JP6298975B2 - Antifoam - Google Patents

Description

  The present invention relates to an antifoaming agent. More specifically, the present invention relates to an antifoaming 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 an antifoaming agent for non-aqueous coating compositions, the following general formula (1)

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

[Wherein, R3 is an alkyl group having 1 to 4 carbon atoms, and R4 is a hydrocarbon group having 12 to 24 carbon atoms. ] A non-foaming resin-dispersed paint antifoaming agent comprising a polymer having an average molecular weight of 10,000 to 200,000 obtained by polymerizing (copolymerizing) one or more of the acrylic acid alkyl ester monomers represented by Is known (Patent Document 1).

JP 2002-301306 A

Although conventional antifoaming agents have good antifoaming performance, there is a problem that craters are generated and the finished appearance of the coating film is poor.
An object of the present invention is to provide an antifoaming agent which is excellent in antifoaming performance and has a good finished appearance of a coating film.

The antifoaming agent for non-aqueous coating compositions of the present invention is characterized by containing a liquid polymer (A) and a fluorine-modified organopolysiloxane (B) containing an organosiloxane unit (b1) represented by the chemical formula (1) And
Liquid polymer (A) poly α-olefin (a1), polydienes (a2), poly (meth) acrylate (a3), the polyalkylene oxide compound (a4) or mixtures der Ru gist these points.

  The feature of the non-aqueous coating composition of the present invention is that it contains the antifoaming agent, filler and binder described above.

  The antifoaming agent of the present invention is excellent in antifoaming performance, and the finished appearance of the coating film is also good.

  The characteristics of the non-aqueous coating composition of the present invention include the above-mentioned antifoaming agent, so that it has excellent defoaming performance and does not cause abnormal appearance such as craters.

  “Liquid” means that the viscosity {the viscosity itself (neat viscosity)} measured with a Brookfield rotary viscometer according to JIS K7117-1: 1999 is 1,000 Pa · s (25 ° C.) or less. To do.

  The viscosity of the liquid polymer (A) (JIS K7117-1: 1999, 25 ° C., Pa · s, neat viscosity) is preferably 0.2 to 100, more preferably 0.3 to 30, particularly preferably 0. .5-3.

  The liquid polymer (A) is not particularly limited as long as it is liquid, but the polyalphaolefin (a1), polydiene (a2), poly (meth) acrylate (a3), polyalkylene oxide compound (a4), silicone (a5) And mixtures thereof.

  The poly α-olefin (a1) is not particularly limited as long as it is composed of 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 (a1), ethylene-α olefin copolymers and polypropylene are preferable from the viewpoint of defoaming performance and finished appearance of the coating film.

  Poly alpha olefins can be easily obtained from the market. For example, Lucant (registered trademark) series {HC-40 (830 mPa · s), HC-100 (2.6 Pa · s), HC-600 (manufactured by Mitsui Chemicals, Inc.) 27 Pa · s), HC-1100 (50 Pa · s), HC-2000 (95 Pa · s)} and the like. In addition, the numerical value in a parenthesis is the viscosity measured at 25 degreeC using the Brookfield type rotary viscometer based on JISK7117-1: 1999, respectively.

  The polydiene (a2) is not particularly 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 comonomer of the butadiene copolymer include acrylonitrile and styrene.

  The polydiene (a2) can be easily obtained from the market. Examples thereof include POLYVEST (registered trademark) 110 (polybutadiene, 650 mPa · s), POLYVEST 130 (polybutadiene, 2.4 Pa · s) manufactured by EVONIK. In addition, the numerical value in a parenthesis is the viscosity measured at 25 degreeC using the Brookfield type rotary viscometer based on JISK7117-1: 1999, respectively.

  The poly (meth) acrylate (a3) is not particularly limited as long as it is a liquid poly (meth) acrylate, and polyacrylates, polymethacrylates, acrylate / methacrylate copolymers, and the like can be used. Examples of (meth) acrylates include esters of alkyl having 1 to 30 carbon atoms and (meth) acrylic acid. Note that “•• (meth) acryl ••” means “•• cri ••” and “•• metacri ••”.

  The polyalkylene oxide compound (a4) is not particularly limited as long as it is a liquid polyalkylene oxide compound, and includes a reactant of an active hydrogen compound and an alkylene oxide (such as ethylene oxide, propylene oxide, and butylene oxide).

  The silicone (a5) is not particularly limited as long as it is a liquid silicone, and includes silicone having a dimethylsiloxane skeleton excluding the fluorine-modified organopolysiloxane (B).

  Of these liquid polymers (A), polyalphaolefin (a1), polydiene (a2) and silicone (c5) are preferred, and polyalphaolefin (a1), polydiene (a2) and mixtures thereof are more preferred.

  In the chemical formula (1), as the fluoroalkyl group (Rf), a fluoroalkyl group having 1 to 8 carbon atoms can be used, and 1,1,1-trifluoromethyl, 3,3,3-trifluoropropyl, 4 , 4,4,3,3-pentafluoro-1-butyl, 6,6,6,5,5,4,4,3,3-nonafluoro-1-hexyl and 8,8,8,7,7, 6,6,5,5,4,4,3,3-tridecafluoro-1-octyl and the like. Among these, 6,6,6,5,5,4,4,3,3-nonafluoro-1-hexyl is preferable from the viewpoint of defoaming performance.

  Examples of the alkyl group (R) having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, 2-ethylhexyl, n-decyl and n- And dodecyl. Of these, methyl is preferable from the viewpoint of antifoaming performance.

The fluorine-modified organopolysiloxane (B) may contain an organosiloxane unit (b2) other than the organosiloxane unit (b1).
Other organosiloxane units (b2) include dimethylsiloxane units, methylhydrogensiloxane units, methylphenylsiloxane units, and diphenylsiloxane units. Of these, dimethylsiloxane units are preferred from the viewpoint of antifoaming performance.

  When the fluorine-modified organopolysiloxane (B) is composed of an organosiloxane unit (b1) and another organosiloxane unit (b2), the content (mol%) of the organosiloxane unit (b1) represented by the chemical formula (1) ) Is preferably from 10 to 80, more preferably from 20 to 78, and particularly preferably from 30 to 75, based on the number of moles of all organosiloxane units constituting the fluorine-modified organopolysiloxane (B). In this case, the content (mol%) of the other organosiloxane unit (b2) is preferably 20 to 90, based on the number of moles of all organosiloxane units constituting the fluorine-modified organopolysiloxane (B). More preferably, it is 22-80, Most preferably, it is 25-70. Within these ranges, the defoaming performance and the finished appearance of the coating film are further improved.

  The fluorine-modified organopolysiloxane (B) can be produced by a known method (for example, JP-A-59-130894) or the like, and can be easily obtained from the market. As products available from the market, FL100, FA-600, FA-630, X-22-821, X-22-822 (Shin-Etsu Chemical Co., Ltd.); FS-1265 (Toray Dow Corning Co., Ltd.), etc. Can be mentioned.

  The content (% by weight) of the liquid polymer (A) is preferably 60 to 95, more preferably 65 to 90, based on the weight of the liquid polymer (A) and the fluorine-modified organopolysiloxane (B). Further, the content (% by weight) of the fluorine-modified organopolysiloxane (B) is preferably 5 to 40, more preferably 10 to 10, based on the weight of the liquid polymer (A) and the fluorine-modified organopolysiloxane (B). 35. Within these ranges, the defoaming performance and the finished appearance of the coating film are further improved.

  The antifoaming agent of the present invention may further contain a ketone (C) having 3 to 6 carbon atoms and a hydrocarbon (D) having 5 to 12 carbon atoms.

  Examples of the ketone (C) having 3 to 6 carbon atoms include dimethyl ketone (acetone), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone. Of these, methyl isobutyl ketone and cyclohexanone are preferred from the viewpoint of defoaming performance.

  Examples of the hydrocarbon having 5 to 12 carbon atoms (D) include linear saturated hydrocarbons (n-pentane, n-hexane, n-heptane, n-dodecane, etc.), branched saturated hydrocarbons (sec-pentane, tert-pentane). And isododecane), linear unsaturated hydrocarbons (such as 1-pentene, 1-hexene and 1-dodecene) and branched unsaturated hydrocarbons (isopentene, 3-methyl-1-butene, 2,2-dimethyl-1-propene and Isododecene, etc.). Among these, from the viewpoint of defoaming performance, linear saturated hydrocarbons are preferable, linear saturated hydrocarbons having 5 to 8 carbon atoms are more preferable, and n-hexane and n-heptane are particularly preferable.

  When the ketone (C) and the hydrocarbon (D) are contained, the total content (% by weight) of the ketone (C) and the hydrocarbon (D) is the same as that of the liquid polymer (A) and the fluorine-modified organopolysiloxane (B). Based on weight, 100-20000 are preferable, More preferably, it is 400-10000. Within this range, the defoaming performance and the finished appearance of the coating film are further improved.

  When the ketone (C) and the hydrocarbon (D) are contained, the content (% by weight) of the ketone (C) is preferably 60 to 95 based on the total weight of the ketone (C) and the hydrocarbon (D). More preferably, it is 70-90. Within this range, the defoaming performance and the finished appearance of the coating film are further improved.

  When the ketone (C) and the hydrocarbon (D) are contained, the content (% by weight) of the hydrocarbon (D) is 5 to 40 based on the total weight of the ketone (C) and the hydrocarbon (D). More preferably, it is 10-30. Within this range, the defoaming performance and the finished appearance of the coating film are further improved.

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

The hydrophobic silica is not limited in size, type and the like as long as it can be finely dispersed in the antifoaming 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 a powder (solid) by gas adsorption”, and the hydrophobic silica in a dry state is a one-point method by the gas adsorption method (carrier gas method). taking measurement. A nitrogen-helium mixed gas is used as the carrier gas. The specific surface area can be calculated from the value of the desorption peak.

  Hydrophobic silica can be easily obtained from the market. For example, as trade names, Nipsil SS-10, SS-40, SS-50 and SS-100 (Tosoh Silica Co., Ltd., “Nipsil” is Tosoh Silica Corporation AEROSIL R972, RX200 and RY200 (Nippon Aerosil Co., Ltd., “AEROSIL” is a registered trademark of Evonik Degussa BM Behrer.), TS-530, TS-610, TS-720 (Cabot Carbon) AEROSIL R202, R805 and R812 (Degussa Japan Co., Ltd.), REOLOSIL MT-10, DM-10 and DM-20S (Tokuyama Corporation, “REOLOSIL” is a registered trademark of the same company), and SYLOPHOBIC10 , 702,505 and 603 (Fuji Silysia Chemical Co., Ltd., "SYLOPHOBIC" is a registered trademark of the company.), And the like.

  When the 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 liquid polymer (A) and the fluorine-modified organopolysiloxane (B). Preferably it is 1-30. Within this range, the antifoaming property is further improved.

The antifoaming agent of the present invention is prepared by uniformly mixing a liquid polymer (A) and a fluorine-modified organopolysiloxane (B) and, if necessary, a ketone (C) and a hydrocarbon (D) and / or hydrophobic silica. it can.
When the ketone (C) and the hydrocarbon (D) are contained, it is preferable to uniformly mix at a temperature as low as possible (preferably 10 to 50 ° C, more preferably 20 to 40 ° C) in consideration of their volatility. .

  The antifoaming agent of the present invention is effective for both the aqueous foaming liquid and the nonaqueous foaming liquid, but is more effective for the nonaqueous foaming liquid, and particularly effective for the nonaqueous coating composition. Among non-aqueous coating compositions, it is also effective for non-aqueous paints used for coating industrial products and buildings, floor coating materials, and roofing waterproof paints. The aqueous foaming liquid means a foaming liquid containing water, and the nonaqueous foaming liquid (nonaqueous coating composition or the like) means a foaming liquid (coating composition or the like) that does not contain water.

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

  As fillers, 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 antifoaming agent in the non-aqueous coating composition is preferably 0.1 to 1, more preferably 0.3 to 0 based on the weight of the antifoaming agent, filler and binder. .5.

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

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

  The non-aqueous coating composition of the present invention can contain an additive that can be blended with a general non-aqueous coating composition within a range that does not affect the effects of the present invention. Examples of such additives include curing agents, thickeners, plasticizers, antiseptics, antifungal agents, algaeproofing agents, leveling agents, pigment dispersants, anti-skinning agents, dryers, matting agents, and UV absorbers. , Light stabilizers, antioxidants, low pollution agents and catalysts.

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

Hereinafter, unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.
The molar ratio of methyl hydrogen polysiloxane was determined by ¹ H-NMR. The degree of polymerization was calculated from the number average molecular weight and the molar ratio.

The number average molecular weight was measured with the following apparatus and conditions.
Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Tosoh Corporation guard column HXL-H
+ Tosoh Co., Ltd. TSKgel SuperHZ4000
+ TSKgel SuperHZ3000 manufactured by Tosoh Corporation
+ TSKgel SuperHZ2000 made by Tosoh Corporation
+ TSKgel SuperHZ2000 made by Tosoh Corporation
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran flow rate 1.0 ml / min standard; polystyrene sample: calculated from number average molecular weight using 1% tetrafuran solution

<Synthesis Example 1> Synthesis of fluorine-modified organopolysiloxane (B1) Octamethylcyclotetrasiloxane (Momentive Performance Materials) was added to a four-necked flask equipped with a stirrer, thermometer, dry nitrogen inlet and calcium chloride tube. -Japan Godo Kaisha TSF404) 642 parts (2.2 mol parts), tetramethyltetrahydrogencyclotetrasiloxane (manufactured by Wako Pure Chemical Industries, Ltd.) 58 parts (0.24 mol parts), hexamethyldisiloxane (Tokyo) 15 parts (0.09 mole part) manufactured by Kasei Kogyo Co., Ltd. and 5 parts (0.03 mole part) trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) are added, and room temperature (25-30 ° C: The same as above) for 24 hours (ring-opening polymerization), and then 28% aqueous ammonia solution (Tokyo Chemical Industry Co., Ltd.). And the precipitated salt was separated by filtration to obtain methyl hydrogen polysiloxane (average polymerization degree 104, dimethylsiloxane: methylhydrogensiloxane = 9: 1 (molar ratio)).

In a flask equipped with a thermometer, a stirrer, and a dropping funnel, 70 parts of the above-mentioned methyl hydrogen polysiloxane and 0.1 part of chloroplatinic acid (manufactured by Wako Pure Chemical Industries, Ltd.) are placed and heated to 110 ° C. 6,6,6,5,5,4,4,3,3-nonafluoro-1-hexene {CF ₃ (CF ₂ ) ₃ CH═CH ₂ } (manufactured by Alpha Acer) 23.8 parts (0 0.1 mol part) was added dropwise over 2 hours, and the mixture was further heated and stirred at 110 ° C. for 2 hours to obtain a reaction mixture.

  The reaction mixture was cooled to 60 ° C, 10 parts of a 0.1% aqueous sodium hydroxide solution was added, and the mixture was stirred at 60 ° C for 1 hour, and then under reduced pressure, water and unreacted 6,6,6,5,5,4 , 4,3,3-Nonafluoro-1-hexene was distilled off to obtain a concentrate. After adding 1 part of activated carbon to the concentrate and stirring with heating at 60 ° C. for 1 hour, the activated carbon was separated by filtration to obtain a fluorine-modified organopolysiloxane (B1) represented by the following formula. The resulting fluorine-modified organopolysiloxane (B1) was a colorless and transparent liquid.

<Synthesis Example 2> Synthesis of fluorine-modified organopolysiloxane (B2) The amount of octamethylcyclotetrasiloxane used is changed from 642 parts (2.2 mole parts) to 163 parts (0.55 mole parts), and tetramethyltetrahydrogen. The amount of cyclotetrasiloxane used is changed from 58 parts (0.24 mole parts) to 530 parts (2.2 mole parts) to 6,6,6,5,5,4,4,3,3-nonafluoro-1- Fluorine modification represented by the following formula in the same manner as in Synthesis Example 1 except that the amount of hexene used was changed from 23.8 parts (0.1 mole part) to 217 parts (0.88 mole part). Organopolysiloxane (B2) was obtained (average degree of polymerization 119, dimethylsiloxane: fluorine-modified siloxane = 2: 8 (molar ratio)). The resulting fluorine-modified organopolysiloxane (B2) was a colorless and transparent liquid.

<Synthesis Example 3> Synthesis of Comparative Polymer Solution 80 parts of toluene while blowing nitrogen gas into a four-necked flask equipped with an eggplant flask with a vacuum distillation condenser, a thermometer, a stirrer, a dropping funnel and a nitrogen gas blowing port Charge 0.2 part of stannous chloride (SnCl ₂ ). While stirring this, the temperature was adjusted to 30 ° C., and 100 parts of methacrylic acid octadecyl ester was added dropwise from the dropping funnel over 3 hours. 30 minutes after completion of dropping, 3 parts of n-butanol was added to stop the reaction, and a polymer solution of octadecyl methacrylate was obtained. Thereafter, the polymer concentration was adjusted to 50% with toluene to obtain a toluene solution of polymer (HA).
The number average molecular weight of the polymer (HA) was 50,000.

Example 1
90 parts of liquid polymer (A1, polybutadiene, POLYVEST110, 650 mPa · s (25 ° C.) manufactured by EVOINK) and 10 parts of fluorine-modified organopolysiloxane (B1) were uniformly mixed to obtain the antifoaming agent (1) of the present invention. It was.

(Example 2)
95 parts of liquid polymer (A2, ethylene / propylene copolymer, Lucant HC-40, 830 mPa · s (25 ° C.)), 5 parts of fluorine-modified organopolysiloxane (B2), 60 parts of ketone (C1, methyl isobutyl ketone) and 40 parts of hydrocarbons (D1, n-hexane) were uniformly mixed to obtain an antifoaming agent (2) of the present invention.

(Example 3)
60 parts of liquid polymer (A3, ethylene / propylene copolymer, Lucant HC-100, 2.6 Pa · s (25 ° C.)), 40 parts of fluorine-modified organopolysiloxane (B1), 1900 parts of ketone (C2, cyclohexanone) and 100 parts of hydrocarbon (D1) was uniformly mixed to obtain an antifoaming agent (3) of the present invention.

Example 4
85 parts of the liquid polymer (A2), 15 parts of the fluorine-modified organopolysiloxane (B2), 9000 parts of the ketone (C1) and 1000 parts of the hydrocarbon (D1) are uniformly mixed to obtain the antifoaming agent (4) of the present invention. It was.

(Example 5)
40 parts of liquid polymer (A1), 40 parts of liquid polymer (A3), 20 parts of fluorine-modified organopolysiloxane (B1), 16000 parts of ketone (C2) and 4000 parts of hydrocarbon (D1) are uniformly mixed, An antifoaming agent (3) was obtained.

(Comparative Example 1)
100 parts of fluorine-modified organopolysiloxane (B1), 1900 parts of ketone (C1) and 100 parts of hydrocarbon (D1) were uniformly mixed to obtain a defoaming agent (H1) for comparison.

(Comparative Example 2)
The toluene solution of the polymer (HA) prepared in Synthesis Example 3 was used as a comparative antifoaming agent (H2).

(Comparative Example 3)
50 parts of a fluorine-modified organopolysiloxane (B1), 100 parts of a toluene solution of the polymer (HA) prepared in Synthesis Example 3, 1850 parts of a ketone (C1) and 100 parts of a hydrocarbon (D1) are uniformly mixed for comparison. An antifoaming agent (H3) was obtained.

  Using the antifoaming agents (1) to (5) of the present invention and the antifoaming agents (H1) to (H3) for comparison as the evaluation sample, they are uniformly mixed with the following composition, and the nonaqueous system for evaluation is used. Coating compositions (1) to (4) and (H1) to (H3) were prepared. {Each number corresponds to the number of antifoaming agent obtained in Examples and Comparative Examples. }. A blank non-aqueous coating composition was prepared in the same manner except that the evaluation sample was not used.

[Non-aqueous coating composition for evaluation]
ACRIDIC A-837 (* 1) 147 parts TYPAKE R-930 (* 2) 228 parts Mineral Spirit 80 parts EFKA RM 1920 (* 3) 2 parts ACRIDIC A-848 (* 1) 508 parts Mineral Spirit 30 parts Evaluation sample (Defoamer) 5 parts

* 1 “Aclidick”, a polyol resin manufactured by DIC Corporation, is a registered trademark of DIC Corporation.
* 2 Titanium dioxide manufactured by Ishihara Sangyo Co., Ltd., “Taipeke” is a registered trademark of Ishihara Sangyo Co., Ltd.
* 3 “EFKA”, a thickener made by BASF SE, is a registered trademark of Ciba Incorporated.

Performance test 1000 parts of each of non-aqueous coating compositions (1) to (4), (H1) to (H3) and (blank) are diluted with mineral spirits so that they become 77 KU (25 ° C.) with a Stormer viscometer. After adjustment, the temperature is adjusted to each coating temperature, and the curing agent {Bernock DN-990, DIC Corporation, polyisocyanate, "Bernock" are registered trademarks of DIC Corporation. ) 81.7 parts of the mixture were uniformly mixed and applied to a tin plate at 25 ° C. with a medium wool wool roller manufactured by Otsuka Brush Manufacturing Co., Ltd. to a coating amount of 50 g (per 30 cm × 30 cm). Table 1 shows the defoaming performance based on the disappearance time, and the finished appearance was evaluated by the number of craters of the coating film after drying at 25 ° C. for 24 hours.

The defoaming performance was judged by the disappearance time of the foam after coating, and the following criteria were used.
○: Bubble disappeared in less than 15 seconds Δ: Bubble disappeared in 15 to less than 30 seconds ×: It took 30 seconds or more to disappear

The finished appearance was judged by the number of craters, and the following criteria were used.
○: 2 or less craters (per 30 cm x 30 cm)
Δ: 3-5 craters (per 30 cm x 30 cm)
X: 6 or more craters (per 30 cm x 30 cm)

  As shown in Table 1, the antifoaming agent of the present invention was superior in antifoaming performance and excellent in finished appearance of the coating film as compared with a comparative antifoaming agent.

Claims (6)

Containing a liquid polymer (A) and a fluorine-modified organopolysiloxane (B) containing an organosiloxane unit (b1) represented by the chemical formula (1) ,
Liquid polymer (A) poly α-olefin (a1), polydienes (a2), poly (meth) acrylate (a3), polyalkylene oxide compound (a4) or a non-aqueous coating composition, characterized in mixtures der Rukoto thereof Antifoaming agent for objects .

However, Rf is a fluoroalkyl group and R is a C1-C12 alkyl group. Based on the weight of the liquid polymer (A) and the fluorine-modified organopolysiloxane (B), the content of the liquid polymer (A) is 60 to 95% by weight, and the content of the fluorine-modified organopolysiloxane (B) is 5 to 40. The antifoaming agent according to claim 1, wherein the defoaming agent is in wt%. The content of the organosiloxane unit (b1) represented by the chemical formula (1) is 10 to 80 mol% based on the number of moles of all organosiloxane units constituting the fluorine-modified organopolysiloxane (B). Or the antifoamer of 2. Furthermore, it contains a C3-C6 ketone (C) and a C5-C12 hydrocarbon (D), a C3-C6 ketone (C) and a C5-C12 hydrocarbon (D). The antifoaming agent according to any one of claims 1 to 3, wherein the total content of is 100 to 20000% by weight based on the weight of the liquid polymer (A) and the fluorine-modified organopolysiloxane (B). Based on the total weight of the C3-C6 ketone (C) and the C5-C12 hydrocarbon (D), the C3-C6 ketone (C) content is 60-95 wt%, carbon The antifoaming agent according to claim 4, wherein the content of the hydrocarbon (D) of 5 to 12 is 5 to 40% by weight. A non-aqueous coating composition comprising the antifoaming agent, filler and binder according to any one of claims 1 to 5.