Compositions – Etching or brightening compositions
Reexamination Certificate
2001-01-16
2004-05-04
Chen, Kin-Chan (Department: 1765)
Compositions
Etching or brightening compositions
C252S079400, C252S182120, C428S447000, C524S379000
Reexamination Certificate
active
06730240
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a colored, transparent film-forming composition, which is applied onto a transparent substrate made, for example, of glass, plastics or the like and used as a window of buildings or a window of vehicles, including automobiles, thereby forming a uniform, clear, transparent colored film thereon. The invention also relates to a coating method of the composition and a method for removing or separating the resultant film. More particularly, the invention relates to a film-forming composition that is able to form a fashionable film on window glass of automotive vehicles and simultaneously serves to intercept UV light, and a coating method and removal method of a film obtained from the composition.
2. Description of the Prior Art
It is a usual practice to attach, on the window of buildings or automotive vehicles, a plastic film that is formulated with a UV absorber mainly for the purpose of absorbing UV light, or a coating formulated with a UV absorber.
However, the plastic film formulated with a UV absorber has the problems of the kind of color, the technique of attaching the film, and costs. In addition, further problems are involved in that it is troublesome to cut the film in a desired form with a difficulty in attaching to a complicated portion, air cells are apt to remain upon attachment of the film, and an adhesive is left after removal of the film, so that it has not been satisfactory for everyone to make ready use of it.
Where a film-forming composition containing a UV absorber is used, it is difficult to cure an applied film at room temperature, aside from color shading absorbed to the unevenness of coating, coupled with another deficiency that film strength after curing is low.
Further, a coated film, which is time-worn, has the vital drawback that it is difficult to remove or separate the coated film, and thus, a transparent substrate is very prone to be damaged on the surface thereof.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a colored, transparent film-forming composition, which is easy to handle and can yield an attractive, fashionable, transparent, colored film article and the film can be simply removed or separated from a substrate.
It is another object of the invention to provide a method for coating such a composition as mentioned above and also a removal method of a film obtained from the composition.
It is a further object of the invention to provide a colored, transparent, film-forming composition, which has a good leveling property without causing coating irregularities and can be cured at room temperature, can provide a film that is free of color shading, is high in film strength after curing, and is readily removable or separable after having been used.
It is still a further object of the invention to provide a coating method of the composition mentioned above and also a removal method of the film obtained from the composition.
According to the invention, there is provided a colored transparent film-forming composition which comprises (a) a reaction product of an epoxy group-containing alkoxysilane (a-1) and an amino group-containing alkoxysilane having active hydrogen therein (a-2), (b) an acid catalyst, (c) an alkali-soluble UV absorber, (d) at least one solvent selected from organic solvents having a boiling point of 100 to 150° C., and (e) a dye and/or a pigment. We have found that this composition has a good property, a good room temperature-curing characteristic, a good film strength characteristic, and good film peelability.
PREFERRED EMBODIMENTS OF THE INVENTION
The component (a) used in the invention is a reaction product of an epoxy group-containing alkoxysilane (a-1) and an amino group-containing alkoxysilane having active hydrogen (a-2) therein. The epoxy group-containing alkoxysilane (a-1) that is one of the constituents of the component (a) includes, for example, &ggr;-glycidoxypropyltrimethoxysilane, &ggr;-glycidoxypropylmethyldimethoxysilane or the like.
The amino group-containing alkoxysilane having active hydrogen (a-2), which is the other constituent of the component (a) includes, for example, &ggr;-aminopropyltriethoxysilane, N-(&bgr;-aminoethyl)-&ggr;-aminopropyltrimethoxysilane, N-(&bgr;-aminoethyl-&ggr;-aminopropylmethyldimethoxysilane and the like, of which N-(&bgr;-aminoethyl)-&ggr;-aminopropyltrimethoxysilane of the formula, H
2
N(CH
2
)
2
NH(CH
2
)
3
Si(OMe)
3
, is preferably used.
When N-(&bgr;-aminoethyl)-&ggr;-aminopropyltrimethoxysilane of the formula, H
2
N(CH
2
)
2
NH(CH
2
)
3
Si(OMe)
3
, exists as a constituent of the component (a), a hard film can be formed after curing and is suitable for application to automotive window glass. If the window is opened or closed, the film is unlikely to suffer scratches therein.
For the reaction between the constituents (a-1) and (a-2), the mixing ratio by weight between the epoxy group-containing alkoxysilane (a-1) and the amino group-containing alkoxysilane having active hydrogen (a-2) should preferably be 6:4 to 9:1.
More preferably, the ratio between (a-1) and (a-2) is in the range of 7:3 to 8:2.
When the ratio by weight of the epoxy group-containing alkoxysilane is larger than 9, curing of the resultant colored, transparent film-forming composition after coating proceeds slowly, with the surface hardness of the resultant film becoming low. On the other hand, when the ratio by weight of the amino group-containing alkoxysilane having active hydrogen is larger than 4, the film of the resulting colored-transparent film-forming composition exhibits poor weatherability.
The acid catalyst used in the practice of the invention may be any one, which acts as a catalyst when the hydroxyl group-containing hydrophilic alkoxysilane compound is hydrolyzed into a more reactive silanol at room temperature and subsequently undergoes polycondensation, e.g. sulfuric acid, nitric acid, phosphoric acid, para-toluenesulfonic acid and the like. Preferably, boron trifluoride is used.
The alkali-soluble UV absorber useful in the invention may be one selected from benzophenone compounds, benzotriazole compounds, and the like provided that they are alkali-soluble. Specific examples include 2,4-dihdyroxybenzophenone, 2,2′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and the like.
The alkali-soluble UV absorber is present in an amount of 5 wt % to 40 wt % of the colored, transparent film-forming composition. If the amount of the UV absorber is less than 5 wt %, the UV absorbing effect is lessened along with poor film separability. If the UV absorber exceeds 40 wt %, not only waterproofing and a resistance to chemicals such as an oil film cleaner and the like) are worsened, but also blooming undesirably occurs. From the standpoint of practical use, the amount preferably ranges from 15 wt % to 30 wt %.
The solvent used in the invention is made fundamentally of an alcohol solvent, a cellosolve solvent and a solvent having two or more functional groups, which, respectively, have a boiling point of 100 to 250° C. Typical examples include isobutyl alcohol, diethylene glycol diethyl ether, diisobutyl ketone, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether propanol and the like.
The propylene glycol monoethyl ether acetate includes 1-ethoxy-2-propyl acetate and 2-ethoxy-1-propylacetate, and it is preferred to use a mixture of not less than 90% of 1-ethoxy-2-propylacetate and not larger than 10% of 2-ethoxy-1-propylacetate.
The solvents used in the invention have a boiling point of 100 to 250° C. If the boiling point is lower than 100° C., the leveling property is worsened on coating, resulting in a poor film appearance. In contrast, when the boiling point exceeds 250° C., a coated film is unlikely to be dried.
Moreover, methyl alcohol, ethyl alcohol, methyl ethyl ketone or the like may be used in combination in order to increase solubilities of an acid catalyst and a dye.
The dyes and/or pigments used in the invention are selected
Arimoto Kunio
Maehara Yasuhiro
Nishida Hideo
Ohta Tatsuya
Sawamura Satoshi
Chen Kin-Chan
Flynn, Thiel. Boutell & Tanis, P.C.
Ishihara Chemical Co., Ltd.
Umez-Eronini Lynette T.
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