JPS59213471A - Prevention of sagging - Google Patents

Abstract

PURPOSE:To prevent sagging by dispersing and compounding preliminarily magnetizable powder with a fluidable paint and magnetizing the powder before or after painting. CONSTITUTION:Magnetizable powder such as ferromagnetic metallic powder of iron, cobalt, etc. is preliminarily dispersed and compounded with a fluidable paint such as a paint of a soln. type contg. a solid resin or a high polymer compd. as a color developing material. The powder is magnetized before or after painting. Then the magnetizable powder is oriented by the magnetization to create a three-dimensional chain structure, by which the fluidity of the paint is retarded and sagging is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION More specifically, the present invention provides a method for preventing dripping in the application of flowable paints.

When a fluid paint is applied to a vertical surface, sagging may occur.
A painted surface of uniform thickness cannot be obtained. For this reason, there are methods to add thickeners to such paints to prevent dripping by volatilization of the solvent after painting and development of chicken tropism by standing still, and methods to prevent dripping by adding thickeners to such paints. Methods have been used to prevent sagging by thickening or gelling the liquid.

However, with this method, improving the anti-sagging properties increases the viscosity of the paint and significantly impairs its fluidity, which has the disadvantage of greatly impairing handling during paint manufacturing, paintability, and handling during painting. .

The present invention provides a means by which a paint can be manufactured without impairing the fluidity of the paint, and can prevent sagging that causes chicken tropism before and after painting, if necessary.

That is, when painting with a flowable paint, the present invention provides the following methods: (a) predistributing magnetizable powder into the paint, and (b) magnetizing the powder before or after painting. This is a method for preventing dripping, which is characterized by the following.

Fluid paints used in the present invention include, for example, solution-type paints containing a solid resin or polymer compound as a color vehicle, and monomers or oligomers containing ethylenically unsaturated bonds that are coated with heat or electromagnetic energy. These include solution-type or solvent-free coatings that are polymerized, solution-type or solvent-free coatings that are cured by epoxy resins, polyurethane resins, silicone resins, or other reactions.

Further, the magnetizable powder used in the present invention includes, for example, iron, cobalt, nickel, or ferromagnetic metal powder containing these, chromium dioxide, acicular gamma ferric oxide, and acicular tri-tetroxide. Ferromagnetic metal oxide powders such as iron, or these ferromagnetic powders with commonly known inorganic or organic fillers or reinforcing agents, such as carbonate powder, carbon black, glass fiber or polyester. It can be mixed with or attached to chopped strands of fiber. As the ferromagnetic powder, acicular crystal powder having a large aspect ratio of powder particles is particularly preferred.

These magnetizable powders are mixed with the above-mentioned flowable paint in a non-magnetic state and, if necessary, uniformly dispersed using a fine dispersion mill such as a Dissilver, Pebble Mill or Attritor. let

The blending ratio of the magnetizable powder to the paint vehicle is 5 to 400% by weight as ferromagnetic powder, preferably 20 to 300% by weight.
Use % by weight. Magnetizable paints are formulated to provide appropriate viscosity and chicken tropism in consideration of convenience during manufacturing and painting. The viscosity can also be adjusted by changing the molecular weight and content of the color vehicle, and the type and amount of the solvent and plasticizer. Also,
Thixotropy can also be controlled by the blending of inorganic fillers, the addition of colloidal silica or other thickeners, the degree of pulverization of the powder in the paint, etc.

Coating methods include spraying, brushing, troweling, spreading coating using a bar coater, coating using a roll coater, discharging from a nozzle or slit, and other methods used with paints and cooling materials. is applicable.

The magnetic powder can be magnetized by bringing it into contact with or in the vicinity of a magnet made of ferromagnetic metal or ferrite, by an electromagnet whose core includes a ferromagnetic material, or by placing it in or passing through the core of an energized conductor winding. There is. It is particularly preferable that the magnetic flux density of these magnets is larger than the saturation magnetic flux density of the magnetic powder.

The magnetization of the paint is determined by a magnetic flux density of 50 to 15,000 in the paint container.
This can be achieved by placing Gaussian magnets close together. Magnetization during painting can be achieved, for example, by placing a magnet near the nozzle tip in a spray method. Also,
Magnetization after coating is possible by placing a magnet near the front or back surface of the material to be coated. When the material to be coated is a ferromagnetic material, the object of the present invention can also be achieved by magnetizing it in advance and coating it with the paint.

The mechanism for preventing dripping is thought to be that the magnetizable powder dispersed in the paint is magnetized and oriented, creating a three-dimensional chain structure that completely inhibits the fluidity of the paint. However, the present invention is extremely useful as a method for achieving both coating properties, ease of handling during manufacturing, and prevention of dripping. Next, the present invention will be explained in more detail with reference to Examples.

However, the present invention is not limited to these examples. Parts and percentages are by weight.

Example 1 115 parts of castor oil, polyoxy/propylene triol (
Obtained by adding propylene oxide to trimethylol pan. 40 parts of hydroxyl value 374), 20 parts of Moleculan-Bus 3A (Union Carbide), 350 parts of non-magnetized acicular gamma ferric oxide powder, and 250 parts of quartz powder with a weight of 325 amenus at room temperature for 5 hours. After kneading in a ball mill, 95 parts of Millione-1-M R (product of Nippon Polyurethane Industries, Ltd.) was added and kneaded for an additional 30 minutes to produce a self-leveling paint for building materials. This paint had good fluidity and was easy to pour from a ball mill into a filling container. Magnetic flux density 11. on the outer surface of the filled container. , 800
When a Gauss permalloy magnet was brought into contact with the paint to orient the magnetic powder in the paint, no fluidity was observed even when the container was tilted. Apply this paint to the vertical surface of the concrete wall for about 1 minute.
．． When applied with a trowel to a thickness of mm, it did not flow down after application.
It cured after about 1 hour at room temperature. The cured painted surface was smooth and had a uniform thickness.

Example 2, polyether triol (obtained by adding ethylene oxide to a ether with a molecular weight of 3.000 obtained by adding propylene oquinide to glycerin and carrying out ring-opening polymerization.Hydroxyl value 22.3) Add 4.5 parts of diphenylmethane-414'-diisonanate and 37 parts of dioctyl phthalate to 50 parts, stir and heat to 80°C.
A prepolymer having an incyanate content of 0.7% was prepared. To 42 parts of this prepolymer were added 58 parts of pre-dried non-magnetized acicular triiron tetroxide powder, 2 parts of Aerosil 200 (product of Nippon Aerosil Co., Ltd.), and 1°2
．． 4-) Add 0.1 part of remethylpiverazine and knead for 30 minutes in a planetary mixer. After defoaming, JISA575
It was filled into the polyethylene cartridge described in No. 7. A 70 mm long polyethylene nozzle with an 8 mm hole was attached to the tip of this cartridge, and an iron-core electromagnet with the north and south poles facing each other was attached to the nozzle, and when energized, the
Gaussian magnetic flux density is generated (the end of the magnet core is composed of NS poles with a diameter of 15 mm that cover the nozzle part, and has a length of 9 mm and a length of 5 mm).
0n-. ) When the air gun was used at a pressure of I Ky / cl + Jllll L + Lt, the entire amount was discharged in 27 seconds. When this liquid was applied to a vertical surface in the form of an 8-diameter string, no dripping or running down was observed until it hardened.

Comparative Example 1 Example 2. Then, when the electromagnet was not energized and an air pump was used to extrude it under a pressure of 1/-, the entire amount was extruded in 25 seconds. Connect the discharge liquid with a string of diameter 811+11 v5 t Δ
When I pushed it out on the F screen, it just hit 13.
) 1. At the time of curing, a flat hard material with a maximum thickness of about 2 ral was given. Also, objects attached to vertical surfaces
i. It was so noticeable that most of the paint that had been applied had flowed down before it had hardened.

Comparative Example 2 Example 1. Kneelant, a one-component, urethane-based sealant that is similar to the same, is a drip-free one-component sealant (Japan Polyurethane Industry ■ product)
When dispensed under the same conditions as in Example 1 (however, no electromagnet was attached), the entire amount was dispensed in 73 seconds.

Claims (1)

[Claims] When painting with a fluid paint, (a) magnetizable powder is dispersed in the paint in advance, and (b) the powder is magnetized before or after painting. , a method for preventing dripping featuring Koshichi.