JPS61285269A - Paint composition - Google Patents

Abstract

PURPOSE:To obtain a paint composition having excellent heat-resistance and light-resistance, free of odor and toxicity and suitable for the coating of interior material, etc., by adding specific amounts of a chelating agent and a stabilizer containing at least a Ba-Zn-type compound metallic soap to a vinyl chloride resin. CONSTITUTION:The objective paint composition can be produced by compounding (A) 100pts.(wt.) of a vinyl chloride resin with (B) 6-21pts. of a stabilizer containing a Ba-Zn-type metallic soap as essential component and a Mg-Zn-type soap as an arbitrary component, (C) e.g. 0.2-7pts. of a chelating agent (e.g. polyphosphite-type organic phosphorous acid ester) and preferably (D) 30-100pts. of a plasticizer. USE:Vinyl sol paint for the coating of metallic plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a coating composition containing a vinyl chloride resin as a main component, such as a vinyl sol coating for metal plates.

[Background technology]

BACKGROUND ART Coating compositions containing vinyl chloride resin as a main component, such as vinyl sol coatings, have conventionally been used as topcoating coatings for metal plates used in the production of pre-coated metals and the like. However, these paint compositions contain dibutyl or dimethyltin mercaptide, which has an odor and toxicity, and toxic Cd-Ba-Zn metal soaps or lead salt compounds, which are mixed with vinyl chloride resin when exposed to heat or light. These coating compositions could not be used as top coats on metal plates when used as interior materials etc.

[Purpose of the invention]

The present invention provides a coating composition containing a vinyl chloride resin as a main component, which has no odor or toxicity, can be used for painting interior materials, etc., and has excellent heat resistance and light resistance. The purpose is to

[Disclosure of the invention]

In order to achieve the above object, the present invention provides a coating composition containing a vinyl chloride resin as a main component,
Among n-based and MgZn-based, at least Ba-Zn
It contains a stabilizer consisting of a composite metal soap of the type and a chelating agent that helps the function of the stabilizer, and the amount of the stabilizer added is 6 to 21 parts by weight per 100 parts by weight of the vinyl chloride resin. The gist is the characteristic coating composition.

This invention will be explained in detail below.

The vinyl chloride resin that is the main component includes not only vinyl chloride resin alone, but also copolymers such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene-vinyl acetate copolymer, etc. Resins used in common coating compositions, such as blends of vinyl chloride resin, styrene-acrylonitrile copolymer, and vinyl acetate resin, can be used.

These vinyl chloride resins are usually supplied as a base resin for paints by emulsion polymerization, but coarse powder produced by suspension polymerization may also be used in combination to reduce the viscosity of the paste resin. can.

Stabilizers are added to prevent the main component, vinyl chloride resin, from decomposing due to heat and light, and to prevent discoloration of the paint film and deterioration of electrical and chemical properties due to resin decomposition. As such a stabilizer, Ba
- A stabilizer consisting of a Zn-based composite metal soap, or a composite metal soap in which an Mg-Zn-based composite metal soap is mixed as necessary, is mixed with 100 parts by weight of a vinyl chloride resin (hereinafter referred to as "parts"). 6 to 21 parts of If the amount of stabilizer added per 100 parts of vinyl chloride resin is less than 6 parts, no effect as a stabilizer will be obtained, and if it exceeds 21 parts, bleeding or blocking will occur in the coating film. For example, vinyl sol paints for metal plates cannot form a film with sufficient resistance. When Mg-Zn-based composite metal soap is used in combination, the amount of Mg-Zn-based composite metal soap added in the stabilizer is 50% by weight (hereinafter referred to as "%") of the total amount of stabilizer.
) or less is preferable. However, Ba-
Even if Zn-based composite metal soap is used as a sole stabilizer, the effects of the present invention can be achieved. If the blending amount of the Mg-Zn composite metal soap exceeds 50% of the total amount of stabilizers, the heat resistance will decrease, resulting in poor workability, and moreover, this Mg-Zn composite metal soap is expensive. It also tends to be economically disadvantageous. Ba that can be used in this invention
-Zn-based or Mg-Zn-based composite metal soaps include stearic acid and lauric acid, which are generally used as stabilizers for vinyl chloride resins.

Examples include Ba, Mg, and Znn gold metal salts such as ricinoleic acid, naphthenic acid, and 2-ethylhexoic acid.

The coating composition of the present invention further contains a chelating agent as a stabilizing agent that assists the function of the stabilizer. As the chelating agent that can be used, it is preferable to use, for example, a polyphosphite-based organic phosphite alone or a combination thereof with a monophosphite-based organic phosphite.

Preferred polyphosphite-based organic phosphite esters include the following.

Hydrogenated 4,4'-isopropylidene diphenol phosphite, 4,4'-isopropylidene diphenol alkyl phosphite, 4,4'-butylidene bis(3- metal
6-tert-butylphenylditridecyl phosphite), distearylpentaerythritol diphosphite, Preferred monophosphite-based organic phosphite esters include the following.

Tris(nonylphenyl)phosphite, 2-ter
t-Butyl-α(3tert-butyl-4-hydroxyphenyl)-p-dimenylbis(p-nonylphenyl)
Phosphite, tricyclohexylphenyl phosphite.

The amount of the chelating agent to be blended is preferably 0.62 to 7 parts, more preferably 0.8 to 5 parts, based on 100 parts of the vinyl chloride resin. This is because if the content is less than 0.2 parts, the effect as a stabilizing aid cannot be obtained, and if it exceeds 7 parts, the heat resistance tends to decrease.

A plasticizer is usually added for the purpose of adjusting the flexibility of the coating film. Examples of plasticizers include di-2-ethylhexyl phthalate, diheptyl phthalate, di-normal octyl phthalate, and diisodecyl phthalate.

Esters such as tricresyl phosphate, dioctyl adipate, di-2-ethylhexyl sebacate, and texanol isobutitrate, resins such as polyester and epoxy, fats and oils such as epoxidized soybean oil, and usually vinyl chloride resins. Among those that can be used as plasticizers,
Depending on the usage conditions such as the type of paint to be prepared, one or more plasticizers can be selected and used as appropriate.

In the coating composition of the present invention, the amount of plasticizer added is not particularly limited, but depending on the type of paint to be created, it is preferable to add the plasticizer within the range of the amount commonly used for this paint. For example, in vinyl sol paints for metal plates, the amount of plasticizer added is 30-30 parts per 100 parts of vinyl chloride resin.
Preferably, it is within the range of 100 parts. If the amount of plasticizer added is less than 30 parts, the coating film will lack flexibility and become hard and brittle, making it difficult for the coating film to follow the bending process of the metal plate. This is because if it exceeds the range, the coating film tends to become too soft and cannot function as a protective film.

In this invention, depending on the type of paint to be prepared, a viscosity modifier, pigment, pigment dispersant, solvent, binder resin, etc. are further added, if necessary, to form a paint composition.

The coating composition of the present invention can be used by a commonly used coating film forming method. For example, the following substrates are used to apply the vinyl sol paint for metal plates. That is, the surface of metal plates such as various steel plates is subjected to pre-treatments such as degreasing, phosphate treatment, chromium treatment, etc. as necessary, and furthermore, long-term adhesion is achieved.

In order to provide corrosion resistance, water resistance, etc., an undercoat paint consisting of a blend of various resins, etc., and containing pigments such as anti-corrosion pigments as necessary, is applied using a roll coater or other coating means. If necessary, a film formed through a process such as baking and drying is used. Examples of metal plates used in this example include cold-rolled steel plates, hot-dip galvanized steel plates, electrogalvanized steel plates, hot-dip aluminized steel plates, aluminum galvanized steel plates, stainless steel plates, tin-plated steel plates, and chromium-treated steel plates. As an undercoat paint, acrylic resin-epoxy resin, acrylic resin-phenolic resin-
Blends of resins such as epoxy resin, acrylic resin-phenolic resin-epoxy resin-vinyl resin, and polyester resin-phenolic resin-epoxy resin-vinyl resin are mainly used. A method for applying the coating composition of the present invention onto the substrate is a roll coater.

A conventional coating method using a curtain flow coater, knife coater, etc. can be employed.

The applied coating film is baked at a substrate temperature of 190 to 240°C, embossed if necessary, and cooled to become a product. In this example, which is used as a vinyl sol coating for metal plates, the coating film exhibits the best physical properties within the film thickness range of 30 to 500 microns.

However, it goes without saying that if the type or use of the coating composition differs, a range of film thickness exhibiting the best physical properties will be determined depending on each coating composition.

Ba-Zn system and Mg-Z used in this invention
N-based composite metal soaps have traditionally been used as stabilizers for vinyl chloride resins, but the inventor's research has shown that even when Ba-Zn-based soaps are used alone,
Even if a Ba-Zn system and a Mg-Zn system are mixed and used, the effect as a stabilizer is low in the conventional combination. In other words, simply drying and baking the paint film could cause the vinyl chloride resin to thermally decompose and change color, so it could not be put to practical use unless it was used in combination with other highly effective stabilizers. . However, in this invention, Ba-Zn and Mg-based stabilizers, which were conventionally considered to be less effective as stabilizers, were used.
When using Zn-based composite metal soap, add a larger amount than usual (6 to 21 parts per 100 parts of vinyl chloride resin), and also use a chelating agent as a stabilizing agent. By doing so, these Ba-Z
This made it possible for n-based and Mg-Zn-based composite metal soaps to exhibit high effectiveness as stabilizers.

The coating composition of the present invention uses only non-toxic and odorless Ba-Zn-based and Mg-Zn-based composite metal soap stabilizers and chelating agents, so it is suitable for coating when used for interior materials, etc. Moreover, as mentioned above, high heat resistance and light resistance can be obtained.

(Examples 1-1 to 1-21) Vinyl chloride resin powder (Zeon 121 manufactured by Nippon Zeon Co., Ltd.) 1
00 parts, Mg-Zn composite metal soap (AC-1500 manufactured by Adeka Argus Chemical Co., Ltd.) and Ba-Zn composite metal soap (Ad-B manufactured by Katsuta Kako Co., Ltd.) were used as stabilizers.
Z181BJ) was blended in the component ratios shown in Table 1, and a chelating agent, plasticizer, viscosity modifier, and pigment were blended in the component ratios shown below to create a vinyl sol paint for metal plates. Here, 1-1.1-2 in Table 1. ... indicates the number of the example, and how to read this table is, for example, in Example 1-5, the total amount of stabilizer was 9 parts with respect to 100 parts of vinyl chloride resin, and Ba-Zn system and Mg-Zn system were used. It is said that the blending ratio of the system is 70/30.

Vinyl chloride resin powder...100 parts Stabilizer
... 6 to 21 parts chelating agent 4.4'-, isopropylidene diphenol alkyl phosphite (as the alkyl group, use C82 to CIS) ... 2 parts distearyl pentaerythritol diphosphite...・2 parts tricyclohexyl phenyl phosphite...1 part plasticizer (DOP)...65 parts viscosity modifier (
TX I B)...5 parts pigment
...15 parts, plate thickness 0.35 mm, zinc weight 305 g/M on both sides
The surface of a hot-dip galvanized steel sheet is treated with zinc phosphate, and an acrylic-phenol modified resin undercoat is applied and baked to a film thickness of 5 μm after baking. A vinyl sol paint for boards was applied onto this base material so that the film thickness after baking was 80 μm, and the total temperature of the base material was set at 215°C, 225°C, 235°C, and 245°C in a Tabai electric furnace. The coating was baked and the color change due to thermal decomposition of the coating film was observed every minute. Table 2 shows the observation results of discoloration due to thermal decomposition.

(Comparative Examples 1-1 to 1-3) Coating films were created in the same manner as Examples 1-1 to 1-21, except that the total amount of stabilizer was 3 parts per 100 parts of vinyl chloride resin powder. , made observations.

However, the mixing ratio of Ba-Zn and MgZn is 10010
Comparative Example 1-3 was obtained by changing the ratio of 1 to 1.70/30 to 2.50150 to Comparative Example 1-3. The results are also shown in Table 2.

(Conventional Example 1) As a stabilizer, a butyltin mercaptide-based stabilizer (T'-17MJ manufactured by Katsuta Kako Co., Ltd.) was added to 100% of vinyl chloride resin powder.
Examples 1-1 to 1-2 except that 6 parts to 1 part were blended.
A coating film was created and observed in the same manner as in Example 1. The results are also shown in Table 2.

Regarding the above Examples, Comparative Examples, and Conventional Examples, when observing the discoloration due to thermal decomposition, the odor was also investigated. In the conventional examples, a bad odor was felt in all cases, but in the examples and comparative examples of the present invention, there was no disturbing odor.

(Examples 2-1 to 2-21) Coating films were formed in the same manner as in Example 1, except that the film thickness of the vinyl sol paint for metal plates was 200 μm.

The total amount of stabilizer added and the component ratio of Ba-Zn composite metal soap and Mg-Zn composite metal soap were
Table 4 shows the results of observing the discoloration of the coating film due to thermal decomposition. Here, Table 3 is prepared in the same way as Table 1.
The relationship between the example magnet and the amount and ratio of stabilizer blended is shown below.

(Comparative Examples 2-1 to 2-3) Coating films were created and observed in the same manner as in Comparative Examples 1-1 to 1-3, except that the film thickness was 200 μm. 4th result
Shown in the table.

(Conventional Example 2) A coating film was prepared in the same manner as in Conventional Example 1 except that the film thickness was 200 μm, and the six results of observation are also shown in Table 4.

The above Examples, Comparative Examples, and Conventional Examples were also examined for odor when observing discoloration due to thermal decomposition, but no foul odor was detected except for the Conventional Examples.

〔Effect of the invention〕

Claims (2)

[Claims] (1) A coating composition mainly composed of a vinyl chloride resin, and a stabilizer consisting of at least a Ba-Zn-based composite metal soap among Ba-Zn-based and Mg-Zn-based;
It contains a chelating agent that helps the function of the stabilizer, and the amount of the stabilizer added is 6 parts by weight per 100 parts by weight of the vinyl chloride resin.
21 parts by weight of a coating composition. (2) The coating composition according to claim 1, which is a vinyl sol coating for metal plates.