Silicone composition

Abstract

When the composition of the present disclosure comprising a specific polyether-modified polysiloxane and a silicone hydrophobizing agent is used as an admixture for the overall hydrophobization of a cementitious material, excellent improvements in the water repellency of a hardened cementitious material can be obtained without significant loss of strength, in particular compressive strength, and without significant loss of water repellency. However, when these conventional silicone hydrophobing agents are used, the situation is not the same.

Description

Technical Field

[0001] This invention relates to waterproof materials, and more particularly to the use of organosilicon compositions for the overall hydrophobication of cement-based materials. Background Technology

[0002] Inorganic building materials such as concrete and mortar have numerous micropores and capillaries, making them susceptible to moisture and water penetration, which can lead to structural damage such as steel corrosion, freeze-thaw damage, and alkali-aggregate reactions, severely impacting their service life. Therefore, it is necessary to provide waterproof protection for building surfaces. Organosilicon compounds, due to their excellent impregnation effects and their waterproof, stain-resistant, environmentally friendly, and physiologically acceptable properties, have long been used in building protection.

[0003] Organosilicon compounds have long been used in building protection due to their excellent impregnation effects, waterproofing, stain resistance, environmental friendliness, and physiological acceptability.

[0004] Conventional impregnating agents contain alkoxysilanes with hydrophobic alkyl groups, among which alkyl groups having 8 carbon atoms are widely used, particularly n-octyl or 1,4,4-trimethylpentyl. Typical examples of such hydrophobic silanes are n-octyltriethoxysilane and 1,4,4-trimethylpentyltriethoxysilane.

[0005] Most commercially available compositions for hydrophobicating building materials contain not only the aforementioned silanes, but also other organosilicon compounds, particularly methylsiloxanes, linear polydimethylsiloxanes, or linear polydimethylsiloxanes modified with, for example, amino groups. The corresponding mixtures can be applied in pure substance form, as a solution in an organic solvent, or as an aqueous emulsion.

[0006] In principle, there are two application methods. The first involves using a coating formulation to subsequently hydrophobize existing structures such as concrete bridges, building facades, or roof tiles. Here, at least in the case of porous building materials, the applied coating can penetrate the substrate, thus providing at least some degree of protection. Compared to paint or varnish applied only to the surface, minor surface damage does not necessarily lead to a loss of hydrophobic protection. However, for materials that are only surface-impregnated, larger damage or drilling, cutting, sawing, or breaking edges can result in a loss of protection in the relevant locations.

[0007] While subsequent surface hydrophobication is often the only practical impregnation method for existing buildings, hydrophobic agents can be added before the setting process when producing components based on hydraulic adhesives (e.g., concrete or fiber cement). This integral hydrophobication, also known as bulk hydrophobication, has the advantage of providing waterproof protection to the entire volume of the component, not just its surface. Therefore, the protection is not lost if the component is damaged, intentionally cut, or has holes drilled in it. Additionally, integral hydrophobication eliminates the additional work steps of subsequent coating and curing of the component.

[0008] CN112939512A discloses a dry powder waterproofing agent for use before cement curing to achieve overall hydrophobicity of cement-based materials, which adds polyether trisiloxane to improve the dispersibility of stearate. However, its hydrophobic effect is not as ideal as that of silane waterproofing agents.

[0009] CN1106363C discloses a method for producing monolithic waterproof concrete, wherein a hydrolyzable water emulsion containing an organosilicon compound is added before the curing of a fresh concrete mixture prepared from water, inorganic and optionally organic components. The emulsion contains at least one alkoxysilane and optionally an organosilicon compound as a surfactant.

[0010] While these silicone agents exhibit excellent overall hydrophobicity, the higher silicone content in concrete leads to a lower strength reduction due to the delayed hydration process. To balance concrete strength, it is necessary to reduce the amount of silicone agents used in cementitious materials. Furthermore, their waterproofing performance falls short of optimal levels. There is a lack on the market of silicone-based hydrophobic agents that can guarantee the strength of building substrates such as cement mortar while achieving further breakthroughs in waterproofing performance.

[0011] Due to their amphiphilic nature, polyether-modified polysiloxanes are widely used as surfactants, but there is currently no research or application regarding their use as hydrophobic agents. CN1106363C lists polyether-modified silanes as surfactants in silicone waterproof emulsions. CN111620659A discloses a self-leveling cement waterproof mortar comprising organosilicon and polyether-modified polysiloxane. CN114787100A discloses the use of polyether-modified polysiloxanes as grinding clinker in cement preparation, but does not mention their application in waterproofing. CN106116692B discloses a waterproof emulsion comprising octyltriethoxysilane and polyether-modified polysiloxane, wherein the polyether-modified polysiloxane is used as a co-emulsifier. Summary of the Invention

[0012] The term "cement-based material" refers to a material that solidifies and continues to harden and acquire strength through a hydration process. Known major hydraulic materials include Portland cement, aluminate cement, sulfoaluminate cement, fluoroaluminate cement, and ferroaluminate cement. In one embodiment of this document, cement constitutes at least 70% by weight of the total weight of the cement-based material, for example, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even 100% by weight.

[0013] Cement-based materials include dry mixtures. Dry mixtures (i.e., dry mortar) may contain one or more aggregates, polymers, and admixtures in addition to cement. Admixtures include, but are not limited to, starch ethers, waterproofing agents, anti-setting agents, retarders, superplasticizers, and defoamers.

[0014] Cement-based materials comprise flowable mixtures. Flowable mixtures can be exemplified as paste-like materials obtained by mixing cement or a mixture of cement and other materials with water, including, but not limited to, neat paste, mortar, grout, and concrete. Neat paste is typically a mixture containing cement, admixtures, and water. Mortar is typically a mixture containing cement, sand, admixtures, and water. Grout is typically a mixture containing cement, sand, polymer, admixtures, and water. Concrete is typically a mixture containing cement, sand, aggregate, admixtures, and water. The amount of polymer added is typically based on a total cement weight greater than 1% by weight. The amount of admixture added is typically based on a total cement weight less than 3% by weight.

[0015] "Silica ash" is a fine-grained material containing at least 85% by weight of amorphous silica, and is a byproduct of the production of ferrosilicon or industrial silicon (refer to GB / T27690-2011 standard).

[0016] "Silicone hydrophobic agent" refers to any material with silicone-based components as the main component, used to minimize water absorption and ensure that cleaned surfaces are waterproof.

[0017] "Integral hydrophobicity" refers to mixing a waterproofing agent into cement-based materials before the cement hardens, allowing the waterproofing agent to distribute throughout the cement-based materials to achieve an overall waterproofing effect. It is also known as internal waterproofing or bulk hydrophobicity, which is different from impregnation or coating. Waterproofing, waterproofing, and hydrophobicity have the same meaning in this disclosure.

[0018] "Strength loss" refers to the reduction in strength of the hardened cement-based material compared to a blank sample without a hydrophobic agent. Strength loss = blank sample strength - example sample strength. Reducing strength loss can improve strength retention.

[0019] "Reduced water absorption rate" refers to the decrease in water absorption rate of the hardened cement-based material compared to a blank sample without a hydrophobic agent. Reduced water absorption rate = Water absorption rate of blank sample - Water absorption rate of sample. A greater reduction in water absorption rate indicates better waterproofing performance.

[0020] In this document, "hardened cementitious material" refers to a cementitious material that has been transformed into a solid or nearly solid state through a hardening process. "Hardening" in this document essentially corresponds to the hydration (or solidification) of cement or a mixture containing cement. For the purposes of this disclosure, a hardened cementitious material is not necessarily fully hardened; it can be a material that has been partially or fully hydrated to achieve a certain mechanical strength. A fully hardened cementitious material is one whose hydration is 100% complete.

[0021] The inventors discovered that the polyether-modified polysiloxane and silicone hydrophobic agent disclosed herein have a synergistic effect on the overall hydrophobicity of cement-based materials, which can significantly improve waterproofing, while the silicone hydrophobic agent has a negligible increase in the strength loss of hardened cement-based materials.

[0022] When the compositions of this disclosure containing a specific polyether-modified polysiloxane and a silicone hydrophobic agent are used as admixtures for the overall hydrophobicity of cementitious materials, an excellent improvement in the waterproofness of the hardened cementitious materials can be obtained without significant loss of strength (especially compressive strength), which is not the case when using these conventional silicone hydrophobic agents.

[0023] A first aspect of this disclosure provides a composition comprising component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I; (I) Each R independently represents a monovalent hydrocarbon group having 1 to 30 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms, more preferably a monovalent alkyl group having 1 to 6 carbon atoms, such as methyl or ethyl; R' independently represents R or ; =R 3 -[(C2H4O) x (C3H6O) y ]R 4 ; R 3 =-(CH2) p O-, p is selected from 2-10; preferably 2, 3, 4, 5, 6, more preferably 3 or 4; R 4 Selected from hydrogen, alkyl, aralkyl, aryl or RC(O)-, preferably hydrogen, methyl or acetyl, more preferably hydrogen and methyl; x is selected from 1-60, preferably 1-40, and more preferably 1-20; y is selected from 0-60, preferably 0-40, and more preferably 0-20; The value of x plus y is selected from 2-60, preferably 3-40, and more preferably 10-30; n is selected from 0-20, preferably 0-15, and more preferably 0-10; m is selected from 1-20, preferably 5-20, and more preferably 5-15; The value of n plus m is selected from 3-40, preferably 5-30, and more preferably 10-20; The condition is that when n = 0, at least one R' is selected from... .

[0024] The aforementioned component (1) is a silicone hydrophobic agent, comprising a silane of formula II; and / or a hydrolysis product of a silane of formula II; and / or an oligomer of a silane of formula II.

[0025] R 1 R 2 i -Si-(OR 2 ) 3-i (II) Among them, R 1 It is a monovalent, optionally substituted SiC bonded hydrocarbon group with 1-16 carbon atoms, which can be interrupted by heteroatoms and / or carbonyl groups; R 1 Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and tert-pentyl; hexyl, such as n-hexyl; octyl, such as n-octyl and isooctyl, such as 2,2,4-trimethylpentyl; nonyl, such as n-nonyl; decyl, such as n-decyl; dodecyl, such as n-dodecyl; and cycloalkyl, such as cyclopentyl, cyclohexyl, 4-ethylcyclohexyl, cycloheptyl, norbornyl, and methylcyclohexyl.

[0026] R 1 Examples are alkenyl groups, such as vinyl, allyl, n-5-hexenyl, 4-vinylcyclohexyl, and 3-norbornenyl; R 1 Examples are aryl, such as phenyl, biphenyl, naphthyl, anthracene, and phenanthrene; alkylaryl, such as ortho, meta, and p-tolyl, xylyl, and ethylphenyl; and aralkyl, such as benzyl, α-phenylethyl, and β-phenylethyl.

[0027] R 1 Examples are halogen-substituted alkyl groups, i.e., alkyl groups substituted with fluorine, chlorine, bromine, and iodine atoms, such as 3,3,3-trifluoropropyl, 2,2,2,2',2',2'-hexafluoroisopropyl, and heptafluoroisopropyl. R 1 It is a halogenated aryl group, such as o-chlorophenyl, m-chlorophenyl and p-chlorophenyl.

[0028] R 1 Preferably, a hydrocarbon group has 3-16 carbon atoms; more preferably, an alkyl group has 3-8 carbon atoms, such as octyl or butyl.

[0029] R 2Each time it appears, it is independently a monovalent, optionally substituted SiC-bonded hydrocarbon group with 1 to 8 carbon atoms, which may be interrupted by heteroatoms and / or carbonyl groups.

[0030] Preferably, R 2 It is an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl; hexyl, such as n-hexyl; octyl, such as n-octyl and isooctyl, such as 2,2,4-trimethylpentyl; more preferably methyl, ethyl, n-propyl and isopropyl.

[0031] OR 2 Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, and tert-butoxy; pentoxy, such as n-pentoxy; or hexoxy, such as n-hexoxy. Ethoxy and methoxy are particularly preferred. Alkoxy groups may be substituted with halogen atoms, but this is not preferred.

[0032] i is selected from 0 to 3, preferably 0 or 1, and more preferably 0.

[0033] The aforementioned hydrolysis products typically pass through some ORs in formula II silanes. 3 The group is formed by the reaction of the radical with water or water vapor, resulting in a silicon-bonded OH group.

[0034] The aforementioned oligomers are typically formed by the elimination of some silicon-bonded OH groups in the hydrolysis products of formula II silanes, and may also contain OH and OR. 3 Group.

[0035] Specifically, the aforementioned component (1) silicone hydrophobic agent can be any common silicone waterproofing agent on the market, including silane, silane hydrolysis products, silane oligomers, polysiloxanes or mixtures thereof.

[0036] In one embodiment of this document, component (1) the silicone hydrophobic agent is an alkoxysilane, comprising or selected from the group consisting of: butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, octylmethyldimethoxysilane, octylmethyldiethoxysilane, isooctylmethyldimethoxysilane, isooctylmethyldiethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, propyltriisopropoxysilane, propyltriisobutoxysilane, hexyltriisopropoxysilane, hexyltriisopropoxysilane, n-octyltriisopropoxysilane, n-octyltriisopropoxysilane, n-octyltriisopropoxysilane, n-octyltriisopropoxysilane, n-octyl The silanes include methyl diisopropoxysilane, n-octyltriisopropoxysilane, n-octyltriisopropoxysilane, n-octylmethyl diisopropoxysilane, n-octylmethyl diisopropoxysilane, n-octyltriisopropoxysilane, n-octyltriisobutoxysilane, n-octyltriisobutoxysilane, n-octylmethyl diisobutoxysilane, n-octylmethyl diisobutoxysilane, n-decyltriisopropoxysilane, n-decylmethyl diisopropoxysilane, n-decyltriisobutoxysilane, n-decylmethyl diisobutoxysilane, dodecyltriisopropoxysilane, dodecylmethyl diisopropoxysilane, dodecyltriisobutoxysilane, dodecylmethyl diisobutoxysilane, hexadecyltriisopropoxysilane, hexadecylmethyl diisopropoxysilane, hexadecyltriisobutoxysilane, and hexadecylmethyl diisobutoxysilane. In this embodiment, the alkoxysilane may also include partially hydrolyzed products or oligomers of the aforementioned silanes.

[0037] Preferably, the alkoxysilane is selected from the group consisting of: butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, octylmethyldimethoxysilane, octylmethyldiethoxysilane, isooctylmethyldimethoxysilane, isooctylmethyldiethoxysilane, n-octyltriisopropoxysilane, isooctyltriisopropoxysilane, n-octylmethyldiisopropoxysilane, isooctylmethyldiisopropoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, and their partial hydrolysis products or oligomers.

[0038] More preferably, the alkoxysilane is an oligomer selected from the group consisting of: butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, n-octyltriisopropoxysilane, isooctyltriisopropoxysilane, and their partial hydrolysis products or oligomers. Further preferably, it includes silane oligomers, such as oligomers selected from the group consisting of: butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isooctyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, and isooctyltriethoxysilane.

[0039] Preferably, the viscosity of the aforementioned silane oligomer at 25°C is 3-1000 mm. 2 / s, more preferably a viscosity of 3-500 mm at 25°C. 2 / s, and more preferably a viscosity of 3-300 mm at 25°C. 2 / s.

[0040] The aforementioned component (2) of formula I is a polyether-modified polysiloxane. (I) Each R independently represents a monovalent hydrocarbon group having 1 to 30 carbon atoms; Examples of R are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and tert-pentyl; hexyl, such as n-hexyl; octyl, such as n-octyl and isooctyl, such as 2,2,4-trimethylpentyl; nonyl, such as n-nonyl; decyl, such as n-decyl and dodecyl, such as n-dodecyl; cycloalkyl, such as cyclopentyl, cyclohexyl, 4-ethylcyclohexyl and cycloheptyl, norbornyl and methylcyclohexyl; aryl, such as phenyl, biphenyl, naphthyl, anthraceneyl, and phenanthryl; alkylaryl, such as o-, m-, and p-tolyl, xylyl, and ethylphenyl; aralkyl, such as benzyl, α-phenethyl, and β-phenethyl.

[0041] Examples of R are halogen-substituted alkyl groups, i.e., alkyl groups substituted with fluorine, chlorine, bromine, and iodine atoms, such as 3,3,3-trifluoropropyl, 2,2,2,2',2',2'-hexafluoroisopropyl, and heptafluoroisopropyl. Examples of R are halogenated aryl groups, such as o-chlorophenyl, m-chlorophenyl, and p-chlorophenyl.

[0042] Preferably, R represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, more preferably R represents a monovalent alkyl group having 1 to 6 carbon atoms, such as methyl or ethyl.

[0043] R' is independently selected from R or .

[0044] =R 3 -[(C2H4O) x (C3H6O) y ]R 4 ; R 3 =-(CH2) p O-, p is selected from 2-10; preferably 2, 3, 4, 5, 6, more preferably 3 or 4; R 4 Selected from hydrogen, alkyl, aralkyl, aryl, or RC(O)-; R 4 Examples of such compounds include hydrogen, methyl, ethyl, n-propyl, isopropyl, butyl, hexyl, decyl, dodecyl, 2-phenylethyl, phenyl, and acetyl, with hydrogen, methyl, and acetyl being preferred, and hydrogen and methyl being more preferred.

[0045] x is selected from 1-60, preferably 1-40, more preferably 1-20, for example 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17; y is selected from 0-60, preferably 0-40, more preferably 0-20, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; y is selected from 0-10, preferably 0-5, more preferably 0, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; The value of x plus y is selected from 2 to 60, preferably 3 to 40, more preferably 10 to 30, for example 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26; The value of y / x is selected from 0-3, preferably 0-1, for example 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and more preferably 0; n is selected from 0-20, preferably 0-15, more preferably 0-10, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; m is selected from 1-20, preferably 5-20, more preferably 5-15, for example 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15; The value of n plus m is selected from 3 to 40, preferably 5 to 20, more preferably 10 to 20, for example 11, 12, 13, 14, 15, 16, 17, 18, 19, 20; The condition is that when n = 0, at least one R' is selected from... .

[0046] Preferably, the polyether-modified polysiloxane of the aforementioned component (2) is selected from polyether-modified polysiloxanes of formula III or IV; (III) (IV) Among them, R, , n and m are as defined in Equation I, and n is greater than 0.

[0047] The polyether-modified polysiloxane of the aforementioned component (2) formula I has a viscosity of 50-700 mm at 25°C. 2 / s, more preferably a viscosity of 100-500 mm at 25°C. 2 / s, further preferably a viscosity of 150-400 mm at 25°C. 2 / s.

[0048] In this disclosure, a composition comprising component (1) a silicone hydrophobic agent and component (2) of formula I, a polyether-modified polysiloxane, should be understood as having component (1) a silicone hydrophobic agent and component (2) of formula I, a polyether-modified polysiloxane, as the main components of the composition. The composition may also contain components for dissolving or stabilizing their dispersion, or components that serve as their dispersion medium, but these components are not considered main components. In this context, "main component" can also be understood as component (1) a silicone hydrophobic agent and component (2) of formula I, a polyether-modified polysiloxane, comprising at least 20% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, for example, 55%, 60%, 65%, 70%, 75%, or 80% of the total weight of the composition.

[0049] The weight ratio of component (2) to component (1) is selected from 0.01-80, such as 0.02-80, 0.02-70, 0.02-60, 0.02-50, 0.02-40, 0.02-30, preferably 0.02-20, such as 0.03-10, 0.03-5, 0.03-3, 0.03-2, more preferably 0.03-1.5, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4.

[0050] The composition comprises 20-80% by weight of component (1) and 20-80% by weight of component (2), preferably 30-70% by weight of component (1) and 30-70% by weight of component (2), more preferably 40-60% by weight of component (1) and 40-60% by weight of component (2), based on 100% by weight of the composition.

[0051] A second aspect of this disclosure provides a waterproof emulsion comprising the aforementioned composition, water, and an emulsifier.

[0052] The composition can be a self-dispersing system comprising the aforementioned components (1) and (2), particularly an emulsion comprising them. As used herein, "self-dispersing system" refers to a dispersion or suspension of components (1) and (2) in an emulsifier, water, or an organic solvent (e.g., an alkanol such as ethanol or glycerol) or a non-solvent liquid carrier. The term "emulsion" includes simple direct emulsions (oil-in-water), reverse emulsions (water-in-oil), or multiple emulsions (e.g., oil-in-water, water-in-water-in-oil).

[0053] In one embodiment of this disclosure, components (1) and (2) are used as admixtures for the overall hydrophobicity of cementitious materials in the form of an emulsion. The emulsion comprises the aforementioned components (1) and (2), an emulsifier (3), and water (4). The content of components (1) and (2) in the emulsion is not particularly limited, but is suitably 20% to 60% by weight, preferably 30% to 55% by weight, and more preferably 35% to 50% by weight.

[0054] The emulsifier (3) can be any emulsifier used to date for the production of silane dispersions, such as anionic, cationic, nonionic, and amphoteric surfactants or mixtures thereof, with nonionic emulsifiers being preferred. Examples of suitable nonionic emulsifiers include fatty alcohol polyoxyethylene ethers, fatty acid polyoxyethylene esters, ethylene oxide-propylene oxide copolymers, sorbitol fatty acid esters, ethoxylated sorbitol fatty acid esters, pentaerythritol fatty acid esters, glycerol fatty acid esters, and mixtures thereof. Fatty alcohol polyoxyethylene ethers, fatty acid polyoxyethylene esters, sorbitol fatty acid esters, ethoxylated sorbitol fatty acid esters, and mixtures thereof having 10 to 20 carbon atoms are preferred. The nonionic emulsifier preferably contains at least one nonionic emulsifier with an HLB value equal to or greater than 12.

[0055] Emulsifiers are preferably used in minimal amounts to stabilize the emulsion, for example, 0.01-5% by weight, or even 0.1-3% by weight, preferably 0.1-2% by weight, more preferably 0.1-1% by weight, based on the total weight of the emulsion, as it may reduce the strength of the hardened cementitious material.

[0056] The content of water (4) in the emulsion is not particularly limited, but is suitably 35% to 75% by weight, preferably 40% to 65% by weight, and more preferably 45% to 60% by weight.

[0057] The emulsion may further contain appropriate amounts of other optional components (5), such as pH adjusters, antifreeze agents and preservatives, provided that they do not impair the implementation of the invention.

[0058] The emulsion is preferably free of water-immiscible solvents, nanofillers, other hydrophobic components, and other silicon compounds. "Water-immiscible solvents" refer to solvents with a solubility in water of no more than 1 g / L at 20°C and 101 kPa, such as benzene, toluene, xylene, hexane, and cyclohexane. Examples of nanofillers include, but are not limited to, nano-alumina, nano-aluminum hydroxide, nano-calcium oxide, and nano-zinc oxide. Other hydrophobic components include, but are not limited to, stearic acid, calcium stearate, zinc stearate, aluminum stearate, dodecyl alcohol, cetyl alcohol, octyl alcohol, butyltrimethoxysilane, butyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, isooctyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, n-decyltrimethoxysilane, and n-decyltriethoxysilane. Other silicon compounds refer to compounds containing silicon atoms other than alkoxysilanes or alkoxysiloxanes (a), polysiloxanes (d), and aminosilanes (e), such as bis-(γ-trimethoxysilylpropyl)amine, bis-(γ-triethoxysilylpropyl)amine, and aminoalkyl-free polysiloxanes. In this disclosure, "free of" means that the component is present in the emulsion at a concentration of less than 1% by weight, or even less than 0.5% by weight, 0.1% by weight, or 0.01% by weight of the total emulsion weight.

[0059] Emulsions containing the aforementioned compositions can be prepared by methods known in the art.

[0060] A third aspect of this disclosure provides a waterproof powder comprising the aforementioned composition and a solid carrier.

[0061] In this disclosure, the aforementioned components (1) and (2) can also be adsorbed onto a solid carrier and used as an admixture for the overall hydrophobicity of cement-based materials in powder form. Considering that the aforementioned component (1) silicone hydrophobic agent and component (2) polyether-modified polysiloxane of formula I are not easily adsorbed directly onto cement-containing cementitious materials, it is preferable to first adsorb them onto a solid carrier (6) and then mix them into the cement-based materials. Suitable solid carriers (6) are typically porous materials, including but not limited to silica fume, silica, alumina, activated carbon, talc, zeolite, calcium carbonate, calcium silicate, diatomaceous earth, and clay.

[0062] The aforementioned powder comprises the aforementioned components (1) and (2) and a solid carrier (6). The content of components (1) and (2) in the emulsion is not particularly limited, but is suitably 10% to 50% by weight, preferably 15% to 40% by weight, and more preferably 20% to 30% by weight.

[0063] The content of solid carrier (6) in the powder is not particularly limited, but is suitably 50% to 90% by weight, preferably 60% to 85% by weight, and more preferably 70% to 80% by weight.

[0064] The water content of the aforementioned powder is less than 1% of the total weight of the powder, preferably less than 0.5% or 0.2%, more preferably 0.1% or 0.01%.

[0065] The fourth aspect of this disclosure provides the use of the aforementioned compositions, emulsions, or powders for the overall hydrophobication of cement-based materials, particularly for reducing strength loss.

[0066] In this disclosure, a composition comprising component (1) a silicone hydrophobic agent and component (2) of formula I, a polyether-modified polysiloxane, is incorporated into the cementitious material at a dosage of 0.1% to 3% of the total mass of the cement, preferably 0.1% to 2%, for example 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and especially 0.1% to 1% for overall hydrophobication. If the dosage is too low, the waterproofing of the cementitious material is not ideal. If the dosage is too high, the waterproofing may not be further improved, but may lead to increased costs and a significant loss of strength in the hardened cementitious material. In the context of this disclosure, the active ingredient comprises component (1) a silicone hydrophobic agent and component (2) of formula I, a polyether-modified polysiloxane. Preferably, component (1) silicone hydrophobic agent and component (2) polyether-modified polysiloxane of formula I account for at least 95% by weight, even at least 98% by weight, and at least 99% by weight of the total weight of the active ingredients. When component (1) silicone hydrophobic agent and component (2) polyether-modified polysiloxane of formula I are used as admixtures in emulsion form, the dosage is calculated as a percentage of the mass of component (1) silicone hydrophobic agent and component (2) polyether-modified polysiloxane of formula I relative to the total mass of cement.

[0067] There are no particular limitations on the method of making cement-based materials hydrophobic, as long as the aforementioned composition is fully incorporated into the cement-based material as a waterproofing admixture before setting and hardening. The waterproofing admixture can be added during the preparation or post-treatment of the cement-based material, or during the post-treatment of the raw materials used to prepare the cement-based material. Specifically, the waterproofing admixture can be added during the post-treatment of the cement-based material, for example, by adding it to treated cement; it can also be added during the preparation of dry or flowable mixtures containing cement, specifically, for example, during the preparation of neat paste, mortar, grout, or concrete; furthermore, the waterproofing admixture can also be added during the post-treatment of the raw materials used to prepare the cement-based material (such as aggregates, such as sand, stone, polymers, and admixtures).

[0068] In one embodiment of this document, a composition comprising component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I as a waterproofing admixture is added during the preparation of a flowable mixture, and then the thoroughly mixed flowable mixture is transformed into a solid or nearly solid state through a solidification and hardening process. When the aforementioned composition is used as an admixture in emulsion form, the emulsion can be mixed with water, and then the resulting wet mixture can be added to a dry mixture containing cementitious materials and thoroughly mixed. When the aforementioned composition is used as an admixture in powder form, the powder can be mixed with cementitious materials and other dry materials, and then water can be added and thoroughly mixed.

[0069] The fifth aspect of this disclosure provides a cement-based material comprising the aforementioned composition, or a waterproof emulsion, or a waterproof powder, wherein the dosage of the active ingredient is 0.1-3% by weight of the total cement mass, preferably 0.1-2% by weight, for example 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, preferably 0.1% to 1%, wherein the active ingredient comprises component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I, preferably the active ingredient being composed of component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I.

[0070] The cement-based material disclosed herein has high water resistance. Based on a blank sample without hydrophobic agents (tested according to standard JGJ / T70-2009), the water absorption rate reduction rate after 24 hours is higher than 72%, for example 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, preferably higher than 75%, and more preferably higher than 80%.

[0071] The cement-based material disclosed herein exhibits minimal strength loss, and based on a blank sample without hydrophobic agents (tested according to standard JGJ / T 70-2009), the 28-day compressive strength retention rate is higher than 80%, for example 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, preferably higher than 83%, and more preferably higher than 85%. Detailed Implementation

[0072] Silicone hydrophobic agent 1: Octyltriethoxysilane oligomer (99% purity); viscosity at 25°C is 130-300 mm. 2 / s (measured according to DIN 51562-1); Silicone hydrophobic agent 2: Octyltriethoxysilane (purity 99%); Polyether-modified polysiloxane 1: belongs to the aforementioned formula (I), n=4, m=10; viscosity at 25℃ is 327 mm.2 / s (measured according to DIN 51562-1), as shown in formula a (purity 99%): Formula a Polyether-modified polysiloxane 2: belongs to the aforementioned formula (I), n=0, m=15; viscosity at 25℃ is 200 mm. 2 / s, (measured according to DIN 51562-1), as shown in formula b (purity 99%): (b) Polyether-modified polysiloxane 3: an additive with a molar ratio of n=4.5, m=70 and n=8, m=42 of 2:1, has a viscosity of 800 mmHg at 25°C. 2 / s (measured according to DIN 51562-1); as shown in formula c (purity 99%): (c) Polyether-modified polysiloxane 4: belongs to the aforementioned formula (I), but n=1, m=0; viscosity at 25℃ is 10-25 mm. 2 / s (measured according to DIN 51562-1), as shown in formula d (purity 99%): (d) The above-mentioned substances were provided by WACKER Chemie AG.

[0073] All viscosity data in this disclosure were obtained according to DIN 51562-1.

[0074] Oleic acid: Commercially available, 99% pure.

[0075] Cement: The reference cement for concrete admixture testing shall comply with Appendix A of standard GB8076-2008.

[0076] Sand: ISO standard sand, conforming to standard GB / T1761-1999.

[0077] Composition: Prepared by mixing the above-mentioned silicone hydrophobic agent and / or polyether-modified polysiloxane or oleic acid, comprising a self-assembled structure formed by mixing the silicone hydrophobic agent and the polyether-modified polysiloxane, in the form of an oily mixture, emulsion or powder, without limitation.

[0078] The preparation process of waterproof emulsion is as follows: Add 0.5-3g of emulsifier and 0.5-5g of water to the container. Turn on the homogenizer (T25, equipped with a 25F stator and rotor) and start working at 1500 rpm. Add 0-50g of silicone hydrophobic agent to the container in batches at 2000 rpm, homogenizing at 2000 rpm for 3 minutes after each addition. Add 0-50g of polyether-modified polysiloxane to the container in batches at 2000 rpm, homogenizing at 2000 rpm for 3 minutes after each addition. Add 47.5g of water to the container in batches at 2000 rpm, homogenizing at 2000 rpm for 3 minutes after each addition, until the emulsion is uniform and stable.

[0079] The waterproof powder preparation process is as follows: Add 75 grams of silica fume to a container, turn on the mixer at 300 rpm, add 0-25 grams of silicone hydrophobic agent to the container in batches, and mix at 300 rpm for 3 minutes after each addition. Then add 0-25 grams of polyether-modified polysiloxane to the container in batches, and mix at 300 rpm for 3 minutes after each addition. After that, stir thoroughly to obtain a free-flowing powdered waterproofing agent.

[0080] The mortar preparation process is as follows: Referring to the formulation in Table 1-3, add the composition, water, and cement to the mixing vessel and fix the vessel to the mixer. Start the mixer at a low mixing speed (140 rpm) for 30 seconds, then steadily add sand over the next 30 seconds. Switch the mixer to a high mixing speed (285 rpm) and continue mixing for another 30 seconds; then stop the mixer for 90 seconds. During the first 30 seconds, scrape off the mortar adhering to the walls and bottom of the vessel with a rubber scraper and place it in the center of the vessel. Continue mixing at a high speed (285 rpm) for 60 seconds (according to ISO EN 196-1). Once the mortar is prepared, compact it into a mold to obtain a cube of 70.7 × 70.7 × 70.7 mm.

[0081] The mortar in the mold was kept at 90% relative humidity (RH) and (20±2)℃ for 24 hours. After that, the sample was demolded and placed back in the curing room at 90% RH and (20±2)℃ for another 27 days.

[0082] Water absorption and compressive strength were measured after 28 days (according to JGJ / T 70-2009). Table 1-3 shows the values ​​of 24-hour water absorption (%) and 28-day compressive strength (MPa).

[0083] The 24-hour water absorption rate (%) refers to the water absorption rate of the above mortar after soaking in water for 24 hours (according to JGJ / T 70-2009).

[0084] The 28-day compressive strength (MPa) refers to the compressive strength of the above-mentioned mortar at 28 days of age (according to JGJ / T 70-2009).

[0085] Table 1 Mortar of Examples and Comparative Examples

[0086] The rate of decrease in water absorption rate relative to the blank control group = (24-hour water absorption rate decrease) / 24-hour water absorption rate of the blank control group = (24-hour water absorption rate of the blank control group - 24-hour water absorption rate of the example) / 24-hour water absorption rate of the blank control group.

[0087] The compressive strength retention rate relative to the blank control group = (compressive strength loss after 28 days) / compressive strength of the blank control group after 28 days = (compressive strength of the blank control group after 28 days - compressive strength of the example after 28 days) / compressive strength of the blank control group after 28 days.

[0088] The results of the blank control group and comparative examples 1-2 in Table 1 show that when only conventional silicone hydrophobic agent 1 is used as the composition, the 24-hour water absorption rate is significantly reduced. However, when the amount of silicone hydrophobic agent 1 is further increased, the 24-hour water absorption rate is further reduced, but this is accompanied by a significant decrease in compressive strength.

[0089] In Comparative Examples 5-6, compositions containing only polyether-modified polysiloxanes reduced the 24-hour water absorption rate to some extent, but fell far short of the waterproofing requirements for practical applications.

[0090] The compositions of Examples 3-4, comprising silicone hydrophobic agent 1 and polyether-modified polysiloxanes 1-2, significantly reduced 24-hour water absorption compared to using conventional silicone hydrophobic agent 1 alone, while maintaining no significant strength loss. These compositions are valuable for the overall hydrophobication of cement-based materials, achieving a 24-hour water absorption reduction of over 72% and a compressive strength retention of over 80% based on blank samples.

[0091] Table 2 Mortar of Examples and Comparative Examples

[0092] The reduction rate of water absorption rate based on Comparative Example 1 (%) = (reduction in water absorption rate over 24 hours) / 24-hour water absorption rate of Comparative Example 1 = (24-hour water absorption rate of Comparative Example 1 – 24-hour water absorption rate of Example 1) / 24-hour water absorption rate of Comparative Example 1.

[0093] The compressive strength retention rate (%) based on Comparative Example 1 = (28-day compressive strength loss) / 28-day compressive strength of Comparative Example 1 = (28-day compressive strength of Comparative Example 1 – 28-day compressive strength of Example 1) / 28-day compressive strength of Comparative Example 1.

[0094] Comparative Examples 7-8 in Table 2 show that adding polyether-modified polysiloxanes 3-4 and silicone hydrophobic agent 1 (which are not within the scope of this application) to the mortar resulted in no significant reduction in water absorption or a more severe decrease in compressive strength compared to using only conventional silicone hydrophobic agent 1 as the mortar composition in Comparative Example 1.

[0095] In Comparative Example 9, the addition of oleic acid to silicone hydrophobic agent 1 resulted in a more significant reduction in water absorption compared to Comparative Example 1. However, the loss of compressive strength was also more severe, with a compressive strength retention rate of only 68%.

[0096] The mortars of Examples 3-4 contain compositions comprising the silicone hydrophobic agent 1 of this application and polyether-modified polysiloxanes 1-2, achieving a 24-hour water absorption reduction rate of over 10% and a compressive strength retention rate of 90% based on Comparative Example 1.

[0097] Table 3 Mortar Examples

[0098] The results of Examples 10-15 in Table 3 show that the polyether-modified polysiloxane of this application can be used together with various silicone hydrophobic agents for the overall hydrophobicity of mortar, showing excellent improvement in waterproofing.

Claims

1. A composition comprising component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I; （I） Each R independently represents a monovalent hydrocarbon group having 1 to 30 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms, more preferably a monovalent alkyl group having 1 to 6 carbon atoms, such as methyl or ethyl; R' independently represents R or ; =R 3 -[(C2H4O) x (C3H6O) y ]R 4 ; R 3 =-(CH2) p O-, p is selected from 2-10; preferably 2, 3, 4, 5, 6, more preferably 3 or 4; R 4 Selected from hydrogen, alkyl, aralkyl, aryl or RC(O)-, preferably hydrogen, methyl or acetyl, more preferably hydrogen and methyl; x is selected from 1-60, preferably 1-40, and more preferably 1-20; y is selected from 0-60, preferably 0-40, and more preferably 0-20; The value of x plus y is selected from 2-60, preferably 3-40, and more preferably 10-30; n is selected from 0-20, preferably 0-15, and more preferably 0-10; m is selected from 1-20, preferably 5-20, and more preferably 5-15; The value of n plus m is selected from 3-40, preferably 5-30, and more preferably 10-20; The condition is that when n = 0, at least one R' is selected from... .

2. The composition of claim 1, wherein, The component (2) is selected from polyether-modified polysiloxanes of formula III or IV; (III) (IV) Among them, R, The definitions of , n, and m are the same as in Equation I, and n is greater than 0.

3. The composition according to claim 1 or 2, wherein, The value of y / x is selected from 0-3, preferably 0-1, and more preferably 0; And / or y is selected from 0-10, preferably 0-5, more preferably 0.

4. The composition according to any one of claims 1-3, wherein, The component (1) silicone hydrophobic agent comprises a silane of formula II; and / or a hydrolysis product of a silane of formula II; and / or an oligomer of a silane of formula II; R 1 R 2 i -Si-(OR 2 ) 3-i (II) Among them, R 1 It is a monovalent, optionally substituted SiC-bonded hydrocarbon group having 1-16 carbon atoms, which may be interrupted by heteroatoms and / or carbonyl groups; preferably a hydrocarbon group having 3-16 carbon atoms; more preferably an alkyl group having 3-8 carbon atoms, such as octyl or butyl; R 2 Each time it appears independently, it is a monovalent, optionally substituted SiC-bonded hydrocarbon group having 1 to 8 carbon atoms, which may be interrupted by heteroatoms and / or carbonyl groups; preferably, it is an alkyl group having 1 to 8 carbon atoms, more preferably, R 2 It is methyl, ethyl, n-propyl, or isopropyl; i is selected from 0 to 3, preferably 0 or 1, and more preferably 0.

5. The composition according to any one of claims 1-4, wherein, The component (1) silicone hydrophobic agent comprises silane oligomers, which are preferably oligomers selected from the group consisting of: butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, and isooctyltriethoxysilane. And / or the viscosity of the aforementioned silane oligomers at 25°C is 3-1000 mm. 2 / s, more preferably a viscosity of 3-500 mm at 25°C. 2 / s, and more preferably a viscosity of 3-300 mm at 25°C. 2 / s.

6. The composition according to any one of claims 1-5, wherein, Based on 100% by weight of the composition, the composition comprises 20-80% by weight of component (1) and 20-80% by weight of component (2), preferably 30-70% by weight of component (1) and 30-70% by weight of component (2), more preferably 40-60% by weight of component (1) and 40-60% by weight of component (2). The weight ratio of component (2) to component (1) is selected from 0.01-80, preferably 0.02-20, and more preferably 0.03-1.5; And / or based on 100% by weight of the composition, component (1) silicone hydrophobic agent and component (2) polyether modified polysiloxane of formula I account for at least 20% by weight of the total weight of the composition, preferably at least 40% by weight, more preferably at least 50% by weight, for example 55%, 60%, 65%, 70%, 75%, 80%.

7. The composition according to any one of claims 1-6, wherein, The viscosity of component (2) at 25°C is 50-700 mm. 2 / s, more preferably a viscosity of 100-500 mm at 25°C. 2 / s, and more preferably, the viscosity at 25°C is 150-400 mm. 2 / s.

8. A waterproof composition comprising 20-60% by weight of the composition according to any one of claims 1-7, 35-75% by weight of water and 0.1-5% by weight of an emulsifier; Preferably, it comprises 30-55% by weight of the composition according to any one of claims 1-7, 40-65% by weight of water, and 0.1-5% by weight of emulsifier; More preferably, it comprises 35-50% by weight of the composition according to any one of claims 1-7, 40-65% by weight of water and 0.1-5% by weight of emulsifier.

9. A waterproof composition comprising 10-50% by weight of the composition according to any one of claims 1-7 and 50-90% by weight of a solid carrier; Preferably, it comprises 15-40% by weight of the composition according to any one of claims 1-7 and 60-85% by weight of a solid carrier; More preferably, it comprises 20-30% by weight of the composition according to any one of claims 1-7 and 70-80% by weight of a solid carrier.

10. Use of the composition according to any one of claims 1-9 for the overall hydrophobication of cement-based materials.

11. Use of the composition according to any one of claims 1-9 for the integral hydrophobication of cement-based materials to reduce strength loss.

12. A waterproof cement-based material comprising the composition according to any one of claims 1-9, wherein the dosage of the active ingredient is 0.1-3 wt%, preferably 0.1-2 wt%, preferably 0.1% to 1% based on the total mass of cement, said active ingredient comprising component (1) a silicone hydrophobic agent and component (2) a polyether-modified polysiloxane of formula I.

13. The waterproof cement-based material according to claim 12, wherein, The components (1) silicone hydrophobic agent and (2) polyether-modified polysiloxane of formula I account for at least 95% by weight of the total weight of the active ingredients, preferably at least 98% by weight, and more preferably at least 99% by weight.

14. The waterproof cement-based material according to claim 12 or 13, based on the test of JGJ / T 70-2009 and a blank sample without waterproof admixture, has a 24-hour water absorption rate reduction rate of more than 72% and a 28-day compressive strength retention rate of more than 80%.

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