JP2006347797A - Mortar, structure covered with the same and working method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide slurry-like polymer cement capable of suppressing crack occurring in a part different in level and attaining excellent surface smoothness in a work by a coating method such as spraying trowelling, roller-coating or the like of the polymer cement on a working place having the part different in level. <P>SOLUTION: The mortar composition is obtained from a polymer cement composition containing a hydraulic component containing alumina cement, filler, an emulsion and a thickener and has 10,000-25,000 mPas viscosity (6rpm) and thixotropy index (TI) ((viscosity in 6 rpm)/(viscosity in 60 rpm)) of 2.4-3.8. The structure comprising a hardened body of the mortar composition and a base and the working method of the mortar composition are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a slurry-like mortar obtained from a polymer cement composition used for the purpose of imparting waterproofness to a construction part such as a concrete structure, and in particular, to a construction part such as a concrete structure having a step. The present invention relates to a slurry mortar obtained from a polymer cement composition used for the purpose of application, and a structure obtained by coating these mortars. Furthermore, it is related with the construction method of the mortar which constructs these mortars in the construction part which has a level | step difference in order to provide waterproofness.

  In order to provide waterproofing to rooftops, basements, and verandas of concrete structures, polymer cements that contain cement in resin emulsions are being constructed.

  For example, 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. % And glycidyl (meth) acrylate 0.1-5% by weight as essential constituent monomers, and a polymer having a glass transition temperature of −20 ° C. or lower is emulsified and dispersed in water by a cationic or nonionic surfactant. A waterproofing 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 ( A concrete waterproofing composition is disclosed, which contains SiO ₂ content of 90% or more and an average particle size of 0.1 to 0.2 μm) with respect to cement.

  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. A cement composition is disclosed, which is characterized in that the ratio (C / D) of the component (C) and the component (D) is 0.1 to 15.

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

A polymer cement containing a cement and an emulsion is used as a waterproofing material such as a building, a finishing material, and a base conditioning material.
When polymer cement is applied to a floor having a step, cracks may occur at the step portion or smoothness may be impaired.
Therefore, the present invention is a slurry state that suppresses the occurrence of cracks in the stepped portion and is excellent in surface smoothness when the polymer cement is applied to the construction place having a stepped portion by a coating method such as spraying, glazing or roller coating. An object of the present invention is to provide a polymer cement.

The first of the present invention is a mortar obtained from a slurry-like polymer cement composition containing a hydraulic component containing alumina cement, a filler, an emulsion, and a thickener.
The viscosity (6 rpm) of the mortar is in the range of 10,000 to 25000 mPa · s,
The mortar has a TI value (viscosity of 6 rpm / viscosity of 60 rpm) in the range of 2.4 to 3.8.

  The second of the present invention is a structure of mortar and work piece obtained by applying the mortar of the present invention to the work piece surface.

3rd of this invention is the construction method of the mortar of this invention,
The mortar construction method is characterized in that the mortar is applied to a construction portion having a step by spraying, glazing, or roller coating.

The preferable aspect of the mortar of this invention is shown, These can be combined multiplely.
1) The polymer cement composition is based on 100 parts by mass of the polymer solid content of the emulsion.
15 to 175 parts by mass of a hydraulic component.
2) A polymer cement composition contains 15-350 mass parts of total amounts of a hydraulic component and a filler with respect to 100 mass parts of polymer solid content of an emulsion.
3) The thickener is a water-soluble polyurethane thickener.
4) Mortar is for construction of construction parts with steps.
5) The mortar shall be waterproof.
6) The emulsion is an acrylic emulsion, and is an acrylic emulsion having a glass transition temperature of -25 ° C to -60 ° C.
7) The mortar is a homogeneous slurry mortar obtained by kneading the polymer cement composition alone or by adding water to the polymer cement composition.

The mortar obtained from the polymer cement composition of the present invention can be applied to a construction part such as a floor having a step to obtain a cured product having no smoothness at the step part and excellent in smoothness.
The mortar construction method of the present invention is a curing that is excellent in smoothness with no cracks at the stepped portion by applying the mortar of the present invention to the construction portion having a step by spraying, glazing, and roller coating. It is the construction method which can obtain the structure which consists of a thing and a hardened | cured material and a construction part.

The viscosity (6 rpm) of the mortar is in the range of 10,000 to 25000 mPa · s, preferably in the range of 10500 to 24000 mPa · s, more preferably in the range of 11000 to 23000 mPa · s, and more preferably in the range of 11500 to 22000 mPa · s. Yes, particularly preferably in the range of 12000 to 21000 mPa · s,
The TI value of the mortar (viscosity at 6 rpm / viscosity at 60 rpm) is in the range of 2.4 to 3.8, preferably in the range of 2.4 to 3.6, and more preferably in the range of 2.4 to 3. 4 and more preferably in the range of 2.5 to 3.2, and particularly preferably in the range of 2.5 to 3.0, there is no crack at the step portion and excellent smoothness. A cured product can be obtained.

The hydraulic component can contain one or two components selected from Portland cement and gypsum in addition to alumina cement.
The hydraulic component can be preferably used because it contains an alumina cement and has a small discoloration when the cured product is wetted with water and then dried.
The hydraulic component contains alumina cement preferably in an amount of 5% by mass or more, more preferably 15% by mass or more, more preferably 30% by mass or more, and particularly preferably 50% by mass or more in 100% by mass of the hydraulic component. It is preferable to use it.
In particular, it is preferable to use a hydraulic component containing 50% by mass or more of alumina cement in 100% by mass of the hydraulic component because the elongation percentage of the cured product is excellent.

Alumina cement has a potentially rapid hardening property, and gives a cured product excellent in chemical resistance and fire resistance after curing. In addition, due to the presence of blast furnace slag having latent hydraulic properties, a decrease over time in the strength of the cured body, which is a drawback thereof, is also suppressed. Several types of alumina cements having different mineral compositions are known and commercially available, and all of them are 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.

  As the Portland cement, portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, white Portland cement, mixed cement such as blast furnace cement, fly ash cement, and silica cement can be used.

  As for gypsum, each gypsum such as anhydrous and semi-water can be used as one kind or a mixture of two or more kinds regardless of the kind. Gypsum is rapidly hardened and acts as a component for maintaining dimensional stability after curing.

  As filler, 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. Yes, one or more of these fillers can be used. In particular, in the case of silica sand, use of No. 5-7 is preferable.

A known emulsion can be used as the emulsion.
As the emulsion, a synthetic resin emulsion can be used. As the synthetic resin emulsion, a polyvinyl acetate emulsion, a copolymer emulsion of ethylene and vinyl acetate, and a copolymer emulsion of ethylene, vinyl acetate and a (meth) acrylic acid derivative. , Copolymer emulsion of ethylene and (meth) acrylic acid derivative, emulsion of poly (meth) acrylic acid derivative, copolymer emulsion of styrene and (meth) acrylic acid derivative, polychloroprene latex, vinyl acetate and vinyl chloride Copolymer emulsions, styrene / butadiene copolymer emulsions, acrylonitrile / butadiene copolymer emulsions, vinyl acetate and (meth) acrylic acid derivative emulsions, ethylene, styrene, vinyl acetate, (meth) acrylic acid derivatives Na It can be used an emulsion of a synthetic resin comprising at least one of. The (meth) acrylic acid derivative means an acid derivative such as acrylic acid and / or methacrylic acid or an ester thereof, and includes at least one or more of these components.

Any glass transition temperature of the polymer component contained in the emulsion can be used, but is preferably 0 ° C. or lower, more preferably −25 ° C. or lower, more preferably in the range of −25 ° C. to −50 ° C., Particularly preferably, a material having a range of −33 ° C. to −50 ° C. is preferable because it has excellent characteristics even in a low temperature environment, and the glass transition temperature containing a (meth) acrylic acid derivative is 0 ° C. or less, preferably − An emulsion having a temperature of 25 ° C. or lower, particularly preferably in the range of −25 ° C. to −50 ° C., can be preferably used because the elongation percentage of the cured product is excellent.
In particular, the glass transition temperature is preferably 0 ° C. or less, more preferably −25 ° C. or less, more preferably in the range of −25 ° C. to −50 ° C., particularly preferably in the range of −33 ° C. to −50 ° C. An emulsion containing an acid derivative as a main component can be preferably used since the elongation percentage of the cured product is excellent.

The (meth) acrylic acid derivative indicates an acrylic acid derivative and a methacrylic acid derivative. For example, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate 2- Ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and the like.
The emulsion is preferably an acrylic emulsion produced by using one or more (meth) acrylic acid derivatives.

  As the emulsion, one obtained by a known production method can be used. For example, by using a polymerization initiator in the presence of an emulsifier, a polymerizable monomer that is a raw material of a synthetic resin is emulsion-polymerized in water or a hydrous solvent. It can manufacture by the method to do.

As the emulsifier, known ones can be used, and examples thereof include anionic, nonionic, cationic or amphoteric surfactants and protective colloids such as polyvinyl alcohol.
As the polymerization initiator, those capable of radical polymerization in water or a hydrous solvent are preferable, and examples thereof include hydrogen peroxide, peracetic acid, persulfuric acid, water-soluble peroxides such as ammonium salts and sulfates thereof, and salts thereof. be able to. 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 the emulsion can be produced.

  The emulsion contains powdery synthetic resin particles that do not contain water or a water-containing solvent. When powdery synthetic resin particles are used, all components excluding water or water-containing solvent can be made into one package, and the construction site Then it is convenient because it can be used just by adding water.

When an emulsion containing water or a water-containing solvent is used, a mortar can be obtained by kneading the polymer cement composition alone, and water can be added as necessary for the purpose of adjusting the viscosity and TI value. Can be added.
When powdered synthetic resin particles are used as an emulsion, it is impossible to obtain a slurry mortar with the polymer cement composition alone, so a homogeneous slurry is produced by kneading the polymer cement composition and water. can do.

  In the emulsion excluding powdered synthetic resin that does not contain water or a water-containing solvent, the solid content of the polymer contained in the emulsion can be appropriately selected, but 30 to 80 parts by mass is preferable in 100 parts by mass of the emulsion. -60 mass parts is more preferable.

  The polymer cement composition preferably has a hydraulic component of 15 to 175 parts by weight, more preferably 20 to 120 parts by weight, more preferably 22 to 90 parts by weight, particularly preferably 100 parts by weight of the polymer solid content of the emulsion. What contains 23-70 mass parts can be used.

  The polymer cement composition is preferably 15 to 350 parts by mass, more preferably 20 to 330 parts by mass, and more preferably 22 parts of powder containing a hydraulic component and a filler with respect to 100 parts by mass of the polymer solid content of the emulsion. -300 mass parts, More preferably, it contains 23-270 mass parts, More preferably, it contains 80-250 mass parts, Most preferably, what contains 150-230 mass parts can be used.

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

  The polymer cement composition can contain a setting retarder, a setting accelerator for setting accelerator, a fluidizing agent, an antifoaming agent and the like as long as the characteristics of the present invention are not impaired.

As an example of a method for producing mortar, a predetermined amount of emulsion is weighed in a stirring vessel, and a hydraulic component, a filler and a thickener containing a predetermined amount of alumina cement are stirred while stirring the emulsion with a stirrer. Add a set retarder, set accelerator, set agent, fluidizing agent, antifoaming agent, etc., stir and mix for several minutes, add water if necessary, and have a predetermined viscosity and TI value A slurry-like composition can be produced.
As an example of a method for producing mortar, a predetermined amount of each component of a polymer cement composition is added to a container and, if necessary, a setting retarder, a setting accelerator for setting accelerator, a fluidizing agent, an antifoaming agent. A slurry-like composition having a predetermined viscosity and TI value can be produced by adding an agent, stirring and mixing with a stirrer for several minutes, and further adding water as necessary.
Hydraulic components, fillers, thickeners or additives including alumina cement may be added alone, or may be added in advance mixed with several other types, 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 of the present invention can be used by applying to a flat work surface or a work surface having a step by a general method using a roller, a trowel, and spraying (spray etc.). In addition, the mortar of the present invention can be cured to obtain a structure of mortar and work piece. After drying the mortar, the same operation can be repeated to form a plurality of mortar layers. In addition, when the construction is such that the mesh is sandwiched between mortar layers on the rooftop, etc., after drying the mortar composition, place the mesh on it and apply the mortar on the mesh to fix the mesh. You may employ | adopt the construction method which adds the process to do. Furthermore, it is also possible to finish by forming a protective layer by applying and drying another composition or protective coating on the outermost layer.
When the mortar of the present invention is applied to the surface of a workpiece having a step, any step can be selected, but preferably 0.5 to 5 mm, more preferably 0.7 to 4 mm. It is preferably applicable to the case of 0.8 to 2 mm, particularly preferably 0.9 to 1.2 mm.

As a method of constructing mortar on the surface of the work,
1) Wash the surface of the work piece, apply an emulsion if necessary, and further dry the emulsion if necessary.
2) Apply the mortar to the surface of the work piece of 1) above by a known application method such as spraying, glazing, roller coating, etc., and further smoothing the coating surface using cocoons, if necessary. Furthermore, by drying as necessary,
Mortar can be applied to the work surface,
A structure of a cured product layer of mortar and a work can be obtained.

The mortar of the present invention can be used with a waterproofing material such as a veranda, a rooftop, a roof, a pillar, and a water tank, a finishing material, and a base conditioning material.
The mortar of the present invention can be used for waterproofing applications such as concrete structures, and can be applied to the surface of a concrete work piece.

  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. Viscosity Measurement Method Under an environment of temperature 20 ° C. and humidity 65%, first, in a 2 L plastic container, emulsion, alumina cement, Portland cement, gypsum, silica sand and thickener as polymer cement composition shown in Table 1 It is added at the blending ratio shown in Table 1 (total 1250 g) and mixed for 3 minutes under a condition of 1300 rpm using a 0.15 KW stirrer to obtain a homogeneous slurry mortar. Immediately thereafter, a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.) and rotor No. 4 is used to quickly fill a 200 mL cup with about 250 g of mortar. Immediately after filling, the viscosity is set to 6 rpm and 1 minute after rotating the rotor. Further, the setting is changed to 60 rpm and the rotor is set to 1 minute after rotating the rotor. Measure the viscosity.
The TI value is a value obtained by dividing the viscosity value of 6 rpm obtained above by the viscosity value of 60 rpm.
TI value = (viscosity value at 6 rpm) / (viscosity value at 60 rpm)

2. Workability evaluation 1) Evaluation method of solder wave traces Two spacers 1 having the shape shown in FIG. 1 are prepared. The spacer 1 has a step of 1 mm at the center, and the higher surface of the spacer 1 is the A surface and the lower surface is the B surface.
On the surface of the slate plate 2 shown in FIG. 2, 0.4 kg / m ² of a primer (a solution obtained by adding water to the emulsion and diluting 10 times using the same emulsion as used in each example or comparative example). Apply in an amount of and dry. After that, on the primer application surface of the slate plate 2, the two spacers (1a, 1b) created in FIG. 1 are parallel to each other in the same direction at an interval of about 100 mm with the stepped side up as shown in FIG. Put the mortar between the A side of the spacer 1a and the A side of the spacer 1b, and level the mortar 3 in the direction of the arrow 4 (from the A side to the B side) with a trowel. After drying, the conspicuousness of the step in the vicinity of the 1 mm step is visually observed, and the following evaluation is performed. The slate plate 2 (performed at a temperature of 20 ° C. and a humidity of 65%) has a shape of 5 mm thickness × 300 mm × 300 mm.
Evaluation: ○: Steps are hardly noticeable, Δ: Steps are slightly noticeable, ×: Steps are noticeable.
2) Crack evaluation method Primer (previously using the same emulsion as in each example and comparative example, and adding 10 times to the emulsion and diluting the emulsion 10 times) on a 5 mm thick slate plate (300 x 300 mm), 0.4 kg / It is applied in an amount of m ^2. After drying, the mortar is leveled with a trowel so that the mortar has a thickness of 2 mm on the primer-coated surface of the slate plate. Immediately after that, it is allowed to stand with an inclination of 10%, and the presence or absence of cracks on the surface of the coated film after curing is confirmed. (Performed under conditions of temperature 20 ° C and humidity 65%)
-Evaluation: (circle): There is no crack, x: There is a crack.

3. Evaluation of cured products 1) Evaluation method of 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 glass plate, under conditions of 20 ± 3 ° C. and humidity 65 ± 5%. After curing for 2 days, the coating film is peeled off, and further cured for 26 days in a state of 20 ± 3 ° C. and humidity of 65 ± 5% to obtain a polymer cement sheet (test body A).
For the measurement of the elongation rate, a test piece was prepared from the specimen A using a dumbbell No. 1 type, and the autograph (TENSILON / UTM-, manufactured by Toyo Baldwin Co., Ltd.) was used under the conditions of a measurement temperature of 20 ° C. and a humidity of 60%. I-2500), and a distance between chucks of 80 mm and a tensile speed of 200 mm / min. The elongation rate (%) is calculated according to Equation (1).

2) Elongation evaluation method by ground crack follow-up test Using 5mm thick slate plate (50x150mm) with a notch in the center, primer (same emulsion as each example and comparative example) is used in advance and water is added to the emulsion. 10 times diluted liquid) is applied in an amount of 0.4 kg / m ² . A mortar is applied to the primer-coated surface of this slate plate in an amount of 1.8 kg / m ² and cured for 28 days under the conditions of 20 ± 3 ° C. and humidity of 65 ± 5% to obtain a specimen B.
The elongation by the base crack follow-up test is measured by using an autograph (manufactured by Toyo Baldwin Co., Ltd., TENSILON / UTM-I-2500) under the conditions of a measurement temperature of −10 ° C. and a humidity of 60%. , Under the conditions of a tensile speed of 5 mm / min. The elongation when defects such as cracks occur in the specimen B (coating film) by visual observation is measured, and the elongation is defined as the base crack followability.

3) Lightness and Hue Evaluation Method A primer (a solution obtained by diluting the emulsion 10 times by adding water to the emulsion in advance using the same emulsion as in each of the Examples and Comparative Examples) on a 5 mm thick slate plate (300 × 300 mm) Apply in an amount of 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 3 days under the conditions of 20 ± 3 ° C. and humidity of 65 ± 5% to obtain a specimen C.
For the brightness and hue, the surface of the specimen C on which the mortar was applied was measured using a handy color difference meter (NR-3000, manufactured by Nippon Denshoku Industries Co., Ltd.) (light source: C / 2 °), brightness L ₁ ^* , Hue a ₁ ^* and hue b ₁ ^* are measured and used as the brightness and hue at the time of drying.
Thereafter, about 5 ml of water droplets at 20 ± 3 ° C. are dropped on the coating surface of the specimen C, and then left to stand at 20 ± 3 ° C. and humidity of 65 ± 5% until the water droplets are dried. After drying, the lightness L ₂ ^* , the hue a ₂ ^* , and the hue b ₂ ^* are measured using the handy color difference meter, and are set as the brightness and hue when the water-wetting part is dried. The color difference ΔE and lightness difference ΔL ^* between the time of drying and the drying of the wetted part are calculated by the following mathematical formulas (2) and (3). The color when the coating film is dried and the color when the coating film is dried after being wetted with water are visually observed, and the following evaluation is performed.
Evaluation: ○: Almost no difference, Δ: A little noticeable, ×: A difference is noticeable.

(Production Example 1: Production of Emulsion A)
In advance, 446 parts of ion-exchanged water, 14 parts of polyoxyethylene nonylphenyl ether (manufactured by Kao Corporation, Emulgen 935), 14 parts of polyoxyethylene alkyl ether sulfate ester (Daiichi Kogyo Seiyaku Co., Ltd., Aqualon KH-10) , 322 parts of methyl methacrylate, 868 parts of 2-ethylhexyl acrylate, 210 parts of n-butyl acrylate, 60 parts of 2-hydroxyethyl methacrylate, 7 parts of methacrylic acid, and 7 parts of acrylamide were prepared to prepare a monomer emulsified mixture.
In a 3 L reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping device and nitrogen gas introduction tube, 620 parts of ion-exchanged water, sodium dodecylbenzenesulfonate (manufactured by Kao Corporation, Neoperex G-65) 2.8 The portion was charged, replaced with nitrogen gas, and heated while stirring until the internal temperature reached 78 ° C. 0.9% by weight of the total amount of the previously prepared monomer emulsified mixture was weighed and added to the reaction vessel. After 5 minutes, 18 parts of 10% organic peroxide and 18 parts of 2% reducing agent were added for initial polymerization. At the same temperature, the remaining monomer emulsified mixture and 46 parts of 2% reducing agent were added dropwise at the same time, and the polymerization reaction was carried out for 5 hours. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining 78 ° C. Thereafter, the temperature was lowered to 70 ° C., and the polymerization of the unreacted monomer was completed using an organic peroxide and a reducing agent. Thereafter, the temperature was lowered to room temperature, an antifoaming agent, an antiseptic, a light stabilizer, and an ultraviolet absorber were added, and the pH and nonvolatile content were adjusted with ammonia water and ion-exchanged water to obtain an acrylic emulsion A.
The acrylic emulsion A has a glass transition temperature of −40 ° C. obtained from about 23% by weight of methyl methacrylate, about 62% by weight of 2-ethylhexyl acrylate, and about 15% by weight of n-butyl acrylate.

(Production Example 2: Production of Emulsion B)
In advance, 557 parts of ion-exchanged water, 14 parts of polyoxyethylene nonylphenyl ether (manufactured by Kao Corporation, Emulgen 935), 14 parts of polyoxyethylene alkyl ether sulfate ester (Daiichi Kogyo Seiyaku Co., Ltd., Aqualon KH-10) Then, 434 parts of styrene, 594 parts of 2-ethylhexyl acrylate, 462 parts of n-butyl acrylate, 60 parts of 2-hydroxyethyl methacrylate, 7 parts of methacrylic acid and 7 parts of acrylamide were weighed to prepare a monomer emulsified mixture.
In a 3 L reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping device and nitrogen gas introduction tube, 590 parts of ion-exchanged water, sodium dodecylbenzenesulfonate (manufactured by Kao Corporation, Neopelex G-65) 2.8 The portion was charged, replaced with nitrogen gas, and heated while stirring until the internal temperature reached 78 ° C. The previously prepared monomer emulsified mixed solution was weighed 1.4% by weight and added to the reaction vessel. After 5 minutes, 18 parts of 10% organic peroxide and 18 parts of 2% reducing agent were added for initial polymerization. At the same temperature, the remaining monomer emulsified mixture and 46 parts of 2% reducing agent were added dropwise at the same time, and the polymerization reaction was carried out for 5 hours. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining 78 ° C. Thereafter, the temperature was lowered to 70 ° C., and the polymerization of the unreacted monomer was completed using an organic peroxide and a reducing agent. Thereafter, the temperature was lowered to room temperature, an antifoaming agent, an antiseptic, a light stabilizer, and an ultraviolet absorber were added, and the pH and nonvolatile content were adjusted with ammonia water and ion-exchanged water to obtain an acrylic emulsion B.
Acrylic emulsion B has a glass transition temperature of −30 ° C. obtained from about 31% by weight of styrene, about 36% by weight of 2-ethylhexyl acrylate, and about 33% by weight of n-butyl acrylate.

(Production Example 3: Production of Emulsion C)
In advance, 420 parts of ion-exchange water, 28 parts of polyoxyethylene nonylphenyl ether (manufactured by Kao Corporation, Emulgen 935), 322 parts of methyl methacrylate, 616 parts of 2-ethylhexyl acrylate, 462 parts of n-butyl acrylate, 2-hydroxyethyl 60 parts of methacrylate, 7 parts of methacrylic acid and 7 parts of acrylamide were weighed to prepare a monomer emulsified mixture.
In a 3 L reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping device and nitrogen gas introduction tube, 560 parts of ion-exchanged water, sodium dodecylbenzenesulfonate (manufactured by Kao Corporation, Neoperex G-65) 2.8 The portion was charged, replaced with nitrogen gas, and heated while stirring until the internal temperature reached 78 ° C. The previously prepared monomer emulsified mixture was weighed out 0.7% by weight and added to the reaction vessel. After 5 minutes, 14 parts of 5% sodium persulfate was added to conduct initial polymerization. At the same temperature, the remaining monomer emulsified mixture and 42 parts of 5% sodium persulfate were added dropwise at the same time to conduct a polymerization reaction for 5 hours. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining 78 ° C. Thereafter, the temperature was lowered to 70 ° C., and the polymerization of the unreacted monomer was completed using an organic peroxide and a reducing agent. Thereafter, the temperature was lowered to room temperature, an antifoaming agent, an antiseptic, a light stabilizer, and an ultraviolet absorber were added, and the pH and nonvolatile content were adjusted with ammonia water and ion-exchanged water to obtain an acrylic emulsion C.
The acrylic emulsion C has a glass transition temperature of −40 ° C. obtained from about 23% by weight of methyl methacrylate, about 44% by weight of 2-ethylhexyl acrylate, and about 33% by weight of n-butyl acrylate.

(Evaluation of glass transition temperature)
An appropriate amount of the emulsion was dropped on a glass plate, dried at 60 ° C. for 16 hours, and the resulting dried coating film having a mass in the range of 9.5 to 10.5 mg was converted into a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) is used to measure the glass transition temperature.
The DSC measurement conditions were as follows: room temperature was raised from 150 ° C. over 10 minutes, held at 150 ° C. for 10 minutes, lowered to a temperature 50 ° C. lower than the Tg of the sample obtained by calculation, and again raised to 150 ° C. over 10 minutes. When warming, the first Tg is measured. Next, when the temperature is lowered to 50 ° C. lower than the Tg measured in the first time, the second Tg is measured, and the second Tg value is defined as the glass transition temperature.

[Examples 1-7, Comparative Examples 1-9]
(1) The following materials were used.
Alumina cement: Blaine specific surface area 3300 cm ² / g, monocalcium aluminate content 45% by mass.
Portland cement: Early-strength Portland cement, Blaine specific surface area of 4500 cm ² / g.
Gypsum: Type II anhydrous gypsum, Blaine specific surface area 3520 cm ² / g (manufactured by Central Glass Co., Ltd.).
Silica sand: No. 7 silica sand (commercially available).
-Thickener A: Aqueous urethane thickener (UH472, manufactured by Asahi Denka Co.).
-Thickener B: Aqueous urethane thickener (UH438, manufactured by Asahi Denka Co.).
-Thickener C: Methylcellulose thickener (Marporose, manufactured by Matsumoto Yushi Co., Ltd.).

(2) Preparation of mortar To a 2 L plastic container, the emulsion, alumina cement, Portland cement, gypsum, silica sand and thickener shown in Table 1 were added at the blending ratio shown in Table 1 (total 1250 g), and a 0.15 KW stirrer was added. Used and mixed for 3 minutes under the condition of 1300 rpm to obtain a slurry mortar.
The obtained mortar was evaluated for viscosity (6 rpm and 60 rpm), trowel traces and cracks, and the cured mortar was evaluated for elongation rate and elongation of base crack followability. Table 2 shows the results.
In the blending ratio in Table 1, the blending amount of the emulsion is the polymer solid content of the emulsion.

1) Comparing Example 1 and Example 5 due to the difference in hydraulic component, Example 1 containing a large amount of alumina cement is superior in elongation of the cured product.
2) Comparing Example 2 and Example 6 due to the difference in emulsion, Example 6 containing styrene has a large elongation at 20 ° C. of the cured product but a small elongation at −10 ° C. Is superior in low-temperature characteristics.

  The brightness and hue at the time of drying of the cured products obtained in Example 2, Example 5 and Comparative Example 2 were observed by visual comparison with the color when the coating film was wet-dried, and the result Is shown in Table 3. In Comparative Example 2 containing no alumina cement, discoloration of the cured product dried after wetting with water was large.

The perspective view of the spacer for evaluation of a solder wave trace is shown in model. The top view of the member for evaluation of a solder wave trace is shown as a model.

Explanation of symbols

1, 1a, 1b: spacer, 2: slate, 3: mortar.

Claims (7)

A mortar obtained from a polymer cement composition comprising a hydraulic component comprising alumina cement, a filler, an emulsion, and a thickener;
The viscosity (6 rpm) of the mortar is in the range of 10,000 to 25000 mPa · s,
A mortar characterized by having a TI value (viscosity of 6 rpm / viscosity of 60 rpm) in the range of 2.4 to 3.8. The polymer cement composition is based on 100 parts by mass of the polymer solid content of the emulsion.
The mortar according to claim 1, comprising 15 to 175 parts by mass of a hydraulic component. The polymer cement composition is
The mortar according to claim 1 or 2, wherein the total amount of the hydraulic component and the filler is 15 to 350 parts by mass with respect to 100 parts by mass of the polymer solid content of the emulsion.   The mortar according to any one of claims 1 to 3, wherein the thickener is a water-soluble polyurethane thickener.   The mortar according to any one of claims 1 to 4, wherein the mortar is for construction of a construction part having a step.   The structure of the mortar and to-be-processed object obtained by constructing the mortar of any one of Claims 1-5 on the to-be-processed object surface. It is the construction method of the mortar of any one of Claims 1-5,
A mortar construction method, characterized in that mortar is applied to a construction part having a step by spraying, glazing, or roller coating.

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