JP2750897B2 - Anti-fouling agent for painted surfaces of automobiles - Google Patents

Description

The present invention relates to an antifouling agent for painted surfaces of automobiles, and more particularly to a painted surface of automobiles characterized by forming a highly durable coating film having excellent antifouling properties. For a stain inhibitor.

《Prior art》 Since the painted surface of an automobile is constantly exposed to rain, soot, dust, etc., dirt easily enters the interior of the painted surface. Since it is difficult to remove by washing with water or the like, the appearance is significantly impaired. Therefore, a long-lasting antifouling agent having excellent antifouling properties has been desired.

From such a viewpoint, various polishing agents mainly composed of wax, silicone oil, a solvent and the like have been used. Furthermore, metal alkoxides such as Si, Ti and Zr (see JP-A-1-113475), moisture-curable organic polymers (see JP-A-63-213575), and mixtures of organoalkoxysilanes and metal alkoxides (see Kaisho 63-8117
No. 6, or a silicone resin or the like is applied as it is or diluted with a solvent to form a film.

However, polishing agents mainly used for care for the purpose of protecting painted surfaces of automobiles include wax,
Consisting of components such as silicone oil and solvent, it is a sticky film that easily absorbs dirt, and even if it can prevent dirt, it only adheres to the painted surface, so it is persistent. It has disadvantages such as poorness.

Also, conventional polishes are poor in heat resistance due to their thermoplasticity, and in the bonnet where the surface temperature is high and in summer, the coating on the painted surface softens and adsorbs dust and dirt, making the appearance significantly worse. .

Therefore, by applying a metal alkoxide, a moisture-curable organic polymer or a silicone resin as it is or after diluting with a solvent, the antifouling property and the durability thereof are improved more than the above-mentioned polishing agent. However,
In these cases, there is a drawback that it is difficult to form an optimum film on the painted surface of an automobile. That is, when diluted with a solvent, it has no viscosity, so that it cannot be appropriately used for an automobile painted surface having various shapes. For example, in a vertical surface, the upper film is thin because it flows downward, and the lower film is thin. There is a problem that the film becomes thick. In addition, it is difficult to adjust the amount of application when applying by impregnating the applicator, and there is a difference in film thickness depending on the application place and the application work. Penetrates into the film, and where the film thickness is small, the film is removed by car washing or the like, and the durability is reduced.

Therefore, a clean place and a dirty place appear depending on the place, and the case may be rather ugly.

On the other hand, when the film-forming component is applied without being diluted with a solvent, it has an appropriate viscosity, but it is difficult to apply the film uniformly and thinly, and the film thickness is generally large. Therefore, even if dirt does not invade until it is completely cured, cracks occur in the summer or at the bonnet where the surface temperature becomes high, and the appearance deteriorates. Further, JP-A-63-2135
In the moisture-curable organic polymer described in No. 75, since the metal alkoxide and the organic resin are reacted at a high temperature, they have a disadvantage that they gel during the reaction or have poor storage stability after the reaction. I have. In addition, the mixture of organoalkoxysilane and metal alkoxide described in JP-A-63-811768 cannot be used in the prior art because the organoalkoxysilane evaporates after coating so that an effective film thickness cannot be obtained and the water repellency is poor. Soils have many disadvantages.

<< Problems to be Solved by the Invention >> Although many film-forming components having an antifouling effect as described above are known, a film which can be applied thinly and uniformly by ordinary consumers and has an excellent antifouling effect. Is not yet known.

For example, although an example of using a moisture-curable silicone-containing composition for antifouling and polishing a painted surface of an automobile has been conventionally known, it has not yet achieved a sufficient antifouling property. The inventors of the present invention have studied the properties required of a moisture-curable silicone-containing composition necessary for a film formed by antifouling properties to have excellent antifouling properties. (Smoke, rain, dust, oily, and water-based stains). (2) Adhesion to the substrate without being affected by traces of automobile polishes remaining on painted surfaces of automobiles. (3) Harden reliably by moisture in the air to form a uniform and dense coating. (4) Hardness is required to be equal to or higher than that of automobile paint (2H or higher in pencil hardness). (5) (6) Excellent weather resistance (7) Good storage stability (8) Produces a colorless and transparent coating (9) Used for automotive polishes Properties such as being able to be diluted with a solvent that does not damage the paint film In reaching the finding present invention that it is sufficient.

Therefore, an object of the present invention is to allow ordinary consumers without special knowledge to apply by the same operation as conventional car wax, and to easily and reliably maintain excellent antifouling properties for a long period of time. Another object of the present invention is to provide an antifouling agent for a painted surface of an automobile.

<< Means for Solving the Problems >> The above object of the present invention is achieved by a general formula 0.5 to 50.0 parts by weight of an organopolysiloxane represented by the following, 100 parts by weight of a mixture of an organohydrogenpolysiloxane and a vinylorganopolysiloxane is subjected to an addition reaction in the presence of 10 to 200 parts by weight of a volatile silicone oil, and a solid formed. Silicone fine powder obtained by pulverizing powdery products
Stain on automobile painted surface characterized by uniformly dispersing each component of 5.0 to 50.0 parts by weight, 0.005 to 10.0 parts by weight of curing catalyst and 25.0 to 94.0 parts by weight of organic solvent so that the total amount becomes 100 parts by weight. Achieved by inhibitors.

In the present invention, any moisture-curable organopolysiloxane having the above-mentioned characteristics (1) to (9) may be used.
Although it can be used as the first component, the one represented by the general formula (I) is particularly preferable.

(I) In the formula, R ¹ and R ² are each a substituted or unsubstituted monovalent hydrocarbon group, and a and b are each a positive integer satisfying 1 ≦ a ≦ 1.7, 1 ≦ b ≦ 3 and 2 ≦ a + b <4. Is a number.

Specific examples of R ¹ and R ^2, for example a methyl group, an ethyl group, a propyl group, a 3,3,3-trifluoropropyl group, phenyl group, butyl group, and a hexyl group or the like, in particular R ¹ Is a methyl or phenyl group, and R ² is a methyl or ethyl group from an industrial viewpoint.

The content of the organopolysiloxane in the antifouling agent of the present invention is preferably 0.5 to 50.0% by weight. If the content is less than 0.5% by weight, the durability of the antifouling property is short, and if it exceeds 50.0% by weight, not only the film thickness is increased, the workability is deteriorated, but also the curability is deteriorated.

Among the organopolysiloxanes represented by the general formula (I), the following general formula (Wherein, R is a methyl group or an ethyl group, x, y and z are respectively 0.5 ≦ x ≦ 1.7, 0 ≦ y ≦ 1, 1 ≦ z ≦ 3, 2 ≦ x + y
(Positive number satisfying + z <4) is preferred.

The second component of the present invention is a non-adhesive silicone fine powder obtained by subjecting a mixture of offorganohydrogenpolysiloxane and vinylorganopolysiloxane to addition polymerization in the presence of volatile silicone oil and then pulverizing the mixture. The components are added in an amount of 5.0 to 50 parts by weight to give the antifouling agent of the present invention an appropriate viscosity.

This allows the antifouling agent of the present invention to be thin and uniform regardless of differences in various shapes of painted surfaces, work methods or applicators, for example, vertical surfaces such as automobile doors and bonnets that undulate. Can be applied. After the application, it is easily removed by performing a simple wiping operation with the evaporation of the solvent, and the film made of the moisture-curable silicone-containing composition remains uniformly and thinly.

That is, by taking a liquid or paste-like or gel-solid antifouling agent on a sponge, spreading it thinly on the coated surface, and wiping it off when the surface is white and dry, it is cured by moisture in the air. A uniform and dense thin film having excellent antifouling property and excellent durability can be formed.

The organohydrogenpolysiloxane used in the second component contains at least 1.5 hydrogen atoms bonded to silicon atoms in the molecule on average, and the vinylorganopolysiloxane contains, on average, vinyl groups bonded to silicon atoms. Contains 1.5 or more molecules in the molecule. The mixture of these organohydrogenpolysiloxane and vinylorganopolysiloxane is a volatile silicone oil having a boiling point of 100 to 250 ° C. used in the addition polymerization.
Use 10 to 200 parts by weight for 100 parts by weight.

In the above addition polymerization, a generally used metal compound of Group VIII of the periodic table is used as a catalyst.
In particular, it is preferable to use a platinum catalyst.

The second component is contained in the antifouling agent of the present invention in an amount of 5.0 to 50.0% by weight.
It is preferable to include them. When the content is less than 5.0% by weight, the viscosity required in the present invention cannot be obtained, and when the antifouling agent of the present invention is applied to a vertical surface, the difference in film thickness between the upper part and the lower part becomes large. On the other hand, if the content exceeds 50.0% by weight, it is difficult to obtain a uniform paste or solid, which is not preferable.

The organohydrogenpolysiloxane and vinylorganopolysiloxane used in the second component may be cyclic, linear, branched, or the like. Examples of the organic group include a substituted or unsubstituted monovalent hydrocarbon group, and a methyl group and a phenyl group are particularly preferable from an industrial viewpoint.

The non-adhesive silicone fine powder, which is the second component, imparts viscosity to the antifouling agent of the present invention by uniformly dispersing the same in a solvent, so that the antifouling agent is always thinly and uniformly adhered in a constant amount. Can be. Furthermore, when the content of the solvent evaporates and becomes less than a certain amount, it returns to a non-adhesive and smooth fine powder, and this fine powder can be easily removed by wiping, and later contains a moisture-curable silicone. Only the film composed of the composition can be left uniformly and thinly. By changing the mixing ratio of the fine powder, the product form of the antifouling agent can be freely changed from a liquid state to a paste state or a gel solid state.

The curing catalyst of the third component cures the organopolysiloxane of the first component by moisture, and is contained in the antifouling agent of the present invention in an amount of 0.005 to 10.0% by weight. Examples of the curing catalyst that can be used here include alkoxides, chelates, and homopolymers of Ti, Al, and Zr. These curing catalysts may be used alone or in combination of two or more.

Specific examples of the curing catalyst include, for example, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl titanate, triisopropoxy aluminum,
Aluminum tris (acetylacetone), aluminum tris (acetoacetate ethyl), aluminum diisopropoxy (acetoacetate ethyl), tetraisopropyl zirconate, tetrabutyl zirconate,
Examples include zirconium tetra (acetylacetone), zirconium tris (acetylacetone), and homopolymers thereof.

The content of the above curing catalyst with respect to the antifouling agent of the present invention is 0.
005% to 10.0% by weight is preferred. If the amount is less than 0.005% by weight, the curing rate of the first component is low, and if it exceeds 10.0% by weight, the reactivity to moisture in the air is too high to use.

In the present invention, various curing accelerators can be appropriately added for the purpose of adjusting the curability of the first component organopolysiloxane. Examples of such a curing accelerator include organic tin compounds such as dibutyltin diacetate, dibutyltin dioctate, and dibutyltin dilaurate;
Aminopropyltriethoxysilane, 3- (2'-aminoethyl) aminopropyltrimethoxysilane, 3-
Examples thereof include amines such as (2'-aminoethyl) aminopropylmethyldimethoxysilane, triethanolamine, and tetramethylammonium hydroxide; and various metal salts such as zinc octylate, cobalt octylate, and iron octylate.

The organic solvent as the fourth component in the antifouling agent of the present invention includes:
It is a component for dissolving the first component and the third component,
It is naturally necessary that these do not affect the coating film of the object to which the antifouling agent is applied. Such organic solvents have a boiling range
It can be appropriately selected from at least one selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, linear dimethylpolysiloxanes and cyclic dimethylpolysiloxanes at 80 to 250 ° C. But especially the boiling point is 80-25
0 ° C. aliphatic hydrocarbon solvent, aromatic hydrocarbon solvent having a boiling point of 150 ° C. to 250 ° C., linear dimethylpolysiloxane having a boiling point of 100 ° C. to 250 ° C., and a viscosity of 0.65 to 3.0 cs at 25 ° C. And a cyclic dimethylpolysiloxane having a boiling point of 100 ° C. to 250 ° C. and about 3 to 7 mer. These solvents may be used alone or in combination of two or more.

The content of these organic solvents in the antifouling agent of the present invention is
Preferred is 25.0% to 94.0% by weight. If it is less than 25.0% by weight, it is difficult to form a uniform coating film,
If the content exceeds 10% by weight, the film thickness becomes too thin, and the original antifouling property cannot be obtained.

In the present invention, in addition to the above first to fourth components, other silicone compounds can be used in a range that does not adversely affect the film properties.

The antifouling agent of the present invention is originally translucent white since the non-adhesive fine powder as the second component is merely dispersed without dissolving in the organic solvent as the fourth component. Transparency can be imparted by adding phenylpolysiloxane. The above-mentioned linear methylphenylpolysiloxane can be appropriately selected from known ones and used. The workability of coating can be improved by adding linear dimethylpolysiloxane in addition to this, but the viscosity is preferably 500 cs or less. It is desirable that the amount of these used be 10% by weight or less in the antifouling agent of the present invention, whereby the wiping operation can be improved.

In the present invention, by adding a reactive fluorine compound such as perfluoroalkylsilane as a moisture-curable film-forming component, water repellency and oil repellency can be enhanced, and the antifouling effect can be improved. In this case, the amount added is preferably 20% by weight or less in the antifouling agent. 20
Exceeding the weight% is not preferred because it is separated from other components.

Further, ultraviolet absorbers, antioxidants, coloring agents, fragrances and the like can also be used according to customary practices.

<< Effects of the Invention >> As described in detail above, the antifouling agent of the present invention can be easily converted from a liquid to a paste, a gel, or the like, and can also be made into a transparent form. In addition to being able to be adjusted according to the conditions, the workability is good, and the formed film is not only excellent in uniformity and transparency, but also can maintain the antifouling ability for a long time because it is a crosslinked cured film.

<< Examples >> Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

In each example, “parts” means “parts by weight” unless otherwise specified.

<Production of organopolysiloxane A> A mixture consisting of 108.8 parts of methyltrimethoxysilane, 18.0 parts of dimethyldimethoxysilane, 12.2 parts of diphenyldimethoxysilane and 12.0 parts of water was hydrolyzed, and then methanol produced as a by-product was distilled off under reduced pressure. Thus, an organopolysiloxane A as a first component was obtained.

<Production of Non-Adhesive Silicone Fine Powder B> 650 g of trimethylsilyl-endblocked dimethylmethylhydrodienepolysiloxane (average molecular weight 2,180, Si-H content 6.5 mol%) was placed in a planetary mixer having an internal volume of about 5 l,
Dimethylvinylsilyl end-blocked dimethylpolysiloxane (average molecular weight 930, vinyl group content 7.7 mol%) 550 g and octamethylcyclotetrasiloxane (boiling point 175 ° C) 1,2
00g was stirred and mixed. To the resulting mixed solution, 0.5 g of a 2% solution of chloroplatinic acid in 2-propanol was added, and stirring was continued at 70 ° C to 80 ° C for 2 hours to obtain a white powder. This powder was further pulverized to obtain a fine particulate non-adhesive silicone fine powder B as the second component.

The first component and the second component obtained as described above were blended as shown in Table 1 and stirred at room temperature until uniform, and the antifouling agents of Sample Nos. 1 to 5 of the present invention and Comparative Sample 1 were added. The samples thus prepared were subjected to the following tests for each sample to measure the stain prevention performance, water repellency and whiteness.

As Comparative Sample 2, a commercially available solid glazing wax for automobiles was used.

Example 1. Each sample was applied to a white painted steel plate for an automobile outer panel (using a melamine alkyd type baking paint). In the case of the sample of the present invention, the sample was applied to a sponge and then thinly applied. After the applied surface was white and dried, it was wiped up. In the case of Comparative Sample 1, the sample solution was soaked in a cotton towel, applied, and air-dried.

Further, in the case of Comparative Sample 2, it was applied to a sponge according to the instructions in the instruction manual, and then applied thinly. After the applied surface was white and dried, it was wiped up.

The specimen coated with each sample was allowed to stand outdoors exposed to direct sunlight, wind and rain, smoke, dust, etc., for 2 weeks, 1 month and 2 days.
After leaving for a month, wash each with a sponge and wipe off the moisture with a waste cloth.
The whiteness was evaluated by the following method.

(Testing method for stain resistance of painted surface)

The whiteness of the test plate that had not been subjected to any treatment was set as the standard, and the case where the visual whiteness was almost the same as the standard test plate was ○. △,
When the part was very badly stained, the result was x, and when the whole part was badly stained, the result was xx.

(Water repellency test method)

The test plate was tilted at 30 ° and water was allowed to flow through the test plate at a constant amount of water for 1 minute. Then, the time from when the flow of water was stopped to when the test plate ran out of water was measured. In this case, the test is performed immediately after applying a solid wax having excellent water repellency to a test plate as a glazing wax for automobiles, and the time until the water is drained is standard, and the time until the water is drained is longer than the standard time. The case where the time until the water was drained was rated as ○, the case where the time until the water was drained was equivalent to the standard time, and the case where the time until the water was drained was inferior to the standard time was rated as x.

(Whiteness test method)

For the untested coated plate, three predetermined whiteness values were measured with a colorimeter (trade name: TC-1 type, manufactured by Tokyo Denshoku Co., Ltd.), and the average was set to 100, and the whiteness of the treated test plate over time was measured. The degree of deterioration (%) of the degree was examined.

The results, as shown in Table 2, proved that the antifouling agent was remarkably superior in both antifouling property and sustainability as compared with the conventional antifouling agent.

Example 2 Every day, an automobile that runs widely in the Kansai area was used to evaluate the antifouling property and the water repellency of the coating.

 The evaluation was performed as follows.

(Test method for preventing stains on painted surfaces)

The entire vehicle was washed, and the entire surface was evenly and thoroughly cleaned with a commercially available cleaner wax to restore the original paint color and brightness of the vehicle.

With this state as the standard, when visual observation is performed, ○ indicates that the appearance is not substantially different from the standard state, Δ indicates that the part is slightly lightly soiled, X indicates that the part is heavily soiled, and X indicates that the entire part is dirty. Dirty was evaluated as XX.

This evaluation was performed for each part of the top plate, hood, trunk, and door of the automobile.

(Test method for water repellency)

Water was sprayed on the automobile in a shower form, sprayed on the painted surface, and the state of water droplets remaining on the painted surface was visually observed, and the evaluation was made as follows.

The state of the water drop of the commercially available solid wax immediately after the treatment or when the water drop is spherical: ○ When the water drop is slightly flatter than in the case of (1):
△ When the surface is partially wet: × When the surface is entirely wet: XX The results are as shown in Tables 3 and 4.

As is evident from the results in Tables 3 and 4, the antifouling agent of the present invention has an excellent protective effect on the coating film regardless of the position of the test part in the actual vehicle test, and its protection. It has been demonstrated that it has excellent sustainability.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koji Sakuta 2-13-1 Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Mitsuhiro Takarada Isobe, Annaka-shi, Gunma 2-13-1 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory

Claims (1)

(57) [Claims] (1) General formula (Wherein, R ¹ and R ² are each a substituted or unsubstituted monovalent hydrocarbon group, and a and b are respectively 1 ≦ a ≦ 1.7, 1 ≦ b ≦ 3 and 2 ≦
0.5 to 50.0 parts by weight of an organopolysiloxane represented by the following formula: a + b <4, a hydrogen atom bonded to a silicon atom in one molecule on average of 1.
The average number of organohydrogenpolysiloxanes containing 5 or more and vinyl groups bonded to silicon atoms in one molecule
100 parts by weight of a mixture with 1.5 or more vinylorganopolysiloxanes is subjected to an addition reaction in the presence of 10 to 200 parts by weight of a volatile silicone oil, and the resulting solid product is pulverized to obtain a fine silicone powder of 5.0 to 5.0. 50.0 parts by weight, 0.005 to 10.0 parts by weight of at least one curing catalyst selected from the group consisting of alkoxides, chelates of Ti, Al and Zr, and homopolymers thereof, and aliphatic having a boiling point range of 80 to 250 ° C. At least one organic solvent selected from the group consisting of hydrocarbons, aromatic hydrocarbons, linear dimethylpolysiloxanes and cyclic dimethylpolysiloxanes in an amount of 25.0 to 94.0 parts by weight; An antifouling agent for a painted surface of an automobile, wherein the agent is uniformly dispersed so as to be a part.