JP2002020147A - Admixture for hydraulic composition and hydraulic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an admixture for a hydraulic composition which comprises both a water-soluble cellulose ether and a polyisoprenesulfonic acid-based compound. SOLUTION: This admixture for a hydraulic composition which has both a water-soluble cellulose ether and a polyisoprenesulfonic acid-based compound as the constituents exhibits good plasticity with a smaller additive amount of the water-soluble cellulose ether as compared with an admixture employing the water-soluble cellulose ether alone as the constituent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydraulic composition admixture particularly suitable for extrusion molding and a hydraulic composition containing this admixture.

[0002]

2. Description of the Related Art
In the hydraulic composition for extrusion molding, as a molding aid (binder) used, alkylcellulose such as methylcellulose, hydroxyalkylcellulose such as hydroxyethylcellulose, and hydroxyalkylalkylcellulose such as hydroxypropylmethylcellulose and hydroxyethylethylcellulose are exclusively used. I have been.

[0003] The reason is excellent plasticity and water retention performance, and by using these cellulose ethers,
It was possible to easily perform extrusion molding even in extrusion molding containing no asbestos.

[0004] However, these cellulose ethers have a problem that the cost is high because a chemical treatment is carried out using purified pulp, which is a natural product, as a raw material. In order to avoid this, it has been attempted to replace a part of the cellulose ether with a water-reducing agent which is one of dispersants for chemically synthesized products such as relatively inexpensive polycarboxylic acids, melamines and naphthalenes. Have been. For example,
JP-A-6-182749 describes a method in which a water-soluble cellulose ether and a modified polycarboxylic acid are used in combination to form an asbestos-free cement extrusion molding admixture,
Japanese Patent No. 2736206 describes a method using a dispersant obtained by using a water-soluble cellulose ether and a salt of a high-condensate of formalin naphthalenesulfonic acid in combination.

[0005] However, these water reducing agents contribute to the dispersion of cement and have a slight effect on the reduction of required water volume.
There was no effect on improving the viscosity and water retention, and there was no effect on reducing the water-soluble cellulose ether. In addition, the quality as an extruded product, such as an increase in the amount used, an uneven distribution of moisture in the extruded product, resulting in a decrease in strength, a cause of coagulation delay or swelling after curing in an autoclave, etc. In some cases, it decreased.

[0006] The present invention is an improvement of the above circumstances, and an admixture for a hydraulic composition capable of reducing the use amount of a water-soluble cellulose ether as a binder while ensuring extrudability and water retention. It is an object of the present invention to provide a hydraulic composition containing the same.

[0007]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, used a polyisoprenesulfonic acid compound in combination with a water-soluble cellulose ether. This has led to the finding that water-soluble cellulose ethers can be reduced, and at the same time, extrudability and water retention are excellent, and the present invention has been accomplished.

Accordingly, the present invention provides (1) an admixture for a hydraulic composition, particularly an admixture for a hydraulic composition for extrusion molding, wherein the water-soluble cellulose ether contains a polyisoprenesulfonic acid-based compound; 2) The admixture for a hydraulic composition, wherein the water-soluble cellulose ether is an alkyl cellulose, a hydroxyalkyl cellulose, or a hydroxyalkylalkyl cellulose.
(3) A hydraulic composition, particularly a hydraulic composition for extrusion molding, comprising the admixture.

Hereinafter, the present invention will be described in more detail. As the water-soluble cellulose ether used for the admixture for hydraulic compositions of the present invention, alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkylalkyl cellulose are preferable. Methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxyethylethylcellulose and the like are used. For extrusion molding, the viscosity of this water-soluble cellulose ether is 20
℃, 1% aqueous solution viscosity measured with a B-type viscometer 100 ~
Although a material having a viscosity of about 50,000 mPa · s is used, it is preferable to use a material having a relatively high viscosity in consideration of cost. When this water-soluble cellulose ether is added to the hydraulic composition, particularly to the composition for extrusion molding, the amount of the water-soluble cellulose ether to be added is usually 100% of the total amount of the hydraulic substance and the aggregate described later.
It is used in the range of 0.1 to 5 parts by weight with respect to parts by weight. However, since this is used as an auxiliary agent of extrusion molding, if it is used to the extent that water retention and plasticity necessary for extrusion molding are provided. It is good, and considering cost etc.,
A range of 0.2 to 3 parts by weight is preferred. If the amount is too small, the required water retention may not be obtained, or the plasticity may be insufficient, and extrusion molding may be difficult. Conversely, if the amount is too large, the cost may increase, or the extrusion molding pressure may unnecessarily increase due to the increase in the adhesive strength.

On the other hand, when a polyisoprenesulfonic acid-based compound is used as an auxiliary in a hydraulic composition, particularly in an extrusion molding composition, an electrostatic repulsion effect due to a large sulfonic acid content and an isoprene skeleton in the main chain are obtained. The dispersibility and plasticity of the kneaded material are improved by the synergistic effect with the steric hindrance effect due to the flexibility of the kneaded material. As a result, it is considered that the amount of the water-soluble cellulose ether added can be reduced.

Further, when the polyisoprenesulfonic acid compound is used as an auxiliary in a hydraulic composition, particularly in an extrusion molding composition, the setting delay time is shorter than when other water reducing agents are used.

The polyisoprenesulfonic acid-based compound comprises isoprene and, if necessary, at least one member selected from other aliphatic dienes and other monomers, and is an aliphatic diene (co) polymer containing isoprene. It is a compound characterized by containing a sulfone group-containing aliphatic diene (co) polymer obtained by sulfonation.

An aliphatic diene other than isoprene constituting a polyisoprenesulfonic acid-based compound (hereinafter sometimes referred to as “other aliphatic diene”) is a carbon atom containing two double bonds in a molecule. 4-7 hydrocarbons,
Examples of the aliphatic diene include 1,3-butadiene, 1,2-butadiene, 1,2-pentadiene,
3-pentadiene, 2,3-pentadiene, 1,2-hexadiene, 1,5-hexadiene, 2,3-hexadiene, 2,4-hexadiene, 2,3-dimethyl-1,
3-butadiene, 2-ethyl-1,3-butadiene,
1,2-heptadiene, 1,3-heptadiene, 1,4
-Heptadiene, 1,5-heptadiene, 1,6-heptadiene, 2,3-heptadiene, 2,5-heptadiene, 3,4-heptadiene, 3,5-heptadiene and the like, as well as branched Various dienes having 4 to 7 carbon atoms are exemplified, and 1,3-butadiene and 1,3-pentadiene are preferred. These aliphatic dienes can be used alone or in combination of two or more. Further, other polymerizable monomers (hereinafter, “other monomers”) may be used for isoprene and the above-mentioned aliphatic diene.
Can be used together.

Examples of the monomer include aromatic compounds such as styrene, α-methylstyrene, vinylstyrene and p-methylstyrene; methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid Methyl, 2-hydroxymethyl acrylate, alkyl esters of acrylic acid or methacrylic acid such as 2-hydroxyethyl methacrylate,
And general formula (1)

[0015]

Embedded image

(Wherein R ¹ , R ² and R ³ represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, which may be the same or different). Alkyl esters represented by the following; acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, anhydrides of dicarboxylic acids or dicarboxylic acids such as itaconic acid; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; Vinyl, vinylidene chloride, vinyl methyl ethyl ketone, vinyl methyl ether, vinyl acetate, vinyl formate, allyl acetate, methallyl acetate, acrylamide, methacrylamide, N-methylolacrylamide, glycidyl acrylate, glycidyl methacrylate, acrolein, allyl alcohol, etc. Saturated group content Compounds; cyclic compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, 2-methyltetrahydrofuran, styrene oxide, butylene oxide, and glycidyl ether; and nitrogen compounds such as vinylpyridine.

These other monomers can be used alone or in combination of two or more.

When these monomers are used in combination, isoprene and other aliphatic dienes are used in an amount of 50% by weight or more,
Preferably 50 to 98% by weight, more preferably 60 to 98% by weight.
95% by weight.

The polyisoprenesulfonic acid compound of the present invention comprises a polymer obtained by polymerizing isoprene alone or one or more of the above-mentioned other aliphatic dienes or monomers, isoprene and the above-mentioned polymer. A block type or random copolymer obtained by copolymerizing one or more other aliphatic dienes with another monomer.

In the polyisoprenesulfonic acid-based compound,
The content of pendant double bonds in isoprene and other diene moieties is preferably 20-60%, preferably 10-60%, more preferably 15-40%. Here, the pendant double bond refers to an ethylenically unsaturated group present outside the main chain of the polyisoprenesulfonic acid-based compound polymer. The weight average molecular weight of the polyisoprenesulfonic acid-based compound is preferably from 1,000 to 200,000, more preferably from 5,000 to 200,000.

When the polyisoprenesulfonic acid-based compound is added to the hydraulic composition, the amount added is usually in the range of 0.01 to 3 parts by weight based on 100 parts by weight of the total of the hydraulic substance and the aggregate. However, when cost is taken into consideration,
A range of 0.02 to 3 parts by weight is preferred. Since these are used especially as an auxiliary agent for the composition for extrusion molding, they may be used to such an extent that dispersibility suitable for extrusion molding is provided. If the amount is too small, the necessary dispersibility may not be obtained. On the other hand, if the amount is too large, the cost may increase, the setting may be delayed or swelling after curing may occur, and the quality may deteriorate.

The hydraulic composition of the present invention contains the above-mentioned admixture, and further contains common components such as hydraulic substances such as cement and gypsum. Here, as the cement used for the hydraulic composition to which the admixture of the present invention is blended, ordinary Portland cement, blast furnace cement, fast-hardening cement, fly ash cement, alumina cement and the like are used. As gypsum, gypsum dihydrate, gypsum hemihydrate and the like are mainly used. The amount of the hydraulic substance used may be such that the required strength is obtained.

In the present invention, an aggregate can be added as required. Specifically, silica stone powder or the like is mainly used. In order to reduce the weight, expanded perlite, superabsorbent resin, styrene beads, inorganic hollow microspheres, organic hollow microspheres, and the like are also used. In addition, the usage amount of the hydraulic substance and the aggregate can be appropriately selected in a range of 10:90 to 100: 0 (weight ratio).

If necessary, a setting retarder for cement or gypsum, a setting accelerator, a thickener, a high-performance AE water reducing agent and the like are also used. The setting amount of the setting retarder and the setting accelerator may be determined in consideration of the state before curing after extrusion molding or the like, but usually the total amount of the hydraulic substance and the aggregate is 10%.
It is used in the range of 0.01 to 10 parts by weight with respect to 0 parts by weight. The thickener and the AE water reducing agent may be used in such an amount that the fluidity of the system can be ensured, and is usually 0.05 to 6 parts by weight based on 100 parts by weight of the total amount of the hydraulic substance and the aggregate. Used in range.

In the case of extrusion molding, it is preferable to add reinforcing fibers. In addition to conventionally used chrysotile-based mineral fibers, wollastonite, sepiolite, sericite and the like are also used, and other pulp fibers and vinylon Fiber, polypropylene fiber, aramid fiber and the like are used. The amount used in this case depends on the desired bending strength and impact strength, but is generally used in the range of 0.1 to 30 parts by weight based on 100 parts by weight of the total amount of the hydraulic substance and the aggregate. You. In particular, when the amount is less than the above range, a sufficient reinforcing effect cannot be obtained, and when the amount is too large, the fibers are not sufficiently dispersed, so that the strength may be reduced.

Water is added to the hydraulic composition, and the amount of water is selected according to the type of the hydraulic composition.
The dose can be a normal dose, but is preferably in the range of 15 to 100 parts by weight based on 100 parts by weight of the total amount of the hydraulic substance and the aggregate.

[0027]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

EXAMPLES, COMPARATIVE EXAMPLES The following materials were used as the cement-based extrusion composition to obtain compositions having the compositions shown in Tables 1 to 3. (1) Cement: ordinary Portland cement (manufactured by Taiheiyo Cement) (2) Silica powder: 250 mesh pass product of silica (3) Pulp: average fiber length 1 mm (4) Polypropylene fiber: fiber length 6 mm (5) Water-soluble cellulose ether: Metros SHV-
P (hydroxypropyl methylcellulose) (20 ° C,
1 wt% aqueous solution viscosity: 13800 mPa · s, manufactured by Shin-Etsu Chemical Co., Ltd. (6) Polyisoprenesulfonic acid compound (manufactured by JSR) Dynaflow K106, Dynaflow Z102 (7) Polycarboxylic acid compound (manufactured by Onoda) Coreflow NF -100 (8) Water: tap water Materials other than water were mixed with a Henschel mixer for 3 minutes, a predetermined amount of water was added, and the mixture was further mixed for 2 minutes. Thereafter, the mixture was kneaded in a 10 L kneader-ruder for 5 minutes, and extruded. In this case, a flat plate was prepared using a die shape of 6 × 75 mm, and the surface state was observed. The surface condition was measured visually, and it was observed whether the extruded product had a smooth surface without cracks.

Further, using a die shape of 20 × 40 mm,
The above kneaded material was extruded, primary cured at 65 ° C. for 15 hours, and then autoclaved at 170 ° C. for 8 hours, and then the flexural strength and compressive strength were measured. The measuring method is JI
According to SR5201. The results are shown in Tables 1 to 3.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

From these results, it can be seen that when a polyisoprenesulfonic acid-based compound is used as the water-soluble cellulose ether, extrusion molding with an excellent surface state is achieved without impairing other physical properties as compared with the case where the water-soluble cellulose ether is used alone. It turns out that a thing is obtained. Also, when using a polyisoprenesulfonic acid-based compound in the water-soluble cellulose ether, without impairing other physical properties than when using the same amount of the polycarboxylic acid-based compound in the water-soluble cellulose ether, after primary curing It is understood that an excellent extruded product can be obtained without causing poor curing.

[0034]

According to the present invention, by using a polyisoprenesulfonic acid-based compound in combination with a water-soluble cellulose ether, the amount of the water-soluble cellulose ether added is smaller than when using the water-soluble cellulose ether alone. High plasticity can be obtained.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08L 15/00 C08L 15/00 // C04B 103: 46 C04B 103: 46 (72) Inventor Tsutomu Yamakawa Nakatsugi-gun, Niigata 28-1 Nishi-Fukushima, Nishifukushima, Fukushima, Japan Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory F-term (reference) 4G012 PA03 PA22 PA24 PB31 PB33 PB40 4G054 AA01 BD00 4J002 AB031 BB262 GL00

Claims (5)

[Claims] 1. An admixture for a hydraulic composition, wherein the water-soluble cellulose ether contains a polyisoprenesulfonic acid compound. 2. The admixture for a hydraulic composition according to claim 1, wherein the water-soluble cellulose ether is an alkyl cellulose, a hydroxyalkyl cellulose, or a hydroxyalkyl alkyl cellulose. 3. The hydraulic composition for extrusion molding according to claim 1.
Or the admixture for hydraulic compositions according to 2. 4. A hydraulic composition comprising the admixture according to claim 1 or 2. 5. The hydraulic composition according to claim 4, which is for extrusion molding.