JPH0469194B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride resin dispersion paint, and more specifically to a vinyl chloride resin dispersion paint which is made by blending a specific amount of a specific inorganic material into a vinyl chloride resin and which has excellent resistance to exposure and staining and can provide a surface coating film with good surface hardness. This invention relates to resin dispersion paints. Among synthetic resin-coated steel sheets, vinyl chloride resin-coated steel sheets can withstand bending, punching, deep drawing, etc., and can be coated with a thick film, so they have excellent weather resistance and corrosion resistance, and are expected to be used in a wide range of applications. There is. However, since it contains a plasticizer, there is a problem in terms of surface hardness, and to improve this, for example, the amount of plasticizer in the vinyl chloride resin dispersion paint can be reduced, a solvent can be used, or other types of resins such as acrylic resin can be blended. This is often done. However, for exterior applications, a thick coating (100 to 300 μm) is required for the purpose of imparting weather resistance and corrosion resistance, and the use of solvents such as those mentioned above, or blending of other resins, causes underarm (paint blistering) during baking after painting. ), which causes the problem that a uniform coating film cannot be obtained.Furthermore, when exposed outdoors, vinyl chloride resin coatings tend to attract dust and dirt, making them easily contaminated and deteriorating their aesthetic appearance (exposure contamination). Therefore, by taking advantage of the advantages of ordinary thermoplastic vinyl chloride resin dispersion paints, it can be used as is for exterior applications, and improves the surface hardness of the paint film without impairing painting workability or film performance. It would be of great benefit to the industry if a dispersion type paint could be obtained that could provide a coated surface with excellent resistance to exposure and contamination. The vinyl chloride resin dispersion paint contains granular inorganic material having a particle size of 3 to 100μ and a Mohs hardness of 2 to 14 at a ratio of 10 to less than 100 parts (parts by weight) per 100 parts of vinyl chloride resin. We have completed the present invention after discovering that a vinyl chloride resin dispersion paint meets the purpose of the invention very well.The dispersion paint of the present invention is usually applied to pre-coated steel sheets and has excellent weather resistance, corrosion resistance, The vinyl chloride resin dispersion used as a base in the present invention has excellent processability, chemical resistance, moisture resistance, etc., has a high surface hardness, is difficult to scratch, and can provide a coating film with excellent resistance to exposure and contamination. The paint may be either a conventional plastisol in which vinyl chloride resin powder is dispersed in a plasticizer or an organosol partially dispersed in a solvent or blended with various resins.However, it is preferable to use vinyl chloride paste resin 100, for example. This is a general plastisol consisting of 30 to 70 parts of plasticizer, 3 to 6 parts of stabilizer, 5 to 30 parts of color pigment, and 0.5 to 1 part of additive (each part by weight). In terms of storage stability of the formulation, the paint viscosity is type B viscosity, and V ₃₀ =
1000~8000cps is desirable. This vinyl chloride resin dispersion paint is thermoplastic and is distinguished from thermosetting paints containing a curing agent. The inorganic material used in the present invention is a granular inorganic filler having a Mohs hardness of 2 to 14 and an average particle size of 3 to 100 microns. Examples of such inorganic materials having a Mohs hardness of 2 to 14 include CaO, CaCO ₃ , MgO, SiO ₂ ,
There are various materials whose main components are Al ₂ O ₃ , SiC, CaSO ₄ , etc. alone or in mixtures, among them CaO, CaCO ₃ , MgO, SiO ₂ , and others with a Mohs hardness of 6 to 13.
Gypsum, heavy carbon, glass, quartz, gay sand, alumina, silicon carbide, and the like whose main components are Al ₂ O ₃ or SiC alone or in a mixture are particularly preferably used. The particle size of the granular inorganic material also depends on the film thickness of the coating film, but when considering the normal coating film thickness (100 to 300μ), the average particle size in the present invention is 3 to 100μ.
It is necessary that This is because if the particle size is too small, the object of the invention will not be achieved, and if the particle size is too large, exceeding 100 μm, a uniform coating will not be obtained. Also, the amount of this substance mixed into the base paint is 10~
Selected to be less than 100 PHR (number of parts per 100 parts of vinyl chloride resin). In order to increase the surface hardness, it is desirable to increase the amount of filler as much as possible, but if too much is added, it will not be possible to obtain a uniform coating during continuous coating work, and it will also be detrimental to the exterior surface in terms of coating film performance. become inappropriate. Therefore, the upper limit is limited to about 100 PHR. On the other hand, if the amount of the filler is less than 10 PHR, it is not desirable because the reinforcing effect of the filler cannot be obtained. The mineral filler and paint can be mixed using a conventional high-speed stirrer and stored as a mixture, or the mineral filler can be mixed into the paint just before painting. If thoroughly mixed, the vinyl chloride resin dispersion paint will not settle in a short period of time since it has viscosity. (When storing, it is particularly preferable to use a base sol paint with a high viscosity relative to sedimentation properties and a filler with a specific gravity of 3.0 or less.) When compared to a film, when the amount of granular inorganic material is large, the gloss tends to decrease, but the feel of the film is marketable and does not pose any problem. In addition, the coating film has better moisture permeability than ordinary sol coatings without impairing processability. The present invention will be explained below with reference to Examples. Examples 1 to 16 Each granular inorganic material listed in the table was added to Vinisol 1000 OX-20 White (exterior plastisol manufactured by Nippon Paint Co., Ltd.) in the amount shown in the table (vinyl chloride resin 100
(amount per part) and mixed uniformly using a high-speed stirrer to obtain a PVC sol paint containing granular aerogenous material. A dry film thickness of 3 ml undercoat for bisol chloride (epoxy-modified acrylic resin) was applied to a galvanized steel plate (thickness 0.27〓) that had been pre-treated with Granozin 46 (a zinc phosphate treatment agent manufactured by Nippon Paint Co., Ltd.). ~5μ
Paint with a natural coater and bake for 60 seconds to reach a maximum temperature of 200℃. Next, the above-mentioned PVC sol paint containing granular inorganic material was applied to a dry film thickness of 200μ using a reverse coater, and baked so that the maximum temperature reached by the material was 200°C to obtain a steel plate coated with PVC resin containing granular inorganic material. . The coating performance of the obtained coated steel sheet is shown in the table.

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Claims (1)

[Claims] 1 Plastisol or organosol of vinyl chloride resin is added with an average particle diameter of 3 at a ratio of 10 to less than 100 parts by weight per 100 parts by weight of vinyl chloride resin solid content.
A thermoplastic vinyl chloride resin dispersion paint for pre-coated steel sheets containing a granular inorganic material with a Mohs hardness of ~100μ and a Mohs hardness of 2 to 14.