JPH0210110B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a cement mortar or concrete that provides a high-strength cured product with excellent freeze-thaw resistance, and more specifically, it provides a cement mortar or concrete that provides a high-strength cured product with excellent freeze-thaw resistance. It is about the method. [Prior art] In recent years, fluidized concrete has attracted attention in the architectural and civil engineering fields in order to streamline concrete pouring work and improve the quality of poured concrete.
Along with this, superplasticizers have come into the spotlight. However, naphthalene sulfonic acid formalin condensate salt, which is often used as a fluidizing agent, has a problem in that when applied to fluidized concrete, the consistency changes over time, that is, the so-called slump loss is large. As a method for preventing this slump loss, compounds have been proposed that have both dispersion performance in cement and slump loss prevention performance. For example, JP-A-51-10834, JP-A-51-
No. 101024, JP-A-57-118058, JP-A-58-
No. 74552, JP-A-60-60963, JP-A-60-103062
Various polycarboxylic acid-based cement dispersants are disclosed in the following publications. [Problems to be solved by the invention] However, all of these polycarboxylic acid-based cement dispersants have air entrainment properties in addition to cement dispersion performance and slump loss prevention performance. This reduces the performance of the resulting fluidized concrete. That is, unlike the so-called AE water reducer when preparing ready-mixed concrete with a conventional low water reduction rate, fluidized concrete
It is necessary to use a large amount of these polycarboxylic acid-based cement dispersants in order to greatly reduce the unit amount of water in order to prevent cracking after hardening and increase strength, and as a result, the amount of air entrained becomes excessive. However, there was a problem in that the strength decreased after curing. Antifoaming agents are also used to adjust the amount of air entrained, but in this case the problem is that the air bubbles entrained in cement mortar or concrete become coarser in diameter, reducing freeze-thaw resistance. It was hot. In view of the current situation, the present inventors conducted extensive research and arrived at the present invention. Therefore, the object of the present invention is to use a polycarboxylic acid polymer as a high-performance fluidizing agent for addition to a ready-mixed concrete plant or as a cement dispersant for preparing high-strength cement mortar and concrete with few cracks. To provide a method for imparting excellent properties in terms of freeze-thaw resistance and strength to cement mortar and concrete after hardening, by making entrained air bubbles of good quality and adjusting the amount of entrained air to an appropriate amount when used. There is a particular thing. [Means and effects for solving the problems] The present invention is based on the general formula (a) (However, R ¹ represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, l and m are each independently a positive integer of 1 or more, and 5≦l+m≦50
It satisfies the following. ) A water-soluble polycarboxylic acid polymer containing as essential components an ethylene oxide derivative of a primary amine () and a structural unit represented by the following general formula (b) and a structural unit represented by the general formula (c).
The weight ratio of primary amine ethylene oxide derivative ()/water-soluble polycarboxylic acid polymer () =
The present invention relates to a method for adjusting the amount of air entrained in cement mortar or concrete, which is used at the time of mixing cement mortar or concrete at a ratio of 0.1/100 to 10/100. (Record) (However, X represents hydrogen, a methyl group or -CH ₂ COOZ, Y represents hydrogen, a methyl group or -COOZ, and Z represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or the general formula (a)) Represents an organic amine group excluding the ethylene oxide derivative () of the expressed primary amine.) [However, R ² represents hydrogen or a methyl group, A is hydrogen, an alkyl group having 1 to 23 carbon atoms, an aryl group, an alkylaryl group, a sulfonated aryl group, -OR ³ , -CH ₂ OR ³ , - COOR ³ , -COO-(
D-O-) _o R ⁴ or -CH ₂ -O-(D-O-) _o R ⁴ (R ³ is an alkyl group with 1 to 5 carbon atoms, D is an alkyl group with 2 carbon atoms
to 4, R ⁴ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and n is a positive integer of 1 to 100. ] The ethylene oxide derivative () of a primary amine used in the present invention is obtained by adding ethylene oxide to a primary amine having an alkyl group or an alkenyl group having 8 to 22 carbon atoms using a conventional method without a catalyst or with an alkali catalyst. It can be obtained by The number of moles (l+m) of ethylene oxide added to the primary amine is in the range of 5 to 50, and if this number of moles added is less than 5 moles, the water solubility of the ethylene oxide derivative () of the primary amine is insufficient and air is entrained. The amount adjustment function is not fully utilized. On the other hand, if it is larger than 50 moles, the water solubility becomes excessive and the ability to adjust the amount of entrained air decreases due to a decrease in the primary amine portion per unit weight. The water-soluble polycarboxylic acid polymer () used in the present invention is a polymer containing as essential components a structural unit represented by the general formula (b) and a structural unit represented by the general formula (c), For example, α-olefin/maleic anhydride copolymer and its derivatives,
Styrene/maleic anhydride copolymer and its derivatives, (meth)allyl ether/maleic anhydride copolymer and its derivatives, sulfonated styrene/maleic anhydride copolymer and its derivatives,
Sulfonated styrene/(meth)acrylic acid copolymer, (meth)acrylic acid ester/(meth)acrylic acid copolymer, (meth)acrylic acid oxyalkyl ester/(meth)acrylic acid copolymer, (meth) Examples include acrylic acid polyalkylene glycol monoester/(meth)acrylic acid copolymer. In the present invention, the ethylene oxide derivative of primary amine () and the water-soluble polycarboxylic acid polymer () are used in a specific weight ratio of 0.1/100 to 10/100. It is possible to adjust the amount of entrained air to an appropriate amount when a large amount of polycarboxylic acid polymer () is added to fluidized concrete without impairing its inherent cement dispersion performance, and it can also be used in cement mortar and concrete. The air bubbles entrained inside can be made of high quality, and the final result is cement mortar and concrete that provide a high-strength hardened product with excellent freeze-thaw resistance. In this way, by simply using ethylene oxide derivatives of primary amines () and water-soluble polycarboxylic acid polymers () in a specific ratio, it is possible to entrain good quality and appropriate amounts of air bubbles, while also creating high-strength cement mortars and concrete. It's amazing what you can get. The ratio of primary amine ethylene oxide derivative ()/water-soluble polycarboxylic acid polymer () is 0.1/
If it is smaller than 100, the amount of entrained air will be too large or the bubbles will become coarse, resulting in a lack of bubble stability.If it is larger than 10/100, the ethylene oxide derivative of the primary amine will result. The effect of () as an air entraining agent is expressed, and the water-soluble polycarboxylic acid polymer () exhibits an air entrainment property equal to or greater than that when used alone, and both achieve the purpose of the present invention. I can't. In the present invention, in order to use the ethylene oxide derivative of primary amine () and the water-soluble polycarboxylic acid polymer (), they may be mixed before preparing cement mortar or concrete, or they may be kneaded. Even if added with water during kneading,
Alternatively, each may be added separately during kneading. In particular, when mixing the ethylene oxide derivative of the primary amine () and the water-soluble polycarboxylic acid polymer () in advance, the oxidation of the primary amine is Adding an ethylene derivative () makes it possible to obtain a homogeneous aqueous solution, which is desirable for handling. [Effects of the Invention] In the present invention, by using a specific ethylene oxide derivative of a primary amine () and a water-soluble polycarboxylic acid polymer () together in a specific ratio, the water-soluble polycarboxylic acid polymer ( ) without impairing its inherent cement dispersion performance, the amount of entrained air can be adjusted to an appropriate amount when a large amount of this is added to fluidized concrete, etc., and the entrained air bubbles are fine, stable, and of high quality. be able to. Therefore, according to the method of the present invention, it is possible to impart excellent properties in terms of freeze-thaw resistance and strength to cement mortar and concrete after hardening. It can be effectively applied to preparation. [Examples] Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, unless otherwise specified in the examples,
Parts represent parts by weight, and % represents weight %. Reference Example 1 390 parts of isopropyl alcohol (hereinafter abbreviated as IPA) was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a gas introduction tube, and a reflux condenser, and the inside of the reaction vessel was heated with nitrogen while stirring. The mixture was evaporated and heated to boiling point under a nitrogen atmosphere. Then methoxypolyethylene glycol monomethacrylate (“NK
-Ester M-9G" manufactured by Shin Nakamura Chemical Co., Ltd., a mixture consisting of 133 parts of ethylene oxide (average number of added moles of 9), 27 parts of methacrylic acid, 2.44 parts of benzoyl peroxide and 240 parts of IPA was added in 120 minutes,
After the addition was completed, 0.49 parts of benzoyl peroxide dispersed in 10 parts of IPA was added in two portions every 30 minutes. After the monomer addition was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, 50 mol% of the methacrylic acid used was neutralized with an aqueous sodium hydroxide solution, and IPA was distilled off.
Further, post-neutralization was performed with an aqueous sodium hydroxide solution so that the pH of the aqueous copolymer solution became 7.0, to obtain an aqueous solution of copolymer (1). The viscosity of a 40% aqueous solution of this copolymer (1) was as shown in Table 1. Reference example 2 354 parts of IPA was charged in the same reaction vessel as in reference example 1,
The inside of the reaction vessel was purged with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. Next, a mixture consisting of 56 parts of hydroxyethyl acrylate, 104 parts of acrylic acid, 7.7 parts of benzoyl peroxide, and 240 parts of IPA was added over 120 minutes, and after the addition was completed, 30 parts of a mixture of 1.9 parts of benzoyl peroxide dispersed in 37 parts of IPA was added. Addition was made in two portions, each minute apart. After the monomer addition was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, 50 mol% of the acrylic acid used was neutralized with an aqueous sodium hydroxide solution, and IPA was distilled off. Further, the aqueous copolymer solution was post-neutralized with an aqueous sodium hydroxide solution so that the pH of the aqueous copolymer solution became 7.0, to obtain an aqueous solution of copolymer (2). The viscosity of a 40% aqueous solution of this copolymer (2) was as shown in Table 1. Reference Example 3 In the same reaction vessel as in Reference Example 1, 334 parts of polyethylene glycol monoallyl ether (containing an average of 5 ethylene oxide units per molecule) and water were added.
100 parts of the reactor was charged, the inside of the reaction vessel was purged with nitrogen while stirring, and the mixture was heated to 95°C in a nitrogen atmosphere. Thereafter, an aqueous solution of 139.3 parts of maleic acid and 14.2 parts of ammonium persulfate dissolved in 225 parts of water was added over 120 minutes. After the addition was completed, 14.2 parts of a 20% aqueous ammonium persulfate solution was further added over 20 minutes. 95 for 100 minutes after completion of addition
The temperature in the reaction vessel was maintained at 0.degree. C. to complete the polymerization reaction. Thereafter, the aqueous copolymer solution was neutralized with an aqueous sodium hydroxide solution so that the pH of the aqueous copolymer solution became 7.0, to obtain an aqueous solution of copolymer (3). 40% of this copolymer (3)
The viscosity of the aqueous solution was as shown in Table 1. Reference example 4 Maleic anhydride was placed in an autoclave equipped with a thermometer protection tube, a stirrer, a gas introduction tube, and a purge tube.
98 parts, 6 parts of benzoyl peroxide, and 400 parts of benzene were charged, and the atmosphere was replaced with nitrogen. Next, the mixture was heated to 70 to 75° C. with stirring, and a polymerization reaction was carried out for 7 hours while introducing 60 parts of butene-1. Thereafter, the precipitated copolymer was separated, washed with benzene, and then dried to obtain 120 parts of a copolymer.
This was dissolved and neutralized in an aqueous sodium hydroxide solution so that the pH of the aqueous copolymer solution was 7.1, to obtain an aqueous solution of copolymer (4). The viscosity of a 40% aqueous solution of this copolymer (4) was as shown in Table 1.

[Table] Example 1 Ordinary Portland cement (manufactured by Sumitomo Cement Co., Ltd.) was used as cement, river sand from Yodogawa (specific gravity 2.5) as fine aggregate, crushed stone from Takatsuki (specific gravity 2.68) as coarse aggregate, and Suita City tap water as water. , unit cement amount 320Kg/m ³ , unit water amount 170Kg/m ³ (water/cement ratio 53%), unit fine aggregate amount 813Kg/m ³ , unit coarse aggregate amount
With a mix of 979Kg/m ³ (fine aggregate ratio 47%), each material was weighed so that the mixing amount was 30.
All ingredients were placed in a tilting mixer. In addition, the copolymer () obtained in Reference Example 1 was added to the mixing water so that the solid content was 0.20% based on cement, and the average number of moles of ethylene oxide added per molecule of laurylamine was 15 moles. The obtained adduct (hereinafter referred to as laurylamine EO 15 mole adduct) was mixed in advance at a ratio of 0.005% to cement. Immediately after adding the materials, they were mixed for 33 minutes to prepare concrete. The slump, air content, and compressive strength of the resulting concrete were measured according to Japanese Industrial Standards (JIS A 1101,
JIS A 1128, JIS A 1108, JIS A 1132), and the results are shown in Table 2. In addition, using the obtained concrete, JIS A
A freeze-thaw test of concrete was conducted according to the method described in Annex 2 of 6204, and the results are shown in Table 3. Examples 2 to 7 Copolymers shown in Table 1 and laurylamine EO 15 mol adducts shown in Table 1 were used instead of copolymer (1) and laurylamine EO 15 mol adducts in Example 1. Concrete was prepared in the same manner as in Example 1 except for the amount used. The slump, air content, and compressive strength of each of the obtained concretes were measured in the same manner as in Example 1, and the results are shown in Table 2. Comparative Example 1 Concrete was prepared by repeating the same operations as in Example 1 except that the 15 mol laurylamine EO adduct was not used. The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2. Comparative Example 2 Except that the amount of laurylamine EO 15 mol adduct used in Example 1 was 0.04% based on cement,
Concrete was prepared by repeating the same operation as in Example 1. The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2. Comparative Example 3 Instead of the laurylamine EO 15 mole adduct in Example 1, an adduct obtained by reacting so that the average number of moles of ethylene oxide added per molecule of laurylamine was 100 moles (hereinafter referred to as laurylamine) was used.
It is called EO 100 mole adduct. ), except that the same amount of
Concrete was prepared by repeating the same operation as in Example 1. The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2. Comparative Example 4 The antifoam agent FS Antiform 90 was used instead of the laurylamine EO 15 mole adduct in Example 1.
(manufactured by Dow Corning) was used in the same amount, but the same operation as in Example 1 was repeated to prepare concrete. The slump, air content, and compressive strength of the obtained concrete were measured in the same manner as in Example 1, and the results are shown in Table 2. Furthermore, using the obtained concrete, a concrete freeze-thaw test was conducted in the same manner as in Example 1, and the results are shown in Table 3.

【table】

[Table] From Tables 2 and 3, the method for adjusting the amount of entrained air in cement mortar or concrete of the present invention involves using a large amount of a water-soluble polycarboxylic acid polymer having air entrainment properties as a cement dispersant. It is clear that by setting the amount of air entrained in a suitable amount and making the entrained air bubbles of good quality, excellent properties can be imparted to cement mortar and concrete after hardening.

Claims (1)

[Claims] 1 General formula (A) (However, R ¹ represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, l and m are each independently a positive integer of 1 or more, and 5≦l+m≦50
It satisfies the following. ) A water-soluble polycarboxylic acid polymer containing as essential components an ethylene oxide derivative of a primary amine () and a structural unit represented by the following general formula (b) and a structural unit represented by the general formula (c).
The weight ratio of primary amine ethylene oxide derivative ()/water-soluble polycarboxylic acid polymer () =
A method for adjusting the amount of entrained air in cement mortar or concrete, characterized in that it is used at the time of mixing cement mortar or concrete at a ratio of 0.1/100 to 10/100. (Record) (However, X represents hydrogen, a methyl group or -CH ₂ COOZ, Y represents hydrogen, a methyl group or -COOZ, and Z represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or the general formula (a)) Represents an organic amine group excluding the ethylene oxide derivative () of the expressed primary amine.) [However, R ² represents hydrogen or a methyl group, A is hydrogen, an alkyl group having 1 to 23 carbon atoms, an aryl group, an alkylaryl group, a sulfonated aryl group, -OR ³ , -CH ₂ OR ³ , - COOR ³ , -COO-(
D-O-) _o R ⁴ or -CH ₂ -O-(D-O-) _o R ⁴ (R ³ is an alkyl group with 1 to 5 carbon atoms, D is an alkyl group with 2 carbon atoms
to 4, R ⁴ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and n is a positive integer of 1 to 100. ]