JPH02233772A - Solvent-free clear paint composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solvent-free clear coating composition that can be coated in thick films and provides a transparent coating film.

Conventional techniques and problems to be solved> Conventionally, when painting thick films, a small amount of anti-sagging agent is usually added to the paint in order to prevent the paint film from sagging. . ．． Anti-sagging agents include asbestos, inorganic fibrous materials such as sepio-lite (1), fine silicic anhydride (2), organic bentonite (3), surface-treated calcium carbonate (2), and polycarboxylic acid (5). , castor oil derivatives (H), polyamide waxes (H), and the like are known as typical examples.

However, although the inorganic anti-sagging agents (a) to (ii) have an excellent sag limit of several hundred microns, they have the problem of worsening the transparency of the resulting coating film.

On the other hand, the organic anti-sagging agents (e) to (g) above are. Although the transparency of the resulting coating film is not impaired, there are problems in that the sag limit is as low as several tens of microns and the particle size changes greatly depending on temperature.

In view of the current situation, the inventors of the present invention conducted extensive studies and discovered a solvent-free clear paint that can provide a transparent coating film and has a sag limit of several hundred micrometers, resulting in the present invention. It is.

Means for Solving the Problems> That is, the present invention provides: (i) 0.05 to 5 parts by weight of a coupling agent having a functional group, (ii) the above (i) based on 100 parts by weight of a coating film-forming resin; ) 0.5 to 5 parts by weight of an inorganic fibrous anti-sagging agent having a functional group that reacts with the functional group of component (iii) an organic anti-sagging agent having a functional group that reacts with the functional group of component (i). 0.01 to 5 parts by weight and (iv) the average particle size of the primary particles is 0.01 to 5 parts by weight. This invention relates to a solvent-free clear coating composition containing 0.5 to IO parts by weight of a fine powder inorganic pigment of 1 μm or less.

The reason why a coating film with good transparency can be obtained despite the high sag limit of several hundred μ by incorporating the components (i) to (iv) in the present invention is probably because (i) to (iv) are included in the present invention.
It is thought that this is because a network-like crosslinking reaction occurs between the components (iii), the opacity caused by the inorganic fibrous anti-sagging agent is alleviated, and as a result, a coating film with good apparent transparency is obtained.

The present invention will be explained in detail below.

The coupling agent (i) having a functional group used in the present invention is a crosslinking agent that crosslinks the inorganic fibrous anti-sagging agent (ii) and the organic anti-sagging agent (iii) described below in a network. Typical examples include zircoaluminate coupling agents and silane coupling agents.

The zircoaluminate coupling agent is, for example, a zirconium and aluminum compound having a partial structure represented by the following general formula: (wherein R. is an acyl group; R2 and R3 are organic groups having a reactive functional group). It is obtained by selectively bonding two types of organic ligands to a low molecular weight zircoaluminate skeleton containing .

Commercially available products are CAVCOMODA, C, C-1, F, M from CAVEDON CHEMICAL.
, M-1, S (The above uses an alcoholic solvent and has a functional group such as an amino group, a carboxyl group, a fatty acid, a methacryloxy group, or a mercabutane group.) :C
AVCO MOro APG, CPG, CPM, FPM
, MPG (the above uses a glycol solvent and has the same functional group as above), etc.

The silane coupling agent includes T-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, and N-(trimethoxysilyltriethoxysilane). monoethylenediamine, N-β-aminoethyl-T-
Typical examples include aminopropylmethyldimethoxysilane, β-aminoethyl-β-aminoethyl-T-aminopropyltriethoxysilane, and the like.

Inorganic fibrous anti-sagging agent used in the present invention (ii
) has a functional group that forms a bridge through chemical or physical bonding with the functional group of the coupling agent (i), specifically asbestos having a hydroxyl group on the surface;
Examples include sepiolite. As a commercially available product, Calidria Asbestos RG-2 is available from Union Carbide.
4 4. It is commercially available under trade names such as Milcon-S■.

Organic anti-sagging agent used in the present invention (iii
) has a functional group that forms a bridge through chemical or physical bonding with the functionality of the coupling agent (i). Typical examples include molecular weight polycarbonate and rubonic acid.

As the polycarboxylic acid, for example, castor oil is polymerized,
Examples include polymers with a molecular weight of about 103 to 106 neutralized with a metal salt or an N-containing organic compound such as an amine.

As a commercially available product, BYK-Mallinckodt Ch
Anti-Terror-2 from emiecheProdukte
03,204 (high molecular weight polycarboxylic acid), Talen 870 0-20 from Kyoeisha Yushi Kagaku Kogyo Co., Ltd.
, 8200-20, 8400-20, etc.

In the present invention, the coupling agent (i) is suitably blended in an amount of 0.05 to 5 parts by weight per 100 parts by weight of the film-forming resin, and within this range the sag limit is 100μ or more.
Moreover, a coating film with good transparency can be obtained.

In addition, it is appropriate to mix the inorganic fibrous anti-sagging agent (ii) in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the film-forming resin; if the amount is less than this range, the sagging limit will drop significantly. On the other hand, if the amount increases, transparency deteriorates, which is not preferable.

Organic anti-sagging agent (iii) is film-forming resin 10
It is appropriate to mix 0.01 to 5 parts by weight to 0 parts by weight; if it is less than this range, it is necessary to mix a relatively large amount of inorganic fibrous anti-sagging agent, resulting in poor transparency. On the other hand, if the amount is increased, the effect of improving the sag limit will not be observed, and the change in paint viscosity due to temperature changes will increase, which is not preferable.

Further, the average particle diameter of the primary particles used in the present invention is 0.
The fine powder inorganic pigment (iv) with a particle size of 1 μm or less is blended to have an anti-sagging effect and to improve the mechanical strength of the resulting coating film.

As the fine powder inorganic pigment (iv), precipitated halium sulfate;
Calcium carbonate is a typical example.

Commercially available products include Parifine BF1 and BF from Sakai Chemical Co., Ltd.
-20 (precipitated barium sulfate), MC-T from Maruo Calcium Co., Ltd., and Homocal DM (calcium carbonate) from Shiraishi Kogyo Co., Ltd. are commercially available.

The fine powder inorganic pigment (iv) must have an average primary particle diameter of 0.1 μm or less; if it is larger than this, the resulting coating film will have poor transparency and smoothness. In addition, it is appropriate to blend the fine powder inorganic pigment (iv) in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the coating film-forming resin; if the amount is less than this range, the mechanical strength of the resulting coating film will not improve. On the other hand, if the amount is too high, the resulting coating film will have poor transparency and gloss, which is not preferable.

The solvent-free clear coating composition of the present invention contains conventionally known solvent-free clear coatings, that is, liquid film-forming resins such as epoxy resins, acrylic resins, and polyester resins, and a curing agent for the resins as essential components. The above components (i) to (iv) are blended into a paint containing a modifier, a small amount of solvent, additives, etc. as necessary, and the viscosity is approximately 100.
~5000 centivoise (20°C) paint. In addition, in the present invention, it is particularly desirable that the film-forming resin be reactive with the coupling agent, which is the component (i).

The solvent-free clear coating composition of the present invention is applied to an object by conventional methods such as spray coating, brush coating, roller coating, etc., and a coating film is formed by drying at room temperature or by baking.

Effects of the Invention The solvent-free clear coating composition of the present invention has a high sag limit, so it is possible to coat a thick film, and a coating film with good transparency can be obtained despite the thickness.

Hereinafter, the present invention will be further explained with reference to Examples. In the examples, "parts" are expressed on a weight basis.

Examples 1 to 4 and Comparative Examples 1 to 4 The main component and curing agent component shown in Table 1 were thoroughly mixed immediately before coating, and the mixture was coated onto a glass plate using an applicator. The sag limit and the transparency of the coating film when dried at room temperature at the limit film thickness are shown in the blank at the bottom of Table 1.

As is clear from Table 1, the coating composition of the present invention had a high sag limit and was transparent.

On the other hand, Comparative Example 1 in which no fine powder inorganic pigment was blended, Comparative Example 2 in which no coupling agent was blended, and Comparative Example 3 in which no anti-sagging agent was blended had low sag limits. Furthermore, Comparative Example 4, in which an excessive amount of inorganic fibrous anti-sagging agent was blended, had poor transparency.

Claims (1)

[Scope of Claims] Based on 100 parts by weight of the film-forming resin, (i) 0.05 to 5 parts by weight of a coupling agent having a functional group, (ii) a functional group that reacts with the functional group of component (i). (iii) 0.01 to 5 parts by weight of an organic fibrous anti-sagging agent having a functional group that reacts with the functional group of component (i); iv) A solvent-free clear coating composition containing 0.5 to 10 parts by weight of a finely powdered inorganic pigment whose primary particles have an average particle size of 0.1 μm or less.