JPH10120967A - Composition for film for covering hydraulic mixture, covering film for hydraulic mixture and treatment of hydraulic mixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition capable of easily controlling the set-retarding part and the set-retardation extent of the surface of a hydraulic mixture and giving a film having excellent handleability by using a polymer having a specific acid value acid value as a main component. SOLUTION: This composition for the production of a film for covering a surface of an uncured hydraulic mixture to retard the setting of the covered surface part is composed mainly of a polymer having an acid value of 60-600 mgKOH/g, preferably 100-200mgKOH/g. The polymer is preferably a copolymer of 10-30wt.% of an α,β-unsaturated carboxylic acid and other unsaturated monomers. The α,β-unsaturated carboxylic acid is preferably (meth)acrylic acid and 30wt.% of the other unsaturated monomer is preferably an ester of a 1-18C monohydric alcohol and (meth)acrylic acid. The glass transition point of the polymer is preferably 20-80 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a film coated with a hydraulic admixture, a film coated with a hydraulic admixture, and a method for treating a hydraulic admixture.

[0002]

2. Description of the Related Art Conventionally, the surface of a hydraulic admixture has been roughened to facilitate post-processing such as joining of concrete, application of a surface finishing material, painting, and the like, and the surface of a hydraulic admixture. In order to form irregularities on the surface and apply a setting retarder to the surface of the uncured hydraulic admixture to delay the curing near the surface of the hydraulic admixture, the uncured portion near the surface There is known a method of washing out and roughening the surface of a hydraulic admixture.

The setting retarder sprayed on the surface of the uncured hydraulic admixture is a water-soluble low-molecular substance exhibiting a large setting retarding effect even in a small amount. It is difficult to delay the desired setting of the desired thickness of the sprayed surface portion to the desired degree, even if the amount of spraying on the specific portion is controlled, because of easy movement. To solve such a problem, Japanese Unexamined Patent Publication No.
JP-A-118960 discloses a method in which a setting retarder is sprayed on the surface of an uncured hydraulic admixture, and then a predetermined depth portion of the surface is stirred. Further, Japanese Patent Application Laid-Open No. 5-98
Japanese Patent No. 604 discloses a method in which a setting retarder having a specific structure is adjusted to a certain concentration and sprayed. However, all of these methods are low in reproducibility in spite of the complexity and strictness required, and the setting retarder flows, so that these methods are applied to an inclined surface or a vertical surface having a non-horizontal inclination. It is very difficult.

[0004] As a method of applying a setting retarder to a non-horizontal surface, Japanese Patent Publication No. 6-51979 and Japanese Patent Application Laid-Open No. 7-300378 disclose a setting retarder for a substrate such as paper or nonwoven fabric or polypropylene. A method using a sheet impregnated with an agent is disclosed. However, even in these methods, the setting retarder simply impregnates the substrate, and thus has the following problems.

[0005] Since the setting retarder impregnated in the sheet is a water-soluble low-molecular substance that exhibits a large setting retarding effect in a small amount, it is easily released too much by permeation of water only by impregnating the base material. It is difficult to control the rate of set retardation by controlling the rate of release to the surface of the uncured hydraulic admixture. If the sheet gets wet with water, the setting retarder will easily elute therefrom, and if it gets wet before use, the intended performance at the time of sheet production will not be exhibited.

[0006] If the base material is polypropylene or the like, it can be reused, but after use, a complicated operation of removing the sheet is required regardless of the material of the base material. on the other hand,
JP-A-61-246460 and JP-A-61-2
No. 46461 discloses a water-soluble sheet containing a cement setting retarder and a water-soluble resin, and having a liquid-impermeable coating formed on the surface thereof in a pattern, and placing the water-soluble sheet on the surface of the mortar layer.
A method for forming an uneven relief pattern is disclosed. Since this sheet is water-soluble and dissolves after use, a complicated operation for removing the sheet is unnecessary. However, since the sheet is water-soluble and easily dissolved in water, it is difficult to handle. Generally, the mortar layer is formed in an environment where it is often exposed to rain outdoors at high humidity, so if the sheet is wetted with water before being placed on the surface of the uncured hydraulic admixture, The sheet dissolves and can no longer be used on the surface of the mortar layer. In addition, since the cement setting retarders contained in the sheet are all low-molecular substances, the above problems cannot be solved.

[0007]

SUMMARY OF THE INVENTION In view of such circumstances, an object to be solved by the present invention is to use a surface treatment of a hydraulic admixture, and to easily determine a portion that delays setting and the degree of the setting delay. It is an object of the present invention to provide a film which can be controlled at a high speed and has excellent handling properties, and a composition used for producing the film.

Another object to be solved by the present invention is to easily control a portion which delays setting and a degree of the setting delay in the surface treatment of a hydraulic admixture.

[0009]

SUMMARY OF THE INVENTION A composition for a film coated with a hydraulic admixture of the present invention comprises a film which coats the surface of the cast uncured hydraulic admixture and delays the setting of the surface portion. It is a composition used for manufacturing and contains a polymer having an acid value of 60 to 600 mgKOH / g as a main component.

[0010] The hydraulic admixture-coated film of the present invention is obtained by forming the above composition into a film. The method for treating a hydraulic admixture of the present invention comprises coating the uncured hydraulic admixture with the film, delaying the setting in the vicinity of contact with the film, curing the admixture, and curing the admixture. This is a method of washing out the non-condensed portion formed on the substrate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The composition for a film coated with a hydraulic admixture The composition for a film coated with a hydraulic admixture of the present invention is used after being coated on the surface of an uncured hydraulic admixture. Is a composition used to produce a film-form setting retarder. This composition has an acid value of 6
It contains a polymer of 0 to 600 mgKOH / g as a main component, and this polymer has a film forming ability.

First, the polymer contained in the film composition (hereinafter, the “polymer contained in the film composition” may be simply referred to as the “polymer for film”) will be described in detail. [Polymer for Film and Production Method Thereof] The polymer for a film is a polymer having an acid group and has an acid value of 60 to 60.
If it is 0 mgKOH / g, the type of the monomer unit constituting the polymer is not particularly limited, but is preferably used in order to obtain a preferable balance between water resistance and appropriate dissolution (disintegration) in alkaline water described later. Is 70-500m
gKOH / g, more preferably 100-300 mgK
OH / g, most preferably 100-200 mg KOH /
g. The acid value of the film polymer is 60 mg KOH /
When the amount is less than g, it is difficult to sufficiently delay the setting of the hydraulic admixture. On the other hand, if it exceeds 600 mgKOH / g, it becomes water-soluble and the water resistance is reduced, and if water such as rain adheres, it is easily dissolved, so that the handleability may be deteriorated. As a specific method of measuring the acid value, for example, the acid value measuring method described in 4.3 of JIS K6901 “Test method for liquid unsaturated polyester resin” can be mentioned. In the method described above, the acid value is measured by dissolving the polymer for a film in a mixed solvent consisting of 7 volumes of toluene and 3 volumes of ethanol. When the polymer for a film is not dissolved in the mixed solvent, an appropriate solvent may be selected and the measurement may be performed using the solvent.

The polymer for film is not particularly limited as long as it is a polymer having the acid value specified above, but is obtained by polymerization of an unsaturated monomer (hereinafter referred to as "polymerization of unsaturated monomer"). Is sometimes referred to as “polymer a”), since the acid value can be easily adjusted and a desired property can be imparted to a film obtained therefrom. As the unsaturated monomer, an α, β-unsaturated carboxylic acid used for obtaining the acid value specified above can be mentioned as an essential component. And other unsaturated monomers copolymerizable with
"Other unsaturated monomers other than the [alpha], [beta] -unsaturated carboxylic acid which can be copolymerized therewith" are sometimes referred to as "other unsaturated monomers". ) And a polymer for film is obtained.

Specific examples of the α, β-unsaturated carboxylic acid include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid and fumaric acid; maleic anhydride, itaconic anhydride and the like. Α, β-unsaturated carboxylic acid anhydrides; and α, β-unsaturated dicarboxylic acid monoesters such as maleic acid monoester, fumaric acid monoester and itaconic acid monoester. The above α,
One kind of β-unsaturated carboxylic acid may be used alone, or two or more kinds may be used in combination.

It is preferable that the α, β-unsaturated carboxylic acid is acrylic acid and / or methacrylic acid, since the flexibility and toughness when formed into a film are improved. Specific examples of other unsaturated monomers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, stearyl methacrylate having 1 to 18 carbon atoms. Ester of monohydric alcohol and acrylic acid or methacrylic acid; vinyl monomer containing nitrile group such as acrylonitrile and methacrylonitrile; vinyl monomer containing amide group such as acrylamide and methacrylamide; hydroxyethyl acrylate, hydroxypropyl Hydroxyl-containing vinyl monomers such as methacrylate; epoxy-containing vinyl monomers such as glycidyl methacrylate; α, β-unsaturated monomers such as zinc acrylate and zinc methacrylate Metal salts of rubonic acid; aromatic vinyl monomers such as styrene and α-methylstyrene; aliphatic vinyl monomers such as vinyl acetate; halogens such as vinyl chloride, vinyl bromide, vinyl iodide, and vinylidene chloride Maleic acid derivatives such as maleic anhydride, mono- and dialkyl esters of maleic acid; fumaric acid derivatives such as mono- and dialkyl esters of fumaric acid; maleimide, N-methylmaleimide, stearylmaleimide , Maleimide derivatives such as N-phenylmaleimide, N-cyclohexylmaleimide; mono- and dialkyl esters of itaconic acid, itaconic acid derivatives such as itaconamides, itaconic imides and itaconic amide esters; alkenes such as ethylene and propylene; butadiene; Die such as isoprene Mention may be made of a kind, and the like. The other unsaturated monomer may be only one kind, or two or more kinds may be used in combination.

When the other unsaturated monomer is a (meth) acrylic acid derivative such as an alkyl acrylate and / or an alkyl methacrylate, flexibility, toughness, gloss, weather resistance and It is preferable because the film becomes rich in transparency. Further, when the compounding amount is 30% by weight or more of the whole unsaturated monomer used,
It is preferable because flexibility, toughness, gloss, weather resistance and transparency are further increased. Further, when the alkyl acrylate and the alkyl methacrylate are esters of a monohydric alcohol having 1 to 18 carbon atoms and acrylic acid or methacrylic acid, flexibility, toughness, gloss, and weather resistance are further improved. preferable.

It is preferable that the content of the α, β-unsaturated carboxylic acid is not less than 10% by weight of the total amount of the unsaturated monomers, since the solubility of the obtained polymer in alkaline water is sufficient. Furthermore, the mixing ratio of the α, β-unsaturated carboxylic acid is 10 to 30.
It is more preferable that the content by weight be a polymer in which the solubility in alkali water, water resistance and flexibility are balanced.

When the polymer a is a (meth) acrylic polymer which means a polymer in which the proportion of structural units derived from the (meth) acrylic monomer is 50% by weight or more in the polymer, Since (meth) acrylic monomers having various properties can be easily and inexpensively obtained, physical properties such as glass transition temperature and hydrophilicity of the polymer can be controlled, and flexibility of the film can be improved. It is easy and preferable to design the properties, alkali solubility, etc. to the desired performance. In the present invention, the (meth) acrylic monomer means (meth) acrylic acid and / or (meth) acrylate.

The average molecular weight of the polymer for film is not particularly limited.
When it is from 000 to 300,000, it is preferable to form a film to obtain a tough film which is easy to form and tough. In a polymer for a film, its glass transition temperature (hereinafter, the “glass transition temperature” is sometimes simply referred to as “Tg”) is an important physical constant because it is an index of flexibility and flexibility of the film. It is. The Tg of the polymer for a film is not particularly limited, but is preferably −30 to 120 ° C., more preferably 0 to 100 ° C., and more preferably 20 to 80 ° C. from the viewpoint of forming the polymer into a film.
Is most preferred. If the ratio is out of this range, the films may block each other at a high temperature or become brittle at a low temperature or a normal temperature, so that the film may not be wound.

As a specific method of measuring Tg, J
IS K7121 "Measuring method of transition temperature of plastic"
The method described in the above. In this case, 3. The condition of the test piece is adjusted by the method described in (3). The measuring device to be used is not particularly limited. For example, DSC22 manufactured by Seiko Electronics Industry Co., Ltd.
0C type differential scanning calorimeter is mentioned. At the time of reading Tg, if a DSC differential curve obtained by differentiating the DSC curve is used, a peak is seen near Tg, so that reading of Tg becomes easy.

Further, when the composition for a film is a mixture of two or more polymers having different Tg, a high Tg
Is preferable since the polymer component having the above-mentioned properties can maintain the form as a film, maintain appropriate tension, and the like, and the polymer component having a low Tg can achieve the flexibility required for the film. As such a mixture of two or more kinds of polymers having different Tg, a mixture of polymers having two or more Tg between −80 to 130 ° C. is preferable,
0 to 100 ° C., at least one or more T
Further preferred is a mixture of polymers having g.

When the polymer for a film is a polymer further containing a polyvalent metal salt, when formed into a film, the mechanical strength (tensile strength and tear strength) is high, blocking is unlikely to occur, and temperature or humidity changes. It is preferable because it has more stable strength and dimensional characteristics. Specific examples of the polyvalent metal constituting the polyvalent metal salt include group IIa metals of beryllium, magnesium, calcium, strontium and barium; group IIb metals of zinc, cadmium and mercury; boron, aluminum,
Mention may be made of Group IIIb metals of gallium, indium and thallium. Two or more of these polyvalent metals may be used in combination. Among them, at least one of the polyvalent metals selected from the group consisting of magnesium, calcium and zinc
The kind of metal is preferable from the viewpoints of elongation characteristics, water resistance, transparency and economy of the film.

Specific examples of the polyvalent metal salt include magnesium acetate, calcium acetate, zinc acetate, cadmium acetate,
Acetates such as aluminum acetate; carbonates such as magnesium carbonate, calcium carbonate, zinc carbonate, cadmium carbonate, and aluminum carbonate; oxalates such as magnesium oxalate, calcium oxalate, zinc oxalate, cadmium oxalate, and aluminum oxalate Phosphates such as magnesium phosphate, zinc phosphate, cadmium phosphate, and aluminum phosphate; and stearate salts such as magnesium stearate, calcium stearate, zinc stearate, cadmium stearate, and aluminum stearate. .

Among the polyvalent metal salts, magnesium acetate,
Including calcium acetate, zinc acetate, magnesium carbonate, calcium carbonate, zinc carbonate, magnesium stearate, calcium stearate, and zinc stearate is preferred from the viewpoint of film elongation, water resistance, transparency and homogeneity. The polymer for film is the polymer a described above.
In the case of the method, the method for producing the same is a method in which the above-mentioned α, β-unsaturated carboxylic acid is copolymerized with another unsaturated monomer copolymerizable with the α, β-unsaturated carboxylic acid. Although not particularly limited, copolymerization is preferably performed in a non-aqueous system, and examples include solution polymerization in an organic solvent and bulk polymerization. The reason that non-aqueous copolymerization is preferable is that there are restrictions on the monomers that can be used in copolymerization in an aqueous solution, and in aqueous emulsion copolymerization, the polymer is obtained as an emulsion. This is because a complicated operation such as salting out needs to be performed in order to take out from the reaction mixture. Further, generally, the polymer obtained by emulsion polymerization has a very large molecular weight, so that it is difficult to form a film by an extrusion method such as an inflation method or a T-die method, and it is necessary to form a film by a special method. And the cost to make a film is high.

Specific examples of the polymerization method include anionic polymerization, cationic polymerization and radical polymerization, and radical polymerization is preferred. The radical polymerization initiator used in the radical polymerization is not particularly limited, and specific examples thereof include 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile). And azo initiators such as benzoyl peroxide and di-t-butyl peroxide. Two or more of these radical polymerization initiators may be used in combination.

The solvent used in the solution polymerization is not particularly limited as long as it does not hinder the radical polymerization reaction.
Specific examples thereof include alcohols such as methanol, ethanol, and isopropyl alcohol; aromatic hydrocarbons such as benzene and toluene; ketones such as acetone and methyl ethyl ketone; and aliphatic esters such as ethyl acetate and butyl acetate. Can be. Two or more of these solvents may be used in combination.

The reaction vessel used for the production of the polymer a
Any reaction vessel can be used. Specific examples of the reaction vessel include a normal tank reactor, a kneader,
Examples include a tubular reactor such as a static mixer. A plurality of such reactors can be used as needed. Also, a dropping tank is used as needed.

The pressure in the reaction vessel when producing the polymer a may be any of reduced pressure, normal pressure and pressurized pressure. When the polymer a is a polymer having two or more different Tg, the polymer component having a high Tg realizes the maintenance of the form as a film, appropriate tension, and the like, and the polymer component having a low Tg is used as a film. It is preferred because it provides the necessary flexibility. As a method for producing such a polymer a, for example, a plurality of monomer compositions containing an α, β-unsaturated carboxylic acid as an essential component and sometimes containing one or more other vinyl monomers (However, each monomer composition gives a polymer having a different glass transition temperature) by using a multi-stage polymerization step, wherein at least one monomer composition A And a step of polymerizing a part of the remaining monomer composition A and the other monomer composition,
The polymerization system is characterized in that the polymerization is carried out while the mixing ratio is sequentially changed.

As a method for producing the above-mentioned polymer a, for example, the following method I or II is preferable because it can be produced more easily and efficiently. Method I: In the above production method, as a method of sequentially changing the compounding ratio, the monomer composition A was polymerized at a polymerization rate of 20 to 80.
%, And the other monomer composition is further added dropwise or dividedly into the system polymerized to a percentage of 100%. Specifically, another monomer composition B that gives a polymer having a different Tg from the monomer composition A is dropped into a system in which the monomer composition A is polymerized to a polymerization rate of 20 to 80%. The polymerization is further carried out while the other monomer compositions C and D which give a polymer having a different Tg from the monomer compositions A and B are added dropwise or dividedly as needed. Do.

The Tg of the polymer provided by the monomer composition A,
It is preferable that the Tg differs from the polymer provided by the other monomer compositions C and D by 30 ° C. or more, because various physical properties can be obtained. Method II: Monomer composition A and what is Tg
The other monomer compositions B, C, D, etc., which give different polymers, are individually polymerized to a polymerization rate of 20 to 80%, and then individually added in advance to the reaction vessel of the monomer composition A. The polymerization is further performed while the polymerized monomer compositions B, C, D, and the like are added dropwise or dividedly.

In Method II as well as in Method I, the Tg of the polymer provided by the monomer composition A and the Tg of the polymer provided by the other monomer compositions C and D differ by 30 ° C. or more. Is preferable because it can have various physical properties. In both of the methods I and II, it is important to control the polymerization rate. Although the polymerization rate can be determined by any method, there is a simple method using gas chromatography, and the polymerization rate can be determined by quantifying the amount of the remaining monomer.

The distribution of Tg of the polymer a, that is, the shape of the curve obtained by DSC is determined by the balance between the mechanical strength, temperature sensitivity and transparency of the polymer.
In the above methods I and II, if a step of further mixing a polyvalent metal salt is included, the resulting polymer is subjected to metal crosslinking, so that the resulting polymer film has mechanical strength (tensile and tear strength). In addition, the anti-blocking property is further improved, and the material has more stable strength and dimensional stability against changes in temperature or humidity. There is no particular limitation on the polyvalent metal used for metal crosslinking,
For example, the above-mentioned polyvalent metal salts can be mentioned. Preferred examples of the polyvalent metal salt are also the same as those described above.

When the acid value of the polymer for a film of the present invention is low, the dissolution (disintegration) with respect to alkaline water in the hydraulic mixture is slow, and the polymer has a sustained release property. Disintegration) is fast and has quick release. That is, the setting retardation effect can be controlled by adjusting the acid value of the polymer for a film. When a setting retarder other than the polymer for a film is contained in the composition for a hydraulically admixture-coated film described below, the setting retarder is released in accordance with the dissolution (disintegration) of the film. It is also possible to control the release rate of the setting retarder by adjusting.
On the other hand, since a water-soluble resin such as polyvinyl alcohol is simply water-soluble, it is impossible to adjust the dissolution rate (disintegration rate) of the hydraulic mixture in alkaline water. In addition, the non-woven fabric impregnated with the setting retarder only gradually exudes after wetting with water, and it is impossible to control the release rate of the setting retarder. (Hydraulic admixture-coated film composition) The hydraulic admixture-coated film composition of the present invention contains the aforementioned polymer for a film as a main component and coats the surface of an uncured hydraulic admixture. A composition for producing a film, which retards the curing of the surface portion. In addition, it is also possible to use the composition for a hydraulic-mixture-coated film in producing a hydraulic-mixture-coated material other than a film shape.

The hydraulic admixture in the present invention contains water and a material such as cement which hardens with water. The hydraulic admixture contains, for example, cement such as Portland cement and mixed cement and water, and, if necessary, aggregates such as sand and gravel. The cement is mixed with water and kneaded. After that, water gradually hardens due to the hydration reaction, and water is gradually consumed by the reaction. In the case where the unhardened hydraulic admixture contains cement and water, it shows alkalinity.

The polymer for a film is the main component in the composition for a film coated with a hydraulic admixture of the present invention, and its compounding ratio is preferably 50% by weight or more, more preferably 8% by weight or more.
When the content is 0% by weight or more, most preferably 90% by weight or more, it is preferable because the film is tough and the solubility and disintegration in alkaline water are maintained. The composition for a hydraulic admixture-coated film of the present invention may optionally contain, for example, sucrose, lactose, maltose, glucose, fructose, sugars such as glycogen, gluconic acid, ligninsulfonic acid, tannic acid, and humic acid. Acid, organic acids such as glucopeptonic acid and salts thereof, setting retarders such as phosphoric acid, boric acid, silicic acid and other inorganic acids and salts thereof; fillers such as kaolin, asbestos, mica; dioctyl phthalate; Plasticizers such as acetyl tributyl citrate; and components other than film polymers such as lubricants such as stearyl alcohol, stearic acid, stearic acid amide, and calcium stearate may be included.

If the composition for a hydraulically admixture-coated film further contains the above-mentioned setting retarder, the setting retarding effect can be enhanced. Hydraulic admixture-coated film The hydraulic admixture-coated film of the present invention is a film of the composition for a hydraulic admixture-coated film described above,
It is a film-like setting retarder.

The method for producing the hydraulic mixture-coated film is not particularly limited. For example, a) dissolving the composition for a hydraulic mixture-coated film in a solvent, coating the mixture, and then applying the solvent at room temperature or under heating. A method of evaporating water, a so-called casting method, and b) a molding method of hot-melting the composition for a film coated with a hydraulic admixture, forming the film into a film shape, and cooling the film. Above all, the molding method of b) is preferable since a hydraulically-coated admixture-coated film can be produced at a low cost, and when a masterbatch in which a setting retarder, a lubricant, a filler, etc. are dispersed in pellets is used, It is more preferable because additives can be easily mixed therein. As a specific example of the molding method of b), the composition for a film coated with hydraulic admixture is melt-extruded by an extruder.
-Extrusion molding methods such as die molding, inflation molding, blow molding, and laminate molding, and calendering methods and the like. If necessary, the film thus obtained may be further uniaxially or biaxially stretched.

The thickness of the film coated with the hydraulic admixture is not particularly limited, but is usually from 20 to 200 μm. When the thickness of the film is 30 to 100 μm, the workability at the time of using the hydraulically admixture-coated film is good, and it is economical. Hydraulic admixture coated film, if the layer of the pressure-sensitive adhesive is further laminated on the surface of the film, for example, on the surface of the fixed casting mold used to cast the hydraulic admixture It is preferable because the hydraulically coated film can be easily attached. The pressure-sensitive adhesive layer may be formed on one surface or the entire surface of the film, or may be formed on one surface or a part of the entire surface of the film.

Examples of the adhesive include natural rubber-based adhesives, SIS and SBR-based synthetic rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, vinyl acetate-based adhesives,
Examples thereof include polyvinyl alcohol-based adhesives, EVA-based adhesives, urethane-based adhesives, and acrylic-based alkali-soluble adhesives. Above all, if the pressure-sensitive adhesive is an alkali-soluble pressure-sensitive adhesive such as an acrylic resin, there is no need to perform a special operation of removing the layer composed of the pressure-sensitive adhesive after using the hydraulic-mixture-coated film, and the entire film is dissolved. This is preferable because it can be completely removed.

The method for laminating a layer made of an adhesive on the surface of the film is not particularly limited. For example, a hot melt coater, a Revas coater,
It can be obtained by coating with a general coating machine such as a gravure coater or bar coater and then drying. The use of a hydraulic admixture-coated film makes it easy to control the portion that delays setting and the degree of the setting delay. That is, only the covered portion can be reliably and uniformly retarded with a desired strength, and the presence or absence of film coating can be reliably distinguished, so that there is no processing leakage. The acid value of the polymer contained in the film is 600 mg
Since it is KOH / g or less, it has water resistance. Furthermore, since the hydraulic admixture coating material is a film,
Before the hydraulic admixture delays the setting required for the required time, it does not melt or run off when it rains. In addition, as described later, after use, water can be easily removed from the admixture by spraying water or the like, and the handleability is excellent. Method for Treating Hydraulic Admixture Surface The method for treating the hydraulic admixture surface of the present invention is to treat the cast uncured hydraulic admixture with the hydraulic admixture-coated film described above (hereinafter referred to as “hydraulic admixture”). A setting delay step of delaying the setting in the vicinity of contact with the film to cure the admixture by coating the “admixture-coated film” simply with “film”.) A washing step of washing out the formed uncondensed portion.

In the setting retardation step, first, the cast uncured hydraulic admixture is covered with a hydraulic admixture coating film. The uncured hydraulic admixture shows alkalinity, and the hydraulic admixture-coated film is acidic, so that when the film is coated, it gradually dissolves (disintegrates) by the neutralization reaction,
It inhibits the hydration reaction and develops a setting retardation effect. Note that the rate at which the hydraulic-setting admixture-coated film decomposes, the thickness of the uncondensed portion formed near the surface of the uncured hydraulic-setting admixture, and the like are determined by setting the acid value of the polymer contained in the film to 60. It can be changed by appropriately setting in the range of -600 mgKOH / g. Further, since the polymer contained in the film is not a low-molecular substance, it hardly occurs to flow out of the portion other than the coated portion and delay the setting to a portion that does not need to delay the setting.

In order to cause the above-mentioned neutralization reaction, it is preferable to have sufficient moisture. Therefore, when the surface of the uncured hydraulic admixture does not sufficiently contain water, etc., the hydraulic admixture is appropriately added to the hydraulic admixture. Water may be sprinkled before and / or after coating the film. After coating the film, the hydraulic mixture is cured for a certain period of time in order to delay the setting in the vicinity of the uncured hydraulic mixture in contact with the film and to cure the parts other than the vicinity. The method of curing is not particularly limited, and examples thereof include a natural curing method, a steam curing method, and a pressure curing method which are generally known as methods for curing a hydraulic admixture. Curing time is cured to the extent that parts other than near the surface are not easily removed,
There is no particular limitation as long as the time required for the portion where setting has been delayed to be easily removed by uncuring or semi-curing is not particularly limited. For example, in the natural curing method, the time is 8 to 50 hours at room temperature.

The cleaning step is performed as described above.
This is a step of removing an uncondensed portion near the film and a residual film after use. The cleaning step is performed by, for example, spraying a high-pressure cleaning liquid containing water and, if necessary, an emulsifier, or rubbing the non-condensed portion with a rotary brush or the like. In this manner, the surface of the hydraulic admixture is roughened, and post-processing such as joining of concrete, sticking of a surface finishing material, and painting can be facilitated. Also, by cutting the film into the desired shape and placing it in the desired portion of the uncured hydraulic admixture,
The surface of the hydraulic mixture can be modified by forming irregularities on the surface.

[0044]

The film coated with a hydraulic admixture of the present invention is obtained by forming a composition containing a polymer having an acid value as a main component into a film, and has an acid value in the range of 60 mg KOH / g or more. Therefore, when the surface of the cast uncured hydraulic mixture is coated, the neutralization reaction between the acidic film and the alkaline hydraulic mixture inhibits the setting reaction of the hydraulic mixture, and the hydraulic The setting of the admixture is delayed,
Further, since the acid value of this polymer is not more than 600 mgKOH / g, it is not water-soluble but has water resistance.

According to the present invention, since the material exhibiting the setting retardation action is a film, the setting retarding action can be exerted without leakage by covering the casting surface which requires the setting retardation, and the film is covered. A setting retarding action of uniform strength can be exerted on any of the casting surfaces. In the method for treating a hydraulic admixture of the present invention, only the desired portion of the hydraulic admixture can be uniformly retarded by covering only the portion of the hydraulic admixture where the setting is desired to be delayed. Further, by adjusting the acid value of the film, the degree of neutralization reaction between the film and the hydraulic admixture can be changed to control the setting delay time.

[0046]

The following examples are illustrative of the present invention and do not limit the scope of the claims of the present invention. -Example 1-60 g of acrylic acid, 60 g of methyl acrylate, 90 g of ethyl acrylate, and 90 g of methacryl were placed in a glass tank reactor having a capacity of 2 L and equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet tube, and a reflux condenser. 90 g of methyl acid, 65 of methanol
0 g and 0.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged in a nitrogen atmosphere at 65 ° C.
The reaction was performed for 1 hour with stirring. Subsequently, at the same reaction temperature and under stirring, 90 g of acrylic acid and 9 g of methyl acrylate were added.
0 g, a mixture of 135 g of ethyl acrylate and 135 g of methyl methacrylate were evenly dropped in the tank over 2 hours, and simultaneously, 2.4 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added to 100 g of methanol. The dissolved methanol solution was evenly dropped into the tank over 3 hours. After completion of the dropwise addition of the initiator solution, the reaction was continued for another 1 hour under the same conditions for aging to obtain a polymer solution.

The obtained polymer solution was placed in a stainless steel container having a capacity of 2 L, a vacuum pump and a trap were attached to the container, and the solvent was removed by heating in a 200 ° C. oil bath under reduced pressure. Using a CS-194A tabletop extruder of 139 mg KOH / g and a Tg of 5
A film polymer pellet at 5.6 ° C. was obtained. Next, a film was formed using the above-mentioned tabletop extruder to which a film die was attached, to obtain a hydraulically-coated mixture-coated film.

The obtained hydraulic admixture-coated film was adhered to the inside of a plastic container, and 28 parts by weight of ordinary portland cement, 56 parts by weight of Toyoura standard sand,
Mortar consisting of 16 parts by weight of water was injected, and after curing for 3 days, it was demolded, and the portion that could be rubbed off with a finger was rubbed off while washing with water to wash off the setting retardation site. The results are as shown in Table 1.

Example 2 45 g of acrylic acid, 63 g of methyl acrylate, and ethyl acrylate were placed in a 2 L glass tank reactor equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet tube and a reflux condenser. 72 g, methyl methacrylate 120 g, methanol 6
50 g and 0.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged, and a nitrogen atmosphere and 65 ° C.
The mixture was reacted for 1 hour with stirring. Subsequently, a mixture of 67.5 g of acrylic acid, 94.5 g of methyl acrylate, 108 g of ethyl acrylate and 180 g of methyl methacrylate was uniformly dropped in the tank over 2 hours at the same reaction temperature and under stirring. , 2,2'-azobis (2,4
2.4 g of dimethylvaleronitrile) in methanol 10
A methanol solution dissolved in 0 g was uniformly dropped in the tank over 3 hours. After the end of the initiator solution dripping, for aging,
Under the same conditions, the reaction was further continued for 1 hour to obtain a polymer solution. The obtained polymer solution was placed in a stainless steel container having a capacity of 2 L, and a vacuum pump and a trap were attached to the container, and the solvent was removed by heating in a 200 ° C. oil bath under reduced pressure. Using a 194A tabletop extruder, acid value 108 mgKOH / g, Tg 5
A pellet of the polymer for a film at 7.7 ° C. was obtained. Next, a film was formed using the above-mentioned tabletop extruder to which a film die was attached, to obtain a hydraulically-coated mixture-coated film.

The obtained hydraulic admixture-coated film was stuck on the inside of a plastic container, and this container was used for Example 1.
Inject the same mortar as above, cure for 3 days, remove the mold,
While washing with water, the portion that could be rubbed off with a finger was rubbed off to wash off the setting retardation site. The results are as shown in Table 1. -Example 3-30 g of acrylic acid, 75 g of methyl acrylate, 90 g of ethyl acrylate, and 90 g of methacryl were placed in a 2 L capacity glass tank reactor equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet tube, and a reflux condenser. Methyl acid 105g, methanol 6
50 g and 0.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged, and a nitrogen atmosphere and 65 ° C.
The reaction was continued for 1 hour while stirring. Subsequently, a mixture of 45 g of acrylic acid, 112.5 g of methyl acrylate, 135 g of ethyl acrylate and 157.5 g of methyl methacrylate were uniformly dropped in the tank over the course of 2 hours under the same reaction temperature and stirring. , 2,2'-azobis (2,
2.4 g of 4-dimethylvaleronitrile) in methanol 1
A methanol solution dissolved in 00 g was evenly dropped into the tank over 3 hours. After completion of the dropwise addition of the initiator solution, the reaction was continued for another 1 hour under the same conditions for aging to obtain a polymer solution.

The obtained polymer solution was placed in a stainless steel container having a capacity of 2 L, a vacuum pump and a trap were attached to the container, and the solvent was removed by heating in a 200 ° C. oil bath under reduced pressure. Acid value 67 mgKOH / g, Tg 4
Pellets of the polymer for films at 2.0 ° C. were obtained. Next, a film was formed using the above-mentioned tabletop extruder to which a film die was attached, to obtain a hydraulically-coated mixture-coated film.

The obtained hydraulic mixture-coated film was adhered to the inside of a plastic container, and the same mortar as in Example 1 was poured into the container, cured for 3 days, removed from the mold, and rubbed with a finger while washing with water. The portion that could be dropped was scraped off to wash off the setting delay site. The results are as shown in Table 1. -Comparative Example 1-21 g of acrylic acid, 69 g of methyl acrylate, 96 g of ethyl acrylate, and 96 g of methacryl were placed in a 2-L glass tank reactor equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet tube, and a reflux condenser. Methyl acid 114 g, methanol 6
50 g and 0.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged, and a nitrogen atmosphere and 65 ° C.
The mixture was reacted for 1 hour with stirring. Subsequently, at the same reaction temperature and under stirring, a mixture of 31.5 g of acrylic acid, 103.5 g of methyl acrylate, 144 g of ethyl acrylate and 171 g of methyl methacrylate was uniformly dropped in the tank over 2 hours. , 2,2'-azobis (2,
2.4 g of 4-dimethylvaleronitrile) in methanol 1
A methanol solution dissolved in 00 g was evenly dropped into the tank over 3 hours. After completion of the dropwise addition of the initiator solution, the reaction was continued for another 1 hour under the same conditions for aging to obtain a polymer solution.

The obtained polymer solution was placed in a stainless steel container having a capacity of 2 L, a vacuum pump and a trap were attached to the container, and the solvent was removed by heating in a 200 ° C. oil bath under reduced pressure to remove the solvent. Acid value 47 mgKOH / g, Tg 3
A pellet of the polymer for a film at 9.3 ° C. was obtained. Next, a film was formed using the above-mentioned tabletop extruder to which a film die was attached, to obtain a comparative film.

The obtained comparative film was affixed to the inside of a plastic container, mortar was poured into the container, and after curing for 3 days, it was removed from the mold. Washed off. The results are as shown in Table 1. Example 4 A 50 L stainless steel tank reactor equipped with a thermometer, a stirrer, a dropping funnel, a gas inlet tube, and a reflux condenser was provided.
Acrylic acid 0.45kg, ethyl acrylate 2.4k
g, methyl methacrylate 0.15 kg, methanol 3 k
g and 12 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged, and reacted at 65 ° C. in a nitrogen atmosphere with stirring for 20 minutes. Subsequently, under the same reaction temperature and stirring, 1.05 kg of acrylic acid, 2.1 kg of methyl acrylate, 3.85 kg of methyl methacrylate and 7 kg of methanol and 2,2′-azobis (2,4-dimethylvaleronitrile) 28 g of the monomer composition B was uniformly dropped into the reactor over 2 hours, and subsequently polymerization was carried out at 65 ° C. After completion of the dropwise addition, polymerization for aging was further continued at 65 ° C. for 2 hours to obtain a polymer solution.

The obtained polymer solution was desolvated to the exhaust line of the twin-screw extruder under reduced pressure and heated using a devolatilizer equipped with a vacuum pump and a trap, and the acid value was 117 mg KOH.
/ G of polymer for film was obtained. About this resin pellet, DSC2 manufactured by Seiko Denshi Kogyo KK
FIG. 1 shows a DSC curve and a differential curve obtained by measurement using 20C.

As can be seen from FIG. 1, the polymer of Example 4 has two Tg's of 15.8 ° C. and 60.5 ° C. For comparison, the charge ratio of the entire monomer was determined in Example 4.
For the polymer obtained in Example 2 which is identical to the above, the DSC curve and the derivative curve are shown in FIG. 2, which has only one Tg at 57.7 ° C. The resin pellet is formed into a film using an inflation molding device, and the acid value is 1
A 17 mg KOH / g hydraulic admixture coated film was obtained.

[0057] The obtained hydraulic mixture-coated film is stuck on the inside of a plastic container, mortar is poured into the container, cured for 3 days, demolded, and a portion that can be rubbed off with a finger while washing with water is rubbed off. The setting retardation site was washed away. The results are as shown in Table 1. In order to compare the flexibility of the obtained film, the film obtained in Example 2 and the film obtained in Example 4, in which the total monomer charge ratio is the same, were placed in a refrigerator at 7 ° C. 3 in
After standing for 0 minutes, it was folded back 180 degrees. Although the film obtained from Example 4 could be folded, the film obtained from Example 2 was fragile because it was brittle and could not be folded.

-Example 5-Mortar was poured into a plastic container, the surface was covered with a hydraulic-setting admixture-coated film having an acid value of 108 mgKOH / g prepared in Example 2, and after curing for 24 hours, water was removed from the setting retardation site. I rubbed it with my finger while hanging. The laitance layer and the like could be easily washed off, and a uniform rough surface suitable for concrete jointing or the like was obtained.

[0059]

[Table 1]

From the table, it can be seen that, as shown in Examples 1 to 4, when the acid value of the film is increased, the surface of the hydraulic admixture can be set deeper and retarded. Further, Comparative Example 1 has a low acid value and cannot delay the setting of the surface.

[0061]

According to the present invention, the composition for a film coated with a hydraulic admixture can provide a film-like setting retarder. The hydraulic admixture-coated film of the present invention can easily control the portion that delays setting and the degree of the setting delay.
That is, only the covered portion can be reliably and uniformly retarded with a desired strength, and the covered portion and the uncovered portion can be reliably distinguished. Absent. Further, since the acid value of the polymer contained in the film is 600 mgKOH / g or less, the polymer has water resistance and does not become unusable due to melting even when it rains. Moreover, after use, the film dissolves or disintegrates due to the alkali derived from the cement, so that it can be easily removed from the casting surface by spraying water, etc., and is excellent in handleability.

The method for treating the surface of a hydraulic admixture of the present invention comprises:
Since the setting retarder made of a film is used in treating the surface of the hydraulic admixture, it is possible to easily control the portion that causes the setting delay and the degree of the setting delay, and it is easy to clean up after the delay process. .

[Brief description of the drawings]

FIG. 1 is a DSC curve and a differential curve diagram obtained by measuring a resin pellet obtained in Example 4 with a differential scanning calorimeter.

FIG. 2 is a DSC curve and a differential curve diagram obtained by measuring a resin pellet obtained in Example 2 with a differential scanning calorimeter.

[Explanation of symbols]

 1 DSC curve 2 DSC differential curve

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenji Minami 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd.

Claims (7)

[Claims] 1. A composition for coating a surface of an uncured hydraulic admixture to produce a film which retards the setting of said surface portion, comprising a polymer having an acid value of 60 to 600 mg KOH / g. A composition for a film coated with a hydraulic admixture, comprising as a main component. 2. The polymer has a glass transition temperature of -30 to -1.
The composition for a coated film according to claim 1, which is at 20C. 3. The composition for a coated film according to claim 1, wherein the blending ratio of the polymer is 50% by weight or more. 4. The composition for a coated film according to claim 1, wherein the polymer is obtained by polymerization of an unsaturated monomer. 5. The composition for a coated film according to claim 1, wherein the polymer is a (meth) acrylic polymer. 6. A hydraulic admixture-coated film obtained by forming the composition according to claim 1 into a film. 7. An unhardened hydraulic mixture is coated with the film according to claim 6, whereby the setting in the vicinity of contact with the film is delayed so that the mixture is cured and formed in the vicinity. A method for treating a hydraulic mixture, in which the uncondensed portion is washed out.