JP2626940B2 - Aqueous topcoat agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building, a concrete inside and outside a building, which has been remarkably growing in consumption of paint in recent years.
The present invention relates to the coating of a wall surface such as a cement or mortar surface, a bathroom wall surface, a top coat of each of the above-mentioned finishing coating materials, particularly a base emulsion for a top coat of a multilayer elastic paint.

[0002]

2. Description of the Related Art In recent years, in various paints and adhesives,
In the context of the revision of the Fire Service Law to avoid fire danger and the strengthening of various pollution regulations, systems containing a large amount of organic solvents are being further shunned, and the demand for water-based systems is increasing more than ever. Water-based emulsion paints and adhesives are not only water-based, pollution-free, and safe without fire and other dangers, but also do not contaminate the work environment due to solvent vapor even in narrow indoor installations. There is an advantage in that the workability of the equipment is excellent, and in particular, it is possible to switch from the solvent system without changing the existing equipment.

In particular, in the case of aqueous paints, various performances required as a topcoat agent for paints, for example, JIS
The performance of the coating film elongation, adhesion strength, hot / cold repetition test and the like specified in A-6910, K-5660, etc. can be sufficiently overcome in the prior art, but the coating film portion is It is said that it is inevitable that the middle coat layer and the top coat layer are separated from each other when water is immersed in water or dew condensation occurs on the painted surface, so-called blisters can be blistered. Or equivalent products are not available on the market, and despite the conventional requirements of the Fire Service Law for organic solvents and problems such as environmental pollution, solution-type urethane
An acrylonitrile or acryl one-pack topcoat agent has been used.

[0004]

SUMMARY OF THE INVENTION The present invention has various properties required as a topcoat agent for a multilayer elastic paint,
It also aims to develop a water-based topcoat agent that can be supplied at a reasonable price without pollution of the working environment in response to the requirements of the Fire Service Law and the Labor Safety Law.

[0005]

That is, in the present invention, 5 to 90% by weight of the macromonomer represented by the general formula I or II is used.

Embedded image

Embedded image And 95 to 10% by weight of PDMS represented by the general formula III

Embedded image The above object was achieved by developing a topcoat agent containing an acrylate-based copolymer emulsion containing at a ratio of 1: 1.

In particular, [A] silicon-based macromonomer 5
A monomer consisting of 0.5 to 60% by weight of a silicon component in a proportion of 90 to 90% by weight and 95 to 10% by weight of PDMS, 99.5 to 10% by weight of acrylate and / or methacrylate, and 0 to 50% by weight of a copolymerizable monomer A simple composition comprising 5 to 90 parts by weight of a silicone-containing acrylate copolymer emulsion obtained by emulsion polymerization of the composition, 50 to 100% by weight of [B] acrylate and / or methacrylate, and 50 to 0% by weight of a copolymerizable monomer. The above object was achieved by using a composition comprising at least 95 to 10 parts by weight of an acrylate copolymer emulsion obtained by emulsion polymerization of a monomer composition as a base polymer of an aqueous topcoat agent. Things.

In this case, when the amount of the macromonomer in the silicon component composed of the polymerizable macromonomer and the non-polymerizable PDMS is more than 90% by weight, blisters tend to occur, and the stipulation specified in JIS A-6910. In a test for resistance to the repeated action of heating and cooling, cracks tend to occur, so a mixing ratio of less than this is preferred. If it is less than 5% by weight, there is no particular problem in the initial stage of coating, but blistering tends to occur as time passes. Therefore, it is preferable to blend 5% by weight or more.

This silicone component is mixed with an acrylate and / or methacrylate, and, if necessary, a copolymerizable monomer for emulsion polymerization. In this case, the total amount of the silicone component in the monomer composition is 0.5% by weight
It is necessary to mix the above. If the amount is less than 0.5% by weight, the blister resistance decreases. Also, this blending amount is up to about 60% by weight from the viewpoint of price because there is no improvement in blister resistance.

As the acrylate and / or methacrylate used for copolymerizing with the silicon component, there can be mentioned ordinary acrylates and methacrylates. For example, methyl (meth) acrylate,
Ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-
Hydroxyethyl (meth) acrylate and the like and mixtures thereof.

[0010] The content of these components is 99.5 to 10% by weight in order to reduce the cost by increasing the mixing ratio and to improve the blister resistance by increasing the mixing ratio. Styrene, vinyl toluene, vinyl acetate, vinyl propionate, vinyl versatate, ethylene,
It can be easily selected from monomers generally used for binders for building paints, such as vinyl chloride, vinylidene chloride, (meth) acrylonitrile, (meth) acrylic acid, and itaconic acid. The compounding ratio is 0 to 50% by weight of the whole monomer composition. A compounding amount exceeding 50% by weight should be avoided because it deteriorates the performance such as adhesion to the intermediate coating layer and blister resistance.

In the emulsion polymerization of these monomer compositions, emulsifiers (surfactants), polymerization initiators and the like which are generally used in the art are used, and preferably, a high-speed emulsifying apparatus is used to prepare the emulsion composition. 0.1-0.6 μm monomer particle size
It is preferable to use it after adjusting so as to fall within the range.

The silicone-containing acrylate copolymer emulsion thus obtained is prepared according to JIS A-
6910, JIS K-5660 and other coating emulsions satisfying the performance, such as acrylate and / or methacrylate (copolymerizable monomer is up to 50% by weight.
It may be contained. ) As a main component and blended into an acrylic ester copolymer emulsion for coating.

The acrylate in this case is, for example, a (meth) acrylate of an alcohol having 1 to 8 carbon atoms, and styrene is mainly used as the copolymerizable monomer. This is an emulsion obtained by emulsion polymerization according to a conventional method, and preferably has a particle diameter of 0.1 to 0.2.
It is an acrylate emulsion having a μm, a minimum film formation temperature (MFT) of 0 to 35 ° C, and a glass transition temperature (Tg) of -20 to 25 ° C.

With respect to the mixing ratio, the total amount of the macromonomer and PDMS is 0.025 to 54% by weight, preferably 0.1 to 50% by weight based on the total solid content of the top coat agent, based on the total solid weight after compounding. It needs to be 50% by weight. When the ratio of the solid component of the silicon component to the total solid component of the topcoat agent is less than 0.025% by weight, the blister resistance becomes insufficient when the topcoat agent is used, while the ratio of the solid component is greater than 54% by weight. In some cases, not only the gloss of the painted surface is reduced and the stain resistance is reduced, but also the base emulsion becomes extremely expensive and unsuitable.

[0015]

The reason why the blister resistance can be greatly improved without deteriorating the performance as a top coat paint of another paint emulsion mixed with a top coat agent using the base polymer for a top coat of the present invention could not be clarified. However, it is presumed that the reasons are as follows.

That is, when a polymerizable macromonomer is formed into a copolymer emulsion in the presence of non-polymerizable PDMS, together with another (meth) acrylate-based monomer, and in some cases, a copolymerizable monomer, the results are considered as follows. Lever coatings have their PDMS chains selectively localized to the surface of the topcoat layer due to their low surface energy, which significantly renders the coating surface hydrophobic and allows water to enter the coating. Is considered to be extremely suppressed, and P
As a result of the localization of the DMS chain on the air-side surface, the PDMS chain concentration at the interface with the intermediate coating layer is considered to be lower than the average value, and it is considered that the adhesion is not inhibited.

In this case, the fact that the non-polymerizable PDMS is stably present in the emulsion without being separated from the aqueous medium means that the macromonomer forms a polymer chain in the polymer emulsion particles, and interacts strongly with the PDMS chain. This is because it is exposed to air and changes the bonding strength with PDMS as it is formed into a film.To form an emulsion with such a function, non-polymerizable PDMS coexists when performing emulsion polymerization. I think that is why it is necessary.

[0018]

The following examples illustrate the present invention. (Example 1) As a silicon component, a macromonomer (FM
-0711, manufactured by Chisso Corporation) 10 parts by weight, PDMS
(SH200-100,000, manufactured by Dow Corning Toray Co., Ltd.) 10 parts by weight of methyl monomer, 11.3 parts by weight of methyl methacrylate, 30.3 parts by weight of 2-ethylhexyl acrylate, and 34.4 parts by weight of styrene as a copolymerizable monomer. Of water and 2 parts by weight of 2-hydroxyethyl methacrylate and 2 parts by weight of methacrylic acid were adjusted to a concentration of 40% by weight. As an emulsifier, a mixture of 1 part by weight of an anionic surfactant (Perex OTP) and 3 parts by weight of a nonionic surfactant (Emulgen 931) was used in an amount of 1 part by weight based on the entire system, and the mixture was emulsified in advance by a homogenizer. An emulsion having an average particle size of 0.423 μm was obtained. The polymerization reaction was carried out under the following conditions using an emulsion-drop method. N ₂ substitution 30 minutes Precharge Monomer emulsion 5% Catalyst AIBN Start of reaction 72 ° C Reaction temperature / Drip time 80 ± 1 ° C / 3 hours Aging temperature / time 80 ± 1 ° C / 2 hours Both obtained silicon-containing acrylic ester The solid content of the polymer emulsion (emulsion I) is 40.3% by weight
Met. Further, as an acrylic ester copolymer emulsion for coating (emulsion II), Polysol AP-37 used as a base emulsion for coating is used.
50 (manufactured by Showa Polymer Co., Ltd.) (solid content: 50% by weight) was used. The emulsions I and II were blended at a ratio of 1/9 to obtain a base coat base polymer. The properties are as follows. Concentration: 49.0% by weight Viscosity (cps): 3100 (10 rpm, 30 ° C.) pH: 8.6 Particle size: 0.14 μm MFT: 23 ° C. The above base polymer is made into a paint by a known method, and an elastic paint top coat agent A performance evaluation test was performed.

Example 2 Emulsion prepared under exactly the same conditions as in Example 1 except that the ratio of the macromonomer used as the silicon component to PDMS was 4 parts by weight / 16 parts by weight.
The sample prepared in Example 2 was prepared by mixing II and adjusting the composition.
The properties are as follows. Concentration: 49.0% by weight Viscosity (cps): 4000 (10 rpm, 30 ° C.) pH: 8.7 Particle diameter: 0.18 μm MFT: 21 ° C.

Comparative Example 1 Polysol AP-3750
(Manufactured by Showa Polymer Co., Ltd.) was used as a sample. The properties are as follows. Concentration: 50% by weight Viscosity (cps): 5000 (10 rpm, 30 ° C.) pH: 9 Particle size: 4.5 (DQ value) MFT: 24 ° C.

Comparative Example 2 PDMS as a Silicon Component
Was prepared and adjusted under the same conditions as in Example 1 except that the macromonomer was used in an amount of 20 parts by weight, and a sample of Comparative Example 2 was used. The properties are as follows. Concentration: 49.0% by weight Viscosity (cps): 2800 (10 rpm, 30 ° C.) pH: 8.6 Particle size: 0.20 μm MFT: 23 ° C.

The clear film was dried with a dryer at 60 ° C. because of no plasticizer. In Table 1, "initial" means that the drying time was 1 hour, and "after aging" means that the material was further dried at 60 ° C. for several hours or left at room temperature for several days.

The measurements other than the gloss shown in Table 2 were conducted by applying a water-based elastic tile 21 (East Japan Paint Co.) as an intermediate coat to a slate plate for an experiment, and then applying a sample topcoat agent thereon.

As a measuring method, water repellency (JIS K-
5660), water permeability (JIS K-5403), gross (JIS K-5660), and initial water resistance are evaluation criteria for blistering of the Japan Paint Inspection Association, and stain resistance (JIS K-5
5660).

For the degree of swelling, an aqua film of an emulsion is prepared by casting, glued on a glass plate, and the periphery is sealed with a sealing agent to prepare a test piece.
This was immersed in water at 23 ° C. for 48 hours, and the swelling ratio was determined from changes in both weight and size. The results of the above Examples and Comparative Examples are summarized in Tables 1 and 2 below.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

The polymer emulsion composition obtained as described above has a performance that can be put to practical use in place of a solvent-based product currently used as a top coat agent for a so-called multilayer elastic paint. Since it is a water-based product, there is no concern about environmental pollution due to solvent volatilization, worker health hazards, fire hazards, etc., and it is greatly reduced in terms of resource saving and extremely easy handling. Use is expected.

Claims (2)

(57) [Claims] 1. A compound represented by the general formula I or II (hereinafter referred to as a macromonomer).
5 to 90% by weight Embedded image And 95 to 10% by weight of a compound represented by the general formula III (hereinafter referred to as PDMS). A top coat agent comprising an acrylate copolymer emulsion containing at a ratio of: 2. [A] 5 to 90% by weight of macromonomer and 95 to 10% by weight of PDMS 0.5 to 60% by weight of silicon component 99.5 to 10% by weight of acrylate and / or methacrylate Copolymerizable monomer 0 5 to 90 parts by weight of a silicone-containing acrylate copolymer emulsion obtained by emulsion polymerization of a monomer composition consisting of 50 to 100% by weight and [B] acrylate and / or methacrylate 50 to 100% by weight copolymerizable monomer An aqueous topcoat agent comprising 95 to 10 parts by weight of an acrylic ester copolymer emulsion obtained by emulsion polymerization of a monomer composition of 50 to 0% by weight.