JP2000160068A - Anti-foaming agent for clear coating material and smoothing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface-adjusting agent which imparts an anti-foaming property and smoothness without detriment to transparency of a coating film by composing it of a copolymer of a specific amount of a vinylic reactive monomer bearing a benzotriazole group or a vinylic reactive monomer bearing a benzophenone group with a specific amount of another monomer or polymer bearing a polymerizable double bond. SOLUTION: This agent is constituted of a copolymer comprising 5-50 wt.% of a vinylic reactive monomer bearing a benzotriazole group represented by formula I or a vinylic reactive monomer bearing a benzophenone group represented by formula II with 95-50 wt.% of another monomer, bearing a polymerizable double bond (e.g. octadecyl methacrylate) or polymer (e.g. a butadiene polymer). In the formulae, R1 is vinyl; and R2 and R3 are each H, an alkyl, vinyl, an alkenyl or an alkoxy. The surface-adjusting agent can be effectively used for a clear top coating material for automobiles or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifoaming agent for a clear paint or a smoothing agent for a clear paint, which imparts defoaming properties and smoothness to a clear paint in which transparency is emphasized without impairing its clearness. It relates to the agent.

[0002]

2. Description of the Related Art In general, a paint includes a defoaming agent for eliminating bubbles entrained during painting, a leveling agent (leveling agent) for improving wettability to an object to be painted at the time of painting, and for smooth painting. ) Is compounded. However, when these antifoaming agents and leveling agents (hereinafter collectively referred to as surface conditioners) are blended into the clear paint, the surface conditioners are present as particles in the cured clear paint and may cause turbidity in the coating film. Was.

[0003]

In general, when a paint is applied, the appearance of the paint film is deteriorated without the bubbles entrained at the time of painting disappearing, and the protection performance of the object to be coated is deteriorated by pinholes caused by the bubbles. An antifoaming agent is blended in order to prevent the phenomenon of not being sufficiently obtained. In addition, a smoothing agent is blended to prevent uneven coating that occurs at the time of painting, to prevent repelling of the coating film that occurs when foreign matter is attached to the object to be coated, and to make the painted surface smooth and beautiful. You.

[0004] However, a solvent-type clear top coat for metallic colors of automobiles, a powder type clear top coat, or a UV-curable clear coat for woodwork, etc., which have recently been widely used, have been used. When the surface conditioner is blended, the compounded surface conditioner is present as fine particles in the cured coating film after coating, which may cause turbidity and impair the appearance of the finished coating film.
In addition, when the amount is limited so as not to impair the clearness, the performance of the surface conditioner itself often cannot be sufficiently exhibited.

Accordingly, an object of the present invention is to provide a surface conditioner which does not cause turbidity even when blended in a clear coating which emphasizes transparency.

[0006]

Means for Solving the Problems The present inventors have made various studies and found that a polymer obtained by polymerizing a vinyl monomer, which has been used as a conventional surface conditioner for coating materials, is obtained. And a vinyl monomer having a benzotriazole group represented by the general formula 1
By copolymerizing a vinyl-based monomer having a benzophenone group represented by (Chemical Formula 2) with a conventional polymer, it is possible to prevent almost no turbidity when blended into a clear paint without impairing the effect of the original surface conditioner. discovered. Thus, according to the present invention, the general formula

[0007]

Embedded image [Wherein, R ₁ represents a vinyl group. A vinyl-based reactive monomer having a benzotriazole group represented by the general formula:

[0008]

Embedded image [Wherein, R ₂ represents H, an alkyl group, a vinyl group, an alkenyl group, or an alkoxy group, and R ₃ represents H, an alkyl group, a vinyl group, an alkenyl group, or an alkoxy group. 5 to 50% by weight of a vinyl-based reactive monomer having a benzophenone group represented by the formula (1) and 95 to 50% by weight of another monomer or polymer having a polymerizable double bond which reacts with the vinyl-based reactive monomer. An antifoaming agent or leveling agent for paints or inks, which is obtained by copolymerization, is provided.

In the copolymer of the present invention, if the weight percent of the vinyl monomer having a benzotriazole group or the vinyl monomer having a benzophenone group is less than 5%, the transparency when blended in a clear coating composition is not improved. Not enough. On the other hand, when the content is more than 50% by weight, the effect as a surface conditioner cannot be sufficiently exerted, and on the contrary, the transparency is adversely affected.

Examples of the vinyl monomer having a benzotriazole group include 3- (2H-1,2,3-benzotriazol-2-yl) -4-hydroxyphenethyl-methacrylate having a benzotriazole skeleton. Can be

Examples of the vinyl monomer having a benzophenone group include 2-hydroxy-4-methacryloyloxyethoxy-benzophenone in which a methacryloyloxyethoxy group is introduced into the skeleton of benzophenone.

Examples of the compound used as a surface conditioner, which are reactive with a vinyl monomer having a benzotriazole group or a vinyl monomer having a benzophenone group, include ethyl acrylate, butyl acrylate, and the like. Alkyl acrylates such as 2-ethylhexyl acrylate and lauryl acrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, hexadecyl methacrylate, methacrylic acid Alkyl methacrylates such as octadecyl ester,
Alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, lauryl vinyl ether, octadecyl vinyl ether, etc., and reactive silicones having a methacryloyloxy group (Silaprene FM-0711 and TOA commercially available from Chisso Corporation) AK-5 and AK-30 commercially available from Gosei Co., Ltd.
) And polymers having reactive groups such as so-called macromonomers such as reactive acrylic polymers (Diamac series commercially available from Mitsubishi Chemical Corporation and A-series commercially available from Toagosei Co., Ltd.) and butadiene polymers Although there are many other types of materials used as a raw material for the surface conditioner, those which can be copolymerized with the reactive monomers shown in (Chemical Formula 1) and (Chemical Formula 2) Then everything is available.

As a method for synthesizing a copolymer of a compound having a vinyl group used in the present invention, a radical polymerization method using a peroxide or an azo compound, a cationic polymerization method using an acid catalyst, an alkali metal An anionic polymerization method using a catalyst is used. The present invention is an invention relating to the development of uses of the copolymer, and is not limited at all by the synthesis method.

The coatings suitable for the present invention are clear coatings which place importance on the transparency of the finish, and can be effectively used for clear top coat coatings for automobiles and ultraviolet curing coatings for woodwork. .

The timing of adding the paint surface modifier of the present invention to the paint may be during the process of producing the paint or after the paint has been produced.

The addition amount of the surface conditioner for paints of the present invention is sufficiently effective when it is the same as that of the usual surface conditioner for paints. Furthermore, since turbidity hardly occurs in the coating film, it is possible to mix more than a usual surface conditioner for coating materials.

[0017]

The surface conditioner for paints of the present invention, when incorporated in a clear paint, can provide defoaming properties and smoothness without impairing the transparency of the paint film.

[0018]

Next, the present invention will be described in more detail with reference to examples. In the following, "part" and "%"
"Parts by weight" and "% by weight" are indicated. Example 1 Production of Antifoaming Example 1 100 parts of xylene was charged into a 1000 ml reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen gas inlet, and 90 parts of nitrogen were introduced while introducing nitrogen gas.
After the temperature was raised to ° C., a dropping solution (a-1) shown below was dropped at a constant speed for 90 minutes using a dropping funnel. Dropping solution (a-1) octadecyl methacrylate 255 parts RUVA-93 * 1) 45 parts xylene 100 parts t-butylperoxy-2-ethylhexanoate 4.5 parts * 1) 3- (2H-1, 2,3-benzotriazol-2-yl) -4-hydroxyphenethyl-methacrylate (manufactured by Otsuka Chemical Co., Ltd.) One hour after the completion of the dropwise addition of the dropping solution (a-1), t-butylperoxy-2- Add 1.5 parts of ethyl hexanoate,
Further, the reaction was carried out for 3 hours while maintaining the temperature of 90 ° C. After completion of the reaction, the solid content was adjusted to 30% with xylene to obtain an antifoaming agent [DG-1]. The weight average molecular weight of the synthesized polymer was 125,000. Preparation Example 2 of Antifoaming Agent The following dropping solution (a-2) was used in place of the dropping solution (a-1) of Example 1 and the reaction temperature was 10
A defoaming agent was produced in the same manner as in Example 1 except that the temperature was changed to 0 ° C. Dropping solution (a-2) Hexadecyl methacrylate 190 parts Lauryl vinyl ether 80 parts RUVA-93 30 parts Xylene 100 parts t-butylperoxy-2-ethylhexanoate 3 parts After the reaction is completed, the solid content is 30% with xylene To obtain an antifoaming agent [DG-2]. The weight average molecular weight of the synthesized polymer was 85,000. Production Example 3 of Defoaming Agent In a reaction vessel similar to that of Production Example 1 of defoaming agent, 20 parts of polybutadiene B-3000 * 2) and 185 parts of xylene were charged, and heated to 100 ° C. while introducing nitrogen gas. After warming, the dropping solution (a-3) shown below was
The solution was dropped at a constant speed over time.

* 2) 1,2-polybutadiene (manufactured by Nippon Soda Co., Ltd.)Dropping solution (a-3) Lauryl methacrylate 140 parts RUVA-93 40 parts Xylene 185 parts t-butylperoxy-2-ethylhexanoate 15 parts One hour after completion of the dropwise addition of the dropping solution (a-3), t-butyl is added.
3 parts of peroxy-2-ethylhexanoate are added.
The reaction was continued for 2 hours while maintaining the temperature at 100 ° C. End of reaction
After completion, the solid content was adjusted to 30% with xylene, and an antifoaming agent [DG
-3] was obtained. The weight average molecular weight of the synthesized polymer is 3
0000.Production Example 1 of Leveling Agent Stirrer, reflux condenser, dropping funnel, thermometer and nitrogen gas
Into a 1000 ml reaction vessel equipped with a
110 ° C while charging 150 parts of ene and introducing nitrogen gas
Temperature and reflux the toluene, then the drop solution shown below
(B-1) was dropped at a constant speed over 2 hours using a dropping funnel.Dropping solution (b-1) Acrylic acid 2-ethylhexyl ester 240 parts RUVA-93 60 parts Toluene 100 parts t-butylperoxy-2-ethylhexanoate 6 parts One hour after completion of the dropwise addition of the dropping solution (b-1), t-butyl is added.
Add 3 parts of peroxy-2-hexanoate and add 1 part
The reaction was carried out for 2 hours while maintaining 10 ° C. After the reaction
The solid content is adjusted to 50% with Ruen, and a leveling agent [SG-1]
I got The number average molecular weight of the synthesized polymer is 10,000
Met.Production Example 2 of Leveling Agent Production of leveling agent Instead of the dropping solution (b-1) of Example 1,
Except for using the following dropping solution (b-2),
The reaction was carried out in the same manner as in Example 1.Dropping solution (b-2) Acrylic acid n-butyl ester 175 parts Isobutyl vinyl ether 80 parts RUVA-93 45 parts Toluene 100 parts t-butyl peroxy-2-ethylhexanoate 15 parts After completion of the reaction, the solid content is adjusted to 50% with toluene and smoothed.
Agent [SG-2] was obtained. Number average molecular weight of synthesized polymer
Was 3500.Production Example 3 of leveling agent Production of leveling agent Instead of the dropping solution (b-1) of Example 1,
Except for using the following dropping solution (b-3),
The reaction was carried out in the same manner as in Example 1.Dropping solution (b-3) Acrylic acid n-butyl ester 180 parts Silaprene FM-0711 * 3) 60 parts RUVA-93 60 parts Toluene 100 parts t-butyl peroxy-2-ethylhexanoate 15 parts * 3) Methacryloyloxypropyl polydimethylsiloxane
After the completion of the loxane (Chisso Corporation) reaction,
The mixture was adjusted to 50% with ene to obtain a leveling agent [SG-3]. Combination
The number average molecular weight of the formed polymer was 6,000.Production Comparative Example 1 of Antifoaming Agent Preparation of antifoaming agent In a reaction vessel similar to that shown in Example 1,
Charge 100 parts of xylene and add 9 parts of nitrogen while introducing nitrogen gas.
After the temperature was raised to 0 ° C, a dropping solution (c-1) shown below was dropped.
The mixture was dropped at a constant speed for 90 minutes by a funnel.Dropping solution (c-1) Octadecyl methacrylate 300 parts Xylene 100 parts t-butylperoxy-2-ethylhexanoate 4.5 parts One hour after completion of the dropwise addition of the dropping solution (c-1),
1.5 parts of -oxy-2-ethylhexanoate were added,
Further, the reaction was carried out for 3 hours while maintaining the temperature of 90 ° C. Anti
After the reaction, adjust the solid content to 30% with xylene,
[DN-1] was obtained. Weight average molecular weight of synthesized polymer
Was 120,000.Production Comparative Example 2 of Antifoaming Agent Preparation of antifoaming agent In place of dropping solution (c-1) of Comparative Example 1,
The above dropping solution (c-2) was used and the reaction temperature was 10
Except that the temperature was set to 0 ° C., the same method as in Comparative Example 1 for the defoaming agent was used.
Built.Dropping solution (c-2) Hexadecyl methacrylate 210 parts Lauryl vinyl ether 90 parts Xylene 100 parts T-butyl peroxy-2-ethylhexanoate 3 parts After completion of the reaction, the solid content is adjusted to 30% with xylene, and an antifoaming agent is used.
[DN-2] was obtained. Weight average molecular weight of synthesized polymer
Was 90000.Production Comparative Example 3 of Antifoaming Agent Preparation of defoamer Polybutadiamine was placed in the same reaction vessel as in Example 1.
25 parts of B-3000 and 185 parts of xylene
After heating to 100 ° C while introducing nitrogen gas,
In 4 hours with a dropping funnel
The solution was dropped at a constant speed. Dropping solution (c-3) Lauryl methacrylate 175 parts Xylene 185 parts t-butyl peroxy-2-ethylhexanoate 15 parts One hour after the completion of the dropwise addition of the dropping solution (c-3), t-butyl was added.
3 parts of peroxy-2-ethylhexanoate are added.
The reaction was continued for 2 hours while maintaining the temperature at 100 ° C. End of reaction
After completion, the solid content was adjusted to 30% with xylene, and an antifoaming agent [DN
-3] was obtained. The weight average molecular weight of the synthesized polymer is 3
5000.Production Comparative Example 1 for Leveling Agent Preparation of leveling agent In a reaction vessel similar to that shown in Example 1,
While charging 150 parts of toluene and introducing nitrogen gas, 11
After raising the temperature to 0 ° C and refluxing toluene, the following drop was added.
The solution (d-1) was dropped at a constant speed over 2 hours using a dropping funnel.
Was.Dropping solution (d-1) Acrylic acid 2-ethylhexyl ester 300 parts Toluene 100 parts t-butylperoxy-2-ethylhexanoate 6 parts One hour after completion of the dropwise addition of the dropping solution (d-1), t-butyl is added.
Add 3 parts of peroxy-2-hexanoate and add 1 part
The reaction was carried out for 2 hours while maintaining 10 ° C. After the reaction
The solid content is adjusted to 50% with Ruen, and a leveling agent [SN-1]
I got The number average molecular weight of the synthesized polymer is 9500.
there were.Production Comparative Example 2 for Leveling Agent Production of Leveling Agent Instead of the dropping solution (d-1) of Comparative Example 1,
Except for using the following dropping solution (d-2),
The reaction was carried out in the same manner as in Comparative Example 1.Dropping solution (d-2) Acrylic acid n-butyl ester 205 parts Isobutyl vinyl ether 95 parts Toluene 100 parts t-butyl peroxy-2-ethylhexanoate 15 parts After completion of the reaction, the solid content was adjusted to 50% with toluene and smoothed.
Agent [SN-2] was obtained. Number average molecular weight of synthesized polymer
Was 3000.Comparative Example 3 for Production of Leveling Agent Production of Leveling Agent Instead of the dropping solution (d-1) of Example 1,
Except for using the following dropping solution (d-3),
The reaction was carried out in the same manner as in Comparative Example 1.Dropping solution (d-3) Acrylic acid n-butyl ester 225 parts Silaprene FM-0711 75 parts Toluene 100 parts t-butyl peroxy-2-ethylhexanoate 15 parts After the reaction is completed, the solid content is adjusted to 50% with toluene and smoothed.
Agent [SN-3] was obtained. Number average molecular weight of synthesized polymer
Was 5500.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4] Example 1 (Transparency test of antifoaming agent in acrylic melamine baking type clear paint) A baking type acrylic melamine resin clear coating composition having the composition shown in Table 5 was tested for transparency of a coating film. Further, the composition was applied on the base coat paint shown in Table 6 to conduct a test for defoaming.

The raw materials except for the diluting solvent shown in Table 5 were uniformly mixed with a disper stirrer to prepare an acrylic melamine clear paint. 1% by weight of the defoaming agents shown in Tables 1 and 3 was added to this coating composition based on the clear coating composition, and the mixture was dispersed at 2000 rpm for 2 minutes using a disperser. The paint was applied to a glass plate using a 150 μm applicator and baked in an oven at 140 ° C. for 20 minutes for curing for transparency testing.

The test of the defoaming property was performed as follows. First, the viscosity of the base coat paint shown in Table 6 was adjusted using a diluting solvent so that the viscosity was 13 seconds with Ford Cup # 4. Apply this base coat paint to the tin plate by air spraying.
Using a gun, coating was performed so that the dried coating film became 15 μm. This base coat is dry to the touch (dry state)
In this state, the clear paint for test was adjusted to 22 seconds with a Ford cup # 4 using a diluting solvent using a diluting solvent, and was dried with an air spray gun so that the film thickness of the dried coating film became 20 μm to 100 μm. , With varying thickness (hereinafter referred to as slant coating). Let stand for 3 minutes after painting.
It was baked in a 60 ° C. oven for 20 minutes to cure.

The evaluation of the coating film test was performed as follows.
The transparency of the coating film was evaluated on a five-point scale from “best” (5) to “worst” (1) by visually observing what was applied to the glass plate. In the defoaming test, the film thickness of bubbles (hereinafter referred to as "arms") generated on the painted surface of the tin plate was measured using a film thickness meter, and the overall number of arms was visually observed. The evaluation was made on a five-point scale from “best” (5) with the smallest number to “worst” (1) with the largest number. Table 7 shows the results of the above tests.

[0027]

[Table 5]

[0028]

[Table 6]

[0029]

[Table 7] Example 2 (Transparency Test of Smoothing Agent in Ultraviolet-Curable Clear Coating) With respect to the ultraviolet-curable resin clear coating composition having the composition shown in Table 8, the transparency of a coating film to which a smoothing agent was added was tested. Was.

The raw materials except for the diluting solvent (Unidic Thinner # 016) shown in Table 8 were uniformly mixed with a disper stirrer to prepare an ultraviolet-curable clear coating. To the paint was added 0.5% by weight of the clearing paints in Tables 2 and 4 with respect to the clear paint, and the dispersion was stirred for 2000 hours using a disperser stirrer.
Dispersed for 2 minutes at rpm. This paint was applied to a glass plate using a 200 μm applicator for a transparency test, preliminarily dried at 60 ° C. for 5 minutes, and then using a conveyor-type ultraviolet device (UVC-2533, manufactured by Ushio Inc.). Cured.

The test for smoothness was performed as follows. Wood material (oak) is coated with a primer, sanded, and the viscosity is adjusted by adding a diluting solvent to the clear paint for testing. The dried paint film thickness is 10 μm with an air spray gun. It was painted to become. 60 ℃ after painting
For 5 minutes, and then cured using a conveyor-type ultraviolet device.

The evaluation of the coating film test was performed as follows.
The transparency of the coating film was evaluated on a five-point scale from “best” (5) to “worst” (1) by visually observing what was applied to the glass plate. In addition, in the test of smoothness, a standard plate of five grades from “best” (5) to “worst” (1) was prepared and visually evaluated. Table 9 shows the results of the above tests.

[0033]

[Table 8]

[0034]

[Table 9] Example 3 (Test of Transparency of Leveling Agent in Clear Powder Coating) The acrylic clear powder coating composition having the composition shown in Table 10 was tested for the transparency of a coating film to which a leveling agent was added. Was.

(Preparation of Masterbatch) The acrylic resin (A-253) to be used is melted at 170 ° C., and the leveling agents shown in Tables 2 and 4 are dispersed therein so as to have a solid content of 10%. While stirring at high speed. After cooling, the mixture was pulverized with a pin mill and passed through a 32-mesh sieve to obtain a 10% acrylic resin master batch composition.

(Preparation of Acrylic Powder Coating) Acrylic powder coating containing the master batch composition prepared by the above method and having the composition shown in Table 10 was dry-mixed, and then heated to 100 ° C. to 110 ° C.
The mixture was melted and kneaded with an extruder kept at a temperature of ℃. After cooling, the mixture was pulverized with a pin mill and passed through a 150-mesh sieve to obtain a clear powder coating composition in the form of a white powder.

(Coating and Evaluation of Acrylic Powder Coating)
In order to evaluate the transparency of the obtained powder, the cured film thickness was 1
The powder was sprayed on a glass plate so as to have a thickness of 00 μm by an electrostatic powder coating method. For evaluation of smoothness, a heat-resistant stainless steel plate (0.5 × 70 × 100 mm) was sprayed so that the cured film thickness became 40 μm. Next, the coated plate was baked at 160 ° C. for 30 minutes to evaluate the transparency and the smoothness. Table 11 shows the results.

[0038]

[Table 10]

[0039]

[Table 11]

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[Procedure amendment]

[Submission date] January 6, 1999 (1999.1.6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

The test for smoothness was performed as follows. Painted wood material (oak wood) with primer, sanded painted board, adjusted viscosity by adding diluent solvent to clear paint for test, dried with air spray gun, paint film
The film thickness of the coating so as to 10μm. 60 ℃ after painting
For 5 minutes, and then cured using a conveyor-type ultraviolet device.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

[0038]

[Table 10]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

[0039]

[Table 11]

Continuing from the front page (72) Inventor Takashi Horiguchi 1525 Cowbell 105, Hikawa-cho, Soka City, Saitama Prefecture (72) Inventor Yasuhiro Oiwa 1-23-3 Hanaguri, Soka City, Saitama Prefecture Heights Hanaguri 206 (72) Inventor Shigeru Kawato Saitama 445-7 Kinmeicho, Soka City, F-term F-reference (reference) 4J038 CC092 EA011 GA08 4J039 AD10 AD15 AD17 AD20 AD23 AE11 BE16 BE33 EA33

Claims (1)

[Claims] 1. A compound of the general formula [Wherein, R ₁ represents a vinyl group. Or a vinyl-type reactive monomer having a benzotriazole group represented by the general formula: [Wherein, R ₂ represents H, an alkyl group, a vinyl group, an alkenyl group, or an alkoxy group, and R ₃ represents H, an alkyl group, a vinyl group, an alkenyl group, or an alkoxy group. And a copolymer of 5 to 50% by weight of a vinyl-based reactive monomer having a benzophenone group and 95 to 50% by weight of another monomer or polymer having a polymerizable double bond. Antifoam or leveling agent for paints or inks.