JPH10218653A - Polymer cement-based composition for finishing, and production of cement-based formed product by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer cement-based composition for finishing not only capable of freely changing the thickness of coating but also having a high ratio of a polymer to a cement, good in drying properties while manifesting the characteristics of the polymer, hardly causing a crack when drying and extremely superior in spraying properties, and further, to provide a method for producing a cement-based formed product by using the polymer cement-based composition. SOLUTION: This polymer cement-based composition for finishing comprises a hydraulic cement, a polymer comprising 100 pts.wt. water-redispersible resin powder and 100-250 pts.wt. resin aqueous emulsion (in terms of solid) and an inorganic filler. Further, the total amount of the polymers is 40-120wt.% based on the amount of the hydraulic cement and the amount of the inorganic filler is 100-600wt.% based on the hydraulic cement. The polymer cement-based composition is formed into an aqueous slurry, coated on the interior surface of a prescribed formwork having freely releasing properties to provide a coated film, and superposing and forming a water slurry-like cement material on the coated film to provide the objective cement-based formed product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer-cement composition for finishing suitable as a polymer-cement mortar for thick coating mainly by spraying, and a method for producing a cement-based molded product using the same. .

[0002]

2. Description of the Related Art Cement mortar and cement concrete using hydraulic cement such as Portland cement are general civil engineering and building materials. It has drawbacks due to the hydrate, such as slow cure, low tensile strength, high drying shrinkage, or low chemical resistance. For the purpose of improving such disadvantages of cement mortar and the like, styrene-butadiene rubber latex, vinyl acetate-based emulsion, ethylene-vinyl acetate emulsion, acrylic There has been proposed a polymer-cement mortar or the like in which a resin aqueous emulsion such as a system emulsion is blended and a part of the cement hydrate is substituted. Such polymer cement mortars and the like, compared with conventional cement mortars and the like, workability, water retention, tensile and bending strength, elongation ability, adhesion,
It has various excellent properties such as waterproofness, impact resistance, abrasion resistance, chemical resistance, and is used for paving materials, flooring materials, waterproofing materials,
It is widely and widely used as a civil engineering building material such as an adhesive, a decorative finishing material, a repair material, or an anticorrosive material.

[0003] Incidentally, the use ratio of the aqueous resin emulsion in such a polymer-cement mortar is 5 to 1%.
It is kept as low as 0% by weight. Originally, the higher the polymer-cement ratio (P / C) of the aqueous resin emulsion, the more stable and good the results can be obtained, but on the other hand, the higher the ratio of the aqueous resin emulsion, the higher the surface drying. Not only is the property quick and very easy to dry, but when the coating is thick, the center is undried and cracks are likely to occur, and it is sticky and very difficult to handle.

For this reason, a polymer cement having a high P / C ratio and good performance is gradually sprayed and used from the conventional plastering work, and the P / C ratio at that time is generally 30 to 50%. Since the surface is dried quickly, it cannot be applied thickly at a time, and the spraying operation has to be performed several times at about 500 to 1500 μm. However, no matter how careful you work, it may become partially thick,
Corner portions, uneven portions, complicated shapes, grooves, and the like are thick, and these portions are liable to cracks. In order to solve the conventional problems, it has been proposed to use an additive which lowers the polymer component or improves water drainage and lowers surface drying in the composition. The fact is that you cannot expect results.

In recent years, the number of buildings and civil engineering structures conscious of harmony with the natural environment and surrounding scenery has increased, and the need for scenic properties has been greatly increased. For this reason, for example, concrete walls such as retaining walls for road and residential land development work, river revetments, dams, piers, etc. are different from conventional smooth surfaces.
Attention has been paid to a method of forming natural stones and rocks on a wall as if they were piled up. As such a method, there is a method of fixing a decorative form having a natural rock-like pattern on the inner surface of the concrete form at the construction site, casting a concrete there, and sequentially forming the form into a masonry. Alternatively, a method has been generally adopted in which a factory-cast concrete wall with a pattern using a decorative formwork is stacked at a construction site.

By the way, in the case of such a conventional method, due to the properties of the concrete itself as described above, aside from the fact that the pattern of the decorative form is relatively smooth,
In the case of knurls, irregularities, complicated shapes, grooves, etc., the familiarity of the casting concrete is very poor, and it is not only difficult to show a satisfactory pattern, but also a strong surface and shape retention. It is said that there is a problem in terms of.

As a solution to the above-mentioned problems, there is disclosed a method in which a plastic paint is applied to the inner surface of a decorative mold to form a film, and a concrete is cast on the film to form the film (Japanese Patent Application Laid-Open No. H10-163686). See JP-A-62-33607). However, such a method has various problems in the case of a pattern of a complicated shape having a better appearance, in which irregularities are preferred, aside from the case where the pattern of the decorative mold frame is smooth. That is, when having a complicated pattern as described above, a paint that is usually used at about 50 to 300 μm is often used, and sometimes it is in mm units, and cracks may occur in this part. There are many. This is the surface drying due to thickness and shrinkage during drying, and
This is because the decorative frame is a plastic having no water absorption.
Although these can be improved to some extent by various additives and compounding agents, they often affect the performance of the coating film. Also, in the case of a concrete surface with a fine linear pattern in design, spraying a paint coating material etc. on the concrete surface will cause the fine pattern to blur, and the appearance by spraying The texture on top will change. In addition, paints and coating materials (thick coating materials) are liable to cause trouble if not used after the concrete is cast and cured sufficiently.
In particular, a paint containing an organic resin as a main component has a limit in durability, and is not preferable for a paint requiring a long life such as a civil engineering structure. From this aspect, resin mortar-based coating materials have begun to be used in recent years, but the coating thickness is about 1 mm, and when the thickness is several mm, cracks and the like are less likely to occur, and coating is required again.

The inventor of the present invention has conducted intensive studies to solve the above-mentioned conventional problems. As a result, the use of the water-redispersible resin powder together with the aqueous resin emulsion allows the coating thickness to be freely adjusted. Not only can the polymer-cement composition have a high polymer-cement ratio and good drying properties while sufficiently exhibiting the properties of the polymer, are less likely to cause cracks and the like upon drying, and are extremely excellent in sprayability, And a method for producing a cement-based molded product using the same.

[0009]

That is, the first invention of this application is a hydraulic cement and a water redispersible resin powder 100.
1 part by weight and aqueous resin emulsion (as solid content)
A polymer consisting of 100 to 250 parts by weight, and an inorganic filler
Wherein the total amount of the polymer is 40 to 120% by weight with respect to the hydraulic cement, and the amount of the inorganic filler is 100 to 600% by weight with respect to the hydraulic cement. The gist is a system composition.

[0010] The second invention of this application is claim 1
A water-slurry is formed from the polymer-cement composition for finishing described above, and this is applied to the inner surface of a required mold form which can be freely released to form a film, and then a water-slurry-like cement material is formed on the film. And a method for producing a cement-based molded product, characterized in that the method is repeated.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer-cement composition for finishing of the present invention uses a water redispersible resin powder and a resin aqueous emulsion in combination within a specific range as a polymer, and further uses a hydraulic cement. As a result, a highly durable film is formed in spite of the very high P / C ratio, and it is possible not only to form a thick coat by spraying fresh concrete, but also to prevent the occurrence of cracks. It can be used very suitably for cosmetics, surface protection and curing. In addition,
The finishing polymer-cement composition of the present invention comprises a polymer
Although it can be applied not only to cement mortar but also to polymer cement concrete, it is particularly suitable for use as polymer cement mortar.

The water redispersible resin powder in the present invention includes polyvinyl acetate, vinyl acetate ethylene copolymer,
Alternatively, a so-called water redispersible resin powder obtained by spray drying an acrylic resin emulsion is used. Such a water-redispersible resin powder has a characteristic of easily re-emulsifying when water is added and returning to an original aqueous polymer, and may be used directly as a premix in a hydraulic cement described later. In addition, when the water redispersible resin powder is hard, a hard and strong film is obtained, and when a soft material is used, a soft film is obtained. However, a film having a film forming temperature (MFT) of +25 to -50 ° C. By using it, a film having a softness can be obtained even if it is hard under a normal use temperature range (+35 to -10 ° C). At this time, unless the total amount of the aqueous resin emulsion described later is 40% by weight or more based on the hydraulic cement, the effect as a spray finishing material is small.

The water-redispersible resin powder used in the present invention comprises:
Sumika Flex (registered trademark) RP-100S, RP-110 manufactured by Sumitomo Chemical Co., Ltd., Mitsubishi Kagaku BI-
Acronal (registered trademark) DS- manufactured by SF Corporation
6029, DS-6031, Movinyl (registered trademark) DM-200, DM-289, 8 manufactured by Hoechst Gosei Co., Ltd.
43, SA, E45 and the like. In addition, about the manufacturing method of such a water redispersible resin powder,
JP-A-47-8188, JP-A-59-19970
No. 3, JP-A-6-24820, Japanese Patent Application No. 4-1.
85606, JP-A-7-53730, JP-B-7-30221, JP-A-7-138062, JP-A-7-187741, and JP-A-7-180.
No. 86, US Pat. No. 4,704,416, US Pat. No. 3,784,648, US Pat. No. 5,1187.
No. 51, etc. and in the literature.

Examples of the aqueous resin emulsion include 2-ethylhexyl acrylate and n · acrylic acid.
Butyl, ethyl acrylate, isopropyl acrylate,
2-ethylhexyl methacrylate, n-propyl acrylate, n-butyl methacrylate, vinyl acetate, acrylic acid, n-propyl methacrylate, styrene, acrylonitrile, methyl methacrylate, methacrylic acid, maleic anhydride, itaconic acid, acrylamide , An emulsion of a homopolymer or copolymer obtained by emulsion polymerization of one or more unsaturated monomers selected from ethyl methacrylate, ethylene, butadiene, and the like. A mixture of two or more is used. Also, an aqueous emulsion of a curable resin such as an aqueous epoxy emulsion can be used. Furthermore,
Urethane emulsions, aqueous urethane solutions, and silicone emulsions can also be used.

[0015] These aqueous resin emulsions are manufactured by Sumikaflex (registered trademark) S-manufactured by Sumitomo Chemical Co., Ltd.
401 / S-420, Acronal (registered trademark) S-400, 80D manufactured by Mitsubishi Chemical BSF Co., Ltd.
N, YJ3042D, and YJ3031D are commercially available. The above-mentioned Acronal S-400 and Acronal YJ3042D are aqueous emulsions of an acrylate-styrene copolymer resin, and Acronal 80DN is an aqueous emulsion of an acrylonitrile-acrylate copolymer resin. . When soft performance is required, the Tg of the resin is preferably 5 ° C. or less,
Tg of 30 ° C. or less is preferable from the viewpoint of film forming property, although not limited to the case of a hard feeling.

The ratio of the water redispersible resin powder to the resin aqueous emulsion is 100 to 250 parts by weight with respect to 100 parts by weight of the water redispersible resin powder. It has poor coating workability such as spraying, and has poor finish. A certain amount of stickiness is required, and separation of the filler and the aggregate occurs (separation is easy with water dilution). On the other hand, when the amount exceeds 250 parts by weight, the drying property at the time of thick film and the surface crack resistance deteriorate. In spraying, brush coating, or flow coating, generally a P / C ratio of 50 to 200% is used to improve fluidity, but in the present invention, the P / C ratio is set to 40 to 120%.
In addition, by using a water-redispersible resin powder and a resin aqueous emulsion in combination at a fixed ratio, conventionally, the surface is easily dried and easily cracked, and usually takes about 1 mm repeatedly to apply time and effort, Although it was necessary to apply the coating carefully, it can be easily applied without concern for the thickness. If the P / C ratio is less than 40%, the coating workability is poor, and if it exceeds 120%, the drying property and crack resistance during thick coating are reduced. Although the composition according to the present invention is effective even when applied directly to a substrate, it is selected in consideration of the effect on the substrate material due to the sealing treatment and the preparation of the substrate, and the cement-based coating material. Need to do.

As the hydraulic cement, Portland cement, early-strength cement, blast-furnace cement, silica cement, fly ash cement, white cement, alumina cement and the like can be used alone or in combination.

The inorganic filler in the present invention includes:
Sand, silica sand, silica stone powder, porcelain sand, charcoal, magnesium oxide,
Hemihydrate gypsum, anhydrous gypsum, activated silica, fly ash, cold water, whitebait balloon, expanded silica, dosonite, par
Use light, iron oxide, incinerated ash, pigment, calcium hydroxide, mica, glass powder, etc. Further, those which release water of crystallization at 100 to 400 ° C, such as aluminum hydroxide, magnesium hydroxide, calcium aluminate, gypsum dihydrate, and zinc borate, can also be suitably used. further,
Particles of various stones and the like can be used, but those having a diameter of usually 5 mm or less are preferable. Such an inorganic filler is used in an amount of 100 to 600% by weight, preferably 180 to 400% by weight, based on the hydraulic cement.
% By weight. The usage ratio of such an inorganic filler is 100
When the amount is less than 100% by weight, the spraying workability is reduced and the ratio of the resin is too large, which adversely affects the drying property. When the amount is more than 600% by weight, the film becomes brittle and is not suitable as a coating material. .

In preparing the composition of the present invention, an appropriate amount of water, a thickener, a plasticizer, an antifoaming agent, a dispersant, a film-forming agent and the like are appropriately used as needed. Further, a fiber, an organic extender, a filler, and the like may be appropriately used as needed. Further, when the composition of the present invention is used as a finishing material, it can be appropriately mixed with stone particles, porcelain sand, glaze powder, colored filler, earth, shell particles, crushed material, and the like. Good.

In producing a cement molding using the polymer-cement composition for finishing of the present invention, a decorative mold having a natural rock-like pattern on the inner surface is used. The decorative mold is made of a material such as expanded polystyrene, expanded polypropylene, polyester, urethane rubber, and silicone. Also, on the inner surface of the makeup form,
Polyolefin, polyester, silicone or fluorocarbon resin, enamel, urethane,
The release surface may be formed using a material having a different polarity, such as Teflon, or a so-called liberating agent such as oil, silicone oil, or grease may be applied.

The water-slurried composition of the present invention is sprayed onto the inner surface of the decorative form, applied by a method such as brushing or flowing coating, and dried to form a film. As the work, spraying is the easiest, but the surface is not smooth, but has irregularities, and the corners tend to be thicker, and this part causes cracks as it dries. In addition, if the surface is slightly thick even on a smooth surface, the surface is dried and cracks occur. For this reason, a thickness of 1 mm is usually used as a measure of one coating, but the composition of the present invention can withstand a considerably thick coating. Coating is performed evenly or partially on the entire surface, and a method of applying a plurality of things at the same time or performing a plurality of partial coatings is performed. You don't have to wait, you can paint over. These coating films usually have irregularities and roughness easily formed on the side surface of the coating, and are particularly rougher than stone particles or the like. On this side,
Further, the cement-based material which has been made into a water slurry is applied and dried and cured to obtain an integrated cement-based molded product. This is a cement-based molded product with a resin mortar finish layer such as a polished surface on the surface, and has a high P / C ratio.
It has excellent durability.

It is usually good to dry the coating surface of the composition to be the finished surface and apply a cement-based material. However, a considerable amount of force is applied and poured into a decorative mold to cast concrete. If you do, make sure to make a film, but because the film thickness is not so large, it is good to horizontally pour mortar thinly and slowly, and when applying resin mortar, do not particularly stick to film formation A so-called wet-and-wet method may be adopted in which the following is applied before drying, and the resultant is dried by being overlapped. What is a cement-based material?
In the case of a mortar, concrete, or resin mortar concrete, particularly a thin sheet having a thickness of less than 50 mm, a resin mortar is preferred from the viewpoint of strength. When using as mortar, it is better to use mortar or concrete.

In applying the composition of the present invention to a decorative form, spraying is a popular method.
The coating may be performed with a flow coating, an iron, a roller, or the like. Drying may be performed by drying at room temperature or by heating. Further, in the repainting, a concrete is generally cast between the decorative molds, but it may be used as a sheet-like cement-based molded product. The coating thickness of the present composition is 1 to 10 mm, preferably 2 to 5 mm.

[0024]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. Examples 1 to 15 and Comparative Examples 1 to 12 Based on the mixing ratios shown in Tables 1 and 2, an inorganic filler and a water redispersible resin powder were added to a hydraulic cement and mixed. And water were added and kneaded with a mixer to prepare a water-slurry polymer-cement mortar. At this time, the viscosity of the prepared polymer-cement mortar was 3000 to 30000 cps. Then, for the prepared polymer-cement mortar, crack resistance, spraying workability, surface drying property,
And the durability of the coating film was tested. The results are shown in Tables 1 and 2.

Crack resistance The prepared polymer-cement mortar was placed on a 50 × 100 cm decorative mold placed on a polyethylene sheet for 1 m each.
m, 2mm, 3mm, 4mm, 5mm,
Twenty hours later, the film was visually observed and examined for crack resistance. In the table, Δ: no crack Δ: slight crack ×: crack present

Spraying workability Prepared polymer cement mortar is φ5 m on the plate surface of the plate.
Spraying was performed under a pressure of 5 kg / cm ² with a ricin gun of m diameter, and the spraying operability was observed. Table 1 shows the results.
It is also shown in Table 2. In the table, Ο: Uniform atomization and good spraying △: Slightly poor atomization due to poor atomization and occasional stiffness ×: Poor spraying.

Surface Drying Property The prepared polymer cement mortar was applied to a 15 × 15 cm straight plate surface to a thickness of 1 mm, 3 mm and 5 mm, respectively, and the formation of a film on the surface film was observed with a finger. The results are shown in Tables 1 and 2. In the table, Δ: good without film formation Δ: partial film formation but slightly good ×: film formation and poor.

Durability of Coating Film The prepared polymer cement mortar was applied to a 15 × 15 cm straight plate surface to a thickness of 3 mm, allowed to dry naturally for 3 days, and then immersed in water for 3 days to form a coating film. The durability was visually observed. The results are shown in Tables 1 and 2. In the table, Ο: good without change Δ: slightly softened slightly good ×: softened and poor, respectively.

[0029]

According to the present invention, the polymer
By using a water redispersible resin powder and a resin aqueous emulsion together within a specific range, and using a hydraulic cement and an inorganic filler, the durability is improved despite the extremely high P / C ratio. A polymer cement for finishing that is excellent in fresh concrete, resistant to fresh concrete, can be applied thick by spraying, has no cracks, and is very suitable for cosmetics, surface protection and curing. Mortar can be obtained.

Further, the present invention is not only used when the pattern of the decorative form is relatively smooth, but also adapts well to corners, irregularities, complicated shapes, grooves, etc., and always reveals a precise pattern. Thus, it is possible to obtain a cement-based molded product excellent in strength, shape retention, and the like.

[0031]

[Table 1]

[0032]

[Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:26)

Claims (2)

[Claims] 1. A hydraulic cement and a water redispersible resin powder 1.
A polymer consisting of 100 parts by weight and 100 to 250 parts by weight of a resin aqueous emulsion (as a solid content); and an inorganic filler. The total of the polymer is 40 to 120% by weight based on the hydraulic cement, and the inorganic filler is -Is a polymer-cement composition for finishing, characterized in that the amount is from 100 to 600% by weight based on the hydraulic cement. 2. The polymer-cement composition for finishing according to claim 1 is converted into a water slurry, and the slurry is applied to an inner surface of a required mold form which is releasable to form a film. A method for producing a cement-based molded product, wherein a water-slurry-like cement-based material is laminated and molded.