JP7267147B2 - Hydraulic polymer cement composition and its application method - Google Patents

Description

The present invention contains a water-dispersed polyol, a polyisocyanate, an organometallic catalyst, glycerin, a hydraulic cement, and an aggregate. The present invention relates to a hydraulic polymer cement composition and its application method.

Conventional pasty polyurethane-based cement composition containing water-dispersed polyol, polyisocyanate, cement, and filler, which is applied to the surface of subfloor concrete to a thickness of 0.2 mm or more and less than 2.5 mm, and the concrete floor thereof A construction method has been proposed (Patent Document 1, Patent Document 2).

The polyurethane-based cement composition described in Patent Document 1 contains a water-dispersed polyol, a polyisocyanate, cement, and a filler, and is a pasty polyurethane that is applied to a thickness of 0.2 mm or more and less than 2.5 mm. The water-dispersible cement composition comprises a castor oil-modified bifunctional polyol, a castor oil-modified trifunctional polyol, bis(2-butoxyethyl) phthalate, an emulsifier, and water, and the hydroxyl group equivalent of the water-dispersed polyol is 200 to 250, the JIS K 5600-4-7 60 degree specular gloss of the cured coating film having a thickness of 1.5 mm or more and less than 2.5 mm is 85 or more, and the JIS K 7215 type D durometer hardness is 80 or more. A polyurethane-based cement composition characterized by:

Further, the polyurethane-based cement composition described in Patent Document 2 contains a water-dispersed polyol, a polyisocyanate, a diluent, cement and a filler, and is applied to a thickness of 0.2 mm or more and less than 2.5 mm. A paste-like polyurethane-based cement composition, wherein the water-dispersed polyol comprises a castor oil-modified bifunctional polyol, a castor oil-modified trifunctional polyol, bis(2-butoxyethyl) phthalate, an emulsifier, and water, and the diluent is The water-dispersed polyol contains a benzoic acid glycol ester and has a hydroxyl equivalent of 200 to 250. The polyisocyanate has a viscosity of 250 to 400 mPa·s/23° C., an NCO equivalent of 130 to 140, and a thickness of 1.5 mm or more.2. JIS K 5600-4-7 60 degree specular gloss of less than 5 mm 5 ° C. cured coating film is 85 or more, JIS K 7215 type D durometer hardness of 23 ° C. cured coating film with a thickness of 1.5 mm or more and less than 2.5 mm The polyurethane-based cement composition is characterized by having a shavings ratio of 80 or more.

JP 2016-196399 A JP 2017-154929 A JP 2015-81325 A

However, the polyurethane-based cement composition described in Patent Document 1 or Patent Document 2, even if it contains a diluent (bis(2-butoxyethyl) phthalate), has a coating film compressive strength of 40 N/mm or more. Despite the fact that the coating thickness is relatively thin, such as being high and coating the surface of the underlying concrete to a thickness of 0.2 mm or more and less than 2.5 mm, the hydration of cement and the reaction of polyisocyanate with polyols and moisture There is a problem that the amount of shrinkage of the coating film caused by this is large, and therefore the shrinkage stress as the internal stress generated inside the coating film is extremely large.

When the polyurethane-based cement composition described in Patent Document 1 or Patent Document 2, which has such a large coating film shrinkage stress, is simply applied to the underlying concrete surface, the coating film may peel off due to the shrinkage stress. There is a problem, and in order to solve the problem of peeling of the coating film, similar to the invention described in claim 3 of Patent Document 3 (the composition described in Patent Document 3 has a coating thickness of 6 Since it is applied to a thickness of up to 9 mm, 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 subfloor concrete, and the distance between the opposing grooves is more than 12 m, then A joint portion having a depth of 7 to 13 mm and a width of 7 to 13 mm is provided within 12 m from the groove portion, and the composition described in Patent Document 3 is filled in the groove portion and the joint portion, and is applied to the subfloor concrete. However, since the coating thickness during construction of the composition of the present invention is 0.2 mm or more and less than 4.0 mm, the shape of the groove may be small empirically). If a groove with a depth of 3 to 7 mm and a width of 3 to 7 mm is provided in the groove, and the distance between the opposing grooves is more than 12 m, then every 12 m from the groove has a depth of 3 to 7 mm and a width of 3 to 7 mm. There is a problem that it is necessary to apply the polyurethane cement composition to the subfloor concrete while providing a joint part and filling the groove part and the joint part with the polyurethane cement composition. However, there is a problem that the cost is high as a result.

Further, the polyurethane-based cement composition described in Patent Document 1 or Patent Document 2, when polymethylpolyphenyl polyisocyanate is used as the polyisocyanate, is remarkably yellowed by ultraviolet rays, and the polyurethane-based cement applied to the floor There is a problem that the color tone of the composition changes and eventually becomes brown, impairing the aesthetic appearance.

The problem to be solved by the present invention is to provide a paste-like hydraulic polymer cement composition that is applied to the surface of the subfloor concrete to a thickness of 0.2 mm or more and less than 4.0 mm, while the shrinkage stress of the coating film is small, so that it can be applied directly under the floor. Even if it is applied to the ground concrete surface, the coating film does not peel off. Hydraulic polymer cement composition which does not need to provide a joint portion with a depth of 3 to 7 mm and a width of 3 to 7 mm within 12 m from the groove portion, and which is excellent in appearance without changing color tone due to ultraviolet rays, and its application It is to provide a method.

In order to solve the above problems, the invention according to claim 1 is a hydraulic polymer cement composition comprising a water-dispersed polyol, a polyisocyanate, an organometallic catalyst, glycerin, a hydraulic cement and an aggregate,
The water-dispersed polyol consists of water, a castor oil-based bifunctional polyol, and a castor oil-based trifunctional polyol, and has a hydroxyl equivalent of 200 to 600 and is 10 to 25 parts by weight in 100 parts by weight of the entire composition,
The castor oil-based bifunctional polyol is more than 0 parts by weight and 40 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 consists of an aliphatic isocyanurate, and the polyisocyanate is 20 to 35 parts by weight in 100 parts by weight of the total composition,
The organometallic catalyst is an organotin compound and is 0.005 to 0.05 parts by weight in 100 parts by weight of the entire composition,
Hydraulic cement is 10 to 30 parts by weight in 100 parts by weight of the entire composition,
Aggregate is 25 to 50 parts by weight in 100 parts by weight of the total composition,
Provided is a hydraulic polymer cement composition characterized by:

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

Further, according to the invention of claim 3, the hydraulic polymer cement composition of claim 1 or claim 2 is applied as a primer to the surface of underfloor concrete to a thickness of 0.2 mm or more and less than 1.5 mm and cured. After drying, the hydraulic polymer cement composition is further applied as a top coat to a thickness of 1.0 mm or more and less than 4.0 mm to provide a method for applying a hydraulic 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 subfloor concrete to a thickness of 0.2 mm or more and less than 4.0 mm, and the shrinkage, which is the stress generated inside the hardened coating film. There is an effect that the stress is extremely small. Therefore, there is an effect that even if the coating film is applied directly onto the floor subfloor concrete in a predetermined thickness, the cured coating film will not peel off.

In addition, since the hydraulic polymer cement composition of the present invention has extremely low shrinkage stress of the coating film as described above, it is possible to apply the coating film at the edge of the subfloor concrete and the surface of the subfloor concrete within 12 m of the depth in the conventional manner. There is an effect that it is not necessary to provide a joint portion having a width of 3 to 7 mm and a width of 3 to 7 mm. Therefore, there is an effect that it can be easily applied to the surface of the underfloor concrete in a short period of time, and as a result, there is an effect that the cost is low.

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

The method for applying the hydraulic polymer cement composition according to claim 3 of the present invention comprises uniformly applying the hydraulic polymer cement composition according to claim 1 or 2 to the surface of the underlying concrete in a predetermined thickness. There is an effect that the coating film after curing is excellent in appearance. In particular, the fine pores on the surface of the subfloor concrete (pores arising from the microstructure of the concrete) are filled with the hydraulic polymer cement composition of the undercoat, and when the topcoat is applied to the undercoat, the topcoat is applied directly to the concrete surface of the subfloor, it has the effect that pinholes do not occur in the coating film of the topcoat, and the coating film surface formed with the hydraulic polymer cement composition of the present invention is beautiful. There is an effect that it is excellent in

FIG. 2 is a paint film peeling model diagram showing a state in which a paint film of a floor coating material applied to a surface of a base concrete peels off at an angle of 5 degrees due to a paint film shrinkage force T, viewed from the paint film cross-sectional direction. FIG. 3 is a diagram showing the relationship between the surface tensile strength of a base concrete having a water-cement ratio of 60% and the residual laitance.

The present invention will be described in detail below.

The hydraulic polymer cement composition of the present invention comprises a water-dispersed polyol, a polyisocyanate, an organometallic catalyst, glycerin, a hydraulic cement and an aggregate, wherein the water-dispersed polyol is It consists of a castor oil-based bifunctional polyol and a castor oil-based trifunctional polyol, and has a hydroxyl equivalent of 200 to 600, which is 10 to 25 parts by weight in 100 parts by weight of the entire composition, and the castor oil-based bifunctional polyol is dispersed in water. More than 0 parts by weight and 40 parts by weight or less in 100 parts by weight of 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, polyisocyanate is an aliphatic isocyanurate, and polyisocyanate is 20 to 35 parts by weight in 100 parts by weight of the entire composition, the organometallic catalyst is an organic tin compound, and the amount is 0.005 to 0.05 parts by weight in 100 parts by weight of the entire composition, and the hydraulic A hydraulic polymer cement composition characterized by comprising 10 to 30 parts by weight of cement in 100 parts by weight of the entire composition, and 25 to 50 parts by weight of aggregate in 100 parts by weight of the entire composition. In addition to these, additives such as pigments, dispersants, antifoaming agents, diluents and the like can be blended as necessary.

The water-dispersible polyol used in the present invention comprises water, a castor oil-based bifunctional polyol, and a castor oil-based trifunctional polyol. Castor oil or a derivative thereof can be used as the castor oil-based bifunctional polyol. is a polyol having 2 hydroxyl groups, and the castor oil-based trifunctional polyol can similarly be castor oil or a derivative thereof, and is a polyol having 3 hydroxyl groups. The hydroxyl equivalent of the water-dispersible polyol used in the present invention is preferably 200 to 600. If it is less than 200, the hydraulic polymer cement composition will harden quickly and workability will be poor. As a result, the strength after curing becomes insufficient. The amount of the water-dispersed polyol is preferably 10 to 25 parts by weight in 100 parts by weight of the entire composition. Workability when applying with a brush or the like is reduced.

The castor oil-based bifunctional polyol in the water-dispersed polyol is more than 0 parts by weight and 40 parts by weight or less in 100 parts by weight of the water-dispersed polyol, and if it exceeds 40 parts by weight, the compressive strength and impact resistance become insufficient. . In the present invention, the decrease in compressive strength and the following impact resistance due to the inclusion of a castor oil-based bifunctional polyol is increased to more than 25 N/mm ² as a compressive strength by blending glycerin as a cross-linking agent, and is defined by the following evaluation items. It is characterized by being able to be used as a floor coating material that requires these as impact resistance. Therefore, when the castor oil-based bifunctional polyol is blended to such an extent that the compressive strength and impact resistance are impaired, glycerin is further blended, and this case is the present invention.

The 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 compression strength or impact resistance that is insufficient due to the addition of the castor oil-based bifunctional polyol Formulated with an amount that restores sexuality.

The polyisocyanate used in the present invention is obtained from an aliphatic polyisocyanate and consists of an aliphatic isocyanurate having an isocyanurate structure. Specifically, hexamethylene diisocyanurate obtained by cyclotrimerization of 1,6 hexamethylene diisocyanate is preferable because it has excellent weather resistance and improves the hardness of the coating film. In order to cyclotrimerize 1,6 hexamethylene diisocyanate, the method described in JP-A-01-33115 can be used. Cyclic diisocyanates, etc., and prepolymers thereof can be used in combination, and those having a polyisocyanate content of 99% by weight or more are used.

As the polyisocyanate used in the present invention, those having an NCO% of 15 to 25% by weight can be used, and polyisocyanates having an NCO% of 20 to 25% by weight are more preferable. If it is less than 15% by weight, the strength of the coating film may be insufficient, and if it exceeds 25% by weight, the amount of polyisocyanate having an isocyanurate structure decreases, and conversely, polyisocyanate that is not trimerized, such as diisocyanate, is used. As a result, the strength of the coating film is also insufficient.

In addition, the viscosity of the polyisocyanate used in the present invention is preferably 500 to 3500 mPa s/25°C. Workability may decrease when applying to.

Further, the polyisocyanate used in the present invention is 20 to 35 parts by weight in 100 parts by weight of the entire composition. If it is less than 20 parts by weight, the strength of the coating film may be insufficient. It may be shortened and the workability may be insufficient.

The organometallic catalyst used in the present invention is blended to accelerate the curing of the present composition. Organometallic catalysts such as tin dilaurate, dibutyltin dichloride, lead octylate, lead naphthenate and bismuth octylate can be used. Among these curing catalysts, organic tin compounds are more preferred. Among these curing catalysts, dibutyltin diacetylacetonate, dibutyltin diacetate, dibutyltin dilaurate, and dibutyltin dichloride are more preferable from the viewpoint of catalytic effect. The amount of the organometallic catalyst is 0.005 to 0.05 parts by weight based on 100 parts by weight of the entire composition. If it exceeds 0.05 part by weight, the curing may be accelerated and the surface properties of the coating film may be poor.

As the hydraulic cement used in the present invention, it is preferable to use mainly white Portland cement so that a specific color tone can be imparted. In addition, ordinary Portland cement, alumina cement, blast-furnace cement, high-early-strength Portland cement, etc. are used in combination. can do The amount of hydraulic cement is preferably 10 to 30 parts by weight based on 100 parts by weight of the entire composition. Etc., the coating workability when coating on the surface of the underlying concrete is reduced.

As the aggregate used in the present invention, silica sand, calcium carbonate, aluminum hydroxide, etc. having a particle size of 0.7 mm to 0.05 mm can be used. If the particle size is more than 0.7 mm, the surface smoothness of the coating film may be poor when applied to the surface of the subfloor concrete. diminished sexuality.

The amount of aggregate to be added is 25 to 50 parts by weight in 100 parts by weight of the total composition. Impact resistance may decrease.

The hydraulic polymer cement composition of the present invention is applied to the surface of the underlying concrete by using a metal trowel, roller brush, or the like to apply the composition to a thickness of 0.2 mm or more and less than 4.0 mm, and then as an undercoat to a thickness of 0.2 mm or more. After coating to a thickness of less than 1.5 mm and curing, it is desirable to finish by coating the hydraulic polymer cement composition of the present invention as a top coat to a thickness of 1.0 mm or more and less than 4.0 mm. By applying the composition in two steps in this way, pinholes and the like do not occur in the cured coating film of the topcoat, and a beautiful coated floor can be obtained.

Examples and comparative examples will be described below in detail.

<Examples and Comparative Examples>
As a water-dispersed polyol, 25 to 33 parts by weight of a castor oil-based bifunctional polyol is contained with respect to 100 parts by weight of a castor oil-based trifunctional polyol, and a water-dispersed polyol A having a hydroxyl group equivalent of 200 to 250 as a whole (water content: 25 ~ 30% by weight) and 14 to 20 parts by weight of a castor oil-based bifunctional polyol per 100 parts by weight of a castor oil-based trifunctional polyol, and the hydroxyl group equivalent as a whole is 200 to 500 Water-dispersed polyol B (water-containing Amount: 25 to 30% by weight), and as a polyisocyanate, polyisocyanate A of hexamethylene diisocyanurate (viscosity 2500 mPa s / 25 ° C., NCO%: 20% by weight, polyisocyanate content 99% by weight or more) and polyisocyanate B (NCO wt%: 31.0 wt%), which is 4,4'-diphenylmethane diisocyanate, Neostan U220H (dibutyltin diacetylacetonate) as an organometallic catalyst, and tributyltin as an amine catalyst. Ethylenediamine was used, Tohoku Silica Sand No. 6 with a particle size of 0.6 to 0.05 mm was used as the aggregate, and white Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) was used as the hydraulic cement. Hydraulic polymer cement compositions of Examples and Comparative Examples were prepared. In the following evaluation, Examples 1 and 2 and Comparative Examples 1 to 4 were evaluated after finishing the coating film thickness to 2 mm, and Example 3 was finished so that the coating film thickness was 4 mm. evaluated.

<Evaluation items and evaluation methods>

<Paint film surface smoothness>
At 23 ° C., on the surface of a dry concrete plate of 300 mm × 300 mm × 60 mm in thickness of JISA 5371 (5% or less in Kett Moisture Meter HI-520 Concrete Range), Examples 1 and 2 and Comparative Examples 1 to Comparative For Example 4, the uniformly mixed hydraulic polymer cement compositions of Examples 1 and 2 and Comparative Examples 1 to 4 were first applied as an undercoat to a thickness of 0.2 mm or more and less than 1.0 mm. After curing, the same material is further applied as a topcoat to a thickness of 1.0 mm or more and less than 2.5 mm, and the undercoat and topcoat after curing are finished so that the coating thickness is 2 mm. For 3, the uniformly mixed hydraulic polymer cement composition of Example 3 was first applied as a base coat to a thickness of 0.5 mm or more and less than 1.5 mm and cured, and then the same material was applied as a top coat 2 It was applied to a thickness of 0 mm or more and less than 4.0 mm, and finished so that the thickness of the undercoat and top coat after curing would be 4 mm, and the surface condition of the coating film was visually observed. A smooth finish was evaluated as ◯, and an uneven finish was evaluated as x.

<Impact resistance>
At 23 ° C., on the surface of a dry concrete plate of 300 mm × 300 mm × 60 mm in thickness of JISA 5371 (5% or less in Kett Moisture Meter HI-520 Concrete Range), Examples 1 and 2 and Comparative Examples 1 to Comparative For Example 4, the uniformly mixed hydraulic polymer cement compositions of Examples 1 and 2 and Comparative Examples 1 to 4 were first applied as an undercoat to a thickness of 0.2 mm or more and less than 1.0 mm. After curing, the same material is further applied as a topcoat to a thickness of 1.0 mm or more and less than 2.5 mm, and the undercoat and topcoat after curing are finished so that the coating thickness is 2 mm. For 3, the uniformly mixed hydraulic polymer cement composition of Example 3 was first applied as a base coat to a thickness of 0.5 mm or more and less than 1.5 mm and cured, and then the same material was applied as a top coat 2 It is applied to a thickness of 0 mm or more and less than 4.0 mm, and finished so that the thickness of the undercoat and top coat after curing will be 4 mm. After curing for 7 days, drop a steel ball of 1 kg from a height of 1 m into the center 60 times. evaluated.

<Compressive strength>
The hydraulic polymer cement compositions of Examples and Comparative Examples were cured at 23° C., and after curing for 7 days, the compression strength (N/mm ² ) of the cured products was measured according to JISK6911. The size of the specimen was 13 mm×13 mm×25 mm. If the compressive strength exceeds 25 N/mm ² , it is considered to have sufficient strength and is evaluated as ◯.

<Adhesion>
At 23 ° C., on the surface of a dry concrete plate of 300 mm × 300 mm × 60 mm in thickness of JISA 5371 (5% or less in Kett Moisture Meter HI-520 Concrete Range), Examples 1 and 2 and Comparative Examples 1 to Comparative For Example 4, the uniformly mixed hydraulic polymer cement compositions of Examples 1 and 2 and Comparative Examples 1 to 4 were first applied as an undercoat to a thickness of 0.2 mm or more and less than 1.0 mm. After curing, the same material is further applied as a topcoat to a thickness of 1.0 mm or more and less than 2.5 mm, and the undercoat and topcoat after curing are finished so that the coating thickness is 2 mm. For 3, the uniformly mixed hydraulic polymer cement composition of Example 3 was first applied as a base coat to a thickness of 0.5 mm or more and less than 1.5 mm and cured, and then the same material was applied as a top coat 2 It is applied to a thickness of 0 mm or more and less than 4.0 mm, and finished so that the thickness of the undercoat and top coat after curing will be 4 mm. After curing for 7 days, the adhesive strength (N/mm ² ) between the hydraulic polymer cement composition in a 40×40 mm portion and the concrete flat plate was measured using a construction research type adhesion tester. The state of failure was evaluated as ◯ for 100% cohesive failure of the underlying concrete and x for other cases.

<Peeling resistance>
For the hydraulic polymer cement compositions of Examples 1 to 3 and Comparative Examples 1 to 4, the cured products were molded into strips of length 160 mm×width 10 mm×thickness 2 mm. For the cement composition, the cured product was molded into strips of length 160 mm x width 10 mm x thickness 4 mm, each of which was cured at 23°C for 7 days and then heat-cured at 50°C for 14 days. to measure. Next, it is pulled in the longitudinal direction at a speed of 1 mm/min, and the tensile elastic modulus E (N/mm ² ) is measured. The shrinkage stress per unit cross-sectional area of the coating film (N/mm ² ) was calculated by the following formula (1) from the shrinkage strain amount L (mm) and the length L ₀ (mm) of the specimen after curing for 7 days at 23°C. Further, the coating film shrinkage force per unit width of the coating film T ( N/mm) was obtained.
Shrinkage stress (N/mm ² ) = E (L/L ₀ ) (1)
Here, the coating film shrinkage force T (N/mm) is empirically considered to act in the direction of peeling the coating film, so the coating film shrinkage force at this time is shown in FIG. It is assumed that the coating film is peeled off by pulling the coating film at a shallow angle of about 5 degrees, and the vertical force per unit width (mm) of the coating film Tv (N/mm ).
Vertical force Tv (N/mm)=sin5°×T (2)
This vertical force Tv (N / mm) per unit width (1 mm) is applied to 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 2 mm or 4 mm. Considering this, the force in the vertical direction acts to pull the coating film in the vertical direction with respect to the unit surface area (1 mm ² ) of the underlying concrete, and this was taken as the vertical stress Tv ₂ (N/mm ² ).

Based on that, first, Fig. 2 shows the relationship between the surface tensile strength of the base concrete and the rate of residual laitance at a water/cement ratio of 60% (Effect of the base concrete on the occurrence of blistering of the floor, Architectural Institute of Japan Structure Series of Papers, No. 493, 1-7, March 1997, see Table 1 and Figure 12 (air-dried state).From Figure 12 (air-dried state), only those with cohesive failure of the base are extracted and shown. ) and the normal stress Tv ₂ (N/mm ² ), even if 100% of the laitance remains in the base concrete, the surface tensile strength of the base is 0.7 N/mm ² As (usually, the base concrete from which all the laitance has been removed has a base concrete specification suitable for the construction of the floor coating material), the normal stress Tv ₂ (N/mm ² ) is higher than the 0.7 N/mm ² If it was small, it was considered that the coating film would not separate from the base concrete only by the action of the shrinkage force of the coating film, and was evaluated as ⊚. When the normal stress Tv ₂ (N/mm ² ) is greater than the surface tensile strength of the base concrete 0.7 N/mm ² (laitance residual rate of 100%), the coating film is compressed to the base by the action of only the shrinkage force of the coating film. It was evaluated as × because the surface of the concrete may be destroyed and peeled off.

In this case, a groove with a depth of 3 to 7 mm and a width of 3 to 7 mm is provided at the edge of the floor concrete as in the conventional case, and if the distance between the opposing grooves is more than 12 m, A joint with a depth of 3 to 7 mm and a width of 3 to 7 mm must be provided every 12 m or less, and the composition must be applied to the subfloor concrete while filling the groove and joint with the composition. Conversely, if the vertical stress Tv ₂ (N/mm ² ) is smaller than 0.7 N/mm ² , it is determined that such grooves are unnecessary.

In addition, in the 2012 version of the lacquered floor handbook (issued on March 1, 2012, supervised by Yutaka Yokoyama, edited and written by the Japan Painted Floor Industry Association, published and sold by Kobunsha), the new concrete used as the base for the lacquered floor・Since the surface (tensile) strength as one of the qualities of mortar and 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 ), and if the normal stress Tv ₂ (N/mm ² ) is smaller than 1.5 N/mm ² , the coating film can be peeled off from the base concrete only by the action of the shrinkage force of the coating film. It was evaluated as ○ because it was considered that there was no such thing. When the normal stress Tv ₂ (N/mm ² ) is greater than the surface (tensile) strength of 1.5 N/mm ² , the paint film breaks and peels off the surface of the underlying concrete only by the action of the contractile force of the paint film. It was evaluated as × because there was a case.

In this case, in the same way as in the case of the base concrete with a water/cement ratio of 60%, a groove with a depth of 3 to 7 mm and a width of 3 to 7 mm is provided at the edge of the base concrete as in the conventional method. When the distance between the grooves facing each other is more than 12 m, a joint having a depth of 3 to 7 mm and a width of 3 to 7 mm is provided every 12 m from the groove, and the groove and the joint are filled with the composition. On the other hand, it must be applied on the floor subfloor concrete, and conversely, if the vertical stress Tv ₂ (N/mm ² ) is smaller than 1.5 N/mm ² , it is not necessary to provide such a groove. It is judged that there is none.

<Yellowing resistance>
Black light (sterilization lamp, peak wavelength 256 nm, 31 μW /cm ² ) was irradiated from a height of 50 cm for 200 hours, and the color difference (ΔE) before and after irradiation was measured. When ΔE was 1.0 or less, it was evaluated as ○, and when ΔE exceeded 1.0, it was evaluated as x.

<Evaluation results>
Table 2 shows the evaluation results.

Claims (3)

A hydraulic polymer cement composition comprising a water-dispersed polyol, a polyisocyanate, an organometallic catalyst, glycerin, a hydraulic cement and an aggregate,
The water-dispersed polyol consists of water, a castor oil-based bifunctional polyol, and a castor oil-based trifunctional polyol, and has a hydroxyl equivalent of 200 to 600 and is 10 to 25 parts by weight in 100 parts by weight of the entire composition,
The castor oil-based bifunctional polyol is more than 0 parts by weight and 40 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 consists of an aliphatic isocyanurate, and the polyisocyanate is 20 to 35 parts by weight in 100 parts by weight of the total composition,
The organometallic catalyst is an organotin compound and is 0.005 to 0.05 parts by weight in 100 parts by weight of the entire composition,
Hydraulic cement is 10 to 30 parts by weight in 100 parts by weight of the entire composition,
Aggregate is 25 to 50 parts by weight in 100 parts by weight of the total composition,
A hydraulic polymer cement composition characterized by: A hydraulic polymer cement composition according to claim 1, characterized in that the polyisocyanate is hexamethylene diisocyanurate. The hydraulic polymer cement composition according to claim 1 or claim 2 is applied as an undercoat to the surface of subfloor concrete to a thickness of 0.2 mm or more and less than 1.5 mm and cured, and then the hydraulic polymer is applied. A method for applying a hydraulic polymer cement composition, characterized in that the cement composition is applied as a topcoat to a thickness of 1.0 mm or more and less than 4.0 mm.

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