Example 1 except that the dispersing
21
. .

13~0~00
agents (2), (3) obtained in the composition Examples 2, 3 in-
stead of the dispersing agent (1) of Example 1 were used.
There was little attachment of polymer in the separating
flask.
Example 4
A white bead-like polymer was obtained by operating in
the same way as in Example 1 except that cyclohexane instead
of the n-hexane of the Example 1 was used. There was little
attachment of polymer in the separating flask.
Examples 5-6
A white bead-like polymer was obtained by operating in
the same way as in Example 1 except that the ethylene glycol
diglycidyl ether, 0.73 g, of Example 1 was added at 0.18 g
and 1.46 g. There was little attachment of polymer in the
separating flask.
Comparison Example 1
A white bead-like polymer was obtained by operating in
the same way as in Example 1 except that the ethylene glycol
diglycidyl ether of Example 1 was not added. There was
little attachment of polymer in the separating flask.
Comparison Example 2
A white powdery polymer was obtained by operating in the
22

13~0.50~
same way as in example 1 but by using sorbitan monolaurate
instead of the dispersing agent (1) of Example 1. The
attachment of polymer to the wall surface and the agitating
blade in the separating flask was observed.
Comparison Example 3
A commercially available product, AQUALIC CA-W
(made by NIHON SHOKUBAI KAGAKU KOGYO KABUSHIKI KAIS~A)
was evaluated in Examples l through 6 and Comparison Examples
1 through 3 and the results are shown in Fig. 2.
Examples of the production methods for fine grain ice
and concrete/mortar wlll be given hereinafter.
Example A (Fine Grain Ice)
Drinking water, 100 kg, was fed into a 100 L vessel
equipped with an agitator and the water absorbent polymer,
1.0 kg, of Example 1 was gradually added thereto with
agitation. After the water was absorbed, agitation was
stopped and the fine grain polymer which absorbed the water
was subjected to freezing. Then, the frozen polymer formed
independent fine grain ice by a simple mechanical operation
and was agitated by a mixer with sand and cement in the
following proportions to form mortar:
* Trade mark
23
... _ _ . . .......... . ... . . .

1340~00
cement : fine grain ice : quartz sand (dry)
=100 : 28 : 20
This mortar was formed into a plate which was 50 mm wide
and 12 mm thick by a vacuum deaeration type extrusion molding
machine. Five specimens which were 350 mm long were made by
using this plate. A bending tension test was performed after
curing at room temperature for 14 days. The bending tension
strength (kg/cm2) were 185.3, 211.1, 237.2, 191.0 and 177.9
and the average was 200.5 kg/cm2.
Example B (Fine Grain Ice)
After water was absorbed, a powder mixture was prepared
in the following ratio by using frozen fine grain polymer
produced by the same method as in Example A.
cement : fine grain ice : quartz sand (dry)
= 100 : 24 : 20
Thereafter, a plate which was 50 mm wide and 12 mm thick was
formed by means of a vacuum deaeration type extrusion molding
machine. The bending tension strength (kg/cm2) of this plate
which was cured for 14 days at 20~C in a room was 249.5,
220.1 and 220.3 and the average was 230.0 kg/cm2.
Example C (Fine Grain Ice)
After water was absorbed, a powdery mixture was prepared
24

1~40500
in the following ratio by using the frozen fine grain polymer
produced in the same manner as in Example A to form a plate
by a means of vacuum deaeration type extrusion molding
machine.
cement : fine grain ice : quartz sand (dry)
= 100 : 32 : 20
The bending tension strength (kg/cm2) of this plate after
curing at 20~C in a room for 14 days was 176.8, 157.0 and
146.1 and the average was 160.0 kg/cm2.
Example D (Dry Clathrate Water)
Drinking water, 50 kg, was fed into a 100 L vessel
equipped with an agitator, and water absorbing polymer, 1.0
kg, was gradually added thereto with agitation. After the
water was absorbed, agitation was stopped to manufacture dry
clathrate water. By using this dry clathrate water,
agitation was performed by means of a mixer with sand and
cement in the following proportions to manufacture mortar.
cement : dry clathrate water : quartz sand (dry)
= 100 : 28 : 20
The bending test result of the plate manufactured and cured
in the same manner as in Example A by using this mortar was
218.4, 179.5 and 180.9 and the average was 192.9 kg/cm2.

l~OSO~
Example E (Dry Clathrate Water)
The same method as in Example D was performed.
The bending test result of the resultant plate from the
following ratio was 241.5, 216.8 and 206.3 and the average
5 was 221.5 kg/cm2.
cement: dry clathrate water: quartz sand (dry)
= 100: 24: 20
10 Example F (Dry Clathrate Water)
The same method as in Example D was performed.
The bending test result of the resultant plate from the
following ratio was 166.3, 147.0 and 146.1 and the average
was 153.1 kg/cm2.
cement: dry clathrate water: quartz sand (dry)
= 100: 32: 20.
26

Representative Drawing

Sorry, the representative drawing for patent document number 1340500 was not found.

Administrative Status

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Event History

Description Date
Time Limit for Reversal Expired 2010-04-13
Letter Sent 2009-04-14
Inactive: CPC assigned 1999-04-19
Inactive: IPC removed 1999-04-19
Inactive: IPC assigned 1999-04-19
Inactive: IPC assigned 1999-04-15
Inactive: IPC assigned 1999-04-15
Inactive: CPC assigned 1999-04-15
Inactive: CPC assigned 1999-04-15
Inactive: IPC assigned 1999-04-15
Inactive: Inventor deleted 1999-04-15
Inactive: Inventor deleted 1999-04-15
Inactive: IPC assigned 1999-04-15
Inactive: First IPC assigned 1999-04-15
Grant by Issuance 1999-04-13

Abandonment History

There is no abandonment history.

Fee History

Fee Type Anniversary Year Due Date Paid Date
MF (category 1, 2nd anniv.) - standard 2001-04-13 2001-02-06
MF (category 1, 3rd anniv.) - standard 2002-04-15 2002-02-21
MF (category 1, 4th anniv.) - standard 2003-04-14 2003-02-12
MF (category 1, 5th anniv.) - standard 2004-04-13 2004-02-23
MF (category 1, 6th anniv.) - standard 2005-04-13 2005-03-02
MF (category 1, 7th anniv.) - standard 2006-04-13 2006-02-08
MF (category 1, 8th anniv.) - standard 2007-04-13 2007-03-06
MF (category 1, 9th anniv.) - standard 2008-04-14 2008-02-08
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
OOSAKA YUUKI KAGAKU KOGYO KABUSHIKI KAISHA
Past Owners on Record
CHUZO KATO
TAIJI KANBAYASHI
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Claims 1999-04-27 6 181
Cover Page 1999-04-27 1 17
Abstract 1999-04-27 1 25
Drawings 1999-04-27 2 58
Descriptions 1999-04-27 28 916
Maintenance Fee Notice 2009-05-26 1 171
Prosecution correspondence 1997-12-05 2 37
Examiner Requisition 1997-06-06 2 70
Prosecution correspondence 1995-02-20 4 134
Examiner Requisition 1994-10-28 2 91
PCT Correspondence 1993-11-18 1 34
Prosecution correspondence 1994-07-29 1 32
PCT Correspondence 1998-11-06 1 27
PCT Correspondence 1999-01-22 1 36
Courtesy - Office Letter 1993-10-04 1 18
Courtesy - Office Letter 1994-02-11 1 25