JP5262914B2 - POLYMER CEMENT COMPOSITION, MORTAR, AND STRUCTURE USING THEM - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide polymer cement and mortar which are excellent in the tensile strength and the tensile product (tensile strength&times;elongation between gages) of a cured product, can be reduced in stickiness, and are excellent in water resistance with a small discoloration before and after immersion in water, and to provide a structure covered with the mortar. <P>SOLUTION: The polymer cement composition includes a hydraulic composition containing alumina cement, a filler, acrylic resin particulates, and urethane resin particulates, wherein 1-20 pts.mass of the urethane resin particulates are included based on 100 pts.mass of the acrylic resin particulates. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a polymer cement composition, a mortar, and a structure using these, which can obtain a cured product excellent in water resistance.

  A polymer cement in which a resin emulsion or the like is blended with cement is applied (constructed) to, for example, a rooftop, a basement, or a veranda of a concrete structure as a waterproofing material such as a building, a finishing material, and a base conditioning material. As the polymer cement, for example, those disclosed in Patent Documents 1 to 3 below are known.

  In Patent Document 1, 30 to 98% by weight of one or more monomers selected from alkyl (meth) acrylates having an alkyl group having 4 to 10 carbon atoms, 0.1 to 3% by weight of (meth) acrylic acid In addition, a polymer having 0.1 to 5% by weight of glycidyl (meth) acrylate as an essential constituent monomer and a glass transition temperature of −20 ° C. or lower is emulsified and dispersed in water by a cationic or nonionic surfactant. A polymer cement composition (waterproofing material composition) comprising an emulsion and an inorganic hydraulic substance is disclosed.

  Patent Document 2 contains a polymer component, a cement, an aggregate, a water reducing agent, and a water retention agent. The polymer component has an anion having a glass transition temperature (Tg) of −5 ° C. or lower and exceeding −20 ° C. -It consists of a cationic amphoteric alkali curable acrylic-styrene synthetic resin emulsion, and the weight percentage (P / C) of the resin solid content of the emulsion with respect to cement is 30 to 80%. Silica fume fine particles as a component that causes a pozzolanic reaction ( Disclosed is a polymer cement composition (concrete waterproofing composition) characterized by containing 5 to 20% of SiO2 content relative to cement with an average particle diameter of 90% or more and an average particle size of 0.1 to 0.2 μm. Has been.

  Patent Document 3 discloses (A) component: cement, (B) component: resin aqueous dispersion, (C) component: associative thickener, (D) component: two or more sulfonic acid groups in one molecule. A surfactant or a cationic surfactant, wherein the component (C) is 0.01 to 10% by weight, and the component (D) is 0.01 to 10% by weight. %, And the ratio (C / D) of the component (C) to the component (D) is 0.1-15, and a polymer cement composition (cement composition) is disclosed.

JP-A-7-268167 JP-A-11-116313 JP-A-9-221350

  However, the conventional polymer cements disclosed in Patent Documents 1 to 3 have room for improvement in the elongation and tensile strength that can follow movements such as expansion and contraction of the base, that is, the value of tensile product (elongation × tensile breaking strength). is there. In addition, the conventional polymer cement has problems such as high stickiness, which obstructs coating and walking after coating, or discolors when immersed in water.

  Therefore, the present invention has an object to provide a polymer cement composition, a mortar, and a structure using these, which have a high tensile strength value of the cured product, reduce stickiness, and are excellent in water resistance. And

  The first of the present invention is a polymer cement composition containing a hydraulic component containing alumina cement, a filler, acrylic resin fine particles, and urethane resin fine particles.

The second aspect of the present invention is a mortar obtained by kneading a polymer cement composition of the present invention whose filler is sand and water. In addition, when the polymer cement composition contains water, it is not always necessary to add water.
The mortar of the present invention is a homogenous slurry mortar obtained by kneading the polymer cement composition alone or further with water as necessary.

  The third aspect of the present invention is a structure obtained by applying the polymer cement composition or mortar of the present invention to the surface of an object to be coated such as concrete.

Below, the preferable aspect of the polymer cement composition of this invention is shown. A plurality of these can be combined.
1) 1 to 20 parts by mass of urethane-based resin fine particles and 15 to 175 parts by mass of a hydraulic component with respect to 100 parts by mass of acrylic resin fine particles.
2) 1 to 20 parts by mass of urethane resin fine particles and 16 to 350 parts by mass in total of a hydraulic component and a filler with respect to 100 parts by mass of acrylic resin fine particles.
3) Further contain a thickener.
4) The glass transition temperature of the acrylic resin in the acrylic resin fine particles is 0 ° C. or lower.
5) The urethane resin fine particles are fine particles mainly composed of a urethane resin produced by copolymerizing polyol and polyisocyanate.
6) The urethane resin fine particles are fine particles mainly composed of a urethane resin produced by copolymerizing polyisocyanate and polyol, and the polyol is a polycarbonate-polyether block copolymer having two or more hydroxyl groups. Including at least one polyol selected from the group consisting of a polymer, a polyester-polyether block copolymer having two or more hydroxyl groups, a polyester having two or more hydroxyl groups, and a polycarbonate having two or more hydroxyl groups about.
7) 1-20 mass parts of urethane type resin fine particles are included with respect to 100 mass parts of acrylic resin fine particles.

  According to the polymer cement composition of the present invention, a cured product having excellent tensile strength and tensile product (tensile strength x elongation between marked lines), reduced stickiness, small discoloration before and after water immersion and excellent water resistance can be obtained. be able to.

  The present invention is a polymer cement composition having excellent physical properties, including a hydraulic component containing alumina cement, a filler, acrylic resin fine particles, and urethane resin fine particles. According to such a composition, a cured product having excellent tensile strength and tensile product, less stickiness of the cured product, and small discoloration before and after water immersion and excellent water resistance can be obtained.

In the polymer cement composition described above, the discoloration when the cured product is wetted with water and then dried can be reduced by adding alumina cement to the hydraulic component.
The hydraulic component preferably contains 5 parts by mass or more, more preferably 15 parts by mass or more, more preferably 30 parts by mass or more, particularly preferably 50 parts by mass or more of alumina cement in 100 parts by mass of the hydraulic component. Is preferably used.

Alumina cement has a potentially rapid hardening property, and gives a cured product excellent in chemical resistance and fire resistance after curing. Several types of alumina cements having different mineral compositions are known and commercially available, and all of them are mainly composed of monocalcium aluminate (CA). However, in terms of strength and colorability, there are many CA components and C _4. Alumina cement with a small amount of small components such as AF is preferred.

The hydraulic component may contain Portland cement and / or gypsum in addition to alumina cement.
As Portland cement, Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-early strong Portland cement, white Portland cement, mixed cement such as blast furnace cement, fly ash cement, and silica cement can be used.

  As the gypsum, various types of gypsum such as anhydrous and semi-water can be used singly or in combination of two or more, regardless of the type. Gypsum is rapidly hardened and acts as a component for maintaining dimensional stability after curing.

As fillers, sand such as quartz sand, river sand, sea sand, mountain sand, crushed sand, slag powder, fly ash, silica foam, limestone powder, talc, kaolin, alumina powder, titanium oxide, aluminum hydroxide, etc. may be used. it can. In the case of silica sand, the use of No. 5-7 is preferred. These fillers can be used alone or in combination of two or more.
As the filler, it is preferable to use a filler having a particle size of 2 mm or less, further a particle size of 1.5 mm or less, and particularly a particle size of 1 mm or less.
In addition, the polymer cement composition using sands as a filler can be used as a mortar composition.

In the present specification, “acrylic resin fine particles” refers to those that form an emulsion when dispersed in water or a water-containing solvent. As the acrylic resin fine particles, those obtained by polymerizing a monomer component containing a polymerizable component such as a vinyl bond having a carboxyl group such as acrylic acid and methacrylic acid can be used.
Furthermore, as acrylic resin fine particles,
1) those selected from polymerizable components such as vinyl polymerization having a carboxyl group such as acrylic acid and methacrylic acid;
2) Olefin compounds such as ethylene and vinyl acetate; Styrene compounds such as styrene and p-chlorostyrene; Halogenated α-olefin compounds such as vinyl chloride and vinylidene chloride; Methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate Acrylic acid derivatives such as butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, etc. Those obtained by polymerizing a monomer component having a vinyl group can be suitably used.

  The glass transition temperature of the acrylic resin in the acrylic resin fine particles may be any, but is preferably 0 ° C. or lower, more preferably −25 ° C. or lower, particularly preferably −25 ° C. to −50 ° C. The glass transition temperature is preferably 0 ° C. or less, more preferably −25 ° C. or less using a (meth) acrylic acid derivative as a monomer. Particularly preferably, those in the range of −25 ° C. to −50 ° C. can be preferably used.

Especially as acrylic resin fine particles,
The main component is a component selected from (1) methyl (meth) acrylate and ethyl (meth) acrylate, and (2) an alkyl (meth) acrylate having an alkyl group having 4 to 10 carbon atoms. 3) A component selected from acrylic acid and methacrylic acid (preferably component (3) in an amount of 100 parts by mass of the total monomer is 1 part by mass or less, more preferably 0.8% by mass or less, particularly preferably 0.6% by mass. The following three components were copolymerized:
A glass transition temperature of preferably 0 ° C. or lower, more preferably −25 ° C. or lower, particularly preferably −25 ° C. to −50 ° C. is preferable because it has excellent characteristics even in a low temperature environment.

The acrylic resin fine particles are produced by a known production method, for example, a method of emulsion polymerization of a polymerizable monomer that is a raw material of a synthetic resin in water or a hydrous solvent using a polymerization initiator in the presence of an emulsifier. Can be used.

Known emulsifiers can be used, and specific examples thereof include anionic, nonionic, cationic or amphoteric surfactants and protective colloids such as polyvinyl alcohol.
As the polymerization initiator, those capable of initiating radical polymerization in water or a water-containing solvent are preferable, and specific examples thereof include hydrogen peroxide, peracetic acid, persulfuric acid, and water-soluble peroxides such as ammonium salts and sulfates thereof. Examples thereof include oxides and salts thereof. Further, organic peroxides such as benzoyl peroxide, t-butyl hydroperoxide, 2,2′-azobisisobutylnitrile, and reducing agents such as sodium metasulfite and sodium pyrosulfite can be used in combination.
The amount of the polymerization initiator used can be appropriately selected as long as acrylic resin fine particles can be produced.

  The acrylic resin fine particles may be used as an acrylic emulsion dispersed in water or a water-containing solvent, or may be used as powdered resin fine particles not containing water or a water-containing solvent. When powdered synthetic resin particles are used, all components except for water or a water-containing solvent can be made into one package, which is convenient because it can be used simply by adding water at the construction site.

When an acrylic emulsion dispersed in water or a water-containing solvent is used, it can be used by kneading it as it is with a hydraulic component. In addition, for the purpose of adjusting the viscosity and the TI value, water may be added as necessary.
In the case of using powdery resin fine particles not containing water or a water-containing solvent, kneading is performed after adding water in order to produce a homogeneous slurry.

  In the acrylic emulsion dispersed in water or a water-containing solvent, the content of the acrylic resin fine particles contained in the emulsion can be appropriately selected, but is 30 to 80% by mass based on the total amount of the emulsion. Preferably, it is more preferable in it being 40-60 mass%.

  In the present specification, “urethane-based resin fine particles” refers to those that form an emulsion when dispersed in water or a water-containing solvent. As the urethane resin fine particles, those obtained by copolymerizing a polyol and a polyisocyanate can be used, and those commercially available may be used. Furthermore, what has functional groups, such as a carboxyl group and a hydroxyl group, in the structure of the urethane-type resin in a urethane-type resin fine particle and / or the terminal can also be utilized.

  The polyol used for production of the urethane resin fine particles has two or more hydroxyl groups. Specific examples thereof include polyether having two or more hydroxyl groups such as polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), polyethylene adipate (PEA), polydiethylene adipate (PDA). ), Polyesters having two or more hydroxyl groups such as polypropylene adipate (PPA), polycarbonates having two or more hydroxyl groups such as polyhexamethylene carbonate (PHC), etc., any of which may be distributed in the market. You can use what you have. From the viewpoint of water resistance and elongation, it is preferable to use a polyester-polyether block copolymer having two or more hydroxyl groups and / or a polycarbonate-polyether block copolymer having two or more hydroxyl groups. It is more preferable to use a polycarbonate-polyether block copolymer having the above hydroxyl groups.

  The polyisocyanate used for the production of urethane resin fine particles has two or more isocyanate groups. Specific examples thereof include aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI), aromatic polyisocyanates such as toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), and tetramethyl-m-xylidene. Examples include araliphatic polyisocyanates such as diisocyanate (TMXDI), alicyclic polyisocyanates such as isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and the like. The polyisocyanate may be an isocyanate-modified product such as an adduct-modified product, an isocyanurate-modified product, a burette-modified product, an allophanate-modified product, or a carbodiimide-modified product.

  For the production of urethane resin fine particles, in addition to the polyol and polyisocyanate, as chain extenders, glycols such as ethylene glycol, butanediol, hexanediol, ethylenediamine, propylenediamine, isophoronediamine, xylenediamine, diaminolcyclohexylmethane, Diamines such as piperazine and amino alcohols such as diethanolamine can be added.

  The production of urethane resin fine particles includes a method of forcibly emulsifying polyurethane in an aqueous emulsifier solution (strengthening emulsification method), a method of introducing a hydrophilic group into the polyurethane skeleton and ionizing it (self-emulsification method), and the like. In addition to the polyol and polyisocyanate, an anionic emulsifier, a carboxylic acid such as dimethylpropionic acid (DMPA), a cationic or nonionic internal emulsifier can be added.

  The urethane resin fine particles may be used as a urethane emulsion dispersed in water or a water-containing solvent, or may be used as powdered resin fine particles not containing water or a water-containing solvent.

When using a urethane emulsion dispersed in water or a water-containing solvent, it can be used by kneading it as it is with a hydraulic component. In addition, for the purpose of adjusting the viscosity and the TI value, water may be added as necessary.
In the case of using powdery resin fine particles not containing water or a water-containing solvent, kneading is performed after adding water in order to produce a homogeneous slurry.

  In the urethane emulsion dispersed in water or a water-containing solvent, the content of the urethane resin fine particles contained in the emulsion can be appropriately selected, but is 20 to 70% by mass based on the total amount of the emulsion. Preferably, it is more preferable in it being 30-50 mass%.

  The acrylic resin fine particles and the urethane resin fine particles are preferably used by blending urethane resin fine particles in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the acrylic resin fine particles. When the blending amount of the urethane resin fine particles exceeds 20 parts by mass, the effects of improving the strength and reducing the stickiness are recognized, but the elongation tends to be small.

  As said polymer cement composition, with respect to 100 mass parts of acrylic resin fine particles, 1-20 mass parts of urethane resin fine particles, preferably 15-175 mass parts, more preferably 20-100 mass parts of a hydraulic component. Part, more preferably 22 to 90 parts by weight, particularly preferably 23 to 70 parts by weight. When the content of the hydraulic component is larger than the above range, the pot life of the resulting polymer cement composition tends to be short, and the viscosity tends to increase and the coatability tends to decrease. There is a tendency to slow down and the strength of the coating film to decrease.

  As the above-mentioned polymer cement composition, with respect to 100 parts by mass of acrylic resin fine particles, 1 to 20 parts by mass of urethane resin fine particles, and preferably 16 to 350 parts by mass of a hydraulic component and a filler, More preferably 20 to 330 parts by mass, more preferably 22 to 300 parts by mass, more preferably 23 to 270 parts by mass, more preferably 80 to 250 parts by mass, and particularly preferably 150 to 230 parts by mass are suitably used. be able to. When the total amount of the hydraulic component and the filler is larger than the above range, the resulting polymer cement composition tends to have a high viscosity, resulting in a decrease in coating properties and insufficient elongation of the coating film. If it is smaller than the above range, the coating film strength tends to decrease and the stickiness of the coating film tends to increase.

  Here, when an acrylic emulsion is used as the acrylic resin fine particles, the mass of the “acrylic resin fine particles” indicates the mass of the solid content in the acrylic emulsion, and the urethane emulsion is used as the urethane resin fine particles. In this case, the mass of the “urethane resin fine particles” indicates the mass of the solid content in the urethane emulsion.

  Furthermore, you may add a small amount of crosslinking agents, a thickener, etc. to the above-mentioned polymer cement composition. As a crosslinking agent, water-soluble polycarbodiimide resin, isocyanate resin, etc. can be used, for example.

As the thickener, a water-soluble polymer such as polyether, urethane, or acrylic, a cellulose or protein-based thickener can be used, and a water-soluble polyurethane thickener is particularly preferably used. Can do. Commercially available products such as trade names Adecanol UH-420, UH-438, UH-472 (Asahi Denka Kogyo Co., Ltd.) can be used as the water-soluble polyurethane thickener.
The addition amount of the thickener can be appropriately adjusted within a range not impairing the properties of the present invention, and is 0.05 to 1.0 part by mass, and further 0.1 to 100 parts by mass of the polymer cement composition. It is preferable to contain -0.7 mass part, especially 0.2-0.5 mass part.

  To the polymer cement composition, a setting regulator such as a setting retarder and a setting accelerator, a fluidizing agent, an antifoaming agent, and the like can be added as long as the characteristics of the present invention are not impaired.

According to the polymer cement composition described above, a cured product having all the following characteristics can be obtained.
1) The tensile strength is preferably 0.8 N / mm ² or more and the tensile product is higher than 40 N / mm.
2) The elongation change rate after immersion is preferably 200% or less.
3) There is almost no difference in the color of the coating film before and after immersion.
4) There is almost no stickiness.

The mortar of the present invention is obtained by kneading the above-mentioned polymer cement composition in which the filler is sand and water.
As an example of the method for producing the mortar, a predetermined amount of an acrylic emulsion and a urethane emulsion are weighed in a stirring vessel, and water containing a predetermined amount of alumina cement is stirred with stirring a mixture of the acrylic emulsion and the urethane emulsion. Add stiff ingredients, sands, and, if necessary, setting modifiers such as setting retarders and setting accelerators, fluidizers, antifoaming agents, crosslinking agents, thickeners, etc., and stir and mix for several minutes (kneading) And a method of producing a slurry-like mortar having a predetermined viscosity by further adding water as necessary.
In addition, as another example of the method for producing the mortar, a predetermined amount of each component of the polymer cement composition (the filler is sand) is added to a stirring vessel and further condensed if necessary. Add retarder, setting accelerator for setting accelerator, fluidizer, antifoaming agent, cross-linking agent, thickener, etc., stir and mix (knead) for several minutes with a stirrer, and add water as necessary The method of adding and manufacturing the slurry-like mortar which has predetermined | prescribed viscosity is mentioned.
Hydraulic components, sands, thickeners or additives including alumina cement may be added singly or may be added in advance with other several kinds, and the order of addition is particularly selected. Absent. Moreover, what has a stirring function, such as a general solid-liquid stirrer, can be used for a stirrer without a problem. When adding water, it is preferable to add so that a homogeneous slurry may be obtained so that a component may not isolate | separate.

  The mortar (or polymer cement composition) of the present invention can be used by coating it on the surface of an object to be coated by a general method using a roller, a trowel, spraying (spray, etc.) and the like. The structure coated with mortar can be obtained by curing the mortar coated on the surface of the object to be coated. After drying the mortar, the same operation can be repeated to form a plurality of mortar layers. In addition, when constructing a structure in which the mesh is sandwiched between mortar layers for construction on the rooftop, etc., after drying the mortar, place the mesh on it and then apply the mortar on the mesh to fix the mesh. You may employ | adopt the construction method which adds a process. Furthermore, it is also possible to finish by forming a protective layer in which another composition or protective coating is applied and dried on the outermost layer.

As a method of applying mortar (or polymer cement composition) to the surface of an object to be coated, for example,
1) Wash the surface of the object to be coated, apply an emulsion if necessary, and further dry the emulsion if necessary.
2) Apply the mortar to the surface of the object to be coated in 1) by a known coating method such as spraying, glazing, or roller coating. The method of using, and also making it dry as needed is mentioned.
Thereby, the mortar can be applied to the surface of the object to be coated, and a structure in which the surface of the object to be coated is coated with mortar can be obtained.

The mortar of the present invention can be used as a waterproofing material such as a veranda, a rooftop, a roof, a pillar, and a water tank, a finishing material, a base conditioner, and the like.
The mortar of the present invention can be used for waterproofing applications such as concrete structures, and can be used by coating on the surface of an object to be coated such as concrete.

  Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited by the following examples.

1. Evaluation of cured mortar 1) Tensile strength and elongation rate A PET film is laid on a glass plate, and mortar is applied in an amount of 1.8 kg / m ^{2 on} the condition of 23 ± 3 ° C. and humidity 60 ± 5%. Then, after curing for 7 days, the coating film is peeled off, and further cured at 23 ± 3 ° C. and humidity of 60 ± 5% for 6 days to obtain a mortar sheet. After preparing the test body according to the evaluation test, it is further cured for one day in a state of 23 ± 3 ° C. and humidity of 60 ± 5%.
For the measurement of tensile strength and elongation, a test piece (a) was prepared from a mortar sheet using a dumbbell No. 2 type, and the autograph (manufactured by Toyo Baldwin Corporation) TENSILON / UTM-I-2500) is used at a distance between chucks of 60 mm and a pulling speed of 200 mm / min. The measurement is performed using three samples. The elongation (%) is calculated according to the following formula (1). The tensile strength and elongation are the average values of three measurement samples.

（但し、Ａ：チャック間の試料の長さ（６０ｍｍ）、Ｂ：破断時のチャック間の試料の長さ（破断時のチャック間距離）。標線間伸びの場合はＡ：２０ｍｍ、Ｂ：破断時の標線間の試料の長さとして計算する。）

(However, A: sample length between chucks (60 mm), B: length of sample between chucks at break (distance between chucks at break). A: 20 mm when extending between marked lines, B: Calculated as the length of the sample between the marked lines at break.)

2. Evaluation of water resistance 1) Tensile strength and elongation retention rate Three test pieces (a) of the mortar sheet of 1.1) above were immersed in water at 23 ± 3 ° C. for 24 hours, and these test pieces were taken out of the water. The water droplets are thoroughly wiped off (this is referred to as a test piece (a ′)), and mechanical evaluation (tensile strength and elongation) is immediately performed. The tensile strength and elongation after immersion are the average values of three measurement samples. The retention rate is calculated according to the following formula (2) and formula (3).

2) Tensile product The product of the value of tensile strength and the value of elongation between marked lines obtained by the method of 1.1) is calculated as the tensile product.

3) Discoloration of the coating film with water A primer (a solution obtained by adding water to an acrylic emulsion and diluting 10 times) in advance is applied to a 5 mm thick slate plate (300 × 300 mm) in an amount of 0.4 kg / m ^2. . The mortar is applied to the primer-coated surface of this slate plate in an amount of 1.8 kg / m ² and cured for 13 days under the conditions of 23 ± 3 ° C. and humidity 60 ± 5% to obtain a specimen (b).
Thereafter, the specimen C is immersed in water at 20 ± 3 ° C. for 24 hours. Then, remove the specimen (b) from the water, wipe off the water droplets (this is designated as the specimen (b ′)), and immediately observe the color change between the specimen C and the specimen (b ′). The following evaluation is performed.
Evaluation: ：: Almost no difference, ○: Slightly conspicuous, Δ: Slightly conspicuous, ×: Conspicuous

4) Sticky evaluation (evaluation by walking)
A polymer cement composition is applied to the concrete surface with a commercially available general-purpose roller [Otsuka Brush Manufacturing Co., Ltd., Wooler B] in an amount of 0.9 kg / m ² to obtain a specimen C. The coating film applied to Specimen C was cured under conditions of a temperature of 20 ± 3 ° C. and a humidity of 65 ± 5% for 4 hours, and walking on the cured coating surface with safety shoes (manufactured by Simon Co., Ltd.). Then, the tackiness of the paint surface felt on the sole is evaluated. The person who walked is about 60 kg in weight. The sticky evaluation criteria are shown below.
Evaluation: ◎: Not felt at all, ○: Little felt, △: Strong stickiness and resistance to walking, ×: Strong stickiness and unable to walk.

[Examples 1 to 3, Comparative Example 1]
(1) As raw materials, the following were used.
Alumina cement: Blaine specific surface area 3300 cm ² / g, monocalcium aluminate content 45% by mass.
Silica sand: No. 7 silica sand (commercially available).
-Thickener: Water-soluble urethane thickener (UH472, manufactured by Asahi Denka).
Acrylic emulsion: glass transition temperature = −43 ° C., solid content concentration = 54 mass%
-Urethane emulsion: Polycarbonate-polyether polyurethane dispersion (ETERRNACOLL UW-E2050-E, manufactured by Ube Industries, Ltd.), solid content = 35% by mass

(2) Preparation of mortar (Examples 1 and 2, Comparative Examples 1 and 2)
The mortar was prepared by using a polymer cement composition comprising the above acrylic emulsion, urethane emulsion, alumina cement, silica sand, and thickener.
Add a total of 1250 g of acrylic emulsion, urethane emulsion, alumina cement, silica sand, and thickener to a 2 L plastic container, mix (knead) for 3 minutes under a condition of 1300 rpm using a 0.15 KW stirrer, and slurry A mortar was obtained.
About the obtained mortar, evaluation of a hardening body and evaluation of water resistance were performed by the above-mentioned method. The results are shown in Table 2.

In Examples 1 to 3, as compared with Comparative Example 1, the tensile strength, the retention rate, and the anti-long product were improved, the stickiness was reduced, and the rate of change in elongation due to immersion was kept low. In particular, Examples 1 and 2 have an elongation rate of 100% or more, a tensile strength of 1.0 or more, a tensile product of 50 or more, and excellent properties as a mortar (polymer cement composition). I understand.

Claims (7)

  A polymer cement composition comprising a hydraulic component containing alumina cement, a filler, acrylic resin fine particles, and urethane resin fine particles.   2. The polymer cement composition according to claim 1, comprising 1 to 20 parts by mass of urethane resin fine particles with respect to 100 parts by mass of acrylic resin fine particles.   The polymer cement composition according to claim 1 or 2, wherein the glass transition temperature of the acrylic resin in the acrylic resin fine particles is 0 ° C or lower. Urethane resin fine particles are fine particles mainly composed of urethane resin produced by copolymerizing polyisocyanate and polyol,
Polyol is a polycarbonate-polyether block copolymer having two or more hydroxyl groups, a polyester-polyether block copolymer having two or more hydroxyl groups, a polyester having two or more hydroxyl groups, and two or more hydroxyl groups 3. The polymer cement composition according to claim 1, comprising at least one polyol selected from the group consisting of polycarbonates having:   The urethane resin fine particles are contained in an amount of 1 to 20 parts by mass, a hydraulic component is contained in an amount of 15 to 175 parts by mass, and a filler is contained in an amount of 1 to 175 parts by mass with respect to 100 parts by mass of the acrylic resin fine particles. The polymer cement composition according to any one of -4.   The mortar formed by kneading the polymer cement composition according to any one of claims 1 to 5 with water, wherein the filler is sand. A structure formed by applying the polymer cement composition according to any one of claims 1 to 5 or the mortar according to claim 6 to a surface of an object to be coated.