JPH1053444A - Cement hardening retarder and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively manifest a high ability of a cement hardening retarder to retard the hardening while suppressing elution with water. SOLUTION: This cement hardening retarder has a structure in which a cement hardening retarding component is sealed in an alkali-soluble or an alkali- hydrolyzable polymer. Furthermore, the cement hardening retarder is produced by sealing the cement hardening component (a hydroxycarboxylic acid, etc.) in the alkali-soluble or the alkali-hydrolyzable polymer and is thereby capable of effectively manifesting the ability of the hardening retarding component to retard the hardening. The alkali-soluble polymer includes a homopolymer or a copolymer of (meth)acrylic acid or its salt as a monomer and the alkali- hydrolyzable polymer includes a saturated or an unsaturated polyester or a cured product, etc., of the unsaturated polyester. The dispersion or coating is cited as a sealed form in the cement hardening retarder and the cement hardening retarder may be a powdery or a granular material or a sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cement setting retarder useful for delaying setting of cement and a method for producing the same.

[0002]

2. Description of the Related Art A cement setting retarder is a type of cement admixture used for delaying the hydration reaction of cement and, consequently, the setting and setting of mortar and concrete. As described in JP-A-1-172250, conventional cement setting retarders are roughly classified into two types, inorganic and organic, and as inorganic setting retarders,
Lead oxide, boron oxide, borax, zinc chloride, zinc oxide, magnesium silicofluoride, etc. are used, and as the organic curing retarder, sugar, oxycarboxylate, lignin sulfonate, gluconic acid and its salts, Keto acids such as pyruvic acid and α-ketoglutaric acid are used. And
The purpose of use of these hardening retardants is to cope with long-term transportation of ready-mixed concrete in summer and to relieve thermal stress in large-sized concrete structures.

On the other hand, the surface of concrete molded articles and various structures is often decorated using a so-called washing method, which is one of plastering techniques. This washing method is a method in which the mortar of the concrete surface layer is washed out by washing with water immediately before the cement hardens to expose a part of the aggregate. In this method, the timing of washing out is limited to a very narrow range in terms of time in relation to the hardening speed of concrete, so that it is difficult to mass-produce concrete slabs and apply it to large structures. If the hardening of only the concrete surface layer is inhibited by using a cement setting retarder, which is a kind of concrete admixture, the surface of the concrete product can be decorated regardless of the timing of washing out. Specifically, for example, a paper is impregnated with a curing retarder, and the impregnated paper is fixed to the bottom of the mold by pasting or the like, and then a fresh concrete is poured. After hardening of the concrete, the molded article is detached from the mold, and the uncured mortar on the surface in contact with the impregnated paper is washed away, thereby exposing the aggregate and obtaining a concrete product having a natural texture.

[0004] However, the cement setting retarder is originally a cement (hereinafter, unless otherwise specified, "concrete").
Mortar), and has high solubility in water. When such a cement setting retarder is applied to the above-mentioned washing method, the setting retarder dissolves in the moisture in the concrete when the ready-mixed concrete is poured, and together with the bleed water from the concrete in the formwork or on the surface of the structure. Flow. Therefore, the setting retarder flows to a location where washing is not required, or the curing retarder is locally concentrated in some cases, while the setting retarder flows out at a location where washing is required, and Functions cannot be effectively exhibited. Characters, especially on concrete moldings and structures
When decoration such as a pattern is applied by a washing-out method, it is very difficult to determine a site where the effect of the curing retarder is exhibited.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cement setting retarder capable of suppressing elution by moisture and effectively exhibiting a high setting delay ability, and a method for producing the same. Another object of the present invention is to
An object of the present invention is to provide a cement setting retarder capable of accurately forming a decorative pattern on the surface of a concrete product by a washing method, and a method for producing the same.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and found that when a curing retarder is encapsulated in a hydrolyzable or alkali-soluble polymer, the dissolution of the curing retarder in water is prevented. While it is possible to prevent the hardening delay function and almost lose the setting delay function, on contact with cement mortar, the polymer is hydrolyzed or dissolved due to the strong alkalinity of the cement mortar, and the hardening retarder inside the cement hardens as the hardening of the cement progresses. Leaching or elution was found, and the present invention was completed. That is, the cement setting retarder of the present invention comprises a component having a cement setting delaying ability (hereinafter, may be simply referred to as a setting delay component) and an alkali-soluble or alkali-hydrolyzing agent for encapsulating the cement setting delay component. Consists of molecules and The cement setting delay component includes, in addition to a low molecular weight setting delay component such as oxycarboxylic acid or a salt thereof, a saturated polyester, an unsaturated polyester or a cured product thereof, lignin or a modified product. The polymer may be a saturated or unsaturated polyester, and the unsaturated polyester may be a cross-linked cured product. Further, the polymer may be a homo- or copolymer containing at least (meth) acrylic acid or a salt thereof as a monomer. The encapsulated form of the curing delay component includes dispersion of the curing delay component in the polymer, coating of the polymer with the curing delay component, and the like. The form of the setting retarder may be a granular material, a film or a sheet.
The granules are (1) granules in which a component having a cement setting retarding ability is dispersed in a matrix composed of an alkali-soluble or alkali-hydrolysable polymer, or (2) a component having a cement setting retarding ability. The constituted granular material may be a granular material coated with an alkali-soluble or alkali-hydrolysable polymer, and the film or sheet is composed of (1) an alkali-soluble or alkali-hydrolysable polymer. A film or sheet in which a component having a cement setting retarding property is dispersed in a matrix, or (2) a setting delay layer containing a component having a cement setting delaying property is formed on a base sheet, and the setting delay layer is alkali-soluble or It may be a film or sheet coated with an alkali hydrolyzable polymer. The cement setting retarder can be prepared by encapsulating the setting delay component in an alkali-soluble or alkali-hydrolysable polymer by coating or dispersion. In this specification, “encapsulation” means that the curing retardant is contained in a composition containing at least an alkali-soluble or hydrolysable polymer, and the dissolution of the curing retardant is suppressed. Not all cure retarding components need be completely encapsulated within the composition.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The cement setting retarder of the present invention is a solid
(1) a component having a cement setting delaying ability
(2) With an alkali-soluble or alkali-hydrolysable polymer
And the curing delay component is encapsulated in the polymer.
Having a structure. [Curing delay component] The curing delay component has a relatively high molecular weight.
Low low molecular weight compounds, high including molecular weight in oligomer region
Any of molecular weight compounds may be used. Low molecular weight compounds
And the high molecular weight compound may be used in combination. Low molecular weight
Examples of the organic compound among the curing delay components include, for example, e.
Suhon group PO _ThreeH_TwoPhosphonic acid compound having
For example, aminodi (methylene phosphonic acid), aminotri (me
Tylene phosphonic acid), 1-hydroxyethylidene-1,
1-diphosphonic acid, ethylenediaminetetra (methylene
Phosphonic acid), diethylene triamine penta (methylene
Phosphonic acid), hexamethylenediaminetetra (methyle
Phosphonic acid) or their salts (ammonia, sodium
Alkali metals such as potassium and potassium, calcium and magne
Salt with alkaline earth metals such as calcium and barium)
Non-phosphonic acid compounds [eg, oxycarboxylic acid
Or a salt thereof (glycolic acid, lactic acid, malic acid, tartaric acid,
Citric acid, gluconic acid, oxymalonic acid, mucus acid, hydrid
Roxypropanoic acid, etc.); ascorbic acid, isoasco
Rubic acid, etc .; ketocarboxylic acids (pyruvic acid, ketoglu
Talic acid, etc.); sugars [sucrose, saccharose
Sugars), glucose (glucose) and other polysaccharides and corn
Sugars such as lop]; polyhydric alcohols (pyrogallol,
Gallic acid, 2,4,6-trihydroxybenzoic acid
Etc.); polycarboxylic acids or salts thereof (oxalic acid, malon
Saturated polycarboxylic acids such as acid, succinic acid, and butanoic acid;
Unsaturated polycarboxylic acids such as oleic acid, fumaric acid and itaconic acid
Boric acid, glucoheptanonic acid, etc.). Low
Inorganic compounds among curing delay components of
For example, phosphoric acid or its salt, lead oxide, boron oxide, boric acid or
Is its salt (borax etc.), zinc oxide, zinc chloride, keif
Magnesium iodide, hexafluorosilicate, etc.
Can be These low molecular weight compounds may be used alone or in combination of two or more.
Can be mixed and used. Of the low molecular weight cure retarders, phos
Honic acid compound, oxycarboxylic acid or salt thereof, ketocal
Bonic acid, sugar, polyhydric alcohol, polycarboxylic acid or the like
Salt, phosphate, lead oxide, boron oxide, borate (borax
Etc.), zinc oxide, zinc chloride, magnesium fluorosilicate
Selected from the group consisting of hexafluorosilicate
At least one component is preferred.

As the high molecular weight curing retarding component, a saturated polyester, an unsaturated polyester or a cured product thereof, a homopolymer or a copolymer of a monomer having a carboxyl group or an acid anhydride group or a salt thereof [styrene-maleic acid copolymer] Coalescence, polyacrylic acid, polymethacrylic acid, styrene- (meth) acrylic acid copolymer, (meth) acrylate- (meth) acrylic acid copolymer, ethylenesulfonic acid-acrylic acid copolymer, etc.]; lignin or modified (Eg, ligninsulfonic acid or lignosulfonate (eg, calcium lignosulfonate)). These high molecular weight curing retarding components can be used alone or in combination of two or more. In addition, even if the high molecular weight curing retarding component is an alkali-soluble or hydrolysable polymer for encapsulating the curing retarding component and a compound of the same type in the chemical structure, etc., the presence or difference of the curing retarding performance is different. As long as they are different, high molecular weight cure retarding components
It is used as a component different from the alkali-soluble or hydrolysable polymer for enclosing the curing retarding component. From such a viewpoint, among the high molecular weight curing retardants exemplified above, an anionic group (preferably a carboxyl group) and a hydrophilic group (preferably a carboxyl group) capable of forming a chelate with respect to a divalent metal ion in the molecule. Glycol or a polyglycol such as polyoxyethylene glycol or a glycol having a monoether residue thereof) or a polymer that generates the anionic group and the hydrophilic group upon hydrolysis with an alkali. preferable. More specifically, an unsaturated polyester produced by esterification of a dicarboxylic acid such as maleic acid or fumaric acid with a diol such as ethylene glycol or propylene glycol;
Crosslinked and cured products with a hydrophilic group-containing monomer such as 2-hydroxyethyl (meth) acrylate or polyoxyethylene glycol mono (meth) acrylate, dicarboxylic acids such as maleic acid and fumaric acid, and 2-hydroxyethyl (meth) acrylate Examples thereof include a homopolymer of an ester with a polymerizable monohydroxy compound having a hydrophilic group such as polyoxyethylene glycol mono (meth) acrylate or a copolymer with another copolymerizable compound. Preferred high molecular weight cure retarding components include at least one selected from saturated polyesters, unsaturated polyesters or cured, lignin or modified products thereof. The details of the saturated polyester and the unsaturated polyester will be described later.

[0009] For example, when 0.1% by weight of the setting delay component is added to the cement, the setting delay component is 1.5 times or more the setting time of the cement mortar not added (for example, 1.%). 5 to 100 times), preferably 1.8 times or more (for example, about 2 to 100 times). More specifically, a hardening retarder for Portland cement using ordinary Portland cement, fine aggregate (sand) having a coarse grain ratio of 2.35 and 99% by weight of the whole passing through a 2.5 mm sieve, and water. Mortar composition prepared by kneading at a ratio of 0.1% by weight, a water / cement ratio = 0.50, and a sand / cement ratio = 2.75 with a Hobart mixer for 3 minutes. Setting test 21
In a mortar setting test according to ASTM C403, the setting start time T of mortar to which 0.1% by weight of a cement was added with respect to cement when the test was carried out in a constant temperature chamber at a temperature of 0 ° C.
1 is at least 1.5 times (T = T1 / T0 ≧) the setting start time T0 of the mortar to which no setting retarder is added.
1.5), and preferably 1.8 times or more (T ≧ 1.8). These cure retarding components are usually solid at room temperature in the form of a powder.

[Alkali-Soluble or Alkali-Hydrolysable Polymer] The above-mentioned polymer may be alkali-soluble or alkali-hydrolyzable. Alkali-soluble polymer Examples of the alkali-soluble polymer include polymers having a carboxyl group and a sulfonic acid group. Examples of the alkali-soluble polymer include, for example, carboxymethylcellulose or a salt thereof, alginic acid or a salt thereof, a water-soluble polyester resin having a sulfoisophthalic acid or a salt thereof as a dicarboxylic acid component, an acrylic resin having a carboxyl group or a salt thereof, or styrene. Base resin and the like.

Preferred alkali-soluble polymers include:
For example, a homopolymer or copolymer of a monomer having a carboxyl group or an acid anhydride group, a copolymer of a monomer having a carboxyl group or an acid anhydride group and a copolymerizable monomer,
Alternatively, salts thereof are preferable. Examples of the monomer having a carboxyl group or an acid anhydride group include unsaturated monocarboxylic acids such as (meth) acrylic acid, unsaturated acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and itaconic anhydride. Examples thereof include dicarboxylic acids. These monomers can be used alone or in combination of two or more. As the copolymerizable monomer, for example, acrylic monomers [for example, methyl (meth) acrylate, ethyl (meth) acrylate,
C _1-18 alkyl (meth) acrylates such as butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) Hydroxyl-containing (meth) acrylates such as acrylate and 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, etc.], allyl ether monomers, aromatic vinyl monomers [styrene, α-methylstyrene, vinyltoluene] Etc.], vinyl ester monomers [vinyl acetate, vinyl propionate, etc.], vinyl ether monomers [methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, etc.]. Examples of the salt of the alkali-soluble polymer include salts with an inorganic base [eg, an alkali metal such as ammonia, sodium, and potassium] and an organic base [eg, methylamine, trimethylamine, triethylamine, ethanolamine, and morpholine].

The amount of the monomer having a carboxyl group or an acid anhydride group is selected from the range of 5 to 100% by weight, preferably 10 to 80% by weight, particularly about 15 to 50% by weight of the whole monomer. it can. Although the acid value of the alkali-soluble polymer is not particularly limited, a copolymer of a monomer having a carboxyl group or an acid anhydride group and another copolymerizable monomer is usually, for example, 20 to 300 mgKOH / g. And preferably about 50 to 250 mgKOH / g.

Specific examples of the alkali-soluble polymer include:
For example, styrene-maleic acid copolymer, polyacrylic acid, polymethacrylic acid, styrene- (meth) acrylic acid copolymer, (meth) acrylate- (meth) acrylic acid copolymer, vinyl ether-maleic anhydride Copolymers and the like can be exemplified. Preferred alkali-soluble polymers include homo- or copolymers (especially acrylic resins and styrene resins) containing at least (meth) acrylic acid or a salt thereof as a monomer.

The alkali-hydrolysable polymer includes a saturated or unsaturated polyester, and the unsaturated polyester may be a cross-linked cured product of the unsaturated polyester. The polyester resin can be obtained by subjecting a reaction component mainly composed of a glycol component and a dicarboxylic acid component to a dehydration condensation reaction, and the unsaturated polyester resin is at least maleic anhydride (or maleic acid) as the dicarboxylic acid component. ) Can be prepared.

The glycol component includes C _2-6 alkylene glycols such as ethylene glycol, propylene glycol, 1,3-butanediol, tetramethylene glycol, hexanediol and neopentyl glycol; diethylene glycol, triethylene glycol,
Polyethylene glycol (hereinafter, unless otherwise specified,
These are simply referred to as polyethylene glycol), dipropylene glycol, tripropylene xericol,
Examples thereof include polypropylene glycol (hereinafter, simply referred to as polypropylene glycol unless otherwise specified), polyoxyalkylene glycol such as polytetramethylene glycol, and the like. These glycol components may be used alone or in combination.

The dicarboxylic acid component includes, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,
Aliphatic saturated dicarboxylic acids having about 2 to 10 carbon atoms such as azelaic acid and sebacic acid; carbon numbers such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and mesaconic acid 4 ~
About 6 aliphatic unsaturated dicarboxylic acids, phthalic acid, phthalic anhydride, terephthalic acid, aromatic dicarboxylic acids such as isophthalic acid and the like are included. These polycarboxylic acids can be used alone or in combination of two or more.

The saturated or unsaturated polyester resin may be modified with a component other than the glycol component and the dicarboxylic acid component in order to adjust properties such as strength, elongation, flexibility, flexibility and resistance. . For example, instead of part of at least one of the glycol component and the dicarboxylic acid component, a polyhydric alcohol (for example, glycerin, trimethylolpropane, pentaerythritol, etc.), a polyhydric carboxylic acid (for example, trimellitic acid, (E.g., merit acid) can be copolymerized. Phthalic acid, terephthalic acid, polycarboxylic acid component containing an aromatic dicarboxylic acid or a derivative thereof selected from isophthalic acid or a derivative thereof, the strength, elongation of the polyester,
It is useful for adjusting properties such as flexibility, flexibility, and water resistance.

The molecular weight of the saturated or unsaturated polyester resin is not particularly limited.
２５25,000, preferably about 500-15,000.

The crosslinked cured product of the unsaturated polyester resin is
It can be obtained by polymerizing an unsaturated polyester resin alone or a polymerizable composition of an unsaturated polyester resin and a reactive diluent with a polymerization initiator such as an organic peroxide and curing the same. As the reactive diluent, a polymerizable vinyl monomer, for example, a styrene-based monomer such as styrene, an alkyl group such as methyl (meth) acrylate, ethyl (meth) acrylate, or butyl (meth) acrylate having about 1 to 10 carbon atoms is used. Examples include monomers having a functional group such as alkyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, (meth) acrylic acid, and glycidyl (meth) acrylate. One or more of these reactive diluents can be used. The amount of the reactive diluent can be selected according to the desired properties, and is, for example, about 10 to 500 parts by weight, preferably about 25 to 200 parts by weight, per 100 parts by weight of the resin.

Examples of the organic peroxide include methyl ethyl ketone peroxide, cumene hydroperoxide, benzoyl peroxide, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate, dicumyl peroxide. And the like. Curing of the unsaturated polyester resin is possible at room temperature, but in order to cure in a short time (for example, about 0.5 to 50 minutes), it is advantageous to carry out the temperature at about 60 to 200 ° C. In order to promote curing, if necessary, curing accelerators, for example, organic salts of cobalt such as cobalt naphthenate and cobalt octylate, β-diketones such as acetylacetone and ethyl acetoacetate, and aromatic tertiary amines And a mercapto compound may be used in combination.

The proportion of the alkali-soluble or alkali-hydrolysable polymer can be selected according to the desired degree of cure retardation and the form of encapsulation of the cure retardant.
1 to 5000 parts by weight, preferably 10 to 10 parts by weight
It can be selected from the range of 1000 parts by weight, more preferably about 20 to 500 parts by weight.

[Encapsulation form of setting delay component] The cement setting retarder of the present invention only needs to have a structure in which the setting delay component is encapsulated in an alkali-soluble or alkali-hydrolysable polymer. May be either dispersion or coating. For example, (1) a dispersion form in which a curing delay component is dispersed and enclosed in a matrix composed of the polymer, (2) a powder or granule composed of a curing retardation component or an alkali-soluble A coating form coated with an alkali hydrolyzable polymer may be used. In the dispersion form (1), the matrix may be composed of an alkali-soluble or alkali-hydrolysable polymer alone,
It may be composed of a resin composition of an alkali-soluble or alkali-hydrolysable polymer and another polymer. Furthermore, in the coating form (2), the powder or the hardening delay layer may be formed by a hardening delay component alone, or may be formed by a hardening delay component and a binder resin. Further, the binder resin for forming the curing retardation layer may be the alkali-soluble or alkali-hydrolysable polymer.

The other polymer in the dispersion mode (1),
Examples of the binder resin in the coating form (2) include a film-forming resin, for example, a thermoplastic resin [for example, an olefin-based polymer such as polyethylene and polypropylene; polyethylene terephthalate, polybutylene terephthalate, and poly (1,4-dimethylol- Polyesters such as cyclohexane terephthalate); nylon 46, nylon 6, nylon 66, nylon 610;
Polyamides such as nylon 612, nylon 11, and nylon 12; polyvinyl acetate, ethylene-vinyl acetate (E
VA) vinyl ester resins such as copolymers, vinyl acetate-vinyl versatate copolymers (VA-VeoVa);
Saponified products of vinyl ester resins such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer; ethylene-ethyl acrylate copolymer, ethylene- (meth) acrylic acid copolymer; polyvinyl chloride, vinyl chloride-vinyl acetate copolymer Halogen-containing polymers such as polymers, vinylidene chloride-vinyl acetate copolymers, polychloroprene, and chlorinated polypropylene; acrylic polymers such as acrylic resins and styrene- (meth) acrylate copolymers; polystyrene and styrene-acrylic acid Ester copolymer, acrylonitrile-styrene copolymer (AS resin), styrene-butadiene copolymer (SB resin), styrene-butadiene-acrylonitrile copolymer (AB
Styrene-based polymers such as S resin); polycarbonate; cellulose-based polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, cellulose acetate, acetylbutylcellulose, nitrocellulose; natural rubber, chlorinated rubber, hydrochloric acid rubber, butadiene rubber;
Elastomers such as isoprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, butyl rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene-non-conjugated diene rubber, acrylic rubber, chlorosulfonated polyethylene rubber, silicone rubber, urethane rubber; Polymer, etc.] and thermosetting resins [eg, thermosetting acrylic resin, vinyl ester resin, diallyl phthalate resin, epoxy resin, polyurethane resin, urea resin, phenol resin, etc.]. One or more of these resins can be used. The proportion of the other polymer constituting the matrix is 0 to 1000 parts by weight, preferably 0 to 700 parts by weight, more preferably 0 to 500 parts by weight, based on 100 parts by weight of the alkali-soluble or alkali-hydrolysable polymer. You can choose from a range of degrees. The ratio of the binder resin constituting the powder or the hardening delay layer is 0 to 100 parts by weight of the hardening delay component.
To 5000 parts by weight (for example, 0 to 500 parts by weight), preferably 0 to 2500 parts by weight (for example, 0 to 250 parts by weight), more preferably 0 to 1000 parts by weight (for example,
0 to 100 parts by weight). The particle size of the powdery granule composed of the curing retardant is not particularly limited, and can be selected, for example, from a range of about 0.1 μm to 5 mm, preferably 1 μm to 3 mm, and particularly about 5 μm to 1 mm. The cement setting retarder of the present invention includes various additives, for example, pigments, coloring agents such as dyes, ultraviolet absorbers,
It may contain stabilizers such as antioxidants, plasticizers, defoamers, emulsifiers, fillers and the like. Since the cement setting retarder of the present invention is encapsulated by an alkali-soluble or hydrolysable polymer, elution by water can be prevented even when a highly water-soluble setting delay component is used. In addition, since the polymer is dissolved or hydrolyzed by contact with the mortar, the high curing retarding ability of the curing retarding component can be effectively maintained for a long time. In particular, when an unsaturated polyester or the like which exhibits a curing retarding ability by hydrolysis or the like is used as the curing retarding component, the curing retarding ability can be maintained for a long period of time. Therefore, the cement setting retarder of the present invention is useful for forming a desired pattern with high accuracy by washing out, but is used in the same manner as a conventional setting retarder, for example, a long-term hardening of ready-mixed concrete in summer. May be added to mortar or concrete for the purpose of suppressing the occurrence of stress and reducing stress due to temperature in large concrete structures.

[Form of Cement Setting Retarder] The form of the cement setting retarder of the present invention is not limited to (a) powder and granules.
(B) It may be a film or a sheet (hereinafter sometimes simply referred to as a curing retardation sheet). The powder (a)
(A1) Powders and granules formed by a dispersion retarding agent may be used, and the powders of the curing retardant are coated with an alkali-soluble or alkali-hydrolysable polymer. (A2). The shape of the granular material (a) is not particularly limited, and may be, for example, any of an amorphous shape, a spherical shape, an elliptical shape, and a rod shape. The average particle diameter of the powder (a) is, for example, 1 μm to 10 mm, preferably 5 μm.
It can be selected from the range of about μm to 30 mm, especially about 10 μm to 10 mm. The curing retardation sheet (b) may have the encapsulated curing retardation component on at least one surface. For example, (b1) a film or sheet formed of the dispersion-type curing retardant, (b2) A) a curing retardation layer formed on a base film or sheet and comprising a curing retardation component;
A sheet composed of an alkali-soluble or alkali-hydrolysable polymer that covers the curing retardation layer may be used. Matrix resin in former (b1), latter (b2)
It is advantageous to use a resin having a film-forming ability as an alkali-soluble or alkali-hydrolysable polymer in the above.

Further, in the forms (a1), (a2), (b1) and (b2), the alkali-soluble or alkali-hydrolysable polymer may be cured such as a cross-linked and cured unsaturated polyester.

The curing retardation sheet is formed by mixing a pressure-sensitive adhesive or an adhesive (hereinafter, simply referred to as a pressure-sensitive adhesive) into the sheet, applying the pressure-sensitive adhesive, or coating a coating layer composed of an alkali-soluble or alkali-hydrolysable polymer. The sheet may be provided with tackiness or adhesiveness by mixing an adhesive. Further, the adhesiveness is determined by selecting a constituent monomer of an alkali-soluble or alkali-hydrolysable polymer (particularly, selection of a C _2-8 alkyl acrylate) or an alkali-soluble or alkali-hydrolysable polymer (for example, an unsaturated polymer). Polyester) and a soft monomer (particularly, C _2-8 alkyl acrylate) may be provided by copolymerization. Use of a curing retardation sheet to which tackiness has been imparted by an adhesive has a pattern, a figure, or a washout surface formed on its surface, and is useful in producing a concrete product integrally fixed to a decorative material. That is,
The sheet is laid in the form with the adhesive surface facing upward, and the surface side of a plurality of decorative materials such as stones and tiles is arranged on the adhesive surface by adhesive, and the decorative materials are positioned and fixed. Next, the inorganic curable composition is cast into a mold, cured by a conventional curing method such as curing, and the cured molded product is removed from the mold. The uncured composition adhered to the decorative material can be easily removed by washing the surface side (contact surface side with the sheet) of the decorative material with water, pressurized water, a jet stream, or the like, thereby removing the adhesive. Thereby, it is possible to obtain a concrete product (decorative finishing block, precast concrete plate, or the like) on which the cleaned facing material is bonded. If you do not want the cosmetic material to adhere to the adhesive surface of the sheet,
By the washing, the aggregate is exposed and a pattern or a washing surface can be formed.

Further, when a cured retardation sheet provided with tackiness is used, the decorative material is not disposed in the formwork.
A kit sheet in which decoration materials are arranged or arranged in advance on the adhesive surface may be arranged in the mold. For example, a unit tile can be formed by sticking a plurality of tiles as decorative materials continuously or scattered on the adhesive surface in the surface direction. A plurality of tiles are often arranged adjacent to each other (continuously) in the plane direction (for example, the vertical direction, the horizontal direction, and the vertical and horizontal directions) or at intervals. By using such a decorative material kit sheet, there is no need to separately arrange decorative materials in the formwork, and only the decorative material kit sheet produced in a separate process needs to be disposed in the formwork. Efficiency can be increased. As the decorative material, various materials, for example, natural stones such as cobble stone, black stone, iron flat stone, stone materials such as artificial stones, ceramic materials such as tiles, metal materials, glass materials, wood, woven fabrics and the like can be used. The decorative material may be flat, and the tile may be a mosaic tile or a split tile in addition to a normal tile. In the production of a concrete product, if necessary, a reinforcing material such as a reinforcing bar may be provided in the mold to cast the inorganic curable composition.

The decorative material kit film such as the unit tile is useful for producing a decorative finish concrete product such as a precast concrete plate. That is, the decorative material kit sheet is placed on a concrete casting formwork with the back surface of the decorative material such as the tiles facing upward, concrete is cast and cured, then the mold is removed, and the adhesive sheet is removed. By exposing the surface of the decorative material and washing the surface of the decorative material with water, the uncured inorganic curable composition (cement, etc.) that has wrapped around the surface of the decorative material is washed away, thereby integrating with the decorative material. Precast concrete boards can be manufactured. That is, even if the inorganic curable composition wraps around the surface side of a decorative material such as a tile, the curing retarder can suppress the curing of the inorganic curable composition, and becomes a non-cured (semi-cured or uncured) state, The surface finish for removing the inorganic curable composition from the surface of the decorative material can be efficiently and completely performed by a simple operation such as washing with water.

In the above-mentioned curing retardation sheet, the curing retardation layer containing a curing retardation component may be peelable from the substrate sheet. When the hardening delay layer can be peeled from the base sheet, the predetermined part or region is cut in accordance with a desired pattern or the like in the hardening delay layer and peeled off from the base sheet, and the sheet is placed in a mold. In order to cope with the non-cutting part of the surface of the concrete product by washing out the contact surface with the sheet in the cured and hardened concrete product by casting the inorganic curable composition (such as mortar composition) A washout surface where a pattern, a graphic pattern, an aggregate, and the like are exposed can be formed at a portion to be washed. The surface of the base sheet may be untreated, for example, may be treated with a release agent such as wax, higher fatty acid amide, silicone oil, etc., in order to make the hardening delay layer peelable. The surface tension of the substrate sheet can be relatively selected in a range that does not impair the releasability of the hardening delay layer, in association with the adhesive strength of the hardening delay layer. The surface tension of the base sheet is, for example, often 38 dyn / cm or less, preferably 20 to 38 dyn / cm, and more preferably about 25 to 36 dyn / cm.

[Manufacturing method] The cement setting retarder of the present invention, by coating or dispersing, sets the setting delay component in an alkali-soluble or alkali-hydrolyzable form, depending on the encapsulated form of the setting delay component and the form of the setting retarder. It can be obtained by encapsulating in a molecule. For example, (1) a cement setting retarder in a dispersed form is prepared by mixing a setting delay component, an alkali-soluble or alkali-hydrolysable polymer, and optionally another polymer, using a conventional device such as a mixer or a kneader. Alternatively, it can be prepared by kneading. In mixing, water or an organic solvent may be used as necessary, and in kneading, the above components may be melt-kneaded. (2) The coating-setting cement setting retarder coats a powder or granule or a setting delay layer composed of a setting delay component and, if necessary, a binder resin with an alkali-soluble or alkali-hydrolysable polymer using a coating apparatus. Can be prepared. In addition, the powder in the form of a coating can be prepared by a conventional method such as fluidized bed coating and microencapsulation.

The cement setting retarder (a) in the form of a powder can be obtained not only by coating the powder but also by pulverizing or classifying the cement setting retarder in a dispersed form. Further, among the curing retardation sheets (b), the curing retardation sheet (b1) formed with the dispersion retardant in the dispersion form
A resin composition composed of a curing retarding component, an alkali-soluble or alkali-hydrolysable polymer, and if necessary, another polymer is formed by a conventional molding method, for example, an extrusion molding method, a casting method, or a calendering method. It can be prepared by forming a film or a sheet by using such a method. The curing retardation sheet (b2) coated with the curing retardation layer is obtained by coating or impregnating a base sheet with a composition containing a curing retardation component and, if necessary, a binder resin, and dissolving the formed curing retardation layer in an alkali-soluble. Alternatively, it can be prepared by coating with a composition containing an alkali hydrolyzable polymer and forming a coating layer. In this method, for application, impregnation or coating, a composition which is heated and melted may be used, or a composition containing water or an organic solvent may be used. Examples of the organic solvent include alcohols such as ethanol and isopropanol; aliphatic hydrocarbons such as hexane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; and halogens such as dichloromethane and dichloroethane. Examples include fluorinated hydrocarbons, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, ethers such as diethyl ether and tetrahydrofuran, and mixed solvents thereof. The composition containing the curing retardant component may be applied to at least one surface of the substrate sheet, and the coating layer may be formed on the entire surface of the substrate sheet, or may be partially (for example, in a regular pattern or irregular pattern). (As a regular pattern).

The base sheet includes, for example, non-porous sheets such as plastic sheets and metal foils, and porous sheets such as paper, woven and non-woven fabrics. Of the base sheets, preferred non-porous sheets include plastic sheets, and porous sheets include nonwoven fabrics. Polymer constituting the base sheet is not particularly limited, for example,
Polyolefins such as polyethylene terephthalate and polybutylene terephthalate (especially polyalkylene terephthalate); ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer; acrylic resin; polystyrene; polyvinyl chloride; Polyamide; polycarbonate;
Examples include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. One or more of these polymers can be used. Preferred substrate sheets include plastic sheets and nonwoven fabrics. The base sheet is
It may be a single-layer sheet or a composite sheet in which a plurality of layers are laminated, such as a laminated sheet in which a sheet made of polyethylene or the like is laminated on one or both sides of a cloth woven with fibers such as polyethylene fibers. You may. The base sheet such as a plastic sheet may be an unstretched sheet or a uniaxially or biaxially stretched sheet. Further, in order to enhance the adhesion, the surface of the base sheet may be surface-treated by a flame treatment, a corona discharge treatment, a plasma treatment or the like. The surface tension of the surface-treated substrate sheet is often about 40 dyn / cm or more. The thickness of the base sheet can be selected within a range that does not impair workability, mechanical strength, and the like.
μm, preferably about 20 to 400 μm, more preferably about 30 to 300 μm, and often about 50 to 300 μm.

The cured retardation sheet may be appropriately cut and used as a surface decoration sheet. For example, on the inner wall or the bottom wall of the formwork corresponding to the washing out part of the concrete product, fix the cut hardening delay sheet by attaching it, cast concrete, and after the concrete has hardened, remove the mold, By washing off the uncured mortar on the surface of the concrete product corresponding to the application site, a decorative finish concrete product can be obtained. In addition, since the setting retardant component is held on the base sheet in a coated form, even when the concrete is cast, the movement of the setting delay component can be suppressed, and the component does not flow due to bleed water. Therefore, of concrete moldings or buildings,
A decorative pattern such as a character or a pattern can be accurately and clearly applied to a desired surface portion.

The cement setting retarder of the present invention may be any of various cements, for example, air-hardened cement (lime such as gypsum, slaked lime and dolomite plaster); Self-hardening cement such as rapid hardening high strength cement and calcined gypsum; lime slag cement,
It can be applied to the suppression of hardening of blast furnace cement and the like; mixed cement). Preferred cements include, for example, gypsum,
Dolomite plaster and hydraulic cement are included. The cement may be used as a paste composition with water (cement paste), or may be used as a mortar composition or a concrete composition containing fine aggregate, coarse aggregate such as sand, silica sand, or pearlite. Good. The paste composition and the mortar composition, if necessary, a coloring agent,
Hardening agents, hardening accelerators such as calcium chloride, water reducing agents such as sodium naphthalene sulfonate, coagulants, thickeners such as carboxymethylcellulose, methylcellulose and polyvinyl alcohol, foaming agents, waterproofing agents such as synthetic resin emulsions, plasticizers, etc. May be included.

The cement setting retarder of the present invention is used for the production of various concrete products, for example, concrete panels such as curtain walls and wall materials, concrete blocks, etc., and particularly for the production of decorative concrete products (for example, precast concrete plates). Useful.

[0036]

According to the cement setting retarder of the present invention, since the setting delay component is encapsulated with a specific polymer, the elution of the setting delay component due to moisture can be suppressed, and the polymer is hardened by dissolution or hydrolysis. High curing retarding ability of the retarding component can be effectively exhibited. In addition, since the outflow of the curing retardant can be suppressed, a decorative pattern can be accurately formed on the surface of the concrete product by the washing out method.

[0037]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 Autoclave equipped with a stirring blade (capacity: 10 liters)
Was charged with maleic anhydride (2396 g), propylene glycol (2543 g) and tetra-n-butyl titanate (2.3 g). Under a nitrogen stream, the contents are stirred and water generated by the reaction is expelled out of the system.
After the temperature was raised to 20 ° C and the mixture was stirred for 2 hours, the temperature was raised to 200 ° C and the mixture was stirred for 7 hours to obtain a number average molecular weight of about 500.
Was obtained. A styrene monomer (450 g) was added to the obtained unsaturated polyester (3000 g).
g), an organic peroxide (70 g) as a curing agent (trade name: Perbutyl O, manufactured by NOF Corporation) and 7 g of cobalt naphthenate as an accelerator were added to obtain a polymerizable composition. 100 parts by weight of granular DL-malic acid (average particle size: 200 μm) was placed in a fluidized bed coating apparatus heated to 110 ° C., and 8 parts by weight of the polymerizable composition at room temperature was sprayed over 3 minutes while flowing. . Further, by heating for 7 minutes, a powder having a hydrolyzable polymer formed on the surface of DL-malic acid (average particle size: 300 μm) was obtained. And mortar (Portland cement /
After pouring sand / water (100/200/55 (weight ratio)), the powder was sprayed over a 5 cm × 20 cm area of the mortar surface. After being left at room temperature for one day, the surface of the mortar was washed with water, and the mortar was washed in the above-mentioned spraying area, and a nearly uniform washed surface having a depth of 4.7 mm was obtained.

Example 2 Maleic anhydride (159.7 g), propylene glycol (169.6 g) and tetra-n-butyl titanate (160 mg) were charged into a reaction vessel, and slowly added under a nitrogen stream.
The temperature was raised to 00 ° C, and the generated water was removed outside the reaction system.
By stirring for an hour, an unsaturated polyester having a number average molecular weight of about 500 was obtained. This unsaturated polyester (50
g), styrene (20 g), an organic peroxide (1.7 g) as a curing agent (trade name: Perbutyl O, manufactured by NOF Corporation), and cobalt naphthenate (1.7) as an accelerator
g) was added to obtain a polymerizable composition. This polymerizable composition (10 g) was added to powdered malic acid (average particle size: 10 μm) (4
The coating solution to which g) was added was applied on a polyethylene terephthalate film to a thickness of 60 μm using a bar coater, and heated at 80 ° C. for 30 minutes to cure the applied layer. Thereafter, the unsaturated polyester is coated on the cured coating layer so as to have a thickness of 20 μm,
The film was obtained by heating at 80 ° C. for 30 minutes and curing. The obtained film was cut into strips of 5 cm × 20 cm, and the pieces were stuck to the bottom of a plastic tray with the coating layer (curing retarder layer) facing upward, and the mortar of Example 1 was poured and left at room temperature for 1 day. When the surface of the mortar was washed out with water, the mortar was properly washed out in accordance with the position and shape of the strip, and a uniform washing surface having a depth of 5.1 mm was obtained.

COMPARATIVE EXAMPLE 1 Maleic anhydride (159.7 g), propylene glycol (169.6 g) and tetra-n-butyl titanate (160 mg) were charged into a reaction vessel, and slowly added under a nitrogen stream.
The temperature was raised to 00 ° C, and the generated water was removed outside the reaction system.
By stirring for an hour, an unsaturated polyester having a number average molecular weight of about 500 was obtained. This unsaturated polyester (50
g), styrene (35 g), an organic peroxide (1.7 g) as a curing agent (trade name: Perbutyl O, manufactured by NOF Corporation), and a cobalt naphthenate (1.7) as an accelerator
g) was added to obtain a polymerizable composition. This polymerizable composition was applied on a polyethylene terephthalate film using a bar coater so that the thickness became 60 μm, and 8
A film was obtained by heating and curing at 0 ° C. for 30 minutes. Then, when the washing depth was measured in the same manner as in Example 2, the washing depth was 1.0 mm.

Comparative Example 2 After the mortar was poured into a plastic tray in the same manner as in Example 1, the granular DL used in Example 1 was placed on this surface.
-0.44 g of malic acid (average particle size 200 µm) in 5 cm
Sprayed over a range of × 20 cm. After one day at room temperature,
When washed out with water, an extremely non-uniform washing surface of 0 to 8 mm was obtained in the range where the granular malic acid was sprayed, and the washed surface extended in a groove shape from a part of the spray area of the granular malic acid. , The effect of washing out to the side of the tray.

Comparative Example 3 A 5 cm-wide tape coated with an adhesive (Nichiban Co., Ltd.)
(Strong adhesive type for cardboard packaging) 0.17 g of powdered malic acid (average particle size: 10 μm) was evenly dispersed and fixed sufficiently to 20 cm. The tape was stuck on the bottom surface of a plastic tray with the powdered malic acid spray side up, and mortar was cast thereon in the same manner as in Example 2. After standing for one day, the surface of the mortar solids was washed out with water, and the bottom surface had a completely different shape from the tape, and a very uneven depth of the mortar appeared. Had reached.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C08G 63/52 NPD C08G 63/52 NPD // C04B 103: 24

Claims (11)

[Claims] 1. A cement setting retarder having a structure in which a component having a cement setting delay ability is encapsulated in an alkali-soluble or alkali-hydrolysable polymer. 2. The curing retarder according to claim 1, wherein the polymer is a saturated or unsaturated polyester. 3. The curing retarder according to claim 2, wherein the unsaturated polyester is a crosslinked cured product. 4. The curing retarder according to claim 1, wherein the polymer is a homo- or copolymer having at least (meth) acrylic acid or a salt thereof as a monomer. 5. The component having the ability to retard cement setting, wherein the component is oxycarboxylic acid or a salt thereof, ketocarboxylic acid, sugar, polycarboxylic acid, polyhydric alcohol, phosphoric acid or a salt thereof, lead oxide, boron oxide, boric acid or A curing retarder according to claim 1, which is at least one selected from a salt thereof, zinc oxide, zinc chloride, magnesium fluorosilicate and hexafluorosilicate. 6. The component having a cement setting delaying ability is a saturated polyester, an unsaturated polyester or a cured product thereof,
The curing retarder according to claim 1, which is at least one kind of polymer selected from lignin or a modified product thereof. 7. The setting retarder according to claim 1, wherein the component having the ability to delay cement setting is dispersed and encapsulated in a matrix composed of an alkali-soluble or alkali-hydrolysable polymer. 8. The curing retarder according to claim 1, wherein the form of the curing retarder is a granular material, a film or a sheet. 9. A powder or granule in which a component having the ability to retard cement setting is dispersed in a matrix composed of (1) an alkali-soluble or alkali-hydrolysable polymer, or (2) a cement setting delay 9. The curing retarder according to claim 8, wherein the powder comprising the functional component is a powder coated with an alkali-soluble or alkali-hydrolysable polymer. 10. A film or sheet in which a component having the ability to retard cement setting is dispersed in a matrix composed of (1) an alkali-soluble or alkali-hydrolysable polymer, or (2) a base sheet The curing retarder according to claim 8, wherein a curing retarding layer containing a component having a cement curing retarding ability is formed thereon, and the curing retarding layer is a film or sheet coated with an alkali-soluble or alkali-hydrolysable polymer. . 11. A method for producing a cement setting retarder in which a component having a cement setting delay ability is encapsulated in an alkali-soluble or alkali-hydrolysable polymer by coating or dispersion.