JP7253346B2 - Hydrophilic antifouling coating structure with antibacterial properties, method for forming the same, surveying instrument - Google Patents

Description

The present invention relates to a technology for improving the antifouling and antibacterial properties of the surface of articles made of resin, and in particular, a hydrophilic antifouling coating structure with antibacterial properties, a method for forming the same, and a housing having a hydrophilic antifouling coating structure. Regarding surveying instruments.

Surveying instruments such as rotating lasers used at construction sites and pipe lasers used at sewage pipe construction sites are used in harsh outdoor environments such as sewage pipes, so they are exposed to rainwater, soil, There was a problem that dirt such as cement and filth and bacteria harmful to the human body adhered to the surveying instrument.

When wiping off these dirt and bacteria from the housing of the surveying instrument, the dirt itself is difficult to remove, and in the case of cement, scratches due to particles remain, and stains of the ingredients contained in the dirt remain. was there.

As an antifouling coat for preventing the attachment of such stains and facilitating removal when attached, conventionally, for example, monomolecular repellents sold by Daikin, Shin-Etsu Chemical, Dow Corning, 3M, etc. Raw materials for water and oil repellent coatings are known (see Patent Documents 1 and 2, for example).

Since this monomolecular water- and oil-repellent coating raw material has an ether bond in the molecule of the active ingredient, the long-chain structure molecules are oriented in a specific direction to form a monomolecular film on the surface of the article. It is known that the monomolecular film containing this ether bond improves the antifouling property of the water-repellent and oil-repellent coating layer when applied to an article due to its high water-repellent angle.

Fluoroalkylsilane compounds, for example, are known as fluorine-based water- and oil-repellent coats that do not have ether bonds. Since this water- and oil-repellent coating layer has a fluorine functional group, it is difficult for stains to adhere to it, and the stability of the molecules constituting the water- and oil-repellent coating layer is high compared to those having ether bonds. , the durability of the membrane is high.

In addition, in claim 4 and paragraph 0022 of Patent Document 3, by making the drain hole and part or the entire surface around the drain hole hydrophilic, it functions as a flow path for collecting and draining water accumulated in the main body. A laser marking device is disclosed.

Further, in paragraph 0012 of Patent Document 4, a coating composition for coating the surface of construction machinery,
Although the reason for this is not clear, a coating film containing both a fluororesin network derived from the fluoropolymer (A) and a network derived from the metal alkoxide (B) (for example, a siloxane skeleton network) can be obtained. that the fluororesin derived from the fluoropolymer (A) is present in the coating film, and that the function of this fluororesin is secured; It is written that there is a silanol group that is, and that dirt can be easily washed away with water, etc., and paragraph 0078 states that construction machines include, for example, measurement or surveying equipment. there is

On the other hand, with regard to antibacterial properties, Ag, Cu, and Zn are described as preferred examples of metal ions having a bactericidal effect in page 2, lower right column, lines 7 to 9 of Patent Document 5.

Japanese Patent No. 3275402 Japanese Patent No. 3433024 Japanese Patent No. 4458287 JP 2017-88659 A JP-A-59-133235

However, in the conventional monomolecular water- and oil-repellent coats as shown in Patent Documents 1 and 2, although the adhesion of many substances is suppressed by the water- and oil-repellent performance of the fluorine-based functional groups, the dirt and other components In spite of the presence of fluorine-based functional groups, there are also components that adhere and are difficult to remove, and if such components adhere to the monomolecular water- and oil-repellent coating, there is a problem that the subsequent work is hindered.

In addition, in the technique described in Patent Document 3, only the drainage hole of the laser marking device and a part or the entire surface around the drainage hole are hydrophilic, and the entire body of the laser marking device is not hydrophilically treated. However, since it is treated to be water repellent, for example, when the main body is soaked in sewage water, some components such as dirt, like the conventional monomolecular water and oil repellent coats of Patent Documents 1 and 2 The dirt caused by the dust will not come off, and the work will be interrupted.

In the technique described in Patent Document 4, an OH group is used in order to exert a hydrophilic effect, but the OH group may react with dirt molecules, and the antifouling effect due to the hydrophilicity. durability is not good. Therefore, it is only prior art.

Furthermore, the technique described in Patent Document 5 is a technique for converting zeolite to Ag-zeolite by ion exchange, and is configured to exhibit an antibacterial effect by mixing metal ions into the hydrophilic coating targeted by the present invention. Nothing is written about

The present invention has been made in view of the above situation, and solves the problems of dirt components and adhesion of harmful bacteria in conventional monomolecular water and oil repellent coatings, and provides a hydrophilic coating structure having antibacterial properties and high durability. It is an object of the present invention to provide a surveying instrument having a forming method and a hydrophilic antifouling coating structure with antibacterial properties on the housing.

In the present specification, a substrate layer, a glass-like coat layer provided on the substrate layer, and a betaine structure layer provided on the glass-like coat layer, the glass-like coat layer and the betaine The structure layer discloses a hydrophilic antifouling coating structure containing 1% by weight or more of silver ions.

In the specification of the present application, a substrate layer, a coating resin layer provided on the substrate layer, and a betaine structure layer provided on the coating resin layer are provided, and the coating resin layer and the betaine structure layer discloses a hydrophilic antifouling coating structure containing 1% by weight or more of silver ions.

The invention according to claim 1 for solving the above problem is a method for forming a hydrophilic antifouling coating structure, comprising a substrate layer, a glass-like coat layer provided on the substrate layer, and the glass-like coat layer. A method for forming a hydrophilic antifouling coating structure comprising a betaine structure layer composed of a betaine portion and a silane portion provided in the above, wherein the glass-like coat layer and the betaine structure layer contain 1% by mass or more of silver ions. A solvent containing 1% by mass or more of silver ions and tetraalkoxysilane is applied to the surface of the base material layer, and the alkoxysilane is hydrolyzed to form a glass-like material containing silver ions in the base material layer. A coat layer is formed, and a solvent containing 1% by mass or more of silver ions and a betaine structure composed of a betaine moiety and an alkoxysilane moiety is applied to the glass-like coat layer to remove the alkoxysilane moiety of the betaine structure. A betaine structure layer containing silver ions is formed on the glass-like coat layer by hydrolysis. and a tetraalkoxysilane in which the two functional groups are different .

The invention according to claim 2 is characterized in that, in the invention according to claim 1 , the substrate layer is a resin layer, and the solvent containing the tetraalkoxysilane contains an etching component for the resin layer. do.

In the present specification, a solvent containing 1% by mass or more of silver ions, a tetraalkoxysilane, and a betaine structure is applied to the surface of the base material layer, and the alkoxysilane and the silane portion of the betaine structure are hydrated. Disclosed is a method for forming a hydrophilic anti-fouling coating structure that decomposes to form a glass-like coating layer containing silver ions and a betaine structure layer on the substrate layer.

In the specification of the present application, a solvent containing 1% by mass or more of silver ions, a coating resin, and a betaine structure is applied to the surface of the substrate layer, and the silane portion of the betaine structure is hydrolyzed to obtain the A method for forming a hydrophilic antifouling coating structure is disclosed in which a coating resin layer containing silver ions and a betaine structure layer are formed on a substrate layer.

According to the present invention, tetraalkoxysilane is condensation-polymerized to form a glass-like coat layer composed of silicon and oxygen, and the OH groups of the substrate and the OH groups of the glass-like coat layer are condensed. Alternatively, when the base material is a resin poor in OH groups, the surface of the resin is dissolved by adding an etching component to the solvent to form fine unevenness on the surface of the resin layer, and the glass-like coating layer becomes the unevenness of the resin layer. are physically attached via

Furthermore, the silane portion of the betaine structure undergoes condensation polymerization to form a betaine structure layer, and also condenses with the OH groups of the glass-like coat layer to form siloxane bonds.

In this way, the substrate layer and the glass-like coating layer are physically or chemically bonded, and the glass-like coating layer and the betaine structure layer are chemically bonded, so that the adhesion between the three is significantly improved. do. As a result, the hydrophilicity of the betaine structure portion protruding to the outermost surface can be exhibited for a long period of time, and the hydrophilicity of the resin casing used in a harsh environment can be improved. In the present invention, since the antifouling coating is made hydrophilic based on the idea opposite to the conventional water- and oil-repellent coating, dirt easily adheres temporarily, but since the coating is hydrophilic, water Water enters the coat surface by washing, and an effect is obtained that dirt can be easily washed off.

Furthermore, in the present invention, silver ions are contained in both the glass-like coating layer or the coating resin and the betaine structure layer. can.

FIG. 4 is a cross-sectional view schematically showing the formation process of the hydrophilic antifouling coating structure according to the first embodiment of the present invention; FIG. 5 is a cross-sectional view schematically showing a formation process of a hydrophilic antifouling coating structure according to a second embodiment of the present invention; FIG. 2 shows the structure of the betaine structure of the present invention; It is a schematic diagram which shows the chemical state in the glass-like coat layer lamination process of 1st Embodiment. It is a schematic diagram which shows the chemical state in the glass-like coat layer lamination process of 1st Embodiment. FIG. 2 is a schematic diagram showing a chemical state in a betaine structure layer lamination step after lamination of a glass-like coat layer in the first embodiment. FIG. 3 is a schematic diagram showing a chemical state after lamination of betaine structure layers of the first embodiment. FIG. 10 is a schematic diagram showing a chemical state in a one-liquid lamination step of a hydrophilic layer having a glass-like coat portion and a betaine structure portion of the second embodiment. FIG. 10 is a schematic diagram showing a chemical state after one-liquid lamination of a hydrophilic layer having a glass-like coat portion and a betaine structure portion of the second embodiment. FIG. 10 is a schematic diagram showing a chemical state in a one-liquid lamination step of a hydrophilic layer having a coating resin (polyester) portion and a betaine structure portion of the third embodiment. FIG. 10 is a schematic diagram showing the chemical state after one-liquid lamination of a hydrophilic layer having a coating resin (polyester) portion and a betaine structure portion of the third embodiment. FIG. 10 is a schematic diagram showing the chemical states of two types of alkoxysilanes forming the glass-like coat layer of the fourth embodiment. FIG. 11 is a schematic diagram showing a chemical state after lamination of a glass-like coat layer according to the fourth embodiment. FIG. 11 is a schematic diagram showing a chemical state after lamination of a glass-like coat layer according to the fourth embodiment. FIG. 10 is a schematic diagram showing a chemical state in a process of laminating a betaine structure layer after lamination of a glass-like coat layer in the fourth embodiment. FIG. 10 is a schematic diagram showing a chemical state after lamination of betaine structure layers according to the fourth embodiment. 1 is photographs showing the test results of Example 1 and Comparative Example 1, where (a) shows a state where the surface of the surveying instrument is soiled with waste such as sewage, and (b) shows a state where the surface is washed with water. 1 is a perspective view of a laser irradiation device that is a specific example of the present invention; FIG. 1 is a perspective view of a laser irradiation device that is a specific example of the present invention; FIG.

The present invention will now be described in more detail.
1. First Embodiment: Two-liquid Lamination of Glass-like Coat Layer and Betaine Structure Layer (1-1. Configuration)
FIG. 1 shows a hydrophilic antifouling coating structure 1 according to a first embodiment of the present invention. 4 to 7 show the chemical state when forming each layer of the hydrophilic antifouling coating structure 1. FIG.

In FIG. 1(d), reference numeral 10 denotes a base material made of resin such as ABS, and the main purpose of the present invention is to apply it to housings of surveying instruments, but the present invention is not limited thereto. Surveying instruments include a pipe laser device for detecting whether multiple sewage pipes are arranged in a straight line, a rotating laser device for detecting the horizontal position in a house, and a GPS (Global Positioning System). Positioning system) main unit and antenna for receiving and transmitting radio waves, scanner for detecting topographic information as digital information, spectroscopic analyzer for detecting the growth status of crops such as rice, UAV for photographing topographic information from the sky ( Also called unmanned aerial vehicles, unmanned aerial vehicles, and drones.) and other devices.

A glass-like coat layer 11 containing silver ions and mainly composed of silicon and oxygen is laminated on a resin base material 10 which is etched to form nano-order fine unevenness on the surface. The glass-like coat layer 11 enters into fine recesses on the surface of the resin substrate 10, and the two are physically bonded together by an anchor effect.

A betaine structure layer 12 containing silver ions is laminated on the glass-like coat layer 11 . In both layers, the OH groups present on the surface of the glass-like coat layer 11 and the OH groups present on the surface (lower side) of the betaine structure layer 12 are condensed and chemically formed by siloxane bonds (Si—O—Si). It is in a combined state.

Here, "betaine" has a positive charge and a negative charge at non-adjacent positions in the same molecule, and the positively charged atom does not have a dissociable hydrogen atom (quaternary ammonium, sulfonium , which has a cationic structure such as phosphonium), and compounds (inner salts) that do not have an electric charge as a whole molecule, and are widely present in plants and marine products in the natural world, and are used as moisturizing agents in food additives and cosmetics. used as a drug. Commonly used names for these are betaine, and trimethylglycine represented by the chemical formula C ₅ H ₁₁ NO ₂ and glycine betaine are known as typical compounds.

The "betaine structure" in the present invention means a compound having such betaine as a functional group in its part, and an example of its structure is shown in FIG. FIG. 3 shows an example of a betaine structure employing trimethylglycine as the betaine structure. The betaine structure of the present invention consists of a betaine structure portion A in the upper part of the drawing and a silane portion B in the lower part of the drawing.

As shown in FIG. 7, the betaine structure portion is oriented on the surface (upper side) of the betaine structure layer 12, and is polarized into positive charges on the nitrogen atoms and negative charges on the oxygen atoms, and is hydrophilic. indicates As a result, it exhibits antifouling properties capable of removing stains by rinsing with water against adhesion of stains and generation of stains due to stain components.

(1-2. Forming process)
Next, the process of forming the hydrophilic coating structure of the first embodiment will be described. As shown in FIG. 1(a), a base material 10 made of resin, which is a housing for a surveying instrument or the like, is prepared. The surface of the resin base material 10 may have unevenness such as embossing or texturing from the beginning, or may be smooth. The figure shows a smooth state.

Subsequently, as shown in FIG. 1(b), a silver compound, a tetraalkoxysilane, a component capable of dissolving the resin substrate 10, and optionally other additives are applied to the surface of the resin substrate 10. are dissolved in a solvent capable of dissolving them (hereinafter sometimes referred to as a glass-like coating agent).

When the glass-like coating agent is applied and allowed to stand still, a component (etching component) capable of dissolving the resin base material 10 dissolved in the solvent corrodes the surface of the resin base material 10, as shown in FIG. 1(c). As described above, nano-order fine unevenness is formed on the surface of the resin base material 10 . At the same time, as shown in FIGS. 4 and 5, the alkoxy groups of the tetraalkoxysilane are hydrolyzed by atmospheric moisture and undergo condensation polymerization to form a glass-like network. As shown in FIGS. 1(c) and 5, the glass-like coat layer 11 hardens in a state of entering the fine recesses of the resin substrate 10, and is physically adhered by the anchor effect. On the surface of the glass-like coat layer 11, a large number of OH groups produced by hydrolysis of the alkoxy groups of tetraalkoxysilane protrude to the surface. Further, the glass-like coat layer 11 contains silver ions.

Next, as shown in FIG. 6, a silver compound, a betaine structure, and optionally other additives are coated on the surface of the glass-like coat layer 11 by dissolving them in a solvent capable of dissolving them. (hereinafter sometimes abbreviated as betaine structure agent) is applied.

When the betaine structure agent is applied and left to stand still, as shown in FIG. 7, the alkoxy groups of the silane moieties of the betaine structure are hydrolyzed by moisture in the air, and the silane moieties of the betaine structure undergo condensation polymerization. , condensed with the OH group protruding from the glass-like coat layer 11 to form a siloxane bond. Thus, the glass-like coat layer 11 and the betaine structure layer 12 are chemically bonded. Silver ions are also contained in the betaine structure layer 12 .

(1-3. Action and effect)
According to the first embodiment, the solvent containing tetraalkoxysilane and the solvent containing the etching component of the resin is applied to the surface of the resin. is formed on the surface of the resin layer, and the tetraalkoxysilane is hydrolyzed and condensation polymerized to form a glass-like coat layer composed of silicon and oxygen. Glued.

Furthermore, in the first embodiment, since the solvent containing the betaine structure is applied to the glass-like coat layer, the silane portion of the betaine structure is hydrolyzed and condensation polymerized to form the betaine structure layer. At the same time, it also condenses with the OH group of the glass-like coat layer to form a siloxane bond.

In this way, the resin layer and the glass-like coat layer are physically bonded by the anchor effect, and the glass-like coat layer and the betaine structure layer are chemically bonded by the siloxane bond, so that the adhesion between the three is remarkably improved. It has the effect of improving to

Furthermore, since silver ions are contained in the glass-like coat layer and the betaine structure layer, the hydrophilic antifouling coat can exhibit antibacterial properties.

2. Second embodiment: One-liquid lamination of antifouling layer (glass-like coat portion and betaine structure portion) (2-1. Configuration)
FIG. 2 shows an antifouling coating structure 2 according to a second embodiment of the present invention. 8 and 9 show chemical states when forming each layer of the antifouling coating structure 2. FIG. Reference numeral 20 in FIG. 2(c) is the same resin base material as in the first embodiment.

A portion corresponding to the glass-like coat layer 11 and a portion corresponding to the betaine structure layer 12 in the first embodiment are formed on the resin base material 20 which has been etched to form nano-order fine unevenness on the surface. The antifouling layer 21 formed inside is laminated. The antifouling layer 21 is formed by one-liquid lamination and does not have a clear interface, but is separated into a glass-like coat portion and a betaine structure portion. The glass-like coating portion existing on the lower side of the antifouling layer 21 enters into minute recesses on the surface of the resin base material 20, and the two are physically bonded together by an anchor effect. Silver ions are contained throughout the antifouling layer 21 .

In the antifouling layer 21, the OH groups derived from the glass-like coat portion and the OH groups derived from the silane portion of the betaine structure are condensed and chemically bonded by siloxane bonds (Si—O—Si). .

As shown in FIG. 9, the betaine structure portion is oriented on the surface (upper side) of the antifouling layer 21, and is polarized into positive charges on the nitrogen atoms and negative charges on the oxygen atoms. show. As a result, it exerts an antifouling property capable of washing off the stains by washing with water against the adhesion of stains and the generation of stains due to staining components.

(2-2. Forming process)
Next, the process of forming the antifouling coating structure of the second embodiment will be described. As shown in FIG. 2(a), a base material 20 made of resin, which is a housing for a surveying instrument, an ophthalmic instrument, or the like, is prepared. The surface of the resin base material 20 is illustrated in a smooth state.

Subsequently, as shown in FIG. 2B, a silver compound, a tetraalkoxysilane, a component capable of dissolving the resin substrate 20, a betaine structure, and, if necessary, other and a solvent in which these additives are dissolved (hereinafter sometimes abbreviated as a one-component antifouling coating agent) are applied.

After the one-component antifouling coating agent is applied, when it is allowed to stand still, a component (etching component) capable of dissolving the resin base material 20 dissolved in the solvent corrodes the surface of the resin base material 20, as shown in FIG. 2(c). As shown in , nano-order fine unevenness is formed on the surface of the resin base material 20 .

At this time, as shown in FIGS. 8 and 9, the alkoxy groups of the tetraalkoxysilane are hydrolyzed by atmospheric moisture and undergo condensation polymerization to form a glass-like network, and at the same time, the silane of the betaine structure Moisture in the atmosphere hydrolyzes the alkoxy groups of the moieties to cause condensation polymerization between the silane moieties of the betaine structure, and the OH groups derived from the glass-like coat moieties and the OH groups derived from the silane moieties of the betaine structure condense. form a siloxane bond. In addition, silver ions are contained throughout the antifouling layer 21 .

Thus, the antifouling layer 21 is formed in a state where the glass-like coat portion and the betaine structure portion are separated in the antifouling layer 21 and chemically bonded to each other by siloxane bonds. As shown in FIGS. 2(c) and 8, the glass-like coating portion of the antifouling layer 21 hardens in a state of entering the minute recesses of the resin substrate 20, and is physically adhered by the anchor effect.

As for the mechanism by which the glass-like coat portion and the betaine structure portion separate vertically inside the antifouling layer 21, which is a single layer, the solubility parameter changes as the solvent evaporates, and one of the components that cannot be completely dissolved takes precedence. and that the betaine structure portion has a low surface energy and preferentially precipitates on the surface side (upper side).

(2-3. Action and effect)
According to the present invention, in the second embodiment, the tetraalkoxysilane, the etching component of the resin, and the solvent containing the betaine structure are applied to the surface of the resin. Fine irregularities of an order are formed on the surface of the resin layer, and the tetraalkoxysilane is hydrolyzed and condensation polymerized to form a glass-like coat portion composed of silicon and oxygen, which forms the fine irregularities of the resin layer. physically attached through At the same time, the silane portion of the betaine structure is hydrolyzed and condensation polymerized to form a betaine structure portion, and condensed with the OH group of the glass-like coat portion to form a siloxane bond. It should be noted that this has a higher hardness than, for example, the case where a resin and an OH group are condensed as disclosed in the above-mentioned Patent Document 4, and unlike the paint of Patent Document 4, the durability of the surface is high.

In this way, the resin layer and the antifouling layer are physically adhered, and the glass-like coating part and the betaine structure part are chemically bonded in the antifouling layer, so the adhesion between the two layers is greatly improved. do. As a result, the hydrophilic antifouling properties of the betaine structure portion protruding to the outermost surface can be exhibited for a long period of time, and the antifouling properties of surveying instruments used in harsh environments can be improved.

Furthermore, since silver ions are contained in the antifouling layer, the hydrophilic antifouling coat can exhibit antibacterial properties.

(First and Second Embodiments: Summary, Other Modifications)
The first and second embodiments are particularly effective for resins that have few OH groups on the surface unlike metals, glass, etc., are difficult to activate on the surface, and are difficult to apply hydrophilic coating directly. is. Although such a resin is not particularly limited, ABS, which is often used for housings of surveying instruments and other measuring instruments, is particularly preferable.

In the first and second embodiments, when the base material is rich in OH groups such as metal or glass, the etching component is not necessary, and the OH groups of the glass-like coat layer condense with the OH groups of the base material. chemically bond with each other.

The glass-like coat layer in the first embodiment of the present invention is preferably formed with a thickness of several hundred μm or less. The reason is that cracks are more likely to occur as the thickness increases.

The betaine structure layer in the first embodiment of the present invention preferably has a thickness of several nanometers to several tens of nanometers.

The antifouling layer in the second embodiment of the present invention is formed by blending both materials and applying them at once so that the glass-like coat layer and the betaine structure layer have a thickness in the same range as in the first embodiment. is preferred.

As the alkoxysilane contained in the glass-like coating agent and the one-component antifouling coating agent of the present invention, 4-, 3-, and 2-functional ones are selected in order to form a network of siloxane bonds in all bonding directions of silicon. , tetra/tri/dimethoxysilane, tetra/tri/diethoxysilane, tetra/tri/dipropoxysilane. The concentration range in the solvent is 50-99% in the first embodiment and 80-99% in the second embodiment.

As shown in FIG. 3, the betaine structure contained in the betaine structure agent and the one-component antifouling coating agent of the present invention has a betaine structure portion that exerts hydrophilic antifouling performance in one bonding direction of silicon. , is required to have three alkoxy groups in order to form a network of siloxane bonds in the remaining three bond directions.

Examples of betaine constituting the betaine structural moiety include common names such as glycochol betaine, α-alllein, loramine AMB-13, rubrin C, abromine, glycylbetaine, trimethylglycol, oxyneurin, oxyneurin, glycine betaine, and lysine. , trimethylglycine and the like. In addition, the systematic names are 2-(trimethylamino)acetate anion, N,N-dimethyl-N-(carboxylatomethyl)methanaminium, trimethylaminoacetate, N,N,N-trimethylaminoacetate , carboxylatomethyltrimethylaminium, carboxylato-N,N,N-trimethylmethanaminium, N,N,N-trimethylcarboxylatomethanaminium, (carboxylatomethyl)trimethylaminium, N,N-dimethyl- N-carboxylatomethylmethanaminium, α-carboxylato-N,N,N-trimethylmethanaminium, 2-oxo-2-oxilato-N,N,N-trimethylmethanaminium, N,N,N- trimethyl-2-oxilato-2-oxoethaneminium, (trimethylamino)acetate anion, (trimethylamino)acetate, carboxylatomethyltrimethylammonium, (2-oxo-2-oxilatoethyl)trimethylaminium, N -(meth)acryloyloxyethyl-N,N-dimethylammonium-α-N-methylcarboxybetaine, N-(meth)acryloyloxypropyl-N,N-dimethylammonium-α-N-methylcarboxybetaine, N-( meth)acryloylamidoethyl-N,N-dimethylammonium-α-N-methylcarboxybetaine, N-(meth)acryloylamidopropyl-N,N-dimethylammonium-α-N-methylcarboxybetaine and the like.

The alkoxy group of the functional group is preferably a methoxy group, an ethoxy group, or a propoxy group.

The silver compound used as an antibacterial agent in the present invention includes a compound that serves as a source of monovalent silver ions (Ag ⁺ ), and specifically includes silver nitrate, silver chloride, silver sulfide, silver sulfate, etc. Among them, silver nitrate is preferred.

The silver compound is mixed with the glass-like coating agent, the betaine structure agent, and the one-component antifouling agent in consideration of the volatilizing solvent so that the content in the antifouling layer after drying is the desired content. The silver ion concentration is 1 mass % or more in the solvent. If it is less than 1% by mass, the antibacterial properties are lowered. Although anions (nitrate ions, etc.) paired with silver ions are omitted in the drawing, anions are actually dispersed together with silver ions.

In addition, although silver (Ag) is preferable as an ion that exerts antibacterial properties, copper (Cu), gold (Au), lead (Pb), platinum (Pt), nickel (Ni), aluminum ( Al), tin (Sn), zinc (Zn) and iron (Fe).

In the present invention, the glass-like coating agent, betaine structure agent, and antifouling coating agent can be applied by known coating methods, dipping methods, vacuum deposition methods, sputtering methods, chemical deposition methods, and the like. The wet method is preferred because of the need to apply the coating to the entire surface of the housing and the cost.

3. Third embodiment: One-liquid lamination of antifouling layer (paint part and betaine structure part) (3-1. Configuration)
10 and 11 show the chemical state when forming each layer of the antifouling coating structure 3 according to the third embodiment of the present invention. In this embodiment, the reference numeral 30 in FIG. 11 can be a resin base material as in the first embodiment, and the reference numeral 30 is a die-cast structure, and the paint and the betaine structure portion are directly applied to these base materials. An antifouling layer can also be provided by one-liquid coating.

In this embodiment, unlike the first and second embodiments, a glass-like coating layer is not provided, and a silver compound and a betaine structure are mixed in a coating material when coating a resin or die-cast housing, It is characterized by forming a paint and a hydrophilic antifouling coat by one-liquid coating.

As shown in FIG. 11, on a substrate 30 made of resin or die-cast, an antifouling layer 31 having a coating resin portion and a betaine structure portion formed in one layer is laminated. The antifouling layer 31 is formed by one-liquid lamination and does not have a clear interface, but is separated into a paint resin portion and a betaine structure portion. The hydrogen atoms of the OH groups of the betaine structure portion are hydrogen-bonded to the oxygen atoms of the paint resin portion, and the paint resin portion and the betaine structure portion are thereby adhered. In addition, silver ions are contained throughout the antifouling layer 21 .

For the coating resin portion present on the lower side of the antifouling layer 31, one having good adhesion to the surface of the substrate 30 is selected. Although a polyester resin is exemplified in FIG. 11, it is not limited to this, and any known coating resin can be selected as long as it can hydrogen-bond with the betaine structure portion to form the antifouling layer 31 .

A betaine structure portion is oriented on the surface (upper side) of the antifouling layer 31 and is polarized into positive charges on nitrogen atoms and negative charges on oxygen atoms, showing hydrophilicity. As a result, it exerts an antifouling property capable of washing off the stains by washing with water against the adhesion of stains and the generation of stains due to staining components.

(3-2. Forming process)
Next, the formation process of the antifouling coat structure of 3rd Embodiment is demonstrated. As shown in FIG. 10, a mixture of a silver compound, a betaine structure having a betaine structure portion and a trialkoxysilane portion, and a polyester resin component is prepared, and if necessary, other additives and a soluble It is used as a solvent (one-component antifouling coating paint) dissolved in a solvent. Subsequently, this solvent is applied to the surface of the base material 30 . If there is a problem with the adhesion between the base material and the coating resin, it is possible to incorporate an etching component in the base material to form microscopic unevenness in the base material and physically adhere to the coating resin. is similar to

When the one-component antifouling coating paint is applied and allowed to stand still, as shown in FIG. It is hydrolyzed by atmospheric moisture to form hydroxyl groups, forming hydrogen bonds with the polyester resin.

In this way, the polyester resin portion, which is the coating resin layer, and the betaine structure portion, which is the hydrophilic coating, are separated in the antifouling layer 31 and bonded to each other by hydrogen bonding to form the antifouling layer 31. be done. In addition, silver ions are contained throughout the antifouling layer 31 .

As for the mechanism by which the polyester resin portion and the betaine structure portion separate vertically inside the antifouling layer 31, which is a single layer, the solubility parameter changes as the solvent evaporates, and one of the components that cannot be completely dissolved is given priority. This is explained by the fact that the betaine structure portion has a low surface energy and preferentially precipitates on the surface side (upper side).

(3-3. Action and effect)
According to the present embodiment, the polyester resin, which is the coating component, and the solvent containing the betaine structure are applied to the substrate surface, so that the polyester coating resin is applied to the substrate and the silane of the betaine structure The moieties can be hydrolyzed to form hydroxyl groups and betaine structure moieties can be formed on the surface of the polyester resin moieties.

Thus, by adding the betaine structure to the coating resin that has conventionally been applied to the base material, it is possible to simultaneously form a coating on the base material and a hydrophilic antifouling coating formed thereon.

A hydrophilic antifouling coating similar to that of the present embodiment can also be formed by two-liquid lamination in which a betaine structure is applied to a finished product having a substrate surface coated with a paint such as a polyester resin.

Furthermore, since silver ions are contained in the antifouling layer, the hydrophilic antifouling coat can exhibit antibacterial properties.

4. Fourth Embodiment: Two-liquid lamination of glass-like coat layer and betaine structure layer (4-1. Structure)
12 to 16 show the chemical state when forming each layer of the hydrophilic antifouling coating structure 4 according to the fourth embodiment of the present invention.

As shown in FIG. 16, a glass-like coat layer 41 mainly composed of silicon and oxygen is laminated on the substrate 40 . The glass-like coat layer 41 enters into fine recesses on the surface of the substrate 40, and the two are physically bonded together by an anchor effect.

A betaine structure layer 42 is laminated on the glass-like coat layer 41 . In both layers, the OH groups present on the surface of the glass-like coat layer 41 and the OH groups present on the surface (lower side) of the betaine structure layer 42 are condensed and chemically formed by siloxane bonds (Si—O—Si). It is in a combined state.

Silver ions are contained in the glass-like coat layer 41 and the betaine structure layer 42 .

(4-2. Forming process)
Next, the formation process of the hydrophilic coat structure of the fourth embodiment will be described. In this embodiment, in order to form the glass-like coat layer 41, as shown in FIG. 12, a solvent containing two kinds of tetraalkoxysilanes is used. One of the two types is one in which one of the four alkoxy groups of the tetraalkoxysilane is OR ₁ and the remaining three are OR ₂ (Si(OR ₁ )(OR ₂ ) ₃ ), and four are all the same OR ₂ is (Si(OR ₂ ) ₄ ). Here, OR ₁ and OR ₂ are not limited as long as they are a combination in which the hydrolysis rate is OR ₁ <OR _2. For example, if OR ₁ is a methoxy group, OR ₂ is an ethoxy group or a propoxy group. is selected.

When a solvent containing these Si(OR ₁ )(OR ₂ ) ₃ and Si(OR ₂ ) ₄ is applied to the resin substrate 40 , the hydrolysis rate of OR ₂ is higher than that of Si(OR ₂ ) ₄ . All alkoxy groups are hydrolyzed to OH groups, and Si(OR ₁ )(OR ₂ ) ₃ has three alkoxy groups hydrolyzed to OH groups, leaving OR ₁ . Then, the OH group undergoes dehydration condensation to form a glass-like coat layer 41 having _one OR group protruding from the surface as shown in FIG.

Subsequently, OR ₁ , which has a low hydrolysis rate, is also hydrolyzed with delay to form OH groups, forming a glass-like coat layer 41 having OH groups protruding from the surface as shown in FIG.

Further, in this embodiment, as in the first and second embodiments, the substrate 40 is made to contain an etching component to form microscopic unevenness in the substrate 40, and is physically adhered to the glass-like coat layer 41. is shown in the drawing, if the base material is rich in OH groups such as metal or glass, it is chemically bonded by dehydration condensation with the OH groups of the glass-like coat layer 41 .

Thereafter, as shown in FIG. 15, a solvent containing a betaine structure is applied onto the glass-like coat layer 41 to hydrolyze and dehydrate the betaine structure, and a betaine structure layer 42 is formed as shown in FIG. to form Since this process is the same as in the first embodiment, the description is omitted.

(4-3. Action and effect)
According to the fourth embodiment, as described in the first and second embodiments, the glass-like coat layer made of silicon and oxygen is physically adhered via the fine irregularities of the substrate, and the betaine structure layer is It also condenses with the OH group of the glass-like coat layer to form a siloxane bond. In this way, the base material and the glass-like coat layer are physically bonded by the anchor effect, and the glass-like coat layer and the betaine structure layer are chemically bonded by the siloxane bond, so that the adhesion between the three is remarkably improved. It has the effect of improving to

Furthermore, since silver ions are contained in the antifouling layer, the hydrophilic antifouling coat can exhibit antibacterial properties.

In this embodiment, in addition to the above, two kinds of tetraalkoxysilanes are mixed to form a glass-like coat layer, so that _one OR group having a relatively low hydrolysis rate is oriented in a specific direction. Projection to the outermost surface occurs preferentially. The OH group generated by hydrolysis of this OR ₁ group is similarly oriented and protrudes to the outermost surface. By doing so, when one type of alkoxysilane is used, the orientation direction is various, such as when the OH group protrudes to the surface and when it is buried and does not protrude. can be made to protrude in a specific orientation direction more reliably, and the adhesiveness to the subsequently formed betaine structure layer is improved.

(5. Concrete example)
As a specific example of a surveying instrument to which the hydrophilic antifouling coating structure of the present invention is applied, a laser irradiation device 100 is shown in FIGS. 18 and 19 and will be described.

A main body 101 of the laser irradiation device 100 has a cylindrical shape, and the main body 101 is supported by four supporting legs 110 . The body portion 101 has a laser oscillation device (not shown) provided inside a cylindrical housing 102 so as to be capable of swinging in two directions, ie, the vertical direction and the horizontal direction. is configured to irradiate a laser beam to the

A light projecting window 103 covered with glass is provided on the front surface of the main body 101, and the laser beam from the laser oscillator is irradiated through the light projecting window 103. As shown in FIG.

A light-receiving window 104 is provided above the light-projecting window 103, and receives a laser beam reflected from the target through the light-receiving window 104, and also receives operation signal light for remote control.

A front leg 105 is provided on the front surface of the main body 101, and the laser irradiation device 100 can be installed upright via the front leg 105. As shown in FIG.

A laser protection cover 106 is provided on the upper surface of the main body 101 . The rear portion of the body portion 101 is inclined, and the inclined surface also serves as an operation panel 121. The operation panel 121 is provided with various operation switches 122, a display portion 130, a bubble tube 123, and the light receiving window 104. A light-receiving window 124 is provided for receiving a remote control operation signal in a similar manner. Since the light-receiving window 124 is provided on the inclined operation panel 121, it can be remotely operated by a remote controller from both horizontal and vertical directions. It can be operated remotely. Further, since the display unit 130 is provided on the slanted operation panel 121, the display contents can be confirmed from above.

The main body 101 has a die-cast structure, and conventionally, the surface of the die-cast structure is coated with paint (only for decoration) to form a final product. On the other hand, in the present invention, the hydrophilic antifouling coat may be applied on the paint as described in the first, second and fourth embodiments.

Alternatively, when applying a hydrophilic paint directly to an unpainted die-cast structure, if it is an organic paint, follow the third embodiment and apply the betaine structure of the present invention to the organic paint to be painted. A hydrophilizing agent containing a body may be mixed. In the case of an inorganic coating, in addition to the method of mixing the hydrophilic agent containing the betaine structure of the present invention with the inorganic coating in the same manner as in the third embodiment, it can also be applied to the glass-like coating layer. good.

As described above, the form of applying the hydrophilic antifouling coating of the present invention on top of the conventional coating and the form of applying the paint and the hydrophilic antifouling coating in a mixture have been described. It does not necessarily have to be applied, and these forms can be combined part by part. For both die casting and resin parts, it is preferable to carry out spray coating in consideration of mass production efficiency and cost.

The inclined surfaces other than the operation panel 121 and the front surface of the main body 101 other than the light projection windows 103 and 104 are made of plastic parts, and are directly coated with the hydrophilic antifouling coating of the present invention without coating. .

The operation panel 121 is coated with a hydrophilic antifouling film (for example, PET or the like), and the hydrophilic antifouling coating is applied on the film.

An antireflection film is applied to the glass of the light projecting window 103 and the light projecting window 104, and a hydrophilic antifouling coat is applied on the antireflection film. This hydrophilic antifouling coat has a monomolecular structure, and is composed of organic or inorganic monomolecules, or the resin itself is hydrophilic.

That is, "(1) inorganic type (glass type)" is mentioned, in which a hydroxyl group exists in the Si atom in the molecular chain of the siloxane bond, and the hydroxyl group crosslinks between a plurality of molecular chains to form a network. Alternatively, "(2) organic (water-soluble polymer, polyester, etc.)" may be mentioned, in which case hydroxyl groups are present in the carbon chain and are crosslinked by UV irradiation and heating to form a network. In either case, a three-dimensional crosslinked structure is formed to cure the coating film, thereby improving water resistance.

EXAMPLES The present invention will now be described in more detail with reference to examples and comparative examples.
(Example 1, Comparative Example 1)
Since some products of surveying instruments are installed and used in sewage pipes, sewage filth or the like adheres to their housings, making them dirty. In order to reproduce the situation, sewage filth was applied to the surface of the surveying instrument housing of Example 1 and Comparative Example 1, and after drying, the sewage filth was flushed with water, and the appearance after peeling was observed. In Example 1, the hydrophilic antifouling coating structure of the first embodiment of the present invention was adopted for the surface of the housing of the surveying instrument, which is a glass-like coating. The concentration of silver ions in the coating agent solution was 1 mass %, and the compound used was silver nitrate. In Comparative Example 1, the surface remained uncoated with a glass-like coating.

Specifically, as shown in FIG. 17(a), the left half of the surface of one surveying instrument (pipe laser) is coated with the hydrophilic antifouling coating of Example 1, and the right half is coated with the glass-like coating of Comparative Example 1. , adhered sewage. After drying the sewage dirt, it was washed with water as shown in FIG. 17(b).

When water was sprayed onto the part of the device to which the hydrophilic antifouling coating of the example was applied, sewage filth was separated and flowed. Thus, the dirt was easily removed, and as shown in FIG. 17(b), no trace was left. On the other hand, in the comparative example, dirt adhered strongly and had to be wiped off by hand. Moreover, as shown in FIG. 17(b), traces of peeling of dirt remained on the surface, and a foul odor remained.

Even if the hydrophilic antifouling coating is applied, there is a possibility that the offensive odor will remain. Therefore, it is possible to add perfume to the hydrophilic antifouling coating.

In this embodiment, the hydrophilic antifouling coating was applied only to the main body of the resin-made surveying instrument, but the same effect can be obtained by applying the hydrophilic antifouling coating to glass members such as prisms and reflecting mirrors used in surveying work. rice field.

(Examples 2 and 3, Comparative Examples 2 and 3)
Next, the test pieces of Examples 2 and 3, which adopted the hydrophilic antifouling coating structure of the first embodiment in which the antifouling layer was formed by applying a solvent having a silver ion concentration of 1% by mass of the present invention, and silver ions. Test pieces of Comparative Examples 2 and 3 were prepared, which employs the same coating structure as the hydrophilic antifouling coating structure of the first embodiment except that it does not contain. The test conditions were based on the standards of the film adhesion method of the Antimicrobial Product Technology Council.

Based on the above specifications, the test pieces of Example 2 and Comparative Example 2 were inoculated with Staphylococcus aureus, and the test pieces of Example 3 and Comparative Example 3 were inoculated with E. coli, respectively, immediately after inoculation and after holding at 35 ° C. for 24 hours. The number of viable bacteria per test piece was measured. This operation was performed three times, and the average values are shown in Table 1.

As shown in Table 1, in the test piece of the example, the bacteria almost disappeared, whereas in the test piece of the comparative example, the number of bacteria was slightly more than halved.

By demonstrating the hydrophilic antifouling properties of the betaine structure part protruding from the outermost surface of the hydrophilic antifouling coating layer over a long period of time, it is possible to improve the durability of the antifouling performance of surveying instruments used in harsh environments. In addition, it can exhibit antibacterial properties against harmful bacteria.

1: Hydrophilic antifouling coating structure 10: Base material (resin base material)
11: Glass-like coating layer 12: Betaine structure layer 2: Hydrophilic antifouling coating structure 20: Base material (resin base material)
21: Antifouling layer formed by one-liquid lamination (glass-like coat part + betaine structure part)
3: Hydrophilic antifouling coating structure 30: Base material 31: Antifouling layer formed by one-liquid lamination (paint resin part + betaine structure part)
4: Hydrophilic antifouling coating structure 40: Base material 41: Glass-like coating layer 42: Betaine structure layer 100: Laser irradiation device 101: Main unit 110: Support leg 102: Cylindrical housing 103: Light projection window 104: Light receiving window 105: Front leg 106: Laser protection cover 121: Operation panel 122: Various operation switches 123: Bubble tube 124: Light receiving window 130: Display unit

Claims (2)

a substrate layer;
a glass-like coat layer provided on the base material layer;
A betaine structure layer comprising a betaine portion and a silane portion provided on the glass-like coat layer,
A method for forming a hydrophilic antifouling coating structure in which the glass-like coating layer and the betaine structure layer contain 1% by mass or more of silver ions,
applying a solvent containing 1% by mass or more of silver ions and tetraalkoxysilane to the surface of the substrate layer;
Hydrolyzing the alkoxysilane to form a glass-like coat layer containing silver ions on the base layer,
applying a solvent containing 1% by mass or more of silver ions and a betaine structure composed of a betaine moiety and an alkoxysilane moiety to the glass-like coat layer;
Hydrolyzing the alkoxysilane portion of the betaine structure to form a betaine structure layer containing silver ions on the glass-like coat layer,
A method for forming a hydrophilic antifouling coating structure, wherein the solvent containing the tetraalkoxysilane contains a tetraalkoxysilane in which all four functional groups are the same and a tetraalkoxysilane in which one functional group is different. 2. The method of forming a hydrophilic antifouling coating structure according to claim 1, wherein the base material layer is a resin layer, and the solvent containing the tetraalkoxysilane contains an etching component for the resin layer.

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