JP2023093935A - Manufacturing method of coating film, and composition for forming two-pack coating film - Google Patents

Abstract

To provide a manufacturing method of a coating film and a composition for forming a coating film, with which high water repellency and water sliding property, and a low friction property are exhibited, and in which these effects are hardly lost even when wiping is repeated.SOLUTION: A manufacturing method of a coating film includes: a step 1 for coating a substrate with a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent in order to form a porous coating film on the substrate; and a step 2 for coating a coating liquid 2 containing a siloxane compound and a solvent on the porous coating film. Further, a composition for forming a two-pack coating film contains the coating liquid 1 and the coating liquid 2.SELECTED DRAWING: None

Description

The present invention relates to a method for producing coatings. More specifically, using a coating liquid 1 to be applied on the substrate and a coating liquid 2 to be applied on the porous film on the substrate formed by the coating liquid 1, wipe durability on the substrate. It relates to a method for producing superior coatings. The present invention also relates to a two-liquid type film-forming composition containing coating liquid 1 and coating liquid 2 .

BACKGROUND ART Conventionally, a large number of coating agents for protecting the appearance of vehicles such as automobiles and trains, aircraft, building materials, wall materials, general industrial equipment, and road signs have been provided. Particularly for vehicles, glass-based coating compositions comprising polysilazane and silane compounds have been provided for the purpose of imparting protection and gloss to coatings. For example, Patent Document 1 describes an organic polysilazane having a water contact angle of 70 degrees or more when formed into a film, a curing catalyst, and a reactive silicone oil having at least one reactive functional group in the molecule. Coating agents for imparting luster, luster, water repellency, and antifouling properties to metal surfaces, painted surfaces, resin surfaces, etc. of various industrial products are described. Further, Patent Document 2 discloses that polysilazane having a specific main skeleton, modified silicone oil and/or curable silicone resin are contained, and the modified silicone oil is amino-modified silicone, epoxy-modified silicone, carbinol-modified silicone, or the like. It is at least one selected, and the curable silicone oil is characterized by having a specific average composition formula. Coatings are described for imparting long-term stain resistance, gloss, and water repellency.

JP 2014-139301 A JP 2012-153849 A

As described above, it has been conventionally reported that coating agents containing silicon-containing compounds such as polysilazane and silicone oil are used to impart water repellency and antifouling properties to painted surfaces of vehicles. However, the durability of the films obtained from these coating agents, particularly the durability (durability of effects such as water repellency) upon repeated washing and wiping during car washing, etc., is not sufficient.

INDUSTRIAL APPLICABILITY The present invention can be applied to substrates such as painted surfaces of vehicles, exhibits high water repellency, water sliding properties, and low friction properties, and these effects are lost even after repeated wiping. An object of the present invention is to provide a method for producing a film and a composition for forming a film, which are difficult to obtain.

As a result of intensive studies conducted by the present inventors with respect to the above object, the composition for forming a film was made into a two-liquid type (a method in which two types of coating liquids are prepared and these are applied in order), and the substrate is first A silazane compound, an alkoxysilane compound, a catalyst, and a solvent are used as the coating liquid 1 to be applied. And by applying a solvent-containing one, it is possible to exhibit high water repellency, water slipperiness, and low friction, and these effects are unlikely to be lost even after repeated wiping (i.e., wiping durability It has been found that a coating is obtained which has the advantage of being highly flexible.

The present invention includes, but is not limited to, the following.
(1) Step 1 of applying a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent to a substrate to form a porous coating on the substrate;
A method for producing a film, comprising a step 2 of applying a coating liquid 2 containing a siloxane compound and a solvent onto the porous film.
(2) The method according to (1), wherein the catalyst in the coating liquid 1 is a silicone oil having an amino group.
(3) The method according to (1) or (2), wherein the alkoxysilane compound in the coating liquid 1 is an alkoxysilane oligomer having an alkoxysilyl group.
(4) The method according to any one of (1) to (3), wherein the siloxane compound in the coating liquid 2 is a silicone oil having a silanol group.
(5) The method according to any one of (1) to (4), wherein the silazane compound in the coating liquid 1 is polysilazane.
(6) The method according to any one of (1) to (5), wherein the solvent in the coating liquid 2 is dimethylsilicone oil.
(7) Any one of (1) to (6), wherein the mixing ratio of the siloxane compound and the solvent in the coating liquid 2 is 0.1:99.9 to 10.0:90.0 in mass ratio. The method according to item 1.
(8) The method according to any one of (1) to (7), wherein the substrate is a painted surface of a vehicle body.
(9) The method according to any one of (1) to (8), wherein steps 1 and 2 are performed at room temperature.
(10) a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent;
A two-component film-forming composition containing a siloxane compound and a coating liquid 2 containing a solvent.
(11) a coating liquid 1 containing polysilazane, an alkoxysilane oligomer having an alkoxysilyl group, a silicone oil having an amino group, and a solvent;
A two-component film-forming composition containing a silicone oil having a silanol group and a coating liquid 2 containing a dimethylsilicone oil.

The method for producing a film and the two-component film-forming composition of the present invention exhibit high water repellency, water slipperiness, and low friction, and these effects are not easily lost even after repeated wiping. (That is, a coating with high wiping durability) can be produced. For example, when a film is formed on an automobile body and painted surface using the method and composition of the present invention, the effect of repelling rainwater and water droplets can be obtained due to the high water repellency of the film. In addition, water droplets can be prevented from sticking due to the high water sliding property of the coating. In addition, since the friction of the coating surface is small, there is an advantage that the coating is less likely to be scratched during car washing or wiping. In addition, even after repeated wiping, the effects of high water repellency, water slipperiness, and low friction are unlikely to be lost, and the above effects can be enjoyed over a long period of time.

The present invention comprises a step 1 of applying a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent to a substrate to form a porous coating on the substrate; and a step 2 of applying a coating liquid 2 onto the porous film. The present invention also relates to a two-liquid type film-forming composition containing the coating liquid 1 and the coating liquid 2 described above.

<Step 1 of applying coating liquid 1>
In the method of the present invention, first, coating liquid 1 is applied onto a substrate to form a porous coating.

Coating liquid 1 contains a silazane compound, an alkoxysilane compound, a catalyst, and a solvent. When the coating liquid 1 has such a composition, it becomes possible to form an inorganic porous film at room temperature.

A silazane compound is a general term for substances having a silazane bond --Si--N--Si--. The silazane compound serves to ensure adhesion to the substrate surface and at the same time to form a film having a vitreous skeleton. Examples of silazane compounds include polysilazanes, and in the present invention, both inorganic polysilazanes such as perhydropolysilazane and organic polysilazanes such as methylhydropolysilazane and dimethylpolysilazane can be used. Moreover, you may use these in combination. Among these, inorganic polysilazane is preferred, and perhydropolysilazane is more preferred.

Since the coating liquid 1 contains a silazane compound, a film having a hard vitreous skeleton is formed at room temperature. A silazane bond in a silazane compound reacts with moisture in the air, and nitrogen atoms are discharged as ammonia, and converted into a siloxane bond -Si-O-Si- (silica conversion). Polysilazane is usually a viscous liquid with a weight average molecular weight of several thousand (for example, about 1000 to 3000), but it can be converted into a hard vitreous substance by conversion to silica.

Silica conversion is accelerated by heating, but can be accelerated by a catalyst even at room temperature. In the present invention, the coating liquid 1 contains a catalyst in addition to the silazane compound, thereby making it possible to form a film at room temperature.

As the catalyst, it is preferable to use a catalyst having an amino group. The presence of an amino group in the reaction system provides a catalytic action that promotes curing of the silazane compound. Rapid silica conversion can be achieved by catalytic action. Further, the catalyst is more preferably a silicone oil having an amino group, and more preferably a silicone oil modified with an amino group at least at a side chain or one end, preferably both ends. When the catalyst is a silicone oil having an amino group, the advantage of improved wiping durability is obtained. Although the reason for this is not clear, when a silicone oil having an amino group is used as a catalyst, the coating liquid 2 becomes elastic when the coating liquid 2 is applied due to its high compatibility with the siloxane compound contained in the coating liquid 2. It is speculated that it will become difficult to peel off and that it will become easier to penetrate into the inside of the voids. Among the catalysts having an amino group, organic amines are not preferred because they remain as foreign matter in the vitreous skeleton and can become starting points for fracture.

Coating liquid 1 also contains an alkoxysilane compound. An alkoxysilane compound is a general term for silane compounds having an alkoxy group. The alkoxysilane compound ensures adhesion to the base material and at the same time plays a part of the role of forming the vitreous skeleton of the coating. Since the vitreous skeleton formed by the alkoxysilane compound alone has a lower density than the vitreous skeleton formed by the silazane compound alone, the resistance to friction is somewhat low. By mixing the alkoxysilane compound and the silazane compound, it is possible to form a film having moderate flexibility and abrasion resistance that cannot be obtained with the silazane compound or the alkoxysilane compound alone.

The alkoxysilane compound is preferably an alkoxysilane oligomer having an alkoxysilyl group. Examples of the alkoxysilyl group include a methoxysilyl group and an ethoxysilyl group. As the alkoxysilyl group, an alkoxysilane oligomer having only a methoxysilyl group, an oligomer having only an ethoxysilyl group, and a combination of a methoxysilyl group and an ethoxysilyl group Any oligomer that has both can be used. Among these, alkoxysilane oligomers having methoxysilyl groups (methoxysilyl group-containing silane oligomers) are particularly preferred. An alkoxysilane oligomer refers to an oligomer formed by condensation polymerization of an alkoxysilane compound (monomer). Alkoxysilane oligomers have a linking structure due to siloxane bonds, but have a different molecular shape from linear long-chain polysiloxanes such as silicone oil. Therefore, the alkoxysilane oligomer is recognized as a compound different from polysiloxane and silicone oil.

By mixing the alkoxysilane compound with the coating liquid 1, the wiping durability of the coating is improved. The reason why the wiping durability is improved by mixing the alkoxysilane compound is not clear, but it is speculated that the alkoxysilane compound imparts rubber-like viscoelastic behavior and flexibility to the porous coating formed by the coating liquid 1. . The alkoxysilane compound plays the role of a "hand of chemical bonding" that fixes the siloxane compound contained in the coating liquid 2, and also makes the molecular chains of the silazane compound cross-linked to make them stronger, as in the case of rubber vulcanization. It is thought that the role of forming a thin film is also shown.

Coating liquid 1 contains a solvent in addition to the silazane compound, catalyst, and alkoxysilane compound described above. The type of solvent in the coating liquid 1 is not particularly limited, and a solvent having good affinity with the above compound may be appropriately selected from known solvents. For example, petroleum-based solvents (eg, paraffin-based hydrocarbon solvents, naphthenic-based hydrocarbon solvents, etc.) and ether-based solvents (eg, dibutyl ether, etc.) can be used.

The contents of the silazane compound, the alkoxysilane compound, the catalyst, and the solvent in the coating liquid 1 are 0.10 to 1.00 wt% for the silazane compound, 0.05 to 0.30 wt% for the alkoxysilane compound, and 0.001 wt% for the catalyst. About 0.10 wt %, and the remainder is preferably a solvent, 0.20 to 0.60 wt % of a silazane compound, 0.07 to 0.25 wt % of an alkoxysilane compound, and 0.005 to 0.005 wt % of a catalyst. It is more preferable that the content is about 07 wt % and the remainder is the solvent.

The type of substrate to which the coating liquid 1 is applied is not particularly limited, and in general, it is required to have water repellency, water slipperiness, and antifouling properties due to low friction. Surfaces of aircraft bodies and fuselages, building materials and wall materials, general industrial equipment, road signs, and the like can be mentioned. In particular, the painted surface of an automobile body (body) is preferable. It is said that the film formed by the present invention exhibits high water repellency, water slipperiness, and low friction, and these effects are not likely to be lost even after repeated wiping (that is, high wiping durability). have advantages. According to the present invention, when a coating is formed on the coated surface of an automobile body, for example, the coating has high water repellency, so that the effect of repelling rainwater and water droplets can be obtained. In addition, water droplets can be prevented from sticking due to the high water sliding property of the coating. In addition, since the friction of the coating surface is small, there is an advantage that the coating is less likely to be scratched during car washing or wiping. In addition, even after repeated wiping, the effects of high water repellency, water slipperiness, and low friction are unlikely to be lost, and the above effects can be enjoyed over a long period of time.

The method of applying the coating liquid 1 is not particularly limited, and commonly used methods such as sponge coating, dip coating, spin coating, and brush coating can be used. Coating liquid 1 is allowed to stand for about 10 to 30 minutes after application to dry the solvent. After drying the solvent, it is preferable to spread (level) the remaining active ingredient with a dry cloth such as a microfiber cloth (leveling), but the next coating liquid 2 may be applied without spreading. The temperature during application and drying is not particularly limited.

The coating liquid 1 may be applied multiple times to form a thick and strong skeleton coating. For example, after the coating liquid 1 is applied and allowed to stand for a predetermined period of time, the coating liquid 1 may be applied again over the half-dried skeleton coating. Alternatively, two or more types of liquids corresponding to the composition of the coating liquid 1 may be prepared, and the skeletal coating may be formed by coating these liquids one on top of the other.

By applying the coating liquid 1, a porous film is formed on the substrate. Although the mechanism by which the coating liquid 1 forms a porous film is not clear, ammonia as a by-product is generated during the silica conversion, and this foams and evaporates in the coating liquid immediately after it is applied to the substrate. , it is thought that pores are formed in the coated film. That is, it is considered that hardening due to silica conversion and pore formation due to foaming proceed simultaneously to form a porous coating. In addition, since a catalyst is also used in the present invention, the conversion of silica is accelerated, and foaming by ammonia becomes more intense, so it is thought that a porous film having countless dense pores can be obtained.

The film thickness of the porous film obtained by applying the coating liquid 1 is not particularly limited, and is, for example, about 10 nm to 1 μm, for example about 30 to 600 nm, for example about 50 to 200 nm. Sufficient durability can be obtained by having an appropriate thickness of the film, and by having an appropriate thickness, regardless of the surface layer or deep layer of the coating, it can simultaneously and uniformly absorb moisture in the atmosphere. Since there is almost no difference in the internal pressure, the size of the ammonia bubbles generated becomes uniform, and it is thought that regular pores can be obtained.

A porous film formed of a silazane compound alone has low functionality such as water repellency and high frictional resistance, so that a high load is applied during wiping and the wiping durability is low (brittle). In contrast, in the present invention, an alkoxysilane compound and a catalyst are used in combination with a silazane compound (coating liquid 1), and further coating liquid 2, which will be described later, is applied from above to finally wipe off durability. can be obtained.

<Step 2 of applying coating liquid 2>
After applying the coating liquid 1 to form a porous film on the substrate, the coating liquid 2 is applied on the porous film. The coating liquid 2 is applied on the porous film formed by the coating liquid 1, and the functional components contained in the coating liquid 2 are impregnated into the pores of the porous film and/or attached to the inner walls of the pores, Furthermore, by coating the skeleton forming the unevenness of the outermost layer of the film, the above-mentioned film having high wiping durability can be obtained.

Coating liquid 2 contains a siloxane compound and a solvent. A siloxane compound is a general term for compounds having a siloxane bond. The siloxane compound impregnates the inside of the pores of the porous coating with the coating liquid 1 and/or adheres to the inner walls of the pores, thereby playing a role of imparting water repellency and water slipping functionality to the coating. The siloxane compound is preferably a silicone oil having a silanol group, preferably a silicone oil having a silanol group at least at a side chain or one end, preferably at both ends. Since the inner wall of the porous coating formed by the coating liquid 1 has the bonding hands of the alkoxysilane compound and the siloxane skeleton, the siloxane compound of the coating liquid 2 is chemically and physically fine particles in the porous coating. It is thought that it becomes easy to fix in a hole. In addition, as shown in the results of the examples, by applying a mixture of the siloxane compound to the coating liquid 2, compared with the case where only the solvent described later is applied, the effect of improving the wiping durability is also obtained.

As the solvent, it is preferable to use silicone oil having excellent volatility, and it is preferable to use unmodified dimethyl silicone oil. Since the silicone oil used as the solvent has a high affinity with the siloxane skeleton of the porous film formed by the coating liquid 1, when the coating liquid 2 is applied on the porous film, it is not easily repelled, and the functional component (coating It plays the role of allowing the siloxane compound of liquid 2) to penetrate into the pores of the coating.

The mixing ratio of the siloxane compound and the solvent in the coating liquid 2 is preferably about 0.1:99.9 to 10.0:90.0, more preferably 0.5 to 99.5:3. More preferably, it is about 0 to 97.0.

Coating liquid 2 can be immediately overcoated on the porous film formed with coating liquid 1 . The method of applying the coating liquid 2 is not particularly limited, and commonly used methods such as sponge coating, dip coating, spin coating, and brush coating can be used. Coating liquid 2 is preferably allowed to stand for about 10 to 30 minutes after application to dry the solvent, and then the film is wiped off with a water-containing microfiber cloth or the like to remove excess components. The temperature during application and drying is not particularly limited. Coating liquid 2 usually does not need to be applied repeatedly, and may be applied once.

By applying the coating liquid 2 on the porous film formed by the coating liquid 1, high water repellency, water slippage, and low friction can be exhibited, and these effects can be achieved even after repeated wiping. It is possible to form a film that is difficult to lose (that is, has high wiping durability). In the present invention, the siloxane compound contained in the coating liquid 2 exhibits functionality such as water repellency and water slippage, while the porous structure of the coating formed by the coating liquid 1 amplifies the performance. A porous film formed only with the coating liquid 1 does not sufficiently exhibit functionality such as water repellency and low friction. Moreover, the coating liquid 2 alone does not have a film-forming ability and fixability to the substrate. By sequentially coating the coating liquid 1 and the coating liquid 2, these compositions play their respective roles, and high water repellency and water sliding properties, low friction, and high wiping durability can be obtained. Become.

Although the mechanism by which the film produced by the present invention exhibits high water repellency and water slip, low friction, and high wiping durability is not clear, it is speculated as follows:
The porous film of coating liquid 1 has a huge specific surface area, and the siloxane compound in coating liquid 2, which is a water-repellent component, adheres to the inner walls of the voids, so that the lotus effect (water repellency and water sliding) can be obtained. it is conceivable that. In addition, it is considered that the ground contact area of the contacting object is reduced due to the molecular motion of the siloxane compound in the coating liquid 2 and the unevenness of the surface, thereby exhibiting remarkable low friction. In addition, although the skeleton of the porous coating is hard and vitreous, it is thought that the inclusion of the alkoxysilane compound in the coating liquid 1 imparts flexibility/elasticity exhibiting rubber-like viscoelastic behavior. be done. It is thought that the resistance to physical loads is improved due to the load dispersibility due to the porous structure like a sponge material and the excellent elasticity that pushes back the load. In addition, the high water-repellent and water-sliding properties prevent water from entering inside the film, and the low-friction properties reduce the frictional resistance during wiping, resulting in improved wiping durability during washing. it is conceivable that.

<Two-component film-forming composition>
The present invention also provides a two-part film-forming composition, in addition to a method of making the film. A two-component film-forming composition refers to a composition containing at least two types of coating liquids, coating liquid 1 and coating liquid 2 .

Coating liquid 1 and coating liquid 2 are provided in separate containers. The type of container is not particularly limited, and one commonly used for coating agents may be used. Moreover, the coating liquid 1 and the coating liquid 2 may be provided in different containers without being mixed, and the number of each container is not particularly limited. For example, as described above, coating liquid 1 may be overcoated, so if it is intended to apply coating liquid 1 twice and coating liquid 2 once, it is convenient for the user. For this purpose, two containers containing the coating liquid 1 and one container containing the coating liquid 2 may be provided as a set, but the present invention is not limited to this.

As described in Patent Documents 1 and 2, a conventional film-forming composition comprises a component such as polysilazane that forms a film with a vitreous skeleton that serves as a scaffold to be fixed to a substrate, a catalyst that accelerates its curing, Ingredients that demonstrate functionality such as water repellency were all mixed in one liquid. In order to improve the functionality of such a one-liquid type composition, it was necessary to increase the blending ratio of a functional component such as silicone oil. However, increasing the blending ratio of the functional ingredients reduces the ratio of the ingredients for forming the vitreous skeleton. Functional ingredients such as silicone oil do not have the property of curing through a chemical reaction like polysilazane, so films produced from compositions with a low proportion of ingredients for forming a vitreous skeleton are strong. Instead, the whole became fragile. In addition, since polysilazane and silicone oil are different substances and are not completely mixed, partial phase separation occurs, making it difficult to form a uniform film. On the other hand, when the amount of the functional component to be blended is suppressed and the ratio of the component forming the film skeleton is increased, functions such as low friction cannot be sufficiently obtained. If the low-friction properties are lost, a large amount of friction occurs during physical wiping, leading to damage to the coating, resulting in a brittle coating. Thus, with conventional one-liquid coating agents, the key to product development is how to strike a balance between the hard vitreous skeleton and functionality. was dealt with. However, such a method does not make full use of the properties of both the film skeleton-forming component and the functional component, and seeks a compromise in performance between the two.

In addition, many of the functional ingredients used in conventional compositions are silicone compounds, but there are various types of silicone compounds, such as reactive types, non-reactive types, and resins. In order to improve the performance, a combination of reactive resins was often used. Conventional one-liquid glass-based coating agents contain various components in this way, so even if the vitreous skeleton contains functional components, each component aggregates and enlarges. It is thought that it was in a state where it was easy to drop out due to such things as being unevenly distributed. It is also conceivable that the incorporation of the functional component into the inside of the coating skeleton in the course of formation may cause the coating skeleton to have brittle spots. In fact, with the conventional one-liquid type glass-based coating agent, repeated wiping causes a significant decrease in functionality.

On the other hand, in the present invention, the coating liquid is divided into two types, 1 and 2, and by clearly dividing the roles of forming the skeleton and imparting functionality to each, the performance of each is maximized. is. The method for producing a film and the two-component film-forming composition of the present invention can provide higher wiping durability than conventional one-component products.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these.
<Example 1>
Silazane compound (perhydropolysilazane, molecular weight about 2000) 0.40 wt%, alkoxysilane compound (methoxysilyl group-containing silane oligomer, viscosity about 350 cSt) 0.10 wt%, catalyst (both terminal amino group-modified silicone oil) 0.05 wt% , and a solvent of 99.45 wt % (dibutyl ether of 9.45 wt % and an isoparaffinic hydrocarbon solvent (Merveille manufactured by Idemitsu Kosan Co., Ltd.) of 90.00 wt %).

In addition, a siloxane compound (both terminal silanol group-modified silicone oil, viscosity 100 to 200 cSt) 1.0 wt%, and a solvent (dimethyl silicone oil (Shin-Etsu Chemical Co., Ltd. Shin-Etsu Silicone (registered trademark) oil KF-96L)) 99.0 wt% A coating liquid 2 consisting of was prepared.

A 70×150×2 mm black-coated steel plate for automobile bodies was used as a test piece, and the coating liquid 1 was applied to a sponge with microfiber nonwoven fabric. After standing at room temperature for 15 minutes to dry the solvent, the remaining components were spread over a microfiber cloth to form a film derived from coating liquid 1 on the test piece.

Then, the coating liquid 2 was applied on the obtained coating with a sponge with microfiber nonwoven fabric. After standing at normal temperature for 15 minutes, the film was wiped off with a microfiber cloth moistened with water to remove excess components, and a film derived from coating solution 1 and coating solution 2 was formed on the test piece.

<Example 2>
Silazane compound 0.48 wt% (perhydropolysilazane 0.40 wt% and methylhydropolysilazane (molecular weight: about 2000) 0.08 wt% used in Example 1), alkoxysilane compound (methoxysilyl group-containing silane used in Example 1) Oligomer) 0.20 wt%, catalyst (both terminal amino group-modified silicone oil used in Example 1) 0.01 wt%, solvent 99.31 wt% (dibutyl ether 9.50 wt% and isoparaffinic carbonization used in Example 1 A coating liquid 1-1 containing a hydrogen solvent (89.81 wt %) was prepared.

Further, 0.48 wt% of a silazane compound (0.40 wt% of the above perhydropolysilazane and 0.08 wt% of methylhydropolysilazane), 0.10 wt% of an alkoxysilane compound (the above methoxysilyl group-containing silane oligomer), a catalyst (the above A coating liquid 1-2 consisting of 0.05 wt % amino group-modified silicone oil at both ends and 99.37 wt % solvent (9.50 wt % dibutyl ether and 89.87 wt % isoparaffinic hydrocarbon solvent) was prepared.

In addition, siloxane compound A (both terminal silanol group-modified silicone oil used in Example 1) 1.0 wt%, siloxane compound B (both terminal silanol group-modified silicone oil, viscosity 10 to 100 cSt) 0.5 wt%, and solvent ( A coating liquid 2 containing 98.5 wt % of the dimethyl silicone oil used in Example 1 was prepared.

Coating liquid 1-1 was applied onto the test piece in the same manner as in Example 1, and the test piece was allowed to stand at room temperature for 15 minutes to dry the solvent. After standing at room temperature for 15 minutes to dry the solvent, the remaining components were spread with a microfiber cloth to form a film derived from coating solution 1 (1-1 and 1-2) on the test piece.

Then, the coating liquid 2 was applied on the obtained coating with a sponge with microfiber nonwoven fabric. After standing for 15 minutes at room temperature, wipe off the coating with a microfiber cloth wet with water to remove excess components, and apply coating liquid 1 (1-1 and 1-2) and coating liquid 2 on the test piece. A coating was formed.

<Example 3>
0.55 wt% of silazane compound (0.45 wt% of perhydropolysilazane used in Example 1 and 0.10 wt% of methylhydropolysilazane used in Example 2), alkoxysilane compound (containing methoxysilyl group used in Example 1) Silane oligomer) 0.20 wt%, catalyst (both terminal amino group-modified silicone oil used in Example 1) 0.05 wt%, solvent 99.20 wt% (dibutyl ether 7.60 wt% and isoparaffinic A coating liquid 1 consisting of a hydrocarbon solvent (91.60 wt %) was prepared.

Also, the coating liquid 2 used in Example 2 was prepared.
Coating liquid 1 was applied to the test piece in the same manner as in Example 1, and the specimen was allowed to stand at room temperature for 15 minutes to dry the solvent. After standing at normal temperature for 15 minutes, the film was wiped off with a microfiber cloth moistened with water to remove excess components, and a film derived from coating solution 1 and coating solution 2 was formed on the test piece.

<Comparative Example 1>
Coating liquid 1 and coating liquid 2 were coated on the test piece in the same manner as in Example 1, except that the catalyst was not used and the isoparaffinic hydrocarbon solvent was 90.05 wt% in coating liquid 1 of Example 1. A coating was formed.

<Comparative Example 2>
Coating liquid 1 and coating liquid 2 were applied onto the test piece in the same manner as in Example 1, except that the alkoxysilane compound was not used and the isoparaffinic hydrocarbon solvent was 90.10 wt% in coating liquid 1 of Example 1. A film of origin was formed.

<Comparative Example 3>
Coating liquid 1 and coating liquid 2 were coated on the test piece in the same manner as in Example 1, except that the catalyst and the alkoxysilane compound were not used in the coating liquid 1 of Example 1, and the isoparaffinic hydrocarbon solvent was 90.15 wt%. A film derived from was formed.

<Comparative Example 4>
In the coating liquid 2 of Example 1, except that the siloxane compound was not used and the solvent was 100.0 wt%, a film derived from the coating liquid 1 and the coating liquid 2 was formed on the test piece in the same manner as in Example 1. formed.

<Comparative Example 5>
In Example 1, a film derived from coating liquid 1 was formed on the test piece in the same manner as in Example 1, except that coating liquid 2 was not applied.

<Comparative Example 6>
Equal amounts of the coating liquid 1 and the coating liquid 2 described in Example 1 were mixed, and in the same manner as in Example 1, this was taken on a sponge with microfiber nonwoven fabric and applied. After standing at room temperature for 15 minutes, wipe off the coating with a microfiber cloth moistened with water to remove excess components, and form a coating derived from a mixture of components of coating liquid 1 and coating liquid 2 on the test piece. let me

<Reference example 1>
Apply a commercially available coating liquid for forming a water-repellent, low-friction coating for automobile bodies (using polysilazane, silicone resin, silane compound, silane oligomer, and isoparaffin-based hydrocarbon solvent) to the test piece according to the instruction manual of the product, and apply the coating. formed.

<Evaluation of wiping durability>
Using a Gardner washability tester (manufactured by Yasuda Seiki Seisakusho), a car wash sponge with a constant load (450 g) is slid on the coating on the test piece at a constant speed (about 40 reciprocations per minute) to wipe off the coating. gone. Changes in water contact angle, water sliding angle, and slip angle due to wiping of the coating were measured.

A slip tester (manufactured by Yasuda Seiki Seisakusho) was used to measure the slip angle. Specifically, the test piece was fixed to the slope of the tester, and a weight of 1 kg was placed thereon. The weight is block-shaped, and a non-woven fabric is wrapped around the contact surface with the test piece. The slope was tilted at a tilting speed of 1 degree per second, and the angle at which the weight started to slide was defined as the slip angle.

The results are shown in Tables 1-3.

Table 1 shows the measurement results of the water contact angle, and indicates that the larger the water contact angle, the higher the water repellency of the coating. A water contact angle value of 103.0° or more is indicated by ◎, 100.0° or more and less than 103.0° is indicated by ○, 95.0° or more and less than 100.0° is indicated by △, and less than 95.0° is indicated by ×. . From the results in Table 1, Comparative Examples 1 to 3 lacking at least one of the essential components in coating liquid 1, Comparative Example 4 lacking one of the essential components in coating liquid 2, and only coating liquid 1 was applied. Compared to Comparative Example 5, Comparative Example 6 in which the components of Coating Liquid 1 and the components of Coating Liquid 2 were mixed and applied once, and the coating of Reference Example 1 using a commercially available coating liquid, the coatings of Examples 1 to 3 It can be seen that the water repellency of the film does not easily decrease even after washing and wiping. If the coating has high water repellency, it will have the effect of repelling rainwater and water droplets.

Table 2 shows the measurement results of the water sliding angle, and shows that the smaller the water sliding angle, the higher the water sliding property of the coating. A value of less than 12.0 ° is indicated by ◎, a value of 12.0 ° or more and less than 20.0 ° is indicated by ○, a value of 20.0 ° or more and less than 30.0 ° is indicated by △, and a value of 30.0 ° or more is indicated by ×. . From the results in Table 2, Comparative Examples 1 to 3 lacking at least one of the essential components in coating liquid 1, Comparative Example 4 lacking one of the essential components in coating liquid 2, and only coating liquid 1 was applied. Compared to Comparative Example 5, Comparative Example 6 in which the components of Coating Liquid 1 and the components of Coating Liquid 2 were mixed and applied once, and the coating of Reference Example 1 using a commercially available coating liquid, the coatings of Examples 1 to 3 It can be seen that the film is less likely to lose its water slip property even after washing and wiping. If the film has high water sliding properties, it is possible to prevent water droplets from sticking to the body, and it is possible to obtain the effect of suppressing water remaining on the body when it rains. In addition, there is the advantage that the water can be drained well, and the moisture can be easily removed by wiping during car washing.

Table 3 shows the results of slip measurement, and shows that the smaller the slip angle, the lower the friction of the coating surface. A value of less than 5.0° is indicated by ⊚, a value of 5.0° to less than 10.0° is indicated by ◯, a value of 10.0° to less than 15.0° is indicated by Δ, and a value of 15.0° or more is indicated by ×. From the results in Table 3, Comparative Examples 1 to 3 lacking at least one of the essential components in coating liquid 1, Comparative Example 4 lacking one of the essential components in coating liquid 2, and only coating liquid 1 was applied. Compared to Comparative Example 5, Comparative Example 6 in which the components of Coating Liquid 1 and the components of Coating Liquid 2 were mixed and applied once, and the coating of Reference Example 1 using a commercially available coating liquid, the coatings of Examples 1 to 3 It can be seen that the coating maintains a low friction surface after washing and wiping. When the friction of the film surface is low, there is an advantage that the film is less likely to be scratched during car washing or wiping.

As described above, the coating film obtained by the production method of the present invention exhibits excellent wiping durability at least in terms of water repellency, water slipperiness, and low friction.

Claims (11)

Step 1 of applying a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent to a substrate to form a porous coating on the substrate;
A method for producing a film, comprising a step 2 of applying a coating liquid 2 containing a siloxane compound and a solvent onto the porous film. 2. The method according to claim 1, wherein the catalyst in said coating liquid 1 is a silicone oil having an amino group. 3. The method according to claim 1, wherein the alkoxysilane compound in said coating liquid 1 is an alkoxysilane oligomer having an alkoxysilyl group. The method according to any one of claims 1 to 3, wherein the siloxane compound in the coating liquid 2 is a silicone oil having a silanol group. The method according to any one of claims 1 to 4, wherein the silazane compound in the coating liquid 1 is polysilazane. The method according to any one of claims 1 to 5, wherein the solvent in the coating liquid 2 is dimethylsilicone oil. The mixing ratio of the siloxane compound and the solvent in the coating liquid 2 is 0.1:99.9 to 10.0:90.0 in mass ratio, according to any one of claims 1 to 6 Method. A method according to any preceding claim, wherein the substrate is a painted surface of a vehicle body. The method according to any one of claims 1 to 8, wherein steps 1 and 2 are performed at normal temperature. a coating liquid 1 containing a silazane compound, an alkoxysilane compound, a catalyst, and a solvent;
A two-component film-forming composition containing a siloxane compound and a coating liquid 2 containing a solvent. a coating liquid 1 containing polysilazane, an alkoxysilane oligomer having an alkoxysilyl group, a silicone oil having an amino group, and a solvent;
A two-component film-forming composition containing a silicone oil having a silanol group and a coating liquid 2 containing a dimethylsilicone oil.