JP7108199B2 - Film-forming composition - Google Patents

Description

The present invention relates to a film-forming composition. More particularly, the present invention relates to a film-forming composition capable of obtaining a thin film coating layer for imparting weather resistance, durability, etc., to metal surfaces, painted surfaces, or resin surfaces of automobile bodies and train cars. .

Conventionally, for the purpose of protection and improvement of beauty, it has been practiced to apply and apply a solid, semi-solid or liquid film-forming composition to a coated steel plate of an automobile body or the like. Examples of such a film-forming composition include a moisture-curable organopolysiloxane, an organic solvent, and a curing catalyst, to which a volatile organopolysiloxane oil and a volatile dimethylpolysiloxane are added (Patent Document 1: JP-A-10-10 -36771) and a composition to which high-viscosity silicone gum is added (Patent Document 2: JP-A-2013-194058). However, in these compositions, the non-reactive organopolysiloxane oil evaporates and dissipates over time, making it difficult to exhibit water repellency and water slippage over a long period of time.

Various compositions comprising moisture-curable silicone oligomers, organic solvents, curing catalysts, and silicone oils having reactive functional groups in their molecules have been proposed to solve the above problems. Patent Document 3 (Japanese Patent Application Laid-Open No. 2011-246664) describes a mixture of moisture-curable silicone oligomers with different viscosities, a hydrolytic curing catalyst selected from titanium-based compounds and aluminum-based compounds, and a volatilization catalyst selected from hydrocarbon-based compounds. Disclosed is a surface water repellent protectant composition comprising a soluble solvent and a perfluoropolyether silane compound. In addition, Patent Document 4 (Japanese Patent Laid-Open No. 2007-070606), Patent Document 5 (Japanese Patent Laid-Open No. 2008-038049), etc. disclose a mixture of silicone oligomers with different viscosities, a moisture curing catalyst of a titanium compound, and n-hexane. A composition for forming an antifouling film comprising an organic solvent selected from among the following is disclosed.

However, in the compositions of Patent Documents 3 to 5, the composition ratio of high-viscosity silicone oligomer to low-viscosity silicone oligomer (high-viscosity silicone oligomer/low-viscosity silicone oligomer) is about 1/4 to 1/5. Moreover, the boiling point of the diluent or solvent is not set within an appropriate range. Therefore, there is a problem that it is difficult to form a uniform coating and that the coating cannot exhibit sufficient antifouling performance.

In addition, from the viewpoint of workability, the film-forming composition is also required to have moderate drying properties.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a film-forming composition capable of forming a uniform film having moderate drying properties and excellent antifouling properties. Another object of the present invention is to provide a method for forming a film using such a film-forming composition, a cured film, and a method for producing the above-mentioned film-forming composition.

Thus, it has been difficult for conventional film-forming compositions to satisfy the required properties at the same time. As a result of intensive studies aimed at improving these properties, the present inventors have found that the above problems can be solved by using a film-forming composition having the following constitution.

That is, the first embodiment of the present invention includes the following (A) to (C), and the content of the following (A) is 0.35 to 0.58 mass with respect to 1 part by mass of the following (C) parts, and the content of the following (B) is 0.05 to 0.15 parts by mass:
(A) a mixture of film-forming components containing the following (A-1) and (A-2) at a mass ratio of (A-1)/(A-2) = 1/26 to 1/36;
(A-1) Hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 (A-2) Kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 (B) an organoaluminum compound; and (C) a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165°C.

The present invention also includes the following embodiments.

A second embodiment is the film-forming composition according to the first embodiment, wherein the boiling point of (C) is in the range of 110 to 155°C.

A third embodiment is the film-forming composition according to the first or second embodiment, wherein (C) is a saturated aliphatic hydrocarbon solvent.

In a fourth embodiment, (C) is at least one selected from the group consisting of 2-methyloctane, 3-methyloctane, 4-methyloctane, 4-ethylheptane, and 2,3-dimethylheptane. The film-forming composition according to any one of the first to third embodiments, comprising:

A fifth embodiment is the film-forming composition according to any one of the first to fourth embodiments, wherein (B) contains an aluminum alkoxide compound.

A sixth embodiment is the film-forming composition according to any one of the first to fifth embodiments, which is used for forming a film on the surface of a steel plate or a coated steel plate.

A seventh embodiment is the film-forming composition according to the sixth embodiment, wherein the steel plate or coated steel plate is an automobile body.

In an eighth embodiment, the film-forming composition according to any one of the first to fifth embodiments is applied to the surface of a steel plate or a coated steel plate, and the (C) is applied at room temperature or in a heated environment. A method for forming a film comprising wiping dry after volatilization, or wiping with water and then wiping dry.

A ninth embodiment is the film forming method according to the eighth embodiment, wherein the steel plate or coated steel plate is an automobile body.

A tenth embodiment is a cured film obtained by curing the film-forming composition according to any one of the first to seventh embodiments.

In the eleventh embodiment, (A-1) a hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25° C. in the range of 100 to 250 mm ² s ⁻¹ ;
(A-2) a hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 ;
(B) an organoaluminum compound;
(C) A method for producing a film-forming composition comprising mixing with a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165° C.,
The (A-1) and (A-2) are mixed at a mass ratio of (A-1) / (A-2) = 1/26 to 1/36,
The film-forming composition contains 0.35 to 0.58 parts by mass of (A-1) and (A-2) in total with respect to 1 part by mass of (C), and A method for producing a film-forming composition containing 0.05 to 0.15 parts by mass.

Embodiments of the present invention will be described below. In addition, the present invention is not limited only to the following embodiments. Unless otherwise specified, measurements of operations, physical properties, etc. are carried out under conditions of room temperature (range of 20° C. to 25° C.)/relative humidity of 40 to 50% RH.

The film-forming composition according to the present invention contains the following (A) to (C), and the content of the following (A) is 0.35 to 0.58 parts by mass with respect to 1 part by mass of the following (C). and the content of the following (B) is 0.05 to 0.15 parts by mass:
(A) a mixture of film-forming components containing the following (A-1) and (A-2) at a mass ratio of (A-1)/(A-2) = 1/26 to 1/36;
(A-1) Hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 (A-2) Kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 (B) an organoaluminum compound; and (C) a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165°C.

The film-forming composition having the above-described structure has appropriate drying properties and can form a uniform film having excellent antifouling properties. In addition, the film-forming composition has good storability and excellent workability in the wiping step. Furthermore, according to the film-forming composition, a film (film coating layer) having good weather resistance can be formed on a steel plate or a painted steel plate used for automobile bodies and the like. Then, the film can have excellent water repellency, water slipperiness, and abrasion resistance.

The details of the present invention will be described below.

[Film-forming composition]
<Component (A)>
Component (A) contained in the film-forming composition of the present invention is the following (A-1) and (A-2): (A-1)/(A-2) = 1/26 to 1/36 is a mixture of film-forming components containing a mass ratio of:
(A-1) Hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 (A-2) Kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 A hydrolyzable group-containing silicone oligomer.

Here, the "hydrolyzable group" includes an alkoxy group, an alkenyloxy group, an acyloxy group, an amino group, an aminooxy group, an oxime group, an amide group and the like. Among them, the hydrolyzable group contained in the silicone oligomer is preferably an alkoxy group because it is easy to handle.

As used herein, the term "hydrolyzable group-containing silicone oligomer" refers to the partial hydrolysis of a silane compound having a hydrolyzable group with an acid, a base, or a known catalyst such as an organic tin compound or an organic titanium compound, followed by condensation ( In this specification, it is also referred to as “partial hydrolysis condensation”), which has a hydrolyzable group derived from the silane compound at the molecular chain end or side chain, and has a weight average molecular weight of 550 to It is a silicone compound having a molecular weight of between 20,000 and a linear structure, a branched structure, or a three-dimensional network structure.

Preferred forms of the silane compound having a hydrolyzable group for obtaining the silicone compound (silicone oligomer) include polyfunctional alkoxysilane compounds such as dialkoxysilane compounds, trialkoxysilane compounds, tetraalkoxysilane compounds, and monoalkoxysilane compounds. compounds (monofunctional alkoxysilane compounds). In addition, the said silane compound may be used individually by 1 type or in combination of 2 or more types.

Accordingly, the hydrolyzable group-containing silicone oligomers as components (A-1) and (A-2) are preferably partial hydrolysis condensates of alkoxysilane compounds represented by the following formula (1). The partial hydrolysis condensate may be obtained by using only one type of alkoxysilane compound represented by the following formula (1), or may be obtained by combining two or more types. can be anything.

In the above formula (1), R ¹ and R ² are each independently an aliphatic hydrocarbon group having 1 to 8 carbon atoms and an alicyclic group having 3 to 10 carbon atoms, which may have a substituent. is a hydrocarbon group or an aromatic hydrocarbon group having 6 to 10 carbon atoms. When these groups have substituents, the substituents are not particularly limited, and include alkyl groups, alkenyl groups, aryl groups, halogen atoms, nitro groups, cyano groups, hydroxy groups, carboxy groups and the like. In addition, in the above, they are not substituted with the same substituent. For example, a substituted alkyl group is not substituted with an alkyl group.

R ¹ and R ² are preferably substituents each independently selected from the group consisting of aliphatic hydrocarbon groups having 1 to 5 carbon atoms and aromatic hydrocarbon groups having 6 to 10 carbon atoms. , more preferably each independently a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group and a phenyl group, and particularly preferably each independently a methyl group or a phenyl group be.

In the above formula (1), x is an integer of 0-3. When the alkoxysilane compound represented by the above formula (1) is used alone, x is preferably an integer of 0 to 2, more preferably 1 or 2. Furthermore, when two or more of the alkoxysilane compounds are used, at least a first alkoxysilane compound in which x is an integer of 1 to 3 and a second alkoxysilane compound in which x is an integer of 0 to 3 are used. It is preferable to use them together (however, the first alkoxysilane compound and the second alkoxysilane compound both exclude the form in which x=3).

As a method for producing the component (A-1) and the component (A-2), a known hydrolysis catalyst is added to the alkoxysilane compound represented by the above formula (1), and the mixture is heated and stirred in the presence of water. Examples include, but are not limited to, a method in which partial hydrolysis condensation is caused by the reaction. Here, in the above formula (1), when x is 0 or 1, when the main skeleton of the polymer of the alkoxysilane compound is linear, the alkoxy represented by (OR ² ) in the side chain group. In addition, when the main skeleton of the polymer does not have a linear structure but constitutes a branched structure or a three-dimensional crosslinked body, the structure may partially contain an alkoxy group represented by (OR ² ). becomes. The alkoxysilane compound may contain one in which x is 2 or 3 in the above formula (1), but an alkoxy group is effectively included in the structures of components (A-1) and (A-2). In order to add to , x is preferably 0 or 1 in the above formula (1). In addition, in the above formula (1), since the alkoxysilane compound in which x is 3 alone cannot form a polymer, when the alkoxysilane compound in which x is 3 is included, x is assumed to be in the range of 0 to 2. Partial hydrolytic condensation is carried out in combination.

<<Component (A-1)>>
Component (A-1) contained in the mixture as component (A) is a hydrolyzable group-containing silicone oligomer having a viscosity of 100 to 250 mm ² s ^-1 at 25°C. Here, the “viscosity” is the kinematic viscosity (mm ² s ⁻¹ ) at 25° C. measured by a viscosity measurement method based on JIS Z 8803:2011. For example, the kinematic viscosity can be measured with a single cylindrical rotational viscometer (B-type viscometer). Further, the description of the "hydrolyzable group-containing silicone oligomer" is as described above.

Component (A-1) is a component necessary for exhibiting its function in a cured film formed from the film-forming composition of the present invention, and is used in concert with component (A-2) described later for film formation. It is presumed that it is a component that contributes to and mainly acts on antifouling performance. Therefore, it is believed that the film-forming composition according to the present invention can form a uniform film having excellent antifouling properties. It should be noted that the above mechanism is based on speculation, and its correctness or wrongness does not affect the technical scope of the present invention.

A person skilled in the art can control the viscosity of the hydrolyzable group-containing silicone oligomer used as component (A-1) by adjusting the molecular weight (weight average molecular weight) and composition of the oligomer.

The weight average molecular weight of the hydrolyzable group-containing silicone oligomer used as component (A-1) is not particularly limited, but is preferably 5,000 or more and 20,000 or less, and preferably 7,000 or more and 14,000 or less. more preferred.

As used herein, the "weight average molecular weight" is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance. The measurement conditions are as follows;
"Measurement condition"
Column: TSKgel (registered trademark) SuperMultipore HZ-M (manufactured by Tosoh Corporation)
Flow rate: 0.35 mL/min Column temperature: 40°C
Eluent: THF
Sample: 100 g of THF was dissolved so that the oligomer content was 0.1% by mass, and then measured.

The composition of the hydrolyzable group-containing silicone oligomer used as component (A-1) is preferably a partial hydrolysis condensate of the alkoxysilane compound represented by the above formula (1). Preferred forms of the alkoxysilane compound are as described above.

Here, as the component (A-1), a synthetic product or a commercially available product can be used as long as it is a silicone oligomer having the properties described above. Commercially available products include, for example, X-40-9250 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25° C. is 160 mm ² s ⁻¹ , in the above formula (1), both R ¹ and R ² are methyl groups. , a partial hydrolysis condensate obtained from a mixture of alkoxysilane compounds where x = 1 or 2), X-40-9225 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25 ° C. is 100 mm ² s ^-1 , the above formula (1), a partial hydrolyzed condensate of an alkoxysilane compound in which both R ¹ and R ² are methyl groups), KR-510 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25 ° C. is 100 mm ² s ^-1 , partial hydrolysis condensate of an alkoxysilane compound in which R ¹ is a methyl group or a phenyl group and R ² is a methyl group in the above formula (1)), XR31-B2733 (manufactured by Momentive Performance Materials Japan LLC. , a kinematic viscosity at 25° C. of 220 mm ² s ⁻¹ , and in the above formula (1), R ¹ is a methyl group or a phenyl group, R ² is a methyl group, and x=1 or 2. partially hydrolyzed condensate obtained from a mixture), etc., and these may be used alone or in combination of multiple kinds.

<<Component (A-2)>>
Component (A-2) contained in the mixture as component (A) is a hydrolyzable group-containing silicone oligomer having a viscosity of 21 to 90 mm ² s ^-1 at 25°C. Here, the “viscosity” is the kinematic viscosity (mm ² s ⁻¹ ) at 25° C. measured by a viscosity measurement method based on JIS Z 8803:2011. For example, the kinematic viscosity can be measured with a single cylindrical rotational viscometer (B-type viscometer). Further, the description of the "hydrolyzable group-containing silicone oligomer" is as described above.

Component (A-2) is a major component in forming a cured film from the film-forming composition of the present invention, and is presumed to be a component that mainly contributes to the formation of a homogeneous film. Therefore, it is considered that a uniform coating can be formed by using the coating composition according to the present invention. In addition, component (A-2) can contribute to the antifouling property and weather resistance of the film. On the other hand, when a hydrolyzable group-containing silicone oligomer having a kinematic viscosity of less than 21 mm ² s ⁻¹ or more than 90 mm ² s ⁻¹ is used, compatibility with the component (A-1) deteriorates, resulting in reduced film formability. In addition, the antifouling property and weather resistance deteriorate. It should be noted that the above mechanism is based on speculation, and its correctness or wrongness does not affect the technical scope of the present invention.

A person skilled in the art can control the viscosity of the hydrolyzable group-containing silicone oligomer used as component (A-2) by adjusting the molecular weight (weight average molecular weight) and composition of the oligomer.

The weight average molecular weight of the hydrolyzable group-containing silicone oligomer used as component (A-2) is not particularly limited, but is preferably 1,000 or more and less than 5,000, and preferably 1,500 or more and 2,500 or less. more preferred.

The composition of the hydrolyzable group-containing silicone oligomer used as component (A-2) is preferably a partial hydrolysis condensate of the alkoxysilane compound represented by formula (1) above. Preferred forms (structures) of the alkoxysilane compound are as described above.

As the component (A-2), synthetic products and commercially available products can be used as long as they are silicone oligomers having the properties described above. Commercially available products include, for example, KR-500 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25° C. is 25 mm ² s ⁻¹ , in the above formula (1), both R ¹ and R ² are methyl groups, x = 1 or 2), KR-9218 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25 ° C. is 40 mm ² s ^-1 , in the above formula (1), R ¹ is X ^- 40-9246 (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity at 25° C. of 80 mm ² s ⁻¹ , above Partial hydrolysis condensate of an alkoxysilane compound in which both R ¹ and R ² in formula (1) are methyl groups), TSR165 (manufactured by Momentive Performance Materials Japan LLC, kinematic viscosity at 25 ° C. of 80 mm) ² s ⁻¹ , a partially hydrolyzed condensate of an alkoxysilane compound in which R ¹ is a methyl group or a phenyl group and R ² is a methyl group in the above formula (1), etc., and these can be used alone. You may use multiple types together.

In the film-forming composition of the present invention, the mass ratio of the components (A-1)/(A-2) is in the range of 1/26 to 1/36. When the mass ratio of component (A-2) to component (A-1) is smaller than the above range (for example, (A-1)/(A-2) = 1/25), the film-forming composition Insufficient wettability to the base material (preferably steel plate or coated steel plate) when the object is coated, and it is difficult to form a uniform coating, and a uniform coating cannot be formed. . On the other hand, when the mass ratio of component (A-2) to component (A-1) is greater than the above range (for example, (A-1)/(A-2) = 1/37), the coating becomes insufficient antifouling property. The reason for this is considered to be insufficient wettability to a substrate (preferably a steel plate or a coated steel plate) when the film-forming composition is used as a film. Therefore, the film-forming composition of the present invention contains components (A-1) and (A-2) at a mass ratio of (A-1)/(A-2)=1/26 to 1/36. As a result, the film-forming ability is excellent, and the antifouling property and wettability of the film are improved. In order to make it easier to obtain such effects, the mass ratio of (A-1)/(A-2) is more preferably in the range of 1/27 to 1/35, more preferably 1/28 to 1/ A range of 30 is particularly preferred.

The content of the component (A) in the film-forming composition of the present invention, that is, the sum of the content of the component (A-1) and the component (A-2) is 1 mass of the component (C) described later. It is in the range of 0.35 to 0.58 parts by mass per part. If the content of the component (A) exceeds 0.58 parts by mass, the film-forming ability and antifouling properties on a substrate (preferably a steel plate or a coated steel plate) when the film-forming composition is used as a film are lowered. In addition, the wettability and weather resistance also deteriorate. On the other hand, when the content of the component (A) is less than 0.35 parts by mass, the film-forming ability and antifouling properties of the film become insufficient. The reason for this is thought to be that too little or too much of the film-forming component causes film failure. Therefore, by setting the content of the component (A) in the film-forming composition of the present invention within the above range, the film-forming ability is excellent, and the antifouling property, wettability and weather resistance of the film are improved. In order to make it easier to obtain such effects, the content of component (A) is more preferably in the range of 0.38 to 0.50 parts by mass with respect to 1 part by mass of component (C). A range of 0.40 to 0.48 parts by mass is particularly preferred.

<Component (B)>
Component (B) contained in the film-forming composition of the present invention is an organoaluminum compound. The organoaluminum compound as the component (B) is known as a condensation reaction catalyst, and the hydrolyzable group (preferably Si—OR ² ) contained in the component (A) is converted to moisture in the air. It is a compound for reacting with such as to cause a condensation reaction. In the present invention, by using an organoaluminum compound as a condensation reaction catalyst, a uniform and uniform coating can be formed. Therefore, the film-forming composition according to the present invention has excellent film-forming ability. In addition, by using an organoaluminum compound instead of other metal compounds as a condensation reaction catalyst, the film-forming composition according to the present invention can form a film with good weather resistance. The reason for this is that the use of the organoaluminum compound allows the condensation reaction of the hydrolyzable groups contained in component (A) to proceed at an appropriate rate, thereby forming a uniform coating. Conceivable.

As the organoaluminum compound as component (B), known substances used as condensation reaction catalysts can be used.

Specific examples of organoaluminum compounds include aluminum salt compounds such as aluminum octylate, aluminum triacetate and aluminum tristearate; aluminum alkoxide compounds such as aluminum trimethoxide, aluminum triethoxide, aluminum triallyloxide and aluminum triphenoxide; aluminum methoxybis(ethylacetoacetate), aluminum methoxybis(acetylacetonate), aluminum ethoxybis(ethylacetoacetate), aluminum ethoxybis(acetylacetonate), aluminum isopropoxybis(ethylacetoacetate), aluminum isopropoxybis (methylacetoacetate), aluminum isopropoxybis (t-butylacetoacetate), aluminum butoxybis (ethylacetoacetate), aluminum dimethoxy (ethylacetoacetate), aluminum dimethoxy (acetylacetonate), aluminum diethoxy (ethylacetoacetate) ), aluminum diethoxy (acetylacetonate), aluminum diisopropoxy (ethylacetoacetate), aluminum diisopropoxy (methylacetoacetate), aluminum tris (ethylacetoacetate), aluminum tris (acetylacetonate), aluminum octylacetate Examples include aluminum chelate compounds such as acetate diisopropylate. These may be used alone or in combination of multiple types. The condensation reaction of the hydrolyzable groups contained in component (A) can proceed at an appropriate rate, a uniform coating can be formed, and the weather resistance can be improved. B) preferably comprises an aluminum alkoxide compound.

As the organoaluminum compound as the component (B), known commercial products can be used, for example, Shin-Etsu Chemical Co., Ltd. DX-9740 (mixture of aluminum alkoxide compounds), CAT-AC (mixture of aluminum alkoxide compounds , 50 mass% toluene dilution), aluminum chelate A (W) (aluminum tris (acetylacetonate)) manufactured by Kawaken Fine Chemicals Co., Ltd., aluminum chelate D (aluminum monoacetylacetonate bis (ethylacetoacetate), effective component amount 76% by mass), AIPD (aluminum isopropylate), ALCH (aluminum diisopropoxy (ethylacetoacetate)), ALCH-TR (aluminum tris (ethylacetoacetate)), and the like are used. These may be used alone or in combination of multiple types.

The content of component (B) in the present invention (the total amount when two or more organoaluminum compounds are used) is 0.05 to 0.15 mass per 1 part by mass of component (C) described later. part range. When the content of the component (B) exceeds 0.15 parts by mass, the reactivity of the entire resin becomes too high, and the film-forming ability of the film-forming composition is reduced. Weather resistance and discoloration resistance cannot be made appropriate. On the other hand, when the content of the component (B) is less than 0.05 parts by mass, the reactivity becomes insufficient, so that the curability at the time of film formation is lowered, and the product cannot be used with an appropriate pot life. . Therefore, by setting the content of the component (B) in the film-forming composition of the present invention within the above range, the film-forming ability and drying property (curing property) are improved, and weather resistance and discoloration resistance are improved. improves. In order to make it easier to obtain such effects, the content of the component (B) is more preferably in the range of 0.06 to 0.14 parts by mass with respect to 1 part by mass of the component (C). A range of 0.08 to 0.12 parts by weight is particularly preferred.

<Component (C)>
Component (C) contained in the film-forming composition of the present invention is a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165°C. The hydrocarbon-based organic solvent as component (C) is a component necessary for uniformly dissolving and diluting the components (A) and (B) to form a thin film. If the boiling point of the component (C) exceeds 165° C., not only the film-forming ability and the drying property (curing property) are lowered, but also the wettability cannot be adequate. On the other hand, if the boiling point of the component (C) is less than 100°C, the film-forming ability is lowered. By setting the boiling point of the component (C) in the film-forming composition of the present invention within the above range, the film-forming ability and drying property (curing property) are improved, and the wettability is improved. The reason for this is that the boiling point within the above temperature range ensures that the volatility of the film-forming composition is appropriate when forming a film, and that component (A) and component (B) do not interact unnecessarily. This is considered to be because the action can be suppressed. Therefore, according to the film-forming composition of the present invention, it becomes possible to form a dense film.

The boiling point of component (C) is more preferably in the range of 110 to 155.degree. C., and particularly preferably in the range of 120 to 150.degree.

The hydrocarbon-based organic solvent contained in the film-forming composition of the present invention includes a solvent (hydrocarbon solvent) consisting essentially of a hydrocarbon compound. The hydrocarbon solvent may be either an aliphatic hydrocarbon solvent or an aromatic hydrocarbon solvent. Moreover, the aliphatic hydrocarbon solvent may have any of a linear structure, a branched structure and a cyclic structure, and the aliphatic hydrocarbon solvent may have an unsaturated bond. A particularly preferred component (C) in the present invention is a saturated aliphatic hydrocarbon solvent. By using a saturated aliphatic hydrocarbon solvent, the interaction between component (A) and component (B) can be reduced, and the volatility of component (C) is improved, thereby improving the drying properties of the film-forming composition. be able to.

Component (C) may contain other solvents having a boiling point within the above temperature range, such as hydrocarbon solvents having at least one halogen or various organic functional groups, as long as they do not interfere with the effects of the present invention. You can When component (C) contains such a hydrocarbon solvent, the content thereof is preferably less than 25%, more preferably less than 15%, and less than 10% of the total amount of component (C). is particularly preferred, and substantially 0% is most preferred. That is, component (C) preferably consists essentially of a hydrocarbon solvent. Further, component (C) more preferably consists essentially of a saturated aliphatic hydrocarbon solvent.

In some cases, component (C) does not have a single boiling point because it contains two or more solvents. In such a case, a solvent having a distillation start temperature (initial boiling point) and a distillation end temperature (dry point) within the above range is considered to correspond to the component (C) in the present invention.

In the present invention, the hydrocarbon solvent as component (C) is not particularly limited as long as it has a boiling point within the above range. Specifically, n-octane (boiling point 126 ° C.), 2-methyloctane (also called isononane, boiling point 143 ° C.), 3-methyloctane (boiling point 144 ° C.), 4-methyloctane (boiling point 142 ° C.), 4- Ethylheptane (boiling point 141°C), 2,3-dimethylheptane (boiling point 140°C), 1,3,5-trimethylcyclohexane (boiling point 140°C), 1,2,4-trimethylcyclohexane (boiling point 145°C), cyclooctane (boiling point 149°C), 1,1,3,5-tetramethylcyclohexane (boiling point 148°C), cyclooctane (boiling point 149°C), toluene (boiling point 111°C), o-xylene (boiling point 144°C), m-xylene (boiling point 139°C), p-xylene (boiling point 138°C), ethylbenzene (boiling point 136°C), and the like. These solvents may be used alone or in combination of two or more.

In particular, component (C) preferably contains at least one selected from the group consisting of 2-methyloctane, 3-methyloctane, 4-methyloctane, 4-ethylheptane, and 2,3-dimethylheptane.

<Other ingredients>
Any additive component can be added to the film-forming composition of the present invention within a range that does not impair its properties. Examples of such additive components include reactive or non-reactive silicone oils, alkoxysilane compounds, adhesion promoters such as silane coupling agents, anti-aging agents, rust inhibitors, colorants, surfactants, and rheology modifiers. agents, ultraviolet absorbers, infrared absorbers, fluorescent agents, abrasives, fragrances, fillers, etc., and components can be selected according to the purpose.

[Method for producing film-forming composition]
The film-forming composition according to the present invention can be produced by mixing the components described above in a predetermined ratio. That is, according to another aspect of the present invention, (A-1) a hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25° C. in the range of 100 to 250 mm ² s ⁻¹ and (A-2) 25 ( ^B ) an ^{organoaluminum} compound, and (C) a hydrocarbon having a boiling point in the range of 100 to 165°C. A method for producing a film-forming composition, comprising mixing the (A-1) and (A-2) with an organic solvent, wherein (A-1) / (A-2) = 1 /26 to 1/36, and the film-forming composition contains (A-1) and (A-2) with respect to 1 part by mass of (C). Provided is a method for producing a film-forming composition containing 0.35 to 0.58 parts by mass in total and 0.05 to 0.15 parts by mass of (B).

There are no particular restrictions on the order of addition, method of addition, etc. of the above components. Also, the mixing method and mixing time are not particularly limited, and methods known to those skilled in the art can be used. For the preferred composition ratio (mass ratio) of each component, the type of compound, the structure, etc., in the production method described above, the description given in the above section "Coating film forming composition" is used.

[Use of film-forming composition]
The film-forming composition of the present invention can be applied to substrates such as various metals, glasses, ceramics, and resins. Among them, it is suitable for application to metal steel sheets, painted metal steel sheets, and glass surfaces, and in particular to coated steel sheets used for automobile exteriors (also referred to as automobile exterior steel sheets in this specification). Use is preferred. That is, a preferred embodiment of the present invention is one in which the film-forming composition is used to form a film on the surface of a steel plate or a coated steel plate. Further, a more preferable embodiment is one in which the steel sheet or coated steel sheet is a vehicle body of an automobile.

According to another aspect of the present invention, there is provided a method of forming a film using the film-forming composition. In the film forming method of the present invention, the film-forming composition is applied to the surface of a steel plate or a coated steel plate (preferably, an automobile body), and the component (C) is volatilized at room temperature or in a heated environment. After that, dry wiping is further performed, or dry wiping is performed after further wet wiping. That is, after volatilization of the component (C), only dry wiping may be performed, or wet wiping may be performed before dry wiping. As used herein, the term "normal temperature" refers to a temperature in a room temperature environment that is not temperature-controlled by air conditioning or the like, and means about 15 to 25°C. In this specification, the term "heated environment" refers to an environment heated by air conditioning, a heater (heat ray irradiation means), etc., or a constant temperature environment set to a high temperature (e.g., standing still in a constant temperature room). It refers to an environment above room temperature and above ℃. In the present invention, a method of applying the film-forming composition to the surface of a steel plate or a coated steel plate, wiping with water, and then wiping with a dry cloth (that is, the latter application method) may be employed. A method of applying the film-forming composition to the surface of the steel plate or coated steel plate and then only wiping with a dry cloth (that is, the former application method) may be employed. A cured film having good properties can be obtained by any of the above methods. Thus, the film-forming composition and the film-forming method according to the present invention are characterized by excellent workability during application.

In addition, the application means (application method of the film-forming composition) at the time of film formation in the film-forming method is not particularly limited. For example, hand coating using fibers impregnated with the composition, brush coating, Any appropriate application means such as mechanical coating using an automatic machine can be used. In the present invention, the following methods are preferably used. That is, according to a preferred embodiment of the film-forming method of the present invention, fibers such as dry sponges and waste cloths are impregnated with an appropriate amount of the film-forming composition of the present invention, and the impregnated film-forming composition is manually applied. Spread thinly on the surface of a steel plate or coated steel plate (substrate), and volatilize volatile components by natural drying or forced drying using a dryer or the like. At this time, the component (A), which is a reaction component contained in the film-forming composition, comes into contact with moisture in the air, and the hydrolysis reaction proceeds due to the action of the component (B) (that is, the catalyst), Simultaneously with volatilization of the volatile components, it cross-links and hardens on the steel plate or coated steel plate (substrate) to form a resin-like hardened product. After that, the cured product can be spread by wiping with a dry cloth or the like to form a uniform coating layer of cured film. In the conventionally known film forming method, a post-process such as a process of performing a surface treatment with a treatment liquid for wiping off separately and then wiping with a dry cloth is required at the time of application. Here, in the film forming method of the present invention, these post-processes may be performed, but according to the film forming method of the present invention, even if only dry wiping treatment is performed with a dry cloth after solvent volatilization, a homogeneous film can be obtained immediately. A cured film can be obtained. That is, the film forming method according to the present invention is extremely excellent in workability.

Furthermore, according to another aspect of the present invention, there is provided a cured film obtained by curing the film-forming composition. A cured film formed using the film-forming composition has excellent antifouling properties and is a homogeneous (uniform) film. In addition, the cured film can have excellent weather resistance and good water repellency.

Here, the cured film according to the present invention is preferably in the form of a thin film. It is even more preferable if there is, and it is particularly preferable if it is 0.05 to 10 μm. When the film thickness of the cured film is within this range, good antifouling properties and weather resistance can be exhibited, and workability during construction is also excellent. Furthermore, by setting the film thickness within the above range, it is possible to improve water repellency, water sliding property and abrasion resistance.

As described above, the present invention provides means for forming a homogeneous film having moderate drying properties (good workability during application) and excellent antifouling properties. Furthermore, the present invention provides means for forming a coating with excellent weather resistance and discoloration resistance (storability). Furthermore, according to the present invention, a means for forming a coating having water repellency, water slipperiness, and abrasion resistance can be provided. INDUSTRIAL APPLICABILITY The present invention is particularly useful for forming a film for imparting water repellency, water slippage, durability, etc. to steel or coated steel sheets such as metal surfaces of automobile bodies and train cars, painted surfaces, and resin surfaces. .

EXAMPLES The effects of the present invention will be described in detail below with reference to examples, but these examples are not intended to limit the aspects of the present invention.

The present invention will be described in more detail with the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. Unless otherwise specified, the following operations and physical properties were measured under the conditions of room temperature (range of 20° C. to 25° C.)/relative humidity of 40 to 50% RH.

Using the following method, each film-forming composition (hereinafter also simply referred to as “composition”) prepared in Examples and Comparative Examples was evaluated for characteristics.

[Wettability evaluation method]
Approximately 2 mL of each composition was soaked into tissue paper. Black coated plate (material: SPCC-SD (cold rolled steel plate), standard: JIS G 3141: 2017, dimensions: 0.8 mm × 70 mm × 150 mm, one side coated with aminoalkyd black after chemical electrodeposition, Co., Ltd. Asahi Bee Techno Co., Ltd.) was thinly coated by hand using the tissue paper to prepare a test piece. The wet state of the surface was evaluated by visually observing the coated surface of the test piece immediately after coating. The evaluation criteria were as follows. That is, the uncured liquid composition on the surface to be coated is uniformly present on the test piece, and the portion where the composition is not present (so-called repelling state) is less than 10% of the entire surface to be coated. A certain sample was accepted (indicated by “○” in the table). In addition, other states were regarded as disqualified (indicated by "x" in the table).

[Method for evaluating film-forming ability]
After applying the composition to the same black coated plate used in the wettability evaluation, the composition was applied in a room at 25 ° C. and allowed to stand for 10 minutes, and then the surface to be coated was dried with a microfiber cloth. wiped off with Further, it was cured by standing still in a room at 25° C. for 12 hours to obtain a test piece having a cured film (thickness: about 0.01 to 100 μm) composed of the composition on its surface. The film-forming ability was evaluated by visually observing the coated surface of the test piece. The evaluation criteria were as follows. That is, the cured film on the surface to be coated is a uniform cured film without unevenness, and the cured product is so-called repellent, dented, or mottled in less than 10% of the surface to be coated. It was set as a pass (it was described with "○" in the table|surface). In addition, other states were regarded as disqualified (indicated by "x" in the table).

[Anti-fouling evaluation method]
Letters were written with a permanent pen (Himackey (registered trademark) black manufactured by Zebra Co., Ltd.) on the surface of the test piece on which the cured film had been formed, which was prepared under the same conditions as the test piece for evaluating the film-forming ability. Then, the stain resistance was evaluated by visually observing the state of the characters after lightly rubbing the area with a tissue paper. The evaluation criteria were as follows. That is, when the written characters were removed and the ink of the oil-based pen disappeared from the surface to be coated, it was evaluated as acceptable (indicated by "◯" in the table). In addition, other states were regarded as disqualified (indicated by "x" in the table).

[Drying property evaluation method]
A test piece prepared under the same conditions as the wettability evaluation test piece was dried to an arbitrary point on the coated surface by a method according to JIS K 5600-3-3:1999 dry-to-touch test to measure the drying time. Measurements were performed at 30-minute intervals from 5 minutes after the application of the composition at room temperature (25° C.) to evaluate the dryness. The evaluation criteria were as follows. That is, in the following table, A indicates that the dry-to-touch time is 30 minutes or less, B indicates that the drying time is more than 30 minutes and 60 minutes or less, and C indicates that it exceeds 60 minutes. If the wettability evaluation failed (x), a uniform coating film was not formed on the coating film surface, but the measurement was performed by touching a portion where wetness was present. Although A has high drying property, it has a short pot life during construction, which is not preferable from the viewpoint of workability. Moreover, C is not preferable because it takes a long drying time. Therefore, in the present invention, those rated as B are particularly preferable in view of the balance between the pot life and the drying property during construction.

[Weather resistance evaluation method]
The same test piece as that prepared in the film-forming ability evaluation was placed in a sunshine weather meter (ATLAS Ci4000 manufactured by Atlus Electric Devices, 6500 W water-cooled xenon arc lamp light source) and exposed to sunlight conditions (irradiance 0.5 W / m ² , irradiation light wavelength 400 to 700 nm, BP temperature 65 ± 3 ° C., humidity 70 ± 5%) × 120 minutes and rainfall conditions (200 mL / min) × 30 minutes are alternately repeated, and subjected to a weather resistance test for a total of 500 hours. . After that, the test piece was subjected to the same test as the antifouling evaluation, and was evaluated according to the evaluation criteria described above.

[Discoloration resistance evaluation method]
About 50 mL of the uncured liquid of each composition was sampled immediately after production and sealed in a 100 mL colorless and transparent glass sample bottle. The sample bottle was stored in a constant temperature bath kept at 40° C., and color fastness was evaluated by visually observing the hue of the composition liquid after 30 days. The evaluation criteria were as follows. That is, when compared with the initial state, which was colorless and transparent, no yellowing or browning was observed, and the sample was evaluated as acceptable (indicated by "◯" in the table). In addition, other states were regarded as disqualified (indicated by "x" in the table).

[Preparation of composition]
The raw materials contained in each composition of Examples and Comparative Examples were as follows. Each component was weighed so as to have the mass described in the table below, and mixed at 25° C. for 15 minutes with a three-one motor (Shinto Kagaku Co., Ltd.) to obtain a composition. The unit of each component in the table below is "parts by mass".

<Component (A)>
(A-1) A hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 X-40-9250: In the above formula (1), R ¹ and R ² are A partially hydrolyzed condensate of a mixture of alkoxysilane compounds, each of which is a methyl group and x=1 or 2, has a weight average molecular weight of about 7,000 to 14,000, and a kinematic viscosity at 25°C of 160 mm ² s ^-1 , manufactured by Shin-Etsu Chemical Co., Ltd. (A-2) Hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25° C. in the range of 21 to 90 mm ² s ⁻¹ and its comparative component KR-500: Formula (1 ), R ¹ and R ² are both methyl groups, a partial hydrolysis condensate of an alkoxysilane compound in which x is 1 or 2, a weight average molecular weight of about 1,500 to 2,500, and a kinetics at 25 ° C. Viscosity: 25 mm ² s ^-1 Shin-Etsu Chemical Co., Ltd., Comparative (1) KR-400: Partial hydrolyzed condensate of an alkoxysilane compound in which both R ¹ and R ² in the above formula (1) are methyl groups. (Contains a curing catalyst in the product), kinematic viscosity at 25 ° C. is 1.2 mm ² s ^-1 Manufactured by Shin-Etsu Chemical Co., Ltd. (Note that (B) is not added to the composition containing the raw material)
・Comparison (2) KC-89S: Partially hydrolyzed condensate of an alkoxysilane compound in which both R ¹ and R ² are methyl groups in the above formula (1), kinematic viscosity at 25°C is 5 mm ² s ^-1 Shin-Etsu Manufactured by Kagaku Kogyo Co., Ltd., Comparative (3) X-40-9225: A partially hydrolyzed condensate of an alkoxysilane compound of formula (1) in which both R ¹ and R ² are methyl groups, kinematic viscosity at 25°C is 100 mm ² s ⁻¹ Shin-Etsu Chemical Co., Ltd., Comparative (4) KR-401: Partial hydrolysis of an alkoxysilane compound in which R ¹ is a methyl group and a phenyl group and R ² is a methyl group in the above formula (1) Condensate (containing a curing catalyst in the product), kinematic viscosity at 25 ° C. is 20 mm ² s ^-1 (kinematic viscosity at 25 ° C. is 14 mm ² s ^-1 without a curing catalyst) manufactured by Shin-Etsu Chemical Co., Ltd. ( (B) is not added to the composition containing the raw material)
・Comparison (5) X-40-2327: Partially hydrolyzed condensate of an alkoxysilane compound of formula (1) in which both R ¹ and R ² are methyl groups (a curing catalyst is included in the product), 25 Kinematic viscosity at 0.9 mm ² s ^-1 at ° C. (Kinematic viscosity at 25 ° C. without curing catalyst is 0.6 mm ² s ^-1 ) manufactured by Shin-Etsu Chemical Co., Ltd. (Note that the composition containing the raw material does not add (B)).

<Component (B)>
(B) Organic aluminum compound and its comparative components DX-9740: Aluminum alkoxide compound, manufactured by Shin-Etsu Chemical Co., Ltd. Comparison (1) D-25: Organic titanium compound, manufactured by Shin-Etsu Chemical Co., Ltd. Comparison (2) D-220: 25% by mass 2-propanol solution of phosphoric acid compound, manufactured by Shin-Etsu Chemical Co., Ltd. Comparison (3) X-40-2309A: Phosphoric acid compound, manufactured by Shin-Etsu Chemical Co., Ltd.

<Component (C)>
(C) Hydrocarbon-based organic solvents with a boiling point temperature in the range of 100 to 165 ° C. and their comparative components Isononane (2-methyloctane): Boiling point 143 ° C. Reagent Comparison (1) Isohexane (2-methylpentane): Boiling point 60° C. Reagent/comparison (2) n-heptane: Boiling point 98° C. Reagent/comparison (3) Isooctane (2,2,4-trimethylpentane): Boiling point 99° C. Reagent/comparison (4) Isodecane (2-methylnonane): Boiling point 167°C Reagent/Comparison (5) n-decane: Boiling point 172°C Reagent.

Examples 1 to 8 in Table 1: The compositions containing the respective components (A) to (C) in the predetermined composition ratios of the present invention have good film-forming properties and antifouling properties. In addition, it was confirmed that it possesses a suitable range of dryness for construction. Furthermore, the composition according to the present invention was also excellent in wettability, weather resistance, and discoloration resistance.

On the other hand, Comparative Examples 1 to 5 in Table 2: In the composition using a hydrocarbon-based organic solvent having a boiling point outside the specific range of the present invention instead of (C) of the present invention, all of the compositions have film-forming ability. was inadequate. Especially in Comparative Examples 4 and 5, in which the boiling point range exceeds the upper limit of the range of the present invention, the wettability was also poor, and the dryness was also unsuitable for construction. Moreover, in Comparative Examples 1 and 2, in which the boiling point range is less than the lower limit of the range of the present invention, the dryness is also unsuitable for construction. Comparative Examples 6 to 10: Compositions using hydrolyzable group-containing silicone oligomers having viscosities outside the specific range of the present invention, in place of (A-2) of the present invention, exhibited problems other than drying properties and discoloration resistance. The results were poor in all of the properties, and it was not suitable for practical use. Comparative Examples 11 to 13: The compositions using condensation reaction catalysts other than organoaluminum instead of the present invention (B) are all poor in film-forming ability and weather resistance, and also have problems in discoloration resistance. There were many things. Comparative Examples 14 to 17: The content of (A) (content relative to 1 mass of component (C)) is within the specific range of the present invention, but the composition ratio of (A-1) and (A-2) is Compositions containing mixtures outside the specific range of the present invention exhibited poor film-forming properties and/or antifouling properties, and some also exhibited poor wettability. Comparative Examples 18 and 19: In a composition in which the content of (B) (content per mass of component (C)) is outside the specific range of the present invention, the content is less than the lower limit in Comparative Example 18. A good curing speed was not obtained. Therefore, the drying property was in a range not suitable for construction. In addition, in Comparative Example 19 in which the content exceeds the upper limit, the film-forming ability was poor, and the weather resistance and discoloration resistance were also poor. Comparative Examples 20 and 21: Compositions in which the content of (A) (content relative to 1 mass of component (C)) is outside the specific range of the present invention has poor film-forming ability and antifouling properties, and furthermore Some of them had poor wettability and weather resistance.

The film-forming composition of the present invention provides a cured film with excellent properties. The film-forming composition of the present invention is particularly suitable for forming thin-film coatings for imparting protective properties to metal surfaces, painted surfaces, or resin surfaces of automobile bodies and train cars. It is useful.

This application is based on Japanese Patent Application No. 2017-143606 filed on July 25, 2017, the disclosure of which is incorporated by reference in its entirety.

Claims (11)

Including the following (A) ~ (C),
The content of (A) below is 0.35 to 0.58 parts by mass, and the content of (B) below is 0.05 to 0.15 parts by mass, relative to 1 part by mass of (C) below. , a film-forming composition:
(A) a mixture of film-forming components containing the following (A-1) and (A-2) at a mass ratio of (A-1)/(A-2) = 1/26 to 1/36;
(A-1) Hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 (A-2) Kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 (B) an organoaluminum compound; and (C) a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165°C. The film-forming composition according to claim 1, wherein the boiling point of (C) is in the range of 110 to 155°C. 3. The film-forming composition according to claim 1, wherein (C) is a saturated aliphatic hydrocarbon solvent. Claims 1 to 3, wherein (C) comprises at least one selected from the group consisting of 2-methyloctane, 3-methyloctane, 4-methyloctane, 4-ethylheptane, and 2,3-dimethylheptane. The film-forming composition according to any one of . The film-forming composition according to any one of claims 1 to 4, wherein (B) contains an aluminum alkoxide compound. The film-forming composition according to any one of claims 1 to 5, which is used for forming a film on the surface of a steel plate or a painted steel plate. 7. The film-forming composition according to claim 6, wherein the steel plate or coated steel plate is an automobile body. Applying the film-forming composition according to any one of claims 1 to 5 to the surface of a steel plate or coated steel plate, volatilizing the (C) at room temperature or in a heated environment, and then wiping with a dry cloth. , or a method of forming a film, further comprising wiping with a damp cloth followed by wiping with a dry cloth. 9. The method of forming a film according to claim 8, wherein the steel plate or coated steel plate is an automobile body. A cured film obtained by curing the film-forming composition according to any one of claims 1 to 7. (A-1) a hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 100 to 250 mm ² s ^-1 ;
(A-2) a hydrolyzable group-containing silicone oligomer having a kinematic viscosity at 25°C in the range of 21 to 90 mm ² s ^-1 ;
(B) an organoaluminum compound;
(C) A method for producing a film-forming composition comprising mixing with a hydrocarbon-based organic solvent having a boiling point in the range of 100 to 165° C.,
The (A-1) and (A-2) are mixed at a mass ratio of (A-1) / (A-2) = 1/26 to 1/36,
The film-forming composition contains 0.35 to 0.58 parts by mass of (A-1) and (A-2) in total with respect to 1 part by mass of (C), and A method for producing a film-forming composition containing 0.05 to 0.15 parts by mass.