Water-resistant protective agents, primers, painting methods for water-resistant fixtures, and repainting methods.

Abstract

To provide a water protective agent capable of suppressing adhesion of dirt generated at water installations such as a bath room, a kitchen, a washroom and a toilet.SOLUTION: A water protective agent contains a mixture of a silicone resin expressed with a formula (R1SiO3 / 2) as a hard bonding structural unit that crosslinks three-dimensionally, and a silicone resin expressed with a formula (R22SiO2 / 2) as a soft bonding structural unit that crosslinks two-dimensionally. Since a surface of a protective film 30 formed from the water protective agent is coated with water-repellent alkyl silanes of R1Si and R2Si, it is possible to suppress the adhesion of dirt to a water installation 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technical field of this specification relates to water-resistant protective agents, primers, painting methods for water-resistant facilities, and repainting methods for water-resistant facilities that suppress the adhesion of dirt in water-resistant areas such as bathrooms, kitchens, washrooms, and toilets, which are water-using facilities in buildings. [Background technology]

[0002] Water-using facilities in a building include bathrooms, kitchens, washrooms, and toilets. Various types of dirt accumulate in these areas. Patent Document 1 describes a water-related protective agent containing photocatalytic powder that facilitates the cleaning of dirt adhering to these areas. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-132790 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the water-related protective agent described in Patent Document 1 works by decomposing attached organic matter with photocatalytic powder, and then washing away the decomposed organic matter with water. For this reason, there has been a long-standing demand for a method that suppresses the adhesion of dirt, including organic matter, to water-related areas.

[0005] The problem that the technology described herein aims to solve has been addressed in view of the above-mentioned points, and aims to provide a water-resistant protective agent that can suppress the adhesion of dirt in water-related areas such as bathrooms, kitchens, washrooms, and toilets. [Means for solving the problem]

[0006] The water surrounding protection agent according to the embodiment of this specification is a water surrounding protection agent that suppresses the adhesion of dirt generated in the water surrounding areas such as bathrooms, kitchens, washrooms, toilets, etc., and a mixture of a silicone resin represented by the formula (R 1 SiO 3 / 2 ) in the binding structural unit and a silicone resin represented by the formula (R 2 2SiO 2 / 2 ) in the binding structural unit is 30 - 75% by mass, an alkoxysilane represented by the formula ((R[[ID=ID=11]] 3 O)3SiY 3 ) in the binding structural unit is 10 - 30% by mass, and an alkoxysilane represented by the formula ((R 4 O)2SiCH3Y 4 ) in the binding structural unit is 10 - 30% by mass, and is characterized by containing these.

[0007] According to the water surrounding protection agent according to the embodiment of this specification, a mixture of a silicone resin represented by the formula (R 1 SiO 3 / 2 ) (hereinafter sometimes referred to as "T-unit silicone resin") having a hard binding structural unit crosslinked three-dimensionally and a silicone resin represented by the formula (R 2 2SiO 2 / 2 ) (hereinafter sometimes referred to as "D-unit silicone resin") having a soft binding structural unit crosslinked two-dimensionally is contained as a main component. Therefore, the protective film formed from the water surrounding protection agent according to the embodiment forms a hard protective film having flexibility mainly with the hard three-dimensional crosslinking of the T-unit silicone resin and added with the two-dimensional crosslinking of the D-unit silicone resin. The surface of this film is coated with an alkylsilane of R 1 Si and R 2 Si, so that the adhesion of dirt can be suppressed. Further, the water surrounding protection agent according to the embodiment has an alkoxysilane represented by the formula ((R 3 O)3SiY 3 ) (hereinafter sometimes referred to as "T-unit alkoxysilane") in the binding structural unit and an alkoxysilane represented by the formula ((R 4 O)2SiCH3Y 4Because it contains an alkoxysilane represented by (hereinafter sometimes referred to as "D-unit alkoxysilane"), the T-unit alkoxysilane crosslinks with the silicone resin and adheres to the substrate three-dimensionally, while the D-unit alkoxysilane crosslinks with the silicone resin and adheres linearly (two-dimensionally) to the substrate. In other words, the water-resistant protective agent according to this embodiment adheres to the substrate in a conforming manner, forms a durable protective film, and its surface is coated with alkylsilane, thus suppressing the adhesion of dirt.

[0008] Furthermore, the above-mentioned water-resistant protective agent is a primer, The bond structure unit is given by formula (SiO 4 / 2 5-20% by mass of silicone represented by ) and the bonding structure unit is given by formula ((R 6 O)3SiR 7 The solution may contain 5 to 20% by mass of an alkylalkoxysilane represented by ) and 60 to 85% by mass of a diluent.

[0009] According to this, because the primer is diluted with a diluent, it can penetrate into the fine irregularities on the surface of the substrate, and the bonding structure units that penetrate into these fine irregularities are formed by the formula (SiO 4 / 2 The silicone represented by ((R) below (hereinafter sometimes referred to as "Q unit silicone") adheres firmly to the substrate by the anchoring effect. The primer film formed from the primer has a bonding structure unit of formula ((R 6 O)3SiR 7 By containing alkylalkoxysilanes represented by (hereinafter sometimes referred to as "T-unit alkylalkoxysilanes"), the product has flexibility and can adhere firmly and conformably to the substrate. Furthermore, when the water-resistant protective agent is applied to the primer film formed from the primer, the protective film formed from the water-resistant protective agent can adhere firmly and conformably to the primer film because the T-unit silicone resin, D-unit silicone resin, T-unit alkoxysilane, and D-unit alkoxysilane contained in the water-resistant protective agent crosslink with the Q-unit silicone and T-unit alkylalkoxysilane of the primer film.

[0010] Here, the painting method for plumbing fixtures according to the embodiment is: The invention comprises a primer coating step of applying the above-mentioned primer to plumbing fixtures to form a primer film, and a protective coating step of applying the above-mentioned plumbing protective agent to the primer film to form a protective film, characterized in that a multi-layer protective layer is formed consisting of the primer film and the protective film.

[0011] According to this, the primer forms a primer film that adheres firmly and conforms to the plumbing fixtures, and the plumbing protective agent adheres firmly and conforms to the primer film. The multi-layer protective layer, consisting of the primer film and the protective film, has a surface that is R 1 Si and R 2 It is coated with an alkylsilane of Si, which can suppress the adhesion of dirt.

[0012] Furthermore, a method for repainting plumbing fixtures equipped with a multi-layer protective layer is a method for repainting the multi-layer protective layer formed by the above-described method for painting plumbing fixtures, A cleaning process using an alkaline cleaning agent, A protective agent recoating step is performed after the cleaning step, in which the above-mentioned water-resistant protective agent is applied to the cleaned multi-layer protective layer to reform the protective film, It can be considered acceptable.

[0013] According to this method, the alkaline cleaning agent can remove the protective coating by hydrolyzing the alkoxysilane in the protective coating that adheres to the undercoat. After cleaning and removing the protective coating, the undercoat remains on the multilayer protective layer, and the protective coating can be reformed by applying a water-resistant protective agent to the undercoat. [Effects of the Invention]

[0014] According to the water-resistant protective agent of the embodiment described herein, a flexible, rigid protective film is formed that adheres firmly and conforms to the substrate, and its surface is R 1 Si and R 2 It is coated with an alkylsilane of Si, which can suppress the adhesion of dirt. [Brief explanation of the drawing]

[0015] [Figure 1] This is a model cross-sectional view with an enlarged diagram of a plumbing fixture equipped with a multi-layer protective layer consisting of a primer film formed from an undercoat agent according to the embodiment of this specification and a protective film formed from a plumbing protective agent. [Figure 2] This is an illustrative process diagram of a repainting method according to an embodiment, where (A) shows cleaning a water-related facility equipped with a multi-layer protective coating using an alkaline cleaning agent, (B) shows the state in which the protective coating is peeled off by the alkaline cleaning agent, and (C) shows applying a water-related protective agent to the undercoat from which the protective coating has been peeled off. [Figure 3] This is a diagram showing the bonding structure units of silicone resin. [Modes for carrying out the invention]

[0016] The following describes the water-resistant protective agent, primer, painting method for water-resistant equipment, and repainting method according to the embodiments of this specification. Note that the scope of the present invention is not limited to the scope disclosed in the embodiments. The water-resistant protective agent of the embodiments is a protective agent applied to water-resistant areas such as bathrooms, kitchens, washrooms, and toilets, forming a protective film that suppresses the adhesion of dirt that occurs in these areas. Of course, the embodiments of this specification are not limited to water-resistant applications in buildings such as houses, but can also be applied to water-resistant areas in buildings such as commercial facilities and office buildings, railway vehicles, buses, ships, and aircraft. In this specification, when expressing the amount or ratio of the water-resistant protective agent, unless otherwise specified, the unit of mass is used, and the expression refers to the paint state including volatile components. Furthermore, unless otherwise specified, "%" representing the unit of composition means "mass%".

[0017] The materials of the plumbing fixtures 1 to which the water-resistant protective coating is applied include ceramics, stone, metal, and synthetic resin. Examples of stone materials include marble and granite. Examples of metals include enamel, which is made by coating a metal surface with a glassy glaze and firing it, and stainless steel sheets. Examples of synthetic resins include molded synthetic resin bodies made by molding synthetic resin and fillers, and fiber-reinforced plastic (FRP). While the materials of the plumbing fixtures 1 to which the water-resistant protective coating is applied are not particularly limited, it can be applied even to materials with poor adhesion, such as enamel and stainless steel sheets.

[0018] The multilayer protective layer 10 formed on the base material of the plumbing equipment 1 that constitutes the plumbing area according to the embodiment consists of an undercoat film 20 formed from an undercoat applied to the plumbing equipment 1, and a protective film 30 formed from a plumbing protective agent applied to the undercoat film 20.

[0019] The primer for the water-resistant protective agent that forms the undercoat film 20 has a bonding structure unit of formula (SiO 4 / 2 5 to 20% by mass of silicone (Q unit silicone) shown in ) and the bonding structure unit is given by formula ((R 6 O)3SiR 7 It contains 5 to 20% by mass of an alkylalkoxysilane (T-unit alkylalkoxysilane) represented by ), and 60 to 85% by mass of a diluent. The primer for water-resistant protective agents is composed of Q-unit silicone and T-unit alkylalkoxysilane as components that form the primer film 20.

[0020] Q unit silicone (SiO 4 / 2 ) is a silicone that can have four siloxane bond sites in silicon, and as a single structural unit, it is "(R 5 The structure is O)4Si, with four alkoxy groups (R 5The alkoxy group (R) of the Q-unit silicone undergoes hydrolysis and dehydration condensation (polymerization) with the alkoxy groups of other Q-unit silicones and T-unit alkylalkoxysilanes, forming a coating consisting of a rigid siloxane bond with a three-dimensional network structure. The Q-unit silicone, with its low degree of polymerization, penetrates the fine irregularities on the surface of the substrate of the water-related equipment 1, and can adhere firmly to the substrate of the water-related equipment 1 through an anchoring effect. 5 O) can be converted into a methoxy group or an ethoxy group, which undergo rapid hydrolysis and dehydration condensation reactions, and can be converted into a methoxy group, which undergoes even faster reactions.

[0021] Commercially available Q-unit silicones can also be used. Examples of commercially available Q-unit silicones include MKC Silicate MS51, MS56, MS57, MS56S (manufactured by Mitsubishi Chemical Corporation) and XIAMETER OFS-6697 Silane (manufactured by Dow-Toray Industries, Inc.).

[0022] A T-unit alkylalkoxysilane is a silane compound having three alkoxy groups and one alkyl group on silicon, where the alkoxy group (R 6 O) allows copolymerization (dehydration condensation reaction) with silicone and silicone resin, and as a standalone substance, it is "(R 6 O)3SiR 7 The structure is as follows: The primer film 2 formed from the primer is formed by copolymerization of the T-unit alkylalkoxysilane with the Q-unit silicone, and the alkyl(R) of the T-unit alkylalkoxysilane 7 ) provides flexibility and can follow the deformation of the base material of the plumbing equipment 1 without cracking. The alkoxy group (R) of the T unit alkylalkoxysilane 6 O) can be a methoxy group or an ethoxy group that undergoes rapid hydrolysis and dehydration condensation reactions, and a methoxy group can be formed more quickly. T unit alkylalkoxysilane alkyl(R 7 ) can provide moderate flexibility C8~C 12 It can be a medium-chain alkyl group. Note that the alkyl group (R) of the T-unit alkylalkoxysilane 7If the alkyl group (R) is a short-chain alkyl group of C7 or less, the primer film 20 formed from the primer may not have sufficient flexibility and may crack due to deformation of the substrate of the plumbing equipment 1. On the other hand, if the alkyl group (R) of the T-unit alkylalkoxysilane 7 ) is C 13 In the case of the long-chain alkyl groups described above, the primer film 20 formed from the primer may have excessive flexibility, potentially resulting in inferior strength of the primer film 20.

[0023] T-unit alkylalkoxysilanes can also be commercially available. DOWSIL Z-6341 Silane(n-C8H 17 Si(OC2H5)3), DOWSIL Z-6210 Silane(nC 10 H 21 Si(OCH3)3) (manufactured by Dow Toray Corporation), KBE-3083(n-C8H 17 Si(OC2H5)3), KBM-3103C(nC 10 H 21 You can use Si(OCH3)3) (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0024] The primer contains 60-85% by mass of a diluent. More specifically, the diluent is composed of volatile silicone oil and alcohol, with 20-60% by mass of volatile silicone oil and 20-60% by mass of alcohol relative to the total volume of the primer. The inclusion of a diluent in the primer allows the low-polymerization Q-unit silicone to be diluted by the diluent and penetrate into the fine irregularities on the surface of the substrate of the plumbing fixture 1, enabling it to adhere firmly to the plumbing fixture 1 through an anchoring effect.

[0025] As the volatile silicone oil to be included in the primer, cyclic siloxanes and dimethylpolysiloxanes can be used. In another embodiment, cyclic siloxanes with high volatility, such as decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), can be used, and in yet another embodiment, decamethylcyclopentasiloxane (D5) can be used.

[0026] As alcohol to be included in the primer, C2~C 12 A mixture of alcohols can be used. This is because the volatility of the diluent can be made suitable. If the alcohol contained in the primer is C1 alcohol (methanol), the diluent will volatilize quickly, which may result in poor workability of the primer. On the other hand, if the alcohol contained in the primer is C 12 If the alcohol has a molecular weight exceeding that of the alcohol (dodecanol), the diluent may volatilize slowly, potentially resulting in poor workability of the primer.

[0027] A curing catalyst may be added to the primer to accelerate curing. The curing catalyst can be any catalyst that can accelerate the curing reaction of the silicone resin, and oxides, amines, or metals can be used. In another embodiment, a metal catalyst with excellent curing properties can be used as the curing catalyst. In yet another embodiment, a titanium-based catalyst can be used among the metal catalysts, and among the titanium-based catalysts, a titanium organometallic compound catalyst (tetrabutyl titanate) can be used.

[0028] The curing catalyst can be added to the primer at a concentration of 0.5 to 5% by mass. This is because it can suitably improve the curability of the primer. If the amount of curing catalyst added to the primer is less than 0.5% by mass, it may not be possible to suitably improve the curability of the primer. On the other hand, if it exceeds 5% by mass, it may be an excessive amount and uneconomical. In another embodiment, the content of the curing catalyst in the primer can be 0.8 to 2% by mass.

[0029] If the primer contains a curing catalyst, it can be a two-component material (main component and curing agent) that allows the curing catalyst to be mixed into the primer immediately before application. By using a two-component material, the primer can suppress the acceleration of curing during storage. In this case, the main component can be a mixture of silicone and alkylalkoxysilane, and the curing agent can be a mixture of curing catalyst and diluent.

[0030] The water-resistant protective agent that forms the protective film 30 has a bonding structure unit of formula (R 1 SiO 3 / 2 A silicone resin represented by ) and a bonding structure unit with formula (R 2 2SiO 2 / 2 A mixture of silicone resin represented by ) is present in an amount of 30-75% by mass, and the bonding structural unit is given by formula ((R 3 O)3SiY 3 10 to 30% by mass of alkoxysilane represented by ) and the bonding structural unit is given by formula ((R 4 O)2SiCH3Y 4 It contains 10 to 30% by mass of an alkoxysilane represented by ).

[0031] Formula (R 1 SiO 3 / 2 Silicone resins (T-unit silicone resins) are composed of silicon with three siloxane bond sites and one alkyl group (R 1 It is a resin that has three siloxane bond bonding points, and therefore forms a hard coating with a three-dimensional network structure.

[0032] Formula (R 2 2SiO 2 / 2 Silicone resin (D-unit silicone resin) is a silicon atom with two siloxane bond sites and two alkyl groups (R 2 It is a resin having two siloxane bond points, and therefore forms a flexible film with a linear (two-dimensional) structure.

[0033] The water-resistant protective agent that forms the protective film 30 mainly contains a mixture of T-unit silicone resin with a three-dimensional network structure and D-unit silicone resin with a linear structure, and the formed protective film is a flexible yet rigid film. The surface of the formed protective film has water-repellent properties. 1 Si and R 2 It is coated with an alkylsilane of Si, which can suppress the adhesion of dirt.

[0034] The content ratio of T-unit silicone resin to D-unit silicone resin in the water-related protective agent that forms the protective film 30 can be set to a molar ratio of T-unit silicone resin / D-unit silicone resin = 50 / 50 to 90 / 10. This is because it is possible to form a flexible yet rigid film. If the content ratio of T-unit silicone resin to D-unit silicone resin is less than 50 / 50, the formed protective film 30 will become soft and may have inferior film strength. On the other hand, if the content ratio of T-unit silicone resin to D-unit silicone resin exceeds 90 / 10, the formed protective film 30 will become too hard and may not be able to follow the movement of the substrate of the water-related equipment 1, potentially causing cracks in the protective film 30. In another embodiment, the content ratio of T-unit silicone resin to D-unit silicone resin can be 55 / 45 to 75 / 25, and in yet another embodiment, it can be 60 / 40 to 70 / 30. Furthermore, in terms of coating hardness, T-unit silicone resin / D-unit silicone resin = 80 / 20 to 90 / 10 is hard, 70 / 30 to 80 / 20 is medium, and 60 / 40 to 70 / 30 is soft.

[0035] Alkyl(R) of T-unit silicone resin and D-unit silicone resin 1 , R 2 ) can be a methyl group or an ethyl group. 1 Si and R 2 This is because Si can be made to have excellent water-repellent properties. Note that alkyl groups (R 1 , R 2If the alkyl group (R) of the T-unit silicone resin and the D-unit silicone resin is longer than the propyl group, the protective film 30 that is formed may become soft and have inferior film strength. In another embodiment, the alkyl group (R) of the T-unit silicone resin and the D-unit silicone resin 1 , R 2 ) can be a methyl group.

[0036] A mixture of T-unit silicone resin and D-unit silicone resin can be used, and commercially available products can be used as a mixture of T-unit silicone resin and D-unit silicone resin (hereinafter sometimes referred to as DT-unit silicone resin). Examples of commercially available DT-unit silicone resins that can be used include KR-300, KR-255, KR-500, X-40-9218, X-40-9246, X-40-9250, X-40-9227, X-40-9238, X-40-2667A, X-40-2756, X-41-1056, KR-112, KR-282, KR-242A, and KR-9218 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0037] The bond structure unit is given by formula ((R 3 O)3SiY 3 Alkoxysilanes represented by (T-unit alkoxysilanes) contain one organic functional group (Y) in one molecule. 3 It is a compound containing three alkoxy groups (R 3 The alkoxysilyl group having O) undergoes hydrolysis and copolymerization with silicone resin due to moisture in the air, and chemically and physically bonds with the undercoat film 20, thereby adhering to the undercoat film 20 in three dimensions, and the protective film 30 formed from the water-resistant protective agent forms a strong and durable film.

[0038] On the other hand, the bond structure unit is given by formula ((R 4 O)2SiCH3Y 4 Alkoxysilanes represented by ) (D-unit alkoxysilanes) contain an organic functional group (Y) in one molecule. 4) A compound containing a group (alkoxysilyl group) having hydrolyzability and condensability. The alkoxysilyl group having two alkoxy groups (R 4 O) is hydrolyzed by moisture in the air and copolymerizes with the silicone resin, and chemically and physically bonds to the undercoat film 20, thereby adhering two-dimensionally to the undercoat film 20. The protective film 30 formed from the water surrounding protective agent forms a film so as to follow the undercoat film 20.

[0039] The alkoxy groups (R 3 O, R 4 O) of the T-unit alkoxysilane and the D-unit alkoxysilane can be methoxy groups or ethoxy groups with fast hydrolysis and dehydration condensation reactions, and can be methoxy groups with faster reactions.

[0040] The organic functional groups (Y 3 , Y 4 ) of the T-unit alkoxysilane and the D-unit alkoxysilane can be alkyl groups, vinyl groups or epoxy groups compatible with the alkyl groups (R 1 , R 2 ) of the T-unit silicone resin and the D-unit silicone resin. As another embodiment, it can be an alkyl group. Further, when the water surrounding protective agent is directly applied to the base material of the water surrounding facility 1 without passing through the undercoat film 20, it can have a vinyl group that can adhere to the base material.

[0041] The water surrounding protective agent for forming the protective film 30 contains 10 to 30% by mass of the T-unit alkoxysilane and 10 to 30% by mass of the D-unit alkoxysilane, but the content of the T-unit alkoxysilane can be more than the content of the D-unit alkoxysilane. This is because the time to tack-free can be shortened thereby.

[0042] As T-unit alkoxysilanes, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltrieth Xysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. can be used.

[0043] In addition, as D-unit alkoxysilanes, dimethyldimethoxysilane, dimethyldiethoxysilane, ethylmethyldimethoxysilane, ethylmethyldiethoxysilane, propylmethyldimethoxysilane, propylmethyldiethoxysilane, butylmethyldimethoxysilane, butylmethyldiethoxysilane, pentylmethyldimethoxysilane, pentylmethyldiethoxysilane, hexylmethyldimethoxysilane, hexylmethyldiethoxysilane, heptylmethyldimethoxysilane, heptylmethyldiethoxysilane, octylmethyldimethoxysilane, octylmethyldi Ethoxysilane, nonylmethyldimethoxysilane, nonylmethyldiethoxysilane, decylmethyldimethoxysilane, decylmethyldiethoxysilane, undecylmethyldimethoxysilane, undecylmethyldiethoxysilane, dodecylmethyldimethoxysilane, dodecylmethyldiethoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, etc. can be used.

[0044] The water-resistant protective agent contains 1 to 10% by mass of a diluent. The diluent is C 10 ~C 14 The hydrocarbon can be used. This is because the volatility of the diluent can be made suitable. The hydrocarbon to be included in the water-resistant protective agent is C 10 If the hydrocarbon has a smaller molecular weight than the hydrocarbon (decane), the diluent may volatilize quickly, potentially resulting in poor workability of the water-resistant protective agent. On the other hand, if the alcohol contained in the primer is C 14 If the hydrocarbon has a molecular weight greater than that of the hydrocarbon (tetradecane), the diluent may volatilize slowly, potentially resulting in poor workability of the primer.

[0045] For the water surrounding protective agent, a curing catalyst can be added to accelerate the curing. The curing catalyst can be any substance that can accelerate the curing reaction of the silicone resin, and oxides, amines or metals can be used. In another embodiment, a metal catalyst with excellent curing properties can be used as the curing catalyst. In yet another embodiment, a titanium-based catalyst can be used among the metal catalysts, and a titanium organometallic compound-based catalyst (tetrabutyl titanate) can be used among the titanium-based catalysts.

[0046] The curing catalyst can be added to the water surrounding protective agent at 0.5 to 5% by mass. This is because the curability of the water surrounding protective agent can be preferably improved. If the addition amount of the curing catalyst to the water surrounding protective agent is less than 0.5% by mass, there is a possibility that the curability of the water surrounding protective agent cannot be preferably improved. On the other hand, if it exceeds 5% by mass, it will be an excessive addition amount and may be uneconomical. In another embodiment, the content of the curing catalyst in the water surrounding protective agent can be 0.8 to 2% by mass.

[0047] When the water surrounding protective agent contains a curing catalyst, it can be a two-component material (main agent and curing agent) in which the curing catalyst is mixed with the water surrounding protective agent immediately before coating. By using a two-component material, the water surrounding protective agent can suppress the acceleration of curing during the storage of the material. In this case, the main agent can be a mixture of silicone resin and alkoxysilane, and the curing agent can be a mixture of a curing catalyst and a diluent.

[0048] By coating the water surrounding protective agent on the undercoat film 20, the silanol groups formed by the hydrolysis of the alkoxy groups (R 3 O, R 4 O) of the alkoxysilane of the T unit and the D unit bind to the undercoat film 20 and undergo a dehydration condensation reaction with the silicone resin of the T unit and the D unit, thereby forming a protective film 30 composed of hard siloxane bonds with a three-dimensional network structure. The surface of the protective film 30 has water repellency of R 1 Si and R 2It is presumed that the coating of Si alkylsilane can suppress the adhesion of dirt.

[0049] Furthermore, the water-resistant protective agent contains organic functional groups (Y) of T-unit alkoxysilanes and D-unit alkoxysilanes. 3 , Y 4 By using vinyl or epoxy groups, the water-related protective agent having vinyl or epoxy groups can be directly applied to the substrate of the water-related equipment 1. When applied to the substrate of the water-related equipment 1, the vinyl or epoxy groups of the T-unit and D-unit alkoxysilane adhere closely to the substrate of the water-related equipment 1. 3 O, R 4 The silanol groups formed by the hydrolysis of O) undergo a dehydration condensation reaction with T-unit and D-unit silicone resin to form a protective film 30 consisting of rigid siloxane bonds in a three-dimensional network structure.

[0050] Next, we will explain the method for applying the water-resistant protective agent. The application method for the water-resistant protective agent is carried out in the following order: degreasing step, primer application step, and protective agent application step.

[0051] The degreasing process is a process of removing oil and grease from the water fixture 1, which is the surface to be painted, and cleaning it. The degreasing process is carried out by wiping off oil and grease with a cloth using a cleaning agent. If there is little dirt (only fingerprints), use ethanol as the cleaning agent; if there is little dirt (some dirt components such as oil and grease are present), use cleaning thinner (lacquer thinner); and if there is dirt (water fixtures that have already been used and have oil, protein, silica, etc. attached), use the alkaline cleaning agent described later.

[0052] The primer application process involves applying a primer to the cleaned plumbing fixtures 1. The primer is applied to the plumbing fixtures 1 using a spray or brush and then spread with a cloth. The primer applied to the plumbing fixtures 1 contains Q-unit silicone that penetrates the fine irregularities on the surface of the plumbing fixtures 1, forming a strong primer film 20 that adheres firmly due to the anchoring effect.

[0053] The protective coating process involves applying a water-resistant protective agent to the plumbing fixtures 1 on which a primer film 20 has been formed. The water-resistant protective agent is applied to the plumbing fixtures 1 on which the primer film 20 has been formed using a spray or brush, and then spread with a cloth. The protective film 30 formed from the water-resistant protective agent adheres firmly and conformably to the primer film 20 because the T-unit silicone resin, D-unit silicone resin, T-unit alkoxysilane, and D-unit alkoxysilane contained in the water-resistant protective agent crosslink with the Q-unit silicone and T-unit alkylalkoxysilane of the primer film 20. The protective film 30 formed from the water-resistant protective agent has its surface coated with alkylsilane, which suppresses the adhesion of dirt.

[0054] Next, the method for repainting the plumbing fixture 1 will be explained. In the method for repainting the plumbing fixture 1, an alkaline cleaning agent is used to remove the protective film 30 of the multi-layer protective layer 10.

[0055] The alkaline cleaning agent works by cleaning the multilayer protective layer 10 with the alkaline cleaning agent, thereby hydrolyzing the silanol bonds of the T-unit and D-unit alkoxysilanes in the protective film 30 that are bonded to the undercoat film 20, and thus peeling the protective film 30 from the undercoat film 20. The alkaline cleaning agent consists of alkali (alkaline compound), abrasive, thickener, and water.

[0056] As the alkali in the alkaline cleaning agent, sodium hydroxide (NaOH, 12.8), sodium orthosilicate (Na4SiO4, 12.6), sodium metasilicate (Na2SiO3·5H2O, 11.4), sodium carbonate (Na2CO3, 11.2), sodium phosphate (Na3PO4·12H2O, 11.2), etc., can be used. The values ​​in parentheses indicate the structural formula and the pH of a 5% by mass aqueous solution. In another embodiment, the alkali in the alkaline cleaning agent can be sodium metasilicate, sodium carbonate, or sodium phosphate. This is because sodium hydroxide and sodium orthosilicate have a high pH in their 5% by mass aqueous solutions, which may hydrolyze the siloxane bonds of the silicone resin in the undercoat film 20.

[0057] The alkaline cleaning agent can be used as a 2-10% by mass aqueous solution of alkali. This is because it can suitably peel the protective film 30 from the undercoat film 20. If the alkali concentration is less than 2% by mass, there is a risk that the silanol bonds of the T-unit and D-unit alkoxysilane in the protective film 30 cannot be hydrolyzed. On the other hand, if the alkali concentration exceeds 10% by mass, there is a risk that the siloxane bonds of the silicone resin in the undercoat film 20 will also be hydrolyzed. In another embodiment, the alkali concentration of the alkaline cleaning agent can be 3-5% by mass.

[0058] The abrasive is used to polish the protective film 30 when cleaning the multilayer protective layer 10, thereby promoting the removal of the protective film 30. Commercially available abrasives can be used, and materials such as alumina, silicon carbide, cerium, and diamond can be used. The average particle size (median diameter d50) of the abrasive can be 0.2 to 10 μm, and in another embodiment, it can be 0.8 to 3 μm. Furthermore, the abrasive can be included in the alkaline cleaning agent at a concentration of 10 to 30% by mass, and in another embodiment, it can be included at a concentration of 20 to 25% by mass.

[0059] The thickening agent is an additive that prevents the abrasive from settling in the alkaline cleaning agent and imparts viscosity to improve the wiping properties of the alkaline cleaning agent. Commercially available thickening agents such as methylcellulose and hydroxyethylcellulose can be used and can be included in the alkaline cleaning agent at a concentration of 1 to 3% by mass. In another embodiment, the thickening agent can be included in the alkaline cleaning agent at a concentration of 1 to 2% by mass.

[0060] The method for repainting a plumbing fixture 1 equipped with a multilayer protective layer 10 according to the embodiment includes a cleaning step of cleaning the plumbing fixture equipped with the multilayer protective layer 10 consisting of an undercoat 20 and a protective film 30 using an alkaline cleaning agent, and a protective agent repainting step performed after the cleaning step, in which a plumbing protective agent is applied to the cleaned multilayer protective layer 10 to reform the protective film 30. The multilayer protective layer 10 formed on the plumbing fixture 1 has its surface covered with alkylsilane, which can suppress the adhesion of dirt, but with long-term use, dirt may adhere due to scratches, wear and tear, and repainting may be necessary.

[0061] The cleaning process, as shown in Figure 2(A), involves using an alkaline cleaning agent to hydrolyze the alkoxysilane in the protective film 30 that adheres to the undercoat 20, thereby removing the protective film 30. The cleaning process is carried out by wiping the multilayer protective layer 10 from above with a cloth or the like using an alkaline cleaning agent. At this time, the abrasive contained in the alkaline cleaning agent polishes and physically removes the protective film 30 that adheres to the undercoat 20, and the alkali hydrolyzes the alkoxysilane in the protective film 30, allowing only the protective film 30 to be removed while leaving the undercoat 20 intact (Figure 2(B)).

[0062] The protective coating repainting process, as shown in Figure 2(C), involves applying a water-resistant protective coating to the plumbing fixtures 1 on which the undercoat 20 remains. The water-resistant protective coating is applied to the plumbing fixtures 1 on which the undercoat 20 remains using a spray or brush, and then spread with a cloth. The protective film 30 formed from the water-resistant protective coating adheres firmly and conformably to the undercoat because the T-unit silicone resin, D-unit silicone resin, T-unit alkoxysilane, and D-unit alkoxysilane contained in the water-resistant protective coating crosslink with the Q-unit silicone and T-unit alkylalkoxysilane of the undercoat. The protective film 30 formed from the water-resistant protective coating has its surface coated with alkylsilane, which again suppresses the adhesion of dirt. [Examples]

[0063] Table 1 shows the formulation of the primer used in the example, Table 2 shows the formulation of water-resistant protective agent A, Table 3 shows the formulation of water-resistant protective agent B, Table 4 shows the formulation of the alkaline cleaning agent, and Table 5 shows the details of the DT unit silicone resin used in the water-resistant protective agent.

[0064] [Table 1]

[0065] [Table 2]

[0066] [Table 3]

[0067] [Table 4]

[0068] [Table 5]

[0069] In the examples, gloss tests, water repellency tests, and stain adhesion tests were conducted and evaluated. The evaluation methods for each test are as follows.

[0070] <Glossiness Test> The gloss test involved visually assessing the gloss of the test specimens compared to a blank (bathroom fixture 1 before installation). A rating was assigned as follows: ◎ for superior gloss compared to the blank, ○ for gloss equivalent to the blank, △ for slightly inferior gloss, and × for clearly inferior gloss.

[0071] <Water repellency test> In the water repellency test, tap water was sprayed onto the test specimen using a spray bottle, and the difference in water repellency compared to the blank was visually judged. The water repellency was evaluated as follows: ◎ for superior water repellency compared to the blank, ○ for water repellency equivalent to the blank, △ for slightly inferior water repellency compared to the blank, and × for clearly inferior water repellency compared to the blank.

[0072] <Dirt adhesion test> In the stain adhesion test, 5g of chili oil (manufactured by S&B Foods Co., Ltd.) was applied to the test specimen (water fixture 1) with a brush, rinsed with water, and then the surface of the test specimen was wiped with tissue paper. The presence or absence of remaining stains (chili oil) was visually checked. A circle (○) was used to indicate that no stains remained, and a cross (×) was used to indicate that stains remained.

[0073] Table 6 lists the plumbing fixtures 1 targeted for construction, the construction procedure, and the evaluation results of the above tests for each example.

[0074] [Table 6]

[0075] (Example 1) Example 1 involved applying a water-resistant protective agent to a stainless steel kitchen sink that had been used for approximately one year. The application procedure was as follows: 1. Cleaning with alkaline cleaning agent A 2. Applying primer A. 3. Water-resistant protective coating A The kitchen sink, which had been used for one year, had many scratches and dirt had accumulated in the scratches, but the dirt was cleaned with alkaline cleaning agent A. By applying primer A, primer A penetrated into the scratches through an anchoring effect, forming a primer film 20 that adheres firmly and conforms to the substrate. By applying water-resistant protective agent A, the T-unit silicone resin, D-unit silicone resin, T-unit alkoxysilane, and D-unit alkoxysilane contained in the water-resistant protective agent crosslinked with the Q-unit silicone and T-unit alkylalkoxysilane of the primer film, forming a protective film 30 that adheres firmly and conforms to the primer film. The surface of the protective film 30 has water-repellent properties. 1 Si and R 2 Because it was coated with an alkylsilane of Si, it was able to suppress the adhesion of dirt and had a high gloss.

[0076] (Example 2) Example 2 involved repainting a stainless steel kitchen sink, which had been treated with the water-resistant coating in Example 1, for approximately one year. The application procedure was as follows: 1. Cleaning with alkaline cleaning agent A 2. Water-resistant protective coating A The kitchen sink treated with the water-resistant protective agent in Example 1 had a high gloss and excellent water repellency and stain resistance, but after one year of use, it had developed many scratches. By cleaning the kitchen sink treated with the water-resistant protective agent using alkaline cleaning agent A (Figure 2(A)), the silanol bonds of the T-unit and D-unit alkoxysilane in the protective film 30, which were bonded to the undercoat 20, were hydrolyzed, and the protective film 30 was peeled off from the undercoat 20 (Figure 2(B)). At this time, the undercoat 20, which adheres firmly and conforms to the substrate, remained on the stainless steel base material without peeling off. By reapplying the water-resistant protective agent A, it was possible to form a protective film 30 with a high gloss and excellent water repellency and stain resistance.

[0077] (Example 3) Example 3 involved applying a water-resistant protective agent to an unused fiber-reinforced plastic (FRP) bathtub. The application procedure was as follows: 1. Degreasing using ethanol 2. Applying primer A. 3. Water-resistant protective coating B By applying primer A to the degreased FRP bathtub, a primer film 20 was formed in which primer A adhered firmly and closely to the FRP due to its anchoring effect. By applying water-resistant protective agent A, a protective film 30 was formed, similar to Example 1, which has high gloss and excellent water repellency and stain resistance.

[0078] (Example 4) Example 4 involved repainting a fiber-reinforced plastic (FRP) bathtub, which had been treated with the water-resistant coating in Example 3, for approximately one year. The application procedure was as follows: 1. Cleaning with alkaline cleaning agent A 2. Water-resistant protective coating B Similar to Example 2, the protective film 30 was removed from the undercoat film 20 by cleaning with alkaline cleaning agent A. The undercoat film 20 remained on the FRP substrate without peeling off. By applying water-resistant protective agent B again, a protective film 30 with high gloss, water repellency, and excellent stain resistance was formed.

[0079] (Example 5) Example 5 involved applying a water-resistant protective agent to an unused enamel bathtub. The application procedure was as follows: 1. Degreasing using ethanol 2. Water-resistant protective coating A Example 5 omits the primer. By applying water-resistant protective agent A to a degreased enamel bathtub, the T-unit alkoxysilane and D-unit alkoxysilane adhered to the enamel glaze, forming a protective film 30 with high gloss, excellent water repellency, and stain resistance.

[0080] (Example 6) Example 6 involved applying a water-resistant protective agent to a bathtub made of molded synthetic resin that had been used for approximately one year. The application procedure was as follows: 1. Cleaning with alkaline cleaning agent A 2. Water-resistant protective coating B Example 6 omits the primer. The bathtub to be treated is a synthetic resin molded body that has been used for about one year. It is cleaned with alkaline cleaning agent A, and then the water-resistant protective agent A is applied to the cleaned synthetic resin molded bathtub. This allows the T-unit alkoxysilane and D-unit alkoxysilane to adhere to the enamel glaze, forming a protective film 30 with high gloss, excellent water repellency, and stain resistance.

[0081] According to the water-resistant protective agent of this embodiment, the rigid bonding structure unit that cross-links in three dimensions is given by formula (R 1 SiO 3 / 2 The silicone resin (T-unit silicone resin) shown by ) and the soft bonding structure unit that cross-links in two dimensions are given by formula (R 2 2SiO 2 / 2 The main component is a mixture with a silicone resin (D-unit silicone resin) represented by ). Therefore, the protective film 30 formed from the water-repellent protective agent according to the embodiment forms a flexible, rigid protective film 30 in which rigid three-dimensional crosslinking of T-unit silicone resin is mainly added, along with two-dimensional crosslinking of D-unit silicone resin. The surface of this film has water-repellent properties. 1 Si and R 2 Because it is coated with an alkylsilane of Si, the adhesion of dirt can be suppressed. In addition, the water-resistant protective agent according to the embodiment has a bonding structure unit of formula ((R 3 O)3SiY 3 Alkoxysilanes (T-unit alkoxysilanes) represented by ) and bond structure units are given by formula ((R 4 O)2SiCH3Y 4Because it contains alkoxysilane (D-unit alkoxysilane) represented by ), the T-unit alkoxysilane crosslinks with the silicone resin and adheres to the plumbing equipment 1 three-dimensionally, while the D-unit alkoxysilane crosslinks with the silicone resin and adheres linearly (two-dimensionally) to the substrate. In other words, the plumbing protective agent according to the embodiment adheres to the plumbing equipment 1 in a conforming manner, forming a durable protective film 30, and since its surface is coated with alkylsilane, it can suppress the adhesion of dirt.

[0082] Other technical ideas derived from the water-resistant protective agent of the embodiment configured as described above are described below.

[0083] A method for applying a water-resistant protective agent, wherein the primer does not contain a curing catalyst, and the water-resistant protective agent contains a curing catalyst.

[0084] According to this method, the curing time of the primer can be extended, and by applying the water-resistant protective agent during the curing of the primer, the T-unit silicone resin, D-unit silicone resin, T-unit alkoxysilane, and D-unit alkoxysilane contained in the water-resistant protective agent can be strongly crosslinked with the Q-unit silicone and T-unit alkylalkoxysilane of the primer. [Explanation of Symbols]

[0085] 1...Water-related equipment, 10...Multi-layer protective layer, 20...Undercoat film, 30...Protective film.

Claims

1. A water-related protective agent that suppresses the adhesion of dirt to water-related equipment, A mixture of a silicone resin represented by the formula (R 1 SiO 3 / 2 ), in the bonding structural unit, and a silicone resin represented by the formula (R 2 2 SiO 2 / 2 ), in the bonding structural unit, is 30 to 75% by mass, an alkoxysilane represented by the formula ((R 3 O) 3 SiY 3 ), in the bonding structural unit, is 10 to 30% by mass, and an alkoxysilane represented by the formula ((R 4 O) 2 SiCH 3 Y 4 ), in the bonding structural unit, is 10 to 30% by mass. A water repellent characterized by containing these components.

2. A primer for a water-resistant protective agent according to claim 1, The bond structure unit is given by formula (SiO 4 / 2 5 to 20% by mass of silicone represented by ) and the bonding structure unit is given by formula ((R 6 O) 3 SiR 7 A primer characterized by containing 5 to 20% by mass of an alkyltrialkoxysilane represented by ) and 60 to 85% by mass of a diluent.

3. A method for painting plumbing fixtures, comprising: a primer application step of applying the primer described in claim 2 to plumbing fixtures to form a primer film; and a protective coating step of applying the plumbing protective agent described in claim 1 to the primer film to form a protective film, characterized in that a multi-layer protective layer is formed consisting of the primer film and the protective film.

4. A method for repainting the multi-layer protective layer formed by the painting method for plumbing fixtures described in claim 3, A cleaning process using an alkaline cleaning agent, A protective agent recoating step is performed after the cleaning step, in which the water-resistant protective agent described in claim 1 is applied to the cleaned multilayer protective layer to reform the protective film, A method for repainting plumbing fixtures, characterized by having the following features.

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