JPS62102859A - Method for coating body sealer - Google Patents

Abstract

PURPOSE:To coat a body sealer having good sealing property and covering property by spraying the sealer with regulated kinematic viscosity and static viscosity into gaps as the body sealer. CONSTITUTION:The body sealer for filling the gaps of the steel sheets, etc., of a vehicle is obtained by mixing a plasticizer and an adhesion providing agent into a vinyl chloride resin or a vinyl chloride copolymer or their blend, and regulating the kinematic viscosity to <=2,000cps and the static viscosity to 15,000-70,000cps. The sealer is sprayed into the gap to fill the gap. Consequently, coating is easily carried out with good sealing and covering property, and a smooth coated surface can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of applying a body sealer to fill gaps in joints of, for example, steel plates of vehicles.

[Conventional technology]

A bead of body sealer is applied to the joints and joints of the steel plates and members of the 11 cars, filling in the gaps. On top of that, the next step is intermediate coating and top coating. Body sealer is used during storage after application, or during heating and drying of the paint film during the intermediate coating and top coating processes.

The viscosity should be high so that it does not sag. Therefore, when applying, it may penetrate into the gaps between seams and joints, causing
You need to push it in with a spatula, etc. This pushing operation scrapes off the body sealer on the edges of the steel plate, exposing the steel plate, which is unfavorable in terms of rust prevention.

Japanese Unexamined Patent Publication No. 57-180678 discloses a method of imparting sealing properties to gaps using a thermal flow effect, and Japanese Patent Application Laid-Open No. 59-131868 discloses a body sealer that self-penetrates into gaps to impart sealing properties. has been done.

Spray coating is generally known as a method for coating paints, vinyl chloride resin plastisol undercoats, and high viscosity liquids. JP-A-52-105!347 discloses a method in which a highly viscous liquid is heated within a spray gun or on the way to the gun to enable spraying.

[Problem that the invention seeks to solve]

Said Japanese Unexamined Patent Publication No. 57-180ft? The method disclosed in Japanese Patent Publication No. 8 and the body sealer disclosed in Japanese Patent Application Laid-open No. 1316/1988 are effective in sealing gaps, but are insufficient for covering the edges of steel plates at joints. It is.

When a conventional vinyl chloride plastisol is used as a body sealer and used for spray application, there are problems with scattering and the applied surface becoming earthworm skin, making it undesirable to use as a body sealer. Japanese Patent Publication No. 52-105347
The heating method disclosed in the publication is not an excellent method because there is a risk that the body sealer will gel and a considerable amount of heat is required for heating.

The present invention aims to eliminate the drawbacks of the conventional methods described above, and to provide a method for applying a body sealer that has good sealing properties, good covering properties, a smooth application surface, and easy application.

[Means for Solving the Problems] In order to solve the problems, the method of applying the poye sealer to which the present invention is applied is to apply an ofq agent to a vinyl chloride resin, a vinyl chloride copolymer resin, or a blend resin of these resins. A method of spraying a sealer mixed with an adhesion promoter to have a kinematic viscosity of 2000 CP5 or less and a static viscosity of 15000 to 70000 cps is sprayed into the gap.

The base resin of the body sealer is a single resin of vinyl chloride, a copolymer resin of vinyl chloride, or a blend thereof.The copolymer resin is, for example, vinyl chloride and vinyl acetate,
It is a copolymer with vinylidene chloride, acrylic ester, maleic anhydride, or maleic ester.

Furnativizers include, for example, butylbenzyl phthalate (BBP),
Phthalic diisodecyl (DIDP), Phthalic 2
Phthalic acid esters such as -ethylhexyl CD0F), phthalic acid esters, di-2-ethylhexyl adipate (DOA), butyl phthalyl butyl glycolate (BPBG), di-2-ethylhexyl sebacate (DO5), etc. Polyester-based plasticizers such as mellitic acid-based plasticizers can be used.

Examples of fillers used include calcium carbonate (CaCO3), clay, talc, bentonite, kaolin, zinc layer, titanium oxide, and silica. As the adhesion promoter, for example, acrylic, amine, or imine adhesives can be used.

[Effect]

According to the method of the present invention, since the body sealer has a low kinematic viscosity (corresponding to the viscosity during spraying) of 2000 cps or less, the body sealer can be easily sprayed during application. On the other hand, the static viscosity (corresponding to the viscosity after application) is 15,000
~70,000 cps, the leveling of the coated surface is good and there is no sagging during heating and drying.

According to an experiment, the kinematic viscosity of the body sealer is 2000CpS.
Otherwise, it will not turn into a spray. Even if the static viscosity is 2,000 cps or less, if the static viscosity is 70,000 cps or more, the leveling of the surface to which the body sealer is applied will be poor, resulting in earthworm skin. If the static viscosity is less than 15,000 cps, the body sealer will overlap and sag during heating and drying in the next step.

〔Example〕

Examples of the present invention will be described in detail below.

First, adjust the body sealer. Base resin (vinyl chloride or vinyl chloride copolymer), plasticizer (butylbenzyl phthalate, di2-ethylhexyl phthalate), filler (particle size 1.5 ga + calcium carbonate, particle size 0.0
7p, ttr i\lucium acetate), adhesive gamma agent (
amine type) in Table 1! 1! A body sealer is obtained by weighing and stirring and mixing them in a quantitative ratio (Wt$). The static viscosity of the obtained body sealer was measured using a BH type rotational viscometer, and the dynamic viscosity was measured using a capillary extrusion type viscometer. Your B
The H-type rotational viscometer rotates a rotor immersed in a sample slowly at a constant speed, measures the torque received from the sample, and converts it into viscosity. The latter type of capillary extrusion type viscometer measures the speed at which a sample passes through a capillary under a constant pressure and converts it into viscosity.

Example 1 of body sealers mixed in the ratio of weight in Table 1
The example shown in ~Example 5 is a sealer that has a kinematic viscosity of 2QOQcps or less and a static viscosity of 15,000 to 70,000cps, and is used in the method of applying the present invention. The examples shown in Comparisons 1 to 4 have either dynamic viscosity or static viscosity outside the above range, and are sealers to which the present invention is not applicable.

When each of the above body sealers was subjected to a heat-resistant flow test according to JIS K-6830, it was found that the heat-resistant flow (IIIll)
) is as shown in Table 1, which suggests that there is no risk of the body sealer sagging during heating.

Furthermore, each of the above body sealers is sprayed using a spray device. The spray device uses a known airless or air spray gun. In the experiment, coating was performed in the positional relationship shown in the figure. The gap d between flat steel plate l and L steel plate 2 is 1m.
Using the material that was spot welded and bonded together at positions PI and P2 with a gap of m open, the material was applied with a spray gun 3 from a distance of 50+ am from the gap at an angle of 45 degrees toward this gap. The pressure applied to the sealer by gun 3 is 3 kg/cm2.

As shown in Table 1, the sprayability at this time is generally good if the kinematic viscosity (viscosity during spraying) of the sealer is 2000 cps or less, but if it exceeds that, it becomes extremely poor. Also, for the finished appearance of spray coating, the lower the kinematic viscosity of the sealer, the better for both the degree of scattering and smoothness (leveling).

In order to check whether the sealing property is good or not, the L steel plate 2 is peeled off from the flat steel plate I, and the penetration distance of the body sealer is measured. That is, as shown in Table 1, which shows how much the body sealer penetrates into the gap between the flat steel plate 1 and the L steel plate 2, the lower the kinematic viscosity and the static viscosity, the longer the penetration distance, and the better the sealing performance.

Next, we conducted the following experiment to investigate the characteristics of multiple coatings. Apply body sealer in the same way as above to the board that has been electrodeposited with anti-rust paint. After preheating it, apply an intermediate coat of 20 gm and a top coat of 20 JLm, then dry. When the finished painted surfaces were visually inspected to judge whether they were good or bad, as shown in Table 1, all the examples to which the present invention was applied were beautiful.

The pressure applied to the sealer by the spray gun during application is as follows:
The pressure is relatively low, preferably 5 kg/cm2 or less; if it is higher than that, the body sealer may splatter.

Further, the coating film thickness is preferably 0.7 to 3.0 mm, and 0.7 to 3.0 mm.
If it is less than 7 mm, the steel plate edge portion is insufficiently covered, and 3
．． If it is thicker than 0+++a+, sagging may occur.

〔Effect of the invention〕

As explained above, in the method of applying the body sealer to which the present invention is applied, the viscosity of the sealer is set as described above, so that the sprayability is good and it can be applied over a wide area, so that the area to be sealed can be reliably sealed. , sealing properties and covering properties are also improved.

Since there is no need to touch up the body sealer by pushing it in, there is no need to worry about edge exposure, and by eliminating the touch up process, the work time can be shortened.
Eliminates sagging during drying and provides a beautiful coating finish.
Both the intermediate and top coats are beautifully finished.

(Margin below) Table 1 = Characteristics of body sealer Book flies in granular form without atomizing.

This is the parent diagram.

■ Flat steel plate 2 L steel plate 3 Spray gun d, gap

Claims (1)

[Claims] 1. Vinyl chloride resin or vinyl chloride copolymer resin, or
A sealer made by mixing a plasticizer and an adhesion promoter with a blended resin of these resins to adjust the kinematic viscosity to 2000 cps or less and the static viscosity to 15000 to 70000 cps,
A method for applying a body sealer, which comprises spraying the gap into the gap to fill the gap.