JP2000302520A - Cement-based joint material and cement-based joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement cased joint material capable of effectively controlling efflorescence. SOLUTION: The cement based joint material comprises at least one of cement based inorganic powder containing silicate fine powder, polymer dispersion for admixing water soluble amino resin with cement and re-emulsifying type powdery resin. And the cement based joint has fine pores having a 0.1-1.0 μm diameter of fine pore at a rate of <=0.03 cm3/g of fine pore volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel cement joint material and a cement joint.

[0002]

2. Description of the Related Art In general, cement-based jointing materials are composed of mortar mainly composed of cement and sand, and are used for tiled finishing or glass block finishing of exterior or interior of concrete structures. It is used.

[0003] The cement-based jointing material is liable to cause the efflorescence phenomenon on the cured jointing material surface due to calcium contained in the cement. That is, a large amount of calcium ions are eluted by the hydration reaction of the cement, and furthermore, the calcium ions are gushered to the joint surface and react with carbon dioxide in the air to form a carbonate. This whitening phenomenon causes stains on joints or stains or discoloration on adjacent tiles, and consequently significantly impairs the appearance of the finished surface.

[0004] For this reason, various methods for preventing the whitening phenomenon have been proposed. For example, a method of preventing the movement of water due to water absorption by making the joint material itself water repellent (Japanese Patent Laid-Open No. 52-274)
No. 24), a method for making the efflorescence less noticeable by adding a dye (Japanese Patent Laid-Open No. Hei 2-263751), and a method for improving the quality of mortar or concrete by adding a water-soluble amino resin (Japanese Patent Publication No. 6-74160). ) Etc. are known.

[0005]

However, in any of these prior arts, the effect of the cement-based joint material on preventing the efflorescence is still insufficient, and there is room for further improvement.

Accordingly, an object of the present invention is to provide a cement joint material which can effectively suppress the efflorescence phenomenon.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the prior art, and as a result, have found that a cement joint material having a specific structure and a cement joint having a specific structure can achieve the above object. Under the heading, the present invention has finally been completed.

That is, the present invention relates to the following cement joint material and cement joint.

1. A cement-based joint material comprising a cement-based inorganic powder containing a siliceous fine powder, a water-soluble amino resin, and at least one of a polymer dispersion for cement admixture and a re-emulsifiable powder resin.

[0010] 2. 0.1 to 5 parts by weight of a water-soluble amino resin and at least one of a polymer dispersion for cement admixture and a re-emulsifying type powder resin with respect to 100 parts by weight of a cement-based inorganic powder containing 40 to 80% by weight of a siliceous fine powder. 1 to 5 parts by weight as a solid content.

3. A cement joint characterized in that pores having a pore diameter of 0.1 to 1.0 μm are present at a pore volume of 0.03 cm ³ / g or less.

4. A cement joint obtained by curing the cement joint material according to the above item 1 or 2, and a kneaded material containing water and aggregate.

5. Item 5. The cement joint according to item 4, wherein the pores having a pore diameter of 0.1 to 1.0 μm are contained in a cement joint.
A cement joint which is present at a ratio of not more than 03 cm ³ / g.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION 1. Cement-based joint material The cement-based joint material of the present invention is 1) a cement-based inorganic powder containing a siliceous fine powder, 2) a water-soluble amino resin, and 3) a polymer disperser for cement admixture. And at least one of a re-emulsifiable powder resin. Hereinafter, each component will be described. 1) Cement-based inorganic powder containing siliceous fine powder Cement-based inorganic powder is substantially composed of cement and siliceous fine powder.

The cement is not particularly limited, and a known cement can be used. For example, various Portland cements such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderately heated Portland cement, sulfate-resistant Portland cement, white Portland cement, etc. Can be used. Alternatively, it is also possible to use a mixed cement in which an inorganic powder such as blast furnace slag, fly ash, silica or the like is mixed with these cements.

The siliceous fine powder is not particularly limited as long as it basically has latent hydraulic properties, and known powders can be used. For example, blast furnace slag, fly ash, silica fume and the like which are usually used as a cement mixture can be used. The particle size of these fine powders is not particularly limited.
0 cm ² / g or more, preferably used as more than 6000 cm ² / g. By using a fine powder in this range, reduction of calcium ions in the cured product, densification of the cured product structure, and the like can be further promoted. The particle size adjustment can be performed by a known pulverizing method, classification by wind force, centrifugal force or the like, alone or in combination.

The mixing ratio of the siliceous fine powder may be appropriately set according to the type of cement used and the like, but is usually relative to the total of the cement and the siliceous fine powder (ie, in the cement-based inorganic powder). ) It may be about 40 to 80% by weight, preferably 50 to 70% by weight. In the joint material of the present invention, if the compounding ratio of the siliceous fine powder is set in the above range,
Since the effect of reducing calcium ions in the cement-based joint (hardened body) is further enhanced, and the capillary gap can be sufficiently closed, the efflorescence phenomenon can be more effectively suppressed. In addition, since sufficient strength is obtained for the joint material itself, the durability of the tile finished surface can be further increased. 2) water-soluble amino resin amino resin, urea (urea), a melamine, guanamine, a thermosetting resin obtained by formaldehyde by the addition condensation reaction a compound having an amino group such as aniline (-NH _2), for example, Urea resins, melamine resins, urea melamine resins, guanamine resins, aniline resins and the like can be mentioned. In the present invention, water-soluble amino resins are used. For example, a compound mainly composed of an initial condensate such as a dimer and a trimer can be used as the water-soluble amino resin. As the water-soluble amino resin, a powdery resin can be generally used. By using a water-soluble amino resin, the efflorescence phenomenon can be effectively prevented. In particular, the water-soluble amino resin is first dissolved in kneading water,
Thereafter, at the stage where the joint material hardens, the polymer is polymerized and precipitated as a water-insoluble amino resin, thereby closing the capillary void, which is a passage for calcium ions, and physically suppressing the efflorescence phenomenon.

The mixing ratio of the water-soluble amino resin can be appropriately set according to the kind of the water-soluble amino resin to be used.
The amount may be about 1 to 5 parts by weight, preferably 0.5 to 3 parts by weight. By setting the content in the above range in the joint material of the present invention, it is possible to effectively close the capillary voids in the cement-based joint (hardened body) and to densify the hardened body itself, thereby more effectively suppressing the efflorescence phenomenon. It is possible to do. 3) Polymer dispersion / re-emulsifiable powder resin for cement admixture In the present invention, at least one of a polymer dispersion for cement admixture and a re-emulsifiable powder resin (both are also collectively referred to as "polymer for cement admixture") is used. .

Examples of the polymer dispersion for admixing with cement include rubber latex such as natural rubber latex, synthetic rubber latex and rubber asphalt latex; ethylene vinyl acetate, polyacrylate,
Resin emulsions such as styrene acrylate, asphalt, rubber asphalt and the like can be mentioned.

Examples of the re-emulsifying powder resin include resins such as ethylene vinyl acetate, styrene acrylate, polyacrylate, and vinyl acetate / veova / acrylate copolymer.

These polymers for cement admixture are JIS
-A-6203 can be used, and a commercially available product can be used as it is. In addition, one or more of these cement admixture polymers can be used. Since the polymer for cement admixture has a function of closing the capillary void by forming a polymer film in the capillary void of the hardened body, it is possible to suppress the movement of calcium ions that cause a white spot phenomenon. At the same time, the addition of the polymer for cement admixture improves the adhesion to the tile side surface or the tiled mortar, and suppresses the generation of gaps due to peeling of a joint material that can be a water movement path other than the capillary voids of the cured body. Can also.

The mixing ratio (solid content) of the polymer for cement admixture can be appropriately determined according to the kind of the polymer for cement admixture used, and usually, 1 part by weight per 100 parts by weight of the cement-based inorganic powder. The amount may be about 5 to 5 parts by weight, preferably 2 to 4 parts by weight. Within this range,
In particular, the movement of calcium ions can be effectively prevented, so that the efflorescence phenomenon can be more effectively prevented.

In the present invention, in addition to these components, various additives such as an expanding material for admixing with cement, a shrinkage reducing agent, and a thickening agent may be added, if necessary.

The cement type joint material of the present invention can be used in the same manner as a known joint material. That is, to prepare a kneaded material containing water and aggregate in the cement-based joint material,
By curing this, a cement joint is formed.

As the aggregate, a known aggregate used for joints can be used. For example, dry silica sand, limestone sand and the like can be mentioned. The mixing ratio of the aggregate is not particularly limited, and may be appropriately set depending on the type and size of the aggregate, but is usually 50 to 200 with respect to 100 parts by weight of the cement-based inorganic powder.
What is necessary is just about a weight part. The size (particle size) of the aggregate is not particularly limited, and may be generally about 0.1 to 2 mm.

The amount of water can be appropriately adjusted according to the composition of the cement composition, desired properties, and the like, but is usually 30 to 60 parts by weight based on 100 parts by weight of the cement-based inorganic powder.
Parts by weight, preferably 40 to 50 parts by weight. In addition, the kneading method of the cement-based joint material and water, the joint forming method, etc., according to the construction site, the type of the base material, etc., according to a known joint forming method or a method adopted in the construction method. good. 2 Cement-based joint The cement-based joint (cured body) of the present invention has a pore diameter of 0.1.
It is characterized in that pores having a diameter of 1.0 to 1.0 μm are present at a pore volume of 0.03 cm ³ / g or less.

[0027] The present in invention joints, has a large number of pores, among which even pore diameter 0.1~1.0μm pore pore volume 0.03 cm ³ / g or less (preferably 0.02 cm ³ / g
Below). The pore volume of pores having a pore diameter of 0.1 to 1.0 μm is 0.03 cm ³
If the amount exceeds / g, the whitening phenomenon may occur.

The material of the cement joint of the present invention is not particularly limited as long as the above-mentioned structure can be achieved. However, 1) silica-based fine joints are particularly preferable in that the above-mentioned structure can be easily obtained. A cement-based joint material containing at least one of a cement-based inorganic powder containing powder, 2) a water-soluble amino resin, and 3) a polymer dispersion for cement admixture and a re-emulsifiable powder resin, that is, the cement-based joint of the present invention. The material can be suitably used.

The cement joint obtained by hardening the cement joint material and the kneaded material containing water and aggregate has a small amount of calcium ions and a relatively dense structure, so that the efflorescence phenomenon is effective. Is prevented. Among such cement joints, those having the above structure, that is, pores having a pore diameter of 0.1 to 1.0 μm have a pore volume of 0.03
Cement-based joints present at a rate of not more than cm ³ / g are most desirable in that they can more effectively prevent the efflorescence phenomenon. That is, in the cement-based joint having such a material and structure, the efflorescence phenomenon is effectively prevented or suppressed from both the composition side and the structure side.

[0030]

In a cement concrete material, a large amount of calcium ions is eluted from the cement particles into the kneading water by the hydration reaction of the cement, and calcium hydroxide is precipitated by becoming supersaturated. For this reason, a large amount of calcium hydroxide is present in the capillary space in the cured product, but the supersaturated state of calcium ions is maintained unless the calcium hydroxide is consumed. As water moves through the capillary voids, minute cracks, and the like due to drying and water leakage of the surface of the cured body, a solution containing supersaturated calcium ions also moves to the surface of the cured body. On the surface of the cured body, calcium ions are carbonated by contacting carbon dioxide in the air, and are precipitated as water-insoluble calcium carbonate. As a result, the efflorescence phenomenon occurs.

The present inventor has studied and studied in detail the mechanism of such a phenomenon, and found that the following two points can prevent the phenomenon. That is, if at least one of 1) reducing the amount of calcium ions in the cured product itself and 2) blocking the movement path of calcium ions can be realized, it is possible to prevent the efflorescence phenomenon. Based on such knowledge, the inventors succeeded in developing the cement joint material and the cement joint of the present invention.

[0032]

According to the cement joint of the present invention, the pores having a pore diameter of 0.1 to 1.0 μm have a pore volume of 0.03 cm ³ /
Due to the unique structure of being present in a proportion of g or less, in particular, the movement of calcium ions can be effectively prevented, whereby the efflorescence phenomenon can be effectively suppressed or prevented.

Since the cement-based joint material of the present invention is composed of the above-mentioned specific composition, when the joint is formed using the cement-based joint material, the amount of calcium ions can be reduced, and at the same time, the structure can be more reliably formed. Obtainable. Therefore,
When the joint material of the present invention is used, and when the above structure is adopted, the effect of reducing calcium ions and the effect of inhibiting calcium ion migration are synergistically obtained, so that it is possible to more effectively prevent the efflorescence phenomenon. Become.

The cement-based joint material of the present invention can be suitably used for filling in joints in, for example, tile finishing of exterior or interior of concrete structures, glass block finishing, and the like.

[0035]

The features of the present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these embodiments.

Example 1 A joint material was prepared using the cement compositions shown in Table 1.
Specifically, the above cement composition was kneaded with water in a Hobart mixer under the conditions of a temperature of 20 ° C. and a humidity of 85% RH, to thereby prepare test pieces having a predetermined shape as shown in Test Examples described later.

[0037]

[Table 1]

Each of the materials shown in Table 1 had the following products and physical properties. (1) Ordinary cement Ordinary Portland cement (manufactured by Sumitomo Osaka Cement Co.) (2) Fine slag powder Blaine fineness 4000 cm ² / g (manufactured by Sumitomo Kashima Mineralization Co.) (3) Water-soluble urea resin Formaldehyde to 1 mol of urea (1) Re-emulsifiable powder resin vinyl acetate / veova / acrylate copolymer resin (Clariant Polymer) (5) Dry silica sand No. dried silica sand (manufactured by Hihyo Mining Co., Ltd.) Test Example 1 The pore size distribution of each specimen was measured.

A cylindrical specimen having a diameter of 5 cm × 10 cm was prepared and cured at a temperature of 20 ° C. and a relative humidity of 85% RH until the age of 7 days, and a measurement sample of about 5 mm × 5 mm × 5 mm was collected from the center of the specimen. , D-drying (drying under reduced pressure),
Pore diameter 0.003 ~ by mercury intrusion porosimeter
The pore diameter distribution of 400 μm was measured, and the pore diameter was 0.1 to
The pore volume of 1.0 μm was calculated. Table 1 shows the results.

Test Example 2 A bleach accelerating test (semi-immersion method) was performed.

After preparing a 12.5 cm × 12.5 cm × 1 cm plate-shaped specimen, the specimen was cured at a temperature of 20 ° C. and a humidity of 85% RH until the age of 7 days. After coating the four sides of the obtained specimen with an epoxy resin, the specimen is half-immersed in an aqueous solution (5% by weight of Na ₂ SO ₄ + saturated Ca (OH) ₂ ) at a temperature of 5 ° C. to a half in the thickness direction of the specimen. Then, the presence or absence of the efflorescence phenomenon was observed. Table 1 shows the results. In Table 1, the results were evaluated as ○: no efflorescence was generated, Δ: a small amount of efflorescence was generated, x: a large amount of efflorescence was generated.

Test Example 3 A white flower accelerating test (ALC measuring method) was performed.

Using a cut commercial ALC board (Shizukalite ordinary type manufactured by Onoda ALC Co., Ltd .: 50 mm thick)
Make an ALC measure of 0mm x 500mm x 500mm,
Using a polymer cement mortar according to the Japanese Society of Architects and Finishers, ALC panel on-site tiling method (draft) and the commentary (1997), the outer surface of the above ALC basin was treated with a thickness of 5 mm. After curing, a dark tile was applied with improved mosaic application using a commercially available tiled mortar (NS cement), and then a cement-based joint material was prepared at the mixing ratio shown in Table 1, and the joint was filled. After curing indoors for 2 weeks, the ALC basin was filled with water, exposed to the outdoors as it was, and the degree of occurrence of the efflorescence phenomenon at the joints was observed. Table 1 shows the results. In Table 1, the results were evaluated as ○: no efflorescence was generated, Δ: a small amount of efflorescence was generated, x: a large amount of efflorescence was generated.

Test Example 4 The amount of calcium eluted was measured.

A specimen having a diameter of 5 cm × 10 cm was prepared, cured at a temperature of 20 ° C. and a humidity of 85% RH until the age of 7 days, and then the specimen was pulverized to a particle size of 1.2 to 2.5 mm. The adjusted sample was used as a measurement sample. 10 g of this sample was precisely weighed and shake-extracted in 100 cm ³ of distilled water for 16 hours. The extract is filtered and the amount of calcium ion eluted is determined by ICP.
(High frequency inductively coupled plasma emission spectrometry). Table 1 shows the results.

Continued on the front page (72) Inventor: Akio Sugiura 7-55 Minamionkajima, Taisho-ku, Osaka-shi, Osaka Sumitomo Osaka Cement Co., Ltd. Cement and Concrete Research Laboratory (72) Inventor: Shigehiro Kobayashi Minami, Taisho-ku, Osaka, Osaka 7-55, Enkajima Sumitomo Osaka Cement Co., Ltd. Cement and Concrete Research Laboratories (72) Inventor Mikio Wakasugi 1-chome, Midami-shiro-cho, Chiyoda-ku, Tokyo Sumitomo Osaka Cement Co., Ltd. (72) Inventor Nobuo Tsubouchi Chiba 1-5-1, Otsuka, Inzai City, Pref., Japan Takenaka Corporation Technical Research Institute (72) Inventor Nobuo Murakami 1-5-1, Otsuka, Inzai City, Chiba Prefecture, Japan Takenaka Corporation Technical Research Institute (72) Inventor Hajime Okamoto 1-5-1, Otsuka, Inzai City, Chiba Prefecture Inside the Technical Research Center, Takenaka Corporation (72) Inventor Toshiro Honagawa 1-5-1, Otsuka 1-chome, Inzai City, Chiba Prefecture F-term in the Technical Research Center, Takenaka Corporation (reference 4G012 PA27 PA28 PA29 PB20

Claims (5)

[Claims] 1. A cement-based inorganic powder containing a siliceous fine powder, 2) a water-soluble amino resin, and 3) a polymer dispersion for cement admixture and at least one of a re-emulsifiable powder resin. Characterized cement joint material. 2. 1) 100 parts by weight of a cementitious inorganic powder containing 40 to 80% by weight of a siliceous fine powder, 2) 0.1 to 5 parts by weight of a water-soluble amino resin, and 3) Polymer dispersion for cement admixture. And 1 to 5 parts by weight of a solid content of a re-emulsifiable powder resin. 3. A cement joint comprising pores having a pore diameter of 0.1 to 1.0 μm and a pore volume of 0.03 cm ³ / g or less. 4. A cement joint obtained by curing the cement joint material according to claim 1 or a kneaded product containing water and aggregate. 5. The cement joint according to claim 4, wherein:
And the pores having a pore diameter of 0.1 to 1.0 μm are 0.03c.
A cement joint which is present at a ratio of m ³ / g or less.