JP2705869B2 - Sealer composition for preventing seepage of contaminants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealer composition for preventing bleeding of contaminants, which is used for coating and finishing walls and ceilings of buildings and for repainting a stained surface after coating. .

[0002]

2. Description of the Related Art In recent years, the surfaces of interior materials such as walls and ceilings of buildings are often coated with paint. The painted surface thus finished is contaminated with tobacco smoke, grit, oil, various seasonings, blood, etc. over time. Repainting is performed. These paintings and re-paintings include safety aspects,
A water-based paint excellent in hygiene is often used, but when the water-based paint is applied, in the case of finish coating, the water-soluble component contained in the base material is dissolved in water, which is the paint solvent. It may ooze out and make the finished surface dirty. Also,
In the case of re-painting for concealing a contaminated portion, a water-soluble component of contaminants such as hand stains dissolves in water, which is also a paint solvent, and oozes out to stain the finished surface, which is a problem. For this reason,
Prior to painting, a method is often used in which a sealer made of a solvent-based resin or aqueous cationic resin is applied to the surface to be coated to prevent water-soluble components from oozing on the painted surface of the aqueous paint. Have been.

[0003]

However, when a solvent-based resin is used as a sealer, there are many problems in terms of safety and hygiene such as flammability due to the volatile nature of the solvent and adverse effects on the human body by inhalation. . In addition, since some components and contaminants of the base material are dissolved in a solvent, there is also a problem that bleeding occurs at the time of sealer coating and the coating surface becomes dirty. On the other hand, cationic emulsions have the function of trapping contaminants,
To achieve this effect, it is necessary to cover the surface of the contaminant with a sufficiently dense film. However, with a conventional cationic emulsion, it is difficult to form a dense film, and with a water-soluble cationic resin, the water resistance is insufficient,
There is a problem that contaminants easily ooze out in a high humidity environment.

[0004] The present invention has been made in view of such circumstances, and an object of the present invention is to provide an aqueous sealer composition having an excellent effect of preventing oozing of contaminants.

[0005]

In order to achieve the above object, the present invention provides an aqueous medium containing a copolymer mainly composed of the following components (A) and (B). The molecular structure of the polymer is such that the structural unit derived from the component (A) is 5 to 99.5% by weight of the copolymer, and the structural unit derived from the component (B) is 0.5% by weight of the copolymer. A first aspect is a sealer composition for preventing contaminant leaching set to occupy ~ 95% by weight.

(A) A cationic alkali crosslinkable monomer represented by the following general formula (1).

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(B) An alkoxysilane monomer represented by the following general formula (2).

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[0008] In the aqueous medium, the above (A), (B)
And a copolymer containing the following component (C) as a main raw material, and the molecular structure of the copolymer is such that the structural unit derived from the component (A) is at least 5% by weight of the copolymer, The structural unit derived from the component (B) is 0.5% of the copolymer.
A second aspect of the present invention is a sealer composition for preventing seepage of contaminants, which is set so that the structural unit derived from the component (C) accounts for 94.5% by weight or less of the copolymer. A third aspect is a sealer composition for preventing seepage of contaminants in which a polymer obtained by polymerizing an ethylenically unsaturated monomer is dispersed and contained in one of two aqueous solutions. In a fourth aspect, a sealer composition for preventing seepage of contaminants, in which a pigment is dispersed and contained, is provided.

[0009]

In other words, the present inventors have focused on water-soluble resins, especially acrylic resins, in order to find a sealer composition for preventing the leaching of contaminants that is water-based and has extremely excellent leaching-preventing performance and water resistance. Conducted a series of studies. As a result, when the special monomers (components A and B) represented by the general formulas (1) and (2) are copolymerized at a specific ratio, the obtained chain polymer is It has been found that the resin exhibits good solubility, and since the aqueous solution forms an extremely dense film by volatilization of water, it exhibits excellent bleeding-prevention performance that cannot be obtained with conventional emulsion resins. In addition, not only the dense film prevents the exudation of the contaminants, but also the contaminants usually having an anion charge are trapped in the polymer due to the cationic property of the general formula (1). It turned out that the confinement effect of the thing was large. And since the sealer composition of the present invention is dried and the moisture in the film is lost and the cross-linking of the film is advanced to form a complicated three-dimensional network structure, the obtained film has water resistance and solvent resistance. It has very high properties and does not seep out contaminants even under high temperature and high humidity environment.

The same effect as described above can be obtained by dispersing an appropriate water-dispersed emulsion or pigment in the water-soluble resin.

Next, the present invention will be described in detail.

Water is the most suitable medium for use in the present invention. However, an organic solvent which is easily soluble in water may be used in combination for the purpose of increasing the solubility of the cationic alkali crosslinkable monomer to be copolymerized or increasing the permeability to the substrate. Further, only an organic solvent easily soluble in water may be used. Examples of such organic solvents include methanol, ethanol, propanol, acetone, methyl ethyl ketone, dioxane, ethylene glycol, propylene glycol, glycerin, methyl carbitol, ethyl carbitol, butyl carbitol,
Examples thereof include methyl cellosolve, ethyl cellosolve, acetic acid, acetates of the alcohol, acetates of the carbitol, acetates of the cellosolve, and the like. When such an organic solvent is used in combination, from the viewpoint of safety of the obtained sealer composition, 5% of the whole medium is used.
It is preferably used in the range of 0% by weight (hereinafter abbreviated as "%"), particularly preferably in the range of 20% or less. When the above-mentioned organic solvent is used, it may be recovered by distillation or the like after completion of the polymerization reaction.

The cationic alkali crosslinkable monomer (component A) represented by the general formula (1) includes a halogenated salt of dimethylaminomethylacrylamide epichlorohydrin adduct and dimethylaminopropylacrylamide epichlorohydrin adduct. Halogenated salts and alkyl sulfonates, halogenated salts of dimethylaminopropyl methacrylamide epichlorohydrin adduct and alkyl sulfonates, halogenated salts of dimethylaminomethylacrylic ester epichlorohydrin adduct,
Halogenated salt of dimethylaminomethyl methacrylic ester epichlorohydrin adduct, halogenated salt of dimethylaminopropyl acrylic ester epichlorohydrin adduct, halogenated salt of dimethylaminopropyl methacrylic ester epichlorohydrin adduct and alkyl sulfonate, or corresponding epoxide I can raise my body. Examples of such an epoxide compound include compounds in which Q in the general formula (1) is represented by the following formula (3).

[0014]

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It is necessary that the cationic alkali cross-linking type monomer is blended at a ratio of 5% or more to all the monomers. That is, when the cationic alkali cross-linking type monomer is less than 5%, the cross-linking density, water resistance, solvent resistance, and moisture resistance of the resulting film are insufficient, and the effect of preventing oozing of contaminants is reduced.

On the other hand, examples of the alkoxysilane monomer (component B) represented by the general formula (2) include vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethylmethoxysilane and the like. It is necessary to mix the above alkoxysilane monomer in a ratio of 0.5% or more based on all monomers. That is, the alkoxysilane monomer is 0.5%
If the amount is less than the above, as in the case of the cationic alkali crosslinkable monomer, the effect of preventing contaminant oozing of the obtained film is reduced.

Further, the ethylenically unsaturated monomers which can be used together with the above component A and component B include hydrophobic compounds such as vinyl acetate, alkyl acrylate, alkyl methacrylate, styrene, acrylonitrile and methacrylonitrile. Monomer. These may be used alone or in combination of two or more. When a polymer is produced from the above ethylenically unsaturated monomer, acrylic acid, methacrylic acid, amides of acrylic acid or methacrylic acid, methylolated amides, alkoxymethyl may be used together with the above hydrophobic monomer. Amides, alkylaminoesters, cationic alkali crosslinkable monomers represented by the above general formula (1), hydrophilic monomers such as monochlorovinyl acetate, 1-chloro-2-hydroxypropyl acrylate Is done. These may be used alone or in combination of two or more. Needless to say, the above-mentioned hydrophilic monomer is used in such a range that the produced polymer is not soluble in the aqueous medium. The above-mentioned ethylenically unsaturated monomer is copolymerized with the above-mentioned components (A) and (B), or is emulsion-polymerized separately from the above-mentioned components (A) and (B) to obtain an emulsion resin. It is preferable to mix with a medium containing the copolymer (A) + (B).

The sealer composition for preventing contaminant bleeding of the present invention can be produced using the above-mentioned medium and monomer, for example, as follows. That is, first, a polymerization initiator is added to water or an organic solvent or a mixture of water and an organic solvent, which is a polymerization medium, and the cationic alkali cross-linkable monomer, alkoxysilane The monomer and the ethylenically unsaturated monomer are polymerized at 60-90 ° C for 1-5 hours. If necessary, a chain transfer agent such as 2-mercaptoethanol is added in advance for the purpose of controlling the molecular weight. After the polymerization, if necessary, various additives, for example, film-forming aids such as butyl cellosolve, butyl carbitol, and acetate,
Antifoaming agents, pigments, thickeners and the like can be added.
In this way, the desired contaminant exudation prevention sealer composition can be obtained.

In the case where the ethylenically unsaturated monomer is separately emulsion-polymerized, a known emulsion polymerization method may be used. Then, the obtained emulsion is mixed with a medium containing the copolymer (A + B or a copolymer composed of A + B + ethylenically unsaturated monomer) to obtain a target contaminant oozing prevention sealer composition. be able to.

In the above-mentioned production method, it is necessary to select and use a medium which does not inhibit the polymerization reaction. And, as the polymerization initiator, benzoyl peroxide,
Examples include azobisisobutyronitrile, 2,2'-azobisaminodipropane hydrochloride, and ammonium persulfate.
Further, keeping the medium acidic is important to prevent the system from gelling during the polymerization, and the pH adjusting acid may be an organic acid such as formic acid, acetic acid, oxalic acid, or hydrochloric acid. , Sulfuric acid, nitric acid and the like.

Further, in the above-mentioned production method, when a pigment is compounded, it is preferable to avoid using an alkaline pigment as much as possible. This is because if the pigment is alkaline, aggregation may occur at the time of blending. Therefore, as the pigment, titanium oxide, clay and the like are preferable.

The sealant composition for preventing contaminant leaching of the present invention obtained as described above is used for preventing leaching of impurities on the surface of a base material such as concrete, mortar, slate board, scalp board and ALC board before finishing the coating. Alternatively, it is applied to the surface of a base material or a contaminated painted surface for the purpose of exuding contaminants when repainting the painted surface. The sealer composition, by being coated, traps contaminants (including impurities that can leach from the substrate) due to its own cationic charge, and forms a dense film by crosslinking the film by water evaporation. It becomes a film with excellent water resistance and solvent resistance, and completely prevents the exudation of contaminants on the film surface.

Next, examples will be described together with comparative examples.

[0024]

Examples 1 to 6 and Comparative Examples 1 to 6 100 parts by weight of isopropyl alcohol (hereinafter abbreviated as "parts") were added to a polymerization flask equipped with a stirring blade, a thermometer and a reflux condenser.
A monomer raw material having the composition shown in Tables 1 and 2 below was charged, and 1 part of azobisisobutyronitrile as a polymerization initiator and lauryl mercaptan 1 as a chain transfer agent were added.
The polymerization reaction was carried out at 80 ° C. for 5 hours with stirring. Then, isopropyl alcohol was completely replaced with water using a vacuum distillation apparatus to obtain a desired sealant composition for preventing seepage of contaminants. Each of the compositions was a uniform solution and had a polymer concentration of 30%. This is 15
% Was diluted with water to obtain a sample.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

Examples 7 and 8 Using the sample of Example 1, a pigment was blended according to Table 3 below to obtain a sealer composition containing the pigment.

[0028]

[Table 3]

With respect to these examples and comparative examples, the performance of preventing contaminant leaching was evaluated according to the following method.
The results are shown in Tables 4 and 5 below.

<Evaluation Method of Contaminant Leaching Prevention Performance> First, three types of contaminated coated boards were prepared as follows. Preparation of stain-contaminated coated plate A slate plate coated with an acrylic synthetic resin emulsion paint (white) is sealed in a desiccator with two suction ports, a suction pressure is reduced from one port, and a cigarette ignited from the other port To inhale the tobacco smoke into the desiccator and contaminate the coated board. Production of stain-contaminated coated plate Gypsum board was coated with commercially available soy sauce to obtain a coated plate. Production of blood-contaminated coated plate Commercially available blood (horse) was applied to a gypsum board to obtain a coated plate.

Next, about 100 g / m ² of each of the samples of Examples and Comparative Examples was applied to each of the above-mentioned contaminated coated plates and dried at room temperature for 1 day. (White) was applied at about 400 g / m ² . Coating was performed twice with a brush at an appropriate interval.
After drying for 3 days, the state of bleeding of contaminants onto the painted surface was evaluated. The evaluation was made in the following three-step evaluation. ○… No bleeding △… Some bleeding × …… Less bleeding

[0032]

[Table 4]

[0033]

[Table 5]

From the above results, it can be seen that all of the products of the examples have excellent performance of preventing contaminant leaching as compared with the products of the comparative examples.

[0035]

Example 9 Using the sample of Example 6, a cationic acrylic emulsion (Iodosol AF9) was prepared according to Table 6 below.
41, manufactured by Kanebo NS Co., Ltd.). And also about this sealer composition, the contaminant exudation prevention performance was evaluated similarly to the above. The results are shown in Table 6 below.

[0036]

[Table 6]

From the above results, it can be seen that even if an insoluble polymer emulsion is separately prepared and mixed with the above-mentioned example product, an excellent sealer composition for preventing seepage of contaminants can be obtained.

[0038]

As described above, the sealer composition for preventing contaminant leaching of the present invention contains a copolymer obtained by blending two kinds of special monomers in a specific ratio. The resulting chain polymer exhibits good solubility in water, and the aqueous solution forms an extremely dense film by volatilization of water. Therefore, this sealer composition can exhibit excellent bleeding prevention performance that cannot be obtained with conventional emulsion-based ones. In addition, not only the dense film prevents the exudation of contaminants, but also the general formula (1)
Due to the cationic nature of the polymer, contaminants usually having an anionic charge are trapped in the polymer, so that the contaminants are largely confined. And the sealer composition of the present invention,
As drying progresses and moisture in the film is lost, crosslinking of the film proceeds to form a complicated three-dimensional network structure. The resulting film has extremely high water resistance and solvent resistance,
Even in a high humidity environment, there is an effect that contaminants and the like do not exude.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08F 220/36 C08F 220/36 220/58 220/58 230/08 230/08

Claims (4)

(57) [Claims] 1. An aqueous medium contains a copolymer mainly composed of the following components (A) and (B), and the molecular structure of the copolymer is derived from the component (A). The structural unit is set so as to occupy 5 to 99.5% by weight of the copolymer, and the structural unit derived from the component (B) accounts for 0.5 to 95% by weight of the copolymer. A sealer composition for preventing contaminant exudation. (A) A cationic alkali crosslinkable monomer represented by the following general formula (1). Embedded image (B) An alkoxysilane monomer represented by the following general formula (2). Embedded image 2. An aqueous medium contains a copolymer having the above-mentioned components (A), (B) and the following component (C) as a main raw material, and the molecular structure of the copolymer is as described in the above (A). The structural unit derived from the component is at least 5% by weight of the copolymer, and the structural unit derived from the component (B) is 0.5% by weight of the copolymer.
A sealer composition for preventing seepage of contaminants, wherein the structural unit derived from the component (C) accounts for at least 94.5% by weight of the copolymer. (C) an ethylenically unsaturated monomer. 3. A sealer composition for preventing seepage of contaminants, wherein a polymer obtained by polymerizing an ethylenically unsaturated monomer is dispersed and contained in the aqueous liquid according to claim 1. . 4. A sealer composition for preventing seepage of contaminants, wherein the aqueous liquid according to claim 1 contains a pigment dispersed therein.