JP2022023318A - Method for manufacturing cement composition - Google Patents

Abstract

To provide: a method for manufacturing a cement composition which is capable of ensuring a longer usable life and is excellent in self-standing and strength development; and an additive manufacturing method for a molded article (structure) using an obtained cement composition.SOLUTION: A method for manufacturing a cement composition includes: obtaining a flowable composition, whose flow value measured according to a flow test measuring method prescribed in JIS R-5201 is 135 mm or more, by blending a dispersant (A) having an anionic functional group into a cement material and by kneading them together; and, after 10 minutes or more from termination of the kneading, blending a polymer (B) having a cationic functional group into the flowable composition.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a cement composition, and more particularly to a method for producing a cement composition, an additional production method for a modeled product using the composition, and a cement dispersant set for additional production.

As a method for dramatically improving productivity in the construction industry, in recent years, additional manufacturing (3D printing) technology for producing an arbitrary three-dimensional shape by additional lamination that extrudes materials and repeats lamination has developed, and this technology is applied to cement materials. Cases have been reported. This technology does not require a formwork and can quickly and accurately manufacture complex shapes. In addition to shortening the construction period and saving labor by reducing or omitting scaffolding and formwork, the conventional formwork method It may lead to the realization of new structural methods such as a composite structure consisting of three-dimensionally intersecting cross sections and a lightweight cross section, which have been difficult.

When this technology is classified, stereolithography (a method of curing and laminating ultraviolet curable resin one layer at a time), inkjet method (a method of irradiating ultraviolet rays while injecting ultraviolet curable resin from a printer head and laminating), and powder. Sekko modeling (method of spraying resin or glue from the printer head to harden powder sekko), powder sintering modeling (method of baking resin or metal powder with a laser and laminating), Fused Deposition Modeling (melting with heat from a thin nozzle) A method of extruding and laminating the obtained thermoplastic resin) is known. The shaped body is mainly made of resin, gypsum, and metal, and the technology for making a large shaped body such as a construction member using cement material is being studied overseas rather than domestically. Already, in Europe, the United States and China, large-scale models at the level of single-family homes are being manufactured as automatic construction machines.

For example, as a three-dimensional modeling technique using a cement material, Patent Document 1 states that three-dimensional data created by a computer is cut to a predetermined thickness to create two-dimensional slice data, and a spray nozzle is used as two-dimensional slice data. While controlling the movement in the vertical and horizontal directions based on ) A technique for forming a solidified layer having a shape based on two-dimensional slice data by spraying on the sprayed mortar and self-curing the sprayed mortar, and repeating the forming work of the solidified layer to sequentially stack them in the vertical direction is disclosed. ing. Patent Document 2 describes a material for making a mold for manufacturing a casting with a 3D printer, and discloses a material consisting of cement, sand, and a water-soluble silicate as an accelerator. Patent Document 3 shows that fine three-dimensional modeling is possible by an additional manufacturing system for modeling in which the flow value of the cementum kneaded product after vibration is 150 to 220 mm. Patent Document 4 describes a method for producing a hardened cementum, which comprises forming a resin mold by molding with a 3D printer and filling the mold with a cementic material to manufacture a hardened cementum. Is disclosed. Patent Document 5 describes an additional manufacturing method including a step of kneading a cement composition for modeling and water and an extrusion step of extruding and hardening the cement composition. US Pat. A method is described in which stable production can be achieved by pressure extrusion even if the amount is reduced. Patent Document 6 contains a thickener, a setting retarder, an amorphous calcium aluminosilicate, gypsum, and short fibers in addition to a lignin sulfonic acid-based and melamine sulfonic acid-based dispersant. It is stated that a cementitious material for modeling can be obtained.

Japanese Unexamined Patent Publication No. 10-235623 U.S. Pat. No. 821226 JP-A-2017-185645 Japanese Unexamined Patent Publication No. 2016-101737 Japanese Unexamined Patent Publication No. 2018-122539 Japanese Unexamined Patent Publication No. 2018-140906

Patent Document 1 has a problem that the finishability of the modeled body is deteriorated and dust is generated. Since Patent Document 2 uses a water-soluble silicate as an accelerator, there is a problem that the curing speed is slow and the strength development may be inferior. Patent Document 3 has a problem that since the cementum kneaded product solidifies over time, there is a great limitation on the pot life of the cementum kneaded product. Since Patent Document 4 requires the production of a mold, there is a problem that a hardened cementum product, which is a molded product, cannot be efficiently produced. Patent Document 5 secures extrusion moldability by forcibly pressurizing a hydrated cementum kneaded product, but there is a problem that additional production cannot be carried out when hydration further progresses due to aging. .. Patent Document 6 has a problem that the usable time of a cementitious material is limited and the workability is deteriorated.

In view of the above problems, the present invention relates to a method for producing a cement composition which can secure a long-term pot life and is excellent in self-reliance and strength development, and a modeled product (structure) using the obtained cement composition. ) Is an object to be provided.

As a result of various studies to solve the above problems, the present inventor fluidized the flow with a dispersant having an anionic functional group and measured the flow according to the flow test measurement method specified in JIS R-5201. It is suitable for an addition manufacturing method by including at least a step of preparing a fluid composition having a value of 135 mm or more and a step of adding a polymer having a cationic functional group as a post-additive after 10 minutes or more after fluidization. It was confirmed that the cement composition could be prepared, and it was found that the above-mentioned problems could be solved by this, and the present invention was completed.
That is, the present inventors provide the following [1] to [8].
[1] Step 1-1: The dispersant (A) having an anionic functional group is blended and kneaded in the cement material, and the flow value measured according to the flow test measurement method specified in JIS R-5201 is 135 mm or more. Obtaining a fluid composition and
Step 1-2: A method for producing a cement composition, which comprises blending the polymer (B) having a cationic functional group with the fluid composition 10 minutes or more after the completion of the kneading.
[2] The method according to [1], wherein the (A) comprises one or more selected from the group consisting of a lignin sulfonic acid-based compound, a naphthalene sulfonic acid-based compound, and a polycarboxylic acid-based compound.
[3] The method according to [1] or [2], wherein the (B) contains a polymer having an ammonium salt.
[4] The method according to any one of [1] to [3], wherein the amount of the solid content added in (B) is 1 to 1000% by weight with respect to the amount of solid content added in (A).
[5] The method according to any one of [1] to [4], further comprising blending a thickener (C).
[6] The method according to any one of [1] to [5], wherein the cement composition is for addition production.
[7] Step 2-1: The dispersant (A) having an anionic functional group is blended and kneaded in the cement material, and the flow value measured according to the flow test measurement method specified in JIS R-5201 is 135 mm or more. Obtaining a fluid composition,
Step 2-2: The flow composition is supplied to an extrusion addition manufacturing apparatus provided with a pressure feed pipe, and Step 2-3: The polymer (B) having a cationic functional group is blended into the flow composition and then obtained. A method for additionally manufacturing a modeled product, which comprises extruding the cement composition to be obtained from a nozzle at the tip of the pumping pipe.
[8] Additive (A): Dispersant having an anionic functional group and
Post-additive (B): A cement dispersant set for addition production comprising at least a polymer having a cationic functional group.

By the manufacturing method of the present invention, a long-term pot life can be secured, and the product has excellent independence and strength development, the waiting time until curing is shortened, and a modeled body can be easily manufactured in additional manufacturing. Can produce cement compositions that can be constructed.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof. In the present specification, when the term "AA to BB" is used, it means AA or more and BB or less.

[1. Cement composition]
The raw material of the cement composition contains at least the following (A) and (B), and may further contain (C).

[1-1. (A): Dispersant]
(A) is a dispersant having an anionic functional group. By adding (A), cement can be fluidized.

The anionic functional group may be any functional group that takes the form of an anion in water. For example, a hydroxyl group, a carboxyl group, a sulfo group (sulfonic acid group), a phosphoric acid group, a phenolic hydroxide and the like can be mentioned, and a carboxyl group and a sulfo group are preferable. The anionic functional groups in the dispersant can be quantitatively and qualitatively observed by instrumental analysis such as NMR and IR.

Examples of the dispersant containing an anionic functional group include a lignin sulfonic acid-based compound, a naphthalene sulfonic acid-based compound, and a polycarboxylic acid-based compound. Each of the exemplified dispersants will be described in order.

[1-1-1. Ligno sulfonic acid compound]
The lignin sulfonic acid-based compound is a compound having a skeleton in which the carbon at the α-position of the side chain of the hydroxyphenyl propane structure of lignin is cleaved and a sulfo group is introduced. The structure of the skeleton portion is shown in the equation (1).

The lignin sulfonic acid-based compound may be a modified product of a compound having a skeleton represented by the above formula (1) (hereinafter, also referred to as “modified lignin sulfonic acid-based compound”). The modification method is not particularly limited, but a method for chemically modifying such as hydrolysis, alkylation, alkoxylation, sulfonate, sulfonic acid esterification, sulfomethylation, aminomethylation, and desulfonatement; lignin sulfonic acid-based compounds are limited. An example is a method of fractionating the molecular weight by external filtration. Of these, as the chemical denaturation method, one or more reactions selected from hydrolysis, alkoxylation, desulfonation and alkylation are preferable.

The lignin sulfonic acid-based compound can take the form of a salt. Examples of the salt include a monovalent metal salt, a divalent metal salt, an ammonium salt, and an organic ammonium salt. Of these, calcium salt, magnesium salt, sodium salt, calcium / sodium mixed salt and the like are preferable.

The method and origin of the lignin sulfonic acid-based compound are not particularly limited, and any natural product or synthetic product can be used. The lignin sulfonic acid-based compound is one of the main components of the waste liquid of sulfite pulp obtained by evaporating wood under acidic conditions. Therefore, a lignin sulfonic acid-based compound derived from sulfite pulp waste liquid can also be used.

Since the lignin sulfonic acid-based compound (modified lignin sulfonic acid-based compound) is abundantly contained in the commercially available product, such a commercially available product may be used in the present invention. Examples of commercially available products include Vanillex HW (manufactured by Nippon Paper Industries), Sun Extract M (manufactured by Nippon Paper Industries), Pearllex NP (manufactured by Nippon Paper Industries), and Sunflow RH (manufactured by Nippon Paper Industries).

[1-1-2. Naphthalene sulfonic acid compound]
Examples of the naphthalene sulfonic acid-based compound include a naphthalene sulfonic acid formalin condensate. The naphthalene sulfonic acid formalin condensate can be obtained by sulfonated naphthalene with concentrated sulfuric acid and then polycondensing with formaldehyde.

[1-1-3. Polycarboxylic acid compounds]
The polycarboxylic acid compound may be a polymer having a carboxyl group. The morphology of the polymer is not limited, but the following are exemplified.
Poly (meth) acrylic acid (co) polymer obtained by polymerizing (meth) acrylic acid;
A component (a) which is at least one of a copolymer of a polyalkylene glycol mono (meth) acrylic acid ester compound and a (meth) acrylic acid compound and a salt thereof, and a polyalkylene glycol mono (meth) allyl ether system. A component (b) which is at least one selected from the group consisting of a copolymer of a compound and maleic anhydride, a hydrolyzate thereof, and a salt thereof, and a polyalkylene glycol mono (meth) allyl ether-based compound. A composition comprising a (c) component which is at least one of a copolymer of a polyalkylene glycol-based compound with a maleic acid ester and a salt thereof (see, for example, JP-A-7-267705);
A component, which is a component composed of a polyalkylene glycol ester of (meth) acrylic acid and a copolymer of (meth) acrylic acid (salt), and a component B, which is a component composed of a specific polyethylene glycol polypropylene glycol-based compound. A composition composed of a component C, which is a component composed of a specific surfactant (see, for example, Japanese Patent No. 2508113);
Polyethylene (propylene) glycol ester of (meth) acrylic acid or polyethylene (propylene) glycol mono (meth) allyl ether, (meth) allyl sulfonic acid (salt), and (meth) acrylic acid (salt). A vinyl copolymer containing a unit (see, for example, Japanese Patent Application Laid-Open No. 62-216950);
A water-soluble vinyl copolymer obtained by polymerizing a polyethylene (propylene) glycol ester of (meth) acrylic acid, a (meth) allylsulfonic acid (salt), and a (meth) acrylic acid (salt) in an aqueous solution (for example, JP-A-Pri). 1-2267757 (see);
Common obtained from polyethylene (propylene) glycol ester of (meth) acrylic acid, (meth) allylsulfonic acid (salt) or p- (meth) allyloxybenzenesulfonic acid (salt), and (meth) acrylic acid (salt). Polymer (see, for example, Japanese Patent Publication No. 5-36377);
Copolymers having monomeric units formed from polyethylene glycol mono (meth) allyl ether and maleic acid (salt) (see, for example, JP-A-4-149056);
Structural unit derived from polyethylene glycol ester of (meth) acrylic acid, structural unit derived from (meth) allylsulfonic acid (salt), structural unit derived from (meth) acrylic acid (salt), alkanediol mono (meth) A graft composed of a structural unit containing a polymer block obtained by radically polymerizing an α, β-unsaturated monomer having an amide group in the molecule, which is derived from acrylate or polyalkylene glycol mono (meth) acrylate. Polymer (see, for example, JP-A-5-170501);
Polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) acrylate, (meth) acrylic acid alkyl ester, (meth) acrylic acid (salt), and (meth) allyl sulfonic acid (salt) or p- (meth) A water-soluble vinyl copolymer obtained by subjecting an allyloxybenzene sulfonic acid (salt) to an aqueous radical copolymerization (see, for example, JP-A-6-191918);
Polyethylene glycol monoallyl ether, maleic acid-based monomers, and copolymers obtained by using monomers copolymerizable with these monomers (see, for example, Japanese Patent Publication No. 58-38380);
Polyalkylene glycol mono (meth) acrylic acid ester-based monomers, (meth) acrylic acid-based monomers, and copolymers obtained by using monomers copolymerizable with these monomers are alkaline. Copolymer obtained by neutralizing with a substance (see, for example, Japanese Patent Publication No. 59-18338);
A polymer obtained by using a polyalkylene glycol (meth) acrylic acid ester having a sulfonic acid group and, if necessary, a monomer copolymerizable with the polyalkylene glycol (meth) acrylic acid ester, or a polymer obtained by neutralizing this with an alkaline substance ( For example, see Japanese Patent Application Laid-Open No. 62-119147);
Esterification reaction product of a copolymer of alkoxypolyalkylene glycol monoallyl ether and maleic anhydride and a polyalkylene oxide derivative having an alkenyl group at the terminal (see, for example, JP-A-6-271347);
An esterification reaction product of a copolymer of alkoxypolyalkylene glycol monoallyl ether and maleic anhydride and a polyalkylene oxide derivative having a hydroxy group at the terminal (see, for example, JP-A-6-298555);
An alkenyl ether-based monomer obtained by adding ethylene oxide or the like to a specific unsaturated alcohol such as 3-methyl-3-butene-1-ol, an unsaturated carboxylic acid-based monomer, and a copolymerizable with these monomers. Polycarboxylic acid (salt) such as a copolymer composed of a above-mentioned monomer or a salt thereof (see, for example, Japanese Patent Application Laid-Open No. 62-68806).

[1-1-4. Examples other than the above]
(A) is not limited to the above-mentioned example, and may be listed below, for example.
Melamine sulfonic acid formalin condensate;
Polystyrene sulfonate;
Aminosulphonic acid-based compounds such as aminoarylsulfonic acid-phenol-formaldehyde condensate (see, for example, Japanese Patent Application Laid-Open No. 1-113419);

In (A), one type of compounding portion having an anionic functional group may be used alone, or two or more types may be combined.

[1-1-5. Amount of (A)]
The amount of (A) used is preferably 0.01 to 10.0% by weight, more preferably 0.02 to 7.0% by weight, still more preferably 0.05, based on the weight of the cement in terms of solid content. ~ 5.0% by weight. This brings about favorable effects such as reduction of unit water amount, increase of strength, and improvement of durability. When it is 0.01% by weight or more, the dispersion performance can be sufficiently exhibited. On the other hand, if it is within 10.0% by weight, the effect of improving the dispersibility is substantially saturated and reaches a plateau, which can be suppressed from being disadvantageous in terms of economy, and further, curing delay, strength reduction, etc. , It can prevent adverse effects on the properties of mortar and concrete.

[1-2. (B): Polymer having a cationic functional group]
(B) is a polymer having a cationic functional group. The site of the cationic functional group in the polymer may be a main chain, a side chain, or both, and is not particularly limited.

[1-2-1. Examples of polymers with cationic functional groups]
Examples of the cationic functional group include a quaternary ammonium group and an amide group, and a quaternary ammonium group (ammonium salt) is preferable. The polymer usually has a structural unit derived from a monomer having a cationic functional group (preferably an olefinically unsaturated monomer). Examples of the olefinically unsaturated monomer having a cationic functional group include aminoacrylate or methacrylicate ester, vinylpyridine, alkylamino group-containing vinyl ether, and alkylamino group-containing (meth) acrylamide, and details thereof include, for example, N. , N-[(3-Chloro-2-hydroxypropyl) -3-dimethylammoniumpropyl] -methacrylamide chloride (DMAPMA-epi), N- [3-dimethyl-aminopropyl] -methacrylamide hydrochloride (DMAPMA-HCl) ), N- [3- (trimethylammonium) propyl] -methacrylamide chloride (MAPTAC), 2-hydroxy-3-methacryloxypropyl-trimethylammonium chloride, dimethyldiallylammonium chloride (DADMAC), allylammonium chloride (AA), Aziridineethyl methacrylate, morpholinoethyl methacrylate, trimethylammonium ethyl methacrylate chloride, dimethylaminopropyl-methacrylate, [3- (methacryloylamino) propyl] trimethylammonium chloride, 1,2,2,6,6-penta-methylpiperidin methacrylate, amino Propylvinyl ether, diethylaminopropyl ether, t-butylaminoethyl methacrylate can be mentioned. Of these, DMAPMA-HCl, DADMAC, AA, and [3- (methacryloylamino) propyl] trimethylammonium chloride are preferable. The polymer may have two or more structural units derived from a monomer having a cationic functional group, and the number of repeating units and the average molecular weight thereof are not particularly limited.

The polymer having a cationic functional group may further contain a structural unit derived from a monomer having no cationic functional group. Examples of the monomer having no cationic functional group include (meth) acrylic acid, vinyl styrene acid, vinyl toluene styrene acid, unsaturated dibasic acid, hemiesters and salts thereof; α, β-unsaturated amide, vinyl ester, and the like. Vinyl saturated substances, aromatic compounds, vinyl group-containing heterocyclic compounds, vinylidene halides, α-olefins, diallyl phthalates, divinylbenzenes, alkyl acrylates, trimethylolpropane, trimethyl acrylates, α, β-ethylenic unsaturated monomers, ( Meta) acrylate ester; (meth) acrylate ester of the above-mentioned (meth) acrylates and alcohols such as methanol, ethanol, propyl alcohol and butyl alcohol; styrene, α-methylstyrene, o-, m-, p-methylstyrene. , O-, m-, p-ethylstyrene, o, p-dimethylstyrene, o, p-diethylstyrene, isopropylstyrene, o-methyl-p-isopropylstyrene, p-chlorostyrene, p-bromostyrene, o, Examples thereof include styrene derivatives such as p-dichlorostyrene and o, p-dibromostyrene, and may have at least one reactive group other than these, and may be a (co) polymerizable monomer.

As the polymer having a cationic functional group, poly (allylamine), poly (diallyldimethylammonium chloride), and (meth) acrylate-based water-soluble cationic polymer are preferable. The polymer may be a homopolymer, a copolymer, a block polymer, or a graft polymer. The method for producing the polymer may be any ordinary polymerization method and is not particularly limited. It is preferable that the compound having a cationic functional group does not have the property of a cationic surfactant, that is, the property that the hydrophilic group portion of the surfactant does not ionize into positive ions in water.

In (B), one polymer having a cationic functional group may be used alone, or two or more polymers may be used in combination.

[1-2-2. Amount of (B)]
The amount of (B) used is preferably 1 to 1000% by weight, more preferably 5 to 500% by weight, still more preferably 10 to 100% by weight, based on the solid content weight of (A). However, the present invention is not limited to the above range, and can be appropriately adjusted according to the type, amount, and fluidity of the cement composition.

[1-3. (C): Thickener]
(C) is a thickener. By the addition of (C), the pumping property can be improved in the addition manufacturing, and the flexible addition manufacturing becomes possible.

[1-3-1. Example of thickener]
Examples of the thickener include hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose (HEMC), hydroxypropylmethyl cellulose (HPMC), hydroxyethyl ethyl cellulose (HEEC), alginic acid, β-1,3 glucan. , Pullulan, Welan Gum, Xanthan Gum, Gua Gum, Carrageenan, Lactomannan, Pectin, Methyl Stachy, Ethyl Starch, Pryctyl Starch, Methyl Prochyl Starch, Hydroxy Ethyl Starch, Hydroxypropyl Starch, Hydroxypropyl Methyl Starch, Daiyu Tan Gum, etc. One or more selected from saccharides; polysaccharide acid; polyvinyl alcohol; polyethylene glycol and the like can be mentioned, but the present invention is not particularly limited as long as it exhibits a thickening effect when added to each material of the cement composition.

In (C), one type of thickener may be used alone, or two or more types may be combined.

[1-3-2. Amount of (C)]
When (C) is added, the amount used is preferably 0.01 to 5.00% by weight, more preferably 0.01 to 3.00% by weight, and 0, based on the weight of the cement. 3.03 to 1.00% by weight is more preferable. However, the present invention is not limited to the above range, and can be appropriately adjusted according to the type, amount, and fluidity of the cement composition.

[1-4. Other optional ingredients]
The raw material of the cement composition may contain any additive other than the above-mentioned (A) to (C) and the cement material described later. Optional additives include, for example, dispersants (other than (A)), polymer emulsions, air entrainers, cement wetting agents, swelling agents, fungicides, oxycarboxylic acid compounds, retarders, flocculants, drying shrinkage. Ingredients that can be added to cement such as reducing agents, strength enhancers, effect promoters, defoaming agents, AE agents, separation reducing agents, self-leveling agents, rust preventives, colorants, fungicides, and surfactants are listed. Be done. These may be one kind alone or a combination of two or more kinds. More specifically, the following (1) to (11) can be mentioned.

(1) Polymer emulsion:
(Meta) Copolymers of various vinyl monomers such as alkyl acrylates.

(2) Oxycarboxylic acid compound:
Oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof (for example, gluconic acid, glucoheptonic acid, arabonic acid, malic acid, citric acid, and inorganic substances such as sodium, potassium, calcium, magnesium, ammonium and triethanolamine). Salt or organic salt).

(3) Curing retarder other than oxycarboxylic acid compound:
Monosaccharides (eg glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugars), disaccharides, trisaccharides, oligosaccharides (eg dextrin), polysaccharides (eg dextran), at least these Sugars such as sugar compositions containing either (eg, apiose);
Sugar alcohols such as sorbitol;
Magnesium Fluoride;
Phosphoric acid and its salts or boric acids;
Amino carboxylic acid and its salts;
Alkaline-soluble protein;
Humic acid;
Tannic acid;
Phenol;
Polyhydric alcohols such as glycerin; and phosphonic acid, aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), these alkali metals. Phosphoric acids such as salts and alkaline earth metal salts and their derivatives.

(4) Early-strength agent / accelerator:
Soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide;
Chlorides such as iron chloride and magnesium chloride;
Sulfate;
Potassium hydroxide;
Sodium hydroxide;
Carbonate;
Thiosulfate;
Formates such as formic acid and calcium formate;
Alkanolamine;
Alumina cement; and calcium aluminate silicate, etc.

(5) Antifoaming agents other than oxyalkylene type:
Mineral oil-based defoamers such as kerosene and liquid paraffin;
Oil-based defoamers such as animal and vegetable oils, sesame oil, castor oil, and these alkylene oxide adducts;
Fatty acid defoamers such as oleic acid, stearic acid, and these alkylene oxide adducts;
Fatty acid ester defoamers such as glycerin monolithinolate, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, and natural wax;
Alcohol-based defoamers such as octyl alcohol, hexadecyl alcohol, acetylene alcohol, and glycols;
Amide defoamers such as acrylate polyamines;
Phosphate ester defoamers such as tributyl phosphate and sodium octyl phosphate;
Metal soap defoamers such as aluminum stearate and calcium oleate; and silicone defoamers such as dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil. Foaming agent etc.

(6) AE agent:
Resin soap;
Saturated or unsaturated fatty acids;
Sodium hydroxystearate;
Lauryl sulphate, ABS (alkylbenzene sulfonic acid), LAS (linear alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) ether sulfate ester, and salts thereof;
Polyoxyethylene alkyl (phenyl) ether phosphate ester or a salt thereof;
Protein material;
Alkene sulfosuccinic acid; as well as α-olefin sulfonates and the like.

(7) Other surfactants:
Aliphatic monohydric alcohols with 6 to 30 carbon atoms in the molecule, such as octadecyl alcohols and stearyl alcohols;
Alicyclic monohydric alcohol having 6 to 30 carbon atoms in the molecule such as abiethyl alcohol;
A monovalent mercaptan having 6 to 30 carbon atoms in a molecule such as dodecyl mercaptan;
Alkylphenol having 6 to 30 carbon atoms in a molecule such as nonylphenol;
Amines with 6 to 30 carbon atoms in the molecule, such as dodecylamine;
Polyalkylene oxide derivatives in which 10 mol or more of alkylene oxides such as ethylene oxide and propylene oxide are added to carboxylic acids having 6 to 30 carbon atoms in molecules such as lauric acid and stearic acid;
Alkyl diphenyl ether sulfonates in which two phenyl groups having a sulfonic group are ether-bonded, which may have an alkyl group or an alkoxy group as a substituent;
Various anionic surfactants other than the above;
Various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride;
Various nonionic surfactants; and various amphoteric surfactants.

(8) Waterproofing agent:
Fatty acids (salts), fatty acid esters, fats and oils, silicones, paraffins, asphalts, waxes, etc.

(9) Rust inhibitor:
Nitrite, phosphate, zinc oxide, etc.

(10) Crack reducing agent:
Polyoxyalkyl ether etc.

(11) Expansion material:
Etringeite type, coal type, etc.

When any additive is used, the weight ratio (in terms of solid content) between the total of the components (A) to (C) and the arbitrary additive is preferably 1 to 99/99 to 1, and more preferably. It is 5 to 95/95 to 5, more preferably 10 to 90/90 to 10, and even more preferably 20 to 80/80 to 20.

[1-5. Cement material]
Cement materials usually include cement, water and aggregate.

[1-5-1. Cement (hydraulic material)]
The cement composition contains cement as a hydraulic material. Examples of cement include the following.
Portland cement (normal, early-strength, ultra-fast-strength, moderate heat, sulfate-resistant and each low-alkali form);
Various mixed cements (blast furnace cement, silica cement, fly ash cement);
White Portland cement;
Alumina cement;
Ultra-fast-hardening cement (1 clinker fast-hardening cement, 2 clinker fast-hardening cement, magnesium phosphate cement);
Grout cement;
Oil well cement;
Low heat generation cement (low heat generation type blast furnace cement, fly ash mixed low heat generation type blast furnace cement, belite high content cement);
Ultra-high strength cement;
Cement-based solidifying material;
Eco-cement (cement manufactured from one or more of urban waste incinerator ash and sewage sludge incinerator ash).

[1-5-2. Other cement materials]
Examples of cement materials other than cement include the following.
Fine powder (blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder, etc.);
Gypsum (anhydrous gypsum, roasted gypsum, semi-hydrated gypsum, dihydrate gypsum, gypsum plaster, dolomite plaster);
Aggregate (gravel, crushed stone, granulated slag, recycled aggregate, silica stone, clay, zirconite, high alumina, silicon carbide, graphite, chromium, chromog, magnesia and other refractory aggregates, etc.) Such.

[1-5-3. Unit water volume, cement content, water / cement ratio]
The unit water amount is preferably 100 to 185 kg / m ³ , and more preferably 120 to 175 kg / m ³ . The amount of cement used is preferably 200 to 800 kg / m ³ , and more preferably 250 to 800 kg / m ³ . The water / cement ratio (weight ratio) is preferably 0.15 to 0.7, more preferably 0.25 to 0.65. If the unit amount of water is within the above range, thixotropy is high and additive manufacturability is excellent. However, each of the above numerical values is not particularly limited, and can be widely specified from a poor composition to a rich composition depending on the use of the cement composition. That is, the cement composition of the present invention may have a high water reduction rate region, that is, a region having a low water / cement ratio (weight ratio) (for example, 0.15 to 0.5), a large unit cement amount, and water / cement. It is effective for both high-strength concrete with a small cement ratio and poorly mixed concrete with a small amount of cement used (unit amount of cement) (for example, about 300 kg / m ³ or less).

[2. Manufacturing method of cement composition]
The cement composition can be produced by a method including the following steps 1-1 and 1-2.

[2-1. Process 1-1]
Step 1-1 is a step of blending and kneading (A) with a cement material to obtain a fluid composition. In step 1-1, in addition to (A) and the cement material, (C) may be further added if necessary, and any additive may be added. The blending method of each cement material is not particularly limited, and examples thereof include the following (i) to (iii).
(I) A method in which materials other than water are mixed in advance and then water is added and kneaded. (Ii) Fine aggregate and materials other than water are mixed, fine aggregate is added and mixed, and water is further added. Method of kneading (iii) Method of kneading each material at once (C) When adding other additives, the timing of addition of (A) may be the same or different, and is not particularly limited.

The additives (A), (C) and any of the additives may be in the form of liquid or powder, but in terms of their handling, they are preferably in the form of powder when added into the system. Kneading may be performed using a kneading device such as a mixer. Examples of the mixer include any type of mixer used for ordinary mortar and concrete kneading, such as a hobart mixer, a hand mixer, a homogenizer, a swing type mixer, a pan type mixer, and a twin-screw forced kneading mixer. The kneading conditions may be appropriately adjusted so that the flow value of the flow composition A is within the above range.

The flow value of the flow composition is 135 mm or more, preferably 140 mm or more, more preferably 150 mm or more, still more preferably 160 mm or more. If the flow value is less than 135 mm, the fluidity may be low and the pumping property may be inferior. In the present specification, the flow value can be measured for the flow composition immediately after the kneading according to the flow test measurement method specified in JIS R-5201. That is, the flow value when the flow cone specified in JIS R-5201 "Physical test method for cement" is filled with a cementic kneaded product, the flow cone is vertically removed upward, and then the flow is stopped. be. The flow value can be adjusted according to the blending and kneading conditions of each material.

[2-2. Process 1-2]
Step 1-2 is a step of blending (B) with the fluid composition obtained in step 1-1. As a result, the fluidity of the cement composition can be controlled, so that the composition can be designed with a high degree of freedom, and high dispersibility and dispersion retention performance can be obtained even in a wide water reduction rate region. Examples of the compounding method include (B) and (C) used as necessary, a method of adding an arbitrary additive component as it is, and a method of mixing these with a dispersion medium such as water and then adding them. .. When mixing using a device such as line mixing, addition and mixing may be performed at the same time.

The addition time of (B) is usually 10 minutes or more after the end of kneading (after fluidization) in step 1-1. As a result, (A) can be sufficiently adsorbed on a cement material or the like before (B) is added, ensuring long-term pot life, improving autonomy and strength development, and shortening the waiting time until curing. The effects of the present invention such as the above can be further exhibited.

[3. Properties and uses of cement composition]
The flow value of the cement composition is preferably 90 to 250 mm, more preferably 95 to 200 mm, and even more preferably 100 to 200 nm. As a result, it can be continuously extruded from the nozzle of the addition manufacturing apparatus during the addition manufacturing, and the shape retention after modeling is also excellent.

The cement composition is produced under predetermined conditions, and since (B) is added, the fluidity is controlled, and it can have high dispersibility and dispersion retention performance even in a wide water reduction rate region. .. Therefore, the cement composition can be designed with a high degree of freedom in the additional manufacturing application of the modeled product. When the cement composition is further produced using (C), the pumping property can be improved and flexible additional production can be adopted.

[4. Additional manufacturing method of the modeled object]
The addition manufacturing method using the above cement composition may be a method using an addition manufacturing apparatus (for example, an extrusion addition manufacturing apparatus such as a 3D printer), and for example, the following steps 2-1 to 2-3 may be performed. The method of including is mentioned.

[4-1. Step 2-1: Kneading step]
In step 2-1 the dispersant (A) having an anionic functional group is blended and kneaded in the cement material, and the flow value measured according to the flow test measurement method specified in JIS R-5201 is 135 mm or more. Obtain the composition. Step 2-1 may be performed in the same manner as in step 1-1, and a kneading device such as a mixer can be used. However, considering steps 2-2 and subsequent steps, kneading and pressure feeding pump (rotary positive displacement uniaxial eccentric screw pump) It is preferable to use a continuous kneading mixer pump integrated with the above.

[4-2. Process 2-2: Supply process]
In step 2-2, the flow composition is supplied to an extrusion addition manufacturing apparatus provided with a pressure feed pipe. It is preferable that the supply to the device is performed by pumping. Examples of the pump include a squeeze pump and a rotary positive displacement uniaxial eccentric screw pump, and the pump is not particularly limited as long as it can be pumped without deteriorating the quality of the cement composition. Compared to squeeze pumps, rotary positive displacement uniaxial eccentric screw pumps (also called mono pumps or snake pumps) are capable of fixed-quantity pumping without pulsation during pumping, and the extrusion rate can be adjusted by controlling the motor rotation speed. Due to the structure of the rotary positive displacement uniaxial eccentric screw pump, it is considered that the temperature of the cement composition to be pumped tends to rise (as explained later), so that the hardening reaction of the cement composition proceeds in a short time. However, the self-sustaining stability can be improved and the continuous stacking height can be increased.

The rotary positive displacement uniaxial eccentric screw pump usually includes a rotor, a stator, and a cavity, and examples thereof include those having the structure shown in FIGS. 9 and 12 of International Publication No. 2014/142239. The cavity is a gap (sealed space) formed when the rotor is inserted into the stator. An example of material transfer by a pump will be described below. The rotor and stator correspond to male and female threads, respectively. When the material is introduced into the cavity of the pump and the rotor rotates in the stator (usually a reply rotation that revolves around the central axis of the stator and rotates on its axis), the cavity moves to the extrusion side and is strong. A suction force is generated that allows the material to be continuously transferred in the extrusion direction. When the material moves in the cavity by suction in the extrusion direction, it is considered that the material is heated by the frictional resistance with the stator surface. Due to this heating phenomenon, the temperature of the cement composition to be pumped tends to rise, and it is possible to realize three-dimensional modeling having more excellent self-sustaining stability while ensuring the pot life.

The size such as the inner diameter and the length of the pumping pipe is not particularly limited and can be appropriately set depending on the extrusion amount and the like. For example, the inner diameter is preferably 20 to 50 mm, and the length is preferably 20 m or less in consideration of the pumping property. Examples of the material of the pressure feed pipe include a flexible hose (for example, a pressure resistance of 2 to 4 MPa), and a metal pipe may be partially combined, but the material is not particularly limited.

[4-3. Step 2-3: (B) compounding and extrusion step]
In step 2-3, the compound (B) having a cationic functional group is blended into the fluid composition, and the obtained cement composition is extruded from the nozzle at the tip of the pumping pipe. The specific example of (B) and the amount used are the same as those described above. (B) may be added to the flow composition before being extruded from the nozzle, and may be added, for example, to any part of the cavity or in the middle of the pumping pipe. It is preferable that 10 minutes or more have passed from the end of kneading at the time of preparing the flow composition in step 2-1. The reason why 10 minutes or more is preferable is as described in the description of step 1-2 of the method for producing a cement composition. This addition step does not imply dropping, coating, spraying or spraying the polymer onto an already extruded cement composition.

The nozzle is provided at the tip of the pumping pipe. The diameter of the ejection port of the nozzle may be appropriately set depending on conditions such as the size of the aggregate and the stacking size at the time of modeling, and is not particularly limited. For example, when the aggregate diameter is 5 mm or less and the laminated width is 50 mm or less, the diameter of the extrusion port is preferably 8 to 15 mm. The shape of the extrusion port includes, for example, a circle, an ellipse, a rectangle, a cross, and a star, but is not particularly limited. A brim may be provided around the extrusion port. This can impart smoothness to the surface of the extruded cement composition. The extrusion port is often provided in the direction perpendicular to the bed, but may be provided in the horizontal direction.

By controlling the direction and amount of the cement composition extruded from the nozzle, it is possible to additionally manufacture a modeled object. It is preferable that the control of the nozzle movement direction (usually, the horizontal direction (for example, vertical, horizontal, diagonal direction) and the vertical direction) is controlled by a computer. The computer control method will be described below with an example. Using a computer, 2D slice data is created by cutting the 3D data of the planned structure to a predetermined thickness. While controlling the movement of the nozzle (fixed to the robot arm and portal plotter) in the horizontal direction based on the two-dimensional slice data, the cement composition is extruded from the nozzle to the bed and the nozzle is moved in the vertical direction. By repeating this operation and laminating them in sequence, a modeled object can be obtained. The moving speed of the nozzles may be changed depending on the stacking width, and is not particularly limited. When the extrusion amount of the cement composition is constant, the laminating width becomes large when the moving speed of the nozzle is slowed down, and the laminating width becomes small when the moving speed of the nozzle is increased.

The obtained model can be used as, for example, a construction member, a building, a bridge, or a dam.

[5. Cement dispersant set for additive manufacturing]
The above (A) and (B) can be used as a cement dispersant set for additional production of a modeled object. Such a set may further include (C). Each dispersant and polymer may be in a state in which the amount used for one use is contained in a package such as a container or a bag. In addition, a cautionary note describing the usage method such as the time of addition (as described above) may be attached.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and it is possible to carry out the present invention with appropriate modifications within a range that can be adapted to the purpose of the preceding and subsequent descriptions, and all of them can be carried out by making appropriate changes. Included in the technical scope. In the examples, unless otherwise specified, "%" indicates a weight% and "part" indicates a weight part. Further, the measuring method of the physical property value or the like is the measuring method described above unless otherwise described.

[Material used]
(1) Dispersant (1-1) Dispersant having an anionic functional group Lignin 1: Sun extract P252 (powder, modified lignin sulfonic acid, manufactured by Nippon Paper Industries, Ltd.)
Lignin 2: Pearl Rex NP (powder, high-purity lignin sulfonic acid, manufactured by Nippon Paper Industries, Ltd.)
Naphthalene 1: Vaniol HDP100 (powder, naphthalene sulfonic acid formaldehyde condensate, manufactured by Nippon Paper Industries, Ltd.)
Polycal 1: Sika Viscoclete 125 (powder, polycarboxylic acid, manufactured by Sika Japan)

(1-2) Dispersant without anionic functional group PEG1: Polyoxyethylene glycol (powder, weight average molecular weight 10,000, manufactured by Fuji Film Wako)
Cation 1: Poly (allylamine) (20% aqueous solution, weight average molecular weight 15,000, manufactured by MERCK)

(2) Thickener Thickener 1: HM-4000S (hydroxypropyl methylcellulose, manufactured by Sansho Co., Ltd.)
Thickener 2: KELCO-CRETE DG (Daiyu Tan Gum, manufactured by Sansho Co., Ltd.)

(3) Post-additive (3-1) Polymer having a cationic functional group Cation 1: Poly (allylamine) (20% aqueous solution, weight average molecular weight 15,000, manufactured by MERCK)
Cation 2: Poly (diallyldimethylammonium chloride) (35% aqueous solution, weight average molecular weight less than 100,000, manufactured by MERCK)
Cation 3: Poly (diallyldimethylammonium chloride) (20% aqueous solution, weight average molecular weight 200,000 to 350,000, manufactured by MERCK)
Cation 4: Catiomer 300 (40% aqueous solution, (meth) acrylate-based water-soluble cation polymer, manufactured by Sanyo Chemical Industries, Ltd.)

(3-2) Surfactant having a cationic functional group Surfactant 1: Levon TM-16 (30% aqueous solution, cetyltrimethylammonium chloride, manufactured by Sanyo Chemical Industries, Ltd.)

(Examples 1 to 15 and Comparative Examples 1 to 6: Cement composition test)
Cement compositions to which the dispersants, thickeners and samples of Examples 1 to 15 and Comparative Examples 1 to 6 were added were prepared by the following procedure.

At the ambient temperature (20 ° C.), sand (fine aggregate), cement, defoaming agent, and water blended as shown in Table 1 (W / C = 43%), and the amounts shown in Table 2 (solid content conversion). ) Dispersant and thickener were put into a bread-type mixer and kneaded for 120 seconds by mechanical kneading with a bread-type mixer to obtain a cement composition (each sample was put in as a powder). When the dispersant was an aqueous solution, the water in the dispersant was also converted into water in the cement composition and adjusted in advance. Immediately after kneading, 30 minutes and 60 minutes after kneading, the obtained cement composition was subjected to a slump test by the following method, and the amount of air was measured immediately after kneading. The results are shown in Table 2.

However, in Comparative Example 1, in addition to the above-mentioned dispersant and thickener, a polymer having a cationic functional group was added in the kneading step of the cement composition.

<Measurement of flow value> The flow value was measured according to the flow test measurement method specified in JIS R-5201.

<Measurement of air volume> The measurement was performed by the volumetric method calculated from the density of the cement composition.

[Footnotes in Table 1]
C: Equal amounts of the following two types are mixed Ordinary Portland cement (manufactured by Ube-Mitsubishi Cement Co., Ltd., specific density 3.16)
Ordinary Portland cement (manufactured by Taiheiyo Cement, specific density 3.16)
W: Tap water (Iwakuni City)
S: Land sand from Kakegawa (fine aggregate, specific density 2.58)
Defoamer: DF753 (manufactured by Toho Chemical Industry Co., Ltd.)

With respect to the cement composition prepared above, after measurement after 60 minutes of kneading, a polymer having a cationic functional group in the amount (in terms of solid content) shown in Table 2 was added as it was in the form (aqueous solution). After the addition, the cement composition was kneaded with a pan-type mixer for 30 seconds, and immediately after that, the cement composition was subjected to a slump test and an air content measurement by the above method. Further, the settling time and the mortar compressive strength of each of the measured cement compositions were measured by the following methods. The results are shown in Table 2.

<Measurement of condensation time>
The cement composition was stored in a heat insulating container and its temperature was recorded. The time when the temperature reached the maximum temperature was defined as the condensation time at which the mortar was condensed.

<Measurement of compressive strength>
The hydraulic composition prepared in Examples and Comparative Examples was filled into a cylindrical mold having a diameter of 50 mm and a height of 100 mm, left at 20 ° C. for 72 hours, and then demolded to prepare a specimen for compressive strength measurement. The compressive strength was measured using a compression tester according to the JSCE standard JSCE-G 505-1999. Three identical samples were prepared, and the average value of their intensities is shown in Table 2.

[Footnotes in Table 2]
Addition rate (%): Solid content addition rate (% by weight) of each sample to cement
Flow: Mortar flow value (mm)
Addition ratio (%): Solid content addition ratio (% by weight) of the polymer having a cationic functional group with respect to the solid content addition amount of the dispersant contained in the cement composition.

Since the cement compositions of Examples 1 to 12 maintained a high fluidity with a mortar flow of 135 mm or more even 60 minutes after the cement composition was kneaded, the pumping property during additional production was also good. Is expected to be. Further, after adding the polymer having a cationic functional group, the mortar flow becomes 100 to 135 mm, and it can be seen that the mortar flow has high independence. Further, since these cement compositions have low air entrainment, short setting time, and high compressive strength, it can be understood that they are excellent in early curing characteristics and strength development.

According to Examples 13 to 15, it is possible to prepare a cement having an appropriate mortar flow by adding a polymer having a cationic functional group to a fluid composition having high fluidity after 20 minutes of kneading. rice field. Therefore, it can be seen that the timing of addition of the polymer having a cationic functional group can be freely adjusted as long as the cement composition is kneaded after 10 minutes.

On the other hand, in Comparative Example 1, when the polymer having a cationic functional group was added before the kneading of the cement composition, the mortar flow was extremely small, so that it can be seen that there is no pumping property at all. In Comparative Example 2, when a surfactant having a cationic functional group was added, the mortar flow was large, the amount of air entrainment was extremely large, and the compressive strength was also low. Therefore, it can be seen that the surfactant having a cationic functional group is not suitable for the cement composition for addition production. In Comparative Example 3 in which a polymer having a cationic functional group was not used, a cement composition having excellent pumping property could be supplied, but the mortar flow was as high as 150 mm and the fluidity was high, and at the same time, the independence was deteriorated. Further, in Comparative Examples 4 to 6 in which the dispersant having an anionic functional group was not used, the mortar flow after 60 minutes of kneading was small and pumping property could not be expected, and after the addition of the polymer having a cationic functional group, the pumping property could not be expected. This led to an undesired increase in mortar flow, which meant a lack of independence of the cement composition.

The above results show that in the present invention, a cement composition suitable for addition production can be obtained by using both a dispersant having an anionic functional group and a polymer having a cationic functional group.

Claims (8)

Step 1-1: A flow composition in which the dispersant (A) having an anionic functional group is blended and kneaded in a cement material, and the flow value measured according to the flow test measurement method specified in JIS R-5201 is 135 mm or more. Get things and
Step 1-2: A method for producing a cement composition, which comprises blending the polymer (B) having a cationic functional group with the fluid composition 10 minutes or more after the completion of the kneading. The method according to claim 1, wherein the (A) comprises one or more selected from the group consisting of a lignin sulfonic acid-based compound, a naphthalene sulfonic acid-based compound, and a polycarboxylic acid-based compound. The method according to claim 1 or 2, wherein the method (B) comprises a polymer having an ammonium salt. The method according to any one of claims 1 to 3, wherein the amount of the solid content added in (B) is 1 to 1000% by weight with respect to the amount of solid content added in (A). The method according to any one of claims 1 to 4, further comprising blending a thickener (C). The method according to any one of claims 1 to 5, wherein the cement composition is for addition production. Step 2-1: Dispersant (A) having an anionic functional group is blended and kneaded in the cement material, and the flow value measured according to the flow test measurement method specified in JIS R-5201 is 135 mm or more. Getting things,
Step 2-2: The flow composition is supplied to an extrusion addition manufacturing apparatus provided with a pressure feed pipe, and Step 2-3: The polymer (B) having a cationic functional group is blended into the flow composition and then obtained. A method for additionally manufacturing a modeled product, which comprises extruding the cement composition to be obtained from a nozzle at the tip of the pumping pipe. Additive (A): Dispersant having an anionic functional group and
Post-additive (B): A cement dispersant set for addition production comprising at least a polymer having a cationic functional group.