JPS59162158A - Cement dispersant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] FIELD OF THE INVENTION This invention relates to seven-layer l-dispersants.

For more details, please refer to Cement Morta IV or Cement Mortar IV, which is suitable for pouring concrete at construction sites and molding processing of secondary concrete products, greatly reduces the amount of cement mixing water without reducing work efficiency, and furthermore, after hardening. The present invention relates to a cement dispersant that has a large water-reducing effect and can improve the strength of cement mortars and concrete.

Conventionally, studies have been made to reduce the amount of mixing water used to improve strength, and cement dispersants have been used for this purpose. Various agents have been used as this agent, such as phosphonin sulfonate, oxycarboxylate, naphthalene sulfonate formalin condensate, and melamine sulfonate formalin condensate. However, these have limited dispersion ability. It has a limited ability to accelerate curing. It has drawbacks such as high air entrainment and a significant decrease in strength, so it is not fully satisfactory. ! Recently, there has been a demand for cement dispersants with high cement dispersion ability. - Co-1X combinations with unsaturated dicarboxylic acid salts are known. However, although these dispersants have slightly improved dispersibility compared to those based on naphthalene sulfonate formalin condensates, they still cannot be said to have sufficient cement dispersibility. In order to obtain the desired properties, it is necessary to use a large amount of these relatively expensive dispersants.
Furthermore, the chain olefin and α,β-unsaturated dicarboxylic acid copolymer has the drawback of significantly delaying cement hardening.

Under these circumstances, the present inventors conducted extensive research into a dispersant for cement that does not have any of the above drawbacks, and as a result, they arrived at the present invention. That is, the present invention has a structure in which the molar ratio of the structural unit represented by the following general formula (I) to the structural unit represented by the general formula (A) is 9.
Molecular weight within the range of /1 to 1/9 1000 to 5000
1. A dispersant for cement comprising a water-soluble polymer compound of 0.

(In the formula, R,, R2 is hydrogen or a methyl group, L is -CON
Alkylene group with H number of 2 to 3, t, m, n & j: 1 to zo
tD number, where m + t is a number from 2 to 20) (In the formula, R3 is hydrogen or methyl group 2M is hydrogen or -co
ox2 group, R4U hydrogen, methyl group, -CH,C
A group selected from 00X3 groups X, , X2. X3
each independently represents a water, a salt, or a -(BO)pR5 group, at least one of xl and x2X3 is hydrogen or a salt, B is an alkylene group having 2 to 3 carbon atoms, and p is 0
~2o number.

R5 is hydrogen or alkyl having 1 to 2 carbon atoms cycloalkyl having 4 to 7 carbon atoms The water-soluble polymer compound of the present invention has the formula (1) as shown in general formula (1), and a side chain as shown in general formula (a). It is a copolymer consisting of units having at least one carboxyl group or a salt thereof. Such polymer compounds are usually produced by copolymerizing monomers having -CONH(AO)nH groups or -CON carboxyl groups in their side chains at a predetermined ratio. Ill get it. In this case, CONH(AO)nH giving the structural unit of the general formula 〇) is an unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid/V acid, crotonic acid, H(AO)nH or HN amidide, Examples include amide compounds made by adding ethylene oxide or propylene oxide to unsaturated amides such as acrylic acid amide, methacrylic acid amide, crotonic acid amide, etc. under mild conditions (for example, 60 to 80'C). . Examples of monomers having at least one carboxyl group in the side chain that provide the structural unit of general formula (A) include:
acrylic acid.

Examples include unsaturated monocarboxylic acids such as methacrylic acid and crotonic acid, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid. In addition, these unsaturated dicarboxylic acids and the general formula RsO
” (BO) pH (R5 is hydrogen or carbon number 1~
2nd alkyl group or cyclo7z+zki* having 4 to 7 carbon atoms
group, B is an alkylene group having 2 to 3 carbon atoms.

P is a number from 0 to 20) Monoesterified products with alcohol alcohols are mentioned. At this time, if R5 is an alkyl group having 21 or more carbon atoms or if P exceeds 20, this is not preferable because air entrainment becomes high and the strength of the concrete decreases. The dispersant of the present invention can also be obtained by methods other than those described above. For example, the above one CONH
After copolymerizing with the above unsaturated dicarboxylic acids, R
Alcohol or glyco- indicated by 50-(BO)pH
It may also be obtained by adding a predetermined amount of /V 6'A k and converting the entire unsaturated dicarboxylic acid into a monoester. Alternatively, it may be obtained by copolymerizing unsaturated monocarboxylic acids such as acrylamide, methacrylamide, crotonamide, etc. and unsaturated dicarboxylic acids such as maleic acid, and then adding ethylene oxide or propylene oxide. good. Furthermore, it can also be obtained by partially amidating a homopolymer such as acrylic acid or methacrylic acid with ammonia, and then adding alkylene oxide. In order to make the polymer thus obtained water-soluble, some or all of its carboxy p groups are usually used in the form of a salt. The ionic moieties that form these salts are alkali metal ions such as lithium, sodium, and potassium.

Alkaline earth metal ions such as calcium and magnesium, trivalent metal ions such as aluminum, iron, etc., ammonium, ethanolamine, dimethyl amine
, trie chiruamin , to
Ions from organic amines such as ethanolamine can be collected.

Among the dispersants of the present invention, those having the cement dispersing ability are more preferable when n, m, and L in the general formula (I) are numbers of 1 to 5, provided that m+t is a number of 5 or less. Also, the general formula α
), preferred from the viewpoint of cement dispersion ability are those in which R3, R, is hydrogen or a methyl group, and M is hydrogen, and is based on ataxic acid, methacrylic acid, or crotonic acid. When unsaturated dicarboxylic acids and monoesters of these with alcohols and glycols are used as component (1) of the present invention, the dispersibility of cement is slightly inferior. In the dispersant of the present invention, the molar ratio of the structural units represented by the general formula (the structural unit represented by W and the general formula Nail) is 9/I to 1.
It is necessary to be within the range of /9. This ratio is 9/1
If it exceeds 1/9, it not only reduces the dispersion ability of cement but also slows down the hardening of concrete, which is undesirable. More preferably, this ratio is within the range of 7/3 to 3/7 because it has excellent dispersion ability and does not delay the hardening of cement at all.

In addition to the unit of formula α)j(a), other unsaturated monomers may also be copolymerized to the extent that the performance is not impaired. These and others. Examples of unsaturated monomers include esters such as acrylic esters and methacrylic esters (usually the number of carbon atoms in the ester moiety is 20 or less).
Diesters such as maleic acid and fumaric acid) V [HO-
CBO) I) Diester with Rs], vinyl esters such as vinyl acetate and vinyl propionate, vinyl aromatics such as styrene, sulfonic acids such as styrene sulfonic acid and vinyl sulfonic acid, olefins such as butene, isobutyne, and octene. Various examples can be mentioned, such as:

Copolymerization of acid esters, methacrylic acid esters, styrene sulfonic acids, etc. in which the number of carbon atoms in the ester group is 5 or less may actually improve the cement dispersion ability and give favorable results. The amount of the monomer added varies depending on the type of amide group, carboxy/l' group and their equivalent ratio in the water-soluble polymer compound of the present invention, but is usually 30% by weight or less. A water-soluble polymer compound can be obtained according to a method commonly used in industry.For example, radical polymerization is generally used as a reaction type, but solution polymerization is preferable in this case. Lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, hydrocarbons such as benzene, and acetone.

Ketones such as methyl ethyl ketone are used as solvents. Examples of polymerization initiators include peroxides such as benzoyl peroxide and tert-butyl peroxide, azo compounds such as azobisisobutyronitrile, and persulfates, solvent types, and monomers. It can be selected as appropriate depending on the type of polymer, and since the activation energy for decomposition is small, polymerization can be initiated under mild conditions. The copolymer obtained in this way is the best acid! ,''!, can also be used as a dispersant in the present invention, but it can be neutralized with an alkaline substance, and some or all of the carboxylV& is mixed with an alkali metal salt, an alkaline earth metal salt, or a salt of ammonium or an organic amine.
It can be used as The molecular weight can be adjusted by changing the concentration of hexamer in the solvent, the reaction temperature, and the reaction time, but those with a molecular weight in the range of 1000 to 50000 have particularly good water solubility and good dispersibility in cement. It is something that is in . If the molecular weight is less than 1,000, it not only delays the hardening of the cement, but also reduces the dispersion ability of the cement.
If the molecular weight exceeds 50,000 t-, the dispersion ability of the cement will be significantly reduced.More preferably, the molecular weight is 3,000 to 3.
It is within the range of 0000. Although the dispersant of the present invention can be used as a solid or powder, it is usually used as an aqueous solution or an aqueous dispersion. It can also be used as an organic solvent solution.

The cement dispersant of the present invention can be used in combination with other components as required. Such a component is a sulfate ester salt of an alkylbenzene sulfone fatty acid alkylene oxide adduct.

Known air-entraining agents such as Vinzol, lignin sulfonate, polyyalene glycol, styrene sulfone [i-combination, styrene sulfonic acid copolymer with monoethylenic monomer, oxycarboxylic acid salt, polyethylene sulfonic acid] Copolymer of salt, α, β-unsaturated dicarboxylic acid and chain olefin.

Known dispersants such as sulfonic acid salts of heavy aromatic hydrocarbons or formalin condensates of these, 1, pure, 1 min. Known cement dispersants such as condensates, calcium chloride.

Sodium chloride, sodium sulfate, soda carbonate.

Known cement hardening accelerators such as potassium carbonate, sodium thiosulfate, alkanolamine, lignin sulfonic acid,
Known cement hardening retardants such as gluconic acid, citric acid, tartaric acid and polyphosphoric acid; known cement retardants such as polyvinylic acid/recole, soap powder, methyl cellulose and hydroxymethyl cellulose; nitrous acid and liu. A variety of known antirust agents such as aluminum, calcium nitrite, and the like can be used.

Examples of cements to which the cement dispersant of the present invention can be used include Fuichisan Portland cement, early-strength Bolletland cement, and medium-heat Portland cement.

Examples include alumina cement, fly ash cement, and blast furnace cement. Among these, preferred is Portland cement.

The amount of the cement dispersant of the present invention added can be varied depending on the use of the cement and the required performance, but usually the dispersant of the present invention is added to the cement in a pure amount of 0.01 to 5%, preferably. is α05-1% by weight. It is usually 005 to 03% by weight for ready-mixed concrete products, and α1 to 1% by weight for two-shot concrete products.

The dispersant is typically used in cement and aggregates (such as sand and crushed stone).
It is added when mixing and adding kneading water, but after mixing cement, aggregate, and water, and after cement is hydrated by contact (from 1 to 10 minutes after mixing)
It may be added after 2 minutes or more, or it may be added to cement in advance and then water is added. Furthermore, it is also possible to use a split addition method in which a part of the present dispersant is added at the time of cross-crossing, and then the remaining dispersant is added in one or more portions. The method may be the same as in the case of 9, and various methods such as troweling, spraying, filling into a mold, and injection using a caulking gun can be used. The curing method may be air dry curing, humid air curing, water curing, heating accelerated curing (steam curing, autoclave curing, etc.), or a combination of each may be used.

The cement dispersant of the present invention has an extremely excellent cement dispersing ability and is characterized in that hardening of cement is not delayed. Taking advantage of this characteristic, this dispersant is used for roofs, walls, floor mortar, building frames, and molded parts of buildings, etc. Credit Mix Concrete is characterized by its excellent dispersibility. It is suitable as a dispersant for concrete and as a molding agent for producing secondary concrete products.

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Note that all parts in the examples indicate parts by weight based on pure components.

50 mol% of monomers having various carboxy p groups shown in 1.
The dispersant of the present invention was obtained using a sodium salt of a water-soluble polymer compound having a molecular weight of about 8,000 obtained by copolymerizing the following. Using these, the following concrete mixture was prepared, and the fluidity (indicated by slump), setting time, and strength of the concrete were measured, and the results shown in Table 1 were obtained. In Table 1, for comparison with the dispersant of the present invention, naphthalene sulfonate formalin condensate (abbreviated as NSF), lignin-based water reducing agent (including poly-resium), When glumono-shun soda is used as an oxycarboxylic acid-based water reducing agent, maleic anhydride-imbutene (50:
50 m/m ratio) copolymer soda salt, allyl alcohol-7
When a soda salt of a copolymer of 50 mol% of an alkylene oxide adduct of or allyl alcohol-7 and 50 mol% of a monoester of maleic acid or hamaric acid is used, and no dispersant is used at all. The results in the case where there was no test are also described. Incidentally, when a dispersant was used, the concrete formulation was such that the unit cement amount was 32'oky/m', the water/cement ratio was 55%, and the fine aggregate percentage was 46%. The concrete mix when no dispersant is used is a unit cement amount of 320
R/'7" n water/cement ratio 60%, m aggregate ratio 46%
It is. Also, the concrete temperature is 20℃, and the compressive strength is 2
This is the value when curing in water at 0°C. In addition, in Table 1, A
LA stands for allyl alcohol, ALA EOs.

ALA E()+o td each, allyl dubbing-I
Theal is a product obtained by adding 5 moles or 10 moles of ethylene oxide to 1 mole of ethylene oxide. Also, MAL/inic acid E01. . ,
E'03. o, EOs, o, PO3,.

Each of these is a monoester of maleic acid obtained by adding ethylene glycol/I/triethylene glycol/I/, pentaethylene glycol, and tripropylene glycol in a ratio of 1 mole each to 1 mole of maleic anhydride.

As is clear from Table 1, the dispersant of the present invention provides excellent concrete fluidity even when added in a very small amount compared to conventional dispersants, and it does not retard the hardening of cement at all. I understand.

Example 2 50 mol% acrylic acid and various -CONH-(AO)n
A dispersant of the present invention was obtained using a sodium salt of a water-soluble polymer compound having a molecular weight of about 8,000 obtained by polymerizing Hm.

Using these, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 2 were obtained. Incidentally, the acrylamide EO1-og hour%c in Table-2. 4cm2cm □
Acrylamide Eo+a, o is CH”+!”C0N
H(CH2CH20)3H'CH""'4NHCH2C
H20H' Eo of crotonamide, 0 is CH, CH=C
,:CONri(cH,ci+,o) ,H,,,,,
Show.

(CH2CH20) 2H Example 3 Various types of concrete were prepared in the same manner as in Example 1 using a sodium salt of a water-soluble polymer compound obtained by changing the copolymer composition of acrylic acid and HEMAmO copolymer. A test was conducted and the results shown in Table 3 were obtained.

Example 4 Using sodium salts of copolymers of 50 mol% acrylic acid and 50 mol% HEMAm with different molecular weights, various concrete tests were conducted in the same manner as in Example 1, and the results shown in Table 4 were obtained. .

339

Claims (1)

[Claims] 1. A molecule ffLiooo~ in which the molar ratio of the structural unit represented by the following general formula (I) to the structural unit represented by the general formula (A) is within the range of 9/1 to 1/9. A cement dispersant characterized by comprising a water-soluble polymer compound of 50,000. (In the formula, R, R2 are hydrogen or methyl groups, L is -CONH
Alkylene group of numbers 2 to 3, t, m, n are numbers of 1 to 20, where m + 1 is a number of 2 to 20) (In the formula, R3 is hydrogen or methyl group 1M is hydrogen or -co
ox2 group, R4ha hydrogen, methyl group, -CH2C
A group selected from ooXs group, Xl, X2. X3
are each independently hydrogen, salt, or (K (180),
The R5 group is represented by Xl. X2. Xρ At least one is hydrogen or a salt, B is an alkylene group having 2 to 3 carbon atoms, P is a number of O to 20, R5 is hydrogen or an alkyl group having 1 to 20 carbon atoms, or an alkyl group having 4 to 7 carbon atoms
The dispersion according to item 1, wherein the ratio of the structural unit represented by the cycloalkyl 2 general formula (I) to the structural unit represented by the general formula (A) is within the range of 7/3 to 3/7. agent. a) R3 and R4 of the general formula Φ) are hydrogen or methyl groups, and M
2. The dispersing agent according to claim 1, wherein is hydrogen. 4. In general formula α), t, m, and n are numbers from 1 to 5, provided that m+
3. The dispersant according to any one of items 1 to 3, wherein t is a number of 5 or less. 5. The molecular weight of the water-soluble polymer compound is 3000 to 3000
4. The dispersant according to any one of items 1 to 4, wherein the dispersant is 0.