JPH07215746A - Additive for cement - Google Patents

Abstract

PURPOSE:To obtain an additive having a high effect to prevent slump loss and high water reducing property with which the amt. of air can be controlled when the additive is added and kneaded with cement by compounding a polyoxyalkylene deriv. into a copolymer of a specified polyoxyalkylene deriv. CONSTITUTION:This additive for cement contains an effective component obtd. by compounding 0.01-5 pts.wt. of polyoxyalkylene deriv. (B) expressed by formula II into 100 pts.wt. of copolymer (A) or its free acid type or basic copolymer of polyoxyalkylene deriv.(i) expressed by formula I and maleic acid anhydride (ii). In formula, Z is a residue of a compd. having 2 to 8 OH groups from which OH is removed, A<1>O, A<2>O, A<3>O are oxyalkylene groups having 2-18 carbon number, X is an unsatd. hydrocarbon group having 2-5 carbon number, R is a hydrocarbon group having 1-40 carbon number, (a), (b), (c) are integers 1 to 150, (m) is 1 or 2, (p) is 1 to 7, m+n+p=2 to 8, n/(m+p)<=1/2, and am+dn+ cp>=1, Y is a hydrocarbon having 2-22 carbon number, R<1>O, R<2>O are oxypropylene groups, (d), (f) are 0, 1 to 50, (e) is 1 to 20, and both of (d) and (f) are not 0.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel cement additive, more specifically for cement, which has a high water-reducing property and a high slump loss preventing property, and in which the amount of air entrained during the mixing of the cement can be easily adjusted. It relates to additives.

[0002]

2. Description of the Related Art Polycarboxylic acid-based, naphthalene sulfonic acid-based, melamine sulfonic acid-based, lignin sulfonic acid-based water-reducing agents have been used as additives for cement formulations such as concrete and mortar. In recent years, the demand for high strength has increased in concrete, and it has become necessary to reduce the amount of water in concrete compositions. Although the above-mentioned additive has an effect of reducing the amount of water in the concrete composition, it has a drawback in that the fluidity of the concrete composition which is deteriorated with time, that is, so-called slump loss cannot be avoided. Therefore, in order to improve this defect, a copolymer having an excellent slump loss preventing effect and a large water-reducing property (Japanese Patent Laid-Open No. 63-285140) has been disclosed. There was a problem with too much quantity. Generally, polycarboxylic acid type water reducing agents have a problem that the amount of air entrained by the entrained air increases too much when an amount that gives a certain fluidity (shown by slump value in concrete etc.) is added to the cement mixture. . If the amount of air is too large, it will reduce the compressive strength of concrete. In addition, there is a problem that the appearance quality of the molded product deteriorates due to the inclusion of air bubbles. Therefore,
In order to solve this problem, a terminal esterified product of a polyoxyalkylene block copolymer has been proposed (Japanese Patent Laid-Open No. 61-111950). However, in this product, a high slump loss preventive property and an amount of air entrained are taken. It was difficult to make both adjustments at the same time.

[0003]

Under the circumstances described above, the present invention is a cement which has a high water reducing property and a high slump loss preventing property, and in which the amount of air entrained during the mixing of the cement can be easily adjusted. The purpose is to provide an additive for use.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies to develop a cement additive having the above-mentioned preferable properties, the present inventors have found that a specific copolymer having a specific copolymer and a specific polymer having a defoaming effect is obtained. An oxyalkylene derivative and a mixture of the oxyalkylene derivative at a predetermined ratio exhibit an excellent slump loss prevention effect when used for cement, and have a large water reduction property, and the amount of air to be carried can be adjusted, It was found that a molded product having high strength can be provided, and the present invention has been completed based on this finding. That is, the present invention provides (A) (a) general formula [1]

[Chemical 2] (Z in the formula is a residue of the compound having 2 to 8 hydroxyl groups excluding the hydroxyl groups, A ¹ O, A ² O and A ³ O are each an oxyalkylene group having 2 to 18 carbon atoms, and they are They may be the same or different, X is an unsaturated hydrocarbon group or unsaturated acyl group having 2 to 5 carbon atoms, and R is 1 to 1 carbon atoms.
40 hydrocarbon groups, a, b and c are each 0 or 1
An integer of 150, m is 1 or 2, p is an integer of 1 to 7, and satisfy the relations of m + n + p = 2 to 8, n / (m + p) ≦ 1/2 and am + bn + cp ≧ 1. ), A copolymer of a polyoxyalkylene derivative represented by (4) and (b) maleic anhydride, and 100 parts by weight of a free acid type or salt type copolymer thereof, (B) is represented by the general formula [2] YO (R ¹ _{O) d (C 2 H 4} O) e (R 2 O) f H ... [2] (Y is a hydrocarbon group having 8 to 22 carbon atoms in the formula, R ¹ O and R ² O are each oxypropylene group Or an oxybutylene group, which may be the same or different from each other, and d and f are 0 or an integer of 1 to 50, e is an integer of 1 to 20, and both d and f are 0. 0.0) Polyoxyalkylene derivative represented by 0.0
The present invention provides an additive for cement, which contains 1 to 5 parts by weight as an active ingredient.

The present invention will be described in detail below. The polyoxyalkylene derivative of the component (a) used as the raw material of the component (A) in the additive for cement of the present invention has the general formula [1]

[Chemical 3] It has a structure of. In the above general formula [1], Z is a residue excluding the hydroxyl group of the compound having 2 to 8 hydroxyl groups. Examples of the compound having 2 to 8 hydroxyl groups include polyhydric phenols such as catechol, resorcin, hydroquinone and phloroglucin; ethylene glycol, propylene glycol, butylene glycol, dodecylene glycol, octadecylene glycol, neopentyl glycol, Styrene glycol, glycerin, diglycerin, polyglycerin, trimethylolethane, trimethylolpropane, 1,3,5-pentanetriol, erythritol, pentaerythritol, dipentaerythritol, sorbitol, sorbitan, sorbide, sorbitol-glycerin condensate, adonitol , Arabitol, xylitol, mannitol and other polyhydric alcohols; xylose, arabinose,
Ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose,
Examples thereof include sugars such as maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, and melezitose; and partial etherified products and partially esterified products thereof.

A ¹ O, A ² O and A ³ O are each an oxyalkylene group having 2 to 18 carbon atoms, such as oxyethylene group, oxypropylene group, oxybutylene group, oxytetramethylene group and oxystyrene. Examples thereof include a group, an oxidedecylene group, an oxytetradecylene group, an oxyhexadecylene group, an oxyoctadecylene group, and the like, and an oxyalkylene group having 2 to 4 carbon atoms is particularly preferable because of good copolymerization reactivity. The A ¹ O, A ² O and A ³ O
They may be the same or different. X is an unsaturated hydrocarbon group having 2 to 5 carbon atoms or an unsaturated acyl group, for example, vinyl group, allyl group, methallyl group, 4-pentenyl group, 3-methyl-3-butenyl group,
Examples thereof include an acrylic group and a methacrylic group. The carbon number of X is related to the polymerizability, and when the carbon number is more than 5, the polymerizability becomes poor, so the carbon number of 2 to 5 is suitable.
Further, R is a hydrocarbon group having 1 to 40 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group,
Butyl group, isobutyl group, tert-butyl group, amyl group, isoamyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, isotridecyl group, tetradecyl group,
Hexadecyl group, isohexadecyl group, octadecyl group, isooctadecyl group, oleyl group, octyldodecyl group, docosyl group, decyltetradecyl group, benzyl group, cresyl group, butylphenyl group, dibutylphenyl group, octylphenyl group, nonylphenyl Group, dodecylphenyl group, dioctylphenyl group, dinonylphenyl group, naphthyl group, styrenated phenyl group and the like.

In the above general formula [1], a, b and c
Are 0 or an integer of 1 to 150, respectively, and when it is larger than 150, the viscosity becomes high and the production becomes difficult. m is 1 or 2, and when m is 1, a linear copolymer is formed, and when it is larger than 2, a crosslinked copolymer is formed and a gel is easily generated. Moreover, p is an integer of 1 to 7, and n is m + n + p.
= 2 to 8 and n / (m + p) ≤ 1/2, which is an integer satisfying the relationship of 0, 1 or 2. When n is larger than 2, an ester with an acid is likely to be formed during the polymerization reaction, and some of the formed ester have a structure in which the copolymers are cross-linked with each other, resulting in the formation of gel. It becomes easier. Further, am + bn + cp must be 1 or more, and 1 to 300 is particularly preferable. When am + bn + cp exceeds 300, the viscosity becomes high and the production becomes difficult. A ¹ O, A ² O
And the combination of the number of carbon atoms of the oxyalkylene group represented by A ³ O, the total number of added moles, and the hydrocarbon group represented by R make the polyoxyalkylene derivative represented by the general formula [1] hydrophilic. It can also be hydrophobic. Although both hydrophilicity and hydrophobicity are effective as the additive, when attention is paid to the slump loss preventing effect, a copolymer which is soluble in water to some extent is more effective. Therefore, A ¹ O, A ²
When O and A ³ O are oxyethylene groups alone, or when they are a mixture with other oxyalkylene groups and the oxyethylene groups are 25 mol% or more, they are hydrophilic and suitable. In the present invention, as the component (A), a copolymer of the polyoxyalkylene derivative as the component (a) and maleic anhydride as the component (b), or a free acid type or salt type copolymer thereof is used. Here, the free acid type copolymer means that the maleic anhydride unit in the copolymer is replaced with a free maleic acid unit, and the salt type copolymer means that the maleic acid unit is a salt. Is formed. Therefore, the free acid type copolymer may be produced by copolymerizing the polyoxyalkylene derivative of the component (a) and maleic anhydride and then hydrolyzing it. It may be produced by copolymerizing with maleic acid. Also,
The salt-type copolymer may be produced by converting the free acid-type copolymer obtained as described above into a salt, or by producing the polyoxyalkylene derivative and a maleate salt. You may.

Examples of the salt of the salt type copolymer include alkali metal salts such as lithium salt, sodium salt and potassium salt; alkaline earth metal salts such as magnesium salt and calcium salt; ammonium salt and further organic amine salt. There is. As the organic amine salt, methylamine salt, ethylamine salt, propylamine salt, hexylamine salt, octylamine salt, 2-ethylhexylamine salt, decylamine salt, dodecylamine salt, isotridecylamine salt, tetradecylamine salt, hexa Aliphatic amines such as decylamine salt, isohexadecylamine salt, octadecylamine salt, isooctadecylamine salt, octyldodecylamine salt, docosylamine salt, decyltetradecylamine salt, dimethylamine salt, trimethylamine salt; ethylenediamine salt, tetramethylene Diamine salt, dodecyl-
Aliphatic polyamine salts such as propylenediamine salt, tetradecyl-propyleneamine salt, diethylenetriamine salt, triethylenetetramine salt, tetraethylenepentamine salt, pentaethylenehexamine salt; monoethanolamine salt, diethanolamine salt, triethanolamine salt, monoisopropanol Alkanolamine salts such as amine salts, diisopropanolamine salts and triisopropanolamine salts, and salts of these alkylene oxide adducts; alicyclic hydrocarbon amine salts such as cyclohexylamine salts, aromatic monoamine salts such as aniline salts, etc. Is mentioned. Among these, especially alkali metal salts,
Ammonium salts and alkanolamine salts are preferred.
The copolymer of the component (A) is obtained, for example, by using (a) a polyoxyalkylene derivative represented by the general formula [1] and (b) maleic anhydride or maleic acid or a maleic acid salt as a peroxide-based initiator or azo. It can be easily obtained by copolymerizing with a system initiator. At that time, styrene, α
-Other copolymerizable components such as olefin and vinyl acetate may be mixed and copolymerized. Further, (a) a polyoxyalkylene derivative represented by the general formula [1] and (b)
The molar ratio of maleic anhydride or maleic acid or maleic acid salt is usually 1: 0.5 to 1: 2.0, more preferably 1: 0.9 to 1: 1.2. is there.

In the cement additive of the present invention,
As the component (B), a polyoxyalkylene derivative represented by the general formula [2] YO (R ¹ O) _d (C ₂ H ₄ O) _e (R ² O) _f H ... [2] is used.
In the above general formula [2], Y is a hydrocarbon group having 8 to 22 carbon atoms, for example, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group,
Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, isooctadecyl group, nonadecyl group, eicosyl group, oleyl group, octyldodecyl group, behenyl group, benzyl group, cresyl group, Examples thereof include saturated hydrocarbon groups such as butylphenyl group, dibutylphenyl group, octylphenyl group, nonylphenyl group and dodecylphenyl group, unsaturated hydrocarbon groups, aromatic groups and substituted aromatic groups. If the number of hydrocarbons in this hydrocarbon group is less than 8, the interfacial adsorption force becomes weak and a sufficient defoaming effect cannot be obtained, and if it exceeds 22, the hydrophobicity becomes too large and the defoaming property becomes poor.
Particularly preferred hydrocarbon groups are saturated or unsaturated ones having 12 to 18 carbon atoms. R ¹ O and R ² O are an oxypropylene group or an oxybutylene group, and they may be the same or different. further,
d and f are 0 or an integer of 1 to 50, and e is 1 to 2
It is an integer of 0, and d and f are never 0. If this condition is not satisfied, the balance between hydrophobicity and hydrophilicity will be poor and the defoaming property will be poor. For example, when d and f exceed 50, the hydrophobicity becomes too large, and when e exceeds 20, the hydrophilicity becomes too large, and in any case, the defoaming property decreases.

The method for producing the polyoxyalkylene derivative as the component (B) is not particularly limited. For example, butylene oxide or propylene oxide is added to a hydroxyl group-containing compound, ethylene oxide is added, and then butylene oxide or propylene is added. It can be produced by adding an oxide in a block form. In the additive for cement of the present invention, it is necessary to blend the polyoxyalkylene derivative of the component (B) in a proportion of 0.01 to 5 parts by weight with respect to 100 parts by weight of the copolymer of the component (A). Is. If this amount is less than 0.01 parts by weight, the defoaming effect will not be sufficiently exhibited, and if it exceeds 5 parts by weight, the remarkable defoaming effect will not be observed. The additive for cement of the present invention is usually added in an amount of 0.01 to 3% by weight, preferably 0.04 to 1% by weight, based on cement. If the amount added is less than 0.01% by weight, the slump loss preventing property and the water reducing property, which are the effects of the present invention, are not improved, and the amount of entrained air cannot be adjusted.
When the content is more than 10% by weight, the effects of the present invention are exhibited, but workability such as retardation of setting is deteriorated, which is not preferable. Additives for cement of the present invention, as long as the performance is not impaired, other additives such as naphthalene sulfonic acid formalin condensate salt, melamine sulfonic acid formaldehyde condensate salt, polycarboxylic acid compounds such as sodium polyacrylate. Alternatively, a rust preventive agent, a setting accelerator, a setting retarder and the like may be used in combination.

[0011]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Examples 1 to 16 Copolymers of component (A) shown in Table 1 and polyoxyalkylene derivatives of component (B) shown in Table 2 were mixed in the proportions shown in Table 3 and added for cement. The agent was prepared. Tests with concrete were carried out using this additive.
The composition and test conditions are shown below. Mixture composition Water 166kg / m ³ Cement 450kg / m ³ Sand 681kg / m ³ Crushed stone 1032kg / m ³ Additive Type and amount shown in Table 4 Water / cement ratio 36.9% Fine aggregate ratio 39.9% Above Each component was placed in a forced kneading mixer, kneaded and mixed for 2 minutes, then taken out, and the slump and the air amount were measured. Then, the mixture was further transferred to a tilting mixer and mixed at 2 revolutions per minute, and after 30 minutes, 60 minutes, and 90 minutes, the slump value and the air amount were measured. The setting time and compressive strength were also measured, and the results are shown in Table 4.

[0012]

[Table 1]

[Note] 1) Inside {} indicates a random adduct. 2) C ₄ H ₈ O represents an oxybutylene group. 3) Maleic acid derivative MAn: Maleic anhydride MA: Maleic acid MANa: Sodium maleate MAA: Ammonium maleate

[0014]

[Table 2]

[0015]

[Table 3]

Comparative Examples 1 to 5 Using the compounds shown below as comparative examples, the same tests as in Examples 1 to 16 were conducted. The results are shown in Table 4. Comparative Example 1 Copolymer B shown in Table 1 Comparative Example 2 Copolymer C shown in Table 1 Comparative Example 3 Copolymer D shown in Table 1 Comparative Example 4 Copolymer C shown in Table 1 2 6% by weight of S shown in Table 2 Comparative Example 5 Polyacrylic acid-based compound with defoaming agent added

[0017]

[Table 4]

[0018]

[Table 5]

From the above results, Examples 2 to 8 and Comparative Example 1
From the comparison of ~ 3, the additive of the present invention has a smaller air content and a higher compressive strength. Therefore, the product of the present invention can be optimally adjusted with a small amount of air, and is an excellent additive capable of maintaining the high slump loss preventing effect and high water reducing property of the conventional polycarboxylic copolymer. I understand. Further, when comparing Comparative Example 4 in which the amount of the polyoxyalkylene derivative having a defoaming effect is added in an amount of more than 5% by weight with respect to the copolymer, and Example 5 of the present invention, the values are similar for all test items. However, it can be seen that a remarkable defoaming effect is not obtained. Further, it can be seen that the product of the present invention can maintain slump loss prevention longer than that of the polyacrylic acid-based copolymer used in Comparative Example 5.

[0020]

The cement additive of the present invention is a copolymer of a specific polyoxyalkylene derivative and maleic anhydride, a free acid type or salt type copolymer thereof and a polyoxyalkylene having a specific defoaming effect. A derivative is mixed as an active ingredient, and when added to cement and kneaded, the amount of air can be easily adjusted, and a high slump loss preventing effect and a high water reducing property are obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 71/02 LQE // C04B 103: 30

Claims (2)

[Claims] 1. (A) (a) General formula [1] (Z in the formula is a residue of the compound having 2 to 8 hydroxyl groups excluding the hydroxyl groups, A ¹ O, A ² O and A ³ O are each an oxyalkylene group having 2 to 18 carbon atoms, and they are They may be the same or different, X is an unsaturated hydrocarbon group or unsaturated acyl group having 2 to 5 carbon atoms, and R is 1 to 1 carbon atoms.
40 hydrocarbon groups, a, b and c are each 0 or 1
An integer of 150, m is 1 or 2, p is an integer of 1 to 7, and satisfy the relations of m + n + p = 2 to 8, n / (m + p) ≦ 1/2 and am + bn + cp ≧ 1. ), A copolymer of a polyoxyalkylene derivative represented by (4) and (b) maleic anhydride, and 100 parts by weight of a free acid type or salt type copolymer thereof, (B) is represented by the general formula [2] YO (R ¹ _{O) d (C 2 H 4} O) e (R 2 O) f H ... [2] (Y is a hydrocarbon group having 8 to 22 carbon atoms in the formula, R ¹ O and R ² O are each oxypropylene group Or an oxybutylene group, which may be the same or different from each other, and d and f are 0 or an integer of 1 to 50, e is an integer of 1 to 20, and both d and f are 0. 0.0) Polyoxyalkylene derivative represented by 0.0
A cement additive containing 1 to 5 parts by weight as an active ingredient. 2. The cement additive according to claim 1, wherein in the general formula [2] of the component (B), Y is a saturated or unsaturated hydrocarbon group having 12 to 18 carbon atoms.