JP5398104B2 - Water-based paint composition - Google Patents

Description

  The present invention relates to an aqueous coating composition capable of forming a coating film excellent in antibacterial properties.

  In recent years, efforts have been made to improve the environment in ordinary homes, workplaces, public facilities, and the like due to changes in the living environment and increased health consciousness. Examples of environmental improvements include volatile organic compounds (VOC) such as formaldehyde, tobacco smoke, pollen, fungi and other fungi. Among these, as a method for removing fungi, air purifiers equipped with highly-functionalized dust removal filters and products using photocatalysis are widely used.

Air purifiers, such as those equipped with a high-capacity filter called HEPA or ULPA, and those that inactivate floating fungi by discharging electrically generated ions into the air Some of them are intended to collect or inactivate fungi. In such an air purifier, air convection is actively caused by turning a fan, and a large amount of air can be processed in a short time.
However, the problem with air cleaners is that the collected fungi are concentrated on the filter and that electric energy is required for the motor, ion generator, and the like. For this reason, it is indispensable to perform maintenance for cleaning the felter, and it is actually used only in rooms where people are active at all times, such as in living rooms and offices.

In general, fungi such as molds are easy to propagate in a high humidity environment, and are easy to propagate in a bathroom, bathroom, toilet, etc. in a building. In general, paint and wallpaper containing antibacterial and antifungal agents are applied to the walls of these parts. As an example of such a paint, Patent Document 1 (Japanese Patent Laid-Open No. 4-300975) describes an antibacterial paint containing a metal having an antibacterial action or an inorganic antibacterial agent carrying ions thereof. However, even when such an antibacterial coating is applied to the wall surface, the antibacterial action only works on fungi that accidentally adhere to the surface of the coating film, and there is still room for improvement in terms of antibacterial properties.
On the other hand, a technique of imparting antibacterial properties to a wall surface with a paint or wallpaper containing a visible light responsive photocatalyst is also known. However, in many cases, toilets and the like are often placed in sites where lighting is difficult, and as an energy saving measure, the lights are often turned off except during use, so that sufficient performance may not be achieved.

Japanese Patent Laid-Open No. 4-300975

  The present invention has been made in view of the above-described problems, and is water-based that can exhibit excellent antibacterial performance even in parts such as a bathroom, bathroom, and toilet where moisture is high and lighting is insufficient. The object is to obtain a coating composition.

  As a result of intensive studies to achieve the above object, the present inventor contains a synthetic resin emulsion (a), an organosiloxane compound having an amino group (b), and a silver-based antibacterial agent (c) as essential components. The inventors have conceived an aqueous coating composition, and found that an excellent antibacterial performance is exhibited by the synergistic action of these components in the formed coating film of the aqueous coating composition, thereby completing the present invention.

（式中、Ｒ^１は同一または異なって、アルキル基、アリール基、アラルキル基を示し、Ｒ^２はアルキレン基を示す。Ｘはアミノ基示す。ｍ，ｎは１以上の整数である。）
That is, the present invention has the following characteristics.
1. Synthetic resin emulsion (a) (excluding the following (b)),
An organosiloxane compound (b) having an amino group containing a unit represented by the following formula (1) or (2);
A silver antibacterial agent (c), and a nitrogen-containing ring compound (d) containing an isothiazoline compound ,
1 to 100 parts by weight of the organosiloxane compound (b), 0.01 to 5 parts by weight of the silver-based antibacterial agent (c), and a nitrogen-containing ring with respect to 100 parts by weight of the solid content of the synthetic resin emulsion (a) A water-based coating composition comprising 0.01 to 5 parts by weight of the compound (d).

(In the formula, R ¹ is the same or different and represents an alkyl group, an aryl group, or an aralkyl group, R ² represents an alkylene group , X represents an amino group, and m and n are integers of 1 or more.)

  According to the aqueous coating composition of the present invention, a coating film exhibiting excellent antibacterial performance can be formed.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The aqueous coating composition of the present invention contains a synthetic resin emulsion (a), an organosiloxane compound (b) having an amino group, and a silver-based antibacterial agent (c) as essential components.

  Among these, the synthetic resin emulsion (a) (hereinafter referred to as “component (a)”) is a component that functions as a binder. Specifically, as the component (a), for example, vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicon resin, fluorine resin, or a composite system thereof A synthetic resin emulsion comprising a resin component can be used. The component (a) can be obtained by a known polymerization method such as an emulsion polymerization method using water as a medium. These components (a) may have crosslinking reactivity. Moreover, the form of (a) component is not specifically limited, Either 1 liquid type and 2 liquid type may be sufficient.

  The minimum film-forming temperature of the component (a) can be appropriately set. If the minimum film-forming temperature of the component (a) is set to 5 ° C. or lower, and further 0 ° C. or lower, the amount of film-forming aids and the like can be reduced, and low VOC (low volatility suitable for interior finishing Organic compound) paint can be obtained.

The component (b) in the composition of the present invention is an organosiloxane compound (b) having an amino group (hereinafter referred to as “component (b)”). In this invention, it becomes possible to exhibit the outstanding antibacterial performance by including (b) component as an essential component.
The reason why such an effect can be obtained is not clear, but the component (b) has the ability to collect fungi, and the amino group (b) has the property of easily binding to silver ions. It is presumed that this is contributing. Furthermore, in the composition of the present invention using water as a medium, the component (b) is easily oriented on the coating film surface, and the component (b) and silver ions are rich on the coating film surface and trapped on the coating film surface. It is considered that an effective antibacterial action can be obtained by a cycle in which the antibacterial action is exerted on the fungus thus obtained.

  The component (b) in the composition of the present invention usually has units represented by the following formulas (1) and (2).

（式中、Ｒ^１は同一または異なって、アルキル基、アリール基、アラルキル基を示し、Ｒ^２はアルキレン基、オキシアルキレン基を示す。Ｘはアミノ基示す。ｍ，ｎは１以上の整数である。）

Wherein R ¹ is the same or different and represents an alkyl group, an aryl group or an aralkyl group, R ² represents an alkylene group or an oxyalkylene group, X represents an amino group, and m and n are integers of 1 or more. is there.)

As the amino group of the component (b), for example, —NH ₂ , —NHCH ₃ , —N (CH ₃ ) ₂ , —NH (CH ₂ ) ₂ NH ₂ , —NH (CH ₂ ) ₂ NHCH ₃ , —NH ( CH ₂ ) ₂ N (CH ₃ ) _{2 and the} like.

  The form of (b) component will not be restrict | limited especially if it is the form disperse | distributed in water, Any of the forced emulsification type emulsion using surfactant or a self-emulsification type emulsion may be sufficient.

  The mixing ratio of the component (b) is usually 1 to 100 parts by weight, preferably 2 to 50 parts by weight, more preferably 3 to 30 parts by weight in terms of the solid content with respect to 100 parts by weight of the solid content of the component (a). is there. When the component (b) is less than 1 part by weight, a sufficient effect cannot be obtained in antibacterial performance. (B) When there are more components than 100 weight part, there exists a possibility that the stain resistance of a coating film etc. may fall.

In the composition of the present invention, a silver antibacterial agent (c) (hereinafter referred to as “component (c)”) is used in combination with the component (b) described above. Examples of such component (c) include organic or inorganic silver compounds, compounds in which silver compounds are supported on base particles, and the like, and commercially available products can also be used.
As the component (c), a silver ion state and a metal silver state are widely known. In general, the former exhibits antibacterial properties by reacting with bacterial cell membranes or proteins in the cells, and the latter is considered to exhibit antibacterial properties by reactive oxygen species generated by the excitation of silver by light. Among these, as the component (c) in the present invention, the former silver-based antibacterial agent having silver ions is suitable. Such silver ions may be in a complex state.

The component (c) in the present invention is particularly preferably an inorganic compound carrying silver ions. Examples of the inorganic compound that supports silver ions include activated carbon, activated alumina, silica gel, zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, hydrous bismuth, hydrous zirconium, hydrotalcite, and the like. Of these, zeolite is particularly preferred.
As a method for supporting silver ions on these inorganic compounds, a known method may be used. For example, a method of supporting by physical adsorption or chemical adsorption, a method of supporting by ion exchange reaction, a method of supporting by a binder, a silver compound Examples thereof include a method of supporting by injecting into an inorganic compound, a method of supporting by forming a thin layer of a silver compound on the surface of the inorganic compound by a thin film forming method such as vapor deposition, dissolution precipitation reaction, and sputtering. The particle size of such a silver-based antibacterial agent is usually about 0.01 to 10 μm.

  The mixing ratio of the component (c) is usually 0.01 to 5 parts by weight, preferably 0.02 to 3 parts by weight, and more preferably 0.02 to 3 parts by weight in terms of the solid content with respect to 100 parts by weight of the solid content of the component (a). 05 to 1 part by weight. When the component (c) is less than 0.01 part by weight, a sufficient effect cannot be obtained in antibacterial performance. When the amount of the component (c) is more than 5 parts by weight, discoloration due to oxidation-reduction reaction or the like may occur. It is also disadvantageous in terms of cost.

The composition of the present invention preferably contains a nitrogen-containing ring compound in addition to the above-described components. By including such a nitrogen-containing ring compound, not only the antibacterial spectrum but also the antibacterial activity can be enhanced synergistically.
Examples of the nitrogen-containing ring compound include triazine compounds, thiazole compounds, isothiazole compounds, and imidazole compounds. However, among these nitrogen-containing ring compounds, those containing a chlorine atom in the molecule may cause discoloration of the paint, and therefore should be avoided.
The mixing ratio of the nitrogen-containing ring compound is usually 0.01 to 5 parts by weight, preferably 0.02 to 3 parts by weight, and more preferably 0. 05 to 1 part by weight.

  In addition to the above-described components, the composition of the present invention is a coloring pigment, extender pigment, aggregate, fiber, film-forming aid, plasticizer, antifreezing agent, antiseptic, antifungal agent, antifoaming agent, thickener, Contains leveling agents, pigment dispersants, anti-settling agents, anti-sagging agents, matting agents, UV absorbers, light stabilizers, antioxidants, adsorbents, photocatalysts, etc. to the extent that they do not impair the effects of the present invention. You can also. The composition of the present invention can be produced by uniformly mixing these components by a conventional method.

The composition of the present invention can be used for new construction work, renovation work, etc., and can be applied to building interior surfaces such as ceilings and wall surfaces. In particular, it is suitable in a bathroom, bathroom, toilet and the like.
The base material used for the interior surface of the building is not particularly limited as long as it is used as a general building material. For example, gypsum board, calcium silicate board, slate board, extrusion board, tile, plywood , Metal plate, plastic plate, concrete, mortar and the like.
The interior coating composition of the present invention can be applied directly to such a substrate, or after being subjected to some surface treatment (such as a base treatment with a sealer, surfacer, filler, putty, etc.). It is also possible.

As a coating method, it can be applied by various methods such as brush coating, trowel coating, spray coating, and roller coating. Further, it can be pre-coated using a roll coater, a flow coater or the like. The application amount is not particularly limited, but is usually about 0.1 to 1 kg / m ² . Moreover, the composition of this invention can also be diluted with water at the time of coating. The dilution ratio is usually about 0 to 50% by weight.

  Examples are given below to clarify the features of the present invention. In the examples, paints were produced using the following raw materials.

・ Synthetic resin emulsion (acrylic resin emulsion, solid content 50% by weight, minimum film-forming temperature 0 ° C.)
Coloring pigment: Titanium oxide (average particle size 0.3 μm)
・ External pigment: heavy calcium carbonate (average particle size 8μm)
・ Dispersant: Polycarboxylic acid-based dispersant ・ Thickener: Associative polymer-based thickener ・ Antifoaming agent: Silicone-based antifoaming agent ・ Organosiloxane compound: Emulsified dispersion of amino group-containing dimethylsiloxane compound (solid content) 55% by weight)
Silver-based antibacterial agent: aqueous slurry of silver ion-carrying zeolite (active ingredient 20% by weight, average particle size 3 μm)
Nitrogen-containing ring compound: isothiazoline-based compound (active ingredient 4% by weight)

(Test 1)
For 200 parts by weight of the synthetic resin emulsion, 130 parts by weight of color pigment, 100 parts by weight of extender pigment, 5 parts by weight of dispersant, 5 parts by weight of thickener, 2 parts by weight of antifoaming agent and 66 parts by weight of organosiloxane compound are used in a conventional manner. To prepare a sample A.
Sample B was prepared by mixing 33 parts by weight of the organosiloxane compound in the formulation of Sample A.
Sample C was prepared by removing the organosiloxane compound in the formulation of Sample A.

A 300 mm x 224 mm x 3 mm flexible board is spray-coated with an epoxy-based aqueous sealer at a coating amount of 0.15 kg / m ² and dried in the standard state (temperature 23 ° C, relative humidity 50%) for 4 hours. The test piece was spray-coated at a coating amount of 0.25 kg / m ² and cured for 7 days in a standard state. The test piece obtained by the above method was irradiated with a germicidal lamp for 1 minute, and then the exposure test was started by standing the test piece against the wall surface in the toilet. After 3 months of exposure, Petan Check 25 Sabouraud Agar (manufactured by Eiken Kikai Co., Ltd.) was pressed against the surface of the coating and cultured in a 37 ° C. atmosphere to detect fungi. Evaluation was based on the ratio of colonies occupying the surface of the medium, and was evaluated in five stages (5: not detected, 4: 1-20% of the medium, 3: 20-60% of the medium, 2: 60-80% of the medium, 1 : 80-100% of the medium).
As a result, the sample A was “1”, the sample B was “2”, and the sample C was “3”. As the amount of the organosiloxane compound mixed increased, more fungi were detected.

Example 1
A paint was prepared by further blending 1 part by weight of the silver antibacterial agent and 0.5 part by weight of the nitrogen-containing ring compound with the sample A (Table 1). Each test was implemented by the following methods about the obtained coating material.

1. Exposure test A 300 mm x 224 mm x 3 mm flexible board is spray-coated with an epoxy-based aqueous sealer at a coating amount of 0.15 kg / m ² , dried in standard conditions (temperature 23 ° C, relative humidity 50%) for 4 hours, and then painted. A test piece was prepared by spray coating at a coating amount of 0.25 kg / m ² and curing for 7 days in a standard state. The test piece obtained by the above method was irradiated with a germicidal lamp for 1 minute, and then the exposure test was started by standing the test piece against the wall surface in the toilet. At the time when 1 month of exposure and 3 months of exposure passed, Petan Check 25 Sabouraud Agar (manufactured by Eiken Kikai Co., Ltd.) was pressed against the surface of the coating film and cultured in an atmosphere of 37 ° C. to detect fungi. Evaluation was based on the ratio of colonies occupying the surface of the medium, and was evaluated in five stages (5: not detected, 4: 1-20% of the medium, 3: 20-60% of the medium, 2: 60-80% of the medium, 1 : 80-100% of the medium).

2. Antibacterial test A test piece was prepared by spray-coating a 50 mm × 50 mm × 1 mm aluminum plate at a coating amount of 0.25 kg / m ² and curing for 7 days in a standard state. About the obtained test piece, the antibacterial test was implemented based on JISZ2801 (2000), and the antibacterial activity was computed. In this antibacterial test, the paint (sample B) of Comparative Example 1 was used as a blank.

  The test results are shown in Table 2. In Example 1, excellent results could be obtained in any test.

( Reference Example 1 )
A paint was prepared according to the formulation shown in Table 1. This formulation is a mixture of the sample A and 1 part by weight of a silver antibacterial agent. The test similar to Example 1 was implemented about the obtained coating material. The results are shown in Table 2.

(Comparative Example 1)
A paint was prepared according to the formulation shown in Table 1. This formulation is the same as Sample B. The test similar to Example 1 was implemented about the obtained coating material. The results are shown in Table 2.

(Comparative Examples 2 to 4)
A paint was prepared according to the formulation shown in Table 1. The test similar to Example 1 was implemented about the obtained coating material. The results are shown in Table 2.

Claims (1)

Synthetic resin emulsion (a) (excluding the following (b)),
An organosiloxane compound (b) having an amino group containing a unit represented by the following formula (1) or (2);
A silver antibacterial agent (c), and a nitrogen-containing ring compound (d) containing an isothiazoline compound ,
1 to 100 parts by weight of the organosiloxane compound (b), 0.01 to 5 parts by weight of the silver-based antibacterial agent (c), and a nitrogen-containing ring with respect to 100 parts by weight of the solid content of the synthetic resin emulsion (a) A water-based coating composition comprising 0.01 to 5 parts by weight of the compound (d).

(In the formula, R ¹ is the same or different and represents an alkyl group, an aryl group, or an aralkyl group, R ² represents an alkylene group , X represents an amino group, and m and n are integers of 1 or more.)