JPH05163460A - Method for forming urethane film - Google Patents

Abstract

PURPOSE:To provide a method for forming a urethane film having high film hardness without any problems even in its use for preventing glass products from scattering. CONSTITUTION:A coating prepared by partially substituting a polyol component with a polysilanol in a urethane coating containing the polyol blended with an isocyanate is used to coat glass products. The amount of the polyol component partially substituted with the polysilanol is preferably 5.0wt.%<=(weight of the polysilanol/weight of the polyol) <=50.0wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a urethane coating film which has a function of adding anti-scattering properties to glass products and has a high coating hardness.

[0002]

2. Description of the Related Art There are the following methods for preventing scattering of glass products. That is, a method of sticking a film of PET or the like to a window glass, a method of sandwiching a rubber-like polymer such as polybutyral between glass plates (for example, a windshield of an automobile), or a wire mesh is put in the glass plate. A method of applying a resin paint having rubber elasticity to a glass product.

[0003]

However, each of the above methods (1) to (3) has a problem that the shape is limited. Further, the above method, because the coating film is too soft,
There is a problem that a top coat (hard coat) is necessary. In view of the above circumstances, it is an object of the present invention to provide a method for forming a urethane coating film that does not have the above-mentioned problems even when used as a method for preventing scattering of glass products, and that has high coating film hardness. . The method for forming a urethane coating film according to the present invention can be applied to applications other than the scattering of glass products.

[0004]

In order to solve the above problems, the present invention uses a urethane coating composition obtained by blending a polyol and an isocyanate with a coating composition in which a part of the polyol component is replaced with polysilanol. To do. In the method for forming a urethane coating film according to the present invention, by forming the urethane coating film on the glass product with the above configuration, it becomes possible to form the anti-scattering film having high coating film hardness on the glass product.

The present invention will be described in detail below. The urethane paint used in this invention is basically the same as the conventional one in that it is prepared by mixing a polyol and an isocyanate. However, as the urethane paint, a paint in which a part of the polyol component is replaced with polysilanol is used. The point is the characteristic of the method of the present invention. The mixing ratio of the polyol and the isocyanate is the OH group of the polyol and the N of the isocyanate.
It is necessary to mix them so that they react with the CO groups without excess or deficiency. Generally, the number of NCO groups / OH groups is 1.00 to 1.00.
It is 1.05. The molecular weights of the polyol and the isocyanate are not limited at all, but the amounts required to exhibit the anti-scattering performance are necessary.

The types of polyol, isocyanate and polysilanol used in the present invention are not particularly limited, and the same ones as conventional ones can be used. Therefore, the number of functionalities is not limited, but when the molecular structure of the formed urethane coating film has a network structure as a whole, elongation of the coating film itself is lost and the anti-scattering performance is lowered. Use as a main component. Further, there is no problem even if a catalyst is added to accelerate the reaction between the polyol and the isocyanate.

[0007]

When the formed urethane coating film has a network structure as a whole with a network structure, the coating film itself loses its elongation and the anti-scattering performance deteriorates.
As the polyol and the isocyanate, a bifunctional one is used as a main component. However, the polyol alone has a low coating hardness and is not practical. Therefore, in this invention, this problem is solved by substituting a part of the polyol component with polysilanol.

The substitution amount of a part of the polyol with the polysilanol is preferably 5.0 wt% ≦ polysilanol weight / polyol weight ≦ 50.0 wt%. If the substitution amount of polysilanol is less than 5.0 wt%, it is difficult to achieve the effect of improving the coating film hardness, and if it exceeds 50.0 wt%, there is not much effect of improving the coating film hardness, and the elongation of the coating film decreases Because there is a tendency.

[0009]

EXAMPLES Next, examples and comparative examples will be described. Using the reagents shown below, paints blended under the conditions shown in Table 1 were glass plates (area 100 mm × 100 mm, thickness t = 4.0 m).
m), total film thickness: 50μm, 120 ° C ×
After baking for 60 minutes, evaluation was performed according to the following evaluation method. The results are shown in Table 2. The comparative example was the same as the example except that the polyol or the isocyanate was not applied as the top.

Reagent name Chemical name Bifunctional polyol A Octanediol Bifunctional polyol B Propylene glycol Bifunctional isocyanate Hexamethylene diisocyanate Bifunctional polysilanol diallylsilanediol Trifunctional polysilanol phenylsilanetriol Curing catalyst (organic Sn-based) Dibutyltin dilaurate [ Evaluation Items and Methods] Shatter Prevention Performance The samples prepared in Examples and Comparative Examples are dropped onto a concrete surface from a height of 1.0 m, and the weight% of glass remaining within a radius of 0.5 m from the drop point is measured. To do.
For example, when it is 100%, it means that the anti-scattering performance is very excellent. -Coating film hardness The pencil hardness of the coating film of the sample (based on JIS-K5401) is measured.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

Since the method for forming a urethane coating film according to the present invention is configured as described above, the obtained urethane coating film is basically soft and similar to the conventional urethane coating film. It has an excellent effect of preventing glass from scattering, has moderate hardness, and does not require a conventional top coat (hard coat).

Claims (2)

[Claims] 1. A method for forming a urethane coating film, which comprises coating a urethane coating composition obtained by mixing a polyol and an isocyanate with a part of the polyol component replaced with polysilanol. 2. The method for forming a urethane coating film according to claim 1, wherein a substitution amount of a part of the polyol component with polysilanol is 5.0 wt% ≦ polysilanol weight / polyol weight ≦ 50.0 wt%. .