JP4345511B2 - Polymer cement composition for waterproofing - Google Patents

Description

  The present invention relates to a waterproof polymer cement composition excellent in workability and weather resistance, which is used for the purpose of imparting waterproofness to a construction object when constructing a concrete structure or the like.

  A polymer cement composition is applied to the roof, underground, veranda, etc. of a concrete structure in order to impart waterproofness.

For example, Patent Document 1 discloses a cementitious uncured composition with improved bending strength, comprising 100 parts by weight of alumina cement, 200 to 500 parts by weight of slag, meteorite or calcium carbonate, and a water-dispersible polymer. Yes.
Patent Document 2 discloses a nonionic surface active as a coating composition for forming a waterproof film layer that has excellent elongation-strength, water resistance, alkali resistance, etc., and can seal cracks by absorbing and swelling water leakage. A coating composition for a concrete structure is disclosed in which an ethylene-vinyl acetate copolymer resin emulsion obtained using an agent as an emulsifier is a main component, and an acrylic resin emulsion and lime aluminate or further cinnabar sand are blended therein.

Japanese Patent Laid-Open No. 04-240145 JP 09-070661 A

  An object of the present invention is to provide a waterproof polymer cement composition in which the above-mentioned drawbacks of a conventionally used waterproof polymer cement composition are improved. Specifically, when construction is performed, even with roller construction, skill is not required and workability is good, and in terms of characteristics, the finish of the coating film is excellent without causing cornering, material separation, and skinning. An object of the present invention is to provide a waterproof polymer cement composition that provides a structure having excellent water resistance, adhesion, elongation at low temperatures, and weather resistance.

The present invention is a waterproof polymer cement composition comprising an alumina cement, an emulsion and a phyllosilicate mineral,
The emulsion contains an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion. The solid content of the acrylic polymer emulsion is 3 to 20 parts by mass with respect to 100 parts by mass of the solid content of the ethylene-vinyl acetate copolymer emulsion. It is providing the polymer cement composition for waterproofing characterized by including by the ratio.
The solids content of the emulsion is the polymer solids content of the emulsion.

Preferred embodiments of the waterproof polymer cement composition of the present invention are shown below.
In the polymer cement composition for waterproofing, 20 to 80 parts by mass of alumina cement and phyllosilicate with respect to 100 parts by mass of emulsion solids (a mixture of solids of ethylene-vinyl acetate copolymer emulsion and acrylic polymer emulsion). It is preferable that 4-80 mass parts of acid salt mineral is included.
In the polymer cement composition for waterproofing, 20 to 80 parts by mass of alumina cement, phyllosilicate with respect to 100 parts by mass of emulsion solids (a mixture of solids of ethylene-vinyl acetate copolymer emulsion and acrylic polymer emulsion) It is preferable that 4-80 mass parts of silicate mineral and 20-240 mass parts of silica sand are included.
The ethylene-vinyl acetate copolymer emulsion is preferably an ethylene vinyl acetate copolymer emulsion (PVA-EVA emulsion) using polyvinyl alcohol as a protective colloid.

  The waterproof polymer cement composition of the present invention not only has excellent workability but also provides a waterproof film layer with excellent coating film properties and weather resistance. Therefore, the utility value is high in imparting waterproofness to the concrete structure.

  The emulsion contains at least two kinds of emulsions of an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion, and can contain other emulsions as long as the properties are not affected.

  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 for 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 the water-containing solvent can be made into one package, and the construction site Then, it can be used simply by adding water.

As the ethylene-vinyl acetate copolymer emulsion, a known emulsion obtained by copolymerizing ethylene and vinyl acetate can be used.
The glass transition temperature of the solid content of the ethylene-vinyl acetate copolymer emulsion can be appropriately selected and used, but the glass transition temperature of the solid content of the ethylene-vinyl acetate copolymer emulsion is preferably 10 ° C. or less, More preferably it is 0 ° C. or lower, or preferably −50 to 10 ° C., more preferably −40 to 0 ° C., in order to ensure elongation and base followability.
As the ethylene-vinyl acetate copolymer emulsion, those using water-soluble polymers such as polyvinyl alcohol and cellulose derivatives as emulsifiers and protective colloids can be preferably used. In particular, the ethylene-vinyl acetate copolymer emulsion is preferably one using polyvinyl alcohol as a protective colloid.
In the polymer component of the ethylene-vinyl acetate copolymer emulsion, the vinyl acetate content is preferably 30 to 90% by mass, more preferably 50 to 90% by mass, and particularly preferably 60 to 86% by mass.
The content of the ethylene vinyl acetate copolymer component in the ethylene-vinyl acetate copolymer emulsion is preferably 40 to 65% by mass, more preferably 45 to 60% by mass, and particularly preferably 47 to 60% by mass.

  In particular, it is preferable to use an ethylene vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid. The workability of the waterproof polymer cement composition may be affected by the protective colloid species used in the ethylene-vinyl acetate copolymer emulsion. For example, in the case of methyl cellulose, hydroxyethyl cellulose, etc., the kneadability is poor depending on the alumina cement species to be combined. May be. On the other hand, an ethylene-vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid (hereinafter referred to as a PVA-EVA emulsion) is preferable because it hardly affects the kneadability due to the alumina cement type.

As the acrylic polymer emulsion, one kind of (meth) acrylate compound such as alkyl (meth) acrylate such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. Alternatively, those obtained by polymerizing two or more kinds and those obtained by copolymerization with vinyl compounds such as styrene, vinyl acetate, vinylidene chloride and the like that can be copolymerized with these monomers can be used. (Meth) acrylate means methacrylate and acrylate.
The acrylic polymer emulsion is preferable because the polymer component contained in the emulsion is excellent in elongation by using a polymer that is not crosslinked, more preferably a polymer that is not crosslinked within or between polymers.

For the acrylic polymer emulsion, known emulsifiers and protective colloids can be used, for example, water-soluble polymers such as polyvinyl alcohol and cellulose derivatives, emulsifiers and protective colloids such as nonionic surfactants and ionic surfactants. Can be used.
As the acrylic resin emulsion, a known emulsion can be used, and the content of the acrylic resin component is not particularly limited.
The glass transition temperature of the solid content of the acrylic polymer emulsion can be appropriately selected and used, but the glass transition temperature of the solid content of the acrylic polymer emulsion is preferably 10 ° C. or less, more preferably 0 ° C. or less. Or preferably −50 to 10 ° C., more preferably −40 to 0 ° C., in order to ensure elongation and base followability.

  By mixing the acrylic polymer emulsion with an ethylene vinyl acetate copolymer emulsion such as PVA-EVA emulsion, the elongation of the polymer cement composition and the sliding of the roller during roller application are improved, and the workability is improved. Elongation at low temperature increases and weather resistance is greatly improved. Improvement in workability is achieved by mixing an acrylic polymer emulsion having a particle size of about 0.1 μm with an ethylene vinyl acetate copolymer emulsion such as PVA-EVA emulsion having a particle size of about 0.5 μm alone. It is speculated that this is due to the effect and the absence of thickening materials in the protective colloid. In addition, the improvement in weather resistance is due to the fact that the acrylic polymer emulsion has a larger elongation and is more stretchable than the ethylene vinyl acetate copolymer emulsion such as PVA-EVA emulsion. It is considered that deterioration over time was greatly improved by using a mixed system of a specific ratio rather than the polymerized emulsion alone.

  Weather resistance is very important for waterproofing materials used for rooftops of concrete structures and the like, and in particular, it is required to follow the base crack. In general, cracks in concrete are subject to seasonal variation, and cracks of 0.2 mm in the summer expand to a maximum of about 0.9 mm in winter. As a result, a defect or breakage occurs, and the role of the waterproof material is not fulfilled. Furthermore, it is very difficult to maintain the base crack followability for a long period of time due to deterioration due to aging, but by mixing an acrylic polymer emulsion with an ethylene vinyl acetate copolymer emulsion such as PVA-EVA emulsion, It became possible to maintain the ground crack followability of 0.9 mm or more, preferably 1.2 mm or more, more preferably 1.5 mm or more, and particularly preferably 1.8 mm or more.

  The blending amount of the acrylic polymer emulsion is 3 to 20 parts by mass, preferably 4 to 20 parts by mass in terms of solid content of the acrylic polymer emulsion with respect to 100 parts by mass of the solid content of the ethylene vinyl acetate copolymer emulsion. It is preferably 5 to 20 parts by mass, particularly preferably 6 to 20 parts by mass. When the blending ratio of the acrylic polymer emulsion is less than 3 parts by mass, the effect of mixing with the ethylene-vinyl acetate copolymer emulsion is not sufficiently exhibited. There is a risk that it will cause quick cornering and a decrease in workability.

Alumina cement can be used without any problem as alumina cement for any use such as refractory, civil engineering, and construction, and the content of alumina is not particularly limited.
Several types of alumina cements having different mineral compositions are known and commercially available, but the main component is monocalcium aluminate, and any commercially available product can be used regardless of the type.
The amount of the alumina cement used is preferably 20 to 80 parts by mass, more preferably 23 to 75 parts by mass, more preferably 25 to 70 parts by mass, and particularly preferably 30 to 65 parts by mass with respect to 100 parts by mass of the solid content of the emulsion. It is preferable to set it as a mass part.
Alumina cement is a component necessary for promoting the drying of the coated material by a hydration reaction and for improving the water resistance and securing the strength of the cured coating film. However, when the addition amount is less than 20 parts by mass, the alumina cement is dried. If it is insufficient, and if it exceeds 80 parts by mass, the pot life will be short and the workability will be hindered.

A phyllosilicate is added to the waterproof polymer cement composition of the present invention. As the phyllosilicate mineral, mica and pyrophyllite can be used, but talc and serpentine are preferably used.
The use of phyllosilicate, which is a layered silicate, imparts leveling properties, improves roller sliding during roller coating and elongation of the polymer cement composition, and significantly reduces cornering. In addition, when roller coating is performed from above the nonwoven fabric, it is possible to improve material retention by utilizing the property that the particle shape is layered and oriented so that only moisture does not escape under the nonwoven fabric, thereby significantly reducing material separation. It is possible to improve.
The amount of the phyllosilicate mineral used is preferably 4 to 80 parts by weight, more preferably 6 to 70 parts by weight, more preferably 8 to 60 parts by weight, particularly preferably 10 to 100 parts by weight of the solid content of the emulsion. It is preferable to set it as -50 mass parts. Outside this range, for example, if the amount is less than 4 parts by mass, the leveling effect cannot be obtained. On the other hand, if it exceeds 80 parts by mass, the thickening effect increases and workability is impaired.
The phyllosilicate mineral preferably has a particle size of about 5 to 20 μm from the viewpoint of leveling properties and thickening.

  Silica sand is suitably used in terms of surface accuracy, No. 5-7, the amount used is preferably 20-240 parts by weight, more preferably 30-200 parts by weight, based on 100 parts by weight of the solid content of the emulsion. More preferably, it is 40 to 180 parts by mass, and particularly preferably 40 to 160 parts by mass.

  The waterproof polymer cement composition of the present invention comprises an ethylene vinyl acetate copolymer emulsion and an acrylic polymer emulsion constituting the emulsion, and a predetermined amount of each of alumina cement, phyllosilicate mineral, and silica sand. It can be prepared by mixing. Each component may be added alone, or may be added in advance with a mixture of several other components. The order of addition is not particularly selected. As the stirrer, a general solid-liquid stirrer can be used without any problem.

The waterproof polymer cement composition of the present invention includes an ethylene vinyl acetate copolymer emulsion and an acrylic polymer emulsion constituting the emulsion, and other Portland cement, gypsum, blast furnace slag, etc., excluding alumina cement and phyllosilicate mineral. Hydraulic components, other emulsions, silica sand, slag powder, fly ash, limestone powder, kaolin, alumina powder, titanium oxide, aluminum hydroxide, mica, pyrophyllite, glass fiber, etc., plate, fiber, etc. These fillers can be added and used within a range not impairing the properties, and one or more of these fillers can be used.
The waterproofing polymer cement composition of the present invention includes a setting rate adjusting agent such as a setting retarder and a setting accelerator, a water reducing agent, a fluidizing agent, an antifoaming agent, a thickener, water and the like as long as the characteristics are not impaired. These components can be used alone or in combination of two or more.

  The polymer cement composition obtained by mixing the constituent raw materials is used by being applied to the surface of the workpiece by a general method using a roller, a trowel or the like. It is preferable to repeat the same operation after the coating film is dried to form a plurality of coating films. In addition, when the construction is such that the mesh is sandwiched between the coatings on the rooftop, etc., there is a method of adding a step of placing the mesh on the coating after drying, applying from above the mesh and fixing the mesh Can be adopted. In any case, the outermost layer is finished by forming a protective layer on which a polymer cement composition made of another composition is applied and dried.

The waterproof polymer cement composition of the present invention can obtain a concrete structure having a waterproof layer by laminating the concrete layer in the order of the cured product layer of the waterproof polymer cement composition of the present invention. The concrete layer may be provided with a primer cured product layer on the top surface of the concrete layer.
As the concrete layer, mortar can be used in addition to known concrete.

When showing an example of the construction of a concrete structure using the waterproof polymer cement composition of the present invention,
(1) Placing concrete or mortar on the roof, floor or wall, finishing it with a trowel, machine, etc., then curing the concrete or mortar to form a concrete layer,
(2) Apply or spray a primer (diluted solution or diluted aqueous solution) on the concrete layer surface by a general method using a roller, a trowel, a spray, etc., and then form a cured product layer obtained by curing the primer,
(3) Applying the polymer cement composition of the present invention to the surface of the cured product layer of the primer by a general method using a roller, a trowel and a spray, and then forming a cured product layer obtained by curing the polymer cement composition. Thus, a concrete structure can be constructed.
The formation of the cured product layer of the primer (2) can be omitted.

The cured product layer of the primer is a layer made of a cured product of a known resin-based emulsion such as an ethylene-vinyl acetate copolymer emulsion or an acrylic resin emulsion as a primer.
It is preferable to use the same resin component as the emulsion contained in the polymer cement composition of the present invention for the cured product layer of the primer because the adhesion strength between the primer layer and the polymer cement composition of the present invention is excellent.

The waterproof polymer cement composition of the present invention is used for the purpose of imparting waterproofness to a construction object when constructing a concrete structure or the like.
The waterproof polymer cement composition of the present invention can be used for waterproofing applications such as waterproofing concrete, waterproofing concrete floors, waterproofing concrete rooftops, etc., and can obtain a concrete structure coated on the surface of concrete work. I can do it.
The waterproof polymer cement composition of the present invention is applied to the roof, underground, veranda, etc. of a concrete structure in order to impart waterproofness.

  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) Measurement of glass transition temperature of emulsion: An appropriate amount of emulsion was dropped on a glass plate and dried at 60 ° C. for 16 hours, and the resulting coated film had a mass within the range of 9.5 to 10.5 mg. The glass transition temperature is measured using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50).
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.

Example 1 and Comparative Examples 1-3
(1) Raw materials: The following raw materials were used.
PVA-EVA emulsion: manufactured by Denki Kagaku Kogyo Co., Ltd., EVA # 59 (ethylene vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid, glass transition temperature: −15 ° C.).
Acrylic polymer emulsion: Pegar 842 (glass transition temperature: −15 ° C.) manufactured by High Pressure Gas Industry Co., Ltd.
Alumina cement: Fondue manufactured by Lafarge Aluminate.
-Talc: Talc S, manufactured by Nippon Talc Co., Ltd.
Silica sand: No. 6 silica sand manufactured by Ube Sand Industry Co., Ltd.

(2) Preparation of polymer cement composition In a 2 L plastic container, a total of 500 g of emulsion solids and a total of 750 g of alumina cement, talc and silica sand were mixed for 3 minutes under a condition of 1300 rpm using a 0.15 KW stirrer. A polymer cement composition having a mixing ratio of 1 was obtained.

(3) Evaluation (roller workability): The roller workability was evaluated as follows.
A primer (a solution obtained by adding water to the emulsion mixtures of Examples and Comparative Examples shown in Table 1 and diluting 10 times) was applied to the concrete surface that had been iron-finished in an amount of 0.4 kg / m ² and left for 1 day. On the next day, the polymer cement composition indicated by P-1 to 4 in Table 1 is applied with a commercially available general-purpose roller [Wooter B manufactured by Otsuka Brush Manufacturing Co., Ltd.] in an amount of 0.9 kg / m ² to form the first layer. I let you. The formed layer was visually observed for skinning (after 5 minutes), overcoating when uncured, cornering, and elongation of the polymer cement composition. The results are shown in Table 2.

After the drying of the first layer, the polymer cement composition used for forming the first layer is applied from the top of the first layer in an amount of 0.2 to 0.3 kg / m ² , and the non-woven fabric (made of polyester, weight per unit of 30 g / m) is applied thereon. ² ) and the same polymer cement composition was applied in an amount of 0.6 to 0.7 kg / m ² to form a second layer. For the second layer, material separation and cornering were visually observed. The results are shown in Table 2.

Evaluation items and evaluation criteria for each item are as follows.
1) Skinning: Skinning generated on the surface of the polymer cement composition after coating [not generated at all: ◎, hardly generated: ○, considerably generated: Δ, generated frequently: ×].
2) Overcoatability: State of the coated surface when overcoated when uncured [same state as the first layer: ◎, slightly more uneven than the first layer: ○, considerably more uneven than the first layer: Δ, more than the first layer Very many irregularities ×].
3) Standing property (surface accuracy): Roller pattern generated during roller application [not generated at all: ◎, hardly generated: ○, considerably generated: Δ, generated frequently: ×].
4) Roller slipperiness: resistance during roller application [light: ◎, fairly light: ◯, slightly heavy: △, heavy: ×].
5) Material separation: State of the polymer cement composition on the nonwoven fabric after roller application [same uniformity as before application: ◎, slightly liquid content: ○, quartz sand is conspicuous and little liquid content: △, liquid only with silica sand There is little minute: x].

(4) Evaluation (physical properties of coating film): Evaluation of coating film properties was performed as follows.
6) Elongation rate: The polymer cement composition was applied in an amount of 1.8 kg / m ² on a glass plate with a PET film laid on it, and 2 under conditions of 20 ± 3 ° C. and humidity of 65 ± 5%. The coating was peeled off after curing for 20 days, and the specimens were further cured for 26 days at 20 ± 3 ° C and 65 ± 5% humidity, and further deteriorated for 2500 hours and 4000 hours with a sunshine weather meter specified by JIS K-5400. Autograph (TENSILON / UTM-I-2500, manufactured by Toyo Baldwin Co., Ltd.) in which the test pieces were respectively extracted with dumbbell No. 1 and the ambient temperature of the measurement part was set to 0 ° C. and 20 ° C. A tensile test was conducted at a speed of 200 mm / min to measure the elongation. The results are shown in Table 2.

7) Substrate crack followability test: Primer was applied in an amount of 0.4 kg / m ^{2 in} advance, and a polymer cement slurry was applied to 1.8 mm / m ^{2 on} a 5 mm thick slate plate (50 × 150 mm) cut in the center. And a specimen that was cured for 28 days under the conditions of 20 ± 3 ° C. and humidity of 65 ± 5%, and further a specimen that was deteriorated for 4000 hours with a sunshine weather meter defined in JIS K-5400. Was subjected to a tensile test at a rate of 5 mm / min using an autograph (the above tester) in which the ambient temperature of the measurement part was set to 0 ° C. and 20 ° C., and the amount of elongation when a crack occurred in the coating film was measured. The results are shown in Table 2.

As is clear from Table 2, Example 1 using the waterproof polymer cement composition of the present invention has good angularity at the time of roller work, roller slipperiness, and material separation at the time of using a nonwoven fabric. In addition, good results were also obtained for the elongation and the base followability after the accelerated weather resistance test.
On the other hand, Comparative Example 1 is an example in which an acrylic emulsion and talc are not blended, but the roller workability other than skin-strength is very inferior, and the elongation rate and ground followability after the accelerated weather resistance test are also poor. It was. Comparative Examples 2 and 3 are examples in which acrylic emulsion and talc are not blended, but it is also confirmed that the roller workability is considerably inferior.

Claims (3)

A waterproof polymer cement composition comprising alumina cement, emulsion and talc ,
The emulsion contains an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion. The solid content of the acrylic polymer emulsion is 3 to 20 parts by mass with respect to 100 parts by mass of the solid content of the ethylene-vinyl acetate copolymer emulsion. seen including at a rate of,
A polymer cement composition for a waterproof film layer , comprising 4 to 80 parts by mass of talc with respect to 100 parts by mass of the solid content of the emulsion . The polymer cement composition for waterproof film layers according to claim 1, comprising 20 to 80 parts by mass of alumina cement with respect to 100 parts by mass of the solid content of the emulsion. The solid content 100 parts by weight of the emulsion, waterproof film layer polymer cement composition according to claim 1, characterized in that it comprises 20 to 80 parts by weight of alumina cement 及 beauty sand 20 to 240 parts by weight.