JPH0551282A - Curing finishing method for alkaline inorganic cured products - Google Patents

Abstract

(57) [Summary] [Structure] An aqueous resin dispersion, and an alkaline thickening polymer compound, or an aqueous dispersion comprising each of the dispersions and compounds described above and a pigment. The alkali thickening type coating composition of 1) is applied to the surface of the alkali curable inorganic cured body, or the coating composition is cured before the composition for the alkali curable inorganic cured body is condensed. A method of curing and curing an alkaline inorganic cured body, which comprises coating the cured body therein. [Effect] The method of the present invention has a great merit that it is excellent in workability from the point of using an aqueous composition and that there is little possibility of environmental pollution. In addition, in the method of the present invention, immediately after the alkaline inorganic cured body is cast (including construction and molding), the cured body is condensed even in a state where the cured body is not condensed. Even after that, it can be said that it is extremely practical in that it is possible to form a curing film and a finishing film having excellent durability at the same time with only one coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful curing finishing method for an alkaline inorganic cured body. More specifically, the present invention provides a specific aqueous alkaline thickening type coating composition, which comprises an aqueous resin dispersion and an alkaline thickening polymer as an essential component, on the surface of an alkaline inorganic cured body. The present invention relates to a method for curing and finish-protecting so-called alkaline inorganic hardened materials such as cement concrete, cement mortar, calcium silicate board, cement asbestos board, wood cement board or lightweight cellular concrete, which are composed of cement.

[0002]

2. Description of the Related Art Conventionally, various water-soluble substances such as a water-based coating agent and a water retention agent, which form a dry film during curing of a cement skeleton or a molded body, are applied to the surface to prevent water evaporation and dry. Studies have been conducted to prevent the outing and increase the strength of the obtained cured product.

Although such a means has a dry-out preventing effect, it is mixed with a water-soluble substance which precipitates from an alkali-curable substance such as cement until it dries, or if it is dried, it is white flower ( Efflorescence) and laitance are liable to occur, so it was not possible to achieve a beautiful finish.

On the other hand, although attempts have been made to apply an organic solvent-soluble coating composition, in this case, the organic solvent is likely to violate the alkaline inorganic cured material, although it is a beautiful finish. However, it is not preferable from the viewpoint of environmental destruction due to evaporation of the solvent.

[0005]

As described above, as long as the above-mentioned prior art is followed, there is no satisfactory curing method and finish protection method for the alkaline inorganic cured body.

[0006] Therefore, the problem to be solved by the present invention is to prevent the dry-out by simply applying it at the time of curing an alkaline inorganic cured body such as a cement body or a molded body,
It is to develop a curing finishing protection method for an alkaline inorganic cured body, which can prevent the occurrence of white sinter and leitance, and can also make a beautifully finished finish with a substrate protecting effect.

[0007]

Therefore, the present inventors have
In view of the advantages and disadvantages of the prior art, and focusing on the problems to be solved by the invention described above,
As a result of intensive studies, an alkaline thickening type aqueous coating composition containing two specific types of components, an aqueous resin dispersion and an alkali thickening polymer compound, as essential components is treated under an alkaline condition during curing. For the first time, the object of the present invention can be achieved by coating on the surface of an inorganic cured body, and therefore, such a method is exactly the best method as a curing finish for an excellent alkaline inorganic cured body. The present invention has been completed and the present invention has been completed.

The present invention has a low viscosity at the time of coating and a good coating workability, and after coating, the base material-coating interface is remarkably thickened by the alkalinity of the base material. Therefore, it is possible to form a coating film that doubles as a curing coating film and a finish coating film by suppressing the precipitation of alkaline substances and the like from the base material with a single coating. This is a useful curing finishing method.

That is, in the present invention, each of the aqueous resin dispersion (A) and the alkali thickening polymer (B) is an essential component, and if necessary, a pigment is further included. It is intended to provide a novel and useful curing finishing method for an alkali-inorganic cured product, which comprises coating an aqueous alkali-thickening type coating composition on the surface of an alkali-inorganic cured product.

The aqueous resin dispersion (A), which is the main constituent of the coating composition, will be described below. This aqueous resin dispersion (A) reduces evaporation of water from the inside of the cured body when the coating composition is formed into a dry film, and suppresses precipitation of a water-soluble substance over a long period of time. It is a component for preventing the invasion of acidic substances and the like from the outside of the cured body and the weathering.

Therefore, the aqueous resin dispersion (A) is required to have excellent alkali resistance, water resistance and durability of the film. Specifically, a water-soluble or water-dispersible epoxy resin is required. , Urethane resin, acrylic
Examples thereof include acrylic styrene resin, polyolefin resin, fluorine resin, vinyl acetate resin, and styrene butadiene resin.

Of these, considering the weather resistance of the resulting coating film, it is preferable to use an acrylic resin, an acrylic / styrene resin, or a fluorine resin. Further, considering the film-forming property at room temperature and the compatibility with the alkali thickening polymer (B) which will be described later, it is preferable to use an acrylic resin or an acrylic / styrene resin.

As the form of the resin, an emulsion polymer is preferable in consideration of viscosity, solvent content and molecular weight.
Further, as the glass transition temperature of the resin, in consideration of durability, stain resistance and film forming property of the obtained coating film, it is 0 to
It is preferably in the range of 50 ° C.

Next, the alkali thickening polymer (B), which is the other main constituent, will be described. When the coating composition used in the present invention is easily applied with a low viscosity at the time of coating, and the alkali thickening polymer (B) is applied to the surface of the alkaline inorganic cured body,
Under the high alkalinity of the interface, thickening the alkali,
It is an essential component for preventing the alkaline substance from entering the coating film from the cured product until the coating composition forms a dry film.

From this point of view, the alkali thickening polymer (B) generally has a pH of 9 or more, and further, p
It is desirable to use a compound in which H rapidly increases in viscosity at 10 or more, and specifically, it is desirable to use a polycarboxylic acid-based resin and a cellulose derivative such as methylcellulose or hydroxyethylcellulose.

Further, considering the water resistance and alkali resistance of the obtained coating film and the curing retardation property of the alkaline inorganic cured product, it is preferable to use a polymer having a high molecular weight as small as possible. It is desirable to use an alkali thickening type emulsion polymer containing a large amount of groups.

The above-mentioned use ratios of the aqueous resin dispersion (A) and the alkali thickening polymer (B) are as follows:
It is determined by the balance between the alkali thickening property of the resulting composition and the water resistance and alkali resistance of the coating film, and although there is no particular limitation, the ratio (A) :( B) is 90 in terms of solid content. It is preferable that it is within the range of: 10 to 99.9: 0.1.

Next, a component which is a pigment is appropriately used, if necessary, for the purpose of improving the hiding property, hardness, weather resistance and substrate adhesion of the resulting coating film and coloring. In consideration of various physical properties of the resulting coating film, the amount used is 100% solid content of the resin (binder).
It is preferably 100% by weight or less, more preferably 50% by weight or less with respect to parts by weight.

The pigment used is not particularly limited,
Known and commonly used ones are used. Specifically, various metal oxides such as titanium oxide and zinc oxide; various extender pigments such as talc, mica, calcium carbonate, clay and barium sulfate; red iron oxide Various iron oxides, various organic or inorganic color pigments such as carbon and phthalocyanine blue are particularly representative, and these may be used alone or in combination of two or more kinds.

Further, various commercially available color pastes in which color pigments are previously dispersed in water can also be used. However, in consideration of long-term deterioration, use of organic pigments and pigments having low alkali resistance should be avoided as much as possible.

In forming a coating, a thickener, a defoaming agent, a leveling agent, a film-forming aid, a wetting agent, a crosslinking agent, an antiseptic / antifungal agent, a thixotropic agent, a water repellent, a pigment dispersant, Of course, various known and conventional additives such as freeze stabilizers, UV absorbers, antioxidants or flame retardants can also be used.

From the gist of the present invention, it is desirable to use the thus obtained aqueous alkaline thickening coating composition having a pH of 8 or less, and further, a pH of 7.5 or less. As for 1,000 in this pH range
It is preferably cps or less.

Further, when the pH is 10 or more, it is preferable that the viscosity is alkali-thickened to 2,000 cps or more. The solid content of the composition is not particularly limited, but is preferably 20% or more, further preferably 30% or more.

The coating amount of the coating composition is selected according to the type or condition of the base material and the purpose of coating, and is not particularly limited, but it is solid content. It is preferably ²⁰ to 400 g / m ² .

The coating method of the coating composition thus obtained is not particularly limited, and a brush, a roller, a roll coater, a flow coater, a shower ring or a spray coating may be used for coating. It is done properly.

At that time, if it is necessary to apply a thick coating depending on the purpose, the coating may be repeated twice or three times. There are no particular restrictions on the drying conditions, either normal temperature drying or forced drying may be used, and in the case of a molded body, of course, it may be a form utilizing heat such as steam curing or autoclave curing. is there.

It is time to coat the coating composition on the surface of the cured inorganic inorganic material, but also from the point of the present invention, the composition for the cured inorganic inorganic material is cast (including construction or molding). After that, as soon as possible,
It is desirable to paint it. For example, on the mold surface (constraint surface) of a cement concrete skeleton or molded body,
Immediately after demolding, the release surface (that is,
It is desirable to apply the paint immediately after the casting (including the construction, etc.) on the casting surface), the mortar finish surface, and the flat construction portion of the floor.

If the finish appearance of the coating is to be emphasized, it is more preferable to apply the coating after the composition for the inorganic cured body is condensed and the water content on the surface is reduced, but according to the method of the present invention, Even if it is applied before the composition is solidified, a product with a satisfactory finished appearance can be obtained.

Therefore, the timing of coating should be selected according to the purpose and is not particularly limited, but from the point of the present invention, it is not possible to coat before the composition for the inorganic cured body is condensed. Is particularly preferable.

It is needless to say that a known coating agent may be overcoated on the coating film obtained by the method of the present invention.

[0031]

EXAMPLES Next, the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples, but all are based on weight unless otherwise specified.

Reference Example 1 (Preparation example of coating composition) "Boncoat 3981" [100 parts acrylic emulsion polymer manufactured by Dainippon Ink and Chemicals, Inc .; solid content = 50%] "Chissosizer CS-12""[Chizo Co., Ltd.'s film-forming aid] 7 parts" Nopco 8034L "[San Nopco's defoamer] 0.1 part 5% dilute hydrochloric acid x" Bestside FX "[Dainippon Ink and Chemicals, Inc.] 0.1 part antiseptic made by Co., Ltd.] “Cellosize QP4400” (hydroxyethyl cellulose made by 0.1 part of Union Carbide Company, USA) “Boncoat 3750 (made by Dainippon Ink and Chemicals, Inc. 0.8 parts Lucari thickened acrylic emulsion polymer; solid content = 23%) 14% ammonia water y ────────────────────────── ────────── Next, addition and stirring, however, x; amount to be adjusted so that pH is 6.0 y; amount to be adjusted so that pH is 7.2 Below, the composition for clear coating thus obtained, S
It is abbreviated as -1.

Reference Example 2 (same as above) "Boncoat EC-880" [Acrylic / styrene emulsion polymer manufactured by Dainippon Ink and Chemicals, Inc. 100 parts; solid content = 50%] Butyl carbitol acetate (film formation) Auxiliary agent) 7 parts "Nopco 8034L" 0.1 part "Disperse Color SD-9020" [Carbon dispersed pigment manufactured by Dainippon Ink and Chemicals 2 Co., Ltd.] 5% dilute hydrochloric acid x "Bestside FX" 0.1 part "Primal TT-935" (American Rohm and Her 0.6 part Alkali-thickening type acrylic emulsion polymer; solid content = 25%, manufactured by Susha Co., Ltd.) 14% ammonia water y ── ───────────────────────────────── The above is added and stirred sequentially, but x; Amount to be adjusted y; pH will be 6.7 The amount to be adjusted below thus obtained composition for black paint, S-2
Is abbreviated.

Reference Example 3 (same as above) "Boncoat EC-880 100 parts Butyl carbitol acetate 7 parts" Disperse Color SD-9020 " 2 copies "Best Side FX" 0.1 part ─────────────────────────────────── Hereinafter, the control composition thus obtained is abbreviated as S′-1.

Examples 1 and 2 and Comparative Example 1
And 2 The above-mentioned aqueous alkaline thickening coating composition (S-1)
And (S-2), and, on the other hand, a control composition (S'-
Perform the following tests using 1) and, and
Collectively shown in Tables 1 and 2.

However, the outline of each test is as follows. Test method (a) A flexible board having a thickness of 3 mm was coated with 100 g / m ² of a three-fold dilution of “HI-FLEX NS-1000” (sealer manufactured by Nippon Kasei Co., Ltd.) over a day and night. It was dried.

Then, a colored cement mortar having the following composition was applied onto it with a trowel to make it smooth, and immediately, a solid content of 40 was applied to each of them. %, The compositions (S-1), (S-2) and (S'-1) adjusted with water were separately spray-applied at 150 g / m ² respectively, and 2
It was dried at 0 ° C. under the condition of 60% RH.

For comparison, an unpainted one was also tested.
I took the test. << Mortar mix >> Ordinary Portland cement [Osaka Cement Co., Ltd. product] 100 parts [ED-100] [Toda Bengal Co., Ltd. red iron oxide] 8 parts  No. 9 silica sand   100 parts water 45 parts ────────────────────────────────── Knead the above and W / C (water / Cement ratio) 45
%.

(B) Cement concrete having the following composition was cast into a mold having a size of 10 × 10 × 40 cm, and then the cast surface was immediately finished with a trowel to make it smooth, and As in the case of b), the composition (S-1),
(S-2) and (S'-1) were separately applied onto the finished surface.

Then, at 20 ° C. and 65% RH
After curing for 2 days under the following conditions, the composition is demolded, and the composition (S-1), (S-2) is immediately formed on the demolding surface (constraining surface).
And (S'-1) are respectively 150 g / brush with a brush.
m ^{2 was} painted.

For comparison, an unpainted product was also subjected to the test. <Concrete mixture> Ordinary Portland cement 325 parts Fine aggregate (using washed sea sand from Kinokawa off Wakayama prefecture) 780 parts Coarse aggregate (using crushed stone from Takarazuka, Hyogo prefecture) 1070 parts "Pozoris 100N" (AE agent) 9 parts water 175 parts ────────────────────────────────── The above mixture is kneaded to give a W / C of 54. %, The air entrainment amount was 4%, and the slump was 18 cm.

Evaluation Method (1) Finished Appearance: The state after being air-dried for 14 days under the above conditions was visually determined. (2) Water resistance ……………… For a base material that is 14 days old,
After being completely submerged in 0 ° C. water for 3 days, pulled up and dried for 3 days, the state of white sinter was visually determined. (3) Accelerated weather resistance: Visually judge the condition after 500 hours of testing with a sunshine weather meter. (4) Dry-out resistance: In (b) above, after removing the mold and coating, the sample weight was measured in 3 days, and then
After air-drying for 23 days (that is, material age 28 days), the weight is measured again to calculate the weight reduction rate. (5) Neutralization resistance ………… In (b) above, the specimen with a material age of 28 days was used in an atmosphere with a carbon dioxide concentration of 5% by volume, and at 30 ° C. and 60% RH. After standing for 3 months underneath, each test piece was broken, a phenolphthalein solution was applied to the cross section, and the thickness from the surface of the layer that did not develop color was measured.

(Each of them is the average of three points.)

[0044]

[0045]

[0046]

Thus, the method of the present invention basically comprises
Since an aqueous composition is used, the workability is excellent and the possibility of environmental pollution is low.

In addition, immediately after the alkaline inorganic hardened body is cast (including construction and molding), even if it is in a state where it has not been condensed yet, or even after it has been condensed, It can be said that this is an extremely excellent method for curing and finishing protecting an alkaline inorganic cured body, which is capable of simultaneously forming a curing film and a finish coating film having excellent durability by painting.

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[Procedure amendment]

[Submission date] December 4, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction content]

Evaluation method (1) Finished appearance ..... visually observing the condition after air-drying curing for 14 days under the above conditions (2) Water resistance ..... To 2
After completely submerging in 0 ° C water for 3 days, after pulling up and drying for 3 days, visually judge the state of bleaching. (3) Accelerated weathering resistance ………… 500 hours with a sunshine weather meter Visually judge the condition after the test

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

(4) Dry-out resistance ... (B) described above
In 3 days, after the mold was removed and painted, the weight of the sample was measured, and then the sample was air-cured for 23 days (that is, the weight was again measured at the age of 28 days). (5) Neutralization resistance ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
In addition, at 30 ° C. and in an atmosphere of 60% RH, the specimens were allowed to stand for 3 months, then each specimen was broken, and the cross-section was coated with the phenolphthalein solution to obtain the surface of the layer that does not develop color. Was measured (displayed as an average value at three points, respectively).

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

[0044]

[Table 1]

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

[0045]

[Table 2]

Claims (5)

[Claims] 1. An aqueous resin dispersion (A) as an essential component.
And an alkali thickening polymer (B), if necessary,
Furthermore, a method for curing and curing an alkaline inorganic cured material, which comprises coating an aqueous alkaline thickened coating composition also containing a pigment on the surface of the alkaline inorganic cured material. 2. An aqueous resin dispersion (A) as an essential component.
And an alkali thickening polymer (B), if necessary,
Furthermore, an aqueous alkaline thickening type coating composition also containing a pigment is coated on the surface of the alkaline inorganic cured body under curing before the composition for the alkaline inorganic cured body is condensed. And a method for curing and curing an alkaline inorganic cured body. 3. The curing finishing method according to claim 1, wherein the aqueous resin dispersion (A) is an emulsion polymer. 4. The curing finishing method according to claim 1, wherein the alkali thickening polymer (B) is an emulsion polymer. 5. The above-mentioned respective ratios of the aqueous resin dispersion (A) and the alkali thickening polymer (B) are:
(A): (B) solid content weight ratio, 90:10 to 9
The curing finishing method according to claim 1 or 2, which is in the range of 9.9: 0.1.