JPS5811566A - Thick intercoating paint for vehicle - Google Patents

Abstract

PURPOSE:To provide the titled paint having desirable coating film properties, applicability, and appearance of the coating film, and extremely excellent water resistance, by compounding fibrous magnesium silicate as a water-resistance improving agent. CONSTITUTION:A paint excellent especially in water-resistance is prepared by using fibrous magnesium silicate as an essential water-resistance improving agent in a thick intercoating paint for vehicle containing resin, solvent, pigment and water-resistance improving agent. The fibrous magnesium silicate has the chemical formula of (OH2)4(OH)4Mg8Si12O30.6-8H2O, and its amount is preferably 0.1-20pts.wt., especially 0.5-10pts.wt. per 100pts.wt. of the resin. The agent may be used in combination with other improving agents such as chlorine-containing silane-coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high film thickness intermediate coating paint for vehicles (hereinafter simply referred to as a high film thickness paint), and particularly to a high film thickness paint with excellent water resistance.

Conventionally, there is no paint of this type that combines film performance, workability, and finished appearance. Conventional high film thickness type paints normally used on vehicles, for example, for example, car intermediate paints, which are in large demand, are currently said to have a film thickness of 70μ or less that can be secured in multiple coats. There is. High film thickness type? 11
The reason why 1!4 cannot be used in large quantities in industries where finished appearance is important is that in order to obtain a high film thickness, a large amount of paint is applied to the object, which causes sagging (flowing) and bubbling (foaming), which deteriorates the finished appearance. Furthermore, in terms of workability, the paint contains a high proportion of solids, making it difficult to apply it evenly to the object being coated.Furthermore, in terms of film performance, chipping resistance and This is because it is extremely difficult to ensure impact strength. Therefore, the present inventors have developed a high film thickness type paint that eliminates all of these drawbacks, that is, a high film thickness type paint that can obtain a film thickness of around 500μ per coat and has extremely good workability and finished appearance. has already been provided. However, this paint also has the drawback of being slightly inferior in water resistance.

An object of the present invention is to provide a high film thickness type paint that has good film performance, workability, and finished appearance, and has extremely excellent water resistance.

The object of the present invention is achieved by incorporating fibrous magnesium silicate as a water resistance improver into a thick film coating. What is the fibrous magnesium silicate used in this invention? (OH2)4 (OH)4MgsSi+203o
- Means fibrous magnesium silicate having the chemical formula of 6-8 H2O. This substance is a well-known triclinic magnesium orthosilicate Mg 2 Sj 04, magnesium metasilicate Mg S! 03, talc or magnesium tetrasilicate Mg5Si40H・HO and magnesium trisilicate 2Mgo・3Si02・n H2O, etc., or
Magnesium tetrahydride disilicate in the form of plates, crystals, etc. H<M
g5Si20c+ and fine magnesium trisilicate2
Mg 0.3. Unlike hydrated magnesium silicate such as Si02-xH2O, it has a very porous tunnel structure. This structure not only has a different shape, but also has the property of adsorbing moisture.
It has the ability to absorb even 5096 water.

This property is contained in high film thickness type paints and does not change even after it is formed into a film. Therefore, it completely absorbs all the moisture introduced into the coating film, significantly improving its water resistance. This is a phenomenon that cannot be obtained with conventional magnesium silicate. It has been known that magnesium silicate coordinates with other chemical substances to impart thickening properties (thixotropy). Considering this property from the properties of high film thickness paints, it is known that it acts as a thixotropic agent to prevent sagging, etc. It works even with water containing salt and electrolytes.

On the other hand, the fibrous magnesium silicate used in the product of the present invention is no different from the thixotropes of these conventional high-film-thickness paints, has good viscosity thickening properties, and is a main component of high-film-thickness paints. Since it is well dispersed in m-thresin or a solvent, it is easy to make it into a paint. The blending ratio of the fibrous magnesium silicate is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the resin.

Next, a manufacturing method and other compounding agents for obtaining a good thick film coating using fibrous magnesium silicate, which is the essential part of this invention, will be described. First, any well-known manufacturing method can be suitably applied to the manufacturing method, and there are no particular restrictions. This typical manufacturing method involves blending two or more resin pigments, fibrous magnesium silicate, a solvent, and various additives such as antifoaming agents and antisettling agents as needed in a known stirrer such as a disper, and stirring and mixing. After that, the mixture is uniformly dispersed using a known dispersing machine such as a ball mill, sand grinder, or roll mill, and then defoamed to obtain a product.

The above pigment is a general term for extender pigments and color pigments, and specifically includes calcium carbonate, silica, alumina, iron oxide (including red iron oxide), aluminum silicate (clay,
kaolin, etc.), asbestos, hydrated magnesium silicate (
(including talc), barium sulfate, glass peas, zinc white and titanium oxide, preferably calcium carbonate,
These are silica, iron oxide, aluminum silicate, titanium oxide, and zinc white. When used, at least two or more of the above pigments are selected and used. What is desired in step 4 is to adjust the particle size distribution range of the pigment, and if this adjustment is incorrect, the finished appearance and coating performance may be impaired.

This particle size distribution is within the range of 0.001 to 70μ, and preferably 100μ of the total pigment.
Pigments distributed within the range of 0.001 to 5 μm are prepared and used in amounts of 70 parts by weight or more, and most preferably, pigments distributed within the range of 0.001 to 5 μm are used in amounts of 3 parts by weight.
A smooth coating film can be obtained by using a pigment with a small particle size, which is 5 parts by weight or more and a pigment distributed within the range of 30 to 70 microns, and a pigment with a large particle size, which is 25 parts by weight or less. As a method for adjusting the pigment distribution to this particle size, since soft pigments tend to become fine particles during the dispersion process using a known dispersion machine such as a roll mill or sand grinder, it is difficult to adjust areas with fine particle sizes. However, if the particle size is 5μ or more, it is preferable to use at least one hard pigment selected from among hard pigments such as silica, alumina, asbestos, and glass peas to make them fine in the dispersion process. It is effective to incorporate the pigment into the final product, the high film thickness type paint.In addition, the blending ratio of pigment in the high film thickness type four components is 100 to 50 parts per 100 parts of resin.
The amount is preferably 150 to 400 parts by weight. Although the pigments are generally as described above, the appearance, particle size distribution range, and blending ratio of each pigment that can be used in the present invention are shown in Table 1 below.

Table 1 Next, as the base resin that can be blended with the fibrous magnesium silicate used in this invention, any well-known paint resin can be used and there are no particular restrictions, but polyester resins, especially urethane-modified polyester resins, and oil-free alkyd resins are preferable. These include resins, urethane resins, phenol-modified resins, acrylic resins, etc., and the blending ratio thereof is 5 to 70 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the total high film thickness type paint.

Next, regarding the solvent, any known solvent can be used, but preferably at least two or more selected from the group consisting of a low boiling point solvent of 120°C or less and a high boiling point solvent of 120°C or more. Most preferably, the high boiling point solvent is used in an amount of 50 parts by weight or more per 100 parts by weight of the total solvent. Specific examples of low boiling point solvents are low molecular weight alcoholic solvents such as methanol, normal butanol and iso-butanol;
Specific examples of high boiling point solvents are glycol ethers such as ethylene glycol monoethyl ether and ethylene glycol monobutyl ether, Kent-based solvents such as 7-chlorohexanone and isophorone, and aromatic hydrocarbons. The blending ratio of these solvents is 20 to 100 parts by weight, preferably 30 to 80 parts by weight, per 100 parts by weight of the resin.

As mentioned above, the essential ingredients for this invention are the four components of fibrous magnesium silicate, resin, pigment, and solvent, but in addition to these components, antifoaming agents, leveling agents, and anti-settling agents may be added as necessary. When these are used in combination, an even more preferable high film thickness type paint can be obtained. Normally, if defoaming is complete, a smooth surface of the coating film can be obtained, so defoaming agents often also serve as leveling agents. It is an antifoaming agent such as an acrylic copolymer, and preferably a non-silicone antifoaming agent. Examples of anti-settling agents include fatty acid ester polymers, synthetic waxes, and silica-based anti-settling agents. If these compounding agents are used in too large a quantity, other physical properties will be impaired, so 0.01 to 0.01 to 100 parts by weight of the resin is used.
It is better to stay within the range of 5 parts by weight.

Next, the coating work viscosity of the high film thickness type paint of this invention is 1.00.
0 to 4.000 C, P, S, most preferably 2.500 to 3.500 C, P, S. In addition, the solid content is 60 to 100 parts by weight of the total height model paint.
90 parts by weight, most preferably 65 to 75 parts by weight. When painting, it is preferable to use a hot airless sprayer.

As mentioned above, the compounding agent and the method for producing a thick film type intermediate coating paint described in Iif have been shown as the most preferable example for obtaining the high film thickness type paint of the present invention. And there are no restrictions on the various compounding agents.

In this invention, fibrous magnesium silicate is mainly used as the water resistance improver, but any other well-known water resistance improvers can be used; specific examples include chlorine, vinyl, epoxy, Silane coupling agents such as mercapto type and amino type, and titanate type coupling agents such as monoalkoxy type and chelate type. Although not necessarily required, when used, they are used in combination with fibrous magnesium silicate. This blending ratio is 111100 for all fillings.
It is advisable to mix it in an amount of 0.5 to 2 parts by weight per part by weight.

(Example 1) U part of polyester (oil-free alkyd) resin with 60% non-volatile content by weight, 9 parts of melamine resin (11fI C41 agent) with 70% non-volatile content, and 0.0 parts of curing accelerator.
6 parts, 43 parts of silica, 1.1 parts of antifoaming leveling agent, 0.3 parts of fibrous magnesium silicate, and 10 parts of solvent.
Add 12 parts of other pigments and additives to the disper and add 15
The mixture was stirred and mixed for a minute, passed through a three-bar mill three times for dispersion, and then transferred to a defoaming tank and defoamed at a reduced pressure of about 70 cm* to obtain a high film thickness paint.

(Example 2) A high film thickness type paint was prepared in the same manner as in Example 1, except that the amount of fibrous magnesium silicate was 0.9 parts, and the amount of other pigments and additives was 11.4 parts. Obtained.

(Comparative Example 1) A high film thickness type paint was obtained in the same manner as in Example 1, except that 0.3 parts of magnesium tetrasilicate was blended instead of 0.3 parts of fibrous magnesium silicate.

(Comparative Example 2) Example 1 except that 0.3 parts of magnesium tetrahydride silicate was added instead of 0.3 parts of fibrous silicic acid and magnesium.
A high film type 4 paint was obtained in the same manner as above.

As described above, in order to examine the performance of the high film thickness type paint obtained in Example 1.2 and Comparative Example 1.2, the present Example and Comparative Example were individually applied to iron plates that had been previously coated with anionic electrodeposition or cationic electrodeposition. After applying 150μ of the obtained high film thickness type paint and setting it for 2 minutes, it was heated for 10 minutes in a furnace maintained at 100°C to 110°C.
Baked for a minute and allowed to cool to room temperature. After that, apply 35μ of normal intermediate paint, set for 7 minutes, and heat to 120°C.
After baking for 30 minutes in a furnace maintained at Thereafter, 35# of ordinary topcoat paint was applied, set for 7 minutes, baked in a furnace maintained at 120°C for 30 minutes, and allowed to cool to obtain a test piece. This test piece has the required sagging film thickness, armpit film thickness, airless sprayability, and
Smoothness, chipping resistance, salt spray tests, etc. were conducted, and all showed good properties.

Next, in order to check the adhesion of the coating film on the test piece, apply an NT cutter (NT cutter S!!! A type) to the coated surface of the test piece.
Apply vertically to reach the substrate.

Draw 11 parallel lines with an interval of 2.0 to 2.3 ms, and draw 1 parallel line with an interval of 2, 0 to 2.3 parts orthogonal to those parallel lines.
Draw one line, draw 100 squares surrounded by four straight lines, and apply adhesive tape (Nanoin industrial cellophane tape) to this area by holding one end of the adhesive tape and pulling it sharply upward to separate it from the test piece. Peel off the tape and remove the paint film in the square.
When the number of samples with 0% or more remaining was investigated, the test results listed in Table 2 below were obtained.

In addition, regarding the adhesion after water deterioration, the above test heather was
Immersed in distilled water at 0 ± 1℃ for 240 hours, and after taking it out
Adhesion was evaluated after a period of time.

Table 2 *After immersion at 40°C for 240 hours As is clear from the above and Table 2, this invention satisfies all the performances required for high film thickness type paints, and in particular has excellent water resistance. We offer high film thickness paints.

Patent applicant: Aisin Kako Co., Ltd.

Claims (1)

[Scope of Claims] (11) In a high-film intermediate coating for vehicles containing at least a resin, a solvent, a pigment, and a water resistance improver, the water resistance improver may be partially or completely fibrous. The high film thickness medium rI!tIi for vehicles, characterized in that it is made of magnesium silicate.
fee. (2) The blending ratio of fibrous magnesium silicate is 100% resin
The high film thickness type intermediate coating paint for vehicle interiors according to claim 1, characterized in that the amount is 0.5 to 10 parts by weight.