JP6993676B2 - Defoamer - Google Patents

Description

The present invention relates to an antifoaming agent. More specifically, the present invention relates to a defoaming agent suitable for a non-aqueous coating composition.

［式中、Ｒｆはフルオロアルキル基、Ｒ１は炭素数１～６のアルキル基またはフェニル基であり、これらは同一でも異なっていてもよく、Ｒ２は炭素数１～６の炭化水素基、ＯＨ基またはアルコキシ基である。ｍは１～２００００の整数を、ｎは１～１０００の整数を示す。］で表される化合物と下記一般式（２）

［式中、Ｒ３は炭素数１～４のアルキル基であり、Ｒ４は炭素数１２～２４の炭化水素基である。］で表されるアクリル酸アルキルエステル単量体の単独あるいはその２種以上を重合（共重合）して得られる平均分子量１００００～２０００００の重合体とからなる非水系樹脂分散型塗料用消泡剤が知られている（特許文献１）。 As a defoaming agent for non-aqueous coating compositions, the following general formula (1)

[In the formula, Rf is a fluoroalkyl group, R1 is an alkyl group or a phenyl group having 1 to 6 carbon atoms, and these may be the same or different, and R2 is a hydrocarbon group having 1 to 6 carbon atoms and an OH group. Or it is an alkoxy group. m represents an integer of 1 to 20000, and n represents an integer of 1 to 1000. ] And the following general formula (2)

[In the formula, R3 is an alkyl group having 1 to 4 carbon atoms, and R4 is a hydrocarbon group having 12 to 24 carbon atoms. ], A defoaming agent for non-aqueous resin-dispersed paints, which is a polymer having an average molecular weight of 10,000 to 200,000 obtained by polymerizing (copolymerizing) the acrylic acid alkyl ester monomer alone or two or more thereof. Is known (Patent Document 1).

JP-A-2002-301306

The conventional defoaming agent has a problem that craters and the like are generated and the finished appearance and stainability of the coating film are inferior.
An object of the present invention is to provide a defoaming agent having excellent finished appearance and stain resistance of a coating film.

The features of the defoaming agent of the present invention are silicone (A1) having a weight average molecular weight of 200,000 to 2 million, silicone (A2) having a weight average molecular weight of 30,000 to 150,000, and a liquid polymer (B). Contains ,
The gist is that the liquid polymer (B) is a poly-α-olefin (b1), a polydiene (b2), or a mixture thereof .

The gist of the non-aqueous coating composition of the present invention is that it contains the above-mentioned defoaming agent, filler, and binder.

The defoaming agent of the present invention is excellent in the finished appearance and stain resistance of the coating film.

Since the non-aqueous coating composition of the present invention contains the above-mentioned defoaming agent, it is excellent in the finished appearance and stain resistance of the coating film.

Examples of the silicone (A1) having a weight average molecular weight (Mw) of 200,000 to 2,000,000 (preferably 300,000 to 800,000, more preferably 350,000 to 730,000) include polydimethylsiloxane (a11), α, ω-. Dihydroxy-polydimethylsiloxane (a12) and α-aminopropylpolydimethylsiloxane (a13) are included.

The weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) using polystyrene having a known molecular weight as a standard substance.

Silicone (A1) is readily available on the market, and polydimethylsiloxane (a11) includes KF-9008, KF-9011, KF-9013, KF-9014, KF-9028, KF-9030, MK-15H, X. -21-5495, KF-9028, KF-9030, X-21-5613, X-21-5666, X-21-5847 and X-21-5894 (above, Shin-Etsu Chemical Co., Ltd.); SH200-1, 000000cs, BY16-140, BY11-003, BY11-007, BY11-014, BY11-026, BY11-040, BY22-019, BY22-020, BY22-034, BY22-055, BY22-060 and BY25- 320 (above, Toray Dow Corning Co., Ltd.) and the like can be mentioned.

As α, ω-dihydroxy-polydimethylsiloxane (a12), X-21-5613, X-21-5666 (above, Shin-Etsu Chemical Co., Ltd.); 1501 Fluid, 1503 Fluid and CB-1556 Fluid (above, Toray Dow Corning). Co., Ltd.) and the like.

Examples of the α-aminopropylpolydimethylsiloxane (a13) include KF-8017, KF-8018 and KF-8020 (Shin-Etsu Chemical Co., Ltd.).

Among the silicones (A1), polydimethylsiloxane (a11), α, ω-dihydroxy-dimethylsiloxane (a12) and a mixture thereof are preferable, and polydimethylsiloxane (a11) is more preferable.

The silicone (A2) having a weight average molecular weight (Mw) of 30,000 to 150,000 (preferably 32,000 to 140,000, more preferably 34,000 to 130,000) contains polydimethylsiloxane. Easily available from the market, KF-96-100,000cs-2,000cs (above, Shin-Etsu Chemical Co., Ltd.); SH200-100,000cs-2,000cs (above, Toray Dow Corning Co., Ltd.), etc. Be done.

The liquid of the liquid polymer (B) means that the viscosity {the viscosity of itself (neat viscosity)} measured by a Brookfield type rotary viscometer based on JIS K7117-1: 1999 is 1,000 Pa · s (25 ° C.). It means that it is as follows.

The viscosity of the liquid polymer (B) (JIS K7117-1: 1999, 25 ° C., Pa · s, neat viscosity) is preferably 0.3 to 100, more preferably 0.6 to 95, and particularly preferably 0. It is 0.7 to 90.

The liquid polymer (B) is not particularly limited as long as it is liquid, and examples thereof include polyα-olefins (b1), polydiene (b2), and mixtures thereof.

The poly-α-olefin (b1) is not particularly limited as long as it is composed of an α-olefin and is a liquid (co) polymer.

As the α-olefin, ethylene, propylene, 1-butene, 1-hexene, 1-octene and the like can be used. Of these, ethylene, propylene and 1-butene are preferable, and ethylene and propylene are more preferable.

Among the poly-α-olefins (b1), ethylene-α-olefin copolymers and polypropylenes are preferable, and ethylene-propylene copolymers are more preferable, from the viewpoint of the finished appearance of the coating film and stain resistance.

Poly-α-olefins are readily available on the market and are available in the Lucant® series {HC-40 (830 mPa · s), HC-100 (2.6 Pa · s), HC-600 (27 Pa · s), HC-1100. (50 Pa · s), HC-2000 (95 Pa · s)}, etc. (Mitsui Chemicals, Inc.) can be mentioned. The values in parentheses are the viscosities measured at 25 ° C. using a Brookfield type rotary viscometer conforming to JIS K7117-1: 1999.

The polydiene (b2) is not limited as long as it is a liquid polydiene, but polybutadiene and a butadiene copolymer are preferable, and polybutadiene is particularly preferable.

Examples of the copolymerized monomer of the butadiene copolymer include acrylonitrile and styrene.

Examples of the polydiene (b2) are easily available from the market, and examples thereof include POLYVEST (registered trademark) 110 (polybutadiene, 650 mPa · s), POLYVEST 130 (polybutadiene, 2.4 Pa · s) (Evonik Japan Co., Ltd.). The values in parentheses are the viscosities measured at 25 ° C. using a Brookfield type rotary viscometer conforming to JIS K7117-1: 1999.

As the liquid polymer (B), in addition to the poly α-olefin (b1), the polydiene (b2) and a mixture thereof, a poly (meth) acrylate (b3), a polyalkylene oxide compound (b4) and a mixture thereof are used. May be good.

The poly (meth) acrylate (b3) is not limited as long as it is a liquid poly (meth) acrylate, and polyacrylate, polymethacrylate, an acrylate / methacrylate copolymer and the like can be used. Examples of the (meth) acrylate include an ester of an alkyl having 1 to 30 carbon atoms and a (meth) acrylic acid. In addition, "... (meta) acri ..." means "... acri ..." and "... methacryl ...".

The polyalkylene oxide compound (b4) is not limited as long as it is a liquid polyalkylene oxide compound, and examples thereof include a reactant of an active hydrogen compound and an alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.).

Among these liquid polymers (B), poly-α-olefin (b1) and polydiene (b2) are preferable, and poly-α-olefin (b1) is more preferable.

The content (% by weight) of the silicone (A1) having a weight average molecular weight (Mw) of 200,000 to 2 million is silicone (A1), and the silicone (A2) having a weight average molecular weight (Mw) of 30,000 to 150,000. And based on the total weight of the liquid polymer (B), it is preferably 35 to 99, more preferably 50 to 98, and particularly preferably 60 to 94.

The content (% by weight) of the silicone (A2) is preferably 0.1 to 20 and more preferably 0.5 to 20 based on the total weight of the silicone (A1), the silicone (A2) and the liquid polymer (B). 10, particularly preferably 1 to 5.

The content (% by weight) of the liquid polymer (B) is preferably 0.9 to 50, more preferably 1.5, based on the total weight of the silicone (A1), the silicone (A2) and the liquid polymer (B). It is ~ 45, particularly preferably 5 ~ 39. Within these ranges, the finished appearance and stain resistance of the coating film are further improved.

The defoaming agent of the present invention can further contain polyorganosiloxane (C) having a weight average molecular weight smaller than that of silicone (A2).

As the polyorganosiloxane (C), any polyorganosiloxane excluding silicone (A1) and silicone (A2) can be used without limitation.

As the polyorganosiloxane (C), it is preferable that the silicone (A1) and the silicone (A2) can be uniformly dissolved, and the polydimethyl is 0.6 to 1,000 cSt (25 ° C., weight average molecular weight 162 to 22,000). Siloxane (KF-96 series: Shin-Etsu Chemical Industry Co., Ltd., SH200 series: Toray Dow Corning Co., Ltd., etc.), and cyclic dimethylsiloxane (hexamethylcyclotrisiloxane (molecular weight: 222), octamethylcyclotetrasiloxane (molecular weight: 296) ) And decamethylcyclopentasiloxane (molecular weight: 370), etc.) can be used. Of these, polydimethylsiloxane and cyclic dimethylsiloxane are preferred.

When the polyorganosiloxane (C) is contained, the content (% by weight) of the polyorganosiloxane (C) is 100 parts by weight in total of the silicone (A1), the silicone (A2) and the liquid polymer (B). It is preferably 50 to 1000, more preferably 100 to 500. Within this range, the defoaming performance is further improved.

The defoaming agent of the present invention may further contain a polyether-modified silicone (D).

Polyether modified silicone (D) is readily available on the market and is readily available on the market: SH3746, SH8428, SH3771, BY16-066, BY16-027, SH8400, SH3749, SH3748, SF8410, L-77, L-7001, L-7002, L. -7604, Y-7006, FZ-2101, FZ-2104, FZ-2105, FZ-2110, FZ-2118, FZ-2120, FZ-2123, FZ-2130, FZ-2161, FZ-2162, FZ-2163 , FZ-2164, FZ-2166 and FZ-2191 (above, Toray Dow Corning Co., Ltd.); KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-615A, KF-945. , KF-618, KF-6011 and KF-6015 (above, Shin-Etsu Chemical Industry Co., Ltd.); TSF4440, TSF4445, TSF4446, TSF4452, TSF4453 and TSF4460 (above, Momentive Performance Materials Japan LLC) Be done.

When the polyether-modified silicone (D) is contained, the content (% by weight) of the polyether-modified silicone (D) is 100 parts by weight in total of the silicone (A1), the silicone (A2) and the liquid polymer (B). It is preferably 0.01 to 10, and more preferably 0.1 to 1. Within this range, the finished appearance of the coating film is further improved.

The antifoaming agent of the present invention may further contain a solvent (E).

The solvent (E) is not particularly limited as long as it can uniformly dissolve silicone (A1), silicone (A2) and liquid polymer (B), and if necessary, polyorganosiloxane (C) and polyether-modified silicone (D), but carbon. Examples thereof include a ketone (E1) having 3 to 9 carbon atoms, a hydrocarbon (E2) having 5 to 12 carbon atoms, and an acetate ester (E3) having 3 to 6 carbon atoms.

Examples of the ketone (E1) having 3 to 9 carbon atoms include dimethyl ketone (acetone), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), cyclohexanone and the like.

Hydrocarbons (E2) having 5 to 12 carbon atoms include linear saturated hydrocarbons (n-pentane, n-hexane, n-heptane, n-dodecane, etc.) and branched saturated hydrocarbons (sec-pentane, tert-pentane, etc.). And isododecane, etc.), linear unsaturated hydrocarbons (1-pentene, 1-hexene, 1-dodecene, etc.) and branched unsaturated hydrocarbons (isopentene, 3-methyl-1-butene, 2,2-dimethyl-1-propene and Isododecene, etc.) and the like.

Examples of the acetic acid ester (E3) having 3 to 6 carbon atoms include methyl acetate, ethyl acetate, propyl acetate and butyl acetate.

When the solvent (E) is contained, the content (parts by weight) of the solvent (E) is 100 to 20000 with respect to a total of 100 parts by weight of the silicone (A1), the silicone (A2) and the liquid polymer (B). It is preferable, more preferably 400 to 2000. Within this range, the defoaming performance and the finished appearance of the coating film are further improved.

The defoaming agent of the present invention may further contain hydrophobic silica. When hydrophobic silica is contained, the defoaming performance is further improved.

The size and type of the hydrophobic silica are not limited as long as they can be finely dispersed in the defoaming agent of the present invention, but the specific surface area of the hydrophobic silica by the BET method is preferably at least 50 m ² / g.

The specific surface area by the BET method is based on JIS Z8830: 2013 "Method for measuring the specific surface area of powder (solid) by gas adsorption", and is a one-point method of gas adsorption method (carrier gas method) for hydrophobic silica in a dry state. Measure. A nitrogen-helium mixed gas is used as the carrier gas. Then, the specific surface area can be calculated from the value of the desorption peak.

Hydrophobic silica is readily available on the market, for example, as trade names, Nippil SS-10, SS-40, SS-50 and SS-100 (Tosoh Silica Co., Ltd., "Nippil" is Tosoh Silica Co., Ltd.) (Registered trademark of the company), AEROSIL R972, RX200 and RY200 (Japan Aerosil Co., Ltd., "AEROSIL" is a registered trademark of Evonik Degussa Game Beher), TS-530, TS-610, TS-720 (Cabot Carbon). AEROSIL R202, R805 and R812 (Degusa Japan Co., Ltd.), REOLOSIL MT-10, DM-10 and DM-20S (Tokuyama Co., Ltd., "REOLOSIL" is a registered trademark of the company), and SYLPHOBIC 100, 702. , 505 and 603 (Fuji Silicia Chemical Co., Ltd., "SYLPHOBIC" is a registered trademark of the company) and the like.

When hydrophobic silica is contained, the content (% by weight) of the hydrophobic silica is preferably 0.5 to 50 based on the total weight of the silicone (A1), the silicone (A2) and the liquid polymer (B). More preferably, it is 1 to 30. Within this range, the defoaming property is further improved.

The defoaming agent of the present invention comprises silicone (A1), silicone (A2) and liquid polymer (B) and, if necessary, polyorganosiloxane (C), polyether modified silicone (D), solvent (E) and / or hydrophobic. It can be prepared by uniformly mixing sex silica.
When the solvent (E) is contained, it is preferable to uniformly mix the solvent (E) at a temperature as low as possible (preferably 10 to 50 ° C, more preferably 20 to 40 ° C) in consideration of their volatility.

The defoaming agent of the present invention is effective for both water-based foaming liquids and non-water-based foaming liquids, but is more effective for non-water-based foaming liquids, and is particularly effective for non-water-based coating compositions. Among the non-water-based coating compositions, it is more effective for non-water-based paints used for painting industrial products and buildings, floor coating materials, rooftop waterproof paints, and the like. The water-based foaming liquid means a foaming liquid containing water, and the non-water-based foaming liquid (non-water-based coating composition or the like) means a foaming liquid containing no water (coating composition or the like).

The non-aqueous coating composition of the present invention contains the above-mentioned defoaming agent, filler and binder, but known components (filler and binder) other than the above-mentioned defoaming agent can be used.

As the filler, inorganic fine particles (mica, talc, kaolin, calcium carbonate, titanium oxide, barium sulfate, iron oxide, alumina, silica, carbon black, etc.) and organic fine particles (acrylic beads, silicon beads, polyethylene wax, etc.) can be used. ..

As the binder, polyester, polyurethane, polyamide, acrylic resin, phenol resin, alkyd resin, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride and a mixture thereof can be used.

The content (% by weight) of the defoaming agent in the non-aqueous coating composition is preferably 0.05 to 1, more preferably 0.1 to 0, based on the weights of the above-mentioned defoaming agent, filler and binder. It is .5.

The content (% by weight) of the filler is preferably 4 to 80, more preferably 9.5 to 70, based on the weights of the defoaming agent, the filler and the binder.

The content (% by weight) of the binder is preferably 19 to 95, more preferably 29.5 to 90, based on the weights of the defoaming agent, the filler and the binder.

The non-aqueous coating composition of the present invention may contain an additive that can be blended with a general non-aqueous coating composition within a range that does not affect the effect of the present invention. Such additives include hardeners, thickeners, plasticizers, preservatives, fungicides, fungicides, leveling agents, pigment dispersants, anti-skin agents, dryers, matting agents, UV absorbers. , Light stabilizers, antioxidants, hypocontamination agents, catalysts and the like.

The non-aqueous coating composition of the present invention can be produced by a conventionally known method. That is, it is obtained by uniformly mixing the above-mentioned defoaming agent, filler, binder and, if necessary, an additive.

Hereinafter, unless otherwise specified, parts mean parts by weight and% means parts by weight.
The weight average molecular weight was measured with the following equipment and conditions.
Measuring device; HLC-8220 manufactured by Tosoh Corporation
Column; Guard column HXL-H manufactured by Tosoh Corporation, TSKgel SuperHZ4000 manufactured by Tosoh Corporation, TSKgel SuperHZ3000 manufactured by Tosoh Corporation, TSKgel SuperHZ2000 manufactured by Tosoh Corporation, and TSKgel SuperHZ2000 manufactured by Tosoh Corporation. Differential refractometer)
Data processing; SC-8010 manufactured by Tosoh Corporation
Column temperature 40 ° C
Dissolution medium; Tetrahydrofuran Flow rate: 1.0 ml / min Standard substance; Polystyrene sample: 1% Tetrahydrofuran solution

(Example 1)
Silicone (a111, BY16-140, Toray Dow Corning Co., Ltd., Polydimethylsiloxane, weight average molecular weight 500,000) 60 parts, Silicone (a211, KF-96-100,000cs Shinetsu Chemical Industry Co., Ltd., Polydimethylsiloxane, weight) Average molecular weight 12,5000) 1 part, liquid polymer (B1, Lucant HC-2000, Mitsui Chemicals Co., Ltd., ethylene / propylene copolymer, 25 ° C. viscosity 95 Pa · s) 39 parts and solvent (E11, methylisobutylketone) 900 The portions were uniformly mixed to obtain the defoaming agent (1) of the present invention.

(Example 2)
470 parts of silicone (KF-9028, Shin-Etsu Chemical Industry Co., Ltd., decamethylcyclopentasiloxane (c1, molecular weight 370) diluted solution containing 20% of polydimethylsiloxane (a112) with a weight average molecular weight of 350,000) (polydimethylsiloxane (polydimethylsiloxane (a112)) a112) 94 parts and 376 parts of decamethylcyclopentasiloxane (c1) mixed solution), silicone (a212, KF-96-3 3,000cs Shinetsu Chemical Industry Co., Ltd., polydimethylsiloxane, weight average molecular weight 34,000) 1 part , Liquid polymer (B2, Lucant HC-40, Mitsui Chemicals Co., Ltd., ethylene / propylene copolymer, 25 ° C. viscosity 830 mPa · s) and 400 parts of solvent (E21, n-decane) were uniformly mixed. The defoaming agent (2) of the present invention was obtained.

(Example 3)
450 parts of silicone (decamethylcyclopentasiloxane (c1) diluted solution containing 20% of polydimethylsiloxane (a113) having a weight average molecular weight of 710,000, KF-9008, Shin-Etsu Chemical Industry Co., Ltd.) 90 parts (polydimethylsiloxane (a113) 90 (Mixed solution of 360 parts of decamethylcyclopentasiloxane (c1)), silicone (a213, KF-96-10,000cs, Shin-Etsu Chemical Industry Co., Ltd., polydimethylsiloxane, weight average molecular weight 54,000), 5 parts, liquid polymer (B3, POLYVEST110, Ebonic Japan Co., Ltd., Polybutadiene, 25 ° C viscosity 650 mPa · s) 5 parts, polyether modified silicone (D, FZ-2110, Toray Dow Corning Co., Ltd.) 0.5 parts and solvent (E31, acetic acid 2000 parts of butyl) was uniformly mixed to obtain the defoaming agent (3) of the present invention.

(Comparative Example 1)
100 parts of fluorosilicone (Shin-Etsu Chemical Co., Ltd., FA-630, fluorocarbon-modified dimethylsiloxane) and 2000 parts of solvent (E11) were uniformly mixed to obtain a defoaming agent (H1) for comparison.

As an evaluation sample, the defoaming agents (1) to (3) of the present invention and the defoaming agent (H1) for comparison are used and uniformly mixed with the following compounding composition to prepare a non-aqueous coating composition for evaluation (a non-aqueous coating composition for evaluation. 1)-(3) and (H1) were prepared {each number corresponds to the number of the defoaming agent obtained in Examples and Comparative Examples. }. In addition, a non-aqueous coating composition (blank) was prepared in the same manner except that the evaluation sample was not used.

Acrydic A-837 (* 1) 147 parts Typake R-930 (* 2) 228 parts Mineral Spirit 80 parts Efka RM1920 (* 3) 2 parts Acrydic A-848 (* 1) 508 parts Mineral Spirit 30 parts Evaluation sample (Antifoaming agent) 5 copies

* 1 Polyol resin, DIC Corporation, and "Acrydic" are registered trademarks of DIC Corporation.
* 2 Titanium dioxide, Ishihara Sangyo Co., Ltd., and "Typake" are registered trademarks of Ishihara Sangyo Co., Ltd.
* 3 Thickener, BASF Japan Ltd., "efka" is a registered trademark of BASF Society for Europe.

Performance test 1 (defoaming performance)
After diluting 1000 parts each of the non-aqueous coating compositions (1) to (3), (H1) and (blank) with mineral spirit and adjusting to 77 KU (25 ° C) with a Stormer viscometer, 25 ° C. Apply the temperature to a tin plate at 25 ° C with a medium wool roller (Otsuka Brush Manufacturing Co., Ltd.) so that the coating amount is 50 g (per 30 cm x 30 cm) until the bubbles generated from the start of painting disappear. The defoaming performance was judged according to the following criteria. The results are shown in Table 1.

◯: Bubbles disappeared in less than 15 seconds
Δ: Bubbles disappeared in 15 or more and less than 30 seconds
X: It took more than 30 seconds for the bubbles to disappear

Performance test 2 (finished appearance)
After diluting 1000 parts each of the non-aqueous coating compositions (1) to (3), (H1) and (blank) with mineral spirit and adjusting to 50 KU (25 ° C) with a stormer viscometer, 25 ° C. The temperature was adjusted to 0.076 mm, the coating was applied to a wet film thickness of 0.076 mm, and the number of craters in the coating film after drying at 25 ° C for 24 hours was counted. The finished appearance was judged according to the following criteria. The results are shown in Table 1.

○: 2 or less craters ×: 3 or more craters

Performance test 3 (stain resistance)
After diluting 1000 parts each of the non-aqueous coating compositions (1) to (3), (H1) and (blank) with mineral spirit and adjusting to 77 KU (25 ° C) with a Stormer viscometer, 25 ° C. And the curing agent {Barnock DN-990, DIC Corporation, Polyisocyanate, "Barnock" are registered trademarks of DIC Corporation. ) 81.7 parts are uniformly mixed, painted on a 10 x 30 cm stainless steel plate so that the wet film thickness is 0.1 mm, and the dried painted plate is 18 m above the ground in Tokai City, Aichi Prefecture (6 stories building). Painted surface on the outdoor raindrop test table (made of stainless steel, equipped with a roof (made of stainless steel, 80 cm in length, 110 cm in width, 5 mm in depth and 5 mm in depth with a rain groove (with an inclination of 30 degrees with respect to the horizontal plane))). Install it vertically and with the painted surface facing north, leave it for 30 days so that rainwater from the rain ditch on the roof flows along the painted surface, and evaluate the degree of dirt according to the following criteria. This is defined as stain resistance and is shown in Table 1.

○: Rainwater dripping is inconspicuous ×: Rainwater dripping marks are clear

As shown in Table 1, the defoaming agent of the present invention was superior in the finished appearance and stain resistance of the coating film as compared with the defoaming agent for comparison.

Claims (3)

It contains silicone (A1) having a weight average molecular weight of 200,000 to 2 million, silicone (A2) having a weight average molecular weight of 30,000 to 150,000, and a liquid polymer (B) .
A defoaming agent, wherein the liquid polymer (B) is a poly-α-olefin (b1), a polydiene (b2), or a mixture thereof . Based on the total weight of silicone (A1), silicone (A2) and liquid polymer (B), the content of silicone (A1) is 35 to 99% by weight, and the content of silicone (A2) is 0.1 to 20% by weight. %, The defoaming agent according to claim 1, wherein the content of the liquid polymer (B) is 0.9 to 45% by weight. A non-aqueous coating composition comprising the defoaming agent, filler and binder according to claim 1 or 2.