Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
  • C04B24/24—Macromolecular compounds
  • C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C04B24/2641—Polyacrylates; Polymethacrylates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B16/00—Use of organic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of organic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B16/04—Macromolecular compounds
  • C04B16/08—Macromolecular compounds porous, e.g. expanded polystyrene beads or microballoons
  • C04B16/085—Macromolecular compounds porous, e.g. expanded polystyrene beads or microballoons expanded in situ, i.e. during or after mixing the mortar, concrete or artificial stone ingredients
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/0045—Polymers chosen for their physico-chemical characteristics
  • C04B2103/0049—Water-swellable polymers
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/0045—Polymers chosen for their physico-chemical characteristics
  • C04B2103/0057—Polymers chosen for their physico-chemical characteristics added as redispersable powders
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/0045—Polymers chosen for their physico-chemical characteristics
  • C04B2103/0058—Core-shell polymers
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/20—Resistance against chemical, physical or biological attack
  • C04B2111/29—Frost-thaw resistance
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]

Definitions

• the present invention relates to the use of polymeric microparticles in hydraulically setting building material mixtures for the purpose of enhancing their frost resistance and cyclical freeze/thaw durability.
• Concrete is an important building material and is defined by DIN 1045 (07/1988) as artificial stone formed by hardening from a mixture of cement, aggregate and water, together where appropriate with concrete admixtures and concrete additions.
• DIN 1045 07/1988
• One way in which concrete is classified is by its subdivision into strength groups (BI-BII) and strength classes (B5-B55). Adding gas-formers or foam-formers to the mix produces aerated concrete or foamed concrete (Römpp Lexikon, 10th ed., 1996, Georg Thieme Verlag).
• Concrete has two time-dependent properties. Firstly, by drying out, it undergoes a reduction in volume that is termed shrinkage. The majority of the water, however, is bound in the form of water of crystallization. Concrete, rather than drying, sets: that is, the initially highly mobile cement paste (cement and water) starts to stiffen, becomes rigid, and, finally, solidifies, depending on the timepoint and progress of the chemical/mineralogical reaction between the cement and the water, known as hydration. As a result of the water-binding capacity of the cement it is possible for concrete, unlike quicklime, to harden and remain solid even under water. Secondly, concrete undergoes deformation under load, known as creep.
• the freeze/thaw cycle refers to the climatic alternation of temperatures around the freezing point of water.
• the freeze/thaw cycle is a mechanism of damage. These materials possess a porous, capillary structure and are not watertight. If a structure of this kind that is full of water is exposed to temperatures below 0° C., then the water freezes in the pores. As a result of the density anomaly of water, the ice then expands. This results in damage to the building material. Within the very fine pores, as a result of surface effects, there is a reduction in the freezing point. In micropores water does not freeze until below ⁇ 17° C.
• Valenza Methods for protecting concrete from freeze damage, U.S. Pat. No. 6,485,560 B1 (2002); M. Pigeon, B. Zuber & J. Marchand, Freeze/thaw resistance, Advanced Concrete Technology 2 (2003) 11/1-11/17; B. Erlin & B. Mather, A new process by which cyclic freezing can damage concrete—the Erlin/Mather effect, Cement & Concrete Research 35 (2005) 1407-11].
• a precondition for improved resistance of the concrete on exposure to the freezing and thawing cycle is that the distance of each point in the hardened cement from the next artificial air pore does not exceed a defined value. This distance is also referred to as the “Powers spacing factor” [T. C. Powers, The air requirement of frost-resistant concrete, Proceedings of the Highway Research Board 29 (1949) 184-202]. Laboratory tests have shown that exceeding the critical “Power spacing factor” of 500 ⁇ m leads to damage to the concrete in the freezing and thawing cycle. In order to achieve this with a limited air-pore content, the diameter of the artificially introduced air pores must therefore be less than 200-300 ⁇ m [K. Snyder, K. Natesaiyer & K. Hover, The stereological and statistical properties of entrained air voids in concrete: A mathematical basis for air void systems characterization, Materials Science of Concrete VI (2001) 129-214].
• an artificial air-pore system depends critically on the composition and the conformity of the aggregates, the type and amount of the cement, the consistency of the concrete, the mixer used, the mixing time, and the temperature, but also on the nature and amount of the agent that forms the air pores, the air entrainer. Although these influencing factors can be controlled if account is taken of appropriate production rules, there may nevertheless be a multiplicity of unwanted adverse effects, resulting ultimately in the concrete's air content being above or below the desired level and hence adversely affecting the strength or the frost resistance of the concrete.
• One type for example sodium oleate, the sodium salt of abietic acid or Vinsol resin, an extract from pine roots—reacts with the calcium hydroxide of the pore solution in the cement paste and is precipitated as insoluble calcium salt.
• These hydrophobic salts reduce the surface tension of the water and collect at the interface between cement particle, air and water. They stabilize the microbubbles and are therefore encountered at the surfaces of these air pores in the concrete as it hardens.
• the other type for example sodium lauryl sulfate (SDS) or sodium dodecylphenylsulfonate—reacts with calcium hydroxide to form calcium salts which, in contrast, are soluble, but which exhibit an abnormal solution behavior.
• the amount of fine substances in the concrete e.g. cement with different alkali content, additions such as flyash, silica dust or color additions
• additions such as flyash, silica dust or color additions
• air entrainment There may also be interactions with flow improvers that have a defoaming action, and hence expel air pores, but may also introduce them in an uncontrolled manner.
• a relatively new possibility for improving the frost resistance and cyclical freeze/thaw durability is to achieve the air content by the admixing or solid metering of polymeric microparticles (hollow microspheres) [H. Sommer, A new method of making concrete resistant to frost and de-icing salts, Betontechnik & Fertigteiltechnik 9 (1978) 476-84]. Since the microparticles generally have particle sizes of less than 100 ⁇ m, they can also be distributed more finely and uniformly in the concrete microstructure than can artificially introduced air pores. Consequently, even small amounts are sufficient for sufficient resistance of the concrete to the freezing and thawing cycle.
• microparticles of this kind for improving the frost resistance and cyclical freeze/thaw durability of concrete is already known from the prior art [cf. DE 2229094 A1, U.S. Pat. No. 4,057,526 B1, U.S. Pat. No. 4,082,562 B1, DE 3026719 A1].
• the microparticles described therein are notable in particular for the fact that they possess a void smaller than 200 ⁇ m (in diameter) and that this hollow core consists of air (or a gaseous substance). This likewise includes porous microparticles from the 100 ⁇ m scale, which may possess a multiple of relatively small voids and/or pores.
• the object on which the present invention is based was to provide a means of improving the frost resistance and cyclical freeze/thaw durability for hydraulically setting building material mixtures that develops its full activity even at relatively low levels of addition, and which, moreover, can be prepared easily and inexpensively.
• a further object was not, or not substantially, to impair the mechanical strength of the building material mixture as a result of said means.
• microparticles of single-stage or multistage synthesis are also suitable for improvements to the frost resistance and/or cyclical freeze/thaw durability for hydraulically setting building material mixtures.
• microparticles of single-stage synthesis are meant a particle (without a shell) which is synthesized homogeneously in the composition. This is all the more surprising since these polymeric microparticles do not entrain any air into the construction mixture.
• the polymeric microparticles of the invention are in homogeneous distribution in the construction mixture.
• a cavity between microparticle and cured construction mixture which possibly becomes further enlarged as a result of the contraction of the construction mixture on curing, serves as an expansion site for freezing water.
• the polymeric microparticles comprise at least one monoethylenically unsaturated monomer.
• the microparticles may be single-stage or multistage, and the comonomer composition of the individual stages may be different.
• Preferably included are, among others, nitriles of (meth)acrylic acid, and other nitrogen-containing methacrylates, such as methacryloylamidoacetonitrile, 2-methacryloyloxyethylmethylcyanamide, cyanomethyl methacrylate; carbonyl-containing methacrylates, such as oxazolidinylethyl methacrylate, N-(methacryloyloxy)formamide, acetonyl methacrylate, N-methacryloyl-morpholine, N-methacryloyl-2-pyrrolidonone; glycol dimethacrylates, such as 1,4-butanediol methacrylate, 2-butoxyethyl methacrylate, 2-eth
• styrene substituted styrenes with an alkyl substituent in the side chain, such as *methylstyrene and *ethylstyrene, for example, substituted styrenes with an alkyl substituent on the ring, such as vinyl toluene and p-methylstyrene;
• heterocyclic vinyl compounds such as 2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine, 9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinyl-pyrrolidone, 2-vinylpyrrolidone, N-vinylpyrrolidine, 3-vinylpyrrolidine, N-vinyl-caprolactam, N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene, vinylthiolane, vinylthiazoles and hydrogenated vinylthiazoles, vinyloxazoles and hydrogenated vinyloxazoles;
• maleic acid derivatives such as diesters of maleic acid, the alcohol residues having 1 to 9 carbon atoms, maleic anhydride, methylmaleic anhydride, maleimide, and methylmaleimide;
• fumaric acid derivatives such as diesters of fumaric acid, the alcohol residues having 1 to 9 carbon atoms;
• ⁇ -olefins such as ethene, propene, n-butene, isobutene, n-pentene, isopentene, n-hexene, isohexene; cyclohexene.
• free-radically polymerizable monomers having a molar mass of greater than 200 g/mol which carry a hydrophilic radical.
• monomers which carry a polyethylene oxide block having two or more units of ethylene oxide are particularly preferred.
• Preference is given to using monomers from the group of (meth)acrylic esters of methoxypoiyethyiene glycol CH 3 O(CH 2 CH 2 O) n H, (with n 2), (meth)acrylic esters of an ethoxylated C16-C18 fatty alcohol mixture (with 2 or more ethylene oxide units), methacrylic esters of 5-tert-octylphenoxypolyethoxyethanol (with 2 or more ethylene oxide units), nonylphenoxypolyethoxyethanol (with 2 or more ethylene oxide units) or mixtures thereof.
• monoethylenically unsaturated monomers containing an acid group there may be one or more monoethylenically unsaturated monomers containing an acid group present.
• acrylic acid methacrylic acid, ethacrylic acid, a-chloroacrylic acid, a-cyanoacrylic acid, p-methylacrylic acid (crotonic acid), a-phenylacrylic acid, p-acryloyloxypropionic acid, sorbic acid, a-chlorosorbic acid, 2′-methylisocrotonic acid, cinnamic acid, p-chlorocinnamic acid, p-stearylic acid, itaconic acid, citraconic acid, mesacronic acid, glutaconic acid, aconitic acid, maleic acid, fumaric acid, tricarboxyethylene, and maleic anhydride, hydroxyl-or amino-containing esters of the above acids, preferably of acrylic or methacrylic acid, such as 2-hydroxye
• this polymer may also be based on further comonomers other than the monoethylenically unsaturated monomer containing an acid group.
• Preferred comonomers are ethylenically unsaturated sulfonic acid monomers, ethylenically unsaturated phosphonic acid monomers, and acrylamides, preferably.
• Ethylenically unsaturated sulfonic acid monomers are preferably aliphatic or aromatic vinylsulfonic acids or acrylic or methacrylic sulfonic acids.
• Preferred aliphatic or aromatic vinylsulfonic acids are vinylsulfonic acid, allylsulfonic acid, 4-vinylbenzylsulfonic acid, vinyltoluenesulfonic acid, and styrenesulfonic acid.
• Preferred acryloyl-and methacryloylsulfonic acids are sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-hydroxy-3-methacryloyloxypropylsulfonic acid, and 2-acrylamido-2-methyl-propanesulfonic acid.
• Ethylenically unsaturated phosphonic acid monomers such as vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamidoalkylphosphonic acids, acrylamidoalkyldiphosphonic acids. Phosphonomethylated vinylamines, (meth)acryloylphosphonic acid derivatives.
• Possible acrylamides are alkyl-substituted acrylamides or aminoalkyl-substituted derivatives of acrylamide or of methacrylamide, such as N-vinyl-amides, N-vinylformamides, N-vinylacetamides, N-vinyl-N-methylacetamides, N-vinyl-N-methylformamides, N-methylol(meth)acrylamide, vinylpyrrolidone, N,N-dimethylpropylacrylamide, dimethylacrylamide or diethylacrylamide, and the corresponding methacrylamide derivatives, and also acrylamide and methacrylamide, preference being given to acrylamide.
• N-vinyl-amides such as N-vinyl-amides, N-vinylformamides, N-vinylacetamides, N-vinyl-N-methylacetamides, N-vinyl-N-methylformamides, N-methylol(meth)acrylamide, vinylpyrrol
• the chemical crosslinking can be achieved by crosslinkers generally known to the skilled worker.
• the crosslinkers may be present in any state.
• Inventively preferred crosslinkers are polyacrylic or polymethacrylic esters, which are obtained, for example, through the reaction of a polyol or ethoxylated polyol such as ethylene glycol, propylene glycol, trimethylolpropane, 1,6-hexanediol-glycerol, pentaerythritol, polyethylene glycol or polypropylene glycol with acrylic acid or methacrylic acid.
• Use may also be made of polyols, amino alcohols and also their mono(meth)acrylic esters, and monoallyl ethers.
• acrylic esters of monoallyl compounds of the polyols and amino alcohols are also also acrylic esters of monoallyl compounds of the polyols and amino alcohols.
• Another group of crosslinkers is obtained through the reaction of polyalkylenepolyamines such as diethylenetriamine and triethylenetetra-aminemethacrylic acid or methacrylic acid.
• Suitable crosslinkers include 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, ethylene glycol dimethacrylate, 1,6-hexanedioi diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, dipentaerythrito
• the polymeric formations of the invention can be prepared preferably by emulsion polymerization and preferably have an average particle size of 10 to 5000 nm; an average particle size of 150 to 2000 nm is particularly preferred. Most preferable are average particle sizes of 200 to 1000 nm.
• the average particle size is determined, for example, by counting a statistically significant amount of particles by means of transmission electron micrographs.
• initiators for the preparation of the polymeric formations of the invention it is possible to employ all of the initiators and regulators that are customary for emulsion polymerization.
• examples of initiators are inorganic peroxides, organic peroxides or H 2 O 2 , and also mixtures thereof with, if appropriate, one or more reducing agents.
• the water-filled polymeric microparticles are used in accordance with the invention preferably in the form of an aqueous dispersion
• the microparticles are for example coagulated—by methods known to the skilled worker—and isolated from the aqueous dispersion by means of standard methods (e.g. filtration, centrifuging, sedimentation and decanting). The material obtained can be washed and is subsequently dried.
• the polymeric formations are added to the building material mixture in a preferred amount of 0.01% to 5% by volume, in particular 0.1% to 0.5% by volume.
• the building material mixture in the form for example of concrete or mortar, may in this case include the customary hydraulically setting binders, such as cement, lime, gypsum or anhydrite, for example.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37872328

Family Applications (1)

Country Status (4)

Cited By (8)

Families Citing this family (1)

Citations (16)

Family Cites Families (8)

• 2006
  • 2006-03-01 DE DE102006009840A patent/DE102006009840A1/de not_active Withdrawn
  • 2006-03-24 US US11/388,046 patent/US20070204544A1/en not_active Abandoned
  • 2006-05-10 CN CN200610081746.5A patent/CN101028972A/zh active Pending
• 2007
  • 2007-01-30 WO PCT/EP2007/050908 patent/WO2007099009A1/de active Application Filing

Patent Citations (16)

Also Published As

Similar Documents

Legal Events