JPS60171256A - Admixing agent for cement - 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 The present invention relates to a novel admixture for hydraulic cement that has excellent performance as a dispersant, water reducer, fluidizer, etc.
-ru. More specifically, the active ingredient is an addition copolymer of an N-substituted-α,β-unsaturated monocarboxylic acid substituted with a sulfonic acid group-containing residue and an α,β-unsaturated monocarboxylic acid or a salt thereof. Concerning standard hydraulic cement admixtures: Generally, concrete using cement,
When manufacturing mortar, paste, etc., admixtures called dispersants, reducers, or fluidizers are used. This admixture is expected to have the following effects. That is, (1) increasing the workability of unset cement mixtures; Also, if the workability is the same, the amount of water used can be reduced. (2) Since the amount of water used can be reduced, the strength after construction is increased as a result. Also, if the strength is the same, the amount of cement used can be reduced. (3) Totally increase watertightness. etc.

Conventionally, such admixtures include, for example, those mainly composed of lignin sulfonate, and those mainly composed of salts of gluconic acid, glucoheptonic acid, and the like.

β-naphthalene sulfonate formalin lt'6 combination Q
Known examples include those based on m, those based on a formalin high condensate of melamine having a sulfonic acid residue, and those based on polysaccharide. but,
Each of these has advantages and disadvantages, and no admixture has shown good performance in terms of dispersion fluidity, slump retention, and hardening properties of cement.

The inventors of the present invention have made extensive studies to overcome these drawbacks, and have found that by adding a hydraulic cement admixture containing a specific copolymer or its salt as a main component to a cement mixture, A cement compound with good dispersion fluidity and good workability with significantly suppressed slump reduction can be obtained, and the amount of air entrainment can be kept low regardless of changes in the amount of additives, resulting in a hardened product with commercial strength. The present invention was completed based on the discovery that the present invention is possible.

Thus, according to the present invention, an addition copolymer of N-substituted -α,β-unsaturated monocarboxylic acid substituted with a sulfonic acid group-containing residue and (blα,β-unsaturated molarcarboxylic acid) or its A hydraulic cement admixture containing salt as an active ingredient is provided.

The above-mentioned copolymers used in the present invention are conventionally known substances. For example, U.S. Patent No. 5,806.56
No. 7, No. 6.89 B, No. O'37.

It is described that such a copolymer, together with a homopolymer of 2-acrylamide-2-methylpropanesulfonic acid (hereinafter referred to as AMP8), is effective as a dispersant for iron, calcium, manganese, aluminum, etc.

However, in the present invention, it is an essential requirement that the copolymer is composed of the above-mentioned components (, 1 and (b)). It is inferior in fractional fluidity, water reduction property, slump retention, etc., and cannot achieve the purpose of the invention.

In addition, the compositions of the (al component and (1,) component are appropriately selected depending on the required performance, but usually (all component 5 ta 95 (b)
) Jy. 95 to 5 mol %, preferably 10 to 90 mol % of the component. The amount of component (b) is 90 to 10 mol %, more preferably 20 to 60 mol % per component, and 80 to 40 mol % of component (b).

Specific examples of component (b) used in the present invention include:

For example, acrylic acid, methacrylic acid, crotonic acid, etc. are mentioned, and acrylic acid and methacrylic acid U are praised for their ease of acquisition and ease of reaction.On the other hand, as specific examples of components (,) is an amide of an α,β-unsaturated monocarboxylic acid as described above and a sulfonic acid containing primary and secondary amino groups. Here, the sulfonic acid containing primary and secondary amino groups is a sulfonic acid group. In addition to the narrowly defined sulfonic acid having (-80,H), the sulfonic acid ester residue (-〇SO.
This also includes sulfonic acid esters having R). Specific examples include aminomethanesulfonic acid, aminoethanesulfonic acid, amino-2-methylpropanesulfonic acid, aminobutanesulfonic acid,
Monosulfonic acid, aniline disulfonic acid, aminotolu,
Ensulfonic acid, naphthylamine monosulfonic acid, naphthylamine disulfonic acid, naphthylamine trisulfonic acid% N-methylaminomethanesulfonic acid. N-ethylaminoethanesulfone M. N-methylaniline monosulfonic acid, N-methylnaphthylamine disulfonic acid, amidosulfuric acid, monoaminoethyl sulfate, mono-7<nopropyl sulfate, monoaminobutyl sulfate, monoaminohexyl m acid,
Sulfonic acid groups such as monoaminooctyl sulfate etc.
- Primary and 2R amino group-containing sulfonic acids containing 1 to 3 carbon atoms are exemplified, and among them, aliphatic or aromatic primary and secondary amino group-containing sulfonic acids having 1 to 10 carbon atoms are exemplified. .

The (,), (b11 component constituting the copolymer does not necessarily have to be a single component, and two or more components may coexist as appropriate, within a range that does not essentially impair the effects of the present invention. If necessary, other copolymerizable components may be included, such as acrylamide, methacrylamide, acrylic ester, methacrylic ester, maleic ester, acrylonitrile, and vinegar.
R Hinil.

Examples include styrene etc. The addition copolymer used in the present invention is not particularly limited as long as it functions as a cement admixture, but usually has a number average molecular weight of 500 to 500.
, preferably 1,000 to ao,oo
It is o.

If the molecular weight is larger than this, the dispersion performance will deteriorate, and if the molecular weight is too small, the dispersion performance will be insufficient.

The carboxyl groups and/or sulfonic acid groups present in the copolymer may be in the acid form, but if necessary, some of them may be converted into salts with monovalent or polyvalent cations to enhance water bathing ability. As a specific example of such a salt,
Examples include salts of alkali metals or alkaline earth metals such as sodium, magnesium, calcium, and barium, ammonium salts, and amine salts such as trimethylamine, triethylamine, triethanolamine, etc. Among them, the most economical ,safety,
Alkali metal salts are also praised for their dispersibility.

In addition, within the range that does not essentially impair the effects of the present invention,
It is also possible to use a part of the carboxyl group by esterification and L7'c lyamidation. The copolymer or its salt used in the present invention may be produced by any method as long as it has the above properties. . As a specific example of its manufacturing method, for example, ■AM
A method of radical polymerization of a sulfonic acid group-containing N-substituted-α,β-unsaturated monocarboxylic acid such as P8 with an α,β-unsaturated monocarboxylic acid (for example, as described in US Pat.
806.567 etc.), ■α such as acrylamide
, a method in which a copolymer of β-unsaturated monocarboxylic acid amide and α,β-unsaturated monocarboxylic acid is reacted with formaldehyde and a salt to sulpomethylate the amine group (for example, US Pat. , No. 761, 834)
, (2) A method in which a polymer of α,β-unsaturated monocarboxylic acid and an amino group-containing sulfonic acid are reacted at high temperature in an aqueous medium to form an amidation.

Furthermore, the form in which it is used is not particularly limited, and the small rice can be used either in the form of a bath liquid or in a solid form such as powder.

It can be used alone or in combination with other cement admixtures.

Examples of cement admixtures that can be used in combination include conventional cement dispersants, air-entraining agents, cement wetting and dispersing agents, swelling agents, waterproofing agents, strength enhancers, hardening accelerators, setting accelerators, and setting retarders. .

The cement admixture of the present invention usually has a solid content of 0.01 to 5% by weight, preferably ρ, 6! ; Alternatively, it is used in a ratio of a=t- to 3 weights. As the amount used decreases, the workability improvement effect decreases, and on the other hand, if it increases excessively, it will have a negative effect on cement hardening #
[It may be harmful.]

Further, the timing of addition to the cement mixture can be appropriately selected depending on the intended use. Specific methods include 5, for example, a method of pre-mixing it with cement, a method of adding it at the same time when mixing cement mixtures such as concrete, a method of adding it after starting stirring with water or other admixtures, and a method of adding it beforehand. Examples include a method of adding the mixture at appropriate intervals after kneading the product. The types of cement to which the hydraulic cement admixture of the present invention can be applied are not particularly limited, and specific examples include 1, for example, ordinary Portland cement. , early strength portland cement,
Medium J1 heat Portland cement, alumina cement, fly ash cement.

Blast furnace cement, silica cement, slag cement.

Examples include various mixed cements.

Thus, according to the present invention, it is possible to obtain a cement composition with good dispersion fluidity and good workability in which slang reduction is significantly suppressed, and a cured product with high strength can be obtained.

The present invention will be explained in more detail with reference to Examples below.

Note that parts and parts in Examples are based on weight unless otherwise specified.

Example 1 Hydraulic properties of sodium salts of acrylic 17(AA)-2-acrylamido-2-methylpropanesulfonic acid (AMPB) coelectric polymers obtained by radical polymerization and having the molar ratios shown in Table 1 Performance as a cement admixture was evaluated according to the following mortar test conditions. The results are shown in Table 2.

[Mortar test]

Adjust the cement mortar with the following composition, and
A mortar test was conducted in accordance with 201, and the admixture addition rate was adjusted to 7'C (the admixture addition rate was adjusted so that the target flow was 230 ± 5 degrees.) The amount of air entrained was; It was measured. The mortar temperature was 20G±2C1, and the temperature during underwater curing for measuring compressive strength was 20C±2C.

Cement: Asano Ordinary Portland Cement Sand:
Oi Ubukawa Sand Cement/Sand Ratio = 1/2 Cement/Water Ratio = 1/0.35 Table 1 [Concrete Test] After mixing cement, water, aggregate, and hydraulic cement admixture according to the following formulation, After kneading for 90 seconds with a forced kneading mixer, the slump and air content were measured, and for the next 30 minutes,
After 60 minutes, each mixture was kneaded and the slump and air content were measured. A sample for compressive strength measurement was taken after 60 minutes. The slump target immediately after kneading is slump 20±
The amount of admixture added was adjusted so that the thickness was 1 cm. How to measure?

JIS A1101 for slump, JI for air volume
SA1116 and compressive strength were in accordance with JIS A1108. In addition, the concrete temperature is 20C ± 20, and the compressive strength is 61.
The regular samples were cured in water at 20±2C.

Concrete mix (in case of addition of admixtures) Table 5 A1 The product of the present invention, which is the same as Example 1, shows the same water-reducing properties with a smaller amount added than the commercially available product, and is desired to be improved over the conventional commercially available product. It can be seen that the slump retention property is also good.

Example 5 Copolymers (to) and (■) used in Example 4 and Example 3
The acrylic acid-acrylamidomethanesulfonic acid C70:30) copolymer sodium salt used in Example 1 was evaluated for general concrete formulation using the following concrete formulation. The results are shown in Table 6.

Concrete mix target slump: 10-! From Table 6, it can be seen that for general use, even when mixed with concrete, it exhibits good performance with a lower addition amount than conventional products, and the strength of the cured product is also good.

Patent applicant: Zeon Corporation

Claims (1)

[Claims] 1, (N-substituted-α,β-unsaturated monocarboxylic cough amide substituted with a sulfonic acid group-containing residue and (blα,
An admixture for hydraulic cement containing a β-unsaturated monocarboxylic acid copolymer or a salt thereof as an active ingredient.