JPS6014970A - Formation of colored paint coated film on hard coating layer - Google Patents

Abstract

PURPOSE:To form a colored paint coated film having excellent adhesion to a hard coating layer by coating a specific pretreating agent on a hard coating layer which is formed on the surface of a base body and consists essentially of polysiloxane. CONSTITUTION:A hard coating layer which is a material to be painted consists essentially of polysiloxane. A silane or siloxane having a substd. or unsubstd. amino group bonded with a silicon atom via at least one carbon atom or an alkoxy group bonded with a silicon atom is diluted with a volatile siloxane and is coated as a pretreating agent for coating a synthetic resin paint on the hard coating layer. The coating film after coating is thoroughly dried at an ordinary temp. and is dried by a heat treatment and finally a colored paint coated film of acrylic lacquer or the like is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a colored coating film on a hard coat layer. The present invention relates to a method for forming a colored coating film that can form a coating film with excellent adhesion. .

In recent years, molded bodies made of transparent plastic have replaced transparent glass due to their lightness, ease of processing, and excellent lil+#
Because it has advantages such as impact resistance, it is used in a wide range of applications, such as lenses for eyeglasses and other optical devices, and window glass for buildings, trains, automobiles, and other transportation vehicles.

Although the above-mentioned Blastifuku has excellent dimensional stability and workability, it has the serious drawback that it is easily susceptible to abrasions and scratches due to its low surface hardness, and its transparency is easily impaired. Therefore, transparent plastic surfaces usually have
In order to improve the surface hardness, a hard coat layer is formed of a composition whose main component is, for example, melamine resin, polysiloxane, or crosslinked acrylic resin. Although the surface hardness of transparent plastics is significantly improved by forming these hard coat layers, when a paint is applied on the hard coat layer, the adhesion between the hard coat layer and the paint film is: , < , 2 have the problem of being easy to separate. 46, when the bar I/coat layer has polysiloxane as its main component, the surface hardness and scratch resistance are very good, but the water repellency and releasability are high, making it difficult to bond well with the paint film. This problem arises in that adhesion cannot be obtained and it is extremely difficult to form colored coating IIA on the surface.

In order to improve these problems, Japanese Unexamined Patent Publication No. 48-81
No. 921N: The publication discloses a method of coating a substrate in advance and then forming a heart coat layer. However, in this method, when performing the /\-decoat treatment,
If the dipping method is used for the dipping process, the underlying paint may be eroded, or the underlying paint components may be eluted.
The problem is that it tends to have an undesirable effect on the \-docoat treatment solution.

Furthermore, Japanese Patent Application Laid-Open No. 55-9438 discloses a method in which a treatment agent containing polysiloxane as one component is applied, 11 colors are applied, and then the entire body is hardened at once. However, this method requires a combination of painting lines during the treatment process and suffers from a lack of flexibility compared to methods in which a hard coat treatment agent is applied and then painted after curing. have.

An object of the present invention is to provide a method for forming a colored coating film that solves the above-mentioned problems and is capable of forming a coating film that has good adhesion even to a hard coat layer containing polysiloxane as a main component. It is to be.

The method of forming a colored coating film on a hard coat layer according to the present invention is to apply a colored coating film to a substrate having a hard coat layer mainly composed of polysiloxane on the surface of the heart coat layer through at least one carbon atom. It is characterized by coating a silane or siloxane having a substituted or unsubstituted amino group bonded to a silicon atom and an alkoxy group bonded to a silicon atom, and forming a coating film made of a synthetic resin paint after drying. be.

In the following, the invention will be explained in more detail.

The hard coat layer, which is the coated object of the present invention, has polysiloxane as its main component, and examples of such polysiloxane include cohydrolysates of alkyltrialkoxysilane and tetraalkoxysilane as its main component. Examples include those containing colloidal silica and a hydrolyzate of alkyltrialkoxysilane as main components.

At least one carbon atom used in the present invention
Substituted or unsubstituted amine 7 bonded to the silicon atom via
The silane or siloxane having an alcohol group and a silicon atom bonded to the silicon atom has a function as a pretreatment agent for applying a synthetic resin coating.

Such silanes or siloxanes include, for example, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, β-aminoethyltrimethoxysilane, β-aminoethyltrimethoxysilane, and β-aminoethyltrimethoxysilane.
-Aminoethyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-methyl-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxy Silane, N-β-aminoethyl-γ-
Examples include silanes such as aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane, and δ-aminobutyltrimethoxysilane, and siloxanes that are partially hydrolyzed condensates thereof.

The silane or siloxane can be applied to the hard coat layer by, for example, brush coating or spray coating in the same manner as in ordinary painting.

At this time, in order to facilitate application, the silane or hasiloxane may be diluted with an alcohol such as methanol, ethanol, propatool, or a volatile siloxane such as octamethylcyclotetrasiloxane. preferable.

Next, the silane or siloxane coating film is sufficiently dried, for example, at room temperature, and then heat-treated at 80-90''C for 10-15 minutes and dried.

As the synthetic resin paint used in the present invention, any room temperature curing or thermosetting paint can be used, such as acrylic lacquer, thermosetting acrylic resin paint, epoxy resin paint, melamine-alkyd resin paint, etc. However, it is preferable to use acrylic lacquer because it provides particularly excellent adhesion.

When using a room-temperature curing type paint, the synthetic resin paint described in Section 2 can be applied by, for example, brushing or spray painting.
Dry under normal conditions, such as leaving at room temperature for 1 to 6 hours.

In addition, when using a thermosetting paint, for example, it is applied by brushing or spraying, and after air drying, it is heated at 80 to 120°C for 2 hours.
Heat drying can be performed under conditions such as heat curing for 0 to 40 minutes.

Colored coating 11 formed on the heart coat layer by the following method
! I! has excellent adhesion to the hard coat layer due to the presence of the silane or siloxane layer.

The present invention will be explained in more detail below with reference to Examples. In the examples, all parts are by weight. Example 1 Polycarbonate resin (Lexan H3'0, trade name, manufactured by General Electric Company) was cut into a shape of 10 cm long, 10 cm wide, and 3 cm thick. Hard coat treatment agent (Tosgard 5) whose main component is polysiloxane on the surface
10. A hard coat layer was formed using Toshiba Silicone Co., Ltd. (trade name).

Next, on this hard coat layer, a solution of alkoxysilane according to the present invention having the composition shown in Table 1 (sample numbers 1 to 6) was applied using a brush, and then heated at 80°C for 1 hour.
It was dried by heat treatment for 0 minutes.

Further, an acrylic lacquer (trade name, manufactured by Kansai Paint Co., Ltd.) was applied onto this treated surface using a brush and dried at room temperature for 1 hour.

Each of the samples thus obtained was subjected to a base tape peeling test, and the coating film adhesion of each sample was measured. The results are also listed in Table 1.

In addition, for the base tape peeling test, cross-cut 100 squares by inserting 11 parallel lines vertically and horizontally at lam intervals on the coating surface, and then apply cellophane adhesive tape to that surface at 4=1.
After the tape was applied, the tape was peeled off and the number of squares that did not peel off out of 100 squares was calculated.

Comparative Example 1 Four types of samples (sample numbers 7 to 10) were prepared in the same manner as in Example 1, except that the composition of the treatment liquid applied to the hard coat layer was changed as shown in Table 1. did.

These samples were subjected to a base tape peel test in the same manner as in Example 1 to measure the adhesion of each coating film. The results are also shown in Table 1.

Example 2 A polycarbonate resin plate on which a hard coat layer was formed was prepared in the same manner as in Example 1.

On the other hand, three types of alkoxysilanes having the structural formulas shown in Table 2 were placed in a flask, and an equimolar amount of water to the alkoxysilane was added dropwise to the heated reflux to perform hydrolysis to obtain an alkoxysiloxane. . After completion of hydrolysis, 50%
% to prepare pretreatment solutions (sample numbers 11 to 16).

The same acrylic lacquer as used in Example 1 was applied and dried to form a coating film.

A base tape peel test was conducted on each coating film in the same manner as in Example 1. The results are also shown in Table 2.

Comparative Example 2 Three types of samples (sample numbers 17 to 19) were prepared by performing the same operations as in Example 2, except that the composition of the treatment liquid applied to the hard coat layer was changed as shown in Table 2. It was created.

These samples were subjected to a base tape peel test in the same manner as in Example 2 to measure the adhesion of each coating film. The results are also shown in Table 2.

Example 3 A polycarbonate resin plate on which a hard coat layer was formed was prepared in the same manner as in Example 1.

Next, the pretreatment liquid obtained in Example 2 (sample numbers 11 to IE
After pre-treating the hard coat layer using I) and applying an epoxy resin paint (Epomarine, trade name, manufactured by Kansai Paint Co., Ltd.), it was left to dry at room temperature for 16 hours to obtain a cured coating film. .

For each coating film, a base-grain tape peeling test was conducted in the same manner as in Example 1, and the adhesion of each coating film was measured. Ta.

Comparative Example 3 Using the treatment solution obtained in Comparative Example 2 (sample numbers 17 to 18), an epoxy resin paint was applied in the same manner as in Example 3 to obtain a cured coating film.

Next, a base tape peeling test was conducted in the same manner as in Example 3, and the adhesion of each coating film was measured.
The coating adhesion of all coatings was 0/100.

As is clear from the above results, according to the method for forming a colored coating film of the present invention, by using the pretreatment agent consisting of silane or siloxane according to the present invention, coloring with excellent adhesion to the hard coat layer can be achieved. It was confirmed that it was possible to form a coating film.

Claims (1)

[Claims] 1. For a substrate having a hard coat layer mainly composed of polysiloxane on the surface, on the surface m1 of the hard coat layer,
applying a silane or siloxane having a substituted or unsubstituted amino group bonded to the silicon atom via at least one carbon atom and an alkoxy group bonded to the silicon atom;
A method for forming a colored coating film on a hard coat layer, which comprises forming a coating film made of a synthetic resin coating after drying. 2. Claim 1, wherein the silane or siloxane is diluted with alcohol or volatile siloxane.
Coloring coating on the hard coat layer described in section n! ,! Formation method.