JP5075402B2 - Coating composition - Google Patents

Description

  The present invention relates to a coating composition applied to, for example, automobile painted surfaces. Specifically, the present invention relates to a coating composition that imparts water repellency and antifouling properties to a painted surface and has a short curing completion (curing) time.

Conventionally, for example, as a coating composition for forming a protective film on a painted surface of an automatic person, a coating component composed of a wax and a resin that protects the surface, a silicone oil component that provides a polishing effect, a dispersion of a surfactant and water, etc. Those containing components and those containing components that are cured by moisture in the air are known (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 2-185579 JP 2006-45507 A

  However, the silicone oil, which is a polishing component in the composition of Patent Document 1, has poor fixability, and it has been difficult to maintain aesthetics such as gloss over a long period of time. In addition, the wax contained as a film component in the composition is easily contaminated with smoke, exhaust gas, and the like, which are the main components of water red, which significantly impairs the appearance, and once adhered, it is difficult to remove the dirt. In order to maintain the aesthetic appearance, it was necessary to carry out complicated cleaning work with a regular cleaner wax or a water scrub cleaner. On the other hand, although the composition of patent document 2 can maintain an aesthetics over a long period of time, when a construction surface rains or falls on the construction surface before curing and the construction surface gets wet with water, a complete protective film cannot be formed. There was a problem. For this reason, at the construction site, after the coating composition is applied, it must be left indoors for several hours, and the waiting time until the next work is long, leading to deterioration in work efficiency.

  The present invention responds to the market need to maintain or restore the aesthetics of the painted surface with simpler maintenance. It can be efficiently applied to the painted surface and maintains water repellency and antifouling properties over a long period of time. It is an object of the present invention to provide a coating composition that can be applied.

In order to achieve the above object, the present invention is based on one or more organic solvents selected from aliphatic hydrocarbon solvents, petroleum solvents, aromatic solvents, alcohols and fluorine solvents, In the base,
(A) a moisture curable silicone resin;
(B) a reaction accelerator;
(C) a reactive silicone oil having at least one silanol group in the molecule;
The gist of the present invention is a coating composition containing

  In the coating composition of the present invention, it contains (a) a moisture curable silicone resin, (b) a reaction accelerator, and (c) a silicone oil having at least one silanol group at the molecular end. Efficiently water-repellent and antifouling properties can be created on the painted surface, and a beautiful glossy painted surface can be created. Even if water stains adhere, it can be removed by simple operations such as washing with water.

  Hereinafter, the coating composition of the present invention (hereinafter simply referred to as the composition) will be described in more detail. The composition of the present invention is applied, for example, to a painted surface of an automobile, and as a base for dissolving or dispersing the components in the composition to form a uniform coating film, an aliphatic hydrocarbon solvent, One or more organic solvents selected from petroleum solvents, aromatic solvents, alcohols and fluorine solvents are used.

  Examples of such organic solvents include aliphatic hydrocarbon solvents such as hexane, heptane, nonane, decane, and undecane, petroleum solvents such as mineral spirit, aromatic solvents such as benzene, toluene, and xylene, 1,1 , 2,2,3,3,4-heptafluorocyclopentane, HFE, ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, methyl nonafluoroisobutyl ether, methyl nonafluoroisobutyl ether, and the like. These solvents may be used alone or in combination of two or more.

  The composition of the present invention comprises a reactive silicon cone having (a) a moisture curable silicone resin, (b) a reaction accelerator, and (c) at least one silanol group at the molecular end in the base comprising the organic solvent. It is characterized by containing oil.

  The moisture curable silicone resin constituting the component (a) is, for example, a silicone alkoxy oligomer having a relatively low molecular weight that is blocked with an alkoxysilyl group represented by Si-OR at the molecular end, which will be described later (b). In the presence of a reaction accelerator as a component, a trialkoxysilyl group is hydrolyzed by moisture in the air to form a silanol group (Si—OH), and the silanol groups are condensed to form a siloxane bond (Si—O—). What has the property which forms Si) can be mentioned as a preferable thing.

  The moisture curable silicone resin having such properties is expressed by the following average composition formula.

R _m Si (OR ′) _n O _{(4-mn) / 2}
In the above formula, R is one or more groups selected from a substituted or unsubstituted alkyl group and an aryl group, and R ′ is an alkyl having a hydrogen atom and an ether bond having 1 to 4 carbon atoms. One or more groups selected from the group, and m and n are numbers satisfying the following relational expression.

0.5 ≦ m ≦ 1.8,
0.01 ≦ n ≦ 2.5 and 1 ≦ m + n ≦ 3
The addition amount of the moisture curable silicone resin is 0.1 to 30 parts by weight, preferably 1 to 15 parts by weight with respect to 100 parts by weight of the composition of the present invention. If the amount is less than 0.1 weight, a uniform coating film cannot be obtained, and if it exceeds 30 parts by weight, the wiping operation may be adversely affected.

  The moisture curable silicone resin is available as a commercial product, for example, KR-500 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd.), KR-510 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd.), X- 40-2327 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9225 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. These water-curable silicone resins may be used alone. In addition, two or more types may be used in combination.

  The reaction accelerator as component (b) is an alkoxysilyl group represented by Si—OR ′ contained in the moisture curable silicone resin as component (a) (wherein R ′ represents a hydrogen atom and a carbon atom number). 1 or 2 or more groups selected from alkyl groups having 1 to 4 ether bonds) are components that promote the hydrolysis and condensation reaction with moisture in the air, and the component (b) By containing, the crosslinking density of the said (a) component increases, hardening progresses and a hard film can be obtained.

  Examples of the component (b) having such effects include organometallic compounds including aluminum, titanium and tin, inorganic acids such as sulfuric acid, hydrochloric acid, acetic acid and phosphoric acid, potassium hydroxide and sodium hydroxide. An amine compound such as alkali, ammonia, diethanolamine, and triethanolamine can be used.

  The component (b) can be obtained as a commercial product. For example, D-20 (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd., containing titanium-based metal), DX-9740 (trade name) (Shin-Etsu Chemical Co., Ltd.) And X-40-2309A (trade name) (manufactured by Shin-Etsu Chemical Co., Ltd., containing phosphoric acid).

  (B) As addition amount of a component, 0.01-30 weight part is preferable with respect to 100 weight part of this composition, More preferably, it is 0.05-10 weight part. If the amount is less than 0.01 parts by weight, the reaction rate is slow, and thus the curability is low. If the amount exceeds 30 parts by weight, the antifouling property and the hardness of the coating film may be adversely affected.

  The reactive silicone oil having a silanol group represented by Si—OH at the molecular end, which is a component (c), is an effective component for improving wiping workability due to a lubricating effect, antifouling property, and water repellency. . Further, since the hydrolysis reaction in the condensation reaction process is not required, the condensation reaction is shortened, and as a result, it is effective for shortening the curing time.

  Component (c) can be obtained as a commercial product, and examples thereof include FK-9701 (manufactured by Shin-Etsu Chemical Co., Ltd.) and XC96-723 (manufactured by GE Toshiba Silicone Co., Ltd.).

  The amount of component (c) added is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the composition. This is because if it is less than 0.1 part by weight, water repellency and antifouling properties cannot be expressed, and if it exceeds 30 parts by weight, the antifouling property and the hardness of the coating film may be adversely affected.

  The composition of the present invention can also take a form containing fine powder for the purpose of forming a uniform coating film and improving workability such as application and wiping. The fine powder applied to the composition of the present invention preferably has an average particle size of 0.1 to 50 μm, more preferably 2 to 30 μm. When the average particle size of the fine powder to be added is less than 0.1 μm, there is a risk of difficulty in wiping work during construction, and when it is 50 μm or more, there is a risk of scratching the coating surface during wiping.

The fine powder can be obtained as a commercial product, for example, techpolymer (manufactured by Sekisui Plastics Co., Ltd., PMMA fine powder), flow beads CL2080 (manufactured by Sumitomo Seika Co., Ltd., low density polyethylene resin powder), MSP3000 (manufactured by Nikko Rica Co., Ltd., silicone resin powder) and Eposter S (manufactured by Nippon Shokubai Co., Ltd., melamine / formaldehyde resin powder).

  Moreover, in order to distinguish the applied part and the non-executed part, or to prevent wiping from being left behind, a fine powder added with a pigment can also be suitably used. Examples of commercially available products include tuftic beads AR650 series (manufactured by Toyobo Co., Ltd., crosslinked acrylic resin powder), Art Pearl C-200, C-300, C-400, C-800 (manufactured by Negami Kogyo Co., Ltd., Cross-linked urethane fine powder).

  The amount of fine powder added is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the composition. If the amount is less than 0.1 parts by weight, the effect of improving the wiping operation cannot be exhibited. If the amount exceeds 20 parts by weight, a uniform film may not be formed.

  The composition of the present invention can also take a form containing an organophilic layered clay mineral for the purpose of improving antifouling properties and decreasing the sedimentation rate of the fine powder in the composition. Examples of the organophilic layered clay mineral applied to the composition of the present invention include montmorillonite, mica and talc.

  Examples of the organophilic treatment method for the organophilic layered clay mineral include layer surface modification, end surface modification, or composite treatment thereof. Furthermore, examples of the organic treatment material include quaternary ammonium ions, anionic polymers, alkyltrialkoxysilanes, carboxyvinyl polymers, and highly polar organic solvents.

  The addition amount of the organophilic layered clay mineral is preferably 0.01 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, with respect to 100 parts by weight of the composition. When the amount of the organophilic layered clay mineral is 0.01 parts by weight or less, the effect of improving the antifouling property and the effect of preventing sedimentation is low, and when it exceeds 10 parts by weight, the wiping workability may be adversely affected. is there.

  In addition to the composition of the present invention, additives such as an ultraviolet absorber, a fragrance, and a surfactant can be blended within a range that does not adversely affect the antifouling effect.

  When the composition of the present invention is applied to the painted surface of an automobile, a method such as impregnating the composition with a sponge or cloth and rubbing the painted surface can be used. The application method can be selected according to the purpose and application, such as brush painting and coating with aerosol spray.

  The composition applied to the paint surface in this way is cured on the paint surface as the solvent in the base evaporates and the moisture in the air accelerates the reaction of component (a) (moisture curable silicone resin). A film is formed. Furthermore, the reactive silicone oil of component (c) is chemically bonded to the coating to give gloss and gloss to the coating surface, and even if water stains adhere, it can be removed by simple operations such as washing with water. It is.

  While showing the composition of each composition which concerns on Examples 1-3 shown in following Table 1 and Comparative Examples 1-4, antifouling property of each composition which concerns on Examples 1-3 and Comparative Examples 1-4 The water repellency was evaluated and the results were shown.

Evaluation of antifouling property (dirt removal property) A coating composition is uniformly applied with a urethane sponge to a white test piece defined in JIS K2396 (a polish coating agent for automobiles). A test piece is obtained by wiping the surface with a clean cloth after the surface has dried. After further drying for one day, the whiteness of each test piece is measured with a color tester HC-1 (manufactured by Suga Test Instruments Co., Ltd.), and the value is taken as the initial whiteness.

  As a contaminant, carbon black FW-200 (manufactured by Holbein Kogyo Co., Ltd., particle size: 0.002 to 0.028 μm) is uniformly dispersed in 5 parts by weight of water and 95 parts by weight of water. 0.5 MPa), and uniformly apply the surface of the test piece.

  The test piece is dried at 60 ° C. for 1 hour, baked with contaminants, and then allowed to cool to room temperature. After standing to cool, the contaminants adhering to the surface of the test piece are washed under running water while rubbing with a soft cloth such as gauze. This is one cycle. After removing moisture from the test piece, the whiteness is measured with a color tester HC-1 (manufactured by Suga Test Instruments Co., Ltd.) to obtain the whiteness after washing. The soil removability is evaluated based on the measured value when one test cycle is performed.

Evaluation criteria The soil removability is obtained by the following formula.
Dirt removal property = initial whiteness-whiteness after washing

The evaluation criteria for dirt removal are as follows.
○: 0 ≦ stain removal <1.0
□: 1.0 ≦ dirt removal property <3.0
Δ: 3.0 ≦ Dirt removal property <5.0
×: 5.0 ≦ Dirt removal

Durability of stain removal The evaluation of the antifouling property is evaluated by the stain removal property after 10 cycles. What are the evaluation criteria and evaluation methods? The same as the above-described dirt removal property.

Evaluation of Curing Time A coating composition is uniformly applied with a urethane sponge to a white test piece defined in JIS K2396 (a polish coating agent for automobiles) in an atmosphere of 10 ° C. A test piece is obtained by wiping the surface with a clean cloth after the surface has dried. Further, after curing at 10 ° C. for 30 minutes, water the test piece. Then, after leaving a test piece for 72 hours, water repellency is evaluated. The water repellency was evaluated according to the following criteria.

Evaluation criteria ○: Water repellent well □: Water repellent △: Slightly water repellent

Durability of water repellency After impregnating a sponge with each of the compositions prepared as examples and comparative examples in an automobile bonnet, it is uniformly applied and dried for 10 minutes. After drying, the surface was wiped with a clean towel (30 × 30 cm). Three months later, water was applied to confirm the water-repellent state. The water repellent state was evaluated according to the following criteria.

○: Water repellent well □: Water repellent △: Slightly water repellent ×: Little water repellent

  From Table 1, in each composition of Comparative Examples 1 to 4, the stain removability, the stain removability durability and the water repellency durability were □, Δ or ×. In each composition of 3, there is no △ or × for each evaluation item, both are evaluations of ◯ or □, excellent dirt removal and water repellency durability, and shorter curing time, Expected to improve efficiency.

Claims (4)

Based on one or more organic solvents selected from aliphatic hydrocarbon solvents, petroleum solvents, aromatic solvents, alcohols and fluorine solvents, in the base,
(A) a moisture curable silicone resin;
(B) a reaction accelerator;
(C) a reactive silicone oil having at least one silanol group at the molecular end;
A coating composition comprising: For 100 parts by weight of the composition,
0.1 to 30 parts by weight of component (a),
0.01 to 30 parts by weight of component (b),
0.1 to 20 parts by weight of component (c);
The coating composition according to claim 1, comprising:   3. The coating according to claim 1, comprising 0.1 to 10 parts by weight of fine powder having an average particle size of 0.1 to 50 μm with respect to 100 parts by weight of the composition. Composition.   The coating composition according to any one of claims 1 to 3, which comprises 0.01 to 10 parts by weight of a layered clay mineral that has been subjected to an organophilic treatment with respect to 100 parts by weight of the composition.