JP2000319549A - Permeable water absorption-preventing material- containing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water absorption-preventing composition having good storage stability and capable of simultaneously carrying out formation of water- repelling layer in the interior of a substrate and formation of a film on the surface of substrate without causing lowering of permeability even when applied after long-term storage. SOLUTION: This water absorption-preventing composition comprises (A) an acrylic synthetic resin emulsion in an amount of 100 pts.wt., expressed in terms of solid content, containing a carboxylic acid-containing monomer in an amount of <=2.0% based on total weight of monomer, (B) a silane-based permeable water absorption-preventing material in an amount of 30-400 pts.wt., expressed in terms of solid content and (C) 5-50 pts.wt. organic solvent having >=20 wt.% solubility to water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based permeable water-absorbing material-containing composition used for protecting cement-based materials such as concrete, cement mortar, and cement-based secondary products.

[0002]

2. Description of the Related Art Water-absorbing prevention properties are imparted to cement-based materials such as concrete, cement mortar, and cement-based secondary products which have conventionally been used as building bodies of buildings and civil engineering structures to improve durability. As a method, a method of applying a solvent-based osmotic water-absorbing material containing a silane-based compound as a main component is widely used.

[0003] The permeable water-absorbing material penetrates deeply into a cement-based material such as concrete, cement mortar, and cement-based secondary products to form a water-repellent layer, and water or carbon dioxide gas enters from the outside. By blocking the heat, the strength of the base material is prevented from lowering due to the neutralization, and the effect of suppressing the corrosion of the steel frame or the rebar existing inside the precursor is exhibited. Further, it is possible to prevent the occurrence of efflorescence on the surface layer of the base material due to the migration of the calcium component inside the base material. After applying such a permeable water-absorbing preventive material to a base material, a durability is further improved by applying a solvent-based resin paint having a coating film forming property.

[0004] However, in recent years, in consideration of the surrounding environment and work hygiene, there has been an increasing demand for making such materials water-soluble, and various water-permeable, water-absorbing materials have been proposed. Further, for the purpose of shortening the process, an aqueous composition having both water absorption preventing property and film forming property has been proposed. As such an aqueous composition,
JP-A-05-97542, JP-A-05-2872
34, JP-A-06-256072, and JP-A-10-236889.
Each of such compositions contains an aqueous binder component having film forming properties and a silane component having permeability.

When a composition as described in the above publication is applied to the surface of a cement-based substrate, a coating film is formed on the surface of the substrate, and at the same time, the silane component enters the inside of the substrate.
It is said that durability, aesthetics, corrosion resistance and the like can be simultaneously provided.

[0006] The present inventors have tried to confirm the osmotic effect of the composition described in the above publication.
As a result, some compositions exhibited high permeability when used for a short period of time (within several days) after preparation of the composition. However,
In any of the compositions, a phenomenon was observed in which the storage period was prolonged, the permeability decreased, and the composition expired. After examining the causes of this phenomenon,
It has been found that the reaction of the silane component progresses with time, resulting in a polymerization, resulting in a decrease in permeability.

[0007] Usually, the coating composition is used after being stored for several days to several months after production, and it is extremely difficult to commercialize a composition which loses its effect in such a short period of time.

[0008]

Therefore, the problem to be solved by the present invention is that the storage stability is good and the water repellency inside the base material does not decrease even when coated after long-term storage. An object of the present invention is to obtain a water-absorbing preventive composition that can simultaneously form a layer and form a film on the surface of a substrate.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an acrylic synthetic resin emulsion and a composition containing a silane-based permeable water-absorbing material are contained in the acrylic synthetic resin emulsion. It has been found that carboxylic acids greatly contribute to the reactivity and stability of the silane-based osmotic water-absorbing material. Based on this, it has been found that all of these problems can be solved by making the carboxylic acid-containing monomer of the acrylic synthetic resin emulsion a specific amount, and furthermore, by making the hydrophilic organic solvent contain a specific amount. Completed the invention.

That is, the permeable water-absorbing material-containing composition of the present invention has the following characteristics. 1. (A) 100 parts by weight of an acrylic synthetic resin emulsion in terms of solid content, (B) 30 to 400 parts by weight of a silane-based permeable water-absorbing inhibitor in terms of solid content, and (A) acrylic synthetic resin An osmotic water-absorbing material-containing composition, wherein the emulsion contains a carboxylic acid-containing monomer in an amount of 2.0% or less based on the total weight of the monomer. 2. Further, (C) 5 to 50 parts by weight of an organic solvent having a solubility in water of 20 wt% or more is contained. The composition containing a permeable water-absorbing inhibitor according to item 1.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on its embodiments.

[0012] The permeable water-absorbing material-containing composition of the present invention comprises:
(A) Acrylic synthetic resin emulsion (hereinafter referred to as (A)
Component) and (B) a silane-based osmotic absorption inhibitor (hereinafter, referred to as component (B)).

When the composition containing a permeable water-absorbing material of the present invention is applied to the surface of a cement-based substrate, the component (A) has a role of forming a film on the surface of the substrate, and is waterproof, weather-resistant and durable. It has the effect of improving the properties.

In the composition of the present invention, the weight ratio of the carboxylic acid-containing monomer as the component (A) is 2.0% or less, preferably 1.0% or less, more preferably 1.0% or less, based on the total weight of the monomers. When the content is 0.8% or less, the storage stability is improved, and the permeability does not decrease even when coated after long-term storage. This is because the reactivity of the silane compound contained in the component (B) is suppressed by setting the carboxylic acid of the component (A) to a specific amount or less.

(A) The acrylic synthetic resin emulsion includes an acrylic monomer, a carboxylic acid-containing monomer, and, if necessary, other monomers copolymerizable with these monomers. Those obtained by radical copolymerization can be used.

The acrylic monomer is not particularly restricted but includes, for example, methyl (meth) acrylate (indicating either methyl acrylate or methyl methacrylate; the same applies hereinafter) and ethyl (meth).
Acrylate, n-butyl (meth) acrylate, i-
Alkyl group-containing (meth) acrylic monomers such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate; 2
Hydroxyl-containing (meth) acrylic monomers such as hydroxyethyl (meth) acrylate; amino-containing (meth) acrylic monomers such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate; Amide-containing (meth) acrylic monomers such as meth) acrylamide and ethyl (meth) acrylamide; nitrile-containing (meth) acrylic monomers such as acrylonitrile; epoxy-containing (meth) such as glycidyl (meth) acrylate An acrylic monomer can be exemplified.

Examples of the carboxylic acid-containing monomer include (meth)
Examples thereof include acrylic acid, maleic acid, itaconic acid, crotonic acid, fumaric acid, citraconic acid, maleic anhydride, and fumaric anhydride.

Other monomers copolymerizable with an acrylic monomer or a carboxylic acid-containing monomer include aromatic hydrocarbon-based vinyl monomers such as styrene, methylstyrene, chlorostyrene, and vinyltoluene; Chlorine-containing monomers such as vinyl chloride, vinylidene chloride and chloroprene; hydroxyl-containing alkyl vinyl ethers such as hydroxyethyl vinyl ether and hydroxypropyl vinyl ether; alkylene glycol monoallyl such as ethylene glycol monoallyl ether, propylene glycol monoallyl ether and diethylene glycol monoallyl ether Ether; α-olefins such as ethylene, propylene, and isobutylene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl pivalate; methyl vinyl ether, ethyl Vinyl ethers such as vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; allyl ethers such as ethyl allyl ether and butyl allyl ether; γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- ( Hydrolyzable silyl group-containing vinyl monomers such as (meth) acryloxypropylmethyldimethoxysilane and γ- (meth) acryloxypropylmethyldiethoxysilane; vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, pentafluoroethylene And fluoroolefins such as hexafluoropropylene; trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) a It can be exemplified fluorine-containing (meth) acrylate such relations.

The (B) silane-based permeable water-absorbing material in the composition of the present invention penetrates a cement-based substrate to form a water-repellent layer, and has a water-absorbing property, a neutralizing property, a corrosion-proofing property, and an effluent. It is a component that exerts effects such as the prevention of occurrence of redness.
In the present invention, since the reactivity of the silane compound contained in the component (B) is suppressed, such effects are sufficiently exerted even when coating is performed after long-term storage.

As the component (B), there can be mentioned those obtained by subjecting a hydrolyzable silane compound to an aqueous emulsion with various surfactants.

Examples of the hydrolyzable silane compound include, for example, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, and ethyltrimethoxysilane. Butoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltributoxysilane, butyltrimethoxylan, butyltriethoxysilane, butyltripropoxysilane, butyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane Silane, dimethyldipropoxysilane, dimethyldibutoxysilane, diethyldimethylsilane, diethyldiethoxysilane, diethyldipropoxysilane, Ethyl dibutoxy silane, hexyl trimethoxy silane, hexyl triethoxy silane, hexyl tripropoxy silane, octyl trimethoxy silane, octyl triethoxy silane, octyl tripropoxy silane, decyl trimethoxy silane, dodecyl trimethoxy silane, octadecyl trimethoxy silane, Examples include phenyltrimethoxysilane and vinyltrimethoxysilane. These can be used alone or as a mixture of plural types.

The surfactant for converting the hydrolyzable silane compound into an aqueous emulsion is selected from nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Seed, or 2
More than one species can be used as appropriate. Of these, the use of a nonionic surfactant is preferred because the reactivity of the hydrolyzable silane compound can be suppressed and sufficient storage stability can be ensured. As the nonionic surfactant,
For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl amino ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester and the like can be mentioned.

In the composition of the present invention, the weight ratio of the component (B) is from 30 to 100 parts by weight of the solid content of the component (A).
400 parts by weight (preferably 120 to 200 parts by weight). When the amount of the component (B) is less than 30 parts by weight, the water-repellent layer is not sufficiently formed, and the water absorption preventing property, the neutralizing preventing property, the corrosion preventing property, the eflorescence generating preventing property and the like are deteriorated. 4
When the amount is more than 00 parts by weight, the film-forming property is reduced.

In the composition of the present invention, storage stability can be further enhanced by including (C) an organic solvent having a solubility in water of 20% by weight or more (hereinafter referred to as "component (C)"). This is because when such an organic solvent is contained, the action of suppressing the dissociation of the carboxylic acid contained in the component (A) works, and the reactivity of the silane compound contained in the component (B) is further suppressed. Conceivable.

[0025] Further, by containing the component (C), the effect of increasing the permeability to the cement base material can be enhanced.

As the component (C), for example,
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, triethylene Glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 1-3 butanediol,
Examples thereof include 1-5 pentanediol, diacetone alcohol, and N-methylpyrrolidone.

In the composition of the present invention, the weight ratio of the component (C) is from 5 to 5 based on 100 parts by weight of the solid content of the component (A).
0 parts by weight (preferably 10 to 30 parts by weight). Within this range, the storage stability of the composition of the present invention can be enhanced.

The pH of the composition of the present invention is from 6.0 to 9.0.
0 (further 7.0 to 8.5) is preferable from the viewpoint of improving storage stability. If the pH is higher than 9.0, the storage stability may decrease. If it is less than 6.0, mechanical stirring stability may not be ensured.

In addition, the osmotic water-absorbing material composition of the present invention may contain, if necessary, inorganic coloring pigments, organic coloring pigments, and film-forming materials which are commonly used in paints, as long as the effects of the present invention are not impaired. Auxiliaries, extenders, preservatives, fungicides, defoamers, leveling agents, pigment dispersants, anti-settling agents, anti-sagging agents, p
Additives such as H buffering agents and matting agents may be used alone or in combination.

By applying the permeable water-absorbing material-containing composition of the present invention to a cement-based substrate, it is possible to form a permeable water-absorbing preventing layer having water-absorbing properties and durability. Further, by laminating a top coat material, water resistance, weather resistance, stain resistance, and the like can be further improved.

The means for applying the composition containing a permeable water-absorbing material according to the present invention is not particularly limited, and a known coating method such as brush coating, spray coating, roller coating, roll coater, flow coater and the like is used. be able to. The coating amount of the permeable water-absorbing material-containing composition may be appropriately set depending on the type of the material to be coated or the type of the substrate, but is usually the total solid content of the acrylic synthetic resin emulsion and the silane-based permeable water-absorbing material. And 25 g / m ^{2 to} 250 g /
do the painting in m ² about the coating with the amount. By coating with such a coating amount, a water absorption preventing layer having sufficient water absorption preventing property, durability, and the like can be obtained.

In order to maintain the original texture of the cement base material, a composition containing a clear water-absorbing material having a clear property may be applied.

[0033]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

Using acrylic resin emulsions, silane-based osmotic absorption inhibitors, and organic solvents shown in Tables 1 and 2,
A composition containing a permeable water-absorbing preventive material was prepared according to the formulation shown in Table 3 and tested.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

(Test Method) (1) Penetration Depth The prepared permeable water-absorbing material-containing composition was stored at room temperature for 1 day, at room temperature for 30 days, and at 50 ° C. for 30 days. 75 × 20mm)
The upper surface was coated at a coating amount of 200 g / m ² and cured at room temperature for 7 days. Thereafter, the specimen was split, and the penetration depth was measured. (2) Efflorescence resistance Mortar (dimensions: 75 × 75 × 20 mm) is prepared using water and a powder obtained by mixing cement, No. 5 silica sand, and iron oxide pigment in a ratio of 1: 3: 0.01. Produced. Next, each of the permeable water-absorbing material-containing compositions was stored at room temperature for 1 day, at room temperature for 30 days, and at 50 ° C. for 30 days, and was coated on the upper surface of the prepared mortar at a coating amount of 300 g / m ^2. The test piece was sealed with a solvent-free two-liquid epoxy resin. After curing at room temperature for 3 days, the test specimen was half-submerged in water, and the state of efflorescence generation after standing for 2 weeks was visually evaluated. The evaluation was as follows. ：: Almost no eflorescence occurs. Δ: Partial eflorescence occurs.

Table 4 shows the test results. (Examples 1 to 4) The permeable water-absorbing inhibitor-containing composition of the present invention exhibited high permeability and efflorescence resistance even after long-term storage. In particular, in Examples 2 to 5 containing a hydrophilic organic solvent, a decrease in permeability was hardly observed.

(Comparative Examples 1 to 3) The initial permeability was high, but after long-term storage, the permeability clearly decreased, and the efflorescence resistance also deteriorated.

[0041]

[Table 4]

[0042]

The composition containing a permeable water-absorbing material according to the present invention has good storage stability and does not decrease the permeability even when coated after long-term storage, and can form a water-repellent layer inside the substrate. And the formation of a film on the surface of the substrate. Further, by containing a specific organic solvent, the storage stability can be further increased, and the permeability to the cement base material can be increased.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) E04B 1/66 E04B 1/66 A F term (Reference) 2E001 DA01 DH25 GA06 HA01 HA04 HD11 4G028 CA02 CB04 CB08 CC01 CD02 4J038 CG011 CG031 CG061 CG071 CG141 CH031 CH041 CH121 CH201 CH221 GA06 JC32 KA06 KA09 MA08 MA10 NA04 PC04

Claims (2)

[Claims] 1. An acrylic synthetic resin emulsion containing (A) 100 parts by weight in terms of solids, (B) 30 to 400 parts by weight in terms of solids of a silane-based permeable water-absorbing material, and (A) 1.) In the acrylic synthetic resin emulsion, the carboxylic acid-containing monomer is used in an amount of 2.
A composition containing a permeable water-absorbing preventive material, wherein the composition contains 0% or less. 2. The method according to claim 1, further comprising: (C) a solubility in water of 20 wt.
The permeable water-absorbing inhibitor-containing composition according to claim 1, wherein the composition contains 5 to 50 parts by weight of an organic solvent in an amount of 5 to 50% by weight.