JP2011207924A - Antifouling coating and product coated therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily improve both antifouling properties based on water deposits and antifouling properties based on oil contents in sanitary ware etc. in contact with water including soluble silica and also oil contents.SOLUTION: The antifouling coating is coated on a substrate having a hydroxyl group on the surface thereof and exhibits antifouling properties based on water deposits and antifouling properties based on oil contents. The antifouling coating includes a fluorine-based silane coupling agent, a non-aqueous solvent, and a surfactant which reduces surface tension of a gas-liquid interface.

Description

  The present invention relates to an antifouling paint and a product to which the antifouling paint is applied.

  Conventionally, the antifouling paint disclosed in Patent Document 1 is known. This antifouling paint is a mixture of the first agent and the second agent. As the first agent, a perfluoroalkyl group-containing organosilicon compound and a hydrolyzable group-containing methylpolysiloxane compound are prepared, and these are co-polymerized in a hydrophilic solvent composed of 0.1N hydrochloric acid water, t-butanol and hexane. It has been hydrolyzed. The second agent is a mixture of organopolysiloxane and methanesulfonic acid as a strong acid.

  This antifouling paint is considered to be constituted as an addition compound or a kind of polymer in which a plurality of molecules are intertwined in a complicated manner. If this antifouling paint is applied to a substrate having a hydroxyl group (OH group) on its surface, such as a glaze layer of sanitary ware or the surface of a glass product, it becomes an antifouling layer by drying. The antifouling layer binds to hydroxyl groups present on the surface of the base material and shields the hydroxyl groups to disable them. For this reason, even if the product thus obtained comes into contact with water containing soluble silica, it is possible to prevent the soluble silica from adhering to the hydroxyl groups, and it is possible to prevent adhesion of water due to the soluble silica. It is possible to effectively prevent dirt components from accumulating in water.

Japanese Patent No. 4226136

  However, according to the test results of the inventors, in the conventional antifouling paint, the oil component is easily adapted to the antifouling layer. For this reason, for example, if the sanitary ware is a flush toilet, on the surface of the flush toilet, the oil in the stool may become familiar with the antifouling layer, and dirt components may accumulate in the oil. The same applies to glass products that come into contact with water as well as water containing soluble silica. For this reason, in these sanitary ware etc., the further antifouling property improvement is desired.

  The present invention has been made in view of the above-described conventional situation, and in sanitary ware that comes into contact with oil together with water containing soluble silica, both antifouling properties based on water stains and antifouling properties based on oil are provided. Making it easier to improve is an issue to be solved.

The antifouling paint of the present invention is applied to a substrate having a hydroxyl group on the surface, and in an antifouling paint that exhibits antifouling properties based on water stain and antifouling properties based on oil,
It contains a fluorine-based silane coupling agent, a non-aqueous solvent, and a surfactant that lowers the surface tension of the gas-liquid interface (claim 1).

  If the antifouling paint of the present invention is also applied to a substrate, it becomes an antifouling layer by drying. According to the tests by the inventors, this antifouling layer also binds to hydroxyl groups present on the surface of the substrate, and the hydroxyl groups are shielded to be disabled. In addition, this antifouling layer is difficult to blend with oil.

  In particular, this antifouling paint contains a surfactant that lowers the surface tension of the gas-liquid interface, together with a fluorine-based silane coupling agent and a non-aqueous solvent, thus improving wettability and improving reaction efficiency. is doing. That is, the antifouling layer made of this antifouling paint has a larger contact angle than that containing no surfactant. Further, the antifouling layer made of this antifouling paint has a smaller variation in contact angle than that containing no surfactant. For this reason, according to this antifouling paint, it is possible to more reliably prevent adhesion of water stains or the like to a specific part of the product.

  Japanese Patent Laid-Open No. 2003-183581 discloses a water-soluble antifouling paint obtained by blending a silane coupling agent with deionized water. This publication discloses that when this water-soluble antifouling paint is applied to the surface of a substrate such as a tile, a surfactant may be added if it is easy to repel and difficult to apply evenly. JP 2005-510607 A discloses a water-soluble antifouling paint which is a concentrate containing a fluorinated alkoxysilane, an organic co-solvent and a fluorinated surfactant, and is diluted with water or an aqueous solvent mixture. Yes.

  However, these antifouling paints are different in the action of the surfactant from the antifouling paints of the present invention in which the solvent is aqueous and the solvent is non-aqueous. The present invention is also characterized in that the antifouling paint whose solvent is non-aqueous contains a surfactant.

  That is, as shown in FIG. 1, in the antifouling paint 2 in which the solvent 1 is non-aqueous, the reactive group of the silane coupling agent 3 is only a part of the alkoxy group (OR group) due to contact with moisture in the atmosphere. Is hydrolyzed to a hydroxyl group (OH group). When this antifouling paint 2 does not contain a surfactant and is directly applied to the substrate 4, as shown in FIG. 2, the alkoxy group of the silane coupling agent 3 reacts with the hydroxyl group on the surface of the substrate 4, A hydrophobic antifouling layer is formed on the surface. However, when the antifouling layer is formed in spots, it becomes difficult to maintain affinity with the non-aqueous solvent 1, and the other silane coupling agent 3 becomes difficult to react with the hydroxyl group of the substrate 4.

  As shown in FIG. 3, the antifouling paint 5 of the present invention includes a surfactant 6 that lowers the surface tension of the gas-liquid interface for that purpose. In this case, since the surface tension at the interface between the antifouling paint 5 and the air is lowered, the wettability of the base material 4 is improved over a long period from the initial stage when the antifouling paint 5 is applied to the base material 4. For this reason, as shown in FIG. 4, the silane coupling agent 3 can react with the hydroxyl group of the substrate 4 for a long period of time. That is, a hydrophobic antifouling layer is formed on the surface of the base material 4, and even when the antifouling layer is formed in spots, the alkoxy group and the hydroxyl group on the surface can remain for a long period of time, and finally the homogeneous layer An antifouling layer can be formed.

  On the other hand, as shown in FIG. 5, in the antifouling paint 8 in which the solvent 7 is water-based, most of the reactive groups of the silane coupling agent 3 are hydrolyzed to hydroxyl groups due to the presence of a large amount of water. ing. When this antifouling paint 8 does not contain a surfactant and is applied to the substrate 4 as it is, the silane coupling agent 3 is a substrate similar to the self-condensation of the silane coupling agents 3 as shown in FIG. It reacts only with the hydroxyl group on the surface of 4, and it is difficult to form only a speckled hydrophobic layer on the surface.

  As shown in FIG. 7, the antifouling paint 10 including the surfactant 9 has no effect of retaining the alkoxy groups and the hydroxyl groups on the surface of the substrate 4 for a long period of time, and only forms a sparse hydrophobic layer on the surface. It is hard to be done. Further, in the antifouling paint 10 in which the solvent 7 is water-based, the reactive group of the silane coupling agent 3 is almost a hydroxyl group. For this reason, when this antifouling paint 10 is applied to the base material 4, as shown in FIG. 8, the silane coupling agent 3 is a hydroxyl group on the surface of the base material 4 as in the self-condensation of the silane coupling agents 3. It is difficult to form only a hydrophobic layer with a spot on the surface.

  Therefore, according to the antifouling paint of the present invention, it is possible to easily improve both the antifouling property based on water and the antifouling property based on oil in a base material that comes into contact with oil together with water containing soluble silica. It is.

  As the base material, it is possible to employ sanitary ware such as flush toilets and washbasins, tiles, and glass products, as well as metals having an oxide film formed on the surface.

  According to the inventors' tests, the surfactant is preferably a nonionic surfactant. This is because anionic surfactants are hardly soluble in non-aqueous solvents, and fluorinated silane coupling agents are polymerized with cationic surfactants.

  Further, according to the tests by the inventors, it is preferable that the fluorine-based silane coupling agent is perfluoropolyether (PFPE) and the surfactant is a fluorine-based oligomer or polymer (Claim 2).

  As the perfluoropolyether, for example, those having the following chemical formulas disclosed in JP-A-11-29585 can be adopted.

The solvent can have an alkane and an alcohol. As the alkane, various types can be adopted as long as they are a chain or cyclic saturated hydrocarbon represented by the general formula C _n H _{2n + 2} . For example, when paraffin is employed as the alkane, normal paraffin, isoparaffin and / or cycloparaffin can be employed. According to the test results of the inventors, the alkane is preferably isoparaffin.

  Any alcohol can be used as long as it is a substance in which a hydrogen atom of a hydrocarbon is replaced with a hydroxy group. For example, when butanol is employed as the alcohol, 1-butanol (n-butanol), 2-methyl-1-propanol (isobutanol), 2-butanol (sec-butanol), 2-methyl-2-propanol (tert- Butanol (t-butanol)) and the like can be employed. According to the test results of the inventors, the alcohol is preferably t-butanol. Moreover, according to the test results of the inventors, it is also preferable to employ ethanol as the alcohol. In this case, according to the test results of the inventors, it is possible to realize a reduction in manufacturing cost without causing much deterioration in quality.

  According to the tests by the inventors, it is also preferable that the fluorinated silane coupling agent is perfluoropolyether (PFPE) and the surfactant is an acrylic oligomer or polymer (Claim 3).

  Inclusion of acrylic oligomers or polymers increases the contact angle. The acrylic polymer may be a fluorine-containing acrylic polymer or a non-fluorinated acrylic polymer.

  According to the test results of the inventors, a fluorine-containing acrylic polymer is preferred (claim 4). If a fluorine-containing acrylic polymer is employed, the effect of increasing the contact angle can be obtained over a wider range than when a non-fluorinated acrylic polymer is employed, and the management of the antifouling paint becomes easy.

  According to the test results of the inventors, the fluorine-containing acrylic polymer is preferably 0.5 to 50 ppm in the whole (claim 5). If the fluorine-containing acrylic polymer is less than 0.5 ppm in the whole, the effect of increasing the contact angle is small, and if the fluorine-containing acrylic polymer exceeds 50 ppm in the whole, the contact angle is decreased.

  The antifouling paint of the present invention comprises a first agent comprising a perfluoropolyether and a solvent, and a second agent comprising a fluorine-containing acrylic polymer and a solvent, and the first agent before being applied to the substrate. It is preferable that the second agent is mixed (claim 6). According to the inventors' tests, the first agent is stable due to its low water content, and can be stored for a long time. Therefore, if the first agent and the second agent are stored before application, and the first agent and the second agent are mixed and applied to the base material as an antifouling paint immediately before application, A stable product can be easily manufactured. In this sense, the first agent is preferably prepared not in the atmosphere but in an inert gas such as dry nitrogen gas. If a surfactant is previously added to the second agent, the surfactant can be uniformly dispersed in the two liquids before the reaction starts.

  The first agent preferably has a fluorine-based solvent (claim 7). According to the test results of the inventors, if the solvent has a fluorinated solvent, a uniform and stable antifouling paint can be obtained. Hydrofluoroether etc. are employable as a fluorine-type solvent.

  The second agent preferably contains a catalyst that promotes hydrolysis of the fluorinated silane coupling agent. In particular, hydrochloric acid, methanesulfonic acid, acetic acid, trifluoroacetic acid and the like act as a catalyst for the antifouling paint. According to the test results of the inventors, if hydrochloric acid is used as the catalyst, the reactivity and workability of the antifouling paint of the present invention are excellent. By adding hydrochloric acid to the second agent different from the first agent, the long-term storage stability of the first agent can be ensured. According to the test results of the inventors, the antifouling paint preferably contains hydrochloric acid at a concentration of 0.01 to 20.0 g / L.

  The product of the present invention is capable of coming into contact with water and oil containing soluble silica, has a base material having a hydroxyl group on the surface, and the antifouling paint is applied to the surface of the base material (claim) Item 8). Since this product does not cause water stains over a long period of time and is resistant to oil stains, it can maintain its aesthetics for a long period of time.

It is a schematic structural diagram of the surface of a base material and the antifouling paint whose solvent is non-aqueous and does not contain a surfactant. It is a schematic structural diagram showing a state in which a solvent is non-aqueous and an antifouling paint containing no surfactant is applied to a substrate. It is a schematic structural diagram of the surface of a base material and the antifouling coating material whose solvent is non-aqueous and contains surfactant. It is a schematic structural diagram showing a state in which a solvent is non-aqueous and an antifouling paint containing a surfactant is applied to a substrate. It is a schematic structure diagram of the surface of a base material and an antifouling paint whose solvent is aqueous and does not contain a surfactant. It is a schematic structural diagram showing a state in which a solvent is water-based and an antifouling paint not containing a surfactant is applied to a substrate. It is a schematic structure diagram of the surface of the base material and the antifouling paint containing a surfactant whose solvent is aqueous. FIG. 3 is a schematic structural diagram showing a state in which a solvent is aqueous and an antifouling paint containing a surfactant is applied to a substrate.

  Hereinafter, the present invention will be specifically described by tests 1 and 2.

(Test 1)
In Test 1, the effect was compared between the antifouling paint of the example containing the surfactant and the antifouling paint of the comparative example not containing the surfactant.

  First, a fluorine-based silane coupling agent (“X-71-107B (3)” manufactured by Shin-Etsu Chemical Co., Ltd.) is prepared. This silane coupling agent has perfluoropolyether (PFPE) as the main chain and has a concentration of 3%. Further, as non-aqueous solvents, isoparaffin (“Isopar L” manufactured by ExxonMobil Co., Ltd.), t-butanol (manufactured by Wako Pure Chemical Industries, Ltd.), and fluorine-based solvent (hydrofluoroether “3M Co., Ltd.”) HRE-7200 "). Isopar L has an average molecular weight of 162 (g / mol), a density of 0.768 (g / ml), a viscosity measured at 25 ° C of 1.64 (mm2 / sec), and is estimated at 20 ° C. The vapor pressure is 0.069 (KPa). Further, a fluorine-containing acrylic polymer (“Polyflow KL-600” manufactured by Kyoeisha Chemical Co., Ltd.) is prepared as a surfactant. The fluorine-containing acrylic polymer is a 30% solution using 3-methoxy-3-methyl blue as a solvent. Further, concentrated hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is also prepared as a catalyst.

(Example)
A fluorine-based silane coupling agent, isoparaffin, t-butanol and a fluorine-based solvent were mixed in the ratio shown in Table 1 to obtain a first agent. Further, a fluorine-containing acrylic polymer, isoparaffin, t-butanol and concentrated hydrochloric acid were mixed at a ratio shown in Table 2 to obtain a second agent.

  And the 1st agent and the 2nd agent were mixed by the volume ratio 1: 1, and it was set as the antifouling paint of the Example. A 10 cm square tile was prepared as a base material, and the cloth on which the antifouling paint was dropped was rubbed against the glass layer of the base material for 10 seconds to obtain a sample of the example.

(Comparative example)
A fluorine-based silane coupling agent, isoparaffin, t-butanol and a fluorine-based solvent were mixed at a ratio shown in Table 1 to obtain a first agent. Further, except for the fluorine-containing acrylic polymer, isoparaffin, t-butanol and concentrated hydrochloric acid were mixed at a ratio shown in Table 2 to obtain a second agent.

  And the 1st agent and the 2nd agent were mixed by the volume ratio 1: 1, and it was set as the antifouling paint of the comparative example. The cloth on which the antifouling paint was dropped was rubbed against the glass layer of the substrate for 10 seconds to obtain a sample of a comparative example.

  The water contact angle (°) and the standard deviation, and the oil contact angle (°) and the standard deviation were measured for the samples of Examples and Comparative Examples that were placed one day after the preparation to stabilize the reaction. The results are shown in Table 3.

  Moreover, about the sample of the Example and the comparative example, it slid 10,000 times using the load of 1.7 kg using a commercially available sponge, and measured the water contact angle (degree) before and behind a deterioration test. The results are shown in Table 4.

  From Tables 3-4, it turns out that the antifouling layer obtained by the antifouling paint of an Example and a comparative example has improved both the antifouling property based on water red and the antifouling property based on oil. This is because the antifouling layer shields the hydroxyl groups present on the surface of the base material to make it impossible, and it is difficult for the antifouling layer to be familiar with oil.

  In particular, the antifouling paint of the example has a larger water contact angle and oil contact angle than the antifouling paint of the comparative example. Moreover, the antifouling layer by the antifouling paint of an Example has the variation in a water contact angle and an oil contact angle smaller than the antifouling layer by the antifouling paint of a comparative example. This is because the antifouling paint of the example contains a fluorine-containing acrylic polymer, so that wettability is improved and reaction efficiency is improved.

  It can be seen that the antifouling paints of the examples were able to finally form a homogeneous antifouling layer because the obtained antifouling layer had small variations in water contact angle and oil contact angle. This is because the antifouling paint of the example employs a non-aqueous solvent and contains a surfactant, so that the alkoxy group of the silane coupling agent and the surface hydroxyl group remain for a long period of time.

  Therefore, according to the antifouling paint of the example, it can be seen that adhesion of water stains or the like to a specific part of the product can be more reliably prevented.

  Moreover, since the antifouling paint of an Example is what mixed the 1st agent and the 2nd agent before apply | coating to a base material, the product with stable quality can be manufactured easily.

(Test 2)
In Test 2, the effect was compared between the case where a fluorine-containing acrylic polymer was employed and the case where a non-fluorine acrylic polymer was employed. As the non-fluorinated acrylic polymer, (Polyflow KL-800, manufactured by Kyoeisha Chemical Co., Ltd.) was used. The non-fluorinated acrylic polymer is a 93% solution using water as a solvent.

  The ratio of the fluorine-containing acrylic polymer in the antifouling paint was changed in the range of 0.0 to 5000.0 (ppm), and the water contact angle (°) and the standard deviation were determined. The ratio of other chemicals is the same as in Example 1. The results are shown in Table 5.

  Moreover, the ratio of the non-fluorine acrylic polymer in the antifouling coating was also changed in the range of 0.0 to 5000.0 (ppm), and the water contact angle (°) and the standard deviation were determined. The ratio of other chemicals is the same as in Example 1. The results are shown in Table 6.

  Tables 5 and 6 show that the contact angle increases when the antifouling paint contains a fluorine-containing acrylic polymer or a non-fluorine acrylic polymer.

  It can also be seen that the use of a fluorine-containing acrylic polymer can provide an effect of increasing the contact angle in a wide range of content compared to the case of using a non-fluorine acrylic polymer. For this reason, it is preferable to employ a fluorine-containing acrylic polymer in terms of facilitating the management of the antifouling paint. Furthermore, it turns out that it is preferable that a fluorine-containing acrylic polymer is 0.5-50 ppm in the whole.

  Moreover, the effect was confirmed in the case where a fluorine-containing acrylic polymer is employed as the surfactant and in the case where a fluorine-containing non-acrylic polymer is employed. As the fluorine-containing non-acrylic polymer, “Megafac F-444” manufactured by Dainippon Ink & Chemicals, Inc. was used.

  The ratio of the fluorine-containing non-acrylic polymer in the antifouling coating was changed in the range of 0.0 to 500.0 (ppm), and the water contact angle (°) and standard deviation were determined. The ratio of other chemicals is the same as in Example 1. The results are shown in Table 7.

  Table 7 shows that a fluorine-containing non-acrylic polymer is effective, but a fluorine-containing acrylic polymer is preferable. In particular, it can be seen that the fluorine-containing acrylic polymer is preferably 0.5 to 50 ppm in the whole.

  In the above, the present invention has been described with reference to Tests 1 and 2. However, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be appropriately modified and applied without departing from the spirit thereof. .

  The present invention can be used for sanitary ware such as flush toilets and washbasins, tiles, glass products, metal products, and the like.

Claims (8)

In antifouling paints that are applied to a substrate having a hydroxyl group on the surface and exhibit antifouling properties based on water and oil and antifouling properties based on oil
An antifouling paint comprising a fluorine-based silane coupling agent, a non-aqueous solvent, and a surfactant that lowers the surface tension of a gas-liquid interface.   The antifouling paint according to claim 1, wherein the fluorine-based silane coupling agent is perfluoropolyether, and the surfactant is a fluorine-based oligomer or polymer.   The antifouling paint according to claim 1, wherein the fluorine-based silane coupling agent is a perfluoropolyether and the surfactant is an acrylic polymer.   The antifouling paint according to claim 2 or 3, wherein the surfactant is a fluorine-containing acrylic polymer.   The antifouling paint according to claim 4, wherein the fluorine-containing acrylic polymer is 0.5 to 50 ppm in the whole.   The first agent comprising the perfluoropolyether and the solvent, and the second agent comprising the fluorine-containing acrylic polymer and the solvent, and before being applied to the substrate, the first agent and the first agent The antifouling paint according to claim 1, wherein two agents are mixed.   The antifouling paint according to claim 6, wherein the first agent has a fluorinated solvent.   It has contact with water and oil containing soluble silica and has a substrate having a hydroxyl group on the surface, and the antifouling paint according to any one of claims 1 to 7 is applied to the surface of the substrate. Product characterized by.

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