JP2022069747A - Hydraulic polymer cement composition and method for application thereof - Google Patents

Abstract

To provide a hydraulic polymer cement composition that is low in the contraction stress of a coating layer, prevents the coating layer from being peeled off, has high compression strength and shock resistance and thermal shock resistance, resists color change due to ultraviolet rays, prevents the surface of the coating layer from being tacky with time, and is also excellent in beauty, and a method for application thereof.SOLUTION: A hydraulic polymer cement composition contains a water-dispersion polyol, a polyisocyanate, an organic metal catalyst, hydraulic cement and aggregate. The water-dispersion polyol includes water, a castor oil-based trifunctional polyol and a tetrafunctional polyol having a bisphenol A skeleton, with a hydroxyl equivalent of 500-800, making up 4-10 pts.wt. of the whole composition 100 pts.wt. The polyisocyanate is composed of an aliphatic isocyanurate and makes up 5-15 pts.wt. of the whole composition 100 pts.wt.SELECTED DRAWING: None

Description

The present invention comprises at least a water-dispersed polyol, a polyisocyanate, an organic metal catalyst, a hydraulic cement, and an aggregate, and is a mortar to be applied to the surface of concrete under the floor to a thickness of 2.5 mm or more and less than 10.0 mm. The present invention relates to a hydraulic polymer cement composition in the form and a method thereof.

Conventionally, a mortar-like hydraulic polymer cement composition to be applied to the surface of concrete underfloor has an extremely large shrinkage force of the coating film, and is easily peeled off when simply applied to the surface of concrete under floor. As shown in claim 3, first, the fragile layer of the floor base concrete is removed, and a groove portion having a depth of 7 to 13 mm and a width of 7 to 13 mm is provided at the edge of the floor base concrete, and the groove portion facing the floor base concrete is provided. When the distance from the groove is more than 12 m, joints with a depth of 7 to 13 mm and a width of 7 to 13 mm are provided every 12 m from the groove, and the inside of the groove and the joint are filled with the composition under the floor. It was necessary to apply it directly on the ground concrete to a thickness of 6 to 9 mm.

In order to solve this problem, in Patent Document 2, a specific diluent is added to the composition to reduce the shrinkage force of the coating film, and the width of the concrete under the floor is 7 to 13 mm in depth. However, there has been proposed a composition that can be constructed without providing a groove or a joint having a thickness of 7 to 13 mm.

Further, as a mortar-like hydraulic polymer cement composition containing a water-dispersed polyol, polyisocyanate, cement, aggregate and water, which is applied to the surface of a concrete base to a thickness of 3 mm to 5 mm, the water of Patent Document 3 Hard polymer cement compositions have been proposed.

Further, Patent Document 4 proposes a paste-like hydraulic polymer cement composition to be applied to the surface of concrete under the floor to a thickness of 0.2 mm or more and less than 4.0 mm, and a method for constructing the same.

Japanese Unexamined Patent Publication No. 2015-81325 Japanese Unexamined Patent Publication No. 2016-17024 Japanese Unexamined Patent Publication No. 2017-65942 Japanese Unexamined Patent Publication No. 2020-37508

However, in the composition described in Patent Document 2, even if the shrinkage force can be suppressed to a low level, as shown in the examples thereof, the polyisocyanate is expected to increase the coating strength of the crude MDI (4). , 4'-Diphenylmethane diisocyanate), its compressive strength remains at about 21 N / mm ² , and it has sufficient performance as a floor of a food factory, for example, where higher strength, thermal shock resistance, and impact resistance are required. There is a problem that it does not have.

Further, in the water-hard polymer cement composition of Patent Document 3, when crude MDI (4,4'-diphenylmethane diisocyanate, polymethylpolyphenylpolyisocyanate) is used as the polyisocyanate as described above as shown in the examples thereof. However, the compression strength thereof is shown to be 31.0 N / mm ² , but the composition has a high shrinkage rate of the coating film, and is used in the method for evaluating the thermal impact resistance of paragraph 0036 of Patent Document 3. As shown, it is necessary for the test piece to be provided with joints having a depth of 10 mm and a width of 10 mm 5 mm inside from the four sides of the wood end. When evaluated, there is a problem that it is easily peeled off due to the shrinkage force of the coating film.

Further, when polymethylpolyphenylpolyisocyanate is used as the polyisocyanate, the compositions of Patent Document 2 and Patent Document 3 are significantly yellowed by ultraviolet rays, and the color tone of the composition applied to the floor changes. Finally, there is a problem that it turns brown and spoils the aesthetics.

Further, the composition of Patent Document 4 has a problem that fine cracks may occur on the surface of the coating film over time.

The problem to be solved by the present invention is a mortar-like water-hard polymer cement composition to be applied to the concrete surface of the floor base concrete to a thickness of 2.5 mm to 9.0 mm, but the shrinkage stress of the coating film is small, and the floor base is directly applied. Even if it is applied to the concrete surface, the coating film does not peel off. Therefore, when applying it on the floor base concrete, a groove with a depth of 7 to 13 mm and a width of 7 to 13 mm is formed at the edge of the floor base concrete. It is not necessary to provide a joint portion with a depth of 7 to 13 mm and a width of 7 to 13 mm every 12 m or less from the groove portion, and despite the small shrinkage stress of the coating film, high compressive strength, impact resistance and impact resistance A water-hard polymer cement composition having heat-impact resistance, the color tone does not change due to ultraviolet rays, and fine cracks do not occur on the surface of the coating film over time, and the construction method thereof is excellent in aesthetics. To provide.

In order to solve the above problems, the invention according to claim 1 is a water-hard polymer cement composition comprising a water-dispersed polyol, a polyisocyanate, an organic metal catalyst, glycerin, a water-hard cement, and an aggregate. And
The water-dispersed polyol contains water, a castor oil-based trifunctional polyol, and a tetrafunctional polyol having a bisphenol A skeleton, and has a hydroxyl group equivalent of 500 to 800, which is 4 to 10 parts by weight in 100 parts by weight of the entire composition.
The castor oil-based trifunctional polyol is more than 30 parts by weight and 50 parts by weight or less in 100 parts by weight of the water-dispersed polyol.
Glycerin is more than 0 parts by weight and 5 parts by weight or less in 100 parts by weight of the entire composition.
The polyisocyanate is composed of an aliphatic isocyanurate, and the polyisocyanate is 5 to 15 parts by weight in 100 parts by weight of the whole composition.
The hydraulic cement is 5 to 15 parts by weight out of 100 parts by weight of the entire composition.
The aggregate is 70-85 parts by weight out of 100 parts by weight of the entire composition.
Provided is a hydraulic polymer cement composition characterized by the above.

The invention according to claim 2 provides the hydraulic polymer cement composition according to claim 1 or 2, wherein the polyisocyanate is hexamethylene disosocyanurate.

The invention according to claim 3 is characterized in that the hydraulic polymer cement composition according to claim 1 or 2 is applied to the surface of concrete under the floor to a thickness of 2.5 to 10 mm. Provided is a method for constructing a rigid polymer cement composition.

The hydraulic polymer cement composition of the present invention has the effect of being able to be applied to the surface of the concrete under the floor to a thickness of 2.5 mm to 9 mm, and the shrinkage stress, which is the stress generated inside the cured coating film, is extremely high. It has the effect of being small. Therefore, even if the thickness is applied directly onto the concrete under the floor, there is an effect that the coating film after curing does not peel off.

Further, since the hydraulic polymer cement composition of the present invention has an extremely small shrinkage stress of the coating film as described above, the depth is within 12 m at the edge of the floor base concrete or the surface of the floor base concrete as in the conventional case. There is an effect that it is not necessary to provide a joint portion having a width of 7 to 13 mm and a width of 7 to 13 mm. Therefore, there is an effect that it can be easily and quickly applied to the surface of the concrete under the floor, and as a result, there is an effect that the cost is low.

Further, the hydraulic polymer cement composition of the present invention has an effect of having sufficient compressive strength, impact resistance and heat impact resistance even though the shrinkage stress which is the stress generated inside the coating film is extremely small. .. Of course, there is an effect that the hydraulic polymer cement composition of the present invention can be used even when the special property of thermal shock resistance is not required.

Further, since the polyisocyanate of the water-hard polymer cement composition of the present invention is composed of an aliphatic isocyanurate, the cured coating film does not turn yellow due to sunlight, ultraviolet rays, etc., and has an effect of being excellent in aesthetics. ..

Further, the hydraulic polymer cement composition of the present invention has good coating workability even when coated to a thickness of 2.5 to 5 mm, which is slightly thinner than the conventional one, and is performed on the floor of a food factory. Even if it is washed with hot water like this, it has the effect of having sufficient thermal shock resistance so that peeling and cracking do not occur.

Further, the hydraulic polymer cement composition of the present invention has an effect that fine cracks are hardly generated on the surface of the coating film with time after being applied to the surface of the concrete under the floor and cured.

FIG. 3 is a coating film peeling model diagram showing a state in which a coating film of a flooring material applied to the surface of the underlying concrete is peeled off at an angle of 5 degrees due to a coating film shrinkage force T, as viewed from the cross-sectional direction of the coating film. It is a figure which showed the relationship between the surface tensile strength of the base concrete with a water-cement ratio of 60%, and the latency residual ratio.

Hereinafter, the present invention will be described in detail.

The water-hard polymer cement composition of the present invention contains, for the water-hard polymer cement composition of claim 1, a water-dispersed polyol, a polyisocyanate, an organic metal catalyst, a glycerin, a water-hard cement, and an aggregate. , The water-dispersed polyol contains water, a persimmon oil-based trifunctional polyol, and a tetrafunctional polyol having a bisphenol A skeleton, and has a hydroxyl group equivalent of 500 to 800, and the entire composition is 100. It is 4 to 10 parts by weight in parts by weight, the castor oil-based trifunctional polyol is more than 30 parts by weight and 50 parts by weight or less in 100 parts by weight of the water-dispersed polyol, and glycerin is 0 weight by weight in 100 parts by weight of the entire composition. More than 5 parts by weight, polyisocyanate is composed of aliphatic isocyanurate, polyisocyanate is 5 to 15 parts by weight in 100 parts by weight of the whole composition, and water-hard cement is in 100 parts by weight of the whole composition. A water-hard polymer cement composition comprising 5 to 15 parts by weight and the aggregate being 70 to 85 parts by weight of 100 parts by weight of the entire composition, in addition to these as required. Additives such as pigments, dispersants, defoaming agents, and diluents can be blended.

The water-dispersed polyol used in the present invention includes water, a castor oil-based trifunctional polyol, and a tetrafunctional polyol having a bisphenol A skeleton, and the castor oil-based trifunctional polyol is a castor oil and a derivative thereof, for example, a castor oil fatty acid. It is a diglyceride, a monoglyceride or a mixture thereof, and is a polyol having 3 hydroxyl groups. The hydroxyl group equivalent of the castor oil-modified trifunctional polyol used in the present invention is preferably 250 to 450, and if it is less than 250, the shrinkage stress of the cured product becomes large and the coating film peels off from the underlying concrete, or the curing becomes faster. The property becomes poor, and if it exceeds 450, the strength after curing becomes insufficient as a water-hard polymer cement composition. The content of the castor oil-based trifunctional polyol in the water-dispersed polyol is preferably more than 30 parts by weight and 50 parts by weight or less in 100 parts by weight of the water-dispersed polyol, and the compression strength may be insufficient if the content is 30 parts by weight or less. If it exceeds the weight part, the thermal shock resistance may be insufficient.

The tetrafunctional polyol having a bisphenol A skeleton is an epoxy ring-opening polyol obtained by reacting a polyepoxy compound having a bisphenol A skeleton with an active hydrogen compound, and the hydroxyl equivalent is preferably 250 to 450. If the hydroxyl group equivalent is less than 250, the shrinkage stress of the cured product becomes large and the coating film peels off from the underlying concrete, or the curing becomes faster and the workability becomes poor. Insufficient strength. Further, the content of the tetrafunctional polyol having a bisphenol A skeleton in the water-dispersed polyol is preferably more than 2 parts by weight and 15 parts by weight or less in 100 parts by weight of the water-dispersed polyol, and the compression strength may be insufficient if it is 2 parts by weight or less. If it exceeds 15 parts by weight, the thermal shock resistance may be insufficient.

The hydroxyl equivalent of the water-dispersed polyol used in the present invention is preferably 500 to 800, and if it is less than 500, the curing as a hydraulic polymer cement composition becomes faster and workability becomes poor, and if it exceeds 800, the hydraulic polymer cement composition As a result, the strength after curing becomes insufficient. The blending amount of the water-dispersed polyol is preferably 4 to 10 parts by weight in 100 parts by weight of the entire composition, and if it is less than 4 parts by weight, the strength of the cured product of the composition decreases, and if it exceeds 10 parts by weight, the composition is coated with a gold trowel. Workability when attaching is reduced.

The blending amount of glycerin used in the present invention is more than 0 parts by weight and 5 parts by weight or less in 100 parts by weight of the entire composition, and the compressive strength is insufficient due to the blending of the tetrafunctional polyol having the bisphenol A skeleton. Add an amount that restores impact resistance and heat impact resistance.

The polyisocyanate used in the present invention is obtained from an aliphatic polyisocyanate and is composed of an aliphatic isocyanurate having an isocyanurate structure. Specifically, hexamethylene diisocyanurate obtained by cyclizing and trimerizing 1,6 hexamethylene diisocyanate is preferable because it has excellent weather resistance and improves the hardness of the coating film. In order to cyclize and trigerate 1,6 hexamethylene diisocyanate, the method described in JP-A No. 01-33115 can be used, and the polyisocyanate used in the present invention includes other aliphatic diisocyanates and fats. A cyclic diisocyanate or the like, or these prepolymers can be used in combination, and a polyisocyanate content of 99% by weight or more is used.

Further, as the polyisocyanate used in the present invention, one having an NCO% of 15 to 25% by weight can be used, and a polyisocyanate having an NCO% of 20 to 25% by weight is more preferable. If it is less than 15% by weight, the strength of the coating film may be insufficient, and if it is more than 25% by weight, the amount of polyisocyanate having an isocyanurate structure is reduced, and conversely, the amount of polyisocyanate that is not quantified, for example, diisocyanate is polyisocyanate. Since the number increases, the strength of the coating film is also insufficient.

Further, the viscosity of the polyisocyanate used in the present invention is preferably 500 to 3500 mPa · s / 25 ° C., and if it is less than 500 mPa · s, the strength of the coating film may be insufficient, and if it exceeds 3500 mPa · s, the surface of the underlying concrete Workability when applying to the concrete may decrease.

Further, the polyisocyanate used in the present invention is 5 to 15 parts by weight in 100 parts by weight of the entire composition, and if it is less than 5 parts by weight, the strength of the coating film may be insufficient, and if it exceeds 15 parts by weight, the curing time may be insufficient. It may become shorter and workability may be insufficient.

The organic metal-based catalyst used in the present invention is formulated to accelerate the curing of the present composition, for example, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dibutyltin diacetylacetonate, dibutyl. Organic metal catalysts such as tin dilaurate, dibutyltin dichloride, lead octylate, lead naphthenate, and bismuth octylate can be used. Among these curing catalysts, organotin compounds are more preferable. Of these curing catalysts, dibutyltin diacetylacetonate, dibutyltin diacetate, dibutyltin dilaurate, and dibutyltin dichloride are more preferable from the viewpoint of catalytic effect. The blending amount of the organometallic catalyst is 0.001 to 0.01 parts by weight in 100 parts by weight of the entire composition, and if it is less than 0.001 parts by weight, the strength of the coating film may be insufficient, and it is 0. If it exceeds .01 parts by weight, curing will be faster and coating workability with gold iron etc. may be poor.

As the hydraulic cement used in the present invention, it is preferable to mainly use white Portland cement so that a specific color tone can be imparted, and in addition, ordinary Portland cement, alumina cement, blast furnace cement, early-strength Portland cement and the like are used in combination. Can be done. The blending amount of the hydraulic cement is preferably 5 to 15 parts by weight in 100 parts by weight of the entire composition, and the strength of the coating film decreases when the amount is less than 5 parts by weight. The application workability when applying to the concrete surface is reduced.

The aggregate used in the water-hard polymer cement composition of the present invention includes Gaishi powder having a particle size of 1.0 to 3.0 mm, silica sand having a particle size of 0.6 to 2.36 mm, and a particle size of 0. .21 to 1.18 mm silica sand, 0.15 to 0.85 mm particle diameter silica sand, 0.05 to 0.6 mm particle diameter silica sand, and 0.04 to 0.3 mm particle diameter silica sand. Are used in combination. Insulator powder is crushed NGK that has been damaged or discarded at a NGK production factory, and has the effect of imparting the strength, wear resistance, heat resistance, etc. of ceramics to the floor. If the particle size is less than 1.0 mm, the workability of coating on the concrete under the floor becomes poor, and if it exceeds 3.0 mm, the dispersibility in the composition and the unevenness of the coating film surface after curing become too large.

The silica sand with a particle diameter of 0.6 to 2.36 mm is No. 3 silica sand, the silica sand with a particle diameter of 0.21 to 1.18 mm is silica sand No. 4, and the silica sand with a particle diameter of 0.15 to 0.85 mm is 5. No. 6 is applicable to silica sand having a particle diameter of 0.05 to 0.6 mm, and is applicable to silica sand having a particle diameter of 0.04 to 0.3 mm. For example, the combined ratio of Gaishi powder with a particle size of 1.0 to 3.0 mm, silica sand with a particle size of 0.21 to 1.18 mm, and silica sand with a particle size of 0.04 to 0.3 mm is 8 to 8 by weight. 12: 60 to 100: 0.5 to 2.0 is preferable from the viewpoint of coating workability, strength development, impact resistance, etc. when applying about 5 to 9 mm to the floor base concrete. Further, for example, the combined ratio of Gaishi powder having a particle diameter of 1.0 to 3.0 mm, silica sand having a particle diameter of 0.21 to 1.18 mm, and silica sand having a particle diameter of 0.05 to 0.6 mm is 0 by weight. 8.8 to 1.2: 2.0 to 4.0: 0.3 to 1.0, such as coating workability, strength development, impact resistance, etc. when applying about 2.5 to 5 mm to the floor base concrete. Preferred from the point of view.

The number of parts to be blended with the aggregate is 70 to 85 parts by weight in 100 parts by weight of the entire composition, and if it is less than 70 parts by weight, the smoothness of the coating film may be poor, and if it exceeds 85 parts by weight, the impact resistance is reduced. Sex may be reduced.

In addition to the above, it is preferable to add slaked lime to the water-individual polymer cement composition of the present invention. The slaked lime absorbs carbon dioxide gas generated by the urea reaction between polyisocyanate and water, and the carbon dioxide gas generated until the composition is applied on the floor concrete and hardened concentrates on a specific part and presses the coating film. It has the effect of suppressing the raising and causing swelling.

The hydraulic polymer cement composition of the present invention is applied to the surface of the underlying concrete to a thickness of 2.5 to 9 mm using a gold trowel, a wooden trowel, or the like. Preferably, the composition is first distributed on the surface of the base concrete with a wooden trowel, and then evenly distributed to the surface of the base concrete to be constructed so as to have a predetermined thickness, and the base concrete is firmly pressed with a trowel as a finish. By applying it so that it is integrated with the concrete, the cured coating film has no defects, and the coated floor can be made to have an excellent appearance.

Hereinafter, a specific description will be given with reference to Examples and Comparative Examples.

<Examples and comparative examples>
As an aqueous dispersion polyol, 35 to 40 parts by weight of a castor oil-modified trifunctional polyol having a hydroxyl group equivalent of 350, 5 to 10 parts by weight of a tetrafunctional polyol having a bisphenol A skeleton having a hydroxyl group equivalent of 360, and a sulfonic acid as a diluent. 20 to 25 parts by weight of an ester compound (Mezamole; trade name, manufactured by Bayer) and 30 parts by weight of water (ion-exchanged water) are included to make 100 parts by weight as a whole, and an aqueous dispersion polyol A having a hydroxyl group equivalent of 500 to 800. , A water-dispersed polyol B (water content: 25 to 30% by weight) consisting of a persimmon oil-based trifunctional polyol having a hydroxyl group equivalent of 280 to 560, and a persimmon oil-based bifunctional polyol with respect to 100 parts by weight of the persimmon oil-based trifunctional polyol. Water-dispersed polyol C (water content: 25 to 30% by weight) containing 25 to 33 parts by weight of the polyol and having a hydroxyl group equivalent of 200 to 250 as a whole, and 100 parts by weight of a persimmon oil-based trifunctional polyol. A water-dispersed polyol D (water content: 25 to 30% by weight) containing 14 to 20 parts by weight of a bifunctional polyol and having a hydroxyl group equivalent of 200 to 500 as a whole is used, and hexamethylene diisocyanurate (hexamethylene diisocyanurate) is used as a polyisocyanate. Polyisocyanate A having a viscosity of 2500 mPa · s / 25 ° C., NCO%: 20% by weight, polyisocyanate content of 99% by weight or more) and polyisocyanate B (NCO% by weight: 31.0) which is a 4,4′-diphenylmethane diisocyanate. (Weight%) is used, Neostan U220H (dibutyltin diacetylacetonate) is used as an organic metal-based catalyst, and selben (trade name, Co., Ltd.) having a particle diameter of 1.0 to 3.0 mm as an aggregate powder is used as an aggregate. (Made by Okumura Serum) and silica sand with a particle diameter of 0.21 to 1.18 mm: Tohoku silica sand No. 4 (trade name, manufactured by Tohoku silica sand Co., Ltd.) and silica sand with a particle diameter of 0.05 to 0.6 mm: Tohoku silica sand No. 6. (Product name, manufactured by Tohoku Polyol Co., Ltd.) and silica sand with a particle diameter of 0.04 to 0.3 mm: Tohoku Polyol No. 7 (trade name, manufactured by Tohoku Polyol Co., Ltd.) is used as a water-hardening cement (white Portoland cement). (Manufactured by Pacific Cement Co., Ltd.) was used to prepare the water-hard polymer cement compositions of Examples and Comparative Examples according to the formulations shown in Table 1. In the following evaluation, Example 1 and Comparative Examples 1 to 3, Comparative Example 7 and Comparative Example 9 were evaluated by finishing the coating film thickness to 7 mm, and Example 2 and Comparative Examples 4 to 4 were evaluated. 6. Comparative Example 8 and Comparative Example 10 were evaluated by finishing the coating film thickness to 3 mm.

<Evaluation items and evaluation methods>

<Film film finish>
The hydraulic polymers of Examples and Comparative Examples were applied to the surface of a dry concrete flat plate (5% or less in a Ket Moisture Meter HI-520 concrete range) of JIS A5371 at 23 ° C. of 300 mm × 300 mm × thickness 60 mm with a gold iron. The cement composition was applied to a predetermined thickness and finished, and the surface condition of the coating film was visually observed. The case of a smooth finish was evaluated as ◯, and the case of an uneven finish was evaluated as x.

<Impact resistance>
The hydraulic polymers of Examples and Comparative Examples were applied to the surface of a dry concrete flat plate (5% or less in a Ket Moisture Meter HI-520 concrete range) of JIS A5371 300 mm × 300 mm × thickness 60 mm at 23 ° C. with a gold trowel. Finish by applying the cement composition to a predetermined thickness. After curing for 7 days, a steel ball with a height of 1 m to 1 kg was dropped 60 times in the center, and the coating film with no abnormalities such as cracks and peeling was marked with ○, and those with abnormalities such as cracking and peeling were marked with ×. evaluated.

<Compressive strength>
The hydraulic polymer cement compositions of Examples and Comparative Examples were cured at 23 ° C., and the cured product after 7-day curing was measured for compressive strength (N / mm ² ) according to the provisions of JIS K6911. The size of the test piece was 13 mm × 13 mm × 25 mm. When the compressive strength was more than 22 N / mm ² , it was evaluated as ◯ as having sufficient strength, and when it was less than this, it was evaluated as ×.

<Heat-resistant impact resistance and fine crack resistance>
JISA5371 300 mm x 300 mm x 60 mm thick dry concrete flat plate (5% or less in the Ket Moisture Meter HI-520 concrete range) was cut into quarters to make a 150 mm x 150 mm x 60 mm thick test plate. The surface of the test plate was sufficiently roughened with sandpaper # 80 to remove the fragile layer, and the hydraulic polymer cement compositions of Examples and Comparative Examples were uniformly mixed. The hydraulic polymer cement compositions of Comparative Example 3, Comparative Example 7 and Comparative Example 9 have a thickness of 7 mm, and the hydraulic polymers of Example 2 and Comparative Examples 4 to 6, Comparative Example 8 and Comparative Example 10 are used. The cement composition is applied to a thickness of 3 mm and cured for 7 days. After that, hot water at 95 ° C. was allowed to flow down to the center of the test piece for 5 minutes, and then cold water at 20 ° C. was allowed to flow down for 10 minutes. Is evaluated as thermal shock resistance 〇 for those with no abnormalities such as peeling and floating in the coating film after repeating 4000 cycles, and with the same × for those with abnormalities, and withstands those with fine cracks on the coating film surface. Fine crack property ×, those without fine cracks were evaluated as 〇

<Adhesiveness>
The hydraulic polymers of Examples and Comparative Examples were applied to the surface of a dry concrete flat plate (5% or less in a Ket Moisture Meter HI-520 concrete range) of JIS A5371 300 mm × 300 mm × thickness 60 mm at 23 ° C. with a gold trowel. Finish by applying the cement composition to a predetermined thickness. After curing for 7 days, the adhesion strength (N / mm ² ) between the hydraulic polymer cement composition of 40 × 40 mm portion and the concrete flat plate was measured by a Kenken type adhesive strength tester. As for the fracture state, 100% cohesive fracture of the base concrete was evaluated as ◯, and the others were evaluated as ×.

<Peeling resistance>
For the water-hard polymer cement compositions of Example 1 and Comparative Examples 1 to 3, Comparative Example 7 and Comparative Example 9, the cured product was molded into a strip having a length of 160 mm, a width of 10 mm and a thickness of 7 mm, and Example 2 was formed. For the hydraulic polymer cement compositions of Comparative Examples 4 to 6, Comparative Example 8 and Comparative Example 10, the cured product was molded into strips having a length of 160 mm, a width of 10 mm and a thickness of 3 mm, respectively, at 23 ° C. for 7 days. After curing, the amount of shrinkage strain L (mm) when heat-cured at 50 ° C. for 14 days is measured. Next, the tensile modulus E (N / mm ² ) is measured by pulling in the longitudinal direction at a speed of 1 mm / min. From the amount of shrinkage strain L (mm) and the length L ₀ (mm) of the test piece after curing at 23 ° C for 7 days, the shrinkage stress (N / mm ² ) per unit cross-sectional area of the coating film is calculated by the following equation (1). Further, Example 1 and Comparative Examples 1 to 3, Comparative Example 7 and Comparative Example 9 have a coating thickness of 7 mm, and Example 2 and Comparative Examples 4 to 6, Comparative Example 8 and Comparative Example 10 have a coating thickness of 7 mm. Calculated the coating film shrinkage force T (N / mm) per unit width of the coating film by multiplying the coating film thickness by 3 mm.
Shrinkage stress (N / mm ² ) = E (L / L ₀ ) ... (1)
Here, it is considered that the coating film shrinkage force T (N / mm) empirically acts in the direction of peeling the coating film. Therefore, the coating film shrinkage force at this time is shown in FIG. 1 empirically and empirically. It is considered that the coating film is peeled off by pulling the coating film at a shallow angle of about 5 degrees, and the vertical force Tv (N / mm) per unit width (mm) of the coating film is calculated by the following equation (2). ).
Vertical force Tv (N / mm) = sin5 ° × T ... (2)
This vertical force Tv (N / mm) per unit width (1 mm) acts on 1 mm ² of the substrate to which the coating film is adhered experimentally and empirically because the coating film thickness is as thick as 7 mm or 3 mm. Therefore, the force in the vertical direction acts to pull the coating film in the direction perpendicular to the unit surface area (1 mm ² ) of the underlying concrete, and this is defined as the normal stress Tv ₂ (N / mm ² ).

On top of that, first, Fig. 2 showing the relationship between the surface tensile strength of the base concrete and the latency residual rate at a water / cement ratio of 60% (Effect of the base concrete on the occurrence of blisters on the coated floor, structure of the Japan Society for Architecture) See Proceedings, No. 493, 1-7, March 1997, Table 1 and Fig. 12 (air-drying state). The vertical stress Tv ₂ (N / mm ² ) is compared, and even if 100% of the latency remains in the underlying concrete, the surface tensile strength of the underlying concrete is 0.7 N / mm ² . (Usually, the base concrete from which all the latency has been removed is the base concrete specification suitable for the construction of the flooring material), and the vertical stress Tv ₂ (N / mm ² ) is higher than the 0.7 N / mm ² . If it is small, it is considered that the coating film does not peel off from the underlying concrete only by the action of the shrinkage force of the coating film, and it was evaluated as ⊚. When the normal stress Tv ₂ (N / mm ² ) is larger than the surface tensile strength 0.7 N / mm ² (latency residual rate 100%) of the underlying concrete, the coating film is formed by the action of only the shrinkage force of the coating film. It was evaluated as x because it may break the surface of the concrete and peel off.

In addition, the 2012 edition of the Painted Floor Handbook (issued on March 1, 2012, supervised by Hiroshi Yokoyama, edited by the Japan Painted Floor Industry Association, published and sold by Kobunsha) includes a new concrete base for the painted floor. -Since the surface (tensile) strength as one of the qualities of the mortar and the repair base is specified as 1.5 N / mm ² , this 1.5 N / mm ² and the normal stress Tv ₂ (N / mm ² ) are specified. ), And if the normal stress Tv ₂ (N / mm ² ) is smaller than the 1.5 N / mm ² , the coating film may peel off from the underlying concrete only by the action of the shrinkage force of the coating film. I thought it wasn't there and evaluated it as ○. When the normal stress Tv ₂ (N / mm ² ) is larger than the surface (tensile) strength of 1.5 N / mm ² , the coating film destroys the surface of the underlying concrete and peels off due to the action of only the shrinkage force of the coating film. It was evaluated as x because there are cases.

Of the above two judgments, if at least the judgment at the specified value of 1.5 N / mm ² in the coating floor handbook is ○, it is judged that the peeling resistance is good, and if both are ×, the conventional method. If a groove with a depth of 7 to 13 mm and a width of 7 to 13 mm is provided at the edge of the floor base concrete and the distance between the opposing grooves is more than 12 m, the depth is within 12 m from the groove. It is determined that a joint portion having a width of 7 to 13 mm and a width of 7 to 13 mm must be provided, and the composition must be applied to the concrete under the floor while filling the inside of the groove portion and the joint portion with the composition.

<Yellow denaturation resistance>
For the water-hard polymer cement compositions of Example 1 and Comparative Examples 1 to 3, Comparative Example 7 and Comparative Example 9, a cured coating film having a thickness of 7 mm was applied, and Example 2 and Comparative Examples 4 to 6 were compared. For the water-hard polymer cement compositions of Example 8 and Comparative Example 10, a cured coating film having a thickness of 3 mm was irradiated with black light (germicidal lamp, peak wavelength 256 nm, 31 μW / cm ² ) for 200 hours from a height of 50 cm. The color difference (ΔE) before and after irradiation was measured. A ΔE of 1.0 or less was evaluated as ◯, and a ΔE of more than 1.0 was evaluated as ×.

<Evaluation result>
The evaluation results are shown in Table 2.

Claims (3)

A hydraulic polymer cement composition comprising a water-dispersed polyol, a polyisocyanate, an organic metal catalyst, glycerin, a hydraulic cement, and an aggregate.
The water-dispersed polyol contains water, a castor oil-based trifunctional polyol, and a tetrafunctional polyol having a bisphenol A skeleton, and has a hydroxyl group equivalent of 500 to 800, which is 4 to 10 parts by weight in 100 parts by weight of the entire composition.
The castor oil-based trifunctional polyol is more than 30 parts by weight and 50 parts by weight or less in 100 parts by weight of the water-dispersed polyol.
Glycerin is more than 0 parts by weight and 5 parts by weight or less in 100 parts by weight of the entire composition.
The polyisocyanate is composed of an aliphatic isocyanurate, and the polyisocyanate is 5 to 15 parts by weight in 100 parts by weight of the whole composition.
The hydraulic cement is 5 to 15 parts by weight out of 100 parts by weight of the entire composition.
The aggregate is 70-85 parts by weight out of 100 parts by weight of the entire composition.
A hydraulic polymer cement composition characterized by that. The hydraulic polymer cement composition according to claim 1, wherein the polyisocyanate is hexamethylene diisocyanurate. A method for constructing a hydraulic polymer cement composition, which comprises applying the hydraulic polymer cement composition according to claim 1 or 2 to a surface of concrete under the floor to a thickness of 2.5 to 10 mm.

Images