JP2016017116A - Coating agent for floor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating agent for a floor capable of forming a coating sufficiently high in hardness and excellent in heal mark resistance and adhesion with a vinyl tile.SOLUTION: Provided is a coating agent for a floor comprising: a main agent comprising a water-dispersed body of an acrylic polymer having a carboxyl group as an active hydrogen group and having a glass transition temperature of 70°C or higher and a water-dispersed body of an urethane polymer; and a hardening agent comprising polycarbodiimide and/or polyisocyanate.SELECTED DRAWING: None

Description

  The present invention relates to a floor coating agent.

  Conventionally, various coating agents for vinyl tile floors have been developed. The floor coating agent is preferably aqueous from the viewpoint of workability during application.

JP 2011-105857 A JP 2010-13559 A JP 2006-143939 A JP 2010-47689 A JP-A-1995-49566

  Conventional floor coating agents are prone to heel marks and scratches that are dirt on the floor caused by things that come into contact with the floor, such as shoes, and therefore need to be reapplied twice to six times a year.

  The present invention provides a floor coating agent that has a sufficiently high hardness and can form a coating having excellent heel mark resistance (that heel marks hardly occur) and excellent adhesion to a vinyl tile.

  The present invention includes a main agent containing an aqueous dispersion of an acrylic polymer and an aqueous dispersion of a urethane polymer having at least a carboxy group as an active hydrogen group and a glass transition temperature of 70 ° C. or higher, a polycarbodiimide and / or a polycarbodiimide. And a curing agent containing an isocyanate.

  By using the floor coating agent, it is possible to obtain a coating having a sufficiently high hardness and excellent heel mark resistance and adhesion to a vinyl tile. Moreover, since the floor coating agent is water-based, it has little influence on the environment and has high durability, so that the frequency of reapplication can be reduced.

  The floor coating agent preferably further contains an aqueous dispersion of wax as a main agent. By including an aqueous dispersion of wax, it is possible to obtain a coating that is less likely to be soiled.

  The melting point of the wax is preferably 125 to 130 ° C. By setting the melting point within this range, the heel mark resistance can be further improved.

  It is preferable that content of an acrylic polymer is 45-68 mass% with respect to the total amount of an acrylic polymer and a urethane polymer. By making content of an acrylic polymer into the said range, the adhesiveness of a coating and a vinyl tile can be improved.

  The glass transition temperature of the acrylic polymer is preferably 85 ° C. or higher. Thereby, the hardness and heel mark resistance of the coating can be further improved, and scratches are less likely to adhere to the coating.

  The floor coating agent can be a one-pack type in which the curing agent contains polycarbodiimide and the main agent and the curing agent coexist. By making it one-pack type, there is no trouble when measuring and mixing the main agent and curing agent, and it does not include the step of blending the optimal amount of curing agent with the main agent, so the main agent / curing agent ratio varies. And the resulting coating performance stability is improved.

  The polycarbodiimide may be an aqueous solution or an aqueous dispersion of polycarbodiimide. When the curing agent is provided as an aqueous solution or a water dispersion, when mixing with the main agent to produce a floor coating agent, not only mixing is facilitated, but also the dispersibility of the curing agent is increased and the resulting coating is obtained. Improved performance.

  In the floor coating agent, after the curing agent contains polyisocyanate, it can be a two-component type in which the main agent and the curing agent exist separately. By using a two-component type, the curing reaction does not proceed during storage, and the storage stability (pot life) is excellent.

  The polyisocyanate is preferably a polyisocyanate aqueous dispersion having an average particle size of 100 nm or less. When the average particle size of the polyisocyanate aqueous dispersion is 100 nm or less, the pot life of the floor coating agent becomes longer.

  Provided is a floor coating agent which can form a coating having a sufficiently high hardness and excellent heel mark resistance and adhesion to a vinyl tile.

It is a figure showing the result of the heel mark-proof evaluation test about the coating obtained in Example 10 and Comparative Examples 7 and 8. It is a figure showing the result of the heel mark-proof evaluation test about the coating obtained in Example 11 and Comparative Examples 7 and 8.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  The floor coating agent according to the present embodiment includes a main agent and a curing agent, and a coating film is generated by a reaction between the main agent and the curing agent.

  The main agent essentially contains an aqueous dispersion of an acrylic polymer (hereinafter referred to as “acrylic dispersion”) and an aqueous dispersion of a urethane polymer (hereinafter referred to as “urethane dispersion”). Here, the aqueous dispersion means a solid component such as an acrylic polymer or a urethane polymer dispersed in an aqueous medium in the form of particles, and an emulsion produced by emulsion polymerization or a dispersion produced by suspension polymerization. The concept includes John and the like (hereinafter, the same applies to the curing agent). The aqueous dispersion only needs to cause fluidity in the floor coating when the floor coating is applied.

  The acrylic polymer constituting the acrylic dispersion is a polymer skeleton (main chain or side chain) derived from a monomer having an acryl or methacryl (hereinafter sometimes referred to as “(meth) acryl”) group. The polymer which comprises at least one part.

  This acrylic polymer has at least a carboxy group as an active hydrogen group. Examples of the active hydrogen group include a carboxy group, an alcoholic hydroxyl group, a phenolic hydroxyl group, an amino group, and a mercapto group. Since the acrylic polymer has a carboxy group, it can react with polycarbodiimide as a curing agent to cause crosslinking. Moreover, a carboxy group and other active hydrogen groups can react with polyisocyanate which is a curing agent to cause crosslinking.

  The acrylic polymer is usually obtained by polymerizing one or more of (meth) acrylic monomers, which are monomers having a (meth) acrylic group, together with a copolymerization monomer to be used optionally, and has an active hydrogen group. An active hydrogen group can be introduced into the acrylic polymer by using the (meth) acrylic monomer and / or copolymerization monomer. A typical example of the copolymerizable monomer is a compound having an ethylenically unsaturated bond (excluding a (meth) acrylic monomer).

  Examples of the (meth) acrylic monomer having a carboxy group include (meth) acrylic acid, and the (meth) acrylic monomer having an active hydrogen other than the carboxy group includes hydroxyethyl (meth) acrylate, Examples thereof include hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate; unsubstituted or N-substituted (meth) acrylamides such as acrylamide and N-alkylacrylamide. Moreover, itaconic acid is mentioned as a copolymerization monomer which has a carboxy group. The skeleton of the copolymerizable monomer having a hydroxyl group which is an active hydrogen other than a carboxy group is a vinyl alcohol monomer skeleton generated as a saponified product of vinyl ester such as vinyl acetate.

  Examples of other monomers constituting the acrylic polymer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, and isobornyl (meth) acrylate. ) Alkyl acrylate; N, N-substituted dialkyl (meth) acrylamides such as N, N-dimethylacrylamide; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate; Acrylonitrile; Styrene, all of which are ethylenic This corresponds to a compound having an unsaturated bond.

  The acrylic polymer has a glass transition temperature of 70 ° C. or higher. When the glass transition temperature of the acrylic polymer is in the above range, it is possible to obtain a highly durable coating having sufficient hardness, excellent heel mark resistance, hardly scratching. The glass transition temperature is preferably 80 ° C. or higher, and more preferably 85 ° C. or higher. The higher the glass transition temperature of the acrylic polymer, the better the hardness of the coating and the heel mark resistance, and the more difficult it is to get dirt and scratches. The glass transition temperature of the acrylic polymer can be measured by DSC, for example, at a heating rate of 10 ° C./min.

  The content of the acrylic polymer in the total amount of the main agent can be 8 to 12% by mass, preferably 10 to 11% by mass, when the solid content ratio of the main agent is about 22% by mass.

  The urethane polymer constituting the urethane dispersion means a polymer having a urethane bond, and is usually obtained by a reaction between a polyol and a polyisocyanate. Any polyol such as polyester polyol and polyether polyol can be used as the polyol, and any polyisocyanate such as aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate can be used as the polyisocyanate. Since the urethane polymer exists in water, the urethane polymer preferably has as few free isocyanate groups as possible. This can be achieved by reacting with the number of equivalents of polyol being equal to or greater than the number of equivalents of polyisocyanate. The urethane polymer may have a bond other than the urethane bond, such as a urea bond.

  The urethane dispersion may be any of a dispersion type, a self-emulsification type, a forced emulsification type, and may have a functional group. When the solid content ratio of the main agent is about 22% by mass, the content of the urethane polymer in the total amount of the main agent can be 4 to 6% by mass, and preferably 5 to 5.5% by mass.

  Content of an acrylic polymer can be 20-80 mass% with respect to the total amount of an acrylic polymer and a urethane polymer, for example. The content of the acrylic polymer is preferably 45 to 80% by mass, more preferably 45 to 68% by mass, and preferably 66 to 68% by mass with respect to the total amount of the acrylic polymer and the urethane polymer. Further preferred. That is, the content of the urethane polymer is preferably 20 to 55% by mass, more preferably 32 to 55% by mass, and more preferably 32 to 34% by mass with respect to the total amount of the acrylic polymer and the urethane polymer. Is more preferable. By containing the urethane polymer in the above range in the main agent, the adhesion of the coating to the vinyl tile is improved.

  The main agent may further contain a wax. When the main agent contains a wax, the smoothness and gloss of the coating are improved, dirt is less likely to be attached, and the heel mark resistance is improved.

  As the wax, natural or synthetic wax can be used. As the natural wax (wax), any of vegetable and animal waxes may be used. As the synthetic wax, for example, polyalkylene wax such as polyethylene wax and polypropylene wax can be used. The wax added to the main agent may be an aqueous dispersion of wax. Examples of the aqueous dispersion of wax include an aqueous wax emulsion that can be obtained by adding an emulsifier and water to a wax and emulsifying the wax.

  The melting point of the wax may be, for example, 120 to 135 ° C. The melting point of the wax is preferably 125 to 130 ° C, more preferably 125 ° C. When the melting point of the wax is within the above range, the heel mark resistance of the coating is improved. Furthermore, since the melting point of the wax is 125 to 130 ° C., it is difficult to slip even when the coating is wet.

  The content of the wax can be, for example, 1 to 15% by mass in the total amount of the floor coating agent. A wax content of 3% by mass or more is preferable because the heel mark resistance is improved. Further, when the content of the wax is 10% by mass or less, the coating can be made difficult to slip, and particularly, even when the coating surface is wet, it can be made difficult to slip.

  In addition, the main agent may further contain additives such as finely divided silica, leveling agent, antifoaming agent, preservative, ultraviolet absorber, stabilizer and the like.

  When the main agent contains finely divided silica, the hardness of the coating and the heel mark resistance can be improved. When the main agent contains finely divided silica, the content of finely divided silica can be 0.2 to 5% by mass, for example, 0.5 to 1% by mass in the solid content of the floor coating agent. it can.

  When a main ingredient contains a leveling agent, content of a leveling agent can be 0.1-1.0 mass% in the floor coating agent whole quantity. When the main agent contains a leveling agent, the floor coating agent can be applied more uniformly while suppressing repellency. As a leveling agent, a well-known thing can be used, For example, a polydimethylsiloxane solution etc. can be used. Moreover, when a main ingredient contains an antifoamer, content of an antifoamer can be 0.1-0.4 mass% with respect to the coating agent for floors. When the main agent contains an antifoaming agent, a smoother and better-appearance coating can be obtained.

  The main agent may use, for example, water, butyl glycol, butyl diglycol, dipropylene glycol dimethyl ether (DMM) or the like as a solvent. A solvent may be used individually by 1 type and may use 2 or more types together. The content of the solvent other than water is preferably 2 to 15% by mass in the total amount of the main agent.

  The curing agent in the floor coating agent contains polycarbodiimide and / or polyisocyanate. The hardening | curing agent should just contain the polycarbodiimide and / or polyisocyanate which contribute to hardening, and may contain additional components other than these. Examples of the additive component include a solvent (diluent) such as dipropylene glycol dimethyl ether (DMM).

Polycarbodiimide is a compound having a plurality of carbodiimide groups in the molecule, and can be represented by, for example, a general formula of-(RN = C = N) _n- (wherein R is a divalent organic group, n Is a number of 2 or more). The carbodiimide group of the polycarbodiimide can react with the carboxy group in the acrylic polymer to form a crosslink. When making a floor coating agent into a one-pack type, it is preferable to use a polycarbodiimide having a lower reactivity with a carboxy group. Thereby, the pot life of the floor coating agent can be further extended. As such a polycarbodiimide, for example, a polycarbodiimide having an aromatic ring or a cycloalkylene in the molecule can be used, and for example, dicyclohexylcarbodiimide, dicyclohexylmethanecarbodiimide, tetramethylxylylenecarbodiimide, or the like can be used. it can. As an aqueous dispersion of polycarbodiimide, for example, an aqueous solution, an emulsion, a dispersion or the like can be used.

  When the curing agent contains polycarbodiimide, the floor coating agent can be either a one-component type or a two-component type, but can be suitably used as a one-component type floor coating agent. By using polycarbodiimide as the curing agent, even if the main agent and the curing agent are mixed and coexist, the reaction between the main agent and the curing agent is extremely difficult to proceed. Even in this case, the floor coating agent can be stored more stably for a long period of time. Therefore, by using polycarbodiimide as a curing agent, the pot life of the floor coating agent can be further extended, for example, for floors stably for 6 months or more, 1 year or more, 2 years or more, etc. The coating agent can be stored. In addition, since the floor coating agent has a long pot life, it can prevent the floor coating agent adhering to the used mop from sticking after applying the floor coating agent using a mop or the like. preferable.

  The content of the polycarbodiimide can be, for example, 15 to 50% by mass, or 40 to 50% by mass in the total amount of the curing agent. You may use together polycarbodiimide and the polyisocyanate mentioned later as a hardening | curing agent.

  Polyisocyanate has a plurality of isocyanate groups in the molecule. As the polyisocyanate, any polyisocyanate such as aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate can be used. The polyisocyanate may be an adduct of polyisocyanate and polyol.

  The polyisocyanate is preferably an aqueous dispersion. In order to avoid reaction of the medium with water, the polyisocyanate particles in the aqueous medium should be protected with a sufficient amount of emulsifier or the like, or during the production of the aqueous dispersion of polyisocyanate, for example, with water. It is preferable to form a polyurea thin film on the surface of the polyisocyanate particles by reaction.

  When polyisocyanate is used as the curing agent, the floor coating agent can be either one-component type or two-component type. In the case of long-term storage before coating, a two-pack type floor coating agent in which the main agent and the curing agent exist separately is preferable. The aqueous dispersion of polyisocyanate may be diluted with a solvent such as dipropylene glycol dimethyl ether before being mixed with the main agent. When diluting, it is preferable to dilute with the same amount or more of the solvent relative to the polyisocyanate aqueous dispersion. In the conventional two-pack type floor coating agent, when the coating is peeled off at the time of re-application, etc., it is very difficult to peel off and it is necessary to file, but in the floor coating agent according to this embodiment, the two-pack type Even if it is a case, it is excellent in releasability and can easily peel off the coating using a commercially available release agent.

  The average particle size of the polyisocyanate aqueous dispersion is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 30 nm or less. The polyisocyanate can be reduced in particle size by preliminarily applying a high shearing force with a high shear mixer or the like before mixing with the main agent. By setting the average particle size of the polyisocyanate aqueous dispersion to 100 nm or less, the pot life before coating can be lengthened even when the main agent and the curing agent are mixed into one liquid. The pot life after mixing the main agent and the curing agent in the one-pack type or in the two-pack type floor coating agent can be, for example, 5 hours or more, 1 day or more, or 1 week or more. The average particle size of the polyisocyanate aqueous dispersion can be measured by, for example, a COULTER LS13 320 laser particle size measuring machine (manufactured by Beckman Coulter, Inc.).

  In the floor coating agent, the amount of the curing agent is preferably 2.0 to 15.0 mass%, more preferably 4.0 to 15.0 mass%, based on the total amount of the floor coating agent.

  The ratio between the main agent and the curing agent can be obtained from the content of active hydrogen groups in the main agent and the content of carbodiimide groups and isocyanate groups in the curing agent by calculating the equivalent, etc. It is also possible to evaluate the performance of the agent and make the ratio optimal for the application.

  When the coating agent for floors is a two-component type, the main agent and the curing agent are sufficiently mixed, and then can be applied to an application target using a known method. A desired coating can be obtained by air-drying after application | coating.

  The coating obtained using the floor coating agent can be easily peeled off from the object to be coated such as a floor when necessary. Examples of the peeling method include a method of peeling using a super strong non-rinsing release agent (manufactured by Johnson Professional) that is a commercially available non-rinsing release agent. The floor coating agent can be suitably used for vinyl tile floors.

  Hereinafter, the present invention will be described in detail based on examples. The present invention is not limited to the following examples.

(Test Example 1)
A floor coating agent was prepared according to the formulation shown in Table 1. Acrylic polymer emulsion, urethane polymer emulsion, finely divided silica, antifoaming agent, leveling agent, wax emulsion, butyl glycol / butyl diglycol equivalent liquid mixture and distilled water using the mixing ratio shown in Table 1 (unit is part by mass) Was mixed with a propeller mixer for 10 minutes to obtain a mixed solution as a main agent. Separately, polyisocyanate diluted with dipropylene glycol dimethyl ether and stirred with a propeller mixer or polycarbodiimide was prepared as a curing agent. An aqueous mixture obtained by stirring at 8000 rpm or more for 10 minutes or more using a high-speed high shear mixer while adding the curing agent little by little to the main agent was used as a floor coating agent, and used for subsequent evaluation tests or coatings.

Mop (Easy Clean Flat Mop, manufactured by 3M Co., Ltd.) is sufficiently sucked with the above floor coating agent, applied to vinyl tile (Vinyl Tile P-1, manufactured by Tajima Co., Ltd.), and dried for 30 minutes while blowing with a fan. And applied twice. One application amount was 10 to 15 ml / m ² . Furthermore, what was left to stand at room temperature for 4 days was used as a coating in subsequent evaluation tests.

(Test Example 2)
Floor coating agents were prepared using the ratios shown in Table 3 (unit: parts by mass). When polyisocyanate is used as a curing agent, the test is conducted except that the polyisocyanate is diluted with dipropylene glycol dimethyl ether and a high shear high speed mixer (TK HOMO MIXER manufactured by Special Machinery Co., Ltd.) is finely dispersed at 8000 rpm for 10 minutes or more. A floor coating agent was prepared in the same manner as in Example 2. In addition, as a coating method, a floor coating agent was applied to a vinyl tile in the same manner as in Test Example 1, dried, and then applied and dried again in the same manner, and used as a coating for evaluation.

(Test Example 3)
Floor coating agents were prepared using the ratios shown in Table 5 (unit: parts by mass). The preparation method and coating method are the same as in Test Example 1.

Details of the components shown in the table are as follows.
Bihydrol UH2342 (urethane polymer dispersion): fatty acid-modified polyurethane, non-volatile content 35%, Bayer's bihydrol UH2606 (urethane polymer dispersion): Polycarbonate polyurethane, non-volatile content 35%, Bayer's bihydrol A2427 (acrylic polymer dispersion): Hydroxyl group-containing acrylic, glass transition temperature 86 ° C., non-volatile content 42%, Bayer's bihydrol A2457 (acrylic polymer dispersion): hydroxyl group-containing acrylic, glass transition temperature 65 ° C., non-volatile content 42%, Bayer's butyl glycol / butyl diene Glycol = 1 (mass ratio) mixed solution Dispercoll S3030 (micronized silica): amorphous silicon dioxide anionic colloidal solution, solid content 30 %, Particle size 9 nm, Bayer BYK-011 (antifoaming agent): non-silicon polymer antifoaming agent, non-volatile content 29.0%, BYK-306 BYK-306 (leveling agent): polyether-modified polydimethylsiloxane Solution, non-volatile content 12.5% BYK-349 (leveling agent) manufactured by Big Chemie: polyether-modified siloxane, non-volatile content 94% or more, modified AC polyethylene 39 (wax) manufactured by Big Chemie: oxidized high density polyethylene wax anionic emulsion AQUACER 1547 (wax) manufactured by Honeywell Co., Ltd .: Oxidized high-density polyethylene wax anionic emulsion, 35% non-volatile content, wax melting point 125 ° C., AQUACER 515 (wax) manufactured by Big Chemie: oxidized high-density polyethylene Wax nonionic emulsion, non-volatile content 35%, wax melting point 135 ° C., BYHIJUL 305 (polyisocyanate) manufactured by Big Chemie: hydrophilic group-containing polyisocyanate, non-volatile content 100%, carbodilite V-02-L2 (polycarbodiimide) manufactured by Bayer ): Water-soluble polycarbodiimide, active ingredient 40%, dipropylene glycol dimethyl ether manufactured by Nisshinbo Co., Ltd. manufactured by Dow Chemical Co. In Test Example 3, a commercially available scotch guard wax for a resilient floor (manufactured by 3M Co.) was used as Comparative Example 7, NH Neo floor Wax (manufactured by Linley) was used as Comparative Example 8.

  The following evaluation tests were performed on the floor coating agents or coatings of Test Examples 1 to 3. The results are shown in Tables 2, 4 and 6, respectively.

<Heel mark resistance>
The heel mark resistance of the coating was evaluated according to JIS K3920. The degree of the heel mark attached to the coating surface was visually examined. In Test Examples 1 and 2, an evaluation was made in five stages from a case where no heel mark was attached (5) to a case where the heel mark was always attached (1). In Test Example 3, the case where the heel mark did not adhere was evaluated as excellent (、), and evaluated as good (◯), normal (Δ), and defective (×) in the order of decreasing adhesion.

<Abrasion resistance>
Using a rubbing tester IMC-157C (manufactured by Imoto Seisakusho), steel wool Bon Star No. 000 (manufactured by Nippon Steel Wool Co., Ltd.) was rubbed 10 times with a force of 300 g, and the depth of the scratch was visually evaluated. In Test Examples 1 and 2, an evaluation was made in five stages from a shallow one (5) to a deep one (1). In Test Example 3, it was evaluated as normal (Δ) and defective (×).

<Coating properties>
As a coating property, we comprehensively evaluated the wettability when applying a floor coating agent, the presence or absence of air bubbles, and the leveling property of the coating after application, and it is excellent (◎), good (○), normal (△), and poor. (X) was evaluated.

<Pencil hardness>
In accordance with JIS K5600 5-4, the scratch hardness of the coating was examined using a pencil having a hardness of 3B to 9H. After the pencil core was pressed against the coating surface with a constant load and moved, the coating surface was checked for scratches, and the hardness of the hardest pencil core with no scar was evaluated as the pencil hardness.

<Pot life>
The floor coating agent in which the main agent and the curing agent were mixed was stored at 5 to 30 ° C., and the period until the viscosity increased and application became impossible was examined.

<Solvent resistance>
The coating was wiped with a cloth soaked with toluene, acetone or ethanol and dried, and then the coating surface was visually inspected for damage. In Test Examples 1 and 2, the case from no damage (5) to the severe damage (1) was evaluated in five stages. In Test Example 3, no damage was found excellent (◎), little damage was good (○), some damage was normal (△), and severe damage was bad (×). evaluated.

<Adhesiveness>
The adhesion of the coating was evaluated by a tape peeling test in accordance with the cross-cut tape test method of the former JIS K5400. The coating was cut into a grid of 100 squares with a cutter, cellophane tape was attached, and then peeled off, and the number of peeled squares was counted. 100 pieces out of 100 squares are good (◯), 51-89 out of 100 are normal (△), and 50 or less out of 100 are bad (×). .

<Recoatability>
After the floor coating agent was applied, it was reapplied 7 days later, and the appearance and adhesion of the coating were comprehensively examined and evaluated as good (◯), normal (Δ), and poor (×).

<Glossiness>
The glossiness of the coating was measured at an incident angle of 20 ° C. or 60 ° C. using Gloss Checker TMS-723 (Tasco Japan). The values in parentheses are measured values at an incident angle of ° C. In Test Example 1, the incident angle was 20 ° C., in Test Example 2, the incident angle was 60 ° C. and the incident angle was 20 ° C. (in parentheses), and in Test Example 3, the incident angle was 60 ° C.

<Wet friction (slip property when wet)>
In accordance with JIS P8147, the static friction force in the state where the surface of the coating was wetted with water was measured. Those having a static friction force of 0.2 N or more were judged good (◯), and those having a static friction force of less than 0.2 N were judged as normal (Δ).

<Peelability>
The vinyl tile test piece with the above coating was immersed in a commercially available release agent (super strong non-rinse release agent, manufactured by Johnson Professional) for 10 minutes and then washed with water, and the ease of peeling was confirmed. Those that could be easily peeled were evaluated as good (◯), and those that were difficult to peel were evaluated as normal (Δ).

From the results of Test Example 1, it was confirmed that the adhesion of the coating to the vinyl tile was inferior when no urethane polymer was used. Moreover, when the glass transition temperature (Tg) of the acrylic polymer was 65 ° C., it was confirmed that the heel mark resistance was poor.

FIG. 1 is a diagram showing the results of the heel mark resistance evaluation test for the coatings obtained in Example 10 and Comparative Examples 7 and 8, and FIG. 2 is obtained in Example 11 and Comparative Examples 7 and 8. It is a figure showing the result of the heel mark resistance evaluation test about the coating. The floor coating agent of Example 10 is applied to the region a in FIG. 1, and the coating agents of Comparative Examples 7 and 8 are applied to the regions b and c, respectively. Also, the floor coating agent of Example 11 is applied to the area d of FIG. 2, and the coating agents of Comparative Examples 7 and 8 are applied to the areas e and f, respectively. As apparent from FIGS. 1 and 2, the coatings obtained with the floor coating agents of Examples 10 and 11 have superior heel mark resistance as compared with Comparative Examples 7 and 8.

Claims (9)

A main agent containing an aqueous dispersion of an acrylic polymer and an aqueous dispersion of a urethane polymer having at least a carboxy group as an active hydrogen group and a glass transition temperature of 70 ° C. or higher;
A floor coating agent comprising: a curing agent containing polycarbodiimide and / or polyisocyanate.   The floor coating agent according to claim 1, further comprising an aqueous dispersion of wax as the main agent.   The floor coating agent according to claim 2, wherein the wax has a melting point of 125 to 130 ° C.   The floor coating agent according to any one of claims 1 to 3, wherein a content of the acrylic polymer is 45 to 68 mass% with respect to a total amount of the acrylic polymer and the urethane polymer.   The floor coating agent according to any one of claims 1 to 4, wherein the acrylic polymer has a glass transition temperature of 85 ° C or higher.   The floor coating agent according to any one of claims 1 to 5, wherein the curing agent contains polycarbodiimide and is a one-component type in which the main agent and the curing agent coexist.   The floor coating agent according to claim 6, wherein the polycarbodiimide is an aqueous solution or dispersion of polycarbodiimide.   The floor coating agent according to any one of claims 1 to 5, wherein the curing agent is a two-component type containing polyisocyanate, and the main agent and the curing agent are present separately. The floor coating agent according to claim 8, wherein the polyisocyanate is a polyisocyanate aqueous dispersion having an average particle size of 100 nm or less.