JPH111656A - Aqueous primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aq. primer compsn. improved in permeation into various substrates, adhesive properties, reinforcing properties, water resistance. etc., by compounding a styrene-acrylic ester copolymer resin emulsion having a specified glass transition point, an urethane-modified ethylene-acrylic acid copolymer resin emulsion having a specified softening point, a fine silica powder, etc. SOLUTION: 100 pts. styrene-acrylic ester copolymer resin emulsion having a glass transition point of 0-30 deg.C is compounded with 5-100 pts. urethane- modified ethylene-acrylic acid copolymer resin emulsion having a softening point of 85-100 deg.C and/or 5-100 pts. ethylene-acrylic acid copolymer resin emulsion having a softening point of 85-100 deg.C and 0.2-5 pts. fine silica powder. This primer, as a compsn. for wall repairing, contains a fine silica powder as an essential component to increase the water-repellent effects and hence exhibits an excellent waterproofness. The silica powder used has a particle size of 5-50 μm and a specific surface area of 100-500 m<2> /g and is compounded in amt of 0.2-5 pts. per 100 pts. resin emulsion mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial application] Moderate permeability and adhesion to various substrates. Reinforcement, water resistance. The present invention relates to a water-based primer that retains water repellency and has excellent waterproof performance.

[0002]

2. Description of the Related Art Conventionally, house painting is generally performed by:
Many simple mortars that can only be painted from above are used. In this general method, the outer wall is exposed to rain and sunlight for a long period of time, and the painted surface and mortar are destroyed by ultraviolet rays and rain (acid rain), etc., and the waterproof performance is lost. There is a risk of corroding rafters, laths, etc. contained in them. Alternatively, since the sea sand containing a lot of salt is contained, drilling of cement etc. comes out to the outside and causes various causes such as mold, stains, cracks, salt damage, etc., which causes the service life of the building to be shortened. Even after repainting, the same phenomenon occurs a few years later, and there is a risk that the makeup will simply be applied.

[0003]

When renovating the exterior wall of a building, not only repairing the deteriorated and damaged parts,
It is required to improve the durability such as imparting an impregnating reinforcement effect to various conventionally applied base materials such as mortar and concrete, or imparting water repellency. On the other hand, a composition using a water-soluble resin is sometimes used due to its excellent permeability, but a water-soluble resin alone has excellent permeability and reinforcing properties, but is poor in water resistance and water repellency and waterproof. It is not enough as a composition having excellent performance.

In the waterproofing method, the primer must have sufficient adhesion to various base materials (mortar, resin paint, plastic, aluminum, copper plate, etc.).
Some solvent-based resins can be used, but no water-soluble resin has yet been found that can be sufficiently used.

[0005]

Means for Solving the Problems The present inventors are water-based primers, and have a property of permeability, adhesion, reinforcement,
As a result of intensive studies to obtain a material having excellent water resistance and water repellency, the present invention was found. That is, the present invention relates to 100 parts of a styrene acrylate copolymer resin emulsion having a glass transition temperature of 0 to 30 ° C., and a softening point of 8 parts.
5 to 100 parts of a urethane-modified ethylene acrylic acid copolymer resin emulsion having a range of 5 to 100 ° C and / or 5 to 100 parts of an ethylene acrylic acid copolymer resin emulsion having a softening point of 85 to 100 ° C.
Parts, and 0.2 to 5 parts of fine silica powder.

The styrene acrylate copolymer resin emulsion has a glass transition temperature (Tg) of 0 to 30.
In the range of ° C., specifically, trade names YJ (product of Mitsubishi Yuka Badesh Co., Ltd.) and VOCOAT (product of Dainippon Ink Co., Ltd.) can be used. When a styrene acrylate copolymer resin emulsion having a glass transition temperature of 0 to 30 ° C. is used, the time from application to various structures to development of adhesion performance is short, but the glass transition temperature is 0 to 30 ° C.
When an emulsion other than 30 ° C. is used, the time until the adhesive performance is developed becomes long, and it is not suitable as a primer of the composition for wall surface repair.

When a urethane-modified ethylene acrylic acid copolymer resin emulsion having a softening point of 85 to 100 ° C. is used, it is effective in water resistance and water repellency.
C. or higher is not suitable as a wall surface repair composition because the elongation of the coating film is reduced. The combination ratio of the urethane-modified ethylene acrylic acid copolymer resin emulsion is 5 to 100 parts of the styrene acrylic acid ester copolymer resin emulsion.
100 parts, especially 10 to 50 parts, is preferred. Even if more than 100 parts are blended, the desired effect or more cannot be obtained. If the amount is less than 5 parts, the water repellency is reduced and the waterproof performance is reduced. As such a urethane-modified ethylene acrylic acid copolymer resin emulsion, Hitech (product of Toho Chemical Co., Ltd.) can be used.

When an ethylene acrylic acid copolymer resin emulsion having a softening point of 85 to 100 ° C. is used, it is possible to exhibit water resistance and water repellency. If the softening point is 100 ° C. or higher, the elongation of the coating film is reduced, so that it is not suitable as a primer for wall surface repair composition. The use ratio of the ethylene acrylic acid copolymer resin emulsion is 5 to 10 per 100 parts of the styrene acrylate copolymer resin emulsion.
If the amount is 0 part, especially 10 to 50 parts, and more than 100 parts are blended, the desired effect or more cannot be obtained. If the amount is less than 5 parts, the water repellency is reduced and the waterproof performance is reduced. As such an ethylene acrylic acid copolymer resin emulsion, Chemipal (a product of Mitsui Petrochemical Co., Ltd.)
Is mentioned.

The primer as the wall surface repair composition of the present invention contains finely divided silica as an essential component. It has been found that by adding finely divided silica, the effect of water repellency is amplified to improve the waterproof performance. Furthermore, it also has a sag preventing effect when the primer is applied to a wall surface. The finely divided silica preferably has a particle diameter of 5 to 50 μm and a specific surface area of 100 to 500 m ² / g. The amount of the fine powdered silica is 0.2 to 5 parts, preferably 0.3 to 5 parts, per 100 parts of the resin emulsion mixture.
Although it is in the range of 1.0 part, when the mixing amount is more than 5 parts, the thixotropy of the composition increases, the smoothness of the coating film at the time of construction is lost, and it becomes difficult to maintain a uniform thickness of the coating film, In addition, unevenness is produced in the finish, which is an aesthetic problem. On the other hand, when used in less than 0.2 parts, the repellent effect is reduced and the waterproof performance is reduced, and furthermore, the liquid is easily dripped when applied to the wall surface, and a uniform coating thickness can be obtained. I cannot do it.

The aqueous primer composition of the present invention has a temperature of -10.degree.
When frozen below, it does not return to the original emulsion even at room temperature, and the emulsion is broken and becomes gel-like, making it unusable. Therefore, when used in a cold region of -10 ° C. or lower, it is necessary to use an antifreezing agent in combination. By adding ethylene glycol and propylene glycol as antifreeze materials, the composition frozen at -10 ° C or lower restores the form of the original emulsion even at room temperature, and there is no change in performance from that before freezing. Things are obtained.
The amount of ethylene glycol and propylene glycol used as an antifreeze material is 0.5 to 100 parts of the emulsion.
It is preferable to add up to 5 parts. If the amount is more than 5 parts, especially when the base material is aluminum, the wettability of the coating film deteriorates, and a repelling phenomenon occurs. On the other hand, if the amount is less than 0.5 part, the effect of preventing freezing is lost, and even if the temperature is returned to room temperature after freezing, the emulsion cannot be restored to its original state and cannot be used.

The composition of the present invention can be prepared by mixing the above components. For example, after water is charged, finely powdered silica is mixed and dispersed with stirring so that lumps are not gradually formed. After confirming that the fine powder silica has been dispersed, a styrene acrylic acid copolymer resin emulsion is mixed and dispersed. Next, a urethane-modified ethylene acrylic acid copolymer resin emulsion or an ethylene acrylic acid copolymer emulsion is mixed and dispersed. Then, ethylene glycol is mixed and dispersed. Finally, the composition of the present invention can be prepared by filtration.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In addition, in the following examples, the compounding amount shows a weight part.
The components shown in Tables 1 and 2 were mixed in the amounts shown in the same table,
Tests were conducted on the adhesiveness to various substrates and the adhesive strength to commercial elastic coating materials in days, water repellency, water resistance, and low-temperature stability of each composition. The results are shown in Tables 1 and 2.

[0013]

[Table 1]

[0014]

[Table 2]

[0015] In the table, the adhesiveness to various base materials means that the product of Example and Comparative Example was applied to each of various base materials at 200 µm, and 3c was applied thereon.
A non-woven fabric cut into a width of m and impregnated with the composition is applied, cured at 20 ° C. for 7 days, and the non-woven fabric is bent at 180 °.
The adhesive strength and the state of peeling were observed by pulling with a spring balance.
When the composition had a cohesive failure of 80% or more,
0% to 80% cohesive failure: Δ, composition: 0% to 20%
Those with cohesive failure and 80 to 100% peeling of the interface between the composition and the skeleton were evaluated as x. The number of days in which the adhesive strength with the commercially available elastic coating material was exhibited was evaluated by the above-mentioned method after preparing a test specimen on the commercially available elastic coating material and aging the cured days for 1, 3, 7, and 10 days. . The water resistance test means that a test specimen was prepared on a commercially available elastic coating material by the above method and cured at 20 ° C. for 7 days.
The sample was immersed in water at 7 ° C. for 7 days, taken out, and evaluated one hour after the removal by the above-mentioned method. In the water repellency test, an example product and a comparative example product were coated on paper at 200 μm and cured at 20 ° C. for 7 days to obtain a test body. Water was dropped on the test body with a dropper and evaluated according to the following criteria. 〓: Water repellency is present △: Water repellency is slightly present X: No water repellency is present The low-temperature stability test is a stability test after freezing and thawing the composition, which is left at −10 ° C. for 24 hours and then at 20 ° C. for 24 hours. After standing for a time, the state of the composition was observed and evaluated according to the following criteria. 〓: No change from before freezing ×: The whole becomes gel-like In the table, SK emulsion is a styrene acrylate copolymer resin emulsion, UA emulsion is a urethane-modified ethylene acrylate copolymer resin emulsion, EA Emulsion is an abbreviation for ethylene acrylic acid copolymer resin emulsion.

[0016]

The water-based primer, which is the composition of the present invention, has appropriate permeability, adhesion, reinforcement, water resistance, and water repellency to various base materials. It has a great effect on repairing the wall surface of elastic paint that has been aged for many years.

Claims (1)

[Claims] 1. A styrene acrylate copolymer resin emulsion 100 having a glass transition temperature of 0 to 30 ° C.
Part to 5 to 100 parts of a urethane-modified ethylene acrylic acid copolymer resin emulsion having a softening point in the range of 85 to 100 ° C., and / or. Softening point 85 to 10
An aqueous primer composition comprising 5 to 100 parts of an ethylene acrylic acid copolymer resin emulsion at a temperature of 0 ° C. and 0.2 to 5 parts of fine silica powder.