JP3537731B2 - Concrete admixture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a concrete admixture.

[0002]

2. Description of the Related Art As a concrete admixture, a copolymer produced from a polyalkylene glycol mono (meth) acrylate monomer and a (meth) acrylate monomer is known.

In this type of copolymer, an addition mole number (hereinafter referred to as n) of alkylene oxide (hereinafter referred to as AO) is used.
It is disclosed that characteristic performance can be imparted by changing the monomer ratio.
For example, JP-A-7-223852 describes that when a monomer having n larger than 110 is used, the dispersibility is excellent. Japanese Patent Application Laid-Open No. 9-328345 describes that when a monomer having n larger than 110 is used, the initial strength after steam curing is good.

Further, there is disclosed a technique relating to a polycarboxylic acid cement dispersant obtained by mixing two or more kinds of polycarboxylic acid cement dispersants having different n or copolymerizing two or more monomers having different n. ing. For example, JP-A-7-2
No. 47150 discloses a dispersant in which monomers in which n is 110 to 300 and 1 to 30 are copolymerized. Japanese Patent Application Laid-Open No. 9-40446 discloses that n is 100 to 300 and 1 to 3
There is disclosed a mixture of a copolymer obtained by copolymerizing 0 monomers. Japanese Patent Application Laid-Open No. 9-286645 describes that n
Is a polycarboxylic acid cement dispersant obtained from a monomer containing two types of monomers different from each other in the range of 3 to 97 and 1 to 100, and the two types of monomers are separately copolymerized. A polycarboxylic acid cement dispersant comprising a mixture of the obtained copolymers is disclosed.

[0005]

In a concrete manufacturing site, the mixing conditions vary widely, and the temperature of the working environment fluctuates in a wide range throughout the year. However, the above technique is extremely low in general versatility. Further, the polycarboxylic acid-based concrete admixture using a monomer having a short AO chain in which n is less than 110 is smaller than the polycarboxylic acid-based concrete admixture using a monomer having a longer AO chain. Low initial strength.

An object of the present invention is to provide a concrete admixture which exhibits a high level of dispersibility, dispersion retention and initial strength under a wide range of concrete production conditions.

[0007]

The present invention provides a monomer (a) represented by the following general formula (1) and a monomer (a) represented by the following general formula (2):
And / or the monomer (b) represented by (3)
Copolymer (I) obtained from a monomer mixture containing [(a) + (b)] × 100 = 1 to 30 (% by weight)
And the monomer (a) and the monomer (b) as (b) /
[(A) + (b)] × 100 = 1 to 30 (wt%) and a copolymer (II) obtained from a monomer mixture containing the copolymer (I) in a different ratio from the above-mentioned copolymer (I) And a concrete admixture containing:

[0008]

Embedded image

[In the formula (1), R ¹ , R ² : hydrogen atom or methyl group R ³ : oxyalkylene group having 2 to ³ carbon atoms R ⁴ : hydrogen atom or alkyl group having 1 to 3 carbon atoms m: 0 N represents the number of 110 to 300. ]

[0010]

Embedded image

[In the formula (2), R ⁵ , R ⁶ , R ^{7 are a} hydrogen atom, a methyl group or (CH ₂ ) _p COOX ² , and (CH ₂ ) _p
COOX ² may form an anhydride with COOX ¹ or another (CH ₂ ) _p COOX ² , in which case the X of those groups
Does not exist. X ¹ , X ² : hydrogen atom, alkali metal, alkaline earth metal, ammonium group, alkylammonium group or substituted alkylammonium group p: represents the number of 0 to 2. ]

[0012]

Embedded image

[In the formula (3), R ^{8 represents a} hydrogen atom or a methyl group Y: represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkylammonium group or a substituted alkylammonium group. ]

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer (a) represented by the general formula (1) includes methoxy polyethylene glycol, methoxy polyethylene polypropylene glycol, ethoxy polyethylene glycol, ethoxy polyethylene polypropylene glycol, propoxy polyethylene glycol, and propoxy polyethylene polypropylene. Esterified products of a polyalkylene glycol having one end alkyl-blocked, such as glycol, and a dehydrogenation (oxidation) reaction product of acrylic acid, methacrylic acid, and fatty acid. Further, AO of a dehydrogenation (oxidation) reaction product of acrylic acid, methacrylic acid, and fatty acid, preferably an ethylene oxide or propylene oxide adduct may be used.

In order to secure the initial strength, the average number of moles of AO added in the general formula (1) must be 110 or more. On the other hand, when n is larger than 300, the dispersibility decreases, and the polymerizability during production also decreases. For this reason n
Is in the range of 110 to 300, and more preferably n is 110 to 200.

Among the monomers (b), the monomers represented by the general formula (2) include monocarboxylic acid monomers such as (meth) acrylic acid and crotonic acid, salts thereof, and maleic acid. Examples include dicarboxylic acid monomers such as acid, itaconic acid, fumaric acid, and citraconic acid, and anhydrides or salts thereof. Salts include alkali metal salts, alkaline earth metal salts, ammonium salts, monovalent hydroxyl groups which may be substituted,
Di, trialkyl (C2-8) ammonium salts are preferred. Of these, preferably (meth) acrylic acid,
Maleic acid, maleic anhydride or a salt thereof, more preferably methacrylic acid or an alkali metal salt thereof.

Examples of the monomer represented by the general formula (3) include allylsulfonic acid, methallylsulfonic acid and salts thereof. The salt is preferably an alkali metal salt, an alkaline earth metal salt, an ammonium salt, or a mono-, di-, or trialkyl (C2-8) ammonium salt whose hydroxyl group may be substituted.

In the present invention, the ratio of the monomers (a) and (b) (hereinafter referred to as the ratio (b) / [(a) + (b)]) is (b) / [(a) + (b) )] × 100 = 1 to 30% by weight, preferably 1 to 20% by weight, more preferably 2 to 1% by weight.
5% by weight of a copolymer (I) obtained from a monomer mixture and a monomer having a (b) / [(a) + (b)] ratio in the above-mentioned range and different from the copolymer (I) And a copolymer (II) obtained from a polymer mixture. Here, the copolymer (I)
And (II), (b) / [(a) +
(B)] A plurality of copolymers obtained from a plurality of monomer mixtures having different ratios can be used. From a practical point of view, 2 to 4 having different (b) / [(a) + (b)] ratios
It is preferred to use 2 to 4 copolymers, each obtained from one monomer mixture. (B) / [(a) +
(B)] Since a large number of copolymers having different ratios are present, good dispersibility and dispersion retention are exhibited over a wide range of W / C and concrete temperature. In particular, the dispersion retention for a long time becomes stable. As a result, the concrete admixture can sufficiently cope with fluctuations in W / C and fluctuations in temperature. In each of the monomer mixtures, the monomers (a) and (b) were 2
It is also possible to use more than one species, in which case (b) /
[(A) + (b)] ratio is calculated by the total amount of each monomer.

In the present invention, in the monomer mixture for obtaining the copolymers (I) and (II), (b) / [(a)
+ (B)] the difference is at least 0.5 (% by weight),
In particular, it is preferably at least 1 (% by weight), more preferably at least 2 (% by weight), from the viewpoint of maintaining the dispersibility against environmental changes.

In the present invention, the copolymer (I), the copolymer (II), and the copolymer (I) are different from the copolymers (I) and (II) (b).
/ [(A) + (b)] in the case of using three copolymers of a copolymer [conveniently referred to as copolymer (III)],
A copolymer having a (b) / [(a) + (b)] ratio of 1 to 5% by weight, a copolymer having a (b) / [(a) + (b)] ratio of 4 to 10% by weight, and (B) / [(a) + (b)] ratio is 6 to 30
It is preferable to use a copolymer having a ratio of (b) / [(a) + (b)] of at least 0.5 (% by weight), more preferably at least 1 (% by weight), particularly 2 (%). % By weight) or more.

In obtaining the copolymer of the present invention, in addition to the monomers (a) and (b), a monomer (c) copolymerizable therewith may be used. As the monomer (c), an ester of an aliphatic alcohol having 1 to 20 carbon atoms and (meth) acrylic acid, (meth) acrylamide, maleic acid or fumaric acid and an aliphatic alcohol having 1 to 20 carbon atoms And monoesters or diesters of maleic acid or fumaric acid with glycols having 2 to 4 carbon atoms, maleic acid or fumaric acid and addition mole numbers of 2 to 3
Monoesters or diesters with 00 polyalkylene glycols, alkenyl acetates such as vinyl acetate and propyl acetate, aromatic vinyls such as styrene and p-methylstyrene, and vinyl chloride. These are 2
More than one species may be used. The monomer (c) is 50% by weight or less based on the total of the monomers (a) and (b), and 3% or less.
It is preferably used at a ratio of 0% by weight or less, particularly 0% by weight.

The concrete admixture of the present invention comprises a total of 50% by weight or more, more preferably 80% by weight or more of two or more copolymers having different ratios of (b) / [(a) + (b)]. ,
Particularly, it is preferable to contain 100% by weight.

The concrete admixture of the present invention can also contain other additives (materials). For example,
Resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, alkylbenzene sulfonic acid (salt), alkane sulfonate, polyoxyalkylene alkyl (phenyl) ether, polyoxyalkylene alkyl (phenyl) ether sulfate (salt), A such as polyoxyalkylene alkyl (phenyl) ether phosphate (salt), protein material, alkenyl succinic acid, α-olefin sulfonate, etc.
E agent; oxycarboxylic acids such as gluconic acid, glucoheptonic acid, arabonic acid, malic acid, and citric acid; dextrins; saccharides such as monosaccharides, oligosaccharides and polysaccharides; and retarders such as sugar alcohols; A thickener; silica sand; an AE water reducing agent;
Calcium chloride, calcium nitrite, calcium nitrate,
Soluble calcium salts such as calcium bromide and calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfates,
Potassium hydroxide, sodium hydroxide, carbonate, thiosulfate, formic acid (salt), fast-acting agents or accelerators such as alkanolamines; blowing agents; resin acids (salts), fatty acid esters, oils and fats,
Waterproofing agents such as silicone, paraffin, asphalt, and wax; blast furnace slag; fluidizing agents; defoaming agents such as dimethylpolysiloxane, polyalkylene glycol fatty acid ester, mineral oil, oil and fat, oxyalkylene, alcohol, and amide Agent; antifoaming agent; fly ash; melaminesulfonic acid formalin condensate, aminosulfonic acid,
High-performance water reducing agents such as polycarboxylic acids and polymaleic acids; silica fume; rust inhibitors such as nitrites, phosphates and zinc oxide; celluloses such as methylcellulose and hydroxyethylcellulose; β-1,3-glucan Water-soluble polymers such as natural products such as glycerol, xanthan gum, and synthetic systems such as polyacrylamide, polyethylene glycol, ethylene oxide adduct of oleyl alcohol or a reaction product thereof with vinylcyclohexene diepoxide; (meth)
A polymer emulsion such as an alkyl acrylate may be used.

The concrete admixture of the present invention can be used for self-leveling, refractories, plasters, gypsum slurries, lightweight or heavy concrete, AE, repair, prepacked, in addition to fresh concrete and concrete vibration products. It is useful in any field of various concretes, such as for trays, for grout, for cold and so on.

[0025]

EXAMPLES <Production Example> 520 parts by weight of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the atmosphere was replaced with nitrogen. Subsequently, the temperature was raised to 80 ° C. in a nitrogen atmosphere, and a mixture of 653.5 parts by weight of a 60% aqueous methoxypolyethylene glycol methacrylate solution (average number of moles of ethylene oxide added: 120) and 9.1 parts by weight of methacrylic acid was mixed with 15% Three liquids of 11.0 parts by weight of a 2-mercaptoethanol aqueous solution and 16.2 parts by weight of a 15% ammonium persulfate aqueous solution were simultaneously dropped,
The dropping of all three liquids was completed in 90 minutes. Next, 15%
8 parts by weight of an aqueous solution of ammonium persulfate was added dropwise over 30 minutes, and the mixture was aged at 80 ° C. for 2 hours. Further, the mixture was neutralized by adding 6.2 parts by weight of a 48% aqueous sodium hydroxide solution.
4.1 parts by weight of aqueous hydrogen peroxide solution were added, and the mixture was kept at 90 ° C. for 1 hour and then cooled, and the copolymer PE1 (120,
2.88). Further, the types of the monomers (a) and (b), the amount of the initiator, and the like were adjusted, and the copolymer shown in Table 1 was obtained in the same manner as above.

[0026]

[Table 1]

(Note) (1) In the parentheses of the copolymer, the EO of the monomer (a) is in order.
Mean number of moles added, (b) / [(a) + (b)] ratio. For example, PE1 (120, 2.88) has an average EO addition mole number of the monomer (a) of 120 and (b) /
[(A) + (b)] means a copolymer having a ratio of 2.88% by weight. (2) The symbols in the table have the following meanings. • MPEGMM: methoxypolyethylene glycol monomethacrylate • MAA: methacrylic acid • AA: acrylic acid • MA: maleic acid • AM: methyl acrylate

<Concrete test conditions> (1) Material W = tap water C = ordinary Portland cement (specific gravity = 3.16) LS = limestone fine powder (specific gravity = 2.70, Blaine value = 5)
200) Fine aggregate = Kinto Kimitsu (specific gravity = 2.63) Coarse aggregate = Ibaraki fine bone (specific gravity = 2.62) W / C = (unit weight of W / unit weight of C) × 100% s / A = (fine aggregate volume / (fine aggregate volume + coarse aggregate volume))
× 100% (2)

[0029]

[Table 2]

(3) Kneading conditions The material and dispersant for 30 liters of concrete are forcibly mixed.
It is put into a shaft mixer (50 liters), kneaded for 90 seconds, and the performance immediately after discharge (initial slump value, initial slump flow value) and the slump flow value after 15, 30, and 60 minutes are measured.

The slump test was conducted according to JIS-A1101, the slump flow value was determined by the Japan Society of Civil Engineers, “Guidelines for Construction of High Fluidity Concrete” (concrete library 93), and the compressive strength was determined according to J.
It carried out according to IS-A1132 / A1108.

(4) The concrete after the curing conditions were discharged was subjected to a compression test form (specimen diameter 1).
0 cm, test specimen height 20 cm), allowed to stand at room temperature for 30 minutes, and then subjected to steam curing at 65 ° C. × 4 hours. After leaving at 20 ° C. for 1 hour after steam curing, the compressive strength of the test specimen is measured.

(5) Test method (5-1) Comparative examples 1 to 4, Examples 1 to 5 Concrete compositions A-1 and A-2 shown in Table 2 were tested at a room temperature of 20 ° C. Dispersibility and retention were measured by the following methods. Table 3 shows the results. In addition, in Table 3, Example 1
It is out of the scope of the present invention, but shown as a reference example.
You. Dispersibility: The rate of addition of the dispersant solids to the total powder required for the initial slump value to be 20 ± 1 cm. The smaller the value, the better the dispersibility. Retention: the percentage of the slump value after 30 minutes relative to the initial slump value. The larger the value, the better the dispersion retention.

(5-2) Comparative Examples 5 to 7 and Examples 6 to 13 For the composition B in Table 2, a CT (concrete temperature) of 20
C was carried out at room temperature of 18 ° C, and CT was carried out at room temperature of 30 ° C. Dispersibility and retention were measured by the following methods. Table 4 shows the results. Dispersibility: The rate of addition of the dispersant solid to the total powder required for the initial slump flow to be 675 ± 25 mm. The smaller the value, the better the dispersibility. Retention: Percentage of slump value after 30 minutes to initial slump flow value. The larger the value, the better the dispersion retention.

(5-3) Comparative Example 8, Examples 14 to 16 The compound B of Table 2 was used at room temperature of 20 ° C. Dispersibility and retention were measured by the following methods. Table 5 shows the results. Dispersibility: The rate of addition of the dispersant solid to the total powder required for the initial slump flow to be 600 ± 25 mm. The smaller the value, the better the dispersibility. Retention: 15, 30, relative to the initial slump flow value
Percent of slump value after 60 minutes. The larger the value, the better the dispersion retention.

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

As shown in Comparative Example 1, PE1 (12
0,6.01) is dispersibility at W / C = 36.9%,
The retention is standard, but at W / C = 32.1%,
The dispersibility is greatly reduced, and the slump value after 30 minutes is greatly increased as compared with the initial slump value. Since it is desirable that the slump value gradually decrease with time, PE1
(120, 6.01) shows that at low W / C, both dispersibility and retention deteriorate.

From Comparative Example 2, PE1 (120, 8.3)
In 1), although the dispersibility was good at W / C = 36.9%, the retention was poor, and the retention was insufficient even at W / C = 32.1%.

From Comparative Example 3, PE1 (120, 2.8)
In the case of 8), the dispersibility was poor at W / C = 36.9%, the retention was also increased with time, and when W / C = 32.1%, these performances were further reduced.

From Comparative Example 4, PE1 (120, 6.0)
PE1 having a small number of moles of EO added (9, 20.6
When 4) is blended, the retention is stable with respect to the fluctuation of W / C, but the dispersibility is low, and the steam curing strength is greatly reduced.

On the other hand, as in the first embodiment, PE1
When PE1 (120, 6.79) was blended with (120, 6.01), the properties were almost the same at W / C = 36.9% as compared with Comparative Example 1, and at W / C = 32.1%. It can be seen that both the dispersibility and the retention were improved, and the steam curing strength was also equivalent.

From Examples 2 to 4, W / W was higher than that of Example 1.
It can be seen that the dispersibility / retention is more stable with respect to the variation in C.

From Example 5, it can be seen that the three-compound system of the copolymer according to the present invention is more stable in dispersibility / retention with respect to fluctuations in W / C than in Examples 2 to 4. Understand.

From Comparative Examples 5 to 7 and Examples 6 to 13, similarly, the concrete has a more stable dispersibility and a holding property and a steam curing strength of 1 against the fluctuation of the concrete temperature as compared with the comparative example.
It can be seen that when 10 ≦ n, it is at the same level as Comparative Example 6 of the single system.

From Comparative Example 8 and Examples 14 to 16, it can be seen that, compared to Comparative Example, Example 14 of the three compounding system has a stable retention after 30 minutes. Examples 15 and 16 of 4 compound system
Indicates that the retention is more stable than that of the three-compound system, including the retention after 15 minutes.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Wa Fuji Sakura 1334 Minato 1334 Kato, Wakayama, Wakayama Pref.Inventor Koji Koyanagi 1334 Minato 1334 Minato Wakayama, Wakayama Pref. JP 2001-180998 (JP, A) JP 11-335150 (JP, A) JP 11-268940 (JP, A) JP 11-106249 (JP, A) JP 9-286645 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 24/26 C04B 24/32

Claims (1)

(57) [Claims] 1. A monomer (a) represented by the following general formula (1) and a monomer (b) represented by the following general formulas (2) and / or (3) are converted into (b) / [ (A) + (b)] × 10
The copolymer (I) obtained from the monomer mixture containing 0 = 1 to 30 (% by weight) and the monomer (a) and the monomer (b) are (b) / [ (A) + (b)] × 10
And a copolymer (II) obtained from a monomer mixture having a ratio of 0 to 1 (% by weight) and a different ratio from the copolymer (I). )as well as
The difference in the ratio in the monomer mixture for obtaining (II)
A concrete admixture having a wrinkle of at least 2 (% by weight) . Embedded image [In the formula (1), R ¹ , R ² : hydrogen atom or methyl group R ³ : oxyalkylene group having 2 to ³ carbon atoms R ⁴ : hydrogen atom or alkyl group having 1 to 3 carbons m: 0 to 2 Number n: represents a number from 110 to 300. [Chemical formula 2] [In the formula (2), R ⁵ , R ⁶ , R ⁷ : a hydrogen atom, a methyl group or (CH ₂ ) _p CO 2
OX ² and (CH ₂ ) _p COOX ² is COOX ¹ or another
An anhydride may be formed with (CH ₂ ) _p COOX ² , in which case X in those groups is absent. X ¹ , X ² : hydrogen atom, alkali metal, alkaline earth metal, ammonium group, alkylammonium group or substituted alkylammonium group p: represents the number of 0 to 2. [Chemical formula 3] [In the formula (3), R ^{8 represents a} hydrogen atom or a methyl group Y: represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkylammonium group or a substituted alkylammonium group. ]