JP2004262748A - Polymer cement composition for waterproofing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer cement composition for waterproofing which is applied without skill even in the application with a roller, has excellent work efficiency, gives a coating film exhibiting excellent finishing without causing sharp edge, material separation or skinning as the characteristics and a structure having excellent water resistance, adhesiveness, elongation at a low temperature, and weatherability. <P>SOLUTION: The polymer cement composition for waterproofing is prepared by blending 20-80 pts.mass alumina cement, 40-80 pts.mass phyllosilicate mineral, and 20-240 pts.mass silica sand to 100 pts.mass solid portion of an emulsion mixture prepared by adding 3-20 pts.mass acrylic emulsion solid portion to 100 pts.mass solid portion of ethylene-vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

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

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

For example, Patent Document 1 discloses an uncured cementitious composition having improved flexural strength, comprising 100 parts by weight of alumina cement, 200 to 500 parts by weight of slag, silica or calcium carbonate, and a water-dispersible polymer. I have.
Patent Document 2 discloses a nonionic surfactant as a coating composition for forming a waterproof film layer having excellent elongation-strength, water resistance, alkali resistance, etc., and capable of closing cracks by absorbing and swelling water leakage. There is disclosed a coating composition for concrete structures containing, as a main component, an ethylene-vinyl acetate copolymer resin emulsion obtained by using an emulsifier as an emulsifier, and an acrylic resin emulsion and lime aluminate or silica sand mixed therewith.

JP-A-04-240145 Japanese Patent Application Laid-Open No. 09-087061

  An object of the present invention is to provide a waterproof polymer cement composition in which the above-mentioned disadvantages of the conventionally used waterproof polymer cement composition are improved. Specifically, in the case of construction, even with a roller, no skill is required and workability is good, and characteristically, a good finish of the coating film without squaring, material separation and skinning It is an object of the present invention to provide a polymer cement composition for waterproofing which gives a structure excellent in water resistance, adhesion, elongation at low temperature, and weather resistance.

The present invention is a waterproof polymer cement composition comprising alumina cement, an emulsion and a phyllosilicate mineral,
The emulsion contains an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion, and the solid content of the acrylic polymer emulsion is 3 to 20 parts by mass based on 100 parts by mass of the solid content of the ethylene-vinyl acetate copolymer emulsion. It is an object of the present invention to provide a waterproof polymer cement composition characterized in that it contains the polymer cement composition at a ratio of:
The solids content of the emulsion is the polymer solids content of the emulsion.

Preferred embodiments of the polymer cement composition for waterproofing of the present invention are shown below.
In the polymer cement composition for waterproofing, 20 to 80 parts by mass of alumina cement and 20 parts by mass of phyllosilicate are added to 100 parts by mass of the solid content of the emulsion (a mixture of the solid content of the ethylene-vinyl acetate copolymer emulsion and the solid content of the acrylic polymer emulsion). It is preferable to contain 4 to 80 parts by mass of an acid salt mineral.
In the polymer cement composition for waterproofing, 20 to 80 parts by mass of alumina cement and 20 parts by mass of phyllosilicate are used for 100 parts by mass of the solid content of the emulsion (a mixture of the solid content of the ethylene-vinyl acetate copolymer emulsion and the solid content of the acrylic polymer emulsion). It is preferable to contain 4 to 80 parts by mass of an acid salt mineral and 20 to 240 parts by mass of silica sand.
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 polymer cement composition for waterproofing of the present invention provides not only excellent workability but also a waterproof film layer excellent in coating film properties and weather resistance. Therefore, its utility value is high in imparting waterproofness to concrete structures.

  The emulsion includes at least two types of emulsions, an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion, and may include other emulsions as long as the properties are not affected.

  As the emulsion, those obtained by a known production method can be used.For example, in the presence of an emulsifier, a polymerization initiator is used to carry out emulsion polymerization of a polymerizable monomer as a raw material of a synthetic resin in water or a water-containing solvent using a polymerization initiator. It can be manufactured by such a method.

As the emulsifier, a known emulsifier 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 water-containing solvent are preferable, and examples thereof include water-soluble peroxides such as hydrogen peroxide, peracetic acid, persulfuric acid, and 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 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 hydrated solvent, and if powdery synthetic resin particles are used, all components except for the water or hydrated solvent can be packaged in one package. It is convenient because 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 lower, More preferably, it is 0 ° C. or lower, or preferably −50 ° C. to 10 ° C., and more preferably −40 ° C. to 0 ° C., in order to secure elongation and substrate followability.
As the ethylene-vinyl acetate copolymer emulsion, those using a water-soluble polymer such as polyvinyl alcohol or a cellulose derivative as an emulsifier or protective colloid can be preferably used. In particular, the ethylene-vinyl acetate copolymer emulsion preferably uses 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, methyl cellulose, hydroxyethyl cellulose, etc., have poor kneading properties depending on the alumina cement species to be combined. It can be. On the other hand, an ethylene-vinyl acetate copolymer emulsion in which polyvinyl alcohol is used as a protective colloid (hereinafter, referred to as a PVA-EVA emulsion) is preferable because the effect of the alumina cement species on the kneading properties is hardly recognized.

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, and 2-ethylhexyl (meth) acrylate is used. Alternatively, those obtained by polymerizing two or more kinds, and those obtained by copolymerizing with a vinyl compound such as styrene, vinyl acetate, and vinylidene chloride which can be copolymerized with these monomers can be used. (Meth) acrylate means methacrylate and acrylate.
The acrylic polymer emulsion is preferred 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.

As 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.
A known emulsion can be used as the acrylic resin emulsion, 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 lower, more preferably 0 ° C. or lower. Or, preferably, -50 to 10 ° C, and more preferably, -40 to 0 ° C, in order to secure elongation and substrate followability.

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

  The weather resistance is very important for a waterproof material used on the roof of a concrete structure or the like, and in particular, it is required to be able to follow a basement crack. In general, cracks in concrete have seasonal fluctuations, and cracks of 0.2 mm in summer increase to a maximum of about 0.9 mm in winter. Defects or breakage, and no longer serves as a waterproof material. Furthermore, it is very difficult to maintain the base crack following property 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 a PVA-EVA emulsion, 0.9 mm or more, preferably 1.2 mm or more, more preferably 1.5 mm or more, particularly preferably 1.8 mm or more can be maintained.

  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 the solid content of the acrylic polymer emulsion, based on 100 parts by mass of the solid content of the ethylene-vinyl acetate copolymer emulsion. It is preferably from 5 to 20 parts by mass, particularly preferably from 6 to 20 parts by mass. If 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, while if it exceeds 20 parts by mass, the skinning at the time of applying the polymer cement composition becomes insufficient. There is a possibility that the horn may be quickly and sharply formed, resulting in a decrease in workability.

Alumina cement can be used without any problem even if it is used for refractories, civil engineering, construction, and the like, and the content of alumina can be used without any particular limitation.
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, particularly preferably 30 to 65 parts by mass, based on 100 parts by mass of the solid content of the emulsion. It is preferable to use parts by mass.
Alumina cement is a component required to promote the drying of the coated material by a hydration reaction and to improve the water resistance of the cured coating film and to ensure the strength. If it is insufficient, and if it exceeds 80 parts by mass, the pot life will be short and workability will be impaired.

The phyllosilicate is added to the polymer cement composition for waterproofing of the present invention. As the phyllosilicate mineral, mica and pyrophyllite can be used, but talc and serpentine are preferred.
The use of the 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 squaring. In addition, when applying a roller over the nonwoven fabric, the material is remarkably separated by using the property that the particle shape is oriented in a layered form, improving the water retention of the slurry, and preventing only water from escaping under the nonwoven fabric. It is possible to improve.
The amount of the phyllosilicate mineral to be used is preferably 4 to 80 parts by mass, more preferably 6 to 70 parts by mass, more preferably 8 to 60 parts by mass, particularly preferably 10 to 100 parts by mass based on 100 parts by mass of the solid content of the emulsion. It is preferable to set it to 50 parts by mass. If the amount is out of this range, the leveling effect cannot be obtained if the amount is less than 4 parts by mass, for example, while if it exceeds 80 parts by mass, the thickening effect becomes large and the workability is impaired.
In addition, it is preferable to use the phyllosilicate mineral having a particle diameter of about 5 to 20 μm from the viewpoint of leveling property and viscosity increase.

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

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

The polymer cement composition for waterproofing according to the present invention comprises an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion constituting an emulsion, and other portland cement, gypsum, blast furnace, etc., excluding alumina cement and phyllosilicate minerals. Hydraulic component, other emulsion, silica sand, slag powder, fly ash, limestone powder, kaolin, alumina powder, titanium oxide, aluminum hydroxide, mica, pyrophyllite, glass fiber, etc., plate, fiber, etc. Can be added and used within a range that does not impair the properties, and one or more of these fillers can be used.
The polymer cement composition for waterproofing of the present invention contains a setting speed regulator such as a setting retarder and a setting accelerator, a water reducing agent, a fluidizing agent, an antifoaming agent, a thickener, and water as long as the properties 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 work by a general method using a roller, a trowel or the like. It is preferable that the same operation is repeated after drying the coating film to form a plurality of coating films. In addition, in the case of a structure in which a mesh is sandwiched between coating films for construction on a rooftop or the like, a method of placing a mesh on the dried coating film and applying a process of applying the mesh from above and fixing the mesh is used. Can be adopted. In any case, the polymer layer is applied to a polymer cement composition composed of another composition and dried to form a protective layer on the outermost layer, thereby completing the finishing.

The concrete structure having the waterproof layer can be obtained by laminating the polymer cement composition for waterproofing of the present invention on the concrete layer in the order of the cured layer of the polymer cement composition for waterproofing of the present invention. The concrete layer may be provided with a cured product layer of the primer on the upper 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 polymer cement composition for waterproofing of the present invention,
(1) Cast concrete or mortar on the roof, floor or wall, finish with iron, machine, etc., then harden concrete or mortar to form concrete layer,
(2) On the surface of the concrete layer, a primer (a diluted liquid or a diluted aqueous solution of an emulsion) is applied or sprayed by a general method using a roller, a trowel, a spray, and the like, and then a cured product layer in which the primer is cured is formed.
(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, a spray, and the like, and then forming a cured product layer obtained by curing the polymer cement composition. Thereby, a concrete structure can be constructed.
The formation of the cured product layer of the primer of the above (2) can be omitted.

The cured product layer of the primer is a layer composed 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 adhesive strength between the primer layer and the polymer cement composition of the present invention is excellent.

The polymer cement composition for waterproofing of the present invention is used for the purpose of imparting waterproofness to a construction when constructing a concrete structure or the like.
The polymer cement composition for waterproofing of the present invention can be used for waterproofing purposes such as concrete waterproofing, concrete floor waterproofing, and concrete roof waterproofing, and can obtain a concrete structure applied to the surface of a concrete workpiece. I can do it.
The polymer cement composition for waterproofing of the present invention is applied to the roof, basement, veranda and the like 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, dried at 60 ° C for 16 hours, and a dried coating film having a weight of 9.5 to 10.5 mg was obtained. The glass transition temperature is measured using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation).
The DSC measurement conditions were as follows: the temperature was raised from room temperature to 150 ° C. in 10 minutes, kept at 150 ° C. for 10 minutes, lowered to a temperature 50 ° C. lower than the Tg of the sample obtained by calculation, and then raised again to 150 ° C. in 10 minutes. When warming, a first measurement of Tg is made. Next, when the temperature is lowered to a temperature 50 ° C. lower than the Tg measured in the first time, the second time Tg is measured, and the value of the second time Tg is defined as the glass transition temperature.

Example 1 and Comparative Examples 1 to 3
(1) Raw materials: The following raw materials were used.
-PVA-EVA emulsion: manufactured by Denki Kagaku Kogyo KK, EVA # 59 (ethylene-vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid, glass transition temperature: -15 ° C).
Acrylic polymer emulsion: Girl 842 (glass transition temperature: −15 ° C.) manufactured by Koatsu Gas Industries Co., Ltd.
-Alumina cement: Fountain, manufactured by Lafarge Aluminum.
-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 A total of 500 g of the solid content of the emulsion and a total of 750 g of alumina cement, talc and silica sand were mixed in a 2 L plastic container for 3 minutes at 1300 rpm using a 0.15 kW stirrer. A polymer cement composition having a compounding ratio of 1 was obtained.

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

After drying 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 a nonwoven fabric (polyester, basis weight 30 g / m ² ) is further applied thereon. ² ) was placed, and the same polymer cement composition was further 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 squaring were visually observed. The results are shown in Table 2.

The evaluation items and the 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: x].
2) Overcoating property: State of the coated surface when overcoated when uncured [same state as the first layer: ◎, slightly more irregularities than the first layer: ○, considerably more irregularities than the first layer: △, more than the first layer X with very many irregularities].
3) Squaring property (surface accuracy): Roller pattern generated at the time of applying the roller [not generated at all: ◎, hardly generated: 、, considerably generated: Δ, frequently generated: x].
4) Slipperiness of the roller: Resistance at the time of applying the roller [light: ◎, considerably light: ○, slightly heavy: △, heavy: ×].
5) Material separation: State of polymer cement composition on non-woven fabric after roller application [Same uniformity as before application: ◎, little liquid content: ○, silica sand is noticeable, little liquid component: △, liquid only with silica sand There is almost no minute: X].

(4) Evaluation (physical properties of coating film): Evaluation of coating film properties was performed as follows.
6) Elongation: The polymer cement composition is applied at a rate of 1.8 kg / m ² on a PET film spread on a glass plate, and is applied under conditions of 20 ± 3 ° C. and 65 ± 5% humidity. After curing for one day, the coating film was peeled off, and the specimen was further cured for 26 days at 20 ± 3 ° C. and 65 ± 5% humidity, and further degraded for 2500 hours and 4000 hours with a sunshine weather meter specified by JIS K-5400. An autograph (Tensilon / UTM-I-2500, manufactured by Toyo Baldwin Co., Ltd.) was prepared by extracting test pieces from the test pieces with a dumbbell No. 1 and setting the ambient temperature of the measurement section to 0 ° C. and 20 ° C. Was used to perform a tensile test at a speed of 200 mm / min to measure the elongation. Table 2 shows the results.

7) Substrate crack followability test: A primer was applied in an amount of 0.4 kg / m ^{2 in} advance, and a polymer cement slurry of 1.8 kg / m ² was placed on a 5 mm thick slate plate (50 × 150 mm) with a cut in the center. And a test specimen cured for 28 days under the conditions of 20 ± 3 ° C. and 65 ± 5% humidity and a test specimen which was further deteriorated for 4000 hours by a sunshine weather meter specified by JIS K-5400. Was subjected to a tensile test at a rate of 5 mm / min using an autograph (the above-described testing machine) in which the ambient temperature of the measuring section was 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 polymer cement composition for waterproofing of the present invention has good squaring property during roller work, roller sliding property, and material separation property when using nonwoven fabric. Good results were also obtained with respect to the elongation and the substrate followability after the accelerated weathering test.
On the other hand, Comparative Example 1 is an example in which the acrylic emulsion and talc were not blended, but the roller workability other than the skinning property was very poor, and the elongation and the substrate followability after the accelerated weathering test were also poor. Was. Comparative Examples 2 and 3 are examples in which the acrylic emulsion and talc were not blended, but it was also confirmed that the roller workability was considerably poor.

Claims (4)

A waterproof polymer cement composition comprising alumina cement, an emulsion and a phyllosilicate mineral,
The emulsion contains an ethylene-vinyl acetate copolymer emulsion and an acrylic polymer emulsion, and the solid content of the acrylic polymer emulsion is 3 to 20 parts by mass based on 100 parts by mass of the solid content of the ethylene-vinyl acetate copolymer emulsion. A polymer cement composition for waterproofing, characterized in that: The polymer cement composition for waterproofing according to claim 1, comprising 20 to 80 parts by mass of an alumina cement and 4 to 80 parts by mass of a phyllosilicate mineral based on 100 parts by mass of a solid content of the emulsion.   The waterproofing polymer according to claim 1, wherein the emulsion contains 20 to 80 parts by mass of alumina cement, 4 to 80 parts by mass of phyllosilicate mineral, and 20 to 240 parts by mass of silica sand based on 100 parts by mass of the solid content of the emulsion. Cement composition. The waterproofing polymer cement composition according to any one of claims 1 to 3, wherein the ethylene-vinyl acetate copolymer emulsion is an ethylene-vinyl acetate copolymer emulsion using polyvinyl alcohol as a protective colloid.