U.S. patent application number 09/749619 was filed with the patent office on 2002-01-10 for anti-shrinkage agent for hydraulic material.
This patent application is currently assigned to Nippon Shokubai Co., Ltd.. Invention is credited to Hirata, Tsuyoshi, Nagare, Koichiro.
Application Number | 20020004559 09/749619 |
Document ID | / |
Family ID | 18505461 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020004559 |
Kind Code |
A1 |
Hirata, Tsuyoshi ; et
al. |
January 10, 2002 |
Anti-shrinkage agent for hydraulic material
Abstract
The present invention is related to a shrinkage reducing agent
for hydraulic materials which comprises at least one polymer
selected from the group consisting of (a) a polymer having a
structure derived from the residue of a compound containing 2 to 30
carbon atoms and one active hydrogen atom by the binding thereto of
one oxyalkylene chain having a carboxyl-containing side chain, (b)
a polymer having a structure derived from the residue of a compound
containing 4 to 30 carbon atoms and two active hydrogen atoms by
the binding thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain, (c) a polymer having a structure
derived from the residue of a compound containing 1 to 30 carbon
atoms and at least three active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain and (d) a polymer having a structure
derived from the residue of an amine by the binding thereto one
oxyalkylene chain having a carboxyl-containing side chain.
Inventors: |
Hirata, Tsuyoshi; (Kobe-shi,
JP) ; Nagare, Koichiro; (Kawasaki-shi, JP) |
Correspondence
Address: |
Pollock, Vande Sande & Amernick, R.L.L.P.
Suite 800
1990 M Street, N.W.
Washington
DC
20036-3425
US
|
Assignee: |
Nippon Shokubai Co., Ltd.
1-1, Koraibashi 4-chome Chuo-ku, Osaka-shi
Osaka
JP
541-0043
|
Family ID: |
18505461 |
Appl. No.: |
09/749619 |
Filed: |
December 28, 2000 |
Current U.S.
Class: |
525/187 ;
526/320; 526/329.6 |
Current CPC
Class: |
C04B 2111/34 20130101;
C04B 24/267 20130101; C04B 24/2694 20130101; C04B 24/2647
20130101 |
Class at
Publication: |
525/187 ;
526/320; 526/329.6 |
International
Class: |
C08L 071/02; C08F
222/10; C08K 005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 1999 |
JP |
11-375398 |
Claims
1. A composition for using as a shrinkage reducing agent for
hydraulic materials which comprises at least one polymer selected
from the group consisting of (a) a polymer having a structure
derived from the residue of a compound containing 2 to 30 carbon
atoms and one active hydrogen atom by the binding thereto of one
oxyalkylene chain having a carboxyl-containing side chain, (b) a
polymer having a structure derived from the residue of a compound
containing 4 to 30 carbon atoms and two active hydrogen atoms by
the binding thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain, (c) a polymer having a structure
derived from the residue of a compound containing 1 to 30 carbon
atoms and at least three active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain and (d) a polymer having a structure
derived from the residue of an amine by the binding thereto one
oxyalkylene chain having a carboxyl-containing side chain.
2. The composition for using as a shrinkage reducing agent for
hydraulic materials according to claim 1, wherein said oxyalkylene
chain having a carboxyl-containing side chain has a repeating unit
represented by the general formula (1): 2wherein R.sup.1 and
R.sup.2 are the same or different and each represents a hydrogen
atom, a hydrocarbon group containing 1 to 18 carbon atoms or a
carboxyl-containing side chain, Z.sup.1 and Z.sup.2 are the same or
different and each represents a hydrogen atom or a
carboxyl-containing side chain, provided that the
carboxyl-containing side chain has a structure resulting from
polymerization of an ethylenically unsaturated monomer component
comprising an unsaturated carboxylic acid monomer, said repeating
unit comprising a repeating unit having a carboxyl-containing side
chain.
3. The composition for using as a shrinkage reducing agent for
hydraulic materials according to claim 2, wherein said
ethylenically unsaturated monomer component comprises an
.alpha.,.beta.-unsaturated dicarboxylic acid monomer and
(meth)acrylic acid.
4. A method of producing a composition for using as a shrinkage
reducing agent for hydraulic materials according to claim 1, which
comprises a step of producing a polymer by graft polymerization of
an ethylenically unsaturated monomer component onto a polyether
compound, said ethylenically unsaturated monomer component
comprising an unsaturated carboxylic acid monomer.
5. The method of producing a composition for using as a shrinkage
reducing agent for hydraulic materials according to claim 4,
wherein the polyether compound comprises at least one member
selected from the group consisting of alkylene oxide adducts of a
compound containing 2 to 30 carbon atoms and one active hydrogen
atom, alkylene oxide adducts of a compound containing 4 to 30
carbon atoms and two active hydrogen atoms, alkylene oxide adducts
of a compound containing 1 to 30 carbon atoms and at least three
active hydrogen atoms and alkylene oxide adducts of an amine.
6. An additive composition for hydraulic materials comprising a
shrinkage reducing agent for hydraulic materials and a cement
dispersing agent, wherein said shrinkage reducing agent for
hydraulic materials comprises at least one polymer selected from
the group consisting of (A) a polymer having a structure derived
from the residue of a compound containing 1 to 30 carbon atoms and
one active hydrogen atom by the binding thereto of one oxyalkylene
chain having a carboxyl-containing side chain, (B) a polymer having
a structure derived from the residue of a compound containing 1 to
30 carbon atoms and two active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain, (C) a polymer having a structure
derived from the residue of a compound containing 1 to 30 carbon
atoms and at least three active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain and (D) a polymer having a structure
derived from the residue of an amine by the binding thereto one
oxyalkylene chain having a carboxyl-containing side chain.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a shrinkage reducing agent
for hydraulic materials, a method of producing the same and an
additive composition for hydraulic materials.
PRIOR ART
[0002] Hydraulic materials can give cured products excellent in
strength and durability, among others, and therefore are in wide
use in the form of cement compositions such as cement pastes,
mortar and concrete. They are now indispensable in building civil
engineering and architectural structures. Such hydraulic materials,
however, have a problem. After curing, the unreacted water
remaining in the inside disperses according to ambient temperature,
moisture and other conditions and drying shrinkage progresses
presumably due to such moisture dissipation to cause cracks to
appear in cured products, lowering the strength and durability
thereof. Decreases in strength and durability of civil engineering
and architectural structures produce serious problems such as
endangered safety and increased repairing costs.
[0003] The government regulations with respect to these problems
are going to be tightened. For instance, the Japanese law
concerning the promotion of assurance of the quality of houses as
enacted in June, 1999 includes concrete cracking among the defects
to be repaired. Further, in Japan, there is the possibility of
specifications, with respect to cracking due to drying shrinkage,
for performance-oriented ready mixed concrete being introduced into
JIS A 5308 in or after 2005. Under the circumstances, the
importance of shrinkage reducing agents for hydraulic materials
which prevent the progress of shrinkage due to drying of cured
hydraulic materials has been well recognized and various
technological innovations have been made.
[0004] Thus, the following agents have been disclosed for reducing
the shrinkage of cement mixes upon drying: C.sub.1-4
alcohol-alkylene oxide adducts (Japanese Kokoku Publication
Sho-56-51148), dihydric to octahydric alcohol-ethylene oxide and
propylene oxide coadducts (Japanese Kokoku Publication
Hei-01-53214), lower alkylamine-alkylene oxide adducts (Japanese
Kokoku Publication Hei-01-35215), polypropylene glycol species in
the range of oligomers (Japanese Kokai Publication Sho-59-152253),
low-molecular-weight alcohols (Japanese Kokoku Publication
Hei-06-650) and C.sub.8 2-ethylhexanol-alkyleneoxide adducts
(JP2825855), among others. All these compounds are oligomers or
low-molecular compounds with a molecular weight of not more than
about 1,000.
[0005] Among them, those shrinkage reducing agents which have been
put into practice use and are commercially available are reviewed,
for example, in "Konkurito Konwazai no Kaihatsu to Saishin Gijutu
(Development and State-of-the-art Technologies of Concrete
Admixtures)" (first edition, published Sep. 18, 1995 by CMC Co.).
However, the standard addition amounts of these shrinkage reducing
agents are as high as 2 to 6% on the unit cement content basis, so
that when used in concrete, they increase the cost of concrete and
can never be said to be general purpose agents.
[0006] Meanwhile, as regards high-molecular-weight agents for
reducing shrinkage due to drying, Japanese Kokai Publication
Hei-08-268741 discloses a cement dispersing agent of the drying
shrinkage reducing type which comprises a graft polymer derived
from a polycarboxylic acid (or a salt thereof) by the chemical
bonding of anoligoalkylene glycol or polyhydric alcohol to side
chains thereof. However, this is not easy to synthesize.
[0007] For obtaining high-molecular-weight compounds with ease,
there are known methods which comprise graft polymerizing an
ethylenically unsaturated monomer onto a polyether compound.
Laid-open European Patent Application No. 0271435 (A2) discloses
the use of a graft polymer constituted of a main chain polyether
polymer and a side chain polymer resulting from polymerization of
an unsaturated ethylenic monomer as a superplasticizer or water
reducing agent for cement compositions and Japanese Kokai
Publication Hei-11-139855 discloses the use, as a cement additive,
of a graft polymer comprising a specific monomer and having a
weight average molecular weight of not less than 6,000. However,
these graft polymers are intended to improve the strength and other
properties of cured cement products by reducing water and curing
cement compositions while maintaining the flowability thereof.
Nothing is disclosed at all therein of the use thereof as agents
for reducing drying shrinkage. Therefore, there was a room for
studying in order to readily produce agents capable of
satisfactorily suppressing the progress of shrinkage due to drying
even when the addition amount thereof in hydraulic materials is
reduced.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the present invention, which
has been made in view of the state of the art mentioned above, to
provide a shrinkage reducing agent for hydraulic materials high in
general versality and capable of producing a better cracking
preventing effect by sufficiently preventing the progress of drying
shrinkage of cured products even when the addition amount thereof
in hydraulic materials is reduced to thereby cut down the cost of
production of hydraulic materials, a method of producing the same,
and an additive composition for hydraulic materials.
[0009] The present inventors made intensive investigations
following careful studying of the problems concerning the shrinkage
reducing agents for hydraulic materials which could be used widely
in the fields of civil engineering and architecture and, as a
result, encountered the fact that a shrinkage reducing agent for
hydraulic materials which comprises a polymer having a specific
structure can produce an excellent cracking preventing effect by
sufficiently suppressing the progress of shrinkage due to drying of
cured products even when used at a reduced addition amount to
thereby reduce the production cost of hydraulic materials, hence
can produce a dramatic effect, increasing the general versatility,
improving the safety of civil engineering and architectural
structures and suppressing the repairing costs, and have now
completed the present invention.
[0010] Thus, the present invention lies in a shrinkage reducing
agent for hydraulic materials
[0011] which comprises at least one polymer selected from the group
consisting of
[0012] (a) a polymer having a structure derived from the residue of
a compound containing 2 to 30 carbon atoms and one active hydrogen
atom by the binding thereto of one oxyalkylene chain having a
carboxyl-containing side chain,
[0013] (b) a polymer having a structure derived from the residue of
a compound containing 4 to 30 carbon atoms and two active hydrogen
atoms by the binding thereto of at least one oxyalkylene chain
having a carboxyl-containing side chain,
[0014] (c) a polymer having a structure derived from the residue of
a compound containing 1 to 30 carbon atoms and at least three
active hydrogen atoms by the binding thereto of at least one
oxyalkylene chain having a carboxyl-containing side chain
[0015] and (d) a polymer having a structure derived from the
residue of an amine by the binding thereto one oxyalkylene chain
having a carboxyl-containing side chain.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In the following, the invention is described in detail.
[0017] The shrinkage reducing agent of the invention for hydraulic
materials comprises at least one polymer selected from the group
consisting of the above-mentioned polymer (a), polymer (b), polymer
(c) and polymer (d). Although it may contain another component or
other components, it preferably comprises the above-mentioned
polymer(s) as a main component(s) These polymers may be used singly
or two or more of them may be used in combination. When two or more
polymers are used, the weight proportions of the respective
polymers are not particularly restricted.
[0018] Referring to the above polymers (a), (b) and (c), the term
"residue of a compound containing an active hydrogen atom(s)" means
a group having a structure resulting from removal of the active
hydrogen atom(s) from the active hydrogen-containing compound. The
group(s) formed upon reaction with the active hydrogen-containing
compound is(are) not particularly restricted. Preferred as such
group(s), alcohol residues having a structure resulting from
removal of an active hydrogen atom(s) from the hydroxy group(s) of
alcohols. Further, there may be mentioned, among others, carboxylic
acid residues having a structure resulting from removal of an
active hydrogen atom(s) from the carboxyl group(s) of carboxylic
acids. As the active hydrogen-containing compound, there may be
mentioned compounds having one, two or three active hydrogen atoms.
Referring to the above polymer (d), the "amine residue" means a
group having a structure resulting from the removal of a hydrogen
atom(s) from a substituent(s) on the nitrogen atom of the amine or
a group having a structure resulting from the removal of a hydrogen
atom(s) on the nitrogen atom of ammonia or the amine, without being
particularly limited to the groups formed upon reaction with
ammonia or the amine.
[0019] Referring to the above polymers, the oxyalkylene chain
having a carboxyl-containing side chain is not particularly
restricted but may comprise one single species or two or more
species. Preferred are, for example, structures having a repeating
unit represented by the general formula (1): 1
[0020] wherein R.sup.1 and R.sup.2 are the same or different and
each represents a hydrogen atom or a hydrocarbon group containing 1
to 18 carbon atoms or a carboxyl-containing side chain and Z.sup.1
and Z.sup.2 are the same or different and each represents a
hydrogen atom or a carboxyl-containing side chain. It is essential,
however, that the above repeating unit comprise a
carboxyl-containing side chain. It is preferred that such repeating
unit be a main component of the oxyalkylene chain. The chain may
also comprise another or other repeating units. It is preferred
that one of R.sup.1 and R.sup.2 be a hydrogen atom and the other be
a hydrogen atom or a hydrocarbon group containing 1 to 18 carbon
atoms.
[0021] The above polymers comprise a structure resulting from the
binding of an oxyalkylene chain to the residue of an active
hydrogen-containing compound containing a specified number of
carbon atoms and/or the amine residue and a carboxyl-containing
side chain or chains. The side chains have a structure resulting
from polymerization of an ethylenically unsaturated monomer
component(s) comprising an unsaturated carboxylic acid monomer as
an essential component. Such polymers can be produced by a step of
producing polymers by graft polymerization of an ethylenically
unsaturated monomer(s) comprising an unsaturated carboxylic acid
monomer as an essential component onto polyether compounds, as
mentioned later herein. The polymers obtained by graft
polymerization of an unsaturated carboxylic acid monomer(s) onto
polyether compounds have a carboxyl group(s) on their side chains
and it is considered that the polymers be adsorbed on hydraulic
materials through the ionic force owing to such a carboxyl group,
although the force is weak, or that they chelate the cations on the
surface of hydraulic materials or the cations eluted. Although the
principle on which such a carboxyl group functions and contributes
to shrinkage reduction in cured hydraulic material products is not
uncertain, the action sufficiently suppressing the progress of
drying shrinkage of cured products (hereinafter referred to as
"shrinkage reducing ability") is surprisingly improved remarkably
when the above ethylenically unsaturated monomer component
comprises an unsaturated carboxylic acid monomer as an essential
component.
[0022] The hydrophilicity and hydrophobicity of the above polymers
are not particularly restricted so long as the effects of the
present invention are produced. However, when the hydrophobicity is
excessive, the amount of air in concrete may be reduced to an
excessive extent, hence the adjustment of the amount of air may
become difficult. When the hydrophilicity is excessive, an
excessive amount of air may be entrained, so that it may possibly
become difficult as well to adjust the amount of air to an
appropriate level. The hydrophilicity and hydrophobicity of the
above polymers can be adjusted, for example, by selecting an
appropriate oxyalkylene chain structure.
[0023] While the above polymers are not particularly restricted in
weight average molecular weight (Mw), a weight average molecular
weight of 200 to 1,000,000 as determined by gel permeation
chromatography (hereinafter referred to as "GPC"), for instance, is
preferred. More preferably, it is 500 to 500,000, still more
preferably 1,000 to 100,000. The molecular weight distribution
(Mw/Mn) is not particularly restricted but is preferably 1.5 to
100, for instance, more preferably 2 to 80, still more preferably 3
to 50. The molecular weight distribution of the polymers is the
value obtained by dividing the weight average molecular weight (Mw)
by the number average molecular weight (Mn).
[0024] In the present specification, the term "molecular weight"
means the value determined by gel permeation chromatography (GPC),
for instance. In the gel permeation chromatography (GPC), it is
preferred that the working curve constructed by using commercially
available polyethylene glycols as standard samples can be
approximated by an expression of the third order at least within
the range of 1,000 to 100,000 and that the correlation coefficient
(r) of the approximation equation be not less than 0.99, more
preferably not less than 0.999, still more preferably not less than
0.9999. The mobile phase is selected so that it can dissolve the
sample. For accurate molecular weight determination, the working
curve is preferably constructed by using a largest possible number
of standard samples and, for that purpose, 5 or more standard
samples should be used. On that occasion, one point for each of a
molecular weight not more than 1,500 and a molecular weight not
less than 150,000 should be included so that the reliability of the
molecular weight determined can be guaranteed.
[0025] The invention is also directed to a method of producing the
above-mentioned shrinkage reducing agent for hydraulic materials
which comprises the step of producing a polymer by graft
polymerization of an ethylenically unsaturated monomer component
comprising an unsaturated carboxylic acid monomer as an essential
component onto a polyether compound. By this method, it becomes
possible to produce, in a simple and easy manner, those shrinkage
reducing agents for hydraulic materials which produce the effects
of the present invention.
[0026] In the following, referring to the method of producing the
shrinkage reducing agents for hydraulic materials according to the
invention, the ethylenically unsaturated monomer component,
polyether compound and polymer production method are described in
detail.
[Ethylenically unsaturated monomer component]
[0027] The unsaturated carboxylic acid monomer in the ethylenically
unsaturated monomer component has at least one polymerizable
unsaturated bond and at least one carboxyl group and preferably
comprises an unsaturated monocarboxylic acid monomer and an
.alpha.,.beta.-unsaturated dicarboxylic acid monomer and/or the
anhydride thereof as essential components. They may each comprise a
single component or a combination of two or more components. By
using the .alpha.,.beta.-unsaturated dicarboxylic acid monomer
and/or the anhydride thereof, that rapid viscosity increase due to
the uncontrolled progress of the polymerization reaction can be
prevented. The content of the unsaturated carboxylic acid monomer
in the ethylenically unsaturated monomer component is not
particularly restricted so long as the effects of the present
invention are produced. It is preferred that said monomer be
contained as a main component, with or without another or other
components.
[0028] As the unsaturated monocarboxylic acid monomer, there may be
mentioned, among others, (meth)acrylic acid, crotonic acid, tiglic
acid, 3-methylcrotonic acid and 2-methyl-2-pentenoic acid. Among
them, (meth)acrylic acid is preferred because of its ready
availability.
[0029] As the .alpha.,.beta.-unsaturated dicarboxylic acid monomer
and/or the anhydride thereof, there may be mentioned, among others,
.alpha.,.beta.-unsaturated dicarboxylic acids such as maleic acid,
fumaric acid, mesaconic acid and citraconic acid;
.alpha.,.beta.-unsatura- ted dicarboxylic acid anhydrides such as
maleic anhydride and citraconic anhydride. Among them, at least one
compound selected from the group consisting of maleic acid, fumaric
acid and maleic anhydride is preferred from the ready availability
viewpoint.
[0030] For effecting the graft polymerization onto a polyether
compound at an appropriate rate while preventing the viscosity from
increasing, for instance, the content of the
.alpha.,.beta.-unsaturated dicarboxylic acid monomer and/or the
anhydride thereof in the unsaturated carboxylic acid monomer is
preferably 0.1 to 99.9% by weight, more preferably 1 to 99% by
weight, still more preferably 10 to 90% by weight, most preferably
20 to 80% by weight.
[0031] In a preferred mode of practice of the invention, the
ethylenically unsaturated monomer component comprises an
.alpha.,.beta.-unsaturated dicarboxylic acid monomer and (meth)
acrylic acid. In such a mode of practice, the weight ratio between
the .alpha.,.beta.-unsaturated dicarboxylic acid monomer and
(meth)acrylic acid is preferably 1/99 to 99/1, more preferably
10/90 to 90/10, still more preferably 20/80 to 80/20, most
preferably 30/70 to 70/30.
[0032] As the ethylenically unsaturated monomer other than the
unsaturated carboxylic acid monomer capable of being included in
the ethylenically unsaturated monomer component, there may be
mentioned ethylenically unsaturated carboxylic acid esters and
other ethylenically unsaturated monomers. These may be used singly
or a plurality thereof may be used.
[0033] As the ethylenically unsaturated carboxylic acid esters,
there may be mentioned, among others, maleic acid alkyl esters such
as monomethyl maleate, dimethyl maleate, monoethyl maleate and
diethyl maleate; fumaric acid alkyl esters such as monomethyl
fumarate, dimethyl fumarate, monoethyl fumarate and diethyl
fumarate; alkyl (meth)acrylates such as methyl (meth)acrylate,
ethyl (meth)acrylate, butyl (meth)acrylate and stearyl
(meth)acrylate; hydroxy-containing unsaturated carboxylic acid
esters, for example hydroxyalkyl (meth)acrylates such as
hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; and
polyalkylene glycol (meth)acrylates such as (methoxy)polyethylene
glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate,
naphthoxypolyethylene glycol (meth)acrylate,
monophenoxypolyethylene glycol maleate and carbazolepolyethylene
glycol (meth)acrylate.
[0034] As the ethylenically unsaturated monomers other than the
above ethylenically unsaturated carboxylic acid esters, there may
be mentioned, among others, the following.
[0035] Aromatic vinyl monomers such as styrene; amido-containing
vinyl monomers such as (meth)acrylamide and (meth)acrylalkylamides;
vinyl esters such as vinyl acetate, vinyl propionate, vinyl
pivalate, vinyl benzoate and vinyl cinnamate; alkenes such as
ethylene and propylene; dienes such as butadiene and isoprene;
trialkyloxysilyl-containing vinyl monomers such as
vinyltrimethoxysilane and vinyltriethoxysilane; silicon-containing
vinyl monomers such as .gamma.-(methacryloyloxypropyl)-
trimethoxysilane; maleimide derivatives such as maleimide,
methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide,
octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide
and cyclohexylmaleimide;
[0036] nitrile group-containing vinyl monomers such as (meth)
acrylonitrile; aldehyde group-containing vinyl monomers such as
(meth)acrolein; amino-containing vinyl monomers, for example
dialkylaminoethyl (meth)acrylates such as dimethylaminoethyl
(meth)acrylate; unsaturated ethers such as (methoxy)polyethylene
glycol (meth)allyl ether and (methoxy)polyethylene glycol
isopropenyl ether; sulfo-containing vinyl monomers such as
2-acrylamido-2-methylpropanesulfo- nic acid, (meth)allylsulfonic
acid, 2-sulfoethyl (meth)acrylate, vinylsulfonic acid,
hydroxyallyloxypropanesulfonic acid and styrenesulfonic acid; and
other functional group-containing vinyl monomers such as vinyl
chloride, vinylidene chloride, allyl chloride, allyl alcohol,
vinylpyrrolidone and ethyl vinyl ether.
[Polyether compound]
[0037] The polyether compound preferably comprises at least one
member selected from the group consisting of alkylene oxide adducts
of a compound containing 2 to 30 carbon atoms and one active
hydrogen atom, alkylene oxide adducts of a compound containing 4 to
30 carbon atoms and two active hydrogen atoms, alkylene oxide
adducts of a compound containing 1 to 30 carbon atoms and at least
three active hydrogen atoms and alkylene oxide adducts of an amine,
among others. Although it may further comprise another or other
constituents, it preferably comprises such an alkylene oxide adduct
or adducts as main constituents. The alkylene oxide adducts may be
used singly or two or more of them may be used combinedly.
[0038] The above-mentioned alkylene oxide adducts can be prepared,
for example, by polymerization, by a method known in the art, of an
alkylene oxide onto an active hydrogen-containing compound and have
a structure such that one oxyalkylene chain is bound to the residue
of a compound containing 2 to 30 carbon atoms and one active
hydrogen atom, a structure such that at least one oxyalkylene chain
is bound to a residue of a compound containing 4 to 30 carbon atoms
and two active hydrogen atoms, a structure such that at least one
oxyalkylene chain is bound to a residue of a compound containing 1
to 30 carbon atoms and three or more active hydrogen atoms, or a
structure such that one oxyalkylene chain is bound to an amine
residue. That terminus of each oxyalkylene chain not bound to the
residue of an active hydrogen-containing compound or to an amine
residue has a structure such that it is bound to a hydrogen atom, a
monovalent metal atom, a divalent metal atom, an ammonium group, an
organic amine group, a hydrocarbon group containing 1 to 30 carbon
atoms, an oxo-hydrocarbon group, an amido-hydrocarbon group, a
carboxyl hydrocarbon group, a sulfonyl (hydrocarbon) group
containing 0 to 30 carbon atoms or the like. When there are two or
more oxyalkylene chains in each molecular, they may have the same
terminal structure or different terminal structures. Among these
terminal structures, the structure bound to a hydrogen atom or a
hydrocarbon group containing 1 to 30 carbon atoms is preferred from
the general versatility viewpoint.
[0039] As the alkylene oxide, there may be mentioned, for example,
ethylene oxide, propylene oxide, butylene oxide and styrene oxide.
Among them, the use of ethylene oxide and/or propylene oxide,
together with another alkylene oxide, as necessary, is preferred
from the general versatility viewpoint. These may be used singly or
two or more of them may be used to realize an addition mode such as
block addition, alternate addition or random addition, for
instance.
[0040] The active hydrogen-containing compound preferably comprises
at least one species selected from the group consisting of
monohydric alcohols containing 2 to 30 carbon atoms, dihydric
alcohols containing 4 to 30 carbon atoms, tri- and polyhydric
alcohols containing 1 to 30 carbon atoms and amines and may contain
a carboxylic acid or the like as necessary. These may be used
singly or two or more of them may be used combinedly. Among them,
those alcohols which are relatively inexpensive and readily
available are preferred from the general versatility viewpoint, and
monohydric alcohols containing 2 to 30 carbon atoms are more
preferred.
[0041] The above monohydric alcohols containing 2 to 30 carbon
atoms include, among others, C.sub.2-22 primary alcohols such as
ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol,
2-ethylbutanol, n-octanol, 1-dodecanol, 1-octadecanol,
2-ethylhexanol, cyclohexanol, allyl alcohol and
3-methyl-3-buten-1-ol; C.sub.3-18 secondary alcohols such as
isopropyl alcohol, 2-butanol, 2-pentanol, 3-pentanol, 2-heptanol,
3-hepatanol, methylamyl alcohol, 2-ocatnol, nonyl alcohol and
C.sub.12-14 alcohols obtained by oxidation of n-paraffins; and
tertiary alcohols such as tert-butanol and tert-pentanol. Among
them, those containing 3 to 12 carbon atoms are preferred and those
containing 3 to 10 carbon atoms are more preferred.
[0042] The C.sub.4-30 dihydric alcohols include, among others,
1,4-butanediol, hexylene glycol and
2,2-diethyl-1,3-propanediol.
[0043] The C.sub.1-30 tri- and polyhydric alcohols include, among
others, glycerol, trimethylolpropane, 1,3,5-pentanetriol,
pentaerythritol, glucose, fructose, sorbitol, gluconic acid,
tartaric acid and polyvinyl alcohol.
[0044] The amines include, but are not particularly restricted to,
ammonia, methylamine, ethylamine, ethylenediamine,
diethylenetriamine, triethylenetetramine, propylamine, butylamine,
2-ethylbutylamine, octylamine, dimethylamine, dipropylamine,
dimethylethanolamine, dibutylamine, trimethylamine, triethylamine,
allylamine, cyclobutylamine, cyclohexylamine, laurylamine, aniline,
diphenylamine, urea, thiourea and polyethylenimine, among
others.
[0045] The carboxylic acids include, among others, monocarboxylic
acids such as valeric acid, caproic acid, enanthic acid, caprylic
acid, lauric acid, stearic acid, oleic acid, elaidic acid and
erucic acid; dicarboxylic acids such as malonic acid, succinic
acid, glutaric acid and adipic acid; and hydroxycarboxylic acids
such as lactic acid, tartaric acid, citric acid and malic acid.
[0046] The method of polymerization in preparing the alkylene oxide
adducts is not particularly restricted but the use of a
conventional method of polymerization, among others, is preferred
from the general versatility viewpoint, and the method using an
acid catalyst or an alkali catalyst is preferred. As the acid
catalyst, for instance, there may be mentioned metal and semimetal
halides, which are Lewis acid catalysts, such as boron trifluoride;
and inorganic acids such as hydrogen chloride, hydrogen bromide and
sulfuric acid and, as the alkali catalyst, there may be mentioned
potassium hydroxide, sodium hydroxide, sodium hydride and the
like.
[0047] The polyether compound mentioned above may be a derivative
from such an alkylene oxide adduct as mentioned above. Such
derivative is not particularly restricted but includes, among
others, terminal group modification products obtained by conversion
of the terminal functional groups of a polyether compound and
crosslinked products obtained by reacting a polyether compound with
a crosslinking agent having a plurality of carboxyl, isocyanate,
amino, halogen or like groups in each molecule.
[0048] As the terminal group modification products mentioned above,
there may be mentioned, for example, the products obtained by
converting all or part of the terminal hydroxy groups of a
polyether compound by (1) esterification with a fatty acid
containing 2 to 22 carbon atoms or a dicarboxylic acid (anhydride),
such as succinic acid, succinic anhydride, maleic acid, maleic
anhydride and adipic acid, (2) alkoxylation using an alkyl halide
in the manner of hydrogen halide eliminating reaction, namely to
alkoxypolyalkylene glycols, or (3) sulfation with a sulfating agent
known in the art, such as chlorosulfonic acid, sulfuric anhydride
and sulfamic acid, namely to polyoxyalkylene sulfates (salts).
[0049] The weight average molecular weight of the above polyether
compound is not particularly restricted but preferably is 100 to
1,000,000, for instance, more preferably 200 to 100,000, still more
preferably 300 to 50,000. The molecular weight distribution thereof
is not particularly restricted, either, but preferably is, for
example, 1 to 100, more preferably 1.1 to 10, still more preferably
1.1 to 3.
[0050] Since the above polyether compound is used as a starting
material for the polymer of the present invention, the balance
between hydrophilicity and hydrophobicity of such polyether
compound strongly influences the balance between hydrophilicity and
hydrophobicity of the resulting polymer. When the hydrophobicity of
the polymer is excessive, the amount of air in concrete is
excessively reduced and accordingly it becomes difficult to control
the amount of air. Conversely, when the hydrophilicity of the
polymer is excessive, an excessive amount of air is entrained in
the hydraulic material and it becomes difficult to adjust the
amount of air to an appropriate level. Therefore, in the practice
of the invention, it is of particular significance to balance the
hydrophilicity of the polyether compound with the hydrophobicity
thereof. As an index indicative of such balance between
hydrophilicity and hydrophobicity, there is the HLB. Several
attempts have been made to express the HLB in a numerical form. In
the practice of the invention, however, the value calculated
according to Davis' formula described in Susumu Tsuji: "Nyuka
Kayoka no Gijutsu (Techiques of Emulsification and
Solubuilization)" (8th edition, published Oct. 30, 1992 by Kogaku
Tosho) is employed.
[0051] The HLB of the above polyether compound is preferably 1 to
15, for instance, more preferably 2 to 12, still more preferably 3
to 9.
[0052] As commercially available species of the polyether compound,
there may be mentioned alcohol-alkylene oxide adducts, for example
Newpoul LB 50HB series (trademark, products of SANYO CHEMICAL),
which are primary alcohol-alkylene oxide adducts, Softanol series
(trademark, products of Nippon Shokubai), which are C.sub.12-14
secondary alcohol-alkylene oxide adducts, and members of Jeffamine
M series (trademark, products of San Techno Chemical), which are
amine-terminated polyethers, among others.
[Method of polymer production]
[0053] The graft polymerization for preparing the polymers of the
present invention is carried out in the manner of addition
polymerization of an ethylenically unsaturated monomer with a
grafting site generated upon abstraction of a hydrogen or halogen
atom from the polyether compound serving as the site of initiation
of polymerization.
[0054] In the above graft polymerization, some molecules of the
polyether compound may have a number of grafting sites and others
may have no grafting site. When a plurality of atoms are abstracted
from one and the same carbon atom, the polyether chain is cleaved
at that site. The polymerization of an ethylenically unsaturated
monomer is terminated by chain transfer, disproportionation or
recombination, among others. In some cases, mutual binding of
molecules of the polyether compound gives the dimer, trimer and so
forth of the polyether compound. Therefore, it is presumable that
the molecular weight distribution of the hydrophilic graft polymer
obtained is broadened, hence the distribution (Mw/Mn)
increases.
[0055] The method to be used in the above graft polymerization is
not particularly restricted provided that the ethylenically
unsaturated monomer can be graft-polymerized onto the polyether
compound. For example, the polymerization is preferably carried out
in the presence of a polymerization initiator since, in this case,
the shrinkage reducing ability of the hydrophilic graft polymer can
be improved by increasing the graft ratio.
[0056] The polymerization initiator is not particularly restricted
but, for example radical initiators known in the art may be used.
From the reactivity viewpoint, among others, organic peroxides are
preferred, however.
[0057] The organic peroxides are not particularly restricted but
include, among others, those mentioned below under (1) to (8).
These may be used singly or two or more of them may be used
combinedly.
[0058] (1) Ketone peroxides: methyl ethyl ketone peroxide,
cyclohexanone peroxide, 3,3,5-trimethylcyclomethyl ethyl ketone
peroxide, 3,3,5-trimethylcyclohexanone peroxide,
methylcyclohexanone peroxide, methyl acetoacetate peroxide,
acetylacetone peroxide, etc.;
[0059] (2) Hydroperoxides: tert-butyl hydroperoxide, cumene
hydroperoxide, diisopropylbenzene hydroperoxide,
2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl
hydroperoxide, 2-(4-methylcyclohexyl)propane hydroperoxide,
etc.;
[0060] (3) Dialkyl peroxides: di-tert-butyl peroxide, tert-butyl
cumyl peroxide, dicymyl peroxide,
.alpha.,.alpha.'-bis(tert-butylperoxy)-p-diis- opropylbenzene,
.alpha.,.alpha.'-bis(tert-butylperoxy)-p-isopropylhexyne,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,
2,5-dimethyl-2,5-di(tert-but- ylperoxy)hexyne-3, etc.;
[0061] (4) Peroxy esters: tert-butyl peroxyacetate, tert-butyl
peroxylaurate, tert-butyl peroxybenzoate, di-tert-butyl
peroxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane,
tert-butylperoxy isopropyl carbonate, tert-butyl peroxyisobutyrate,
tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, cumyl
peroxyneodecanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl
peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxymaleate, cumyl
peroxyoctoate, tert-hexyl peroxypivalate, tert-hexyl
peroxyneohexanoate, cumyl peroxyneohexanoate, etc.;
[0062] (5) Peroxy ketals: n-butyl
4,4-bis(tert-butylperoxy)valerate, 2,2-bis(tert-butylperoxy)butane,
1,1-bis(tert-butylperoxy)-3,3,5-trimethy- lcyclohexane,
1,1-bis(tert-butylperoxy)cyclohexane,
2,2-bis(tert-butylperoxy)butane, etc.;
[0063] (6) Diacyl peroxides: acetyl peroxide, isobutyryl peroxide,
octanoyl peroxide, decanoyl peroxide, lauroyl peroxide,
3,3,5-trimethylcyclohexanoyl peroxide, succinic acid peroxide,
benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide,
etc.;
[0064] (7) Peroxydicarbonates: diisopropyl peroxydicarbonate,
di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate,
bis(4-tert-butylcyclohexyl) peroxydicarbonate, dimyristyl
peroxydicarbonate, di-methoxyisopropyl peroxydicarbonate,
di(3-methyl-3-methoxybutyl) peroxydicarbonate, diallyl
peroxydicarbonate, etc.;
[0065] (8) Other organic peroxides: acetyl cyclohexylsulfonyl
peroxide, tert-butylperoxy allyl carbonate, etc.
[0066] In the above graft polymerization, a catalyst for organic
peroxide decomposition or a reducing compound may be used in
combination with the organic peroxide. In carrying out the graft
polymerization by adding an ethylenically unsaturated monomer
component to the polyether compound, the polymerization initiator
may be added in advance to the polyether compound or may also be
added to the ethylenically unsaturated monomer component or may be
added to the reaction system simultaneously with the ethylenically
unsaturated monomer component.
[0067] The addition amount of the above polymerization initiator is
not particularly restricted but, for example, the initiator is
preferably used in an amount of 0.1 to 15% by weight on the
ethylenically unsaturated monomer component basis. When it is less
than 0.1% by weight or above 15% by weight, the ratio of grafting
on to the polyether compound may possibly decrease. An addition
amount of 0.5 to 10% by weight is more preferred.
[0068] The above graft polymerization can be carried out by any
known method of polymerization, such as solution polymerization or
bulk polymerization. The solvent which can be used in carrying out
solution polymerization is not particularly restricted but, for
example, a solvent which will not adversely affect the efficiency
of polymerization. As such a solvent, there may be mentioned, among
others, water; hydrocarbons such as n-butane, propane, benzene,
cyclohexane and naphthalane; halogenated hydrocarbons such as
methyl chloride, chloroform, carbon tetrachloride and
trichloroethane; alcohols such as propanol, butanol, isopropyl
alcohol, isobutyl alcohol and isoamyl alcohol; ethers such as ethyl
ether, isopropyl ether and butyl ether; ketones such as methyl
ethyl ketone, ethyl butyl ketone and methyl isobutyl ketone; esters
such as methyl acetate, ethyl acetate, ethyl benzoate and ethyl
lactate; acids such as formic acid, acetic acid and propionic acid;
polyhydric alcohol and derivatives thereof such as (poly) ethylene
glycol, ethylene glycol monobutyl ether, ethylene glycol monobutyl
ether acetate, tetraethylene glycol and propylene glycol monobutyl
ether. These may be used singly or two or more of them may be used
combinedly.
[0069] The above graft polymerization may be carried out either
batchwise or continuously. The graft polymerization temperature is
preferably 80 to 160.degree. C. When it is lower than 80.degree.
C., the graft polymerization hardly proceeds and the efficiency of
grafting of the ethylenically unsaturated monomer onto the
polyether compound may decrease. When it is higher than 160.degree.
C., the starting material polyether compound and the graft polymer
obtained may undergo thermal decomposition. A temperature of 100 to
160.degree. C. is more preferred.
[0070] In the above graft polymerization, part or the whole of the
polyether compound is preferably charged at the early stage.
Further, when the ethylenically unsaturated monomer component
comprises an .alpha.,.beta.-unsaturated dicarboxylic acid monomer,
namely at least one monomer selected from the group consisting of
maleic acid, fumaric acid and maleic anhydride or the like, and a
(meth)acrylic acid, the graft polymerization is preferably carried
out by mixing in advance at least the half of the
.alpha.,.beta.-unsaturated dicarboxylic acid monomer with the
polyether compound, heating the mixture to a temperature above the
pour point of the polyether compound and adding the remaining
ethylenically unsaturated monomer and the polymerization initiator
individually to the mixture obtained. In this way, the proportion
of introduction of the .alpha.,.beta.-unsaturated dicarboxylic acid
monomer into the graft polymer can be markedly improved.
[0071] The amount of the ethylenically unsaturated monomer
component is not particularly restricted but, for example, it is
preferred that the ethylenically unsaturated carboxylic acid
monomer contained in the ethylenically unsaturated monomer
component amount to 0.1 to 100 parts by weight per 100 parts by
weight of the polyether compound. When the amount of the
ethylenically unsaturated carboxylic acid monomer is less than 0.1%
by weight, the resulting polymer will hardly act on cement,
possibly resulting in a decrease in shrinkage reducing ability.
When it is in excess of 100 parts by weight, the retardation of
curing by the polymer may be enhanced or the reaction mixture will
acquire an excessively high viscosity and thus become difficult to
handle. A more preferred amount is 1 to 80 parts by weight, still
more preferably 2 to 65 parts by weight.
[0072] The polymer obtained by the above graft polymerization may
be used either as it is or in the form of a solution in a solvent
as a shrinkage reducing agent for hydraulic materials. The solvent
may be, for example, water, an alcohol or the like. The use of
water is preferred, however. When the polymer has an acid group
such as a carboxyl group and a sulfonic acid group or an ester
group derived therefrom, the polymer may be used as an additive
after conversion of part or the whole of the acid group or ester
group to a salt form by addition of a base.
[0073] The base is not particularly restricted but includes, among
others, alkali metal or alkaline earth metal hydroxides such as
sodium hydroxide, potassium hydroxide, calcium hydroxide and
lithium hydroxide; alkali metal or alkaline earth metal carbonates
such as sodium carbonate, calcium carbonate and lithium carbonate;
ammonia, monoethanolamine, diethanolamine, triethanolamine and like
amines. These may be used singly or two or more of them may be used
combinedly.
[0074] The method of graft polymerization is not restricted to the
one mentioned above but the methods described, for example, in JP
2945822, JP 2918798, JP 2918799 and Japanese Kokai Publication
Hei-11-279220 may also be used.
[0075] The shrinkage reducing agent for hydraulic materials
according to the invention is effective in reducing the shrinkage
of hydraulic materials in the process of drying and is used mainly
for the purposes of reducing cracks or preventing cracking,
improving the filling capacity, preventing warpage and preventing
peeling, among others.
[0076] In the following, the characteristics of the shrinkage
reducing agent for hydraulic materials according to the invention
are described.
[0077] In the shrinkage reducing agent for hydraulic materials
according to the invention, the polymer mentioned above has a
carboxyl group(s) and/or a group(s) derived therefrom by
substitution of a cation such as a metal ion or ammonium ion for
the hydrogen atom of the carboxyl group. Among such groups, there
are included those generated by ester hydrolysis, for instance, on
the occasion of addition of the agent into kneading water. Since it
has such groups, the polymer takes the form of a carboxylic acid
and/or a salt thereof.
[0078] The above-mentioned carboxylic acid and/or salt thereof can
be identified by an analytical method known in the art. As such
analytical method, there may be mentioned infrared spectroscopy
(IR), nuclear magnetic resonance spectroscopy (NMR) and
neutralization titration, among others. The carboxylic acid and/or
salt thereof can be qualitatively and quantitatively analyzed by
using these techniques combinedly. In IR, when a carboxylic acid
and/or a salt thereof is present, an absorption band due to
stretching of C.dbd.O of the carboxylic acid appears in the
vicinity of 1700 to 1800 cm.sup.-1. Neutralization titration gives
an acid number, which is a positive number. The acid number is
defined as the number of milligrams of potassium hydroxide required
for neutralizing the carboxylic acid and/or a salt thereof in 1 g
of the sample. In the practice of the invention, the acid number is
preferably set at 1 to 1,000 mg/g, more preferably 10 to 500 mg/g,
still more preferably 30 to 300 mg/g. When the carboxylic acid
partly or wholly occurs as a salt, the total carboxylic acid amount
can be determined by once converting the salt to a totally acid
form or totally alkali salt form and then performing neutralization
titration. In cases where a carboxylic acid and/or a salt thereof
is formed by ester hydrolysis or the like on the occasion of
addition into kneading water, the analysis can be realized by
hydrolyzing the sample beforehand and then assaying the same.
[0079] For the shrinkage reducing agent for hydraulic materials
according to the invention, it is also preferred that the addition
amount of the shrinkage reducing agent for hydraulic materials
which is required for the mortar flow value in mortar flow testing
to amount to not less than 110 mm and for the amount of air
entrained to amount to not less than 11.+-.2% by volume is not less
than 1.0% by weight relative to cement on the solid matter basis or
that even when the shrinkage reducing agent for hydraulic materials
is added in an amount of 1.0% by weight or more relative to cement
on the solid matter basis, neither the mortar flow value in mortar
flow testing is 110 mm or more nor the amount of air entrained is
11.+-.2% by volume or more.
[0080] The mortar flow value in mortar testing is determined by the
following evaluation method.
[Evaluation method]
[0081] Ordinary portland cement (400 g) and 800 g of standard
Toyoura sand are dry-mixed in a Hobart type mortar mixer (model
N-50 (trademark), product of Hobart) at a low speed for 30 seconds
and, then, 240 g of water containing the above cement additive is
added, followed by 3 minutes of kneading at an intermediate speed
to give a mortar sample. The mortar obtained is immediately filled
into a hollow cylinder with an inside diameter of 53.5 mm and a
height of 50 mm as placed on a horizontal table to the top level of
the cylinder, this cylinder is gently lifted up, and the major axis
and minor axis of the mortar spread over the table are measured
with vernier calipers. The mean value thereof is reported as the
mortar flow value. For evaluating a cement composition entraining a
smaller amount of air, the amount of air entrained in mortar is
adjusted to 11.+-.2% by volume using an air entraining agent (AE
agent). The amount of air is calculated based on the mortar volume
and weight and the ratio of the materials used.
[0082] Further, the shrinkage reducing agent for hydraulic
materials according to the invention preferably satisfies both the
following requirements: (a) that the addition amount required for
attaining a certain shrinkage reducing effect should be not more
than 60 percent of the addition amount required when the starting
material polyether is used as the shrinkage reducing agent and (b)
that the addition amount required for reducing the unit water
content by 18% as compared with the unit water content in plain
mortar or plain concrete should be not less than 0.5% by weight
(relative to cement).
[0083] Referring to the above requirement (a), the shrinkage
reducing ability is preferably evaluated after 28 days of curing
according to JIS A 1129, for instance. The number of tests is
preferably at least three and the mean value is preferably used for
comparison. It is preferred that some shrinkage reducing agent is
evaluated simultaneously as a standard sample. Useful as such a
standard sample are, for example, the commercial products Nisso
Maruzen Chemical's "GE-42-2P" (trademark) (diethylene
glycol-dipropylene glycol monobutyl ether), Mitsubishi Gas
Chemical's neopentyl glycol, Taiheiyo Cement's "Tetraguard AS21"
(trademark), Fujisawa Pharmaceutical's "Hibiguard" (trademark) and
Takemoto Yushi's "Hibidan" (trademark), among others. The degree of
shrinkage of mortar or concrete varies depending on the cement
species used, extent of weathering, aggregate species, mix
proportions, kneading conditions, curing conditions and other
factors. Therefore, evaluation should be made under the same test
conditions and it is thus necessary to conduct tests on the same
day(s) using the same materials and effecting curing under the same
conditions.
[0084] The requirement (a) means that the shrinkage reducing agent
for hydraulic materials should be prepared in an appropriate manner
so that when the shrinkage reducing agent for hydraulic materials
is used in an amount of not more than 1.2% by weight relative to
cement on the solid matter basis, a shrinkage reducing effect can
be obtained which is equivalent to the effect obtained by using the
polyether, which is used in producing the polymer mentioned above,
as a shrinkage reducing agent in an amount of 2% by weight relative
to cement on the solid matter basis. It is said that the
commercially available polyether compounds known in the art as
shrinkage reducing agents need to be used in an amount of about 2%
by weight of the unit cement content. When the shrinkage reducing
agent for hydraulic materials which meets the above requirement (a)
according to the invention is used, a sufficient shrinkage reducing
effect can be produced at a lower addition amount as compared with
the so-far known shrinkage reducing agents and therefore the cost
of production of hydraulic materials such as cement compositions,
which are used almost everyday in large amounts, can be reduced.
More preferably, the weight ratio of the shrinkage reducing agent
for hydraulic materials to cement on the solid matter basis should
be not more than 1.0% by weight, still more preferably not more
than 0.8% by weight.
[0085] Referring to the above requirement (a), it is also preferred
that the shrinkage reducing agent for hydraulic materials be
prepared in an appropriate manner so that when the shrinkage
reducing agent for hydraulic materials is used in an amount of not
more than 1.2% by weight relative to cement on the solid matter
basis, a shrinkage reducing effect can be obtained which is
equivalent to the effect obtained by using diethylene
glycol-dipropylene glycol monobutyl ether in an amount of 2% by
weight relative to cement. More preferably, the weight ratio of the
shrinkage reducing agent for hydraulic materials to cement on the
solid matter basis should be not more than 1.0% by weight, still
more preferably not more than 0.8% by weight.
[0086] Referring to the above requirement (b), plain concrete is
preferably prepared according to JIS A 6204, for instance and plain
mortar is preferably prepared according to mix proportions by which
the addition amount in plain concrete can be reproduced. For
establishing reproducibility, the use of an air entraining (AE) and
high-range water reducing agent (to be mentioned later herein) as a
standard sample is preferred. Thus, if when the addition amount of
the air entraining and high-range water reducing agent required to
reduce the water content per unit volume of plain concrete by 18%
by weight is applied to plain mortar with the unit water content
being reduced by 18% by weight, the plain concrete and plain mortar
are equivalent in flowability, then the mortar test can be used as
a simplified method of evaluation. On that occasion, the evaluation
is preferably made at the same air content amount attained by
appropriately using an antifoaming agent and/or an AE agent, since
the difference in the amount of air entrained results in the
difference in apparent flowability.
[0087] Referring to the above (b), it is more preferred to reduced
the weight ratio of the shrinkage reducing agent for hydraulic
materials to cement on the solid matter basis to not less than 1.0%
by weight, still more preferably not less than 2.0% by weight.
[0088] The above-mentioned shrinkage reducing agent for hydraulic
materials according to the invention may be made into an additive
composition for hydraulic materials by incorporating therein such
ingredients as mentioned later herein. The composition can produce
various effects on hydraulic materials while producing the effects
of the invention. The concentration of the shrinkage reducing agent
for hydraulic materials in the additive composition for hydraulic
materials is not particularly restricted.
[0089] The present invention is further related to an additive
composition for hydraulic materials comprising a shrinkage reducing
agent for hydraulic materials and a cement dispersing agent, in
which additive composition the shrinkage reducing agent for
hydraulic materials comprises at least one polymer selected from
the group consisting of (A) a polymer having a structure derived
from the residue of a compound containing 1 to 30 carbon atoms and
one active hydrogen atom by the binding thereto of one oxyalkylene
chain having a carboxyl-containing side chain, (B) a polymer having
a structure derived from the residue of a compound containing 1 to
30 carbon atoms and two active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain, (C) a polymer having a structure
derived from the residue of a compound containing 1 to 30 carbon
atoms and at least three active hydrogen atoms by the binding
thereto of at least one oxyalkylene chain having a
carboxyl-containing side chain and (D) a polymer having a structure
derived from the residue of an amine by the binding thereto one
oxyalkylene chain having a carboxyl-containing side chain. Such
additive composition for hydraulic materials can provide hydraulic
materials with good properties contributing to the reduction of
drying shrinkage and, at the same time, makes it possible for good
dispersibility to be retained even when the amount of water to be
added to hydraulic materials is reduced, hence the composition
makes it possible to reduce the water content in hydraulic
materials to thereby improve the strength and durability of cured
products.
[0090] The additive composition for hydraulic materials according
to the invention may contain another or other ingredients other
than the above shrinkage reducing agent for hydraulic materials and
a cement dispersing agent. Preferably, however, the composition
contains the shrinkage reducing agent for hydraulic materials and
the cement dispersing agent.
[0091] In the above shrinkage reducing agent for hydraulic
materials, the polymer (A) and polymer (B) are the same as the
polymer (a) and polymer (b) mentioned hereinabove except that they
differ in the range of the number of carbon atoms to be contained
in the residue derived from an active hydrogen-containing compound.
The polymer (C) and polymer (D) are the same as the polymer (c) and
polymer (d) mentioned hereinabove.
[0092] The cement dispersing agent is not particularly restricted
so long as it is capable of dispersing cement particles. For
example, there may be mentioned known cement dispersing agents and
water reducing agents as well as ligninsulfonic acid, and
polycarboxylic acid type, naphthalene type, melamine type and
aminosulfonic acid type water reducing agents. These may be used
singly or two or more of them may be used combinedly. The ability
of the cement additive to disperse particles in hydraulic materials
is improved by incorporating such a cement dispersing agent, the
hydraulic materials become excellent in flowability, whereby the
workability is markedly improved, and the strength, durability and
other characteristics are improved as a result of reduction in
water content in the hydraulic materials.
[0093] Among the water reducing agents mentioned above,
ligninsulfonic acid and the like are generally referred to also as
air entraining and water reducing agents while the polycarboxylic
acid type, naphthalene type, melamine type, aminosulfonic acid type
and like water reducing agents are generally referred to also as
air entraining and high-range water reducing agents. Among such
water reducing agents, air entraining and high-range water reducing
agents are preferably used and polycarboxylic acid type air
entraining and high-range water reducing agents can be used with
advantage.
[0094] The proportions of the above shrinkage reducing agent for
hydraulic materials and the cement dispersing agent are not
particularly restricted. When an air entraining and high-range
water reducing agent is used as the cement dispersing agent, the
ratio (shrinkage reducing agent for hydraulic materials/air
entraining and high-range water reducing agent) is preferably 1/10
to 100/1 by weight on the solid matter basis. The addition amount
of the shrinkage reducing agent for hydraulic materials is larger
than the above weight ratio, the water reducing ability of the air
entraining and high-range water reducing agent may be impaired.
More preferred is a ratio between 1/100 to 50/1, still more
preferably 1/100 to 25/1.
[0095] The mode of addition of the additive composition for
hydraulic materials according to the invention to hydraulic
materials is not particularly restricted. For example, the
shrinkage reducing agent for hydraulic materials and the cement
dispersing agent may be mixed up beforehand, followed by addition
of the mixture to hydraulic materials, or the shrinkage reducing
agent for hydraulic materials and the cement dispersing agent may
be prepared separately and respectively added to hydraulic
materials. The same can be said about any other combination
mentioned herein.
[0096] The additive composition for hydraulic materials may further
contain, when necessary, such a solvent as mentioned above and/or
one or more other ingredients so long as the composition can
produce the effects of the invention. For example, those known
additives known in the art, such as those shown below under (1) to
(20), can be used in combination.
[0097] (1) Water soluble macromolecular substances: unsaturated
carboxylic acid polymers such as polyacrylic acid (sodium salt),
polymethacrylic acid (sodium salt), polymaleic acid (sodium salt),
acrylic acid-maleic acid copolymers (sodium salts); polyoxyethylene
or polyoxypropylene polymers or copolymers such as polyethylene
glycol and polypropylene glycol; nonionic cellulose ethers such as
methylcellulose, ethylcellulose, hydroxymethylcellulose,
hydroxyethylcellulose, carboxymethylcellulose,
carboxyethylcellulose and hydroxypropylcellulose; polysaccharides
producible by microbial fermentation such as yeast glucan, xanthan
gum and .beta.-1,3-glucans (which may be straight-chained or
branched; e.g. cardlan, paramylon, pachyman, scleroglucan,
laminaran); polyacrylamide; polyvinyl alcohol; starch; starch
phosphate ester; sodium alginate; gelatin; amino-containing acylic
acid copolymers and quaternized derivatives thereof; etc.;
[0098] (2) Macromolecule emulsions: copolymers of various vinyl
monomers such as alkyl (meth)acrylates, etc.;
[0099] (3) Retarders: hydroxy carboxylic acids and salts thereof
such as gluconic acid, glucoheptonic acid, arabonic acid, malic
acid and citric acid as well as such inorganic or organic salts
thereof as sodium, potassium, calcium, magnesium, ammonium and
triethanolamine salts; saccharides, for example monosaccharides and
oligosaccharides (disaccharides, trisaccharides, etc.) such as
glucose, fructose, galactose, saccharose, xylose, apiose, ribose,
and invert sugar, oligosaccharides such as dextrin, polysaccharides
such as dextran, and molasses comprising them; sugar alcohols such
as sorbitol; magnesium silicofluoride; phosphoric acid and salts
thereof or boric acid esters; amino-carboxylic acids and salts
thereof; alkali-soluble proteins; humic acid; tannic acid; phenols;
polyhydric alcohols such as glyecrol; phosphonic acid and
derivatives thereof such as aminotri(methylenephospho- nic acid),
1-hydroxyethylidene-1,1-diphosphonic acid,
ethylenediaminetetra(methylenephosphonic acid),
diethylenetriaminepenta(m- ethylenephosphonic acid) and alkali
metal salts and alkaline earth metal salts thereof; etc.;
[0100] (4) High-early-strength agents or accelerators: soluble
calcium salts such as calcium chloride, calcium nitrite, calcium
nitrate, calcium bromide and calcium iodide; chlorides such as iron
chloride and magnesium chloride; sulfuric acid salts; potassium
hydroxide; sodium hydroxide; carbonic acid salts; thiosulfuric acid
salts; formic acid and formic acid salts such as calcium formate;
alkanolamines; alumina cement; calcium aluminate silicate;
etc.;
[0101] (5) Mineral oil base antifoaming agents: kerosene, liquid
paraffin, etc.;
[0102] (6) Fat/oil base antifoaming agents: animal and vegetable
oils, sesame oil, castor oil, alkylene oxide-adducts thereof,
etc.;
[0103] (7) Fatty acid base antifoaming agents: oleic acid, stearic
acid, alkylene oxide-adducts thereof, etc.;
[0104] (8) Fatty acid ester base antifoaming agents: glycerol
monolicinoleate, alkenylsuccinic acid derivatives, sorbitol
monolaurate, sorbitol trioleate, natural wax, etc.;
[0105] (9) Oxyalkylene base antifoaming agents: polyoxyalkylenes
such as (poly)oxyethylene-(poly)oxypropylene adducts;
(poly)oxyalkyl ethers such as diethylene glycol heptyl ether,
polyoxyethylene oleyl ether, polyoxypropylene butyl ether,
polyoxyethylene-polyoxypropylene 2-ethylhexyl ether and
oxyethylene-oxypropylene adducts of C.sub.12-14 higher alcohols;
(poly)oxyalkylene (alkyl)aryl ethers such as polyoxypropylene
phenyl ether and polyoxyethylene nonylphenyl ether; acetylene
ethers such as alkylene oxide adducts derived from
2,4,7,9-tetramethyl-5-decyne-4,7-diol,
2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1-butyn-3-ol and like
acetylene alcohols; (poly)oxyalkylene fatty acid esters such as
diethylene glycol oleate, diethylene glycol laurate and ethylene
glycol distearate; (poly)oxyalkylenesorbitan fatty acid esters such
as polyoxyethylenesorbitan monolaurate and polyoxyethylenesorbitan
trioleate; (poly)oxyalkylene alkyl (aryl) ether sulfate ester salts
such as polyoxypropylene methyl ether sulfate sodium salt and
polyoxyethylene decylphenol ether sulfate sodium salt;
(poly)oxyalkylene alkyl phosphorate esters such as (poly)
oxyethylene stearyl phosphate ester; (poly)oxyalkylenealkylamines
such as polyoxyethylenelaurylamine; polyoxyalkyleneamides;
etc.;
[0106] (10) Alcohol base antifoaming agents: octyl alcohol,
hexadecyl alcohol, acetylene alcohol, glycols, etc.;
[0107] (11) Amide base antifoaming agents: acrylate polyamines
etc.;
[0108] (12) Phosphate ester base antifoaming agents: tributyl
phosphate, sodium octylphosphate, etc.;
[0109] (13) Metal soap base antifoaming agents: aluminum stearate,
calcium oleate, etc.;
[0110] (14) Silicone base antifoaming agents: dimethylsilicone
oils, silicone pastes, silicone emulsions, organic group-modified
polysiloxanes (polyorganosiloxanes such as dimethylpolysiloxane),
fluorosilicone oils, etc.;
[0111] (15) AE (air entraining) agents: resin soaps, saturated or
unsaturated fatty acids, sodium hydroxystearate, lauryl sulfates,
ABS (alkylbenzenesulfonic acids or salts thereof), LAS (linear
alkylbenzenesulfonic acids), alkanesulfonates, polyoxyethylene
alkyl(phenyl) ethers, polyoxyethylene alkyl(phenyl) ether sulfate
esters or salts thereof, polyoxythylene alkyl(phenyl) ether
phosphate esters or salts thereof, proteinaceous materials,
alkenylsulfosuccinic acids, .alpha.-olefinsulfonates, etc.;
[0112] (16) Other surfactants: polyalkylene oxide derivatives
produced by addition of at least 10 moles of at least one alkylene
oxide, such as ethylene oxide and propylene oxide, to a C.sub.6-30
aliphatic monohydric alcohol such as octadecyl alcohol and stearyl
alcohol, a C.sub.6-30 alicyclic monohydric alcohol such as abietyl
alcohol, a C.sub.6-30 monohydric mercaptan such as dodecyl
mercaptan, C.sub.6-30 alkylphenol such as nonylphenol, a C.sub.6-30
amine such as dodecylamine, or a C.sub.6-30 carboxylic acid such as
lauric acid and stearic acid; alkylated diphenyl ether sulfonic
acid salts which is constituted of two phenyl groups having a sulfo
group as bound together by ether bonding and may have an alkyl or
alkoxy group as a substituent; various anionic surfactants; various
cationic surfactants such as alkylamine acetates and
alkyltrimethylammonium chlorides; various nonionic surfactants;
various amphoteric surfactants; etc.;
[0113] (17) Waterproof agents: fatty acids (salts), fatty acid
esters, fats and oils, silicones, paraffins, asphalt, waxes,
etc.;
[0114] (18) Rust inhibitors: nitrites, phosphates, zinc oxide,
etc.;
[0115] (19) Crack-reducing agents: polyoxyalkyl ethers; alkanediols
such as 2-methyl-2,4-pentanediol; etc.;
[0116] (20) Expansive additives: ettringite-based ones, coal-based
ones, etc.
[0117] As other known cement additives, there may be mentioned
cement wetting agents, thickeners, separation reducing agents,
flocculants, known agents for reducing drying shrinkage, strength
increasing agents, self-leveling agents, rust inhibitors,
colorants, fungicides, blast furnace slag, fly ash, cinder ash,
clinker ash, husk ash, silica fume, silica powders, gypsum and the
like. These known cement additives may be used singly or two or
more of them may be used combinedly.
[0118] The additive composition for hydraulic materials according
to the invention can be widely applied in so-far known concrete
works, for instance. Such works are not particularly restricted but
include, among others, high strength concrete works, very high
strength concrete works, high flowing concrete works and flowing
concrete works. The mode of use is not particularly restricted. For
example, the composition may be used as it is in the form of a
solid or powder, for instance, or in the form of aqueous solution
or aqueous dispersion mixing with water.
[0119] The hydraulic materials in which the shrinkage reducing
agent for hydraulic materials or the additive composition for
hydraulic materials according to the invention is to be used are
not particularly restricted so long as they have hydraulicity or
latent hydraulicity. For example, mention may be made of portland
cement species such as ordinary portland cement and
high-early-strength portland cement, silica cement, fly ash cement,
portland blast-furnace slag cement, alumina cement, belite-rich
cement, various blended cement species; cement constituents such as
tricalcium silicate, dicalcium silicate, tricalcium aluminate and
tetracalcium aluminoferrite; and fly ash having latent
hydraulicity, among others. These may be used singly or two or more
of them may be used combinedly. Among them, ordinary portland
cement is generally and commonly used and suited for use.
[0120] The shrinkage reducing agent for hydraulic materials or the
additive composition for hydraulic materials of the present
invention is used preferably in an amount of 0.0001 to 10% by
weight relative to the hydraulic material on the solid matter
basis, for instance. When the amount is less than 0.0001% by
weight, the shrinkage reducing ability may possibly be slight. When
it exceeds 10% by weight, hydraulic materials may possibly undergo
curing retardation. The addition amount is more preferably 0.001 to
7% by weight, still more preferably 0.005 to 5% by weight, most
preferably 0.01 to 3% by weight.
[0121] The shrinkage reducing agent for hydraulic materials or the
additive composition for hydraulic materials of the present
invention can advantageously be incorporated in cement compositions
among hydraulic materials. Usable as such cement compositions are
those conventional ones, without any particular restriction. Thus,
there may be mentioned cement-water pastes (cement water slurries)
comprising cement and water; mortar comprising cement, water and
sand; and concrete comprising cement, water, sand and stone, among
others.
[0122] The cement to be incorporated in the above cement
compositions may be any of those known species, without any
particular restriction. Thus, mention may be made, for example, of
portland cement species such as ordinary portland cement and
high-early-strength portland cement, silica cement, fly ash cement,
portland blast-furnace slag cement, alumina cement, belite-rich
cement and various blended cement species. These may be used singly
or two or more of them may be used combinedly. Among them, portland
cement is generally and commonly used and the above-mentioned
cement additive can be applied thereto with advantage.
[0123] The addition amount of the cement additive in the above
cement compositions is not particularly restricted. For example,
the shrinkage reducing agent for hydraulic materials, which is an
essential constituent of the cement additive, is preferably used in
an amount of 0.0001 to 10% by weight relative to cement on the
solid matter basis. When the amount is less than 0.0001% by weight,
the shrinkage reducing ability is not sufficiently effected. When
it exceeds 10% by weight, hydraulic materials may possibly undergo
curing retardation. The addition amount is more preferably 0.001 to
7% by weight, still more preferably 0.005 to 5% by weight, most
preferably 0.01 to 3% by weight.
[0124] The proportion of water in the above cement compositions is
not particularly restricted but preferably is 10 to 80% by weight
relative to cement. When the amount of water is less than 10% by
weight, the respective ingredients are mixed only to an
insufficient extent, so that the compositions cannot be molded in
some instances or the strength may decrease in other cases. When it
is larger than 80% by weight, the strength of cured products
obtained from the cement compositions may possibly decrease. The
amount of water is more preferably 15 to 75% by weight, still more
preferably 20 to 70% by weight, most preferably 25 to 65% by
weight.
[0125] When the above cement compositions are used in the form of
mortar or concrete, the sand and stone to be incorporated in the
cement compositions may be any of those so far used in conventional
cement compositions, without any particular restriction. Thus,
mention may be made, for example, of natural fine aggregates such
as river sand, sea sand and pit sand produced from rocks by the
power of nature; artificial fine aggregates produced by crushing
such rocks or slabs; lightweight fine aggregates; and the like. The
addition amount of sand may be the same as in conventional cement
compositions, without any particular restriction. The addition
amount of stone, too, may be the same as in conventional cement
compositions; there is no particular restriction. The fine
aggregate (sand) ratio, for instance, is preferably 20 to 60% by
weight. When it is less than 20% by weight, a rough concrete is
obtained and, with concrete showing a large slump, the coarse
aggregate and mortar fractions may tend to separate from each
other. When it exceeds 60% by weight, higher unit cement content
and unit water content are required, possibly giving concrete poor
in flowability. The ratio is preferably 30 to 50% by weight.
[0126] Another or other materials may be incorporated in the above
cement compositions, when necessary. The other materials are not
particularly restricted but include the same ones as used in
conventional cement compositions, for example silica fume, blast
furnace slag, silica powders, and fibrous materials such as steel
fibers and glass fibers. The addition amounts of these materials
are not particularly restricted but may be the same as those in
conventional cement compositions.
[0127] The method of preparing the cement compositions is not
particularly restricted. Mention may be made, for instance, of the
same method as in preparing conventional cement compositions which
comprises, for example, adding the cement additive or an aqueous
dispersion or solution thereof to a mixer on the occasion of
blending cement and water together, if necessary together with
another or other ingredients, and mixing up the whole; the method
comprising mixing cement with water, if necessary together with
another or other ingredients, beforehand and adding to the
resulting mixture the cement additive or an aqueous dispersion or
solution thereof and mixing up the whole; the method comprising
mixing cement with another or other ingredients as necessary
beforehand, adding to the mixture obtained the cement additive or
an aqueous dispersion or solution thereof and water, and mixing up
the whole; and the method comprising mixing cement with the cement
additive or an aqueous dispersion or solution thereof, if necessary
together with another or other ingredients, adding water to the
resulting mixture and mixing up the whole.
[0128] The above cement compositions give cured products excellent
in strength and durability, among others, and therefore can give
improved safety to the structures made therefrom or can reduce the
cost of repairing. Therefore, they can be used widely and
advantageously in various fields, such as civil engineering and
architectural structures. Such cement compositions, too, constitute
a preferred mode of embodiment of the present invention.
[0129] The shrinkage reducing agent for hydraulic materials
according to the invention, which has the above constitution, when
applied to hydraulic materials such cement paste, mortar, concrete
and like cement compositions, can improve the strength and
durability of cured products by sufficiently preventing the
progress of shrinkage of the cured products upon drying and thereby
producing a better cracking preventing effect while the addition
amount to hydraulic materials can be suppressed and the cost of
production of hydraulic materials can thus be reduced. Thus, it can
improve the safety of civil engineering and architectural
structures and suppress the cost of repairing thereof, hence is
high in general versatility.
EXAMPLES
[0130] The following examples illustrate the present invention in
further detail. They are, however, by no means limitative of the
scope of the invention.
[0131] In the examples, "part(s)" and "%" mean "part(s) by weight"
and "% by weight", respectively, unless otherwise specified.
(Method of water content measurement)
[0132] The water content was determined using a Karl Fischer
moisture meter. The apparatus used was Metler's Karl Fischer
titrator DL18 (trademark). Hayashi Junyaku Kogyo's Hydranal
Composite 5K (trademark) was used as Karl Fischer's reagent.
(Hydroxyl value determination)
[0133] The hydroxyl value, which is the number of milligrams of
potassium hydroxide corresponding to the amount of the hydroxyl
group contained in 1 g of the sample, was determined in the
following manner.
[0134] (1) A phthalating reagent is prepared by adding 200 g of
pyridine to 35 g of phthalic anhydride and effecting dissolution of
the latter.
[0135] (2) About 1 g of the sample is accurately weighed in a
Teflon vessel and 10 ml of the phthalating reagent is added.
Separately, 10 ml of the phthalating reagent alone is added to a
Teflon vessel for use as a blank.
[0136] (3) The above vessel is placed on a hot plate heated at
120.degree. C. and allowed to stand for about 1 hour with
occasional stirring to thereby phthalate the hydroxyl group in the
sample.
[0137] (4) After cooling, titration is carried out using 0.5 N
aqueous potassium hydroxide and the hydroxyl value is calculated
from the difference in acid number between the sample and blank.
Hiranuma Sangyo's automatic titrator COMTITE-550 (trademark) was
used for the titration.
(Solid content determination)
[0138] The solid content was calculated by measuring the
nonvolatile matter in the sample. About 1 g of the sample was
accurately weighed and then placed in a drier in a nitrogen
atmosphere maintained at 130.degree. C. for 1 hour and, after
cooling, the sample was again accurately weighed, and the
nonvolatile matter content was calculated.
(Molecular weight and molecular weight distribution
determination)
[0139] The molecular weight and molecular weight distribution were
determined by GPC (gel permeation chromatography) under the
following conditions:
[0140] Precolumn: KF800D (trademark, product of Shodex), one
column;
[0141] Column: KF800L (trademark, product of Shodex), three columns
connected in series;
[0142] Column temperature: 40.degree. C. (adjusted by means of a
column oven);
[0143] Mobile phase: Chloroform (for high performance liquid
chromatography, product of Wako Pure Chemical Industries);
[0144] Flow rate: 1.0 ml/min;
[0145] Test sample: The sample was diluted with the mobile phase to
0.5% on the solid matter basis and the dilution was filtered
through a 0.45-micron filter, ChromatoDisk 13 N (trademark, product
of GL Science);
[0146] Injection size: 100 .mu.l;
[0147] Detector: RI Shodex SE-61 differential refractive index
detector (trademark, product of Shodex);
[0148] Standard samples for working curve construction: Standard
polyethylene glycol samples,
[0149] Mp=960, 1470, 4250 and 12600 (trademarks, product of GL
Science),
[0150] Mp=21000, 45000, 85000, 160000 (trademarks, product of
Tosoh)
(Outline of working curve construction)
[0151] A cubic curve is constructed by plotting the peak top times
(abscissa) of the above samples against the molecular weights
(ordinate) thereof. The peak top molecular weights (Mp) were used
as the molecular weights.
(Molecular weight calculation)
[0152] The data for the test sample are computed by Nippon Bunko
data processing system for chromatography BORWIN (trademark), and
the molecular weight is determined. The calibration curve
approximating equation for the molecular weight was:
log M=A+BRt+CRt.sup.2+DRt.sup.3
[0153] where M=molecular weight, Rt=retention time (min), A=24.11,
B=-2.072, C=0.0759, D=-0.00103.
(Total acid number determination)
[0154] The total acid number, which is the number of milligrams of
potassium hydroxide equivalent to the total amount of carboxylic
acids contained in 1 g of the sample, was determined in the
following manner:
[0155] (1) About 1 g of the sample is accurately weighed in a
beaker and 50 g of water (or acetonitrile) and a magnetic stirrer
are placed therein.
[0156] (2) 0.1 N aqueous hydrochloric acid (reagent for titration)
is added until a pH of not higher than 2.0 is obtained.
[0157] (3) 0.1 N aqueous sodium hydroxide (reagent for titration)
is added dropwise, and the amount of acid is determined from the
difference between the first and second inflection points. Hiranuma
Sangyo's automatic titrator COMTITE-550 (trademark) was used.
[0158] First, additives were prepared in the following manner.
Production Example 1
[0159] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of Softanol 30 (trademark, product of Nippon Shokubai;
C.sub.12-14 secondary alcohol-ethylene oxide (EO) (3 moles on
average) adducts, molecular weight 332, molecular weight
distribution (Mw/Mn)=1.36) and 15.5 parts of maleic acid, and the
charge was heated to 125.+-.5.degree. C. in a nitrogen atmosphere
for melting and mixing up. Then, while maintaining the temperature
at 125.+-.5.degree. C., 14.5 parts of acrylic acid and 3.3 parts of
tert-butylperoxy isopropyl carbonate (trademark Perbutyl I, product
of Nippon Oil and Fat) were separately added dropwise continuously
over 1 hour. Thereafter, stirring was continued at 125.+-.5.degree.
C. for 1 hour, to give a graft polymer (graft polymer 1).
[0160] The graft polymer 1 had a weight average molecular weight
(Mw) of 11,700 and a molecular weight distribution (Mw/Mn) of 16.8.
The graft polymer 1 also had a total acid number of 71.9 mg/g.
[0161] Water (275.2 parts) and 7.6 parts of an aqueous solution of
sodium hydroxide (30% solution) were added to 30.6 parts of the
graft polymer 1 to give an aqueous solution of the sodium salt of
graft polymer 1. This additive is referred to as "additive 1".
[0162] The additive 1 obtained had a pH of 8.3 and a solid content
of 9.1% and occurred as a pale yellow turbid solution. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Production Example 2
[0163] A stainless steel pressure reactor equipped with a
thermometer, a stirrer, a nitrogen inlet tube and a pressure gage
was charged with 601.0 parts of isopropyl alcohol (product of Wako
Pure Chemical Industries; moisture content 0.04%) and 0.4 part of
sodium hydroxide. The pressure reactor inside was purged with
nitrogen with stirring, and the pressure reactor inside was heated
to 100.+-.5.degree. C. Then, 1,321.5 parts of ethylene oxide was
introduced into the reactor at a temperature of 100 to 140.degree.
C. and a safety pressure of 2.0.times.10.sup.-1 to
7.8.times.10.sup.-1 MPa. After maturation, the volatile matter was
removed to give an intermediate (intermediate a), namely an
isopropyl alcohol-ethylene oxide adduct.
[0164] The molecular weight of intermediate a was determined based
on its hydroxyl value and found to be 245.8. Thus, the average
number of moles of ethylene oxide added to isopropyl alcohol was
calculated at 4.2.
[0165] Then, a stainless steel pressure reactor equipped with a
thermometer, a stirrer, a nitrogen inlet tube and a pressure gage
was charged with 491.6 parts of intermediate a and 0.26 part of
sodium hydroxide. The pressure reactor inside was purged with
nitrogen with stirring, and the pressure reactor inside was heated
to 120.+-.10.degree. C. Then, 402.8 parts of propylene oxide was
introduced into the reactor at a temperature of 120.+-.10.degree.
C. and a safety pressure of 2.9.times.10.sup.-1 to
7.8.times.10.sup.-1 MPa. After maturation, the volatile matter was
removed to give an intermediate (intermediate b), namely an
isopropyl alcohol-ethylene oxide-propylene oxide adduct.
[0166] The number of moles of propylene oxide added in intermediate
b was calculated at 3.3 based on the material balance. Thus, the
intermediate b was regarded as a product resulting from blockwise
addition of 4.2 moles (on average) of ethylene oxide and 3.3 moles
(on average) of propylene oxide to isopropyl alcohol (containing 3
carbon atoms).
[0167] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of the intermediate b and 15.6 parts of maleic acid, and the
charge was heated to 125.+-.5.degree. C. in a nitrogen atmosphere
for melting and mixing up. Then, while maintaining the temperature
at 125.+-.5.degree. C., 14.4 parts of acrylic acid and 3.0 parts of
tert-butylperoxy isopropyl carbonate (trademark Perbutyl I, product
of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
125.+-.5.degree. C. for 1 hour, to give a graft polymer (graft
polymer 2).
[0168] The graft polymer 2 had a weight average molecular weight
(Mw) of 24,300 and a molecular weight distribution (Mw/Mn) of 30.7.
The graft polymer 2 also had a total acid number of 118.7 mg/g.
[0169] Addition of 276.6 parts of water to 30.7 parts of the graft
polymer 2 gave a semiturbid solution with a pH of 2.4. Thereto was
added 9.4 parts of an aqueous solution of sodium hydroxide (30%
solution) to give an aqueous solution of the sodium salt of graft
polymer 2. This is referred to as "additive 2". The additive 2
obtained occurred as a pale yellow transparent solution with a pH
of 7.7 and a solid content of 9.1% and did not separate for at
least 1 month at room temperature.
Production Example 3
[0170] A commercial shrinkage reducing agent, Tetraguard AS21
(trademark, product of Taiheiyo Cement) comprising lower
alcohol-derived alkylene oxide adducts had a water content of 14.6%
as measured by a moisture meter. Therefore, it was dehydrated under
reduced pressure and warming using an evaporator (50.degree. C.,
not higher than 1.3.times.10.sup.-2 MPa) and further dehydrated
thoroughly in a vacuum drier (50.degree. C., not higher than
6.7.times.10.sup.-3 MPa) to give dehydrated Tetragurad AS21
(moisture content 0.4%). The dehydrated Tetragurad AS21 thus
obtained had a hydroxyl value of 181.7 mg/g. Based on this result,
the average molecular weight of Tetragurad AS21 was calculated at
309. The molecular weight distribution (Mw/Mn) of Tetragurad AS21
was measured and found to be 1.13.
[0171] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 80.0
parts of the dehydrated Tetragurad AS21 (trademark, product of
Taiheiyo Cement) and 10.4 parts of maleic acid, and the charge was
heated to 110.degree. C. in a nitrogen atmosphere for melting and
blending. Then, while maintaining the temperature at
100.+-.10.degree. C., 9.2 parts of acrylic acid and 2.0 parts of
tert-butylperoxy isopropyl carbonate (Perbutyl I (trademark,
product of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
120.+-.5.degree. C. for 1 hour to give a graft polymer (graft
polymer 3).
[0172] The graft polymer 3 had a weight average molecular weight
(Mw) of 6,300 and a molecular weight distribution (Mw/Mn) of
18.9.
[0173] Water (228.9 parts) and 16.7 parts of an aqueous solution of
sodium hydroxide (48% solution) were added to 100 parts of the
graft polymer 3 to give an aqueous solution of the sodium salt of
graft polymer 3. This additive is referred to as "additive 3". The
additive 3 obtained occurred as a pale yellow transparent solution
with a pH of 6.8 and a solid content of 26.6% and did not separate
for at least 6 months at room temperature (about 20.degree.
C.).
Comparative Example 1 and Comparative Example 9
[0174] No shrinkage reducing agent was added.
Comparative Examples 2 and 3 and Comparative Example 10
[0175] The dehydrated Tetraguard AS21 (trademark, product of
Taiheiyo Cement) obtained in Production Example 3 was used for
comparison (comparative additive 1).
Comparative Example 4
[0176] Diethylene glycol-dipropylene glycol monobutyl ether
(GE-42-2P, (trademark), product of Nisso Maruzen Chemical) was used
for comparison (comparative additive 2).
Comparative Examples 5 and 6
[0177] The same agent Softanol 30 (trademark, product of Nippon
Shokubai) as used in Production Example 1 was used for comparison
(comparative additive 3).
Comparative Examples 7 and 8
[0178] The intermediate b synthesized in Production Example 2 was
used for comparison (comparative additive 4).
[0179] Using the additives prepared in the above manner, mortar
mixes were kneaded, and test pieces prepared and evaluated for
shrinkage reducing ability (cracking preventing ability) by
measuring changes in length.
(Mortar kneading)
[0180] Ordinary portland cement (400 g, product of Taiheiyo Cement)
and 800 g of standard Toyoura sand were dry-mixed in a Hobart type
mortar mixer (model N-50 (trademark), product of Hobart) for 30
seconds and, then, 260 g of an additive mixture prepared by
diluting the additives specified in Table 1 or 2, each weighed as
specified in Table 1 or 2, with water, followed by 3 minutes of
kneading at an intermediate speed to give a mortar sample.
[0181] The mortar obtained was immediately filled into a stainless
steel hollow cylinder with an inside diameter of 53.5 mm and a
height of 50 mm as placed on a horizontal table to the top level of
the cylinder, this cylinder was gently lifted up, and the major
axis and minor axis of the mortar spread over the table were
measured with vernier calipers. The mean value thereof was reported
as the mortar flow value. When the amount of air entrained is
large, flow and shrinkage values are apparently exaggerated and
therefore the amount of air entrained should be constant. Thus, an
appropriate amount of a defoaming agent (of oxyalkylene type) was
used.
[0182] The amount of air was calculated based on the mortar volume
and weight and the ratio of the materials used. The results
obtained are shown in Table 1.
(Preparation of test pieces)
[0183] Test pieces (4.times.4.times.16 cm) were prepared according
to JIS A 1129. Frameworks were coated with a silicone grease in
advance so as to render them impermeable to water and facilitate
release from the frameworks. A gage plug was mounted on each end of
each test piece. The mortar obtained by kneading was cast into each
framework and preliminary curing was effected in a constant
temperature, constant humidity chamber (PL-2G (trademark), product
of Tabai Espeque) maintained at a temperature of 20.degree. C. and
a humidity of 60%. After 4 days, the test piece was released from
the framework and the silicone grease adhering to the surface of
the test piece was washed off with water using a sponge-made
scrubbing brush. Then, the test piece was cured in still water at
20.degree. C. for 7 days.
(Length change measurement)
[0184] A dial gauge (product of Nishinippon Shikenki) was used
according to JIS A 1129. The surface water on the test piece cured
in still water for 7 days was wiped off with a paper towel and,
immediately, the length of the test piece was measured and this
time point was taken as time zero. The test piece was then stored
in a constant temperature, constant humidity chamber maintained at
a temperature of 20.degree. C. and a humidity of 60% and subjected
to length measurement at timed intervals. The thus-obtained results
of length change measurements are shown in Table 1.
1 Addition amount Flow value Air content Change in length (.mu.m)
Additives, used (weight %) (mm) (vol. %) Day 0 Day 2 Day 4 Day 7
Day 14 Day 23 Day 28 Ex. 1 Additive 1 0.5 128 6.4 0 -1 13 15 38 70
84 AE and high-range water 0.15 reducing agent Antifoam 1 Ex. 2
Additive 2 0.5 181 0 0 9 32 44 83 117 131 AE and high-range water
0.15 reducing agent Antifoam 1 Ex. 3 Additive 2 1 174 3.5 0 4 27 40
74 105 117 AE and high-range water 0.15 reducing agent Antifoam 0.5
Compar. AE and high-range water 0.15 134 0.6 0 15 40 54 104 142 159
Ex. 1 reducing agent Antifoam 0.2 Compar. Comparative additive 1 1
130 0 0 10 30 38 76 113 130 Ex. 2 AE and high-range water 0.15
reducing agent Antifoam 0.2 Compar. Comparative additive 1 2 148 0
0 9 26 32 68 103 122 Ex. 3 AE and high-range water 0.15 reducing
agent Antifoam 0.2 Compar. Comparative additive 2 2 141 0 0 6 22 27
60 98 115 Ex. 4 AE and high-range water 0.15 reducing agent
Antifoam 0.2 Compar. Comparative additive 3 1 138 0.9 0 4 20 28 64
100 117 Ex. 5 AE and high-range water 0.15 reducing agent Antifoam
0.2 Compar. Comparative additive 3 2 139 1.2 0 3 20 25 61 98 115
Ex. 6 AE and high-range water 0.15 reducing agent Antifoam 0.2
Compar. Comparative additive 4 1 138 0.2 0 12 33 43 85 123 141 Ex.
7 AE and high-range water 0.15 reducing agent Antifoam 0.2 Compar.
Comparative additive 4 2 129 0.3 0 9 29 35 70 104 121 Ex. 8 AE and
high-range water 0.15 reducing agent Antifoam 0.2 *The addition
amounts (except for antifoam) are based on the solid content of
cement. The addition amount of the antifoam is based on the solid
content of the air entraining and high range water reducing agent.
The AE and high-range water reducing agent used was Aqualoc FC-900
(product of Nippon Shokubai).
(Test results)
[0185] The properties of each fresh mortar sample obtained are
shown in Table 1. For securing a certain extent of mortar
flowability, a specified amount of an air entraining and high-range
water reducing agent was used. The air entraining and high-range
water reducing agent used was Aqualoc FC-900 (trademark, product of
Nippon Shokubai, polycarboxylic acid type). As a result, a
flowability of not less than 110 mm was secured in all the tests.
Further, when the amount of air is large, the drying shrinkage
increases and an apparently exaggerated change in length maybe
observed. For this reason, an appropriate amount of an antifoaming
agent was added to thereby adjust the amount of air.
[0186] Table 1 shows the shrinkage length (.mu.m) on each specified
day from day 0 (the day when curing in water was finished). A
smaller numerical value indicates a smaller shrinkage and suggests
that the structure in question will be prevented from cracking due
to shrinkage.
[0187] In the following, referring to the results obtained on day
28 as shown in Table 1, the contents of Table 1 are explained.
[0188] In Comparative Example 1, the test piece made without adding
any additive for shrinkage reduction and initially having a length
of 16 cm shrinked by 159 .mu.m. In Comparative Example 2, the
addition of 1% of a commercially available shrinkage reducing agent
(Tetraguard AS21 (trademark), product of Taiheiyo Cement)
suppressed the shrinkage to 130 .mu.m and, in Comparative Example
3, the addition of 2% of the same agent suppressed the shrinkage to
122 .mu.m. When compared with Comparative Example 1, the reduction
in shrinkage was 29 .mu.m at the addition amount of 1% and it was
37 .mu.m at the addition amount of 2%. With the increase in
addition amount, the shrinkage reducing effect thus increased.
[0189] The same applied to Comparative Examples 7 and 8. When
compared with Comparative Example 1, the reduction in shrinkage was
18 .mu.m at the addition amount of 1% and it was 38 .mu.m at the
addition amount of 2%. It is seen that the shrinkage reducing
effect increased with the increase in addition amount.
[0190] In Example 1, the additive 1 of the invention was used,
which was synthesized using Softanol 30 (trademark, product of
Nippon Shokubai), which was used in Comparative Examples 5 and 6,
as a starting material. The shrinkage was reduced as compared with
Comparative Example 1 (no addition) and further, the results
obtained indicate that at an addition amount of not more than half
as compared with Comparative Examples 5 and 6 in which the starting
material Softanol 30 was used, the shrinkage reducing effect
exceeded those obtained by using that starting material as the
shrinkage reducing agent.
[0191] In Example 2 and Example 3, the additive 2 of the invention
was used, which was synthesized starting with the polyether
(intermediate b) used in Comparative Examples 7 and 8. The
shrinkage was reduced as compared with Comparative Example 1 (no
addition). Further, while the reduction in shrinkage was 38 .mu.m
in Comparative Example 8 in which the starting material
intermediate b was used at a level of 2% (on cement basis), the
shrinkage was reduced by 42 .mu.m in Example 3 in which the
addition amount was 1% (on cement basis). Thus, it can be seen that
the additives of the invention can produce, at half the addition
amount, the same shrinkage reducing effect as those produced by the
starting materials.
Example 4
[0192] Using the additives 3 obtained in Production Example 3
prepared in the above manner, mortar mixes were kneaded, and test
pieces prepared and evaluated for shrinkage reducing ability
(cracking preventing ability) by measuring changes in length. The
results are shown in Table 2.
Comparative Example 9
[0193] No shrinkage reducing agent was added.
Comparative Example 10
[0194] The dehydrated Tetraguard AS21 (trademark, product of
Taiheiyo Cement) obtained in Production Example 3 was used for
comparison (comparative additive 1).
2 Addition amount Air content Change in length (.mu.m) Additives
used (weight %) Flow value (mm) (vol. %) Day 0 Day 2 Day 7 Day 18
Day 28 Ex. 4 Comparative additive 3 1 149 2.3 0 28 76 189 213 AE
and high-range 0.15 water reducing agent Antifoam 0.1 Compar. AE
and high-range 0.15 140 5.5 0 26 93 217 245 Ex.9 water reducing
agent Compar. Comparative additive 1 2.0 115 0.0 0 20 80 197 225
Ex. 10 AE and high-range 0.15 water reducing agent *The addition
amounts (except for antifoam) are based on the solid content of
cement. The addition amount of the antifoam is based on the solid
content of the air entraining and high range water reducing agent.
The AE and high-range water reducing agent used was Aqualoc FC-900
(product of Nippon Shokubai).
[0195] In Example 4, the additive 3 of the invention was used,
which was synthesized using the dehydrated Tetraguard AS21
(trademark, product of Taiheiyo Cement), which was used in
Comparative Example 10, as a starting material. The shrinkage was
reduced as compared with Comparative Example 9 (no addition) and
further, the results obtained indicate that at an addition amount
of not more than half as compared with Comparative Example 10 in
which the starting material dehydrated Tetraguard AS21 (trademark,
product of Taiheiyo Cement) was used, the shrinkage reducing effect
exceeded those obtained by using that starting material as the
shrinkage reducing agent.
Production Example 4
[0196] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 105.0
parts of Softanol 30 (trademark, product of Nippon Shokubai) and
23.3 parts of maleic acid, and the charge was heated to
125.+-.5.degree. C. in a nitrogen atmosphere for melting and mixing
up. Then, while maintaining the temperature at 125.+-.5.degree. C.,
21.7 parts of acrylic acid and 4.9 parts of tert-butylperoxy
isopropyl carbonate (trademark Perbutyl I, product of Nippon Oil
and Fat) were individually added dropwise continuously over 1 hour.
Thereafter, stirring was continued at 125.+-.5.degree. C. for 1
hour, to give a graft polymer (graft polymer 4).
[0197] Water (71.4 parts) and 2.9 parts of an aqueous solution of
sodium hydroxide (30% aqueous solution) were added to 6.6 parts of
the graft polymer 4 to give an aqueous solution of the sodium salt
of graft polymer 4. This is referred to as "additive 4".
[0198] The additive 4 obtained had a pH of 7.0 and a solid content
of 8.5% and occurred as a pale yellow turbid solution. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Production Example 5
[0199] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of Softanol 70H (trademark, product of Nippon Shokubai;
C.sub.12-14 secondary alcohol-ethylene oxide (EO; 7 moles on
avarage) adducts) and 15.5 parts of maleic acid, and the charge was
heated to 125.+-.5.degree. C. in a nitrogen atmosphere for melting
and mixing up. Then, while maintaining the temperature at
125.+-.5.degree. C., 14.5 parts of acrylic acid and 3.3 parts of
tert-butylperoxy isopropyl carbonate (trademark Perbutyl I, product
of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
125.+-.5.degree. C. for 1 hour, to give a graft polymer (graft
polymer 5).
[0200] Water (108.1 parts) and 3.9 parts of an aqueous solution of
sodium hydroxide (30% aqueous solution) were added to 12.7 parts of
the graft polymer 5 to give an aqueous solution of the sodium salt
of graft polymer 5. This is referred to as "additive 5".
[0201] The additive 5 obtained occurred as a pale yellow
transparent solution having a pH of 7.0 and a solid content of
10.4%. It did not separate for at least 1 month at room
temperature.
Example 5 and Example 6
[0202] Using the additives obtained in the above manner, mortar
kneading was performed and test pieces were prepared by the methods
mentioned above and the specimens were evaluated for shrinkage
reducing ability (cracking preventing ability) by measuring the
changes in length. The results are shown in Table 3.
Comparative Example 11
[0203] No shrinkage reducing agent was added.
Comparative Example 12
[0204] Softanol 30 (trademark, product of Nippon Shokubai) was used
for comparison (comparative additive 3).
Comparative Example 13
[0205] Softanol 70H (trademark, product of Nippon Shokubai) was
used for comparison (comparative additive 5).
Comparative Example 14
[0206] The dehydration product derived from Tetraguard AS21
(trademark, product of Taiheiyo Cement) as obtained in Production
Example 3 was used for comparison (comparative additive 1).
[0207] The results obtained in Comparative Examples 11 to 14 are
shown in Table 3.
3 Mortar evaluation result Addition Air Additives amount Flow value
content Change in length [.mu.m] Ex. No. used (weight %) (mm)
(volume %) Day 0 Day 3 Day 7 Day 14 Day 21 Day 28 Ex. 5 FC-900 0.10
114.5 5.1 0.0 26.3 31.5 70.5 98.5 109.9 Antiform 0.50 Additive 4
0.50 Ex. 6 FC-900 0.10 202.0 9.6 0.0 23.0 37.0 72.0 114.0 115.8
Antiform 0.50 Additive 5 0.50 Compar. FC-900 0.10 113.0 0.0 0.0
44.8 78.0 134.5 180.0 187.4 Ex. 11 Antiform 0.50 Compar. FC-900
0.10 117.5 0.7 0.0 25.3 34.5 81.0 112.5 120.8 Ex. 12 Antiform 0.50
Comparative 2.00 Additive 3 Compar. FC-900 0.10 118.0 61.0 Could
not evaluated due to excessively high air content. Ex. 13 Antiform
0.50 Comparative 2.00 Additive 5 Compar. FC-900 0.10 115.0 0.0 0.0
25.4 35.5 81.0 112.5 123.4 Ex. 14 Antiform 0.50 Comparative 2.00
Additive 1
[0208] In Example 5, the additive 4 of the invention was used,
which was synthesized starting with Softanol 30 (trademark, product
of Nippon Shokubai) used in Comparative Example 12 and, in Example
6, the additive 5 of the invention was used, which was synthesized
starting with Softanol 70H (trademark, product of Nippon Shokubai)
used in Comparative Example 13. In Examples 5 and 6, the shrinkage
was reduced as compared with Comparative Example 11 (no addition)
or Comparative Example 14 in which a commercial shrinkage reducing
agent (comparative additive 1) was used and, further, the results
obtained indicate that the additives 4 and 5, even when used at an
addition amount of not more than half as compared with Comparative
Examples 12 and 13 in which the starting materials Softanol 30 and
Softanol 70H were used, respectively, show a higher shrinkage
reducing effect than the effects obtained by using the starting
materials as shrinkage reducing agents.
Production Example 6
[0209] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 320.0
parts of Softanol EP90150 (trademark, product of Nippon Shokubai;
C.sub.12-14 secondary alcohol-EO (9 moles)-propylene oxide (PO; 15
moles) adducts) and 41.3 parts of maleic acid, and the charge was
heated to 125.+-.5.degree. C. in a nitrogen atmosphere for melting
and mixing up. Then, while maintaining the temperature at
125.+-.5.degree. C., 38.7 parts of acrylic acid and 8.8 parts of
tert-butylperoxy isopropyl carbonate (trademark Perbutyl I, product
of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
125.+-.5.degree. C. for 1 hour, to give a graft polymer (graft
polymer 6).
[0210] Water (90.3 parts) and 4.8 parts of an aqueous solution of
sodium hydroxide (30% aqueous solution) were added to 16.0 parts of
the graft polymer 6 to give an aqueous solution of the sodium salt
of graft polymer 6. This is referred to as "additive 6".
[0211] The additive 6 obtained occurred as a pale yellow turbid
solution having a pH of 7.4 and a solid content of 15.3%. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Production Example 7
[0212] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 141.0
parts of Softanol EP90150 (trademark, product of Nippon Shokubai)
and 4.7 parts of maleic acid, and the charge was heated to
125.+-.5.degree. C. in a nitrogen atmosphere for melting and mixing
up. Then, while maintaining the temperature at 125.+-.5.degree. C.,
4.3 parts of acrylic acid and 1.0 part of tert-butylperoxy
isopropyl carbonate (trademark Perbutyl I, product of Nippon Oil
and Fat) were individually added dropwise continuously over 1 hour.
Thereafter, stirring was continued at 125.+-.5.degree. C. for 1
hour, to give a graft polymer (graft polymer 7).
[0213] Water (82.4 parts) and 1.9 parts of an aqueous solution of
sodium hydroxide (30% aqueous solution) were added to 44.9 parts of
the graft polymer 7 to give an aqueous solution of the sodium salt
of graft polymer 7. This is referred to as "additive 7".
[0214] The additive 7 obtained occurred as a pale yellow turbid
solution having a pH of 7.1 and a solid content of 32.9%. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Production Example 8
[0215] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of Softanol EP7085 (trademark, product of Nippon Shokubai;
C.sub.12-14 secondary alcohol-EO (7 moles)-PO (8.5 moles) adducts)
and 15.5 parts of maleic acid, and the charge was heated to
125.+-.5.degree. C. in a nitrogen atmosphere for melting and mixing
up. Then, while maintaining the temperature at 125.+-.5.degree. C.,
14.5 parts of acrylic acid and 3.3 parts of tert-butylperoxy
isopropyl carbonate (trademark Perbutyl I, product of Nippon Oil
and Fat) were individually added dropwise continuously over 1 hour.
Thereafter, stirring was continued at 125.+-.5.degree. C. for 1
hour, to give a graft polymer (graft polymer 8).
[0216] Water (51.2 parts) and 6.4 parts of an aqueous solution of
sodium hydroxide (30% aqueous solution) were added to 25.1 parts of
the graft polymer 8 to give an aqueous solution of the sodium salt
of graft polymer 8. This is referred to as "additive 8".
[0217] The additive 8 obtained occurred as a pale yellow turbid
solution having a pH of 7.3 and a solid content of 31.0%. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Example 7, Example 8 and Example 9
[0218] Using the additives obtained in the above manner, mortar
kneading was performed and test pieces were prepared by the methods
mentioned above and the specimens were evaluated for shrinkage
reducing ability (cracking preventing ability) by measuring the
changes in length. The results are shown in Table 4.
Comparative Example 15
[0219] No shrinkage reducing agent was added.
Comparative Example 16
[0220] Softanol EP95150 (trademark, product of Nippon Shokubai) was
used for comparison (comparative additive 6).
Comparative Example 17
[0221] Softanol EP7085 (trademark, product of Nippon Shokubai) was
used for comparison (comparative additive 7).
Comparative Example 18
[0222] The dehydration product derived from Tetraguard AS21
(trademark, product of Taiheiyo Cement) as obtained in Production
Example 3 was used for comparison (comparative additive 1).
[0223] The results obtained in Comparative Examples 15 to 18 are
shown in Table 4.
4 Mortar evaluation result Addition Air Additives amount Flow value
content Change in length [.mu.m] Ex. No. used (weight %) (mm)
(volume %) Day 0 Day 3 Day 7 Day 14 Day 21 Day 28 Ex. 7 FC-900 0.12
162.5 1.8 0.0 11.4 34.4 49.0 72.5 85.5 Antiform 0.50 Additive 6
0.50 Ex. 8 FC-900 0.12 173.0 5.2 0.0 11.9 35.4 50.5 69.4 78.5
Antiform 0.50 Additive 7 0.50 Ex. 9 FC-900 0.12 189.0 6.5 0.0 15.4
30.4 57.0 71.4 79.5 Antiform 0.50 Additive 8 0.50 Compar. FC-900
0.12 126.0 0.0 0.0 22.9 67.4 92.5 126.4 141.5 Ex. 15 Antiform 0.50
Compar. FC-900 0.12 124.0 1.8 0.0 20.4 67.9 95.0 117.9 128.0 Ex. 16
Antiform 0.50 Comparative 2.00 additive 6 Compar. FC-900 0.12 167.0
9.8 0.0 20.4 61.4 88.5 108.4 116.5 Ex. 17 Antiform 0.50 Comparative
2.00 additive 7 Compar. FC-900 0.12 118.0 0.0 0.0 23.4 51.9 85.5
107.9 120. 5 Ex. 18 Antiform 0.50 Comparative 2.00 additive 1
[0224] In Example 7 and Example 8, the additive 6 of the invention
was used, which was synthesized starting with Softanol EP95150
(trademark, product of Nippon Shokubai) used in Comparative Example
16 and, in Example 9, the additive 7 of the invention was used,
which was synthesized starting with Softanol EP7085 (trademark,
product of Nippon Shokubai) used in Comparative Example 17. In
Examples 7 to 9, the shrinkage was reduced as compared with
Comparative Example 15 (no addition) or Comparative Example 18 in
which a commercial shrinkage reducing agent (comparative additive
1) was used and, further, the results obtained indicate that the
additives 6 and 7, even when used at an addition amount of not more
than half as compared with Comparative Examples 16 and 17 in which
the starting materials Softanol EP95150 and Softanol EP7085 were
used, respectively, show a higher shrinkage reducing effect than
the effects obtained by using the starting materials as shrinkage
reducing agents.
Production Example 9
[0225] A stainless steel pressure reactor equipped with a
thermometer, a stirrer, a nitrogen inlet tube and a pressure gage
was charged with 177.3 parts of 1,6-hexanediol (product of Wako
Pure Chemical Industries) and 0.3 part of sodium hydroxide. The
pressure reactor inside was purged with nitrogen with stirring, and
the pressure reactor inside was heated to 100.+-.5.degree. C. Then,
493.5 parts of ethylene oxide was introduced into the reactor at a
temperature of 115.+-.7.degree. C. and a safety pressure of
2.0.times.10.sup.-1 to 7.0.times.10.sup.-1 MPa. After maturation,
the volatile matter was removed to give an intermediate
(intermediate c), namely a 1,6-hexanediol-ethylene oxide
adduct.
[0226] The molecular weight of intermediate c was determined based
on its hydroxyl value and found to be 444.1. Thus, the average
number of moles of ethylene oxide added to 1,6-hexanediol was
calculated at 7.4.
[0227] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of the intermediate c and 15.5 parts of maleic acid, and the
charge was heated to 125.+-.5.degree. C. in a nitrogen atmosphere
for melting and mixing up. Then, while maintaining the temperature
at 125.+-.5.degree. C., 14.5 parts of acrylic acid and 2.5 parts of
di-tert-butyl peroxide (trademark Perbutyl D, product of Nippon Oil
and Fat) were individually added dropwise continuously over 1 hour.
Thereafter, stirring was continued at 125.+-.5.degree. C. for 1
hour, to give a graft polymer (graft polymer 9).
[0228] Addition of 68.2 parts of water and 8.7 parts of an aqueous
solution of sodium hydroxide (30% aqueous solution) to 34.7 parts
of the graft polymer 9 gave an aqueous solution of the sodium salt
of graft polymer 9. This is referred to as "additive 9".
[0229] The additive 9 obtained occurred as a pale yellow
transparent solution with a pH of 7.1 and a solid content of 32.1%.
It did not separate for at least 1 month at room temperature.
Production Example 10
[0230] A stainless steel pressure reactor equipped with a
thermometer, a stirrer, a nitrogen inlet tube and a pressure gage
was charged with 92.1 parts of glycerol (product of Wako Pure
Chemical Industries) and 0.1 part of sodium hydroxide. The pressure
reactor inside was purged with nitrogen with stirring, and the
pressure reactor inside was heated to 100.+-.5.degree. C. Then,
264.6 parts of ethylene oxide was introduced into the reactor at a
safety pressure of 3.4.times.10.sup.-1 to 7.0.times.10.sup.-1 MPa
and at a temperature of 112.5.+-.7.5.degree. C. for the initial 50
minutes and thereafter at 145.+-.10.degree. C. After maturation,
the volatile matter was removed to give an intermediate
(intermediate d), namely a glycerol-ethylene oxide adduct.
[0231] The molecular weight of intermediate d was determined based
on its hydroxyl value and found to be 181.4. Thus, the average
number of ethylene oxide added to glycerol was calculated at
2.0.
[0232] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 120.0
parts of the intermediate d and 15.5 parts of maleic acid, and the
charge was heated to 125.+-.5.degree. C. in a nitrogen atmosphere
for melting and mixing up. Then, while maintaining the temperature
at 125.+-.5.degree. C., 14.5 parts of acrylic acid and 3.3 parts of
tert-butylperoxy isopropyl carbonate (trademark Perbutyl I, product
of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
125.+-.5.degree. C. for 1 hour, to give a graft polymer (graft
polymer 10).
[0233] Addition of 69.2 parts of water and 6.6parts of an aqueous
solution of sodium hydroxide (30% aqueous solution) to 30.4 parts
of the graft polymer 10 gave an aqueous solution of the sodium salt
of graft polymer 10. This is referred to as "additive 10".
[0234] The additive 10 obtained occurred as a yellowish brown
transparent solution with a pH of 6.9 and a solid content of 29.2%.
It did not separate for at least 1 month at room temperature.
Production Example 11
[0235] A glass reactor equipped with a thermometer, a stirrer, a
nitrogen inlet tube and a reflux condenser was charged with 129.0
parts of Jeffamine M-2005 (trademark, product of San Techno
Chemical; amine-terminated polyether, average molecular weight
2,000, EO/PO=5/29 (mole ratio)) and 10.9 parts of maleic acid, and
the charge was heated to 125.+-.5.degree. C. in a nitrogen
atmosphere for melting and mixing up. Then, while maintaining the
temperature at 125.+-.5.degree. C., 10.1 parts of acrylic acid and
1.8 parts of di-tert-butyl peroxide (trademark Perbutyl D, product
of Nippon Oil and Fat) were individually added dropwise
continuously over 1 hour. Thereafter, stirring was continued at
125.+-.5.degree. C. for 1 hour, to give a graft polymer (graft
polymer 11).
[0236] Addition of 93.5 parts of water and 10.1 parts of an aqueous
solution of sodium hydroxide (30% aqueous solution) to 51.6 parts
of the graft polymer 11 gave an aqueous solution of the sodium salt
of graft polymer 11. This is referred to as "additive 11".
[0237] The additive 11 obtained occurred as a yellowish brown
turbid solution with a pH of 7.2 and a solid content of 34.1%. Upon
standing at room temperature, a white insoluble matter separated
and rose to the surface. Therefore, prior to use, this additive was
shaken thoroughly until it became homogeneous.
Example 10 to 12
[0238] Using the additives obtained in the above manner, mortar
kneading was performed and test pieces were prepared by the methods
mentioned above and the specimens were evaluated for shrinkage
reducing ability (cracking preventing ability) by measuring the
changes in length. The results are shown in Table 5.
Comparative Example 19
[0239] No shrinkage reducing agent was added.
Comparative Example 20
[0240] The intermediate c obtained in Production Example 9 was used
for comparison (comparative additive 8).
Comparative Example 21
[0241] The intermediate d obtained in Production Example 10 was
used for comparison (comparative additive 9).
Comparative Example 22
[0242] Jeffamine M-2005 (trademark, product of San Techno Chemical)
was used for comparison (comparative additive 10).
Comparative Example 23
[0243] The dehydration product derived from Tetraguard AS21
(trademark, product of Taiheiyo Cement) as obtained in Production
Example 3 was used for comparison (comparative additive 1).
[0244] The results obtained in Comparative Examples 19 to 23 are
shown in Table 5.
5 Mortar evaluation result Addition Air Additives amount Flow value
content Change in length [.mu.m] Ex. No. used (weight %) (mm)
(volume %) Day 0 Day 3 Day 7 Day 14 Day 21 Day 28 Ex. 10 FC-900
0.12 145.0 0.0 0.0 18.0 40.2 82.8 90.5 111.5 Antiform 0.50 Additive
9 0.80 Ex. 11 FC-900 0.12 173.0 0.0 0.0 14.0 34.7 73.3 83.5 90.3
Antiform 0.50 Additive 10 0.50 Ex. 12 FC-900 0.12 156.0 2.6 0.0
12.0 45.2 72.3 99.5 114.0 Antiform 0.50 Additive 11 0.50 Compar.
FC-900 0.12 122.0 0.0 0.0 17.0 54.2 92.8 118.0 132.5 Ex. 19
Antiform 0.50 Compar. FC-900 0.12 122.5 0.0 0.0 9.0 38.2 69.3 93.0
107.5 Ex. 20 Antiform 0.50 Comparative 2.00 additive 8 Compar.
FC-900 0.12 115.5 0.0 0.0 18.5 49.2 80.3 108.0 125.5 Ex. 21
Antiform 0.50 Comparative 2.00 additive 9 Compar. FC-900 0.12 112.5
0.0 0.0 15.0 40.2 82.8 90.5 111.5 Ex. 22 Antiform 0.50 Comparative
2.00 additive 10 Compar. FC-900 0.12 Ex. 23 Antiform 0.50 120.0 0.0
0.0 15.5 42.2 70.8 97.5 113.0 Comparative 2.00 additive 1
[0245] In Example 10, the additive 9 of the invention was used,
which was synthesized starting with the intermediate c used in
Comparative Example 20 and, in Example 11, the additive 10 of the
invention was used, which was synthesized starting with the
intermediate d used in Comparative Example 21. In Example 12, the
additive 11 of the invention was used, which was synthesized
starting with Jeffamine M-2005 (trademark, product of San Techno
Chemical) used in Comparative Example 22. In Examples 10 to 12, the
shrinkage was reduced as compared with Comparative Example 19 (no
addition) or Comparative Example 23 in which a commercial shrinkage
reducing agent (comparative additive 1) was used and, further, the
results obtained indicate that the additives 9, 10 and 11, even
when used at an addition amount of not more than half as compared
with Comparative Examples 20 to 22 in which the starting materials,
namely the intermediate c, intermediate d and Jeffamine M-2005
(trademark, product of San Techno Chemical), were used,
respectively, show a higher shrinkage reducing effect than the
effects obtained by using the starting materials as shrinkage
reducing agents.
(Simplified water reduction evaluation)
[0246] Ordinary portland cement (400 g, product of Taiheiyo Cement)
and 800 g of standard Toyoura sand were dry-mixed in a Hobart type
mortar mixer (model N-50 (trademark), product of Hobart) for 30
seconds and, then, 240 g of an additive mixture prepared by
diluting the additives specified in Table 2, each weighed as
specified in Table 2, with water, followed by 3 minutes of kneading
at an intermediate speed to give a mortar sample.
[0247] The mortar obtained was immediately filled into a stainless
steel hollow cylinder with an inside diameter of 53.5 mm and a
height of 50 mm as placed on a horizontal table to the top level of
the cylinder, this cylinder was gently lifted up, and the major
axis and minor axis of the mortar spread over the table were
measured with vernier calipers. The mean value thereof was reported
as the mortar flow value. When the amount of air entrained is
large, flow and shrinkage values are apparently exaggerated and
therefore the amount of air entrained should be constant. Thus, an
appropriate amount of an air entraining agent (e.g. Yamaso Kagaku's
Vinsol (trademark)) or a defoaming agent was used.
[0248] The amount of air was calculated based on the mortar volume
and weight and the ratio of the materials used. The results
obtained are shown in Table 6.
6TABLE 6 Addition Flow Air amount* value content Ex. No. Additives
used (wt. %) (mm) (vol. %) Ex. 13 Additive 1 0.5 74 16.8 Ex. 14
Additive 3 0.5 68 9.8 AE agent 0.1 Compar. AE and high-range 0.12
110 9.7 Ex. 24 water reducing agent *The addition amounts are on
the solid content basis relative to cement.
[0249] The AE agent used was Vinsol (product of Yamaso Kagaku).
[0250] Table 7 shows concrete mix proportions. The amount of the
air entraining and high-range water reducing agent required to
attain an equal slump value upon formulation change from the
admixture-free plain concrete (formulation 1) to the formulation
with the unit water content being reduced by 18% (formulation 2)
was 0.12%. The fine aggregate used was Oi river system land sand
(specific gravity 2.60, fineness modulus=2.70), the coarse
aggregate used was crushed Oume stone (specific gravity 2.65,
maximum size 20 mm) and the cement used was Taiheiyo Cement's
ordinary portland cement (specific gravity 3.16).
7 TABLE 7 Quantity per unit volume of concrete (kg/m.sup.3) W/C s/a
Fine Coarse Formulation (%) (%) Cement Water aggregate aggregate 1
65.6 50 320 210 883 869 2 53.8 49 320 172 875 897
[0251] In Comparative Example 24, Aqualoc FC-900 was used as an air
entraining and high-range water reducing agent in an amount of
0.12% (relative to cement). For reducing the unit water content in
concrete by 18%, 0.12% (relative to cement) of Aqualoc FC-900 was
required. When this addition amount was applied to the
above-mentioned mortar, a flow value of 110 mm and an air content
of 11.+-.2% by volume were attained and homogeneous mortar was
obtained.
[0252] In Example 13, the water reducing ability of the additive 1
was evaluated by the simplified mortar test. When the additive 1
was used in an amount of 0.5% (relative to cement), the flow was
only 74 mm and it was thus revealed that the addition amount
required to attain 18% water reduction is not less than 0.5% or
that the additive cannot attain 18% water reduction at all.
[0253] In Example 14, the water reducing ability of the additive 3
was evaluated by the simplified mortar test. When the additive 3
was used in an amount of 0.5% (relative to cement), the flow was
only 68 mm and it was thus revealed that the addition amount
required to attain 18% water reduction is not less than 0.5% or
that the additive cannot attain 18% water reduction at all.
[0254] Based on these data, it was confirmed that the additives of
the present invention produce an excellent shrinkage reducing
effect but have no water reducing ability or, if they have such
ability, the ability will be slight.
* * * * *